JPH10207406A - Backlight device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a backlight device, to reduce costs and to improve the display quality of a liquid display provided in the backlight device. SOLUTION: A backlight device is composed of a light transmission plate, a cold cathode fluorescent tube (CCFT) 2 and a metallic lamp reflector 10. The lamp reflector 10 has a condensing part 10b for condensing lights emitted from the CCFT 2 in the light transmission plate and a plate part 10a for covering the backside of the light transmission plate. Supporting parts 10c and 10c for supporting the CCFY 2 are provided in the lamp reflector 10. By these supporting parts 10c and 10c, the lamp reflector 10 and the CCFT 2 are held in specified positions. Further, the lamp reflector 10 comes into contact with the CCFT 2, receives heat transmitted from the CCFT 2 and thereby generates heat. A conductive layer is formed in the outer surface of the condenser part 10b and, without taking any space, the electrode of one end part 2a of the CCFT 2 is connected to the inverter 4 of the other end side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device for illuminating a display device such as a liquid crystal display from the back.

[0002]

2. Description of the Related Art Generally, in various liquid crystal displays, a backlight device (backlight unit) is arranged on the back surface of a liquid crystal panel so that the liquid crystal panel is illuminated from the back surface. As one of the backlight devices, there is known an edge light type in which a cold cathode fluorescent tube (hereinafter abbreviated as CCFT) is arranged close to an end face of a light guide plate. Conventionally, the backlight device of the edge light type is
For example, it had the following structure.

That is, as shown in FIGS. 4 and 5, a backlight device is a light guide plate 1 for guiding light to a liquid crystal panel side.
A CCFT 2 disposed close to at least one of the left and right or upper and lower end surfaces of the light guide plate 1, a lamp reflector (reflector) 3 for condensing light emitted from the CCFT 2 on the end surface of the light guide plate 1, It has an inverter 4 (shown in FIG. 4) for driving the CCFT 2, and a wiring cable 5 and a wiring cable 6 (shown in FIG. 4) for connecting the inverter 4 to the electrodes of the CCFT 2.

The light guide plate 1 is, for example, a transparent acrylic plate having a dot-shaped print pattern printed on the back surface. Light incident from an end face of the light guide plate 1 is a refractive index of light between acrylic and air. Due to this difference, the light is repeatedly reflected in the light guide plate 1 and the reflectance changes in the portion of the light guide plate where the ink is printed, so that light is emitted from the surface of the light guide plate. By changing the printing density depending on the position on the back surface of the light guide plate 1, the amount of light emitted from each position on the front surface of the light guide plate 1 is made as uniform as possible.

[0005] The CCFT2 is a kind of fluorescent tube,
The fluorescent tube includes a hot cathode fluorescent tube, a semi-hot electrode fluorescent tube, and the like in addition to the CCFT2. However, the CCFT2 is usually used for a backlight device because of problems such as heat generation and life. The lamp reflector 3 surrounds the periphery of the CCFT 2 in a state where the portion facing the end face of the light guide plate 1 is opened,
The light emitted from the FT 2 is focused on the end face side of the light guide plate 1. Further, the inverter 4 has a CCF
This is for driving T2 and supplying power to CCFT2.

In the backlight device, for example, each component such as the light guide plate 1, the CCFT 2, the lamp reflector 3, the inverter 4, and the wiring cables 5, 6 is used.
As shown in FIG. 4, the components are housed in a case 7 on the rear side of the liquid crystal display, and the components are positioned in the state shown in FIG. 5 by a fixed support portion and other fixed support members provided in the case 7. The position of the CCFT 2, the lamp reflector 3, and the light guide plate 1 is shifted so that the luminance of the back lamp device does not decrease and the luminance does not become uneven.

[0007]

By the way, CCFT2
However, although it is low in comparison with the hot cathode fluorescent tube, it generates heat at the time of lighting, and since the CCFT 2 is surrounded by the lamp reflector 3, there is no place for heat to escape, and heat is generated in the CCFT 2 part. There was a possibility of becoming muffled. When the backlight device using the CCFT2 is used for a liquid crystal display, if the heat is trapped in the CCFT2 as described above, the temperature distribution of the liquid crystal display becomes uneven, and the liquid crystal has a temperature characteristic. Therefore, there is a possibility that the unevenness of the temperature distribution affects the display quality of the liquid crystal display.

[0008] The distribution cable 5 for CCFT2 is
This is for connecting the electrode at one end of the CCFT 2 to the inverter 4 at the other end of the CCFT 2,
The distribution cable 5 needs to be arranged outside the lamp reflector 3 so as not to interfere with the light collection of the lamp reflector 3. For example, as shown in the above-described conventional example, the side edge of the backlight device is required. Will be placed in In this case, a space for the distribution cable is provided at the side edge of the backlight device, and the width of the backlight device is increased. On the other hand, in a liquid crystal display, in order to reduce the size of the liquid crystal display without changing the size of the display screen, the frame outside the display screen of the liquid crystal display, the so-called frame, is narrowed so as to reduce the width of the frame. However, the wiring cable is arranged at a side edge portion of the backlight device, that is, at a portion corresponding to a frame of the liquid crystal display of the backlight device, and the width of this portion is increased, so that a narrow frame of the liquid crystal display is formed. Had been hindered.

In the above-mentioned backlight device,
As described above, it is necessary to maintain the positional relationship between the components such as the reflector 3, the CCFT 2, and the light guide plate 1 in a predetermined state in order to suppress variations in luminance. It is necessary to provide a portion or to use a fixed support member for positioning and fixing each component of the backlight device. As a result, the processing shape of the case 7 becomes complicated, the number of parts increases, and the assembling work becomes complicated, thereby increasing the manufacturing cost of the backlight device. Further, when the components of the backlight device are fixed and supported as described above, it is necessary to provide a space for the fixed support portion and the fixed support member in the case of the backlight device, which reduces the size of the backlight device. Was hindered.

An object of the present invention is to reduce the size and cost of a backlight device and to improve the display quality of a liquid crystal display when the backlight device is used for a liquid crystal display.

[0011]

According to a first aspect of the present invention, there is provided a backlight device for illuminating a display screen of a display device from a back surface side, comprising: a light source having a tubular body; A light guide plate that guides the light to the display screen side, and a reflector that substantially surrounds the periphery of the light source except for a portion facing the light guide plate, and reflects light projected from the light source and condenses the light on the light guide plate. Wherein the reflector is made of metal and supports the light source.

According to the above configuration, when the light source generates heat, the metal reflector having a high thermal conductivity supports the light source, so that the heat of the light source is transmitted to the reflector and the reflector is The heat conducted to the backlight plate is efficiently radiated from the reflection plate, and heat is stored in the light source portion of the backlight device, so that the temperature distribution is reduced in the backlight device and the liquid crystal display including the backlight device. The occurrence of unevenness can be prevented. Therefore, it is possible to prevent the above-mentioned unevenness of the temperature distribution from affecting the display quality of the liquid crystal display as the display device, and to improve the display quality.

Further, since the light source is supported by the reflection plate, the members for supporting the light source can be simplified. Therefore, the processing shape of the case can be simplified and the number of parts can be reduced, so that the manufacturing cost of the backlight device and a display device such as a liquid crystal display having the backlight device can be reduced. At the same time, the efficiency of the manufacturing operation can be improved.

According to a second aspect of the present invention, in the backlight device, it is preferable that supporting portions for supporting both ends of the light source and determining a positional relationship between the reflecting plate and the light source are provided on the reflecting plate. Features. According to the above configuration, the positional relationship between the reflector and the light source is determined by the support of the reflector, so that in addition to the reflector and the light source, the fixed support member that determines the position between the reflector and the light source, and the case is fixed. A support portion is not required. For example, the light source is supported by the support portion of the reflector and the reflector and the support portion can be housed in the case in an integrated state. And the number of parts can be reduced.

Therefore, the manufacturing cost of the backlight device and the liquid crystal display having the backlight device can be further reduced, and the efficiency of the manufacturing operation can be further improved. Further, it is possible to omit a space in which the above-described fixed support portion and the fixed support member are arranged, and it is possible to reduce the size of the backlight device and the liquid crystal display having the backlight device.

According to a third aspect of the present invention, in the backlight device, the reflection plate has a cylindrical condensing portion that surrounds the light source and has an opening at a portion facing the light guide plate. And, the support portion is formed in a shape narrowed so as to sandwich both ends of the light source at both end portions of the light condensing portion, and the light source is held on a reflector by the support portion, and the reflector plate Are in contact with the light source at the support portion.

According to the above configuration, since the light source is in contact with the supporting portion, the backlight device and the display device such as a liquid crystal display having the backlight device have The display quality can be improved by preventing the occurrence of unevenness in the temperature distribution, and the light source is supported by the support portion of the reflection plate, so that the reflection plate and the light source can be separated from each other. Since they can be integrated into a unit, it is possible to reduce manufacturing costs, improve work efficiency in manufacturing, and reduce the size.
In addition, both ends of the condensing part of the reflector are formed as supporting parts which are narrowed down so as to sandwich the light source. The supporting part supports the light source and comes into contact with the light source, so that the configuration is extremely simple. Thus, the above-described effects can be achieved.

In the backlight device according to a fourth aspect of the present invention, the reflection plate is provided with a plate portion integrally connected to the light-collecting portion and extending to a rear surface side of the light guide plate. It is characterized by. According to the above configuration, since the reflecting plate is provided with the plate portion extending on the back surface side of the light guide plate, the area of the reflecting plate can be increased, and the efficiency of the above-described heat radiation by the reflecting plate can be improved.

Further, if the plate portion is provided over substantially the entire back surface of the reflector, when the heat generated from the light source is conducted by the reflector, the heat is conducted to almost the entire surface of the backlight device. Therefore, the unevenness of the temperature distribution in the backlight device can be further reduced. Also, if the plate portion of the reflector is configured to cover the entire back surface of the light guide plate, and if the light guide plate can be fixed to the reflector, the reflector may be used as a backlight device or the backlight device. In this case, the plate portion of the reflector is exposed on the back surface of the liquid crystal display, and the efficiency of heat dissipation by the reflector is further improved. be able to.

According to a fifth aspect of the present invention, in the backlight device, the reflector is provided so as to extend from one end of the light source to the other end, and at one end of the light source, An electrode at one end of the light source is connected to the reflector, and the reflector serves as a conductor for connecting the electrode at one end of the light source to a power source at the other end of the light source. It is characterized by being.

According to the above arrangement, for example, a wiring cable is connected to the electrode at one end of the light source, and the wiring cable is pulled to the other end of the light source. When the electrodes at both ends of the light source are connected to a power source, it is not necessary to arrange a wiring cable from one end of the light source to the other end side. Power can be supplied to the electrode at the end of. Therefore, the space for the wiring cable arranged from one end to the other end of the light source can be omitted, so that the size of the backlight device can be reduced, and the backlight device has the backlight device. The size of a display device such as a liquid crystal display can be reduced. In particular, the width of the frame portion of the liquid crystal display can be reduced, and the frame of the liquid crystal display can be narrowed.

According to a sixth aspect of the present invention, in the backlight device, a thin conductive layer formed by laminating a conductor layer between two insulating layers extends from one end to the other end of the light source. Provided on the outer surface of the reflection plate as described above, at one end of the light source, an electrode at one end of the light source is connected to the conductive layer, and at the other end of the light source, The conductive layer is connected to a power supply.

According to the above configuration, by using the conductive layer, power can be supplied to the electrode at one end of the light source from the other end side of the light source, and the conductive layer has a thin film shape. Since almost no space is required for disposing the conductive layer, the backlight device can be reduced in size, and the display device such as a liquid crystal display having the backlight device can be made narrower. It is possible to make a picture frame.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a backlight device as an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a side edge of the backlight device of this example in a state where a light guide plate 1 (shown by a broken line in FIG. 2) is removed, and FIG. 2 is a cross-sectional view taken along the line BB of FIG. FIG. 3 shows in detail the portion denoted by reference numeral C in FIG.
In the description of the backlight device of this example,
Components that are substantially the same as those of the conventional backlight device are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIGS. 1 to 3, the backlight device of this example includes a light guide plate 1 (shown in FIG. 2), a CCFT 2 which is a kind of a fluorescent tube serving as a light source, and an inverter 4 for driving the CCFT 2. (Shown in FIG. 1), a lamp reflector 10 serving as a reflector, a conductive layer 11 provided on the lamp reflector 10, and a common lead (wiring) for connecting the electrode at one end 2a of the CCFT 2 to the conductive layer 11. ) 12
(Shown in FIGS. 1 and 3), the conduction layer 11 and the inverter 4
A common line 4a connecting the common side of the inverter 4; an HV line 4b connecting the electrode of the other end 2b of the CCFT 2 to the high voltage (hereinafter abbreviated as HV) side of the inverter 4;
And a cap 13 that covers the two ends 2a and 2b of the CFT 2, respectively.

The lamp reflector 10 is made of, for example, aluminum, iron, stainless steel, copper, other metals or alloys of various metals, and has a rigidity capable of maintaining its shape. In addition, the lamp reflector 10 has elasticity as a metal, and has high thermal conductivity, high conductivity, and high light reflectance as a metal. The lamp reflector 10 is
A plate portion 10a (partially shown in FIGS. 1 and 2) disposed along the light guide plate 1 so as to cover the back surface of the light guide plate 1, and at least one of the left and right or upper and lower side edges of the light guide plate 1 The light collector 10b is folded in a state in which the side edge of the lamp reflector 10 corresponding to the above is bent in a U-shaped cross section as shown in FIG.
And the conductive layer 11 formed on the outer surface of the light collector 10b.
And

The plate portion 10a has a slightly larger area than the light guide plate 1 and has a function of a case for covering the back surface of the light guide plate 1. The light guide plate 1a is attached to the plate portion 10a by an attachment means (not shown). Is preferably fixed. The mounting means may be any as long as it can fix the light guide plate 1 to the lamp reflector 10. For example, the plate portion 10a may be provided with a U-shaped section fitted to the side edge of the light guide plate 1. . Also, the plate portion 10a of the lamp reflector 10
When the light guide plate 1 is fixedly supported by the light source, and the CCFT 2 is fixedly supported by the condenser part 10b of the lamp reflector 10 as described later, the plate portion 10a is, for example, a back plate of a liquid crystal display case. May also be used.

Further, when the backlight device is set on the liquid crystal display, the lamp reflector 10 and the light guide plate 1 are positioned and fixed to the case of the liquid crystal display or a fixed support member attached to the case. In this case, the light guide plate 1 may not be fixed to the lamp reflector 10. In this case,
It is not necessary for the plate portion 10a of the lamp reflector 10 to cover the entire back surface of the light guide plate 1, but it is preferable that the area of the plate portion 10a be large in order to enhance the heat radiation performance as described later. Further, the plate portion 10a of the lamp reflector 10 and the light guide plate 1 may be bonded, or the plate portion 10a and the light guide plate 1 may be bonded.
And a reflection plate may be disposed between the
The surface 0a on the light guide plate 1 side may also serve as a reflection plate.

The condensing unit 10b is, for example, a CCFT2
Is disposed at one of the left and right side edges or one of the upper and lower side edges of the backlight device, and one side edge of the left and right side edges or the upper and lower side edges of the plate portion 10a is provided. Placed in the department. Further, when the CCFT 2 is disposed on each of the left and right side edges of the backlight device, or when the CCFT 2 is disposed on each of the upper and lower side edges, the condensing portion 10b is provided on the left and right side edges of the plate portion 10a. It is arranged on both or both upper and lower edges. In this example, the CCFT 2 will be described as being disposed on the right edge of the backlight device, and the condensing unit 10b will be described as being disposed on the right edge of the plate 10a. However, the present invention is not limited to this. Not something.

As shown in FIG. 2, the condensing section 10b
The CCFT 2 is arranged at a central part inside the light collector, and the inner surface of the light collector 10b becomes a reflection surface, and
Light emitted from T2 is focused on the right end face of the light guide plate 1. The light condensing part 10b is a CCFT2
Extend from one end 2a to the other end 2b. The surface of the metal plate serving as the lamp reflector 10 may be subjected to a surface treatment such as polishing in order to increase the reflectance. Then, the condensing unit 10b
The upper and lower ends are narrowed down and formed into a cylindrical shape to form support portions 10c and 10c. The two support portions 10c, 10c correspond to the ends 2a, 2b of the CCFT, respectively. Then, the supporting portions 10c, 10 provided at both upper and lower ends of the light collecting portion 10b.
c is a shape in which one portion of the cylindrical portion is cut off,
That is, when the plate is bent into a cylindrical shape, both ends of the plate are not joined, and the supporting portions 10c, 10c
The diameter can be increased by the elastic deformation of the metal forming c.

The diameter of the supporting portions 10c, 10c is CC
Both ends 2a and 2b of the FT2 are slightly smaller than the outer diameters of the two ends 2a of the CCFT2.
a and 2b are respectively inserted into the supporting portions 10c and 10c.
When c is slightly expanded by elastic deformation, CCFT2
Can be inserted and the biasing force of the elastically deformed support portions 10c, 10c allows the two ends 2 of the CCFT 2 to be inserted.
a, 2b are sandwiched and fixed between the support portions 10c, 10c.

It should be noted that CCFT2 is provided on the supporting portions 10c and 10c.
When attaching the CCFT2, for example, the CCFT2 is inserted from one of the support portions 10c, and the leading end 2a of the CCFT2 is inserted.
May be extended to the other supporting portion 10c, or the above-mentioned separated portion of the supporting portion 10c may be widely opened, and both ends 2a, 2b of the CCFT 2 may be opened from this portion.
May be put in the support portions 10c and 10c.

As shown in FIG. 2, the conductive layer 11 includes a first insulating film (insulating layer) 11a attached to the outer surface of the light condensing portion 10b of the lamp reflector 10, and a first insulating film 11a on the first insulating film. Copper foil (conductor layer) 11b attached and copper foil 1
Second insulating film (insulating layer) 11 affixed on 1b
c is formed in a stacked state, and one support portion 10c of the light collecting portion 10b is connected to the other support portion 10c.
It is arranged so that it may extend to. In addition, copper foil 11b
Is narrower than the first and second insulating films 11a and 11c, and both surfaces of the copper foil 11b are
Except for 10c, the first and second insulating films 11
a, 11c, and the copper foil 11b is insulated from surrounding members.

The supporting portions 10c, 1
In a portion of 0c, that is, at both ends of the conductive layer 11, the copper foil 11b is exposed from the second insulating film 11c. FIG. 3 shows an exposed portion of the copper foil 11b on one end side of the conductive layer 11. Then, at one end of the conductive layer 11, as shown in FIG. 3, the common lead 12 is soldered to the exposed portion of the copper foil 11b, and one end 2a of the conductive layer 11 and the CCFT 2 is formed.
Are connected by a common lead 12.

At the other end of the conductive layer 11, a common wiring 4a is soldered to the exposed portion of the copper foil 11b, and the common side of the conductive layer 11 and the inverter 4 is connected by the common wiring 4a. Therefore, the electrode of one end 2a of the CCFT 2 and the common side of the inverter 4 are connected to the outer surface of the light condensing portion 10b of the lamp reflector 10 by the CCFT 2
Are connected by a conductive layer 11 extending along
The wiring from the electrodes at both ends 2a and 2b of the CCFT 2 is collected at one end of the CCFT 2 and connected to the inverter 4 without pulling the wiring cable from the electrode of the one end 2a of the CFT 2 to the inverter 4. I can do it.

The insulating films 11a, 11c
Any film may be used as long as it has a high insulating property, and the well-known insulating films 11a and 11c can be used. The caps 13, 13 are made of rubber and formed in a closed cylindrical shape, and are adapted to cover both ends 2a, 2b of the CCFT 2, respectively.
b, the electrodes at both ends 2a and 2b and the soldered portions are protected.

Next, the operation of the backlight device having the above configuration will be described. As described above, the lamp reflector 10 is made of metal in order to increase the thermal conductivity, and the lamp reflector 10 having the electrode which is most likely to generate heat of the CCFT 2 is used.
Since the end portions 2a and 2b of the CFT 2 are in contact with the support portions 10c and 10c of the lamp reflector 10, C
The heat generated from the CFT 2 is efficiently transmitted from the support portion 10c of the lamp reflector 10 to the lamp reflector 10, and is radiated in the lamp reflector 10, so that heat is prevented from being trapped in the CCFT 2 portion of the backlight device. When heat is trapped in the CCFT 2 portion, it is possible to prevent the occurrence of temperature unevenness in the liquid crystal display having the backlight device, thereby affecting display quality.

The plate portion 1 of the lamp reflector 10
By increasing the area of Oa, for example, by making the plate portion 10a cover the back surface of the light guide plate 1, the surface area of the lamp reflector 10 can be increased and the efficiency of heat radiation by the lamp reflector 10 can be increased. The plate 10
a so as to cover the back surface of the light guide plate 1,
2 is conducted to the entire back surface of the light guide plate 1, and it is possible to prevent the temperature distribution from being uneven in the backlight device. In addition, if the plate portion 10a also serves as the back plate of the liquid crystal display case as described above, the rear surface of the plate portion 10a is not covered with the liquid crystal display case and is in an exposed state.
The efficiency of heat radiation can be further increased.

As described above, the lamp reflector 10
Since the CCFT 2 is fixed to the supporting portions 10c and 10c of the liquid crystal display, and the positional relationship between the CCFT 2 and the lamp reflector 10 is determined in a predetermined arrangement, the arrangement of the CCFT 2 and the lamp reflector 10 in the liquid crystal display case is changed to a predetermined arrangement. Since the relative position between the lamp reflector 10 and the CCFT 2 can be determined without providing a fixed support portion for holding the backlight unit or using other fixed support members, the manufacturing cost of the backlight device can be reduced, and The light device manufacturing operation can be made more efficient.

That is, the lamp reflector 10 and the CCF
T2 can be easily integrated into a unit without using other members. If the light guide plate 1 is also fixedly supported by the lamp reflector 10, the light guide plate 1, CCFT
2 and the lamp reflector 10 can be easily integrated into a unit without using other members.

The condensing section 10 of the lamp reflector 10
b, a thin conductive layer 11 is provided on the outer surface, and when wiring is performed from the electrode at one end 2a of the CCFT 2 to the other end, the thin conductive layer 11 functions as a wiring. No space is required for wiring. Therefore, even if wiring is performed from the electrode at one end 2a of the CCFT 2 to the other end through the outside of the lamp reflector 10, a wiring space is provided outside the light condensing portion 10b of the lamp reflector 10. For this reason, the width of the frame portion of the liquid crystal display is not increased by increasing the width of the backlight device, and the frame of the liquid crystal display can be narrowed.

In the above example, the insulated conductive layer 11 is formed on the outer surface of the light condensing portion 10b of the lamp reflector 10, but the lamp reflector 10 itself may be used as the conductive layer 11. . That is, the lamp reflector 10 and the electrode at one end 2a of the CCFT 2 may be connected by the common lead 12, and the lamp reflector 10 and the inverter 4 may be connected by the common wiring 4a. In this case, it is preferable to take measures such as making the common side of the inverter a common ground (GND), and it is necessary to allow a current loss to occur.

[0043]

According to the backlight device of the first aspect of the present invention, while the heat of the light source is conducted to the reflection plate,
Since the heat conducted to the reflection plate is efficiently radiated from the reflection plate, it is possible to prevent the temperature distribution from being uneven in a display device such as a liquid crystal display having a backlight device. Thus, the display quality of a display device such as a liquid crystal display can be improved. Also, since the light source is supported by the reflector,
By simplifying the structure for supporting the light source, it is possible to increase the manufacturing efficiency and reduce the cost of the backlight device and the display device including the backlight device.

According to the backlight device of the second aspect of the present invention, the light source is supported by the support of the reflector, and the positional relationship between the reflector and the light source is determined. A member that determines the position of the reflector and the light source is not required, and the light source is supported by the support of the reflector and the reflector and the support can be housed in the case in an integrated state. Can be simplified and the number of parts can be reduced. Therefore, the manufacturing cost of the backlight device and a display device such as a liquid crystal display having the backlight device can be reduced, and the efficiency of the manufacturing operation can be improved. Also,
By reducing the number of members, a space can be omitted, and the size of a backlight device and a display device such as a liquid crystal display including the backlight device can be reduced.

According to the backlight device of the third aspect of the present invention, since the light source is in contact with the supporting portion, it is possible to prevent the temperature distribution from being uneven in the liquid crystal display having the backlight device. The display quality can be improved, and the light source is supported by the support portion of the reflection plate, so that the reflection plate and the light source can be integrally unitized, so that the production cost can be reduced, the work efficiency in production can be improved, and The size can be reduced. In addition, both ends of the condensing portion of the reflector are formed as support portions which are narrowed down so as to sandwich the light source, and this support portion supports the light source and comes into contact with the light source, so that the configuration is extremely simple. Thus, the above-described effects can be achieved.

According to the backlight device of the fourth aspect of the present invention, since the reflecting plate is provided with the plate portion extending to the back surface side of the light guide plate, the area of the reflecting plate is increased, and the reflecting plate is used. The above-described heat dissipation efficiency can be improved. In addition, if the plate portion is provided over substantially the entire back surface of the reflector, when heat generated from the light source is conducted by the reflector, heat is conducted to almost the entire surface of the backlight device. In addition, unevenness in the temperature distribution in the backlight device can be further reduced. Further, the reflection plate may constitute a back portion of a case of a display device such as a liquid crystal display having a backlight device, and in this case, the plate portion of the reflection plate is exposed on the back surface of the liquid crystal display. And the efficiency of heat dissipation by the reflector can be further improved.

According to the backlight device of the fifth aspect of the present invention, the reflecting plate functions as a wiring cable arranged from one end to the other end of the fluorescent tube. Space can be omitted, the size of the backlight device can be reduced, and a display device such as a liquid crystal display having the backlight device can be reduced in size. By reducing the width of the frame portion, the frame of the liquid crystal display can be narrowed.

According to the backlight device of the sixth aspect of the present invention, the thin film-like conductive layer serves as a wiring cable arranged from one end to the other end of the light source. Since the space for the wiring cable can be omitted, the size of the backlight device can be reduced, and the size of the liquid crystal display having the backlight device can be reduced. The width of the frame portion of the display device can be reduced, and the frame can be narrowed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an essential part showing a backlight device according to an example of an embodiment of the present invention without a light guide plate.

FIG. 2 is a sectional view taken along the line BB of FIG. 1;

FIG. 3 is a main part side view showing a supporting portion of a lamp reflector of the backlight device of the above example.

FIG. 4 is a partially exploded perspective view showing a conventional backlight device.

FIG. 5 is a cross-sectional view of a main part showing a conventional backlight device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light guide plate 2 CCFT (cold cathode fluorescent tube) 2a one end of CCFT 2b other end of CCFT 4 inverter (power supply for driving CCFT) 10 lamp reflector (reflection plate) 10a plate 10b light collector 10c support 11 conductive layer 11a first insulating film (insulating layer) 11b copper foil (conductor layer) 11c second insulating film (insulating layer)

Claims (6)

[Claims] 1. A backlight device for illuminating a display screen of a display device from a back surface side, comprising: a light source forming a tubular body; a light guide plate for guiding light projected from the light source to the display screen side; Surrounding the periphery except for the part facing the light guide plate,
A backlight device, comprising: a reflector for reflecting light projected from the light source and condensing the light on the light guide plate, wherein the reflector is made of metal and supports the light source. 2. The backlight device according to claim 1, wherein a support portion that supports both ends of the light source and determines a positional relationship between the reflector and the light source is provided on the reflector. . 3. The light-reflecting plate includes a cylindrical light-collecting portion that surrounds the light source and has an opening at a portion facing the light-guide plate, and the support portion includes the light-collecting portion. It is formed in a shape narrowed down so as to sandwich both ends of the light source at both ends of the light source, and the light source is held by the reflector by the support portion, and the reflector contacts the light source at the support portion. The backlight device according to claim 2, wherein the backlight device is provided. 4. The light guide plate according to claim 1, further comprising: a plate portion connected to the light-collecting portion and extending to a rear surface side of the light guide plate. The backlight device as described in the above. 5. The reflection plate is provided so as to extend from one end of the light source to the other end, and on one end side of the light source, the electrode at one end of the light source is connected to the electrode. 3. The light source according to claim 1, wherein the light source is connected to a reflector, and the reflector serves as a conductor for connecting an electrode at one end of the light source to a power source at the other end of the light source. 5. The backlight device according to 3 or 4. 6. A thin film conductive layer in which a conductor layer is laminated between two insulating layers is provided on the outer surface of the reflector so as to extend from one end to the other end of the light source. On one end side of the light source, an electrode at one end of the light source is connected to the conductive layer, and at the other end side of the light source, the conductive layer is connected to a power supply. The backlight device according to claim 1, 2, 3, or 4, wherein