Abstract: An image input apparatus, or "scanner," capable of adjusting the focal point of an image-forming optical system and pre-scanning the same portion of an original document for various focal points of the image-forming optical system. The various pre-scan images are displayed side-by-side on a display device so that an operator can compare images and select an appropriate focal point. The scanner includes an image-forming optical system which forms an image of an original source, an image pickup unit, positioned so as to correspond with the image-forming optical system, for sensing the image formed by the image-forming optical system, an adjustment mechanism for adjusting the focus of the image-forming optical system, and a display device, interfaced to the image pickup unit, for displaying the image sensed by the image pickup unit.

Abstract: A color video camera white balance control apparatus including light sensors for sensing the color temperature of a light illuminating an object. The apparatus has an automatic follow-up mode for automatically effecting the white balance adjustment by controlling the gains of the color signal amplifiers of the color video camera in accordance with the detection outputs of the light sensors and a standard mode for controlling the gains of the amplifiers in accordance with preset values irrespective of the output values of the lights sensors, and also the apparatus is so designed that the standard mode is selected automatically or manually upon indication of a warning when the luminous intensity of the illuminating light becomes lower than a fixed level (or when the light sensor output values become lower than a certain value).

Abstract: A white balance adjusting apparatus for a color television camera detects the color temperature of an illuminating light of an object for shooting and effects the gain balance adjustment of a chromaticity signal circuit in accordance with the detection output. The white balance adjusting apparatus includes at least one attenuating circuit for suitably attenuating the detection output when desired and thereby suppressing the gain balance adjustment during outdoor shooting as compared to indoor shooting.

Abstract: In a color television camera of the type in which the white balance is subjected to automatic follow-up adjustment during the shooting in accordance with the color temperature of an object illuminating light detected by light sensors provided independent of the imaging means, the adjusted condition of the white balance is maintained constant as desired. The TV camera includes change-over switch for switching the white balance control mode between the automatic follow-up mode and the memory mode, memory means for locking the white balance which has been adjusted automatically in the then current condition in response to the change-over to the memory mode, and a controller whereby when the shooting preparatory operation is started with the memory mode being selected the white balance control mode is always changed over to the automatic follow-up mode first thereby effecting the white balance adjustment. Particularly, this change-over to the automatic mode occurs when the power source is coupled to the camera.