WO2004105378A1 - 画像位置補正方法、画像位置補正用治具、及び、画像形成装置 - Google Patents
画像位置補正方法、画像位置補正用治具、及び、画像形成装置 Download PDFInfo
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- WO2004105378A1 WO2004105378A1 PCT/JP2004/006741 JP2004006741W WO2004105378A1 WO 2004105378 A1 WO2004105378 A1 WO 2004105378A1 JP 2004006741 W JP2004006741 W JP 2004006741W WO 2004105378 A1 WO2004105378 A1 WO 2004105378A1
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- image forming
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
- H04N1/00007—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for relating to particular apparatus or devices
- H04N1/00013—Reading apparatus
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
- H04N1/00007—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for relating to particular apparatus or devices
- H04N1/00015—Reproducing apparatus
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
- H04N1/00026—Methods therefor
- H04N1/00031—Testing, i.e. determining the result of a trial
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
- H04N1/00026—Methods therefor
- H04N1/00045—Methods therefor using a reference pattern designed for the purpose, e.g. a test chart
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
- H04N1/00026—Methods therefor
- H04N1/00058—Methods therefor using a separate apparatus
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
- H04N1/00026—Methods therefor
- H04N1/00063—Methods therefor using at least a part of the apparatus itself, e.g. self-testing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
- H04N1/00071—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for characterised by the action taken
- H04N1/00082—Adjusting or controlling
- H04N1/00087—Setting or calibrating
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/00002—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for
- H04N1/00071—Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for characterised by the action taken
- H04N1/0009—Storage
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
- H04N1/10—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using flat picture-bearing surfaces
- H04N1/1013—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using flat picture-bearing surfaces with sub-scanning by translatory movement of at least a part of the main-scanning components
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
- H04N1/12—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using the sheet-feed movement or the medium-advance or the drum-rotation movement as the slow scanning component, e.g. arrangements for the main-scanning
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
- H04N1/19—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using multi-element arrays
- H04N1/191—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using multi-element arrays the array comprising a one-dimensional array, or a combination of one-dimensional arrays, or a substantially one-dimensional array, e.g. an array of staggered elements
- H04N1/192—Simultaneously or substantially simultaneously scanning picture elements on one main scanning line
- H04N1/193—Simultaneously or substantially simultaneously scanning picture elements on one main scanning line using electrically scanned linear arrays, e.g. linear CCD arrays
Definitions
- Image position correcting method image position correcting jig, and image forming apparatus
- the present invention relates to an image position correction method for correcting errors in image position and image magnification in an image forming apparatus, an image position correction jig used in the method, and an image to which the method is applied.
- the present invention relates to a forming apparatus.
- the image position of the output image with respect to the reference image which is the read document is the read document.
- the error in the image magnification is the difference between the error in the image reading position and the image reading magnification that occurs when the image reading unit reads an image, and the error in the image forming position and the image forming magnification that occurs when the image forming unit forms an image.
- the error in the image forming section of the image forming apparatus and the error in the image reading section of the image forming apparatus are superimposed to form an error in the overall image position and image magnification.
- an image reading unit reads a predetermined reference image, calculates an image reading magnification correction value, and then forms an image of the reference image in the image forming unit.
- an image in which an output image is created is read by an image reading unit to calculate a correction value of an image forming magnification (for example, see Patent Document 2).
- This image forming apparatus individually calculates an error of the image forming section and an error of the image reading section in the image forming apparatus.
- the optical system of the image reading unit scans the image by scanning the optical system of the image reading unit in opposition to the document table on which the original is placed.
- an image forming apparatus which can selectively perform an original reading method of reading an image by arranging the original at a position opposed to the original with a platen interposed therebetween.
- it is necessary to separately correct an error that occurs in the image reading unit when reading an image in the original fixed system and an error that occurs in the image reading unit when reading an image in the original moving system. Therefore, in an image forming apparatus that selectively executes the fixed-document-type image reading process and the original-movement-type image reading process, the complicated operation of correcting the image position and the image magnification becomes an even more serious problem. .
- An object of the present invention is to perform an image reading process and an image forming process only once, and to correct the error in the image reading position and the image reading magnification in the image reading unit and the error in the image forming unit.
- An image position correction method and an image position correction jig that can individually and independently correct the image formation position and the image formation magnification error, and can easily and quickly perform accurate image position and image magnification correction operations.
- An object and an image forming apparatus are provided.
- Another object of the present invention is to perform the image reading process of the original fixed system only by performing the image reading process of the original fixed system, the image reading process of the original moving system, and the image forming process each time. And an error in the image reading position and the image reading magnification in the image reading unit and an error in the image forming position and the image forming magnification in the image forming unit in each of the image reading processes of the original moving method. It is an object of the present invention to provide an image position correcting method and an image forming apparatus capable of performing accurate and accurate image position and image magnification correction work easily and quickly.
- Patent Document 1 JP-A-10-186994
- Patent Document 2 Japanese Patent Application Laid-Open No. 08-265560
- the present invention may have the following configuration as means for solving the above-mentioned problems.
- a reference image forming step of forming a first reference image including an image used for measuring an error of an image forming position and an error of an image forming magnification on a sheet and an image reading unit
- the image of a sheet placed at an appropriate position on the platen after the formation of the first reference image is converted into an image used for measuring an error in image reading position and an error in image reading magnification.
- the control unit determines the image forming position in the image forming unit based on the measured error in the image reading position and the error in the image reading magnification and the first reference image in the correction image.
- the image used for measuring the error of the image reading position and the error of the image reading magnification in the 1S image reading unit is read as a correction image together with a second reference image arranged at an appropriate position on the platen, After the error in the image reading unit is measured based on the second reference image in the correction image, the error in the image forming unit is determined based on the error in the image reading unit and the first reference image in the correction image. Measured. Therefore, by performing only one image forming operation and one image reading operation, both the error in the image forming unit and the error in the image reading unit are measured. This makes it possible to easily and quickly correct the image position and correct the image magnification.
- a reference image information input step of storing image information of the first reference image input from an external device in an internal memory is included.
- the image information relating to the first reference image formed on the paper in the image forming unit for measuring the error of the image forming position and the error of the image forming magnification is supplied from an external device. Is done. Therefore, it is not necessary to store information for the image position correcting operation in the image forming apparatus in advance. Thus, a uniform image position correction operation can be performed on a large number of image forming apparatuses at the time of factory shipment or the like.
- a reference image information reading step of reading image information related to the first reference image from an internal nonvolatile memory before the reference image forming step is included.
- the image information related to the first reference image formed on the sheet in the image forming unit for measuring the error of the image forming position and the error of the image forming magnification is stored in the image forming apparatus. From the non-volatile memory. Therefore, there is no need to receive supply of image information from an external device before starting the image position correction work. As a result, the image position correcting operation can be performed at an arbitrary timing such as at the time of maintenance after installation at the user position.
- a reference image information reading step of storing image information of the first reference image read from an external recording medium in an internal memory is included. It is characterized by.
- the image information related to the first reference image formed on the paper in the image forming unit for measuring the error of the image forming position and the error of the image forming magnification is stored in an external recording medium. Read from. Therefore, there is no need to store information for the image position correction operation in the image forming apparatus in advance, and it is not necessary to receive supply of image information from an external device prior to the start of the image position correction operation. This makes it possible to cope with the execution of the image position correction work at an arbitrary timing.
- the method includes a document placing step of placing the document at a predetermined position on a document table together with the formed image correcting jig.
- the sheet on which the first reference image is formed is placed at a predetermined position on the document table via the image correction jig on which the second reference image is formed on the bottom surface.
- the operation of reading the correction image is performed. Therefore, the first reference image and the second reference image constituting the correction image are read from the paper placed at a predetermined position on the document table and the image correction jig.
- the image position correction operation can be accurately performed using the correction image.
- the reference image forming step includes a first reference including an image indicating a center position in the main scanning direction, an image having a predetermined length in the main scanning direction, and an image having a predetermined length in the sub-scanning direction. Forming an image,
- the correction image reading step includes a second image including an image indicating the center position in the main scanning direction, an image having a predetermined length in the main scanning direction, and an image having a predetermined length in the sub scanning direction, together with the image of the sheet.
- a step of reading the reference image includes a second image including an image indicating the center position in the main scanning direction, an image having a predetermined length in the main scanning direction, and an image having a predetermined length in the sub scanning direction, together with the image of the sheet.
- the correction image includes an image indicating the center position in the main running direction, an image having a predetermined length in the main running direction, and an image having a predetermined length in the sub running direction.
- the main running direction and the sub running direction in the image reading section are obtained.
- Information to be used can be read from the first reference image and the second reference image arranged at predetermined positions on the document table.
- the image reading unit error measuring step includes the step of reading the image information of the first reference image in which the second reference image read by the image reading unit in the correction image reading step is stored in an internal memory. It is characterized in that it is a step of comparing with a report.
- the error of the image reading unit is measured by comparing the second reference image read by the image reading unit with the image information of the first reference image. Accordingly, the predetermined length of the image included in the second reference image in the main running direction, the predetermined length, and the predetermined length in the sub-scanning direction are included in the first reference image. If a predetermined length in the main scanning direction and a predetermined length in the sub-scanning direction of the included image are matched, the error of the image reading magnification in the image reading unit can be measured from the comparison result. .
- the image forming unit error measuring step includes the steps of: storing the first reference image read by the image reading unit in the correction image reading step in an internal memory; And removing the error of the image forming section measured in the image reading section error measuring step from the result of comparison with the information.
- the error of the image reading unit is measured by excluding the error of the image forming unit from the result of comparing the first reference image read by the image reading unit with the image information of the first reference image. You.
- the image forming unit uses the first reference image read in a state where the error in the image forming operation in the image forming unit and the error in the image reading operation in the image reading unit overlap each other. An error in the formation position and an error in the image formation magnification can be measured.
- correction information for correcting the image information read by the image reading unit based on the error in the image reading position and the error in the image reading magnification is created.
- An image reading section correction information creating step of storing the image forming section error information in an internal memory at least after the image forming section error measuring step.
- the corrected information of the image forming unit is stored in an internal memory.
- the image information is corrected using the correction information stored in the internal memory so that the measurement of the error and the generation of the correction information are not repeated. can do.
- the image reading section correction information creating step includes: image reading start position information when reading the image information read by the image reading section from the image memory; and image reading magnification information when scaling the image information in the image memory. Is a step of creating
- the image reading magnification information at the time of scanning is created and stored in the internal memory.
- the image information read during the normal image reading operation can be stored in the image memory in a state of being scaled by the image reading magnification information, and can be read from the image memory according to the image reading start position information. it can.
- the image forming unit correction information creating step includes: an image forming start position information when the image information is written in the image forming unit; an image forming magnification information when the image information is scaled in the image memory; And a step of creating sheet conveyance speed information when a sheet is conveyed in the image forming section.
- the image forming start position information when writing the image information to the image forming unit and the image information are scaled in the image memory.
- the image forming magnification information at that time and the paper transport speed information when transporting the paper in the image forming section are created and stored in an internal memory.
- the image information supplied to the image forming section during the normal image forming operation is enlarged or reduced by the image forming magnification information, and is stored in the image memory according to the image forming start position information.
- the sheet is conveyed in the image forming unit in accordance with the sheet conveyance speed information while being read.
- the image of the paper placed at an appropriate position on the first platen after the formation of the first reference image is compared with the image reading position error and the image reading magnification error.
- a control unit configured to determine an error in an image forming position in the image forming unit based on an error in an image reading position and an error in an image reading magnification in the fixed image reading unit and a first reference image in the first correction image;
- a control unit configured to execute the image reading position error and the image reading position error in the moving image reading unit based on the image forming position error and the image forming magnification error in the image forming unit and the first reference image in the second correction image.
- a moving image reading unit error measuring step for measuring an error in the image reading magnification;
- the first reference image including the image used for measuring the error of the image forming position and the error of the image forming magnification formed on the sheet in the image forming unit is read by the fixed image reading unit.
- the image used for measuring the position error and the image reading magnification error is read as the first correction image together with the second reference image arranged at an appropriate position on the first platen, and the moving image forming unit Read as a second correction image Be taken away.
- An error in the fixed image reading unit is measured based on the second reference image in the first correction image, and based on the error in the fixed image reading unit and the first reference image in the first correction image.
- the error in the image forming unit is measured, and the error in the moving image reading unit is measured based on the error in the image forming unit and the first reference image in the second correction image. Therefore, by performing only one image forming operation, a fixed document image reading process, and a document moving image reading process, errors in the image forming unit, errors in the fixed image reading unit, and errors in the moving image forming unit. All of the errors are measured.
- the reference image forming step is a step of forming a first reference image for the front surface and a first reference image for the back surface on each of the front and back surfaces of the sheet,
- the first correction image reading step is a step of reading at least one of the front and back images of the paper placed at an appropriate position on the first platen together with a second reference image as a first correction image.
- the front and rear images of the sheet conveyed with the front and back reversed via the second platen are converted to the front second correction image and the back surface second image. 2 This is the step of reading as a correction image
- the moving image reading unit error measuring step includes: an image forming position error and an image forming magnification error in the image forming unit; and a front first reference image and a back second correction in the front second correction image. Measuring the error of the image reading position and the error of the image reading magnification in reading the front image and the back image in the moving image reading unit based on the first reference image for the back side in the image for use. I do.
- the first reference image for the front surface and the first reference image for the back surface formed on each of the front and back surfaces of the sheet in the image forming unit are used for the second correction image for the front surface and the second reference image in the moving image forming unit.
- the image is read as the second correction image for the back surface.
- the front surface of the moving image reading unit is based on the error in the image forming unit and the first reference image for the front surface in the second correction image for the front surface and the first reference image for the back surface in the second correction image for the back surface.
- the errors during image reading and backside image reading are measured. Therefore, it is only necessary to perform the image forming operation once, the image reading process of the original fixed system, and the image reading process of the original moving system, respectively. Table in All errors in reading the surface image and errors in reading the back image in the moving image forming unit are measured.
- the image forming unit error measuring step the first reference image information read by the fixed image reading unit in the first correction image reading step is stored in an internal memory. From the result of the comparison with the fixed image reading unit, the error of the fixed image reading unit measured in the fixed image reading unit error measuring step,
- the moving image reading unit error measuring step is based on a result of comparing the first reference image read by the moving image reading unit in the second correction image reading step with first reference image information stored in an internal memory, This is a step of removing an error of the image forming section measured in the image forming section error measuring step.
- the comparison result between the first reference image in the first correction image read by the fixed image reading unit and the first reference image information in the memory excludes the error of the fixed image reading unit. After that, it is removed from the comparison result between the first reference image in the second correction image read by the moving image reading unit and the first reference image information in the memory. Therefore, the error occurring in the first reference image read while the sheet on which the first reference image is formed by the image forming unit while being transported through the second platen is determined by the fixed image reading unit and the image forming unit. The effect of the error caused by the error is removed, and the error caused only by the moving image reading unit is measured.
- the image information read by the moving image reading unit is corrected based on the error of the image reading position and the error of the image reading magnification in the moving image reading unit.
- the correction information of the moving image reading unit created based on the error of the image reading position and the error of the image reading magnification in the moving image reading unit is stored in the internal memory. Therefore, at the time of normal image reading work, the read image information is corrected accurately using the correction information stored in the internal memory without having to repeat the measurement of the error and the generation of the correction information.
- the moving image reading unit correction information creating step includes: transport start timing information for determining a transport start timing of the document to the second platen;
- the step is a step of creating transport speed information for determining the transport speed of the original to be copied.
- transport start timing information for determining a timing to start transporting the document to the second platen, and a transport speed of the document to the second platen Is determined. Therefore, an error generated in the moving image reading unit due to a change in the control content related to the document conveying operation of the moving image reading unit is corrected.
- the image forming apparatus is placed on a platen together with the paper on which the first reference image including the image used for measuring the image forming position error and the image forming magnification error is formed.
- a width equal to the width of the at least one image included in the first reference image in the sub scanning direction and shorter than the length of the document table of the image forming apparatus in the main scanning direction;
- the reference position on the platen of the image forming apparatus is indicated, and on the bottom surface, the second reference image used for measuring the error of the image reading position and the error of the image reading magnification when correcting the image position in the image forming apparatus.
- a pressing member for pressing the original to the upper surface of the original platen is provided.
- the sheet on which the first reference image is formed is placed at a predetermined position on the document table via the image correction jig on which the second reference image is formed on the bottom surface.
- the operation of reading the correction image is performed. Therefore, the first reference image and the second reference image constituting the correction image are read from the paper placed at a predetermined position on the document table and the image correction jig. This makes it possible to accurately perform the image position correction operation using the correction image.
- An image reading unit that reads image information of a document placed on a platen, an image forming unit that forms an output image based on the image information on paper, and an image reading unit and an image forming unit.
- a control unit for controlling the operation, and an image forming apparatus comprising:
- the image forming section forms an image on a sheet based on image information of a first reference image including an image used for measuring an image forming position error and an image forming magnification error during an image position correcting operation
- the image reading unit at the time of the image position correction operation, reads an image of a sheet placed at an appropriate position on the platen after an image based on the image information of the first reference image is formed, and reads the image at the image reading position.
- the image used for measuring the error of the image reading magnification and the error of the image reading magnification is read as a correction image together with the second reference image arranged at an appropriate position on the platen,
- the image reading section error measurement processing for measuring an image reading position error and an image reading magnification error in the image reading section based on a second reference image in the correction image during an image position correcting operation. Measuring the error of the image forming position and the error of the image forming magnification in the image forming unit based on the measured error of the image reading position and the error of the image reading magnification and the first reference image in the image for correction. Image forming unit error Based on the measurement processing, image reading position error, and image reading magnification error, image reading unit correction information for correcting the image information read by the image reading unit is created and stored in the internal memory.
- Image forming section correction information creating processing for creating image forming section correction information for correcting image information to be supplied to the image forming section based on an error in the image forming position and an error in the image forming magnification. It is characterized by executing an image forming section correction information creating process which is generated and stored in an internal memory.
- the image used for measuring the error in the image reading position and the error in the image reading magnification in the image reading unit is read as a correction image together with the second reference image arranged at an appropriate position on the platen, and is used for correction.
- the error in the image reading unit is measured based on the second reference image in the image
- the error in the image forming unit is measured based on the error in the image reading unit and the first reference image in the correction image. You. Therefore, by performing only one image forming operation and one image reading operation, both the error in the image forming unit and the error in the image reading unit are measured.
- the corrected information of the image forming unit is stored in an internal memory. Therefore, At the time of a normal image reading operation and a normal image forming operation, the image information is corrected by the correction information stored in the internal memory so that the measurement of the error and the generation of the correction information are not repeatedly performed.
- control unit may output the image information read by the image reading unit.
- the image position and the image magnification are corrected by the image reading unit correction information stored in the internal memory.
- the image information read by the image reading unit in the normal image reading operation is corrected with the image position and the image magnification corrected by the image reading unit correction information stored in the internal memory. Output to external device. Therefore, when the image forming apparatus is used as a scanner, the image information is supplied to an external device such as a printer in a state where an error generated during an image reading operation is corrected.
- control unit When the control unit forms an image on a sheet by the image forming unit based on the image information input from the external device other than at the time of the image position correction operation, the control unit receives the input from the external device.
- the image position and the image magnification of the image information are corrected by the image forming unit correction information stored in the internal memory.
- the image information input from the external device is supplied to the image forming unit after being corrected by the image forming unit correction information stored in the internal memory. Is done. Therefore, when the image forming apparatus is used as a printer, the image information is supplied to the image forming section in a state in which an error generated during the image forming operation is corrected in advance.
- the control unit is configured to perform image reading when the image forming unit forms an image on a sheet based on image information read by the image reading unit in an image reading operation other than the image position correcting operation.
- the image position and the image magnification of the image information read by the unit are corrected by the image reading unit correction information and the image forming unit correction information stored in the internal memory.
- the image information read by the image reading unit in the normal image reading operation is changed in image position and position by the image reading unit correction information stored in the internal memory.
- the image data is supplied to the image forming unit during normal image forming work in a state corrected by the image forming unit correction information stored in the internal memory. Therefore, when the image forming apparatus is used as a copying machine, the image information is supplied to the image forming section in a state where the error generated during the image reading operation and the error generated during the image forming operation are corrected.
- a fixed image reading unit that reads image information of a document placed on the first platen, a moving image reading unit that reads image information of a document conveyed via the second platen, and an image.
- An image forming unit that forms an output image based on the information on a sheet, and a control unit that controls operations of the fixed image reading unit, the moving image reading unit, and the image forming unit.
- the image forming unit forms an image on a sheet based on image information of a first reference image including an image used for measuring an error in an image forming position and an error in an image forming magnification during an image position correcting operation,
- the fixed image reading unit reads an image of a sheet placed at an appropriate position on the first platen after an image based on the image information of the first reference image is formed.
- An image used for measuring the reading position error and the image reading magnification error is read as a first correction image together with a second reference image arranged at an appropriate position on the first platen,
- the moving image reading unit during an image position correction operation, converts an image of a sheet conveyed via the second platen after an image based on the image information of the first reference image is formed into a second correction image.
- the control unit is configured to measure an error in an image reading position and an error in an image reading magnification in the fixed image reading unit based on a second reference image in the first correction image during an image position correction operation.
- An error measuring process based on a measurement result of an error of an image reading position and an error of an image reading magnification in the fixed image reading unit and an image forming position in the image forming unit based on a first reference image in the first correction image.
- Image forming unit error measurement processing for measuring the error of the image forming magnification and the error of the image forming position, the measurement result of the error of the image forming position and the error of the image forming magnification in the image forming unit, and the first reference in the second correction image.
- the first reference image including the image forming position error and the image forming magnification error image formed on the sheet in the image forming unit is read by the fixed image reading unit.
- the image used for measuring the position error and the image reading magnification error is read as the first correction image together with the second reference image arranged at an appropriate position on the first platen, and the moving image forming unit Read as the second correction image.
- An error in the fixed image reading unit is measured based on the second reference image in the first correction image, and based on the error in the fixed image reading unit and the first reference image in the first correction image.
- the error in the image forming unit is measured, and the error in the moving image reading unit is measured based on the error in the image forming unit and the first reference image in the second correction image. Therefore, by performing only one image forming operation, a fixed document image reading process, and a document moving image reading process, errors in the image forming unit, errors in the fixed image reading unit, and errors in the moving image forming unit. All of the errors are measured.
- correction information of the moving image reading unit created based on the error of the image reading position and the error of the image reading magnification in the moving image reading unit is stored in an internal memory. Therefore, at the time of a normal image reading operation, the read image information is corrected accurately using the correction information stored in the internal memory without having to repeat the measurement of the error and the generation of the correction information.
- the moving image reading unit includes a double-sided image reading function of sequentially transporting each of the front and back surfaces of the document via the second platen,
- the reference image forming process is a process of forming a first reference image for the front surface and a first reference image for the back surface on each of the front and back surfaces of the sheet,
- the first correction image reading process is a process of reading at least one of the front and back images of the paper placed at an appropriate position on the first platen together with a second reference image as a first correction image.
- the front and rear images of the sheet conveyed with the front and back reversed via the second platen are converted to the front second correction image and the back surface second image. 2 It is a process of reading as a correction image,
- the moving image reading unit error measuring process includes an image forming position error and an image forming magnification error in the image forming unit, and a front first reference image and a back second correction in the front second correction image.
- the first reference image for the front surface and the first reference image for the back surface formed on each of the front and back surfaces of the sheet in the image forming unit are used for the second correction image for the front surface and the second reference image in the moving image forming unit.
- the image is read as the second correction image for the back surface.
- the front surface of the moving image reading unit is based on the error in the image forming unit and the first reference image for the front surface in the second correction image for the front surface and the first reference image for the back surface in the second correction image for the back surface.
- the errors during image reading and backside image reading are measured. Therefore, it is only necessary to perform the image forming operation once, the image reading process of the original fixed system, and the image reading process of the original moving system, respectively. All of the errors at the time of reading the front surface image and the errors at the time of reading the back surface image in the moving image forming unit are measured.
- FIG. 1 is a diagram showing a configuration of an image forming apparatus to which an image position correcting method according to an embodiment of the present invention is applied.
- FIG. 2 is a plan view, a bottom view, and a side view of a use state of the correction jig of the present invention used during an image position correction operation in the image forming apparatus.
- FIG. 3 is a view showing a first reference image used for an image position correcting operation in the image forming apparatus.
- FIG. 4 is a plan view showing a state in which a sheet, which is a single-sided reference document, is fixed on a platen during an image position correction operation in the image forming apparatus.
- FIG. 5 is a diagram showing a first correction image read from a first platen during an image position correction operation in the image forming apparatus.
- FIG. 6 is a diagram showing measurement positions of main parts in the correction image.
- FIG. 7 is a block diagram including a control unit of the image forming apparatus.
- FIG. 8 is a flowchart showing an example of a processing procedure at the time of an image position correction operation in the image forming apparatus.
- FIG. 9 is a flowchart showing another example of a processing procedure at the time of an image position correction operation in the image forming apparatus.
- FIG. 10 is a view showing an example of an exposure unit provided in the image forming apparatus.
- FIG. 11 is a bottom view of a correction jig according to another embodiment of the present invention, which is used during an image position correction operation in the image forming apparatus.
- FIG. 12 is a diagram showing a configuration of an ADF used in the image forming apparatus.
- FIG. 13 is a flowchart illustrating an operation of the ADF at the time of a moving image reading process for a one-sided document.
- FIG. 14 is a flowchart illustrating an operation of the ADF during a moving image reading process for a two-sided document.
- FIG. 15 is a diagram showing a second correction image read from a second platen during an image position correction operation in the image forming apparatus.
- FIG. 16 is a plan view showing a state in which paper serving as a reference document for both sides is fixed on a document table during an image position correcting operation in the image forming apparatus.
- FIG. 1 is a diagram showing a configuration of an image forming apparatus to which an image position correcting method according to an embodiment of the present invention is applied.
- the image forming apparatus 100 is roughly divided into an upper image reading section 200 and a lower image forming section 300.
- the image reading unit 200 includes a first platen 210 made of a transparent glass body.
- An automatic document feeder (hereinafter, referred to as ADF) 220 is mounted above the document tables 210 and 211.
- the document tables 210 and 211 are covered by the ADF 220 so that the upper surface can be freely opened and closed.
- ADF automatic document feeder
- the ADF 220 selectively executes processing in the single-sided reading mode or processing in the double-sided reading mode.
- the ADF 220 guides a single or a plurality of documents placed on the document tray 221 one by one to the paper output tray 222 via the document table 211 at the time of processing in the one-sided reading mode.
- the ADF 220 guides a single or a plurality of documents placed on the document tray 221 at the time of processing in the duplex scanning mode to the intermediate tray 223 via the document table 211 in a profiled manner. By reversing, the document whose front and back surfaces are reversed is guided again to the discharge tray 222 via the document table 211.
- a first mirror base 231, a second mirror base 232, a lens 233, and a photoelectric conversion element (hereinafter, referred to as a CCD) 234 are provided below the document tables 210 and 211.
- the first mirror base 231 has a lamp unit 235 and a first mirror 236 mounted thereon, and is reciprocally movable in a horizontal direction below the document tables 210 and 211.
- the second mirror base 232 has a second mirror 237 and a third mirror 238 mounted thereon, and is reciprocally movable in a horizontal direction below the document tables 210 and 211.
- the mirrors 236-238 distribute the reflected light of the light of the lamp unit 235 on the document image surface to the lens 233.
- the lens 233 causes the reflected light distributed via the mirrors 236 to 238 to form an image on the light receiving surface of the CCD 234.
- the CCD 234 outputs an electric signal according to the amount of light received on the light receiving surface.
- the first document table 210, the first mirror base 231, the second mirror base 232, the lens 233, and the CCD 234 constitute a fixed image reading unit.
- the first mirror base 231 faces the second document table 211. Move to the position you want.
- the second mirror base 232 is used for reading an image of a document passing through the upper surface of the second document table 211 when the optical path length reaching the light receiving surface of the CCD 234 via the mirror 236 238 and the lens 233 is fixed. Move to a position that is equal to the optical path length.
- the reflected light of the light of the lamp unit 231 on the document image surface does not change the optical path length over the entire image surface of the document passing on the second document table 211, and the mirror 236 238 and the lens
- the light is received by the CCD 234 via the 233. Therefore, the image reading process of the original moving system is performed using the ADF 220, the second original plate 211, the first mirror source 231, the second mirror base 232, the lens 233, and the CCD 234.
- the ADF 220 and the second platen 211 constitute a moving image reading unit.
- the image forming unit 300 includes a charger 312, a developing unit 314, a transfer unit 315, a cleaner 316, and the like around the photosensitive drum 311 rotatably supported in the direction of arrow C, in the rotating direction of the photosensitive drum 311. Along with this order. Further, an exposure unit 313 for exposing the surface of the photoconductor drum 311 with image light is provided between the photoconductor drum 311 and the developing device 314 on the downstream side of the charger 312 in the rotation direction.
- the electric signal output from the CCD 234 of the image reading unit 200 is converted into digital data, subjected to predetermined image processing, and supplied to the exposure unit 313 as image data. Further, the image data input from the external device to the image forming apparatus 100 is developed into bitmap data, subjected to predetermined image processing, and supplied to the exposure unit 313 as image data.
- a paper feed cassette 321 is detachably mounted at the bottom of the image forming unit 300.
- the paper feed cassette 321 stores a predetermined number of sheets.
- the sheets stored in the sheet feeding cassette 321 are fed one by one by rotating the sheet feeding roller 322.
- Image forming unit 300 A paper transport path 323 is formed between the paper feed cassette 321 and the paper discharge tray 327 via the space between the photosensitive drum 311 and the transfer device 315.
- a fixing device 317 is arranged together with a plurality of rollers including a resist roller 329, a paper feed roller 322, and a paper discharge roller 328.
- the image forming section 300 is formed with a reversing conveyance path 324 that connects the downstream side of the fixing device 317 in the sheet conveyance path 323 between the sheet feeding roller 322 and the registration roller 329.
- an electrophotographic image forming process including the following charging step, exposure step, developing step, transfer step and fixing step is performed based on the image data. That is, after a single-polarity charge is uniformly applied to the surface of the photosensitive drum 311 rotating in the direction of arrow C by the charger 312 (charging step), the charge is modulated by image data from the exposure unit 313. The image light is exposed (exposure step). As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 311. The electrostatic latent image on the surface of the photosensitive drum 311 is visualized into a toner image by the toner supplied from the developing device 314 (developing step).
- the paper fed from the paper feed cassette 321 has the front end thereof opposed to the front end of the toner image formed on the surface of the photosensitive drum 311, and the registration roller 329 makes the transfer between the photosensitive drum 311 and the transfer device. Guided between 315 and.
- the toner image on the surface of the photoconductor drum 311 is transferred onto a sheet by a transfer unit 315 (transfer step), and is heated and pressed by a fixing device 317 to be firmly fixed on the sheet (fixing step).
- the surface of the photosensitive drum 311 is repeatedly used in the above-described image forming process after the residual toner including the paper dust is removed by the cleaner 316.
- FIG. 12 is a diagram showing a configuration of an ADF used in the image forming apparatus.
- FIG. 13 and FIG. 14 are flowcharts for explaining the operation during the moving image reading process.
- the ADF 220 includes a pickup roller 224, a registration roller 225, a conveyance roller 226, and the like from the document tray 221 to the intermediate tray 223 and the discharge tray 222 through the space between the second document table 211 and the document holding plate 226 a.
- a document conveyance path 229 including a discharge roller 227 and a rocking plate 228 is formed.
- the ADF 220 positions the rocking plate 228 at the upper position shown by the solid line in FIG.
- the rotation of the pickup roller 224 is started (S23).
- the originals placed on the original tray 221 are sent out one by one to the original conveying path 229 by the pickup roller 224 and the kidnapping plate 224a.
- the sent original moves in the original transport path 229 and temporarily stops in a state where the front end thereof is in contact with the non-rotating registration roller 225.
- the ADF 220 starts rotation of the registration roller 225, the conveyance roller 226, and the discharge roller 227 at a predetermined timing (S24, S25), and the front end of the document stopped in the document conveyance path 229 becomes the first position when the document reading starts.
- 2 Opposes the upper surface of platen 211.
- the document that has passed through the upper surface of the second document table 211 is transported toward the discharge roller 227 by the rotation of the transport roller 226.
- the document whose one-sided image is read at a position facing the upper surface of the second document table 211 is discharged onto a discharge tray 222 by rotation of a discharge roller 227.
- the ADF 220 repeats the processing of S21-S26 for all the originals placed on the original tray 221 during the original scanning single-sided reading processing (S26 ⁇ S21), and there is no next original on the original tray 221. Then, the rotation of all the rollers is stopped and the process is terminated (S27).
- the ADF 220 first starts rotating the pickup roller 224 as shown in FIG. 14 (S 31), and the document placed on the document tray 221. Among them, the uppermost document is sent out into the document transport path 229 and temporarily stopped with the front end thereof in contact with the resist roller 225. After that, the ADF 220 positions the rocking plate 228 at the lower position indicated by the broken line in FIG. (S32, S33).
- the ADF 220 starts the rotation of the registration roller 225, the conveyance roller 226, and the discharge roller 227 at a predetermined timing (S34, S35), and the front end of the document stopped in the document conveyance path 229 reads the document. At the start, it faces the upper surface of second document table 211.
- the original whose image on the first surface has been read at a position facing the upper surface of the second platen 211 is conveyed toward the discharge roller 227 by the rotation of the conveyance roller 226, and further, is rotated by the rotation of the discharge roller 227. Guided on intermediate tray 223.
- the ADF 220 temporarily stops the rotation of all rollers including the discharge roller 227 at a timing before the rotation start force of the registration roller 225 in S35 has passed and the rear end of the document has passed the discharge roller 227. It stops (S36, S37). Thereafter, the ADF 220 reverses the rotation direction of the discharge roller 227 (S38), and guides the document with the front and rear ends reversed into the document transport path 229 via the sub-document transport path 230. The original on which the image on the first side has been read is temporarily stopped with the front end after the reversal abutting on the registration roller 225.
- the ADF 220 starts the rotation of the registration roller 225, the conveyance roller 226, and the discharge roller 227 at a predetermined timing (S39, S40), and places the original on which the image of the first surface has been read on the second original platen 211. And the document holding plate 226a.
- the image of the second side of the document is read when passing between the second platen 211 and the document holding plate 226a.
- the document on which the images on both sides have been read is conveyed toward the discharge roller 227 by the rotation of the conveyance roller 226, and further guided on the intermediate tray 223 by the rotation of the discharge roller 227.
- the ADF 220 temporarily rotates all the rollers including the discharge roller 227 at a timing after a predetermined time has elapsed from the start of rotation of the registration roller 225 in S40 and before the trailing end of the document passes the discharge roller 227. It is stopped (S41, S42). Thereafter, the ADF 220 rotates the discharge roller 227 in the reverse direction (S43), and starts the rotation of the registration roller 225 and the transport roller 226 (S44).
- the ADF 220 rotates the discharge roller 227 forward and moves the rocker plate 228 to the upper position to change the direction of the discharge tray 222. Release (S45 S47). As a result, the original whose two-sided image has been read is Discharged on the discharge tray 222. Thereafter, the ADF 220 determines whether or not there is a document on the document tray 221 (S48). If there is no next document, the ADF 220 waits until the document is discharged onto the discharge tray 222 and rotates all rollers. Is stopped and the process is terminated (S49). If there is a next original, the ADF 220 starts rotating the pickup roller 224 and returns to S32 (S50).
- the ADF 220 when reading the double-sided image, performs the first-side reading transfer step for reading the first-side image and the second-side reading transfer step for reading the second-side image. In addition, an idle transport process for transporting the original without reading the image is performed. As a result, the plurality of originals from which images on both sides have been read are stacked on the output tray 222 and discharged in the same order as set on the original tray 221.
- the main scanning is performed according to the rotation start timing of the registration roller 225 and the document conveyance speed.
- the image reading start position in the direction and the sub-scanning direction changes, and the image reading magnification in the sub-scanning direction changes according to the document conveyance speed.
- FIG. 7 is a block diagram including a control unit of the image forming apparatus.
- the image forming apparatus 100 includes a control unit 400 that controls and controls the image reading unit 200 and the image forming unit 300.
- the control unit 400 includes a CPU 401, an image processing unit 402, a nonvolatile memory 403, and an image memory 404.
- the CPU 401 drives and controls the image reading unit 200, the ADF 220, and the image forming unit 300 according to a program written in the ROM, not shown.
- the nonvolatile memory 403 is configured by an EEPROM or the like, and stores error information and the like calculated during the image position correction work.
- the image memory 404 is composed of an SDRAM or the like, and stores image data.
- the image processing unit 402 is configured by, for example, an ASIC. Image data obtained by converting the output signal from the CCD 234 in the image reading unit 200 into digital data by the A / D converter 239 is input to the image processing unit 402. Further, print data or fax data is input to the image processing unit 402 as image data from an external device (not shown). The image processing unit 402 performs predetermined image processing such as edge enhancement processing on the input image data.
- FIG. 2 is a plan view, a bottom view, and a use state of a correction jig used in a correction operation of an image position and an image magnification (hereinafter, referred to as an image position correction operation) in the image forming apparatus. It is a side view.
- the correction jig 1 which is the image position correction jig of the present invention, is configured such that the paper holding portion 2 (2a, 2b) and the reference member 3 protrude from one side surface of the elongated main body 10, and the other side surface.
- the guide member 13 is protruded from the base member, and anti-slip portions 4 are formed at both ends in the longitudinal direction on the bottom surface.
- At least the bottom surface of the main body 10 is formed by a plane, and the two side surfaces are formed by planes parallel to each other.
- the cross section is rectangular. Is presented.
- the reference member 3 and the guide member 13 are formed of a transparent or translucent material into a flat plate shape, and protrude from the center of the main body 10 in the longitudinal direction.
- Each of the paper holding portions 2a and 2b protrudes from two locations in the longitudinal direction of the main body 10, and presses the original 5 placed on the original platen 210 from above, as shown in FIG.
- the position on the platen 210 is fixed.
- the non-slip portion 4 prevents the correction jig 1 from slipping on the upper surface of the document table 210.
- an index 7 indicating the center position in the length direction of the main body 10 is written on the upper surface of the main body 10. That is, the distance from the index 7 to one end (front end) 10a in the longitudinal direction of the main body 10 (the front side of the image forming apparatus 100) and the other from the index 7 in the longitudinal direction of the main body 10 (the image forming apparatus 100). The distance to the end (rear end) 10b of the rear side is equal.
- the index 7 is constituted by a straight line in a direction orthogonal to the length direction of the main body 10.
- an index 8 that is continuous with the index 7 in the sub-scanning direction is written.
- an index 14 that is continuous with the index 7 in the sub-scanning direction is written.
- the bottom surface of the main body 10 has a second black portion lla, a first white portion l lb, and a first black portion from the front end 10a to the rear end 10b.
- the portion 11c and the second white portion lid are colored.
- the boundary between the first white portion lib and the first black portion 11c coincides with the notation positions of the indices 7 and 8 on the upper surfaces of the main body 10 and the reference member 3 in the longitudinal direction of the main body 10.
- the boundary between the first white portion l ib and the second black portion 11a substantially coincides with the front side of the front paper pressing portion 2a, and the boundary between the first black portion 11c and the second white portion l id.
- the second black portion lla, the first white portion llb, the first black portion 11c, and the second white portion lid are read as the reference image 33 (the second reference image of the present invention). .
- the length of the first black portion 11c is equal to the length of the first white portion lib
- the length of the second black portion 11a is the length of the second white portion lid.
- the lengths of the first black portion 11c and the first white portion lib in the length direction of the main body 10 are each 95 mm.
- the main body 10 has a width of 10 mm and a total length of 250 mm. Therefore, the length of each of the second black portion 11a and the second white portion lid is set to 30 mm.
- the correction jig 1 is arranged such that the length direction thereof is parallel to the main running direction which is the front-back direction of the image forming apparatus 100 during the image position correcting operation.
- the image forming apparatus 100 is placed on the first document table 210 of the image forming apparatus 100.
- the index 7 of the correction jig 1 is set in the main scanning direction (the longitudinal direction of the correction jig 1 (the X direction shown in FIG. 5)). Matches the 13 centerline 13 '.
- the total length (190 mm in this example) of the length of the first black portion 11c and the length of the first white portion l ib is defined as the reference length in the main scanning direction during the image position correction work. I do. Also, the width of the main body 10 (10 mm in this example), which is the width of the first black portion 11c and the first white portion lib, is changed in the sub-scanning direction (the direction orthogonal to the main scanning direction (FIG. The reference length for Y)))) shown in 5).
- FIG. 3 is a diagram showing a first reference image used for an image position correcting operation in the image forming apparatus.
- FIG. 3A is a diagram illustrating a sheet on which a single-sided first reference image is formed
- FIG. 3B is a diagram illustrating a sheet on which a double-sided first reference image is formed
- FIG. 3C is a diagram showing a state when the sheet shown in FIG. 3A is used for an image position correction operation.
- the first reference image 31 for one side is formed on one side of the sheet 41, and the other side of the sheet 41 is formed on the first side. It is blank.
- the front-side first reference image 32a and the back-side first reference image 32b which are the two-sided first reference images 32, are formed on both sides of the sheet 42, respectively.
- the first reference image 32a for the front surface and the first reference image 32b for the back surface are formed upside down on the front and back surfaces of the paper 42.
- These first reference images 31 and 32 are formed on sheets 41 and 42 in the image forming unit 300 of the image forming apparatus 100.
- the two-sided first reference image 32 is formed on both sides of the sheet 42 using the two-sided image forming function of the image forming unit 300.
- the longitudinal directions of the papers 41 and 42 on which the first reference images 31 and 32 are formed are used in accordance with the sub-scanning direction (paper transport direction) of the image forming apparatus 100.
- the papers 41 and 42 are, for example, A4 size, but are not limited thereto.
- the first reference images 31 and 32 are stored in a non-volatile memory (described later) of the image forming apparatus 100 in advance.
- the first reference images 31 and 32 can be stored in an external device such as a computer connected to the image forming apparatus 100.
- the first reference images 31 and 32 are formed near two black band images 311 and 312 formed near the upper and lower ends of the sheets 41 and 42, and below the upper band image 311. And a black triangular image 313.
- Each of the strip images 311 and 312 has a rectangular shape of 190 mm ⁇ 10 mm as an example, and the positions of the sheets 41 and 42 in the short direction coincide with each other.
- the triangular image 313 the positions of the vertices on the upper side of the strips 311 and 312 in the short direction of the paper 41 and 42 are matched.
- Each of the front-side first reference image 32a and the back-side first reference image 32b constituting the two-sided first reference image 32 includes, in addition to the band-shaped images 311 and 312 and the triangular image 313, the front and back surfaces, respectively. "SID EA” and "SIDE B" are shown.
- FIG. As shown in, the upper part of the reference papers 41 and 42 are folded in half in the short direction so that both ends parallel to the longitudinal direction are aligned, and a fold (hereinafter referred to as a fold line) 51 is formed. Be completed.
- FIG. 4 is a plan view showing a state in which a sheet serving as a reference document is fixed on a platen during an image position correction operation in the image forming apparatus.
- the paper 41 as the reference original is fixed and placed on the first platen 210 using the correction jig 1.
- the correction jig 1 is arranged such that the index 14 of the guide member 13 coincides with the center index 213 of the mounting position display plate 212 arranged at the end of the first document table 210, and the outer side surface of the main body 10
- the entire surface of 10d is placed on the first document table 210 in a state where it is in contact with the step portion 212a of the placement position display plate 212.
- the paper 41 as the first reference original on which the single-sided first reference image 31 is printed is short on the inner side surface 10c of the main body 10 of the correction jig 1 placed on the first platen 210. It is inserted between the upper surface of the first document table 210 and the lower surface of the document holder 2 of the correction jig 1 such that the entire surface of one end parallel to the hand direction comes into contact. At this time, the position in the short direction is determined such that the folding line 51 of the paper 41 is located below the index 8 described on the reference member 3 of the correction jig 1. In this state, when an image reading operation is performed by the image reading unit 200, as shown in FIG. 5, a correction image including a reference image 31 serving as a first reference image and a reference image 33 serving as a second reference image. Is read.
- FIG. 8 is a flowchart illustrating an example of a processing procedure at the time of an image position correction operation in the image forming apparatus.
- the image position correcting operation of the image forming apparatus 100 is performed on each image forming apparatus 100 at the time of factory shipment.
- the CPU 401 starts processing in the image position correction work mode, and receives input of image data of the reference image 31 from a personal computer which is an external device for image position correction work.
- S61 reference image information input step
- the CPU 401 subjects the input image data of the reference image 31 to predetermined image processing in the image processing unit 402, stores it in the image memory 404, and stores the reference image 31 at the currently set image forming timing.
- S62 reference image forming step
- the operator When inputting the reference image 31, the operator starts application software for print processing in an external device for image position correction work, and designates the image forming apparatus 100 to be subjected to image position correction work.
- To print the reference image Generally for print processing In the application software, the margins to be formed at the top, bottom, left, and right of an image on a sheet at the time of printing can be set, and the size of the margin affects an image position at which an image is formed on the sheet.
- the triangular image 313 in the reference image 31 is located at the center in the main running direction, and the image memory 404 is set so that the distance L7 shown in FIG. 5 becomes the second reference value.
- the image data of the reference image 31 is supplied to the LSU 313 of the image forming unit 300. Therefore, the operator does not need to set the margin value in the external device.
- the CPU 401 waits for the operation of the start key by the operator (S63). After the operator places the paper (reference document) 41 on which the image of the reference image 31 is formed at a predetermined position on the document table 210 via the correction jig 1 (document placement step), When the start key of the unit is operated, the CPU 401 operates the image reading unit 200 to execute the image reading process on the correction jig 1 and the paper 41, and outputs the correction image including the reference image 33 and the reference image 31.
- the read correction image is stored in the image memory 404 (S64: correction image reading step).
- the CPU 401 measures a specific distance in the correction image stored in the image memory 404, and based on the measured distance, based on the measured distance, the error of the image forming position in the image forming process and the error of the image forming magnification.
- the error, the error of the image reading position and the error of the image reading magnification in the image reading process are measured (S65: image forming unit error measuring step and image reading unit error measuring step). If the error can be calculated properly, the CPU 401 corrects the correction information for correcting the image information read by the image reading unit based on the measured error and the image information to be supplied to the image forming unit.
- S66 ⁇ S67 Image reading section correction information creation step and image forming section correction information creation step
- the created correction information is stored in the non-volatile memory 403 (S69). The position correction work ends.
- step S68 the CPU 401 displays on the operation unit or an external device that the image position correcting operation has failed, and displays the same (S68 ⁇ S70), and ends the image position correcting operation.
- FIG. 9 is another example of a processing procedure at the time of an image position correcting operation in the image forming apparatus. It is a flowchart which shows.
- the image position correcting operation of the image forming apparatus 100 is performed on each image forming apparatus 100 at the time of factory shipment.
- the CPU 401 starts processing in the image position correction work mode, and the image data of the first reference images 31 and 32 is transmitted from a personal computer which is an external device for the image position correction work.
- S1 reference image information input step
- the CPU 401 temporarily stores the input image data of the first reference images 31 and 32 in the image memory 404 after performing predetermined image processing in the image processing unit 402, and stores the first image data at the currently set image forming timing.
- An image forming process is performed for each of the reference images 31 and 32 (S2: reference image forming step).
- application software for print processing When inputting the first reference images 31 and 32, the operator starts application software for print processing in an external device for image position correction work, and operates the image forming apparatus 100 to be subjected to the image position correction work. To instruct the printing process of the first reference images 31 and 32.
- application software for print processing can set the margins to be formed at the top, bottom, left and right of the image on the paper at the time of printing, and the size of the margin affects the position of the image formed on the paper. give.
- the triangular image 313 in the first reference images 31, 32 is located at the center in the main scanning direction, and the distance L7 shown in FIG. 5 becomes the second reference value.
- the image data of the first reference images 31 and 32 is supplied from the image memory 404 to the LSU 313 of the image forming unit 300. Therefore, the operator does not need to set the margin value in the external device.
- the CPU 401 prior to the reference image forming step of S2, the CPU 401 performs a correction operation at the time of image forming processing on a one-sided original using the paper 41 or an image forming process on a two-sided original using the paper 42. Any selection of the correction work at the time of processing is accepted. In response to the selection, the CPU 401 executes the image forming process on only one of the first reference image 31 and the first reference image 32 in the reference image forming step of S2.
- the CPU 401 waits for the operation of the start key by the operator (S3).
- the operator fixes the paper 41 on which the first reference image 31 for one side is formed (one-sided reference document) 41 or the paper 42 on which the first reference image 32 for both sides is formed (two-sided reference document) 42 1 to a predetermined position on the first platen 210 And the start key of the operation unit is operated.
- the CPU 401 When the start key is operated, the CPU 401 first operates the image reading unit 200 to read an image on the correction jig 1 and the paper 41 or 42 placed on the first platen 210. A process is executed to read a first correction image including the second reference image 33 and the first reference image 31 for one side or the first reference image 32 for both sides, and the read first correction image is stored in the image memory 404. (S4: first correction image reading step).
- the CPU 401 again waits for an operation of the start key by the operator (S5).
- the operator places the paper on which the first reference image 31 for one side is formed (one-sided reference original) 41 or the paper 42 on which the first reference image 32 for both sides is formed (two-sided reference original) 42 into the ADF 220.
- the document is set on the document tray 221, and a start key of an operation unit (not shown) is operated.
- the CPU 401 When the start key is operated, the CPU 401 operates the image reading unit 200 and the ADF 220 to execute an image reading process on the paper 41 or 42 conveyed on the second platen, and the first reference for one side.
- the second correction image including the image 31 or the first reference image 32 for both sides is read, and the read second correction image is stored in the image memory 404 (S6: second correction image reading step).
- the CPU 401 measures a specific distance in the first correction image stored in the image memory 404, and based on the measured distance, an error in an image reading position and an image
- the error of the reading magnification, the error of the image forming position and the error of the image forming magnification in the image forming process are measured (S7, S8: fixed original reading section error measuring step and image forming section error measuring step).
- the CPU 401 measures a specific distance in the second correction image stored in the image memory 404, and based on the measured distance, an error in the image forming position and an error in the image forming magnification in the image forming process, The error of the image reading position and the error of the image reading magnification in the image reading process of the original moving method are measured (S9: moving image reading unit error measuring step).
- the CPU 401 corrects the image information read by the fixed image reading unit based on the measured error, and outputs the image information to be supplied to the image forming unit.
- Create correction information to correct the information (S10 ⁇ S11-S13: Fixed image reading unit correction information creation process, image forming unit correction information creation process, and moving image reading (Tower correction information creation step), and the created correction information is stored in the nonvolatile memory 403 (S14).
- the second correction image reading step in S6 and the ADF error measurement step in S9 can be performed before the moving image reading unit correction information creating step in S13.
- the ADF 220 does not have a double-sided image reading function, or does not perform correction at the time of image forming processing on a double-sided document, image formation is performed on the double-sided first reference image 32.
- the operator who does not need to set the paper 41 on which the single-sided first reference image has been formed in the document tray 221 of the ADF 220 prior to the second correction image reading step.
- the second correction image is configured by the single-sided first reference image 31.
- the image reading unit 300 when the image forming unit 300 forms an image on a sheet of a document image read by the image reading unit 200 from a document placed on the document table 210, the image reading unit The error generated at the time of the image reading process at 200 and the error generated at the time of the image forming process at the image forming unit 300 are superimposed on each other, resulting in errors in the image position and image magnification between the output image and the original image.
- the image forming unit for the reference image 31 stored in the image forming apparatus 100 in advance, the image forming unit
- the image forming unit 300 uses the original image read by the image reading unit 200. Errors in the image position and image magnification between the output image on the paper and the original image, which occur when an image is formed on the paper, are stored in advance, the reference image 31 is shifted, and the image forming unit 300 outputs the error. It is equal to the error of the image position and image magnification between the read image and the reference image 31 that occur when the image on the paper 41 is read by the image reading unit 200 after the image is formed on 41.
- the image forming apparatus 100 when the image formed by the image forming unit 300 is formed on a sheet of a document image read by the image reading unit 200 from a document conveyed onto the second document table 211 by the ADF 220.
- the error that occurs when the document is transported by the ADF 220, the error that occurs when the image is read by the image reading unit 200, and the error that occurs when the image is formed by the image forming unit 300 overlaps the output image and the document image. This causes errors in the image position and image magnification.
- an image is formed on the paper 41 or 42 by the image forming unit 300, and the image is read using the paper 41 or 42 as a reference original.
- the second correction image is read by the unit 200, errors in the image position and image magnification between the second correction image and the reference image 31 or 32 occur during the image forming process and during the document transport in the ADF 220. Error and an error generated during the image reading process are superimposed.
- the image forming unit 300 forms an image on a sheet of the original image read by the image reading unit 200 from the original conveyed by the ADF 220, an image between the output image on the sheet and the original image is generated.
- the error of the position and the image magnification is obtained by forming the image of the first reference image 31 or 32 stored in advance on the paper 41 or 42 by the image forming unit 300 on the paper 41 or 42 and then using the ADF 220 to place the paper 41 or 42 on the second platen 211.
- the image correction method of the present invention after the image forming unit 300 forms an image on the paper 41 or 42 with the first reference image 31 or 32 stored in advance, first, the first document Based on the result of reading the first reference image 31 of the paper 41 or 42 on the table 210 together with the reference image 33 of the correction jig 1 by the image reading unit 200, the fixed image reading unit And the error in the image forming unit 300 are individually measured. Next, the error in the moving image reading unit is measured based on the result of reading the first reference image 31 or 32 of the sheet 41 or 42 on the second document table 211 by the image reading unit 200 and the error in the image forming unit 300. .
- the image reading unit 200, the image forming unit 300, and the ADF 220 correct each of the measured errors to form an image at an appropriate position and at an appropriate magnification during image forming processing in the image forming apparatus 100. It can be so.
- the first embodiment is an example in which the error is measured using the paper 41 on which the first reference image 31 for one side is formed
- the second embodiment uses the paper 42 on which the first reference image 32 for both sides is formed. This is an example in which the error is measured.
- the paper 41 on which the reference image 32 is formed or the paper 41 on which the reference image 32 is formed is fixedly placed at a predetermined position on the document table 210 via the correction jig 1, a document fixing method using a fixed image reading unit Is performed.
- the first correction image includes the reference image 31 of the correction jig 1 together with the reference image 31 of the paper 41.
- the image reading process is performed on the correction jig 1 and the paper 41 placed on the document table 210 in the state shown in FIG. 4 to include the reference image 33 and the reference image 31 shown in FIG. 1 Read the correction image.
- the first mirror base 231 is detected at the home position HP at the time of image reading processing of the original fixing method. Correction is performed from the HP sensor change line corresponding to the timing at which the output signal of the HP sensor changes. Measure the distance L1 from the jig 1 to the end line Z. This distance L1 is the compensation jig
- the measurement is performed using the image of the first black portion lie or the second black portion lid. That is, the distance L1 is measured based on the timing when the image data changes from the black portion of the correction jig 1 to the white region of the document.
- the distance L1 is represented by the number of pixels.
- a position obtained by subtracting the width L2 (1 Omm in this example) of the correction jig 1 from the detected end line Z of the correction jig 1 is defined as a reading start position Y1 in the sub-scanning direction.
- the reading start position Y1 is stored in the non-volatile memory 403 as the position of the leading edge of the document in the actual image reading process.
- the total length L3 of the length of the first white portion lib and the length of the first black portion 11c was measured, and the read total length L3 was compared with the length of the band image 311 in the reference image 31.
- the ratio is calculated as an error of the image reading magnification in the main scanning direction in the fixed image reading unit.
- the error of the image reading magnification in the main scanning direction in the fixed image reading unit is reflected only in the image reading process in the image reading unit 200, and is not reflected in the image forming process in the image forming unit 300.
- This total length L3 is also represented by the number of pixels.
- the total length of the first white portion l ib and the first black portion 11c in the correction jig 1 is set to be the same as the length in the longitudinal direction of the band image 311 in the reference image 31, and You.
- the error of the reading magnification in the main scanning direction is specifically calculated by the following equation 1.
- the number of pixels in the longitudinal direction of the strip image 311 in the reference image 31 is 190 mm in the longitudinal direction of the strip image 311.
- the image is read with an increase of 0.27%.
- the reading magnification error in the main scanning direction is determined by the non-volatile memory provided in the image forming apparatus 100. Re 403.
- the center line 7 'of the correction jig 1 is extracted, and the distance L4 from the reading start cylinder to the center line in the main scanning direction is measured.
- the measured distance L4 is compared with the designed center position, and the error of the center position (the error shown in FIG. 6) is calculated.
- the error of the center position is specifically calculated by the following equation (2).
- the designed number of pixels of the distance L4 is ,
- the error A2 in the reading start position is calculated by taking into account the error in the image reading magnification in the main scanning direction.
- the calculated error in the center position is stored in the nonvolatile memory 403 provided in the image forming apparatus 100 as an error in the reading start position in the main scanning direction (error L5 shown in FIG. 6).
- the measurement of the error in the image forming unit 300 is performed by appropriately referring to each value obtained at the time of measuring the error in the image reading unit 200.
- the distance L6 from the reading start position in the main scanning direction to the end 311a of the end portions 311a and 311b of the band image 311 which is closer to the reading start position is measured.
- the distance L6 is represented by the number of pixels to be read.
- the number of pixels is S.
- the error of the reading start position in the main scanning direction in the image reading unit 300 since the error of the reading start position in the main scanning direction in the image reading unit 300 has already been obtained, this error is obtained by subtracting the error from the number of pixels S (number of pixels). Is compared with the first reference value.
- the first reference value is the number of pixels corresponding to the distance between the reading start position in the main scanning direction set by design and the end 31 la of the band image 311 in the reference image 31.
- main The error of the image formation start position in the scanning direction is specifically calculated by the following equation (3).
- the design distance L6 is
- the error A3 of the image formation start position in the main scanning direction is calculated by taking the above errors A1 and A2 into consideration.
- A3 406- ⁇ (P3-A2) X A1 + 100 ⁇ (pixel)
- the calculated error of the image formation start position in the main scanning direction is stored in the nonvolatile memory 403 provided in the image forming apparatus 100.
- the distance L7 from the end line Z of the image position correction jig 1 to the side of the side parallel to the longitudinal direction of the belt-shaped image 311 on the side of the correction jig 1 is measured.
- the distance L7 is represented by the number of pixels to be read.
- the number of pixels is T.
- the error (number of pixels) is calculated by dividing the error by the number of pixels T Compare with the reference value of 2.
- the second reference value is the distance between the reading start position Y1 in the sub-scanning direction set by design and the position K on the correction jig 1 side of the band image 311 in the reference image 31 stored in advance. Is a pixel value corresponding to.
- the error of the image formation start position in the sub-scanning direction is specifically calculated by the following Expression 4.
- the calculated error of the image forming start position in the sub-scanning direction is stored in the nonvolatile memory 403 provided in the image forming apparatus 100.
- the length L8 of the band image 311 in the main running direction is measured.
- the distance L8 is represented by the number of read pixels.
- the number of pixels is U.
- the measured distance L8 is compared with a third reference value.
- the third reference value is the number of pixels corresponding to the length of the band image in the reference image 31 stored in advance.
- the error of the image forming magnification in the main scanning direction in the image forming unit 300 is calculated by the following Expression 5 in consideration of the error in the image reading magnification of the image reading unit 200 in the main scanning direction.
- the calculated error in the image forming magnification in the main scanning direction is stored in a non-volatile memory provided in the image forming apparatus 100.
- the distance L9 between the two band images 311 and 312 is measured.
- the distance L9 is represented by the number of read pixels.
- the number of pixels is V.
- the measured distance 9 is compared with a fourth reference value.
- the fourth reference value is the number of pixels corresponding to the distance between the two band images 311 and 312 in the reference image 31 stored in advance.
- the error of the image forming magnification in the sub-scanning direction in the image forming unit 300 is specifically calculated by the following equation (6).
- the calculated error in the image forming magnification in the main scanning direction is stored in the nonvolatile memory 403 provided in the image forming apparatus 100.
- the paper 41 on which the reference image 31 is formed is set in the document tray 221 of the ADF 220, and the image reading unit 200 performs an image reading process.
- a second correction image read as shown in FIG. 15 is used.
- the paper 41 is set on the document tray 221 of the ADF 220 such that the image forming surface faces upward and the images 311, 312, and 313 are read in this order.
- the second correction image includes only the reference image 31 on the paper 41.
- the measurement of the error in the ADF 220 is performed when the error in the image forming unit 300 is measured. This is performed by appropriately referring to the values obtained. This is because the image on the paper 41 read by the second document table 211 via the ADF 220 includes an error in the image forming unit 300 during image formation.
- the distance L6 from the reading start position in the main scanning direction to the end 311a of the end portions 311a and 311b of the band image 311 which is closer to the reading start position is measured.
- the distance L6 is represented by the number of pixels to be read.
- the result (the number of pixels) obtained by subtracting this error from the number of pixels is used as the first reference value.
- the first reference value is the number of pixels corresponding to the distance between the reading start position ⁇ [in the main scanning direction set by design and the end 311a of the band image 311 in the reference image 31.
- the error of the image formation start position in the main running direction is specifically calculated by the following equation.
- the calculated error of the reading start position in the main scanning direction is stored in the nonvolatile memory 403 provided in the image forming apparatus 100.
- the error in the image forming start position in the main scanning direction in the image forming unit 300 is measured in consideration of the error in the image reading starting position in the main scanning direction in the image reading unit 200. Therefore, the error of the reading start position in the main scanning direction measured here is an error mainly generated in the original feeding operation of the ADF 220 excluding the influence of the mounting error of the fixed image reading unit in the image reading unit 200 and the like. .
- a distance L7 from a front end of the second correction image to a position of a side parallel to the longitudinal direction of the belt-shaped image 311 on the side of the correction jig 1 is measured.
- the distance L7 is represented by the number of pixels to be read, and here is the number of pixels.
- the result (the number of pixels) obtained by subtracting this error from the number of pixels is used as the second base.
- the second reference value is the distance between the reading start position Y1 in the sub-scanning direction set by design and the position of the band-shaped image 311 in the pre-stored reference image 31 on the correction jig 1 side.
- the corresponding pixel value is specifically calculated by the following equation 4 ′.
- the calculated error of the reading start position in the sub-scanning direction is stored in the nonvolatile memory 403 provided in the image forming apparatus 100.
- the error in the image forming start position in the sub-scanning direction in image forming section 300 is measured in consideration of the error in the image reading start position in the sub-scanning direction in image reading section 200. Therefore, the error of the reading start position in the sub scanning direction measured here mainly occurs in the original feeding operation of the ADF 220 excluding the influence of the mounting error of the fixed image reading unit in the image reading unit 200. It is an error.
- the distance L9 between the two band images 311 and 312 is measured.
- the distance L9 is represented by the number of pixels to be read, and here, the number of pixels is V '.
- the measured distance 9 is compared with the fourth reference value.
- the fourth reference value is the number of pixels corresponding to the distance between the two band images 311 and 312 in the reference image 31 stored in advance.
- the error of the image forming magnification in the sub-scanning direction in the image forming unit 300 is specifically calculated by the following equation 6 ′.
- the calculated error in the image forming magnification in the main scanning direction is stored in the nonvolatile memory 403 provided in the image forming apparatus 100.
- the error in the image reading magnification in the main scanning direction in the image read by the second document table 211 from the document conveyed by the ADF 220 is caused by the image reading in the main scanning direction in the fixed image reading unit measured in A (2) above. Since it is equal to the magnification error, it is not necessary to measure it as an error in the moving image reading unit.
- the image reading unit 200 and the image forming unit 300 correct the image position and the image magnification in the respective processes of the scanner mode and the copy mode using the ADF 220 in the image forming apparatus 100. .
- the image position correcting operation of the image reading unit and the image forming unit during the processing in each mode will be described below.
- the on / off timing of the original sensor 229a in the ADF 220 is controlled. This is corrected in advance by controlling the rotation start timing of the registration rollers 225 and controlling the rotation speeds of the rollers 224 to 227. Therefore, it is not necessary to correct the error of the moving image reading unit for each of the document images read by the image reading process of the document moving method.
- the following image position correction work is performed in the image reading unit 200. .
- the image data read by the image reading unit 200 is read in the main scanning direction and the sub-scanning direction in each of the scanning start position error and the error.
- the output is corrected by correcting the reading start position error in the sub-scanning direction.
- the image data read by the image reading unit 200 is corrected in the main scanning direction to a value obtained by multiplying the reciprocal of the error of the image reading magnification in the main scanning direction and output.
- the correction of the image reading magnification is performed by a so-called electronic zoom that expands and contracts in the image memory.
- the image reading section 200 In the copy mode in which the image forming apparatus 100 is used as a copier and image data read by the image reading section 200 is formed in the image forming section 300 to form an image on paper, the image reading section 200 and the image forming section 300 The following image position correction work is performed.
- the image data read by the document reading unit 200 is calculated by adding the error of the reading start position in the main scanning direction and the error of the image forming start position in the main scanning direction and the sub-scanning direction, and Then, an amount obtained by adding the error of the reading start position in the sub-scanning direction and the error of the image forming start position is corrected to form the image on the paper.
- the amount obtained by adding the error of the reading start position and the error of the image forming start position can be stored in the memory of the image forming apparatus 100 in advance.
- the image data read by the document reading section 200 is a magnification for correcting an error in the image reading magnification in the main scanning direction and an error in the image forming magnification in each of the main scanning direction and the sub scanning direction. And enlarges or reduces the image reading magnification error in the sub-scanning direction and the image formation magnification error on a sheet by using a magnification that corrects the error.
- a magnification for correcting an error in the image reading magnification and an error in the image forming magnification can be stored in the memory of the image forming apparatus 100 in advance.
- the magnification obtained by multiplying the error of the image reading magnification in the main scanning direction and the error of the image forming magnification in the sub-scanning direction is stored in the memory of the apparatus, and the image magnification is used by using this magnification. It can also be corrected.
- the enlargement or reduction of an image is performed by a so-called electronic zoom that enlarges or reduces image data in an image memory.
- the CPU 401 executes an image reading process for the correction image in the image reading unit 200, and the AZD converter 239 converts the electric signal output by the CCD 234 according to the amount of received light into a digital image.
- the image data is input to the image processing unit 402 as image data.
- the image processing unit 402 performs predetermined image processing on the input image data and stores the image data in the image memory 404.
- the CPU 401 reads out a necessary part of the image data from the image memory 404, and measures and calculates an error.
- the CPU 401 stores the measured and calculated error information in the nonvolatile memory 403.
- the CPU 401 reads error information from the nonvolatile memory 403 and supplies the read error information to the image processing unit 402 and the image forming unit 300.
- the image forming unit 300 starts the operation of the ADF 220 at a timing adjusted based on the supplied error information, and conveys the document so that the document faces the document table 211 at appropriate timing.
- the image processing unit 402 performs image processing on the image data input from the image reading unit 200 based on the supplied error information, and stores the image data after the image processing via the image memory 404 as an image. Output to the exposure unit 313 of the forming unit 300.
- the exposure unit 313 irradiates the photosensitive drum 311 with image light modulated by the input image data at a timing based on the error information. Further, the image forming unit 300 guides the sheet between the photosensitive drum 311 and the transfer unit 315 at a timing adjusted based on the supplied error information.
- FIG. 10 is a diagram illustrating an example of an exposure unit provided in the image forming apparatus.
- the exposure unit 313 is, for example, a laser scan unit (LSU) that exposes the photosensitive drum 311 with a laser beam modulated by image data.
- the LSU 313 forms an image of the laser beam emitted from the semiconductor laser 3112 on the surface of the photosensitive drum 311 via a collimator lens 3113, a cylindrical lens 3116, a polygon mirror 3120, an f- ⁇ lens 3123, a folding mirror 3124, and the like.
- the collimator lens 3113 converts the laser light, which is the diffused light emitted from the semiconductor laser 2, into parallel light.
- the cylindrical lens 3116 focuses the laser beam in the sub-scanning direction, which facilitates the correction of the error of the irradiation position on the photosensitive drum 311 caused by the inclination of the reflection surface of the polygon mirror 3120.
- the polygon mirror 3120 rotates at a constant speed in the direction of the arrow, and exposes and runs on the surface of the photosensitive drum 311 in the main scanning direction by the laser light reflected on each reflecting surface.
- the lens 3123 deflects the laser beam, which moves in the main running direction at a constant angular velocity with the rotation of the polygon mirror 3120, so that it moves on the surface of the photosensitive drum 311 at a constant speed to form an image.
- the irradiation position on the photosensitive drum 311 due to the inclination of the reflection surface of the polygon mirror 3120 is corrected.
- the laser light is converted into scanning light as image light that runs in the main scanning direction on the surface of the photosensitive drum 311 in order to form an electrostatic latent image on the surface of the photosensitive drum 311.
- a mirror 3126 is arranged outside the image forming area within the scanning range of the laser beam passing through the f- lens 3123, and the laser beam is Light is distributed to the BD sensor 3127.
- the control unit of the LSU 313 synchronizes the image writing timing of each scanning line based on the detection timing of the laser beam by the BD sensor 3127.
- the laser light modulation by the image data is started at a timing when a predetermined time has elapsed since the BD sensor 3127 detected the laser light.
- the predetermined time is a time required from when the laser beam is detected by the BD sensor 3127 to when the writing start position of the image on the photosensitive drum 311 is exposed. Therefore, by increasing or decreasing the predetermined time, the position of the image formed on the sheet via the photosensitive drum 311 in the main scanning direction changes. Also, by adjusting the time required to start modulating the laser beam with the image data, the position of the image formed on the sheet via the photosensitive drum 311 in the sub scanning direction changes. I do.
- the error of the ADF 220 when reading the two-sided image is measured using the paper 42 on which the first-side reference image 32 is formed on each of the front and back surfaces.
- the first reference image 32 for both sides is a first reference image for the surface on which “rsiDE B” is written. It consists of a quasi-image 32a and a back-side first criterion image 32b on which the letters "SIDE A" are written.
- the front and rear ends in the transport direction are reversed between when reading an image from the front side of the document and when reading an image from the back side of the document, and the reading direction of the image is reversed.
- the back side image of the document is read in a state where the upside down direction is inverted with respect to the front side image of the document.
- the first reference image 32a for the front surface and the first reference image 32b for the back surface are formed on the front and back surfaces of the paper 42 in a state where the upside down direction is reversed.
- the first reference image 32a for the front side and the first reference image 32b for the back side are read in a state in which the upper and lower sides coincide.
- the paper 42 on which the first reference image 32 is formed is placed with the first reference image 32b for the back side facing upward as shown in FIG. As shown in B), with the first reference image 32a for the front surface facing upward and fixedly placed at a predetermined position on the first platen 210 via the correction jig 1, the fixed image reading unit The reading process of the first correction image is performed.
- a fold line 52 that divides the length in the short direction, which is the main scanning direction, into two is formed on the sheet 42.
- the error in the fixed image reading unit is measured in the same manner as in the process A.
- the paper 42 is set with the back-side first reference image 32b facing upward as shown in FIG. 16 (A), and with the front-side first reference image 32a facing up as shown in FIG. 16 (B).
- the image reading process is performed on both sides, and the first correction image for the front surface and the first correction image for the back surface are read in advance. You may measure both the error at the time of image formation. If there is a difference between the error at the time of forming the front image and the error at the time of forming the back image in the image forming unit 300, the measurement result of the error at the time of reading the front image at the moving image forming unit (ADF220) described later and the Error measurement results.
- the image forming unit ADF220
- the error of the moving image reading unit is measured.
- the first correction image including the first printing surface image 32a and the second reference image 33 of the correction jig 1, or the second printing surface image 32b and the second reference image 33 of the correction jig 1,
- the error in the image forming unit 300 is measured in the same manner as in the process of B in the first embodiment, using any of the first correction images including.
- the paper 42 on which the first reference image 32 for both sides is formed on the front and back sides is set in the document tray 221 of the ADF 220, the image reading unit 200 performs the double-sided image reading process, and the reading is performed.
- the second correction image is used.
- the paper 42 is placed so that the first printing surface on which the first reference image 32a for the front side is formed faces upward, and the images 311, 312, and 313 are read in this order.
- Set The ADF 220 conveys the paper 42 two times continuously while turning over the paper 42 so that the front and back surfaces of the paper 42 face the second platen 211 sequentially.
- the first reference image 32a for the front surface and the first reference image 32b for the back surface formed on the paper 42 are read in this order as the second correction image for the front surface and the second correction image for the back surface.
- the error in the reading start position in the main scanning direction and the An error in the reading start position in the scanning direction and an error in the image reading magnification in the sub-scanning direction are measured.
- the measured error is stored in the non-volatile memory 403 provided in the image forming apparatus 100 as an error when reading the front image and when reading the back image.
- the image reading unit 200 and the image reading unit 200 are processed in the same manner as in the first embodiment at the time of the respective processes in the scanner mode and the copy mode for the two-sided document using the ADF 220 in the image forming apparatus 100.
- Image position in forming unit 300 And the image magnification is corrected.
- the control of the on / off timing of the document sensor 229a and the control of the registration roller 225 The correction is made in advance by controlling the rotation start timing and controlling the rotation speed of the rollers 224 to 227.
- correction is performed using the error measured for the front side first reference image 32a, and when reading the back side image of the document, the error measured for the back side first reference image 32b is calculated. The correction is performed using this.
- the error of the image reading magnification in the sub-scanning direction in the fixed image reading unit has not been calculated. Therefore, in the correction of the image forming magnification error in the sub-scanning direction in the image forming unit 300, the error in the image reading magnification in the sub-scanning direction in the fixed image reading unit is not considered (see Equations 5 and 6). ).
- the error of the image reading magnification in the sub-scanning direction in the fixed image reading unit is also corrected. The operation of placing the correction jig 1 and the correction original on the platen 210 and reading the image of the correction jig 1 and the reference image 31 as the correction image is the same as in the first embodiment. .
- the error of the fixed image reading unit is measured using an image read from the back surface of the correction jig 1.
- the width of the correction jig 1 is measured, and the measured width is used as the width of the rectangular image 311 in the sub-scanning direction of the reference image 31 stored in the image memory 404. And calculate the error between them as the error in the image reading magnification in the sub-scanning direction. Put out.
- the calculated error in the image scanning magnification in the sub-scanning direction is reflected only during the image reading process, and is not reflected during the image forming process.
- the width of the correction jig 1 is measured as the number of pixels in the correction image.
- the error in the image reading magnification in the sub-scanning direction is caused by the fact that the width of the correction jig 1 is set to be the same as the width of the rectangular image 311 in the reference image 31 in the width direction.
- the number of pixels at a distance L9 between the two rectangular images 311 and 312 in the sub-scanning direction is measured as in the first embodiment.
- the measured distance L9 is compared with a fourth reference value.
- the fourth reference value is an interval between two rectangular images 311 and 312 in the reference image 31 stored in the image memory 404. From this measurement result, the error in the image forming magnification in the sub-scanning direction is
- the image data read by the image reading unit 200 is sub-scanned.
- the size is corrected by multiplying the reciprocal of the error of the image reading magnification in the sub-running direction. Correction of image reading magnification
- the image forming apparatus 100 When the image forming apparatus 100 is used as a printer, image data input from an external device such as a personal computer, etc., in the printer mode in which the image forming unit 300 forms an image on paper, the image data input from the external device is used.
- an image In the sub-scanning direction, an image is formed on a sheet with a size enlarged or reduced by the reciprocal of the error of the image forming magnification in the IJ running direction.
- the enlargement / reduction of an image is performed by a so-called electronic zoom which enlarges / reduces image data in an image memory.
- the image data read by the image reading section 200 is read in the copy mode in which the image forming section 300 forms an image on a sheet.
- the size obtained by multiplying the error (magnification) of the image reading magnification in the sub-scanning direction and the error (magnification) of the image forming magnification in the sub-scanning direction by the reciprocal of the magnification (magnification for correction) To form an image on paper.
- a copy magnification other than the equal magnification is set, an image enlarged / reduced by electronic zoom processing at a magnification obtained by multiplying the correction magnification by the copy magnification is formed on paper. Further, a magnification obtained by multiplying the error of the image reading magnification in the sub-scanning direction by the error of the image forming magnification in the sub-scanning direction can be stored in the nonvolatile memory 403 as the error of the image magnification in the sub-scanning direction.
- a correction jig having an L-shaped shape with a colored back surface as shown in FIG. 11 is used.
- the reference image 31 is attached to the second black portion lla, the first white portion llb, the first black portion 11c, and the second white portion lid, which are the same as the correction jig 1.
- Two black portions l ie and l lf corresponding to the two rectangular images 311 and 312 are formed.
- This correction jig: ⁇ is applied to the reference image 31 in the image forming apparatus 100.
- the correction image is read by being placed on the document table 210 together with the formed paper.
- the correction image includes the reference image 31 of the correction jig: ⁇ together with the reference image 31 of the paper 41.
- a fixed-size sheet such as an A4 size sheet on which no image is formed is placed on the platen 210 together with the correction jig 1 or the correction jig: ⁇ . Place it on the paper and measure the distance between the two parallel edges of the paper. This measurement result can be compared with the width and length of A4 size paper to determine the error in the image reading magnification.
- the correction jig 1 By coloring the lower surface of the periphery of the document table 210 in the same manner as the back surface of the correction jig 1 or: ⁇ , the correction jig 1 or may be omitted.
- the first to third embodiments are based on the premise that the image forming apparatus 100 places a document on the basis of the center of the document table 210 in the main scanning direction.
- the image forming apparatus 100 based on one end in the main scanning direction is used as a reference.
- the present invention can also be applied to the present invention.
- the configuration of the reference images 31 to 34 described in the above embodiment is not limited to the above embodiment.
- the colors of the reference images 31 to 34 are composed of black and white in the above embodiment, other colors may be used as long as the boundaries can be determined.
- a mark for example, a bar code
- the data can be added to the reference image so that the data can be identified, and a description of the method of use can be added to a part of the reference image.
- the reading start position error (correction amount) in the main scanning direction and sub-scanning direction is indicated by the number of pixels. In addition, it can be indicated by time (reading start timing) or distance. It is also possible to indicate which pixel in the image memory the starting pixel after correction is. As a correction method, the position of the image data on the image memory is shifted.
- the read image data is stored in the image memory without performing the magnification correction, and the magnification correction is performed by converting the storage area of the image data in the image memory to a state where there is no reading magnification error when outputting the image data. I do.
- the read image data is stored in the image memory in a state converted by the correction magnification, and the image data in the image memory is output as it is when the image data is output.
- a method of changing the sheet conveyance timing can be used.
- a method of changing the paper transport speed can be used.
- the first reference images 31 and 32 are stored in the external device of the personal computer, and the reference image is transmitted to the external device connected to the image forming apparatus during the image position correcting operation.
- the following method can be adopted.
- the reference image is stored in the non-volatile memory in the image forming apparatus, and the reference image is read from the internal non-volatile memory during the image position correction work (reference image information reading step).
- the present invention can be implemented even during maintenance by a service person.
- the reference image is stored in an external recordable recording medium such as an FD or CD, and the reference image is read from the recording medium during the image position correction work (reference image information reading step).
Abstract
Description
Claims
Priority Applications (1)
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US10/557,179 US7502147B2 (en) | 2003-05-21 | 2004-05-19 | Image position correcting method, image position correcting jig, and image formation device |
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JP2003-144072 | 2003-05-21 | ||
JP2003144072A JP3880544B2 (ja) | 2003-05-21 | 2003-05-21 | 画像補正方法、画像補正用治具、及び、画像形成装置 |
JP2003-168060 | 2003-06-12 | ||
JP2003168060A JP2005003984A (ja) | 2003-06-12 | 2003-06-12 | 画像補正方法及び画像形成装置 |
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CN101917536A (zh) * | 2009-03-30 | 2010-12-15 | 夏普株式会社 | 图像读取装置以及图像形成装置 |
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JP4250000B2 (ja) * | 2003-03-03 | 2009-04-08 | 東芝テック株式会社 | 画像読取装置および画像読取方法 |
US7894105B2 (en) * | 2005-01-18 | 2011-02-22 | Canon Kabushiki Kaisha | Image reading unit and image reader |
US7626737B2 (en) * | 2005-03-31 | 2009-12-01 | Xerox Corporation | Wide format ROB assembly |
JP4270185B2 (ja) * | 2005-09-15 | 2009-05-27 | ブラザー工業株式会社 | 画像処理装置 |
JP2007143014A (ja) * | 2005-11-22 | 2007-06-07 | Fuji Xerox Co Ltd | 画像読み取り装置および画像読み取り方法 |
JP4871061B2 (ja) | 2006-08-03 | 2012-02-08 | 株式会社リコー | 画像処理装置、プログラムおよび処理設定方法 |
US8081353B2 (en) * | 2007-12-12 | 2011-12-20 | Lexmark International, Inc. | Enhanced illuminated scanning unit reference marker |
KR100985035B1 (ko) * | 2008-10-14 | 2010-10-05 | 한국과학기술연구원 | 스캐닝 장치의 움직임 추적 방법 |
JP5106366B2 (ja) * | 2008-12-10 | 2012-12-26 | キヤノン株式会社 | 画像読取システム及び画像読取装置および画像読取システムの制御方法 |
JP4978815B2 (ja) * | 2009-10-30 | 2012-07-18 | ブラザー工業株式会社 | 画像読取装置、画像形成装置及び画像読取制御プログラム |
JP5517690B2 (ja) * | 2010-03-25 | 2014-06-11 | デュプロ精工株式会社 | 用紙加工装置 |
JP4952814B2 (ja) * | 2010-03-30 | 2012-06-13 | ブラザー工業株式会社 | 画像読取装置 |
JP6023495B2 (ja) * | 2012-07-27 | 2016-11-09 | キヤノン株式会社 | 画像読取装置 |
JP2015150647A (ja) * | 2014-02-14 | 2015-08-24 | ブラザー工業株式会社 | 保持部材及び切断装置 |
JP6252263B2 (ja) * | 2014-03-11 | 2017-12-27 | 富士ゼロックス株式会社 | 画像の読取装置および画像形成装置 |
JP6295753B2 (ja) * | 2014-03-18 | 2018-03-20 | 富士ゼロックス株式会社 | 画像形成装置 |
US10015361B2 (en) * | 2015-07-29 | 2018-07-03 | Ricoh Company, Ltd. | Image measurement sheet, image forming apparatus, and method |
JP6946983B2 (ja) * | 2017-11-30 | 2021-10-13 | 株式会社リコー | 位置検出装置、画像読取装置、画像形成装置、プログラムおよび位置検出方法 |
JP2019193978A (ja) * | 2018-05-01 | 2019-11-07 | コニカミノルタ株式会社 | 画像形成装置 |
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