JP2005228630A - Surface light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface light source device of a direct downward type suited as a light source for a large area in which, by suppressing elevation of temperatures in the surface light source device accompanied by heat generation of bar type light sources to as the smallest degrees as possible, even when numbers of bar type light sources are increased, brightness of light can be improved, saving of electric energy can be materialized, and furthermore prolongation of product life cycle can be enhanced. <P>SOLUTION: The above problems are solved by means that a support part member 5 of the light source and a reflecting member 9 are provided with a heat radiating means to radiate the heat generated by the bar type light sources 2 by lighting the bar type light sources 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a surface light source device, and more particularly, to a surface light source device suitable for use in a liquid crystal display device used in a liquid crystal television, a monitor and the like.

  In recent years, liquid crystal display devices have been widely used in various fields such as notebook personal computers, portable telephones, and liquid crystal televisions.

  In addition, along with the further progress of IT use in the world, various technological innovations have been made for liquid crystal display devices in response to demands such as an increase in information processing amount, diversification of needs, and support for multimedia.

  Recently, digital terrestrial broadcasting has been launched, and it has become possible to enjoy interactive TV, and a liquid crystal display device with a large area and a slimmer area has attracted more attention than ever.

  Under such circumstances, liquid crystal display devices are required to have higher definition and higher contrast, and in order to realize this, first, a surface light source device with higher luminance is required.

  The liquid crystal display device basically includes a surface light source device portion and a liquid crystal display portion. As the surface light source device unit, there are a direct type having a light source disposed directly under a liquid crystal display unit and an edge light type having a light source disposed so as to face a side end surface of a light guide plate.

  For example, an edge light system is prevalent in liquid crystal display devices such as notebook personal computers, PDA devices, and mobile phones from the viewpoint of compactness. On the other hand, the direct method is suitable for a large screen that is viewed by a plurality of people such as an LCD TV and a monitor.

  Here, the edge light type has a light source arranged on one side of the light guide plate, and the light guide plate emits light in a planar shape while transmitting light. It can be made thin and compact, and from the lamp to the liquid crystal element The influence of heat can be suppressed.

  However, since the number of lamps arranged on one side of the light guide plate is limited, the edge light type has a limit when aiming for high luminance in a large area. Even if the lamp is lengthened, it grows only in one dimension.

  On the other hand, the direct method does not use a light guide plate, and a large number of lamps as rod-shaped light sources are arranged in parallel directly under the liquid crystal display unit so that light is emitted through a diffusion plate or the like. Therefore, a surface light source device with high brightness can be obtained.

JP-A-8-29785

  However, in a conventional direct-type surface light source device, when a large number of lamps are used to increase the brightness, the temperature of the device rises due to the heat generated from the lamps. It had the problem of causing a drop.

  In addition, increasing the number of lamps increases the power loss associated with the heat generated by each lamp. Under these circumstances, the power loss is greater when configuring a surface light source with a larger area than before. There was a problem that it became even larger.

  Furthermore, the rise in temperature of the surface light source device has also caused a problem that the members used such as the diffusion plate are likely to be deformed or colored.

  Therefore, the present invention has been made in view of such problems, and in a direct type surface light source device suitable for a large area surface light source, even if the number of rod light sources is increased, the surface accompanying heat generation of the rod light source. An object of the present invention is to provide a surface light source device that can improve luminance by minimizing the temperature rise of the light source device and can save power and improve product life. To do.

  In order to achieve the above-described object, the surface light source device according to claim 1 of the present invention is characterized in that a plurality of electrode portions connected to the lead wires are provided at the end portions in the longitudinal direction and arranged in parallel in a planar shape. A plurality of rod-shaped light sources, a light source support member supporting a longitudinal end of the plurality of rod-shaped light sources, and a plane on which the plurality of rod-shaped light sources are aligned. A light diffusing member that diffuses and emits light; a reflecting member that covers the plurality of rod-shaped light sources; and that guides light from the rod-shaped light sources to the light diffusing member; and the light source support member, the light diffusing member, and the reflecting member. In the surface light source device having the respective frame members to be held, the light source support member and the reflection member are provided with heat radiating means for radiating heat generated by lighting of the rod-shaped light source. A.

  And according to such a structure, since the heat | fever emitted by lighting of a rod-shaped light source can be radiated by the heat radiating means with which the light source support member and the reflection member were equipped, the temperature rise of the surface light source device accompanying the heat_generation | fever of a rod-shaped light source Can be reduced.

  The surface light source device according to claim 2 is characterized in that, in claim 1, the heat radiating means of the light source support member covers the electrode part and at least a part of the lead wire with an insulating material. A heat conductive metal member that is formed in a shape and contacts both the light source support member and the frame member is provided.

  According to such a configuration, it is possible to efficiently dissipate the heat of the electrode portion where heat is particularly likely to be accumulated in the rod-shaped light source by heat conduction through the light source support member, the heat conductive metal member, and the frame member. It becomes.

  In addition, since the light source support member is formed of an insulating material, it is possible to prevent an electrical influence from being generated between the light source support member and the rod-shaped light source or between the rod-shaped light sources adjacent to each other. Further, it becomes possible to further improve luminous efficiency and save labor.

  The surface light source device according to claim 3 is characterized in that, in claim 2, the heat radiating means of the light source support member has an uneven structure for increasing the surface area of the thermally conductive metal member.

  According to such a configuration, the surface area of the heat conductive metal member can be increased by the concavo-convex structure, so that the heat emissivity of the surface of the heat conductive metal member is improved and the heat of the rod-shaped light source is further effective. It is possible to dissipate heat.

  A surface light source device according to a fourth aspect is characterized in that, in any one of the first to third aspects, the heat dissipating means of the reflecting member has a ventilation hole formed in the reflecting member.

  And according to such a structure, it becomes possible to thermally radiate the heat inside the reflecting member heated by the heat generated by the rod-shaped light source to the outside of the reflecting member by convection through the air holes.

  The surface light source device according to claim 5 is characterized in that, in claim 4, a plurality of the ventilation holes are formed on a side wall portion of the reflecting member along the longitudinal direction of the rod-shaped light source.

  And according to such a structure, it becomes possible to thermally radiate the heat | fever of a rod-shaped light source still more effectively by increasing the number of ventilation holes.

  The surface light source device according to claim 6 is characterized in that, in claim 4 or claim 5, the total area of the ventilation holes is 0.1 to 5.0% of the area of the reflecting member. .

  And according to such a structure, while ensuring the surface area of a ventilation hole to some extent and maintaining heat dissipation efficiency, it prevents that the degree of the light leakage from an apparatus becomes large by the area of a ventilation hole becoming large too much. It becomes possible to do.

  A surface light source device according to a seventh aspect is characterized in that, in any one of the fourth to sixth aspects, a light leakage preventing means is disposed in the ventilation hole.

  According to such a configuration, light leakage from the ventilation hole can be reduced by the light leakage prevention means, and the luminance of the surface light source can be appropriately maintained.

  The surface light source device according to claim 8 is characterized in that, in claim 7, the light leakage prevention means is provided in the ventilation hole while securing the ventilation hole at a position close to the ventilation hole outside or inside the ventilation hole. It is in the point made into the plate-shaped part arrange | positioned so that it may oppose.

  And according to such a structure, it becomes possible to reduce effectively the light leakage from a ventilation hole, ensuring the heat dissipation through a ventilation hole by the plate-shaped part of a simple structure.

  The surface light source device according to claim 9 is characterized in that, in any one of claims 4 to 8, air blowing means for sending air inside the reflecting member to the outside of the reflecting member through the ventilation hole. It is in having.

  And according to such a structure, since the air inside the reflecting member warmed by the heat generation of the rod-shaped light source can be sent out to the outside of the reflecting member by the blowing means, the heat of the rod-shaped light source is radiated more efficiently. It becomes possible.

  The surface light source device according to claim 10 is characterized in that, in claim 9, the air blowing means is a rotary fan.

  And according to such a structure, it becomes possible to comprise a ventilation means at low cost with a simple rotation fan.

  A surface light source device according to an eleventh aspect is characterized in that, in any one of the second to tenth aspects, the heat dissipating means of the reflecting member has a white paint surface on an outer surface of the reflecting member. .

  And according to such a structure, since the heat | fever by a rod-shaped light source can be efficiently radiated | emitted as infrared rays from the white coating surface of a reflection member, it becomes possible to further improve the thermal radiation efficiency of a reflection member.

  The surface light source device according to a twelfth aspect of the present invention is that, in the eleventh aspect, the white painted surface is formed by using a white ceramic sintered material.

  And according to such a structure, it becomes possible to further improve the heat resistance of a reflection member.

  The surface light source device according to a thirteenth aspect is characterized in that, in any one of the first to twelfth aspects, the frame member includes a heat radiating means for radiating heat generated by lighting of the rod-shaped light source. In the point.

  And according to such a structure, since the heat | fever emitted by lighting of a rod-shaped light source can be radiated by the heat radiating means with which the frame member was equipped, the temperature rise of the surface light source device accompanying the heat_generation | fever of a rod-shaped light source is made still more effective. It becomes possible to reduce.

  The surface light source device according to claim 14 is characterized in that, in claim 13, the heat radiating means of the frame member is formed of a metal material and the frame member itself is formed on at least a part of the surface of the frame member. The unevenness structure is provided to increase the surface area of the member.

  According to such a configuration, the surface area of the holding frame can be increased by the concavo-convex structure, so that the heat emissivity of the surface of the holding frame can be improved and the heat of the rod-shaped light source can be radiated more effectively. It becomes.

  According to the surface light source device according to claim 1 of the present invention, even if the number of the rod-shaped light sources is increased, the temperature rise of the surface light source device due to the heat generation of the rod-shaped light source can be suppressed as much as possible. In the light source, the luminance can be improved and power saving can be achieved. Further, the product life can be improved by reducing the influence of heat acting on the light diffusing member and the like due to heat generation.

  According to the surface light source device according to claim 2, in addition to the effect of the surface light source device according to claim 1, the simple configuration makes it possible to improve the luminance and power consumption and improve the product life at a lower cost and efficiently. Can be achieved.

  According to the surface light source device according to the third aspect, in addition to the effect of the surface light source device according to the second aspect, it is possible to further effectively improve the luminance, save power, and improve the product life.

  According to the surface light source device according to claim 4, in addition to the effects of the surface light source device according to claims 1 to 3, the luminance of the surface light source can be improved more effectively and the power can be saved. And the product life can be improved.

  According to the surface light source device according to claim 5, in addition to the effect of the surface light source device according to claim 4, the brightness of the surface light source is improved more effectively, the power loss is reduced, and the product life is improved. Can do.

  According to the surface light source device according to claim 6, in addition to the effect of the surface light source device according to claim 4 or claim 5, the brightness of the surface light source, power saving, and product life are more effectively improved. be able to.

  According to the surface light source device according to claim 7, in addition to the effects of the surface light source device according to claims 4 to 6, a surface light source device that is more effective in luminance, power saving, and product life is realized. can do.

  According to the surface light source device according to the eighth aspect, in addition to the effect of the surface light source device according to the seventh aspect, the luminance of the surface light source is improved, the power is saved, and the product life is improved by a further inexpensive configuration. be able to.

  According to the surface light source device according to claim 9, in addition to the effects of the surface light source device according to claims 4 to 8, it is possible to further effectively improve the luminance of the surface light source and reduce power loss, Product life can be improved.

  According to the surface light source device according to the tenth aspect, in addition to the effect of the surface light source device according to the ninth aspect, the cost can be further reduced.

  According to the surface light source device of the eleventh aspect, in addition to the effects of the surface light source device according to the second to tenth aspects, the surface light source device can be more effectively improved in luminance, power saving, and product life. You can plan.

  According to the surface light source device of the twelfth aspect, in addition to the effect of the surface light source device of the eleventh aspect, the product life can be improved more effectively.

  According to the surface light source device of the thirteenth aspect, in addition to the effects of the surface light source device according to the first to twelfth aspects, the luminance can be improved more efficiently and the power can be saved and the product can be more efficiently produced by an inexpensive configuration. The lifetime can be improved.

  According to the surface light source device of the fourteenth aspect, in addition to the effect of the surface light source device according to the thirteenth aspect, the luminance of the surface light source can be improved, the power can be saved, and the product life can be improved. be able to.

  Hereinafter, embodiments of a surface light source device according to the present invention will be described with reference to FIGS. 1 to 9.

  As shown in FIG. 1, in the surface light source device 1 of the present embodiment, a plurality of substantially cylindrical rod-like light sources 2 are parallel on the same plane so as to have a predetermined interval in a direction orthogonal to the longitudinal direction. The plurality of rod-like light sources 2 constitute a substantially planar light source surface.

  As shown in FIG. 2, each rod-shaped light source 2 has electrode portions 3 at both ends in the longitudinal direction, and lead wires 4 are connected to the electrode portions 3.

  As the rod-like light source 2, a cold cathode tube is preferably used from the viewpoint of low power consumption and long life.

  A pair of light source support members 5 that collectively support both ends of the rod-shaped light sources 2 are disposed at both ends in the longitudinal direction of the plurality of rod-shaped light sources 2.

  In the state in which the rod-shaped light source 2 is supported by these light source support members 5, the electrode portion 3 is completely covered from the outer periphery by the light source support member 5. On the other hand, with respect to the lead wire 4 connected to the electrode part 3, the base end part side connected to the electrode part 3 is covered with the light source support member 5, but is connected to the power source. The side is drawn out of the light source support member 5 through a hole 5a (see FIG. 2) formed in the light source support member 5.

  A light diffusing member that diffuses and emits the light from the rod-shaped light source 2 toward the liquid crystal display unit (not shown) at a position facing the alignment surface of the plurality of rod-shaped light sources 2 in the upper part of FIG. 7 is disposed.

  Further, the plurality of rod-like light sources 2 are provided from the lower side and the four sides in FIG. 1 by a box-shaped reflecting member 9 including a low wall portion 9a and side wall portions 9b, 9c, 9d, and 9e surrounding the four sides of the low wall portion 9a. Covered.

  As shown in FIG. 3, the reflecting member 9 retains the shape of the reflecting member 9, and reflects the light from the rod-shaped light source 2 and the metal part 10 for maintaining the strength of the surface light source device 1. And a reflecting portion 11. Various metal materials can be appropriately selected as the metal part 10 according to the concept, but it is preferable to use aluminum or an aluminum alloy from the viewpoint of weight reduction and good thermal conductivity. On the other hand, the reflecting portion 11 is formed on the inner surface facing the rod-shaped light source 2 in the low wall portion 9a and the side wall portions 9b, 9c, 9d, 9e. A material having high reflectivity and excellent heat resistance is preferable. For example, a vapor deposition material such as a white plastic material, silver, and aluminum can be mentioned as a preferable material, and more preferably, a plastic material such as polyethylene terephthalate or polypropylene is foamed and whitened.

  Further, as shown in FIG. 1, of the side wall portions 9 b, 9 c, 9 d, and 9 e, a pair of side wall portions 9 b and 9 d that are orthogonal to the longitudinal direction of the rod-shaped light source 2 has a rod-shaped light source 2 on the lower end side. A long notch 12 is formed along the alignment direction, and both ends of the rod-like light source 2 are exposed to the outside of the reflecting member 9 together with the light source support member 7 through the notch 12.

  As shown in FIG. 4, instead of the notch portion 12, the pair of side wall portions 9 b and 9 d that are orthogonal to the longitudinal direction of the rod-shaped light source 2 are arranged at positions facing each other in the alignment direction of the rod-shaped light source 2. A plurality of through holes 22 may be formed at intervals, and both end portions in the longitudinal direction of each rod-shaped light source 2 may be passed through each through hole 22. In this case, the light source support member 5 supports the rod-shaped light source 2 outside the side wall portions 9b and 9d.

  Furthermore, the light source support member 5, the light diffusion member 7, and the reflection member 9 are integrally held by a frame member 14 shown in FIGS.

  In the present embodiment, the light source support member 5 and the reflection member 9 are provided with heat radiating means for radiating heat generated by the lighting of the rod-shaped light source 2, and by this heat radiating means, the rod-shaped light source 2. It is possible to dissipate heat generated when the lamp is turned on.

  Accordingly, the temperature rise of the surface light source device 1 due to the heat generation of the rod-shaped light source 2 can be reduced.

  The heat radiating means of the light source support member 5 is formed in such a shape that the light source support member 5 itself covers the electrode portion 3 and a part of the lead wire 4 with an insulating material, as shown in FIG. Thus, it is comprised by providing the heat conductive metal member 15 which contacts both the said light source support member 5 and the said frame member 14. As shown in FIG.

  Thereby, the heat of the electrode part 3 in which heat is particularly likely to be accumulated in the rod-shaped light source 2 can be efficiently radiated by heat conduction through the light source support member 5, the heat conductive metal member 15 and the frame member 14. It has become. In addition, since the light source support member 5 is made of an insulating material, it is possible to prevent an adverse electric effect from occurring between the light source support member 5 and the rod-shaped light source 2 or between the rod-shaped light sources 2 adjacent to each other. As a result, it is possible to further improve luminous efficiency and save labor.

  The insulating material is preferably a plastic material, and more preferably silicon rubber having excellent electric resistance, dielectric constant, and heat resistance.

  Moreover, as a material of the said heat conductive metal member 15, various metals excellent in heat conductivity, such as aluminum and copper, can be used.

  Further, as shown in FIG. 2, the heat radiating means of the light source support member 5 has a concavo-convex structure 16 for increasing the surface area of the thermally conductive metal member 15. The heat emissivity of the surface of the conductive metal member 15 is improved, and the heat of the rod-shaped light source 2 can be radiated more effectively.

  The concavo-convex structure 16 is not limited to a square wave shape in cross section, and various shapes such as a sawtooth wave shape and a sine wave shape can be considered. Further, the concavo-convex structure 16 does not necessarily need to be formed with a constant pitch in a predetermined direction, and is irregularly formed as long as it increases the surface area of the heat conductive metal member 15. It may be.

  In addition, as the concavo-convex structure 16, various structures such as a fin structure, a bowl structure, a fine satin structure, and a fine hairline structure can be employed.

  Further, the heat dissipating means of the reflecting member 9 has a ventilation hole 17 formed in the reflecting member 9, and the inside of the reflecting member 9 heated by the heat of the rod-shaped light source 2 through the ventilation hole 17. The heat of the air can be radiated to the outside of the reflecting member 9 by convection.

  In the present embodiment, a plurality of the ventilation holes 17 are formed in the side wall portions 9 c and 9 e along the longitudinal direction of the rod-shaped light source 2 in the reflection member 9. Therefore, the heat of the rod-shaped light source 2 can be radiated more effectively by the plurality of ventilation holes 17.

  The shape of the vent hole 17 may be any shape such as an ellipse as shown in FIG. 1, a circle as shown in FIGS. 3 and 4, a rectangle as shown in FIG. 5, or a trapezoid.

  Furthermore, in the present embodiment, the total area of the ventilation holes 17 is 0.1 to 5.0% of the area of the reflection member 9. If the total area of the vent holes is less than 0.1%, the heat dissipation effect is small, while if it exceeds 5.0%, the brightness of the surface light source, especially the brightness of the corners of the surface light source, becomes dark. is there. The total area of the ventilation holes 17 is preferably 0.5 to 2.0% of the area of the reflecting member 9. Furthermore, when light leakage prevention means is provided in the ventilation hole 17, the total area of the ventilation hole 17 can be increased.

  Thereby, while ensuring the surface area of the ventilation hole 17 to some extent and maintaining heat dissipation efficiency, it can prevent that the degree of the light leak from the apparatus 1 becomes large by the area of the ventilation hole 17 becoming large too much. It is like that.

  Further, the vent hole 17 may be provided with light leakage prevention means. In that case, the light leakage prevention means can reduce the light leakage from the ventilation hole 17 and maintain the luminance of the surface light source appropriately.

  Further, the light leakage prevention means, for example, as shown in FIG. 6 and FIG. 7 or FIG. 8 and FIG. 9, the ventilation hole 17 is located at a position close to the ventilation hole 17 on the outside or inside of the ventilation hole 17. It may be a plate-like portion 19 disposed so as to face the ventilation hole 17 so as to be secured.

  If the light leakage prevention means is configured in this manner, light leakage from the ventilation holes 17 can be effectively reduced while ensuring heat radiation through the ventilation holes 17 with a simple and inexpensive configuration.

  Although not shown, the surface light source device 1 may be provided with air blowing means for sending the air inside the reflecting member 9 to the outside of the reflecting member 9 through the ventilation holes 17.

  By doing so, since the air inside the reflecting member 9 heated by the heat generated by the rod-shaped light source 2 can be sent out to the outside of the reflecting member 9 by the blowing means, the heat of the rod-shaped light source 2 is radiated more efficiently. be able to.

  In the case where the air blowing means is provided, it is economically preferable to use a rotating fan having a simple and inexpensive configuration.

  The rotating fans of the air blowing means may be installed in close contact with the ventilation holes 17 or a small number of large capacity fans may be installed outside the ventilation holes 17.

  Furthermore, in the present embodiment, the heat dissipating means of the reflecting member 9 has a white painted surface 20 on the outer surface (the lower surface in FIG. 3) of the bottom wall portion 9a of the reflecting member 9.

  Thereby, since the heat by the rod-shaped light source 2 can be efficiently radiated as infrared rays from the white painted surface 20 of the reflection member 9, the heat dissipation efficiency of the reflection member 9 can be further improved.

  The white painted surface 20 is preferably formed by using a white ceramic sintered material. As a result, the heat resistance of the reflecting member 9 can be further improved.

  Specific methods for forming the white painted surface 20 include methods such as application of heat resistant paint, baking coating, or vapor deposition.

  Further, in the present embodiment, the frame member 14 is provided with a heat radiating means for radiating heat generated by the lighting of the rod-shaped light source 2, and the heat generated when the rod-shaped light source 2 is lit by the heat radiating means. Can be dissipated.

  Therefore, the temperature rise of the surface light source device 1 accompanying the heat generation of the rod-shaped light source 2 can be further effectively reduced.

  In addition, as shown in FIG. 1, the heat radiating means of the frame member 14 includes the frame member 14 itself formed of a metal material and a surface area of the frame member 14 on at least a part of the surface of the frame member 14. It is configured by providing a concavo-convex structure 21 for increasing the amount.

  Accordingly, since the surface area of the holding frame 14 can be increased by the uneven structure 21, the heat emissivity of the surface of the holding frame 14 can be improved and the heat of the rod-shaped light source 2 can be radiated more effectively. ing.

  As the concavo-convex structure 21, those having various shapes such as a rectangular wave shape in cross section can be selected similarly to the concavo-convex structure 16 of the thermally conductive metal member 15.

  Next, the operation of this embodiment will be described.

  When driving the surface light source device 1 according to the present embodiment, power is supplied to the plurality of rod-like light sources 2 from the power source such as an external power source or a battery via the lead wires 4 and the electrode portions 3. By turning on, each bar-shaped light source 2 is turned on.

  Of the light radiated from each rod-shaped light source 2 by turning on each rod-shaped light source 2, the light traveling in the direction of the light diffusing member 7 is diffused by the light diffusing member 7 and then is transmitted to the liquid crystal display unit side as planar light. Emitted. Of the radiated light from each rod-shaped light source 2, the light traveling in the direction of the reflecting member 9 is reflected by the reflecting member 9 in the direction of the light diffusing member 7, and then diffused by the light diffusing member 7. It is emitted to the liquid crystal display unit side as flat light.

  At this time, each bar-shaped light source 2 emits heat due to light emission of each bar-shaped light source 2, and this heat becomes particularly remarkable in the electrode portion 3 of each bar-shaped light source 2.

  However, the heat is generated from the light source support member 5 that supports the electrode unit 3, the heat conductive metal member 15 that contacts the light source support member 5, and a metal material that contacts the heat conductive metal member 15. By heat conduction through the frame portion 14, the heat is effectively radiated to the outside of the frame portion 14.

  Further, the heat of each rod-shaped light source 2 is more effectively dissipated by the uneven structure 16 of the thermally conductive metal member 15 and the uneven structure 21 of the frame portion 14.

  Further, the heat radiated in the space surrounded by the reflecting member 9 and the light diffusing member 7 due to the heat generated by the rod-shaped light source 2 can be appropriately radiated to the outside through the ventilation holes 17. At this time, the light leakage prevention means 19 is provided in each ventilation hole 17, so that light leakage from the ventilation hole 17 can be appropriately prevented.

  Thereby, the heat | fever emitted by lighting of the rod-shaped light source 2 can be thermally radiated, and the temperature rise of the surface light source device 1 accompanying the heat_generation | fever of the rod-shaped light source 2 can be reduced.

  As a result, in a large area surface light source, the luminance can be improved and the power loss can be reduced. Moreover, since the influence of the heat which acts on the light-diffusion member 7 grade | etc., Can be reduced, a product life can be improved.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
The surface light source device 1 of Example 1 constitutes a surface light source by aligning a total of 16 cold cathode tube lamps (manufactured by Harrison Toshiba Lighting) having a diameter of 2.6 mm as rod-shaped light sources 2.

  In Example 1, as the reflecting member 9, a Toray-made reflecting sheet E60L is attached to the inner surface of an aluminum frame (thickness 2 mm) having an inner size of 200 × 300 × 20 mm. In the pair of side wall portions 9b9d orthogonal to the lamp in the reflecting member 9, there are 16 through-holes 22 (see FIG. 4) having a diameter of 2.8 mm at a height of 7 mm from the low wall portion 9a at intervals of 12 mm. Individually formed.

  On the other hand, on the side wall portions 9c and 9e parallel to the longitudinal direction of the lamp in the reflecting member 9, 14 ventilation holes 17 each having a diameter of 6 mm are provided at intervals of 20 mm at positions 12 mm high from the low wall portion 9a. Is formed.

  The 16 lamps penetrate through the 16 through-holes 17, and both ends of each lamp cover the electrode part 3 and the lead wire 4 as a light source support member 5. A silicone resin having a thickness of 1 mm is disposed.

  Further, an N89 acrylic diffusion plate (2 mm thick) manufactured by Mitsubishi Rayon is disposed as the light diffusing member 7 on the reflecting member 9.

[Example 2]
In addition to the configuration of the surface light source device 1 of the first embodiment, the surface light source device 1 of the second embodiment is manufactured by applying a white paint 20 to the outer surface of the reflecting member 9.

[Example 3]
In the surface light source device 1 of Example 3, as the reflecting member 9, the one in which a reflection sheet E60L made by Toray is pasted on the inner surface of an aluminum frame (thickness 2 mm) having an inner size of 200 × 300 × 20 mm is used. ing.

  Further, as the light source support member 5, a 200 × 10 × 10 mm silicon rubber made of silicon rubber is used in which 16 holes 5a having a diameter of 2.6 mm are formed at intervals of 12 mm. Both ends of 16 cold cathode tube lamps having a diameter of 2.6 mm are inserted into the holes 5 a of the member 5.

  Further, around the light source support member 5, aluminum having a thickness of 2 mm is attached as the heat conductive metal member 15.

Further, on the lower end side of the side wall portions 9b and 9d of the reflecting member 9, as in the surface light source device 1 shown in FIG. 1, it extends along the lamp alignment direction over a height of 14 mm from the bottom wall portion 9a. A long notch 12 is formed, and the lamp projects outside the reflecting member 9 together with the light source support member 5 through the notch 12. About the other structure, the ventilation hole 17 and the white coating surface 20 are arrange | positioned similarly to Example 1,2.
[Comparative Example 1]

  The surface light source device of Comparative Example 1 is a surface light source device similar to the conventional one without any heat dissipating means.

  And about the surface light source device of Examples 1 thru | or 3 and the comparative example 1 which were produced in this way, a lamp is lighted by tube current 5mA (62KHz), and the sensor part of a thermocouple thermometer is hung in the center of a reflective member. The temperature increase after 30 minutes was measured. The room temperature was 25 ° C.

The results are shown in Table 1 below.

  As shown in Table 1, Example 1 was provided with only ventilation holes as a heat radiating means, but compared with Comparative Example 1, the in-frame temperature could be reduced by 10 ° C. or more.

  Further, in Example 2, the in-frame temperature could be further reduced by 5 ° C. by adding a white painted surface as a heat dissipating means to the configuration of Example 1.

  Furthermore, in Example 3, the in-frame temperature could be further reduced by 4 ° C. by adding a heat conductive metal member as a heat dissipation means to the configuration of Example 2.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed.

1 is a schematic exploded perspective view showing an embodiment of a surface light source device according to the present invention. In embodiment of the surface light source device which concerns on this invention, the expansion perspective view which shows the thermal radiation means of the light source support member In the embodiment of the surface light source device according to the present invention, a longitudinal sectional view showing an example of a ventilation hole as a heat radiating means of a reflecting member together with a rod-shaped light source FIG. 3 is a perspective view of the surface light source device according to the embodiment of the present invention. In the embodiment of the surface light source device according to the present invention, a perspective view showing another example of the ventilation hole as the heat radiating means of the reflecting member, together with the rod-shaped light source, different from FIG. The front view which shows an example of the light-shielding prevention means arrange | positioned by the ventilation hole in embodiment of the surface light source device which concerns on this invention 6 is a longitudinal sectional view of FIG. The front view which shows another example different from FIG. 7 of the light-shielding prevention means arrange | positioned in the ventilation hole in embodiment of the surface light source device which concerns on this invention Vertical sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surface light source device 2 Rod-shaped light source 3 Electrode part 4 Lead wire 5 Light source support member 7 Light diffusing member 9 Reflective member 14 Frame member 15 Thermally conductive metal member 16 Uneven structure 17 Ventilation hole 19 Plate-shaped part 20 White coating surface 21 Uneven structure

Claims (14)

A plurality of rod-shaped light sources each having an electrode portion connected to a lead wire at an end portion in the longitudinal direction and arranged in parallel in a planar shape, and a longitudinal end portion having the electrode portions in the plurality of rod-shaped light sources A light source supporting member to be supported, a light diffusing member that diffuses and emits light from each of the bar light sources, and a plurality of the bar light sources are disposed opposite to a plane in which the plurality of bar light sources are aligned. A surface light source device having a reflection member that guides the light to the light diffusion member, and a frame member that holds the light source support member, the light diffusion member, and the reflection member,
The surface light source device, wherein the light source support member and the reflection member include heat radiating means for radiating heat generated by lighting of the rod-shaped light source.   The heat radiating means of the light source support member is formed in a shape in which the light source support member covers the electrode portion and at least a part of the lead wire with an insulating material. The surface light source device according to claim 1, further comprising a thermally conductive metal member in contact with both.   The surface light source device according to claim 2, wherein the heat radiating means of the light source support member has a concavo-convex structure for increasing a surface area of the thermally conductive metal member.   4. The surface light source device according to claim 1, wherein the heat dissipating means of the reflecting member has a ventilation hole formed in the reflecting member. 5.   The surface light source device according to claim 4, wherein a plurality of the ventilation holes are formed in a side wall portion of the reflecting member along a longitudinal direction of the rod-shaped light source.   6. The surface light source device according to claim 4, wherein a total area of the ventilation holes is 0.1 to 5.0% of an area of the reflection member.   The surface light source device according to any one of claims 4 to 6, wherein light leakage prevention means is disposed in the ventilation hole.   The light leakage prevention means is a plate-like portion disposed so as to face the ventilation hole while securing the ventilation hole at a position close to the ventilation hole outside or inside the ventilation hole. 8. The surface light source device according to claim 7, wherein   9. The surface light source device according to claim 4, further comprising a blowing unit configured to send air inside the reflecting member to the outside of the reflecting member through the ventilation hole.   The surface light source device according to claim 9, wherein the blowing unit is a rotary fan.   The surface light source device according to any one of claims 2 to 10, wherein the heat dissipating means of the reflecting member has a white painted surface on an outer surface of the reflecting member.   The surface light source device according to claim 11, wherein the white painted surface is formed by using a white ceramic sintered material.   The surface light source device according to any one of claims 1 to 12, wherein the frame member includes a heat radiating means for radiating heat generated by lighting of the rod-shaped light source.   The heat radiating means of the frame member is formed of a metal material, and an uneven structure for increasing the surface area of the frame member is disposed on at least a part of the surface of the frame member. The surface light source device according to claim 13.