JP2014154479A - LED lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out light emitting dispersion and heat dispersion in an LED lamp at low cost using a glass tube and to assure safety for break-down of the glass tube.SOLUTION: An LED lamp comprises: a tubular glass tube; caps having power terminals and blocking up both end openings of the glass tube; a substrate on which multiple LED elements and a drive circuit lighting and driving the LED elements by getting electric source from the power terminals are mounted; a heat sink which the substrate is mounted to and crosslinking the caps in the glass tube; an adhesive filled between the inner face of the glass tube and the heat sink; and a milky-white heat shrink tube coating the external circumference of the glass tube and having translucency.

Description

  The present invention relates to an LED lamp using an LED element, for example, a technique effective when applied to an LED lamp that replaces a straight tube fluorescent lamp.

  Since each LED element emits a small amount of light, it is possible to obtain the required amount of light by arranging a large number of LED elements on a substrate and using it as a line light source. However, since the directivity of the emitted light is strong, the emitted light is dispersed. It is necessary to make it. Patent Document 1 discloses a technique using a translucent glass tube subjected to frost processing.

  Moreover, since the LED element has a large calorific value, the heat dissipation can be improved by mounting a substrate on which the LED element is mounted on the heat sink. In Patent Document 2, in order to reduce the weight of the LED lamp, a heat sink is not used. Instead, the substrate is bonded to the inner surface of the glass tube by using an adhesive, and the heat generated by the LED is transferred to the glass through the adhesive. It is described to conduct to a tube. In particular, in Patent Document 2, a glass tube used in a straight tube fluorescent lamp is mounted with a substrate on which an LED element is mounted, and a fluorescent film is applied to the inner surface of the glass tube to convert the wavelength of light. There is a description of the LED lamp.

JP 2011-138681 A JP 2009-158646 A

  The present inventor has examined the realization of low-cost dispersion of light emission and heat dissipation in an LED lamp. As a result, the frost processing applied to the glass tube for dispersion of light emission as in Patent Document 1 is costly. In addition, as in Patent Document 2, simply by bonding a substrate instead of a heat sink to a glass tube, heat dissipation efficiency is lowered. Moreover, since the heat transfer from the substrate of the LED element to the glass tube is direct and local, the glass tube may be damaged by heat.

  The present invention has been made in view of the above problems, and novel features thereof will become apparent from the description of the present specification and the accompanying drawings.

  The following is a brief description of an outline of typical inventions disclosed in the present application.

  That is, the LED lamp has a cylindrical glass tube, a power supply terminal, a cap that closes the opening at both ends of the glass tube, a plurality of LED elements, and receives power from the power supply terminal to light the LED element. A substrate on which a driving circuit for driving is mounted; a heat sink on which the substrate is mounted and cross-linked to the cap inside the glass tube; and an adhesive filled between the inner surface of the glass tube and the heat sink And a milky white heat-shrinkable tube having translucency coated on the outer periphery of the glass tube.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  That is, the glass tube of the straight tube fluorescent lamp can be used, and it is not necessary to perform any special matte processing that can be frosted on the surface, so that the cost can be reduced. Since a heat sink is used, the heat dissipation effect is improved accordingly. Since a heat sink is interposed between the substrate and the inner surface of the glass tube, local temperature rise of the glass tube can be mitigated. Even if the glass tube is damaged, it is possible to prevent the glass pieces from being scattered by the heat-shrinkable tube. Since the heat-shrinkable tube is translucent milky white, it is possible to obtain the light diffusing performance from the LED element. Even when a glass tube having a fluorescent film coated on the inner surface is used, an arc that easily reinforces diffusion of light emission can be formed. Therefore, dispersion of light emission and heat dissipation in the LED lamp can be realized at low cost by using the glass tube, and safety against breakage of the glass tube can be ensured.

FIG. 1 is an exploded perspective view of one end side of an LED lamp according to the present invention. FIG. 2 is an exploded perspective view of the LED lamp of FIG. 1 viewed from the back side. FIG. 3 is an external perspective view of one end side of the LED lamp according to the present invention.

  The LED lamp 1 illustrated in the exploded perspective view of FIG.1 and FIG.2 has the glass tube 2 which comprises a cylinder shape. The glass tube 2 is made of soda glass, for example, and may be transparent, or a fluorescent film may be applied to the inner surface, or an appropriate white resin may be applied. In consideration of cost, transparency is preferable, and it is also preferable to use a fluorescent tube glass tube coated with a fluorescent film. As the fluorescent film, a known phosphor such as a barium strontium type used in a fluorescent lamp may be used. For example, the glass tube 2 is formed to have a diameter of 25 mm and a total length of 34 mm. In the figure, the glass tube 2 is shown as a transparent body.

  Both ends of the glass tube 2 are closed by caps 3 corresponding to so-called caps, and a heat sink 5 on which a substrate 4 is mounted is bridged between the caps 3 at both ends (only one is shown in the figure and the other is not shown). The

  The cap 3 has a power supply terminal 6 exposed to the outside, and is formed in a flange shape. The flange-shaped small diameter portion is inserted into the glass tube 2 and positioned. Although illustration is omitted, a rubber or resin packing is attached to the outer periphery of the flange-shaped small-diameter portion, and this is in close contact with the inner peripheral surface of the glass tube 2 so that the inside of the glass tube 2 is confidential or waterproof. Can be improved.

  The external terminal 6 is assumed to be a terminal structure adopted in the “L-shaped pin cap GX16t-5” of the Japan Light Bulb Industry Association standard or other conventional pin structures.

  The substrate 4 is configured, for example, by arranging a large number of LED elements 7 on a wiring board and mounting a drive circuit (not shown) for driving the LED elements 7 to emit light. The substrate 4 is mounted on the front surface of the heat sink 5 made of aluminum or resin and fixed with an adhesive or the like. The end face of the heat sink 5 is locked inside the cap 3 or is fixed to the cap 3 with a screw (not shown) penetrating from the outside of the cap 3 to be bridged inside the glass tube 2. Between the back of the cross-linked heat sink 5 and the inner surface of the glass tube 2, an adhesive 8 such as silicon resin, acrylic resin or natural rubber is filled and fixed. Heat generated by light emission driving of the LED element 7 on the substrate is transmitted to the heat sink 5 and dispersed, and further the dispersed heat is transmitted to the glass tube 2 through the adhesive 8.

  The outer periphery of the glass tube 2 is covered with a translucent milky white heat-shrinkable tube 9. The heat-shrinkable tube 9 diffuses the light emitted from the LED element 7. Moreover, when the glass tube 2 is damaged, the fragments are prevented from scattering. In particular, since the outer diameter of the cap 3 and the outer diameter of the glass tube 2 are formed with the same dimensions, no step is formed, and the shrinkage allowance of the heat-shrinkable tube 9 is different between the cap 3 side and the glass tube 2 side. Therefore, the adhesion between the glass tube 2 and the cap 3 is improved, and an excellent diffusion effect and scattering prevention effect are obtained. Moreover, when the outer diameter of the cap 3 and the glass tube 2 is made the same dimension, the waterproof effect when attached to a waterproof socket is also improved.

  According to the said embodiment, the following effects are obtained.

  (1) A glass tube of a straight tube fluorescent lamp can be used, and it is not necessary to perform any special matte processing that can be frosted on the surface, so that the cost can be reduced.

  (2) Since the heat sink 5 is used, the heat dissipation effect is improved accordingly.

  (3) Since the heat sink 5 is interposed between the substrate 4 and the inner surface of the glass tube 2, the local high temperature of the glass tube 2 can be reduced.

  (4) Even if the glass tube 2 is damaged, the heat-shrinkable tube 9 can prevent the glass pieces from scattering.

  (5) Since the heat-shrinkable tube 9 is milky white with translucency, it is possible to obtain diffusion performance for light emission from the LED element 7. Even when a glass tube having a fluorescent film coated on the inner surface is used, the diffusion of light emission can be easily reinforced.

  (6) Accordingly, it is possible to realize the dispersion of light emission and heat dissipation in the LED lamp at a low cost using the glass tube 2 and to ensure the safety against breakage of the glass tube 2.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, the size of the glass tube, the electrode structure of the external terminal 6, the arrangement state of the LED elements 7 on the substrate 4 can be appropriately changed. The shape of the heat sink is not limited to the shape in which a large number of fins are formed on the surface, and an appropriate shape may be adopted, and it is desirable that the contact area with the substrate 4 is large.

DESCRIPTION OF SYMBOLS 1 LED lamp 2 Glass tube 3 Cap 4 Board | substrate 5 Heat sink 6 Power supply terminal 7 LED element 8 Adhesive 9 Heat-shrinkable tube

Claims (5)

A cylindrical glass tube,
A cap having a power terminal and closing both ends of the glass tube;
A substrate on which a plurality of LED elements and a driving circuit for receiving and driving power from the power supply terminal and driving the LED elements are mounted;
A heat sink mounted with the substrate and cross-linked to the cap inside the glass tube;
An adhesive filled between the inner surface of the glass tube and the heat sink;
An LED lamp comprising: a translucent milky white heat-shrinkable tube coated on the outer periphery of the glass tube.   The LED lamp according to claim 1, wherein the adhesive is a silicone resin.   The LED lamp according to claim 2, wherein the glass tube is a transparent glass tube.   The LED lamp according to claim 3, wherein a fluorescent film is applied to an inner surface of the glass tube.   The LED lamp according to claim 4, wherein an outer diameter of the cap is the same as an outer shape of the glass tube.

Images