Patent US 5,200,792

For obtaining distance information between an image pickup device (10) and an object (11) illuminated by a monochromatic beam selected by a diffraction grating (18) from an optical beam generated by an optical beam generator (27), a distance information obtaining device comprises an activating device (33) for simultaneously activating the beam generator and the image pickup device a predetermined time duration so that the optical beam generator generates an optical beam while activated and so that the image pickup device picks up an optical image of the object to produce a picture signal while activated. A processing unit (21) processes the picture signal into a processed signal representative of the distance information. The optical beam may have an intensity which is higher that that of environmental light of the object. The predetermined time duration may be an instantaneous time duration. The beam generator may generate a flash of light as the optical beam. Alternatively, the beam generator may comprise a light source for generating a white light as the optical beam and a light source shutter for supplying the white light to the diffraction grating only when the light source shutter is activated. As a further alternative, the image pickup device may comprise a television camera and a pickup shutter for supplying the optical image of the object of the camera only when the pickup shutter is activated.