JPH0251201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automobile headlamp, and more particularly to an automobile headlamp which has been improved to be suitable for a flat headlamp.

The conventionally commonly used automobile headlights are
It has a structure in which a lamp is installed near the focal point of a single parabolic mirror of revolution, and a lens is installed in front of it, but such a simple configuration is not effective when trying to store a headlamp in a limited space. The available luminous flux is small, and especially when a flat headlamp is constructed, the effective luminous flux is reduced.

In order to eliminate these problems, we have developed an automotive electric light reflector that, during use, has a medium-low body that has a non-circular front opening through which light passes, a rear opening for receiving the light source, and an internal reflective surface. , wherein the reflective surfaces are (a) respectively disposed on opposite sides of the rear opening and extending laterally of the body toward the front opening and spaced apart from the rear opening;
a pair of first reflective parts; (b) a pair of second reflective parts disposed between each of the first reflective parts and the rear opening;
and (c) a third reflecting section disposed above the rear aperture between the pair of first reflecting sections, wherein each of the second and third reflecting sections has a focal length of each of the first reflecting sections. Automotive lamp reflectors with shorter focal lengths have been proposed, but they have the following technical difficulties.

In other words, during normal driving, automobile headlights can switch between the main light that illuminates the front of the vehicle almost horizontally, and the auxiliary light that illuminates the vehicle's own lane slightly downward to avoid dazzling oncoming vehicles. This switching is carried out depending on the use of the main filament and the sub-filament, but in the reflector with the above configuration, the hot zone of the auxiliary light and the cut line of the auxiliary light are formed by the same reflective surface. Therefore, there is little freedom in design and it is difficult to obtain a good light distribution pattern. Further, it is difficult to increase the oblateness of the overall shape of the headlamp.

The present invention has been made in view of the above-mentioned circumstances, and can be applied to automobile headlamps with a large oblateness ratio to increase the usable luminous flux, and can be applied to flat headlamps with a large lens emitting area to increase depth. It is an object of the present invention to provide an automobile headlamp whose dimensions can be reduced.

In order to achieve the above object, the automotive headlamp of the present invention has a light source installed near the focal point of the reflector, in which the reflective surface of the reflector is positioned near the center and at the periphery. , a middle part, and each of the above parts is divided into an upper half and a lower half, and for the reflective surfaces in these six areas, (i) the focal length of the reflective surface in the peripheral part is the upper half, The focal length of both the lower halves is approximately equal to the focal length suitable for projecting the light emitted from the light source forward as a parallel beam of light (hereinafter referred to as the standard focal length), and (ii) the focal length of the reflective surface in the center is: Both the upper and lower halves are shorter than the standard focal length.(iii) The focal length of the middle reflective surface is an intermediate value between the focal length of the central reflective surface and the standard focal length.(iv) And, the focal position of each upper half of the peripheral part, central part, and intermediate part is the same point, and the focal position of each lower half part of the peripheral part, central part, and intermediate part is the same point, and these lower half parts are set to the same point. It is characterized in that the focal position of the half part is closer to the back than the focal position of the upper half part.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 14.

FIG. 1A is a vertical longitudinal cross-sectional view of an embodiment of an automobile headlamp according to the present invention.

1 is a reflector, 2 is a lens provided in front of the reflector, 3 is a light source provided near the focal point of the reflector, and Z-Z is a main optical axis.

The imaginary lines drawn on the surface of the reflector 1 are the boundaries of several types of paraboloids of rotation that make up the reflector, as will be explained in detail later, but these several types of paraboloids of rotation all have their principal optical axis Z-Z. This is the focal axis.

In this example, an H4 halogen lamp having a filament approximately parallel to the optical axis is used as the light source 3.
3a is a main filament, and 3b is a subfilament. The subfilament 3b is the light shielding member 3
c, and the downward light emission is masked. FIG. 1B is an explanatory diagram showing the arrangement of the filament of the H4 halogen lamp. Main filament 3a and sub filament 3b both have main optical axis Z-Z
The sub-filament 3b is disposed toward the front (to the left in this figure) of the lamp, and the main filament 3a is disposed toward the rear (to the right) of the lamp.

f ₁ and f ₂ are the focal positions of the paraboloid of revolution forming the reflector 1, as will be explained in detail later.

Figure 2 is a front view of reflector 1, Figure 3 is a front view of reflector 1.
FIG. 4 is a sectional view taken along line Y-Y in the figure, and FIG. 4 is a sectional view taken along line XX. 1c is a hole for attaching a light source.

As shown in FIG. 2, the reflective surface of the reflector 1 is divided into six areas as follows. The speckled areas are the spaces between the six areas and do not belong to any area.

The left and right peripheral parts of the reflector 1 are set concentrically with respect to the center point 0, and paraboloids p ₁ and p ₄ are formed at the upper part, and paraboloids p _{6 and 4} are formed at the lower part.
Form p ₁₀ . The reason why the boundaries l ₁ and l ₂ between the upper and lower parts are asymmetrical is to form a light distribution pattern, as will be explained in detail later, and to comply with traffic regulations (driving on the left or right) Left and right borders depending on
Set l ₁ and l ₂ .

In addition, for convenience of explanation of the effect, the upper part of the paraboloid p ₁ is named p _1a and the lower part is named p _2a . The boundary line l ₃ between p _1a and p _1b is a virtual line.

Set the center around the hole 1c at the center of the reflector 1, and set a paraboloid P ₅ at the top and a paraboloid P ₈ at the bottom.
, respectively.

A concentric intermediate part about the center point 0 is set between the above peripheral part and the center part, and paraboloids p ₂ and p 3 are placed above it, and paraboloids p ₇ and p ₃ are placed below it. Form ₉ . For convenience of explanation, the upper part of the paraboloid p ₂ is p _2a ,
Name the bottom part p _2b . The boundary line _l4 is an imaginary line.

Among the paraboloids p ₁ to _{p 10} described above, the focal lengths of the peripheral paraboloids p ₁ , p ₄ , p ₆ , and p ₁₀ are configured to be standard focal lengths. In this example, F=38mm
It is. When carrying out the present invention, good results can be obtained when F=30 to 45 mm under general conditions of use.

The focal lengths of the central paraboloids p ₅ and p ₈ are configured to be shorter than the standard focal length. In this example F=22
mm. When carrying out the present invention, good results can be obtained when F=18 to 25 mm under general conditions of use.

The focal lengths of the paraboloids p ₂ , p ₃ , p ₇ , p ₉ in the middle part are:
The focal length is set to an intermediate value between the focal length at the center and the focal length at the periphery. In this example, F=28 mm.
In carrying out the invention, the general conditions are that F=
Good results can be obtained with a diameter of 20 to 35 mm.

The focal positions of each of the above-mentioned paraboloids p ₁ to p ₁₀ are set as follows. In other words, the focal positions of the upper half paraboloids p ₁ , p ₂ , p ₃ , p ₄ , p ₅ are the same in each of the central, intermediate, and peripheral parts, and the lower half paraboloid The focal position of p ₆ , p ₇ , p ₈ , p ₉ , p ₁₀ is set to 1 point closer to the back than the above focal position.
Match the points.

In this example, the lower half paraboloids p ₆ , p ₇ , p ₈ ,
The focal position f ₁ of p ₉ and p ₁₀ is approximately aligned with the position of the main filament 3a as shown in FIG. 1B.
Focal position f ₂ of paraboloids p ₁ , p ₂ , p ₃ , p ₄ , p ₅ in the upper half
is set 2mm ahead of _f1 . This causes the focal point f ₂ to be slightly in front of the main filament 3a. When implementing the present invention, the distance between the focal points f ₁ and f ₂ is set to 0.5
A setting of ~3.5 mm gives good results under typical conditions.

When the light emitted from the light source is reflected by the reflector 1 configured as described above, a light distribution pattern as shown in FIGS. 5 to 7 is obtained without the lens 2.

Figure 5 shows the light distribution when the light emitted from the subfilament is reflected by each of _{the paraboloids p 1 to p 5 .} The zones of light reflected by _E5 are shown in correspondence with each other. Zone E _1b is the reflected light from the upper part p _1a of the paraboloid p ₁ , and zone E _1b is the reflected light from the lower part p _1b of the paraboloid p ₁ . Similarly, zones E _2a and E _2b have p _2a and
Compatible with _p2b . The scales attached to the vertical and horizontal axes indicate the direction of light projection, and represent the angle (unit: degrees) made with respect to the central axis.

The light distribution pattern of the light flux emitted from the main filament 3a is shown in exploded form in FIGS. 6 and 7.
FIG. 6 shows zones E ₁ , E ₂ , E ₃ , E ₄ , E ₅ of the luminous flux reflected by the paraboloids p ₁ , p ₂ , p ₃ , p ₄ , p ₅ in the upper half.

Figure 7 shows the paraboloids p ₆ , p ₇ , p ₈ , p ₉ , p ₁₀ in the lower half.
Zones of the luminous flux reflected by E ₆ , E ₇ , E ₈ , E ₉ , E ₁₀
It shows. As shown in FIG. 1B, the position of the main filament 3a is at the focal point of the paraboloid _p6 to _p10 .
Since it almost coincides with f ₁ , the luminous fluxes reflected by the paraboloids p ₆ and p ₁₀ together form an almost parallel strong luminous flux zone E _6,10 . Similarly, the paraboloid p ₇ ,
The light reflected by p ₉ also forms zone E _7,9 .

The focal point f ₂ of the paraboloids p ₁ to _{p 5} in the upper half forming the zones E ₁ to _{E 5} shown in FIG. Since it is biased towards the front, the reflected light zone E ₁
~ _E5 , as shown in this figure, has a light distribution pattern that tends to diverge slightly upwards from the horizontal direction.

Since the sub-filament 3b is provided in front of the main filament and located in front of the focal point _f2 of the paraboloids _p1 to _p5 in the upper half, the light distribution of the sub-filament shown in FIG. shows a tendency to diverge downward from the horizontal direction. However, the paraboloid
Since the focal lengths of p ₁ and p ₄ are longer than those of the other paraboloids p ₂ , p ₃ and p ₅ , the deviation between the focal position and the light source is less likely to affect the paraboloids p 1 and p ₁ as shown in the figure. Upper and lower p _1a ,
Zones of light reflected by p _1b E _1a , E _1b and paraboloids
The zone _E4 of the light reflected by _p4 exhibits properties close to a parallel light beam and forms a hot zone of the auxiliary light beam.

As shown in FIG. 1, the subfilament 3b
Since the lower part of is masked by the light shielding member 3c, there is no luminous flux reflected by the paraboloids _p6 to _p10 in the lower half, and therefore the upper half of the light distribution pattern in FIG. It is cut.

The automobile headlamp of this embodiment can obtain the light distribution pattern of the reflected luminous flux as described above.
The light distribution is adjusted by the lens 2, and the following light projection performance can be obtained.

Regarding the auxiliary light, which is dimmed to avoid dazzling oncoming vehicles, it should be placed in the same way as zone E _2b shown in Figure 5, so as not to project upward into the direction of oncoming traffic.
E ₃ is used to form projected light fluxes I _2b and I ₃ as shown in FIG.

Further, the hot zone of the auxiliary light projection uses the zones E _1a and E ₄ shown in FIG. 5 to form the projection light fluxes I _1a and I ₄ as shown in FIG. 9.

Then, the zone _E5 shown in FIG. 5 is used as a wide downward light beam for auxiliary light projection, and a narrow light beam _I5 shown in FIG. 10 is formed.

A light distribution pattern for auxiliary light projection as shown in FIG. 11 is obtained by combining the projected light beams shown in FIGS. 8, 9, and 10 described above.

The prism shape of lens 2 is as shown above (Figure 10).
Set so that the light distribution pattern of the auxiliary light is obtained. Thereby, the luminous flux of the main light projection is determined as follows.

FIG. 12 shows the light distribution pattern of the projected light fluxes I ₁ to _{I 5} formed by the zones E ₁ to E ₅ shown in FIG. 6, and FIG. ₆ ～
This is a light distribution pattern of projected light fluxes I ₅ to I ₁₀ formed by E ₁₀ .

By combining the light distribution patterns shown in FIGS. 12 and 13 above, the central part has the maximum luminous intensity as shown in FIG. 14, and a main light distribution pattern suitable for normal driving can be obtained.

As described above, the automobile headlamp of this embodiment has a light distribution pattern formed by paraboloids at 10 locations: top and bottom of the center, middle part, top and bottom of the periphery, and left and right. , the degree of freedom in design is large, and a large amount of luminous flux can be utilized even in a headlamp with a large aspect ratio. Further, it is also easy to design the lens to have a large light emitting area and a small depth dimension.

When designing an automobile headlamp by applying the present invention, the peripheral paraboloids p ₁ , p ₄ , p ₆ ,
p ₁₀ to form the maximum luminous intensity part of the main and auxiliary lights, and the paraboloid in the center
p ₅ and p ₈ are set so that the main and auxiliary light emitters form a wide light projection pattern in the downward direction, and the paraboloids p ₂ , p ₃ , p ₇ , and p ₉ in the middle part are Therefore, by setting the auxiliary light to form a cut line, it is easy to obtain excellent reflection characteristics. Further, by creating a desired light distribution pattern of reflected light in this manner, a projected light beam having a suitable light distribution pattern can be obtained using a lens with a simple configuration.

As described in detail above, according to the present invention, it is easy to increase the luminous flux to be used in a vehicle headlamp having a large aspect ratio and fit it within a limited installation space. Further, in a flat automobile headlamp having a large lens light emitting area, it is easy to set the depth small and fit it into a narrow space.

[Brief explanation of the drawing]

The attached drawings show an embodiment of the automobile headlamp of the present invention, in which FIG. 1A is a vertical cross-sectional view and FIG. 1B is a vertical cross-sectional view.
FIG. 2 is a front view of a reflector, FIG. 3 is a YY sectional view of FIG. 2, and FIG. 4 is a XX sectional view of the same. Figures 5 to 7 are diagrams for explaining the light distribution pattern of reflected light when there is no lens, and Figures 8 to 14 are diagrams for explaining the light distribution pattern of the luminous flux that has passed through the lens, respectively. This is a diagram. 1... Reflector, 1c... Hole for attaching the light source,
2... Lens, 3... H4 halogen lamp as a light source, 3a... Main filament, 3b...
Subfilament, 3c... Light shielding member, p ₁ , p ₂ ~
p ₁₀ ……paraboloid of revolution that constitutes the reflective surface of the reflector,
E ₁ ~ _{E 10} ... Zone of reflected light by the above paraboloid,
_I1 to _I10 ...Projected light flux whose light distribution is modified by the lens.

Claims (1)

[Claims] 1. In an automobile headlamp in which a light source is installed near the focal point of a reflector, the reflective surface of the reflector is divided into a central area, a peripheral area, and an intermediate area, and An automobile headlamp characterized in that each of the six sections is divided into an upper half and a lower half, and each of the reflecting surfaces of these six sections is constituted by a paraboloid of revolution as described below. (i) The focal length of the peripheral reflective surface for both the upper and lower halves is a focal length suitable for projecting the light emitted from the light source forward as a parallel beam of light (hereinafter referred to as the standard focal length). Make them approximately equal. (ii) The focal length of the central reflective surface should be shorter than the standard focal length for both the upper and lower halves. (iii) The focal length of the intermediate reflective surface is an intermediate value between the focal length of the central reflective surface and the standard focal length. (iv) The focal positions of the upper halves of the peripheral, central, and intermediate areas are set to the same point. (v) The focal positions of the lower halves of the peripheral, central, and intermediate parts are set to the same point, and the focal positions of these lower halves are closer to the back than the focal position of the upper half.