JP4243302B2 - Backlight device and liquid crystal display device using the same - Google Patents

Description

  The present invention relates to a backlight device and a liquid crystal display device using the same, and more particularly to a backlight device having a light source that generates heat, such as a fluorescent tube, and a liquid crystal display device using the same.

  Conventional display devices have been mainly CRT (cathode ray tube) displays, but in recent years, replacement with thin display devices using liquid crystal panels has been progressing. In recent years, the liquid crystal display device has been improved in display quality, and it is desired that the liquid crystal display device be increased in size and brightness for television applications. Therefore, a backlight device that illuminates the liquid crystal panel is also required to have higher luminance.

  Conventional liquid crystal display devices are mainly for so-called notebook personal computers, screen sizes are mainly up to about 13 inches, resolution is up to XGA, and screen brightness is up to 150 cd / m2. 1 and 2 show a liquid crystal display device 1A which is an example of this type.

  The liquid crystal display device 1A includes a liquid crystal panel 2A, a housing 5, a backlight device 10A, and the like. The housing 5 holds the liquid crystal panel 2 </ b> A and the backlight device 10 </ b> A via the resin frame 6 and the back plate 9. Further, the backlight device 10A irradiates the liquid crystal panel 2A from the back surface thereof, thereby giving a predetermined luminance to the display of the liquid crystal panel 2A.

The backlight device 10A generally supports the fluorescent tube 3 through a fluorescent tube 3 serving as a light source, a light guide plate 4 that guides light from the fluorescent tube to the liquid crystal panel 2A, and a rubber holder, and guides light from the fluorescent tube 3. It comprises a holder 7 etc. that reflects toward the light plate 4.
In the fluorescent tube 3, mercury is enclosed in Ar gas or Ne gas, and the fluorescent material is applied to the tube wall. Mercury gas generates ultraviolet rays during discharge, and the ultraviolet rays hit the fluorescent material to generate visible light.

  The light guide plate 4 is an acrylic resin plate and irradiates the entire surface of the liquid crystal panel 2A with light from the fluorescent tube 3 in cooperation with the optical sheet 8 attached thereto. In the liquid crystal display device 1A that has a small screen size (about 13 inches) and does not require much resolution and screen brightness as shown in the figure, the backlight device 10A is disposed only on one side of the light guide plate 4, Also, only one fluorescent tube 3 was provided.

On the other hand, in a liquid crystal display device 1B for a monitor as shown in FIGS. 3 and 4, a screen size of 15 inches is mainstream, a resolution of SXGA, and a screen luminance of about 250 cd / m 2 are required. For this reason, two backlight devices 10B incorporated in this type of liquid crystal display device 1B are arranged on both side surfaces so as to insert the light guide plate 4, and two fluorescent tubes 3 are arranged in each backlight device 10B. It has a configuration. However, a liquid crystal display device for a monitor is required to have a larger and brighter screen in order to cope with movie viewing and the like due to the widespread use of DVD drives for personal computers.
JP 2001-281658 A

  By the way, the fluorescent tube 3 provided in the backlight device 10B generates heat with light emission. In particular, the temperature rises sharply at both end positions of the fluorescent tube 3 provided with the fluorescent tube electrode portion, and when the supply current is increased to increase the luminance, the temperature may be 120 ° C. or higher. For this reason, some rubber holders having heat conductivity are used as rubber holders disposed at both ends of the fluorescent tube 3, and heat is radiated to the holder 7.

  However, the structure in which the heat generated in the fluorescent tube 3 is simply radiated to the holder 7 via the rubber holder cannot provide a sufficient heat dissipation effect, and the luminance of the fluorescent tube 3 is reduced, and the electrode portion and the wiring are connected. There is a problem that the solder to be connected melts. For this reason, although the thing made into the structure which improved the thermal radiation efficiency by enlarging the holder 7 is provided, the problem that liquid crystal display device 1A, 1B will enlarge will arise in this structure.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a backlight device that can efficiently dissipate heat generated by a light source and a liquid crystal display device using the backlight device.

In order to solve the above-described problems, the present invention is characterized by the following measures.
The invention according to claim 1 is an edge light type backlight device in which an electrode portion of a light source is held in a holder attached to a housing via a holding member. The projection is configured to project toward the housing and to be thermally connected to the housing, and the housing is provided with a housing portion for housing the projection so as to wrap the projection.

  In this invention, you may comprise so that a protrusion part may protrude in the attachment / detachment direction to the said housing | casing of the said holder. Moreover, you may comprise the said protrusion part so that it may protrude through the hole formed in the said holder.

  According to the above invention, the holding member is formed with the protruding portion that protrudes outward from the holder, and the protruding portion is configured to be thermally connected to the housing, so that the heat generated by the light source is protruded from the holder. The heat is conducted to the housing through the heat and is dissipated in the housing. As a result, it is possible to efficiently dissipate the heat generated by the light source, and the temperature rise of the light source can be reduced.

Moreover, according to the said invention, since the accommodating part provided in the housing | casing accommodates so that the protrusion part which protruded from the holder may be wrapped, the contact area of a protrusion part and a housing | casing (storage part) can be taken widely. For this reason, it becomes possible to raise more the thermal radiation efficiency with respect to a housing | casing from a protrusion part, and the temperature rise of a light source can be reduced more effectively.

A liquid crystal display device according to the invention of claim 2
LCD panel,
The backlight device according to claim 1 ;
The backlight device includes a light guide plate that is disposed on a side surface serving as a light incident surface and that emits light from the backlight device toward the liquid crystal panel.

  According to the above invention, since the heat generated by the light source is efficiently dissipated, the backlight device can realize high luminance, and thus can realize a good image display and realize a highly reliable liquid crystal display device. be able to.

  As described above, according to the present invention, various effects described below can be realized.

  According to the first aspect of the present invention, the heat generated from the light source is conducted from the holder to the housing through the protruding portion and is radiated in the housing, so that the heat generated from the light source can be efficiently radiated. Thus, the temperature rise of the light source can be reduced.

In addition, since the contact area between the protruding portion and the housing (housing portion) can be increased, the heat radiation efficiency from the protruding portion to the housing can be increased, and the temperature rise of the light source can be more effectively reduced. Can do.

In addition, according to the liquid crystal display device according to the second aspect of the present invention, the heat generated by the light source is efficiently dissipated, so that the backlight device can realize high brightness, and thus can perform good image display and is high. A liquid crystal display device having reliability can be realized.

Next, embodiments of the present invention will be described with reference to the drawings.
5 and 6 show a backlight device 20A and a liquid crystal display device 21A using the backlight device 20A according to the first embodiment of the present invention. The liquid crystal display device 21A includes a liquid crystal panel 22, a casing 25, a backlight device 20A, and the like. The housing 25 has a resin frame 26 inside, and the liquid crystal panel 22 is held by the resin frame 26. A back plate 29 is disposed below the resin frame 26, and a backlight device 20 </ b> A is disposed between the back plate 29 and the housing 25.

  The backlight device 20A irradiates the liquid crystal panel 22 from the back surface thereof, thereby giving the display of the liquid crystal panel 22 a predetermined luminance. In general, the backlight device 20A includes a light guide plate 24 and a fluorescent tube assembly 40A. The fluorescent tube assembly 40A includes a fluorescent tube 23, a holder 27, a rubber holder 32, and a wiring 33. The fluorescent tube assembly 40A is configured to be detachable from the main body of the backlight device 20A in terms of maintainability and the like.

  The fluorescent tube 23 is a cold cathode tube serving as a light source. In this embodiment, the two fluorescent tubes 23 are arranged in the fluorescent tube assembly 40A. The fluorescent tube 23 is configured such that mercury is sealed together with Ar gas and Ne gas in a glass tube, and a fluorescent material is applied to the tube wall.

In addition, fluorescent tube electrode portions 31 (not shown in FIG. 5; see FIG. 15) are provided at both ends of each fluorescent tube 23, and wiring 33 (connected to the fluorescent tube electrode portion 31 (see FIG. 15). 5 (not shown in FIG. 5; see FIG. 10) is configured to be pulled out to the outside.
Further, although the fluorescent tube electrode portion 31 is disposed at both ends of the fluorescent tube 23, as shown in FIG. 10, the wiring 33 is drawn only from one end and connected to the connector. For this reason, the wiring 33 connected to the fluorescent tube electrode part 31 on the side opposite to the drawer side is configured to be pulled out in the same direction by passing the back side of the holder 27.

  When the wiring 33 is energized, the fluorescent tube electrode section 11 is discharged, whereby the mercury gas generates ultraviolet rays, and the ultraviolet rays hit the fluorescent substance to generate visible light. The fluorescent tube 23 having the above configuration is provided with a rubber holder 32 at its end. The fluorescent tube 23 is held by the holder 27 through the rubber holder 32.

  The holder 27 is mainly formed of a metal material such as SUS, iron, or aluminum, and is provided long along the fluorescent tube 23. A silver vapor deposition layer or a white reflective layer is formed on the surface of the holder 27 facing the fluorescent tube 23, and the light from the fluorescent tube 23 is efficiently reflected. Thereby, the light of the fluorescent tube 23 is efficiently guided to the light guide plate 24 without being dispersed. As will be described later, the holder 27 also functions as a heat radiating member that radiates heat generated in the fluorescent tube 23.

  The rubber holder 32 is made of, for example, silicone rubber mixed with highly conductive metal powder as a filler, and has a high thermal conductivity. The rubber holder 32 is disposed at both ends of the fluorescent tube 23, that is, at a position where the fluorescent tube electrode portion 11 of the fluorescent tube 23 is provided. The rubber holder 32 has a function of holding the fluorescent tube 23 on the holder 27 as described above. Further, the rubber holder 32 is attached to the holder 27 so as to be thermally connected to the holder 27.

  The light guide plate 24 is formed of a highly transparent resin such as acrylic. The light guide plate 24 is disposed to face the back surface of the liquid crystal panel 22. Further, as shown in FIG. 6, the above-described fluorescent tube 23 is disposed so as to face the side surface (light incident surface) of the light guide plate 24.

  An optical sheet 28 is disposed on the surface side of the light guide plate 24 (side facing the liquid crystal panel 22). The optical sheet 28 condenses and diffuses light emitted from the light guide plate 24 and efficiently emits light to the liquid crystal panel 22. A reflective sheet 30 is disposed on the back side of the light guide plate 24. The reflection sheet 30 plays a role of reflecting light leaking from the light guide plate 24 and returning the light to the inside of the light guide plate 24 again.

  Next, the structure of the holder 27, which is a main part of the present embodiment, will be described mainly with reference to FIG. The holder 27 according to the present embodiment is characterized in that a proximity portion 41 is formed so that two fluorescent tubes 23 (light sources) are close to adjacent portions.

  The proximity portion 41 is formed by bracing the holder 27, and thus can be formed collectively when the holder 27 is formed. For this reason, even if the proximity part 41 is formed in the holder 27, the manufacturing process and assembly process of the backlight device 20A are not complicated.

  By the way, in the fluorescent tube assembly 40A, the temperature rises most by the heat generation of the fluorescent tube 23 at a position where the fluorescent tubes 23 which are heating elements face each other, that is, a position where each fluorescent tube 23 is adjacent. In the present embodiment, the proximity portion 41 formed on the holder 27 that also functions as a heat radiating member as described above is configured so as to be close to the position where the fluorescent tube 23 that tends to become high temperature faces.

  With this configuration, the distance between the fluorescent tube 23 and the holder 27 is reduced, and the heat generated in the fluorescent tube 23 is efficiently radiated to the holder 27 via the proximity portion 41. The rise can be reduced. In particular, as described above, the proximity portion 41 absorbs heat at a portion where the temperature rises most due to heat generation of the fluorescent tube 23 and dissipates it by the holder 27, so that it is possible to reliably prevent a decrease in luminance of the fluorescent tube 23 due to heat. it can. Further, by performing heat dissipation as described above, the temperature rise of the light guide plate 24 by the fluorescent tube 23 is suppressed, and thus it is possible to reliably prevent the light guide plate 24 from being deformed or melted.

  Further, as described above, according to the backlight device 20A according to the present embodiment, the heat generated in the fluorescent tube 23 is efficiently dissipated, so that high luminance can be realized. Therefore, according to the liquid crystal display device 21A using the backlight device 20A, it is possible to perform high-brightness and good image display and realize high reliability.

  In this embodiment, the backlight device 20A having two fluorescent tubes 23 is described as an example. However, the present invention is also applied to a backlight device having a configuration in which one or three or more fluorescent tubes 23 are provided. Of course, the invention according to the example can be applied.

  Further, in the present embodiment, the proximity portion 41 is formed at the center position of the pair of adjacent fluorescent tubes 23. However, when the temperature distribution in the fluorescent tube assembly is known, the temperature rises from this temperature distribution. It is effective to form the proximity portion 41 so as to be close to a site where it is likely to occur.

Next, a second embodiment of the present invention will be described.
FIG. 7 shows a backlight device 20B according to a second embodiment and a liquid crystal display device 21B using the same. In FIG. 7, the same components as those shown in FIGS. 5 and 6 used in the description of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The same applies to the description after the third embodiment described later and the drawings used for this description.

  Similar to the first embodiment, the backlight device 20B according to the present embodiment has the proximity portion 41 so as to be close to a portion where the temperature rise is likely to occur in the fluorescent tube assembly 40B, that is, an intermediate position between the pair of fluorescent tubes 23. Is formed. The present embodiment is characterized in that the wiring 33 of the fluorescent tube 23 is disposed at a position opposite to the side of the proximity portion 41 facing the fluorescent tube 23 (hereinafter, this position is referred to as a back surface position). is there.

  As described above, among the wirings connected to the fluorescent tube electrode part 31, the wiring 33 connected to the fluorescent tube electrode part 31 on the side opposite to the lead-out side is drawn out in the same direction by passing through the back side of the holder 27. It is configured. In this embodiment, the wiring 33 disposed on the back surface side of the holder 27 is disposed at the back surface position of the proximity portion 41.

  With this configuration, the backlight device 10B can be made compact. That is, as described above, the proximity portion 41 is configured to be close to the high-heat portion of the fluorescent tube 23, so that a space portion is generated at the back position. Then, by providing the wiring 33 connected to the fluorescent tube electrode portion 31 on the opposite side to the drawer side in the space portion, the backlight device 20B has a configuration compared to the configuration in which the wiring 33 is provided in other portions. Compactness can be achieved.

  The proximity portion 41 has a function of dissipating heat generated in the fluorescent tube 23 and thus becomes high temperature. However, since a heat-resistant material is used as the covering material for the wiring 33, the covering material for the wiring 33 is It does not melt and expose the internal metal wires.

Next, a third embodiment of the present invention will be described.
FIG. 8 shows a liquid crystal display device 21C according to the third embodiment and a liquid crystal display device 21C using the same.

  10C according to the present embodiment has a configuration in which three fluorescent tubes 23 (hereinafter, referred to as fluorescent tubes 23A to 23C when specifically described) are provided in order to achieve high luminance. In the present embodiment, among the three or more fluorescent tubes 23A to 23C, the central fluorescent tube 23B is disposed so as to be close to the holder 27 with respect to the positions of the other fluorescent tubes 23A and 23C. It is characterized by that. The arrangement positions of the fluorescent tubes 23A to 23C can be set to arbitrary positions relatively easily by changing the formation positions of the holding holes of the fluorescent tubes 23A to 23C formed in the holder 27.

  By the way, when a plurality of fluorescent tubes are provided, the fluorescent tube located at the center has the highest temperature rise. That is, in the configuration in which the three fluorescent tubes 23A to 23C are arranged as in the present embodiment, the fluorescent tube 23B located at the center has the highest temperature.

  Therefore, in this embodiment, the fluorescent tube 23B, which is likely to be the highest temperature, is arranged close to the holder 27. Thereby, the heat of the fluorescent tube 23B having the highest temperature is more efficiently conducted to the holder 27 than from the other fluorescent tubes 23A and 23C. Therefore, it is possible to efficiently dissipate heat generated in the fluorescent tube 23B that is particularly high in temperature to the holder 27, and it is possible to suppress an increase in temperature of the backlight device 20C as a whole.

  In this embodiment, the three fluorescent tubes 23A to 23C are provided in the fluorescent tube assembly 40C. However, the application of this embodiment is not limited to this, and there are four or more fluorescent tubes. Of course, the present embodiment can be applied even in this case.

Next, a fourth embodiment of the present invention will be described.
FIG. 9 shows a liquid crystal display device 21D according to the fourth embodiment and a liquid crystal display device 21D using the same. In the present embodiment, the distance between the holder 27A and the fluorescent tube 23 constituting the fluorescent tube assembly 40D is such that the fluorescent tube electrode portion 31 of the fluorescent tube 23 is formed from the central position of the fluorescent tube 23 (hereinafter, both end positions). It is characterized by being configured to gradually become smaller.

  Specifically, since the diameter dimension of the fluorescent tube 23 is the same throughout, the width dimension at the center position of the holder 27A (indicated by the arrow A1 in the figure) is the width dimension at the both end positions (in the figure, the arrow A2). (Shown by). With this configuration, the distance between the fluorescent tube 23 and the holder 27A at both end positions (in the drawing, the distance between the fluorescent tube 23 and the holder 27A in the central portion (indicated by an arrow a1 in the drawing)). (Indicated by arrow a2) can be reduced (a1> a2).

  As described above, in the backlight device 20D according to the present embodiment, the separation distance between the holder 27A and the fluorescent tube 23 is configured to gradually decrease from the central position of the fluorescent tube 23A toward the both end positions. The heat radiation efficiency of the fluorescent tube 23 by 27A increases from the central position toward both end positions. As a result, the difference in heat distribution between the central portion and the both end positions is reduced as a result, and luminance unevenness in the backlight device 20D can be reduced.

  Further, with the above configuration, when the fluorescent tube assembly 40D is inserted into and removed from the housing 25, the insertion operation can be facilitated. That is, in the backlight device 20D according to the present embodiment, both ends of the fluorescent tube assembly 40D (that is, both ends of the holder 27A) have a narrow width dimension A2. On the other hand, the width dimension of the insertion hole of the fluorescent tube assembly 40D provided in the housing 25 needs to be matched with the width dimension A1 of the center portion of the holder 27 and is formed widely.

  For this reason, when the fluorescent tube assembly 40D is inserted into the housing 25, the width A2 and the narrow end are inserted into the width A1 (or larger) and the wide insertion opening. That's fine. For this reason, the process of inserting and removing the fluorescent tube assembly 40D with respect to the housing 25 can be easily performed.

Next, a fifth embodiment of the present invention will be described.
10 to 13 show a liquid crystal display device 21E according to the fifth embodiment and a liquid crystal display device 21E using the same.

  FIG. 10 is an exploded perspective view of a liquid crystal display device 21E according to the fifth embodiment. As shown in the figure, the liquid crystal display device 21E according to the present embodiment has a configuration in which a liquid crystal panel 22 is mounted on a backlight device 20E and a casing 25 is disposed on the upper portion thereof. Further, the backlight device 20E according to the present embodiment is also configured such that the fluorescent tube assembly 40E can be inserted and removed. A data substrate 34 and a gate substrate 35 are disposed on the side piece of the liquid crystal panel 22.

  FIG. 11 is an exploded perspective view showing the backlight device 20E in an enlarged manner.

  The backlight device 20E according to the present embodiment includes a light guide plate 24, an optical sheet 28, and a reflection sheet in a housing (housing) constituted by a frame 37 positioned at an upper portion and a lower metal plate 46 positioned at a lower portion. 30 is provided. In addition, the fluorescent tube assembly 40E is also inserted into the housing. For this reason, an insertion recess 38 is formed in the frame 37, and a guide recess 49 is formed in the connector 36.

  Further, a bent portion 48 is formed at one end of the guide concave portion 49 of the lower sheet metal 46. The bent portion 48 is integrated with the lower sheet metal 46 and is formed simultaneously with the formation of the guide recess 49 and the side plate portion 47. As a material for the lower metal plate 46, a metal material having high thermal conductivity is selected.

  Here, attention is focused on the insertion direction end (the left direction end in the drawing) of the fluorescent tube assembly 40E. Then, in the fluorescent tube assembly 40E used in the present embodiment, as shown in an enlarged view in FIG. 12, the rubber holder 32A that holds the fluorescent tube 23 on the holder 27B is outside the bent portion (folded portion) of the holder 27B. 48 (the side facing 48) (hereinafter, the portion projecting from the end 42 of the rubber holder 32A is referred to as a first projecting portion 44).

  On the other hand, paying attention to the insertion direction reverse end portion (the right direction end portion in the figure) of the fluorescent tube assembly 40E, in this embodiment, as shown in an enlarged view in FIG. 13, the side plate portion 47 (lower sheet metal 46) of the holder 27B. A through hole 43 is formed at a position opposite to the surface, and a part of the rubber holder 32B protrudes from the through hole 43 (hereinafter, a portion protruding from the through hole 43 of the light guide plate 4 liquid crystal panel 2B is referred to as a portion). 2nd protrusion 45).

  In the backlight device 20 </ b> E configured as described above, when the fluorescent tube assembly 40 </ b> E is inserted to a predetermined mounting position in the housing constituted by the frame 37 and the lower metal plate 46, the first protrusion 44 is formed on the lower metal plate 46. By being in contact with the bent portion 48, it is thermally connected. Further, the second projecting portion 45 is thermally connected by contacting the side plate portion 47 of the lower metal plate 46.

  Thereby, the heat generated in the fluorescent tube 23 is radiated by the holder 27B, and is also conducted and radiated to the lower sheet metal 46 through the first and second protrusions 44 and 45. Specifically, the rubber holder 32 </ b> A and the lower metal plate 46 are thermally connected by the first projecting portion 44 and the bent portion 48 contacting each other at the insertion direction end (left end in the drawing). Is done. Further, at the opposite end in the insertion direction (right end in the figure), the rubber holder 32B and the lower metal plate 46 are thermally connected by the second protrusion 45 and the side plate 47 coming into contact with each other.

  Therefore, the heat generated in the fluorescent tube 23 can be efficiently radiated, and the temperature rise of the fluorescent tube 23 can be reduced. In particular, since the first protrusion 44 and the second protrusion 45 are disposed at both ends of the fluorescent tube 23 where the temperature becomes highest, the fluorescent tube 23 can be cooled effectively.

  Further, in the present embodiment, when the fluorescent tube assembly 40E is inserted, the first protrusion 44 that does not slide in contact with the side plate portion 47 is disposed at the back of the fluorescent tube assembly 40E in the insertion direction (left end portion in the drawing). The second projecting portion 45 slidably in contact with the side plate portion 47 is arranged at a position in front of the insertion direction of the fluorescent tube assembly 40E (right end portion in the figure). As a result, the sliding contact distance between the second protrusion 45 and the side plate 47 when the fluorescent tube assembly 40E is inserted and removed can be shortened, whereby the wear of the second protrusion 45 can be prevented.

  Further, in the above-described embodiment, as shown in FIG. 13, the side plate portion 47 facing the second projecting portion 45 is flat. However, as shown in FIG. 14, when the fluorescent tube assembly 40E is mounted at a predetermined mounting position, the storage recess 50 may be formed at a predetermined position of the side plate portion 47 facing the second protrusion 45.

  As shown in FIG. 14B, the storage recess 50 has a shape that can be stored so as to wrap the second protrusion 45. By forming the storage recess 50 in the side plate portion 47 in this way, the contact area between the second protrusion 45 and the storage recess 50 is widened, so that the heat dissipation efficiency from the second protrusion 45 to the lower sheet metal 46 is further increased. Thus, the temperature rise of the fluorescent tube 23 can be more effectively reduced.

Next, a sixth embodiment of the present invention will be described.
15 to 17 show a liquid crystal display device according to a sixth embodiment and a fluorescent tube assembly 40F mounted on the liquid crystal display device. As shown in FIG. 17, the fluorescent tube assembly 40F according to the present embodiment is configured such that a heat radiating piece 51 is interposed between the rubber holder 32 and the light guide plate 24, and the heat radiating piece 51 is connected to the holder 27C. It is configured to be thermally connected.

  In this embodiment, as shown in FIG. 15, the heat dissipating piece 51 is integrally provided at the end of the holder 27C. And after attaching the wiring 33 previously connected to the fluorescent tube 23 and the flange 36 to the rubber holder 32 and attaching this to the holder 27C, as shown in FIG. 16, the heat radiating piece 51 is bent in the direction of the arrow, Thus, the rubber holder 32 is configured to be surrounded by the holder 27C and the heat radiating piece 51. Therefore, when the fluorescent tube assembly 40F is attached to the housing (not shown) of the backlight device, the heat dissipating piece 51 is interposed between the rubber holder 32 and the light guide plate 24.

  Thus, by providing the heat dissipating piece 51 thermally connected to the holder 27 </ b> C between the rubber holder 32 and the light guide plate 24, the heat generated in the fluorescent tube 23 is conducted from the rubber holder 32 to the light guide plate 24. This is no longer the case, and heat is radiated to the holder 27C through the heat radiating piece 51. Thereby, the light guide plate 24 can be prevented from being damaged by the heat generated in the fluorescent tube 23, and a highly reliable backlight device can be realized.

  Further, as described above, in the present embodiment, since the heat dissipating piece 51 is formed integrally with the holder 27C, the number of parts can be reduced. Further, since the heat radiating piece 51 is integrated with the holder 27C, heat conduction from the heat radiating piece 51 to the holder 27C can be performed more efficiently.

Next, a seventh embodiment of the present invention will be described.
18 to 19 show a liquid crystal display device according to a seventh embodiment and a fluorescent tube assembly 40G mounted on the liquid crystal display device.

  In the sixth embodiment described above, the heat radiating piece 51 is formed integrally with the holder 27C. On the other hand, this embodiment is characterized in that the heat radiating member 52 is configured by a U-shaped clip member (hereinafter, this heat radiating member is referred to as a heat radiating clip 52). The heat dissipating clip 52 is made of a metal material having good thermal conductivity and elasticity.

  Therefore, the heat dissipating clip 52 is configured to be detachable from the holder 27. According to this configuration, the heat radiating clip 52 can be easily attached to and detached from the holder 27, and assembling and maintenance can be improved.

Next, an eighth embodiment of the present invention will be described.
20 to 23 show a liquid crystal display device according to an eighth embodiment and a fluorescent tube assembly 40H mounted on the liquid crystal display device.

  The fluorescent tube assembly 40H according to the present embodiment is characterized in that the rubber holder 32C has an insulating property and an insulating protrusion 53 is formed on the rubber holder 32C. The insulating protrusion 53 is integrated with the rubber holder 32C, and is formed so as to be interposed between the fluorescent tube electrode portion 31 of the fluorescent tube 23 and the holder 27 as shown in FIGS. Yes. Further, the insulating projection 53 is formed only at a position facing the holder 27 and is not formed at a position facing the light guide plate 24 (see FIGS. 20 and 22).

  By the way, the holder 27 is made of a metal material as described above, and a high value current flows through the fluorescent tube electrode portion 31 in order to generate a discharge. For this reason, there is a possibility that discharge occurs between the fluorescent tube electrode portion 31 and the holder 27. In particular, in order to increase the brightness, it is necessary to further increase the current value, and the discharge is more likely to occur. When this discharge occurs, metal deposits are generated by sputtering on the inner wall of the fluorescent tube 23, so that the fluorescent tube 23 is significantly deteriorated and the reliability of the backlight device is lowered.

  On the other hand, the insulating protrusion 53 is formed on the rubber holder 32C having insulation as in the present embodiment, and the insulating protrusion 53 is interposed between the fluorescent tube electrode portion 31 and the holder 27. Thus, the path for generating the discharge becomes longer as shown by the arrow in FIG. 23, and thus the generation of the discharge can be suppressed. Thereby, the safety | security and reliability of a backlight apparatus can be improved.

  Further, in this embodiment, the insulating projection 53 is formed only at a position facing the holder 27 (that is, a region where a discharge may occur between the fluorescent tube electrode 31 and the holder 27). Thus, it is possible to prevent the insulating projection 53 from blocking the light toward the light guide plate 24 of the fluorescent tube 23. Therefore, even if the insulating protrusion 53 is provided to prevent discharge, the luminance of the backlight device can be prevented from decreasing.

It is a figure for demonstrating the liquid crystal display device of the small screen size which mounts the backlight apparatus which is a prior art example. It is a figure which expands and shows the part shown by arrow A1 in FIG. It is a figure for demonstrating the liquid crystal display device of the big screen size which mounts the backlight apparatus which is a prior art example. It is a figure which expands and shows the part shown by arrow A 2 in FIG. 1 is a perspective view showing a liquid crystal display device and a backlight device according to a first embodiment of the present invention. It is principal part sectional drawing which shows the liquid crystal display device and backlight apparatus which are 1st Example of this invention. It is principal part sectional drawing which shows the liquid crystal display device and backlight apparatus which are 2nd Example of this invention. It is principal part sectional drawing which shows the liquid crystal display device which is 3rd Example of this invention, and a backlight apparatus. It is a top view which shows the liquid crystal display device which is 4th Example of this invention, and a backlight apparatus. It is a disassembled perspective view which shows the liquid crystal display device which is 5th Example of this invention. It is a disassembled perspective view which shows the backlight apparatus which is 5th Example of this invention. It is a perspective view which expands and shows the principal part of the backlight apparatus which is 5th Example of this invention (the 1). It is a perspective view which expands and shows the principal part of the backlight apparatus which is 5th Example of this invention (the 2). It is a perspective view which expands and shows the principal part of the backlight apparatus which is 5th Example of this invention (the 3). It is a disassembled perspective view which shows the principal part of the fluorescent tube assembly provided in the liquid crystal display device which is 6th Example of this invention, and a backlight apparatus. It is a perspective view which shows the principal part of the fluorescent tube assembly provided in the liquid crystal display device which is 6th Example of this invention, and a backlight apparatus. It is sectional drawing which shows the principal part of the fluorescent tube assembly provided in the liquid crystal display device which is 6th Example of this invention, and a backlight apparatus. It is a disassembled perspective view which shows the principal part of the fluorescent tube assembly provided in the liquid crystal display device which is 7th Example of this invention, and a backlight apparatus. It is sectional drawing which shows the principal part of the fluorescent tube assembly provided in the liquid crystal display device which is 7th Example of this invention, and a backlight apparatus. It is a perspective view which shows the principal part of the fluorescent tube assembly provided in the liquid crystal display device which is 8th Example of this invention, and a backlight apparatus. It is a front view which shows the principal part of the fluorescent tube assembly provided in the liquid crystal display device which is 8th Example of this invention, and a backlight apparatus. It is sectional drawing which shows the principal part of the fluorescent tube assembly provided in the liquid crystal display device which is 8th Example of this invention, and a backlight apparatus. It is a figure which expands and shows the vicinity of an insulation protrusion part.

Explanation of symbols

20A-20E Backlight devices 21A-21E Liquid crystal display device 22 Liquid crystal panels 23A-23C Fluorescent tube 24 Light guide plate 25 Housing 27, 27A-27C Holder 31 Fluorescent tube electrode part 32, 32A-32C Rubber holder 33 Wiring 40A-40H Fluorescent tube Assembly 41 Proximity part 43 Through-hole 44 1st protrusion 45 2nd protrusion 46 Lower sheet metal 47 Side plate part 48 Bending part 50 Storage part 51 Heat radiation piece part 52 Heat radiation clip 53 Insulation protrusion part

Claims (2)

In the edge light type backlight device in which the electrode portion of the light source is held through a holding member in a holder attached to the housing,
Projecting outward from the holder to the holding member, and forming a protrusion configured to be thermally connected to the housing;
A backlight device, wherein the housing is provided with a housing portion for housing the projecting portion. LCD panel,
Comprising the backlight device according to claim 1,
The backlight device is a liquid crystal display device using a backlight device, wherein a light source is disposed on a side surface of a light guide plate.

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