JP2016162932A - Led light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED light source device which allows for efficient lighting by preventing the light, impinging on the emission surface at an angle larger than the total reflection angle, from reflecting totally and returning back to the inside.SOLUTION: In an LED light source device 10 including a long substrate 2, a plurality of LEDs 1 mounted in a row on the substrate 2, and a translucent resin 3 sealing the LED1 integrally, the emission surface 3a of the translucent resin 3 is flat at the upper part of the LED1, and includes an irregular shape 3c at an upper part between adjoining LEDs 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an LED light source device in which a plurality of LEDs are mounted in a row on a substrate.

  In recent years, since LEDs are semiconductor elements, they have long life and excellent driving characteristics, and are small, have high luminous efficiency, and have bright emission colors, so they are widely used for backlights and lighting of color display devices. It has come to be.

  In particular, in recent years, a planar light source having a light guide plate of a type that emits light incident from the side surface from the upper surface is often used as a backlight for notebook computers and liquid crystal televisions. A line-shaped LED light source device that supplies incident light has been proposed. (For example, Patent Document 1)

(Description of the configuration of the LED light source device in the prior art)
The configuration of the LED light source device in the prior art described in Patent Document 1 will be described below with reference to FIG. It should be noted that the drawings are partially simplified and the reference numerals are also changed in accordance with the present application without departing from the spirit of the invention. FIG. 11 is a perspective view of a conventional LED light source device 100.

  As shown in FIG. 11, the LED light source device 100 includes a plurality of LEDs 101 mounted in a row on a long substrate 102 and a translucent resin 103 that integrally seals the plurality of LEDs 101. Yes. In the LED light source device 100, the translucent resin 103 is made of a translucent resin such as a transparent resin or a fluorescent resin, and is a semi-cylindrical section having a semicircular cross section. The semi-cylindrical curved surface serves as an emission surface, and emits emitted light upward. The LED light source device 100 forms a line light source by simultaneously lighting a plurality of LEDs 101 mounted in a row on a substrate 102.

Japanese Patent Laid-Open No. 2002-299697 (FIG. 1)

(Description of operation of LED light source device in prior art)
FIG. 12 is a cross-sectional view taken along the line AA of the LED light source device 100 shown in FIG. 11 and shows the light emission characteristics of the two LEDs 101a and 101b.
When the LEDs 101a and 101b emit light by supplying current to the LEDs 101a and 101b, the light emitted upward from the LEDs 101a and 101b is incident on the emission surface at an angle smaller than the total reflection angle (critical angle). Refracted based on the difference in refractive index between the conductive resin 103 and the air layer, and is emitted upward to become effective illumination light Ps.

However, the light incident on the emission surface at an angle larger than the total reflection angle is totally reflected on the surface (emission surface) of the translucent resin 103 and returned to the inside of the translucent resin 103 as reflected light Ph.
As described above, the LED light source device 100 includes light that is returned to the inside of the translucent resin 103 as the reflected light Ph in the light emission of the LED 101, so that the emission efficiency as a line light source is reduced, and the illumination is efficient. There is a problem of not becoming.

  Therefore, the present invention solves the above problems and provides an LED light source device that can perform efficient illumination so that light incident on the exit surface at an angle larger than the total reflection angle is not totally reflected and returned to the inside. The purpose is to provide.

  In order to achieve the above object, the LED light source device according to the present invention includes a long substrate, a plurality of LEDs mounted in a row on the substrate, and a translucent resin that integrally seals the LEDs. The upper part of the LED on the light emitting surface of the light transmitting resin is flat, and the upper part between adjacent LEDs on the light emitting surface of the light transmitting resin is provided with an uneven shape. It is characterized by.

  According to the said structure, the output surface of translucent resin is flat in the upper part of LED. The light incident on the flat part is emitted to the outside while being refracted. On the other hand, an uneven shape is provided on the surface of the translucent resin in the upper part between adjacent LEDs. The light incident on the concavo-convex shape is emitted outside without being totally reflected because the incident angle becomes small due to the concavo-convex shape. As described above, an LED light source device with good emission efficiency can be provided.

  The translucent resin may be formed in a rectangular parallelepiped shape, and the uneven shape may be formed on an upper surface of the rectangular parallelepiped shape.

  According to the above configuration, in addition to the above-described operation, when light is incident on the side surface of the flat light guide plate, the incorporation into the light guide plate is improved.

  The translucent resin is preferably formed in a semi-cylindrical shape, and the uneven shape is formed on the semi-cylindrical curved surface.

  According to the above configuration, since the emitted light is concentrated above the substrate due to the semi-cylindrical lens effect in addition to the above-described operation, the incident efficiency can be improved when the light is incident on the side surface of the flat light guide plate.

  The uneven shape may be a prism having a triangular cross section.

  The uneven shape may be a prism having a semicircular cross section.

  The uneven shape may be a conical or pyramidal protrusion.

  The uneven shape is preferably a diffusion surface.

  The plurality of LEDs may be red LEDs, green LEDs, and blue LEDs, and the red LEDs, the green LEDs, and the blue LEDs may be arranged on the long substrate so as to repeat this combination.

  According to the said structure, since transparent resin can be used as translucent resin for producing a white light source, it becomes a bright LED light source device.

  As described above, in the LED light source device of the present invention, the light emitted from the LED toward the upper part of the LED is incident on the flat part of the light-emitting resin exit surface formed on the upper part of the LED, and is refracted as it is. In addition, the light traveling toward the upper part between the adjacent LEDs is emitted to the outside without being totally reflected by the uneven shape of the light-emitting resin exit surface provided at the upper part between the adjacent LEDs. The emission efficiency can be increased.

It is a perspective view of the LED light source device in 1st Embodiment of this invention. It is AA sectional drawing of the LED light source device shown in FIG. It is a partial expanded sectional view of the uneven | corrugated shaped part 3c shown in FIG. It is a perspective view of the LED light source device in 2nd Embodiment of this invention. It is AA sectional drawing of the LED light source device shown in FIG. It is a perspective view of the LED light source device in 3rd Embodiment of this invention. It is AA sectional drawing of the LED light source device shown in FIG. It is a perspective view of the LED light source device in 4th Embodiment of this invention. It is AA sectional drawing of the LED light source device shown in FIG. It is a perspective view of the display apparatus using the LED light source device of this invention. It is a perspective view of the LED light source device in a prior art example. It is AA sectional drawing of the LED light source device shown in FIG.

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

(First embodiment)
The LED light source device 10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view of the LED light source device 10, FIG. 2 is an AA cross-sectional view of the LED light source device 10 shown in FIG. 1, and FIG. 3 is a partially enlarged cross-sectional view of the uneven portion 3b shown in FIG.

  As shown in FIG. 1, the LED light source device 10 includes a long substrate 2, a plurality of LEDs 1 mounted in a row on the substrate 2, and a translucent resin 3 that integrally seals the plurality of LEDs 1. It has. In this LED light source device 10, the translucent resin 3 is a rectangular parallelepiped made of a translucent resin such as a transparent resin or a fluorescent resin, and the upper surface 3a of the rectangular parallelepiped is emitted from the rectangular parallelepiped. The emitted light is emitted upward as a surface.

A flat portion and a concavo-convex shape portion are partially formed on the emission surface 3 a constituting the entire upper surface of the translucent resin 3. That is, the upper portion of the LED 1 is a flat portion 3b, and the region between the LEDs 1 is an uneven portion 3c. The concave and convex portion 3c is formed with a plurality of prisms having a triangular cross section and extending in the lateral direction.
In FIG. 1, a state in which each LED 1 mounted on the substrate 2 is aligned with the flat portion 3 b of the emission surface 3 a in the translucent tree 3 is illustrated by a y-axis indicated by a dotted line. Further, the positional relationship between the LED 1 and the flat portion is the same in the following embodiments.

(Description of the operation of the LED light source device in the first embodiment)
FIG. 2 is a cross-sectional view taken along line AA of the LED light source device 10 shown in FIG. 1, and shows the light emission characteristics of the two LEDs 1a and 1b.
When current is supplied to the LEDs 1a and 1b, the LEDs 1a and 1b emit light. A part of the light emitted from the LEDs 1a and 1b enters the flat portion 3b at an angle smaller than the total reflection angle (critical angle) on the emission surface 3a. The light incident on the flat portion 3b is refracted based on the difference in refractive index between the translucent resin 3 and the air layer, and is emitted upward as emitted light to become effective illumination light Ps.

  The other part of the light emitted from the LEDs 1a and 1b is incident on the concavo-convex shape portion 3c of the emission surface 3a at an angle larger than the total reflection angle (critical angle). In the concavo-convex shape portion 3c, a plurality of prisms having a triangular cross section of the translucent resin 3 are formed. Since the light incident on the concavo-convex shape portion 3c has a plurality of prisms, the light is not totally reflected but is emitted upward as outgoing light to become effective illumination light Ps.

FIG. 3 is a partially enlarged cross-sectional view of the uneven portion 3c shown in FIG. The concavo-convex shape 4 arranged in the concavo-convex shape portion 3c is composed of a prism having a triangular cross section. A light ray P1a from the LED 1a enters the right slope 4a of the concavo-convex shape 4 at a small angle, refracts at the right slope 4a, and then exits to the outside. Similarly, the light beam P1b from the LED 1b enters the left slope 4b of the concavo-convex shape 4 at a small angle, is refracted by the left slope 4b, and then exits to the outside. Any of the light rays P1a and P1b is refracted by the inclined surfaces 4a and 4b and is directed upward to enhance the illumination effect (light ray Ps).
In the LED light source device 10, since the translucent resin 3 is a rectangular parallelepiped, the thickness of the translucent resin 3 (the length in the short direction of the substrate 2) is made equal to the thickness of the light guide plate. In addition to the above action, when light is incident on the side surface of the flat light guide plate, the incorporation into the light guide plate is improved.

In order to use the LED light source device 10 shown in FIG. 1 as a white light source, a plurality of LEDs 1 mounted in a row on a substrate are replaced with a red LED (R-LED), a green LED (G-LED), and a blue LED (B- LED). That is, R-LED, G-LED, and B-LED are arranged from the end on a long substrate 2, and this combination is repeated (for example, in FIG. 2, LED 1a is R-LED and LED 1b is G- LED.) Since the transparent resin 3 for sealing these LEDs 1 can use a transparent resin, an LED light source device with good luminous efficiency can be obtained. Moreover, a pseudo white light source can be obtained by using all the LEDs 1 as B-LEDs and using a fluorescent resin in which a phosphor such as YAG is kneaded as the translucent resin 3. In this case, a cost-effective LED light source device can be obtained.
In the following embodiments, any configuration is naturally applicable although not specifically described.

(Second Embodiment)
The LED light source device 20 according to the second embodiment of the present invention will be described with reference to FIGS. 4 is a perspective view of the LED light source device 20, and FIG. 5 is a cross-sectional view taken along the line AA of the LED light source device 20 shown in FIG.
The LED light source device 20 has the same basic configuration as that of the LED light source device 10 shown in FIG. 1, and the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

  The LED light source device 20 is different from the LED light source device 10 in that the uneven shape 24 is a semicircular lenticular lens. The concave / convex shape 24 is formed in the concave / convex shape portion 23 c of the emission surface 23 a of the translucent resin 23. The LED light source device 20 directs light to be emitted from the concavo-convex shape portion 23c upward while preventing total reflection of light emitted from the LED 1 by the lenticular lens.

(Third embodiment)
An LED light source device 30 according to a third embodiment of the present invention will be described with reference to FIGS. 6 is a perspective view of the LED light source device 30, and FIG. 7 is a cross-sectional view taken along the line AA of the LED light source device 30 shown in FIG.
The LED light source device 30 also has the same basic configuration as the LED light source device 10 shown in FIG. 1, and the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

  The LED light source device 30 is different from the LED light source device 10 in that the concavo-convex shape 34 has no prism and has a conical protrusion. The concave / convex shape 34 is formed in the concave / convex shape portion 33 c of the emission surface 33 a of the translucent resin 33. The LED light source device 30 directs light to be emitted from the concavo-convex shape portion 33c upward while preventing total reflection of light emitted from the LED 1 by the conical protrusion. Note that the concave and convex portion 33c may be provided with a pyramidal projection instead of a conical projection.

(Fourth embodiment)
The LED light source device 40 according to the fourth embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a perspective view of the LED light source device 40, and FIG. 9 is a cross-sectional view taken along the line AA of the LED light source device 40 shown in FIG.
The LED light source device 40 according to the fourth embodiment also has the same basic configuration as that of the LED light source device 10 shown in FIG. 1, and the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

The LED light source device 40 is different from the LED light source device 10 in that the shape of the translucent resin 43 is not a rectangular parallelepiped but a semi-cylindrical shape, and the entire curved surface of the semi-cylindrical shape is an emission surface 43a. . In the LED light source device 40, the surface of the transparent resin 43 has a flat portion at the top of the LED 1 and an uneven portion 43 c between the LED 1 and the adjacent LED 1. The flat part 43b and the uneven | corrugated shaped part 43c are formed in strip | belt shape so that the circumference may be followed.
In the LED light source device 40, the uneven shape 44 of the uneven portion 43c formed on the exit surface 43a is not a prism but a diffusion surface 44a. The LED light source device 40 emits light to the outside from the concave and convex portion 33c while preventing total reflection of light emitted from the LED 1 by the diffusion surface 44a.

In the LED light source device 40, since the translucent resin 43 is formed in a semi-cylindrical shape, the light directed obliquely upward in the lateral direction with respect to the substrate is condensed upward by the lens effect. As a result, when light is incident on the side surface of the flat light guide plate, the incidence efficiency can be increased.
In this embodiment, the concavo-convex shape portion 44 is the diffusion surface 44a. However, like the concavo-convex shape portion (3c, etc.) shown in the first to third embodiments, the prism has a triangular cross section and a cross section. However, the same effect can be obtained even with a semicircular lenticular lens, a conical or pyramidal protrusion.

  Next, a display device 50 using the LED light source device 10 of the present invention will be described with reference to FIG. FIG. 10 is a perspective view of the display device 50. In the display device 50, the light guide member 70 (light guide plate) is disposed on the lower surface of the display element 60 such as a liquid crystal cell, and the LED light source device 10 illustrated in FIG. 1 is disposed on one side surface of the light guide member 70. Yes. When the LED light source device 10 emits light, light is emitted from the LED light source device 10 in the direction indicated by the arrow, and the light enters the light guide member 70. The light guide member 70 illuminates the display element 60 from below by directing incident light upward.

  The LED light source device of the present invention can be applied not only to the white light source shown in each embodiment but also to various color light sources.

1, 1a, 1b, 101 LED
2,102 Substrate 3, 23, 33, 43, 103 Translucent resin 3a, 23a, 33a, 43a Emitting surface 3b, 23b, 33b, 43b Flat part 3c, 23c, 33c, 43c Concavity and convexity part 4, 24, 34 44 Uneven shape 10, 20, 30, 40, 100 LED light source device 50 display device 60 display element 70 light guide member

Claims (8)

  In an LED light source device comprising a long substrate, a plurality of LEDs mounted in a row on the substrate, and a translucent resin that integrally seals the LEDs, emission of the translucent resin The LED light source device according to claim 1, wherein an upper portion of the LED on the surface is flat, and an upper portion between adjacent LEDs on the light-emitting resin emitting surface is provided with an uneven shape.   The LED light source device according to claim 1, wherein the translucent resin is formed in a rectangular parallelepiped shape, and the uneven shape is formed on an upper surface of the rectangular parallelepiped shape.   The LED light source device according to claim 1, wherein the translucent resin is formed in a semi-cylindrical shape, and the uneven shape is formed on the semi-cylindrical curved surface.   The LED light source device according to claim 1, wherein the uneven shape is a prism having a triangular cross section.   The LED light source device according to claim 1, wherein the uneven shape is a prism having a semicircular cross section.   The LED light source device according to claim 1, wherein the uneven shape is a conical or pyramidal protrusion.   The LED light source device according to claim 1, wherein the uneven shape is a diffusion surface. The plurality of LEDs include a red LED, a green LED, and a blue LED, and the red LED, the green LED, and the blue LED are arranged on the long substrate so as to repeat this combination. Item 8. The LED light source device according to any one of Items 1 to 7.

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