Document reader

Abstract

To provide a document reading device capable of automatically reading documents in various sizes including non-standard document sizes without missing document regions of the documents.SOLUTION: A document reading device comprises: a document size determination unit for determining whether a size of a placed document corresponds to which one of a plurality of standard sizes in a preliminary manner on a first stage on the basis of, document size information relating to a combination of a longitudinal length and a lateral length detected by a document size detection unit; and a document region determination unit. On a second stage after the first stage, the document size determination unit determines whether the size of the document is a standard size or a non-standard size on the basis of the standard size detected on the first stage and the document size information. The document region determination unit decides a reading region of the document in a mode different from a document determined as a standard size for a document which is determined as a non-standard size by the document size determination unit.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an original reading device capable of determining the size of an original and determining an original area. [Background technology]

[0002] Document reading devices such as multifunction peripherals and image scanners use two document reading modes: a mode in which a document placed on a document table is scanned (platen mode), and a mode in which a document is transported and read using a document feeder (feeder mode). In either mode, the document size is input or detected and only the document area is read. For this reason, many document reading devices have a function to detect the document size. Document sizes that can be detected by document reading devices are usually limited to so-called standard sizes such as A3, A4, A5, 11" x 17", 8.5" x 11", and 5.5" x 8.5". To read non-standard sizes (irregular sizes), a means is provided for manually inputting the length and width of the document.

[0003] Even if scanning irregular sized documents is rare, it is cumbersome to manually input the document size when doing so. If the accurate document size could be detected even for irregular sizes, this would be convenient as it would eliminate the need for cumbersome input. One way to accurately detect the size of an irregular document is to crop the area corresponding to the background color plate from the scanned document image, assuming that the background color plate is not a typical white color but a gray color instead. This assumes that the edges of a typical document are the same white as the base color of the paper, and determines the outline of the document based on the density difference between the white of the document edge and the gray of the background color plate. However, there is a downside to using a gray background plate: when scanning a document on light paper using a gray background plate, the gray of the background plate may show through to some extent, causing the document paper to be read as if it were a light gray.

[0004] The following techniques are known for detecting the document area of ​​a document in a document reading device. If the size of the document to be read cannot be identified (in the case of an irregular-sized document), the document is read in the maximum reading area, a cropping process is performed to cut out image data of the document from the obtained image data, and the cut-out image data of the document is converted into a file (for example, Patent Document 1). Furthermore, if the user repeatedly repositions the document or has difficulty determining the detected document size, the system determines that the detected document size may be incorrect and displays a manual size setting screen or a destination setting screen to prompt the user to perform an operation (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-36891 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-222764 Summary of the Invention [Problem to be solved by the invention]

[0006] In the case of Patent Document 1, the memory capacity required is large and the cropping process takes time. Furthermore, in the case of Patent Document 2, the user must manually input the document size, which is cumbersome. The present invention has been made in consideration of the above circumstances, and provides a document reading device that can automatically read documents of various sizes, including irregular document sizes, without missing any document area. [Means for solving the problem]

[0007] This invention (first invention) is a document reading unit that reads a document; a document transport unit configured to transport a document placed on the document in a document transport direction toward the document reading unit; a storage unit that stores in advance standard sizes relating to the long side length and short side length of each of a plurality of standard size documents; a document size detection unit that detects a vertical length of the document placed along the document transport direction and a horizontal length of the document in a direction perpendicular to the document transport direction; an original size determination unit that preliminarily determines in a first stage which of a plurality of standard sizes the size of the placed original corresponds to based on original size information relating to the combination of the vertical length and horizontal length detected by the original size detection unit; a document area determination unit; the document size determination unit determines, in a second stage after the first stage, whether the document size is a standard size or an irregular size based on the standard size determined in the first stage and the document size information; The document reading device provides a document reading device in which the document area determining section determines a reading area for a document determined by the document size determining section to be of an irregular size in a mode different from that for a document determined to be of a regular size.

[0008] In addition, this invention (second invention) is a document reading unit that reads a document; a document transport unit configured to transport a document placed on the document in a document transport direction toward the document reading unit; a storage unit that stores in advance the vertical and horizontal lengths of each of a plurality of standard sizes related to documents; a document size detection unit that detects a vertical length of the document placed along the document transport direction and a horizontal length of the document in a direction perpendicular to the document transport direction; a document size determination unit that determines the size of the document; a document area determination unit; The storage unit stores the length and width of each standard size in increments of 1 or more, the document size detection unit detects the length of at least one of the vertical length and the horizontal length of the document in increments greater than the number of types of the standard sizes; the document size determination unit determines whether the size of the placed document corresponds to one of the standard sizes or an irregular size that does not correspond to any of the standard sizes, based on document size detection information relating to the combination of the vertical length and the horizontal length detected by the document size detection unit; The document reading device provides a document reading device in which the document area determining section determines a reading area for a document determined by the document size determining section to be of an irregular size in a mode different from that for a document determined to be of a regular size. [Effects of the Invention]

[0009] The document reading device according to the first and second aspects of the present invention can automatically read documents of various sizes, including irregular sizes, without missing any images. When documents are irregular sizes, the reading time, memory capacity, and cropping time can be reduced compared to a method of reading documents in the maximum reading area. Furthermore, manual document size input by the user can be omitted, even for documents of irregular sizes. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a part of the exterior of a multifunction peripheral as one aspect of a document reading device according to this embodiment (in a state where a document transport unit is closed). [Figure 2] 1 is a perspective view showing a part of the exterior of a multifunction peripheral as one aspect of a document reading device according to this embodiment (in a state where a document transport unit is open). [Figure 3] FIG. 3 is a block diagram showing the overall configuration of the multifunction peripheral shown in FIGS. 1 and 2. [Figure 4] 2 is an explanatory diagram showing a schematic configuration of a document reading unit and a document transport unit in the document reading device of the multifunction peripheral shown in FIG. 1. FIG. [Figure 5] 2 is a perspective view showing a schematic configuration of a document reading unit in a document reading device of the multifunction peripheral shown in FIG. 1. FIG. [Figure 6] 2 is a plan view of the document reading device of the multifunction peripheral shown in FIG. 1. [Figure 7] FIG. 10 is a diagram showing document size information of main standard-sized documents. [Figure 8]10 is an explanatory diagram illustrating a case where the distance between the document guides is equal to the width of the document. FIG. [Figure 9] FIG. 10 is a first explanatory diagram when the distance between the document guides is wider than the horizontal length of the document. [Figure 10] FIG. 10 is a second explanatory diagram illustrating a case where the distance between the document guides is wider than the horizontal length of the document. [Figure 11] FIG. 10 is a first explanatory diagram illustrating a case where the distance between the document guides is narrower than the horizontal length of the document. [Figure 12] FIG. 10 is a second explanatory diagram illustrating a case where the distance between the document guides is narrower than the horizontal length of the document. [Figure 13A] 10A and 10B are explanatory diagrams showing examples of document detection size tables relating to various standard document sizes; [Figure 13B] FIG. 10 is an explanatory diagram showing the horizontal lengths (reference widths) in the orthogonal direction for various standard-sized documents. [Figure 14] 5 is a flowchart showing a document reading process executed by a control unit in the first embodiment. [Figure 15A] FIG. 10 is an explanatory diagram showing an example of a document detection size table for AB-type standard documents. [Figure 15B] FIG. 10 is an explanatory diagram showing an example of a document detection size table for standard-sized documents in the INCH system; [Figure 16A] FIG. 10 is an explanatory diagram showing the horizontal length (reference value) in the orthogonal direction of an AB-type standard document. [Figure 16B] FIG. 10 is an explanatory diagram showing the horizontal length (reference value) in the orthogonal direction of an INCH-based standard document. [Figure 17] 10 is a flowchart showing a document reading process executed by a control unit in a second embodiment. [Figure 18] 11 is a flowchart showing a document reading process executed by a control unit in a third embodiment. [Figure 19] 10 is a flowchart showing a document reading process executed by a control unit in a fourth embodiment. [Figure 20] 13 is a flowchart showing a document reading process executed by a control unit in a fifth embodiment. [Figure 21A]13 shows a first example of a user setting screen displayed on a display device in the fifth embodiment. [Figure 21B] 13 shows a second example of a user setting screen displayed on a display device in the fifth embodiment. [Figure 21C] 13 shows a third example of a user setting screen displayed on a display device in the fifth embodiment. [Figure 22] 13 is a flowchart showing a document reading process executed by a control unit in a sixth embodiment. [Figure 23A] 13 shows a first example of a user setting screen displayed on a display device in the sixth embodiment. [Figure 23B] 13 shows a second example of a user setting screen displayed on a display device in the sixth embodiment. [Figure 23C] 13 shows a third example of a user setting screen displayed on a display device in the sixth embodiment. [Figure 23D] 13 shows a fourth example of a user setting screen displayed on a display device in the sixth embodiment. [Figure 23E] 13 shows a fifth example of a user setting screen displayed on a display device in the sixth embodiment. [Figure 24] 13 is a flowchart showing a document reading process executed by a control unit in the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in more detail below with reference to the accompanying drawings. Note that the following description is given by way of example only in all respects and should not be construed as limiting the present invention.

[0012] (First embodiment) <Configuration of document reading device> First, the document reading device in this embodiment will be described. 1 and 2 are perspective views showing a part of the exterior of a multifunction peripheral as one aspect of a document reading device in this embodiment. The parts related to document reading are shown. FIG. 1 shows a state in which the document transport unit is closed, and FIG. 2 shows a state in which the document transport unit is open and the document table is exposed. FIG. 3 is a block diagram showing the overall configuration of the multifunction peripheral shown in FIGS. 1 and 2. As shown in the block diagram of Figure 3, the multifunction device 100 includes a control unit 11, a document reading device 12, a storage device 13 as a storage unit, an image forming unit 14 as an image forming unit, a user interface unit 19 (also referred to as a UI unit), a communication circuit 21, and an image processing circuit 40.

[0013] The control unit 11 includes a UI control unit 11U, a file control unit 11F, a job management unit 11J, a job execution unit 11X, an image processing control unit 11P, a communication control unit 11C, and a reading control unit 11S. The control unit 11 controls the multifunction peripheral 100. The document reading device 12 includes a scanner unit 15 as a document reading section that reads a document, a document feeder 16 as a document transport section, and a document size detection section 10 . The UI unit 19 includes an operation input device 19I such as a touch panel, and a display device 19D as a display unit. The image processing circuit 40 includes an input processing circuit 41 , a document area determination circuit 45 as a document area determination unit, and an output image generation circuit 47 .

[0014] As shown in FIG. 1, the UI unit 19 is provided on the housing of the multifunction peripheral 100. The operation input device 19I detects user operations on the display screen of the display device 19D. The display device 19D is configured, for example, with a liquid crystal display device, and displays a screen according to the control of the UI control unit 11U. The UI control unit 11U recognizes the operation signal detected by the operation input device 19I and recognizes which element on the screen displayed on the display device 19D has been operated. The file control unit 11F saves and reads files to and from a storage device such as a HDD, and loads files into a storage device such as a memory.

[0015] The job management unit 11J performs processes for registering, deleting, and stopping various jobs such as copy jobs, scanner jobs, print jobs, etc. When a job registered in the job management unit 11J becomes executable, the job management unit 11J requests the job execution unit 11X to start executing the job. The job execution unit 11X determines whether or not to start execution of a job registered by the job management unit 11J, and causes the image forming unit 14, the scanner unit 15, and the image processing circuit 40 to execute the job according to the settings. The job execution unit 11X recognizes the states detected by sensors (not shown) arranged in the scanner unit 15 and the image forming unit 14. Then, it controls the operation of motors, actuators, devices (not shown) arranged in the scanner unit 15 and the image forming unit 14. In addition, the image processing control unit 11P controls image-related processing in the image processing circuit 40. Then, it executes job-related processing such as reading, printing, and previewing the image of the document. The reading control unit 11S controls the document area determination circuit 45 so that in a mode for reading standard sizes, a predetermined area corresponding to each standard size is used as the reading area, and in a mode for reading irregular sizes, the document area determination circuit 45 determines the document boundary from the image obtained by reading the document and cuts out the document area. Furthermore, the reading control unit 11S preliminarily determines in a first stage whether the size of the placed document corresponds to one of multiple standard sizes based on document size information relating to the combination of the document's length and width detected by the document size detection unit 10. That is, in the first stage, a determination is made to associate the document size detected by the document size detection unit 10 with one of the standard sizes. Furthermore, in a second stage following the first stage, the reading control unit 11S determines whether the document size is a standard size or an irregular size based on the standard size determined in the first stage and the document size information. The document size detection unit 10 detects the length of at least one of the document's length and width in increments greater than the number of standard sizes. In this embodiment, the document guide 10a, which detects the document's width, detects the width in increments greater than the number of detectable standard sizes (e.g., in 0.1 mm increments). For example, if there is a difference between the horizontal length of the standard size linked in the first stage and the horizontal length of the document detected by the document guide 10a that exceeds a predetermined tolerance range, the document is determined to be of an irregular size.

[0016] As a specific configuration, the control unit 11 is mainly composed of a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). In addition to the processor, it is also composed of hardware resources such as a work memory, an input / output interface circuit, and a timer circuit. The processor executes a control program pre-stored in the storage device 13, thereby performing various jobs related to operation recognition, display control, reading of document images, image printing, etc., i.e., a series of processes related to image formation. The software resources and hardware resources work together to realize the functions of the control unit 11.

[0017] The storage device 13 includes volatile memory such as DRAM and non-volatile memory such as HDD or flash memory. The storage device 13 stores control programs executed by the processor and images read by the scanner unit 15 and processed by the image processing circuit 40. It also stores data related to the control of the file control unit 11F, job management unit 11J, job execution unit 11X, and image processing control unit 11P. The storage device 13 also stores in advance standard sizes (described in detail below) related to the long and short side lengths of each of a plurality of standard-sized originals. The storage device 13 may be integrated with the memory of the control unit 11.

[0018] The control unit 11 and the image forming unit 14 are connected so as to be able to transfer data, and the control unit 11 and the scanner unit 15 are connected so as to be able to transfer data. The communication circuit 21 is a circuit for communicating data with external devices via a network. As shown in Figures 1 and 2, the multifunction device 100 has a document feeder (document transport section) 16 on the image forming unit 14, which places a document on the document and transports the document in a document transport direction A (see Figure 6) toward the scanner unit (document reading section) 15. The multifunction device 100 also includes a document table 17 in the image forming unit 14 that is exposed when the document feeder 16 is opened upward. The document table 17 is made of a transparent glass plate and is located on the top surface of the scanner unit 15. As shown in FIG. 2, a front side reading window 18 is located next to the left end of the document table 17. The front side reading window 18 is also made of a transparent glass plate, just like the document table 17. A front side background color plate 51 is located on the underside of the document feeder 16. When the document feeder 16 is closed, the front side reading window 18 and the front side background color plate 51 are positioned opposite each other.

[0019] The scanner unit 15 reads an image of a document under the control of the job execution unit 11X and converts it into an RGB (red, green, and blue) color image signal (RGB analog signal). That is, it executes image reading processing for copy, fax, and scanner jobs. FIG. 4 is an explanatory diagram showing a schematic configuration of the scanner unit 15 and the document feeder 16 of the multifunction peripheral 100 shown in FIG.

[0020] 1 and 4 separates and feeds documents one by one from a stack of documents placed on a document set tray 31 (see arrow IN in FIG. 4), transports the documents via front-side reading positions R1 and R2 and back-side reading position R3, and discharges them onto a document discharge tray 33 (see arrow OUT in FIG. 4). Note that the documents are set on the document set tray 31 with their front sides facing up. This makes it possible to switch between reading positions R1 and R2 in a mode in which only one side (front side) of a document is read. The front side reading positions R1 and R2 are located between the lower front side reading window 18 and the upper front side background color plate 51. The transported document is exposed below the front side background color plate 51 at the reading positions R1 and R2.

[0021] As shown in Figures 4 and 5, the scanner unit 15 stops the first carriage 55 at either reading position R1 or R2 and reads the front side of a document that passes through it. The first carriage 55 is equipped with an LED and a reflective mirror that illuminates the document surface, and the second carriage 57 is equipped with two reflective mirrors. The image of the document passing through reading position R1 or R2 is formed on an image sensor 61 via the reflective mirrors and an optical lens 59. The first carriage 55 is movable along the document table 17 (see arrow S in Figures 4 and 5). In platen mode, the first carriage 55 scans and reads the document placed on the document table 17 from below, as indicated by arrow S in Figure 4. The second carriage 57 moves in the same direction as the first carriage 55 at half the speed, forming an image of the document placed on the document table 17 on the image sensor 61. The image sensor outputs an image signal corresponding to the document image. The reflecting mirrors of the first carriage 55 and the second carriage 57 and the optical lens 59 constitute a reduction optical system that forms an image of the front side of the document on the image sensor 61 .

[0022] FIG. 5 is an explanatory diagram showing the configuration of a mechanism for moving the first carriage 55 and the second carriage 57 of the scanner unit 15 shown in FIG. 4. FIG. 5 is a perspective view of the scanner unit 15, viewed diagonally from above and rear on the left side. As shown in FIG. 5, a wire is fixed to both ends of the first carriage 55. The second carriage 57 has pulleys on both ends around which the wire is wound. The wire is wound around a wire pulley 65 that is driven to rotate by a scanner motor 63. As the wire pulley 65 rotates, the first carriage 55 and the second carriage 57 move in the direction of arrow S and then in the opposite direction. The second carriage moves at half the speed of the first carriage, like a movable pulley.

[0023] FIG. 6 is a plan view of the document reading device of the multifunction peripheral shown in FIG. As shown in Figure 6, on the document set tray 31 of the document feeder 16, there is provided a document size detection unit 10 that detects the vertical length of the document D placed on the document set tray 31 along the document transport direction A and the horizontal length in a direction B (hereinafter referred to as the orthogonal direction B) perpendicular to the document transport direction A (see Figure 3). In this embodiment, the document size detection unit 10 includes a length detection unit that detects the vertical length of the document D (document transport direction A) and a width detection unit that detects the horizontal length of the document D (orthogonal direction B). When the document D is placed on the document set tray 31 with its longitudinal direction aligned with the document transport direction A, the vertical length of the document D is the long side length, and the horizontal length is the short side length. When the document D is placed on the document set tray 31 with its longitudinal direction aligned with the orthogonal direction B, the vertical length of the document D is the short side length, and the horizontal length is the long side length.

[0024] The horizontal length detection section of the document size detection section 10 is composed of a pair of document guides 10a arranged on the document set tray 31 so as to be movable in the perpendicular direction B, a pair of parallel slide members (not shown) arranged slidably in grooves in the perpendicular direction B provided in the document set tray 31 so as to connect with the pair of document guides 10a, toothed surface portions (rack portions) not shown arranged on each of the pair of parallel slide members, gear members (pinion portions) not shown rotatably arranged between the toothed surface portions of the pair of parallel slide members and meshing with each toothed surface portion, and an encoder not shown that measures the movement distance of one of the slide members. The pair of document guides 10a are wall-shaped guide plates that extend along the document transport direction A and rise vertically from the upper surface of the document set tray 31. The pair of parallel slide members are rod-shaped members extending along the perpendicular direction B and arranged side by side in the document transport direction A with a gear member (pinion portion) sandwiched between them, and each rod-shaped member has a toothed surface portion (rack portion) on the opposing surface.

[0025] According to this width detection unit, a pair of document guides 10a, which face each other across a center line C in the orthogonal direction B on the document set tray 31, move toward or away from each other at equal distances from the center line C in the direction B. At this time, the distance between the pair of document guides 10a is detected in increments of 0.1 mm, for example, by measuring the movement distance of one of the slide members with an encoder. Therefore, by placing a document D on the document set tray 31 and moving the pair of document guides 10a to the position of a pair of opposing sides of the document D (a pair of long sides of the document D in the case of FIG. 6), the width of the document D in the orthogonal direction B (the length of the short sides of the document D in the case of FIG. 6) is detected. This will be described in detail later.

[0026] The length detection section of the document size detection unit 10 includes a first sensor 10ba and a second sensor 10bb embedded on the center line C of the document set tray 31 at a predetermined distance L1 and a predetermined distance L2 from the document set position P. In this embodiment, the first sensor 10ba and the second sensor 10bb are reflective photosensors having an integrated light-emitting section and light-receiving section, but they are not limited to this and may also be contact-type sensors that detect the document by physically coming into contact with it. In this embodiment, the distance L1 is set to 232 mm and the distance L2 is set to 305 mm, which will be described in detail later. Furthermore, on the center line C of the document set tray 31 and near the document set position P, a document sensor 10bc is provided to detect the document D set on the document set tray 31. This document sensor 10bc may also be a reflective photosensor, a contact sensor, or the like. A cover member 32 is provided above the document set position P and the document sensor 10bc.

[0027] Returning to the explanation of Figure 4, a back side reading unit 67 that reads the back side of the document and a back side background color plate 53 are arranged at reading position R3. An image of the back side of the document passing through reading position R3 passes through multiple reflective mirrors in the back side reading unit 67 and is formed on the image sensor of the lens and image sensor unit 69. The image sensor outputs an image signal corresponding to the document image. The lens and image sensor unit 69 is a unit in which an optical lens and a line image sensor are assembled together. The multiple reflective mirrors in the back side reading unit 67 and the optical lens in the lens and image sensor unit 69 form a reduction optical system that forms an image of the back side of the document on the image sensor of the lens and image sensor unit 69. The back-side reading unit 67 is located inside the substantially U-shaped document transport path. Therefore, the front side of the document transported by the document feeder 16 is read by the scanner unit 15, and the back side of the document is read by the back-side reading unit 67. 4, there may be an embodiment in which the document feeder 16 does not include the back-side reading unit 67. For example, this embodiment is configured to read only the front side of the document placed on the document set tray 31. Alternatively, this embodiment may include an inversion mechanism that inverts the document after passing through the reading positions R1 and R2 and reading the front side, and then transports the document to the reading positions R1 and R2 again to read the back side.

[0028] The image processing circuit 40 generates image data based on the image signal output by the scanner unit 15. Alternatively, it generates image data for printing based on print data received via the communication circuit 21. The image processing control unit 11P controls these processes in the image processing circuit 40. The generated image data is compiled into image files on a page-by-page basis, a front and back page basis, or a set of documents basis. The file control unit 11F controls the process of generating and managing image files from image data and the reading and writing of image files. The image files are printed by the image forming unit 14 or transmitted to an external device via the communication circuit 21.

[0029] 3 shows the configuration of an image processing circuit 40 for image processing related to the present invention. The blocks shown in FIG. 3 do not cover the entire image processing circuit 40, but rather show elements necessary for explaining the present invention. The input processing circuit 41 receives image signals for each page from the image sensors of the scanner unit 15 (the image sensor 61 that reads the front side and the lens and image sensor unit 69 that reads the back side) and performs image processing. It is a circuit block that generates images that are the basis for images for document area determination and images for output. The input processing circuit 41 performs A / D conversion of the image signals, shading correction, tone conversion, etc.

[0030] The document area determination circuit 45, which serves as a document area determination unit, is a circuit block that determines the document area of ​​the read image based on the determination image output from the input processing circuit 41. A document determined by the reading control unit 11S to be of an irregular size is different from a document determined to be of a standard size, and the document area determination circuit 45 determines the reading area of ​​the document. In the mode for determining the scan area (document area) of an irregular-sized document, the document area determination circuit 45 determines a rectangular document area based on the density or color difference between the document edge and the gray color of the background color plate. Because document area determination involves determining the outline of a rectangular document, the determination image can be, for example, a scanned image converted to black and white with a lower resolution to reduce processing time. In this embodiment, the document area determination circuit 45 may not only detect the outline of the document but also perform character recognition processing to detect the document's skew and top / bottom orientation, and then determine the document area based on these detection results. The determined document area is provided to the output image generation circuit 47 and used for cropping the output image.

[0031] The output image generation circuit 47 further performs image processing on the output image output from the input processing circuit 41 to generate an image file in the format to be output. The image processing performed by the output image generation circuit 47 includes cropping of the image of each page based on the document area determined by the document area determination circuit 45. Other image processing includes image quality adjustment, color correction, spatial filtering, displacement processing, etc. For example, when the scanned document image is to be sent as a PDF image file to a specified destination via the communication circuit 21, the output image generation circuit 47 generates a PDF image file from the image data of each page and outputs it.

[0032] FIG. 7 shows document size information for major standard-sized documents. The storage device 13 (see FIG. 3) stores in advance document size information, which is the standard size relating to the long side length and short side length of each of a number of main standard document sizes (A3, A4, 11" x 17", 11" x 8.5", B4, B5) shown in FIG. 7. The storage device 13 may also store in advance document size information for documents of sizes other than these standard sizes.

[0033] 6 and 7, when various standard-sized documents D are placed correctly on the document set tray 31 of the document reading device 12, depending on the size and / or orientation of the document, the document falls into one of the following patterns: a first pattern in which neither the first sensor 10ba nor the second sensor 10bb of the document size detection unit 10 is covered by the document D (OFF state); a second pattern in which only the first sensor 10ba is covered by the document D (ON state) and the second sensor 10bb is not covered by the document D (OFF state); or a third pattern in which both the first sensor 10ba and the second sensor 10bb are covered by the document D (ON state). Note that the correct state when placing a document on the document set tray 31 means a state in which the document D is stretched out in a straight plane without being bent or folded, and the document D is placed on the center line C with one end of the document D positioned at the document set position P on the document set tray 31.

[0034] For major standard-sized documents, the combinations of the ON / OFF states of the first sensor 10ba and the second sensor 10bb are as follows: For A5 size documents (long side length 210 mm x short side length 148 mm), the first pattern applies whether the document is placed vertically with its longitudinal direction aligned with the document transport direction A, or horizontally with its longitudinal direction aligned with the perpendicular direction B (i.e., regardless of the orientation of the document). For B5 size documents (long side length 257 mm x short side length 182 mm), if a standard document is placed vertically it falls under the second pattern, and if it is placed horizontally it falls under the first pattern. In the case of B4 size (long side length 364 mm x short side length 257 mm), if a standard document is placed vertically, it falls into the third pattern. However, standard documents cannot be placed horizontally in B4 size. For a standard document of 11" x 8.5" size (long side length 279.4mm x short side length 215.9mm), if it is placed vertically it falls under the second pattern, and if it is placed horizontally it falls under the first pattern. For 11" x 17" size (long side length 431.8mm x short side length 279.4mm), if a standard document is placed vertically, it falls into the third pattern. However, for 11 x 17 size, standard documents cannot be placed horizontally. For A4 size documents (long side length 297 mm x short side length 210 mm), if a standard document is placed vertically it falls under the second pattern, and if it is placed horizontally it falls under the first pattern. In the case of A3 size (long side length 420 mm × short side length 297 mm), placing a standard document in portrait orientation corresponds to pattern 3. Note that A3 size standard documents cannot be placed in landscape orientation on the document set tray 31.

[0035] Fig. 8 is an explanatory diagram when the spacing between the document guides is the same as the width of the document. Fig. 9 is a first explanatory diagram when the spacing between the document guides is wider than the width of the document, and Fig. 10 is a second explanatory diagram when the spacing between the document guides is wider than the width of the document. Fig. 11 is a first explanatory diagram when the spacing between the document guides is narrower than the width of the document, and Fig. 12 is a second explanatory diagram when the spacing between the document guides is narrower than the width of the document. In addition to placing the document in the correct state on the document set tray 31 as described above, it is desirable to adjust the spacing between the pair of document guides 10a as shown in Fig. 8 so that the pair of document guides 10a abuts or is close to both ends of the document D in the orthogonal direction B (to set the guides correctly) in order to correctly read the document area of ​​the document D. In this case, when the document D is placed vertically, the pair of short sides abuts or is close to the pair of document guides 10a, and when the document D is placed horizontally, the pair of long sides abuts or is close to the pair of document guides 10a.

[0036] However, as shown in Figures 9 and 10, a gap S exists between the pair of document guides 10a and the document D. This can result in the document D (or document stack Dx) being set with the distance between the pair of document guides 10a being too wide compared to the short or long side length of the document D. Alternatively, as shown in Figures 11 and 12, the document D can be set with the distance between the pair of document guides 10a being too narrow compared to the short or long side length of the document D. If the document D set between the pair of document guides 10a in this state is transported to the scanner unit 15 by the document feeder 16, problems such as missing or tilted document areas are likely to occur. Furthermore, the states shown in Figures 11 and 12 may cause a jam. Note that Figure 11 shows a state in which both ends of the document D are in contact with or close to the document guides 10a but the document D is bent upward. Figure 12 shows a state in which both ends of the document D are in contact with the document guides 10a but the document D is bent.

[0037] Therefore, the document reading device 12 of this embodiment detects whether the guide is set in the improper state (the state shown in FIGS. 9 and 10) described above, determines whether the document is a standard-sized document or an irregular-sized document, and uses a document detection size table such as that shown in FIG. 13A so that the document area can be read correctly without any missing or tilted portions. Here, FIG. 13A is an explanatory diagram showing an example of a document detection size table for various standard-sized documents, and FIG. 13B is an explanatory diagram showing the horizontal lengths (reference values) in the orthogonal direction for various standard-sized documents. Note that in FIGS. 13A and 13B, for example, A4R indicates a standard-sized A4 document placed in portrait orientation, while A4 is placed in landscape orientation. The same applies to A3R, B5R, and A5R.

[0038] The document detection size table of Figure 13A is stored in the memory device 13, and includes as detection elements combination patterns (the first to third patterns) of the ON / OFF states of the first sensor 10ba and the second sensor 10bb when documents of various standard sizes are placed vertically or horizontally, and the guide width W (see Figure 8) when documents of various standard sizes are placed vertically or horizontally and correctly guided and set by the pair of document guides 10a. The guide width W is set to a reference value that is the short side length of various standard size documents placed vertically or the long side length of the documents placed horizontally (i.e., the horizontal length of the placed standard size document), and the allowable range is determined by adding a predetermined value (±α) to the reference value. Note that ±α is an arbitrary value and is set to ±6.0 in this embodiment.

[0039] Specifically, in this embodiment, the allowable values ​​for the guide width W for detecting various standard sizes are in the range of max 303.0 to 291.0 (mm) for A3R / A4 size, with a reference value of 297.0 (mm), in the range of 285.4 to 273.4 (mm) for 11" x 17" / 11" x 8.5" size, with a reference value of 279.4 (mm), in the range of 263.0 to 251.0 (mm) for B4R / B5 size, with a reference value of 257.0 (mm), in the range of 216.0 to 204.0 (mm) for A4R / A5 size, with a reference value of 210.0 (mm), in the range of 188.0 to 176.0 (mm) for B5R size, and in the range of 154.0 to min 142.0 (mm) for A5R size, with a reference value of 148.0 (mm). Note that max is the upper limit of the guide width W at which the pair of document guides 10a are furthest from each other, and min is the lower limit of the guide width W at which the pair of document guides 10a are closest to each other.

[0040] For example, as shown in FIG. 6, an A4-sized standard-sized document D is placed vertically on the document set tray 31, and as shown in FIG. 8, a pair of document guides 10a are brought into contact with or close to both ends of the document D in the orthogonal direction B, whereby the document size detection unit 10 detects the vertical length (the length of the long side in the document transport direction A) and horizontal length (the length of the short side in the orthogonal direction B) of the document D. At this time, the first sensor 10ba and the second sensor 10bb of the document size detection unit 10 detect the vertical length of the document D in three steps of first to third patterns. In this case, the second pattern applies, in which the first sensor 10ba is ON and the second sensor 10bb is OFF (see the A4R display portion in FIG. 13A). The pair of document guides 10a of the document size detection unit 10 also detects the guide width W.

[0041] Therefore, if the dimensions of the document D actually set on the document set tray 31 in the document transport direction A are detected to be the second pattern, and the dimensions of the document D in the orthogonal direction B are detected to be within the allowable range of 235.9 to 196.0 (mm), the size of the document D is determined to be A4R, as shown in the document detection size table of Figure 13A. Here, as shown in Fig. 13B, the length of the short side of an A4R-sized document is equal to the length of the long side of an A5-sized document, so it is not possible to determine whether the document is A4R or A5 size simply by detecting guide width W (detecting the width of document D). However, when the length of document D is detected and only first sensor 10ba is turned ON, it can be provisionally determined that the document is A4R size, so the document size table in Fig. 13A indicates that the document size under this condition is A4R. Alternatively, when the length of document D is detected and both first sensor 10ba and second sensor 10bb are OFF, it can be provisionally determined that the document is A5 size, so the document size table in Fig. 13A indicates that the document size under this condition is A5. Alternatively, if vertical length detection is added and both the first sensor 10ba and the second sensor 10bb are ON, it can be provisionally determined that the A4R size is more likely to be the larger of A4R and A5, and therefore the document size under these conditions is determined to be A4R in the document detection size table of Figure 13A. In the document detection size table of FIG. 13A, the relationship between A4 size and A3R size, the relationship between 11"×8.5" size and 11"×17" size, and the relationship between B5 size and B4R size can also be determined in a similar manner.

[0042] Furthermore, for standard B5R size documents, regardless of whether the vertical length detection is pattern 1 to 3, it can be provisionally determined that the document is likely to be B5R size by detecting the guide width W (horizontal length detection), so the document size under these conditions is determined to be B5R in the document detection size table of Figure 13A. Furthermore, for standard A5R size documents, regardless of whether the vertical length detection is pattern 1 to 3, it can be provisionally determined that the document is likely to be A5R size by detecting the guide width W (horizontal length detection), so the document size under these conditions is considered to be A5R in the document detection size table of Figure 13A.

[0043] <Reading operation of the document reading device> Next, the operation of reading an original by the original reading device 12 configured as above will be described. FIG. 14 is a flowchart showing the document reading process executed by the control unit in the first embodiment. The procedure of the process executed by the control unit 11 will be described below with reference to the flowchart. 3, 6, and 14, the control unit 11 as the UI control unit 11U detects that the document D has been placed on the document set tray 31 of the document reading device 12 by a detection signal from the document sensor 10bc (step S11). Note that here, a case will be described in which the document image to be read is provided only on the front surface (top surface) of the document D. When the placement of the document is detected, the control unit 11 as the reading control unit 11S acquires document size information from the document size detection unit 10 (the pair of document guides 10a, the first sensor 10ba, the second sensor 10bb, etc.) (step S13). This document size information includes document size information relating to the combination of the vertical length of the placed document D along the document transport direction A and the horizontal length along the orthogonal direction B.

[0044] After step S13, the control unit 11 as the reading control unit 11S preliminarily (provisionally) determines in the first stage which of the multiple standard sizes the size of the placed document D corresponds to based on the acquired document size information (step S15). In this step S15, for example, as shown in Figures 6 and 8, if the user places the document D on the document set tray 31 and the distance (guide width W) between the pair of document guides 10a is adjusted to be close to the horizontal length (reference value) of a standard document of A4R or A5 size, the control unit 11 as the reading control unit 11S preliminarily determines that the document size is likely to be A4R or A5, and further, depending on the combination of the ON / OFF states of the first sensor 10ba and the second sensor 10bb, the control unit 11 as the reading control unit 11S preliminarily determines the size of the document D as follows.

[0045] 6 and 13A, when the combination of the ON / OFF states of the first sensor 10ba and the second sensor 10bb is the second pattern or the third pattern, the control unit 11 as the reading control unit 11S preliminarily determines that the size of the document D is A4R. Note that if one edge d1 of the document D abuts or is close to the document set position P, the document D will not be in the third pattern. However, for example, if one edge d1 of one page of the document stack Dx (see FIG. 10) is significantly displaced from the document set position P, the opposite edge d2 of the document D may cover the second sensor 10bb, resulting in the document D being in the third pattern. In such a case, the document D will also be determined to be A4R. On the other hand, when the combination of the ON / OFF states of the first sensor 10ba and the second sensor 10bb is the first pattern, it is highly likely that the size of the document D set on the document set tray 31 is A5, and therefore the control unit 11 as the reading control unit 11S preliminarily determines that the size of the document D is A5.

[0046] After step S15, the control unit 11 functioning as the UI control unit 11U detects that an instruction to start a job for reading a document (such as a scanner job or a copy job) has been issued (step S17). When an instruction to start a job to read a document is issued (Yes in step S17), the control unit 11 as the job control unit 11J recognizes this and starts executing the job. Here, in the second stage after the first stage, the control unit 11 as the reading control unit 11S determines whether the size of the document D is a standard size or an irregular size based on the standard size preliminarily determined in the first stage and the document size information (step S19). Although not shown, when an instruction to start a job to read a document is issued (Yes in step S17), the job management unit 11J registers the job whose execution has been instructed as a job to be executed. Then, the job management unit 11J requests the job execution unit 11X to execute the job. In response, the job execution unit 11X performs processing according to the job settings.

[0047] In step S19, for example, if the difference between the reference value 210.0 mm in Fig. 13B, which is the width of the A4R size document D determined in the first stage, and the width of the document D (for example, X mm), which is the width related to the document size information, does not exceed the allowable range of 216.0 to 204.0 mm (X mm is within the range of 216.0 to 204.0 mm), the control unit 11 as the reading control unit 11S determines that the document is of standard size. On the other hand, if X mm is, for example, 216.1 mm or more or 103.9 mm or less, the control unit 11 determines that the document is of irregular size.

[0048] The document D set on the document set tray 31 is determined to be an irregular size when the size is not A4R, when the document size is A4R but there is a gap S exceeding the allowable range between the document D or document stack Dx and the pair of document guides 10a as shown in Fig. 9 or 10, or when the document size is A4R but the document D is warped or folded to an extent exceeding the allowable range as shown in Fig. 11 or 12. In other words, the control unit 11 as the reading control unit 11S determines that an irregular document has been set not only when an irregular document is actually set, but also when a standard document has been improperly set as shown in Figs. 9 to 12.

[0049] In step S19, if the reading control unit 11S determines that the document is of standard size, it determines the reading area of ​​the document in normal mode (step S21), and if the document is of irregular size, it determines the reading area of ​​the document in a predetermined mode different from the normal mode (step S23). In the normal mode in step S21, the document area determination circuit 45 determines the reading area of ​​the document D, which has been determined to be A4R size, as A4R size, for example. In the predetermined mode of step S23, the document area determination circuit 45 determines the reading area of ​​document D, which has been determined to be an irregular size other than A4R, as the smallest area that completely surrounds the A4R size. In this embodiment, the predetermined mode is a crop scan mode that reads irregular-sized documents.

[0050] After step S21 or step S23, the control unit 11 drives the document feeder 16 to transport the document D set on the document set tray 31 in the document transport direction A toward the scanner unit 15 (step S25). Then, as the document D passes through reading positions R1 and R2 provided along the document transport path, the scanner unit 15 reads the document area of ​​the document D (step S27). At this time, the scanner unit 15 reads at reading position R1 in the normal mode, and at reading position R2 in the crop scan mode. At reading position R1, the front side background color plate 51 is in white, and at reading position R2, the front side background color plate 51 is in gray.

[0051] In step S27, the control unit 11 as the reading control unit 11S controls the scanner unit (document reading unit) 15 to determine the document boundary from an image obtained by reading the entire document area and cut out the document area in a predetermined mode for reading an irregular size. Also, the control unit 11 as the reading control unit 11S controls the scanner unit (document reading unit) 15 to read the area determined in step S23 (the smallest area capable of reading the entire document area) in a predetermined mode for reading an irregular size.

[0052] Furthermore, in step S27, the control unit 11, functioning as the image processing control unit 11P, controls the input processing circuit 41, document area determination circuit 45, and output image generation circuit 47 of the image processing circuit 40 to perform image processing on the image of the document D read by the scanner unit 15. The document area determination circuit 45 determines the document area based on the image read at reading position R2, and causes the output image generation circuit 47 to crop the document image. The cropped document images are then output together as an image file. In this way, the image of one document D is read and the image data created is stored in the storage device 13, and then the control unit 11, acting as the job execution unit 11X, determines whether reading of the fed document D has been completed (step S29).

[0053] When it is determined that the reading of the image of one document D is complete (Yes in step S29), the control unit 11 as the job execution unit 11X determines whether or not there are any documents remaining to be read (step S31), and if it is determined that there are, the process returns to step S25 to repeat the process related to reading the next document. Then, when the reading of all documents is complete (No in step S31), the execution of the job is completed. Thus, according to the first embodiment, when an irregular-sized original is set, or when a standard-sized original is set improperly, the original image can be automatically read in crop scan mode to prevent missing or tilted images, thereby improving user convenience.

[0054] (Second embodiment) Fig. 15A is an explanatory diagram showing an example of an original detection size table for AB-system standard documents, and Fig. 15B is an explanatory diagram showing an example of an original detection size table for INCH-system standard documents. Also, Fig. 16A is an explanatory diagram showing the horizontal length (reference value) in the orthogonal direction for AB-system standard documents, and Fig. 16B is an explanatory diagram showing the horizontal length (reference value) in the orthogonal direction for INCH-system standard documents. Note that Fig. 15A is substantially the same as Fig. 13A, and Fig. 15B is substantially the same as Fig. 13B. In the second embodiment, a case will be described in which a document detection size table for AB-based standard documents and a document detection size table for INCH-based standard documents are used, as shown in Figures 15A and 15B. Note that the document detection size table for AB-based standard documents shown in Figure 15A includes some INCH-based standard document sizes (especially those with high frequency of use), and the document detection size table for NICH-based standard documents shown in Figure 15B includes some AB-based standard document sizes (especially those with high frequency of use).

[0055] The following mainly describes the differences between the second embodiment and the first embodiment. As shown in Figures 15B and 16B, the INCH-based standard size documents include 11" x 17" size, 11" x 8.5" size, 8.5" x 13" size, 8.5" x 11" size, 8.5" x 5.5" size and 5.5" x 8.5" size. As shown in Figures 15B and 16B, the range of allowable guide width values ​​in the document detection size table for INCH-based standard documents is the same as in the first embodiment for 11" x 17" and 11" x 8.5" sizes, and is in the range of 221.9 to 209.9 (mm) with a reference value of 215.9 (mm) for 8.5" x 13" size, 8.5" x 11" size, and 8.5" x 5.5" size, and is in the range of 245.7 to min133.7 (mm) with a reference value of 139.7 (mm) for 5.5" x 8.5" size.

[0056] Although not shown in the block diagram of FIG. 3, the multifunction peripheral 100 of the second embodiment includes a destination specification setting section in the UI unit 19 for setting specifications for a particular destination. The storage device 13 also stores a plurality of standard sizes according to destination specifications in advance. That is, the document detection size table for AB-based standard documents shown in Fig. 15A and the document detection size table for INCH-based standard documents shown in Fig. 15B are stored in advance in the storage device 13. When the multifunction device 100 is used in a country or region (destination) where AB-based standard documents are mainly used, the destination specification setting unit is set in advance to the AB-based standard document specifications, and when the multifunction device 100 is used in a country or region (destination) where INCH-based standard documents are mainly used, the destination specification setting unit is set in advance to the INCH-based standard document specifications.

[0057] Next, the document reading operation by the document reading device of the second embodiment will be described with reference to FIGS. 3, 6, 15A and 15B, 16A and 16B, and 17. FIG. FIG. 17 is a flowchart showing the document reading process executed by the control unit in the second embodiment. 17, steps S11 to S17 are performed in the same manner as in the first embodiment, and when an instruction to start a job to read a document is given (Yes in step S17), the control unit 11 as the reading control unit 11S makes the following determination: In other words, when the document size information detected in step S13 relates to a specific combination of vertical length and horizontal length, and the horizontal length related to the document size information is within the range of the allowable value for the length predetermined in the specifications for the different destination, the control unit 11 determines that the document is an irregular size in the second stage even if it was determined in the first stage that the document corresponds to the standard size for the specific destination.

[0058] For example, the allowable guide width range for A4R / A5 size AB standard documents is 216.0 to 204.0 mm, while the allowable guide width range for 8.5" x 13", 8.5" x 11", and 8.5" x 5.5" sizes of INCH standard documents is 221.9 to 209.9 mm, with these sizes partially overlapping. Also, the allowable guide width range for A5R size AB standard documents is 154.0 to 142.0 mm, while the allowable guide width range for 5.5" x 8.5" sizes of INCH standard documents is 145.7 to 133.7 mm, with these sizes partially overlapping. Therefore, if the multifunction device 100 is preset for AB standard document specifications, it is possible that a missing portion will occur when a document of an INCH standard size is loaded, preventing proper document scanning.

[0059] Therefore, in the second embodiment, when the document size information acquired in step S13 is preset to the AB-system standard document specifications and relates to a specific standard size (i.e., A4R / A5 size or A5R size), if the detected actual guide width W of the specific AB-system standard size is within the allowable range for the length preset in the INCH-system standard document specifications (i.e., the horizontal length of 8.5" x 13" / 8.5" x 11" / 8.5" x 5.5" size or 5.5" x 8.5" size), the control unit 11 as the reading control unit 11S determines that the document corresponds to the standard size of the AB-system standard document specifications in the first stage, but determines that the document is an irregular size in the second stage. Alternatively, if the document is preset to INCH-based standard document specifications and the document size information acquired in step S13 relates to a specific standard size (i.e., 8.5" x 13" / 8.5" x 11" / 8.5" x 5.5" size or 5.5" x 8.5" size), when the detected actual guide width W of the specific INCH-based standard size is within the allowable range for the length preset in the AB-based standard document specifications (i.e., the horizontal length of A4R / A5 size or A5R size), the control unit 11 as the reading control unit 11S determines that the document corresponds to a standard size of the INCH-based standard document specifications in the first stage, but determines that the document is an irregular size in the second stage.

[0060] In the second embodiment, if the document size information relates to a standard size other than a specific standard size, step S19 is executed as in the first embodiment, and after determining that the size is non-standard (Yes in step S19), step S23 and subsequent steps are executed as in the first embodiment. If a document with destination specifications different from those set is set, or if there is an error in the destination specifications setup, scanning the document image as is may result in missing parts and the output result may not be what the user desires. However, according to the second embodiment, the document image can be automatically read in crop scan mode, so the image is output without any missing parts.

[0061] (Third embodiment) FIG. 18 is a flowchart showing the document reading process executed by the control unit in the third embodiment. The third embodiment is generally similar to the first and second embodiments, except that the irregular size determination process in step S19 is different from the first and second embodiments. The following mainly describes the differences between the third embodiment and the first and second embodiments.

[0062] 17, steps S11 to S17 are performed in the same manner as in the first and second embodiments, and when an instruction is given to start a job to read a document (Yes in step S17), the control unit 11 as the reading control unit 11S makes the following judgment: In other words, when the document size information detected in step S13 relates to a specific combination of length and width, and the width related to the document size information is within a predetermined small error range within the tolerance range with respect to the length predetermined in the specifications for the other destination, the control unit 11 judges the document to be an irregular size in the second stage even if it was judged to correspond to the standard size for the specific destination in the first stage.

[0063] In other words, if the document is preset to the AB-system standard document specifications and the document size information acquired in step S13 relates to a specific standard size (i.e., A4R / A5 size or A5R size), when the detected actual guide width W of the specific AB-system standard size is within a predetermined minute error range within the tolerance range for the length preset in the INCH-system standard document specifications (i.e., the horizontal length of 8.5" x 13" / 8.5" x 11" / 8.5" x 5.5" size or 5.5" x 8.5" size), then even if it was determined to correspond to the standard size of the AB-system standard document specifications in the first stage, it will be determined to be an irregular size in the second stage. For example, even if the actual guide width W is within the range of 216.0 to 204.0 mm, which is the guide width tolerance for A4R / A5 sizes, if the actual guide width W is within the overlap range of 216.0 to 209.9 mm within the guide width tolerance range of 221.9 to 209.9 mm for 8.5" x 13" / 8.5" x 11" / 8.5" x 5.5" sizes, it is highly likely that a standard inch document has been set, and the document is determined to be of an irregular size. In this example, instead of the overlap range of 216.0 to 209.9 mm, the guide width standard value for 8.5" x 13" / 8.5" x 11" / 8.5" x 5.5" sizes may be set to a range of 215.9 mm ±α mm (where α is approximately 3.0 to 6.0).

[0064] Alternatively, if the document is preset to INCH-based standard document specifications and the document size information acquired in step S13 relates to a specific standard size (i.e., 8.5" x 13", 8.5" x 11", 8.5" x 5.5", or 5.5" x 8.5"), when the detected actual guide width W of the specific INCH-based standard size is within a predetermined minute error range within the tolerance range for the length preset in the AB-based standard document specifications (i.e., the horizontal length of A4R / A5 size or A5R size), the document is determined to be an irregular size in the second stage even if it was determined to correspond to the standard size of the INCH-based standard document specifications in the first stage. For example, even if the actual guide width W is within the range of 221.9 to 209.9 mm, which is the guide width tolerance for 8.5" x 13", 8.5" x 11", and 8.5" x 5.5" sizes, if the actual guide width W is within the overlap range of 216.0 to 209.9 mm, which is within the guide width tolerance range of 216.0 to 204.0 mm for A4R / A5 sizes, it is determined that an AB-based standard size document has been set and the document is determined to be of an irregular size. In this example, instead of the overlap range of 216.0 to 209.9 mm, the guide width standard value for A4R / A5 sizes may be set to a range of 210.0 mm ±α mm (where α is approximately 3.0 to 6.0).

[0065] When determining whether an INCH-based standard document can be set in an AB-based standard document specification, or whether an AB-based standard document can be set in an INCH-based standard document specification, the A5R size and 5.5" x 8.5" sizes, which have similar sizes, can also be determined to be irregular sizes in the same manner as described above. In the third embodiment, if the document size information relates to a standard size other than a specific standard size, step S19 is executed as in the first embodiment, and after determining that the size is non-standard (Yes in step S19), step S23 and subsequent steps are executed as in the first embodiment. If a document with destination specifications different from the set destination specifications is set, or if there is an error in the destination specification installation, scanning the document image as is may result in missing parts and the output result may not be what the user desires, but according to the third embodiment, the document image can be automatically scanned in crop scan mode, so the image is output without any missing parts. Also, with the third embodiment, it is possible to further improve the accuracy of judgment between standard documents of similar sizes with different destination specifications (AB standard document specifications and INCH standard document specifications).

[0066] (Fourth embodiment) FIG. 19 is a flowchart showing the document reading process executed by the control unit in the fourth embodiment. The fourth embodiment is generally similar to the first to third embodiments, except that the irregular size determination process in step S19 is different from the first to third embodiments. The following mainly describes the differences between the fourth embodiment and the first to third embodiments.

[0067] In the fourth embodiment, as shown in FIG. 19, steps S11 to S17 are performed in the same manner as in the first to third embodiments, and when an instruction is given to start a job to read a document (Yes in step S17), the control unit 11 as the reading control unit 11S determines that the document is of an irregular size if there is a difference between the vertical length of the standard size determined in the first stage in step S19 and the vertical length related to the document size information acquired in step S13 that exceeds a predetermined tolerance range.

[0068] That is, referring to Figures 6, 7 and 15A, when an original D is set on the original set tray 31, based on the original size information that, for horizontal length detection, the distance (actual guide width) between the pair of original guides 10a is within the range of 303.0 to 291.0 (mm), and for vertical length detection, the first sensor 10ba is ON and the second sensor 10bb is OFF, the control unit 11 as the reading control unit 11S determines in the first stage in step S19 that the set original D is A3R size. However, if the document D is A3R size, both the first and second sensors 10ba and 10bb should be ON (third pattern), and there is a difference exceeding a predetermined tolerance range (in this case, at least 305 mm) between the vertical length of the A3R size determined in the first stage (420 mm) and the vertical length related to the document size information acquired in step S13 (the distance from the document set position P that does not reach the second sensor 10bb and is less than 305 mm), so the control unit 11 as the reading control unit 11S determines that the document D is irregular in the second stage. Also, since the ON / OFF states of the first and second sensors 10ba and 10bb in the second pattern are likely to indicate A4 size (a state in which the long side is placed along the orthogonal direction B), the control unit 11 as the reading control unit 11S determines that the document D is irregular in the second stage.

[0069] If an A4 size document is detected as A3R size and the document image is read, there is a risk of missing or blank areas occurring, but according to the fourth embodiment, the document image can be automatically read in crop scan mode, so the image will not be missing or output with blank areas. The above-mentioned vertical length detection also applies to 11" x 17" / 11" x 8.5" sizes, B4R / B5 sizes, etc. in addition to A3R / A4 sizes.

[0070] (Fifth embodiment) Fig. 20 is a flowchart showing the document reading process executed by the control unit in the fifth embodiment. Also, Figs. 21A to 21C show first to third examples of the user setting screen displayed on the display device. In the first to fourth embodiments, an example is given of a case where, if it is determined in step S19 that the document D set on the document set tray 31 is of an irregular size or that the document D is not set properly, the mode is automatically switched to crop scan mode to perform image reading processing (see Figures 6, 14, and 17 to 19). On the other hand, the fifth embodiment differs from the first to fourth embodiments as follows, but is generally similar to the first to fourth embodiments in other respects. In the fifth embodiment, as shown in Fig. 20, if it is determined in step S19 that the document D set on the document set tray 31 is of an irregular size, one of the user setting screens shown in Figs. 21A to 21C is displayed on the display device 19D depending on the circumstances and reasons for determining that the document D is of an irregular size (step S21). This user setting screen is a mode switching selection screen.

[0071] On the screen shown in FIG. 21A, when the guide width does not match the document size as described in the first embodiment (FIGS. 9 to 12), for example, "There is a mismatch in the guide width compared to the document size" is displayed. On the screen shown in Figure 21B, as described in the second and third embodiments, when an INCH-based standard document is set when the AB-based standard document specification is set, or when an AB-based standard document is set when the INCH-based standard document specification is set, a message such as "The document detection device setting may be incorrect" is displayed. On the screen shown in FIG. 21C, as described in the fourth embodiment, when there is a difference between the document size information and the detected length in relation to vertical length detection, a message such as "There is a difference in the document length compared to the document size" is displayed.

[0072] In all of Figures 21A to 21C, "Yes" and "No" buttons are displayed on the screen, and when the user presses the "No" button (No in step S23), the document reading area is determined in normal mode (step S25), and when the user presses the "Yes" button (Yes in step S23), the document reading area is determined in crop scan mode (step S27). If the user presses the "x" mark on the screen to cancel (cancel in step S23), the document is not read and the process ends. Then, after step S25 or S27, the same processes (steps S29 to S35) as those after step S25 in the first to fourth embodiments are executed, and the process ends. In this way, in the fifth embodiment, if it is determined that the document D set on the document set tray 31 is of an irregular size or that the document D has not been set properly, a user setting screen is displayed on the display device 19D to allow the user to select whether to process in crop scan mode or normal mode.

[0073] (Sixth embodiment) Fig. 22 is a flowchart showing the document reading process executed by the control unit in the sixth embodiment. Also, Figs. 23A to 23E show first to fifth examples of the user setting screen displayed on the display device in the sixth embodiment. The sixth embodiment differs from the first to fifth embodiments as follows, but is generally similar to the first to fifth embodiments in other respects. In the sixth embodiment, when the control unit 11 as the reading control unit 11S determines that the document is an irregular size, the scanner unit 15 reads the document in a mode for reading irregular sizes, and then the display device 19D displays preview images of two cases: one in which an area corresponding to the regular size determined in the first stage is cut out, and the other in which the boundary of the document is cut out, and the user is allowed to select either one.

[0074] That is, in the sixth embodiment, as shown in FIG. 22, after performing the processing up to step S31 in the same manner as up to step S31 in the first to fourth embodiments or up to step S35 in the fifth embodiment, it is determined whether or not the operation was in crop scan mode (step S33), and if the operation was in normal mode (No in step S33), the processing is terminated. On the other hand, if the operation is in crop scan mode (Yes in step S33), image cropping processing is performed (step S35), and one of the image selection screens shown in Figures 23A to 23E is displayed on the display device 19D depending on the crop scan status (step S37).

[0075] The screen shown in Figure 23A shows the scanned image before and after cropping in a situation where a guide misalignment occurs between a pair of document guides 10a and a document D set on the document set tray 31, causing the document D to be misaligned in the document transport direction A relative to the center line C (see Figure 6). The screen shown in Figure 23B shows a guide misalignment of the pair of document guides 10a with respect to the document D set on the document set tray 31, causing the document D to be displaced diagonally from the center line C, and shows the read image before cropping and the read image after cropping in that situation (see Figure 6). The screen shown in Fig. 23C shows the scanned image before and after cropping in a situation where missing or blank areas occur due to an incorrect destination specification setting for the scanned standard size document. For example, if an A4R size standard document is set, and because the scanner is set to INCH standard size document specifications, it is detected as an 8.5" x 11" standard size document, and because it is possible that it is A4R size, the scanned image before and after cropping are displayed. The screen shown in Figure 23D shows the scanned image before and after cropping in a situation where missing or blank spaces occur when scanning a special document that is close to the size of a standard document. For example, if a special document with a width (guide width W) of ±10 mm for A4R is set, and because the scanner is set to AB-type standard document specifications, it is detected as an A4R-sized standard document, and because it may be a special document, the scanned image before and after cropping is displayed. The screen shown in FIG. 23E shows the scanned image before and after cropping in a situation where missing parts or blank spaces occur when scanning a special document of A3 length but A4R width, for example.

[0076] In FIGS. 23A to 23E, by selecting the image before or after cropping, the selected image is output (step S39), and the process ends. As described above, in the sixth embodiment, when the image scanner operates in the crop scan mode, the user is prompted to select either the scanned image before cropping or the scanned image after cropping, and the selected image is output.

[0077] Seventh embodiment FIG. 24 is a flowchart showing the document reading process executed by the control unit in the seventh embodiment. The seventh embodiment differs from the first to sixth embodiments in the following respects, but is generally similar to the first to sixth embodiments in other respects. In the seventh embodiment, the reading control unit 11S (see FIG. 3) controls the scanner unit (document reading unit) 15 in a crop scan mode for reading non-standard sizes to read the smallest possible area of ​​the entire document based on the standard size determined in the first stage and document size information. Also, in the crop scan mode, the control unit 11 as the reading control unit 11S determines the required memory capacity and the image reading size based on the standard size information stored in the storage device 13 and the document size information detected by the document size detection unit 10.

[0078] That is, in the seventh embodiment, as shown in Figures 3 and 24, after operating in crop scan mode (step S23), the document area determination circuit 45 determines the image reading width and length based on the standard size information and the document size information (step S24), and also determines the capacity of the image storage memory from the image reading width and length (step S25), and then starts document feeding (step S26). For example, the main scanning width (orthogonal direction B) is set to the larger of the width of the detected document size + α and the actual guide width + α, and the sub-scanning length (document transport direction A) is set to the detected document size + α to determine the document reading size. Alternatively, for example, in the case of a special document with a horizontal length (orthogonal direction B) of 240 mm and a vertical length (document transport direction A) of 250 mm, the main scanning width (orthogonal direction B) is set to the larger of the width of the detected document size + α and the actual guide width + α, and the sub-scanning length (document transport direction A) is set to the distance L2 (305 mm) from the document set position P to the second sensor 10bb, thereby determining the document reading size (see Figure 6). When the maximum size is read, a large amount of memory is allocated and the cropping process takes time, but according to the seventh embodiment, no extra reading time or memory capacity is required, and the cropping process time is shortened.

[0079] (Eighth embodiment) The document reading device of the eighth embodiment has the configuration shown in FIG. 3, but differs from the first to seventh embodiments in the following respects, and is generally similar to the first to seventh embodiments in other respects. In the eighth embodiment, the storage device (storage unit) 13 stores the vertical and horizontal lengths of each standard size in one or more increments (for example, a length range of approximately 0.1 mm to 310.0 mm in 0.1 mm increments). For example, the storage device 13 may store in advance, as lengths belonging to one standard size, a length range of multiple increments in at least one of the vertical and horizontal multi-level detection directions in which the document size detection unit 10 detects the length in increments that are greater than the number of standard sizes.

[0080] Furthermore, the document size detection unit 10 detects the length of at least one of the vertical and horizontal lengths of the document at intervals greater than the number of standard sizes. For example, if there are nine standard sizes (see FIG. 7), sensors are provided at 11 intervals on the center line C from the document setting position P toward the document conveyance direction A so as to detect one end of each standard size in the vertical direction (the upstream end in the document conveyance direction A in FIG. 6). These sensors are not evenly spaced, but are provided at positions slightly shorter than the vertical length of each standard size document. Furthermore, the 11th sensor, which is farthest from the document setting position P, detects non-standard sizes longer than the A3R size. On the other hand, the detection of the horizontal length by the pair of document guides 10a of the document size detection unit 10 is the same as in the first to seventh embodiments. Note that the vertical length of the document may also be detected using a single document guide that is slidable in the document transport direction A.

[0081] In addition, in the eighth embodiment, the control unit 11 as the reading control unit 11S determines whether the size of the placed document corresponds to one of the standard sizes or an irregular size that does not correspond to any of the standard sizes, based on the document size detection information relating to the combination of vertical length and horizontal length detected by the document size detection unit 10. Furthermore, the document area determination circuit 45 determines the document reading area in a mode different from that for a document determined to be of standard size by the control unit 11 as the reading control unit 11S, when the document is determined to be of irregular size. In addition, the control unit 11 as the reading control unit 11S may make a preliminary determination as to which of a plurality of standard sizes the size of the placed document corresponds to, and may determine that the document is an irregular size document if there is a difference between the length of the preliminarily determined standard size and the length of the detected document in the multi-stage detection direction that exceeds a predetermined tolerance range. Furthermore, the eighth embodiment may be combined with the characteristic elements of the second to seventh embodiments.

[0082] (summary) As mentioned above, (i) The document reading device according to the first invention corresponding to the first embodiment, a document reading unit that reads a document; a document transport unit configured to transport a document placed on the document in a document transport direction toward the document reading unit; a storage unit that stores in advance standard sizes relating to the long side length and short side length of each of a plurality of standard size documents; a document size detection unit that detects a vertical length of the document placed along the document transport direction and a horizontal length of the document in a direction perpendicular to the document transport direction; an original size determination unit that preliminarily determines in a first stage which of a plurality of standard sizes the size of the placed original corresponds to based on original size information relating to the combination of the vertical length and horizontal length detected by the original size detection unit; a document area determination unit; the document size determination unit determines, in a second stage after the first stage, whether the document size is a standard size or an irregular size based on the standard size determined in the first stage and the document size information; The document area determining unit determines the reading area of ​​a document that the document size determining unit determines to be an irregular size in a mode different from that of a document that the document size determining unit determines to be an irregular size.

[0083] In the document reading device according to the first aspect of the present invention, the document size is preliminarily (provisionally) determined, and then the document image is read at a size corresponding to the document size information. In this case, in the case of an irregular size, a crop scan mode, which is a mode different from the standard size, is used to read a size slightly larger than the actual document size rather than the maximum size, thereby shortening the reading time, reducing memory capacity, and shortening the crop processing time. Furthermore, output images with tilts, misalignments, missing parts, etc., which were previously generated, can be correctly cropped, and tilted images can be output after being corrected. Furthermore, manual document size input by the user is not required.

[0084] In the first aspect of the present invention, the document reading unit scans a document to read an image. A typical example of such a device is a linear image sensor, such as a charge-coupled device (CCD) or a contact image sensor (CIS). Since document sizes up to A3 or A4 are typically scanned, using an area image sensor would require a large reduction optical system and sensor. Therefore, a linear image sensor is used, and a scanning mechanism that moves the document relative to the image sensor in the sub-scanning direction achieves a compact overall device. In feeder mode, the image sensor's reading position in the sub-scanning direction is typically fixed, and the document is transported and moved to read the image. In platen mode, the document is typically fixed on a platen and the reading position is moved. In the case of a CIS, the image sensor is mounted on a carriage and the reading position is moved in the sub-scanning direction. In the case of a CCD image sensor, a mirror constituting the reduction optical system is mounted on the carriage and the reading position is moved in the sub-scanning direction.

[0085] Furthermore, the document area is the area that corresponds to the document within the area that the image sensor can read. The image sensor's readable area is usually slightly larger than the largest document size that can be read, because it takes into account the tolerances of the document transport mechanism and optical system adjustments. The document reading device cuts out the document area corresponding to the detected or set document size from the scanned image.

[0086] Cropping the document area means making the output image, i.e., the image to be printed or transmitted, correspond to the document area (cropping process). If the size of the output image is larger than the document area, the area outside the document area is filled with specified pixels (usually white pixels) before output.

[0087] Furthermore, a preferred embodiment of the first invention will be explained. (ii) The document size determination unit may determine that the document is of an irregular size if there is a difference between the vertical length of the standard size determined in the first stage and the vertical length related to the document size information, or between the horizontal length of the standard size determined in the first stage and the horizontal length related to the document size information, that exceeds a predetermined tolerance range. According to this configuration, for example, when the document guide is used to detect the width of a document set thereon, it is possible to perform generally accurate width detection while allowing for some positional deviation of the document guide relative to the document.

[0088] (iii) further comprising a destination specification setting unit for setting a specific destination specification; The storage unit can store the plurality of standard sizes in advance according to destination specifications, When the document size information relates to a specific combination of vertical length and horizontal length, if the vertical length related to the document size information is within the range of the tolerance for a length predetermined for another destination that is different from the set specific destination specifications, or if the horizontal length related to the document size information is within the range of the tolerance for a length predetermined for the other destination specifications, the document size determination unit may determine that the document is an irregular size in the second stage even if it was determined in the first stage that the document corresponds to a standard size for the specific destination. If the destination specification setting is incorrect, for example, if the scanner is set to INCH standard document specifications even though AB standard document sizes are the primary format used (or vice versa), there is a risk of missing or blank spaces in the scanned document image. With this configuration, even if the destination specification setting is incorrect, the scanner can determine that the document is an irregular size and operate in crop scan mode.

[0089] (iv) further comprising a destination specification setting unit for setting a specific destination specification; The storage unit can store the plurality of standard sizes in advance according to destination specifications, When the document size information relates to a specific combination of vertical length and horizontal length, if the vertical length related to the document size information is within the tolerance range for a length predetermined for another destination that is different from the set specific destination specifications, or if the horizontal length related to the document size information is within a predetermined small error range within the tolerance range for the length predetermined for the other destination specifications, the document size determination unit may determine that the document is an irregular size in the second stage even if it was determined to correspond to a standard size for the specific destination in the first stage. According to this configuration, it is possible to specialize in distinguishing between standard documents that are similar in size but have different destination specifications (AB-based standard document specifications and INCH-based standard document specifications).

[0090] (v) further comprising a reading control unit that controls the document reading unit; The reading control unit may control the document reading unit so that in a mode for reading standard sizes, a predetermined area corresponding to each standard size is used as the reading area, and in a mode for reading irregular sizes, the document reading unit determines the document boundary from an image obtained by reading the entire area of ​​the document and cuts out the document area. According to this configuration, an original image without missing parts or blank spaces can be obtained.

[0091] (vi) In a mode for reading irregular sizes, the reading control unit may control the document reading unit to read the smallest area possible to read the entire area of ​​the document based on the standard size determined in the first stage and the document size information. This configuration does not require extra reading time or memory capacity, and reduces the crop processing time.

[0092] (vii) further comprising a display unit capable of displaying a screen in a mode for reading a standard size and a mode for reading an irregular size; The display unit may display a user setting screen for setting either a mode for reading standard sizes or a mode for reading non-standard sizes. According to this configuration, when it is determined that the document set on the document set tray is of an irregular size or has not been set properly, a user setting screen is displayed on the display unit, allowing the user to select whether to process in crop scan mode or normal mode.

[0093] (viii) further comprising a display unit capable of displaying a screen in a mode for reading a standard size and a mode for reading an irregular size; If the document size determination unit determines that the document is an irregular size, the document reading unit may read the document in a mode for reading irregular sizes, and then the display unit may display preview images of two cases: one in which an area corresponding to the regular size determined in the first stage is cut out, and one in which the boundary of the document is cut out, and accept a selection of either. According to this configuration, when operating in the crop scan mode, the user can select either the scanned image before cropping or the scanned image after cropping, and output it.

[0094] (I) Furthermore, the document reading device according to the second invention corresponding to the eighth embodiment is a document reading unit that reads a document; a document transport unit configured to transport a document placed on the document in a document transport direction toward the document reading unit; a storage unit that stores in advance the vertical and horizontal lengths of each of a plurality of standard sizes related to documents; a document size detection unit that detects a vertical length of the document placed along the document transport direction and a horizontal length of the document in a direction perpendicular to the document transport direction; a document size determination unit that determines the size of the document; a document area determination unit; The storage unit stores the length and width of each standard size in increments of 1 or more, the document size detection unit detects the length of at least one of the vertical length and the horizontal length of the document in increments greater than the number of types of the standard sizes; the document size determination unit determines whether the size of the placed document corresponds to one of the standard sizes or an irregular size based on document size detection information relating to a combination of the vertical length and the horizontal length detected by the document size detection unit; The document area determining unit determines the reading area of ​​a document that the document size determining unit determines to be an irregular size in a mode different from that of a document that the document size determining unit determines to be an irregular size.

[0095] Furthermore, a preferred embodiment of the second invention will be explained. (II) the storage unit pre-stores a length range of a plurality of increments in at least one of the vertical and horizontal multi-step detection directions in which the document size detection unit detects the length in increments that are greater than the number of standard sizes, as a length that belongs to one standard size; The document size determination unit may perform a preliminary determination as to which of a plurality of standard sizes the size of the document placed on it corresponds to, and may determine that the document is an irregular size document if there is a difference between the length of the preliminarily determined standard size and the length of the detected document in the multi-stage detection direction that exceeds a predetermined tolerance range.

[0096] (III) further comprising a destination specification setting unit for setting a specific destination specification; The storage unit can store the plurality of standard sizes in advance according to destination specifications, When the document size detection information is a specific combination, if the length detected in the multi-stage detection direction is within the range of the tolerance for a predetermined length in another destination specification that is different from the set specific destination specification, the document size determination unit may determine that the document is an irregular size even if it has preliminarily determined that the document corresponds to a standard size for the specific destination.

[0097] (IV) further comprising a destination specification setting unit for setting a specific destination specification; When the document size detection information is a specific combination, if the length detected in the multi-stage detection direction is within a predetermined range of minute error within the tolerance range with respect to a length predetermined in another destination specification different from the set specific destination specification, the memory unit may determine that the document is an irregular size even if it has preliminarily determined that the document corresponds to a standard size for the specific destination.

[0098] (V) The document size detection unit may be configured to determine that the document is of an irregular size if the length detected in the multi-stage detection direction corresponds to one of the standard sizes, but the combination of the length and width does not correspond to any of the standard sizes.

[0099] Preferred aspects of the present invention include any combination of the above-mentioned aspects. In addition to the above-described embodiment, various modifications of the present invention are possible. These modifications should not be interpreted as not falling within the scope of the present invention. The present invention should include all modifications within the scope of the claims and their equivalents. [Explanation of symbols]

[0100] 10: Document size detection unit, 10a: Document guide, 10ba: First sensor, 10bb: Second sensor, 10bc: Document sensor, 11: Control unit, 11C: Communication control unit, 11F: File control unit, 11J: Job management unit, 11P: Image processing control unit, 11S: Reading control unit, 11U: UI control unit, 11X: Job execution unit, 12: Document reading device, 13: Storage device (storage unit), 14: Image forming unit (image forming unit), 15: Scanner unit (document reading unit), 16: Document feeder (document transport unit), 17: Document table, 18: Front side reading window, 19: User interface unit (UI unit), 19I: Operation input device, 19D: Display device (display unit), 21: Communication circuit, 31: Document set tray, 32: Cover member, 33: Document output tray, 40: Image processing circuit, 41: Input processing circuit, 45: Document area determination circuit (document area determination section), 47: Output image generation circuit, 51: Front background color plate, 53: Back background color plate, 55: First carriage, 57: Second carriage, 59: Optical lens, 61: Image sensor, 63: Scanner motor, 65: Wire pulley, 67: Back side reading unit, 69: Lens image sensor unit, 100: Multifunction device, A: Document transport direction, B: Direction perpendicular to the document transport direction, C: Center line, D: Document, d1, d2: Edge, Dx: Document stack, L1, L2: Distance, P: Document set position, R1, R2, R3: Reading position, S: Gap, W: Distance (guide width)

Claims

1. a document reading unit that reads a document; a document transport unit configured to transport a document placed on the document in a document transport direction toward the document reading unit; a storage unit that stores in advance standard sizes relating to the long side length and short side length of each of a plurality of standard size documents; a document size detection unit that detects a vertical length of the document placed along the document transport direction and a horizontal length of the document in a direction perpendicular to the document transport direction; a document size determination unit that preliminarily determines in a first stage which of a plurality of standard sizes the size of the placed document corresponds to based on document size information relating to the combination of the vertical length and horizontal length detected by the document size detection unit; a document area determination unit; a display unit capable of displaying a screen for a mode for reading a standard size document and a mode for reading a non-standard size document; the document size determination unit determines, in a second stage after the first stage, whether the document size is a standard size or an irregular size based on the standard size determined in the first stage and the document size information; the document area determination unit determines a reading area for a document determined by the document size determination unit to be an irregular size in a mode different from that for a document determined to be a regular size; When the document size determination unit determines that the document is an irregular size, the document reading unit reads the document in a mode for reading irregular sizes, and then the display unit displays preview images of two cases: one in which an area corresponding to the regular size determined in the first stage is cut out, and the other in which the boundary of the document is cut out, and accepts the selection of either.

2. 2. The document reading device according to claim 1, wherein the document size determination unit determines that the document is of an irregular size if there is a difference between the vertical length of the standard size determined in the first stage and the vertical length related to the document size information, or between the horizontal length of the standard size determined in the first stage and the horizontal length related to the document size information, that exceeds a predetermined tolerance range.

3. A destination specification setting unit for setting a specific destination specification is further provided, The storage unit can store the plurality of standard sizes in advance according to destination specifications, 3. The document reading device according to claim 2, wherein when the document size information relates to a specific combination of vertical length and horizontal length, if the vertical length related to the document size information is within the range of the tolerance for a length predetermined for another destination different from the set specific destination specifications, or if the horizontal length related to the document size information is within the range of the tolerance for a length predetermined for the other destination specifications, the document size determination unit determines the document to be an irregular size in the second stage even if it was determined to correspond to a standard size for the specific destination in the first stage.

4. A destination specification setting unit for setting a specific destination specification is further provided, The storage unit can store the plurality of standard sizes in advance according to destination specifications, 3. The document reading device according to claim 2, wherein when the document size information relates to a specific combination of vertical length and horizontal length, if the vertical length related to the document size information is within the tolerance range for a length predetermined for another destination different from the set specific destination specifications, or if the horizontal length related to the document size information is within a predetermined small error range within the tolerance range for a length predetermined for the other destination specifications, the document size determination unit determines that the document is an irregular size in the second stage even if it was determined to correspond to a standard size for the specific destination in the first stage.

5. a reading control unit that controls the document reading unit; The document reading device according to any one of claims 1 to 4, wherein the reading control unit controls the document reading unit so that in a mode for reading standard sizes, a predetermined area corresponding to each standard size is used as the reading area, and in a mode for reading irregular sizes, the document reading unit determines the boundaries of the document from an image obtained by reading the entire area of ​​the document and cuts out the document area.

6. The document reading device according to claim 5, wherein the reading control unit controls the document reading unit in a mode for reading irregular sizes to read the smallest area possible for reading the entire area of ​​the document based on the standard size determined in the first stage and the document size information.

7. 7. The document reading device according to claim 1, wherein the display unit displays a user setting screen for setting either a mode for reading standard sizes or a mode for reading non-standard sizes.

Images