Inclination detecting apparatus and camera for detecting hand shake using the same

• US 5,369,462 A
• Filed: 06/07/1993
• Issued: 11/29/1994
• Est. Priority Date: 06/09/1992
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Mizobuchi, Kouji, Ide, Masataka, Imai, Yuji, Ito, Takeshi, Maruyama, Atsushi, Kikuchi, Juro, Miyazawa, Azuma
• Primary Examiner(s): PERKEY, WILLIAM B
• Application Number:
  US08/072,837
• Time in Patent Office: 540 Days
• Field of Search: 354/430, 354/403, 354/410, 356/1, 356/4
• US Class Current: 396/54
• CPC Class Codes: G01S 17/875 for determining attitude
• CPC Class Codes: G03B 17/00 Details of cameras or camera bodies; Accessories therefor lens hoods or caps G03B11/04
• CPC Class Codes: G03B 2217/005 Blur detection
• CPC Class Codes: G03B 7/091 Digital circuits
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors

Abstract

An inclination detecting apparatus includes a light projecting section, a light receiving section and an operating section. The light projection section projects light towards an object. The light receiving section receives lights reflected from at least two points of the object and outputs a photoelectric current signal. The operating section derives a difference between the reciprocals of the square roots of the photoelectric currents output from the light receiving section. An output of the operating section represents an inclination signal of the object. A shake detecting apparatus includes a light projecting/receiving section and an operating section. The light projecting/receiving section is disposed on the rear surface of a camera, so as to project light towards a photographer, receive lights reflected from at least two points on light receiving elements, and output photoelectric current signals for the respective points. The operating section derives a difference between the reciprocals of the square roots of the photoelectric currents output from the light receiving elements. An output of the operating section is used as a hand shake signal.

Claims

1. An inclination detecting apparatus comprising:

light projection means for projecting light towards a to-be-measured object;

light receiving means for receiving reflection light from said light projection means and outputting at east two photoelectric currents according to the respective received light amounts;

first operating means for deriving reciprocals of the square roots of the respective two photoelectric currents output from said light receiving means; and

second operating means for deriving a difference between the reciprocals of the square roots derived by said first operating means, an output of said second operating means representing the inclination of the to-be-measured object.

2. An inclination detecting apparatus according to claim 1, wherein said light projection means is constructed by one light projecting element and said light receiving means is constructed by two light receiving elements.

3. An inclination detecting apparatus according to claim 1, wherein said light projection means is constructed by two light projecting elements and said light receiving means is constructed by two light receiving elements, each of said light projecting elements and a corresponding one of said light receiving elements constituting a detecting section.

4. An inclination detecting apparatus according to claim 1, wherein said light projection means is constructed by first and second light projecting elements and said light receiving means is constructed by one light receiving element, a photoelectric current of said light receiving element being output in response to light projected from said first light projecting element at a first timing and output in response to light projected from said second light projecting element at a second timing.

5. An inclination detecting apparatus according to claim 1, wherein said light projection means includes at east one light emitting diode and a hood disposed around said light emitting diode.

6. An inclination detecting apparatus according to claim 1, wherein said light projection means projects infrared rays towards said to-be-measured object.

7. An inclination detecting apparatus according to claim 1, wherein said light receiving means includes at least two photodiodes disposed in positions separated from said light projecting means by a preset distance.

8. An inclination detecting apparatus according to claim 1, wherein said light receiving means is constructed by two light receiving elements which are arranged on both sides of said light projecting means.

9. An inclination detecting apparatus according to claim 1, wherein said light receiving means includes an eliminating circuit for eliminating an influence by a stationary light current component caused by stationary light from the photoelectric current.

10. An inclination detecting apparatus according to claim 1, wherein said inclination detecting apparatus is attached to a camera to detect hand shake of a user of said camera according to a variation in the output of said second operating means with time.

11. An inclination detecting apparatus according to claim 10, wherein said camera permits the exposure operation when the detected hand shake amount is set in a preset range.

12. An inclination detecting apparatus according to claim 10, wherein a plurality of light receiving sections are arranged on the rear surface of said camera to detect hand shake amounts in two directions.

13. An inclination detecting apparatus according to claim 1, wherein said first operating means includes multiplying means for multiplying a reciprocal of the square root of a photoelectric current derived by said first operating means by a coefficient.

14. An inclination detecting apparatus according to claim 13, wherein said coefficient is stored in an electrically programmable nonvolatile storing means.

15. An inclination detecting apparatus according to claim 1, wherein said second operating means includes multiplying means for multiplying a difference between reciprocals of the two square roots derived by said second operating means by a coefficient.

16. An inclination detecting apparatus according to claim 15, wherein said coefficient is stored in an electrically programmable nonvolatile storing means.

17. An inclination detecting apparatus according to claim 1, wherein said first operating means includes multiplying means for multiplying a reciprocal of the square root of a photoelectric current derived by said first operating means by a coefficient for correcting the reflection factor of said to-be-measured object.

18. An inclination detecting apparatus according to claim 17, wherein said coefficient for correcting the reflection factor is stored in an electrically programmable nonvolatile storing means.

19. An inclination detecting apparatus according to claim 1, wherein the operation of said first operating means is effected by an analog operation circuit and the operation of said second operating means is effected by a digital operation circuit.

20. An inclination detecting apparatus according to claim 1, wherein said first and second operating means are constructed by digital operation circuits.

21. An inclination detecting apparatus according to claim 1, further comprising:

adding means for adding together the two operation results derived by said first operating means for said two photoelectric currents, and

means for deriving an absolute inclination of said to-be-measured object by use of the above result of addition.

22. An inclination detecting apparatus according to claim 21, wherein variations in said light receiving means are corrected by use of correction values when said adding means effects said adding operation.

23. An inclination detecting apparatus according to claim 22, wherein correction values used for correcting said variations are stored in an electrically programmable nonvolatile storing means.

24. An inclination detecting apparatus according to claim 1, wherein said light receiving means receives reflection light from said light projecting means at at least three different positions, outputs at least three photoelectric currents corresponding to received light amounts and said first and second operating means derive inclinations in two axial directions based on said three photoelectric currents.

25. An inclination detecting apparatus according to claim 24, wherein said light projection means is disposed between two of said three positions of said light receiving means and third light receiving means is disposed on a line perpendicular to a line connecting said two positions of said light receiving means.

26. An inclination detecting apparatus according to claim 24, wherein said three positions are set at the same distance from said light projection means.

27. An inclination detecting apparatus according to claim 24, wherein said first operating means derives reciprocals of the square roots of said three photoelectric currents, and said second operating means derives the sum of reciprocals of the square roots of two of said three photoelectric currents and derives a difference between the sum of reciprocals and a reciprocal of the square root of the remaining one of said three photoelectric currents.

28. An inclination detecting apparatus according to claim 1, further comprising switching means disposed between said first operating means and said light receiving means, for selectively supplying one of said first and second photoelectric currents to said first operating means.

29. A camera comprising:

a camera body;

light projection means attached to said camera body, for projecting light towards a user of the camera;

light receiving means attached to said camera body, for receiving reflection light from said light projection means and outputting at least two photoelectric currents according to the respective received light amounts;

first operating means for deriving reciprocals of the square roots of the respective two photoelectric currents output from said light receiving means;

second operating means for deriving a difference between the two reciprocals of the square roots derived by said first operating means, an output of said second operating means representing the inclination of a to-be-measured object; and

hand shake amount detecting means for detecting a hand shake amount of the user of the camera according to a variation in an output of said second operating means with time.

30. A camera according to claim 29, wherein said light projecting means is constructed by one light projecting element and said light receiving means is constructed by two light receiving elements.

31. A camera according to claim 29, wherein said light projecting means is constructed by two light projecting elements and said light receiving means is constructed by two light receiving elements, each of said light projecting elements and a corresponding one of said light receiving elements constituting a detecting section.

32. A camera according to claim 29, wherein said light projection means is constructed by first and second light projecting elements and said light receiving means is constructed by one light receiving element, a photoelectric current of said light receiving element being output in response to light projected from said first light projecting element at a first timing and output in response to light projected from said second light projecting element at a second timing.

33. A camera according to claim 29, wherein said camera permits the exposure operation of said camera body when the detected hand shake amount is set in a preset range.

34. A camera according to claim 29, wherein a plurality of light receiving sections are arranged on the rear surface of said camera body to detect hand shake amounts in two directions.

35. A camera according to claim 29, wherein said first operating means includes multiplying means for multiplying a reciprocal of the square root of a photoelectric current derived by said first operating means by a coefficient.

36. A camera according to claim 35, wherein said coefficient is stored in an electrically programmable nonvolatile storing means.

37. A camera according to claim 29, wherein said first operating means includes multiplying means for multiplying the reciprocal of the square root of the photoelectric current derived by said second operating means by a coefficient for correcting the reflection factor of said to-be-measured object.

38. A camera according to claim 37, wherein said coefficient for correcting the reflection factor is stored in an electrically programmable nonvolatile storing means.

39. A camera according to claim 29, wherein the operation of said first operating means is effected by an analog operation circuit and the operation of said second operating means is effected by a digital operation circuit.

40. A camera according to claim 29, wherein said first and second operating means are constructed by digital operation circuits.

41. A camera according to claim 29, further comprising:

adding means for adding together the two operation results derived by said first operating means for said two photoelectric currents, and

means for deriving an absolute inclination of said to-be-measured object by use of the above result of addition.

42. A camera according to claim 41, wherein variations in said light receiving means are corrected by use of correction values when said adding means effects said adding operation.

43. A camera according to claim 42, wherein correction values used for correcting said variations are stored in an electrically programmable nonvolatile storing means.

44. A camera according to claim 29, wherein said light projecting means is attached to the rear surface of said camera body.

45. A camera according to claim 29, wherein said light receiving means includes an eliminating circuit for eliminating an influence by a stationary light current component caused by stationary light from the photoelectric current.

46. A camera according to claim 29, wherein said light receiving means receives reflection light from said light projecting means in at least three different positions, outputs at least three photoelectric currents corresponding to received light amounts and said first and second operating means derive inclinations in two axial directions based on said three photoelectric currents.

47. An inclination detecting apparatus comprising:

light projection means for projecting light towards a to-be-measured object;

light receiving means for receiving reflection light from said light projection means and for outputting at least first and second photoelectric currents according to the respective received light amounts;

first operating means for effecting a processing operation for the first and second photoelectric currents output from said light receiving means and for outputting first and second results of the processing operation, said first operating means deriving reciprocals of square roots of the first and second photoelectric currents;

correction operating means for subjecting at least one of the first and second results of the processing operation derived by said first operating means to a correcting operation by use of at least one correction value for correcting a variation in the first and second photoelectric currents; and

second operating means for deriving an inclination of said to-be-measured object by use of the first and second results of the processing operation correction by said correction operating means.

48. An inclination detecting apparatus according to claim 47, wherein said correction operating means effects the correcting operation by use of correction values for correcting variations in the first and second photoelectric currents caused by variations in said light projecting means and said light receiving means.

49. An inclination detecting apparatus according to claim 47, wherein said correction operating means effects the correcting operation by use of correction values for correcting a difference in the reflection factor of said to-be-measured object.

50. An inclination detecting apparatus according to claim 49, wherein said correction values are stored in an electrically programmable nonvolatile storing means.

51. An inclination detecting apparatus according to claim 48, wherein said correction values are stored in an electrically programmable nonvolatile storing means.

52. An inclination detecting apparatus according to claim 47, wherein said inclination detecting apparatus is attached to a camera to detect hand shake of a user of the camera according to a variation in the operation result of said second operating means with time.

53. An inclination detecting apparatus according to claim 52, wherein said camera permits a exposure operation when the detected hand shake amount is less than a preset value.

54. An inclination detecting apparatus comprising:

light projection means for projecting light towards a to-be-measured object;

light receiving means for receiving reflection light from said light projection means in at least three different positions and outputting at least three photoelectric currents according to the respective received light amounts;

first operating means for effecting the operation based on the first, second and third photoelectric currents output from said light receiving means; and

second operating means for deriving an inclination of said to-be-measured object in two axial directions based on the result of operation effected by said first operating means.

55. An inclination detecting apparatus according to claim 54, wherein said first operating means derives reciprocals of the square roots of the first, second and third photoelectric currents and said second operating means effects the arithmetic operation based on the reciprocals of the square roots.

56. An inclination detecting apparatus according to claim 54, wherein said light receiving means includes first and second light receiving elements arranged on both sides of said light projecting means and a third light receiving element disposed in a position different from said first and second light receiving elements.

57. An inclination detecting apparatus according to claim 56, wherein said second operating means detects an inclination in a first axial direction based on photoelectric currents output from said first and second light receiving elements, derives the sum of outputs of said first operating means for the photoelectric currents output from said first and second light receiving elements, and detects an inclination in a second axial direction based on the result of addition operation and the result of operation effected by said first operating means based on a photoelectric current output from said third light receiving element.

58. An inclination detecting apparatus according to claim 54, wherein said inclination detecting apparatus is attached to a camera to detect hand shake of said camera based on a variation in the result of operation effected by said second operating means with time.

59. An inclination detecting apparatus according to claim 58, wherein said camera permits the exposure operation when the detected hand shake amount is set less than a preset value.

60. An inclination detecting apparatus comprising:

a light projection element for projecting a light beam towards a to-be-measured object;

first, second and third light receiving elements for receiving light projected from said light projection element and reflected from said to-be-measured object;

first detecting means for detecting an inclination in a first axial direction according to photoelectric currents output from said first and second light receiving elements; and

second detecting means for detecting an inclination in a second axial direction according to photoelectric currents output from said second and third light receiving elements.

61. An inclination detecting apparatus according to claim 60, wherein said light receiving elements are disposed at substantially the same distance from said light projecting element.

62. An inclination detecting apparatus comprising:

light projection means for projecting light towards a to-be-measured object;

light receiving means for receiving reflection light from said light projection means and for outputting at least first and second photoelectric currents according to the respective received light amounts;

first operating means for effecting an arithmetic operation for the first and second photoelectric currents output from said light receiving means and for outputting first and second results of operation, said first operating means deriving reciprocals of the square roots of the respective first and second photoelectric currents;

second operating means for deriving an inclination of said to-be-measured object by use of the first and second results of operation; and

stationary light eliminating means for eliminating an influence on the first and second photoelectric currents by stationary light contained in the reflection light from said to-be-measured object.

63. An inclination detecting apparatus according to claim 62, wherein said stationary light elimination means stores output levels of currents of said light receiving means for the first and second photoelectric currents obtained prior to light projection by said light projecting means and outputs values obtained by subtracting the stored currents as the respective photoelectric currents at the time of light projection by said light projecting means.

64. An inclination detecting apparatus according to claim 62, wherein said inclination detecting apparatus is incorporated into a camera to detect hand shake of a user of said camera according to an output representing the inclination derived by said second operating means.

65. An inclination detecting apparatus incorporated in a camera to detect hand shake of a user camera, the inclination detecting apparatus comprising:

light projection means for projecting light towards a to-be-measured object;

light receiving means for receiving reflection light from said light projection means and for outputting at least one photoelectric current according to the received light amount;

operating means for producing an output representing an inclination of said to-be-measured object based on the at least one photoelectric current output from said light receiving means;

stationary light eliminating means for eliminating an influence on the photoelectric current by stationary light contained in the reflection light from said to-be-measured object, and

wherein said inclination detecting apparatus incorporated into a camera detects hand shake of a user of said camera according to the output produced by said operating means.

66. A non-contact type inclination detecting apparatus comprising:

light projection means for projecting light towards a to-be-measured object;

light receiving means for receiving light reflected from said to-be-measured object and outputting a photoelectric current signal;

first operating means for deriving a reciprocal of the square root of the photoelectric current signal output from said light receiving means; and

second operating means for deriving an inclination of said to-be-measured object based on an output of said first operating means.

67. A non-contact type inclination detecting apparatus according to claim 66, wherein said light receiving means includes eliminating means for eliminating an influence of light other than light projected from said light projecting means.

68. A non-contact type inclination detecting apparatus according to claim 66, wherein said light projection means and said light receiving means are arranged on substantially the same plane.

69. A non-contact type inclination detecting apparatus according to claim 66, wherein said light receiving means includes first and second light receiving elements and said light projecting means includes a single light projecting element.

70. A non-contact type inclination detecting apparatus according to claim 66, wherein said light projecting means includes a single light projecting element and said light receiving means includes first, second and third light receiving elements, said third light receiving element being disposed on a perpendicular passing an intermediate point between said first and second light receiving elements.

71. A shake detecting apparatus of a camera comprising:

light projection means for projecting light towards the exterior of the camera;

light receiving means for receiving light projected from said light projection means and reflected from the preset surface of an object lying outside the camera, and outputting a light signal, said light receiving means including eliminating means for eliminating an influence of light other than light projected from said light projecting means; and

operating means for deriving a shake signal of the camera based on a variation in an output from said light receiving means.

72. A shake detecting apparatus according to claim 71, wherein said operating means derives a difference between reciprocals of the square roots of light signals output from said light receiving means according to amounts of light reflected from points on said preset surface and received by said light receiving means.

73. A shake detecting apparatus according to claim 71, wherein said light projecting means and said light receiving means are arranged near the finder of the camera.

74. A shake detecting apparatus according to claim 71, wherein said light receiving means includes first and second light receiving elements and said light projecting means includes a single light projecting element.

75. A shake detecting apparatus according to claim 71, wherein said light projecting means includes a single light projecting element and said light receiving means includes first, second and third light receiving elements, said third light receiving element being disposed on a perpendicular passing an intermediate point between said first and second light receiving elements.

76. A shake detecting apparatus of a camera comprising:

light projection means for projecting light towards the photographer of the camera;

light receiving means for receiving light projected from said light projection means and reflected from part of the body of the photographer, and outputting a light signal, said light receiving means including eliminating means for eliminating an influence of light other than light projected from said light projecting means; and

operating means for deriving a shake signal of the camera based on a variation in an output from said light receiving means.

77. A shake detecting apparatus according to claim 76, wherein said light receiving means receives light projected from said light projection means and reflected from at least two points on the body of the photographer and outputting light signals, and said operating means derives a difference between reciprocals of the square roots of the light signals corresponding to lights reflected on said points.

78. A shake detecting apparatus according to claim 76, wherein said light projecting means and said light receiving means are arranged near the finder of the camera.

79. A shake detecting apparatus according to claim 76, wherein said light receiving means includes first and second light receiving elements and said light projecting means includes a single light projecting element.

80. A non-contact type inclination detecting apparatus comprising:

light projection means for projecting light towards a to-be-measured object;

light receiving means including three light receiving elements for receiving reflection light from said light projection means;

processing means for processing outputs of said light receiving means; and

operating means for deriving inclinations of the to-be-measured object in preset two axial directions with respect to a reference surface according to an output from said processing means.

81. A non-contact type inclination detecting apparatus according to claim 80, wherein said light receiving means includes eliminating means for eliminating an influence of light other than light projected from said light projecting means.

82. A non-contact type inclination detecting apparatus according to claim 80, wherein each of said light receiving means disposed at substantially the same distance from said light projecting means.

83. A non-contact type inclination detecting apparatus according to claim 80, wherein said light projecting means includes a single light projecting element and said light receiving means includes first, second and third light receiving elements, said third light receiving element being disposed on a perpendicular passing an intermediate point between said first and second light receiving elements.

84. A non-contact type inclination detecting apparatus comprising:

light projection means for projecting light towards a to-be-measured object;

light receiving means for receiving reflected light from said to-be-measured object and outputting photoelectric current signals;

first operating means for deriving reciprocals of the square roots of the respective photoelectric current signals output from said light receiving means;

means for correcting outputs from said first operating means; and

second operating means for deriving an inclination of said to-be-measured object based on an output from said correction means.

85. A non-contact type inclination detecting apparatus according to claim 84, wherein said light receiving means includes eliminating means for eliminating an influence of light other than light projected from said light projecting means.

86. A non-contact type inclination detecting apparatus according to claim 84, wherein said correction means includes storing means for storing correction coefficients used for correcting the output of said first operating means.

87. A non-contact type inclination detecting apparatus according to claim 84, wherein said light projecting means and said light receiving means are disposed on substantially the same plane.

88. A non-contact type inclination detecting apparatus according to claim 84, wherein said light receiving means includes first and second light receiving elements and said light projecting means includes a single light projecting element.

89. A non-contact type inclination detecting apparatus according to claim 84, wherein said light projecting means includes a single light projecting element and said light receiving means includes first, second and third light receiving elements, said third light receiving element being disposed on a perpendicular passing an intermediate point between said first and second light receiving elements.

90. A shake detecting apparatus of a camera comprising:

light projection means for projecting light towards the exterior of the camera;

light receiving means for receiving light projected from said light projection means and reflected from the preset surface of an object lying outside the camera, and outputting a light signal;

means for correcting an output of said light receiving means; and

operating means for deriving a shake signal of the camera based on a variation in an output from said correction means.

91. A shake detecting apparatus according to claim 90, wherein said light receiving means includes eliminating means for eliminating an influence of light other than light projected from said light projecting means.

92. A shake detecting apparatus according to claim 90, wherein said correction means includes storing means for storing correction coefficients used for correcting the output of said first operating means.

93. A shake detecting apparatus according to claim 90, wherein said operating means derives a difference between reciprocals of the square roots of light signals output from said light receiving means and corresponding to amounts of lights reflected from at least two points on said preset surface.

94. A shake detecting apparatus according to claim 90, wherein said light projection means and said light receiving means are disposed on that side of said camera on which a finder is arranged.

95. A shake detecting apparatus according to claim 90, wherein said light receiving means includes first and second light receiving elements and said light projecting means includes a single light projecting element.

96. A shake detecting apparatus according to claim 90, wherein said light projecting means includes a single light projecting element and said light receiving means includes first, second and third light receiving elements, said third light receiving element being disposed on a perpendicular passing an intermediate point between said first and second light receiving elements.

97. An inclination detecting apparatus of a camera comprising:

detection means disposed on a body of said camera, for detecting an inclination of said camera with respect to the face of the photographer of the camera;

wherein said detection means includes at least light projection means and light receiving means, and can detect an inclination of said camera with respect to the face of the photographer and a distance between said camera and the face of the photographer, the sensitivity with which a variation in the inclination is detected is higher than the sensitivity with which a variation in the distance is detected.

98. An inclination detecting apparatus according to claim 97, said light receiving means includes eliminating means for eliminating an influence of light other than light projected from said light projecting means.

99. A shake detecting apparatus of a camera, comprising:

light projecting means for projecting light towards a to-be-measured object;

light receiving means for receiving reflection light from said light projecting means, and outputting at least first and second photoelectric currents in accordance with the respective received light amounts;

first operation means for performing operations on the first and second photoelectric currents output from said light receiving elements, and outputting first and second operation results;

correcting operation means for subjecting at least one of the first and second operation results derived by said first operation means to a correcting operation by use of a correction value for correcting a variation in the first and second photoelectric currents; and

second operation means for deriving an inclination of the to-be-measured object by use of the first and second operation results corrected by said correcting operation means; and

shake detecting means for detecting hand shake of a user of the camera in accordance with how the operation result of said second operation means varies with time.

100. A shake detecting apparatus according to claim 99, wherein said first operation means derives reciprocals of the square roots of the first and second photoelectric currents.

101. A shake detecting apparatus according to claim 99, wherein said correcting operation means effects the correcting operation by use of correction values for correcting variations in the first and second photoelectric currents caused by variations in said light projecting means and said light receiving means.

102. A shake detecting apparatus according to claim 99, wherein said correcting operation means effects the correcting operation by use of correction values for correcting a difference in the reflection factor of said to-be-measured object.

103. A shake detecting apparatus according to claim 101, wherein said correction values are stored in an electrically programmable nonvolatile storing means.

104. A shake detecting apparatus according to claim 102, wherein said correction values are stored in an electrically programmable nonvolatile storing means.

105. A shake detecting apparatus according to claim 99, wherein said camera permits an exposure operation when the detected hand shake amount is less than a preset value.

106. A shake detecting apparatus of a camera, comprising:

light projecting means for projecting light towards a to-be-measured object;

light receiving means for receiving reflection light from said light projecting means, and outputting at least first and second photoelectric currents in accordance with the respective received light amounts;

first operation means for performing operations on the first and second photoelectric currents output from said light receiving means, and outputting first and second operation results;

second operation means for deriving an inclination of the to-be-measured object by use of said first and second operation results;

stationary light eliminating means for eliminating an influence of stationary light contained in the reflection light from the to-be-measured object upon the first and second photoelectric currents; and

shake detecting means for detecting hand shake of a user of a camera in accordance with how an output of said second operation means varies with time.

107. A shake detecting apparatus according to claim 106, wherein said stationary light eliminating means stores output levels of currents of said light receiving means for the first and second photoelectric currents obtained prior to light projection by said light projecting means, and wherein values obtained by subtracting the stored currents are output as the respective photoelectric currents at the time of light projection by said light projecting means.

108. A shake detecting apparatus according to claim 106, wherein said first operation means derives reciprocals of the square roots of the respective first and second photoelectric currents.