JP5207794B2 - Illumination device and liquid crystal display device - Google Patents

Description

  The present invention relates to a lighting device including a light guide plate and a light source disposed opposite to an end surface of the light guide plate, and a liquid crystal display device using the lighting device.

Conventionally, as an illuminating device used in a liquid crystal display device, a lighting device including a light guide plate disposed below a liquid crystal cell and a linear light source disposed along a side surface of the light guide plate is known (for example, a patent). Reference 1).
In such an illuminating device, the weight of the light guide plate is the largest, and when the illuminating device itself receives an impact such as when dropped, the light guide plate may move and damage the light source.

As a liquid crystal display device equipped with such an illumination device, there is a notebook type personal computer. However, the notebook type personal computer is particularly required to be strong and supports a light guide plate appropriately in an impact resistance test. We need to be able to do it.
Therefore, it is conceivable to provide a member for restricting the movement of the light guide plate between the light source and the light guide plate to prevent the light guide plate from moving when dropped, thereby protecting the light source.
JP 2006-250987 A

However, when a member for restricting the movement of the light guide plate is provided between the light source and the light guide plate and the light guide plate is received by the entire surface by this member, the movement of the light guide plate can be surely prevented at the time of dropping. However, the light supplied from the light source to the light guide plate is shielded at the place where this member is installed, and the display becomes dark around this area.
Therefore, an object of the present invention is to provide an illumination device and a liquid crystal display device that can achieve both improvement in impact resistance and ensuring appropriate luminance.

In order to solve the above-described problem, an illumination device according to the present invention includes a light source plate, a light source unit that is disposed to face an end surface of the light guide plate, and includes a linear light source that supplies light to the light guide plate, A light guide plate and the light source unit are arranged, a frame on which a light guide plate support part that restricts movement of the light guide plate in a direction approaching the linear light source is formed, the light guide plate support part, and the linear light source, And a reinforcing member that reinforces the light guide plate support, and the light guide plate support is between the linear light source and the light guide plate and faces the end of the light guide plate And has an opening formed at a central portion in the thickness direction of the light guide plate in the light guide plate support, and is thicker toward the fixed side of the frame, Reinforcing member corresponds to the opening of the light guide plate support It is characterized by having an opening that communicates is formed in position with the linear light source and the light guide plate that. In addition, the surface of the light guide plate support portion facing the end portion of the light guide plate may be formed so as to be substantially parallel to the surface forming the end portion of the light guide plate.

As a result, the light guide plate support part regulates the movement of the light guide plate in the direction of approaching the light source, so that even when the lighting device receives an impact, the support of the light guide plate is secured and the light guide plate is the light source. Can be prevented from being stressed, and as a result, problems occurring in the light source can be prevented.
Furthermore, since the gap portion is provided in the light guide plate support portion, it is possible to prevent light supplied from the light source to the light guide plate from being blocked, and to suppress a decrease in luminance near the light guide plate support portion. it can.

Further, a clearance portion for communicating the light source and the light guide plate can be formed in the vicinity of the thickness direction central portion of the light guide plate, Ru can improve the incidence efficiency from the light source to the light guide plate.

Furthermore, it is possible to effectively restrict the movement of the direction toward the light source of the light guide plate, Ru can be minimized to interfere with the supply of light to the light guide plate from the light source.

Furthermore, the light guide plate support part and the reinforcing member can restrict the movement of the light guide plate in the direction approaching the light source, and the light guide plate can be supported more strongly. At this time, since the reinforcing member is also provided with an opening, light supplied from the light source to the light guide plate can be secured.
Furthermore, in the illumination device according to the present invention, in the above, the light source unit has a lamp holder that holds an end of the linear light source, and the lamp holder is at least partially connected to the linear light source. An opening for communicating with the light guide plate is provided.
Thereby, the brightness | luminance fall in the edge part of a light source can be prevented.

Furthermore, in the illumination device according to the present invention, in the above, the light guide plate support portion is formed in a shape along the outer shape of the end surface of the light guide plate and the outer shape of the light source unit, and the end surface of the light guide plate The light source unit is in contact with the light source unit.
Thereby, while being able to support a light guide plate appropriately with a light guide plate support part, the intensity | strength of a light guide plate support part can be increased by increasing a contact area.

In addition, a liquid crystal display device according to the present invention includes any one of the above illumination devices and a liquid crystal panel irradiated with light from the illumination device.
As a result, it is possible to provide a liquid crystal display device equipped with an illumination device that secures light incident from the light source while supporting the light guide plate with sufficient strength, improving the impact resistance and improving the brightness and uniformity of the liquid crystal panel. A liquid crystal display device that achieves improvement can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a liquid crystal module 1 constituting a liquid crystal display device according to the present invention.
The liquid crystal module 1 includes a sidelight type backlight 10 and a liquid crystal panel 20, and the liquid crystal display device includes the liquid crystal module 1, a driver IC that drives the liquid crystal panel 20, and a signal control circuit thereof (not shown). Z)).

In this embodiment, a cold cathode fluorescent lamp (CCFL) 31 that is a linear light source is applied as a light source of the backlight 10. Lead wires (not shown) extend from both ends of the CCFL 31, and lamp holders 32 made of silicon resin or the like and covering the lead wires are provided at both ends of the CCFL 31.
The CCFL 31 is disposed opposite to a side surface of a light guide plate (not shown) located on the back side of the liquid crystal panel 20 and supplies light to the side surface of the light guide plate. The backlight 10 includes a resin frame 11 in which the liquid crystal panel 20 is installed while enclosing a CCFL 31, a light guide plate, and optical sheets described later.

The liquid crystal panel 20 is made of a transparent insulating material, for example, a glass substrate, the two substrates are opposed to each other at a predetermined interval, the outer periphery of the display area is bonded with a sealing material, and liquid crystal is sealed on the upper and lower surfaces thereof. The polarizing plate is attached.
FIG. 2 is a diagram showing a cross section taken along line AA ′ in FIG. 1.
The backlight 10 includes a light source unit 30 and optical sheets such as a reflection sheet 13, a light guide plate 14, a diffusion sheet 15, and lens sheets 16 and 17, which are resin frames (upper frame 11 and lower frame 12). Is held by.

  The light source unit 30 includes the CCFL 31 and the lamp holder 32 described above, and a reflector 33 arranged so as to surround the CCFL 31. The reflector 33 is made of, for example, aluminum or the like, and is formed in a U-shaped cross section that opens in the light emitting direction of the CCFL 31. With such a configuration, the light irradiated in all directions from the CCFL 31 is reflected by the reflector 33 and emitted to the opening side of the reflector 33.

The upper frame 11 is made of a resin material such as plastic and has a substantially frame shape. Similarly to the upper frame 11, the lower frame 12 is made of a resin material such as plastic and is formed in a box shape having an open front surface (upper side in FIG. 2).
The light source unit 30 is disposed on the side surface of the light guide plate 14 along the longitudinal direction of the light guide plate 14, and light from the CCFL 31 is incident on the side surface of the light guide plate 14. That is, the opening of the reflector 33 is provided toward the end surface of the light guide plate 14.

The light guide plate 14 emits light from the CCFL 31 from the upper surface of the light guide plate. As the light guide plate 14, a transparent plastic resin such as an acrylic resin is used. The reflection sheet 13 is disposed on the lower surface of the light guide plate 14 so that light incident from the light guide plate incident surface does not exit from a surface other than the upper surface of the light guide plate.
The diffusion sheet 15 further scatters and uniforms the light that cannot be made uniform by the diffusion pattern of the light guide plate 14 and also makes the direct light of the light source difficult to see.

The light thus guided is collected by the lens sheets 16 and 17 and is guided to the back surface of the liquid crystal panel 20.
Note that the diffusion sheet and the lens sheet are not limited to the number of sheets and the stacking order as long as sufficient brightness can be obtained for the liquid crystal panel 20.
A part of the back surface of the liquid crystal panel 20 is pasted on the installation portion 11 a formed on the upper frame 11. Thereby, the liquid crystal module 1 in a state where the backlight 10 is disposed on the back surface of the liquid crystal panel 20 is completed.

The upper frame 11 is formed with a support portion 41 for restricting movement of the light guide plate 14 toward the CCFL 31 side. The support portion 41 is integrally formed on the back surface of the frame body 11 b of the upper frame 11 so as to protrude in the thickness direction (Z direction) of the light guide plate 14.
In this embodiment, the support part 41 shall be arrange | positioned so that it may be located between the lamp holder 32 and the light-guide plate 14 in the both ends of CCFL31. Further, the support portion 41 is formed in a shape in which the side surface 41 a on the light guide plate 14 side is in contact with the end surface 14 a of the light guide plate 14 and the side surface 41 b on the CCFL 31 side is in contact with the side surface 32 a of the lamp holder 32. With such a configuration, movement of the light guide plate 14 toward the CCFL 31 (Y direction) is restricted.

The length of the support portion 41 in the protruding direction is set so that the bottom surface 41 c of the support portion 41 is positioned above the bottom surface 14 b of the light guide plate 14.
Further, the lamp holder 32 is formed with a hole 32 b for allowing the light of the CCFL 31 to pass through at least a part of the surface facing the light guide plate 14.
As a result, a gap is formed to allow the CCFL 31 and the light guide plate 14 to communicate with each other. The positional relationship between the gap formed by the support portion 41 and the hole 32b of the lamp holder 32 is set so that light from the CCFL 31 can easily enter the light guide plate 14.

In FIG. 2, the upper frame 11 and the lower frame 12 correspond to the frame, and the support portion 41 corresponds to the light guide plate support portion.
By the way, a portable computer such as a notebook type personal computer is required to have sufficient strength because it is highly likely to receive an impact due to dropping or the like. Moreover, in the illuminating device (backlight) used for a liquid crystal display device, since a light guide plate may move and it may damage a light source at the time of fall, it is calculated | required that a light guide plate can be supported appropriately in an impact resistance test.

  Therefore, as shown in FIG. 3, a support portion 141 that restricts the movement of the light guide plate 114 is provided between the light source 131 and the light guide plate 114 to prevent the light guide plate 114 from moving when the light guide plate 114 is dropped, thereby protecting the light source 131. In this case, if the structure is such that the light guide plate 114 is received over the entire surface of the support portion 141, the light supplied from the light source 131 to the light guide plate 114 is shielded at the place where the support portion 141 is installed. Will darken the display.

On the other hand, in this embodiment, since the clearance part which connects CCFL31 and the light-guide plate 14 is provided in the support part 41 and the lamp holder 32, the light from CCFL31 can be permeate | transmitted to the light-guide plate 14, and a support part It is possible to prevent the luminance around 41 from decreasing.
Thus, in the said 1st Embodiment, since the light guide plate support part which controls the movement to the direction which approaches a light source of a light guide plate is provided between a light source and a light guide plate, the illuminating device received the impact Even in this case, it is possible to maintain the support of the light guide plate and prevent the light guide plate from applying stress to the light source, and as a result, it is possible to prevent problems occurring in the light source.

In addition, the light guide plate support portion is provided with a gap portion that allows the light source and the light guide plate to communicate with each other, so that the light supplied from the light source to the light guide plate can be prevented from being blocked, and the luminance near the light guide plate support portion can be prevented. Can be suppressed.
Furthermore, since the light guide plate support part is integrally formed on the frame on which the light source and the light guide plate are arranged, it is not necessary to separately add parts for supporting the light guide plate, and the number of parts can be reduced.

In addition, since the light guide plate support portion is disposed opposite to the end portion of the light guide plate, the light supply from the light source to the light guide plate can be minimized.
Furthermore, since a gap portion for communicating the light source and the light guide plate is provided in the lamp holder that holds the end portion of the light source, it is possible to more effectively prevent a decrease in luminance at the end portion of the light source.
Also. Since the light guide plate support part is formed into a shape along the outer shape of the end face of the light guide plate and the outer shape of the light source unit, the light guide plate support part can be made thicker toward the side fixed to the frame, and the strength Can be increased. Furthermore, since the end face of the light guide plate and the light source unit are brought into contact with each other, the light guide plate can be properly supported by the light guide plate support portion, and the strength of the light guide plate support portion can be increased by increasing the contact area.

And by setting it as a liquid crystal display device which mounts such a backlight, it can be set as the liquid crystal display device which implement | achieved the improvement of impact resistance, and the improvement of the brightness | luminance and uniformity of a liquid crystal panel.
In the first embodiment, the case has been described in which the gap portion that allows the CCFL 31 and the light guide plate 14 to communicate with each other is formed by adjusting the length of the support portion 41. However, as shown in FIG. By adding a slit 41d to 41, a gap (opening) can also be formed.

  In this case, the length of the support portion 41 in the protruding direction is set so that the bottom surface 41 c of the support portion 41 is at the same height as the bottom surface 14 b of the light guide plate 14, and the slit 41 d is formed at the central portion in the thickness direction of the light guide plate 14. Form in the vicinity. Further, the lamp holder 32 is formed with a hole 32b for allowing the light of the CCFL 31 to pass through at a position facing the slit 41d. With such a configuration, the incident efficiency of light from the CCFL 31 to the light guide plate 14 can be improved.

Next, a second embodiment of the present invention will be described.
In the second embodiment, a reinforcing metal fitting that reinforces the light guide plate support and protects the light source is added to the first embodiment described above to further improve the robustness.
FIG. 5 is a front view of the liquid crystal module 1 according to the second embodiment.
In the second embodiment, parts having the same configuration as the liquid crystal module 1 shown in FIGS. 1 and 2 are given the same reference numerals as those in FIGS. explain.

The light source unit 30 includes a reinforcing metal fitting 34 as a reinforcing member that is a part of the lamp holder 32 and that fits in a portion facing the light guide plate 14.
FIG. 6 is a view showing a BB ′ cross section in FIG. 5.
As shown in FIG. 6, the reinforcing bracket 34 is a substantially U-shaped member made of metal and reinforces the lamp holder 32 so that the lamp holder 32 is surrounded by the reinforcing bracket 34 from the light guide plate 14 side. The metal fitting 34 is fitted.

The upper frame 11 is formed with a support portion 42 for restricting the movement of the light guide plate 14 toward the CCFL 31 side. Like the support portion 41 in the first embodiment described above, the support portion 42 protrudes in the thickness direction (Z direction) of the light guide plate 14 on the back surface of the frame 11b where the liquid crystal panel 20 is installed. It is integrally molded.
And the support part 42 is arrange | positioned so that it may be located between the reinforcement metal fitting 34 and the light-guide plate 14 in the both ends of CCFL31. Further, the support portion 42 is shaped so that the side surface 42 a on the light guide plate 14 side abuts on the end surface 14 a of the light guide plate 14, and the side surface 42 b on the CCFL 31 side abuts on the side surface 34 a of the reinforcing bracket 34. With such a configuration, movement of the light guide plate 14 toward the CCFL 31 (Y direction) is restricted.

Further, the length of the support portion 42 in the protruding direction is set so that the bottom surface 42 c of the support portion 42 has the same height as the bottom surface 14 b of the light guide plate 14.
Further, the support portion 42 is formed with a slit 42d in the vicinity of the central portion in the thickness direction of the light guide plate 14, and the reinforcing spacer 34 and the lamp holder 32 allow the CCFL 31 light to pass through the portions facing the slit 42d, respectively. Holes 34b and 32b are formed. As a result, an opening for communicating the CCFL 31 and the light guide plate 14 is formed.

Since the upper frame 11 is a resin frame, when the light guide plate 14 is held only by the support part integrally formed with the upper frame 11, the strength may be insufficient depending on the shape of the support part. By providing the reinforcing metal fitting 34 as in this embodiment, the light guide plate 14 can be supported with higher strength.
As described above, in the second embodiment, the reinforcing metal fitting is provided between the light source and the light guide plate support portion so as to surround the light source from the light guide plate side. The movement of the light guide plate in the direction approaching the light source can be restricted. As a result, the light source plate can be supported more strongly and the light source can be protected. Further, at this time, since the opening is also provided in the reinforcing metal fitting, light supplied from the light source to the light guide plate can be secured.

In each of the above embodiments, the shape and number of the openings provided in the support portions 41 and 42 can ensure the strength of the support portions 41 and 42 and do not shield the light from the CCFL 31. It can be set as appropriate.
Further, in each of the above embodiments, the case where the illumination device according to the present invention is applied to a backlight of a liquid crystal display device has been described. However, the illumination device can also be applied to a sidelight or a frontlight.

It is a top view of the liquid crystal module in a 1st embodiment. It is AA 'sectional drawing of FIG. It is sectional drawing which shows the comparative example of a liquid crystal module. It is a figure which shows the modification of a support part. It is a top view of the liquid crystal module in a 2nd embodiment. It is BB 'sectional drawing of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal module, 10 ... Back light, 11 ... Upper frame, 12 ... Lower frame, 13 ... Reflection sheet, 14 ... Light guide plate, 15 ... Diffusion sheet, 16, 17 ... Lens sheet, 20 ... Liquid crystal panel, 30 ... Light source Unit 31 ... Cold cathode fluorescent lamp (CCFL) 32 ... Lamp holder 32b ... Hole 33 ... Reflector 34 ... Reinforcing metal fitting 34b ... Hole 41, 42 ... Supporting part 42d ... Slit

Claims (5)

A light guide plate;
A light source unit that is arranged to face the end face of the light guide plate and has a linear light source that supplies light to the light guide plate;
A frame on which the light guide plate and the light source unit are arranged, and a light guide plate support portion for restricting movement of the light guide plate in a direction approaching the linear light source ;
A reinforcing member that is disposed between the light guide plate support and the linear light source and reinforces the light guide plate support;
With
The light guide plate support is disposed between the linear light source and the light guide plate at a position facing the end of the light guide plate, and the thickness of the light guide plate in the light guide plate support It has an opening formed in the central portion in the vertical direction and is thicker toward the fixed side of the frame,
The lighting device according to claim 1, wherein the reinforcing member has an opening formed at a position corresponding to the opening of the light guide plate support portion to communicate the linear light source and the light guide plate . The surface of the light guide plate support portion facing the end portion of the light guide plate is formed to be substantially parallel to the surface forming the end portion of the light guide plate.
  The lighting device according to claim 1.   The light source unit includes a lamp holder that holds an end portion of the linear light source, and the lamp holder includes an opening that at least partially communicates the linear light source and the light guide plate.
  The illumination device according to claim 1, wherein   The light guide plate support portion is formed in a shape along the outer shape of the end surface of the light guide plate and the outer shape of the light source unit, and is in contact with the end surface of the light guide plate and the light source unit.
  The lighting device according to any one of claims 1 to 3, wherein   5. The lighting device according to claim 1, and a liquid crystal panel irradiated with light from the lighting device.
  A liquid crystal display device characterized by the above.

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