JP2002067793A - On-vehicle image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle image pickup device capable of simultaneously picking up images of left and right image pickup areas and a lower or upper side image pickup area largely dislocated in the lower or upper direction to the front direction of this on-vehicle image pickup device from the left and right image pickup areas without expanding an image pickup visibility angle in the vertical direction of an image pickup optical system. SOLUTION: In this on-vehicle image pickup device 21, the light 17L and 17R from the left and right image pickup areas are reflected in the front direction A of this device 21 by prism side surfaces 13L and 13R of a prism 13, and are introduced to an image pickup element 15a via an image forming lens 15b, and while, the light 17D from the lower side image pickup area is reflected by a reflecting plate 23, and is introduced to the image pickup element 15a via the image forming lens 15b. The reflecting plate 23 is integrally arranged on an under surface 13a of the prism 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle image pickup apparatus which is installed facing the outside of a vehicle and has first and second image pickup areas on the left and right sides with respect to the front direction of the vehicle-mounted image pickup apparatus. The present invention relates to an in-vehicle imaging device that simultaneously images an upper third imaging region.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a technique of installing a vehicle-mounted image pickup apparatus of this type in a vehicle to image a blind spot in three directions that is difficult for a driver around the vehicle to see. FIG. 5 and FIG. It is a figure which shows an example of the suitable use form of such an in-vehicle imaging device. In this example, the in-vehicle imaging device 1 is installed at the front end portion 2 of the vehicle, and the in-vehicle imaging device 1 makes the left and right imaging regions 3L and 3R on the front side of the vehicle and the front nose less visible to the driver. The imaging region 3D obliquely below the front end of the vehicle is imaged.

FIG. 7 is a cross-sectional view showing the structure of such a conventional in-vehicle imaging device and a device connected thereto.
FIG. 8 is a longitudinal sectional view showing the configuration of the vehicle-mounted imaging device of FIG. As shown in FIG. 7 and FIG.
A transmission window 11D is provided diagonally below. The left and right transmission windows 11L and 11R are provided with respective lights 17 from the left and right imaging regions.
L, 17R, and the lower transmission window 11D is for introducing light 17D from the lower imaging region.

In the case 11, a prism (first optical path changing means) 13 having a triangular cross section in plan view is provided.
However, the apex angle side is the front part of the case 11 (in FIG.
1 and the left and right prism side surfaces (first and second reflection surfaces) 13L and 13R of the three side surfaces forming the triangle.
The image pickup unit 15 is accommodated and disposed in a posture facing the 1L and 11R sides, and the image pickup unit 15 is accommodated and arranged so as to be positioned on the back side of the prism 13.

The image pickup unit 15 includes an image pickup device (CCD)
Etc.) 15a and an imaging lens 15b. The imaging element 15a captures an image formed by the imaging lens 15b.

The prism 13 has a lower transmission window 11.
In order to avoid the optical path of the light 17D incident from D to the image forming lens 15b, it is installed on the upper side of the optical path so as to be upright at right angles to the front direction A. Then, an imaging field angle Ca for imaging left and right imaging areas is set in an upper half area of the entire imaging field angle C in the vertical direction of the imaging optical system including the imaging element 15a and the imaging lens 15b. The imaging viewing angle Cb for imaging the lower imaging area is set in the lower half area of the entire imaging viewing angle C.

[0007] Then, the transmission window 13 from the left and right imaging areas.
The lights 17L and 17R that have entered through the left and right prisms 13R and 13R pass through the right and left prism side surfaces 13L and 13R, respectively.
And is totally reflected by the opposite prism side surfaces 13L and 13R toward the imaging lens 15b, exits the prism 13, and enters the imaging device 15a via the imaging lens 15b. On the other hand, light 17D incident from the lower imaging region via the transmission window 11D is directly introduced into the imaging lens 15b without passing through the prism 13, and is incident on the imaging element 15a via the imaging lens 15b. As a result, images of the image pickup areas in the left, right, lower, and three directions are picked up by the single image pickup device 15a.

The image signal output from the image pickup device 15a is input to a predetermined processing unit 5, subjected to a predetermined process such as an inversion process, and given to a display device 7 in the vehicle.
The image of each imaging area taken by a is displayed by the display device 7. Here, the display area on the screen of the display device 7 is divided into three partial areas 7L, 7R, and 7D. An image of the left imaging area is displayed in the upper left partial area 7L, and the upper right partial area 7R is displayed. The image of the right imaging area is displayed on the right, and the image of the lower imaging area is displayed on the lower partial area 7D.

For example, when such an in-vehicle imaging device 1 is set at the vehicle front end 2 as shown in FIGS. 5 and 6 to perform imaging of the imaging regions 3L, 3R, and 3D, the in-vehicle imaging device 1 The vehicle is installed so that its front direction A is parallel to the horizontal direction and faces the front direction of the vehicle. The left and right imaging regions 3L and 3R are set so that, for example, the center axis is substantially parallel to the horizontal direction so that the left and right directions of the four corners can be accurately imaged when the vehicle approaches a four-sided corner or the like with poor visibility. There is a demand that it is preferable to do so.
In addition, the lower imaging region 3D is configured to accurately capture an area immediately below the vehicle front end 2 which is a driver's blind spot.
For example, there is a demand that it is preferable to set the central axis so as to face downward at a large angle with respect to the horizontal direction.

In response to such a request, the imaging unit 15
Of the imaging optical axis B of the left and right sides of the imaging region 3L, 3R, so that the center axis of the imaging viewing angle Ca for imaging the left and right imaging regions 3L and 3R is substantially parallel to the horizontal direction, and forms an angle D downward with respect to the horizontal direction. Is set.

Note that the total imaging viewing angle C of the imaging optical system of the on-vehicle imaging device 1 is limited to a certain limit (for example, 40 °) in order to suppress distortion or the like of a captured image. I have.

[0012]

However, in the above-described conventional in-vehicle imaging apparatus 1, the light 17D from the lower imaging area (3D) incident through the transmission window 11D is directly introduced into the imaging lens 15b. Therefore, the lower imaging region (3D) is moved left and right with respect to the vertical direction due to the restriction on the entire imaging viewing angle C of the imaging optical system.
(L, 3R), it is difficult to effectively image the imaging area 3D immediately below the vehicle front end 2 when installed at the vehicle front end 2 as described above. There's a problem.

Therefore, in view of the above problems, the present invention does not increase the imaging field of view of the imaging optical system in the vertical direction, but instead moves the left and right imaging regions and the left and right imaging regions in the front direction of the vehicle-mounted imaging device. It is an object of the present invention to provide an in-vehicle imaging device that can simultaneously image a lower or upper imaging region largely deviated downward or upward with a single imaging element.

[0014]

The technical means for achieving the above object is provided facing the outside of the vehicle, and includes first and second imaging areas on the left and right with respect to the front direction of the vehicle-mounted imaging apparatus. A vehicle-mounted imaging device that simultaneously captures a lower or upper third imaging region with respect to the front direction, comprising: an imaging lens; and an imaging device that captures an image formed by the imaging lens. By reflecting each light incident from the first and second imaging regions on the first and second reflection surfaces, the light path is converted and introduced into the imaging lens, and the light is incident on the imaging element. A first optical path changing means for causing the light incident from the third imaging area to be reflected or refracted so as to convert the light path to be introduced into the imaging lens and to enter the image pickup element; Light path conversion means; And wherein the Rukoto.

Preferably, the first optical path changing means includes:
It is provided on the incident surface side of the imaging lens, has a triangular cross-sectional shape, and two left and right side surfaces of the three side surfaces constituting the triangle function as the first and second reflection surfaces. It is a prism, and the second optical path changing means is preferably a reflector integrally provided on the lower surface or the upper surface of the prism.

Preferably, the first optical path changing means is provided on the incident surface side of the imaging lens, has a triangular cross-sectional shape, and has left and right sides of three side surfaces constituting the triangle. Two side surfaces are prisms functioning as the first and second reflection surfaces, and the second optical path conversion means is preferably a reflection film integrally provided on the lower surface or the upper surface of the prism. .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a longitudinal sectional view showing a configuration of an in-vehicle imaging device according to a first embodiment of the present invention. The only difference between the in-vehicle imaging device 21 according to the present embodiment and the in-vehicle imaging device 1 shown in FIGS. 7 and 8 is a reflector (second optical path changing unit) 23 described later and points related thereto. , And corresponding parts are denoted by the same reference symbols, and redundant description will be omitted.

In the vehicle-mounted imaging device 21, the imaging viewing angle C
b corresponding to the lower surface 13a or the upper surface 13 of the prism 13.
b (here, the lower surface 13 a) is provided integrally with the reflecting plate 23, and the light 17 </ b> D entering from the imaging area below or above (here, the lower side) with respect to the front direction A is reflected by the reflecting plate 23. As a result, the optical path is changed, the light path is introduced into the imaging lens 15b, and is incident on the image sensor 15a. Here, the reflection plate 23 is fixed to the lower surface 13a of the prism 13 with an adhesive or the like.

The inclination angle E of the lower surface 13a of the prism 13 and the reflecting plate 23 fixed to the lower surface 13a with respect to the front direction A is the light 17D from the desired lower imaging area.
Is set to a value necessary to guide the light to the imaging lens 15b and the imaging element 15a.

Then, light 17L from the left and right imaging areas,
17R is reflected by the prism side surfaces 13L and 13R of the prism 13 and passes through the imaging lens 15b to the image sensor 1
5A, while the light 17D from the lower imaging area
Is reflected by the reflection plate 23 and introduced into the image sensor 15a via the imaging lens 15b.

With this arrangement, the left and right imaging regions can be adjusted without increasing the imaging viewing angle C in the vertical direction of the imaging optical system including the imaging element 15a and the imaging lens 15b.
A single imaging element 15a can simultaneously capture an image of the lower imaging region that is largely deviated downward from the left and right imaging regions with respect to the front direction A. For example, the in-vehicle imaging device 21 according to the present embodiment is installed at the front end portion 2 of the vehicle in the same manner as in the case of the above-described in-vehicle imaging device 1, and the left and right imaging regions 3L and 3R (see FIG. When the imaging area 3D (see FIG. 6) is imaged, the in-vehicle imaging apparatus 21 accurately captures the left and right imaging areas 3L and 3R, and the vehicle front end 2 that is difficult to image with the conventional in-vehicle imaging apparatus 1. It is possible to easily image the imaging area 3D immediately below.

The reflecting plate 23 is provided on the lower surface 1 of the prism 13.
Since the prism 23 and the reflection plate 23 are integrally provided on the component 3a, the prism 23 and the reflection plate 23 can be handled as one component, and the number of components and the number of assembly steps can be reduced.

Further, on the incident surface side of the imaging lens 15b, the light is reflected by the prism 13 and
17L, 17R from left and right imaging areas incident on b
And the imaging lens 1 reflected by the reflection plate 23
The light path of the light 17D from the lower imaging area incident on the light-receiving element 5b can be effectively split by the reflection plate 23, whereby the light 17L from the left and right imaging areas on the light receiving surface of the imaging element 15a can be divided. Mixing of 17R and light 17D from the lower imaging region can be effectively suppressed, and the image quality can be improved.

In this embodiment, the second optical path changing means is constituted by the reflection plate 23. However, the second optical path changing means is constituted by a reflection film provided integrally on the lower surface 13a or the upper surface 13b of the prism 13. You may comprise. in this case,
The reflection film is formed on the lower surface 13a or the upper surface 13b of the prism 13.
Formed by a metal film or the like provided on the substrate.

<Second Embodiment> FIG. 2 is a longitudinal sectional view showing a configuration of a main part of an in-vehicle imaging device according to a second embodiment of the present invention. The only difference between the in-vehicle imaging device 21 according to the present embodiment and the in-vehicle imaging device 21 according to the above-described first embodiment is that the reflector 23 is installed in the case 11 separately from the prism 13. The corresponding parts are denoted by the same reference numerals, and redundant description will be omitted.

Also in this embodiment, the left and right imaging regions and the left and right imaging regions largely deviate downward from the front direction A without expanding the imaging viewing angle C in the vertical direction of the imaging optical system. The lower imaging region can be simultaneously imaged by the single imaging device 15a, and the light 17L and 17R from the left and right imaging regions and the light 17 from the lower imaging region on the light receiving surface of the imaging device 15a can be obtained.
Mixing with D can be effectively suppressed by the reflection plate 23.

<Third Embodiment> FIG. 3 is a longitudinal sectional view showing a configuration of a main part of an in-vehicle imaging device according to a third embodiment of the present invention. The only difference between the in-vehicle imaging device 21 according to the present embodiment and the in-vehicle imaging device 21 according to the above-described first embodiment is that the in-vehicle imaging device 21 according to the first embodiment uses a prism 25 instead of the reflection plate 23 as the second optical path conversion unit. , And corresponding parts are denoted by the same reference symbols, and redundant description will be omitted.

In the present embodiment, a prism 25 is provided below the prism 13 corresponding to the imaging viewing angle Cb, and the light 17D incident from the imaging area below the front direction A is provided.
Is refracted by the prism 25, changes its optical path, is introduced into the imaging lens 15b, and is incident on the image sensor 15a.

Here, the prism 25 has a triangular longitudinal cross-sectional shape, and refracts the light 17D incident from the lower image pickup area by two prism side surfaces 25a and 25b crossing the mountain substantially upward. Then, the optical path is changed to the image forming lens 15b side. The angle of inclination of the prism 25 with respect to the front direction A and the angle between the two prism side surfaces 25a and 25b are necessary for guiding the light 17D from the desired lower imaging area to the imaging lens 15b and the imaging element 15a. It is set to each value.

As described above, also in the present embodiment, the left and right imaging regions and the right and left imaging regions can be lowered with respect to the front direction A without increasing the imaging viewing angle C in the vertical direction of the imaging optical system. A single imaging element 15a can simultaneously capture an image of the lower imaging area that is largely deviated in the direction.

<Fourth Embodiment> FIG. 4 is a longitudinal sectional view showing a configuration of a main part of an in-vehicle imaging device according to a fourth embodiment of the present invention. The in-vehicle imaging device 21 according to the present embodiment is substantially different from the in-vehicle imaging device 21 according to the above-described first embodiment in that a prism 27 is used instead of the reflection plate 23 as a second optical path conversion unit. , The lower imaging area is imaged with the upper imaging viewing angle Ca, and the left and right imaging areas are imaged with the lower imaging viewing angle Cb. The description of the operation will be omitted.

In this embodiment, since the left and right imaging regions are imaged by the lower imaging viewing angle Cb, the imaging optical axis B of the imaging unit 15 is set so that the central axis of the imaging viewing angle Cb is substantially parallel to the horizontal direction. Thus, the angle Da is set upward with respect to the horizontal direction.

In the present embodiment, the prism 27 is provided above the prism 13 in correspondence with the imaging viewing angle Ca, and the light 17D incident from the imaging area below the front direction A is provided.
Is refracted by the prism 27 so as to change its optical path, is introduced into the imaging lens 15b, and is incident on the image sensor 15a.

Here, the prism 27 has a triangular longitudinal cross-sectional shape, and refracts the light 17D incident from the lower imaging region by two prism side surfaces 27a and 27b which cross substantially in a chevron upward. The optical path is changed by the imaging lens 15b. The angle of inclination of the prism 27 with respect to the front direction A and the angle between the two prism side surfaces 27a and 27b are necessary for guiding the light 17D from the desired lower imaging area to the imaging lens 15b and the imaging element 15a. It is set to each value.

As described above, also in the present embodiment, the left and right imaging regions and the right and left imaging regions can be lowered with respect to the front direction A without increasing the imaging viewing angle C in the vertical direction of the imaging optical system. A single imaging element 15a can simultaneously capture an image of the lower imaging area that is largely deviated in the direction.

[0036]

According to the first aspect of the present invention, in addition to the first optical path changing means for converting the optical paths of the light from the first and second imaging regions and introducing the converted light into the imaging lens, The second optical path changing means for converting the optical path by reflecting or refracting the light incident from the imaging area No. 3 and introducing the light into the image forming lens is provided. A first and second imaging region without increasing an imaging viewing angle in the vertical direction of the system;
A single imaging device can simultaneously capture an image of the third imaging region that is largely deviated downward or upward from the first and second imaging regions with respect to the front direction of the vehicle-mounted imaging device.

According to the second aspect of the present invention, since the reflector serving as the second optical path changing means is integrally provided on the lower surface or the upper surface of the prism serving as the first optical path changing means, the prism and the reflecting plate are integrated. The second optical path changing means can be handled as one part, and the number of parts and the number of assembling steps can be reduced.

On the incident surface side of the imaging lens, the optical path of each light from the first and second imaging areas reflected by the prism and incident on the imaging lens, and the imaging lens reflected by the reflection plate The optical path of the light from the third imaging region incident on the imaging device can be effectively divided by the reflector, whereby the light from the left and right imaging regions on the light receiving surface of the imaging device and the lower or upper imaging Mixing with light from the region can be effectively suppressed, and image quality can be improved.

According to the third aspect of the present invention, since the reflecting film as the second optical path changing means is provided integrally on the lower surface or the upper surface of the prism as the first optical path changing means, the prism and the reflecting film are formed integrally. The second optical path changing means can be handled as one part, and the number of parts and the number of assembling steps can be reduced.

Further, since the reflecting film as the second optical path changing means is provided integrally on the lower surface or the upper surface of the prism as the first optical path changing means, the prism is provided on the incident surface side of the imaging lens. The optical path of each light from the first and second imaging regions reflected and incident on the imaging lens and the optical path of light from the third imaging region reflected by the reflective film and incident on the imaging lens are reflected. The film can be effectively divided, whereby the mixture of the light from the left and right imaging regions and the light from the lower or upper imaging region on the light receiving surface of the imaging device can be effectively suppressed, and the image quality can be reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating a configuration of a vehicle-mounted imaging device according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view illustrating a configuration of a main part of an in-vehicle imaging device according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view illustrating a configuration of a main part of an in-vehicle imaging device according to a third embodiment of the present invention.

FIG. 4 is a longitudinal sectional view illustrating a configuration of a main part of an in-vehicle imaging device according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing an example of a preferable use form of the in-vehicle imaging device in FIG. 1;

FIG. 6 is a diagram showing an example of a preferred use form of the in-vehicle imaging device in FIG. 1;

FIG. 7 is a cross-sectional view showing a configuration of a conventional in-vehicle imaging device and the like.

8 is a longitudinal sectional view showing a configuration of the vehicle-mounted imaging device in FIG. 7;

[Explanation of symbols]

 Reference Signs List 7 display device 11 case 13 prism 13L, 13R prism side surface 15a imaging element 15b imaging lens 17L, 17R, 17D light 21 in-vehicle imaging device 23 reflector 25, 27 prism A front direction

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Okada 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi F-term in Harness Research Institute, Inc. (reference) 5C022 AA04 AB62 AB68 AC51 AC54 AC78 5C054 AA01 CA04 CE08 CF06 CG02 EA01 HA30

Claims (3)

[Claims] 1. An in-vehicle imaging apparatus which is installed facing the outside of a vehicle and has first and second imaging areas on the left and right sides with respect to a front direction of the vehicle-mounted imaging apparatus, and a third imaging area which is lower or upper with respect to the front direction. An in-vehicle imaging device that simultaneously captures an image of an area, an imaging lens, an imaging element that captures an image formed by the imaging lens, and each light incident from the first and second imaging areas. Is reflected by the first and second reflection surfaces to convert the optical path, introduce the light into the imaging lens, and make the light incident on the image sensor. A second optical path conversion unit that converts the light path of the incident light by reflecting or refracting the light, introduces the light into the imaging lens, and makes the light incident on the image pickup device. 2. The first optical path changing means is provided on an incident surface side of the imaging lens, has a triangular cross-sectional shape,
The left and right two side surfaces of the three side surfaces constituting the triangle are prisms functioning as the first and second reflection surfaces, and the second optical path changing means is provided on a lower surface or an upper surface of the prism. The in-vehicle image pickup device according to claim 1, wherein the image pickup device is a reflector provided integrally. 3. The first optical path changing means is provided on the incident surface side of the imaging lens, has a triangular cross-sectional shape,
The left and right two side surfaces of the three side surfaces constituting the triangle are prisms functioning as the first and second reflection surfaces, and the second optical path changing means is provided on a lower surface or an upper surface of the prism. The on-vehicle imaging device according to claim 1, wherein the on-vehicle imaging device is a reflection film provided integrally.