Automatic flash control device of camera
AssigneeNikon Corporation
InventorTadao Takagi
Life of this patent
Estimating the term…
Abstract
An automatic flash control device of a camera includes a flashing source for performing preliminary flashing and main flashing, a first photodetector for measuring a light beam reflected by an object field and reflected by a shutter curtain via a taking lens upon preliminary flashing from the flashing source before exposure, and a second photodetector for measuring a light beam reflected by the object field and reflected by a film surface via the taking lens upon main flashing from the flashing source during exposure. In this device, the displacement between photometry areas caused by the different positions of the shutter curtain and the film surface is corrected, and the identity between object field areas to be measured in the preliminary flashing mode and the main flashing mode can be assured.
Claims11
An automatic flash control device of a camera, comprising:
- flashing means for performing preliminary flashing and main flashing;
- first photometry means having a plurality of light-receiving areas for measuring a light beam reflected by an object field and reflected by a shutter curtain via a taking lens upon preliminary flashing from said flashing means before exposure;
- and
- second photometry means having a plurality of light-receiving areas for measuring a light beam reflected by the object field and reflected by a film surface via the taking lens upon main flashing from said flashing means during exposure;
- wherein said second photometry means has at least one light-receiving area which is different from the light-receiving areas of said first photometry means.
An automatic flash control device of a camera, comprising:
- flashing means for performing preliminary flashing and main flashing;
- first photometry means having a first light receiving portion for measuring a light beam reflected by an object field and reflected by a shutter curtain via a taking lens upon preliminary flashing from said flashing means before exposure;
- and
- second photometry means having a second light receiving portion, which is different from said first light receiving portion, for measuring a light beam reflected by an object field and reflected by a film surface via the taking lens upon main flashing from said flashing means during exposure.
An automatic flash control device of a camera, comprising:
- a photometry device including a plurality of light-receiving elements disposed at a bottom of the camera;
- and
- a microcomputer which is electrically connected to said plurality of light-receiving elements;
- wherein said microcomputer selects light-receiving elements from said plurality of light-receiving elements for use in preliminary flashing and for use in main flashing, at least one of the selected light-receiving elements selected for use in preliminary flashing being different from the light-receiving elements selected for use in main flashing.
Dependencies are inferred from the claim text.