JP4501297B2 - Lighting device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an illumination device that emits light from an LED light source via a light guide. The illuminating device of the present invention can be used as a display plate for vehicles including a scuff plate, a display plate for housing such as a nameplate.
[0002]
[Prior art]
A scuff plate illumination device 100 having a configuration shown in FIG. 8 is known as an automotive illumination device. FIG. 8 is a view showing the scuff plate illumination device 100 cut in the longitudinal direction. The scuff plate illumination device 100 includes a flat light guide 110, an LED light source 120 disposed to face the side surface 111 of the light guide, and a cover 130. In such a scuff plate illumination device 100, the light emitted from the LED light source 120 is introduced into the light guide 110 from the side surface 111 of the light guide 110 and is emitted from the design surface 112. If a dial having a light transmitting hole having a desired shape is arranged on the design surface 112, a part of the light emitted from the design surface 112 can be emitted outside through the light transmitting hole of the dial. The desired shape can be displayed with the light of the LED light source.
[0003]
[Problems to be solved by the invention]
As a result of examining the light emission mode of the illumination device having the above-described conventional configuration, it was observed that light with high luminance was emitted from the portion of the design surface located near the LED light source, and as a result, the design surface near the LED light source. There was a significant difference in brightness between the light emitted from the LED and the light emitted from the design surface located away from the LED. That is, the light emission mode was not uniform over the entire design surface. By covering the design surface part near the LED light source that emits high-luminance light with a cover that does not transmit light, it is possible to eliminate the emission of light from the part and to achieve uniform brightness. In such a configuration, the area of the design surface is reduced, and the lighting effect is reduced.
The present invention has been made in view of the above problems, and an object of the present invention is to provide an illumination device that can emit light in a more uniform light emission mode over the entire design surface and has a high illumination effect. .
[0004]
[Means for Solving the Problems]
The inventors of the present invention have repeatedly studied in view of the above problems. As a result, high-luminance light emission on the design surface in the vicinity of the LED light source is the back surface of the light guide near the LED light source in the light emitted from the LED light source. Focusing on the fact that it is caused by the light reflected by the light, it was considered that the brightness of the radiated light can be made uniform over the entire design surface by blocking the light due to the reflection on the back surface of the light guide. The present invention is based on such studies, and the configuration thereof is as follows. That is,
An LED light source;
A light guide that introduces light from the LED light source from the side surface side and emits the light from the upper design surface,
The light guide is formed with a light blocking surface that blocks light directed to the back surface of the light guide located in the vicinity of the LED light source in the light introduced from the side surface side. It is an illuminating device.
[0005]
In the illuminating device thus configured, light directed to the back surface of the light guide located in the vicinity of the LED light source in the light introduced into the light guide is blocked by the light blocking surface. As a result, the light is not reflected and emitted from the upper design surface, and high-luminance light emission near the LED light source is prevented. Thereby, a more uniform light emission mode is obtained over the entire design surface. As described above, according to the configuration of the present invention, the light emitting aspect of the entire design surface can be made uniform without unnecessarily reducing the design surface. That is, the illumination device provided by the present invention has a high illumination effect and can emit light in a more uniform light emission mode over the entire design surface.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, each member of the present invention will be described.
(LED light source)
As the LED light source, various types of LEDs such as a shell type and a chip type can be adopted. Since the LED is small, the entire light emitting device can be miniaturized by using the LED. In addition, the LED light source has advantages such as low driving power and long life. Furthermore, since the calorific value is small, the thermal influence on surrounding members is small.
The emission color of the LED to be employed is not particularly limited. An LED light source may be configured by combining a plurality of LEDs having different emission colors. In the case of using a plurality of LEDs, it is possible to control the light emission state of each LED and emit light of various light emission modes. For example, if LEDs of red, green, and blue are used and the light emission state and light emission amount of each LED are controlled, a desired color can be emitted. The number of LEDs to be used is determined by comprehensively considering the size of the light guide described later (particularly the size of the upper design surface of the light guide), the required luminance, and the like.
[0007]
The LED light source is disposed so as to face a side surface of a light guide described later, and introduces light into the light guide from the side surface. It is preferable to arrange the LED light source so that the optical axis of the LED light source is substantially parallel to the upper design surface of the light guide. Thereby, the brightness | luminance of the light radiated | emitted in the part close | similar to the LED light source of an upper surface design surface, and the brightness | luminance of the light radiated | emitted in a distant part can be aimed at. Therefore, when a top design surface having a large area is adopted, light can be emitted with more uniform luminance over the entire top design surface.
[0008]
(Light guide)
The light guide body introduces the light from the LED light source from the side surface and emits the light introduced from the upper design surface. Here, the upper design surface refers to a surface from which light is emitted in the light guide. The shape of the upper design surface is designed according to the radiation mode of light. For example, the upper design surface is a flat surface so that planar light emission can be obtained. Part or all of them can be curved.
The material of the light guide is not particularly limited as long as it is light transmissive. Preferably, the light guide is made of a transparent material. Moreover, it is preferable to comprise a light guide with the material which is easy to process and excellent in durability. As a material of the light guide, for example, polycarbonate resin, acrylic resin, epoxy resin, glass, or the like can be used.
[0009]
The light guide is formed with a light blocking surface that blocks light directed toward the back of the light guide located near the LED light source in the light of the LED light source introduced from the side surface side. The light blocking surface here will be described with reference to FIG. In FIG. 1, reference numeral 60 is an LED light source, and reference numerals 50, 51 and 52 are flat light guides. (A) is a figure which shows the case where the light-shielding surface is not provided in the light guide, The light (61) which went to the LED vicinity part of the light guide back surface (50c) from the LED light source (60), The light is reflected by the back surface (50c) and emitted from the vicinity of the LED (portion indicated by oblique lines) on the upper design surface (50a). (B) and (C) show a case where a light blocking surface is provided. That is, in (B), the light guide (51) is provided with a light blocking surface (51b) that blocks light (61). Similarly, in (C), the light guide (52) has a light blocking surface ( 52b). In the light guide of (B), the back surface (51c) of the light guide is formed in a step shape in the vicinity of the LED light source (60) to form a light blocking surface (51b). Further, in the light guide (52) of (C), a cut groove is provided in the back surface (52c) of the light guide near the LED light source (60), thereby forming a light blocking surface (52b).
[0010]
The light blocking surface does not have to be a surface perpendicular to the back surface of the light guide as shown in FIGS. 1B and 1C. For example, the light from the LED light source is against the light blocking surface. It can be a surface formed at an angle that allows incidence to be perpendicular. Further, the shape of the light blocking surface is not limited to a flat surface as a whole. The light blocking surface is preferably sized so as to block light traveling toward the rear surface of the light guide near the LED light source and to block light emitted from the LED light source in the optical axis direction as much as possible. This is because if an unnecessarily large light blocking surface is provided to block light emitted in the direction of the optical axis, the amount of light emitted from the upper surface is reduced.
The position where the light blocking surface is formed is not limited to the back side of the light guide, and for example, as shown in FIG. 2 (a) or (b), the LED light source (60) of the light guide (53, 54). It is also possible to form light blocking surfaces (53b, 54b) on the side surfaces (53d, 54d) facing each other. Furthermore, the light blocking surface can be formed of a material that blocks light. For example, an aluminum plate or the like is inserted into the light blocking surface.
[0011]
By adopting the light blocking surface as described above, generation of reflected light on the back surface of the light guide near the LED light source as shown in FIG. 1A is prevented. It is preferable to apply a colored tape on the surface, print, apply, paint, etc., a colored ink, a paint or the like. In particular, when a black paint or the like is used, a light blocking surface having a very high blocking effect is obtained.
Alternatively, the surface of the light blocking surface may be subjected to a light diffusion treatment to diffuse the light on the surface.
[0012]
It is preferable to cover the light source side edge of the upper design surface with a light blocking member. That is, it is preferable that light is not emitted from the surface of the edge. A part of the light emitted from the LED light source is directly emitted to the edge, and as a result, light with higher brightness is emitted from the surface of the edge compared to other parts. This is because the high-luminance light emission is blocked and the luminance of the entire upper design surface is made uniform. In addition, the LED light source side edge part of an upper surface design surface means the edge part adjacent to the light guide body side surface which an LED light source opposes in an upper surface design surface.
[0013]
As the light guide, an LED light source and a light source having a groove for accommodating the wiring of the LED light source can be adopted. In this way, since the LED light source can be stored in the light guide, it is not necessary to provide a separate housing for storing the LED light source, and the number of components can be reduced. In addition, the LED light source and the light guide are integrally configured, so that the sealing performance can be improved, and an illumination device having a high dustproof and waterproof effect can be configured. For example, a groove can be provided on the upper design surface side so as to substantially follow the peripheral wall of the light guide.
[0014]
It is preferable to provide a light reflecting layer on the back surface of the light guide. By providing the light reflecting layer, the light introduced into the light guide can be condensed on the light reflecting layer and reflected in the upper design surface direction. The light reflecting layer can be formed by printing, vapor deposition, sputtering or the like using a light reflecting ink (for example, white ink). It can also be formed by sticking a white tape. It is preferable to use a light-reflective ink or a white tape having a high light reflectance. Furthermore, the light reflecting layer can also be formed by roughening the back surface of the light guide by a process such as etching, sandblasting, or electrical discharge machining.
[0015]
A half mirror layer can also be provided on the surface of the upper design surface. By providing the half mirror layer, the color of light observed on the upper design surface can be made different between a bright state and a dark state on the outside. The half mirror layer can be provided, for example, by sequentially laminating a metal layer, a protective layer, and an ink layer on the surface of the upper design surface. If an example of the formation method of such a half mirror layer is shown, first, Al will be vapor-deposited on the surface of an upper surface design surface, and the metal layer consisting of an Al thin film will be formed. The thickness of the metal layer is such that a half mirror effect can be obtained. For example, the metal layer can have a thickness such that the light transmittance is about 15-20%. Subsequently, a transparent resin such as an epoxy resin is formed on the metal layer by printing, coating or the like to form a protective layer. Finally, an ink layer is formed by printing, applying, or the like with a color ink such as yellow. Of course, the method of forming the half mirror layer is not limited to this, and the material of the metal layer and the protective layer, and the material and color of the ink layer can be arbitrarily selected. In addition, a half mirror layer can also be provided in the back surface of a light guide or the back surface of the light transmissive sheet mentioned later.
[0016]
Moreover, the layer containing a fluorescent substance can also be formed in the surface of an upper surface design surface, or a light guide back surface. If it does in this way, a part of light of a LED light source can be wavelength-converted with fluorescent substance, and the color of the light radiated | emitted from an upper surface design surface can be converted. When the half mirror layer is formed as described above, a phosphor can be contained in the ink layer constituting the half mirror layer.
[0017]
A dial having a light transmitting hole of a desired shape is arranged in the light emission direction of the upper surface design surface of the light guide, and the desired shape can be displayed by light emitted from the upper surface design surface. The dial can be manufactured by providing a light transmission hole in a part of a material that does not transmit light. For example, a thin plate made of various metals, alloys or the like is prepared, and a part of the thin plate is removed by etching or pressing to provide a light transmitting hole having a desired shape. As the material that does not transmit light, opaque resin, plastic, or the like can be used. As described above, when a dial is made using a material that does not transmit light, the light transmitting hole can be filled with a transparent resin such as polyvinyl chloride or epoxy resin. On the other hand, the dial can be formed of a material that transmits light. For example, a thin plate made of acrylic resin or the like is prepared, and light-impermeable ink is printed so that a desired shape portion remains in an island shape on the surface. In this way, a dial plate that can transmit light only from a desired shape portion is formed. A layer made of a metal, an alloy, or the like may be provided on the surface of the dial, and the design may be changed.
By forming a light-impermeable layer by leaving a desired shape portion on the upper surface of the light guide without using a dial, light can be emitted only from the desired shape portion and displayed. . Such a light-impermeable layer can be formed by, for example, printing, coating, painting, or the like of black ink.
[0018]
A light-transmitting sheet that covers the upper surface of the light guide and whose peripheral edge is bonded to the light guide can be used. When the dial is used as described above, the light transmissive sheet is used on the dial so as to cover the light emission side.
As a material for forming the light transmissive sheet, polycarbonate resin, acrylic resin, epoxy resin, or the like can be used. It is preferable to perform a hard coat treatment or the like on the upper surface of the light transmissive sheet for the purpose of preventing scratches or preventing dirt. By using the light transmissive sheet, it is possible to prevent scratches, stains, and the like on the upper design surface of the light guide.
Adhesion between the light transmitting sheet and the light guide can be performed using an adhesive, a seal, or the like. Alternatively, the light transmissive sheet may be formed of the same material as the light guide (for example, polycarbonate resin), and the light transmissive sheet and the light guide may be welded together to bond them together. As a welding method, a known method can be adopted.
[0019]
【Example】
Hereinafter, the present invention will be described in more detail by taking a scuff plate illumination device 1 according to an embodiment of the present invention as an example. The scuff plate illumination device 1 is used by being attached to a side step portion of an automobile, and displays a desired shape with light from an LED light source.
FIG. 3 is a perspective view showing a state before the scuff plate illumination device 1 is assembled. FIG. 4 is a plan view of the assembled scuff plate illumination device 1 as seen from the light emission observation surface side. 5 and 6 are a cross-sectional view taken along line AA and a cross-sectional view taken along line BB in FIG. 4, respectively. Hereinafter, the configuration of the scuff plate illumination device 1 will be described with reference to the drawings.
[0020]
As shown in FIG. 3, the scuff plate illuminating device 1 is generally configured by a light guide 10, a light source unit 20, a dial 30, and a light transmissive sheet 40.
The light guide 10 is polycarbonate resin. A groove portion 15 is provided on one surface of the light guide 10 so as to be substantially along the peripheral wall, whereby a frame-shaped peripheral edge portion 17 and an island-shaped light guide portion 11 are formed. The surface of the central portion of the light guide 11 forms an upper design surface 12. In addition, light introducing portions 14 are formed at both ends of the light guide portion 11. Note that the upper design surface 12 is formed at a position lower than the peripheral edge portion 17 (a lower position in the figure). A metal layer 13 made of a gold foil is formed on the surface of the upper design surface 12. The metal layer 13 was formed by hot stamping.
[0021]
A recess 18 is formed at both ends of the groove portion 15 toward the outside, and substrates 24 and 25 of the light source unit 20 to be described later are housed therein.
[0022]
The surface opposite to the side where the groove portion of the light guide 10 is formed (the surface opposite to the light emission observation surface; hereinafter referred to as “the back surface of the light guide 10”) is lowered one step toward the upper surface design surface at both ends. The light blocking surface 19 is formed in a shape (see FIGS. 3 and 5). In this example, the light guide 10 having the above shape was produced by injection molding. Black tape is stuck on the surface of the light blocking surface.
A light reflecting layer 16 is formed on a part of the back surface of the light guide 10 (see FIGS. 4, 5, and 6). The light reflection layer 16 is provided for the purpose of collecting the light from the LEDs 21 and 22 and reflecting the light in the light emission direction. In this embodiment, the light reflecting layer 16 is formed by white printing. The light reflection layer 16 is formed so as to include at least a region in which the character portions 31 to 35 of the dial plate 30 are normally projected on the back surface of the light guide 10 in a state where the dial plate 30 is disposed. In this embodiment, the light reflecting layer 16 having a shape substantially similar to that of the dial is formed in an area slightly smaller than the area where the dial 30 is normally projected on the back surface of the light guide 10. By reducing the area where the light reflection layer 16 is formed in this way, the area where the light from the LEDs 21 and 22 is collected is reduced, and as a result, the light can be uniformly collected on the entire light reflection layer 16. The light can be reflected with a uniform amount of light over the entire light reflection layer 16.
[0023]
The light reflecting layer 16 can be formed even smaller. For example, in a state where the dial 30 is disposed, the light reflecting layer 16 is projected on the back surface of the light guide 10 by the character portions 31 to 35 of the dial 30. It can also be formed so as to cover an area slightly wider than the area to be formed. That is, the light reflection layer 16 is provided so as to cover at least the region of the back surface of the light guide 10 that can be seen through the character portions 31 to 35 of the dial plate 30 when the scuff plate illumination device 1 is viewed in front of the emission observation surface side. You can also. Further, the light reflecting layer 16 having a shape substantially similar to that of the character portion is provided so that the character portions 31 to 35 of the dial 30 cover a region slightly wider than the region projected on the back surface of the light guide 10. You can also. Thus, even when the scuff plate illumination device 1 is viewed from an oblique direction, the light reflecting layer 16 is also provided on the back surface portion of the light guide 10 that can be seen through the character portions 31 to 35 of the dial plate 30. It can prevent that the light emission mode from the character parts 31-35 changes with angles. Further, instead of providing the light reflection layer in a shape similar to the character portions 31 to 35, a light reflection layer corresponding to the shape of the character portions 31 to 35 can be provided. For example, taking the case of the present embodiment as an example, a light reflecting layer such as a quadrangle, a triangle, or a circle can be provided so as to cover a region in which each character part is normally projected on the back surface of the light guide 10.
[0024]
The light source unit 20 includes LEDs 21 and 22, substrates 24 and 25 on which the LEDs are mounted, and wiring 26 that supplies power to the LEDs.
As the LEDs 21 and 22, bullet-type LEDs having an amber emission color were used. The light source unit 20 is connected to a power source and a control circuit (not shown), and the lighting states of the LEDs 21 and 22 are controlled in conjunction with opening and closing of the door.
[0025]
The dial plate 30 is an aluminum member having character portions 31 to 35, shields part of light emitted from the upper design surface 12 of the light guide 10, and emits light only from the character portions 31 to 35. It functions as a mask member. In the present embodiment, the character portions 31 to 35 are formed by etching an aluminum thin plate.
[0026]
After the light source unit 20 is assembled to the light guide 10, the dial 30 is placed so as to cover the upper design surface 12 of the light guide 10. At this time, it is preferable to fix the dial 30 to the upper design surface 12 using an adhesive, a tape, or the like. In this embodiment, the dial 30 is fixed using a transparent double-sided tape.
[0027]
The light transmissive sheet 40 is a polycarbonate sheet. After the light source unit 20 and the dial 30 are assembled to the light guide 10, the light transmissive sheet 40 is covered so as to cover the light emission observation surface side of the dial 30. The upper surface of the light transmissive sheet 40 was subjected to a hard coat process.
[0028]
The peripheral edge 41 of the light transmissive sheet 40 is bonded to the light guide 10. In the present embodiment, the light transmission sheet 40 and the light guide 10 have substantially the same planar view shape, and the peripheral edge 41 of the light transparent sheet 40 is bonded to the peripheral edge 17 of the light guide 10. Thereby, it can prevent that dust, water, etc. permeate into the light guide 10 from the light emission observation surface side. As a result, the light emitting surface 12 of the light guide 10 can be prevented from being damaged and soiled as much as possible. Further, the influence of dust and water on the LED unit 20 can be prevented as much as possible. Adhesion between the light-transmitting sheet 40 and the light guide 10 was performed by welding them. First, innumerable mountain-shaped protrusions are formed on the upper surface of the peripheral edge portion 17 of the polycarbonate light guide 10, and after placing the light-transmitting sheet 40 thereon, high-frequency vibrations in the horizontal direction or the vertical direction are applied. It was. Thus, the protrusion formed on the peripheral edge portion 17 of the light guide 10 was melted, and the light transmissive sheet 40 and the light guide 10 were welded.
The wiring opening 27 of the light guide 10 is filled with a sealer after wiring for waterproofing and dustproofing.
[0029]
The scuff plate illumination device 1 configured as described above can be used with a cover 70 made of metal or the like (for example, made of SUS) as shown in FIG. By using the cover 70, the scuff plate illumination device 1 can be protected from an external impact. Further, it is possible to prevent the light emitting surface (light transmissive sheet surface) from being damaged. Furthermore, the cover 70 covers and shields the vicinity of the LEDs 21 and 22, thereby preventing emission of high-intensity light through the part, that is, reducing light emission unevenness.
[0030]
Next, a light emission mode in the scuff plate illumination device 1 will be described with reference to FIG. For convenience of explanation, a mode in which light emitted from the LED 21 is emitted from the character portion 31 of the dial 30 will be described as an example. First, the light emitted from the LED 21 in the optical axis direction is introduced into the light guide 10 from the light introduction unit 14. Such light travels through the light guide 10 and is collected by the light reflection layer 16 and then reflected in the light emission direction (upward in FIG. 5). The reflected light is emitted from the upper design surface 12 of the light guide 10, is color-converted by the metal layer 13, and then emitted through the character portion 31 of the dial 30. On the other hand, the light emitted from the LED 21 to the back side of the light guide 10 is blocked by the light blocking surface 19. Therefore, such light is directed to the upper design surface 12 and is not emitted through the character part 31, and as a result, the character part 31 is displayed with higher brightness than the other character parts 32 or the like. Absent. Thereby, it becomes an illuminating device with little light emission nonuniformity over the whole character part.
[0031]
The scuff plate illumination device 1 has been described as an example to which the present invention is applied. However, the illumination device of the present invention can be applied to other vehicle interior illumination devices (for example, plate illumination devices attached to door portions, pillar portions). The present invention can be applied to a line illuminating device or the like attached to the head. Further, the present invention is not limited to an automobile lighting device, and can also be applied to a lighting device such as a display plate in various vehicles, a display plate in a dwelling interior, or a display plate in an exterior such as a nameplate.
[0032]
The present invention is not limited to the description of the embodiment of the invention. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an aspect of a light blocking surface formed on a light guide.
FIG. 2 is a diagram for explaining an aspect of a light blocking surface formed on the light guide body.
FIG. 3 is a perspective view showing a state before assembly of the scuff plate illumination device 1 according to one embodiment of the present invention.
FIG. 4 is a plan view of the scuff plate illumination device 1 in the same assembled state as seen from the emission observation surface side.
5 is a cross-sectional view taken along line AA in FIG. 4. FIG.
FIG. 6 is a cross-sectional view taken along line BB in FIG.
FIG. 7 is a perspective view showing the scuff plate lighting device 1 to which a cover 70 is attached.
FIG. 8 is a diagram showing a scuff plate illumination device 100 having a conventional configuration.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Scuff plate illuminating device 10 Light guide 12 Light emission surface 13 Metal layer 14 Groove part 16 Light reflection layer 19 Light shielding layer 20 Light source unit 21 22 LED
30 Dial 31 32 33 34 35 Character 40 Light-transmissive sheet 70 Cover

Claims (11)

An LED light source;
A light guide that introduces the light from the LED light source from the side surface and emits it from the upper design surface;
With
The light guide is formed with a light blocking surface that blocks light directed toward the back surface of the light guide located in the vicinity of the LED light source in the light introduced from the side surface side ,
The optical axis of the LED light source and the upper design surface are substantially parallel,
The LED light source side edge of the upper design surface is covered with a light blocking member,
The back surface of the light guide is formed in a staircase shape in the vicinity of the LED light source, and the light blocking surface is a wall surface formed from the surface of the back surface of the light guide toward the upper design surface. A lighting device. The lightguide lighting device of claim 1, wherein the LED comprises a light source and a groove for accommodating the wire of the LED light source, characterized in that. A dial having a light transmitting hole of a desired shape, arranged in the light emitting direction of the upper design surface,
The character covers the light emitting surface side of the plate, further comprising a light transmitting sheet to the peripheral portion is bonded to the light guide, that lighting device according to claim 1 or 2, characterized in. The lighting device according to claim 3 , wherein the light transmissive sheet covers the light emitting surface side of the dial and the groove portion of the light guide. The lighting device according to claim 2 , wherein the groove is formed on the upper design surface side of the light guide. The said light guide and the said light transmissive sheet | seat consist of the same material, and the said adhesion | attachment is performed by welding of the said light guide and the said light transmissive sheet | seats, The any one of Claims 3-5 characterized by the above-mentioned. A lighting device according to claim 1. The lighting device according to any one of claims 1 to 6, wherein the metal layer on the top surface design surface of the light guide body is formed, it is characterized. The lighting device according to any one of claims 1 to 7, wherein said light guide back surface on the light reflecting layer is formed, it is characterized. The lighting device, the lighting device according to any one of claims 1 to 8, a scuff plate installed in side step portion of the automobile, it is characterized. The lighting device according to claim 1, wherein a black colored member is disposed on the light blocking surface. The lighting device according to claim 1, wherein the light blocking surface is formed vertically toward the upper design surface.

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