JP4043091B2 - Image input method, image input device, electronic camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image input method, an image input device, and an electronic camera.
[0002]
[Prior art]
Conventionally, there is a device that captures an image of a subject in a two-dimensional solid-state imaging device in which a large number of light-receiving elements are arranged in a matrix. The resolution of the captured image is determined by the number of pixels of the two-dimensional solid-state imaging device. However, there is a limit to increasing the number of pixels per unit area (corresponding to the arrangement density of the light receiving elements) of the two-dimensional solid-state imaging device. Therefore, in order to increase the resolution of an image to be captured even if the number of pixels per unit area of the two-dimensional solid-state imaging device is small, proposals described in Japanese Patent Laid-Open Nos. 63-191383 and 6-141228 have been made. ing.
[0003]
In the invention described in Japanese Patent Laid-Open No. 63-191383, a detector in which n × m two-dimensional solid-state image sensors are arranged close to each other and arranged vertically and horizontally is disposed between the detector and a subject. By rotating the condensing optical system in a two-dimensional direction perpendicular to the optical axis, corresponding field images are sequentially formed on each two-dimensional solid-state image sensor, and a plurality of field images are captured. By synthesizing and restoring one frame image, the number of pixels of the two-dimensional solid-state imaging device is effectively increased to n × m times so that a high-resolution image can be obtained.
[0004]
In the invention described in Japanese Patent Laid-Open No. 6-141228, a mirror is intermittently rotated in one scanning direction so that an image of a subject is partially imaged and captured on an image pickup device. The captured image area overlaps the current image area to be captured, and the image blur is corrected by the image blur correction circuit.The captured image is reconstructed in this way to reconstruct the entire subject image at high resolution. I try to take an image. In addition, the publication also describes details of fixing an electronic camera composed of an image sensor and a condensing optical system and moving a document in a two-dimensional plane direction on a stage when reading a document image in a divided manner. Yes.
[0005]
[Problems to be solved by the invention]
The invention described in Japanese Patent Application Laid-Open No. 63-191383 uses a plurality of two-dimensional solid-state imaging elements, so that the area of the imaging surface increases and the apparatus becomes large. Further, since it is necessary to move the condensing optical system with very high accuracy in order to shoot images so that the divided images are continuously connected in adjacent portions, the apparatus becomes complicated and the cost increases. Furthermore, when the electronic camera is photographed by hand, the electronic camera may move, and the divided and captured images may not be connected.
[0006]
The invention described in Japanese Patent Application Laid-Open No. 6-141228 has no particular problem when shooting a subject at a distance, but when the document image is divided and shot by rotating the mirror, As the scanning angle increases, defocusing and image distortion occur, resulting in poor resolution. In addition, as described above, the electronic camera is fixed and the document is moved on the stage. However, since the moving range of the document is large, the stage becomes large and the entire apparatus becomes large.
[0007]
The number of pixels of a screen displayed on a currently popular personal computer or the like is usually 640 × 480 to 1280 × 1024, the total number of pixels is 300,000 or more, and even a high pixel is about 1.3 million. On the other hand, as an example of the A4 version, the document image is about 8.7 million pixels in the case of 300 dpi and about 15.5 million pixels in the case of 400 dpi. This number of pixels far exceeds the number of pixels of a normal electronic camera, and a normal electronic camera cannot capture a document image at a high resolution even if a general subject can be captured.
[0008]
[Means for Solving the Problems]
The image input device according to claim 1 is tilted in a two-dimensional direction about a condensing optical system having a field flat function for emitting light incident from a subject as parallel light, and two axes orthogonal to each other as rotation centers. The subject is divided into a plurality of regions, a movable mirror for deflecting the light in the divided regions, and imaging optics for imaging the light in the region divided by the movable mirror as an image on a two-dimensional solid-state imaging device And a synthesizing unit that synthesizes the images formed by the imaging optical system to generate an image of the subject.
[0009]
Therefore, by rotating the movable mirror in the two-dimensional direction, it is possible to set the image area of the subject to be divided and captured in accordance with the number of pixels of the two-dimensional solid-state imaging device. The images that are divided and captured in this way are combined as a single image by the combining means. In this case, even if the movable mirror is largely inclined with respect to the subject, the image from the subject is condensed on the movable mirror by the condensing optical system.
[0010]
According to a second aspect of the present invention, there is provided an electronic camera having a two-dimensional solid-state imaging device, a condensing optical system having a field flat function for emitting light incident from a subject as parallel light, and two axes orthogonal to each other as rotation centers. The subject is divided into a plurality of regions by tilting in a two-dimensional direction, and a movable mirror that deflects the light in the divided regions, and the light in the region divided by the movable mirror as an image on a two-dimensional solid-state imaging device An object including an imaging optical system that forms an image, the movable mirror and a condensing optical system, and detachably attached to an imaging unit having the two-dimensional solid-state imaging device and the imaging optical system A partial reading unit for increasing the resolution when the image is a document image, and a combining unit that combines the images formed by the imaging optical system to generate an image of the subject. .
[0011]
Therefore, by rotating the movable mirror in the two-dimensional direction, it is possible to set the image area of the subject to be divided and captured in accordance with the number of pixels of the two-dimensional solid-state imaging device. The images that are divided and captured in this way are combined as a single image by the combining means. In this case, even if the movable mirror is largely inclined with respect to the subject, the image from the subject is condensed on the movable mirror by the condensing optical system. Further, when photographing a distant subject, a high resolution is not required as in the case of capturing a document image, so that the operability can be improved by removing the partial reading unit from the imaging unit.
[0012]
According to a third aspect of the present invention, there is provided an electronic camera having a two-dimensional solid-state imaging device, a condensing optical system having a field flat function for emitting light incident from a subject as parallel light, and two axes orthogonal to each other as rotation centers. A movable mirror that divides the subject into a plurality of regions by tilting in a two-dimensional direction, an imaging optical system that images each of the regions divided by the movable mirror on a two-dimensional solid-state imaging device, and the imaging optics The camera body includes combining means for combining the images formed by the system to generate an image of the subject.
[0013]
Therefore, by rotating the movable mirror in the two-dimensional direction, it is possible to set the image area of the subject to be divided and captured in accordance with the number of pixels of the two-dimensional solid-state imaging device. The images that are divided and captured in this way are combined as a single image by the combining means. In this case, even if the movable mirror is largely inclined with respect to the subject, the image from the subject is condensed on the movable mirror by the condensing optical system. Furthermore, since all the components are incorporated in the camera body, the configuration of the electronic camera can be simplified.
[0014]
According to a fourth aspect of the present invention, there is provided the electronic camera according to the second or third aspect, wherein the movable mirror includes a plurality of reflecting plates that are rotatable in a two-dimensional direction with two axes orthogonal to each other as a rotation center. A micromirror array is used.
[0015]
Therefore, since it is not necessary to displace the entire micromirror array when changing the image area of the subject, the micromirror array can be installed in a small installation space.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. First, FIG. 1 shows the configuration of the image input apparatus 1. The image input apparatus 1 includes a two-dimensional solid-state imaging device 2 in which a large number of light-receiving elements (not shown) are arranged in a matrix, and an imaging optical system (lens) that faces the light-receiving surface of the two-dimensional solid-state imaging device 2. 3, a movable mirror 5 that deflects an image divided vertically and horizontally into an imaging optical system 3 by tilting it in a two-dimensional direction around two axes orthogonal to each other as a rotation center, and an image of the subject A condensing optical system (lens) 6 that emits light toward the incident surface of the movable mirror 5, and a two-dimensional solid-state imaging device sequentially through the condensing optical system 6, the movable mirror 5, and the imaging optical system 3. And a combining means (not shown) for connecting the divided images of the subject 4 imaged on 2 and combining them into one image.
[0021]
In this case, the rotation direction of the movable mirror 5 is the direction of the arrow shown in FIGS. 3 and 4 and the direction orthogonal to the arrow. In this example, one movable mirror 5 is rotated in a two-dimensional direction, but a configuration in which two movable mirrors that rotate only in one direction orthogonal to each other may be used.
[0022]
Next, an image input method for capturing an image of the subject 4 using such an image input apparatus 1 will be described. The subject 4 in this example is a document image on the desk. Each time the movable mirror 5 disposed between the subject 4 in the observation field of view and the imaging optical system 3 is tilted in a two-dimensional direction around two axes orthogonal to each other as the rotation center, the subject 4 deflected by the movable mirror 5 The operation of sequentially imaging the vertically and horizontally divided images on the two-dimensional solid-state imaging device 2 by the imaging optical system 3 is repeated a plurality of times.
[0023]
FIG. 2 shows that the subject (document) 4 is divided into four image areas (1), (2), (3), and (4) to capture an image, and the image area captured at one time is captured in the previous time. Specifically, the size is determined to overlap with the periphery of the area. Specifically, as indicated by an arrow in FIG. 3, the movable mirror 5 is rotated clockwise to capture the image in the image area (1). As indicated by an arrow in FIG. 4, the movable mirror 5 is rotated counterclockwise to capture an image in the image area (2). When capturing an image in the image area (3) (4), the movable mirror 5 is rotated in a direction orthogonal to the arrow direction shown in FIGS.
[0024]
In this way, by rotating the movable mirror 5 in the two-dimensional direction, the image area (1) (2) (3) (4) of the subject 4 to be divided and captured is set to the number of pixels of the two-dimensional solid-state imaging device 2. It is possible to set together. The image captured in a divided manner in this way has a higher resolution than the conventional one even in the pixels of one two-dimensional solid-state imaging device 2, and by combining the images captured in a divided manner as a single image, Even in the case of a document image, the resolution can be increased. In this example, the image area is divided into four (1), (2), (3), and (4), so that one document image can be captured with a resolution that is four times the number of pixels of the two-dimensional solid-state imaging device 2. it can.
[0025]
Further, by providing the condensing optical system 6 with a field flat function for flattening the image, even if the movable mirror 5 is largely inclined with respect to the subject 4, distortion and defocusing occur in the peripheral portion of the captured image. Can be prevented.
[0026]
In addition, as shown in FIG. 2, the size of the image area of (1), (2), (3), and (4) to be captured at a time is set to a size that overlaps with the area of the previously captured image area. Therefore, it is not necessary to precisely set the image area to be captured at a time, and there is no need to control the movement amount of the movable mirror 5 with high accuracy. Thereby, the configuration of the control system can be simplified. As a method of synthesizing images captured by overlapping, feature points are extracted and specified in the overlapped image region, and divided images are connected using the specified portion as a mark.
[0027]
Next, a second embodiment of the present invention will be described with reference to FIGS. Since the present embodiment is an example in which the configuration of the image input device 1 in the previous embodiment is applied to an electronic camera, the same parts as those of the image input device 1 are denoted by the same reference numerals, and description thereof is also omitted.
[0028]
An electronic camera 7 shown in FIG. 5 includes an imaging unit 8 and a partial reading unit 9 and a combining unit (not shown) that connects the divided images and combines them into one image. The imaging unit 8 has a two-dimensional solid-state imaging device 2 and an imaging optical system 3 in a main body case 10, and the partial reading unit 9 has a movable mirror 5 and a condensing optical system 6 in a unit case 11. The characteristics of the two-dimensional solid-state imaging device 2, the imaging optical system 3, the movable mirror 5, and the condensing optical system 6 are the same as those in the previous embodiment.
[0029]
In such an electronic camera 7, when capturing a document image, as shown in FIG. 5, the condensing optical system 6 is directed toward the subject 4 as a document, and the direction of the movable mirror 5 is changed as described above. A divided image divided for each region is taken in, and the divided and taken-in images are combined as a single image.
[0030]
In this case, since the unit case 11 of the partial reading unit 9 is detachably attached to the main body case 10, as shown in FIG. 6, when capturing a distant subject 12, a document image is captured. Since the resolution is not so high, the unit case 11 of the partial reading unit 9 can be removed from the main body case 10 of the imaging unit 8 and the operability can be improved.
[0031]
Next, a third embodiment of the present invention will be described with reference to FIGS. Since this embodiment is also an example in which the configuration of the image input apparatus 1 in the previous embodiment is applied to an electronic camera, the same parts as those of the image input apparatus 1 are denoted by the same reference numerals and description thereof is omitted.
[0032]
The electronic camera 13 shown in FIG. 7 includes a camera body 14, a two-dimensional solid-state imaging device 2, an imaging optical system 3, a micromirror array 15 as a movable mirror, a condensing optical system 16, and divided divided images. And combining means (not shown) for combining the images into one image. As shown in FIG. 8, the micromirror array 15 has a large number of reflectors 17 arranged in a matrix. The micromirror array 15 includes a matrix electrode (not shown) arranged on the back surface, and a large number of reflectors 17 are simultaneously synchronized by changing the magnitude and polarity of the voltage applied to the matrix electrode. Like the movable mirror 5 described above, it is configured to rotate in a two-dimensional direction. Further, the condensing optical system 16 has a field flat function of emitting the incident light diffused from one point of the subject 4 or 12 as parallel light in addition to the function of condensing the incident image on the micromirror array 15. I have.
[0033]
With such an electronic camera 13, it is possible to capture both the image of the distant subject 12 and the image of the subject 4 as a document. As shown in FIG. 7, when capturing a distant image, the orientation of the reflector 17 of the micromirror array 15 may be fixed, and the image of the subject 12 may be captured at once without being divided. The image of the subject 12 may be divided and captured by rotating.
[0034]
Next, an operation of dividing and capturing an image by changing the direction of the reflecting plate 17 of the micromirror array 15 will be described by taking a document image capturing operation as an example. When the document image is captured, the reflecting plate 17 of the micromirror array 15 is rotated in the direction in which the image in the image area {circle around (1)} (see FIG. 2) is incident on the two-dimensional solid-state image pickup device 2, thereby FIG. As shown in the figure, the image of the image area (1) is captured, and the reflecting plate 17 of the micromirror array 15 is rotated in the direction in which the image of the image area (2) (see FIG. 2) is incident on the two-dimensional solid-state imaging device 2. As shown in FIG. 10, the image in the image area (2) is captured. When capturing an image in the image area (3) (4) (see FIG. 2), the reflecting plate 17 is rotated in a direction in which the image in the image area (3) (4) is incident on the two-dimensional solid-state imaging device 2.
[0035]
In this case, as shown in FIG. 11, the reflected light (image) from, for example, point B of the subject 4 (the same applies to any other point from point A to point C) is diffused and incident on the condensing optical system 16. However, since the light can be incident on the micromirror array 15 as parallel light by the condensing optical system 16 having a field flat function, the image of the point B is imaged by the imaging optical system 3. Two points can be imaged. Thereby, even when the micro mirror array 15 is used as the movable mirror, the image of the subject 4 can be accurately captured.
[0036]
Thus, it is not necessary to rotate the entire micromirror array 15 by rotating the reflecting plate 17 when changing the image area of the subject 4, thereby installing the micromirror array 15 in a small installation space. The structure of the electronic camera 13 can be reduced in size.
[0037]
In addition, since all the components (two-dimensional solid-state imaging device 2, imaging optical system 3, micromirror array 15, condensing optical system 16, and combining means are incorporated in the camera body 14, the configuration of the electronic camera 13 is simplified. can do.
[0038]
【The invention's effect】
The image input device according to claim 1 is tilted in a two-dimensional direction about a condensing optical system having a field flat function for emitting light incident from a subject as parallel light, and two axes orthogonal to each other as rotation centers. A movable mirror that divides the subject into a plurality of regions and deflects the light in the divided regions, and imaging optics that forms an image of the light in the region divided by the movable mirror as an image on a two-dimensional solid-state imaging device And a synthesizing unit that synthesizes each of the images imaged by the imaging optical system to generate an image of the subject, so that by rotating the movable mirror in a two-dimensional direction, The image area of the subject to be divided and captured can be set according to the number of pixels of the two-dimensional solid-state imaging device. Since the images that are divided and captured in this way are combined as a single image by the combining means, the resolution can be increased without increasing the number of pixels of the two-dimensional solid-state image sensor even in the case of a document image. Further, by providing the condensing optical system with a field flat function for flattening the image, even if the movable mirror is largely inclined with respect to the subject, it is possible to prevent occurrence of distortion and defocusing in the peripheral portion of the captured image.
[0039]
According to a second aspect of the present invention, there is provided an electronic camera having a two-dimensional solid-state imaging device, a condensing optical system having a field flat function for emitting light incident from a subject as parallel light, and two axes orthogonal to each other as rotation centers. The subject is divided into a plurality of regions by tilting in a two-dimensional direction, and a movable mirror that deflects the light of the divided regions, and the light of the region divided by the movable mirror is displayed as an image on a two-dimensional solid-state imaging device. An object including an imaging optical system that forms an image, the movable mirror and a condensing optical system, and detachably attached to an imaging unit having the two-dimensional solid-state imaging device and the imaging optical system A partial reading unit for increasing the resolution when the image is a document image, and a combining unit that combines the images formed by the imaging optical system to generate an image of the subject. Because By pivoting the movable mirror in the two dimensional direction, the image area of the subject to capture divided can be set according to the number of pixels of the two-dimensional solid-state imaging device. Since the images that are divided and captured in this way are combined as a single image by the combining means, the resolution can be increased without increasing the number of pixels of the two-dimensional solid-state image sensor even in the case of a document image. Furthermore, when the subject image is divided and captured, the condensing optical system is provided with a field flat function for flattening the image, so that the peripheral portion of the captured image can be obtained even if the movable mirror is tilted largely with respect to the subject. It is possible to prevent the occurrence of distortion and defocusing. Further, when photographing a distant subject, a high resolution is not required as in the case of capturing a document image, so that the operability can be improved by removing the partial reading unit from the imaging unit.
Therefore, it is not necessary to displace the entire micromirror array at the time, so that the space for installing the micromirror array can be reduced in the space, which contributes to downsizing of the electronic camera.
[0040]
According to a third aspect of the present invention, there is provided an electronic camera having a two-dimensional solid-state imaging device, a condensing optical system having a field flat function for emitting light incident from a subject as parallel light, and two axes orthogonal to each other as rotation centers. A movable mirror that divides the subject into a plurality of regions by tilting in a two-dimensional direction, an imaging optical system that images each of the regions divided by the movable mirror on a two-dimensional solid-state imaging device, and the imaging optics Since the camera body is provided with a synthesizing unit that synthesizes the images formed by the system to generate the image of the subject, the image is divided and captured by rotating the movable mirror in a two-dimensional direction. The image area of the subject can be set according to the number of pixels of the two-dimensional solid-state image sensor. Since the images that are divided and captured in this way are combined as a single image by the combining means, the resolution can be increased without increasing the number of pixels of the two-dimensional solid-state image sensor even in the case of a document image. Furthermore, even when the image of the subject is divided and captured, even if the inclination of the movable mirror with respect to the subject is large, the image from the subject is condensed on the movable mirror by the condensing optical system. It is possible to prevent out of focus. Furthermore, since all the components are incorporated in the main body case, the configuration of the electronic camera can be simplified.
[0041]
According to a fourth aspect of the present invention, there is provided the electronic camera according to the second or third aspect, wherein the movable mirror includes a plurality of reflecting plates that are rotatable in a two-dimensional direction with two axes orthogonal to each other as a rotation center. Because the micromirror array is used, it is not necessary to displace the entire micromirror array when changing the image area of the subject. can do.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of an image input apparatus according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a relationship between a document image and divided areas for dividing and capturing the document image.
FIG. 3 is an explanatory diagram illustrating a state in which an image of one divided region of a subject is captured.
FIG. 4 is an explanatory diagram illustrating a state in which an image of another divided region of a subject is captured.
FIG. 5 is an explanatory diagram showing a configuration of an electronic camera according to a second embodiment of the present invention.
FIG. 6 is an explanatory diagram illustrating a state in which a remote subject is photographed with the partial reading unit removed.
FIG. 7 is an explanatory diagram showing a configuration of an electronic camera according to a third embodiment of the present invention.
FIG. 8 is a perspective view of a micromirror array.
FIG. 9 is an explanatory diagram illustrating a state in which an image of one divided region of a subject is captured.
FIG. 10 is an explanatory diagram illustrating a state in which an image of another divided region of a subject is captured.
FIG. 11 is an explanatory diagram showing the light condensing action of the condensing optical system.
[Explanation of symbols]
2 Two-dimensional solid-state imaging device 3 Imaging optical system 4 Subject 5 Movable mirror 6 Condensing optical system 8 Imaging unit 9 Partial reading unit 12 Subject 14 Body case 15 Movable mirror, micromirror array 16 Condensing optical system 17 Reflecting plate

Claims (4)

A condensing optical system having a field flat function of emitting light incident from a subject as parallel light;
A movable mirror that divides the subject into a plurality of regions by tilting two axes perpendicular to each other in a two-dimensional direction around a rotation center, and deflecting light in the divided regions;
An imaging optical system that forms an image of light in the region divided by the movable mirror as an image on a two-dimensional solid-state imaging device;
An image input apparatus comprising: a combining unit configured to combine the images formed by the imaging optical system to generate an image of the subject. A two-dimensional solid-state imaging device;
A condensing optical system having a field flat function of emitting light incident from a subject as parallel light;
A movable mirror that divides the subject into a plurality of regions by tilting two axes perpendicular to each other in a two-dimensional direction around a rotation center, and deflecting light in the divided regions;
An imaging optical system that forms an image of light in a region divided by the movable mirror on a two-dimensional solid-state image sensor;
In order to increase the resolution when the subject is a document image, which includes the movable mirror and the condensing optical system, and is detachably attached to the imaging unit having the two-dimensional solid-state imaging device and the imaging optical system. A partial reading unit of
An electronic camera comprising: combining means for combining the images formed by the imaging optical system to generate an image of the subject. A two-dimensional solid-state imaging device;
A condensing optical system having a field flat function of emitting light incident from a subject as parallel light;
A movable mirror that divides the subject into a plurality of regions by inclining in two dimensions around two axes orthogonal to each other;
An imaging optical system that images each of the regions divided by the movable mirror onto a two-dimensional solid-state imaging device;
An electronic camera comprising a camera body having combining means for combining the images formed by the image forming optical system to generate an image of the subject.   4. The electronic camera according to claim 2, wherein the movable mirror is a micromirror array in which a large number of reflecting plates that are rotatable in two dimensions about two axes orthogonal to each other are arranged in a matrix.

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