Lighting structure for vehicle

Abstract

The invention provides an illumination structure for a vehicle, which can enable window glass of the vehicle to emit light effectively. A lighting structure for a vehicle includes: a window glass having a main body having a laminated glass structure in which a first glass plate, an intermediate film, and a second glass plate are laminated, and a stepped portion including only the first glass plate; the lighting unit includes a plurality of light sources, a support body for supporting the light sources, and a light guide body for guiding light emitted from the light sources and causing the light to enter an end surface of the second glass plate at the boundary between the main body and the step portion, the light guide body including: a housing portion for housing the light sources and having a light receiving surface for receiving the light emitted from the light sources; a light-emitting surface facing an end surface of the second glass plate at a boundary between the main body and the stepped portion; and a light guide part which is disposed between the light receiving surface and the light emitting surface and guides the light received by the light receiving surface to a position away from the light source in the thickness direction of the window glass, the light source being sealed between the light guide body and the support body.

Description

Technical Field

[0001] The present invention relates to a lighting structure for a vehicle, and more particularly to a lighting structure for making a window glass (eg, roof glass) of a vehicle emit light. Background Art

[0002] In vehicles such as automobiles, various lighting structures are provided for the purpose of improving practicality and / or design. Sometimes, a window glass (glass window) is provided on the roof of a vehicle to serve as a skylight. As an example, Patent Document 1 describes a light-emitting vehicle glass window that uses a light-emitting diode or an optical fiber as a light source to make the window glass of a vehicle emit light.

[0003] Patent Document 1: Japanese Patent No. 5802684 Summary of the invention

[0004] In Patent Document 1, a light-emitting diode or optical fiber is provided on the end face or surface of a window glass (glass window) to make the window glass emit light. However, the inventors of the present invention have conducted research and found that in the case of such a structure, the utilization efficiency of the light emitted from the light source is low, and the energy efficiency is low relative to the lighting effect. In view of the above situation, the object of the present invention is to provide a lighting structure that can effectively utilize the emitted light and make the window glass emit light over a wide range.

[0005] The first structure of the present invention is a lighting structure for a vehicle that makes the window glass of the vehicle emit light, wherein the lighting structure has a window glass and at least one lighting unit, the window glass is a laminated glass obtained by laminating a first glass plate, an intermediate film, and a second glass plate in sequence, the window glass has: a main body having a laminated glass structure; and a step portion, when observed in the thickness direction, the step portion only includes the first glass plate of the first glass plate and the second glass plate, the lighting unit includes: a plurality of light sources; a support body that supports the light sources; and a light guide body The light emitted from the light source is guided so as to be incident on the end face of the second glass plate at the boundary between the main body and the step portion, and the light guide comprises: a housing portion that houses the light source and has a light receiving surface that receives the light emitted from the light source; a light emitting surface that is opposite to the end face of the second glass plate at the boundary between the main body and the step portion; and a light guiding portion that is arranged between the light receiving surface and the light emitting surface and guides the light received by the light receiving surface to a position away from the light source in the thickness direction of the window glass, and the light source is sealed between the light guide and the supporting body.

[0006] According to the lighting structure of the above structure, by making the light emitted from multiple light sources enter through the light guide, the window glass (for example, the roof glass) can be effectively illuminated. At this time, by appropriately designing the shape of the light guide part, the light emitted from the multiple light sources can be mixed to improve the luminous efficiency, and the light source can be protected by the sealed structure.

[0007] In the above-mentioned vehicle lighting structure, it can also be characterized in that the light guiding portion of the light guide body has: a first reflecting surface, which reflects the light incident on the light guide body from the light receiving surface; and a second reflecting surface, which reflects the light reflected by the first reflecting surface toward the light emitting surface, the first reflecting surface being a curved surface whose angle (θ1) formed by a surface tangent to the first reflecting surface in a cross section of the light guide body with respect to the light emitting surface becomes smaller as it approaches the light emitting surface, and the second reflecting surface is a curved surface whose angle (θ2) formed by a surface tangent to the second reflecting surface in a cross section of the light guide body with respect to the light emitting surface becomes larger as it approaches the light emitting surface.

[0008] According to the above-mentioned vehicle lighting structure, light incident on the window glass can be guided to a portion away from the end surface, and a wide area can be illuminated.

[0009] In the above-mentioned vehicle lighting structure, the step portion may be partially provided at the peripheral portion of the window glass, and the lighting unit may be at least partially accommodated in the step portion. By arranging the above-mentioned lighting structure at the peripheral portion of the window glass, the window glass can emit light in a wide range.

[0010] The lighting structure may be such that, in a cross section perpendicular to the surface of the window glass, light incident on the window glass at an incident angle of 20° or less accounts for 40% or more of the total luminous flux of the light source. This can improve light utilization efficiency.

[0011] According to the lighting structure of the present invention, compared with a case where a light source is directly arranged on an end surface of the window glass, the window glass can be made to emit light with high light emission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A vehicle lighting structure according to an embodiment of the present invention is shown. Figure 1 (A) is a bottom view viewed from the back side. Figure 1 (B) is a schematic side view.

[0013] Figure 2 yes Figure 1 This is an enlarged view of the portion shown in II in (A).

[0014] Figure 3 yes Figure 1(B) is an enlarged view of the portion shown in III.

[0015] Figure 4 It is shown Figure 1 A three-dimensional diagram of the structure of each part of the lighting unit provided in the lighting structure.

[0016] Figure 5 It shows that Figure 4 A top view of the lighting unit in an assembled state is shown.

[0017] Figure 6 It shows that Figure 4 A front view of the lighting unit shown in the assembled state.

[0018] Figure 7 yes Figure 5 A cross-sectional view of the portion shown along line VII-VII.

[0019] Figure 8 yes Figure 5 A cross-sectional view of the portion shown by line VIII-VIII.

[0020] Fig. 9 It is a cross-sectional view showing the cross-sectional structure of a step portion of a window glass.

[0021] Fig.10 The figure shows a simulation of the light source emitted from the lighting unit and incident on the Fig. 9 This is a diagram showing the optical path of light at the end face of the stepped portion.

[0022] Fig.11 is a cross-sectional view of an end portion of a lighting unit.

[0023] Description of symbols

[0024] 1: Vehicle lighting structure; 10: Window glass; 10a: Peripheral portion; 10b: Step portion; 10c: Main body; 10d: End surface; 11: First glass plate; 12: Second glass plate; 13: Intermediate film; 20: Lighting unit; 21: Wiring harness; 22: Power socket; 23: Light source (LED); 24: Support body (LED substrate); 25: Light guide; 25a: Upper surface; 25b: Light receiving surface; 25c: Storage portion; 25d: Light emitting surface; 25e: Light guide portion; 25g: First reflecting surface; 25h: Second reflecting surface; 26: Shell member; 27: Screw; 28: Film; 29: Adhesive tape. DETAILED DESCRIPTION

[0025] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0026] Figure 1(A) is a bottom view of a vehicle lighting structure 1 according to an embodiment of the present invention as viewed from the back side, Figure 1 (B) is a schematic side view of the same lighting structure 1. Figure 1 As shown in (A) and (B) of FIG. 1 , the lighting structure 1 includes: a window glass 10; and a lighting unit 20, which is arranged in a step portion (cutout portion) 10b partially provided at a peripheral portion 10a of the window glass 10. Figure 1 In the embodiment, four lighting units 20 are arranged at four step portions 10b, but the number of step portions 10b and lighting units 20 can be appropriately selected according to the size and shape of the window glass, the design of the lighting, etc. In addition, in order to make the window glass 10 emit light efficiently, a known scattering layer (not shown) can also be provided on the window glass 10.

[0027] Figure 2 yes Figure 1 An enlarged view of the portion shown in II in (A), Figure 3 yes Figure 1 The main body 10c of the window glass 10 adopts a laminated glass structure consisting of a first glass plate (outer glass plate) 11, a second glass plate (inner glass plate) 12, and an intermediate film 13. In a part of the peripheral portion 10a, the second glass plate 12 and the intermediate film 13 are cut away to provide a step portion 10b including only the first glass plate. The lighting unit 20 is arranged on the step portion 10b, fixed to the first glass plate 11, and connected to a power source (not shown) via a harness 21.

[0028] Figure 4 2 is a perspective view showing the structural components of the lighting unit 20. The lighting unit 20 includes: a support body (LED substrate) 24, which is connected to the wiring harness 21 through a power socket 22 and supports a plurality of (10 in the example) light sources 23 composed of LEDs; a light guide 25, which is arranged on the support body 24; and a housing member 26, which accommodates the support body 24. The support body 24 is fixed to the light guide 25 by screws 27, and the housing member 26 is also fitted into the light guide 25. The lighting unit 20 is fixed to the window glass 10 by means of a double-sided adhesive tape 29 attached to the upper surface 25a of the light guide. In addition, the housing member 26 is provided with an opening 26a for ventilation, and the opening 26a is sealed by a waterproof and breathable film 28.

[0029] Figure 5 is a top view of the assembled lighting unit. Figure 6 It is the main view. Figure 7 yes Figure 5 A cross-sectional view of the portion shown in VII-VII, Figure 8 yes Figure 5 A cross-sectional view of the portion shown in FIG. 8A - VIII-VIII. Figure 5 The length of the lighting unit 20 shown (along Figure 1 The size D and width W of the peripheral edge portion 10a of the window glass 10 are set according to the number of light sources 23 mounted. Figure 8 As shown, the light guide 25 has: a housing portion 25c, which houses the light source 23, and has a light receiving surface 25b for receiving light emitted from the light source 23; a light emitting surface 25d, which is aligned with the end surface ( Fig.10 10d); and a light guide portion 25e, which is arranged between the light receiving surface 25b and the light emitting surface 25d, and guides the light received by the light receiving surface 25b to a position away from the light source in the thickness direction of the window glass, and the light source 23 is sealed between the light guide 25 and the support body 24. In addition, hereinafter, the light receiving surface 25b, the light guide portion 25e, and the light emitting surface 25d are sometimes referred to as the lens portion 25f.

[0030] Fig. 9 1 is a diagram showing a cross-sectional structure near the step portion 10b of the window glass 10. Laminated glass for automobiles generally has the following structure: a first glass plate (outer glass plate) 11 and a second glass plate (inner glass plate) 12 made of a material with high transparency such as soda glass sandwich an intermediate film 13 made of polyvinyl butyral (PVB) or the like. In this embodiment, the main body 10c of the window glass 10 also adopts a laminated glass structure, but the second glass plate 12 and the intermediate film 13 are cut away from a part of the peripheral portion 10a of the window glass 10 to form the step portion 10b. The step portion 10b has only the first glass plate 11, and the lighting unit 20 is at least partially accommodated in a space (step portion space) 14 surrounded by the surface 11a of the first glass plate 11 and the end face 10d of the window glass 10 at the boundary between the step portion 10b and the main body 10c (i.e., the end face 13a of the intermediate film 13 and the end face 12a of the second glass plate 12). In order to use the window glass 10 as an illuminant, it is necessary to guide the light L1 incident on the second glass plate 12 while reflecting it on the surface 12b of the second glass plate 12 and the interface 12c between the second glass plate 12 and the intermediate film 13. As a result of studying the optical structure, the inventors of the present invention found that in order to guide the light, the incident angle θ of the light incident on the window glass 10 in the cross section perpendicular to the surface 12b of the second glass plate 12 and the end surface 10d of the window glass 10 facing the step portion 10b should be preferably adjusted to 30 degrees or less, and more preferably adjusted to 20 degrees or less. If the incident angle θ is set to a high angle, the incident light L2 is incident on the intermediate film 13, and is dissipated through the first glass plate depending on the angle, or when the incident light L3 is reflected on the interface 13b between the intermediate film 13 and the first glass plate 11, the proportion absorbed by the intermediate film 13 also increases. Therefore, an optical structure has been studied in which the incident angle of the light flux emitted from the light source is made 20 degrees or less as much as possible.

[0031] Fig.10 : This is a diagram showing the result of simulating the optical path of light that enters the lens portion 25f of the light guide 25 from the light source, is guided, and enters the window glass 10. Light that enters the light receiving surface 25b of the light guide 25 is first reflected on the lower surface (first reflection surface) 25g of the light guide portion 25e, and then is reflected once or twice on the upper surface (second reflection surface) 25h of the light guide portion 25e, and enters the end surface 10c of the window glass 10 facing the step portion 10b, that is, the end surface 12a of the second glass plate or the end surface 13a of the intermediate film. Observing the outline of the cross-sectional structure, the light receiving surface 25b and the light emitting surface 25d are straight lines parallel to each other, the first reflection surface 25g is a curved line convex downward, and the second reflection surface 25h is a curved line convex upward. However, the angle formed by the tangent line of the first reflection surface 25g and the light emitting surface 25d, and the angle formed by the second reflection surface 25h and the light emitting surface 25d are both less than 90 degrees.

[0032] That is, the first reflecting surface 25g is a curved surface in which an angle θ1 formed by a surface tangent to the first reflecting surface 25g in the cross section of the light guide 25 with respect to the light emitting surface 25d decreases as it approaches the light emitting surface 25d, and the second reflecting surface 25h is a curved surface in which an angle θ2 formed by a surface tangent to the second reflecting surface 25h in the cross section of the light guide 25 with respect to the light emitting surface 25d increases as it approaches the light emitting surface 25d.

[0033] In the light guide 25 in which the lens portion 25 f has the above-described shape, further studies have been conducted on a shape that improves the light emission efficiency of the window glass 10 . Fig.11 : is a diagram showing the cross-sectional structure of the end of the light-emitting unit 20, showing a cross section perpendicular to the light-emitting surface 25d of the light guide 25 and the upper surface 25a of the storage portion 25c. In the cross section, the distance T1 between the lowest portion of the upper surface of the light-guiding portion 25e of the light guide 25 and the first reflecting surface 25g is preferably smaller than the distance T2 between the highest portion of the lower surface of the light-guiding portion 25e and the highest portion of the second reflecting surface 25h, and the radius of curvature R1 of the first reflecting surface 25g is preferably smaller than the radius of curvature R2 of the second reflecting surface 25h. For example, T1 / T2 may be 0.5 to 1, preferably 0.7 to 0.9, and R1 / R2 may be 0.1 to 1.0, preferably 0.3 to 0.8. Fig.11 In the structure shown, preferably, the width of the light guiding portion 25e, i.e., the shortest distance w from the light receiving surface 25b to the light emitting surface 25d is 3.0mm to 15.0mm, the curvature radius R1 is 1.0mm to 8.0mm, the curvature radius R2 is 2.0mm to 10.0mm, T1 is 1.0mm to 5.0mm, and T2 is approximately 1.0mm to 5.0mm.

[0034] According to the above structure, it is possible to Fig. 9In a cross section perpendicular to the surface of the window glass 10, light whose incident angle θ entering the window glass is 20° or less accounts for 40% or more of the total luminous flux of the light source (LED).

[0035] In the vehicle lighting structure 1 of the above structure, LED can usually be used as the light source. The luminous color of the LED is not particularly limited, and red, blue, green single-color LEDs, white LEDs or full-color LEDs can be used. As a support (LED substrate), a support obtained by processing wiring for LED light emission on a common glass epoxy substrate (FR4) can be used. The shell part can be formed of engineering plastics such as polycarbonate and ABS resin. As a light guide, an acrylic resin such as PMMA can be used.

[0036] The first glass plate 11 and the second glass plate 12 constituting the window glass 10 may be inorganic glass or organic glass. As inorganic glass, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, quartz glass, etc. may be used. As organic glass, polycarbonate glass, acrylic glass, etc. may be used. As the intermediate film 13, thermoplastic polyvinyl butyral (PVB), ethylene vinyl acetate copolymer (EVA), etc. may be used.

[0037] The window glass 10 may be a flat surface, but may also be a curved surface that is slightly convex relative to the vehicle interior side. The second glass plate 12 and the first glass plate 11 may each have a thickness of about 1.0 mm to 6.0 mm, and the intermediate film 13 may have a thickness of about 0.1 mm to 1.2 mm. An optical pattern may be provided at the interface between the intermediate film 13 and the second glass plate 12. For example, the intermediate film 13 may have a double-layer structure, and an optical pattern may be provided on one layer.

[0038] Figure 5 The size and shape of the light emitting unit 20 are not particularly limited. From the perspective of effective use of the window glass, the width W from the edge of the window glass to the inside is preferably about 5 mm to 20 mm. In addition, from the perspective of luminous efficiency, the light guide 25 of the light emitting unit 20 preferably has a curved surface that is convex toward the inside of the window glass when viewed from above. It is also possible to set about 1 to 30 LEDs in each light emitting unit at intervals of about 1.5 mm to 50 mm.

[0039] The lighting structure of the present invention can be used, for example, for the roof glass of an automobile. Furthermore, the vehicle to which the lighting structure is applied is not limited to a four-wheel vehicle, but can also be used for the window glass of a railway vehicle.

[0040] [Example]

[0041] In order to verify the effect of the present invention, Figure 1The lighting structure of the structure shown. As the window glass, a window glass obtained by separating two sheets of 1500mm×1000mm and 2mm thick soda lime glass with an intermediate film was used. The intermediate film is composed of a double-layer structure of polyvinyl butyral with a thickness of 0.8mm and polyvinyl butyral with a thickness of 0.025mm, and a circular scattering pattern with a diameter of 3mm is set at intervals of 20mm on the latter as a scattering layer. At 4 places on the long edge of the window glass, the second glass plate and the intermediate film are cut out in a roughly arc shape, and a light-emitting unit with a width of 158.3mm in the longitudinal direction and a depth of 18.5mm is set, each equipped with 10 full-color LEDs.

[0042] The above-mentioned prototype was used to investigate the light emission state of red, green, and blue luminescent colors at a current of 20 mA, with respect to the peripheral portion 10a of the window glass (refer to Figure 1 ) is shown in the following table. In the case of red light, the light emission attenuates when the distance from the peripheral portion 10a of the window glass exceeds 300mm. In the case of green light and blue light, a light emission state in which the brightness can be measured is observed even at a position about 500mm away from the peripheral portion 10a of the window glass, and it is observed that the structure of the present invention can make substantially the entire surface of the window glass emit light. In addition, it is also confirmed that by setting it as a mixed color of red light and green light and / or blue light, the difference in the attenuation of the light emission brightness caused by the wavelength can be effectively utilized to express the change in color tone. In addition, the light emission brightness is measured using (spectrometer CS-2000 manufactured by Konica Minolta).

[0043]

Table 1

[0044]

Claims

1. A lighting structure for a vehicle, which makes a window glass of the vehicle illuminate, wherein: The vehicle lighting structure comprises a window glass and at least one lighting unit. The window glass is a laminated glass obtained by laminating a first glass plate, an intermediate film, and a second glass plate in this order. The window glass has: a body having a laminated glass construction; and a step portion, when viewed in the thickness direction, the step portion includes only the first glass plate of the first glass plate and the second glass plate, The lighting unit comprises: Multiple light sources; a support body that supports the light source; and a light guide that guides light emitted from the light source so as to make the light incident on an end surface of the second glass plate at a boundary between the main body and the step portion, The light guide has: a housing portion that houses the light source and has a light receiving surface that receives light emitted from the light source; a light emitting surface facing an end surface of the second glass plate at a boundary between the main body and the step portion; as well as a light guide portion disposed between the light receiving surface and the light emitting surface, and guiding the light received by the light receiving surface to a position away from the light source in the thickness direction of the window glass, The light source is sealed between the light guide and the support.

2. The vehicle lighting structure according to claim 1, wherein: The light guide portion of the light guide body has: a first reflecting surface for reflecting light incident from the light receiving surface to the light guide; as well as a second reflecting surface, which reflects the light reflected by the first reflecting surface toward the light-emitting surface; The first reflecting surface is a curved surface whose angle (θ1) formed by a surface tangent to the first reflecting surface in a cross section of the light guide body with respect to the light emitting surface decreases toward the light emitting surface. The second reflecting surface is a curved surface in which an angle (θ2) formed by a surface tangent to the second reflecting surface in a cross section of the light guide with respect to the light emitting surface increases toward the light emitting surface.

3. The vehicle lighting structure according to claim 1 or 2, wherein: The step portion is partially provided at the peripheral portion of the window glass. The lighting unit is at least partially housed in the step portion.

4. The vehicle lighting structure according to claim 1 or 2, wherein: In a cross section perpendicular to the surface of the window glass, light incident on the window glass at an incident angle of 20° or less accounts for 40% or more of a total luminous flux of the light source.

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