Types and design of computer mice. What is a mouse and how does it work? Mouse purpose and operating principles

To solve one of the problems, I needed to programmatically obtain and process images of a small area of ​​the paper surface from a very close distance. Having not received decent quality using a regular USB camera and already halfway to the store for an electron microscope, I remembered one of the lectures in which we were told how various devices, including a computer mouse, work.

Preparation and a little theory

I will not go into details of the operating principle of a modern optical mouse; it has been written about in great detail (I recommend reading it for general development).

After googling information on this topic and disassembling an old PS/2 Logitech mouse, I saw a picture familiar from articles on the Internet.

Not a very complicated design of “first generation mice”, an optical sensor in the center and a PS/2 interface chip slightly higher. The optical sensor I came across is an analogue of the “popular” models ADNS2610/ADNS2620/PAN3101. I think they and their counterparts were mass produced in the same Chinese factory, with different labels on the output. Documentation for it was very easy to find, even along with various code examples.

The documentation says that this sensor receives an image of a surface measuring 18x18 pixels (400cpi resolution) up to 1500 times per second, stores it and, using image comparison algorithms, calculates the offset in X and Y coordinates relative to the previous position.

Implementation

To “communicate with the sensor” I used the popular Arduino computing platform, and decided to solder directly to the legs of the chip.

We connect 5V and GND to the corresponding Arduino outputs, and the sensor legs SDIO and SCLK to digital pins 8 and 9.

To obtain an offset by coordinates, you need to read the value of the chip register at addresses 0x02 (X) and 0x03 (Y), and to dump the picture you need to first write the value 0x2A at address 0x08, and then read it from there 18x18 times. This will be the last “remembered” value of the image brightness matrix from the optical sensor.

You can see how I implemented this on Arduino here: http://pastebin.com/YpRGbzAS (only ~100 lines of code).

And to receive and display the image, a program was written in Processing.

Result

After a little “finishing” of the program for my project, I was able to receive an image directly from the optical sensor and perform all the necessary calculations on it.

You can notice the texture of the surface (paper) and even individual letters on it. It should be noted that such clear picture quality is obtained due to the fact that the developers of this mouse model added a special glass stand to the design with a small lens directly under the sensor.

If you start to lift the mouse above the surface even a couple of millimeters, the clarity immediately disappears.

If you suddenly want to repeat this at home, to find a mouse with a similar sensor, I recommend looking for old devices with a PS/2 interface.

Conclusion

Although the resulting image is not very large, it was quite enough to solve my problem (barcode scanner). It turned out to be very economical and fast (a mouse for ~100 rubles + Arduino + a couple of days to write the code).

I will leave links to materials that were very useful to me for solving this problem. It really wasn’t difficult and was done with great pleasure. Now I'm looking for information about the chips of more expensive models of modern mice to obtain high-quality images with higher resolution. I might even be able to build something like a microscope (the image quality from the current sensor is clearly not suitable for this). Thank you for your attention!

Computer mouse is a very useful and convenient graphical information input device.

Currently, almost every personal computer is equipped with this device. The Windows operating system and all programs designed to work in its environment are entirely focused on using the mouse. Virtually all actions in Windows, except typing, can be done without using a keyboard, using only one mouse. Moreover, without a mouse, working with Windows becomes significantly more difficult and slower.

Structurally, the mouse is a streamlined plastic box containing:

    a massive rubberized ball that rotates when you move the mouse over a smooth surface;

    two or three buttons;

    mechanism for converting ball rotation into electrical signals;

    electronic circuit for receiving and processing data about the state of the mouse (mouse coordinates and button positions).

The mouse is connected to the computer system unit with a flexible cable. Sometimes, instead of a cable, infrared rays are used to connect the computer to the mouse. In this case, there is no mouse wire and does not interfere with work.

The figure shows the internal structure of the mouse manipulator. The figure shows the following required mouse components:

1. Photo emitter

2. Photodetector

3. Ball (usually it is covered with rubber for better grip on the table surface.)

4.Rotating roller

5.Press wheel

6.Button

7.Cable

8.Controller (special chip)

Currently the most common optomechanical mice . Their popularity is primarily due to their low cost. The rotation of the rubberized metal ball when moving such a mouse is transmitted to two rollers. One of them is located along the mouse, and the second - across. This is what “mechanics” consists of. The rotation of the rollers is converted into an electrical signal using optoelectronic sensors consisting of an LED and a receiver, between which there is a disk with slot-like slots mounted on the roller. As the disk rotates, the LED beam either passes through the slits or is interrupted, and pulses are formed at the output of the receiver. The built-in microprocessor counts them and generates a digital code that is sent through an interface to the PC, where it is processed by the driver. An optomechanical mouse has two unreliable elements. First, there is a mechanism that turns the movement of the ball into rotation of the sensor disks. Secondly, the connecting cable, which is constantly subject to bending during operation.

To eliminate the first drawback, instead of a ball, a number of modern mouse models use optical motion sensor . These mice have no moving parts, so they have high positioning accuracy. The first models of such devices were supplied with a special “lined” mat. When moving, the sensor worked like a primitive scanner, converting alternating dark and light areas on the rug into electrical impulses. Modern optical mice can work on almost any surface - the sensor responds to the natural uneven reflectivity of the material. Instead of a ball, a sensitive optical sensor is placed in it, capable of tracking the movement of relatively small textures on the sliding surface (mat, sheet of paper, etc.), invisible to the eye, not to mention scratches and other mechanical and color inhomogeneities. Their movement in the field of view of the sensor is converted by a specialized processor into an increment of linear coordinates corresponding to the movement of the user’s hand. The surface under the mouse is digitized at a frequency of 1500 times per second.

In previous articles we started telling you about computer peripherals. We started with the keyboard. Next in line is the mouse. In this article we will tell you about what a computer mouse is, what types there are and the main characteristics.

Computer mouse - an integral part of the computer. It allows the user to control the cursor, which is displayed on the screen, by moving the mouse itself across the table surface.

To put it simply, a computer mouse is a tool with which we can select and manipulate objects on the computer screen. Such actions include: copying, opening documents, selecting text, and much more. When using a computer, a person practically does not let go of the device, which proves the importance of this device.

What does a computer mouse consist of?

Computer mice, if you do not pay attention to the features of some types, consist of a scroll wheel, with which you can move (scroll information) on the computer screen, and keys that are used for such actions as, for example: activating the context menu, activating or opening object, grab and move it, etc.

On the underside of the mouse there is a sensor for tracking the movement of the manipulator on the surface. Depending on the type (will be discussed below), it can be a ball (almost not used in our time) or a laser scanner.

The mouse also has either a cord (with a USB or PS/2 interface) with which it connects to the PC, or, in the case of wireless mice, a compartment for installing batteries.

Types of computer mice

The computer mouse has come a long way in evolution and today we know the following types:

  • Mechanical - a type of mouse that is practically not used today. A device made of a rubberized steel ball, rollers and rotation angle sensors is used as a motion tracking sensor. As the mouse moves, the steel ball rotates; rollers are pressed against it, which record this and transmit information to the rotation angle sensors. The sensors, in turn, convert the received data into electrical signals. The disadvantages of such mice are their relatively large size and the need for periodic cleaning to work well. It also definitely needs a mat; without it it will be impossible to operate the manipulator;
  • Optical - differ from mechanical ones in that instead of a ball, to track movement, a “camera” is used, which photographs the surface on which the mouse moves at a frequency of several hundred frames per second. Analyzing the captured images, the cursor moves on the screen. In order to better highlight all surface irregularities, and therefore improve the quality of mouse positioning, a bright LED is used which is installed into the device at a slight angle;
  • Laser – an excellent alternative to the previous type of mouse. The principle of operation can be called identical to optical, only in this type, instead of an LED, an infrared laser diode is used for illumination. Thanks to this solution, the positioning accuracy of the device increases. Another advantage is that the type of surface is practically unimportant for the correct operation of a laser mouse;
  • Sensory - here the name speaks for itself. This mouse has no buttons or scroll wheel; all commands can be set using gestures. Touch mice are the newest type that are easy to use and amazing in appearance;
  • Induction - mice that work by using inductive energy. A mat that serves as a so-called graphics tablet is required;
  • Trackball mice - devices without buttons, which are controlled by an inverted ball called a trackball;
  • Gyroscopic — positioning of the cursor with such a mouse occurs thanks to a gyroscope. For these mice to work correctly, the surface is not important; they read information about movement not only from it, but from space.

Another way to classify computer mice is to divide them by connection method. This is how mice are:

  • Wired — connect to a PC using a cable via USB or PS/2;
  • Wireless — connection occurs using the Bluetooth protocol.

Characteristics of computer mice

Main characteristics of computer mice:

  1. Type (type) . As mentioned above, this affects the operation of the mouse itself, convenience and practicality. Each user chooses an item of use individually, since it is based on its purpose: there are those who actively play computer games - a gaming mouse is ideal for them, since it is equipped with additional keys for easy navigation. For others, a regular laser will be enough, with the help of which they will perform all the operations necessary for the average user.
  2. Size and shape . These characteristics primarily affect its practicality in use: the choice, in most cases, is determined by the size of the hand - girls love small and beautiful mice, men are used to feeling in their hands a weighty and rather large mouse, which will be convenient to control.
  3. Sensitivity . This criterion affects the accuracy of the cursor movement on the screen. More experienced users pay great attention to sensitivity, since, in addition to standard settings, some types of their activities require maximum precision and balance of movements, which can affect the result of the work.

conclusions

Today, the large number of types of computer mice presented allows each person to make an informed choice based on individual requirements. I hope that the article helped you learn a lot about such an indispensable item for a computer user as a mouse.

At this time, ordinary mice with a ball motion sensor are on the verge of extinction, they are being actively replaced optical mice.

In 1980, two independent inventors, Steve Kirsch and Richard Francis Lyon, demonstrated working samples of optical mice. Stephen Kirsch's mouse used an infrared LED, while Richard Francis Lyon's mouse used a visible LED.

The first optical mice to hit the market were developed by Hewlett-Packard in 1999 and sold under the Microsoft brand. Such a mouse could work on almost any surface and did not require periodic cleaning of dirt like conventional mechanical mice.

Soon after, other manufacturers began producing their own models of optical mice using components from Agilent Technologies, which was spun off from Hewlett-Packard.

Modern optical mice use the so-called optical correlation technology, in which a small video camera with a frequency of usually more than 1 kHz takes photographs of a surface illuminated by an LED and, by comparing frame-by-frame images, determines the direction of movement of the mouse. The surface on which the mouse moves (fabric, wood, plastic or a special mat) usually has micro-irregularities. These micro-irregularities are illuminated by a bright LED installed at a slight angle to the surface, due to which the micro-irregularities cast distinct shadows, which are reliably recorded by the mouse camera and processed by a specialized chip.

Optical mice usually use red LEDs, since they are cheaper and silicon photodetectors are more sensitive to red light; LEDs of other colors are less common.

The disadvantage of optical mice is their increased power consumption compared to mechanical and laser mice.

IN laser mice To illuminate the surface, it is not an LED that is used, but an infrared laser diode that illuminates the surface. Due to the coherence of laser radiation, focusing on the working surface is much more accurate and this mouse requires much smaller surface micro-irregularities to operate than is necessary for an optical mouse.

The laser mouse first hit the market in 1998, manufactured by Sun Microsystems, but was not widely used. Unlike an optical mouse, a laser mouse is capable of working on transparent surfaces such as glass and mirrored surfaces. In addition, theoretically, a laser mouse should provide better positioning accuracy compared to an optical mouse, although in practice their accuracy is almost the same, but for games it is often recommended to use a laser mouse, although this is a rather dubious recommendation, since all laser mice have a USB interface, and this limits the data transfer speed, and in addition, the question arises of the compatibility of USB laser mice with different operating systems.

Good afternoon friends!

Today we will talk about one very convenient device, to which we are so accustomed and without which we can no longer imagine working on a computer.

What is a "mouse"?

A “mouse” is a push-button manipulator designed together with a keyboard for entering information into a computer.

Indeed, he looks like a mouse with a tail. A modern computer is already unthinkable without this thing.

The “mouse” is much more convenient to use than, for example, the built-in manipulator of a laptop.

Therefore, users often disconnect this laptop “pad” and connect the “mouse”.

How does this convenient thing work?

The first designs of manipulators

The first manipulators included a ball that touched two disc rollers.

The outer rim of each disc had perforation. The shafts were located perpendicular to each other.

One shaft was responsible for the X coordinate (horizontal movement), the other for the Y coordinate (vertical movement).

When the manipulator moved along the table, the ball rotated, transmitting torque to the shafts.

If the manipulator was moved in the “right-left” direction, then the shaft responsible for the X coordinate rotated predominantly. The cursor on the monitor screen also moved right-left. If the mouse moved in the “toward or away” direction, the shaft responsible for the Y coordinate rotated primarily. The cursor on the monitor screen moved up and down.

If the manipulator moved in an arbitrary direction, both shafts rotated, and the cursor moved accordingly.

Optical sensors in old mice

Such devices contained two optical sensors - optocouplers. The optocoupler includes an emitter (LED emitting in the IR range) and a receiver (photodiode or phototransistor). The emitter and receiver are located at a close distance from each other.

When the manipulator moves, shafts with disks rigidly attached to them rotate. The perforated edge of the disk periodically crosses the radiation flow from the emitter to the receiver. As a result, the output of the receiver produces a series of pulses, which goes to the controller chip. The faster the mouse moves, the faster the shafts will rotate. The pulse frequency will be higher, and the cursor will move faster across the monitor screen.

Buttons and scroll wheel

Any manipulator has at least two buttons.

Double “clicking” (pressing) on ​​one of them (usually the left one) starts execution of a program or file, clicking on the other one launches a context menu for the corresponding situation.

Devices designed for computer games may have 5-8 buttons.

By clicking on one of them you can fire a grenade launcher at the monster, on the other you can launch a rocket, on the third you can unload a good old hard drive at it.

Modern mice also have a scroll wheel, which is very convenient when viewing a large document. You can view such a document only by rotating the wheel and without using buttons. Some models have two wheels scrolling, while you can view text or a graphic image by moving both up and down and left and right.

There is usually another button below the scroll wheel. If you view a document by rotating the wheel and simultaneously pressing it, the manipulator driver activates such a mode that the document itself begins to move up the screen. The speed of movement depends on how fast the user rotated the wheel before pressing it.

In this mode, the cursor changes its shape. This makes it even more convenient... In short, get it, cook it, chew it, all that's left to do is swallow it. Pressing the wheel again switches from “auto view” to normal mode.

Optical mice

Subsequently, the manipulator was improved.

The so-called optical “mice” appeared.

Such devices contain emitting Light-emitting diode(usually red), a transparent reflective plastic prism, a light sensor and a control controller.

The LED emits rays that, reflected from the surface, are captured by the sensor.

When the manipulator moves, the flow of received radiation changes, which is captured by the sensor and transmitted to the controller, which generates standard signals for a specific interface. Optical mouse more sensitive to movement and does not require a mat for itself, like the old ball manipulator.

An optical mouse has no rubbing parts (with the exception of the potentiometer, the rotation of which is transmitted from the scroll wheel) that wear out or become dirty. This is also an advantage.

Possible problems with manipulators

The mouse, like any equipment, has a limited service life. It's no secret that the bulk of computer equipment is made in China. The goal of any business is profit, so the Chinese comrades even save on cables for mice, making them as thin as possible.

Therefore, the first weak point of manipulators is the cable.

More often internal break one or more cores occurs at the point where the cable enters the mouse.

The cable has 4 wires, two of them are power, the third is clock frequency, and the fourth is information.

If the mouse is not visible to the computer, the first thing you need to do is “ring” the cable.

If a break is detected, you should cut off part of the cable with the connector (behind the point where the cable enters the mouse body, closer to the connector) and the remaining piece to the printed circuit board of the manipulator, naturally observing the color.

PS/2 Mice Can't switch on the fly .

Otherwise, her controller (her tiny “brain”) may fail. And it’s good if the matter is limited to just this. The PS/2 interface controller on the motherboard may also fail, which is much worse.

If the cable is intact, but the mouse is not recognized by the controller, then most likely its controller has failed and it must be replaced. A cable break in optical mice can also be suspected by the lack of light from the LED (which is located near the surface that moves on the table). In other cases, there may be no light due to a faulty LED or controller, but this is rare.

Manipulators with COM or USB interface Can switch on the fly. However, currently devices with a COM interface are practically not found.

You have to “click” the mouse many thousands of times, and the buttons may fail after prolonged use. To replace the button, you need to disassemble the manipulator and solder another one. It is not necessary to use the same one as it was. The main thing here is to maintain the height in order to maintain the length of the key stroke. However, manipulators have long been quite affordable, and most users do not bother with their repair.

Let’s say “thank you” to the good old “mice” with a ball in their bellies - they served us well...

Concluding the article, we note that there are varieties of manipulators with laser emitter instead of LEDs, which provide more accurate and faster cursor positioning. This speed and accuracy are especially in demand in games.

There are also wireless (radio) “mice” in which the exchange of information with the computer is carried out not over a wire, but over a radio channel. Therefore, they contain their own power source - a pair of finger-type galvanic cells of AA or AAA size. Let us remind you once again that the manipulator connector is inserted into one of the ports.

That's all for today.

Victor Geronda was with you.

See you on the blog!