Title: Camera circuit arrangement for the pre-indication of exposure time

Abstract: A circuit arrangement for the pre-indication of the exposure time to be expected in automatic mirror-reflex cameras in which the brightness of a controllable luminous element, which is constant for the duration of the exposure, is used for the illumination of the photo-receiver of the electronic time-formation system. The voltage dropping over the luminous element, which is proportional to the exposure time, is ascertained by means of a measuring mechanism. The luminous element is formed as luminous diode and in parallel therewith there is connected a current path containing the measuring mechanism fed from a constant current source for the compensation of the response voltage of the luminous diode and for the adaptation of the measuring mechanism to the characteristics of the luminous diode.

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Inventors: Schutze, Siegfried (Dresden, DL)
Locke, Werner (Radebeul, DL)

Application Number: 578319
Filing Date: 1975-05-16
Publication_date: 1976-12-14
Assignee: VEB Pentacon Dresden (DL)
Primary Class(es): 396/221 356/226
Other Classes:
US Patent Ref:

3470798	Oct, 1967	Miyakawa	354/51.
3698298	Oct, 1972	Kikuchi et al.	354/60.
3765312	Oct, 1973	Takishima	354/51.

Other Refs: 4,730,854

, 1972	JA

Primary Examiner: Peters, Jr., Joseph F.
Assistant Examiner:
Attorney: Drucker; William Anthony