JP2013013048A - Image reader, image forming apparatus, image reading method and image reading program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve image quality of images of an original which is obtained by reading the images by a plurality of image sensor arrays loaded on a carriage moving in a sub-scanning direction and connecting them.SOLUTION: When the images of the original G read by CCD 11a and 11b are connected in a prescribed connection position and are set to be an image for one line while a carriage loading reduction optical means consisting of: the plurality of CCD 11a and 11b; mirrors 13a, 13b to 15a and 15b; and lenses 12 and 12b, a light source and the like is moved to a sub-scanning direction, the image reader 1 reads a position detection pattern member 4 where a position detection line showing the connection position is formed, and corrects the connection position of the images of the original G, which the CCD 11a and 11b read from the images of the position detection line.

Description

  The present invention relates to an image reading apparatus, an image forming apparatus, an image reading method, and an image reading program. More specifically, the present invention uses a plurality of image sensor arrays arranged in the main scanning direction while moving a carriage on which a light source or the like is mounted. The present invention relates to an image reading apparatus, an image forming apparatus, an image reading method, and an image reading program that read an image of a stationary document.

  In an image reading apparatus such as a scanner apparatus, a copying apparatus, or a composite apparatus that reads an image of an original, especially an image reading apparatus that reads an image of a wide original such as an A0 size, in order to reduce the cost, it is larger than the maximum original original size. A wide-size document is read by a sensor unit in which a plurality of image sensor arrays of a small size, for example, A3 or A4 size, are arranged in the main scanning direction.

  In such an image reading apparatus having a sensor unit having a plurality of image sensor arrays, a carriage moving type that reads a document image by driving a carriage mounted with a light source, a mirror, and the like is used. There is a document transport type that reads with a stationary optical system, but in the case of an image reading apparatus having a plurality of image sensor arrays, the image data read by the plurality of image sensor arrays is appropriately connected to form a single image sensor array. It is necessary to perform a seam correction process (image synthesis process) for synthesizing the image data as if it were read in step (b). The carriage movement type image reading apparatus cannot avoid the vibration of the mirror mounted on the carriage as the carriage moves, and the image of the document read by the plurality of image sensor arrays due to the vibration of the mirror. However, in the main scanning direction, particularly in the main scanning direction end, the light reflected by the moving and vibrating mirror is photoelectrically converted by the image sensor array to read the image of the document. As a result, when the images read from a plurality of image sensor arrays are joined even when the image is read with only one image sensor array while moving the carriage, even if the vibration is acceptable. In some cases, the image degradation at the joint portion of the image sensor array exceeds the allowable limit.

  Conventionally, in a carriage movement type image reading apparatus, a reference pattern for correcting the stitching of the reading area of each image sensor array is provided near the shading correction reading unit, and the reference pattern is moved while moving the image sensor array. And a technique for correcting the joining of the reading areas of the image sensors based on the reference data when the reference pattern is read has been proposed. More specifically, the carriage movement type image reading apparatus moves a carriage carrying a scanning optical system including the image sensor array in the sub-scanning direction at a predetermined reference reading speed lower than the original reading speed by an optical system driving unit. The reference data is created by reading the reference pattern (see Patent Document 1).

  In other words, the conventional technique performs joint correction of the reading area of the image sensor array based on the result of reading the reference pattern near the shading correction reading unit before reading the document.

  However, in the prior art described in the above publication, since the correction of the connection portion of the image sensor is performed based on the reading result of the reference parameter read before reading the document, the mirror when the carriage is moving, etc. Therefore, it is necessary to improve the correction of the joint part appropriately considering the influence of the mirror vibration that cannot be avoided in the case of the carriage moving type. It was. In particular, in the carriage movement type, when the mirror vibrates due to the movement of the carriage, the read image is read while moving in the main scanning direction (particularly, moving largely at the end in the main scanning direction). In the case of reading with the image sensor, the permissible vibration becomes unacceptable when the images of a plurality of image sensors are joined together, and improvement is necessary for improving the image quality.

  Accordingly, an object of the present invention is to more accurately correct a shift in an image at a connecting position portion of a plurality of image sensors.

  In order to achieve the above object, the present invention reduces the reflected light of the light irradiated on the document from the light source to each image sensor array of the image reading means having a plurality of image sensor arrays extending in the main scanning direction. When the image signals photoelectrically converted from each image sensor array are connected at a predetermined connection position, a position detection pattern indicating a position corresponding to the connection position is formed linearly in the sub-scanning direction. A position-detecting member that extends in the sub-scanning direction on the image reading means side than a light source that irradiates light on the document, and a joint-position detecting light source that irradiates the position detecting member with light The image overlap area of the connection position portion of the two image sensor arrays in which the reflected light of the light emitted from the connection position detection light source is connected based on the position detection pattern of the position detection member The reflecting member reflected from the light source, the light source for irradiating the document with the light source, and the reduction optical means are moved in the sub-scanning direction to reduce the reflected light of the light irradiated to the document from the light source. The image is introduced into each image sensor array by optical means to read the image of the original, and the position detection member is irradiated from the splicing position detection light source and reflected by the folded reflection member, and each image is reflected by the reduction optical means. The image connection position of each image sensor array is corrected from the image signal of the position detection pattern introduced into the sensor array.

  ADVANTAGE OF THE INVENTION According to this invention, the shift | offset | difference of the image of the connection position part of a some image sensor can be correct | amended more accurately.

1 is a schematic front view of a main part of an image reading apparatus to which an embodiment of the present invention is applied. The principal part side schematic block diagram of an image reading apparatus. The principal part schematic perspective view of an image reading apparatus. The perspective view of a position detection pattern member periphery at the time of using a fluorescent lamp light source. The top view of a position detection pattern member. 1 is a block configuration diagram of an image reading apparatus. The flowchart which shows an initial state measurement process. The figure which shows an example of the joint pixel measurement original for initialization. 5 is a flowchart showing image correction processing. Explanatory drawing of dpi conversion. The figure which shows an example of an interpolation coefficient table. Explanatory drawing of the reading position correction | amendment after dpi conversion. The top view of a position detection pattern member in case there is only one position detection line. The principal part front schematic block diagram of the image reading apparatus which shows the arrangement configuration of the position detection pattern member at the time of forming only one position detection line. FIG. 3 is a schematic front view of a main part of a folding mirror provided with a light shielding unit and an image reading apparatus. The block diagram which inclined the folding mirror with respect to the position detection half member. The top view of the position detection pattern member which detects a position also about a subscanning direction. The figure which shows an example of an ideal subscanning position and actual position shift when a subscanning position detection line is 45 degree | times with respect to a subscanning direction. Explanatory drawing of the correction | amendment process in the case of match | combining the deviation | shift of one CCD with the other CCD. Explanatory drawing of the correction process in the case of match | combining the deviation | shift amount of all CCD to an ideal detection position. Explanatory drawing of the correction process of a subscanning position shift. The top view of the position detection member in which the subscanning detection line is formed in the subscanning direction at predetermined intervals. FIG. 6 is a plan view of a position detection pattern member in which sub-scanning detection lines are formed at a predetermined interval in the main scanning position detection line and the sub-scanning direction. The top view of the position detection pattern member in which the sub scanning position detection line is formed asymmetrically with respect to the main scanning position detection line. 1 is a schematic front view of an image forming apparatus.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 25 are diagrams showing an embodiment of an image reading apparatus, an image forming apparatus, an image reading method, and an image reading program of the present invention. FIG. 1 shows an image reading apparatus, an image forming apparatus, 1 is a schematic front view of a main part of an image reading apparatus 1 to which an embodiment of an image reading method and an image reading program is applied.

  1, in the image reading apparatus 1, two image reading units (image reading means) 3a and 3b are arranged in the main scanning direction (left and right direction in FIG. 1) below a contact glass 2 on which a document G is placed. A position detection pattern member (position detection member) 4 and a folding mirror (folding reflection member) 5 are disposed between the two image reading units 3a and 3b. As shown in FIGS. 1 to 3, each of the image reading units 3a and 3b includes CCDs (Charge Coupled Devices) 11a and 11b which are image sensor arrays, lenses 12a and 12b constituting a reduction optical means, a first mirror 13a, 13b, second mirrors 14a and 14b, third mirrors 15a and 15b, and the like. Although not shown, the image reading units 3a and 3b are mounted on a carriage (running body) that can move over a predetermined length in the sub-scanning direction.

  As shown in FIG. 3, the light source 6 may be a single omnidirectional light source such as a fluorescent lamp over the entire main scanning direction, or a document disposed for each of the image reading units 3a and 3b. A light source using an LED (Light Emitting Diode) having directivity in the G direction may be used.

  When the light source 6 is a single omnidirectional light source, for example, in the case of a fluorescent light source, the light source 6 is generally connected to a bracket (light source direction setting means) 7 as shown in FIG. The bracket 7 holds the light source 6 and condenses the light emitted from the light source 6 in the direction of the original G. The light of the light source 6 is passed through the bracket 7 to the position detection pattern member 4 disposed on the side opposite to the original G, and the position detection pattern member 4 is irradiated with light from the light source 6 as detection light source light. A slit (detection light passage portion) 8 is formed. The slit 8 is formed so as to irradiate only the position detection pattern member 4 with the radiated light of the light source 6, and is, for example, a slit having a predetermined length in the sub-scanning direction. The detection light passage part for irradiating the position detection pattern member 4 with the light from the light source 6 is not limited to the slit 8. For example, an elongated transparent member that transmits the light of the plateau 6 to the position detection pattern member 4. It may be. The light source 6 is not limited to a non-directional light source that radiates uniformly around a fluorescent lamp or the like, and is a light source such as an LED (Light Emitting Diode) having a predetermined direction (directivity). Also good. In the case of a light source having such directivity, a light source (connection position detection light source) that emits a detection light source light that irradiates the position detection pattern member 4, for example, an LED dedicated to connection position detection is used for reading a document. It is necessary to provide other than the light source 6.

  As shown in FIG. 5, the position detection pattern member 4 is provided with two position detection lines 4 a in a state of extending in the sub-scanning direction, having a predetermined thickness and a predetermined interval, The two position detection lines 4a are thread-like lines such as thin wires when reading at a resolution of 600 dpi (Dots Per Inch) and are parallel lines with an accuracy of 0.02 mm (1/2 pixel) or less. . That is, when the CCD 11a of the image reading unit 3a and the CCD 11b of the image reading unit 3b are brought into focus on the original surface, an image obtained by photoelectrically converting the image of the position detection line 4a of the position detection pattern member 4 by the CCD 11a and the CCD 11b The image of the position of the pixel + α on the line 4a, that is, the surface of the position detection pattern member 4 is read at a position slightly shifted as shown in FIG. Therefore, it is necessary to read different positions of the position detection pattern member 4 for each of the image reading units 3a and 3b, and the two position detection lines 4a are formed on the position detection pattern member 4 in a state in accordance with the reading position. ing.

  As shown in FIGS. 1 and 2, the image reading apparatus 1 reflects the light irradiated to the original G from the light source 6 by the original G, and the first mirrors 13a, 13b, second of the image reading units 3a, 3b. The light is condensed on the CCDs 11a and 11b through the mirrors 14a and 14b, the third mirrors 15a and 15b, and the lenses 12a and 12b, and the CCDs 11a and 11b photoelectrically convert the incident light.

  At this time, as shown in FIG. 1, the CCD 11a of the image reading unit 3a and the CCD 11b of the image reading unit 3b are overlapped with each other at the central portion in the main scanning direction of the original G (hereinafter simply referred to as an image overlapping portion). Therefore, the image reading apparatus 1 connects the image read by the CCD 11a and the image read by the CCD 11b by using the predetermined position of the overlapped portion of the images as a connecting position. The image is as if it was read by a CCD.

  The image reading device 1 has a function of correcting the joining position of images when the CCD 11a and the CCD 11b read the original G. Specifically, the joint pixel position and position detection when the CCD 11a and the CCD 11b read the joint pixel measurement original Ga for initial setting (see FIG. 8) in a state where the carriages on which the CCD 11a and the CCD 11b are mounted are stopped. The initial position detection line pixel position (initial pattern pixel position) obtained by reading the position detection line 4a of the pattern member 4 is stored in the nonvolatile memory. When the image reading apparatus 1 moves the carriage to read the image of the document G, the image reading device 1 reads the position detection line 4a of the position detection pattern member 4 together with the reading of the document G, and reads the position detection line 4a. Based on the connection pixel position and the initial position detection line pixel position of the non-volatile memory, the image connection position is corrected. Such a variation requiring correction of the joining position is caused by the movement of the image reading units 3a and 3b in the sub-scanning direction and the like, and the first mirrors 13a and 13b are bent.

  As shown in FIG. 6, the image reading apparatus 1 includes a control unit 21, a timing signal generation circuit 22, the CCDs 11 a and 11 b, analog processing / A / D conversion circuits 23 a and 23 b, a sub-scanning delay circuit 24, and main scanning. Reading position determination circuit 25, main scanning DPI conversion circuit 26, main scanning connecting circuit 27, image processing circuit 28, carriage position sensor 29, document size sensor 30, pressure plate open / close sensor 31, operation display unit 32, motor driver 33, carriage drive A motor 34 and the light source 6 are provided.

  The control unit 21 is an EEPROM (Electrically Erasable and EEPROM) that retains stored contents even when the power of the CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and the image forming apparatus 1 is turned off. Programmable ROM), a non-volatile memory such as a hard disk, and the like. In the ROM, the basic program as the image processing apparatus 1, the connection position of the read images of the CCD 11a and the CCD 11b, and the peripheral pixels are corrected. A correction processing program and necessary data are stored in advance.

  The system control unit 21 controls the operation of each unit of the image reading device 1 while executing the basic operation as the image reading device 1 while the CPU uses the RAM as a work memory based on the program in the ROM. The read image correction process of the present invention is performed to correct the connection position of the read images of the CCD 11a and the CCD 11b and the peripheral image.

  That is, the image reading apparatus 1 includes a ROM, an EEPROM (Electrically Erasable and Programmable Read Only Memory), an EPROM, a flash memory, a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a CD-RW (Compact Disc Rewritable), a DVD. An image reading program for executing the image reading method of the present invention recorded on a computer-readable recording medium such as a (Digital Versatile Disk), an SD (Secure Digital) card, or an MO (Magneto-Optical Disc) is read into the ROM. And an image reading apparatus configured to execute an image reading method that performs high-quality image correction processing by correcting a change in a joint position and a surrounding image caused by movement of a carriage, which will be described later. This image reading program is a computer-executable program written in a legacy programming language such as assembler, C, C ++, C #, Java (registered trademark) or an object-oriented programming language, and is stored in the recording medium. Can be distributed.

  The timing signal generation circuit 22 outputs predetermined timing signals to the CCDs 11 a and 11 b, the analog processing / A / D conversion circuits 23 a and 23 b, and the sub-scanning delay circuit 24 under the control of the control unit 21.

  The CCD 11a and the CCD 11b photoelectrically convert the reflected light from the original G in synchronization with the timing signal from the timing signal generation circuit 22 and output analog image signals to the analog processing / A / D conversion circuits 23a and 23b. .

  The analog processing / A / D conversion circuits 23 a and 23 b perform necessary signal processing on the analog image signal based on the timing signal from the timing signal generation circuit 22, and then perform digital conversion to the sub-scanning delay circuit 24. The sub-scanning delay circuit 24 has a line buffer for each of the image reading units 3 a and 3 b, and is controlled by the control unit 21 and based on the timing signal from the timing signal generation circuit 22. 3b, the amount of sub-scanning deviation between 3b and the process of matching the main scanning dpi conversion line are performed.

  The main scanning reading position determination circuit 25 specifies the pixel position (position detection line pixel position) PG of the position detection line 4a from the reading pixels of the position detection line 4a of the position detection pattern member 4, and actually outputs the pixels of the CCD 11a and the CCD 11b. The positional deviation of the joint pixel TG that is the pixel of the joint is calculated, and positional deviation information is passed to the main scanning DPI conversion circuit 26.

  The main scanning DPI conversion circuit (main scanning dpi conversion circuit) 26 has a line buffer for each of the image reading units 3a and 3b, and determines pixels (image information) from the sub-scanning delay circuit 24 for the corresponding line and main scanning reading position. Based on the positional deviation information of the joint pixel TG from the circuit 25, the dpi conversion is performed between the correction start pixel controlled by the control unit 21 and the joint pixel and output to the main scanning joint circuit 27.

  The main scanning connecting circuit (joining means) 27 rearranges the image data from the main scanning DPI conversion circuit 26 into one line data based on the positional deviation information, and passes the image data to the image processing circuit 28.

  The image processing circuit 28 performs necessary image processing on the image data for one line connected by the main scanning connecting circuit 27 and outputs the image data to a subsequent circuit.

  The carriage position sensor 29 is a reflective or transmissive optical sensor or the like, and is a sub-carriage of the carriage on which the CCDs 11a and 11b, mirrors 13a, 13b to 15a and 15b, lenses 12a and 12b, the folding mirror 5, the light source 6, and the like are mounted. The position in the scanning direction is detected, and the detection result is output to the control unit 21.

  The document size sensor 30 detects the size of the document G set on the contact glass 2 and outputs the detection result to the control unit 21.

  The pressure plate opening / closing sensor 31 detects opening / closing of a pressure plate (not shown) that covers the upper surface of the contact glass 2 on which the document G to be read is placed, and outputs the detection result to the control unit 21.

  The operation display unit 32 includes various keys necessary for operating the copying apparatus 1, and includes a display (for example, a liquid crystal display) and a lamp such as an LED. The operation display unit 32 performs various operations necessary for various processes such as a document reading process using the image reading apparatus 1 and various operations in a reading correction process as described later from the operation keys. The contents of the command input from, and various information notified from the image reading apparatus 1 to the operator are displayed.

  The motor driver 33 is connected to the carriage drive motor 34 and drives the carriage drive motor 34 under the control of the control unit 21 to sub-scan the carriage on which the image reading units 3a and 3b, the folding mirror 5 and the light source 6 are mounted. Move in the direction at a predetermined speed. The motor driver 33 and the carriage drive motor 34 function as scanning drive means as a whole.

  Next, the operation of this embodiment will be described. The image reading apparatus 1 according to the present embodiment corrects the image shift at the joint portion of the CCDs 11a and 11b, which are a plurality of image sensor arrays, with higher accuracy.

  That is, the image reading apparatus 1 irradiates the original G set on the contact glass 2 from the light source 6 with the reading light from the light source 6 mounted on the carriage moved in the sub-scanning direction, and is reflected by the original G. The reflected light of the read light is sequentially reflected by the first mirrors 13a and 13b, the second mirrors 14a and 14b, and the third mirrors 14a and 14b of the image reading unit 3a and the image reading unit 3b, and the lenses 12a and 12b. The light is condensed on the respective CCDs 11a and 11b, and analog image signals photoelectrically converted by the CCDs 11a and 11b are output to the analog processing / A / D conversion circuits 23a and 23b. The image reading device 1 finally combines the digital image data obtained by photoelectric conversion of the CCD 11a and the CCD 11b at a predetermined connection position by the main scanning connection circuit 27 to obtain image data as read by one CCD.

  Incidentally, when the carriage moves in the sub-scanning direction in the image reading apparatus 1, vibrations are generated in the mirrors 13a, 13b, 14a, 14b, 15a, and 15b of the image reading unit 3a and the image reading unit 3b as the carriage moves. . Due to this vibration, the position of the image on the original G that enters the CCD 11a and the CCD 11b through the lenses 12a and 12 fluctuates in the main scanning direction. Since such fluctuations occur, image degradation occurs when the main scanning connecting circuit 27 connects the image data of the CCD 11a and the image data of the CCD 11b at a preset connecting position.

  In view of this, the image reading apparatus 1 according to the present embodiment has two position detection lines 4a extending between the image reading unit 3a and the image reading unit 3b in the sub-scanning direction of the connecting positions of the images of the CCD 11a and the CCD 11b. The applied position detection pattern member 4 is disposed so as to extend in the sub-scanning direction, and the position detection line 4a of the position detection member 4 is detected by the CCD 11a and the CCD 11b while the carriage before reading the original G is stationary. Is detected, and a joint position line La of the joint pixel measurement original document Ga for initial setting is detected and stored as a pixel position of the joint position line La in a nonvolatile memory or the like of the control unit 21, and the carriage is When the original G is moved and read, the position detection line 4a of the position detection member 4 is detected in real time and stored in the nonvolatile memory. Based on the difference between the pixel position of the joint position lines La which are performing the splice point correction and image correction of an image read by the CCD11a and CCD11b with.

  Then, as shown in FIG. 7, the image reading apparatus 1 first performs an initial state measurement process for acquiring and storing the joint position and the pixels of the CCDs 11 a and 11 b that read the joint position before reading the document G. Do.

  That is, as shown in FIG. 7, the image reading apparatus 1 sets the initial setting joint pixel measurement original Ga as shown in FIG. 8 on the contact glass 2 before reading the original G, and the control unit 21. However, the drive of the carriage drive motor 34 is started via the motor driver 33, and the drive is controlled to the low speed control state (step S101). As shown in FIG. 8, the initial setting joint pixel measurement original (reference original) Ga is obtained from the abutting end position of the initial setting joint pixel measuring original Ga on the contact glass 2 in the sub-scanning direction. Are drawn at intervals of 10 mm, and 0.5 mm wide lines are drawn at intervals of 5 mm. In the main scanning direction, the front and back of the abutting end and the joint position line La are spaced by 5 mm, and the others are spaced by 10 mm. A line having a width of 5 mm is drawn, and a position of 210 mm from the end surface in the main scanning direction is a joint position, and a line of 1 mm width is described as a joint position line La at the joint position.

  The control unit 21 monitors the signal from the carriage position sensor 29 to check whether the output of the carriage position sensor 29 has changed, for example, whether it has changed from an H (high) state to an L (low) state (step S102).

  If the output of the carriage position sensor 29 does not change in step S102, the control unit 21 determines that there is an abnormality in the carriage drive system such as the carriage drive motor 34, and turns off the drive of the carriage drive motor 34 (OFF). Then, an error message indicating that an abnormality has occurred is displayed on the display of the operation display unit 32, and the process is terminated (step S103).

  In step S102, when the output of the carriage position sensor 29 changes (for example, changes from H to L), the control unit 21 determines that the carriage is moving and detects the position of the joint in advance. In order to move the pattern member 4 to the initial state measurement position, the position counter A that counts the ON / OFF change of the carriage position sensor 29 is started. Then, when the count value of the position counter A reaches the count number n indicating the initial state measurement position, the control unit 21 stops driving the carriage drive motor 34 (step S104).

  When the movement of the carriage is stopped, the control unit 21 detects the joint position line La of the joint pixel measurement document Ga for initial setting by the CCD 11a and the CCD 11b of the image reading unit 3a and the image reading unit 3b and the position of the position detection pattern member 4. From the reading result of the detection line 4a, the pixel positions of the CCD 11a and the CCD 11b that read the joint position line La are acquired as the joint position TG, and the pixels of the CCD 11a and the CCD 11b that detect the position detection line 4a (hereinafter, position measurement pixels). The PG0 is measured (step S105), the joint position pixel TG0 and the position measurement pixel PG0 in the initial state are stored in the nonvolatile memory, and the initial setting state measurement process is terminated (step S106).

  Next, when reading a normal document G, the image reading apparatus 1 reads an image of the document G, reads the position detection line 4a of the position detection pattern member 4, and measures the position when the position detection line 4a is read. Based on the pixel PG1 and the position measurement pixel PG0 in the initial state stored in the nonvolatile memory and the joint position pixel TG0, the joint position pixel TG1 at the time of actual reading when the document G is read is obtained in the initial state. The amount of variation from the joint position pixel TG0 is obtained, and the read image of the original G is corrected.

  That is, in the image reading apparatus 1, as shown in FIG. 9, when the document G to be read is set on the contact glass 2 and the start key is operated, the control unit 21 drives the carriage via the motor driver 33. The motor 34 is driven in the low-speed drive control state to start the low-speed movement of the carriage in the sub-scanning direction (step S201), the signal from the carriage position sensor 29 is monitored, and the output of the carriage position sensor 29 changes. It is checked whether the H (high) state has changed to the L (low) state (step S202).

  If the output of the carriage position sensor 29 does not change in step S202, the control unit 21 determines that there is an abnormality in the carriage drive system such as the carriage drive motor 34, and turns off the drive of the carriage drive motor 34 (OFF). Then, an error display indicating that an abnormality has occurred is displayed on the display of the operation display unit 32, and the process is terminated (step S203).

  In step S202, when the output of the carriage position sensor 29 changes (for example, changes from H to L), the control unit 21 determines that the carriage is moving, and the CCDs 11a and 11b of the image reading units 3a and 3b. The position measurement pixel PG1 at the time of actual reading obtained by reading the position detection line 4a of the position detection pattern member 4 is measured for each line, and the joint position pixel TG1 at the time of actual reading is calculated using the following equation (1) ( Step S204).

  In Equation (1), the signs of + and-are determined by the signs of (PG1-PG0).

  When the controller (initial setting means) 21 calculates the joint position pixel TG1 at the time of actual reading, the position correction of the image of the original G read by the CCD 11a and the CCD 11b of each of the image reading units 3a and 3b is dpi converted for each pixel. This completes the image correction process (step S205).

  The control unit 21 causes the main scanning DPI conversion circuit 26 to perform this dpi conversion processing. That is, the main scanning DPI conversion circuit 26 determines that four pixels adjacent in the main scanning direction of the image data are X (i), X (i + 1), X (i + 2), X ( When i + 3), seven interpolation pixels are generated between each pixel X (i), X (i + 1), X (i + 2), and X (i + 3) from the four reference pixels.

  At this time, the main scanning DPI conversion circuit 26 calculates the interpolated pixel value σ (r) by the following equation (2), which is a well-known equation, using the interpolation coefficient h. The interpolation coefficient h is generated by a cubic function convolution method.

σ (n) = (X (i) × h (1 + r) + X (i + 1) × h (r) + X (i + 2)
Xh (1-r) + X (i + 3) * h (2-r))
/ (H (1 + r) + h (r) + h (1-r) + h (2-r)) (2)
The image data including the base pixel from which the document G is read and the interpolation pixel generated by the equation (2) is eight times the base image data amount. Then, the main scanning DPI conversion circuit 26 refers to scaling control data different from the scaling ratio, selects a pixel to be output, and generates output data. The storage coefficient h is given by parameters n and r from the interpolation coefficient table Tb1 shown in FIG.

  When the above-described dpi conversion is performed, the image reading device 1 corrects the reading position of the image data of the original G read by the CCD 11a and the image data of the original G read by the CCD 11b by the main scanning connecting circuit 27, and reads the CCD 11a. The obtained image data and the image data read by the CCD 11b are joined.

  In this case, as shown in FIG. 12, the main scanning connecting circuit 27 has a case where the number of main scanning misaligned pixels before correction changes according to the reading position with respect to the center of the optical axis (the center pixel of the light source is 0%). (When 100% position is the joint pixel) When the correction start position is set to 30% position, 36% position, 45% position, 55% position, etc., the amount of deviation after correction Therefore, in consideration of the required image quality and the like, the correction start position is appropriately set to correct the joining position.

  That is, in FIG. 12, when the correction start position is 30% and 36% by correcting the shift to TG1 at the joint pixel position with respect to the optical axis center, the main scanning shift pixel is on the negative side. Is finally corrected to the position of the joint position TG0. However, if the correction start position is 45% or 55%, the joint scan position TG0 is finally obtained with the main scanning deviation amount being positive. The corrected state is shown in FIG. Accordingly, by correcting the joints by the CCDs 11a and 11b, the joint G can be read at the same pixel position with respect to the original G.

  The image reading apparatus 1 performs necessary image processing on the image data connected by the main scanning connecting circuit 27 by the image processing circuit 28 and then outputs the processed image data to a subsequent circuit.

  In the above description, as the position detection line 4a of the position detection pattern member 4, two position detection lines 4a are formed corresponding to the CCD 11a and the CCD 11b, respectively. This is for accurately detecting the position detection line 4a when the position of the upper surface of the position detection pattern member 4 is adjusted to the focus position of the CCD 11a and the CCD 11b. From the viewpoint of detecting the position, the position detection line 4a Is not limited to two. For example, one position detection line 4a may be formed on the position detection pattern member 4 as shown in FIG. In this case, as shown in FIG. 14, the position detection pattern member 4 on which one position detection line 4a is formed is shifted from the focus positions of the CCD 11a and the CCD 11b.

  In this way, the component accuracy can be relaxed according to the image accuracy required for the image reading apparatus 1, and the cost can be reduced.

  Further, as shown in FIG. 15, the image reading apparatus 1 may be provided with a folding mirror portion 50 in which a light shielding member 51 is attached to a folding mirror (folding reflecting member) 5. That is, as shown in FIG. 15A, the region portion of the portion where the light (stray light) from the outside other than the light from the position detection line 4a portion of the position detection pattern member 4 enters the folding mirror 5, that is, FIG. As shown in FIG. 15B, the light-reflecting members 51 may be provided at both end portions and the central portion of the folding mirror 5 so as to prevent the stray light from entering.

  This prevents stray light from entering the folding mirror 5 of the folding mirror unit 50 that reflects light from the position detection line 4a of the position detection pattern member 4 to the image reading unit 3a and the image reading unit 3b. The detection accuracy of the position detection line 4a can be improved, and the positional deviation correction accuracy of the joint position can be improved.

  Further, as shown in FIG. 16A, the image reading apparatus 1 may be arranged with the folding mirror 5 inclined at a predetermined angle with respect to the position detection pattern member 4. In this case, as shown in FIG. 16B, the folding mirror 5 is preferably set so that the angle of the reading optical axis of the position detection pattern member 4 and the light source 6 is 25 degrees or more with respect to the position detection pattern member 4. It is.

  If it does in this way, the influence of the regular reflection component from the light source 6 with respect to the position detection pattern member 4 can be prevented, and the detection accuracy of the position detection line 4a on the position detection pattern member 4 can be improved.

  In the above description, the case of detecting and correcting the image shift at the joint position portion of the CCDs 11a and 11b as image sensors in the main scanning direction has been described. However, the image shift at the joint position portion also in the sub-scanning direction. May be detected and corrected.

  In this case, for example, a position detection pattern member 40 as shown in FIG. 17 is used. As shown in FIG. 17, the position detection pattern member 40 includes a main scanning position detection line 40 a and a main scanning position for detecting an image shift in the main scanning direction extending in the sub-scanning direction similar to the position detection pattern member 4. Two sub-scanning position detection lines 40b having a predetermined angle (for example, the same thickness as the main scanning position detection line 40a) in a state inclined at a predetermined angle, for example, 45 degrees with respect to the detection line 40a, are applied. The two sub-scanning position detection lines 40b are provided in a state where the middle of the two main scanning position detection lines 40a is an intersection.

  In the image reading apparatus 1, the main scanning connecting circuit 27 moves the carriage in the sub scanning direction by the carriage driving motor 34, and the reflected light of the light irradiated from the light source 6 to the original G is mounted on the carriage. The image of the original G is read by introducing it into the CCD 11a and CCD 11b by optical means, and irradiated to the position detection pattern member 40 from the splicing position detection light source 6 and reflected by the folding mirror 5, and is applied to the CCD 11a and CCD 11b by the reduction optical means. The joining position of the CCD 11a and CCD 11b images is corrected from the image of the introduced main scanning position detection line 40a, and the sub-scanning correction position where the sub-scanning position detection line 40b of FIG. The position detection pattern member 40 is irradiated from the splicing position detection light source 6 at the position shown in FIG. Correcting the splice point of the reflected CCD11a from the image of the introduced sub-scanning position detection line 40b in CCD11a and CCD11b in reducing optical means and CCD11b image (sub-scanning direction of the connecting position).

  In this case, since the sub-scanning position detection line 40b is provided at an angle of 45 degrees with respect to the main-scanning position detection line 40a, the main-scanning connection circuit 27 has the sub-scanning position detection line 40b and the main-scanning position detection line 40a. This difference can be used as the sub-scanning position as it is.

  That is, when the sub-scanning position detection line 40b has an inclination angle of 45 degrees with respect to the sub-scanning direction, for example, as shown in FIG. 18, with respect to the ideal positions of the CCDs 11a and 11b, Therefore, the main scanning connecting circuit 27 can correct the connecting position (connecting position in the sub-scanning direction) of the images of the CCD 11a and the CCD 11b based on this position shift. In this case, since the movement amount of the CCDs 11a and 11b is expressed as the movement amount of the main scanning position, the ideal detection position is the movement amount = observation distance, but the observation distance which is the actual movement amount of the CCDs 11a and 11b. The difference from the ideal detection position is expressed as a deviation amount.

  Then, the main scanning connecting circuit 27 calculates a deviation amount that is a difference between the observation distance and the ideal detection position for each of the CCDs 11a and 11b, and matches the deviation amount of one of the CCDs 11a and 11b. For example, as shown in FIG. 19, the shift amount of the CCD 11b is corrected so as to match the shift amount of the CCD 11a, and the joining position is corrected. The main scanning connecting circuit 27 calculates a deviation amount, which is a difference between the observation distance and the ideal detection position, for each CCD 11a, 11b, and sets the deviation amounts of the CCDs 11a, 11b to the ideal detection positions. For example, as shown in FIG. 20, the shift amount of the CCD 11a and the CCD 11b is corrected so as to match the ideal detection position, and the connecting position is corrected.

  Specifically, the main scanning connecting circuit 27 corrects the shift amount by moving the pixels in the sub scanning direction as shown in FIG. For example, the main scanning connecting circuit 27 includes a line buffer necessary for correction, and the shift amount to be corrected is a movement value of adjacent pixels of the CCD 11a and the CCD 11b. Then, as shown in FIG. 21, the main scanning connecting circuit 27 compares the correction LINE with the correction LINE-1 and provides a restriction that the correction LINE cannot be moved by 1 LINE or more. Is embedded, the movement destination where the overlapping pixel is generated may cause the processing of the correction LINE-1 and the lack of the pixel. In either case, the data of the target correction LINE is embedded or the average value is embedded. . In this case, the correction start pixel can be arbitrarily determined.

  Further, the position detection pattern member 40 is not limited to one in which only one set of symmetrical lines is formed with respect to the main scanning position detection line 40a as shown in FIG. 17, for example, as shown in FIG. As described above, the sub-scanning position detection lines 40b that are inclined at a predetermined angle similar to that shown in FIG. 17, for example, 45 degrees, are formed over the entire sub-scanning direction at a predetermined interval with respect to the two main scanning position detection lines 40a. Alternatively, as shown in FIG. 23, the sub-scanning position detection lines 40b inclined at a predetermined angle, for example, 45 degrees, with respect to one main scanning line position detection line 40a are spaced by a predetermined interval in the sub-scanning direction. It may be formed throughout. Further, as shown in FIG. 24, the position detection pattern member 40 is formed with asymmetrical sub-scanning position detection lines 40b with respect to a predetermined number (in FIG. 24, one) main scanning position detection lines 40a. Also good.

  As described above, the image reading apparatus 1 according to the present embodiment includes each of the image reading unit (image reading unit) 3a and the image reading unit 3b having a plurality of CCDs (image sensor arrays) 11a and CCDs 11b extending in the main scanning direction. The CCD 11a and the CCD 11b receive the reflected light of the light irradiated from the light source 6 to the original G by a reduction optical means including the first mirrors 13a and 13b, the second mirrors 14a and 14b, the third mirrors 15a and 15b, and the lenses 12a and 12b. When the image signals photoelectrically converted by the CCDs 11a and 11b are joined at a predetermined joining position, a position detection line (position detection pattern) 4a indicating a position corresponding to the joining position is provided in the sub-scanning direction. The original G is irradiated with light by a position detection pattern member (position detection member) 4 formed in a straight line. A light source (joining position detection light source) 6 that is arranged to extend in the sub-scanning direction from the light source 6 to the image reading unit 3a and the image reading unit 3b side, and irradiates the position detection pattern member 4 with light; The reflected light of the light emitted from the light source 6 to the position detection pattern member 4 is reflected to an image overlapping region having a predetermined width across the connection position of the two CCDs 11a and 11b connected based on the position detection line 4a of the position detection pattern member 4. A carriage (running body) on which a folding mirror (folding reflecting member) 5 to be lighted, a light source 6 that irradiates light to the original G, and a reduction optical means is moved in the sub-scanning direction by a carriage drive motor 34, and the light source 6 The reflected light of the light radiated from the document G to the document G is introduced into the CCD 11a and the CCD 11b by the reduction optical means to read the image of the document G. The image of each CCD 11a and CCD 11b is imaged from the image of the position detection line 4a irradiated to the position detection pattern member 4 from the connection position detection light source 6, reflected by the folding mirror 5, and introduced into the CCD 11a and CCD 11b by the reduction optical means. The connection position is corrected by the main scanning connection circuit 27.

  Therefore, even when the original G is actually read, the position detection line 4a of the position detection pattern member 4 is read, and the images of the CCD 11a and the CCD 11b are connected by the vibration of the mirrors 13a, 13b to 15a, 15b of the reduction optical means. It is possible to detect a change in position and a change in image reading position, and it is possible to improve the image quality by accurately correcting the connecting position of the images of the CCD 11a and the CCD 11b and the read image.

  Further, the image reading apparatus 1 of the present embodiment has the CCD 11a of the image reading unit (image reading means) 3a in which a plurality of CCDs (image sensor arrays) 11a and 11b are arranged extending in the main scanning direction. 11b, photoelectrically converting incident light into an image signal, and at least an image reading process step for reading an image of the document G with a predetermined region sandwiching the connecting position in the main scanning direction as an image overlapping region; A position detection line (position detection pattern) 4a indicating a position corresponding to the connecting position is provided in the sub-scanning direction so as to extend in the sub-scanning direction from the light source 6 that irradiates the reading light to the image reading unit 3a side. The reflected light of the light emitted from a predetermined light source (connection position detection light source) 6 is folded onto the linearly formed position detection pattern member (position detection member) 4. The return mirror (folding reflection member) 5 reflects the reflected image to the image overlapping area of the two CCDs 11a and 11b to which the images are connected based on the position detection line 4a of the position detection pattern member 4; A light source 6 for irradiating light, a reduction optical means for reducing reflected light from the original G and introducing it into the CCDs 11a and 11b, a carriage (running body) on which the connection position detecting light source 6 and the folding mirror 5 are mounted. The CCD 11a, 11b of the image reading unit 3a reflects the reflected light and position from the document G in the sub-scanning driving process step for moving in the sub-scanning direction and the image reading processing step while moving the carriage in the sub-scanning driving process step. The reflected light of the detection pattern member 4 is photoelectrically converted into an image signal, and based on the image signal of the position detection pattern member 4 To correct the serial splice point, we are running the stitching process step joining the image signal of the original G in 該繋 skill position after correction, an image reading method with.

  Therefore, even when the original G is actually read, the position detection line 4a of the position detection pattern member 4 is read, and the images of the CCD 11a and the CCD 11b are connected by the vibration of the mirrors 13a, 13b to 15a, 15b of the reduction optical means. It is possible to detect a change in position and a change in image reading position, and it is possible to improve the image quality by accurately correcting the connecting position of the images of the CCD 11a and the CCD 11b and the read image.

  Furthermore, the image reading apparatus 1 according to the present embodiment includes an image reading unit (image reading unit) 3a in which a plurality of CCDs (image sensor arrays) 11a and 11b are arranged in the main scanning direction. Each CCD 11a, 11b photoelectrically converts incident light into an image signal, and reads an image of the document G in duplicate with at least a predetermined region sandwiching the connecting position in the main scanning direction as an image overlap region, A position detection line (position detection pattern) 4a that is arranged to extend in the sub-scanning direction from the light source 6 that irradiates the reading light to G in the image reading unit 3a side and indicates a position corresponding to the connecting position is sub-scanned. Reflection of light irradiated from a predetermined light source (connection position detection light source) 6 to a position detection pattern member (position detection member) 4 formed linearly in the direction A folding reflection process in which light is reflected by the folding mirror (folding reflection member) 5 to the image overlapping area of the two CCDs 11a and 11b to which the images are connected based on the position detection line 4a of the position detection pattern member 4; A carriage (running body) on which a light source 6 for irradiating light to G, a reduction optical means for reducing reflected light from the original G and introducing it to the CCDs 11a and 11b, the splicing position detection light source 6 and the folding mirror 5 are mounted. ) In the sub-scanning direction, and the CCD 11a, 11b of the image reading unit 3a detects the reflected light and position from the original G by moving the carriage in the sub-scanning driving process and moving the carriage. The reflected light of the pattern member 4 is photoelectrically converted into an image signal, and the joining position is corrected based on the image signal of the position detection pattern member 4 It is equipped with image reading program for executing a joining process of joining the image signal of the original G in 該繋 skill position after correction.

  Therefore, even when the original G is actually read, the position detection line 4a of the position detection pattern member 4 is read, and the images of the CCD 11a and the CCD 11b are connected by the vibration of the mirrors 13a, 13b to 15a, 15b of the reduction optical means. It is possible to detect a change in position and a change in image reading position, and it is possible to improve the image quality by accurately correcting the connecting position of the images of the CCD 11a and the CCD 11b and the read image.

  Further, in the image reading apparatus 1 of the present embodiment, the image setting unit 3a, 3b has an initial setting joint where a joint position line La, which is a joint line indicating at least the joint position of the images of the CCDs 11a, 11b, is described. The pixel measurement document (reference document) Ga is a joint pixel position TG0 which is the pixel position where the CCD 11a, 11b has read the joint position line La while the carriage is stopped, and the position detection pattern member 4 position detection line. The position measurement pixel position (initial pattern pixel position) PG0 obtained by reading 4a is stored in the nonvolatile memory by the control unit (initial setting means) 21, and the position detection pattern member 4 is read by the main scanning connecting circuit 27 when reading the document. Position of the CCD 11a, 11b when the position detection line 4a is read at the time of actual reading (pattern pixel position at the time of document reading) TG1 and joint pixel position TG0 and position measurement pixel position of the non-volatile memory (initial pattern pixel position) on the basis of PG0, is corrected joint position.

  Therefore, it is possible to more accurately measure the variation in the joining position between when the carriage is stopped and when the carriage is moving, and more accurately determine the joining position of the images of the CCD 11a and the CCD 11b and the read image. Correction can improve the image quality.

  Furthermore, in the image reading apparatus 1 of the present embodiment, the light source 6 is a line-shaped omnidirectional light source that extends in the main scanning direction and irradiates light on the original G. Is provided with a bracket (light source direction setting means) 7 for irradiating only the light to the bracket 7 and a slit (for irradiating the position detection pattern member 4 with a part of the light irradiated to the bracket 7 from the light source 6 is passed through the bracket 7. Detection light passage part) 8 is formed.

  Therefore, the reading of the original G and the detection of the position detection line 4a can be performed by using one light source 6, and the connecting position of the images of the CCD 11a and the CCD 11b and the read image are accurately corrected at low cost. Can be improved.

  In the image reading apparatus 1 of the present embodiment, the light source 6 may be a light source such as an LED having directivity for irradiating light in the direction of the document G. In this case, as the connection position detection light source, A separate light source for irradiating only the position detection pattern member 4 is provided.

  In this way, the image processing apparatus 1 can be reduced in size and power consumption, and the image quality can be improved by accurately correcting the connecting position of the images of the CCD 11a and the CCD 11b and the read image at low cost. it can.

  Further, in the image reading apparatus 1 of the present embodiment, the position detection pattern member 4 is provided with position detection lines 4a corresponding to the CCDs 11a and 11b, and the folding mirror 5 detects the position of the position detection pattern member 4. The line 4a and the position of the original G have the same optical path length, and the reflected light of the position detection line 4a is focused on the invalid areas of the CCDs 11a and 11b corresponding to the position detection line 4a. It is arranged at the position where it enters.

  Therefore, the position detection line 4a of the position detection pattern member 4 can be accurately detected by the CCDs 11a and 11b, and the connecting position can be accurately corrected.

  Further, in the image reading apparatus 1 of this embodiment, one position detection line 4a is formed on the position detection pattern member 4, and the folding mirror 5 is a position where the position detection line 4a and the document G are connected. Are arranged at the position where they match.

  Therefore, the component accuracy can be relaxed according to the image accuracy required for the image reading apparatus 1, and the connection position can be corrected at a low cost and appropriately.

  Further, in the image reading apparatus 1 of the present embodiment, the light-reflecting member 51 is applied to a portion other than the predetermined region including the region where the reflection mirror 5 reflects the reflected light from the position detection line 4a of the position detection pattern member 4. Yes.

  Accordingly, the stray light is prevented from entering the folding mirror 5 of the folding mirror unit 50 that reflects the light from the position detection line 4a of the position detection pattern member 4 to the image reading unit 3a and the image reading unit 3b. The detection accuracy of 4a can be improved, and the positional deviation correction accuracy of the joint position can be improved.

  Further, in the image reading apparatus 1 of the present embodiment, the folding mirror 5 is connected to the optical axis of the reflected light of the position detection pattern member 4 and the optical axis of the light source 6 that is a light source for position detection is shifted by a predetermined angle. It is arranged in a state.

  Therefore, the influence of the regular reflection component from the light source 6 on the position detection pattern member 4 can be prevented, and the detection accuracy of the position detection line 4a on the position detection pattern member 4 can be improved.

  Further, in the image reading apparatus 1 of the present embodiment, the position detection pattern member 40 is formed with sub-scanning position detection lines (sub-scanning position detection patterns) 40b indicating the sub-scanning positions of the CCDs (image sensor arrays) 11a and 11b. The main scanning connecting circuit (joining means) 27 photoelectrically converts the reflected light from the original G and the reflected light from the sub-scanning position detection line 40b into image signals by the CCDs 11a and 11b. The sub-scanning position of the splicing position is corrected based on the image signal of the scanning position detection line 40b, and the image signal of the original G is spliced at the corrected splicing position.

  Therefore, even when the original G is actually read, the main scanning position detection line 40a and the sub scanning position detection line 40b of the position detection pattern member 40 are read, and the mirrors 13a, 13b to 15a, 15b of the reduction optical means are read. It is possible to detect fluctuations in the joining position and image reading position in the main scanning direction and the sub-scanning direction of the images of the CCD 11a and the CCD 11b due to vibration, and the joining positions in the main scanning direction and the sub-scanning direction of the images of the CCD 11a and the CCD 11b. The read image can be accurately corrected to further improve the image quality.

  Further, in the image reading apparatus 1 of the present embodiment, the sub-scanning position detection lines 40b of the position detection pattern member 40 are provided in a line pattern inclined at a predetermined angle with respect to the main scanning position detection lines 40a.

  Therefore, the difference between the sub-scanning position detection line 40b and the main scanning position detection line 40a can be used as it is as the sub-scanning position, and the processing can be simplified.

  Furthermore, in the image reading apparatus 1 of the present embodiment, the sub-scanning position detection lines 40b of the position detection pattern member 40 are formed at predetermined intervals over the entire region of the position detection pattern member 40 in the sub-scanning direction.

  Therefore, it is possible to detect the sub-scanning deviation between the CCDs 11a and 11b for each line and the like, and partially between the CCDs 11a and 11b in accordance with the deviation of the CCDs 11a and 11b based on the difference in deviation amount between the CCDs 11a and 11b. Can be corrected.

  Further, in the image reading apparatus 1 of this embodiment, the main scanning position detection line (joining means) 40a detects any positional deviation in the sub-scanning direction of each CCD (image sensor array) 11a, 11b. The sub-scanning position of the joint position is adjusted to match the sub-scanning position or the preset reference sub-scanning position.

  Therefore, it is possible to easily and accurately correct the connection position and the read image in the main scanning direction and the sub-scanning direction of the images of the CCD 11a and the CCD 11b, thereby further improving the image quality.

  In the above-described embodiments, the case where the present invention is applied to the image reading apparatus 1 has been described. However, the present invention can be similarly applied to an image forming apparatus equipped with such an image reading apparatus 1.

  That is, the image reading apparatus 1 is mounted on, for example, an image forming apparatus 100 as shown in FIG. 25. The image forming apparatus 100 includes a paper feeding unit 102, a transport unit 103, and an image forming unit in a main body housing 101. 104, a fixing unit 105, a paper discharge unit 106, an image reading unit 107, and the like are housed, and a manual feed tray 110, a document table 111, a paper discharge tray 112, an operation unit (not shown), and the like are further provided. The image forming apparatus 100 supports wide paper.

  A plurality of sheets P are set in the sheet feeding unit 102, and the conveyance unit 103 includes registration rollers 121 and the like, adjusts the timing of appropriate sheets P in the sheet feeding unit 102 with the registration rollers 121, and then forms an image forming unit. Transport to 104. The transport unit 103 also transports the paper P set on the manual feed tray 110 to the image forming unit 104 after adjusting the timing by the registration rollers 121.

  The image forming unit 104 includes a charging unit, an optical writing unit, a developing unit, a transfer unit, a cleaning unit, and the like around a photosensitive member 122 that is driven to rotate counterclockwise in FIG. The body 122 is uniformly charged (for example, charged to -1200V). In the image forming unit 104, the light writing unit 123 irradiates the photoconductor 122 uniformly charged by the charging unit with light whose lighting is controlled based on the image data of the document read by the image reading unit 107. The electrostatic charge image is formed by eliminating the charge on the surface of the photosensitive member 122 where the light is irradiated, and the developing unit attaches toner to the photosensitive member 122 on which the electrostatic latent image is formed. Form. The image forming unit 104 transfers the toner image formed on the photosensitive member 122 to the paper P conveyed from the paper feeding unit 102 by the transfer unit, and separates the transferred paper P by the separation charger to fix the toner image. Transport to 105. In addition, the image forming unit 104 cleans the residual toner on the photosensitive member 122 that has been transferred by the cleaning unit, discharges the cleaned photosensitive member 122 by the discharging unit, and then uniformly charges the charging unit by the charging unit. Then, it is again used for image formation.

  In the image forming apparatus 100, the paper P on which an image is formed by the image forming unit 104 and fixed by the fixing unit 105 is discharged to the paper discharge tray 112 by the paper discharge unit 106.

  In the image forming apparatus 100, the image reading apparatus 1 is applied as the image reading unit 107. The image reading unit 107 sends the originals on the document table 111 one by one to the image reading unit 107 to read the images. After the image of the stationary document is read by the unit 107, the image is discharged onto the paper discharge tray 113. The image reading unit 107 uses the CCDs 11a and 11b in the original reading operation, and corrects the image shift accompanying the movement of the CCDs 11a and 11b as described above.

  Accordingly, the image forming apparatus 100 improves the image quality of the read image when the image forming unit 104 forms an image of the original read by the image reading unit 107 and transfers the image to the computer or the like, thereby improving the output image. Image quality can be improved.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

DESCRIPTION OF SYMBOLS 1 Image reading apparatus 2 Contact glass 3a, 3b Image reading unit 4 Position detection pattern member 4a Position detection line 5 Folding mirror 6 Light source 7 Bracket 8 Slit 11a, 11b CCD
12a, 12b Lenses 13a, 13b First mirror 14a, 14b Second mirror 15a, 15b Third mirror 21 Control unit 22 Timing signal generation circuit 23a, 23b Analog processing / A / D conversion circuit 24 Sub-scanning delay circuit 25 Main scanning reading Position determination circuit 26 Main scanning DPI conversion circuit 27 Main scanning connection circuit 28 Image processing circuit 29 Carriage position sensor 30 Document size sensor 31 Pressure plate open / close sensor 32 Operation display section 33 Motor driver 34 Carriage drive motor 50 Folding mirror section 51 Light shielding member G Document Ga Initial setting seam pixel measurement original La Seam position line 100 Image forming apparatus 101 Main body housing 102 Paper feed unit 103 Conveying unit 104 Image forming unit 105 Fixing unit 106 Paper discharge unit 107 Image reading unit 110 Manual feed tray 111 Document table 112 Paper discharge tray 113 Paper discharge tray 121 Registration roller 122 Photoconductor 123 Optical writing unit

JP 2005-86406 A

Claims (15)

A plurality of image sensor arrays are arranged extending in the main scanning direction. Each image sensor array photoelectrically converts incident light into an image signal, and at least a predetermined area sandwiching a connecting position in the main scanning direction. An image reading means having an image overlap area for reading an image in duplicate;
A position detection pattern that is arranged to extend in the sub-scanning direction from the light source that irradiates the reading light to the document in the sub-scanning direction is formed linearly in the sub-scanning direction. A position detecting member,
Reflected light of the light radiated to the position detection member from a predetermined connection position detection light source is applied to the image overlap area of the two image sensor arrays to which the images are connected based on the position detection pattern of the position detection member. A folded reflection member for reflection;
The light source for irradiating the original with light, the reduction optical means for reducing the reflected light from the original and introducing it into the image sensor arrays, the traveling body on which the connection position detection light source and the folding reflection member are mounted;
Sub-scanning driving means for moving the traveling body in the sub-scanning direction;
Each image sensor array of the image reading means photoelectrically converts the reflected light from the document and the reflected light of the position detection pattern into an image signal while moving the traveling body by the sub-scanning driving means, and detects the position. A splicing means for correcting the splicing position based on a pattern image signal and splicing the original image signal at the spliced position after correction;
An image reading apparatus comprising: The image reading device includes:
Pixels in which the image sensor array has read the connecting lines in a state where the traveling body has stopped the reference document on which the connecting lines indicating the connecting positions of the images of the image sensor array are described. Initial setting means for storing in a nonvolatile memory the connecting pixel position that is a position and the initial pattern pixel position that is the pixel position obtained by reading the position detection pattern of the position detection member;
The splicing means is
Correcting the joint position based on the pattern pixel position at the time of document reading of the image sensor array that has read the position detection pattern, the joint pixel position of the nonvolatile memory, and the initial pattern pixel position when the document is read; The image reading apparatus according to claim 1. The image reading device includes:
The light source is a line-shaped omnidirectional light source that extends in the main scanning direction and irradiates the original with light,
Comprising light source direction setting means for irradiating light of the light source only in the direction of the document,
The light source direction setting means includes
A detection light passage portion is formed that transmits or passes a part of the light emitted from the light source to the light source direction setting means and irradiates the position detection member as the connection position detection light source. The image reading apparatus according to claim 1. The light source is
A light source having directivity for irradiating light toward the document,
The connection position detection light source is:
The image reading apparatus according to claim 1, wherein the image reading apparatus is a light source that emits light only to the position detection member. The position detection member is
The position detection pattern corresponding to each image sensor array is formed,
The folded reflection member is
The position detection pattern of the position detection member and the position of the document have the same optical path length, and the reflected light of the position detection pattern is used as the invalid area of the image sensor array corresponding to the position detection pattern. 4. The image reading apparatus according to claim 1, wherein the image reading apparatus is disposed at a position where the light is incident in a focused state. The position detection member is
One position detection pattern is formed,
The folded reflection member is
4. The image reading apparatus according to claim 1, wherein the position detection pattern and the position to be the connection position of the originals are arranged at positions on the image sensor array. 5. . The folded reflection member is
6. The image reading apparatus according to claim 1, wherein a light shielding material is applied to a portion other than a predetermined region including a region that reflects reflected light from the position detection pattern. The folded reflection member is
7. The optical system according to claim 1, wherein the optical axis of the splicing position detecting light source is shifted by a predetermined angle with respect to the optical axis of the reflected light of the position detecting member. An image reading apparatus according to claim 1. The position detection member is
A sub-scanning position detection pattern indicating a sub-scanning position of each image sensor array is formed,
The splicing means is
Each image sensor array photoelectrically converts the reflected light from the document and the reflected light of the sub-scanning position detection pattern into an image signal, and the sub-scanning position of the splicing position based on the image signal of the sub-scanning position detection pattern 9. The image reading apparatus according to claim 1, wherein the image signals of the originals are joined at the joint position after the correction. The sub-scanning position detection pattern is
The image reading apparatus according to claim 9, wherein the image reading apparatus is a line pattern inclined at a predetermined angle with respect to the position detection pattern. The sub-scanning position detection pattern is
The image reading apparatus according to claim 9, wherein the position detection member is formed at a predetermined interval over the entire region in the sub-scanning direction. The splicing means is
A sub-scanning position correction of the splicing position is performed to match a positional deviation in the sub-scanning direction of each image sensor array to any one of the sub-scanning positions of the image sensor array or a preset reference sub-scanning position. The image reading apparatus according to any one of claims 9 to 11. An image forming apparatus including an image reading device,
An image forming apparatus comprising the image reading apparatus according to claim 1 as the image reading apparatus. In each image sensor array of the image reading means extending in the main scanning direction and provided with a plurality of image sensor arrays, the incident light is photoelectrically converted into an image signal, and at least the connecting position is sandwiched in the main scanning direction. An image reading processing step for reading the document image in duplicate with the predetermined area as the image overlapping area;
A position detection pattern that is arranged to extend in the sub-scanning direction from the light source that irradiates the reading light to the document in the sub-scanning direction is formed linearly in the sub-scanning direction. Two image sensor arrays in which reflected light of light emitted from a predetermined connection position detection light source is turned to a position detection member, and an image is connected based on the position detection pattern of the position detection member by a folded reflection member A folding reflection processing step of reflecting the image overlapping region of
Sub-scanning the light source for irradiating the original with light, the reduction optical means for reducing the reflected light from the original and introducing it into the image sensor arrays, the traveling position detection light source and the folding reflection member. A sub-scanning drive processing step for moving in the direction;
In the image reading processing step, the image sensor array of the image reading means converts the reflected light from the original and the reflected light of the position detection pattern into an image signal while moving the traveling body in the sub-scanning driving processing step. A splicing step for photoelectrically converting and correcting the splicing position based on the image signal of the position detection pattern, and splicing the image signals of the originals at the spliced position after correction;
An image reading method characterized by comprising: On the computer,
In each image sensor array of the image reading means extending in the main scanning direction and provided with a plurality of image sensor arrays, the incident light is photoelectrically converted into an image signal, and at least the connecting position is sandwiched in the main scanning direction. An image reading processing step for reading the document image in duplicate with the predetermined area as the image overlapping area;
A position detection pattern that is arranged to extend in the sub-scanning direction from the light source that irradiates the reading light to the document in the sub-scanning direction is formed linearly in the sub-scanning direction. Two image sensor arrays in which reflected light of light emitted from a predetermined connection position detection light source is turned to a position detection member, and an image is connected based on the position detection pattern of the position detection member by a folded reflection member A folding reflection processing step of reflecting the image overlapping region of
Sub-scanning the light source for irradiating the original with light, the reduction optical means for reducing the reflected light from the original and introducing it into the image sensor arrays, the traveling position detection light source and the folding reflection member. A sub-scanning drive processing step for moving in the direction;
In the image reading processing step, the image sensor array of the image reading means converts the reflected light from the original and the reflected light of the position detection pattern into an image signal while moving the traveling body in the sub-scanning driving processing step. A splicing step for photoelectrically converting and correcting the splicing position based on the image signal of the position detection pattern, and splicing the image signals of the originals at the spliced position after correction;
An image reading program characterized in that the program is executed.

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