Image pickup device

• US 4,455,574 A
• Filed: 05/12/1982
• Issued: 06/19/1984
• Est. Priority Date: 05/15/1981
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hashimoto, Seiji, Tanaka, Nobuyoshi
• Primary Examiner(s): Martin, John C.
• Assistant Examiner(s): Kostak, Victor R.
• Application Number:
  US06/377,586
• Time in Patent Office: 769 Days
• Field of Search: 358/213, 358/212, 358/221, 357/24 LR
• US Class Current: 348/257
• CPC Class Codes: H04N 25/63 applied to dark current

Abstract

The disclosed image pick-up device is provided with a scanning type image sensing arrangement having an image sensing area and a light-shielded area for obtaining an optical black reference, and control means for changing the scanning speeds between said image sensing area and light-shielded area.

Claims

1. An image pickup device comprising:

(A) an image sensing surface having a first portion for obtaining image signals and a second portion for obtaining an optical black reference;

(B) means for scanning said image sensing surface; and

(C) means for controlling the scanning means to change the scanning speed of said scanning means between said first portion and said second portion.

2. An image pickup device as described in claim 1, wherein said control means is formed to control the speed of scanning so that the speed of scanning of the second portion of said image sensing surface is slower than that of scanning the first portion.

3. An image pickup device as described in claim 2, wherein said second portion of said image sensing surface is located on said image sensing surface to be able to obtain the optical black reference in a horizontal blanking period of a standard television.

4. An image pickup device as described in claim 1, or 2, or 3, further including:

means for clamping at least a part of those of the signals obtained by scanning said image sensing surface by said scanning means which correspond to said second portion to a predetermined level to obtain the optical black reference.

5. An image pickup device as described in claim 4, wherein said image sensing surface has one array of a plurality of photo-electric transducer elements.

6. An image pickup device as described in claim 5, further including:

means positioned in the preceding stage of said clamp means for sampling and holding the signals of the individual photo-electric transducer elements constituting said image sensing surface; and

wherein

said clamp means clamps those of the signals sampled and held by said sample and hold means which correspond to said second portion to the said predetermined level.