Lamp for vehicle

Abstract

To provide a lamp for a vehicle having a simple structure in which a decorative pattern can be seen so as to be floated on a lens being a light guide member at only lighting.SOLUTION: In a lamp for a vehicle, a plate-shaped transparent lens 43 being a light guide member which is arranged in a face-to-face manner, a diffusion material sheet 44 laminated on a front face side of the lens 43, and an LED 47 oppositely arranged at a light incident part 43a of a lens side face are arranged in a lamp chamber, and a decorative part 50 for emitting light by guide light of the lens 43 is arranged in a prescribed region of the lens 43 in a front-face view. The decorative part 50 is constituted of a joining part (a laser fusion part 50 or a transparent adhesive layer) extending along an interface between the diffusion material sheet 44 and the lens 43, and introducing the guide light of the lens 43 to the diffusion material sheet 44 by integrating the diffusion material sheet 44 and the lens 43.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a vehicle lamp provided with a decorative portion that emits light by light guiding on a lens that is a light guiding member, and more particularly to a vehicle lamp in which a predetermined decorative pattern that is not visible when not lit floats up when lit.

Background Art

[0002] As this type of vehicle lamp, there are various proposals as shown in Patent Documents 1 to 3 below.

[0003] Patent Document 1 describes a lamp structure in which "in an LED lamp unit 1 provided with a light guide plate 2, an uneven light diffusion pattern 6 which is a decorative portion is formed on the entire back surface of the light guide plate 2 disposed on the front surface side of the reflector 4, and when lit, a part of the light guiding in the light guide plate 2 is reflected by the uneven light diffusion pattern 6 on the back surface 2b of the light guide plate 2 and is emitted as diffused light from the emission surface 2a of the light guide plate 2, and a part of the light guiding in the light guide plate 2 is emitted from the back surface 2b of the light guide plate 2, reflected by the reflector 4 and re-incident on the light guide plate 2, and then emitted as diffused light from the emission surface 2a of the light guide plate 2, thereby obtaining illumination with uniform brightness."

[0004] Patent Document 2 describes a decorative panel 1 that constitutes an operation panel for a car air conditioner, in which "a molding resin layer 4 for emitting the light of an LED 7 incident on a light guiding member 2 is laminated on the front surface side of the light guiding member 2, and a decorative film 8 having a metallic luster which is a decorative portion (design portion D) is provided on the outer peripheral surface (inclined surface) 4a of the molding resin layer 4, and when lit, the decorative film 8 is visually recognized with a sense of depth in an annular shape (the decorative film 8 appears to float up in an annular shape)" through an annular second through hole 5b formed in a black light shielding layer 5 covering the front surface side of the molding resin layer 4.

[0005] Patent Document 3 (Embodiment 3) describes a lamp structure in which "a side turn signal lamp 201 equipped with a light guide lens 246 is assembled to a door mirror 2, and a decorative portion 232 is formed on the back surface of an inner lens 240 arranged along the front surface of the light guide lens 246, so that when the lamp is lit, the light guided in the light guide lens 246 is reflected by a reflection step 250 on the back surface of the lens 246 and emitted from the front surface of the light guide lens 246, and when the light is distributed through the inner lens 240 and the outer cover 14, the decorative pattern formed by the decorative portion 232 on the back surface of the inner lens 240 becomes visible." In addition, in the sections on [Background Art] and [Problems to be Solved by the Invention], the descriptions explaining the configuration of each of the Patent Documents 1 to 3 are denoted by the reference numerals used in the [Modes for Carrying Out the Invention] of each document. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2010-3597 (see paragraphs 0019 to 0030 and Figures 1 to 7) [Patent Document 2] Japanese Patent Publication No. 2014-85456 (see paragraphs 0013 to 0031, Figures 1 and 2) [Patent Document 3] Japanese Patent Publication No. 2019-96462 (see paragraphs 0044-0067 and Figures 7-11) [Overview of the project] [Problems that the invention aims to solve]

[0007] The first challenge is that, in all of the prior patent documents 1 to 3, the lamp structure becomes complex, requiring a configuration that makes a predetermined decorative part invisible when the light is not illuminated.

[0008] In more detail, Patent Document 1 describes a light guide plate 2 positioned on the front side of the reflector plate 4, which is formed to be relatively thick. When the light is not illuminated, the uneven light diffusion pattern 6 on the back of the light guide plate 2 is not visible. However, if the light guide plate 2 is thin, it is necessary to form a half-mirror film on the front surface of the light guide plate 2, for example.

[0009] Furthermore, Patent Document 2 states that a light-shielding layer 5 is essential to suppress light emission in areas other than the decorative part D when the light is on, and to make the entire area other than the decorative part D appear uniform when the light is off.

[0010] Furthermore, Patent Document 3 states that a half-mirror film 230 on the front surface of the inner lens 240 is essential so that the decorative part 232 is not visible when the light is not illuminated.

[0011] Furthermore, the second challenge is as follows:

[0012] In the aforementioned Patent Document 1, the decorative pattern (uneven light-diffusing pattern) 6 is formed by texturing, painting, printing, or dotting (see paragraph 0023), so the types of decorative patterns that can be formed are limited. Therefore, there is little freedom in the decorative pattern that appears when the light is turned on.

[0013] In the aforementioned Patent Document 2, the decorative film 8 is formed on the outer peripheral surface 4a of the molded resin layer 4 by insert molding (see paragraphs 0018 and 0019), and an annular second through-hole 5b is formed in the black light-shielding layer 5 on the back of the front plate 6 that covers the front of the decorative film 8, thereby creating a decorative portion (design portion D) that appears to float in an annular shape. For this reason, the number of processing steps required to form the decorative portion (design portion D) is large, the types of patterns that can be formed in the decorative portion (design portion D) are limited, and there is little freedom in the decorative pattern that appears when lit.

[0014] In the aforementioned Patent Document 3, the decorative portion 232 is formed on the inner lens 240 by laser decoration or a mold (see paragraph 0053). As a result, there are many processing steps required to form the decorative portion, and the types of decorative patterns that can be formed are limited, resulting in little freedom in the decorative pattern that appears when the light is turned on.

[0015] The present invention has been made in view of the problems of the prior art described above. The first object of the present invention is to provide a vehicle lamp with a simple structure in which a decorative pattern appears to float on the lens, which is a light guide member, only when it is lit. The second object of the present invention is to provide a vehicle lamp in which it is easy to form a decorative part on the lens, which is a light guide member, and which has excellent freedom in the decorative part that can be formed (decorative pattern that appears when lit). [Means for solving the problem]

[0016] To achieve the first objective described above, in a vehicle lighting device according to a certain embodiment of the present invention, A vehicle lamp comprising a plate-shaped translucent resin lens, which is a light guide member positioned to face the front of the lamp chamber, a translucent resin diffuser sheet laminated on the front side of the lens, and an LED, which is a light source positioned to face the light incident portion on the side of the lens, wherein a decorative part that emits light due to the light guided by the lens is provided in a predetermined area when viewed from the front of the lens, The decorative portion is configured as a translucent joint that extends along the interface between the diffusion material sheet and the lens, and joins the diffusion material sheet and the lens together to guide the light from the lens to the diffusion material sheet.

[0017] (Function) The light-transmitting resin diffusion material sheet has fine particles dispersed in it, and light incident on the back of the sheet is emitted from the front of the sheet as diffused light.

[0018] Furthermore, the decorative portion (a decorative portion that emits light due to the light guided by the lens) provided in a predetermined area when viewed from the front of the translucent lens extends along the interface between the diffuser sheet and the lens, and is composed of a translucent joint that joins the diffuser sheet and the lens together and guides the light guided by the lens to the diffuser sheet. Therefore, when the light fixture is turned on, only the joint (decorative portion) emits light, and a predetermined pattern (decorative pattern) formed by the joint (decorative portion) appears to stand out on the diffuser sheet.

[0019] Specifically, there is always air (layer) at the interface between the laminated plate-like two members. That is, since there is always air (layer) on the outer surface of the region of the plate-like lens, which is a light guide member, excluding the joint with the diffusion sheet, the light incident from the LED to the lens is repeatedly totally reflected without leakage at the front and back surfaces of the lens (interface with a sharp change in refractive index), and is guided through the lens.

[0020] On the other hand, since there is no air (layer) at the joint between the lens and the diffusion sheet, the light guiding of the lens is guided to the diffusion sheet through the joint (decoration part), and is emitted as diffused light from the front surface of the diffusion sheet.

[0021] Also, since the translucent diffusion sheet itself in which the fine particles are dispersedly arranged is not visible through, when the lamp is not lit, the entire diffusion sheet exhibits a uniform color tone, and the predetermined pattern (decoration pattern) formed by the decoration part constituted by the joint does not appear on the diffusion sheet, so the appearance of the lamp is improved.

[0022] That is, in the vehicle lamp of this aspect, the structure such as the reflector behind the light guide plate, the light shielding layer that suppresses the light emission in the region other than the decoration part, and the half mirror film formed on the front surface of the inner lens, which are indispensable in the prior patent documents, is not required, and the lamp structure becomes simple.

[0023] Also, in order to achieve the second object, in the vehicle lamp of another aspect of the present invention, The joint that constitutes the decoration part may be constituted by a laser welding part that straddles the interface between the diffusion sheet and the lens.

[0024] (Function) After the region including the interface between the laminated diffusion sheet and the lens is melted (liquefied at a temperature equal to or higher than the melting point Tm) by the irradiation of the laser light, the region that becomes a hard glassy state (solid) at a temperature equal to or lower than the glass transition temperature Tg is called a laser welding part. Laser welding is the irradiation of laser light to weld the region including the interface between the diffusion sheet and the lens.

[0025] Furthermore, since there is no interface with air (layer) present in the laser-welded portion, which is a translucent joint that joins the diffuser sheet and the lens together, the light guided by the lens is directed to the diffuser sheet through this joint (laser-welded portion) and emitted as diffused light from the front surface of the diffuser sheet.

[0026] Therefore, when the light fixture is turned on, the laser-welded portion that spans the interface between the diffuser sheet and the lens, which is a translucent joint constituting the decorative part, emits light uniformly, and the predetermined pattern (decorative pattern) formed by the laser-welded portion becomes visible on the diffuser sheet.

[0027] Furthermore, by scanning the laser irradiation unit (laser beam) of the laser irradiation device to trace a predetermined pattern (in this embodiment, the letters A, B, C), the area along the interface between the diffuser sheet and the lens is laser-welded. The laser-welded portion that spans the interface between the diffuser sheet and the lens forms a predetermined decorative pattern that extends along the interface between the diffuser sheet and the lens. Thus, the formation of the translucent joint (laser-welded portion) constituting the decorative portion is simple and easy. Moreover, by arbitrarily setting the scanning pattern of the laser irradiation unit (laser beam) of the laser irradiation device, a desired decorative pattern can be formed. In other words, there is a high degree of freedom in the laser-welded portion (decorative pattern) that can be formed on the lens.

[0028] According to this embodiment of the vehicle lighting device, the formation of a decorative portion (laser-welded portion) on the lens, which is a light guide member, is easy, and a vehicle lighting device is provided that offers excellent freedom in the decorative portion that can be formed (decorative pattern that appears when lit).

[0029] In another embodiment of the present invention, a vehicle light fixture, The diffusion material sheet has a structure in which a light diffusion layer, in which transparent fine particles are dispersed in a transparent binder, is laminated and integrated on the front surface of a transparent resin substrate sheet, and the laser-welded portion may be formed spanning between the substrate sheet and the lens, excluding the light diffusion layer of the diffusion material sheet.

[0030] (Effect) If the laser-welded portion extends across to the light diffusion layer of the diffusion material sheet, when the region including the interface between the diffusion material sheet and the lens is laser-welded, not only the base sheet but also the light diffusion layer (the fine particles dispersed within it) may melt, potentially impairing the light diffusion function of the diffusion material sheet (light diffusion layer).

[0031] However, in this embodiment of the vehicle lighting device, the laser-welded portion spans between the base sheet and the lens, excluding the light-diffusing layer of the diffuser sheet, and the light-diffusing layer does not constitute the laser-welded portion (the light-diffusing layer is not included in the laser-welded portion).

[0032] In other words, the light diffusion layer of the diffusion material sheet is not affected by the heat (melting of the fine particles dispersed in the light diffusion layer) that occurs when the interface between the diffusion material sheet and the lens is laser-welded, and the morphology of the light diffusion layer, in which transparent fine particles are dispersed in the binder, is maintained even after laser welding.

[0033] Therefore, with this embodiment of the vehicle lighting device, when the lighting device is turned on, the laser-welded portion, which is a translucent joint constituting the decorative portion, emits light reliably and uniformly, and the predetermined pattern (decorative pattern) formed by the laser-welded portion on the diffusion material sheet becomes visible.

[0034] Furthermore, in a vehicle lighting device according to another aspect of the present invention, The lens and the diffusion sheet may be made of a compatible resin.

[0035] (Function) Because the diffusion material sheet (base sheet) is very thin, a low-power laser irradiation device is required for laser welding of the diffusion material sheet (base sheet) and the lens. However, since the melting temperatures of the lens, which is made of a compatible resin, and the diffusion material sheet (base sheet) are almost the same, the area along the interface between the diffusion material sheet (base sheet) and the lens melts smoothly when irradiated with laser light, making it easy to form a laser-welded area that spans the interface between the diffusion material sheet (base sheet) and the lens.

[0036] In other words, with this embodiment of the vehicle lighting device, the process of laser welding the diffuser sheet and the lens can be carried out smoothly in such a way that the light diffusion function of the diffuser sheet is maintained.

[0037] Furthermore, in a vehicle lighting device according to another aspect of the present invention, The thickness of the lens may be 1.0 to 20 mm, the thickness of the diffusion material sheet may be 100 μm to 1.5 mm, and the thickness of the base material sheet may be 50 μm to 1.0 mm.

[0038] (Function) The light emitted from the LED light source has directionality (diffusion angle), and if the lens plate thickness is less than 1.0 mm, it is difficult to get the light source into the lens (the efficiency of light incidence from the side of the lens is poor). Also, in order to ensure the rigidity and strength of the lens, a lens plate thickness of 1.0 mm or more is desirable.

[0039] On the other hand, if the lens thickness exceeds 20 mm, the number of times the light incident on the lens is reflected within the lens increases, and the relative light guide distance becomes longer. This increases the energy loss of the light guided within the lens, and the amount of light guided from the laser-welded joint (the joint) to the diffuser sheet decreases relative to the amount of light incident on the lens. As a result, the ratio of the amount of light emitted from the diffuser sheet to the amount of light incident on the lens decreases. Furthermore, in order to uniformly incident the light source light across the entire lens with a large light guide cross-sectional area, it is necessary to increase the number of LEDs or the light output of the LEDs, which increases costs. In addition, the front-to-back length of the luminaire increases, making the luminaire larger, so the lens thickness should be 20 mm or less. Therefore, a lens thickness of 1.0 mm to 20 mm is desirable.

[0040] Furthermore, while the laser-welded area is formed by the melting of the region along the interface between the diffuser sheet and the lens due to laser irradiation, if the laser output is too high, the diffuser sheet, which is thinner than the lens, may be damaged, impairing the light diffusion function of the diffuser sheet in the laser-welded area. Additionally, the surface of the diffuser sheet may become wavy due to heat, impairing its smoothness. This can lead to concerns such as uneven illumination of the decorative part (decorative pattern) when lit, or a decrease in the appearance of the lens when not lit.

[0041] Therefore, when laser welding, it is necessary to adjust the laser beam output and irradiation time so that the diffusion material sheet is not damaged, the interface between the diffusion material sheet and the lens reaches an appropriate melting temperature, the area spanning the interface between the diffusion material sheet and the lens is smoothly welded, and the surface of the diffusion material sheet does not warp due to heat, thus preventing the smoothness of the laser-welded area from being compromised.

[0042] Furthermore, when the thickness of the diffusion material sheet is less than 100 μm, it is difficult to laser-weld the diffusion material sheet and the lens without damaging the diffusion material sheet and while maintaining the smoothness of the diffusion material sheet surface.

[0043] On the other hand, if the thickness of the diffusion material sheet exceeds 1.5 mm, the rigidity of the diffusion material sheet increases, and in the case of a curved lens shape, the diffusion material sheet cannot follow the curved lens surface shape, and a gap is formed between the diffusion material sheet and the lens. This gap reduces the heat transfer efficiency in the laser light irradiation area and suppresses the rise in temperature in the laser light irradiation area, thus hindering smooth laser welding of the area including the interface between the diffusion material sheet and the lens. Therefore, the thickness of the diffusion material sheet is preferably between 100 μm and 1.5 mm.

[0044] Furthermore, the diffusion material sheet has a structure in which a light diffusion layer is laminated and integrated with the base sheet. Ideally, the light diffusion layer of the diffusion material sheet should not be affected by the heat generated when the diffusion material sheet and the lens are laser-welded together. However, when the thickness of the base sheet is less than 50 μm, it is difficult to adjust the laser output and irradiation time so that the interface between the base sheet and the lens reaches an appropriate melting temperature, while the light diffusion layer remains below the melting temperature.

[0045] On the other hand, if the thickness of the base sheet exceeds 1.0 mm, the light diffusion layer becomes less than 0.5 mm thick compared to the desirable thickness of the diffusion material sheet (1.5 mm or less), reducing the number of fine particles dispersed in the light diffusion layer and resulting in insufficient light diffusion function of the diffusion material sheet (light diffusion layer). Furthermore, if the thickness of the base sheet exceeds 1.0 mm, the rigidity of the diffusion material sheet increases, and in the case of a curved lens shape, the diffusion material sheet cannot follow the curved lens surface shape. Therefore, the thickness of the base sheet is preferably between 50 μm and 1.0 mm.

[0046] Furthermore, in order to achieve the second objective, in another embodiment of the present invention, a vehicle lighting device includes: The joint portion constituting the decorative portion may be composed of a translucent adhesive layer formed along the interface between the diffusion material sheet and the lens.

[0047] (Function) The translucent adhesive layer, which is the joint that bonds the diffuser sheet and the lens together, functions as a joint that guides the light guided by the lens to the diffuser sheet. More specifically, the translucent adhesive layer (joint) that bonds the diffuser sheet and the lens together is in close contact with the diffuser sheet and the lens, respectively, and there are no interfaces between the diffuser sheet, the translucent adhesive layer and the lens where air (layers) exist. Therefore, the light guided by the lens is guided to the diffuser sheet via the translucent adhesive layer and emitted as diffused light from the front surface of the diffuser sheet.

[0048] Therefore, when the light fixture is turned on, the translucent adhesive layer formed along the interface between the diffuser sheet and the lens, which constitutes the decorative part, emits light uniformly, and the predetermined pattern (decorative pattern) formed by the translucent adhesive layer on the diffuser sheet becomes visible.

[0049] Furthermore, by applying a translucent adhesive to the surface of the lens in a manner that traces a predetermined pattern (in this embodiment, the letters A, B, C), and pressing a diffusion material sheet onto the adhesive-coated surface of the lens, the translucent adhesive between the diffusion material sheet and the lens is crushed, causing the translucent adhesive layer extending along the interface between the diffusion material sheet and the lens to form a predetermined decorative pattern. Thus, the formation of the joint (translucent adhesive layer) constituting the decorative part is simple and easy. Moreover, by arbitrarily setting the scanning pattern of the adhesive application section of the adhesive application device, a desired decorative pattern can be formed. In other words, there is a high degree of freedom in the translucent adhesive layer (decorative pattern) that can be formed on the lens.

[0050] According to this embodiment of the vehicle lighting device, it is easy to form a decorative portion (translucent adhesive layer) on the lens, which is a light guide member, and a vehicle lighting device is provided that offers excellent freedom in the decorative portion that can be formed (decorative pattern that appears when lit). [Effects of the Invention]

[0051] As is clear from the above description, the present invention provides a vehicle light fixture with a simple structure in which a decorative pattern appears to float on the lens, which is a light guide member, only when the light is turned on.

[0052] Furthermore, a vehicle light fixture is provided that allows for easy formation of decorative parts on the lens, which is a light guide element, and offers excellent freedom in the design of the decorative parts that can be formed (decorative patterns that appear when the light is on). [Brief explanation of the drawing]

[0053] [Figure 1] This is a front view of an automotive headlamp incorporating a daytime running lamp, which is a first embodiment of the present invention. [Figure 2] This is a horizontal cross-sectional view of the headlamp (a cross-sectional view along line II-II shown in Figure 1). [Figure 3] This is a longitudinal cross-sectional view of the headlamp (a cross-sectional view along line III-III shown in Figure 1). [Figure 4] This is a horizontal cross-sectional view of a light source unit for daytime running lamps (a cross-sectional view along line IV-IV shown in Figure 1). [Figure 5] This is an enlarged cross-sectional view of the joint (laser-welded section) that forms the decorative part, where the diffusion material sheet and the lens are joined together as a single unit. [Figure 6] This is an explanatory diagram of the laser welding process between the diffusion material sheet and the lens. [Figure 7] (a) and (b) are diagrams illustrating the laser welding process when the lens surface is curved. [Figure 8] This is a horizontal cross-sectional view (corresponding to Figure 4) of a light source unit for a daytime running lamp, which is the main part of the second embodiment of the present invention. [Figure 9] This is an enlarged cross-sectional view (corresponding to Figure 5) of the joint (translucent adhesive layer) that forms the decorative portion by joining the diffusion material sheet and the lens together. [Figure 10] This is an explanatory diagram of the bonding process between the diffusion material sheet and the lens. [Modes for carrying out the invention]

[0054] Embodiments of the present invention will be described below.

[0055] Figures 1-3 show an automotive headlamp incorporating a daytime running lamp, which is a first embodiment of the present invention; Figure 4 shows the structure of a light source unit for the daytime running lamp; Figure 5 shows the structure of a joint (laser-welded part) that forms the decorative part, which joins and integrates the diffuser sheet and the lens; and Figure 6 shows the laser welding process between the diffuser sheet and the lens.

[0056] In these figures, particularly in Figures 1 to 3, reference numeral 10 denotes an automotive headlamp incorporating a daytime running lamp 40 (the headlamp on the left side as seen from the driver's perspective, i.e., the right side when facing the front of the vehicle). A front cover 14 is assembled to the front opening of the lamp body 12, defining a lamp chamber S. In the upper part of the lamp chamber S, headlamp light source units U10 and U20 are provided adjacent to each other on the left and right sides, and below the space between the light source units U10 and U20 in the lamp chamber S, a light source unit U40 for the daytime running lamp 40 is provided.

[0057] The light source unit U10 is a light source unit for forming a high beam, and comprises a rectangular metal base 15 when viewed from the front, an LED alloy 16 (LED substrate 16b on which LED chips 16a are mounted) which is a light source located on the inside in the vehicle width direction on the front surface of the base 15, a cylindrical lens holder 17 fixed to the base 15 and extending forward, and a projection lens 18 positioned at a predetermined position in front of the LED alloy 16 by the lens holder 17, wherein the LED alloy 16 is arranged so that the LED chips 16a face forward.

[0058] On the other hand, the light source unit U20 is a light source unit for forming a low beam, and comprises a metal base 15, a metal lens holder 20 fixed to the outer side in the vehicle width direction of the front surface of the base 15 and extending forward, an LED alloy 22 (LED substrate 22b with LED chips 22a mounted on it) which is a light source positioned on the upper surface of the lens holder 20, a reflector 24 positioned on the upper surface of the lens holder 20 and covering the LED alloy 22, and a projection lens 26 positioned in front of the LED alloy 22 and reflector 24 by the lens holder 20, wherein the LED alloy 22 is arranged so that the LED chips 22a face upward, and a shade 25 for forming a cutoff line in the light distribution pattern for the low beam is formed on the upper surface of the lens holder 26.

[0059] At positions corresponding to the light source units U10 and U20 behind the metal base 15, heat sinks 28, each consisting of heat dissipation fins 28a and a cooling fan 28b, are provided. By releasing the heat generated by the light source LED alloys 16 and 22 into the lamp chamber S, a decrease in the luminous efficiency of the LED alloys 16 and 22 is suppressed.

[0060] An aiming mechanism 30 is interposed between the metal base 15 and the rear wall 12a of the lamp body, consisting of three aiming screws 32 that extend forward through the rear wall 12a of the lamp body and a nut member 34 provided on the metal base 15 for engaging the aiming screws 32. By rotating the aiming screws 32, the optical axes of the light source units U10 and U20 can be tilted and adjusted in a unified manner in the up, down, left, and right directions.

[0061] An extension reflector 27, whose surface is treated with aluminum vapor deposition, is positioned at the front of the lamp chamber S. The extension reflector 27 has openings 27a, 27b, and 27c that correspond to the light source units U10, U20, and U40, so as not to obstruct the light emitted from the light source units U10, U20, and U40 when each lamp is lit, and also makes the entire area around the light source units U10, U20, and U40 in the lamp chamber S appear to be the same color when all lamps are not lit, thereby improving the appearance of the automotive headlamp 10.

[0062] Although the extension reflector 27 is located inside the front cover 14 within the lamp chamber S, and therefore the interior of the lamp chamber S cannot be seen when viewing the automotive headlamp 10 from the front, Figure 1 shows the extension reflector 27 as a dashed line to clarify the arrangement of the light source units U10, U20, and U40 within the lamp chamber S. The light source units U10 and U20, the aiming mechanism 30 (32, 34), and the light source unit U40, all integrated into the metal base 15, are shown to be visible through the reflector.

[0063] Furthermore, as shown in Figures 1, 3, and 4, the light source unit U40 for the daytime running lamp 40 has a front-view rectangular case 41 with an open front, which houses a lens-diffuser sheet laminate 42 in which a translucent resin diffuser sheet 44 is laminated and integrated on the front side of a flat translucent resin lens 43, which is a rectangular light guide member in front view, and an LED 47, which is a light source that faces the light incident part 43a (see Figure 4) on the side of the lens 43. A front frame 48 is fixed to the front opening of the case 41, forming a rectangular opening 48a that is slightly smaller than the outer shape of the lens-diffuser sheet laminate 42. The light source unit U40 is fixed to the inside of the bottom wall 12b of the lamp body, for example, with a bracket B (see Figure 3), and is positioned to face the front of the lamp chamber S.

[0064] Furthermore, rectangular frame members 49 with a U-shaped cross-section are provided on the top, bottom, left, and right side edges of the lens-diffuser sheet laminate 42 to fix and hold the lens 43 and diffuser sheet 44 in a laminated form, and to prevent light guided by the lens 43 from leaking out from the lens side edges. Reference numeral 49a in Figure 4 indicates an opening formed in the frame member 49 at a position corresponding to the light incident portion 43a of the lens 43, and the light emitted from the LED 47 enters the lens 43 from the light incident portion 43a exposed to this opening 49a.

[0065] As shown in Figure 4, a laser-welded decorative portion 50 is formed between the diffuser sheet 44 and the lens 43 of the lens-diffuser sheet laminate 42, extending along the interface L between the two 44 and 43. The laser-welded portion 50 is formed across the interface L between the diffuser sheet 44 and the lens 43, joining and integrating the diffuser sheet 44 and the lens 43, and also functions as a translucent joint that guides the light from the lens 43 to the diffuser sheet 44. In this embodiment, the laser-welded portion 50 extends to form the predetermined letters ABC when viewed from the front of the light source unit U40 (lens-diffuser sheet laminate 42) (see Figure 1).

[0066] Furthermore, as shown in an enlarged view in Figure 5, the translucent diffusing material sheet 44 has a structure in which a light-diffusing layer 44b of a predetermined thickness, in which transparent fine particles 45 with a particle size of 1 μm to 30 μm are dispersed in a transparent binder 46, is laminated and integrated on the front surface of a transparent resin base sheet 44a of a predetermined thickness. Light incident on the back surface of the diffusing material sheet 44 is diffused in various directions as it passes through the light-diffusing layer 44b on the front side of the diffusing material sheet 44, and thus emitted from the front surface of the diffusing material sheet 44 as diffused light (see Japanese Patent Application Publication No. 2017-83885).

[0067] In this embodiment, the light guided by the lens 43 is directed to the diffusing material sheet 44 via the laser-welded portion 50, which is a decorative portion (translucent joint), causing the entire laser-welded portion 50 to emit light, and the predetermined letters (ABC) formed by the entire laser-welded portion 50 to appear.

[0068] More specifically, on the outer surface of the lens 43, which is a light guide member, excluding the laser-welded portion 50 with the diffuser sheet 44, there is always a layer of air, including the interface L between the lens 43 and the diffuser sheet 44. Therefore, the light from the LED 47 that enters the lens 43 from the light incident portion 43a undergoes repeated total internal reflection without leakage at the front and back surfaces of the lens 43 (the interface where the refractive index changes abruptly), and is guided through the lens 43.

[0069] On the other hand, since there is no air (layer) at the laser-welded portion 50, which is the joint between the lens 43 and the diffuser sheet 44, the light guided by the lens 43 is directed to the diffuser sheet 44 via the laser-welded portion 50 and emitted as diffused light from the front surface of the diffuser sheet 44 (see Figure 4).

[0070] In other words, when the daytime running lamp 40 (light source unit U40) is lit, only the laser-welded portion 50 emits light, and the predetermined letters (ABC) formed by the laser-welded portion 50 appear as a pattern (decorative pattern) on the surface of the lens / diffuser sheet laminate 42 (see reference numeral 50, indicated by the dashed line in Figure 1).

[0071] Furthermore, since the translucent diffuser sheet 44 on which the fine particles 45 are dispersed is not transparent, when the daytime running lamp 40 is not lit, the entire diffuser sheet 44 exhibits a uniform color, and the predetermined pattern (decorative pattern) formed by the laser-welded part 50, which is the decorative part, does not become visible on the diffuser sheet 44. As a result, the appearance of the daytime running lamp 40 is improved, and the appearance of the headlamp 10 is also improved accordingly.

[0072] Furthermore, in this embodiment, the laser-welded portion 50 is formed across the space between the base sheet 44a and the lens 43, excluding the light diffusion layer 44b of the diffusion material sheet 44.

[0073] In other words, if the laser-welded portion 50a is formed to extend from the lens 43 to the light diffusion layer 44b of the diffusion material sheet 44, then when the region including the interface L between the diffusion material sheet 44 and the lens 43 is laser-welded, not only the base sheet 44a but also the light diffusion layer 44b (the fine particles 45 dispersed within it) may melt, potentially impairing the light diffusion function of the diffusion material sheet 44 (light diffusion layer 44b).

[0074] However, in this embodiment, the laser-welded portion 50 spans between the base sheet 44a and the lens 43, excluding the light-diffusing layer 44b of the diffuser sheet 44, and the light-diffusing layer 44b does not constitute the laser-welded portion 50. That is, the light-diffusing layer 44b of the diffuser sheet 44 is not affected by the heat when the interface L between the diffuser sheet 44 and the lens 43 is laser-welded (the effect of melting even the fine particles 45 dispersed in the light-diffusing layer 44b), and the form of the diffuser sheet 44 (light-diffusing layer 44b), in which transparent fine particles 45 are dispersed in the binder 46, is reliably maintained even after laser welding.

[0075] Therefore, when the daytime running lamp 40 (light source unit U40) is lit, the laser-welded portion 50, which is a joint constituting the decorative portion, emits light reliably and uniformly, and the predetermined characters (ABC) formed by the laser-welded portion 50 appear clearly as a pattern (decorative pattern) on the surface of the lens / diffusing material sheet laminate 42 (see reference numeral 50, indicated by the dashed line in Figure 1).

[0076] Next, based on Figure 6, the process of forming a laser-welded portion 50, which is a decorative portion extending along the interface L between the diffuser sheet 44 and the lens 43 of the lens-diffuser sheet laminate 42, will be described.

[0077] First, a diffusion material sheet 44 is laminated on a horizontally positioned lens 43 so that the base material sheet 44a faces the lens 43. The entire upper, lower, left, and right side edges of the laminated lens 43 and diffusion material sheet 44 are then fixed and held in place by a frame member 49 (see Figure 4), integrating the lens 43 and diffusion material sheet 44 into a lens-diffusion material sheet laminate 42.

[0078] Next, as shown in Figure 6, the lens-diffuser sheet laminate 42 is supported by the base 55 with the lens 43 side facing upwards. Furthermore, a translucent glass lens retainer 56 is placed on top of the lens-diffuser sheet laminate 42 to apply pressure between the lens 43 and the diffuser sheet 44, holding them in place so that no gap is formed at the interface L between the lens 43 and the diffuser sheet 44.

[0079] Next, by scanning the laser irradiation section (laser beam) 60 of a low-power laser irradiation device from above the lens / diffuser sheet laminate 42 in a manner that traces a predetermined pattern (letters A, B, C), the region along the interface L between the diffuser sheet 44 and the lens 43 of the lens / diffuser sheet laminate 42 is laser-welded, forming a laser-welded section 50, which is a decorative section that straddles the interface L between the diffuser sheet 44 and the lens 43.

[0080] More specifically, the laser beam can be any of the following: a semiconductor laser (wavelength 645-940 nm), an ND:YAG laser (wavelength 1000 nm), or a CO2 laser (wavelength 9600, 10600 nm). Furthermore, the base sheet 44a of the diffusing material sheet 44 is composed of a transparent resin containing, for example, a light absorber (Patent No. 4857887) consisting of a dioxazinaphthopentacene compound of a specific structure.

[0081] Then, when laser light (wavelength around 1000 nm) is irradiated so that the interface L between the diffusion material sheet 44 and the lens 43 becomes the focal point, the base sheet (transparent resin containing a light absorber) 44a of the diffusion material sheet 44 generates heat, and this heat is transferred to the lens 43, causing the region along the interface L between the diffusion material sheet 44 (base sheet 44a) and the lens 43 to melt, forming a laser-welded area 50.

[0082] Furthermore, the base 55 has through holes 55a that extend vertically, corresponding to the area scanned by the laser irradiation unit (laser light) 60 of the laser irradiation device. The laser light irradiated from the laser irradiation unit 60 is not 100% absorbed by the light-absorbing transparent resin that makes up the base sheet 44a. These holes are designed to suppress the problem of the base 55 generating heat due to the laser light that is not absorbed by the base sheet 44a, causing the diffusion material sheet 44 and the base 55 to fuse together.

[0083] Furthermore, by arbitrarily setting the scanning pattern of the laser irradiation unit (laser light) 60 of the laser irradiation device, a desired decorative pattern can be formed at the interface L between the diffuser sheet 44 and the lens 43 of the lens / diffuser sheet laminate 42. In other words, there is a high degree of freedom in the laser-welded portion (decorative pattern) 50 that can be formed on the lens 43.

[0084] Furthermore, in the first embodiment of the present invention, the lens 43, which is a light guide member, is generally made of PMMA (acrylic resin) or PC (polycarbonate) because it has excellent transparency (transmittance) and excellent heat resistance that can withstand the temperature rise caused by light guidance.

[0085] On the other hand, while PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene), PC (polycarbonate), polyester, and polyamide are widely known materials for the base sheet 44a (see Japanese Patent Application Publication No. 2017-83885), in this embodiment, considering compatibility with the material of the lens 43 (PMMA or PC), it is composed of either PMMA (acrylic resin), PC (polycarbonate), or polyester.

[0086] Furthermore, the fine particles 45 dispersed in the light diffusion layer 44b are made of polystyrene resin with an average particle size of 1 μm to 30 μm and a glass transition temperature (Tg) of 90°C or higher. On the other hand, the binder 46 that holds the fine particles 45 is a transparent resin with a glass transition temperature (Tg) of 90°C to 140°C. Acrylic resin is used because it has good adhesion to the fine particles 45, as well as transparency and refractive index.

[0087] In other words, in this embodiment, as described above, the lens 43 and the diffuser sheet 44 (base sheet 44a) are made of compatible resin, and by irradiation with laser light, the region along the interface L between the diffuser sheet 44 (base sheet 44a) and the lens 43 melts smoothly, making it easy to form a laser-welded portion 50 that spans the interface L between the diffuser sheet 44 (base sheet 44a) and the lens 43.

[0088] In particular, since the base sheet 44a of the diffusion material sheet 44 is very thin, as will be described later, a low-power laser irradiation device is required for laser welding between the base sheet 44a of the diffusion material sheet 44 and the lens 43. However, since the melting temperatures of the lens 43, which is made of a compatible resin, and the diffusion material sheet 44 (base sheet 44a) are almost the same, a laser-welded portion 50 spanning the interface L between the diffusion material sheet 44 (base sheet 44a) and the lens 43 can be accurately formed by irradiation with laser light.

[0089] Furthermore, in the first embodiment of the present invention, for the following reasons, the thickness of the lens 43 is set to 1.0 mm or more and less than 20 mm, the thickness of the diffusion material sheet 44 is set to 100 μm or more and 1.5 mm or less, and the thickness of the base sheet 44a is set to 50 μm or more and 1.0 mm or less.

[0090] The light emitted from the LED 47 has directionality (diffusion angle), and if the thickness of the lens 43 is less than 1.0 mm, it is difficult to get the light source into the lens 43 (the incidence efficiency of the light source at the light incidence part 43a on the side of the lens 43 is poor). Also, in order to ensure the rigidity and strength of the lens 43, it is desirable for the thickness of the lens 43 to be 1.0 mm or more.

[0091] On the other hand, if the thickness of the lens 43 exceeds 20 mm, the number of times the light incident on the lens 43 is reflected within the lens 43 increases, and the relative light guide distance becomes longer. As a result, the energy loss of the light guided within the lens 43 increases, and the amount of light guided from the laser-welded part 50 to the diffuser sheet 44 decreases relative to the amount of light incident on the lens 43. Consequently, the ratio of the amount of light emitted from the diffuser sheet 44 to the amount of light incident on the lens 43 decreases. In addition, in order to uniformly incident the light from the LED 47 across the entire lens 43, which has a large light guide cross-sectional area, it is necessary to increase the number of LEDs 47 or increase the light intensity (output) of the LEDs 47, which increases costs. Furthermore, as the space for housing the daytime running lamp light source unit U40 in the lamp chamber S increases in both the front and rear directions, the lamp body 12 becomes larger, so it is desirable that the thickness of the lens 43 be 20 mm or less. Therefore, the thickness of the lens 43 is set to be between 1.0 mm and 20 mm.

[0092] Furthermore, the laser-welded portion 50, which is a joint constituting the decorative portion, is formed by the melting of the region including the interface L between the diffuser sheet 44 and the lens 43 by irradiation with laser light. However, if the output of the laser light is too high, the diffuser sheet 44, which is thinner than the lens 43, may be damaged, impairing the light diffusion function of the diffuser sheet 44 corresponding to the laser-welded portion 50, or the surface of the diffuser sheet 44 may become wavy due to the heat, impairing the smoothness of the surface of the laser-welded portion 50, which may result in the decorative portion (decorative pattern) not emitting light uniformly when lit, or a decrease in the appearance of the lens 43 when not lit.

[0093] Therefore, when irradiating with laser light, it is necessary to adjust the output and irradiation time of the laser light so that the diffusion material sheet 44 is not damaged, the interface L between the diffusion material sheet 44 and the lens 43 reaches an appropriate melting temperature, the region spanning the interface L between the diffusion material sheet 44 and the lens 43 is smoothly welded, and the surface of the diffusion material sheet 44 does not become warped by heat, thus preventing the smoothness of the surface of the laser-welded portion 50 from being impaired.

[0094] Furthermore, if the thickness of the diffusion material sheet 44 is less than 100 μm, it is difficult to laser-weld the diffusion material sheet 44 and the lens 43 without damaging the diffusion material sheet 44 and while maintaining the smoothness of its surface.

[0095] On the other hand, if the thickness of the diffusion material sheet 44 exceeds 1.5 mm, the rigidity of the diffusion material sheet 44 increases, and in the case of a curved shape of the lens 43, the diffusion material sheet 44 cannot follow the curved shape of the lens surface, and a gap is formed between the lens 43 and the diffusion material sheet 44. This gap reduces the heat transfer efficiency in the laser light irradiation area and suppresses the rise in temperature in the laser light irradiation area, thus hindering smooth laser welding of the area including the interface L between the diffusion material sheet 44 and the lens 43. Therefore, the thickness of the diffusion material sheet 44 is set to be between 100 μm and 1.5 mm.

[0096] Furthermore, as shown in Figure 5, the diffusion material sheet 44 has a structure in which a light diffusion layer 44b in which fine particles 45 are dispersed is laminated and integrated onto a resin base sheet 44a. It is desirable that the light diffusion layer 44b of the diffusion material sheet 44 in the laser welding section 50 is not affected by the heat generated when the diffusion material sheet 44 and the lens 43 are laser-welded. However, if the thickness of the base sheet 44a is less than 50 μm, it is difficult to adjust the laser light output and irradiation time so that the interface L between the base sheet 44a and the lens 43 reaches an appropriate melting temperature, while the light diffusion layer 43b remains below its melting temperature.

[0097] On the other hand, if the thickness of the base sheet 44a exceeds 1.0 mm, the thickness of the light diffusion layer 44b becomes less than 0.5 mm compared to the desirable thickness of the diffusion material sheet 44 (1.5 mm or less), which reduces the number of fine particles 45 dispersed in the light diffusion layer 44b, potentially resulting in insufficient light diffusion function of the diffusion material sheet 44 (light diffusion layer 44b). Furthermore, if the thickness of the base sheet 44a exceeds 1.0 mm, the rigidity of the diffusion material sheet 44 increases, and in the case of a curved lens 43, the diffusion material sheet 44 cannot follow the curved lens surface shape. Therefore, the thickness of the base sheet 44a is set to be between 50 μm and 1.0 mm.

[0098] In the first embodiment described above, as shown in Figures 4 and 5, the translucent lens 43, which is a light guide member constituting the light source unit U40 for the daytime running lamp 40, is formed in a flat plate shape. However, as shown in Figures 7(a) and 7(b), even if the translucent lenses 43A and 43B, which are light guide members, are formed in a curved shape with a concave or convex shape on the surface side, the laser-welded decorative parts 50A and 50B can be formed in the region along the interface L between the diffusion material sheets 44 and 44 and the lenses 43A and 43B, respectively.

[0099] In more detail, when diffuser sheets 44, 44 are laminated onto lenses 43A, 43B with their concave or convex curved surfaces facing upwards, the diffuser sheets 44, 44 (base sheets 44a, 44a), which are formed to be very thin with a thickness of 100 μm to 1.5 mm (50 μm to 1.0 mm), can conform to the shape of the curved surface of the lenses 43A, 43B.

[0100] Then, the entire upper, lower, left, and right side edges of the laminated lens 43A and diffusion material sheet 44, and the laminated lens 43B and diffusion material sheet 44 are fixed and held in place by frame members 49, 49 (see Figure 4), and integrated as lens / diffusion material sheet laminates 42A and 42B, respectively.

[0101] Next, as shown in Figures 7(a) and (b), the lens-diffuser sheet laminates 42A and 42B are supported by the bases 55A and 55B with the lenses 43A and 43B facing upwards. The workpiece mounting surfaces 55A1 and 55B1 of the bases 55A and 55B are formed with curved surfaces that match the concave or convex curved surfaces of the light guide members, the lenses 43A and 43B. Therefore, the lens-diffuser sheet laminates 42A and 42B placed on the workpiece mounting surfaces 55A1 and 55B1 of the bases 55A and 55B are held in a form where there are no gaps between the lenses 43A and 43B and the diffuser sheets 44 and 44.

[0102] Furthermore, glass translucent lens retainers 56A and 56B are placed on top of the lens / diffusing sheet laminates 42A and 42B, respectively, and pressure is applied between the lenses 43A and 43B and the diffusion sheets 44 and 44, holding them in place so that no gap is formed at the interface L between the lenses 43A and 43B and the diffusion sheets 44 and 44.

[0103] Then, by scanning the laser irradiation section (laser beam) 60 of a low-power laser irradiation device from above the lenses 43A and 43B in a manner that traces a predetermined pattern (letters A, B, C), laser-welded sections 50A and 50B, which are decorative sections extending along the interface L between the diffuser sheets 44, 44 of the lens-diffuser sheet laminates 42A and 42B and the lenses 43A and 43B, can be formed, respectively.

[0104] In the first embodiment of the present invention, the base sheet 44a of the diffusion material sheet 44 is made of a transparent resin containing a light absorber (Japanese Patent No. 4857887) consisting of a dioxazinaphthopentacene compound of a specific structure. When irradiated with laser light (wavelength around 1000 nm), the light absorber generates heat, causing the region along the interface L between the translucent diffusion material sheet 44 (base sheet 44a) and the translucent lens 43 to melt, forming a laser-welded portion 50. However, even if the translucent diffusion material sheet 44 (base sheet 44a) is made of a resin that does not contain a light absorber, it can still be laser-welded to the laminated translucent resin lens 43.

[0105] That is, the method of forming a laser-welded portion 50 between the lens 43 and the diffuser sheet 44 (base sheet 44a) by laser welding the laminated translucent resin lens 43 and the translucent resin diffuser sheet 44 (base sheet 44a) is not limited to the method shown in this embodiment (a method in which the base sheet 44a of the diffuser sheet 44 is made of a transparent resin containing a light absorber), but may also be used without a light absorber, for example, the following method.

[0106] For example, as described in Japanese Patent No. 4104073, by sandblasting or etching, minute irregularities are formed on the surface (lens 43 side) of the diffuser sheet 44 (base sheet 44a), and by irradiating laser light (wavelength around 1000 nm) so as to focus on the interface between the diffuser sheet 44 (base sheet 44a) and the lens 43, the laser light is absorbed by the irregular surface of the diffuser sheet 44 (base sheet 44a), causing heat generation and melting. The lens 43 also melts due to heat conduction, and a laser-welded portion 50 can be formed in the region along the interface between the diffuser sheet 44 (base sheet 44a) and the lens 43.

[0107] Furthermore, by irradiating the interface between the diffusion material sheet 44 (base sheet 44a) and the lens 43 with long-wavelength 2000 nm laser light so as the focal point, a laser-welded portion 50 can be formed in the region along the interface between the diffusion material sheet 44 (base sheet 44a) and the lens 43.

[0108] Figures 8 to 10 show a second embodiment of the present invention. Figure 8 is a horizontal cross-sectional view of the light source unit for a daytime running lamp, which is the main part of the invention (corresponding to Figure 4). Figure 9 is an enlarged cross-sectional view of the joint (translucent adhesive layer) that joins and integrates the diffuser sheet and the lens (corresponding to Figure 5). Figures 10(a) and 10(b) are explanatory diagrams of the bonding process between the diffuser sheet and the lens (the process of forming a translucent adhesive layer between the diffuser sheet and the lens).

[0109] In the first embodiment described above, the diffuser sheet 44 and lens 43 constituting the lens-diffuser sheet laminate 42 are joined and integrated by a laser-welded portion 50 that constitutes a decorative portion and extends along the interface L of the two 44 and 43, as shown in Figures 4 and 5. In this second embodiment, however, as shown in Figures 8 and 9, the diffuser sheet 44 and lens 43 constituting the lens-diffuser sheet laminate 42C are joined and integrated by a translucent adhesive layer 70 that is a translucent joint portion that constitutes a decorative portion and extends along the interface L1 of the two 44 and 43. The translucent adhesive layer 70 is made of a translucent acrylic two-component adhesive and extends to form predetermined letters (ABC in this embodiment) when the light source unit U40 (lens-diffuser sheet laminate 42) is viewed from the front.

[0110] In other words, the translucent adhesive layer 70, which is the joint that joins and integrates the diffuser sheet 44 and the lens 43, functions as a translucent joint that guides the light guided by the lens 43 to the diffuser sheet 44. More specifically, the translucent adhesive layer 70, which is the translucent joint that joins and integrates the diffuser sheet 44 and the lens 43, is in close contact with the diffuser sheet 44 and the lens 43, respectively, and there are no interfaces between the diffuser sheet 44, the translucent adhesive layer 70, and the lens 43 where air (layers) exist. Therefore, the light guided by the lens 43, which is a light guide member, is guided to the diffuser sheet 44 via the translucent adhesive layer 70 and emitted as diffused light from the front surface of the diffuser sheet 44 (see Figure 8).

[0111] Therefore, when the daytime running lamp 40 is illuminated, the translucent adhesive layer 70, which is the joint constituting the decorative part, emits light reliably and uniformly, and the predetermined letters (ABC) formed by the translucent adhesive layer 70 on the surface of the lens / diffuser sheet laminate 42 appear to stand out as a pattern (decorative pattern).

[0112] Furthermore, an opaque adhesive layer 72 of a predetermined width is formed along the inner side of the top, bottom, left, and right side edges of the lens / diffuser sheet laminate 42C, with the same thickness as the translucent adhesive layer 70. This holds the diffuser sheet 44 and the lens 43 parallel to each other, and the entire lens / diffuser sheet laminate 42C is integrated with a uniform thickness. The opaque adhesive layer 72 is made of a black or gray urethane, silicone, or epoxy adhesive that is effective in preventing light leakage.

[0113] Furthermore, a rectangular frame member 49 with a U-shaped cross-section is provided on the side edge of the lens / diffusing material sheet laminate 42C to prevent light guided by the lens 43 from leaking out from the side edge of the lens, so that light guided by the lens 43 does not leak out from the side edge of the lens / diffusing material sheet laminate 42C.

[0114] Next, the process of forming a translucent adhesive layer 70, which is a decorative portion extending along the interface L1 between the lens and diffuser sheet laminate 44 and the lens 43 of the lens and diffuser sheet laminate 42C, and further forming an opaque adhesive layer 72 of a predetermined width along the inside of the upper, lower, left, and right side edges of the lens and diffuser sheet laminate 42C will be described.

[0115] First, as shown in Figure 10(a), the adhesive injection unit 71 of the first adhesive application device is scanned from above the horizontally positioned lens 43 to trace a predetermined pattern (in this embodiment, the letters A, B, C) and apply a translucent adhesive (translucent acrylic two-component adhesive) 70a to a predetermined position on the surface of the lens 43.

[0116] Next, the adhesive injection section 73 of the second adhesive application device is scanned to apply opaque adhesive 72a along the side edge of the lens 43.

[0117] Next, as shown in Figure 10(b), when the diffuser sheet 44 is pressed in a manner that keeps it parallel to the adhesive coating surface of the lens 43, the translucent adhesive 70a and opaque adhesive 72a between the diffuser sheet 44 and the lens 43 are crushed, causing the translucent adhesive layer 70 formed along the interface L1 between the diffuser sheet 44 and the lens 43 to form a predetermined decorative pattern. At the same time, the opaque adhesive layer 72 formed along the side edges of the diffuser sheet 44 and the lens 43 cooperates with the translucent adhesive layer 70 to fix and hold the diffuser sheet 44 and the lens 43, thereby integrating them as a lens-diffuser sheet laminate 42C.

[0118] Furthermore, by arbitrarily setting the scanning pattern of the adhesive injection section 71 of the first adhesive application apparatus, a desired decorative pattern can be formed on the lens / diffuser sheet laminate 42C. In other words, there is a high degree of freedom in the translucent adhesive layer (decorative pattern) 70 that can be formed on the lens 43.

[0119] According to this second embodiment, it is possible to provide a vehicle lighting device in which the decorative portion (translucent adhesive layer) 70 on the lens 43, which is a light guide member, is easily formed, and the degree of freedom in the decorative portion (decorative pattern that appears when lit) 70 that can be formed is excellent.

[0120] In the first and second embodiments described above, embodiments in which the present invention is applied to a daytime running lamp 40 were explained, but the present invention can also be applied to clearance lamps and other indicator lights. [Explanation of Symbols]

[0121] 10. Automotive headlamps with integrated daytime running lights. 12 Lamp body 14 Front cover S light room U10 Light source unit for high beam formation 15 Metal base 16. Light source: LED alloy 16a LED chip 16b LED board 17 Lens holder 18 Projection lens U20 Light source unit for low beam formation 20 Lens Holder 22. Light source: LED alloy 22a LED chip 22b LED board 24 Reflectors 25 Shades for cutoff line formation 26 Projection lens 27 Extension Reflector 27a,27b,27c opening 30 Aiming Mechanism 32 Aiming Screws 34 Nut component 40 Daytime Running Lights U40 Light source unit for daytime running lamps 41 cases 42, 42A, 42B, 42C Lens / diffusing material sheet laminate 43. Lens, which is a light guide component. 43a Light incidence part 44 Diffusion material sheet 44a Base sheet 44b Light Diffusion Layer 45 Microparticles 46 Binders L,L1 Interface between diffusion material sheet and lens 47. LEDs as light sources 49 Frame members 50. Laser-welded decorative section 62 Laser irradiation section of laser irradiation device 70. Translucent adhesive layer, which is the decorative part. 72 Opaque adhesive layer 71 Adhesive injection section of the first adhesive supply device 73 Adhesive injection section of the second adhesive supply device

Claims

1. A vehicle lamp including a plate-shaped light-transmitting resin lens serving as a light-guiding member disposed within a lamp chamber so as to face the front of the lamp chamber, a light-transmitting resin diffusion material sheet laminated on the front side of the lens, and an LED serving as a light source disposed facing a light entrance portion on a side of the lens, and a decorative portion that emits light by the light guided by the lens is provided in a predetermined area of ​​the lens as viewed from the front, a light-transmitting joint extending along the interface between the diffusion sheet and the lens, bonding the diffusion sheet and the lens together, and guiding light from the lens to the diffusion sheet.

2. 2. The vehicle lamp according to claim 1, wherein the joint is formed by a laser welding part that spans an interface between the diffusion material sheet and the lens.

3. 3. The vehicle lamp according to claim 2, wherein the diffusion material sheet has a structure in which a light diffusion layer in which transparent microparticles are dispersed in a transparent binder is laminated and integrated onto the front surface of a transparent resin base sheet, and the laser welded portion is formed across the base sheet and the lens, excluding the light diffusion layer of the diffusion material sheet.

4. 4. The vehicle lamp according to claim 2, wherein the lens and the diffusion material sheet are made of a compatible resin.

5. The vehicle lamp according to claim 3 or claim 4 dependent on claim 3, characterized in that the lens has a thickness of 1.0 mm to 20 mm, the diffusion material sheet has a thickness of 100 μm to 1.5 mm, and the base sheet has a thickness of 50 μm to 1.0 mm.

6. 2. The vehicle lamp according to claim 1, wherein the joint portion is formed of a light-transmitting adhesive layer formed along an interface between the diffusion material sheet and the lens.

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