GB1530969A - Cameras - Google Patents

Cameras

Info

Publication number
GB1530969A
GB1530969A GB4170076A GB4170076A GB1530969A GB 1530969 A GB1530969 A GB 1530969A GB 4170076 A GB4170076 A GB 4170076A GB 4170076 A GB4170076 A GB 4170076A GB 1530969 A GB1530969 A GB 1530969A
Authority
GB
United Kingdom
Prior art keywords
capacitor
switch
circuit
exposure
fet
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.)
Expired
Application number
GB4170076A
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.)
Rollei Werke Franke und Heidecke GmbH and Co KG
Original Assignee
Rollei Werke Franke und Heidecke GmbH and Co KG
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
Application filed by Rollei Werke Franke und Heidecke GmbH and Co KG filed Critical Rollei Werke Franke und Heidecke GmbH and Co KG
Publication of GB1530969A publication Critical patent/GB1530969A/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
    • G03B7/083—Analogue circuits for control of exposure time

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Control For Cameras (AREA)
  • Indication In Cameras, And Counting Of Exposures (AREA)
  • Shutter-Related Mechanisms (AREA)
  • Stroboscope Apparatuses (AREA)
  • Discharge-Lamp Control Circuits And Pulse- Feed Circuits (AREA)

Abstract

1530969 Camera exposure control and indication FRANKE & HEIDECKE GmbH [Trading as ROLLEI-WERKE FRANKE & HEIDECKE] 7 Oct 1976 [18 Oct 1975] 41700/76 Heading G2A A camera has a photodiode 3 and integrating capacitor 4 connected to the input of an FET 2 and a circuit 1 connected to the output of the FET 2 and switchable between exposure control and exposure indicating modes. The circuit 1 includes means 18 for charging the capacitor 4 during the indicating mode with a pulsed current opposed to the photoelectric current. The FET 2 has a high input impedance necessary for use with the low currents produced by the photo-diode 3 and a low output impedance enabling conventional switches to be used in the circuit 1. Exposure control mode. Switch 19 is left open. Upon shutter release: (a) a switch 17 closes to charge capacitor 4 according to the setting of a film speed resistor 16. (b) as the shutter starts to open, switch 17 reopens and the photo-electric current charges capacitor 4 to the opposite polarity. (c) eventually, capacitor 4 is charged to a voltage which triggers a switching circuit 27 to deenergize a shutter closing electromagnet 12 and energize an LED indicator 14. Exposure indicating mode. Switch 17 is left open and switch 19 is closed to turn on an oscillator 18. This provides squarewaves which are differentiated by RC member 16, 20 to provide pulses which charge capacitor 4 in the opposite direction to the photo-electric current. Eventually, capacitor 4 reaches an equilibrium voltage. If illumination is too low for a hand held exposure, switching circuit 27 is not triggered by capacitor 4 so transistor 13 stays off and LED 14 is flashed by oscillator 18 via diode 21. If illumination is acceptable, capacitor 4 triggers circuit 27 to turn on transistor 13 and illuminate LED 14 continuously.
GB4170076A 1975-10-18 1976-10-07 Cameras Expired GB1530969A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19752546823 DE2546823C3 (en) 1975-10-18 1975-10-18 Device for exposure measurement, exposure display and exposure control for a photographic camera

Publications (1)

Publication Number Publication Date
GB1530969A true GB1530969A (en) 1978-11-01

Family

ID=5959530

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4170076A Expired GB1530969A (en) 1975-10-18 1976-10-07 Cameras

Country Status (3)

Country Link
JP (1) JPS5250723A (en)
DE (1) DE2546823C3 (en)
GB (1) GB1530969A (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5677332A (en) * 1979-11-29 1981-06-25 Nisshin Steel Co Ltd Production of steel strip for production of shadow mask
JPS62205232A (en) * 1986-03-03 1987-09-09 Kobe Steel Ltd Manufacture of ultrathin cold rolled soft steel sheet superior in ductility and deep drawability by low temperature box annealing
JPS62294136A (en) * 1986-06-13 1987-12-21 Kobe Steel Ltd Manufacture of extra thin cold-rolled soft steel sheet excellent in ductility and deep drawability by box annealing at low temperature
JPS6369922A (en) * 1986-09-10 1988-03-30 Kobe Steel Ltd Production of extremely thin cold rolled mild steel sheet having excellent ductility and deep drawability by low temperature annealing
JPH0765114B2 (en) * 1986-12-09 1995-07-12 株式会社神戸製鋼所 Method for manufacturing ultra-thin cold-rolled mild steel sheet with excellent ductility and deep drawability by low-temperature annealing
JPH07110976B2 (en) * 1989-09-11 1995-11-29 川崎製鉄株式会社 Manufacturing method of cold-rolled steel sheet for deep drawing with small in-plane anisotropy
JPH0397812A (en) * 1989-09-11 1991-04-23 Kawasaki Steel Corp Production of cold rolled steel sheet for deep drawing

Also Published As

Publication number Publication date
DE2546823B2 (en) 1978-05-24
DE2546823A1 (en) 1977-04-21
JPS5250723A (en) 1977-04-23
DE2546823C3 (en) 1979-02-01
JPS5337743B2 (en) 1978-10-11

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Legal Events

Date Code Title Description
PS Patent sealed
746 Register noted 'licences of right' (sect. 46/1977)
PCNP Patent ceased through non-payment of renewal fee