JP2011113876A - Led type illumination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED type illumination device which can emit light and be stably used over a long period. <P>SOLUTION: The LED type illumination device includes: a cylindrical tube body 11 made of polycarbonate; a heat sink 16 made of aluminum attached to an opening portion 11a installed at a part of the peripheral face of that tube body; and a plurality of LEDs 14 mounted in that cylindrical tube body. The LEDs are connected to the heat sink via a mounting substrate 15/heat dissipation sheet 17. The heat sink is formed as a hollow structure, and a radius of the tube body and a radius of curvature on the outer surface exposed to the opening portion of the heat sink are made equal to each other, thereby having one cylindrical tube as a whole and an equivalent configuration with an existing fluorescent lamp. By achieving weight reduction with the hollow structure, the heat sink can be used as it is without fear of falling even if mounted on a socket of an existing lighting fixture. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an LED illumination device using LEDs as a light source, and more specifically to an illumination device that is replaced with a fluorescent lamp.

  In recent years, light bulbs using LEDs (light emitting diodes) as light sources have been commercialized in place of incandescent light bulbs in order to save energy and prolong life. In addition, fluorescent lamps have a longer life than incandescent bulbs, but the light emission state deteriorates with long-term use. The deterioration of the light emission state includes a decrease in light emission amount, blinking, flickering, and the like. Thus, lighting devices using LEDs have also been proposed for straight tube fluorescent lamps (Patent Documents 1 and 2).

  The illumination device disclosed in Patent Document 1 is configured by inserting and arranging a substrate in which a plurality of LEDs are linearly arranged in an acrylic cylindrical lamp case. In the case of an LED type lighting device, how to dissipate the heat generated from the LED is an important requirement for extending the life. Therefore, in the lighting device disclosed in Patent Document 1, a strip-shaped aluminum plate having a width wider than that of the substrate is attached to the back side of the substrate on which the LED is mounted. The width of the aluminum plate is approximately equal to the diameter of the lamp case, and the aluminum plate is disposed on the center line of the lamp case. The space in the lamp case is filled with silicon. Thereby, the heat generated from the LED is transmitted through the aluminum plate and further through the silicon, and diffuses toward the outer periphery.

  In addition, when the lighting device disclosed in Patent Document 2 is mounted on a tubular body having a gap, a substantially block-shaped block is fixed by being sandwiched between the gaps when the metal block having a cross-sectionally-shaped section is attached. Yes. That is, the block includes a flat upper side, a lower side made of an outer shape that matches a part of the inner shape of the tubular body, and a narrow intermediate portion that connects the upper side and the lower side. It consists of a dense body. The above-mentioned intermediate part is inserted into the gap that becomes the cut line of the tubular body, and the upper side part is projected to the outside of the tubular body. Further, the lower side portion is located in the tube, and a substrate on which LEDs are mounted is mounted on the flat surface. Thereby, the heat generated from the LED is transmitted through the dense metal block, and is radiated to the outside from the upper side protruding outside the tube.

  Further, in order to enhance the heat dissipation effect from the configuration shown in Patent Document 2, as shown in FIG. 1, there is one in which a large heat sink 3 is attached to the substrate 2 on which the LED 1 is mounted. According to this structure, since the heat sink 3 protrudes with respect to the pipe body 4 and is exposed, the surface area exposed to the outside is large and the heat dissipation effect is enhanced.

JP 2009-54405 A JP 2009-105354 A

  Since the lighting device disclosed in Patent Document 1 has a configuration in which a substrate on which an LED is mounted is housed in a cylindrical lamp case, the path of heat conduction to the outside world is limited. I must. That is, the heat path from the inside of the lamp case to the outside is a path through which heat generated during LED light emission passes through a resin such as silicon sealed in the lamp case. And since the plastics that make up the filled resin and the lamp case generally have a lower thermal conductivity than metal, the amount of heat released to the outside through the outside of the plastic lamp case is limited. Actually, the heat treatment is not sufficient.

  In Patent Document 2, since the substrate on which the LED is mounted and the aluminum block are in contact with each other, and the aluminum block is transmitted and radiated as it is to the atmosphere outside the tube, heat dissipation is less than that of the lighting device of Patent Document 1. It becomes good. However, the use of a dense aluminum block for the heat-dissipating part increases the weight of the product as a whole, and there is a risk of falling if it is attached to the socket of a fluorescent lamp fixture made in consideration of standard fluorescent lamp installation. In particular, the risk of vibrations such as earthquakes increases.

  In addition, if the structure as shown in FIG. 1 is used, the heat sink jumps out of the round tube, and it cannot be attached to the fluorescent lamp fixture to which the existing fluorescent lamp is mounted. Therefore, the entire fluorescent lamp fixture needs to be replaced. There is a problem.

  In order to solve the above problems, the LED illumination device of the present invention is mounted on (1) a transparent or translucent cylindrical tubular body and an opening provided on a part of the peripheral surface of the tubular body. And a plurality of LEDs mounted in the tube. The LEDs are directly or indirectly connected to the heat sink, and the heat sink has a hollow structure. Since the LED is directly or indirectly connected to the heat sink, heat generated from the LED is transmitted to the heat sink. And since the one part surface of a heat sink is exposed outside via the opening part of a tubular body, it can thermally radiate | emit outside efficiently from there and can suppress the temperature rise in a tubular body. Therefore, it is possible to extend the life of the LED and thus the LED illumination device (for example, about four times that of a conventional fluorescent lamp). And the maintenance man-hour of replacement | exchange of a LED type illuminating device is also reduced to about 1/4 of the conventional by life extension. Of course, since the power consumption is about 40%, the power consumption can be reduced. Since the inside of the heat sink is hollow, the heat sink portion is reduced in weight, and as a result, the entire LED lighting device can be reduced in weight. Therefore, even if it attaches to the lighting fixture which attaches the existing fluorescent lamp, even if it takes the conventional connection structure, it can hold | maintain stably and can prevent fall as much as possible.

  (2) The surface shape exposed to the outside of the heat sink is preferably along the surface shape in the vicinity of the opening of the tubular body (matches the extended surface). Along with the surface shape, for example, the surface of the tube body is the same as the extended surface of the surface of the adjacent tube body and the surface shape of the heat sink (they are flush with each other) and does not protrude greatly outward at the heat sink part. Says a state that becomes gentle. As a result, it can be easily attached to an existing lighting fixture for a fluorescent lamp, and the user does not feel uncomfortable. As an example in which the surface shapes match, as in the embodiment, when the tube is cylindrical, the surface shape of the heat sink is also a curved arc. Further, when the tubular body is rectangular, the surface shape of the heat sink is also a flat surface.

  (3) The tube may be a cylinder, and the radius of the tube may be equal to the radius of curvature of the outer surface exposed at the opening of the heat sink.

  (4) The heat sink may be made of any one of aluminum, copper, magnesium, and iron. For example, by using metal, the heat sink has a good thermal conductivity and a high heat dissipation effect. Among them, the above materials have a better thermal conductivity and are easily available at low cost. It is preferable because it is a material and can be easily processed. Furthermore, aluminum is the best in terms of weight reduction.

  (5) The heat sink may include a rib for connecting inner surfaces facing each other in a hollow space. By providing the ribs in this way, the strength is increased, and a desired shape can be maintained over a long period of time without causing bending or warping, and a long-term use can be endured.

  (6) It is good to position the light emission surface of the said LED above the center part of the said tubular body. Here, the upper side is the upper side when the light emitted from the LED is directed downward. If it does in this way, a light radiation angle can be made wide and it can irradiate in a wide range.

  According to the present invention, it is possible to reduce the weight and stably attach the apparatus to the apparatus while using a part or all of the existing equipment (lighting fixture) that holds the fluorescent lamp.

It is a figure which shows an example of the conventional LED type illuminating device. It is a figure which shows suitable one Embodiment of a LED type illuminating device. (A) is the sectional drawing, (b) is a sectional view of a tubular body. It is an expanded sectional view showing mounting board 15 and LED14. It is sectional drawing which shows other embodiment.

  Hereinafter, preferred embodiments of the present invention will be described. As shown in FIG. 2, the lighting device 10 includes a cylindrical tube body 11 having both ends opened, a base 12 attached to both ends of the tube body 11 to be closed, and an LED 14 mounted in the tube body 11. And an attached band plate-shaped mounting substrate 15.

  The tube body 11 is made of transparent or translucent polycarbonate and has a substantially C-shaped cross section. That is, the main body 11a of the tube body 11 is cut at a part of its circumference to be provided with the opening 11b. The opening 11b is formed so as to extend in the axial direction from one end to the other end of the main body 11a. Then, a first projecting piece 11c and a second projecting piece 11d are formed over the entire length at both inner ends facing each other by being cut away from the opening 11b of the main body 11a. The first projecting piece 11c and the second projecting piece 11d are arranged in parallel at a constant interval, and a guide groove 11e is formed between the first and second projecting pieces 11c, 11d. The mounting substrate 15 is supported by inserting the side edge of the mounting substrate 15 into the guide groove 11e.

  The mounting substrate 15 is made of a glass epoxy substrate, and a predetermined printed wiring is formed on the surface thereof. A large number of LEDs 14 are mounted at predetermined positions on the mounting substrate 15, and the soldering leads of the LEDs 14 and the printed wiring are connected by soldering or the like. The LEDs 14 are arranged in a line at a constant pitch, but the layout is arbitrary. In addition, the lighting device 10 of the present embodiment uses a glass epoxy substrate as the mounting substrate 15 to reduce the weight.

  By optimizing the mounting pitch of the LEDs 14 on the mounting substrate 15 and the light transmittance of the tube 11, glare of the LEDs 14 can be prevented. At this time, by arranging the mounting position of the mounting substrate 15 as far as possible from the center of the tube body 11 (upper side in FIG. 3), the light distribution characteristic can be made close to that of a conventional fluorescent lamp.

  The back surface of the mounting substrate 15, that is, the non-mounting surface of the LED 14 is mounted with a heat radiation sheet 17 having good thermal conductivity, and the heat sink 16 is mounted on the heat radiation sheet 17. The heat-dissipating sheet 17 has a certain degree of elasticity, and deforms and adheres to the shape of the contact surface of the other party to be contacted. Therefore, when the heat sink 16 is brought into direct contact with the back surface of the mounting substrate 15, the contact surfaces are not mirror surfaces, so there are non-contact portions when viewed microscopically, but in this embodiment both surfaces of the heat dissipation sheet 17 are present. Since each adheres closely, the efficiency of heat conduction becomes high. Instead of the heat radiating sheet 17, a resin layer having good thermal conductivity may be provided.

  In this embodiment, the heat radiation sheet 17 is provided on the entire back surface side of the mounting substrate 15, but may be provided on a part thereof. In that case, in order to efficiently transmit the heat generated from the LED 14 serving as a heat generation source to the heat sink 16 side, it is preferable that the LED 14 is disposed at least on the back surface region of the mounting portion of the LED 14 and its periphery.

  Bonding between the heat radiation sheet 17 and the mounting substrate 15 and between the heat radiation sheet 17 and the heat sink 16 can be performed by bonding using an adhesive or the like. Further, for example, the mounting substrate 15 and the heat sink 16 may be coupled with bolts / nuts or the like with the heat radiation sheet 17 interposed therebetween. Furthermore, when the overlapping portion of the mounting substrate 15, the heat radiation sheet 17, and the heat sink 16 is inserted into the guide groove 11e, it can be fixed with a certain force by being sandwiched between the first and second projecting pieces 11c and 11d. In such a configuration, the mounting substrate 15, the heat radiation sheet 17, and the heat sink 16 may be fixed by the sandwiching force. Of course, various other methods can be employed. Further, when performing mechanical fixing such as clamping between bolts and nuts and the first and second projecting pieces 11c and 11d, between the heat radiation sheet 17 and the mounting substrate 15, and between the heat radiation sheet 17 and the heat sink 16. One of them is preferably fixed with an adhesive or the like because workability is improved.

  The heat sink 16 is made of aluminum. Of course, the material constituting the heat sink 16 is not limited to aluminum, and various metals such as copper, magnesium, and iron can be used. However, aluminum is suitable because of its good thermal conductivity and light weight.

  The shape of the heat sink 16 includes a flat plate-like base portion 16a that is brought into contact with the heat radiating sheet 17, and a curved portion 16b that is disposed on the non-contact surface side of the base portion 16a with the heat radiating sheet 17. A predetermined space is secured between 16a and the curved portion 16b. Since the space is provided in this way, the weight can be reduced. The radius of curvature of the curved portion 16b is matched with the radius of the tube body 11 (main body 11a), and the centers of both when the heat sink 16 is attached to the tube body 11 are also matched. Further, the central angle of the arc portion of the curved portion 16b is made to coincide with the central angle of the portion of the tubular body 11 where the opening 11b is provided. Thereby, as shown in FIG. 3 etc., when the heat sink 16 is attached to the opening 11b of the tube 11 (main body 11a), the opening 11b is closed by the curved portion 16b of the heat sink 16, and the tube 11 The curved portion 16b of the heat sink 16 is arranged on the circumference of the (main body 11a). That is, like a normal fluorescent lamp (fluorescent tube), it has a single cylindrical shape, and does not feel strange.

  Furthermore, the heat sink 16 is provided with a groove portion 16c extending in the axial direction at a joint portion between the base portion 16a and the curved portion 16b. The groove 16c is fixed by being fitted to the first protruding piece 11c. Since the tip 11c 'of the first protrusion 11c swells and the groove 16c narrows toward the tip (outside), when the first protrusion 11c is fitted into the groove 16c, the first protrusion 11c and the heat sink 16 Adheres to each other, providing waterproof and dustproof performance.

  Thereby, the heat generated from the LED 14 is transmitted from the mounting substrate 15 to the heat sink 16 via the heat radiating sheet 17, and can be radiated from the curved portion 16 b exposed to the outside of the heat sink 16.

  Since the heat sink 16 has a hollow structure and the weight of the heat sink 16 can be reduced, the heat sink 16 can be accommodated in the tube body 11 as in this embodiment. Therefore, as described above, the outer shape is the same as that of a normal fluorescent lamp. For example, it can be installed simply by replacing the LED illumination device of the present embodiment with respect to an existing general fluorescent tube. And since the weight of the whole apparatus is also light, even if it attaches the terminal 12a provided in the nozzle | cap | die 12 to the socket of the existing lighting fixture, there is no fear of dropping.

  Furthermore, in this embodiment, the structure of the mounting substrate 15 is shown in FIG. 4 in order to enhance the heat dissipation effect. That is, a through hole 15 a is provided in a part of the mounting substrate 15 that faces the LED 14. The through-hole 15a is filled with a heat radiation type resin 18. Thereby, the heat generated from the LED 14 passes through the resin 18 in the through hole 15 a and is efficiently transmitted to the back surface side of the mounting substrate 15. Further, a cover plating 17 is formed on a predetermined surface portion of the mounting substrate 15 including the resin 18 portion. By performing soldering using the lid plating 17 portion, it is possible to satisfactorily bond with the solder.

  FIG. 5 shows another embodiment of the present invention. 5A, a rib 16e that connects the base portion 16a and the curved portion 16b is provided in the internal space of the heat sink 16 having a hollow structure. One rib 16e is provided on the center line along the longitudinal direction (axial direction). Providing the ribs 16e in this manner is effective in improving the rigidity in the longitudinal direction, and hardly changes over time (not easily warped) during use.

  Further, the rib 16e is not limited to one provided as in this embodiment, and two ribs 16e may be provided as shown in FIG. As the number increases, the rigidity increases, but the space occupation ratio in the heat sink 16 decreases and the weight increases. Therefore, it is preferable to use one or two.

Further, as shown in FIG. 5C, a wiring pattern is directly formed on the base portion 16a of the heat sink 16 having a hollow structure, and the LED 14 is mounted so as to be electrically connected to the wiring pattern. Thereby, since the heat generated from the LED 14 is directly transmitted to the heat sink 16, the heat dissipation effect is further enhanced.
In addition, since these each embodiment is the same as that of embodiment shown in FIGS. 2-4 in the fundamental structure, the same code | symbol is attached | subjected to a corresponding member and the detailed description is abbreviate | omitted.

DESCRIPTION OF SYMBOLS 10 Illuminating device 11 Tube 11a Main body 11b Opening part 12 Base 14 LED
15 Mounting board 16 Heat sink 16e Rib 17 Heat dissipation sheet

Claims (6)

A transparent or translucent cylindrical tubular body, a heat sink attached to an opening provided in a part of the circumferential surface of the tubular body, and a plurality of LEDs mounted in the tubular body,
The LED is connected directly or indirectly to the heat sink;
The LED-type lighting device, wherein the heat sink has a hollow structure.   2. The LED illumination device according to claim 1, wherein a surface shape exposed to the outside of the heat sink follows a surface shape in the vicinity of the opening of the tubular body.   3. The LED-type lighting device according to claim 1, wherein the tubular body is a cylinder, and a radius of the tubular body is equal to a radius of curvature of an outer surface exposed to the opening of the heat sink. .   The LED-type lighting device according to any one of claims 1 to 3, wherein the heat sink is made of any one of aluminum, copper, magnesium, and iron.   The LED-type lighting device according to any one of claims 1 to 4, wherein the heat sink includes a rib that connects inner surfaces facing each other in a hollow space.   The LED illumination device according to any one of claims 1 to 5, wherein a light emitting surface of the LED is positioned above a central portion of the tubular body.

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