JP2516564Y2 - Variable light distribution vehicle headlight - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement of a vehicle headlamp, and in particular to a lamp which uses a single filament type bulb and is capable of changing the irradiation light beam pattern. The present invention relates to a light variable type vehicle headlamp.

[Conventional technology]

When driving a car at night or in a tunnel, lighting by a headlight is a light distribution pattern of a main beam that is focused on a central portion as shown in FIG. 17 (a) during general driving, and FIG. 17 (b) when passing each other. It is desirable to form a sub-beam light distribution pattern which is diffused below the horizontal line H as shown in FIG. 5A and is deflected slightly to the left to form scattered light above the horizontal line H.

However, since a lamp using a single filament type bulb that constitutes a headlight can obtain only one light distribution pattern for each lamp, it corresponds to general traveling (a) and passing (b). As a structure for obtaining a light distribution pattern, a structure in which the single filament bulb itself is moved has been conventionally used. However, in the structure in which the valve is displaced, there is a problem that the structure becomes complicated because a slight shift has a great influence on the light distribution. Therefore, generally, as shown in FIG. 18, a pair of lamps a and b having respective light distribution patterns are arranged in parallel,
This is switched and used, and the car design is 4
It had a problem that it was limited to the light type.

[Problems to be solved by the device]

The present invention was created in view of the above problems,
An object of the present invention is to provide a variable light distribution type vehicle headlamp having a novel structure in which a light distribution pattern of an irradiation light beam can be switched and deflected or gradually changed in a lamp using a single filament bulb as a light source. It is what

[Means for solving the problem]

In order to achieve the above object, a variable light distribution type vehicle headlamp according to the present invention is a vehicle headlamp in which a single filament type bulb forming a light source is fixedly provided in front of a reflector. A filament is formed so as to extend forward along the optical axis, and the reflecting surface of the reflector is
At the position where the substantially upper half is closer to the filament of the valve,
A cylindrical prism filter having a prism lens section formed on the outer periphery of the bulb is formed on a parabolic mirror surface or an elliptical reflecting mirror surface such that substantially the lower half of the bulb has a focal point at a position farther than the filament of the bulb. The gist of the present invention is that the cylindrical prism filter can be moved and displaced between a position retracted from the valve and a position externally inserted into the valve by pivotally arranging the cylindrical prism filter through the valve.

Further, it is preferable that the cylindrical prism filter has an inner wall surface parallel to the optical axis and has a prism lens cross section having a constant prism angle on the reflector side.

[Action]

According to the above configuration, since the bulb is a single filament type that extends forward along the optical axis, the light source position with respect to the reflector does not displace. However, when a tubular prism filter is externally attached to the bulb, the tubular primism filter The light beam that has passed through the cross section of the prism lens is refracted in a certain direction, so that it appears as if it were emitted from a light source at another position. Therefore, even if it is a single filament type bulb by moving and displacing the cylindrical prism filter to the position retracted from the bulb and the position extrapolated to the bulb by the displacement drive support mechanism, the main beam and the sub-beam are the same as the light source of the double filament bulb. The effect is to change the pattern of the irradiation light flux.

That is, when the cylindrical prism filter is displaced and supported at a position to be extrapolated to the valve, the irradiation light beam from the valve is irradiated through the prism cross section of the filter, and therefore the irradiation light beam from the valve is applied to the prism of the cylindrical prism filter. It is refracted in a certain direction by the lens cross section, apparently moves to another position, and acts as if radiated from a similar light source at the focal position of the upper half parabolic mirror surface. At this time, in the light distribution pattern by the reflector, the pattern from the upper half parabolic mirror surface is focused around the optical axis and overlaps with the center of the pattern from the lower half parabolic mirror surface below the horizontal line. So
The irradiation light pattern is diffused below the horizontal line and forms a “main beam” light distribution pattern in which bright portions are concentrated on the optical axis L and suitable for general traveling with good distance visibility.

Further, when the cylindrical prism filter is supported backward from the bulb position (displaced to the front position on the optical axis), the light flux emitted from the bulb is not affected by the filter. At this time, the light distribution pattern by the reflector is such that the pattern from the upper half parabolic mirror surface is inverted below the horizontal line and overlaps the pattern from the lower half parabolic mirror surface, so the irradiation light after passing through the front lens is The pattern is a "sub-beam" light distribution pattern that is suitable for crossing travel that cuts glare to oncoming vehicles that diffuses below the horizontal line and is deflected slightly to the left to form a light diffusing section above the horizontal line. Form.

〔Example〕

An embodiment of a light distribution variable type vehicle headlamp according to the present invention will be described below with reference to the drawings.

1 to 4 show a first embodiment of the present invention, in which a single filament type bulb 2 is placed through a bulb socket 3 so that a filament is positioned on an optical axis L of a reflector 1. In addition to being provided, the front surface of the reflector 1 is covered by the front lens 4. The reflector 1 has a dividing line P1 extending horizontally from the height of the optical axis L to the right side of the front surface and a dividing line P2 extending downwardly to the left side of the front surface and extending downwardly at about 15 °. The half part forms a parabolic mirror surface 1a having a focal point Fu at a position closer to the filament 2a of the bulb 2, and the lower half part forms a parabolic mirror surface 1b having a focal point Fd at a position farther from the filament 2a of the valve 2.

Further, 5 is a cylindrical prism filter carried on the optical axis L by the displacement driving support mechanism 6, the inner wall surface 5a of the cylindrical prism filter 5 is parallel to the optical axis L, and the prism angle is on the reflector 1 side. It is made of glass or heat-resistant transparent rigid resin that has a prism lens cross section with θ (= approximately 25 °), and the inner diameter φ (= approximately 20 mm) and tube length 1 (= approximately 25 mm) are in the valve 2. It has a size to be extrapolated.
The displacement driving mechanism 6 has a structure for displacing and supporting the cylindrical prism filter 5 between a position where the cylindrical prism filter 5 is completely inserted into the bulb 2 (arrow A) and a position on the front optical axis (arrow B) which is off the outer circumference of the bulb 2. If necessary, it also stably supports the intermediate position of AB, and can be implemented by various structures such as a link mechanism, a screw mechanism, and a cam mechanism.

In the variable light distribution type vehicle headlamp having the above-mentioned configuration, when the cylindrical prism filter 5 is supported backward at the position B, as shown in FIG. Therefore, the light distribution pattern by the reflector 1 (see FIG. 5b) is such that the pattern Pu from the upper half parabolic mirror surface 1a is inverted below the horizontal line H, and the lower half parabolic mirror surface is reflected.
Overlaps the pattern Pd from 1b. Therefore, the front lens 4
As shown in FIG. 5 (c), the irradiation light pattern after passing through is diffused below the horizontal line H and slightly deflected to the left to form a diffuser above the horizontal line H. A sub-beam light distribution pattern suitable for passing through is formed by cutting glare to a vehicle.

Next, when the cylindrical prism filter 5 is displaced and supported at the position A where it is extrapolated to the bulb 2, as shown in FIG. 6A, the luminous flux emitted from the bulb 2 passes through the prism cross section of the filter 5. Is irradiated. Therefore, as shown in FIG. 3, the luminous flux emitted from the bulb 2 is changed to the cylindrical prism filter 5
It is refracted in a certain direction by the prism lens cross section, and apparently at another position (in the case of the embodiment, about 5 mm on the optical axis L).
Move toward the reflector 1) and focus on the upper half parabolic mirror surface 1a
It works as if it was emitted from the similar light source S at the Fu position.
That is, the light distribution pattern by the reflector 1 (see FIG. 6b) is such that the pattern Pu from the upper half parabolic mirror surface 1a is focused around the optical axis L and the lower half portion below the horizontal line H is used. It overlaps the center of the pattern Pd from the parabolic mirror surface 1b. Therefore, the irradiation light pattern after passing through the outer lens 4 is
As shown in FIG. 6 (c), a light distribution pattern of a main beam that is diffused below the horizontal line H and has a bright portion concentrated on the optical axis L and is suitable for general traveling with good distance visibility is formed. To do.

In the filter 5 of the above embodiment, the numerical values of the prism angle θ, the inner diameter φ, and the tube length 1 are the refractive index τ of the used member, the parabolic mirror surfaces 1a and 1b, and the positional relationship with the filament 2a of the bulb 2. The design can be appropriately changed depending on the size of the valve 2 and the like.

Next, FIGS. 7 to 9 show a second embodiment of the present invention.

In the drawing, reference numeral 1 denotes a reflector having a parabolic reflecting mirror surface 1a having a focal point F on the optical axis L, and a filament 2 on the optical axis L of the reflector 1 approximately 5 mm ahead of the focal point F position.
The single filament bulb 2 is fixed via a valve socket 3 so that a is located. Further, the cylindrical prism filter 5 carried on the optical axis L by the displacement driving support mechanism 6 has a semi-cylindrical shade 7 continuous to the rear end.
Is integrally projecting from the lower half of the optical axis L, and the displacement driving mechanism 6 completely inserts the cylindrical prism filter 5 into the valve 2 and at the same time removes the shade 7 from the position of the valve 2. (Arrow A), the filter 5 is removed from the outer circumference of the bulb 2, and at the same time, the shade 7 is displaced and supported at the front optical axis position (arrow B) opposite the bulb 2 position.

In the variable light distribution type vehicle headlamp having the above-described configuration, when the cylindrical prism filter 5 is supported backward at the B position, as shown in FIG. Is not affected, the light source is not at the focal point F of the parabolic mirror surface 1a, so that it becomes a diffused light flux, and since the light flux in the lower half portion is cut by the shade 7, the light distribution pattern P by the reflector 1 is shown in FIG. As shown in b), the light beam is inverted below the horizontal line H to form a sub-beam light distribution pattern that is suitable for crossing travel by cutting glare to an oncoming vehicle.

Next, when the cylindrical prism filter 5 is displaced and supported at the position A for extrapolation to the bulb 2, as shown in FIG. 11 (a), the irradiation light flux from the bulb 2 passes through the prism cross section of the filter 5. Since it is irradiated, the irradiation light beam acts as if it was emitted from the similar light source S at the focal point F position of the parabolic mirror surface 1a,
As shown in FIG. 11 (b), the light distribution pattern P by the reflector 1 is focused around the optical axis L to form a light distribution pattern of a main beam suitable for general traveling with good distance visibility.

Further, FIGS. 12 to 14 show a third embodiment of the present invention which uses a reflector having a complex reflecting mirror surface.

This embodiment is the same as the first embodiment except that the reflecting mirror surface of the reflector 1 extends horizontally from the height position of the optical axis L to the front right side and the dividing line P1 extends downwardly to the front left side by about 15 °. Line P2 and dividing line P3 extending vertically downward from the optical axis L
The upper half parabolic mirror surface 1a, the lower half right elliptical parabolic mirror surface 1c and the lower half left elliptical parabolic mirror surface 1d into three sections, and the filament 2a of the bulb 2 is positioned on the reflector 1 side. Focus F1 of parabolic mirror surface 1a, focus of lower half right elliptical parabolic mirror surface 1c and lower half left elliptical parabolic mirror surface 1d on the outer lens 4 side
It is composed of F2 and F3. Further, the cylindrical prism filter 5 carried on the optical axis L by the displacement driving support mechanism 6 is provided.

In the variable light distribution type vehicle headlamp having the above-described configuration, when the cylindrical prism filter 5 is supported backward at the position B, as shown in FIG. As shown in FIG. 15 (b), the pattern P1 from the upper half parabolic mirror surface 1a is inverted below the horizontal line H, and the lower half right ellipse is not affected. Since the parabolic mirror surface 1c and the lower half left elliptical parabolic mirror surface 1d overlap on the patterns P2 and P3, they diffuse below the horizontal line H, and are polarized slightly to the left and above the horizontal line H. A light distribution pattern of a sub-beam that is suitable for crossing traveling is formed by forming a light diffusing portion to cut glare to an oncoming vehicle.

Next, when the cylindrical prism filter 5 is displaced and supported at the position A for extrapolation to the bulb 2, as shown in FIG. 16 (a), the irradiation light flux from the bulb 2 passes through the prism cross section of the filter 5. It is irradiated and acts as if it was emitted from the similar light source S located at the focal point F1 position of the upper half parabolic mirror surface 1a. That is, as shown in FIG. 6 (b), the light distribution pattern by the reflector 1 is such that the pattern P1 from the upper half parabolic mirror surface 1a is focused around the optical axis L and below the horizontal line H. The lower half right elliptical parabolic mirror surface 1c and the lower half left elliptical parabolic mirror surface 1d are overlapped on the centers of the patterns P2 and P3, diffuse below the horizontal line H, and shine on the optical axis L. A light distribution pattern of a main beam is formed which is suitable for general running in which the parts are concentrated and which has good distant visibility.

[Effect of device]

Since the variable light distribution type vehicle headlamp according to the present invention is constructed as described above, the light source is rotated by the optical axis when the light source is inserted by retracting the cylindrical prism filter to the single filament bulb of the light source. It is possible to form a similar light source as if it moved in the same direction, and it is possible to change the light distribution pattern of the headlight between the main beam and the sub beam by operating the double filament bulb.

Further, according to the present invention, by controlling and holding the displacement driving support mechanism for driving the displacement of the cylindrical prism filter at the intermediate position, not only the switching of the light distribution pattern but also the gradual change control can be performed. Yes, the practical effect after implementing the present invention is extremely large.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic vertical sectional view of a lamp fixture showing a first embodiment of a variable light distribution type vehicle headlight according to the present invention, and FIG. 2 is a front view of the same reflector, 3 is an enlarged sectional view of the filament portion, FIG. 4 is a perspective view of a cylindrical prism filter, and FIGS. 5 and 6 are explanatory views showing the forming action of the sub beam and the main beam in the first embodiment. FIG. 7 is a schematic vertical sectional view of a lamp according to a second embodiment of the present invention, FIG. 8 is an enlarged sectional view of the filament portion, FIG. 9 is a perspective view of a cylindrical prism filter and a shade, FIG. FIG. 11 is an explanatory view showing a forming action of a sub beam and a main beam in the second embodiment, FIG. 12 is a schematic vertical sectional view of a lamp according to the second embodiment, and FIG. 13 is a front view of the same reflector. FIG. 14 is an enlarged cross-sectional view of the filament portion, and FIGS. 15 and 16 are the third embodiment of the present invention. Explanatory view showing the formation effect of the sub-beams and the main beam in the example, FIG. 17 is an explanatory view showing a preferred light distribution pattern when an automobile runs, FIG. 18 is a perspective view showing a four-lamp type automobile headlamp. 1 …… Reflector 1a …… Upper half parabolic mirror surface 1b …… Lower half parabolic mirror surface 1c …… Lower half right elliptical parabolic mirror surface 1d …… Lower left elliptical parabolic mirror surface 2 …… Single filament bulb 2a …… Filament, 4 …… Outer lens 5 …… Cylindrical prism filter 6 …… Displacement drive support mechanism, 7 …… Shade F, Fu, Fd, F1, F2, F3 …… Focus

Claims (2)

(57) [Scope of utility model registration request] 1. A vehicle headlamp in which a single filament type bulb constituting a light source is fixed in front of a reflector, wherein a filament of the bulb is formed so as to extend forward along an optical axis. The reflecting surface is formed such that the upper half portion has a focal point at a position closer to the bulb filament, and the substantially lower half portion has a focal point at a position farther than the bulb filament, and a prism lens cross section is provided on the outer periphery of the bulb. A cylindrical prism filter is rotatably and pivotally mounted via a displacement drive support mechanism so that the cylindrical prism filter can be moved and displaced between a position retracted from the valve and a position externally inserted into the valve. A variable light distribution headlight for vehicles. 2. The cylindrical prism filter is characterized in that an inner wall surface thereof is parallel to an optical axis and a prism lens section having a constant prism angle is formed on the reflector side. Variable light distribution vehicle headlamp.