JP4828253B2 - Light emitting unit used as light source for backlight for liquid crystal - Google Patents

Description

The present invention relates to a light emitting unit used as a light source of a backlight for liquid crystal .

  Conventionally, as a backlight light source for a liquid crystal display, a so-called edge light type in which a cold cathode tube is arranged on an end face of a casing has been mainstream. However, the edge-light type has limitations in improving luminance and making the luminance uniform, and it is difficult to meet the demand for larger display screens. The use of type lights is being considered.

  On the other hand, among light-emitting elements whose luminous efficiency has been remarkably improved in recent years and applied to illumination, a light-emitting diode (also referred to as an “LED lamp”) is a backlight light source (surface light source) for a direct liquid crystal display. It is also considered to be used as

  If such a light emitting diode is used as a backlight light source for a liquid crystal display, it is possible to meet the demand for larger display screens and to achieve good color reproducibility and high-speed response, achieving high quality image quality. Is expected to be.

FIG. 3 shows a part of a conventional backlight light source using such a light emitting diode as a direct light (Patent Document 1).
In the component 30 of the backlight light source, the LED lamps 12 are linearly arranged on the wiring board 19. Further, in the component 30, since a large amount of heat is generated by providing a large number of LED lamps 12, a heat radiating plate 24 is disposed on the back side of the wiring board 19, and heat is radiated to the outside through the heat radiating plate 24. Has been done.

  By the way, in order to attach the wiring board 19 provided with a large number of LED lamps 12 to the heat radiating plate 24, a large number of mounting screws 28 are used. Further, a light source plate, a frame member, and the like (not shown) are assembled to constitute a surface light source device for the backlight.

  In such a component 30 of the conventional backlight light source, the wiring board 19 and the heat sink 24 are integrated by using a large number of mounting screws 28. Therefore, the larger the display device, the larger the number of work steps. There was also a problem of increased weight.

  Further, if the thickness of the wiring board 19 is reduced, the wiring board 19 may be chipped by the mounting screws 28 or the wiring board 19 may be screwed during the mounting work unless the tightening operation is performed under torque management. There was a problem of deformation with a weight of 28.

Further, when trying to arrange the LED lamps 12 at a predetermined interval, there is a problem that the LED lamps 12 need to be accurately positioned and the assembling workability becomes complicated.
JP 2005-316337 A

The present invention has been made in view of such a situation. For example, the present invention is used as a light source of a backlight for a liquid crystal display that can easily attach a light emitting device package and a wiring board without increasing the weight. It is an object to provide a light emitting unit that can be used .

In order to solve the above problems, the present inventors have found a light emitting unit used as a light source of a liquid crystal backlight of the present invention.

That is, the present invention includes, for example, the following aspects (1) to ( 3 ).
(1) A light source of a backlight for liquid crystal in which a concave portion is formed on one main surface of a plate body, and the package of the light emitting element is accommodated in the concave portion, whereby the plate body and the package are integrally assembled. A light emitting unit used as
The recess has a shape that is substantially complementary to the package and has an asymmetry in its external shape, and a plurality of the recesses are formed at predetermined intervals in the vertical and horizontal directions . A light- emitting unit used as a light source of a backlight for liquid crystal, wherein a hole penetrating the other main surface of the plate is formed .
(2) The liquid crystal according to (1), wherein the light emitting element package is a three-in-one type light emitting element package in which three types of light emitting elements of red, green, and blue are combined into one. Light- emitting unit used as a light source for industrial backlights .
(3) The liquid crystal according to (1) or (2), wherein the package of the light emitting element is formed by combining at least one of three types of light emitting elements of red, green, and blue. Light-emitting unit used as a light source for industrial backlights.

According to the light emitting unit used as the light source of the backlight for liquid crystal according to the present invention, the mounting work of the light emitting element package and the plate becomes easy, and the weight does not increase. Further, if a light guide plate or the like is disposed so as to be in contact with the plate body, it can be preferably applied as a backlight light source of a large capacity liquid crystal display device .

It will be described in detail with reference to the drawings attached to the light emitting unit to be used as liquid crystal backlights for light source according to the present invention.
FIG. 1 is a plan view schematically showing a light emitting unit 10 according to an embodiment of the present invention.

The light emitting unit 10 includes a plate body 2 and a package 4 of LED light emitting elements incorporated in the plate body 2.
As the package 4 of the light emitting element, as shown in FIGS. 2A and 2B, for example, a single light emitting diode (LED) chip that emits light of three primary colors of red, green, and blue is packaged. In other words, a so-called three-in-one LED lamp that emits white light by mixing these colors can be suitably used. For example, such a three-in-one package 4 includes an LED chip 42 that emits red light of approximately 1 mm square and an LED that emits green light at the center of a substantially rectangular light emitting element mounting substrate 310 having an outer shape of several mm square. One chip 44 and one LED chip 46 that emits blue light are arranged close to each vertex of a substantially equilateral triangle. In addition, in the outer peripheral area of the LED chips 42, 44, 46, a reflector frame 48 having an opening 52 formed so as to be inclined toward the LED chips 42, 44, 46 so that the opening diameter becomes smaller. A surface having a small diameter is disposed so as to face the light emitting element mounting substrate 50 side, and an opening 52 of the reflector frame 48 is filled with a sealing resin 54 typified by an epoxy resin or a silicone resin. Yes.

  Such a three-in-one package 4 includes a reflector frame 48 that reflects and mixes the three colors of light emitted from the LED chips 42, 44, and 46, so that white light can be efficiently obtained. It has become. The light emitting device package 4 used in the present invention is not limited to the three-in-one type having the above-described configuration.

  The plate body 2 is not particularly limited as long as it can process the recess 2a, but it is preferable to use a metal having a high thermal conductivity from the viewpoint of workability and heat dissipation. Examples of the metal constituting the plate body 2 include aluminum, copper, brass, steel, and stainless steel. Among these, it is preferable to use aluminum. By using aluminum, the workability is good, the cost is low, the weight can be reduced, and the heat can be easily radiated to the outside.

  In addition, as a member other than a metal, for example, an engineering plastic or a composite material of metal and plastic can be used.

  On the other hand, a substantially rectangular recess 2a is formed on one main surface of the plate 2 at predetermined intervals in the vertical and horizontal directions. In the case where a metal such as an aluminum plate is used as the plate 2, the recess 2 a can be formed by a single process by pressing a substantially flat metal plate. Moreover, in order to form the recessed part 2a, it is not limited to press work, For example, you may form by die-casting and may form by cutting depending on the case. In addition, prepare two thin plate-like plates that are about half as thick, and form holes in one plate, do not form holes in the other plate, and stack these plates. They may be integrated together. However, forming by press working or die casting is inexpensive.

  When a resin such as engineering plastic is used as the plate body 2, it can be formed by molding.

  Such a recess 2a is preferably formed in a shape substantially complementary to the package 4 of the light emitting element incorporated therein. In this embodiment, one corner portion of the package 4 and the recess 2a is cut obliquely so that the assembled state of the package 4 with respect to the recess 2a is uniquely determined. That is, the outer shape of the recess 2a and the package 4 is formed in an asymmetrical shape. As a result, the package 4 is prevented from being installed in the wrong direction in the recess 2a by rotating. That is, the built-in state is uniquely determined.

  In the present embodiment, the light emitting unit 10 is configured by incorporating the package 4 of the light emitting element formed in advance into the recess 2 a of the plate 2. Further, when the light emitting element package 4 is accommodated in the recess 2a of the plate 2 and then a light guide plate made of, for example, acrylic resin is laminated thereon, a planar light source device is formed that spreads in a planar shape. When the wiring 6 is provided in the light emitting element package 4, a hole 8 is provided in the bottom of the recess 2 a in order to take out the wiring 6 to the outside of the plate 2, and the wiring 6 is connected from the hole 8. Take it out.

  As shown in FIG. 1, instead of providing a hole 8 from the other main surface of the plate body 2 to the bottom of the recess 2 a, the side surface of the recess 2 a penetrates to the outside (such as the other main surface of the plate body 2). A hole can also be provided.

Note that an adhesive sheet or the like may be interposed on the bottom surface of the recess 2a, and the metal plate 2 and the LED package 4 may be bonded with this adhesive sheet.
In this way, the light emitting unit 10 of the present embodiment is configured. A surface light source device using the light emitting unit 10 is suitable as a backlight light source for a large liquid crystal display.

  According to the light emitting unit 10 of this embodiment, the bottom surface of the light emitting element package 4 and the metal plate 2 are in full contact with each other. Can be actively dissipated to the outside by the plate body 2 that also serves as a heat sink.

  As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example at all. For example, in the above embodiment, the light emitting element package 4 is formed in a substantially rectangular shape, but this shape is not limited to a rectangular shape. A basic shape such as a circle or an ellipse may be used. However, when positioning is taken into consideration, it is preferable to set it to be asymmetry itself. In consideration of the case where the LED light emitting element package 4 is partially replaced in the surface light source device, a small hole 2b is provided from the back surface (the other main surface) side of the plate body 2 to the bottom surface of the recess 2a. If so, the package 4 can be easily taken out and replaced by inserting a pin or the like through the small hole 2b from the opposite side.

  In the present embodiment, the case where a so-called three-in-one package in which LED elements having different emission colors (red LED, green LED, and blue LED) are combined into one is used is illustrated. It is not limited, A monochromatic LED element may be sufficient. Moreover, you may combine three or more types of light emitting elements of red, green, and blue, respectively. Furthermore, when using the LED element from which luminescent color differs, it is not limited to the case of three colors of red, green, and blue.

In addition, even if the LED package 4 is accommodated in the recess 2a, the recess 2a can be sealed with an epoxy resin, a silicone resin, or the like if a slight gap is formed.
Further, in the above-described embodiment, an example is shown in which the packages 4 are arranged at predetermined intervals in the vertical and horizontal directions and spread in a planar shape, but these do not necessarily have to be arranged on a straight line. They can be arranged in a zigzag pattern or can be slightly shifted from a straight line.

  Moreover, in the said Example, although the recessed part 2a is formed separately for every predetermined space | interval, the continuous linear groove | channel can be formed and a part of the groove | channel can also be comprised as the recessed part 2a. In that case, if an appropriate spacer is interposed between one package 4 and the adjacent package 4, they can be arranged separated by a predetermined distance.

FIG. 1 is an exploded perspective view showing a part of a light emitting unit according to an embodiment of the present invention. FIG. 2 is a schematic view of a three-in-one package, FIG. 2A is a plan view, and FIG. 2B is a cross-sectional view taken along line XX of FIG. FIG. 3 is a perspective view showing components of a surface light source device incorporating a conventional light emitting unit.

Explanation of symbols

2 Plate 2a Recess 2b Small hole 4 LED light emitting element package 6 Wiring 8 Small hole 10 Light emitting unit 42, 44, 46 LED chip 48 Reflector frame 50 Light emitting element mounting substrate 52 Opening

Claims (3)

A concave portion is formed on one main surface of the plate body, and the package of the light emitting element is accommodated in the concave portion, thereby being used as a light source for a liquid crystal backlight in which the plate body and the package are integrally assembled. A light emitting unit,
The recess has a shape that is substantially complementary to the package and has an asymmetry in its external shape, and a plurality of the recesses are formed at predetermined intervals in the vertical and horizontal directions . A light- emitting unit used as a light source of a backlight for liquid crystal, wherein a hole penetrating the other main surface of the plate is formed . The liquid crystal backlight according to claim 1, wherein the light emitting device package is a three-in-one type light emitting device package in which three types of light emitting devices of red, green, and blue are combined into one. A light emitting unit used as a light source . 3. The light source of the backlight for liquid crystal according to claim 1, wherein the package of the light emitting element is formed by combining at least one of three kinds of light emitting elements of red, green, and blue. The light emitting unit used.

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