AE lock device for camera
AssigneeCanon Kabushiki Kaisha
InventorsYoshihiko Aihara, Shuichi Kiyohara, Akira Yamada
Life of this patent
Estimating the term…
Abstract
The present invention relates to a so-called AE lock device for camera, and more particularly to such device in which as the object brightness is changing rapidly, when the stored value of brightness at the time of the AE lock is later found to give an improper exposure value, either photographer is warned of this, or the AE lock mode is cancelled automatically.
Claims8
A camera in which information representing brightness from a light metering circuit is memorized when an AE lock is actuated, and the exposure is controlled in accordance with said memorized brightness, comprising:
- (a) detecting means for detecting information corresponding to the brightness from said light metering circuit upon change of said detected information corresponding to the brightness from the memorized value at the time of actuation of the AE lock by more than a prescribed value to produce an output;
- and
- (b) indicating means responsive to the output of said detecting means for producing a warning indication.
A camera in which information representing brightness from a light metering circuit is memorized when an AE lock is actuated, and the exposure is controlled in accordance with said memorized brightness, comprising:
- (a) detecting means for detecting information corresponding to the brightness from said light metering circuit upon change of said detected information corresponding to the brightness from the memorized value at the time of actuation of the AE lock by more than a prescribed value to produce an output;
- and
- (b) a reset circuit responsive to the output of said detecting means for cancelling the AE lock mode.
A camera in which a signal from a photographic information forming circuit for producing a corresponding signal to a given photographic situation is memorized by a manual operation before the actuation of a camera release, and the photographic operation is controlled based on said memorized value, including:
- (a) detecting means for detecting the signal from said information forming circuit upon change of the detected signal from the memorized value at the time of the manual operation by more than a prescribed value to produce an output;
- and
- (b) indicating means responsive to the output of said detecting means for producing a warning indication.
A camera in which a signal from a photographic information circuit for producing a corresponding signal to a given photographic situation is memorized by a manual operation before actuation of a camera release, and the photographic operation is controlled based on said memorized value, including:
- (a) detecting means for detecting the signal from said information forming circuit upon change of the detected signal from the memorized value at the time of the manual operation by more than a presecribed value to produce an output;
- and
- (b) a control circuit including a selecting circuit which selects an output of said information forming circuit when it is detected that a signal from said information forming circuit changes by more than said prescribed value with respect to the memorized value, and selects the memorized value when a change more than the prescribed value is not detected, said control circuit controlling the photographic operation on the basis of the selected memorized value or the selected output of said information forming circuit.
Dependencies are inferred from the claim text.