Exposure control apparatus for camera

• US 5,086,314 A
• Filed: 01/22/1991
• Issued: 02/04/1992
• Est. Priority Date: 05/21/1990
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Miyamoto, Hidenori, Aoki, Hitoshi, Tsukahara, Daiki, Wakabayashi, Hiroshi
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Gray, David M.
• Application Number:
  US07/644,232
• Time in Patent Office: 378 Days
• Field of Search: 354/410-424, 354/429-434
• US Class Current: 396/61
• CPC Class Codes: G03B 17/18 Signals indicating condition of a camera member or suitability of light indicating depth of field G03B13/30
• CPC Class Codes: G03B 7/08 Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
• CPC Class Codes: G03B 7/093 for control of exposure time
• CPC Class Codes: G03B 7/16 in accordance with both the intensity of the flash source and the distance of the flash source from the object, e.g. in accordance with the "guide number" of the flash bulb and the focusing of the camera
• CPC Class Codes: G03B 7/22 in accordance with temperature or height, e.g. in aircraft

Abstract

There is disclosed an exposure control apparatus for a camera, enabling appropriate exposure control for varied photographing situations. The apparatus determines the optimum exposure value, referring to various conditions including the season and time of photographs, photographing location, sunrise/sunset times and so on.

Claims

1. An exposure control apparatus for a camera provided with a flash unit, comprising:

means for determining an exposure value according to the luminance of an object;

means for controlling said flash unit so as to effect the photographing operation with flash emission when said object luminance is equal to or less than a predetermined level;

means for supplying information on time;

means for discriminating whether the current time is a twilight time, based on said time information; and

means for reducing said predetermined level of said control means by a predetermined amount when the current time is identified as a twilight time.

2. An apparatus according to claim 1, further comprising means for correcting the exposure value determined by said exposure value determining means to the underexposure side by a predetermined amount in comparison with the normal exposure value when said twilight time is identified.

3. An exposure control apparatus for a camera provided with a flash unit, comprising:

means for detecting the luminance of an object;

means for controlling said flash unit so as to effect the photographing operation with flash emission when said object luminance is equal to or less than a predetermined level;

means for discriminating whether the photographing situation is indoors or outdoors;

means for supplying information on time;

means for discriminating whether the current time is a twilight time, based on said time information; and

means for reducing said predetermined level of said control means by a predetermined amount, when the photographing situation is identified as outdoors and in the twilight time.

4. An apparatus according to claim 3, further comprising means for detecting the object distance, wherein said flash unit control means is adapted to cause flash emission from said flash unit when said detected object distance is short.

5. An exposure control apparatus for a camera provided with a flash unit, comprising:

means for detecting the luminance of an object;

flash control means for controlling said flash unit so as to effect the photographing operation with flash emission when said object luminance is equal to or less than a predetermined level;

means for discriminating whether the photographing situation is indoors or outdoors;

means for supplying information on time;

means for supplying information on date;

means for supplying geographical information;

means for detecting the sunrise time and the sunset time based on said date information and said geographical information;

means for discriminating whether the current time is a twilight time, based on said time information and said sunrise/sunset times; and

means for reducing said predetermined level of said control means by a predetermined amount, when the photographing situation is identified as outdoors and in the twilight time.

6. An apparatus according to claim 5, further comprising means for measuring the object distance, wherein said flash control means is adapted to cause flash emission from said flash unit when said measured object distance is short.

7. An apparatus according to claim 5, wherein said outdoors/indoors discriminating means comprises means for detecting the color temperature of the light source in said photographing situation.

8. An apparatus according to claim 5, wherein said outdoors/indoors discriminating means comprises means for detecting the frequency of the light source in said photographing situation.

9. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

season information supplying means for supplying electrical season information corresponding to information of a season; and

exposure value determining means for determining exposure value for an object on the basis of said luminance information and said season information.

10. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

season information generating means having means for counting time electrically, the season information generating means generating electrical season information indicative of the current season information on the basis of the counted time; and

exposure value determining means for determining exposure value based on said luminance information and said season information.

11. An exposure control apparatus according to claim 9 or 10, wherein said exposure value determining means determines said exposure value so that said exposure value may be larger than the normal exposure value obtained on the basis of said luminance information by a predetermined value.

12. An exposure control apparatus according to claim 9 or 10, further comprising:

data and time information generating means for counting electrically date and time information and generating the electrical date and time information which shows the current data and time; and

wherein

said exposure value determining means determining said exposure value so that said exposure value is above the normal exposure value obtained on the basis of said luminance information by a predetermined value when said season is summer or winter and said time indicated by said date and time information is daytime.

13. An exposure control apparatus according to claim 9 or 10,

said exposure value determining means having normal exposure mode for determining exposure value on the basis of said luminance information and specific exposure mode for determining exposure value on the basis of said luminance information and said season information;

and further comprising

exposure mode switching means for switching over between said normal exposure mode and said specific exposure mode.

14. An exposure control apparatus according to claim 13, further comprising:

time information generating means for generating electrical time information indicative of the current time; and

said exposure mode switching means effecting a switching-over operation between said normal exposure mode said specific exposure mode on the basis of said time information.

15. An exposure control apparatus according to claim 14, wherein

time information generated by said time information generating means includes electrical night time information indicting that it is night;

and

said exposure mode switching means switching from said specific exposure mode to said normal exposure mode in response to said night information.

16. An exposure control apparatus according to claim 13, comprising:

indoor/outdoor discriminating means for discriminating whether photographing environment is in indoor or outdoor and generating electrical indoor information if the photographing environment is indoor and electrical outdoor information if the photographing environment is outdoor,

said exposure mode switching means allowing to switch to said specific exposure mode in response to said outdoor information and to said normal exposure mode in response to said indoor information.

17. An exposure control apparatus according to claim 16, wherein said indoor/outdoor discriminating means includes color temperature detecting means for detecting color temperature of light source in said photographing environment and discriminating whether the environment is indoor or outdoor on the basis of the result of the color temperature detection.

18. An exposure control apparatus according to claim 16, said indoor/outdoor discriminating means includes frequency detecting means for detecting frequency of light source in said photographing environment and discriminating whether the environment is indoor or outdoor on the basis of the result of the frequency detection.

19. An exposure control apparatus according to claim 13, wherein

said specific exposure mode includes:

spring mode in which slightly over-exposure is obtained than said normal exposure mode is obtained when said luminance information is above a first predetermined value;

summer mode in which more over-exposure than said spring mode is obtained;

autumn mode in which exposure substantially equal to said normal exposure mode is obtained; and

winter mode exposure which is under-exposure than said normal exposure mode is obtained when said luminance information is below a second predetermined value, and exposure which is over-exposure than the summer mode is obtained when said luminance information is above the second predetermined value; and

specific exposure mode switching means for selecting switching over, among said for specific exposure modes, to one which corresponds to a season indicated by said season information.

20. An exposure control apparatus according to claim 19, wherein said first predetermined value and said second predetermined value are different from each other.

33. An exposure control apparatus according to claim 9, 10, 21 or 27, further comprising:

light sensitive film receiving means for receiving light sensitive film loaded in said camera, the light sensitive film having latitude information indicative of its own latitude; and

latitude detection means for detecting latitude information of said light sensitive film received in said film receiving means;

said exposure value determining means determining said exposure value based on said season information and said latitude information.

37. An exposure control apparatus according to claim 9, 10, 21 or 27, further comprising:

an operating member for starting before-exposure operation of a camera when firstly operated and causing exposure when secondly operated;

said exposure value determining means effecting exposure value determining operation when said operating member is firstly operated.

64. An exposure control apparatus according to claim 12, further comprising:

display means electrically displaying said date and time information.

65. An exposure control apparatus according to claim 64, further comprising:

phototaking means for phototaking said date and time information displayed on the displaying means into means to be exposed.

66. An exposure control apparatus according to claim 65, wherein said means to be exposed includes a photosensitive film.

67. An exposure control apparatus according to claim 13, further comprising:

display means electrically displaying said date and time information.

68. An exposure control apparatus according to claim 67, further comprising:

phototaking means for phototaking said date and time information displayed on the displaying means into means to be exposed.

69. An exposure control apparatus according to claim 68, wherein said means to be exposed includes a photosensitive film.

21. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

summer season information generating means having time counting means for counting time electrically, the summer season information generating means generating electrical summer information based on the time counting if it is summer, and exposure value determining means for determining exposure value on the basis of said luminance information and said summer season information.

22. An exposure control apparatus according to claim 21, wherein said exposure value determining means determines said exposure value to be over by a predetermined value than normal exposure value which is obtained based on said luminance information.

23. An exposure control apparatus according to claim 21, further comprising

date and time information generating means for counting electrically date and time information and generating electrical information indicative of the present date and time;

said exposure value determining means determining exposure value to be over by a predetermined value than normal exposure value obtained based on said luminance information, when said summer season information generating means generating said summer season information and time represented by said date and time information is daytime.

24. An exposure control apparatus according to claim 21, wherein

said exposure value determining means has a normal exposure mode and summer season exposure mode, the normal exposure mode determining exposure value based on said luminance information and the summer season exposure mode determining exposure value based on said luminance information and said summer season information;

and further comprising

exposure mode switching means for switching to said summer season exposure mode according to said summer season information.

25. An exposure control apparatus according to claim 24, further comprising:

time information generating means for generating electrical time information indicative of the present time;

said exposure mode switching means changing over between said normal exposure mode and said summer season exposure mode by said time information.

26. An exposure control apparatus according to claim 24, further comprising:

indoor/outdoor discriminating means for discriminating whether the photographing environment is indoor or outdoor, and generating electrical indoor information if the environment is indoor and electrical outdoor information if the environment is outdoor;

said exposure mode switching means allowing to change over to said summer season exposure mode in response to said outdoor information and allowing to change over to said normal exposure mode in response to said indoor information.

27. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

winter season information generating means having time counting means for counting time electrically and generating electrical winter season information if it is winter at present on the basis of the counted time; and

exposure value determining means for determining exposure value based on said luminance information and said winter season information.

28. An exposure control apparatus according to claim 27, wherein

said exposure value determining means determines said exposure value to be over by a predetermined value than normal exposure value obtained based on said luminance information.

29. An exposure control apparatus according to claim 27, further comprising:

date and time information generating means for counting electrically date and time information and generating electrical date and time information indicating the current date and time;

said exposure value determining means, when said winter season information generating means generates said winter season information and time represented by said date and time information is daytime, determining said exposure value to be a predetermined value over than normal exposure value obtained based on said luminance information.

30. An exposure control apparatus according to 27, further having:

a plurality of exposure modes including a normal exposure mode and an winter season exposure mode, the normal exposure mode determining exposure value based on said luminance information and the winter season exposure mode determining exposure value based on said luminance information and said winter season information; and

exposure mode switching means for switching to said winter season exposure mode corresponding to said winter season information.

31. An exposure control apparatus according to claim 30, further comprising:

time information generating means for generating electrical time information representative of the current time;

said exposure mode switching means effecting change over operation between said normal exposure mode and said winter season exposure mode according to said time information.

32. An exposure control apparatus according to claim 30, further comprising:

indoor/outdoor discriminating means for discriminating whether a photographing environment is indoor or outdoor and generating electrical indoor information if the environment is indoor and electrical outdoor information if the environment is outdoor;

said exposure mode switching means allowing to change over to said winter season exposure mode in response to said outdoor information and to said normal exposure mode in response to said indoor information.

34. An exposure control apparatus according to claim 29, further comprising:

display means electrically displaying said date and time information.

35. An exposure control apparatus according to claim 34, further comprising:

phototaking means for phototaking said date and time information displayed on the displaying means into means to be exposed.

36. An exposure control apparatus according to claim 35,

wherein said means to be exposed includes a photosensitive film.

38. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

time information generating means for counting time electrically and generating electrical time information indicative of the current time; and

exposure value determining means for determining exposure value for an object based on said luminance information and said time information.

39. An exposure control apparatus according to claim 38, further comprising:

photosensitive film receiving means for receiving a photosensitive film loaded in said camera, the photosensitive film having latitude information indicating its own latitude; and

latitude detecting means for detecting said latitude information of said photosensitive film received in said photosensitive film receiving means;

said exposure value determining means determining said exposure value on the basis of said luminance information, said time information and said latitude information.

40. An exposure control apparatus according to claim 38, further comprising:

display means for displaying electrically said time information.

41. An exposure control apparatus according to claim 40, further comprising:

phototaking means for phototaking time information indicated by said display means into means to be exposed.

42. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

twilight discriminating means having time counting means for counting time electrically and discriminating whether it is twilight at present based on the counted time and generating electrical twilight information when it is twilight; and

exposure value determining means determining exposure value for an object to be a predetermined value under in comparison with exposure value at the time of non-twilight time when said twilight information is received.

43. An exposure control apparatus according to claim 42, further comprising:

indoor/outdoor discriminating means for discriminating whether a photographing environment is indoor or outdoor and generating electrical outdoor information if the environment is outdoor and electrical indoor information if the environment is indoor; and

said exposure determining means determining normal exposure value corresponding to said indoor information and said luminance information and determining exposure value a predetermined value less than said normal exposure value according to said outdoor information and said twilight information.

44. An exposure control apparatus according to claim 42, wherein

said twilight discriminating means includes a twilight time information generating means which generates, on the basis of said counted time, electrical sunrise information indicating time of sunrise and sunset information indicating time of sunset;

said exposure value determining means having normal exposure mode in which exposure value is determined based on said luminance information and sunrise mode in which a first exposure value is determined based on said luminance information and said sunrise information and sunset mode in which a second exposure value which is lower than said first exposure value is determined based on said luminance information and said sunset information; and

including

exposure mode changing means effecting a change-over operation between a normal exposure mode and said sunrise mode according to said sunrise information and effecting a change-over operation between said normal exposure mode and said sunset mode according to said sunset information.

45. An exposure control apparatus according to claim 42, wherein

said twilight discriminating means includes sunrise related information generating means for generating electrical sunrise time information indicative of sunrising time and electrical sunrising term information indicating a predetermined time interval in which said sunrising time is included, on the basis of said counted time;

and including

sunset related information generating means for generating electrical sunset time information indicating sunsetting time and electrical sunsetting term information indicating a predetermined time interval in which said sunset time is included, on the basis of said counted time;

said exposure value determining means including normal exposure mode in which exposure value is determined on the basis of said luminance information, sunrise mode where exposure value is determined on the basis of said luminance information and said sunrise related information, wherein at the time indicated by said sunrise time information exposure value for sunrise which is lower than normal exposure value obtained at said normal exposure mode is obtained, and at the time interval indicated by said sunrise term information exposure value which is more than said normal exposure value and which becomes higher than said exposure value for sunrise in accordance with time difference from said time indicated by said sunrise time information becomes larger;

sunset mode for determining exposure value on the basis of said luminance information and said sunset related information, and wherein at the time indicated by said sunset time information, exposure value for sunset which is lower than normal exposure value obtained at the time of said normal exposure mode, in the time period indicated by said sunset term information exposure value which is higher than the exposure value for said sunset and which is lower than said normal exposure value is obtained in accordance with a time difference from time indicated by said sunset time information being increased; and

exposure mode changing means for effecting a change-over operation between said normal exposure mode and said sunrise mode according to said sunrise related information and effecting a witching-over operation between said normal exposure ode and said sunset mode according to said sunset information.

46. An exposure control apparatus according to claim 45, wherein said exposure value for sunrise is lower than said exposure value for sunset.

47. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

date information generating means for counting time electrically and generating electrical date information indicative of the current date;

geographical information generating means for generating electrical phototaking place information which is information indicative of a phototaking place on the Earth;

date information correcting means for correcting said date information on the basis of said phototaking plate information;

season recognizing means for recognizing the current season on the basis of said date information and said phototaking place information and the basis of said correction date information and said phototaking place information and generating electrical season information indicative of the recognized season;

exposure value determining means for determining an exposure value against an exposure value for an object on the basis of said luminance information and said season information.

48. An exposure control apparatus according to claim 47, further comprising:

display means for electrically displaying said correction date information and said geographic information and said date information.

54. An exposure control apparatus according to claim 47 or 49, wherein said geographic information includes latitude and longitude of the photographing place.

55. An exposure control apparatus according to claim 47 or 49, wherein said geographic information generating means includes phototaking position designating means for generating electrical phototaking position information indicating a phototaking position designated by an operation effected by a user;

and

displaying means for effecting a display according to the phototaking position indicated by said phototaking position information.

56. An exposure control apparatus according to claim 55, wherein said phototaking position designating means includes specific code inputting means for inputting specific code corresponding to phototaking position and generating electrical phototaking position information corresponding to the code when the specific code is inputted.

57. An exposure control apparatus according to claim 55, wherein said phototaking position designating means includes map displaying means for displaying map on a coordinate system;

and

a coordinate position specifying means for specifying a coordinate position on said map and generating electrical coordinate position information corresponding to the position specified.

49. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

geographic information generating means for generating electrical phototaking place information indicating a phototaking place on the Earth;

time information generating means for counting time electrically and generating electrical time information indicative of the current time;

time information correcting means for correcting said time information to a time of the place indicated by said phototaking place information on the basis of said phototaking place information;

twilight information generating means for producing twilight information relating to sunrise and sunset times on the basis of said phototaking place information and said correction time information and generating electrical twilight information according to said twilight information; and

exposure value determining means for determining exposure value on the basis of said luminance information and said twilight information.

50. An exposure control apparatus according to claim 49, further comprising:

indoor/outdoor discriminating means for discriminating whether a phototaking environment is indoor or outdoor and generating indoor information if the environment is indoor and outdoor information if the environment is outdoor;

said exposure value determining means determining exposure value to be a predetermined amount under than normal exposure value which is obtained on the basis of said luminance information according to said twilight information and said outdoor information.

51. An exposure control apparatus according to claim 49, further having:

a plurality of exposure modes comprising normal exposure mode in which exposure value is determined on the basis of said luminance information, and summer time exposure mode in which exposure value is determined on the basis of said luminance information and said correction time information; and

exposure mode switching means for effecting a switch-over operation between said normal exposure mode and said summer time exposure mode on the basis of said phototaking information.

52. An exposure control apparatus according to claim 51, further comprising:

time correction manual setting means for correcting said time information by a predetermined time when first operated and returning said correcting time information to time information which has not been corrected when second operated.

53. An exposure control apparatus according to claim 49, further comprising:

display means for displaying electrically said time information, said correction time information and said geographic information.

58. An exposure control apparatus for a camera, comprising:

luminance information generating means for generating electrical luminance information corresponding to a luminance of an object;

reference time generating means for counting electrically a reference time and generating reference time information indicative of the current reference time;

photographing position designating means for designating latitude and longitude of the photographing position and generating latitude information and longitude information corresponding to the designation;

height-of-sun calculating means for calculating the current height of the sun on the basis of said latitude information, said longitude information and said reference time information; and

exposure value determining means for determining exposure value on the basis of said luminance information and said height of the sun.

59. An exposure control apparatus according to claim 58, wherein

said exposure value determining means includes exposure value calculating means for calculating exposure value according to said luminance information, and exposure value correcting means for correcting exposure value calculated by the exposure value calculating means when the height of the sun is within a predetermined range.

60. An exposure control apparatus according to claim 59, wherein said exposure value correcting means corrects the calculated exposure value toward under-exposure in the case where said height of the sun is lower than a predetermined value and corrects toward over-exposure in the case where said height of the sun is in the range above a predetermined value.

61. An exposure control apparatus according to claim 58, wherein said phototaking position designating means includes map displaying means for displaying a map on a coordinate system and coordinate position specifying means for specifying a coordinate position on the map.

62. An exposure control apparatus according to claim 61, further comprising:

enlarged displaying means for displaying enlarged a position specified by said coordinate position specifying means.

63. An exposure control apparatus according to claim 58, further comprising:

height-above-sea level setting means for setting the height above sea level of a phototaking position and generating height-above-sea level information corresponding to the said height above sea level;

height-of-sun correcting means for correcting the height of the sun calculated by said height-of-sun calculating means on the basis of said height-above-sea level information; and

said exposure value determining means determining exposure value on the basis of said corrected height of the sun and said luminance information.