Image processing apparatus

• US 20030025065A1
• Filed: 07/16/2002
• Published: 02/06/2003
• Est. Priority Date: 07/18/2001
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hashimoto, Seiji
• Granted Patent: US 6,952,002 B2
• Time in Patent Office: Days
• US Class Current: 250/205
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

An image processing apparatus is provided which includes: a sensor unit having a plurality of photoelectric conversion portions for converting light from an object into charges and accumulating the charges; a sensor drive circuit for controlling an accumulation time of the charges in the sensor unit; a light source for irradiating light on the object; a temperature detection circuit for detecting ambient temperature of the sensor unit; and a control circuit for controlling the sensor drive circuit and the light source according to an output of the temperature detection circuit.

Claims

1. An image processing apparatus comprising:

a sensor unit having a plurality of photoelectric conversion portions for converting light from an object into charges and accumulating the charges;

a sensor drive circuit arranged to control an accumulation time of the charges in said sensor unit;

a light source for irradiating light on the object;

a temperature detection circuit arranged to detect ambient temperature of said sensor unit; and

a control circuit arranged to control said sensor drive circuit and said light source according to an output of said temperature detection circuit.

2. An image processing apparatus according to claim 1,

wherein said control circuit has a first mode for performing a control to shorten the accumulation time of the charges in said sensor unit and intensify light from said light source if the ambient temperature is higher than a predetermined temperature and a second mode for performing a control to extend the accumulation time of the charges in said sensor unit and weaken light from said light source if the ambient temperature is lower than the predetermined temperature.

3. An image processing apparatus according to claim 1,

wherein said control circuit has a first mode for performing a control to shorten the accumulation time of the charges in said sensor unit and turn on said light source if the ambient temperature is higher than a predetermined temperature and a second mode for performing a control to extend the accumulation time of the charges in said sensor unit and turn off said light source if the ambient temperature is lower than the predetermined temperature.

4. An image processing apparatus according to claim 1,

wherein the object is a fingerprint, and said apparatus further comprising an image recognition circuit arranged to determining whether or not finger print information registered in advance and fingerprint information from said sensor unit matches with each other.

5. An image processing apparatus according to claim 4,

wherein said image processing apparatus is a portable terminal that can communicate with other portable terminals when a user of the portable terminal inputs a predetermined number.