Source: http://www.google.com/patents/US6728008?dq=6,460,050
Timestamp: 2014-04-16 13:51:16
Document Index: 281785118

Matched Legal Cases: ['art 18', 'art 18', 'art 18', 'art 18', 'art 18', 'art 18']

Patent US6728008 - Method for diagnosing optical devices installed in image reading apparatus ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsIn a method for diagnosing an optical device, the positions of intersections between a scanning line and the line segments of an adjustment mark provided in a predetermined position, and output levels at the intersections are detected on the basis of the output characteristic of an output level corresponding...http://www.google.com/patents/US6728008?utm_source=gb-gplus-sharePatent US6728008 - Method for diagnosing optical devices installed in image reading apparatus and image forming apparatusAdvanced Patent SearchPublication numberUS6728008 B1Publication typeGrantApplication numberUS 09/387,512Publication dateApr 27, 2004Filing dateSep 1, 1999Priority dateSep 4, 1998Fee statusLapsedAlso published asCN1122888C, CN1247334A, DE69919096D1, EP0985978A2, EP0985978A3, EP0985978B1Publication number09387512, 387512, US 6728008 B1, US 6728008B1, US-B1-6728008, US6728008 B1, US6728008B1InventorsYoshikatsu KamisuwaOriginal AssigneeKabushiki Kaisha Toshiba, Toshiba Tec Kabushiki KaishaExport CitationBiBTeX, EndNote, RefManPatent Citations (18), Non-Patent Citations (5), Referenced by (9), Classifications (20), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetMethod for diagnosing optical devices installed in image reading apparatus and image forming apparatusUS 6728008 B1Abstract In a method for diagnosing an optical device, the positions of intersections between a scanning line and the line segments of an adjustment mark provided in a predetermined position, and output levels at the intersections are detected on the basis of the output characteristic of an output level corresponding to each pixel position and obtained by reading the adjustment mark along the scanning line. The detected output levels are compared with a predetermined value to detect an error due to the attachment position of the optical device.
What is claimed is: 1. A method of diagnosing an optical device having a plurality of photoelectric elements that are arranged in a scanning line in a main scanning direction, for receiving light reflected from a document and outputting a signal corresponding to an amount of light received, comprising:
a first step of reading, along a predetermined scanning line, a figure that consists of a first straight line perpendicular to the main scanning direction, second and third straight lines parallel to each other and intersect the first straight line at an acute angle, using the photoelectric elements of the optical device opposed to the figure with a predetermined space interposed therebetween; a second step of detecting respective positions of first, second and third intersections between the scanning line and each of the first, second and third straight lines of the figure, and also detecting output levels of signals corresponding to the intersections, on the basis of signals output when the figure has been read along the scanning line; and a third step of comparing the detected positions of the intersections with positions of respective predetermined points which are to detect the intersections, and the detected output levels of the signals corresponding to the intersections with respective predetermined output levels of signals corresponding to respective predetermined points, thereby detecting an error due to an attachment position of the optical device. 2. A method according to claim 1, wherein the second straight line intersects an end of the first straight line, and the third straight line intersects the other end of the first straight line.
in the third step, a difference between a distance from the detected first intersection to the detected second intersection and a distance from the detected first intersection to the detected third intersection is compared with a predetermined minimum value, thereby detecting a displacement of the scanning line in a direction perpendicular to the main scanning direction. 7. A method according to claim 1, wherein an output level of at least one of the intersections detected in the second step is compared with a predetermined output level, thereby detecting a focus error of the scanning line.
a fourth step of comparing an output level of a signal corresponding to each of at least two of the intersections detected in the second step, with a predetermined output level, thereby detecting an error in focus of each of the at least two of the intersections; and a fifth step of detecting an inclination of the scanning line with respect to a light advancing direction on the basis of the error in focus of said each of the at least two of the intersections. 9. A method according to claim 1, wherein a distance between the second and third intersections detected in the second step is compared with a predetermined distance, thereby detecting an inclination of the scanning line with respect to the main scanning direction.
the optical device includes a plurality of line sensors having photoelectric elements that are arranged parallel to the main scanning direction and correspond to respective colors; in the first step, the scanning line includes a middle point of the first straight line, and the figure is read by each line sensor along the scanning line; in the second step, each line sensor detects respective positions of first, second and third intersections for a corresponding color between the scanning line and each of the first, second and third straight lines of the figure; and in the third step, a displacement of that one of the line sensors in the main scanning direction which corresponds to a first color is detected by comparing an output level of a signal corresponding to the first intersection for the first color, with a predetermined output level, and a displacement of that one of the line sensors in the main scanning direction which corresponds to a second color is detected by comparing an output level of a signal corresponding to the first intersection for the second color, with a predetermined output level, thereby detecting, on the basis of the displacements, an inclination of each scanning line with respect to a sub scanning direction perpendicular to the main scanning direction.
BACKGROUND OF THE INVENTION This invention relates to a method for diagnosing an optical device, and more particularly to a method for diagnosing both optical devices installed in a scanner section and a printer section that are incorporated in, for example, a digital copy machine.
BRIEF SUMMARY OF THE INVENTION The present invention has been developed to solve the aforementioned problems, and is aimed at providing a method of diagnosing an optical device and capable of always providing stable image quality at low cost and using a simple system.
DETAILED DESCRIPTION OF THE INVENTION Diagnosis methods for optical devices according to the embodiments of the invention will be described with reference to the accompanying drawings.
A second carriage CR2 is provided obliquely below the document table 11 in a direction in which the light reflected from the first mirror 15 is guided. The second carriage CR2 has a second mirror 20 for further bending the light reflected from the document D and bent by the first mirror 15, and a third mirror 21 located at right angles to the second mirror 20. The second carriage CR2 is driven by the first carriage CR1 through, for example, a driving toothed belt. The second carriage CR2 is moved along the document table 11 at a rate � of that of the first carriage CR1.
The line segment 212 a has one end intersecting one end of the line segment 212 b at an acute angle, and the other end intersecting one end of the line segment 212 c at an acute angle. Further, the angle (angle of inclination) formed between the line segments 212 a and 212 b and between the line segments 212 a and 212 c is set in accordance with the detection sensitivity, and set at, for example, 45� in the FIG. 5 case.
The adjustment mark 212 is formed such that when the scanner section 4 scans a scanning line in a direction parallel to the main scanning direction to pass the center of the line segment 212 a, the distance between the intersections of the scanning line and the line segments 212 a and 212 b is equal to that between the intersections of the scanning line and the line segments 212 a and 212 c. In other words, the distance between the intersections 213 a and 213 b is set equal to that between the intersections 213 a and 213 c. Actually, the chart 18 for exclusive use in diagnosis comprises four adjustment marks, i.e. a first mark 219, a second mark 220, a third mark 221 and a fourth mark 222, as is shown in FIG. 6. The first to fourth marks 219-222 are arranged such that an intersection C1 between the line segments 219 a and 219 b of the first mark 219, an intersection C2 between the line segments 220 a and 220 b of the second mark 220, an intersection C3 between the line segments 221 a and 221 b of the third mark 221, and an intersection C4 between the line segments 222 a and 222 b of the fourth mark 222 form the four corner points of a rectangle.
In the adjustment device 120, the positional relationship between the chart 18 with the adjustment mark 212 and the optical device OP is set such that the optical path extending between the chart and the optical device has the same length as that extending from the document surface of the document table 11 to the CCD line sensor 23 when the optical device OP is mounted in the scanner section 4. At this time, the chart 18 is located on the object surface of the image forming lens 22, and the main-scanning-directional scanning line perpendicularly intersects the line segment 212 a of the adjustment mark 212 such that the distance between the intersections 213 a and 213 b is equal to that between the intersections 213 a and 213 c. The chart 18 enables diagnosing of the following to-be-diagnosed items (hereinafter referred to as �diagnosis items�) in the former stage. Hereinafter suppose that the main scanning direction, the sub scanning direction, and the beam advancing direction are expressed by the X-axis, the Z-axis and the Y-axis, respectively, and that the directions of rotation about the X-, Z- and Y-axes are expressed by θx, θz and θy, respectively.
In the latter stage, the optical device OP that has the image forming lens 22 and the CCD line sensor 23 adjusted to positions on the basis of the errors detected in the former stage is fixed at a predetermined location in the scanner section 4, whereby an error in the positional relationship between the document surface and the optical device OP assumed via first, second and third mirrors 15, 20 and 21 is detected. Then, deviation of magnification from a set value, distortion of an image, and a positional error of the chart in the main scanning direction or the sub scanning direction on the document surface, which are caused by an error in the attachment position of the optical device OP, are adjusted. The image distortion indicates a distortion caused when the first and/or second carriages CR1, CR2 shifts in the sub scanning direction�a distortion as shown in FIG. 10, in which the angles of corresponding corners differ between an original rectangle 317 and a corresponding FIG. 318 obtained by reading the rectangle 317.
In the chart 18, the first to fourth marks each consist of three line segments. However, to detect distortion of an image and an error in magnification, the chart may include four marks, which form a rectangle and each consist of two line segments�a line segment perpendicular to the main scanning direction, and a line segment aligned with a diagonal of the rectangle. For example, the chart may include a first mark 219 consisting of line segments 219 a and 219 b, a second mark 220 consisting of line segments 220 a and 220 b, a third mark 221 consisting of line segments 221 a and 221 b, and a fourth mark 222 consisting of line segments 222 a and 222 b. In the latter stage, to adjust the scanner section 4, the chart 18 is placed on the document table 11. In this state, a predetermined scanning line on the first and second marks 219 and 220 and a predetermined scanning line on the third and fourth marks 221 and 222 are read.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS5361131Aug 12, 1992Nov 1, 1994Hamamatsu Photonics K.K.Optical displacement measuring apparatus utilizing Fourier transform methodUS5539519Aug 11, 1992Jul 23, 1996Copal Company LimitedCompact, high resolution optical displacement detectorUS5600574May 13, 1994Feb 4, 1997Minnesota Mining And Manufacturing CompanyAutomated image quality controlUS5631686Dec 17, 1993May 20, 1997Xerox CorporationMethod to provide optimum optical contrast for registration mark detectionUS5798826Mar 20, 1997Aug 25, 1998Olympus Optical Co., Ltd.Optical displacement sensorUS5847884Jul 9, 1997Dec 8, 1998Minolta Co., Ltd.Image reading apparatusUS6229629 *Sep 11, 1998May 8, 2001Mustek Systems Inc.Device and method for quick and precise determination of scan start point for image scannerUS6243173 *Jul 15, 1998Jun 5, 2001Samsung Electronics Co., Ltd.Method and apparatus for correcting alignment error of scanning head of a shuttle type scannerUS6381043 *Mar 24, 1999Apr 30, 2002Mustek Systems Inc.Device used in image scanner for quickly and precisely determining scan start point and improving scanning qualityUS6411405 *Dec 8, 1998Jun 25, 2002Samsung Electronics, Co., Ltd.Method and apparatus for correcting scanning errors in a shuttle type scannerUS6498339 *Jun 20, 2000Dec 24, 2002Toshiba Tec Kabushiki KaishaDisplacement diagnosing method applied to an image read-out apparatusJP2659189A Title not availableJP36319603A * Title not availableJP40507249A * Title not availableJPH05188744A Title not availableJPH09101642A Title not availableJPH09218470A Title not availableJPH09298635A Title not available* Cited by examinerNon-Patent CitationsReference1 *Chen et al., "Scanner with Reference Pattern for Merging Images and Method of Merging Images," US patent application Publication No. US2002/0105683 A1, Aug. 8, 2002.*2Patent Abstracts of Japan, vol. 017, No. 399 (P-1579), Jul. 26, 1993, Japanese Patent 05-072492 A, published Mar. 26, 1993.3Patent Abstracts of Japan, vol. 017, No. 404 (E-1405), Jul. 28, 1993, Japanese Patent 05-075797 A, published Mar. 26, 1993.4Patent Abstracts of Japan, vol. 1996, No. 08, Aug. 30, 1996, Japanese Patent 08-102818 A, published Apr. 16, 1996.5 *Shih et al, "Image Scanning Apparatus Capable of Positioning a Scan-Starting Point." US patent application Publication No. 2002/0159097 A1, Oct. 31, 2002.** Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS7001830 *Sep 2, 2003Feb 21, 2006Advanced Micro Devices, IncSystem and method of pattern recognition and metrology structure for an X-initiative layout designUS7116845 *Jan 18, 2002Oct 3, 2006Avision Inc.Scanner with a reference pattern for merging images and method of merging imagesUS7136204 *Oct 8, 2002Nov 14, 2006Chin-Lin ChangFull-zone optical image addressing apparatusUS7391532 *Jan 30, 2001Jun 24, 2008Canon Kabushiki KaishaImage correction in image sensing system including image sensing apparatus and image processing apparatusUS7483591 *Feb 17, 2004Jan 27, 2009Xerox CorporationImage transfer apparatus with streak removal systemUS7492692 *Dec 17, 2004Feb 17, 2009Pioneer CorporationHologram recording and reproducing apparatusUS7672209Jul 7, 2005Mar 2, 2010Pioneer CorporationHologram recording/reproducing apparatus, hologram reproducing apparatus and method, and computer programUS8064108Aug 18, 2006Nov 22, 2011Transpacific Systems, LlcFull-zone optical image addressing apparatus and methodUS8072866Mar 3, 2006Dec 6, 2011Pioneer CorporationMarker selection method for hologram recording device* Cited by examinerClassifications U.S. Classification358/474, 358/497, 358/406International ClassificationH04N1/00Cooperative ClassificationH04N1/00063, H04N1/00408, H04N1/00029, H04N1/00053, H04N1/00045, H04N1/00002, H04N1/00082, H04N1/00013European ClassificationH04N1/00A3T, H04N1/00A3M, H04N1/00A4C, H04N1/00A2C, H04N1/00A3J, H04N1/00D3D, H04N1/00A3B, H04N1/00ALegal EventsDateCodeEventDescriptionJun 17, 2008FPExpired due to failure to pay maintenance feeEffective date: 20080427Apr 27, 2008LAPSLapse for failure to pay maintenance feesNov 5, 2007REMIMaintenance fee reminder mailedSep 1, 1999ASAssignmentOwner name: KABUSHIKI KAISHA TOSHIBA, JAPANOwner name: TOSHIBA TEC KABUSHIKI KAISHA, JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KAMISUWA, YOSHIKATSU;REEL/FRAME:010222/0919Effective date: 19990826RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google