JP2010033861A - Led illumination panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED illumination panel which can achieve a large size exceeding 1.2 m while being an edge light type. <P>SOLUTION: The LED illumination panel is provided with a plurality of light guide plates (11, 12) which are laminated in irradiation direction of light and have a length exceeding a distance in which the light is attenuated to a prescribed intensity or less in the optical propagation direction, a plurality of LEDs (15, 16) which are installed at end face in the optical propagation direction of each of the plurality of light guide plates and introduce light into the light guide plates, and a plurality of reflection sheets (17, 18) which are installed in the mutually different regions on the rear side of each of the plurality of light guide plates and have a length shorter than the distance in which the introduced light is attenuated to a prescribed intensity or less in the optical propagation direction, and reflect the propagating light to the front. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an LED lighting panel, and more particularly to a panel that can realize an increase in size exceeding a distance at which light attenuates to a predetermined intensity or less, although it is an edge light system.

  Recently, high-brightness LEDs with low power consumption and excellent durability have been put to practical use, so high-brightness LEDs are used as the light sources for lighting panels such as electrical panels, emergency lights, guide lights, and signs. At the same time, energy conservation and maintenance-free efforts are being made.

  Conventionally, this type of LED lighting panel employs a backlight system in which a base is provided behind the light guide plate, a plurality of LEDs are arranged vertically and horizontally, and light is emitted from the back of the light guide plate (Patent Document 1). . However, in the backlight method, if an attempt is made to produce a large lighting panel, the number of necessary LEDs becomes enormous, resulting in an increase in cost and an increase in thickness.

  In addition, an edge light is provided in which an LED is provided on the end face of the light guide plate, light is introduced into the light guide plate from the side to propagate through the light guide plate, and at that time, the light is reflected forward by the reflecting portion on the back surface of the light guide plate. A method has been developed and put into practical use (Patent Documents 2 and 3).

JP 2008-107745 A JP 2007-073206 A JP 2007-163663 A

  Edge-lighted lighting panels have the advantage of being thin and reducing the number of required LEDs, but the light is attenuated while propagating through the light guide plate. The maximum length is 1.2 m, and there is a problem that it is difficult to increase the size.

  This invention makes it a subject to provide the LED lighting panel which enabled it to implement | achieve the enlargement exceeding 1.2 m, although it is an edge light system in view of this problem.

  Therefore, an LED lighting panel according to the present invention is laminated in the light emission direction, and a plurality of light guide plates having a length exceeding a distance at which light attenuates to a predetermined intensity or less with respect to the light propagation direction, The plurality of LEDs that are provided on the end surfaces in the light propagation direction of the respective light guide plates, and are provided in different areas on the back side of the plurality of light guide plates, and the plurality of LEDs that enter the light inside the light guide plates. A plurality of reflection sheet portions that have a length shorter than a distance that attenuates to a predetermined intensity or less with respect to the light propagation direction and reflect the propagating light forward are characterized.

  One of the features of the present invention is that a plurality of large-sized light guide plates are stacked, a reflection sheet portion is provided in a different region of each of the plurality of light guide plates, and light propagating through the plurality of light guide plates is reflected by the reflection sheet portion for illumination. This is because the entire surface of the panel is made to emit light.

  Accordingly, the dimensions of the LED lighting panel can be freely increased regardless of the attenuation of light during light reflection, while having the advantage of the edge light method that the thickness is thin and the number of necessary LEDs can be reduced.

  In the above description, the light guide plate is laminated in the light emission direction. However, the same effect can be obtained even when the end portions are arranged in the light propagation direction. However, in this case, it is not preferable that the joint of the light guide plate is clearly visible from the outside. Therefore, a surface panel is provided to make the joint difficult to see.

  The LED lighting panel according to the present invention is provided with a plurality of light guide plates that are arranged in the light propagation direction and overlapped with the ends, and have a length shorter than a distance at which light attenuates to a predetermined intensity or less with respect to the light propagation direction. An LED that is provided on an end surface in the light propagation direction of each of the plurality of light guide plates, and that enters light into the light guide plate, and is provided on the back side of each of the plurality of light guide plates, and the incident light is in the light propagation direction. A plurality of reflection sheet portions that have a length shorter than a distance that attenuates below a predetermined intensity and reflects the propagating light forward, and a front panel that covers the front of the plurality of light guide plates arranged above , Provided.

  Although the LED lighting panel is manufactured in a single plate shape, as described above, when the end portions of the light guide plate are overlapped, the LED lighting panel may be thick. Therefore, it is preferable that the ends in the light propagation direction overlapped with each other bend with a curvature that does not impede the propagation of light. The degree of curvature depends on the wavelength of the light of the LED and the thickness of the light guide plate, and is preferably obtained by experiments.

  The light propagating through the light guide plate is reflected forward by the light reflecting sheet portion. However, in order to improve the light reflection efficiency, it is preferable to form the light reflecting dot portion on the back surface of the light guide plate. When the light reflecting dot portion is on the end side in the light propagation direction, it is attenuated and weakened by light. Therefore, it is preferable to increase the dot density or the dot area as the light propagation direction is reached. The light reflecting dot portion may be formed by laser processing or the like, or may be formed by screen printing or the like.

  When an LED lighting panel is configured, a light diffusion plate is preferably laminated on the uppermost light guide plate surface among the laminated light guide plates. In addition, when the light guide plates are arranged in the light propagation direction, it is preferable to overlap the light diffusion plate on the surface of the light guide plate.

  The light guide plate and the light diffusing plate are not particularly limited as long as they are materials having sufficient translucency, and thermoplastic resins and thermosetting resins such as acrylic resins and polycarbonate resins can be employed. In the case of a light diffusing plate, a light scattering agent in the base resin, for example, inorganic fine particles such as calcium carbonate, barium sulfate, alumina, titanium dioxide, silicon dioxide, glass beads, organic fine particles such as styrene crosslinked beads, MS crosslinked beads, etc. These known fine particles can be employed.

  Moreover, LED (Light Emitting Diode; light emitting diode) may use red LED, blue LED, and green LED by a single color, and can also be used in combination.

  Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. 1 and 2 show a preferred embodiment of an LED lighting panel according to the present invention. The LED lighting panel 10 of this example is formed by laminating two light guide plates 11 and 12 having a length exceeding the distance at which propagating light is attenuated to a predetermined intensity or less, for example, twice as long as the upper light guide plate 11. A light diffusing plate 13 is superimposed on the surface, and a heat radiating plate 14 made of, for example, aluminum is superimposed on the lower side of the lower light guide plate 12.

  The light guide plates 11 and 12 and the light diffusing plate 13 are made of, for example, acrylic resin. A light scattering agent is dispersed in an appropriate amount on the light diffusing plate 13, and the light guide plates 11 and 12 have opposite end faces in the light propagation direction. An LED unit in which the LEDs 15 and 16 are arranged and a drive circuit is incorporated is provided so that light enters the light guide plates 11 and 12.

  In addition, light reflecting sheets 17 and 18 having a length equal to or less than a distance at which the propagating light attenuates to a predetermined intensity or less are provided on the back side of the left half of the light guide plate 11 and the right half of the light guide plate 12. In addition, light reflecting dot portions 11A and 12A are formed on the left rear half of the light guide plate 11 and the right rear half of the light guide plate 12 by, for example, laser processing, and the rear left half of the light guide plate 11 and the light guide plate 12 are formed. The light reflecting dot portions 11A and 12A are formed in the right half of the back surface, and the light reflecting dot portions 11A and 12A have a density or an area toward the center of the light guide plates 11 and 12 so that light reflection is uniform as a whole. Is formed to be large.

  When the LEDs 15 and 16 are driven by a drive circuit (not shown), light enters the light guide plates 11 and 12 from the side, and the light propagates through the light guide plates 11 and 12. In the upper light guide plate 11, in the region where the light reflecting sheet portion 17 is not provided, the light propagates only between the upper and lower interfaces and is not attenuated so much. In the region where the light reflecting sheet portion 17 is provided, light is reflected by the propagating light. It is reflected forward by the dot portion 11A and the light reflecting sheet portion 17, diffused by the light diffusion plate 13, and emitted forward. In particular, since the density or area of the light reflecting dot portion 11A increases as the distance from the LED 15 increases, the light is reflected substantially evenly in the entire region where the light reflecting sheet portion 17 is provided. .

  Similarly, in the light guide plate 12 on the lower side, in the region where the reflection sheet portion 18 is not provided, light is propagated only between the upper and lower or left and right boundary surfaces and is not attenuated so much, and in the region where the light reflection sheet portion 18 is provided. The light is uniformly reflected forward by the light reflecting dot portion 12 </ b> A and the light reflecting sheet portion 18, passes through the light guide plate 11, is diffused by the light diffusion plate 13, and is emitted forward.

  As a result, even if it is a large sized LED lighting panel 10, the whole surface of the light-diffusion board 13 can be light-emitted substantially uniformly, and, thereby, a large sized and thin LED lighting panel can be manufactured.

  FIG. 3 shows a second embodiment. In this example, three light guide plates 21, 22, and 23 having a length exceeding the distance at which the propagating light is attenuated to a predetermined intensity or less, for example, three times the length, are laminated, and the light diffusion plate 24 is placed on the surface. On the side, a heat radiating plate 25 is provided, and a light reflecting dot portion (not shown) is laser-processed in the region of the right side 1/3, the center 1/3, and the left side 1/3 of the rear surface of each light guide plate 21, 22, 23. In addition, the light reflecting sheet portions 29, 210, and 211 are provided on the back side thereof. Thus, by laminating three light guide plates 21 to 23, the LED thin film is larger than the first embodiment. Can produce lighting panels.

  In the LED lighting panel 20 of this example, since light is reflected in the region where the light reflecting sheet portions 29 to 211 are provided, the entire surface of the LED lighting panel 20 larger than the first embodiment is caused to emit light. Can do.

  4 to 6 show a third embodiment. In this example, a large LED lighting panel 50 is manufactured using four short LED lighting panels 30, one long LED lighting panel 40, and a front panel 51.

  The front panel 51 is integrally manufactured using, for example, an acrylic resin, and characters and designs are printed on the front panel 51 according to applications.

  In the short LED lighting panel 30, for example, a reflector 32 having the same dimensions is laminated behind a light guide plate 31 of 530 mm × 1500 mm, and an LED unit 33 is attached to one end face of the light guide plate 31 and the reflector 32. Built-in row and drive circuit.

  In the long LED lighting panel 40, for example, a reflective plate 42 having the same dimensions is laminated behind a light guide plate 41 of 1100 mm × 1500 mm, and LED units 43 are attached to both opposite end faces of the light guide plate 41 and the reflective plate 42. Has a built-in LED array and driving circuit.

  The light guide plates 31 and 42 are made of, for example, acrylic resin to a thickness of 4 mm, and the back surface is formed so that the density or area of the light reflecting dot portion (not shown) increases as the distance from the LED increases. Moreover, the reflecting plates 32 and 42 are manufactured to a thickness of 4 mm using, for example, an acrylic resin, and a light reflecting sheet (not shown) is provided on the surface.

  The four short LED lighting panels 30 are fixed by the column 52 so that a step is formed so as to be separated from the front panel 51 at the center side, and the end portions overlap so that the long LED lighting panel 40 comes to the center. Has been.

  In the LED lighting panel of this example, the end portions of the LED lighting panels 30 and 40 are overlapped with each other, but the seam is difficult to see from the outside because it is covered with the front panel 51, as if it were one LED lighting panel. appear.

  Further, an LED lighting panel of an arbitrary size can be manufactured by appropriately combining the short LED lighting panel 30 and the long LED lighting panel 40.

  FIG. 7 shows a modification of the third embodiment. In this example, the overlapping portions of the end portions of the LED lighting panels 30 and 40 are bent so that the thickness does not increase so much.

It is a schematic block diagram which shows preferable embodiment of the LED lighting panel which concerns on this invention. It is a principal part expanded block diagram which shows the said embodiment. It is a block diagram which shows 2nd Embodiment. It is a figure which shows the LED illumination panel used in 3rd Embodiment. It is a figure which shows the said embodiment. It is an enlarged view which shows the panel attachment part in the said embodiment. It is a figure which shows the modification in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 LED illumination panel 11, 12 Light guide plate 11A, 12A Light reflection dot part 13 Light diffusing plate 14 Heat sink 15, 16 LED
17, 18 Light reflection sheet part 20 LED illumination panel 21, 22, 23 Light guide plate 24 Light diffusion plate 25 Heat radiation plate 26, 27, 28 LED
29, 210, 211 Light reflection sheet part 30 Short LED illumination panel 31 Light guide plate 33 LED unit 40 Short LED illumination panel 41 Light guide plate 43 LED unit 50 LED illumination panel 51 Front panel

Claims (5)

A plurality of light guide plates stacked in the radiation direction of light and having a length exceeding a distance at which light attenuates to a predetermined intensity or less with respect to the light propagation direction;
A plurality of LEDs provided on an end surface in the light propagation direction of each of the plurality of light guide plates, and incident light into the light guide plate;
Provided in different areas on the back side of each of the plurality of light guide plates, the incident light has a length shorter than the distance at which the light is attenuated to a predetermined intensity or less in the light propagation direction, and the propagating light is forward A plurality of reflective sheet portions that reflect on
An LED lighting panel comprising: A plurality of light guide plates that are arranged in the light propagation direction and overlapped with the end portions, and have a length shorter than a distance at which light attenuates to a predetermined intensity or less with respect to the light propagation direction;
An LED that is provided on an end surface in the light propagation direction of each of the plurality of light guide plates, and that enters light into the light guide plate;
A plurality of light guide plates provided on the back side of each of the plurality of light guide plates, the incident light having a length shorter than a distance at which the light is attenuated to a predetermined intensity or less with respect to the light propagation direction, and reflecting the propagating light forward A reflection sheet,
A surface panel covering the front of the plurality of light guide plates arranged;
An LED lighting panel comprising:   3. A light reflecting dot portion is formed on the back surface of the plurality of light guide plates, and the light reflecting dot portion has a dot density or a dot area that increases in the light propagation direction. LED lighting panel.   The LED lighting panel according to claim 1, wherein a light diffusion plate is laminated on a surface of the uppermost light guide plate among the laminated light guide plates.   The LED lighting panel according to claim 2, wherein a light diffusion plate is laminated on the surface of the plurality of light guide plates arranged.

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