JPH0983018A - Light emitting diode unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an LED unit suitable for mounting on a board in which the distance between a lens and an LED can be set freely depending on the application and the output light from the LED can be directed collectively in one direction. SOLUTION: The light emitting diode unit comprises an LED 3, a lead frame 5 for feeding an applying voltage thereto, a translucent region 7 for introducing the output light from LED 3 and surrounded by a reflective wall 6 in order to introduce a part thereof in substantially same direction, a condenser lens 2 secured directly above the LED 3 in the translucent region 7, and a support 4A for the condenser lens 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode unit, and more particularly to a high brightness light emitting diode unit suitable for surface mounting on a substrate surface or the like.

[0002]

2. Description of the Related Art Light emitting diodes (LEDs), which have been widely used so far, are formed of semiconductors, as is well known, and emit a visible light of a wavelength determined by a material with a minute size and at a low voltage. It has characteristics such as operating. Therefore, such an LED is used as a photocoupler in combination with a light receiving element such as a phototransistor, is also used as a display element in various electronic devices, and is being used as a light emitting element for optical fiber communication.

[0003]

By the way, in the case of the board mounting type (surface mounting type) LED unit up to now, for example, those manufactured by Hewlett-Packard Company (USA) are formed in a package type so as to be easily mounted. Since the LED is electrically bonded on the lead frame and the surroundings are integrally molded with transparent epoxy resin etc. to create a unit, the light from the LED, which is a non-diffusion type, is scattered to the surrounding area. It is easy to do, and because the brightness or brightness is not increased, it is affected by other light such as sunlight,
When used as a display element, it is difficult to see,
When incorporated in an optical detection element, there is a risk of false detection.

The present invention focuses on the above-mentioned conventional problems, and
It is an object of the invention to provide a light emitting diode unit suitable for a substrate mounting type in which the distance between the condenser lens and the LED can be freely set according to the application.

A second object of the present invention is to provide a light emitting diode unit suitable for a substrate mounting type which is easy to manufacture and can efficiently collect light and output it in one direction.

[0006]

In order to achieve the above object, according to an embodiment of the present invention, a light emitting diode held by a lead frame, a unit base holding the lead frame, and one end side of the unit base are joined to the unit base. A ring-shaped lens support, a reflection wall provided around the center of the lens support so as to surround the light-emitting diode and reflecting light emitted from the light-emitting diode, the reflection wall and the unit base. A condensing lens arranged on the other end side of the lens support so as to close a light-transmitting area surrounded by and a lens fixing means for fixing the condensing lens to the lens support. It is a feature.

According to the present invention, when the output light from the light emitting diode passes through the light transmitting region, a part of the light is reflected by the reflection wall surrounding the light transmitting region, and is directed toward the condenser lens and transmitted. The light enters the condenser lens under the influence of the refractive index of the light region. In this way, the light emitted from the light emitting diode can be made to enter the condenser lens without being diffused to the outside, and the incident light can be emitted to the outside according to the characteristics of the condenser lens. Not only is the effect of increasing the luminous intensity or brightness obtained by collimating or converging the emitted light, but also the emitted light can be set to be freely diversified according to the application, which also contributes to the reduction of the production cost.

[0008]

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

First, as a first embodiment of the present invention, a structure of a light emitting diode (LED) unit with a spherical lens will be described with reference to FIG. As shown in this figure, the LED unit 1 includes a spherical lens 2 and an LED 3
And the supporting body 4 constitute a main part. That is,
The support 4 is integrally molded of a heat resistant resin such as a polyamide resin or a liquid crystal polymer including a lead frame 5 made of a conductor for supplying a bias voltage to the LED 3, and 6 is provided around the LED 3 so as to surround the LED 3. It is a cone-shaped reflective wall with a mirror finish.
The reflective wall 6 may be plated with a metal film or the like in order to enhance the reflection efficiency, but in the present embodiment, an opaque white resin is used as the heat-resistant resin for molding the support 4 so that the molding is performed. At times, the surface of the reflective wall 6 can have a high reflectance.

In the following, the upper half of the support 4 on which the reflection wall 6 is formed around the LED 3 is referred to as a reflector portion (lens support) 4A, and the lower half is referred to as a unit base. The peripheral surface of the reflection wall 6 having a substantially cone shape is in the shape of a truncated cone or a paraboloid of revolution, that is, as much as possible of the light emitted from the LED 3 is reflected toward the spherical lens 2 and transmitted from the spherical lens 2. The light may be set so that the desired light distribution characteristic is obtained. In the present embodiment, the upper edge peripheral portion of the reflection wall 6 that receives the spherical lens 2 of 4A of the reflector portion is matched with the spherical shape of the spherical lens 2 to make it easier to receive the spherical lens 2. However, the upper edge peripheral portion is not necessarily the same. The shape does not have to be such a shape, and in short, as long as the distance R from the center of the spherical lens 2 to the LED 3 is positioned so as to be a predetermined set value, for example, the spherical lens 2 may be received at the upper edge. .

On the other hand, the spherical lens 2 is formed of glass or polyether sulfone (manufactured by ICI, UK) or Arton (manufactured by Japan Synthetic Rubber Co., Ltd.) or the like so as to obtain a predetermined radius r. . Further, in FIG. 1, reference numeral 7 denotes a light-transmitting region above the LED 3 surrounded by the reflecting wall 6. In this embodiment, a light-transmitting heat-resistant epoxy resin is attached to the light-transmitting region 7 in order to mount the ball lens 2 at a predetermined position. The spherical lens 2 was bonded to the reflector portion 4A so that a predetermined amount was filled and no bubbles remained in the light transmitting region 7. As long as the spherical lens 2 is bonded to the reflector portion 4A in a stable state, it is not always necessary to fill the translucent region 7 with a translucent resin, for example, an epoxy resin, and the translucent region 7 is transparent. It goes without saying that a mere air layer may be used or matching oil or the like may be filled as long as it is kept lightable.

LED with lens having the above-mentioned structure
In the element 1, the distance R from the LED 3 to the spherical center 0 of the spherical lens 2 is kept larger than the radius of the spherical lens 2 and the spherical lens 2
Has a refractive index n _R , and the refractive index n _C of the substance in the transparent region 7
By appropriately combining the distance R and the shape of the reflection wall 6 with each other, the LED 3 radiated into the air through the spherical lens 2
It is possible to make the light flux from the light flux into a substantially parallel light flux, or to condense or diffuse the light flux, so that an LED element suitable for the application can be obtained. The shape of the reflection wall 6 can be set freely as described above. For example, the shape of the reflection wall 6 is a conical surface 6A (left side) as shown in FIG.
Alternatively, when the parabolic shape 6B (right side) is used, the reflected light from the LED 3 is guided to the spherical lens 2 through the reflection wall 6A or 6B, and the LED 3 and the spherical center of the spherical lens 2 are connected to each other as indicated by the arrow. The number of light components traveling along the optical axis connecting the two is increased, and the effect of strengthening the output light from the LED 3 can be obtained with respect to the visual field from this direction.

The feature of the present embodiment is that, as described above, the design of the LED unit 1 with a lens can be freely selected and collected, and the spherical lens 2 can be manufactured as a sphere having a high sphericity. It is to make the positioning and attachment of the ball lens 2 extremely easy in the process of producing the attached LED unit 1. That is, when mounting the ball lens 2
Is positioned by the opening end of the reflection wall 6 in a free posture, so that its optical axis can be held in a predetermined direction.

Next, an embodiment according to the second mode of the present invention will be described with reference to the following drawings.

FIG. 3 shows a configuration according to the embodiment. Here, 12 is a hemispherical plano-convex lens according to the present embodiment. The plano-convex lens 12 is formed of a heat-resistant transparent resin such as glass or polyether sulfone or Arton so as to obtain a predetermined radius r.
In the case of this example, the plano-convex lens 12 is formed in a slightly larger eye than a hemisphere. 12A is the flat surface of the LED
The light from 3 enters the plano-convex lens 12 from this flat surface 12A via the transparent region 7. The plano-convex lens 12
Is made of, for example, a translucent epoxy resin filled in the translucent region 7 so that the outer peripheral edge portion of the flat surface 12A is the reflector portion 4A.
The lens positioning frame 8 is joined to the upper surface 4B of the above in a contact state, and 8 is provided at the target position of the peripheral portion or the four corners of the reflector portion 4A. It is desirable that the lens positioning frame 8 is integrally molded when the support 4 including the reflector portion 4A is molded with resin, and the inside of the lens positioning frame 8 is molded according to the shape of the lens 12.

FIG. 4 shows another embodiment according to the second embodiment. In this embodiment, the lens positioning frame 8 is attached to the reflector upper surface 4B.
It is the same as the above embodiment except that it is provided at the target positions of the four corners. According to an embodiment according to the second aspect of the invention,
The distance R from the lens center 0 to the LED 3 is the plano-convex lens 12
Can be set regardless of the radius r of. In addition,
The plano-convex lens 12 does not necessarily have to be larger than the hemisphere, and can be a hemisphere or a lens having a thickness smaller than that of the hemisphere. The degree of freedom in selection of the shape of the reflection wall 6 and the like can be increased as compared with the case of the first embodiment.

FIG. 5 shows still another embodiment according to the second aspect of the present invention. As shown in FIG. 5, the lens 22 according to the present embodiment has a lens portion 22A functioning as a condenser lens and a flange portion 22B for fixing the lens portion 22A to the reflector portion upper surface 4B of the support body 4 in an integrated form. It is made of heat-resistant transparent resin. 22C is a flange portion 22
It is the positioning hole of B previously drilled. By fitting the pin portion 4C protruding from the reflector portion upper surface 4B into the positioning hole 22C when the lens 12 is bonded and fixed, the lens 22 can be accurately and easily fixed to the support body 4. However, the positioning hole 22C and the pin portion 4C
It may be a positioning means that does not depend on fitting with. Reference numeral 9 shown in FIG. 5C is a relief groove for releasing the adhesive resin overflowing from the light transmitting area 7 when the lens 22 is fixed, and the lens base of the lens 22 is solidified by the resin overflowing the escape groove 9. The portion 22B can be bonded to the support 4 more firmly and securely.

According to this embodiment, the shape of the minute lens 22 can be made uniform by a molding die, and the shape of the lens portion 22A can be freely set according to the light condensing and the light scattering. It becomes possible.

In the above-mentioned embodiments, the lens is mainly provided to collect light.
The relative position between the lens and the LED and the shape of the reflective wall surface are freely set so that the light flux has directivity within a limited range, such as limiting the angle of scattering according to the usage state of the LED element. That is, the common advantages of the respective configurations can be obtained.

[0020]

As described above, according to the present invention, a light emitting diode held by a lead frame, a unit base holding the lead frame, and an annular lens whose one end side is joined to the unit base. It is surrounded by a support body, a reflection wall portion that surrounds the light emitting diode in the center of the lens support body and reflects light emitted from the light emitting diode, and the reflection wall portion and the unit base. By providing a condenser lens arranged on the other end side of the lens support so as to block the light-transmitting region and a lens fixing means for fixing the condenser lens to the lens support, it is possible to condense light. It is possible to freely set the related light distribution and create it for the purpose of use, and it is possible to enhance the stable focusing property around the optical axis, and the assembly is easy and inexpensive. It is possible to elephants.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration example according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing an example of a refraction path of light according to the first embodiment of the present invention by a cross section.

FIG. 3 is a sectional view showing a configuration example according to a second mode of the present invention.

FIG. 4 is a perspective view showing another configuration example in which a lens and a support are separated according to a second embodiment of the present invention.

FIG. 5 is an explanatory view showing still another configuration example according to the second mode of the present invention by a top view (A), a side view (B) and a sectional view (C) taken along the line AA in (A).

[Explanation of symbols]

0 ball center 1 light emitting diode (LED) unit 2 ball lens 3 LED 4 support 4A reflector part 4B upper surface 4C pin part 5 lead frame 6, 6A, 6B reflective wall 7 light transmissive area 8 lens positioning frame 12 hemispherical plano-convex lens 12A Flat surface (mounting surface) 22 (Molding) Lens 22A Lens part 22B Flange part 22C Positioning hole n _R , n _C Refractive index

Claims (10)

[Claims] 1. A light emitting diode held by a lead frame, a unit base holding the lead frame, an annular lens support having one end side joined to the unit base, and a central part of the lens support. A reflective wall portion surrounding the light emitting diode and configured to reflect light emitted from the light emitting diode; and a lens support member other than the lens support member so as to close a light transmissive region surrounded by the reflective wall portion and the unit base. A light emitting diode unit, comprising: a condenser lens disposed on an end side, and a lens fixing means for fixing the condenser lens to the lens support. 2. The light emitting diode unit according to claim 1, wherein the lead frame, the unit base, and the lens support are integrally molded. 3. The light emitting diode unit according to claim 1, wherein the lens fixing means is a translucent adhesive resin filled in the translucent region. 4. The light emission according to claim 1, wherein the lens support is made of an opaque white resin in which a wall surface of the reflection wall portion is mirror-finished. Diode unit. 5. The light emitting diode unit according to claim 1, wherein the condenser lens is a spherical lens. 6. The light emitting diode unit according to claim 1, wherein the condenser lens is a plano-convex lens. 7. The light emitting diode unit according to claim 1, wherein the reflection wall portion has a larger diameter toward the condenser lens side. 8. The light emitting diode unit according to claim 1, further comprising positioning means for positioning the condenser lens on the other end surface of the lens support. 9. The light emitting diode unit according to claim 6, wherein a flange portion is formed on the outer periphery of the plano-convex lens. 10. The light emitted from the plano-convex lens is determined by a combination of the convex surface shape and refractive index of the plano-convex lens, the distance from the light emitting diode to the flat surface of the plano-convex lens, and the refractive index of the translucent region. The light emitting diode unit according to any one of claims 6 to 9, wherein the light emitting diode unit is set so as to be able to be collected and dispersed.