Lecture Notes: How Optical Mice Work

Introduction

The lecture discusses the functioning of optical mice, which is the prevalent technology in use today.
Optical mice translate the movement of a user's hand into cursor movement on a screen.

Optical Sensor: A tiny camera inside the mouse that captures images at a high frame rate.
Illuminating Light: Usually an LED that lights up the surface beneath the mouse for the camera to capture.

The camera takes continuous pictures of the illuminated surface and compares each new image to the previous one.
This comparison allows the computer to determine the direction and distance the mouse has moved.
Resolution and Frame Rate:
- High resolution and frame rate are crucial for accuracy and smoothness.
- Typical mice have a frame rate of 2,000 to 6,000 images per second.
- Resolution can range from 1,600 to 4,000 pixels per inch.
Data Handling:
- Images are compared and discarded immediately, thus requiring no storage.
- Initial technology for optical mice was developed by the military.

Simple processing chips in the mouse handle initial calculations.
Information is sent to the computer's CPU, processed in the kernel.
The kernel is a low-level part of the operating system handling essential functions, including mouse input.
Even when programs freeze, mouse movement usually continues, due to the kernel's priority management.

Before optical mice, ball mice were common.
Ball Mice Mechanism:
- Featured a rubber ball for detecting movement across surfaces.
- Movement of the ball turned adjoining wheels to track x and y-axis movements.
Alternative Design:
- Trackball mice, where users roll a large ball, use a similar mechanical system.
- Useful for limited space scenarios.

Encouragement to engage with and share the video if more information is desired.