JP2002247308A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader which can read out even a deformed document, e.g. a book document, appropriately. SOLUTION: In the image reader 1, at least the top or bottom end of a book document 4 set on a contact glass 3 while being opened is irradiated with light from a light source, light reflected from the top or bottom end of the book document 4 is reflected on a reflector 5 in the direction of a lens 7 and condensed through a lens 6 to an image pickup element 7 where the incident light is subjected to photoelectric conversion, thus detecting the shape at the top or bottom end of the book document 4. The image reader 1 moves the optical system or the image pickup element at the read out section or a SELFOC (R) lens in the direction of the optical axis based on the detected shape of the book document 4, and adjusts pint depending on the distance between the book document 4 and the contact glass 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image reading apparatus, and more particularly, to an image reading apparatus that appropriately reads a deformed original such as a book original.

[0002]

2. Description of the Related Art A flat bed type image reading device is generally used as an image reading device such as a facsimile device or a scanner device. In such an image reading device, a single horizontally arranged flat plate is used. The document is set on the contact glass so that the image surface of the document is pressed, and the image of the document is read by a scanning optical system that reciprocates in the sub-scanning direction along the lower surface of the contact glass.

This scanning optical system generally includes a first light source and a first light source which reflect light reflected from a document below a contact glass.
A first traveling body equipped with a mirror, a second traveling body equipped with a second mirror and a third mirror, a lens, and a photoelectric conversion element such as a CCD. While moving in the sub-scanning direction at a speed, the original on the contact glass is irradiated with reading light from the light source on the first traveling body, and the reflected light from the original is reflected by the first mirror on the second mirror on the second traveling body. To reflect. The reflected light is reflected in the direction of the third mirror by the second mirror, the reflected light is reflected in the direction of the lens by the third mirror, and the reflected light is focused on the photoelectric conversion element by the lens.
The image of the document is read by performing photoelectric conversion by the photoelectric conversion element.

However, since the contact glass provided in the image reading apparatus is a flat glass plate, when a sheet-like document is set on the contact glass, the document easily comes into close contact with the contact glass surface. For,
Although a clear read image can be obtained, if the original is book-shaped such as a book and there is a binding portion in the center of the double-page spread, the binding stitches will rise, and the entire reading surface of the original will be in contact. Reading is performed in a state where the glass does not adhere to the glass.

[0005] For this reason, there arises a problem that a read image of a portion which does not adhere to the upper surface of the contact glass becomes unclear, reduced, or darkened. Also, when a book or the like is widely opened to a horizontal state, the spine portion is greatly bent, causing a fold on the hard spine, separating the spine from the back side of the binding, or binding the binding. There is a problem in that the stitched portion, such as being separated and damaged, is adversely affected.

Therefore, conventionally, in an image reading apparatus that has a scanner that moves along the lower surface of a platen and reads an image of a document set on the platen, the end face of the platen is positioned to the side of the apparatus, An image reading apparatus (see Japanese Patent Application Laid-Open No. 2000-165617) for setting and binding a book document to an edge formed by the end of the book and the surface on the apparatus side, and a flat plate for setting the document In an image reading apparatus provided with a platen shaped like a letter and a scanner that moves along the lower surface of the platen, a platen arranged horizontally and a platen arranged inclined at a predetermined angle are connected via an edge portion. An image reading device that sets the binding portion of the book document so as to be positioned at the edge portion and reads both spread pages of the book document. (See JP 2000-165608) it has been proposed.

In other words, these image reading apparatuses improve the adhesion of the binding portion of the book document,
Trying to solve the above problem.

[0008]

However, such a conventional image reading apparatus is not suitable for reading an ordinary sheet-shaped document, and needs to be improved.

Therefore, according to the first aspect of the present invention, the original on the contact glass is moved while the reading means is moved in the sub-scanning direction, and the reading means irradiates the original with reading light and receives reflected light from the original. When reading the image of the document by main scanning, the distance between the document and the contact glass on the contact glass is detected by the distance measuring means, and based on the detection result,
By correcting the distortion of the read image of the original read by the reading means, even if there is a part separated from the original and the contact glass, such as a binding part of a book original on the contact glass, the image distortion of the separated part is obtained. It is an object of the present invention to provide an image reading apparatus which can appropriately correct the image quality and read a deformed original such as a book original with high quality.

According to a second aspect of the present invention, an original such as a binding portion of a book original on a contact glass is adjusted by adjusting the focus of the reading means when reading the original based on the detection result of the distance measuring means. Even if there is a part where the contact glass is separated from the contact glass, it is necessary to properly adjust the focus of the separated part to prevent the read image from being blurred and to read a deformed document such as a book document with higher quality. It is an object of the present invention to provide an image reading apparatus capable of performing the above.

According to a third aspect of the present invention, the light amount of the reading light of the reading means at the time of reading the document is adjusted based on the detection result of the distance measuring means, so that the binding portion of the book document on the contact glass or the like is adjusted. Even if there is a part separated from the contact glass as described above, appropriately adjust the amount of light to the separated part to prevent darkening, and to read even a deformed document such as a book document with higher quality. It is an object of the present invention to provide an image reading apparatus capable of performing the following.

According to a fourth aspect of the present invention, a book document on a contact glass is bound by changing the moving speed of the reading device in the sub-scanning direction when reading the document based on the detection result of the distance measuring device. Even if there is a part such as a part that is separated from the original and the contact glass, the moving speed in the sub-scanning direction at the separated part is reduced to prevent the separated part from being reduced and imaged. It is another object of the present invention to provide an image reading apparatus capable of reading a deformed document such as a book document with higher quality.

According to a fifth aspect of the present invention, based on the detection result of the distance measuring unit, the binding direction of the original with respect to the main scanning direction of the reading unit is set such that the variation in the distance between the original surface of the original and the contact glass is reduced. By changing the relative position of the reading means and the original with the moving means for relatively changing
An image reading apparatus capable of reading a document having a large variation in the distance between the contact glass and the document in the main scanning direction while keeping the variation small, and capable of reading a highly deformed document with higher quality. It is intended to provide.

According to a sixth aspect of the present invention, when reading a document by moving the reading means in multiple steps in the sub-scanning direction, the sub-scanning of each stage is performed based on the detection result of the distance measuring means.
The main scanning is performed by changing the focal position of the reading unit to a plurality of positions, and an image in one main scanning direction is created from the images read in the plurality of main scannings. For documents with large variations,
It is an object of the present invention to provide an image reading apparatus that reads a document with the variation being small and that can read a document with large deformation with higher quality.

[0015]

According to a first aspect of the present invention, there is provided an image reading apparatus, comprising: irradiating a reading light on a document on a contact glass while moving the reading device in a sub-scanning direction; In an image reading apparatus that receives reflected light from the main scanning of the original and reads the image of the original by scanning the original, the distance between the original and the contact glass on the contact glass is detected by a distance measuring unit, and the detection result is On the basis of,
The object is achieved by correcting the distortion of the read image of the document read by the reading unit.

According to the above arrangement, while the reading means is moved in the sub-scanning direction on the original on the contact glass, the reading means irradiates the reading light and receives the reflected light from the original to perform main scanning on the original. When reading the image of the original, the distance between the original and the contact glass on the contact glass is detected by the distance measuring unit, and based on the detection result, the distortion of the read image of the original read by the reading unit is corrected. Even if there is a part separated from the original and the contact glass, such as a binding part of a book original on the contact glass, it is possible to appropriately correct the distortion of the image of the separated part, and to deform a deformed original such as a book original. Can also be read with high quality.

In this case, for example, the image reading apparatus adjusts the focus of the reading means when reading the original based on the detection result of the distance measuring means. There may be.

According to the above arrangement, the focus of the reading means when reading the original is adjusted based on the detection result of the distance measuring means. Even if there are parts that are separated from each other, it is possible to appropriately adjust the focus of the separated parts to prevent the read image from being blurred, and to read a deformed original such as a book original with higher quality. it can.

In addition, for example, the image reading device adjusts the amount of light of the reading light of the reading means when reading the document based on the detection result of the distance measuring means. It may be something.

According to the above arrangement, the light amount of the reading light of the reading means when reading the original is adjusted based on the detection result of the distance measuring means. Even if there is a part that separates from the glass, it is possible to appropriately adjust the amount of light to the part that is separated from the glass to prevent darkening, and to read a deformed original such as a book original with even higher quality. Can be.

Further, for example, as set forth in claim 4, the image reading device moves the reading means in the sub-scanning direction when reading the document based on the detection result of the distance measuring means. May be changed.

According to the above arrangement, the moving speed of the reading means in the sub-scanning direction when reading the original is changed on the basis of the detection result of the distance measuring means. Thus, even if there is a part separated from the document and the contact glass, the moving speed in the sub-scanning direction at the separated part can be reduced to prevent the separated part from being reduced and imaged. Also, a deformed original such as a book original can be read with higher quality.

For example, as set forth in claim 5, the image reading apparatus further includes a moving means for relatively changing a binding direction of the original with respect to a main scanning direction of the reading means, Based on the detection result of the means,
The relative position between the reading unit and the original may be changed by the moving unit in a direction in which the variation in the distance between the original surface of the original and the contact glass is reduced.

According to the above arrangement, the binding direction of the document with respect to the main scanning direction of the reading means is relatively set in the direction in which the variation in the distance between the document surface and the contact glass is reduced based on the detection result of the distance measuring means. Since the relative position between the reading means and the document is changed by the moving means for changing the size of the document, the document is read with a large variation in the distance between the contact glass and the document in the main scanning direction while keeping the variation small. Thus, an original with large deformation can be read with higher quality.

Further, for example, when reading the document by moving the reading means in the sub-scanning direction in multiple steps,
In the sub-scanning of each stage, based on the detection result of the distance measuring unit,
The main scanning may be performed by changing the focal position of the reading unit to a plurality, and an image in one main scanning direction may be created from the images read by the plurality of main scannings.

According to the above arrangement, when the reading means is moved in the sub-scanning direction in multiple steps to read the original, the reading means based on the detection result of the distance measuring means in each sub-scanning operation. The main scanning is performed by changing the focal position to a plurality of positions, and an image in one main scanning direction is created from the images read by the plurality of main scannings. Therefore, the distance between the contact glass and the document in the main scanning direction varies. For a large document, the document can be read with the variation being small,
An original with large deformation can be read with higher quality.

[0027]

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

Although the embodiments described below are preferred specific examples of the present invention, various technically preferable limitations are given. However, the scope of the present invention is not limited to the following description. The present invention is not limited to these embodiments unless stated to limit the invention.

FIGS. 1 to 14 show a first embodiment of the image reading apparatus of the present invention. FIG. 1 shows an image to which the first embodiment of the image reading apparatus of the present invention is applied. FIG. 2 is a side view of the image reading device 1 of FIG. 1.

The image reading apparatus 1 has a contact glass 3 provided on an upper surface of a main body 2, and is set on the contact glass 3 (not shown) in the main body 2 below the contact glass 3. And a reading unit for reading an image of the scanned document. The reading unit (reading unit) includes, for example, a first traveling body equipped with a light source and a first mirror that reflects light reflected from a document, a second traveling body equipped with a second mirror and a third mirror, a lens, and a CCD. And the like. The reading unit emits reading light from a light source on the first traveling body to a document on the contact glass while moving the first traveling body and the second traveling body in the sub-scanning direction at a predetermined moving speed, respectively. Is reflected by the first mirror to the second mirror on the second traveling body, the second mirror reflects the reflected light toward the third mirror, and the third mirror reflects the reflected light toward the lens. Then, the image of the original is read by condensing the reflected light on the photoelectric conversion element by the lens and performing photoelectric conversion by the photoelectric conversion element.

The contact glass 3 in the main body 2
The book original 4 set on the contact glass 3 is irradiated from a light source disposed below the book original 4, and the light reflected on the contact glass 3 by the book original 4 in a substantially horizontal direction is reflected toward the main body housing 2. The reflecting mirror 5 is provided on the upper part of the main body housing 2.

An image pickup device 6 to which light reflected by the reflecting mirror 5 is irradiated and a lens 7 for condensing light reflected by the reflecting mirror 5 to the image pickup device 6 are provided in the main body housing 2. The light source, the reflecting mirror 5, the image sensor 6, and the lens 7 are provided.
Constitutes a document shape detecting section (distance measuring means) 8 as a whole.

The original shape detecting section 8 includes the contact glass 3
Light is emitted from a light source to the top or bottom edge of the book document 4 set to be opened above, and the light reflected at the top or bottom edge of the book document 4 is reflected by a reflecting mirror 5 into a lens 7. The light is reflected in the direction, and the incident light is
Then, the incident light is photoelectrically converted by the image sensor 7 to detect the shape of the point of the book document 4 or the end of the ground, particularly, the distance between the contact glass 3 and the book document 4.

As the light source, a light source of a reading section for reading an image of a document may be used. In this case, when the shape of the book document 4 is detected, the lens 6 and the image pickup device 7 are read together in the main scanning direction. It may be made to move together with the original of the copy.

Next, the operation of the present embodiment will be described. Usually, as shown in FIG. 3, when reading the image of the book document 4 set on the contact glass 3 of the image reading device 1, the vicinity of the binding portion floats from the contact glass 3. As described above, the shape of the read image in the vicinity of the binding portion is distorted, the focus is blurred, or the illumination light from the light source is insufficient. Deteriorates.

When such a book document 4 is set on the contact glass 3, the surface of the book document 4 facing the contact glass 3 can be regarded as a set of straight lines as shown in FIG. When the shape of one portion of the book document 4 is measured in the direction of the arrow shown in FIG.
Can be detected.

Therefore, the image reading apparatus 1 of the present embodiment
Irradiates light from a light source to at least the top or bottom edge of the book document 4 opened and set on the contact glass 3, and reflects the light reflected at the top or bottom edge of the book document 4 The light is reflected by the reflecting mirror 5 in the direction of the lens 7, the incident light is condensed on the image sensor 7 by the lens 6, the incident light is photoelectrically converted by the image sensor 7, and the point of the book document 4 or the edge of the ground is The shape of the part is detected.

Then, based on the shape of the book document 4 detected in this way, the image reading apparatus 1 moves the optical system of the reading section, the image pickup device, the cell hook lens and the like in the optical axis direction, and The focus is adjusted according to the distance between the contact glass 4 and the contact glass 3.

Further, the image reading apparatus 1 detects the shape of the book document 4 by the document shape detecting section 8 before taking in the book document 4, and moves the reading position in the sub-scanning direction. Each time, adjust so that the part that is reading is in focus.

As shown in FIG. 3 and FIG. 6, the central portion of the book
, The light amount of the light source is insufficient, and the image to be read is darkened.

Therefore, the image reading device 1 adjusts the illuminance of the light source of the reading unit according to the detection result of the document shape detecting unit 8. That is, the image reading apparatus 1 measures the distance of the document surface of the book document 4 before reading the book document 4 and irradiates the book document 4 from the document of the reading unit when the book document 4 is read by the reading unit. Adjust the intensity of the light.
That is, the image reading apparatus 1 irradiates stronger light as the distance from the contact glass 3 to the document surface of the book document 4 increases.

Further, in the image reading apparatus 1, when the whole surface of the document is in close contact with the contact glass 3, there is no distortion in the read image, but in the case of the book document 4, the image is floating from the contact glass 3. Since there is a portion and a binding portion, the read image is distorted according to the floating amount.

Therefore, the image reading device 1 corrects the distortion of the read image based on the detection result of the document shape detecting section 8. The image reading apparatus 1 corrects the distortion of the read image in accordance with the distance between the contact glass 3 and the document surface of the book document 4 and the inclination of the document surface. Detecting the shape of the document surface of the book document 4 is more accurate than detecting the distortion by analyzing the image, so that more accurate distortion correction can be performed.

Also, in the case of the book document 4, the portion floating from the contact glass 3 near the binding portion is smaller than the portion in close contact with the contact glass 3 even when characters of the same size are read. It is.

Then, the image reading apparatus 1
Is read, a correction process for adjusting the size of the image read on each side of the book document 4 is performed. However, as shown in FIG. 7, since the image information for one character is originally small, the character size is adjusted. However, not only does each character not become clear, but if the characters are crushed as shown in FIG. 8, correction by interpolation processing cannot be performed.

To increase the information amount of the portion floating from the contact glass 3 detected by the document shape detecting section 8, the image reading device 1 adjusts the amount of floating or the inclination of the document surface of the book document 4. Adjust the sub-scanning capture interval. In other words, as the distance between the document surface and the contact lens 3 increases, the feed pitch is reduced, and the amount of information to be taken in the shape of the book document 4 is increased.

Further, when reading a flat original (sheet-shaped original), it is not particularly necessary to measure the original shape, that is, the distance between the contact glass 3 and the original surface. Reading may be delayed.

Therefore, the image reading apparatus 1 is provided with a detection switch for the user to select whether or not to operate the document shape detection unit 8 depending on the form of the document, or as shown in FIG. The angle of the document holding plate 9 for bringing the document into close contact with the contact glass 3 is detected, and a document reading instruction, for example, only when a start key of the operation unit is turned on at a predetermined angle or more, is set. Is determined to be a book document 4, and the document shape detection unit 8 is operated. In order to detect the angle of the document holding plate 9, for example, a detection switch is provided near the hinge of the document holding plate 9, and the document holding plate 9 is provided.
Is tilted in the direction of the contact glass 3 from the predetermined angle, the detection switch is turned on to detect that a sheet document other than the book document 4 is set on the contact glass 3.

The book document 4 is not in the direction in which the binding direction of the book document 4 coincides with the main scanning direction indicated by the arrow in FIG. 10, but in the state in which the binding direction coincides with the sub-scanning direction as shown in FIG. When the document is set on the contact glass 3, it is impossible to focus on the blur of the image near the binding of the book document 4.

Therefore, if the length of the image reading device 1 that is not in close contact with the contact glass 3 is larger than a predetermined ratio as a result of the detection by the document shape detecting section 8, the image reading device 1 can read the image under good conditions. The user of the image reading apparatus 1 is notified that the operation cannot be performed. For example, this notification is performed by displaying the fact on a display of the operation unit, generating a predetermined warning sound, or outputting a voice message to that effect.

Further, in this case, instead of notifying that the image reading cannot be performed under good conditions, the image reading apparatus 1 uses, for example, the book document 4 set on the contact glass 3 and the main scanning direction by the reading unit. May be relatively moved so that the binding direction of the book document 4 matches the main scanning direction of the reading unit.

That is, for example, as shown in FIGS. 11 and 12, at least one of the contact glass 3 and the reading section 10 of the image reading apparatus 1 is relatively movable, and as shown in FIG. When the unit 10 is set on the contact glass 3 in a state where the main scanning direction and the binding direction of the book document 4 are orthogonal to each other, the contact glass 3
And the reading unit 10 are relatively moved so that the main scanning direction of the reading unit 10 and the binding direction of the book document 4 match as shown in FIG. By doing so, it is possible to appropriately focus on the binding portion of the book document 4 according to the detection result of the document shape detection unit 8 and read the image of the book document 4 in a good state. Can be.

When the focal position of the book document 4 changes, for example, as shown in FIG. 13 in the main scanning direction as the focal positions a to c, the focal position is changed and a plurality of images are changed. Take and place, as shown in FIG.
By combining the in-focus images for each part, an in-focus image can be created as a whole even if the distance from the document surface is different in the main scanning direction.

Further, in this case, instead of taking in an image while changing the focal position in one sub-scan, in one sub-scan, the image of the entire surface is taken in while the focal position is fixed, and the focal position is changed again. Change to capture the entire image. For example, in the case of FIG. 13, the entirety is read once with the focus position set at a, then the whole is read with the position b, and then the whole is read with c. Thereafter, by discarding the data of the out-of-focus portion and combining the in-focus portions, it is possible to obtain an entire in-focus image. In this case, the feed speed in the sub-scanning direction is kept constant and does not stop, so that the uneven surface of the document can be read quickly.

Further, when reading the book document 4, if the document shape detection unit 8 detects the shape each time, it takes time. Therefore, when reading the same book document 4 over several pages, turning the book document 4 by several pages does not change the shape of the document surface as much as reading is affected. In this case, once the document shape detection unit 8 performs shape detection, it is assumed that the detection information applies to all of the pages to be read, and the shape detection may not be performed until the document is read a predetermined number of times. .

FIGS. 15 and 16 are diagrams showing a second embodiment of the image reading apparatus of the present invention.
FIG. 6 is a perspective view of a document shape detection unit 20 of the image reading apparatus to which the second embodiment of the image reading apparatus of the present invention is applied.

In FIG. 15, the original shape detecting unit 20
A plurality of contacts 21 are attached to the attachment plate 22,
Each contact 21 is provided in the inner direction of the mounting plate 22 and the mounting plate 22.
Is mounted on the mounting plate 22 so as to be movable in a direction protruding from the mounting plate 22.

When the contact 21 is pressed against the top or bottom edge of the book document placed on the contact glass, the document shape detecting section 20 as shown in FIG. A step is generated where the contact 21 is pushed at the end of the ground and where the contact 21 is not pushed, and the shape of the book document can be detected with this step shape.

FIGS. 17 and 18 are schematic structural diagrams of a document shape detecting section 30 of an image reading apparatus to which the third embodiment of the image reading apparatus of the present invention is applied.

The document shape detecting unit 30 of the image reading apparatus according to the present embodiment uses a distance measuring method for auto-focusing of a camera as a method for obtaining the distance between the contact glass and the surface of the document 31. As shown in FIG. 17, an infrared light emitting section 32 and an infrared light receiving section 33 are provided. The infrared light emitting unit 32 includes an infrared LED (Light Emitting Diode) 3
4 and a light projecting lens 35, and the infrared light receiving unit 33 includes a light receiving lens 36 and a light receiving element 37. The light receiving element 37 may be a PSD (Position Sensitive Diode).

The original shape detecting section 30 includes an infrared LED 33
Irradiates the infrared light toward the original 31 through the light projecting lens 35 and irradiates the infrared light reflected by the original 31 to the light receiving element 37 through the light receiving lens 36, and detects the shape of the original by detecting where the light is incident on the light receiving element 37. The distance L between the section 30 and the surface of the document 31 whose distance is to be measured can be found from the following equation (1).

L = (D · f) / b (1) where D is the distance between the centers of the light projecting lens 35 and the light receiving lens 36, f is the focal length of the light receiving lens 36, and b is the light receiving The distance from the center of the element 37 to the incident position.

Actually, as shown in FIG. 18, since light is projected and received through the contact glass 38, it is necessary to consider a shift due to refraction at the contact glass 38. When the contact glass 38 is formed with an anti-reflection film so that infrared rays are not reflected, detection accuracy can be improved.

As the document shape detecting section, a passive type may be used. In that case, pattern light is projected so that distance measurement can be performed correctly even in a place where there is no character or pattern.

Further, when the original shape detecting section is moved together with the movement of the reading section for reading the image of the original for sub-scanning, the actuator of the original shape detecting section can use the moving mechanism of the reading section. And there is no need to have it separately.

The original shape detecting section 30 is not limited to the one using infrared rays. Unlike a camera or the like, even if it is visible light, the light receiving section 33 of the original shape detecting section 30 can be illuminated with an original. If the wraparound of the working light is below the allowable amount, it can be used. Therefore, a part of the light amount of the image reading illumination light is projected on the surface of the
May be used to detect the position of the surface. In addition, the passive type document shape detection unit emits a reference pattern
A part of the light amount may be guided from the illumination light source. As a method of guiding the illumination light for image reading for distance measurement,
A reflector or a light guide can be used.

FIG. 19 shows a document shape detecting section 4 of an image reading apparatus to which the fourth embodiment of the image reading apparatus of the present invention is applied.
0 is a schematic configuration diagram.

In FIG. 19, a document shape detecting section 40 of the image reading apparatus according to the present embodiment is integrally attached to a reading section 41 for reading an image of a document. A line sensor 43 is provided.

The document shape detecting section 40 has a light projecting section 44 and a light receiving section 45, and the light projecting section 44 and the light receiving section 45 are arranged in the reading section 41 side by side in the main scanning direction.

By arranging the light projecting unit 44 and the light receiving unit 45 in this way, a large space is not required and the base line length can be increased, so that the accuracy of distance measurement can be improved. When the light projecting unit 44 and the light receiving unit 45 are arranged in the main scanning direction, as shown in FIG.
When the light receiving unit 45 cannot receive the light emitted from the light projecting unit 44 and reflected by the original 46 due to the original 46, as in the case where the light source 5a is disposed in the sub-scanning direction, It is possible to reduce the possibility of being unable to reach the distance.

FIG. 21 shows a case where a plurality of distance measuring points are provided in the main scanning direction in the document shape detecting section 40 and the distance is measured in conjunction with the movement of the reading section 40 in the sub-scanning direction. As described above, even when the book document 47 is set in a state where the binding direction of the book document 47 matches the main scanning direction of the reading unit 41 on the contact glass 48, the shape detection (distance measurement) of the book document 47 is performed. It can be performed.

FIGS. 22 to 25 are views showing a fifth embodiment of the image reading apparatus of the present invention. FIG. FIG. 3 is a perspective view illustrating a state where a pattern light 51 is projected on a document 50.

In FIG. 22, the pattern light 51 has a different projection direction from the light receiving direction of the pattern light 51, and the original shape detector detects the position and shape of the entire surface of the original 50 based on the principle of the light cutting method. Can be detected.

The original shape detecting section moves the pattern light 51 to project a point image on the surface of the original 50 as shown in FIGS. Good. In this way, the detection of the shape of the surface of the document 50 and the reading of the image can be performed by one reading unit, and although it takes time, the number of parts can be reduced. In this case, if the color of the projected pattern light 51 and the color of the surface of the document 50 are the same, the position of the surface of the document 50 may not be known. Prepare the original 50
Can be detected.

Further, when the pattern light 51 is projected, there is a possibility that a pattern in which the pattern light 51 is blurred on the document surface may appear as shown in FIG.

In this case, if the pattern light 51 has a large pitch and a limited number of patterns, the undulation of the document surface is limited to some extent, so it is possible to know from where the pattern light 51 emitted is emitted. . However, if the pitch of the pattern light 51 to be projected is narrowed as shown in FIGS. 24 and 25 in order to increase the document shape detection accuracy, it is not possible to specify where the pattern is projected from. Can not be performed.

Therefore, when a plurality of colors are used as the pattern light 51 and the colors are sequentially changed, it is possible to specify which pattern is blurred on the document surface.

When the image reading apparatus has a reading section for reading a color original, the light receiving section of the original shape detecting section and the reading section for reading the image of the original also serve to solve the problem relating to the detection of a plurality of colors. Can be.

Although the invention made by the inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above embodiments, and various modifications may be made without departing from the gist of the invention. Needless to say, it can be changed.

[0080]

According to the image reading apparatus of the first aspect of the present invention, the reading light is irradiated from the reading means to the original on the contact glass while the reading means is moved in the sub-scanning direction, and the original is reflected from the original. When reading the image of the original by receiving light and scanning the original, the distance of the original on the contact glass from the contact glass is detected by the distance measuring unit, and the original read by the reading unit is detected based on the detection result. Therefore, even if there is a part separated from the original and the contact glass, such as a binding part of a book original on the contact glass, the image distortion of the separated part can be appropriately corrected. Thus, a deformed document such as a book document can be read with high quality.

According to the image reading apparatus of the present invention, the focus of the reading means when reading the original is adjusted based on the detection result of the distance measuring means. Even if there is a part where the document and the contact glass are separated, as in the case of, the read image can be prevented from being blurred by appropriately adjusting the focus of the separated part, and even a deformed document such as a book document can be used. It can read with even higher quality.

According to the image reading apparatus of the present invention, since the light amount of the reading light of the reading means when reading the original is adjusted based on the detection result of the distance measuring means, the book original on the contact glass is adjusted. Even if there is a part that separates from the contact glass such as a binding part, it is possible to appropriately adjust the amount of light to the distant part to prevent darkening, and to deform a deformed original such as a book original. Can be read with even higher quality.

According to the image reading apparatus of the present invention, the moving speed of the reading means in the sub-scanning direction when reading the original is changed based on the detection result of the distance measuring means. Even if there is a part that separates the original from the contact glass, such as the binding part of the book original,
By slowing the moving speed in the sub-scanning direction at the distant portion, it is possible to prevent the distant portion from being reduced in size and being imaged, so that even a deformed document such as a book document can have higher quality. Can be read by

According to the image reading apparatus of the present invention, the main scanning of the reading means is performed in the direction in which the variation in the distance between the document surface of the document and the contact glass is reduced based on the detection result of the distance measuring means. Since the relative position between the reading means and the original is changed by the moving unit that relatively changes the binding direction of the original with respect to the original direction, the variation in the distance between the contact glass and the original in the main scanning direction is large. The original can be read in a small state, and an original with large deformation can be read with higher quality.

According to the image reading apparatus of the sixth aspect, when reading the original by moving the reading means in multiple steps in the sub-scanning direction, the sub-scanning of each stage is performed by the distance measuring means. On the basis of the detection result, the focal position of the reading unit is changed to a plurality of positions and the main scanning is performed, and one image in the main scanning direction is created from the images read by the plurality of main scannings. A document having a large variation in the distance between the document and the document can be read with the variation being small, and a document having a large deformation can be read with higher quality.

[Brief description of the drawings]

FIG. 1 is an upper perspective view of an image reading apparatus to which a first embodiment of the image reading apparatus of the present invention is applied.

FIG. 2 is a side view of the image reading apparatus of FIG.

FIG. 3 is a front view of a state in which a book original is placed on a contact glass of the image reading apparatus of FIG. 1;

FIG. 4 is a view showing an example of a read image when the book document of FIG. 3 is read by a conventional image reading apparatus.

FIG. 5 is a schematic diagram in which the surface of the book document of FIG. 3 facing the contact glass is regarded as a set of straight lines.

FIG. 6 is a diagram showing a book document on a contact glass and a scanning direction of the image reading apparatus of FIG. 1;

FIG. 7 is a diagram illustrating an example of a state in which characters in a bound portion of the book document in FIG. 3 are read, and a simple enlargement correction process is performed to deteriorate the character quality.

FIG. 8 is a diagram showing an example of a state in which characters in a bound portion of the book document in FIG. 3 are read, a simple enlargement correction process is performed, and characters are crushed.

FIG. 9 is a top perspective view of the image reading device in the case where the operation of the document shape detection unit is controlled on / off by the angle of the document pressing plate in the image reading device of FIG. 1;

10 is a top perspective view of a state in which a book document is set on the contact glass of the image reading apparatus of FIG. 1 in a state where the binding direction matches the sub-scanning direction.

11 is a top view of the image reading apparatus in a state in which a book original is set on the contact glass in which the reading unit is relatively movable with respect to the contact glass of the image reading apparatus in FIG. Perspective view.

12 is a top perspective view of the image reading apparatus in a state where the contact glass and the reading unit of FIG. 11 are relatively moved to make the binding direction of the book document coincide with the main scanning direction.

FIG. 13 is a diagram illustrating a state in which the focal position of a book document changes in the main scanning direction.

FIG. 14 is a schematic diagram illustrating a state in which the focus positions of the book originals in the state of FIG. 13 are detected and connected by an original shape detection unit;

FIG. 15 is a perspective view of a document shape detecting unit of the image reading apparatus to which the second embodiment of the image reading apparatus according to the invention is applied.

FIG. 16 is a perspective view showing a state where the shape of a book document is detected by the document shape detection unit in FIG. 15;

FIG. 17 is a schematic configuration diagram of a document shape detection unit of an image reading device to which a third embodiment of the image reading device of the present invention is applied.

18 is an explanatory diagram of a refraction state of detection light on a contact glass of the document shape detection unit in FIG.

FIG. 19 is a perspective view of a document shape detection unit of an image reading apparatus to which a fourth embodiment of the image reading apparatus of the present invention is applied.

20 is an explanatory diagram of a state in which the light projecting unit and the light receiving unit of the document shape detection unit in FIG. 19 are arranged in the main scanning direction and light is kicked by the document.

FIG. 21 is a perspective view of a state in which a book document is placed on a contact glass of the image forming apparatus to which the document shape detection unit of FIG. 19 is applied in a state where a binding direction matches a main scanning direction.

FIG. 22 is a perspective view of a state in which pattern light is emitted from a document shape detection unit of an image reading apparatus to which a fifth embodiment of the image reading apparatus of the present invention is applied to a book document.

FIG. 23 is a schematic diagram showing a state in which the pattern light shown in FIG. 22 is moved and projected on a book document in conjunction with sub-scanning of document reading.

FIG. 24 is a perspective view showing a state in which the pattern light of FIG. 22 is applied to a book document at a reduced interval.

FIG. 25 is a schematic diagram showing a state in which the pattern light shown in FIG. 24 is moved and projected on a book document in conjunction with sub-scanning of document reading.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image reading device 2 main body housing 3 contact glass 4 book document 5 reflecting mirror 6 lens 7 image sensor 8 document shape detecting unit 9 document pressing plate 10 reading unit 20 document shape detecting unit 21 contact 30 document shape detecting unit 31 document 32 Infrared light emitting part 33 Infrared light receiving part 34 Infrared LED 35 Light emitting lens 36 Light receiving lens 37 Light receiving element 40 Document shape detecting part 41 Reading part 42 Light source lamp 43 Line sensor 44, 44a Light emitting part 45, 45a Light receiving part 47 Book original 48 Contact glass 50 book manuscript 51 pattern light

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06T 1/00 430 G06T 1/00 430J 3/00 200 H04N 1/04 105 3/00 200 1/387 H04N 1/04 105 1/10 1/387 F-term (reference) 2H108 AA01 CA03 CB01 5B047 AA01 BA02 BB02 BC05 BC09 BC11 BC14 CA08 CA13 CA19 CB08 CB16 CB23 DC09 5B057 AA11 BA19 BA26 CA08 CA12 CA16 CB08 CB12 CB16 CC20 DB09 DC02 5C072 AA01 BA17 CA02 DA02 DA04 DA21 EA04 LA17 MB03 RA20 TA04 VA06 5C076 AA21 AA23 BA01 BA06 BB31

Claims (6)

[Claims] A scanning means for moving the scanning means in the sub-scanning direction, irradiating the scanning means with reading light, receiving reflected light from the scanning means, and scanning the document in the main scanning direction; In an image reading apparatus that reads an image, a distance between the document on the contact glass and the contact glass is detected by a distance measuring unit, and distortion of a read image of the document read by the reading unit is detected based on the detection result. An image reading apparatus, wherein 2. The image reading apparatus according to claim 1, wherein the image reading apparatus adjusts the focus of the reading means when reading the document based on a detection result of the distance measuring means. 3. The image reading apparatus according to claim 1, wherein the image reading device adjusts a light amount of a reading light of the reading unit when reading the document based on a detection result of the distance measuring unit. 2. The image reading device according to 2. 4. The image reading device according to claim 1, wherein a moving speed of said reading means in a sub-scanning direction when reading said document is changed based on a detection result of said distance measuring means. The image reading device according to any one of claims 1 to 3. 5. The image reading apparatus according to claim 1, further comprising a moving unit configured to relatively change a binding direction of the document with respect to a main scanning direction of the reading unit, and based on a detection result of the distance measuring unit. 5. The moving device according to claim 1, wherein the relative position between the reading unit and the document is changed in a direction in which the variation in the distance between the document surface and the contact glass is reduced. 6. Image reading device. 6. The image reading apparatus according to claim 1, wherein, when the reading means is moved in the sub-scanning direction in multiple stages to read the original, the detection result of the distance measuring means is obtained in each sub-scan. 2. The method according to claim 1, wherein the main scanning is performed by changing the focal position of the reading unit to a plurality of main scanning based on the plurality of main scannings, and an image in one main scanning direction is created from the images read by the plurality of main scannings.
The image reading device according to any one of claims 1 to 3.