JPH0263231B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to various signal lights or indicator lights using a large number of LEDs as a light source.

[Prior art]

Various structures of this type of signal light or indicator light are known. For example, a large number of LEDs are mounted on a printed circuit board of a predetermined size in an embedded state and are also mounted in a cluster to serve as a light source, a heat sink or heat sink is integrally mounted on the back side of the printed circuit board, and a heat sink is attached on the front side. It has a structure in which lenses are attached at a predetermined space. The reason why the heat sink or heat sink is installed is because of the LED light source.
This is to dissipate the heat emitted from the
The LED itself has a characteristic that as the internal temperature rises, the light emitting output with the same current decreases, and this is to prevent the illuminance from decreasing due to long-term use.

[Problem that the invention seeks to solve]

However, in the structure of the conventional example,
The problem is that because the LED is in contact with the air in the space, heat transfer through the air to the printed circuit board and lens is slow, and the heat dissipation effect is insufficient, causing the internal temperature of the LED to rise and the light output to decrease. There is a point. Furthermore, when used for long periods of time as signal lights and indicator lights, there is a limit to the internal temperature of the LED, so the current value is also limited so that it does not exceed that temperature, resulting in a lamp that produces less light overall due to poor heat dissipation. It also has the problem of becoming.

[Means for solving problems]

As a specific means for solving the above-mentioned problems, the present invention provides an indicator lamp in which a radiator is attached to the back side of a printed circuit board on which a large number of LEDs are arranged, and a lens is arranged on the front side. An LED indicator light, characterized in that the lead part of the standing LED is sealed with a material having good thermal conductivity so as to cover it, and the space between the LED and the lens is filled with a light-transmitting liquid. The heat emitted from the LED is quickly conducted through the liquid to the lens side and the material side with good thermal conductivity, and heat exchange takes place on the radiator and lens surface, so the heat remaining inside the LED is reduced. As a result, the amount of light emitted increases.

〔Example〕

Next, the present invention will be explained in more detail with reference to illustrated embodiments. In the first embodiment shown in FIG.
1 is a printed circuit board, on which a large number of LEDs 2 are attached adjacently or in a group,
The lead portions 3 of the LEDs 2 are lined up in a planted state.
This printed circuit board 1 is integrally attached to a recess 4a of a heat radiator via a thermally conductive compound 5, and the heat radiator 4 is provided with a large number of heat radiating fins 6.

An LED is installed on the front side of the printed circuit board 1 installed in the recess 4a, that is, on the side where the LED 2 is installed.
In order to improve heat dissipation from the lead part 3 of 2, the lead part 3 is wrapped and sealed with a material 7 having good thermal conductivity. In this case, the material 7 is, for example, a mixture of epoxy resin and silicon carbide powder or alumina powder, which is filled by a potting method and wraps around the lead portion.

A lens 9 is further disposed on the front side of the printed circuit board 1 with an appropriate space 8 therebetween. In this case, the space 8 is filled with a light-transmitting liquid 10. This liquid is an inert liquid that does not have solvent properties, and for example, Freon liquid or the like is used. Considering that the liquid 10 is filled in this way, the lens 9 extends the circumferential surface 9a and is fitted to the circumferential surface of the radiator 4 for sealing, and the lens itself is eventually filled with the liquid 10.
It becomes a container filled with 0.

The second embodiment shown in FIG. 2 is the same as the first embodiment, except that the liquid is circulated in a part to the back side of the radiator, and the other parts are almost the same. Reference numerals are given and explanations thereof are omitted.

In this second embodiment, a circulation path 11 is provided in a part of the heat radiation fin 6 provided on the heat radiator 4, and the circulation path is formed in a space on the front side by grooves 12 and 13 provided on the circumferential side of the heat radiator 4. It communicates with 8. in this case,
The circumferential side surface 9a of the lens 9 is formed to have a length that reaches the back end of the radiator 4, and is hermetically sealed at the back end. Also, the circulation path 11
has a tubular shape, and the number of rows of aligned heat dissipation fins 6 is selectively selected in the vertical direction, for example, every other row or every second row, and grooves 12 and 13 are provided corresponding to the rows. It is.

[Effect]

In the case of the LED signal light or indicator light of the present invention having the above configuration, it serves as a light source disposed inside.
Heat emitted from the LED 2 is conducted from the lead part 3 to the heat radiator 4 through the thermally conductive material 7 and from the printed circuit board 1 and the thermally conductive compound 5 on the one hand, and is radiated through the liquid 10 on the other hand. Heat is radiated from the lens 9 via the LED 2
Heat no longer stagnates inside. in short
All the materials surrounding the LED 2 perform heat conduction to carry and release heat to the outside.

Furthermore, by providing the circulation path 11 in the radiator 4, the temperature of the liquid 10 in contact with the LED 2 increases by taking heat from the LED 2, and as the heated liquid 10 rises, it is cooled in the circulation path 11. As the liquid 10 descends, the liquid filling the space 8 causes natural convection through the circulation path 11, and actively cools the LED 2.

〔Effect of the invention〕

As explained above, in the LED indicator light according to the present invention, the lead portion of the LED standing up on the printed circuit board surface is sealed with a material with good thermal conductivity so as to cover the lead portion, so that the heat emitted from the LED is transferred to the lead portion. At the same time, the heat generated by the LED is dissipated by conducting the heat to the radiator through a material with good thermal conductivity and a printed circuit board, and filling the space between the LED and the lens with liquid. Since heat is received by the liquid and dissipated through the lens in contact with the liquid, heat does not stagnate inside the LED, and even when the same current value as before is applied, the luminous efficiency is increased and a high-intensity light source can be used. It has excellent effects.

In addition, since the heat dissipation effect is large, it is possible to make maximum use of the temperature rise of the LED up to the allowable value, and it is possible to pass the current that reaches the maximum value, making it suitable for use as a signal light or indicator light at high illuminance. It also has the excellent effect of providing good visibility.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a signal light or indicator light according to a first embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a second embodiment of the same. DESCRIPTION OF SYMBOLS 1... Printed circuit board, 2... LED, 3... Lead part, 4... Heat sink, 4a... Recessed part, 5... Compound, 6... Fin, 7... Material with good thermal conductivity, 8 ...Space part, 9...Lens, 9a...
... Circumferential surface of lens, 10 ... Liquid, 11 ... Circulation path, 12, 13 ... Groove.

Claims (1)

[Claims] 1. In an indicator light in which a radiator is attached to the back side of a printed circuit board on which a large number of LEDs are arranged, and a lens is arranged on the front side, the lead part of the LED that stands up on the surface of the printed circuit board is provided. 1. An LED indicator light, characterized in that the space between the LED and the lens is filled with a light-transmitting liquid, and the space between the LED and the lens is sealed with a material having good thermal conductivity. 2. The LED indicator lamp according to item 1, wherein a circulation path is formed in the radiator by communicating with the space so that the filled liquid circulates.