JP2002072202A - Backlight device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a backlight device used as an illuminator for liquid crystal display device in respective items of heat radiating property, workability, reliability and productivity. SOLUTION: In the backlight device for liquid crystal display device equipped with a light guide plate 12 having an incident plane 21 on which a light ray from a fluorescent tube 14 is made incident and a light-emitting surface 40 from which the incident light ray is emitted, a fluorescent tube assembly 11C having the fluorescent tube 14, a fluorescent tube holding member 16A and a reflector 15A arranged therein and a heat radiation plate 13 on which the fluorescent tube assembly 11C and the light guide plate 12 are mounted and which radiates heat generated by the fluorescent tube 14, a heat introducing part 17, placed between the fluorescent tube holding member 16A and the light guide plate 12, is formed on the heat radiation plate 13. Furthermore, the heat introducing part 17 is constructed so as to be thermally connected with the fluorescent tube holding member 16A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device, and more particularly to a backlight device used as a lighting device for a liquid crystal display device.

In general, as a means for improving the visibility of a liquid crystal display device, a configuration in which a light source (backlight) is provided on the back side of the display surface of the liquid crystal display device is known.

[0003] In recent years, liquid crystal display devices have been mounted on various electronic devices such as computers and portable terminal devices, and thus improvement in visibility is desired. In order to improve the visibility of the liquid crystal display device, it is necessary to use a bright backlight.

[0004] Therefore, it is desired that the backlight device has high luminous efficiency. Further, since the light source of the backlight device generates heat, it is necessary to improve the cooling efficiency, and it is also important that the assembling property and the maintenance property are good.

[0005]

2. Description of the Related Art FIGS. 1 to 4 show a backlight device 100A as a first conventional example. FIG. 1 is an enlarged sectional view showing the vicinity of the fluorescent tube assembly 111A of the backlight device 100A, and FIG.
FIG. 3A is an exploded perspective view of FIG.
A is an external view of FIG.
It is an exploded perspective view which expands and shows A.

As shown in each figure, the backlight device 10
0A is generally composed of a fluorescent tube assembly 111A, a light guide plate 112, a radiator plate 113, and the like. The backlight device 100A functions as, for example, a backlight of a liquid crystal display device.

The fluorescent tube assembly 111A includes a fluorescent tube 114, a reflector 115,
And a fluorescent tube holding member 116A.
In the example shown in the drawing, two fluorescent tubes 114 are provided, and both ends of each fluorescent tube 114 are held by a fluorescent tube holding member 116A. This fluorescent tube holding member 1
A connection electrode (both not shown) to which a wiring is connected is provided inside 16A. The electrodes of the fluorescent tube 114 are electrically connected by soldering to the connection electrodes.

The reflector 115 is a fluorescent tube 114
And a function of reflecting the light generated by the fluorescent tube 114 to guide the light from the opening 137 to the incident surface 121 of the light guide plate 112 described later. This reflector 1
By providing the light guide 15, the light generated by the fluorescent tube 114 can be efficiently incident on the light guide plate 112. The reflector 115 has a fluorescent tube holding member 116A fixed to both ends thereof, whereby the fluorescent tube holding member 1A is fixed.
It also has a function of holding each fluorescent tube 114 via 16A.

The light guide plate 112 has a flat plate shape and is made of, for example, a light transmitting resin such as an acrylic resin. The side surface of the light guide plate 112 is the fluorescent tube assembly 1.
11A is an incident surface 121 on which light from 11A is incident;
Further, the upper surface has an emission surface 1 for emitting light to a liquid crystal display device or the like.
17 is set. The light incident from the incident surface 121 travels while being reflected in the light guide plate 112, and is emitted to the outside from the emission surface 117 under a predetermined reflection condition.
Therefore, light having substantially uniform light intensity is emitted from the emission surface 117 toward the liquid crystal display device or the like.

The heat radiating plate 113 is formed of a metal having high thermal conductivity. The heat radiating plate 113 has two functions: a function as a housing in which the fluorescent tube assembly 111A and the light guide plate 112 are mounted, and a function to radiate heat generated in the fluorescent tube 114. As shown in FIG. 2, a locking piece 119 and a side wall 120 are formed on the heat sink 113. The locking piece 119 is the light guide plate 1
The light guide plate 112 is attached to the heat radiating plate 113 by being formed at a position corresponding to the notch 118 formed on the fin 12 and engaging the locking piece 119 with the notch 118.

When the light guide plate 112 is attached to the heat radiating plate 113, the incident surface 121 of the light guide plate 112 is
A space is formed between the heat dissipation plate 113 and the side wall 120 (hereinafter, this space is referred to as a mounting space). Each fluorescent tube assembly 11A is configured to be mounted in the mounting space. When installing this,
Each fluorescent tube assembly 111A is slidably mounted in the mounting space in the direction indicated by arrow X1 in FIG. 3 or the direction indicated by arrow X2. Further, the fluorescent tube assembly 111A
Is configured so that it can be attached to and detached from the mounting space, thereby improving the maintenance.

FIGS. 5 and 6 show a backlight device 100B as a second conventional example. The backlight device 100B shown in FIG. 1 is configured to be integrated with the liquid crystal display device 130. In FIGS. 5 and 6, the same components as those described with reference to FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof is omitted.

The liquid crystal display device 130 includes a housing 131.
And a liquid crystal panel 133. Also,
The backlight device 100B is configured to be disposed below the liquid crystal panel 133. For this reason, a backlight mold 135 (shown in satin in FIG. 6) is provided in the housing 131, and the backlight device 100B
Is held by the backlight mold 135.

Further, as shown in FIG. 5, the fluorescent tube assembly 111B is configured to be attachable to and detachable from the housing 131, thereby improving maintainability. For this reason, a mounting hole 134 for mounting and dismounting the fluorescent tube assembly 11B is formed in the backlight mold 135.

[0015]

However, the conventional backlight devices 100A and 100B having the above-described structure are used.
In this case, there were the following problems in heat dissipation, workability and reliability, and productivity.

First, a problem concerning heat dissipation will be described.

At present, the liquid crystal display device is required to have a larger screen and higher brightness. However, in order to enlarge the screen, the length of the fluorescent tube 114 needs to be increased.
The tube voltage of 14 also needs to be set higher due to its characteristics. In order to simply increase the brightness of the screen, a fluorescent tube 11 is required.
It is necessary to increase the tube current of No. 4 and increase the light amount of the fluorescent tube 114.

Generally, fluorescent tube assemblies 111A, 1
As the fluorescent tube 114 used for the 11B, a cold-cathode tube type fluorescent tube is often used, but this cold-cathode tube requires a large amount of electric power (= cathode drop voltage × tube current) near the cathode when emitting electrons. And This power is often called reactive power and is mostly converted to heat.

Therefore, when the screen is enlarged and the brightness is increased, the cathode drop voltage and the tube current, which are the main components of the tube voltage, are inevitably increased. As a result, heat is generated at the end of the fluorescent tube as the cathode. It gets bigger. When this heat generation becomes large, the fluorescent tube electrode terminal portion (that is, the fluorescent tube holding member 1)
The temperature of the fluorescent tube holding member 11 increases.
Creep occurs in the solder connecting the connection electrode and the wiring disposed in the wiring 6, and the connection reliability is significantly reduced.

Generally, the creep phenomenon starts gradually from about 0.5 times the melting point temperature of the material. However, in the case of ordinary solder, when the melting point temperature is 183 ° C., the creep phenomenon starts to occur at about 91.5 ° C. Experiments have also shown that when the solder temperature rises above 100 ° C., the creep phenomenon begins to appear remarkably. As described above, when the temperature of the fluorescent tube electrode terminal portion (the fluorescent tube holding member 116) rises and becomes high, the light guide plate 112 which is a peripheral member of the fluorescent tube electrode terminal is provided.
There is a possibility that thermal deformation and thermal deterioration may occur in resin molded members such as the fluorescent lamp holding member 116 and the like. To prevent this,
It is necessary to efficiently radiate the heat generated at the end of the fluorescent tube 114. For this reason, the backlight device 100A includes:
A heat sink 113 is provided.

However, as shown in FIG. 1 and FIG. 3, in the conventional backlight device 100A, as shown in FIG. (The side wall portion 120) was not configured to be in contact, but was configured to be in contact via the reflector 115. Furthermore, as described above, the fluorescent tube assembly 111A is detachable from the mounting space (the space between the side wall 120 of the heat sink 113 and the incident surface 121 of the incident surface 121) from the viewpoint of improving the maintenance. It is necessary to

For this reason, the reflector 115 cannot be strongly pressed directly against the side wall 120 of the heat sink 113 (because it cannot be attached or detached).
15 and the heat radiating plate 113 have low adhesion, and the contact thermal resistance is considerably large. Therefore, the heat generated in the fluorescent tube 114 cannot be efficiently conducted to the heat radiating plate 113. Therefore, even when the heat radiating plate 113 is provided, the above-described creep phenomenon occurs, and the electrical connection between the fluorescent tube 114 and the connection electrode is made. However, there is a problem that a poor conduction failure still occurs.

Next, problems concerning workability and reliability will be described.

As described with reference to FIGS. 5 and 6, the backlight device 100B integrated with the liquid crystal display device 130 has the fluorescent tube assembly 11B connected to the mounting hole of the backlight mold 135 during maintenance. 134. However, conventionally, when the fluorescent tube assembly 11B is attached to and detached from the attachment hole 134, the open end face 125 of the reflector 115 is directly connected to the backlight mold 135 and / or the light guide plate 1.
12, and was configured to face. Therefore, when the fluorescent tube assembly 11B is attached and detached in the directions indicated by the arrows X1 and X2 in FIG. 5, the incident surface 121 of the light guide plate 112 and the backlight mold 135 are shaved by the opening end surface 125 of the reflector 115. There was a problem.

As described above, when the incident surface 121 and the backlight mold 135 are shaved by the opening end surface 125,
A great deal of force is required when attaching and detaching the fluorescent tube assembly 111B to and from the attachment hole 134, and workability is significantly reduced.
Further, when the incident surface 121 and the backlight mold 135 are further scraped, light from the fluorescent tube assembly 111B is not properly incident on the light guide plate 112, and the reliability of the backlight device 100B is reduced. Also,
At the time of mounting, the fluorescent tube assembly 111B and the mounting hole 1
34, which causes a problem that the reliability of the backlight device 100B is also reduced.

Next, problems concerning productivity will be described.

As described above, the end of the fluorescent tube 114 is
This is the site where the most heat is generated. However, conventionally, the electrode provided on the fluorescent tube 114 and the connection electrode connected to the wiring are configured to be soldered.
For this reason, due to a remarkable temperature rise at the end of the fluorescent tube 114, the solder is re-melted, and separation occurs between the electrode of the fluorescent tube 114 and the connection electrode, and the fluorescent tube 114 may not be able to emit light. There was a problem.

In order to avoid this, it is conceivable to use a solder having a high melting point (high melting point solder). It is necessary to perform soldering at a temperature, and there is a problem that productivity is reduced as compared with a configuration using a low melting point solder.

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 improve heat dissipation, workability, reliability, and productivity.

[0030]

Means for Solving the Problems In order to solve the above problems, the present invention is characterized by taking the following means.

According to the first aspect of the present invention, there is provided a light guide plate having an incident surface on which a light beam from a light source enters, an exit surface from which the incident light beam exits, a fluorescent tube serving as a light source, and an end portion of the fluorescent tube. Tube assembly comprising: a holding member for holding a light source; a light source reflecting mechanism for reflecting light from the fluorescent tube to guide the light from the opening to an incident surface of the light guide plate; and the fluorescent tube assembly and the light guide plate. Is mounted, and a radiator plate for radiating heat generated from the fluorescent tube is provided in the backlight device of the liquid crystal display device, wherein the radiator plate is located between the holding member and the light guide plate. And a heat introducing portion formed so that the heat introducing portion is thermally connected to the holding member.

According to the above invention, since the heat introducing portion is thermally connected to the holding member, the heat generated in the fluorescent tube serving as a heat source is transmitted to the heat radiating plate via the holding member and the heat introducing portion. The heat is dissipated in the heat sink. Therefore, the heat generated in the fluorescent tube can be efficiently radiated to the outside.

Further, the heat introducing portion is formed so as to be located between the holding member and the light guide plate. The position where the holding member is provided is a portion where the fluorescent tube is held, and light is not emitted to the light guide plate at this portion. Therefore, even if the heat introducing portion is provided between the holding member and the light guide plate, the light amount incident on the light guide plate does not decrease due to this.

Preferably, the holding member is made of a material having a thermal conductivity of at least 0.5 [W / (m · K)]. By using a material having a high thermal conductivity for the holding member, heat generated in the fluorescent tube can be more efficiently radiated to the outside.

According to a second aspect of the present invention, in the backlight device according to the first aspect, the heat introducing portion is configured to protrude toward the holding member from an incident surface of the light guide plate. It is assumed that.

According to the above invention, since the heat introducing portion protrudes toward the holding member from the light incident surface of the light guide plate, the heat introducing portion and the holding member come into contact with each other, and the heat introducing portion and the holding member come into contact with each other. Thermal connection can be reliably performed.

[0037] In the above structure, the heat introducing section may include:
A configuration may be adopted in which a connecting portion that is in contact with and thermally connected to the holding member and a tapered portion that is bent toward the light guide plate with respect to the connecting portion.

According to this structure, since the heat introducing portion is formed with the tapered portion bent toward the light guide plate with respect to the connecting portion,
When the fluorescent tube assembly is mounted on the heat sink, the tapered portion serves as a guide for mounting the fluorescent tube assembly. Therefore, when the fluorescent tube assembly is mounted on the heat sink, this mounting process can be easily performed.

In the above configuration, a cutout may be formed in a portion of the light guide plate located at the end of the fluorescent tube, and the heat introducing portion may be fitted into the cutout.

According to this configuration, since the notch formed in the light guide plate and the heat introducing portion formed in the heat sink are fitted, the light guide plate can be securely mounted on the heat sink with a simple structure. be able to.

According to a third aspect of the present invention, there is provided a light guide plate having an incident surface on which a light beam from a light source enters, an exit surface from which the incident light beam exits, a fluorescent tube serving as a light source, and a fluorescent tube. A liquid crystal display device comprising: a holding member that holds an end; and a fluorescent tube assembly including a light source reflecting mechanism that reflects light from the fluorescent tube to guide the light from the opening to an incident surface of the light guide plate. In the backlight device, a bent portion is formed on at least one of the end surfaces of the opening of the light source reflection mechanism, and the incident surface of the light guide plate and the end surface of the opening are separated from each other. is there.

According to the above invention, since the entrance surface of the light guide plate and the end surface of the opening are separated from each other, when the fluorescent tube assembly is mounted on the light guide plate, the entrance surface of the light guide plate and the opening of the light source reflection mechanism are provided. Sliding contact with the end face can be avoided. Therefore, when the fluorescent tube assembly is mounted on the light guide plate, generation of frictional force can be prevented, and mounting workability can be improved.

Further, by making the incident surface and the end face of the opening not in sliding contact with each other as described above, it is possible to prevent the incidence surface from being damaged (cut). If the entrance surface is damaged, light from the light source will not be satisfactorily incident on the light guide plate, and display quality using the backlight device will be degraded. However, as described above, it is possible to prevent the incidence surface from being damaged (scraped), thereby realizing high display quality.

Further, since the entrance surface and the end surface of the opening can be separated simply by forming a bent portion on at least one of the end surfaces of the opening of the light source reflection mechanism, the above-mentioned respective effects can be obtained by a simple process. Can be.

According to a fourth aspect of the present invention, in the backlight device according to the third aspect, the bent portions are provided at both ends of the light source reflecting mechanism and at positions not contributing to light emission of the light source. It is characterized by the following.

According to the above configuration, the bent portions are provided at both ends of the light source reflecting mechanism and at positions not contributing to light emission of the light source. Therefore, even if the bent portion is formed in the fluorescent tube assembly, the bent portion does not hinder the light emitted from the light source toward the light guide plate, and the luminous efficiency can be maintained high.

According to a fifth aspect of the present invention, in the backlight device according to any one of the first to seventh aspects, a linear light source having a rod-shaped electrode is used as the light source;
A clip-shaped contact member having a spring property for crimping and electrically connecting to the rod-shaped electrode is provided in the fluorescent tube assembly.

According to the present invention, when the linear light source is disposed in the fluorescent tube assembly, soldering is not required, and the rod-shaped electrode of the linear light source is simply mounted on a clip-shaped contact member having a spring property. Only by (inserting), the rod-shaped electrode and the contact member can be electrically connected. Therefore, it is possible to improve the assemblability and maintainability of the fluorescent tube assembly.

In the above configuration, a contact holding member for holding the contact member may be provided in the fluorescent tube assembly in addition to the holding member.
In the case of this configuration, since the holding member for holding the linear light source and the contact holding member for holding the contact member have different configurations, the shape of each holding member is used for holding the linear light source and holding the contact member. An optimal shape can be obtained. Therefore, the linear light source and the contact member can be reliably held.

Further, in the above configuration, one of the holding member and the contact holding member may be fitted to the light source reflecting mechanism. In the case of this configuration, the holding member or the contact holding member is mounted on the light source reflecting mechanism by the fitting force, so that it can be mounted with good assembling property.

[0051]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 7 to 11 are views for explaining a backlight device 10A according to a first embodiment of the present invention.

FIG. 7 is an enlarged sectional view showing the vicinity of the fluorescent tube assembly 11A of the backlight device 10A.
FIG. 9 is an exploded perspective view of the backlight device 10A, FIG. 9 is an external view of the backlight device 10A, FIG. 10 is a perspective view showing a state in which the fluorescent tube assembly 11A is mounted, and FIG. It is a figure which expands and shows the part shown.

As shown in each figure, the backlight device 10
A is a fluorescent tube assembly 11A, light guide plate 1
2, and a heat sink 13 and the like. The backlight device 10A functions as, for example, a backlight of a liquid crystal display device.

The fluorescent tube assembly 11A includes a fluorescent tube 14,
A reflector 15A (corresponding to a light source reflecting mechanism described in the claims) and a fluorescent tube holding member 16A (corresponding to a holding member described in the claims) are provided. In this embodiment, two fluorescent tubes 14 are provided, and each of the fluorescent tubes 14 is a cold cathode fluorescent tube. Electrodes (not shown) are provided at both ends of each fluorescent tube 14, and the vicinity of the position where the electrodes are formed is held by a fluorescent tube holding member 16A.

The fluorescent tube holding member 16A is made of normal silicon rubber or silicon rubber having high heat conductivity for heat radiation. The silicon rubber desirably has a thermal conductivity of at least 0.5 [W / (m · K)]. Other materials having this thermal conductivity can also be used.

Further, inside the fluorescent tube holding member 16A,
A connection electrode (both not shown) to which the wiring is connected is provided. In this embodiment, the electrodes of the fluorescent tube 14 are electrically connected by soldering to the connection electrodes.

The reflector 15A is made of a metal such as stainless steel, iron, or aluminum having a good thermal conductivity, and has a high light reflectance by forming a silver vapor deposition layer or a white reflection layer on the light source side. It is configured to be. The reflector 15A has a substantially cylindrical shape and has an opening 37 at a position facing the incident surface 21 of the light guide plate 12, which will be described later. The reflector 15A is provided along the fluorescent tube 14, and has a function of reflecting the light generated in the fluorescent tube 14 to guide the light from the opening 37 to the incident surface 21 of the light guide plate 12.

By providing the reflector 15A, light generated by the fluorescent tube 14 can be efficiently incident on the light guide plate 12. In addition, the reflector 15
Since the fluorescent tube holding members 16A are fixed to both ends, a function of holding the fluorescent tubes 14 via the fluorescent tube holding members 16A is also achieved.

The light guide plate 12 has a flat plate shape and is made of, for example, a light transmitting resin such as an acrylic resin. The light guide plate 112 has a side surface serving as an incident surface 21 on which the light from the fluorescent tube assembly 11A described above is incident, and an output surface 40 on the upper surface for emitting light to a liquid crystal display device or the like to be irradiated. It has been.

The light incident from the incident surface 21 is
The light travels while reflecting inside, and is emitted from the emission surface 40 to the outside under a predetermined reflection condition. Accordingly, light having substantially uniform light intensity is emitted from the emission surface 40 toward the liquid crystal display device or the like.

The radiator plate 13 is formed of a metal having high thermal conductivity. The heat radiating plate 13 functions as a housing in which the fluorescent tube assembly 11A and the light guide plate 12 are mounted, and also has two functions of radiating heat generated in the fluorescent tube 14.

As shown in FIG. 8, the heat radiating plate 13 is formed with the heat introducing portion 17 and the side wall portion 41. The heat introducing portions 17 are formed at four corner positions of the heat radiating plate 13, and are configured to be cut and raised perpendicularly to the bottom portion 42 of the heat radiating plate 13. The light guide plate 12 has a notch 18.
Are formed, and the formation position of the notch 18 is configured to correspond to the formation position of the heat introduction part 17.

Therefore, the light guide plate 12 is attached to the heat radiating plate 13 by fitting the heat introducing portion 17 into the notch 18. Therefore, the light guide plate 12 can be securely attached to the heat radiation plate 13 with a simple configuration.

When the light guide plate 12 is attached to the heat sink 13, a slide groove 19 is formed between the incident surface 21 of the light guide plate 12 and the side wall 41 of the heat sink 13. See FIG. 11). This slide groove 19
The fluorescent tube assembly 11A extends in the directions of arrows X1 and X2 in the figure, and is configured to be mounted in the slide groove 19.

At the time of this mounting, each fluorescent tube assembly 11A
Is mounted in the slide groove 19 by sliding in a direction indicated by an arrow X1 or a direction indicated by an arrow X2 in each drawing. FIGS. 10 and 11 show an example in which the fluorescent tube assembly 11A is slid in the direction of arrow X2. At this time, the fluorescent tube assembly 11A is configured to be attachable / detachable to / from the slide groove 19, so that the attached fluorescent tube assembly 11A can be pulled out from the slide groove 19, thereby improving maintenance. I have.

Further, as shown in an enlarged manner in FIG. 11, each heat introducing portion 17 has a configuration in which a tapered portion 20A and a connecting portion 20B are integrally formed. The tapered portion 20 formed with each heat introducing portion 17 is formed inside the connecting portion 20B, and has a tapered shape capable of guiding the movement of the fluorescent tube assembly 11A slidably mounted in the slide groove 19. . The connecting portion 20B is connected to the fluorescent tube assembly 11.
In a state where A is mounted at a predetermined position of the slide groove 19 (hereinafter, this state is referred to as a mounted state), the structure A is in contact with the fluorescent tube holding member 16A provided in the fluorescent tube assembly 11A and is thermally connected. Have been.

As described above, by forming the tapered portion 20A having the above-described configuration in the heat introducing portion 17, when the fluorescent tube assembly 11A is mounted in the slide groove 19 (heat radiating plate 13), the tapered portion 20A becomes the fluorescent tube. Since it serves as a guide for the assembly 11A, mounting work can be easily performed. Since each tapered portion 20A is formed inside the connecting portion 20B, the fluorescent tube assembly 11A can be slid in the direction of arrow X1 in the figure or slid in the direction of arrow X2. In this case, the fluorescent tube assembly 11A is reliably guided to the tapered portion 20A.

Here, paying attention to the position and function of the heat introducing portion 17 when the fluorescent tube assembly 11A is mounted at a predetermined mounting position in the slide groove 19 (mounting state).
This will be described below.

FIG. 7 is an enlarged view of the vicinity of the fluorescent tube holding member 16A of the fluorescent tube assembly 11A in the mounted state. In this mounting state, the connection section 2 of the heat introduction section 17
0B denotes the fluorescent tube holding member 16A and the light guide plate 12 (incident surface 2).
1) and the fluorescent tube holding member 16A
And is thermally connected.

At this time, the connecting portion 20B of the heat introducing portion 17 is
The light guide plate 12 is configured to protrude from the incident surface 21 toward the fluorescent tube holding member 16A. As described above, by projecting the connecting portion 20B toward the fluorescent tube holding member 16A, the connecting portion 20B comes into strong contact with the fluorescent tube holding member 16A, and thus the thermal connection between the fluorescent tube holding member 16A and the heat introducing portion 17 is achieved. Connection can be reliably performed.

As described above, since the heat introducing portion 17 is thermally connected to the fluorescent tube holding member 16A, the heat generated in the fluorescent tube 14 as a heat source causes the fluorescent tube holding member 16A and the heat introducing portion 17 to pass through. The heat is transmitted to the heat radiating plate 13 and is radiated by the heat radiating plate 13. Therefore, heat generated in the fluorescent tube 14 can be efficiently radiated to the outside.

As described above, the fluorescent tube holding member 1
6A is formed of a material having a high thermal conductivity (silicone rubber having a thermal conductivity of at least 0.5 [W / (m · K)]). Thus, the fluorescent tube holding member 16
By using a material having a high thermal conductivity as the material of A, the heat generated in the fluorescent tube 14 can be more efficiently radiated to the outside. The reflector 15A is a heat sink 1
3, and the heat of the fluorescent tube holding member 16A is also radiated to the heat radiating plate 13 via the reflector 15A at this position, as in the conventional case.

Here, the fluorescent tube 14 used in this embodiment is
Is a cold-cathode tube type fluorescent tube, which requires a lot of power (= cathode drop voltage x tube current) near the cathode to emit electrons, and this power is mostly converted to heat as reactive power. Would. Therefore, when a larger screen and higher brightness are desired in recent years, the cathode drop voltage and the tube current, which are the main components of the tube voltage, inevitably increase, and as a result, the arrangement position of the fluorescent tube holding member 16A Is raised as described above.

However, in this embodiment, the heat introducing portion 17 is brought into contact with the fluorescent tube holding member 16A where the temperature rises most, and the heat generated in this portion is actively radiated. Fluorescent tube 1 in 16A
The soldered portion between the electrode 4 and the connection electrode 4 can be prevented from peeling off, and the reliability of the backlight device 10A can be improved.

Further, the heat introducing section 17 is provided with the fluorescent tube holding member 1.
It is formed so as to be located between 6A and the light guide plate 12. The arrangement position of the fluorescent tube holding member 16A is
4 is a portion where light is not emitted toward the light guide plate 12. Therefore, the fluorescent tube holding member 16
Even if the heat introducing portion 17 is provided between the light guide plate 12 and the light guide plate 12, the amount of light incident on the light guide plate 12 does not decrease.

Next, a second embodiment of the present invention will be described. 12 to 14 show a backlight device 10B according to a second embodiment. The backlight device 10 </ b> B according to the present embodiment is configured to be integrated into the liquid crystal display device 30. 12 to 14, the same components as those described with reference to FIGS. 7 to 11 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 12, the liquid crystal display 30
Is configured to include a liquid crystal panel 33 and a backlight device 10B in a housing 31. Housing 3
Reference numeral 1 denotes a housing made of a metal such as stainless steel, iron, or aluminum, and a display opening 32 is formed in an upper portion thereof. The liquid crystal panel 33 is connected to the housing 31.
And is exposed to the outside from the display opening 32 formed in the substrate.

As shown in FIG. 13, the backlight device 10B is arranged below the liquid crystal panel 33. For this reason, a backlight mold 35 (shown in satin in FIG. 13) is provided in the housing 31, and the backlight device 10B is configured to be held by the backlight mold 35.

In this embodiment, the radiator plate 13 provided in the first embodiment is not provided. However, a radiator plate may be provided in the configuration of the present embodiment.

On the other hand, as shown in FIG. 12, the fluorescent tube assembly 11B
It is configured so that it can be attached and detached by inserting and removing in the Z and X2 directions, so that maintenance is improved as in the first embodiment. For this reason, the mounting hole 34 for mounting and dismounting the fluorescent tube assembly 11B is formed in the backlight mold 35.

Here, attention is paid to the reflector 15B of the fluorescent tube assembly 11B in the present embodiment. As shown in FIG. 12, the fluorescent tube assembly 11B includes a non-light-emitting region B1 where the fluorescent tube holding member 16A is provided and does not perform light irradiation, and the fluorescent tube 14 is opened to the opening 37 to perform light irradiation. The light emitting region B2 is provided.

FIGS. 13 and 14A show the non-light emitting region B1.
FIG. 1 is a sectional view of a fluorescent tube assembly 11B in FIG.
4 (B) shows the fluorescent tube assembly 11 in the light emitting area B2.
It is sectional drawing of B.

As shown in FIGS. 13 and 14 (A), the reflector 15B constituting the fluorescent tube assembly 11B in the non-light emitting area B1 is bent at a substantially right angle in a state where the end is viewed in cross section, thereby bending the reflector 15B. The configuration is such that a portion 22 is formed. With this configuration, the opening end surface 25A of the reflector 15B is separated from the incident surface 21 of the light guide plate 12 (that is, the opening end surface 25A does not face the incident surface 21).

Thus, with this configuration, when the fluorescent tube assembly 11B is mounted on the light guide plate 12, the incident surface 21 and the backlight mold 35 of the light guide plate 12 and the opening end surface 25A of the reflector 15B are in sliding contact. Can be avoided. Since the opening end face 25A has a corner,
When the opening end face 25A is in direct sliding contact with the light guide plate 12 and the backlight mold 35 from the resin, the fluorescent tube assembly 11
As described above, the incident surface 21 and the backlight mold 35 are shaved by the movement of the opening end face 25A accompanying the mounting and dismounting of B.

However, the bent portion 22 is formed at the end of the reflector 15B, and the open end face 25A is
With the configuration separated from the second incident surface 21 and the backlight mold 35, the side surface of the bent portion 22 comes into contact with the incident surface 21 and the backlight mold 35. Since the side surface of the reflector 15B is a relatively smooth and smooth surface, when the fluorescent tube assembly 11B is attached to and detached from the attachment hole 34, excessive friction occurs between the incident surface 21 and the backlight mold 35 and the reflector 15B. The generation of force can be prevented. Thereby, when attaching and detaching the fluorescent tube assembly 11B to and from the liquid crystal panel 33, the workability of the attaching and detaching work can be improved.

Further, since the entrance surface 21 and the backlight mold 35 are not in sliding contact with the opening end surface 25A as described above, the entrance surface 21 and the backlight mold 35 may be damaged (cut). Can be prevented.
When the entrance surface 21 is damaged, light from the fluorescent tube 14 does not enter the light guide plate 12 properly. Also, the incident surface 21
When dust generated by the shaving of the backlight mold 35 adheres to the incident surface 21, the fluorescent tube 1
4 does not enter the light guide plate 12 satisfactorily.

In these cases, the backlight device 10
The display quality of the liquid crystal display device 30 using B deteriorates. However, by adopting the configuration of the present embodiment,
It is possible to prevent the incidence surface 21 from being scratched (scraped) and to prevent dust from adhering, and thus to achieve high display quality.

In this embodiment, the bent portion 22 is provided only in the non-display portion B1, in other words, at both ends of the reflector 15A and at positions not contributing to the light emission of the fluorescent tube 14. Therefore, even if the bent portion 25A is formed in the fluorescent tube assembly 11B, the bent portion 25A does not obstruct the light emitted from the fluorescent tube 14 toward the light guide plate 12, and the luminous efficiency can be maintained high. .

On the other hand, in the light-emitting area B1, FIG.
As shown in (B), it is not necessary for the reflector 15B to hold the fluorescent tube holding member 16A, and the opening end face 25B can be separated from the incident surface 21 (in the same drawing, the distance indicated by the arrow h in the drawing is shown). are doing). In the light emitting region B1, the backlight mold 35 is configured to be in sliding contact with the side surface (smooth surface) of the reflector 15B.

Therefore, in the light emitting area B1, the structure can be employed in which the entrance surface 21 and the backlight mold 35 do not easily come into sliding contact with the opening end surface 25A. Therefore, also in the light emitting area B1, it is possible to prevent the incidence surface 21 and the backlight mold 35 from being damaged (cut), and to improve the display quality of the liquid crystal display device 30.

Further, in this embodiment, the reflector 1
Only by forming the bent portion 25A on the end face of the opening 5B, the incident face 21 and the backlight mold 35 and the opening end face 2 are formed.
5A can be separated, so that the above-described various effects can be realized with a simple process.

In this embodiment, the bent portion 22
Are formed at both ends of the reflector 15B, but the bent portions 22 are not necessarily provided at both ends of the reflector 15B. If any one of them is provided, only one of them may be provided.

Next, a third embodiment of the present invention will be described. FIG. 15 is a sectional view of a main part of a fluorescent tube assembly 11C provided in the backlight device according to the third embodiment. The backlight device according to the present embodiment is characterized by the fluorescent tube assembly 11C, and the other configurations can apply the backlight devices 10A and 10B according to the first and second embodiments as they are. Only the configuration of the fluorescent tube assembly 11C will be described.

The fluorescent tube assembly 11C includes the fluorescent tube 14
(Linear light source), reflector 15C, fluorescent tube holding member 1
6B, a contact pin holding member 28, a contact pin 27, and the like. The fluorescent tube 14 is a cold cathode tube, and has a configuration in which bar electrodes 26 are provided at both ends. As described above, the fluorescent tube 14 composed of a cold cathode tube can cope with high brightness and large current,
As described above, the heat generation at the end of the fluorescent tube (that is, the rod-shaped electrode 26) increases.

The reflector 15C has the same structure as the reflectors 15A and 15B of the above-described embodiments, is made of a metal having good thermal conductivity, such as stainless steel, iron, or aluminum. By forming a silver deposition layer or a white reflective layer on the opposing inner wall, the light reflectance is increased. Holes 29 for holding a contact pin holding member 28 to be described later are formed at positions near both ends of the reflector 15C.

The fluorescent tube holding member 16B is provided with the reflector 1
5C, and has a function of holding both ends of the fluorescent tube 14. This fluorescent tube holding member 16B
Is made of, for example, silicone rubber, and is configured to be fitted and mounted on the contact pin holding member 28.

The contact pin holding member 28 holds the contact pin 27 and is formed of a resin having excellent withstand voltage characteristics. A claw portion 28a is formed at an outer peripheral position of the contact pin holding member 28, and the claw portion 28a fits into the hole 29 described above.
The contact pin holding member 28 is configured to be held by the reflector 15C.

Further, since the contact pin holding member 28 is held by the reflector 15C, the fluorescent tube holding member 16B is also held by the reflector 15C via the contact pin holding member 28. As described above, the fluorescent tube holding member 16B and the contact pin holding member 28 are
a is fitted to the hole 29 by the fitting force of the reflector 15C.
Because it is mounted on the, it can be mounted with good assemblability.

In the present embodiment, the fluorescent tube holding member 16B for holding the fluorescent tube 14 and the contact pin holding member 28 for holding the contact pin 27 are separate members.
Therefore, the shape of each of the holding members 16B and 28 is
Further, it is possible to make the shape optimal for holding the contact pin 27, and it is possible to reliably hold the fluorescent tube 14 and the contact pin 27.

Since the materials of the holding members 16B and 28 can be made different, the contact pin holding members 2
8 can be made a heat-resistant material. As described above, since the rod-shaped electrode 26 generates a larger amount of heat than the light-emitting portion of the fluorescent tube 14, excessive heat is also applied to the contact pin 27. However, the contact pin holding member 2
By forming 8 from a heat-resistant material, deformation or the like can be prevented from occurring even when excessive heat is applied. In addition, since heat-resistant materials are generally expensive, costs can be reduced as compared with a configuration in which all the holding members 16B and 28 including the fluorescent tube holding member 16B are formed of heat-resistant materials.

Next, the contact pin 27 will be described. The contact pin 27 is a contact pin holding member 2
8 are arranged inside. This contact pin 27
Is formed with a clip-shaped contact portion 27a having a spring property at one end thereof, and a connection portion 27b to which a wiring 24 connected to a power supply circuit (not shown) is crimp-connected at the other end portion. Are formed.

With this configuration, the fluorescent tube 14 and the wiring 24 are electrically connected by fitting the rod-shaped electrode 26 of the fluorescent tube 14 into the contact pin 27. That is, in the configuration of the present embodiment, when disposing the fluorescent tube 14 in the fluorescent tube assembly 11C, soldering is not required, and the rod-shaped electrode 26 is simply attached to the clip-shaped contact portion 27a having a spring property ( Only by inserting) the rod-shaped electrode 26 and the contact pin 27 can be electrically connected. Therefore, it is possible to improve the assemblability and maintainability of the fluorescent tube assembly 11C.

Further, even if the temperature of the rod-shaped electrode 26 is excessively increased due to an increase in luminance and an increase in current, the contact pin 2
Since the electrode 7 and the bar-shaped electrode 26 are not soldered, no solder peeling occurs between the electrodes 26 and 27, and the reliability of the fluorescent tube assembly 11C can be improved.

In the above-described embodiment, a configuration in which one fluorescent tube 14 is provided in the fluorescent tube assembly 11C has been described as an example. However, the number of fluorescent tubes 14 provided is not limited to this. Instead, the third embodiment described above can be applied to a configuration in which a plurality of components are provided.

In the present embodiment, the rod-shaped electrode 26 is inserted and mounted on the contact pin 27 from the longitudinal direction of the fluorescent tube 14. However, the rod-shaped electrode 26 is connected to the contact pin 27 from the longitudinal direction of the fluorescent tube 14. You may comprise so that attachment is possible.

With respect to the above description, the following items are further disclosed. (Supplementary Note 1) A light guide plate having an incident surface on which a light beam from a light source is incident, an emission surface from which the incident light beam is emitted, a fluorescent tube serving as a light source, and a holding member for holding an end of the fluorescent tube;
A fluorescent tube assembly provided with a light source reflecting mechanism for guiding light from the fluorescent tube to an incident surface of the light guide plate from an opening by reflecting the light from the fluorescent tube, and the fluorescent tube assembly and the light guide plate are mounted, and In a backlight device for a liquid crystal display device, comprising: a heat radiating plate for radiating heat generated from the fluorescent tube; a heat introducing unit provided on the heat radiating plate so as to be located between the fluorescent tube holding member and the light guide plate. To form
A backlight device for a liquid crystal display device, wherein the heat introduction unit is configured to be thermally connected to the fluorescent tube holding member. (Supplementary Note 2) In the backlight device according to Supplementary Note 1,
The fluorescent tube holding member has a thermal conductivity of at least 0.5 [W].
/ (M · K)], wherein the backlight device is made of a material having a thermal conductivity of: (Supplementary Note 3) The backlight device according to Supplementary Note 1 or 2, wherein the heat introduction unit is configured to protrude toward the fluorescent tube side from an incident surface of the light guide plate. (Supplementary Note 4) In the backlight device according to any one of Supplementary Notes 1 to 3, a notch portion is formed in a portion of the light guide plate located at an end of the fluorescent tube, and the heat introducing portion is formed in the notch portion. A backlight device characterized by being fitted. (Supplementary Note 5) A light guide plate having an incident surface on which a light beam from a light source enters, an exit surface from which the incident light beam exits, a fluorescent tube serving as a light source, and a holding member for holding an end of the fluorescent tube;
A fluorescent tube assembly comprising: a light source reflecting mechanism for reflecting light from the fluorescent tube to guide the light from the opening to the light incident surface of the light guide plate; A backlight device, wherein a bent portion is formed on at least one of the end faces of the opening of the mechanism, and the incident surface of the light guide plate is separated from the end face of the opening. (Supplementary Note 6) In the backlight device according to Supplementary Note 5,
A backlight device, wherein the bent portions are provided at both ends of the light source reflection mechanism and at positions not contributing to light emission of the light source. (Supplementary Note 7) In the backlight device according to any one of Supplementary Notes 1 to 6, a linear light source having a rod-shaped electrode is used as the light source, and the light source is pressed into the fluorescent tube assembly and electrically connected to the rod-shaped electrode. A backlight device comprising a clip-shaped contact member having a spring property for connection. (Supplementary Note 8) In the backlight device according to supplementary note 7,
A backlight device, wherein a contact holding member for holding the contact member is provided in the fluorescent tube assembly in addition to the holding member.

[0108]

According to the present invention as described above, the following various effects can be realized.

According to the first aspect of the present invention, heat generated in the fluorescent tube serving as a heat source is transmitted to the heat radiating plate via the holding member and the heat introducing portion and is radiated by the heat radiating plate. The generated heat can be efficiently radiated to the outside.

Further, since the heat introducing portion is formed so as to be located between the holding member and the light guide plate, even if the heat introducing portion is provided between the holding member and the light guide plate, it is incident on the light guide plate. Light quantity can be kept high.

The holding member is desirably formed of a material having a thermal conductivity of at least 0.5 [W / (m · K)]. By using a material having a high thermal conductivity for the holding member, heat generated in the fluorescent tube can be more efficiently radiated to the outside.

According to the second aspect of the present invention, since the heat introducing portion protrudes toward the holding member from the incident surface of the light guide plate, a thermal connection between the heat introducing portion and the holding member is provided. Can be performed reliably.

[0113] In the above structure, the heat introducing section may be provided with:
A configuration may be adopted in which a connecting portion that is in contact with and thermally connected to the holding member and a tapered portion that is bent toward the light guide plate with respect to the connecting portion.

According to this configuration, when the fluorescent tube assembly is mounted on the radiator plate, the tapered portion serves as a guide for mounting the fluorescent tube assembly, so that the mountability of the fluorescent tube assembly on the radiator plate can be improved. .

In the above configuration, a cutout may be formed at a position of the light guide plate located at the end of the fluorescent tube, and the heat introducing portion may be fitted into the cutout.

According to this configuration, since the notch formed in the light guide plate and the heat introducing portion formed in the heat radiator plate are fitted, the light guide plate can be securely attached to the heat radiator plate with a simple configuration. be able to.

According to the third aspect of the present invention, when the fluorescent tube assembly is mounted on the light guide plate, it is possible to avoid the sliding surface between the incident surface of the light guide plate and the end surface of the opening of the light source reflecting mechanism. It is possible to prevent a frictional force from being generated between the incident surface and the end face of the opening at the time of mounting, and it is possible to improve the mounting workability.

Further, since the entrance surface and the end surface of the opening are not in sliding contact with each other as described above, it is possible to prevent the entrance surface from being scratched (cut), thereby realizing high display quality. it can.

Furthermore, since the entrance surface and the end surface of the opening can be separated by simply forming a bent portion on at least one of the end surfaces of the opening of the light source reflecting mechanism, the above-described respective effects can be obtained by a simple process. Can be.

According to the fourth aspect of the present invention, even if a bent portion is formed in the fluorescent tube assembly, the bent portion does not hinder light emitted from the light source toward the light guide plate, and the light is emitted. Efficiency can be kept high.

According to the fifth aspect of the present invention, when the linear light source is disposed in the fluorescent tube assembly, no soldering is required, so that the assemblability and maintainability of the fluorescent tube assembly are improved. be able to.

In the above configuration, a contact holding member for holding the contact member may be provided in the fluorescent tube assembly in addition to the holding member.

In this configuration, since the holding member for holding the linear light source and the contact holding member for holding the contact member are different, the shape of each holding member is changed to the holding of the linear light source and the contact member. The linear light source and the contact member can be reliably held.

Further, in the above configuration, one of the holding member and the contact holding member may be fitted to the light source reflecting mechanism.

In this configuration, since the holding member or the contact holding member is mounted on the light source reflecting mechanism by the fitting force, it can be mounted with good assembling property.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing the vicinity of a fluorescent tube assembly of a backlight device according to a first conventional example.

FIG. 2 is an exploded perspective view of a backlight device as a first conventional example.

FIG. 3 is a perspective view of a backlight device as a first conventional example.

FIG. 4 is an exploded perspective view of a fluorescent tube assembly provided in a backlight device according to a first conventional example.

FIG. 5 is a perspective view of a backlight device as a second conventional example.

FIG. 6 is an enlarged sectional view showing the vicinity of a fluorescent tube assembly of a backlight device as a second conventional example.

FIG. 7 is an enlarged sectional view showing a main part of the backlight device according to the first embodiment of the present invention.

FIG. 8 is an exploded perspective view of the backlight device according to the first embodiment of the present invention.

FIG. 9 is a perspective view of the backlight device according to the first embodiment of the present invention.

FIG. 10 is a view showing a state in which the fluorescent tube assembly is pulled out in the backlight device according to the first embodiment of the present invention.

FIG. 11 is an enlarged perspective view of a main part of the backlight device according to the first embodiment of the present invention.

FIG. 12 is a perspective view of a backlight device according to a second embodiment of the present invention.

FIG. 13 is an enlarged sectional view showing a main part of a backlight device according to a second embodiment of the present invention.

FIG. 14 is a sectional view of a non-light emitting area and a light emitting area of a backlight device according to a second embodiment of the present invention.

FIG. 15 is an enlarged view showing a fluorescent tube assembly of a backlight device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10A-10C Back light apparatus 11A-10C Fluorescent tube assembly 12 Light guide plate 13 Heat sink 14 Fluorescent tube 15A-15C Reflector 16A, 16B Fluorescent tube holding member 17 Heat introduction part 18 Notch 19 Slide groove 20 Taper part 21 Light entrance end face 22 Folded part 26 Bar-shaped electrode 27 Contact pin 28 Contact pin holding member 29 Engagement hole 30 Liquid crystal display 31 Housing 32 Opening 33 Liquid crystal panel 34 Mounting hole 35 Backlight mold

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiji Nito 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa F-term in Fujitsu Limited (reference) 2H091 FA14Z FA23Z FA41Z FA42Z FB02 FB08 LA04 LA12 LA16

Claims (5)

[Claims] 1. A light guide plate having an incident surface on which a light beam from a light source enters, an exit surface from which the incident light beam exits, a fluorescent tube serving as a light source, and a holding member for holding an end of the fluorescent tube. A fluorescent tube assembly provided with a light source reflecting mechanism for guiding light from the fluorescent tube to the entrance surface of the light guide plate from the opening by reflecting the light from the fluorescent tube; and mounting the fluorescent tube assembly and the light guide plate, A radiator plate for radiating heat generated by the fluorescent tube;
In the backlight device for a liquid crystal display device, comprising: a heat introducing portion formed on the heat radiating plate so as to be located between the holding member and the light guide plate; and the heat introducing portion forms heat with the holding member. A backlight device for a liquid crystal display device, wherein the backlight device is configured to be connected to each other. 2. The backlight device according to claim 1, wherein the heat introducing portion is configured to protrude toward the holding member from an incident surface of the light guide plate. 3. A light guide plate having an incident surface on which a light beam from a light source is incident, an emission surface from which the incident light beam is emitted, a fluorescent tube serving as a light source, and a holding member for holding an end of the fluorescent tube. And a light source reflecting mechanism for reflecting light from the fluorescent tube to guide the light from the opening to the incident surface of the light guide plate. A backlight device, wherein a bent portion is formed on at least one of the end surfaces of the opening of the reflection mechanism, and the incident surface of the light guide plate is separated from the end surface of the opening. 4. The backlight device according to claim 3, wherein the bent portions are provided at both ends of the light source reflection mechanism and at positions that do not contribute to light emission of the light source. 5. The backlight device according to claim 1, wherein a linear light source having a rod-shaped electrode is used as the light source, and the light source is crimped to the rod-shaped electrode in the fluorescent tube assembly. A backlight device comprising a clip-shaped contact member having a spring property to be electrically connected.