Charge coupled device with exposure and antiblooming control

• US 3,866,067 A
• Filed: 05/21/1973
• Issued: 02/11/1975
• Est. Priority Date: 05/21/1973
• Status: Expired due to Term

• Current Assignee: Fairchild Weston Systems Inc.
• Original Assignee: Gilbert F. Amelio
• Inventors: Amelio, Gilbert F.
• Primary Examiner(s): Miller, Jr., Stanley D.
• Assistant Examiner(s): Larkins, William D.
• Application Number:
  US05/362,131
• Time in Patent Office: 631 Days
• Field of Search: 317/235G 357/24 307/221D,304,311 250/211J
• US Class Current: 327/514
• CPC Class Codes: H01L 27/14887 Blooming suppression
• CPC Class Codes: H01L 31/1133 the device being a conductor-insulator-semiconductor diode or a CCD device

Abstract

The charge generated in a light sensing element in semiconductor material by incident radiation is transferred to a charge sink by lowering the potential in the semiconductor material between said light sensing element and the charge sink. When it is desired to accumulate charge in the light sensing element for some purpose, the potential in this intermediate region of semiconductor material is raised to prevent the flow of additional charge to the charge sink region. By adjusting the potential on this intermediate region, a given amount of charge can be allowed to accumulate in the light sensing element while at the same time any additional charge can be allowed to transfer to the charge sink region. The charge packet generated in the light sensing element is read out of the light sensing element in the normal manner.

Claims

1. The method of operating a light sensitive element comprising a first region of semiconductor material overlaid by a first electrode, said light sensing element being capable of containing a charge packet and being part of a charge coupled device which comprises:

allowing charge accumulated in the light sensing element to transfer to a charge sink region by lowering the potential in a first intermediate region in the semiconductor material between said light sensing element and the charge sink region;

raising the potential in said first intermediate region of semiconductor material between said light sensing element and said charge sink region to a level selected to allow a given amount of charge to accumulate in said light sensing element and any additional charge formed in said light sensing element to transfer to said charge sink region;

transferring, at the end of a given time, the charge accumulated in said light sensing element to an adjacent region of semiconductor material by lowering the potential of said adjacent region of semiconductor material and the potential of a second intermediate region of semiconductor material between said adjacent region of semiconductor material and the light sensing element to levels beneath the potential of said light sensing element; and

raising the potential of said second intermediate semiconductor material to a potential above the potential of said adjacent region of semiconductor material on the completion of the transfer of the charge accumulated in said light sensing element to said adjacent region of semiconductor material.

2. The method of claim 1 wherein the step of transferring, at the end of a given time, the charge accumulated in said light sensing element comprises raising the potential of said light sensing element and, at the same time, lowering the potentials of said adjacent region of semiconductor material and of a second intermediate region of semiconductor material between said adjacent region of semiconductor material and the light sensing element to levels beneath the potential of said light sensing element.