| 摘要 |
PURPOSE:To detect each color light in a time series manner, by using one acousto- optical element to drive the same while changing frequency and converting diffracted light to an electric signal to take out said signal in synchronous relation to the change in driving frequency. CONSTITUTION:A manuscript is irradiated with white light 4 and the reflected light is incident to an acousto-optical element 27 at a black angle theta with respect to a wave front. The element 27 is driven through the transducer 28 of an end surface and diffracted light is converged by a converging lens to be received by CCD 33 and the transmitted light is blocked by a plate 32. The driving frequencies inherent to the three primary colors are respectively generated by a DC power source 39 and VCO 38 and converted to frequency signals FR, FG, FB having specific pulse widths on the basis of the pulse signals TR, TG, TB from an operational processing apparatus 24 by converters 37 and, by the gate signal G relating to the color separation of incident light 26, an ultrasonic signal is propagated to the element 27 for a specific time through a directional coupler 35. When the incident light 26 contains monochromatic light, said light is successively received as diffracted light 29 by a light receiver 33 and the operational processing apparatus 24 records luminous intensity in synchronous relation to the driving of the element and feed the manuscript 5 to detect the hue data of the next minute part. |
