JPH076562Y2 - Car headlamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a headlamp using a discharge bulb, and in particular, by sliding a shade for forming a sub-beam, light emitted from a discharge part, which is a light emission source, toward a reflector. The present invention relates to a headlamp for an automobile equipped with a discharge bulb, in which both a main beam and a sub beam can be formed by cutting a part of the above.

[Problems to be Solved by Prior Art and Invention]

As a conventional automobile headlamp, a bulb-type bulb is generally used. For example, an H ₄ bulb in which two filaments are arranged in parallel in the optical axis direction in a glass sphere, A main beam and a sub-beam are formed by switching the power supply to each filament.

However, since the filament, which is a light emitting source, and the filament supporting portion are heated to a high temperature, the filament may be broken due to long-term use, and there is a problem in durability. In addition, conventional bulbs use electric energy to heat a filament to emit light and utilize the light emitted by this filament. Most of the electric energy is radiated as heat energy, and only part of the heat energy is converted to light energy. Therefore, there is a problem that the energy efficiency is very poor and the power consumption is accordingly increased.

In view of the above-mentioned problems of the prior art, the discharge bulb of the type that emits light by the discharge between the electrodes has no problem of disconnection like the type that emits the filament described above, and the power consumption is higher than that of the filament type. Because of its small size and large light intensity, discharge bulbs have recently been receiving attention as headlamp bulbs. However, there is a problem in that two light emitting parts of the discharge bulb cannot be provided like the filament of the H ₄ type bulb, and one discharge bulb cannot form two different light distributions of the main beam and the sub beam.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to use a discharge bulb as a bulb of a headlamp for a vehicle and to use a single discharge bulb to provide two light distributions for a main beam and a sub beam. To provide a headlamp.

[Means for Solving the Problems]

The inventor reflects the light from the discharge part on the entire reflective parabolic surface to form the main light distribution, and the shade arranged below the discharge part allows the light directed from the discharge part to approximately the lower half of the reflected parabolic surface. As a result of examining the positional relationship between the single reflection parabola and the discharge part of the discharge bulb by cutting and forming the sub-light distribution by the reflected light in the almost half area of the reflection parabola, I found something like this.

As shown in FIG. 20 (a), when the reflector and the discharge bulb are arranged such that the focal point f of the reflective paraboloid 3 is located between the rear end 5a of the discharge part 5 and the center 5b ( In the following, this is referred to as the first case), the reflected light on the reflective parabolic surface 3 becomes substantially parallel light, and as shown in FIG.
The main beam has the largest amount of light in the central portion 8 and has the most desirable light distribution pattern as the main beam. However, as shown in FIG. 22 (a), the sub-beam has the same diameter as the main beam, and the cut-off line is unclear because of the high illuminance in the central portion. The light distribution pattern of this sub-beam has a smaller degree of outward spread than the desired light distribution pattern as the sub-beam. Reference numeral 7 is a shade for forming a sub beam.

Next, as shown in FIG. 20 (b), the reflector and the discharge bulb are arranged such that the focal point f of the reflection paraboloid 3 is at the rear end of the discharge part 5.
When it is arranged so as to be located at 5a (hereinafter referred to as the second case), the reflected light on the reflective parabolic surface 3 does not become parallel light but becomes cross light distribution, and FIG. As shown in b), the beam range of the main beam was larger than that in the first case, and the light distribution pattern was such that the light amount in the central portion of the main beam was slightly insufficient. And the sub beam is
As shown in Fig. 22 (b), the diameter is the same as the main light distribution,
It became a substantially desirable light distribution pattern for a sub-beam with a clear cut-off line.

Further, as shown in FIG. 20 (c), the reflector f and the discharge bulb are arranged such that the focal point f of the reflection paraboloid 3 is at the rear end of the discharge part 5.
When it is located slightly behind 5a (hereinafter referred to as the third case), all the reflected light on the reflective parabolic surface 3 becomes a cross distribution, as shown in FIG. 21 (c). In addition, the main beam is larger than the second case in the light distribution area, and the shadow 9 is formed in the central portion, so that the light distribution pattern becomes insufficient as the main beam in the central portion. Further, as shown in FIG. 22 (c), the sub-beam has the same diameter as the main beam, a large light distribution area, and the most desirable light distribution pattern as a sub-beam in which the cut-off line clearly appears.

The desired light distribution pattern for the main beam is
In FIG. 21 (a) or (b), the best light distribution pattern is FIG. 21 (a). On the other hand, the most desirable light distribution pattern for the sub beam is shown in FIG. 22 (c).

Therefore, in order to achieve the above-mentioned object, the inventor has decided that the light distribution pattern of the main beam should be as shown in FIG. 21 (a) or (b) and the light distribution pattern of the sub-beam as shown in FIG. 22 (c). Since it suffices to form the reflective paraboloid of the reflector, we decided to adopt the following means.

That is, in the automobile headlamp according to claim (1), the parabolic reflector formed in the lamp body and the discharge part that is the light emitting source are arranged so as to be in the vicinity of the focal point of the reflector. Discharge valve,
A shade member is provided in front of the reflector so as to be slidable in the optical axis direction, and a shade member for blocking a part of light traveling from the discharge portion of the discharge bulb toward the reflector to form a sub-beam.

And in Claim (2), a reflector is formed from the upper reflection paraboloid for sub-main beams and the lower reflection paraboloid for main beams which have the same focal length, and the said upper reflection paraboloid is a discharge part. A reflection paraboloid whose focal point is located slightly rearward of the rear end, and the lower reflection parabolic surface is translated in parallel with the reflection parabolic surface forward in the optical axis direction. This is a reflective parabolic surface with the focal point located between.

Further, in claim (3), the reflector is formed from an upper reflection parabola for the sub & main beam and a lower reflection parabola for the main beam having a focal length shorter than the focal length of the upper reflection parabola. The upper reflective parabolic surface is a reflective parabolic surface whose focal point is located slightly rearward of the rear end of the discharge part, and the lower reflective parabolic surface is parallel to the reflective parabolic surface forward of the optical axis. It is moved so as to form a reflective parabolic surface with a focal point located between the rear end and the center of the discharge part.

[Action]

In claim (1), the discharge bulb has a structure that emits light by the discharge between the electrodes, and there is no risk of disconnection. Further, since the electrons are directly converted into light energy, the efficiency of energy conversion from electric energy to light energy is high, and therefore power consumption is low. When the shade member is slid in the optical axis direction and the shade member does not block the light traveling from the discharge part to the reflector, the reflected light from the entire reflector forms the main beam, and the shade member travels from the discharge part to the reflector. When a part of the light is blocked, the light not reflected by the shade member is reflected by the reflector to form a sub beam.

In Claims (2) and (3), the focal point of the reflective parabolic surface for forming the sub & main beam is located slightly rearward of the rear end of the discharge part, and the reflected light on the reflective parabolic surface becomes cross light distribution. The light distribution pattern is the most desirable as a sub beam. As for the main beam, in claim (2), the focal point of the reflective parabolic surface for forming the main beam is located between the rear end of the discharge part and the center, and the reflected light on the reflective parabolic surface is parallel light or substantially parallel light. It becomes a light close to a flat light and has a light distribution pattern which is desirable as a main beam. Further, as a main beam, claim (3)
Then, the focal point of the reflection paraboloid for forming the main beam is located between the rear end and the center of the discharge part, and the reflection paraboloid for forming the main beam has a smaller focal length than the reflection paraboloid for forming the sub-beam. Therefore, the irradiation area above the horizontal level of the main beam is expanded outward to form a light distribution pattern that is substantially circular.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

1 to 6 show a headlamp showing an embodiment of the present invention. FIG. 1 is a perspective view of the headlamp with a lens removed, and FIG. 2 is a vertical sectional view of the headlamp.
FIG. 3 is a front view showing a reflective paraboloid of the reflector, and FIG.
Figures (a) and (b) are diagrams showing an example of the arrangement of a reflective parabolic surface and a discharge part, respectively, and Figure 5 is a sub-beam light distribution pattern in the reflector shape shown in Figures 4 (a) and (b). 6 (a) and 6 (b) are shown in FIG. 4 (a),
It is a figure which shows the light distribution pattern of the main beam in the reflector shape shown to (b).

In these drawings, reference numeral 10 is a container-shaped lamp body having a front opening, and a parabolic reflector 12 which is aluminum vapor-deposited is formed on the inner peripheral surface thereof. A bulb insertion hole 14 is formed in the rear top portion of the reflector 12, and a discharge bulb 20 that emits light due to discharge between the electrodes is inserted therein. Reference numeral 21 indicates a discharging unit. Reflector 12
Upper reflective parabolic surface 12A for forming the sub and main beams, with the vertical center position where the valve insertion hole 14 is formed as a boundary
And a lower reflection parabolic surface 12B for forming the main beam.

The focal lengths of both reflective paraboloids 12A and 12B are the same, and the focal position of the upper reflective paraboloid 12A is shown in FIG.
(B) As indicated by reference numeral P ₁ , it is located at a position slightly separated from the discharge part 21 rearward. On the other hand, the focal position of the lower reflective parabolic surface 12B is located between the rear end and the center of the discharge part 21, and is located at the rear end position P ₂ of the discharge part 21 in FIG. 4 (a). 4 (b), it is located at a substantially intermediate position P ₃ between the rear end of the discharge part 21 and the center 21a. That is, the lower reflective paraboloid
12B ₁ and 12B ₂ are parabolic surfaces (indicated by reference numeral 12C) that are continuous with the upper reflective parabolic surface 12A, and are parallel translated by d ₁ and d ₂ forward in the optical axis 1 direction. A step 13 corresponding to the parallel movement distances d ₁ and d ₂ is formed between 12A and 12B. Then, the light from the discharge part 21 of the bulb 20 is reflected by the reflective parabolic surfaces 12A and 12B of the reflector to form a main beam and a sub beam. And the main beam is a parabolic surface with both reflections 12A, 12
Although formed by the reflected light at B, the sub-beam is formed only by the reflected light at the upper reflective parabolic surface 12A because the light traveling from the discharge part 21 to the reflector is partially cut by the shade member 30 described later.

Reference numeral 30 is a shade member that swings in the front-rear direction of the optical axis and blocks light traveling from the discharge portion 21 toward the lower reflection parabolic surface 12B of the reflector. The shade member 30 includes a semi-cylindrical shade main body 32 that blocks light, a parallel link 34 that is a leg portion that swings and displaces the shade main body 32, and a drive mechanism 36 that swings the link 34. There is. A bracket 33 is vertically provided on a lower side surface of the shade main body 32 that opens upward, and a parallel link 34 (a main link 34a and a sub link 34b) is pin-connected to the bracket 33. The parallel links 34 are respectively supported by the casing 37 of the drive mechanism 36. The drive mechanism 36 includes a slider 38 mounted in the casing 37 so as to be slidable in the front-rear direction in parallel with the optical axis l.
And an electromagnetic valve that slides this slider 38
39, and the crank-shaped bearing shaft 35 of the main link 34a.
Is pin-connected to the slider 38. By controlling the energization of the electromagnetic valve 39 on and off, the shade body 32 swings around the fulcrum 35a integrally with the parallel link 34, and covers the lower portion of the valve discharge portion 21 at the rear position (shown by the solid line in FIG. 2). ) And the front position (shown by the phantom line in FIG. 2) where the lower part of the bulb discharge portion 21 is opened can be taken alternatively. Reference numeral 38a is a return spring. Then, when the shade body 32 reaches the front position shown by the phantom line in FIG. 2, the light traveling from the discharge part 21 to the reflective paraboloids 12A, 12B is not blocked by the shade body 32, and is reflected by both reflective paraboloids 12A, 12B. A main beam is formed by the reflected light. On the other hand, when the shade body 32 reaches the rear position shown by the solid line in FIG.
Light directed from the lower reflection parabolic surface 12B to the lower reflection parabolic surface 12B is cut by the shade body 32, and only the upper reflection parabolic surface 12A is illuminated. Then, the sub-beam is formed by the reflected light on the upper reflection parabolic surface 12A.

Next, the light distribution patterns of the main beam and the sub beam formed by the lamp of this embodiment will be described with reference to FIGS.

First, the case where the reflective paraboloids 12A and 12B have the shape shown in FIG. Regarding the sub-beam, the focal position of the upper reflective parabolic surface 12A is slightly rearward (symbol P
₍ See FIG. ₁ ), the sub-beam light distribution pattern in the reflector shape shown in FIG.
As shown in FIG. 5C), the reflected light on the upper reflective parabolic surface 12A largely crosses the optical axis l, and the most desirable light distribution pattern as a sub beam is obtained as shown in FIG. On the other hand, with respect to the main beam, since the focus of the lower reflection parabolic surface 12B ₁ is located at the rear end of the discharge part (see reference numeral P ₂ ), the light reflected by this lower reflection parabolic surface 12B ₁ is shown in FIG. (B)
Similar to the reflected light in the reflector shape shown in,
The light distribution pattern of the main beam formed by the lower reflective parabolic surface 12B ₁ is a semicircular light distribution pattern in the upper half of the light distribution pattern shown in FIG. 21 (b) (see FIG. 6 (a )
Refer to code MB ₁ ). Further light reflection at the upper paraboloidal reflecting surface 12A from forming a light distribution pattern shown in FIG. 5 (FIG. 6 (a) reference numeral MB _2), the both patterns MB _1, MB ₂ were synthesized It becomes the pattern shape shown in FIG. This 6th
The pattern shape of the main beam shown in FIG.
Compared to the best light distribution pattern for the main beam shown in Fig. 21 (a), it spreads considerably outside below the horizontal position, and spreads slightly outside above the horizontal position, but it can be used. The main light distribution conditions are almost satisfied.

When the reflective paraboloids 12A and 12B have the shape shown in FIG. 4 (b), the sub-beams have exactly the same light distribution pattern as shown in FIG. On the other hand, with respect to the main beam, since the focus of the lower reflection parabolic surface 12B ₂ is located between the rear end and the middle of the discharge part (see reference numeral P ₃ ), the lower reflection parabolic surface 12B ₂ The reflected light is the same as the reflected light in the reflector shape shown in FIG. 20 (a), and the light distribution pattern formed by the lower reflection parabolic surface 12B ₂ is the light distribution pattern shown in FIG. 21 (a). It becomes a semicircular light distribution pattern of the upper half (see MB _{3 in} Fig. 6 (b)). Furthermore, the upper reflective parabolic surface 12A
The reflected light at the shape shown in Fig. 5 (see MB _{2 in} Fig. 6)
Therefore, both patterns MB ₃ and MB ₂ are combined into the 6th pattern.
The pattern shape shown in FIG. This FIG. 6 (b)
The pattern shape of the main beam shown in Fig. 21 differs from the best light distribution pattern for the main beam shown in Fig. 21 (a) in that it spreads considerably outside below the horizontal position. Satisfies the conditions of possible main light distribution.

7 and 8 relate to the improvement of the reflector shape shown in FIG. 4, and FIGS. 7 (a) and 7 (b) are views showing the vertical cross-sectional shape of the reflector, and FIG. 8 (a). ，
7B is a diagram showing a light distribution pattern of a main beam formed by the reflector shown in FIGS. 7A and 7B.

In FIGS. 4 (a) and 4 (b) described above, the reflective paraboloids 12A, 12
While B was the same focal length, both paraboloidal reflecting surface 12A in this embodiment, made different focal length of 12B, release respective upper reflective focal length of the lower paraboloidal reflecting surface 12B (12B _3, 12B ₄₎ It is smaller than the focal length of the object surface 12A. The virtual lines in FIGS. 7 (a) and 7 (b) are displayed to explain that the focal lengths are different from each other.
12B ₁ and 12B ₂ are lower reflection paraboloids (reflection paraboloids having the same focal length as the upper reflection paraboloid 12A). Others are the same as the reflector shape shown in FIGS. 4 (a) and 4 (b), and the description thereof will be omitted by giving the same reference numerals.

The main beam distribution pattern is the lower reflective parabolic surface.
Since the focal lengths of 12B ₃ and 12B ₄ are shorter than the focal length of the upper reflective parabolic surface 12A, as shown in FIGS. 8 (a) and 8 (b), the light distribution pattern above the horizontal position is outward. The light distribution pattern spreads and approaches the size of the irradiation area below. Virtual lines in FIGS. 8 (a) and 8 (b) indicate light distribution pattern outer peripheral positions (FIG. 6 (a), in the case of the reflector shape shown in FIGS. 4 (a) and 4 (b)).
(See (b)), and the irradiation range is expanded by an area outside the provisional line. This FIG. 8 (a),
The light distribution pattern of the main beam shown in (b) is also different from the best light distribution pattern shown in FIG. 21 (a), but substantially satisfies the conditions of usable main light distribution. The sub-beam is exactly the same as the light distribution pattern shown in FIG.

9 to 13 show another embodiment of the reflector shape. FIG. 9 is a front view showing a reflective paraboloid of the reflector, and FIGS. 10 and 11 are vertical cross-sectional shapes of the reflector. FIG. 10 is a sectional view taken along line XX and line XI-XI in FIG. 9 respectively. 12 and 13 are diagrams showing the light distribution patterns of the sub beam and the main beam having the reflector shape shown in FIG.

In these figures, the reflective paraboloid of the reflector is the upper reflective paraboloid 12 for the sub and main beams of the same focal length.
It is formed of A ₁ and a lower reflective parabolic surface 12B ₅ for the main beam. The upper reflection parabolic surface 12A ₁ has a shape narrowed in the left-right direction (shape with a shortened left-right direction) without changing the focal length of the upper reflection parabolic surface 12A shown in FIG. It is P ₁ . On the other hand, the lower reflective parabolic surface 12B ₅ has the reference numeral 12B ₆
The shape is extended to the area outside the upper reflection parabolic surface 12A _{1 in} the left-right direction (reflection parabolic surface), and a step 13 is formed between the upper reflection parabolic surface 12A ₁ and the lower reflection parabolic surface 12B _5. Are formed.
A front lens for distributing light in a predetermined direction is arranged in front of the reflector, and the front lens of the front lens facing the reflection paraboloids 12B ₆ formed on the left and right of the upper reflection paraboloid 12A ₁ is arranged. A prism step 16 for refracting the transmitted light upward is formed on the back surface. And this upper reflective paraboloid
The light distribution pattern of the sub-beam by 12A ₁ is shown in FIG. 12, and is slightly larger than the best light distribution pattern as the sub-beam shown in FIG. 22 (c) (shown by the phantom line in FIG. 12). Although it becomes smaller and the amount of light also decreases, it satisfies the sub light distribution conditions that can be used. The light distribution pattern of the main beam is shown in FIG. 13, and the maximum light amount position of the main beam is formed by forming the reflective parabolic surface 12B ₆ and the prism step 16 of the front lens (see reference numeral 18 in FIG. 13). The light quantity of the upper half irradiation area of the light distribution pattern is increased as the light is slid upward. In Fig. 13, a ribbon-shaped area appears in the center of the light distribution pattern.
18 is a light distribution pattern formed by light reflected by the reflecting parabolic 12B _6, is formed slightly above the position of the center portion position of the light distribution pattern of the whole main beam by the prism step 16.

In the reflector shapes shown in FIGS. 4 (a) and (b), and FIGS. 7 (a) and (b), the highest position of the light amount of the main beam is located slightly below the horizontal position, In the example, the lower reflective parabolic surface 12B ₅ is extended to the left and right sides of the upper reflective parabolic surface 12A ₁ , and the prism step 16 of the front lens increases the condensing density of the reflected light to the horizontal position. In this way, the highest light amount point is slid upward.

14 and 15 show another embodiment of the reflector shape, FIG. 14 is a front view showing a reflective paraboloid of the reflector, and FIG. 15 is a line XV-XV shown in FIG. FIG.

In the embodiment shown in FIG. 9, the prismatic step 16 of the front lens directs the light reflected by the reflective parabolic surface 12B ₆ upward, but in this embodiment, the upper reflective parabolic surface 12A is reflected.
The reflected light is directed upward by forming reflective parabolic surfaces 12B ₇ shown in FIG. 9 with the reflective parabolic surfaces 12B ₆ slightly upward on both sides in the left-right direction. That is, a reflective paraboloid
12B ₇ is a horizontal axis paraboloidal reflecting surface 12B ₆ shown in FIG. 9 (FIG. 15 the plane perpendicular to the axis) upwardly small amount ₁ around (e.g. 1
It has a slanted shape.
The light distribution patterns of the sub beam and main beam shown in Fig. 13 and Fig. 13 can be obtained.

FIG. 16 is a perspective view of the shade main body of the shade member used in the reflector shown in FIGS. 9 and 14. The front end side of the shade main body 42 has a cylindrical shape, and this cylindrical portion 43 is a parabolic surface 12B ₆ , 12 reflected from the discharge portion.
The light directed to B ₇ is cut off so that only the reflected parabolic surface 12A ₁ for forming the sub-beam is exposed to the light.

FIG. 17 shows still another embodiment of the shade body. When the discharge bulb 20 is used as the light source of the headlamp, a region where the luminous intensity is higher than the reference value as compared with the reference light distribution pattern is formed, and the luminous intensity of the region where the luminous intensity is too high is added to the reference value. In order to obtain an appropriate luminous intensity, a projection 45 having a predetermined shape is formed on the edge portion of the shade main body 44 on the side of the reflector, and a part of the light is eclipsed by the projection 45 so that the luminous intensity distribution of the light distribution pattern becomes appropriate. It was done.

In the embodiment described above, the shade member is moved in the optical axis direction by the electromagnetic valve and the link mechanism, but as shown in FIG. 18, the slide unit 52 assembled to the ball screw 50 is used. The shade main body 32 may be supported, and the drive motor 54 may rotate the ball screw 50 to slide the shade main body 32 integrally with the slide unit 52.

Further, as shown in FIG. 19, a shade member sliding structure including a permanent magnet and an electromagnet may be used. That is, a shade body (not shown) is supported by a slide member 62 made of a permanent magnet housed in the casing 60 slidably in the optical axis direction, and a coil 64 is wound around one side of the casing 60. An electromagnet 65 is configured. The shade body can be slid together with the slide member 62 by switching the energization direction to the coil 64.

[Effect of device]

As is clear from the above description, according to the headlamp of the present invention, since the discharge bulb used as the light source has no risk of disconnection, it is possible to obtain an automobile headlamp that does not require bulb replacement for a long period of time. Also, since the discharge bulb has a high conversion efficiency from electric energy to light energy,
It consumes less power. Further, by sliding the shade member in the optical axis direction and changing its position, it is possible to obtain light distribution of both the sub beam and the main beam.

[Brief description of drawings]

FIG. 1 is a perspective view of a headlamp according to an embodiment of the present invention with a lens removed, FIG. 2 is a vertical sectional view of the headlamp, and FIG. 3 is a front view showing a reflective parabolic surface of a reflector. 4 (a) and 4 (b) are views showing an example of the arrangement of the reflective paraboloid and the discharge part, and FIG. 5 is shown in FIG. 4 (a),
The figure which shows the light distribution pattern of the sub beam in the reflector shape shown to (b), and FIG.6 (a), (b) shows the light distribution pattern of the main beam in the reflector shape shown to FIG.4 (a), (b). Figure, Figure 7 (a), (b)
Is a view showing a vertical cross-sectional shape of a reflector which is an essential part of another embodiment of the present invention, and FIGS. 8 (a) and 8 (b) are main beams in the reflector shape shown in FIGS. 7 (a) and 7 (b). FIG. 9 is a plan view showing a reflective parabolic surface of a reflector, which is a main part of another embodiment of the present invention, and FIGS. 10 and 11 are vertical cross-sectional shapes of the reflector. FIG. 12 is a cross-sectional view taken along line XX and line XI-XI shown in FIG. 9, and FIGS. 12 and 13 are views showing light distribution patterns of the sub beam and the main beam by the same reflector.
FIG. 14 is a front view showing a reflective parabolic surface of a reflector which is an essential part of another embodiment of the present invention, and FIG. 15 is a line XV- shown in FIG.
FIG. 16 is a sectional view taken along the line XV, FIG. 16 is a perspective view of a main part of a shade member used in the reflector shown in FIGS. 9 and 14,
FIG. 17 is a perspective view of a main part of still another embodiment of the shade member, FIGS. 18 and 19 are views showing another embodiment of the shade member sliding mechanism, and FIGS. 20 (a) to 20 (c). Are diagrams showing the positional relationship between the reflector and the light emitting portion of the discharge bulb, and FIGS. 21 (a) to 21 (c) are FIGS. 20 (a) to 20 (c).
22A to 22C are diagrams showing the light distribution pattern of the main beam in each case shown in FIGS.
It is a figure which shows the light distribution pattern of the sub beam in each case shown to (c). 10 …… Lamp body, 12 …… Reflector, 20 …… Discharge bulb, 21 …… Discharge part, 30 …… Shade member, 32 …… Shade body, 12A …… Upper reflection parabola, 12B …… Lower reflection Parabolic surface, P ₁ ... Focus position of upper reflective parabolic surface, P ₂ , P ₃ ...
The focal position of the lower reflective paraboloid.

Claims (3)

[Scope of utility model registration request] 1. A parabolic reflector formed in a lamp body, a discharge bulb in which a discharge part, which is a light emitting source, is arranged near a focal point of the reflector, and a light in front of the reflector. A headlamp for an automobile, comprising: a shade member that is slidable in the axial direction and that shields a part of light traveling from a discharge part of the discharge bulb toward a reflector to form a sub beam. 2. The reflector is formed of an upper reflective parabolic surface for the sub and main beam and a lower reflective parabolic surface for the main beam, which have the same focal length, and the upper reflective parabolic surface is located behind the discharge part. It is a reflective parabolic surface whose focal point is located slightly rearward from the end, and the lower reflective parabolic surface is a parallel translation of the parabolic surface forward in the optical axis direction so that it is between the rear end and the center of the discharge part. The automobile headlamp according to claim 1, wherein the headlamp is a reflective paraboloid having a focal point located on the reflection parabolic surface. 3. The reflector is formed of an upper reflection parabolic surface for the sub & main beam, and a lower reflection parabolic surface for the main beam having a focal length shorter than the focal length of the upper reflection parabolic surface. The upper reflective parabolic surface is a reflective parabolic surface whose focus is located slightly rearward of the rear end of the discharge part, and the lower reflective parabolic surface translates the parabolic surface forward in the optical axis direction. The headlamp for a vehicle according to claim (1), characterized in that it is a reflective paraboloid whose focal point is located between the rear end and the center of the discharge part.