Image pick-up apparatus having an exposure control device

• US 4,734,777 A
• Filed: 06/01/1987
• Issued: 03/29/1988
• Est. Priority Date: 12/07/1982
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sakai, Shinji, Okino, Tadashi
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/057,716
• Time in Patent Office: 302 Days
• Field of Search: 358/228, 358/213.19, 358/213.13, 354/270, 352/141
• US Class Current: 348/221.1
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls

Abstract

In an image pick-up apparatus, an image pick-up arrangement converts an object image into electrical signals, a light metering portion other than the image pick-up arrangement detects the brightness of the object image, and a diaphragm regulates the amount of light reaching the image pick-up arrangement. A control controls the aperture value of the diaphragm in response to the output of the image pick-up arrangement and the output of the light metering portion.

Claims

1. An image pick-up apparatus, comprising:

image pick-up means for converting an object image into an electrical signal;

light metering means other than said image pick-up means for detecting a brightness of the object image; and

exposure control means for controlling an exposure condition of said image pick-up means in response to a sequential output of said light metering means and said image pick-up means.

2. An image pick-up apparatus according to claim 1, wherein the exposure control means controls the exposure condition with the output of the light metering means, then thereafter controls said exposure condition with the output of the image pick-up means.

3. An image pick-up apparatus according to claim 1, wherein the exposure control means has memory means for memorizing a light metering value obtained by the light metering means and controls the exposure condition based on a memorized value by said memory means and the image pick-up output of the image pick-up means.

4. An image pick-up apparatus according to claim 3, further comprising second memory means for memorizing the exposure condition being controlled by the exposure control means.

5. An image pick-up apparatus according to claim 1, which further comprises selection means for selecting a still photo-taking mode and a moving photo-taking mode, wherein when the still photo-taking mode is selected the exposure control means controls the exposure condition by the light metering output of the light metering means, and when the moving photo-taking mode is selected, the exposure control means controls the exposure condition by at least the light metering output of the image pick-up means.

6. An image pick-up apparatus according to claim 3, further comprising an optical view finder.

50. An apparatus according to claim 1, 7 or 12, wherein said exposure condition includes a period for a converting operation of said image pick-up means.

7. An image pick-up apparatus, comprising:

image pick-up means for converting an object image into electrical signals;

light metering means other than said image pick-up means for detecting a brightness of the object image;

instructing means for instructing the image pick-up means to pick up an image; and

control means for controlling an exposure condition of said image pick-up means with an output of the light metering means and then controlling the exposure condition with an output of the image pick-up means based on the instructions from the instructing means.

8. An image pick-up apparatus according to claim 7, wherein the image pick-up means includes a solid image pick-up element, and the control means controls the exposure condition by an output of the image pick-up means after unnecessary electric charge within the solid image pick-up element has been cleared.

9. An image pick-up apparatus according to claim 7, wherein said control means comprises shutter means for blocking light from an object from being irradiated onto the image pick-up means.

10. An image pick-up apparatus according to claim 9, wherein the shutter means comprises a rotary shutter and a driving motor.

11. An image pick-up apparatus according to claim 10, further comprising phase detection means for detecting a rotating phase of the rotary shutter, wherein the control means controls the exposure condition by an output of the image pick-up means after the phase detection means detects that the rotating phase has been stabilized.

12. An image pick-up apparatus, comprising:

image pick-up means for converting an object image into an electrical signal;

light metering means provided separately from the image pick-up means for metering light from the object;

memory means for memorizing information sensed by the light metering means; and

control means for controlling an exposure condition based on said information memorized by the memory means and the electrical signals obtained from the image pick-up means.

13. An image pick-up apparatus according to claim 12, further comprising a reflection member provided on an optical path from the object to the image pick-up means and an optical view finder to visually recognize the object through said reflection member.

14. An image pick-up apparatus according to claim 13, further comprising diaphragm means between the reflection member and the object, and the light metering means detects intensity of object light coming through the diaphragm means.

15. An image pick-up apparatus according to claim 14, wherein the light metering means makes light metering when the diaphragm means is maintained at a fully opened state, and the memory means memorizes the light metering value of that time.

16. An image pick-up apparatus according to claim 15, wherein the control means controls driving of the diaphragm means with the light metering value memorized in the memory means, then thereafter controls the exposure condition by an output of the image pick-up means.

17. An image pick-up apparatus according to claim 16, wherein the control means returns the diaphragm means to a fully opened state after outputs of the image pick-up means are recorded.

18. An image pick-up apparatus, comprising:

image pick-up means for converting an object image into an electrical signal;

exposure means for limiting an amount of light incident into said image pick-up means;

light metering means provided separately from the image pick-up means for metering light from an object;

exposure control means for controlling the exposure means based on the light metering information sensed by the light metering means and the electrical signals obtained from the image pick-up means; and

memory means for memorizing an exposure information of the exposure means controlled by said diaphragm control means.

19. An image pick-up apparatus according to claim 18, further comprising photo-taking instructions means for giving an instruction to take a photo, and memorizing instruction means for giving an instruction to the memory means to operate before said instruction to take a photo.

20. An image pick-up apparatus according to claim 19, wherein the diaphragm control means sets the diaphragm means at the exposure information memorized within the memory means at the time an instruction is issued by the photo-taking instruction means.

21. An image pick-up apparatus according to claim 20, further comprising a reflection member provided on an optical path from the object to the image pick-up means, and an optical view finder to visually recognize said object through said reflection member.

22. An image pick-up apparatus according to claim 21, wherein the exposure means is provided between the reflection member and the object, and the light metering means detects intensity of object light passing through the exposure means.

23. An image pick-up apparatus according to claim 22, wherein the light metering means makes a light metering when the exposure means is maintained at a fully opened state.

51. An apparatus according to claim 18 or 24, wherein said exposure means includes means for controlling a period for a converting operation of said image pick-up means.

24. An image pick-up apparatus, comprising:

image pick-up means for converting an object image into an electrical signal;

exposure means for limiting an amount of light incident into said image pick-up means;

light metering means having faster responsive characteristic than that of the image pick-up means and for metering light from the object; and

control means for effecting the light metering by the light metering means in case that a still picture is picked up by the image pick-up means and effecting the light metering based on at least an output of the image pick-up means in case that a moving picture is picked up by the image pick-up means.

25. An image pick-up apparatus according to claim 24, further comprising selection means for selecting a photo-taking mode for a still picture and a photo-taking mode for a moving picture.

26. An image pick-up apparatus, comprising:

(a) an image sensor for converting an image of an object into an electrical signal;

(b) light receiving means for detecting the light of the object, said light receiving means having a characteristic different from that of the image sensor; and

(c) exposure control means for controlling an exposure condition of said image sensor in correspondence to a sequential output of said light receiving means and said image sensor.

27. An image pick-up apparatus according to claim 26, wherein said exposure control means includes a diaphragm.

28. An image pick-up apparatus according to claim 26, which further comprises change-over means for selectively applying outputs of said light receiving means and said image sensor to the exposure control means.

29. An image pick-up apparatus according to claim 28, wherein said change-over means performs change-over operations along with the initiation of an image pick-up operation by said image sensor.

30. An image pick-up apparatus according to claim 29, wherein said change-over means changes the signal applied to said exposure control means from the output of said light receiving means to the output of said image sensor along with the initiation of the image pick-up operation by said image sensor.

52. An apparatus according to claim 26, wherein said exposure condition includes a period for a converting operation of said image sensor.

56. An apparatus according to claim 26, wherein said light receiving mean has a wider dynamic range of characteristics than that of said image sensor.

57. An apparatus according to claim 26, wherein said light receiving means has faster responsive characteristics than that of said image sensor.

31. An image pick-up apparatus, comprising:

first light sensitive means for converting an object to an electrical signal;

second light sensitive means for detecting the brightness of the object, said second light sensitive means having a detecting characteristic different from that of said first light sensitive means; and

exposure control means for controlling an exposure condition of said first light sensitive means in correspondence with one of said light sensitive means, and then with the other of said light sensitive means.

32. An image pick-up apparatus as in claim 31, wherein said exposure control means includes means for controlling the amount of light on said first light sensitive means in response to both of said light sensitive means.

33. An image pick-up apparatus as in claim 31, wherein said exposure control means includes means for controlling the amount of light on said first light sensitive means in response to said second light sensitive means and then said first light sensitive means in sequence.

34. An image pick-up apparatus as in claim 31, wherein said exposure control means includes a controller for controlling light on said first light sensitive means and switching means for selectively coupling said first and second light sensitive means to said controller.

35. An image pick-up apparatus as in claim 34, wherein said first light sensitive means includes an image sensor and means for initiating an image pick-up operation for recording in said sensor, and said switching means serves for switching the coupling of said controller from said second light sensitive means to said first light sensitive means along with initiation of said image pick-up operation for recording in said sensor.

36. An image pick-up apparatus as in claim 31, wherein said first light sensitive means includes a diaphragm.

53. An apparatus according to claim 31, wherein said exposure condition includes a period for a converting operation of said first light sensitive means.

58. An apparatus according to claim 31 or 44, wherein said second light sensitive means has a wider dynamic range of characteristics than that of said first light sensitive means.

37. An image pick-up apparatus, comprising:

(a) image pick-up means for sensing an object image and converting said object image into an electrical signal;

(b) photo-sensing means for sensing a light condition of an object image, said photo-sensing means having sensing characteristics different from those of said image pick-up means; and

(c) control means for controlling the light condition of said object image relative to said image pick-up means by utilizing outputs of both said photo-sensing means and said image pick-up means.

38. An apparatus according to claim 37, wherein said control means controls the condition of said object image by controlling an exposure condition of said object image relative to said image pick-up means.

39. An apparatus according to claim 38, wherein said control means includes a diaphragm.

40. An apparatus according to claim 37, wherein said control means utilizes the outputs of both said photo-sensing means and said image pick-up means in sequence.

41. An apparatus according to claim 40, wherein a said control means utilizes the output of said photo-sensing means first and then the output of said image pick-up means.

42. An apparatus according to claim 40, which further includes means for recording the output of said image pick-up means.

43. An apparatus according to claim 42, wherein said control means utilizes the output of said photo-sensing means and then the output of said image pick-up means to form a signal for controlling the condition of said object image relative to said image pick-up means in a process for recording a predetermined output of said image pick-up means by said recording means.

54. An apparatus according to claim 37, wherein said light condition of said object image includes a period for a converting operation of said image pick-up means.

59. An apparatus according to claim 37, wherein said photo-sensing means has a wider dynamic range of characteristics than that of said image pick-up means.

60. An apparatus according to claim 37, wherein said photo-sensing means has faster responsive characteristics than that of said image pick-up means.

44. An image pick-up apparatus, comprising:

(a) image pick-up means having first light sensitive means for detecting an image of an object and generating an electrical signal;

(b) second light sensitive means for detecting a light condition of the object, said second light sensitive means having a detecting characteristic different from that of said first light sensitive means; and

(c) control means for controlling said image pick-up means to generate a predetermined electrical image signal in response to one and then the other of said light sensitive means in sequence.

45. An apparatus according to claim 44, wherein said control means includes means for controlling the image pick-up means in response to said second light sensitive means and then said first light sensitive means in sequence.

46. An apparatus according to claim 44, wherein said control means generates said predetermined electrical signal by controlling an exposure condition relative to said first light sensitive means.

47. An apparatus according to claim 46, wherein said image pick-up means includes a diaphragm and/or a shutter.

48. An apparatus according to claim 44, which further includes means for recording the output of said image pick-up means.

49. An apparatus according to claim 48, wherein said control means controls first the image pick-up means by an output of said second light sensitive means and then controls the image pick-up means by an output of said first light sensing means in a process for recording the predetermined electrical image signal of said image pick-up means by said recording means.

55. An apparatus according to claim 44, wherein said control means is able to control a period for generating the electrical signal in said first light sensitive means so as to generate said predetermined electrical image signal.