JP2003007994A - Solid-state image pickup element, stereoscopic camera apparatus, and range finder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-state image pickup element that can generate image signals capable of forming a stereoscopic image by itself from the image of an object received at different incident angles through one-time image pickup. SOLUTION: This solid-state image picking-up element 1 has many pixels arranged on the same image picking-up surface 3, and generates the image signals by performing photoelectric conversion on the objective image formed on the image forming surface. The pixels 3 are divided into two groups and the light receiving incident angles of the pixels in each groups are made different from each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device, a stereoscopic camera device, and a distance measuring device, and more particularly to a solid-state image pickup device capable of generating image signals picked up by different light-receiving incident angles with one solid-state image pickup device. The present invention relates to an element, a stereoscopic camera device using the same, and a distance measuring device.

[0002]

2. Description of the Related Art Generally, a stereoscopic camera device for generating a stereoscopic image for stereoscopically viewing an image by utilizing the parallax of the left and right eyes of an observer is shown in FIG.
An optical system 1 including lenses and the like from two different directions.
2 obtained by forming images on the image pickup surfaces of two image pickup devices 102A and 102B, which are CCDs (Charge Coupled Devices) and the like, which are arranged at a predetermined interval, through 01A and 101B, and picked up the images. Image signals 103A and 103B are generated, and the two image signals 10A and 103B are generated.
By fusing 3A and 103B, an image signal 104 capable of forming a stereoscopic image is generated.

[0003]

As described above, the two different
In order to generate the images 103A and 103B taken from the direction by a single image pickup, the optical systems 101A and 1B
01B and the image pickup devices 102A and 102B are used in the image pickup device, two ordinary image pickup devices which are independent of each other are used in parallel.
There is a case where one image pickup device in which 01A, 101B and image pickup devices 102A, 102B are housed in one housing is used. In either case, the image pickup device forms an object image from two different directions. Each requires a dedicated one, and there must be more than one.

Further, the object to be measured is imaged from two different directions via the optical system on the image pickup surfaces of two image pickup elements arranged at a predetermined interval, and the image is picked up. Even in a distance measuring device that measures the distance to a measurement object by the principle of triangulation by detecting the phase difference between two image signals, conventionally, in order to form an image of the measurement object from two different directions. Each requires a dedicated image pickup element, and has the same problems as described above.

By the way, in the solid-state image pickup device represented by CCD or the like, the size of each pixel has been reduced in recent years, and the number of pixels can be increased. The present inventors focused their attention on such a multi-pixel solid-state imaging device,
It was considered that two image signals can be generated at one time by simultaneously receiving incident light from two different directions.

That is, the first object of the present invention is to provide a solid-state image pickup device capable of generating an image signal capable of forming a stereoscopic image from the subject images received at different incident angles by itself. To provide.

A second object of the present invention is to provide a stereoscopic camera device having a simple structure which can easily generate two image signals for displaying a stereoscopic image by one solid-state image pickup device at one time. To provide.

Further, a third object of the present invention is to provide a distance measuring device having a simple structure capable of easily generating two image signals for detecting a phase difference by one image pickup by one solid-state image pickup element. To provide.

[0009]

According to a first aspect of the invention for solving the first problem, a large number of pixels are arranged on the same image pickup surface, and a subject image formed on the image pickup surface is photoelectrically converted. In the solid-state imaging device for generating an image signal, the large number of pixels are divided into two groups, and the light-receiving incident angles of the pixels in each group are different from each other.

According to a second aspect of the present invention, an on-chip microlens is provided for each pixel, and a light-shielding portion for blocking a part of incident light is provided on the surface of the on-chip microlens.
The solid-state image pickup device according to claim 1, wherein the light-shielding portions are arranged differently in each group so that the light-receiving incident angles of the pixels in each group are made different.

According to a third aspect of the present invention, an on-chip microlens is provided for each pixel, and a light-shielding member for blocking a part of incident light is provided between the on-chip microlens and the pixel, and the light-shielding member is provided. 2. The solid-state image pickup device according to claim 1, wherein the light receiving incidence angles of the pixels in the respective groups are made different by making the arrangements of the groups different from each other.

According to a fourth aspect of the present invention, an on-chip microlens is provided for each pixel, and the shape of the on-chip microlens is made different in each group.
The solid-state image pickup device according to claim 1, wherein the light-receiving incident angles of the pixels in each group are different from each other.

According to a fifth aspect of the present invention, for each pixel, a shield that is selectively operable by a microactuator is provided at a position where a part of the incident light is shielded and a position where the incident light is opened, and the shield is provided for shielding the incident light. The solid-state image pickup device according to claim 1, wherein the light-receiving incident angles of the pixels in each group are made different by operating in a position where a part of the pixels is blocked.

According to a sixth aspect of the present invention, one solid-state image pickup device according to any one of the first to fifth aspects is provided with light from the same subject from two different directions with respect to the image pickup surface of the solid-state image pickup device. Two image systems for making incident light are generated, two image signals having different incident angles of light reception are simultaneously generated by the solid-state imaging device, and an image signal for displaying a stereoscopic image is obtained by synthesizing these two image signals. It is a stereoscopic camera device characterized by generating.

According to a seventh aspect of the present invention, there is provided one solid-state image pickup device according to any one of the first to fifth aspects, and light from a measurement object is emitted from two different directions with respect to the image pickup surface of the solid-state image pickup device. The present invention is characterized in that it has two optical systems for making incident light, two solid-state image pickup devices simultaneously generate two image signals with different light-receiving incident angles, and detects the phase difference between these two image signals to perform distance measurement. It is a distance measuring device.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

FIG. 1 is a partial plan view showing an image pickup surface of a solid-state image pickup device according to the present invention, and FIG. 2 is a sectional view taken along line (a)-(a) of FIG.

In the solid-state image pickup device 1, a large number of pixels 3 are two-dimensionally arranged in the XY direction on a substrate 2, and the image pickup surface is constituted by the surfaces of the plural arranged pixels 3.

Each pixel 3 forming the image pickup surface in this way
On-chip microlenses 4 (hereinafter, simply referred to as microlenses 4) are provided on the respective surfaces of, and the light incident on the pixels 3 is efficiently condensed on the light-receiving surface so that the effective aperture ratio is increased. I am trying to improve. A hemispherical lens or a cylindrical lens may be used as the microlens 4.

Each microlens 4 is provided with a light shielding portion 5 over substantially half of its surface in plan view. More specifically, as shown in FIG. 3A, the light incident on the microlens 4 from the light shielding portion 5 side is blocked without reaching the pixel 3, and only the incident light from the side where the light shielding portion 5 is not formed is blocked. Can be made to reach the pixel 3. As a result, each pixel 3 has a microlens 4 having a light shielding portion 5.
The incident angle of received light is regulated by.

The light-shielding portion 5 may be any one capable of shielding a part of visible light from the subject image, and is formed by applying it to the surface of the microlens 4 using, for example, a black pigment or dye. You can

In the solid-state image sensor 1 of the present invention,
In each pixel 3 having such a microlens 4, two groups in which the arrangement of the light shielding portion 5 formed over substantially half of the surface of each microlens 4 is different by 180 degrees, that is, the light shielding portion 5 is seen in a plan view. A group placed on the left side,
It is divided into B group arranged on the right side. Therefore, the respective pixels 3 belonging to the A group and the respective pixels 3 belonging to the B group have mutually different light receiving incident angles.

In the present invention, it is preferable that the two groups A and B are arranged on the image pickup surface substantially evenly over the entire image pickup surface. In this case, the pixels 3 belonging to the same group are arranged in a checkered pattern (FIG. 4 (A)), or vertically or horizontally in one row (FIG. 4 (B), C)).

In the present invention, when each pixel 3 is divided into two groups of A and B, it is preferable that a pixel group consisting of a plurality of adjacent pixels 3 be one unit. Generally, each pixel 3 in the solid-state imaging device 1 for generating a color image has R, G, B color filters (not shown), and as shown in FIG. Although B is arranged almost regularly, it is preferable that one unit is composed of three or more pixels including at least the pixels 3 of the respective colors of R, G, and B. In the example of FIG. 1, four pixel groups of R, G, G, and B (pixels surrounded by a dotted line) that are adjacent to each other in the XY direction constitute one unit, and a pixel group composed of these four groups. Then, one unit in each of the A group and the B group is configured, the light receiving and incident angle of each pixel 3 in the one unit is made the same, and each unit is divided into the A and B groups. The incident angles of light reception are different, and the light receiving incidence angles are arranged in a checkered pattern as shown in FIG.

When the pixels are divided into groups in this way, a plurality of adjacent pixels 3 form one unit, so that, for example, from the electric signals output from the pixel groups of the A group,
It is possible to interpolate the electric signals of the pixels corresponding to the pixel group of the group, and to generate the image signal with less deterioration.

As described above, according to the solid-state image pickup device 1 of the present invention, the image of the object is picked up at different light-receiving incident angles by the pixels 3 which are divided into two groups, A group and B group, which have different light-receiving incident angles. Therefore, it is possible to simultaneously generate two image signals having different incident angles of light reception by imaging once.

FIG. 3B shows another mode of the light shielding portion. The light shielding portion 51 is arranged between the microlens 4 and the pixel 3 and is formed so as to shield almost half of the pixel 3 in a plan view (not shown). Therefore, the light incident from the light blocking portion 51 side through the microlens 4 is transmitted to the pixel 3
The light is blocked without reaching to the pixel 3 and only the incident light from the side not covered by the light blocking portion 51 can reach the pixel 3. As a result, the light receiving incident angle of each pixel 3 is regulated by the light shielding portion 51.

Such a light shielding portion 51 can be formed by using aluminum, tungsten or the like.

FIG. 3C shows another mode for regulating the light receiving incident angle of each pixel 3. Here, the light-shielding portions 5 and 51 are not used, and the microlens 41 whose shape is formed so that only incident light from one direction can reach the pixel 3 is used. That is, the micro lens 41
Has a substantially fan-shaped longitudinal section as shown in the drawing, and is configured to allow only incident light from the curved surface 41a side to reach the pixel 3. Therefore, by arranging such microlenses 41 such that the directions of the curved surfaces 41a are different for each of the groups A and B, the subject images are captured at different light reception incident angles, and light is simultaneously received by one image capturing. It is possible to generate two image signals with different incident angles.

FIG. 3D shows another mode for regulating the light receiving incident angle of each pixel 3. here,
On the surface of the microlens 4, a shield which can be selectively operated by a microactuator at two positions, a shield position where only the incident light from one direction shown by the solid line reaches the pixel 3 and an open position where the chain line shows. 52 is provided and configured. According to this aspect, since the incident light from all directions can be received when the shield 52 is at the open position, it is possible to perform the same image pickup as a normal image pickup element.

As the microactuator, an electrostatic type, a piezo laminated type, a piezo bimorph, an ultrasonic motor, a shape memory alloy, a thermal expansion, a bimetal type, a superconducting type or the like can be used.

The solid-state image pickup device 1 thus constructed
Can be preferably used in a device that needs to generate two image signals, such as a stereoscopic camera device or a distance measuring device.

FIG. 6 is a block diagram for explaining the outline of the stereoscopic camera device 10.

The stereoscopic camera device 10 has one subject 20.
Optical systems 11A and 11B, each of which has a lens or the like for allowing light from the light source to enter from two different directions,
A subject image is formed on the image pickup surface of one solid-state image pickup device 1 via these optical systems 11A and 11B. The optical systems 11A and 11B and the solid-state image sensor 1 are integrally housed in a single housing.

As described above, this solid-state image pickup device 1 divides a large number of pixels into two groups and makes the light receiving and incident angles of the pixels in each group different, so that the light receiving and incident angles of the object image are different. You can take a picture with. Therefore, the light-receiving incident angles on the pixels 3 of each group in the solid-state imaging device 1 are set to the optical systems 11A and 1
By matching the incident optical axes LA and LB of 1B,
The same subject image can be picked up from two different directions by one shot. That is, from this solid-state image pickup device 1, an image signal 12A picked up through the optical system 11A and an image signal 12B picked up through the optical system 11B are simultaneously generated by a single image pickup.

Image signals obtained by capturing incident light from two different directions by the solid-state image pickup device 1 are first separated into left and right image signals in the image separating section 12. Each of the left and right image signals is subjected to predetermined conversion processing in the corresponding two image conversion units 13A and 13B, and the R, G, and B image signals are converted into a luminance signal (Y) suitable for screen display. ) And the color difference signal (C
r, Cb).

It should be noted that the image signal conversion processing is performed by arranging the two image conversion units 13A and 13B in parallel as in the example shown in the figure. It may be executed by time sharing.

The left and right image signals converted in this way are generated as an image signal capable of forming a stereoscopic image by synthesizing them in the image synthesizing section 14. Depends on the display system. For example, if the display device has a vertical stripe pattern, every other pixel is set to 0.
In the case where the polarizing plates of 90 degrees and 90 degrees are provided, as shown in FIG. 7, the combination of the left and right image signals (R signal and L signal) is fitted into every other pixel so as to form a vertical stripe shape. Let go With respect to the image generated in this way, a stereoscopic image can be visually recognized by wearing glasses that allow only rays of 0 degree and 180 degrees to pass therethrough.

FIG. 8 is a block diagram for explaining the outline of the distance measuring device 20 constructed by using only one solid-state image pickup device 1.

The distance measuring device 20 is a single measuring object 200.
Optical systems 21A and 21B, each of which has a lens or the like for allowing light from the light source to enter from two different directions,
An image of the measuring object 200 is formed on the image pickup surface of one solid-state image pickup device 1 via these optical systems 21A and 21B.

The image signal obtained by capturing the incident light from the two different directions by the solid-state image sensor 1 is separated into the left and right image signals by the image separating section 22. Each of the left and right image signals is subjected to a predetermined conversion process in the two image conversion units 23A and 23B corresponding thereto. This image signal conversion processing is performed by two image conversion units 23A and 23B as in the illustrated example.
Instead of performing the above in parallel, the image signals separated into the right and left may be executed by time sharing by only one image conversion unit.

Next, the left and right image signals that have been subjected to the conversion processing are output to the phase difference detecting section 24, where the phase difference between the respective image signals is detected, and the arithmetic processing section 25 is based on the detected values obtained. At, the distance to the measurement object 200 is calculated.

Thus, the solid-state image pickup device 1 according to the present invention
Since it is possible to generate a stereoscopic image and measure the distance to the object to be measured by using only one, it is possible to configure the stereoscopic camera device 10 and the distance measuring device 20 having a simple structure.

[0044]

According to the present invention, there is provided a solid-state image pickup device capable of generating an image signal capable of forming a stereoscopic image from an object image received at different incident angles by itself. be able to.

Further, according to the present invention, there is provided a stereoscopic camera device having a simple structure which can easily generate two image signals for displaying a stereoscopic image by one image pickup by one solid-state image pickup device. be able to.

Further, according to the present invention, there is provided a distance measuring device having a simple structure capable of easily generating two image signals for detecting a phase difference by one image pickup by one solid-state image pickup element. be able to.

[Brief description of drawings]

FIG. 1 is a partial plan view showing an image pickup surface side of a solid-state image pickup element according to the present invention.

FIG. 2 is a sectional view taken along line (a)-(a) of FIG.

3A to 3D are cross-sectional views showing the structure of a solid-state image sensor according to the present invention.

4 (A) to (C) are diagrams showing an example of arrangement of each divided group.

FIG. 5 is a view showing an arrangement example of color filters of a solid-state image sensor according to the present invention.

FIG. 6 is a block diagram showing an outline of a stereoscopic camera device according to the present invention.

FIG. 7 is an explanatory diagram showing a combined sequence of image signals for generating a stereoscopic image.

FIG. 8 is a block diagram showing an outline of a distance measuring device according to the present invention.

FIG. 9 is a diagram illustrating the principle of a conventional stereoscopic camera device.

[Explanation of symbols]

1: Solid-state image sensor 2: substrate 3: Pixel 4: On-chip micro lens 5: Light-shielding part 51: Shading plate 52: Shield 10: Stereoscopic camera device 11A, 11B: Optical system 12: Image separation unit 13A, 13B: Image conversion unit 14: Image composition section 20: Distance measuring device 21A, 21B: Optical system 22: Image separation unit 23A, 23B: Image conversion unit 24: Phase difference detector 25: Arithmetic processing unit

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Claims (7)

[Claims] 1. A solid-state image pickup device in which a large number of pixels are arranged on the same image pickup surface, and a subject image formed on the image pickup surface is photoelectrically converted to generate an image signal. A solid-state image sensor, characterized in that the light receiving and incident angles of the pixels in each group are made different. 2. An on-chip microlens is provided for each pixel, a light-shielding portion that blocks a part of incident light is provided on the surface of the on-chip microlens, and the arrangement of the light-shielding portion is different for each group. 2. The solid-state image sensor according to claim 1, wherein the light receiving incident angles of the pixels in each group are made different from each other. 3. An on-chip microlens is provided for each pixel, a light-shielding member is provided between the on-chip microlens and the pixel to block a part of incident light, and the light-shielding member is arranged in each group. By making them different from each other,
The solid-state imaging device according to claim 1, wherein the light-receiving incident angles of the pixels in each group are different from each other. 4. An on-chip microlens is provided for each pixel, and by making the shape of the on-chip microlens different for each group, the light receiving and incident angles of the pixels in each group are made different. The solid-state image sensor according to claim 1. 5. A shield that can be selectively operated by a microactuator is provided at a position for blocking a part of incident light and an opening position for each pixel, and the shield is provided at a position for blocking a part of the incident light. The solid-state image pickup device according to claim 1, wherein the light-receiving incident angles of the pixels in each group are made different by being operated. 6. The one solid-state image pickup device according to claim 1, and two optical systems that allow light from the same subject to enter the image pickup surface of the solid-state image pickup device from two different directions. And two image signals having different incident angles of light reception are simultaneously generated by the solid-state imaging device, and an image signal for displaying a stereoscopic image is generated by combining these two image signals. 3D camera device. 7. The one solid-state image pickup device according to claim 1, and two optical systems that allow light from a measurement object to enter the image pickup surface of the solid-state image pickup device from two different directions. And a distance measuring device having the above-mentioned solid-state image sensor, which simultaneously generates two image signals having different incident angles of light reception, and detects a phase difference between these two image signals to perform distance measurement.