JP2019193212A - Image reading apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading device which allows a user to confirm the position of a document on a document supporting surface while the work is simple. A document cover 5 is provided so as to be openable and closable between an open state in which a contact glass is exposed and a closed state in which the contact glass is covered. As a result, the document supported on the contact glass can be pressed by the document cover 5. A part of the document cover 5 is formed of the transparent member 9, and the user can visually recognize the document supported on the contact glass through the transparent member 9. [Selection diagram] Figure 1

Description

  The present invention relates to an image reading apparatus.

  2. Description of the Related Art Conventionally, in a scanner device (image reading device) that reads an image by an FB (Flat Bed) method, a configuration has been proposed in which a transparent pressure plate can be opened and closed between a pressure plate and a contact glass (for example, Patent Documents). 1). With such a configuration, it is possible to confirm whether or not the original is displaced by closing the transparent pressure plate and bringing the original into close contact with the contact glass and visually checking the original through the transparent pressure plate.

JP 2000-235235 A

  In the proposed configuration, when a document is set, after the document is placed on the contact glass (document support surface) with the transparent pressure plate and the pressure plate (document cover) opened, the transparent platen is closed and the pressure plate (document Two operations of closing the cover) are necessary, which is troublesome for the user.

  An object of the present invention is to provide an image reading apparatus that allows a user to confirm the position of a document on a document support surface while the work is simple.

  In order to achieve the above object, an image reading apparatus according to the present invention includes a support unit having a document support surface that supports a document, a document cover that can be opened and closed with respect to the document support surface, and a document support surface. A reading sensor provided on the opposite side of the document cover and having a plurality of reading elements arranged in the main scanning direction, a moving mechanism for moving the reading sensor, and a control unit are provided, and the control unit reads by the moving mechanism. The document cover performs a reading process for causing the reading sensor to read the image of the document supported on the document support surface while moving the sensor in the sub-scanning direction extending along the document support surface perpendicular to the main scanning direction. A part of it is made of a transparent member that transmits light in the thickness direction of the document cover.

  According to this configuration, the document supported on the document support surface can be pressed by the document cover, and in this state, the image of the document can be read by the reading sensor while moving the reading sensor in the sub-scanning direction. In addition, since a part of the document cover is made of a transparent member, the user can visually recognize the document supported on the document support surface through the transparent member. Therefore, the user can confirm the position of the document on the document support surface.

  According to the present invention, the user can confirm the position of the document on the document support surface while the work is simple.

1 is a perspective view of a multifunction machine including an image reading apparatus according to an embodiment of the present invention. It is sectional drawing which shows the structure of the vicinity of the transparent member of an image reader schematically. 2 is a block diagram illustrating an electrical configuration of the image reading apparatus. FIG. It is a flowchart which shows the flow of a reading process. It is a figure for demonstrating operation | movement of the reading device at the time of a reading process. It is a flowchart which shows the flow of a lower reading setting process. It is a figure for demonstrating operation | movement of the reading device at the time of a lower reading setting process. It is a flowchart which shows the flow of an upper reading setting process. It is a figure for demonstrating operation | movement of the reading device at the time of an upper reading setting process. FIG. 10 is a diagram for describing a document size determination method when a specific image is formed on the outer periphery of a boundary frame. FIG. 5 is a diagram for explaining a document size determination method when a large document is supported on a contact glass. FIG. 6 is a diagram for explaining a method for determining a document size when a small document is supported on a contact glass. It is a figure for demonstrating the discrimination | determination method of the document size in case a document is supported on the transparent member.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Configuration of MFP>
A multi-function peripheral (MFP) 1 shown in FIG. 1 is an electronic device having a plurality of functions such as a scan function and a print function. The scan function is a function for reading an image of a document and generating image data. The print function is a function for forming an image related to image data on a sheet such as print paper. The multifunction device 1 includes an image reading device 2 for a scanning function and an image forming device 3 for a printing function.

  The image reading device 2 is stacked on the image forming device 3. The image reading device 2 includes a housing 4 and a document cover 5. The housing 4 has a substantially rectangular parallelepiped shape. The document cover 5 is provided so that it can be opened and closed between an open state and a closed state. When the document cover 5 is open, the upper surface of the housing 4 is exposed. When the document cover 5 is closed, the upper surface of the housing 4 is covered with the document cover 5.

  An operation panel 6 is disposed on one side surface of the housing 4. In the multi function device 1, the side surface on which the operation panel 6 is disposed is the front surface. For use in the following description, the left and right sides of the multifunction device 1 are defined based on the state when the multifunction device 1 is viewed from the front side. In FIGS. It shows with.

  As shown in FIG. 2, a rectangular plate-shaped contact glass 7 (an example of a support portion having a document support surface) is disposed on the upper surface of the housing 4. A rectangular window 8 that is long in the left-right direction is formed in the document cover 5 so as to penetrate in the thickness direction at a position facing the portion near the left rear corner of the contact glass 7 when the document cover 5 is closed. . A plate-like transparent member 9 is disposed on the lower surface of the document cover 5, that is, the surface facing the contact glass 7 so as to close the window 8.

  In the housing 4, a reading device 11 is provided below the contact glass 7 so as to be capable of reciprocating in the left-right direction. The reading device 11 includes a first CIS (Contact Image Sensor) 12 and a second CIS 13 in a single casing.

  The first CIS 12 is provided for reading an image of a document supported on the contact glass 7. The first CIS 12 has a reading element group 14, a light source 15 and a rod-shaped lens array 16. The reading element group 14 includes a plurality of reading elements (light receiving elements) arranged in the main scanning direction that coincides with the front-rear direction of the multifunction machine 1. Light from the light source 15 is applied to the reading target surface of the document that comes into contact with the contact glass 7, and reflected light from the reading target surface passes through the rod-shaped lens array 16 to form an image on the reading element group 14 and read. An image for one line of the target surface in the main scanning direction is satisfactorily read by the reading element group 14. The reading element group 14 outputs the read analog image signal for one line. Then, while the reading device 11 is moved in the sub-scanning direction that coincides with the left-right direction of the multifunction device 1, the image on the reading target surface is sequentially read line by line, thereby achieving reading of the image on the reading target surface.

  The image reading apparatus 2 can also read an image of a document supported on the transparent member 9 in the window 8. The second CIS 13 is provided for reading an image of a document supported on the transparent member 9. The second CIS 13 has a reading element group 17, a light source 18 and a rod-shaped lens array 19. The reading element group 17 includes a plurality of reading elements (light receiving elements) arranged in the main scanning direction that coincides with the front-rear direction of the multifunction machine 1. The reading element group 17 is arranged at the same position in the vertical direction as the reading element group 14 of the first CIS 12, but the configuration of the rod-shaped lens array 19 is different from the configuration of the rod-shaped lens array 16 of the first CIS 12. The focal length by the array 19 is larger than the focal length by the rod-shaped lens array 16. Therefore, the light from the light source 18 is applied to the reading target surface of the document that contacts the transparent member 9, and the reflected light from the reading target surface forms an image on the reading element group 17 by passing through the rod-shaped lens array 19. The image for one line in the main scanning direction on the surface to be read is satisfactorily read by the reading element group 17. The reading element group 17 outputs the read analog image signal for one line. Then, while the reading device 11 is moved in the sub-scanning direction that coincides with the left-right direction of the multi-function device 1, the image on the reading target surface is sequentially read line by line, thereby achieving reading of the image on the reading target surface.

  As shown in FIG. 1, the image forming apparatus 3 includes a housing 21, a supply cassette 22, and a discharge tray 23. The supply cassette 22 is configured to be removable from the front side of the housing 21. The supply cassette 22 is configured to be supported in a state where a plurality of sheets such as print sheets are stacked. The discharge tray 23 is formed on the upper surface of the housing 21. Sheets are fed one by one from the supply cassette 22, and the fed sheets are conveyed toward the discharge tray 23 through the housing 21. During this conveyance, an image is formed on the sheet. The image forming method may be an electrophotographic method or an inkjet method. Further, the image formed on the sheet may be a color image or a monochrome image.

<Electrical Configuration of Image Reading Apparatus>
As shown in FIG. 3, the image reading apparatus 2 includes an ASIC (Application Specific Integrated Circuit) 31, a ROM (Read Only Memory) 32, and a RAM (Random Access Memory) 33.

  The ASIC 31 includes a CPU 34 (an example of a control unit). The ROM 32 includes a rewritable nonvolatile memory such as a flash memory. The ROM 32 stores programs executed by the CPU 34 and various data. The RAM 33 is a volatile memory such as a DRAM (Dynamic Random Access Memory), and is used as a work area when the CPU 34 executes a program. The ROM 32 stores in advance position information for defining a reading range at the time of each reading based on the boundary frame 41 between the transparent member 9 and the document cover 5 and target image information indicating the boundary frame 8. The first position A is a position far from the first CIS home position in the sub-scanning direction in the boundary frame 41 as shown in FIG. 5, that is, a position away from the position indicated by the right end of the boundary frame 41 in FIG. is there. As shown in FIG. 5, the second position B is separated from the home position by a predetermined distance from the position close to the first CIS home position in the sub-scanning direction in the boundary frame 41, that is, the position indicated by the left end of the boundary frame 41 in FIG. (Right side) position. The third position C is a position away from the home position of the first CIS by a predetermined distance. The predetermined distance is an arbitrary value (for example, 30 mm) determined in advance, and this value may be different depending on each position. The fourth position D is a position close to the home position of the first CIS in the sub-scanning direction in the boundary frame 41, that is, substantially the same position as the position indicated by the left end of the boundary frame 41 in FIG. Each value is calculated from the mounting position of the transparent member 9 at the time of manufacturing the multifunction machine 1. According to the calculated value, the first CIS stores the movement distance from the home position to the first position A to the fourth position D as each value of the first position A to the fourth position D. In addition, the image of the boundary frame read by the first CIS is stored as the target image while the reading device 11 is moved from the first position A to the second position B in a state where the document is not supported by the contact glass 7.

  The CPU 34 executes a program for various processes based on information input to the ASIC 31, thereby operating the operation panel 6, the reading device 11, and the moving mechanism 35 that moves the reading device 11. Control each part. The moving mechanism 35 includes a motor as a driving source, a pulley that is rotated by the driving force of the motor, a belt wound around the pulley, and the like.

  The operation panel 6 is composed of, for example, a touch panel, and is configured by superimposing an operation unit 37 such as a pressure-sensitive or capacitive transparent film switch on a display unit 36 such as a liquid crystal display. Various information and images such as operation keys are displayed on the display unit 36. When the user performs a touch operation on the operation key displayed on the display unit 36, an instruction corresponding to the type of the operation key subjected to the touch operation is received by the operation unit 37. When the operation unit 37 receives an instruction, a signal (data) corresponding to the content of the instruction is transmitted from the operation unit 37 to the ASIC 31.

  The display unit 36 and the operation unit 37 may be provided separately and independently without constituting a touch panel.

<Reading process>
In the image reading device 2, when the operation panel 6 is operated by the user and an instruction to start reading an image of a document is given, the CPU 34 of the ASIC 31 executes a reading process (main flow) shown in FIG. Before the start of reading the image of the document is instructed, the document is supported on the contact glass 7 or the transparent member 9. When the document is supported on the contact glass 7, the document is arranged so that the left rear corner of the document matches the left rear corner of the contact glass 7. Thereafter, the document cover 5 is displaced from the open state to the closed state, and the document on the contact glass 7 is pressed toward the contact glass 7 by the document cover 5.

  In the reading process, the CPU 34 controls the moving mechanism 35 to move the reading device 11 to the first position A according to the value stored in the ROM 32 (S1). As shown in FIG. 5, the first position A is a boundary frame 41 formed by the boundary between the transparent member 9 and the portion other than the transparent member 9 on the lower surface of the document cover 5, that is, the right end of the window frame formed by the peripheral edge of the window 8. Is a position spaced a predetermined distance to the right.

  Further, the CPU 34 sets the reading range in the main scanning direction by the reading device 11 to the first range Ra1 (S2). The first range Ra1 is a range including the boundary frame 41. That is, the first range Ra1 is a range in which the front end is located on the front side of the front end of the boundary frame 41 and the rear end is located on the rear side of the rear end of the boundary frame 41.

  Thereafter, the CPU 34 controls the moving device 35 to control the reading device 11 while moving the reading device 11 from the first position A to the second position B, and from the first position A to the second position B. Pre-reading for reading the area Re1 is executed (S3). The second position B is a position at a predetermined distance (for example, 30 mm) from the left end of the boundary frame 41 to the right side. The region Re1 is read by the first CIS 12 of the reading device 11. In addition, although it may be read by the second CIS 13 of the reading device 11, in this case, each position information and target image stored in the ROM 32 stores values when read by the second CIS 13.

  The region Re1 includes the entire right edge of the boundary frame 41 and a part of each of the front edge and the rear edge. Whether the read image read in the pre-read includes the entire target image including the entire right edge of the boundary frame 41 included in the region Re1 and each of the front edge and the rear edge. It is determined whether or not (S4). When a document is present between the document cover 5 and the contact glass 7, at least a part of the boundary frame 41 is hidden by the document when viewed from the contact glass 7 side. Therefore, the entire target image is not included in the read image. On the other hand, when no document exists between the document cover 5 and the contact glass 7, the entire boundary frame 41 is not hidden by the document when viewed from the contact glass 7 side. Therefore, the entire target image is included in the read image.

  When the CPU 34 determines that the entire target image is not included in the read image (S4: NO), that is, when it is determined that the read image does not include at least a part of the target image, the CPU 34 supports the contact glass 7. Then, a lower reading setting process for setting for reading the image of the original is executed (S5). On the other hand, when the CPU 34 determines that the entire target image is included in the read image (S4: YES), the CPU 34 executes an upper reading setting process for setting for reading the image of the document supported on the transparent member 9. (S6). The lower reading setting process and the upper reading setting process will be described later in order.

  Then, after completing the lower reading setting process or the upper reading setting process, the CPU 34 performs a main reading for reading the entire image of the document (S7), and ends the reading process. For the read image, the first filter determined in step S59 or the second filter determined in step S68 is applied to the data generated in accordance with the document size determined in step S55, step S57, step S64 or step S66 described later. Image processing such as smoothing processing used is executed to generate read image data. The generated read image data is output to the set output destination.

<Lower scanning setting process>
The flow of the lower reading setting process is shown in FIG. In the lower reading setting process, the CPU 34 of the ASIC 31 determines whether or not the setting related to the document size by the user is “auto” (S51). Prior to an instruction to start reading an image of a document, the user operates the operation panel 6 to set the size of the document to be read. In this size setting, a standard size such as A4, A5 and A6 and an arbitrary size (mm) can be designated. In the size setting, “auto” in which the image reading apparatus 2 automatically determines the size of the document can be designated.

  When the setting relating to the document size is “auto” (S51: YES), the CPU 34 controls the moving mechanism 35 to move the reading device 11 from the second position B to the third position C (S52). The third position C is a position at a predetermined distance (for example, 30 mm) from the left end of the contact glass 7 to the right side.

  Further, the CPU 34 sets the reading range in the main scanning direction by the reading device 11 to the second range Ra2 (S53). As shown in FIG. 7, the second range Ra2 is a range that does not deviate from the contact glass 7 in the main scanning direction. For example, the second range Ra <b> 2 is located at a position where the front end is a predetermined distance (may be 0) from the front end of the contact glass 7 to the rear side, and the rear end is from the rear end of the contact glass 7. This is a range located at a position spaced a predetermined distance (may be 0) on the front side.

  Thereafter, the CPU 34 controls the moving mechanism 35 to control the reading device 11 while moving the reading device 11 from the third position C to the home position HP, and thereby to perform an area Re2 from the third position C to the home position. Pre-reading is executed (S54). The home position HP is substantially the same position as the left end of the contact glass 7. The region Re2 may be read by the first CIS 12 of the reading device 11 or may be read by the second CIS 13.

  When the reading of the area Re2 is completed, the CPU 34 detects the edge of the read image by analyzing the read image, and determines the size specified from the detected edge as the size at the time of the main reading (S55). That is, the edge of the front end of the document can be detected from the read image obtained by reading the region Re2 by a known edge detection method. Accordingly, it is specified from the position of the edge of the front end that the standard document size having the document width is the size of the document at the time of actual reading.

  On the other hand, when the setting relating to the document size is not “auto” (S51: NO), that is, when the user specifies a standard size or an arbitrary size in the setting relating to the document size, the CPU 34 controls the moving mechanism 35. Then, the reading device 11 is moved from the second position B to the home position HP (S56). Then, the CPU 34 determines the size set by the user as the size at the time of actual reading (S57).

  Thus, when the size at the time of the main reading is determined, the CPU 34 determines to use the first CIS 12 of the reading device 11 for the main reading (S58), and determines to use the first filter for the smoothing process. (S59), the lower reading setting process is terminated.

<Upper reading setting process>
The flow of the upper reading setting process is shown in FIG. In the upper reading setting process, the CPU 34 of the ASIC 31 determines whether or not the setting related to the size of the original by the user is “auto” (S61). When the setting relating to the document size is “auto” (S61: YES), the CPU 34 sets the reading range in the main scanning direction by the reading device 11 to the third range Ra3 (S62). The third range Ra3 is a range that does not deviate from the boundary frame 41 in the main scanning direction, as shown in FIG. For example, the third range Ra3 is located at a position where the front end is a predetermined distance (may be 0) from the front end of the boundary frame 41 to the rear side, and the rear end is from the rear end of the boundary frame 41. This is a range located at a position spaced a predetermined distance (may be 0) on the front side.

  Thereafter, the CPU 34 controls the moving mechanism 35 to control the reading device 11 while moving the reading device 11 from the second position B to the fourth position D, and from the second position B to the fourth position D. Pre-reading for reading the area Re3 is executed (S63). The fourth position D is substantially the same position as the left end position of the boundary frame 41. The region Re3 may be read by the first CIS 12 of the reading device 11 or may be read by the second CIS 13.

  When the reading of the region Re3 is completed, the CPU 34 detects the edge of the read image by analyzing the read image, and determines the size specified from the detected edge as the size at the time of the main reading (S64). In other words, from the read image obtained by reading the region Re3, the front edge and the rear edge of the document can be detected by a known edge detection method. Accordingly, the distance between the front edge and the rear edge can be obtained, and the size of the document can be specified from the distance.

  On the other hand, when the setting relating to the document size is not “auto” (S61: NO), that is, when the user specifies a standard size or an arbitrary size in the setting relating to the document size, the CPU 34 controls the moving mechanism 35. Then, the reading device 11 is moved from the second position B to the fourth position D (S65). Then, the CPU 34 determines the size set by the user as the size at the time of actual reading (S66).

  Thus, when the size at the time of the main reading is determined, the CPU 34 determines to use the second CIS 13 of the reading device 11 for the main reading (S67), and determines to use the second filter for the smoothing process. (S68), the upper reading setting process is terminated. Note that the second filter is set to be less smoothed and stronger than the first filter.

<Effect>
As described above, the document cover 5 is provided so as to be openable and closable in the open state in which the contact glass 7 is exposed and in the closed state in which the contact glass 7 is covered, so that the document supported on the contact glass 7 can be opened. It can be pressed with. In this state, the image of the document can be read by the reading device 11 while moving the reading device 11 in the sub-scanning direction. In addition, since a part of the document cover 5 is composed of the transparent member 9, the user can visually recognize the document supported on the contact glass 7 through the transparent member 9. Therefore, the user can confirm the position of the document on the contact glass 7.

  Further, the reading device 11 includes a first CIS 12 and a second CIS 13, and when the original is supported on the contact glass 7, the first CIS 12 suitable for reading an image of the original on the contact glass 7 is provided. Used for actual reading. On the other hand, when the document is supported on the transparent member 9, the second CIS 13 suitable for reading the image of the document on the transparent member 9 is used for the main reading. As a result, regardless of whether the document is supported on the contact glass 7 or the transparent member 9, the image of the document can be read satisfactorily.

  Further, when reading an image of a document on the transparent member 9, there are cases where it is not sufficient to use CIS having different focal lengths. That is, depending on the material of the transparent member and the air layer between the contact glass 7 and the transparent member 9, there is a possibility that it is not possible to cope with it by simply changing the focal length. Even in such a case, it is possible to generate read image data representing an image in which the deterioration of the image quality is reduced by changing the filter of the smoothing process.

  In the reading process, pre-reading for reading the region Re1 is executed, and all of the right edge of the boundary frame 41 included in the region Re1 and each of the front edge and the rear edge are added to the read image read by the pre-reading. It is determined whether or not the entire target image made up of parts is included. When it is determined that the entire target image is not included in the read image, the main reading is performed according to the size of the document supported on the contact glass 7. On the other hand, when it is determined that the entire target image is included in the read image, the main reading is executed according to the size of the document supported on the transparent member 9. As a result, it is possible to obtain image data of an appropriate size without performing useless processing such as moving the reading device 11 to a range that does not have a document image.

  When the size of the document supported on the contact glass 7 is automatically determined, in reading the area Re2 necessary for specifying the size, a third position spaced a predetermined distance from the left end to the right side of the contact glass 7 is used. A region Re2 from C to the home position that is substantially the same position as the left end of the contact glass 7 is read. Since the boundary frame 41 is not included in the region Re2, it is possible to suppress erroneous detection of the boundary frame 41 as an edge of the document.

  When the document is supported on the contact glass 7, the reading range in the main scanning direction is set to the second range Ra2 at the time of pre-reading for determining the size of the document. When the document is supported on the transparent member 9, the reading range in the main scanning direction is set to the third range Ra3 that is narrower than the second range Ra2 during pre-reading for determining the size of the document. The As a result, when the original is supported on the transparent member 9, it is possible to suppress reading to an unnecessary area by pre-reading, and dust attached to the unnecessary area is erroneously detected as an edge of the original. This can be suppressed. As a result, the size of the original can be determined satisfactorily.

  The transparent member 9 is provided at a position facing the portion near the left rear corner of the contact glass 7 when the document cover 5 is closed. Thus, in the configuration in which the document is arranged so that the left rear corner of the document is aligned with the left rear corner of the contact glass 7, the document is supported on the contact glass 7 from the read image acquired by the pre-reading of the reading process. Or whether it is supported on the transparent member 9.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, as shown in FIG. 10, a specific image 51 such as a character string may be formed on the outer periphery of the boundary frame 41 on the lower surface of the document cover 5. In this case, in the reading process, the CPU 34 of the ASIC 31 controls the moving mechanism 35 to move the reading device 11 as the moving destination, the first position E instead of the first position A, and the third position instead of the third position C. Position H. The first position E is a position spaced a predetermined distance from the right end of the boundary frame 41 to the right so that all the specific images 51 are included. The CPU 34 sets the reading range in the main scanning direction by the reading device 11 to a range in which at least the specific image 51 is included. The third position H is a position that is a predetermined distance to the right of the home position and is spaced a predetermined distance to the left so that all the specific images 51 are included from the left end of the boundary frame 41. When the CPU 34 controls the moving mechanism 35 to move the reading device 11 between the third position H and the home position, the specific image 51 is not read even if no document is set. Further, an image including the specific image 51 is stored in the ROM 32 as a target image as the target image of the boundary frame 41. By forming the specific image 51 such as a character string on the outer periphery of the boundary frame 41, it can be determined more clearly whether or not the boundary frame 41 is included in the image read by the reading process.

  In this embodiment, it is determined whether the entire target image including the boundary frame 41 (or the specific image 51) is included in the read image obtained by pre-reading. It may be judged whether it is not included at all. A case including the specific image 51 of FIGS. 10 to 13 will be described as an example. Even when the specific image 51 is not included, the image can be similarly implemented using an image formed by the boundary frame 41 instead of the specific image 51. Note that the ROM 32 includes values relating to the fifth position F and the sixth position G in addition to the first position E, the second position B (explained as the second position I in FIG. 13), the third position H, and the fourth position D. Also remember. The CPU 34 controls the moving mechanism 35 to move the reading device 11 to the first position E, and then moves the first CIS 12 of the reading device 11 while moving the reading device 11 from the first position E to the fifth position F. In use, pre-reading is performed to read the region from the first position E to the fifth position F. The fifth position F is a position spaced a predetermined distance from the right end of the boundary frame 41 to the left side. That is, the area including the target image at the right end of the specific image 51 is pre-read.

  When the specific image 51 is not included in the read image obtained by the pre-reading, as shown in FIG. 11, the original is supported on the contact glass 7 and the entire specific image 51 is viewed from the contact glass 7 side. This is the case when it is hidden in the document. In this case, the CPU 34 controls the moving mechanism 35 to move the reading device 11 from the fifth position F to the third position H. The third position H is a position at a predetermined distance (for example, 30 mm) from the left end of the contact glass 7 to the right side. Then, the CPU 34 controls the moving mechanism 35 to control the reading device 11 while moving the reading device 11 from the third position H to the home position HP, and to change the region from the third position H to the home position. Perform pre-reading. When the pre-reading is completed, the CPU 34 detects the edge of the read image by analyzing the read image, and determines the size specified from the detected edge as the size at the time of the main reading.

  When the specific image 51 is included in the read image obtained by the pre-reading, as shown in FIG. 12, a document is supported on the contact glass 7, and a part of the specific image 51 is seen from the contact glass 7 side. This is the case when it is hidden by the document or when the document is supported on the transparent member 9 as shown in FIG. At this time, the CPU 34 controls the moving device 35 to control the reading device 11 while moving the reading device 11 from the fifth position F to the sixth position G, and from the fifth position F to the sixth position G. Pre-reading is performed to read up to the area. The sixth position G is a position spaced a predetermined distance to the left of the right edge of the minimum size document that can be read by the image reading apparatus 2.

  In the read image obtained by pre-reading, when the rear part of the specific image 51 is interrupted in the middle compared to the front part, the document is supported on the contact glass 7 as shown in FIG. Thus, it can be considered that a part of the specific image 51 is hidden in the document when viewed from the contact glass 7 side. In this case, the CPU 34 controls the moving mechanism 35 to move the reading device 11 from the sixth position G to the third position H. Then, the CPU 34 controls the moving mechanism 35 to control the reading device 11 while moving the reading device 11 from the third position H to the home position HP, and to change the region from the third position H to the home position. Perform pre-reading. At this time, the reading range in the main scanning direction by the reading device 11 is set to a length range obtained by adding a predetermined amount α to the dimension in the main scanning direction of the minimum size document that can be read by the image reading apparatus 2. When the pre-reading is completed, the CPU 34 detects the edge of the read image by analyzing the read image, and determines the size specified from the detected edge as the size at the time of the main reading.

  When the length of the rear portion of the specific image 51 is the same as the length of the front portion in the read image obtained by pre-reading, the document is supported on the transparent member 9 as shown in FIG. It is considered that. In this case, the CPU 34 controls the moving device 35 to control the reading device 11 while moving the reading device 11 from the sixth position G to the second position I, and from the sixth position G to the second position I. Pre-reading is performed to read up to the area. At this time, the reading range in the main scanning direction by the reading device 11 is set to a range that does not deviate from the boundary frame 41 in the main scanning direction. The second position I is a position at a predetermined distance (for example, 30 mm) from the left end of the boundary frame 41 to the right side, that is, the same position as the second position B of the present embodiment. When the pre-reading is completed, the CPU 34 detects the edge of the read image by analyzing the read image, and determines the size specified from the detected edge as the size at the time of the main reading.

  Since the reading range in the main scanning direction at the time of edge detection can be determined from the specific image 51 (boundary frame 41) included in the read image at the time of pre-reading, dust other than the document is mistakenly part of the document. It is possible to prevent the determination, and it is possible to perform the main reading process with an appropriate document size.

  In the above-described embodiment, the first CIS 12 of the reading device 11 is used at the time of actual reading of the document supported on the contact glass 7, and the reading device 11 of the reading device 11 is used at the time of actual reading of the document supported on the transparent member 9. The second CIS 13 was used. However, the present invention is not limited to this, and the second CIS 13 is omitted from the reading device 11, and smoothing is set to be weaker with respect to the image read by the first CIS 12 during the main reading of the document supported on the contact glass 7. When the image processing using the first filter is executed and the original document supported on the transparent member 9 is read, the image read by the first CIS 12 is set to be smoother than the first filter. Image processing using two filters may be executed. By executing such image processing, an image of the original can be read satisfactorily regardless of whether the original is supported on the contact glass 7 or the transparent member 9.

  In the above-described embodiment, the reading element group 14 of the first CIS 12 and the reading element group 17 of the second CIS 13 are arranged at the same position in the vertical direction, and the focal length by the rod-shaped lens array 19 is determined by the rod-shaped lens array 16. The same rod-shaped lens array is used for the first CIS 12 and the second CIS 13, and the reading element group 17 of the second CIS 13 is larger than the reading element group 14 of the first CIS 12 by the thickness of the transparent member 9. You may arrange | position in a high position.

  Furthermore, in the above-described embodiment, the case where the CPU 34 executes each process has been described. However, the ASIC 31 may include a plurality of CPUs, and the plurality of CPUs may cooperate to execute each process.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

2: Image reading device 5: Document cover 7: Contact glass 9: Transparent member 11: Reading device 14, 17: Reading element group 16, 19: Rod-shaped lens array 34: CPU
35: Movement mechanism 41: Boundary frame 51: Specific image

Claims (8)

A support portion having a document support surface for supporting the document;
A document cover provided to be openable and closable with respect to the document support surface;
A reading sensor provided on a side opposite to the document cover with respect to the document support surface and having a plurality of reading elements arranged in a main scanning direction;
A moving mechanism for moving the reading sensor;
A control unit,
The control unit moves an image of a document supported on the document support surface while moving the reading sensor in a sub-scanning direction extending along the document support surface perpendicular to the main scanning direction by the moving mechanism. Execute the reading process to make the reading sensor read,
The image reading apparatus, wherein a part of the document cover is made of a transparent member that transmits light in a thickness direction of the document cover. The image reading apparatus according to claim 1,
The reading sensor includes a first rod-shaped lens array and a second rod-shaped lens array having a focal length different from that of the first rod-shaped lens array,
The plurality of reading elements are arranged corresponding to the first rod-shaped lens array and arranged along the main scanning direction, and are arranged corresponding to the second rod-shaped lens array. A second reading element group arranged along the scanning direction,
The controller is
Prior to the execution of the reading process, a pre-reading process for causing the reading sensor to read an image of a predetermined area is executed while the reading mechanism is moved in the sub-scanning direction by the moving mechanism. A range wider than a range constituted by a boundary frame between a member and a portion other than the transparent member in the document cover,
Determining whether the image obtained by the pre-read processing includes a target image representing the boundary frame;
If it is determined that at least part of the target image is not included, the reading process causes the reading sensor to read an image of the document using the first reading element group,
An image reading apparatus that, when determining that the entire target image is included, causes the reading sensor to read an image of a document using a second reading element group in the reading process. The image reading apparatus according to claim 1, wherein:
The controller is
Prior to the execution of the reading process, a pre-reading process for causing the reading sensor to read an image of a predetermined area is executed while moving the reading sensor in the sub-scanning direction by the moving mechanism, and the predetermined area is the transparent member And a range wider than a range constituted by a boundary frame between the original cover and a portion other than the transparent member,
Determining whether the image obtained by the pre-read processing includes a target image representing the boundary frame;
If it is determined that at least a part of the target image is not included, a first image process using a first filter is performed on the image read in the reading process;
An image reading apparatus that executes second image processing using a second filter different from the first filter on an image read by the reading processing when it is determined that the entire target image is included. The image reading apparatus according to any one of claims 1 to 3,
The controller is
Prior to the execution of the reading process, a pre-reading process for causing the reading sensor to read an image of a predetermined area is executed while the reading mechanism is moved in the sub-scanning direction by the moving mechanism. A range wider than a range constituted by a boundary frame between a member and a portion other than the transparent member in the document cover,
Determining whether the image obtained by the pre-read processing includes a target image representing the boundary frame;
When it is determined that at least a part of the target image is not included, edge detection is performed to detect an edge of the document supported on the document support surface when the reading process is performed, and the edge of the document support surface is The document size is determined with the document width between the edges detected by the edge detection, and image data is generated based on the determined document size.
An image reading device that generates image data by cutting out an image inside the boundary frame when it is determined that the entire target image is included. The image reading apparatus according to claim 4,
The document support surface is set with a document support region that is an area along one edge of the document support surface in the sub-scanning direction and that supports the document.
The controller is
The reading mechanism moves the reading sensor to a position between the boundary frame and the edge, and detects an edge of the document from an image read while moving the reading sensor from the position toward the one end edge. An image reading apparatus. An image reading apparatus according to any one of claims 2 to 5,
The controller is
When it is determined that the target image is not included, when the reading process is executed, the moving sensor moves the reading sensor in the sub-scanning direction by the maximum distance so that an image of the document supported on the document supporting surface is obtained. Let the reading sensor read,
When it is determined that a part or all of the target image is included, the reading sensor is moved by the moving mechanism based on the position of the boundary frame represented by the target image in the sub-scanning direction when the reading process is executed. An image reading apparatus that causes the reading sensor to read an image of a document supported on the document support surface by moving a distance smaller than the maximum distance. The image reading apparatus according to any one of claims 1 to 6,
The document support surface is provided with a document support region in which the document is supported on the basis of an angle formed by an edge of one side of the document support surface in the sub-scanning direction and an edge perpendicular to the edge. ,
The image reading apparatus, wherein the transparent member is provided such that the center of the transparent member is closer to the corner than the center of the document cover. An image reading apparatus according to any one of claims 1 to 7,
An image reading apparatus, wherein the document cover is provided with a specific image at a peripheral edge outside a boundary frame between the transparent member and a portion of the document cover other than the transparent member.

Images