JPS5749265A - Line sensor - Google Patents

Abstract

PURPOSE:To improve resolution, by a method wherein the distance between a photoconductive film uniting a photoelectric transducing part and a light incident part and the surface of an original is made small, and the light reflected from the original surface is expelled while the light entering the inside of the original is received. CONSTITUTION:On a part of a glass plate 1, stripe-shaped electrodes 3 are provided in parallel to each other through a light-blocking layer 2. In the part corresponding to the layer 2, a photoconductive film 4 and a transparent electrode 5 are piled up crossing the electrode 3 to form each of sensors 6 and coated with a hard transparent thin film 8. A through hole 9 is provided in each electrode 3 so as to be close to the corresponding sensor 6, to define a light incident part 10. In this case, the total film thickness (t) of the film 4, the electrode 5 and the film 8 is selected so as to be t<5mum, and the pitch P between the sensors 6 and the distance between each sensor 6 and each light incident part 10 are selected so as to be d<P<=200mum. Moreover, the sensors 6 and the light incident parts 10 are arranged so as to be perpendicular to the scanning direction. By said constitution, with the sensors 6 contacted closely to the original surface 12, light 13 is projected to the light incident parts 10, and the inner light 13' having reached the part below each sensor 6 is received as a signal. Thereby, a signal of high resolution can be obtained, and the need for a lens is eliminated, so that the line sensor is made more compact.