JPH11266035A - Light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-luminance and highly reliable light source device, which emits almost parallel rays. SOLUTION: A plurality of LED elements 14 are formed on the surface on one side of the surfaces of a translucent substrate 12, and a metal plate 18 is arranged on the side of the surface on one side of the surfaces of the substrate 12. The plate 18 has concave mirrors 22, which are formed at the positions where they correspond to the elements 14 in the plate 18 and spaces, which are formed by the substrate 12 and the mirrors 22 are filled with each transparent resin 16. Lightsemitted from the surface sides of the elements 14 are turned into almost parallel rays by the mirrors 22, and the parallel rays are transmitted the substrate 12 and are emitted. Moreover, heat generated in the elements 14 is transferred to the plate 18 and is dissipated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device,
In particular, it relates to a light source device using, for example, a light emitting element.

[0002]

2. Description of the Related Art In recent years, with the spread of liquid crystal display panels, it has become particularly important to flatten and collimate light sources, and LED elements have been used in place of halogen lamps which have conventionally been generally used as light sources for image display. Attention has been paid to flat light sources.

However, in order to put the LED element into practical use as an image display light source, it is necessary to improve the luminance and to make the emitted light parallel. As a parallel light source device that emits parallel light as a light source using an LED element, for example, there is a device using a reflecting mirror (JP-A-9-90355). As shown in the schematic cross-sectional view of FIG.
, LED 3, and a transparent member 4. The LED 3 includes a lead frame 5, a reflecting mirror 6, an LED element 7, and a transparent resin 8. Here, the LED 3 is connected to the substrate 2 by the lead frame 5. LED3
Is a device in which an LED element 7 is fixed near the focal point of a reflecting mirror 6 with a transparent resin 8. In this structure, light emitted from the LED element 7 is reflected by the reflecting mirror 6 to become substantially parallel light, and emitted from the transparent member 4.

As described above, as a conventional parallel light source device using an LED element, an LED including a reflecting mirror or the like individually is used.
Are arranged in parallel on a substrate or the like to provide a parallel light source device.

[0005]

However, in the above-mentioned prior art, although the emitted light can be made parallel, it is difficult to obtain practically sufficient luminance. That is, to improve the luminance, it is necessary to increase the mounting density of the LED elements. However, in the above-described conventional technology, since the individually formed LEDs are arranged in parallel to form a parallel light source device,
There is a problem that the density is limited by the size of the LED. For example, in the parallel light source device 1 of FIG. 12, since the size of the LED 3 is limited by the processing limit of the lead frame 5 and the reflecting mirror 6, etc., the size of the LED 3 cannot be reduced to a certain limit or more.
The mounting density of the D element 7 could not be increased. Therefore, in the related art, there is a problem that it is difficult to obtain sufficient luminance in the parallel light source device using the LED.

On the other hand, since the heat generated by the LED element is lower than that of a halogen lamp or the like, the problem does not matter when the mounting density of the LED element is low, but the heat generated by the LED element increases when the mounting density is increased. As a result, the light emission intensity and the life of the LED element decrease.

Therefore, when the luminance of the light source is improved by increasing the mounting density of the LED elements, if the heat generated by the LED elements cannot be effectively radiated at the same time, the luminance and the reliability of the light source are reduced. There was a problem of lowering.

Therefore, a main object of the present invention is to provide a light source device which emits substantially parallel light and has high luminance and high reliability.

[0009]

According to a first aspect of the present invention, there is provided a light source device using a light emitting element, comprising: a light transmitting substrate; A plurality of light emitting elements disposed on the main surface, a first parallel light converting means disposed on one main surface side of the light transmissive substrate and substantially collimating light emitted from the light emitting element, and a light transmitting substrate And a radiator for radiating heat generated from the light emitting element.

According to a second aspect of the present invention, in the light source device according to the first aspect, the heat radiating means includes a metal plate having a concave mirror formed at a position corresponding to each of the light emitting elements; The optical means is a concave mirror.

According to a third aspect of the present invention, in the light source device according to the first aspect, the heat radiating means includes a molding resin and a heat radiating plate formed on a part of the molding resin.
A recess is provided at a position corresponding to each of the light emitting elements,
The parallel light converting means is a concave mirror formed on the concave portion.

According to a fourth aspect of the present invention, in the light source device according to any one of the first to third aspects, a space formed by the translucent substrate and the concave mirror is filled with a transparent resin. It is characterized by.

According to a fifth aspect of the present invention, in the light source device of the second aspect, a space formed by the translucent substrate and the concave mirror is filled with a transparent resin, and the metal plate is entirely And a groove formed so as to enclose the concave mirror in a lump.

According to a sixth aspect of the present invention, in the light source device of the third aspect, a space formed by the translucent substrate and the concave mirror is filled with a transparent resin, and the molding resin is entirely And a groove formed so as to enclose the concave mirror in a lump.

A light source device according to a seventh aspect is the light source device according to any one of the first to sixth aspects, further comprising a plurality of light emitting elements on the other main surface of the light transmitting substrate, wherein the plurality of light emitting elements are Each is characterized by being molded with a substantially hemispherical transparent resin.

According to an eighth aspect of the present invention, in the light source device according to any one of the first to sixth aspects, a microlens array for condensing outgoing light on the other main surface side of the transparent substrate. Is further included.

According to a ninth aspect of the present invention, in the light source device according to any one of the first to sixth aspects, a light source for converting the emitted light into substantially parallel light is provided on the other main surface side of the light-transmitting substrate. It is characterized by further including a two-parallel light converting means.

According to a tenth aspect of the present invention, there is provided a light source device according to the ninth aspect.
In the light source device described in (1), the second collimating means includes a plurality of Fresnel lenses arranged so as to correspond to each of the light emitting elements.

The light source device according to the eleventh aspect is the ninth aspect.
In the light source device described in (1), the second collimating unit includes a plurality of ball lenses arranged so as to correspond to each of the light emitting elements.

In the light source device according to the first aspect, the light emitted from the light emitting element is substantially collimated by the first collimating means, and the heat generated from the light emitting element is radiated by the heat radiating means. Further, since the light-emitting element is directly provided on the light-transmitting substrate, the light-emitting element can be mounted at high density. Therefore, in the light source device according to the first aspect, a light source device that emits substantially parallel light and has high luminance and high reliability can be obtained.

In the light source device according to the second aspect, since the heat generated in the light emitting element is quickly released by the metal plate disposed on one main surface of the translucent substrate, a high density is provided on the transparent substrate. Even when the light emitting element is formed by using the method described above, the temperature of the light emitting element can be prevented from becoming high. Light emitted from the light emitting element is converted into substantially parallel light by a concave mirror provided on the metal plate. Therefore, a light source device that emits parallel light and has high luminance and high reliability can be obtained.

In the light source device according to the third aspect, the heat generated in the light emitting element is quickly released by the molding resin and the heat radiating plate disposed on one main surface side of the light transmitting substrate. Therefore, even when the light-emitting elements are formed at a high density, the temperature of the light-emitting elements can be prevented from becoming high. Light emitted from the light emitting element is converted into substantially parallel light by a concave mirror formed on the concave portion of the molding resin. Therefore, a light source device that emits parallel light and has high luminance and high reliability can be obtained.

In the light source device according to the fourth aspect, since the light emitting element is covered with the transparent resin, heat generated in the light emitting element is quickly transmitted to the heat radiating means.

In this light source device, since the refractive index of the transparent resin is larger than that of air, the difference in the refractive index between the light emitting element and its surroundings is reduced. Therefore, reflection at the light emitting element interface is reduced, and more light can be extracted from the light emitting element. Therefore, a light source device with high luminance and high reliability can be obtained.

In the light source device according to the fifth aspect, in manufacturing the light source device, when the light emitting element is molded with the transparent resin, bubbles in the transparent resin material are discharged through the groove of the metal plate. . Therefore, it is possible to prevent air bubbles from being mixed into the transparent resin, to prevent a decrease in luminance due to irregular reflection by the air bubbles, and to prevent a decrease in heat dissipation due to the air bubbles.

In the light source device according to the sixth aspect, the light source device according to the fifth aspect
As in the light source device described in (1), air bubbles can be prevented from being mixed into the transparent resin.

In the light source device according to the seventh aspect, since the light emitting elements are arranged on both the one main surface and the other main surface of the light transmitting substrate, the number of the light emitting elements can be approximately doubled. Therefore, a light source device with higher luminance can be obtained.

In the light source device according to the eighth aspect, the light that has been made substantially parallel by the concave mirror exists on the other main surface side of the light-transmitting substrate (the side on which the first parallel light means is not formed). The light is converged to a predetermined focal point by the micro lens. Therefore, it is useful as a light source for a projection type liquid crystal display device.

[0029] In the light source device according to the ninth aspect, the light emitted from the light emitting element is emitted by the first collimating means and the second collimating means existing on the other main surface side of the light transmitting substrate. It becomes parallel light. Therefore, a light source device that can make the emitted light more parallel can be obtained.

In the light source device according to the tenth aspect, the light emitted from the light emitting element is made substantially parallel by the concave mirror and the Fresnel lens.

In the light source device according to the eleventh aspect, the light emitted from the light emitting element is made substantially parallel by the concave mirror and the ball lens.

[0032]

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

This embodiment is used as a reflection type flat light source device using a metal plate on which a concave mirror is formed as parallel light converting means and heat radiating means.

Referring to the schematic sectional view of FIG. 1A, a light source device 10 according to an embodiment of the present invention
And a plurality of LED elements 14 bonded to the translucent substrate 12 with a transparent resin (not shown), the transparent resin 16, and the metal plate 1.
8 is provided. The transparent resin 16 is formed so as to fill a space formed by the translucent substrate 12 and the concave mirror 22, and covers the LED element 14, and is made of, for example, epoxy resin.

Here, the light-transmitting substrate 12 is made of a transparent insulator such as glass, and one main surface of the light-transmitting substrate 12 to which the LED element 14 is adhered has an electric drive for driving the LED element 14. Circuits 24a and 24b (see FIG. 1B) are formed. The electric circuits 24 a and 24 b are electrically connected to the LED elements 14 by wires 20.

As the LED element 14, a red LED, a blue LED, a green LED or the like is used according to the purpose. The structure of the LED element 14 may be any,
The LED element 14 described in this embodiment has both a p-side electrode and an n-side electrode on the front side of the LED element 14 (the side to which the wire 20 is connected), and uses a transparent substrate such as sapphire as the substrate. Things. Therefore, light is emitted from the LED element 14 in all directions.

The metal plate 18 has a concave mirror 22 at a portion corresponding to the LED element 14. In order to quickly dissipate the heat generated by the LED element 14, it is desirable to use aluminum, copper, or the like having good thermal conductivity for the metal plate 18.

The concave mirror 22 has, for example, a focal point of LE
It is formed in a parabolic shape so as to be located at the D element 14.

In general, when all light emitted from a point light source is made parallel by a concave mirror, the concave mirror may be arranged so that the focal point of the concave mirror is located at the point light source.
Since the LED element 14 is a surface light emitting element, it is impossible to convert all light into parallel light. Therefore, the concave mirror 22
Has the shape of LE which emits light by surface emission and has a light distribution characteristic.
It is preferable to form in consideration of the characteristics of the D element 14.
For example, as the concave mirror 22, a mirror in which a plurality of minute concave mirrors are arranged on a parabolic curved surface may be used. In this case, by optimizing the focus of each of the minute concave mirrors, it is possible to further promote the collimation of the emitted light.

FIG. 1B is a plan view of the light source device 10. As shown in FIG. 1B, the LED element 14 is located on the normal to the curved bottom of the concave mirror 22.

Here, the size of the LED element 14 is, for example, 0.3 mm square, and the distance between adjacent LED elements 14 is, for example, 2.5 mm.

An example of a method for manufacturing the light source device 10 will be described with reference to FIG.

First, as shown in FIG. 2A, the back side of the LED element 14 (the side to which the wire 20 is not connected) is adhered to the translucent substrate 12 with a transparent resin.
The upper electric circuits 24a and 24b (see FIG. 1B) are electrically connected to the LED elements 14 by wires 20.

Next, as shown in FIG.
After the transparent resin material 16a is dropped on the metal plate 18 on which the LED 2 is formed so as to fill the concave mirror 22, the light-transmitting substrate 12 to which the LED elements 14 are adhered is removed from above the metal plate 18.
It is fixed on the metal plate 18 until the transparent resin material 16a is hardened. At this time, the extra transparent resin material 16a flows out from between the translucent substrate 12 and the metal plate 18.

It is necessary to prevent the electric circuits 24a and 24b formed on the light-transmitting substrate 12 from being short-circuited to the metal plate 18, but the electric circuits 24a and 24b must be covered with an insulator or The light-transmitting substrate 1 is mounted so that the electric circuits 24a and 24b do not adhere to the metal plate 18.
A spacer or the like may be interposed between the metal plate 2 and the metal plate 18.

Then, the light source device 10 is formed as shown in FIG.

The function of the concave mirror 22 of the light source device 10 is shown in FIG.
Is shown schematically in FIG. As shown in FIG. 3, the light emitted from the front surface side of the LED element 14 is reflected by the concave mirror 22 and becomes substantially parallel light, and is emitted from the translucent substrate 12 to the side where the LED element 14 is not formed. Is done. Therefore, in the light source device 10, light emitted from the surface side of the LED element 14 can be effectively used as parallel light.

Since the LED element 14 is bonded to the translucent substrate 12 by a transparent resin (not shown),
As shown in FIG. 3, the light emitted from the back surface side of the LED element 14 is transmitted through the light transmitting substrate 12 and emitted. Therefore, in the light source device 10, the LED which has been conventionally inefficient
Light emitted from the back surface of the element 14 can also be used effectively.

Further, in the light source device 10, unlike the case of arranging resin-molded LEDs as in the prior art, the LE
Since the D element 14 is directly bonded to the translucent substrate 12, it is possible to mount the LED element 14 at a higher density,
Brightness can be improved by improving the mounting density.

Further, since the LED element 14 is covered with the transparent resin 16 and the refractive index of the transparent resin 16 is larger than that of air, the difference in the refractive index between the LED element 14 and its surroundings is reduced. Therefore, the reflection of light at the interface of the LED element 14 decreases, and the amount of light that can be extracted from the LED element 14 increases.

As described above, according to the light source device 10,
A light source device with higher luminance than before can be obtained. As an example,
In the light source device 10, the LED elements 14 are arranged on the transparent substrate 12 at an interval of 2.5 mm (80 in 8 columns and 10 rows) to emit light (drive current: 20 mA).
In this case, the luminance of the central portion immediately above the light-emitting side of the light-transmitting substrate 12 is 22,000 lux when the red LED element is used as the LED element 14, and 110,000 lux when the green LED element is used. Lux and 32,000 lux when a blue LED element was used.

Further, according to the light source device 10, since the heat generated by the LED element 14 can be quickly released, a light source device with high luminance and high reliability can be obtained. That is, the heat generated in the LED element 14 is transmitted to the metal plate 18 via the transparent resin 16 and is radiated from the metal plate 18 to the atmosphere, so that it is possible to prevent the LED element 14 from becoming too hot. . Further, by adding a heat radiation promoting means such as a heat radiation fin or a heat radiation fan to the metal plate 18, it is possible to further prevent the temperature of the LED element 14 from rising.

For example, in the above embodiment, when radiating fins are attached to the metal plate 18 and the radiating fins are immersed in a cooling solution for increasing the heat storage capacity, the LED elements 14 are arranged on the transparent substrate 12 at 2.5 mm intervals. Blue L which consumes the most power by arranging (80 columns in 8 columns and 10 columns)
Emit ED element (drive voltage 3.84V, drive current 20m)
In the case of A), the surface temperature of the translucent substrate 12 was approximately 60 ° C., and was substantially constant in balance with the temperature of the cooling solution. On the other hand, unlike the above embodiment, the LED element 1
When the light-emitting device 4 is disposed on the translucent substrate 12 and emits light without forming a heat radiating means (the state shown in FIG. 2A), the surface temperature of the translucent substrate 12 exceeds 100 ° C. within one minute. As a result, the light emission intensity and life of the LED element 14 were significantly reduced.

In the above embodiment, a metal plate having a concave mirror is used as the parallel light converting means and the heat radiating means. However, a concave portion is formed in a metal or ceramics having high thermal conductivity, and light is reflected on the concave portion. A mirror having a concave mirror formed by forming a metal thin film made of silver, aluminum, or the like with high efficiency may be used.

The light source device 10 shown in FIG. 1 schematically shows an example of this embodiment.
The number and arrangement of the elements 14 can be arbitrarily set according to the purpose (the same applies to the following embodiments).

For example, FIG. 4 shows LEs of 8 columns and 10 columns.
An example of the shape of the metal plate 18 when forming the D element 14 is shown. The metal plate 18 shown in FIG. 4 includes a concave mirror 22 formed at a position corresponding to the LED element 14 and all the concave mirrors 2.
A groove 26 formed so as to enclose the light-transmitting substrate 2 at a time, and a light-transmitting substrate fixing surface 28 that supports the light-transmitting substrate 12 in three directions. In this metal plate 18, the transparent substrate fixing surface 28
Is provided at a position higher than the surface on which the concave mirror 22 is formed, thereby preventing the electric circuits 24 a and 24 b formed on the translucent substrate 12 from contacting the metal plate 18 and short-circuiting. it can. In the manufacturing process of the light source device 10 shown in FIG.
When fixing the transparent resin material 16 to the metal plate 18, the transparent resin material 16 a dropped more than the design gap and the bubbles existing in the transparent resin material 16 a can be easily discharged by the groove 26, and the bubbles are mixed into the transparent resin 16. Can be prevented.

The arrangement of the LED elements 14 may be a close-packed arrangement so as to be adjacent in six directions. In this case, the arrangement of the concave mirrors 22 is as shown in FIG. 5, and the LED elements 14 are arranged on the normal line of the curved bottom of each concave mirror 22.

Referring to FIG. 6, another embodiment of the present invention will be described.

The light source device 30 of this embodiment can achieve the same technical effects as those of the light source device 10 shown in FIG. 1 and is easy to manufacture.

Referring to the schematic cross-sectional view of FIG. 6A, the light source device 30 of this embodiment is bonded to the light-transmitting substrate 12 with a transparent resin (not shown). A plurality of LED elements 14, a transparent resin 16, a metal thin film 32,
A molding resin and a heat radiating plate formed on one main surface of the molding resin are provided. Electric circuits 24a and 24b (see FIG. 1B) for driving the LED element 14 are formed on the translucent substrate 12, and the LED element 14 and the electric circuit are electrically connected by wires 20. ing.

The molding resin 34 has a concave portion 38 at a position corresponding to each of the LED elements 14.

The metal thin film 32 is made of a metal having a high light reflectance such as aluminum or silver.
Functions as a concave mirror 40. The shape of the concave mirror 40 is the same as that of the concave mirror 22 of the light source device 10. The transparent resin 16 is formed so as to fill a space formed by the translucent substrate 12 and the concave mirror 40, and covers the LED element 14.

The heat radiating plate 36 may be made of any metal or ceramic having good heat conductivity, and is particularly preferably a metal such as aluminum or copper.

With reference to FIGS. 6B and 6C, an example of a method for manufacturing the light source device 30 will be described.

First, as shown in FIG. 6B, a metal thin film 32 is formed on a molding resin 34 having a concave portion 38 on one main surface and a heat radiating plate 36 formed on the other main surface. here,
The concave portion 38 can be easily formed by pressing a mold having a convex portion when the molding resin 34 is cured. Further, the metal thin film 32 can be easily formed by a vapor deposition method or a plating method.

Next, as shown in FIG.
0, the transparent resin material 16a is dropped on the metal thin film 32, and the light-transmitting substrate 12 to which the LED elements 14 are adhered is fixed from above to fix the transparent resin material 16a. Can be formed. Here, the translucent substrate 12 to which the LED 14 is adhered is
Since this is the same as that described with reference to FIG. 2, duplicate description will be omitted.

In the light source device 30, the same technical effects as those of the light source device 10 shown in FIG. 1 can be obtained, and the light source device 30 can be easily manufactured.

That is, in the light source device 10, the metal plate 18
Of these, the concave mirror 22 must be formed by processing metal, whereas the light source device 30 has a concave mirror 40
Can be easily formed by depositing or plating the metal thin film 32 on the molding resin 34 in which the concave portion 38 is formed. Therefore, productivity can be improved and manufacturing cost can be reduced.

In the light source device 30, the LED element 14
Is conducted to the heat radiating plate 36 through the transparent resin 16 and the molding resin 34 and is radiated. Therefore, it is preferable that the thermal conductivity of the molding resin 34 is higher, and it is more preferable to mix a metal filler or a ceramics filler for improving the thermal conductivity into the molding resin 34.

Referring to FIG. 7, another embodiment of the present invention will be described.

The light source device 50 of this embodiment can achieve the same technical effects as those of the light source device 10 shown in FIG. 1 and is easy to manufacture.

Referring to the schematic cross-sectional view of FIG. 7A, the light source device 50 includes a light-transmitting substrate 12 and a plurality of LED elements bonded to the light-transmitting substrate 12 with a transparent resin (not shown). 14
, Transparent resin 16, metal thin film 52, molding resin 54
And a radiator plate 56.

Electric circuits 24a and 24b (FIG. 1 (b)) for driving the LED elements 14 are provided on the transparent substrate 12.
LED element 14 and the electric circuit 2
4a and 24b are electrically connected by a wire 20.

The metal thin film 52 is made of a metal having a high light reflectance such as aluminum or silver, and a portion facing the transparent resin 16 functions as a concave mirror 58. And the concave mirror 58
Is the same as that of the concave mirror 22 of the light source device 10. Further, the transparent resin 16 is formed so as to fill a space formed by the translucent substrate 12 and the concave mirror 58, and
The D element 14 is covered.

The heat radiating plate 56 has a concave portion 59 and is made of a metal such as copper or aluminum, ceramics, or the like having good heat conductivity.

With reference to FIGS. 7B and 7C, an example of a method for manufacturing the light source device 50 will be described.

First, as shown in FIG. 7B, a transparent resin 16 in the form of a plano-convex lens is formed so as to surround the LED element 14 adhered to the light-transmitting substrate 12.
A metal thin film 52 is formed on the transparent resin 16 and above. Here, as a method of forming the plano-convex lens-shaped transparent resin 16 so as to surround the LED element 14, for example, FIG.
In the manufacturing process of the light source device 10 shown in FIG.
After the hardening of the metal plate 6, the metal plate 18 may be peeled off from the transparent substrate 12 and the transparent resin 16. The metal thin film 52
Can be easily formed by a vapor deposition method or a plating method.

Thereafter, as shown in FIG. 7C, a molding resin material 54a is dropped so as to fill the concave portion 59 of the heat sink 56, and the light transmitting material shown in FIG. The substrate 12 is fixed until the molding resin material 54a is cured.

Thus, the light source device 50 is obtained.

As in the case of the light source device 30 shown in FIG.
The light source device 50 shown in FIG.
The same technical effects as described above can be obtained, and the production can be facilitated. That is, in the light source device 50,
The concave mirror 58 can be easily formed.

In the light source device 50, as in the light source device 30, it is more preferable to mix a metal filler or a ceramic filler for improving the thermal conductivity into the molding resin 54.

Referring to FIG. 8, another embodiment of the present invention will be described.

The light source device 60 of this embodiment can obtain a particularly high luminance.

Referring to the schematic cross-sectional view of FIG. 8A, light source device 60 is a transparent substrate 1 of light source device 10 shown in FIG.
2, a plurality of LED elements 62 and a masking pattern 6 formed in a portion except for the vicinity of the LED elements 62.
4 and a transparent resin 66 formed in a substantially hemispherical shape so as to cover the LED element 62. Here, on one main surface of the translucent substrate 12 where the LED elements 62 are formed,
An electric circuit (not shown) is formed similarly to the other main surface (see FIG. 1B), and the LED element 62 and the electric circuit are electrically connected by a wire 68. The LED element 62 is disposed at a position facing the LED element 14 with the translucent substrate 12 interposed therebetween.

As a method of forming the light source device 60, for example, first, after forming the light source device 10 of FIG. 1, an electric circuit pattern is formed on the light-transmitting substrate 12 (not shown), and thereafter, Except for the part that forms the resin 66,
A masking pattern 64 is formed on the translucent substrate 12. Here, the masking pattern 64 includes the transparent resin 6.
When a material having no affinity with the epoxy resin 6 is used, for example, when an epoxy resin is used as the transparent resin 66, a silicone-based material having no affinity with the epoxy resin is used.

Next, the LED element 62 is bonded with a transparent resin (not shown) at a position facing the LED element 14 with the light transmitting substrate 12 interposed therebetween, and the LED element 62 and the electric circuit on the light transmitting substrate 12 are bonded. Are electrically connected by a wire 68.

Thereafter, the transparent resin 6 is placed on each LED element 62.
6 by individually dropping and curing the material of No. 6
A transparent resin 66 is formed so as to cover the ED element 62. Here, since a material having no affinity with the transparent resin material is used for the masking pattern 64, the masking pattern 6
4 prevents the transparent resin material from flowing out, and a substantially hemispherical transparent resin 66 as shown in FIG. 8A is formed.

Thus, the light source device 60 is formed.

In the light source device 60, as shown in FIG. 8B, light emitted from the front side of the LED element 14 is made substantially parallel by the concave mirror 22, and emitted from the back side of the LED element 14. The light is made substantially parallel by the transparent resin 66. The light emitted from the surface side of the LED element 68 is made substantially parallel by the transparent resin 66,
The light emitted from the back side of the element 68 is converted into substantially parallel light by the concave mirror 22.

According to the light source device 60 of this embodiment,
Since the LED elements 14 and 62 are formed on both surfaces of the translucent substrate 12, respectively, the mounting density of the LED elements per unit area can be approximately doubled, and a high-luminance light source device can be obtained. it can. Further, the heat generated by the LED elements 14 and 62 is quickly conducted to the metal plate 18 via the translucent substrate 12 and the transparent resin 16,
Since the heat is dissipated, the temperature of the LED elements 14 and 62 can be prevented from becoming high, and a light source device with high luminance and high reliability can be obtained.

In the above embodiment, the LED element 62
Is formed at a position facing the LED element 14 with the translucent substrate 12 interposed therebetween, but the LED element 62 can be formed at an arbitrary position on the translucent substrate 12.

In the embodiment of FIG. 8A, when only the masking pattern 64 and the transparent resin 66 are formed without bonding the LED element 62,
The light emitted from the front side of the element 14 is made substantially parallel by the concave mirror 22, and the light emitted from the back side of the LED element 14 is made substantially parallel by the transparent resin 66. Accordingly, the light source device 10 has the same brightness as the light source device 10 and
It becomes possible to make outgoing light into parallel light.

Referring to FIG. 9, another embodiment of the present invention will be described.

The light source device 70 of this embodiment enables the emitted light to be made more parallel.

Referring to the schematic cross-sectional view of FIG.
0 includes the light source device 10 shown in FIG. 1 and the Fresnel lens array 72 arranged on the light emission side of the light source device 10,
In the Fresnel lens array 72, a Fresnel lens 74 having the center position on the vertical line of the LED element 14 is formed corresponding to each LED element 14.

In the light source device 10 shown in FIG. 1, a light source device with high luminance and high reliability can be obtained.
However, since it is a surface light emitting element, it is difficult to make all the light emitted from the LED element 14 parallel only by the concave mirror 22. Light emitted from the back surface of the LED element 14 is emitted without being made parallel. On the other hand, FIG.
By combining the concave mirror 22 and the Fresnel lens 74, the light source device 70 shown in FIG.

Therefore, according to the light source device 70, a light source device having high luminance and high reliability as well as the light source device 10 and capable of making outgoing light more parallel can be obtained.

Referring to FIG. 10, another embodiment of the present invention will be described.

The light source device 80 of this embodiment enables the emitted light to be made more parallel.

Referring to the schematic cross-sectional view of FIG. 10A, light source device 80 includes light source device 10 and light source device 1 shown in FIG.
And a ball lens array 82 disposed on the light emitting side of the lens array 0. The ball lens array 82 has a ball lens 84 fixed by a support frame 86. Here, in the light source device 80, the concave mirror 22 of the metal plate 18 is formed in a substantially hemispherical shape. The ball lens 84 is fixed on a vertical line of the LED element 14 by a support frame 86 so that the focal point is located near the LED element 14.

The function of the light source device 80 is shown in FIG.
Is shown schematically in FIG.

As shown in FIG. 10B, the light source device 80
In this case, the light emitted from the front surface side of the LED element 14 is reflected by the concave mirror 22, passes through the vicinity of the LED element 14, and enters the ball lens 84, so that the light is substantially collimated. The light emitted from the back surface side of the LED element 14 is also made substantially parallel by the ball lens 84 and emitted.

Therefore, according to the light source device 80, a light source device having high luminance, high reliability, and high parallelism of emitted light can be obtained.

In the above embodiment, the case where a ball lens is used has been described. However, another lens such as a plano-convex lens may be used instead of the ball lens.

With reference to FIG. 11, another embodiment of the present invention will be described.

The light source device 90 of this embodiment is particularly useful as a light source for a projection type liquid crystal display device.

Referring to the schematic cross-sectional view of FIG. 11A, light source device 90 includes light source device 10 and light source device 1 shown in FIG.
And a microlens array 92 disposed on the light emission side of the light-transmitting substrate 94.
And a plurality of microlenses 96 formed on one main surface of the light-transmitting substrate 94.

Referring to FIG. 11B, this light source device 9
The function of 0 will be described.

The liquid crystal display panel is useful as a flat type image display device. As shown in FIG. 11B, the liquid crystal display panel 98 is composed of a pixel 100 and a black matrix 102, and has a black matrix. Matrix 102
Does not contribute to image display. Therefore, there is a problem that light incident on the black matrix 102 is wasted light.

On the other hand, in the light source device 90, the light source device 1
The substantially parallel light emitted from 0 is converged on the focal point A by the micro lens 96. Therefore, when the light source device 90 is used as a light source of the liquid crystal display device, the substantially parallel light emitted from the light source device 10 is provided by disposing the liquid crystal display panel 98 at the position of the focal point A as shown in FIG. But,
Since the light is converged on the pixel 100 by the microlens 96, loss of emitted light due to the black matrix 102 can be prevented.

Therefore, according to the light source device 90, a light source device useful as a light source for a projection type liquid crystal display device can be obtained.

According to the above embodiment, the case where the microlens 96 is formed on the light transmitting substrate 94 has been described, but the microlens 96 is formed on the light transmitting substrate 1 of the light source device 10.
2 or on the main surface of the liquid crystal display panel 98 on the light source device 90 side.

As described above, the embodiment of the present invention has been described by way of example. However, the above embodiment is merely an example when the present invention is used, and the present invention is not limited to the above embodiment.

For example, in the description of the embodiments of the light source devices 60, 70, 80, and 90, each of the light source devices 1
Although the case where 0 is provided has been described, it goes without saying that the light source device 30 or 50 may be used instead of the light source device 10.

Further, in the above-described embodiment, the case where the space formed by the transparent substrate and the concave mirror is filled with the transparent resin has been described. In this case, the heat generated by the LED element 14 is conducted to the metal plate or the heat radiating plate via the gas existing in the space formed by the transparent substrate and the concave mirror and the transparent substrate.

Further, in the above embodiment, the case where the LED element in which both the p-side electrode and the n-side electrode are formed on the element surface side is used, but either one is formed on the element surface side. And the other is LED
An LED element formed on the back side of the element may be used. In this case, since the back side electrode is electrically and physically connected to the electric circuit formed on the translucent substrate with the metal paste, no light is emitted from the back side of the LED element. Therefore, in this case, the parallel light converting means such as a concave mirror or a Fresnel lens is formed so that only light from the element surface side can be optimally converted into parallel light.

In the above embodiment, the case where the LED element is used as the light emitting element has been described. However, other light emitting elements can be used.

[0118]

As described above, according to the present invention, a light emitting element can be mounted at high density, light emitted from the light emitting element can be made substantially parallel, and a temperature rise of the light emitting element can be prevented. can do. Therefore, it is possible to obtain a light source device that emits substantially parallel light and has high luminance and high reliability.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention;

FIG. 2 is an illustrative view showing a manufacturing process of the light source device shown in FIG. 1;

FIG. 3 is an illustrative view showing a function of a concave mirror;

FIG. 4 is an illustrative view showing a shape of a metal plate in one embodiment of the present invention;

FIG. 5 is an illustrative view showing one example of an arrangement state of a concave mirror;

FIG. 6 is an illustrative view showing another embodiment of the present invention;

FIG. 7 is an illustrative view showing another embodiment of the present invention;

FIG. 8 is an illustrative view showing still another embodiment of the present invention;

FIG. 9 is an illustrative view showing another embodiment of the present invention;

FIG. 10 is an illustrative view showing another embodiment of the present invention;

FIG. 11 is an illustrative view showing still another embodiment of the present invention;

FIG. 12 is an illustrative view showing a structure of a conventional parallel light source device;

[Explanation of symbols]

10, 30, 50, 60, 70, 80, 90 Light source device 12 Translucent substrate 14, 62 LED element 16, 66 Transparent resin 18 Metal plate 20, 68 Wire 22, 40, 58 Concave mirror 26 Groove 32, 52 Metal thin film 34, 54 Molding resin 36, 56 Heat sink 38, 59 Concavity 64 Masking pattern 72 Fresnel lens array 74 Fresnel lens 82 Ball lens array 84 Ball lens 92 Micro lens array 96 Micro lens

Claims (11)

[Claims] 1. A light source device using a light-emitting element, comprising: a light-transmitting substrate; a plurality of light-emitting elements arranged on one main surface of the light-transmitting substrate; A first collimating means arranged on the main surface side for substantially collimating light emitted from the light emitting element; and a first parallel light means arranged on the one main surface side of the translucent substrate and generated from the light emitting element. A light source device comprising: heat radiating means for radiating heat. 2. The radiating means includes a metal plate having a concave mirror formed at a position corresponding to each of the light emitting elements, and the first parallel light converting means is the concave mirror. Item 2. The light source device according to item 1. 3. The heat dissipating means includes a molding resin and a heat radiating plate formed on a part of the molding resin, wherein the molding resin has a concave portion at a position corresponding to each of the light emitting elements, The light source device according to claim 1, wherein the light conversion unit is a concave mirror formed on the concave portion. 4. The light source device according to claim 1, wherein a space formed by the translucent substrate and the concave mirror is filled with a transparent resin. 5. A groove formed so that a space formed by the translucent substrate and the concave mirror is filled with a transparent resin, and wherein the metal plate surrounds all the concave mirrors collectively. The light source device according to claim 2, further comprising: 6. A groove formed so that a space formed by the translucent substrate and the concave mirror is filled with a transparent resin, and the molding resin surrounds all the concave mirrors collectively. The light source device according to claim 3, further comprising: 7. The light-emitting device according to claim 1, further comprising a plurality of light-emitting elements on the other main surface of the light-transmitting substrate, wherein each of the plurality of light-emitting elements is molded with a substantially hemispherical transparent resin. Or 6
The light source device according to any one of the above. 8. The light source device according to claim 1, further comprising a microlens array for condensing outgoing light on the other main surface side of the light-transmitting substrate. . 9. The light-transmitting substrate according to claim 1, further comprising a second parallel light converting means on the other main surface side of the light-transmitting substrate for converting the emitted light into substantially parallel light. The light source device according to item 1. 10. The light source device according to claim 9, wherein said second collimating means includes a plurality of Fresnel lenses arranged so as to correspond to each of said light emitting elements. 11. The light source device according to claim 9, wherein said second collimating means includes a plurality of ball lenses arranged corresponding to each of said light emitting elements.