JPH01231202A - Headlamp for vehicle - Google Patents

Abstract

PURPOSE:To sharpen the cut line of the upper side of the luminous intensity distribution pattern of a low beam by making the focal length of the intermediate range between the horizontal and diagonal parting lines of a reflection surface smaller than the remainder range, and arranging a light source to the position near the intermediate range side in the upper part than the horizontal parting line. CONSTITUTION:The focal length of the range 5 and 5' between the horizontal and diagonal parting lines alpha-alpha and beta-beta of the four ranges 5, 5', 6, and 6' of a reflection surface 4 is made slightly smaller than that of long focal ranges 6 and 6', and the optical axes of the short focal ranges 5 and 5' and the ranges 6 and 6' are made to coincide with each other. An electric lamp 7 is arranged to the position where the center part of a filament 12 is near diagonally to the upper right of a reflecting mirror 2. This enables the luminous intensity distribution of an oblong and an extremely sharp cut line of the upper side to be made, and also the use effectiveness of light to be improved.

Description

[Detailed description of the invention] The vehicle headlamp of the present invention will be explained according to the following items.

A. Industrial field of application B1 Overview of the invention C1 Prior art [Figures 9 and 10] D1 Problems to be solved by the invention [Figures 9 to 12
[Figure] E1 Means F for solving the problem, Example [Figures 1 to 8] F-1, First embodiment [Figures 1 to 5] A1 reflecting mirror, light source C1 arrangement Light F-2, Second Embodiment [FIGS. 6 to 8] G1 Effects of the Invention (A. Field of Industrial Application) The present invention relates to a novel vehicle headlamp. Specifically, it relates to a vehicle headlamp that includes a light source and a reflecting mirror that has a paraboloid of revolution shape and reflects light from the light source forward, and the reflecting surface is set at a focal length. By dividing the light source into multiple areas with different brightness and by carefully arranging the position of the light source relative to the reflective surface, the desired light distribution pattern for this type of headlamp can be achieved without the need for a light shield that blocks part of the light from the light source. This makes it possible to maintain a high utilization efficiency of light from the light source, and also to clearly create a bright and dark boundary line (hereinafter referred to as "cut line") of the light distribution pattern. The purpose of the present invention is to provide a new vehicle headlamp that can provide sharp light distribution.

(B. Summary of the Invention) A vehicle headlamp of the present invention is a vehicle headlamp comprising a reflecting mirror having a paraboloid-shaped reflecting surface and a light source disposed within the reflecting mirror. , the reflective surface is divided into an intermediate region located on the upper right side and the lower left diagonally across the optical axis of the reflective surface when viewed from the front, and the remaining region, and the focal length of the reflective surface forming the intermediate region. A light shielding body that has a light source that is slightly smaller than the focal length of the remaining reflective surface and is located closer to the upper intermediate region, thereby blocking part of the light from the light source from the reflective surface. Even without providing a light distribution pattern, it is possible to obtain a passing beam light distribution pattern in which there is no light distribution portion above the horizontal line on the oncoming lane side and a light distribution portion above the horizontal line on the driving lane side, and the light distribution pattern This allows the upper cut line to be sharp.

(C, Prior Art) [Figure 9, Factor 10] Vehicle headlights are normally required to have a horizontally elongated light distribution pattern, and among these, the light distribution pattern of a passing beam is a horizontal line on the opposite lane side. It is required that there is no light distribution part higher up, and there is a light distribution part above the horizontal line on the driving lane side.

FIG. 9 shows m pieces (a) of conventional vehicle headlights for illuminating light according to such a light distribution pattern.

In the figure, b is a reflecting mirror and has a reflecting surface C in the shape of a paraboloid of revolution. Reference numeral d designates a light bulb, in which a filament f is provided within the glass bulb e, and a shade g is provided that covers the front surface and approximately the lower half of the filament f.

The light bulb d is attached to the reflector 1tb with its filament f located slightly in front of the focal point of the reflective surface C.

According to such a vehicle headlamp a, the light emitted from the filament f enters only the upper half of the reflecting surface C of the reflecting mirror from the optical axis x-x of the reflecting surface C. Since it is reflected forward, the luminous flux is h as shown in Figure 10.
The pattern will be like this.

In addition, in FIG. 10 and other light distribution pattern diagrams, H
-H line is a horizontal line that is perpendicular to the optical axis of the reflector in front of the headlamp, and V-V line is a vertical line that is also perpendicular to the optical axis.

The light beam is shaped and irradiated by a control lens (not shown) disposed in the front opening of the reflection utb, thereby forming the light distribution pattern 7i shown in the figure. The cut line j on the upper side of the light pattern i is clearly defined by the shade g and becomes extremely sharp.

(D. Problems to be Solved by the Invention) [Figures 9 to 12] According to such a headlamp a, the light distribution pattern by the light flux emitted from the reflecting mirror forward can be adjusted to the final required light distribution pattern. Since it can be made relatively close to the light distribution pattern, the burden on the control lens is light, and there is an advantage that the cut line on the upper side of the light distribution becomes sharp.

However, in order to convert the reflected light into a luminous flux with such a pattern, a part of the light from the filament f, which is the light source, toward the reflective surface C is blocked by the shade g, so the efficiency of using the light from the light source is extremely low. There's a problem.

Therefore, it is possible to make the light distribution pattern of the light flux emitted from the reflector close to the light distribution pattern desired for vehicle headlights without blocking part of the light from the light source. In order to do this, I considered the headlight k shown in FIG.

In the figure, l is a reflecting mirror, and this reflecting mirror 1 has a reflecting surface m in the shape of a paraboloid of revolution, and has a shape similar to cutting off both the upper and lower ends of the paraboloid of revolution, that is, the optical axis It has a horizontally long rectangular shape when viewed from the direction along
A dividing line o-o that extends diagonally orthogonally to n and the optical axis
The area p, p' (hereinafter referred to as the "intermediate area") between the two dividing lines n-n and o-o is ) is smaller than the focal length of the remaining regions q and q'.

F is a focal point common to the intermediate regions p, p' and horizontal regions q, q' of the reflective surface m, r is a C-8 type filament, and the center of the filament r is located slightly above the focal point F. and parallel to the optical axis x1.

According to such a headlamp k, the first beam is emitted from the filament r and reflected by the reflector m.
A light distribution pattern S shown in FIG. 2 is formed. That is, the light emitted from the filament r and reflected by the intermediate regions p and p' of the reflective surface m forms a partial light distribution t with diagonal lines downward to the left of the light distribution pattern S. The light reflected by the remaining regions q and q' forms a partial light distribution U with diagonal lines downward to the right, and a partial light distribution t
forms an elongated pattern whose center is located diagonally to the left below the optical axis X, and which is slanted downward to the right, approximately at the center in the vertical direction of the entire light distribution pattern S. are doing.

Therefore, this light distribution pattern S has a light distribution pattern desired for a vehicle headlamp, that is, a pattern similar to the light distribution pattern i shown in FIG. is not blocked from the reflecting surface m, so
It is possible to maintain high utilization efficiency of light from the light source.

However, the cut line V of this light distribution pattern S
In the partial light distribution t, which is an element for forming The problem is that it doesn't come out.

(E. Means for Solving the Problems) Therefore, in order to solve the above-mentioned problems, the vehicle headlight of the present invention has the reflecting surface of the reflector in the shape of a paraboloid of revolution when viewed from the front. It has a horizontally elongated substantially rectangular shape and is divided into four regions by a dividing line extending horizontally perpendicular to the optical axis and a dividing line extending in a diagonal direction perpendicular to the optical axis, and The focal length of the intermediate area, which is the area between the dividing line and the diagonal dividing line, is made smaller than the focal length of the remaining area, and the focal length is moved closer to the intermediate area located above the horizontal dividing line when viewed from the front. A light source is placed at a certain position.

Therefore, according to the vehicle headlamp of the present invention, the light reflected by the area other than the intermediate area of the reflecting surface of the reflector causes the light distribution to have a horizontally long pattern approximately along the horizontal line in front of the lamp. The light reflected by the intermediate region creates a long and narrow pattern of light distribution along the upper edge of the light distribution and in a direction slightly inclined with respect to the horizontal line. Since the position is closer to the intermediate area above the horizontal dividing line, the light reflected from the part along the diagonal dividing line in the intermediate area will be biased towards the upper edge of the light distribution. The upper edge of the light distribution due to the light reflected in the area will create a very clear bright border. This results in a light distribution that is horizontally long as a whole and has an extremely sharp cut line on the upper side, and does not partially block the light from the light source from the reflective surface, making it easier to utilize the light. Efficiency becomes very high.

(F. Embodiment) [FIGS. 1 to 8] Details of the vehicle headlamp of the present invention will be described below in accordance with each embodiment shown in the accompanying drawings.

(F-1, First Embodiment) [Figures 1 to 5] Figures 1 to 5 show a first embodiment 1 of the vehicle headlamp of the present invention.

(a, reflective mirror) 2 is a concave reflective mirror made of synthetic resin, which has a substantially rectangular opening 3 that is long in the left and right direction, and the inner surface 4 of the wall excluding both upper and lower ends is coated with an aluminum vapor-deposited film. etc., making it a reflective surface with high light reflectivity.

4 The reflecting surface 4 has a paraboloid of revolution shape and is divided into the following four regions. That is, x
-x is the optical axis of the reflective surface 4, V-V is a vertical line that extends perpendicularly to the optical axis x-x, and α-α is a vertical line that is perpendicular to the optical axis x-x when looking at the reflective surface 4 from the front. The dividing line that extends horizontally (hereinafter referred to as the "horizontal dividing line"), and β-β are the same as the optical axis X-
It is a dividing line that extends diagonally downward to the left and perpendicular to It is divided into four regions 5.5' and 6.6' by.

Therefore, among these four regions 5.5' and 6.6', the region 5.5 between the horizontal dividing line α-α and the diagonal dividing line β-β.
5' (this is the "intermediate region". This region is hereinafter referred to as the "short focus region") is approximately horizontally wedge-shaped, and the tip of the wedge is aligned with the optical axis x. -x, and one short focus area 5 (hereinafter referred to as "upper short focus area") is located on the right side of the vertical line v-v, with its lower edge touching the horizontal dividing line α-α. and the other short focus area 5'
(hereinafter referred to as the "lower short focus area") is the vertical line V-
On the left side of V, its upper edge is located in contact with the horizontal dividing line α-α. Further, the remaining area 6.6' (hereinafter referred to as "long focal area") has a substantially anisosceles trapezoidal shape that is long in the left-right direction.

Furthermore, the focal length of the short focus area 5.5' is the same as that of the long focus area 6.5'.
The focal length of the short focus area 5.5' and the long focus area 6.6' coincide with each other, and the focal length of each focal point 1+ (the upper long focus area 6 ), fl (focal point of the lower long focal region 6'), f, (focal point of the short focal region 5.5') are f from the front side.
They are located with phase spacing in the order of 1, fs, and f.

Note that these short focus areas 5.5' and long focus areas 6.6'
The specific focal length of the paraboloid of revolution forming the short focal region 5.5' is approximately 20 mm in this embodiment, although the specific focal length of the long focal region 6.5' is not necessarily defined. The focal point VP of the paraboloid of revolution forming 6'! s is approximately 25 mm.

(b, light source) 7 is a halogen light bulb. Reference numeral 8 designates a glass bulb of the light bulb 7, the proximal end of which is held in the cap 10 by a holding band 9, and the distal end surface 8a thereof is treated to have light-shielding properties, and lead wires 11, 11 glass bulb 8
A filament 12 is arranged in an arched manner between the tips of the inner portions.

The light bulb 7 has its filament 12 connected to the reflector 2.
1 extending parallel to the optical axis x-x of
The center of the filament 12 is located diagonally upward to the right from the focal points f1, 2, and f when looking at the reflecting mirror 2 from the front, that is, on the side of the upper short focus area 5. It is placed in a close position. The positions of the filament 12 with respect to the focal points f, f2, f3 are as follows: f corresponds to the center of the filament 12, f,
corresponds to the front end of the filament 12, and fl corresponds to the rear end of the filament 12.

(c. Light Distribution) In such a vehicle headlamp 1, the light emitted from the filament 12 of the light bulb 7 forms a light distribution pattern 13 as shown in FIG.

That is, the light emitted from the filament 12 is incident on substantially the entire area of the reflecting surface 4 of the reflecting mirror 2 and is reflected forward. Of these, a partial light distribution 14 is formed, and the partial light distribution 1 is formed by light reflected by the short focus area 5.5'.
5 is formed.

The filament 12 then has two short focus areas 5.5'
The light reflected by the portion 16 along the diagonal dividing line β-β of these short focus areas 5.5' is located near the area 5 located above the horizontal dividing line. For example, the portion 16 along the diagonal dividing line β-β is divided into four divided areas 16a, 16a', 16b11 in the order of distance from the optical axis x-x.
6b', 16c, 16c' and 16d116d'', each zone 15a, 15b, 15c and 15d of the partial light distribution 15 is formed by the light reflected by these divided areas, and each zone 15a, 15b,
The upper edges of 15c and 15d are located approximately on a straight line.

Therefore, the light distribution pattern 13 obtained by this vehicle headlamp l before passing through the lens is that there is no light on the right side of the vertical line V-V among the areas above the horizontal line H-H in front of the lamp, and the vertical line v
-The pattern has an upwardly directed portion on the left side of the pattern ``-'', and the upper edge 13a, which is the cut line, becomes extremely sharp.

Then, such a light distribution pattern is reflected from the filament 12, t! Since the light directed toward the reflective surface 4 of 2 can be obtained without blocking it at all, the efficiency of using the light from the light source is extremely high.

Although not shown, it goes without saying that the light distribution pattern 13 can be arranged using a lens to obtain a final light distribution pattern.

(F-2, Second Embodiment) [Figs. 6 to 8] Figs. 6 to 8 show a second embodiment 17 of the vehicle headlamp of the present invention.

The vehicle headlamp 17 shown in this second embodiment is different from the vehicle headlamp 1 shown in the first embodiment in that the light sources are one for a passing beam and one for a running beam. There are only two points. Therefore, the structure will be explained only with respect to the above-mentioned differences, and other points will be given the same reference numerals as those given to similar parts of the vehicle headlamp 1 in the first embodiment. Omitted by.

Reference numeral 18 denotes a light bulb, in which two filaments 19 and 20 are arranged so as to extend parallel to each other, and these two filaments 19 and 20
One of the filaments 19 (hereinafter referred to as "r main filament") serves as a light source for the traveling beam, and the other filament 2
0 (hereinafter referred to as "sub-filament") serves as a light source for the passing beam.

The light bulb 18 is oriented such that the filaments 19 and 20 extend parallel to the optical axis x-x of the reflector 2, that is, C-8/
It has a C-8 type filament arrangement. The center of the main filament 19 is arranged at a position slightly below the focal point f, f2, f of the reflecting mirror 2 and closer to the lower short focus region 5', and the sub filament 20 The filament 12 is located at the same position relative to the reflecting mirror 2 in the embodiment.

Therefore, depending on the light emitted from the sub-filament 20 and reflected by the reflective surface 4, a light distribution pattern similar to the light distribution pattern 13 shown in FIG. 5 is formed, and
The light emitted from the main filament 19 and reflected by the reflective surface 4 forms a light distribution pattern 21 as shown in FIG. The pattern appears to be reversed both vertically and horizontally. That is, the light emitted from the main filament 19 and reflected by the long focal region 6.6' of the reflective surface 4 forms a partial light distribution 22 whose upper end is above the horizontal line H-H and which spreads downward in a fan shape. Focal area 5.5
A horizontally long partial light distribution 23, most of which is above the horizontal line H-H, is formed by the light reflected by '.

This light distribution pattern 21 is adjusted by a lens (not shown) to obtain a light distribution pattern required as a traveling beam.

(G. Effects of the Invention) As is clear from the above description, the vehicle headlamp of the present invention has a substantially horizontally elongated rectangular opening and a reflective surface having a paraboloid of revolution shape. The reflecting surface is divided into four areas by a dividing line extending horizontally perpendicular to the optical axis and a dividing line extending in a diagonal direction perpendicular to the optical axis when viewed from the front. , the focal length of the intermediate area, which is the area between the horizontal dividing line and the diagonal dividing line, is smaller than the focal length of the remaining area, and the intermediate area located above the horizontal dividing line when viewed from the front. A feature is that the light source is placed closer to the area.

Therefore, according to the present invention, the light reflected by the area other than the intermediate area of the reflective surface of the reflecting mirror is distributed in a horizontally long pattern substantially along the horizontal line in front of the lamp, and the intermediate area is The reflected light creates a long and narrow pattern of light distribution along the upper edge of the light distribution and a direction slightly inclined with respect to the horizontal line, and the position of the light source is located near the horizontal dividing line. By shifting toward the upper intermediate region, the light reflected from the portion of the intermediate region along the diagonal dividing line will be biased toward the upper edge of the light distribution, so that the light reflected from the intermediate region will be biased toward the upper edge of the light distribution. The upper edge of the light distribution creates an extremely clear boundary between light and dark.

This results in a light distribution that is horizontally long as a whole and has an extremely sharp cut line on the upper side, and does not partially block the light from the light source from the reflective surface, increasing the efficiency of light use. becomes very expensive.

In each of the above embodiments, a headlight for left-hand light distribution, that is, a headlight commonly used for vehicles driving on the left side, was shown, but the present invention is applicable to a headlight for right-hand light distribution. When used as a light, the reflective surface is divided into four areas by a dividing line extending horizontally perpendicular to the optical axis when viewed from the front and a dividing line extending diagonally downward to the right and perpendicular to the optical axis. In addition to dividing the beam, the light source for the passing beam should be placed above the horizontal dividing line and to the left of the vertical line when viewed from the front.Also, if a light source for the traveling beam is also provided, the light source should be placed above the horizontal dividing line and to the left of the vertical line. It may be placed below the horizontal dividing line and to the right of the vertical line.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the vehicle headlamp of the present invention, in which FIG. 1 is a front view with the lens removed, FIG. 2 is a perspective view with the lens removed, and FIG. 3 is a perspective view with the lens removed. The figure is III- in Figure 1.
A cross-sectional view taken along line III, FIG. 4 is taken from IV-IV in FIG.
5 is a sectional view taken along the line, FIG. 5 is a light distribution pattern diagram, FIGS. 6 to 8 show a second embodiment of the vehicle headlamp of the present invention, and FIG. 6 is a front view excluding the lens. Figure 7 is a sectional view taken along the line ■-■ in Figure 6, Figure 8 is a light distribution pattern diagram, and Figure 9 is a cross-sectional view taken along the line ■-■ in Figure 6.
The figures show an example of a conventional vehicle headlamp. (A) is a longitudinal cross-sectional view without the lens, (B) is a front view without the lens, and Figure 10 is the vehicle headlight shown in Figure 9. Figures 11 and 12 show an example of a prototype of a wheel headlight, and Figure 11 is a front view with the lens removed.
FIG. 12 is a light distribution pattern diagram. Explanation of symbols! ...Vehicle headlight, 2...Reflector, 3...
Opening part, 4... Reflective surface, 5.5'... Intermediate area, 5... Intermediate area (located above the horizontal dividing line),
12... Light source, x-x... Optical axis, α-α... Horizontal dividing line, β-β... Diagonal dividing line, 17... Vehicle headlamp, 20... Light ■
3 Opening Figure 3 CO room 5 Kyoichi ~ Bar, ? -♀NV / / 1 / Nishimi Cavatare Figure 5-JB) 6 -…
-〇191 ToV
21 Cover pattern diagram (second embodiment) Figure 8 Longitudinal sectional view C1L conventional example) Figure 9 (A) Front view (conventional example) Figure 9 (B) Cover pattern (conventional example) Front view (draft example), ＼. Figure 12: Pattern diagram (draft example)

Claims (1)

[Scope of Claims] A reflecting mirror having a substantially horizontally elongated rectangular opening and a reflecting surface in the shape of a paraboloid of rotation, the reflecting surface being horizontal and perpendicular to its optical axis when viewed from the front. The area is divided into four areas by the extending dividing line and the dividing line extending in one diagonal direction perpendicular to the optical axis, and the focal point of the intermediate area is the area between the horizontal dividing line and the diagonal dividing line. A vehicle headlamp characterized in that the distance is smaller than the focal length of the remaining region, and the light source is disposed at a position closer to the intermediate region above the horizontal dividing line when viewed from the front.