# US 4,724,323 A · Image line sensor unit, photosensors for use in the sensor unit and method of making the photosensors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,724,323 A - Document ID: US4724323A - Status: Granted - Kind: A - Application number: 06/781,733 - Filed: 1985-09-30 - Granted: 1988-02-09 - Earliest claimed: 1984-10-04 - Assignees: Canon Kabushiki Kaisha - Inventors: Masaki Fukaya; Toshiyuki Komatsu; Tatsumi Shoji; Masaru Kamio; Nobuyuki Sekimura - Web page: https://patentgrep.com/patent/US4724323A ## CPC - H04N 1/0312: {using an array of optical fibres or rod-lenses} - H04N 1/0315: {using photodetectors and illumination means mounted on separate supports or substrates or mounted in different planes} - H04N 1/0318: {Integral pick-up heads, i.e. self-contained heads whose basic elements are a light-source, a lens array and a photodetector array which are supported by a single-piece frame} - H04N 1/1931: {with scanning elements electrically interconnected in groups} - H10F 39/191: {Photoconductor image sensors} - H10F 39/8053: {Colour filters} - H04N 2201/03112: Light source - H04N 2201/03141: Photodetector lens - H04N 2201/03145: Photodetector - H04N 2201/03158: Heat radiator - H04N 2201/03179: Frame - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract A photosensor comprising a photoconductive layer provided on a substrate. The layer contains amorphous silicon. At least a portion of the layer has a refractive index varying continuously through the thickness of the layer. The refractive index of the layer is 3.2 or less at a wavelength of 6,328 .ANG. in the vicinity of the surface of the substrate. A pair of electrodes are provided in electrical contact with the photoconductive layer. A photoreceptor is also provided, part of which is constituted by the spacing between the electrodes of the pair. ## Claims ### Claim 1 A photosensor comprising: a photoconductive layer provided on a substrate, said layer including amorphous silicon, at least a portion of said layer having a refractive index varying continuously through the thickness thereof, the refractive index of the layer being 3.2 or less at a wavelength of 6,328 .ANG. near a surface of said substrate; a pair of electrodes provided in electrical contact with said photoconductive layer; and a photoreceptor. ### Claim 2 (depends on 1) A photosensor according to claim 1, wherein said photosensor further includes a color filter at a position corresponding to said photoreceptor. ### Claim 3 (depends on 2) A photosensor according to claim 2, wherein said color filter includes a coloring matter layer formed by evaporation. ### Claim 4 (depends on 1) A photosensor according to claim 1, wherein the thickness of said at least a portion in which the refractive index of said photoconductive layer near said surface of said substrate is 3.2 or less at a wavelength of 6,328 .ANG. is 1,000 .ANG. or less. ### Claim 5 (depends on 1) An photosensor according to claim 1, wherein said pair of electrodes are provided at a predetermined spacing on the side of the same surface of said photoconductive layer. ### Claim 6 (depends on 1) A photosensor according to claim 1, wherein said amorphous silicon includes hydrogenated amorphous silicon. ### Claim 7 (depends on 1) A photosensor according to claim 1, wherein said photoconductive layer includes hydrogen atoms. ### Claim 8 (depends on 1) A photosensor according to claim 1, wherein said pair of electrodes each has a comb tooth type pattern. ### Claim 9 (depends on 1) A photosensor according to claim 1, wherein one of said electrodes of said pair is electrically provided in common among respective photosensors. ### Claim 10 An image line sensor unit comprising: an array of photosensors, each including: a photoconductive layer provided on a substrate, said layer including amorphous silicon, at least a portion of said layer having a refractive index varying continuously through the thickness thereof, the refractive index of the layer being 3.2 or less at a wavelength of 6,328 .ANG. near a surface of said substrate; a pair of electrodes provided in electrical contact with said photoconductive layer; and a photoreceptor; and a light source for illuminating an original document. ### Claim 11 (depends on 10) An image line sensor unit according to claim 10, wherein said light source includes an array of LED light sources. ### Claim 12 (depends on 3) An image line sensor unit according to claim 3, further including a plurality of LED light sources. ### Claim 13 (depends on 10) An image line sensor unit according to claim 10, wherein said light source includes a fluorescent lamp. ### Claim 14 (depends on 2) An image line sensor unit according to claim 2, further including a focusing optically imaging array provided in the optical path between an original document and said array of said photosensors. ### Claim 15 (depends on 10) An image sensor unit according to claim 10, further including matrix drive circuit means for matrix driving each of said photosensors. ### Claim 16 (depends on 10) An image line sensor unit according to claim 10, wherein said array of photosensors are divided into a plurality of block units, each including a predetermined number of said photosensors. ### Claim 17 (depends on 10) An image line sensor unit according to claim 10, further including storage means for storing the output signals from the photosensors, and switching means for taking out the stored signals sequentially. ### Claim 18 (depends on 2) An image line sensor unit according to claim 2, further including heat dissipation means. ### Claim 19 An image reader comprising an image line sensor unit which comprises: an array of photosensors, each including: (a) a photoconductive layer provided on a substrate, said layer including amorphous silicon, at least a portion of said layer having a refractive index varying continuously through the thickness thereof, the refractive index being 3.2 or less at a wavelength of 6,328 .ANG. near a surface of said substrate; (b) a pair of electrodes provided in electrical contact with said photoconductive layer; and (c) a photoreceptor; and a light source for illuminating an original document.