JPS61259401A - Head lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a headlamp such as an automobile headlamp.
The present invention relates to a headlamp having a structure in which a light source is provided near the focal point of a concave mirror and a lens is attached to cover the front opening of the concave mirror.

[Background of the invention]

This type of headlamp is widely used as a headlamp for automobiles. FIG. 7 shows a front view of the conventional example, FIG. 8 shows a horizontal sectional view, and FIG. 9 shows a vertical sectional view.

Conventional headlights of this kind generally have the concave mirror configured as a paraboloid of revolution mirror 1, and transform the light beam emitted from the light source bulb 2 and reflected by the paraboloid of revolution 1 into a substantially horizontal parallel light beam. (If the light source bulb 2 is equipped with a turn filament and a sub-filament, the light from the turn filament is made into an almost horizontal parallel light beam, and the light from the sub-filament is made into a slightly downward light beam), and these reflected light beams are The light is diffused through the lens 5 as appropriate to obtain a desired light distribution and main turn. zz' is the optical axis.

In order to obtain the above function, the lens 5 is generally provided with a grism 6. This grism has both the function of dimming the light flux of the turn filament to provide lighting for normal driving and turning, and the function of dimming the luminous flux of the sub-filament to produce lighting for passing each other and 9 turns. Prism design is technically difficult because
In addition to various restrictions on obtaining an ideal illumination level, prism lenses are expensive to manufacture and are heavy.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and provides a lens that is technically easy to design, has a large degree of freedom in design design, is inexpensive and lightweight, and has an ideal layout. light·! The aim is to provide a headlight that can be used to turn the vehicle.

[Summary of the invention]

In order to achieve the above object, the headlamp of the present invention has a reflecting surface of a reflecting mirror having a shape similar to a paraboloid of revolution, so that the luminous flux emitted from the light source bulb and reflected by the pseudo paraboloid of revolution is It is configured to diffuse approximately 9 degrees to the left and right in the horizontal plane, and within a range of 8 degrees from approximately horizontal to downward in the vertical plane, and the lens surfaces have different transmittances. It is characterized by having multiple areas.

[Embodiments of the invention]

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 6.

In this embodiment, the present invention is applied to a four-lamp type automobile headlamp. Of the four headlights mentioned above, the inner two are headlights with a light source/group equipped with only a turn filament (referred to as type I), and the outer two are headlights with a turn filament and a sub-light source. This is a headlamp (referred to as type ■) that is equipped with a light source and group equipped with a filament.

The headlight of this embodiment is equipped with pseudo-paraboloid mirrors of revolution having the same shape and dimensions in both the tie fI and the tie f. 6 indicated by a chain line in FIG. 3 indicates a horizontal section of the pseudo parabolic mirror of revolution,
z' is the optical axis.

The solid line P drawn in FIG. 3 represents a paraboloid of revolution for comparison, and F is its focal point.

The pseudo paraboloid of revolution mirror 6 of this example has a shape that is expanded compared to the paraboloid of revolution P (that is, a shape that is spaced apart from the optical axis z-z').

When the light emitted from the focal point F as indicated by arrows a and a' is reflected by the paraboloid of revolution P, it becomes a luminous flux that is almost parallel to the optical axis z-z' as indicated by arrows a and b'. When reflected at 6, it becomes a diffused beam of light as shown by arrows c and b'.

In this embodiment, the configuration is such that the maximum diffusion angle is 30 degrees to the left.

In Fig. 4, 6' drawn with a chain line indicates the vertical cross section of the above-mentioned pseudo paraboloid of revolution, y drawn with a solid line is the paraboloid of revolution shown for comparison, and z - z' indicates the above-mentioned paraboloid of revolution. It is the optical axis of the object surface.

The pseudo parabolic mirror of this example is constructed so that its vertical cross-sectional shape is approximately a parabola, and its axis of symmetry 2-z' is directed downward by approximately 4 degrees from the horizontal.

When the light emitted from the focal point F is reflected by the paraboloid of revolution P', it becomes almost horizontal as shown by the solid arrow d, but the pseudo paraboloid of revolution 6
When reflected by ', the light turns downward by about 4 degrees, as shown by the dashed arrow.

In conventional headlights, the light from the turn filament reflected by the rotating parabolic mirror is diffused left and right by the prism lens mentioned above, and as a result of being dimmed, it becomes as shown by the two-dot chain line in Figure 5. It has a light distribution pattern and serves as a lighting function for normal driving. In addition, the light emitted from the sub-filament is diffused and dimmed to the left and right by the prism lens, creating a light distribution/4' turn as shown by the two-dot chain line in Figure 6, which serves as a lighting function for passing each other. .

FIG. 3 shows a headlamp to which the present invention is applied.

As explained with reference to Figure 4, the light beam reflected by the pseudo-rotating parabolic mirror is diffused left and right (approximately 30 degrees) and slightly downward (within 8 degrees), so this is reflected by the prism. There is no need to spread it. Therefore, in the headlight of this example, the lens surface is divided into sections such as lens 7 (for type I) shown in Fig. 1 and lens 8 (for type ■) shown in Fig. 2 to reduce the difference in shading. to make the transmittance of each area different.

Part A of the lens 7 for Taigu ■ shown in Figure 1 has a transmittance of 10.
Part B is a flat fogged lens with 70% transmittance, part 0 is a flat fogged lens with 80% transmittance, and part D is a flat bone lens with 50% transmittance. When the front is irradiated through the lens 7 configured in this way, the light beam that passes through the A part of the lens illuminates the A' zone shown by the solid line in Figure 5 most brightly, and the light that has passed through the B part of the lens 70 times The light that illuminates the B' zone in Figure 5 relatively briefly (70% of the illumination intensity of the A' zone) and passes through 80 inches at the 0 part of the lens illuminates the C' zone in Figure 5 very brightly (A'). 80% of zone A') and 50% of the light transmitted through the D section of the lens illuminates zone D' in Figure 5 with a slightly lower illuminance (50% of zone A').
n), which provides ideal illumination for normal driving.

Part E and G of lens 8 for type ■ shown in Figure 2 are clear lenses with a transmittance of 100%, part 5 is a flat plate-like foggy lens with a transmittance of 50 inches, and part K is a flat plate with a transmittance of 70%. Condition IIk
The L part is made of a plate-like bone lens with a transmittance of 10 cm. Lens 8 configured in this way
When irradiating the front through the lens, the light flux that passed through the E and G parts of the lens will most brightly illuminate the E' and G' zones in Figure 6, and the light that has passed 50% through the 5th part of the lens will be the 6th.
Brighten the J' zone in the diagram ((g/, C/zone 50
% illuminance), and the light that transmitted 70% in the N part of the lens illuminates the N' zone in Figure 6 even brighter ((E part, 70% of C/zone), and furthermore, the L part of the lens is illuminated. The light that has transmitted 10% has a slight illuminance (H/, C
/ zone), but there is no risk of dazzling oncoming vehicles. In this way, ideal illumination for passing vehicles is achieved.

As is clear from the above-mentioned structural function, the "reflecting surface similar to a paraboloid of revolution" in the headlamp of the present invention has a horizontal cross section that is a deformed parabola, and a vertical cross section that is similar to a parabola. You can get the same effect if you do. Therefore, the horizontal cross section may be a hyperbola, and the vertical cross section may be almost a parabola.

Further, parts A to L shown in FIGS. 1 and 2 are partitions shown as an example, and when carrying out the present invention, the number and shape of these partitions can be set arbitrarily. It is possible. Further, the transmittance of each section can be set arbitrarily, and there is no problem with the existence of areas with equal transmittance.

Furthermore, if the present invention is applied, the desired nine turns of light distribution can be obtained without providing any prisms in the lens, as in the above-mentioned embodiments (Figs. 1 and 2), making lens design easy. , the lens is lightweight and low cost. However, when implementing the present invention, this does not preclude the use of a prism as an auxiliary lens.

〔Effect of the invention〕

As detailed above, when the headlight of the present invention is applied, the lens design is technically easy, and therefore there is a large degree of freedom in the design, and the lens is lightweight and inexpensive, making it an ideal It has an excellent practical effect of providing lean light distribution.

[Brief explanation of the drawing]

FIGS. 1 and 2 are front views of lenses in one embodiment of the present invention, respectively. FIG. 3 is a horizontal sectional view of a pseudo parabolic mirror of revolution according to an embodiment of the present invention, and FIG. 4 is a vertical sectional view of the same. FIGS. 5 and 6 are charts showing light distribution and turn in one embodiment of the present invention, respectively. 7 to 9 show a conventional headlamp, in which FIG. 7 is a front view, FIG. 8 is a horizontal sectional view, and FIG. 9 is a vertical sectional view. 1... Rotating parabolic mirror, 2... Light source/Glube, 3...
・Turn filament, 4 pa・sub filament, 5・
...Lens, 6...Horizontal section of pseudo-rotating parabolic mirror, 7
...Same vertical section, 7, 8...lens.

Claims (1)

[Claims] In a headlamp in which a light source bulb is provided near the focal point of a concave mirror and a lens is attached to cover the front opening of the concave mirror, a reflecting surface similar to a paraboloid of revolution is formed on the concave mirror, and the light source bulb is The lens is configured such that the light beam that exits and is reflected on the reflective surface is diffused by approximately 30 degrees to the left and right in a horizontal plane, and is diffused approximately horizontally or downward within a range of 8 degrees in a vertical plane, and A headlamp characterized in that a plurality of areas having mutually different transmittances are provided on a surface.