JPH1039794A - White light source and led lamp using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple structural and inexpensive white light source by combining two colors of light sources of blue and yellow, lighting them and light emitting white. SOLUTION: For instance, silver palladium is pattern printed on a substrate 4, and a full wave current circuit consisting of e.g. four pieces of chip like rectifying diodes 5a-5d, six pieces of similar chip like LEDs 6a-6f light emitting the yellow and a piece of similar chip like LED 7 light emitting high luminance blue are glued to the pattern printed part by using e.g. conductive paste, and its upper part is covered by a resin seal 8 of light transmissible material. Then, a current is supplied to respective LEDs 7, 6a-6f through the full wave current circuit. That is, by combining two colors of light sources of blue and yellow, and lighting them, the white is light emitted. In such a manner, since the white light source is obtained by two colors compared with the usual white light source combining three colors, the whole is miniaturized, and the structure is simplified also.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white light source suitable for use as a light source such as a monochrome display device, an indicator lamp, or an illuminated switch.

[0002]

2. Description of the Related Art Conventionally, when trying to obtain a white light source, a combination of three color light sources of red, green and blue irrespective of whether the light source is an LED or a neon lamp. Normal. The LED can be used as a chip to reduce the size of the light source. In recent years, a white light source has been obtained by using LEDs and turning them on at the same time (with some time lag during pulse lighting). I have.

In this case, there is not yet a high-brightness green LED for mass production, so a neon lamp may be used for the green light source, which is combined with blue and red LEDs. Some are trying to get a white light source.

[0004]

In the conventional LED using three colors of red, green, and blue, unevenness in color due to the difference in luminous intensity and wavelength is inevitably generated by the LEDs of each color. Since there is no green LED having a high luminance, there is a problem that a white light source having a low luminance as a whole must be obtained. Further, in the manufacture, for each LED of three colors, a machine (die bond machine, wire bonder machine) must be set, and each LED must be set.
Since a current limiting resistor having a different resistance value must be provided for each ED, there is also a problem that the structure becomes complicated. The problem that the structure becomes complicated also occurred when using red and blue LEDs and a green neon lamp.

[0005]

In order to achieve the above-mentioned object, the present invention is characterized in that white light is emitted by lighting a combination of two light sources, blue and yellow.

In this case, according to the present invention, the light source of the two colors of blue and yellow can be an LED or a neon lamp.

The invention further increases the number of blue and yellow light sources by increasing the number of blue and yellow light sources,
Is used, a high-luminance white light source can be obtained by using one high-intensity blue LED as the blue LED and using a plurality of yellow LEDs.

[0008] The present invention also provides a resin-sealed substrate.
Two types of L that can emit blue light and yellow light
An LED lamp that emits white light is obtained by mounting an appropriate combination of ED chips.

[0009]

According to the first to third aspects of the present invention, the conventional 3
Since the white light source is composed of two colors as compared with a white light source formed by combining colors, the overall size can be further reduced and the structure can be simplified.

According to the second and fifth aspects of the present invention, the same operation as in the first aspect is achieved, and a green LED for lowering the overall luminance is not used. Obtainable.

According to the fourth and fifth aspects, a white light source having higher luminance can be obtained.

According to the sixth aspect of the present invention, white light can be emitted, and one or two current limiting resistors for blue and yellow are sufficient.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. In FIG. 1, mounting inserts 2b and 2c are provided above and below a base 1 with a flange 2a therebetween to form a cylindrical shape. For example, an insulating member 2 made of, for example, a synthetic resin is fitted with one of the mounting insertion portions 2c, and is fixed with an adhesive or the like. This insulating member 2
The lower end of a tubular heat dissipating member 3 made of, for example, aluminum or brass is fitted into the other mounting insertion portion 2b, and is similarly fixed with an adhesive or the like. The heat dissipating member 3 also serves as an outer case body. Although not shown, a knurling process or the like is provided on the outer periphery to increase the surface area to increase the heat dissipating effect. And an inverted truncated cone-shaped reflecting mirror 3b extending from the engaging step 3a to the end. still,
When the heat radiating member 3 is made of brass, it is desirable to apply chrome plating to the surface.

A disc-shaped substrate 4 preferably made of ceramic is fitted to the engagement step 3a of the heat radiating member 3 so as to conduct heat. For example, a silver palladium pattern is printed on the substrate 4, and a full-wave composed of, for example, four chip-shaped rectifier diodes 5a, 5b, 5c, 5d as shown in FIG. Current circuits 5 and 6
LED chips 6a, 6 for emitting yellow light
b, 6c, 6d, 6e, 6f and one chip-shaped LED 7 for emitting high-intensity blue light are adhered by using, for example, a conductive paste, and a light-transmitting light is applied thereon as shown in FIG. The resin seal 8 of the substance is covered. The rectifier diode may be entirely or partially replaced with an LED. Lead wires 9a and 9b, whose upper ends are adhered to the circuit, penetrate from the substrate 4, and the lead wire 9a is connected to the outer peripheral portion 1a of the base 1, and the other lead wire 9b is connected to the current limiting resistor 10b. Are respectively connected to the base terminals 1b.

FIG. 3 shows a circuit diagram of the white light source shown in FIG. 2. Only one current limiting resistor 10 is required, and the current limiting resistor 10, the LED 7 for emitting blue light, and the LEDs 6a to 6f for emitting yellow light are provided. They are connected in series. Each LED
Direct current is applied to 7, 6a to 6f via the full-wave current circuit 5.

Naturally, this circuit diagram is one line, and depending on the combination of the LEDs that emit blue and yellow light, a current limiting resistor may be required for each of the LEDs that emit blue and yellow light.

The brightness of the white light source thus configured is measured and compared with the conventional one as follows. However, the measurement was carried out by incorporating the device into a ready-made illuminated switch and measuring the luminance of the illuminated surface of the switch.

When the current value and the number of LED elements of this conventional device are brought close to the same condition, Therefore, 161 / 61.4 = approximately 2.6, and even in this case, the luminance of the present invention is about 2.6 times that of the conventional luminance.

The number and type of the LEDs that emit blue and yellow light are not limited to those of the above embodiment. It consists of one high-intensity blue LED and one high-intensity yellow LED.
It can be used in a one-to-one correspondence, and has a high-luminance blue-emitting LE
By using D and a plurality of high-brightness yellow light emitting LEDs, a white light source with higher brightness can be obtained.
Conventionally, a three-color LED is used, and each current value is controlled by a respective current limiting resistor so that a white light source is used. However, in the present invention, only a two-color LED is used. The white light source can be obtained by variously combining the number of LEDs, and the control of the current value does not have to be performed for each LED. However, this is the case where one blue-emitting LED and one yellow-emitting LED are used. If the luminance cannot be balanced, a current limiting resistor is inserted in each LED to limit the current, and the luminance is reduced. Does not prevent obtaining a white light source.

[0020]

The present invention is configured as described above.
The following operational effects can be obtained.

According to the first and third aspects of the present invention, an inexpensive white light source having a simple structure can be obtained.
As a light source for various displays, an illuminated switch, or a large-scale outdoor monochrome display device in the daytime, an easily viewable display can be performed. In the case of a display, by using a lamp-type light source, there is no need to replace each unit when the lamp burns out or during maintenance, and there is a cost advantage because only the lamp needs to be replaced.

According to the second and fifth aspects, the same effects as those of the first aspect are obtained, and the structure becomes simpler than that of a conventional three-color LED using a white light source. However, it is possible to provide a white light source with less luminance and high luminance at low cost.

According to the fourth and fifth aspects, it is possible to obtain a white light source having high luminance close to white with a simple structure and at a low cost.

According to the sixth aspect of the present invention, the number of current limiting resistors can be reduced, so that the structure is simplified and the device can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an LED lamp for obtaining a white light source according to the present invention.

FIG. 2 shows an LED on a substrate of the LED lamp shown in FIG.
FIG. 9 is an explanatory diagram showing an example of mounting other elements.

FIG. 3 is a circuit diagram of a white light source.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 4 Substrate 5 Full-wave current circuit 6a-6f Yellow LED 7 Blue LED 8 Resin sealing 10 Current limiting resistor

Claims (6)

[Claims] 1. A white light source characterized in that white light is emitted by lighting a combination of two light sources of blue and yellow. 2. The white light source according to claim 1, wherein the light sources of the two colors of blue and yellow are LEDs. 3. The white light source according to claim 1, wherein the light sources of the two colors of blue and yellow are neon lamps. 4. The white light source according to claim 1, wherein the number of blue and yellow light sources is larger for the yellow light source. 5. The method according to claim 1, wherein in using LEDs for the blue and yellow light sources, one blue LED is used for high-intensity blue light and a plurality of yellow LEDs are used. The white light source described. 6. Two kinds of LED chips capable of emitting blue light and yellow light are mounted on a resin-sealed substrate.
Characterized in that they are mounted in appropriate combinations.
ED lamp.