Vehicle headlights

Abstract

This prevents uneven light distribution without causing a decrease in luminous intensity in the light distribution pattern. [Solution] The system comprises a plurality of light sources arranged side by side at a distance from each other in a predetermined direction, each having a light-emitting surface; a plurality of condensing lenses that control the light emitted from each of the plurality of light sources in a convergent direction; and a projection lens that projects the light emitted from the condensing lenses, wherein the light sources are positioned between the condensing lenses and the focal point on the light source side of the condensing lenses. As a result, no unilluminated areas occur between the illumination patterns without forming lens textures or defocusing with respect to the projection lens, thus preventing the occurrence of uneven light distribution without causing a decrease in luminous intensity in the light distribution pattern.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle headlights in which light emitted from a plurality of light sources arranged side by side in a separated state is projected by a projection lens.

Background Art

[0002] There is a vehicle headlight with a variable light distribution that controls the light distribution pattern of high beams based on the situation around the vehicle.

[0003] In such a vehicle headlight with variable light distribution, a light distribution pattern based on the surrounding situation is formed by a technology called ADB (Adaptive Driving Beam). The ADB technology detects the presence of other vehicles such as oncoming vehicles and pedestrians, and performs dimming control or extinguishing control on the areas where other vehicles and pedestrians are present, suppressing the generation of dazzling light for passengers of other vehicles and pedestrians, etc., and aiming to improve safety.

[0004] In a vehicle headlight using ADB technology, a plurality of light sources are arranged side by side at a certain interval in a predetermined direction, for example, in the left - right direction, and the on - off state of light for each light source is controlled based on the detection result with respect to other vehicles and pedestrians, etc.

[0005] Generally, light - emitting diodes (LEDs) are used as light sources. When light is emitted from each light source, an irradiation pattern is formed by the emitted light, and a light distribution pattern is formed as an aggregate of irradiation patterns.

[0006] For example, in a vehicle headlight in which lighting control and extinguishing control are performed, light is irradiated to the area corresponding to the light source under lighting control to form an irradiation pattern, but no light is irradiated to the area corresponding to the light source under extinguishing control, that is, the area where other vehicles and pedestrians are detected, and no irradiation pattern is formed.

[0007] Incidentally, since light sources generate heat when emitting light, and this heat can cause the operating state to become unstable, as described above, by creating gaps between adjacent light sources and arranging multiple light sources at regular intervals, the influence of heat generated by other light sources is suppressed.

[0008] However, because multiple light sources are arranged at regular intervals, for example, when light is emitted simultaneously from adjacent light sources, unilluminated areas may occur between adjacent illumination patterns formed by the emitted light, resulting in uneven light distribution and potentially preventing the formation of a proper light distribution pattern.

[0009] Therefore, in variable-beam headlights for vehicles, for example, a diffusion lens element such as a lens texture is formed on the surface of the projection lens (see, for example, Patent Document 1), or the projection lens is defocused to "blur" the illumination pattern, thereby overlapping the edges of the illumination pattern and preventing the occurrence of unilluminated areas between the illumination patterns. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2019-133842 [Overview of the project] [Problems that the invention aims to solve]

[0011] However, in a configuration that prevents the occurrence of unilluminated areas between illumination patterns by "blurring" the illumination pattern as described above, while the occurrence of unilluminated areas between illumination patterns is prevented, the "blurring" of the illumination pattern results in a decrease in brightness per unit area, either partially or overall, leading to a decrease in luminous intensity in the light distribution pattern.

[0012] Therefore, the present invention aims to prevent the occurrence of uneven light distribution without causing a decrease in luminous intensity in the light distribution pattern. [Means for solving the problem]

[0013] The vehicle headlight according to the present invention comprises a plurality of light sources arranged side by side at a distance from each other in a predetermined direction, each having a light-emitting surface; a plurality of condensing lenses that control the light emitted from each of the plurality of light sources in a converging direction; and a projection lens that projects the light emitted from the condensing lenses, wherein the light sources are positioned between the condensing lenses and the focal point on the light source side of the condensing lenses.

[0014] This prevents the formation of lens textures or defocusing of the projection lens, and ensures that no unilluminated areas occur between the illumination patterns. [Effects of the Invention]

[0015] According to the present invention, since no unilluminated areas occur between illumination patterns without forming lens textures or defocusing the projection lens, it is possible to prevent uneven light distribution without causing a decrease in luminous intensity in the light distribution pattern. [Brief explanation of the drawing]

[0016] [Figure 1] Figures 2 to 5 illustrate an embodiment of the vehicle headlight of the present invention, and this figure is a plan view of the vehicle headlight, partially shown in cross-section. [Figure 2] This is a conceptual diagram showing the optical path in a high-beam unit. [Figure 3] This is a conceptual diagram showing the lengths of each part. [Figure 4] This is a schematic diagram showing a light distribution pattern formed when parts of the irradiation pattern overlap. [Figure 5] This is a schematic diagram showing the light distribution pattern formed when the irradiation patterns do not overlap. [Modes for carrying out the invention]

[0017] Hereinafter, embodiments for implementing the headlamp for a vehicle of the present invention will be described with reference to the accompanying drawings.

[0018] The headlamp 1 for a vehicle is respectively attached and arranged at both left and right ends of the vehicle body. The vehicle to which the headlamp 1 for a vehicle is assembled is provided with a sensor (not shown) for detecting the presence of other vehicles such as a preceding vehicle or an oncoming vehicle, or pedestrians. Incidentally, the sensor may be provided on the headlamp 1 for a vehicle.

[0019] The headlamp 1 for a vehicle has a lamp housing 2 having an opening at the front end and a cover 3 closing the opening of the lamp housing 2 (see FIG. 1). The lamp housing 2 and the cover 3 constitute a lamp outer casing 4, and the internal space of the lamp outer casing 4 is formed as a lamp chamber 5.

[0020] In the lamp chamber 5, a low beam unit 6 for irradiating light in a short-distance area and a high beam unit 7 for irradiating light in a long-distance area are arranged. The low beam unit 6 is provided with, for example, a reflector for reflecting light and a reflection optical system in which the light is irradiated to the outside as reflected light. The high beam unit 7 is provided with a direct irradiation optical system in which the light is irradiated to the outside as direct light without having a reflector or the like for reflecting light.

[0021] The low beam unit 6 is provided, for example, as a PES (Projector Ellipsoid System) type lamp unit, and has a holder 8, a reflector 9, a projection lens 10, a light emitter 11, and a shade 12.

[0022] The holder 8 has, for example, a mounting section 8a provided as a base portion and a lens mounting section 8b protruding upward from the front end of the mounting section 8a. The reflector 9 is formed in a shape that opens forward and downward, with its inner surface formed as a reflective surface, and is attached to the mounting section 8a. The projection lens 10 is held by the lens mounting section 8b and has the function of projecting light in a parallel or substantially parallel manner. The light-emitting element 11 is mounted on the upper surface of a mounting substrate (not shown), and the mounting substrate is placed on the upper surface of the mounting section 8a, covered by the reflector 9. As the light-emitting element 11, for example, a light-emitting diode (LED) is used. The shade 12 is attached to the mounting section 8a between the reflector 9 and the projection lens 10 and has the function of forming a cutoff line. The shade 12 may be formed integrally with the holder 8.

[0023] When light is emitted from the light-emitting element 11 in the low beam unit 6, the emitted light is reflected by the reflective surface of the reflector 9 toward the projection lens 10, where it is converted into parallel or nearly parallel light by the projection lens 10, passed through the cover 3, and irradiated forward. At this time, a portion of the light reflected by the reflector 9 is blocked by the shade 12, forming a cutoff line.

[0024] The high beam unit 7 includes a heat sink 13, a substrate 14, multiple light sources 15, a lens holder 16, multiple focusing lenses 17, and a projection lens 18 (see Figures 1 and 2), and is provided as a lighting unit using ADB technology.

[0025] The high beam unit 7 is a variable-beam unit whose light distribution pattern is controlled based on the surrounding conditions of the vehicle. The high beam unit 7 uses ADB technology to perform dimming or turning off the lights in areas where other vehicles or pedestrians are detected.

[0026] The heat sink 13 is formed, for example, in a horizontally elongated shape and is made of a metal material with high heat dissipation properties. The front surface of the heat sink 13 is formed as a mounting surface 13a.

[0027] The substrate 14 is formed, for example, in a horizontally elongated shape, and is attached to the mounting surface 13a, excluding the left and right ends, with its thickness direction oriented in the front-to-back direction.

[0028] Light-emitting diodes (LEDs) are used as the light source 15, and the front surface is a light-emitting surface 15a. The light sources 15 are mounted on the front of the substrate 14, for example, spaced apart to the left and right, and are individually controlled to turn on and off by a control unit (not shown). The control unit receives detection results regarding the presence of other vehicles or pedestrians from sensors provided in the vehicle or vehicle headlight 1, and the control unit performs on / off control for each light source 15 based on the input detection results. The number of light sources 15 can be arbitrary as long as there are multiple, and for example, they may be mounted in a matrix arrangement spaced apart in the left-right and up-down directions.

[0029] The lens holder 16 may be formed by integrally forming each part (see Figure 1). However, the lens holder 16 may also be composed of multiple members joined together.

[0030] The lens holder 16 includes, for example, a first holding portion 16a formed in a shape extending to the left and right, a second holding portion 16b formed in a shape extending to the left and right and located in front of the first holding portion 16a, a pair of vertical wall portions 16c provided spaced apart to the left and right, and a pair of mounting protrusions 16d projecting in directions away from each other from the rear ends of the vertical wall portions 16c. The left and right ends of the first holding portion 16a and the second holding portion 16b are each continuous with the pair of vertical wall portions 16c, and the second holding portion 16b is continuous with the front end of the vertical wall portion 16c.

[0031] The same number of condensing lenses 17 as the number of light sources 15 are provided and are held in the first holding part 16a, spaced apart to the left and right. When held in the first holding part 16a, each condensing lens 17 is positioned directly in front of the light source 15. The condensing lenses 17 have the function of controlling the light emitted from the light source 15 in the convergence direction (concentration direction).

[0032] The projection lens 18 is held by the second holding part 16b. While held by the second holding part 16b, the projection lens 18 is positioned in front of the plurality of condensing lenses 17. The projection lens 18 has the function of projecting the light emitted from the condensing lenses 17 in a parallel or substantially parallel manner.

[0033] In the high beam unit 7, a plurality of plate-shaped partitions 19 are arranged spaced apart to the left and right between the substrate 14 and the first holding portion 16a. The partitions 19 are located between adjacent light sources 15 and have the function of preventing light emitted from the light sources 15 from entering the space between the adjacent light sources 15 and the focusing lens 17.

[0034] In the high-beam unit 7 configured as described above, the light source 15, the condensing lens 17, and the projection lens 18 are arranged in order from rear to front, with the light source 15 positioned between the focal point F1 on the light source 15 side (rear side) of the condensing lens 17 and the condensing lens 17 (see Figure 2). Therefore, when light is emitted from the light source 15, a virtual image 20 of the light source 15 is formed behind the focal point F1. Figure 2 shows an example configuration in which three light sources 15 and three condensing lenses 17 are provided in order to simplify the explanation of the functions of the high-beam unit 7.

[0035] In the high-beam unit 7, multiple light sources 15 are arranged spaced apart to the left and right. Each light source 15 is equipped with multiple condensing lenses 17 that control the light emitted from each light source 15 in a convergence direction (light-gathering direction), and a projection lens 18 that projects the light emitted from the multiple condensing lenses 17. The optical axis J of one light source 15 coincides with the central axis M1 of one condensing lens 17 and the central axis M2 of the projection lens 18. For example, the optical axis J of a light source 15 located in the center of the left and right coincides with the central axis M1 of a condensing lens 17 located in the center of the left and right and the central axis M2 of the projection lens 18.

[0036] Furthermore, when an even number of light sources 15 and condensing lenses 17 are arranged, it is desirable that the optical axis J of one of the light sources 15 located in the center on the left and right coincides with the central axis M1 of one of the condensing lenses 17 located in the center on the left and the central axis M2 of the projection lens 18. For example, when four light sources 15 and four condensing lenses 17 are arranged, it is desirable that the optical axis J of the second light source 15 from the left coincides with the central axis M1 of the second condensing lens 17 from the left, or that the optical axis J of the third light source 15 from the left coincides with the central axis M1 of the third condensing lens 17 from the left.

[0037] Furthermore, in the high-beam unit 7, as described above, when light is emitted from the light source 15, a virtual image 20 of the light source 15 is formed behind the focal point F1. It is desirable that the focal point F2 of the projection lens 18 coincides with the position where the virtual image 20 is formed.

[0038] When light is emitted from the light-emitting surface 15a of the light source 15 in the high-beam unit 7, the emitted light is controlled in the direction of convergence by the focusing lens 17. At this time, since the light source 15 is located between the focal point F1 of the focusing lens 17 and the focusing lens 17, a virtual image 20 of the light source 15 (light-emitting surface 15a) is formed behind the focal point F1, and the formed virtual image 20 is projected by the projection lens 18.

[0039] In this case, the light source 15, which is located outside the center on the left and right sides, does not have its optical axis J aligned with the central axis M2 of the projection lens 18. However, because the light is controlled in the direction of convergence by the condensing lens 17, most of the light emitted from the light source 15 enters the projection lens 18, and the formed virtual image 20 is projected by the projection lens 18.

[0040] In the high beam unit 7, if the distance between the light-emitting surfaces 15a of adjacent light sources 15 is defined as the distance between light-emitting surfaces L1, and the length of the light-emitting surfaces 15a in the direction in which the light sources 15 are aligned is defined as the length of the light-emitting surface L2, then the size S of the virtual image 20 in the direction in which it is aligned is set to be greater than or equal to the sum of the distance between light-emitting surfaces L1 and the length of the light-emitting surface L2 (see Figure 3).

[0041] Therefore, each irradiation pattern P of light emitted from the light source 15 and projected by the projection lens 18 is projected in a manner that easily overlaps in the direction in which the multiple light sources 15 are arranged (see Figure 4). As a result, no gaps are created between each irradiation pattern P of light, and an appropriate light distribution pattern Q can be formed by the light emitted from the high beam unit 7.

[0042] Furthermore, in the high beam unit 7, it is also possible to configure it so that the size S of the virtual images 20 in the direction of alignment is equal to the sum of the distance L1 between light-emitting surfaces and the length L2 of the light-emitting surfaces.

[0043] In this way, the size of the virtual image 20 matches the sum of the distance L1 between light-emitting surfaces and the length L2 of the light-emitting surface, so that the illumination patterns P do not overlap and are projected in a state where the illumination patterns P are aligned without gaps in the direction in which the multiple light sources 15 are arranged (see Figure 5). As a result, in the light distribution pattern Q formed by each illumination pattern P, there are no overlapping regions that tend to have higher brightness than other regions, so that an appropriate and uniformly luminous-intensity light distribution pattern Q can be formed by the light emitted from the high-beam unit 7.

[0044] As described above, the vehicle headlight 1 is provided with a plurality of light sources 15, each having a light-emitting surface 15a, a plurality of condensing lenses 17 that control the light emitted from each of the plurality of light sources 15 in the convergence direction, and a projection lens 18 that projects the light emitted from the condensing lenses 17, with the light sources 15 positioned between the condensing lenses 17 and the focal point F1 on the light source 15 side of the condensing lenses 17.

[0045] Therefore, since no unilluminated areas occur between adjacent illumination patterns P without forming lens textures or defocusing the projection lens, it is possible to prevent uneven light distribution without causing a decrease in luminous intensity in the light distribution pattern Q.

[0046] Furthermore, since the focal point F2 on the light source 15 side of the projection lens 18 coincides with the position where the virtual image 20 is formed, the virtual image 20 formed at the position coincided with the focal point F2 of the projection lens 18 is projected by the projection lens 18, thereby forming a clear light distribution pattern Q.

[0047] Furthermore, since the optical axis J of one light source 15 coincides with the central axis M1 of one condensing lens 17 and the central axis M2 of the projection lens 18, the optical axis J of one light source 15 is not tilted with respect to the central axis M1 of the condensing lens 17 and the central axis M2 of the projection lens 18, thereby improving the brightness of the light irradiated toward the outside of the vehicle. [Explanation of symbols]

[0048] 1. Vehicle headlights 15 light source 15a Light-emitting surface 17. Focusing lens 18 Projection lens 20 Illusion

Claims

1. Multiple light sources, each having a light-emitting surface, are arranged side by side at a distance from each other in a predetermined direction. Multiple focusing lenses that control the direction of convergence of light emitted from each of the multiple light sources, The system comprises a projection lens that projects light emitted from the aforementioned focusing lens, The light source is positioned between the condensing lens and the focal point on the light source side of the condensing lens. Vehicle headlights.

2. When light is emitted from the light source, a virtual image of the light source is formed. The distance between the light-emitting surfaces of adjacent light sources is defined as the distance between light-emitting surfaces. The length of the light-emitting surface in the direction in which the multiple light sources are arranged is defined as the light-emitting surface length. The size of the virtual image in the direction in which the light sources are aligned is set to be greater than or equal to the sum of the distance between the light-emitting surfaces and the length of the light-emitting surfaces. The vehicle headlight according to claim 1.

3. The size of the virtual image was equal to the sum of the distance between the light-emitting surfaces and the length of the light-emitting surface. The vehicle headlight according to claim 2.

4. The focal point on the light source side of the projection lens coincides with the position where the virtual image is formed. A vehicle headlight according to claim 2 or claim 3.

5. The optical axis of one of the light sources coincides with the central axis of one of the focusing lenses and the central axis of the projection lens. A vehicle headlight according to claim 1, claim 2, or claim 3.

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