JP2003101733A - Image-reading apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent blurring within an imaging range for imaging by inclining an imaging camera. SOLUTION: The image-reading apparatus comprises the imaging camera 101 where an imaging element and an imaging lens are arranged inside in a specific position relationship to image a subject surface in a double-page spread manuscript, a retaining means 102 for rotatably retaining the imaging camera 101, and a rotating means for rotating at least one of the imaging lens and the imaging element in an arbitrary direction so that the subject, imaging element, and lens surface satisfy Scheinpflug conditions so that focusing is made to the entire subject surface, thus preventing blurring within an imaging range even if the imaging camera is tilted.

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 which sets a spread original document upward and reads an image on the original surface.

[0002]

2. Description of the Related Art In an image reading apparatus, a document such as a book or a file is set facing upward, and an image of a two-page spread of the document is scanned and read by an image sensor in a scanner unit provided above. Near the binding area of
Since the document surface is curved and slanted, when scanning and reading the document surface with the information image sensor, the characters in the curved and slanted portion shrink more than in the non-curved portion. There is a problem of distortion. Therefore, in the image reading apparatus disclosed in Japanese Patent Laid-Open No. 10-336393, when the tilt angle near the binding portion of the document is equal to or larger than the correction limit value, the scanner unit is tilted with respect to the document table near the binding portion. The tilt angle is adjusted according to the above, and the relative angle between the two is adjusted to keep the reading angle of the scanner unit within the correction limit value. In addition, JP-A-1
The image reading apparatus described in Japanese Patent Application Laid-Open No. 0-28202 adjusts the focus by adjusting the focus of the imaging lens when the book is opened in the main scanning direction, and the imaging camera when the book is opened in the sub scanning direction. The camera is tilted to focus. Further, the image reading apparatus disclosed in Japanese Patent Laid-Open No. 2000-200344 divides image data into a plurality of blocks and acquires a focus position in each block and its image data.
The warp or distortion of the document is identified based on the acquired in-focus position, and the image data of each block is corrected and connected based on that.

[0003]

However, in the image reading apparatus described in Japanese Patent Laid-Open No. 10-336393 mentioned above, as shown in FIG. 21, the lens surface 2102 of the image pickup camera and the image pickup element are arranged with respect to the object surface 2101. If the image pickup surface 2103 is parallel, there is no problem in focusing if the lens or the image pickup element is moved only in the optical axis direction to perform focusing, but when the camera unit is tilted by the rotating means, FIG. As shown, the subject surface in the image pickup screen and the camera distance are partially different. Even in such a case, there is no problem if the distance difference D on the screen is within the depth of field. The depth of field is determined by the permissible circle of confusion diameter, the focal length, the F-number of the image pickup lens, the distance from the camera, etc. When the pixels of the image pickup device are densified, the permissible circle of confusion diameter is reduced. Becomes narrower. In addition, the depth of field tends to be shallower because the distance to the subject is shorter than in general imaging. However, if it is not within the depth of field, one-sided blurring occurs, so it is necessary to take optical correction means.

As a countermeasure against this, there is a method of narrowing the diaphragm to deepen the depth of field. However, if the diaphragm is narrowed down, strict precision is required in terms of manufacturing and control in both the turret diaphragm and the iris diaphragm, and diffraction is required. A phenomenon may occur.
Further, since the camera is fixed, there is no fear of image blur such as camera shake, but an abnormally long image pickup time gives a feeling of strangeness to the user. Therefore, when the imaging camera is tilted, it is necessary to prevent out-of-focus within the imaging range. In addition, when tilting the subject, there must be a powerful turning means that tilts at a large angle. In addition, JP-A-10-2820
The method of changing the focusing method according to the direction in which the book is opened as in the invention described in Japanese Patent No. 2 cannot deal with the book placed obliquely. Also, Japanese Patent Laid-Open No. 2000-200
As in the invention described in Japanese Patent No. 344 publication, a method of dividing an imaging range finely to reduce the distance difference within one imaging range is as follows.
When a high resolution is not required, an unnecessarily long acquisition time is required.

[0005]

The present invention has been made in view of the above, and in the invention according to claim 1, in an image reading apparatus for picking up an object surface of a spread original document from above, an image pickup element such as CCD. And image reading means in which image forming optical means such as an imaging lens are arranged in a predetermined positional relationship,
Holding means including a stanchion and a pedestal for rotatably holding the image reading means, and the imaging optics so that the subject, the image pickup element, and the imaging optics meet the Scheimpflug condition in order to focus on the entire subject surface. And a rotating means for rotating at least one of the means and the image pickup device in an arbitrary direction. According to a second aspect of the invention, in the image reading apparatus according to the first aspect, the rotating means pans the image pickup element and the image forming optical means in different directions, specifically, one of them is panned. One direction and the other is rotated in the tilt direction. Claim 3
In the image reading device according to claim 1 or 2, the image reading device is provided with a rotation angle detecting means of the image reading means, a rotation angle detecting means of the image pickup element and the image pickup optical means, and The feature is that each rotation angle is detected at the time of reading. According to a fourth aspect of the invention, in the image reading apparatus according to the third aspect, a distortion amount calculating means for calculating the distortion amount of the imaged image based on the rotation angle detected by the rotation angle detecting means. And a distortion correcting unit that corrects the distortion of the captured image based on the calculated image distortion amount.

According to the invention of claim 5, claim 1
The image reading device according to any one of claims 1 to 4, wherein the image reading means is sequentially rotated to divide a subject into a plurality of divided regions and an image is captured, and the respective rotation angles are stored sequentially. It is characterized by imaging. According to a sixth aspect of the present invention, in the image reading apparatus according to the fifth aspect, an image obtained by dividing an object into a plurality of divided areas and sequentially picking up images is subjected to a combining process, and original image data corresponding to an arbitrary resolution is obtained. It is characterized by getting. According to a seventh aspect of the invention, in the image reading apparatus according to the fifth or sixth aspect, a focal length switching unit of the image forming optical unit is provided, and the focal length is changed according to the image pickup position to perform image pickup. Is characterized by. Further, in the invention according to claim 8, the shape of the subject is defined by the pattern projection means in which the pattern panel and the projection lens are arranged in a predetermined positional relationship, and the distortion of the pattern projected on the subject surface by the pattern projection means. A shape detecting means for detecting, and a rotation for rotating at least one of the pattern panel and the projection lens in an arbitrary direction so that the subject, the pattern panel and the projection lens satisfy the Scheimpflug condition so as to focus on the entire surface of the object. And a focusing means for focusing on the object surface based on the detection result of the shape detecting means.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the overall configuration of an image reading apparatus according to an embodiment of the present invention. This image reading apparatus is provided with an image pickup camera 101 as an image reading means for picking up an image of the spread surface of an original 100 placed on an original table as shown in FIG. 1, and a holding means 102 for holding the image pickup camera 101. There is. The image pickup camera 101 includes an image pickup lens as an image forming optical unit and an image pickup element such as a CCD. Although not shown, the holding means 1
A rotation means for changing the image pickup angle of view of the image pickup camera 101 in the direction of the arrow is provided between the column 103 of No. 02 and the image pickup camera 101, and an appropriate image pickup angle of view can be adjusted according to the document surface of the subject. I am trying. The imaging angle of view may be confirmed by displaying the captured image on a display, for example. Here, as described above, if the lens surface and the image pickup surface of the image pickup camera 101 are parallel to the subject surface, there is no problem in alignment with the pin, but if the image pickup camera 101 is tilted by the rotating means, the image pickup screen is displayed. The camera surface is partially different from the subject surface inside. Even in such a case, there is no problem if the distance difference within the screen is within the depth of field, but if it is not within the depth of field, one-sided blurring will occur, so take optical correction measures. There is a need. Therefore, when the subject surface and the lens surface and the imaging surface are not parallel to each other, in order to form an image of the entire subject surface on the image surface, as shown in FIG. The lens surface and the image pickup surface may be set so that the Scheimpflug condition that "a surface obtained by extending 203 coincides with one straight line" is satisfied. Specifically, as shown in FIGS. 3 and 4, the image pickup device 301 and the image pickup lens 401 are independently rotatable in two directions (for example, a pan direction and a tilt direction). Then, when the image pickup camera 101 is tilted for image pickup, the tilt angles of the image pickup element 301 and the image pickup lens 401 are adjusted so that the Shine-Pleuk condition is satisfied as shown in FIG. Although the rotary actuator for driving the rotary mechanism is omitted in FIG. 3,
In reality, each of the image pickup device 301 and the image pickup lens 401 requires a rotary actuator and, if necessary, a reduction mechanism.

If a rotating mechanism for satisfying the Scheimpflug condition is provided for each of the image pickup device and the image pickup lens, a space for the rotation mechanism is required and the size of the camera is increased. Therefore, either the image pickup device or the image pickup lens is required. Alternatively, the turning mechanism may be provided only. When the image pickup device is provided with the rotation mechanism, the tilt angle of the image pickup device is changed so that the image pickup surface includes the line of intersection of the lens surface and the image surface (to satisfy the Scheimpflug condition). When the image pickup lens is provided with a rotation mechanism, the tilt angle of the image pickup lens is changed so that the lens surface includes the line of intersection between the image pickup surface and the subject surface (to satisfy the Scheimpflug condition). With this configuration, the rotation mechanism provided on both the image pickup device side and the image pickup lens side only needs to be provided on either one side, and therefore the image pickup camera 10
1 can be miniaturized. In addition, it is possible to prevent defocusing when the camera portion is rotated to perform divided image pickup or when the pan and tilt rotation angles are large. Further, according to the above configuration, it is not always necessary to image the document from directly above, so that the image can be obliquely captured from the beginning as shown in FIG. The degree of freedom in the shape of the holding means is increased. By doing so, as shown in FIG. 7, the columns of the holding means are substantially vertical, and there are few protruding portions compared to the shape of the columns when an image is taken from directly above in FIG. 8, so that a spatial space can be obtained. Moreover, since the imaging camera can be arranged near the base of the holding means,
Less wobble and more stable.

When either the image pickup device or the image pickup lens is provided with a turning mechanism, as shown in FIGS. 3 and 4, the pan direction turning mechanism and the tilt direction turning mechanism are nested. A gimbal mechanism having a shape or a rotating means similar thereto is provided. Although the rotary actuator of the rotary unit is omitted in FIGS. 3 and 4, a rotary actuator and a reduction mechanism in some cases are actually required for each rotary actuator. For example, in FIG. 3, both the pan-direction rotating mechanism and the tilt-direction rotating mechanism are provided in the image pickup element, which makes the rotating means complicated and large. The same applies to the imaging lens of FIG. Therefore, as shown in FIG. 9, one rotation (for example, the pan direction) is performed by the imaging lens 901.
Rotation means on one side and rotation on the other side (eg tilt direction)
Is performed by the rotating means on the image pickup element 902 side. In this way, the rotating means can be downsized without increasing the number of rotating actuators in the imaging camera.

For the image pickup element 902 and the image pickup lens 901, a turning angle detecting means for detecting the turning angle (pan, tilt) is provided. The rotation angle detecting means is not particularly limited as long as it can obtain necessary detection accuracy, such as a resistance plate or a photo sensor. When the rotation control is remotely controlled by the stepping motor, the angle can be known by the number of input steps, so that a sensor is not necessary.
When the imaging camera is manually rotated, a click mechanism or the like is provided so that the camera is locked at a specific angle, and the locked angle is detected, whereby the angle can be easily detected. When a document is imaged by adjusting the image sensor and the imaging lens, the positional relationship between the subject surface, the lens surface, and the imaging surface can be known if the rotation angles (pan, tilt) of these are known. The amount can be obtained, and the correction amount for correcting it can be known. It is possible to correct the distorted image based on the rotation angle of the image pickup element or the image pickup lens obtained at the time of this image pickup. That is, the distortion amount calculating means and the distortion correcting means are constituted by a microcomputer or the like, and the distortion amount calculating means calculates the distortion amount of the imaged image based on the rotation angle detected by the rotation angle detecting means to correct the distortion. The distortion of the captured image is corrected based on the image distortion amount calculated by the means. As a means for obtaining a high-resolution image with an image pickup device having a limited number of pixels, a method is known in which the image pickup lens is set to the telephoto position and the image pickup position is shifted, and the subject is divided and imaged. If the focal length is doubled and half the image is taken vertically and horizontally and four data are combined so as to be stuck together, it is equivalent to that taken with a camera with double the resolution. When the image pickup camera is rotated to take a divided image, the corresponding positional relationship of the divided images is recorded based on the rotation angle of each rotation means, and the images are pasted to the correct position when they are combined. It should be done. That is, the image captured while detecting the rotation angle is corrected according to the rotation angle, and the corresponding positional relationship between the images obtained by the divided image capturing is calculated from the rotation angle.
The corrected images are combined to form one image.

Here, for example, when an image of a subject as shown in FIG. 10 is divided into four vertically and horizontally, the image pickup camera is located near the image pickup range A. Therefore, the image pickup range A and the image pickup range B are picked up. In some cases, if images are taken at the same focal length, the sizes will differ as shown in FIGS.
Even if the distortion is corrected and the complementing process is performed as it is, the image quality of the imaging range B is inferior to that of the imaging range A.
Therefore, in the case of divided image pickup, the focal length is changed depending on the image pickup position. That is, when the imaging range B is imaged, the focal length adjustment is performed so as to extend the focal length so that the object image captured in the imaging range A has substantially the same size as in FIG. Also, instead of dividing the imaging range for one shot into equal parts for the subject,
The width of the imaging range may be changed according to the distance between the subject and the imaging camera. The divided images taken at the optimum focal length for each divided region in this manner are combined by an image processing means such as a microcomputer or an image processing board to generate the entire image. When the subject has a three-dimensional shape instead of a plane, it is necessary to detect the shape of the subject and focus according to the shape in order to obtain an image in which the surface is in focus.
As a shape detection method, a method of measuring a plurality of points by a distance measuring means for autofocus of a camera, or a pattern for shape detection is projected and imaged by a projecting means, and is detected from the degree of pattern distortion in the captured image. There is a way. FIG. 14 shows an example of a camera provided with the pattern projection means 1401.
FIG. 15 shows an example in which the pattern is distorted by being projected on the subject surface.

Further, as shown in FIG. 16, it is also possible to scan while projecting a linear pattern and detect the shape from the pattern distortion. A method of actually focusing on a three-dimensional object based on the detected shape information will be described by taking an example of a page of an open book as an object as an example. Such a subject
The angle of the subject plane varies depending on the location. Therefore, according to the detected object surface shape, the rotation angle of the image pickup element or the image pickup lens is changed and the image pickup is performed in a divided manner. Since the range from a to b is within the depth of field when the imaging range for one time is from a to b, the surface α indicated by the dotted line in the figure is set to be a virtual object surface. Just take an image. Even from c to d, the surface β is virtually regarded as the object surface. Similarly, virtual subject planes γ and δ are set, and the focus and tilt are adjusted so that the respective virtual subject planes are in focus, and imaging is performed. After that, in the case of a book or the like, correction may be performed so that the image looks like an image printed on a plane. As described above, by tilting the image sensor or the imaging lens according to the shape of the subject surface, it is possible to prevent image deterioration even when capturing a subject having irregularities. The number of divisions may be further increased depending on the shape of the subject.

With respect to the pattern detecting means for shape detection provided in the image pickup camera, when the pattern projection is performed by setting the virtual projection plane parallel to the object plane as shown in FIG. Is within the depth of focus, that is, within the range of R in the figure in which the degree of out-of-focus in shape detection does not matter, but there is no problem, but when the pattern projection unit tilts with the rotation of the imaging camera, As described above, the focused position of the projection pattern is displaced and one-sided blur occurs.
Therefore, even when the projection means is rotated with the imaging camera, it is necessary to adjust the focus so that the virtual projection plane does not shift so that the projection range is within the depth of focus. Therefore, as shown in FIG. 20, the projection lens 2101 and the pattern panel 2102 are also provided with rotating means as if the imaging surface and the imaging lens were tilted by the imaging camera, and the projection pattern panel, the projection lens, and the object surface are shined. Adjust to meet the plow conditions. If there is distortion depending on the direction of rotation, the density of shape information will partly differ.Therefore, use a pattern panel as an element that can change the display, such as a liquid crystal panel, and distort the projection pattern according to the rotation angle. You may adjust so that it may not exist. In addition, by using a power transmission mechanism such as gears, belt wheels, and cams, the rotational force of the imaging camera can be transmitted to the rotation axis of the pattern mask or projection lens for rotation, and a separate actuator for the projection unit can be omitted. can do.

[0014]

As described above, according to the first aspect of the invention, in the image reading apparatus for picking up the subject surface of the spread original document from above, the image pickup element and the image pickup lens are arranged in a predetermined positional relationship. Image reading means, a holding means for rotatably holding the image reading means, and an image pickup lens and an image pickup so that the subject, the image pickup element, and the lens surface satisfy the Scheimpflug condition so as to focus on the entire subject surface. Since the rotation means for rotating at least one of the elements in one arbitrary direction is provided, it is possible to prevent defocusing within the imaging range even if the imaging camera is tilted. According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the rotating means moves the image pickup element and the image forming optical means in different directions, specifically, in either direction. Since the one is rotated in the pan direction and the other is rotated in the tilt direction, the rotating means can be downsized, and thus the image reading apparatus can be downsized. Claim 3
According to the invention described in claim 1, the image reading apparatus according to claim 1 or 2, further comprising: a rotation angle detecting means for the image pickup camera; and a rotation angle detecting means for the image pickup element and the image pickup lens. Since each rotation angle is detected, it is possible to know the imaging condition necessary to correct the distortion. According to a fourth aspect of the invention, in the image reading apparatus according to the third aspect, the distortion amount calculation for calculating the distortion amount of the imaged image based on the rotation angle detected by the rotation angle detecting means. Based on the means and the calculated image distortion amount,
Since the distortion correction means for correcting the distortion of the captured image is provided, the distortion due to the tilted imaging can be corrected and the image data can be saved.

According to a fifth aspect of the present invention, in the image reading apparatus according to any one of the first to fourth aspects, the image is obtained by dividing the subject into a plurality of divided areas for imaging. Since the reading unit is sequentially rotated and the respective rotation angles are stored to sequentially capture images, a high-resolution image can be obtained even with an image sensor having a limited number of pixels. According to a sixth aspect of the present invention, in the image reading apparatus according to the fifth aspect, the subject is divided into a plurality of divided areas, and the sequentially picked-up images are combined to perform original processing according to an arbitrary resolution. Since the image data is obtained, it is possible to compensate for the shortage of the number of pixels of the image pickup device by pasting the obtained high-resolution images. According to a seventh aspect of the invention, in the image reading apparatus according to the fifth or sixth aspect, the focal length switching means of the image forming optical means is provided, and the focal length is changed according to the image pickup position to perform image pickup. Since this is done, it is possible to reduce variations in resolution within the imaging screen when divided images are taken and then combined. Further, according to the invention of claim 8, the shape of the subject is formed by the pattern projection means in which the pattern panel and the projection lens are arranged in a predetermined positional relationship, and the distortion of the pattern projected on the subject surface by the pattern projection means. And a shape detection unit for detecting the object, and at least one of the pattern panel and the projection lens is rotated in one arbitrary direction so that the subject, the pattern panel, and the projection lens satisfy the Scheimpflug condition in order to focus on the entire object surface. Since the rotating means is provided and the object surface is focused based on the detection result of the shape detecting means, the three-dimensional shape of the object can be correctly detected even when the projection pattern is inclined and projected.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining Scheimpflug conditions of an image sensor, an imaging lens, and a subject.

FIG. 3 is a perspective view showing a rotation mechanism of the image pickup element.

FIG. 4 is a perspective view showing a rotation mechanism of the imaging lens.

FIG. 5 is a diagram showing a state of an image pickup element and an image pickup lens satisfying Scheimpflug conditions.

FIG. 6 is a perspective view showing the overall configuration of an image reading apparatus according to another embodiment.

FIG. 7 is a side view showing the overall configuration of an image reading apparatus according to another embodiment.

FIG. 8 is a side view of the image reading apparatus shown in FIG.

FIG. 9 is a perspective view showing a modified example of the rotating mechanism of the image pickup device and the image pickup lens.

FIG. 10 is a diagram for explaining a division state when a subject is divided into four vertically and horizontally and imaged.

FIG. 11 is a diagram showing the size of the imaging range A when the imaging ranges A and B are imaged at the same focal length.

FIG. 12 is a diagram showing the size of an imaging range B when imaging ranges A and B are imaged at the same focal length.

FIG. 13 is a diagram showing the size of an imaging range B in which the focal length has been adjusted so that the size of the object image captured in the imaging range A is approximately the same as that of the subject image.

FIG. 14 is a diagram showing an example of a camera provided with a pattern projection unit 1401.

FIG. 15 is a diagram showing an example in which a pattern is distorted by being projected on a subject surface.

FIG. 16: Scanning while projecting a linear pattern,
FIG. 6 is a perspective view showing an image reading apparatus configured to detect a shape from the pattern distortion.

FIG. 17 is a diagram for explaining a method for focusing on a three-dimensional object based on the detected shape information.

FIG. 18 is a diagram illustrating a case where a pattern projection unit sets a virtual projection plane parallel to a subject plane and projects a pattern.

FIG. 19 is a diagram illustrating a case where a virtual projection plane is tilted with respect to a subject plane with the rotation of an imaging camera in the pattern projection unit.

FIG. 20 is a view for explaining Scheimpflug conditions of a pattern panel, a projection lens, and a subject.

FIG. 21 is an explanatory diagram of a conventional example.

FIG. 22 is an explanatory diagram of a conventional example.

[Explanation of symbols]

100 subject, 101 imaging camera, 102 holding means, 103 support, 104 base, 201 subject plane,
202 lens surface 203 imaging surface, 301 imaging element, 401 imaging lens, 601 support, 602 pedestal, 1400 imaging camera (with pattern projection function), 1
401 pattern projection means, 1801 light source, 1802
Pattern panel, 1803 Projection lens, 1804
Virtual projection plane

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/232 H04N 5/335 Z 5C077 1/04 102 5/335 1/40 101D (72) Inventor Hasegawa Yushi 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 5B047 AA01 BA02 BB04 BC02 BC05 BC11 BC14 BC20 CB22 DC07 5C022 AA13 AB21 AC27 AC41 AC54 AC69 5C024 AX01 BX01 DX04 EX04 5C072 A20 CA17 CA02 CA02 CA02 DA02 DA23 EA08 LA12 RA12 VA06 5C076 AA11 AA36 AA40 BA01 BA06 5C077 LL02 LL19 PP59 PP66 PQ12 SS01 SS03 TT09

Claims (8)

[Claims] 1. An image reading unit in which an image pickup device and an image forming optical unit are arranged in a predetermined positional relationship, a holding unit for holding the image reading unit in a rotatable manner, and a focus on the entire subject surface. In order to achieve this, the image reading apparatus is provided with a rotating means for rotating at least one of the image forming optical means and the image pickup device in an arbitrary direction. 2. The image reading apparatus according to claim 1, wherein the rotating means rotates the image pickup element and the image forming optical means in different directions. 3. A rotation angle detecting means for the image reading means,
The image reading apparatus according to claim 1 or 2, further comprising: the image pickup device and a rotation angle detection unit of the image pickup optical unit, wherein each rotation angle is detected when an image is read. 4. A distortion amount calculating means for calculating a distortion amount of an imaged image based on the rotation angle detected by the rotation angle detecting means, and a distortion of the imaged image is corrected based on the calculated image distortion amount. The image reading device according to claim 3, further comprising: 5. The image reading means is sequentially rotated to divide an object into a plurality of divided areas for imaging, and the imaging is sequentially performed while storing each rotation angle. The image reading device according to claim 1. 6. The image reading apparatus according to claim 5, wherein the subject is divided into a plurality of divided areas, and the images sequentially picked up are combined to obtain original image data corresponding to an arbitrary resolution. . 7. The image reading apparatus according to claim 5, further comprising a focal length switching unit of the image forming optical unit, wherein the focal length is changed according to the image pickup position to perform image pickup. 8. A pattern projecting means in which a pattern panel and a projection lens are arranged in a predetermined positional relationship, and shape detecting means for detecting the shape of a subject by distortion of a pattern projected on the subject surface by the pattern projecting means. An image reading apparatus comprising: a rotation unit configured to rotate at least one of the pattern panel and the projection lens in an arbitrary direction in accordance with the rotation of the image reading unit.