JP4734873B2 - Wide-angle imaging device - Google Patents

Description

The present invention relates to a wide- angle imaging device that captures a wide-angle image . Specifically, a combination of a pair of semi-conical reflecting surfaces and a columnar concave curved reflecting surface can capture an image without image distortion from wide-angle incident light.

  FIG. 15 is an explanatory view showing a conventional wide-angle imaging device. A conventional wide-angle imaging device 51 includes a conical reflecting mirror 52 and a camera unit 53. The camera unit 53 includes, for example, a pinhole 54 for focusing and a two-dimensional image sensor 55.

  In addition, a camera processing unit 56 and a conversion processing unit 57 are provided to process image data captured by the two-dimensional image sensor 55.

  The conventional wide-angle imaging device 51 captures the reflected light from the conical reflecting mirror 52 with the two-dimensional image sensor 55 of the camera unit 53. For this reason, the two-dimensional image sensor 55 captures a circular image.

  The image data of the two-dimensional image sensor 55 is processed by the camera processing unit 56, and a circular image is output. The conversion processing unit 57 performs a coordinate conversion process in which the angle and the distance from the center are converted into a square image with the circle center of the circular video as a reference. Thereby, a square image is obtained from the circular image.

  A wide-angle imaging device has also been proposed in which a truncated cone-shaped reflecting mirror and a parabolic reflecting mirror are combined so that the entire circumferential direction can be imaged (see, for example, Patent Document 1).

JP 2002-244236 A

  Although the imaging range of the two-dimensional image sensor is a quadrangle, a circular image is captured by the two-dimensional image sensor in a configuration using a conical reflector. The same applies to the case where light is collected using a parabolic mirror. As a result, a light receiving element that is not used in the two-dimensional image sensor is generated, and the use efficiency is lowered.

  Further, a portion near the circle center of the circular video becomes a small image, and is converted into a rough image by the conversion processing from the circular video to the square video. In order to balance the roughness of the entire image, the converted rectangular image balances the image by reducing the definition of the converted image portion corresponding to the portion far from the center of the circle.

  As described above, the conventional wide-angle imaging device using the conical reflector has a problem that the image definition is low. Further, since an image conversion processing unit is necessary, there is a problem that the price is high.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a wide-angle imaging device that can capture a wide angle with a simple configuration and does not require conversion processing of the captured image.

In order to solve the above-described problem, the wide-angle imaging device according to the present invention cuts a right cone by a plane parallel to the bottom surface, removes a portion including the apex, and further cuts by a surface including an axis perpendicular to the bottom surface. A first reflecting surface having the same shape as the curved surface forming one of the divided side surfaces, and a pinhole, and having the same shape as the first reflecting surface; A cutting surface including an axis perpendicular to the bottom surface and the axis coincide with each other, and the second cone is disposed below the first reflecting surface so that the side corresponding to the bottom surface of the right cone faces the first reflecting surface. Cutting that includes an axis perpendicular to the bottom surface, assuming an elliptical cylinder surface where the reflecting surface and the axis perpendicular to the bottom surface pass through one focal point and the pinhole position coincides with the other focal point Of the two curved surfaces obtained by cutting on the surface, the same shape as the smaller curved surface A third reflecting surface and an imaging means, and the incident light is reflected on the first and second reflecting surfaces in order and is incident on the third reflecting surface, and reflected light from the third reflecting surface. Is condensed in a pinhole and incident on the imaging means .

In the wide-angle imaging device according to the present invention, light from the outside enters the first reflecting surface. The first reflecting surface is cut by cutting the right cone with a plane parallel to the bottom surface to remove the portion including the apex, and further cutting with a surface including the axis perpendicular to the bottom surface to be divided into two symmetrical portions, It has the same shape as the curved surface forming one of the divided side surfaces, receives incident light in a range of approximately 180 degrees in the horizontal direction, and reflects it to the second reflecting surface.

The second reflecting surface, the incident light reflected by the first reflecting surface causes incident on the third reflective surface as a horizontal direction of the emitted light by the reflecting surface having the same shape as the first reflecting surface. The third reflecting surface is a small one of two curved surfaces obtained by cutting the incident light reflected by the second reflecting surface with a cut surface including an axis perpendicular to the bottom surface when assuming an elliptic cylinder surface. The light is condensed on the reflecting surface having the same shape as the curved surface on the side to be incident on the condensing means, focused on the condensing means, and incident on the imaging means.

  According to the wide-angle imaging device of the present invention, horizontal wide-angle incident light is narrowed to a fixed viewing angle and incident on the imaging means by a pair of semi-conical reflecting surfaces and columnar concave curved reflecting surfaces. Accordingly, an optically square image can be taken, an image distortion correction processing unit by image processing is unnecessary, and the product cost can be reduced.

  In addition, when an image is incident on the imaging unit with a rectangular field of view, the effective utilization rate of the pixels of the imaging unit is increased, and an image with high resolution can be obtained.

Embodiments of a wide-angle imaging device of the present invention will be described below with reference to the drawings.

<Configuration of wide-angle imaging device>
1 to 3 show an example of the configuration of the wide-angle imaging device 1a according to the first embodiment. FIG. 1 is a perspective view, FIG. 2 is a plan view, and FIG. 3 is an XZ plane sectional view. FIG. 1 schematically illustrates an optical system of the wide-angle imaging device 1a.

The wide-angle imaging device 1a according to the first embodiment includes an optical body 2a and a two-dimensional image sensor 3. First, the configuration of the optical body 2a will be described as an embodiment of the optical device. The optical body 2a includes an upper semiconical reflecting mirror 4 and a lower semiconical reflecting mirror 5 which are arranged vertically opposite to each other, and a lower half cone. A reflecting mirror 6 is provided in front of the reflecting mirror 5.

The upper half-cone reflector 4 constituting the first half-cone reflector has a shape in which a truncated cone is divided in half, and a concave half-cone reflection surface 4a is formed on the inner surface. The lower half-cone reflector 5 constituting the second half-cone reflector has a shape in which the truncated cone is divided in half, like the upper half-cone reflector 4, and a concave half-cone reflector 5a is formed on the inner surface. .

  The upper half-cone reflector 4 and the lower half-cone reflector 5 include an axis passing through the center of the arc R1 constituting the half-cone reflector 4a of the upper half-cone reflector 4, and the half-cone reflector of the lower half-cone reflector 5. The axes passing through the center of the arc R1 constituting 5a are aligned to face each other vertically. Here, the central axis of the upper half-cone reflector 4 and the lower half-cone reflector 5 is taken as the Z-axis. Moreover, arc R1 in FIG. 2 is an arc in the lower collar part of the semiconical reflecting surface 4a and the upper collar part of the semiconical reflecting surface 5a.

  The semiconical reflecting surface 4a of the upper semiconical reflecting mirror 4 and the semiconical reflecting surface 5a of the lower semiconical reflecting mirror 5 are configured at an angle of 45 degrees with respect to the Z axis as shown in FIG. The semiconical reflecting surface 4a and the semiconical reflecting surface 5a face vertically.

The reflecting mirror 6 constituting the curved reflecting mirror is provided on the front surface facing the semiconical reflecting surface 5a in the horizontal direction. Reflecting mirror 6, in the horizontal direction is a concave surface structure shape composed of part of an ellipse R2, having a first focal point 6a and the second focal point 6b.

The reflecting mirror 6 is located on the Z-axis where the first focal point 6 a coincides with the central axes of the upper and lower half-cone reflecting mirrors 4 and 5, and the second focal point 6 b is the lower half-conical reflecting mirror 5. A curvature or the like is set so as to be positioned on the semiconical reflecting surface 5a.

In the optical body 2a, an incident window 7 is formed on a surface facing the semiconical reflecting surface 4a of the upper semiconical reflecting mirror 4 in the horizontal direction. In addition, a pinhole 8 as a condensing means is formed at a position corresponding to the second focal point 6 b of the reflecting mirror 6 on the semiconical reflecting surface 5 a of the lower semiconical reflecting mirror 5.

The two-dimensional image sensor 3 constituting the imaging means is a CCD (Charge Coupled Device) image sensor, for example, and is provided at a position where light reflected by the reflecting mirror 6 and passed through the pinhole 8 of the lower semiconical reflecting mirror 5 enters. It is done.

  Here, an axis passing through the pinhole 8 and orthogonal to the Z axis is defined as the X axis, an axis passing through the intersection of the X axis and the Z axis, and an axis orthogonal to the X axis and the Z axis is defined as the Y axis.

  FIG. 4 is a control block diagram illustrating an example of a control system of the wide-angle imaging device 1a. In the wide-angle imaging device 1 a, the two-dimensional image sensor 3 is connected to the camera processing unit 21, and an image is acquired from data captured by the two-dimensional image sensor 3.

Here, since the wide-angle imaging device 1a of this example obtains an optically square image by the optical body 2a as will be described later, an image distortion correction processing unit is not required.

<Operation of wide-angle imaging device>
Next, the operation of the wide-angle imaging device 1a according to the first embodiment will be described. 5A and 5B show an example of the optical path in the horizontal direction of light incident on the wide-angle imaging device 1a. FIG. 5A is a perspective view and FIG. 5B is an XY plane cross-sectional view.

  Incident light α from a horizontal direction perpendicular to the Z axis passes through the Z axis which is the center of the upper half cone reflector 4 from the incident window 7 and enters the upper half cone reflector 4. As shown by (1) in FIG. 5, the incident light α to the upper half cone reflector 4 is reflected by the half cone reflector 4a and turned in the direction along the Z axis, so that the lower half cone reflector is changed. 5 is incident.

Incident light α from the direction along the Z-axis to the lower half-cone reflecting mirror 5 is reflected by the half-cone reflecting surface 5a in the direction along the XY plane as shown by (2) in FIG. The direction is changed, and the light enters the reflecting mirror 6 through the Z axis which is the center of the lower semiconical reflecting mirror 5.

Thus, the incident light α passing through the central axis (Z axis) of the upper semiconical reflecting mirror 4 is sequentially reflected by the semiconical reflecting surfaces 4a and 5a, and the central axis (Z axis) of the lower semiconical reflecting mirror 5 is reflected. The light passes through and enters the reflecting mirror 6 .

As described above, the reflecting mirror 6 has a columnar concave curved surface formed of a part of the ellipse R2 in the horizontal direction , the first focal point 6a is located on the Z axis, and the second focal point 6b is the lower half. It is located on the semi-conical reflecting surface 5 a of the conical reflecting mirror 5.

Thus, the incident light α reflected by the semi-conical reflecting surface 5a of the lower half-cone reflector 5 passes through the first focal point 6a of the Z-axis, i.e. elliptical R2 as shown in FIG. 5 (3), reflector 6 is incident.

The incident light α incident on the reflecting mirror 6 through the first focal point 6a is reflected by the reflecting mirror 6 and gathers at the second focal point 6b.

Since the second focus 6b is provided with a pinhole 8, the incident light α reflected by the reflecting mirror 6 passes through the pinhole 8 and forms an image on the two-dimensional image sensor 3 as shown in FIG. 5 (5). Image.

Here, incident light from the front surface of the entrance window 7 is reflected by the semiconical reflecting surface 4a of the upper semiconical reflecting mirror 4, but the central portion of the semiconical reflecting surface 5a of the lower semiconical reflecting mirror 5 is placed at the center of the camera. Since the pinhole 8 corresponding to the focal point is formed , light is not reflected from this portion, and therefore light from this portion does not enter the reflecting mirror 6 .

  For this reason, as shown in FIG. 4, an unimaged portion Q corresponding to the focal portion is generated at the center of the captured video P. However, since the unimaged portion Q is a sufficiently small area, it is not visually recognized and does not cause a problem.

  6A and 6B show an example of the optical path in the horizontal direction of light incident on the wide-angle imaging device 1a from a wide angle. FIG. 6A is a perspective view and FIG. 6B is an XY plane cross-sectional view. Incident light β from a wide angle in the horizontal direction perpendicular to the Z axis enters the upper semiconical reflecting mirror 4 from the incident window 7 through the Z axis. Incident light β from the wide angle to the upper semiconical reflecting mirror 4 is reflected near the end of the semiconical reflecting surface 4a, changes its direction in the direction along the Z axis, and enters the lower semiconical reflecting mirror 5. .

Incident light β from the direction along the Z-axis to the lower semi-conical reflecting mirror 5 is reflected by the semi-conical reflecting surface 5a and redirected in the direction along the XY plane, passing through the Z-axis and reflecting mirror. 6 is incident.

In this way, the incident light β from a wide angle passing through the central axis (Z axis) of the upper semiconical reflecting mirror 4 is also reversed in direction at the semiconical reflecting surfaces 4a and 5a, and the central axis ( It enters the reflecting mirror 6 through the Z axis).

Since the reflecting mirror 6 has the first focal point 6a located on the Z axis, the incident light β reflected by the semiconical reflecting surface 5a of the lower semiconical reflecting mirror 5 is the first focal point 6a of the Z axis, that is, the ellipse R2 . , And enters the vicinity of the end of the reflecting mirror 6 .

Light incident to the first focal point 6a as the reflecting mirror 6, regardless of the reflecting position on the reflecting mirror 6, collects in the second focal point 6b. Thus, the incident light β reflected near the end of the reflecting mirror 6 also passes through the pinhole 8 and forms an image on the two-dimensional image sensor 3.

FIG. 7 is a side sectional view showing an example of an optical path in the vertical direction of light incident on the wide-angle imaging device 1a. Incident light γ inclined within a predetermined angle with respect to the horizontal direction enters the upper half cone reflector 4 from the entrance window 7, and the half cone reflector 4 a and the lower half cone reflector 5 of the upper half cone reflector 4. And is incident on the reflecting mirror 6 while being inclined with respect to the horizontal direction.

Since the vertical direction of the reflecting mirror 6 is a plane, the light incident on the reflecting mirror 6 while being inclined with respect to the horizontal direction is reflected at an emission angle corresponding to the incident angle in the same manner as in the normal plane reflection, and the pinhole 8 And enters the two-dimensional image sensor 3.

As described above, in the wide-angle imaging device 1a of the first embodiment, the upper half-cone reflector 4 of the optical body 2a receives incident light from a wide angle in the horizontal direction, and the upper half-cone reflector 4 and the lower half-cone are received. The light that is sequentially reflected from the reflecting mirror 5 is incident on the reflecting mirror 6, and the reflected light from the reflecting mirror 6 is converted into horizontal radiation light that passes through the first focal point 6 a of the ellipse R 2 , thereby reflecting the reflecting mirror 6. The reflected light from the light is condensed on the two-dimensional image sensor 3 through the pinhole 8 .

  As a result, an image with an expanded visual field in the horizontal direction is incident on the two-dimensional image sensor 3. In this example, a rectangular image having a visual field of about 180 degrees in the horizontal direction and about 60 degrees in the vertical direction is incident on the two-dimensional image sensor 3. Therefore, from the two-dimensional image sensor 3, a square image having a standard visual field can be obtained in the horizontal direction while being compressed in the horizontal direction.

  As described above, since an optically quadrangular image is obtained, the control block shown in FIG. 4 does not require image conversion processing by image processing by calculation performed in a conventional wide-angle camera.

  Further, since the image is incident on the two-dimensional image sensor 3 in an optically rectangular photographing range, the light receiving element of the two-dimensional image sensor 3 is effectively used, and a fine and highly sensitive image can be obtained. .

And since the optical body 2a can be comprised with a reflective mirror, it can be produced cheaply and compactly. Specifically, it can be realized with a size of about 1 cm square.

In the wide-angle imaging device 1a, the reflecting mirror 6 of the optical body 2a has a shape of a part of an ellipse. Therefore, you may comprise by curved surfaces other than an ellipse.

  Further, although the light condensing means is configured by the pinhole 8, a configuration using a lens may be used.

<Modification of wide-angle imaging device>
8A and 8B show an example of the configuration of the wide-angle imaging device 1b according to the second embodiment. FIG. 8A is a perspective view and FIG. 8B is an XY plane sectional view. FIG. 8 schematically shows the optical system of the wide-angle imaging device 1b.

The wide-angle imaging device 1b according to the second embodiment includes an optical body 2b and a two-dimensional image sensor 3 as optical devices. The optical body 2 b includes an upper semiconical reflecting mirror 9 and a lower semiconical reflecting mirror 5 that are arranged facing each other vertically, and a reflecting mirror 6 that is arranged on the rear surface of the lower semiconical reflecting mirror 5.

  The lower semiconical reflecting mirror 5 has the same configuration as that of the first embodiment, and a concave semiconical reflecting surface 5a is formed on the inner surface. The upper semiconical reflecting mirror 9 has a semicircular frustoconical shape like the lower semiconical reflecting mirror 5, and a convex semiconical reflecting surface 9a is formed on the outer surface.

  The upper half-cone reflector 9 and the lower half-cone reflector 5 include an axis (Z axis) passing through the center of the arc R3 constituting the half-cone reflection surface 5a of the lower half-cone reflector 5 and the upper half-cone reflector 9 It arrange | positions up and down so that the axis which passes along the center of circular arc R3 which comprises the semiconical reflective surface 9a may correspond. Here, the arc R3 in FIG. 8 is an arc on the XY plane of the semiconical reflecting surface 5a.

  The semiconical reflecting surface 9a of the upper semiconical reflecting mirror 9 and the semiconical reflecting surface 5a of the lower semiconical reflecting mirror 5 are configured at an angle of 45 degrees with respect to the Z axis, and the semiconical reflecting surface is vertically moved in the circumferential direction. 9a and the semiconical reflecting surface 5a face each other.

In the wide-angle imaging device 1b, the upper half-cone reflecting mirror 9 has a semi-conical reflecting surface 9a formed on the outer surface, and the incident direction of light is opposite to that of the wide-angle imaging device 1a of the first embodiment. For this reason, the reflecting mirror 6 is provided on the rear surface facing the semiconical reflecting surface 5a in the horizontal direction.

The configuration of the reflector 6 is similar to the wide-angle imaging apparatus 1a of the first embodiment, the reflector 6 is a concave surface structure shape composed of a portion of an ellipse R2 in the horizontal direction, the first And a second focal point 6b.

In the reflecting mirror 6 , the first focal point 6a is located on the central axis of the lower semiconical reflecting mirror 5, and the second focal point 6b is located on the semiconical reflecting surface 5a of the lower semiconical reflecting mirror 5, A pinhole 8 is formed at a position corresponding to the second focal point 6b on the semiconical reflecting surface 5a. Further, the two-dimensional image sensor 3 is provided at a position where light reflected by the reflecting mirror 6 and passed through the pinhole 8 enters.

  Next, the operation of the wide-angle imaging device 1b according to the second embodiment will be described. The incident light β from a wide angle will be described as an example. Incident light β directed toward the center of the upper semiconical reflecting mirror 9 is reflected by the semiconical reflecting surface 9a and changed in direction to be incident on the lower semiconical reflecting mirror 5. .

The incident light β incident on the lower semiconical reflecting mirror 5 is reflected by the semiconical reflecting surface 5a, changes its direction, and enters the reflecting mirror 6 . In this way, the incident light β toward the center of the upper semiconical reflecting mirror 9 is sequentially reflected by the semiconical reflecting surfaces 9 a and 5 a and enters the reflecting mirror 6 through the center of the lower semiconical reflecting mirror 5.

The following operation is the same as that of the wide-angle imaging device 1a of the first embodiment, and the incident light β reflected by the semiconical reflecting surface 5a of the lower semiconical reflecting mirror 5 is the center of the lower semiconical reflecting mirror 5, that is, an ellipse. The light passes through the first focal point 6a of R2 and enters the reflecting mirror 6 .

Incident light β incident on the reflecting mirror 6 through the first focal point 6a is reflected by the reflecting mirror 6 and gathers at the second focal point 6b. Since the second focus 6 b includes the pinhole 8, the incident light β reflected by the reflecting mirror 6 passes through the pinhole 8 and forms an image on the two-dimensional image sensor 3.

Also in the wide-angle imaging device 1b of the second embodiment, since the semiconical reflecting surface 9a of the upper semiconical reflecting mirror 9 is semicircular, it can receive incident light from a wide angle, and the upper semiconical reflecting mirror 9 by the light is successively reflected a lower half-cone reflector 5 is incident on the reflecting mirror 6, the reflected light from the reflecting mirror 6, the horizontal radiation light passing through the first focal point 6a of the ellipse R2 The reflected light from the reflecting mirror 6 is incident on the two-dimensional image sensor 3 through the pinhole 8 .

  Thereby, the wide-angle imaging device 1b can also obtain an optically square image.

FIG. 9 shows an example of the configuration of the wide-angle imaging device 1c according to the third embodiment. FIG. 9A is a perspective view and FIG. 9B is an XZ plane sectional view. A wide-angle imaging device 1c according to the third embodiment includes an optical body 2a having a configuration similar to that of the wide-angle imaging device 1a according to the first embodiment, and reflects the incident light that has passed through the pinhole 8. And the arrangement of the two-dimensional image sensor 3 is changed.

  That is, the reflecting mirror 10 is provided on the rear surface of the lower semiconical reflecting mirror 5 so as to face the pinhole 8. The reflecting mirror 10 is a plane mirror and changes the optical path by 90 degrees, for example. The two-dimensional image sensor 3 is disposed below the reflecting mirror 10.

  Next, the operation of the wide-angle imaging device 1c according to the third embodiment will be described. The incident light γ and γ ′ tilted within a predetermined angle with respect to the horizontal direction will be described as an example. The incident light γ passes through the center of the upper semiconical reflecting mirror 4 and is reflected by the semiconical reflecting surface 4a to be directed. Instead, it enters the lower half cone reflector 5.

Incident light γ to the lower semiconical reflecting mirror 5 is reflected by the semiconical reflecting surface 5 a to change its direction, and enters the reflecting mirror 6 through the center of the lower semiconical reflecting mirror 5. The center of the lower half-cone reflector 5, i.e. through the first focal point 6a, the incident light γ incident on the reflecting mirror 6, collects in the second focal point 6b and reflected by the reflecting mirror 6. Since the second focus 6 b includes the pinhole 8, the incident light γ reflected by the reflecting mirror 6 passes through the pinhole 8. The incident light γ that has passed through the pinhole 8 is reflected by the reflecting mirror 10 and forms an image on the two-dimensional image sensor 3. The incident light γ ′ is also incident on the two-dimensional image sensor 3 by reflection at each reflecting mirror.

In the wide-angle imaging device 1c according to the third embodiment, since the two-dimensional image sensor 3 can be arranged below the optical body 2a, the depth of the wide-angle imaging device 1c can be reduced.

10A and 10B show an example of the configuration of a wide-angle imaging device 1d according to the fourth embodiment. FIG. 10A is a perspective view, and FIG. 10B is an XZ plane sectional view. A wide-angle imaging device 1d according to the fourth embodiment includes an optical body 2b having a configuration similar to that of the wide-angle imaging device 1b according to the second embodiment, and reflects the incident light that has passed through the pinhole 8. And the arrangement of the two-dimensional image sensor 3 is changed.

  That is, the reflecting mirror 10 is provided on the front surface of the lower semiconical reflecting mirror 5 so as to face the pinhole 8. The reflecting mirror 10 is a plane mirror and changes the optical path by 90 degrees, for example. The two-dimensional image sensor 3 is disposed below the reflecting mirror 10.

  Next, the operation of the wide-angle imaging device 1d according to the fourth embodiment will be described. The incident light γ and γ ′ tilted within a predetermined angle with respect to the horizontal direction will be described as an example. The incident light γ directed toward the center of the upper semiconical reflecting mirror 9 is reflected by the semiconical reflecting surface 9a and directed. Instead, it enters the lower half cone reflector 5.

Incident light γ to the lower semiconical reflecting mirror 5 is reflected by the semiconical reflecting surface 5 a to change its direction, and enters the reflecting mirror 6 through the center of the lower semiconical reflecting mirror 5. The following operation is the same as that of the wide-angle imaging device 1c of the third embodiment, and the incident light γ incident on the reflecting mirror 6 through the center of the lower semiconical reflecting mirror 5, that is, the first focal point 6a is reflected by the reflecting mirror. 6 is reflected at the second focal point 6 b and passes through the pinhole 8. The incident light γ that has passed through the pinhole 8 is reflected by the reflecting mirror 10 and forms an image on the two-dimensional image sensor 3. The incident light γ ′ is also incident on the two-dimensional image sensor 3 by reflection at each reflecting mirror.

Also in the wide-angle imaging device 1d of the fourth embodiment, since the two-dimensional image sensor 3 can be disposed below the optical body 2b, the depth of the wide-angle imaging device 1d can be reduced.

11A and 11B show an example of the configuration of a wide-angle imaging device 1e according to the fifth embodiment. FIG. 11A is a perspective view and FIG. 11B is a plan view. The wide-angle imaging device 1e according to the fifth embodiment is the wide-angle imaging device according to the first embodiment, except that the front surface of the entrance window 7 further includes a cylindrical concave lens 11 configured by a columnar curved surface that is convex in the horizontal direction. An optical body 2c having the same configuration as 1a is provided .

  Next, the operation of the wide-angle imaging device 1e according to the fifth embodiment will be described. The incident light β ′ from a wide angle of 180 ° or more in the horizontal direction will be described as an example. The incident light β ′ is refracted by the cylindrical concave lens 11 and passes through the center of the upper semiconical reflecting mirror 4 and is reflected by the semiconical reflecting surface 4a. The light is reflected and changed in direction, and is incident on the lower semiconical reflecting mirror 5.

The following operation is the same as that of the wide-angle imaging device 1a of the first embodiment, and the incident light β ′ to the lower semiconical reflecting mirror 5 is reflected by the semiconical reflecting surface 5a as shown in FIG. The direction is changed and the light passes through the center of the lower semiconical reflecting mirror 5 and enters the reflecting mirror 6 .

The incident light β ′ passing through the center of the lower semiconical reflecting mirror 5, that is, the first focal point 6 a and entering the reflecting mirror 6 is reflected by the reflecting mirror 6 and gathers at the second focal point 6 b and passes through the pinhole 8. Then, an image is formed on the two-dimensional image sensor 3.

  In the wide-angle imaging device 1e according to the fifth embodiment, the cylindrical concave lens 11 is provided on the front surface of the entrance window 7, so that wide-angle imaging of 180 degrees or more is possible.

<Specific example of wide-angle imaging device>
FIG. 12 is a perspective view showing a specific example of a wide-angle imaging device. In addition, in FIG. 12, the specific example of the wide angle imaging device 1a of 1st Embodiment is shown. In the configuration of FIG. 12A, the optical body 2a is formed of a block made of transparent glass or plastic, and the semiconical reflecting surfaces 4a and 5a and the reflecting mirror 6 are formed by mirror processing, and the incident window 7 and the pinhole are formed. The shielding part 12 is formed by performing a shielding process on the surface excluding 8.

In the configuration of FIG. 12B, the optical body 2a is formed by a plastic molding block 13 whose optical path portion is a space 13a, and the semiconical reflecting surfaces 4a and 5a and the reflecting mirror 6 are formed by mirror processing. .

  13 and 14 are explanatory diagrams illustrating application examples of the wide-angle imaging device. In the example shown in FIG. 13, the wide-angle imaging device 1 is attached to a bumper or the like on the front surface of the automobile 50.

  Since the wide-angle imaging device 1 has an angle of view of approximately 180 ° in the horizontal direction, the wide-angle imaging device 1 can be applied to a so-called blind corner camera that can check the left and right without entering the automobile 50 at a narrow intersection or the like.

  In the example shown in FIG. 14, the wide-angle imaging device 1 is attached to a rear-view mirror or the like on the side of the vehicle body opposite to the driver's seat in addition to the front surface of the vehicle 50. That is, the “right-side driving visibility standard” is legalized, and it is obliged to make it possible to directly or indirectly visually recognize a predetermined range on the side immediately before the automobile 50 and on the side opposite to the driver's seat.

  Since the wide-angle imaging device 1 has an angle of view of approximately 180 ° in the horizontal direction, if two wide-angle imaging devices 1 are provided, almost the entire front and side of the automobile 50 can be visually recognized indirectly.

  Since the wide-angle imaging device of the present invention has an angle of view of approximately 180 ° in the horizontal direction, the wide-angle imaging device is applied to a vehicle safety confirmation camera, door phone, and the like.

It is a perspective view which shows an example of a structure of the wide angle imaging device 1a of 1st Embodiment. It is a top view which shows an example of a structure of the wide angle imaging device 1a of 1st Embodiment. It is a XZ plane sectional view showing an example of composition of wide angle imaging device 1a of a 1st embodiment. It is a control block diagram which shows an example of the control system of the wide angle imaging device 1a. An example of the optical path in the horizontal direction of the light incident on the wide-angle imaging device 1a of the first embodiment is shown, FIG. 5A is a perspective view, and FIG. An example of the optical path in the horizontal direction of the light incident on the wide-angle imaging device 1a of the first embodiment from a wide angle is shown, FIG. 6 (a) is a perspective view, and FIG. 6 (b) is an XY plane sectional view. . It is a XZ plane sectional view showing an example of the optical path in the perpendicular direction of the light which entered into wide angle imaging device 1a of a 1st embodiment. FIG. 8A is a perspective view, and FIG. 8B is an XY plane cross-sectional view illustrating an example of a configuration of a wide-angle imaging device 1b according to a second embodiment. FIG. 9A is a perspective view and FIG. 9B is an XZ plane cross-sectional view illustrating an example of the configuration of a wide-angle imaging device 1c according to a third embodiment. FIG. 10A is a perspective view and FIG. 10B is an XZ plane cross-sectional view illustrating an example of the configuration of a wide-angle imaging device 1d according to a fourth embodiment. FIG. 11A is a perspective view and FIG. 11B is a plan view illustrating an example of the configuration of a wide-angle imaging device 1e according to a fifth embodiment. It is a perspective view which shows the specific example of a wide angle imaging device. It is explanatory drawing which shows the example of application of a wide angle imaging device. It is explanatory drawing which shows the example of application of a wide angle imaging device. It is explanatory drawing which shows the conventional wide angle imaging device.

DESCRIPTION OF SYMBOLS 1a-1d ... Wide-angle imaging device, 2a-2c ... Optical body , 3 ... Two-dimensional image sensor, 4 ... Upper half-cone reflective mirror, 4a ... Half-cone reflective surface, ...・ Lower semiconical reflector, 5a ・ ・ ・ Semiconical reflecting surface, 6 ・ ・ ・Reflecting mirror , 7 ・ ・ ・ Incoming window, 8 ・ ・ ・ Pinhole, 9 ・ ・ ・ Upper semiconical reflecting mirror, 9a ・ ・・ Semi-conical reflecting surface, 10 ... Reflecting mirror, 11 ... Cylindrical concave lens, 12 ... Shielding part, 13 ... Plastic molding block

Claims (3)

The right cone is cut by a plane parallel to the bottom surface to remove the portion including the apex, and further cut by the plane including the axis perpendicular to the bottom surface to divide into two symmetrical portions, and the one side surface divided A first reflecting surface having the same shape as the curved surface formed;
A cut surface including a pinhole, having the same shape as the first reflective surface, including an axis perpendicular to the bottom surface and the axis are matched, and the side corresponding to the bottom surface of the right cone is the first reflective surface A second reflective surface disposed below the first reflective surface so as to face
When an elliptic cylinder surface is assumed in which the axis perpendicular to the bottom surface passes through one focal point and the position where the pinhole is provided coincides with the other focal point, the cutting plane includes the axis perpendicular to the bottom surface. Of the two curved surfaces obtained by cutting, a third reflecting surface having the same shape as the curved surface on the smaller side;
An imaging means,
The incident light is reflected on the first and second reflecting surfaces in order to be incident on the third reflecting surface, and the reflected light from the third reflecting surface is condensed on the pinhole, A wide-angle imaging device that enters the imaging means. The right cone is cut by a plane parallel to the bottom surface to remove the portion including the apex, and further cut by the plane including the axis perpendicular to the bottom surface to divide into two symmetrical portions, and the one side surface divided A first reflecting surface having the same shape as the curved surface formed;
The lens has the same shape as the first reflecting surface, the cutting surface including the axis perpendicular to the bottom surface and the axis are matched, and the side corresponding to the bottom surface of the right cone is the first reflecting surface. A second reflecting surface disposed below the first reflecting surface so as to face each other;
When an elliptic cylinder surface is assumed in which the axis perpendicular to the bottom surface passes through one focal point and the position where the lens is provided coincides with the other focal point, cutting is performed at a cutting plane including the axis perpendicular to the bottom surface. A third reflecting surface having the same shape as the curved surface on the smaller side of the two curved surfaces obtained as described above,
An imaging means,
The incident light is reflected on the first and second reflecting surfaces in order and incident on the third reflecting surface, and the reflected light from the third reflecting surface is condensed on the lens, and the imaging is performed. A wide-angle imaging device that is incident on the means. A columnar concave lens is further provided on the light incident side with respect to the first reflecting surface,
The wide-angle imaging device according to claim 1, wherein light is incident on the first reflecting surface through the columnar concave lens.

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