JPH0337245B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automobile headlamp, and in particular has a filament that is perpendicular to the optical axis and horizontal, such as H6 halogen lamp, C6/C6 lamp, C6 lamp, etc.
This invention relates to an automobile headlamp that uses a C6 type lamp as a light source.

Figure 1 shows an example of this type of automobile headlight.
Indicates a car headlight with a C6/C6 lamp,
The illustrated Z-Z axis is the optical axis of the headlamp.

In this conventional example, a reflector 2 is constructed by providing a reflective surface on the inner surface of a reflector body 1 made of synthetic resin.

The above reflector 2 is formed into a paraboloid of revolution,
A C6/C6 lamp 3 is provided near the focal point, and a lens 4 is attached to cover the front opening.

Incidentally, without being limited to this example, there is a type of conventional headlight in which a lens 4 is attached to the front opening of a lamp housing that supports the reflector 2 in a freely adjustable angle, and covers the front opening of the reflector 2. be.

Figure 2 is an external view of the above C6/C6 lamp as seen from the front in the direction of arrow A. It shows the direction.

Main filament 3a for C6/C6 lamp 3
and a supply filament 3b are provided parallel to the X-X axis, and a main filament 3a
The light is mainly used as the main light for night driving.
The light from the subfilament 3b is mainly used for auxiliary lighting to illuminate your own lane when passing an oncoming vehicle. For this reason, a light shielding plate 3c is provided above the subfilament 3b.

Conventionally, the above-mentioned reflector 2 is generally constructed of a single paraboloid of revolution, so that both the light emitted from the main filament 3a and the light emitted from the sub-filament 3b are located along the optical axis in a portion corresponding to a specific area to be described later. It is reflected toward the front in a substantially parallel direction along Z-Z. For this reason, the lens 4 must be configured with a prism lens to direct the light reflected by the reflector slightly downward and to diffuse it left and right. C6/
Similar problems exist in lamps other than C6 lamps, such as C6 type lamps having filaments substantially parallel to the X-X axis.

In order to provide a prism in the lens 4 and direct the reflected light from the reflector downward, it is necessary to provide a step of 4° to 6° vertically, and in addition to this, a horizontal radius must be provided to diffuse the light left and right. Therefore, the lens thickness becomes larger and the riser also becomes larger. For this reason, () lens moldability is poor, ()
It is disadvantageous in terms of light distribution due to light clumps and unevenness from the riser, and (2) there is a problem that the product value is low because it has a thick feeling and lacks a clear feeling.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a headlamp equipped with a reflector that can reflect light emitted from a filament perpendicular and parallel to the optical axis into a substantially desired light distribution pattern. do.

If the light reflected by the reflector has approximately the desired light distribution pattern, there is no need for the lens to significantly modify the reflected light, and a nearly transparent flat lens will suffice. Therefore, the moldability of the lens is good,
The cost of the lens is low, and furthermore, it can be expected that the product value in terms of appearance will be improved.

In order to achieve the above object, the automobile headlamp of the present invention divides the reflective surface of the reflector into ()
An area consisting of a pair of upper right and lower left, and ()
One of the areas consisting of the upper left and lower right areas (hereinafter referred to as the specified area) is defined, and the reflecting surface other than the above specified area is composed of a paraboloid of revolution; The area is formed into a curved surface having a plurality of circular arcs whose vertical cross section is a parabola and whose horizontal cross section is approximately tangent to the paraboloid of revolution, and the parabola of the curved surface is at the focal point of the paraboloid of revolution. It is characterized in that it has a focal point at approximately the same position and a focal axis that is directed downward from the focal axis of the paraboloid of revolution. However, whether to use the area in () or the area in () as the above specified area depends on the road traffic regulations of the area where the vehicle equipped with the headlights is to be used (whether it is driving on the right or left).
Defined based on.

Next, an embodiment of the present invention will be described with reference to FIGS. 3 to 12.

FIG. 3 is a front view of a reflector 2' in an embodiment of the present invention, and FIG. 4 is a Y-axis view of the reflector 2'.
The Y sectional view and FIG. 5 are also XX sectional views.
FIG. 6 is a vertical cross-sectional view of an automobile headlamp equipped with the above reflector 2'.

As shown in FIG. 3, an upper left P ₁ and a lower right P ₂ are set on the reflective surface of the reflector 2'. 2a is an opening for attaching a lamp.

The area other than the specific area consisting of the upper left P ₁ and the lower right P ₂ set as above is named P ₃ .

The reflecting surface in the P ₃ area described above is constructed into a paraboloid of revolution so that its vertical cross section becomes a parabola P ₃ as shown in FIG. The paraboloid of revolution in the _P3 area is configured so that the optical axis Z--Z of the headlamp is the focal axis. In the figure, F is a focal length, and f is a focal position.
As shown in FIG. 6, the C6/C6 lamp 3 is installed so that its main filament 3a substantially coincides with the focal point f.

The specific areas P ₁ and P ₂ are arranged so that their vertical cross section forms a parabola P ₁ as shown in FIG. 4, and their horizontal cross section forms a series of many circular arcs P′ ₁ as shown in FIG. Form a curved surface. Specifically, each cross section taken along a vertical plane parallel to the optical axis Z-Z forms a parabola. The parabola P ₁ shown in FIG. 4 is one example. Each of the above parabolas is formed so as to share the focal point f with the parabola _P3 , with its focal axis being an axis Z' that is tilted downward by an angle θ with respect to the optical axis Z-Z.
Furthermore, the series of arcs P′ ₁ is the parabola P ₁
Formed so that it is in contact with.

Next, the optical path of the light reflected by the reflector 2' configured as above will be explained.

As mentioned above, the P ₃ area other than the specific area is a paraboloid of revolution with the optical axis Z-Z as its focal axis, so if the light emitted near the focal point f is reflected by the paraboloid of revolution in the P ₃ area, , horizontally as shown by arrow g in FIG. 4, and straight toward the front as shown by arrow g' in FIG.

In addition, as shown in Figure 4, the specific area _P1 is
Its vertical cross section forms a parabola P ₁ with axis Z' as the focal axis, so the light emitted from around the focal point f is transmitted to a specific area.
When reflected by P ₁ , the reflected light is reflected downward by an angle θ from the horizontal as indicated by arrow h. Fourth
Although not shown in the figure, the light reflected from area P ₂ similarly goes downward by an angle θ. Furthermore, since the horizontal section of the above specific area forms _a group of arc-shaped curves P′ ₁ as shown in FIG. The part that reflects toward the front as shown by the arrow h' ₁ , the part that reflects towards the inside as shown by the arrow h' ₂ , and the part that reflects towards the outside as shown by the arrow h' ₃ . It also spreads to the left and right.

To summarize the above reflection conditions,
The reflected light in the P ₃ area becomes a horizontal parallel light beam heading toward the front, and the reflected light in the specific areas P ₁ and P ₂ is reflected downward by an angle θ and diffused to the left and right.

In this embodiment, the above angle θ is set to 2.5°. When implementing the present invention, good results are obtained when the angle θ is set between 1° and 4°.

FIGS. 7 to 10 are charts showing light distribution patterns of reflected light by the reflector.

Em ₁ shown with diagonal lines in FIG. 7 is the light distribution area of the main filament light reflected by the reflective surface in the P ₁ area. Em ₀ shown with spots is added for comparison, and is the light distribution area when the P ₁ area is composed of a single paraboloid of revolution and the focal axis is not tilted downward. . In the figure, the numbers appended to the left and right lines H-H and the upper and lower lines V-V indicate the deflection angle (unit degree) with respect to the optical axis Z-Z.

Es ₁ shown with diagonal lines in FIG. 8 is the light distribution area of the subfilament light reflected by the reflective surface of the P ₁ area. Es ₀ shown with spots is the light distribution area when the P ₁ area is composed of a single paraboloid of revolution and the focal axis is not tilted downward.

Em ₂ shown with diagonal lines in FIG. 9 is the light distribution area of the main filament light reflected by the reflective surface in the P ₂ area. Em′ ₀ shown with spots is added for comparison, and is the light distribution area when the P ₂ area is composed of a single paraboloid of revolution and the focal axis is not tilted downward. be.

Es ₂ shown with diagonal lines in FIG. 10 is the light distribution area of the subfilament light reflected by the reflective surface of the P ₂ area. Es′ ₀ shown with spots is the light distribution area when the P ₂ area is composed of a single paraboloid of revolution and the focal axis is not tilted downward.

In this embodiment, as described above, the light reflected by the reflective surfaces in the specific areas (P ₁ and P ₂ ) is directed downward from the horizontal and is diffused to the left and right. Also,
The light reflected by the paraboloid of rotation in the P ₃ area other than the specific area becomes a horizontal parallel beam of light. In this way, the reflected light above has almost the desired light distribution pattern before being adjusted with the lens, and the corrections necessary to project these reflected lights as the final desired light distribution pattern are necessary. is only a small amount. Therefore, a simple lens shape is sufficient, and the lens does not become thick due to prisms with large steps or radiuses for diffusion. For this reason, the manufacturing cost of the lens is low, and the lens has a clear appearance.

FIG. 11 shows the light distribution pattern after the light from the main filament passes through the lens in this embodiment, and FIG. 12 similarly shows the light distribution pattern after the light from the sub-filament passes through the lens.

Em _1,2 shown in FIG. 11 is an area of projected light formed by the reflected light of area Em ₁ shown in FIG. 7 and the reflected light of area Em ₂ shown in FIG. 9. Furthermore, area Em ₃ in FIG. 11 is an area of projected light formed by light from the main filament that is reflected by area P ₃ of the reflector.

Es _1,2 shown in Fig. 12 is the area of the projected light formed by the reflected light of area Es ₁ shown in Fig. 8 and the reflected light of area Es ₂ shown in Fig. 10. . Furthermore, the area Es ₃ in FIG. 12 is an area of projected light formed by the light of the subfilament reflected by the area P ₃ of the reflector.

As detailed above, according to the present invention, in an automobile headlamp whose light source is a lamp having a horizontal filament perpendicular to the optical axis, the light reflected by the reflector is reflected in a substantially desired light distribution pattern. Therefore, the lens structure is simple, the moldability of the lens is good, the cost of the lens is low, and the commercial value of the lens is increased in terms of appearance.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of an automobile headlamp using a C6 type lamp, Figure 2 is an external view of the above C6 type lamp as seen in the direction of arrow g in Figure 1.
3 to 12 show an embodiment of the present invention,
Figure 3 is a front view of the reflector, Figure 4 is the same Y-Y
5 is a sectional view taken along the line XX, FIG. 6 is a vertical longitudinal sectional view, FIGS. 7 to 10 are charts showing the light distribution pattern of reflected light by the reflector, and FIGS. 11 and 12. is a chart showing a light distribution pattern of light passing through a lens. 1... Reflector body, 2, 2'... Reflector, 2a... Opening for attaching lamp, 3...
C6/C6 lamp, 3a...main filament,
3b...subfilament, 3c...shading plate,
4,4'...lens.

Claims (1)

[Claims] 1. In an automobile headlamp comprising a lamp equipped with a horizontal filament in a direction perpendicular to the optical axis near the focal point of a paraboloid of revolution reflector, the reflective surface of the reflector is divided into () upper right corner. The area consisting of the pair of `` and the lower left'' and the area consisting of the pair of the upper left and the lower right (hereinafter referred to as the specified area) are defined, and areas other than the above specified area are defined. The reflective surface is composed of a paraboloid of revolution, and the specific area is composed of a curved surface having a plurality of circular arcs whose vertical cross section is a parabola and whose horizontal cross section is almost tangent to the paraboloid of revolution, and The parabola has a focal position substantially equal to the focal point of the paraboloid of revolution, and has a focal axis pointing downward than the focal axis of the paraboloid of revolution. light.