Exposure control apparatus for camera with shake countermeasure

• US 5,237,365 A
• Filed: 09/22/1992
• Issued: 08/17/1993
• Est. Priority Date: 10/15/1990
• Status: Expired due to Term

• Current Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Miyazawa, Azuma
• Primary Examiner(s): PERKEY, WILLIAM B
• Application Number:
  US07/951,307
• Time in Patent Office: 329 Days
• Field of Search: 354/430, 354/202, 354/266, 354/267.1, 354/268, 354/238.1, 354/456, 354/458
• US Class Current: 396/49
• CPC Class Codes: G03B 2207/005 involving control of motion blur
• CPC Class Codes: G03B 2217/005 Blur detection
• CPC Class Codes: G03B 7/093 for control of exposure time
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/684 performed by controlling the image sensor readout, e.g. by controlling the integration time
• CPC Class Codes: H04N 23/689 Motion occurring during a rolling shutter mode
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: Y10S 706/90 Fuzzy logic

Abstract

A shake amount detecting section repeatedly detects shaking of a camera in a sampling time interval shorter than a hand shaking cycle. An exposure calculating section calculates a shutter speed based on the sensitivity of a film and the brightness of an object. A data processing section acquires processed data from a product of the shutter speed and the amount of shaking, every time the amount of shaking is detected. A storage section stores the processed data output. A shake amount predicting section receives the processed data and the processed data stored in the storage section to predict the total amount of shaking while the shutter is open, every time the processed data is output from the data processing section. A release switch instructs the beginning of an exposing operation on the film. A shutter enable discriminating section discriminates permission of a shutter release when a latest predicted total amount of shaking during shutter opening, output from the shake amount predicting section, is equal to or smaller than a predetermined amount, every time the release switch is operated and the shake amount predicting section predicts the total amount of shaking. A shutter controller starts opening the shutter based on a signal from the shutter enable discriminating section and controls an exposure time based on the shutter speed.

Claims

1. An exposure control apparatus for a camera comprising:

shake amount detecting means for repeatedly detecting shaking of a camera in a sampling time interval shorter than a hand shaking cycle;

exposure calculating means for calculating a shutter speed concerning an opening of a shutter of said camera based on a sensitivity of a film to be loaded in said camera and brightness information of a object to be picked up by said camera;

data processing means for acquiring processed data from a product of said shutter speed calculated by said exposure calculating means and an amount of shaking detected by said shake amount detecting means every time said amount of shaking is detected by said shake amount detecting means;

storage means for storing said processed data output from said data processing means;

shake amount predicting means for receiving said processed data from said data processing means and said processed data stored in said storage means to predict a total amount of shaking while said shutter is open, every time said processed data is output from said data processing means;

a release switch for preparing for beginning of an exposing operation on said film;

shutter enable discriminating means for discriminating permission of a shutter release when a latest predicted total amount of shaking during shutter opening, output from said shake amount predicting means, is equal to or smaller than a predetermined amount, every time said release switch is operated and said shake amount predicting means predicts said total amount of shaking; and

shutter control means for starting opening said shutter based on a signal from said shutter enable discriminating means and controlling an exposure time based on said shutter speed calculated by said exposure calculating means.

2. An exposure control apparatus according to claim 1, wherein said shutter enable discriminating means makes discrimination in light of a shutter time lag from the beginning of said shutter opening to the beginning of actual exposure.

3. An exposure control apparatus according to claim 1, wherein said shake amount predicting means performs prediction by linear approximation.

4. An exposure control apparatus according to claim 1, wherein said shake amount predicting means performs prediction using fuzzy prediction.

5. An exposure control apparatus for a camera comprising:

shutter-speed determining means for determining a shutter speed concerning an opening of a shutter of a camera;

shake amount detecting means for detecting an amount of shaking of said camera for each sampling time;

shutter timing generating means for generating a shutter release signal to instruct an exposing operation of a film loaded into said camera;

maximum wait time determining means for determining a maximum wait time from generation of said shutter release signal from said shutter timing generating means to generation of a shutter enable signal based on an output of said shutter-speed determining means;

allowable shake amount determining means for determining a maximum allowable amount of shaking based on said output of said shutter-speed determining means;

minimum value storage means for storing a minimum value of said amount of shaking output from said shake amount detecting means;

expected shake amount determining means for determining an expected amount of shaking of a looser reference than said minimum value of said amount of shaking stored in said minimum value storage means based on said minimum value;

timer means for measuring time from generation of said shutter release signal from said shutter timing generating means;

comparator means for comparing an output of said timer means with said maximum wait time determined by said maximum wait time determining means;

multiplexer means for receiving an output of said comparator means, outputting said expected amount of shaking determined by said expected shake amount determining means until said maximum wait time elapses, and outputting said allowable amount of shaking determined by said allowable shake amount determining mean after said maximum wait time elapses; and

shutter enable signal output means for comparing an output of said shake amount detecting means with an output of said multiplexer means and outputting said shutter enable signal when a comparison result indicates a predetermined relationship.

6. An exposure control apparatus according to claim 5, wherein said expected shake amount determining means acquires said expected amount of shaking by multiplying said minimum value of said amount of shaking by a constant.

7. An exposure control apparatus according to claim 5, further comprising focus distance detecting means for detecting a focus distance of a zoom lens of said camera, and wherein said maximum wait time determining means determines said maximum wait time using said focus distance detected by said focus distance detecting means in addition to said shutter speed, and said allowable shake amount determining means determines said allowable amount of shaking using said focus distance detected by said focus distance detecting means in addition to said shutter speed.

8. An exposure control apparatus for a camera comprising:

shake amount detecting means for detecting amount of shaking of a camera for each sampling time interval shorter than a hand shaking cycle;

shutter-speed determining means for determining a shutter speed concerning an opening of a shutter of a camera;

compensation means for compensating for said amount of shaking detected by said shake amount detecting means with said shutter speed determined by said shutter-speed determining means;

storage means for storing a shake compensation value output from said compensation means;

prediction means for predicting a total amount of shaking during exposure of a film loaded in said camera by opening of said shutter from a current shake compensation value compensated by said compensation means and a previous shake compensation value stored in said storage means, every time said shake amount detecting means detects said amount of shaking; and

discriminating means for discriminating whether or not said exposure should be started based on said total amount of shaking acquired by said prediction means, in response to a shutter release signal to prepare for beginning of said exposure.

9. An exposure control apparatus according to claim 8, wherein said compensation means divides said shutter speed by said sampling time and computes a product of said amount of shaking and a result of the division.

10. An exposure control apparatus according to claim 8, wherein said discriminating means makes discrimination in light of a shutter time lage from the beginning of said shutter opening to the beginning of actual exposure.

11. An exposure control apparatus for a camera comprising:

shake amount detecting means for detecting amount of shaking of a camera for each sampling time interval shorter than a hand shaking cycle;

storage means for storing a shake compensation value output from said shake amount detecting means;

prediction means for predicting an amount of shaking from a current amount of shaking and a previous amount of shaking stored in said storage means, every time said shake amount detecting means detects said amount of shaking;

shutter-speed determining means for determining a shutter speed concerning an opening of a shutter of a camera;

compensation means for compensating for said amount of shaking predicted by said prediction means with said shutter speed determined by said shutter-speed determining means to acquire a total amount of shaking during opening of said shutter; and

discriminating means for discriminating whether or not exposure of a film loaded in said camera should be started based on said total amount of shaking acquired by said prediction means, in response to a shutter release signal to prepare for a shutter opening operation.

12. An exposure control apparatus for a camera comprising:

shake amount detecting means for detecting amount of shaking of a camera for each sampling time interval shorter than a hand shaking cycle;

storage means for storing a shake compensation value output from said shake amount detecting means;

prediction means for predicting an amount of shaking from a current amount of shaking and a previous amount of shaking stored in said storage means, every time said shake amount detecting means detects said amount of shaking;

shutter-speed determining means for determining a shutter speed concerning an opening of a shutter of a camera; and

discriminating means for comparing an amount of shaking output from said prediction means with a predetermined value determined by said shutter speed determined by said shutter-speed determining means in response to a shutter release signal to prepare for a shutter opening operation to thereby discriminate whether or not exposure of a film loaded in said camera should be started.

13. An exposure control apparatus for a camera for starting an exposing operation with an exposure time based on at least a brightness of an object to be picked up and a sensitivity of a film in response to a release signal from a release operation member, comprising:

output means for outputting information about said exposure time;

detecting means for repeatedly detecting an amount of shaking of said camera in a predetermined detection interval;

processing means for repeatedly detecting an amount of shaking of said camera in a predetermined detection interval;

processing means for processing said amount of shaking detected by said detecting means based on said exposure time information from said output means;

storage means for repeatedly storing an output value of said processing means;

prediction means for predicting an amount of shaking in said exposure time from a currently processed output value from said processing means and a previously processed value stored in said storage means in a case where said exposing operation is started after a predetermined period of time; and

determining means for determining whether or not said exposing operation should be started after said predetermined period of time based on an output of said prediction means.

14. An exposure control apparatus according to claim 13, wherein said processing means performs a computation given below:

space="preserve" listing-type="equation">m×

S/Δ

t

where m is said amount of shaking detected by said detecting means, s is said exposure time information from said output means, and Δ

t is said shake detection interval in said detecting means.

15. An exposure control apparatus according to claim 13, wherein said prediction means predicts said amount of shaking by a fuzzy prediction.

16. An exposure control apparatus according to claim 13, wherein said determining means permits said exposing operating to be started when said amount of shaking predicted by said prediction means becomes equal to or less than a predetermined allowable amount.

17. An exposure control apparatus for a camera for detecting an amount of shaking of a camera in response to a release signal from a release operation member, acquiring from said detected amount of shaking a timing at which an influence of shaking on film exposure and starting an exposing operation at said timing, comprising:

exposure time calculating means for acquiring information of an exposure time based on at least a brightness of an object to be picked up and a sensitivity of a film;

detecting means for repeatedly detecting an amount of shaking of said camera in a predetermined detection interval;

processing means for processing said amount of shaking detected by said detecting means based on said exposure time information acquired by said exposure time calculating means;

storage means capable of repeatedly storing a value processed by said processing means;

prediction means for predicting an amount of shaking in said exposure time from a value currently processed in said processing means and a previously processed value stored in said storage means in a case where said exposing operation is started after a predetermined period of time; and

determining means for determining whether or not said exposing operation should be started after said predetermined period of time based on an output of said prediction means, said determining means including an allowable shake amount calculating circuit for calculating an allowable amount of shaking from a focus distance of a lens, a comparator for comparing said allowable amount of shaking with said predicted amount of shaking from said prediction means, and a circuit for outputting a shutter-open enable signal when said predicted amount of shaking is detected to be equal to or small than said allowable amount of shaking in said comparator.

18. An exposure control apparatus according to claim 17, wherein said processing means performs a computation given below:

space="preserve" listing-type="equation">m×

S/Δ

t

where m is said amount of shaking detected by said detecting means, s is said exposure time information from said output means, and Δ

t is said shake detection interval in said detecting means.

19. An exposure control apparatus according to claim 17, wherein said prediction means predicts said amount of shaking by a fuzzy prediction.

20. An exposure control apparatus according to claim 17, wherein said determining means further includes a limit time calculating circuit for acquiring a delay limit time from said focus distance of said lens, a timer circuit for starting measuring time in response to said release signal, a second comparator for comparing an output of said timer circuit with said limit time, and a control circuit for forcibly outputting said shutter-open enable signal when said output of said timer circuit is detected to have exceeded said limit time in said second comparator.

21. An exposure control apparatus according to claim 17, wherein said determining means further includes second storage means for storing a minimum value of said predicted amount of shaking output from said prediction means, an expected shake amount calculating circuit for acquiring an expected amount of shaking greater by a predetermined amount than said minimum value of said predicted amount of shaking from am output of said second storage means, a limit time calculating circuit for acquiring a delay limit time from said focus distance of said lens, a timer circuit for starting measuring time in response to said release signal, a second comparator for comparing an output of said timer circuit with said limit time, and a replacing circuit for replacing said allowable amount of shaking in said first comparator with said expected amount of shaking when said output of said timer circuit is detected to have exceeded said limit time in said second comparator.

22. An exposure control apparatus for a camera for detecting an amount of shaking of a camera in response to a release signal from a release operation member, acquiring from said detected amount of shaking a timing at which an influence of shaking on film exposure and starting an exposing operation at said timing, comprising:

exposure time calculating means for acquiring an exposure time based on at least a brightness of an object to be picked up and a sensitivity of a film;

detecting means for repeatedly detecting an amount of shaking of said camera in a predetermined detection interval;

storage means capable of repeatedly storing a value detected by said detecting means;

prediction means for predicting an amount of shaking in said exposure time from a value currently detected by said detecting means and a previously detected value stored in said storage means in a case where said exposing operation is started after a predetermined period of time; and

determining means for determining whether or not said exposing operation should be started after said predetermined period of time based on an output of said prediction means.

23. An exposure control apparatus according to claim 22, wherein said prediction means predicts said amount of shaking by a fuzzy prediction.

24. An exposure control apparatus according to claim 22, wherein said determining means includes an allowable shake amount calculating circuit for calculating an allowable amount of shaking from a focus distance of a lens and information of said exposure time, a comparator for comparing said allowable amount of shaking with said predicted amount of shaking from said prediction means, and a circuit for outputting a shutter-open enable signal when said predicted amount of shaking is detected to be equal to or small than said allowable amount of shaking in said comparator.

25. A shake amount predicting apparatus for detecting an amount of shaking of a camera in response to a release signal from a release operation member, and predicting an amount of shaking in an exposure time from said detected amount of shaking in a case where an exposing operation is started after a predetermined period of time, comprising:

exposure time calculating means for acquiring an exposure time based on at least a brightness of an object to be picked up and a sensitivity of a film;

detecting means for detecting an amount of shaking of said camera at least twice in a predetermined detection interval;

processing means for processing said amount of shaking detected by said detecting means based on said exposure time;

storage means capable of storing a value processed by said processing means; and

prediction means for predicting an amount of shaking in said exposure time from a value currently processed in said processing means and a previously processed value stored in said storage means in a case where said exposing operation is started after a predetermined period of time.

26. A shake amount predicting apparatus according to claim 25, wherein said processing means performs a computation given below:

space="preserve" listing-type="equation">m×

S/Δ

t

where m is said amount of shaking detected by said detecting means, s is said exposure time information from said output means, and it is said shake detection interval in said detecting means.

27. A shake amount predicting apparatus according to claim 25, wherein said prediction means predicts said amount of shaking by a fuzz prediction.

28. A shake amount predicting apparatus for detecting an amount of shaking of a camera in response to a release signal from a release operation member, and predicting an amount of shaking in an exposure time from said detected amount of shaking in a case where an exposing operation is started after a predetermined period of time, comprising:

exposure time calculating means for acquiring an exposure time based on at least a brightness of an object to be picked up and a sensitivity of a film;

detecting means for detecting an amount of shaking of said camera at least twice in a predetermined detection interval;

storage means capable of storing a value detected by said detecting means; and

prediction means for predicting an amount of shaking in said exposure time from a value currently detected by said detecting means and a previously detected value stored in said storage means in a case where said exposing operation is started after said predetermined period of time.

29. A shake amount predicting apparatus according to claim 28, wherein said prediction means predicts said amount of shaking by a fuzzy prediction.

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

shake amount detecting means for detecting an amount of shaking of said camera at sampling time intervals;

shutter release signal generating means for generating a shutter release signal for commanding an exposing operation to a film loaded in said camera;

minimum value storage means for storing a minimum value of said amount of shaking output from said shake amount detecting means;

allowable shake amount determining means for determining a maximum allowable amount of shaking based on said minimum value of said amount of shaking stored in said minimum value storage means; and

shutter-open enable signal generating means for comparing an output of said shake amount detecting means with an output of said allowable shake amount determining means after said shutter release signal generating means generates said shutter release signal, and outputting a shutter-open enable signal when a result of comparison indicates a predetermined relationship between said output of said shake amount detecting means and said output of said allowable shake amount determining means.

31. An exposure control apparatus according to claim 30, wherein said allowable shake amount determining means determines said maximum allowable amount of shaking by multiplying said a minimum value of said amount of shaking.

32. An exposure control apparatus for detecting an amount of shaking of a camera, obtaining a timing at which an influence of shaking on film exposure decreases, in accordance with said detected amount of shaking, and starting an exposing operation at said timing, comprising:

exposure time determining means for determining an exposure time to a film loaded in said camera by pre-setting or calculation;

detecting means for detecting repeatedly an amount of shaking of said camera at predetermined detection intervals;

storage means capable of storing data of said amount of shaking detected by said detecting means;

prediction means for predicting an amount of shaking occurring in said exposure time in a case where said exposing operation is started after a predetermined period of time, in accordance with a value currently detected by said detecting means and a previously detected value stored in said storage means; and

determining means for determining whether or not said exposing operation should be started after said predetermined period of time in accordance with an output of said prediction means.

33. A shake amount predicting apparatus for detecting an amount of shaking of a camera and predicting an amount of shaking occurring in an exposure time in a case where an exposing operation is started after a predetermined period of time, in accordance with said detected amount of shaking, comprising:

exposure time determining means for determining an exposure time to a film loaded in said camera by pre-setting or calculation;

detecting means for detecting an amount of shaking of said camera at least twice at predetermined detection intervals;

processing means for processing repeatedly said amount of shaking detected by said detecting means based on said exposure time;

storage means capable of storing a value output from said processing means; and

prediction means for predicting an amount of shaking occurring in said exposure time in a case where said exposing operation is started after a predetermined period of time, in accordance with a value currently processed in said processing means and a previously processed value stored in said storage means.

34. A shake amount predicting apparatus for detecting an amount of shaking of a camera, and predicting an amount of shaking occurring in an exposure time in a case where an exposing operation is started after a predetermined period of time, in accordance with a detected amount of shaking, comprising:

detecting means for detecting an amount of shaking of said camera at least twice at predetermined detection intervals;

storage means capable of storing a value detected by said detecting means; and

prediction means for predicting an amount of shaking occurring in said exposure time in accordance with a value currently detected by said detecting means and a previously detected value stored in said storage means in a case where said exposing operation is started after said predetermined period of time.

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

shake amount detecting means for detecting repeatedly an amount of shaking of said camera at sampling time intervals;

a first release signal generating means for generating a first release signal for commanding a photographing preparation operation;

a second release signal generating means for generating a second release signal for commanding an exposing operation to a film loaded in said camera;

allowable shake amount determining means for detecting a maximum allowable amount of shaking after the generation of said first release signal after said first release signal generating means generates said first release signal and before said second release signal generating means generates said second release signal in accordance with said amount of shaking detected by said shake amount detecting means; and

shutter-open enable signal generating means for comparing an output of said shake amount detecting means with an output of said allowable shake amount determining means after said second release signal generating means generates a second release signal, and outputting a shutter-open enable signal when a result of comparison indicates a predetermined relationship between said output of said shake amount detecting means and said output of said allowable shake amount determining means.