Image sensing method and apparatus in which the exposure time may be varied

• US 5,194,957 A
• Filed: 10/28/1991
• Issued: 03/16/1993
• Est. Priority Date: 11/02/1990
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kyuma, Kenji
• Primary Examiner(s): Razavi, Michael T.
• Assistant Examiner(s): Greening, Wendy R.
• Application Number:
  US07/783,214
• Time in Patent Office: 505 Days
• Field of Search: 358/213.19, 358/213.13, 358/228
• US Class Current: 348/296
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H04N 25/53 Control of the integration time
• CPC Class Codes: H04N 25/71 Charge-coupled device [CCD] sensors; Charge-transfer registers specially adapted for CCD sensors
• CPC Class Codes: H04N 25/73 using interline transfer [IT]

Abstract

Apparatus for controlling a sensing element, such as a CCD, which receives a light signal, performs a photoelectric conversion, and stores information. Information is read from the sensing element, while information which corresponds to a partial interval T1 of a reading interval period nT is eliminated, at the reading period nT, which is n (where n is an integer equal to or greater than 2) times a field period T of a standard television signal.

Claims

1. An image sensing unit comprising:

sensing means for receiving a light signal, performing a photoelectric conversion, and storing information;

reading means for reading the information from said sensing means once each reading period nT (wherein n is an integer equal to or greater than 2 and T is a field period of a standard television signal);

eliminating means for eliminating information from the sensing means, the eliminated information corresponding to a partial interval T1 within the reading period nT; and

altering means for altering the width of the partial interval T1.

2. The unit according to claim 1, wherein a position at which the partial interval T1 begins substantially coincides with a position at which the reading period nT begins.

3. The unit according to claim 1, wherein the length of the partial interval T1 is altered by said altering means in such a manner that an information storage time (nT-T1) of said sensing means in one reading period nT substantially equals an exposure time.

4. The unit according to claim 1, wherein said eliminating means eliminates the information from said sensing means during a horizontal retrace interval of the standard television signal.

5. The unit according to claim 4, wherein the information in said sensing means is eliminated during substantially every horizontal retrace interval in the partial interval T1.

6. The unit according to claim 1, wherein said eliminating means eliminates the information from said sensing means substantially at the start or end of a horizontal retrace interval of the television signal.

7. The unit according to claim 6, wherein the information in said sensing means is eliminated at substantially every horizontal retrace interval in the partial interval T1.

8. An apparatus for controlling a solid-state image sensor, comprising:

reading control means for controlling the solid-state image sensor in such a manner that information is outputted from the solid-state image sensor once every reading period nT (where n is an integer equal to or greater than 2 and T is a field period of a standard television signal);

elimination control means for controlling the solid-state image sensor so as to eliminate information which corresponds to a partial interval T1 within the reading period nT; and

alteration control means for controlling the solid-state image sensor so as to alter the width of the partial interval T1.

9. The apparatus according to claim 8, wherein a position at which the partial interval T1 begins substantially coincides with a position at which the reading period nT begins.

10. The apparatus according to claim 8, wherein the length of the partial interval T1 is altered by said alteration control means in such a manner that an information storage time (nT-T1) in one reading period nT substantially equals exposure time.

11. The apparatus according to claim 8, wherein said elimination control means controls the solid-state image sensor in such a manner that the information from the solid-state image sensor is eliminated during a horizontal retrace interval of the standard television signal.

12. The apparatus according to claim 11, wherein the information in said solid-state image sensor is eliminated during substantially every horizontal retrace interval in the partial interval T1.

13. The apparatus according to claim 8, wherein said elimination control means controls the solid-state image sensor in such a manner that the information in said solid-state image sensor is eliminated substantially the start or end of a horizontal retrace interval of the television signal.

14. The apparatus according to claim 13, wherein the information in said solid-state image sensor is eliminated at substantially every horizontal retrace interval in the partial interval T1.

15. A camera comprising:

sensing means for receiving a light signal, performing a photoelectric conversion, and storing information;

reading means for reading the information from said sensing means once each reading period nT (wherein n is an integer equal to or greater than 2 and T is a field period of a standard television signal);

eliminating means for eliminating information from said sensing means, the eliminated information corresponding to a partial interval T1 within the reading period nT;

altering means for altering the width of the partial interval T1; and

converting means for converting the information read out of said sensing means into a standard television signal.

16. The camera according to claim 15, wherein a position at which the partial interval T1 begins substantially coincides with a position at which the reading period nT begins.

17. The camera according to claim 15, wherein the length of the partial interval T1 is altered by said altering means in such a manner that an information storage time (nT-T1) of said sensing means in one reading period nT substantially equals an exposure time.

18. The camera according to claim 15, wherein said eliminating means eliminates the information from said sensing means during a horizontal retrace interval of the standard television signal.

19. The camera according to claim 18, wherein the information in said sensing means is eliminated during substantially every horizontal retrace interval in the partial interval T1.

20. The camera according to claim 15, wherein said eliminating means eliminates the information from said sensing means at substantially the start or end of a horizontal retrace interval of the television signal.

21. The camera according to claim 20, wherein the information in said sensing means is eliminated at substantially every horizontal retrace interval in the partial interval T1.

22. A method of controlling a solid-state image sensor which performs a photoelectric conversion and stores information, comprising the steps of:

reading information (which information is stored in a sensor portion of said image sensor) once each reading period nT (where n is an integer equal to or greater than 2 and T is a field period of a standard television signal);

eliminating information for a partial interval T1 within the reading interval nT;

altering the width of the partial interval T1;

storing information in said image sensor only for an information storage time (nT-T1) which lasts from immediately after the end of the partial period T1 until the end of the reading period nT; and

reading information from said sensor portion.

23. The method according to claim 22, wherein a position at which the partial interval T1 begins substantially coincides with a position at which the reading period nT begins.

24. The method according to claim 22, wherein the length of the partial interval T1 is altered in such a manner that an information storage time (nT-T1) of said sensor portion in one reading period nT substantially equals exposure time.

25. The method according to claim 22, wherein the information in said sensor portion is eliminated during a horizontal retrace interval of the standard television signal.

26. The method according to claim 25, wherein the information in said sensor portion is eliminated during substantially every horizontal retrace interval in the partial interval T1.

27. The method according to claim 22, wherein the information in said sensor portion is eliminated at substantially the start or end of a horizontal retrace interval of the television signal.

28. The method according to claim 27, wherein the information in said sensor portion is eliminated at substantially every horizontal retrace interval in the partial interval T1.