JPH06139340A - Image forming method and image pickup device - Google Patents

Abstract

PURPOSE:To easily two-dimensionally move the position of the image formed on an image pickup element to easily generate a picture with high resolution by changing the form of an active prism arranged in an incident light path. CONSTITUTION:An active prism 6 whose form can be varied is arranged in the incident light path of an image pickup element 2, where plural photodetectors are arranged, to move the incident light in the diametral direction of a lens 4. That is, the form of the active prism 6 is changed to obtain the image picked up after movement of the image in the lateral direction by a half of the gap between photodetectors of the image pickup element 2 and the image picked up before this movement, and these images are synthesized to enhance the resolution in the lateral direction twice. In the same manner, the resolution in the longitudinal direction in enhanced. The extent of movement of the image formed on the image pickup face is reduced and many images are picked up by this reduction, and many images obtained then are synthesized to enhance the resolution furthermore.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image generating method and an image pickup apparatus.

[0002]

2. Description of the Related Art As shown in FIG.
The image capturing using the image sensor 2 in which the two-dimensional array is arranged or the image sensor in which the light receiving elements are one-dimensionally arranged (for example, photodiode array, linear sensor, CCD, etc.) This is performed by sensing the brightness or the like in each light receiving element 2R of the image formed on the image pickup element 2. The resolution of the image obtained in this case is
It is determined only by the number of light receiving elements 2R arranged in the image pickup element 2.

The number of light-receiving elements 2R arranged one-dimensionally or two-dimensionally in the image pickup device 2 cannot be set to a certain number or more due to problems in the manufacturing process of the image pickup device 2. Therefore, an image having a necessary and sufficient resolution may not be obtained.

For example, in Japanese Patent Application No. 4-93806, light emitted from a light source to an object to be measured is imaged on an image pickup device in which photodiodes are two-dimensionally arranged, and each photodiode is imaged. On the other hand, it is disclosed that the distance image is obtained in real time by the principle of triangulation. However, even with regard to this image pickup device, it is not possible to manufacture an element with sufficient resolution due to the current semiconductor process, price, etc. It's pretty difficult.

On the other hand, in CCDs, a resolution of several thousands × several thousands has been obtained, but a higher resolution is also required.

IEEE TRANSACTIONS O
N ELECTRON DEVI-CES, VOL. E
D-32, NO. 8, 150 of AUGUST 1985
See “Image Fli” on pages 5 to 1510.
cker Control CCD-Chip-S
hift and Wobble Operat-io
n at Double-Enhanced Nyqu
In an article titled "ist Regions", in an attempt to increase the resolution of an image, the image sensor is vibrated using a piezo element or the like to change the position on the image sensor side, and the positional relationship between the formed image and the image sensor is changed. It is disclosed that an image having a resolution of several times is generated by synthesizing a plurality of captured images while displacing relative to each other in subpixel units.

FIG. 7 shows a case where an image pickup device 2 in which m light receiving elements in the horizontal direction and n light receiving elements in the vertical direction are two-dimensionally arranged and the pitch between the light receiving elements in the horizontal direction is p is moved. , An example of a conventional method for obtaining a high-resolution image is shown. In this example, the image sensor 2 captures an image at a predetermined position, and then the image sensor is moved by a distance p / 2 that is half the light receiving element interval p in the horizontal direction to capture an image, and the two captured images are captured. An image having double the resolution in the horizontal direction is obtained by superimposing the images of 1 to form one image 12.

[0008]

However, the above-described conventional method for moving the image pickup device to obtain a high-resolution image is a method in which the size of the image pickup device is large, the weight of the image pickup device is large, or the movement of the image pickup device is large. When the amount is large, it is difficult to move the image sensor. In particular, when it is desired to increase the resolution in two directions of the image sensor, that is, the vertical direction and the horizontal direction, it is necessary to overlap the vertical drive unit and the horizontal drive unit of the image sensor with each other, which is mechanically large. It becomes a thing.

A first object of the present invention is to provide an image generating method capable of easily moving the position of an image formed on an image pickup device two-dimensionally.

A second object of the present invention is to provide an image generating method capable of easily generating a high resolution image.

A third object of the present invention is to provide an image pickup apparatus which can easily two-dimensionally move the position of the image formed on the image pickup element.

[0012]

According to a first aspect of the present invention, there is provided an active prism having a variable shape (for example, as shown in FIG. 1) in an incident light path of an image pickup device (for example, as shown in FIG. It is characterized in that the position of the image formed on the image pickup device is moved by disposing the active prism 6) and changing the shape of the active prism.

According to a second aspect of the image generation method, incident light of an image pickup device (for example, the image pickup device 2 of FIGS. 1 and 5) in which a plurality of light receiving devices (for example, the light receiving device 2R of FIG. 5) are arranged. By disposing an active prism having a variable shape (for example, the active prism 6 in FIG. 1) in the path, and changing the shape of the active prism, the position of the image formed on the image pickup element can be set to the distance between the light receiving elements. (For example, in FIG.
Distance (for example, pitch p in FIG. 5)
It is characterized in that the images output from the image pickup device are combined before and after the image position movement by moving only / 2).

According to a third aspect of the present invention, there is provided an image pickup device including an image pickup element (for example, the image pickup element 2 in FIG. 1) and an active prism having a variable shape arranged in an incident light path of the image pickup element (for example, FIG. 1). Active prism 6) and shape control means (for example, prism control unit 8 in FIG. 1) that changes the shape of the active prism in order to move the position of the image formed on the image sensor. And

[0015]

According to the image generating method of the present invention, the shape of the active prism disposed in the incident light path of the image pickup device is changed to move the position of the image formed on the image pickup device. To be

In the image generating method of the second aspect of the invention, the shape of the active prism disposed in the incident light path of the image pickup device in which a plurality of light receiving elements are arranged is changed to form an image on the image pickup device. The position of the formed image is moved by a distance smaller than the distance between the light receiving elements, and the images output from the image pickup element before and after the image position movement are combined.

According to another aspect of the image pickup device of the present invention, the shape of the active prism disposed in the incident light path of the image pickup device is changed by the shape control means, and the position of the image formed on the image pickup device is changed. Can be moved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of an embodiment of the image pickup apparatus of the present invention. A lens 4 forming a predetermined optical system and an active prism 6 having a variable shape are arranged in an incident light path of the image sensor 2 in which a plurality of light receiving elements are arranged. Conventionally, incident light is focused on the light receiving element of the image pickup element 2 through the lens 4 constituting the optical system, but in the present embodiment, the active prism 6 is arranged in front of the lens 4,
The incident light is moved (shifted) in the radial direction of the lens 4.

FIG. 2 shows an example of the active prism 6. This active prism joins two glass plates 62 and 64 by a bellows 64, into which the glass 6
2 and 64 filled with liquid 68 having the same refractive index. The two glass plates 62 and 64 are bellows 6 with respect to each other.
Although the movement is restricted by being combined by 4, it is possible to move freely within this restriction range.

FIG. 3 shows a modification of the shape of the active prism 6 of FIG. 2, and FIG. 4 shows a modification of the optical path corresponding to the modification of the shape of the active prism 6 of FIG. When the shape of the active prism changes, for example, as shown in FIGS. 3A to 3D, prisms optically equivalent to these prisms are as shown in FIGS. 4A to 4D. The optical path of the light that can be represented and that passes through the prism is shown in FIG.
This is indicated by the arrows in (a) to FIG. 4 (d). This optical path is
Within the range in which the glass plates 62 and 64 can be moved, both the vertical direction and the horizontal direction can be freely changed. Further, the magnitude of the movement (shift) of the optical path can be accurately controlled by quantitatively controlling the shape change amount of the active prism 6 by the prism controller 8 in FIG. That is, by using the active prism 6, it is possible to accurately and easily move the position of the image formed on the image pickup element 2 two-dimensionally in any direction by an arbitrary amount.

FIG. 5 shows an example of an image generating method for obtaining a high resolution image by changing the shape of the active prism 6 in the embodiment of FIG. That is, the example of FIG.
By changing the shape of the active prism, the image captured by laterally moving the image by half the light receiving element interval (that is, the pitch p) of the image sensor 2 and the image captured before the movement are combined. By doing so, the resolution in the horizontal direction is doubled.

First, FIG. 5A shows a state in which the image 10 is formed on the image pickup device 2 before the active prism 6 is moved. FIG. 5B shows a state in which the active prism 6 is operated and the image 10 on the image pickup element 2 is laterally displaced by half the distance between the light receiving elements in the horizontal direction (that is, p / 2).

FIG. 5C shows an image 10 formed on the image pickup element 2 as shown in FIG. It shows the sense. That is, FIG. 5C shows that a triangular image is formed on the light-receiving element 2R that is painted black, and the resolution of this image is the number of light-receiving elements 2R in the image-pickup element 2. Is determined by.

In FIG. 5D, the image 10 formed on the image pickup element 2 as shown in FIG. 5B is displayed by each light receiving element 2R arranged in the image pickup element 2. It shows the sense. That is, FIG. 5D shows that a triangular image is formed on the light-receiving element 2R that is painted black.

FIG. 5 (e) is obtained by synthesizing, that is, superimposing the image captured as shown in FIG. 5 (c) and the image captured as shown in FIG. 5 (d). ,
An image 12 on the memory having a resolution doubled in the horizontal direction is shown. That is, the image obtained by shooting as shown in FIG. 5C is stored in the buffer, and the image obtained by shooting as shown in FIG. 5D is also stored in the buffer. Corresponding pixels in the image obtained by the capturing of FIG. 5D are embedded between pixels in the horizontal direction of the image obtained by the capturing of (c). As a result, one image having a double horizontal resolution is generated from the two images.

Although the example of FIG. 5 is an example of increasing the resolution in the horizontal direction, the resolution in the vertical direction can be similarly increased.

The example of FIG. 5 is an example in which the resolution is doubled, but the amount of movement of the image formed on the image pickup surface is reduced, and a large number of images are captured correspondingly. The resolution can be further increased by synthesizing the images of.

In addition to the grayscale image, for example, the resolution (resolution) of the image obtained from the imaging surface of the distance measuring device disclosed in Japanese Patent Application No. 4-93806 is increased several times in both the vertical and horizontal directions. It becomes possible.

Further, generally, it becomes possible to increase the resolution of an image formed by forming an image on the image pickup surface in which the light receiving elements are arranged one-dimensionally or two-dimensionally.

In the above embodiment, the image pickup device 2
On the other hand, although the active prism 6 is disposed farther than the lens 4, the active prism 6 may be disposed between the lens 4 and the image pickup element 2.

[0031]

According to the image generating method of claim 1, the shape of the active prism disposed in the incident light path of the image pickup device is changed to move the position of the image formed on the image pickup device. Since this is done, the position of the image can be easily moved two-dimensionally.

According to the image generating method of the second aspect, the shape of the active prism arranged in the incident light path of the image pickup device in which the plurality of light receiving elements are arranged is changed to form an image on the image pickup device. By moving the image position by a distance smaller than the distance between the light receiving elements and combining the images output from the image sensor before and after moving the image position, it is easy to obtain an image with a resolution higher than the resolution specific to the image sensor. Obtainable.

According to the image pickup apparatus of the third aspect, the position of the image formed on the image pickup element is changed by changing the shape of the active prism arranged in the incident light path of the image pickup element by the shape control means. Since the image is moved, the position of the image can be easily moved two-dimensionally.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of an image pickup apparatus of the present invention.

FIG. 2 is a diagram showing a configuration example of an active prism 6 in FIG.

FIG. 3 is a diagram showing an example of a change in shape of the active prism 6 of FIG.

FIG. 4 is a diagram showing a variation example of an optical path corresponding to a variation example of the shape of the active prism 6 in FIG.

5 is an explanatory diagram showing an example of an image generation method for obtaining a high-resolution image by changing the shape of the active prism 6 in the embodiment of FIG.

FIG. 6 is a diagram showing a configuration example of a conventional image sensor.

FIG. 7 is an explanatory diagram showing an example of a conventional image generation method for obtaining a high-resolution image by moving an image sensor.

[Explanation of symbols]

 2 image sensor 2R light receiving element 6 active prism 8 prism control unit 10 image 62 glass plate 64 bellows 66 glass plate 68 liquid

Claims (3)

[Claims] 1. An active prism having a variable shape is disposed in an incident light path of an image sensor, and the position of an image formed on the image sensor is moved by changing the shape of the active prism. An image generation method characterized by the above. 2. An image is formed on the image pickup device by disposing an active prism having a variable shape in an incident light path of the image pickup device in which a plurality of light receiving elements are arranged and changing the shape of the active prism. The image generation method comprising: moving the position of the image to be moved by a distance smaller than the distance between the light receiving elements, and synthesizing the images output from the image pickup element before and after the image position movement. 3. An image pickup device, an active prism having a variable shape, which is disposed in an incident light path of the image pickup device, and the active prism for moving a position of an image formed on the image pickup device. And a shape control unit that changes the shape of the image pickup apparatus.