Editing Optical mouse (section)

=== Optical sensor ===
[[File:ST_Microelectronics_OSMLT04_H_mouse_sensor_chip_with_vertical_and_horizontal_illumination.jpg|thumb|Microscope photograph of the IntelliMouse Explorer [[sensor]] silicon [[Die (integrated circuit)|die]]]]
[[File:Opto mouse sensor.jpg|thumb|The optical sensor from a Microsoft Wireless IntelliMouse Explorer (v. 1.0A)]]

Modern surface-independent optical mice work by using an [[optoelectronic]] [[sensor]] (essentially, a tiny low-resolution video camera) to take successive images of the surface on which the mouse operates.  As computing power grew cheaper, it became possible to embed more powerful special-purpose [[image processing|image-processing]] [[integrated circuit|chips]] in the mouse itself. This advance enabled the mouse to detect relative motion on a wide variety of surfaces, translating the movement of the mouse into the movement of the cursor and eliminating the need for a special mouse-pad. A surface-independent coherent light optical mouse design was patented by Stephen B. Jackson at Xerox in 1988.<ref>{{cite patent |country=US |number=4794384 |status=patent}}</ref>

Xerox's inventions were never massively commercially exploited, however, and optical mice would remain elusive in the personal computer market until [[Microsoft]] released the [[IntelliMouse]] with IntelliEye and IntelliMouse Explorer in 1999.<ref name="aiecv" /><ref>{{Cite web |date=1999-04-19 |title=Microsoft Press Release, April 19th 1999 |url=http://www.microsoft.com/presspass/press/1999/apr99/eyepr.mspx |url-status=dead |archive-url=https://web.archive.org/web/20111128233939/http://www.microsoft.com/presspass/press/1999/apr99/eyepr.mspx |archive-date=2011-11-28 |access-date=2011-05-11 |publisher=Microsoft}}</ref> These mice used technology developed by Hewlett-Packard under their [[Agilent Technologies]] subsidiary (see [[#Principle of operation|below]]). These mice worked on almost any surface, and represented a welcome improvement over mechanical mice, which would pick up dirt, track capriciously, invite rough handling, and need to be taken apart and cleaned frequently. Other manufacturers soon followed Microsoft's lead, including Apple for their [[Apple Pro Mouse|Pro Mouse]],<ref name="aiecv">{{Cite book |last=Lyon |first=R.&nbsp;L. |chapter-url=https://books.google.com/books?id=p_GbBQAAQBAJ&dq=%22hewlett+packard%22+%22intellimouse%22+%22agilent%22+%22optical+mouse%22&pg=PA20 |title=Advances in Embedded Computer Vision |date=2014 |publisher=Springer |isbn=9783319093871 |editor-last=Kisačanin |editor-first=Branislav |page=20 |chapter=The Optical Mouse: Early Biomimetic Embedded Vision |editor-last2=Margrit Gelautz |via=Google Books}}</ref> using components manufactured by Agilent (once they spun off from HP), and over the next several years mechanical mice became obsolete.
[[File:S5085 optical mouse IC.jpg|thumb|'''S5085''' optical sensor IC die (CMOS sensor + driver)]]
The technology underlying the modern optical computer mouse is known as [[digital image correlation]], a technology pioneered by the defense industry for tracking military targets.  A simple binary-image version of digital image correlation was used in the 1980 Lyon optical mouse.  Optical mice use image sensors to image naturally occurring texture in materials such as wood, cloth, mouse pads and [[Formica (plastic)|Formica]].  These surfaces, when lit at a grazing angle by a light emitting diode, cast distinct shadows that resemble a hilly terrain lit at sunset.  Images of these surfaces are captured in continuous succession and compared with each other to determine how far the mouse has moved.