JPH028327Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an automobile headlamp equipped with a light source bulb (of the so-called C-6 type) having a filament in a direction perpendicular to the optical axis. be.

[Conventional technology]

FIG. 1 shows an example of this type of headlamp, in which a reflector 11 in the shape of a paraboloid of revolution is formed on the back surface of a lamp housing 1. Z-Z is its optical axis.

A lens 2 is attached to cover the front opening of the lamp housing 1, and a reflector 1
A light source bulb 3 is installed near the focal point of the light source 1 .

31 is a main filament, 32 is a sub-filament, and 33 is a light shielding plate.

External views of the light source bulb 3 as seen in the direction of arrow A are shown in FIGS. 2 and 3. Figure 2 is for foreign countries such as North America, where vehicles drive on the right, and Figure 3 is for domestic vehicles, where traffic is on the left. In both cases, the main filament 31 is located at the focal point f, and the sub-filament 32 is spaced obliquely upward from the focal point f.

FIG. 4 is a diagram schematically showing a conventional example different from the above, and FIGS. 5 and 6 are views taken in the direction of arrow A.

Figure 5 is for right-hand traffic and corresponds to the previous figure 2.
Figure 6 is for left-hand traffic and corresponds to the previous figure 3.

In this example, the main filament 31 is aligned with the optical axis Z.
-Z, but the subfilament 32 is located obliquely above the focal point f, which is the same as in the prior art example.

In each of the conventional headlights shown in FIGS. 1 to 6, a seventh
A prism lens as shown in the figure is installed. This prism lens is composed of a combination of lattice-shaped prism elements, and in this example, the horizontal pitch Ph of the peripheral prism elements is 5 mm, and the vertical pitch Pv is 15 mm.

In the conventional headlamp configured as described above, for example, the light distribution pattern by the subfilament 32 of the bulb for right-hand traffic shown in FIG.
It will look like the figure. Irradiation by this subfilament is used when you cross paths with an oncoming vehicle, so it is necessary to illuminate your vehicle's lane (right side) and not dazzle the oncoming vehicle.

[The problem that the idea attempts to solve]

In the light distribution pattern shown in FIG. 8, the zone with the highest brightness is in the lower right, but a portion of the projected light beam extends far above the H-H line (horizontal line on the screen). For this reason, there is a problem that it tends to dazzle oncoming vehicles, and there is also a problem that visibility is poor because a cut line that cuts the driving lane diagonally does not appear.

In addition, headlights that use a light source bulb with a filament that extends along the optical axis (so-called C-8 type) create a cut line that cuts the oncoming lane diagonally, dazzling oncoming vehicles. Although it is difficult, there is a problem that the irradiation range of the hot zone is narrow and it feels dark.

The present invention improves the above-mentioned problems by using a C-6 type light source bulb (where the filament is perpendicular to the optical axis), which has a wide hot zone of the light distribution pattern caused by the light from the subfilament, and which has an oblique light distribution pattern. To provide a headlamp for an automobile that does not have a cut line that may dazzle oncoming vehicles.

[Means to solve the problem]

In order to achieve the above-mentioned purpose, this invention
A light source bulb equipped with a filament having a length substantially perpendicular to the optical axis is installed at a position where the sub-filament is spaced obliquely upward from the focal point of the reflector, and a lens is attached to the front opening of the reflector. In automobile headlights, the lens is divided into four equal parts by two orthogonal axes passing through the center of the lens.
Of the two quadrants, at least the area where the light directed upward from the oncoming lane where the subfilament is located is incident.
A tilted prism is formed that is tilted toward approximately the center of the lens, and the tilted prism is a prism that diffuses light emitted from the subfilament and reflected by the reflector in a direction perpendicular to the tilt axis of the tilted prism. Features.

[Effect]

As mentioned above, in the present invention, among the four quadrants divided into four equal parts by two orthogonal axes passing through the center of the lens, at least the subfilament is placed in the area where light directed upwards from the oncoming lane is incident, approximately at the center of the lens. A tilted prism is formed that tilts toward the direction, and the tilted prism is a prism that diffuses the light emitted from the subfilament and reflected by the reflector in a direction perpendicular to the tilt axis of the tilted prism. Light trying to extend upward can be directed diagonally forward and diagonally rearward, and a cut line can be formed by the light directed diagonally forward, and it can be prevented from dazzling oncoming vehicles.

〔Example〕

FIG. 9 is a diagram explaining the principle of the present invention, showing the light distribution on the screen surface when the light from the subfilament is reflected by a reflector and projected onto the screen.

As described above, the subfilament 32 has a length away from the focal point f and in a direction perpendicular to the optical axis. And each of the above examples (Fig. 2, Fig. 3, Fig. 5
As shown in Fig. 6), the subfilament 32
is installed horizontally. The image of such a subfilament is tilted to the left by about 20 degrees near point A on the screen surface. Similarly, near point ro, it is tilted to the left by about 20 degrees. Also, near point C,
Near point 2, each is tilted 5 degrees to the left. In this way, the inclination angle of the subfilament image changes at each point on the screen.

On this screen, by connecting points that produce the same angle of inclination, a group of curves is obtained. In this figure,
The numbers shown around the rectangular screen indicate the inclination of the subfilament image.

The present invention is based on the area surrounded by the above-mentioned curve group, where the light directed upward from the oncoming lane enters, that is, the four quadrants divided into four by two orthogonal axes passing through the center of the lens. For example, the inclination angle α in the quadrant in which at least the subfilament 32 is located
In the area surrounded by the curve of α = -5° and the curve of α = -15°, there is a tilt angle approximately toward the center of the lens.
A tilted prism 4 tilted at 10° is formed. In addition,
Although FIG. 10 shows an example in which the tilted prism 4 is also formed in the area below the lens where light directed upwards from the oncoming lane is incident, this is not necessarily required.

11 shows details of the tilted prism 4, FIG. 11A is a partial front view of the tilted prism, FIG. 11B is a sectional view taken along line B-B, and FIG. 11C
is also a CC sectional view. As shown in these figures, the tilted prism 4 is formed as a concave prism (or a convex prism) that diffuses incident light in a direction perpendicular to the tilt axis. The angle θ shown in FIG. 11C can be set arbitrarily.

FIG. 12 shows a light distribution pattern of a headlamp using a lens provided with the tilted prism 4 shown in FIGS. 10 and 11, and corresponds to FIG. 8 of the conventional example.

As is clear from comparing Figure 8 and Figure 12, the light that was shining above the H-H line of the oncoming lane (left side) in Figure 8 disappears, and the light is directed diagonally toward the oncoming lane (left side). A diagonal cut line 5 is formed by distributing light downward and diagonally above the H-H line of the driving lane (right side).

[Effect of idea]

In this way, the automobile headlamp according to the present invention is
The hot zone (100 mm in Fig.
Although the closed curve (shown by .

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an example of an automobile headlamp using a conventional C-6 type light source bulb, and Figure 2 is a cross-sectional view of an example of an automobile headlamp using a conventional C-6 type light source bulb.
The view is shown in the direction of arrow A in the figure, and the valve for right-hand traffic is drawn. FIG. 3 is a conventional example similar to FIG. 2, and depicts a valve for driving on the left side. Fig. 4 is an explanatory diagram schematically depicting a cross section of a conventional example different from the above, and Fig. 5
The figure is a view in the direction of arrow A in FIG.
The corresponding figure, FIG. 6, is also a figure corresponding to FIG. 3. FIG. 7 is a front view of a lens in an example of a conventional headlamp, and FIG. 8 is a diagram showing a light distribution pattern of a subfilament in the conventional example. Figure 9 is a diagram explaining the principle of the present invention.
FIG. 0 is a front view of a prism lens according to an embodiment of the present invention, FIG. 11 is a three-view diagram showing the structure of the prism lens, and FIG. 12 is a diagram showing a light distribution pattern in the embodiment.

Claims (1)

[Scope of utility model registration request] A light source bulb equipped with a filament having a length substantially perpendicular to the optical axis is installed at a position where the sub-filament is spaced obliquely upward from the focal point of the reflector, and a lens is attached to the front opening of the reflector. In automobile headlights,
Among the four quadrants divided into four by two orthogonal axes passing through the center of the lens, a tilted prism that is tilted approximately toward the center of the lens is placed in an area where light directed upward from the oncoming lane where at least a subfilament is incident is incident. A headlamp for an automobile, characterized in that the tilted prism is a prism that diffuses light emitted from the subfilament and reflected by the reflector in a direction perpendicular to the tilt axis of the tilted prism.