Mouse Working

8/6/2019 Mouse Working

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Mouse



� The main goal of any mouse is to translate the

motion of your hand into signals that the

computer can use.



� A mouse is a pointing device.

� Physically, a mouse consists of an object heldunder one of the user's hands, with one or more

buttons.� It sometimes features other elements, such as

"wheels", which allow the user to performvarious system-dependent operations, or extrabuttons or features that can add more control.

� The mouse's motion typically translates into themotion of a cursor on a display, which allows forfine control of a graphical user interface.



A computer mouse with the most common standard features:

two buttons and a scroll wheel, which can also act as a third

button



Mechanical mouse

� The mechanical mouse has a single ball that could rotate inany direction.

� The ball mouse has two freely rotating rollers.

� They are located 90 degrees apart.

� One roller detects the forwardbackward motion of themouse and other the leftright motion.

� Opposite the two rollers is a third one (white, in the photo,at 45 degrees) that is spring-loaded to push the ball againstthe other two rollers.

� Each roller is on the same shaft as an encoder wheel thathas slotted edges;

� the slots interrupt infrared light beams to generateelectrical pulses that represent wheel movement.



� The rollers each connect to a shaft, and the shaftspins a disk with holes in it. When a roller rolls,its shaft and disk spin.

� On either side of the disk there is an infrared LEDand an infrared sensor.

� The holes in the disk break the beam of lightcoming from the LED so that the infrared sensor

sees pulses of light.

� The rate of the pulsing is directly related to thespeed of the mouse and the distance it travels.



� An on-board processor chip reads the pulses

from the infrared sensors and turns them into

binary data that the computer can

understand. The chip sends the binary data to

the computer through the mouse's cord.



� In this optomechanical arrangement, the disk

moves mechanically, and an optical system

counts pulses of light. On this mouse, the ball

is 21 mm in diameter. The roller is 7 mm in

diameter. The encoding disk has 36 holes. So if

the mouse moves 25.4 mm (1 inch), the

encoder chip detects 41 pulses of light.





� 1. moving the mouse turns the ball.

� 2. X and Y rollers grip the ball and transfer

movement� 3. Optical encoding disks include light holes.

� 4. Infrared LEDs shine through the disks.

�5. Sensors gather light pulses to convert to Xand Y vectors.





Optical mice

� An optical mouse uses a light-emitting diode

and photodiodes to detect movement relative

to the underlying surface, rather than internal

moving parts as does a mechanical mouse.



� Developed by Agilent Technologies and

introduced to the world in late 1999, the

optical mouse- actually uses a tiny camera to

take thousands of pictures every second.



Here's how the sensor and other parts

of an optical mouse work together:� The CMOS sensor sends each image to a digital signal

processor (DSP) for analysis.

� The DSP detects patterns in the images and examines howthe patterns have moved since the previous image.

� Based on the change in patterns over a sequence of images, the DSP determines how far the mouse has movedand sends the corresponding coordinates to the computer.

� The computer moves the cursor on the screen based onthe coordinates received from the mouse. This happens

hundreds of times each second, making the cursor appearto move very smoothly.





Optical mice have several benefits over

track-ball mice:

� No moving parts means less wear and a lower

chance of failure.

� There's no way for dirt to get inside t

he mouseand interfere with the tracking sensors.

� They don't require a special surface, such as a

mouse pad.



� After the mouse is connected to your computer, itcommunicates with your system through the use of adevice driver, which can be loaded explicitly or builtinto the operating system software. For example, noseparate drivers are necessary to use a mouse with Windows or OS/2, but using the mouse with most DOS-based programs requires a separate driver to be loadedfrom the CONFIG.SYS or AUTOEXEC.BAT file. Regardless

of whether it is built in, the driver translates theelectrical signals sent from the mouse into positionalinformation and indicates the status of the buttons.



� ADDITIONAL READING

IS STRONGLY RECOMMENDED

Date post:	08-Apr-2018
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Mouse Working

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