JP4161042B2 - Light source device for display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light source device for display that can obtain uniform surface light emission using a light emitting diode as a light source.
[0002]
[Prior art]
Conventionally, this type of light source device for display has been used for various purposes such as backlights for advertising billboards and light-emitting display boards for notifying various information. Generally, these light sources include fluorescent lamps and neon sign tubes. It was used.
[0003]
Light-emitting diodes are also known as one of the light sources, which are mainly used for displays and displays, and are often used as pilot lamps that are installed in various devices to indicate power on / off and operating status. It had been.
[0004]
[Problems to be solved by the invention]
However, in the conventional technique as described above, when the light source is a fluorescent lamp or a neon sign tube, since the durability time is shorter than that of the light emitting diode, the replacement work is troublesome and the cost is increased.
[0005]
In addition, since fluorescent lamps and the like are discharge-type light emission, there is a problem that the turn-on / light-out time is slow, and the photoelectric conversion efficiency is relatively low, resulting in high power consumption. Further, it is difficult to make the length and thickness thin, and the degree of freedom of shape is remarkably limited. Furthermore, there is a practical problem that it is weak against impact and easily damaged.
[0006]
On the other hand, display light source devices using light-emitting diodes have a longer life than fluorescent lamps, etc., have extremely high visibility and brightness, are not discharge-like light emission, and turn on and off quickly, and consume high photoelectric conversion efficiency. There are advantages such as low power and excellent impact resistance, but there are the following problems.
[0007]
In other words, the light-emitting diode can obtain a high-luminance luminous flux due to its characteristics, but its directivity angle is very narrow, so even if it is arranged in a matrix at a high density, it will hit the luminous flux when used as a backlight for advertising billboards Light and dark (brightness unevenness) of light occurs between the portion and the portion that does not hit, making it difficult to obtain uniform surface light emission.
[0008]
Here, if the thickness of the light transmitting plate covering the light emitting diodes is increased, even if each light emitting diode functions as a point light source, it is possible to prevent uneven brightness on the light emitting surface of the light transmitting plate, May decrease, resulting in a new problem of overall lowering of luminance.
[0009]
The present invention has been made by paying attention to the above-described problems of the prior art, and has excellent characteristics of a light emitting diode, does not cause uneven light and darkness of light, and is high even with low power consumption. An object of the present invention is to provide a display light source device capable of obtaining uniform surface light emission with brightness.
[0010]
[Means for Solving the Problems]
The gist of the present invention for achieving the object described above resides in the inventions of the following items.
[1] In a display light source device (10) capable of obtaining uniform surface light emission using a light emitting diode (30) as a light source,
A transparent light guide plate (20) previously formed into a plate shape by a transparent and translucent resin, a form (11) having an opening on the upper surface side in a shape matching the transparent light guide plate (20), and the transparent guide A light emitting diode (30) adhered in a predetermined arrangement on the light plate (20) by a transparent and translucent resin adhesive (40), and the light emitting diode (30) and the resin adhesive (40) A light dispersion resin (50) laminated on
The mold (11) is formed by combining the transparent light guide plate (20) fitted inside, the light emitting diode (30) and the resinous adhesive (40), and the light dispersion resin (50). is formed to a depth corresponding to the thickness, the entire inner surface light reflection efficiency high light reflectivity coating (12) is applied, the light reflective coating (12) is in a state of half-dried, on the coated surface By spraying a large number of beads (13), a large number of beads (13) that promote optical diffuse reflection using the light-reflecting paint (12) as an adhesive medium are attached,
The light emitting diode (30) is formed of a chip LED, the irradiation side of the light emitting element (31) is opposed to the bottom surface of the mold (11), and a plurality of light emitting diodes (30) on the transparent light guide plate (20) have a predetermined interval on a plane. Arranged in a line,
The resinous adhesive (40) is laminated on the transparent light guide plate (20) in a state where the light emitting diode (30) can be entirely covered in the thickness direction,
The light source device for display (10), wherein the light-dispersing resin (50) is laminated on the resinous adhesive (40) so as to cover the opened upper surface side of the mold (11).
[0011]
[2] The light source device for display (10) according to [1], wherein the light-reflecting paint (12) is a white paint, and the beads (13) are colorless and transparent glass spheres.
[0013]
Next, the operation of the display light source device (10) according to the present invention will be described.
High-intensity light with a relatively narrow directivity angle irradiated from the light emitting diode (30) does not go directly to the side of the light dispersion resin (50) laminated on the upper surface side of the mold (11), but this light dispersion resin. Irradiation is directed toward the bottom surface of the mold (11) located in the opposite direction to the exit surface of (50).
[0014]
A large number of beads (13) that promote optical diffuse reflection are attached to the entire inner surface including the bottom surface of the mold (11) using the light-reflective coating (12) as an adhesive medium. The luminance light is refracted and reflected in various directions and is dispersed over a wide area in the transparent light guide plate (20) fitted in the mold (11).
[0015]
Thus, the light irregularly reflected in various directions in the mold (11) is averaged without reducing the luminance while passing through the transparent light guide plate (20) fitted in the mold (11). After that, the light toward the upper surface side where the mold (11) is opened is irradiated to the outside through the light dispersion resin (50). In the light-dispersing resin (50), the light is further diffusely reflected in various directions, so that the transit time of the light becomes longer and the variation in luminance is further eliminated.
[0016]
As described above, uniform surface emission with high luminance can be obtained from the exit surface of the light dispersion resin (50) covering the opening of the mold (11). Such surface emission has various angle components of light, and can be easily visually recognized from an angular direction that is an acute angle with respect to the emission surface of the light dispersion resin (50) or from a distant place. It becomes.
[0017]
In order to manufacture the display light source device (10), an existing acrylic plate or polycarbonate plate can be cut into a predetermined size and shape and used as it is as the transparent light guide plate (20). Therefore, as compared with the case where the main part is manufactured by filling with a dissolved resin, it is possible to easily manufacture in an extremely short time without taking time for dissolution and filling of resin and drying and curing.
[0018]
The light-emitting diode (30) is made of a chip LED, and the resin adhesive (40) for bonding the light-emitting diode (30) on the transparent light guide plate (20) has an intrinsic thickness of the chip LED. It is sufficient to use it as a thin layer that can be covered in all directions. Accordingly, the display light source device (10) as a whole can be further reduced in thickness. In addition, since the mold (11) into which the transparent light guide plate (20) is fitted serves as a reinforcing material for the entire structure, it is possible to maintain a considerable strength even if the thickness is reduced.
[0019]
In addition, if the light-reflective coating (12) is a white coating and the beads (13) are colorless and transparent glass spheres, each can be inexpensive and can be reduced in cost. Light reflection efficiency and optical irregular reflection efficiency can be obtained.
[0020]
Furthermore, if the light dispersion resin (50) is a mixture of a light dispersion material and a colorant of the same color as the light emitting diode (30) in a transparent and translucent resin, More clear and vivid light can be obtained.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment that represents the present invention will be described based on the drawings.
1 to 4 show an embodiment of the present invention.
The display light source device 10 according to the present embodiment is a device that can obtain uniform surface light emission using the light emitting diode 20 as a light source.
[0022]
As shown in FIG. 1, the display light source device 10 includes a transparent light guide plate 20 in which a transparent and translucent resin is previously formed into a plate shape, and an upper surface side having an opening that matches the transparent light guide plate 20. A mold 11, a light emitting diode 30 adhered to the transparent light guide plate 20 by a transparent and translucent resin adhesive 40 in a predetermined arrangement, and the light emitting diode 30 and the resin adhesive 40 And a light dispersion resin 50 laminated on the substrate.
[0023]
The mold 11 is formed of a sheet metal or the like in a thin box shape whose upper surface side opens in a rectangular shape and spreads in the plane direction, and includes a transparent light guide plate 20 fitted inside, a light emitting diode 30 and a resinous adhesive 40. The depth corresponding to the total thickness of the light dispersion resin 50 is set.
[0024]
The entire inner surface of the mold 11 is coated with a light reflective paint 12 having a high light reflection efficiency. Furthermore, the entire inner surface of the mold 11 is coated with a number of beads using the light reflective paint 12 as an adhesive medium. 13 is attached. Here, various paints are conceivable as the light-reflecting paint 12, and for example, a white paint having a high light reflection efficiency may be used.
[0025]
The beads 13 may have any form as long as they promote optical irregular reflection. For example, a colorless and transparent glass sphere having a size of about several tens of microns may be used. The beads 13 can be easily attached by spraying the light-reflecting paint 12 in a state of being dried.
[0026]
The transparent light guide plate 20 is formed by previously forming a transparent and translucent resin into a plate shape, and is used by being cut into a shape matching the mold 11 so as to be fitted into the mold 11. Specifically, the transparent light guide plate 20 may be a commercially available synthetic resin plate in which a colorless and transparent resin such as an epoxy resin, a polycarbonate resin, or a methacrylic resin is processed in advance as a plate material.
[0027]
The light-emitting diode 30 has a longer life than a fluorescent lamp, a neon sign tube, etc., has extremely high visibility and brightness, is not thermally or discharge-like light emission, has a fast turn-on / off time, and has high photoelectric conversion efficiency. And has characteristics such as excellent impact resistance.
[0028]
Specifically, the light emitting diode 30 is a chip LED including a light emitting element 31 mounted on a lead wire 32. The chip LED is different from a so-called LED lamp, and is a type in which the chip-like lead wire 32 is not covered with a mold resin formed in a substantially bullet-shaped lens shape. In addition, since the detailed structure of chip | tip LED is common, description is abbreviate | omitted.
[0029]
As shown in FIG. 1 and FIG. 3, the light emitting diode 30 has an irradiation side of the light emitting element 31 facing the bottom surface of the mold 11, and a plurality of light emitting diodes 31 on the transparent light guide plate 20 at a predetermined interval on a plane. It arrange | positions in the state connected to the lead wire 32 so that it may rank with a space | interval. Note that the lead terminals in the light emitting element 31 are soldered in advance to appropriate positions of the grid-like lead wires 32 shown in FIG.
[0030]
Each light emitting diode 30 is entirely covered with the resinous adhesive 40 in the thickness direction, and is bonded and fixed on the transparent light guide plate 20 while being buried in the resinous adhesive 40. Here, the resinous adhesive 40 is transparent and translucent like the transparent light guide plate 20, and is obtained by dissolving a resin of the same material as the transparent light guide plate 20 in a sol form with a predetermined solvent. May be used as they are.
[0031]
The light dispersion resin 50 is laminated on the upper surface side of the resinous adhesive 40 so as to cover the opened upper surface side of the mold 11. Specifically, the light dispersion resin 50 is formed by mixing a light dispersion material and a colorant having the same color as the light emitting diode 30 in a transparent and translucent resin.
[0032]
Here, as the transparent and translucent resin, an epoxy resin or the like may be used similarly to the transparent light guide plate 20 described above. Moreover, titanium oxide, magnesium oxide, etc. are suitable for the light dispersion material. If a fluorescent dye having a color similar to that of the light emitting diode 30 is used as the colorant, a brighter luminescent color can be obtained.
[0033]
Next, the operation of the display light source device 10 according to the present embodiment will be described.
In order to manufacture the display light source device 10, an existing acrylic plate or polycarbonate plate can be cut into a predetermined size and shape and used as the transparent light guide plate 20 as it is. Therefore, as compared with the case where the main part is manufactured by filling with a dissolved resin, it is possible to easily manufacture in an extremely short time without taking time for dissolution and filling of resin and drying and curing.
[0034]
The mold 11 can be easily formed from sheet metal in accordance with the size and shape of the transparent light guide plate 20, and a light-reflective coating 12 is applied to the entire inner surface of the mold 11. A large number of beads 13 are sprayed onto the coated surface in a state where the light-reflective coating 12 is dried. Thereby, a large number of beads 13 that promote optical irregular reflection are attached to the entire inner surface of the mold 11 using the light-reflective coating 12 as an adhesive medium.
[0035]
When the light-reflective coating 12 is completely dried and hardened in a state where a large number of beads 13 are also adhered, the transparent light guide plate 20 is fitted into the mold 11. Here, the mold 11 having a large number of beads 13 adhered thereto. As in the transparent light guide plate 20, a transparent and light-transmitting adhesive or resin may be filled between the inner surface of the transparent light guide plate 20 and the lower end surface and the peripheral end surface of the transparent light guide plate 20 to close a small gap.
[0036]
Subsequently, after a plurality of light emitting diodes 30 connected in advance to the lead wires 32 are arranged at equal intervals on the upper surface of the transparent light guide plate 20, the light emitting diodes 30 on the transparent light guide plate 20 are respectively arranged in the thickness direction. Then, the resinous adhesive 40 is laminated so as to be covered. At this time, care is taken so that bubbles do not enter inside the resinous adhesive 40, particularly around the light emitting diode 30. When the resinous adhesive 40 is hardened, the light dispersion resin 50 may be laminated thereon.
[0037]
The light emitting diode 30 is composed of a chip LED, and the resin adhesive 40 for adhering the light emitting diode 30 to the transparent light guide plate 20 is a thin layer that can cover the chip LED that is originally thin in the thickness direction. If it is used as, it is enough. For this reason, the display light source device 10 as a whole can be further reduced in thickness. In addition, since the mold 11 into which the transparent light guide plate 20 is fitted serves as a reinforcing material for the entire structure, a considerable strength can be maintained even if the thickness is reduced.
[0038]
The display light source device 10 manufactured in this way can be used for various purposes, and in particular, it may be applied to a backlight of an advertising billboard. Specifically, a plurality of display light source devices 10 are prepared as units and installed so as to be closely arranged in a planar shape or a curved shape. If an advertising sheet (not shown) such as a translucent photographic film is attached to the flat or curved surface where the display light source devices 10 are arranged, the advertising sheet can be made to emit light clearly.
[0039]
As shown in FIG. 4, the high-intensity light with a relatively narrow directivity angle α irradiated from the light emitting diode 30 of the display light source device 10 is directly directed to the light dispersion resin 50 side laminated on the upper surface side of the mold 11. Irradiation is directed toward the bottom surface of the mold 11 located in the direction opposite to the light exit surface 51 of the light dispersion resin 50 without going toward it.
[0040]
Since the entire inner surface including the bottom surface of the mold 11 has a large number of beads 13 for promoting optical irregular reflection using the light-reflective coating 12 as an adhesive medium, the high-intensity light is directed in various directions by the beads 13. The light is refracted and dispersed over a wide area in the transparent light guide plate 20 fitted in the mold 11.
[0041]
Since light mainly passes through the transparent light guide plate 20 as described above, the entire area of the transparent light guide plate 20 becomes a diffused light source region without lowering the luminance as compared with the case of passing through the air. Moreover, since the entire light emitting diode 30 is molded on the transparent light guide plate 20 by the light emitting diode 30, heat conduction in the entire area of the mold 11 is also promoted, and a situation where only the vicinity of the light emitting diode 30 is heated is prevented. be able to.
[0042]
Light diffusely reflected in various directions in the mold 11 is averaged in the transparent light guide plate 20 and then travels toward the upper surface side where the mold 11 is opened, but is evenly distributed by passing through the light dispersion resin 50. The light is emitted and irradiated to the outside from the entire emission surface 51 at the upper end of the light dispersion resin 50. In the light dispersion resin 50, since the light is finely diffusely reflected in various directions, the staying time of the light becomes long, so that the variation in luminance is further eliminated.
[0043]
Thereby, uniform light emission with high luminance can be obtained from the emission surface 51 of the light dispersion resin 50 covering the opening of the mold 11. Such surface light emission has various angle components of light, and can be easily visually recognized from an angular direction that is an acute angle with respect to the emission surface 51 of the light dispersion resin 50 or from a location far away. Further, since the light dispersion resin 50 is mixed with a colorant having the same color as the light emission color of the light emitting diode 30, light with a clearer and more vivid color can be obtained.
[0044]
In the present embodiment, the light-reflecting paint 12 is a white paint, and the beads 13 are colorless and transparent glass spheres. Excellent light reflection efficiency and optical irregular reflection efficiency can be obtained.
[0045]
Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these various embodiments, and changes and additions may be made without departing from the scope of the present invention. It is included in the present invention. For example, the shape and size of the display light source device 10 and the arrangement pattern of the plurality of light emitting diodes 30 are not limited to those illustrated.
[0046]
【The invention's effect】
According to the light source device for display according to the present invention, it has a long life compared with a fluorescent lamp, a neon sign tube, etc., has extremely high visibility and brightness, and is not thermally or discharge-emitting, so that the turn-on and turn-off time is fast. Light-emitting diode characteristics such as low power consumption and high shock resistance due to high conversion efficiency, and non-uniform light / darkness of light do not occur, and high brightness and uniform surface light emission with low power consumption [Brief description of the drawings]
FIG. 1 is an enlarged longitudinal sectional view showing a part of a display light source device according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a display light source device according to an embodiment of the present invention.
FIG. 3 is a plan view showing the light source device for display according to the embodiment of the present invention with a part cut away.
FIG. 4 is an operation explanatory diagram illustrating light irradiation in the display light source device according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Display light source device 11 ... Formwork 12 ... Light-reflective coating 13 ... Bead 20 ... Transparent light guide plate 30 ... Light emitting diode 31 ... Light emitting element 32 ... Lead wire 40 ... Resin adhesive 50 ... Light dispersion resin 51 ... Output surface

Claims (2)

In a display light source device that can obtain uniform surface light emission using a light emitting diode as a light source,
A transparent light guide plate pre-formed into a plate shape with a transparent and translucent resin, a mold that matches the transparent light guide plate, and has an open top surface, and is also transparent and translucent on the transparent light guide plate A light emitting diode adhered in a predetermined arrangement by a resinous adhesive, and a light dispersion resin laminated on the light emitting diode and the resinous adhesive,
The mold is formed to a depth corresponding to the total thickness of the transparent light guide plate fitted inside, the light emitting diode and the resinous adhesive, and the light dispersing resin, and is formed on the entire inner surface. A light-reflecting paint having a high light-reflecting efficiency is applied, and when the light-reflecting paint is in a dry state, a large number of beads are sprayed on the application surface, thereby causing optical irregular reflection using the light-reflecting paint as an adhesive medium. A lot of urging beads are attached,
The light emitting diode is composed of a chip LED, the irradiation side of the light emitting element is opposed to the bottom surface of the mold, and a plurality of light emitting diodes are arranged on the transparent light guide plate at a predetermined interval on the plane,
The resinous adhesive is laminated on the transparent light guide plate in a state in which the light emitting diode can be entirely covered in the thickness direction,
The light source device for display, wherein the light dispersion resin is laminated on the resinous adhesive so as to cover an opened upper surface side of the mold.   2. The display light source device according to claim 1, wherein the light-reflecting paint is a white paint, and the beads are colorless and transparent glass spheres.

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