# US 4,829,371 A · Film reading apparatus which reads an unexposed portion of a film to determine its type > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,829,371 A - Document ID: US4829371A - Status: Granted - Kind: A - Application number: 06/841,625 - Filed: 1986-03-20 - Granted: 1989-05-09 - Earliest claimed: 1985-03-23 - Assignees: Canon Kabushiki Kaisha - Inventors: Akira Hiramatsu; Takashi Kawabata; Hitoshi Mukohjima; Koichi Washisu - Web page: https://patentgrep.com/patent/US4829371A ## CPC - H04N 1/40062: {Discrimination between different image types, e.g. two-tone, continuous tone} - H04N 1/00795: {Reading arrangements (details of scanning heads H04N1/024; scanning arrangements therefor H04N1/04)} - H04N 1/00806: {According to type of the original, e.g. colour paper or transparency, or reading a plurality of different types of original} - H04N 1/6094: {depending on characteristics of the input medium, e.g. film type, newspaper} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A color scanner for converting color data of a color original (e.g., a photographic film) into an electrical signal, includes a level comparator for discriminating the type of film (e.g., color negative vs. color positive, color vs. monochrome, type of color negative) in accordance with output signals, e.g., color component signals, from a sensor (i.e., based on a light transmittance of an unexposed portion of the film). The output from the level comparator is supplied to an accumulation time control block through a register, a selector, and the like. The accumulation time control block corrects the electrical signal based on the discrimination result from the level comparator irrespective of the type of film, so that an accumulation time of the sensor is changed by changing a bias voltage applied thereto. ## Claims ### Claim 1 A film reading apparatus comprising: extracting means for color-separating film document to extract a plurality of color component signals; discriminating means for discriminating the type of the film document by using a color component signal relating to an unexposed portion of the film document output by said extracting means; and control means for controlling the signal level of a color component signal relating to an exposed portion of the film document in accordance with the discrimination result obtained by said discriminating means; wherein said discriminating means discriminates whether the film document is a color negative film or a color positive film. ### Claim 2 A film reading apparatus comprising: extracting means for color-separating a film document to extract a plurality of color component signals; discriminating means for discriminating the type of the film document by using a color component signal relating to an unexposed portion of the film document output by said extracting means; and control means for controlling the signal level of a color component signal relating to an exposed portion of the film document in accordance with the discrimination result obtained by said discriminating means; wherein said discriminating means discriminates whether the film document is a color film or a monochrome film. ### Claim 3 A film reading apparatus comprising: extracting means for color-separating a film document to extract a plurality of color component signals; discriminating means for discriminating the type of the film document by using a color component signal relating to an unexposed portion of the film document output by said extracting means; and control means for controlling the signal level of a color component signal relating to an exposed portion of the film document in accordance with the dicrimination result obtained by said discriminating means; wherein said control means inverts the level of the color component signal relating to the exposed portion of the film document when said discriminating means discriminates that the film document is a negative film. ### Claim 4 A film reading apparatus comprising: extracting means for color-separating a film document to extract a plurality of color component signals; discriminating means for discriminating the type of the film document by using a color component signal relating to an unexposed portion of the film document output by said extracting means; and control means for controlling the signal level of a color component signal relating to an exposed portion of the film document in accordance with the discrimination result obtained by said discriminating means; wherein said control means removes a bias signal, which depends upon the type of (the) film document discriminated by said discriminating means, form the color component signal relating to the exposed portion of the film document. ### Claim 5 (depends on 1, 2, 3, 4) An apparatus according to claim 1, 2, 3 or 4, wherein said discriminating means discriminates the type of the film document in accordance with the signal level of each of said plurality of color component signals. ### Claim 6 (depends on 1, 2, 3, 4) An apparatus according to claim 1, 2, 3 or 4, wherein said control means controls a gain for the color component signal relating to the exposed portion of the film document in accordance with the type of (the) film document discriminated by said discriminating means. ### Claim 7 (depends on 1, 2, 3, 4) An apparatus according to claim 1, 2 ,3 or 4, further comprising means for detecting whether or not a color component signal output by said extracting means is a color component signal relating to the unexposed portion of the film document (or not). ### Claim 8 (depends on 1, 2, 3, 4) An apparatus according to claim 1, 2, 3 or 4, wherein the plurality of color component signals are R, G and B color component signals. ### Claim 9 (depends on 2, 4) An apparatus according to claim 2 or 4, wherein, when the film document is a color negative film, said discriminating means discriminates the type of the color negative film.