A device that completes image decomposition and optical signal conversion. Image decomposition is the process of decomposing a complete image into a number of independent pixels (the smallest unit that constitutes a television image). Generally speaking, the more pixels, the clearer the image. Each pixel is represented only with a single color and brightness. The camera device converts the light signals from each pixel in the image into corresponding electrical signals, and transmits it to the output in a certain order. Camera devices divide the camera tubes and solid (semiconductor) camera devices two major categories.
① camera tubes, electron beam devices, but also divided into image tubes, photoelectric multiplication of image tubes, ultra-positive analysis of the image tubes and photo-camera tubes and so on. The new camera uses compact lead oxide photoelectric camera tubes. All kinds of camera tubes have a vacuum glass shell, which is fitted with a target surface and an electron gun. The camera is imaged through the window on the glass shell, and the illumination distribution of the target surfaces is transformed into the corresponding potential distribution by using the photoelectric emission effect of the target surface or the optical conductivity effect, and the optical image becomes an electric image. Driven by the external yoke coil, the electron beam scans the target by point by line, outputting the potential signals of each pixel on the scanning path.
② solid camera device, a new type of charge coupling device (CCD). Hundreds of thousands of device units arranged into an array, the surface has photosensitive characteristics. The scene is imaged in the array, and the charge quantity and illuminance are proportional to the storage of each unit. By using the clock pulse and shift control signal, the signal of each unit of the array can be shifted in a certain order, and the image signal of intensity varies with time.
The amplifier enlarges the faint signal output from the camera device to the specified amplitude video amplifier. In order to ensure good Snr, the preset is required to have the smallest noise coefficient.