JP2663308B2 - Automotive headlights - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a novel automotive headlamp. More specifically, the present invention relates to an automotive headlamp using a discharge lamp as a light source, and to provide a novel automotive headlamp that can prevent glare caused by instability of a discharge arc during low beam irradiation. Things.

[0002]

2. Description of the Related Art In a headlamp for an automobile, a reflector is usually used, and a light source is arranged at a predetermined position of the reflector to precisely define a light distribution pattern of reflected light. Shape using a lens according to the desired light distribution (passing
Beam distribution) .

When a discharge lamp is used as a light source for a headlight for an automobile, a discharge arc is unstable and oscillates up and down during a lighting transition period until the discharge state is stabilized and a steady state is reached. , Passing beam irradiation
Even at this time, there is a problem that the positional relationship with the reflecting mirror is broken and an upward glare occurs.

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

[0005] Reference numeral 1 denotes a reflecting mirror, which comprises an upper reflecting surface 2 and a lower reflecting surface 3. Upper and lower reflective surfaces 2,
3 have a paraboloid of revolution, and the positions of the focal points are different from each other.

The central axes XX of the upper and lower reflecting surfaces 2 and 3 coincide with each other, and the upper and lower reflecting surfaces 2 and 3 on a horizontal plane passing through the central axis XX when viewed from the front-rear direction in the half on the traveling lane side. The upper and lower reflecting surfaces 2 and 3 are connected on an inclined plane that descends as it goes sideways through the center axis XX when viewed from the front-rear direction in a half portion on the opposite lane side.

[0007] Reference numerals 4a and 4b denote discharge electrodes, which are spaced apart from each other on the central axis XX. The focal point f2 of the upper reflecting surface 2 is located slightly behind the rear discharge electrode 4b on the central axis XX, and the focal point f3 of the lower reflecting surface 3 is located on the front axis on the central axis XX. It is located slightly forward of 4a.

Reference numeral 5 denotes a discharge arc in a steady state in which discharge is stable, and has a shape that is upwardly curved in an arc shape. Therefore, the light emitted from the discharge arc 5 and reflected by the reflecting mirror 1 is both slightly reflected by the upper reflecting surface 2 and slightly reflected by the lower reflecting surface 3b, and is emitted slightly downward. Is done.

[0009]

By the way, in the discharge lamp, during the lighting transition period from the lighting to the stabilization of the discharge state, the discharge arc is not stabilized, and as shown in FIG. An arcuate state 7 or a swing between 5 and 7 results in an extremely unstable state.

When the light emitted from the discharge arc in the state 7 is reflected by the vicinity 8 of the boundary between the upper and lower reflecting surfaces 2 and 3, as shown in FIG. 13, the light becomes upward light 9a and 9b,
It becomes dazzling light for the driver of the oncoming vehicle and the like, which causes a hindrance to traffic safety.

[0011]

SUMMARY OF THE INVENTION An automotive headlamp according to the present invention has two rotating upper and lower paraboloids in order to solve the above-mentioned problems and to prevent the occurrence of glare caused by the instability of a discharge arc. The discharge electrode is disposed on the rotation axis of the upper reflection surface and is separated from the front and back, and the focal point of the upper reflection surface is located behind the rear discharge electrode, and the focal point of the lower reflection surface. Is located in front of the front discharge electrode and is displaced downward.
Of light that travels near the boundary between the upper reflective surface and the lower reflective surface
A light shielding body is formed in a range that shields most of the light.

[0012]

Therefore, in the headlamp for an automobile according to the present invention as described above, of the light from the discharge arc positioned below the rotation axis in the transitional period of lighting, the light directed to the vicinity of the boundary between the upper and lower reflecting surfaces. Is shielded by the light blocking body, so that the generation of reflected light, which has been glare to the driver of an oncoming vehicle, is prevented.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a vehicle headlamp according to the present invention.

FIGS. 1 to 7 show a first embodiment of a vehicle headlamp according to the present invention.

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

Reference numeral 12 denotes an insulating base of the discharge lamp 11, and two lead supports 13 from the insulating base 12.
a, 13b are projected forward. Reference numeral 14 denotes 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 inner space of the spherical portion 15 is defined as a discharge space, and the tips of the electrode rods 17 project from both ends thereof, and the tips become the discharge electrodes 4a and 4b. Portions other than the tip of the electrode rods 17 are buried in the pinch seal portions 16. Reference numerals 18, 18 denote lead wires, the portions embedded in the pinch seal portions 16, 16 are connected to the electrode rods 17, and a part thereof protrudes from the end faces of the pinch seal portions 16, 16.

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

Reference numeral 19 denotes a cylindrical transparent globe having a closed front end, which is attached to the insulating base 12 so as to cover the lead supports 13a and 13b of the discharge lamp 11 and the glass tube 14. A light shielding film 2 extending in a band shape in the front-rear direction is provided on both left and right side surfaces of the transparent glove.
0a and 20b are formed.

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

That is, first, when viewed from the front, a range in which most of the light traveling from the discharge arc 7 displaced downward to the vicinity 8 of the boundary between the upper and lower reflecting surfaces 2 and 3 is shielded (see FIG. 5). In addition, when viewed in a plane, it may be formed in a range that blocks between the reflecting surfaces 2 and 3 and the discharge arc 7 (see FIG. 2). As a result, most of the light emitted from the discharge arc 7 displaced downward and reflected by the vicinity 8 of the boundary between the upper and lower reflecting surfaces 2 and 3 to become the upward light 9a and 9b is converted to the vicinity 8 of the boundary.
To the oncoming vehicle during the lighting transition period, thereby preventing glare from occurring.

FIGS. 8 to 11 show a second embodiment of the headlamp for a vehicle according to the present invention.

In this embodiment, the lower edge of the upper reflecting surface 2 on the traveling lane side is located 8 mm above the horizontal plane including the central axis X2-X2, and the lower reflecting surface 3 is positioned at the same position as the central axis X2-X2. It extends above the containing horizontal plane. The lower edge of the upper reflecting surface 2 on the side of the opposite lane is inclined downward and to the left when viewed from the front.

The discharge electrodes 4a and 4b are connected to the central axis X2-X.
The focal point f2 of the upper reflecting 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 reflecting surface 3 is located 3 mm below the central axis X2-X2 of the upper reflecting surface 2, and its focal point f3 is on the central axis X3-X3 and the front discharge electrode 4
a.

According to such a configuration, FIG.
As shown in FIG. 9, of the light emitted from the discharge arc 7 displaced downward during the lighting transition period, a region 22 (shown in a satin pattern in FIG. 9) in contact with the boundary 21 between the upper and lower reflecting surfaces 2, 3 of the lower reflecting surface 3. )) Is reflected upward to produce glare 23,
23, and so on.

If the light shielding films 20a and 20b are arranged so as to shield most of the light from the discharge arc 7 displaced downward toward the region 22 from the discharge arc 7, the glare 23, 23,.・ Prevention of occurrence can be prevented.

The lower edge of the upper reflecting surface 2 is defined by its central axis X2.
When it is located above 8 mm above -X2, the upper edge of the light distribution pattern sags too much, and the visibility in the distance decreases. Further, as the central axis X3-X3 of the lower reflecting surface 3 is positioned lower than the portion where the discharge electrodes 4a and 4b are located, glare caused by the discharge arc 7 displaced downward decreases,
If it is lowered too much, the brightness in front of the road surface becomes too bright, making it difficult to drive, and practically up to 3 mm.

In each of the above embodiments, the light shielding body is 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 this. For example, it may be formed separately from the discharge lamp and the transparent globe.

Further, a lens or the like for covering the front opening of the reflecting mirror 1 is necessary to be a headlamp for an automobile, but these are portions which are not directly related to the gist of the present invention, and the description thereof will be omitted. .

[0030]

As is apparent from the above description, the automotive headlamp of the present invention has two upper and lower revolving paraboloidal reflecting surfaces, and is separated from the front and rear on the rotation axis of the upper reflecting surface. The discharge electrode is disposed, 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 ahead of the front discharge electrode, and the discharge displaced downward. arc
Of light from near the boundary between the upper reflective surface and the lower reflective surface
A light-shielding body is formed in an area where the portion is shielded .

Therefore, in the automotive headlamp of the present invention, the light from the discharge arc located below the rotation axis toward the vicinity of the boundary between the upper and lower reflecting surfaces in the transition period of lighting is transmitted to the light shield. Since the light is blocked, the generation of reflected light, which has been glare to the driver of the oncoming vehicle, is prevented.

[Brief description of the drawings]

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

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

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

FIG. 4 is a schematic front view for explaining a problem when there is no light-shielding member.

FIG. 5 is a schematic front view illustrating a position of a light shielding body.

FIG. 6 is a schematic vertical sectional view showing light traces in a steady state.

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

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

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

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

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

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

FIG. 13 is a schematic vertical sectional view showing a problem of a conventional automotive headlamp.

[Explanation of symbols]

2 Upper reflective surface 3 Lower reflective surface 4a Front discharge electrode 4b Rear discharge electrode 7 Discharge arc 8 displaced to the lower side 20a, 20b Near boundary between upper reflective surface and lower reflective surface 20a, 20b Shield Upper Rotation axis of reflection surface f2 Focus of upper reflection surface f3 Focus of lower reflection surface X2-X2 Rotation axis of upper reflection surface

Claims (1)

(57) [Claims] An upper reflective surface is provided with two upper and lower paraboloidal reflective surfaces, and a discharge electrode is disposed on the rotational axis of the upper reflective surface so as to be separated from the front and back. Located behind the electrode, the focal point of the lower reflective surface is located in front of the front discharge electrode, and the upper reflection from the discharge arc displaced downward
Block most of the light going near the boundary between the surface and the lower reflective surface
Characterized by forming a light-shielding body in a range of