Reading device

Abstract

To increase accuracy of identification of a reading start position of a copy, and to materialize miniaturization of a reading device.SOLUTION: A reading device (1) comprises a peripheral member (30) that is provided adjacent to a light transmission member (20). A reference hole (50) is formed in the back side (31) of the peripheral member (30). The reference hole (50) assumes an approximately dogleg shape. First and second edges forming an edge of the reference hole (50) are edges on the inside of the approximately dogleg shape of the reference hole (50).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a reading device. [Background technology]

[0002] In a reading device capable of reading an original by a flatbed method, a reading unit that reads one line along the main scanning direction is provided movable in the sub-scanning direction below a light-transmitting member on which the original is placed.

[0003] In a conventional reading device, a tape having a white area and a black area is provided under a peripheral member provided adjacent to a light-transmitting member. The reading device determines a home position, which is the origin position of the reading unit, by reading the tape with a reading unit. Since the reading start position, which is a predetermined distance away from the home position in the sub-scanning direction, is shifted from the design value due to the attachment of the tape, the conventional reading device provides a rectangular reference hole on the underside of the peripheral member, reads the rectangular reference hole with the reading unit, and corrects the reading start position based on the edge of the read reference hole.

[0004] Patent Document 1 discloses an image reading device that includes a transparent document placement plate on which a document is placed, a reading unit that reads the document placed on the document placement plate, and a reference position identifying plate having a reference mark hole. In the image reading device disclosed in Patent Document 1, the reference mark hole has a rectangular shape that includes a first edge parallel to a direction perpendicular to a predetermined direction and a second edge parallel to the predetermined direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-227971 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the image reading device disclosed in Patent Document 1, when reading a rectangular reference hole using a reading unit and determining the edges of the reference hole that serve as the reference, it is necessary to read the periphery of the outer edge of the reference hole, including the edges of the reference hole, which creates the problem that the size of the surrounding parts becomes larger by the periphery of the outer edge of the reference hole.

[0007] An object of one aspect of the present invention is to improve the accuracy of identifying the start position for reading an original document and to realize a compact reading device. [Means for solving the problem]

[0008] In order to solve the above problem, a reading device according to one embodiment of the present invention includes a light-transmitting member on whose surface an original is placed, a peripheral member disposed adjacent to the light-transmitting member around the light-transmitting member, a reading unit disposed on the back side of the light-transmitting member and the peripheral member and moving over a range including the light-transmitting member and the peripheral member to read, and a control unit, wherein a reference hole is formed on the back side of the peripheral member, and the control unit executes a reading process to have the reading unit read a reading range including the reference hole, determines a reference point where the respective positions of a first edge and a second edge that form the edge of the reference hole intersect based on the reading result read by the reading unit, and determines a start position for reading the original by the reading unit from the reference point, wherein the reference hole is approximately L-shaped, and the first edge and the second edge are inner edges of the approximately L-shaped reference hole.

[0009] In a conventional reading device, when the reference hole is rectangular, in order to determine the reference point where the first edge and the second edge of the reference hole intersect, it is necessary to search the first edge and the second edge from a search origin outside the reference hole, and therefore it is necessary to read a wide reading range. In the reading device having the above configuration, the reference hole is approximately V-shaped, and the search origin can be provided on the bent side of the approximately V-shaped shape formed by the first edge and the second edge. When the reference hole is approximately V-shaped, the reading device can reduce the size of the surrounding members compared to a rectangular reference hole.

[0010] The first edge and the second edge of the reference hole may be perpendicular to each other.

[0011] The reference hole may have a substantially T-shape including the first edge and the second edge.

[0012] In the reading process, the control unit may set a search origin outside the reference hole and on the bent side of the approximately L-shaped form formed by the first edge and the second edge, cause the reading unit to read a reading range including the reference hole and the search origin, search for the respective positions of the first edge and the second edge from the search origin based on the reading results read by the reading unit, and determine the reference point based on the search.

[0013] A reading device according to one embodiment of the present invention includes a light-transmitting member on whose front surface an original is placed, a peripheral member disposed adjacent to the light-transmitting member around the light-transmitting member, a reading unit disposed on the back side of the light-transmitting member and the peripheral member and moving over a range including the light-transmitting member and the peripheral member to read, and a control unit, wherein a reference hole is formed on the back side of the peripheral member, and the control unit executes a reading process to have the reading unit read a reading range including the reference hole, determines a reference point where the respective positions of a first edge and a second edge that form an edge of the reference hole intersect based on a reading result read by the reading unit, and determines a start position for reading the original by the reading unit from the reference point, wherein the reference holes have a first reference hole and a second reference hole, the first reference hole has the first edge, and the second reference hole has the second edge, and an extension line of the first edge of the first reference hole and an extension line of the second edge of the second reference hole form an approximately L-shape.

[0014] An extension line of the first edge of the reference hole and an extension line of the second edge of the reference hole may be perpendicular to each other.

[0015] In the reading process, the control unit may set a search origin outside the reference hole and on the bent side of the approximately L-shaped shape formed by the extension line of the first edge and the extension line of the second edge, cause the reading unit to read a reading range including the reference hole and the search origin, search for the respective positions of the first edge and the second edge from the search origin based on the reading results read by the reading unit, and determine the reference point based on the search. Effect of the Invention

[0016] According to one aspect of the present invention, it is possible to improve the accuracy of identifying the start position for reading an original document and to realize a miniaturized reading device. [Brief description of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view showing a cross-sectional configuration of a reading device according to a first embodiment of the present invention. [Diagram 2] 2 is a diagram showing the configuration of a light transmitting member as viewed from the device main body side in the reading device shown in FIG. 1. [Diagram 3] 2 is a block diagram showing an electrical configuration of the reading device shown in FIG. 1. [Figure 4] 2 is a schematic diagram showing the configuration of a reference hole formed on the back surface of a peripheral member included in the reading device shown in FIG. 1. [Diagram 5] FIG. 13 is a diagram for explaining a correction value, which is the difference between (A) the distance in the sub-scanning direction between the home position position and a reference point in an actual reading device, and (B) the distance in the sub-scanning direction between the home position position and a reference point in a designed reading device. [Figure 6] 4 is a flowchart showing the content of a correction value calculation process performed by the reading device shown in FIG. [Figure 7] 13 shows an edge image, which is the result of reading a reading range including a reference hole by a CIS unit and is an image after edge enhancement processing and the like have been performed. [Figure 8] 2 is a cross-sectional view showing a state in which a reference hole is illuminated by a light source provided in a reading unit of the reading device shown in FIG. 1. [Figure 9] 4 is a flowchart showing the contents of a document reading process performed by the reading device shown in FIG. [Figure 10] 10 is a schematic diagram showing the configuration of a reference hole 50A formed on the back surface of a peripheral member included in a reading device according to a second embodiment of the present invention. FIG. [Figure 11] 13 is a schematic diagram showing the configuration of a reference hole formed on the back surface of a peripheral member included in a reading device according to a third embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] [Embodiment 1] <General configuration of reading device 1> Fig. 1 is a cross-sectional view showing a cross-sectional configuration of a flatbed type reading device 1 according to a first embodiment of the present invention. Fig. 2 is a diagram showing a configuration of a light transmitting member 20 seen from the device body 11 side in the reading device 1 shown in Fig. 1.

[0019] 1, the reading device 1 includes a device body 11, a document cover 12, a light-transmitting member 20, a peripheral member 30, and a CIS (Contact Image Sensor) unit 40 (an example of a reading unit). The document cover 12 is connected to the device body 11 so as to be rotatable.

[0020] The light transmitting member 20 is provided on the upper side of the device body 11. As shown in Fig. 2, a document MS is placed on a surface 21 of the light transmitting member 20. The light transmitting member 20 is a flat member made of a transparent material, such as a glass plate. When the document cover 12 is closed relative to the device body 11, the light transmitting member 20 is covered by the document cover 12.

[0021] The peripheral member 30 is provided adjacent to the light transmitting member 20 around the light transmitting member 20. The peripheral member 30 is provided on the upper side of the device body 11. A reference hole 50 is formed on the rear surface 31 side of the peripheral member 30. In addition, a reference portion 60 is provided on the rear surface 31. The reference portion 60 is, for example, a tape, and is attached to the rear surface 31 so as to extend in the X direction. Since the reference portion 60 is configured by attaching it to the rear surface 31 with the tape, there is a possibility that an artificial tolerance may occur.

[0022] The reference portion 60 is composed of a white region 61 except for a part, and the portion of the reference portion 60 other than the white region 61 is composed of a black region 62. The black region 62 is formed at both end portions in the X direction of the reference portion 60. The black region 62 is formed at the corners on the positive Y direction side of the both end portions. As a result, in the vicinity of both end portions in the X direction of the reference portion 60, the white region 61 and the black region 62 are adjacent to each other in the X direction and the Y direction.

[0023] The reading device 1 uses the CIS unit 40 to read the reference portion 60 and detect the boundary between the white area 61 and the black area 62. The boundary detected by the reading device 1 is the home position HP. The home position HP is the origin position (coordinates) when the CIS unit 40 moves in the sub-scanning direction (Y direction).

[0024] The CIS unit 40 is provided on the rear surface 22 of the light transmitting member 20 and the rear surface 31 of the peripheral member 30, and is provided to be movable over a range including the light transmitting member 20 and the peripheral member 30 in the sub-scanning direction which is the Y direction. As shown in FIG. 8, the CIS unit 40 includes a light source (not shown), a light guide 41, and a photoelectric conversion element 42.

[0025] The light source includes three LEDs (Light Emitting Diodes) of red, green, and blue. The light guide 41 is a member that propagates light from the light source, is made of a transparent material, and extends in the main scanning direction, which is the X direction perpendicular to the sub-scanning direction.

[0026] The photoelectric conversion element 42 is a plurality of photoelectric conversion elements arranged in a line in the main scanning direction. Light from a light source is irradiated onto the object to be read through a light guide 41, and the reflected light reflected by the object to be read is incident on the photoelectric conversion element 24. The photoelectric conversion element 24 converts the incident reflected light into an electric signal, and the electric signal is converted into image data for each pixel having a density of 8 bits (0 to 255) by an AD conversion circuit (not shown). Thus, the CIS unit 40 reads one line in the main scanning direction. The CIS unit 40 can read the document MS placed on the peripheral member 30 and the light transmitting member 20 by moving along the sub-scanning direction.

[0027] <Electrical configuration of the reading device 1> Fig. 3 is a block diagram showing an electrical configuration of the reading device 1 shown in Fig. 1. As shown in Fig. 3, the reading device 1 includes an ASIC (Application Specific Integrated Circuit) 5, a ROM (Read Only Memory) 7, a RAM (Random Access Memory) 8, and an NVRAM (Non-Volatile Random Access Memory) 9.

[0028] The ASIC 5 has a CPU 6. The CPU 6 performs processing according to a program read from the ROM 7, and controls each part of the reading device 1 while storing the results of the processing in the RAM 8 or the NVRAM 9. The CPU 6 is an example of a control part. The ASIC 5 is electrically connected to the CIS unit 40, the ROM 7, the RAM 8, and the NVRAM 9.

[0029] The ROM 7 stores various programs, including, for example, programs for controlling each part of the reading device 1. The ROM 7 is a non-volatile memory. The RAM 8 is a volatile memory used as a working area when the CPU 6 executes various programs and as a temporary storage area for data. The NVRAM 9 is a rewritable non-volatile memory. The ROM 7, RAM 8, and NVRAM 9 are examples of storage parts.

[0030] <Configuration of reference hole 50> FIG. 4 is a schematic diagram showing the configuration of the reference hole 50 formed on the back surface 31 of the peripheral member 30 included in the reading device 1 shown in FIG. 1 and FIG. 2. As shown in FIG. 4, the shape of the reference hole 50 is an L-shaped hole that is an approximately L-shaped hole. The reference hole 50 has a first edge 51 and a second edge 52 that form the inner edge of the approximately L-shaped hole. The first edge and the second edge are perpendicular to each other. The intersection of the first edge 51 and the second edge 52 is the reference point KP1. As will be described later, the reading device 1 determines the coordinates of the reference point KP1 from the home position HP by reading the reading range including the reference hole 50 using the CIS unit 40.

[0031] <Displacement between the actual home position and the designed home position in the reading device 1> Figure 5 is a diagram to explain the correction value HV, which is the difference between (A) the distance L in the sub-scanning direction between the position of the home position HP in an actual reading device 1 and the reference point KP1, and (B) the distance LR in the sub-scanning direction (Y direction) between the position of the home position HPR in a designed reading device and the reference point KP1.

[0032] The reference hole 50 is a hole provided in the peripheral member 30, which is a resin molded product, and there is almost no variation in the positional relationship of the reference hole 50 between the actual reading device 1 and the designed reading device.

[0033] Since the reference portion 60 is formed by attaching it with tape, there is a possibility that variation may occur between the position of the reference portion 60 of the reading device 1 and the designed reading device, and this variation is the correction value HV, which is the difference between the distance L and the distance LR.

[0034] The position of the home position HP is the origin when the CIS unit 40 moves in the sub-scanning direction (Y direction), and the Y coordinate is zero. For example, when the reading device 1 reads the original MS using the CIS unit 40 from the reading start position YP, which is the end of the light transmitting member 20, if the position of the home position HP is shifted, the end of the light transmitting member 20 cannot be read accurately.

[0035] <Calculation process of correction value by reading device 1> FIG. 6 is a flowchart showing the process of calculating the correction value HV by the reading device 1.

[0036] The CPU 6 executes home position detection (S1). In the home position detection, the CPU 6 executes the following process. The CPU 6 moves the CIS unit 40 at least to the end side of the peripheral member 30 from the reference portion 60. After that, the CPU 6 moves the CIS unit 40 from that position in the sub-scanning direction (Y direction) while causing the CIS unit 40 to read the peripheral member 30 line by line. The CPU 6 detects the home position HP, which is the boundary between the white area 61 and the black area 62, from an image obtained by reading the white area 61 and an image obtained by reading the black area 62 by the CIS unit 40.

[0037] The CPU 6 determines the black and white reference position RP1 to be the origin coordinate (X=0, Y=0) from the positions of the white area 61 and the black area 62 read by the CIS unit 40 (S2). The black and white reference position RP1 is the intersection of a boundary line BL1 between the white area 61 and the black area 62 in the X direction and a home position HP, which is the boundary line between the white area 61 and the black area 62 in the Y direction.

[0038] After detecting the home position (S1), the CPU 6 moves the CIS unit 40 from the home position HP (Y=0) along the sub-scanning direction (Y direction) while reading the reading range including the reference hole 50 by the CIS unit 40, and stores the image data of the read image in the RAM 8 (S3). The process of S3 by the CPU 6 is an example of a reading process.

[0039] The CPU 6 detects coordinate information of the reference point KP1 of the reference hole 50 from the image data of the reading range including the reference hole 50 stored in the RAM 8 in step S3 (S4). The coordinate information of the reference point KP1 is a coordinate from the origin coordinate (X=0, Y=0) of the home position. Step S4 will be specifically described below.

[0040] In step S3, the CPU 6 executes edge enhancement processing on the image data stored in the RAM 8. In the edge enhancement processing, a pixel of interest in the image data and pixels surrounding the pixel of interest are multiplied by a predetermined filter coefficient, so that the density of pixels with strong vertical and horizontal connections is enhanced, and pixel portions with high continuity in the image data are enhanced.

[0041] The CPU 6 performs a binarization process on the image data that has been subjected to the edge enhancement process. The binarization process is performed by setting the pixel value of the pixel of interest to "1" if the density of the pixel of interest is equal to or greater than a predetermined threshold, and by setting the pixel value of the pixel of interest to "0" if the density of the pixel of interest is less than the predetermined threshold. The CPU 6 performs a black-white inversion process on the image that has been subjected to the binarization process.

[0042] 7 shows an edge image EG, which is the result of reading the reading range including the reference hole by the CIS unit 40 and is the image after black and white inversion processing is performed by the CPU 6. The edge image EG shows the edge of the reference hole 50 as a black line that is a collection of pixel values ​​of "1", and there are circular black lines as a result of reading dust attached to the peripheral member 30. In the edge image EG, everything other than the edge of the reference hole 50 and the dust attached to the peripheral member 30 is represented by "0".

[0043] In order to detect the positions of the first edge 51 and the second edge 52 of the reference hole 50, the CPU 6 sets a search origin TG at a position outside the reference hole 50 within the edge image EG, i.e., the reading range. The search origin TG is set outside the reference hole 50 and on the bent side of the approximately L-shaped portion formed by the first edge 51 and the second edge 52.

[0044] In order to determine the position of the first edge 51E, the CPU 6 searches for pixel values ​​in the -Y direction as indicated by the arrow A1 in FIG. 7 with the search origin TG as the origin for the edge image EG on which the black-and-white inversion process has been performed. When the CPU 6 first finds a pixel whose pixel value is "1" during the pixel value search in the Y direction, the CPU 6 sets the pixel as a candidate pixel for the first edge 51E. From a new search origin that is shifted a predetermined distance in the -X direction from the search origin TG, the CPU 6 again searches for pixel values ​​in the -Y direction as indicated by the arrow A1, and when the CPU 6 finds a pixel whose pixel value is "1", the CPU 6 sets the pixel as a candidate pixel for the first edge 51E. The CPU 6 sets a new search origin by shifting the predetermined distance in the -X direction from the search origin TG, and repeatedly executes the determination of candidate pixels for the first edge 51E. As a result, the CPU 6 determines a plurality of candidate pixels for the first edge 51E.

[0045] The CPU 6 extracts a distribution with a high Y coordinate of the candidate pixels from among the multiple candidate pixels of the first edge 51E, and calculates the average of the Y coordinates to determine the Y coordinate of the first edge 51E, i.e., the Y coordinate of the first edge 51 of the reference hole 50. Note that the reason for extracting a distribution with a high Y coordinate of the candidate pixels from among the multiple candidate pixels of the first edge 51E is to prevent dust adhering to the peripheral member 30 from being considered as the first edge 51E.

[0046] Next, in order to determine the position of the second edge 52E, the edge image EG on which the black-and-white inversion process has been performed is searched for pixel values ​​in the -X direction as indicated by the arrow B1 in FIG. 7 with the search origin TG as the origin. When the CPU 6 first finds a pixel whose pixel value is "1" during the pixel value search in the -X direction, the pixel is determined as a candidate pixel for the second edge 52E. From a new search origin that is shifted a predetermined distance in the -Y direction from the search origin TG, the CPU 6 searches for pixel values ​​in the -X direction as indicated by the arrow B1, and when a pixel whose pixel value is "1" is found, the pixel is determined as a candidate pixel for the second edge 52E. The CPU 6 sets a new search origin by shifting the predetermined distance in the -X direction from the search origin TG, and repeatedly executes the determination of candidate pixels for the second edge 52E. As a result, the CPU 6 determines a plurality of candidate pixels for the second edge 52E.

[0047] The CPU 6 extracts a distribution of candidate pixels with a large number of X coordinates from among the multiple candidate pixels of the second edge 52E, and calculates the average of the X coordinates to determine the X coordinate of the second edge 52E, i.e., the X coordinate of the second edge 52 of the reference hole 50.

[0048] The CPU 6 sets the determined Y coordinate of the first edge 51 as the Y coordinate of the reference point KP1, and sets the determined X coordinate of the second edge 52 as the X coordinate of the reference point KP1. In this manner, the CPU 6 determines the coordinate of the reference point KP1.

[0049] The extension direction of the first edge 51 and the second edge 52 may be a direction that is inclined with respect to both the X direction and the Y direction. The first edge 51 and the second edge 52 may form an approximately dogleg shape. In this case, in step S4, the CPU 6 searches for pixel values ​​in the same direction as the preset extension direction of the second edge 52, and detects the position of the first edge 51. The CPU 6 also searches for pixel values ​​in the same direction as the preset extension direction of the first edge 51, and detects the position of the second edge 52.

[0050] The CPU 6 calculates a correction value HV based on the Y coordinate of the detected reference point KP1 and the distance LR in the Y direction from the designed home position HPR to the reference point KP1, as shown in the following (Equation 1) (S5).

[0051] Correction value HV = Y coordinate of reference point KP1 - distance LR (Equation 1) The CPU 6 calculates a correction value HV by subtracting the distance LR from the Y coordinate of the determined reference point KP1.

[0052] The CPU 6 stores the correction value HV calculated in step S5 in the NVRAM 9. The distance LR in the Y direction from the designed home position HPR to the reference point KP1 is stored in the ROM 7.

[0053] Fig. 8 is a cross-sectional view showing a state in which the reference hole 50 is illuminated by a light source included in the CIS unit 40 of the reading device 1 shown in Fig. 1. As shown in Fig. 8, the CIS unit 40 has a light guide 41 and a photoelectric conversion element 42. The reference hole 50 is illuminated with light from the light guide 41 at an angle.

[0054] <Reading process of original MS by reading device 1> 9 is a flowchart showing the contents of the reading process of the original MS by the reading device 1. When reading the original MS using the CIS unit 40 from the reading start position YP, which is the end of the light transmitting member 20, the reading device 1 needs to obtain the actual distance DI from the home position HP to the reading start position YP.

[0055] 9, first, the CPU 6 determines the Y coordinate of the reading start position YP of the CIS unit 40 by the following method (S21). Information on the distance LKY in the Y direction between the reference point KP1 and the light transmitting member 20 is stored in advance in the ROM 7. There is almost no possibility that the distance LKY will vary between the actual reading device 1 and the designed reading device.

[0056] By adding the distance LKY to the Y coordinate of the reference point KP1 of the reference hole 50, the CPU 6 determines the Y coordinate of the reading start position YP from the origin coordinate of the home position HP (S22). Note that the Y coordinate of the reading start position YP may be determined from the origin coordinate of the home position HP using the correction value HV.

[0057] As a result, even if the attachment position of the reference portion 60 is shifted from the predetermined design position, the CPU 6 can determine the Y coordinate of the reading start position YP.

[0058] Since the CPU 6 determines the start reading position YP of the original MS using the coordinate information of the reference point KP1 determined in step S4, the CPU 6 identifies the start reading position YP from the position of the first edge 51 and the position of the second edge 52 read by the CIS unit 40.

[0059] After step S21, the CPU 6 outputs a control signal to the CIS unit 40 to read the original MS placed on the front surface 21 of the light transmitting member 20, from the reading start position YP of the original MS identified in step S21. The CIS unit 40 reads the original MS from the reading start position YP of the original MS.

[0060] In the conventional reading device, when the reference hole has a rectangular shape, it is necessary to provide a search origin for searching the first edge and the second edge outside the reference hole. There is a problem that the size of the peripheral members of the conventional reading device becomes large by providing the search origin outside the reference hole. In contrast, the shape of the reference hole 50 of the reading device 1 is an L-shape, which is an approximately L-shape, and the search origin TG can be provided on the bending side of the approximately L-shape formed by the first edge 51 and the second edge 52. When the reference hole is an approximately L-shape, the reading device 1 can reduce the size of the peripheral members 30 compared to a rectangular reference hole.

[0061] Consider a case where the settings for reading the original MS by the CIS unit 40 are set to start reading from the reading start position YP, which is the end of the light transmitting member 20, as described above, and the attachment position of the reference portion 60 is shifted from the desired position. Even in such a case, the CIS unit 40 reads the positions of the first edge 51 and the second edge 52, so that it is possible to prevent the CIS unit 40 from reading the peripheral member 30 on the outside of the original MS when reading the original MS.

[0062] Furthermore, in the reading device 1, the first edge 51 extends in the X direction and the second edge 52 extends in the Y direction, so that a sufficient width can be secured for searching in both the X direction and the Y direction in step S4. Therefore, compared to the case of reading the position of a rectangular reference hole whose width is small in the X direction or the Y direction, the CPU 6 can sufficiently detect the positions of the first edge 51 and the second edge 52 even if a foreign object is attached near the reference hole.

[0063] [Embodiment 2] A second embodiment of the present invention will be described below. For ease of explanation, the same reference numerals are used for members having the same functions as those described in the first embodiment, and the explanations thereof will not be repeated. Fig. 10 is a schematic diagram showing the configuration of a reference hole 50A formed on a rear surface 31 of a peripheral member 30 included in a reading device according to the second embodiment of the present invention.

[0064] 10, the reference hole 50A has a substantially T-shape including a first edge 51 and a second edge 52. Even in the case of the reference hole 50A having a substantially T-shape, the CPU 6 can provide a search origin TG on the outer side of the reference hole 50A, on the bending side of the substantially L-shape formed by the first edge 51 and the second edge 52. The reference point KP2 is a point where the first edge 51 and the second edge 52 intersect. The CPU 6 can determine the coordinates of the reference point KP2 by determining the positions of the first edge 51 and the second edge 52 from the search origin TG in the same manner as in the first embodiment.

[0065] [Embodiment 3] A third embodiment of the present invention will be described below. For ease of explanation, the same reference symbols are used for members having the same functions as those described in the first embodiment, and their explanations will not be repeated. Fig. 11 is a schematic diagram showing the configuration of a reference hole formed on the back surface 31 of a peripheral member 30 included in a reading device according to the third embodiment of the present invention. In this embodiment, the reference hole has a first reference hole 50B and a second reference hole 50C.

[0066] As shown in FIG. 11, a first reference hole 50B including a first edge 51 and a second reference hole 50C including a second edge 52 may be formed on the rear surface 31 side of the peripheral member 30. The reference points KP3 and KP4 are points where an extension line of the first edge 51 intersects with the second edge 52. Even in this case, the extension line of the first edge 51 of the first reference hole 50B and the extension line of the second edge 52 of the second reference hole 50C form an approximately V-shape with respect to the search origin TG where a first straight line L1 perpendicular to the first edge 51 and a second straight line L2 perpendicular to the second edge 52 intersect, and the search origin TG is on the bent side of the approximately V-shape. In addition, the extension line of the first edge 51 and the extension line of the second edge 52 are perpendicular to each other.

[0067] The CPU 6 can determine the coordinates of the reference point KP3 in (A) of Figure 11 and the coordinates of the reference point KP4 in (B) of Figure 11 by determining the positions of the first edge 51 and the second edge 52 from the search origin TG in the same manner as that implemented in embodiment 1.

[0068] As shown in FIG. 11A, the first reference hole 50B may be disposed on the -Y direction side of the second reference hole 50C. In this case, the first edge 51 and the second edge 52 are disposed so that the Y coordinate of the first edge 51 and the minimum Y coordinate of the second edge 52 coincide with each other. Also, as shown in FIG. 11B, the area surrounded by the periphery of the first reference hole 50B and the area surrounded by the periphery of the second reference hole 50C may overlap in the Y direction. Furthermore, the first reference hole 50B and the second reference hole 50C may be connected at one point.

[0069] 11, the first reference hole 50B and the second reference hole 50C have a rectangular shape, but are not limited thereto. As long as the first edge 51 and the second edge 52 are formed, the first reference hole 50B and the second reference hole 50C may have a trapezoidal or semicircular shape, for example.

[0070] The reading device 1 may have an image forming unit that forms an image on paper in the device body 11. In the embodiment, the correction of the misalignment of the home position HP in the sub-scanning direction (Y direction) is described, but the contents of the first embodiment can also be applied to the misalignment of the home position HP in the main scanning direction.

[0071] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0072] 1 Reading device 6 CPU (control unit) 7 ROM (memory section) 20 Light-transmitting material 21 Surface of light-transmitting member 22 Back surface of light-transmitting member 30 Peripheral parts 31 Back side of peripheral parts 40 CIS unit (reader) 50, 50A Reference hole 50B 1st reference hole 50C 2nd reference hole 51 First Edge 52 The second edge MS manuscript

Claims

1. a light-transmitting member on whose surface a document is placed; A peripheral member provided adjacent to the light transmitting member around the light transmitting member; The light transmitting member and the peripheral member are provided on the rear side of the light transmitting member and the peripheral member. A reading unit that moves and reads over a range including the above. A control unit, A reference hole is formed on the rear surface side of the peripheral member, The control unit is A reading process is executed to cause the reading unit to read a reading range including the reference hole; The reference point where the first edge and the second edge that form the edge of the reference hole intersect is called the previous reference point. The distance from the reference point to the front position by the reading unit is determined based on the reading result obtained by the reading unit. A reading device that determines a reading start position of a document, The reference hole has an L-shaped bent shape, The first edge and the second edge are inner edges of the L-shaped bent shape of the reference hole. A reading device that recognizes the

2. The first edge and the second edge of the reference hole are perpendicular to each other.

2. The reading device according to claim 1.

3. The shape of the reference hole is substantially T-shaped including the L-shaped bent portion.

3. The reading device according to claim 2.

4. The control unit is In the reading process, the outside of the reference hole and the first edge and the second edge are formed A search origin is set on the bent side of the L-shaped portion, and a reading including the reference hole and the search origin is made. The reading unit reads the reading range, The positions of the first edge and the second edge are read by the reading unit. performing a search from the search origin based on the search result and determining the reference point based on the search result; 4. The reading device according to claim 1, wherein:

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