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公开(公告)号：US3623790A
公开(公告)日：1971-11-30
申请号：US3623790D
申请日：1969-12-31
CPC分类号： G02B27/40
摘要： In those optical systems in which a lens is moved parallel to the film to either record information on the film or read information from the film, any variation in the distance between the film and the lens will degrade the optical focus. The disclosed embodiment of the present invention is a system for maintaining the distance from a lens to a film in such an optical arrangement constant. A metallic member is supported on the lens housing and the film is supported on a metallic table. The lens housing is mounted for movement by means of a servomotor toward and away from the film. The capacitance between the metallic member and the metallic table is sensed and a voltage proportional thereto is supplied to drive the servomotor to position the lens housing to maintain the capacitance constant.
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公开(公告)号：US3633044A
公开(公告)日：1972-01-04
申请号：US3633044D
申请日：1969-12-31
发明人： BUCKSTAD STANLEY A
摘要： In the exposure of film with a CRT, for example, the resulting recorded information density on the film is not proportional to the amplitude of the video signal applied to the CRT. That is, if a linear ramp function is applied to a CRT for the purpose of exposing film, the resulting exposed density on the film will be an exponential function. This response is defined as the gamma of the film and produces an error in recording an image on film. The disclosed embodiment of this invention is a circuit for correcting the error which results during the exposure of a photographic film or in the transmission of light through a layer of phosphor, such as found on the face of a CRT, due to the gamma characteristic thereof. The circuit is formed of an amplifier having a resistance feedback and a second resistance connecting the video signal to an input of the amplifier. In one embodiment, the input resistance is formed of a F.E.T., and in a second embodiment the feedback resistance is formed of an F.E.T. The operating characteristics of the F.E.T. establish the amount of correction provided to the video signal by the circuit. The operating characteristics of the F.E.T. in both embodiments of the invention can be varied by applying the video signal to a gate electrode of that F.E.T.
摘要翻译： 例如，在用CRT曝光胶片时，胶片上产生的记录信息密度与施加于CRT的视频信号的幅度成正比。 也就是说，如果为了曝光胶片而将CRT线性斜坡函数应用于CRT，则膜上产生的曝光密度将是指数函数。 该响应被定义为胶片的伽马，并且在胶片上记录图像时产生错误。 本发明公开的实施例是用于校正在照相胶片的曝光期间或由于其伽马特性引起的透过荧光体层（例如在CRT的表面上）发出的光的错误的电路 。 电路由具有电阻反馈的放大器和将视频信号连接到放大器的输入端的第二电阻形成。 在一个实施例中，输入电阻由F.E.T.形成，并且在第二实施例中，反馈电阻由F.E.T.形成。 F.E.T.的操作特性 建立由电路提供给视频信号的校正量。 F.E.T.的操作特性 在本发明的两个实施例中，可以通过将视频信号施加到该F.E.T.的栅电极来改变。
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