# US 7,746,513 B2 · Scanner and method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,513 B2 - Document ID: US7746513B2 - Status: Granted - Kind: B2 - Application number: 11/098,304 - Filed: 2005-04-04 - Published: 2005-10-06 - Granted: 2010-06-29 - Earliest claimed: 2004-04-05 - Assignees: Avision Inc. - Inventors: Yen-Cheng Chen; Shing-Chia Chen - Web page: https://patentgrep.com/patent/US7746513B2 ## CPC - H04N 1/40056: {Circuits for driving or energising particular reading heads or original illumination means (H04N1/401, H04N1/407 take precedence)} - 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: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A scanner including a light source, an optical module, a driving device, and a control unit is provided. The light source emits a light beam to the to-be-scanned document. The optical module includes a photo sensing device for receiving the light beam reflected by the to-be-scanned document. The driving device includes a position detecting device, for detecting a position of the optical module relative to the to-be-scanned document, and outputting a position feedback signal accordingly. The control unit includes a light source controller and a timer. The scanning method includes the steps of setting the value of K to 1; moving the optical module to read the Kth scan line and adjusting the luminance of the light source to compensate exposure level of the (K+1)th scan line; and determining if K is smaller than N. ## Claims ### Claim 1 A scanner, comprising: a light source, for emitting a light beam to a to-be-scanned document; an optical module, comprising a photo sensing device for receiving the light beam reflected by the to-be-scanned document, for reading a plurality of scan lines of the to-be-scanned document; a driving device for generating a relative movement between the optical module and the to-be-scanned document, wherein the driving device comprises a position detecting device for detecting a position of the optical module relative to the to-be-scanned document and outputting a position feedback signal accordingly; and a control unit, comprising a light source controller for controlling the luminance of the light source, and a timer for controlling the light source controller according to the position feedback signal, so that exposure level for each of the scan lines remains the same. ### Claim 2 (depends on 1) The scanner according to claim 1, wherein the timer calculates exposure time for each scan line according to the position feedback signal, and controls the light source controller to adjust the luminance of the light source according to the exposure time, so that the exposure level for each of the scan lines remains the same. ### Claim 3 (depends on 1) The scanner according to claim 1, wherein the position detecting device comprises an encoder. ### Claim 4 (depends on 1) The scanner according to claim 1, wherein the photo sensing device is a charge coupled device (CCD). ### Claim 5 (depends on 1) The scanner according to claim 1, wherein the photo sensing device is a contact image sensor (CIS). ### Claim 6 (depends on 1) The scanner according to claim 1, wherein the to-be-scanned document is a reflective document. ### Claim 7 (depends on 1) The scanner according to claim 1, wherein the to-be-scanned document is a transmissive document. ### Claim 8 (depends on 1) The scanner according to claim 1, wherein the scanner is a flatbed scanner having a scan flatbed to carry the to-be-scanned document, and the driving device moves the optical module to generate the relative movement. ### Claim 9 (depends on 1) The scanner according to claim 1, wherein the scanner is a sheet-fed scanner having a document feeding device, and the driving device drives the document feeding device to move the to-be-scanned document to generate the relative movement. ### Claim 10 (depends on 1) The scanner according to claim 1, wherein the driving device is a direct current (DC) motor. ### Claim 11 (depends on 1) The scanner according to claim 1, wherein the driving device is a step motor. ### Claim 12 A scanning method for a scanner, for scanning a to-be-scanned document, the method comprising: emitting a light beam to the to-be-scanned document by a light source; receiving the light beam reflected by the to-be-scanned document by a photo sensing device of an optical module; reading the N scan lines of the to-be-scanned document where N is a natural number by the photo sensing device; generating a relative movement between the optical module and the to-be-scanned document and outputting a position feedback signal according to a position of the optical module relative to the to-be-scanned document by a driving device; setting a K value to 1; reading a Kth scan line of the to-be-scanned document by the photo sensing device; obtaining Kth exposure time for the Kth scan line by a timer; adjusting the luminance of the light source according to the Kth exposure time to compensate exposure level for a (K+1)th scan line by a light source controller; and increasing K by 1 if the value of K is smaller than N and returning to the step of reading the Kth scan line of the to-be-scanned document by the control unit. ### Claim 13 (depends on 12) The method according to claim 12, wherein the step of sensing the Kth scan line of the to-be-scanned document further comprises: moving the optical module to a Kth position and then outputting a Kth position feedback signal corresponding to the Kth position by the driving device; moving the optical module to a (K+1)th position and accordingly outputting a (K+1)th position feedback signal corresponding to the (K+1)th position by the driving device; and starting exposing the Kth scan line according to the Kth position feedback signal and stop exposing the Kth scan line according to the (K+1)th position feedback signal by the photo sensing device. ### Claim 14 (depends on 13) The method according to claim 13, wherein the Kth exposure time is determined according to the Kth position feedback signal and the (K+1)th position feedback signal. ### Claim 15 (depends on 12) The method according to claim 12, wherein the step of sensing the Kth scan line of the to-be-scanned document further comprises: moving the to-be-scanned document to a Kth position and then outputting a Kth position feedback signal corresponding to the Kth position by the driving device; moving the to-be-scanned document to a (K+1)th position and accordingly outputting a (K+1)th position feedback signal corresponding to the (K+1)th position by the driving device; and starting exposing the Kth scan line according to the Kth position feedback signal and stop exposing the Kth scan line according to the (K+1)th position feedback signal by the photo sensing device. ### Claim 16 (depends on 15) The method according to claim 15, wherein the Kth exposure time is determined according to the Kth position feedback signal and the (K+1)th position feedback signal.