Method for driving a linear image sensor

• US 5,483,282 A
• Filed: 07/01/1994
• Issued: 01/09/1996
• Est. Priority Date: 06/18/1992
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Nakanishi, Junji
• Primary Examiner(s): Razavi, Michael T.
• Assistant Examiner(s): CHRISTENSEN, ANDREW BRUCE
• Application Number:
  US08/269,761
• Time in Patent Office: 557 Days
• Field of Search: 348/311, 348/314, 348/317, 348/296, 348/297, 348/220, 377/60, 257/242, 257/243
• US Class Current: 348/311
• CPC Class Codes: H01L 27/14887 Blooming suppression
• CPC Class Codes: H04N 25/53 Control of the integration time
• CPC Class Codes: H04N 25/622 by controlling anti-blooming drains
• CPC Class Codes: H04N 25/701 Line sensors
• CPC Class Codes: H04N 25/713 Transfer or readout registers; Split readout registers or multiple readout registers
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

In a linear sensor, a charge transfer part is disposed between a one-dimensional array of photodetectors and an overflow drain and includes a CCD having four or more transfer gates for each photodetector for transferring signal charges from the photodetector array in a direction of the photodetector array, transfer gates controlling charge transfer from the photodetectors to the CCD, and shutter gates for controlling charge transfer from the charge transfer part to the overflow drain. Each transfer gate is disposed between each photodetector and a prescribed one of the four or more transfer gates, and each shutter gate is disposed between the prescribed transfer gate and the overflow drain. The four or more CCD transfer gates are controlled by four or more phase driving clocks. Therefore, during charge transfer, at least three adjacent CCD transfer gates are all closed so that signal charges are drained from the photodetector into the overflow drain through the transfer gate in the middle of the three transfer gates without mixing the drained signal charges with the signal charges transferred. The charge drain operation is carried out during the charge transfer operation in the charge transfer part whereby the timing of opening the shutter gate can be set at an arbitrary time in the charge read cycle.

Claims

1. A method for driving a linear image sensor in which signal charges from an array of photodetectors are transferred by a charge transfer circuit and drained through said charge transfer circuit comprising:

providing a CCD including at least four CCD transfer gates for each photodetector; and

applying at least four phase driving clocks to said CCD transfer gates for transferring signal charges produced by said photodetectors along said CCD and, while transferring signal charges through CCD transfer gates along said CCD,

turning on (i) a respective charge drain gate disposed between each photodetector and a corresponding one of said CCD transfer gates and (ii) a shutter gate disposed between the corresponding CCD transfer gate and a charge drain circuit while the CCD transfer gates adjacent to and on opposite sides of the corresponding CCD transfer gate are turned off to drain signal charges from each photodetector into said charge drain circuit.