JP2001007406A - LED array - Google Patents

Abstract

(57) [Abstract] [Object] The present invention can improve mass productivity when three-dimensionally arranging a plurality of reflective light emitting diodes, and achieves high uniformity and high external radiation efficiency in an irradiation area. It is an object of the present invention to provide a light emitting diode array having excellent optical characteristics. The present invention relates to a light-emitting element, a lead portion for supplying power to the light-emitting element, a concave reflection surface provided to face a light-emitting surface of the light-emitting element, and light reflected by the concave reflection surface. A plurality of reflective light-emitting diodes having a radiation surface that emits light, and a light-transmitting material that seals a part of the light emitting element and the lead portion and fills a space between the concave reflection surface and the radiation surface. A central planar substrate for mounting the reflective light emitting diode disposed in the central portion, and a reflective planar light emitting diode disposed in a portion other than the central planar substrate for mounting, At least one annular planar substrate formed and arranged so as to surround the central planar substrate, wherein the central planar substrate and the annular planar substrate are arranged on different planes. It is characterized by.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arrangement of a plurality of reflective light emitting diodes for emitting light emitted from a light emitting element after reflecting the light on a concave reflecting surface and then radiating the light to the outside. The present invention relates to an improvement in a light emitting diode array used as a light emitting diode array.

[0002]

2. Description of the Related Art In general, there is a halogen bulb as a light source used for a printer, a copier, a facsimile or the like as an optical apparatus. Recently, attention has been paid to light-emitting diodes from the viewpoint of the problem of heat rays from a light source in an optical device, the size and volume of the device, the ease of controlling the light source, or the life of the light source. Various light emitting diode arrays have been proposed as this type of light source.
This type of light-emitting diode array can make the irradiation distribution of each light-emitting diode in the irradiation area equal if the distance from the radiation surface of each light-emitting diode to the irradiation area is the same, and improve the uniformity. be able to.

[0003]

By the way, in the conventional light emitting diode array, a holder for holding the light emitting diode at a predetermined position and a flat substrate on which the light emitting diode fixed to the holder is mounted are considered. Was. However, in this method, the distance between the holder and the flat substrate increases as the distance from the center to the periphery of the holder increases. For this reason, in order to produce a light emitting diode array, various light emitting diodes having different lead lengths must be prepared.

When these light-emitting diodes are formed by a transfer molding method using a mold having the same area, a light-emitting diode having a long lead portion is required to be formed by one molding, compared to a light-emitting diode having a short lead portion. The number obtained is small. Therefore, a light emitting diode having a long lead portion is inferior in productivity, and there is a problem that the conventional light emitting diode array is not suitable for mass production. Further, when the holder is not used, there is a problem that the positional accuracy of the peripheral portion of the light emitting diode is reduced. Further, as another method, there is a method in which a light-emitting diode fixed to a holder is used for aerial wiring without using a substrate. However, this method does not reduce the productivity of the light emitting diodes, but has a problem that the wiring work is troublesome and is not suitable for mass production. Further, in the case of aerial wiring, there is a disadvantage that a hand or a tool of an operator is easily caught on the wiring to cause disconnection, and a state after connection is unstable. Note that the use of the holder not only increases the number of components but also takes time to manufacture the holder, but without the holder, there is a problem that the fixing of the light emitting diode itself becomes difficult.

The present invention has been made in view of the above, and when a plurality of reflective light emitting diodes are arranged in a three-dimensional manner, mass productivity can be improved, uniformity is high in an irradiation area, and external radiation efficiency is high. It is an object of the present invention to provide a light-emitting diode array having excellent optical characteristics such as high optical characteristics.

[0006]

The present invention provides a light emitting device,
A lead portion for supplying power to the light-emitting element, a concave reflection surface provided to face a light-emitting surface of the light-emitting element, a radiation surface for emitting light reflected by the concave reflection surface to the outside, A plurality of reflective light-emitting diodes having a light-transmitting material that seals a light-emitting element and a part of a lead portion and fills a space between the concave reflecting surface and the emitting surface; and A central flat substrate for mounting a reflective light emitting diode, and for mounting the reflective light emitting diode disposed on a portion other than the central flat substrate, the annular flat central flat substrate At least one annular planar substrate is provided so as to surround the substrate, and the central planar substrate and the annular planar substrate are arranged on different planes.
A light-emitting element; a lead portion for supplying power to the light-emitting element; a concave reflection surface provided to face the light-emitting surface of the light-emitting element; and light reflected by the concave reflection surface being radiated to the outside. A plurality of reflective light-emitting diodes, comprising: a radiating surface; a light-transmitting material that seals a part of the light emitting element and the lead portion and fills a space between the concave reflecting surface and the radiating surface; It is for mounting a reflection type light emitting diode, and comprises a plurality of annular substrates formed in an annular shape. Further, the plurality of annular planar substrates are arranged in different planar shapes, and the plurality of reflective light-emitting diodes have an emission surface whose surface is a spherically or symmetrically convex surface including a conical surface. Wherein the plurality of reflective light emitting diodes are straight lines passing through the center of the concave reflecting surface when the concave reflecting surface is viewed from the front, and have a concave shape. The end of the concave reflecting surface is cut at two planes perpendicular to a straight line perpendicular to the central axis of the reflecting surface, and the reflective light emitting diode arranged on the annular planar substrate,
It is characterized in that the concave reflecting surfaces are arranged in a ring shape so that the cut surfaces are adjacent to each other.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. 1 is a schematic front view of a light emitting diode array according to an embodiment of the present invention, FIG. 2 is a schematic sectional view of FIG. 1, FIG. 3 is a schematic enlarged view of a portion surrounded by a dashed line in FIG. FIG. 5 is a schematic front view of the reflective light emitting diode used in the light emitting diode array, FIG. 5 is a schematic side view of the reflective light emitting diode, and FIG. 6 is a schematic plan view of the reflective light emitting diode.

The light emitting diode array shown in FIGS. 1 to 3 is used, for example, as a light source for image recognition or a light source for an optical fiber, and includes a plurality of reflective light emitting diodes 10, a jig 20 for temporary holding, Central flat board 3
0, and at least one annular planar substrate 40 arranged so as to surround the central planar substrate 30. The central planar substrate 30 and the annular planar substrate 40 are arranged on different planes. In such a light-emitting diode array, a plurality of light-emitting diodes are three-dimensionally arranged so that light emitted from each light-emitting diode is focused on the same irradiation area.

As shown in FIGS. 4 to 6, the reflection type light emitting diode 10 comprises a light emitting element 12 and lead portions 14a, 1a.
4b, 14c, 14d, a bonding wire 16,
A light transmissive material 18, a concave reflecting surface 22, and a radiation surface 24;
And a lead lead-out section 26. Here, the z axis is the direction of the central axis of the concave reflecting surface, and the x and y axes are orthogonal coordinate axes on a plane including the light emitting surface of the light emitting element.

The light emitting element 12 is mounted on one end of a lead 14a, and the light emitting element 12 and the lead 14b are electrically connected by a bonding wire 16. Further, the light emitting element 12, the lead portions 14a, 14b, 1
4c, 14d and bonding wire 16
Is integrally sealed with a thermosetting light-transmitting material 18 using, for example, a transfer molding method.
For example, a transparent epoxy resin having a refractive index of 1.5 is used.

The leads 14a and 14b are connected to the light emitting element 12
Used to supply power to Central flat board 3
0 not only supplies power to the light emitting element but also leads to the light emitting diode 10.
Is fixed to the central flat substrate. The leads 14a and 14b of the light emitting diode 10 mounted on the annular planar substrates 40a to 40e also
Not only for supplying power to the light emitting diode, but also for fixing the light emitting diode to the annular planar substrate. Therefore, the leads 14a and 14b are power supply and fixing leads.

On the other hand, the lead portions 14c and 14d are different from the lead portions 14a and 14b serving as electric terminals, and have nothing to do with electric wiring. In particular, the leads 14 c and 14 d of the light emitting diode 10 mounted on the central flat substrate 30 serve to fix the light emitting diode to the central flat substrate 30. On the other hand, the annular planar substrates 40a to 40e
Lead portions 14c, 1 of the light emitting diode 10 mounted on
4d is not fixed to the annular planar substrate. That is, the lead portions 14c and 14d are unnecessary for the light emitting diode mounted on the annular planar substrate. However, in the present embodiment, by using a light emitting diode mounted on the annular planar substrate having such an unnecessary lead portion, the light emitting diode is mounted on the central planar substrate and the annular planar substrate.
A common light emitting diode can be used. Therefore, since only one type of light emitting diode needs to be manufactured, mass productivity is improved.

The concave reflecting surface 22 is formed by mirror-finishing one surface of the light transmissive material 18 by plating, metal deposition, or the like, and is formed on the side facing the light emitting surface of the light emitting element 12. Here, the concave reflecting surface is formed in a substantially paraboloid of revolution facing the light emitting surface of the light emitting element, and the center of the light emitting surface of the light emitting element is arranged at the focal point. On the other hand, the radiation surface 24 is on the back side of the light emitting element 12 and has lead portions 14a and 14b.
Is formed at a position close to. To be more precise, the surface of the light transmitting material on the back side of the light emitting element, which corresponds to the optical path diameter of the light reflected by the concave reflecting surface 22, becomes the radiation surface.
Here, the radiation surface is formed in a plane shape perpendicular to the central axis (z axis) of the concave reflection surface. That is, in the present embodiment,
So that light emitting diodes can emit parallel light,
The position of the light emitting element and the shapes of the concave reflecting surface and the emitting surface are designed.

The light emitting diode 10 is a straight line passing through the center of the concave reflecting surface when the concave reflecting surface 22 is viewed from the front, and is a straight line (for example, x-axis) orthogonal to the central axis of the reflecting surface. ) Are cut symmetrically by two planes perpendicular to (). Here, when the concave reflecting surface is viewed from the front, the ratio of the length of the concave reflecting surface after cutting to the length of the concave reflecting surface before cutting in the x-axis direction is 0.7. , The ends are cut off. In this way, the end of the concave reflecting surface is cut by arranging the concave reflecting surface in a ring shape so that the cut surfaces of the concave reflecting surface are adjacent to each other.
This is for reducing the arrangement interval of the light emitting diodes.

The lead lead-out portion 26 is provided on the concave reflection surface 2.
2 and the radiation portion 24,
a, 14b, 14c, and 14d. In the present embodiment, since the end of the concave reflection surface is cut symmetrically, the lead lead-out portions are formed above and below the concave reflection surface as shown in FIG. The radiation surface is formed so as to protrude from the lead lead-out portion.

To manufacture the light emitting diode 10, a light emitting diode is formed on a lead frame by a transfer molding method. When this transfer molding method is used, a concave reflecting surface,
The radiation surface and the lead lead-out part can be formed with high precision, and their shapes are very stable. In addition, since the concave reflecting surface and the radiating surface can be formed in a state where the lead frame is firmly held, the positional accuracy with the light emitting element can be increased. Next, unnecessary portions of the lead frame are cut, and each lead portion is bent to obtain a light emitting diode as shown in FIG.
That is, as shown in FIG. 3, each of the lead portions 14a, 14b, 14c, 1
4d is bent substantially at right angles to the concave reflecting surface 22 near the lead lead-out portion, and the leading end of each lead portion is bent inward.

In the light emitting diode having the above structure, when power is supplied to the light emitting element, the light emitting element emits light, and the light emitted from the light emitting element is reflected by the concave reflecting surface and radiated outside from the radiation surface. In particular, since the concave reflecting surface is formed substantially in the shape of a paraboloid of revolution, and the center of the light emitting surface of the light emitting element is arranged at the focal point, light passing through the radiation surface is converted into light parallel to the z-axis. Radiated outside. By emitting the light emitted from the light emitting element once to the outside after being reflected by the concave reflecting surface, the light emitting diode is characterized by high external radiation efficiency, high luminance and high luminous intensity. Moreover, since the light emitted from the light emitting element is controlled only by the concave reflecting surface, the irradiation distribution of the light emitting diode itself does not have a biased irradiation pattern, and the degree of irradiation unevenness is small, so that the uniformity can be improved. it can.

The central flat substrate 30 is for mounting a plurality of reflective light emitting diodes disposed in the central portion as shown in FIG. 2, and is formed in a circular shape as shown in FIG. You. On the other hand, annular planar substrates 40a to 40e
2 is a plan view of the central flat substrate 30 as shown in FIGS.
It is for mounting a plurality of reflection type light emitting diodes arranged in other parts, and is formed in an annular shape having different radii as shown in FIG. The annular planar substrates are arranged in different planar shapes so that the central axis thereof coincides with the central axis of the central planar substrate, and is stepped along the central axis of the central planar substrate. . Each of the annular planar substrates is connected to a reflection type light emitting diode for each wheel arranged in a ring shape. In FIGS. 2 and 3, FIG. 20 shows a jig for temporary holding, which will be finally removed as described later.

Central flat substrate 30 and annular flat substrate 4
As shown in FIGS. 2 and 3, a large number of through holes 51 and pads 52 are formed in 0 a to 40 e. The through-hole is located on the central flat substrate,
Are formed at positions corresponding to the lead portions 14a to 14d of
In the case of an annular planar substrate, it is formed at a position corresponding to the lead portions 14a and 14b of the light emitting diode. here,
The diameter of the through hole is designed to be slightly larger than the diameter of the lead. The pad is formed on the inner surface of the through hole and in the vicinity of the through hole on the substrate. Note that a circuit pattern for connecting a lead portion is formed on the surfaces of the central flat substrate and the annular flat substrate.

In order to manufacture a light emitting diode array using a plurality of reflection type light emitting diodes, first, a cream solder is applied to the central flat board and the annular flat board where through holes are formed from the front side of the board. Is applied. Next, the central planar substrate and the annular planar substrate are arranged so as to be stepwise along the central planar substrate so that a plurality of light emitting diodes are arranged three-dimensionally. At this time, the diameter of the through hole was made larger than the diameter of the lead portion of the light emitting diode, and the tip portion of the lead portion was bent inward, so that the through hole and the tip portion of the lead portion were engaged, and the Can be stably arranged on the lead portion of a predetermined light emitting diode.

Next, a soldering iron is applied from the back side of the substrate to the portion where the through-holes 51 of the central flat substrate 30 and the annular flat substrates 40a to 40e are formed, and heat is transferred to the front surface of the substrate. From these, melt the cream solder,
The lead portion of the light emitting diode arranged on the central flat substrate is soldered to the central flat substrate at the position where the through hole is formed. Here, the lead portions 14c and 14d of the light emitting diodes arranged in portions other than the central flat substrate are not fixed to the annular flat substrate. Also, the lead portions 14a,
The tip of 14b is connected to the circuit pattern. In this manner, the lead portions can be easily soldered from the back side of the substrate. Then, finally, the jig 20 is removed.
In addition, by using a simple fixing tool for fixing the position of each substrate before removing the jig, or when installing this light emitting diode array, by arranging each substrate at a predetermined interval, each light emitting diode can be predetermined. Direction.

In such a light-emitting diode array, the distance from the radiation surface of each light-emitting diode to the irradiation area can be all the same, so that the irradiation distribution of each light-emitting diode in the irradiation area can be equalized, The degree can be improved. In addition, since a plurality of light emitting diodes are densely arranged, it is possible to irradiate an irradiation area with high illuminance.

In this embodiment, the use of an annular planar substrate allows the planar substrate to be aligned with the central axis of the central planar substrate substantially along the central axis of the central planar substrate. They can be arranged in a step-like manner. For this reason, even if the same length of the lead portion is used as the reflection type light emitting diode, the lead portion of the reflection type light emitting diode arranged in a ring shape can be connected to the annular flat substrate. Therefore, since one kind of light emitting diode having the same length of the lead portion can be used, the mass production effect is increased.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the invention.

[0025]

As described above, according to the present invention,
By using an annular planar substrate, it can be arranged along the central axis so as to surround the central axis of the central planar substrate. For this reason, even if the same length of the lead portion is used as the reflection type light emitting diode, the lead portion arranged in a ring shape in a portion other than the center portion can be connected to the annular flat substrate. Therefore, it is possible to use one type of reflective light emitting diode having the same length of the lead portion,
The productivity of the reflection type light emitting diodes does not deteriorate, and the wiring work is not troublesome, so that the mass productivity of the light emitting diode array can be improved. Then, a high irradiation density is obtained in the irradiation area, and a light emitting diode array having excellent optical characteristics such as high uniformity and high external radiation efficiency is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a light-emitting diode array according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of FIG.

FIG. 3 is a schematic enlarged view of a portion surrounded by a chain line in FIG.

FIG. 4 is a schematic front view of a light emitting diode according to the present invention.

FIG. 5 is a schematic side view of FIG.

FIG. 6 is a schematic plan view of FIG.

FIG. 7 is a schematic rear view of a central flat substrate and an annular substrate according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Light emitting diode 12 Light emitting element 14a, 14b, 14c, 14d Lead part 16 Wire 18 Light transmissive material 22 Concave reflective surface 24 Radiation surface 26 Lead lead-out part 30 Central flat board 40 Ring flat board

Claims (5)

[Claims] A light-emitting element; a lead for supplying power to the light-emitting element; a concave reflection surface provided to face a light-emitting surface of the light-emitting element; and light reflected by the concave reflection surface. A plurality of reflection type light emitting diodes having a radiation surface for radiating outside and a light transmitting material for sealing a part of the light emitting element and the lead portion and filling a space between the concave reflection surface and the radiation surface; And a central flat substrate for mounting the reflective light emitting diode disposed in a central portion, and mounting the reflective light emitting diode disposed in a portion other than the central flat substrate. And at least one annular planar substrate formed in an annular shape and disposed so as to surround the central planar substrate, wherein the central planar substrate and the annular planar substrate are arranged on different planes. Is characterized by Light emitting diode array that. 2. A light emitting device, a lead for supplying power to the light emitting device, a concave reflecting surface provided to face a light emitting surface of the light emitting device, and a light reflected by the concave reflecting surface. A plurality of reflection type light emitting diodes having a radiation surface for radiating outside and a light transmitting material for sealing a part of the light emitting element and the lead portion and filling a space between the concave reflection surface and the radiation surface; A light emitting diode array for mounting the reflection type light emitting diode, comprising: a plurality of annular substrates formed in an annular shape. 3. The light emitting diode array according to claim 1, wherein the plurality of annular planar substrates are arranged in different planar shapes. 4. The plurality of reflection type light emitting diodes are arranged such that their radiation surfaces are in contact with an axially symmetric convex surface including a spherical surface or a conical surface.
4. A light emitting diode array according to any one of claims 3 to 3. 5. The plurality of reflective light emitting diodes are straight lines passing through the center of the concave reflecting surface when the concave reflecting surface is viewed from the front, and are orthogonal to the central axis of the concave reflecting surface. The end of the concave reflection surface is cut at two planes perpendicular to the straight line, and the reflection type light emitting diode arranged on the annular planar substrate has a cut surface of the concave reflection surface. 5. The light emitting diode array according to claim 1, wherein the light emitting diode array is arranged in a ring shape so as to be adjacent to each other.