JP3226391B2 - Automotive headlamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a headlamp for an automobile which can change a light distribution pattern by blocking a part of light directed to a reflector with a movable shade, and more particularly to a parabolic surface around a single light source. It has a reflective optical system using a shaped reflector, and a projection optical system using an elliptical shaped reflector, a shade for forming a clear cut line, and a projection lens, and transmits light from a light source to a parabolic reflector. The present invention relates to an automobile headlamp that changes a light distribution pattern depending on whether light is partially shielded by a movable shade or not.

[0002]

2. Description of the Related Art As this kind of prior art, Japanese Utility Model Laid-Open No.
No. 33201. This is shown in FIG.
A discharge bulb 1 which is a light source, a discharge valve position upper region 3a as a boundary (3a _1, 3a ₂₎ and the lower area 3b (3
b ₁ , 3b ₂ ), a parabolic reflector 2 having an effective reflecting surface 3, and a shade member 4 movable near the discharge portion of the discharge bulb 1 in the optical axis L direction. The member 4 is moved backward in the direction of the optical axis L so as to block the light from the discharge portion of the discharge bulb 1 toward the area 3b below the effective reflection surface, thereby forming a low beam.
Is moved forward in the direction of the optical axis L to form a traveling beam without blocking the light from the discharge portion of the discharge bulb 1 toward the effective reflection surface 3 (by the reflected light in the upper and lower regions 3a and 3b). It has become. That is, two different light distributions of the traveling beam and the passing beam can be achieved by one discharge bulb.

[0003]

However, the above-mentioned prior art
In the structure of the above, the reflected light of the parabolic effective reflection surface 3 is
Light distribution control by light distribution control step of lens (not shown)
Since the reflective optical structure is controlled, the bulb of the effective reflective surface 3 is inserted.
Area 3a near the hole (close to the center of the reflector) ₁, 3
b₁Has a large solid angle and a large amount of luminous flux, but the image is greatly expanded.
Therefore, it is not suitable for the light distribution control step formed on the front lens.
It is difficult to control the light distribution precisely, leading to the generation of glare light.
There was a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide an automobile headlamp which enables two proper light distributions of a traveling beam and a passing beam by a single light source. It is in.

[0005]

According to a first aspect of the present invention, there is provided an automobile headlamp comprising:
A first reflector having a substantially ellipsoidal shape, a second reflector having a parabolic shape provided around the first reflector, and a position near a first focal point of the first reflector; A light source provided near the focal point of the second reflector; a clear cut line forming shade provided at a position near the second focal point of the first reflector to block light upward from the optical axis; A projection lens disposed in front of the clear cut line forming shade, for projecting and distributing light reflected by the first reflector;
It is provided at a position surrounding the light source and does not block light directed to the second reflector during the formation of the traveling beam, but operates along the optical axis to block a part of the light directed to the second reflector during the formation of the passing beam. This is provided with a movable shade.

According to a second aspect of the present invention, in the vehicle headlamp according to the first aspect, the movable shade includes a shade fixing portion that blocks light traveling to a region other than the effective reflection surface of the second reflector, and a low beam. At the time of formation, it becomes a position protruding toward the reflector side of the shade fixing portion and blocks a part of the light going to the effective reflection surface of the second reflector, and at the time of forming a traveling beam, the shade movable portion becomes a position overlapping with the shade fixing portion. And is constituted by

[0007]

In the area near the optical axis of the reflector, the light distribution of which is difficult to control in the lens step because of a large solid angle and a large light flux but a large image is projected and distributed by a projection optical system having a clear cut line forming shade. And glare light is not easily formed. Also, since the solid angle is small and the luminous flux is small, but the image is small, the light distribution can be easily controlled by the lens step. Various light distribution patterns can be formed by partially blocking light directed to the reflector by the movable shade.

According to the second aspect, at the time of forming the traveling beam, the shade movable portion moved along the optical axis direction is overlapped with the shade fixed portion, so that the ratio of the light reflected by the reflector blocked by the movable shade is reduced. .

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 4 show a vehicle headlamp according to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of the headlamp, and FIG. 2 is a perspective view of a reflector housed in a lamp body. , FIG. 3 is a front view of the reflector, and FIG.
FIG. 3 is a diagram showing a light distribution pattern formed by the headlamp.

In these figures, reference numeral 10 denotes a container-shaped lamp body that opens forward, and reference numeral 11 denotes a front lens provided at a front opening of the lamp body 10.
In the lamp body 10, a reflector 20 having an effective reflection surface 21 on which aluminum is vapor-deposited is accommodated. A bulb insertion hole 12 provided in a central portion of the reflector 20 includes:
A discharge bulb 14 that emits light by discharge between the electrodes is inserted.

The effective reflection surface 21 of the reflector 20 is an ellipsoidal first effective reflection surface 2 around the bulb insertion hole 12.
2 and a parabolic second effective reflecting surface 23 extending on both left and right sides of the first effective reflecting surface 22. Surface 22, 2
3 are formed. The reflecting surface 22 contributes to both the distribution of the traveling beam and the passing beam, but the reflecting surface 23 has both the traveling beam and the passing beam by boundary lines 26 and 27 extending obliquely downward from the periphery of the valve insertion hole 12. The upper effective reflection surface 23A that contributes to the light and the lower effective reflection surface 23B that contributes only to the light distribution of the traveling beam are defined in two regions.

Reference numeral 15 denotes a discharge portion of the discharge bulb 14, and the discharge portion 15 is an ellipsoidal first effective reflection surface 2.
2 is set to be near the first focal point. A shade 1 for forming a clear cut line for a low-beam is provided at a position near the second focal point of the first effective reflection surface 22.
A projection lens 17 having an upper edge 16a of the shade as a rear focal position is disposed in front of the shade 16. For this reason, as shown by the arrow in FIG. 1, the light emitted from the discharge unit 15 is reflected by the first effective reflection surface 22, condensed at the second focal point, and then projected forward by the projection lens 17 and distributed. That is, the bulb 14 and the first effective reflection surface 2
A light distribution pattern for a low beam is formed by a projection type optical system including the second, shade 16 and projection lens 17. 4 shows a light distribution pattern Ac formed by the projection optical system. Reference numeral 18 denotes a lens holder having a U-shaped vertical section connected to the front end of the reflector for supporting the projection lens 17, and a shade 16 for forming a clear cut line is integrally formed on the lens holder 18. Is formed.

The discharge section 15 is also set so as to be located near the focal point of the parabolic second effective reflection surface 23. Light emitted from the discharge section 15 is reflected by the effective reflection surface 23. The light becomes substantially parallel to the optical axis L, and is diffused and distributed in a predetermined forward direction by the diffusion step 11a formed on the back surface of the front lens 11. That is, the bulb 14, the second effective reflection surface 23 (23A, 23B), and the lens step 11a
A light distribution pattern for a traveling beam is formed by the reflective optical system composed of. In FIG. 4, the pattern indicated by reference numeral Aa (the area indicated by oblique lines) indicates a light distribution pattern formed by the upper reflecting surface 23A, and the pattern indicated by the reference sign Ab (the area indicated by broken lines) is the distribution formed by the lower reflecting surface 23B. 3 shows a light pattern.

Reference numeral 30 denotes a thin cylindrical shade member that slides back and forth along the optical axis L. Light emitted by the discharge bulb 14 is effectively applied to the left and right sides of the cylindrical portion near the rear of the second reflector. A side opening 32 for facing is formed only on the reflection surface 23A. Symbols 30a and 30b
Indicates a front end and a rear end of the shade member 30. The shade member 30 is supported by legs 31, and a long hole 26 is formed on the lower surface of the reflector 20 so as to extend forward and backward. The legs 31 pass through the long holes 26 and are supported by a drive unit 27 fixed to the reflector 20. Have been. A drive mechanism using an electromagnetic solenoid or a motor, which is electrically controlled by a switch (not shown), as a drive unit is provided inside the drive unit 27, and can move the leg 31 back and forth in the optical axis L direction. That is, the shade member 30 has the optical axis L
In this case, the user moves back and forth in the direction, and can selectively select a front position indicated by a virtual line in FIG. 1 and a rear position indicated by a solid line in FIG.

When the shade member 30 is positioned forward (to the left in FIG. 1) as shown by the phantom line in FIG. 1, the rear end portion 30b of the shade member is located at a position forward of the discharge portion 15 and the valve discharge is performed. The light of the portion 15 is guided to the first and second effective reflection surfaces 22 and 23, and the light reflected by the two reflection surfaces 22 and 23 forms a traveling beam. That is,
The light distribution pattern Ac (for the passing beam) by the projection optical system and the light distribution patterns Aa and Ab (for the traveling beam) by the reflective optical system are combined to form a traveling beam.

As shown by the solid line in FIG. 1, when the shade member 30 is positioned rearward (to the right in FIG. 1), the rear end portion 30b of the shade member is located exactly at the discharge portion 15, and
The rear opening and the side opening 32 of the shade member 30 secure light traveling from the discharge portion 15 to the effective reflection surface 22 and the upper effective reflection surface 23A, but block light traveling to the lower effective reflection surface 23B. Then, a passing beam is formed by the light reflected on the first effective reflection surface 22 and the upper effective reflection surface 23A. That is, the low beam light distribution pattern Ac by the projection optical system and the low beam light distribution pattern Aa by the reflection optical system are combined to form a low beam.

The band-like region 30c at the rear end of the shade member 30 functions to block light traveling toward the steps 24 and 25 between the effective reflection surfaces 22 and 23. 5 to 7 show a second embodiment of the present invention. FIG. 5 is a longitudinal sectional view of an automobile headlamp, FIG. 6 is a front view of a reflector housed in a lamp body, and FIG. It is an exploded perspective view of a movable shade.

In the above-described first embodiment, since the shade member 30 has a structure capable of moving along the optical axis direction, when the traveling beam is formed by moving the shade member 30 forward (see the phantom line in FIG. 1). In addition, a problem arises in that a part of the reflected light from the first effective reflection surface 22 is blocked by the front end portion 30a of the shade member and the light flux utilization rate is reduced. However, in this embodiment, the shade member 30 includes a cylindrical fixing portion 33,
The shade movable portion 34 is configured by two shade movable portions 34 that can move in the direction of the optical axis L with a diameter slightly larger than the shade fixed portion, and is a part of the shade member 30.
Therefore, the amount of movement of the shade member is small, and the proportion of light that is reflected by the effective reflection surface and travels toward the lens step 11a is small. That is, when the shade movable portion 34 is located rearward (rightward in FIG. 5),
When the side opening 32 shown in the first embodiment is formed by the shade fixing portion 33 and the shade movable portion 34, and the shade movable portion 34 is positioned in front (left side in FIG. 5) (see FIG. Shade fixing part 33)
The shade movable portion 34 does not protrude to the rear of the shade fixing portion 33. Therefore, when the traveling beam is formed by moving the shade member 30 (shade movable portion 34) forward, the first effective reflection surface 22
There is an advantage that the ratio of the light reflected by the light beam is blocked by the shade member 30 is small, so that the light flux utilization rate does not greatly decrease.

The rest is the same as the first embodiment,
The description is omitted by attaching the same reference numerals. Reference numeral 31a is a leg for fixing the shade fixing portion 33 to the reflector 20. The light distribution pattern of the headlamp in the second embodiment is substantially the same as the light distribution pattern of the headlamp in the first embodiment (see FIG. 4).

8 to 11 show a third embodiment of the present invention. FIG. 8 is a longitudinal sectional view of an automobile headlamp, FIG. 9 is a front view of a reflector housed in a lamp body, FIG. 10 is an explanatory diagram for explaining the cross-sectional shape of the second effective reflection surface, and FIG. 11 is a diagram showing a light distribution pattern created by the headlamp. In this embodiment, defines into a first effective reflective surface 22, the upper reflection surface 22A and the lower reflecting surface 22B to border a central axis L ₁ position of the ramp of the elliptical shape near the bulb insertion hole 12 The two reflecting surfaces 22A and 22B correspond to FIG.
It is formed in two ellipsoidal shapes Ca and Cb having the 0 signs La and Lb as rotation center axes and having a common first focus. The reflecting surface 22A to the lamp center axis L ₁ position above the (lower)
(22B) are set so that the second focal points respectively come;
Shades 16A and 16B for forming clear cut lines are provided at positions near the second focal point on the reflecting surfaces 22A and 22B, respectively.
Is erected. Projection lenses 17A, 17B are arranged in front of the shades 16A, 16B, respectively.
It has a structure in which two projection optical systems are arranged side by side, and is formed by a light distribution pattern formed by these two projection optical systems and a reflection optical system composed of an effective reflection surface 23A and a lens step 11a. The light distribution patterns are combined to form a low beam. The shade 16
The upper edge of A is formed in a shape having a 15-degree cut line, the upper edge of the shade 16B is formed in a shape having a horizontal cut line, and the symbol Ad in FIG. 11 is formed by an upper projection optical system. The light distribution pattern, symbol Ac, is a light distribution pattern formed by the lower projection optical system.
The other parts are the same as those of the second embodiment, and the description thereof will be omitted by retaining the same reference numerals.

As described above, in the present embodiment, the projection type optical system is provided at the upper and lower positions of the shade member 30, and the optical path of the light reflected by the reflection surfaces 22A and 22B is formed on the outer periphery of the shade member 30. The reflection surface 22
A, the reflected light at 22B is not blocked by the shade member 30,
It can be said that the luminous flux utilization rate is high. Further, since two projection optical systems are provided, more desirable light distribution control can be performed by making the shapes of the shades 16A and 16B different from each other.

FIGS. 12 and 13 show a fourth embodiment of the present invention. FIG. 12 is a perspective view of a reflector which is a main part of an automobile headlamp, and FIG. 13 is a horizontal sectional view around the reflector. is there. In this embodiment, the shade fixing portion 33 is formed long forward, and
, And most of the light reflected on the first effective reflection surface 22 is directed to the projection lens 17, thereby further increasing the light flux utilization rate of the projection optical system. The clear cut line forming shade 16 is fixed to the shade fixing portion 33.

FIG. 13 shows a state in which the shade movable portion 34 is at the rear position, the light from the discharge portion 15 toward the reflection surface 23B is blocked, and a passing beam is formed. When the movable shade 34 moves to the front position indicated by the imaginary line in FIG. 13, light is also guided to the reflection surface 23B to form a traveling beam. Reference numeral 33a denotes a running groove of the leg 31 formed on the lower surface of the shade fixing portion 33. The other parts are the same as those of the second embodiment described above, and the description thereof will be omitted by retaining the same reference numerals.

FIGS. 14 and 15 are a vertical sectional view of a vehicle headlamp according to a fifth embodiment of the present invention and a diagram showing a light distribution pattern formed by the headlamp. In this embodiment, a structure in which a shade 16 for forming a clear cut line in a projection type optical system is fixedly integrated with a leg 31 of a shade movable portion 34 and moves in the optical axis direction in conjunction with slide of the shade movable portion 34. The feature is that it is.

That is, when forming the traveling beam in which the shade movable portion 34 moves forward, the shade 16 for forming the clear cut line moves to the projection lens 17 side, so that the optical axis L
The light blocking amount of the light traveling further downward increases, and the light distribution illuminating the road surface is reduced. On the other hand, the amount of light blocking upward from the optical axis L is reduced, and a new light distribution pattern indicated by the symbol Ae in FIG. 15 is formed and combined with the light distribution pattern by the reflection type optical system, so that it becomes a traveling beam. Desired light distribution is obtained. The other parts are the same as those in the second embodiment described above, and the description thereof will be omitted by retaining the same reference numerals.

In the above embodiment, a discharge bulb is used as a light source, but a filament bulb may be used.

[0027]

As is apparent from the above description, according to the vehicle headlamp according to the present invention, the reflected light in the region near the optical axis of the reflector, which is difficult to control light distribution in the lens step, is used to form a clear cut line shade. The projection type optical system has a structure in which the light is projected and distributed by the lens type, and the reflected light in the area away from the optical axis of the reflector, which is easy to control by the lens step, is reflected and distributed by the reflective type optical system with the movable shade. By driving the movable shade, a passing beam can be formed with the traveling beam, and there is no glare light and a large light emitting surface can be secured.
Light distribution excellent in both visibility from oncoming vehicles and visibility from pedestrians can be obtained.

According to the second aspect, the movable shade is composed of the shade movable portion and the shade fixed portion, and the shade movable portion moves during the formation of the traveling beam and overlaps with the shade fixed portion. The amount of light that is transmitted is small, and the light flux utilization rate that contributes to light distribution is increased.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an automotive headlamp according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a reflector housed in a lamp body.

FIG. 3 is a front view of the reflector.

FIG. 4 is a view showing a light distribution pattern formed by the headlamp.

FIG. 5 is a longitudinal sectional view of a vehicle headlamp according to a second embodiment of the present invention.

FIG. 6 is a front view of a main part of the reflector;

FIG. 7 is an exploded perspective view of a movable shade as a main part.

FIG. 8 is a longitudinal sectional view of a vehicle headlamp according to a third embodiment of the present invention.

FIG. 9 is a front view of a main part of the reflector;

FIG. 10 is an explanatory diagram illustrating a cross-sectional shape of a second effective reflection surface.

FIG. 11 is a view showing a light distribution pattern formed by the headlamp.

FIG. 12 is a perspective view of a reflector which is a main part of a fourth embodiment of the present invention.

FIG. 13 is a horizontal sectional view of the reflector.

FIG. 14 is a longitudinal sectional view of an automobile headlamp according to a fifth embodiment of the present invention.

FIG. 15 shows a light distribution pattern formed by the headlamp.

FIG. 16 is a perspective view of a main part of a conventional automotive headlamp.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Lamp body 11 Front lens 11a Light distribution control step 14 Discharge bulb which is a light source 16 Shade for forming a clear cut line 17 Projection lens 20 Reflector 22 (22A, 22B) Effective reflecting surface which is a first elliptical reflector 23 (23A, 23B) An effective reflection surface which is a parabolic second reflector 30 A shade member which is a movable shade 33 A shade fixing portion 34 A shade movable portion L Optical axis

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F21S 8/10 F21V 14/00

Claims (2)

(57) [Claims] A first reflector having a substantially ellipsoidal shape; a second reflector having a parabolic shape provided around the first reflector; and a position near a first focal point of the first reflector. A light source provided at a position near the focal point of the second reflector, and a light source provided at a position near the second focal point of the first reflector to form a clear cut line for blocking light upward from the optical axis. A shade, a projection lens disposed in front of the clear cut line forming shade, for projecting and distributing light reflected by the first reflector, and a projection lens provided at a position surrounding the light source; A movable shade that operates along the optical axis to block a portion of the light that is directed to the second reflector when passing beams are formed, but does not block the light that is directed to the second reflector. Automotive head lamp, characterized in that. 2. The shade according to claim 1, wherein the movable shade is a shade fixing portion that blocks light directed to an area other than the effective reflection surface of the second reflector, and a position protruding toward the reflector side of the shade fixing portion when a low beam is formed. 2. An automotive vehicle according to claim 1, wherein a part of the light directed to the effective reflection surface of the second reflector is blocked, and the shade fixed part and the shade movable part which is overlapped at the time of forming the traveling beam are formed. head lamp.