WO2007125876A1

WO2007125876A1 - Imaging device

Info

Publication number: WO2007125876A1
Application number: PCT/JP2007/058765
Authority: WO
Inventors: Katsumi Imada
Original assignee: Panasonic Corporation
Priority date: 2006-04-24
Filing date: 2007-04-23
Publication date: 2007-11-08
Also published as: JP2009168447A

Abstract

An imaging device (1) including an optical lens array (3) having at least two optical lenses (3a, 3b) with different optical axes; an imaging element (4) having at lest two imaging regions (41, 42) corresponding on a one-to-one basis to the at least two optical lenses; and a field angle restriction member (6) having at least two openings (61, 62) corresponding on a one-to-one basis to the at least two optical lenses and restricting the angles of field of adjacent two optical lenses. The field angle restriction member is shaped such that the angle of field of each of the adjacent two optical lenses is greater on the side of the adjacent optical lens than on the opposite side. This enables distance measurement in a wide range even for an object at a short distance.

Description

Specification

Imaging device

Technical field

The present invention relates to a compound eye type imaging apparatus. In particular, the object by stereo vision with compound eyes

The present invention relates to an imaging device that measures a distance to (subject).

Background art

[0002] Using two imaging optical systems arranged side by side in the horizontal direction or the vertical direction, the front subject is imaged, the parallax between the two obtained images is detected, and the principle of triangulation is used. A binocular ranging system that measures the distance to the subject is used for measuring the distance between vehicles and for the automatic focusing system of cameras. This binocular ranging system is provided with a binocular optical device having a binocular optical system that forms an image of a subject on an image sensor.

As this binocular optical device, there is known a device that forms a subject image on a pair of image sensors arranged in a horizontal direction by a pair of optical lenses arranged in a horizontal direction (patents). Reference 1).

Patent Document 1: Japanese Patent Laid-Open No. 04-043911

Disclosure of the invention

Problems to be solved by the invention

[0004] However, in such a conventional imaging device that measures the distance to the subject, the distance measurement range is extremely narrow when measuring the distance to the subject at a short distance! With niece! There was a problem. This is because only the area where the imaging areas of the two imaging optical systems overlap is an area that can be measured.

[0005] As means for solving this problem, conventionally, efforts have been made to reduce the distance between two imaging optical systems and bring an area where the respective imaging areas overlap closer to the imaging apparatus. The configuration is shown in Figs. 8A and 8B.

[0006] FIG. 8A shows a binocular imaging device in which two imaging optical systems are configured separately and the two imaging optical systems are arranged apart from each other. Fig. 8B shows a binocular imaging device that integrates two imaging optical systems in close proximity. 8A and 8B, the area 11 with the dot pattern is The imaging area of the two imaging optical systems is an overlapping area, and this is the distance measuring area. Reference numeral 20 denotes a region imaged by the first optical lens 3a and the solid-state imaging device 4 at a distance a from the front end of the imaging device. Reference numeral 21 denotes an area that can be measured by stereo vision using two imaging optical systems at a distance a determined by the tip force of the imaging apparatus. Note that the imaging area 20 and the distance measuring area 21 at a distance a from the front end of the imaging apparatus are originally two-dimensional areas extending in a direction perpendicular to the optical axis, but FIGS. 8A and 8B are along the optical axis. These areas are represented as line segments because they are cross-sectional views! RU

As shown in FIG. 8A, the distance measuring area 21 is remarkably narrow with respect to the imaging area 20 at a position separated by the tip force distance a of the imaging apparatus. On the other hand, in the image pickup apparatus of FIG. 8B in which two image pickup optical systems are arranged close to each other, the distance measurement area 21 is narrower than the image pickup area 20, but the distance measurement area 21 is wider than FIG. 8A.

[0008] However, even in the configuration of FIG. 8B, the ratio of the measurable area 21 still occupies the imaging area 20 is small! /, So it is wide in the direction perpendicular to the optical axis at a short distance! In order to measure the subject to be measured, it is necessary to increase the ratio of the distance-measurable area 21 to the imaging area 20. For example, if the distance between the lens centers of the two imaging optical systems is 20 mm and the angle of view (total angle of view) of the two imaging optical systems is 60 °, the first measurement is made at a position about 17 mm away from the tip of the imaging device. A rangeable area 21 appears. Therefore, the distance measurement possible area 21 at a distance from the imaging device of about 17 mm is significantly narrower than the imaging area 20 of each imaging optical system. On the other hand, 95% of the imaging area 20 becomes the distance measuring area 21 at a position where the distance from the imaging apparatus is about 330 mm.

[0009] As described above, in the conventional configuration, since the distance-measurable area at a short distance is small, it is difficult to measure a subject located at a short distance. The present invention has been made to solve such a problem, and an object of the present invention is to provide an imaging apparatus capable of measuring a distance over a wide range even with a short-distance subject.

Means for solving the problem

The imaging apparatus of the present invention has an optical lens array having at least two optical lenses having different optical axes, and an imaging having at least two imaging regions corresponding to the at least two optical lenses in a one-to-one relationship. There is a one-to-one correspondence between the element and the at least two optical lenses. An angle-of-view restricting member that restricts the angle of view of the two optical lenses adjacent to each other. The angle-of-view restriction member has a shape that is larger on the side of the optical lens adjacent to the angle of view of each of the two optical lenses adjacent to each other than on the opposite side.

The invention's effect

[0011] According to the present invention, it is possible to secure a distance measurement area that is almost the same size as the imaging area even at a short distance, and therefore, it is possible to measure a wide distance within a short distance. Is possible.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a schematic configuration of an imaging apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a diagram for explaining the principle of triangulation in the imaging apparatus according to the present invention.

FIG. 3 is a cross-sectional view showing an imaging area and a distance measuring area in a conventional imaging apparatus.

FIG. 4 is a cross-sectional view showing an imaging area and a distance measurement possible area in the imaging apparatus according to Embodiment 1 of the present invention.

FIG. 5A is a cross-sectional view showing a schematic configuration of another imaging apparatus according to Embodiment 1 of the present invention.

FIG. 5B is a plan view of the optical hood of the imaging device shown in FIG. 5A.

FIG. 6A is a cross-sectional view showing a schematic configuration of still another imaging apparatus according to Embodiment 1 of the present invention.

FIG. 6B is a plan view of the optical hood of the image pickup apparatus shown in FIG. 6A.

FIG. 7 is a cross-sectional view showing a schematic configuration of an imaging apparatus according to Embodiment 2 of the present invention.

FIG. 8A is a cross-sectional view showing a schematic configuration of a conventional imaging device.

FIG. 8B is a cross-sectional view showing a schematic configuration of another conventional imaging apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] In the imaging apparatus of the present invention, the angle-of-view restriction member is the optical lens array. In contrast, the optical hood is preferably disposed on the opposite side of the image sensor. As a result, the optical hood that is normally provided in the imaging apparatus also functions as an angle-of-view restriction member, so there is no need to add a new member as the angle-of-view restriction member. Therefore, the configuration is simplified, the number of parts is reduced, and a small imaging device can be provided at low cost.

[0014] In this case, the inclination of the edge of each of the two adjacent openings of the optical hood corresponding to the two adjacent optical lenses is a side force close to the adjacent opening from the opposite side. Is also preferable. Alternatively, the height of each edge of the two adjacent openings of the optical hood corresponding to the two adjacent optical lenses is lower than the side force close to the adjacent opening and the opposite side. It is preferable. Alternatively, each of the two adjacent openings of the optical hood corresponding to the two adjacent optical lenses is decentered with respect to the optical axis of the corresponding optical lens on the side closer to each other. Preferably it is. In any of these, the angle of view of each of the two optical lenses adjacent to each other can be made larger on the side of the adjacent optical lens than on the opposite side with a simple configuration.

In the imaging apparatus of the present invention, it is preferable that the angle-of-view restriction member is a diaphragm plate disposed between the optical lens array and the imaging element. This eliminates the need for the optical feed to function as an angle-of-view restriction member, so that a general-purpose optical hood can be used, and the degree of freedom of design of the optical hood that affects the appearance of the imaging device is increased. improves.

[0016] In this case, each of the two adjacent openings of the diaphragm plate corresponding to the two optical lenses adjacent to each other is on the side away from each other with respect to the optical axis of the corresponding optical lens. It is preferably eccentric. Thereby, the angle of view of each of the two adjacent optical lenses can be made larger on the adjacent optical lens side than on the opposite side with a simple configuration.

[0017] In the imaging apparatus of the present invention, each of the two imaging regions corresponding to the two optical lenses adjacent to each other is deviated from the optical axis of the corresponding optical lens on the side away from each other. It is preferable to be mindful. As a result, the image of the subject in the image pickup area enlarged as a result of the angle of view of the optical lens being enlarged toward the adjacent optical lens can be ensured. Since it is possible to pick up an image, it is easy to measure the distance of an object at a short distance.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0019] (Embodiment 1)

FIG. 1 is a cross-sectional view of the imaging apparatus according to Embodiment 1 of the present invention. In FIG. 1, 1 is an integrated compound-eye imaging device, 2 is a lens barrel, 3 is an optical lens array held by the lens barrel 2, 3a is a first optical lens constituting the optical lens array 3, 3b Is a second optical lens constituting the optical lens array 3, 4 is a solid-state imaging device, 5 is a substrate on which the lens barrel 2 and the solid-state imaging device 4 are mounted, 6 is an optical hood, and 9 is a subject. 10a is the optical axis of the first optical lens 3a, 10b is the optical axis of the second optical lens 3b, and these are parallel to each other. As shown, the axis parallel to the optical axes 10a and 10b is the Z axis, and the axis perpendicular to the Z axis and including the optical axes 10a and 10b is the X axis. On the Z axis, the subject 9 side (upper side of the page in Fig. 1) is the positive side of the Z axis, and in the X axis, the direction side (right side of the page of Fig. 1) from the optical axis 10b to the optical axis 10a is the positive side of the X axis . In the following description, “inner side” refers to the other optical axis side with respect to one optical axis of the pair of optical axes 10a and 10b, and “outer side” refers to one optical axis. The opposite side to the other optical axis.

[0020] The optical hood 6 is disposed closer to the subject 9 than the optical lens array 3, and corresponds to the first and second optical lenses 3a and 3b in a one-to-one correspondence with a pair of independent openings 61 and 62. Is formed. The edge shapes of the pair of openings 61 and 62 are both substantially funnel-shaped (or deformed frustoconical surface), and the slope of the slope of each edge is on the opposite side (inside) to the opposite side. Looser than the side (outside). That is, in the cross-sectional view including the optical axes 10a and 10b (FIG. 1), of the pair of inclined surfaces 61a and 61b formed by the edge of the opening 61 corresponding to the first optical lens 3a, the side closer to the optical axis 10b. The inclination angle of the inclined surface 61a with respect to the optical axis 10a is larger than the inclination angle of the inclined surface 61b far from the optical axis 10b with respect to the optical axis 10a. In the circumferential direction of the edge of the opening 61, the slope of the slope of the edge of the opening 61 continuously changes so as to smoothly connect the slope 61a and the slope 61b. The edge shape of the opening 62 corresponding to the second optical lens 3b is symmetric with the edge shape of the opening 61.

[0021] Further, the height of each edge of the openings 61 and 62 of the optical hood 6 is set on the side close to the adjacent opening.

(Inner side) is lower than the opposite (outer side). Here, the height of the edge of the opening means the optical lens. This is the distance in the Z-axis direction from the laser array 3 to the subject 9 side end of the slope that forms the edge of the aperture. That is, in the cross-sectional view including the optical axes 10a and 10b (FIG. 1), of the pair of inclined surfaces 61a and 61b formed by the edge of the opening 61 corresponding to the first optical lens 3a, the optical axis 10b is on the far side. The end of the slope 61b on the subject 9 side is close to the optical axis 10b, and is closer to the subject 9 than the end of the side slope 61a on the subject 9 side. In the circumferential direction of the edge of the opening 61, the height of the edge of the opening 61 continuously changes so as to smoothly connect the slopes 61a and 61b having different heights. The edge shape of the opening 62 corresponding to the second optical lens 3b is symmetric with the edge shape of the opening 61.

In FIG. 1, broken lines 7a and 8a indicate the angle of view of the first optical lens 3a restricted by the edge shape of the opening 61 of the optical hood 6, and broken lines 7b and 8b indicate the opening 62 of the optical hood 6. The angle of view of the second optical lens 3b regulated by the edge shape is shown. More specifically, the broken line 7a is a line indicating the limit of the imaging region on the negative side of the X axis of the first optical lens 3a, and the broken line 8a is a line on the positive side of the X axis of the first optical lens 3a. It is a line which shows the limit of an imaging region. The broken line 7b is a line indicating the limit of the imaging region on the negative side of the X axis of the second optical lens 3b, and the broken line 8b is the limit of the imaging region on the positive side of the X axis of the second optical lens 3b. It is a line which shows.

[0023] Light rays from the subject 9 existing in the area surrounded by the broken line 7a and the broken line 8a are collected by the first optical lens 3a, and are formed as a subject image in the first imaging area 41 on the image sensor 4. Image. In the cross-sectional view of FIG. 1 along the optical axes 10a and 10b, the image of the subject located on the positive side of the X axis (the broken line 8a side) with respect to the optical axis 10a is reflected on the optical axis 10a on the image sensor 4. On the other hand, the image is formed on the imaging area 4a on the negative side of the X axis. In addition, the image of the subject located on the negative side of the X axis (the broken line 7a side) with respect to the optical axis 10a is on the imaging region 4c on the positive side of the X axis with respect to the optical axis 10a on the image sensor 4. Is imaged.

Similarly, the light rays from the subject 9 existing in the area surrounded by the broken lines 7b and 8b are collected by the second optical lens 3b, and are collected in the second imaging area 42 on the image sensor 4. It forms as an image. In the cross-sectional view of FIG. 1 along the optical axes 10a and 10b, the image of the subject located on the negative side of the X axis (the broken line 7b side) with respect to the optical axis 10b is reflected on the optical axis 10b on the image sensor 4. On the other hand, the image is formed on the imaging region 4b on the positive side of the X axis. In addition, the image of the subject located on the positive side of the X axis (the broken line 8b side) with respect to the optical axis 10b is the X axis relative to the optical axis 10b on the image sensor 4. The image is formed on the imaging region 4d on the negative side of the image.

The two subject images formed on the image sensor 4 by the first and second optical lenses 3a and 3b are photoelectrically converted and output as two pieces of image information. The two pieces of output image information are transferred to the subsequent image processing unit (not shown) as electrical signals. In the image processing unit, each of the two images is divided into a plurality of blocks, and pattern matching is performed between the two images to extract a parallax distribution on the two images. Based on the parallax obtained, the principle of triangulation is used to calculate the distance to the desired subject.

The principle of distance measurement in the compound eye type imaging apparatus will be described with reference to FIG. In FIG. 2, 15 is a subject placed at a finite distance, 16a is a subject image formed on the solid-state imaging element 4 by the first optical lens 3a, and 16b is solid-state imaging by the second optical lens 3b. 10a is the optical axis of the first optical lens 3a, 10b is the optical axis of the second optical lens 3b, and 18a is the first optical lens on the solid-state imaging device 4. The imaging center of 3a, 18b is the imaging center of the second optical lens 3b on the solid-state imaging device 4.

The light rays emitted from the subject 15 at a finite distance on the optical axis 10a of the first optical lens 3a are collected by the first optical lens 3a and formed on the solid-state imaging device 4 as an image 16a. Similarly, the light beam emitted from the subject 15 is collected by the second optical lens 3b, and forms an image 16b on the solid-state imaging device 4. Since the subject 15 is located away from the optical axis 10b of the second optical lens 3b, the image 16b is formed at a position separated from the imaging center 18b on the solid-state imaging device 4 by the parallax Δ. Here, if the subject distance is z, the baseline length that is the distance between the imaging centers of the two optical lenses 3a and 3b is B, the focal length of the optical lenses 3a and 3b is f, and the amount of parallax is Δ, The following approximate expression (1) holds.

[0028] ζ = Β · ί / Δ · · · (1)

It is possible to calculate the distance ζ to the subject 15 by measuring the parallax amount Δ according to Equation (1).

[0029] In the conventional imaging device shown in Figs. 8 and 8, it is necessary to move the imaging device far from the subject in order to improve the ratio of the distance measuring area 21 to the imaging area 20. For example, as described above, in order to make the ratio of the distance measuring area 21 to the imaging area 20 95%, the conventional imaging apparatus shown in FIG. When the total angle of view of the image optical system is 60 °), the tip force of the hood needs to be about 33 Omm.

However, in the imaging apparatus of the present invention shown in FIG. 1, the slope of the edge of each of the openings 61 and 62 of the optical hood 6 is opposite to the side (inner side) close to the adjacent opening. Looser than the side (outside). Furthermore, the height of each edge of the openings 61 and 62 of the optical hood 6 is lower on the side close to the adjacent opening (inner side) than on the opposite side (outer side). Accordingly, in the cross-sectional view including the optical axes 10a and 10b, the field angle of the first optical lens 3a is enlarged on the second optical lens 3b side. That is, the imaging region that can be imaged by the first optical lens 3a is enlarged toward the second optical lens 3b. Similarly, the angle of view of the second optical lens 3b is also enlarged on the first optical lens 3a side. That is, the imaging region that can be imaged by the second optical lens 3b is also enlarged toward the first optical lens 3a.

[0031] In this manner, the angle of view of each of the pair of optical lenses 3a and 3b that forms two images used when the image processing unit (not shown) performs the parallax distribution extraction process is set inward. By enlarging, it is possible to expand the range that can be measured for a subject at a short distance. As a result, it is possible to provide an image pickup apparatus that can also measure a subject at a short distance. For example, the angle of view of each of the pair of optical lenses 3a and 3b is set to the inside 15 by the optical hood 6 shown in FIG. When zoomed in, the subject distance that makes the ratio of the measurable area to the imaging area 95% is about 45 mm, and the position in the optical axis direction that can be measured over almost the entire area of the imaging area is significantly imaged compared to the conventional configuration. Can be close to the device.

[0032] If the angle of view of each of the pair of optical lenses 3a and 3b is simply enlarged inward, the optical hood 6 is formed with one slot-like opening common to the pair of optical lenses 3a and 3b. All you need is enough. However, such a configuration causes the following problems. First, light enters from a region between the optical lens 3a and the optical lens 3b of the lens array 3. When this light is incident on the image sensor 4, the image quality of the captured image is degraded, and the ranging accuracy is lowered. Second, the angle of view on the inside is enlarged more than necessary, so light enters the optical lens from the adjacent optical lens side at a large incident angle. When this light is reflected by the inner wall surface of the lens barrel 2 of the image pickup apparatus 1 and enters the image pickup device 4, the image quality of the picked-up image is deteriorated and the ranging accuracy is lowered. Therefore, in the present embodiment, the optical hood 6 has two optical lenses 3a, Two independent openings 61 and 62 force S are provided corresponding to 3b on a one-to-one basis.

FIG. 3 is a cross-sectional view showing a relationship between an imaging area and a distance-measurable area of a conventional imaging device, and FIG. 4 shows an imaging area and a distance-measurable area in the imaging device according to the first embodiment. It is sectional drawing which shows a relationship. The relationship between the imaging area and the distance-measurable area is described below with reference to Figs. 3 and 4, parts having the same functions as those in FIG. 1 are given the same numbers.

3 is different from FIG. 1 in the slopes of the substantially funnel-shaped end edges of the openings 61 and 62 formed in the optical feed 6 disposed on the object side with respect to the lens array 3. The inclination is constant over the entire circumference of the opening, and the height of the edge of each of the openings 61 and 62 is constant over the entire circumference of the opening.

[0035] The imaging area that can be imaged by the first optical lens 3a and the solid-state imaging device 4 includes a broken line 7a indicating the limit of the imaging area on the negative side of the X axis of the first optical lens 3a and the first optical lens. This is an area surrounded by a broken line 8a indicating the limit of the imaging area on the positive side of the X axis of 3a. In addition, the imaging area that can be imaged by the second optical lens 3b and the solid-state imaging device 4 is the broken line 7b indicating the limit of the imaging area on the negative side of the X axis of the second optical lens 3b and the second optical lens 3b. This is an area surrounded by a broken line 8b indicating the limit of the imaging area on the positive side of the X axis. In order to perform distance measurement using the principle of triangulation, it is necessary to image a common subject using both optical lenses 3a and 3b, so the distance measurement possible area overlaps the imaging areas of optical lenses 3a and 3b. This is the area 11 with the dot pattern. In FIG. 3, the area that can be measured is compared with the imaging area of the first optical lens 3a surrounded by the broken lines 7a and 8a and the imaging area of the second optical lens 3b surrounded by the broken lines 7b and 8b. 11 is narrow. This is the reason why it is not possible to secure a sufficient distance measurement area (angle of view) for short-distance subjects.

On the other hand, also in FIG. 4, the imaging area that can be imaged by the first optical lens 3a and the solid-state imaging device 4 is a broken line 7a indicating the limit of the imaging area on the negative side of the X axis of the first optical lens 3a. And a broken line 8a indicating the limit of the imaging region on the positive side of the X axis of the first optical lens 3a. The imaging area that can be imaged by the second optical lens 3b and the solid-state imaging device 4 includes the broken line 7b indicating the limit of the imaging area on the negative side of the X axis of the second optical lens 3b, and the second optical lens 3b. This is an area surrounded by a broken line 8b indicating the limit of the imaging area on the positive side of the X axis. Fig 4 Even in this configuration, in order to perform distance measurement using the principle of triangulation, it is necessary to image a common subject using both optical lenses 3a and 3b. , 3b is an area 12 with a dot pattern that overlaps the imaging area.

[0037] Comparing the distance measuring area 11 of the conventional imaging device shown in FIG. 3 with the distance measuring area 12 of the imaging device of the present invention shown in FIG. 4, the latter is clearly wider. In particular, it is enlarged in the direction perpendicular to the azimuth axis of the range-measurable area force in the immediate vicinity of the imaging device. In the present invention, this is because the slope of the substantially funnel-shaped edge of each of the openings 61 and 62 formed in the optical hood 6 is made gentler on the inside than on the outside, and each end of each of the openings 61 and 62 is formed. This is because the angle of view inside the optical lenses 3a and 3b indicated by broken lines 7a and 8b is enlarged by making the edge height lower on the inside than on the outside. As a result, the present invention can secure a sufficiently wide imaging area and a range-measurable area even for a subject close to the imaging device, and can measure a subject at a short distance with high accuracy. Can be far away.

[0038] In the above-described embodiment shown in FIG. 1, the slopes of the respective edges of the openings 61 and 62 formed in the optical hood 6 are gently inclined on the inside, and the openings 61 and 62 are respectively Although the angle of view inside each of the optical lenses 3a and 3b was enlarged by reducing the height of the edge on the inside, the present invention is not limited to this. In other words, if the angle of view inside each of the pair of optical lenses 3a and 3b used for distance measurement can be enlarged, there is no limitation on the specific configuration for realizing this, and in that case as well, The same effect can be obtained.

FIG. 5A is a cross-sectional view showing a schematic configuration of another imaging apparatus 1 of the present invention, and FIG. 5B is a plan view of the optical hood 6 of the imaging apparatus 1. 5A and 5B, parts corresponding to those in FIG. 1 are denoted by the same reference numerals. The imaging device shown in FIGS. 5A and 5B differs from the imaging device shown in FIG. 1 in the following two points.

First, in FIGS. 5A and 5B, the height of each edge of the openings 61 and 62 formed in the optical hood 6 is constant over the entire circumference of the opening. However, the slope of the substantially funnel-shaped edge of each of the openings 61 and 62 is gentler on the inner side than on the outer side, which is the same as FIG. As a result, as shown in FIG. 5B, the upper ends 6 lc and 62 c of the edges of the openings 61 and 62 of the optical hood 6 have an elliptical shape decentered with respect to the optical axis of the optical lens. Even in such a configuration, as shown in FIG. 5A, the angle of view inside the optical lenses 3a and 3b indicated by broken lines 7a and 8b is shown. As shown in Fig. 1, it is possible to measure a close object.

Second, in FIGS. 5A and 5B, there is a light shielding wall 13 for separating the optical path of the light that has passed through the first optical lens 3a and the optical path of the light that has passed through the second optical lens 3b. Is provided. The light shielding wall 13 prevents the incident light from entering the imaging region corresponding to the other optical lens on the solid-state image sensor 4 that has passed through one of the optical lenses 3a and 3b. As a result, unnecessary light does not enter the imaging region, so that the quality of the captured image is improved and the ranging accuracy is improved. Further, in the present invention, since the outside angle of view of the optical lenses 3a and 3b is smaller than the inside angle of view, the possibility that the light passing through the optical lens is directly incident on the light shielding wall 13 is low. Therefore, the provision of the light shielding wall 13 hardly causes a problem that the image quality of the captured image is deteriorated due to the reflected light from the light shielding wall 13 entering the imaging region.

FIG. 6A is a cross-sectional view showing a schematic configuration of still another imaging apparatus 1 of the present invention, and FIG. 6B is a plan view of the optical hood 6 of the imaging apparatus 1. 6A and 6B, members corresponding to those in FIG. 1 are denoted by the same reference numerals. The imaging device shown in FIGS. 6A and 6B differs from the imaging device shown in FIG. 1 in the following two points.

[0043] First, in FIGS. 6A and 6B, the inclination of the slope of the substantially funnel-shaped edge of each of the openings 61 and 62 formed in the optical hood 6 is constant over the entire circumference of the opening. As shown in FIG. 6B, the upper ends 61c and 62c of the edges of the openings 61 and 62 of the optical hood 6 interfere with each other. The height (ridgeline) of the ridge 6c formed by this interference is lower than the rest of the edges of the openings 61 and 62. That is, the height of each edge of the openings 61 and 62 of the optical hood 6 is lower on the inner side than on the outer side. Therefore, for example, the maximum incident angle of light that can be incident on the center of the first optical lens 3a defined by the upper end 61c of the edge of the opening 61 is such that the second optical lens 3b side (inner side) Larger than the opposite side (outside) of lens 3b. In addition, it is possible to form an image on the image pickup element 4 with light incident at a larger incident angle than the inner force. The same applies to the second optical lens 3b. Therefore, even in such a configuration, as shown in FIG. 6A, the angle of view inside the optical lenses 3a and 3b indicated by the broken lines 7a and 8b is expanded, and a subject at a short distance is measured as in FIG. Can be far away.

Second, in FIGS. 6A and 6B, the optical path of the light that has passed through the first optical lens 3a and the second A light shielding wall 13 is provided to separate the optical path of the light that has passed through the optical lens 3b. This is the same as FIGS. 5A and 5B, and the same effect as described in FIGS. 5A and 5B can be obtained.

[0045] The openings 61 and 62 formed in the optical hood 6 are respectively inward with respect to the optical axes 10a and 10b of the corresponding optical lenses 6a and 6b (that is, the openings 61 and 62 are close to each other). It may be eccentric. This also makes it possible to enlarge the angle of view inside each of the optical lenses 3a and 3b. In this case, if the slope of the edge of each of the openings 61 and 62 formed in the optical hood 6 is made gentler on the inside and the height of each edge of Z or the openings 61 and 62 is made smaller on the inside, It is preferable because the angle of view inside each of the optical lenses 3a and 3b can be further enlarged.

In the above description, the force showing an example in which the edge shapes of the openings 61 and 62 formed in the optical hood 6 are substantially funnels. The present invention is not limited to this. As long as the angle of view inside each of the pair of optical lenses 3a and 3b can be enlarged, the edge shapes of the openings 61 and 62 may be substantially cylindrical surfaces, for example.

[0047] (Embodiment 2)

In the first embodiment, the optical hood 6 disposed on the subject side with respect to the lens array 1 has been shown as an example of functioning as an angle-of-view restriction member for restricting the angle of view of the optical lenses 3a and 3b. In the second embodiment, an imaging apparatus will be described in which a diaphragm plate 14 that functions as an angle-of-view restriction member that restricts the angle of view of the optical lenses 3a and 3b is provided on the imaging element 4 side with respect to the lens array 1.

FIG. 7 is a cross-sectional view showing a schematic configuration of the imaging apparatus according to Embodiment 2 of the present invention.

In FIG. 7, parts having the same functions as those in FIGS. 1 and 4 are given the same numbers. In the image pickup apparatus of FIG. 7, a diaphragm plate 14 is provided between the lens array 1 and the image pickup device 4. The diaphragm plate 14 is formed with a pair of independent openings 14a and 14b corresponding to the first and second optical lenses 3a and 3b on a one-to-one basis. The angle of view of the first optical lens 3a indicated by broken lines 7a and 8a is regulated by the edge shape of the opening 14a of the diaphragm plate 14, and the angle of view of the second optical lens 3b indicated by broken lines 7b and 8b is Regulated by the edge shape of the opening 14b of the plate 14

[0049] The pair of apertures 14a and 14b are arranged with respect to the optical axes 10a and 10b of the corresponding optical lenses 6a and 6b. Each is eccentric (ie, the openings 14a, 14b are separated from each other). This enlarges the angle of view inside each of the optical lenses 3a and 3b. Therefore, in the second embodiment, as in the first embodiment, the distance measuring area 12 of the image pickup apparatus can be enlarged, and it is close to the image pickup apparatus! Ranging is possible over a range.

[0050] According to the first and second embodiments, the angle of view inside each of the optical lenses 3a and 3b is enlarged. Therefore, out of the imaging areas 4a and 4c constituting the first imaging area 41 where the light beam that has passed through the first optical lens 3a forms an image, the imaging area 4c outside the optical axis 10a is the imaging area 4a inside. It is preferable that it is enlarged. Similarly, of the imaging areas 4b and 4d constituting the second imaging area 42 where the light beam that has passed through the second optical lens 3b forms an image, the outer imaging area 4d with respect to the optical axis 10b is the inner imaging area. It is preferable that the magnification is larger than 4b. In this way, the first and second imaging regions 41 and 42 are respectively eccentric with respect to the optical axes 10a and 10b on the outside (that is, the first and second imaging regions 41 and 42 are separated from each other). By securing a wider imaging area on the outer side than the inner side with respect to the optical axis, it is possible to image a subject within the enlarged inner angle of view. Can be realized.

[0051] The embodiments described above are intended to clarify the technical contents of the present invention, and the present invention should be construed as being limited to such specific examples. However, various modifications may be made within the spirit and scope of the invention described in the claims, and the present invention should be interpreted broadly.

Industrial applicability

[0052] The field of use of the imaging device according to the present invention is not particularly limited, but can measure a short-distance subject in a wide range, so that it can be used as an imaging device for a mopile device, a surveillance camera, a vehicle, or the like. Useful.

Claims

The scope of the claims

[1] An optical lens array having at least two optical lenses having optical axes different from each other; an imaging device having at least two imaging areas corresponding to the at least two optical lenses on a one-to-one basis;

An angle-of-view restriction member that has at least two openings corresponding to the at least two optical lenses in a one-to-one relationship and restricts the angle of view of the two adjacent optical lenses;

With

The angle-of-view restriction member is configured so that the angle of view of each of the two optical lenses adjacent to each other is the same.

An image pickup apparatus having a shape that is larger on the side of the adjacent optical lens than on the opposite side.

[2] The imaging device according to [1], wherein the angle-of-view restriction member is an optical hood disposed on a side opposite to the imaging element with respect to the optical lens array.

[3] The optical hoods corresponding to the two adjacent optical lenses are adjacent to each other.

3. The imaging device according to claim 2, wherein the inclination of the edge of each of the two openings is gentler on the side closer to the adjacent opening than on the opposite side.

[4] The optical hoods corresponding to the two adjacent optical lenses are adjacent to each other.

3. The imaging apparatus according to claim 2, wherein the height of the edge of each of the two openings is lower on the side close to the adjacent opening than on the opposite side.

[5] The optical hoods corresponding to the two adjacent optical lenses are adjacent to each other.

3. The imaging apparatus according to claim 2, wherein each of the two openings is decentered with respect to the optical axis of the corresponding optical lens on the side approaching each other.

6. The imaging apparatus according to claim 1, wherein the angle-of-view restriction member is an aperture plate disposed between the optical lens array and the imaging element.

[7] Each of the two adjacent openings of the diaphragm plate corresponding to the two adjacent optical lenses is eccentric to the optical axis of the corresponding optical lens on the side away from each other! The imaging device according to claim 6.

[8] Each of the two imaging regions corresponding to the two optical lenses adjacent to each other is decentered with respect to the optical axis of the corresponding optical lens on a side away from each other. Item 2. The imaging device according to Item 1.