Photographic exposure control with scene light integration level determined as function of pre-exposure ambient scene light detect
AssigneePolaroid Corporation
InventorsPeter P. Carcia, Arthur N. Woodbury
Life of this patent
Estimating the term…
Abstract
A photographic exposure control system provides for the termination of an exposure interval as a predetermined function of the scene light detected during the exposure interval wherein at least one parameter of the predetermined function is varied as another function of the ambient scene light detected prior to the exposure interval. The predetermined function may comprise the integration of the detected scene light to a selected level wherein the selected level of integration is the one parameter varied as a function of the ambient scene light detected prior to the exposure interval.
Claims12
A photographic camera apparatus of the type adapted to be energized at least in part by a source of electrical energy and including means for defining a film plane comprises:
- shutter means for admitting scene light to the film plane to define an exposure interval;
- a photoresponsive element stationed to receive light from the scene to be photographed both immediately prior to and during the exposure interval in order to provide an output signal having an electrical characteristic which varies as a function of the intensity of light incident thereon;
- and
- exposure control means for controlling the duration of said exposure interval comprising means for integrating the output signal from said photoresponsive element during said exposure interval and for providing a control signal for effecting the termination of said exposure interval in response to the integrated output signal from said photoresponsive element reaching a selected value and for varying said selected value of said integrated output signal in response to the output signal provided from said photoresponsive element immediately prior to said exposure interval.
A photographic camera apparatus of the type adapted to be energized at least in part by a source of electrical energy and including means for defining a film plane comprises:
- a photoresponsive element for providing an output signal having an electrical characteristic which varies as a function of the intensity of light incident thereon;
- a shutter blade mechanism;
- means for mounting said shutter blade mechanism for displacement from a first arrangement in which said shutter blade mechanism simultaneously permits the admission of scene light to said photoresponsive element and blocks the admission of scene light to the film plane to a second arrangement in which said shutter blade mechanism simultaneously blocks the admission of scene light to the film plane and to said photoresponsive element and then to a third arrangement in which said shutter blade mechanism simultaneously permits the admission of scene light to both the film plane and said photoresponsive element to define an exposure interval and then back to a fourth arrangement in which said shutter blade mechanism blocks the admission of scene light to the film plane to terminate the exposure interval;
- and
- exposure control means for controlling the duration of said exposure interval as a function of the output signals from said photoresponsive element when said blade mechanism is in its said first and third arrangements.
A photographic camera apparatus of the type adapted to be energized at least in part by a source of electrical energy and including means for defining a film plane comprises:
- shutter means for admitting scene light to the film plane to define an exposure interval;
- a photoresponsive element stationed to receive light from the scene to be photographed both immediately prior to and during the exposure interval in order to provide an output signal having an electrical characteristic which varies as a function of the intensity of light incident thereon;
- and
- exposure control means for controlling the duration of said exposure interval by providing an exposure terminating control signal as a predetermined function of the output signal from said photoresponsive element during the exposure interval wherein at least one parameter of said function by which said exposure terminating control signal is determined is varied as another function of the output signal from said photoresponsive element immediately prior to the exposure interval.
Dependencies are inferred from the claim text.