IMAGE READER AND ITS SIGNAL CORRECTION METHOD

• Main Author: SUZUKI SEISUKE
• Format: Patent
• Language: English
• Published: 30.08.1996
• Edition: 6
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION

PURPOSE: To provide an optical image reader employing a solid-state line sensor in which black level is corrected by a using a lamp of high luminance in the lighting state without providing a mechanical shutter mechanism. CONSTITUTION: The image reader is provided with a black level correction circuit 10 having a light source, a solid-state line sensor 7, and a black level correction line memory 12. The solid-state line sensor 7 is provided with a light receiving section 1, a charge discharging section 4 discharging charges stored in the light receiving element, a shutter gate 5 provided between the light receiving section 1 and the charge discharge section 4, and a CCD charge transfer section 3 transferring charges stored in the light receiving section 1. When the shutter gate 5 is open under the lighting state of the light source, the output of the solid-state image line sensor 7 is stored in advance in the black level correction line memory 12 as black reference level data and the read image data are corrected based on the black reference level data.