US 5,499,075 AGranted

Photometric apparatus for a camera

AssigneeNikon Corporation

InventorsToshihiro Sato, Tadao Takagi, Seiichi Yasukawa

Life of this patent

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Abstract

A photometric apparatus of a camera for carrying out a multi-segmented photometry by receiving object light reflected at a film or the shutter includes a plurality of photometric elements which are disposed at positions to respectively receive reflected light from the film or the shutter. The elements segmented in accordance with each of regions segmenting the object field, corresponding to regions of the film or the shutter, and are arranged in parallel in a predetermined direction within a mirror box so as to respectively receive light reflected with diffusion angles less than a predetermined angle from respective reflection regions of the film or the shutter. Photometric lenses are respectively positioned between the reflection regions and the photometric elements, corresponding to the photometric elements, so as to respectively direct the object lights reflected at the reflection regions to the plurality of photometric elements, and are arranged in parallel so as to restrict incidence of reflected light on the photometric elements from other reflection regions.

Claims7

Dependent claims

Auto light adjusting apparatus of a camera having a focal plane shutter which is disposed on an object side in the vicinity of a film and which shields or passes light from an object, comprising:

a flash apparatus which emits a preliminary flash and a main flash;
a flash control circuit for causing said flash apparatus to emit a preliminary flash before an opening operation of said focal plane shutter, for causing said flash apparatus to emit a main flash after the opening of the focal plane shutter, and for causing flash emission of said flash apparatus to stop;
a plurality of photometric elements being disposed at positions at which light reflected by a surface of said film may be received, and being segmented so as to respectively correspond to a plurality of regions obtained by segmenting an object field which corresponds to said film surface;
a detector for respectively detecting outputs of said plurality of photometric elements;
a weighting amount calculator for detecting reflection rate distributions of said object field based on outputs of said detector at the time of a preliminary flash operation of said flash apparatus, and for determining weights for electrical outputs of said plurality of photometric elements at the time of a main flash operation;
and
a light adjusting device for outputting to said flash control circuit an emission stop signal for said flash apparatus upon a detection at the time of the main flash operation of said flash apparatus of the fact that the total of the outputs of the said plurality of photometric elements to which weights are assigned by said weighting amount calculator has reached a predetermined level.

4 more elements

A TTL auto light adjusting camera comprising:

flash apparatus capable both of a preliminary flash to be emitted before a flash photographing and of a main flash to be emitted for the flash photographing;
a photometric device segmenting an object field into a plurality of regions for respectively outputting photometric signals by measuring reflected light from said plurality of regions;
a weighting amount calculator for obtaining weighting amounts by which corrections are made on photometric signals of said photometric device obtained at the time of said main flash, based on photometric signals of said photometric device obtained at the time of said preliminary flash;
a light adjusting device for stopping an emission of said flash apparatus in accordance both with photometric signals from said photometric device at the time of said main flash and with the weighting amounts obtained from said weighting amount calculator;
an aperture value setting device for setting an aperture value before a photographing operation;
a decision making device for deciding if a set aperture value set by said aperture value setting device is larger than a predetermined aperture value;
and
a flash control circuit for causing said main flash without said preliminary flash when it is decided by said decision making device that said set aperture value is larger than said predetermined aperture value, and for causing said main flash based on said preliminary flash when it is decided by said decision making device that said set aperture value is less than said predetermined aperture value.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/370,741Filed 10 Jan 1995 · division
Priority: JP 1-2043007 Aug 1989
Granted: 12 Mar 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G02B 7/34
Systems for automatic generation of focusing signals: using different areas in a pupil plane
G03B 7/08
Control of exposure by setting shutters, diaphragms or filters, separately or conjointly: control effected solely on the basis of the response, to…
G03B 7/09974
In mirror-reflex cameras: using the film or shutter as sensor light reflecting member
G03B 7/09979
Through the lens [TTL] measuring: multi-zone light measuring

Family

Serial560,745Parent of this division · filed 31 Jul 1990
Serial47,478Parent of this division · filed 19 Apr 1993
US 5,231,448 AParent of this division · filed 27 Jul 1993
US 5,400,112 AParent of this division
US 5,499,075 AThis patent

From the US filing history. Foreign family members aren’t listed.