JPH09129003A - Head lamp for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the adverse effect on lighting fixture distributing performance due to light flux reflected from an annular face for a head lamp for a vehicle which has a stepped reflecting mirror with the annular face on the periphery of a bulb insertion hole. SOLUTION: An annular face consists of an annular curved face 14' which has a rotational paraboloid with a focal point near behind an auxiliary light filament 18 for a H4 bulb inserted in a bulb insertion hole 10a. A plurality of horizontal scattering steps 14's are formed at the upper half of the annular curved face 14'. Light flux reflected from the upper half of the annular curved face 14' is reversed by the annular curved face 14' when auxiliary light is on, to form downward light. If the horizontal scattering steps 14's are not formed, bright light stagnation occurs in part in an auxiliary light distribution pattern to form irregular light. With the scattering effect of the horizontal scattering steps 14'a, light flux reflected from the annular curved face 14' is scattered and distributed in horizontal and no irregular light is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle headlamp having a reflecting mirror having a reflecting surface formed by arranging a plurality of light distribution steps.

[0002]

2. Description of the Related Art Conventionally, many vehicular headlamps have been so constructed that a parallel luminous flux obtained by being reflected by a reflecting surface composed of a paraboloid of revolution is controlled by a lens step. ing.

However, there are many headlamps in which the lens inclination angle is set to a large value due to vehicle design requirements, and in such a headlamp, there is a limit to the light distribution control by only the lens step, and the headlight is also limited. There is also a demand for the design of the lamp itself to produce the transparent feeling of the lens and improve its appearance.

Therefore, in recent years, a headlamp has been developed in which a part or all of the light distribution control function performed by the lens is loaded on the reflecting mirror. That is, a reflector in such a headlight is disclosed in, for example, Japanese Patent Laid-Open No. 4-25310.
As disclosed in Japanese Patent Laid-Open No. 1-58, it has a reflecting surface in which a plurality of light distribution steps are arranged, and a lens step is formed by appropriately setting the curved surface shape of each light distribution step. It is possible to obtain a desired light distribution performance without needing to do so or by forming a lens step having a shallow carved part. Hereinafter, the reflecting mirror having such a reflecting surface is abbreviated as “reflecting mirror with step”.

[0005]

By the way, a valve insertion hole is generally formed at the rear apex of the reflecting mirror, but the periphery of the valve insertion hole is formed into a flat surface due to restrictions on the valve mounting structure and the like. A formed annular surface may be provided. For example, when a paraboloid of revolution with a relatively long focal length is adopted as the reflecting surface, it is necessary to set the filament position to a position far forward from the apex of the paraboloid of revolution, which is inevitable. The annular surface portion is provided in the. Similarly, also in the above stepped reflector, an annular surface portion may be formed due to restrictions on the valve mounting structure and the like.

However, in the case where the above-mentioned annular surface portion is formed in the stepped reflecting mirror, there are the following problems.

That is, the light incident on the annular surface portion from the bulb is specularly reflected by the annular surface portion to be emitted as a ring-shaped light beam, which is radiated forward. As described above, since the lens is transparent or only a partially carved lens step is formed, as shown in FIG. 8, the ring-shaped reflected light beam is diffused as it is or slightly left and right. The lamp is illuminated in front.

Therefore, the passing beam has a problem that glare is given to an oncoming vehicle or a pedestrian by the light beam emitted upward from the annular surface portion.

Further, in the traveling beam, there is a problem that it becomes difficult to travel because the road surface immediately in front of the vehicle is partially brightened by the light flux emitted downward from the annular surface portion. This problem also occurs in the low beam in the case of headlights which have a shadeless bulb below the low beam filament.

The present invention has been made in view of the above circumstances, and in a vehicle headlamp provided with a stepped reflecting mirror having an annular surface portion provided on the peripheral edge of the bulb insertion hole, the annular surface portion is provided. It is an object of the present invention to provide a vehicle headlamp that can minimize the adverse effect of the reflected light flux on the light distribution performance of the lamp.

[0011]

The present invention is intended to achieve the above object by forming a plurality of horizontal diffusion steps in a predetermined range of the annular surface portion.

That is, according to the present invention, as described in claim 1, there is provided a reflecting mirror having a reflecting surface in which a plurality of light distribution steps are arranged, and the reflecting mirror is formed on the rear top portion of the reflecting mirror. In a vehicle headlamp in which an annular surface portion is provided on the peripheral edge of a bulb insertion hole, a plurality of horizontal diffusion steps are formed in a predetermined range of the annular surface portion.

The above "light distribution step" means a step formed for the purpose of controlling the light distribution of the headlight, and its specific shape is not particularly limited.

The above "predetermined range" may be the entire area of the annular surface portion or a part thereof, and is set according to the influence of the luminous flux reflected from the annular surface portion on the light distribution performance in the lamp. do it.

[0015]

As described above, according to the present invention, in the present invention, a plurality of horizontal diffusion steps are formed in a predetermined area of the annular surface portion provided on the periphery of the bulb insertion hole of the stepped mirror. The reflected light flux emitted from this area becomes diffused light that spreads in the horizontal direction. Therefore, the intensity of the reflected light flux can be significantly reduced as compared with the case where the step for horizontal diffusion is not formed, whereby the adverse effect of the reflected light flux on the light distribution performance of the lamp is minimized. be able to.

In this case, the reflected light flux radiated upward from the annular surface portion causes glare and has a great adverse effect on the light distribution performance of the lamp. Therefore, as described in claim 3, at least the predetermined range is set. It is preferable to set it so as to include the region above the valve insertion hole.

In the above structure, as described in claim 2, the annular surface portion is constituted by a paraboloid of revolution having a focal position near the filament of the valve inserted into the valve insertion hole. , In the state where the step for horizontal diffusion is not formed, the reflected light beam from the annular surface portion can be already directed toward the front of the lamp and can be irradiated in a form close to a parallel light beam. It is possible to prevent the upward scattered light that causes the above. However, in reality, even in the case of such a configuration, unexpected stray light (for example, reflected light from the stem supporting the filament) is incident on the annular surface portion, and scattered light in directions other than the above is generated. Therefore, it is possible to effectively reduce glare or light unevenness not only by forming the annular surface portion with a paraboloid of revolution but also by forming the horizontal diffusion step to diffuse the scattered light component.

By the way, a plurality of light distribution steps are arranged on the reflecting surface of the stepped reflecting mirror. As described in claim 4, the pitch between the horizontal diffusion steps is By setting the pitch according to the horizontal pitch between the respective light distribution steps, it is possible to provide design continuity between the annular surface portion and the reflection surface, thereby improving the appearance quality of the lamp. be able to.

In this case, as described in claim 5, the pitch between the horizontal diffusion steps is set to a pitch which is an integer fraction of the horizontal pitch between the light distribution steps. For example, at least one of the boundary lines between the horizontal diffusion steps and the boundary line between the light distribution steps is vertically connected, so that the design between the annular surface portion and the reflection surface is designed. The continuity above can be increased.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing a vehicle headlamp according to a first embodiment of the present invention.

As shown in the figure, the reflector 10 of this vehicle headlamp is a stepped reflector having a reflecting surface 12 in which a plurality of light distribution steps 12a are arranged on a predetermined reference paraboloid of revolution. The mirror is configured to generate a required light distribution pattern as a headlight without requiring light distribution control by a lens step. Therefore, a transparent lens is arranged in front of the stepped reflecting mirror 10.

A valve insertion hole 10a is formed at the rear top of the reflecting mirror 10. A valve mounting portion (not shown) for disposing the bulb 16 at a predetermined position in the optical axis Ax direction of the reflecting mirror 10 with respect to the reflecting surface 12 is provided on the rear surface side of the reflecting mirror around the bulb insertion hole 10a. ing. For this reason, on the front side of the reflecting mirror around the bulb insertion hole 10a,
An annular flat surface portion 14 is provided. The bulb 16 is a so-called H4 bulb, and the filament 1 for the auxiliary lamp is used.
Reference numeral 8 has a filament axis extending in the optical axis Ax direction of the reflecting mirror 10. In the vicinity of the lower portion of the auxiliary lamp filament 18, light irradiation from the auxiliary lamp filament 18 to the lower portion of the bulb 16 is blocked. A shade 20 is provided.

The plurality of light distribution steps 12a constituting the reflection surface 12 are sectioned into a vertically long rectangular shape or a slanting trapezoidal shape, and each of the light distribution steps 12a is the reference rotation parabola. It is formed of a hyperbolic paraboloid set at each position on the surface. Here, the "hyperbolic paraboloid" is, as shown in FIG. 2, composed of a parabola whose vertical cross section (or a cross section inclined by a predetermined angle from the vertical direction) spreads toward the front of the lamp, and a horizontal cross section (or horizontal cross section). (A cross section inclined by a predetermined angle from the direction) means a hyperbolic parabolic surface formed of a parabola extending toward the rear of the lamp, or a curved surface similar to this.

The light distribution steps 12a are formed at a predetermined pitch, but the light distribution steps 12a located above the bulb insertion holes 10a have a relatively wide pitch in the horizontal direction and are set to 20 mm. Has been done.

The lower half portion of the annular flat portion 14 remains flat, but a plurality of horizontal diffusion steps 14a are formed in the upper half portion. By these horizontal diffusion steps 14a, the light incident on the upper half portion from the auxiliary lamp filament 18 is diffusely reflected to the left and right as shown by the solid line in the figure, without being specularly reflected in the direction shown by the dashed line in the figure. ing. Since the shade 20 blocks the downward light irradiation from the auxiliary light filament 18, the light from the auxiliary light filament 18 does not enter the lower half of the annular flat surface portion 14.

Each of the horizontal diffusion steps 14a is a convex lens-like step divided into vertical stripes, and its horizontal pitch is set to 5 mm. As a result, every three boundary lines between the horizontal diffusion steps 14a are vertically connected to the light distribution step 12a above the bulb insertion hole 10a.

As described in detail above, in this embodiment, a plurality of horizontal diffusion steps 14a are formed in the upper half of the annular flat surface portion 14 provided on the periphery of the bulb insertion hole 10a of the reflecting mirror 10. Therefore, the following effects can be obtained.

That is, the reflected light flux from the upper half portion of the annular flat surface portion 14 constitutes upward scattered light which causes glare when the sub lamp is lit. As shown in FIG. 1, the horizontal diffusion step 14a is performed. By the diffusing action of the above, the reflected light flux becomes diffused light that spreads in the horizontal direction, so that the intensity thereof can be greatly reduced compared to the case where the horizontal diffusing step 14a is not formed. It is possible to minimize the adverse effect of the light flux on the light distribution performance of the lamp.

In this case, it is possible to diffuse the upward scattered light by subjecting the upper half portion of the annular flat surface portion 14 to the embossing process. By forming the horizontal diffusion step 14a as described above, it is possible to achieve a design harmony with the light distribution step 12a that constitutes the reflection surface 12.

Moreover, in the present embodiment, the pitch of the plurality of horizontal diffusion steps 14a is set to 1 of the pitch of the light distribution steps 12a formed on the reflecting surface 12 above the horizontal diffusion steps 14a.
/ 4 is set so that every three boundary lines between the horizontal diffusion steps 14a are vertically connected to the light distribution step 12a above the bulb insertion hole 10a, so that the annular flat surface portion 14 and the reflection surface are reflected. The design continuity with the surface 12 can be improved.

In the present embodiment, a plurality of horizontal diffusion steps 14a are formed in the upper half of the annular flat surface portion 14 in order to reduce the intensity of the upward scattered light when the sub lamp is turned on. The horizontal diffusion step 14a may be formed over the entire area of the annular flat surface portion 14. By doing so, the following effects can be obtained. That is, there is no shade such as the shade 20 in the main light filament of the H4 bulb, so that the light from the main light filament also enters the lower half portion of the annular flat surface portion 14. When this incident light is specularly reflected by the lower half portion and is irradiated downward, the road surface immediately in front of the vehicle becomes partially bright and it becomes difficult to travel, but as described above, the lower half portion of the annular flat surface portion 14 is used. If the step 14a for horizontal diffusion is formed also in the portion, it is possible to reduce the partial brightening of the road surface immediately before the vehicle, and thereby to reduce the difficulty in traveling.

Next, a second embodiment of the present invention will be described.

FIG. 3 is a front view showing a vehicle headlamp according to this embodiment.

As shown in the figure, the reflecting mirror 10 of the vehicle headlamp adopts an annular curved surface portion 14 'in place of the annular flat surface portion 14 in the first embodiment. The annular curved surface portion 14 'is composed of a paraboloid of revolution, and its focal point is at the same position as the focal point F of the reference paraboloid of revolution of the reflecting surface 12 (that is, the valve insertion portion) as shown in FIG. It is set at a position near the rear of the filament of the valve inserted in the hole 10a). Then, this annular curved surface portion 14 '
The focal length of the paraboloid of revolution that forms the is set to a value slightly smaller than the focal length of the reference paraboloid of revolution of the reflecting surface 12. As a result, as shown in FIG.
At the boundary line between 4'and the reflecting surface 12, the auxiliary lamp filament 18
A step portion is formed so that the light from does not enter. Similar to the annular flat surface portion 14, the horizontal diffusion step 14'a is formed in the upper half portion of the annular curved surface portion 14 '.

The light beam reflected from the upper half of the annular curved surface portion 14 'is, as shown in FIG.
However, if the horizontal diffusion step 14'a is not formed, as shown by the broken line in the figure, a partially bright light pool is formed in the auxiliary lamp light distribution pattern. As a result, light unevenness is formed. However, due to the diffusing action of the horizontal diffusing step 14'a, the light flux reflected from the annular curved surface portion 14 'can be diffused and distributed in the horizontal direction to eliminate the light unevenness. When unexpected stray light such as reflected light from the auxiliary lamp filament 18 or a stem supporting the main lamp filament is incident on the upper half of the annular curved surface portion 14 ', upward scattered light is generated. Such a scattered light component can be diffused by the operation step 14'a.

As described above, according to the present embodiment, it is possible to effectively reduce glare or light unevenness, thereby minimizing the adverse effect on the light distribution performance of the lamp due to the luminous flux reflected from the annular curved surface portion 14 '. Can be suppressed to

In this embodiment, a plurality of horizontal diffusion steps 14 'are formed on the upper half of the annular curved surface 14'.
The circular curved surface portion 14 'is formed so as to form a.
The horizontal diffusion step 14a may be formed over the entire area.

Next, a modification of the second embodiment will be described.

FIG. 6 is a front view showing a vehicle headlamp according to this modification.

As shown in the figure, in the reflecting mirror 10 'of this vehicle headlight, a plurality of horizontal diffusing steps 14'a are formed in the upper half of the annular curved surface portion 14', which is the second aspect. However, the upper wall of the reflecting mirror is curved. A plurality of left and right diffusion steps 22a are formed in the center of the inner surface 22 of the upper wall of the reflecting mirror 10 ', and a plurality of score lines 24a are formed on the inner surface 24 of the lower wall.
Are formed.

The reflecting mirror 10 'has an inner surface 22 on its upper wall.
Assuming that the right and left diffusing step 22a is not formed due to the curving, the light from the bulb 16 that is incident on the central portion of the inner surface 22 of the upper wall portion is all seen in the front view of the lamp as shown by the broken line in the drawing. The light beam is reflected in a substantially downward direction, is further reflected by the inner surface 24 of the lower wall portion, and becomes a light beam that is close to a parallel light beam heading directly above, which causes strong glare. Therefore, the right and left diffusing step 22a is formed in the central portion of the inner surface 22 of the upper wall portion to diffuse the incident light to the central portion of the inner surface 22 of the upper wall portion to the left and right as shown by the solid line in the figure. It is designed to be reduced. Each of the left and right diffusion steps 22a is a convex step extending in the optical axis direction of the reflecting mirror 10 ', and has a flat rear end portion and a front end portion that rises in an arc shape. Each of the left and right diffusion steps 22a is formed with a pitch of 5 mm, whereby the light distribution step 12 above the bulb insertion hole 10a.
The design continuity with a is improved.
The left / right diffusion step 22a formed in the central portion of the inner surface 22 of the upper wall portion is particularly effective in a reflecting mirror in which the inner surface 22 of the upper wall portion is curved like the reflecting mirror 10 '. Even when 22 is flat, the left and right diffusion steps 22a can be formed to reduce the glare accordingly.

On the other hand, the plurality of score lines 24a formed on the inner surface 24 of the lower wall portion have the same pitch as the pitch of each light distribution step 12a located at the lowermost end of the reflecting surface 12, and each light distribution step 12a. It is formed so as to be connected to the boundary line between each other. Thereby, as shown in FIG.
It is possible to enhance the design continuity between the inner surface 24 and the inner surface 24 of the lower wall portion. Note that, instead of forming the score lines 24a on the inner surface 24 of the lower wall portion, it is possible to form the steps for left and right diffusion at the above pitch. By doing so, not only the effect of design but also the effect of reducing glare can be obtained. You can also get

In each of the above embodiments, the reflecting surface 1 is used.
Although it has been described that each of the light distribution steps 12a constituting 2 is formed of a hyperbolic paraboloid, the present invention is not limited to this, for example, an elliptic paraboloid or a rotation paraboloid. It is also possible to adopt other curved surfaces such as. Here, the "elliptical paraboloid" means a parabola in which a vertical cross section (or a cross section inclined by a predetermined angle from the vertical direction) and a horizontal cross section (or a cross section inclined by a predetermined angle from the horizontal direction) spread toward the front of the lamp. It means an elliptical paraboloid composed of, or a curved surface similar to this.

[Brief description of the drawings]

FIG. 1 is a front view showing a vehicle headlamp according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a curved surface shape of each light distribution step constituting the reflecting surface of the reflecting mirror of the first embodiment.

FIG. 3 is a front view showing a vehicle headlamp according to a second embodiment of the present invention.

FIG. 4 is a partial sectional view of the reflecting mirror of the second embodiment.

FIG. 5 is an explanatory diagram showing an operation of the second embodiment.

FIG. 6 is a front view showing a vehicle headlamp according to a modified example of the second embodiment.

FIG. 7 is a partial perspective view of the modified example.

FIG. 8 is a perspective view illustrating a conventional example.

[Explanation of symbols]

 10, 10 'Reflective mirror with step (reflector) 10a Valve insertion hole 12 Reflective surface 12a Light distribution step 14 Annular flat surface part (annular surface part) 14' Annular curved surface part (annular surface part) 14a, 14'a Horizontal diffusion step 16 Bulb 18 Sub Light Filament 20 Shade 22 Upper Wall Inner Surface 22a Left / Right Diffusion Step 24 Lower Wall Inner Surface 24a Ruled Line Ax Reflector Optical Axis

Claims (5)

[Claims] 1. A reflecting mirror having a reflecting surface formed by arranging a plurality of light distribution steps, wherein an annular surface portion is provided at a peripheral edge of a bulb insertion hole formed at a rear top portion of the reflecting mirror. A vehicle headlamp, wherein a plurality of horizontal diffusion steps are formed in a predetermined area of the annular surface portion. 2. The vehicle headlamp according to claim 1, wherein the annular surface portion is a paraboloid of revolution having a focal position in the vicinity of a filament of the bulb inserted into the bulb insertion hole. 3. The vehicle headlamp according to claim 1 or 2, wherein the predetermined range includes at least a portion above the bulb insertion hole. 4. The pitch between the horizontal diffusion steps is set to a pitch corresponding to the horizontal pitch between the light distribution steps. Headlights for vehicles listed above. 5. The pitch between the horizontal diffusion steps is set to a pitch which is an integer fraction of the horizontal pitch between the light distribution steps. The vehicle headlights listed.