JP2006012906A - Display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display which can be kept from such a problem that dark parts of an image become whitish by reflection of light and can prevent overheating of light emitting elements. <P>SOLUTION: A plurality of light emitting elements 12 are arranged in an orderly manner on a substrate 11, and a translucent waterproof board 15 is arranged on the front surface side of the substrate 11 so as to cover the light emitting elements 12. A space between the light emitting elements 12 and the waterproof board 15 consists of a translucent material 20 which has a material density closer to that of the surface of the light emitting elements 12 or to that of the waterproof board 15 than to that of the air, and is softer than the light emitting elements 12 and waterproof board 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device, and more particularly to a display device that forms a large screen by arranging a plurality of light emitting elements at a predetermined pitch.

  This type of display device that configures a large screen by arranging light emitting elements such as LEDs (Light Emitting Diodes) in a matrix at a predetermined pitch can be used in outdoor environments such as event venues, sports facilities, and building wall surfaces. In many cases, the use of segmented display units facilitates relocation, and because it is also installed in buildings as town media, etc., there are high demands on image quality and resolution.

  As a conventional display device of this type, for example, there is one in which an antireflection film is provided on a cup portion to which an LED diode chip is bonded so as to prevent a decrease in contrast due to reflection of external light (for example, Patent Documents). 1).

  In addition, in order to meet the demand for high image quality and high resolution, there is one that employs a surface mount type LED in which RGB light emitting elements are integrally embedded (see, for example, Patent Document 2).

In the case of a conventional display device, particularly in the case of a surface mount type, it is common to cover the front surface side of the device, which is a display element mounting surface, with a waterproof cover made of a transparent resin plate (for example, polycarbonate), and a viewing angle. In consideration of the above, each LED or each LED array line is configured to be partitioned by a bowl-shaped member such as a black resin.
JP 2001-345484 A JP 2003-168828 A

  In the conventional display device, not only the surface of the transparent resin plate constituting the front waterproof cover, but also the interface between the back surface of the resin plate and the air layer on the LED side, and further, the air layer and the LED surface Reflection of light occurs at the interface of each. For this reason, there has been a problem that black color floats on the display screen when the display device is used in a bright environment.

  In addition, an air layer is formed between the LED and the nearby saddle-shaped member and the waterproof cover, and this air layer has a heat insulating effect, so that the temperature of the LED driven to emit light is very high. . For this reason, there is a problem that the LED chip portion is easily damaged such as deterioration and surface peeling, and the color reproducibility is lowered due to the red LED characteristic in which the luminance is greatly lowered due to the temperature rise.

  The present invention has been made to solve such problems of the prior art, and aims to suppress black floating due to light reflection, to prevent deterioration and damage due to overheating of the light emitting element, and to improve color reproducibility. .

  In the display device of the present invention, a plurality of light emitting elements are arranged side by side on a substrate, a translucent waterproofing plate is disposed on the front side of the substrate so as to cover the light emitting elements, and the light emitting element, the waterproofing plate, The space is formed of a light-transmitting material that is closer to the surface of the light emitting element and the waterproof plate than air and is softer than the light emitting element and the waterproof plate.

  With this configuration, there is no air layer between the light emitting element and the waterproof board, and light reflection on the back surface of the waterproof board and light reflection on the light emitting element surface are suppressed. In addition to the absence of an air layer serving as a heat insulating layer, heat conduction to the translucent material is possible, so that overheating of the light emitting element is prevented. Here, the term “soft” means that the hardness is low, and includes cases where the material is made of a fluid material (when it has a specific viscosity or consistency).

  It is preferable that the translucent material is made of a transparent resin having a density close to both the light emitting element and the waterproof board. In this case, the translucent material has a refractive index close to that of both the light emitting element and the waterproof board, and reflection of light at these interfaces is suppressed.

  In addition, when the translucent material is a silicone resin, the translucent material has stable physical properties and is easy to handle. When the translucent material is in a gel form, the translucent material transmits light between the light emitting element and the waterproof plate. The work of filling with the material becomes easy, and peeling due to temperature change is prevented.

  In the display device of the present invention, a coating layer serving as an antireflection film is further provided on the front surface of the waterproof board, and light reflected by the surface of the coating layer and light reflected between the coating layer and the waterproof board are provided. The coating layer is preferably prepared so as to cancel each other.

  In this case, reflection of light on the surface of the waterproof board is effectively suppressed.

  More preferably, a plurality of chambers for accommodating the light-transmitting material are formed by arranging non-transparent side wall members surrounding the light-emitting elements between the waterproof plate and the substrate, respectively.

  In this case, since the side wall member surrounds a plurality of the light emitting elements, it can also be used for supporting the waterproof plate, and the black light is suppressed by the light shielding effect of the side wall member, and a plurality of chambers (between the plurality of light emitting elements and the waterproof plate) are provided. Further, the work of uniformly filling or arranging the translucent material can be facilitated.

  According to the present invention, reflection of light on the back surface of the waterproof board and reflection of light on the surface of the light emitting element can be suppressed, and deterioration of image quality such as black floating in a bright environment can be prevented. In addition to eliminating the air layer serving as a heat insulating layer with the light transmissive material, overheating of the light emitting element can be reliably prevented by utilizing the heat conduction of the light transmissive material.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 is a partial side sectional view showing a schematic configuration of a display device according to an embodiment of the present invention, FIG. 2 is a partial front view thereof, and FIG. 3 is a sectional view in the direction of arrows III-III in FIG. 4 is a cross-sectional view in the direction of arrows IV-IV in FIG.

  In FIG. 1, reference numeral 11 denotes a substrate, and reference numeral 12 denotes a plurality of light emitting elements arranged in parallel on the substrate 11. The substrate 11 has a light emitting element 12 mounted on the front side and a semiconductor chip (not shown) for controlling light emission of the light emitting element 12 on the back side. The light emitting elements 12 are arranged in a matrix on the substrate 11 with a predetermined pitch, and constitute each picture element in the entire screen. The predetermined pitch is, for example, 10 mm or less.

  The light emitting element 12 is a composite light emitting element in which, for example, three LED chips corresponding to three primary colors of R (Red), G (Green), and B (Blue) are integrated into a single component shape.

  The substrate 11 and the light emitting element 12 are detachably supported by the unit case 10 as shown in FIGS. 2 to 4 and constitute a part of a display unit (the entire configuration is not shown) of a predetermined size. . The display unit can be combined as a plurality of segments to construct a large color display screen of a desired size.

  On the other hand, on the front side of the substrate 11, a waterproof plate 15 having a light transmitting property (light transmitting property) is disposed so as to cover the plurality of light emitting devices 12, and between the light emitting device 12 and the waterproof plate 15. A light-transmitting material 20 having physical properties closer to the surface of the light emitting element 12 and the material of the waterproof board 15 than air is provided. The translucent material 20 is made of a material that is softer than the light emitting element 12 and the waterproof plate 15, that is, has a lower hardness, and is in close contact with the surface portion 12 a of the light emitting element 12 and the back surface (inner surface) portion of the waterproof plate 15. Is formed. Note that a transparent cover (not shown) is usually attached integrally to the surface portion 12 a of the light emitting element 12.

  The translucent material 20 is made of a non-translucent resin having a density close to both the surface portion 12a of the light emitting element 12 and the material of the waterproof plate 15, for example, a colorless and transparent gel silicone resin. Of course, the material is not limited to gel, and any flexible and transparent material having good adhesion to the front surface portion 12a of the light emitting element 12 and the rear surface portion of the waterproof plate 15 can be used, and such adhesion is ensured. However, a gel-like transparent material having a predetermined viscosity or consistency that is easy to handle may be cured to some extent up to the predetermined hardness.

  Further, the front surface of the waterproof plate 15 is provided with a coating layer 15a serving as an antireflection film. The light reflected on the surface of the coating layer 15a and the front surface of the coating layer 15a and the waterproof plate 15 (the back surface of the coating layer). The coating layer 15a is prepared so that the light reflected between the two layers cancels each other out of phase (reverse phase). The coating layer 15a is formed by laminating a plurality of antireflection film layers having different characteristics from each other so as to suppress reflection with respect to light (red, blue, green, etc.) in a predetermined frequency range.

  Further, a side wall member 17 surrounding the light emitting element 12 is provided on the substrate 11 between the light emitting element 12 and the waterproof plate 15. The side wall member 17 includes a plurality of pairs of flanges 17a, 17b, and 17c extending in parallel to a predetermined direction (X direction in FIG. 2) that is the first scanning direction during screen display, and the flanges 17a to 17c. It consists of connecting parts 17d, 17e, and 17f that connect 17c to each other.

  Further, the side wall member 17 is made of a non-translucent resin, for example, a black weather resistant resin, and the flange portions 17 a to 17 c are higher than the light emitting element 12 on the substrate 11. In other words, the flanges 17a to 17c are located on both sides of the light emitting element 12 (when assuming an installation state in which the screen is almost vertical), thereby suppressing black floating by a light shielding effect and in a bright environment. It enables viewing of clear images.

  In the display device of this embodiment configured as described above, the translucent material 20 is in close contact with the front surface portion 12a of the light emitting element 12 and the back surface portion of the waterproof plate 15, and has a density (light emission) closer to these than air. (Refractive index close to the front surface portion 12a of the element 12 and the rear surface portion of the waterproof plate 15), the reflection of light at the back side interface of the waterproof plate 15 and the reflection of light at the surface portion of the light emitting element 12 are performed. Can be effectively suppressed. Therefore, it is possible to prevent a deterioration in image quality such as black floating in a bright environment.

  Further, due to the presence of the light-transmitting material 20, the space between the front surface portion of the light emitting element 12 and the back surface portion of the waterproof board 15, and the remaining space between the substrate 11 surrounding the light emitting element 12 and the waterproof board 15, Since the light-transmitting material 20 is used instead of the air layer, the light-emitting element 12 can be reliably prevented from being overheated by heat conduction to the light-transmitting material 20.

  Further, in the present embodiment, since the light-transmitting material 20 is a silicone resin, the physical properties are stable and easy to handle, and the light-transmitting material 20 is in a fluid gel form at least during filling and forming. Therefore, the work of filling the space between the light emitting element 12 and the waterproof plate 15 with the light transmissive material 20 is facilitated.

  In the present embodiment, the connecting portions 17 d to 17 f of the side wall member 17 are made higher than the surface portion 12 a of the light emitting element 12, and the substrate 11 and the waterproof plate 15 are surrounded by the side wall member 17. Since a plurality of spaces 25 (chambers) having a relatively small volume are formed therebetween, for example, gel-like translucent materials are simultaneously injected or applied into the plurality of spaces 25 for each row in which the light emitting elements 12 are aligned, The translucent material 20 can be filled and formed between the light emitting element 12 and the waterproof plate 15.

  In this case, it is necessary to provide the gel filling holes 15b and 15c of the translucent material 20 (or a part of the exhaust holes 15b and 15c) in a part of the waterproof plate 15 forming each filling space 25. However, if the holes 15b and 15c are sealed by the light-transmitting material 20 after filling (may be a light-transmitting light-transmitting material 20 whose hardness has increased to some extent from that at the time of filling), The light reflection on the surface 15 can be reliably suppressed, and the required waterproof performance can be ensured.

  As described above, since the side wall member 17 is formed between the waterproof plate 15 and the substrate 11 so as to surround the plurality of light emitting elements 12 and form a storage space for the translucent material 20, the translucent material 20 is inserted into the space 25. The work can be easily performed with a normal dispenser or the like, and the viewing angle is set within a preferable range by using the flange portions 17a to 17c which are part of the side wall member 17 or further using the connecting portions 17d to 17f. Can be set. As a result, a display device capable of obtaining a preferable display image can be provided.

1 is a partial side sectional view showing a schematic configuration of a display device according to an embodiment of the present invention. The partial front view of the display apparatus which concerns on one Embodiment of this invention Sectional view in the direction of arrows III-III in FIG. Sectional view in the direction of arrows IV-IV in Figure 2

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Board | substrate 12 Light emitting element 15 Waterproof board 15a Coating layer 17 Side wall member 17a, 17b, 17c Gutter part 17d, 17e, 17f Connection part 20 Translucent material 25 Space (chamber)

Claims (6)

A plurality of light emitting elements are juxtaposed on the substrate,
A translucent waterproof plate is disposed on the front side of the substrate so as to cover the light emitting element,
The space between the light emitting element and the waterproof plate is formed of a light-transmitting material that is closer to the surface of the light emitting element and the waterproof plate than air and is softer than the light emitting element and the waterproof plate. Characteristic display device. The display device according to claim 1, wherein the translucent material is made of a thermosetting resin. The display device according to claim 2, wherein the translucent material is a silicone resin. The display device according to claim 2, wherein the translucent material is in a gel form. A coating layer serving as an antireflection film is provided on the front surface of the waterproof board, and the coating layer is prepared so that light reflected on the surface of the coating layer and light reflected between the coating layer and the waterproof board cancel each other. The display device according to claim 1, wherein the display device is a display device. 2. A plurality of chambers for accommodating the light-transmitting material are formed by arranging non-transparent side wall members respectively surrounding the plurality of light-emitting elements between the waterproof plate and the substrate. The display device according to claim 5.

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