| 摘要 |
<p>A selector slide is manually displaced by the user from an inoperative setting to a series of operative settings for adjusting exposure-aperture size. When the selector slide leaves inoperative setting, it closes a main power-connect switch connecting the camera's various circuits to the camera battery. The selector slide is provided with a pushbutton which the user depresses to initiate various control or test functions, some of which are performed only in certain settings of the selector slide, others of which are performed within all settings to which the user might move the slide in the course of adjusting aperture size, or another exposure parameter. Examples of such functions are activating a user-oriented scene-light-sufficiency indicator circuit and a circuit which indicates the state of the camera battery. Certain settings of the selector slide are reserved for flash-exposure use, and in these settings the user employs the slide to select subject-distance, and thereby indirectly the exposure-aperture size; in the flash-exposure settings, the slide also closes an enablement switch which readies a flash unit for operation. In this way, essentially only the slide and the pushbutton on it can be used to vary exposure parameters, select operating modes and exposure-parameter values appropriate for such modes, and also initiate test or monitoring operations. Preferably, a single conductive spring contact, slid by the slide and depressed by the pushbutton, engages a plurality of contact strips in varying combinations depending upon the setting of the slide and whether or not the pushbutton is depressed, to cause such contact strips, in their various combinations, to act as various combinations of electrical switches.</p> |
