Vehicle lighting

Abstract

A vehicle lamp (10) comprises: a projection lens (12); a low-beam LED (18a) and a high-beam LED (18b), which are arranged at or near a rear focus F of the projection lens (12); a daytime running LED (18c); and a light guide (22), which comprises an incident portion (22a) for incident light from the daytime running LED (18c), a light guide portion (22b) for guiding the incident light, and a first emission portion (22d) for emitting the guided light. The first emission portion (22d) of the light guide (22) is arranged at or near the rear focus F of the projection lens (12).

Description

Technical Field

[0001] The invention relates to a vehicle lamp. Background Art

[0002] In the past, vehicle lamps using light emitting diodes (hereinafter referred to as "LEDs") and other light emitting elements have been developed (for example, see Patent Document 1). In addition, when using a light emitting element as a light source for a vehicle headlamp, it is difficult to obtain a desired light quantity and shape of a light distribution pattern with a single light emitting element, so a vehicle lamp having a plurality of light emitting elements arranged on a substrate has been proposed (for example, see Patent Document 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-95480

[0006] Patent Document 2: Japanese Patent Application Publication No. 2016-149373 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In a vehicle lamp using a plurality of light emitting elements, if some light emitting elements are arranged near the focal point of a projection lens, other light emitting elements cannot be arranged near the focal point of the projection lens, and it may be difficult to obtain a desired light distribution pattern.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technology for forming a desired light distribution pattern in a vehicle lamp using a plurality of light emitting elements even when some of the light emitting elements cannot be arranged near the focal point of a projection lens.

[0010] Means used to solve problems

[0011] In order to solve the above-mentioned problem, a vehicle lamp according to one embodiment of the present invention comprises: a projection lens; a first light emitting element arranged at or near the focus of the projection lens; a second light emitting element; and a light guide having an incident portion for incident light from the second light emitting element, a light guide portion for guiding the incident light, and an emission portion for emitting the guided light. The emission portion of the light guide is arranged at or near the focus of the projection lens.

[0012] In the vehicle lamp of the above aspect, the first light emitting element and the second light emitting element may be arranged on the same substrate.

[0013] In the vehicle lamp of the above aspect, the light guide may include a second emission portion for emitting incident light. The vehicle lamp may further include a reflector for reflecting the light emitted from the second emission portion toward the projection lens.

[0014] In the vehicle lamp of the above aspect, the first light emitting element may include a low beam light emitting element and a high beam light emitting element, and the second light emitting element may include a daytime running light emitting element.

[0015] In the vehicle lamp of the above embodiment, the light emitted from the emission portion of the light guide may be irradiated toward an area above the low beam light distribution pattern and the high beam light distribution pattern, and the light emitted from the second emission portion of the light guide may be irradiated toward a substantially central area of ​​the low beam light distribution pattern.

[0016] Another embodiment of the present invention is also a vehicle lamp. The vehicle lamp comprises: a substrate; an array of first light-emitting elements for a first light distribution pattern; an array of second light-emitting elements for illuminating a second light distribution pattern that is closer to the front side of the vehicle than the first light distribution pattern; a third light-emitting element for adding a light distribution pattern; and a projection lens. The array of first light-emitting elements, the array of second light-emitting elements, and the third light-emitting element are mounted on the same substrate. Light emitted from the array of first light-emitting elements, the array of second light-emitting elements, and the third light-emitting element is irradiated toward the front of the lamp via the same projection lens. By lighting the array of first light-emitting elements, the array of second light-emitting elements, and the third light-emitting element at the same time, a third light distribution pattern that is wider than the first light distribution pattern and the second light distribution pattern and has a lower luminosity is formed.

[0017] In the vehicle lamp of the above aspect, the substrate may be arranged to be inclined with respect to a plane perpendicular to the optical axis of the projection lens.

[0018] The vehicle lamp of the above aspect may further include a light guide having an incident portion for incident light from the third light emitting element, a light guide portion for guiding the incident light, and an emission portion for emitting the guided light. The emission portion of the light guide may be arranged at or near the focus of the projection lens.

[0019] In the vehicle lamp of the above-mentioned manner, the array of first light-emitting elements and the array of second light-emitting elements are arranged at the focus of the projection lens or near it, the array of first light-emitting elements is constructed to be able to be individually lit and extinguished with the help of a wiring pattern formed on the substrate, and the third light-emitting element can be arranged to be separated from the first light-emitting element via the wiring pattern.

[0020] The vehicle lamp of the above aspect may further include a light shielding cover arranged to cover the light guide. The light shielding cover may be made of metal.

[0021] Effects of the Invention

[0022] According to the present invention, in a vehicle lamp using a plurality of light emitting elements, even when some of the light emitting elements cannot be arranged near the focal point of the projection lens, a desired light distribution pattern can be formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a perspective view of a vehicle lamp according to an embodiment of the present invention.

[0024] Figure 2 It is the front view of the vehicle lamp.

[0025] Figure 3 It is a side view of a vehicle lamp.

[0026] Figure 4 It is an exploded perspective view of a vehicle lamp.

[0027] Figure 5 This is a schematic top view of the substrate.

[0028] Figure 6 It is a diagram for explaining the main part of the vehicle lamp according to the embodiment of the present invention.

[0029] Figure 7 yes Figure 2 A schematic AA cross-sectional view of the vehicle lamp is shown.

[0030] Figure 8 This is a diagram for explaining a light distribution pattern formed on a virtual vertical screen.

[0031] Fig. 9 It is a three-dimensional diagram showing a light guide.

[0032] Fig.10 It is a three-dimensional diagram showing a light guide.

[0033] Fig.11 It is a three-dimensional diagram showing a light guide. DETAILED DESCRIPTION

[0034] Hereinafter, the mode for implementing the present invention will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are given to the same elements in the description of the drawings, and repeated descriptions are appropriately omitted. In addition, in this specification, when terms indicating directions such as "up", "down", "front", "rear", "left", "right", "inside", and "outside" are used, they refer to directions in the posture when the vehicle lamp is installed on the vehicle.

[0035] Figure 1 It is a perspective view of a vehicle lamp 10 according to an embodiment of the present invention. Figure 2 It is a front view of the vehicle lamp 10 . Figure 3It is a side view of the vehicle lamp 10 . Figure 4 1 is an exploded perspective view of the vehicle lamp 10. The vehicle lamp 10 is disposed at both left and right ends of the front portion of the vehicle body, and functions as a headlamp.

[0036] The vehicle lamp 10 is configured to form a high-beam light distribution pattern and a low-beam light distribution pattern that is irradiated at a position closer to the front side of the vehicle than the high-beam light distribution pattern. In addition, the vehicle lamp 10 is configured to form an ADB (Adaptive Driving Beam) light distribution pattern that dynamically and adaptively controls the high-beam light distribution pattern based on the state of the vehicle's surroundings. Further, the vehicle lamp 10 is configured to form an additional light distribution pattern. In the vehicle lamp 10 involved in the present embodiment, a daytime running light distribution pattern that is wider than the high-beam light distribution pattern and the low-beam light distribution pattern is formed by synthesizing the high-beam light distribution pattern, the low-beam light distribution pattern, and the additional light distribution pattern. In addition, when forming the daytime running light distribution pattern, the high-beam light source is dimmed to one percent of the normal state (i.e., when the high-beam light distribution pattern is formed), and the low-beam light source is dimmed to a few tenths of the normal state (i.e., when the low-beam light distribution pattern is formed).

[0037] The vehicle lamp 10 is a so-called direct-type lamp. The vehicle lamp 10 includes a projection lens 12, a lens holder 14 for holding the projection lens 12, a substrate 16, a plurality of LEDs 18 arranged on the substrate, a connector 19 for supplying power to the LEDs 18, a reflector 20, a light guide 22, a heat sink 24 for dissipating heat generated by the LEDs 18, a fan 26 for forcibly cooling the heat sink 24, a fan cover 28 covering the fan 26, and a light shield 32.

[0038] Figure 5 1 is a schematic top view of the substrate 16. The substrate 16 is arranged on a substrate mounting surface 24a (see Figure 4 ) Figure 5As shown, a plurality of low-beam LEDs 18a are arranged in an array on the upper part of the substrate 16. In addition, a plurality of high-beam LEDs 18b are arranged in an array slightly below the low-beam LEDs 18a. In addition, two daytime running LEDs 18c are arranged at a large interval below the high-beam LEDs 18b. In this way, the array of low-beam LEDs 18a, the array of high-beam LEDs 18b, and the daytime running LEDs 18c are mounted on the same substrate 16. A connector 19 for supplying power to the low-beam LEDs 18a, the high-beam LEDs 18b, and the daytime running LEDs 18c is arranged at the lower part of the substrate 16. The high-beam LEDs 18b and the daytime running LEDs 18c are separated because the wiring pattern 17 from the connector 19 to the high-beam LEDs 18b is sandwiched in between. In order to perform ADB control, the high-beam LEDs 18b can be turned on and off individually. Therefore, the array-shaped high-beam LEDs 18b are connected in parallel, and it is necessary to expand the formation area of ​​the wiring pattern 17. Because the wiring pattern 17 used for the high-beam LEDs 18b does not allow the daytime running LEDs 18c to be arranged near the high-beam LEDs 18b. On the other hand, the array-shaped low-beam LEDs 18a are connected in series because they are not individually lit and extinguished.

[0039] In another embodiment, a switch IC can be arranged in the middle of the wiring pattern 17 connecting the low-beam LED 18a and the high-beam LED 18b and the connector 19. The switch IC controls the luminous intensity of the low-beam LED 18a and the high-beam LED 18b by PWM (Pulse Width Modulation) control. As a method of dimming the low-beam LED 18a and the high-beam LED 18b, although the driving current can also be reduced, there is a possibility of luminous color deviation due to the misalignment of the luminous wavelength of the LED. On the other hand, in the method using PWM control, the dislocation of the luminous wavelength of the LED can be made smaller by controlling the duty cycle to dim the light. The switch IC needs to be arranged as close to the high-beam LED 18b as possible. This is because, when the high-beam LED 18b is dimmed to one percent of the normal level, the duty cycle becomes one percent of the normal level, which is very short. Therefore, in such another embodiment, it is difficult to further arrange the daytime running LED 18c near the high-beam LED 18b.

[0040] Figure 6 1 is a diagram for explaining the main part of the vehicle lamp 10 according to the embodiment of the present invention. Figure 6 In the embodiment, the projection lens 12, the lens holder 14, the light shielding cover 32 and other components are removed. Figure 7 yes Figure 2 The vehicle lamp 10 is schematically shown in cross-sectional view taken along the line AA.

[0041] like Figure 7 As shown in FIG. 1 , the low-beam LED 18a and the high-beam LED 18b are arranged at or near the rear focus F of the projection lens 12. Therefore, the image on the focal plane including the rear focus F formed by the light emitted from the low-beam LED 18a and the high-beam LED 18b is projected in front of the lamp as an inverted image through the projection lens 12. Figure 6 As shown in FIG. 1 , a beam shaper 30 is disposed between the low-beam LED 18a and the high-beam LED 18b. The beam shaper 30 blocks a portion of the light emitted from the low-beam LED 18a to form a cutoff line of the low-beam light distribution pattern. Figure 7 , light L1 emitted from the low-beam LED 18 a and light L2 emitted from the high-beam LED 18 b are shown.

[0042] like Figure 7 As shown in FIG. 1 , in the present embodiment, the substrate 16 is arranged to be inclined relative to a plane perpendicular to the optical axis Ax of the projection lens 12. Thus, the high-beam LED 18b is located closer to the projection lens 12 than the low-beam LED 18a. Thus, since the high-beam LED 18b can be closer to the rear focus F of the projection lens 12 than when the substrate 16 is arranged perpendicular to the optical axis Ax of the projection lens 12 without being inclined, the luminosity of the high-beam light distribution pattern can be improved. In addition, when the substrate 16 is arranged in this way, since the low-beam LED 18a is farther from the rear focus F of the projection lens 12 than when the substrate 16 is arranged perpendicular to the optical axis Ax of the projection lens 12 without being inclined, the luminosity of the low-beam light distribution pattern is reduced, but since the low-beam light distribution pattern is not required to have a high luminosity as the high-beam light distribution pattern, there is no problem. In addition, since the cut-off line of the low-beam light distribution pattern is formed by the beam shaper 30, there is no problem with the shape of the low-beam light distribution pattern.

[0043] Figure 8It is a figure for explaining the light distribution pattern formed on the virtual vertical screen arranged at a position of 25m in front of the vehicle. The light L1 emitted from the low beam LED 18a is projected by the projection lens 12, thereby forming the low beam light distribution pattern Lo on the virtual vertical screen. In addition, the light L2 emitted from the high beam LED 18b is projected by the projection lens 12, thereby forming the high beam light distribution pattern Hi on the virtual vertical screen. Here, when considering the case where the low beam light distribution pattern Lo and the high beam light distribution pattern Hi are synthesized on the basis of light reduction to form the daytime running light distribution pattern DR, there is a possibility that the light amount of the area AR1 above the low beam light distribution pattern Lo and the high beam light distribution pattern Hi and the approximately central area AR2 of the low beam light distribution pattern Lo is insufficient relative to the value prescribed by the law. Therefore, in the present embodiment, the first additional light distribution pattern AD1 filling the area AR1 and the second additional light distribution pattern AD2 filling the area AR2 are formed by the daytime running LED 18c.

[0044] In order to form a desired additional light distribution pattern, it is desirable that the daytime running LED 18c is arranged near the rear focus F like the low beam LED 18a and the high beam LED 18b. However, in reality, due to the existence of the wiring pattern 17 of the high beam LED 18b as described above, it cannot be arranged near the rear focus F. Therefore, in the vehicle lamp 10 according to the present embodiment, the first additional light distribution pattern AD1 and the second additional light distribution pattern AD2 are formed by the light guide 22.

[0045] Fig. 9 , Fig.10 as well as Fig.11 2 is a perspective view showing the light guide 22. The light guide 22 has an incident portion 22a, a light guiding portion 22b, a reflecting portion 22c, a first emitting portion 22d, and a second emitting portion 22e.

[0046] The incident portion 22a is arranged above the daytime running LED 18c so that the light from the daytime running LED 18c is incident inward. A Fresnel step is formed in the incident portion 22a for making the light from the daytime running LED 18c parallel light. The reflecting portion 22c reflects the light incident inward from the incident portion 22a. The reflecting portion 22c is composed of a plurality of reflecting surfaces. The light guide portion 22b is a roughly plate-shaped light guide plate that guides a portion of the light reflected by the reflecting portion 22c. The first emitting portion 22d is provided at the front end portion of the light guide portion 22b so that the light guided in the light guide portion 22b is emitted to the outside. A step is formed in the first emitting portion 22d for refracting the light guided in the light guide portion 22b and emitting it in a predetermined direction to the outside. The second emitting portion 22e is provided near the reflecting portion 22c so that a portion of the light reflected by the reflecting portion 22c is emitted to the outside.

[0047] like Figure 7 As shown, in the vehicle lamp 10 involved in this embodiment, the first emission portion 22d of the light guide 22 is arranged at the rear focus F of the projection lens 12 or in the vicinity thereof. In this way, by arranging the first emission portion 22d at the rear focus F of the projection lens 12 or in the vicinity thereof, the same effect as when the daytime running LED 18c is arranged at the rear focus F or in the vicinity thereof is obtained. The light guide 22 can be regarded as a virtual light source. The light L3 emitted from the first emission portion 22d of the light guide 22 is projected by the projection lens 12, thereby forming a first additional light distribution pattern AD1 on a virtual vertical screen in front of the lamp.

[0048] In addition, if Figure 7 As shown, in the vehicle lamp 10 according to the present embodiment, the light L4 emitted from the second emission portion 22e of the light guide 22 is reflected by the reflector 20 located on the opposite side of the light guide 22 across the low-beam LED 18a and the high-beam LED 18b. Then, the light L4 emitted from the second emission portion 22e of the light guide 22 is projected by the projection lens 12, thereby forming a second additional light distribution pattern AD2 on a virtual vertical screen in front of the lamp.

[0049] like Figure 8 As shown, by lighting up the array of low-beam LEDs 18a, the array of high-beam LEDs 18b, and the daytime running LEDs 18c at the same time, the low-beam light distribution pattern Lo, the high-beam light distribution pattern Hi, the first additional light distribution pattern AD1, and the second additional light distribution pattern AD2 are synthesized to form a daytime running light distribution pattern DR. In this way, in the vehicle lamp 10 according to the present embodiment, by using the light guide 22, even when the daytime running LEDs 18c cannot be arranged around the rear focus F of the projection lens 12, a desired light distribution pattern can be formed.

[0050] Back to Figure 7 The shading hood 32 is configured to cover a portion of the light guide 22 (the incident portion 22a, the reflecting portion 22c, and the second emitting portion 22e). The shading hood 32 shields the leaked light from the light guide 22. This prevents glare from entering the projection lens 12. In addition, the shading hood 32 shields the sunlight focused by the projection lens 12. This prevents the light guide 22 from being deformed or other undesirable conditions due to excessive focusing of sunlight. In order to properly shield the sunlight, the shading hood 32 is preferably made of metal.

[0051] For example, in the above-mentioned Patent Document 1, a vehicle headlamp is composed of a plurality of lamp units of a focusing type and a diffusion type, which are composed of a reflector and a lens and use LEDs as light sources, and all or a selected part of these lamp units are lit, and the light emitted from the lit lamp units is synthesized to obtain a desired light distribution pattern. In particular, a high-beam light distribution pattern is obtained by lighting a lamp unit with a higher focusing property, and a low-beam light distribution pattern is obtained by lighting a lamp unit with a higher diffusion property.

[0052] In recent years, in addition to the high-beam and low-beam light distribution patterns, light distribution patterns suitable for the driving state of the vehicle have been proposed, such as daytime running light distribution patterns for allowing other vehicles to recognize the presence of the vehicle during daytime driving.

[0053] In order to cope with such various light distribution patterns, a plurality of lamp units constituting a vehicle headlamp are configured as lamp units having different light distribution characteristics, and then these lamp units are combined to form a light distribution pattern. Therefore, in order to realize a light distribution pattern for daytime running vehicles in addition to a light distribution pattern for high beam and a light distribution pattern for low beam, it is necessary to add lamp units having different light distribution characteristics. As the number of lamp units increases, there is a problem that the vehicle headlamp becomes larger and the cost becomes higher.

[0054] Therefore, it is desirable to provide a vehicle lamp that can form a plurality of light distribution patterns using a relatively small number of components.

[0055] In the vehicle lamp 10 involved in this embodiment, an array of low-beam LEDs 18a, an array of high-beam LEDs 18b, and daytime running LEDs 18c are mounted on the same substrate 16. In addition, light emitted from the array of low-beam LEDs 18a, the array of high-beam LEDs 18b, and the daytime running LEDs 18c is irradiated toward the front of the lamp via the same projection lens 12. Three light distribution patterns, namely, a high-beam light distribution pattern Hi, a low-beam light distribution pattern Lo, and a daytime running light distribution pattern DR, can be formed with fewer components than when a plurality of lamp units are used. As a result, the vehicle lamp can be miniaturized and cost-effective compared to the case of using a plurality of lamp units.

[0056] The present invention has been described above based on the embodiments. These embodiments are illustrative only, and those skilled in the art will appreciate that various modifications may be made to the combination of each component and each process, and such modifications are also within the scope of the present invention.

[0057] For example, in the above-mentioned embodiment, the LED is exemplified as the light emitting element, but the light emitting element is not limited to the LED, and for example, a semiconductor laser may also be used.

[0058] The present invention can be used for a vehicle lamp.

[0059] Description of Reference Numerals

[0060] 10: vehicle lamp; 12: projection lens; 14: lens holder; 16: substrate; 18: LED; 19: connector; 20: reflector; 22: light guide; 24: heat sink; 26: fan; 30: beam shaper; 32: light shield.

Claims

1. A vehicle lamp, characterized in that: The vehicle lamp comprises: Projection lens; A first light emitting element, which is arranged at or near the focus of the projection lens; a second light emitting element; a light guide having an incident portion for incident light from the second light emitting element, a light guiding portion for guiding the incident light, a first emitting portion for emitting the guided light, and a second emitting portion for emitting the incident light; as well as a reflector that reflects the light emitted from the second emission portion toward the projection lens, The first emission portion of the light guide is arranged at a focal point of the projection lens or in the vicinity thereof.

2. The vehicle lamp according to claim 1, characterized in that: The first light emitting element and the second light emitting element are arranged on the same substrate.

3. The vehicle lamp according to claim 1, characterized in that: The first light emitting element includes a low beam light emitting element and a high beam light emitting element. The second light emitting element includes a daytime running light emitting element.

4. The vehicle lamp according to claim 3, characterized in that: The light emitted from the first emission portion of the light guide is irradiated toward a region above the low-beam light distribution pattern and the high-beam light distribution pattern. The light emitted from the second emission portion of the light guide is irradiated toward a central area of ​​the low-beam light distribution pattern.

5. A vehicle lamp, characterized in that: The vehicle lamp comprises: substrate; an array of first light emitting elements for a first light distribution pattern; an array of second light emitting elements for illuminating a second light distribution pattern at a position near the front side of the vehicle in contrast to the first light distribution pattern; A third light emitting element, which is used to add a light distribution pattern; a light guide having an incident portion for incident light from the third light emitting element, a light guiding portion for guiding the incident light, and an emitting portion for emitting the guided light; as well as Projection lens, The array of the first light emitting elements, the array of the second light emitting elements and the third light emitting elements are mounted on the same substrate, The light emitted from the first light emitting element array, the second light emitting element array, and the third light emitting element is irradiated toward the front of the lamp through the same projection lens. By lighting up the first light emitting element array, the second light emitting element array, and the third light emitting element at the same time, a third light distribution pattern is formed which is wider than the first light distribution pattern and the second light distribution pattern and has a lower luminance. The emitting portion of the light guide is arranged at the focal point of the projection lens or in the vicinity thereof, The array of the first light emitting elements and the array of the second light emitting elements are arranged at or near the focus of the projection lens. The array of the first light emitting elements is configured to be able to be individually turned on and off by means of a wiring pattern formed on the substrate. The third light emitting element is arranged to be separated from the first light emitting element via the wiring pattern.

6. The vehicle lamp according to claim 5, characterized in that: The substrate is arranged to be inclined with respect to a plane perpendicular to an optical axis of the projection lens.

7. The vehicle lamp according to claim 5, characterized in that: The vehicle lamp further includes a light shield arranged to cover the light guide.

8. The vehicle lamp according to claim 7, characterized in that: The light shield is made of metal.

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