Vehicle lamp

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 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 including 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 a 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 in an annular shape with a sense of depth (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 that covers the front surface side of the molding resin layer 4."

[0005] Patent Document 3 (Example 3) describes a side turn signal lamp 201 equipped with a light guide lens 246 assembled to a door mirror 2. By forming a decorative portion 232 on the back surface of an inner lens 240 arranged along the front surface of the light guide lens 246, when lit, the light guiding in the light guide lens 246 is reflected at a reflection step 250 on the back surface of the lens 246 and exits from the front surface of the light guide lens 246. When the light is distributed through the inner lens 240 and the outer cover 14, a decorative pattern formed by the decorative portion 232 on the back surface of the inner lens 240 appears to float up. In [Background Art] and [Problems to be Solved by the Invention], in the description explaining the configurations of Patent Documents 1 to 3 respectively, reference numerals used in [Modes for Carrying Out the Invention] of each document are attached.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] The first problem is that in any of the prior patent documents 1 to 3, the lamp structure becomes complicated, such as the need to adopt a configuration that makes a predetermined decorative portion invisible when not lit.

[0008] Specifically, in Patent Document 1, the light guide plate 2 disposed on the front side of the reflector 4 is formed relatively thick, so that the concavo-convex light diffusion pattern 6 on the back surface of the light guide plate 2 cannot be seen through when not lit. However, if the light guide plate 2 is thin, for example, it is necessary to form a half mirror film on the front surface of the light guide plate 2.

[0009] Also, in Patent Document 2, a light shielding layer 5 is indispensable for suppressing the light emission in the regions other than the decoration part D when lit and making the entire region other than the decoration part D look uniform when not lit.

[0010] Also, in Patent Document 3, the half mirror film 230 on the front surface of the inner lens 240 is indispensable so that the decoration part 232 cannot be seen through when not lit.

[0011] The second problem is as follows.

[0012] In the above-mentioned Patent Document 1, since the decoration pattern (concavo-convex light diffusion pattern) 6 is formed by embossing, painting, printing or dot processing (see paragraph 0023), the types of patterns of the decoration patterns that can be formed are limited. Therefore, the degree of freedom of the decoration pattern that appears floating when lit is small.

[0013] In the above-mentioned Patent Document 2, the decoration film 8 is formed on the outer peripheral surface 4a of the molded resin layer 4 by insert molding (see paragraphs 0018 and 0019). Further, an annular second through hole 5b is formed in the black light shielding layer 5 on the back surface of the front plate 6 that covers the front of the decoration film 8, so that a decoration part (design part D) where the decoration film 8 appears to float in an annular shape is configured. For this reason, the number of processing steps for forming the decoration part (design part D) is large, and the types of patterns of the decoration part (design part D) that can be formed are limited, and the degree of freedom of the decoration pattern that appears floating when lit is small.

[0014] In the above-mentioned Patent Document 3, since the decoration part 232 is formed on the inner lens 240 by laser decoration or a mold (see paragraph 0053), the number of processing steps for forming the decoration part is large, and the types of patterns of the decoration part that can be formed are limited, and the degree of freedom of the decoration pattern that appears floating when lit is small.

[0015] The present invention has been made in view of the above-described problems of the prior art. 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 a lens as a light guide member only when lit. The second object of the present invention is to provide a vehicle lamp in which the formation of a decorative portion on a lens as a light guide member is easy and the degree of freedom of the decorative portion (decorative pattern that appears to float when lit) that can be formed is excellent.

Means for Solving the Problems

[0016] In order to achieve the first object, in a vehicle lamp according to an aspect of the present invention, in a lamp chamber, a plate-shaped translucent resin lens as a light guide member arranged so as to face the front of the lamp chamber, a translucent resin diffuser sheet laminated on the front side of the lens, and an LED as a light source arranged to face the light incident portion on the side surface of the lens are provided. In a vehicle lamp in which a decorative portion that emits light by the light guiding of the lens is provided in a predetermined region when the lens is viewed from the front, the decorative portion is configured by a translucent joint portion that extends along the interface between the diffuser sheet and the lens, joins and integrates the diffuser sheet and the lens, and guides the light guiding of the lens to the diffuser sheet.

[0017] (Operation) Minute particles are dispersedly arranged in the translucent resin diffuser sheet, and the light incident on the back surface of the sheet exits as diffused light from the front surface of the sheet.

[0018] And since the decorative portion (the decorative portion that emits light by the light guiding of the lens) provided in the predetermined region when the translucent lens is viewed from the front is configured by a translucent joint portion that extends along the interface between the diffuser sheet and the lens, joins and integrates the diffuser sheet and the lens, and guides the light guiding of the lens to the diffuser sheet, when the lamp is lit, only the joint portion (decorative portion) emits light, and a predetermined pattern (decorative pattern) formed by the joint portion (decorative portion) on the diffuser sheet appears to float.

[0019] Specifically, there is always air (layer) at the interface between the laminated plate-shaped two members. That is, since there is always air (layer) on the outer surface of the region of the plate-shaped 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 leaking light at the front and back surfaces of the lens (the interface where the refractive index changes abruptly), 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] In addition, since the translucent diffusion sheet itself in which the fine particles are dispersedly arranged is not see-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 formed at 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 of the lamp is simplified because the components such as the reflector behind the light guide plate, the light shielding layer that suppresses 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, are not required.

[0023] In addition, 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 laser light, the region that becomes a hard glassy (solid) state 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] And, in the laser welding part, which is a light-transmissive joint part that joins and integrates the diffusion sheet and the lens, there is no interface with air (layer). Therefore, the light guiding of the lens is guided to the diffusion sheet through the joint part (laser welding part), and is emitted as diffused light from the front surface of the diffusion sheet.

[0026] Therefore, when the lamp is lit, the laser welding part, which is a light-transmissive joint part that constitutes the decorative part and straddles the interface between the diffusion sheet and the lens, emits light uniformly, and on the diffusion sheet, a predetermined pattern (decorative pattern) formed by the laser welding part appears to float.

[0027] Also, if the laser irradiation part (laser light) of the laser irradiation device is scanned so as to trace a predetermined pattern (in the embodiment, the characters ABC), the area along the interface between the diffusion sheet and the lens is laser welded, and the laser welding part straddling the interface between the diffusion sheet and the lens forms a predetermined decorative pattern extending along the interface between the diffusion sheet and the lens. Therefore, the formation of the light-transmissive joint part (laser welding part) that constitutes the decorative part is simple and easy. Furthermore, by arbitrarily setting the scanning pattern of the laser irradiation part (laser light) of the laser irradiation device, a desired decorative pattern can be formed. That is, the degree of freedom of the laser welding part (decorative pattern) that can be formed on the lens is high.

[0028] According to the vehicle lamp of this aspect, a vehicle lamp is provided in which the formation of the decorative part (laser welding part) on the lens, which is a light guiding member, is easy, and moreover, the degree of freedom of the decorative part (decorative pattern that appears when lit) that can be formed is excellent.

[0029] In a vehicle lamp according to another aspect of the present invention, the diffusion sheet has a structure in which a light diffusion layer in which transparent fine particles are dispersed and arranged in a transparent binder is laminated and integrated on the front surface of a transparent resin base sheet, and the laser welding part may be formed across the base sheet excluding the light diffusion layer of the diffusion sheet and the lens.

[0030] (Effect) When the laser welding part extends to the light diffusion layer of the diffusion material sheet, when laser-welding the area including the interface between the diffusion material sheet and the lens, not only the base material sheet but also the light diffusion layer (the fine particles dispersed therein) will melt, and the light diffusion function of the diffusion material sheet (light diffusion layer) may be impaired.

[0031] However, in the vehicle lamp of this embodiment, the laser welding part extends between the base material sheet excluding the light diffusion layer of the diffusion material sheet and the lens, and the light diffusion layer does not constitute the laser welding part (the light diffusion layer is not included in the laser welding part).

[0032] That is, 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) when the area including the interface between the diffusion material sheet and the lens is laser-welded, and the form of the light diffusion layer in which "transparent fine particles are dispersed and arranged in the binder" is maintained even after laser welding.

[0033] Therefore, according to the vehicle lamp of this embodiment, when the lamp is lit, the laser welding part, which is a translucent joint part constituting the decorative part, emits light surely and uniformly, and a predetermined pattern (decoration pattern) formed by the laser welding part on the diffusion material sheet becomes visible.

[0034] In addition, in the vehicle lamp of another aspect of the present invention, The lens and the diffusion material sheet may be made of a compatible resin.

[0035] (Effect) Since the diffusion material sheet (base material sheet) is very thin, it is necessary to use a low-power laser light irradiation device for laser welding the diffusion material sheet (base material sheet) and the lens. However, since the melting temperatures of the lens made of a compatible resin and the diffusion material sheet (base material sheet) are almost the same, the area along the interface between the diffusion material sheet (base material sheet) and the lens melts smoothly by irradiation with laser light, and it is easy to form a laser welding part that straddles the interface between the diffusion material sheet (base material sheet) and the lens.

[0036] That is, according to the vehicle lamp of this aspect, the process of laser welding the diffusion material sheet and the lens can be smoothly performed so as to retain the light diffusion function of the diffusion material sheet.

[0037] In addition, in the vehicle lamp of 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 emitted light from the LED, which is a light source, has directivity (diffusion angle). When the thickness of the lens is less than 1.0 mm, it is difficult to make the light from the light source enter the lens (the incident efficiency of the light from the light source on the side surface of the lens is poor). Also, from the viewpoint of ensuring the rigidity strength of the lens, the thickness of the lens is preferably 1.0 mm or more.

[0039] On the other hand, when the thickness of the lens exceeds 20 mm, the number of times the light incident on the lens is repeatedly reflected in the lens increases and the relative light guiding distance becomes longer, so that the energy loss of light guiding in the lens increases. The amount of light guided from the laser welding part, which is the joint part, to the diffusion material sheet with respect to the incident light amount decreases, and the ratio of the light output amount from the diffusion material sheet to the light incident amount on the lens decreases. Also, in order to uniformly irradiate the entire lens with a large light guiding cross-sectional area with the light from the light source, it is necessary to increase the number of LEDs or increase the light amount (output) of the LEDs, which increases the cost. Also, since the length of the lamp chamber in the front-rear direction increases and the lamp becomes larger, the thickness of the lens is preferably 20 mm or less. Therefore, the thickness of the lens is preferably 1.0 mm or more and 20 mm or less.

[0040] In addition, the laser welding part is formed by melting the region along the interface between the diffusion material sheet and the lens by irradiation with laser light. If the output of the laser light is too high, the diffusion material sheet, which is thinner than the lens, will be damaged, the light diffusion function of the diffusion material sheet in the laser welding part will be impaired, the surface of the diffusion material sheet will undulate due to heat, the smoothness of the surface of the diffusion material sheet will be impaired, the decorative part (decorative pattern) will not emit light uniformly when lit, or the appearance of the lens when not lit will deteriorate.

[0041] Therefore, when laser welding, it is necessary to adjust the output and irradiation time of the laser beam 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 region spanning the interface between the diffusion material sheet and the lens can be smoothly welded, and the surface of the diffusion material sheet does not undulate due to heat and the smoothness of the surface of the laser welded portion is not impaired.

[0042] 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 surface of the diffusion material sheet.

[0043] On the other hand, when the thickness of the diffusion material sheet exceeds 1.5 mm, the rigidity of the diffusion material sheet increases. In the case where the lens has a curved shape, the diffusion material sheet cannot follow the curved surface shape of the lens, and a gap is formed between the diffusion material sheet and the lens. This gap reduces the heat transfer efficiency in the laser beam irradiation region and suppresses the temperature rise in the laser beam irradiation region, thus preventing smooth laser welding of the region including the interface between the diffusion material sheet and the lens. Therefore, it is desirable that the thickness of the diffusion material sheet be 100 μm or more and 1.5 mm or less.

[0044] Also, the diffusion material sheet has a structure in which a light diffusion layer is laminated and integrated with a base material sheet. It is desirable that the light diffusion layer of the diffusion material sheet is not affected by heat when laser welding the diffusion material sheet and the lens. However, when the thickness of the base material sheet is less than 50 μm, it is difficult to adjust the output and irradiation time of the laser beam so that the interface between the base material sheet and the lens reaches an appropriate melting temperature while the light diffusion layer is below the melting temperature.

[0045] On the one hand, when the thickness of the base sheet exceeds 1.0 mm, with respect to the desirable thickness of the diffusion sheet (1.5 mm or less), the light diffusion layer becomes less than 0.5 mm, the number of fine particles dispersed in the light diffusion layer decreases, and the light diffusion function of the diffusion sheet (light diffusion layer) becomes insufficient. Also, when the thickness of the base sheet exceeds 1.0 mm, the rigidity of the diffusion sheet increases, and in the case of a lens with a curved shape, the diffusion sheet cannot follow the curved lens surface shape. Therefore, the thickness of the base sheet is preferably 50 μm or more and 1.0 mm or less.

[0046] Also, in order to achieve the second object, in a vehicle lamp according to another aspect of the present invention, the joint portion constituting the decorative portion may be constituted by a translucent adhesive layer formed along the interface between the diffusion sheet and the lens.

[0047] (Function) The translucent adhesive layer, which is a joint portion that joins and integrates the diffusion sheet and the lens, functions as a joint portion that guides the light guiding of the lens to the diffusion sheet. Specifically, the translucent adhesive layer (joint portion) that joins and integrates the diffusion sheet and the lens is in close contact with the diffusion sheet and the lens respectively, and there is no interface where air (layer) exists between the diffusion sheet, the translucent adhesive layer, and the lens. For this reason, the light guiding of the lens is guided to the diffusion sheet through the translucent adhesive layer, and exits as diffused light from the front surface of the diffusion sheet.

[0048] Therefore, when the lamp is lit, the translucent adhesive layer, which is the joint portion constituting the decorative portion and is formed along the interface between the diffusion sheet and the lens, emits light uniformly, and a predetermined pattern (decoration pattern) formed by the translucent adhesive layer on the diffusion sheet appears to float.

[0049] Further, if a light-transmissive adhesive is applied to the surface of the lens so as to trace a predetermined pattern (in the embodiment, the characters ABC), and the diffuser sheet is pressed against the adhesive-applied surface of the lens, the light-transmissive adhesive between the diffuser sheet and the lens is crushed, so that a light-transmissive adhesive layer extending along the interface between the diffuser sheet and the lens forms a predetermined decorative pattern. Thus, the formation of the joint portion (light-transmissive adhesive layer) constituting the decorative portion is simple and easy. Further, by arbitrarily setting the scanning pattern of the adhesive application portion of the adhesive application device, a desired decorative pattern can be formed. That is, the degree of freedom of the light-transmissive adhesive layer (decorative pattern) that can be formed on the lens is also high.

[0050] According to the vehicle lamp of this aspect, a vehicle lamp is provided in which the formation of the decorative portion (light-transmissive adhesive layer) on the lens as the light guide member is easy, and the degree of freedom of the decorative portion (decorative pattern that appears to float when lit) that can be formed is excellent.

Advantages of the Invention

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

[0052] Further, a vehicle lamp is provided in which the formation of the decorative portion on the lens as the light guide member is easy, and the degree of freedom of the decorative portion (decorative pattern that appears to float when lit) that can be formed is excellent.

Brief Description of the Drawings

[0053]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0054] Hereinafter, embodiments of the present invention will be described.

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

[0056] In these figures, particularly in FIGS. 1 to 3, reference numeral 10 denotes an automotive headlamp incorporating a daytime running lamp 40 (the headlamp on the left side as viewed from the driver, i.e., the headlamp on the right side facing the front of the vehicle). A front cover 14 is assembled to the front opening of the lamp body 12, and a lamp chamber S is defined. Above the lamp chamber S, light source units U10 and U20 for the headlamp are provided adjacent to each other on the left and right. Below 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 includes a rectangular metal base 15 in a front view, an LED array 16 (an LED substrate 16b mounted with an LED chip 16a) which is a light source disposed inside 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 disposed at a predetermined position in front of the LED array 16 by the lens holder 17. The LED array 16 is arranged in a form in which the LED chip 16a faces forward.

[0058] On the other hand, the light source unit U20 is a light source unit for forming a low beam, and includes a metal base 15, a metal lens holder 20 fixed to the outside of the vehicle width direction on the front surface of the base 15 and extending forward, an LED array 22 (an LED substrate 22b mounted with an LED chip 22a) which is a light source disposed on the upper surface of the lens holder 20, a reflector 24 disposed on the upper surface of the lens holder 20 and covering the LED array 22, and a projection lens 26 disposed at a predetermined position in front of the LED array 22 and the reflector 24 by the lens holder 20. The LED array 22 is arranged in a form in which the LED chip 22a faces upward, and a shade 25 for forming a cut-off line in the low beam light distribution pattern 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 composed of heat radiation fins 28a and a cooling fan 28b are provided, and by discharging the heat generated by the LED arrays 16 and 22 which are light sources to the lamp chamber S, a decrease in the light emission efficiency of the LED arrays 16 and 22 is suppressed.

[0060] Between the metal base 15 and the rear wall 12a of the lamp body, there is an aiming mechanism 30 composed of three aiming screws 32 that penetrate the rear wall 12a of the lamp body and extend forward, and nut members 34 provided on the metal base 15 for engaging with the aiming screws 32. By rotating the aiming screws 32, the optical axes of the light source units U10 and U20 can be integrally tilted and adjusted in the vertical, horizontal, and left-right directions.

[0061] In the front of the lamp chamber S, an extension reflector 27 with an aluminum vapor deposition treatment on its surface is arranged. Openings 27a, 27b, and 27c corresponding to the light source units U10, U20, and U40 are formed in the extension reflector 27, which do not obstruct the emitted light from the light source units U10, U20, and U40 when each lamp is lit. Also, when all the lamps are not lit, by making the entire area around the light source units U10, U20, and U40 in the lamp chamber S appear the same color, the appearance of the automotive headlamp 10 is made better.

[0062] Since the extension reflector 27 is arranged inside the front cover 14 in the lamp chamber S, when the automotive headlamp 10 is viewed from the front, the inside of the lamp chamber S cannot be seen. However, in FIG. 1, to clarify the arrangement structure of the light source units U10, U20, and U40 in the lamp chamber S, the extension reflector 27 is shown by a two-dot chain line, and the light source units U10 and U20 integrated with the metal base 15, the aiming mechanism 30 (32, 34), and the light source unit U40 are shown so as to be seen through.

[0063] Also, as shown in FIGS. 1, 3, and 4, the light source unit U40 for the daytime running lamp 40 includes 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 plate-shaped translucent resin lens 43, which is a light guide member having a rectangular shape in front view, within a rectangular case 41 having an open front surface in front view, and an LED 47, which is a light source facing the light incident portion 43a (see FIG. 4) on the side surface of the lens 43. A front frame 48 having a rectangular opening 48a slightly smaller than the outer shape of the lens / diffuser sheet laminate 42 is fixed to the front opening of the case 41. The light source unit U40 is fixed, for example, by a bracket B (see FIG. 3) inside the bottom wall 12b of the lamp body and is arranged to face the front of the lamp chamber S.

[0064] Note that, on the upper, lower, left, and right side edges of the lens / diffuser sheet laminate 42, there is provided a rectangular frame member 49 having a U-shaped cross section that fixes and holds the lens 43 and the diffuser sheet 44 in a laminated form and prevents leakage from the lens side edges of the light guide of the lens 43. Reference numeral 49a in FIG. 4 is an opening formed at a position corresponding to the light incident portion 43a of the lens 43 in the frame member 49. The light emitted by the LED 47 enters the lens 43 from the light incident portion 43a exposed at this opening 49a.

[0065] As shown in FIG. 4, a laser welding portion 50, which is a decorative portion, is formed between the diffuser sheet 44 and the lens 43 of the lens / diffuser sheet laminate 42 along the interface L between the two members 44 and 43. The laser welding portion 50 is formed across the interface L between the diffuser sheet 44 and the lens 43, joins and integrates the diffuser sheet 44 and the lens 43, and functions as a translucent joint portion that guides the light guide of the lens 43 to the diffuser sheet 44. In this embodiment, the laser welding portion 50 extends so as to form a predetermined character ABC when the light source unit U40 (lens / diffuser sheet laminate 42) is viewed from the front (see FIG. 1).

[0066] In addition, as shown in an enlarged view in Fig. 5, the light-transmissive diffuser sheet 44 has a light diffusion layer 44b with a predetermined thickness in which transparent fine particles 45 with a particle size of 1 μm to 30 μm are dispersed and arranged in a transparent binder 46, laminated and integrated on the front surface of a transparent resin base sheet 44a with a predetermined thickness. When the light incident on the back surface of the diffuser sheet 44 passes through the light diffusion layer 44b on the front surface side of the diffuser sheet 44, it is diffused in various directions, so that it exits as diffused light from the front surface of the diffuser sheet 44 (see JP-A-2017-83885).

[0067] And in the present embodiment, the light guiding of the lens 43 is guided to the diffuser sheet 44 through the laser welding portion 50 which is a decorative portion (light-transmissive joint portion), so that the entire laser welding portion 50 emits light, and a predetermined character (ABC) formed by the entire laser welding portion 50 floats up.

[0068] Specifically, on the outer surface of the region of the lens 43, which is a light guiding member, excluding the laser welding portion 50 with the diffuser sheet 44, air (layer) always exists including the interface L between the lens 43 and the diffuser sheet 44. Therefore, the light of the LED 47 incident on the lens 43 from the light incident portion 43a is repeatedly totally reflected without leaking light at the front and back surfaces (interfaces where the refractive index changes abruptly) of the lens 43, and is guided through the lens 43.

[0069] On the other hand, since no air (layer) exists in the laser welding portion 50 which is the joint portion of the lens 43 with the diffuser sheet 44, the light guiding of the lens 43 is guided to the diffuser sheet 44 through the laser welding portion 50, and exits as diffused light from the front surface of the diffuser sheet 44 (see Fig. 4).

[0070] That is, when the daytime running lamp 40 (light source unit U40) is lit, only the laser welding portion 50 emits light, and a predetermined character (ABC) formed by the laser welding portion 50 appears to float as a pattern (decorative pattern) on the surface of the lens-diffuser sheet laminate 42 (see the reference numeral 50 indicated by the broken line in Fig. 1).

[0071] In addition, since the translucent diffuser sheet 44 in which the mitochondria 45 are dispersedly arranged itself cannot be seen through, when the daytime running lamp 40 is not lit, the entire diffuser sheet 44 exhibits a uniform color tone, and a predetermined pattern (decoration pattern) formed by the laser welding portion 50 which is a decorative portion does not appear on the diffuser sheet 44. Therefore, the appearance of the daytime running lamp 40 is improved, and accordingly, the appearance of the headlamp 10 is also improved.

[0072] Furthermore, in this embodiment, the laser welding portion 50 is formed so as to straddle between the base material sheet 44a excluding the light diffusion layer 44b of the diffuser sheet 44 and the lens 43.

[0073] That is, if the laser welding portion 50a is formed so as to straddle from the lens 43 to the light diffusion layer 44b of the diffuser sheet 44, when laser-welding the region including the interface L between the diffuser sheet 44 and the lens 43, not only the base material sheet 44a but also the light diffusion layer 44b (the mitochondria 45 dispersed therein) may be melted, and the light diffusion function of the diffuser sheet 44 (light diffusion layer 44b) may be impaired.

[0074] However, the laser welding portion 50 of this embodiment straddles between the base material sheet 44a excluding the light diffusion layer 44b of the diffuser sheet 44 and the lens 43, and the light diffusion layer 44b does not constitute the laser welding portion 50. That is, the light diffusion layer 44b of the diffuser sheet 44 is not affected by the heat (the influence that the mitochondria 45 dispersed in the light diffusion layer 44b are melted) when the interface L between the diffuser sheet 44 and the lens 43 is laser-welded, and the form of the diffuser sheet 44 (light diffusion layer 44b) in which "transparent mitochondria 45 are dispersedly arranged in the binder 46" is surely maintained even after laser welding.

[0075] Therefore, when the daytime running lamp 40 (light source unit U40) is lit, the laser welding part 50, which is the joint part constituting the decorative part, emits light surely and uniformly, and a predetermined character (ABC) formed by the laser welding part 50 on the surface of the lens / diffuser sheet laminate 42 appears clearly as a pattern (decorative pattern) (see the reference numeral 50 indicated by the broken line in FIG. 1).

[0076] Next, based on FIG. 6, a process of forming the laser welding part 50, which is a decorative part 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, the diffuser sheet 44 is laminated on the horizontally arranged lens 43 such that the base material sheet 44a faces the lens 43 side, and the entire upper, lower, left, and right side edges of the laminated lens 43 and diffuser sheet 44 are fixedly held by a frame member 49 (see FIG. 4), and the lens 43 and the diffuser sheet 44 are integrated as the lens / diffuser sheet laminate 42.

[0078] Next, as shown in FIG. 6, the lens / diffuser sheet laminate 42 is supported by a base 55 such that the lens 43 side is on top. Further, a glass light-transmitting lens retainer 56 is placed on the lens / diffuser sheet laminate 42 to press the space between the lens 43 and the diffuser sheet 44, and the interface L between the lens 43 and the diffuser sheet 44 is held so that no gap is formed.

[0079] Next, if the laser irradiation unit (laser light) 60 of a low-output laser irradiation device is scanned from above the lens / diffuser sheet laminate 42 so as to trace a predetermined pattern (character ABC), 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, and the laser welding part 50, which is a decorative part straddling the interface L between the diffuser sheet 44 and the lens 43, can be formed.

[0080] Specifically, as the laser beam, any of a semiconductor laser (wavelength 645 to 940 nm), an ND:YAG laser (wavelength 1000 nm), and a CO2 laser (wavelengths 9600 and 10600 nm) may be used. Further, as the base sheet 44a of the diffusing material sheet 44, for example, it is composed of a transparent resin containing a light absorber (Patent No. 4857887) made of a dioxadinanaphthopentacene compound having a specific structure.

[0081] Then, when a laser beam (wavelength around 1000 nm) is irradiated so that the interface L between the diffusing material sheet 44 and the lens 43 becomes the focal point, the base sheet (light absorber-containing transparent resin) 44a of the diffusing material sheet 44 generates heat, and the heat is transmitted to the lens 43, melting the region along the interface L between the diffusing material sheet 44 (base sheet 44a) and the lens 43 to form a laser welding portion 50.

[0082] Note that a through hole 55a extending vertically is formed in the base 55 corresponding to the region where the laser irradiation unit (laser beam) 60 of the laser irradiation device scans. The laser beam irradiated from the laser irradiation unit 60 is not 100% absorbed by the light absorber-containing transparent resin constituting the base sheet 44a, and the base 55 generates heat due to the laser beam not absorbed by the base sheet 44a, and this hole is for suppressing the problem that the diffusing material sheet 44 and the base 55 are welded together.

[0083] Further, by arbitrarily setting the scanning pattern of the laser irradiation unit (laser beam) 60 of the laser irradiation device, a desired decorative pattern can be formed on the interface L between the diffusing material sheet 44 and the lens 43 of the lens-diffusing material sheet laminate 42. That is, the degree of freedom of the laser welding portion (decorative pattern) 50 that can be formed on the lens 43 is high.

[0084] In the first embodiment of the present invention, the lens 43, which is a light guiding 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 due to light guiding.

[0085] On one hand, as materials for the base sheet 44a, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene), PC (polycarbonate), polyester, polyamide, etc. are widely known (see JP-A-2017-83885). However, in this embodiment, in consideration of the compatibility with the material of the lens 43 (PMMA or PC), it is composed of any one of PMMA (acrylic resin), PC (polycarbonate), and polyester.

[0086] Further, the fine particles 45 dispersed and arranged in the light diffusion layer 44b are made of polystyrene resin with an average particle size of 1 μm to 30 μm and having 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 or higher and 140°C or lower, has good adhesion to the fine particles 45, and an acrylic resin is used in terms of transparency and refractive index.

[0087] That is, in this embodiment, as described above, the lens 43 and the diffusion sheet 44 (base sheet 44a) are made of a compatible resin, and by irradiating with laser light, the region along the interface L between the diffusion sheet 44 (base sheet 44a) and the lens 43 melts smoothly, facilitating the formation of the laser welding portion 50 straddling the interface L between the diffusion sheet 44 (base sheet 44a) and the lens 43.

[0088] In particular, since the base sheet 44a of the diffusion sheet 44 is very thin as described later, when laser welding between the base sheet 44a of the diffusion sheet 44 and the lens 43, it is necessary to use a low-output laser light irradiation device. However, since the melting temperatures of the lens 43 and the diffusion sheet 44 (base sheet 44a) made of a compatible resin are almost the same, the laser welding portion 50 straddling the interface L between the diffusion sheet 44 (base sheet 44a) and the lens 43 can be accurately formed by irradiating with laser light.

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

[0090] The light emitted from the LED 47 has directivity (diffusion angle). When the plate thickness of the lens 43 is less than 1.0 mm, it is difficult to make the light source light incident on the lens 43 (the incident efficiency of the light source light at the light incident portion 43a on the side surface of the lens 43 is poor). Also, from the viewpoint of ensuring the rigidity strength of the lens 43, the plate thickness of the lens 43 is preferably 1.0 mm or more.

[0091] On the other hand, when the plate thickness of the lens 43 exceeds 20 mm, the number of times the light incident on the lens 43 is reflected inside the lens 43 increases and the relative light guiding distance becomes longer, so the energy loss of light guiding inside the lens 43 increases. The amount of light guided from the laser welding portion 50 to the diffusion sheet 44 with respect to the amount of light incident on the lens 43 decreases, and the ratio of the amount of light emitted from the diffusion sheet 44 with respect to the amount of light incident on the lens 43 decreases. Also, in order to uniformly irradiate the entire lens 43 with a large light guiding cross-sectional area with the light of the LED 47, it is necessary to increase the number of LEDs 47 or increase the light amount (output) of the LEDs 47, which increases the cost. In addition, since the accommodation space of the light source unit U40 for the daytime running lamp in the lamp chamber S becomes larger front and back, the lamp body 12 becomes larger. Therefore, the plate thickness of the lens 43 is preferably 20 mm or less. Therefore, the plate thickness of the lens 43 is set to be 1.0 mm or more and 20 mm or less.

[0092] In addition, the laser welding part 50, which is the joint part constituting the decorative part, is formed by melting the region including the interface L between the diffuser sheet 44 and the lens 43 by irradiating laser light. However, if the output of the laser light is too high, the diffuser sheet 44, which is thinner than the lens 43, will be damaged, and the light diffusion function of the diffuser sheet 44 corresponding to the laser welding part 50 will be impaired, or the surface of the diffuser sheet 44 will be wavy due to heat, damaging the smoothness of the surface of the laser welding part 50, resulting in concerns such as the decorative part (decorative pattern) not emitting light uniformly when lit or the appearance of the lens 43 when not lit deteriorating.

[0093] Therefore, when irradiating laser light, it is necessary to adjust the output and irradiation time of the laser light so that not only the diffuser sheet 44 is not damaged, but also the interface L between the diffuser sheet 44 and the lens 43 reaches an appropriate melting temperature, enabling the region straddling the interface L between the diffuser sheet 44 and the lens 43 to be smoothly welded, and also ensuring that the surface of the diffuser sheet 44 is not wavy due to heat and the smoothness of the surface of the laser welding part 50 is not impaired.

[0094] When the plate thickness of the diffuser sheet 44 is less than 100 μm, it is difficult to laser-weld the diffuser sheet 44 and the lens 43 without damaging the diffuser sheet 44 and maintaining the smoothness of its surface.

[0095] On the other hand, when the plate thickness of the diffuser sheet 44 exceeds 1.5 mm, the rigidity of the diffuser sheet 44 increases. In the case where the lens 43 has a curved shape, the diffuser sheet 44 cannot follow the curved lens surface shape, and a gap is formed between the lens 43 and the diffuser sheet 44. This gap reduces the heat transfer efficiency in the laser light irradiation region and suppresses the temperature rise in the laser light irradiation region, thereby preventing the smooth laser welding of the region including the interface L between the diffuser sheet 44 and the lens 43. Therefore, the plate thickness of the diffuser sheet 44 is set to be 100 μm or more and 1.5 mm or less.

[0096] Further, as shown in FIG. 5, the diffusing sheet 44 has a structure in which a light diffusing layer 44b in which fine particles 45 are dispersedly arranged is laminated and integrated with a resin base sheet 44a. It is desirable that the light diffusing layer 44b of the diffusing sheet 44 in the laser welding portion 50 is not affected by the heat when the diffusing sheet 44 and the lens 43 are laser welded. However, when the thickness of the base sheet 44a is less than 50 μm, while the interface L between the base sheet 44a and the lens 43 reaches an appropriate melting temperature, it is difficult to adjust the output and irradiation time of the laser beam so that the light diffusing layer 43b is below the melting temperature.

[0097] On the other hand, when the plate thickness of the base sheet 44a exceeds 1.0 mm, with respect to the desirable plate thickness of the diffusing sheet 44 (1.5 mm or less), the thickness of the light diffusing layer 44b becomes less than 0.5 mm, and the number of fine particles 45 dispersedly arranged in the light diffusing layer 44b decreases, which may result in an insufficient light diffusing function of the diffusing sheet 44 (light diffusing layer 44b). Further, when the plate thickness of the base sheet 44a exceeds 1.0 mm, the rigidity of the diffusing sheet 44 increases, and in the case where the lens 43 has a curved shape, the diffusing sheet 44 cannot follow the curved lens surface shape. Therefore, the plate thickness of the base sheet 44a is set to be 50 μm or more and 1.0 mm or less.

[0098] In the first embodiment, as shown in FIGS. 4 and 5, the light-transmissive 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 FIGS. 7(a) and 7(b), even if the light-transmissive lenses 43A and 43B, which are light guide members, are formed in a curved shape that is concave or convex on the surface side, laser welding portions 50A and 50B, which are decorative portions, can be respectively formed in the regions along the interfaces L between the diffusing sheets 44 and 44 and the lenses 43A and 43B.

[0099] Specifically, first, when the diffusion material sheets 44, 44 are each laminated on the lenses 43A, 43B with the concave or convex curved surfaces facing upward, the diffusion material sheets 44, 44 (base material sheets 44a, 44a) which are very thinly formed with a thickness of 100 μm or more and 1.5 mm or less (50 μm or more and 1.0 mm or less) can follow the shape conforming to the curved surfaces 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 respectively fixed and held by the frame members 49, 49 (see FIG. 4), and integrated into the lens-diffusion material sheet laminates 42A, 42B respectively.

[0101] Next, as shown in FIGS. 7(a) and 7(b), the lens-diffusion material sheet laminates 42A, 42B are supported by the bases 55A, 55B with the lens 43A, 43B sides facing upward. The work placement surfaces 55A1, 55B1 of the bases 55A, 55B are formed into curved surfaces that match the concave or convex curved surfaces of the lenses 43A, 43B which are light guiding members. For this reason, the lens-diffusion material sheet laminates 42A, 42B placed on the work placement surfaces 55A1, 55B1 of the bases 55A, 55B are held in a form where there is no gap between the lenses 43A, 43B and the diffusion material sheets 44, 44.

[0102] Furthermore, transparent glass lens retainers 56A, 56B are respectively placed on the lens-diffusion material sheet laminates 42A, 42B to pressurize the space between the lenses 43A, 43B and the diffusion material sheets 44, 44, and hold them so that no gap is formed at the interface L between the lenses 43A, 43B and the diffusion material sheets 44, 44.

[0103] Then, if the laser irradiation units (laser light) 60 of the low-output laser irradiation devices are respectively scanned from above the lenses 43A, 43B so as to trace a predetermined pattern (characters ABC), laser welding parts 50A, 50B which are decorative parts extending along the interface L between the diffusion material sheets 44, 44 and the lenses 43A, 43B of the lens-diffusion material sheet laminates 42A, 42B can be respectively formed.

[0104] In the first embodiment of the present invention, the base sheet 44a of the diffuser sheet 44 is made of a transparent resin containing a light absorber (Patent No. 4857887) composed of a dioxadina naphthopentaene compound with a specific structure. By irradiating laser light (near a wavelength of 1000 nm), the light absorber generates heat, melting the region along the interface L between the translucent diffuser sheet 44 (base sheet 44a) and the translucent lens 43, and forming a laser welding portion 50. However, even a translucent diffuser sheet 44 (base sheet 44a) made of a resin that does not contain a light absorber can be laser welded to the laminated translucent resin lens 43.

[0105] That is, the method of laser welding the laminated translucent resin lens 43 and the translucent resin diffuser sheet 44 (base sheet 44a) to form a laser welding portion 50 between the lens 43 and the diffuser sheet 44 (base sheet 44a) is not limited to the method shown in this embodiment (the method of making the base sheet 44a of the diffuser sheet 44 made of a light absorber-containing transparent resin), and methods that do not use a light absorber, for example, the following methods, may also be used.

[0106] For example, as described in Patent No. 4104073, by performing sandblasting treatment or etching treatment to form minute irregularities on the surface (lens 43 side) of the diffuser sheet 44 (base sheet 44a) and irradiating laser light (near a wavelength of 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) to generate heat and melt, and the lens 43 also melts by heat conduction, and a laser welding portion 50 can be formed in the region along the interface between the diffuser sheet 44 (base sheet 44a) and the lens 43.

[0107] Also, by irradiating laser light with a long wavelength of 2000 nm so as to focus on the interface between the diffuser sheet 44 (base sheet 44a) and the lens 43, a laser welding portion 50 can be formed in the region along the interface between the diffuser sheet 44 (base sheet 44a) and the lens 43.

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

[0109] In the above-described first embodiment, as shown in Figs. 4 and 5, the diffuser sheet 44 and the lens 43 that constitute the lens / diffuser sheet laminate 42 are joined and integrated by a laser welding portion 50 that forms a decorative portion and extends along the interface L between the two members 44 and 43. However, in this second embodiment, as shown in Figs. 8 and 9, the diffuser sheet 44 and the lens 43 that constitute the lens / diffuser sheet laminate 42C are joined and integrated by a light-transmissive adhesive layer 70, which is a light-transmissive joint portion that forms a decorative portion and extends along the interface L1 between the two members 44 and 43. The light-transmissive adhesive layer 70 is composed of a light-transmissive acrylic two-component adhesive and extends so as to form a predetermined character (ABC in the embodiment) when the light source unit U40 (lens / diffuser sheet laminate 42) is viewed from the front.

[0110] That is, the light-transmissive adhesive layer 70, which is a joint portion that joins and integrates the diffuser sheet 44 and the lens 43, functions as a light-transmissive joint portion that guides the light guided by the lens 43 to the diffuser sheet 44. Specifically, the light-transmissive adhesive layer 70, which is a light-transmissive joint portion that joins and integrates the diffuser sheet 44 and the lens 43, closely adheres to the diffuser sheet 44 and the lens 43, respectively, and there is no interface where air (layers) exist between the diffuser sheet 44, the light-transmissive adhesive layer 70, and the lens 43. For this reason, the light guided by the lens 43, which is a light guide member, is guided to the diffuser sheet 44 through the light-transmissive adhesive layer 70 and is emitted as diffused light from the front surface of the diffuser sheet 44 (see Fig. 8).

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

[0112] Also, on the inner sides of the upper, lower, left, and right side edges of the lens / diffuser sheet laminate 42C, an opaque adhesive layer 72 having a predetermined width is formed along the side edges with the same thickness as the translucent adhesive layer 70, so that the diffuser sheet 44 and the lens 43 are held parallel to each other and integrated as a lens / diffuser sheet laminate 42C having a uniform thickness throughout. The opaque adhesive layer 72 is composed of a urethane-based, silicone-based, or epoxy-based black or gray adhesive that is effective in preventing light leakage.

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

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

[0115] First, as shown in Fig. 10(a), from above the horizontally arranged lens 43, the adhesive injection part 71 of the first adhesive application device is scanned so as to trace a predetermined pattern (characters ABC in the embodiment), and a translucent adhesive (transmissive acrylic two-component adhesive) 70a is applied to a predetermined position on the surface of the lens 43.

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

[0117] Next, as shown in FIG. 10(b), if the diffuser sheet 44 is pressed in a form that holds it parallel to the adhesive application surface of the lens 43, the translucent adhesive 70a and the opaque adhesive 72a between the diffuser sheet 44 and the lens 43 are each crushed, so that a translucent adhesive layer 70 formed along the interface L1 between the diffuser sheet 44 and the lens 43 forms a predetermined decorative pattern, and an 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] Also, by arbitrarily setting the scanning pattern of the adhesive injection part 71 of the first adhesive application device, a desired decorative pattern can be formed on the lens-diffuser sheet laminate 42C. That is, the degree of freedom of the translucent adhesive layer (decorative pattern) 70 that can be formed on the lens 43 is also high.

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

[0120] In the above-described first and second embodiments, the embodiments in which the present invention is applied to the daytime running lamp 40 have been described, but the present invention can also be applied to clearance lamps and other marker lamps.

Explanation of reference numerals

[0121] 10 Automobile headlamp incorporating a daytime running lamp 12 Lamp body 14 Front cover S Lamp chamber U10 Light source unit for high beam formation 15 Metal base 16 LED alloy as a light source 16a LED chip 16b LED substrate 17 Lens Holder 18 Projection Lens U20 Light Source Unit for Forming Low Beam 20 Lens Holder 22 LED Alloy as Light Source 22a LED Chip 22b LED Substrate 24 Reflector 25 Shade for Forming Cut-off Line 26 Projection Lens 27 Extension Reflector 27a, 27b, 27c Apertures 30 Aiming Mechanism 32 Aiming Screw 34 Nut Member 40 Daytime Running Lamp U40 Light Source Unit for Daytime Running Lamp 41 Case 42, 42A, 42B, 42C Lens / Diffuser Sheet Laminate 43 Lens as Light Guide Member 43a Light Incident Portion 44 Diffuser Sheet 44a Base Sheet 44b Light Diffusion Layer 45 Fine Particles 46 Binder L, L1 Interface between Diffuser Sheet and Lens 47 LED as Light Source 49 Frame Member 50 Laser Welding Portion as Decorative Portion 62 Laser Irradiation Portion of Laser Irradiation Device 70 Translucent Adhesive Layer as Decorative Portion 72 Opaque Adhesive Layer 71 Adhesive Injection Portion of First Adhesive Supply Device 73 Adhesive Injection Portion of Second Adhesive Supply Device

Claims

1. In a lamp chamber, there are a plate-shaped light-transmitting resin lens which is a light guide member arranged to face directly forward of the lamp chamber, a diffusion material sheet made of light-transmitting resin laminated and arranged on the front side of the lens, and an LED which is a light source arranged to face directly the light incident portion on the side surface of the lens. In a vehicle lamp provided with a decorative portion that emits light by the light guide of the lens in a predetermined region when viewed from the front of the lens, the decorative portion extends along the interface between the diffusion material sheet and the lens, and is composed of a light-transmitting joint portion that joins and integrates the diffusion material sheet and the lens and guides the light guide of the lens to the diffusion material sheet. The vehicle lamp is characterized by this.

2. The vehicle lamp according to claim 1, wherein the joint portion is composed of a laser welding portion straddling the interface between the diffusion material sheet and the lens.

3. The diffusion material sheet has a structure in which a light diffusion layer in which transparent fine particles are dispersed and arranged in a transparent binder is laminated and integrated on the front surface of a transparent resin base material sheet. The laser welding portion is formed to straddle between the base material sheet excluding the light diffusion layer of the diffusion material sheet and the lens. The vehicle lamp according to claim 2 is characterized by this.

4. The vehicle lamp according to claim 2 or 3, wherein the lens and the diffusion material sheet are composed of compatible resins.

5. The vehicle lamp according to claim 3 or claim 4 dependent on claim 3, wherein the plate thickness of the lens is 1.0 mm to 20 mm, the plate thickness of the diffusion material sheet is 100 μm to 1.5 mm, and the plate thickness of the base material sheet is 50 μm to 1.0 mm.

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

Images