GB2008783A - Cameras - Google Patents

Cameras

Info

Publication number
GB2008783A
GB2008783A GB7845455A GB7845455A GB2008783A GB 2008783 A GB2008783 A GB 2008783A GB 7845455 A GB7845455 A GB 7845455A GB 7845455 A GB7845455 A GB 7845455A GB 2008783 A GB2008783 A GB 2008783A
Authority
GB
United Kingdom
Prior art keywords
photodetector
aperture
light
blades
exposure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB7845455A
Other versions
GB2008783B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Polaroid Corp
Original Assignee
Polaroid Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US05/860,639 external-priority patent/US4174893A/en
Application filed by Polaroid Corp filed Critical Polaroid Corp
Publication of GB2008783A publication Critical patent/GB2008783A/en
Application granted granted Critical
Publication of GB2008783B publication Critical patent/GB2008783B/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/08—Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
    • G03B7/081—Analogue circuits
    • G03B7/087—Analogue circuits for control of both exposure time and aperture
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/16—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly 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

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Control For Cameras (AREA)
  • Studio Devices (AREA)
  • Indication In Cameras, And Counting Of Exposures (AREA)
  • Diaphragms For Cameras (AREA)

Abstract

A camera has shutter-diaphragm blades (40, 42) openable to define a primary aperture (46-48) for passing light to the film plane and a secondary aperture (50-52) for passing light to a photodetector (58) for controlling exposure; the blades also being arranged to admit light to the photodetector before exposure for indicating whether the brightness is adequate for exposure without flash. Preferably, a visual indication is given by means of a LED, and preferably if the brightness is not adequate, operation of the camera without flash is inhibited. The passage of light to the photodetector before exposure may be allowed by a third aperture (54- 56) in the blades, or by an extension of a secondary aperture (59, Figure 7 not shown). In another form, two blades (40,42, Figures 2a to 4a not shown) are contoured to provide tabs (54', 56') which are spaced before exposure to allow light to reach the photodetector along a path, distinct from the path provided by the secondary aperture. Alternatively, an aperture controlling the light path to the photodetector may be provided in an independently operable third blade. <IMAGE>
GB7845455A 1977-11-25 1978-11-21 Photographic cameras Expired GB2008783B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US85469177A 1977-11-25 1977-11-25
US05/860,639 US4174893A (en) 1977-12-14 1977-12-14 Exposure control system for use in photographic camera apparatus

Publications (2)

Publication Number Publication Date
GB2008783A true GB2008783A (en) 1979-06-06
GB2008783B GB2008783B (en) 1982-07-21

Family

ID=27127248

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7845455A Expired GB2008783B (en) 1977-11-25 1978-11-21 Photographic cameras

Country Status (5)

Country Link
JP (1) JPS5483425A (en)
DE (1) DE2850999A1 (en)
FR (1) FR2410294A1 (en)
GB (1) GB2008783B (en)
IE (1) IE47583B1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2954241C2 (en) * 1978-04-21 1984-02-23 Copal Co. Ltd., Tokyo FAILURE EXPOSURE WARNING DEVICE FOR CAMERAS WITH A PROGRAMMABLE ELECTRICAL SHUTTER
JPS58154824A (en) * 1983-02-18 1983-09-14 Canon Inc Exposure controller
JPS59162514A (en) * 1983-03-08 1984-09-13 Dainippon Screen Mfg Co Ltd Focus adjusting method of image scanning and recording device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3942183A (en) * 1974-07-02 1976-03-02 Polaroid Corporation Camera with pivoting blades
US4047190A (en) * 1975-10-10 1977-09-06 Polaroid Corporation Hybrid exposure control system employing dual maximum blade displacement
US4040072A (en) * 1976-01-13 1977-08-02 Polaroid Corporation Shutter latch arrangement releasable through shutter blade actuation and resettable through film advancement

Also Published As

Publication number Publication date
IE47583B1 (en) 1984-05-02
GB2008783B (en) 1982-07-21
IE782256L (en) 1979-05-25
FR2410294B1 (en) 1985-02-22
FR2410294A1 (en) 1979-06-22
JPS5483425A (en) 1979-07-03
DE2850999A1 (en) 1979-05-31

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee