JP3261847B2 - Projector-type headlights that prevent color development - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector, a light source bulb disposed near the focal point of the reflector, and a light beam emitted from the light source bulb and reflected by the reflector, and is condensed and projected to the front of a lamp. The present invention relates to a projector-type headlamp having a convex lens and, more particularly, to a projector-type headlamp that prevents color unevenness when an HID bulb is used as a light source.

[0002]

2. Description of the Related Art Recently, a projector-type headlamp of this type has been rapidly spreading because of its small size and high luminous flux density. As a recent technology relating to the projector type headlight, for example, a technology described in Japanese Utility Model Laid-Open No. 2-47705 (Japanese Utility Model Application No. 5-1404) is known. 2A and 2B are views for explaining a known technique relating to a projector type headlamp, in which FIG. 2A is a schematic side view, and FIG. 2B is a diagram illustrating a group of iso-illuminance curves when a screen is irradiated. It is a chart. (A) As shown in the figure, a reflector having two focal points F1 and F2 (for example, a spheroidal mirror)
The light source bulb 2 is disposed at one first focal point F1. The light beam emitted from the light source bulb 2 and reflected by the reflector 1 is once focused on the second focal point F2, then enters the converging convex lens 3 as a diffused light beam, and becomes a substantially parallel light beam in front of the lamp. It is projected toward. In the vicinity of the second focal point F2,
A shade 4 for forming a light distribution pattern is provided. Part of the light beam passing near the second focal point F2 is blocked by the shade 4. In the figure showing the light distribution pattern (B), the shaded portions are the shadows generated by the shade 4 that are vertically and horizontally inverted and projected, and the outline of the shade of the shade is called a cut line. . The light distribution pattern shown in FIG. 13B is a table for theoretical explanation, but if it has such a tendency, the light distribution pattern for the own lane (to the left of the line V-V) can be obtained. Illuminates the front of the road surface, and does not illuminate the oncoming traffic lane (on the right side of the line V-V) above the horizontal line (line HH). It is suitable as a lamp.

[0003]

When an HID bulb is used as a light source of a projector-type headlamp, there is an advantage that a small bulb and a large amount of light are used, but there is a problem that color unevenness occurs. FIG. 3 is a longitudinal sectional view of a main part of the HID bulb, schematically showing the configuration of discharge arc light. Along the shortest path connecting the pair of discharge electrodes, a zone a, which is a light emitting portion composed of a central arc, is formed, and a zone b enclosing this, and a zone c composed of an outer discharge arc enclosing the zone b are formed. You. Furthermore, both discharge electrodes 6
Zone d is formed at each end of c and 6d. Each of these zones has a different color tone. FIG. 4 is a chart showing the wavelength distribution of each of the zones a to d shown in FIG. As can be easily understood from this diagram, the zone a composed of the central arc and the zone b formed around it are sensuously recognized as white light, while the zone c composed of the outer arc has a reddish color tone. The zone d at the end of the electrode has a bluish color tone. As a result, FIG.
Color unevenness occurs in the light distribution pattern shown in FIG. The present invention has been made in view of the above circumstances, and there is no possibility that color unevenness will occur even if an HID bulb is used as a light source, and the original light distribution pattern of a projector-type headlamp (see FIG. 2). It is an object of the present invention to provide a projector-type headlamp which does not have a bad influence on (a pattern whose principle is shown in (B)).

[0004]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
According to the present invention, an HID bulb is provided near a first focal point of a reflector.
With the discharge part arranged, it was reflected by the reflector
Condensing the light beam with a convex lens to form a desired light distribution pattern
Projector type headlamp with the reflector
A large number of vertical streaks on at least part of the effective reflection surface
It is characterized by providing fine irregularities composed of That is,
Akira uses the fact that light of various wavelengths is mixed to produce white light, and the red light in zone c shown in FIG.
When mixing the bluish light, Ri also a near white light not perfect, the light close to the white light further, zone a, by mixing the white light b, and the sensual to be felt with the white light.

Various methods are conceivable for mixing the light. In the present invention, the light is appropriately reflected by reflecting the light on minute irregularities so that the light is lost in the simplest and most reliable manner and the loss of the light amount is slight. Give the scattering. However, FIG.
Since the light distribution pattern as shown in (B) is not adversely affected by the scattering, providing fine fine irregularities such as to cause the scattering in the horizontal direction without causing scattering in the vertical direction. However, in the present invention, the vertical direction does not mean the length direction but the vertical direction in a state where the headlight is used, and the horizontal direction means the horizontal direction similarly. According to the configuration of the present invention, H is placed near the first focal point of the reflector.
In a projector type headlight in which a discharge portion of an ID bulb is arranged and a light beam reflected by the reflector is condensed by a convex lens to form a desired light distribution pattern, at least a portion of an effective reflection surface of the reflector has a vertical shape. It is characterized by providing fine irregularities in the direction.

[0006]

According to the above arrangement, when the light emitted from the HID bulb is reflected by the reflector, the light is scattered and mixed by the fine irregularities, so that it becomes sensually perfect white light and no color unevenness occurs. . However, since the fine irregularities are formed in the vertical direction, the scattering mainly occurs in the left-right direction, and the scattering in the vertical direction hardly occurs. As a result, the light distribution pattern is not adversely affected,
There is no danger of projecting upward light to dazzle oncoming vehicles. Such actions and effects can be achieved without any particular adverse effects under the condition that the reflector is a projector-type headlight. The reason will be described below in comparison with a non-projector type headlamp. FIG. 5 shows a conventional headlamp in which a light source bulb is arranged near the focal point of a reflecting surface similar to a paraboloid of revolution, and a prism lens is provided so as to intersect the optical path of the light beam reflected by the reflecting surface. It is sectional drawing. Light beams emitted from the light source bulb 12 as indicated by arrows g and h are reflected by the reflection surface 10 formed on the inner surface of the lamp housing 9 according to the positions set to form a desired light distribution pattern by arrows g 'and arrow h. And reflected by the prism lens 11 to form a predetermined light distribution pattern. Therefore, the reflection surface 10
If fine irregularities are provided and scattered, a desired light distribution pattern cannot be obtained. In contrast, in the projector type headlamp illustrated in FIG. 2, a cut line is provided by the shade 4 and the light is collected and projected by the convex lens 3, so that the light is emitted from the light source bulb. Even if the light beam is scattered at the stage of being reflected by the reflector 1, the contour is then adjusted by the shade and condensed by the convex lens, so that the scattered light reflected by the reflector hardly affects the light distribution pattern. (Because the light distribution pattern is formed mainly by the shade and the convex lens thereafter). In particular, since the fine irregularities of the present invention are arranged in the vertical direction, they scatter in the left-right direction, but hardly scatter in the vertical direction. As a result, in the light distribution pattern, the most important horizontal cut line for not dazzling the oncoming vehicle is not affected by the scattering. For these reasons, color unevenness due to the HID bulb is prevented without adversely affecting the light distribution pattern.

[0007]

Next, an example in which the above-described means is applied to a projector type headlamp will be described. FIG. 1 shows an embodiment of a projector type headlamp according to the present invention in which color is prevented,
(A) is a vertical sectional view schematically drawn, and (B) is a front view of the reflector extracted and drawn. First of reflector 1 having two focal points (eg, consisting of a spheroid)
Positioned at the focal point, the discharge bulb portion 6 of the HID bulb 6
a is installed. 6b is a socket, 7 is a socket holder. The luminous flux emitted by the discharge in the discharge tube portion 6a is reflected by the reflector 1 and is provided with a cut line by the shade 4 (as described with reference to FIG. 2B, partially cut off). ), Frame 5
The light is condensed by the aspherical men's 8 supported by and is projected to the front of the lamp (to the left in the figure). Vertical fine to at least a portion of the effective reflective surface of the inner surface of the reflector 1
Fine irregularities 1a are provided. The fine unevenness in the vertical direction in the present embodiment is a large number of vertical streaks, and the method of forming this is not particularly limited, but the following two methods are recommended.
I. When a reflector is formed from a synthetic resin material, fine vertical irregularities are provided in a molding die.
B. When a reflector is formed from a metal material, a process of forming a vertical streak after the formation is performed. When the above-described fine vertical unevenness 1a is provided, even if colored light is emitted from the discharge tube portion 6a of the HID bulb 6, the fine unevenness causes horizontal light scattering due to horizontal scattering and mixing of white light. Becomes The thus-combined white light is provided with a cut line by the shade 4 and condensed by an aspherical convex lens to form a required light distribution pattern. However, when there is no need to provide a cut line (for example, when it is not necessary to consider that the oncoming vehicle is not dazzled), the shade 4
Installation can be omitted. As described above, H
Since the colored light caused by the ID bulb 6 can be whitened, coloring of the light distribution pattern can be completely prevented as long as there is no other cause of coloring (for example, a spectral phenomenon caused by the aspheric lens 8).

[0008]

According to the present invention, when the light emitted from the HID bulb is reflected by the reflector, the light is scattered and mixed by the fine irregularities, so that it becomes sensuously perfect white light. No color unevenness occurs. In particular, since the fine irregularities of the present invention are arranged in the vertical direction, they scatter in the left-right direction, but hardly scatter in the vertical direction. As a result, in the light distribution pattern, the most important horizontal cut line for not dazzling the oncoming vehicle is not affected by the scattering. For these reasons, there is an excellent practical effect that color unevenness due to the HID bulb is prevented without adversely affecting the light distribution pattern.

[Brief description of the drawings]

FIG. 1 shows one embodiment of a projector type headlamp according to the present invention, in which color formation is prevented, (A) is a schematic vertical cross-sectional view, and (B) is a front view of the extracted reflector. FIG.

FIGS. 2A and 2B are views for explaining a known technique relating to a projector type headlamp, in which FIG. 2A is a schematic side view, and FIG. 2B is a diagram illustrating a group of iso-illuminance curves when a screen is irradiated. FIG.

FIG. 3 is a longitudinal sectional view of a main part of the HID bulb, schematically showing a configuration of discharge arc light.

FIG. 4 is a chart showing a wavelength distribution of each of the zones a to d shown in FIG. 3, in which a horizontal axis indicates a wavelength and a color scale is provided.

FIG. 5 shows a conventional headlamp in which a light source bulb is arranged near the focal point of a reflection surface similar to a paraboloid of revolution and a prism lens is provided so as to intersect with the optical path of the light beam reflected by the reflection surface. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reflector, 1a ... Vertical fine unevenness, 2 ... Light source bulb, 3 ... Convex lens, 4 ... Shade, 5 ... Frame,
Reference numeral 6: HID bulb, 6a: discharge tube portion, 6b: socket, 6c, 6d: discharge electrode, 7: socket holder, 8:
Aspherical convex lens, 9 ... Lamp housing, 10 ... Reflective surface, 11 ... Prism lens, 12 ... Light source bulb, F1 ...
First focus, F2... Second focus.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ identification code FI // F21W 101: 10 F21Y 101: 00 (58) Investigated field (Int.Cl. ⁷ , DB name) F21S 8/10 F21V 7 / 00 F21V 13/00 F21W 101: 10

Claims (1)

(57) [Claims] 1. A projector type headlamp in which a discharge section of an HID bulb is arranged near a first focal point of a reflector, and a light beam reflected by the reflector is condensed by a convex lens to form a desired light distribution pattern. A projector-type headlamp in which color formation is prevented, wherein at least a part of an effective reflection surface of the reflector is provided with fine irregularities including a large number of vertical streaks .