Method and apparatus using weighted range signal for controlling photographic functions

• US 4,357,083 A
• Filed: 10/06/1980
• Issued: 11/02/1982
• Est. Priority Date: 10/06/1980
• Status: Expired due to Term

• Current Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Johnson, Bruce K., Whiteside, George D.
• Primary Examiner(s): Rubinson, G. Z.
• Assistant Examiner(s): Schreyer, S. D.
• Application Number:
  US06/193,891
• Time in Patent Office: 757 Days
• Field of Search: 354/22, 354/23 R, 354/25, 354/27, 354/29, 354/30, 354/33-35, 354/59, 354/60 F, 354/67, 354/127, 354/128, 354/163, 354/195, 354/298, 356/225
• US Class Current: 396/106
• CPC Class Codes: G02B 7/32 using active means, e.g. light emitter including both an active and a passive focus detecting device G02B7/285; using ultrasound G02B7/40
• 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

Abstract

Method and apparatus are disclosed which direct a preliminary pulse of radiation from a selectively energizable light source toward a subject, and a device for evaluating the amplitude of the reflected pulse of radiation therefrom so as to determine a weighted range signal as a function of the amplitude of generally non-visible radiation frequencies selected for reducing the non-uniformity in reflectivity values of reflected visible radiation in the scene, which weighted range signal includes a reflectivity factor and a range factor. The reflectivity factor, which detracts from the range factor for focusing, significantly enhances exposure control under certain scene lighting conditions.

Claims

1. A camera comprising:

a lens assembly for directing image-carrying light rays along a given path from a photographic scene to a focal plane;

a shutter system for controlling the transmission of light from the scene to the focal plane so as to define an exposure interval during an evaluation period;

means for first actuating a light source, configured to produce radiation which essentially comprises simultaneously of both visible and non-visible electromagnetic frequencies, to direct a first pulse of said radiation of given intensity toward a subject in the scene prior to commencement of or in the early stages of said exposure interval to evaluate the subject including its distance from the camera, and for subsequently actuating the same source to direct a second pulse of said radiation toward the scene during said exposure interval to artificially illuminate the subject of photographic recording during exposure;

means for evaluating the intensity of light from the scene during the first pulse of illumination, said evaluating means including means for reducing the contribution to said evaluation of the visible frequencies relative to that of the non-visible frequencies from said scene responsive to said first pulse; and

means responsive to the evaluated intensity of the scene including the reflection of the first pulse for controlling at least one photograhic function, whereby non-visible frequencies from the source are utilized for subject evaluation and subsequent photographic control, and the visible frequencies from the same source are utilized for scene illumination for photographic recording during the exposure interval.

2. The camera of claim 1 wherein said means for controlling at least one photographic function includes means for controlling said camera during the second actuation thereof to provide a predetermined contribution of the illumination to the exposure.

3. A camera comprising:

a lens assembly for directing image-carrying light rays along a given path from a photographic scene to a focal plane;

a shutter system for controlling the transmission of light from the scene to the focal plane so as to define an exposure interval during an evaluation period;

means for first actuating a light source, configured to produce radiation which essentially comprises simultaneously of both visible and non-visible electromagnetic frequencies, to direct a first pulse of said radiation of given intensity toward a subject in the scene prior to commencement of or in the early stages of said exposure interval to evaluate the subject including its distance from the camera, and for subsequently actuating the same source to direct a second pulse of said radiation toward the scene during said exposure interval to artificially illuminate the subject for photographic recording during exposure;

means for evaluating the intensity of primarily non-visible light from the scene during the first pulse of illumination; and

means responsive to the evaluated intensity of the scene resulting from reflection of the first pulse for controlling at least one photographic function, whereby non-visible frequencies from the source are utilized for subject evaluation and subsequent photographic control, and the visible frequencies from the same source are utilized for scene illumination for photographic recording during the exposure interval.

4. The camera of claim 3 wherein said means for evaluating the reflected intensity from the first pulse comprises means for the evaluation of essentially infrared frequencies.

5. The camera of claim 3 wherein said means for controlling at least one photographic function includes means for controlling the operation of the source during the second actuation thereof to provide a predetermined contribution of the artifical illumination to the exposure.

6. The camera of claim 3 wherein said shutter system includes blade means operative for providing selected aperture values, and said means for controlling at least one photographic function includes means for coordinating operation of said blade means with the second actuation of the source to provide a predetermined aperture value during the second pulse in accordance with said evaluated intensity of said first pulse.

7. The camera of claim 3 wherein said means for controlling at least one photographic function includes means for controlling said camera during the second actuation thereof to provide a predetermined contribution of the illumination to the exposure.

8. The camera of claim 3 wherein said actuating means produces the first and second pulses of radiation such that regardless of subject range the second pulse is fired so that it is generally visually indistinguishable from the first pulse.

9. A camera system comprising:

a lens assembly for directing image-carrying light rays along a given path from a photographic scene to a focal plane;

a shutter system for controlling the transmission of light from the scene to the focal plane so as to define an exposure interval during an evaluation period;

an actuatable light source operative to produce radiation which essentially comprises simulataneously of both artificial visible and non-visible electromagnetic radiation frequencies;

means for first actuating said light source to direct a first pulse of said radiation of given intensity toward a subject in the scene prior to commencement of or in the early stages of said exposure interval to evaluate the subject including its distance from the camera system, and to subsequently actuate said light source to direct a second pulse of said radiation toward the scene during said exposure interval to illuminate the subject for photographic recording during exposure;

means for evaluating the intensity of primarily non-visible frequencies of the scene during said first pulse of radiation; and

means responsive to the evaluated intensity resulting from the scene including said first pulse for controlling at least one camera function of said system, whereby said non-visible frequencies from said source is utilized for subject evaluation and subsequent camera system control, and said visible light from the same source is utilized for scene illumination for photographic recording during the exposure interval.

10. The camera system of claim 9 wherein said means for evaluating the reflected intensity from said first pulse comprises means for the evaluation of infrared frequencies.

11. The camera system of claim 9 wherein said means for controlling said system includes means for controlling said camera system during the second actuation of said source to provide a predetermined contribution of the artificial illumination to the exposure.

12. The camera system of claim 11 wherein said means for controlling at least one camera system function includes means for controlling said light source during the second actuation thereof to provide a predetermined contribution of the artificial illumination to the photographic recording during the exposure interval.

13. Photographic apparatus comprising:

an actuatable light source operative to produce pulses of radiation which essentially comprises simultaneously of both visible and non-visible electromagnetic frequencies;

a shutter system for controlling the transmission of scene light to the focal plane so as to define an exposure interval during an evaluation period;

means responsive to a first signal for actuating said light source to direct a first pulse of said radiation thereof of given intensity toward a subject in a photographic scene prior to commencement of or in the early stages of an exposure interval to evaluate the subject including its distance from the light source and being responsive to a second signal for subsequently actuating said light source to direct a second pulse of frequencies of said radiation toward the scene during an exposure interval to illuminate the subject for photographic recording;

means for evaluating the intensity of primarily non-visible light reflected from the scene during said first pulse; and

means responsive to evaluated intensity resulting from reflection of said first pulse for controlling said light source during the second actuation thereof to provide a selected illumination of the subject during the exposure interval, whereby non-visible frequencies from said source are utilized for subject evaluation and control of the visible light from the same source subsequently utilized for scene illumination for photographic exposure during the exposure interval.

14. The camera of claim 13 wherein said means for evaluating the reflected intensity from said first pulse comprises means for the evaluation of essentially infrared frequencies.

15. A method of determining the object range for providing a photographic exposure at least in part with artificial illumination and with photographic apparatus having means for controlling the transmission of light along an exposure path for defining an exposure interval during an exposure period, ranging means including a source of artificial light actuatable for illuminating the scene essentially simultaneously with both visible and non-visible electromagnetic radiation, means for evaluating the radiation from a photographic scene, and means for actuating said source, the method comprising the steps of:

actuating said source to direct a first pulse of said electromagnetic radiation at a subject in the photographic scene;

evaluating radiation from the scene with the contribution to the evaluation of the visible frequencies being reduced relative to that of the non-visible frequencies radiating from said scene during said first pulse; and

controlling at least one photographic function operative in correspondence with the elevated radiation.

16. The method of claim 15 wherein said step of controlling at least one photographic function comprises the step of controlling the contribution of the source illumination of the source to the exposure during the exposure interval in correspondence with said evaluated amplitude.

17. A method of determining the object range for providing a photographic exposure at least in part with artificial illumination and with photograhic apparatus having means for controlling the transmission of light along an exposure path for defining an exposure interval during an exposure period, ranging means including a source of artificial light actuatable for illuminating the scene essentially simultaneously with both visible and non-visible electromagnetic radiation, means for evaluating the radiation from a photographic scene, and means for actuating said source, the method comprising the steps of:

actuating said source to direct a first pulse of said electromagnetic radiation at a subject in the photographic scene;

evaluating primarily non-visible radiation reflected from the scene by said first pulse; and

controlling at least one photograhic function in correspondence with the evaluated non-visible radiation.

18. A method of determining the object range for providing a photographic exposure at least in part with artificial illumination and with photograhic apparatus having means for controlling the transmission of light along an exposure path for defining an exposure interval during an exposure period, ranging means including a source of artificial light actuatable for illuminating the scene essentially simultaneously with both visible and non-visible electromagnetic radiation, means for evaluating the amplitude of the radiation from a photographic scene, and means for actuating said source, the method comprising the steps of:

actuating said source to direct a first pulse of said electromagnetic radiation at a subject in the photographic scene;

evaluating the amplitude of essentially only non-visible radiation reflected from the scene by said first pulse;

controlling at least one photographic function operative during the exposure period in correspondence with the evaluated amplitude of said non-visible radiation;

initiating the exposure interval; and

again actuating said source to produce a second pulse of said electromagnetic radiation to illuminate the subject during the exposure period.

19. The method of claim 18 wherein said step of evaluating essentially only non-visible radiation comprises the step of evaluating infrared frequencies.

20. The method of claim 18 wherein said step of controlling at least one photographic function comprises the step of controlling the contribution of the source illumination of the source to the exposure during the exposure interval in correspondence with said evaluated amplitude.

21. The method of claim 18 wherein the time between the steps of first and second actuations of said source is sufficiently short such that the pulses are visually indistinguishable from each other as separate pulses.

22. The method of claim 18 further comprising the step of also evaluating non-visible radiation during said second pulse.

23. A camera comprising:

a lens assembly for directing image-carrying light rays along a given path from a photographic scene to a focal plane;

a shutter system for controlling the transmission of light from the scene to the focal plane so as to define an exposure interval during an evaluation period;

means for first actuating a light source, configured to produce both visible and non-visible electromagnetic frequencies, to direct a first pulse of radiation of given intensity toward a subject in the scene prior to commencement of or in the early stages of said exposure interval to evaluate the subject including its distance from the camera, and for subsequently actuating the same source to direct a second pulse of radiation toward the scene during said exposure interval to artificially illuminate the subject for photographic recording during exposure;

means for evaluating the intensity of light from the scene during the first pulse of illumination, said evaluating means including means for reducing the contribution to said evaluation of the visible frequencies relative to that of the non-visible frequencies from said scene responsive to said first pulse;

means responsive to the evaluated intensity of the scene including the reflection of the first pulse for controlling at least one photographic function, whereby non-visible frequencies from the source are utilized for subject evaluation and subsequent photographic control, and the visible frequencies from the same source are utilized for scene illumination for photographic recording during the exposure interval; and

said evaluating means includes a photocell sensitive to both visible and non-visible frequencies and means for reducing transmission of visible frequencies to said photocell during the first pulse for determining said scene information and for permitting transmission of visible radiation to said photocell at another time to evaluate scene lighting for the photographic recording during exposure.

24. A camera comprising:

a lens assembly for directing image-carrying light rays along a given path from a photographic scene to a focal plane;

a shutter system for controlling the transmission of light from the scene to the focal plane so as to define an exposure interval during an evaluation period;

means for first actuating a light source, configured to produce both visible and non-visible electromagnetic frequencies, to direct a first pulse of radiation of given intensity toward a subject in the scene prior to commencement of or in the early stages of said exposure interval to evaluate the subject including its distance from the camera, and for subsequently actuating the same source to direct a second pulse of radiation toward the scene during said exposure interval to artificially illuminate the subject for photographic recording during exposure;

means for evaluating the intensity of primarily non-visible light from the scene during the first pulse of illumination;

means responsive to the evaluated intensity of the scene resulting from reflection of the first pulse for controlling at least one photographic function, whereby non-visible frequencies from the source are utilized for subject evaluation and subsequent photographic control, and the visible frequencies from the same source are utilized for scene illumination for photographic recording during the exposure interval; and

said evaluating means includes a photocell sensitive to both visible and non-visible frequencies and means for reducing transmission of visible frequencies to said photocell during the first pulse for determining said scene information and for permitting transmission of visible radiation to said photocell at another time to evaluate scene lighting for the photographic recording during exposure.

25. A camera comprising:

a lens assembly for directing image-carrying light rays along a given path from a photographic scene to a focal plane;

a shutter system for controlling the transmission of light from the scene to the focal plane so as to define an exposure interval during an evaluation period;

means for first actuating a light source, configured to produce both visible and non-visible electromagnetic frequencies, to direct a first pulse of radiation of given intensity toward a subject in the scene prior to commencement of or in the early stages of said exposure interval to evaluate the subject including its distance from the camera, and for subsequently actuating the same source to direct a second pulse of radiation toward the scene during said exposure interval to artificially illuminate the subject for photographic recording during exposure;

means for evaluating the intensity of primarily non-visible light from the scene during the first pulse of illumination;

means responsive to the evaluated intensity of the scene resulting from reflection of the first pulse for controlling at least one photographic function, whereby non-visible frequencies from the source are utilized for subject evaluation and subsequent photographic control, and the visible frequencies from the same source are utilized for scene illumination for photograhic recording during the exposure interval; and

said lens assembly is a variable objective lens assembly, and wherein said means for controlling at least one photographic function includes means for varying said variable objective lens assembly to provide a focal position thereof in accordance with said evaluated intensity of the first pulse.

26. A camera system comprising:

a lens assembly for directing image-carrying light rays along a given path from a photographic scene to a focal plane;

a shutter system for controlling the transmission of light from the scene to the focal plane so as to define an exposure interval during an evaluation period;

an actuatable light source operative to produce both artificial visible and non-visible electromagetic radiation frequencies;

means for first actuating said light source to direct a first pulse of radiation of given intensity toward a subject in the scene prior to commencement of or in the early stages of said exposure interval to evaluate the subject including its distance from the camera system, and to subsequently actuate said light source to direct a second pulse of radiation toward the scene during said exposure interval to illuminate the subject for photographic recording during exposure;

means for evaluating the intensity of primarily non-visible frequencies of the scene during said first pulse of radiation;

means responsive to the evaluated intensity resulting from the scene including said first pulse for controlling at least one camera function of said system, whereby said non-visible frequencies from said source is utilized for subject evaluation and subsequent camera system control, and said visible light from the same source is utilized for scene illumination for photographic recording during the exposure interval; and

said evaluating means includes a photocell sensitive to both visible and non-visible frequencies and means for blocking transmission of visible frequencies to said photocell during the first pulse for determining said scene information and for permitting transmission of visible radiation to said photocell at another time to evaluate scene lighting for the photographic recording during exposure.

27. A camera system comprising:

a lens assembly for directing image-carrying light rays along a given path from a photographic scene to a focal plane;

a shutter system for controlling the transmission of light from the scene to the focal plane so as to define an exposure interval during an evaluation period;

an actuatable light source operative to produce both artificial visible and non-visible electromagetic radiation frequencies;

means for first actuating said light source to direct a first pulse of radiation of given intensity toward a subject in the scene prior to commencement of or in the early stages of said exposure interval to evaluate the subject including its distance from the camera system, and to subsequently actuate said light source to direct a second pulse of radiation toward the scene during said exposure interval to illuminate the subject for photographic recording during exposure;

means for evaluating the intensity of primarily non-visible frequencies of the scene during said first pulse of radiation;

means responsive to the evaluated intensity resulting from the scene including said first pulse for controlling at least one camera function of said system, whereby said non-visible frequencies from said source is utilized for subject evaluation and subsequent camera system control, and said visible light from the same source is utilized for scene illumination for photographic recording during the exposure interval; and

said lens assembly includes a variable objective lens assembly, and wherein said means for controlling said camera system includes means for varying said variable objective lens assembly to provide a focal position thereof in accordance with said evaluated intensity of said first pulse.

28. A method of determining the object range for providing a photographic exposure at least in part with artificial illumination and with photographic apparatus having means for controlling the transmission of light along an exposure path for defining an exposure interval during an exposure period, ranging means including a source of artificial light actuatable for illuminating the scene with both visible and non-visible radiation, means for evaluating the radiation from a photographic scene, and means for actuating said source, the method comprising the steps of:

actuating said source to direct a first pulse of electromagnetic radiation at a subject in the photographic scene;

evaluating radiation from the scene with the contribution to the evaluation of the visible frequencies being reduced relative to that of the non-visible frequencies radiating from said scene during said first pulse;

controlling at least one photographic function operative in correspondence with the evaluated radiation; and

said step of controlling at least one photographic function comprises varying the focal position of the camera lens in correspondence with said evaluated amplitude.

29. A method of determining the object range for providing a photographic exposure at least in part with artificial illumination and with photographic apparatus having means for controlling the transmission of light along an exposure path for defining an exposure interval during an exposure period, ranging means including a source of artificial light actuatable for illuminating the scene with both visible and non-visible radiation, means for evaluating the amplitude of the radiation from a photographic scene, and means for actuating said source, the method comprising the steps of:

actuating said source to direct a first pulse of electromagnetic radiation at a subject in the photographic scene;

evaluating the amplitude of essentially only non-visible radiation reflected from the scene by said first pulse;

controlling at least one photographic function operative during the exposure period in correspondence with the evaluated amplitude of said non-visible radiation;

initiating the exposure interval;

again actuating said source to produce a second pulse to illuminate the subject during the exposure period; and

said step of controlling at least one photographic function comprises varying the focal position of the camera lens in correspondence with said evaluated amplitude.