JPH0515681Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inclined headlamp in which a front lens provided in front of a reflector is inclined with respect to the optical axis.

[Conventional technology]

Conventionally, as a vehicle lamp, a headlamp has been used, as shown in FIG. 52, as shown in the front view of the lens in FIG. 5b and the irradiation light distribution pattern in FIG.
3. Refraction prism areas 54, 54 for converging the light beam near the optical axis (light distribution pattern b) and a refraction prism area for deflecting the light beam in the direction of the 15 degree cut line (arrow CL) (light distribution pattern c) 55 is formed into sections, and the other areas have an angular step structure consisting of a light distribution adjustment (unevenness elimination) area 56 and a running beam area 57. Further, this type of headlamp has a structure in which the front lens 52 is inclined θ with respect to the optical axis L in order to provide an appearance that follows the body line of a vehicle such as an automobile.

[The problem that the idea attempts to solve]

Therefore, in the above-mentioned conventional inclined headlight, as shown in light distribution pattern b (see Figure 6 c), the larger the inclination angle θ of the front lens, the more the cylindrical light is diffused to the left and right. Since the light distribution pattern a of the diffused light flux of the lens area 53 curves downward at the light projection destination, there is a problem in that the visibility at a distance deteriorates.

Furthermore, this type of structure of the lens steps constituting the cylindrical lens region 53 has the problem that it is impossible to obtain uniform light distribution because sag occurs between the lens steps during molding.

The present invention was devised in view of the above-mentioned problems, and its purpose is to provide an inclined headlamp in which the distributed luminous flux is not curved on both sides and the light distribution is uniform. be.

[Means to solve the problem]

In order to achieve the above object, an inclined headlamp according to the present invention is a headlamp in which a light source is provided near the focal point of a reflector having a parabolic mirror surface, and a front lens is covered with an aperture surface of the reflector. , the light flux from the light source is made parallel in the vertical cross section and in the horizontal cross section with respect to the diffusion area, which has a cylindrical lens that diffuses the light beam to the left and right in a part of the front lens on the upper and lower sides of the central part of the reflector. A reflector unit that condenses and diffuses light is configured to intersect with the optical axis, and a beam of condensed and diffused light from the reflector is directed to the light flux incident area of the front lens corresponding to the reflector provided with the diffuse reflector unit. The convex lens for controlling the direction is configured in the shape of a straight Fresnel lens, and the cylindrical lens step is configured in a "V" shape with respect to the elevation angle tilting or depression angle tilting of the front lens.
The gist of this is that it is constructed in a letter-like or ``V''-like shape.

[Effect]

According to the above configuration, the elliptical reflector reflects the light beam from the light source that is incident on the light beam diffusion region of the front lens so that the light beam is parallel to the optical axis in the vertical cross section and intersects in the horizontal cross section. By configuring this section, the light distribution characteristics are improved.

In addition, by configuring the cylindrical lens of the front lens in a "V" shape or "V" shape, even if the front lens is tilted up or down, the distributed light beam will not be curved on both sides, resulting in good distribution. Able to maintain light.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an inclined headlamp according to the present invention will be described with reference to the drawings.

FIG. 1 is a front view of the inclined headlamp, and FIG. 2 is a longitudinal sectional view thereof.

In the drawings, 1 is a reflector, and on the optical axis L of the reflector 1 is provided a light source 2 such as an H4 bulb that does not use straight light for automobiles and whose tip part is coated with a light-shielding film or constitutes a light-shielding cover. , the front surface of the reflector 1 is covered with a front lens tilted (tilt angle θ) not perpendicular to the optical axis L.

Here, the structure of the reflector 1 will be explained. Figure 3a is horizontal (arrow view A-) including the optical axis L.
A) Cross-sectional view, FIG. 3b is a vertical (arrow view B-B) cross-sectional view including the optical axis L, and F is the focal point.

The reflector 1 of the present invention is required to collect and diffuse the light rays from the light source 2 so that they are parallel in the vertical direction and intersect with the optical axis in the horizontal direction.

In a vertical section including the optical axis L, the reflector equation R(X, Y, Z) is: A reflective mirror surface 11 with focal length F ₀ where R(X, Y, O) = 4f ₀ X-Y ² = 0 It is. Within this cross section, the light beam L1 from the light source 2 becomes parallel.

Next, in the horizontal plane that includes the optical axis L, the reflector curve R (X, O, Z) is (X-a) ² /a ² +Z ² /2f ₀ a-f ₀ ² = 1 (ellipse). The light source 2 is located near the distance f ₀ from the vertex O of the elliptical mirror surface 12 (first focal point in the case of an ellipse).

A light flux F→P that enters a point P on such a curve from a focal point F becomes a light flux P→Q (light collection/diffusion angle δ in the horizontal direction) that intersects the optical axis L. This light flux is made approximately parallel within the vertical section (vertical section including P→Q)
The mirror surface of the PQ vertical cross section has an optical axis of δ centered on the focal point F.
It is sufficient to consider an inclined paraboloid (focal length F2) and configure it to have the same cross-sectional shape at FQsinδ from this new optical axis L1.

That is, the desired shape of the reflector 1 is a parabolic mirror with a focal length Fδ even in the PQ vertical section.

In general, when the shape of the reflecting mirror of the reflector 1 is elliptical in the horizontal cross section, especially when the reflected light beam crosses the optical axis L, the focal length of the enveloping paraboloid in the PQ vertical cross section is fδ teeth,
It is larger than the focal length f ₀ in a vertical section including the optical axis L (f δ > f ₀ ).

When the reflector 1 of the above optical system is used, the light distribution on the screen of the passing filament of the H4 bulb used as the lighting light source 2 will be diffused with approximately the upper half cut off by the shade, as shown in Figure 4a. It becomes light distribution.

On the other hand, since the light flux of the traveling beam filament has no shade, the light distribution on the screen of the light flux reflected from the front surface of the reflector 1 is as shown in Fig. 4b, as the light flux also exists above the horizontal line H. , since the filament position is on the apex side of the reflector 1, the light distribution is narrower than that of the passing filament, resulting in a diffused light distribution that is optimal for a traveling beam.

Next, an example of a light distribution configuration of an inclined headlamp according to the present invention using the reflector 1 will be explained using a passing beam.

In the front view of the front lens 3 shown in FIG.
Diffusion lens step area 3 of this invention above and below the center
1 and 32 are arranged.

In the vertical section including the optical axis L shown in FIG. A light source 2 is placed near F.

Looking at the horizontal sectional view including the optical axis L in Figure 3b,
The horizontal cross-sectional shape of the reflector 1 in a range that includes at least the diffuser lens step areas 31 and 32 constitutes an ellipsoidal mirror portion 12, and the light source 2 is located near the first focal point F1 of the ellipse within this cross-section. Configure it as follows.

This embodiment is an example in which an H4 bulb is used as the lighting light source 2, and the first focal point F1 of the ellipsoidal mirror portion 12 is placed at an intermediate position between the main and sub-filaments.

The front lens 3 of the diffusion lens step areas 31 and 32 constitutes a lens step in which a cylindrical lens with a convex horizontal cross section is shaped like a Fresnel lens.

By the Fresnel lens step, the reflected light beam, which is made substantially parallel in the vertical section by the reflector 1 and condensed at the second focal point F2 of the ellipsoidal mirror section 12 in the horizontal section, is focused toward the front (on the front lens 3 side). I'm trying to make it shine. Therefore, the convex cylindrical Fresnel lens step increases the diffusion angle of the light beam diffused in the left-right direction by the reflector 1.

In this example, light distribution on the screen by the sub-filament (for passing beam) reflected from the reflector 1 (reflector reflected light only)
is as shown in FIG. 5a. That is, the light beam incident on area a of the reflector 1 is diffused left and right,
Regions b and c form a spot-like light distribution. Therefore, by using the reflector 1 of the present invention, it is possible to configure a basic light distribution for passing each other.

In addition, the reflected light from the main filament (for the traveling beam) is as shown in Figure 5b, and the reflected light from area a of reflector 1 is reflected on the upper side of the screen and
The reflected light in the a′ region is formed on the lower side. The reflected light in regions a and a' is diffused left and right, but it is slightly narrower than in the case of the sub-filament. The reflected light from other parts of the reflector 1 forms a spot near the optical axis. Therefore, the basic light distribution required for the traveling beam can be formed by the reflected light from the reflector 1 of the present invention, using the left and right diffused light in the a and a' regions and the reflected light in other parts.

The light distribution by these reflectors 1 can be adjusted to the desired light distribution required for the traveling beam (see Fig. 5 d) and the passing beam (see Fig. 5 c) by a refraction prism provided on the front lens 3. can.

In particular, the reflected light in the a region and a' region is transmitted to the front lens 3.
The convex Fresnel steps 31 and 32 diffuse the light over a wider angle without uneven distribution or loss, making it possible to provide a lamp with excellent lateral visibility.

In the case of the traveling beam, the diffusion range of the light reflected by the a and a' regions can also be adjusted by Fresnel steps of the corresponding front lens 3.

The case where the front lens is not tilted has been described above. Generally, when the upper end of the front lens tilts backward, light rays incident on the refracting prism parallel to the optical axis are refracted downward. It is known that this angle of depression increases as the prism angle increases and as the inclination angle θ increases.

Therefore, the apex angle of the prism becomes larger as the distance from the center of the Fresnel lens increases, so that the light flux incident on the refractive prism of the Fresnel lens (convex lens) in the a and a' regions becomes larger, so that the light distribution is diffused below the horizontal level. (see Figure 5e), reducing lateral visibility.

Therefore, in order to eliminate this phenomenon,
The Fresnel step in area a' must be carved in a "V" shape, as shown in FIG. In the above embodiment, the case where the upper end of the front lens 3 is retracted rearward is explained, but on the contrary, when the lower end of the front lens 3 is structured,
This problem can be solved by making the steps of the Fresnel lens into a "V" shape.

[Effect of idea]

Since the tilted headlight according to the present invention is constructed as described above, in a lamp using a parabolic reflector, the light flux from the light source that enters the light flux diffusion area of the front lens is directed relative to the optical axis. Become parallel in vertical section,
In addition, by configuring the ellipsoidal reflector section that reflects the light in a horizontal cross-sectional manner, the light distribution characteristics are improved, and a headlamp useful as a vehicle lamp can be constructed. The practical effects that follow are extremely large.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of an inclined headlamp according to the present invention, Fig. 2a is a longitudinal sectional view of the same, and Fig. 2b is
is a cross-sectional view of the same, FIG. 3a is a horizontal cross-sectional view (arrow view A-A) including the optical axis L, and FIG. 3b is a vertical cross-sectional view (arrow view B-A) including the optical axis L.
B) Cross-sectional views, Figures 4a and b and Figures 5a to 5e are explanatory diagrams showing the light distribution pattern on the screen,
The figure shows a conventional headlamp, in which a is a longitudinal sectional view, b is a front view of the lens, and c is a light distribution pattern of irradiated light. 1...Reflector, 2...Light source, 3...Front lens.

Claims (1)

[Claims for Utility Model Registration] A headlamp in which a light source is provided near the focal point of a reflector having a parabolic mirror surface, and a front lens is covered on the aperture surface of the reflector, wherein: A part of the front lens has a cylindrical lens that diffuses the light beam to the left and right.The light beam from the light source is focused and diffused so that it is parallel to the vertical cross section and intersects the optical axis in the horizontal cross section. a convex lens in the shape of a linear Fresnel lens for controlling the direction of the condensed and diffused light from the reflector, in a light flux incident area of the front lens corresponding to the reflector provided with the diffuse reflector part; An inclined headlamp characterized in that the cylindrical lens step is configured in a "V" shape or a "V" shape with respect to the elevation angle tilting or depression angle tilting of the front lens.