Patent ID: 6181356
Filing Date: 2001-01-30
Classification: G03G,H04N

Abstract:
A pattern image reader device, comprising:pattern image reader means for irradiating with light a pattern image for measurement use formed on an image carrier body, receiving reflected light from the pattern image for measurement use, and reading the pattern image for measurement use according to an amount of light received;wherein the pattern image reader means includes:a semiconductor laser for irradiating the image carrier body with light;light converging means for converging the light from the semiconductor laser at the pattern image for measurement use;a light receiving element for receiving reflected light from the image carrier body and generating for output an electric signal that changes with an amount of the light received; andpower stabilizer means for maintaining the amount of light generated by the semiconductor laser; andmeasuring means for sampling, every predetermined period of time, the amount of light received that changes with a relative movement of the pattern image reader means and the image carrier body, and obtaining a size or position of the pattern image for measurement use in a direction of the relative movement according to a result of the sampling and a distance covered by the relative movement during the predetermined period of time.