JPS614930U

JPS614930U - camera photometry device

Info

Publication number: JPS614930U
Application number: JP1985073237U
Authority: JP
Inventors: 十九一恒川; 哲也田口; 文夫伊藤; 勲針ケ谷
Original assignee: キヤノン株式会社
Priority date: 1985-05-16
Filing date: 1985-05-16
Publication date: 1986-01-13
Also published as: JPS6111698Y2

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

第１図は受光素子、分光感度補正用フィルタ及び付加光
源の分光特性図、第２図は本考案の受光装置を用いたカ
メラの一実施例を示す構成図、第３図は第２図に示すカ
メラの露出制御回路の一例を示す回路図、第４図は第３
図に示す回路の他の例を示す回路図、第５図は第３図に
示す回路の更に他の例を示す回路図である。３・・・レンズシャッタ、３′・・・フォー力ルプレー
ンシャッタ、４・・・フイルム、５・・・シリコンフォ
トダイオード、６・・・フィルター、７・・・発光ダイ
オード、１０・・・演算増巾器、１１・・・対数圧縮用
タイオード、１２．１３・・・浮遊容量、２２・・・ス
イッチ、２６・・・シュミットトリガ回路、２７・・・
トランジスタ、３１・・・トランジスタ。Fig. 1 is a spectral characteristic diagram of the light receiving element, spectral sensitivity correction filter, and additional light source, Fig. 2 is a configuration diagram showing an example of a camera using the light receiving device of the present invention, and Fig. 3 is the same as Fig. 2. A circuit diagram showing an example of the exposure control circuit of the camera shown in FIG.
FIG. 5 is a circuit diagram showing still another example of the circuit shown in FIG. 3. FIG. 3...Lens shutter, 3'...Four force plane shutter, 4...Film, 5...Silicon photodiode, 6...Filter, 7...Light emitting diode, 10...Calculation Amplifier, 11... Logarithmic compression diode, 12.13... Stray capacitance, 22... Switch, 26... Schmitt trigger circuit, 27...
Transistor, 31...transistor.

Claims

[Scope of utility model registration request]

(1) Place the light-receiving element near the front of the film surface,
In a direct metering camera photometer that directly measures the reflected light from the film surface of the subject, a spectral sensitivity correction filter is installed in the direction of the film surface of the light receiving element connected between the input terminals of the operational amplifier of the photometry circuit. At the same time, by arranging between the filter and the light receiving element a light emitting light source for supplying bias light having spectral emission energy characteristics within the sensitivity wavelength range of the light receiving element and outside the transmission wavelength range of the filter. The reflected light is irradiated onto the light receiving element via the filter, the light from the light source is irradiated onto the light receiving element and does not leak outside the filter, and a supply circuit is further provided to supply a via current to the light source at the initial stage of photometry. A photometric device for a camera, characterized in that:

(2) Utility model registration Claim 1, wherein the supply circuit has a switching element, and the switching element is controlled by the output of the operational amplifier to activate the supply circuit. Photometric device.

(3) Utility model registration Claim 1, wherein the supply circuit includes a time constant circuit and a switching element;
The switching element is controlled by a time constant circuit, and is turned on for a certain period of time at the beginning of photometry to enter a power supply state.