JP3434053B2 - Backlight and liquid crystal display device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side-light type backlight, in which light emitted from an L-shaped lamp is reflected by a gutter-shaped reflector to be guided to a light guide plate and emitted from the surface of the light guide plate. The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art In a liquid crystal display device, a backlight is usually installed on the back surface of the liquid crystal display panel, and the back surface of the liquid crystal display panel is illuminated by the light emitted from the backlight.

In the case of a small-sized liquid crystal display device, an illumination device called a side (edge) light system is used as the backlight. This type of sidelight type backlight is provided with a rod-shaped lamp, for example, a cold cathode fluorescent lamp on the side surface of a transparent or milky white light-transmitting square-shaped light guide plate such as acrylic resin, and this lamp is used as a reflector. It is configured to cover.

When such a cold cathode fluorescent lamp is lit, a part of the light emitted from this lamp is reflected by the reflector and goes to the side surface of the light guide plate, and the rest goes directly to the side surface of the light guide plate. Therefore, the light guide plate introduces light from its side surface, and this incident light is repeatedly reflected in the light guide plate and tends to be emitted to the outside from the front surface, the back surface, and the side surface.
In this case, if a reflecting surface is provided on the back surface or the side surface, the light that is about to be emitted from the back surface or the side surface will be reflected by these reflecting surfaces, so that this reflected light is returned to the light guide plate again, Finally, most of the light is emitted from the surface (light emitting surface) of the light guide plate.

Then, the light emitted from the light emitting surface of the light guide plate is diffused by the light diffusing member and controlled so as to have a substantially uniform luminance distribution over the entire surface. Irradiate the back of the display panel. Therefore, such an illuminating device can be used as a backlight of a liquid crystal display panel.

In such a liquid crystal display device, the higher the brightness of the light guide plate, the higher the brightness of the liquid crystal display panel and the better the visibility. Therefore, as the light source of the backlight,
A rod-shaped lamp, for example, a cold cathode fluorescent lamp, which is small in size, excellent in light emission efficiency, and suitable for illuminating the narrow side of the light guide plate is used.

Further, such a rod-shaped lamp is covered with a reflector having a substantially gutter shape as a whole, and the light emitted from the lamp is directed to the side surface of the light guide plate by the reflector.

By the way, the light guide plate is often formed as a rectangular flat plate corresponding to the shape of the screen of the liquid crystal display panel. If a rod-shaped lamp is installed on only one side of such a light guide plate, the amount of light may be small and sufficient brightness may not be obtained. To prevent this, JP-A-5-23
As described in Japanese Patent No. 2468, it is considered to dispose a single L-shaped lamp across two adjacent sides of the light guide plate.

If an L-shaped lamp is arranged over two adjacent sides of the light guide plate, light is introduced from two adjacent sides of the light guide plate even if one lamp is turned on.
Therefore, there are advantages that the lighting device is simple, the amount of light is increased, and the variation in brightness on the surface of the light guide plate is reduced.

[0010]

However, when manufacturing an L-shaped lamp, a means for heating and softening one long glass tube and bending it is adopted. Although the accurate bending angle is 90 °, the actual bending angle of the lamp has an error of 90 ± α ° due to variations in the bending process. When installing an L-shaped lamp with such variations in a reflector, the bending angle is forced to 90 °.
If the lamp is pressed firmly to keep it at that position, the bent portion may be distorted and may be broken. For this reason, a lamp having a bending angle variation of ± α ° needs to be attached to the reflector while keeping the variation. For this reason, the reflector may have a margin to accommodate the lamp having the above variation. Will be needed.

That is, it is desirable that the reflector having a substantially U-shaped cross section has a depth such that the variation of the lamp can be absorbed.

However, when the depths for absorbing the variations of the lamp are set in the reflectors on the long side and the short side, respectively, the reflector becomes large and the entire backlight becomes large.

When the bending angle varies,
When the bending portion is taken as the center, the displacement amount of the long side end is larger than the displacement amount of the short side end. Therefore, when trying to absorb the variation of the lamp on the long side of the reflector, the displacement amount is large, and therefore the depth of the reflector must be increased. In this case, the reflector becomes large and the backlight becomes large. There is a problem that the whole becomes large.

Therefore, an object of the present invention is to arrange a lamp bent in an L-shape along two adjacent sides of a light guide plate and absorb a variation in the bending angle of the L-shape lamp to form a reflector. When covered with, the reflector does not become large,
An object of the present invention is to provide a backlight capable of preventing the overall size increase and a liquid crystal display device using the same.

[0015]

According to a first aspect of the present invention, there is provided a light-transmitting light guide plate having a square shape having long sides and short sides and an end face of the long side and the short side adjacent to the light guide plate. An L-shaped lamp provided opposite to each other and having straight portions having different lengths, and an L-shaped lamp which covers the L-shaped lamp and reflects light emitted from the lamp toward the light guide plate. In the backlight including the reflector having the above-mentioned feature, the depth of the reflector is set such that the depth of the short-side reflector is larger than the depth of the long-side reflector.

According to a second aspect of the present invention, the reflector has a structure in which the long side reflector and the short side reflector are separate structures.

According to a third aspect of the present invention, the L-shaped lamp is
At least both ends and the bent portion are supported by the lamp holder, and the lamp holder is attached to the reflector so as to be movable in the depth direction.

According to a fourth aspect of the present invention, the lamp holder is made of an elastically deformable rubber material, and the lamp holder is press-fitted into the reflector so as to be movable in the depth direction. According to a fifth aspect of the invention, there is provided a lighting circuit for lighting the L-shaped lamp.

According to a sixth aspect of the present invention, there is provided a backlight according to any one of the first to fifth aspects, and a liquid crystal display panel that receives light emitted from the backlight on its back surface. Is a liquid crystal display device.

[0020]

According to the first aspect of the present invention, since the depth of the reflector on the short side is larger than the depth of the reflector on the long side, the reflector is an L-shaped lamp having a variation in bending angle. Even if it is housed, the short side reflector can absorb the displaced portion due to the above variation. In this case, in the L-shaped lamp, the displacement amount due to the variation of the bending angle is smaller in the short side linear portion than in the long side linear portion, so that the depth of the short side reflector can be minimized. Therefore, the amount of protrusion of the reflector from the light guide plate can be reduced, and the reflector and the entire backlight can be downsized.

According to the second aspect of the invention, since the long-side reflector and the short-side reflector have separate structures, the reflectors having different depths can be formed separately, which facilitates manufacturing. Is.

According to the invention of claim 3, at least both ends and the bent portion of the L-shaped lamp are supported by the lamp holder, so that the L-shaped lamp is surely supported, and these lamp holders have the above reflection. L is attached to the body so that the position can be adjusted in the depth direction.
Even if the bending angle of the letter-shaped lamp varies, it can be absorbed by the short-side reflector having a large depth.

According to the invention of claim 4, since the lamp holder is made of an elastically deformable rubber material, it is possible to absorb shock and vibration, and these lamp holders are elastically deformed with respect to the reflector. Is pressed in,
It can be moved in the depth direction and has good workability in mounting.

According to the invention of claim 5, since the lighting circuit for lighting the L-shaped lamp is provided, the backlight can be unitized without requiring a special lighting circuit outside.

Since the invention of claim 6 is a liquid crystal display device in which the backlight according to any one of claims 1 to 5 is attached to the back surface of a liquid crystal display panel, the liquid crystal display device can be made compact and compact. Becomes possible.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings.

FIG. 2 is a plan view of a sidelight type backlight, FIG. 3 is an exploded perspective view thereof, FIG. 4 is an exploded perspective view of a liquid crystal display device using the above backlight, and FIG. It is sectional drawing of an assembly state.

First, the backlight 1 will be described. The backlight 1 is composed of a light guide plate 2, a cold cathode fluorescent lamp 3 as a rod-shaped L-shaped lamp, and a reflector 4 covering the lamp 3. The lamp 3 is lit by the lighting circuit 5.

The light guide plate 2 is made of a transparent or milky white light transmissive material such as acrylic resin, and has a rectangular flat plate shape having two opposing long sides and two opposing short sides. .

On the adjacent side of the light guide plate 2, the above L
A letter-shaped cold cathode fluorescent lamp 3 is arranged. The cold cathode fluorescent lamp 3 has, for example, a bulb 30 in which a soft glass tube having an outer diameter of 4 mm is bent into an L shape.
The straight line portion 31 along the long side of the light guide plate 2 and the straight line portion 32 along the short side of the light guide plate 2 are continuously arranged at a bending angle of 90 °. In this case, the linear portion 31 along the long side of the light guide plate 2 is formed to be longer than the linear portion 32 along the short side of the light guide plate 2.

At both ends of the bulb 30, cold cathodes 33, 33 made of nickel or the like are sealed, and a phosphor coating (not shown) is formed on the inner surface. Further, a rare gas such as mercury and argon is enclosed in the bulb 30.

The cold cathode fluorescent lamp 3 as described above is arranged so as to face the end faces of the adjacent side edges of the light guide plate 2, and when the bending angle is accurately set to 90 °, the straight line portion is formed. 31 and 32 are arranged so as to be substantially parallel to the sides of the light guide plate 2.

The cold cathode fluorescent lamp 3 as described above is covered with the reflector 4. The reflector 4 is L throughout
It is not impossible to integrally form a letter shape, but in the case of the present embodiment, the long side reflector 41 along the long side of the light guide plate 2,
It is composed of a short side reflector 42 along the short side of the light guide plate 2, and the long side reflector 41 and the short side reflector 42 are connected by a corner portion of the light guide plate 2. ing. The long side reflector 41 and the short side reflector 42 are made of synthetic resin,
Although it can be formed of glass or the like, in the case of the present embodiment, it is formed by pressing with a metal plate, for example, an aluminum plate. These reflectors 4
Reference numerals 1 and 42 are formed in a substantially gutter shape, that is, a U-shaped cross section so as to cover the cold cathode fluorescent lamp 3. More specifically, flat portions 43 are formed on the upper and lower surfaces.
In addition to having 44, a curved surface portion 45 is formed in the back of these flat portions 43, 44 and is continuous with these flat portions 43, 44.

In this case, as shown in FIG. 1, the depth L ₄₁ of the long side reflector ₄₁ is smaller than the depth L ₄₂ of the short side reflector 42 (L ₄₁ <L ₄₂ ). There is. Here, the depth of the reflector 41 is, as can be understood from FIG. 1, from the end surface of the light guide plate 2 to the inner surface of the tip end of the curved surface portion 45 of the reflector 41.

The depth L ₄₁ of the long side reflector ₄₁ is smaller than the depth L ₄₂ of the short side reflector 42 (L ₄₁ <
L ₄₂ ) means that the depth of the flat portions 43 and 44 of the long-side reflector 41 is substantially equal to that of the short-side reflector 4.
This means that it is formed smaller than the depth of the second flat portions 43 and 44.

Reflecting surfaces 4 for reflecting the light emitted from the fluorescent lamp 3 and directing the light emitted from the fluorescent lamps 3 toward the end surfaces of the light guide plate 2 are provided on the inner surfaces of the long-side reflector 41 and the short-side reflector 42, respectively.
6, 46 are formed.

The L-shaped cold cathode fluorescent lamp 3 is attached to such a reflector 4 via a lamp holder 6. The lamp holder 6 has the shape shown in FIG. 6A, and is made of a rubber elastic member such as silicon rubber. This lamp holder 6
Has a U shape similar to the inner surface shape of the reflector 4, and in this case, the height of the lamp holder 6 is slightly larger than the distance between the flat portions 43 and 44 of the reflector 4. Therefore, the lamp holder 6 is press-fitted into the reflector 4 and elastically deforms to frictionally engage with the reflector 4. Further, the depth of the lamp holder 6 is approximately the same as the depth of the long side reflector 41. When this is fitted into the short side reflector 42, the short side reflector is Since the depth of 42 is large, the short side reflector 42 can slide in the depth direction.

A lamp insertion hole 61 is formed in the lamp holder 6, and the lamp insertion hole 61 has an inner diameter slightly smaller than the outer diameter of the bulb 30. When the lamp 3 is inserted into the lamp insertion hole 61, the lamp holder 6 elastically deforms and elastically holds the lamp 3.

Such a lamp holder 6 is attached to at least three places of the both ends and the bent portion of the L-shaped lamp 3, and these lamp holders 6 ... It is fitted into the short-side reflector 42. In this case, the lamp holders 6 ... Deform elastically and engage with the long-side reflectors 41 and the short-side reflectors 42, thereby causing the lamp 3 to pass through the lamp holders 6 ... It is housed in the short-side reflector 42 and mechanically supported.

The lamp holders include lamp holders 6a and 6b having shapes other than the shape shown in FIG. 6A and shown in FIGS. 6B and 6C. The lamp holder 6 having another shape shown in FIG.
a is a slit 62 that communicates the lamp insertion hole 61 with the outside.
By this, the lamp holder 6a can be easily elastically deformed, and the lamp 3 can be guided to the lamp insertion hole 61 through the slit 62.
In addition, a lamp holder 6 having another shape shown in FIG.
b has a circular outer shape and is easy to manufacture.

A concave groove 48 is formed along the longitudinal direction on the lower surface of each of the long-side reflector 41 and the short-side reflector 42, for example, on the lower flat portion 44 described above. The heater 7 is arranged in the groove 48. The heater 7 may be a conductive paste, a conductive paint, or the like, but in this example, a metal heater made of a metal band is used, and the metal heater 7 is used for the lamp 3 as shown in FIG. The recessed groove 48 is formed in an L shape conforming to the shape.
It is housed in.

In this case, the upper surface of the metal heater 7 does not protrude above the upper surface of the lower flat portion 44, and when the metal heater 7 protrudes above the upper surface of the lower flat portion 44. , It interferes with the insertion of the lamp holder 6 ...

The above-mentioned reflectors 41 and 42 are fixed to the light guide plate 2 by bonding the respective flat portions 43 and 44 to the upper and lower surfaces of the light guide plate 2 with an adhesive or the like.

A reflection sheet 8 is provided on the lower surface (back surface) of the light guide plate 2.
The reflection sheet 8 reflects the light introduced into the light guide plate 2 and directs it toward the upper surface (surface = light emitting surface) side. The remaining side of the light guide plate 2 where the lamp 3 is not provided is also provided with a reflection sheet (not shown) or other reflection surface treatment.

On the upper surface of the light guide plate 2, there is provided a milky white light diffusion sheet 9 made of acrylic resin or the like. The light diffusion sheet 9 diffuses the light emitted from the upper surface of the light guide plate 2. Control to obtain a uniform brightness distribution,
This eliminates uneven brightness.
The backlight 1 is formed by such a structure.

The high frequency lighting circuit 5 is arranged near the light guide plate 2, and the lamp 3 is connected to a power source (not shown) through the high frequency lighting circuit 5. The high frequency lighting circuit 5 is arranged to face the other side of the light guide plate 2 where the L-shaped lamp 3 is not arranged.

According to such a backlight 1, when the cold cathode fluorescent lamp 3 is lit at high frequency, the fluorescent lamp 3
The light emitted from the direct and the reflecting surfaces 4 of the reflectors 41, 42.
The light is reflected by 6, 46, faces the end face of the light guide plate 2, and enters the inside of the light guide plate 2 from this end face. The light introduced into the light guide plate 2 advances while being repeatedly reflected by the reflection sheet 8 provided on the front surface or the back surface of the light guide plate 2, and finally emitted toward the front surface of the light guide plate 2.

A liquid crystal display panel 10 is installed above the backlight 1, that is, above the light diffusion sheet 9, as shown in FIGS. 4 and 5. The liquid crystal display panel 10 receives light emitted from the light guide plate 2 from the back side. The backlight 1 and the liquid crystal display panel 10 thus configured constitute a liquid crystal display device.

In the case of such a configuration, since one L-shaped lamp 3 illuminates two adjacent sides of the light guide plate 2 at the same time,
The number of lamps is small and the amount of light can be increased. Therefore, the structure of the lighting circuit and the like becomes simple.

By the way, since the L-shaped lamp 3 is manufactured by heating and softening one long glass tube and bending the glass tube, variations occur in the bending process, and the bending angle of the lamp is 90 ± α °. It causes an error. When the L-shaped lamp 3 having the variation of the bending angle of ± α ° is accommodated and mounted in the reflector 4, it is necessary that the reflector 4 has a margin to accommodate the lamp having the above variation.

In this embodiment, the depth L of the long side reflector 41 is L.
Increasing the depth L ₄₂ of the short side reflector 42 as compared with ₄₁ (L ₄₁
Since <L ₄₂ ), the short-side reflector 42 can accommodate the error due to the variation in the bending angle.

That is, when an error occurs in the bending angle of the L-shaped lamp 3, as shown in FIG. 3, the displacement amount γ of the longer straight portion 31 corresponding to the long side with respect to the bending variation angle α. ₁ becomes larger than the displacement amount γ ₂ of the shorter straight portion 32 corresponding to the short side. Therefore, the L-shaped lamp 3
The linear portion 31 along the long side of the lamp is attached to the long side reflector 41 via the lamp holders 6, 6, and in this case, the lamp 3
The straight line portion 31 is straightly arranged at the regular attachment position with respect to the long side reflector 41.

In this way, the other straight portion 32 of the L-shaped lamp 3 is displaced from the regular mounting position with respect to the short-side reflector 42, is not arranged straight, and has a displacement amount γ ₂ . However, since the depth L ₄₂ of the short-side reflector 42 is larger than the depth L ₄₁ of the long-side reflector 41 (L ₄₁ <L ₄₂ ), the other straight portion of the L-shaped lamp 3 is Even if the displacement amount 32 has a displacement amount γ _2, it can be accommodated.

This is because the lamp holder 6 has the reflector 4 on the short side.
It becomes possible by sliding in the inside of 2 in the depth direction.

Therefore, even if the bending angle of the L-shaped lamp 3 varies slightly, the L-shaped lamp 3 can be accommodated in the reflector 4, and the depth L ₄₂ of the short-side reflector 42 can be reduced. Since it is larger than the depth L ₄₁ of the long-side reflector 41 (L ₄₁ <L ₄₂ ), the protruding amount of the short-side reflector 42 can be reduced.

On the contrary, the depth L ₄₁ of the long side reflector ₄₁ is made larger than the depth L ₄₂ of the short side reflector 42 so that the long side reflector 41 absorbs the displacement of the linear portion 31. If this is attempted, the amount of displacement γ _{1 of the} longer straight portion 31 is large, so the amount of protrusion of the long-side reflector 41 is large.

Therefore, with the structure of the above-described embodiment, the protruding amount of the short-side reflector 42 can be reduced, and the protruding amount of the entire reflector 4 can also be reduced. Therefore, the backlight 1 and the entire liquid crystal display device are small,
It can be made compact.

In the above embodiment, the long side reflector 41 is used.
Since the short-side reflector 42 has a separate structure, the reflectors 41 and 42 having different depths can be separately formed, which facilitates manufacturing.

Further, since the L-shaped lamp 3 is supported by the lamp holders 6 ... At least at both ends and the bent portion, the L-shaped lamp 3 is reliably supported. Since these lamp holders 6 are attached to the reflectors 41, 42 so as to be positionally adjustable in the depth direction, as described above, even if the bending angle varies, the short side with a large depth The lamp holder 6 housed in the reflector 42 can be absorbed by moving in the short side reflector 42.

Since the lamp holders 6 ... Are made of an elastically deformable rubber material, they can absorb impacts and vibrations, prevent damage to the lamps 3, and these lamp holders 6 ... Since they are elastically deformed and press-fitted into 41 and 42, they can be moved in the depth direction, and because they are frictionally engaged with the reflectors 41 and 42, the mounting work is easy.

The backlight 1 of the above-described embodiment is provided with the heater 7
Therefore, when the heater 7 is energized during low temperature starting, the heater 7 generates heat, and this heat is directly radiated to the valve 30 through the valve 30 or the reflectors 41 and 42, thereby increasing the temperature of the valve 30. become. For this reason, the startability at the time of low temperature starting is improved, the rising of the luminous flux is made quicker, and the brightness is also improved.

Further, the backlight 1 of the above embodiment is
Since the lighting circuit 5 for lighting the L-shaped lamp 3 is provided, the backlight 1 can be unitized without requiring a special lighting circuit outside. In this case, since the lighting circuit 5 is arranged so as to face the other side of the light guide plate 2 where the L-shaped lamp 3 is not arranged, the dead space can be effectively used, which is advantageous for downsizing. Becomes

In the above embodiment, one L-shape 3 is used, but two L-shape lamps may surround four sides of the light guide plate.

The rod-shaped lamp is not limited to a cold cathode fluorescent lamp, and may be a hot cathode fluorescent lamp. Further, the rod lamp is not limited to a lamp in which mercury is sealed, but a rare gas discharge lamp in which a rare gas such as xenon is sealed is used. It can be implemented even when used.

[0065]

As described above, according to the invention of claim 1, since the depth of the short-side reflector is larger than that of the long-side reflector, the bending angle varies. Even if an L-shaped lamp having a certain shape is accommodated, the short side reflector can absorb the displacement portion due to the above variation. In this case, in the L-shaped lamp, the displacement amount due to the variation of the bending angle is smaller in the short side linear portion than in the long side linear portion, so that the depth of the short side reflector can be minimized. Therefore, the amount of protrusion of the reflector from the light guide plate can be reduced, and the reflector and the entire backlight can be downsized.

According to the second aspect of the present invention, since the long side reflector and the short side reflector have separate structures, the reflectors having different depths can be formed separately, which facilitates manufacturing. Is.

According to the third aspect of the present invention, the L-shaped lamp has at least both ends and the bent portion supported by the lamp holder, so that the L-shaped lamp is reliably supported and the lamp holder has the above-mentioned reflection. L is attached to the body so that the position can be adjusted in the depth direction.
Even if the bending angle of the letter-shaped lamp varies, it can be absorbed by the short-side reflector having a large depth.

According to the invention of claim 4, since the lamp holder is made of an elastically deformable rubber material, it is possible to absorb shock and vibration, and these lamp holders are elastically deformed with respect to the reflector. Is pressed in,
It can be moved in the depth direction and has good workability in mounting.

According to the invention of claim 5, since the lighting circuit for lighting the L-shaped lamp is provided, the backlight can be unitized without requiring a special lighting circuit outside.

Since the invention of claim 6 is a liquid crystal display device in which the backlight according to any one of claims 1 to 5 is attached to the back surface of a liquid crystal display panel, the liquid crystal display device can be made compact and compact. Becomes possible.

[Brief description of drawings]

FIG. 1 shows a cross-sectional shape of a reflector according to an embodiment of the present invention,
2A is a cross-sectional view of the long side reflector along the line AA in FIG. 2, and FIG. 4B is a cross-sectional view of the short side reflector along the line BB in FIG.

FIG. 2 is a plan view showing a backlight of the same embodiment.

FIG. 3 is an exploded plan view of the backlight.

FIG. 4 is an exploded perspective view showing an entire liquid crystal display device using the backlight.

FIG. 5 is a cross-sectional view of the liquid crystal display device.

FIG. 6 shows a lamp holder, and FIGS. 6A, 6B, and 6C are perspective views of the lamp holder of different embodiments.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Backlight 2 ... Light guide plate 3 ... Cold cathode L-shaped fluorescent lamp 4 ... Reflector 5 ... Lighting circuit 6 ... Lamp holder 7 ... Heater 8 ... Light reflection sheet 9 ... Light diffusion sheet 10 ... Liquid crystal display panel 30 ... Bulb 31 , 32 ... Straight part 41 ... Long-side reflector 42 ... Short-side reflector 46 ... Reflective surface

Continuation of front page (56) Reference JP-A-7-333609 (JP, A) JP-A-5-232468 (JP, A) JP-A-4-329520 (JP, A) JP-A-2-203379 (JP , A) Japanese Unexamined Patent Publication No. 6-308491 (JP, A) Japanese Unexamined Patent Publication No. 4-358125 (JP, A) Actual Development No. 5-90448 (JP, U) Registered Utility Model 3001380 (JP, U) International Publication 94/01795 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 6/00 331 F21V 8/00 601 G02F 1/13357

Claims (6)

(57) [Claims] 1. A light-transmitting light guide plate in the shape of a quadrangle having long sides and short sides, and straight lines having different lengths that are provided so as to face end surfaces of the long sides and short sides adjacent to each other of the light guide plate. A backlight having an L-shaped lamp having a portion, and a reflector having an L-shape as a whole, which covers the L-shaped lamp and reflects the light emitted from the lamp toward the light guide plate. In the backlight described above, the depth of the short side reflector is larger than the depth of the long side reflector. 2. The reflector is characterized in that the long side reflector and the short side reflector have separate structures.
Backlight described in. 3. The L-shaped lamp is characterized in that at least both ends and a bent portion are supported by a lamp holder, and the lamp holder is attached to the reflector so as to be movable in a depth direction. The backlight according to claim 1 or claim 2. 4. The lamp holder is formed of an elastically deformable rubber material, and the lamp holder is press-fitted into the reflector so as to be movable in a depth direction. Backlight described in 5. The backlight according to claim 1, further comprising a lighting circuit for lighting the L-shaped lamp. 6. A liquid crystal display device, comprising: the backlight according to claim 1; and a liquid crystal display panel that receives light emitted from the backlight on its back surface. .