The micro switch in the mouse is a component that is triggered by a metal reed inside. After the button on the mouse is pressed once, the metal reed in the micro switch is triggered once, and sends an electrical signal to the computer, and then again. reset. Under all the buttons on the mouse, there must be a micro switch, so in fact, the micro switch is the button of the mouse, and the function of the button on the mouse shell is only to facilitate the user to press the micro switch.
The working principle of the mouse micro switch is: the external mechanical force acts on the action reed through transmission elements (such as buttons, buttons, pins, levers, rollers, etc.) The moving contact (normally open contact) and the fixed contact (normally closed contact) at the end of the piece are quickly connected or disconnected. When the force on the transmission element is removed, the action reed produces a reverse action force. When the reverse stroke of the transmission element reaches the critical point of the action of the reed, the reverse action is completed instantaneously. The contact distance of the micro switch is very small, and it has the characteristics of short action stroke, small pressing power, and rapid on-off.
The micro switch in the mouse is located on the circuit board under the button. When the button is pressed once, the metal reed in the micro switch triggers once, and sends an electrical signal to the computer, and then resets to complete a click . Since fretting is a purely physical device, each click of it actually causes wear and consumption, which is why some manufacturers use the number of clicks as a mouse life parameter.
Design features of the mouse switch
The biggest technical feature of micro-motion manufacturers in switch design is to prevent loss and prolong its service life. Fretting loss is divided into two types: wear and fatigue. Fretting wear means contact surface wear or material loss; fretting fatigue refers to the generation of fatigue cracks in metals and other materials or the reduction of fatigue life.
Increasing the strength of the contact element surface is the main way to slow down the loss. It increases surface residual compressive stress through various surface treatments, such as physical (laser, ion implantation, etc. to change the surface microstructure hardening technology), chemical (surface hardening technology such as carburizing, nitriding, etc.), mechanical (shot peening, rolling, etc.) ) process to obtain special composition, structure and properties on the surface of the material to improve its wear resistance and fatigue resistance. In addition, there are also ways to strengthen the electrical capabilities of the easily fatigued metal reeds and contacts, such as switching to metal materials such as silver and alloys.
Changes in structural design can also have the effect of slowing down the loss. For example, changing the internal geometry of the component, clamping method, contact size, etc., also changes the pressure distribution and contact mode at the contact surface, which can improve the performance of anti-fretting damage to varying degrees. Another effective measure to slow down the fretting loss is to reduce the coefficient of friction (ie frictional force), which can be achieved by increasing the lubricating medium.
