JPS5930124U

JPS5930124U - safety circuit

Info

Publication number: JPS5930124U
Application number: JP1983018769U
Authority: JP
Inventors: 恒川　十九一; 哲也田口
Original assignee: キヤノン株式会社
Priority date: 1983-02-10
Filing date: 1983-02-10
Publication date: 1984-02-24

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) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

第１図は光起電力型の受光素子を用いた測光回路の一実
施例を示す回路図、第２図は第１図示の測光回路の出力
特性を示す特性図、第３図は第１図示の測光回路の他の
実施例を示す回路図、第４図は第３図示の測光回路の出
力特性を示す特性図、第５図は本考案に係る露出制御回
路の安全回路の一実施例を示すブロック線図、第６図は
第５図に示したブロック線図の他の実施例を示すブロッ
ク線図、第７図は第５図示のブロック線図の具体的な構
成を示す回路図である。ＰＤ・・・・・・受光素子、ＡＭ・・・・・・演算増幅
器、ＣＡ・・・・・・浮遊容量、１０１・・・・・・測
光回路、１０４・・・・・・給電制御回路、１０５・・
・・・・始動制御回路、１０８・・・・・・アンドゲー
ト、２２９・・・・・・トランジスター。１　　　　　　１４− ■ 蜀　３　図上　　１　　　　＝、−、、ｌ、　　　ｌ　＋　ｖ　−
「−７４′を製０藝　７　図Fig. 1 is a circuit diagram showing an example of a photometry circuit using a photovoltaic type light receiving element, Fig. 2 is a characteristic diagram showing the output characteristics of the photometry circuit shown in Fig. 1, and Fig. 3 is a diagram showing the output characteristics of the photometry circuit shown in Fig. 1. FIG. 4 is a characteristic diagram showing the output characteristics of the photometry circuit shown in FIG. 3, and FIG. 5 is a circuit diagram showing an example of the safety circuit of the exposure control circuit according to the present invention. 6 is a block diagram showing another embodiment of the block diagram shown in FIG. 5, and FIG. 7 is a circuit diagram showing a specific configuration of the block diagram shown in FIG. 5. be. PD: light receiving element, AM: operational amplifier, CA: stray capacitance, 101: photometric circuit, 104: power supply control circuit , 105...
...Start control circuit, 108...AND gate, 229...Transistor. 1 14- ■ Shu 3 On the diagram 1 =, -,, l, l + v -
"-74' is made 0 art 7

Claims

[Scope of utility model registration request]

An exposure control device comprising a photometric circuit that logarithmically compresses the output of a light receiving element connected between input terminals of an operational amplifier using a logarithmic compression element, and performs exposure control based on the output of the photometric circuit, wherein the output of the photometric circuit is The camera start control circuit includes a gate circuit into which a signal associated with the release operation and a signal associated with the release operation are input, and a camera start control circuit equipped with a magnet that performs the camera release operation using the output signal from the gate circuit. When the output of the photometry circuit becomes abnormal, the camera start control circuit is inactivated by the first signal output from the gate circuit, and when the output of the photometry circuit becomes normal, the gate circuit is inverted. A safety circuit characterized in that it outputs a second signal and operates a camera start control circuit by the second signal.