Electric shutter operating circuit专利检索-测光表摄影专利检索查询-专利查询网

Electric shutter operating circuit

阅读：543发布：2021-11-24

专利汇可以提供Electric shutter operating circuit专利检索，专利查询，专利分析的服务。并且An external electromotive element is disposed in front of the camera. An internal electromotive element is disposed in a position to receive the light transmitted through the lens, for through-the-lens metering. A first capacitor is charged from a source of constant voltage through the internal and external electromotive elements to store a voltage representative of the ratio of externally and internally measured light. A switch, interlocked with the shutter release button connects the output of the first capacitor to the one input of a differential amplifier and connects the external electromotive element, with its polarity reversed, to the second input of the differential amplifier concurrently with the opening of the shutter. A second capacitor is charged in accordance with the output from the differential amplifier and a shutter control circuit is responsive to a predetermined terminal voltage of the second capacitor to close the shutter.，下面是Electric shutter operating circuit专利的具体信息内容。

权利要求

1. An electric shutter operating circuit for a camera comprising an external photosensitive electromotive element (P2) disposed in front of the body of said camera; an internal photosensitive electromotive element (P1) disposed in position to receive light transmitted through the lens of said camera; a source of constant voltage (E); a first capacitor (C1); switching means (S, S4) having a first switching position connecting said internal and external electromotive elements (P1, P2) in series opposition and charging said first capacitor (C1) from said source of constant voltage (E) through said internal and external electromotive elements (P1, P2) which are connected in series opposition; a differential amplifier (A1) having first and second inputs (Q1, Q2) detecting the balanced condition of said first and second inputs, said switching means having a second switching position and also connecting the output of said first capacitor (C1) to said first input (Q1) of said differential amplifier (A1), and connecting said external electromotive element, with its polarity reversed, between the second input (Q2) and the output of said differential amplifier (A1), said switching means changing from said first to said second operated position concurrently with the opening of said shutter of said camera; a second capacitor (C2); means (T2) to charge said capacitor (C2) in accordance with the output from said differential amplifier (A1), and a shutter control circuit (F) responsive to a pre-determined terminal voltage of said second capacitor (C2) to close the shutter.

2. The electric shutter operating circuit as described in claim 1 which further comprises a diode (D), and a transistor (T1) connected to pass current through said diode, said transistor (T1) being connected to and controlled by the output from said differential amplifier (A1), said switching means (S, S4); when in said second position, establishing a connection to apply the difference between the output of said external electromotive element (P2) and the voltage drop across said diode (D) to said second input (Q2) of said differential amplifier (A1).

3. The electric shutter operating circuit as described in claim 2 wherein said differential amplifier (A1) includes a pair of cascade connected field effect transistors (FET1, FET2), the gate electrode of one of the field effect transistors (FET1) being connectable to said first capacitor (C1) through said switching means and the gate electrode for the other field effect transistor (FET2) being connectable to receive said difference voltage between the output of said external electromotive element (P2) and the voltage drop across said diode (D2).

4. The electric shutter operating circuit according to claim 1 wherein said switching means has a neutral position besides the two operating positions, said switching means being interlocked with the shutter release button of the camera such that when the shutter release button is depressed slightly, said switching means is operated to one operating position to connect said first capacitor (C1) to said source of constant voltage (E) through said internal and external electromotive elements (P1, P2), and when the shutter release button is depressed further, said switching means is operated to the other operating position to Connect said capacitor (C1) to said first input (Q1) of said differential amplifier (A1) and to concurrently connect the inverted external electro-motive element (P2) with reverse polarity between the output and said second input (Q2) of said differential amplifier (A1).

5. Circuit according to claim 4, wherein the source of constant voltage has a controllable value, the voltage value being changeable to provide an adjustment to the charge on the capacitor (C1) and permit setting of the shutter in accordance with various film sensitivities.

说明书全文

相关专利内容

标题	发布/更新时间	阅读量
一种拍摄调整方法、装置、电子设备及存储介质	2020-05-08	444
基于多点协同的预制装配式构件拼缝宽度测量校准方法	2020-05-08	566
非球面磨削圆弧金刚石砂轮三维形状误差在位精密测量方法	2020-05-13	877
一种转盘式单色LED光源系统	2020-05-08	880
一种摄影灯精确调校色温的方法及装置	2020-05-13	129
一种共轴光学镜头的非接触式实时精密调装方法	2020-05-11	588
一种自动调节目标场景照明水平的方法及智能照明控制系统	2020-05-11	740
指纹感测装置	2020-05-12	730
红外光发射与收集装置	2020-05-12	326
超光谱线扫描3D测量装置	2020-05-11	881

高效检索全球专利

专利汇是专利免费检索,专利查询,专利分析-国家发明专利查询检索分析平台，是提供专利分析，专利查询，专利检索等数据服务功能的知识产权数据服务商。

我们的产品包含105个国家的1.26亿组数据，免费查、免费专利分析。

申请试用

分析报告

专利汇分析报告产品可以对行业情报数据进行梳理分析，涉及维度包括行业专利基本状况分析、地域分析、技术分析、发明人分析、申请人分析、专利权人分析、失效分析、核心专利分析、法律分析、研发重点分析、企业专利处境分析、技术处境分析、专利寿命分析、企业定位分析、引证分析等超过60个分析角度，系统通过AI智能系统对图表进行解读，只需1分钟，一键生成行业专利分析报告。

申请试用

测光表热门专利

热门分类

Electric shutter operating circuit

该功能需要专业版企业版VIP权限，您可以：