# US 7,408,180 B2 · Compensation apparatus for image scan > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,408,180 B2 - Document ID: US7408180B2 - Status: Granted - Kind: B2 - Application number: 11/618,147 - Filed: 2006-12-29 - Published: 2007-07-05 - Granted: 2008-08-05 - Earliest claimed: 2001-08-03 - Assignees: Transpacific IP, Ltd. - Inventors: Chih-Wen Huang; Cheng-Kuei Chen; Jen-Shou Tseng - Web page: https://patentgrep.com/patent/US7408180B2 ## CPC - H04N 1/0473: {in subscanning direction, e.g. picture start or line-to-line synchronisation} - H04N 1/1017: {the main-scanning components remaining positionally invariant with respect to one another in the sub-scanning direction} - H04N 1/193: using electrically scanned linear arrays {, e.g. linear CCD arrays} - H04N 2201/02439: Positioning method - H04N 2201/0402: Arrangements not specific to a particular one of the scanning methods covered by groups H04N1/04 - H04N1/207 - H04N 2201/04713: Details of the detector arrangement, e.g. non-standard position, optical details (H04N2201/04712 takes precedence) - H04N 2201/0472: on or adjacent the sheet support - H04N 2201/04743: by detecting the image directly - H04N 2201/04749: Detecting position relative to a gradient, e.g. using triangular-shaped masks, marks or gratings - H04N 2201/04787: by changing or controlling the addresses or values of pixels, e.g. in an array, in a memory, by interpolation - H04N 2201/04793: using stored control or compensation data, e.g. previously measured data - H04N 2201/04794: Varying the control or compensation during the scan, e.g. using continuous feedback or from line to line - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A compensation apparatus for image scan, applied to an optical scanner with a platform, on which an object to be scanned is disposed. The optical scanner has a photosensitive apparatus with a set of scan photosensitive devices and a storage apparatus. When the object is scanned by the set of scan photosensitive devices, a scanned image is obtained and saved in the storage apparatus temporarily. The compensation apparatus has a set of calibration boards, a set of calibration photosensitive devices and an image processor. The set of calibration boards has two calibration boards located at two sides of the platform. The set of calibration photosensitive devices is located at two sides of the set of scan photosensitive device. The image processor is used to extract and compare the calibrated image, so as to adjust the scanned image. ## Claims ### Claim 1 A compensation apparatus comprising: a set of calibration boards, comprising two calibration boards approximately located at two sides of a platform, where the calibration boards provide a pattern that varies along one or more axial directions of the compensation apparatus; a set of calibration photosensitive devices, approximately located at two sides of a set of scan photosensitive devices, the set of calibration photosensitive devices configured to obtain a set of calibrated images by detecting the calibration boards; and an image processor configured to calculate an optical path deviation to adjust the scanned image, and wherein the image processor is further configured to compare the calibrated images to calculate the optical path deviation based at least in part on a variation of the pattern in one or more of the axial directions. ### Claim 2 (depends on 1) The compensation apparatus according to claim 1, wherein the set of calibration photosensitive devices comprises a plurality of calibration photosensitive devices arranged in a L×K array at two sides of the set of scan photosensitive devices, and wherein L and K are integers larger than 1. ### Claim 3 (depends on 2) The compensation apparatus according to claim 2, wherein the set of scan photosensitive devices comprises a plurality of scan photosensitive devices, and wherein the calibration photosensitive devices have a dimension smaller than that of the scan photosensitive devices. ### Claim 4 (depends on 1) The compensation apparatus according to claim 1, wherein the calibration boards have a strip shape and a width increasing along a scanning direction. ### Claim 5 (depends on 1) The compensation apparatus according to claim 1, wherein the calibration boards have widths decreasing along a scanning direction. ### Claim 6 (depends on 1) The compensation apparatus according to claim 1, wherein the image processor is further configured to: calculate the optical path deviation in an x-axis according to a displacement of the calibrated images detected by the set of calibration photosensitive devices; calculate the optical path deviation in a y-axis according to the displacement of the calibrated images detected by the set of calibration photosensitive devices; and calculate the optical path deviation in a z-axis according to the displacement of the calibrated images detected by the set of calibration photosensitive devices. ### Claim 7 (depends on 6) The compensation apparatus according to claim 6, wherein the image processor is further configured to calculate the optical path deviation twisting around the y-axis according to the optical path deviation in the z-axis; and calculate the optical path deviation twisting around the z-axis according to the optical path deviation in the y-axis. ### Claim 8 (depends on 1) The compensation apparatus according to claim 1, wherein a magnitude and direction of the optical path deviation is calculated based on a displacement of the calibrated images in one or more of the axial directions. ### Claim 9 A compensation apparatus comprising: a calibration board, approximately located at one side of a platform, the calibration board comprised of a pattern that varies along a direction of image processing; a set of calibration photosensitive devices, approximately located at one side of a set of scan photosensitive devices, configured to obtain a calibrated image by detecting the calibration board; and an image processor configured to calculate an optical path deviation based at least in part on the calibrated image to adjust the scanned image, and wherein the image processor is further configured to compare the calibrated image to calculate the optical path deviation based at least in part on a variation of the pattern in the direction of image processing. ### Claim 10 (depends on 9) The compensation apparatus according to claim 9, wherein the set of calibration photosensitive devices comprises a plurality of calibration photosensitive devices arranged at two sides of the set of scan photosensitive devices in an L×K array, wherein L and K are integers larger than 1. ### Claim 11 (depends on 9) The compensation apparatus according to claim 9, wherein the set of scan photosensitive devices comprise a plurality of scan photosensitive devices, and wherein the calibration photosensitive devices have a dimension smaller than that of the scan photosensitive devices. ### Claim 12 (depends on 9) The compensation apparatus according to claim 9, wherein the calibration boards have a strip shape and a width increasing along a scanning direction. ### Claim 13 (depends on 9) The compensation apparatus according to claim 9, wherein the calibration boards have a strip shape and a width decreasing along a scanning direction. ### Claim 14 (depends on 9) The compensation apparatus according to claim 9, wherein the image processor is further configured to: calculate the optical path deviation in an x-axis according to a displacement of the calibrated image detected by the set of calibration photosensitive devices; calculate the optical path deviation in a y-axis according to the displacement of the calibrated image detected by the set of calibration photosensitive devices; and calculate the optical path deviation in a z-axis according to the displacement of the calibrated image detected by the set of calibration photosensitive devices. ### Claim 15 (depends on 14) The compensation apparatus according to claim 14, wherein the image processor is further configured to: calculate the optical path deviation twisting around the y-axis according to the optical path deviation in the z-axis; and calculate the optical path deviation twisting around the z-axis according to the optical path deviation in the y-axis. ### Claim 16 (depends on 9) The compensation apparatus according to claim 9, wherein a magnitude and direction of the optical path deviation is calculated based on a displacement of the calibrated images in the direction of image processing. ### Claim 17 A method, comprising: obtaining a calibrated image by detecting a calibration board approximately located at one side of a platform of a scanner with a set of calibration photosensitive devices, the calibration board providing a pattern that varies along one or more optical paths; and calculating an optical path deviation based at least in part on the calibrated image to adjust the scanned image, said calculating comprising comparing the calibrated image to calculate said optical path deviation based at least in part on a variation in the pattern along one or more of the optical paths. ### Claim 18 (depends on 17) The method according to claim 17, further comprising: calculating the optical path deviation in an x-axis according to a displacement of the calibrated image detected by the set of calibration photosensitive devices; calculating the optical path deviation in a y-axis according to the displacement of the calibrated image detected by the set of calibration photosensitive devices; and calculating the optical path deviation in a z-axis according to the displacement of the calibrated image detected by the set of calibration photosensitive devices. ### Claim 19 (depends on 17) The method according to claim 17, further comprising: calculating the optical path deviation twisting around the y-axis according to the optical path deviation in the z-axis; and calculating the optical path deviation twisting around the z-axis according to the optical path deviation in the y-axis. ### Claim 20 (depends on 17) The method according to claim 17, wherein a magnitude and direction of the optical path deviation is calculated based on a displacement of the calibrated images along one or more of the optical paths. ### Claim 21 An apparatus, comprising: means for obtaining a calibrated image by detecting a calibration board approximately located at one side of a platform of a scanner with a set of calibration photosensitive devices,the calibration board providing a pattern that varies along one or more optical paths; and means for calculating an optical path deviation based at least in part on the calibrated image to adjust the scanned image, said means for calculating comprising means for comparing the calibrated image to calculate the optical path deviation based at least in part on a variation of the pattern along the one or more optical paths. ### Claim 22 (depends on 21) The apparatus according to claim 21, further comprising: means for calculating the optical path deviation in an x-axis according to a displacement of the calibrated image detected by the set of calibration photosensitive devices; means for calculating the optical path deviation in a y-axis according to the displacement of the calibrated image detected by the set of calibration photosensitive devices; and means for calculating the optical path deviation in a z-axis according to the displacement of the calibrated image detected by the set of calibration photosensitive devices. ### Claim 23 (depends on 22) The apparatus according to claim 22, further comprising: means for calculating the optical path deviation twisting around the y-axis according to the optical path deviation in the z-axis; and means for calculating the optical path deviation twisting around the z-axis according to the optical path deviation in the y-axis. ### Claim 24 (depends on 21) The apparatus according to claim 21, wherein a magnitude and direction of the optical path deviation is calculated based on a displacement of the calibrated images along the one or more optical paths.