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US4878081A Expired / Lapsed US ⏱️ 0.0 years remaining

Exposure control device for a camera

Assignee: Ricoh Co Ltd
•
Filing: 1988-08-22
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Granted: 1989-10-31
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Expires: 2008-08-22
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Abstract

Abstract An exposure control device for a camera having a photometric unit for measuring brightness of an object and its ambient brightness individually, a range finding unit for measuring a distance from the device to the object, and a strobe light unit, the device including backlight detecting unit for detecting whether the object is in a backlight condition or not on the basis of the brightness of the object and its ambient brightness measured by the photometric unit; and a unit for allowing the strobe light to flash in either case the brightness of the object measured by the photometric unit is smaller than a predetermined brightness or the object is detected to be in the backlight condition by the backlight detecting unit, if the distance from the device to the object measured by the range finding unit is smaller than a predetermined distance, and for lengthening an exposure time without allowing the strobe light to flash within the limits of a predetermined time in case the object is detected to be in the backlight condition by the backlight detecting unit, if the distance from the device to the object measured by the range finding unit is larger than the predetermined distance.

Inventors

  • 👤 Daisuke Kishida
  • 👤 Saburo Sasaki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 11:26
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/28; G03B7/08; G03B7/091; G03B7/093; G03B7/16; G03B2217/00; G03B2217/005

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 200 words
An exposure control device for a camera having a photometric unit for measuring brightness of an object and its ambient brightness individually, a range finding unit for measuring a distance from the device to the object, and a strobe light unit, said device comprising: backlight detecting means for detecting whether the object is in a backlight condition or not on the basis of the brightness of the object and its ambient brightness measured by the photometric unit; and means for allowing the strobe light to flash in either case the brightness of the object measured by the photometric unit is smaller than a predetermined brightness or the object is detected to be in the backlight condition by the backlight detecting means, if the distance from the device to the object measured by the range finding unit is smaller than a predetermined distance, and for lengthening an exposure time without allowing the strobe light to flash within the limits of a predetermined time in case the object is detected to be in the backlight condition by the backlight detecting means, if the distance from the device to the object measured by the range finding unit is larger than the predetermined distance.
Claim 2
Dependent Claim 200 words
An exposure control device for a camera having a photometric unit for measuring brightness of an object and its ambient brightness individually, a range finding unit for measuring a distance from the device to the object, and a strobe light unit, said device comprising: backlight detecting means for detecting whether the object is in a backlight condition or not on the basis of the brightness of the object and its ambient brightness measured by the photometric unit; and means for allowing the strobe light to flash in either case the brightness of the object measured by the photometric unit is smaller than a predetermined brightness or the object is detected to be in the backlight condition by the backlight detecting means, if the distance from the device to the object measured by the range finding unit is smaller than a predetermined distance, and for lengthening an exposure time without allowing the strobe light to flash within the limits of a predetermined time in case the object is detected to be in the backlight condition by the backlight detecting means, if the distance from the device to the object measured by the range finding unit is larger than the predetermined distance.
Claim 3
Dependent Claim 19 words
A device according to claim 1, wherein said predetermined brightness and said predetermined distance are stored in a memory.
Claim 4
Dependent Claim 42 words
A device according to claim 1, wherein the backlight detecting means is adapted to detect that the object is in the backlight condition if the difference between the brightness of the object and its ambient brightness is larger than a predetermined value.
Claim 5
Dependent Claim 15 words
A device according to claim 3, wherein said predetermined value is stored in a memory.
Claim 6
Dependent Claim 29 words
A device according to claim 1, wherein the means for allowing the strobe light to flash is adapted to lengthen the exposure time in accordance with a film sensitivity.

References Cited (Backward Citations)

US3855601A Cited
US4690536A Cited
US4801964A Cited
US4812872A Cited
US4772910A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-10-30 1993-05-01 1993-10-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-10-30 1997-05-01 1997-10-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-10-30 2001-05-01 2001-10-31 $7700.00 Window Closed / Lapsed

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