JPH04249801A - Automotive headlight - Google Patents

Abstract

PURPOSE:To prevent generation of the reflected light as the glare against a driver or the like by installing shading films extending forward and backward in bilateral sides of a transparent globe of a discharge lamp fitted in a central part of two reflecting surfaces of the upper and the lower. CONSTITUTION:Two reflecting surfaces 2, 3 are provided in the upper and the lower, and a discharge lamp 11 is fitted to a lamp fitting hole 10 of a central part. Shading films 20a, 20b extending forward and backward are formed in bilateral sides of a transparent globe 19. Incidence of almost part of the light, which is emitted from a discharge arc 7 dislocated downward, reflected upward near a boarder of the reflecting surfaces 2, 3 is hindered to prevent generation of the glare.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel automobile headlamp. Specifically, the present invention relates to an automobile headlamp that uses a discharge lamp as a light source, and aims to provide a novel automobile headlamp that can prevent the occurrence of dazzling light caused by instability of the discharge arc.

0002

[Prior Art] Automobile headlights usually use a reflector and place a light source at a predetermined position on the reflector to strictly control the light distribution pattern of the reflected light. A lens is used to shape the light according to the desired light distribution.

By the way, when a discharge lamp is used as a light source for an automobile headlamp, the discharge arc becomes unstable and oscillates up and down during the lighting transition period until the discharge state stabilizes and reaches a steady state. , there is a problem in that the positional relationship with the reflecting mirror collapses, causing upward glare.

FIG. 12 shows an example of a conventional automobile headlamp.

Reference numeral 1 denotes a reflecting mirror, and the reflecting mirror 1 has an upper reflecting surface 2 and a lower reflecting surface 3. Upper and lower reflective surfaces 2,
All three have the shape of a paraboloid of revolution, and the positions of their focal points are different from each other.

The central axes XX of the upper and lower reflective surfaces 2 and 3 are aligned, and the upper and lower reflective surfaces 2 and 3 are aligned on a horizontal plane passing through the central axis XX when viewed from the front and rear directions in the half part on the driving lane side. The upper and lower reflective surfaces 2 and 3 are connected on an inclined plane that passes through the central axis XX and descends laterally when viewed from the front and back directions in the half portion on the opposite lane side.

Reference numerals 4a and 4b are discharge electrodes, which are arranged spaced apart from each other on the central axis XX. The focal point f2 of the upper reflective surface 2 is located slightly behind the rear discharge electrode 4b on the central axis XX, and the focal point f3 of the lower reflective surface 3 is located on the central axis XX at the front discharge electrode 4b. It is located slightly in front of 4a.

Reference numeral 5 indicates a discharge arc in a steady state in which the discharge is stable, and has an upwardly arched shape. Therefore, the light emitted from such a discharge arc 5 and reflected by the reflecting mirror 1 is emitted slightly downward in both the light reflected by the upper reflective surface 2 6a and the light reflected by the lower reflective surface 3 6b. be done.

[0009]

[Problems to be Solved by the Invention] However, in a discharge lamp, during the lighting transition period from lighting to stabilization of the discharge state, the discharge arc is not stabilized and as shown in FIG. It is in an extremely unstable state, with the state 7 being warped in an arc shape, or swinging between the states 5 and 7.

When the light emitted from the discharge arc in state 7 is reflected near the boundary 8 between the upper and lower reflective surfaces 2 and 3, it becomes upward light 9a and 9b, as shown in FIG.
This creates a dazzling light for the drivers of oncoming vehicles and impedes traffic safety.

[0011]

[Means for Solving the Problems] In order to solve the above-mentioned problems and prevent the occurrence of glare caused by instability of the discharge arc, the automobile headlamp of the present invention has two upper and lower paraboloids of revolution. The discharge electrodes are arranged spaced apart in the front and back on the rotation axis of the upper reflective surface, the focal point of the upper reflective surface is located behind the rear discharge electrode, and the focal point of the lower reflective surface is positioned on the front side. The lower end of the portion of the upper reflective surface on the diagonal line side of the rotation axis is located above the rotation axis, and a light shield is placed on the side of the discharge electrode. The upper edge of the body is located slightly below the horizontal plane containing the discharge electrode.

0012

[Function] Therefore, in the automobile headlamp of the present invention as described above, among the light from the discharge arc located below the rotation axis during the lighting transition period, the light directed toward the vicinity of the boundary between the upper and lower reflective surfaces. Since the light is blocked by the light shielding body, the generation of reflected light, which conventionally caused dazzling to the driver of an oncoming vehicle, is prevented.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the automobile headlamp of the present invention will be explained in detail below according to the illustrated embodiments.

1 to 7 show a first embodiment of an automobile headlamp according to the present invention.

The reflecting mirror 1 has a substantially oblong rectangular shape when viewed from the front, and has a lamp mounting hole 10 formed in its center, into which a discharge lamp 11 is mounted.

Reference numeral 12 denotes an insulating base of the discharge lamp 11, and from the insulating base 12 two lead supports 13a,
13b protrudes forward. Reference numeral 14 designates a glass tube, which is formed integrally with a central spherical portion 15 and pinch seal portions 16, 16 protruding from both front and rear ends of the spherical portion 15. The internal space of the spherical portion 15 is used as a discharge space, and the tip portions of the electrode rods 17, 17 are protruded from both ends thereof, and the tip portions become the discharge electrodes 4a, 4b. The portions other than the tips of the electrode rods 17, 17 are pinch seal portions 1.
It is buried in 6, 16. Reference numerals 18 and 18 are lead wires, and the portions buried within the pinch seal portions 16 and 16 are connected to the electrode rods 17 and 17, and portions thereof protrude from the end surfaces of the pinch seal portions 16 and 16.

The lead wires 18, 18 are supported by the lead supports 13a, 13b, and thereby the glass tube 14 is supported by the insulating base 12. and,
An insulating base 12 is attached to the lamp attachment hole 10 of the reflecting mirror 1.

Reference numeral 19 is a cylindrical transparent globe with a closed front end, and is attached to the insulating base 12 so as to cover the lead supports 13a, 13b and the glass tube 14 of the discharge lamp 11. On both the left and right sides of this transparent glove, there is a light shielding film 2 that extends in a band shape in the front and back direction.
0a and 20b are formed.

The light shielding films 20a and 20b are formed in the following range.

That is, when viewed from the front, the area covers most of the area from the downwardly displaced discharge arc 7 to the boundary area 8 between the upper and lower reflective surfaces 2 and 3 (see FIG. 5).
Also, when viewed from above, it may be formed in a range that blocks the gap between the reflective surfaces 2 and 3 and the discharge arc 7 (see FIG. 2). As a result, most of the light that is emitted from the discharge arc 7 that is displaced downward and is reflected at the boundary area 8 between the upper and lower reflective surfaces 2 and 3 to become upward light beams 9a and 9b is prevented from being incident on the boundary area 8. This prevents the occurrence of dazzling to the driver of an oncoming vehicle during the lighting transition period.

FIGS. 8 to 11 show a second embodiment of the automobile headlamp of the present invention.

In this embodiment, the lower edge of the upper reflective surface 2 on the driving lane side is located 8 mm above the horizontal plane including the central axis X2-X2, and the lower reflective surface 3 is located 8 mm above the horizontal plane including the central axis X2-X2. It extends above the horizontal plane that contains it. Further, the lower edge of the upper reflective surface 2 on the opposite lane side is inclined downward to the left when viewed from the front.

The discharge electrodes 4a, 4b are arranged along the central axis X2-X.
The focal point f2 of the upper reflective surface 2 is located slightly behind the rear discharge electrode 4b on the central axis X2-X2.

The central axis X3-X3 of the lower reflective surface 3 is located 3 mm below the central axis X2-X2 of the upper reflective surface 2, and its focal point f3 is on the central axis X3-X3 and is located on the front discharge electrode 4a. It is located slightly in front of.

According to such a configuration, FIG.
As shown in , among the light emitted from the discharge arc 7 that is displaced downward during the lighting transition period, the upper and lower reflective surfaces 2 of the lower reflective surface 3
, 3, the light incident on the area 22 (shown with a satin pattern in FIG. 9) is reflected upward and causes glare 23, 2.
3,...

Therefore, if the light-shielding films 20a and 20b are arranged so as to block most of the light directed toward the region 22 from the downwardly displaced discharge arc 7, the dazzling light 23, 23, . . .・It is possible to prevent the occurrence of

Note that the lower edge of the upper reflective surface 2 is defined by its central axis
If it is located more than 8 mm above -X2, the upper edge of the light distribution pattern will hang down too much, resulting in poor long-distance visibility. Furthermore, as the central axis X3-X3 of the lower reflective surface 3 is positioned lower than the portion where the discharge electrodes 4a and 4b are located, the glare caused by the discharge arc 7 displaced downward is reduced, but if it is lowered too much, the road surface There is a problem that the brightness in the foreground becomes too bright, making it difficult to drive, so a maximum of 3 mm is practical.

In each of the above embodiments, the light shielding body was formed by applying a light shielding film to the transparent globe 19 attached to the discharge lamp 11, but the formation of the light shielding body is not limited to such a method. For example, it may be formed separately from the discharge lamp and the transparent globe.

[0029] Further, in order to serve as an automobile headlamp, a lens and the like are required to cover the front opening of the reflector 1, but since these are not directly related to the gist of the present invention, their explanation will be omitted. .

[0030]

[Effects of the Invention] As is clear from the above description, the automobile headlamp of the present invention is provided with two upper and lower reflecting surfaces in the shape of a paraboloid of revolution, which are spaced apart from each other on the axis of rotation of the upper reflecting surface. The discharge electrodes are arranged so that the focal point of the upper reflective surface is located behind the rear discharge electrode, the focal point of the lower reflective surface is located forward of the front discharge electrode, and the rotation axis of the upper reflective surface is The lower end of the part closer to the driving lane includes the rotation axis and is located above it, and a light shield is placed on the side of the discharge electrode, and the upper edge of the light shield is slightly lower than the horizontal plane containing the discharge electrode. It is characterized by being located in

Therefore, in the automobile headlamp of the present invention, during the lighting transition period, the light directed toward the vicinity of the boundary between the upper and lower reflective surfaces from the discharge arc located below the rotation axis is absorbed by the light shielding member. Since the light is blocked, the generation of reflected light, which would conventionally dazzle the driver of an oncoming vehicle, is prevented.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a first embodiment.

FIG. 2 is a sectional view taken along line II-II in FIG. 1;

FIG. 3 is an enlarged side view of the discharge lamp.

FIG. 4 is a schematic front view illustrating a problem when there is no light shield.

FIG. 5 is a schematic front view illustrating the position of a light shield.

FIG. 6 is a schematic vertical cross-sectional view showing a light trail in a steady state.

FIG. 7 is a schematic vertical sectional view showing a light trail when the discharge arc is displaced downward.

FIG. 8 is a schematic front view showing a second embodiment.

FIG. 9 is a schematic front view illustrating a problem when there is no light shielding body.

FIG. 10 is a schematic vertical end view showing a light trail in a steady state.

FIG. 11 is a schematic vertical sectional view showing a light trail when the discharge arc is displaced downward.

FIG. 12 is a schematic vertical sectional view showing an example of a conventional automobile headlamp.

FIG. 13 is a schematic vertical sectional view showing problems with a conventional automobile headlamp.

[Explanation of symbols]

2 Upper reflective surface 3 Lower reflective surface 4a Front discharge electrode 4b Rear discharge electrode 20a, 20b Light shielding body X-X Rotation axis of upper reflective surface f2　Focus of upper reflective surface f3 Focus of lower reflective surface X2-X2 Rotation axis of upper reflective surface

Claims (1)

[Claims] Claim 1: The upper and lower reflective surfaces are provided with two reflective surfaces in the shape of paraboloids of revolution, and discharge electrodes are arranged spaced apart in the front and back on the rotational axis of the upper reflective surface, and the focal point of the upper reflective surface is the rear discharge electrode. Located behind the electrode, the focal point of the lower reflective surface is located in front of the front discharge electrode, and the lower end of the portion of the upper reflective surface that is closer to the driving lane than the rotation axis includes the rotation axis and is located above it. A headlamp for an automobile, characterized in that a light shielding body is arranged on the side of the discharge electrode, and the upper edge of the light shielding body is located slightly below a horizontal plane containing the discharge electrode.