JPH0220078A - Linear led light source - Google Patents

Abstract

PURPOSE:To improve the projection efficiency to a plane to which light is projected and to prevent deterioration of a light emitting element by reflecting the light emitted from the light emitting element so as to form the convergent light, converting the light into the linear light through lightguides, and radiating the light to the outside. CONSTITUTION:A light emitting element 1 is mounted on one lead frame 2 and electrically connected to another lead frame 3 with a piece of wire 4. The tip parts of the light emitting element 1 and the lead frames 2 and 3 are molded with a light transmitting materiel 5. The surface of a reflecting surface 5a of the light transmitting material 5 faces the light emitting surface of the light emitting element 1. Said surface is formed as an elliptical surface shape. The surface is machined as a mirror surface by plating, metal evaporation and the like. Each linear lightguide 6a in a lightguide part 6 is formed as follows: the lightguides 6a are bundled in a bundle shape at an input port 6b where the light is inputted; and the lightguides 6a are arranged in the linear shape at emitting port 6c through which the light is emitted to the outside. The light emitting element 1 is arranged at one focal point of the reflecting surface 5a which is formed in an elliptical surface shape. The input port 6b of the lightguide part 6 is arranged in the vicinity of the other focal point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an LED linear light source using a light emitting diode as a light source.

[Conventional technology]

BACKGROUND ART Conventionally, in LED linear light sources using light emitting diodes as light sources, various structures have been devised in order to effectively radiate the light emitted by the light emitting elements of each light emitting diode in the front direction. Fig. 13 is a schematic perspective view of a conventional LED linear light source using a lens and a reflector, and Fig. 14 is its B-3.
It is a schematic sectional view. In FIGS. 13 and 14, l is a light emitting element, 11 is an insulating substrate, 12 and 13 are circuit patterns, 14 is a wire, 15 is a reflective mirror made of a highly reflective resin material, and 16 is a cylindrical resin lens. be.

A plurality of light emitting elements 7-1 arranged in the same straight line -L are closely mounted at equal intervals in the center of the insulating substrate 11, and are electrically connected to each other by circuit patterns 12 and 13 and wires 14. ing. In addition, reflective mirrors 15 are provided on both sides of the insulating substrate 11 along the linearly arranged light emitting elements, and a cylindrical resin lens 16 is provided on the second part of the insulating substrate 11. ing.

According to the LED flocculent light source configured as shown in FIG. is intensified and radiated to the outside. Further, the light emitted in the side direction is diffusely reflected by a reflecting mirror 15 made of a highly reflective resin material, and then passed through a resin lens 16 and radiated to the outside. Furthermore, since the light emitting elements 1 are closely mounted on the same straight line, the irradiation surface has uniform illuminance.

[Problem to be solved by the invention]

However, in the conventional LED linear light source, the light emitting element l
Since the light emitted in the side direction is diffusely reflected by the reflecting mirror 15 made of a highly reflective resin material, only a small amount of the light efficiently reaches the lower end surface of the resin lens 16. In addition, the light reflected by the reflecting mirror 15 and reaching the resin lens 16 is
Since the angle of incidence on the lower end surface of the resin lens 16 is the difference,
There is little radiation directed toward the front. For this reason, in conventional LIF and D linear light sources, most of the light that is diffusely reflected by the reflector [5] does not contribute to the luminous intensity in the front direction of the LED VA light source and becomes wasted light. It had the disadvantage of poor radiation efficiency.

In addition, in conventional LED linear light sources, it is necessary to mount the light emitting elements I closely in order to obtain uniform irradiation light.
There was a drawback that the output of the light emitting element 1 decreased due to heat generated during lighting, and the lifespan of the light emitting element 7-1 became >ii.

The present invention has been made based on the above circumstances, and it is possible to improve the irradiation efficiency of the irradiation surface to which the light emitting element emits light, and also to reduce the output of the light emitting element due to the heat generated by the light emitting element during lighting. It is an object of the present invention to provide LED linear light dIλ that can prevent a decrease in energy consumption and deterioration of a light emitting element.

[Means to solve the problem]

-1- I] LED which is the present invention for achieving the objective
The linear light source includes a light emitting element, a lead portion for supplying power to the light emitting element, and i; 1, the linear light source is provided facing the light emitting surface of the light emitting element, and reflects the light emitted by the light emitting element to form a focused light. a concave reflective surface, an optical waveguide that converts light focused by the concave reflective surface into linear light, and a space between the concave reflective surface and the optical waveguide, and the light emitting element. a light-transmitting material that fills a space in which the tip end of the lead portion is arranged, the light emitted by the light emitting element is reflected on the concave reflective surface to become a focused light, and the focused light is transmitted into a line through an optical waveguide. It is configured to convert the light into light and radiate it to the outside.

Furthermore, a plurality of LED linear light sources having the above configuration may be combined with different emission wavelengths of the light emitting elements.

Further, it is preferable that the concave reflective surface is formed into an ellipsoidal shape.

Further, the optical waveguide may be formed by forming a plurality of linear optical waveguides, with the entrance ports formed in a bundle and the radiation ports formed in a linear shape, and a planar optical waveguide may be bonded to the radiation ports of the plurality of linear optical waveguides. Alternatively, the entrance port of the planar optical waveguide may be formed in a circular shape, and the emission port may be formed in a linear shape.

[Effect]

With the above configuration, the present invention supplies power to the light emitting element from the lead part, once reflects the light emitted by the light emitting element on a concave reflective surface to form a focused light, and further converts the focused light into linear light through an optical waveguide. After conversion, it is radiated to the outside.

In addition, by combining a plurality of LED linear light sources with different emission wavelengths of light emitting elements, 1. Polychromatic or mixed colored light can be emitted.

In addition, by forming the concave reflective surface into an elliptical shape,
For example, by arranging a light emitting element at one focal point and an entrance of the optical waveguide near the other focal point, the light emitted by the light emitting element can be efficiently focused and input into the optical waveguide.

Furthermore, the optical waveguide may include a plurality of linear optical waveguides in which an entrance port is formed in a bundle and a radiation port is formed in a linear shape, or a planar optical waveguide may be bonded to the radiation port of the plurality of linear optical waveguides. The focused light can be easily and reliably converted into linear light by using a circular light beam or by using a planar light beam with a circular incident aperture (:1) formed into a linear shape. When a planar light waveguide is used as an optical waveguide, the emitted light emitted to the outside is made uniform by the planar light wavepath.

〔Example〕

The first embodiment of the present invention will be described below with reference to FIGS. 1 to 3.
1<(This will be explained as follows. Fig. 1 is a schematic conceptual diagram of an LED linear light source that is the first embodiment of the present invention, and Fig. 2 (a) is a schematic enlarged view of the entrance of the optical waveguide. , and the same figure (b)
3 is a schematic partial enlarged view of the radiation aperture of the optical waveguide, and FIG. 3 is an optical path diagram of the light emitted by the light emitting element. Figures 1 to 3
In the figure, 1 is a light emitting element, 2 and 3 are lead frames that supply power to the light emitting element l, 4 is a wire, 5 is a light-transmitting material, and 5a is an ellipsoid that reflects and focuses the light emitted by the light emitting element l. 6 is a plurality of linear optical waveguides 6
This is an optical waveguide that converts focused light into linear light.

Note that the arrow indicates the optical path of light emitted by the light emitting element 1.

The light emitting element 1 is mounted on one lead frame 2,
It is electrically connected to the other lead frame 3 by a wire 4 . In addition, the light emitting element 1 and lead frames 2 and 3
The distal end portion is molded with a light-transmitting material 5. The reflective surface 5a is formed by forming the surface of the optical i3-transmissive material 5 that faces the light emitting surface of the light emitting element 1 into an ellipsoidal shape, and mirror-finishing the surface by plating, metal vapor deposition, or the like. Each linear optical waveguide 6a of the optical waveguide 6 is bundled into a bundle at the entrance 6b where light enters, as shown in FIG. 2 (a), and emits light to the outside as shown in FIG. The radiation 16C is arranged linearly. A reflective surface 5a formed in an elliptical shape
The light emitting element 1 is arranged at one focal point, and the entrance 6b of the optical waveguide 6 is arranged near the other focal point. Note that the space between the entrance 6b of the optical waveguide 6 and the reflective surface 5a is filled with a light-transmitting material 15. In addition, when performing plating or metal vapor deposition to form the reflective surface 5a, the lead frame 2.
Insulate between 3.

According to the above configuration, the lead frames 2 and 3 and the wire 4
As a result, power is supplied to the light emitting element 1, and the light emitting element 1 emits light. The light emitted by the light emitting element 1 is reflected by the reflective surface 5a as shown by the arrow in FIG. 3, and after being focused,
The light is emitted to the entrance 6b of the optical waveguide 6, converted into linear light by the optical waveguide 6, and emitted to the irradiation surface 7. The diameter and number of each linear optical waveguide 6a of the four optical waveguides 6 to be used are appropriately selected depending on the application.

The line width of lead frames 2 and 3 is easily 20°1H.
1 or less, and the area occupied by the light emitting element 1 is approximately 0,4 @I Since the loss due to the shadow between lead frame 1 and lead frames 2 and 3 is about 3%, efficiency -E is not particularly problematic.

According to the present embodiment described in 1:, the light emitted by the light emitting element l is efficiently inputted into the optical waveguide 6 by the reflecting surface 5a, and
Since the light can be emitted linearly onto the irradiation surface 7 through the optical waveguide 6, the illuminance on the irradiation surface 7 can be improved when the same number of light emitting elements is used compared to the conventional LvDvA type light source. can. Furthermore, the same illuminance as the conventional LED linear light source can be obtained with a smaller number of light emitting elements than the number of light emitting elements used in the conventional LED linear light source.

Furthermore, according to the above embodiment, the light emitting elements 1 are not mounted closely as in conventional LED linear light sources, so the output of the light emitting elements I decreases when turned on, unlike in conventional LED linear light sources. There is no possibility that the light emitting element l will deteriorate.

Further, according to the present embodiment described above, the line width of the linear light can be made thin, so when used as a light source for reading, etc., it is possible to improve the accuracy of reading, etc.

Furthermore, the spaces between the light emitting element l and the reflective surface 5a and between the reflective surface 5a and the entrance 6b of the optical waveguide 6 are filled with the light-transmitting material 5, and there is no intervening air layer, so there is little loss of light due to interface reflection. .

In the above embodiment, when a large number of ED linear light sources are arranged, the light emitting elements 1 may be arranged and connected to a transparent insulating circuit board, and a heat sink may be provided as necessary.

FIG. 4 is a schematic conceptual diagram of a LIED linear light source which is a second embodiment of the present invention, and FIG. 5 is a schematic partial enlarged view of its radiation aperture.
FIG. 6 is a schematic partially enlarged view showing a modified example of the radiation port. In the second embodiment shown in FIGS. 4 to 6 and other embodiments described below, those having the same functions as the first embodiment shown in FIGS. 1 to 3 above are the same. Detailed explanation will be omitted by adding the reference numerals.

In FIGS. 4 to 6, la and 1b are light-emitting elements whose emission colors are red and yellow-green, respectively, 6d is a linear optical waveguide that emits red light, and 6e is a line that emits yellow-green light. It is a shaped optical waveguide. In the second embodiment of the present invention, two sets of LED linear light sources according to the first embodiment are arranged, one light emitting element 1a emits red light, and the other light emitting element 1b emits yellow-green light. As shown in FIG. 5, the radiation port 6c has linear optical waveguides 6d that emit red light and linear optical waveguides 6e that emit yellow-green light, which are alternately arranged. Incidentally, the radiation aperture 6c may have a linear optical waveguide 6d and a linear optical four-wave path 6e arranged in parallel, as shown in FIG.

According to the second embodiment, by alternately lighting up the light emitting element 1a and the light emitting element lb, the multicolor LED N>'
It becomes an IT-like light source. Other functions and effects are similar to those of the first embodiment. In addition, in the above-mentioned second embodiment, the case where two sets of LED linear light sources are arranged, which is the first embodiment, was explained, but this is the case where three or more sets of LED linear light sources are arranged, for example, red, blue, yellow. It is also possible to arrange 3Mi of light emitting elements each having an emission wavelength of , and to simultaneously light up the three navy blue lights to emit white illumination light.

FIG. 7 is a schematic conceptual diagram of an LED gradual light source which is a third embodiment of the present invention, FIG. 8 is a schematic partial enlarged view of the radiation opening of the optical waveguide, and FIG. 9 is a linear optical waveguide and a planar shape. It is 1Δ which indicates the radiation state of light at the junction with the optical waveguide. In FIGS. 7 to 9, 5f is a four-wave path of planar light.

The third embodiment is a plurality of four linear optical wave paths 6a of the first embodiment.
A planar optical waveguide 6f is bonded to the tip of the optical waveguide. That is, the optical waveguide 6 of the third embodiment is a combination of a plurality of linear optical waveguides 6a and a planar optical waveguide 6''. An optical waveguide is formed by providing a cladding layer made of a low refractive index material on the side surface of the refractive index material.

The light emitted from each linear optical waveguide 6a does not spread in the direction perpendicular to the plane of the paper in FIG. 9, but spreads in the horizontal direction with respect to the plane of the paper, as shown in FIG. Therefore, even if there is variation in the light transmitted by each linear optical waveguide 6a, it is made uniform when passing through the planar optical waveguide 6'' and is emitted to the outside. According to the embodiment, since the planar optical waveguide 6f is provided at the tip of the linear optical waveguide 6a, the light emitted from the linear optical waveguide 6a is spread within the one square optical waveguide 6f and is made uniform. It is emitted to the outside.Other functions and effects are the same as in the first embodiment.
- In the embodiment described above, a case has been described in which a planar optical waveguide is bonded to the optical waveguide of the first embodiment, but a planar optical waveguide may be bonded to the optical waveguide of the second embodiment. This makes it possible to emit uniform red light or yellow-green light.

FIG. 10 is a schematic conceptual diagram of the LI2DI2 light source which is the fourth embodiment of the present invention, FIG. 11(a) is a schematic enlarged view of the entrance of the optical waveguide, and FIG. FIG. 12 is a schematic partial enlarged view of the mouth, FIG. 12 is an optical path diagram of light emitted by the light emitting element, and FIG. 13 is a schematic diagram showing a modification thereof.

The fourth embodiment of the present invention differs from the first embodiment in that the four optical wave paths 6 are formed by planar optical waveguides 6r.

Note that the four planar light wave paths 5 may be formed by coating the side surfaces with a material having a low refractive index to form a crat layer. Moreover, the planar optical waveguide 6f is not a flat one,
For example, it may be curved.

As shown in FIG. 12, the LCD linear light source of this embodiment reflects and focuses light emitted by a light emitting element 1 on a concave reflecting surface 5a, and converts it into cotton-like light using a planar optical waveguide 6r. radiates to the outside. The planar optical waveguide 6f used in this example is easy to form, and the light emitting element 1 is
When molding, it is also possible to simultaneously form the planar optical waveguide 6f. Therefore, in this example, L
CD linear light sources are easy to mass produce. Other functions and effects are similar to those of the first embodiment.

Further, as shown in FIG. 13, a structure may be adopted in which a plurality of sets of light emitting elements l and reflective surfaces 5a are provided for one planar optical waveguide 6r. A shaped light source can be easily manufactured.

Note that in the first to fourth embodiments described above, the light emitting element 1
The lead part that supplies power to the lead frame 2 is mainly
3 and wire 4, the present invention is not limited to this. For example, the lead portion may be a transparent glass substrate on which a stem or fine line circuit is formed.

〔Effect of the invention〕

As explained above, according to the present invention, the light emitted by the light emitting element is reflected and focused by the concave reflective surface, and then converted into linear light by the optical waveguide, so that the light emitted by the light emitting element is directed to the irradiation surface. To provide an LCD linear light source that can improve the irradiation effect and the direction of radiation, and can prevent a decrease in the output of the light emitting element due to heat generation of the light emitting element during lighting, and prevent deterioration of the light emitting element. I can do it.

[Brief explanation of the drawing]

FIG. 1 shows the first embodiment of the present invention, and FIG. 2(a) is a schematic enlarged view of the incident L1 of the optical waveguide. b) is a schematic partial enlarged view of the radiation aperture of the optical waveguide, FIG. 3 is an optical path diagram of the light emitted by the light emitting element, and FIG. 5 is a schematic partial enlarged view of the radiation port, FIG. 6 is a schematic partial enlarged view showing a modified example of the radiation port, and FIG. 7 is a third embodiment of the LCD of the present invention. A schematic conceptual diagram of a linear light source, FIG. 8 is a schematic partial enlarged view of the radiation aperture of the optical waveguide, and FIG. 9 is a diagram showing the state of light emission at the junction between the linear optical waveguide and the planar optical waveguide. FIG. 10 is a schematic conceptual diagram of an LCD linear light source which is a fourth embodiment of the present invention, FIG. 11(a) is a schematic enlarged view of the entrance of the optical waveguide, and FIG. 11(b) is the optical waveguide. Fig. 12 is a diagram of the optical path emitted by the light emitting element, Fig. 13 is a schematic diagram showing a modified example, and Fig. 14 is a conventional LCD line using lenses and reflectors. A schematic perspective view of a shaped light source, and FIG. 15 is a schematic sectional view of the light source along line 13-I3. 1...2 light emitting elements, 2, 3..., lead frame, 4,
...Wire, 5.・, Light-transmissive material, 5a... Reflective surface, 6... Optical waveguide, 6a... Linear optical waveguide, 6 f
,, Planar optical waveguide. Iwasaki Electric Co., Ltd. Figure 5 Figure 6 Figure 3 Figure 4 Figure 1○ Figure 11 CG) (b) Figure 12 Figure 13

Claims (6)

[Claims] (1) A light-emitting element, a lead portion that supplies power to the light-emitting element, and a concave reflective surface that is provided opposite to the light-emitting surface of the light-emitting element and that reflects the light emitted by the light-emitting element into focused light. an optical waveguide that converts the light focused by the concave reflective surface into linear light; a space between the concave reflective surface and the optical waveguide, and a tip portion of the light emitting element and the lead portion. and a light-transmitting material that fills a space in which the light emitting element is arranged, the light emitted by the light emitting element is reflected on the concave reflective surface to become a focused light, and the focused light is converted into linear light by an optical waveguide. LE characterized by being configured to radiate to the outside
D linear light source. (2) An LED linear light source formed by combining a plurality of LED linear light sources described in item 1 with different emission wavelengths of light emitting elements. (3) The LED linear light source according to claim 1 or 2, wherein the concave reflective surface is formed in an ellipsoidal shape. (4) The optical waveguide is composed of a plurality of linear leading waveguides,
4. The LED linear light source according to claim 1, wherein the entrance port through which light enters is formed in a bundle shape, and the radiation port through which light is emitted is formed in a linear shape. (5) The optical waveguide is composed of a plurality of linear optical waveguides in which an entrance port is formed in a bundle shape and a radiation port is formed in a linear shape, and a planar optical waveguide joined to the radiation port of the plurality of linear optical waveguides. The LED linear light source according to any one of claims 1 to 3. (6) The LED linear light source according to any one of claims 1 to 3, wherein the optical waveguide is a planar optical waveguide, and has an entrance port formed in a circular shape and a radiation port formed in a linear shape.