JP2012090085A - Image reading apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the size of an original document without using a dedicated sensor.SOLUTION: An image reading apparatus includes: a movable guide 29b that is slidable on an ADF insertion tray 26 of an ADF unit; an interlocking mechanism 82 that is fixed to a lower surface of the movable guide 29b and interlocks with sliding of the movable guide 29b; and a displacement member 84 that is fixed to a lower surface of the interlocking mechanism 82 and has three marks 84a formed on a surface opposite to a detecting region 38 formed in a housing 21. The apparatus controls a CIS 74 as a sensor for reading an original document so as to read the detecting region 38, and determines the size of a set original document S on the basis of an output pattern of a plurality of light receiving elements 75a obtained by reading and a correspondence relationship previously stored in a ROM. According to the present invention, the apparatus can determine the size of the original document by using the sensor for reading the original document, without using a dedicated sensor.

Description

  The present invention relates to a document reading apparatus.

  2. Description of the Related Art Conventionally, as this type of document reading apparatus, a device that reads an image of a document by an image reading sensor while sequentially conveying a plurality of documents set on a tray by an automatic document conveyance mechanism (ADF) has been proposed. (For example, refer to Patent Document 1). This apparatus includes a document guide that can slide along the width direction of a document set on an ADF tray, and a size determination sensor for detecting the slide position of the document guide. A controller that controls the entire apparatus detects the width of the document based on the output of the size determination sensor, and determines the document size based on the detected width.

  In addition, as a document reading apparatus including such an ADF, a casing on which a document table on which a document is placed is formed, and a casing cover that is attached to the top of the casing through a hinge mechanism so as to be opened and closed. Among devices provided, an apparatus in which an ADF is incorporated in a housing cover has been proposed (see, for example, Patent Document 2).

JP 2007-217160 A JP 2010-161756 A

  In the above-described apparatus, since the image reading sensor and the size determination sensor are provided, the number of components increases, for example, the number of necessary sensors increases. Along with this, it is necessary to increase the input ports of the controller. Furthermore, in the case where the ADF is incorporated in the housing cover, the wiring connecting the size determination sensor and the controller must be arranged in a small space in the hinge mechanism that connects the housing and the housing cover. The length of the wiring becomes longer than necessary. As described above, if the size determination sensors are individually provided, not only the number of parts increases, but also in terms of cost.

  The document reading apparatus of the present invention is mainly intended to determine the size of a document without using a dedicated sensor.

  The document reading apparatus of the present invention employs the following means in order to achieve the main object described above.

The document reading apparatus of the present invention is
An insertion section into which a document is inserted;
An automatic transport mechanism for automatically transporting a document set in the insertion portion;
A first unit for reading a document automatically conveyed by using the reading unit having a reading unit in which a plurality of photoelectric conversion elements are arranged in the main scanning direction is different from the first region. Reading means capable of reading the two areas;
An edge guide that guides an edge perpendicular to the conveyance direction of the document that is provided in the insertion portion so as to be slidable and automatically conveyed;
An interlocking mechanism that mechanically interlocks with the slide of the edge guide;
A displacement member that is attached to the interlocking mechanism and moves along with the interlocking of the interlocking mechanism and changes its position on the second region;
Storage means for storing correspondence information between size information for each size of the plurality of types of documents and output patterns of the plurality of elements;
A document size determining unit that controls the reading unit to read the second region and determines the size of the set document based on output patterns of the plurality of elements obtained by the reading and the correspondence relationship; The gist is to provide.

  In the document reading apparatus according to the present invention, an edge guide that guides an edge perpendicular to the transport direction of a document that is provided so as to be slidable in an insertion portion into which a document is inserted and is automatically transported, and mechanically slides the edge guide And a displacement member that changes its position on a second area that is different from the first area for reading a document that is attached to the interlocking mechanism and moves and moves automatically in conjunction with the interlocking mechanism. With. Then, the storage unit stores the correspondence between the size information for each type of the plurality of types of documents and the output patterns of the plurality of elements of the reading unit, controls the reading unit to read the second area, The size of the set document is determined based on the obtained output patterns of the plurality of elements and the stored correspondences. Thus, the size of the document can be determined using the reading unit that reads the automatically conveyed document without using a dedicated sensor. Here, examples of such a document reading device include a device that reads a document that is automatically conveyed by setting a reading range in accordance with the size of the set document.

  In addition to reading an automatically conveyed document, an area formed in the upper part of the housing where a document can be placed and aligned in the sub-scanning direction with the first area is defined as a third area. The document reading apparatus according to the present invention capable of reading, wherein the automatic transport mechanism is incorporated in a casing cover that is attached to an upper portion of the casing so as to be openable and closable, and the insertion portion is provided on an upper surface side of the casing cover. The displacement member is a member that is disposed on the lower surface side of the housing cover and moves along the lower surface of the housing cover in conjunction with the interlocking mechanism. You can also. If an automatic transport mechanism is built in the housing cover and a dedicated sensor is provided for size determination, the wiring must be routed in the hinge mechanism that connects the housing cover and the housing. Therefore, the significance of applying the present invention is high. In this aspect of the document reading apparatus of the present invention, the second area is formed between the first area and the third area in the sub-scanning direction, and the displacement member is formed by the housing cover. It may be a member that moves in the main scanning direction on the second region when it is in the closed state. In this way, when the size of the document is determined, the amount of movement of the reading unit to the second area can be relatively reduced.

  In the document reading apparatus of the present invention, the reading unit includes the plurality of elements arranged in the reading unit so as to be able to read an area having a margin in the main scanning direction with respect to the first area. The plurality of elements are means divided into an effective element for reading a document and a non-effective element different from the effective element, and the first region is formed as a region facing the effective element. The second region is formed as a region facing the ineffective element, and the displacement member moves in the main scanning direction over the second region when the housing cover is closed. The interlocking mechanism has a speed reduction mechanism that transmits the slide of the edge guide to the displacement member with a speed reduction ratio such that a change in the position of the displacement member is within the range of the second region. so It can also be a shall. Here, since ineffective elements are often arranged in the reading unit in addition to the effective elements, the size of the document can be efficiently determined using the ineffective elements.

  Further, in the document reading apparatus of the present invention, the displacement member is a member formed with a plurality of marks on a surface facing the reading means, and the interlocking mechanism includes a plurality of marks on the displacement member. The mechanism interlocks so that a different number of marks are positioned on the second region according to the slide of the edge guide, and the storage means has size information for each size of the plurality of types of documents as the correspondence relationship. And the number of marks positioned on the second area in association with each other, and the document size determination means includes the number of marks on the displacement member obtained by reading the second area It may be a means for determining the size of the document based on the correspondence relationship. In this way, the size of the document can be easily determined from the number of marks obtained by reading. Alternatively, in the document reading apparatus according to the present invention, the storage unit includes, as the correspondence relationship, size information for each size of the plurality of types of documents and an edge position of the tip of the displacement member on the second region. The document size determining means is a means for determining the size of the document based on the edge position of the tip of the displacement member obtained by reading the second area and the correspondence relationship. It can also be. In this way, the size of the document can be easily determined from the edge position of the tip of the displacement member obtained by reading.

FIG. 2 is a configuration diagram illustrating an outline of a configuration of a multifunction printer 20. FIG. 3 is an external view of the printer 20 in a state where a housing cover 22 is opened. FIG. 2 is a configuration diagram showing an outline of the configuration of a scanner unit 50. The block diagram which shows the outline of a structure of the interlocking mechanism 82 and the displacement member 84. FIG. The block diagram which shows the outline of a structure of the interlocking mechanism 82 and the displacement member 84. FIG. Explanatory drawing which shows the displacement of the displacement member 84 accompanying the slide of the movable guide 29b. Explanatory drawing which shows an example of the correspondence table 94a. 6 is a flowchart illustrating an example of a document size determination processing routine. The block diagram which shows the outline of a structure of the interlocking | linkage mechanism 182 and the displacement member 184 of a modification.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of the configuration of a multi-function printer 20 according to an embodiment of the present invention. FIG. 2 is an external view of the multi-function printer 20 with a housing cover 22 opened. FIG. 3 is a configuration diagram showing an outline of the configuration of the scanner unit 50.

  As shown in FIG. 1, the multi-function printer 20 of the present embodiment includes a housing 21 and a housing cover 22 that can open and close the upper surface of the housing 21. The multi-function printer 20 includes a printer unit 40 that feeds, prints, and discharges paper set in a cassette 23 to a paper discharge tray 24, and a scanner unit that optically reads a document and generates image data. 50 and a memory card controller 44 that controls input / output of data between the memory card MC inserted in the memory card slot 44a, an operation panel 45 that allows various operations by the user, and a main controller that controls the entire apparatus. 90. As shown in FIG. 2, a flat bed-like FB reading area 32 on which a glass plate on which an original can be placed is disposed is provided on the upper surface of the housing 21. The FB reading area 32 is placed on the FB reading area 32. The read document is fixed by the document presser 22a provided on the housing cover 22, and can be optically read by the scanner unit 50 (hereinafter, this reading mode is referred to as an FB reading mode). ). In addition, an auto document feeder unit 61 (hereinafter referred to as an ADF unit 61) that automatically and continuously feeds documents one by one is built in the upper portion of the housing cover 22 (see FIG. 3). The ADF reading area 34 in which a glass plate is disposed for reading a document automatically conveyed by the ADF unit 61 is formed. When the document automatically conveyed by the ADF unit 61 passes through the opening 22 c formed on the lower surface of the housing cover 22 with the housing cover 21 closed, the document passes over the ADF reading area 34. Thus, the scanner unit 50 can optically read (hereinafter, a mode for performing this reading is referred to as an ADF reading mode). A white reference plate 36 for so-called shading correction is provided at the end of the FB reading area 32 in the sub-scanning direction.

  As shown in FIG. 1, the printer unit 40 includes a printer ASIC 41 and a printer mechanism 42. The printer ASIC 41 is an integrated circuit that controls the printer mechanism 42. When receiving a print command from the main controller 90, the printer ASIC 41 controls the printer mechanism 42 to print an image on a sheet based on an image file that is a target of the print command. The printer mechanism 42 is configured as a well-known inkjet color printer mechanism that performs printing by ejecting ink from a print head onto paper. Since the printer unit 40 does not form the gist of the present invention, further explanation is omitted.

  The scanner unit 50 includes a scanner ASIC 51 and a scanner mechanism 60. The scanner ASIC 51 is an integrated circuit that controls the scanner mechanism 60. Upon receiving a scan command from the main controller 90, the scanner ASIC 51 reads the document as image data in either the FB reading mode or the ADF reading mode. To control.

  As shown in FIG. 3, the scanner mechanism 60 automatically transports the document S set on the ADF insertion tray 26 to the opening 22 c facing the ADF reading area 34 and discharges it to the ADF discharge tray 28. A light source unit 71 that irradiates light to the FB reading area 32 or the ADF reading area 34, a CIS 74 that receives reflected light from the original S and stores it as charges, and a light source unit 71 and the CIS 74. And a moving mechanism 77 that reciprocates the carriage 76 in the sub-scanning direction by driving the belt 79 spanned between the carriage motor 78a and the driven roller 78b by the carriage motor 78a. Further, the ADF insertion tray 26 is attached to the upper surface side of the housing cover 22 and, as shown in FIG. 1, a fixed guide 29a used for alignment in the width direction of the document S to be set, and the document S to be set. And a guide 29 that guides an edge in a direction (arrow direction in the figure) perpendicular to the conveyance (insertion) direction of the document S is attached. Therefore, in the ADF unit 61, the document S is automatically conveyed with the guide by the guide 29. The ADF unit 61 can transport a plurality of types of originals. In the present embodiment, description will be made assuming that three types of originals of A3 size, B4 size, and A4 size can be transported. .

  As shown in FIG. 2, the light source unit 71 has three color light sources: a red LED 72R that turns on red light, a green LED 72G that turns on green light, and a blue LED 72B that turns on blue light. Is irradiated onto the FB reading area 32 or the ADF reading area 34 through the light guide 73. As shown in the enlarged view of FIG. 2, the CIS 74 includes a plurality of sensor chips 75 in which a plurality of light receiving elements (for example, CMOS image sensors) 75 a for one line are arranged in the main scanning direction. The color image data is generated by reading the reflected light one by one while sequentially switching the lighting of the LEDs 72R, 72G, 72B of the respective colors.

  As shown in FIG. 3, the ADF unit 61 is disposed in the vicinity of the pickup roller 63 disposed in the vicinity of the ADF insertion tray 26, the plurality of transport rollers 64 disposed in the transport path 62, and the ADF discharge tray 28. A paper discharge roller 65 is provided. In the ADF unit 61, the rollers 63, 64, 65 are rotationally driven by the transport motor 66, so that the documents S set on the ADF insertion tray 26 are taken one by one and automatically transported on the transport path 62. Paper is discharged to the ADF paper discharge tray 28.

  In addition, the ADF unit 61 includes an interlocking mechanism 82 that is fixed to the lower side of the movable guide 29b, and a displacement member 84 that is fixed to the lower side of the interlocking mechanism 82. The outline of the structure of the interlocking mechanism 82 and the displacement member 84 is shown in FIGS. FIG. 4 schematically shows the configuration of the interlocking mechanism 82 and the displacement member 84 when the insertion tray 26 is viewed from above. 5 shows an outline of the configuration when viewed from the left side in FIG. 4, and the enlarged view in FIG. 5 shows the interlocking mechanism 82 and the displacement member 84 in three dimensions. 4 and 5, the configuration necessary for explaining the positional relationship between the interlocking mechanism 82 and the displacement member 84 is shown together. As shown in the figure, the interlock mechanism 82 is attached to the lower surface of the movable guide 29b and extends from the attachment portion in the main scanning direction, and the displacement member attachment is attached to the upper surface of the displacement member 84 and extends vertically upward from the attachment portion. It is comprised from the part 82b and the connection part 82c which is arrange | positioned along the subscanning direction and connects the guide attachment part 82a and the displacement member attachment part 82b. The interlocking mechanism 82 may be joined as an integral member (mechanism) after the portions 82a to 82c are formed as individual members, or may be formed as an integral member from the beginning. The displacement member 84 is configured as a white flat plate member, and three black marks 84a are formed on the lower surface thereof. Here, as shown in FIG. 2, an opening 22 b is formed between the document presser 22 a and the opening 22 c of the housing cover 22. The displacement member 84 is configured to move along the lower surface of the housing cover 22 on the opening 22b. The casing 21 is formed with a detection region 38 in which a glass plate is disposed at a position facing the opening 22b when the casing cover 22 is closed. For this reason, when the housing cover 22 is in the closed state, the respective portions 82a to 82c of the interlocking mechanism 82 are integrally interlocked with the sliding operation of the movable guide 29b, whereby the displacement member 84 is moved. Thus, the position changes on the opening 22b, that is, on the detection region 38. As shown in FIG. 2, the detection area 38 is formed between the ADF reading area 34 and the FB reading area 32 in the sub-scanning direction, and the carriage 76 is moved to the detection area 38 by the moving mechanism 77. The detection area 38 can be read by the CIS 74 by moving to the opposite position.

  Here, the state of displacement of the displacement member 84 accompanying the slide operation of the movable guide 29b will be described. FIG. 6 is an explanatory diagram showing the displacement of the displacement member 84 accompanying the sliding of the movable guide 29b. FIG. 6A shows the displacement of the displacement member 84 when the A3 size document S is set on the ADF insertion tray 26. Similarly, FIG. 6B shows the displacement when the B4 size document S is set, and FIG. 6C shows the displacement when the A4 size document S is set. As shown in the drawing, the number of marks 84 a located on the detection region 38 among the three marks 84 a formed on the lower surface of the displacement member 84 differs depending on the size of the document S. As described above, in the present embodiment, when the movable guide 29b is slid according to the widths of the three types of documents S, the number of marks 84a positioned on the detection area 38 is different. The interlocking mechanism 82 is configured as described above.

  As shown in FIG. 3, the scanner ASIC 51 includes a control circuit 52 that controls each device, an LED drive circuit 54 that individually turns on / off the LEDs 72R, 72G, and 72B, and an analog signal generated by the CIS 74 via an amplifier (not shown). And an A / D converter 56 that receives the control signal from the control circuit 52, and a motor drive circuit 58 that drives the carriage motor 78a and the transport motor 66.

  The memory card controller 44 inputs / outputs data to / from the memory card MC inserted into the memory card slot 44a disposed at the lower right in FIG. The memory card controller 44 reads a file stored in the memory card MC and transmits it to the main controller 90 or inputs a command from the main controller 90 when the memory card MC is inserted in the memory card slot 44a. Then, data is written to the memory card MC based on the command.

  As shown in FIG. 1, the operation panel 45 includes a display unit 46 disposed in the center of the housing 21 and a power button 47 disposed on the left side of the display unit 46. The display unit 46 is configured as a touch panel type liquid crystal display, and displays a mode button for selecting a mode, a selection / setting button for selecting / setting various items, a start button for starting copying and printing, and the like. Touch operation can be accepted. Here, as modes selectable by the mode selection button, a copy mode for scanning and copying a document, a scan mode for scanning a document and converting it into data, and saving it in the memory card MC, and an image stored in the memory card MC are used. Print mode.

  The main controller 90 is configured as a microprocessor centered on a CPU 92, and includes a ROM 94 that stores various processing programs, various data, various tables, a RAM 96 that temporarily stores scan data and print data, and an operation panel. And an interface (I / F) 98 that enables communication with the network 45. The main controller 90 inputs various operation signals and various detection signals from the printer unit 40 and the scanner unit 50, and inputs operation signals generated in response to touch operations on the operation panel 45. Further, a command for reading an image file from the memory card MC and outputting it to the main controller 90 is outputted to the memory card controller 44, a command is outputted to the printer unit 40 to execute printing of image data, and the operation panel 45 is used. Based on the scan command, a command is output to the scanner unit 40 to read the document placed on the FB reading area 32 or the document S set on the ADF insertion tray 26 as image data, or the display unit 46 is displayed on the operation panel 45. Output control commands. Here, in the present embodiment, as described above, the number of the marks 84a of the displacement member 84 positioned on the detection region 38 differs depending on the slide of the movable guide 29b. The correspondence table 94a that defines the relationship between the number of the documents and the size information of the document S is stored in the ROM 94 in advance. FIG. 7 is an explanatory diagram illustrating an example of the correspondence table 94a.

  Next, an operation of the thus configured multifunction printer 20 of the present embodiment, particularly an operation when determining the size of the document S prior to scanning in the ADF reading mode will be described. FIG. 8 is a flowchart showing an example of a document size determination processing routine executed by the main controller 90. This process is executed, for example, when the copy mode or the scan mode is selected by the mode selection button and the start button is touched while the document S is set on the ADF insertion tray 26.

  When the document size determination processing routine is executed, the CPU 92 of the main controller 90 first drives and controls the carriage motor 78a so that the carriage 76 moves to the size determination processing position (step S100). Here, the size determination processing position is determined as a position where the detection area 38 can be read by the CIS 74. When the carriage 76 moves to the size determination processing position, a scan process is executed (step S110), and the number of marks 84a is detected based on the change in output voltage obtained by each light receiving element 75a of the CIS 74 (step S120). Here, in the present embodiment, since the black mark 84a is formed on the white displacement member 84, the output voltage greatly changes at the edge portion of the mark 84a. Therefore, the number of marks can be detected by binarizing the output voltage and counting the change points. Based on the detected number of marks, the correspondence size table 94a stored in the ROM 94 is referred to determine the document size (step S130), and this routine is terminated. Accordingly, the size of the document S set on the ADF insertion tray 26 of the ADF unit 61 can be determined, and the document S is read by setting a reading area based on the determined size of the document S. Thus, since the document size is determined based on the number of marks 84a located on the detection area 38 among the three marks 84a formed on the displacement member 84, the ADF unit is used to determine the size of the document S. There is no need to provide a dedicated sensor in 61, and the number of sensors can be reduced. For this reason, the number of input ports required for the main controller 90 can be reduced, and resource consumption can be suppressed. Further, since the document size is determined by referring to the correspondence table 94a previously stored in the ROM 94 based on the detected number of marks, the size can be easily determined. Further, since the detection area 38 is formed between the ADF reading area 34 and the FB reading area 32 in the sub-scanning direction, the amount of movement of the carriage 76 for the determination of the document size is relatively small, and smooth. The document size can be determined.

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The ADF unit 61 of this embodiment corresponds to the “automatic transport mechanism” of the present invention, the carriage 76 on which the light source unit 71 and the CIS 74 as the reading unit are mounted corresponds to “reading means” of the present invention, and the movable guide 29 b is Corresponding to “edge guide”, interlocking mechanism 82 corresponds to “interlocking mechanism”, displacement member 84 corresponds to “displacement member”, and ROM 94 storing correspondence table 94a corresponds to “storage means”. The main controller 90 that executes the document size determination processing routine No. 8 corresponds to “document size determination means”.

  According to the multifunction printer 20 of the present embodiment described above, the movable guide 29b provided on the ADF insertion tray 26 of the ADF unit 61 so as to be slidable, and the movable guide 29b fixed to the lower surface of the movable guide 29b. An interlocking mechanism 82 that interlocks with the slide, and a displacement member 84 that is fixed to the lower surface of the interlocking mechanism 82 and that has three marks 84 a formed on the surface facing the detection region 38 formed on the housing 21. The correspondence relationship between the size information of the three types of documents and the output patterns of the plurality of light receiving elements 75a of the CIS 74 is stored in advance in the ROM 94 as the correspondence table 94a, and the CIS 74 is controlled so as to read the detection area 38. Based on the output pattern of the plurality of light receiving elements 75a obtained by reading and the correspondence table 94a. Determining the size of the set document S. Thus, the size of the document can be determined using the document reading sensor without using a dedicated sensor. Also, the document size can be easily determined based on the detected number of marks. Further, since the detection area 38 is formed between the ADF reading area 34 and the FB reading area 32 in the sub-scanning direction, the amount of movement of the carriage 76 can be relatively reduced and the document size can be determined smoothly. it can. In addition, since the detection area 38 is an area different from the ADF reading area 34 and the FB reading area 32, the displacement member 84 can be used for the ADF reading area 34 and the FB reading area in both cases of ADF reading and FB reading. Since it does not exist in 32, it does not become an obstacle at the time of reading.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  In the above-described embodiment, the ADF unit 61 is capable of automatically transporting three types of documents S of A3 size, B4 size, and A4 size. However, the present invention is not limited to this, and automatic processing of a document S of B5 size or A5 size is possible. It is good also as what can be conveyed. In addition, the number of types that can be transported is not limited to three, and may be two types or four or more types. In that case, the number of marks 184 a corresponding to the number of types that can be transported is formed on the displacement member 184. It should be.

  In the above-described embodiment, three marks 84a are formed on the displacement member 84, and the number of marks positioned on the detection area 38 is detected to determine the document size. However, the present invention is not limited to this. Any method may be used as long as it detects 84 displacement states and determines the document size based on the detected displacement state. For example, the displacement member 84 is formed in white and the member located behind it is formed in black, and the edge position of the tip of the displacement member 84 is detected and detected as a displacement on the detection region 38 of the displacement member 84. The document size may be determined based on the edge position of the leading edge. In this case, instead of the correspondence table 94a that defines the relationship between the number of marks and the document size, a correspondence table that defines the relationship between the edge position of the tip of the displacement member 184 and the document size is stored in the ROM 94. And so on. In this way, the size of the document can be easily determined from the edge position of the tip of the displacement member obtained by reading.

  In the above-described embodiment, the sliding operation of the movable guide 29b is transmitted to the displacement member 84 via the interlocking mechanism 82 integrally formed by the members 82a to 82c. However, the present invention is not limited to this, and the movable guide 29b is not limited thereto. Any structure may be used as long as it can mechanically transmit the sliding motion to the displacement member 84, and for example, it may be transmitted via a gear mechanism. A schematic configuration of the interlocking mechanism 182 and the displacement member 184 of the modified example in this case is shown in FIG. FIG. 9A shows an outline of the configuration of the interlocking mechanism 182 and the displacement member 184 when the insertion tray 26 is viewed from the upper side, and shows an image of the positional relationship with the CIS 74. FIG. The outline of a structure at the time of seeing the interlocking mechanism 182 and the displacement member 184 from the lower side in FIG. In FIG. 9, the same components as those of the present embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in the figure, the interlocking mechanism 182 is attached to the lower surface of the movable guide 29b and extends from the mounting portion in the main scanning direction to form a first rack gear 182b on the side surface and a first rack gear 182b. The meshing first pinion gear 182c, the first pinion gear 182c and the second pinion gear 182e arranged coaxially via the shaft 182d, and the upper surface of the displacement member 184 are extended from the mounting portion to the guide mounting portion 182a side. And a displacement member mounting portion 182g on which a second rack gear 182f meshing with the second pinion gear 182e is formed. In the interlock mechanism 182, the first rack gear 182 b (guide mounting portion 182 a) moves as the movable guide 29 b slides to rotate the first pinion gear 182 c, and the first pinion gear 182 c rotates as the first pinion gear 182 c rotates. The second pinion gear 182e rotates and the second rack gear 182f (displacement member mounting portion 182g) moves in the direction opposite to the slide of the movable guide 29b. Thereby, the displacement member 184 moves with the slide of the movable guide 29b. The second rack gear 182f (displacement member mounting portion 182g) may be moved in the same direction as the slide of the movable guide 29b by providing two second pinion gears 182e. Here, the area that can be read by the plurality of light receiving elements 75a of the CIS 74 is formed by an effective area formed from the light receiving elements 75a used for reading a document and light receiving elements 75a positioned outside both ends of the effective area. It is divided into non-effective areas. In this modification, the interlock mechanism 182 moves so that the leading edge 184a of the displacement member 184 moves within the range in the main scanning direction of the detection region 138 in which the glass plate is disposed to face one of the ineffective areas. It is configured. For example, when the CIS 74 reads the document S with a resolution of 1200 dpi and about 120 light receiving elements 75a are arranged in the ineffective area, the length of the ineffective area in the main scanning direction is about 2 to 3 mm. It becomes. On the other hand, the slide amount of the movable guide 29b is required to be about 90 mm from the difference between the A3 size document width of 297 mm and the A4 size document width of 210 mm. From these facts, in order to keep the displacement of the leading edge 184a of the displacement member 184 within the detection region 138, the reduction ratio between the first pinion gear 182c and the second pinion gear 182d is set to 1/30 to 1 /. It may be set to a value such as 40. In this modification, the correspondence table that defines the relationship between the position of the leading edge 184a of the displacement member 184 and the document size is stored in the ROM 94 in advance. In addition, since the reading position of the CIS 74 (carriage 76) in the ADF reading mode is below the ADF reading area 34 and the detection area 138, it is not necessary to move the CIS 74 in order to determine the size of the document S. For this reason, in this modification, the document size may be determined by omitting the processing in step S100 of the document size determination processing routine shown in FIG. 8, and the document is detected using the light receiving element 75a in the ineffective area. The size can be determined efficiently. As in the present embodiment, the determination may be made by forming three marks on the lower surface of the displacement member 184. Further, when the document size is determined using the ineffective area, a gear mechanism having a reduction ratio as in this modification may not be provided. However, in this case, it is necessary to secure an ineffective area corresponding to the moving amount of the displacement member 184, that is, the sliding amount of the movable guide 29b.

  In the embodiment described above, one of the two guides included in the guide 29 is a non-slidable fixed guide 29a and the other is a slidable movable guide 29b. However, the present invention is not limited to this, and both may be slidable. .

  In the above-described embodiment, the LEDs 72R, 72G, and 72B are used as the light source unit 51. However, the present invention is not limited to this, and a white LED may be used as the light source unit, or as the light source unit. A fluorescent lamp may be used, and light may be guided to the sensor by a mirror or a lens. The light receiving unit may also use a CCD image sensor instead of the CIS 74.

  In the above-described embodiment, the present invention is applied to the multi-function printer 20 having a printer function in addition to the scanner function. However, the present invention may be applied to a single scanner machine that does not have a printer function. The present invention may be applied to a device having a FAX function.

  20 Multifunction Printer, 21 Case, 22 Case Cover, 22a Document Press, 22b, 22c Opening, 23 Cassette, 24 Output Tray, 26 ADF Insertion Tray, 28 ADF Output Tray, 29 Guide, 29a Fixed Guide, 29b Movable guide, 32 FB reading area, 34 ADF reading area, 36 White reference plate, 38, 138 Detection area, 40 Printer unit, 41 Printer ASIC, 42 Printer mechanism, 44 Memory card controller, 44a Memory card slot, 45 operation Panel, 46 Display, 47 Power button, 50 Scanner unit, 51 Scanner ASIC, 52 Control circuit, 54 LED drive circuit, 56 A / D converter, 58 Motor drive circuit, 60 Scanner mechanism, 61 Auto document feeder (ADF) unit, 62 transport path, 63 pickup roller, 64 transport roller, 65 paper discharge roller, 66 transport motor, 71 light source unit, 72R, 72G, 72B LED, 73 light guide, 74 CIS, 75 Sensor chip, 75a Light receiving element, 76 carriage, 77 moving mechanism, 78a carriage motor, 78b driven roller, 79 belt, 82 interlocking mechanism, 82a guide mounting portion, 82b displacement member mounting portion, 82c connecting portion, 84 displacement member, 84a mark 90 main controller, 92 CPU, 94 ROM, 94a correspondence table, 96 RAM, 98 interface (I / F), 182 interlocking mechanism, 182a guide mounting portion, 182b first rack gear, 182c First pinion gear, 182d shaft, 182e Second pinion gear, 182f Second rack gear, 182g Displacement member mounting portion, 184 Displacement member, 184a Tip edge, MC memory card, S document.

Claims (7)

An insertion section into which a document is inserted;
An automatic transport mechanism for automatically transporting a document set in the insertion portion;
A first unit for reading a document automatically conveyed by using the reading unit having a reading unit in which a plurality of photoelectric conversion elements are arranged in the main scanning direction is different from the first region. Reading means capable of reading the two areas;
An edge guide that guides an edge perpendicular to the conveyance direction of the document that is provided in the insertion portion so as to be slidable and automatically conveyed;
An interlocking mechanism that mechanically interlocks with the slide of the edge guide;
A displacement member that is attached to the interlocking mechanism and moves along with the interlocking of the interlocking mechanism and changes its position on the second region;
Storage means for storing correspondence information between size information for each size of the plurality of types of documents and output patterns of the plurality of elements;
A document size determining unit that controls the reading unit to read the second region and determines the size of the set document based on output patterns of the plurality of elements obtained by the reading and the correspondence relationship; Document reading apparatus provided.   2. The document reading device according to claim 1, wherein the document is automatically conveyed by setting a reading range according to the size of the set document. In addition to reading an automatically conveyed document, an area formed in the upper part of the housing where a document can be placed and aligned in the sub-scanning direction with the first area is defined as a third area. The document reading device according to claim 1 or 2, wherein the document reading device is readable.
The automatic transport mechanism is a mechanism in which an insertion portion is formed on the upper surface side of the casing cover, which is incorporated in a casing cover that is attached to the upper portion of the casing so as to be openable and closable.
The displacement member is a member that is disposed on the lower surface side of the housing cover and moves along the lower surface of the housing cover in conjunction with the interlocking mechanism. The document reading device according to claim 3,
The second region is formed between the first region and the third region in the sub-scanning direction,
The displacement member is a member that moves in the main scanning direction over the second region when the housing cover is closed. The document reading apparatus according to any one of claims 1 to 3,
The reading unit has the plurality of elements arranged in the reading unit so as to be able to read an area having a margin in the main scanning direction with respect to the first area, and the plurality of elements read a document. Means for dividing the effective element to be performed and the ineffective element different from the effective element,
The first region is formed as a region facing the effective element,
The second region is formed as a region facing the ineffective element;
The displacement member is a member that moves in the main scanning direction on the second region when the housing cover is closed.
The interlocking mechanism is a mechanism having a speed reduction mechanism that transmits the slide of the edge guide to the displacement member with a speed reduction ratio such that a change in the position of the displacement member falls within the range of the second region. . The document reading device according to any one of claims 1 to 5,
The displacement member is a member in which a plurality of marks are formed on a surface facing the reading unit,
The interlocking mechanism is a mechanism that interlocks so that different numbers of marks are positioned on the second region according to the slide of the edge guide among the plurality of marks of the displacement member,
The storage means is means for storing, as the correspondence relationship, size information for each size of the plurality of types of documents and the number of marks located on the second region in association with each other,
The document size determining means is a means for determining the size of the document based on the number of marks on the displacement member obtained by reading the second area and the corresponding relationship. The document reading device according to any one of claims 1 to 5,
The storage means is means for storing, as the correspondence relationship, size information for each size of the plurality of types of documents and an edge position of the tip of the displacement member on the second region in association with each other,
The document size determining means is a means for determining the size of the document based on the edge position of the tip of the displacement member obtained by reading the second area and the corresponding relationship.

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