JP2007328010A - Image forming apparatus and image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image reader capable of clear reading an image including the vicinity of the binding part of a book and preventing image data at the center part of an image from being missed even when reading a leaf of image. <P>SOLUTION: An original platen 20 has: a first plane part 26 and a second plane part 28 formed in mountain shape as their cross-sectional shape in a second direction X so that the center part 23 may be higher than both ends 24 and 25, and inclined in a reverse direction to each other; and a cylindrical part 27 having a first radius R1 in the center part 23. The first plane part 26, the cylindrical part 27 and the second plane part 28 are integrally formed without a joint. A guide rail 41 has: a first line part 41d and a second line part 41f formed in mountain shape in the second direction so that the center part 41a may be higher than both ends 41b and 41c, and inclined in a reverse direction to each other; and a circular-arc shaped part 41e having a second radius R2 in the center part. The first line part 41d, the circular-arc shaped part 41e and the second line part 41f are integrally formed without a joint. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that reads image data from a document or book placed on a platen and an image forming apparatus including the image reading apparatus.

  When reading or copying an image printed on a book, the vicinity of the binding portion of the book is lifted off the platen, and the image is distorted, unclear, or black streaks appear along the binding portion. It is known. Therefore, in order to clearly read an image printed on a book in a conventional copying machine or the like, for example, as shown in Patent Document 1, various cross sections in the sub-scanning direction of the document table are used. Have been devised. Thus, according to the mountain-shaped document table, the vicinity of the binding portion of the book is likely to be in close contact with the document table, so that the possibility that the image near the binding portion is distorted or unclear is reduced, and the image quality of the copy is reduced. Will improve.

  In Patent Document 2, two flat glass plates are joined to form a two-sided platen so that the cross section of the mirror moving direction (sub-scanning direction) has a mountain shape, and two sets of mirrors are formed. A mirror scan type copying machine is shown in which a unit is moved in parallel along the left and right surfaces of a document table, images printed on both pages in a state where a book is opened, and copied on a recording sheet. However, two sets of mirror units for image reading are required, the structure of the apparatus becomes complicated, the apparatus becomes larger, and the cost increases. Further, since the image at the top of the mountain-shaped document table cannot be read, when copying a one-leaf image, a white streak is formed at the center of the copy, and the image at that portion is lost.

On the other hand, in Patent Document 3, a two-sided document platen is formed by joining two flat glass plates so that the cross section in the sub-scanning direction is a mountain shape, and a CIS (Contact Image Sensor) is used as the platen. An image reading apparatus that performs parallel reading along with the image reading is shown. In the vicinity of the top of the mountain-shaped original table, the CIS is moved so as to draw an arc. Therefore, when the CIS is moved at a constant speed, the read image is compressed in the sub-scanning direction. For this reason, in the image reading apparatus of Patent Document 3, it is necessary to perform processing for correcting distortion on the read image data, and the image data processing becomes complicated. Further, since the CIS is separated from the document table at the top of the mountain-shaped document table, when the top image of the mountain-shaped document table cannot be read and an image of a single leaf is read, the image at the center of the image is displayed. Data is missing.
Japanese Utility Model Publication No. 4-94859 JP 2000-242137 A Japanese Patent Laid-Open No. 5-37742

  The present invention has been made in order to solve the above-described problems of the conventional example, and can clearly read an image including the vicinity of the binding portion of a book, and can also read an image at the center of the image even when reading a single leaf image. An object of the present invention is to provide an image reading apparatus in which no data is lost and image data processing is not required for image data in the vicinity of the binding portion.

In order to achieve the above object, the invention according to claim 1 is formed of a light-transmitting material, and is arranged in a first direction on a document table on which an original sheet or an open book is placed. The microlens array, an image sensor in which pixels are arranged at the focal position of each microlens, and a strip-shaped illumination light having a predetermined width in each of a first direction and a second direction orthogonal to the first direction. And a CIS (Contact Image Sensor) moved in the second direction while being in close contact with the inner surface of the document table, and a constant distance from the inner surface of the document table. A guide rail provided on the CIS, CIS driving means for moving the CIS in the second direction along the guide rail, and converting an analog signal output from the image sensor into image data composed of a digital signal. A / D Conversion means, image data processing means for performing predetermined processing on the A / D converted image data, image data storage means for storing the image data subjected to the predetermined processing, and image subjected to the predetermined processing In an image forming apparatus including an image forming unit that forms an image on recording paper using data,
The document table is formed in a mountain shape so that the cross-sectional shape in the second direction is higher than the both end portions in the second direction, and gradually from the first end portion toward the central portion in the second direction. A first flat portion formed to be higher, a cylindrical portion formed at the central portion and having a predetermined first radius R1, and gradually lowered from the central portion toward the second end portion. The second flat portion is formed, and the first flat portion, the cylindrical portion, and the second flat portion are integrally formed without a seam so as to have the same uniform thickness. ,
The guide rail is formed in a mountain shape so that the central portion is higher than both ends in the second direction, and gradually increases from the first end toward the central portion in the second direction. A first linear portion formed, an arc-shaped portion having a predetermined second radius R2 formed in the central portion, and a first linear portion formed so as to be gradually lowered from the central portion toward the second end portion. It has two straight portions, and the first straight portion, the arc-shaped portion, and the second straight portion are integrally formed with no seam so as to have the same uniform distance with respect to the inner surface of the document table. Has been
The CIS driving means moves the CIS at the first speed V1 in the first straight portion and the second straight portion of the guide rail, and moves the CIS at the second speed V2 (V2 = V1 × R2) in the arcuate portion. / R1),
As a result, an image including the vicinity of the binding portion of the book can be read clearly, and an image of a single leaf can be read without losing the image data in the center of the image. In contrast, the image data processing by the image data processing means is unnecessary.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect of the present invention, the image forming apparatus further comprises document discrimination means for discriminating whether the document placed on the document table is a one-leaf document or a book, and placed on the document table. When the printed document is a book, when the CIS passes a predetermined range near the top of the arcuate portion of the guide rail, the CIS is not scanned at night or is scanned by the CIS. The image data is discarded.

According to a third aspect of the present invention, there is provided a document table on which a single-leaf document or an open book is placed, a CIS (Contact Image Sensor) moved in a predetermined direction while being in close contact with the inner surface of the document table, An image reading apparatus comprising: a guide rail provided to maintain a constant distance with respect to the inner surface of the document table; and a CIS driving unit that moves the CIS in the predetermined direction along the guide rail.
The document table is formed in a mountain shape so that a cross-sectional shape thereof in the predetermined direction is higher than both ends, and a first plane part and a second plane part inclined in opposite directions to each other, and the center A cylindrical portion having a predetermined radius in the portion, and the first plane portion, the cylindrical portion and the second plane portion are integrally formed seamlessly,
The guide rail is formed in a mountain shape so that a central portion is higher than both end portions in the predetermined direction, and a first linear portion and a second linear portion that are inclined in opposite directions, and a predetermined portion in the central portion. An arc-shaped portion having a radius is provided, and the first linear portion, the arc-shaped portion, and the second linear portion are integrally formed without a seam.

  According to a fourth aspect of the present invention, in the image reading apparatus according to the third aspect, the CIS driving means moves the CIS at a first speed in a first linear portion and a second linear portion of the guide rail, and The CIS is moved at a second speed slower than the first speed in the arcuate portion so that the image reading speed on the outer surface of the document table is constant.

  According to a fifth aspect of the present invention, in the image reading apparatus according to the third or fourth aspect of the present invention, the image reading apparatus further includes original determination means for determining whether the original placed on the original table is a one-leaf original or a book, When the document placed on the book is a book, when the CIS passes through a predetermined range near the top of the arcuate portion of the guide rail, the CIS does not read an image, or The image data read by the CIS is discarded.

  According to the first aspect of the present invention, the document table is formed in a mountain shape so that the cross-sectional shape in the second direction is higher than the both ends, so that the image printed on the book is read. Even in this case, as in the conventional example, the vicinity of the binding portion of the book is easily brought into close contact with the document table, and the image in the vicinity of the binding portion is not distorted or unclear. In addition, since the document table is integrally formed without a seam so that the first flat surface portion, the cylindrical portion, and the second flat surface portion have the same uniform thickness, the flat plate as in the conventional example is used. Unlike an original platen that has two pieces of glass joined together, there is no seam in the center. The guide rail is integrally formed without a seam such that the first straight portion, the arc-shaped portion, and the second straight portion have the same uniform distance with respect to the inner surface of the document table, respectively. Since the CIS is moved in the second direction along the guide rail while being in close contact with the inner surface of the document table, image data in the center of the image is not lost even when reading a single leaf image. Therefore, even if an image is formed using the image data obtained by A / D converting the analog signal output from the CIS as it is, there is no white line in the center of the copy, and a clear image is obtained. can get. Further, the CIS is moved at the first speed V1 in the first straight portion and the second straight portion of the guide rail, and is moved at the second speed V2 (V2 = V1 × R2 / R1) in the arcuate portion. The image reading speed on the outer surface of the document table is constant. Therefore, even if an image is formed using the image data obtained by A / D converting the analog signal output from the CIS as it is, the image is not distorted, and the image data is also applied to the image data near the binding portion. Image data processing by the processing means becomes unnecessary, and even when an image is formed on recording paper using the image data, there is no distortion at the center of the image and a clear image can be obtained.

  According to the invention of claim 2, when the document is a book, the image in the vicinity of the top portion of the document table is not read or is discarded after being read, so that the center of the image formed on the recording paper is There is no black streak in the area, and a clear image can be obtained.

  According to the invention of claim 3, the document table is formed in a mountain shape so that the cross-sectional shape in the second direction is higher than the both ends, so that the image printed on the book is read. Even in this case, as in the conventional example, the vicinity of the binding portion of the book is easily brought into close contact with the document table, and the image in the vicinity of the binding portion is not distorted or unclear. In addition, since the document table is integrally formed without a seam so that the first flat surface portion, the cylindrical portion, and the second flat surface portion have the same uniform thickness, the flat plate as in the conventional example is used. Unlike an original platen that has two pieces of glass joined together, there is no seam in the center. The guide rail is integrally formed without a seam such that the first straight portion, the arc-shaped portion, and the second straight portion have the same uniform distance with respect to the inner surface of the document table, respectively. Since the CIS is moved in the second direction along the guide rail while being in close contact with the inner surface of the document table, image data in the center of the image is not lost even when reading a single leaf image.

  According to the invention of claim 4, the CIS is moved at the first speed in the first linear portion and the second linear portion of the guide rail, and is moved at the second speed slower than the first speed in the arcuate portion. The image reading speed on the outer surface of the document table is constant. Therefore, even if an image is formed using the image data obtained by A / D converting the analog signal output from the CIS as it is, the image is not distorted, and the image data is also applied to the image data near the binding portion. Image data processing by the processing means becomes unnecessary, and even when an image is formed on recording paper using the image data or an image is reproduced on a monitor screen, there is no distortion at the center of the image and a clear image can be obtained.

  According to the invention of claim 5, when the document is a book, the image in the vicinity of the top part of the document table is not read or discarded after being read. Even when an image is formed on paper or reproduced on a monitor screen, a black line does not appear in the center of the obtained image, and a clear image can be obtained.

  An image reading apparatus and an image forming apparatus using the same according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of an image forming apparatus 1 having a so-called all-in-one function having a scanner function, a printer function, and a copier function as an example of an image forming apparatus according to the present invention. As shown in FIG. 1, the image forming apparatus 1 is provided with an image reading unit (image forming apparatus) 10 having a scanner function at the upper part thereof, and an image forming unit such as an ink jet printer is formed below the image reading part 10. A section (image forming means) 50 is provided.

  The image forming unit 50 includes a rail 52 held horizontally by the frame 51, a carriage 53 that is driven to reciprocate on the rail 52, an ink cartridge 54 mounted on the carriage 53, and a carriage 53 that reciprocates along the rail 52. A carriage driving mechanism 55 including a driving belt 55a, a pulley 55b, a motor 55c, and the like, a paper feeding roller 56a for transporting the recording paper P from a paper feeding cassette or a paper feeding tray (not shown) in a direction perpendicular to the paper surface, The paper feeding mechanism 56 includes a motor 56b for driving the paper roller 56a and a driving force transmission mechanism 56c such as a gear train or a belt and a pulley. In a printer in which the carriage 53 is driven to reciprocate like an ink jet printer, the reciprocating direction of the carriage is referred to as a main scanning direction, and the conveyance direction of the recording paper P is referred to as a sub-scanning direction. The image forming unit 50 drives the paper feeding mechanism 56 to convey the recording paper P at a predetermined speed in the sub-scanning direction, and reciprocates the carriage 53 in the main scanning direction, thereby connecting an externally connected personal computer, digital camera, image, and the like. The ink droplets are ejected toward the recording paper P using the image data read by the forming unit 10 to form an image on the recording paper P.

  The image reading unit 10 is in contact with the document table 20 fitted in the rectangular opening 12 provided in the upper part of the housing 11 and the inner surface 21 of the document table 20, and the longitudinal direction (second direction) X of the document table 20. A CIS (Contact Image Sensor) 30 that is moved in the direction of C, and a CIS drive mechanism (CIS drive means) 40 that reciprocates the CIS 30 in the second direction.

  The document table 20 is formed of a light-transmitting material such as glass, for example, and a single-sheet document or an open book can be placed on the outer surface 22 thereof. The document table 20 is formed in a mountain shape so that the cross-sectional shape in the second direction is higher at the central portion 23 than at both end portions 24 and 25, and from the first end portion 24 to the central portion 23 in the second direction. A first flat portion 26 formed so as to gradually become higher, a cylindrical portion 27 having a predetermined first radius R1 formed in the vicinity of the central portion 23, and a second end portion 25 from the central portion 23. It has the 2nd plane part 28 formed so that it may become low gradually toward. The first flat portion 26, the cylindrical portion 27, and the second flat portion 28 are integrally formed without a seam so as to have the same uniform thickness.

  The CIS 30 includes a microlens array arranged in a short direction of the document table (a direction perpendicular to the paper surface: a first direction), an imaging element in which pixels are arranged at a focal position of each microlens, a first direction and a second direction. There is an illumination device (illuminating means) that irradiates a strip-shaped illumination light having a predetermined width in the direction along the microlens array (it is not shown because it is publicly known).

  The CIS drive mechanism 40 includes a guide rail 41 provided so as to maintain a certain distance from the inner surface 21 of the document table 20, and a belt 42 for moving the CIS 20 in the second direction along the guide rail 41. It comprises a pulley 43, a motor 44 and the like. The guide rail 41 is formed in a mountain shape so that the central portion 41a is higher than both end portions 41b and 41c in the second direction, and gradually gradually from the first end portion 41b toward the central portion 41a in the second direction. A first linear portion 41d formed to be higher, and an arc shape formed in the vicinity of the central portion 41a and having a predetermined second radius R2 that is the same as the center of the first radius R1 of the outer surface 22 of the document table 20. It has a portion 41e and a second straight portion 41f formed so as to be gradually lowered from the central portion 41a toward the second end portion 41c. The first straight portion 41d, the arc-shaped portion 41e, and the second straight portion 41f are integrally formed with no joint so as to have the same uniform distance from the inner surface 21 of the document table 20, respectively.

  The image reading unit 10 further includes a control unit 60 including an A / D conversion circuit (A / D conversion means) that converts an analog signal output from the image sensor of the CIS 30 into image data composed of a digital signal. . The control unit 60 includes a CPU, a ROM, a RAM, and the like in addition to the A / D conversion circuit, and an image data processing unit (image data processing unit) that performs predetermined processing on the A / D converted image data. The image data storage unit (image data storage unit) that stores the image data subjected to the above processing, the CIS drive unit (CIS drive unit) that controls the start and stop of the motor 44 of the CIS drive mechanism 40, the rotation direction, the rotation speed, and the like. ).

  A load sensor 61 such as a strain gauge is provided in a portion of the inner surface 21 of the document table 20 that does not affect image reading. These load sensors 61 are connected to a control unit 60 that also functions as a document determination unit (document determination unit), and a document placed on the outer surface 22 of the document table 20 is one leaf according to the output of the load sensor 61. Whether it is a manuscript or a book based on its weight.

  A plurality of position sensors 62 a to 62 d are provided along the guide rail 41, and each position sensor 62 a to 62 d is connected to the control unit 60. In FIG. 1, when the CIS 30 moves from the first end 41b side to the second end 41c side of the guide rail 41, it is assumed that an image of a document or book placed on the document table 20 is read. While the CIS drive circuit determines that the CIS 30 is currently in the first linear portion 41d of the guide rail 41, the CIS drive circuit drives the motor 44 to move the CIS 30 at the first speed V1. On the other hand, when it is determined that the CIS 30 has reached the boundary B1 (see FIG. 2) between the first linear portion 41d and the arc-shaped portion 41e, the voltage or pulse width supplied to the motor 44 is changed, and the moving speed of the CIS 30 is changed to the first speed. Switch to the second speed V2, which is slower than the first speed. Then, while it is determined that the CIS 30 is currently in the arcuate portion 41e of the guide rail 41, the CIS 30 is moved at the second speed V2.

  Here, the relationship between the first speed V1 and the second speed V2 will be examined with reference to FIG. Assuming that a single-sheet document is placed on the outer surface 22 of the document table 20 and reading an image while scanning the document in the second direction, the image reading range by the CIS 30 on the outer surface 22 of the document table 20 If the movement speed is constant, even if the image data read by the CIS 30 is used without correction as it is to form an image, the obtained image is not distorted in the second direction. However, when the CIS 30 is moved at a constant speed in the entire section of the guide rail 41, when the CIS 30 passes through the arc-shaped portion 41e of the guide rail 41, the corresponding CIS 30 is formed on the outer surface 22 of the cylindrical portion 27 of the document table 20. The moving speed of the image reading range is increased according to the ratio of the first radius R1 of the cylindrical portion 27 to the second radius R2 of the arc-shaped portion 41e of the guide rail 41. Therefore, when an image is formed using the image data read by the CIS 30 without correction as it is, a portion corresponding to the cylindrical portion 27 in the obtained image is compressed and distorted in the second direction. Therefore, the CIS drive circuit of the control unit 60 is configured such that when the CIS 30 is in the arcuate portion 41e of the guide rail 41, the moving speed of the CIS 30 is set to the cylindrical portion 27 with respect to the second radius R2 of the arcuate portion 41e of the guide rail 41. Inversely proportional to the ratio of the first radius R1, the delay is made so that V2 = V1 × R2 / R1. As a result, the image reading speed on the outer surface 22 of the document table 20 becomes constant, and even if an image is formed using the image data obtained by A / D converting the analog signal output from the CIS 30 as it is, The image data processing by the image data processing circuit is not necessary for the image data in the vicinity of the binding portion, and even if an image is formed on the recording paper using the image data, the image data is not distorted in the central portion of the image. And a clear image can be obtained.

  Next, an image reading operation by the image reading unit 10 will be described. In general, most single-sheet manuscripts are written on thin paper such as copy paper, report paper, and tracing paper. In addition, even thick paper is at most about photographic paper. Therefore, the weight of one leaf manuscript is very light. On the other hand, books vary from a relatively thin magazine to an encyclopedia, but are much heavier than a single-leaf manuscript. Therefore, if the output of the load sensor 61 is monitored, it can be determined whether the document placed on the document table 20 is a one-leaf document or a book.

  When an image reading signal is input from an externally connected personal computer or an image reading switch (not shown) provided in the image forming apparatus, the control unit 60 functions as a document discrimination unit, and the load sensor 61 is turned on. It is determined from the weight of the original detected using the original whether the original placed on the outer surface 22 of the original table 20 is a one-leaf original or a book. Next, the control unit 60 functions as a CIS driving unit and confirms that the CIS 30 is at the first end 41b of the guide rail 41 by a position sensor 62a provided in the vicinity of the first end 41b of the guide rail 41. After that, the motor of the CIS drive mechanism 40 is driven to move the CIS 30 along the first linear portion 41d of the guide rail 41 at the first speed V1. Meanwhile, image reading by the CIS 30 is continued.

  When it is confirmed by the position sensor 62b provided at the boundary portion B1 between the first linear portion 41d and the arc-shaped portion 41e of the guide rail 41 that the CIS 30 has reached the boundary portion B1 between the first linear portion 41d and the arc-shaped portion 41e. The control unit 60 switches the moving speed of the CIS 30 to the second speed V2 that is slower than the first speed by changing the voltage supplied to the motor 44, the pulse width, and the like. When the document placed on the outer surface 22 of the document table 20 is a single-sheet document, image reading by the CIS 30 is continued as it is. On the other hand, when the document placed on the outer surface 22 of the document table 20 is a book, the image is not read by the CIS 30 in the predetermined range near the top 23 of the document table 20, or the read image data Discard. Accordingly, when the original is a one-leaf original, the image data in the center of the original is not lost, and the image data obtained by A / D converting the analog signal output from the CIS 30 is used as it is. Even if formed, there is no white streak in the center of the formed image, that is, the copy, and a clear image can be obtained. In the case where the document is a book, the image image is not read or the image data is discarded with respect to the vicinity of the binding portion of the book, in which a black streak has been reflected in the center of the obtained image, so that the obtained image is discarded. Even when an image is formed using data, a black streak does not appear in the center of the obtained image, and a clear image can be obtained.

  Further, the position sensor 62c provided at the boundary portion B2 (see FIG. 2) between the arc-shaped portion 41e and the second straight portion 41f of the guide rail 41 causes the CIS 30 to have a boundary between the arc-shaped portion 41e and the second straight portion 41f. Upon confirming that the part B2 has been reached, the controller 60 changes the voltage, pulse width, etc. supplied to the motor 44 and switches the moving speed of the CIS 30 to the first speed. Then, the position sensor 62d provided in the vicinity of the second end portion 41c of the guide rail 41 drives the motor of the CIS drive mechanism 40 until it is confirmed that the CIS 30 has reached the second end portion 41c of the guide rail 41. Then, the CIS 30 is moved at the first speed V1 along the second linear portion 41f of the guide rail 41. Meanwhile, image reading by the CIS 30 is continued.

  As described above, according to the image forming apparatus of the present invention, the cross-sectional shape of the document table 20 in the second direction is formed in a mountain shape so that the central portion 23 is higher than both end portions 24 and 25. Therefore, even when reading an image printed on a book, as in the conventional example, the vicinity of the binding portion of the book is easily adhered to the document table, and the image near the binding portion is not distorted or unclear. .

  Further, since the document table 20 is integrally formed with no seam so that the first flat portion 26, the cylindrical portion 27, and the second flat portion 28 have the same uniform thickness, the conventional example is shown. Unlike the document table in which two flat glass plates are joined together, there is no seam in the center. The guide rail 41 is integrated seamlessly so that the first linear portion 41d, the arc-shaped portion 41e, and the second linear portion 41f have the same uniform distance from the inner surface 21 of the document table 20, respectively. Since the CIS 30 is formed and is moved in the second direction along the guide rail 41 while being in close contact with the inner surface 21 of the document table 20, the image data in the center of the image is lost even when reading a single leaf image. There is nothing. Therefore, even if an image is formed using the image data obtained by A / D converting the analog signal output from the CIS 30 as it is, there is no white stripe in the center of the copy, and a clear image is obtained. can get.

  Further, the CIS 30 is moved at the first speed V1 in the first straight portion 41d and the second straight portion 41f of the guide rail 41, and at the second speed V2 (V2 = V1 × R2 / R1) in the arc-shaped portion 41e. Since it is moved, the image reading speed on the outer surface 22 of the document table 20 becomes constant. Therefore, even if an image is formed using the image data obtained by A / D converting the analog signal output from the CIS 30 as it is, the image is not distorted, and the image data is also applied to the image data near the binding portion. Image data processing by the processing means becomes unnecessary, and even when an image is formed on recording paper using the image data, there is no distortion at the center of the image and a clear image can be obtained.

  Further, when the document is a book, the image in the vicinity of the top 23 of the document table 20 is not read, or is discarded after being read. Therefore, a black streak is formed at the center of the image formed on the recording paper. A clear image can be obtained without being reflected.

  In addition, this invention is not limited to the structure of the said embodiment, A various deformation | transformation is possible. For example, although an ink jet printer is exemplified as the image forming unit 50, other image forming methods such as a laser printer and a thermal printer can be used. The present invention is not limited to the image forming apparatus, and may be an image reading apparatus having only an image reading function.

  That is, an image reading apparatus according to the present invention includes a CIS (Contact Image Sensor) that moves in a predetermined direction while being in close contact with an inner surface of a document table on which a single-leaf document or an open book is placed. ), Guide rails provided so as to maintain a certain distance from the inner surface of the document table, and CIS driving means for moving the CIS in the predetermined direction along the guide rails, The cross-sectional shape in the predetermined direction is formed in a mountain shape so that the central part is higher than both end parts, and the first flat part and the second flat part inclined in opposite directions to each other, and a predetermined part in the central part A cylindrical portion having a radius, and the first plane portion, the cylindrical portion, and the second plane portion are integrally formed seamlessly, and the guide rail has a central portion in the predetermined direction. Is both ends A first linear portion and a second linear portion which are formed in a mountain shape so as to be higher than each other and are inclined in opposite directions, and an arc-shaped portion having a predetermined radius in the central portion, and the first straight line The part, the arc-shaped part and the second straight part may be formed integrally without any joint.

1 is a front sectional view showing a configuration of an image forming apparatus using an image reading apparatus according to an embodiment of the present invention. FIG. 3 is an enlarged view showing details of a central portion of a document table in the image reading apparatus (image reading unit).

Explanation of symbols

1 Image forming apparatus 10 Image reading unit (image reading apparatus)
11 Housing 20 Original Plate 21 Inner Surface 22 (Original Plate) Outer Surface 23 (Original Plate) Central 24 (Original Plate) First End 25 (Original Plate) Second End 26 (Original) First flat surface portion 27 (of the document table) Cylindrical portion 28 (of the document table) Second flat surface portion 30 (of the document table) CIS (Contact Image Sensor)
40 CIS drive mechanism 41 guide rail 41a center portion 41b (of guide rail) first end portion 41c (of guide rail) second end portion 41d (of guide rail) first straight portion 41e (of guide rail) ) Arc-shaped portion 41f Second linear portion 50 (of guide rail) Image forming portion (image forming means)
60 control unit (A / D conversion means, image data processing means, image data storage means, CIS drive control means, document discrimination means)
61 Load sensors 62a, 62b, 62c, 62d Position sensors

Claims (5)

An original platen formed of a translucent material, on which an original leaf or an open book is placed;
A microlens array arranged in the first direction, an image sensor in which pixels are arranged at the focal position of each microlens, and a strip-shaped illumination having a predetermined width in each of the first direction and the second direction orthogonal to the first direction A CIS (Contact Image Sensor) that has illumination means for irradiating light along the microlens array and is moved in the second direction while being in close contact with the inner surface of the document table;
A guide rail provided to maintain a certain distance from the inner surface of the document table;
CIS driving means for moving the CIS in the second direction along the guide rail;
A / D conversion means for converting analog signals output from the image sensor into image data composed of digital signals;
Image data processing means for performing predetermined processing on the A / D converted image data;
Image data storage means for storing image data subjected to predetermined processing;
In an image forming apparatus including an image forming unit that forms an image on recording paper using image data that has been subjected to predetermined processing.
The document table is formed in a mountain shape so that the cross-sectional shape in the second direction is higher than the both end portions in the second direction, and gradually from the first end portion toward the central portion in the second direction. A first flat portion formed to be higher, a cylindrical portion formed at the central portion and having a predetermined first radius R1, and gradually lowered from the central portion toward the second end portion. The second flat portion is formed, and the first flat portion, the cylindrical portion, and the second flat portion are integrally formed without a seam so as to have the same uniform thickness. ,
The guide rail is formed in a mountain shape so that the central portion is higher than both ends in the second direction, and gradually increases from the first end toward the central portion in the second direction. A first linear portion formed, an arc-shaped portion having a predetermined second radius R2 formed in the central portion, and a first linear portion formed so as to be gradually lowered from the central portion toward the second end portion. It has two straight portions, and the first straight portion, the arc-shaped portion, and the second straight portion are integrally formed with no seam so as to have the same uniform distance with respect to the inner surface of the document table. Has been
The CIS driving means moves the CIS at the first speed V1 in the first straight portion and the second straight portion of the guide rail, and moves the CIS at the second speed V2 (V2 = V1 × R2) / R1),
As a result, an image including the vicinity of the binding portion of the book can be read clearly, and an image of a single leaf can be read without losing the image data in the center of the image. An image forming apparatus characterized in that the image data processing by the image data processing means is unnecessary.   The apparatus further comprises document discrimination means for discriminating whether the document placed on the document table is a one-leaf document or a book, and when the document placed on the document table is a book, the CIS is connected to the guide rail. The image data read by the CIS is discarded or the image data read by the CIS is discarded when passing through a predetermined range near the top of the arcuate portion. Image forming apparatus. A document table on which a single-leaf document or an open book is placed, a CIS (Contact Image Sensor) moved in a predetermined direction while being in close contact with the inner surface of the document table, and the inner surface of the document table In an image reading apparatus provided with a guide rail provided so as to maintain a certain distance, and a CIS driving means for moving the CIS in the predetermined direction along the guide rail,
The document table is formed in a mountain shape so that a cross-sectional shape thereof in the predetermined direction is higher than both ends, and a first plane part and a second plane part inclined in opposite directions to each other, and the center A cylindrical portion having a predetermined radius in the portion, and the first plane portion, the cylindrical portion and the second plane portion are integrally formed seamlessly,
The guide rail is formed in a mountain shape so that a central portion is higher than both end portions in the predetermined direction, and a first linear portion and a second linear portion that are inclined in opposite directions, and a predetermined portion in the central portion. An arc-shaped portion having a radius, and the first linear portion, the arc-shaped portion, and the second linear portion are integrally formed seamlessly;
Accordingly, an image reading apparatus that can clearly read an image including the vicinity of a binding portion of a book and can read a one-leaf image without losing image data at the center of the image.   The CIS driving means moves the CIS at a first speed in the first linear portion and the second linear portion of the guide rail, and makes the image reading speed on the outer surface of the document table constant. The image reading apparatus according to claim 3, wherein the CIS is moved at a second speed slower than the first speed in the arcuate portion. The apparatus further comprises document discrimination means for discriminating whether the document placed on the document table is a one-leaf document or a book, and when the document placed on the document table is a book, the CIS is connected to the guide rail. 5. The method according to claim 3 or 4, wherein when passing through a predetermined range near the top of the arcuate portion, the image is not read by the CIS, or the image data read by the CIS is discarded. The image reading apparatus described.

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