JPH09306220A - Reflector for vehicle lighting - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To make a light flux reflected by a reflector have a desired light distribution characteristic without dimming by a front lens.
In addition, a step formed between a large number of reflecting surface blocks forming the reflector is reduced to prevent or reduce the occurrence of glare (stray light) due to the step and other problems caused by the step. A large number of reflecting surface blocks B1, B2 to B44, each having a polygonal (preferably hexagonal) outer peripheral contour.
B45 is composed of a free-form surface. The above-mentioned free-form surface is not a rotating surface having a single optical axis, but minute reflecting elements are arranged and adjacent reflecting elements are changed steplessly (or to the extent that it can be regarded as stepless) A collection of reflective surfaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector for a vehicular lamp, and more particularly to a reflector having a front lens which is a plain lens or a lens close to a plain lens.

[0002]

2. Description of the Related Art For example, a classical basic structure of a vehicle headlight or a fog lamp is that a light source bulb is arranged near the focal point of a rotating parabolic reflector and a parallel light flux reflected by the reflector is converted into a prism lens. The front lens made of light is dimmed to form a desired light distribution pattern. As a recent trend of improvement, a technique for making the front lens a plain lens or a lens close to a plain lens has been studied. That is, by improving the shape of the reflector, the reflected light flux of the reflector is devised so as to form a substantially desired light distribution pattern. According to the reflector thus improved, the optical load on the prism provided on the front lens is light, and the manufacturing cost of the front lens is reduced.

FIG. 5 shows a known example of a reflector of a vehicular lamp, (A) is a front view of the reflector, and (B) is a light distribution pattern chart when a screen is irradiated with the light flux reflected by the reflector. is there. The reflector 5 shown in FIG. 5A is divided into a plurality of partial mirrors like a1 to a25. However, in the present invention, dividing the reflecting surface means not assuming that the actual reflector is cut, but assuming a virtual boundary line at the design stage. Also, in the present invention, the word "many" in the word "many"
Is an integer of 3 or more, like “poly” in the terms polygon and polyhedron. Reference numeral 6 shown in FIG. 5A indicates the position of the light source. The 16 reflected light beams emitted from the light source at this position and reflected by each of the 16 partial mirrors a1 to a31 are combined to illuminate the illumination area E shown in FIG. The reflector 5 of this example is configured for left-hand traffic, and the illumination area E does not illuminate above the horizontal line H-H on the opposite lane side (right side). For example, the light flux reflected by the partial mirror a24 in FIG. 7A illuminates the area E24 shown in FIG.
The reflected light flux illuminates the area E14 by 4. A shade 7 is provided in order to block direct light that travels toward the front of the lamp without being reflected by the reflector 5. Each of the prior art partial mirrors described above with reference to FIG.
It is an independent reflecting element having an optical axis and a focal point.

[0004]

When the partial mirrors, which are independent reflecting elements and are independent of each other, are arranged as in the conventional example described above, the step formed between the adjacent partial mirrors is relatively large. . If the above step exists, the light beam reflected by the step becomes glare (stray light), which causes a problem that the light distribution characteristic is deteriorated.

The present invention has been made in view of the above circumstances, and provides a reflector for a vehicular lamp, which is a reflector which can obtain a reflected light flux having a desired light distribution characteristic and which has a reduced step. The purpose is to do. By reducing the step, it can be expected that the light distribution characteristic is improved, the manufacturing cost is reduced, and the die strength is improved.

[0006]

The basic principle of the present invention created to achieve the above-mentioned object will be briefly described with reference to FIG. 1 corresponding to one embodiment thereof. The reflective surface block is divided into a large number of reflective surface blocks B1 to B45, and the outline shape of each reflective surface block is formed into a polygon (basically a hexagon). However, due to the restriction of the contour shape of the entire reflecting surface of the reflector 9, the reflecting surface block in the peripheral portion has a shape in which a part of the hexagon is cut off.

Then, the reflecting surfaces of each of the above-mentioned many reflecting surface blocks are constituted by free-form surfaces. The free-form surface in the present invention means "it is not a single rotating surface and therefore does not have a single optical axis, and a large number of minute reflecting elements are arranged to make the change between the reflecting elements stepless, or It is a reflective surface that is multi-stepped and fine enough to be regarded as stepless.In the past, it was impossible and impossible to construct such a reflective surface block with high precision, It has become possible to industrially manufacture today by calculating and designing with, and grinding a mold with an NC controlled machine tool. Based on the principle described above, the configuration of the present invention has a large number of reflective surfaces. 3. The invention according to claim 2, wherein each of the plurality of reflecting surface blocks is a free-form surface, and each of the plurality of reflecting surface blocks has a polygonal shape. Is the structure of the invention of claim 1 A plurality of polygonal reflecting surface blocks are arranged around the light source position, and each of the boundary lines between two adjacent reflecting surface blocks among the plurality of reflecting surface blocks is centered on the light source position. , And is almost radial.

[0008]

1 shows an embodiment of a reflector for a vehicle lighting device according to the present invention, in which each of a large number of reflecting surface blocks is marked with a boundary line which cannot be visually recognized and an identification code is entered. FIG. Edge 9 around the reflecting surface of the reflector 9 of the present embodiment
a is a polygon in the front view (a regular octagon in this example)
And the center point is the light source position 6, the light source bulb is covered and hidden by the shade 7, and one of the apex angles of the peripheral edge polygon is located below the light source position 6. ing. The reflecting surface of the reflector 9 is divided into a large number of reflecting surface blocks B1 to B45, each of which is formed into a free curved surface.

The basic shape of the large number of reflecting surface blocks B1 to B45 is a hexagon having two vertical parallel sides,
The reflecting surface block that does not interfere with the edge 9a around the reflector has the above-described basic shape. For example, considering the reflecting surface block B2, the basic shape is obtained by adding a trapezoid B2 'drawn by an imaginary line. This is a pentagon drawn by a solid line, in which a part of the reflecting surface block B2 having a basic shape is cut off by an edge 9a around the reflector.
In this way, each reflecting surface block in this embodiment has a polygonal shape.

Although a step is formed at the boundary between the reflecting surface blocks, a minute reflecting element is arranged as compared with the reflecting surface having a single optical axis like the partial mirror in the conventional example. Since the reflective surface block that has a high degree of design freedom,
Since it is relatively easy to configure the step difference to be small and the boundary line between the reflecting surface blocks is shortened for the reason described below, the adverse effect caused by the step difference is further reduced. That is, FIG. 2 is shown in order to explain the length of the boundary line between the reflecting surface blocks which form the reflector, and (A1) assumes that the reflecting surface block has a rectangular contour for comparison. Virtual partial front view,
(A2) is a schematic perspective view of the same, (B1) is a partial front view of the reflector in the above-described embodiment of FIG. 1, and (B2) is a schematic perspective view of the same. Compared to the length dimension L ₁ of the boundary line between the rectangular reflective surface blocks b13 and b14, the hexagonal reflective surface blocks B13 and B
It is understood that the length dimension L ₂ of the boundary line between 14 and 14 is short.

FIG. 3 is a front view drawn to facilitate understanding of the features of the reflector in the embodiment shown in FIG. 1 above. Six hexagonal reflecting surface blocks B12, B13, B24, B33, B32, and B22 surrounding the light source position 6 are annularly arranged. Of these 6 reflecting surface blocks, a total of 6 boundary lines k _{1 to} k ₆ are formed between adjacent reflecting surface blocks, and these boundary lines are substantially radial around the light source position 6. It is set so that it is not horizontal.

Considering the technical meaning of the above-mentioned "substantially radial shape", it is now assumed that six reflecting surface blocks which are annularly arranged so as to surround the position of the light source are positive 6 of the same size. If it is a polygon, the six boundary lines can be set in a completely radial pattern. If the boundary line becomes radial, the amount of light incident from the light source on the stepped surface including the boundary line becomes small enough to be regarded as zero (the incident light amount is not a perfect point light source. Not completely zero, but much less). Therefore, the generation of stray light due to the step is almost completely suppressed. Further, since the boundary line is inclined with respect to the horizontal plane (not horizontal in the front view), the generation of stray light is further suppressed.

Regarding the shapes and dimensions of the six hexagonal reflecting surface blocks surrounding the light source position 6, in order to obtain desired light distribution characteristics, it is designed to intentionally increase or decrease the area as described later. May be set to, or may be corrected to be vertically long or horizontally long, so the six boundary lines k ₁
There may be cases where ~ k ₆ cannot be set exactly in the radial direction, but flare caused by the step is set if the directions of these boundary lines are set as close as possible to the radiation while considering the balance with other design conditions. Can be suppressed. Further, for example, in order to reduce glare due to a step at the boundary line k ₂ , the reflecting surface near the boundary line of the reflecting surface block B24 is higher than the reflecting surface near the boundary line of the reflecting surface block B13 (in the front direction on the paper surface). It is desirable to position it. As a result, the step surface comes into the shadow with respect to the light flux from the light source position 6, and glare due to the step is prevented.

In the present embodiment (FIG. 3), among the six hexagonal reflecting surface blocks surrounding the light source position 6, the reflecting surface block B located diagonally below the light source position 6 is shown.
32 and B33 are substantially regular hexagons, and when compared with this as a reference, the obliquely upper reflecting surface blocks B12 and B13 are horizontally long and have a small area. The left and right reflective surface blocks B22 and B24 have large areas. The effect of such a configuration will be described. Compared to the case where the light beams emitted from the light source position 6 and incident on the left and right reflecting surface blocks B22 and B24 are in a substantially horizontal direction, the reflecting block B on the obliquely upper side is described.
Since the light fluxes incident on B12 and B13 have an elevation angle in an upward direction with respect to the horizontal direction, this is defined as the reflection surface block B1.
If an attempt is made to form a substantially parallel light flux in the horizontal direction at 2 and B13, glare in the upward direction is likely to occur. (Note) This is a glare that is not caused by a step. Therefore, in the present embodiment, the reflective surface blocks B12 and B13 that easily cause glare.
The area of the reflecting surface blocks B22 and B24 on the left and right sides where the glare is less likely to occur is set to be large, and the area of the reflector is reduced to reduce the occurrence of glare.

Next, for example, the same as the reflection surface block B13.
Considering the boundary line k between 14, in order to reduce negative effects due to the step formed at the boundary line k _7, the boundary line k ₇ is short, it is desirable. As the most basic configuration of the present invention, since the reflecting surface block B13 is hexagonal (compared with, for example, a quadrangular shape), the vertical boundary line is shortened. In the embodiment, the reflective surface block B13 is formed horizontally longer than the regular hexagon.

The reflector 9 of the present embodiment is contoured in a shape in which the periphery of the reflecting surface is cut into an octagon, and one of the apex angles is located below the light source position 6. . This creates a novel design and
It is possible to obtain an excellent light distribution characteristic as described in detail below with reference to. FIG. 4 is a light distribution pattern chart when the screen is illuminated by the reflected light flux formed by the reflector of the embodiment shown in FIG. The reflected luminous fluxes of the 23 reflecting surface blocks B1 to B45 shown in FIG. 3 are combined to form an appropriate illuminance distribution in the illumination area E '. Of the 23 illumination areas formed by the light flux, three representative ones will be described. The reflection surface block B33 forms a horizontally long light distribution area E33 below the horizontal line H-H. Since the reflecting surface block B33 is close to the light source position 6, it receives a large amount of light per unit area and forms a reflected luminous flux having a high luminous flux density. Since this large amount of reflected light flux forms a light distribution area E33 in which the horizontal direction H-H is largely diffused below the horizontal line H-H, a horizontally long hot spot is formed near the intersection O between the horizontal line H-H and the front vertical line V-V. (Maximum illumination area, not shown)
Convenient to form.

(Refer to FIG. 3) The reflecting surface block B43 in this embodiment has a vertically long hexagonal shape, and the reflected light flux of this block forms the light distribution area E43 of FIG. Assuming now that the bottom side of the contour of the reflector 9 is cut off like an imaginary line 10, the lower half of the reflecting surface block B43 is cut off, so that the light distribution characteristic chart of FIG. The amount of light distributed to the light area E43 decreases. For example, in the light distribution pattern of the conventional example shown in FIG. 6B, the amount of light distribution in the area E24 is not sufficient, so that the dark zone 8 indicated by the parallel hatching appears near the bottom of the illumination area E. When the front of the traveling road surface is illuminated with a headlight having a dark zone 8 as shown in FIG. 6 (B), the presence of light unevenness is felt on the front side of the central portion of the illumination area E, and the visibility of the traveling road surface is improved. Lower. On the other hand, when a sufficient amount of light is distributed near the bottom of the illumination area E ′ as shown in FIG. 4 (this embodiment), light unevenness does not occur.

As described above with reference to FIG. 3, the area of the reflecting surface block B43 is increased by making the contour of the outer peripheral portion of the reflecting surface of the reflector 9 a regular octagon, and the amount of light reflected by the reflecting surface block 43 is increased. However, the area of the reflecting surface block B44 adjacent to the reflecting surface block 43 also increases (because the contour is a regular octagon) and the amount of reflected light also increases. The reflected light flux from this reflecting surface block B44 is shown in FIG.
At, a light distribution area E44 is formed. In this way, the light distribution area having a sufficient amount of light is superimposed near the bottom of the illumination area E ', so that there is no risk of light unevenness due to insufficient light amount, and a desired light distribution pattern is formed.

[0019]

As described above, the configuration and function of the embodiment of the present invention are clarified, and according to the present invention,
It is possible to form a desired light distribution pattern by superimposing the light fluxes reflected by each of the multiple reflection surface blocks, and each reflection surface block has a polygonal shape or a part of the polygonal shape is cut out. Since the shape is formed, the length of the side that causes the step is shortened, and the adverse effect caused by the step is reduced. Furthermore, since the above-mentioned reflective surface block is a free-form surface composed of a large number of minute reflective elements (rather than a single curved surface such as a paraboloid of revolution), an area illuminated by the reflected light of each reflective surface block. Not only can it be controlled by design, but also the illuminance distribution in the illuminated area can be controlled by design for each area illuminated by each reflected light. Therefore, excellent light distribution characteristics without light unevenness can be obtained.

Further, since the direction of the step formed along the boundary line between the reflecting surface blocks (the direction of the step appearing in the front view) is substantially equal to the direction of the radiation centered on the light source position, the light is emitted from the light source. The amount of light entering the step is extremely small. Therefore, the amount of light that is reflected by the step and becomes stray light is small, and there is almost no risk of disturbing the desired light distribution pattern with stray light.

[Brief description of drawings]

FIG. 1 is a front external view showing a first embodiment of a reflector for a vehicle lamp according to the present invention, in which a plurality of reflecting surface blocks are each marked with a boundary line which is invisible to the naked eye and an identification code is entered. .

FIG. 2 is shown in order to explain the length of the boundary line between the reflecting surface blocks forming the reflector, and (A1) is drawn for comparison in the case where the reflecting surface block has a rectangular contour. 2A is a schematic partial perspective view, (B1) is a partial front view of the reflector in the embodiment shown in FIG. 1, and (B2) is a schematic perspective view. Is.

FIG. 3 is a front view drawn to facilitate understanding of characteristics of the reflector in the embodiment shown in FIG. 1 above.

FIG. 4 is a light distribution pattern chart when a screen is illuminated by a reflected light beam formed by the reflector of the embodiment shown in FIG. 3 described above without light adjustment by a front lens.

FIG. 5 shows a known example of a reflector for a vehicle lamp,
(A) is a front view of the reflector, and (B) is a light distribution pattern chart when the screen is irradiated with the light flux reflected by the reflector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vehicle lighting fixture, 2 ... Reflector, 3 ... Light source bulb, 4
... transparent front lens, 5 ... reflector, 6 ... light source position, 7 ... shade, 8 ... dark zone, 9 ... reflector, 9a ... edge around reflector, 10 ... virtual bottom.

Claims (5)

[Claims] 1. A reflective surface is divided into a large number of blocks, each of the plurality of reflective surface blocks is a free-form surface, and each of the plurality of reflective surface blocks has a polygonal contour shape. Then, a plurality of polygonal reflecting surface blocks are arranged around the light source position, and each of the boundary lines between two adjacent reflecting surface blocks of the plurality of reflecting surface blocks corresponds to the light source position. A reflector for a vehicular lamp, which is substantially radial as a center. 2. The reflector for a vehicular lamp according to claim 1, wherein a boundary line between the reflecting surface blocks surrounding the light source position is inclined with respect to a horizontal plane. 3. The area of the reflecting surface blocks arranged to the left and right of the light source position out of the plurality of polygonal reflecting surface blocks arranged around the light source position is above the light source position. The reflector for a vehicular lamp according to claim 1 or 2, wherein the reflector is larger than the area of the reflecting surface block located below. 4. The polygonal reflecting surface block positioned above or below the light source position, wherein at least a part of the reflecting surface blocks has a horizontally long shape. The reflector for the vehicle lighting described. 5. A plurality of reflecting surface blocks are annularly arranged on the outer peripheral side of a plurality of polygonal reflecting surface blocks arranged around the light source position so as to surround the six reflecting surface blocks. And the outer peripheral contour of the annular area in which the plurality of reflecting surface blocks are arranged is polygonal, and one of the apex angles of the polygon of the outer peripheral contour is located below the light source position. 2. The method according to claim 2, wherein
A reflector for a vehicular lamp according to any one of claims 1 to 4.