Analysis and Optimization of the Laser Speckles Produced by Different Light Sources to Design a New Optical Sensor | ||||
The International Conference on Mathematics and Engineering Physics | ||||
Article 13, Volume 3, International Conference on Engineering Mathematics and Physics (ICMEP-3), May 2006, Page 1-12 PDF (1.48 MB) | ||||
Document Type: Original Article | ||||
DOI: 10.21608/icmep.2006.29916 | ||||
View on SCiNiTO | ||||
Authors | ||||
Hatem El-Ghandoor1; Ashraf F. El-Sherif2; Mohamed Darwish2 | ||||
1Faculty of Sciences, Ain Shams University, Cairo, Egypt. | ||||
2Egyptian Armed Forces. | ||||
Abstract | ||||
Abstract The basic elements of the optical computer mouse (OCM) are; a light emitting diode (LED), image acquisition system (IAS) which acquires images via the lens and a digital signal processor (DSP) to implement the algorithm to determine direction and distance of motion. Here, we describe the light speckles produced from different colour LEDs and laser sources to design and implement a new optical computer mouse. The speckle pattern will be used also to determine the responsivity and velocity of the device relative to the surface it slides on it. The most important and critical property of speckles is their average diameter, which is independent of the type of the surface being illuminated by coherent (He-Ne laser and diode laser) or partially coherent light (LEDs). The average diameter of a speckle pattern is function of the diameter of the illuminated area of the pad surface, the distance between the pad surface and the detector, and the wavelength of the used light. In this work, we replaced the OCM light source by a small powerful coloured LEDs and laser sources and studying the resulting coloured speckle patterns to investigate the effect of different wavelengths and the distance between the pad surface and the detector on the speckle diameters which affects the response of the OCM. | ||||
Keywords | ||||
Laser Speckle Photography; LEDs; Optical computer mouse; Digital image processing; Threshold detector | ||||
Statistics Article View: 132 PDF Download: 212 |
||||