JP2005303046A - Indicating lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suitably radiate the heat produced by a light emitting device and prevent the heat conduction to the light emitting device to the utmost upon soldering of a lead terminal to protect it in an indicating lamp using a high output type LED. <P>SOLUTION: A current required to supply power from lead terminals 9, 11 to the light emitting device 3 is fed through an insulating layer on the surface of a base 2, and a metal film 8 having a sufficient thickness to be able to radiate the heat from the light emitting device and having a large area nearly equal to the caliber area of a total reflection lens 5 is deposited and formed thereon. One electrode of the light emitting device is connected to a first metal film region 8a connected to one lead terminal, and the other electrode of the light emitting device is connected to a second metal film region 8b connected to the other lead terminal. Further, in the path from the lead terminal connection to the light emitting device connection in the first metal film region and the second metal film region, a heat insulator 12 is interposed wherein the metal film is peeled away to prevent the heat for soldering the lead wire to be transferred to the light emitting device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a display lamp in which a total reflection lens is disposed above a light emitting element of a high output type LED (light emitting diode) chip, and the light of the light emitting element is condensed to efficiently radiate forward with a wide light emitting area. In particular, it is possible to dissipate the heat of the light emitting element suitably, and it is difficult to transfer the heat from the lead terminal to the light emitting element when soldering the lead terminal, and it is possible to maintain suitable characteristics It relates to lamps.

In recent years, there have been many high-power LEDs that can be used for illumination. However, the area where the LED itself emits light is a pinpoint. If it is left as it is, it becomes omnidirectional illumination and light diffuses, so that a light emitting surface with a certain area cannot be formed, and visibility from a long distance is also poor. For this reason, a condensing lens that covers the front of the LED and converges the light is usually provided. As this condensing lens, a light emitting element mounting portion is formed at the bottom, and the light of the central portion irradiated from the light emitting element is condensed by a convex portion formed at the center of the front surface of the lens, and the light outside thereof is It is totally reflected by the wall surface that draws a parabolic curve from the bottom to the front and radiates forward.
Japanese Utility Model Publication No. 6-28725

  However, in the case of a normal LED, the lighting current is at most about several mA, whereas in the above-described high-power type display lamp, it is extremely large as several hundred mA. The fever that did not exist is a big problem. That is, when the ambient temperature increases, the luminous efficiency of the LED decreases and the luminous intensity decreases. For this reason, the circuit pattern is wide and the film thickness is large so as not to generate a large amount of heat due to the large resistance value of the power supply line to the LED on the circuit board. However, when soldering the lead terminal to the circuit board on which the LED is disposed, the heat transmitted from the lead terminal is transferred to the LED through a circuit pattern having excellent heat conductivity, and as a result, the LED is damaged or the characteristics are deteriorated. There was a risk of doing.

  Therefore, in the present invention, in order to solve the above-described problems, in a display lamp using a high-power LED, heat generated from the light emitting element can be suitably radiated, and light emission when the lead terminal is soldered. An object of the present invention is to provide a display lamp capable of protecting the element by preventing heat conduction as much as possible.

  In order to achieve the above object, the display lamp of the present invention has a total reflection lens disposed on the upper surface of a light emitting element disposed on a base having lead terminals, and reflects light from the light emitting element by the total reflection lens. In a display lamp that radiates to the front of the lens, the metal base surface has a conductive performance that can reliably supply power from the lead terminal to the light emitting element via an insulating layer, and heat conduction that conducts heat from the light emitting element. In the path from the connection portion of the lead terminal to the connection portion of the light emitting element in the metal coating, the metal coating having a large area substantially equivalent to the aperture area of the total reflection lens with a property, It is characterized in that a heat insulation insulating part from which a metal film for preventing heat at the time of soldering the lead wire from being transmitted to the light emitting element is interposed.

  In addition, the insulating portion is formed in an arc shape centering on the lead terminal and / or the light emitting element.

  According to the display lamp of the present invention, the metal base surface has a conductive performance capable of reliably supplying power from the lead terminal to the light emitting element via the insulating layer, and a thermal conductivity that conducts heat from the light emitting element. In the path from the connection portion of the lead terminal to the connection portion of the light emitting element in the metal coating, the metal coating having a wide area substantially equal to the aperture area of the total reflection lens The heat generated by the light-emitting element is thick and has a wide area by interposing a heat-insulating insulating part from which the metal film is peeled off to prevent heat when soldering the lead wire from being transmitted to the light-emitting element. The heat is transferred to the metal base on the back surface of the metal coating, and heat can be suitably radiated, and the heat transferred from the lead terminal to the metal coating during soldering of the lead terminals can interfere with the heat insulation. Without directly transmitted to the light emitting element is, thereby can be protected from heat transmitted to the light-emitting element from the outside.

  In addition, the insulating portion is formed in an arc shape centering on the lead terminal and / or the light emitting element, so that heat transmitted radially from the lead terminal connecting portion and heat transmitted radially to the light emitting element connecting portion are transmitted. Can effectively block.

  1 and 2 show a display lamp 1 of the present invention. This display lamp 1 is formed by integrally molding a base 2, a light emitting element 3 disposed on the base 2, and an upper part of the light emitting element 3. The convex lens unit 4 is configured to include a total reflection lens 5 disposed above the convex lens unit 4 and an opaque exterior cover 6 that covers the total reflection lens 5 from the side surface.

  An approximately rhombus-shaped base 2 made of a steel plate having a thickness of about 0.6 mm in consideration of mechanical strength and thermal conductivity is formed by first forming an insulating protective film 7 made of glass or the like on the entire surface, and energizing the base. A metal film 8 having a film thickness of 10 μm made of silver or the like serving as a circuit pattern is deposited and formed in a circular shape having a shape substantially equal to the aperture area of the total reflection lens 5, and glass or the like is formed thereon except for the connection portion. An insulating coating made of is deposited. The metal coating 8 is thicker and has a larger area than a conventional display lamp so as to have a conductive performance that allows a current to the high-power type light emitting element 3 to flow reliably and suitably. Yes.

  As shown in FIG. 2, one electrode located on the bottom surface of the light emitting element 3 is connected to the first metal film region 8 a connected to one lead terminal 9 and the other electrode located on the upper surface of the light emitting element 3. The electrode 10 is connected to the second metal film region 8b connected to the other lead terminal 11 by a bonding wire (not shown). Then, the lead wires 9 and 10 are soldered in the middle of a linear path from the lead terminal connection portions 8c and 8d to the light emitting element 3 connection portion in the first metal coating region 8a and the second metal coating region 8b. In order to prevent the heat from being transmitted to the light emitting element 3, the heat insulating insulating part 12 from which the metal film has been peeled off (not attached) is formed in an arc shape of about 90 degrees centering on the lead terminal connecting parts 8c and 8d. Forming.

  Further, in the vicinity of the light emitting element 3 in the metal coating 8, the heat insulating insulating parts 13, 14, and 15 having a smaller diameter than the heat insulating insulating part 12 are provided in the vicinity of the light emitting element 3 in order to prevent heat transmitted to the light emitting element 3 as described above. It is formed in a circular arc shape centered at. If these heat insulation parts are small, the heat insulation effect will be small, while if they are too large, the circuit pattern leading to the light emitting element will be narrow and current will not flow easily, so it is necessary to set them to an appropriate size, position and number. .

  FIG. 3 is a perspective view in which the convex lens portion 4 is halved to show the structure in the vicinity of the light emitting element 3, and a transparent acrylic substantially ring surrounding the small diameter light emitting element 3 disposed on the base 2. A frame-shaped frame 16 is disposed, and into the frame 16, a transparent synthetic resin material such as silicon that covers the light-emitting element 3 and is transparently raised from the top by a surface tension is injected. This is cured to form the convex lens portion 17. That is, the frame body 16 is a mold into which a molten synthetic resin is poured, and by making itself transparent, the light of the light emitting element 3 is completely transmitted. The convex lens portion 17 has a function of condensing light from the light emitting element 3 to a certain degree and a function of protecting a thin bonding wire (not shown) that connects the light emitting element 3 and the pattern on the base 2. Yes. By controlling the amount of the synthetic resin injected into the frame 16 to a constant amount, the convex lens portion 17 having a desired curvature can be obtained. Conventionally, the silicon varnish was applied around the light emitting element and the bonding wire with a brush. However, in this case, the radial light emission from the light emitting element to the lens body became non-uniform, and as a result, suitable for parallel light, etc. Condensation was not obtained.

  The total reflection lens 5 is made of a transparent synthetic resin material such as acrylic having a maximum outer diameter of about 21 mm and a height of about 12.5 mm, and has a substantially inverted truncated cone shape that gradually expands the width diameter toward the front. Molded. The cylindrical outer cover 6 is disposed on the base 2 while surrounding the side surface while holding the upper part of the total reflection lens 5.

  As shown in FIG. 4, the inclined peripheral wall 11 in the total reflection lens 5 is formed into a unique curved surface slightly bulging outward from the lower end of the lens to the front surface of the lens (the cross section is not limited to a continuous curved surface, and a plurality of The outer peripheral portion of the front surface of the lens may be a flat body portion 12, and a central convex lens portion 24 having a convex front (R5) at the center portion may be provided forward from a position slightly lower than the front surface of the lens. Oppositely formed. Then, the light from the light emitting element 3 such as an LED disposed at the bottom is condensed and irradiated to the front of the lens as parallel light made up of a certain amount of light.

  Under the total reflection lens 5, a substantially cylindrical hollow portion 18 having a height that is too high for the light emitting element 2 to be disposed is about 1/3 of the lens height from the lower end of the lens body. (In the conventional display lamp, the lower end of this lens has only a small-diameter hemispherical hollow portion on which the light-emitting element is disposed). And since the part which coat | covers the light emitting element 3 becomes large diameter with resin, although the frame 16 and the convex lens part 17 enlarge the hole diameter of the hollow part 18 of a lens so that the total reflection lens 5 may not be touched. Since increasing the hole diameter of the entire hollow portion 18 greatly affects the optical path that is totally reflected by the lens peripheral wall, the minimum structural change is made to avoid this, and only the lower portion of the hollow portion 18 is changed. In order to enlarge the hole diameter, the stepped portion 22 is formed so as to protrude. However, if the step portion 22 is simply leveled, the light from the light emitting element 2 is refracted by the step portion 22 and becomes a different unintended optical path. In order to prevent the light from being incident on the taper, the taper is outwardly tapered. The upper surface 18a of the hollow portion 18 is a concave spherical surface (R4) as viewed from the light emitting element 3, and the side peripheral surface 18b of the hollow portion 18 has a hole diameter from the lower end of the total reflection lens 5 toward the front of the lens body. A slight taper that gradually narrows is provided, whereby the hollow portion 18 is formed in a substantially cylindrical shape. The hole diameter, height, and taper of the hollow portion 18 are set according to the dimensions of the light emitting element 3 disposed therein, the refractive index according to the material of the total reflection lens 5, the outer dimensions of the total reflection lens 5, and the like. The

  According to the display lamp 1 having such a configuration, as shown in FIG. 4, the light from the light emitting element 3 is first condensed to some extent by passing through the convex lens portion 17 that covers the light, and the hollow portion 18. Continue on. Then, the light traveling from the convex lens portion 17 toward the upper surface 18a of the hollow portion 18 enters the concave curved surface of the upper surface 18a substantially perpendicularly (below the total reflection angle corresponding to the refractive index of the lens) and travels straight through the lens body. Then, the light is refracted in the direction of being condensed by the central convex lens portion 24 on the front surface of the lens and irradiated to the front of the lens. In the present embodiment, the light passing through the convex lens portion 17 is made into parallel light by setting the curvature of the convex lens portion 17 in accordance with the refractive index of the acrylic lens. Further, the light traveling from the convex lens portion 17 toward the side peripheral surface 18b of the hollow portion 18 is refracted by being incident on the side peripheral surface 18b at a total reflection angle or less corresponding to the refractive index of the lens, and the above-mentioned relative to the peripheral wall 20. It is totally reflected by being incident at a total reflection angle or more, and is irradiated to the front of the lens through the plane body portion 26 in front of the lens.

  In the above-described embodiment, the configuration in which the central convex lens portion 24 is provided on the front surface of the total reflection lens 5 has been described. However, the present invention is not limited to this, and the central convex lens portion is eliminated to make the entire surface flat. Even in that case, although it is not completely parallel light as compared with the display lamp 1 of the above-described embodiment, it has a simple shape and can exhibit a light condensing action close to the corresponding parallel light. Although not particularly shown, when the light is refracted toward the center axis of the lens without going straight on the upper surface 18a of the hollow portion 18, a condensing action close to that of parallel light can be achieved. is there.

  In the embodiment described above, the shape of the hollow portion has been described as a substantially circular shape, but is not limited to this, with the boundary portion between the upper surface and the side peripheral surface of the hollow portion as a boundary, It is suitable without diffusing the light radiated from the front surface of the lens by dividing the light from the light emitting element into light that goes directly to the front surface of the lens and light that is totally reflected by the peripheral wall of the lens and goes to the front surface of the lens. Can be condensed.

It is a partially cutaway exploded perspective view of the display lamp of the present invention. It is a top view of the display lamp of this invention. It is a partially notched perspective view which shows the frame in the display lamp of this invention. It is explanatory drawing which shows the light which permeate | transmits the lens body in the display lamp of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display lamp 2 Base 3 Light emitting element 4 Convex lens part 5 Total reflection lens 6 Exterior cover 7 Insulation protective film 8 Metal film 8a 1st metal film area 8b 2nd metal film area 8c, 8d Lead terminal connection part 9 One side Lead terminal 10 Other electrode 11 Other lead terminal 12, 13, 14, 15 Thermal insulation insulating part 16 Frame 17 Convex lens part 18 Hollow part 18a Upper surface 18b Side peripheral surface 20 Peripheral wall 22 Step part 24 Central convex lens part

Claims (2)

  In a display lamp in which a total reflection lens is disposed on an upper surface of a light emitting element disposed on a base having a lead terminal and light from the light emitting element is reflected by the total reflection lens and radiated forward of the lens, a metal base is provided. The surface of the base has a conductive performance capable of reliably supplying power from the lead terminal to the light emitting element via an insulating layer and a thermal conductivity that conducts heat from the light emitting element, and is substantially equal to the aperture area of the total reflection lens. A metal film having a large area is deposited and heat is generated when the lead wire is soldered in a path from the connection portion of the lead terminal to the connection portion of the light emitting element in the metal film. A display lamp characterized by interposing a heat-insulating insulating part from which a metal film for preventing transmission to a metal is peeled off.   2. The display lamp according to claim 1, wherein the insulating portion is formed in an arc shape centering on the lead terminal and / or the light emitting element.

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