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

Preparation and some theory

I will not go into the details of the principle of operation of a modern optical mouse, it is written in great detail here (I recommend reading for general development).

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

Not a very complicated scheme of "first generation mice", an optical sensor in the center and a PS / 2 interface chip a little higher. The optical sensor that came across to me is an analogue of the "popular" models ADNS2610/ADNS2620/PAN3101. I think they and their...

1 0

Optical mice: a variety of technologies

Sergey Asmakov

"Classic" optics

Laser instead of LED

Better than laser

"Blue-eyed" mice, version of Microsoft

In the dark field

Strictly vertical

"Blue-eyed" mice, Genius version

Conclusion

The vast majority of currently produced mouse manipulators use optical motion sensors. However, not all of them are arranged in the same way: several technologies have become widespread at present, each of which has its own characteristics. We will consider them in this review.

The mass introduction of optical sensors in mass-produced models began in the late 90s and made truly revolutionary changes in the field of computer manipulators. At first, optical mice were noticeably more expensive than models with a rolling ball and optomechanical sensors, but despite this, the new design quickly won the sympathy of users thanks to a whole...

0 0

Optical sensors for computer mice Avago Technologies

Avago Technologies is a new name in the global semiconductor market. Today it is the world's largest independent private semiconductor company. It was formed at the end of 2005. Then a deal was made to sell the semiconductor components division of Agilent Technologies to private investment companies - Kohlberg Kravis Roberts & Co. and Silver Lake Partners. In fiscal year 2005, Avago Technologies had 6,500 employees and generated $1.8 billion in annual net income.

Optoelectronics is an area where Hewlett-Packard and Agilent Technologies have been recognized leaders in the past. And now Avago is rightfully considered No. 1 in the world in the development and production of optical sensors for computer mice, red and amber LEDs for electronic signs and signal boards, optical motion encoders for inkjet, laser and...

0 0

Scheme

A simple computer mouse has a pair of optical sensors, they can be used for other purposes. The same sensors are used, for example, to determine the position of an object, whether a door is locked, or to read the number of revolutions of a shaft. The most optimal and convenient option is to use a ready-made board and microcircuit, especially when the system needs to use a microcontroller, they usually already have inputs to support the RS-232 interface. If you do not have such an opportunity, you can use the circuit which is listed above.

This sensor is divided into two parts: receiving (VD2) and transmitting (VD1). The transmitter is an LED that operates in the IR range, and the receiving part is a pair of photodiodes in one package. Two - are needed in order to be able to determine in which direction the mouse wheel rotates (up or down).

R1 - gives current to the LED. R2 is needed to convert the current ...

0 0

If your computer mouse is broken, do not rush to buy a new one. It is quite possible that you yourself will be able to fix the breakdown and the device will serve you for more than one year.

You can connect many various devices, however, there are two, without which it will be impossible to work with it. The first is the keyboard, without which the PC, most often, will not even boot. The second is a mouse. Without it, the computer, in principle, can be controlled, but it is very inconvenient to do this from the keyboard.

Throughout the history of the development of computer technology, a huge number of different manipulators have been invented and used: trackpads, joysticks, touchpads, etc. However, nothing simpler and more convenient than the well-known mouse has yet been invented!

The mouse is good for everyone, however, over time, like any technique, it can break down ... Fortunately, standard mice have a fairly simple design and can be repaired at home even by people who are far from electronics! If you have recently become...

0 0

First generation optical mice

Optical sensors are designed to directly track the movement of the working surface relative to the mouse. The exclusion of the mechanical component provided higher reliability and made it possible to increase the resolution of the detector.

The first generation of optical sensors was represented by various schemes of optocoupler sensors with indirect optical coupling - light-emitting and reflecting light-sensitive diodes from the working surface. Such sensors had one thing in common - they required a special hatching (perpendicular or diamond-shaped lines) on the working surface (mouse pad). In some models of mice, these hatchings were made with paints invisible in ordinary light (such rugs could even have a pattern).

The disadvantages of such sensors are usually called:
the need to use a special mat and the impossibility of replacing it with another. Among other things, mats of various optical...

0 0

The most popular computer accessory in the world is the computer mouse. Indeed, not a single desktop computer can do without it, it will seem rather difficult and inconvenient to work on your favorite laptop, and if you use a netbook that is not equipped with touch screen You just can't do without computer mouse! Since the beginning of the "computer age", people have tamed more than 350 million copies worldwide - the most different generations. It all started with an optical-mechanical mouse, inside which a metal ball covered with a layer of rubber rotated. In the conditions of a custom flat table, she “dwelled” exclusively on the rug and joined system unit PS/2 output. When moving, its ball could cling only to a rough surface. Of course, there could be no talk of any accuracy in the transmission of movements. Today, they have been replaced by real wireless cyber monsters with optical or laser motion detection, the highest movement accuracy and lightning speed.

0 0

The computer mouse is perhaps the most widespread and widespread computer device. Since its invention in 1963, the design of the manipulator has undergone fundamental technological changes. Forgotten are mice with direct drive from two perpendicular metal wheels. Nowadays, optical and laser devices are relevant. Which computer mouse is better - laser or optical? Let's try to understand the differences between these two types of mice.

Design

A modern mouse manipulator has a built-in video camera that takes pictures of the surface at an incredible speed (more than a thousand times per second) and transmits information to its processor, which, by comparing the pictures, determines the coordinates and displacement of the manipulator. To make the pictures better, the surface should be highlighted. Various technologies are used for this purpose:

Optical mouse

It uses an LED, the operation of which allows the sensor to receive better, and the processor faster ...

0 0

15/03/2006 16:30

Very often optical mice fly. MICHAIL

15/03/2006 16:34

Slav1969, but read something about the device, so the topic will disappear as irrelevant. The cost of a new mouse is 150 rubles. And you will dig into it for 50 rubles? vovsed

15/03/2006 19:42

I have the same bodyaga, it will stand with a stake and you won’t move. Odisee

15/03/2006 19:57

Where and how do they fly? And in what quantity?

Sometimes it happened that there was not enough ps / 2 power for the optics, but this was on old mothers such as via694, etc. (from personal experience).

16/03/2006 10:19

If the lace is in order, then usually it cannot be repaired! ...(Where can I get optoassemblies?) ...it's easier to buy a new one! Konstantin

16/03/2006 10:36

And cheaper than s / h + work. Slayer

16/03/2006 10:52

Of course... slav1969

16/03/2006 12:09

And if these mice fly in batches and about optoassemblies ...

0 0

10

Computer mouse device

Computer mouse device. Many already cannot even imagine how you can work on a computer without a mouse. But until recently, a computer mouse could not even be dreamed of. But those who worked on the computer knew the keyboard well. And with the advent of mice, many do not even know how to get out of the situation if the computer freezes. And now there is such a variety of these devices that sometimes it’s not immediately clear that this is a computer mouse. But, despite this, the internal structure of such mice is not much different. I do not think that anyone thinks about the internal structure of a computer mouse, but for general development it is still necessary to know.

What is the device of a computer mouse?

A computer mouse is a small box for entering information into a computer, and easily fits in your hand. For manipulation, there are at least two buttons and a scroll wheel. Who first called her a mouse is not so important now.

The important thing is that this name is good...

0 0

11

"Bloody rodent": Review of the gaming mouse Bloody T7

The review got a mouse for gamers from the company A4Tech - Bloody T7.

A4Tech specializes in the production of keyboards and mice, headsets, joysticks, steering wheels, headphones and other computer peripherals. A gaming mouse with a bloody name - Bloody T7 - ​​came to the bigmir)net editors for a review. What it is - read in our review. And we thank A4Tech for providing the mouse for testing.

The Bloody game series includes 42 titles. The series includes both mice and keyboards, headsets and mats. A distinctive feature of Bloody is the "bloody" design. All products in the series have a red palm print logo.

Characteristic

First, dry numbers.

Sensor type: Optical Resolution DPI/CPI: 4000 Dpi Polling rate: 1000 Hz Acceleration (maximum acceleration): 23 G Number of buttons: 9 Backlight: Yes Internal memory: 160 Kb ...

0 0

12

What is the difference between a laser mouse and an optical mouse?

Computer techologies are rapidly developing. Innovative processes did not pass by and mechanical manipulators, habitually called by us "mouse". The time has passed when the presence of a third key on a ball mouse was the top of the design idea. Now there is a huge selection of mice of various sizes and colors, wired and wireless, optical and laser. Of course, choosing a mouse based on its design will not be any problem, but not every user can explain the difference between an optical mouse and a laser one. The main difference for many people will be the fact that laser mice are more modern and therefore better. This, of course, is not disputed, but the differences between them are much more significant.

An optical mouse is a manipulator equipped with a very small video camera. It takes about a thousand pictures per second. This data is from...

0 0

If the mouse is moved faster and faster, then at a certain speed of movement, it will begin to move. This may be accompanied by a decrease in sensitivity, an increase in instability and randomness of movement, and other "bad things". I really liked one model of the Logitech office mouse - with a sharp movement, you could find yourself looking straight at the floor and spinning at the same time. A very interesting situation at the time of the fight on Flak "ah. I will consider this question during practical testing of real mice, there is nothing much to theorize about here.

Instability

The mouse, by its very nature, is a mechanical device. So it is characterized by instability, buzzing. These are small chaotic (random) movements. The defect itself can be static and dynamic. Static is manifested in the fact that the mouse leaves an uneven track at a low speed of movement. Another defect with the same cause is the spontaneous movement of the mouse. The nature of the defect in the image noise of the displacement sensor. There are many ways to treat the disease, and all of them are to some extent related to filtration. The defect of spontaneous movement, which was characteristic of mice of early releases, does not seem to appear now. This is good? Not at all.

advertising

The motion sensor still produces noise, but the mouse controller uses a special algorithm that blocks the movement of the mouse at ultra-low movement speed with a delay in execution. The delay is needed so that the user does not get the mouse to stop when he himself began to move it too slowly. This algorithm can be implemented in different ways, so don't be surprised by the "strangeness" of the new mouse, when you can't hit the icons - due to the delay, the mouse does not start moving from the moment you start moving your hand. Moreover, the amount of delay may depend on the speed. As a result, two unpleasant events occur at the same time - the mouse "suddenly" jumped, and if the setting in Windows "increased pointer accuracy" is enabled, the jump will be especially sharp. The matter is that "increased accuracy of installation of the pointer" is connected with dynamic acceleration. And if the mouse "jumped", then it is immediately set to an increased speed. After the jump, dynamic acceleration sees no change in mouse speed, so the dynamic speed decreases.

In practice, it looks like this - at first nothing, then a jerk, then a normal movement. This happens quickly and is not noticeable to the eye, but is clearly noticed by the hand - working with such a "gift of fate" does not bring joy. This defect is clearly visible if, immediately after such a mouse, you pick up an old, old LED mouse and try to work on it. Fortunately, not everyone will notice such a defect. If so, then you're in luck. But there are those who will not be able to use mice with such "smart" algorithms. Since this defect is bad for work, what can we say about using such a mouse in games?

Dynamic instability has the same roots as static instability - image noise. But to them are added the unevenness of the surface on which the mouse moves. Struggling with inconsistency different ways adaptation. Usually this is achieved by controlling the laser current and the gain (brightness) of the signal from the matrix. But here everything is more confusing and more complicated, a banal mouse stop is not enough, as is done to eliminate static instability. Although they are trying - some manufacturers are introducing "improvers". For example, there is an algorithm to align the movement of the mouse if it moves in a straight line. Well, yes, on tests it will be beautiful - once and a straight line without any garbage and jitter. Time and time again, but try to play this miracle? "We think for you." No thanks, keep it to yourself.

Let me explain a little about the relationship between noise and accuracy. The fact is that the sensor sees the surface differently than a person. Firstly, there is infrared, invisible, illumination. Secondly, this illumination is laser coherent. Thirdly, the window size is about 0.7 mm, which is very small. Any "breath" and the picture changes.

Enough theory, let me give you an example.

Let's take the ring and make it move.

Movement is clearly visible. Now let's compare two neighboring frames:

One frame at the top, the next at the bottom. One is shifted relative to the other by 1/4 pixel. (In order not to squint, I enlarged the picture by 8 times, keeping the format of splitting the sensor matrix)

Okay, can you clearly see the difference between the top and bottom? Clearly?

Now let's add some real noise. In order not to simulate "it is not clear what", I will give the real pictures taken.

When shooting, the mouse was clearly fixed, but the control program in this version is not able to take more than one picture at a time, which can cause brightness to "bounce". Do not pay attention. Although, it may not be in the program, the issue has not been investigated.

So far, we can conclude from this that minor shifts between adjacent images are difficult to identify by the sensor. I draw your attention - it is the sensor. The mouse controller does not have access to the picture. The reason is the noise that is inherent in any analog equipment. And here it is worth mentioning another parameter of the sensor - the shooting speed, the frame rate per second.

frame rate.

Frame rate is the frequency of shots. It follows from the above that it is necessary to choose the frequency of shots in such a way that there is a significant change in position between adjacent frames. On the other hand, this change should not be too large, otherwise the sensor will not be able to understand which of the frames is the reference one. The minimum frame rate is 2000, the maximum is slightly more than 7000. Let's deal with the numbers.

With a low movement speed, less than 1 cm per second, and the minimum allowable frame rate of 2000 frames / sec, an image shift of 0.005 mm is obtained. The sensor matrix has 30*30 points. At 0.005 mm and a visible window size of 0.5 mm, this will be 1/140 of the window or 1/4 of the matrix point. This is exactly what is shown above in the simulation animation of the movement of the ring. What if you move the mouse even slower? But this is what happens when you need to do something very accurately - hit or draw a line. Here already 1 point accounts for far from 1/4, but much less. And this means that the contribution of noise increases. It is impossible to reduce the Frame Rate less than 2000, so the sensor said. So what? ... yes, no good, the mouse will tremble.

On the other hand, with an increased Frame Rate, the controller itself can poll the sensor more often and average the read values. This significantly reduces noise. The theory of errors says that when taking N measurements and averaging them, the accuracy increases in proportion to the root of N. Therefore, it is effective not to take too many measurements for averaging - the time increases, it is directly proportional to N, but the accuracy almost does not improve.

Modern mice operate on the USB interface, so their response quantization is selected from the range of 125-250-500-1000 samples per second, which sets the number of averaging samples to 16-8-4-2. Thus, a mouse at 125 Hz is much more stable than 1000 Hz, other things being equal. Therefore, it is hardly worth chasing a very high interface speed, it will come out sideways. More precisely, it already goes sideways - noticeably. The mouse is unstable.

advertising

The A4 X7 laser mouse controller always reads the sensor at a rate of 1000 times per second. With a minimum snapshot frequency of 2000, this already means the loss of 50% of the information that could be sent for averaging. An alternative is to apply smart noise filtering. Averaging and filtering have common roots, but different efficiency of the algorithms. At low speeds, the degree of filtering should be greater (I remind you that too high a minimum Frame Rate harms), and at high speeds it can be reduced. In addition, dynamic instability must be filtered out at high speeds. But "filter", and not "correct for me", as is customary in "improvers". By the way, any filter introduces a delay in obtaining samples, so filtering should be done smartly.

In the old office mice there was no filtering and "cleverness". And what a joy it is to play them.

DPI switch

In laser mice, especially gaming mice, they began to set the DPI switch (dots per inch). Actually, this term is incorrect and now it is being replaced by CPI (count - the number per inch). I will use the term DPI where it is explicitly stated in the inscriptions or specifications, although this is not entirely correct.

So what is CPI? This is the number of readings (points) that Windows will produce when moving one inch (25.4 mm).

advertising

The more CPI, the better the mouse seems to be? For example, in the A4 in the X7 series, laser mice have 2400-3600dpi each. And this despite the fact that the sensor cannot produce more than 2000 cpi. Nonsense? ... but where does the A4 get these numbers from? Yes, exactly from the same place where the displacement sensor takes them from. He, after calculating the most probable movement of the image on the matrix, gets some kind of abstract number. Let's assume that this number is between 0 and 1. The sensor multiplies it by the set cpi value and outputs it to the controller. (Although, it's the opposite here, the controller reads information from the sensor.) What prevents the controller from also multiplying by an arbitrary number? Up, and got a "cool" mouse. Cool - cool, only fig. Because of the noise, the sensor can determine the image shift with some limited accuracy.

For the ADNS-6010 sensor, Avago claims a typical accuracy of 2300 cpi. This means that when the sensitivity is set above 2300, the sensor error will exceed one count. Average. For a particular mouse, this number can vary within certain limits and depend on many random factors - the state of the surface, the clarity of the fixation of the optics block, the aging of the laser, the cloudiness or dustiness of the optics. One thing can be said more or less reliably - it will not be better than 2300 cpi.

If you set a small resolution in the mouse settings, much less than 2300 cpi, then the mouse will behave very clearly and predictably, but who will be pleased with a laser mouse with a resolution of 600 cpi? But "3600" cpi brings no more joy.

One feature of the cpi setting that the A4 X7 series mice follow is that they set the sensor setting "from the edge and above." Those. for resolutions 400-799, the resolution of the sensor is set to 400, for 800-1599, the sensor is set to 800, etc. Therefore, to get rid of unnecessary extrapolation, it is recommended to set the resolutions inherent in the sensor hardware settings - 400, 800, 1600, 2000 cpi.

Let's finish this today. In the next part of the material, you will find testing of several common mice. And she will complete her material on assembling a mouse with improved characteristics. To be continued...

The so-called "mice" are an integral part modern computer. With the advent of new ones, old ones that are still functional, but morally obsolete, as a rule, are thrown away or gather dust idle in the pantry. However, they can be used without practically changing the electronic filling. It is quite easy to do this.

"RED EYE" TURNS ON THE LIGHT

You won’t surprise anyone with original light switches today, but the one below - from an optical computer mouse, in my opinion, is unusual and convenient in a city apartment for several reasons:

Firstly, the miniature mouse fits well into the socket under the regular key switch on the wall;
- secondly, direct contact with the switch is not required - it is enough to swipe your finger (or other object) at a distance of 1.5 cm from the "red eye" of the backlight;
- thirdly, the device initially has a trigger effect: once held a finger - the light caught fire, spent the second time - turned off;
- a response indicator is also provided - when you swipe your finger at the "backlight", it lights up three times brighter.

A simple current amplifier on a transistor with an executive relay in the collector circuit is added to the optical computer mouse so that the signals from the mouse control a lighting lamp with a power of up to 200 W (limited by the relay parameters) - more on that below. Since almost all computer optical mice are built according to the same scheme and principle of operation, let's consider one of them - Defender Optical 1330, shown in photo 1.

Photo 1. View of the Defender Optical 1330 optical mouse with the housing cover removed

Photo 2. The printed circuit board of the optical mouse Defender Optical 1330 from the side of the optical lens

Photo 3. RX-9 transceiver of a set of wireless keyboard and optical mouse

Photo 4. Installing a wireless mouse to guard the safe

Photo 5. Siren KPS-4519 as an audible alarm

The main coordinate positioning device is a microassembly with the designation U2 А2051В0323, combined with a photodetector (in one housing). From output 6 of this microassembly, pulses with a frequency of about 1 kHz are constantly received by the red LED, so even when the optical mouse is motionless on the table, a red, barely flickering "backlight" is visible. However, its value is not only to highlight the place occupied by the mouse - for beauty. The LED is a transmitter, and the microassembly itself with an electronic assembly built into its housing serves as the receiver. When light signals reflected from any surface reach the photodetector, the voltage level at pin 6 of U2 drops to zero, and the LED lights up in full force. It is this reaction that we see in a mouse on a computer table when we try to move it.

Full LED burning time is 1.3 s (if there are no longer mouse actions). One of the main parts of an optical mouse, oddly enough, is not electronics, but a plastic lens, curved under a certain radius (see photo 2), without it the mouse "blinds".

It is necessary to install the mouse in the wall niche under the standard switch in the assembled case, which securely fixes the optical lens from the base (substrate) side of the mouse.

When a signal reflected from an obstacle (your finger, palm) arrives at the photodetector, the level of the logical signal changes to the opposite on pins 15 and 16 of the microassembly U1 NT82M398A (and, accordingly, on pins 4 and 5 of the microassembly U2). Moreover, these are not inverse conclusions, but independent of each other. The signal change on them occurs depending on the vertical or horizontal movement of the mouse. The control signal for the actuator (low level changes to high, pin 15 U1 and pin 4 U2) is connected to the actuator, to point A.

The transistor opens and the relay turns on at a high logic level at point A. Diode VD1 protects the relay winding from reverse current surges. Resistor R1 limits the current in the base of the transistor. The relay can control not only a lighting lamp, but also any load with a current up to 3 A. The power supply is stabilized, with a voltage of 5 V ± 20%. The transistor can be replaced with KT603, KT940, KT972 with any letter index, and the K1 executive relay can be replaced with RMK-11105, TRU-5VDC-SB-SL or similar for an actuation voltage of 4-5 V.

Rice. 1. Current amplifier with an executive relay that controls the load in the 220 V network

Rice. 2. Scheme of the adapter for sound signaling the opening of the safe

The four-wire cable is partially soldered from the board at the junction with the standard connector and two wires are soldered (green and white to pins 15 and 16 of the U1 microassembly from the side of the elements (not printed wiring), otherwise the wires will interfere with the installation of the board in the mouse case.

The initial wiring of the connector on the mouse board: 1st output - common wire, 2nd output - power supply "+5 V", 3rd and 4th - output pulses.

If the circuit and printed circuit board of your mouse do not correspond to the one shown in the Defender Optical 1330 example, it is enough to take any oscilloscope or logic probe (indicating at least two main states - high and low) and experimentally find points with a control signal on the board.

Any optical mouse for a PC will do, so it doesn't matter which connector is at the end of the connecting cable of a computer mouse, you still have to remove it. You can also use wireless mice (with signal transmission over a radio channel, for example, from the A4 TECH kit - mouse adapter RX-9 5 V 180 mA), in terms of positioning coordinates, they have the same principle of operation as wired ones.

MOUSE GUARD

Now a new wave of generational change of the widespread computer manipulator is coming: "tailed" (with wires) optical mice are giving way to their wireless counterparts. For example, the RP-650Z wireless optical mouse manilulators, complete with a wireless keyboard (with an ergonomic arrangement of the main keys and 19 additional reprogrammable buttons), are relevant. The Agilent Technologies sensor used in the RP-650Z mouse is the market leader in this sector.

The optical resolution of the mouse is 800 dpi - this is quite enough for good work. A radio signal transceiver and an AA battery charger with a quick charge switch are housed in one housing (photo 3). This unit connects to a USB port.

A4Tech marks its manipulators with an individual electronic code, thanks to which up to 256 manipulators or keyboards can coexist on one receiving channel. Such a technical solution narrows the data transmission bandwidth, but with a maximum reliable reception radius of 2 meters, this is not critical.

An unusual option for using a wireless mouse - as a signaling device for opening a safe, working washing machine and even ... a refrigerator is presented below. All of these options are based on the micro-displacement of the subject and even on the detonation effect. When you install the mouse on a metal door, you get a signaling device for its opening or impact (another use case).

I should note that a no less effective signaling device can be obtained if an automobile shock sensor is installed on the controlled surface as a mouse; it is also triggered by detonation or mechanical impact on the controlled surface, and its modern models even have several levels of sensitivity adjustment. In a computer mouse, this option is not, by definition, its first and main purpose, but this is not important; for we are considering an unusual application of it.

I installed an RP-650Z wireless mouse (A4Tec11) on the front wall of a safe that stores hunting weapons, although you can store anything in it (photo 4).

The safe is in a built-in closet (a niche in the wall of a city apartment); thanks to wireless technology, there is no need for wires. Within 2 meters there is a radio signal transceiver (see photo 3), which is connected to an adapter device (diagram in Fig. 2).

The pinout of the connector for the USB port does not differ from the above option. In the RP-650Z wireless mouse, the control signal (when the mouse is moved, the level in this model changes from high to low) is taken from pin 4 of a single UM1 microassembly (designation on the board). Therefore, in this case a different current amplifier circuit will be required (see Fig. 2). Now, when opening the safe and even any mechanical impact on it (displacing the sensor-mouse by fractions of a millimeter), the security device will work.

As HA1, a sound capsule with a built-in audio frequency generator is used, it must be connected strictly in accordance with the polarity. Transistor VT1 p-n-p conductivity opens when the voltage at point A is close to zero, that is, at the moment the mouse is displaced. You can also use the KPS-4519 siren (photo 5), because with the 12 V power supply it gives a sufficient sound volume to be heard in neighboring rooms (more than 80 dB). It is necessary to connect the siren in accordance with the polarity (red wire - to the "+" power supply).

Two words about mouse pinning. On the lower part of its body, without closing the LED and the lens, a magnet is glued (from advertising fridge magnets). Now the mouse is securely fixed on any metal surface (refrigerator, washing machine, etc.). If you try to remove it, an alarm will also go off, informing the owner of unauthorized access to the safe.

Thanks to "wireless" the user has the ability to install the mouse in any way, removing it from the receiver at a reasonable distance, without worrying about the connecting wires. There can be as many options for using this technology, and they are limited only by your imagination.

Read and write useful

#Sensor_type

It is generally accepted that the laser sensor of the mouse is better than the optical one, but in fact it all depends on the tasks performed on the computer. If absolutely precise positioning is required from the mouse at any speed of its movement, then optical mice have advantages. For this reason, optical mice are best suited for professional gamers, designers, and photographers. Typically, optical manipulators are combined into a group of gaming mice, since it is gamers who are their main buyers. If the mouse requires versatility, that is, work on any surface and sufficiently high accuracy, then devices with laser sensors are preferable, which are popular among novice gamers, office workers and among those who travel a lot with a laptop.

Gaming sensors of average quality

Pixart Avago ADNS9800
Pixart Avago ADNS9500
Pixart Avago A3090
Pixart Avago A3059
Pixart Avago AM010
Pixart Avago PMW3320
Pixart Avago ADNS-3095
Pixart Avago ADNS-3888

Professional gaming sensors

Pixart Avago PMW3310
Logitech Mercury
Pixart Avago S3988
Pixart Avago PMW3366
Pixart Avago PMW3360
Pixart Avago PMW3389

Let's try to explain the above. The heart of any computer mouse is the sensor, which is responsible for registering the movements of the mouse on the surface. When operating systems with a graphical interface, the most common way to register the movements of the ball mice used at that time was an optical-mechanical sensor. Due to low accuracy, exactingness to the working surface and the need for very frequent cleaning, such mice have gone down in history, giving way to modern optical and laser sensors. Strictly speaking, the division into optical and laser mice is rather arbitrary. The principle of operation of optical and laser mice is the same, the difference lies in the type of light source. In optical mice, this is a regular LED, and in laser mice, it is an infrared laser. In what follows, if clarification is not required, we will use the terms "optical mouse" and "optical sensor".

So what is an optical sensor? The answer to this question is simple - it is a light source, a miniature video camera and a special microcircuit that registers the direction and speed of the mouse movement on the table surface. The registration process is as follows:

1. The light source, located at an acute angle relative to the underside of the mouse, creates shadows in areas of micro-roughness found on almost any surface, increasing the contrast of the image.
2. The miniature camera takes pictures of the work surface at a very high frequency (10 kHz or higher)
3. The chip sequentially, frame by frame, analyzes the received images and converts them into changes in the cursor coordinates.

Due to the lower cost of red LEDs and the greater sensitivity of silicon photodetectors to red, almost all inexpensive optical mice use a red LED as a light source. In more advanced models, LEDs of other colors can be used, including those emitting light in the spectrum invisible to the human eye.

As mentioned above, laser mice use an infrared laser diode as a light source. Due to the coherence of laser radiation, focusing on the working surface is much more accurate and this mouse requires surface microroughness with a much smaller size than is necessary for an optical mouse. For this reason, a laser mouse is better suited for everyday use, as it works equally well on both a cloth pad and a glass surface.

When it comes to computer games, then the accuracy of laser sensors becomes redundant. The problem is that laser computer mice collect useless information, so moving the mouse slowly causes cursor jitter. Tracking errors are due to redundant data being sent to the computer. Despite the fact that engineers are struggling with this feature of laser sensors, and not without success, laser mice still cannot boast of ideal positioning accuracy in games. For this reason, professional esports players often choose optical mice with the most advanced sensors.

The vast majority of currently produced mouse manipulators use optical motion sensors. However, not all of them are arranged in the same way: several technologies have become widespread at present, each of which has its own characteristics. We will consider them in this review.

The mass introduction of optical sensors in mass-produced models began in the late 90s and made truly revolutionary changes in the field of computer manipulators. At first, optical mice were noticeably more expensive than models with a rolling ball and optomechanical sensors, but despite this, the new design quickly won the sympathy of users due to a number of important advantages. First, due to the absence of moving parts, the optical sensor is much more reliable than the optomechanical one and, moreover, does not require regular cleaning. Secondly, optical sensors provide higher accuracy: even in the first models, this indicator was at least 400 cpi (counts per inch - counts per inch). If we operate with more familiar units of measurement, then this means that the manipulator is able to fix the movement of only 0.06 mm. Thirdly, optical sensors work stably on a variety of surfaces. In many cases, this made it possible to abandon the special mats that were an invariable attribute of the PC user's workplace in the era of mice with optomechanical sensors.

Recall the principle of operation of an optical displacement registration sensor. Regardless of the implementation, it includes three main components: a light source, a miniature video camera, and a dedicated microprocessor (DSP). A miniature video camera within just one second is capable of capturing up to several thousand images of the surface along which the manipulator moves. Bright illumination is required to obtain sufficient contrast images at this frequency. Typically, a LED with a focusing lens or a low-power semiconductor laser is used as a light source. The images taken by the camera are converted into digital form and transmitted in a continuous stream to the DSP, which processes this data in real time, calculating the direction and speed of the movement of the manipulator.

A miniature video camera, an ADC and a specialized processor are combined in one microcircuit (Fig. 1), thanks to which mice with optical sensors are simple in design and can be made in a very compact and lightweight package (and not always resembling a familiar mouse - take, for example, a mouse that is put on finger model Genius Ring Mouse, shown in Fig. 2).

Rice. 1. The main "sense organ" of the optical mouse -
microprocessor chip with built-in video camera.
To the right of it are the LED and the focusing lens.

Rice. 2. Original mouse
Genius Ring Mouse is so small
that it can be worn on the finger like a ring

By the way, “underweight” creates a specific problem: an overly light manipulator can spontaneously move around the table, carried away by the weight of the cable used to connect to the PC. That is why metal weight plates are installed inside the case of many models with a wired connection, and the design of some gaming mice allows you to adjust the weight of the case by installing removable cassettes with a set of calibrated weights. In models with a wireless connection, such tricks are usually not required: the batteries or accumulators that power the mouse act as a ballast.

The technology used in optical motion sensors is constantly evolving. The developers of many companies are engaged in improving existing structures, as well as creating and implementing fundamentally new solutions. Of course, within the framework of this review, we will not consider all the technical nuances, including because many of them are the know-how of manufacturers and information about them is kept in the strictest confidence. However, for our purposes this is not required. To understand the fundamental differences between optical motion sensors of different designs, it is enough to pay attention to the following features:

• the type and wavelength of the light source used;
• the angle of inclination of the beam emitted by the light source (light beam) relative to the plane of the working surface;
• the angle of inclination of the optical axis of the lens of the sensor video camera relative to the plane of the working surface;
• and finally, on what kind of light enters the camera lens - scattered or reflected from the working surface.

This concludes the introductory part and proceed to consider the various types of optical sensors used in modern mice.

"Classic" optics

The design of the optical motion sensor, which in the late 90s and early 2000s replaced the rolling ball optomechanical system (and, by the way, is still widely used), was developed by Agilent Technologies engineers. The scheme of its device is shown in fig. 3, and the appearance - in Fig. four.

Rice. 3. Scheme of the device of the optical sensor
traditional design

Rice. four. Appearance optical sensor with red LED.
The camera lens is visible on the left side

Let us consider the distinctive features of the described version of the optical sensor, which, for clarity, we will further call the optical sensor (or sensor) of the traditional design.

As you can see in the above diagram, the light source is a red LED. Since this semiconductor device generates a fairly wide light beam, and a small area (less than 100 mm 2) is required to illuminate, a focusing lens is used to increase the efficiency of using light energy. The light beam focused by this lens illuminates the work surface at a rather sharp angle - approximately 25°. This is done specifically in order to obtain a distinct cut-off pattern even on surfaces with a slight microrelief. The optical axis of the camera lens of such a sensor is perpendicular to the plane of the working surface and thus reads the scattered light.

Today, mice with optical sensors of traditional design form the basis of the computer manipulator fleet, and are operated both with desktop and portable systems. On sale is the widest range of such models with both wired and wireless connections, which makes it easy to choose the right option for every taste and budget. Due to large volumes of production, the price of these devices has significantly decreased: junior models of manipulators with a wired connection can now be purchased for only 100 rubles. And even such a mouse is quite capable of serving its owner for several years, requiring little or no maintenance.

Of course, along with the advantages mentioned above, mice equipped with traditional optical sensors have certain disadvantages. First of all, this concerns “all-terrain” qualities: there are many surfaces on which they work unstable (with a uniform mouse movement, the cursor moves in jerks, and when it stops, it starts to “dance”), and on some (such as transparent glass, mirror, polished wood etc.) the optical sensor refuses to function at all.

Laser instead of LED

An important milestone in the evolution of optical mice was the creation of so-called laser sensors. The first laser sensor designed for use in a mouse was created by employees of Agilent Technologies. If you look at the diagram of its device, shown in Fig. 5, it is easy to notice several fundamental differences from the traditional optical one.

Rice. 5. Scheme of the device of the laser sensor

First, as the name implies, the light source is not an LED, but a semiconductor laser. It works in the infrared range invisible to our eyes (wavelength - 832-852 nm), so there is no usual glow under the body of a working manipulator in this case. Why is a laser better than an LED? The main advantage of the laser is that the light emitted by it is of a coherent nature, which makes it possible to obtain a much more contrasting and detailed image of the surface (Fig. 6). Secondly, the angle of incidence of the beam is significantly (up to about 45°) increased. And thirdly, the optical axis of the video camera lens is located at the same angle at which the light from the source falls on the work surface. Thus, the video camera of the laser sensor reads not the scattered, but the light reflected from the surface.

Rice. 6. On a smooth surface, a conventional optical sensor
reads too fuzzy image (left). The laser sensor allows
get a more contrasting and detailed picture

What has been achieved with these changes? First, provide stable work sensors on smooth surfaces with a very weak microrelief - that is, where optical sensors of a traditional design behave unstably or completely cease to function. Secondly, it was possible to significantly increase the resolution of the sensor (and, accordingly, the accuracy of registration of movements).

Alas, it was not without side effects due to one of design features laser sensor, namely reading the beam reflected from the working surface. From a surface made of a transparent material (glass, plastic, etc.), a very small amount of light that hits it is reflected, and in this case, the intensity luminous flux simply not enough for the sensor to be able to read a sufficiently contrasting image. A similar problem occurs on uneven surfaces, in particular on fabrics with a pronounced texture. When hitting a protrusion or recess, the beam is scattered or reflected at a different angle - in both cases, too little light enters the camera lens.

When working on opaque materials with a polished and glossy surface, the opposite situation occurs: there is too much reflected light and bright glare "blinds" the light-sensitive sensor. Naturally, in both situations, stable operation of the sensor becomes impossible.

The first prototype laser-sensored manipulators designed by Agilent Technologies were presented to the public in early 2004. In September of the same year, Logitech launched the MX-1000 mouse, the world's first mass-produced mouse equipped with a laser sensor.

In mid-2005, Agilent Technologies began shipping pre-engineered motion sensor modules based on LaserStream sensors to all interested manufacturers, and soon laser mice were in the product line of many companies. Some manufacturers (Microsoft in particular) have gone their own way, independently developing laser sensors for their manipulators. Currently, mice with laser sensors are represented in the lines of many companies.

Contrary to the expectations of manufacturers, the appearance of mice with laser sensors did not cause much excitement. This is partly due to the fact that mice with traditional optical sensors have satisfactorily met the needs of most users. In addition, models with laser sensors were significantly more expensive at first, which also did not contribute to their growth in popularity. As a result, laser models attracted the attention mainly of connoisseurs of technical innovations and lovers of dynamic computer games.

Better than laser

In 2006, A4Tech introduced an improved version of the optical sensor, which was called the G-laser (short for Greater than laser - better than laser). Let's pay attention to two distinctive features of such a sensor. Firstly, this is a system of double focusing of the reflected beam, which ensures stable operation of the sensor on glossy and colorful surfaces (A4Tech's know-how). Secondly, not one, but two light sources are used to illuminate the working surface. Similar to a laser sensor, the G-laser sensor reads light reflected from a surface.

In mass-produced manipulators, two variants of the G-laser sensor have become widespread, differing in the type of light source. In one case, these are two LEDs, and in the other, an LED and a semiconductor laser operating in the infrared range. The first version of the G-laser sensor was installed in A4Tech X5 series manipulators (now discontinued), the second one is still used in A4Tech X6 series models (one of them is shown in Fig. 7), as well as in devices from a number of other manufacturers (in in particular, Canyon).

On many types of surface, G-laser sensor manipulators really work much more stable than their laser counterparts, fully justifying the Greater than laser slogan. In particular, this applies to transparent and glossy plastics, as well as to some types of fabrics. However, not all surfaces are subject to mice with a G-laser sensor: they do not work on a mirror and clean transparent glass.

Rice. 7. A4Tech Glaser Mouse X6-90D is one of the mice currently in production,
equipped with a G-laser X6 sensor

An important competitive advantage of models with a G-laser sensor is an affordable price: the cost of junior models is lower compared to analogues equipped with laser sensors.

"Blue-eyed" mice, version of Microsoft

In September 2008, Microsoft introduced the first mass-produced mice equipped with the BlueTrack optical sensor (one of them is shown in Figure 8). As with conventional optical sensors, the light source is an LED. True, not the usual red, but fashionable blue (hence, in fact, the name BlueTrack). Theoretically, this allows you to get a certain advantage, since the wavelength of blue light is about one and a half times shorter than red light (and almost half that of infrared sources). Thus, blue illumination allows the camera to capture finer details of the microrelief of the work surface. However, it should be borne in mind that in this case we are talking about parts with a size of tenths of a micron, and it is difficult to say for sure whether the parameters of the optical path and the photosensitive sensor allow this advantage to be realized in practice.

Rice. 8. Microsoft Explorer Mouse - one of the first manipulators,
equipped with a BlueTrack sensor

There are many skeptics who believe that it was not engineers who insisted on using the blue LED, but marketers. After all, even a technically illiterate user can distinguish the color of the glow under the "belly" of the mouse (of course, if he is not color blind). It remains only to come up with and launch a beautiful myth about the advantages of blue backlighting over red to the masses - fortunately, experienced marketers can easily cope with solving such problems.

But back to technology. The area of ​​the spot, the image of which is read by the camera of the BlueTrack sensor, is 4 times larger compared to the optical sensor of the traditional design. This ensures that much more detail is captured in the camera's "field of view", which in turn makes the sensor more stable on smooth surfaces. BlueTrack also has something in common with a laser sensor: a beam reflected from the working surface enters the camera lens.

One way or another, but the desired result was achieved: mice with a BlueTrack sensor really work on many surfaces that are not subject to manipulators with traditional optical and laser sensors - in particular, on materials with a smooth and glossy finish, on most fabrics, etc.

Currently, BlueTrack sensors are used in a number of wired and wireless mice manufactured by Microsoft, such as the Comfort Mouse 3000/4500/6000, Wireless Mouse 2000/5000, Wireless Mobile Mouse 3500/4000/6000, etc. Despite the relatively wide range of models, such manipulators have not yet become mass-produced. This is partly due to their rather high price: a model with a BlueTrack sensor will cost more than counterparts equipped with an optical or laser sensor.

In the dark field

In August 2009, the Swiss company Logitech announced the Performance Mouse MX and Anywhere Mouse MX wireless mice. The main novelty introduced in these models is a sensor based on Darkfield Laser Tracking technology.

Unlike their counterparts at Microsoft, Logitech's developers chose to build on the design of a laser sensor. A fundamental innovation was the use of dark field microscopy (hence the name of the technology - Darkfield) instead of reading the image reflected from the working surface.

As seen in fig. 9, the optical axis of the video camera lens of this sensor is perpendicular to the plane of the working surface. Since the light source is set at an angle to the surface, the rays from its flat areas are reflected at the same angle and do not enter the camera lens. Thus, the camera captures only those objects that scatter the light falling on them - microscopic scratches, bumps, dust particles, etc. As a result, the sensor reads the image of a kind of "defect map" of the surface, which resembles the appearance of the starry sky (Fig. 10).

Rice. 9. Through the application of the microscopy method
in a dark field, the Darkfield laser sensor is able to work
on smooth and transparent surfaces

Rice. 10. This is what the image looks like,
read by light sensor
Darkfield sensor on a smooth surface,
made of transparent material

In real operating conditions, even on a clean and perfectly smooth (as it seems to us) surface, there are quite a few objects that the sensor camera can “see”. These are microscopic cracks and scratches invisible to the naked eye, dust particles, lint, fingerprints, detergent residues, etc. Thanks to this, the sensor based on Darkfield Laser Tracking technology is able to work even on transparent and smooth surfaces that do not have a pronounced microrelief. This solution ensures stable operation of the manipulator on a wide variety of surfaces, including transparent glass with a thickness of 4 mm or more.

Although more than two years have passed since the debut of Darkfield Laser Tracking, this technology is still the most effective among the solutions used in mass-produced manipulators. However, it also has a significant drawback - the high price of devices. Both models equipped with such sensors are presented in the highest price category- so it would be too optimistic to expect a rush demand for these devices. Especially considering the fact that the announcement of these products took place at the height of the economic crisis.

Currently, only two manipulators equipped with Darkfield Laser Tracking sensors are on sale - Logitech Performance Mouse MX (Fig. 11) and Anywhere Mouse MX.

Rice. 11. Wireless Logitech Performance Mouse MX,
equipped with a sensor based on Darkfield Laser Tracking technology

Strictly vertical

Earlier this year, A4Tech introduced the first production models of manipulators equipped with V-Track Optic 2.0 optical sensors (for readability reasons, we will simply refer to them as V-Track below). As in a conventional optical sensor, the light source in them is a red LED. However, the rest of the design of this sensor has a number of fundamental differences.

The beam is focused into a narrow beam (the area of ​​the hole in the bottom panel of the mouse body is only 5 mm 2) and is directed strictly perpendicular to the plane of the working surface. The V-Track sensor camera reads the reflected beam; the optical axis of its lens is perpendicular to the plane of the working surface (Fig. 12).

Rice. 12. Scheme of operation of the V-Track Optic 2.0 sensor

By focusing the beam on a small area, a high intensity of the light flux is achieved - an order of magnitude higher than with traditional optical sensors. This allows you to get the clearest picture and capture even the smallest details of the surface microrelief. Thanks to this feature, the V-Track sensor works stably on glossy and polished surfaces, where traditional laser and optical sensors fail. In addition, the V-Track sensor performs well on uneven surfaces such as fur, long hair, rough fabrics, etc., where mice with laser sensors are usually extremely unstable.

An additional benefit of the V-Track sensor is its low power consumption (20-30% lower than traditional optical sensor design), which allows for longer battery life wireless manipulators.

Currently, V-Track sensors are used in a range of A4Tech mice, including both wired (N-770FX, N-551FX, OP-530NU, OP-560NU, etc.) and wireless models (G9-500F, G10-770F, G10-810F, etc.). These manipulators are presented in the lower and middle price segments. Prices for lower models with V-Track sensors are quite comparable to the cost of mice of a similar class equipped with traditional optical sensors.

"Blue-eyed" mice, Genius version

Another novelty of this year is the BlueEye Tracking optical sensor. It was developed by engineers from Kye Systems, which is well known to Russian users for a wide range of products manufactured under the Genius trademark.

The design of the BlueEye Tracking sensor is, in fact, an improved version of the traditional optical sensor, but there are a couple of fundamental differences. The first is that a blue LED is used instead of red. The second concerns the modified scheme of the optical path (Fig. 13). An additional lens provides focusing of the light beam, due to which the area of ​​​​the light spot formed by the BlueEye Tracking sensor is smaller than that of a conventional optical sensor.

Rice. 13. Diagram of the device of the BlueEye Tracking sensor

The BlueEye Tracking sensor provides a higher (compared to the traditional optical sensor) accuracy of registering the movements of the manipulator and works stably on most surfaces while consuming less power.

Currently, BlueEye Tracking sensors are used in the Genius Navigator 905, Mini Navigator 900, Traveler 8000/9000, Ergo 9000, and other wireless mice. In addition, the company recently released the DX-220 wired mouse, also equipped with a BlueEye Tracking sensor. All listed models belong to the middle price category. Considering retail prices, mice equipped with laser sensors are their direct competitors.

Conclusion

So, we have considered the features of the device of various types of optical movement registration sensors used in modern manipulators. Over the past three years, manufacturers of these devices have introduced several new solutions at once, which have significant advantages over traditional optical and laser technologies. However, as sales statistics show, when choosing a manipulator, users prefer a conservative approach, still preferring mice equipped with an optical sensor of a traditional design. This can be partly explained by the affordable price of such models, as well as the low requirements for mouse performance by most buyers. It is possible that many simply do not know about the technological innovations already implemented in mass-produced models.

We hope that this publication will be useful to our readers, and the information presented in it will allow them to better navigate the variety of existing technologies. In addition, we recommend reading the article "Mouse Test Drive". In it you will find detailed information about how well manipulators with different types of sensors work on different surfaces.