JP4888159B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus including an automatic document feeder (ADF) and a flat bed scanner (FBS).

  2. Description of the Related Art Conventionally, there has been known an image reading apparatus including an automatic document conveyance mechanism (hereinafter also simply referred to as “ADF”) and a flat bed scanner (hereinafter also simply referred to as “FBS”). The image reading apparatus includes a contact type line sensor such as a CIS (Contact Image Sensor) that reciprocates with respect to the platen glass. The document placed on the platen glass is optically read by the line sensor while the line sensor is moved along the platen glass. The document placed on the document tray of the ADF is optically read by a line sensor arranged at a predetermined reading position in the process of being conveyed along the conveyance path.

  It is known that when a halftone original such as a printed matter is read by the above-described line sensor, interference fringes called so-called moire are generated. Patent Document 1 discloses a configuration in which the line sensor is moved up and down to change the relative distance between the reading surface of the document placed on the platen glass and the line sensor in order to reduce the occurrence of moire.

  In the image reading apparatus described in Patent Document 1, an image reading unit including a CCD (Charge Coupled Device) and a rod lens array is mounted on a carriage. The image reading unit includes an actuator in which an egg-shaped disc cam is provided on the rotation shaft of the stepping motor. The image reading unit is mounted on the carriage with the peripheral surface of the disc cam in contact with the carriage. When the stepping motor is driven, the disc cam rotates and the distance between the image reading unit and the carriage is changed. As a result, the distance between the image reading unit and the platen glass is changed.

  Japanese Patent Application Laid-Open No. 2004-228561 measures an MTF (Modulation Transfer Function) value based on an image signal obtained by reading a focus detection chart, and changes the height of the image reading unit based on the MTF value. Is described. This image reading apparatus has two reading modes, a photographic original mode and a printed original mode. In the photo original mode, the image reading unit is arranged at a height at which the MTF value is maximized, and the original on the platen glass is read. In the printed document mode, the image reading unit is arranged at a height at which the MTF value is about 40% of the maximum value, and the document on the platen glass is read.

  Patent Document 2 describes that the relative distance is adjusted by changing the height of the line sensor, as in the image reading apparatus disclosed in Patent Document 1. The image reading apparatus described in Patent Document 2 includes a rail whose longitudinal direction is the direction in which the CIS moves. The CIS moves on the rail along the rail. The rail has an oval cross section in a direction perpendicular to the longitudinal direction (axial direction), and is rotated around the axial direction by operation of a lever to function as a disc cam. As the rail rotates, the CIS approaches or moves away from the platen glass. That is, the relative distance between the CIS and the reading surface of the original on the platen glass is changed by operating the lever. Patent Document 2 describes that a jack is provided between the support plate on which the CIS is placed and the CIS, and the CIS is moved up and down by the jack by operating a knob.

  Patent Document 3 describes the use of a moire prevention plate when reading a document in which moire occurs. The moire prevention plate is a transparent member on which a document is placed, and is disposed on the platen glass. A document on which moiré is generated is placed on a moire prevention plate disposed on a platen glass. As described above, the moire prevention plate is interposed between the platen glass and the original, thereby separating the distance between the line sensor and the original. Since the original is read by the line sensor while being out of focus, the occurrence of moire is reduced.

JP 2002-171391 A JP 2002-262032 A JP-A-9-65078

  Incidentally, in the image reading apparatus described in Patent Document 1, it is necessary to provide a drive mechanism that moves the line sensor up and down in order to change the relative distance between the reading surface of the document and the line sensor. This is the same when the configuration disclosed in Patent Document 2 is used, and there is a problem that the configuration of the apparatus becomes complicated and the manufacturing cost increases.

  The image reading apparatus described in Patent Document 3 requires a troublesome operation for the user such as disposing a moire prevention plate in order to change the relative distance between the reading surface of the document and the line sensor.

  Note that a configuration that can change the relative distance between the reading surface of the document conveyed by the ADF and the line sensor is not disclosed in any patent document. Further, neither patent document discloses a configuration in which the relative distance can be changed during document reading.

  The present invention has been made in view of such a problem, and does not add a drive mechanism for changing the relative distance between a line sensor that reads a conveyed document and the reading surface of the document while reading the document. An object of the present invention is to provide an image reading apparatus that can read an image of a document by changing the focus of a line sensor.

(1) An image reading apparatus according to the present invention includes a first transmission member provided in a path through which a document is conveyed, a second transmission member on which the document is placed, and a first light transmission member or the first transmission member from a light source. (2) A contact type line sensor that irradiates a document through a transmissive member and reads reflected light from the document for each main scanning line, and moves the line sensor so as to face the first transmissive member or the second transmissive member. Based on an image of a document obtained by pre-scanning the document conveyed by the line sensor disposed opposite to the first transmission member by the driving unit, or based on a user setting. The line sensor reading area of the original is divided into a plurality of areas, and the line sensor is moved by controlling the driving of the driving section, and the line sensor is inclined with respect to the plane on which the line sensor moves. A first control unit configured to change a relative distance between the reading surface of the first transmitting member and the line sensor; The first control unit changes the relative distance for each of the divided areas in the main scan of the conveyed document by the line sensor.

  The image reading apparatus of the present invention is configured to be able to read a document to be conveyed and a document placed on the second transmission member. The line sensor is disposed at a position facing the first transmission member by the driving unit when reading the conveyed document. In the process of transporting the original along the path, the line sensor irradiates light through the first transmission member, and the reflected light is read for each main scanning line. The line sensor is moved along the second transmission member by the drive unit when reading the document placed on the second transmission member. In the process, the original is irradiated with light through the second transmission member by the line sensor, and the reflected light is read for each main scanning line. The drive unit described above is driven by the first control unit. By this driving, the relative distance between the reading surface of the original on the first transmitting member and the line sensor is changed. That is, the relative distance is changed using a drive source of the line sensor.

The reading area of the line sensor in the document is divided into a plurality of areas by the dividing section. The reading area is divided based on an original image obtained by prescanning the original or user settings. In the main scan of the conveyed document, the relative distance between the reading surface of the document and the line sensor on the first transmission member is changed according to the sectioned area by driving the drive unit that moves the line sensor. For this reason, it is possible to blur and read, for example, a partial area of the conveyed document without providing a drive source different from the drive unit. In addition, since the reading surface of the first transmission member is inclined with respect to the plane on which the line sensor moves, the relative distance can be easily changed without newly adding a member for changing the relative distance. The

(2) The reading surface of the first transmission member may be separated from the plane on which the line sensor moves on the downstream side of the path along the document transport direction on the upstream side.

  With the above configuration, the document being conveyed is pressed against the first transmission member. For this reason, the relative distance is prevented from changing due to the floating of the document with respect to the first transmitting member.

(3) The image reading apparatus according to the present invention includes a first transmissive member provided in a path through which a document is conveyed, a second transmissive member on which the document is placed, a light source to the first transmissive member or the first transmissive member. (2) A contact type line sensor that irradiates a document through a transmissive member and reads reflected light from the document for each main scanning line, and moves the line sensor so as to face the first transmissive member or the second transmissive member. Based on an image of a document obtained by pre-scanning the document conveyed by the line sensor disposed opposite to the first transmission member by the driving unit, or based on a user setting. a partition portion for partitioning the reading area of the line sensor into a plurality of regions in the document that, a first control unit for moving the line sensor controls the drive of the drive unit, the thickness in the direction of the line sensor is moved Changes to a stepped shape or a wedge shape, the line sensor is interposed between the line sensor and the first transmission member in a state of facing the first transmission member, and is in contact with the moved line sensor. A first spacer that changes a relative distance between the first transmission member and the line sensor, and the first control unit performs the sectioning in the main scan of the conveyed document by the line sensor. The relative distance is changed for each area.

The image reading apparatus of the present invention is configured to be able to read a document to be conveyed and a document placed on the second transmission member. The line sensor is disposed at a position facing the first transmission member by the driving unit when reading the conveyed document. In the process of transporting the original along the path, the line sensor irradiates light through the first transmission member, and the reflected light is read for each main scanning line. The line sensor is moved along the second transmission member by the drive unit when reading the document placed on the second transmission member. In the process, the original is irradiated with light through the second transmission member by the line sensor, and the reflected light is read for each main scanning line. The drive unit described above is driven by the first control unit. By this driving, the relative distance between the reading surface of the original on the first transmitting member and the line sensor is changed. That is, the relative distance is changed using a drive source of the line sensor.

The reading area of the line sensor in the document is divided into a plurality of areas by the dividing section. The reading area is divided based on an original image obtained by prescanning the original or user settings. In the main scan of the conveyed document, the relative distance between the reading surface of the document and the line sensor on the first transmission member is changed according to the sectioned area by driving the drive unit that moves the line sensor. For this reason, it is possible to blur and read, for example, a partial area of the conveyed document without providing a drive source different from the drive unit. Further, since the first spacer is provided, the line sensor is moved toward or away from the first transmission member by being moved by the driving unit.

(4) a first receiving unit that receives a selection of a first mode that divides the reading area based on the result of the pre-scan or a second mode that divides the reading area based on a user setting; Divides the reading area on the basis of the image of the original obtained by the prescan by causing the line sensor to execute the prescan on the condition that the selection of the first mode is accepted by the first accepting unit. The reading area may be partitioned based on the user setting without causing the line sensor to execute the pre-scan on the condition that the selection of the second mode is received by the first receiving unit.

  In the image reading apparatus of the present invention, selection of the first mode or the second mode is accepted by the first accepting unit. In the first mode, the reading area is divided based on the result of the pre-scan. In the second mode, the reading area is partitioned based on user settings. When the selection of the first mode is accepted, prescanning of the conveyed document is executed by the line sensor. Then, based on the image of the original obtained by the pre-scan, a reading area of the original read by the main scan is partitioned. As a result, for example, an image of a document obtained by pre-scanning is analyzed to partition a reading area, or a document image obtained by pre-scanning is displayed and the reading area is partitioned based on a user operation. It becomes possible. When the selection of the second mode is accepted, the reading area of the document read in the main scan is partitioned based on the user setting. For example, by setting the same reading area for a plurality of documents, the plurality of documents are read under the same conditions. In the second mode, the document is not pre-scanned.

(5) The image reading apparatus according to the present invention includes a correction unit that performs shading correction on the image of the document obtained by the main scan based on white reference data, and the above-described image according to the reading region of the image of the document that is subjected to shading correction A changing unit that changes the white reference data.

  A document image obtained by the main scan is subjected to shading correction for each reading area based on the white reference data. Since the relative distance is changed in the main scan of the conveyed document, the amount of reflected light from the document to the line sensor changes during reading of the document. By changing the white reference data in accordance with the reading area, it is possible to obtain a document image having a constant quality corresponding to the change in the relative distance.

(6) The partition section partitions the reading area into a first area and a second area, and the first control section has the relative distance substantially coincident with the focal length of the line sensor. The line sensor may be made to read the first area, and the line sensor may be made to read the second area in a state where the relative distance is different from the focal length.

  The document reading area is divided into a first area and a second area by the dividing section. The line sensor is disposed at a position where the relative distance substantially matches the focal length of the line sensor. In this state, the first area of the conveyed document is read by the line sensor through the first transmission member. The line sensor is disposed at a position where the relative distance is different from the focal length of the line sensor. In this state, the second area of the document to be conveyed is read by the line sensor through the first transmission member. The first area of the original is read with the line sensor being in focus, and the second area of the original is read with the line sensor being out of focus. As a result, an image of a document in which the first area is clear and the second area is blurred is obtained.

(7) a first display for displaying a first setting screen for inputting designation information designating the first area or the second area, and a second receiving input of the designation information for the first setting screen. A receiving unit, and the partitioning unit may partition the reading area based on designation information received by the second receiving unit.

  In the image reading apparatus, a first setting screen is displayed. The first setting screen is for inputting designation information for designating the first area or the second area. The user inputs the designation information according to the first setting screen. Based on the input designation information, the document reading area is divided into a first area and a second area. For this reason, the user can arbitrarily designate the first area or the second area in the image reading apparatus and blur and read a partial area of the document.

(8) A first receiving unit that receives designation information for designating the first area or the second area from a terminal device connected to be communicable with the own apparatus is provided, and the partition unit is provided by the first receiving unit. The reading area may be partitioned based on the received designation information.

  The image reading device is communicably connected to the terminal device. The designation information transmitted from the terminal device is received by the first receiving unit. The document reading area in the main scan is divided into a first area and a second area based on the designation information. For this reason, the user can arbitrarily designate the first area and the second area on the terminal device, and can read a part of the document in a blurred manner.

(9) A second display unit that displays an image of the document obtained by the pre-scan and an input of designation information that specifies the first area or the second area with respect to the displayed image of the document. A third receiving unit, and the partitioning unit may partition the reading area based on designation information received by the third receiving unit.

  In the image reading apparatus, the image of the prescanned document is displayed on the second display unit. Input of designation information for designating an area for the displayed document image is accepted by the third accepting unit. The document reading area in the main scan is divided into a first area and a second area based on the designation information. For this reason, the user can easily specify a region to be blurred of the document by looking at the pre-scan image displayed on the image reading apparatus.

(10) A transfer unit that transfers an image of the document obtained by the pre-scan to a terminal device connected to be communicable with the own device, and the first area or the second for the transferred document image. A second receiving unit that receives designation information for designating an area from the terminal device, and the partitioning unit may partition the reading area based on the designation information received by the second receiving unit.

  The image reading device is communicably connected to the terminal device. The document image obtained by the pre-scan by the line sensor is transferred to the terminal device. For example, in a terminal device, an image of a document is displayed on a monitor. Designation information is generated by the terminal device based on the user's operation input when viewing the document image displayed on the monitor. This designation information is transmitted to the image reading apparatus and received by the second receiving unit. The document reading area in the main scan is divided into a first area and a second area based on the designation information.

(11) a first storage unit that stores the designation information designating the first area or the second area, and a fourth reception unit that receives selection of the designation information stored in the first storage unit, The partition unit may partition the reading area based on the designation information on condition that the selection of the designation information is accepted by the fourth accepting unit.

  Selection of the designation information stored in the first storage unit is received by the fourth reception unit. The document reading area is divided into a first area and a second area based on the designation information. For this reason, when the same first area and second area are designated for a plurality of originals and the original is read, it is not necessary to input designation information for each original.

(12) A third display unit that displays a second setting screen for inputting characters or figures, a fifth receiving unit that accepts input of characters or figures on the second setting screen, and the pre-scan. A detection unit that detects a character or a figure received by the fifth reception unit from an image of the document, and the partition unit defines an area including the character or the graphic detected by the detection unit as the second region. It may be divided into sections.

  In the image reading apparatus, a second setting screen is displayed. The second setting screen is for inputting characters or figures. The user inputs characters or figures according to the second setting screen. The input character or figure is received by the fifth receiving unit. The detection unit detects this character or figure from the image of the document obtained by prescanning. A region including the detected character or graphic is partitioned into a second region by the partition unit. For this reason, when a user inputs a character or a figure, it becomes possible to blur and read the area | region containing the character or a figure.

(13) A second transfer unit that transfers an image of the document obtained by the pre-scan to a terminal device connected to be communicable with the own device, and is transmitted from the terminal device in response to the transfer of the image of the document. A third receiving unit that receives a character or a graphic; and a detection unit that detects a character or a graphic received by the third receiving unit from an image of a document obtained by the pre-scan. An area including characters or graphics detected by the detection unit may be partitioned into the second area.

  The image reading device is communicably connected to the terminal device. The document image obtained by the pre-scan by the line sensor is transferred to the terminal device. For example, in a terminal device, an image of a document is displayed on a monitor. Character or graphic information is generated by the terminal device based on the operation input of the user who viewed the image of the document displayed on the monitor. This character or graphic is transmitted to the image reading apparatus and received by the third receiving unit. The document reading area in the main scan is divided into a first area and a second area based on the characters or graphics.

(14) A second storage unit that stores the character or graphic, and a sixth reception unit that receives selection of the character or graphic stored in the second storage unit, wherein the detection unit receives the sixth reception On the condition that the selection of the character or graphic is accepted by the section, the character or graphic may be detected from the document image obtained by the pre-scan.

  The sixth accepting unit accepts selection of characters or graphics stored in the second storing unit. In the document reading area, an area including the characters or graphics is divided into second areas. For this reason, when the same first area and second area are specified for a plurality of originals and the original is read, it is not necessary to input characters or figures for each original.

(15) In the image reading apparatus of the present invention, a second control unit that causes the line sensor to perform an operation of reading a test document on which a predetermined pattern is recorded at a plurality of positions having different relative distances through the first transmission member. A calculation unit that obtains an MTF (Modulation Transfer Function) value for each of the plurality of positions based on the image signal of the test document obtained by the operation, and a first area of the document that is conveyed in the main scan. Based on the respective MTF values, a reading position where the line sensor is arranged by the driving unit when reading and a reading position where the line sensor is arranged by the driving unit when reading the second area of the document are determined. And a determination unit that performs.

  The test document is, for example, a black and white pattern recorded thereon. The test document is read by the line sensor through the first transmission member. The line sensor is moved with respect to the first transmission member by the driving unit. The position of the line sensor with respect to the first transmission member is changed, and the test document is read by the line sensor. Thereby, an image signal of the test document is obtained for each position where the line sensor is arranged. Based on these image signals, the MTF value is obtained for each position of the line sensor. Based on each MTF value, a reading position where the line sensor is arranged when reading the first area and a reading position where the line sensor is arranged when reading the second area are determined. As a result, the relative distance is changed with respect to the first region and the second region.

(16) The determining unit may determine a position where the MTF value is maximized as a reading position of the line sensor that reads the first area.

  With the configuration described above, the first area of the document is subjected to the main scan with the line sensor in focus. For this reason, an image of a document with a clear first area can be obtained.

(17) The determination unit may determine a position where the MTF value is equal to or less than a predetermined percentage of the maximum value as a reading position of the line sensor that reads the second region.

  By setting the predetermined percentage to an appropriate value, an image of a document in which the second area is suitably blurred can be obtained by the main scan.

(18) It has a reading surface read by the line sensor as a lightness reference of the line sensor, and the reading surface includes a reference member inclined with respect to the moving surface of the line sensor, and the first control unit Controls the driving of the drive unit, and the relative distance between the reading surface of the reference member and the line sensor is the relative distance between the reading surface of the first transmitting member and the line sensor at the time of reading by the line sensor. The line sensor may be moved to the same position so that the line sensor reads the reading surface of the reference member .

With the above configuration, the distance between the reference member and the reading surface can be matched. It is possible to prevent a light amount difference from occurring between the light amount when the line sensor reads the original through the first transmission member and the light amount when the line sensor reads the reference member. In addition, since the reading surface of the reference member is inclined with respect to the plane on which the line sensor moves, the relative distance can be increased without adding a new member for changing the relative distance between the line sensor and the reference member. Easily changed.

(19) The image reading apparatus of the present invention includes a reference member that is read by the line sensor as a lightness reference of the line sensor, and a thickness that changes in a stepped shape or a wedge shape in a direction in which the line sensor moves. Is interposed between the line sensor and the reference member in a state of being opposed to the reference member, and is in contact with the moved line sensor to change a relative distance between the reference member and the line sensor. When, with the said first control unit controls the drive of the drive unit, reading the relative distance between the reading surface and the line sensor of the reference member of the first transmission member when the reading of the line sensor The line sensor may be moved to a position where the relative distance between the surface and the line sensor is the same, and the line sensor may be caused to read the reading surface of the reference member .

With the above configuration, the distance between the reference member and the reading surface can be matched. It is possible to prevent a light amount difference from occurring between the light amount when the line sensor reads the original through the first transmission member and the light amount when the line sensor reads the reference member. Further, since the second spacer is provided, the line sensor is moved toward or away from the reference member by being moved by the driving unit.

  According to the present invention, in the main scan of the conveyed document, the relative distance between the reading surface of the document and the line sensor in the first transmission member depends on the partitioned area by driving the drive unit that moves the line sensor. Changed. For this reason, for example, it is possible to blur and read a partial area of a document to be conveyed without providing a drive source different from the drive unit.

  Embodiments of the present invention will be described below with reference to the drawings as appropriate. In addition, this embodiment is only an example of this invention, and it cannot be overemphasized that embodiment can be changed suitably in the range which does not change the summary of this invention.

[First Embodiment]
FIG. 1 is a perspective view showing an external configuration of the scanner 10 according to the first embodiment of the present invention, and shows a state in which a document cover 17 is opened.

  A scanner 10 (an example of an image reading apparatus according to the present invention) has a scanner function for reading an image of a document. In the present embodiment, the present invention will be described using the scanner 10 having only the scanner function as an example. However, the image reading apparatus according to the present invention is not limited to the scanner 10. The image reading apparatus according to the present invention may be realized as a copier, a facsimile machine, or a multi function device having a plurality of functions as long as it has a scanner function.

  As shown in FIG. 1, the scanner 10 includes a document table 11. The document table 11 functions as a flat bed scanner (FBS). The document table 11 has a substantially rectangular parallelepiped housing 15. A line sensor 40 (see FIGS. 2 and 3) is provided inside the housing 15. In the scanner 10, an image of a document is read by the line sensor 40.

  As shown in FIG. 1, the scanner 10 includes a document cover 17. The document cover 17 is for bringing a document placed on a second glass 20 (an example of a second transmission member of the present invention), which will be described later, into close contact with the second glass 20. The document cover 17 is provided so as to be openable and closable with respect to the document table 11. Specifically, the document cover 17 is rotatably connected to the document table 11 via a hinge (not shown) on the back side of the document table 11. The document cover 17 includes an automatic document feeder (ADF) 28.

  FIG. 2 is a schematic cross-sectional view showing a part of the conveyance path 12 in the scanner 10 according to the first embodiment of the present invention.

  As shown in FIGS. 1 and 2, the ADF 28 conveys the document placed on the document tray 22 to the paper discharge tray 23 along the conveyance path 12. That is, the conveyance path 12 is a path along which the document is conveyed. In FIG. 2, the original tray 22 and a part of the conveyance path 12 on the original tray 22 side are omitted. The document tray 22 (see FIG. 1) and the paper discharge tray 23 (see FIG. 2) are provided on the document cover 17 so that the document tray 22 is in two upper and lower stages with the document tray 22 on the upper side. The conveyance path 12 is provided inside the ADF 28 so as to have a substantially U shape in the horizontal direction when viewed in a vertical cross section. The conveyance path 12 is continuously formed as a passage having a predetermined width through which a document can pass by members, guide plates, guide ribs, and the like that constitute the ADF 28 body. The document tray 22 and the paper discharge tray 23 are connected by the transport path 12.

  A plurality of rollers 73 (see FIG. 4) for conveying the document are disposed in the conveyance path 12. Although not shown in the figure, the roller 73 includes a so-called pickup roller, separation roller, transport roller, and paper discharge roller. A driving force is transmitted to each of these rollers 73 from a single motor 72 (see FIG. 4). The rotational force of each roller 73 is transmitted to the document, and the document is transported along the transport path 12 from the document tray 22 toward the paper discharge tray 23. As shown in FIG. 2, a first glass 18 (an example of a first transmission member of the present invention) is provided in the middle of the conveyance path 12. When the document cover 17 is closed, the document placed on the document tray 22 is transported along the transport path 12 by the ADF 28 and passes over the first glass 18. At that time, the image of the original is read by the line sensor 40 standing under the first glass 18. The original is further conveyed and discharged to the paper discharge tray 23.

  As shown in FIG. 1, a first glass 18 and a second glass 20 are disposed on the top surface of the upper cover 16 that constitutes a part of the housing 15. The first glass 18 (see FIGS. 1 and 2) is a transmission plate made of a transparent glass plate, an acrylic plate, or the like. When an original is placed on the original tray 22 and an instruction to start reading the original is issued, the line sensor 40 is disposed at a position facing the first glass 18 (see, for example, FIG. 5). With this line sensor 40, the image of the document conveyed on the first glass 18 is read by the line sensor 40 through the first glass 18.

  The second glass 20 (see FIGS. 1 and 2) is for placing a document when the document table 11 is used as an FBS. The second glass 20 is a transmission plate made of a transparent glass plate, an acrylic plate, or the like. When an original is placed on the second glass 20 and an instruction to start reading the original is issued, the line sensor 40 is moved in the sub-scanning direction of the original (the direction indicated by the arrow 38) so as to face the second glass 20. . In the process, the image of the document on the second glass 20 is read by the line sensor 40 through the second glass 20.

  A partition member 51 (see FIGS. 1 and 2) is provided between the first glass 18 and the second glass 20 on the top surface of the document table 11. Similarly to the first glass 18 and the second glass 20, the partition member 51 is a long member extending in the depth direction of the scanner 10 (direction indicated by the arrow 39 in FIG. 3). As shown in FIG. 2, the partition member 51 has a substantially L-shaped cross section in the width direction (the direction indicated by the arrow 38) of the scanner 10. One end (the right side in FIG. 2) of the first glass 18 in the short direction is supported by the partition member 51. The partition member 51 is used as a document positioning reference when placing the document on the second glass 20. The partition member 51 has a display indicating the center position, the positions of both ends of various document sizes such as A4 (Japanese Industrial Standards A row No. 4) size and B5 (Japanese Industrial Standards B row No. 5) size. The document is placed on the second glass 20 with the center position marked on the partition member 51 as a reference.

  The upper surfaces of the first glass 18 and the second glass 20 are exposed when the document cover 17 is opened (see FIG. 1). By closing the document cover 17, the entire upper surface of the document table 11 including the first glass 18 and the second glass 20 is covered with the document cover 17. A document retainer 19 (see FIG. 1) that covers the second glass 20 is provided on the lower surface of the document cover 17. The document retainer 19 is composed of a sponge, a white plate and the like in order to retain the document placed on the second glass 20. When the document cover 17 is closed, the document placed on the second glass 20 is pressed toward the second glass 20 by the document cover 17 via the document presser 19. In addition, since the first glass 18 is provided on the upper surface of the document table 11, the document cover 17 is closed to constitute a part of the transport path 12. For this reason, the ADF 28 is used in a state where the document cover 17 is closed with respect to the document table 11.

  FIG. 3 is a plan view showing the internal configuration of the document table 11. FIG. 3 shows a state in which the upper cover 16 is removed.

  As shown in FIG. 3, an image reading unit 14 is provided inside the housing 15 of the document table 11. The image reading unit 14 reads a document through the first glass 18 or the second glass 20. The image reading unit 14 includes a line sensor 40, a carriage 41, a guide shaft 42, and a belt driving mechanism 43.

  The line sensor 40 (see FIGS. 2 and 3) is for irradiating light on a document from a light source and reading reflected light from the document for each main scanning line. As the line sensor 40, a reading device having a short focal length is used. In the present embodiment, the line sensor 40 is a so-called contact image sensor (CIS). Although not shown in the drawing, the line sensor 40 includes a light source, a lens, and a light receiving element. The line sensor 40 irradiates the original with light from the light source through the first glass 18 or the second glass 20. In other words, the line sensor 40 irradiates the original conveyed by the ADF 28 with light through the first glass 18, or irradiates the original placed on the second glass 20 with light through the second glass 20. The line sensor 40 condenses the reflected light from the document on a light receiving element by a lens and converts it into an electrical signal (image signal). Thereby, an image of a document is obtained. The light receiving elements of the line sensor 40 are arranged side by side in the main scanning direction (direction indicated by the arrow 39) of the document, for example, in units of chips. The light source and lens of the line sensor 40 are arranged in the same direction as the light receiving element.

  The carriage 41 has the line sensor 40 mounted on the upper side thereof (see FIG. 2). The line sensor 40 is mounted on a spring receiving portion 64 of the carriage 41 via a coil spring 74. Inside the housing 15, a guide shaft 42 is installed over the width direction (left and right direction in FIG. 3). The carriage 41 is fitted with the guide shaft 42. The carriage 41 is driven by the belt drive mechanism 43 and moves on the guide shaft 42 in the direction indicated by the arrow 38. Rollers 30 (see FIGS. 2 and 3) are provided on the upper surface of the carriage 41 corresponding to both ends of the carriage 41 in the longitudinal direction. Each roller 30 is pivotally supported by the carriage 41 so as to be able to roll in the moving direction of the carriage 41 (the direction indicated by the arrow 38). Each roller 30 protrudes upward from the upper surface of the carriage 41 evenly. A guide member 34 (see FIG. 2) is provided on the upper surface side of the housing 15. The guide member 34 is an elongated flat plate member that extends in the moving direction of the carriage 40. The guide member 34 is disposed along a trajectory along which the roller 30 moves. Each roller 30 is in contact with the back surface of the guide member 34. Thereby, a certain gap is formed between the upper surface of the line sensor 40 and the back surface of the second glass 20. The focal point of the line sensor 40 coincides with the upper surface of the second glass 20 due to this constant gap. As the rollers 30 roll, the carriage 41 is smoothly moved along the guide member 34. Since the line sensor 40 is mounted on the carriage 41, the line sensor 40 is moved to face the first glass 18 or the second glass 20.

  The belt drive mechanism 43 (see FIG. 3) includes a drive belt 44, a drive pulley 45, and a driven pulley 46. As shown in FIG. 3, the drive pulley 45 and the driven pulley 46 are respectively provided at both ends of the housing 15 in the width direction. The drive belt 44 is an endless ring having teeth on the inside, and is stretched between the drive pulley 45 and the driven pulley 46. A driving force is transmitted to the shaft of the driving pulley 45 from a CR (carriage) motor 65 (corresponding to the driving unit of the present invention: see FIG. 4). The drive belt 44 is rotated by the rotation of the drive pulley 45, and the line sensor 40 mounted on the carriage 41 is moved to face the first glass 18 or the second glass 20. For example, a stepping motor is used as the CR motor 65. The position of the line sensor 40 in the width direction of the scanner 10 (the direction indicated by the arrow 39) is monitored by the control unit 55 (see FIG. 4) by measuring the number of steps of the CR motor 65.

  The document conveyed by the ADF 28 is moved along the first glass 18. An image of the original is read through the first glass 18 by the line sensor 40 disposed below the first glass 18. For this reason, on the upper surface of the first glass 18, a document reading surface 25 (see FIG. 2) by the line sensor 40 is formed. Here, the reading surface 25 is a reading area of the line sensor 40 in the first glass 18. That is, an image of a document passing on the first glass 18 is read by the line sensor 40 on the reading surface 25 on the upper surface of the first glass 18. As shown in FIG. 2, the reading surface 25 is inclined with respect to a plane on which the line sensor 40 moves (a plane parallel to the paper surface of FIG. 3: hereinafter also referred to as “moving plane”). In the present embodiment, the reading surface 25 is separated from the moving surface on the downstream side (the right side in FIG. 2) from the upstream side (the left side in FIG. 2) in the transport direction of the document in the transport path 12 (see FIG. 2). . For this reason, the original document being conveyed is pressed against the first glass 18. As a result, it is possible to prevent the relative distance between the upper surface of the line sensor 40 and the reading surface 25 from being changed due to the floating of the document with respect to the first glass 18.

  The line sensor 40 is moved to face the first glass 18 by the driving force applied from the CR motor 65. The driving of the CR motor 65 is controlled by a control unit 55 (see FIG. 4) described later. The control unit 55 includes a partition unit, a first control unit, a first reception unit, a change unit, a second reception unit, a first reception unit, a third reception unit, a first transfer unit, a second reception unit, a first reception unit, and a second reception unit. 4 reception part, 5th reception part, detection part, 2nd transfer part, 3rd reception part, 6th reception part, 2nd control part, calculating part, and determination part are corresponded. As described above, the reading surface 25 of the first glass 18 is inclined with respect to the moving surface. The controller 55 drives the CR motor 65 to move the line sensor 40 (carriage 41) in the direction indicated by the arrow 38. In accordance with the position of the line sensor 40, the position of the reading surface 25 moves in the short direction of the first glass 18 (see FIG. 5). As a result, the control unit 55 changes the relative distance between the reading surface 25 of the original on the first glass 18 and the line sensor 40 (hereinafter also referred to as “first relative distance”) (D1 in FIG. 5). , D2). Since the first relative distance is changed using the CR motor 65 that is the drive source of the line sensor 40, the first relative distance can be changed with a simple configuration. That is, the first relative distance can be easily changed without newly adding a member for changing the first relative distance. By changing the first relative distance, the focus of the line sensor 40 can be changed with respect to the reading surface 25 of the document, and the document conveyed by the ADF 28 can be read.

  Note that the inclination angle of the reading surface 25 with respect to the moving surface is not particularly limited. However, the inclination angle is preferably set based on the MTF (Modulation Transfer Function) characteristic of the line sensor 40. When the inclination angle is increased, the change in the first relative distance with respect to the movement of the line sensor 40 is increased. Conversely, when the inclination angle is reduced, the change in the first relative distance with respect to the movement of the line sensor 40 is reduced. Therefore, when using a reading device with a very narrow focus range as the line sensor 40, it is preferable to set the tilt angle to be small. Conversely, when a reading device with a wide focus range is used as the line sensor 40, the tilt angle may be set larger.

  Further, the reading surface 25 may be separated from the moving surface on the upstream side with respect to the downstream side in the transport direction of the document in the transport path 12. However, in order to prevent the document from floating with respect to the reading surface 25, it is preferable that the reading surface 25 is separated from the moving surface on the downstream side of the document conveying direction upstream as shown in FIG.

  As shown in FIG. 2, a platen 49 is provided above the first glass 18. The surface of the platen 49 facing the first glass 18 extends along the first glass 18 in the depth direction of the scanner 10 (the direction indicated by the arrow 39 in FIG. 3). The platen 49 is attached to a member (not shown) constituting the ADF 28 via a coil spring 35. Although not shown in the figure, convex portions projecting toward the first glass 18 are provided at both ends of the platen 49 in the longitudinal direction. By this convex portion, when the document cover 17 is closed, the first glass 18 and the platen 49 are arranged to face each other with a predetermined interval (see FIG. 2). The predetermined interval is set slightly longer than the thickness of the document. For this reason, the document is smoothly conveyed along the first glass 18 without being restricted by the platen 49.

  As shown in FIGS. 1 and 2, a reference member 37 is provided on the opposite side of the second glass 20 across the first glass 18. The reference member 37 is provided on the back surface of the upper cover 16. The reference member 37 is an image that is read by the line sensor 40 as a lightness reference of the line sensor 40. The reference member 37 includes a first light amount adjustment value 101, a second light amount adjustment value 102, first white reference data 90 (an example of white reference data according to the present invention), and second white reference data 91 (main book) shown in FIG. It is used to obtain an example of white reference data of the invention. The acquisition of the first light amount adjustment value 101, the second light amount adjustment value 102, the first white reference data 90, and the second white reference data 91 will be described in detail later.

  The reference member 37 is a thin-film strip-like member having substantially the same length as the line sensor 40 in the main scanning direction of the line sensor 40, and the surface facing the line sensor 40 is white. The reference member 37 is attached to the back surface of the inclined portion 48 formed on the upper cover 16. The inclined portion 48 is inclined at the same inclination angle as the first glass 18 with respect to the moving surface. For this reason, the reading surface 27 of the reference member 37 is inclined with respect to the moving surface at substantially the same angle as the reading surface 25 of the first glass 18. Here, the reading surface 27 does not indicate the entire back surface of the reference member 37 but means a surface of the reference member 37 that is read by the line sensor 40. As shown in FIG. 2, the first glass 18 and the reference member 37 are inclined in line symmetry with respect to the width direction of the scanner 10.

  The controller 55 drives the CR motor 65 to move the line sensor 40 (carriage 41), whereby the relative distance between the reading surface 27 of the reference member 37 and the line sensor 40 (hereinafter referred to as “second relative distance”). Change). Since the second relative distance is changed using the CR motor 65 that is a drive source of the line sensor 40, the second relative distance can be changed with a simple configuration. That is, the second relative distance can be easily changed without newly adding a member for changing the second relative distance between the line sensor 40 and the reference member 37. By changing the second relative distance, the focus of the line sensor 40 can be changed and the reading surface 27 can be read.

  As shown in FIG. 1, an operation panel 13 (corresponding to a first display unit, a second display unit, and a third display unit of the present invention) is provided on the front upper portion of the scanner 10. The operation panel 13 includes a liquid crystal display for displaying various information, input keys for a user to input information, a touch panel, and the like. The scanner 10 operates based on an operation input from the operation panel 13. A user's operation input for instructing to start reading a document placed on the second glass 20 or a document placed on the document tray 22 is performed from the operation panel 13. The scanner 10 is operated not only by an instruction from the operation panel 13 but also by an instruction connected to the terminal device 140 (see FIG. 4) and transmitted from the terminal device 140 via a scanner driver or the like.

  FIG. 4 is a block diagram illustrating a configuration example of the control unit 55 of the scanner 10.

  The control unit 55 controls the overall operation of the scanner 10. As shown in FIG. 4, the control unit 55 mainly includes a CPU (Central Processing Unit) 56, a ROM (Read Only Memory) 57, a RAM (Random Access Memory) 58, and an EEPROM (Electrically Erasable and Programmable ROM) 59. It is configured as a microcomputer. The control unit 55 includes a motor control circuit 124, a motor control circuit 125, a reading control circuit 126, an image processing control circuit 127, a panel control circuit 128, a sensor input circuit 129, and a LAN I / F (Local Area) via the bus 60. Network Interface) 61.

  The ROM 57 stores a control program for controlling various operations of the scanner 10 by the CPU 56. The RAM 58 is a storage area or a work area for temporarily storing various data used when the control program is executed by the CPU 56. As shown in FIG. 4, the RAM 58 stores data such as a first light amount adjustment value 101, a second light amount adjustment value 102, first white reference data 90, and second white reference data 91. These data will be described in detail later.

  The RAM 58 stores the reading mode information 24 (see FIG. 4). The reading mode information 24 is information indicating a document reading mode set by the control unit 55 based on an operation input from the operation panel 13 or an instruction from the terminal device 140. Reading of the original conveyed by the ADF 28 is performed based on the reading mode information 24. In the present embodiment, the control unit 55 sets either the normal mode or the blur mode. The normal mode is a reading mode in which the control unit 55 reads the document through the first glass 18 with the line sensor 40 in a state where the first relative distance is substantially matched with the focal length of the line sensor 40. In other words, the normal mode is a reading mode in which the original is read in a state where the line sensor 40 is focused on the reading surface 25 of the original on the first glass 18. In the blur mode, a partial area (first area described later) of the original is read with the focus of the line sensor 40 aligned with the reading surface 25, and the original is read with the focus of the line sensor 40 largely shifted from the reading surface 25. This is a reading mode for reading the remaining area (second area described later).

  The EEPROM 59 stores various settings, flags, and the like that should be retained even after the power is turned off. In the present embodiment, the EEPROM 59 stores the first position 31 and the second position 32. These pieces of information are information indicating the reading position in the sub-scanning direction where the line sensor 40 is arranged with respect to the reading mode information 24 set in the RAM 58. The first position 31 is a reading position where the line sensor 40 is in focus with respect to the reading surface 25. The second position 32 is a reading position where the focus of the line sensor 40 is greatly deviated from the reading surface 25.

  FIG. 5 is a schematic cross-sectional view illustrating the reading position of the line sensor 40, where (A) shows a reading position corresponding to the first position 31, and (B) shows a reading position corresponding to the second position 32.

  The reading mode information 24 in the RAM 58 is set to the normal mode, and the document conveyed by the ADF 28 is read. In the normal mode, the image of the conveyed document is read on the reading surface 25 in a state where the line sensor 40 is disposed at the reading position corresponding to the first position 31 (see FIG. 5A). Since the first position 31 is a position where the line sensor 40 is in focus with respect to the reading surface 25, a clear document image with high resolution can be obtained. That is, the normal mode is a reading mode suitable for faithfully reproducing a document.

  The reading mode information 24 in the RAM 58 is set to the blur mode, and the document conveyed by the ADF 28 is read. In the blurring mode, the image of the first region in the conveyed document is read in a state where the line sensor 40 is arranged at the reading position corresponding to the first position 31 (see FIG. 5A). In addition, the image of the second region is read from the document in a state where the line sensor 40 is disposed at the reading position corresponding to the second position 32 (see FIG. 5B). As a result, an image of the document blurred before the first area is clear and the second area cannot be identified is obtained. The method for determining the first position 31 and the second position 32 and the document reading operation in each reading mode will be described in detail later.

  As shown in FIG. 4, a drive circuit 71 is connected to the motor control circuit 124. A drive circuit 66 is connected to the motor control circuit 125. A line sensor 40 and an AFE (Analog Front End) circuit 78 are connected to the reading control circuit 126. The image processing control circuit 127 is connected to an image processing circuit 79 (corresponding to the correction unit of the present invention). The operation panel 13 is connected to the panel control circuit 128. A document detection sensor 36 is connected to the sensor input circuit 129. A terminal device 140 is connected to the LAN I / F 61 via a LAN (Local Area Network) 108.

  The drive circuit 71 drives the motor 72. The motor 72 is configured to be rotatable in both forward and reverse directions. The drive circuit 71 receives the output signal from the motor control circuit 124 and generates a pulse signal for rotating the motor 72. Based on this pulse signal, the motor 72 is rotated. The motor 72 applies a driving force to the roller 73 and is a driving source in the ADF 28. The control unit 55 counts the number of pulses of the pulse signal generated by the drive circuit 71. Thereby, the number of steps of the motor 72 is counted. The counted number of steps is temporarily stored in the RAM 58. Based on the number of steps, the position of the document in the transport path 12 of the ADF 28 is determined.

  The image reading unit 14 executes a document reading operation and outputs an image of the document as an image signal. The image reading unit 14 includes a line sensor 40, a carriage 41, a CR motor 65, and a drive circuit 66. The drive circuit 66 supplies a drive signal to the CR motor 65 based on the phase excitation signal or the like input from the motor control circuit 125. The CR motor 65 is a stepping motor, for example. The CR motor 65 rotates in response to the drive signal. Thereby, the carriage 41 is reciprocated. The drive circuit 66 also adjusts the operating current for turning on the light source of the line sensor 40. The control unit 55 controls the image reading unit 14 based on a control program stored in the ROM 57, so that the first light amount adjustment value 101, the second light amount adjustment value 102, the first white light in addition to the document reading operation. The reference data 90 and the second white reference data 91 are acquired.

  The line sensor 40 irradiates light on a document placed on the second glass 20 or a document conveyed on the first glass 18 by the ADF 28 from a light source, and reads the document image line by line. The read image is output from the line sensor 40 to the AFE circuit 78 as an image signal (image data).

  The line sensor 40 is moved by the carriage 41 so as to face the second glass 20 on which the document is placed. In this process, the line sensor 40 repeats the operation of irradiating the original from the light source through the second glass 20 and outputting the reflected light from the original as an image signal of one line. Thereby, an image of the entire document placed on the second glass 20 is obtained.

  The line sensor 40 is moved by the carriage 41 and disposed at a position facing the first glass 18. In this state, the document placed on the document tray 22 is transported along the transport path 12 by the ADF 28. In this process, the line sensor 40 repeats the operation of irradiating the original from the light source through the first glass 18 and outputting the reflected light from the original as an image signal of one line. As a result, an image of the entire document passing over the first glass 18 is obtained.

  The AFE circuit 78 samples and holds analog image signals output from the line sensor 40, digitally converts the sampled and held image signals, and serializes them. The digital conversion is a process of converting an analog image signal output from the line sensor 40 into a digital signal composed of a digital code having a predetermined number of bits. This digital conversion is performed by an analog / digital converter. The analog image signal input to the AFE circuit 78 is output to the image processing circuit 79 as a digital image signal of, for example, 8 bits (256 gradations: 0 to 255).

  The image processing circuit 79 performs image processing on the image signal output from the AFE circuit 78. The image processing circuit 79 performs shading correction, sharpening (enhancement) processing, color space conversion, binarization processing, and the like on the image signal output from the AFE circuit 78. In other words, the image processing circuit 79 performs shading correction on the image of the document obtained by the main scan of the document conveyed by the ADF 28. By performing the shading correction by the image processing circuit 79, the variation between the light receiving elements of the line sensor 40 and the light source is corrected. This shading correction is performed based on the first white reference data 90 or the second white reference data 91. The document image signal read in a state where the line sensor 40 is arranged at the reading position corresponding to the first position 31 (see FIG. 5A) is subjected to shading correction based on the first white reference data 90. The image signal of the document read in a state where the line sensor 40 is disposed at the reading position corresponding to the second position 32 (see FIG. 5B) is subjected to shading correction based on the second white reference data 91. Since other image processing performed by the image processing circuit 79 is not directly related to the present invention, detailed description thereof is omitted.

  The panel control circuit 128 generates a signal for controlling the liquid crystal display of the operation panel 13 based on an instruction from the control unit 55. The panel control circuit 128 includes an interface circuit that transmits information input from the operation panel 13 to the control unit 55.

  The sensor input circuit 129 removes noise from the output signal (sensor signal) from the document detection sensor 36 (see FIG. 4) and outputs the signal to a predetermined output destination. The document detection sensor 36 detects the presence or absence of a document in the document tray 22 (see FIG. 1), and is arranged at a predetermined position on the document tray 22. The document detection sensor 36 is a mechanical sensor in the present embodiment.

  The document detection sensor 36 includes a transmission type optical sensor (photo interrupter) and a shielding member pivotally supported. In the photo interrupter, a light emitting unit that emits light and a light receiving unit that receives light emitted from the light emitting unit are arranged to face each other. The document detection sensor 36 outputs a sensor signal based on the fact that light is received by the light receiving portion of the photo interrupter. In a state where the shielding member is in a position that blocks the optical path between the light emitting unit and the light receiving unit, the light emitted from the light emitting unit is blocked by the shielding member and is not received by the light receiving unit. Since the shielding member is detected, the document detection sensor 36 is in the OFF state. When a document is placed on the document tray 22, the document contacts the shielding member and the shielding member is rotated. As a result, the shielding member leaves the position where the optical path of the photo interrupter is blocked. For this reason, the light emitted from the light emitting unit is received by the light receiving unit. That is, the document detection sensor 36 is turned on. In this way, the state of the document detection sensor 36 is changed by placing the document on the document tray 22. Therefore, the control unit 55 can determine the presence / absence of a document in the document tray 22 based on the sensor signal output from the sensor input circuit 129.

  The LAN I / F 61 is an interface that connects the LAN 108 and the scanner 10 in a communicable manner. A terminal device 140 is connected to the LAN 108. The terminal device 140 is a so-called personal computer. The terminal device 140 includes a keyboard and mouse for a user to input information, a liquid crystal display on which various types of information are displayed, and the like. The scanner 10 is communicably connected to the terminal device 140 via the LAN 108.

  The processing for setting the reading position (first position 31 and second position 32) of the line sensor 40 is performed at a predetermined timing such as when the scanner 10 is turned on or when a predetermined operation input is performed by the user. Executed. Further, the process for setting the reading position may be executed when a predetermined time elapses from the previous reading position setting process or when the power is turned on after the predetermined time elapses.

  6 and 7 are flowcharts showing the procedure of the reading position setting process performed when the scanner 10 is powered on. Note that the processing of the scanner 10 described based on the following flowchart is performed according to a command issued by the control unit 55 based on a control program stored in the ROM 57.

  The control unit 55 determines whether the power of the scanner 10 is turned on based on whether a predetermined operation input is performed by the user from the operation panel 13 (S1). When the control unit 55 determines that the power is not turned on (S1: NO), the scanner 10 enters a standby state. When determining that the power of the scanner 10 is turned on (S1: YES), the control unit 55 determines whether or not the first position 31 and the second position 32 are stored in the EEPROM 59 (S2). When the control unit 55 determines that both the first position 31 and the second position 32 are stored (S2: YES), the process ends.

  When it is determined that neither the first position 31 nor the second position 32 is stored (S2: NO), the control unit 55 determines whether the first position 31 is stored (S3). . When the control unit 55 determines that the first position 31 is not stored (S3: NO), it notifies the user that the first test document 98 (an example of the test document of the present invention) is to be placed on the document tray 22. (S4). For example, the control unit 55 causes the operation panel 13 to display a message such as “Please set the first test document on the document tray”.

  FIG. 8 is a schematic diagram showing an example of the first test document 98. FIG. 9 is a schematic cross-sectional view showing how the reading position of the line sensor 40 is changed.

  As shown in FIG. 8, the first test document 98 is obtained by recording a white and black stripe pattern (an example of a predetermined pattern of the present invention) at a pitch of 150 lpi (line per inch). The first test document 98 is placed on the document tray 22 so that the pattern arrangement direction (the left-right direction in FIG. 8) substantially matches the depth direction of the scanner 10 (the direction indicated by the arrow 39). Note that the pitch of the black and white pattern is not limited to 150 lpi, and may be changed as appropriate according to the performance of the line sensor 40 and the like.

  The control unit 55 determines whether or not the first test document 98 is placed on the document tray 22 based on the sensor signal output from the document detection sensor 36 (see FIG. 4) (S5). When the control unit 55 determines that the first test document 98 is not placed on the document tray 22 (S5: NO), the process of step S4 is continued. When determining that the first test document 98 is placed on the document tray 22 (S5: YES), the control unit 55 controls the CR motor 65 (see FIG. 4) to move the line sensor 40 to the reading start position. (S6). The reading start position is the left end of the readable range (see FIG. 2) of the line sensor 40 with respect to the first glass 18 (see FIG. 9A). The control unit 55 controls the motor 72 (see FIG. 4) to convey the first test original 98 along the conveyance path 12 by a predetermined amount. As a result, the black and white pattern recorded on the first test document 98 is arranged above the first glass 18. Then, the control unit 55 reads the first test document 98 through the first glass 18 by the line sensor 40 (S7). In the process of step S7, the image of the first test document 98 is read for one line or several lines. The control unit 55 obtains the MTF value based on the image signal of the first test document 98 obtained by the process of step S7 and the arithmetic expression of expression 1 shown below (S8).

  In the arithmetic expression of Expression 1, Imax is the maximum density of the input image. In other words, Imax is the theoretical value of the highest density of the image recorded on the first test document 98. Imin is the minimum density of the input image. In other words, Imin is a theoretical value of the minimum density of the image recorded on the first test document 98. Dmax is the maximum density of the output image. Dmin is the minimum density of the output image.

  Following the processing of step S8, the control unit 55 determines whether or not the first set number (11 in this embodiment) of MTF values has been acquired (S9). When the control unit 55 determines that eleven MTF values have not been acquired (S9: NO), the control unit 55 controls the CR motor 65 to move the line sensor 40 to the reading end position (see FIG. 9C) side. Move by one distance (S10). By performing the processing of step S10, the reading position of the line sensor 40 is changed. In other words, the first relative distance between the line sensor 40 and the reading surface 25 of the first test document 98 is changed. The reading surface 25 of the first glass 18 is separated from the moving surface of the line sensor 40 on the downstream side from the upstream side in the document transport direction. For this reason, the first relative distance increases as the line sensor 40 is moved. As shown in FIG. 9C, the reading end position is the right end of the readable range (see FIG. 2) of the line sensor 40 with respect to the first glass 18.

  After the reading position of the line sensor 40 is changed by the process of step S10, the processes of steps S7 and S8 are performed in a state where the line sensor 40 is disposed at the reading position. The control unit 55 repeats the processes of step S7, step S8, and step S10 in order, so that the first test original 98 is first placed at a plurality of positions (11 positions in the present embodiment) having different first relative distances. The line sensor 40 is caused to execute an operation of reading through the glass 18. And the control part 55 calculates | requires MTF value for every 11 positions based on the image signal of the 1st test original 98 obtained by this operation | movement.

  FIG. 10 is a diagram showing the MTF characteristics obtained by reading the first test document 98.

  In FIG. 10, the horizontal axis changes by moving the line sensor 40 by driving the CR motor 65, that is, the relative distance between the reading surface 25 of the first test original 98 on the first glass 18 and the line sensor 40, that is, The first relative distance is shown. The vertical axis represents the MTF value. FIG. 10 shows MTF values corresponding to 11 reading positions having different first relative distances. “1” on the horizontal axis corresponds to the first relative distance between the line sensor 40 and the reading surface 25 of the first test document 98 when the line sensor 40 is disposed at the reading start position (see FIG. 9A). is doing. “6” on the horizontal axis corresponds to the first relative distance between the line sensor 40 and the reading surface 25 of the first test document 98 in a state where the line sensor 40 is disposed at the reading end position (see FIG. 9C). is doing.

  As shown in FIG. 6, when the control unit 55 determines that 11 MTF values have been acquired (S9: YES), the reading position where the MTF value is maximum is set to the first position 31 (see FIG. 4). Determine (S11). Specifically, the control unit 55 obtains an MTF curve 68 (see FIG. 10) from eleven MTF values obtained by repeating the processes of steps S7 to S10. Since the method for obtaining the MTF curve 68 from the MTF value is well known, the description of the method is omitted here. The control unit 55 determines the position of the line sensor 40 having the maximum MTF value from the MTF curve 68 as the first position 31. Here, the MTF value corresponding to the first relative distance whose horizontal axis is represented by “3.5” in the MTF characteristic of FIG. 10 is the maximum. Therefore, the control unit 55 reads the reading position (FIG. 5A and FIG. 9) of the line sensor 40 at the first relative distance D1 (see FIG. 5A) whose horizontal axis is represented by “3.5”. B) is determined as the first position 31. The first position 31 is information indicating a reading position for the normal mode. The first position 31 is also information indicating a reading position where the line sensor 40 is arranged by the CR motor 65 when reading the first area of the document conveyed in the main scan in the blur mode. The first position 31 is stored in the EEPROM 59. As described above, the control unit 55 determines the position where the MTF value is maximized as the reading position of the line sensor 40 that reads the first region.

  In the present embodiment, the first distance is set so that the reading position of the line sensor 40 is changed to 11 positions between the reading start position and the reading end position in order to acquire 11 MTF values. Is set. The first distance is set based on the distance from the reading start position to the reading end position and the first set number. Note that the number of MTF values to be acquired is not limited to 11, and the first distance may be changed to acquire, for example, 5 MTF values. Alternatively, the first position 31 determined in step 11 may be set as a temporary reading position, and the MTF value may be obtained by moving the line sensor 40 more finely than the first distance before and after the temporary reading position. Thereby, the 1st position 31 can be calculated | required more correctly. Further, the first position 31 may be determined without obtaining the MTF curve 68. That is, the control unit 55 may determine the maximum value among the 11 MTF values and determine the reading position of the line sensor 40 corresponding to the MTF value as the first position 31.

  When it is determined that the first position 31 is stored in the EEPROM 59 (S3: YES), or when the process of step S11 is performed, the control unit 55 determines whether or not the second position 32 is stored in the EEPROM 59. Judgment is made (S13). When the control unit 55 determines that the second position 32 is stored (S13: YES), the process ends. When the control unit 55 determines that the second position 32 is not stored (S13: NO), it notifies that the second test document 99 (an example of the test document of the present invention) is to be placed on the document tray 22. (S14). For example, the control unit 55 causes the operation panel 13 to display a message such as “Please set the second test document on the document tray”.

  FIG. 11 is a schematic diagram showing an example of the second test document 99.

  As shown in FIG. 11, the second test document 99 is obtained by recording white and black stripe patterns at a pitch of 50 lpi. The second test document 99 is placed on the document tray 22 such that the pattern arrangement direction (the left-right direction in FIG. 11) substantially matches the depth direction of the scanner 10 (the direction indicated by the arrow 39). The pitch of the black and white stripe pattern is not limited to 50 lpi, and may be appropriately changed according to the performance of the line sensor 40 and the like.

  The control unit 55 determines whether or not the second test document 99 is placed on the document tray 22 based on the sensor signal output from the document detection sensor 36 (see FIG. 4) (S15). When the control unit 55 determines that the second test document 99 is not placed (S15: NO), the process of step S14 is continued. When the control unit 55 determines that the second test document 99 is placed on the document tray 22 (S15: YES), the control unit 55 moves the line sensor 40 to the reading start position in the same manner as the process of step S6 (S16). ). The controller 55 controls the motor 72 to convey the second test document 99 along the conveyance path 12 by a predetermined amount. As a result, the black and white pattern recorded on the second test document 99 is arranged above the first glass 18. Then, the control unit 55 reads the second test document 99 through the first glass 18 by the line sensor 40 (S17). The control unit 55 obtains the MTF value based on the image signal of the second test document 99 obtained by the process of step S17 and the arithmetic expression of the above expression 1 (S18).

  The control unit 55 determines whether or not the second set number (11 in the present embodiment) of MTF values has been acquired (S19). When the control unit 55 determines that eleven MTF values have not been acquired (S19: NO), the control unit 55 controls the CR motor 65 to move the line sensor 40 to the reading end position (see FIG. 9C) side. Move by two distances (S20). As a result, the first relative distance between the line sensor 40 and the reading surface 25 of the second test document 99 is changed. The second distance is a distance set based on the distance from the reading start position to the reading end position and the second set number. Therefore, for example, if the second set number is changed, it is changed accordingly.

  After the reading position of the line sensor 40 is changed by the process of step S20, the processes of step S17 and step S18 are performed in a state where the line sensor 40 is arranged at the reading position. The control unit 55 reads the second test document 99 through the first glass 18 at a plurality of (here, 11 positions) having different first relative distances by repeating the processes of step S17, step S18, and step S20. The operation is executed by the line sensor 40. And the control part 55 calculates | requires an MTF value for every 11 positions based on the image signal of the 2nd test original 99 obtained by this operation | movement.

  FIG. 12 is a diagram showing the MTF characteristics obtained by reading the second test document 99.

  In FIG. 12, the horizontal axis changes by moving the line sensor 40 by driving the CR motor 65, that is, the relative distance between the reading surface 25 of the second test document 99 on the first glass 18 and the line sensor 40. The first relative distance is shown. The vertical axis represents the MTF value. FIG. 12 shows MTF values corresponding to 11 reading positions having different first relative distances.

  When it is determined that 11 MTF values have been acquired (S19: YES), the controller 55 obtains the maximum MTF value (S21). Specifically, the control unit 55 obtains the MTF curve 63 (see FIG. 12) from the 11 MTF values obtained by repeating the processes of steps S17 to S20. Then, the control unit 55 determines the peak of the MTF curve 63 and obtains the maximum value of the MTF value. Here, as shown in FIG. 12, the MTF value corresponding to the first relative distance whose horizontal axis is represented by “3.5” is the maximum value.

  The control unit 55 determines the position where the MTF value is 20% or less (predetermined% in the present invention) of the maximum value obtained in step S21 as the second position 32 (S22). Specifically, the control unit 55 obtains an MTF value that is 20% of the maximum value obtained in step S21. For example, when the maximum value is 1, the MTF value is 0.2. The control unit 55 determines the position of the line sensor 40 corresponding to the obtained MTF value (here, 0.2) and determines the second position 32. The second position 32 is information indicating a reading position where the line sensor 40 is arranged by the CR motor 65 when reading the second area of the document conveyed in the main scan in the blur mode. The second position 32 is stored in the EEPROM 59. Thus, the control unit 55 determines the position where the MTF value is 20% or less of the maximum value as the reading position of the line sensor 40 that reads the second region.

  In addition, instead of the two test originals of the first test original 98 and the second test original 99, one sheet on which two patterns for determining each of the first position 31 and the second position 32 are recorded. The first position 31 and the second position 32 may be determined using the test document. In this case, a test document in which two patterns are recorded side by side in the depth direction of the scanner 10 (the direction indicated by the arrow 39) is used. The control unit 55 reads the image of each pattern individually by changing the reading range of the test document in the main scanning direction. And the control part 55 determines the 1st position 31 and the 2nd position 32 based on each acquired image. In this case, the time and effort for the user to place the test document on the document tray 22 is reduced. Alternatively, a test document in which two patterns are recorded side by side in the document conveyance direction may be used. In this case, it is only necessary to individually read the image of each pattern by changing the pattern arranged on the first glass 18 by conveying the test document.

  In the present embodiment, the description has been given of the form in which two patterns are used to determine the first position 31 and the second position 32. However, the predetermined pattern used to determine these reading positions is one. It may be one. For example, the first position 31 and the second position 32 may be determined using only the first test document 98 without using the second test document 99. In this case, the control unit 55 determines the reading position corresponding to the maximum value of the MTF characteristic obtained by reading the pattern of the first test document 98 as the first position 31. Then, the control unit 55 determines the reading position corresponding to the MTF value that is, for example, 20% of the maximum value as the second position 32.

  FIG. 13 is a flowchart showing a procedure of processing performed in the scanner 10 when an instruction to start reading a document is issued in the state where the normal mode is set.

  The control unit 55 determines whether or not the normal mode is set based on the reading mode information 24 stored in the RAM 24 (S31). When the control unit 55 determines that the normal mode is not set, that is, the blur mode is set (S31: NO), the process returns to step S31. When it is determined that the normal mode is set (S31: YES), the control unit 55 determines whether or not a document is placed on the document tray 22 (S32). The determination in step S32 is made based on the sensor signal output from the document detection sensor 36. If the control unit 55 determines that no document is placed on the document tray 22 (S32: NO), the process returns to step S32.

  When it is determined that a document is placed on the document tray 22 (S32: YES), the control unit 55 determines whether or not a document reading start command has been issued (S33). Specifically, the control unit 55 receives from the terminal device 140 whether or not a predetermined operation input for instructing to start reading of the document has been performed on the operation panel 13 or a reading start command for instructing to start reading of the document. Determine whether or not. If the control unit 55 determines that there is no document reading start command (S33: NO), the process returns to step S33.

  When the control unit 55 determines that there is a reading start command (S33: YES), that is, when a predetermined operation input is performed from the operation panel 13 or a reading start command is received from the terminal device 140, the CR motor 65 is turned on. The line sensor 40 is driven to move to the reading position corresponding to the first position 31 with respect to the reference member 37 (see FIG. 2) (S34). In this reading position, the relative distance (second relative distance) between the line sensor 40 moved downward of the reference member 37 and the reading surface 25 of the reference member 37 is arranged at the reading position corresponding to the first position 31. This is a position that is substantially equal to the relative distance (first relative distance) between the line sensor 40 and the original reading surface 25 of the first glass 18. For example, the first relative distance and the second relative distance are stored in advance by associating the reading position of the line sensor 40 with respect to the first glass 18 and the corresponding reading position of the line sensor 40 with respect to the reference member 37. Can be substantially matched. In other words, the distance from the line sensor 40 to the reading surface 27 and the distance from the line sensor 40 to the reading surface 25 can be substantially matched. It is possible to prevent a light amount difference between the light emitted from the light source of the line sensor 40 to the reading surface 25 of the first glass 18 and the light emitted from the light source of the line sensor 40 to the reading surface 27 of the reference member 37. .

  The control unit 55 acquires the first light amount adjustment value 101 and the first white reference data 90 (see FIG. 4) (S35). The control unit 55 first irradiates the light source of the line sensor 40 toward the reading surface 27 of the reference member 37 with a small amount of light. Then, the control unit 55 gradually increases the light amount of the light source until the output from the light receiving element of the line sensor 40 reaches a predetermined value, and the light amount when the received light amount reaches the predetermined value is set to the first light amount adjustment value 101. Get as. That is, the first light amount adjustment value 101 is the light amount of the light source at which the light receiving amount of the light receiving element of the line sensor 40 becomes a predetermined value. The control unit 55 irradiates light from the light source of the line sensor 40 onto the reading surface 27 of the reference member 37 with the light amount of the first light amount adjustment value 101. Then, the control unit 55 acquires the first white reference data 90 by converting the reflected light from the reading surface 27 into an electric signal by the light receiving element of the line sensor 40. The first light amount adjustment value 101 and the first white reference data 90 acquired by the process of step S35 are stored in the RAM 58.

  The control unit 55 controls the rotation of the motor 72 and starts conveying the document placed on the document tray 22 (S36). The controller 55 reads the conveyed document by the line sensor 40 disposed at the reading position corresponding to the first position 31 (S37). Specifically, the control unit 55 controls the CR motor 65 with respect to the line sensor 40 arranged to face the reference member 37 in the process of step S34 and reads the reading position corresponding to the first position 31 (FIG. 5A). Move to). Then, the control unit 55 causes the line sensor 40 to perform an operation of reading a document conveyed on the first glass 18 at a reading position corresponding to the first position 31. As a result, the image of the document is read in a state where the focus of the line sensor 40 is substantially aligned with the reading surface 25 of the document on the first glass 18. Therefore, a clear original image can be obtained as compared with the case where the line sensor 40 is arranged at another position and the original is read. The document image (image signal) read in this way is processed by the AFE circuit 78. The image processing circuit 79 corrects the shading of the document image processed by the AFE circuit 78 based on the first white reference data 90 acquired in the process of step S35 (S38).

  In the normal mode, the document conveyed by the ADF 28 is read through the first glass 18 by the line sensor 40 arranged in the reading position corresponding to the first position 31 in the entire reading area. Since the original is read with the line sensor 40 in focus on the reading surface 25 of the first glass 18, a clear image of the original can be obtained.

  FIG. 14 is a schematic view illustrating the document reading area 47.

  In the blur mode, the control unit 55 divides the reading area of the document conveyed by the ADF 28 into first areas 93 and 97 and a second area 95. This division of the reading area is performed based on an image of a document obtained by pre-scanning a document conveyed to a line sensor 40 disposed opposite to the first glass 18, or based on user settings. The controller 55 changes the first relative distance by driving the CR motor 65 for each divided area in the main scan by the line sensor 40 of the conveyed document. The control unit 55 causes the line sensor 40 to read the first regions 93 and 97 in a state where the first relative distance is substantially matched with the focal length of the line sensor 40. That is, the control unit 55 causes the line sensor 40 to read the first regions 93 and 97 of the document that are conveyed in a state where the line sensor 40 is disposed at the reading position corresponding to the first position 31. The control unit 55 causes the line sensor 40 to read the second region 95 in a state where the first relative distance is different from the focal length of the line sensor 40. That is, the control unit 55 causes the line sensor 40 to read the second area 95 of the document that is conveyed in a state where the line sensor 40 is disposed at the reading position corresponding to the second position 32. By reading the document conveyed by the ADF 28 in the blur mode, an image of the document in which the first areas 93 and 97 are clear and the second area 95 is blurred can be obtained. Reading a document in this blur mode is suitable for reading a document on which personal information or confidential information is described, for example.

  In the example shown in FIG. 14, the document reading area 47 is divided into two areas, the first areas 93 and 97 and the second area 95, but the reading area 47 is divided into three or more areas. May be. In this case, in addition to the first position 31 and the second position 32, new reading position information may be set.

  FIG. 15 to FIG. 18 are flowcharts showing a procedure of processing performed in the scanner 10 when the operation panel 13 is instructed to start reading in a state where the blur mode is set. FIG. 19 is a schematic diagram illustrating an example of a setting screen displayed on the operation panel 13.

  As shown in FIG. 15, the control unit 55 determines whether or not the blur mode is set based on the reading mode information 24 stored in the RAM 58 (S41). If the control unit 55 determines that the blur mode is not set, that is, the normal mode is set (S41: NO), the process returns to step S41. When it is determined that the blur mode is set (S41: YES), the control unit 55 notifies the user that the selection of the first mode or the second mode is urged (S42). Specifically, the control unit 55 displays a message such as “Do you want to pre-scan?” On the operation panel 13. Here, the first mode is a mode in which the reading area is divided into the first area and the second area based on the result of the pre-scan and the user's designation. The second mode is a mode in which the reading area is divided into a first area and a second area based on user settings without performing pre-scanning.

  The control unit 55 determines whether the first mode or the second mode is selected based on the operation input from the operation panel 13 (S43). When the control unit 55 determines that no mode is selected (S43: NO), the process of step S42 is continued. When it is determined that the mode is selected (S43: YES), the controller 55 determines whether the selected mode is the first mode or the second mode (S44).

  When it is determined that the second mode has been selected (S44: second mode), the control unit 55 accepts the selection of the second mode and determines whether the designation information is stored in the EEPROM 59 (S45). Here, the designation information is information for designating the first area or the second area. The reading area of the document conveyed by the ADF 28 is divided into a first area and a second area based on this designation information. When it is determined that the designation information is stored (S45: YES), the control unit 55 informs the user that the selection information is to be input or not (S46). For example, the control unit 55 causes the operation panel 13 to display a message such as “Specified information is registered, but will you enter the specified information?”.

  Based on the presence / absence of a predetermined operation input from the operation panel 13, the control unit 55 determines whether or not the selection for the notification in step S46 has been made (S47). When the control unit 55 determines that no selection has been made (S47: NO), the process of step S46 is continued. When it is determined that the selection has been made (S47: YES), the control unit 55 determines whether the selection is an input of designated information (S48).

  When the control unit 55 determines that the selection is input of designation information (S48: YES), or when it is determined that the designation information is not stored in the EEPROM 59 (S45: NO), the control unit 55 is illustrated in FIG. The area setting screen 132 to be displayed (an example of the first setting screen in the present invention) is displayed (S49). The area setting screen 132 is a display screen for the user to input designation information.

  On the area setting screen 132, a document reading area 141, a cursor 123, a start position set button 130, an end position set button 131, a check box 117, and the like are displayed. The operation panel 13 on which the area setting screen 132 is displayed is a touch panel type. The user can input designation information by operating the cursor 123, the start position set button 130, and the end position set button 131 displayed on the area setting screen 132.

  For example, the designation information for designating the second area 95 (see FIG. 14) is input in the following manner. The start position set button 130 and the end position set button 131 are input keys for designating a line in the main scanning direction designated by the cursor 123 (one-dot chain line in FIG. 14). When the user operates the cursor 123, the start position set button 130, and the end position set button 131, the second area 95 is designated. The setting information for specifying the second area 95 is accepted when the check box 117 is checked. Note that FIG. 19A illustrates a reading area 141 in which two second areas are designated. In addition, the designation information may be input numerically by the user operating the numeric keypad of the operation panel 13 instead of the operation of the cursor 123. In the present embodiment, the second area is designated by the designation information, but the first area may be designated by the designation information.

  The control unit 55 determines whether designation information is input to the area setting screen 132 (S50). Specifically, the control unit 55 determines whether or not the designation information is set by operating the cursor 123, the start position set button 130, and the end position set button 131 and the check box 117 is checked. When the control unit 55 determines that the designation information has not been input (S50: NO), the process of step S49 is continued. When it is determined that the designation information has been input (S50: YES), the controller 55 accepts the input of the designation information and divides the document reading area into the first area and the second area based on the designation information (S51). ). Information indicating the partitioned first area and second area is temporarily stored in a predetermined area of the EEPROM 59. The document reading area is divided into a first area and a second area based on the input designation information. For this reason, the user can arbitrarily specify the first area or the second area in the scanner 10 to blur and read a partial area of the document.

  When the control unit 55 determines that the selection is not input of designation information (S48: NO), the control unit 55 displays the designation information stored in the EEPROM 59 (S52). The control unit 55 determines whether or not the stored designation information has been selected based on the presence / absence of a predetermined operation from the operation panel 13 (S53). When the control unit 55 determines that the designation information is not selected (S53: NO), the process of step S52 is continued. When it is determined that the stored designation information has been selected (S53: YES), the control unit 55 divides the document reading area into the first area and the second area based on the selected designation information (S54). . After the process of step S51 or the process of step S54 is performed, the control unit 55 executes the first process (see FIG. 20) (S55).

  FIG. 20 is a detailed flowchart of the first process.

  As shown in FIG. 20, the control unit 55 determines whether or not a document is placed on the document tray 22 (S551). The determination in step S551 is made based on the sensor signal output from the document detection sensor 36. When the control unit 55 determines that no document is placed on the document tray 22 (S551: NO), a standby state is entered. When it is determined that a document is placed on the document tray 22 (S551: YES), the control unit 55 determines whether a document reading start command has been issued (S552). When a predetermined operation input for instructing to start reading of a document is made from the operation panel 13 or when a predetermined command for instructing to start reading of a document is received from the terminal device 140, the control unit 55 determines YES in step S552. To be judged. Conversely, when a predetermined operation input is not performed from the operation panel 13 and a predetermined command is not received from the terminal device 140, the control unit 55 determines NO in step S552. When the control unit 55 determines that there is no reading start command (S552: NO), a standby state is entered.

  When it is determined that the reading start command has been issued (S552: YES), the control unit 55 drives the CR motor 65 to drive the line sensor 40 with respect to the reference member 37 (see FIG. 2), similarly to the process of step S34. The reading position corresponding to the first position 31 is moved (S553). The control unit 55 acquires the first light amount adjustment value 101 and the first white reference data 90 (see FIG. 4), similarly to the process of step S35 (S554). The first light amount adjustment value 101 and the first white reference data 90 acquired by the process of step S554 are stored in the RAM 58.

  The control unit 55 moves the line sensor 40 to the reading position corresponding to the second position 32 with respect to the reference member 37 (see FIG. 2) (S555). This reading position is arranged at a reading position where the second relative distance between the line sensor 40 moved downward of the reference member 37 by driving the CR motor 65 and the reading surface 25 of the reference member 37 corresponds to the second position 32. This position is substantially equal to the first relative distance between the line sensor 40 and the original reading surface 25 of the first glass 18.

  The control unit 55 acquires the second light amount adjustment value 102 and the second white reference data 91 (see FIG. 4) (S556). The process of step S556 is performed in the same manner as the process of step S35 except that the reading position of the line sensor 40 with respect to the reference member 37 is different. The second light amount adjustment value 102 and the second white reference data 91 acquired by the process of step S556 are stored in the RAM 58.

  The control unit 55 controls the motor 72 of the ADF 28 to start conveying the document placed on the document tray 22 (S557). The control unit 55 scans (main scan) the original conveyed by the ADF 28 by the line sensor 40 disposed at the reading position corresponding to the first position 31 (see FIG. 5A) (S558). Specifically, the control unit 55 controls the CR motor 65 to move the line sensor 40 disposed opposite to the reference member 37 to a reading position (see FIG. 5A) corresponding to the first position 31. Then, the control unit 55 causes the line sensor 40 to perform an operation of reading one line of the document conveyed on the first glass 18 at the reading position corresponding to the first position 31. As a result, one line of the image of the first area of the document is read in a state where the line sensor 40 is focused on the reading surface 25 of the document on the first glass 18. That is, the first area of the document is read clearly.

  The control unit 55 determines whether or not the second area of the document conveyed by the ADF 28 has reached the reading surface 25 (see FIG. 5B) on the first glass 18 (S559). The determination in step S559 is made based on the information on the first area and the second area set in the EEPROM 59 and the number of steps of the motor 72 (see FIG. 4) after the ADF 28 starts conveying the document. The When the control unit 55 determines that the second area has not reached (S559: NO), the control unit 55 determines whether or not the document has passed over the first glass 18 (S561). If the control unit 55 determines that the document has not passed over the first glass 18 (S561: NO), the process returns to S558. Thereby, the process of step S558 is repeated, and the image of the entire first area of the document is read.

  When the control unit 55 determines that the second area of the conveyed document has reached (S559: YES), the reading position corresponding to the second position 32 for the document conveyed by the ADF 28 (see FIG. 5B). A scan (main scan) is performed by the line sensor 40 disposed in (S560). Specifically, the control unit 55 controls the CR motor 65 to move the line sensor 40 disposed at the reading position corresponding to the first position 31 to the reading position corresponding to the second position 32. Then, the control unit 55 causes the line sensor 40 to perform an operation of reading one line of the document conveyed on the first glass 18 at the reading position corresponding to the second position 32. Thus, one line of the second area of the document is read with the focus of the line sensor 40 shifted from the reading surface 25 of the document on the first glass 18. That is, the second area of the document is read with blur.

  The controller 55 determines whether or not the second area of the conveyed document has passed through the reading surface 25 (see FIG. 5B) of the first glass 18 corresponding to the second position 32 (S562). The determination in step S562 is made based on the information on the first area and the second area set in the EEPROM 59, and the number of steps of the motor 72 after the ADF 28 starts conveying the document. When the control unit 55 determines that the second area of the document has not passed (S562: NO), the process of step S560 is continued. As a result, the process of step S560 is repeated and the image of the entire second area of the document is read. If the control unit 55 determines that the second region has passed (S562: YES), the process proceeds to step S561. When it is determined that the document has passed over the first glass 18 (S561: YES), the control unit 55 determines that the document has been read, and the process proceeds to step S563.

  In the present embodiment, several lines of the first area of the original are read by the process of step S558, and then the second area of the original is read by the process of step S560. However, the order of the read areas is not limited to this, and the reading may be started from the second area of the document. Further, it may be determined whether the reading start position in the document reading area is the first area or the second area, and the process may proceed to step S558 or step S560 based on the determination result.

  The original image (image signal) read by the processes in steps S558 and S560 is sequentially output to the AFE circuit 78 and serially processed. When the control unit 55 determines YES in the process of step S561, the image processing circuit 79 performs shading correction on the image of the first region based on the first white reference data 90 acquired by the process of step S554 (S563). . Further, the image processing circuit 79 corrects the shading of the image of the second area based on the second white reference data 91 obtained by the process of step S556 (S564). As described above, the control unit 55 changes the white reference data in accordance with the reading area of the image of the document that is subjected to the shading correction by the image processing circuit 79.

  The reading area of the line sensor 40 in the document is divided into a first area and a second area. In the main scan of the conveyed document, the first relative distance between the document reading surface 25 and the line sensor 40 on the first glass 18 is determined by driving the CR motor 65 that moves the line sensor 40. Be changed. For this reason, the second area of the document can be blurred and read without providing a drive source different from the CR motor 65. That is, it is possible to obtain an image of a document in which the first area is clear and the second area is blurred.

  The image of the original obtained by the main scan is subjected to shading correction for each reading area by the image processing circuit 79. Since the first relative distance is changed in the main scan of the conveyed document, the amount of reflected light from the document to the line sensor 40 changes during reading of the document. In the present embodiment, the first white reference data 90 is used for shading correction of the first area of the document, and the second white reference data 91 is used for shading correction of the second area of the document. As described above, by changing the white reference data according to the reading area of the document, it is possible to obtain a document image having a constant quality corresponding to the change in the relative distance.

  It should be noted that in the main scan of the conveyed document, two reading operations may be continuously executed, and the image of the document obtained by each reading operation may be combined. That is, in the main scan of the document conveyed by the ADF 28, the reading operation for reading the image of the entire conveyed document is executed in a state where the line sensor 40 is disposed at the reading position corresponding to the first position 31. After this reading operation is completed, the roller 73 is reversely rotated to return the conveyed document to the position before reading. Then, in a state where the line sensor 40 is disposed at the reading position corresponding to the second position 32, the image of the entire conveyed document is read. The controller 55 combines the image of the first area obtained by the first reading operation and the image of the second area obtained by the second reading operation to generate an image of the entire document.

  Further, here, a description has been given of a mode in which the first area of the document is read by the line sensor 40 arranged at the reading position corresponding to the first position 31, but the first area of the document suppresses the occurrence of moire. Alternatively, the reading may be performed in a state where the line sensor 40 is arranged at a position slightly shifted from the reading position corresponding to the first position 31.

  As shown in FIGS. 15 and 16, when it is determined that the first mode has been selected (S44: first mode), the control unit 55 receives the selection of the first mode and executes the second process (S58). ).

  FIG. 21 is a detailed flowchart of the second process.

  The control unit 55 determines whether or not a document is placed on the document tray 22 in the same manner as the process of step S551 (S581). When the control unit 55 determines that no document is placed on the document tray 22 (S581: NO), a standby state is entered. When it is determined that a document is placed on the document tray 22 (S581: YES), the control unit 55 determines whether or not a document reading start command has been issued (S582), as in the process of step S552. When the control unit 55 determines that there is no reading start command (S582: NO), a standby state is entered.

  When the control unit 55 determines that there is a document reading start command (S582: YES), the line sensor 40 is moved to the reading position corresponding to the first position 31 with respect to the reference member 37 in the same manner as the processing in step 34. Move (S583). And the control part 55 acquires the 1st light quantity adjustment value 101 and the 1st white reference data 90 similarly to the process of step S35 (S584). The acquired first light amount adjustment value 101 and the first white reference data 90 are stored in a predetermined area of the RAM 58.

  Following the process of step S584, the control unit 55 starts conveying the document in the same manner as the process of step S557 (S585). The control unit 55 pre-scans the document conveyed by the ADF 28 with the line sensor 40 disposed at the reading position (see FIG. 5A) corresponding to the first position 31 (S586). The control unit 55 determines whether or not the document conveyed by the ADF 28 has passed over the first glass 18 (S587). When the control unit 55 determines that the document does not pass through the first glass 18 (S587: NO), the process of step S586 is continued. When the control unit 55 determines that the document has passed over the first glass 18 (S587: YES), the image processing circuit 79 converts the document image obtained by the prescan in step S586 into the first white reference data 90. Based on this, shading correction is performed (S588). The control unit 55 reversely rotates the motor 72 to return the document conveyed by the ADF 28 to the position before the conveyance start in S585 (S589).

  As described above, by performing the second process, the image of the document conveyed by the ADF 28 is pre-scanned in a state where the line sensor 40 is disposed at the reading position corresponding to the first position 31. The document image obtained by the pre-scan is stored in a predetermined area of the RAM 58 and used as a section of the reading area.

  As shown in FIG. 16, after performing the second process, the control unit 55 notifies that selection of area setting, character setting, or figure setting is prompted (S60). For example, the control unit 55 causes the operation panel 13 to display a message such as “Please select area setting, character setting, or graphic setting”. The area setting is a setting in which a user inputs designation information for an image of a document obtained by pre-scanning, and the reading area is divided into a first area and a second area based on the inputted designation information. In the character setting, a character specified by the user is detected from an image of a document obtained by pre-scanning, and a second area including an area including the detected character is divided, and another area is divided into a first area. It is a setting. The graphic setting is a setting in which a graphic designated by the user is detected from an image of a document obtained by pre-scanning, and an area including the detected graphic is divided into second areas and other areas are divided into first areas. It is. The control unit 55 determines whether any of area setting, character setting, and figure setting has been selected based on the presence or absence of a predetermined operation on the operation panel 13 (S61). When the control unit 55 determines that no setting is selected (S61: NO), the process of step S60 is continued.

  When it is determined that any setting is selected (S61: YES), the control unit 55 determines whether the selection is an area setting (S62). When the control unit 55 determines that the selection is an area setting (S62: YES), the control unit 55 displays an image of the document obtained in the second process on the operation panel 13 and notifies that the input of the designation information is prompted. (S63). Specifically, the control unit 55 causes the operation panel 13 to display a document image obtained by prescanning and a display screen similar to the region setting screen 132. For example, the control unit 55 causes the operation panel 13 to display an area setting screen 132 on which an image obtained by pre-scanning is displayed in the reading area 141 (see FIG. 19A).

  Based on the presence / absence of a predetermined operation on the operation panel 13, the control unit 55 determines whether designation information has been input for the document image obtained by the pre-scan (S64). When the control unit 55 determines that the designation information has not been input (S64: NO), the process of step S63 is continued. When it is determined that the designation information has been input (S64: YES), the controller 55 receives the designation information and divides the reading area into the first area and the second area based on the designation information (S65). Information on the partitioned first area and second area is stored in a predetermined area of the EEPROM 59. After the process of step S65 is performed, the above-described first process, which is a main scan of the document, is performed based on the information of the first area and the second area set in this process.

  In the scanner 10, an image of the prescanned document is displayed on the operation panel 13. An input of designation information for designating an area for the displayed document image is received by the control unit 55 via the operation panel 13. The document reading area in the main scan is divided into a first area and a second area based on the designation information. For this reason, the user can easily specify a region to be blurred by looking at the pre-scan image displayed on the scanner 10.

  As shown in FIGS. 16 and 17, when the control unit 55 determines that the selection is not an area setting (S62: NO), the control unit 55 determines whether the selection is a character setting (S69). That is, the control unit 55 determines whether the selection is a character setting or a graphic setting. When the control unit 55 determines that the selection is character setting (S69: YES), the control unit 55 displays a character setting screen 134 (an example of a second setting screen in the present invention) illustrated in FIG. 19B (S70). ). The character setting screen 134 is a display screen for the user to input characters.

  On the character setting screen 134, a table 122, a reference button 137, an edit button 138, a save button 139, a check box 133, and the like are displayed. The table 122 displays settable characters. When the reference button 137 is pressed, characters stored in the EEPROM 59 are read and displayed on the table 122. When the edit button 138 is pressed, the user can input characters by operating the operation panel 13. When the save button 139 is pressed, the input characters are saved in the EEPROM 59. The user operates the reference button 137, the edit button 138, the save button 139, etc., and displays the characters to be blurred and read on the table 122. The setting of the characters displayed in the table 122 is accepted when the check box 133 is checked.

  The control unit 55 determines whether or not a character is input based on whether or not the save button 139 is operated (S71). When it is determined that a character has been input on the character setting screen 134 (S71: YES), the control unit 55 stores the input character in the EEPROM 59 (S72). When the process of step S72 is performed or when it is determined that no character is input (S71: NO), the control unit 55 determines whether a character is selected (S73). Specifically, it is determined whether or not the check box 133 is checked in a state where characters are displayed in the table 122. If the control unit 55 determines that no character is selected (S73: NO), the process returns to step S70.

  When it is determined that a character has been selected (S73: YES), the control unit 55 accepts the selection of the character and detects the character from the document image obtained in the second process (S74). Specifically, the control unit 55 performs an OCR (Optical Character Recognition) process on the image of the document obtained by the pre-scan of the second process. That is, the control unit 55 analyzes the document image obtained by the pre-scan and converts it into character data. And the control part 55 detects the character judged to have been selected by the process of step S73 from character data.

  The control unit 55 determines whether a character is detected (S75). When the control unit 55 determines that a character is detected (S75: YES), the control unit 55 divides an area including the detected character into a second area and divides the area into first areas of other areas (S76). For example, when a character “name” is detected from an image of a document obtained by pre-scanning, a line in the main scanning direction including the character “name” is partitioned into a second region 95 from the reading region 47 of the document ( (See FIG. 14). As a result, the personal information written next to the name is blurred and read. Information on the partitioned first area and second area is stored in the EEPROM 59.

  The control unit 55 executes the first process described above based on the information on the first area and the second area partitioned in the process of step S76 (S77). If the control unit 55 determines that the selected character is not detected from the document image obtained by the pre-scan of the second process (S75: NO), the selected character is not included in the document image. This is notified (S78). Specifically, the control unit 55 causes the operation panel 13 to display a message such as “The selected character was not detected”.

  In the second process (step S58), since the document is pre-scanned with the line sensor 40 in focus, a part of the series of processes described above may be changed as follows. The control unit 55 stores the image of the document obtained in the second process in the RAM 58. In the first process, the control unit 55 causes the line sensor 40 to read an image of the entire conveyed document in a state where the line sensor 40 is disposed at a reading position corresponding to the second position 32. Then, the control unit 55 combines the image of the second area obtained by the first process and the image of the first area obtained by the first process to generate an image of the entire document. As a result, it is not necessary to change the reading position of the line sensor 40 in the first process or to read the entire original twice. For this reason, the time required for the first process can be shortened, the load on the image reading unit 14 can be reduced, and the configuration of the scanner 10 can be simplified.

  As shown in FIGS. 17 and 18, when the control unit 55 determines that the selection is not a character setting (S69: NO), that is, when it is determined that the selection is a graphic setting, it is exemplified in FIG. 19C. The graphic setting screen 136 is displayed on the operation panel 13 (S81). The figure setting screen 136 is a display screen for the user to input a figure.

  On the figure setting screen 136, a figure 145, a pattern edit button 146, a list display button 147, a check box 143, and the like are displayed. The user can input a figure by pressing the pattern editing button 146 and performing a predetermined operation. The inputted figure and the figure saved in the EEPROM 59 are displayed on the figure setting screen 136 as the figure 145. The list display button 147 is a key for reading out a saved graphic and displaying it as a graphic 145. The setting of the graphic 145 displayed on the graphic setting screen 136 is accepted when the check box 143 is checked.

  The control unit 55 determines whether or not a figure is input based on the presence / absence of a predetermined operation from the operation panel 13 (S82). When it is determined that a figure has been input (S82: YES), the control unit 55 stores the input figure in the EEPROM 59 (S83). The controller 55 determines whether or not a graphic has been selected after performing the process of step S83 or when it is determined that a graphic has not been input (S82: NO) (S84). Specifically, the control unit 55 determines whether or not the check box 143 is checked while the graphic 145 is displayed on the graphic setting screen 136. If the control unit 55 determines that no graphic is selected (S84: NO), the process returns to step S81. When determining that the figure has been selected (S84: YES), the control unit 55 detects the selected figure from the image of the document obtained by the second process (S85). The control unit 55 determines whether or not a figure is detected from the document image obtained in the second process (S86).

  If the control unit 55 determines that a figure has been detected from the document image obtained in the second process (S86: YES), the control unit 55 divides the area including the detected figure into the second area, and sets other areas as the other areas. The first area is partitioned (S87). The process of step S87 is performed in the same manner as the process of step S76. The control unit 55 executes the first process based on the information on the first area and the second area partitioned in the process of step S87 (S88).

  In the second process (step S58), since the document is pre-scanned with the line sensor 40 in focus, a part of the series of processes described above may be changed as follows. The control unit 55 stores the image of the document obtained in the second process in the RAM 58. In the first process, the control unit 55 causes the line sensor 40 to read an image of the entire conveyed document in a state where the line sensor 40 is disposed at a reading position corresponding to the second position 32. Then, the control unit 55 combines the image of the second area obtained by the first process and the image of the first area obtained by the first process to generate an image of the entire document. As a result, it is not necessary to change the reading position of the line sensor 40 in the first process or to read the entire original twice. For this reason, the time required for the first process can be shortened, the load on the image reading unit 14 can be reduced, and the configuration of the scanner 10 can be simplified.

  When it is determined that no graphic is detected from the original image obtained in the second process (S86: NO), the control unit 55 notifies that the selected graphic is not included in the original image (S89). ). Specifically, the control unit 55 causes the operation panel 13 to display a message such as “The selected figure was not detected”.

  22 to 24 are flowcharts illustrating a procedure of processes performed in the scanner 10 when information for selecting the blur mode is received from the terminal device 140.

  The control unit 55 determines whether information for selecting the blur mode is received from the terminal device 140 (S91). When the control unit 55 determines that information for selecting the blur mode has not been received (S91: NO), a standby state is entered. When it is determined that the information for selecting the blur mode has been received (S91: YES), the control unit 55 transfers the designation information, characters, and figures stored in the EEPROM 59 to the terminal device 140 (S92).

  The terminal device 140 receives the designation information, characters, and graphics transferred from the scanner 10. The terminal device 140 displays the received information on the monitor and accepts the selection of the first mode or the second mode. When the second mode is designated by a keyboard or mouse operation, the terminal device 140 generates designation information based on a user operation input and transmits the designation information to the scanner 10. When the first mode is designated by the operation of the keyboard or mouse, the terminal device 140 transmits a prescan command to the scanner 10.

  The control unit 55 of the scanner 10 determines whether designation information is received from the terminal device 140 (S93). When it is determined that the designation information has been received (S93: YES), the control unit 55 divides the document reading area into a first area and a second area based on the received designation information (S94). The process of step S94 is performed in the same manner as the process of step S51. The control unit 55 executes the first process based on the information on the first area and the second area partitioned in the process of step S94 (S95).

  The designation information transmitted from the terminal device 140 is received by the scanner 10. The document reading area in the main scan is divided into a first area and a second area based on the designation information. For this reason, the user can arbitrarily specify the first area and the second area on the terminal device 140 to blur and read a partial area of the document.

  When determining that the designation information has not been received (S93: NO), the control unit 55 determines whether or not a pre-scan command has been received from the terminal device 140 (S96). If the control unit 55 determines that a pre-scan command has not been received (S96: NO), the process returns to step S93. When it is determined that the pre-scan command has been received (S96: YES), the control unit 55 executes the second process (S100). The control unit 55 transfers the document image obtained by the second process to the terminal device 140 (S101).

  For example, in the terminal device 140, an image of a document is displayed on a monitor. Based on the operation input of the user who viewed the image of the document displayed on the monitor, the designation information, characters, or figures are generated by the terminal device 140. The designation information, characters, or figures are transmitted to the scanner 10.

  The control unit 55 of the scanner 10 determines whether or not the designation information transmitted from the terminal device 140 has been received (S102). When the control unit 55 determines that the designation information has been received (S102: YES), the process proceeds to step S94. When determining that the designation information has not been received (S102: NO), the control unit 55 determines whether a character or a graphic has been received from the terminal device 140 (S103). If the control unit 55 determines that no character or graphic has been received (S103: NO), the process returns to step S102.

  When it is determined that the character or graphic is received (S103: YES), the control unit 55 determines whether the received information is a character or a graphic (S104). When the control unit 55 determines that the received information is a character (S104: character), the control unit 55 detects the received character from the document image obtained by the second process (S105). The process of step S105 is performed in the same manner as the process of step S74. As a result of performing the process of step S105, the control unit 55 determines whether or not the received character is detected from the document image obtained by the pre-scan (S106). When the control unit 55 determines that a character is detected (S106: YES), the control unit 55 partitions the area including the detected character into the second area, and partitions the other areas into the first area (S107). The process in step 107 is performed in the same manner as the process in step 76. The control unit 55 executes the first process based on the information of the first area and the second area divided in the process of step S107 (S108).

  When determining that no character is detected (S106: NO), the control unit 55 transmits information for notifying that the received character is not included in the image of the document to the terminal device 140 (S109). As a result, for example, a message such as “The specified character is not included in the document” is displayed on the monitor of the terminal device 140.

  When the control unit 55 determines that the received information is a graphic (S104: graphic), the control unit 55 detects the received graphic from the document image obtained by the second process (S111). The process of step S111 is performed in the same manner as the process of step S85. As a result of performing the process of step S111, the control unit 55 determines whether or not the received graphic is detected from the image of the document obtained by the second process (S112). When it is determined that a graphic is detected (S112: YES), the controller 55 partitions the area including the detected graphic into the second area, and partitions the other areas into the first area (S113). The process of step S113 is performed in the same manner as the process of step S87. The control unit 55 executes the first process based on the information of the first area and the second area partitioned in the process of step S113 (S114).

  When it is determined that no graphic is detected (S112: NO), the control unit 55 transmits information for notifying that the received graphic is not included in the image of the document to the terminal device 140 (S115). As a result, for example, a message such as “The specified graphic is not included in the document” is displayed on the monitor of the terminal device 140.

  The reading area of the line sensor 40 on the document conveyed by the ADF 28 is divided into a first area and a second area. The reading area is divided based on the image of the original obtained by prescanning (second processing) of the original or user settings. In the main scan of the conveyed document, the first relative distance between the reading surface 25 of the document on the first glass 18 and the line sensor 40 depends on the partitioned area by driving the CR motor 65 that moves the line sensor 40. Changed. That is, when reading the first area of the document, the line sensor 40 is disposed at a reading position corresponding to the first position 31. When reading the second area of the document, the line sensor 40 is disposed at a reading position corresponding to the second position 32. Therefore, it is possible to blur and read a partial area of the conveyed document without providing a drive source different from the CR motor 65.

  In the blur mode, the scanner 10 is set to the first mode or the second mode. In the first mode, the reading area is divided based on the result of the pre-scan. In the second mode, the reading area is partitioned based on user settings. When the selection of the first mode is accepted, the line sensor 40 executes a prescan of the conveyed document. Then, based on the image of the original obtained by the pre-scan, a reading area of the original read by the main scan is partitioned. As a result, for example, an image of a document obtained by pre-scanning is analyzed to partition a reading area, or a document image obtained by pre-scanning is displayed and the reading area is partitioned based on a user operation. be able to. When the selection of the second mode is accepted, the reading area of the document read in the main scan is partitioned based on the user setting. For example, by setting the same reading area for a plurality of documents, the plurality of documents are read under the same conditions. In the second mode, the document is not pre-scanned.

  In the scanner 10 according to the present embodiment, designation information, characters, or figures input from the operation panel 13 or received from the terminal device 140 are stored in the EEPROM 59. For this reason, the user can designate the second region without inputting such information by registering designation information, characters, or graphics. That is, when a document is read by designating the same first area and second area for a plurality of documents, it is not necessary to input characters or figures for each document. Note that the designation information, characters, and figures stored in the EEPROM 59 are not limited to these pieces of information. The designation information, characters, or graphics stored in the scanner 10 may be written in the ROM 57 in advance before shipping the scanner 10, for example.

  The second glass 20 according to the present embodiment may be configured to be movable up and down in the height direction of the scanner 10.

  FIG. 25 is a schematic diagram showing the lifting mechanism 110 for the second glass 20.

  As shown in FIG. 25, the elevating mechanism 110 includes a fixing member 111, a slide member 112, support members 113 and 114, and coil springs 115, 116, 117, and 118. Support members 113 and 114 are fixed to both ends of the second glass 20 in the depth direction of the scanner 10 (the direction indicated by the arrow 39). The fixing member 111 supports the support member 113 via the coil springs 115 and 116. The fixing member 111 is fixed to the housing 15. The slide member 112 supports the support member 114 via the coil springs 117 and 118. The slide member 112 is provided to be slidable in the depth direction of the scanner 10 with respect to the housing 15. A driving force from a motor (not shown) is transmitted to the slide member 112. The slide member 112 slides by receiving this driving force. The fixed member 111 and the slide member 112 are provided with inclined surfaces 118 and 119 that descend toward the second glass 20. A contact surface 120 parallel to the inclined surface 118 is formed on the support member 113. A contact surface 121 parallel to the inclined surface 119 is formed on the support member 114.

  The slide member 112 receives the driving force from the motor and slides in a direction close to the fixed member 111 (left direction in FIG. 25). The support member 113 is pushed up by the inclined surface 118 and the support member 114 is pushed up by the inclined surface 119, and the second glass 20 is raised. The coil springs 115 and 117 are contracted as the second glass 20 rises, and accumulate a spring force that pushes the second glass 20 downward. The coil springs 116 and 118 are stretched as the second glass 20 is raised, and store a spring force that pulls the second glass 20 downward. The slide member 112 slides in a direction away from the fixed member 111 (right direction in FIG. 25) when the motor is rotated in the reverse direction. The support members 113 and 114 are moved downward along the inclined surfaces 118 and 119 by the spring force accumulated by the coil springs 115 to 118, and the second glass 20 is lowered.

  As described above, the document reading surface 25 of the first glass 18 is inclined with respect to the moving surface of the line sensor 40. For this reason, as the line sensor 40 moves, the height of the reading surface 25 corresponding to the line sensor 40 changes. By moving the second glass 20 up and down so that the upper surface of the second glass 20 and the height of the reading surface 25 coincide with each other, the reading mode is changed even in the FBS and the original placed on the second glass 20 is read. Is possible. That is, even in the FBS, the original can be read in the normal mode and the blur mode.

[Second Embodiment]
The second embodiment of the present invention will be described below. The second embodiment is the same as the first embodiment except that the first glass 18 and its peripheral configuration, and the reference member 37 and its peripheral configuration are different. Therefore, the description of the other configurations is omitted. The

  26 and 27 are schematic cross-sectional views showing a part of the conveyance path 12 in the scanner 10 according to the second embodiment of the present invention.

  In the scanner 10 according to the second embodiment of the present invention, the first glass 18 and the reference member 37 are provided in parallel with the moving surface of the line sensor 40. Further, on the back surface of the guide member 34, first spacers 94 are provided on the upstream side and the downstream side in the document transport direction with respect to the first glass 18. The first spacer 94 is interposed between the line sensor 40 and the first glass 18 with the line sensor 40 facing the first glass 18. The first spacer 94 has a thickness that changes stepwise in the direction in which the line sensor 40 moves (the direction indicated by the arrow 38 in FIG. 26). The first spacer 94 is formed with a stepped portion 26 whose thickness increases stepwise from the upstream side to the downstream side in the conveyance direction of the document conveyed by the ADF 28. On the other hand, the carriage 41 has step portions 50 at both ends in the longitudinal direction where the rollers 30 are provided. The step portion 50 is formed so as to increase stepwise from the downstream side to the upstream side in the transport direction of the document transported by the ADF 28 corresponding to the step portion 26.

  The guide shaft 42 is supported by the housing 15 so as to be movable up and down while being biased upward. The carriage 41 moves in the direction indicated by the arrow 38 so that the stepped portion 50 of the carriage 41 moves up and down the stepped portion 26. For example, the carriage 41 moves from the downstream side in the document transport direction toward the upstream side (see FIGS. 26 and 27). As a result, the height of the line sensor 40 mounted on the carriage 41 changes. As a result, the first relative distance, which is the relative distance between the line sensor 40 and the original reading surface 25 of the first glass 18, is changed from D5 to D6. Thus, the line sensor 40 is moved toward or away from the first glass 18 by being moved by the CR motor 65. In FIGS. 26 and 27, the first spacer 94 is provided with two step portions 26 so that the first relative distance is changed to two steps. One relative distance may be changed in three steps or more.

  The second spacers 96 are provided on both sides of the reference member 37 in the width direction of the scanner 10 (the direction indicated by the arrow 38). The second spacer 96 is interposed between the line sensor 40 and the reference member 37 with the line sensor 40 facing the reference member 37. The second spacer 96 has the same shape as the first spacer 94. That is, the thickness of the second spacer 96 changes stepwise in the direction in which the line sensor 40 moves (the direction indicated by the arrow 38). When the line sensor 40 is moved to face the reference member 37, the second relative distance between the line sensor 40 and the reading surface of the reference member 37 is changed stepwise.

  FIG. 28 is a schematic cross-sectional view showing the first spacer 104 and the second spacer 106.

  The first spacer and the second spacer in the present invention are not limited to the first spacer 94 and the second spacer 96. That is, as shown in FIG. 28, the first spacer and the second spacer in the present invention are the first spacer 104 and the second spacer 106 whose thickness changes in a wedge shape in the direction in which the line sensor 40 moves. Also good.

FIG. 1 is a perspective view showing an external configuration of the scanner 10 according to the first embodiment of the present invention, and shows a state in which a document cover 17 is opened. FIG. 2 is a schematic cross-sectional view showing a part of the conveyance path 12 in the scanner 10 according to the first embodiment of the present invention. FIG. 3 is a plan view showing the internal configuration of the document table 11. FIG. 4 is a block diagram illustrating a configuration example of the control unit 55 of the scanner 10. FIG. 5 is a schematic cross-sectional view illustrating the reading position of the line sensor 40, where (A) shows a reading position corresponding to the first position 31, and (B) shows a reading position corresponding to the second position 32. FIG. 6 is a flowchart illustrating a procedure of reading position setting processing performed when the scanner 10 is powered on. FIG. 7 is a flowchart illustrating a procedure of reading position setting processing performed when the scanner 10 is powered on. FIG. 8 is a schematic diagram showing an example of the first test document 98. FIG. 9 is a schematic cross-sectional view showing how the reading position of the line sensor 40 is changed. FIG. 10 is a diagram showing the MTF characteristics obtained by reading the first test document 98. FIG. 11 is a schematic diagram showing an example of the second test document 99. FIG. 12 is a diagram showing the MTF characteristics obtained by reading the second test document 99. FIG. 13 is a flowchart showing a procedure of processing performed in the scanner 10 when an instruction to start reading a document is issued in the state where the normal mode is set. FIG. 14 is a schematic view illustrating the document reading area 47. FIG. 15 is a flowchart showing a procedure of processing performed in the scanner 10 when an instruction to start reading a document is given from the operation panel 13 in a state where the blur mode is set. FIG. 16 is a flowchart showing a procedure of processing performed in the scanner 10 when an instruction to start reading a document is given from the operation panel 13 in the state in which the blur mode is set. FIG. 17 is a flowchart illustrating a procedure of processes performed in the scanner 10 when an instruction to start reading a document is issued from the operation panel 13 in the state in which the blur mode is set. FIG. 18 is a flowchart illustrating a procedure of processes performed in the scanner 10 when an instruction to start reading a document is issued from the operation panel 13 in the state in which the blur mode is set. FIG. 19 is a schematic diagram illustrating an example of a setting screen displayed on the operation panel 13. FIG. 20 is a detailed flowchart of the first process. FIG. 21 is a detailed flowchart of the second process. FIG. 22 is a flowchart illustrating a procedure of processing performed in the scanner 10 when information for selecting the blur mode is received from the terminal device 140. FIG. 23 is a flowchart illustrating a procedure of processing performed in the scanner 10 when information for selecting the blur mode is received from the terminal device 140. FIG. 24 is a flowchart illustrating a procedure of processing performed in the scanner 10 when information for selecting the blur mode is received from the terminal device 140. FIG. 25 is a schematic diagram showing the lifting mechanism 110 for the second glass 20. FIG. 26 is a schematic cross-sectional view showing a part of the conveyance path 12 in the scanner 10 according to the second embodiment of the present invention. FIG. 27 is a schematic cross-sectional view showing a part of the conveyance path 12 in the scanner 10 according to the second embodiment of the present invention. FIG. 28 is a schematic cross-sectional view showing the first spacer 104 and the second spacer 106.

10... Scanner (an example of an image reading apparatus according to the present invention)
12 ... Conveying path (corresponding to the path of the present invention)
13 ... operation panel (equivalent to the first display unit, the second display unit, and the third display unit of the present invention)
18 ... 1st glass (an example of the 1st penetration member of the present invention)
20 ... 2nd glass (an example of the 2nd transmission member of the present invention)
25, 27 ... reading surface 37, 53 ... reference member 40 ... line sensor 55 ... control unit (partitioning unit, first control unit, first receiving unit, changing unit, second of the present invention) Reception unit, first reception unit, third reception unit, first transfer unit, second reception unit, fourth reception unit, fifth reception unit, detection unit, second transfer unit, third reception unit, sixth reception unit , Equivalent to second control unit, calculation unit, determination unit)
59... EEPROM (corresponding to the first storage unit and the second storage unit of the present invention)
65... CR motor (corresponding to the drive unit of the present invention)
79... Image processing circuit (corresponding to the correction unit of the present invention)
90... First white reference data (an example of white reference data of the present invention)
91: Second white reference data (an example of white reference data of the present invention)
94, 104 ... first spacer 96, 106 ... second spacer 98 ... first test document (an example of a test document of the present invention)
99: Second test document (an example of a test document of the present invention)

Claims (19)

A first transmission member provided in a path along which the document is conveyed;
A second transmission member on which a document is placed;
A contact-type line sensor that irradiates a document with light from a light source through the first transmission member or the second transmission member and reads reflected light from the document for each main scanning line;
A drive unit that moves the line sensor to face the first transmission member or the second transmission member;
The line in the document to be transported based on the image of the document obtained by pre-scanning the document to be transported by the line sensor disposed opposite to the first transmission member by the driving unit, or based on user settings. A partition section that divides the reading area of the sensor into a plurality of areas;
A first control unit that controls the driving of the driving unit to move the line sensor and changes a relative distance between the reading surface of the first transmitting member and the line sensor inclined with respect to a plane on which the line sensor moves. A control unit,
It said first control unit, in the main scan by the line sensor of the document to be the conveying, the image reading apparatus is to change the relative distance to each is the partitioned region. 2. The image reading apparatus according to claim 1 , wherein the reading surface of the first transmission member is separated from the plane on which the line sensor moves on the downstream side of the path along the document transport direction on the path. A first transmission member provided in a path along which the document is conveyed;
A second transmission member on which a document is placed;
A contact-type line sensor that irradiates a document with light from a light source through the first transmission member or the second transmission member and reads reflected light from the document for each main scanning line;
A drive unit that moves the line sensor to face the first transmission member or the second transmission member;
The line in the document to be transported based on the image of the document obtained by pre-scanning the document to be transported by the line sensor disposed opposite to the first transmission member by the driving unit, or based on user settings. A partition section that divides the reading area of the sensor into a plurality of areas;
A first control unit for controlling the driving of the driving unit to move the line sensor ;
The thickness of the line sensor changes in a stepped shape or a wedge shape in the moving direction, and the line sensor is interposed between the line sensor and the first transmission member in a state of facing the first transmission member, and moves. A first spacer that contacts the line sensor and changes a relative distance between the first transmission member and the line sensor;
The first control unit, in the main scan by the line sensor of the document to be the conveying, the image reading apparatus is to change the relative distance to each is the partitioned region. A first receiving unit that receives a selection of a first mode that divides the reading area based on the result of the pre-scan or a second mode that divides the reading area based on a user setting;
The partitioning unit is configured to cause the line sensor to execute the prescan on the condition that the first mode selection is received by the first reception unit and to perform the reading based on an original image obtained by the prescan. An area is partitioned, and the reading area is partitioned based on the user setting without causing the line sensor to execute the pre-scan on the condition that the selection of the second mode is received by the first receiving unit. The image reading apparatus according to any one of 1 to 3 . A correction unit that corrects shading of the image of the document obtained by the main scan based on white reference data;
The image reading apparatus according to any one of claims 1 to 4; and a changing unit for changing the white reference data in accordance with the reading region of the image of the document to be the shading correction. The partition section partitions the reading area into a first area and a second area,
The first control unit causes the line sensor to read the first region in a state where the relative distance is substantially coincident with the focal length of the line sensor, and the relative distance is different from the focal length. the image reading apparatus according to claim 1 of a line sensor in which to read the second region 5. A first display for displaying a first setting screen for inputting designation information for designating the first area or the second area;
A second accepting unit for accepting input of the designation information on the first setting screen,
The image reading apparatus according to claim 6 , wherein the partition unit partitions the reading region based on designation information received by the second receiving unit. A first receiving unit for receiving designation information for designating the first area or the second area from a terminal device connected to be communicable with the own apparatus;
The image reading apparatus according to claim 6 , wherein the partition unit partitions the reading region based on the designation information received by the first receiving unit. A second display unit for displaying an image of the document obtained by the prescan;
A third accepting unit for accepting an input of designation information for designating the first area or the second area with respect to the displayed document image;
The image reading apparatus according to claim 6 , wherein the partition unit partitions the reading region based on designation information received by the third receiving unit. A first transfer unit that transfers an image of a document obtained by the pre-scan to a terminal device connected to be communicable with the own device;
A second receiving unit for receiving designation information for designating the first area or the second area for the transferred document image from the terminal device;
The image reading apparatus according to claim 6 , wherein the partition unit partitions the reading region based on the designation information received by the second receiving unit. A first storage unit for storing designation information for designating the first area or the second area;
A fourth reception unit that receives selection of the designation information stored in the first storage unit,
The partition unit, on condition that the selection of the specified information is accepted by the fourth receiving unit, an image reading apparatus according to any one of 10 claims 6 to partition the reading area on the basis of the designation information . A third display for displaying a second setting screen for inputting characters or figures;
A fifth accepting unit for accepting input of characters or figures to the second setting screen;
A detection unit that detects a character or a figure whose input is received by the fifth reception unit from the image of the document obtained by the pre-scan,
The image reading apparatus according to claim 6 , wherein the partition unit partitions a region including characters or figures detected by the detection unit into the second region. A second transfer unit for transferring an image of the document obtained by the pre-scan to a terminal device connected to be communicable with the own device;
A third receiving unit for receiving characters or graphics transmitted from the terminal device in response to transfer of the image of the document;
A detection unit that detects a character or a figure received by the third reception unit from an image of the document obtained by the prescan,
The image reading apparatus according to claim 6 , wherein the partition unit partitions a region including characters or figures detected by the detection unit into the second region. A second storage unit for storing the character or figure;
A sixth accepting unit for accepting selection of characters or figures stored in the second storing unit,
The detection unit, on condition that the selection of the characters or graphics is accepted by the sixth receiving unit, wherein the character or graphics in claim 12 or 13 for detecting the image of the document obtained in the prescan Image reading apparatus. A second control unit that causes the line sensor to perform an operation of reading a test document in which a predetermined pattern is recorded at a plurality of positions having different relative distances through the first transmission member;
An arithmetic unit for obtaining an MTF (Modulation Transfer Function) value for each of the plurality of positions based on the image signal of the test document obtained by the operation;
A reading position where the line sensor is arranged by the driving unit when reading the first area of the conveyed document in the main scan, and the line sensor is read by the driving unit when reading the second area of the document. the image reading apparatus according to any one of the deployed are reading position from claim 6 and a determination unit that determines based on the respective MTF values 14. The image reading apparatus according to claim 15 , wherein the determining unit determines a position where the MTF value is maximum as a reading position of the line sensor that reads the first region. The determination unit includes an image reading apparatus according to a position where MTF value is equal to or less than a predetermined percent of the maximum value to claim 15 or 16 to determine the reading position of the line sensor for reading the second region. The line sensor has a reading surface read by the line sensor as a lightness reference of the line sensor, and the reading surface includes a reference member inclined with respect to the moving surface of the line sensor ,
The first control unit controls driving of the driving unit, and the relative distance between the reading surface of the reference member and the line sensor is such that the reading surface of the first transmitting member and the line sensor at the time of reading by the line sensor and moving the line sensor to the same in a position with the relative distance, the image reading apparatus according to any one of claims 1 to 17 in the line sensor in which to read the reading surface of the reference member. A reference member read by the line sensor as a lightness reference of the line sensor ;
The line that is moved in the direction in which the line sensor moves changes in a stepped shape or a wedge shape, and is interposed between the line sensor and the reference member in a state where the line sensor faces the reference member. A second spacer that contacts the sensor and changes a relative distance between the reference member and the line sensor ;
The first control unit controls driving of the driving unit, and the relative distance between the reading surface of the reference member and the line sensor is such that the reading surface of the first transmitting member and the line sensor at the time of reading by the line sensor and moving the line sensor to the same in a position with the relative distance, the image reading apparatus according to any one of claims 1 to 17 in the line sensor in which to read the reading surface of the reference member.

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