JP3433625B2 - Image reading device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus suitable for reading bound originals such as books, magazines and documents.

[0002]

2. Description of the Related Art An image reading device called a book scanner has been commercialized. In this apparatus, an image pickup system is arranged above the document table, and an open space having a height of several tens cm exists between the document table and the image pickup system. When reading a book-shaped original such as a book or a magazine (referred to as a "book original"), the user sets the book original on the original table in an open state. In response to the start key being turned on, scanning of the spread surface, which is the surface to be read (original surface), is started, and the read images are sequentially output to an external device. If the external device is a printer, a copy image is formed in real time. When the book scanner is used, the pages can be turned on the document table, so that the efficiency of reading a large number of pages can be improved.

Unlike a sheet document, the document surface of the book document (the surface to be read) is curved. That is, the height of the document surface varies depending on the position in the left-right direction (spread direction).
As a result, the read image is distorted according to what is called out-of-focus or curved state. The book scanner measures the curved state (height distribution of the document surface), and performs focus adjustment and distortion correction according to the result. A read image having the same image quality as when reading a sheet document is output to the external device. As a method of measuring the curved state of the document surface, a method of determining the shape of the end face, which is a portion called "head" in a book, that is, the height of the document at each position in the spread direction by photographing the end face is used. Of calculating the height (Japanese Patent Laid-Open No. 5-161002)
No.), and the slit light projection method (Japanese Patent Laid-Open No. 5-161002) used in three-dimensional measurement.

[0004]

The book scanner is also useful for reading a document in which one side (the left side in the case of horizontal writing) of paper is bound with staples or fasteners. Pages can be turned over on the manuscript table as in the case of a book. In a general office, the purpose of reading a document is often to reproduce the entire document. That is, the work of copying each page of a document and creating a bound document similar to the original is frequently performed. Therefore, for example, as the reading size of a document in which A4 size sheets are bound, not the spread A3 size but the A4 size which is the original sheet size is preferable.

The conventional book scanner is provided with a so-called book division mode for separately outputting the left and right pages of a spread. However, the user has to specify the normal mode (sheet original mode) in which the left and right pages are treated as one page image or the book division mode.

It is an object of the present invention to reduce the time and effort required to read a two-page spread original and to make it easier to use.

[0007]

According to another aspect of the present invention, there is provided an apparatus for supporting an original, an image pickup system for converting an image of the original into an electric signal, and an image of the original is projected on an image pickup surface of the image pickup system. An image reading apparatus having an optical system, wherein an open space for setting a document exists between the document table and the optical system, the image reading apparatus comprising:
Measuring means for measuring the height distribution in the spread direction of the document surface,
Paper of specified size placed on the platen in a double-page spread
Calculate the creepage distance of the double- page spread original in the double-page spread direction based on the height distribution of the original surface of the original.
Means, detected creepage distance and closest to the creepage distance
By comparing the width of the specified size paper with that width
Ri, before Symbol viewed open document, and means for determining whether or not a small Book Original than twice the size when spread size is not wide open, as the output size of the spread original scanned image, not wide open is spread size If it is determined that the spread document is smaller than twice the size of the original size, the specified size that is closest to the spread size of the spread document is divided into two equal parts in the spread direction, otherwise, the specified size that is closest to the spread size. And means for automatically setting.

An apparatus according to a second aspect of the present invention includes a document table for supporting a document, an image pickup system for converting a document image into an electric signal, and an optical system for projecting the document image on an image pickup surface of the image pickup system. An image reading apparatus having a structure in which an open space for setting a document exists between the document table and the optical system, and how to open a document surface of a document placed on the document table
Measuring means for measuring the height distribution in the
Ri means for discriminating whether the original is a spread manuscript on the basis of the curved state of the document surface of the document the placed on a platen obtained, staples from read- image of a document placed on the document table Determines whether or not the original is a stapled stapled original by extracting the image
Indicates if the document is a staple document
A means for setting a flag and a document placed on the document table
The flag is set as the output size of the scanned image of
It is determined that the document is a two-page spread document
In this case, there is provided means for automatically setting the specified size that is closest to the size of the two-page spread of the document in the two-direction spread direction, and otherwise set the specified size that is closest to the two-page spread size.

[0009]

DETAILED DESCRIPTION OF THE INVENTION

[System Configuration] FIG. 1 shows a copying system CS according to the present invention.
It is a block diagram of.

The copying system CS comprises a book scanner 1 suitable for reading books and documents, a printer 2 connected to the book scanner 1 via a cable 4, and a stapler 3 for binding printed sheets with staples. There is. The printer 2 is a page printer, and a paper reversing mechanism 2 for printing images on the front and back sides of the paper, respectively.
Equipped with 50. The stapler 3 is attached to the printer 2.

FIG. 2 is a perspective view showing the external appearance of the book scanner 1, FIG. 3 is a schematic view of reading by the book scanner 1, and FIG. 4 is a view showing a state in which a double-page spread single-point stop original DS1s is set.

The book scanner 1 includes a main body housing 10 for accommodating a power supply circuit, a dark-colored document stand 20 for supporting a document, and an image pickup unit 3 for converting a document image into an electric signal.
0 and a lamp unit 40 for illuminating the original. The document table 20 is arranged on the front side of the main body housing 10. An operation panel OP is provided on the upper end of the front surface of the main body housing 10, and the operation panel O
A main switch 51 is provided on the right side surface facing P. The operation panel OP has a liquid crystal display 91.
Along with the operation mode and reading conditions (output paper size,
A switch for specifying the magnification, the number of output sheets, the density, etc. is arranged. The image pickup unit 30 is arranged above the document table 20 and is supported in a cantilevered manner by a column 12 extending upward from the upper surface of the main body housing 10.
The lamp unit 40 is fixed to the column 12 at a position on the lower surface side of the imaging unit 30. A space 80 between the document table 20 and the image pickup unit 30 is open to a free space outside the apparatus, and has a sufficient space for setting a book document DB. The distance between the document table 20 and the lower surface of the imaging unit 30 is 30 cm or more. Platen 20
An armrest 25 is provided on the front side of the.

A projection unit 18 is arranged on the upper surface of the original table 20 for measuring the curved state of the reading target surface (original surface) S1 of various originals. Projection unit 18
Is a projection plate 1 extending along the rear edge of the document table 20.
8a and a projection plate 18b extending in the front-rear direction in the right half area of the document table 20. The surface of each projection plate 18a, 18b is a glossy surface, and is 45 ° with respect to the upper surface of the document table 20.
It is an inclined surface. When the book document DB is set in the direction shown in FIG. 2, the book document D is displayed on the projection plate 18a.
One end surface S3 in the direction orthogonal to the spread direction in B
Appears on the projection plate 18b, and one end face in the two-way spread direction (this is referred to as a side face) S2 appears. Then, the projection plates 18a and 18b in that state are photographed together with the original image.

In FIG. 2, the image pickup unit 30 has a CC
A line sensor 31 formed of a D array, an imaging lens 32,
And a mirror 33. An original image is projected onto the light receiving surface of the line sensor 31 by the optical system OS including the mirror 33 and the imaging lens 32. The imaging lens 32 is
It is provided so as to be movable in the front-rear direction, and is positioned by an AF mechanism (lens drive unit) 132. The line sensor 31 is attached to a movable body of a sub-scanning mechanism, which will be described later, and moves in parallel along the left-right direction (sub-scanning direction) M2 while keeping the arrangement direction of the CCD elements up and down. This parallel movement captures a two-dimensional original image. That is, in the book scanner 1, the movement of the line sensor 31 forms a two-dimensional image pickup surface. When an area sensor is used instead of the line sensor 31, its light receiving surface becomes the image pickup surface. The main scanning direction of the original image is the front-back direction on the original table 20 and the vertical direction on the imaging surface. In this embodiment, the imaging unit 3
0 and the above-mentioned projection unit 18 constitute a photographing means for measuring the curved state of the document surface S1. By using the imaging unit 30 to measure the curved state,
The structure is simplified.

When reading the book document DB, the user places it on the document table 20 with the left and right sides thereof facing upward. At that time, the boundaries of the left and right pages are aligned with the center of the document table 20 in the left-right direction, and the book document DB is pressed against the lower end edge of the projection plate 18a to perform the front-back positioning. The boundary between the projection plate 18a and the document table 20 serves as a reference line for setting the document, and the center of the reference line is the reference position. In addition, as shown in FIG.
When reading S1s, the user places the document surface S1 at the center of the document table 20 in the left-right direction. Here, the double-page spread single-point stop document DS1s is a document in which at least one sheet is turned over, and is composed of a plurality of sheets with one corner bound by staples or the like. The document surface S1 of the one-page spread single-point stop document DS1s is the upper surface of the uppermost unfolded sheet. That is, of m (m ≧ 2) sheets, k (1
≦ k <m) (k when up to the ninth sheet is turned over)
The upper surface of the (+1) th sheet is the document surface S1.

FIG. 5 is a block diagram of the sub-scanning mechanism 131.
The sub-scanning mechanism 131 is an electric screw type slide mechanism, and includes a motor 311, a feed screw 312, a scanner 313,
It is composed of a guide rail 314 and the like. The line sensor 31 is attached to the scanner 313. In order to detect the position of the scanner 313, the photo interrupter S3 is provided as a position sensor on one end side and the other end side in the moving direction M2.
11, S312 are arranged, and the light shield plate 3 is attached to the scanner 313.
15 is attached.

FIG. 6 is a block diagram of the AF mechanism 132. A
The F mechanism 132 is an electric cam type slide mechanism, and includes a motor 321, a cylindrical cam 322, and a ring slider 32.
3, a guide rail 324, a follower 325, and the like. As the cam 322 rotates, the slider 323 engaged with the cam 322 via the follower 325 moves in parallel. The imaging lens 32 is attached to the slider 323. Cam 322 corresponding to the position of slider 323
Of the photo interrupters S321 and S322 as position sensors near the cam 322 in order to detect the rotational angle position of the cam.
Are arranged, and the light shielding plate 326 is attached to the cam 322. [Type of Original] FIG. 7 is a diagram showing an example of a display form of the type of original.

The book scanner 1 has a function of discriminating the type of the set original and performing a reading operation according to the type. The types that the book scanner 1 discriminates are as shown in Table 1. Table 1 also shows flag states corresponding to each type.

[0019]

[Table 1]

As shown in Table 1, originals are roughly classified into non-staple originals and staple originals. Documents bound by a member for simple binding represented by staples are staple originals, and originals other than staple originals are non-staple originals. Non-staple manuscripts are classified into "book manuscripts" that are full-fledged documents such as books and magazines, and "sheet manuscripts" that are single-cut documents. On the other hand, staple originals are bound at a plurality of locations (generally two locations) that are separated along one side (generally the left side) of the paper, and at one corner (generally the upper left) of the paper. It is also classified as a "single-point stop original". Further, each of the two-point stopped original and the one-point stopped original is classified into two types, that is, a closed state where no sheets are turned over or a spread state where at least one sheet is turned over. That is, the book scanner 1 discriminates between six types of originals: a book original, a sheet original, a closed two-point stop original, a two-page spread stop original, a closed one-point stop original, and a one-page spread stop original. Note that in the present embodiment, although it is a non-staple document in appearance such as a notebook (university notebook, etc.), it is a spread document having a wider binding margin than a book (this is referred to as a special book document). In this case, the reading operation similar to that of the two-page spread two-page stop original is performed.

On the liquid crystal display 91 of the operation panel OP, figures Z1 to Z6 representing each of the six types of originals are displayed, and when the type determination is completed, the type of the original to be read is highlighted by inversion such as black and white. It In the example of FIG. 7, the graphic Z1 representing the book document is highlighted.
In addition, as a modification of the display mode of the type of the original, there are a mode in which LEDs corresponding to the respective types are provided to selectively emit the light, and a mode in which only the determined one type is displayed by a figure or a character. [Method of Determining Type of Original] FIG. 8 is a diagram showing an attention area in the presence / absence of staple st, FIG. 9 is a diagram showing the height distribution of three types of spread originals, and FIG. FIG. 11 is a diagram for explaining the method of discriminating the type, and FIG. 11 is a perspective view showing an example of the spread single-point stop original DS1s.

In order to discriminate between the non-staple document and the staple document, it is sufficient to check whether or not the read image has a staple image. Usually, the staple is applied to the margin of the paper, and the color of the staple (generally silver) is different from that of the paper. Therefore, the staple image can be extracted by paying attention to the difference in density of pixels. When extracting, as shown in Fig. 8,
From the viewpoint of processing efficiency, it is preferable to limit the attention area to an area Es (such as a hatched portion in the drawing) where the staple st is expected to exist in the document.

Manuscripts in a spread state (including book manuscripts)
In order to discriminate between the original and the closed original (including the sheet original), the curved state (height distribution) of the upper surface of the original in the sub-scanning direction may be examined. The upper surface of the two-page spread original is curved, while the upper surface of the closed original is substantially flat. In addition, FIG.
As shown in (A), in the book document DB, the inclination direction of the upper surface of the document is reversed at the center (reference position) of the document table 20 in the sub-scanning direction. Even in the two-page spread document DS2s, as shown in FIG.
As shown in (B), the direction of inclination greatly changes at or near the reference position. When the left end of the document surface S1 is the reference position, a position apart from the reference position by the overlapping width α (width of the area where the document surface S1 is hidden) is the inflection point of the inclination. On the other hand, in the one-page spread original document DS1s, the distance w'between the position (inflection point) where the inclination direction changes greatly and the reference position is relatively large. The distance w'is an overlapping width (width of the area where the document surface S1 is hidden) β that is greater than 1/2 of the width w of the document surface S1.
However, it is a short value (w '= w / 2-β). Therefore,
If there is an inflection point in the vicinity of the reference position (a range defined in consideration of the overlapping width α and the setting error), the reading target is the book document DB or the two-page spread document DS2s.

Book manuscript DB and two-page spread manuscript DS
In order to determine 2 s, the creepage distance of the upper surface of the document in the sub-scanning direction (that is, the spread direction) may be checked. This creepage distance corresponds to the distance between both ends when the upper surface of the original is assumed to be a flat surface, and is calculated by the calculation that linearly approximates a curve for each minute section based on the height distribution data and sums the approximate values of all sections. it can. If the obtained creepage distance is close to and shorter than the width of a specified size such as A3 / B4, which is the size of a commonly used paper, the document to be read is a two-page spread double-page stop document DS.
It can be regarded as 2s. The reason is that in the two-page spread double-stop document DS2s, even if the width w of the document surface S1 is, for example, the A4 size width, the two-page spread width W
Is not twice the width of the A3 size as the A4 size, but is shorter than the width of the A3 size by twice the overlapping width α (2α).

The difference between the two-dimensional shape of the original document may be used for distinguishing the two-page spread original document DS1s from the closed original document (including the sheet original document). For a closed document such as a sheet document or an unfolded staple document, the plan view shape is a quadrangle having the same size as the document surface. On the contrary,
The plan view shape of the one-page spread single-point stop original DS1s is a shape in which the original surface and the back surface of the folded paper are combined as shown in FIG. 10, and is more complicated than a quadrangle. The determination procedure is as follows. First, a photographed image (upper surface image) G1 of the upper surface of the original is extracted from the read image G0 of the original surface. Since the photographed image G20 of the document table 20 has a dark color, the top image G1 can be easily extracted by the brightness discrimination. Next, the width of the extracted upper surface image G1 on the front side (lower side in FIG. 10) of the document table is obtained. For example, paying attention to a position where the distance from the edge is 5 cm and a position where the distance is 10 cm, the widths w1 and w2 at each position are obtained, and the average value thereof is used as the measured value of the width. Usually each width w
1 and w2 are equal. The focus on the front side is that if the focus is on the rear side, the correct document size cannot be obtained in the case of the spread single-point stop document DS1s. The error can be reduced by paying attention to a plurality of points. Then, the specified size of the width closest to the obtained width is determined as the document size.
Finally, the size of the top image G1 is compared with the document size,
When the upper surface image G1 is large, that is, when the upper width of the upper surface image G1 is larger than the lower width in FIG.
It is determined to be S1s. Note that it is preferable to use the read image G1 after performing the image correction corresponding to the curvature of the document surface S1 and the positional deviation (tilt) of the setting for the determination based on the read image G1.

The one-page spread single-stop original DS1s can be discriminated from other types of originals by examining the curved state in the main scanning direction. As shown in Figure 11,
In the double-page spread single-point stop original DS1s, the original surface S1 is curved so that the vicinity of the portion bound by the staple st or the like rises, and not only the sub-scanning direction M2 but also the main scanning direction M1.
Also, the height varies depending on the part. Generally, as the number of flipped sheets increases, the curvature becomes more remarkable. The curved state in the main scanning direction is based on the captured image of the projection plate 18b.
The measurement can be performed in the same manner as the measurement of the curved state in the sub-scanning direction described later. If the height distribution in the main scanning direction M1 is a bulge on the rear side on the platen, the read target in that case is the spread single-point stop document DS1s. If the discrimination method based on such a height distribution and the discrimination method based on the above-described plan view shape are used together, the reliability of discrimination can be improved. That is, even if the paper size is messyly overlapped or the document size is erroneously set due to an extremely slanted setting, the two-page spread single-stop original DS1s and other originals are finally correctly discriminated. be able to. [Measurement of Height Distribution] FIG. 12 is a diagram for explaining the method of measuring the height distribution of the document surface, and shows the read image and the luminance distribution of the line of interest in the case of the book document DB. The broken line in the figure indicates the position of the line of interest.

The read image G0 is a photographed image (top image) G1 of the upper surface of the book document DB, a photographed image G20 of the document table 20,
It is composed of a captured image G18a of the projection plate 18a and a captured image G18b of the projection plate 18b. The image G181 of the photographed image G18a is the set book manuscript DB.
The shape of the end surface S3 on the rear side in the main scanning direction is shown. An image 180 other than the image (end face image) G181 in the captured image G18a is a background image reflected on the projection plate 18a.
The captured image G18b of the projection plate 18b includes an image G182 of the right side surface of the book document DB.

As described above, since the original table 20 is colored in a dark color, the photographed image G20 becomes a darker image than other images. The background image 180 is also a darker image than the end face image G181. Therefore, the upper surface image G1 and the end surface image G181 can be extracted by determining the brightness.
Specifically, the luminance (pixel value) is sequentially checked for each line from the leading pixel in the main scanning direction, and the leading pixel position (pixel number) n1 in the range in which the luminance exceeds the first threshold th1 and the luminance are Pixel positions n3 and n4 on the leading side and the trailing side of the range exceeding the threshold value th2 (th2> th1) of 2 are detected. The number of pixels between the pixel position n1 and the known pixel position n2 corresponding to the front edge of the projection plate 18 is the document surface S1 in the line.
, And the number of pixels between the pixel positions n3 and n4 corresponds to the document size in the main scanning direction. The actual size can be obtained by a calculation that divides the number of pixels by the imaging resolution. The curved state of the document surface S1, that is, the height distribution is specified by a set of data indicating the height of the document surface S1 in each of all the lines. Further, the respective positions of the first line and the last line where the pixel positions n3 and n4 are detected correspond to both end positions of the document in the sub-scanning direction. [Correction of Image Distortion] In FIG. 12, the upper edge and the lower edge of the top image G1 of the read image G0 are curved because the height of the document surface S1 is not constant. That is, a subject closer to the imaging surface is captured larger than a subject far away. If the document surface S1 is curved, the image is distorted. Therefore, the book scanner 1 performs preliminary scanning to obtain a height distribution, and corrects the read image G0 during the main scanning to an image when the height of the document surface S1 is constant (image processing). Distortion correction). In the book document DB and the double-page spread two-point stop document DS2s, the height in the main scanning direction at each position in the sub scanning direction can be regarded as substantially constant. In the case of these originals, a fixed distance (for example, 5c) above the original table 20 in the main scanning direction.
m) as a reference plane, and the top surface image G according to the height difference between the reference plane and the document surface S1 at each position in the sub-scanning direction.
Magnify 1 In the sub-scanning direction, the upper surface image G1 is scaled according to the ratio of the creepage distance of the document surface S1 to the projection distance of the document surface S1 on the document table 20 for each minute section. On the other hand, in the one-page spread original document DS1s, there is a region where the height in the main scanning direction is not constant as described above, so it is necessary to correct the image distortion caused by it.

FIG. 13 is a diagram showing a correction target area in the one-page spread original document DS1s. Thick solid lines in the figure represent the height distribution of the document surface in each scanning direction. The document surface S1 is divided into two in the sub-scanning direction at the pixel position na at the boundary between the curved portion on the left side and the flat portion on the right side in the height distribution in the sub-scanning direction. When the document surface S1 is divided into two in the main scanning direction at the pixel position nb at the boundary with the lower flat portion, the document surface S1 is divided into four areas A, B1, B2, B3. Of these areas, the upper left area A is a “curved area” that requires distortion correction. The lower left area B1, the upper right area B2, and the lower right area B3 are “flat areas” similar to the sheet original. However, the height of the flat area increases as the number of sheets on the back side of the document surface S1 increases. The book scanner 1 performs, on the curved region A, a scaling process similar to the correction in the sub-scanning direction in the case of the book document DB in the main scanning direction. [Focusing] Book Scanner 1
In accordance with the height distribution of the document surface S1 measured by the method described above, the focus adjustment of photographing is performed during the main scanning. In the present embodiment, the line sensor 31 and the sub-scanning mechanism 1
Since line-sequential image scanning is performed by 31 and
It is possible to adjust the focus for each line. However, it is not always necessary to make adjustments for each line, and adjustments may be made for a plurality of lines to reduce the control load. The AF mechanism 132 moves the imaging lens 32 in accordance with a control signal given in accordance with the progress of the sub-scan. Basically,
The imaging lens 3 when the position of each line on the document surface is high
Move 2 closer to the document surface, and conversely move it away when it is low. The position of the imaging lens 32 can be calculated by the following equation, which is a known geometrical conditional equation.

1 / f = (1 / a) + (1 / b) f: focal length of imaging lens a: image plane distance (see FIG. 3) b: field distance (see FIG. 3) 1-page spread In the case of the stop original DS1s, the book original DB
Unlike the two-page spread two-point stop document DS2s, there is a curved region A in which the line height is not constant, so the following focus adjustment is performed.

FIG. 14 is a schematic diagram of the height distribution in the main scanning direction in the one-page spread original DS1s. Curved area A
Also, the height as a reference for focusing is determined according to the size relationship between the lengths (the number of pixels) Δn1 and Δn2 of the flat region B1 in the main scanning direction. When the flat area B1 is relatively large,
For example, the length Δn2 is ¼ or more of the total length (Δn1 ≦ 3Δn
In the case of 2), focus adjustment is performed assuming that the height h1 of the flat area B1 is the height of the line of interest. That is, the flat area B1 in which the entire area is in focus is emphasized to reduce the out-of-focus of the entire document. When the curved region A is relatively wide, for example, Δn1> 3Δn2), the height h expressed by the following equation is assumed to be the height of the line of interest, and focus adjustment is performed.

H = h1 + kΔh (0 <k <1) Δh: The coefficient k on the right side of the height difference is a parameter set according to the height distribution, and in many cases the approximate value is 0.5. .

FIG. 15 is a diagram showing an example of a height setting method in focus adjustment. The diagonal lines in the figure show the focusing range when the heights ha and hb are focused. In setting the coefficient k described above, the focus area is made wider in consideration of the depth of focus of the imaging lens 32.
In the example of FIG. 15, when focusing on the height ha,
Two points on the document surface are in focus, and the lengths of the respective points in the main scanning direction are x1 and x3. On the other hand, when focusing on the height hb, the length of the focusing range is x2.
In this example, (x1 + x3)> x2, so the height hb
It is better to focus on the height ha rather than the height ha.

FIG. 16 is a diagram for explaining another example of focus adjustment. The above description of focus adjustment is based on the premise that the main scanning is performed only once.
When performing two main scans, the position to be focused is set each time. For example, at the first time, the height of the flat area B1 is focused, and at the second time, the curved area A
Focus on the height between the top and the flat area B1. In the second time, the coefficient k may be optimized according to the bending state as described above, or a fixed value (for example, 0.5) may be set as the coefficient k. The main scanning is performed by synthesizing the captured image of the flat area B1 in the first read image and the captured image of the curved area A in the second read image to generate a read image for one page. 1
It is possible to obtain a read image of higher quality than in the case of performing only once. It should be noted that the main scanning can be performed three or more times to improve the reading quality, but as the number of times increases, the time required for reading becomes longer. [Detection of Overlapping Area of One-page Spread Fixed Original] In the one-page spread original DS1s, the corner of the document surface S1 where the sheets are bound is hidden from the line sensor 31. That is, the flipped sheet partially overlaps the document surface S1. Therefore, if there is an image on the back side of the flipped sheet, the image is included in the read image although it is unnecessary. Further, when the overlapped portion of the flipped sheet (referred to as an “overlap area”) is bent downward as shown in FIG. 11, a shadow is generated at the corner of the read image.
Therefore, the book scanner 1 detects the overlapping area based on the read image and erases the captured image of the overlapping area in the read image. Specifically, the pixel value of the captured image in the overlapping area is replaced with the background density value of the document surface S1 measured by the preliminary scanning.

FIG. 17 is a diagram showing a method of detecting the overlapping area Ew. Here, the quadrangle abcd is an area having a size corresponding to the document surface, the triangle aef is an overlapping area Ew, and the pentagon ijkef is an area corresponding to a rolled sheet. First, the intersection of the line in the sub-scanning direction including the point b and the line in the main-scanning direction including the point d is stored as the point A. Next, the intersection of the line in the main scanning direction including the point k and the line segment ab is defined as point e, and the intersection of the line in the sub scanning direction including the point i and the line segment ad is defined as point f.

In this embodiment, the triangular areas are approximately overlapped with each other to form the overlapping area Ew. However, when the height of the original is directly measured by a distance measuring sensor or the like, it is possible to accurately measure the height of the original by performing two-dimensional measurement. The overlapping area Ew can be specified. The overlapping area Ew is specified by using height distribution information in the sub-scanning direction and the main-scanning direction obtained from the stereoscopic image capturing information by the projection plates 18a and 18b instead of or together with the planar image capturing information. You may. [Structure of Signal Processing System] FIG. 18 is a functional block diagram of the copying system CS.

The book scanner 1 and the printer 3 have CPUs 101 and 201 for controlling the respective controls. These CPUs 101 and 201 are microcomputers. In the copying system CS, the CPU 101 gives the staple mechanism 305 of the stapler 3 operating conditions such as the staple position and the number of staples.

In the book scanner 1, the photoelectric conversion signal output from the line sensor 31 is converted into the AD converter 102.
Is converted into, for example, 8-bit image data and input to the image processing circuit 103 in the pixel arrangement order. The image data that has been subjected to processing such as shading correction in the image processing circuit 103 is further stored in the buffer memory 105 after being further processed by the compressor 104. The compressed image data read from the buffer memory 105 at the appropriate time is decompressed by the decompressor 105 and then stored in the memory 107. The memory 107 can store one image of the maximum read size. The maximum read size is, for example, A3
It is the size (spread size of an A4 size book).

Image data in memory 107 (read image)
Is transferred to the correction block 110, subjected to a predetermined correction process, and then stored again in the memory 107 in the overwrite format as output image data. The correction block 110 includes an A correction circuit 111 for carrying out an image shift for the two-page spread original DS2s and a one-page spread original DS1 as described later.
The B correction circuit 112 is responsible for image shifting for s and erasing the image in the overlapping area Ew, the C correction circuit 113 is responsible for rotation / manual movement processing for correcting image tilt and shift, and the original surface is curved. The D correction circuit 114 is responsible for scaling processing including distortion correction. Further, during the preliminary scanning, the CPU 101 causes the memory 107
The necessary image data is fetched from the device, and the processing necessary for control such as height distribution / background density / size measurement, document type determination, and correction content setting is performed.

The output image data stored in the memory 107 is transferred to the data conversion unit 202 of the printer 2. The data conversion unit 202 uses the output image data for image formation.
It is converted into value data and sent to the print head 203. The read image is printed out by the interconnection operation of the print head 203 and the print engine 204. In the double-sided copy mode, read images are printed on the front and back sides of one recording sheet. Then, according to the designation, the printed recording paper is bound by the stapler 3 or discharged without being bound.

The CPU 101 of the book scanner 1 includes an operation panel OP, a switch group 50, and a sub-scanning mechanism 13.
1, an AF mechanism 132, a lamp control circuit 140, etc. are connected. The switch group 50 includes a main switch 51
In addition, a start switch and a staple switch for selecting the necessity of stapling are included. A necessary clock is supplied from the timing control circuit 109 to each component of the signal processing system including the line sensor 31 and the CPU 101. [Image Shift of Two-Page Spread 2-Point Original Document] FIG. 19 is a schematic diagram of the function of the A correction circuit 111, and FIG. 20 is a block diagram of the A correction circuit 111. 19B to 19D, the thick solid line frame indicates the image storage area of the memory 107, and the diagonal line indicates the captured image of the document.

In the two-page spread double-stop original DS2s,
As shown in FIG. 19 (A), the actual width d of the sheet turned to the left is smaller than the width w of the sheet by the overlapping width α. Therefore,
In order to obtain a print result having the same layout as in the case of the book manuscript DB, the overlapping width α is taken into consideration and the result shown in FIG.
As shown in (D), the read image is divided into two and divided into right and left. As a point, first, the read start line from the memory 107 is shifted by 2α. This virtually shifts the entire read image to the left [FIG. 19 (B)].
(C)]. Next, writing to the memory 107 is advanced in the order of reading, and when the number of lines corresponding to the width d is reached, a delay of 2α is applied to the data of the subsequent lines. In the delay period, the background density data is written in the memory 107. Then, the delayed line data is stored in the memory 107.
Is written in [FIG. 19 (D)].

The A correction circuit 111 includes a settable counter 501 for counting the line clock CK in parallel with the reading from the memory 107, a delay circuit 502 for delaying the image data D107 read from the memory 107, and a delayed signal. The selector 503 outputs the image data D107 or the background data Dw to the memory 107. The settable counter 501 has a count value and CP.
The delay amount CT and the select signal SE having the values shown in FIG. 20B are output as control signals for the delay circuit 502 and the selector 503 in accordance with the designated values (overlap width α and width d) from U101. The background data Dw is given from the CPU 101 to the selector 503.

The CPU 101 uses the address shifted by 2α from the start address of the image storage area in the memory 107 as the start address, and reads the image data D107 from the start address to the final address (N) of the image storage area. In parallel with this, the output data of the selector 503 is overwritten in the image storage area from the start address to the end address in the output order. [Image Shifting of Single-Spread Single-Stop Document] FIG. 21 is a schematic diagram of the function of the B correction circuit 112, and FIG. 22 is a block diagram of the B correction circuit 112.

For the one-page spread original DS1s,
Since the setting is made so that the vicinity of the center of the left and right of the sheet is aligned with the reference position of the document table 20 instead of the edge of the sheet, the photographed image of the document in the read image is shifted from the right end of the reading range to the left as shown in FIG. There is. Therefore, in order to prevent a part of the image from being lost during printing, the book scanner 1 is provided with a B correction circuit 112 that shifts the image to the right corresponding to the shift amount Δy.

The B correction circuit 112 selects a settable counter 521 for counting the line clock CK in parallel with the reading from the memory 107, a selector 522 for selecting one of the image data D107 from the memory 107 and the background data Dw from the CPU 101. , And a delay circuit 523 which delays the data selected by the selector 522 and outputs the delayed data to the memory 107. The settable counter 501 gives a predetermined select signal SE to the selector 503 according to the count value and the specified value (overlap width α and width d) from the CPU 101. The delay amount δy is given to the delay circuit 523 from the CPU 101. [Copying of Staple Original] FIG. 23 is a diagram showing a copy mode of three types of staple originals.

The copying system CS of this embodiment has a function of making a stapled copy of a staple original in the same manner as the original. If the document is a one-page spread one-point stop document DS1s, the upper left corner of the paper on which the read image is printed is bound, and if it is a two-page spread two-point stop document DS2s, the left side portion is bound. This function is most suitable for the work of creating multi-part documents such as handouts for meetings. Usually, when the user desires a copy similar to the original, the user starts by reading the cover portion of the original. That is, when the stapled original is read for the first time, the original type is "closed 2".
It becomes "point-fixed original" or "closed one-point-fixed original" and becomes "double-page spread two-point-fixed original" or "closed one
Therefore, in the double-spread state, it is impossible to detect staples by analyzing the captured image, but by storing the results of staple detection in the closed state, the double-spread original becomes a staple document. Can be estimated.

Spread 2 in which the reverse side of the flipped sheet is blank
In the case of the spot-stop single-sided document DS2sa, the right half G1R of the read image G1 that has undergone image processing such as distortion correction is printed on the recording paper P of a size corresponding to the magnification (half the spread size at equal magnification). In the case of a two-page spread double-sided document DS2sa in which an image exists on the back side of the flipped sheet, the operation differs depending on the copy mode. In the single-sided copy mode, the left half G1L and the right half G1R of the read image G1 are printed on different recording sheets P in order. In the double-sided copy mode, the left half G1 of the read image G1
L and the right half G1R of the next read image G1 'are printed separately on the front and back sides of the same recording paper P. Also, in the case of the one-page spread original document DS1s, the right half G1R of the read image G1 that has undergone the above-described image shift is printed on the recording paper P. [System Control] Next, control in the copying system CS will be described based on a flowchart.

FIG. 24 shows the CPU 101 of the book scanner 1.
5 is a flowchart of a main process executed by the. This main process, when the user performs some operation,
It is executed as an interrupt process corresponding to the operation.

First, interrupts are prohibited and subsequent operations are not accepted (# 1), and flags and the like are initialized (# 2). The operated switch (SW) is discriminated and the process corresponding to the operation is performed (# 4, # 6 to # 10). When the processing is completed, the interrupt prohibition is released and the interrupt routine is exited (# 5).

When the start switch is turned on, reading control is executed to read the original image and send the image data to the printer 2 (# 4). When the staple switch is turned on, a staple process for controlling the stapler 3 is executed (# 6). With respect to the paper switch, the size setting of the recording paper P is switched in a circular format (#
7). The setting options are "Auto", "A4", and "A3".
Is one. For the document switch, the document mode setting is switched (# 8). There are two options: "automatic discrimination" and "single-sided". Here, the single-sided mode is a mode suitable for the one-page spread document DS1s, and the auto-discrimination mode is a mode in which the CPU 101 discriminates the type of the document and sets operating conditions. In addition, the copy mode switching process is executed in response to the copy mode switch being turned on (#
9). When a switch other than the above switches is operated, other processing is executed. FIG. 25 is a flowchart of the copy mode switching processing subroutine of FIG.

First, the copy mode is switched (# 9
A). There are two options: "single-sided" and "double-sided". The reread flag is initially reset (# 9B), and the document mode is checked (# 9C). If the original mode is the single-sided mode, the process directly returns. If it is the auto-discrimination mode, then check the copy mode (# 9D),
In the double-sided copy mode, the reread flag is set (# 9E). The rereading flag indicates whether or not it is necessary to print the left and right pages of the two-page spread original by arranging them on the front and back sides of the recording sheet or side by side on one side of the two-page spread recording sheet.

FIG. 26 is a flow chart of the staple processing subroutine of FIG. First, the one-point stop flag ST1p holding the set / reset state at the time of the previous reading is reset (# 6A). If the latest stapling detection result is 2-point stopping, the stapling position for the recording paper P is set to a position equivalent to the stapling position stored at the time of stapling detection (# 6B, # 6).
C). Then, the stapler 3 is driven to bind the recording paper P, and the process returns. On the other hand, if the result of stapling detection is one-point stopping, the stapling position on the recording paper P is set to a position equivalent to the original and the recording paper P is bound (# 6).
E, # 6F). Then, the one-point stop flag ST1p is set and the process returns (# 6G).

FIG. 27 is a schematic flow chart of the read control subroutine of FIG. The lamp control unit 140 is instructed to be turned on (# 4A), and the preliminary scanning is controlled (# 4B). Subsequently, a read image is read from the memory 107 and a document detection routine for determining the document type is executed (# 4C). The main scanning including focus adjustment is controlled (# 4D), and the image processing for correcting the read image obtained by the main scanning is performed (# 4D).
E). An instruction to turn off the illumination lamp is given (# 4F), a data output process is executed, and the process returns (# 4G).

The contents of the processing (subroutine) deeply related to the present invention in the read control routine will be described in more detail below. FIG. 28 is a schematic flowchart of the document detection subroutine of FIG.

First, the shape of the end face of the document in the main scanning direction is detected based on the photographed image of the projection plate 18a, and the height distribution in the sub scanning direction is measured (# 31). Next, the shape of the end face of the document in the sub-scanning direction is detected based on the captured image of the projection plate 18b, and the height distribution in the main scanning direction is measured (# 31). Next, the size of the original in plan view is measured by using the density difference between the original table 20 and the original (# 33), and the background density is measured by obtaining the frequency distribution (density histogram) of pixel values (# 3).
4). After that, the type of the original is discriminated using the measurement result (# 35), and the discrimination result is displayed on the liquid crystal display of the operation panel OP (# 36).

29 and 30 are flowcharts of the original type discrimination subroutine in FIG. FIG. 29
As shown in FIG. 9 based on the height distribution data in the sub-scanning direction.
As described above, it is checked whether or not there is a curved inflection point near the center (# 501).

If there is an inflection point, the original size in the sub-scanning direction is obtained by the operation of extending the curved surface to a flat surface (# 50).
2), and compare with the specified size such as B4 and A3 (# 50
3). If the document size is equal to the specified size, the target of this reading is determined to be the book document DB, and the book flag BK is set (# 504). And the book manuscript D
The book process corresponding to B is executed (# 505), the correction content of the distortion in the sub-scanning direction is set, and the process returns (# 50).
6). If the document size is smaller than the specified size in step # 503, the staple flag ST is checked (# 507). When the staple flag ST is set, it is determined that the document to be read is a spread 2-point stop document DS2s, and the 2-point stop flag ST2 is set (# 50).
8). When the staple flag ST is not set, it is determined that the reading target is a special book original and the special book flag BK2 is set (# 510). The 2-page spread processing (# 509) is executed regardless of whether the document is a 2-page spread original or a special book document, and the process proceeds to step # 506.

On the other hand, if the inflection point is not near the center in step # 501, a subroutine (# 511) for determining the original area is executed as shown in FIG. 30 to determine the original plane shape and the prescribed shape. The comparison is made (# 512). If the original has a prescribed shape (rectangular), the process proceeds to step # 519, and staple detection is performed for a partial area Es (see FIG. 8) of the original. If there are staples, it is determined that the reading target is a closed staple document, and the staple flag is set (# 520, # 521). Then, a staple correction process (# for deleting the image of the staple to improve the appearance) is performed.
522) is executed. If the staple is not detected, it is determined that the reading target is a sheet original and the sheet flag PL is set (# 518). Then, the sheet process (# 518) for the sheet document is executed.

If the original is not in the prescribed shape in step # 512, the height distribution in the main scanning direction is checked (# 51).
3). This is to compensate for the uncertainty of discrimination due to the shape in plan view as described above. When the front side on the document table 20 is low and the rear side (upper side in FIG. 13) is high, it is determined that the document to be read is a spread one-point stop document DS1s, and the one-point stop flag ST1.
s is set (# 514). And the spread 1 described below
The point processing (# 515) and the processing for setting the correction content of the distortion in the main scanning direction (# 516) are executed, and the process proceeds to step # 506 in FIG. If it is determined in step # 513 that the distribution pattern is not the above, it is determined that the reading target is a sheet document (# 517).

FIG. 31 is a flow chart of the original area determination subroutine of FIG. The original area (original surface) of the read image is determined by utilizing the difference in brightness between the original table 20 and the original (# 511A). Then, the degree of inclination of the edge of the document area with respect to the scanning direction is detected, and correction data is calculated (# 511B). Then, the C correction circuit 113
The image data is sent to and the diagonal correction is performed on the read image (# 511C). The one-page spread original document DS1s is more difficult to position than the book original DB and is often inclined. Next, based on the read image after the diagonal correction, FIG.
As described in 0, the width w1 at the position of 5 cm and the width w2 at the position of 10 cm from the lower end of the document area are measured to determine the document size (# 511D, # 511E, # 511).
F). Then, the coordinates corresponding to the corners (upper left corner and upper right corner) of the document area of the determined size, that is, the addresses of the memory 107 are stored (# 511G).

FIG. 32 is a flow chart of the spread two-point processing subroutine of FIG. First, the sub-scanning direction (horizontal)
And the document size in the main scanning direction (vertical) is detected (# 509
A): A standard size closest to the document size is determined based on the aspect ratio (# 509B). Finally, the difference Δw between the specified size and the document size in the sub-scanning direction is obtained to calculate the overlapping width α (= Δw / 2) (# 509C). The overlapping width α is used for image shift by the A correction circuit 111.

FIG. 33 is a flow chart of the spread one-point processing subroutine of FIG. First, the overlapping area Ew is detected in the manner described with reference to FIG. 17 (# 515A), and correction data for the overlapping area Ew is generated (# 515).
B). Then, the height distribution data in the main scanning direction is prepared for post-processing and the process returns (# 515C).

FIG. 34 is a flow chart of the staple correction processing subroutine of FIG. The range of the staple image to be erased is specified from the data obtained by staple detection (# 522A), and the start point address and end point address of the correction area are stored (# 522B).

FIG. 35 is a flow chart of the main scanning subroutine of FIG. Reading target is spread 1
If it is not the stopping document DS1s, the amount of lens movement for focus adjustment is calculated according to the height distribution in the sub-scanning direction, and the imaging lens 32 is moved in accordance with the progress of sub-scanning for photographing to perform focus adjustment ( # 41, # 42, # 43). On the other hand, when the reading target is the one-page spread original DS1s, the lens movement amount is calculated according to the height distribution in the sub-scanning direction and the main scanning direction, and the focus is adjusted in accordance with the progress of the sub-scanning of photographing. Adjustment is performed (# 41, # 44, # 43).

FIG. 36 is a flow chart of the image processing subroutine of FIG. First, based on the correction data calculated in the preliminary scanning stage, the C correction circuit 113 performs diagonal correction on the read image obtained in the main scanning (# 51). Next, the D correction circuit 114 corrects the distortion caused by the curvature of the document surface S1 (# 52).
At that time, the processing time is shortened by correcting the one-page spread original DS1s limited to the curved region A only. After distortion correction, A correction circuit 111 and B correction circuit 1
The background data Dw is output to 12 (# 53), and predetermined processing is performed as follows according to the type of the original.

When the two-point stop flag ST2s is set, in order to shift the image of the two-page spread original DS2s, the address is shifted and the memory 107 is read out as described above, and the A correction circuit is used. The correction parameter (α, d) is given to 111 to instruct the correction (# 54, # 55, # 56). Then, in order to avoid the waste of copying the blank portion, it is determined whether or not there is an image in the left half of the corrected read image (# 57). If the left half is blank, the two-point stop flag ST2s is reset and the process returns. (# 59). As a result, only the right half is printed. If the left half is not blank, the process returns with the two-point stop flag ST2s set.

In step # 54, the two-point stop flag ST2s is set.
Is reset, then staple flag ST
Is checked (# 60). When the staple flag ST is set, the stored position (coordinates) of the staple image is read, image correction for erasing the staple image is executed, and the process returns (# 61, # 62).

If the staple flag ST is in the reset state in step # 60, then the one-point stop flag S
Check T1s (# 63). One-point stop flag ST
If 1 s is set, the spread 1-point stop document D
In order to perform the image shift of S1s, the memory 107 is read out and the correction parameter (a, w) is given to the B correction circuit 112 to instruct the correction (# 64, #).
65).

FIG. 37 is a flow chart of the distortion correction subroutine of FIG. The type of the document is checked by the flag (# 52A), and if it is not the spread one-point stop document DS1s, the scaled data of the read image is calculated based on the height distribution data (DC1) in the sub-scanning direction (# 52F). .
On the other hand, in the case of the one-page spread original document DS1s, the curved area A is obtained based on the height distribution data (DC1) in the sub-scanning direction and the height distribution data (DC2) in the main scanning direction.
(See FIG. 13) is calculated (# 52B). Then, the scaling data in the main scanning direction and the scaling data in the sub-scanning direction with respect to the curved region A are sequentially calculated (# 52C, # 52D).
After setting the variable amount according to the type of original in this way, D
The correction circuit 114 scales each pixel (# 53).
E). Here, as a modified example of the correction, the following method of setting the correction amount may be adopted. When calculating the correction amount of the scaling processing in the main scanning direction and the sub scanning direction, DC1 is set to D
It becomes the function of C2 [DC1 = f (DC2)], and DC2 is DC
It can be imagined that the function of 1 [DC2 = f (DC1)] becomes from the aspect of distortion. Therefore, the correction amount is approximately set to DC1 ′ = DC1 × K2, DC2 ′ = DC2 × K1, and K2 = DC2 / DC2max K1 = DC1 / DC1m
It can be standardized as ax and can satisfy 0 <K1, K2 ≦ 1. That is, when it exceeds 1, it is suppressed to 1. DC
1max and DC2max are the one-page spread document DS1
It is data of the correction amount for the maximum degree of curvature that can occur in s.

FIG. 38 is a flow chart of the data output subroutine of FIG. Whether the data output to the printer 2 is possible or not is checked, and if possible, the data output control of sending the control data and the image data of the memory 107 to the printer 2 is performed (# 71, # 72). If the printer 2 is in the input prohibited state, it waits until it enters the input standby state. The control data here is the paper selection mode (auto / specified size),
Document type (single / double side), copy mode (single / double side)
Both sides), the state of the staple flag ST, and the state of the two-point stop flag ST2s.

39 to 41 show the CPU 10 of the printer 2.
3 is a flowchart of print control executed by No. 2; This routine is executed in interrupt form in response to the data output signal from the book scanner 1.

The CPU 201 receives the control data and the image data from the book scanner 1 and stores them in the memory having the same capacity as the memory 107 (# 201). Then, in order to prevent new data input during printing, data output is temporarily prohibited to the book scanner 1 (# 202).

If the paper selection mode is not auto, the AMS (automatic magnification selection) mode process for setting the output size (print size) according to the paper size specified by the user is executed, and the image data from the book scanner 1 is executed. Create print data of output size based on (# 20
3, # 206, # 207). If the paper selection mode is auto and the staple flag ST is in the reset state,
Set an appropriate paper size according to the original size (# 20
4, # 205) and the process proceeds to step # 207 to create print data.

If the paper selection mode is auto and the staple flag ST is in the set state, the process advances to step 213 in FIG. 40 to set A4 size which is a general paper size as the output size. If the two-point stop flag ST2s is in the reset state, the right half of the read image is set as the print target and the process proceeds to step # 207 (#
214, # 216). Even when the two-point stop flag ST2s is in the set state and the one-sided original is set, the right half is targeted for printing (# 214 to # 216). 2-point stop flag ST
When 2 s is in the set state and is a double-sided original, the copy mode is checked (# 217). For single-sided copying, set the left half of the scanned image as the print target (#
218), and a flag LFT indicating that is set (# 2
19) and proceeds to step # 207. In the case of double-sided copying, the left half is set as the print target (# 220), and the process proceeds to step # 207 without setting the flag LFT.

After the print data corresponding to the image to be printed is created in step # 207 of FIG. 39, the one-sided completion flag related to double-sided copying is checked (# 20).
8). If the one-sided completion flag is in the reset state, the recording paper P of the previously set size is fed (# 209), the print data is output to the print head 203, and the print operation (copy) for driving the print engine 204 is performed. Start (# 210, # 211). If the single-sided completion flag is set, print data is output and copying is started without feeding paper. Then, it waits for the end of copying and proceeds to step # 221 in FIG.

At step # 221, the copy mode is checked. If it is a one-sided copy, the printed recording paper P is discharged (# 222). Flag LFT after paper ejection
Is checked, and if it is in the reset state, printing for one reading is completed. Therefore, the prohibition of data input from the book scanner 1 is released, that is, new data output is permitted for the book scanner 1. Do (# 2
29), exit the interrupt routine. If the flag LFT is in the set state, the flag LFT is reset (# 22
4), the right half of the read image is set as the print target, and the process returns to step # 207 in FIG.

If double-sided copying is selected in step # 221,
Then, the one-sided completion flag is checked (# 226). If the one-sided completion flag is in the reset state, the paper reversing mechanism 2
By driving 50, the recording paper P on which the first side has been printed is set to the standby position for printing the second side (# 227), and the one-sided completion flag is reset (# 228).
Also, the data output permission (# 229) described above is executed, and the interrupt routine is exited. If the one-sided completion flag is set in step # 226, the one-sided completion flag is reset (# 230) and the paper discharge control (# 231) is executed to check the two-point stop flag (# 232). When the two-point stop flag is set, the right half of the read image is set as the print target (# 233), and the process returns to step # 207 in FIG. When the two-point stop flag is reset, the process proceeds to step # 229 described above.

According to the above embodiment, the projection unit 1
8, the image pickup unit 30 is provided with a document surface S1, an end surface S3,
Also, since it is also used for photographing the side surface, it is possible to simplify the configuration and improve the accuracy of height measurement. However, the present invention is not limited to such a configuration. Apart from the image pickup unit 30, an optical system and an image pickup device for picking up images of the end face and the side face may be incorporated. The projection plate 18b for displaying the right side surface of the original is provided because a general document is horizontally written and the left side is often stapled. However, when there are many documents bound on the right side, such as a vertically written document, a projection plate that reflects the left side surface may be provided. If the projection plate 18b showing the side surface can be moved in the left-right direction so as to be in contact with the document, or if the projection plate 18b is used as the reference for the left-right positioning in the same manner as the front-back positioning, the side surface can be photographed more clearly. You can

[0080]

According to the inventions of claim 1 and claim 2 ,
It is possible to reduce the time and effort required to read a specific type of two-page spread original, and to improve the convenience when copying an original consisting of a plurality of bound sheets. Can be easy to use.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a copying system according to the present invention.

FIG. 2 is a perspective view showing an appearance of a book scanner.

FIG. 3 is a schematic diagram of reading with a book scanner.

FIG. 4 is a diagram showing a state in which a two-page spread single-point stop document is set.

FIG. 5 is a configuration diagram of a sub-scanning mechanism.

FIG. 6 is a configuration diagram of an AF mechanism.

FIG. 7 is a diagram showing an example of a display form of document types.

FIG. 8 is a diagram showing a region of interest in determining the presence or absence of staples.

FIG. 9 is a diagram showing height distributions of three types of spread originals.

FIG. 10 is a diagram for explaining a method of discriminating a document type based on a planar view shape.

FIG. 11 is a perspective view showing an example of a two-page spread one-point stop document.

FIG. 12 is a diagram for explaining a method of measuring the height distribution of the document surface.

FIG. 13 is a diagram showing a correction target area in a double-page spread single-point stop original.

FIG. 14 is a schematic diagram of a height distribution in the main scanning direction in a two-page spread original document.

FIG. 15 is a diagram showing an example of a height setting method in focus adjustment.

FIG. 16 is a diagram for explaining another example of focus adjustment.

FIG. 17 is a diagram showing a method of detecting an overlapping area.

FIG. 18 is a functional block diagram of a copying system.

FIG. 19 is a schematic diagram of a function of an A correction circuit.

FIG. 20 is a block diagram of an A correction circuit.

FIG. 21 is a schematic diagram of the function of the B correction circuit.

FIG. 22 is a block diagram of a B correction circuit.

FIG. 23 is a diagram showing copying forms of three types of staple originals.

FIG. 24 is a flowchart of a main process executed by the CPU of the book scanner.

FIG. 25 is a flowchart of a copy mode switching process subroutine of FIG. 24.

26 is a flowchart of a staple processing subroutine of FIG.

27 is a schematic flowchart of the read control subroutine of FIG. 24. FIG.

FIG. 28 is a schematic flowchart of a document detection subroutine of FIG. 27.

FIG. 29 is a flowchart of a document type determination subroutine in FIG. 28.

FIG. 30 is a flowchart of a document type determination subroutine in FIG. 28.

31 is a flowchart of a document area determination subroutine of FIG. 30. FIG.

32 is a flowchart of a two-page spread two-point processing subroutine of FIG. 29. FIG.

33 is a flowchart of a one-point spread processing subroutine of FIG. 30. FIG.

34 is a flowchart of a staple correction process subroutine of FIG.

FIG. 35 is a flowchart of a main scanning subroutine of FIG. 27.

FIG. 36 is a flowchart of the image processing subroutine of FIG. 27.

FIG. 37 is a flowchart of the distortion correction subroutine of FIG.

FIG. 38 is a flowchart of the data output subroutine of FIG. 27.

FIG. 39 is a flowchart of print control executed by the CPU of the printer.

FIG. 40 is a flowchart of print control executed by the CPU of the printer.

FIG. 41 is a flowchart of print control executed by the CPU of the printer.

[Explanation of symbols]

1 Book scanner (image reading device) 20 Platen 30 Imaging unit (imaging system) 80 space (open space) 101 CPU DS2s Two-page spread double-sided original (two-page spread original) OS optical system st staple

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenichi Morita, Kenichi Morita 2-3-13 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka, Osaka International Building Minolta Co., Ltd. (72) Shin Shin Fu, Azuchi, Chuo-ku, Osaka-shi, Osaka 2-13-3 Machi, Osaka International Building, Minolta Co., Ltd. (56) Reference JP-A-8-37584 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/10 G03B 27/80 H04N 1/04 106 H04N 1/107 H04N 1/393

Claims (2)

(57) [Claims] 1. A manuscript table for supporting a manuscript, an imaging system for converting a manuscript image into an electric signal, and an optical system for projecting a manuscript image on an imaging surface of the imaging system. An image reading device having a structure in which an open space for setting a document exists between the document and the system, the height of the document surface of the document placed on the document table in the spread direction.
A measuring means for measuring the distribution and a paper of a prescribed size placed on the platen in a spread manner.
Calculate the creepage distance of the double- page spread original in the double-page spread direction based on the height distribution of the original surface of the original.
Means, stipulation of detected creepage distance and width closest to the creepage distance
By comparing the corresponding width of the paper size, before Symbol viewed <br/> open document, and means for determining whether a small spread document than twice the size when spread size is not wide open, the as the output size of the spread document read image, if it is determined that the smaller spread document than twice the size when spread size is not wide open, closest to the bisecting size in a direction facing the spread size of the Book original An image reading apparatus comprising means for automatically setting a specified size, or a specified size that is closest to the spread size otherwise. 2. A manuscript table for supporting a manuscript, an imaging system for converting a manuscript image into an electric signal, and an optical system for projecting a manuscript image on an imaging surface of the imaging system. An image reading apparatus having a structure in which an open space for setting a document is present between the system and the system, and the height of the document surface of the document placed on the document table in the spread direction.
A measuring unit for measuring the distribution; a unit for determining whether the document is a spread document or not based on the curved state of the document surface of the document placed on the platen obtained by the height distribution; the document is judged whether the staple document that has been stapled by extracting staples image from read - image of a document placed on a table, the document is
Set a flag to show if the original is staple
And the output size of the read image of the original placed on the original table.
And then open it while the flag is set.
If it is determined that the document is a manuscript, a means for automatically setting the specified size that is the closest to the spread size of the document, and the specified size that is the closest to the spread size if it is not An image reading device characterized by having.