Movie camera having still picture photographing function and method of photographing still picture therewith

• US 5,382,974 A
• Filed: 10/01/1993
• Issued: 01/17/1995
• Est. Priority Date: 04/18/1991
• Status: Expired due to Term

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Tsugita, Makoto, Soeda, Haruo
• Primary Examiner(s): Mancuso, Joseph
• Assistant Examiner(s): Ho, Tuan V.
• Application Number:
  US08/107,973
• Time in Patent Office: 473 Days
• Field of Search: 348/221, 348/220, 348/239, 348/207, 348/228, 358/906, 358/903, 358/335, 358/341, 358/342, 358/343
• US Class Current: 348/221.1
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof

Abstract

A movie camera and a method of photographing a still with the movie camera is provided wherein the movie camera is of a type wherein a motionless picture or still can be photographed during a movie photography operation and when the illumination falling on an object is a predetermined value or less at the start in the photography of the still during the movie photography operation, stroboscopic flashes of light are produced from a strobe device to enable still photography. The movie camera basically includes a CCD for converting image information corresponding to light incident on a lens into an electric signal, a movie-photography triggering signal generating device for starting a movie photography operation, a still-photography triggering signal generating device for starting a still photography operation, and an electronic shutter speed switching device for changing over the shutter speed to a desired shutter speed faster than that at the time of the movie photography when the still-photography triggering signal generating device is activated to start the still photography operation during the movie photography operation. According to the above construction, the strobe device automatically produces flashing light in synchronism with the shutter timing of a high-speed operated shutter for thereby enabling instant photography of a desired motionless picture.

Claims

1. A movie camera capable of producing a still photograph during a movie-photography operation, said camera comprising:

strobe means for illuminating objects to be photographed with stroboscopic flashes of light;

solid-state image sensing means for electrically converting image information from light incident thereon into movie and still image signals;

gain control means for controlling the gain of image signals output from the solid-state image sensing means;

video processing and recording means for processing said image signals into movie and still video signals and recording said video signals on the same video recording medium;

movie-photography initiation means for starting a movie-photography operation in which a plurality of movie video signals are successively recorded on the video signal recording medium;

still-photography initiation means for starting a still-photography operation in which still-photography video signals are recorded on the video recording medium, said still-photography initiation means being capable of starting the still-photography operation during the movie-photography operation;

electronic shutter speed control means for setting the shutter speed of said solid-state image sensing means to desired values to control exposure times during the movie and still photography operations;

shutter speed switching means responsive to the starting of a still-photography operation by the still-photography initiation means for automatically changing the shutter speed set by the shutter speed control means to a shutter speed that is faster than the shutter speed set for a concurrently proceeding movie-photography operation to thereby decrease the exposure time of still image signals in the solid-state image sensing means as compared to exposure times of the movie image signals;

still-photography controller means for determining the gains set by said gain control means and for instructing said gain control means to increase the gain of output image signals to gains which compensate for the decrease in exposure time caused by the increased shutter speed during the still-photography operation, and for activating the strobe means to illuminate the objects with stroboscopic flashes of light to supplement the effects of the increased gain in order to further compensate for the decrease in exposure time; and

means for automatically returning the movie camera to the movie-photography operation upon completion of the still-photography operation;

whereby the movie-photography operation is not perceptively interrupted by the still-photography operation.

2. A movie camera according to claim 1, wherein said solid-state image sensing means comprises a CCD.

3. A movie camera according to claim 2, wherein said shutter speed switching means comprises:

a CCD drive circuit for energizing said CCD; and

an SSG circuit for supplying a vertical synchronizing signal to said CCD drive circuit;

said shutter speed switching means supplying a sweep signal to said CCD drive circuit via said SSG circuit to cause image signal charges stored in said CCD to be discharged for a predetermined period of time, to thereby set the shutter speed to said faster shutter speed.

4. A movie camera according to claim 1, wherein said strobe means comprises:

a charging unit for charging a battery;

a strobe control unit for controlling said strobe means; and

a stroboscopic flashing light producing unit for producing stroboscopic flashes of light powered by said battery;

said still-photography controller means being activated to supply a desired signal to said strobe control unit thereby illuminating the object with the stroboscopic flashes of light.

5. A movie camera capable of producing a still photograph during a movie-photography operation, said camera comprising:

strobe means for illuminating objects to be photographed with stroboscopic flashes of light;

solid-state image sensing means for electrically converting image information from light incident thereon into movie and still image signals;

gain control means for controlling the gain of image signals output from the solid-state image sensing means;

video processing and recording means for processing said image signals into movie and still video signals and recording said video signals on the same video recording medium;

movie-photography initiation means for starting a movie-photography operation in which a plurality of movie video signals are successively recorded on the video signal recording medium;

still-photography initiation means for starting a still-photography operation in which still-photography video signals are recorded on the video recording medium, said still-photography initiation means being capable of starting the still-photography operation during the movie photography operation;

electronic shutter speed control means for setting the shutter speed of said solid-state image sensing means to desired values to control exposure times during the movie and still photography operations;

shutter speed switching means responsive to the starting of a still-photography operation by the still-photography initiation means for automatically changing the shutter speed set by the shutter speed control means to a shutter speed that is faster than the shutter speed set for a concurrently proceeding movie-photography-operation to thereby decrease the exposure time of still image signals in the solid-state image sensing means as compared to exposure times of the movie image signals;

still-photography controller means for instructing said gain control means to increase the gain of output image signals to gains which compensate for the decrease in exposure time caused by the increased shutter speed during the still-photography operation;

object illumination sensing means for determining whether or not the illumination falling on said object as sensed by the solid-state image sensing means has reached a predetermined value;

strobe controller means for activating said strobe means during said still-photography operation to generate said stroboscopic flashes of light when the illumination falling on the object is less than said predetermined value; and

means for automatically returning the movie camera to the movie-photography operation upon completion of the still-photography operation;

whereby the movie-photography operation is not perceptively interrupted by the still-photography operation.

6. A movie camera according to claim 5 wherein said solid-state image sensing means comprises a CCD.

7. A movie camera according to claim 6 wherein said shutter speed switching means comprises:

a CCD drive circuit for energizing said CCD; and

an SSG circuit for supplying a vertical synchronizing signal to said CCD drive circuit;

said shutter speed switching means supplying a sweep signal to said CCD drive circuit via said SSG circuit to cause image signal charges stored in said CCD to be discharged for a predetermined period of time, to thereby set the shutter speed to said faster shutter speed.

8. A movie camera according to claim 5, wherein said object illumination detection means comprises:

iris position detector means for determining the position of an iris in the movie camera which defines the size of an iris opening, and generating a position signal indicative of the size of the iris opening; and

means for determining from said position signal and the increased gain set by the gain control means if the illumination falling on the object as sensed by the solid-state image sensing means has reached said predetermined value.

9. A movie camera according to claim 5 wherein said strobe means comprises:

a charging unit for charging a battery;

a strobe control unit for controlling said strobe means; and

a stroboscopic flashing light producing unit for producing stroboscopic flashes of light powered by said battery;

said still-photography controller means being activated to supply a desired signal to said strobe control unit thereby illuminating the object with the stroboscopic flashes of light.

10. A movie camera capable of producing a still photograph during a movie-photography operation, said camera comprising:

solid-state image sensing means for electrically converting image information from light incident thereon into movie and still image signals;

gain control means for controlling the gain of image signals output from the solid-state image sensing means;

video processing and recording means for processing said image signals into movie and still video signals and recording said video signals on the same video recording medium;

movie-photography initiation means for starting a movie-photography operation in which a plurality of movie video signals are successively recorded on the video signal recording medium;

still-photography initiation means for starting a still-photography operation in which still-photography video signals are recorded on the video recording medium, said still-photography initiation means being capable of starting the still-photography operation during the movie photography operation;

electronic shutter speed control means for setting the shutter speed of said solid-state image sensing means to desired values to control exposure times during the movie and still photography operations;

shutter speed switching means responsive to the starting of a still-photography operation by the still-photography initiation means for automatically changing the shutter speed set by the shutter speed control means to a shutter speed that is faster than the shutter speed set for a concurrently proceeding movie-photography-operation to thereby decrease the exposure time of still image signals in the solid-state image sensing means as compared to exposure times of the movie image signals;

still-photography controller means for determining the gains set by said gain control means and for instructing said gain control means to increase the gain of output image signals to gains which compensate for the decrease in exposure time caused by the increased shutter speed during the still-photography operation;

means for automatically returning the movie camera to the movie-photography operation upon completion of the still-photography operation;

whereby the movie-photography operation is not perceptively interrupted by the still-photography operation.

11. A movie camera according to claim 10 wherein said solid-state image sensing means comprises a CCD.

12. A movie camera according to claim 10, wherein said shutter speed switching means comprises:

a CCD drive circuit for energizing said CCD; and

an SSG circuit for supplying a vertical synchronizing signal to said CCD drive circuit;

said shutter speed switching means supplying a sweep signal to said CCD drive circuit via said SSG circuit to cause image signal charges stored in said CCD to be discharged for a predetermined period of time, to thereby set the shutter speed to said faster shutter speed.

13. A movie camera capable of producing a still photograph during a movie-photography operation, said camera comprising:

strobe means for illuminating objects to be photographed with stroboscopic flashes of light;

solid-state image sensing means for electrically converting image information from light incident thereon into movie and still image signals;

video processing and recording means for processing said image signals into movie and still video signals and recording said video signals on the same video recording medium;

movie-photography initiation means for starting a movie-photography operation in which a plurality of movie video signals are successively recorded on the video signal recording medium;

still-photography initiation means for starting a still-photography operation in which still-photography video signals are recorded on the video recording medium, said still-photography initiation means being capable of starting the still-photography operation during the movie photography operation;

electronic shutter speed control means for setting the shutter speed of said solid-state image sensing means to desired values to control exposure times during the movie and still photography operations;

shutter speed switching means responsive to the starting of a still-photography operation by the still-photography initiation means for automatically changing the shutter speed set by the shutter speed control means to a shutter speed that is faster than the shutter speed set for a concurrently proceeding movie-photography-operation to thereby decrease the exposure time of still image signals in the solid-state image sensing means as compared to exposure times of the movie image signals;

still-photography controller means for activating the strobe means to illuminate the objects with stroboscopic flashes of light in order to compensate for the decrease in exposure time; and

means for automatically returning the movie camera to the movie-photography operation upon completion of the still-photography operation;

whereby the movie-photography operation is not perceptively interrupted by the still-photography operation.

14. A movie camera according to claim 13 wherein said shutter speed switching means comprises:

a CCD drive circuit for energizing said CCD; and

an SSG circuit for supplying a vertical synchronizing signal to said CCD drive circuit;

said shutter speed switching means supplying a sweeping signal to said CCD drive circuit via said SSG circuit to cause image signal charges stored in said CCD to be discharged for a predetermined period of time, to thereby set the shutter speed to said faster shutter speed.

15. A movie camera according to claim 14 wherein said strobe means comprises:

a charging unit for charging a battery;

a strobe control unit for controlling said strobe means; and

a stroboscopic flashing light producing unit for producing stroboscopic flashes of light powered by said battery;

said still-photography controller means being activated to supply a desired signal to said strobe control unit and thereby illuminating the object with the stroboscopic flashes of light.

16. A movie camera according to claim 13 wherein said solid-state image sensing means comprises a CCD.

17. A movie camera according to claim 16 wherein said shutter speed switching means comprises:

a CCD drive circuit for energizing said CCD; and

an SSG circuit for supplying a vertical synchronizing signal to said CCD drive circuit;

said shutter speed switching means supplying a sweep signal to said CCD drive circuit via said SSG circuit to cause image signal charges stored in said CCD to be discharged for a predetermined period of time, to thereby set the shutter speed to said faster shutter speed.

18. A method of producing a still photograph with a movie camera having a still photographing function, comprising the steps of:

(a) energizing still-photography triggering signal generating means so as to start a still photography operation;

(b) reading image information of an object as an image signal by a CCD and determining by a still controller the gain of an AGC circuit obtained by amplifying said image signal with said AGC circuit;

(c) recording said image signal on a video signal recording medium by video processing and recording means;

(d) activating said still controller in a manner for determining whether a strobe switch has been brought to an on or off state, setting the gain of said AGC circuit determined in step (b) to a predetermined gain and setting the electronic shutter speed to a predetermined electronic shutter speed for photographing the still photograph;

(e) processing and recording the still photograph from a still shot image signal immediately after the last movie image signal is generated during the movie photography operation on said video signal recording medium by said video processing and recording means, which records both the movie photography and the still photograph, by setting an exposure time of an electronic shutter shorter than that for the movie photography operation by controlling an accumulation time in a solid-state imaging element and adjusting the gain of the movie camera to compensate for shortage of said exposure time;

(f) flashing a strobe light onto the object when said gain has been maximized during the movie photography operation in order to supplement the effects of the adjusted gain; and

(g) de-energizing said still-photography triggering signal generating means after said still photography has been completed, for thereby returning to the movie photography operation without a perceptible interruption of the movie photography operation.

19. A method according to claim 18, wherein step (d) further includes the steps of determining whether the gain of said AGC circuit is of 0 dB and said strobe switch has been brought to the off state, and if the gain of said AGC circuit is of 0 dB and said strobe switch has been brought to the off state, then activating said still controller to increase the gain of said AGC circuit to a given value and setting said electronic shutter speed to a first given electronic shutter speed.

20. A method according to claim 18, wherein step (d) further includes the steps of determining whether the gain of said AGC circuit fails between 0 dB and 3 dB and said strobe switch has been brought to the off state, and if the gain of said AGC circuit galls between 0 dB and 3 dB and said strobe switch has been brought to the off state, then activating said still controller to increase the gain of said AGC circuit to a given value and setting the electronic shutter speed to a second given electronic shutter speed for thereby producing a still photograph.

21. A method according to claim 18, wherein step (d) further includes the steps of determining whether the gain of said AGC circuit falls between 3 dB and 6 dB and said strobe switch has been brought to the off state, and if the gain of said AGC circuit falls between 3 dB and 6 dB and said strobe switch has been brought to the off state, then activating said still controller to increase the gain of said AGC circuit to a given value and setting the electronic shutter speed to a third given electronic shutter speed for thereby producing a still photograph.

22. A method according to claim 18, wherein step (d) further includes the steps of determining whether the gain of said AGC circuit is more than or equal to 6 dB and said strobe switch has been brought to the off state, and if the gain of said AGC circuit is more than or equal to 6 dB and said strobe switch has been brought to the off state, then activating said still controller to set the electronic shutter speed to a fourth given electronic shutter speed for thereby producing a still photograph.

23. A method according to claim 18, wherein step (d) further includes the steps of determining whether the gain of said AGC circuit is greater than or equal to 0 dB and said strobe switch has been brought to the on state, and if the gain of said AGC circuit is greater than or equal to 0 dB and said strobe switch has been brought to the on state, then activating said still controller to set the gain of said AGC circuit to 0 dB and setting the electronic shutter speed to the first given electronic shutter speed for thereby producing a still photograph in a strobe mode.

24. A method according to claim 23, wherein said strobe mode comprises the steps of:

(1) supplying distance information to an object to said still controller based on AF information from a focus position detector circuit;

(2) generating a desired signal from said still controller to set the gain of said AGC circuit to a first given value when said distance information supplied to said still controller in said step (1) is less than or equal to 8.5 m and supplying a desired signal to a strobe control unit from said still controller so as to produce stroboscopic flashes of light from a stroboscopic flashing light producing unit for thereby producing a still photograph;

(3) generating a desired signal from said still controller to set the gain of said AGC circuit to a second given value larger than said first given value when said distance information supplied to said still controller in said step (1) falls between 8.5 m and 12 m and supplying a desired signal to said strobe control unit from said still controller so as to produce stroboscopic flashes of light from said stroboscopic flashing light producing unit for thereby producing a still photograph;

(4) generating a desired signal from said still controller to set the gain of said AGC circuit to a third given value larger than said second given value when said distance information supplied to said still controller in said step (1) falls between 12 m and 17 m and supplying a desired signal to said strobe control unit from said still controller so as to produce stroboscopic flashes of light from said stroboscopic flashing light producing unit for thereby producing a still photograph; and

(5) generating a desired signal from said still controller to set the gain of said AGC circuit to a fourth given value larger than said third given value when said distance information supplied to said still controller in said step (1) is more than or equal to 17 m and supplying a desired signal to said strobe control unit from said still controller so as to produce stroboscopic flashes of light from said stroboscopic flashing light producing unit for thereby producing a still photograph.

25. A method of producing a still photograph with a movie camera having a still photographing function, comprising the steps of:

(a) recording an image signal on a recording medium by a video head;

(b) energizing still-photography triggering signal generating means during a movie photography operation so as to start a still photography operation;

(c) supplying a desired signal to a CCD drive circuit from a still controller through an SSG circuit so as to set the electronic shutter speed to a given electronic shutter speed;

(d) inputting iris information of an object from an iris position detector used to detect the opening and closing conditions of an iris and gain information from an AGC circuit to said still controller and causing said still controller to determine based on said iris and gain information whether or not the illumination falling on the object falls within a minimum allowable value;

(e) causing said still controller to set up given white balance corresponding to strobe photography and supplying a signal indicative of the set-up white balance information to a balance control circuit if step (d) determines that the illumination falling on the object is within said minimum allowable value;

(f) activating said still controller in a manner to supply a sweep signal to said CCD drive circuit via said SSG circuit in synchronism with a vertical synchronizing signal of 1/60 second output from said SSG circuit;

(g) storing signal charges in said CCD according to the electronic shutter speed when said sweep signal is input to said CCD drive circuit and activating said still controller so as to supply a desired signal to a strobe control unit in synchronism with the timing of the electronic shutter speed for thereby energizing said strobe device in unison with the electronic shutter timing at the time of the still photography so as to enable said strobe device to automatically produce stroboscopic flashes of light;

(h) recording the still photograph on said recording medium by said video head in response to a still photography trigger after processing said image signal as in the movie photography operation by setting an exposure time of an electronic shutter shorter than that for the movie photography operation by controlling an accumulation time in a solid-state imaging element and adjusting the gain of the movie camera to compensate for shortage of said exposure time;

(i) flashing said strobe device when said gain has been maximized during the movie photography operation in order to supplement the effects of the adjusted gain; and

(j) automatically returning the movie camera to the movie photography operation after said still photography trigger is effected for recording the still photography at step (h).

26. A method of producing a still photograph with a movie camera during a movie-photography operation, the steps of:

converting image information from light incident on an image sensing means into movie and still image signals;

processing and recording said image signals into movie and still video signals and recording said video signals on the same video recording medium;

starting a movie-photography operation in which a plurality of movie video signals are successively recorded on the video recording medium,

starting a still-photography operation in which still-photography video signals are recorded on the video recording medium, said still-photography operation being started during the movie-photography operation;

setting the shutter speed of said solid-state image sensing means to desired values to control exposure times during the movie and still photography operations;

automatically changing in response to starting of the still-photography operation the shutter speed to one that is faster than the shutter speed set for a concurrently proceeding movie-photography operation to thereby decrease the exposure time of still image signals in the image sensing means as compared to exposure times of the movie image signals;

determining gains set by a gain control means on image signals output from said image sensing means during the movie-photography operation; and

adjusting the gain of output image signals to gains which compensate for the decrease in exposure time caused by the increased shutter speed during the still-photography operation;

illuminating the objects with stroboscopic flashes of light to supplement the effects of the adjusted gain in order to further compensate for the decrease in exposure time; and

automatically returning the movie camera to the movie-photography operation upon completion of the still-photography operation;

whereby the movie-photography operation is not perceptively interrupted by the still-photography operation.

27. A method of producing a still photograph with a movie camera during a movie-photography operation, the steps of:

converting image information from light incident on an image sensing means into movie and still image signals;

processing and recording said image signals into movie and still video signals and recording said video signals on the same video recording medium;

starting a movie-photography operation in which a plurality of movie video signals are successively recorded on the video recording medium,

starting a still-photography operation in which still-photography video signals are recorded on the video recording medium, said still-photography operation being started during the movie-photography operation;

setting the shutter speed of said solid-state image sensing means to desired values to control exposure times during the movie and still photography operations;

automatically changing in response to starting of the still-photography operation the shutter speed to one that is faster than the shutter speed set for a concurrently proceeding movie-photography operation to thereby decrease the exposure time of still image signals in the image sensing means as compared to exposure times of the movie image signals;

determining gains set by a gain control means on image signals output from said image sensing means during the movie-photography operation; and

adjusting the gain of output image signals to gains which compensate for the decrease in exposure time caused by the increased shutter speed during the still-photography operation; and

automatically returning the movie camera to the movie-photography operation upon completion of the still-photography operation;

whereby the movie-photography operation is not perceptively interrupted by the still-photography operation.

28. A method of producing a still photograph with a movie camera during a movie-photography operation, the steps of:

converting image information from light incident on an image sensing means into movie and still image signals;

processing and recording said image signals into movie and still video signals and recording said video signals on the same video recording medium;

starting a movie-photography operation in which a plurality of movie video signals are successively recorded on the video recording medium,

starting a still-photography operation in which still-photography video signals are recorded on the video recording medium, said still-photography operation being started during the movie-photography operation;

setting the shutter speed of said solid-state image sensing means to desired values to control exposure times during the movie and still photography operations;

automatically changing in response to starting of the still-photography operation the shutter speed to one that is faster than the shutter speed set for a concurrently proceeding movie-photography operation to thereby decrease the exposure time of still image signals in the image sensing means as compared to exposure times of the movie image signals;

illuminating the objects with stroboscopic flashes of light to supplement the effects of the shutter speed change in order to further compensate for the decrease in exposure time; and

automatically returning the movie camera to the movie-photography operation upon completion of the still-photography operation;

whereby the movie-photography operation is not perceptively interrupted by the still-photography operation.