JP4584051B2 - Backlight unit and liquid crystal display device having the backlight unit - Google Patents

Description

  The present invention relates to a backlight unit, for example, a backlight unit disposed on the back surface of a liquid crystal panel or the like and constituting an LCD (liquid crystal display) device, and a liquid crystal display device having the backlight unit.

In recent years, as the development of LCD devices for liquid crystal televisions and the like has become full-fledged, the demand for backlight units installed therein has further increased.
The backlight unit is roughly classified into an edge light method (also referred to as a side light method or a light guide plate method) in which a light guide plate is placed on the back surface of the LCD panel, and a fluorescent lamp is disposed on an end surface of the light guide plate. There are two types, a direct type in which a plurality of fluorescent lamps are arranged in parallel on the back surface of the LCD panel. When comparing the two, in general, the edge light method is excellent in thinning and luminance uniformity of the light emitting surface, but it is disadvantageous in terms of high luminance, while the direct method is excellent in terms of high luminance, but thin. It can be said that it is disadvantageous in terms of conversion.

In view of this, an LCD device used in a liquid crystal television set with an emphasis on high brightness often employs a direct method.
In the direct system, in order to reduce the number of fluorescent lamps used per unit, a bent fluorescent lamp bent in a U shape may be used instead of a straight fluorescent lamp. This is because the number of the fluorescent lamps can be reduced to about half when the bent fluorescent lamp is used, compared to the case where the straight tube fluorescent lamp is used.

Even though the number of screens is reduced, the number of fluorescent lamps used per unit tends to increase in a liquid crystal television with a large screen. Therefore, it is necessary to reduce the number of steps for assembling each fluorescent lamp to the unit body from the viewpoint of manufacturing cost. A backlight unit capable of reducing the man-hour is disclosed in Patent Document 1.
The backlight unit 200 of Patent Document 1 will be described with reference to FIG. As shown in FIG. 10A, the backlight unit 200 is a bent fluorescent lamp 204 having a glass bulb 202 bent in a U shape, and electrodes (external electrodes) are formed on the outer periphery of both ends thereof. There are four external electrode type fluorescent lamps. The four fluorescent lamps are arranged on the housing 208 side by side with the external electrodes on both ends aligned on the same side and in parallel.

  A plurality of lamp fixtures 210, 212, 214, 216, and 218 having one or two concave grooves having a U-shaped cross section at one end edge of the housing 208 and made of conductive metal are connected to the one end edge. Are arranged in line. The lamp fixtures 210 and 218 at both ends are lamp fixtures having one groove, and two lead wires 222 and 224 extending from the lighting circuit 220 are connected to each other. Further, as shown in FIG. 10B, the middle lamp fixtures 212, 214, and 216 are lamp fixtures having two grooves, and connect adjacent fluorescent lamps 204 in series. is there. A holding part 228 for holding the U-shaped bent part 226 of the fluorescent lamp is formed at the other end edge opposite to the one end edge.

In the backlight unit 200 having the above-described configuration, the four fluorescent lamps have the external electrodes 206 at both ends fitted to the lamp fixtures 210, 212, 214, 216, and 218, and the U-shaped bent portion 226 is provided. Since it can be assembled simply by fitting into the holding portion 228, the number of assembling steps can be reduced.
JP 2003-36703 A

However, in the conventional backlight unit 200, four fluorescent lamps 204 are lit in series, so that the brightness of the fluorescent lamp 204 closer to the center is lower than the fluorescent lamps 204 closer to both ends of the series connection. The luminance unevenness occurs in the entire backlight unit 200.
In order to suppress the luminance unevenness, the four fluorescent lamps 204 may be lit in parallel. In this case, the following method can be considered to improve the backlight unit 200 and connect the four fluorescent lamps in parallel. That is, the lamp fixtures 212, 214, 216 having two grooves are all changed to those having one groove, and the lead wires are provided between the lamp fixtures 210, 212, 214, 216, 218. It is conceivable to connect properly.

According to this, although the four fluorescent lamps 204 are connected in parallel, it takes time to solder the lead wires one by one, and the number of assembling steps for the entire backlight unit increases.
In view of the above-described problems, an object of the present invention is to provide a backlight unit capable of suppressing the number of assembling steps while a bent fluorescent lamp is connected in parallel, and a liquid crystal display device having the backlight unit.

  In order to achieve the above object, the backlight unit according to the present invention has a first metal conductor formed on the outer periphery of the first end of the U-shaped bent glass bulb, and the outer periphery of the second end. A backlight unit in which a plurality of fluorescent lamps each having a second metal conductor formed therein is arranged, and the first metal conductor provided corresponding to each fluorescent lamp is fitted into the first unit. Connector, a second connector into which the second metal conductor is fitted, and first and second conductive members forming two conductive lines, wherein the first connectors are the first connector. The second conductive members are electrically connected by the second conductive member, and the second connectors are electrically connected by the second conductive member.

The backlight unit further includes an insulating plate, and the first and second conductive members are plate members or foil members attached to the insulating plate.
The fluorescent lamp includes a first linear portion extending in parallel from a U-shaped bent portion and a second linear portion longer than the first linear portion, and each fluorescent lamp The lamps are arranged such that the linear portions are parallel and the bent portions are aligned on the same side, and the first and second conductive members extend in a direction intersecting the linear portions. It is provided.

Furthermore, an insulating sheet is provided between the first conductive member or the second conductive member and the glass bulb in a region where the first conductive member or the second conductive member crosses the glass bulb. It is characterized by being.
In order to achieve the above object, in a liquid crystal display device according to the present invention, the backlight unit includes an envelope that houses a plurality of the fluorescent lamps, a liquid crystal display panel, and the envelope And the backlight unit disposed on the back surface of the liquid crystal display panel.

  According to the backlight unit of the present invention, the first metal conductor is fitted to the first connector provided corresponding to each fluorescent lamp, and the second metal conductor is fitted to the second connector. As a result, since the fluorescent lamp is assembled, the same assembling man-hours can be realized. In addition, since the first connectors are electrically connected by the first conductive member and the second connectors are electrically connected by the second conductive member, the plurality of fluorescent lamps are connected in parallel. Will be connected. Further, since the corresponding connectors (the first connectors or the second connectors) are electrically connected by one conductive member, a plurality of corresponding connectors are provided as in the conventional case. Compared to the sequential connection with the lead wires, assembly man-hours can be reduced.

  According to the liquid crystal display device according to the present invention, since the backlight unit having the plurality of fluorescent lamps connected in parallel is provided, the luminance unevenness between the fluorescent lamps is small, and therefore, the image with little luminance unevenness on the liquid crystal display panel. Is formed. Further, for the same reason as described above, it is possible to reduce the number of assembling steps for the entire liquid crystal display device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a plan view showing a schematic configuration of a direct-type backlight unit 10 according to the embodiment, and FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG. 1 shows a state in which a translucent plate 22 to be described later and a mounting frame 24 to which the translucent plate 22 is attached are removed. Moreover, the scale between each structural member is not unified in all figures including FIG.

The backlight unit 10 is arranged and used on the back of an LCD (liquid crystal display) panel (not shown), and constitutes an LCD device serving as a display unit of a liquid crystal television.
The configuration of the backlight unit 10 will be described with reference to FIGS. 1 and 2.
The backlight unit 10 includes a U-shaped bent external electrode fluorescent lamp (EEFL) 14 (hereinafter simply referred to as a “fluorescent lamp 14”) in a flat box envelope 12. Is stored and configured. When the backlight unit 10 is used as a constituent unit such as a liquid crystal television, the X-axis direction shown in FIG. 1 is in a substantially horizontal direction and the Y-axis direction is in a substantially vertical direction.

  The envelope 12 basically includes a horizontally-long rectangular reflecting plate 18, a side plate 20 surrounding the reflecting plate 18, and a translucent plate 22 provided in parallel to the reflecting plate 18. The translucent plate 22 is fitted in an attachment frame 24 attached to the side plate 20. The mounting frame 24 is made of a non-translucent material, and light emitted from the fluorescent lamp 14 is extracted from a region surrounded by a two-dot chain line in FIG. 1 where only the translucent plate 22 exists.

The light transmission plate 22 is formed by laminating a light diffusion plate 26, a light diffusion sheet 28, and a lens sheet 30 in order from the reflection plate 18 side (fluorescent lamp 14 side).
Moreover, the reflecting plate 18 is stuck to the metal plate 32 for reinforcement.
Next, a schematic configuration of the fluorescent lamp 14 will be described.
The fluorescent lamp 14 is a dielectric barrier discharge fluorescent lamp in which external electrodes 36 and 38 are provided on the outer periphery of both end portions of a hermetically sealed glass bulb 34 and the glass tube wall is used as a capacitance.

  The external electrodes 36 and 38 are made by winding an aluminum foil, which is a metal conductor, around the outer periphery of the glass bulb 34. The metal conductor used as the external electrode is not limited to this, and may be composed of other metal foil, for example, copper foil. Alternatively, a metal foil film may be formed on the surface of the glass bulb by vapor deposition, or a conductive paste applied in a film shape may be baked, and this may be used as an external electrode.

A phosphor film 40 is formed on the inner peripheral surface of the glass bulb 34. The phosphor film 40 is formed between the external electrodes 36 and 38 excluding a range facing the external electrodes 36 and 38 at both ends in the tube axis direction of the glass bulb 34. The phosphor film 40 includes three kinds of rare earth phosphors of red (R), green (G), and blue (B), and emits white light as a whole.
Further, a mixed gas containing neon and argon and mercury are sealed in the glass bulb 34 as a discharge substance (discharge gas) (both not shown).

  The glass bulb 34 has a bent portion 42 bent in a U-shape, and first and second linear portions 44 and 46 extending in parallel from the bent portion 42. The second linear portion 46 is longer than the first linear portion 44 in accordance with the connector arrangement position described later. Here, when the external electrodes 36 and 38 are distinguished, the external electrode 36 made of the first metal conductor is referred to as the first external electrode and is provided in the second linear portion 46. The external electrode 38 made of the second metal conductor is referred to as a second external electrode. Note that the term “first external electrode” and “second external electrode” are only used to distinguish the external electrodes 36 and 38 with respect to the arrangement position. Basically, the external electrodes 36 and 38 are made of the same material. Formed of conductor. As shown in FIG. 1, each fluorescent lamp 14 is supported in the envelope 12 such that the bent portion 42 is aligned on the upper side and the first and second linear portions 44 and 46 are parallel to each other. ing.

Next, a support structure and the like of the fluorescent lamp 14 in the envelope 12 will be described with reference to FIG.
FIG. 3 is a perspective view illustrating the backlight unit 10 in a state in which a part of the side plate 20, the translucent plate 22, and the mounting frame 24 are removed.
As shown in FIG. 3, two elongated insulating plates (first and second insulating plates 48 and 50) are laid on the upper surface of the reflecting plate 18 substantially in parallel. The first and second insulating plates 48 and 50 are made of polycarbonate. In this example, two insulating plates are used, but a single insulating plate having the same size as the two combined may be used.

A first power supply member 52 for supplying power to the first external electrode 36 is provided on the upper surface of the first insulating plate 48, and a second power supply for supplying power to the second external electrode 38 is provided on the upper surface of the second insulating plate 50. A member 54 is provided.
Since the first power supply member 52 and the second power supply member 54 have substantially the same structure, the first power supply member 52 will be described in detail here as a representative.

  The first power supply member 52 is a first conductive member that physically connects and electrically connects the first connectors 56 to which the first external electrodes 36 are fitted. 1 plate 57. The first power supply member 52 is formed by pressing an elongated plate material (phosphor bronze plate) made of phosphor bronze. In the longitudinal direction of the plate material, cut into two continuous rectangular frames leaving one adjacent short side, and have a pair of sandwiching pieces 56a and 56b having arc portions as shown in FIG. Form. The first connector 56 is configured by the sandwiching pieces 56 a and 56 b and the plate member portion (connecting portion 56 c) that connects the sandwiching pieces 56 a and 56 b, and the first plate 57 is formed by the remaining plate member portion other than the first connector 56. Composed. When the first external electrode 36 is fitted to the first connector 56, both the sandwiching pieces 56a, 56b bend outward and hold the first external electrode 36 with its restoring force. The first plate 57 is attached to the upper surface of the first insulating plate 48.

Similarly, the second power supply member 54 includes a second connector 58 group in which each of the second external electrodes 38 is fitted, and a second conductive member that physically connects and electrically connects the second connectors 58. And the second plate 60.
The backlight unit 10 includes an inverter 62, and one end portions of two lead wires 68 and 70 from the inverter 62 are soldered to end portions of the first plate 57 and the second plate 60, respectively. The inverter 62 as a power supply circuit unit converts 50/60 Hz AC power from a commercial power supply (not shown) into high frequency power and supplies the fluorescent lamp 14 with power.

  A bent portion support member 80 made of PET resin is attached to the side wall 10 corresponding to each fluorescent lamp 14. As shown in FIG. 2, the bent portion support member 80 has a “C” -shaped cross section, and a glass bulb 34 (bent portion 42) having a circular cross section is fitted into the C-shaped cross section. At this time, the bent portion 42 is firmly supported by the elastic deformation of the C-shaped cross section.

In addition, an insulating sheet 82, which is an insulating member made of polycarbonate, is provided so as to cover the first plate 57 portion in a region where the second linear portion 46 of the glass bulb 34 and the first plate 57 intersect three-dimensionally. Yes. The reason for providing the insulating sheet 82 will be described later.
In the backlight unit 10 having the above-described configuration, the fluorescent lamp 14 can be easily assembled in the envelope 12 with a small number of man-hours in an assembly process at the time of manufacture. That is, after the bent portion 42 of the fluorescent lamp 14 is fitted into the bent portion support member 80, the fluorescent lamp 14 is rotated around the bent portion support member 80, and the first and second portions formed on the outer periphery of both ends of the glass bulb 34. The assembly is completed simply by fitting the second external electrodes 36 and 38 to the first connector 56 and the second connector 58, respectively.

  In addition, as shown in FIG. 1, the first connector 56 and the second connector 58 are arranged in two upper and lower rows, and the first connector 56 and the second connector 58 are respectively connected to the first and second connectors of the glass bulb 34. Since it is extended in the direction (orthogonal direction) intersecting the two linear portions 44, 46, and is electrically connected by the first plate 57 and the second plate 60 that form two conductive lines, By supplying power via the first and second plates 58 and 60, the plurality of fluorescent lamps 14 can be turned on in parallel by a single inverter 62.

In this case, the second linear portion 46 of the glass bulb 34 is three-dimensionally crossed with the first plate 57 electrically connected to the first external electrode 36 at a portion close to the second external electrode 38. The potential difference between the intersecting portions of the linear portion 46 and the first plate 57 is large. Therefore, if nothing is provided between the two intersecting portions, a leakage current flows from the higher potential of the intersecting portion to the lower potential, which causes a situation in which the luminance of the fluorescent lamp 14 decreases. Therefore, in order to suppress the leakage current as much as possible, the insulating sheet 82 is disposed between the intersecting portions.
(Embodiment 2)
In the first embodiment, since a plurality of fluorescent lamps are connected in parallel, the fluorescent lamp 14 includes two linear portions 44 and 46 in accordance with the first and second connectors 56 and 58 arranged in two rows. Although the fluorescent lamps 14 having different lengths are employed, in the second embodiment, even a general fluorescent lamp in which both linear portions have the same length can be connected in parallel. .

For this reason, the backlight unit of the second embodiment has basically the same configuration as the backlight unit 10 of the first embodiment, except that the fluorescent lamp and the power feeding member are mainly different. Therefore, common parts are denoted by the same reference numerals, and the description thereof is omitted or simply mentioned, and different parts will be mainly described.
4 is a view showing a part of the backlight unit 90 according to the second embodiment, and is a perspective view showing a state in which a part of the side plate 20 and the translucent plate are removed, and corresponds to FIG. FIG.

  As described above, in the external electrode fluorescent lamp 92 used in the backlight unit 90, the lengths of the first and second linear portions 96 and 98 extending in parallel from the bent portion 94 are substantially equal. Also, provided on the outer periphery of the first linear portion 96 end, provided on the outer periphery of the first connector 56 to which the first external electrode 100 made of the first metal conductor is fitted, and on the outer periphery of the second linear portion 98, The second connectors 58 into which the second external electrodes 102 made of the second metal conductor are fitted are alternately arranged in a row in the horizontal direction (X-axis direction).

  A first plate 104, which is a first conductive member that physically connects and electrically connects the first connectors 56, includes a belt-like portion 104a extending in the horizontal direction (X-axis direction) and the belt-like portion 104a. The bridge portion 104b extends in the vertical direction (Y-axis direction) in accordance with the direction and the arrangement interval of the first connectors 56. The first power supply member 106 including the first connector 56 and the first plate 104 is integrally formed from a single metal plate by pressing.

  Further, the second power supply member 108 has the same configuration as the first power supply member 106. That is, the second plate 110, which is a second conductive member that physically connects and electrically connects the second connectors 58, includes a strip 110a extending in the horizontal direction (X-axis direction) and the strip 110a. The bridge portion 110b extends in the vertical direction (Y-axis direction) in accordance with the horizontal direction and the arrangement interval of the second connectors 58. The second power supply member 108 is integrally formed from a single metal plate by pressing.

In the second embodiment, a single insulating plate 112 is laid on the upper surface of the reflecting plate 18, and the first and second power feeding members 106 and 108 are installed thereon. That is, the first plate 104 and the second plate 110 that form two conductive lines are attached to the upper surface of the insulating plate 112.
(Embodiment 3)
In the first and second embodiments, an external electrode fluorescent lamp (EEFL) using dielectric barrier discharge is used as the light source of the backlight unit. In the third embodiment, a cold cathode fluorescent lamp (CCFL) is used. Used.

FIG. 5 is a longitudinal sectional view of one end portion of a cold cathode fluorescent lamp 120 (hereinafter simply referred to as “fluorescent lamp 120”) used in the third embodiment. Since the other end portion has the same structure, its illustration and description are omitted.
The fluorescent lamp 120 has a glass bulb 124 in which the end of a glass tube having a circular cross section is hermetically sealed with a lead wire 122. The glass bulb 124 is made of hard borosilicate glass.

Inside the glass bulb 124, an appropriate amount of mercury (not shown) and a mixed gas (not shown) composed of plural kinds of rare gases such as argon (Ar) gas and neon (Ne) gas are sealed.
Each of the lead wires 122 is a connection between an internal lead wire 122A made of tungsten and an external lead wire 122B made of nickel. The glass tube is hermetically sealed at the internal lead wire 122A.

An internal electrode 126 is joined to the inner end portion of the internal lead wire 122A supported on the end portion of the glass bulb 124 by laser welding or the like. The internal electrode 126 is a so-called hollow electrode having a bottomed cylindrical shape, and is obtained by processing a niobium rod.
A phosphor film 128 is formed on the inner peripheral surface of the glass bulb 124. The phosphor film 128 includes three kinds of rare earth phosphors of red (R), green (G), and blue (B), and emits white light as a whole.

  The above is the basic configuration of the cold cathode fluorescent lamp. In the fluorescent lamp 120, in order to easily fit the first and second connectors 56, 58, the outer periphery of the end portion of the glass bulb 124 is shown in FIG. The metal sleeve 130 which is a metal conductor as shown in FIG. The metal sleeve 130 is made of a material having substantially the same linear expansion coefficient as that of the glass bulb 124, for example, an Fe—Ni—Co alloy. Then, as shown in FIG. 5, the end portion of the metal sleeve 130 is filled with solder 132 to electrically connect the metal sleeve 130 and the external lead wire 122B, and the metal sleeve 130 is configured as the external electrode 130. is doing.

The backlight unit according to Embodiment 3 has basically the same configuration as the backlight unit 10 of Embodiment 1 except that the fluorescent lamp 120 and the power supply member are mainly different. Therefore, common parts are denoted by the same reference numerals, and the description thereof is omitted or simply mentioned, and different parts will be mainly described.
FIG. 7 is a view showing a part of the backlight unit 134 according to Embodiment 3, and is a perspective view showing a state in which a part of the side plate 20 and the translucent plate are removed, and corresponds to FIG. FIG.

  As in the fluorescent lamp 14 of the first embodiment, the overall shape of the fluorescent lamp 120 is a U-shaped bent portion 136 and a first straight line extending in parallel from the bent portion 136. This is a bent fluorescent lamp having a shape portion 138 and a second straight portion 140 longer than the first straight portion 138. A first external electrode 130a made of a first metal conductor (metal sleeve) is provided at the end of the first linear portion 138, and a second metal conductor (metal sleeve) is provided at the end of the second linear portion 140. ) Second external electrode 130b.

Also, the first power supply member 142 for electrically connecting the first external electrodes 130a and the second power supply member 144 for electrically connecting the second external electrodes 130b are laid on the reflector 18. It is installed on the upper surface of the insulating plate 146.
Since the first power supply member 142 and the second power supply member 144 have substantially the same structure, the details of the first power supply member 142 will be described here as a representative.

The first connector 148 constituting the first power supply member 142 has a structure in which the rectangular plate portion 148b is integrally connected to the first connector 56 (FIG. 3) of the first embodiment. The first connector 148 having the rectangular plate portion 148b is integrally formed from a single metal plate by pressing.
In addition, the first power supply member 142 includes an elongated first printed circuit board 150 that extends in the horizontal direction (X-axis direction). The printed circuit board 150 includes an insulating plate 150a and a wiring pattern 150b that is a first conductive member. The wiring pattern 150b is made of copper foil. Needless to say, the wiring pattern 150b (copper foil) is affixed to the insulating plate 150a.

A surface mount type capacitor 152 is mounted so as to bridge the rectangular plate portion 148b of each first connector 148 and the wiring pattern 150b. The capacitor 152 is provided as a ballast capacitor in order to turn on the fluorescent lamp 120, which is a cold cathode fluorescent lamp, in parallel by a single inverter 62 (FIG. 3).
With the above configuration, all the first connectors 148 are conductive members for electrically connecting the first connectors 148 to each other, and are connected by the wiring pattern 150b forming the conductive lines.

  Similarly, the second power supply member 144 is a conductive member for electrically connecting the second connector 154 to the second connector 154 group to which each of the second external electrodes 130b is fitted, and the conductive line is connected to the second power supply member 144. And a second printed circuit board 156 having a wiring pattern 156b to be formed. Similar to the first printed circuit board 150, the second printed circuit board 156 includes an insulating plate 156a and the wiring pattern 156b, which is a second conductive member made of a copper foil attached to the insulating plate 156a.

According to the backlight unit 134 having the above configuration, the fluorescent lamp 120 is a cold cathode fluorescent lamp, but can be easily assembled to the envelope (attached to the first and second connectors 148 and 154). In addition, the fluorescent lamps 120 can be lit in parallel.
Next, an example in which the backlight unit according to the above embodiment is used in a liquid crystal television which is an example of a liquid crystal display device will be described. Any of the backlight units of the first to third embodiments may be used, but here, the backlight unit 10 according to the first embodiment (FIGS. 1 to 3) is used as a representative.

FIG. 9 is a view showing the liquid crystal television 170 in a state in which a part of the front surface is cut away. A liquid crystal television 170 shown in FIG. 9 is, for example, a 32-inch size liquid crystal television, and includes a liquid crystal display panel 172, a backlight unit 10, and the like.
The liquid crystal display panel 172 includes a color filter substrate, a liquid crystal, a TFT substrate, and the like, and is driven by a drive module (not shown) based on an external image signal to form a color image.

The envelope 12 of the backlight unit 10 is provided on the back surface of the liquid crystal display panel 172, and irradiates the liquid crystal display panel 172 from the back surface.
The inverter 62 is disposed inside the casing 174 of the liquid crystal television 170 and outside the envelope 12.
As mentioned above, although this invention has been demonstrated based on embodiment, this invention is not restricted to an above-described form, Of course, it can also be set as the following forms, for example.
(1) In the first to third embodiments, the fluorescent lamp is arranged in a so-called vertical orientation in which the longitudinal direction is the vertical direction (Y-axis direction). The backlight unit may be configured by being arranged horizontally so as to be in the (X-axis direction).
(2) In the first and third embodiments, since the first connector and the second connector are arranged in two upper and lower rows, the lower limit of the light extraction area indicated by the two-dot chain line in FIG. 1 is higher than the first connector 56 rows. I had to be. Therefore, as shown in FIG. 8, in the fluorescent lamp 160, the lower limit of the light extraction region indicated by the two-dot chain line is set to the first connector 56 row by folding back (bending) the first linear portion 162 further upward. It does not matter even if it extends between the second connector 58 rows. In FIG. 8, reference numeral 164 indicates the arrangement position of the first connector 56 row in the vertical direction (Y-axis direction), and reference numeral 166 indicates the arrangement position of the second connector row 58 in the vertical direction (Y-axis direction). ing.

  The backlight unit according to the present invention can be used, for example, for a liquid crystal display device.

It is the top view which represented the backlight unit which concerns on Embodiment 1 in the state except the translucent board and its attachment frame. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. It is the perspective view which represented the backlight unit which concerns on Embodiment 1 in the state except a part of side plate, the translucent board, and the attachment frame. It is the perspective view showing the backlight unit which concerns on Embodiment 2 in the state except a part of side plate, the translucent board, and the attachment frame. 6 is a longitudinal sectional view of an end portion of a cold cathode fluorescent lamp used as a light source of a backlight unit according to Embodiment 3. FIG. It is a perspective view of the metal sleeve attached to the said cold cathode fluorescent lamp. It is the perspective view which represented the backlight unit which concerns on Embodiment 3 in the state except a part of side plate, the translucent board, and the attachment frame. It is a figure which shows schematic structure of the backlight unit which concerns on a modification, Comprising: It is the top view represented in the state except the translucent board and its attachment frame. It is a figure which shows schematic structure of the liquid crystal television using the backlight unit which concerns on the said embodiment. It is a figure which shows the backlight unit which concerns on a prior art.

Explanation of symbols

10, 90, 134 Backlight unit 14, 92 External electrode type fluorescent lamp 34, 124 Glass bulb 36, 100 First external electrode 38, 102 Second external electrode 56, 148 First connector 57, 104 First plate 58, 154 Second connector 60, 110 Second plate 82 Insulation sheet 120 Cold cathode fluorescent lamp 150b, 156b Wiring pattern

Claims (4)

A plurality of fluorescent lamps in which a first metal conductor is formed on the outer periphery of the first end of the U-shaped bent glass bulb and a second metal conductor is formed on the outer periphery of the second end are arranged. A backlight unit,
A first connector on which a first metal conductor is fitted, a second connector on which a second metal conductor is fitted, provided corresponding to each fluorescent lamp;
Having first and second conductive members forming two conductive lines;
The first connectors are electrically connected to each other by the first conductive member, and the second connectors are electrically connected to each other by the second conductive member ;
An insulating sheet is provided between the first conductive member or the second conductive member and the glass bulb in a region where the first conductive member or the second conductive member crosses the glass bulb. A backlight unit characterized by The backlight unit further includes:
Having an insulating plate,
The backlight unit according to claim 1, wherein the first and second conductive members are a plate or a foil attached to the insulating plate. The fluorescent lamp has a first linear portion extending in parallel from a U-shaped bent portion and a second linear portion longer than the first linear portion, and the fluorescent lamps are connected to each other. Is arranged such that the linear portions are parallel and the bent portions are aligned on the same side,
The backlight unit according to claim 1, wherein the first and second conductive members are extended in a direction intersecting with the linear portion. The backlight unit has an envelope that houses a plurality of the fluorescent lamps,
A liquid crystal display panel;
The backlight unit according to any one of claims 1 to 3 , wherein the envelope is disposed on a back surface of the liquid crystal display panel.
A liquid crystal display device comprising:

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