JP2003107468A - Backlight device and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backlight device with a low profile and capable of reducing noise and to provide a liquid crystal display device using the backlight device. SOLUTION: The backlight device includes a backlight emission face, a backlight incidence face, a frame FR enclosing the backlight incidence face and the backlight emission face, and a couple of feeding harness wires 5A, 5B contained inside the frame FR and led out from both ends, and is provided with a thin and long backlight lamp 5 so that the one feeding harness wire 5A is directly led out externally from the inside of the frame FR and the other feeding harness wire 5B is looped back in the frame FR and led out externally, and light is made incident from the backlight incidence face Y.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device using an elongated backlight lamp and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art Backlight devices include direct type and edge type.

A conventional backlight device will be described with reference to FIGS.

FIG. 13 is a sectional view of an edge type backlight device. This backlight device includes a back frame 101, a light guide plate 102, a diffusion sheet 103, a lens sheet 104, a backlight lamp 105, a gutter-shaped reflection holder 106, and a front frame 107.

The back frame 101 is formed by molding a metal plate into a shallow plate shape, and has a wiring storage rib 101a on the back surface thereof.
Is attached by welding.

The light guide plate 102, the lens sheet 103, and the diffusion sheet 104 are stacked on each other to form the back frame 101.
It is housed inside.

The backlight lamps 105 are fluorescent lamps, and two lamps are paired and arranged on opposite sides of the light guide plate 102 in the back frame 101. In addition, a pair of power supply harness wires is led out from the back frame to the outside from both ends of each backlight lamp 105, and the other power supply harness wire 105B is housed in the wiring housing rib 101a, and one power supply harness is not shown. The wires are connected to a connector (not shown).

The gutter-shaped reflection holder 106 surrounds the two backlight lamps 105.

The front frame 107 has a frame shape and covers the opening of the back frame 101.

FIG. 14 is a perspective view showing another structure of the edge type backlight device. In this backlight device, a reflection sheet 108 is provided on the back surface of the light guide plate 102, and a diffusion sheet 104 is overlaid on the front surface of the light guide plate 103. Further, the backlight lamp is one although not shown. One and the other power supply harness line 1
05A and 105B are connected together and connected to the connector 105C.

FIG. 15 is a sectional view showing still another structure of the edge type backlight device. In this backlight device, the other two power supply harness wires 105B are housed in the wiring rib 101a.

FIG. 16 is a sectional view showing still another structure of the edge type backlight device. In this backlight device, the back frame 101 is formed by molding synthetic resin, and the wiring rib 101a is also integrally molded. The other structure is the same as that of FIG.

FIG. 17 is an exploded perspective view of a direct type backlight device. This direct type backlight device includes a back frame 111, a reflector 112, and a backlight lamp 1.
13, a diffusion plate 114 and a front frame 115 are provided.

The back frame 111 has a shallow dish shape as in the side type backlight device,
Notches 111a and 111b are formed on both sides of the two opposite side edges.

The reflecting plate 112 is provided with a plurality of concave reflecting surfaces arranged in parallel, and is housed in the bottom portion of the back frame 111.

A plurality of the backlight lamps 113 are arranged in the concave reflection surface of the reflection plate 1112, and a pair of power supply harness wires 113A and 11 are provided from both ends.
3B has been derived. One power supply harness line 113A
Are led out as they are from the notch 111 a of the back frame 111. On the other hand, the power supply harness wire 11
3B is led out from the notch portion 111b of the back frame 111, is led out obliquely forward in the drawing along the side surface of the back frame 111, becomes the power supply harness wire 113A, and is connected to a connector not shown.

The diffusion plate 114 is a backlight lamp 11.
It is located at the top of 3.

The front frame 115 has a frame shape and covers the opening of the back frame 101.

[0019]

However, the thinning of the backlight device has recently been required along with the thinning of the display screen of the device incorporating the backlight device, and the above-mentioned backlight device cannot meet this demand. There is a problem. There is also a problem that the radiation noise is large. That is, the harness wire storage ribs provided on the outer surface of the frame for routing the power supply harness wire on the back surface of the back frame and the wire hooking protrusions instead of the ribs hinder the reduction in thickness and increase the radiation noise. . The arrow n in FIG. 13 indicates the radiation of noise. Therefore, although the back frame is made of metal or is made of synthetic resin containing metal fibers, it has not been sufficiently effective.

It is an object of the present invention to provide a thin backlight device and a liquid crystal display device using the same.

Another object of the present invention is to provide a backlight device which reduces radiation noise and a liquid crystal display device using the same.

[0022]

According to another aspect of the present invention, there is provided a backlight device including: a backlight light emitting surface; a backlight light incident surface; a frame surrounding the backlight light incident surface and the backlight light emitting surface. A pair of power supply harness wires housed inside the frame and led out from both ends, one power supply harness wire being led out directly from inside the frame, and the other power supply harness wire being folded back inside the frame And an elongated backlight lamp arranged so that light is incident from the backlight light incident surface.

In the present invention and each of the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.

<Backlight Light Emitting Surface> The backlight light emitting surface is a surface which produces a light output as a backlight device, and whether or not a specific member is present is not a requirement. Therefore, in the direct type backlight device, it may be a simple space. However, if necessary, in order to improve the uniformity of the luminance distribution, a member for improving optical characteristics such as a light curtain and / or a diffusing plate described later, or a transparent conductive film member for suppressing radio noise emission is used. A structure in which a backlight light emitting surface is formed on the front surface is allowed.

Further, in the case where the backlight device is an edge type backlight device, the backlight light emitting surface can be formed on the front surface side of the transparent light guide plate. In addition,
“Front side” of the transparent light guide plate means a mode in which a backlight light emitting surface is directly formed on the front surface of the transparent light guide plate, and a diffuser plate and a member for improving optical characteristics such as a lens sheet described later are arranged on the front surface of the transparent light guide plate. It is meant to include any of the modes in which the backlight light emitting surface is indirectly formed on the front surface of the transparent light guide plate via them.

<About Backlight Light Incident Surface> The backlight light incident surface is a surface on which the light emission of a discharge lamp, which will be described later, is incident in order to generate light output as a backlight device on the backlight light exit surface. It is not a requirement that a particular member be present. Therefore, in the direct type backlight device, it may be a mere space directly facing the backlight light emitting surface.

Further, in the case where the backlight device is an edge type backlight device, the backlight light incident surface can be formed on the side surface of the transparent light guide plate. If the transparent light guide plate is, for example, a quadrangle, the side surface of the transparent light guide plate has four surfaces around the front surface.
A backlight light incident surface can be formed on the surface. The remaining side surface can act as a reflection surface for the light incident from the backlight light incident surface. For that purpose, the reflecting means may be closely attached to the remaining side surface.

<Regarding the Frame> The frame houses a backlight backlight lamp. Further, the frame surrounds the backlight light incident surface and the backlight light incident surface, and optical means such as a light guide, a lens sheet, and a diffusion sheet arranged between the incident surface and the emission surface. In the case where optical means such as a reflection sheet and a reflection plate are additionally provided, these optical means are also housed inside. Further, means for utilizing a backlight such as a liquid crystal display means is arranged on the front surface of the frame.

Further, the frame can be constructed by using an appropriate material such as metal or synthetic resin. However, radiation noise is reduced by using a material or metal in which metal fibers are dispersed in a synthetic resin.

Further, the frame can be formed substantially integrally as a whole. Further, the back frame and the front frame may be formed so as to overlap each other, and the specific structure thereof is not limited.
Further, the frame is provided with a means for leading out a pair of power supply harness wires of the backlight lamp, such as a cutout portion. In the aspect in which the cutout portion is formed as the means for leading out the power supply harness wire, the cutout portion is arranged on one side of the frame, but may be single or two.

<Backlight Lamp> The backlight lamp is elongated and accommodated inside the frame, and is provided with a pair of power supply harness wires led out from both ends. And it acts as a light source as a backlight. The backlight lamp may have any light emitting principle as long as it is formed in an elongated shape. For example, it may be any of a discharge lamp, a light emitting diode, an incandescent lamp, and the like. However, the discharge lamp is preferable because it is easy to obtain the required light amount and light color. The discharge lamp includes a long and thin translucent discharge vessel in which both ends are internally sealed with electrodes.
It is possible to use those adopting various configurations such as an inner-outer electrode type mode in which one electrode is sealed as an inner electrode inside one end and the other electrode is arranged as an outer electrode on the outer surface of the translucent discharge vessel. .

The backlight lamp is housed at a predetermined position inside the frame, one power supply harness wire is led out from the frame directly to the outside, and the other power supply harness wire is folded back inside the frame to the outside. Have been derived to.

Further, in the backlight lamp, related components such as a rubber band and a gutter-shaped reflection holder can be integrally attached to the lamp as an assembly. The rubber bands are attached to both ends of the lamp, and can be used when the lamp is buffered and fixed to the gutter-shaped reflection holder. The gutter-shaped reflection holder functions to mount the lamp at a predetermined position inside the frame, and reflects the light emitted from the lamp body in a direction other than the predetermined direction in a predetermined direction to increase the brightness on the backlight light emitting surface. It has a function.

<Other Configurations of Backlight Device> Although not an essential component of the present invention, the performance of the backlight device and the function thereof can be improved by selectively adding the following configurations. it can.

1. Reflector or gutter-shaped reflection holder In the case of a direct type backlight device, a reflector can be arranged on the back side of the discharge lamp. The reflecting plate may be formed with a concave reflecting surface that surrounds substantially the latter half of the backlight lamp so as to enhance the reflection efficiency.

In the case of the edge type backlight device,
The periphery of the discharge lamp including the rear side can be surrounded by the gutter-shaped reflection holder except for the side surface of the light guide.

The above-mentioned reflecting plate or trough-like reflecting holder reflects the light emitted from the discharge lamp and not directly incident on the backlight light incident surface, thereby improving the light incident efficiency on the backlight light incident surface and spreading it. As a result, it is possible to increase the brightness on the backlight light emitting surface.

2 Reflection Sheet In the edge type backlight device, the reflection sheet is in contact with the back surface of the light guide body to reflect the light emitted from the back surface of the light guide body so that the light exit surface side. It is a means to reflect to.

3 Regarding Optical Property Improving Member An optical property improving member such as a light curtain, a diffusing plate (or a diffusing sheet), and a lens sheet may be provided on the backlight light emitting surface individually or in combination as needed. You can The term "light curtain" means, in a direct-type backlight device, means for suppressing the incidence of direct light of a discharge lamp on a backlight light incident surface, and thus the disturbance of the luminance distribution due to the direct light on the backlight light emitting surface. And, for example, polycarbonate resin or PET
For example, a thin film having a light shielding property, a reflective property, or a light diffusing property, which is made of a resin such as a transparent synthetic resin film having a thickness of about 0.5 mm, facing the backlight lamp is covered by an appropriate means such as printing, vapor deposition, or sticking. What has a worn construction can be used. Further, the "diffusion plate" is a means for diffusing light that is going to be emitted from the backlight light emitting surface immediately before it, for example, printing and spraying a light diffusing coating on the surface of a transparent synthetic resin film, Brushed,
It can be composed of a member deposited by a method such as vapor deposition, a light diffusing film, a light diffusing glass plate, or the like. further,
The "lens sheet" is composed of a large number of minute continuous wavy surfaces arranged and collects light rays passing through the wavy portion to correct the incident angle to the light incident surface of the liquid crystal display unit, It has the effect of increasing the incident light amount and increasing the incident efficiency.

Regarding the transparent conductive coating member, when the discharge lamp is used as the backlight lamp, the radiant noise generated from the discharge lamp is external from the backlight light emission surface. Is a coating member that suppresses light emission to the extent possible but does not hinder light transmission as much as possible. For example, an ITO (indium oxide and tin oxide) film or other transparent film is formed on the surface of a transparent synthetic resin film such as PET resin. A member coated with a conductive conductive coating can be used.

6 Discharge Lamp Lighting Device The discharge lamp lighting device can be integrally incorporated in the backlight device. The discharge lamp lighting device has a configuration in which a high frequency AC voltage or a high frequency pulse voltage is applied to light the discharge lamp so that the current limiting impedance does not have to be interposed in series or not as in the case of the dielectric barrier discharge. It is preferable because the circuit configuration is small and lightweight and the discharge lamp can be lit with high luminous efficiency.

<Regarding the Operation of the Present Invention> In the present invention, one of the pair of power supply harness wires led out from both ends of the backlight lamp is directly folded and the other is folded back in the frame, and both are led out from the frame. Therefore, it is not necessary to provide a wiring housing rib or a wiring hooking projection for routing the power supply harness wire outside the back surface of the frame, and thus the backlight device can be made thin.

Further, the radiation noise is reduced by forming the frame using a synthetic resin or the like having a noise-cutting function such as containing metal or metal fiber.

Further, the backlight device of the present invention has the above-mentioned effects and is suitable as a backlight device of a liquid crystal display device. However, the present invention is not limited to this, and is applicable to backlight devices in all applications.

A backlight device according to a second aspect of the present invention is the backlight device according to the first aspect, further comprising a light guide; the backlight light emitting surface is formed on the front side of the light guide. The light incident surface of the backlight is formed on the side surface of the light guide body, and is configured to be a side type.

The present invention defines the configuration of the edge type backlight device.

The light guide member is an effective means for performing surface illumination by emitting light from one surface while repeating the total internal reflection from the incident side surface to the opposite side surface while repeating the progress. Therefore, there is a feature that the backlight device can be made thin. The thickness of the light guide body can be appropriately changed in order to improve the uniformity of the luminance distribution on the light emitting surface.

Further, the brightness of the light emitting surface can be increased by increasing the light reflectance on the back surface side with respect to the front surface serving as the light emitting surface or by disposing the reflecting means on the opposite side surface. . In order to increase the reflectance on the back side, for example, a reflection sheet may be provided or a back surface may be coated with a reflection film. In this case, by changing the reflectance from the incident side surface to the opposite side surface, the luminance distribution on the emission surface can be balanced.

Further, the light guide body is transparent and can be constructed by using, for example, a transparent acrylic resin plate.

The backlight lamp can be arranged on one side or plural sides of the side surface of the light guide. When arranging the backlight lamps on the adjacent two or three side surfaces, an L-shaped or U-shaped backlight lamp can be used. However, if necessary, different backlight lamps can be used for each side.

A backlight device according to a third aspect of the present invention is the backlight device according to the third aspect, wherein the backlight lamp is integrally provided with a gutter-shaped reflection holder for accommodating the backlight lamp, and the other power supply harness. The line is flat,
In addition, the lamp assembly is characterized by being bonded to the outer surface of the gutter-shaped reflection holder.

The present invention defines a backlight lamp as a lamp assembly suitable for an edge type backlight device. That is, the lamp assembly includes at least a backlight lamp, a gutter-shaped reflection holder, and one power supply harness wire.

The trough-shaped reflection holder has a concave inner surface, for example, a cross section having a reflection surface such as a parabolic surface, a hemispherical surface or a U-shaped surface, and the backlight lamp is housed inside the reflection surface. It is in a state of being supported in a closed state, and both are integrated. For integration, for example, a pair of rubber bands are attached to both ends of the backlight lamp in the longitudinal direction, and the rubber bands are bonded to a reflection holder to hold them in a predetermined positional relationship and integrate them. be able to.

In addition, the gutter-shaped reflection holder can be arranged, for example, by sandwiching the side surface portion of the light guide plate between both edges of the gutter-shaped reflection holder when the backlight lamp is arranged at a predetermined position with respect to the light guide. , Can be used as an attachment means.

In one of the power supply harness wires, at least a portion bonded to the outer surface of the gutter-shaped reflection holder, that is, the back surface of the reflection surface is formed flat. However, the back of the reflective surface is
It may be at a position that substantially faces the side surface of the light guide plate, or at a position that is substantially parallel to it. In addition, if the adhesive portion is covered with an insulating film, the insulating process becomes easy.

Thus, in the present invention, by using the assembly including the backlight lamp, the gutter-shaped reflection holder, and the one power feeding holder, the backlight lamp can be easily assembled and the light incidence efficiency can be improved. In addition, the space for routing the power supply harness wire is significantly reduced, and a thinner edge-type backlight device can be obtained.

A backlight device according to a fourth aspect of the present invention is the backlight device according to the first aspect, wherein the backlight light incident surface is directly opposed to the backlight light emission surface, and the backlight device is of a direct type. It is characterized by that.

The present invention defines the structure of a direct type backlight device.

A light diffusing means such as a light diffusing plate may be provided between the light emitting surface and the light incident surface in order to improve the uniformity of the luminance distribution on the light emitting surface.

In order to maximize the uniformity of the luminance distribution on the light emitting surface of the backlight lamp, it is preferable that a plurality of light emitting portions thereof are evenly arranged and, for example, a straight tube fluorescent lamp is used. Arranged in multiple places, U
One or a plurality of fluorescent lamps bent in a letter shape or a meandering shape can be used.

Further, in order to effectively reflect the light emitted from the backlight lamp in a direction other than the direction of the light emitting surface, a reflecting plate can be provided on the back side of the backlight lamp. As the reflecting plate, one having a concave reflecting surface formed so as to surround the light emitting portion of the backlight lamp can be used.

Furthermore, the space or gap formed between the frame and the reflector can be used to route the other power supply harness line of the backlight lamp inside the frame. In this case, it is possible to further reduce the radiation noise by using a reflection plate having a radiation noise blocking property such as a synthetic resin added with metal or metal fiber or a synthetic resin coated with a metal reflection film. it can.

Thus, in the present invention, since it is of the direct type, it is possible to obtain a backlight device which is relatively thin, has reduced radiation noise, and has high brightness on the light emitting surface.

A liquid crystal display device according to a fifth aspect of the present invention comprises the backlight device according to any one of the first to fourth aspects, and a liquid crystal display means provided on a backlight light emitting surface of the backlight device. It is characterized by having.

The present invention defines a liquid crystal display device most suitable for use as a backlight device.

Thus, in the present invention, since the dark portions appearing at both ends of the discharge lamp do not appear as uneven brightness on the backlight light emitting surface, it is preferable to increase the size of the liquid crystal display surface with respect to the external size. A display screen with a wide brightness distribution can be obtained.

[0067]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an edge type backlight device and an edge type backlight type liquid crystal display device as a first embodiment of a backlight device and a liquid crystal display device of the present invention, and FIG. 1 is a sectional view. 2 is an enlarged cross-sectional view of a main part of the backlight lamp. That is, the edge type backlight device includes a back frame 1, a light guide plate 2, a diffusion sheet 3, a lens sheet 4, a backlight lamp 5, a gutter-shaped reflection holder 6 and a front frame 7. The edge type backlight type liquid crystal display device includes an edge type backlight device, a liquid crystal display unit LCD and a lighting circuit (not shown). The liquid crystal display unit LCD is arranged on the front surface of the front frame 7.

The back frame 1 forms a frame FR in cooperation with a front frame 7 which will be described later, and accommodates each component described later therein. Also, the back frame 1
Is a pair of wiring accommodating ribs 1 formed by molding a metal plate into a shallow dish, and attached by welding to the substantially central portion of the inner surface thereof.
a, 1a.

The light guide plate 2, the diffusion sheet 3 and the lens sheet 4 are stacked and housed in the back frame 1. The light guide plate 2 is formed by molding a transparent acrylic resin,
The front surface is flat, but the back surface is formed in a slanting surface in which the center between the pair of opposed side surfaces is the thinnest and the thickness gradually increases toward both side surfaces. The pair of side surface portions face the inner surface of the side edge of the back frame 1. In addition,
The wiring housing rib 1a is arranged so as to be accommodated in a mountain-shaped space sp formed by the central portion of the back surface of the light guide plate 2.

The backlight lamp 5 is a cold cathode fluorescent lamp, as shown in FIG. That is, the cold cathode fluorescent lamp has an internal electrode type arrangement, and the translucent airtight container L
An SE, an introduction line LW, a pair of internal electrodes IE, IE, and a phosphor layer F are provided.

The light-transmissive airtight container LSE is made of a long glass valve whose both ends are hermetically sealed, and a small amount of mercury and a noble gas are enclosed therein as a discharge medium.

The lead-in line LW is sealed by penetrating both ends of the transparent airtight container LSE.

The pair of internal electrodes IE, IE are made of a cylinder of Ni, an electron emissive material, etc., and constitute a cold cathode.

The phosphor layer F is mainly composed of, for example, a three-wavelength light emitting phosphor, and has a light-transmitting hermetic container LS.
It is formed on the inner surface side of E.

By the way, the back playing card 5 is
Lights are arranged in pairs in the back frame 1 so as to face a pair of opposing side surfaces of the light guide plate 2, respectively, and the generated light enters the inside from the side surfaces of the light guide plate 2. Further, a pair of power supply harness wires is led out from both ends of each backlight lamp 5, and the other power supply harness wire 5B is connected to the wiring housing rib 1a inside the back frame 1.
By being housed in the back frame, it is folded back in the back frame, combined with one power supply harness wire (not shown), and then led out to the outside from the notch formed in the side surface (not shown) of the back frame 1. Further, the tip is connected to a connector (not shown).

The gutter-shaped reflection holder 6 is formed in a U-shaped cross section by molding a material in which a metal vapor deposition film such as silver is formed on a transparent synthetic resin film to form a reflection surface. Then, by housing the two backlight lamps 5 inside, the backlight lamp 5 is surrounded, and the light guide plate 2 is opened laterally so that its opening portion is horizontal.
Close to the sides of.

The front frame 7 has a frame shape, and its side edges cover the opening of the back frame by being fitted into the opening of the back frame 101 from the outside.

Thus, the front surface of the front frame 7 constitutes the backlight light emitting surface X, and the side surface of the light guide plate 2 constitutes the backlight light incident surface Y.

FIGS. 3 and 4 show radiation noise measurement data in the first embodiment of the backlight device of the present invention, FIG. 3 is data at a frequency of 35 kHz to 1.6 MHz, and FIG. 4 is at a frequency of 2 to 30 MHz. The data.

5 and 6 show radiation noise measurement data in the conventional backlight device shown in FIG. 12, FIG. 5 is data at frequencies of 35 kHz to 1.6 MHz, and FIG. 6 is data at frequencies of 2 to 30 MHz. Is. 3 to 6, the horizontal axis represents frequency and the vertical axis represents noise level.

By comparing FIGS. 3 and 5 with FIGS. 4 and 6, it can be understood that the radiation noise is reduced in the present invention.

Another embodiment of the present invention will be described below with reference to FIGS. 7 to 12. In each figure, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

7 and 8 show a backlight lamp in an edge type backlight device as a second embodiment of the backlight device of the present invention, and FIG. 7 is a front view,
It is a front sectional view and a circuit diagram showing a lighting circuit.

In each drawing, OE is an external electrode, LI is a translucent insulating coating, and OC is a lighting circuit.

Inside the transparent airtight container LSE, a discharge medium made of a rare gas mainly containing xenon is enclosed.

The internal electrode IE is sealed inside one end of the transparent airtight container LSE.

The external electrode OE is formed by winding a Ni wire having a wire diameter of 0.1 mm in a coil shape, and its inner surface is arranged in contact with the outer peripheral surface of the light-transmitting hermetic container LSE. Then, the winding start portion a is fixed, and the translucent airtight container L
The SE is rotated to wind at a predetermined pitch, and the winding end portion is extended to form the connection portion b. The connecting portion b is connected to a lead wire 1 in which the base is embedded at the other end of the translucent airtight container LSE by soldering.

The translucent insulating coating IL is formed by heating a transparent heat-shrinkable fluororesin sheet and shaping it into a tube shape. The translucent airtight container LSE is coated from the outside of the external electrode OE to discharge the lamp. Is configured.

The lighting circuit OC is connected between the lead-in line LW and the lead wire 1 of the transparent airtight container LSE. It is composed of an inverter and outputs a high frequency rectangular wave pulse voltage.

Next, the operation of the discharge lamp will be described.

Internal electrode IE and external electrode OE of the discharge lamp
From the lighting circuit OC to the lead wire LW and the lead wire l
When a high-frequency pulse voltage is applied via the
Xenon of the discharge medium enclosed in the discharge space of the transparent airtight container LSE due to the occurrence of a dielectric barrier discharge having the wall surface of the transparent airtight container LSE as a dielectric in the discharge space between E and OE. Emits ultraviolet rays. The ultraviolet rays irradiate the phosphors of the phosphor layer F, so that the phosphors are excited and emit visible light. That is, the wavelength of ultraviolet rays is converted into visible light.
The emitted visible light is guided to the outside of the translucent airtight container LSE over the entire circumference from the gap formed between the turns of the coil of the external electrode OE, so that the visible light can be used.

FIG. 9 shows a third embodiment of the backlight device of the present invention.
3 is an exploded perspective view showing an edge type as an embodiment of FIG.
The present embodiment is mainly different in that a reflection sheet 8 is provided.

That is, the reflection sheet 8 is formed in a mountain shape so as to be in contact with the back surface of the light guide plate 2, and is integrally formed with the pair of gutter-shaped reflection holders 6, 6.

The back rubber 9 (not shown) is fitted with a rubber band 9 at both ends thereof, and the rubber band 9 is adhered to the gutter-shaped reflective holder 6 so that the backlight lamp and the gutter-shaped reflective holders 6, 6 are provided. The reflection sheet 8 and the reflection sheet 8 are integrated to form a light emitting unit assembly L in advance.

Therefore, when assembling the backlight device, the backlight lamp,
The light emitting part assembly L including the gutter-shaped reflection holders 6 and 6 and the reflection sheet 8 is housed, then the light guide plate 2, the diffusion sheet 3 and the lens sheet 4 are sequentially incorporated into the light emitting part assembly L, and finally the front The frame FR may be assembled by fitting the frame 7 into the back frame 1.

Numeral 1b is a notch formed at both ends of the side edge of the back frame 1, and is a pair of power supply harness wires 5A and 5A.
Derive B. As shown in FIG. 1 on the inner surface of the backlight frame 1.
There is no wiring storage groove 1a in the above, and therefore the other power supply harness wire 5B is rolled into the mountain-shaped space formed between the back frame 1 and the reflection sheet 8. Also, 3
Reference numerals a, 3b, 4a, and 4b are positioning projections formed on the diffusion sheet 3 and the lens sheet 4, respectively. Furthermore, the four 5C are the one and the other of the power supply harness wires 5
A connector connected to the tips of A and 5B. Furthermore, 7a is a notch formed in the front frame 7, which is formed so as to face the notch 1b of the back frame 1 and leads out the pair of power supply harness wires 5A, 5B.

10 and 11 show an edge type backlight device as a fourth embodiment of the backlight device of the present invention, FIG. 10 is an exploded perspective view, and FIG. 11 is an enlarged sectional view of a light emitting section assembly. Is. In this embodiment, the light guide plate 2 is flat on both the front and back, the light emitting unit assembly L and the reflection sheet 8 are separate bodies, and the other power supply harness wire 5B is fixed to the back surface of the gutter-shaped reflection holder 6. The main difference is that The backlight device shown in FIGS. 1 and 9 is suitable for a device having a relatively large light emitting surface area, whereas the present embodiment is suitable for a device having a relatively small light emitting surface area.

That is, in the light emitting section assembly L, the backlight lamp (5) is one, and the other power supply harness line 5 is used.
As shown in FIG. 11, the middle portion of B is flat with a thickness of about 0.1 to 0.3 mm, and is attached to the rear surface of the gutter-shaped reflection holder 7 by a double-sided adhesive tape or an adhesive agent. It is fixed via B and is further covered with an insulating film IF. .

The back frame 1 is provided with one notch 1b at the center of one side edge and retreat 1c on both sides thereof. Then, the pair of power supply harness wires 5A, 5B is led out from the cutout portion 1B to the outside.

The reflection sheet 8 is provided with rising edges 8a and 8b facing each other from both ends thereof. A slit sl is formed on one rising edge 8a, and a locking protrusion ep is formed on the other rising edge 8b.

The light guide plate 2 and the diffusion sheet 3 have protrusions p.
And the groove g is formed on the opposite side edges, and the projection p
Is engaged with the slit sl of the reflection sheet 8 and the groove g is engaged with the locking projection ep, whereby the three members are positioned.

The front frame 7 is formed with a pair of notches 7b, 7b on both sides of the one side edge 7A, so that the one side edge 7A is fitted in the retracted portion 1c of the back frame 1.

FIG. 12 is an exploded perspective view showing a direct type backlight device as a fifth embodiment of the backlight device of the present invention. In the figure, 10 is a reflector, which is arranged inside the back frame 1 and has five concave reflecting surfaces 10a.
Is equipped with.

The backlight lamp 5 includes five reflectors 1.
It is housed inside the concave reflection surface 10a of No. 1 and arranged in parallel. The other power supply harness wire 5 of the backlight lamp 5
B is divided into two and is led to the outside from a pair of notches 1b and 1b formed in the side edge of the back frame 1. Note that one of the power supply harness wires is not shown.

[0106]

According to the invention of claim 1, the backlight light emitting surface, the backlight light incident surface, the frame surrounding the backlight light incident surface and the backlight light emitting surface, and housed inside the frame. Is provided with a pair of power supply harness wires derived from both ends, and one power supply harness wire is directly derived from the frame to the outside, the other power supply harness wire is folded back in the frame and is derived to the outside, By providing an elongated backlight lamp arranged so that light is incident from the backlight light incident surface, it is possible to provide a backlight device which is thin and which can also reduce radiation noise. .

According to the second aspect of the invention, in addition, the backlight light emitting surface is formed on the front surface side of the light guide body, and the backlight light incident surface is formed on the side surface of the light guide body. It is possible to provide a backlight device configured in accordance with the formula.

According to the third aspect of the present invention, in addition, the backlight lamp is integrally provided with the gutter-shaped reflection holder for accommodating the backlight lamp, and the other power supply harness wire is flat and the gutter-shaped reflection holder. By constructing the lamp assembly by adhering it to the outer surface of the, it is possible to provide a backlight device that can be easily assembled.

According to the invention of claim 4, since the backlight light incident surface is directly opposed to the backlight light emission surface, it is possible to provide a backlight device of a direct type.

According to the invention of claim 5, it is possible to provide a liquid crystal display device having the effects of claims 1 to 4.

[Brief description of drawings]

FIG. 1 is a sectional view showing an edge type backlight device as a first embodiment of a backlight device and a liquid crystal display device of the present invention.

[FIG. 2] Similarly, an enlarged sectional view of a main part of the backlight lamp.

FIG. 3 is a radiation noise measurement data having a frequency of 35 kHz to 1.6 MHz in the first embodiment of the backlight device of the present invention.

[Fig. 4] Similarly, radiation noise measurement data with a frequency of 2 to 30 MHz

FIG. 5: Radiation noise measurement data at a frequency of 35 kHz to 1.6 MHz in the conventional backlight device shown in FIG.

[FIG. 6] Similarly, radiation noise measurement data with a frequency of 2 to 30 MHz

FIG. 7 is a front view showing a backlight lamp in an edge type backlight device as a second embodiment of the backlight device of the present invention.

FIG. 8 is a front sectional view and a circuit diagram showing a lighting circuit.

FIG. 9 is an exploded perspective view showing an edge type backlight device according to a third embodiment of the present invention.

FIG. 10 is an exploded perspective view showing an edge type backlight device as a fourth embodiment of the backlight device of the present invention.

FIG. 11 is an enlarged cross-sectional view of the light emitting unit assembly.

FIG. 12 is an exploded perspective view showing a direct type backlight device as a fifth embodiment of the backlight device of the present invention.

FIG. 13 is a sectional view of a conventional edge-type backlight device.

FIG. 14 is a perspective view showing another configuration of the conventional edge-type backlight device.

FIG. 15 is a sectional view showing still another configuration of the conventional edge-type backlight device.

FIG. 16 is a cross-sectional view showing still another configuration of the edge type backlight device.

FIG. 17 is an exploded perspective view of a conventional direct type backlight device.

[Explanation of symbols]

1 ... Back frame 1a ... Wiring storage rib 2 ... Light guide plate 3 ... Diffusion sheet 4 ... Lens sheet 5 ... Backlight lamp 6 ... Gutter-shaped reflection holder 7 ... Front frame 9 ... Liquid crystal display unit FR ... frame X: Backlight light emission surface Y: Backlight light incident surface

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09F 9/00 336 G09F 9/00 336J 350 350Z // F21Y 103: 00 F21Y 103: 00

Claims (5)

[Claims] 1. A backlight light exit surface; a backlight light entrance surface; a frame surrounding the backlight light entrance surface and the backlight light exit surface; and a pair of housings housed inside the frame and led out from both ends. A power supply harness line is provided, and one power supply harness line is led out directly from the inside of the frame, and the other power supply harness line is folded back inside the frame and led out to the outside, and light is incident from the backlight light incident surface. And an elongated backlight lamp arranged as described above. 2. A light guide is provided; a backlight light emitting surface is formed on a front surface side of the light guide; and a backlight light incident surface is formed on a side surface of the light guide. The backlight device according to claim 1, wherein the backlight device is configured as a side type. 3. The backlight lamp is integrally provided with a gutter-shaped reflection holder for accommodating the backlight lamp, and the other power supply harness wire is flat and is adhered to the outer surface of the gutter-shaped reflection holder. The backlight device according to claim 2, wherein the backlight device constitutes an assembly. 4. The backlight device according to claim 1, wherein the backlight light incident surface is directly opposed to the backlight light emission surface and is of a direct type. 5. A backlight device according to any one of claims 1 to 4, and a liquid crystal display means arranged on a backlight light emitting surface of the backlight device. Liquid crystal display device.