How is a mouse built inside? - briefly
A mouse’s interior comprises a vertebral column and rib cage supporting muscles, skin, and fur, while the thoracic cavity houses a heart, lungs, and major blood vessels. The abdominal region contains the liver, kidneys, digestive tract, and a brain encased within a skull.
How is a mouse built inside? - in detail
A computer mouse consists of a housing, a motion‑sensing module, a button assembly, a scroll mechanism, a printed‑circuit board (PCB), a power source, and a connection interface.
The outer shell is molded from durable plastic, split into two halves that snap together around the internal components. Inside, the PCB carries the microcontroller, which interprets signals from the sensors and sends them to the host computer. The microcontroller is soldered to surface‑mount devices: voltage regulators, resistors, capacitors, and the USB or wireless transceiver.
Motion detection relies on either an optical sensor or a laser diode paired with a tiny image sensor. Light emitted by the diode reflects off the surface; the sensor captures successive images and the microcontroller calculates displacement by comparing pixel patterns. Some models use a mechanical ball and two orthogonal rollers, where the ball’s rotation is translated into electrical pulses via encoders.
The button assembly features metal or polymer contacts beneath each click area. When pressed, a conductive pad bridges the contact, creating a low‑resistance path that the microcontroller registers as a click event. The scroll wheel incorporates a rotary encoder; each notch produces a digital pulse that the controller interprets as scroll increments.
Power is supplied by a rechargeable lithium‑ion cell in wireless devices or by the host’s USB voltage in wired versions. A voltage regulator ensures a stable 3.3 V for the logic circuits. The connection interface consists of a USB Type‑C or micro‑USB connector, or a radio‑frequency module (e.g., Bluetooth) with an antenna embedded in the housing.
Assembly proceeds as follows:
- Populate the PCB with components using automated pick‑and‑place machines.
- Attach the motion sensor and optical lens assembly to the board.
- Mount the button contacts and scroll encoder onto the PCB.
- Install the power source and connect it to the regulator circuit.
- Place the assembled board inside the plastic shell.
- Snap the two shell halves together, securing the unit with clips or screws.
- Perform functional testing, then package for distribution.