information regarding optical mouse working principle

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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