JPS6355161B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel vehicle headlamp lens,
Specifically, the present invention aims to provide a lens with improved light distribution performance in which the upper part of the lens is inclined toward the rear side of the lens, thereby making it possible to obtain a vehicle headlamp with excellent visibility.

When a vehicle such as an automobile has a molding line in which the upper part of the front of the vehicle body is inclined backwards, the lens of the headlight attached to the front of the car body is also shaped so that the upper part of the lens is in line with the molding line. It has a shape that slopes toward the back side. Fig. 1 shows a headlight a having such a shape, and b indicates a lens whose upper part is inclined at an arbitrary angle so as to approach the light source c side, and the inner surface of the lens b has approximately half a cross section. A large number of circular concave diffusive lens elements d, d... are formed. The lens element d in the conventional lens has its generatrix extending in the vertical direction of the lens b, and the conventional lens b has a structure in which a large number of such lens elements d are arranged side by side on the left and right. It was hot. Such lens elements d, d
For lamp a using lens b consisting of:
The light reflected substantially parallel by the reflecting mirror e is distributed by the lens b as shown in FIG. still,
In FIG. 2, V is a vertical line passing through the center of the track, and H is the center line of the track. Note that the same representation as in FIG. 2 will be used when showing the light distribution thereafter.

The light reflected by the reflecting mirror e and traveling parallel to the optical axis XX has a light distribution h in which both side parts h' and h' are curved toward the front side. This light distribution h provides good illumination on the near side, but has the drawback that illumination on the road shoulder in front of the road is insufficient. Originally, vehicle headlights were
Since a light distribution that can evenly illuminate the front and near side of the road and the road shoulder, that is, the light distribution i surrounded by the broken line in the figure, is required, the lens elements d, which form such a light distribution h, are required. The headlight lens b consisting of d, . . . is inappropriate.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a new lens for a vehicle headlamp that can provide a vehicle headlight that can evenly illuminate the road and road shoulder in front of the road and on the near side. , the upper part or the lower part is inclined toward the back side of the lens, and has at least two regions on the left and right sides of the optical axis, and the two regions are inclined to opposite sides in the lateral direction. forming a plurality of lens steps, each of the lens steps having a
It is characterized by being composed of two types of lens elements with different curved surfaces on the left and right sides.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Details of the lens of a vehicle headlamp according to the present invention will be described below with reference to embodiments shown in the accompanying drawings.

FIG. 3 shows an example of a lens according to the present invention. 1 indicates a lens, and this lens 1 is tilted at an arbitrary angle θ° so that the upper part approaches the light source 2 side, that is, toward the back side of the lens, and the inner surface of the lens 1 is a roughly V-shaped area in the center. The lens step 4 is divided into three regions: 3 and two regions 4L and 4R connected to the left and right, and each of the left and right regions 4L and 4R includes a large number of lens steps 4 having diffused irradiation properties.
1, 4l... and 4r, 4r... are formed. Therefore, each lens step 4l, 4l...
, 4r, 4r, . . . have their upper portions inclined at the angle θ° toward the back side of the lens, and furthermore, the upper portions of each of these lens steps are laterally inclined to opposite sides. That is, area 4
The lens steps 4l, 4l, . With the X'-X' axis passing through the center of the step in a direction parallel to the optical axis XX of light source 2 as an axis, the upper part moves away from the light source 2 side, that is, to the left in the lateral direction of the lens. The lens step 4 is rotated by an angle φ°.
l, 4l...The upper part is inclined toward the back side of the lens and to the left side in the lateral direction. On the other hand, the lens steps 4r, 4r, . . . formed in the region 4R are set at an arbitrary angle θ° (this is the The optical axis X-X'-
The upper part of the lens moves away from the light source 2 side with the (the same angle), whereby the lens steps 4r, 4r
... The upper part of the segment is inclined toward the back side of the lens and to the right side in the lateral direction. Then, by horizontally cutting the upper and lower parts of each of the two-dimensionally inclined segments, a vertically elongated substantially parallelogram lens step 4l, as shown in the figure, is formed.
4l... and 4r, 4r... are obtained.

Further, each lens step 4l and 4r having such an inclination condition is composed of two types of lens elements each having a different curved surface on the left and right sides.
Although this configuration is also shown in the cross-sectional shape shown in FIG. 3B, it will be explained in detail with reference to FIG. 4. In the lens 1 shown in FIG. 4, only one of the lens steps 4l, 4l, . Although only one of the lens steps 4r, 4r, . . . formed in the lens steps 4r, 4r, .
r... have the same configuration. And the lens steps 4l, 4l in Fig. 4...
, 4r, 4r, . . . have already been three-dimensionally drawn in a state where they are tilted in the two-dimensional direction described above. or,
The axes Y-Y, Z-Z, and X'-X' in the figure are the same axes as the Y-Y, Z-Z, and X'-X' in FIG. 3, respectively. In the figure, 5, 5 indicates a virtual boundary surface extending in the vertical direction formed by the Y-Y axis and X'-X', and this boundary surface 5, 5 naturally passes through the center of each lens segment. The lens steps 4l and 4r are formed with two types of lens elements 4la and 4lb and 4ra and 4rb having different curved surfaces on the left and right sides, respectively, with these boundary surfaces 5, 5 as boundaries. That is, in the lens step 4l, a convex lens element 4la is formed on the left side (as viewed from the back side of the lens) with a vertical boundary surface 5 passing through the center thereof as a boundary, and a concave lens element 4lb is formed on the right side. On the other hand, in the lens step 4r, the vertical boundary surface 5 passing through the center is the boundary (as viewed from the back of the lens).
A concave lens element 4ra is formed on the left side, and a convex lens element 4rb is formed on the right side. The two different lens elements 4la, 4lb or 4ra, 4rb formed on the left and right sides of each of these lens steps have different cross-sectional shapes depending on their vertical traversal positions, and each center portion shown in the figure As is clear from the cross section (shaded surface) and the upper and lower end surfaces, the cross-sectional shape of the convex lens element 4la formed on the left side of the boundary surface 5 in the lens step 4l becomes smaller from the top to the bottom. , conversely, the cross-sectional shape of the concave lens element 4lb formed on the right side of the boundary surface 5 becomes larger as it goes from above to below, and in the lens step 4r, the concave lens element 4ra formed on the left side of the boundary surface 5 becomes larger from above. The cross-sectional shape of the convex lens element 4rb formed on the right side of the boundary surface 5 becomes smaller as it goes downward from the top. These reasons need not be stated again, but each lens step 4l, 4r is tilted in the left-right direction and is divided into left and right by a vertical plane passing through the center of the segment, and within each of these left and right divisions. This is because lens elements having different curved surfaces are formed.

Furthermore, each lens element 4la, 4 formed on the left and right for each lens step 4l and 4r described above.
lb, 4ra, and 4rb have a cross-sectional shape in which each half of a convex lens and a concave lens are combined as shown in FIG. In FIG. 5, 6 indicates a convex cylindrical lens, and 7 indicates a concave cylindrical lens. Xa
-Xa is the optical axis of each lens 6 and 7, which is the axis connecting the center of each lens and the vertex O of the curved surface;
If each lens 6, 7 is divided into left and right halves along the Xa-Xa line, the convex lens 6 will have a semi-convex lens chip 6a with a curved surface only on the left side from the apex O, and a semi-convex lens chip 6b with a curved surface only on the right side from the apex O. In the concave lens 7, a semi-concave lens chip 7a having a curved surface only on the left side from the apex O, and a semi-concave lens chip 7a having a curved surface only on the right side from the apex O.
b is obtained. That is, the two types of left and right lens elements 4la, 4lb and 4ra, 4rb formed for each of the lens steps 4l and 4r move these half lens steps 6a, 6b and 7a, 7b to the apex O of their respective curved surfaces. The cross-sectional shape is such that these are connected and combined on the ridgeline of the boundary surface 5. That is, in the lens step 4l, a semi-convex lens chip 6a shown in FIG. 5 is attached to the left convex lens element 4la, and a semi-concave lens chip 7b shown in FIG. In the lens step 4r, the left concave lens element 4ra is provided with a semi-concave lens chip 7a shown in FIG. 5, and the right convex lens element 4rb is provided with a semi-convex lens chip 6 shown in FIG.
b is obtained by connecting each vertex O on the ridgeline of the boundary surface 5.

Each lens step 4l formed in this way,
When parallel light rays are incident on 4l, . . . and 4r, 4r . In FIG. 4, when parallel light is made incident on the central cross section (shaded surface) of the lens step 4l, a distant screen (V-H
The irradiation line 8l is projected by condensing light from the V line on the screen) to the right side, and when parallel light is incident, for example, on the central cross section (shaded surface) of the lens step 4r, the V line of the screen is projected. The irradiation line 8r is projected by focusing the light on the left side. In other words, the light emitted from each lens step 4l, 4l... formed on the left side of the optical axis XX of the light source 2 crosses the optical axis XX and forms a vertical line V on the XX line. Each lens step 4r, 4r condenses light on the right side of the line, and conversely is formed on the right side of the optical axis
-The X-rays are crossed and focused on the left side of the V-ray. This is because, as described above, each of the left and right lens steps 4l, 4l, . . . and 4r, 4r, . Each of the irradiation lines 8l and 8r has one end in contact with the H line, and has an extremely gentle curve that is close to a straight line and roughly follows the H line.
Therefore, the lens steps 4l, 4l, . . . and 4r, 4 projecting such irradiation lines 8l, 8r.
If r... is formed separately into the regions 4L and 4R, it will be reflected by the reflecting mirror 9, and the optical axis
The light traveling parallel to -X can obtain a light distribution 10 as shown in FIG. 6, which sufficiently irradiates the lane and road shoulder in front of the lane and on the near side of the lane.

Note that an appropriate lens step is provided in a region of the lens 1 other than the regions 4L and 4R, that is, region 3.

As described above, in the lens of the vehicle headlamp of the present invention, the upper part or the lower part is inclined toward the back side of the lens, and has at least two regions on the left and right sides of the optical axis. 2
In one region, a large number of lens steps are formed which are inclined to opposite sides in the lateral direction, and each of the lens steps is composed of two types of lens elements having different curved surfaces on the left and right sides, so that the lens surface The light emitted from the left and right areas of the screen forms a light distribution that roughly follows the horizontal line, respectively.
To provide a vehicle headlamp that can illuminate the road and the road shoulder in front of the road and on the near side evenly well, obtain the light distribution necessary for a headlamp, and have excellent visibility.

FIG. 7 shows a second embodiment 1a of a lens for a vehicle headlamp according to the present invention, which differs from the lens 1 in the first embodiment in that each lens chip 4l,
Since only some of the lens elements in 4l... and 4r, 4r... are different, only those different points will be explained, and the same reference numerals will be given to other parts that are the same as in the first embodiment. The explanation will be omitted. In this embodiment, each lens element of each lens step 4l, 4l . . . and 4r, 4r . With this also, it is possible to obtain light similar to the light distribution 10 shown in FIG. 6 above.

Further, FIG. 8 shows a third embodiment 1b of the lens for a vehicle headlamp of the present invention, in which each lens step 4l, 4l... is similar to the case in FIG. 7 above.
The only difference is that the lens elements 4r, 4r, . . . , 4r, 4r, .
This also makes it possible to obtain a light distribution similar to the light distribution 10 shown in FIG. 6 above.

Furthermore, FIG. 9 shows a fourth embodiment of the lens for a vehicle headlamp according to the present invention. This lens 1c
In this example, regions 4L and 4R are provided on a portion of the left and right sides thereof. In this way, in the lens according to the present invention, it is not necessary to configure most of the lens by the lens steps 4l, 4l..., 4r, 4r... as described above, and these lens steps 4l, 4l..., The regions 4L and 4R in which 4r, 4r, . . . are formed may be partially formed.

In addition, in geometric optics, a "plane" is a "curved surface".
In this specification, "curved surface" is used to include "plane".

[Brief explanation of the drawing]

Figure 1 shows an example of a conventional lens, where A is a rear view, B is a cross-sectional view taken along line B-B in figure A, C is a cross-sectional view taken along line C-C in figure A, and Figure 2 is a cross-sectional view taken along line C-C in figure A. 1 is a light distribution diagram when the lens shown in FIG. C is a sectional view along the Y-Y line shown in Figure A, Figure 4 is a perspective view of the main part of the lens shown in Figure 3 with a part cut away, and Figure 5 is a convex cylindrical lens and a concave cylindrical lens. FIG. 6 is a light distribution diagram when the lens of the present invention shown in FIG. 3 is used, FIG. 7 is a cross-sectional view showing the second embodiment of the lens of the present invention, and FIG. FIG. 9 is a cross-sectional view showing a third embodiment of the lens of the present invention, and a rear view of the fourth embodiment of the lens of the present invention. Explanation of symbols, 1...Lens, 1a...Lens,
1b... Light source, 4L... Slanted region, 4R... Slanted region, 4l, 4r... Lens step, 5... Boundary line, 4la, 4lb, 4ra, 4rb... Lens element.

Claims (1)

[Claims] 1 The upper part or the lower part is inclined toward the back side of the lens, and has at least two regions on the left and right sides of the optical axis, and each of the two regions is inclined to the opposite side in the lateral direction. A lens for a vehicle headlamp, characterized in that a large number of lens steps are formed, and each of the lens steps is composed of two types of lens elements having different curved surfaces on the left and right sides thereof.