JP2024072312A - Vehicle headlights - Google Patents

Abstract

[Problem] To provide a sufficient amount of light even in a long and narrow vehicular headlamp. [Solution] A vehicular headlamp including a first reflector 21A, a first light source 31A, a second reflector 21B, and a second light source 31B, in which the first light source 31A is arranged so that light emitted by the first light source 31A is reflected by the first reflector, and the second light source 31B is arranged so that light emitted by the second light source 31B is reflected by the second reflector, the first reflector 21A and the second reflector 21B are arranged side by side in a predetermined direction, the main direction of the light emitted by the second light source 31B is the predetermined direction, the second reflector 21B has a long side in the predetermined direction as viewed from the lamp irradiation direction, and the main direction of the light emitted by the first light source 31A is different from the predetermined direction. [Selected Figure] Figure 3

Description

This invention relates to a vehicle headlamp.

Conventionally, vehicle headlamps have been known that use a reflector to reflect light from a light source in the direction the vehicle is traveling.

Patent document 1 describes a vehicle headlamp configuration that combines multiple reflector units each equipped with a light source and a reflector.

JP 2014-7106 A

The function of a vehicle headlamp is generally to illuminate the area in front of and far away from the vehicle to ensure the driver's visibility at night. In order to illuminate with the desired light distribution pattern, the headlamp reflector reflective surface needs to have both a reflective area close to the light source and a reflective area away from the light source.

In recent years, there has been a need to make vehicle headlamps thinner, i.e., to make reflectors thinner. However, there is an issue that making the reflector thinner reduces the area close to the light source or the area far from the light source.

The present invention was made in consideration of the above circumstances, and aims to provide a desired light distribution pattern in a long and narrow vehicle headlamp.

(Claim 1 and Claim 2) The present invention is a vehicle headlamp that combines a first reflector, a first light source, a second reflector, and a second light source, in which the second reflector has a long side in a predetermined direction and the main irradiation direction of the second light source is in the predetermined direction.
According to the present invention, even with a narrow reflector, it is possible to ensure a reflection area close to the light source and a reflection area distant from the light source.

(Claim 3) The second light source may have a greater luminous flux than the first light source.
According to the present invention, the luminous intensity of the high luminous intensity area in the light distribution pattern can be further improved.

(Claim 4) There may be at least two first reflectors.
According to the present invention, by providing two or more first reflectors, the amount of light emitted by the vehicle headlamp can be further increased.

(Claim 5) The first light source may be mounted on the same substrate.
By mounting multiple light sources on the same board, the number of boards can be reduced, simplifying the component configuration of the vehicle headlamp.

(Claim 6) A cutoff line may be formed by the second reflector 20B.
According to the present invention, since the second reflector is suitable for forming a small light source image with high luminance, it is possible to increase the illuminance in the vicinity of the cutoff line.

(Claim 7) A low beam light distribution may be formed by the first reflector and the second reflector, and a high beam light distribution may be formed by the third reflector.
According to the present invention, it is possible to form both a low beam light distribution that does not dazzle oncoming vehicles and a high beam light distribution that illuminates the entire area above and far away, using a single vehicle headlamp.

The present invention makes it possible to form a desired light distribution pattern.

1 is a front view showing a vehicle headlamp according to an embodiment of the present invention; 2 is a schematic diagram showing a cross section of the vehicle headlamp as seen from a side; FIG. FIG. 2 is a front view showing a reflector unit according to the embodiment of the present invention. FIG. 4 is a top view of FIG. 3 . 4A to 4C are diagrams showing a low-beam light distribution pattern formed by light emitted from the vehicle headlamp. 4A to 4C are diagrams showing a high beam light distribution pattern formed by light emitted from the vehicle headlamp. FIG. 4 is a diagram showing division of the reflecting surface area of the reflector unit of FIG. 3 . 7A and 7B are diagrams illustrating light distribution patterns for different reflecting surface areas in FIG. 6. FIG. 4 is a view similar to FIG. 3 , showing a vehicle headlamp according to a first modified example of the embodiment. FIG. 5 is a view similar to FIG. 3 , showing a vehicle headlamp according to a second modified example of the embodiment. FIG. 5 is a view similar to FIG. 3 , showing a vehicle headlamp according to a third modified example of the embodiment.

The following describes an embodiment of the present invention with reference to the drawings.

Figure 1 is a front view showing an outline of a vehicle headlamp 10 according to an embodiment. Figure 2 is a side cross-sectional view showing an outline of the vehicle headlamp 10.

The vehicle headlamp 10 has a lamp housing 11 with an opening in one direction, and an outer cover 12 attached to the opening to form a lamp chamber 13. The lamp housing 11 is made of a light-blocking material. The outer cover 12 is made of a light-transmitting material, such as polycarbonate resin (PC), acrylic resin (PMMA), or glass. A portion of the outer cover 12 may be painted. The outer cover 12 may be two-color molded or multi-color molded, combining a light-transmitting material and a non-light-transmitting material.

Reflector unit 20 and reflector unit 120 are housed inside lamp chamber 13. Reflector unit 20 is a low beam reflector unit, and reflector unit 120 is a high beam reflector unit.

The reflector unit 20 is fixed to the lamp housing 11 by aiming screws 14A and 14B and pivot parts (not shown). By rotating each aiming screw, the reflector unit 20 can be tilted vertically or horizontally.

Reflector unit 120 is fixed to lamp housing 11 with a structure similar to that of reflector unit 20. Reflector unit 20 and reflector unit 120 may be formed as an integral member. Reflector unit 20 and reflector unit 120 may be fixed to a common support member, and the common support member may be fixed to lamp housing 11 by each aiming screw and pivot member.

Figure 3 is a front view of the reflector unit 20. Figure 4 is a top view of the reflector unit 20. As shown in these figures, the reflector unit 20 has three first reflectors 21A arranged horizontally. In addition, a second reflector 21B is arranged next to the first reflectors 21A.

The first reflector 21A and the second reflector 21B are composed of a combination of reflective elements. The reflective elements are free-form surfaces based on paraboloids with a specified point as a focus, and each has a shape that forms part of the desired light distribution pattern. The curvature of each reflective element may be adjusted as appropriate.

The reflector unit 20 is made of a resin material, such as polycarbonate resin (PC) or unsaturated polyester resin (BMC). The reflective surface of the reflector unit 20 is surface-treated to reflect light by deposition of aluminum or other materials.

The reflector unit 20 may be made of a metal material such as aluminum or stainless steel. In this case, it is desirable that the reflective surface is polished to a mirror finish.

A first light source 31A is disposed above the first reflector 21A. The light of the first light source 31A is reflected by the first reflector 21A and irradiated in a predetermined light distribution pattern. The first light source 31A is mounted on a substrate 41A. The substrate 41A is fixed to the upper surface of the reflector unit 20. Fixing means for fixing the substrate 41A to the reflector include screw fixing, lance fixing or claw fixing, and thermal caulking.

In this embodiment, three first light sources 31A are mounted on one board 41A, but one first light source 31A may be mounted on one board 41A. In this case, there are as many boards 41A as there are first light sources 31A and first reflectors 21A. That is, in this figure, there may be three boards 41A.

When viewed from the front of the reflector unit 20, the second light source 31B is disposed on the right side of the second reflector 21B. The light of the second light source 31B is reflected by the second reflector 21B and irradiated in a predetermined light distribution pattern. The second light source 31B is mounted on a substrate 41B. When viewed from the front of the reflector unit 20, the substrate 41B is fixed to the right side of the reflector unit 20. Fixing means for fixing the substrate 41B to the reflector include screw fixing, lance fixing or claw fixing, and thermal caulking.

Reflector unit 120 has the same configuration as reflector unit 20. Reflector unit 120 has two third reflectors 121A arranged horizontally. A third light source 131A is arranged above third reflector 121A. Light from third light source 131A is reflected by third reflector 121A and irradiated as a predetermined light distribution pattern. First light source 131A is mounted on substrate 43A. Substrate 43A is fixed to the upper surface of reflector unit 20.

The first light source 31A and the second light source 31B are light-emitting elements, such as light-emitting diodes (LEDs), laser diodes, and organic electroluminescence (EL). The first light source 31A and the second light source 31B are powered by a power supply means (not shown), and are switched on and off by a predetermined operation by the driver. The same can be said for the third light source 131A.

When the vehicle headlamp 10 is turned on in low beam mode, power is supplied to the first light source 31A and the second light source 32A, and each light source is turned on. The light emitted from the first light source 31A is reflected by the reflecting surface of the first reflector 21A that the light source faces. The light emitted from the second light source 31B is reflected by the reflecting surface of the second reflector 21B that the light source faces. The reflected lights are combined to form the low beam light distribution pattern LB shown in FIG. 5.

When the vehicle headlamp 10 is turned on in high beam mode, power is supplied to the third light source 131A in addition to the first light source 31A and the second light source 32A, and each light source is turned on. Light emitted from the third light source 131A is reflected by the reflective surface of the third reflector 121A that the light source faces. The lights reflected by the third reflector are combined to form the upward light distribution pattern HB shown in FIG. 6. The upward light distribution pattern HB and the low beam light distribution pattern LB are combined to form a high beam light distribution pattern suitable for illuminating the distance and above the vehicle.

The vehicle headlamp 10 may be controlled to switch between on and off using a system that combines an illuminance sensor or an environmental sensor mounted on the vehicle. Specifically, each light source may be turned off during daytime driving, and when the surroundings become dark, such as when driving in a tunnel or at night, each light source may be turned on at the discretion of the system. The system may also control switching between low beam and high beam depending on the surrounding road conditions and the driving conditions of the vehicle.

Next, the aim of the light distribution patterns of the reflector unit 20, the first reflector 21A, and the second reflector 21B will be explained using Figures 7 and 8.

Figure 7 shows the reflecting surface of the reflector unit 20 divided into four reflecting surface segments, A, B, C, and C'. Each reflecting surface segment is composed of one reflecting element or a combination of multiple reflecting elements. Figure 8 shows the subdivision of the low-beam light distribution pattern LB.

In FIG. 8, the low beam light distribution pattern LB is divided into four light distribution patterns LBA, LBB, LBC, and LBC'. In other words, the low beam light distribution pattern is formed by combining these four light distribution patterns.

Light distribution pattern LBA is a light distribution pattern that illuminates a wide area, called the vehicle front area or large diffusion area, approximately 5 to 10 m ahead of the vehicle and in both the left and right directions.

Light distribution pattern LBB is a light distribution pattern for illuminating an area approximately 20 m ahead of the vehicle, known as the medium diffusion area.

Light distribution pattern LBC and light distribution pattern LBC' are light distribution patterns for illuminating an area of approximately 40 m ahead of the vehicle, called the light collection area. The upper side of light distribution pattern LBC and light distribution pattern LBC' is also the boundary between the bright and dark areas of the low beam, called the cutoff line.

Reflective surface segment A is a reflective surface located near light source 31A and light source 31B or on the perpendicular line to each light source. The light reflected by reflective surface segment A of each reflector forms the light distribution pattern LBA in FIG. 8. In other words, reflective surface segment A is suitable for illuminating a wide area, called the vehicle front area or large diffusion area, within 5 to 10 m in front of the vehicle and in both the left and right directions.

Reflective surface segment B is a reflective surface located away from the light source in a direction lying against the normal to light source 31A. In other words, reflective surface segment B is close to light source 31A in the direction of the normal to light source 31A, and is away from light source 31A in the direction intersecting the normal to light source 31A. The normal to the light source here refers to the main irradiation direction of the light source. If the light source has a planar light-emitting part, the normal to the light source coincides with the normal to the plane that is the light-emitting part.

The light from the light source reflected by the reflective surface segment B of each reflector forms the light distribution pattern LBB shown in Figure 8. In other words, the reflective surface segment B is suitable for illuminating an area approximately 20 m ahead of the vehicle, which is called the medium diffusion area.

Reflective surface segment C is a reflective surface that is located at a distance in the counterclockwise direction of the perpendicular line of light source 31A and light source 31B. The light reflected by reflective surface segment C of each reflector forms the light distribution pattern LBC shown in Figure 8. In other words, reflective surface segment C is suitable for irradiating the horizontal cutoff line portion of the low beam.

Reflective surface segment C' is a reflective surface that is located at a distance in the clockwise direction of the perpendicular line of light source 31A and light source 31B. The light reflected by reflective surface segment C' of each reflector forms the light distribution pattern LBC' in Figure 8. In other words, reflective surface segment C' is suitable for irradiating the 15-degree cutoff line portion of the low beam.

What is important here is the distance and positional relationship between the reflective surface segments and the light source. In particular, it is desirable for reflective surface segments C and C' to be located away from the light source in the direction perpendicular to the light source. The reason for this is that, to make it easier to see distant objects, particularly strong illuminance is required near the cutoff line of the low beam light distribution pattern and near the front direction in the direction of the lamp's irradiation (line V in Figure 5). Furthermore, the area below the cutoff line must have strong illuminance, and the area above the cutoff line must be dark.

To realize such a low-beam light distribution pattern, it is necessary to form a cutoff line by arranging small light source images at the top of the low-beam light distribution pattern. A reflective element that is placed at a distance from the light source in the direction perpendicular to the light source is suitable for producing a small image. In terms of the degree of distance between the reflective element and the light source, the focal length of the reflective surface that constitutes the reflective element is preferably 50 mm or more, and more preferably the focal length is within the range of 50 mm to 60 mm.

As shown in Figure 7, in the case of the horizontally long headlamp reflector shown in this embodiment, the first reflector 21A, which has a light source located at the top or bottom of the reflector, has difficulty in securing a reflective surface segment C or C' capable of producing a narrow light source image. This is because the vertical dimensions of the reflector are small, and it is not possible to separate the reflective elements that make up the reflective surface segment from the light source.

Therefore, in this embodiment, the second light source 31B is provided to the side of the second reflector 21B, and the second reflector is made horizontally long when viewed from the front of the lamp. This makes it possible to provide a reflective surface segment with a reflective element and a light source spaced apart, even with a horizontally long reflector. As a result, it is possible to realize a vehicle headlamp with good long-distance visibility even with a horizontally long reflector.

Next, we will explain a variation of the above embodiment.

Figure 9 is a diagram similar to Figure 3, showing a reflector unit according to the first modified example.

As shown in FIG. 9, the basic configuration of this reflector unit 220 is the same as that of the reflector unit 20 of the above embodiment, but in addition to the three first reflectors 221A and the second reflector 221B provided to the right of the first reflectors 221A, a fourth reflector 221C is also provided.

In a front view of the reflector unit 220, the fourth reflector 221C is provided to the left of the first reflector 221A. In a front view of the reflector unit 220, the fourth light source 231C is arranged on the left side of the second reflector 221C. The light of the fourth light source 231C is reflected by the fourth reflector 221C and irradiated in a predetermined light distribution pattern. The fourth light source 231C is mounted on a substrate 241C. In a front view of the reflector unit 220, the substrate 241C is fixed to the left side of the reflector unit 220. Fixing means for fixing the substrate 241C to the reflector include screw fixing, lance fixing or claw fixing, and thermal caulking.

The light distribution pattern emitted by the fourth reflector 221C is the same as that of the second reflector 221B. In other words, the fourth reflector 221C is suitable for emitting the light distribution pattern LBC and the light distribution pattern LBC' shown in FIG. 8 by taking advantage of the fact that it is horizontally long like the second reflector.

Figure 10 is a view similar to Figure 3, showing a reflector unit according to the first modified example.

As shown in FIG. 10, the basic configuration of this reflector unit 320 is the same as that of the reflector unit 20 of the above embodiment, but in addition to the three first reflectors 321A and the second reflector 221B provided to the right of the first reflectors 321A, three fourth reflectors 321D are provided.

In a front view of the reflector unit 320, the fourth reflector 321D is provided below the first reflector 321A. Three pairs of the first reflector 321A and the fourth reflector 321D are arranged in parallel, one above the other. In a front view of the reflector unit 320, the fourth light source 331D is arranged on the lower surface of the fourth reflector 321D. The light of the fourth light source 331D is reflected by the fourth reflector 321D and irradiated as a predetermined light distribution pattern. The fourth light source 331D is mounted on the substrate 341D. In a front view of the reflector unit 320, the substrate 341D is fixed to the lower surface of the reflector unit 320. Fixing means for fixing the substrate 241C to the reflector include screw fixing, lance fixing or claw fixing, and thermal caulking.

The light distribution pattern emitted by the fourth reflector 321D is similar to that of the first reflector 321A. That is, the fourth reflector 321D is suitable for emitting the light distribution pattern LBA shown in FIG. 8 by utilizing a reflective surface close to the light source, similar to the first reflector 321A. Increasing the number of light sources mounted in the reflector unit 320 in this way makes it possible to increase the amount of light in the light distribution pattern.

Figure 11 is a diagram similar to Figure 3, showing a reflector unit according to the third modified example.

As shown in FIG. 11, the basic configuration of this reflector unit 420 is similar to that of the reflector unit 20 of the above embodiment, but three first reflectors 421A are arranged in the vertical direction, and a second reflector 421B is provided above the first reflectors 421A.

The light distribution pattern of this reflector unit 420 is also the low beam light distribution pattern LB shown in FIG. 8. The three first reflectors 421A irradiate the light distribution patterns LBA and LBB of the low beam light distribution pattern LB. The second reflector 421B irradiates the light distribution patterns LBC and LBC' of the low beam light distribution pattern LB. The present invention can be applied not only to horizontally long headlights, but also to vertically long headlights, and the same effects can be achieved.

The vehicle headlamp of the present invention has been described above in accordance with the embodiments, but the present invention is not limited to these embodiments, and various modifications, improvements, combinations, forms of use, etc. are possible. For example, the number of reflectors and light sources may be changed as appropriate. The reflectors may be arranged in a straight line or may be arranged in a stepped manner with differences in level. The reflector unit may have functions such as fog lamp and cornering lamp in addition to low beam and high beam.

10: Vehicle headlamp 11: Lamp housing 12: Outer cover 13: Lamp chamber 14A, 15A: Aiming screw 20, 220, 320, 420: Reflector unit 21A, 221A, 321B, 421B: First reflector 21B, 221B, 321B, 421B: Second reflector 121A: Third reflector 221C, 321D: Fourth reflector 41A, 41B, 241A, 241B, 341A, 341B, 441A, 441B: Board 141A: Board 31A, 231A, 331A, 431A: First light source 31B, 231B, 331B, 431B: Second light source 131A: Third light source LB: Low beam light distribution pattern HB: Upward light distribution pattern

Claims (7)

A vehicle headlamp comprising a first reflector 21A, a first light source 31A, a second reflector 21B, and a second light source 31B, wherein the first light source 31A is arranged such that light emitted by the first light source 31A is reflected by the first reflector, the second light source 31B is arranged such that light emitted by the second light source 31B is reflected by the second reflector, the first reflector 21A and the second reflector 21B are arranged side by side in a predetermined direction, a main direction of light emitted by the second light source 31B is the predetermined direction, the second reflector 21B has a long side in the predetermined direction when viewed from a lamp irradiation direction, and the main direction of light emitted by the first light source 31A is different from the predetermined direction. A vehicle headlamp comprising a first reflector 21A, a first light source 31A, a second reflector 21B, and a second light source 31B, wherein the first light source 31A is arranged such that light emitted from the first light source 31A is reflected by the first reflector, the second light source 31B is arranged such that light emitted from the second light source 31B is reflected by the second reflector, the first reflector 21A and the second reflector 21B are arranged side by side in a predetermined direction, a normal to a light-emitting surface of the second light source 31B is in the predetermined direction, the second reflector 21B has a long side in the predetermined direction when viewed from a lamp irradiation direction, and the normal to the light-emitting surface of the first light source 31A is different from the predetermined direction. 3. The vehicle headlamp according to claim 1, wherein a luminous flux amount of the second light source is greater than a luminous flux amount of the first light source. 3. The vehicle headlamp according to claim 1, wherein the number of the first reflectors is at least two. 3. The vehicle headlamp according to claim 1, wherein a plurality of the first light sources 31A are provided, and the first light sources 31A are mounted on a single substrate. 3. The vehicle headlamp according to claim 1, wherein the second reflector (20B) forms a cut-off line. A third light source 131A is provided in a third reflector 121A, and a low beam light distribution pattern LB is formed by at least one of the first reflectors 21A and at least one of the second reflectors 20B.
3. The vehicle headlamp according to claim 1, wherein the third light source 131A is arranged so that light emitted by the first light source 131A is reflected by the third reflector, and an upward light distribution pattern HB is formed by at least one third reflector 121A.

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