JPH0246601A - Headlight for automobile - Google Patents

Abstract

PURPOSE:To improve the visual recognition not only in a far distance but also at the feet, and to make it possible to use the running beams for passing beams in a high speed running concurrently, by making the focus distance of an upper side reflection surface longer than that of a lower side reflection surface, and arranging a light source for the running beams near the focus of the lower side reflection surface in almost parallel to the optic axis of the reflection surface. CONSTITUTION:The focus distance of an upper side reflection surface 3 is made longer than that of a lower side reflection surface 4, and the focus f1 of the upper side reflection surface and the focus f2 of the lower side reflection surface are almost at the same point in a plain observation. On the other hand, a light source 10 is arranged in almost parallel to the optical axis of the reflection surface, and at the front side of the focus f1 of the upper side reflection surface 3. And the light reflected by the upper side reflection surface 3, among the light of the running beams light source, is radiated to the far distance, contributing to the far distance visual recognition, while the light reflected by the lower side reflection surface 4 has a relatively large expansion, thereby improving the recognition even at the feet. Consequently, the running beams can be used for a passing beams in a high speed running concurrently, consequently.

Description

[Detailed description of the invention] The automobile headlamp of the present invention will be explained according to the following items.

A. Industrial field of application B0 Summary of the invention C0 Prior art [Fig. 6] D8 Problem to be solved by the invention [Fig. 6] E1 Means for solving the problem F. Examples [Figs. Figure 5] 80 Reflector, Light Source C, Lens G0 Effects of the Invention (A, Industrial Application Field) The present invention relates to a novel automobile headlamp. Specifically, regarding an automobile headlamp equipped with two light sources for a driving beam and a passing beam, when irradiating the driving beam, it is possible to illuminate a distant area well, and also to illuminate nearby road surfaces well, The object of the present invention is to provide a novel headlamp for automobiles that allows a running beam to be used like a passing beam when driving at high speed over a vast area.

(B. Summary of the Invention) The automobile headlamp of the present invention has two reflecting surfaces, an upper side and a lower side, each of which has a shape of a paraboloid of revolution cut in half below the road, The optical axes of these reflective surfaces are shifted up and down, the focal length of the upper reflective surface is made larger than that of the lower reflective surface, and the focus of the upper reflective surface and the focus of the lower reflective surface are approximately the same when viewed from above. position, and furthermore,
The traveling beam light source is arranged near the focal point of the lower reflective surface and approximately parallel to the optical axis of the reflective surface, so that the light reflected by the upper reflective surface of the light from the traveling beam light source is irradiated to a far distance, The light reflected by the lower reflective surface illuminates relatively near you, and when driving at high speed over a vast area, by using the running beam, you can see your feet from a distance as well as see your feet. This also makes it possible to use the running beam as a passing beam when driving at high speeds.

(C, Prior Art) [Figure 6] A conventional automobile headlamp with a single paraboloid of revolution reflector and two
Some have one light source and a lens.

FIG. 6 shows m pieces a of such automobile headlights.

b is a reflecting mirror, which has a reflecting surface C in the shape of a paraboloid of revolution, and XX is its axis of rotation, which is referred to as the optical axis.

Further, F is the focal point of the reflecting surface C.

d is a traveling beam filament, which has a coil shape and is disposed approximately at the focal point F of the reflecting surface C, approximately parallel to the optical axis XX. Reference character e designates a coiled filament for passing beams, which is disposed in front of the focal point F approximately along the optical axis x-x.

f is a light shielding cap, which is arranged so as to shield substantially the lower half of the passing beam filament e from the reflecting surface C; Although not shown, this light shielding cap f
In addition, a light shielding means is provided, and the filament d%
This is to prevent the direct light e from being emitted forward.

Reference numeral g denotes a lens placed in front of the reflecting mirror, on which necessary lens elements (not shown) are formed.

However, in the case of the automobile headlamp a, the light from the traveling beam filament d is reflected by the reflective surface C, and the optical axis
-X becomes a luminous flux approximately parallel to X, and the light from the filament e for passing beams is reflected by the road half of the reflecting surface C and becomes a luminous flux slightly downward with respect to the optical axis x-x. The light is controlled by a predetermined light distribution pattern.

(D. Problem to be Solved by the Invention) [Figure 6] By the way, in the above-mentioned conventional automobile headlight a, when irradiating the driving beam, the front side, for example, the part from 20 m forward to the front side, is sufficiently illuminated. The problem is that it cannot be irradiated.

For example, when driving in a vast area such as Australia, a driving beam is often used, and therefore the driving beam is also required to have the characteristics of a passing beam. That is, it is required to be able to sufficiently irradiate distant areas while also irradiating near areas.

In the case of a paraboloid of revolution reflecting surface, if the focal length of the paraboloid is increased, the reflected light from the filament placed at the focal position will be concentrated in a small range around the optical axis More light reaches far away, improving long-distance visibility, but on the other hand, less light is directed toward the front, deteriorating front visibility.

Conversely, if the focal length of the paraboloid is made smaller, the reflected light from the filament placed at that focal point will be closer to the optical axis
Since the amount of deviation in parallelism with respect to the object increases, the divergence angle of the luminous flux of the reflected light becomes larger than when the focal length is large, making it possible to sufficiently spread the light to the front. However, the fact that the divergence angle of the reflected light with respect to the optical axis , there is a problem in that long-distance visibility deteriorates and the beam cannot function adequately as a traveling beam.

(E. Means for Solving the Problems) Therefore, in order to solve the above problems, the automobile headlamp of the present invention has two reflective surfaces, an upper side and a lower side, and each of the two reflective surfaces rotates. It has the shape of a paraboloid cut in half below the road, and by shifting the optical axis of these reflective surfaces up and down,
The focal length of the upper reflective surface is made larger than that of the lower reflective surface, and the focal length of the upper reflective surface and the focal point of the lower reflective surface are approximately at the same position when viewed from above, and the light source for the traveling beam is is arranged near the focal point of the lower reflective surface and approximately parallel to the optical axis of the reflective surface.

Therefore, in the automobile headlamp of the present invention, of the light from the light source for the running beam, the light reflected by the upper reflective surface is irradiated far away, contributing to long-distance visibility, and is reflected by the lower reflective surface. Since the emitted light has a relatively large spread along the optical axis, it illuminates even relatively near areas, and when driving at high speed over a vast area, by using a traveling beam, it is possible to improve not only long-distance visibility but also so-called foot visibility. This also makes it possible to use the traveling beam as a passing beam when driving at high speeds.

(F. Example) [Figures 1 to 5] Below is an example illustrating the details of the automobile headlamp of the present invention! Explain according to the following.

(a, reflecting mirror) 2 is a reflecting mirror, and is provided with an upper reflecting surface 3 and a lower reflecting surface 4. The upper reflecting surface 3 has a shape such that the upper half of the paraboloid of revolution remains, and the lower reflecting surface 4 has a shape such that the lower half of the paraboloid of revolution remains.

In this embodiment, the upper reflective surface 3 has a fan-shaped portion 3a that extends slightly downward on the left side.
, and the lower reflective surface 4 is correspondingly smaller. The sector-shaped portion 3a is approximately 1
It is a fan-shaped part with a central angle of 5°. Note that this is adapted to vehicles driving on the left side, and in the case of vehicles driving on the right side, the sector-shaped portion is formed on the right side.

The optical axes of the two reflecting surfaces 3.4 (corresponding to the rotational axes of each paraboloid of revolution) x, -x, and x, -x2 are parallel to each other, and there is a slight interval t vertically. The optical axis Xt −x of the upper reflective surface 3 is shifted.

is located above the optical axis X=-X3 of the lower reflective surface 4.

Furthermore, the focal length of the two reflective surfaces 3.4 is that of the focal path 11F of the upper reflective surface 3, and that of the focal path ml of the lower reflective surface 4.
F* is formed larger than f
1%f is located at approximately the same point when viewed on a plane.

5 is an insertion hole formed in the center of the reflecting mirror 2, and the radius of the lower half 5b is smaller than the radius of the upper half 5a.

(b, light source) 6 is a light source, which in this example is a European standard so-called H
Four types are used.

The light bulb 6 includes a glass bulb, a cap 8 attached to the rear end of the glass bulb 7, two filaments 9 and 10 sealed in the glass bulb 7, and a light-shielding cap covering approximately the lower half of one of the filaments 10. 11, and a light-shielding paint 12 is attached to the front end of the glass bulb 7. The two filaments 9 and 10 each have a coil shape and are arranged to extend along the axis of the glass bulb 7, with the filament 10 being arranged in front of the filament 9.

Such a light bulb 6 is attached to the reflecting mirror 2 by suitable means (not shown), and its glass bulb 7 is placed in the reflecting mirror t2 through the insertion hole 5. The filament 9 is a filament for the traveling beam, and the focus f of the lower reflective surface 4 is
The filament 10 is a filament for a passing beam, and the filament 10 is arranged along the optical axis x, -x of the upper reflective surface 3 and in the upper reflective direction. It is arranged in front of the focal point f1 of the surface 3.

Then, the light-shielding cap shields the low-beam filament 10 from the lower reflective surface 4, so that the light from the low-beam filament 10 is transmitted to the upper reflective surface 3 (including the fan-shaped portion 3a). ) is emitted forward.

Further, the light shielding paint 12 formed on the front end of the glass bulb 7 of the light bulb 6 shields each filament 9.10 from the front, so that the light from each filament 9.10 is transmitted to the reflecting mirror 2.
Only what is reflected by is irradiated forward.

Therefore, in the above configuration, each filament 9,! The light emitted from 0 and reflected by reflection 1i2 is irradiated in a pattern as shown in FIG. In addition, in Fig. 5, )(
-) 1 is the horizontal line in front of the headlight and across the height of the headlight;
V-V is a vertical line passing through a point corresponding to the center of the headlight in front of the headlight.

Since the passing beam filament 10 is shielded from the lower reflective surface 4 by the light shielding cap 11, only the light reflected by the upper reflective surface 3 is irradiated forward, forming the pattern 13 shown in FIG. 5(A). Of this pattern 13 shown in FIG. If it is located on the right side, the above-mentioned portion 13a is also formed on the right side of the v-■ line.

The light emitted from the traveling beam filament 9 passes through the reflective surface 3.4.
5(B), 15 of this pattern 14 is a portion formed by the light reflected by the upper reflective surface 3, and 16 is a portion formed by the light reflected by the lower reflective surface 4. This is the part formed by the light emitted.

As can be clearly seen in FIG. 5(B), the focal pressure M F l of the upper reflective surface 3 is larger than the focal length F2 of the lower reflective surface 4, so the pattern 15 is a small pattern closer to the center. Therefore, the luminous flux density is high, and therefore, a large amount of light is irradiated over a relatively long distance. In addition, the lower reflective surface 4
Since the focal length F2 is relatively small, the reflected light has a large divergence angle with respect to the optical axis x2-x2, and the luminous flux density is low, but the partial pattern 16 created by this light improves front and side visibility. do.

Incidentally, each of FIGS. 5A and 5B shows patterns formed only by the reflecting mirror 2, and these patterns 13 and 14 are controlled by lenses described later to form a desired light distribution pattern. As shown in Fig. 5(B), the original pattern of the traveling beam has a pattern suitable for long-distance visibility and foot visibility, so it is easy to control with the lens, and the desired light distribution can be achieved. A pattern is obtained.

In order to achieve the above effects, the focal pressure 11 F + of the upper reflective surface 3 is 25III11 to 35 mm, the focal length F2 of the lower reflective surface 4 is 15 mm to 25 mm, and the optical axes x, -Xt and x2 of the lower reflective surface 4 are 15 mm to 25 mm. The distance t with -x2 is 0.2
Most preferably, the range is from mm to 1.1 mn+.

(c, Lens) Reference numeral 17 denotes a lens disposed in front of the reflecting mirror 2, on which appropriate lens elements are formed, thereby controlling the light reflected by the reflecting mirror 2.

(G. Effect of the invention) As is clear from the above description, the wooden invention automobile headlamp includes a reflector having an upper reflective surface and a lower reflective surface, two light sources, and two light sources arranged in front of the reflective mirror. The upper and lower reflecting surfaces each have the shape of a paraboloid of revolution cut in half below the road, and their rotation axes (optical axes) are approximately parallel to each other. The optical axis of the upper reflective surface extends in the front-rear direction and is located slightly above the optical axis of the lower reflective surface, and the focal length of the upper reflective surface is larger than the focal length of the lower reflective surface and The focal point of the reflective surface and the focal point of the lower reflective surface are located at approximately the same position, one light source is located approximately parallel to the optical axis of the reflective surface and near the focal point of the lower reflective surface, and the other light source is located near the focal point of the lower reflective surface. a first light shielding means that is arranged approximately parallel to the optical axis of the light source and in front of the focal point of the upper reflective surface and blocks the light from the other light source from the lower reflective surface, and the direct light from the two light sources is directed forward. A second light shielding means for preventing irradiation is provided.

Therefore, in the automobile headlamp of the present invention, of the light from the light source for the running beam, the light reflected by the upper reflective surface is irradiated far away, contributing to long-distance visibility, and is reflected by the lower reflective surface. Since the emitted light has a relatively large spread along the optical axis, it illuminates even relatively near areas, and when driving at high speed over a vast area, by using a traveling beam, it is possible to improve not only long-distance visibility but also so-called foot visibility. This also makes it possible to use the traveling beam as a passing beam when driving at high speeds.

[Brief explanation of the drawing]

1 to 5 show an example of the implementation of the automobile headlamp of the present invention, in which FIG. 1 is a longitudinal sectional view, FIG. 2 is a front view with the lens removed, and FIG. 3 is a reflector. 4 is a schematic vertical sectional view for explaining the positional relationship of each part, FIG. 5 is a light distribution pattern diagram, and FIG. 6 is a schematic vertical sectional view showing an example of a conventional automobile headlamp. It is. Explanation of symbols 1...Car headlight, 2...Reflector, 3...
- Upper reflective surface, 4... Lower reflective surface, one light source, - Other light source, - First light shielding means, - Second light shielding means, - Lens, ... Optical axis of upper reflective surface, ...optical axis of the lower reflective surface, - focal point of the upper reflective surface, - focal point of the lower reflective surface 9...10...11...12...17...X, -X. x, -x2 f+ ・ ・ f2 ・ ・ Applicant Koito Manufacturing Co., Ltd. Schematic longitudinal sectional view Figure 4 Light distribution pattern diagram Figure 5 (A) Light distribution pattern diagram Figure 5 CB)

Claims (1)

[Claims] An automobile headlamp comprising a reflector having an upper reflective surface and a lower reflective surface, two light sources, and a lens disposed in front of the reflective mirror, wherein the upper and lower reflective surfaces are Each has the shape of a paraboloid of revolution cut in half below the road, and their rotation axes (optical axes) extend parallel to each other in the front-rear direction, and the optical axis of the upper reflective surface is exactly the same as the optical axis of the lower reflective surface. located above, and furthermore, the focal length of the upper reflective surface is larger than the focal length of the lower reflective surface, and the focal point of the upper reflective surface and the focal point of the lower reflective surface are approximately the same position when viewed in a plane, and one of the The light source is arranged substantially parallel to the optical axis of the reflecting surface and near the focal point of the lower reflecting surface, and the other light source is arranged substantially parallel to the optical axis of the reflecting surface and in front of the focal point of the upper reflecting surface, An automobile characterized in that it is provided with a first light shielding means for shielding light from a light source from a lower reflective surface, and a second light shielding means for preventing direct light from the two light sources from being irradiated forward. headlights