Working principle of photovoltaic mouse

The biggest difference between a photoelectric mouse and a mechanical mouse is that the positioning method is different. What is the working principle of the photoelectric mouse: There is a light emitting diode inside the mouse, the light emitted by the light emitting diode, illuminating the bottom surface of the mouse (this is why the bottom of the mouse will always emit light ). Then, a part of the light reflected at the bottom of the Optical Mouse is transmitted to an optical sensor (microphoto) through a set of optical lenses for imaging. In this way, when the Optical Mouse moves, its moving track will be recorded as a set of high-speed consistent images. Finally, a dedicated image analysis chip (DSP, or digital microprocessor) inside the Optical Mouse is used to analyze and process a series of images on the mobile track, by analyzing the changes in the positions of feature points on these images, you can determine the moving direction and distance of the mouse to complete the cursor positioning. The Optical Mouse is usually composed of the following parts: optical sensor, optical lens, light emitting diode, interface microprocessor, touch button, roller, line, PS/2 or USB interface, Shell, etc. The following is an introduction: Optical Sensor optical sensor is the core of the Optical Mouse. Currently, only CERNET, Microsoft, and Logitech optical sensor manufacturers can produce optical sensors. Among them, anjet's optical sensors are widely used. Apart from Microsoft's all and part of Logitech's Optical Mouse, other Optical Mouse basically uses anjet's optical sensors. The control chip of the Optical Mouse is responsible for coordinating the work of various components in the optical mouse, communicating (bridging) with external circuits, and transmitting and receiving various signals. We can understand it as a "manager" in the photoelectric mouse ". There is a very important concept that everyone should know, that is, the impact of DPI on mouse positioning. DPI is used to measure the number of points that can be detected by moving the mouse every 1 inch. The smaller the DPI, the fewer points that can be located, and the lower the positioning precision. The larger the DPI, when multiple points are located, the positioning accuracy is high. In general, the scanning accuracy of traditional mechanical mouse is below 400 dpi, while that of photocells can reach 800 or even DPI, this is why the positioning accuracy of the Optical Mouse can easily exceed the mechanical mouse. The optical lens component of the optical lens component is placed at the bottom of the Optical Mouse. From Figure 5, we can clearly see that the optical lens component consists of a prism and a circular lens. The prism is responsible for transmitting the light emitted by the light emitting diode to the bottom of the mouse and illuminating it. A circular lens is equivalent to a camera lens, which is responsible for transmitting the illuminated image at the bottom of the mouse to a small hole at the bottom of the optical sensor. By watching the back shell of the photocell mouse, we can see that the circular lens is very similar to a camera. Through the experiment, the author concludes that no matter whether it is to block the prism or the optical path of the circular lens, will immediately cause the Optical Mouse to be "blind ". The result is that the optical mouse cannot be located, which shows the importance of the optical lens component. Light Emitting Diode optical sensors need continuous "camera" at the bottom of the mouse without light, and naturally the support of "camera lights" is indispensable. Otherwise, the image taken from the bottom of the mouse will be dark, dark images cannot be compared, and of course optical positioning cannot be performed. Generally, the light emitting diode used by the optical mouse (7) is red (and some are blue) and highlighted (in order to obtain sufficient illumination ). The red light emitted by the light emitting diode is partially illuminated by the optical lens at the bottom of the mouse (that is, the prism in it), and the other is directly transmitted to the front of the optical sensor. In a word, the role of the light emitting diode is to generate the light source required for the operation of the Optical Mouse. The mouse without buttons on the touch button is unimaginable, so there will be at least two touch buttons on the ordinary photoelectric mouse. Three touch buttons are soldered on the PCB of the founder lighting mouse (figure 8 ). In addition to the left and right buttons, the middle buttons are assigned to the scroll wheel. The advanced mouse usually has two scroll wheels X and Y, while most of the Optical Mouse is just like the founder photoelectric mouse, with only one scroll wheel. When you scroll up or down the scroll wheel, the "document" or "webpage" that you are viewing will scroll up or down. When the scroll wheel is pressed, the "middle" on the PCB will be used. Note: The actions generated by the "middle" can be defined by the user according to their own needs. When we unload the scroll wheel, we can see that there is a pair of photoelectric "transmitting/receiving" device on the scroll wheel position. The "scroll wheel" carries a grid. Because the grid can intercept the optical path of the photoelectric "transmitting/receiving" device, a paging pulse signal can be generated, this pulse signal is sent to the Windows operating system through the control chip, and thus page Flip can be generated. In addition to the above, what does the Optical Mouse include? It also includes connection lines, PS/2, USB interfaces, and casings. Since there are not many differences between these parts and the mechanical mouse, we will not describe them here!