JPH0714405A - Head lamp for automobile - Google Patents

Abstract

PURPOSE:To provide light distribution patterns for right-side and left-side travels by forming a projection pattern by use of a reflecting mirror and forming a lens step on a front lens surface. CONSTITUTION:The reflective surface of a reflecting mirror 1 is sectioned into a region 3 located on the upper side of a horizontal plane including a main optical axis and a region 4 located on the lower side below the region 4. The projected image of a filament 8 due to the region 3 is located near or below a horizontal cut line 11, and the projected image due to those regions 4CRU, 4CRD, 4CLU, and 4CLD of the region 4, which are near the horizontal plane including the main optical axis of the reflecting mirror, contributes to the formation of an inclined cut line 10 and a line 11. The projection pattern of the reflecting mirror 1 is a projection pattern which is symmetrical about its vertical center line, with the lines 10R, 11R and the lines 10L, 11L being on the right and left sides, respectively. A lens step is formed in a range of a front lens corresponding to the region 4CRU or 4CLU, to thereby direct the light contributing to forming one inclined cut line of the projection pattern of the reflecting mirror, downwardly from the horizontal cut line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light distribution pattern of a passing beam, in which a reflecting surface is formed in advance so as to obtain a pattern obtained by combining a right-hand traffic pattern and a left-hand traffic pattern. The present invention aims to provide a novel automotive headlamp in which a reflecting mirror can be made common by selecting any one of the patterns depending on the lens step formed in (1).

[0002]

2. Description of the Related Art The basic structure of an automotive headlight for a low beam is a coiled filament near the focal point of a rotating parabolic reflector whose central axis is along the optical axis of the reflector. Is arranged as described above (so-called C8 type filament arrangement), and a shade for forming a cut line (or cutoff) in the light distribution pattern is arranged below the filament and is arranged in front of the reflecting mirror. A diffusion lens step is formed on the front lens.

However, the method of defining the cut line by the side edge of the shade has a drawback that the light flux utilization rate is low because much light is blocked by the shade.

In order to overcome this, the headlamp is made narrower (that is, the vertical width of the lamp is made smaller) and slanted (the angle formed by the front lens with respect to the vertical axis, so-called slant). In order to meet the requirement of (increasing the angle), a method of transferring the light distribution control function, which has been performed by forming a lens step to the front lens up to then, to the reflecting mirror is adopted. The curved surface is designed (for example, the reflecting surface is formed as a composite surface including a large number of small reflecting areas).

[0005]

By the way, the light distribution pattern relating to the passing beam of the vehicle headlight is defined according to the road traffic regulations of each country, and the pattern for right-hand traffic and the pattern for left-hand traffic. With and, the relationship between the left and right cut lines is reversed.

Therefore, in the conventional vehicle headlamp, the reflecting mirror for right-hand traffic and the reflecting mirror for left-hand traffic must be separately designed according to the destination of the headlight. ,
In addition, since it is necessary to create a manufacturing die for each of the reflecting mirrors, there are problems such as an increase in cost and troublesome parts management.

[0007]

In order to solve the above problems, the present invention has a horizontal cut line parallel to the horizontal line and an inclined cut line inclined at a predetermined angle with respect to the horizontal line. A headlight for an automobile capable of obtaining a light distribution pattern of a passing beam for right-hand side traffic or left-hand side traffic, wherein a central axis of a light source body is arranged along the optical axis, and a horizontal cut line and an inclination are provided. A symmetrical projection pattern having cut lines on both left and right sides is formed by the action of the reflecting mirror, and a lens step is formed on the front lens arranged in front of the reflecting mirror to form a projection pattern of the reflecting mirror by the lens step. The light that contributes to the formation of one inclined cut line is directed downward from the horizontal cut line.

[0008]

According to the present invention, horizontal and inclined cut lines are formed symmetrically by the reflecting mirror, which contributes to the formation of one of the inclined cut lines that is unnecessary by the lens step of the front lens provided in front of the reflecting mirror. By directing the light downward from the horizontal cut line, you can select either the light distribution pattern for right-hand traffic or the light distribution pattern for left-hand traffic, so there are two types of reflectors for right-hand traffic and left-hand traffic. It is not necessary to prepare, and the cost can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle headlight according to the present invention will be described below with reference to FIGS. The illustrated embodiment shows an example in which the present invention is applied to a reflecting mirror of an automobile headlamp having a square front shape.

1 to 3 show the basic surface 2 of the reflecting mirror 1. As shown in FIG.

The reflecting mirror 1 obtains a common projection pattern for right-hand traffic and left-hand traffic by utilizing the entire reflecting surface without disposing a shade below the filament, and the basic surface 2 is shown in FIG. As shown, it is composed of two divided areas 3 and 4 having different light distribution control functions.

That is, as shown in FIG. 1, the optical axis of the basic surface 2 is the "x axis" (the axis perpendicular to the paper surface, and the front direction is the positive direction), and the optical axis is orthogonal to the x axis and horizontal. The axis extending in the direction is the y-axis (the right direction in FIG. 1 is the positive direction), and the axis extending in the vertical direction orthogonal to the x-axis and the y-axis is the z-axis (the upward direction in FIG. 1 is the positive direction). When the origin of this orthogonal coordinate system is a point O, the area 3 is xy when viewed from the front.
A fan-shaped region having a central angle of 150 ° located on the upper side of the plane, and a region 4 located at the lower side of the region 3 has a central angle of 21 °.
This is a 0 ° fan-shaped area.

Of the basic surface 2, the reflecting surface used for the rectangular headlight is a portion within a rectangle 5 shown by a chain line in FIG.

A bulb mounting hole 6 is formed in the center of the basic surface 2, and a step 7 is formed at the boundary between the region 3 and the region 4.

The basic surface 2 is formed as a free-form surface that cannot be expressed exactly by algebraic expressions, and is designed by adding various parameter controls and vector controls using CAD.

Since the light distribution pattern related to the passing beam does not have left-right symmetry, designing the reflecting surface by the method of forming a free-form surface generally requires complicated surface operation.

However, as is apparent from the fact that the basic surface 2 has a shape for obtaining a projection pattern common to both right-hand traffic and left-hand traffic, each of the reflective regions 3 and 4 has its shape in the xz plane. Since they are symmetrical with respect to each other, it is possible to design a curved surface on either one of the left and right sides and form the entire surface of the basic surface 2 by a symmetric operation, thereby reducing the design burden.

The generation of a free-form surface is performed through a curve group generation process and a subsequent curved surface group generation process. The procedure will be briefly described as follows.

(1) Generation of curve group (1-a) Input of parameters First, the focal length and deformation rate of the basic parabola, the size of the tangent line,
Input the target angle of the light beam into the computer.

(1-b) Calculation of curve formula After the coordinates of the starting point and the ending point of the curve are obtained based on the basic parabola and its deformation rate, the direction of the tangent vector is obtained from the aiming angle of the ray and its magnitude is calculated. Define a free-form curve (eg,
Ferguson curve).

(2) Generation of curved surface group (2-a) Input of parameters Instructions regarding whether or not a constraint (orthogonal) condition is given to a tangent vector, a diameter of a basic ellipse, a twist vector, etc. are input to a computer. input.

The constraint condition for the tangent vector corresponds to the optical operation for aligning the central axes of the filament images, and the twisting operation for the tangent line corresponds to the optical operation for moving the filament image in the direction perpendicular to the longitudinal direction (details). For details, refer to the application of Japanese Patent Application No. 3-21430 filed by the present applicant).

(2-b) Calculation of curved surface formula: A curved surface patch (for example, Coons' bicubic patch) is generated. At that time, in determining the patch coefficient, the coordinates of the points, the tangent vector regarding the curve coordinates (the curved surface parameters u, v), the twist vector, etc. are required.

Since all the coordinates of the points and a part of the tangent vector are determined by the already obtained free curve, the rest of the tangent vector is obtained from the shape parameter of the basic ellipse, the constraint condition and the twist angle. Adjust the size and use Adi to calculate the twist vector.
The ni method, the Forrest method, or the like is appropriately used.

Generation of such a free-form surface is performed by dividing the basic surface 2 into several control sections, for example, as shown in FIG.

The region 3 is composed of two regions 3R and 3L. When viewed from the front, the region 3R is located in the first quadrant (y> 0, z> 0) of the yz plane, 3L is y
It is located in the second quadrant (y <0, z> 0) of the -z plane.

The area 4 includes six areas 4CRU and 4C.
It is composed of RD, 4R, 4CLU, 4CLD, and 4L.

Regions 4CRU, 4CRD, and 4R are regions located on the right side of the xz plane in the region 4, and are regions 4C.
The RU is a sectoral region located immediately above the xy plane, and the central angle of which is an angle corresponding to the cut line angle (15 °), and the region 4CRD is located immediately below the xy plane. , Is a fan-shaped region whose central angle corresponds to the cut line angle.

The region 4R is located immediately below the region 4CRD.

Regions 4CLU, 4CLD, and 4L are regions located on the left side of the xz plane in the region 4, the region 4CLU is located immediately above the xy plane, and the center angle is the cut line angle. The region 4CLD is a fan-shaped region having a corresponding angle, and the region 4CLD is located immediately below the xy plane, and has a center angle corresponding to the cut line angle.

The region 4L is located immediately below the region 4CLD.

FIG. 4 schematically shows a projection pattern 9 of the reflecting mirror 1 when the filament 8 is arranged along the optical axis of the reflecting mirror 1 (shown in FIG. 2). In addition, "H" in the figure
The "-H" line indicates a horizontal line, the "VV" line indicates a vertical line, and the point "o" indicates the intersection of both lines.

The projection pattern 9 has symmetry with respect to the vertical line VV.

Reference numerals 10R and 10L are inclined cut lines inclined at a predetermined cut line angle with respect to the horizontal line H-H. One slope cut line 10R is a vertical line V-V
Is a line rising to the right on the right, and the other inclined cut line 10L is a line rising to the left located on the left side of the vertical line V-V.

Reference numerals 11R and 11L denote horizontal cut lines (shown by broken lines) parallel to the horizontal line H-H, one of which is located on the right side of the vertical line V-V, and the other 11 L is a vertical line V-V. Located on the left side of.

The horizontal cut lines 11R and 11L are masked by the light below the inclined cut lines 10R and 10L.

In forming these cut lines, the tangent vector at the end point of the curved surface patch is made orthogonal to the position vector of the end point, so that the filament image projected on the screen arranged in front of the reflecting surface. By aligning the central axes in the longitudinal direction with each other or applying a twist to the curved surface, an optical curved surface operation is performed in which one side edge extending in the longitudinal direction of the filament image is aligned with each other.

5 to 7 show examples of arrangement of filament images obtained by the reflecting surface.

In the figure, "hh" line and "vv" line are set on the screen placed in front of the reflecting mirror 1, and "h-h" line and "vv" line are set.
The "h" line is a line extending in the horizontal direction orthogonal to the x axis, "v-
The "v" line indicates each line extending in the vertical direction orthogonal to the x-axis. The “vv” line corresponds to the vertical line VV in FIG. 4, but the “hh” line coincides with the horizontal line HH in FIG. 4 due to the aiming adjustment for the headlights that follow. Is set as follows.

FIG. 5 typically shows the arrangement tendency of the filament image projected by the region 3, and the filament image is located in the vicinity of or below the "hh" line and corresponds to the inclined cut line. There is no position above the imaginary lines 12, 12.

FIG. 6 shows areas 4CLU, 4CLD, 4L and 4CLU.
It shows the arrangement tendency of the filament images projected by R and 4CRD, and each filament image is arranged radially with respect to the point o.

Filament image 13 associated with region 4 CLU,
.. contribute to the formation of the inclined cut line 10R, and the filament images 14, 14, ... Related to the region 4CRD.
.. contributes to the formation of the horizontal cut line 11L.

FIG. 7 shows areas 4CRU, 4CRD, 4R, 4
6 shows the arrangement tendency of the filament images projected by the L and 4 CLDs, each filament image is arranged radially with respect to the point o, and is symmetrical with respect to the arrangement of the filament images in FIG. 6 with respect to the “vv” line. Have.

Filament image 15 associated with region 4 CRU,
.. contribute to the formation of the inclined cut line 10L, and the filament images 16, 16, ...
.. contributes to the formation of the horizontal cut line 11R.

The projection pattern 9 formed by the reflecting mirror 1 is a combination of the patterns formed by the respective areas, and as shown in FIG. 4, inclined cut lines 10R and 10R are formed on the left and right of the vertical line V-V.
L and horizontal cut lines 11R and 11L,
A part of the projected pattern by the region 3 mainly contributes to the formation of the central portion of the luminous intensity in the light distribution pattern 9, and
Part of the projected pattern (that is, area 4C
RU, 4CRD, 4CLU, 4CLD pattern)
Contributes to the formation of cut lines in the light distribution pattern 9.

FIG. 8 is a front view schematically showing a front lens arranged on the front surface of the reflecting mirror 1. (a) shows a front lens 17 for right-hand traffic, and (b) shows a front lens for left-hand traffic. The lens 18 is shown.

Area 4CR of the reflecting surface of the front lens 17
A lens step having a function of directing light downward is formed in the range 17a corresponding to U.

As shown in FIG. 4, the projection pattern 9 formed by the reflecting mirror 1 has inclined cut lines 10R and 10L on both sides of the vertical line V-V, so that one inclined cut line is unnecessary. This is because it is necessary to direct light that contributes to the lower side of the horizontal cut line.

As a result, the light distribution pattern 19 for right-side traffic as shown in FIG. 9A is obtained. As is clear from the comparison with FIG. 6, the region 4CL is used for forming the cut line.
U, 4CRD is involved.

In the case of the front lens 18, considering the left-right symmetry, the range 18 corresponding to the area 4CLU of the reflection surface is considered.
It can be seen that a lens step is formed which has the effect of directing light downwards at a.

As a result, the light distribution pattern 20 for right-side traffic as shown in FIG. 9B is obtained. As is clear from the comparison with FIG. 7, the cut line is formed in the area 4CR.
U, 4 CLD is involved.

As described above, the reflecting mirror 1 forms the common projection pattern 9 for right-hand traffic and left-hand traffic, and one of the inclined cut lines is set below the horizontal cut line by the lens step formed on the front lens 17 or 18. The light distribution pattern 19 for the right-hand traffic and the light distribution pattern 20 for the left-hand traffic can be selected by lowering the light distribution pattern.

[0053]

As is apparent from the above description, according to the present invention, a reflecting mirror is used so that the passing beam can be adapted to both the right-hand side passing pattern and the left-hand side passing light distribution pattern. The horizontal and slanted cut lines are formed symmetrically, and the light contributing to the formation of one slanted cut line that is unnecessary due to the lens step of the front lens provided in front of the reflecting mirror is directed below the horizontal cut line. Since you can select either the light distribution pattern for right-hand traffic or the light distribution pattern for left-hand traffic, it is possible to use a common reflecting mirror for both light distribution patterns and reduce costs. it can.

The reflecting surface of the reflecting mirror is divided into a first region located above the horizontal plane including the main optical axis and a second region located below the first region. , First
The projected image of the light source body by the area of is located below the slant cut line, and the projected image of the light source body by the area of the second region that is close to the horizontal plane including the main optical axis of the reflecting mirror is the horizontal cut line and the slant cut line. By forming a lens step in a region of the front lens corresponding to a region of the second region close to the horizontal plane including the main optical axis of the reflecting mirror, the lens step is formed so as to contribute to the formation of the line. If the light that contributes to the formation of one of the inclined cut lines is directed downward from the horizontal cut line, it corresponds to the range between the cut line formation in the reflecting mirror and the lens step formation range in the front lens. Relationships can be established, and light distribution design becomes easy.

[Brief description of drawings]

FIG. 1 is a front view of a basic surface of a reflecting mirror according to the present invention.

FIG. 2 is a side view of a basic surface of a reflecting mirror according to the present invention.

FIG. 3 is a front view showing a light distribution control section regarding a basic surface of a reflecting mirror according to the present invention.

FIG. 4 is a diagram schematically showing a projection pattern of a reflecting mirror.

FIG. 5 is a diagram showing a tendency of arranging filament images in a region 3.

FIG. 6 is a diagram showing a tendency of arranging filament images in a region of the reflecting mirror that is involved in formation of a right-hand side light distribution pattern.

FIG. 7 is a diagram showing an arrangement tendency of filament images in a region of the reflecting mirror, which is involved in forming a left-side traffic distribution pattern.

FIG. 8 is a front view schematically showing a front lens,
(A) shows the front lens for right-hand traffic, (b) shows the front lens for left-hand traffic.

FIG. 9 is a diagram schematically showing a light distribution pattern, (a)
Shows a pattern for right-hand traffic, and (b) shows a pattern for left-hand traffic.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reflector 3 1st area 4 2nd area 8 Light source body 10R, 10L Inclination cut line 11R, 11L Horizontal cut line 17, 18 Front lens 17a, 18b Range

Claims (2)

[Claims] 1. A light distribution pattern of a right-hand or left-hand passing beam which has a horizontal cut line parallel to a horizontal line and an inclined cut line inclined at a predetermined angle with respect to the horizontal line. A headlight for an automobile, which can be (a) the central axis of the light source body is arranged along the main optical axis of the reflecting mirror, and (b) a left and right side having a horizontal cut line and an inclined cut line on both left and right sides. A symmetrical projection pattern is obtained by the reflecting mirror, and (c) a lens step is formed in the front lens arranged in front of the reflecting mirror, and the one tilt cut line in the projection pattern (b) is formed by the lens step. The vehicle headlight is characterized in that the light contributing to is directed downward from the horizontal cut line. 2. The vehicle headlamp according to claim 1, wherein (a) a first region in which the reflecting surface of the reflecting mirror is located above a horizontal plane including the main optical axis, and the first region. And (b) that the projection image of the light source body by the first region is located near or below the horizontal cut line, and (c) That the projected image of the light source body by the area close to the horizontal plane including the main optical axis of the reflecting mirror in the second area contributes to the formation of the horizontal cut line and the inclined cut line, and (d) the reflecting mirror in the second area. A lens step is formed in the range of the front lens corresponding to the area close to the horizontal plane including the main optical axis of, so that the light that contributes to the formation of one inclined cut line in the projection pattern of the reflecting mirror is more than the horizontal cut line. I tried to go down, A characteristic automotive headlight.