On-vehicle camera

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a camera that captures an image, and more particularly to an in-vehicle camera that is attached to a vehicle and functions as an image sensor for determining the surrounding environment of the vehicle such as a white line on a road, a preceding vehicle, and an obstacle behind the vehicle.

【0002】

[Conventional technology]

In a conventional camera, as described in Japanese Patent Application Laid-Open No. 8-307743, a cylindrical lens is inserted into a cylindrical cylinder A, an image sensor is placed in another cylinder B, and then a cylinder is used. I put it in A and aligned the optical axis. Therefore, it is a cylinder-to-cylinder axis alignment structure, and there is no description about the detailed arrangement.

【0003】

[Problems to be Solved by the Invention]

Since the in-vehicle camera functions as an image sensor for determining the surrounding environment of the vehicle such as a white line on the road, a preceding vehicle, and an obstacle behind the vehicle, the mounting accuracy of the optical axis of the camera is important. That is, it is necessary to use a lens and an image sensor to direct the optical axis in the desired direction to capture an image. The image range captured by the image sensor changes depending on the optical axis between the camera lens and the image sensor and the mounting method between the case and the image sensor. Therefore, the accuracy of the optical axis is an issue. If the optical axis shifts, the captured image shifts, so an optical axis adjustment mechanism is required.

【0004】

The conventional camera has a structure in which a lens and an image sensor are arranged in a cylindrical cylinder so that the axes are aligned, but rotation with respect to the axes is not considered.

【0005】

An object of the present invention is to propose an in-vehicle camera having a structure that does not require optical axis adjustment.

【0006】

[Means for solving problems]

In order to achieve the above object, the present invention presents the position of the lens holder on the lens holder in an in-vehicle camera in which the image pickup element, the lens, the lens holder, the case, and the substrate to which the image pickup element is attached are attached to the lens holder. The image pickup element, which is attached to the lens holder by providing a protrusion for determining the lens, providing a hole in the case into which the protrusion is inserted, and fixing the relative position of the lens holder with respect to the case with the protrusion. The lens and the substrate are arranged in a fixed position with respect to the case.

【0007】

Another feature of the present invention is to align the center of the lens with the center of the image sensor attached to the substrate via the lens holder.

【0008】

Another feature of the present invention is that the camera case is provided with a hole for determining the mounting position of the lens holder, the positioning pin is provided on the substrate for the position of the lens holder and the image sensor, and the fitting portion between the lens holder and the lens is provided. It has a cylindrical shape and a gap fit to reduce the tolerance (play).

【0009】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an in-vehicle camera according to an embodiment of the present invention will be described. First, the outline of the mounting position of the in-vehicle camera with respect to the vehicle will be described with reference to FIGS. 1 to 5.

【0010】

The in-vehicle camera 1 is mounted on the ceiling of the own vehicle 6 as shown in FIG. 1, and the optical axis 2 is horizontal to the ground or an image in the range of 1 m to 200 m toward the ground as shown in the figure. Set so that it can be taken. As shown in FIG. 2, the in-vehicle camera 1 is used as an image sensor for determining the preceding vehicle 5, the white line 7, and the like. Further, in FIG. 2, the angle in the yaw direction is set so as to be substantially parallel to the straight line connecting the front wheels and the rear wheels of the car. Note that 4 in FIG. 2 shows a horizontal angle of view, and 3 in FIG. 3 shows a vertical angle of view.

【0011】

The in-vehicle camera 1 needs to capture an image by using a lens and an image sensor in the desired direction. FIG. 4 is a diagram showing a capture screen from the camera when the optical axis is normal. Further, FIG. 5 is a diagram showing a capture screen from the camera when the optical axis is abnormal. If the optical axis shifts, the captured image will be as shown in Fig. 5, and an optical axis adjustment mechanism is required. The present invention proposes a structure that does not require optical axis adjustment.

【0012】

6 to 9 show the optical system structure of the vehicle-mounted camera 1 according to the embodiment of the present invention. First, the camera mounted on the vehicle may check not only the front but also the rear and sides, and the optical axis is important regardless of the mounting location. Therefore, the optical axis error factors of the in-vehicle camera 1 considered from FIG. 6 are the accuracy of the case 10 and the accuracy of the optical system of the lens holder 11 and the lens 12.

【0013】

Further, as shown in FIG. 7, the lens holder 11 is fixed to the case 10 with screws. Further, in order to accurately determine the relative position of the lens holder 11 with respect to the case 10, the positioning pin 13 was used as shown in FIG. The shape of the pin 13 is cylindrical, and the hole 16 of the case 10 to which the positioning pin 13 of the lens holder 11 is attached is also circular as shown in FIG. If one of the positioning holes 16 of the case 10 is circular and the other is oval, it is possible to have a structure that absorbs mounting errors.

【0014】

In FIG. 9, the details of the optical system structure of the in-vehicle camera 1 will be described. The lens 12 insertion part of the lens holder 11 has a two-step fitting tolerance with a cylindrical hole and a threaded part so that the lens 12 can be inserted while rotating (for easy focusing). It has a structure. The substrate 14 to which the image sensor 15 is mounted has a positioning hole, and the structure is such that the image sensor 15 can be arranged at a fixed position when the positioning pin 13 of the lens holder 11 is inserted. The positioning pin 13 of the lens holder 11 is for positioning with the case 10 and determining the position with the substrate 14, and is composed of at least two or more.

【0015】

As shown in FIG. 9, the positioning pins of the lens holder penetrate the lens holder to be two or more, so that the positioning accuracy of the case with respect to the image sensor is improved.

【0016】

FIG. 10 is a view when FIG. 9 is disassembled, and is a diagram showing a structure in which the lens 12 and the image sensor 15 such as a CCD are aligned by the lens holder 11 in an easy-to-understand manner.

【0017】

If there is a gap when the lens 12 is inserted into the lens holder 11, the image capture angle (optical axis) changes. Therefore, by making the outer diameter L2 of the lens 12 of FIG. 9 smaller than the L1 of the portion inserted into the lens holder 11, the optical axis error of the lens 12 with respect to the lens holder 11 can be reduced. 0 That is, when the fitting tolerance between the lens 12 and the lens holder 11 is constant, the longer the insertion portion of the lens 12 into the lens holder 11, the smaller the error.

【0018】

The surfaces of the peripheral parts of the lens holder 11 and the lens 12 are black (anodized) so that the light entering from the lens 12 does not internally reflect until it reaches the image sensor 15.

【0019】

According to the embodiment of the present invention, the accuracy of the optical axis 2 can be improved by improving the mounting accuracy of each component with respect to the case 10. That is, the accuracy of each part with respect to the case can be improved, the accuracy of the optical axis as a sensor for capturing an image can be improved, and the deviation of the captured image can be reduced. Therefore, it is possible to provide a structure that does not require optical axis adjustment.

【0020】

[Effect of the invention]

According to the present invention, the accuracy of the optical axis can be improved by improving the mounting accuracy of each component to the in-vehicle camera case, and the deviation of the captured image can be reduced. realizable.

[Simple explanation of drawings]

[Figure 1]

It is a figure which shows the state which the image processing camera which is the object of this invention is attached to a vehicle.

[Figure 2]

It is a figure which shows the relationship in the horizontal direction between the optical axis and the angle of view of the in-vehicle camera attached to a vehicle.

[Fig. 3]

It is a figure which shows the relationship in the vertical direction between the optical axis and the angle of view of the in-vehicle camera attached to a vehicle.

[Fig. 4]

It is a figure which shows the capture screen from a camera when the optical axis is normal.

[Fig. 5]

It is a figure which shows the capture screen from a camera when the optical axis is abnormal.

[Fig. 6]

It is a figure which shows the planar structure of the vehicle-mounted camera which becomes the Example of this invention.

[Fig. 7]

It is a figure which shows the structure (front view) of the vehicle-mounted camera of FIG.

[Fig. 8]

It is a figure which shows the vertical cross section of the vehicle-mounted camera of FIG.

[Fig. 9]

It is a figure which shows the structure of the AA cross section of FIG.

[Fig. 10]

It is a figure which shows the assembly detailed drawing of the in-vehicle camera of FIG.

[Explanation of symbols]

1 ... in-vehicle camera, 2 ... optical axis, 3 ... vertical angle of view, 4 ... horizontal angle of view, 5 ... preceding vehicle, 6 ... own vehicle, 7 ... white line, 8 ... Center of captured image, 9 ... Captured image from image sensor, 10 ... In-vehicle camera case, 11 ... Lens holder, 12 ... Lens, 13 ... Pin, 14. .. Substrate, 15 ... Imaging elements (CCD, COM, etc), 16 ... Positioning holes.