US3583299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Environmentally compensated follow-focus flash photography
Assignee: Polaroid Corp
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Filing: 1968-10-07
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Granted: 1971-06-08
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Expires: 1988-10-07
Abstract
Abstract An exposure control system for flash photography. With the system, an initial exposure value determination is made based upon camera-to-subject distance and the intensity of the source of flash illumination. This exposure value is corrected by a value representing the reflective characteristics of the environment surrounding the subject of principal photographic interest. The latter correction may be derived by measuring and integrating environmental reflection from a metering light source. The metering light source is provided at a frequency nonharmonically related to that of ambient artificial illumination.
Inventors
- 👤 Edwin H Land
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:28
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/16; G03B9/00; G03B9/70
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
143 words
A flash exposure control system for use with a photographic camera comprising: means for defining an exposure aperture having an effective area representing a first exposure parameter and for uncovering and covering said exposure aperture for an interval of time representing a second exposure parameter; artificial illuminating means for illuminating a photographic subject from a position adjacent said camera during the period when said aperture is uncovered with light of an intensity representing a third exposure parameter; means for determining camera-to-subject distance and deriving a first factor representative thereof; means for causing said photographic subject and its surrounding environment to be illuminated with a metering light of predetermined intensity; means responsive to the metering light reflected from said subject and said environment for deriving a second factor; and means responsive to both of said factors for varying at least one of said parameters.
Claim 2
Dependent Claim
143 words
A flash exposure control system for use with a photographic camera comprising: means for defining an exposure aperture having an effective area representing a first exposure parameter and for uncovering and covering said exposure aperture for an interval of time representing a second exposure parameter; artificial illuminating means for illuminating a photographic subject from a position adjacent said camera during the period when said aperture is uncovered with light of an intensity representing a third exposure parameter; means for determining camera-to-subject distance and deriving a first factor representative thereof; means for causing said photographic subject and its surrounding environment to be illuminated with a metering light of predetermined intensity; means responsive to the metering light reflected from said subject and said environment for deriving a second factor; and means responsive to both of said factors for varying at least one of said parameters.
Claim 3
Dependent Claim
49 words
The flash exposure control system of claim 1 wherein said illuminating means is operative to illuminate said environment with artificial metering light generated at a frequency nonharmonic with artificial ambient illumination; and wherein said second factor deriving means is operative to respond only to reflections at said nonharmonic frequency.
Claim 4
Dependent Claim
37 words
The flash exposure control system of claim 2 wherein said first factor deriving means is operative to derive said first factor in correspondence with the light energy available from said artificial illuminating means at said camera-to-subject distance.
Claim 5
Dependent Claim
28 words
The flash exposure control system of claim 3 wherein said metering light responsive means is operable to derive said second factor as a function of said camera-to-subject distance.
Claim 6
Dependent Claim
40 words
The flash exposure control system of claim 3 wherein said factor responsive means is operative to derive a controlling function representing said first factor adjusted by the magnitude of said second factor for varying at least one of said parameters.
Claim 7
Dependent Claim
50 words
The exposure control system of claim 5 in which said second factor deriving means includes: photodetection means for sensing said environmentally reflected metering light and deriving a signal representative thereof; and means responsive only to said photodetected signal representing the said environmentally reflected light for deriving an integrated value thereof.
Claim 8
Dependent Claim
87 words
In combination: A photographic camera having an exposure mechanism including exposure aperture means and shutter means at least one of which is controllable in accordance with an exposure value; an artificial lighting unit for illuminating a subject from a position adjacent the Camera; means for energizing said unit during an exposure; and control means responsive both to a camera-to-subject distance and to the reflective characteristics of the environment surrounding said subject for deriving an exposure value and causing the regulation of said exposure mechanism in accordance therewith.
Claim 9
Dependent Claim
87 words
In combination: A photographic camera having an exposure mechanism including exposure aperture means and shutter means at least one of which is controllable in accordance with an exposure value; an artificial lighting unit for illuminating a subject from a position adjacent the Camera; means for energizing said unit during an exposure; and control means responsive both to a camera-to-subject distance and to the reflective characteristics of the environment surrounding said subject for deriving an exposure value and causing the regulation of said exposure mechanism in accordance therewith.
Claim 10
Dependent Claim
20 words
The combination set forth in claim 7 including means for artificially illuminating the environment surrounding said subject with metering light.
Claim 11
Dependent Claim
62 words
The combination of claim 8 wherein said control means includes: means responsive to the environmental reflection of said metering light for providing a first function representative thereof; means for deriving a second function corresponding to the light energy available from said lighting unit at said camera-to-subject distance; and regulating means responsive to said first and second functions for controlling said exposure mechanism.
Claim 12
Dependent Claim
23 words
The combination of claim 9 wherein said environmentally responsive means is operative to derive said first function in accordance with said camera-to-subject distance.
Claim 13
Dependent Claim
32 words
The combination of claim 10 wherein said environmentally responsive means is operative to derive said first function as an integrated value of said metered light diminished in correspondence with said camera-to-subject distance.
Claim 14
Dependent Claim
29 words
The combination of claim 11 wherein said regulating means is operative to derive a said exposure value representing said second function adjusted by the magnitude of said first function.
Claim 15
Dependent Claim
75 words
An environmentally compensated range-responsive exposure control system for use in photographing a subject located a predetermined distance from a camera comprising: an artificial lighting unit for illuminating the said subject from a position adjacent the camera; an exposure mechanism having at least one controllable exposure parameter; and control means responsive both to said camera-to-subject distance and to the reflective characteristics of the environment surrounding said subject for controlling said exposure mechanism to regulate an exposure.
Claim 16
Dependent Claim
75 words
An environmentally compensated range-responsive exposure control system for use in photographing a subject located a predetermined distance from a camera comprising: an artificial lighting unit for illuminating the said subject from a position adjacent the camera; an exposure mechanism having at least one controllable exposure parameter; and control means responsive both to said camera-to-subject distance and to the reflective characteristics of the environment surrounding said subject for controlling said exposure mechanism to regulate an exposure.
Claim 17
Dependent Claim
23 words
The exposure control system of claim 13 including means for illuminating the environment toward which said camera is oriented with artificial metering light.
Claim 18
Dependent Claim
65 words
The exposure control system of claim 14 in which said control means includes: means adjustable in accordance with said camera-to-subject distance for providing a first variable function; means responsive to the environmental reflection characteristics from said metering artificial light for deriving a second variable function; and means responsive to said first and second functions for effecting a control of at least said one exposure parameter.
Claim 19
Dependent Claim
38 words
The control system of claim 15 wherein said reflection responsive means includes: means for assessing the light value of said environmentally reflected metering light; and means for adjusting said assessed light value with respect to said camera-to-subject distance.
Claim 20
Dependent Claim
34 words
The control system of claim 16 in which said adjustable means is operable to derive said first variable function in correspondence with the light energy available from said lighting unit at said camera-to-subject distance.
Claim 21
Dependent Claim
45 words
The control system of claim 17 in which said metering light illuminating means is operable to generate artificial light at an excitation frequency nonharmonic with artificial ambient illumination; and wherein said assessing means is operative to respond only to environmental reflections at said nonharmonic frequency.
Claim 22
Dependent Claim
49 words
The control system of claim 18 in which said reflection responsive means includes: photodetection means for sensing said environmentally reflected metering light and deriving a signal representative thereof; and means responsive only to said photodetected signal representing the said environmentally reflected metering light for deriving an integrated value thereof.
Claim 23
Dependent Claim
93 words
A camera for photographing a subject located a predetErmined distance therefrom comprising: an exposure mechanism including exposure aperture means and shutter means at least one of which is controllable in accordance with an exposure value; means mounted with said camera for controlling the energization of a lighting unit; means adjustable in accordance with said camera-to-subject distance for providing a first variable function; means responsive to the reflection characteristics of the environment surrounding said subject for providing a second variable function; and means responsive to both of said functions for deriving said exposure value.
Claim 24
Dependent Claim
93 words
A camera for photographing a subject located a predetErmined distance therefrom comprising: an exposure mechanism including exposure aperture means and shutter means at least one of which is controllable in accordance with an exposure value; means mounted with said camera for controlling the energization of a lighting unit; means adjustable in accordance with said camera-to-subject distance for providing a first variable function; means responsive to the reflection characteristics of the environment surrounding said subject for providing a second variable function; and means responsive to both of said functions for deriving said exposure value.
Claim 25
Dependent Claim
23 words
The camera of claim 20 wherein said reflection responsive means includes means for deriving an integrated light value for said environmental reflection characteristics.
Claim 26
Dependent Claim
25 words
The camera of claim 20 wherein said exposure value deriving means includes means for controlling said exposure mechanism in accordance with said derived exposure value.
Claim 27
Dependent Claim
37 words
The camera of claim 22 wherein said reflection responsive means includes: means for deriving an integrated light value for said environmental reflection characteristics; and means for adjusting said integrated light value with respect to said camera-to-subject distance.
Claim 28
Dependent Claim
32 words
The camera of claim 23 wherein said adjustable means is operable to derive said first variable function in correspondence with the light energy available from said lighting unit at said camera-to-subject distance.
Claim 29
Dependent Claim
47 words
The camera of claim 24 in which said reflection responsive means includes: means for illuminating said environment from a metering light source so as to cause environmental light reflection; and means for assessing the characteristic of said environmental light reflection and deriving a light value representative thereof.
Claim 30
Dependent Claim
19 words
The camera of claim 25 including means for adjusting said assessed light value in correspondence with said camera-to-subject distance.
Claim 31
Dependent Claim
50 words
The camera of claim 24 in which said reflection responsive means includes: means for illuminating said environment with metering light generated at an excitation frequency nonharmonic with artificial ambient illumination; and means responsive only to the environmental reflection of said nonharmonically generated light for deriving a light value representative thereof.
Claim 32
Dependent Claim
18 words
The camera of claim 27 including means for adjusting said light value in correspondence with said camera-to-subject distance.
Claim 33
Dependent Claim
89 words
An environmentally compensated range responsive exposure control system for use in photographing a subject located a predetermined distance from a camera comprising: an artificial lighting unit for illuminating said subject from a position adjacent the camera; means for energizing said lighting unit during an exposure; an exposure mechanism having at least one controllable exposure parameter; means for illuminating the environment surrounding said subject with metering artificial light; and control means responsive to the environmental reflection of said metering light and to said predetermined distance for controlling said exposure parameter.
Claim 34
Dependent Claim
89 words
An environmentally compensated range responsive exposure control system for use in photographing a subject located a predetermined distance from a camera comprising: an artificial lighting unit for illuminating said subject from a position adjacent the camera; means for energizing said lighting unit during an exposure; an exposure mechanism having at least one controllable exposure parameter; means for illuminating the environment surrounding said subject with metering artificial light; and control means responsive to the environmental reflection of said metering light and to said predetermined distance for controlling said exposure parameter.
Claim 35
Dependent Claim
48 words
The exposure control system of claim 29 wherein said illuminating means is operative to illuminate said environment with artificial metering light generated at a frequency nonharmonic with artificial ambient illumination; and wherein said control means is operative to respond only to said environmental reflections at said nonharmonic frequency.
Claim 36
Dependent Claim
66 words
The exposure control system of claim 30 wherein said control means comprises: means for assessing said environmentally reflected metered light and deriving a first value representative thereof; means for deriving a second value corresponding to the light energy available from said lighting unit at said predetermined subject distance; and means responsive to both said first and second values for controlling at least said one exposure parameter.
Claim 37
Dependent Claim
26 words
The exposure control system of claim 31 wherein said assessing means is operable to derive said first value as a function of said predetermined subject distance.
Claim 38
Dependent Claim
37 words
The exposure control system of claim 32 wherein said means responsive to both said first and second values is operative to derive a controlling function representing said second value adjusted by the magnitude of said first value.
Claim 39
Dependent Claim
39 words
The exposure control system of claim 33 wherein said means responsive to both said first and second values is operative to derive an exposure parameter control function representing said second value diminished by the amount of said first value.
Claim 40
Independent Claim
104 words
A method for controlling the exposure control mechanism of a photographic camera comprising the steps of: determining the camera-to-subject distance and deriving a first factor representative thereof; illuminating said subject and its surrounding environment from a position adjacent said camera with an artificial metering light source; deriving a second factor representative of the environmental reflection of said metering light; exposing a photosensitive material to light from said subject and its environment; simultaneously illuminating said subject and its environment with artificial illumination generated from a position adjacent said camera; and controlling the said exposure of said photosensitive material in accordance with both of said factors.
Claim 41
Independent Claim
104 words
A method for controlling the exposure control mechanism of a photographic camera comprising the steps of: determining the camera-to-subject distance and deriving a first factor representative thereof; illuminating said subject and its surrounding environment from a position adjacent said camera with an artificial metering light source; deriving a second factor representative of the environmental reflection of said metering light; exposing a photosensitive material to light from said subject and its environment; simultaneously illuminating said subject and its environment with artificial illumination generated from a position adjacent said camera; and controlling the said exposure of said photosensitive material in accordance with both of said factors.
Claim 42
Dependent Claim
42 words
The method of claim 35 wherein said subject and its environment are illuminated with light generated at an excitation frequency nonharmonic with artificial ambient illumination; and said second factor is derived in response only to said environmental reflections at said nonharmonic frequency.
Claim 43
Dependent Claim
27 words
The method of claim 36 wherein said first factor is derived in correspondence with the light energy available from the light source utilized for photographing said subject.
Claim 44
Dependent Claim
18 words
The method of claim 36 wherein said second factor is derived as in correspondence with said camera-to-subject distance.
Claim 45
Dependent Claim
29 words
The method of claim 38 wherein said camera exposure performance is controlled in accordance with a function representing said first factor adjusted by the magnitude of said second factor.
Claim 46
Dependent Claim
33 words
The method of claim 36 wherein said nonharmonic illumination is provided at an intensity selected in correspondence with the intensity of said ambient illumination so as to be substantially nonperceptive to human acuity.
Claim 47
Dependent Claim
52 words
The method of claim 36 wherein said second factor is derived by: photodetecting the reflection from said illuminated environment so as to derive a signal corresponding thereto; integrating the portion of said signal representing only reflection from said nonharmonically generated light; and adjusting said integrated signal in correspondence with said camera-to-subject distance.
Claim 48
Dependent Claim
29 words
The method of claim 41 wherein said camera exposure performance is controlled in accordance with a function representing said first factor adjusted by the magnitude of said second factor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-07 | 1974-12-07 | 1975-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-07 | 1978-12-07 | 1979-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-07 | 1982-12-07 | 1983-06-08 | $7700.00 | Window Closed / Lapsed |