Soviet copy machine. A story about bugs in copiers. Motors and fusing electronics

With the advent of the new year, social network users unearthed an old filmstrip (a kind of slide show with captions) “In 2017” in their caches. Its authors in an intelligible form tried to tell the Soviet kids what the world will be like 57 years later on the anniversary of the Great October Revolution: robots, video communications, space travel, nuclear trains.

Stills from the 1957 animated film:

But only in 1953 V.M. Friedkin, who had just graduated from Moscow University, created the first Soviet copier, and subsequently developed the theory of xerography. The future, as we know, has come much earlier than 2017, with regards to scanners - for sure.

In the Soviet Union copiers and duplicating machines (hectographs) were considered strategic, they were registered with the KGB without fail, and a strict record was kept of who copied what and where.
"Erika" takes four copies,- was sung in the famous song of Alexander Galich (a hint, as you understand, of samizdat ...)

For the unauthorized use of copying and scanning technologies in the USSR, one could "sit down" for 10 years.

The beginning of the distribution of computer technology in the USSR opened up a new field for innovative developments. In the late 80s, a group of young engineers initiated the creation of a projection scanner.

Reference: The Russian Academy of Sciences was founded by the Decree of the ruling Senate of January 28 (February 8), 1724. It was recreated by the Decree of the President of the Russian Federation of November 21, 1991 as the highest scientific institution in Russia. Historical milestones.

Having achieved some success, colleagues organized a cooperative and started creating and promoting their development. The result of their work was the Uniscan projection scanner, which combined the capabilities of a scanner and a modern digital camera. It had a resolution of 72 megapixels. This resolution made it possible to see individual eyelashes in an A0 image of a person.

Scanner on a tripod

An image of 72 megapixels in the late 80s was obtained

The first samples of the scanner made it possible to obtain black-and-white images or images in grayscale. "Discover the world in all its amazing dullness!" - joked in advertising brochures. These models also did not differ in refined design. Later, light filters were added to the design, and from that moment on, the scanner made it possible to obtain full-color images.

The Uniscan scanner was used for obtaining and processing images in printing, for text recognition and creating databases, in cartography and design, for creating digital copies of rare books in public libraries, for macro and micro photography of stationary objects. The combination of a scanner with a microscope proved to be very popular in forensic science - the Uniscan scanner turned out to be the best that was offered in the world for these tasks.

Microscope with scanner Uniscan

As far as I understand this issue, this initiative group of young engineers in 1995 (already in the Russian Federation) founded Uniscan LLC, Novosibirsk.

Scanners for entering slides made it possible to enter information from transparent media with high quality. Usually these are either flatbed scanners with a special slide module, or drum scanners. Their main application is publishing and cartography. By the way, until recently, a teletype, using the principle of a drum scanner, was used to transmit page layouts of central publications throughout the territory of the former USSR.

Of course, we were not the first in this area:

The first SEAC* drum scanner, Russell Kirsch and background scanner control panel. 1957, USA.

But not outsiders either.

Soon, "manual" scanners appeared in the USSR:

Of the domestic encoding devices with freely movable sights, PKGIO is known - “Semiautomatic Encoding Graphic Information Optical” (the optical part is, apparently, a sight in the form of a magnifying glass with a crosshair and a built-in induction coil). The kit also includes an electric pencil and keyboards: a double (Russian and Latin, as well as an additional one with Greek letters) push-button keyboard and a keyboard in the form of a table with holes that you need to poke with an electric pencil - it is mounted in a tablet next to its working field. The resolution of the device reaches 0.1 mm.

I would like to note a special category of scanning (or rather copier) equipment - espionage (or reconnaissance).

Note: Espionage is an illegal intelligence activity of bodies (their agents) of foreign states, which, as a rule, involves the theft of officially classified information (state secrets) by the special services of other states.

The most famous (or rather "famous") special means are photocopiers "Cinnamon", "Winter" and "Sunburn".

Photocopier "Cinnamon" (from the archives of the Keith Melton Spy Museum)

The effectiveness of the use of rolling machines, as well as the need for fast and high-quality copying of a large number of documents, prompted the developers of NIL-11 (a specialized laboratory that was part of the Operational and Technical Directorate (OTU)) to create a portable photocopier rolling for A4 documents. In the new camera called “Cinnamon”, the document was covered with a pressure glass on the working side of the device (with dimensions similar to the A4 format), and the mirror-prism mechanism moving inside the device scanned the document evenly under the action of a spring.

For uniform illumination of the document in Cinnamon, a special thin and long illuminator, similar to fluorescent lamps, was provided, which moved along with the mirror-prism mechanism. Its movement, as well as the transportation of film, was provided by a spring cocked by a side lever to shoot one frame. The "Cinnamon" cassette held up to 400 frames of standard 35 mm film and could be quickly replaced with "fresh" film in a few seconds, which made it possible to copy a large number of documents. The lens aperture was selected depending on the film sensitivity. "Cinnamon" had a frame counter, as well as a convenient shutter release lever, which worked both from the right and from the left hand. To power the Cinnamon illuminator, a standard 110/220 volt power supply could be used, as well as a voltage of 12 volts through the car's cigarette lighter socket.

Set of apparatus "Cinnamon" (from the archive of the Keith Melton Spy Museum)

"Cinnamon" turned out to be a very effective device for quickly copying a large number of documents, for example, when the curator officer received secret documents from his agent through a cache for a fairly short time, copied them in a car, observing the requirements of secrecy, and after completing the work, returned them back to the agent in a predetermined way. "Cinnamon" was also actively used in safe houses and in hotel rooms, where documents received on time were delivered and, after photocopying, returned to official storage places. The dimensions and weight of Cinnamon, together with the power supply unit and cassettes preloaded with film, made it possible to carry the entire set in a regular briefcase or in an attache case, which ensured the secrecy of the entire operation of the device, both in a car in a parking lot or on the move, and for shooting documents in room.

The operational units of the KGB actively used the Cinnamon, noting the simple setup and convenient control of the device, in connection with which the serial production of the Cinnamon was organized at the Krasnogorsk plant, where the device was assigned the factory index C-125.

Later, the operational units of the KGB received the Cinnamon prototype, designed to use 16 mm film with an electric motor to drive the mirror-prism system and the film transport mechanism. The new "Zima" device was smaller in size and provided two copies of an A4 document with overlapping of each half of the sheet. The "Zima" cassette was designed for 400 frames, contained 6 meters of 16 mm film with double perforation and sensitivity from 45 to 700 units. GOST. Photographing of one frame began after shifting the lever-switch to the right with the thumb of the right hand, and was carried out for 2.5 seconds. The power supply units included in the Zima kit ensured the operation of the device from a 12-volt car network and from a standard 110/220-volt electrical network.

Despite the smaller dimensions and the presence of an electric drive, the Zima apparatus has not received active use in operational practice. According to KGB officers, the device often lay for years in the places of storage of operational equipment and was taken out only for the annual inventory. According to experts, copying an A4 document twice turned out to be inconvenient, and many operatives preferred the old Cinnamon.

Photocopier "Winter" (from the archive of the Keith Melton Spy Museum)

In the mid 1980s. a prototype of "Cinnamon" and "Winter" appears, the "Zagar" camera, for copying a full sheet of A4 onto 16 mm film with an electric drive of mirror-prism mechanisms for scanning and transporting the film.

The cassette "Zagar" was designed for 400 frames, the kit also included two more cassettes. Thus, "Zagar" could provide relatively fast copying of more than a thousand sheets of documents.

Photocopier "Zagar" (Courtesy of the Keith Melton Spy Museum)

However, the new "Zagar" did not receive active use, perhaps due to the relatively large weight (more than 3 kg) and increased dimensions, which, most likely, turned out to be inconvenient for operational officers in the case of transporting the "Zagar", which already hardly fit into standard portfolio. In the second half of the 1980s. active use of computer scanners began, on which copying was much easier compared to the bulky "Sunburn". All this led to the fact that the factory batch of "Zagarov" did not find application. New sets of this apparatus were stored for a long time in the warehouses of operational equipment, until an order was received to send the entire batch to NIL-11 for the destruction or possible use of individual blocks, assemblies and parts.

Thus ended the century of the very effective use by the KGB units of rolling cameras, which produced a mass of necessary and especially important documents for the USSR, including copies of materials in rare languages, when high-definition demands were made on the resulting negatives. Today, the arsenal of modern intelligence includes a variety of household digital devices that allow, without any camouflage, to scan documents and drawings of any complexity quite openly and easily.

By the way, the cameras of the Luna-9, Luna-13 spacecraft, the side cameras of the Lunokhods, and the Venus cameras can be attributed to scanners. And Luna-19 and -22 can be considered a real scanner. The camera was a linear photosensitive element that scanned the image of the Moon's surface moving under the apparatus. Snapshot:

Today, without scanners, we can no longer imagine our normal life:

Computer processing of photographs in the USSR (1987)

That's all that I managed to dig up about scanners in the USSR.
Maybe someone knows more?

Thanks for the important clarifications. [email protected],@hoegni, @petuhov_k and @Rumlin

Example g of the main engine of the copier.

Professional repair assumes that the specialist knows the principles of construction and operation of the repair facility.
The main engine in this copier is made as part of a drive module with an appropriate gearbox. The module is fixed on the body of the copier in a specially designated place with several screws. The toothed rotor of the engine rotates (through the corresponding gear ratios of the gearbox) two gears, one of them drives the drum unit cartridge, the second drives the toner fixing shafts and the paper feed rollers. The control and power signals of the module come to the motor control board from the side of the main control board of the copier, to the connector designated as CN1.
The motor used in this copier is a type of brushless DC motors (or, in other words, spindle motors), which is controlled by a special chip (motor driver).
Structurally, the motor consists of a stator with a certain number of windings and a rotor with a permanent multi-pole ring magnet. In our case, in order to reduce the step and reduce the torque ripple, the number of windings is increased to 9, i.e. one phase has three windings (see fig. 1).

Rice. 1. The structure of the main engine of the copier.

The motor rotor is located outside and has a permanent annular multipole magnet, and the stator has windings that are fixed on the board (this motor design is called "inverted"). To cause the rotor to rotate, it is necessary to pass current through the stator windings in a certain sequence. The power supply of the stator windings is carried out in such a way that between the magnetizing force (created by the stator) and the magnetic flux, a shift was maintained by a certain angle, i.e. a rotating magnetic field is created that acts on the permanent magnets of the rotor. As a result, the rotor, consisting of an annular multi-pole permanent magnet, begins to move after the magnetic field of the stator and rotate. The rotation of the rotor can only continue as a result of switching the stator windings. Moreover, when switching, two conditions must be met, according to which the stator windings must switch at a certain moment and with a given sequence. In this case, the position of the rotor is determined using position sensors, which are three Hall sensors. At the output of each of these sensors, differential signals are generated that indicate the strength and direction of the magnetic flux at the location where the sensor is installed. When the rotor rotates, the signals from the Hall sensors are sinusoidal voltages. Based on the analysis of signals from the Hall sensors, the microcircuit - the motor driver connects one or another phase of the stator.
The strength of the magnetic field determines the power and speed of the motor. By changing the current strength through the windings, you can achieve a change in the speed and torque of the engine. The most typical way to adjust the current intensity is to control the average value of the current through the windings, which is performed by pulse modulation of the supply voltage of the windings by setting the duration of the supply and removal of the supply voltage. Thus, to achieve the required average voltage value and, as a result, the average current. The speed, as a rule, is set in two ways: by a reference pulse signal or by adjusting the current flowing through the motor windings. Schematic diagram of the motor board is shown in fig. 2.

Rice. 2. Schematic diagram of the control board of the main motor of the copier.

From the side of the main control board, control signals are supplied to the Motor Module, which can be seen at the CN1 connector. These signals are used to control the engine. Connector pin numbers, their designation, and functionality are shown in Table 1.

Table 1. Purpose of CN1 connector signals

The motor rotation speed is determined by an inductive-type speed sensor, the windings of which are made in the form of a printed circuit board (meander paths of the conductor are etched under the rotor magnet on the printed circuit board, forming an inductor in which EMF is induced during rotation of the permanent ring magnet of the rotor).
The motor phases in the diagram are marked W1, W2, W3, each phase corresponds to two windings on the motor stator. The position of the rotor is monitored by three Hall sensors, which are indicated on the circuit diagram as HI, H2, NC. The windings are controlled by an output stage implemented as part of a control microcircuit. The formation of control signals for the motor, as well as the control of the current in the windings and their control is carried out (as we have already noted) through a specialized microcircuit (driver) LB1920. The LB1920 chip (see Fig. 2) is designed to control a 3-phase brushless motor. Its features include the following:
- wide operating voltage range: 9 - 30 V;
- the ability to work with currents up to 3.1A;
- built-in overcurrent protection;
- the presence of a built-in circuit for monitoring Hall sensors;
- the presence of digital speed control;
- presence of an output of external blocking (S/S);
- the presence of built-in protection against overheating of the chip crystal.
The internal structure of the LB1920 chip and the distribution of signals over the contacts of the chip are shown in fig. 3. The purpose of the contacts of the microcircuit, input and output signals are described in Table 2.

Rice. 3. Internal block diagram of LB1920 main motor driver

Table 2. Purpose of the signals of the control chip LB1920

Given the tendency of manufacturers to use spindle motors in many units of devices (for paper feeding, in drives for toner fixing units, in laser-scanner units, etc.), we hope that this material will be useful to repair and maintenance personnel.

we could have a domestic "copier". Attempts to create a similar technique were carried out as early as the mid-1950s, simultaneously with the development of Xerox itself. But the state then saw a threat to itself in the uncontrolled dissemination of data, so it deliberately hampered innovation.

"Xerox" Friedkin

It was believed that in the Soviet Union, under a planned economy, the issue of prompt copying of documents was not as acute as in countries with a free market. In numerous Soviet institutions, this problem was initially solved by photographic method and microfilm. Technical and design documentation had to be manually transferred to tracing paper, reproduced using blueprinting. All this was long, difficult and inconvenient.
Perhaps the most curious story is connected with the scientist Vladimir Fridkin, whose invention anticipated the development of the industry by a whole decade.
Fridkin graduated in 1952 with honors from the Physics Department of Moscow State University. But for a long time he could not start working in his specialty because of problems “on the fifth point”. The anti-Semitic campaign carried out at that time nullified the advantages of a red diploma.
Only a few months later, Vladimir Fridkin managed to get a job at the Research Institute of Printing Engineering, although initially he wanted to become a nuclear physicist.

At the Research Institute, Fridkin was provided with a completely empty office for work - there were only a table and a chair. It was not easy to do something productive in such conditions.

Friedkin spent a lot of time in the reading room of the Lenin Library, where a large collection of documents, scientific papers and books from all over the world was kept. Once he read an article by the American physicist Chester Carlson, which was devoted to photocopying. There was nothing like this in the Soviet Union then. Friedkin was inspired by the idea to create a copy machine.

He turned to the electrical engineering department of his research institute and asked for a high-voltage current generator. At his native physics department of Moscow State University, he got sulfur crystals and the necessary photographic enlarger. The inventor conducted all experiments in his small office. He managed to assemble a device called "Electroscopic Copier #1". The number "1" in the title implied that others would follow the first model.

Vladimir Fridkin:

I didn't waste time. I went to Leninka, read magazines on physics, bought some equipment. I came up with the idea to implement a new photographic process in which the photoelectret served as a photosensitive layer, and the development was carried out using the triboelectric effect. The process was also conceived as a method for creating optical memory. The photoelectret not only formed, but also memorized the image. The latent image could be stored for quite a long time, and it could be developed long after the exposure. The layout was done quickly. I used polycrystalline sulfur and later other photoconductors like zinc and cadmium sulfide. The development was carried out with asphalt powder.

At first, Friedkin tried to copy a page from a book, orders for the institute, then moved on to photographs. Once he made a copy of a picture of a Moscow street and showed it to the director of his research institute. He enthusiastically exclaimed: “Do you even understand what you invented ?!”.

The engineers of the institute were immediately ordered to bring the existing developments to mind and assemble a sample machine that could make photocopies. Thus, Friedkin created the first copy machine in the USSR. It was autumn 1953.

Vladimir Fridkin:
Many years later, I learned that in the United States, at the Haloid company, later renamed Xerox, the first models began to appear at the same time. But their work was based on a different principle.

The first Soviet copier was a box about one meter high and half a meter wide. A current generator and two cylinders were fixed on it. The device turned out to be surprisingly simple and understandable. The minister personally came to see the invention. He was so impressed by what he saw that he ordered to organize the mass production of new devices at a factory in Chisinau. And in Vilnius, a special research institute was opened, which was engaged in research on electrography.
Vladimir Fridkin, then only 22 years old, became deputy director of the institute. He received a good cash prize. They even shot a TV movie about the inventor, dedicated to the achievements of Soviet science.

In 1955, the creator of the Soviet copier went to work at the Institute of Crystallography. He took his invention with him. Almost every day colleagues came to his office to copy some scientific article from a foreign journal. But in 1957 it all ended. “Somehow the head of the special department came to me - there were such departments in every institute - and said that the photocopier should be written off,” Fridkin said. The KGB believed that the machine could be used to distribute materials banned in the USSR.

The authorities then did not encourage the development of communication. For example, each radio receiver was registered without fail. The state security authorities demanded that prints from all typewriters be kept if it was necessary to identify the author of the printout. There was a struggle with "samizdat". The manuscripts of banned authors were multiplied at night on typewriters. And then a whole copier was found without supervision.

Soon the production of new devices was also closed. The first of the assembled models was disassembled into parts. According to legend, its most valuable part - a semiconductor plate - was preserved and hung in the women's toilet of the institute like a mirror.

Years later, the Soviet Union began to buy copiers abroad. It was a Xerox machine. One of these apparatuses was also brought to the Institute of Crystallography, where Fridkin continued to work. But it was already possible to use the technique only under the supervision of a special person who monitored what was copied and by whom.

"REM" and "Era"

In the late 1960s, the USSR returned to the idea of creating their own copiers. At the Kazan Optical and Mechanical Plant, they began to assemble the REM device - a rotary electrographic machine. It was produced in two versions - REM-420 and REM-620. The numbers indicated the width of the roll paper. The power of the electrical equipment of the first devices was very large. For example, REM-620 consumed almost 8 kW of electricity. They weighed about a ton and worked on them for two people.

A little later, other factories began to make similar devices - BelOMO and the Grozny Plant of Printing Machines under the Era brand. It is noteworthy that in Grozny they made small-format devices for A3 and A4, which worked not only with roll paper, but also with individual sheets.

"REM" and "Era", unlike the Friedkin apparatus, largely repeated the "copiers" of the 1950s and 60s in terms of the principle of operation and optical design. But when Western models became more and more reliable, ergonomic and compact, the main advantage of the Soviet ones was the low cost of consumables.
The first Soviet-made copiers were also quite flammable. When the paper stopped moving, it almost immediately ignited under the action of a heat flux from an infrared emitter. In the premises where the equipment stood, it was necessary to install a special fire extinguishing system, and a carbon dioxide fire extinguisher was attached to the body of the apparatus.

Among those who worked with the devices "Eoa" and "REM", there was such a saying - "The operator who did not burn and did not extinguish the device, like a tankman who was not in battle." When hiring, personnel officers seriously asked: “How many times did they burn?”.

Similar equipment was produced until the end of the 1980s. This is where the story of the Soviet "copiers" ended.

Vladimir Fridkin:
In 1965 Chester Carlson visited our laboratory at the Institute of Crystallography. The founder of xerography became interested in my articles. We were photographed together with an electret electric camera. In the late 1950s, Columbia University professor Hartmut Kalman and co-workers repeated my experiments on electrophotography on photoelectrets and found an interesting application for it in space communications. He spoke about this at a colloquium in Munich, where we met in 1981. For these works, the American Photographic Society awarded me the Kozar Medal, and the German and Japanese Society elected me an honorary member.

In addition, in 2002, the International Committee for Imaging Science awarded Vladimira Fridkin the Berg Prize for his "outstanding contribution to the development of unusual (silver-free) photographic processes and international cooperation in this field."

Now the inventor is 83 years old.

The location of the resistors on the boards of these devices is shown in Figure 2.53

On the control panel board of devices that are not equipped with an automatic exposure sensor, the trimming resistor is located differently (Fig. 2.54)

The figures show that only one of the trimmers on the control board is common to the entire series - in the schematic diagrams it is designated as VR604 and serves to change the intensity of the scanning lamp glow. It must be adjusted first, after turning off the automatic exposure control mode, if such is provided in the device.

This adjustment is performed by lightly turning the rotating trimmer disk with a thin screwdriver or simply with your finger, since the design of the disk allows this. After each change in the position of the disk, you should run the copy and determine from it in which direction and by how much it should now be rotated.

If the copy comes out too dark, with the so-called veil on the background, then VR604 should be turned to the right, clockwise.

If the copy is too faded, thin lines on it are lost and the overall contrast is insufficient - VR605 is turned to the left, counterclockwise.

For precision alignment of the exposure, a special test sheet for copiers is used, on which there is a scale of exact gray gradations (for a more detailed description, see section 1.4).

When using the VR604 setting it is possible to force the machine to produce copies of the best quality in manual mode, you should proceed to adjusting the automatic exposure, and if it is not provided for by the design, then complete the procedure by returning the removed control panel cover to its place.

To coarsely adjust the AE sensor, you can proceed in the same way as when adjusting the VR604, that is, turn the VR602 and VR603 dials until the optimal copy quality is achieved with the AE mode activated from the control panel. With some skill, it's quite possible to set the auto exposure well even without a test sheet and a multimeter.

A more scientific way to set up automatic exposure consists of the following steps:

1. Turn off the power of the copier.

2. Remove the control panel cover.

3. Turn the trimmer resistors VR602 and VR603 clockwise as far as they will go.

4. Place an original on the exposure glass that is evenly filled with text with thin lettering and does not contain large voids or areas of black color, such as illustrations included in the text. Newspaper is the best for this purpose. The original must cover the automatic exposure sensor window located in the central part of the copier (Fig. 2.55).

5. Short-circuit three jumpers JP607, JP605 and JP604 on the control board at the same time using a slotted screwdriver, as shown in fig. 2.56.

6. Keeping the jumpers connected, turn on the machine's power. The machine's motor starts rotating, 0 appears on the copy quantity indicator, and the scan lamp lights up. At this point, release the jumpers.

7. Take a digital multimeter, set it to the range of 20 V DC and measure the voltage between the anode of the diode D606 and the jumper JP607 (Fig. 2.57)

8 Rotate the trimmer resistor VR602 until the voltage on the Multimeter indicator is 4 V with a maximum error of 0.1 V

9 Replace the newspaper on the exposure glass with a small stack of blank paper sheets and repeat the voltage measurement between the anode of diode D606 and jumper JP607. Now rotate VR603 until the Multimeter reads about 1.8V with the same 0.1V tolerance.

Note. Since in each specific case it is necessary to take into account the differences in the state of the working units of the apparatus, which can to some extent affect the level of automatic exposure, sometimes it is necessary to somewhat correct the exposure set by the Multimeter. If the quality of copies in automatic mode after adjustment is perfect, you should immediately go to the last, thirteenth, step of the procedure.

10. Reset the adjustment mode by turning the machine off and on again.

11. Place a newspaper, test sheet or any other original on the exposure glass and check how perfectly the automatic exposure is set

12. If the copy is too light despite the adjustment, move VR602 slightly counterclockwise. If, on the contrary, the copy is too dark, move the VR602 slightly clockwise. Repeat these steps until the optimum copy quality is achieved with automatic metering turned on. To completely eliminate the risk that an incorrectly selected original will cause incorrect adjustment, at this stage it is recommended to use several different originals and compare the results obtained on them.

Occasionally, when you have to replace a defective control board board and at the same time you know for sure that its electrical part related to exposure control is intact and correctly adjusted, you can set the parameters of the new board in accordance with the resistances of the old one.

Many choose not to do this and re-exposure each time in such cases (see above), but since such a method exists, it is reasonable to briefly describe it.

1. Disconnect the machine's power cable from the mains.

2. Remove the copier, control panel cover, top panel, and finally the defective board.

3. Immediately mark it so as not to accidentally mix it up during measurements, which often happens in practice, especially when none of the compared boards has noticeable differences.

4. Set the Multimeter to a range of up to 200 kOhm and measure three resistances on the old board:

a) between the top contact VR602 and jumper JP607;

b) between the top contact VR603 and jumper JP621;

c) between the top contact VR604 and the top contact of the resistor R614 (Figure 2.58)

5. Get exactly the same resistances on the new board by rotating the appropriate trimmers.

6. Install the new board in the camera and check that the manual and automatic exposures are correctly adjusted.

Note. In devices that are not equipped with an automatic exposure sensor and have only one trimmer VR604, at the fourth step of the previous procedure, only the resistance between the upper end of VR604 and the lower contact of the resistor R614 should be measured (Fig. 2.59).

2.4.5. Image transfer system. sponge corotron

After the rays of light reflected from the original hit the previously negatively charged photoreceptor and formed a latent electrostatic image on it, and the toner particles from the magnetic roller were attracted and developed this image, it is necessary to transfer it to paper.

For this, a spongy transfer corotron is installed on the frame of the apparatus, to the left of the registration shafts. During the copying process, a negative charge is formed on it, which attracts the toner located on the drum. And since at this time there is a sheet of paper being fed between the shafts, all the toner falls on it and creates a copy of the scanned image.

The paper is then discharged with a corona needle to prevent static electricity from causing it to curl as it travels further down the paper path, and fed into the fuser where the toner fuses into its surface to form the final copy.

If the sponge corona were not negatively charged, but only served the function of pressing the sheet passing over it to the surface of the photoconductor, the adhesion of the toner and paper would not be enough to overcome the attraction of the toner to the drum, and the copy would come out almost white.

As a matter of fact, this is exactly how a malfunction in the power supply circuit of the transfer corotron manifests itself. If, during the initial diagnosis of a malfunction, it is noted that predominantly white sheets come out of the machine (or with very faint traces of the image) and the E-16 / E-30 combination cartridge is definitely not to blame, you should find out if the transfer corotron is energized or No.

Undoubtedly, in some cases, voltage is not applied to the corotron due to problems in the power supply. However, the main reason for this is a break in contact at the junction of the corotron with the output on the power supply board. The corotron is powered by a spring at its near end, directly connecting its metal shaft to the power supply board.

Most often, the contact breaks due to the separation of the spring from the bare contact on the board.

Sometimes, in order to save time when repairing the electronics of the power supply, the craftsmen turn on the device for testing, not only without returning the lower case panel to its place, but without even tightening the screws securing the combined board. In such cases, the front end of the board sags a little, which can cause the corotron feed spring to lose contact with the board.

As a result, the sheet will come out clean, and if the contact of the high-voltage terminals on the cartridge is also broken, then the copy may turn out, on the contrary, very dirty. This feature should be remembered: if you notice that unusually dirty copies have begun to come out of the device, then first of all you should check the contacts on the near side of the combination board, and not try to adjust the exposure, clean the optics or replace the cartridge.

In such cases, in order to avoid contact violations, craftsmen who are aware of this feature usually carefully press the edge of the printed circuit board with their hands, which in no way can serve as an example to follow, since high voltage passes on the board in the immediate vicinity and such delights can end in failure. It's better to spend a few seconds installing the screws than to run the risk of getting a high-voltage discharge every time.

If all the screws are fixed, but there is still doubt whether the contact of the spring with the board is sufficient, you can stretch the spring by removing the corotron from the mounts in the device.

Sometimes the near end of the board, even fixed with screws and latches, still continues to sag excessively. In my practice, there have been cases when, in order to be absolutely sure that the contact will never be broken in the future, I had to drill additional holes in the device to install another screw that presses the very edge of the board and thus eliminates even the slightest danger of its sagging.

The sponge transfer corotron spring may lose contact at its top. In this case, you should again remove the corotron and, having cleaned the place of their connection, ensure reliable contact.

If necessary, the sponge transfer corotron is removed from the machine as follows:

1. To gain access to the paper path, open the top door and place it vertically.

2. Press in turn the symmetrical plastic hooks 1 holding the sleeves of the transfer corona at both ends, lift the corotron 2 and remove it from the device (Fig. 2.60).

Note. Particular attention should be paid to the springs supporting the corotron from below. When removing the sponge corotron, care must be taken to prevent their loss.

3. During the subsequent installation of the corotron in place, make sure that the springs are even and that both ends of the corona corona are sufficiently well spring-loaded, being at the same level contaminated with toner.

If the master is still going to do this, he should remember that solvents or water cannot be used here. Wipe the spongy surface with a dry cloth. Usually so much toner accumulates in its pores that this procedure can take a long time, so it is recommended to remove excess toner by lightly tapping the corotron on the edge of the table or - if the master has a vacuum cleaner - vacuum the corotron and only then finally clean it using a dry cloth.

2.4.6. Determining the status of the top door of the machine and the fuser door. Microswitches SW1 and SW2

To avoid using the copier open, and in the interest of safety, the position of the top door and fuser outlet door are monitored by sensors that turn off power to the machine as soon as the doors are opened. At the same time, the backup power to the processor, which comes to it through the auxiliary transformer T101, is also turned off, even when the power button has not yet been pressed.

The PC-400/420/430 and FC-200/220 series machines use a new system that detects the state of both machine doors using a common microswitch and a mechanical lever fixed on the top plate of the fuser. This lever is very similar in design to the combined Front Door, Toner Cartridge and Power Switch registration lever of the Sharp Z-52 clone copiers.

In older models PC-300/320/325 and FC-200/230, separate microswitches SW1 and SW2 are used to control the position of each door, of which the first is mounted on the right side of the copier, near the feed unit, and the second, which is responsible only for the release door thermoblock, installed exactly where the common sensor is located on new models. With such a system, the microswitches are arranged in series in a circuit, due to which an unconditional power off of the device is achieved if at least one of them does not provide contact.

When repairing, it often becomes necessary to turn on the device with the top panel removed in order to be able to directly control the operation of internal components. In this case, the sensors are no longer fixed in the usual way, and they have to be clamped manually. It is most convenient to fix the upper door sensor in the old series of devices prevailing so far by first pressing it and pushing it down so that the closing ledge is pressed by the plastic frame of the device. During the final assembly of the apparatus, it is necessary to return the SW1 microswitch back, otherwise it will be a direct violation of safety regulations, allowing unskilled operators to freely gain access to the components that are in working condition and to the high voltage leads going to the E-16 / E-30 cartridge.

It happens that the reason for the defect declared when the copier was received for repair - lack of power - lies precisely in the sensors of the outer doors.

In such situations, the first step is to check how well the microswitches close and whether their wiring is intact. The easiest way to do this is to use a multimeter set to beep mode.

Sometimes, due to rust or due to the fact that, for example, the SW1 sensor was flooded with electrolyte from a burst capacitor on the power supply board, the contact defect appears randomly, in other words, it has a “floating” character. Therefore, it is recommended to check the contacts of the switches very carefully, simulating by hand the cycle of their closure up to several dozen times in a row. And even in this case, there is a small chance that the defect, not being noticed by the repairing engineer, will still manifest itself in the future.

The reason for the failure of sensors SW1 and SW2 may be mechanical damage to the parts adjacent to them. For a certain number of violations of electrical contacts, there is on average the same number of violations of mechanical contacts of parts.

The most common mechanical defect in the door position detection system in a similar Canon PC / FC-310/330/336 series was a break in one of the hooks on the release door of the fuser, due to which it ceased to fit snugly enough against the body of the device and the SW2 sensor opened. Fortunately, in the models of this series, the fuser door is designed a little differently, which practically eliminates the occurrence of any problems associated with it.

Here, the most common defect is a complex-composite structure, fixed on the inside of the top panel and designed to serve as a transmission link when the SW1 sensor is closed. The design includes a metal plate, a plastic part and a spring, interconnected rather unreliably and failing for many different reasons. Accordingly, when making decisions, you have to improvise.

Often there is another defect in determining the position of the upper door. Over time, the mechanism becomes loose, and its parts are somewhat erased, so that the pressure of the upper door in the closed state is literally a fraction of a millimeter insufficient to close the contacts of the SW1 microswitch.

In this situation, there may be several solutions. Many craftsmen follow the old proven path of gluing small squares of plastic to compensate for the resulting backlash on the lower surfaces of the recesses of the upper door, which is held in the closed position by latches. At the same time, it is necessary to ensure that the edges of the glued plates do not protrude beyond the edges of the recesses, otherwise the latches, when closing the upper door, will constantly touch the plates and eventually tear them out of the recesses of the door, as a result of which the defect will begin to appear again.

Let me remind you once again that all this applies only to those devices of the series in which separate sensors are installed for each door.

A mechanical defect of the sensor located on the thermoblock appears only in one case - when the latch breaks off from the plastic casing in which it is installed and through which it is attached to the thermoblock. The casing, together with the latch, is made of insufficiently plastic material and breaks easily, especially with clumsy attempts to remove it from the thermoblock, when, by depressing the latch, it is taken for a break. In the future, a broken casing can spontaneously shift and come out of the grooves of the thermoblock, a closed outlet

the door will stop closing the fuser and the copier will not power on. The fix is obvious. It is required to remove the top panel of the machine and replace the microswitch cover. If a broken latch is found in the device, you can try to glue it in place, however, the strength of the connection in this case is not guaranteed.

2.4.7. Damage to the manual exposure control

Careless installation of the top panel of the machine can easily damage the manual exposure dial located on the control board.

The plastic disc with divisions is attached directly to the trimmer resistor VR601 soldered into the board and, when the top panel is correctly installed, partially rises above it. The hole for the disk in the top panel is made very accurately, without unnecessary gaps, and with the slightest mistake made in installing the panel, the dimensions of the disk may not fit into the hole. In this case, the force that the assembler applies to the front of the panel to secure it with latches may be directed at the manual exposure dial and damage the resistor to which the dial is attached, the most fragile part of the structure.

Unfortunately, copying equipment is quite often subjected to unskilled intervention, so this defect is quite common.

It is noticeable immediately and manifests itself in the fact that the manual exposure adjustment dial is either completely recessed under the top panel, or it is very unreliable and, when pressed with a finger, noticeably oscillates. As for the actual manual exposure, the consequences can be very different here: it is possible that it will still be fully regulated, or at some positions of the dial failures will appear, or it will not be possible to adjust at all.

To eliminate the defect, it is necessary to remove the copier table, the control panel cover and the top panel in order to gain access to the control panel board and the regulator installed on it.

The plastic body of the VR601 is supported from below by two thin metal hooks. It is they who bend in the first place when excessive physical force is applied to them. As a rule, to eliminate the malfunction, it is enough to tighten the hooks and return them to a horizontal position, after which the regulator is in the desired position and stops staggering, and the resistor starts to adjust again. When assembling the apparatus, be especially careful to put the top panel back in place so as not to damage the already weakened regulator structure again.

If the damage is too severe to be repaired in the manner described above, then the trimmer should be replaced by removing it from the board. It seems impractical to change the entire board, especially since here Canon is deviating from its policy of replacing damage with entire assemblies and expresses its readiness to supply control board elements separately. The VR601 designation in the Canon parts catalog is VR9-3619-000 Variable Resistor, 10 KOhm.

2.4.8. Power unit. Short description. Weak spots

As practice has shown, the weakest point of the power supply turned out to be the auxiliary transformer T101, which constantly supplies power to the processor when the network cable of the device is connected to the power source.

The transformer is located at the far end of the board and has seven pins. As a rule, only the primary winding burns out. If it is damaged, whitish smoke may come out of the apparatus and the smell of burnt insulation may spread. When opening the device, the blackening of the transformer itself and a characteristic plaque on the board under it and around are usually immediately noticeable. Naturally, the first step is to check the resistance of the windings to make sure they are open.

The primary winding is called on the extreme contacts, the secondary - on the second and fourth. In devices for 220/240 V, the resistance of the primary winding is about 3.7 kOhm, and the resistance of the secondary is 12 Ohm. In 110/115 V devices, the primary winding, respectively, has approximately half the resistance.

After checking the resistance of the transformer, it is necessary to find out what voltage is supplied from the secondary winding of the transformer to the board. It should be within 6 ... 16 V for different devices. A voltage out of the specified range due to transformer winding faults can, for example, cause frequent transverse white streaks to appear on the copy.

In 110/115 V models, which the domestic market is saturated with, this transformer constantly burns out when the devices are inadvertently connected to a regular network without using a 220/110 V step-down transformer.

A burnt transformer should be replaced with a new one or the damaged winding should be rewound - depending on the capabilities of the service center or a private master.

According to the spare parts catalog, the T101 transformer can be ordered as FH3-0749-000 Transformer (100/115 V) or FH3-0753-000 Transformer (220/240 V).

The main, pulse, transformer T106 can also fail. If there are doubts about its serviceability, then after eliminating all other observed damage, it is recommended to replace it with a working one and look at the result. Due to the fact that pulse transformers do not burn out in the first place, they are not in short supply, and every service center probably has at least a few serviceable T106s on decommissioned boards. It is recommended to always have a spare transformer on hand for testing.

Fuses FU101 and FU102 also blow very often. The first fuse has a voltage rating of 250 V and a current rating of 2.5 A in 110/115 V models and 1.6 A in 220/240 V models. The second fuse can be rated 125 V, 10 A (110/ 115 V) or 250 V, 2.5 A (220/240 V).

Before replacing fuses, it is imperative to find the cause of their damage, since it rarely happens that they fail only due to an external voltage surge, while all other parts remain in good condition.

The Q147 diode bridge is relatively rarely damaged, but nevertheless, with complex defects in the power supply, it makes sense to ring it without first unsoldering it from the board. If all other elements are OK, the Multimeter should show normal resistances. And only in the case when a breakdown is detected during a rough check of the bridge, it will have to be soldered and checked separately. Often the diode bridge is intact, and the cause of the defect found during its initial check is some other part, for example, a broken Q158 field effect transistor. If the diode bridge itself is faulty, then it should be replaced by removing it from another board, selecting an analogue or ordering by the name Diode, Bridge, D2SB60 and part number WA1-0762-000.

There are very frequent cases when the key transistor of the Q158 pulse transformer fails. It is installed closer to the far end of the board, close to the metal ground plate, to which it is rigidly attached using a pressure plate on the screw. An insulating rubber gasket is used to prevent electrical contact between the transformer and the pressure plate. Contact with the ground plate is only needed to remove heat from this powerful and very hot transformer.

When it fails, transistor Q158 usually short-circuits, which can be determined without soldering it from the board. In this case, as a rule, the fuse burns out, and the diode bridge begins to ring from plus to minus with almost zero resistance.

With complex defects in the power supply, it is necessary to check the Q158 transistor almost in the first place.

To replace the key transistor, you need to unscrew the screw from the ground plate, remove the plate pressing the transistor and rubber insulation, and then unsolder the transistor from the board.

For 110/115V units, this FET is rated 2SK1202 and part number WA2-5006-000. In devices for 220/240 V, in position Q158 there is a 2SK1317 transistor, the catalog number of which is WA2-1527-000.

The reason why the copier does not turn on is often the protection transistors Q148 (2SD2088, part number WA2-1348-000) and Q149 (2SA950-Y, part number WA2-0317-000) that are fed back to the pulse transformer. They are difficult to check, even by soldering, since they can ring almost as good, but without replacing them, it will not be possible to eliminate the defect. There are their domestic counterparts KT502B and KT503, which are quite suitable, but they have the emitter, base and collector in a different order, so that before installing them, you have to bend the contacts accordingly.

Sometimes, along with these transistors, the D137 diode burns out, as well as a resistance of 18 ohms, position on the R284 board. As a rule, the field-effect transistor Q158, which has already been discussed, burns out with them. Occasionally, the paired capacitors C194 and C195 and the pulse transformer itself are damaged.

Finally, it is worth mentioning some defects in the power supply, due to which the device does not stop turning on, however, it malfunctions. These defects are also quite common.

It happens that the copier, with an absolutely serviceable cartridge, a properly adjusted control / exposure board, and with good contact of the terminals at the near end of the board, starts to constantly produce a black sheet.

The reason lies most likely in the high-voltage circuit of the power supply. It happens that the high-voltage diode D129 (Diode, SHV-02) explodes, leaving behind only two contacts soldered into the board, and this is precisely what leads to similar consequences. It is desirable to have some stock of such high-voltage diodes, since sometimes defects begin to appear literally one after another. There are about ten such diodes on one combined power supply board of devices of this series, so usually there is no need to specially buy the necessary stock - it is enough to have a pair of non-recoverable boards from which you can solder parts.

Occasionally, the following unusual defect begins to appear on the devices of the series: copies are made regularly, but at the end of the copy cycle, the M1 engine continues to rotate at low speeds. In this case, you should pay attention to the motor control circuit on the power supply board, especially the following three parts (designation according to the original spare parts catalogue):

Q102 IC, UPC339C, Comparator WA4-0041-000;

Q115 IC, M51971L, Speed control WA4-0558-000;

Q121 Transistor, 2SD1593 WA2-1434-000.

In case of malfunctions in the operation of the scanning lamp, when it either does not turn on at all, or is constantly on, starting from the moment the machine is turned on, it is necessary to check the scanning lamp control transistor 2SD2165L (WA2-6008-000), located on the board in position Q143. It's easy to spot because it's screwed to a zigzag tin plate that's also soldered into the board. Transistor Q143 should call from collector to base and emitter and from base to emitter and collector. If the Multimeter indicates the presence of conductivity between the emitter and the inputs of the transistor, then the transistor needs to be replaced.

2.4.9. Damage to the electronics system caused by insects

The greatest danger for copiers (after surges in the network and incorrect actions of the operator) are cockroaches.

Too often, company management turns a blind eye to the unsanitary condition of the workplaces of their employees and does not take any measures for periodic pest control. Smaller devices, which are cheap and therefore accessible to everyone, from heads of food warehouses to foremen at construction sites, suffer more than others. These devices are most often operated in places inappropriate for office equipment.

Such a careless attitude to the recommended operating conditions translates for the owners of equipment into constant expenses for expensive repairs. For repairing a copier turned into a nest of insects, service centers sometimes charge a triple price, or even refuse to repair it at all. Few people are pleased to collect dead cockroaches with a vacuum cleaner, and often to catch living individuals in complex interweaving of the nodes of the apparatus.

The owner of the device, applying for a warranty repair, all the more should take care that the master does not find the slightest trace of insect activity inside the copier, otherwise you will have to pay in full for the repair.

Therefore, we can recommend to all owners of copiers not to save money on maintaining cleanliness in places where sophisticated office equipment is used, so that there is no need to spend much larger sums on its repair.

Cockroaches use copiers both as shelter and as a source of heat, especially preferring the thermal block and electronic components on printed circuit boards that heat up during operation. At the same time, they close contacts on the latter, which often leads to very serious complex defects in electronics, in which up to a dozen radio components burn out.

The location of the thermal block and printed circuit boards inside the copier is very important. If the thermal block is resting on the base of the device frame, and the boards are lying horizontally, like, for example, the combined processor / power supply board in the devices of this series, the insects will feel quite at ease there. If the boards are placed vertically, and the fuser is suspended on the upper, reclining part of the bed, as in the Canon NP-6012 clone models described in Chapter 4, there will be practically no defects caused by cockroaches.

Cockroaches can affect the functioning of the copier in the most unexpected way. In this regard, one case from my practice is indicative. Having put another portable Canon on the desktop and checking the defect declared in the repair sheet, I set about initial testing of the device. The machine indicated a paper jam and refused to eject a copy. After removing the exposure glass and the top cover to check the condition of the output sensor, I found a live cockroach sitting in its optocoupler. The insect felt at home there, and was not going to leave its familiar place. Having removed it from the device and fanned the optocoupler with a brush, I assembled the device, confident that now everything would work. It wasn't there. The jam indication resumed at the same intensity. Since the correct operation of the output sensor was already ensured, I began to disassemble the copier from the other side in order to get to the optocoupler of the registration sensor. Having removed the bottom panel and tilted the combined power supply board, I found in the second of the sensors of the device exactly the same large live cockroach.

It is difficult to say what attracted insects in optocouplers - the generated radiation or a convenient form, but outwardly the situation was quite funny. After the expulsion of the second insect, the device started working.

2.4.10. List of symbols, digital and analog signals of the machine

1. Symbols on diagrams and tables

INTR Rollback of the copy table to the starting position, during which the gearbox mechanics makes a return movement

LSTR The final cycle in the movement of the table

CBFW Translational movement of the table during which the copying process takes place

CBRV Table return movement

STBY Idle mode of operation of the machine, in which copying is not performed

2 Digital signals in binary system (take values 1 or 0)

ASVTR AC Bias Timing Signal

CBSD Activation command for gear solenoid SL2

DCBPWM Primary Charger DC Control Command

DCTPWM Transfer System DC Control Command

DGT0 Pulsating signal 0

DGT1 Pulsating signal 1

DGT2 Pulsating signal 2

HTRD Heating element activation command

HVPAC Command to apply AC to the Primary Charger

HVPDC Command to apply direct current to the primary charge node

HVPHO Command to apply high voltage to the primary charge assembly

HVTDC Command to apply DC to the transfer system

KEYR0 Table position sender return Q902

KEYR1 Feedback from paper exit sensor Q801

LAPWM Scan lamp ON command MMCLK Signal from motor cycle counter Q901

mmd Engine start command M1

PWOFF Power off command

PWSON Power key beep

PUSD Feed Solenoid Enable Command

RELAYD RL101 relay command

RGSD Registration Solenoid Enable Command

TREV Transfer System DC Polarity Reversal Command

VPEAK Peak voltage detection signal

ZXDP Zero crossing signal

3 Analog signals (unlike digital signals, they cannot be expressed in logical units)

AE Signal coming from automatic exposure sensor

LID Signal from a sensor that measures the intensity of the scanning lamp glow

TH1 The signal coming from the thermistor and reflecting the current temperature of the thermocouple

2.4.11. Location of electronics components inside the device

Rice. 2.61 General power supply circuit of the apparatus units

The location of the electronics units inside the apparatus with tables is shown in fig. 2.62 - 2.65.

Sensors and solenoids

optocoupler

Q131 Paper pick sensor

Q801 Paper exit sensor

Q901 Engine speed sensor

Q902 Table position sensor

Photodiode

PD601 Scan lamp intensity sensor

PD602 Auto exposure sensor

Solenoid

SL1 Feed/Register Solenoid

SL2 Gear solenoid

microswitches

Switch

SW1 Top door sensor

SW2 Thermoblock door sensor

SW604 Power switch

SW606 Three position copy density switch

Motors and fusing electronics

thermoelement

H1 Heating element of the fixing unit

Thermistor

ТН1 Thermocouple temperature sensor

thermal fuse

FU2 Thermocouple overheating protection

Engine

M1 Main engine

Printed circuit boards

1. Combo board Controls the timing of processor/power supply processes, generates DC, high voltage

2 Control panel board Provides feedback to the copier operator

3. Scanning lamp line Contains scanning lamps (LA1-LA8), thermal fuse and exposure sensors

4 Paper exit sensor board Attaches the Q801 sensor

5 Engine speed sensor board Used to mount the Q901 sensor

6 Table position sensor board Used to mount the Q902 sensor.

Diagrams, tables.....

Today, copiers are a vital tool for many organizations and companies that have not yet switched to full internal electronic document management. The Xerox brand has long been a household name for all copiers.

However, we could have a domestic "copier". Attempts to create a similar technique were carried out as early as the mid-1950s, simultaneously with the development of Xerox itself. But the state then saw a threat to itself in the uncontrolled dissemination of data, so it deliberately hampered innovation.

"Xerox" Friedkin

Perhaps the most curious story is connected with the scientist Vladimir Fridkin, whose invention anticipated the development of the industry by a whole decade.

Fridkin graduated in 1952 with honors from the Physics Department of Moscow State University. But for a long time he could not start working in his specialty because of problems “on the fifth point”. The anti-Semitic campaign carried out at that time nullified the advantages of a red diploma.

Only a few months later, Vladimir Fridkin managed to get a job at the Research Institute of Printing Engineering, although initially he wanted to become a nuclear physicist.

At the research institute, Fridkin was given a completely empty office for work - there were only a table and a chair. It was not easy to do something productive in such conditions.

Vladimir Fridkin:

I didn't waste time. I went to Leninka, read magazines on physics, bought some equipment. I came up with the idea to implement a new photographic process in which the photoelectret served as a photosensitive layer, and the development was carried out using the triboelectric effect. The process was also conceived as a method for creating optical memory. The photoelectret not only formed, but also memorized the image. The latent image could be stored for quite a long time, and it could be developed long after the exposure. The layout was done quickly. I used polycrystalline sulfur and later other photoconductors like zinc and cadmium sulfide. The development was carried out with asphalt powder.

Vladimir Fridkin:

Many years later, I learned that in the United States, at the Haloid company, later renamed Xerox, the first models began to appear at the same time. But their work was based on a different principle.

Vladimir Fridkin, then only 22 years old, became deputy director of the institute. He received a good cash prize. They even shot a TV movie about the inventor, dedicated to the achievements of Soviet science.

"REM" and "Era"

A little later, other plants began to make similar devices - BelOMO and the Grozny Plant of Printing Machines under the Era brand. It is noteworthy that in Grozny they made small-format devices for A3 and A4, which worked not only with roll paper, but also with individual sheets.

The first Soviet-made copiers were also quite flammable. When the paper stopped moving, it almost immediately ignited under the action of a heat flux from an infrared emitter. In the premises where the equipment stood, it was necessary to install a special fire extinguishing system, and a carbon dioxide fire extinguisher was attached to the body of the apparatus.

Among those who worked with the devices "Eoa" and "REM", there was such a saying - "The operator who did not burn and did not extinguish the apparatus, like a tankman who was not in battle." When hiring, personnel officers seriously asked: “How many times did they burn?”.

Similar equipment was produced until the end of the 1980s. This is where the story of the Soviet "copiers" ended.

Vladimir Fridkin:

In 1965 Chester Carlson visited our laboratory at the Institute of Crystallography. The founder of xerography became interested in my articles. We were photographed together with an electret electric camera. In the late 1950s, Columbia University professor Hartmut Kalman and co-workers repeated my experiments on electrophotography on photoelectrets and found an interesting application for it in space communications. He spoke about this at a colloquium in Munich, where we met in 1981. For these works, the American Photographic Society awarded me the Kozar Medal, and the German and Japanese Society elected me an honorary member.

Now the inventor is 87 years old.

Soviet copy machine. A story about bugs in copiers. Motors and fusing electronics

"Xerox" Friedkin

"REM" and "Era"

"Xerox" Friedkin

"REM" and "Era"

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