JP2007318176A - Light emitting diode - Google Patents

Abstract

[PROBLEMS] To take advantage of the thinness that is a feature of LEDs and to have a good appearance and to irradiate a large area with a single light emitting element, and to obtain high external radiation efficiency.
The light emitting device includes an electric system (5a, 5b, 7) for supplying electric power, and a light transmissive material (8) for sealing the light emitting device (6) and the electric system (5a, 5b, 7). The flat surface 9a at the center of the upper surface formed on the side surface and the lateral direction of the shape formed by a part of a parabola without spreading the light emitted from the light emitting element 6 by the light transmissive material 8 continuing from the flat surface 9a in the vertical direction. The light-emitting element 6 is molded at the focal position of the reflective surface 9 that reflects to the side surface and the side-surface radiation surface 10 that is formed of a part of an ellipse that radiates outside the light reflected in the side surface direction in the vertical direction. is doing.
[Selection] Figure 1

Description

  The present invention relates to a light emitting diode (hereinafter also abbreviated as “LED”) used as a light source for an LED light applied to an illumination device such as a vehicle-mounted light, a display device, or the like.

  In this specification, the LED chip itself is referred to as a “light emitting element”, and the entire light emitting device including an optical device such as a package resin or a lens system on which the LED chip is mounted is referred to as a “light emitting diode” or “LED”. I will do it. Further, an illumination device such as an in-vehicle light using LED as a light source, a display device, and the like will be referred to as “LED light”.

  With the increase in luminance of light emitting elements, LED lights using LEDs as light sources have been increasingly used for automobile backlights and the like. The LED has a sharp spectrum and good visibility. In addition, since the response speed is fast, the signal transmission speed to the following vehicle is high, and a remarkable effect is recognized in shortening the stationary distance during high-speed driving. Furthermore, since the LED itself is a monochromatic light source, it is not necessary to filter light other than the necessary color like an incandescent light bulb, and it is highly efficient as a monochromatic light source, leading to energy saving.

  An example of such an LED light is shown in FIG. FIG. 8 is a cross-sectional view showing an overall configuration of an example of a conventional LED light.

  As shown in FIG. 8, the LED light 100 uses a lens-type LED 101 in which a light-emitting element 102 is sealed in a convex lens shape with a transparent epoxy resin 105 as a light source. In the lens-type LED 101, the light emitting element 102 is mounted on the lead 103a of the pair of leads 103a and 103b, the light emitting element 102 and the lead 103b are bonded with the wire 104, and the whole is formed into a convex lens shape with the transparent epoxy resin 105. It is sealed. The periphery of the convex lens type LED 101 is covered with a rotary paraboloidal reflecting mirror 106, and a Fresnel lens 107 is formed in the upper center portion. After all, the light emitted from the lens type LED 101 is reflected by the reflecting mirror 106. Alternatively, the light is condensed by the Fresnel lens 107 and is emitted upward substantially in parallel. Then, the light that is spread by the uneven surface provided on the lower surface of the resin lens 109 and passes through the resin lens 109 is radiated to the outside as radiated light having a spread of about 20 degrees, which is a standard for a vehicle-mounted backlight. .

  However, now that the output of the light emitting elements has been further improved, it has become necessary to emit light of a predetermined area with a small number of light emitting elements. This is in order to reduce the number of components and reduce the labor of component mounting. However, in the LED light 100 using the above-described convex lens-shaped LED 101, if a single light-emitting element emits a larger area, it becomes a similar shape and becomes larger in the area direction and also in the thickness direction. Become thicker. Also, if you try to make it thinner, the appearance will deteriorate. For this reason, there existed a problem that it cannot be set as the thin light source which is the characteristics of LED. Furthermore, since light that does not reach the reflecting mirror 106 or the Fresnel lens 107 from the light emitting element 102 cannot be externally emitted without being optically controlled, there is still a problem in terms of external radiation efficiency.

  Accordingly, the present invention provides an LED as a light source for an LED light that can illuminate a large area with a single light emitting element and can obtain high external radiation efficiency while taking advantage of the thinness that is a feature of LEDs. Is an issue.

  The light-emitting diode according to the invention of claim 1 includes an electric system that supplies power to the light-emitting element, and the light-emitting element and a light-transmitting material that seals the electric system, and is formed on the light-emitting element. A flat surface, a reflective surface that reflects light emitted from the light emitting element by the light transmissive material that continues from the flat surface in a vertical direction without spreading light in the vertical direction, and the side surface A side emission surface having a shape of a part of an ellipse that radiates outside without spreading light reflected in the direction in the vertical direction is formed by molding the light emitting element at the focal position.

Thus, the light emitted from the light emitting element is made incident on the reflecting surface which is the upper surface of the light transmissive material sealing the light emitting element at an angle larger than the critical angle. This eliminates the need for surface treatment such as plating and vapor deposition in order to produce LED reflectors, and it is only necessary to adjust the shape of the sealing mold. Costed. In addition, the side surface of the light transmissive material is transmitted as it is to the side surface by radiating the light reflected in the side surface direction without spreading in the vertical direction, and then reflected upward by the peripheral reflecting mirror outside the LED. Is done. Since the light reflected in the side surface direction is reflected without spreading in the vertical direction, the thickness of the peripheral reflecting mirror that reflects the reflected light upward can be reduced. As a result, light emitted from the light emitting element to the upper and side surfaces of the light-transmitting material is reflected upward by the peripheral reflecting mirror, making it suitable for LED lights with high external radiation efficiency while taking advantage of the thin features of LEDs. A light emitting diode.
Furthermore, since all the light reflected on the side surface is optically controlled and reflected upward, it is emitted outside, so that high external radiation efficiency can be obtained.

  A light emitting diode according to a second aspect of the present invention includes an electric system that supplies power to the light emitting element, and the light emitting element and a light-transmitting material that seals the electric system, and is formed on the light emitting element. A flat surface, a reflective surface that reflects light emitted from the light emitting element by the light transmissive material that continues from the flat surface in a vertical direction without spreading light in the vertical direction, and the side surface A side emission surface having a shape of a part of a spherical surface that radiates outside the light reflected in the direction without spreading in the vertical direction molds the light emitting element at the focal position.

Thus, the light emitted from the light emitting element is made incident on the reflecting surface which is the upper surface of the light transmissive material sealing the light emitting element at an angle larger than the critical angle. This eliminates the need for surface treatment such as plating and vapor deposition in order to produce LED reflectors, and it is only necessary to adjust the shape of the sealing mold. Costed. In addition, the side surface of the light transmissive material is transmitted as it is to the side surface by radiating the light reflected in the side surface direction without spreading in the vertical direction, and then reflected upward by the peripheral reflecting mirror outside the LED. Is done. Since the light reflected in the side surface direction is reflected without spreading in the vertical direction, the thickness of the peripheral reflecting mirror that reflects the reflected light upward can be reduced. As a result, light emitted from the light emitting element to the upper and side surfaces of the light-transmitting material is reflected upward by the peripheral reflecting mirror, making it suitable for LED lights with high external radiation efficiency while taking advantage of the thin features of LEDs. A light emitting diode.
Furthermore, since all the light reflected on the side surface is optically controlled and reflected upward, it is emitted outside, so that high external radiation efficiency can be obtained. In particular, the side radiation surface is a spherical surface, and has the same effect as the side radiation surface having a shape of a part of an ellipse that radiates outside the light reflected in the side surface direction without spreading up and down. .

  The reflecting surface of the light emitting diode according to the invention of claim 3 reflects light in a range of 60 degrees or more with respect to the central axis of the light emitting element.

  According to a fourth aspect of the present invention, there is provided a light emitting diode having a second reflecting mirror for reflecting upward the light emitted to the side of the light emitting element in the vicinity of the light emitting element.

  The second reflecting mirror of the light emitting diode according to the invention of claim 5 comprises a lead forming the electric system for supplying electric power to the light emitting element.

The light-emitting diode according to the invention of claim 1 includes an electric system that supplies power to the light-emitting element, and the light-emitting element and a light-transmitting material that seals the electric system, and is formed on the light-emitting element. A flat surface, a reflective surface that reflects light emitted from the light emitting element by the light transmissive material that continues from the flat surface in a vertical direction without spreading light in the vertical direction, and the side surface A side emission surface having a shape of a part of an ellipse that radiates outside without spreading light reflected in the direction in the vertical direction is formed by molding the light emitting element at the focal position.
Accordingly, the first reflecting mirror that reflects the light without being spread in the vertical direction in the side surface direction is installed immediately above the light emitting element, and the peripheral reflecting mirror that reflects the reflected light upward is provided around the LED, thereby As the reflecting mirror is separated from the first reflecting mirror, it is possible to obtain a large area of external radiation. Further, since the light reflected in the side surface direction is reflected without spreading in the vertical direction, the thickness of the peripheral reflecting mirror that reflects the reflected light upward can be reduced. Furthermore, since all the light reflected on the side surface is optically controlled and reflected upward and emitted externally, high external radiation efficiency can be obtained.
In this way, taking advantage of the thinness that is a feature of the LED, a light-emitting diode for LED light that can illuminate a large area with a single light-emitting element and can obtain high external radiation efficiency, and Become.

A light emitting diode according to a second aspect of the present invention includes an electric system that supplies power to the light emitting element, and the light emitting element and a light-transmitting material that seals the electric system, and is formed on the light emitting element. A flat surface, a reflective surface that reflects light emitted from the light emitting element by the light transmissive material that continues from the flat surface in a vertical direction without spreading light in the vertical direction, and the side surface A side emission surface having a shape of a part of a spherical surface that radiates outside the light reflected in the direction without spreading in the vertical direction molds the light emitting element at the focal position.
That is, the light emitted from the light emitting element is made incident at an angle larger than the critical angle on the reflecting surface which is the upper surface of the light transmissive material sealing the light emitting element. This eliminates the need for surface treatment such as plating and vapor deposition in order to produce LED reflectors, and it is only necessary to adjust the shape of the sealing mold. Costed. In addition, the side surface of the light transmissive material is transmitted as it is to the side surface by radiating the light reflected in the side surface direction without spreading in the vertical direction, and then reflected upward by the peripheral reflecting mirror outside the LED. Is done. As a result, light emitted from the light emitting element to the upper and side surfaces of the light-transmitting material is reflected upward by the peripheral reflecting mirror, making it suitable for LED lights with high external radiation efficiency while taking advantage of the thin features of LEDs. A light emitting diode. In particular, since the side radiating surface is formed of a spherical surface, the same effect as the side radiating surface having a shape of a part of an ellipse that radiates outside the light reflected in the side surface direction without spreading in the vertical direction is obtained.

  In the light-emitting diode according to the invention of claim 3, since the reflecting surface reflects light in a range of 60 degrees or more with respect to the central axis of the light-emitting element, in addition to the effects of claim 1 or claim 2, Thus, all the light emitted within a range of 60 degrees from the central axis of the upper surface of the light emitting element is reflected in the lateral direction, and the light emitted within a range larger than 60 degrees from the central axis is directed directly to the lateral direction. Is also reflected upward by the peripheral reflector. Therefore, most of the light emitted from the light emitting element is emitted from the LED light to the outside, so that the LED light for the LED light has extremely high external radiation efficiency.

  The light-emitting diode according to the invention of claim 4 is provided with a second reflecting mirror that reflects upward the light emitted to the side of the light-emitting element in the vicinity of the light-emitting element. In addition to the effect described in any one of Items 3, the light is also emitted upward from the periphery of the light emitting element, and the whole appears to emit light, thereby improving the appearance. Is obtained.

  The light-emitting diode according to the invention of claim 5 is composed of a lead that forms the electric system in which the second reflecting mirror supplies power to the light-emitting element. While light is emitted only directly above the light emitting element, light is also emitted upward from the periphery of the light emitting element, so that the whole appears to emit light and looks good. The effect of improving is acquired.

Embodiments of the present invention will be described below with reference to the drawings.
[Embodiment 1]
First, Embodiment 1 of the present invention will be described with reference to FIG. 1 and FIG.
FIG. 1 is a longitudinal sectional view showing the overall configuration of an LED according to Embodiment 1 of the present invention. 2A is a plan view showing the overall configuration of the LED light using the LED according to the first embodiment of the present invention, FIG. 2B is a cross-sectional view taken along the line AA of FIG. 2A, and FIG. It is an enlarged view of P part.

  First, the configuration of the LED 2 of the first embodiment will be described with reference to FIG. Here, the central axis of the light emitting element is the Z axis, the upper surface of the light emitting element is the origin, and the X axis and the Y axis intersect at a right angle at this origin. The same applies to the following embodiments.

  As shown in FIG. 1, a light emitting element 6 is mounted on the tip of a lead plate 5a having a large area among a pair of lead plates 5a and 5b provided on the XY plane. The electrode on the upper surface of the light emitting element 6 and the tip of the lead plate 5b are bonded by a wire 7 to be electrically connected. The leading ends of the lead plates 5a and 5b as the electrical system, the light emitting element 6, and the wire 7 are set in a resin sealing mold, and the cross-sectional shape as shown in the figure by a transparent epoxy resin 8 as a light transmitting material. It is sealed with resin. Here, the central portion of the upper surface of the LED 2 has a flat surface 9a. Following the flat surface 9a, the first reflecting mirror is focused on the center of the light emitting surface of the light emitting element 6, and the X-axis direction is the axis of symmetry. It is shaped like an umbrella in which a part of a parabola to be rotated (range of 60 degrees with respect to the Z axis) is rotated around the Z axis. Further, the side surface 10 of the LED 2 forms a part of a spherical surface centering on the light emitting element 6.

  That is, in the LED 2 of the first embodiment, the transparent epoxy resin 8 as the light transmissive material reflects the light emitted from the light emitting element 6 in the vertical direction without spreading the light emitted from the light emitting element 6; The side radiation surface 10 that radiates outside the light reflected in the side surface direction without spreading in the vertical direction is molded.

  Next, as shown in FIG. 2, the LED light 1 using the LED 2 of the first embodiment has the LED 2 as a light source mounted at the center of a circular main body, and the periphery of the LED light 1 is a concentric circle as a peripheral reflector. The structure is surrounded by a step-like reflecting mirror 3. As shown in FIG. 2C, the reflecting surface 3a of the reflecting mirror 3 is inclined at about 45 degrees with respect to the XY plane of the drawing. The reflecting mirror 3 is formed of a transparent acrylic resin, and then aluminum is deposited to form a reflecting surface.

  A method of lighting the LED light 1 having such a configuration will be described with reference to FIGS. When voltage is applied to the lead plates 5a and 5b of the LED 2 to cause the light emitting element 6 to shine, the light emitted from the light emitting element 6 passes through the transparent epoxy resin 8 as it is in the Z direction, that is, directly above. It goes straight and passes through a transparent front plate (not shown) placed on the LED light 1 and is emitted to the outside. Of the light emitted from the light emitting element 6, light within a range of 60 degrees or more with respect to the Z axis reaches the upper surface 9 as the first reflecting mirror, and all of these lights have a large incident angle. Reflected toward the side 10. Here, since the upper surface 9 has a shape in which a part of a parabola with the light emitting element 6 as a focal point and the X axis as a symmetry axis is rotated around the Z axis, all the light reflected by the upper surface 9 is X−. Since the light travels parallel to the Y plane and the side surface 10 forms a part of a spherical surface centered on the light emitting element 6, the light travels almost in parallel and is emitted in a substantially planar shape around 360 degrees around the Z axis. . Further, the light directed directly from the light emitting element 6 to the side surface 10 is emitted in the same direction without being refracted because the side surface 10 forms a part of a spherical surface centering on the light emitting element 6.

  There is a step-like reflecting mirror 3 as a peripheral reflecting mirror, and there is a reflecting surface 3a having an inclination of about 45 degrees, but the light reflected by the upper surface 9 and traveling substantially parallel to the XY plane. Since the light directly radiated from the side surface 10 is also almost parallel to the XY plane, the light reflected by the reflecting surface 3a travels almost vertically upward and is at least 20 degrees from the Z axis. Inside, the light is emitted outside through a transparent front plate (not shown). Note that the light expressed as “parallel” in the above is not perfectly parallel because of the size of the light emitting element 6, but any light is almost parallel and is at least 20 degrees from the Z axis. It will surely be inside.

In this way, the LED 2 of the first embodiment is thin and can irradiate a large area with a single light emitting element by taking advantage of the thinness that is a feature of the LED, and obtain high external radiation efficiency. It becomes a light source suitable for the LED light 1 that can
[Embodiment 2]

  Next, an LED according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 3 is a longitudinal sectional view showing the overall configuration of the LED according to the second embodiment of the present invention.

As shown in FIG. 3, the LED 11 according to the second embodiment has a pair of lead plates 12 a and 12 b that are recessed only around the light emitting element 6 to form a second reflecting mirror. As a result, in the basic form of FIG. 1, light is emitted directly upward only above the light emitting element 6, whereas light is also emitted upward from the periphery of the light emitting element 6 in the LED 11, The whole appears to emit light, and the effect of improving the appearance is obtained.
[Embodiment 3]

Next, an LED according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 4 is a longitudinal sectional view showing the overall configuration of the LED according to the third embodiment of the present invention.
In the LED 16 of the third embodiment, the pair of lead plates 13a and 13b is obliquely separated from the light emitting element 6 by providing a pattern as a second reflecting mirror as shown in FIG. 4 by half etching or a stamping pattern. The light emitted downward is reflected to emit light upward. By forming a plurality of concentric reflecting mirrors in this way, it can appear as if the whole is emitting light as in the second embodiment, and the appearance can be improved. In this case, the adhesion area between the transparent epoxy resin 8 and the lead plates 13a and 13b is increased, and the effect of reducing peeling defects by simultaneously removing the adhesion shape from a planar shape can be obtained. This is particularly effective in the case of a large current type that generates a large amount of heat.
[Embodiment 4]

  Next, LED of Embodiment 4 of this invention is demonstrated with reference to FIG. FIG. 5 is an explanatory view showing a side shape of the LED according to the fourth embodiment of the present invention.

In LED17 of this Embodiment 4, as FIG. 5 shows, the side surface shape of the sealing part by the transparent epoxy resin 8 of LED17 is changed. The side surface 10 of the LED 2 of Embodiment 1 is a part of a spherical shape centering on the light emitting element 6, and the light emitted from the light emitting element 6 enters the side surface 10 substantially perpendicularly and goes straight. However, in the third modification, the side surface 14 forms a part of the ellipsoidal surface having the light emitting element 6 as one focal point, and the light emitted from the light emitting element 6 is slightly below the straight traveling direction on the side surface 14. Refracts on. Therefore, even if the step-like reflecting mirror 3 around the LED 2 is brought to a lower position, the LED light can obtain a high external radiation efficiency. As a result, the LED light can be made thinner.
[Embodiment 5]

  Next, an LED according to Embodiment 5 of the present invention will be described with reference to FIG. FIG. 6 is a partially enlarged view showing the upper surface of the LED according to the fifth embodiment of the present invention.

In the LED 18 of the fifth embodiment, as shown in FIG. 6, a part of a parabola with the light emitting element 6 as a focal point is rotated around the Z axis up to the central portion of the upper surface 9. Then, the reflection on the side of the upper surface 9 as a reflection mirror of the LED is not subjected to total reflection at the boundary surface between the transparent epoxy resin 8 and the air, but the upper surface 9 is plated, vapor-deposited, etc., and the metal reflective film 15 is attached. I am letting. As a result, an LED that radiates substantially the entire luminous flux emitted from the light emitting element 6 to the side surface including the light emitted directly from the light emitting element 6 is obtained.
[Comparative example]

  Here, a comparative example with each embodiment of the present invention will be described with reference to FIG. FIG. 7 is a longitudinal sectional view showing the overall configuration of an LED according to a comparative example with each embodiment of the present invention.

  As shown in FIG. 7, in the LED 31 of this comparative example, the light emitting element 34 is mounted at the tip of the lead plate 33a of the pair of lead plates 33a and 33b, and the electrode on the upper surface of the light emitting element 34 and the lead plate 33b The tip is bonded by a wire 35 to make an electrical connection. The leading ends of the lead plates 33a and 33b as the electrical system, the light emitting element 34, and the wire 35 are sealed with a transparent epoxy resin 36 as a light transmissive material. The outer shape of the transparent epoxy resin 36 has a shape in which the upper part of a spherical half (convex lens shape) centering on the light emitting element 34 is conical. In this case, the light emitted from the light emitting element 34 is almost totally reflected by the upper surface 32, but the reflected light corresponds to the radiated light from the reflection point of the light emitting element 34 with respect to the upper surface 32. Instead, the light is radiated from the side surface 37 with a spread angle. Therefore, a circular step-like reflecting mirror as a peripheral reflecting mirror that reflects these lights upward is also required to be longer in the Z direction than the LED 2 used in the first embodiment.

  Thus, in LED31 concerning this comparative example, it cannot be made thin as an LED light, and external radiation efficiency cannot be made high, and the objective of this invention is not achieved.

In each of the above embodiments, a transparent epoxy resin is mainly used as a light transmissive material for sealing a light emitting element or the like, but other light transmissive materials may be used.
In each of the above embodiments, the light emitting element is mounted on one of the pair of lead plates, but may be mounted on a circuit board on a metal plate. By mounting a light emitting element on a metal plate with excellent thermal conductivity in this way, heat dissipation is greatly improved, and thermal saturation does not occur even when a large current is supplied to the light emitting element, resulting in a large light output. There is an advantage that can be obtained.

  The configuration, shape, quantity, material, size, connection relationship, and the like of the other parts of the light emitting diode are not limited to the above embodiments.

FIG. 1 is a longitudinal sectional view showing the overall configuration of an LED according to Embodiment 1 of the present invention. 2A is a plan view showing the overall configuration of the LED light using the LED according to the first embodiment of the present invention, FIG. 2B is a cross-sectional view taken along the line AA of FIG. 2A, and FIG. It is an enlarged view of P part. FIG. 3 is a longitudinal sectional view showing the overall configuration of the LED according to the second embodiment of the present invention. FIG. 4 is a longitudinal sectional view showing the overall configuration of the LED according to the third embodiment of the present invention. FIG. 5 is an explanatory view showing a side shape of the LED according to the fourth embodiment of the present invention. FIG. 6 is a partially enlarged view showing the upper surface of the LED according to the fifth embodiment of the present invention. FIG. 7 is a longitudinal sectional view showing the overall configuration of an LED according to a comparative example with each embodiment of the present invention. FIG. 8 is a cross-sectional view showing an overall configuration of an example of a conventional LED light.

Explanation of symbols

2, 11, 16, 17, 18 Light emitting diode (LED)
5a, 5b, 7, 12a, 12b, 13a, 13b Electric system 6 Light emitting element 8 Light transmitting material 9 First reflecting mirror 15 Metal surface

Claims (5)

A light emitting element;
An electric system for supplying power to the light emitting element;
A light transmissive material for sealing the light emitting element and the electrical system,
A flat surface formed on the light-emitting element and a side surface having a part of a parabola without spreading light emitted from the light-emitting element in the vertical direction by the light-transmitting material continuing from the flat surface. A reflecting surface to be reflected and a side radiation surface having a shape of a part of an ellipse that radiates outside the light reflected in the side surface direction in the vertical direction are molded at the focal position. A light emitting diode characterized by that. A light emitting element;
An electric system for supplying power to the light emitting element;
A light transmissive material for sealing the light emitting element and the electrical system,
A flat surface formed on the light-emitting element and a side surface having a part of a parabola without spreading light emitted from the light-emitting element in the vertical direction by the light-transmitting material continuing from the flat surface. The light-emitting element is molded at the focal point of a reflective surface that reflects and a side-surface emitting surface that is formed of a part of a spherical surface that radiates outside the light reflected in the side surface direction without spreading up and down. A light emitting diode characterized by that.   The light emitting diode according to claim 1, wherein the reflective surface reflects light in a range of 60 degrees or more with respect to a central axis of the light emitting element.   The second reflecting mirror that reflects upward the light emitted to the side of the light emitting element is provided in the vicinity of the light emitting element. Light emitting diode.   5. The light emitting diode according to claim 4, wherein the second reflecting mirror includes a lead forming the electric system that supplies electric power to the light emitting element.

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