Do you know the optical mouse?

In order to overcome the shortcomings of pure mechanical mouse, such as low accuracy and easy wear of mechanical structure, Logitech successfully designed the first optical mechanical mouse in 1983, commonly called "optical mouse". Optical mouse is improved on the basis of pure mechanical mouse, and the positioning accuracy of mouse is improved by introducing optical technology.

Like a mechanical mouse, an optical mouse has a colloidal ball connected to the X axis and the Y axis. The difference is that the optical mouse no longer has a circular decoding wheel, but two grating code disks with grating slits, and light-emitting diodes and photosensitive chips are added. When the mouse moves on the desktop, the rolling ball will drive the two grating code disks of the X and Y rotating shafts to rotate, and the light emitted by the X and Y light emitting diodes will shine on the grating code disks. Because there is a grating gap in the grating code disk, the light emitted by the diode can directly illuminate the probe composed of two photosensitive chips through the grating gap at an appropriate time. If an optical signal is received, the photosensitive chip will generate a "1" signal, and if no optical signal is received, it will be designated as a "0" signal. Next, these signals are sent to a special control chip to generate corresponding coordinate offset and determine the position of the cursor on the screen.

With the help of this principle, the optical mouse greatly surpasses the original mechanical mouse in accuracy, reliability and response sensitivity, and maintains the advantage of low cost. After the launch, it quickly swept the market, and the pure mechanical mouse was quickly replaced. It can be said that the real mouse era began with the optical mouse, and it has not ended yet. Most of the low-grade mice on the market are of this type. However, the photoelectric mouse also has its inherent defects: the ball at the bottom is not resistant to dirt, and after a period of use, the two shafts will be covered with dirt, which will affect the passage of light, and there will be problems such as insensitive movement and cursor occlusion. Therefore, in order to maintain good performance, the optical mouse requires that the ball and rotating shaft must be thoroughly cleaned every once in a while. In a dusty environment, it is even required to clean it every two or three days.

In addition, with the extension of use time, the photoelectric mouse can not maintain its original good working condition, its response sensitivity and positioning accuracy will also decrease, and its durability is not satisfactory.

As the name implies, the photoelectric mouse is a combination of photoelectricity and machinery. On the basis of mechanical mouse, it changes the most worn contact brush and decoding wheel into non-contact LED light path elements. When the ball rolls, the wheels in the X and Y directions drive the code wheel to rotate. Two groups of light emitting diodes and phototransistors are installed on both sides of the code wheel. The light beam emitted by LED sometimes shines on the phototransistor, and sometimes it is blocked, thus producing two groups of pulse sequences with a difference of 90 degrees. The number of pulses represents the displacement of the mouse, and the phase represents the direction in which the mouse moves. Because of the use of non-contact parts, the wear rate is reduced, thus greatly improving the life of the mouse and increasing the accuracy of the mouse. The shape of an optical mouse is no different from that of a mechanical mouse, and it is difficult to distinguish it without opening the mouse shell.