Do you know how wheels work? Most mouse wheels are related to this little thing. This is a rotary encoder switch, also known as a mechanical encoder. If it is broken, you can't scroll the page.
One end of the drum is inserted into this turntable. When we roll the drum, we drive the turntable to rotate, generating a pulse signal, and the computer relies on this signal to judge the rotating direction and speed of the drum.
It's this little thing. It's simple. There are four parts on the far left, which generally contain manufacturer information, installation height and service life. For example, the manufacturer is curious, the installation height is 10 mm, and the service life is 5 million cycles. Measure the installation height according to the figure on the right.
When the turntable rotates, the scale edge rubs against the elastic sheet, resulting in a sense of paragraph. When we use the wheel, we will have a sense of grid by grid, which comes from the turntable and elastic piece.
The other side of the turntable is inlaid with contact pieces with contacts, and the three contacts are equally divided at an interval of 120 degrees, corresponding to three sectors respectively.
On the far right is the plastic shell base, which is embedded with conductive carbon and measured by multimeter. In fact, it is three parts, which are connected by three pins.
Note that the areas of these three sectors are different. The red one is the largest and the other two are equal.
You can give these areas a number. Red, yellow and blue correspond to the alternating connection and disconnection of the touch pad and the three positions when the turntable rotates, and continuously send out different signals. This signal is processed by the mouse and transmitted to the computer. The computer judges the moving direction of the wheel according to this signal. If the time unit is added, the computer can judge the speed of the wheel. Let's add a contact piece to the turntable. This green three-pointed pointer represents the contact piece.
Take clockwise rotation as an example.
With the rotation, different signal combinations will appear. 002012010201020102 when the computer receives this signal, it will judge that the mouse rotates clockwise in a certain unit of time.
By analogy, if the computer receives signals arranged in reverse, it is that the wheel is rotating counterclockwise.
This is the working principle of mechanical encoder.
The mouse itself is a consumable, so based on cost considerations, most mice in the market use mechanical encoders. Inside the encoder, the life of various frictions between metal and plastic is inherently short. In order to reduce the cost, it is really worse than the worst. Material shrinkage leads to a sharp decline in hand feel and life. These mechanical encoders on the market are marked with 50,000 cycles with short service life and 2 million cycles with long service life. Prices range from a few cents to a few dollars. If it is damaged, in view of the embedded conductive carbon structure, I personally think it has no maintenance value.
Just now I mentioned that most mice use mechanical encoders. What about a small part? This small part refers to the grinding roller.
Look at the bars.
First look at this wheel. There are many squares in the middle of the wheel. These grids are gratings. There are light sources and sensors on both sides of the wheel. When the wheel rotates, it will repeatedly block/transmit light. The chip calculates the moving direction and speed of the wheel according to the flicker of light and shadow.
This is the principle of grating roller.
At the same product level, grating roller is slightly more expensive than mechanical roller. Because the main parts of the grating encoder are non-contact when used, the grating roller with long natural life is afraid of light interference. I don't think I've seen any roller with a ticker.
Speaking of rollers, can there be optical rollers, and micro-motion can also have optical micro-motion?