JP5108297B2 - Light emitting element mounting package, surface light source device, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting element mounting package, a surface light source device, a display, and a manufacturing method thereof, capable of emitting white light by mixing the color of light emitted from light emitting elements of the light emitting element mounting package consisting of a plurality of light emitting elements, and capable of evenly expanding the light in lateral direction, suppressing a production cost. <P>SOLUTION: In a light emitting element mounting package, a plurality of kinds of light emitting elements having different emission colors are mounted on a light emitting element mounting substrate, with a lens having a recess on its upper surface provided to the upper part of the light emitting element. The light emitting element is mounted at the position offset from the center position of the recess of the lens. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

The present invention relates to a light emitting element mounting package, a surface light source device, and a display device on which a light emitting element useful as a light source for illumination or a backlight for a liquid crystal display is mounted.

More specifically, the present invention relates to a light emitting element mounting package, a surface light source device, and a display device that are useful as a white light source.

  Conventionally, a backlight light source for a liquid crystal display has been mainly a so-called edge light type in which a cold cathode tube is disposed on an end face of a casing as a light source in order to reduce the thickness and reduce power consumption.

As such an edge light type backlight light source, the one having the structure shown in FIG. 9 is used.
That is, in the edge light type backlight light source 100, the cold cathode tube 104 is arranged at the end of the housing 102. A light guide plate 106 is disposed in a plane on the side of the cold cathode tube 104, and a diffusion sheet 108 is disposed on the upper surface of the light guide plate 106 to constitute the backlight light source 100.

Note that a reflective layer 116 made of, for example, minute unevenness or dot-shaped reflective ink is formed on the lower surface of the light guide plate 106.
The liquid crystal display device 112 is configured by disposing the liquid crystal panel 110 on the upper surface of the diffusion sheet 108 of the backlight light source 100.

  In this edge light type backlight light source 100, the light emitted from the cold cathode tube 104 is incident from the side portion 114 of the light guide plate 106 by causing the cold cathode tube 104 to emit light.

  The light incident on the light guide plate 106 is diffused while being repeatedly reflected inside the light guide plate 106 by the reflective layer 116 formed on the lower surface of the light guide plate 106, for example, made of minute unevenness or dot-shaped reflective ink. Thus, the light is uniformly guided above the light guide plate 106.

As a result, the light is uniformly diffused by the diffusion sheet 108, and the luminance unevenness of the liquid crystal panel 110 is reduced.
However, in recent years, demand for larger liquid crystal displays has increased, and such an edge-light type backlight light source 100 has limitations in improving and uniforming luminance.

For this reason, adoption of direct light is being studied for large liquid crystal displays.
However, when such a cold cathode tube is used as a direct light, the thickness of the liquid crystal display becomes large because the cold cathode tube is relatively large. Further, the cold cathode tube has problems such as poor color reproducibility and responsiveness and an afterimage phenomenon.

  For this reason, light emitting diodes (hereinafter referred to as “LEDs”) are used as backlight light sources (surface light source devices) for liquid crystal displays among light emitting elements whose light emission efficiency has been remarkably improved in recent years and whose application to illumination has advanced. ) Is under consideration.

By using the LED in this way, it is expected that good color reproducibility and high-speed responsiveness can be realized and high-quality image quality can be achieved.
For this reason, a direct type backlight light source in which a plurality of LEDs are arranged at regular intervals below the liquid crystal panel has been proposed.

As this direct type backlight light source, one having the structure shown in FIG. 10 has been proposed.
That is, in the direct type backlight light source 200, a plurality of LED lamps 206 are arranged on the bottom surface 204 of the casing 202 in an array at a predetermined interval.

  A diffusion sheet 208 is disposed on the upper surface of the housing 202 at a predetermined interval from the LED lamps 206, and a prism sheet 210 is disposed on the upper surface of the diffusion sheet 208, so that the backlight light source 200 is configured. Has been.

Note that a reflective layer 214 is formed on the bottom surface 204 and the side surface 212 of the housing 202 by, for example, a reflective sheet.
In the direct-type backlight light source 200 configured as described above, by emitting the LED lamp 206, the light emitted from the LED lamp 206 is directed directly toward the diffusion sheet 208 and the bottom surface 204 of the housing 202. The light travels toward the diffusion sheet 208 by being reflected by the reflective layer 214 on the side surface 212.

  The light incident on the diffusion sheet 208 is irregularly reflected by the diffusion sheet 208 and passes through the prism sheet 210 on the upper surface of the diffusion sheet 208, so that the light beam is tilted in the vertical direction and disposed on the upper surface of the prism sheet 210. It is incident on a liquid crystal panel (not shown).

  In addition, the light emitted from the LED lamp 206 is mixed in the space between the diffuser sheet 208 and further diffused in the diffuser sheet 208 to promote mixing, thereby making the luminance and chromaticity uniform. It has come to be.

  By the way, when an LED is used for such a direct type backlight light source, a light emitting diode (LED) chip that emits light of the three primary colors red, green, and blue is put in one package, and these are mixed. Therefore, a so-called three-in-one package LED lamp that emits white light is preferably used (see, for example, Non-Patent Document 1 (Stanley Electric Co., Ltd. website)).

  As shown in FIGS. 11 (a) and 11 (b), such a three-in-one package 300 is formed at a center of a substantially rectangular light-emitting element mounting substrate 310 having an outer shape of several millimeters square, approximately 0.3 mm. A 35 mm square LED chip 302 that emits red light, an LED chip 304 that emits green light, and an LED chip 306 that emits blue light are arranged close to each apex of a substantially equilateral triangle.

  In addition, a reflector frame 308 having an opening 312 formed so as to be inclined toward the LED chips 302, 304, and 306 is disposed in the outer peripheral area of the LED chips 302, 304, and 306. The reflector frame 308 is filled with a transparent sealing resin 314 typified by an epoxy resin or a silicone resin.

In such a three-in-one package 300, the light emission of the three colors emitted from the LED chips 302, 304, and 306 is reflected by the side surface of the opening 312 of the reflector frame 308, thereby improving the color mixture of these colors. White light can be easily obtained.

  As described above, the three-in-one package 300 is provided with the reflector frame 308 that reflects and mixes the three colors of light emitted from the LED chips 302, 304, and 306 so as to efficiently obtain white light. It is like that.

  However, since the surface light source device using such a three-in-one package 300 uses the reflector frame 308 for reflection and color mixing of emitted light, the luminance immediately above the LED chips 302, 304, and 306 tends to increase. It is in.

  In general, the reflector frame 308 is not transparent and has a white or metallic colored surface. Therefore, there is a problem that the light beam luminance decreases and the luminance decreases while light is repeatedly reflected.

In order to solve such a problem, in the conventional LED package 400 on which a single color LED chip is mounted, as shown in FIG. 12, the upper surface of the LED chip 402 has a funnel shape (funnel shape portion 406). Then, a lens 404 having a serrated outer periphery (saw-toothed portion 408) is provided, whereby the light emitted from the LED chip 402 is reflected by the funnel-shaped portion 406 and the saw-toothed portion 408, and the light irradiation area is set in the lateral direction. A device has been devised to widen and make the luminance and chromaticity uniform (Patent Document 1 (see Japanese Patent Laid-Open No. 2003-8068)).
Stanley Electric Co., Ltd. homepage, [online], Internet <http://www.stanley-components.com> JP 2003-8068 A

  However, the LED package using such a lens has been devised to refract the light hitting the funnel-shaped portion and the sawtooth-shaped portion provided on the lens, and to expand the light irradiation region in the lateral direction, Since the luminance and chromaticity immediately above the LED chip are still higher than those of other portions, it is impossible to completely suppress the occurrence of luminance unevenness and color unevenness.

In addition, complicated shapes such as funnel-shaped portions and sawtooth-shaped portions become a factor incurring high costs in producing lenses.
The lens is only used for an LED package on which a single-color LED chip is mounted, and does not correspond to an LED package on which a plurality of LED chips with different emission colors are mounted, so-called three-in-one package. Currently.

In view of such a current situation, the present invention mixes light emitted from each light emitting element of a light emitting element mounting package on which a plurality of light emitting elements having different emission colors are mounted, and spreads the light uniformly in the lateral direction. Accordingly, it is possible to provide a light-emitting element mounting package, a surface light source device, and a display device that can emit white light without unevenness in luminance and chromaticity and at a reduced production cost.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a light-emitting element mounting package, a surface light source device, and a display device of the present invention.
That is, the present invention includes, for example, the following aspects (1) to (8) .
(1)
A plurality of types of light emitting elements with different emission colors are mounted on a light emitting element mounting substrate,
A reflector frame having an opening is provided on the light emitting element so as to surround the light emitting element.
Furthermore, a light emitting element mounting package in which a lens having a concave portion on the upper surface is disposed on the upper portion of the opening of the reflector frame ,
The light emitting element is
A light emitting element mounting package, wherein the light emitting element mounting package is located at an outermost edge of the opening of the reflector frame and is mounted at a position between 20% and 95% of a radial distance from the center of the concave portion of the lens. .
(2)
The light emitting element is
The light emitting element mounting package according to (1) , wherein the light emitting element mounting packages are arranged on the light emitting element mounting substrate at equal intervals.
(3)
The light emitting element mounting package according to (1) or (2) , wherein the light emitting element is a light emitting diode (LED).
(4)
The light emitting diode mounting package according to (3) , wherein the light emitting diode (LED) is a light emitting diode (LED) chip.
(5)
The light emitting element mounting package according to any one of (1) to (4) , wherein a reflective portion is provided in the concave portion of the lens.
(6)
A surface light source device comprising the light emitting element mounting package according to any one of (1) to (5) .
(7)
The surface light source device according to (6) , wherein the surface light source device is a backlight for a display device.
(8)
A display device comprising a liquid crystal panel disposed on an upper surface of the surface light source device according to (6) or (7) .

According to the light emitting element mounting package, the surface light source device, and the display device of the present invention, the light emitted from each light emitting element of the light emitting element mounting package is mounted by mounting the light emitting element at a position deviating from the center position of the concave portion of the lens. By mixing the colors and spreading the light uniformly in the lateral direction, white light having no unevenness in luminance and chromaticity can be emitted, and the production cost can be reduced.

Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings. Note that the present invention is not limited to the following embodiments.
FIG. 1 is a diagram illustrating an overall configuration of an example of a typical liquid crystal display device to which the exemplary embodiment is applied.

  A liquid crystal display device to which the present embodiment is applied is a direct-type backlight device (backlight) 50, a backlight frame (housing) 51 that houses a light-emitting portion, and a light-emitting source that is a solid-state light-emitting element as a light-emitting source. An LED substrate (light emitting element mounting substrate) 52 is provided as a substrate on which a plurality of diodes (LEDs) are arranged.

  Further, the backlight device 50 is a laminated body of optical compensation sheets, a transparent diffusing member (plate, sheet) 53 that scatters and diffuses light in order to make the entire surface uniform brightness, and a forward light collecting effect. And prism sheets 54 and 55, which are diffraction grating films provided with.

  Further, as the liquid crystal display module 60, a liquid crystal panel 61 in which liquid crystal is sandwiched between two glass substrates, and a polarization layer that is laminated on each glass substrate of the liquid crystal panel 61 to limit the vibration of light waves in a certain direction. Plates (polarizing filters) 62 and 63 are provided. Further, peripheral members such as a driving LSI (not shown) are arranged in the liquid crystal display device.

  The liquid crystal panel 61 includes various components not shown. For example, two glass substrates are provided with a display electrode (not shown), an active element such as a thin film transistor (TFT), a liquid crystal, a spacer, a sealant, an alignment film, a common electrode, a protective film, a color filter, and the like. .

  The structural unit of the backlight device 50 is arbitrarily selected. For example, a unit of only the backlight frame 51 having the LED substrate 52 is referred to as a “backlight device (backlight)”, and a laminated body of optical compensation sheets such as a diffusing member (plate, sheet) 53 and prism sheets 54 and 55. There may be a distribution form that does not include.

  The backlight frame 51 forms a housing structure made of, for example, aluminum, magnesium, iron, or a metal alloy thereof. And the polyester film etc. which have the performance of white high reflection, for example are affixed inside the housing | casing structure, and the function as a reflector is provided.

  The housing structure includes a back surface portion corresponding to the size of the liquid crystal display module 60 and side surface portions surrounding the four corners of the back surface portion. In addition, a heat sink structure including cooling fins for exhaust heat may be formed on the back surface and the side surface as necessary.

  FIG. 2 is a schematic diagram illustrating a state in which LED chips of three colors are attached to a light emitting element mounting substrate used in the light emitting element mounting package according to the first embodiment of the present invention, and FIG. FIG. 2B is a cross-sectional view taken along line XX in FIG. FIG. 3 is a schematic view showing a state in which a reflector frame is disposed on a light emitting element mounting substrate used in the light emitting element mounting package according to the first embodiment of the present invention, and FIG. FIG. 3 and FIG. 3B are cross-sectional views taken along line XX in FIG. FIG. 4 shows a state in which a reflector frame is disposed on a light emitting element mounting substrate used in the light emitting element mounting package according to the first embodiment of the present invention, and a lens is disposed above the reflector frame. 4A is a top view, and FIG. 4B is a cross-sectional view taken along line XX in FIG. 4A.

  The light emitting device mounting package of the present invention is a luminance by mixing light emitted from each LED chip of the light emitting device mounting package on which a plurality of LED chips having different emission colors are mounted, and spreading the light uniformly in the lateral direction. It emits white light with no chromaticity unevenness.

  First, as shown in FIGS. 2A and 2B, such a light emitting element mounting package includes an LED chip 12 that emits red light, an LED chip 14 that emits green light, and an LED chip that emits blue light. A light emitting element mounting substrate 10a on which 16 three-color LED chips are mounted at a predetermined interval is prepared.

  The LED chips 12, 14, and 16 are formed on a metal base substrate or a metal foil such as copper or aluminum with good thermal conductivity so that the heat generated by the LED chips 12, 14, and 16 can be radiated to the outside. Further, it is adhered with paste, heat radiation grease or the like.

  The LED chips 12, 14, and 16 mounted on the light-emitting element mounting substrate 10a are provided so that the LED chips 12, 14, and 16 are positioned at the outermost edge portion of the opening 20 of the reflector frame 18 to be described later. ing.

  Next, as shown in FIGS. 3A and 3B, a reflector frame 18 having an opening 20 so as to surround the LED chips 12, 14, 16 mounted on the light emitting element mounting substrate 10a. Is disposed on the light emitting element mounting substrate 10a.

  The size of the opening 20 is slightly larger than the formation area of the mounted LED chips 12, 14, and 16, and the sectional shape of the opening 20 is as shown in FIG. 3B. , 14 and 16 are inclined surfaces that are inclined so that the opening diameter becomes smaller. In addition, it is preferable that inclination-angle (theta) 1 of an inclined surface shall be 90 degree | times or more.

  When the reflector frame 18 is disposed on the light emitting element mounting substrate 10a, an adhesive or an adhesive sheet represented by an epoxy resin, a urethane acrylate resin, or a cyanoacrylate resin can be used.

Further, if the opening 20 of the reflector frame 18 is filled with a sealing resin 19 such as a silicone resin, a bonding wire (not shown) or the like can be protected.
Further, the material of the reflector frame 18 is not particularly limited, but a thermoplastic resin such as polyolefin or polystyrene, a thermosetting resin such as epoxy resin or phenol resin, or an engineering plastic such as polyamide or polycarbonate is desired. It can be formed by forming into the shape of the reflector frame 18 and coating the surface with a metal film having a good reflectivity such as aluminum or silver, or painting with a white paint.

  It is also possible to mold a resin material whose material itself is adjusted to white (for example, Kuraray Co., Ltd .; white type (Genesta: registered trademark)), etc. What processed metal materials, such as stainless steel, is also applicable. In this case, the total reflectance of the reflector frame 18 is preferably 80% or more, more preferably 90% or more in the visible light region.

Next, as shown in FIGS. 4A and 4B, a lens 22 a having a conical recess 24 on the upper surface is disposed on the upper part of the reflector frame 18.
As the material of the lens 22a, a highly transparent resin such as an acrylic resin, a polycarbonate resin, a polyester resin, a liquid crystal polymer resin, or a silicone resin can be used.

  Further, the angle θ2 of the recess 24 provided in the lens 22a is the distance from the LED chip 12, 14, 16 of the recess 24, the diameter of the lens 22a, the position of the LED chips 12, 14, 16 from the center of the lens 22a, etc. It will change depending on.

  Specifically, when the distance between the concave portion 24 and the LED chips 12, 14, 16 is short, when the distance from the center of the lens 22a is far from the LED chips 12, 14, 16, or when the diameter of the lens 22a is large, The angle θ2 is preferably 60 to 150 degrees, more preferably 90 to 120 degrees.

If the angle θ2 of the recess 24 is thus provided, the light emitted from the mounted LED chips 12, 14, 16 can be spread efficiently and uniformly in the lateral direction.
Moreover, you may provide a reflection part (not shown) in the recessed part 24 provided in the lens 22a.

  By controlling the degree of reflection of the reflecting portion, it becomes possible to control the light emitted from the mounted LED chips 12, 14, 16 in the lateral direction and the upper direction. For example, the reflectance is 20% to 95%, and a white paint can be formed by application or printing to form a reflective part, or a metallic gloss layer deposited with aluminum can be used as the reflective part.

  As described above, if the reflecting portion is provided in the concave portion 24 provided in the lens 22a, the light incident from the LED chips 12, 14, and 16 has a deep incident angle and is forced to be transmitted laterally. Can be reflected in the direction.

  The method for attaching the lens 22a to the reflector frame 18 is not particularly limited. For example, an adhesive or an adhesive sheet represented by an epoxy resin, a urethane acrylate resin, or a cyanoacrylate resin is used. A method of bonding, a method of providing the fitting convex portion 23 on the lens 22a, and fitting and fixing the fitting convex portion 23 to the opening 20 of the reflector frame 18, or a method of using these together is used. it can.

Further, the distance L from the center of the recess 24 of the lens 22a to each LED chip 12, 14, 16 varies depending on the size of the light emitting element mounting package 34a, but is 20% to 95% of the radial distance of the lens 22a. A distance is preferred.

  By mounting the LED chips 12, 14, and 16 at such positions, the light emitted from the LED chips 12, 14, and 16 is mixed, and the light is uniformly spread in the lateral direction to obtain brightness and color. The light emitting element mounting package 34a capable of emitting white light without unevenness is obtained.

  Further, if the light-emitting element mounting package 34a thus obtained is used for a surface light source device (backlight) used for a liquid crystal display or the like, a large surface light source device can be easily produced at a low manufacturing cost. Furthermore, by spreading the light uniformly in the lateral direction, it is possible to emit white light with no unevenness in luminance and chromaticity and obtain a clear image.

  In addition, the LED chips 12, 14, and 16 are intentionally provided at positions away from the center O of the concave portion 24 of the lens 22a, that is, near the outermost edge of the opening 20 of the reflector frame 18, so Brightness and chromaticity are achieved by facilitating the reflection of light of each color, increasing the color mixture in the reflector frame 18 and the lens 22a, and uniformly spreading the light emitted from the LED chips 12, 14, and 16 in the lateral direction. Can emit white light with no unevenness.

5 to 7 schematically show the manufacturing process of the light emitting device mounting package according to the second embodiment of the present invention.
The manufacturing process of the light emitting device mounting package according to the second embodiment shown in FIGS. 5 to 7 has the same configuration as that of the above embodiment shown in FIGS. Reference numerals are assigned and detailed description thereof is omitted.

  A light emitting element mounting substrate 10b mounted with a plurality of LED chips 12, 14, and 16 having different emission colors used in the manufacturing process of the light emitting element mounting package according to the second embodiment shown in FIGS. The light emitting element mounting portion 26 is provided in three directions from the center O on the element mounting substrate 10b, and each of the light emitting element mounting portions 26 has a mounting portion where three LED chips can be mounted.

  As shown in FIGS. 5A and 5B, the light emitting element mounting portions 26 are provided in three directions from the center O on the light emitting element mounting substrate 10b. A light emitting element mounting substrate 10b having a configuration capable of mounting an LED chip is prepared.

  At this time, the LED chips 12, 14, and 16 mounted on the light emitting element mounting substrate 10b are arranged near the outermost edge of the opening 20 of the reflector frame 18 that surrounds the LED chips 12, 14, and 16 in the next process. The position of the light emitting element mounting portion 26 where the chips 12, 14, 16 are arranged is selected, and the LED chips 12, 14, 16 are mounted. In the present embodiment, the LED chips 12, 14, and 16 are mounted on the middle mounting portion 30 of the light emitting element mounting portion 26, respectively.

  Further, as shown in FIGS. 6A and 6B, the reflector frame 18 is mounted on the light emitting element so as to surround the LED chips 12, 14, and 16 mounted on the light emitting element mounting substrate 10b. It arrange | positions on the board | substrate 10b.

  When the reflector frame 18 is disposed on the light emitting element mounting substrate 10b, an adhesive or an adhesive sheet represented by an epoxy resin, a urethane acrylate resin, or a cyanoacrylate resin is used as in the first embodiment. it can.

Moreover, the material used in the first embodiment can be similarly used for the material of the reflector frame 18.
Further, a sealing resin 19 such as a silicone resin is filled in the opening 20 of the reflector frame 18.

  Then, as shown in FIGS. 7A and 7B, a lens 22a having a conical recess 24 on the upper surface is disposed on the upper part of the reflector frame 18 as in the first embodiment. Thus, the light emitting element mounting package 34b to which the lens 22a is attached can be obtained.

  As described above, the light emitting element mounting portion 26 is provided in three directions from the center O on the light emitting element mounting substrate 10b in advance, and each of the light emitting element mounting portions 26 can be mounted with three LED chips. The mounting work of 12, 14, 16 is extremely easy.

  Further, the diameter of the opening 20 of the reflector frame 18 is determined according to the LED chip mounting positions 28, 30, and 32 in the light emitting element mounting portion 26, or conversely, according to the diameter of the opening 20 of the reflector frame 18. Thus, the LED chip mounting positions 28, 30, and 32 in the light emitting element mounting portion 26 can be determined.

  Also, if these are standardized according to several sizes, the assembly workability is extremely easy, and even if the LED chips have different sizes and heat generation amounts, the same light emitting element mounting package 34b can be obtained. Since it can be mounted, it is not necessary to design and manufacture various light emitting element mounting substrates 10b and light emitting element mounting packages 34b, and cost reduction can be achieved.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these.
For example, in the light emitting element mounting package, the surface light source device, and the display device of the present invention, the LED chip 12 that emits red light, the LED chip 14 that emits green light, and the LED chip 16 that emits blue light are used as the light emitting elements. As shown in FIG. 8, it is also possible to use LED chips of four or more colors.

In the case of using four colors, it is preferable to use, for example, an LED chip 32 that emits yellow-green light having a color rendering effect as the fourth color.
In addition, the number of LED chips corresponding to the opening 20 provided in the reflector frame 18 does not necessarily have to be uniform. For example, two LED chips that emit red light, one LED chip that emits green light, one LED chip that emits blue light, and a total of four may correspond to one opening 20. The combination is not limited.

Furthermore, the light emitting element is not limited to the LED chip, and various changes and function additions can be made without departing from the object of the present invention.
[Example]
First, a light emitting element mounting substrate 10a, a reflector frame 18, a lens 22a (reflecting part: present / absent), and LED chips 12, 14, 16 (light emitting colors: red, green, blue) shown below were prepared.

Light emitting element mounting substrate 10a:
A white insulating layer having a thickness of 35 mm and a white insulating layer having a thickness of 40 μm is formed on a copper base substrate having a thickness of 80 μm, and a copper wiring pattern is further formed.

Reflector frame 18:
Opening 20 with an upper diameter of 34 mm and a lower diameter of 24 mm penetrating in the thickness direction is provided with a white 35 mm square and a thickness of 3 mm. Genesta: registered trademark)).

Lens 22a (with reflection part):
The diameter is 34 mm, the height is 18 mm, the concave portion 24 having an angle θ2 of 120 degrees is provided on the top of the lens 22a, and the material is made of ZEONEX (manufactured by Nippon Zeon Co., Ltd.). In the concave portion 24 of the lens 22a, a reflective portion is formed by painting with acrylic lacquer spray white model 01 (Nippe Home Products Co., Ltd.).

Lens 22a (without reflection):
The diameter is 34 mm, the height is 18 mm, the concave portion 24 having an angle θ2 of 120 degrees is provided on the top of the lens 22a, and the material is made of ZEONEX (manufactured by Nippon Zeon Co., Ltd.).

LED chip 12 emitting red light:
The dimensions are 1mm square and 0.5W class.
LED chip 14 emitting green light:
Dimensions are 1mm square and 1W class.

LED chip 16 emitting blue light:
Dimensions are 1mm square and 1W class.

  On the light emitting element mounting substrate 10a, the LED chip 12 that emits red light, the LED chip 14 that emits green light, and the LED chip 16 that emits blue light are respectively located at a position of 10 mm from the center of the light emitting element mounting substrate 10a. It was mounted at a predetermined interval (see FIG. 2 (a) and FIG. 2 (b)).

  Furthermore, the reflector frame 18 was disposed on the light emitting element mounting substrate 10a on which the LED chips 12, 14, and 16 were mounted via an adhesive sheet (see FIGS. 3A and 3B).

Next, a lens 22a (without a reflection portion) was installed on the reflector frame 18 via an adhesive sheet (see FIGS. 4A and 4B).
In this way, a light emitting element mounting package 34a1 was produced.

Further, the light-emitting element mounting package 34a1 was placed and fixed in an aluminum casing (not shown) having a bottom surface length of 50 mm × width of 50 mm × height of 50 mm and an open top surface.
Next, a white reflective film Lumirror (registered trademark) 60L (manufactured by Toray) was bonded to the inner surface of the casing other than the opening to form a reflective portion (not shown).

  Further, a 1 mm thick diffusion sheet (not shown) made of polycarbonate (trade name PC9391-50HL (manufactured by Teijin Kasei)) is fixed to the front surface of the opening of the aluminum casing, and a surface light source device (not shown). It was created.

  In this surface light source device, a current of 220 mA was applied to the LED chip 12 emitting red light, a current value of 280 mA was applied to the LED chip 14 emitting green light, and a current of 110 mA was applied to the LED chip 16 emitting blue light.

And the whole average brightness | luminance and chromaticity coordinate on the diffusion sheet of a surface light source device were measured with the chromaticity meter (brand name CS1000 (made by Konica Minolta)).
Further, on the diffusion sheet, when the luminance and chromaticity coordinates of the 10 mm diameter region are measured at intervals of 2 mm diagonally from the point corresponding to the normal of the lens center position, the luminance variation and chromaticity variation of each point are as follows: I asked for it.

Variation in luminance at each point: (maximum luminance-minimum luminance) / average luminance x 100%
Variation in chromaticity: difference between maximum value and minimum value of chromaticity coordinates X and Y Table 1 shows the values thus obtained.

  The LED chip 12 that emits red light, the LED chip 14 that emits green light, and the LED chip 16 that emits blue light are predetermined on the light emitting element mounting substrate 10a at a position 5 mm from the center of the light emitting element mounting substrate 10a. A surface light source device was created in the same manner as in Example 1 except that the light emitting element mounting package 34a2 was created by mounting at intervals, and the overall average luminance, luminance variation, overall average chromaticity, and chromaticity variation were obtained. It was.

  The values thus obtained are shown in Table 1.

  A surface light source device was created in the same manner as in Example 1 except that the light emitting element mounting package 34a3 was created by disposing the lens 22a having a reflecting portion on the reflector frame 18, and the overall average brightness, brightness variation, Overall average chromaticity and chromaticity variation were determined.

  The values thus obtained are shown in Table 2.

  A surface light source device was created in the same manner as in Example 2 except that the light emitting element mounting package 34a4 was created by disposing the lens 22a having a reflecting portion on the reflector frame 18, and the overall average brightness, brightness variation, Overall average chromaticity and chromaticity variation were determined.

The values thus obtained are shown in Table 2.
[Comparative Example 1]
The LED chip 12 that emits red light, the LED chip 14 that emits green light, and the LED chip 16 that emits blue light are predetermined on the light emitting element mounting substrate 10a at positions of 2 mm from the center of the light emitting element mounting substrate 10a. A surface light source device was created in the same manner as in Example 1 except that the light-emitting element mounting package 34a5 was created by mounting at intervals, and the overall average luminance, luminance variation, overall average chromaticity, and chromaticity variation were obtained. It was.

The values thus obtained are shown in Table 1.
[Comparative Example 2]
The LED chip 12 that emits red light, the LED chip 14 that emits green light, and the LED chip 16 that emits blue light are predetermined on the light emitting element mounting substrate 10a at positions of 2 mm from the center of the light emitting element mounting substrate 10a. A surface light source device was prepared in the same manner as in Comparative Example 1 except that the light emitting element mounting package 34a6 was prepared by arranging the lens 22a having a reflection portion on the reflector frame 18 and mounting the lens 22a on the reflector frame 18. The overall average brightness, brightness variation, overall average chromaticity, and chromaticity variation were determined.

  The values thus obtained are shown in Table 2.

As shown in Table 1, when Examples 1 and 2 were compared with Comparative Example 1, it was confirmed that the variations in luminance in Examples 1 and 2 were eliminated compared to Comparative Example 1. It was.
Furthermore, it was confirmed that the variation in luminance was eliminated as the position of each LED chip 12, 14, 16 was moved away from the center of the light emitting element mounting substrate 10a toward the outer edge of the opening 20 of the reflector frame 18.

As shown in Table 2, when Examples 3 and 4 were compared with Comparative Example 2, it was confirmed that the variations in luminance in Examples 3 and 4 were eliminated compared to Comparative Example 2. It was.
Furthermore, it was confirmed that the variation in luminance was eliminated as the position of each LED chip 12, 14, 16 was moved away from the center of the light emitting element mounting substrate 10a toward the outer edge of the opening 20 of the reflector frame 18.

Furthermore, as shown in Table 1, when the concave portion 24 of the lens 22a does not have a reflective portion,
As shown in Table 2, when compared with the case where the concave portion 24 of the lens 22a has a reflective portion, when the reflective portion is not provided, the overall average luminance is slightly higher and the luminance variation is slightly larger. Was confirmed.

In addition, it was confirmed that when the reflective portion was provided, the overall average luminance was slightly low and the luminance variation was slightly small.
As described above, according to the example and the comparative example, in the light emitting element mounting substrate 10a of the surface light source device, the positions of the LED chips 12, 14, 16 are changed from the center of the light emitting element mounting substrate 10a to the opening 20 of the reflector frame 18. It was confirmed that the variation in luminance was resolved as the distance from the outer edge was increased.

  Further, it was confirmed that when the concave portion 24 of the lens 22a has a reflective portion, the luminance variation is small, and when the concave portion 24 of the lens 22a does not have a reflective portion, the overall average luminance is increased.

FIG. 1 is a diagram illustrating an overall configuration of an example of a liquid crystal display device to which the exemplary embodiment is applied. FIG. 2 is a schematic diagram illustrating a state in which LED chips of three colors are attached to a light emitting element mounting substrate used in the light emitting element mounting package according to the first embodiment of the present invention, and FIG. FIG. 2B is a cross-sectional view taken along line XX in FIG. FIG. 3 is a schematic view showing a state in which a reflector frame is disposed on a light emitting element mounting substrate used in the light emitting element mounting package according to the first embodiment of the present invention, and FIG. FIG. 3 and FIG. 3B are cross-sectional views taken along line XX in FIG. FIG. 4 shows a state in which a reflector frame is disposed on a light emitting element mounting substrate used in the light emitting element mounting package according to the first embodiment of the present invention, and a lens is disposed above the reflector frame. 4A is a top view, and FIG. 4B is a cross-sectional view taken along line XX in FIG. 4A. FIG. 5 is a schematic view showing a state in which LED chips of three colors are attached to a light emitting element mounting substrate used in the light emitting element mounting package according to the second embodiment of the present invention, and FIG. FIG. 5B is a cross-sectional view taken along line XX of FIG. FIG. 6 is a schematic view showing a state in which a reflector frame is disposed on a light emitting element mounting substrate used in a light emitting element mounting package according to a second embodiment of the present invention, and FIG. FIG. 6 and FIG. 6B are cross-sectional views taken along line XX of FIG. FIG. 7 shows a state in which a reflector frame is disposed on a light emitting element mounting substrate used in a light emitting element mounting package according to the second embodiment of the present invention, and a lens is disposed above the reflector frame. 7A is a top view, and FIG. 7B is a cross-sectional view taken along line XX in FIG. 7A. FIG. 8 is a schematic view of a light emitting device employed in still another embodiment of the present invention. FIG. 9 is a schematic cross-sectional view showing a conventional edge light type backlight light source. FIG. 10 is a schematic cross-sectional view showing a conventional direct type backlight light source. 11A and 11B are schematic views of a conventional three-in-one package, in which FIG. 11A is a plan view, and FIG. 11B is an assembly cross-sectional view taken along line XX in FIG. FIG. 12 is a schematic view of an LED package having a conventional lens.

Explanation of symbols

10a .. Light emitting element mounting substrate 10b .. Light emitting element mounting substrate 12... LED chip that emits red light 14... LED chip that emits green light 16... LED chip that emits blue light 18. Reflector frame 19... Sealing resin 20... Opening 22 a .. lens 22 b .. lens 23... Fitting convex 24 .. recessed 26. Position 30... Mounting portion 32... LED chip that emits yellow-green light 34 a .. Light emitting element mounting package 34 a 1. Light emitting element mounting package 34 a 2. Light emitting element mounting package 34 a 3. Light emitting element mounting package 34 a 4.・ Light emitting device mounting package 34a6 ・ Light emitting device mounting package 34b ・ ・ Light emitting device mounting package L ・ ・ ・ Distance O ··· center θ1 ·· angle θ2 ·· angle 50 ... backlight device (backlight)
51 ... Backlight frame (housing)
52... LED board (light emitting element mounting board)
53 ... Diffusing member (plate, sheet)
54 ... Prism sheet 55 ... Prism sheet 60 ... Liquid crystal display module 61 ... Liquid crystal panel 62 ... Polarizing plate (polarizing filter)
63 ... Polarizing plate (polarizing filter)
DESCRIPTION OF SYMBOLS 100 ... Backlight light source 102 ... Case 104 ... Cold cathode tube 106 ... Light guide plate 108 ... Diffusion sheet 110 ... Liquid crystal panel 112 ... Liquid crystal display device 114 ... side Part 116 ... Reflective layer 200 ... Backlight light source 202 ... Housing 204 ... Bottom 206 ... LED lamp 208 ... Diffusion sheet 210 ... Prism sheet 212 ... Side 214 .. reflective layer 300... Three-in-one package 302... LED chip 304 emitting red color... LED chip 306 emitting green color... LED chip 308 emitting blue color. ..Light emitting element mounting substrate 312... Opening 314... Sealing resin 400... LED package 402... LED chip 404. 06 ... funnel-shaped portion 408 ... serration

Claims (8)

A plurality of types of light emitting elements with different emission colors are mounted on a light emitting element mounting substrate,
A reflector frame having an opening is provided on the light emitting element so as to surround the light emitting element.
Furthermore, a light emitting element mounting package in which a lens having a concave portion on the upper surface is disposed on the upper portion of the opening of the reflector frame ,
The light emitting element is
A light emitting element mounting package, wherein the light emitting element mounting package is located at an outermost edge of the opening of the reflector frame and is mounted at a position between 20% and 95% of a radial distance from the center of the concave portion of the lens. . The light emitting element is
The light emitting element mounting package according to claim 1 , wherein the light emitting element mounting package is disposed on the light emitting element mounting substrate at equal intervals. The light emitting element, the light-emitting element mounting package according to claim 1 or 2, characterized in that a light emitting diode (LED). 4. The light emitting device mounting package according to claim 3 , wherein the light emitting diode (LED) is a light emitting diode (LED) chip. The recess of the lens, the light-emitting element mounting package according to any one of claims 1 to 4, characterized in that the reflecting portion is disposed. The surface light source device, wherein a light-emitting element mounting package is disposed of according to any one of claims 1 to 5. The surface light source device according to claim 6 , wherein the surface light source device is a backlight for a display device. A display device comprising a liquid crystal panel disposed on an upper surface of the surface light source device according to claim 6 .

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