JP2002077896A - On-vehicle imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle imaging device capable of effectively suppressing mixing of lights from right and left imaging areas on a photodetecting surface of an imaging element with a light from a lower or upper side imaging area and improving an image quality. SOLUTION: This on-vehicle imaging device 21 comprises a light shielding plate 23 for dividing optical paths of lights 17L and 17R from left and right imaging areas, reflected by side faces 13L and 13R of a prism 13 and incident to an imaging lens 15b in a case 11; and an optical path of a light 17D from a lower side imaging area, incident to the lens 15b at an incident surface side of the lens 15b.

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 for simultaneously picking up image pickup areas in three different directions around a vehicle.

[0002]

2. Description of the Related Art As a conventional vehicle-mounted image pickup apparatus of this type,
2 and 3 are shown. This in-vehicle imaging device 1
Are installed facing the outside of the vehicle, and the first and second imaging regions on the left and right with respect to the front direction A of the vehicle-mounted imaging device 1 and the lower or upper side (here, the lower side) with respect to the front direction A
Are simultaneously imaged with the third imaging region. The image pickup areas in the three directions are set in blind spot areas around the vehicle that are difficult for the driver to see. As a preferable use form of such an in-vehicle imaging device 1, the in-vehicle imaging device 1 is installed at the front end of a vehicle, and the left and right blind spot areas on the front side of the vehicle, and the front nose are used by the in-vehicle imaging device. For example, it is conceivable to take an image of a blind spot area obliquely below the front end of the vehicle, which becomes a shadow and is difficult for the driver to see.

As shown in FIGS. 2 and 3, a light-shielding case 11 of the image pickup apparatus 1 has a pair of transmissive windows 11L, 1
1R, a transmission window 11D is provided diagonally below. The left and right transmission windows 11L and 11R are for introducing the lights 17L and 17R from the left and right imaging regions, and the lower transmission window 11D is for introducing the light 17D from the lower imaging region. belongs to.

In the case 11, a prism 13 having a triangular cross section in a plan view has its apex side directed toward the front of the case 11 (the upper part of the case 11 in FIG. 2) and forms the triangle. The left and right two prism side surfaces 13L and 13R of the three side surfaces are housed and arranged in a posture facing the left and right transmission windows 11L and 11R, respectively, and an image is taken so as to be located on the back side of the prism 13. The unit 15 is accommodated and arranged.

The image pickup unit 15 includes an image pickup device (CCD)
Etc.) 15a and an imaging lens 15b. The imaging unit 15 is installed such that the imaging optical axis B, which is the optical axis of the imaging lens 15b, faces obliquely downward with respect to the front direction A. Then, the imaging element 15a captures an image formed by the imaging lens 15b.

Here, the prism 13 is disposed on the lower transmission window 1.
In order to avoid the optical path of the light 17D incident from 1D toward the imaging lens 15b, it is installed on the upper side of the optical path so as to be perpendicular to the front direction A, and the lower surface 13a of the prism 13 is The inclined surface is inclined downward toward the front side substantially along the optical path of the light 17D. Here, the imaging viewing angle Ca for imaging the left and right imaging regions is set in the upper half of the total imaging viewing angle C of the imaging device 15a and the imaging lens 15b with respect to the vertical direction. An imaging viewing angle Cb for imaging the lower imaging area is set in the lower half area of the angle C, and the inclination angle of the lower surface 13a of the prism 13 and the installation position of the prism 13 are determined by the lower surface 13a. The setting is made along the imaging optical axis B.

[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 mounted on 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 transfer 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.

[0009]

However, in the above-mentioned conventional in-vehicle imaging apparatus 1, the optical paths of the lights 17L and 17R from the left and right imaging areas and the optical paths of the light 17D from the lower imaging area in the case 11 are described. Because there is no means for dividing the light from the imaging region 15a, the light from the originally lower imaging region is affected by the optical paths of the lights 17L, 17R, and 17D and the refraction of the imaging lens 15b on the light receiving surface of the imaging device 15a. The light 17L and 17R from the left and right imaging regions enter the light receiving region where the 17D should enter, or conversely, the light 17L and 17R from the left and right imaging regions fall into the light receiving region where they should originally enter. Is disadvantageous that the light 17D from the imaging region of the above enters. Such light 17L,
Mixing of 17R and light 17D causes deterioration of image quality.

In view of the above problems, the present invention can effectively suppress the mixture of light from the left and right imaging regions and light from the lower or upper imaging region on the light receiving surface of the imaging device, and can improve the image quality. It is an object of the present invention to provide an in-vehicle imaging device capable of improving the image quality.

[0011]

Technical means for achieving the above object include an image forming lens, an image pickup device for picking up an image formed by the image forming lens, and an incident surface of the image forming lens. A prism provided on the side, having a triangular cross-sectional shape, and two right and left side surfaces of the three side surfaces constituting the triangle function as reflection surfaces, and are installed facing the outside of the vehicle. Each light incident from the first and second imaging regions on the left and right with respect to the front direction of the vehicle-mounted imaging device is reflected by the left and right side surfaces of the prism and is incident on the imaging device via the imaging lens. In addition, light incident from the third imaging region below or above the front direction is directly introduced into the imaging lens without passing through the prism, and is incident on the imaging device via the imaging lens. Be done A vehicle-mounted imaging device, wherein, on an incident surface side of the imaging lens, each of the lights from the first and second imaging regions reflected by the prism and incident on the imaging lens. Light path,
A light-shielding unit is provided for dividing an optical path of the light from the third imaging region incident on the imaging lens.

Preferably, the light shielding means is a light shielding plate provided on the lower surface side or the upper surface side of the prism.

Preferably, the light shielding means is a light shielding film provided on a lower surface or an upper surface of the prism.

[0014]

FIG. 1 is a longitudinal sectional view showing the structure of an on-vehicle imaging apparatus according to an embodiment of the present invention. The only difference between the vehicle-mounted imaging device 21 according to the present embodiment and the above-described vehicle-mounted imaging device 1 shown in FIGS. 2 and 3 is that a vehicle-mounted imaging device 21 is provided with a light-shielding plate (light-shielding unit) 23 described later. Portions are denoted by the same reference numerals, and redundant description will be omitted.

In the on-vehicle imaging device 21, on the incident surface side of the imaging lens 15b in the case 11, each of the left and right imaging regions reflected by the prism side surfaces 13L and 13R of the prism 13 and incident on the imaging lens 15b. A light shielding plate 23 is provided for dividing the optical paths of the lights 17L and 17R and the optical path of the light 17D from the lower imaging region that enters the imaging lens 15b. In this embodiment, the light shielding plate 2
3 is the lower surface 13a (or upper surface 13b) of the prism 13
It is fixed and installed. That is, the light shielding plate 23
Is to vertically partition an imaging viewing angle Ca for imaging left and right imaging areas and an imaging viewing angle Cb for imaging a lower imaging area on the incident surface side of the imaging lens 15b. It is arranged.

With such a configuration, the light 17 from the left and right image pickup areas on the light receiving surface of the image pickup device 15a is provided.
L, 17R incident area and light 17 from the lower imaging area.
The overlap with the incident area of D as in the related art can be effectively suppressed.

As described above, according to the present embodiment, the light 17L and 17R from the left and right imaging areas and the lower imaging area on the light receiving surface of the imaging element 15a are controlled by the light shielding plate 23 according to the present embodiment. Can be effectively suppressed from being mixed with the light 17D, and the image quality can be improved.

Further, by adjusting the size and shape of the light shielding plate 23, the light 17L, 1
The optical path of 7R and the optical path of light 17D from the lower imaging area can be reliably divided.

As a modification of this embodiment, a light shielding film may be provided on the lower surface 13a or the upper surface 13b of the prism 13 instead of providing the light shielding plate 23. by this,
The number of parts and the number of assembling steps can be reduced as compared with the case where the light shielding plate 21 is provided separately from the prism 13.

[0020]

According to the first aspect of the present invention, the optical path of each light from the first and second imaging regions reflected by the prism and entering the imaging lens on the incident surface side of the imaging lens. And light shielding means for dividing the optical path of the light from the third imaging area incident on the imaging lens, so that the light from the left and right imaging areas on the light receiving surface of the imaging device is provided by the light shielding means. And light from the lower or upper imaging area can be effectively suppressed, and the image quality can be improved.

According to the second aspect of the present invention, by adjusting the size and shape of the light shielding plate, the light path of the light from the left and right imaging areas and the light path of the light from the lower or upper imaging area are adjusted. It can be divided reliably.

According to the third aspect of the present invention, since the light shielding means is constituted by the light shielding film provided on the lower surface or the upper surface of the prism, the number of parts and the number of parts can be reduced as compared with the case where a light shielding plate is provided separately from the prism. The number of assembly steps can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view showing a configuration of a conventional in-vehicle imaging device and the like.

FIG. 3 is a longitudinal sectional view illustrating a configuration of the vehicle-mounted imaging device in FIG. 2;

[Explanation of symbols]

 Reference Signs List 7 display device 11 case 13 prism 13L, 13R prism side surface 15a imaging device 15b imaging lens 17L, 17R, 17D light 21 vehicle-mounted imaging device 23 light shielding plate A frontal direction

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideo Kato 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi F-term in Harness Research Institute, Inc. (reference) 2H042 CA01 CA06 CA17 5C022 AA04 AB62 AC54 AC69 AC77 CA00 5C054 AA01 CA04 CC05 CE08 CE15 CH01 EA01 FE12 FE17 HA30

Claims (3)

[Claims] 1. An image forming lens, an image pickup element for picking up an image formed by the image forming lens, and a triangular cross-sectional shape provided on an incident surface side of the image forming lens. And a prism whose left and right two side surfaces among the three side surfaces constitute a reflection surface, and are installed facing the outside of the vehicle. Each light incident from the imaging region of No. 2 is reflected by the left and right side surfaces of the prism and is incident on the imaging element via the imaging lens,
Light incident from a third imaging region below or above the front direction is directly introduced into the imaging lens without passing through the prism, and is incident on the imaging device via the imaging lens. A vehicle-mounted imaging apparatus according to claim 1, wherein, on the incident surface side of the imaging lens, each of the light beams from the first and second imaging regions reflected by the prism and incident on the imaging lens. An on-vehicle imaging apparatus, further comprising: a light blocking unit that divides an optical path and an optical path of the light from the third imaging region incident on the imaging lens. 2. The on-vehicle image pickup device according to claim 1, wherein the light shielding means is a light shielding plate provided on a lower surface side or an upper surface side of the prism. 3. The in-vehicle imaging device according to claim 1, wherein the light shielding unit is a light shielding film provided on a lower surface or an upper surface of the prism.