An optical mouse uses light instead of a rolling ball to detect movement. It works by focusing light onto a surface, using a sensor to detect changes in light intensity caused by movement. The sensor processes this information and sends signals to the computer corresponding to the direction and distance moved. New technologies like lasers and image sensors have improved optical mice by increasing sensitivity and allowing them to work on any surface.

1. Optical mouse working principle
Anas Ibrahim,Moeen Ghafoor
GIK institue
Dec 12,2014

2. Outline
• History and literary study
• Optical mouse.
• Little glance of optics in ball mouse.
• General optical and laser mouse comparison.
• Electronic Components
• Working principle
• Light scattering and LED
• Optical mouse sensor
• Communication IC
• Scroll mechanism
• Click mechanism
• References
2GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015

3. History and literary study
• Optical mouse was invented in 1980.
• It didn't gained public attention but in 1998
• First wander was Sun micro systems.[5]
• MAX1000 laser mouse entered into market in
2004 by Avogo and Agilient technology.
• VCSEL technology introduced to reduce size.
• Dark field laser sensor introduced in 2009
3GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015

4. Optical mouse
• It is device which is used to measure the
motion and acceleration of pointer.
• It uses light source instead of ball to judge the
motion of the pointer.
• Optical mouse has sub type called laser mouse
but they share same working principle.
4GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015

5. Little glance of optics in ball mouse
• Ball mouse also posses
led for measuring the
revolution.
• Led light is intercepted
by the wheel.
• Photo detector records
interception and send the signal to processor
5GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015

6. General optical and laser mouse
comparison
General optical mouse
• Optical mouse uses red,
blue green led.
• Optical mouse have three
buttons.
• Optical mouse is less
sensitive.(units DPI)
• Sensitive towards surface.
• Short battery life
Laser mouse
• Laser mouse uses only
infrared led.
• Laser mouse has as many as
12 buttons and can be
programmed by user.
• Highly sensitive.
• Able to work on any hard
surface
• Low battery life
6GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015

7. Electronic Components
1. Led source
2. Lens
3. Mounted camera
4. Scroll mechanism
5. Micro switching
6. USB
7GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015

8. Working principle
• Light is focused on the lens.
• It diverged and come to surface after
deflection from two palates.
• Photo detector can is used to pick the change
in intensity of light at different position.
• Signal is processed and is transferred to the
computer.
8GIK institute Anas Ibarhim,Moeen
Ghafoor
2/11/2015
Schematic of reflection[2]

9. Light scattering and LED
• Lens is used to focus the light.
• Led is used which emitter the light
• This can be IR or visible LED
9GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015
Above lens and led on left
Engineering garage.com
Engineering garage.com

10. Light scattering and LED(cont’d)
• Laser of very small power is
used.
• IR laser is used IR laser
mouse[2]
10GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015
Bottom side of laser mouse
Engineering garage.com
Engineering garage.com

11. Optical mouse sensor
• IC shown in the figure works
on the navigation technology
• IC above is DSP chip which
acquits image and process it.
• In this way it determines the
direction and distance.
• Photodiode/camera is CMOS
sensor uses house lens to
capture 1500-6000 images[4].
11GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015
Camera embedded chip

12. Communication IC
• This IC uses I2C protocol
for interfacing[2]
• USB transceiver IC
• It works as voltage
regulator[3]
12GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015
Communication IC
Engineering garage.com

13. Communication IC(cont’d)
• Communication IC composed of Digital image
processing algorithms
• Can do processing at the rate 18MIPS.
• Above pattern move to south east on opposite
motion of mouse.
13GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015
DIP schematic
Engineering garage.com

14. Scroll mechanism
• When the wheel is rotated
the potentiometer also
rotate.
• Change in the resistance
corresponds to the revolutions
14GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015
Scroll mechanism
Engineering garage.com
Engineering garage.com

15. Click mechanism
• Red part is used for clicking
purpose.
• When a button is clicked,
a flexible metal plate is
pressed which shorts the
two points of the circuit that
detects the mouse click.
15GIK institute Anas Ibarhim,Moeen Ghafoor2/11/2015
Engineering garage.com
Engineering garage.com

16. Conclusion and future
• New emerging technologies are being utilized
in the working mechanism of optical mouse
and to make its use easy and comfortable.
• We can expect its prices and size will be
reduced in future for new ways of circuit
design.
2/11/2015
GIK institute Anas Ibarhim,Moeen
Ghafoor
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17. Reference
1. en.wikipedia.org/wiki/Vertical-cavity_surface-
emitting_laser
2. explainthatstuff.com/computermouse.html
3. thescienceera.wordpress.com/2014/08/13/optic
al-mouse-work/
4. engineersgarage.com/insight/how-optical-
mouse-works?page=1-8
5. engineersgarage.com/contribution/difference-
between-optical-mouse-and-laser-mouse
2/11/2015
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Ghafoor
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18. Questions
2/11/2015
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Ghafoor
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