Workings of An optical mouse

 

An optical mouse emits a a bright light onto the surface from a light emitting diode(LED) at the bottom of your mouse (this is where the ball of your typical mouse would be at). The light gets reflected by the surface which is detected by a photoelectric cell also found at the bottom of the cell. This cell has a lens which magnifies the reflected light so the mouse can emulate your hand movements with the cursor on your screen. As you move your mouse a pattern of reflected light is formed which is then translated to cursor movements in a chip in your mouse.

That means that an optical mouse in entirely electronic and with little moving parts. What is it made up of that allows it to do so?(I was very curious about this.)

Above is the inside of an optical mouse and a few main components. What are they?

1. An LED at the back generates red light and shines it horizontally, from the back of the mouse toward the front (from the left to the right of this photo).
2. A plastic light guide channels the light from the LED at an angle, down onto the desk.
3. A light-detector chip measures light reflected back up from the desk, converting the analog movements of your hand into digital signals that can be sent to your computer.
4. The scroll wheel at the front of the mouse is mounted on a switch mechanism that detects both how much it's rotated and whether you've pressed it (it functions like the central button of a conventional mouse). Rotations of the scroll wheel can be detected in a variety of different ways. Some mice use potentiometers (broadly, variable resistors), similar to the volume control on a radio but able to turn around multiple times. Others use various kinds of rotary switches or optical encoders to convert analog wheel movements to digital signals.
5. A microswitch detects when you press the right mouse button. There's an identical switch on the other side to detect the left mouse button.
6. The USB cable connection carries digital information from the mouse to your computer.

One thing the above is an optical mouse with a single LED but it is not uncommon to see optical mouse with two LEDs. It will do/be same as above described but it will use one LED will be used to emit light on the surface which will be caught by the photoelectric cell and the second LED will glow at the back of the mouse to show its working

Bibliography

https://www.explainthatstuff.com/computermouse.html#%3A~%3Atext%3DAn%20optical%20mouse%20works%20in%2Cshort%20distance%20from%20the%20LED

https://www.explainthatstuff.com/diodes.html

https://www.explainthatstuff.com/how-photoelectric-cells-work.html