Lamp unit

Abstract

The invention provides a novel lamp which is light in weight. The lamp unit is provided with: a light-emitting element having a light-emitting surface (40b) facing the front surface of the vehicle lamp; and a Fresnel lens (38) having an incident surface (38a) facing the light emitting surface (40b). The Fresnel lens (38) is provided with: a condensing lens section (38b) for condensing light, the condensing lens section (38b) being positioned on the front surface of the light-emitting surface (40b); and diffusion lens sections (38c, 38d) for diffusion, which are provided below the condenser lens section (38b), and on which light (L1, L2) emitted obliquely downward from the light-emitting surface (40b) is incident, the diffusion lens sections (38c, 38d) being provided below the condenser lens section (38b). The diffusion lens sections (38c, 38d) are configured so as to emit light refracted by diffusion emission surfaces (39c, 39d) that are discontinuous with the condensed light emission surface (39b) of the condensing lens section (38b) toward the front surface of the vehicle lamp.

Description

Technical Field

[0001] The present invention relates to a lamp unit, for example, to a lamp unit for a vehicle lamp. Background Art

[0002] In the past, a lamp unit has been proposed, comprising: a light emitting element array, which is formed by mounting a plurality of light emitting elements in a row on a substrate, wherein the plurality of light emitting elements each have a separate irradiation area constituting a high beam light distribution pattern and are configured to be individually lit; a projection lens, which is arranged in front of the light emitting element array; and a reflector, which is arranged below the light emitting element array (see Patent Document 1). Prior art literature Patent Literature

[0003] Patent Document 1: International Publication No. 16 / 013447 Pamphlet Summary of the invention Problems to be solved by the invention

[0004] However, from the viewpoint of heat resistance, the reflectors used in the lamp units are mostly made of metal, which is easy to become heavier. In addition, in order to reflect more light from the light emitting element toward the bottom, it is necessary to extend the depth of the reflector, and the thickness of the lamp unit in the vehicle front-rear direction becomes larger.

[0005] The present invention has been made in view of the above circumstances, and one of its exemplary objects is to provide a new lamp unit that realizes desired light distribution and is lightweight. Means for solving problems

[0006] In order to solve the above-mentioned problems, a lamp unit of a certain aspect of the present invention comprises: a light emitting element, whose light emitting surface faces the front of the vehicle lamp; and a Fresnel lens, which has an incident surface opposite to the light emitting surface. The Fresnel lens comprises: a condensing lens portion for condensing light, which is located in front of the light emitting surface; and a diffusion lens portion for diffusing light, which is arranged below the condensing lens portion, and the light emitted obliquely downward from the light emitting surface is incident on the diffusion lens portion. The diffusion lens portion is configured to emit light refracted by a diffusion emission surface that is discontinuous with the condensing emission surface of the condensing lens portion toward the front of the vehicle lamp.

[0007] According to this method, the light emitted from the light-emitting surface of the light-emitting element obliquely downward can be directed toward the front of the vehicle lamp by refraction at the diffusion lens portion. Therefore, compared with the case where the light emitted from the light-emitting surface of the light-emitting element obliquely downward is reflected by a reflector and directed toward the front of the vehicle lamp, the thickness of the optical component (Fresnel lens) required for light distribution control in the vehicle front-rear direction can be reduced. In addition, the Fresnel lens can be composed of a silicon resin lens, which can achieve a lighter lamp unit than the case where a metal reflector is used.

[0008] Alternatively, the vehicle lamp may further include a projection lens that projects the light emitted from the Fresnel lens as a light distribution pattern onto the front of the vehicle lamp. Alternatively, the diffusion lens portion may be configured so that the emitted light irradiates the upper range of the light distribution pattern. Thus, the irradiation area of ​​the light distribution pattern that irradiates above the horizontal line, such as the high beam light distribution pattern, can be further expanded.

[0009] The light emitted from the Fresnel lens may enter the projection lens without being reflected by other components. Thus, the light emitted from the Fresnel lens reaches the projection lens via a short optical path without being reflected midway, thereby improving the light utilization efficiency of the light emitting element.

[0010] The diffusion lens portion may include: a first diffusion lens portion, which is located below the condensing lens portion, and whose emission surface is located in front of the front end of the condensing lens portion; and a second diffusion lens portion, which is located below the first diffusion lens portion, and whose emission surface is located in front of the first diffusion lens portion. Thus, the thickness of the entire Fresnel lens can be suppressed, and the light emitted obliquely downward from the light-emitting surface of the light-emitting element can be used for diffusion above the irradiation area of ​​the light distribution pattern.

[0011] The second diffuser lens portion may be configured to emit light that illuminates a region of the high-beam light distribution pattern that is 6° to 8° above the horizontal line.

[0012] Optional combinations of the above-described constituent elements and modes in which the present invention is expressed in the form of a manufacturing method, a lamp, a lighting device, a light-emitting module, a light source, etc., are also effective as modes of the present invention. Effects of the Invention

[0013] According to the present invention, a new lamp unit that is lightweight can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic front view of the vehicle headlamp according to the present embodiment. Figure 2 It is through Figure 1 The horizontal plane cuts off the AA line in Figure 1 A schematic cross-sectional view of a vehicle headlamp. Figure 3 (a) is to use Figure 2 A cross-sectional view of the high beam lamp unit cut through by a plane perpendicular to line BB in FIG. Figure 3 (b) is Figure 3 An enlarged view of section C in (a). Figure 4 (a) is a front view of the Fresnel lens of this embodiment. Figure 4(b) is a perspective view of the Fresnel lens according to this embodiment. Figure 5 It is a cross-sectional view showing a main structure of the high-beam lamp unit according to the present embodiment. Figure 6 1 is a diagram showing an example of a high-beam light distribution pattern formed by a high-beam lamp unit. DETAILED DESCRIPTION

[0015] Hereinafter, the present invention will be described with reference to the accompanying drawings based on preferred embodiments. The same or equivalent components, parts, and processes shown in the drawings are marked with the same reference numerals, and repeated descriptions are appropriately omitted. In addition, the embodiments are illustrative rather than limiting inventions, and all features and combinations thereof described in the embodiments are not necessarily the essence of the invention.

[0016] Figure 1 It is a schematic front view of the vehicle headlamp 10 according to the present embodiment. Figure 2 It is through Figure 1 The horizontal plane cuts off the AA line in Figure 1 The vehicle headlamp 10 is a schematic cross-sectional view of a vehicle headlamp 10. The vehicle headlamp 10 includes a left lamp and a right lamp on the left and right sides of the front of the vehicle body, respectively, but Figure 1 Only the right lamp is shown in the figure. The left lamp has the same structure as the right lamp except that it is bilaterally symmetrical, so it is omitted in the figure.

[0017] The vehicle headlamp 10 includes a lamp chamber 11, which is composed of a lamp body 18 having an opening in the vehicle front direction (see Figure 2 ) and a transparent or translucent outer cover 16 covering the opening of the lamp body. In the lamp chamber 11, a low beam lamp unit 12 and a high beam lamp unit 14 are each configured one.

[0018] The low-beam lamp unit 12 and the high-beam lamp unit 14 are fixed to a common support plate 20. The support plate 20 is fixed to the lamp body 18 by a plurality of (e.g., three) aiming screws 48. By rotating the aiming screws 48, the optical axes O of the low-beam lamp unit 12 and the high-beam lamp unit 14 can be adjusted so as to be inclined within a predetermined angle range.

[0019] The low-beam lamp unit 12 is a so-called PES type lamp unit, and includes: a projection lens 22; a lens holder 24 that supports the projection lens 22; a light emitting element array 28, for example, composed of a plurality of semiconductor light emitting elements such as LEDs (Light Emitting Diodes); and a reflector 26 that reflects light from the light emitting element array 28 toward the projection lens 22. The low-beam lamp unit 12 also includes a heat sink 30 with a heat sink and a cooling fan 32 mounted on the back side of the support plate 20.

[0020] Figure 3 (a) is to use Figure 2 A cross-sectional view of the high-beam lamp unit 14 when a plane perpendicular to the BB line in FIG. Figure 3 (b) is Figure 3 The enlarged view of the C part in (a) is shown below. Figure 2 and Figure 3 The high-beam lamp unit 14 will be described.

[0021] The high-beam lamp unit 14 is a lamp unit capable of changing a light distribution pattern according to the running condition of the vehicle and the surrounding conditions. The high-beam lamp unit 14 includes a projection lens 34 , a lens holder 36 , a Fresnel lens 38 , and a light emitting element array 40 .

[0022] The projection lens 34 is composed of a plano-convex aspheric lens with a convex front surface and a flat rear surface, and projects the light source image formed on its rear focal plane as a reverse image onto an imaginary vertical screen in front of the lamp. The projection lens 34 is mounted on an opening of one side of a lens holder 36 formed in a cylindrical shape.

[0023] The light emitting element array 40 is composed of one or more (12 in the present embodiment) semiconductor light emitting elements 40a mounted on a substrate 41. Each semiconductor light emitting element 40a has the same shape as each other and is arranged linearly on the surface of the substrate 41 with the light emitting surface facing the front of the vehicle headlamp 10. Each light emitting element can be turned on and off individually, and is configured to be able to illuminate a separate illumination area formed by dividing the high beam light distribution pattern in the horizontal direction. Preferably, at least a portion of the separate illumination area of ​​each light emitting element overlaps with the separate illumination area of ​​an adjacent light emitting element.

[0024] The semiconductor light emitting element 40a includes a light emitting chip (not shown) and a thin film. The light emitting chip is composed of a white light emitting diode having a square light emitting surface of about 1 mm square. In addition, the light emitting chip is not limited thereto, and may be, for example, a light source in the form of other elements that emit light in a roughly point-like manner, such as a laser diode. The rear focus F of the projection lens 34 may be located on the surface of the semiconductor light emitting element 40a, or may be located in front of the surface of the semiconductor light emitting element 40a as described later.

[0025] A Fresnel lens 38 is disposed in front of the light emitting element array 40. Figure 3 As shown in FIG. 2( b ), the Fresnel lens 38 has an incident surface 38 a facing the light emitting surface 40 b of the semiconductor light emitting element 40 a .

[0026] like Figure 3 As shown in FIG. 2( b ), a light shielding plate 42 is provided in front of the light emitting element array 40 , and the light shielding plate 42 shields a part of the light emitted from the light emitting element array 40 .

[0027] A control unit 49 for controlling the lighting and extinguishing of the light emitting element array 40 is arranged on the bottom surface of the lamp body 18. The control unit 49 detects the position of the vehicle or pedestrian in front through a camera (not shown) and controls the light emitting element array 40 so as not to illuminate the separate illumination area corresponding to the position, thereby realizing ADB (Adaptive Driving Beam) that does not cause glare to the driver of the vehicle in front or the pedestrian.

[0028] The high-beam lamp unit 14 further includes a heat sink 44 with fins and a cooling fan 46 which are attached to the back side of the support plate 20 .

[0029] Resin extension members 50 , 52 , and 54 are disposed in the lamp chamber 11 to cover gaps formed between the low-beam lamp unit 12 , the high-beam lamp unit 14 , and the lamp body 18 , and to conceal the internal structure when the vehicle headlamp 10 is viewed from the front.

[0030] Figure 4 (a) is a front view of the Fresnel lens of this embodiment. Figure 4 (b) is a perspective view of the Fresnel lens according to this embodiment. Figure 5 It is a cross-sectional view showing a main structure of the high-beam lamp unit 14 according to the present embodiment.

[0031] like Figure 5As shown, the high beam lamp unit 14 includes: a semiconductor light emitting element 40a, a light emitting surface 40b facing the front of the vehicle headlamp 10; a Fresnel lens 38, having an incident surface 38a opposite to the light emitting surface 40b; and a projection lens 34, which projects the light emitted from the Fresnel lens 38 as a light distribution pattern onto the front of the vehicle lamp.

[0032] The Fresnel lens 38 includes a condensing lens portion 38b for condensing light, which is located in front of the light emitting surface 40b; a diffusing lens portion 38c for diffusing light, which is provided below the condensing lens portion 38b and on which the light L1 emitted obliquely downward from the light emitting surface 40b enters; and a diffusing lens portion 38d for diffusing light, on which the light L2 emitted obliquely downward from the light emitting surface 40b more than the light L1 enters. The diffusing lens portions 38c and 38d are configured so that the light refracted by the diffusing emission surfaces 39c and 39d that are discontinuous with the condensing emission surface 39b of the condensing lens portion 38b is emitted toward the front of the high-beam lamp unit 14.

[0033] like Figure 4 (a) Figure 4 As shown in (b) of FIG. 8 , the Fresnel lens 38 is composed of twelve condensing lens portions 38 b and twelve pairs of diffusion lens portions 38 c and 38 d so as to correspond to the twelve semiconductor light emitting elements 40 a , respectively.

[0034] Thus, the high-beam lamp unit 14 can direct the light L1 and L2 emitted obliquely downward from the light-emitting surface 40b of the semiconductor light-emitting element 40a toward the front of the vehicle headlamp 10 by refraction at the diffusion lens portions 38c and 38d. Therefore, compared with the case where the light L1 and L2 emitted obliquely downward from the light-emitting surface 40b of the semiconductor light-emitting element 40a are reflected by a reflector and directed toward the front of the vehicle lamp, the thickness of the Fresnel lens 38 required for light distribution control in the vehicle front-rear direction (X direction) can be reduced. In addition, the Fresnel lens 38 can be formed of a resin lens made of silicon, and compared with the case where a metal reflector is used, the high-beam lamp unit 14 can be made lighter.

[0035] Figure 6 1 is a diagram showing an example of a high-beam light distribution pattern formed by the high-beam lamp unit 14. The diffuser lens portions 38c and 38d are configured to emit light that illuminates an upper range R1 of the high-beam light distribution pattern PH. This can further expand the illumination area of ​​the high-beam light distribution pattern that illuminates a light distribution pattern above the horizontal line.

[0036] Furthermore, the light L3 emitted obliquely upward from the light emitting surface 40b is refracted by the condensing lens portion 38b and further refracted by the projection lens 34, thereby irradiating the lower range R2 of the high-beam light distribution pattern PH. Thus, in a light distribution pattern such as the high-beam light distribution pattern that mainly irradiates light above the horizontal line, it is possible to illuminate the area below the horizontal line, that is, the road surface.

[0037] The projection lens 34 of the present embodiment is arranged at a position where the light emitted from the Fresnel lens 38 is incident without being reflected by other components, in other words, at a position where the light emitted from the Fresnel lens 38 is directly incident. As a result, the light emitted from the Fresnel lens 38 reaches the projection lens 34 through a short optical path without being reflected or transmitted through other components, thereby improving the utilization efficiency of the light of the semiconductor light emitting element 40a.

[0038] The diffusion lens portion of this embodiment includes: a diffusion lens portion 38c, which is located below the condensing lens portion 38b, and a diffusion emission surface 39c, which is located in front of the front end of the condensing lens portion 38b; and a diffusion lens portion 38d, which is located below the diffusion lens portion 38c, and a diffusion emission surface 39d, which is located in front of the diffusion lens portion 38c. Thus, the thickness of the entire Fresnel lens 38 can be suppressed, and the light emitted obliquely downward from the light emitting surface 40b of the semiconductor light emitting element 40a can be used for diffusion above the irradiation area of ​​the high-beam light distribution pattern PH.

[0039] In particular, the diffuser lens portion 38d is configured to emit light irradiating an area of ​​the high-beam light distribution pattern PH that is 6° to 8° above the horizontal line. Alternatively, the diffuser lens portion 38d may also be configured to emit light irradiating an area of ​​the high-beam light distribution pattern PH that is 6° or more, preferably 8° or more above the horizontal line. In addition, since the diffuser emission surface 39d is located at a position forward of the diffuser lens portion 38c, the diffuser lens portion 38d can further increase the luminous intensity of the upper range R1 of the high-beam light distribution pattern PH, and can improve the utilization rate of the light emitted from the semiconductor light emitting element 40a.

[0040] In addition, the high-beam light distribution pattern PH of the present embodiment is formed by projecting the transmitted light (refracted light) that has passed through the Fresnel lens 38, out of the light emitted from the light emitting element array 40, to the front of the vehicle through the projection lens 34. Therefore, compared with a light distribution pattern in which direct light and reflected light are mixed, as in the case of using a reflector, unevenness of light and dark in the light distribution pattern can be reduced.

[0041] The light emitting surface 40b of the semiconductor light emitting element 40a of the present embodiment may also be a rectangle with a side of about 0.8 to 2.0 mm. In addition, the distance between the light emitting surface 40b of the semiconductor light emitting element 40a and the incident surface 38a of the Fresnel lens 38 is very close, about 0.5 mm to 1.5 mm. Therefore, the material of the Fresnel lens 38 is preferably a material that takes heat resistance and moldability into consideration, for example, it may be made of silicon or glass. In addition, the thickness of the Fresnel lens 38 in the Z direction is about 5 mm to 10 mm, and the thickness of the focusing lens portion 38b in the Z direction is about 2 mm to 5 mm. In addition, the thickness of the projection lens 34 in the Z direction is about 20 mm to 30 mm. In addition, the distance between the light emitting surface 40b of the semiconductor light emitting element 40a and the incident surface 34a of the projection lens 34 is about 20 mm to 40 mm.

[0042] The present invention has been described above with reference to the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, and a mode in which the configurations of the embodiments are appropriately combined or replaced is also included in the present invention. In addition, based on the knowledge of those skilled in the art, the combination of the embodiments or the order of processing may be appropriately reorganized, or various design changes or other deformations may be applied to the embodiments, and the embodiments to which such deformations are applied are also included in the scope of the present invention.

[0043] The present international application claims priority based on Japanese Patent Application No. 2022-144144 filed on September 9, 2022, and the entire contents of Japanese Patent Application No. 2022-144144 are incorporated herein by reference.

[0044] The above description of specific embodiments of the present invention is provided for the purpose of illustration. They are not intended to be exhaustive, nor are they intended to limit the present invention directly to the described embodiments. It is obvious to those skilled in the art that many modifications and changes can be made based on the above described contents. Description of reference numerals:

[0045] 10: vehicle headlamp; 14: high beam lamp unit; 34: projection lens; 34a: incident surface; 38: Fresnel lens; 38a: incident surface; 38b: focusing lens portion; 38c: diffusion lens portion; 38d: diffusion lens portion; 39b: focusing emission surface; 39c: diffusion emission surface; 39d: diffusion emission surface; 40: light emitting element array; 40a: semiconductor light emitting element; 40b: light emitting surface; R1: upper range; R2: lower range; PH: light distribution pattern for high beam.

Claims

1. A lamp unit, characterized in that: have: A light-emitting element, the light-emitting surface of which faces the front side of the vehicle lamp; and A Fresnel lens having an incident surface opposite to the light emitting surface, The Fresnel lens has: A focusing lens portion for focusing light, located in front of the light-emitting surface; and The diffusion lens part for diffusion is arranged below the condensing lens part, and the light emitted obliquely downward from the light emitting surface is incident on the diffusion lens part. The diffusion lens portion is configured to emit light refracted by a diffusion emission surface that is not continuous with the condensing emission surface of the condensing lens portion toward the front of the vehicle lamp.

2. The lamp unit according to claim 1, characterized in that: The lamp unit further includes a projection lens configured to project the light emitted from the Fresnel lens as a light distribution pattern onto the front surface of the vehicle lamp. The diffusion lens portion is configured to illuminate an upper range of the light distribution pattern with emitted light.

3. The lamp unit according to claim 2, characterized in that: The light emitted from the Fresnel lens is incident on the projection lens without being reflected by other components.

4. The lamp unit according to any one of claims 1 to 3, characterized in that: The diffusion lens portion has: a first diffusion lens portion located below the condensing lens portion, and having an emission surface located forward of a front end of the condensing lens portion; as well as The second diffusion lens section is located below the first diffusion lens section, and the emission surface is located in front of the first diffusion lens section.

5. The lamp unit according to claim 4, characterized in that: The second diffuser lens portion is configured to emit light that illuminates a region 6° to 8° above the horizontal line of the high-beam light distribution pattern.

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