JP3979615B2 - Liquid crystal display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device, and more particularly to a technique for assembling a backlight unit and a liquid crystal driving circuit board to a liquid crystal display panel.
[0002]
[Prior art]
In a transmissive or transflective liquid crystal display device, a backlight unit and a liquid crystal driving circuit board are provided on the back side of the liquid crystal display panel, and these members are relatively disposed within a holder (exterior or interior case). It is fixed in a positioned state.
[0003]
An example thereof will be described with reference to FIG. 6. In a conventional liquid crystal display device, a metal box having a display window 1 a on one side (front side) and the other side (back side) opened. A holder 1 is used.
[0004]
A caulking piece 2 that can be cut and raised toward the inner side of the holder 1 is provided at an edge of the side frame 1b of the holder 1 on the opening side. Since FIG. 6 is a partial perspective view of the holder 1, only one caulking piece 2 is shown. Actually, however, about two caulking pieces 2 are provided on each side frame 1 b facing each other. It has been.
[0005]
To assemble as an apparatus, first, the liquid crystal display panel 3 is placed in the holder 1 and arranged along the display window 1a. Next, the backlight unit 4 and the liquid crystal driving circuit board 5 are sequentially stacked on the back side (upper side in the drawing) of the liquid crystal display panel 3 and stored in the case 1.
[0006]
Thereafter, the caulking piece 2 is bent along the substrate surface of the liquid crystal driving circuit board 5. Thereby, the liquid crystal display panel 3, the backlight unit 4, and the liquid crystal driving circuit board 5 can be fixed in the holder 1.
[0007]
[Problems to be solved by the invention]
Although the configuration itself is simple, the conventional example has the following problems. That is, since the caulking pieces 2 at a plurality of positions must be bent one by one with a tool such as pliers, the bending work takes time.
[0008]
Further, when disassembling, each caulking piece 2 is folded back to its original position, but if this is repeated, the caulking piece 2 may be broken at the root due to metal fatigue.
[0009]
Furthermore, when the connection terminal portion of the liquid crystal display panel 3 and the liquid crystal driving circuit board 5 are connected via an anisotropic conductive rubber connector (not shown), an appropriate pressure is always applied between them. The state must be maintained. For this purpose, it is necessary to increase the rigidity of the holder 1 itself, which increases the design burden.
[0010]
On the other hand, for mobile phones and the like, weight reduction in units of several grams is required. Along with this, review of the weight of liquid crystal display devices used therefor is also required, and the use of metal holders (cases) that occupy a large specific gravity with respect to the total weight is particularly questioned.
[0011]
[Means for Solving the Problems]
The present invention has been made in order to solve the above-described conventional problems, and its purpose is that the assembly workability of the three members of the liquid crystal display panel, the backlight unit, and the liquid crystal driving circuit board is good, and those An object of the present invention is to provide a liquid crystal display device which can maintain the relative positional relationship over a long period of time without being affected by temperature or the like.
[0012]
To achieve the above object, the present invention, the first and second transparent electrode substrates made by crimping via a peripheral sealing material, and the liquid crystal display panel having a connection terminal portion to the first transparent electrode substrate, the A backlight unit including a light guide plate attached to the second transparent electrode substrate side of the liquid crystal display panel, and an anti-liquid crystal display panel side of the light guide plate, and an anisotropic conductive rubber connector interposed between the connection terminal portions. And a circuit board for driving a liquid crystal connected to each other, the light guide plate includes a first engagement claw that engages with a peripheral edge of the first transparent electrode substrate, and a peripheral edge of the circuit board. A second engaging claw that engages, and the first and second engaging claws share the same base portion, and the base portion serves as a fulcrum and is integrally swingable on a side end surface of the light guide plate in a seesaw shape. attached by the first and second engagement claw And the connection terminal portion and the circuit board is characterized in that to avoid separating at repulsive force of the anisotropic conductive rubber connectors, their spacing is maintained.
[0013]
According to this configuration, since the liquid crystal display panel and the liquid crystal driving circuit board are held via the light guide plate of the backlight unit, a conventional metal holder becomes unnecessary. Therefore, it is possible to reduce the weight and size.
[0014]
In addition, the liquid crystal display panel and the liquid crystal driving circuit board need only be hooked on the engaging claws of the light guide plate, and can be easily assembled by a so-called one-touch operation.
[0015]
In addition, since the base portions of the first and second engaging claws are the same base portion, and each engaging claw can be swung in a seesaw shape with the base portion as a fulcrum, the resin is softened due to high temperature , for example. Even if one engaging claw is about to come off, the movement of the other engaging claw is suppressed, so that the coming off of the engaging claw is sealed.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be described in more detail on the basis of the embodiments shown in the drawings. FIG. 1 is an enlarged side view of a main part of a liquid crystal display device 10 according to this embodiment, and a part thereof is shown as a cross section.
[0017]
According to this, the liquid crystal display device 10 includes a liquid crystal display panel 11, a backlight unit, and a circuit board 31 for driving the liquid crystal. The light guide plate of the backlight unit is drawn for convenience of drawing. Only 21 is shown.
[0018]
The liquid crystal display panel 11 includes a first transparent electrode substrate 12 and a second transparent electrode substrate 13 bonded together with a peripheral sealing material (not shown), and a connection terminal portion is provided on the first transparent electrode substrate 12 side. 121 is continuously provided. Polarizing plates 14 and 14 are attached to the transparent electrode substrates 12 and 13, respectively.
[0019]
In this embodiment, the first transparent electrode substrate 12 is a front panel (F plate) and the second transparent electrode substrate 13 is a rear panel (R plate). Therefore, the light guide plate of the backlight unit on the second transparent electrode substrate 13 side. 21 is arranged.
[0020]
Although not shown, the connection terminal portion 121 is formed with an extraction electrode group. In this embodiment, the liquid crystal display panel 11 is a COG (chip on glass) type, and a liquid crystal driving IC 15 is surface-mounted on the connection terminal portion 121.
[0021]
The light guide plate 21 is made of a translucent synthetic resin plate such as polycarbonate or acrylic resin. In this liquid crystal display device 10, the backlight unit is of a side light type and is not shown, but a light source such as a CFL (cold cathode tube) or LED (light emitting diode) is disposed on the side of the light guide plate 21. Yes.
[0022]
A circuit board 31 is disposed on the side of the light guide plate 21 opposite to the liquid crystal display panel (the lower surface side in FIG. 1). That is, the circuit board 31 is disposed opposite to the liquid crystal display panel 11 with the light guide plate 21 interposed therebetween.
[0023]
Although not shown, the circuit board 31 is mounted with electronic components for driving liquid crystal, an inverter power source for driving the backlight, and the like, and an electrode terminal group corresponding to the lead electrode group of the connection terminal portion 121. Is formed.
[0024]
In the liquid crystal display device 10, an anisotropic conductive rubber connector 41 is used as a connection means for connecting the extraction electrode group of the connection terminal portion 121 and the electrode terminal group of the circuit board 31. The anisotropic conductive rubber connector 41 may be either a conductive particle dispersed in rubber or a conductive fine wire embedded in rubber (commonly called zebra rubber).
[0025]
The light guide plate 21 is provided with engaging claws 23 for holding the liquid crystal display panel 11 and the circuit board 31 on both sides. First, the overall structure of the light guide plate 21 is shown in FIGS. Will be described. 2 is a front view of the light guide plate 21, FIG. 3 is a bottom view thereof (a view of the light guide plate 21 seen from below in FIG. 2), and FIG. 4 is a right side view.
[0026]
In addition to the original light guide region 211 that irradiates light toward the display region of the liquid crystal display panel 11, the light guide plate 21 further includes an extension portion 212 that extends along the connection terminal portion 121 of the liquid crystal display panel 11. I have.
[0027]
That is, the outer shape of the light guide plate 21 is substantially the same as the outer shape of the liquid crystal display panel 11 including the connection terminal portion 121, and the anisotropic conductive rubber connector 41 is connected to the connection terminal portion on the end side of the extension portion 212. An opening 22 is formed between the circuit board 31 and the circuit board 31.
[0028]
The light guide plate 21 has a rectangular shape when viewed from the front in FIG. 2, and engagement claws 23 are provided on the remaining three sides 21 b to 21 d excluding the lower side 21 a on the lower side in FIG. 2. That is, the liquid crystal display panel 11 and the circuit board 31 are attached to the light guide plate 21 from the lower side 21a side. In this embodiment, two engaging claws 23 are provided for each of the sides 21b to 21d.
[0029]
Each engaging claw 23 has the same configuration, and one of them is shown as a perspective view in FIG. According to this, the engagement claw 23 includes a first engagement claw 24 for the liquid crystal display panel 11 and a second engagement claw 25 for the circuit board 31.
[0030]
In this case, the interval between the first engagement claw 24 and the second engagement claw 25 is appropriate for the anisotropic conductive rubber connector 41 when the liquid crystal display panel 11 and the circuit board 31 are sandwiched therebetween. It is set to the interval at which the compression force is applied.
[0031]
In the present invention, the first engagement claw 24 and the second engagement claw 25 is one common base 26 are integrally formed on the side end surface 213 of the light guide plate 21 via the same base 26. That is, the first engagement claw 24 and the second engagement claw 25 can swing in a seesaw shape with the base portion 26 as a fulcrum.
[0032]
The first engagement claw 24 is formed so as to rise from the base portion 26 toward the liquid crystal display panel 11 and engage with the peripheral edge of the first transparent electrode substrate 12 as the F plate. The second engagement claw 25 is formed so as to rise from the base 26 toward the circuit board 31 in the opposite direction to the first engagement claw 24 and engage with the periphery thereof.
[0033]
Each of the engaging claws 24 and 25 can be elastically deformed. In this embodiment, however, the engaging claws 24 and 25 are provided with openings 241 and 251 in order to make the movement more flexible. Has been.
[0034]
According to this configuration, the liquid crystal display panel 11 is formed by inserting the first transparent electrode substrate 12 as the F plate as an upper side in FIG. 1 from the lower side 21a side of the light guide plate 21 along the one surface. Attached to the light guide plate 21, the peripheral edges thereof including the connection terminal portion 121 are pressed by the first engaging claws 24.
[0035]
Similarly, the circuit board 31 is also attached to the light guide plate 21 by being inserted along the other side from the lower side 21 a side of the light guide plate 21, and the peripheral edge thereof is pressed by the second engaging claws 25.
[0036]
In this case, an anisotropic conductive rubber connector 41 is interposed between the liquid crystal display panel 11 and the circuit board 31, but the liquid crystal display panel 11 and the circuit board 31 are connected to the first engagement claw 24 and the second engagement claw 24. The engagement claw 25 keeps the distance between them constant, so that a reliable electrical connection state is ensured.
[0037]
Incidentally, since the engaging claw 23 is formed of the same resin material as that of the light guide plate 21, it is softened in a high temperature atmosphere. If so, there is a risk that the anisotropic conductive rubber connector 41 may be removed due to the repulsive force.
[0038]
However, since the first engaging claw 24 and the second engaging claw 25 share the base portion 26 as described above and can swing in a seesaw shape with the base portion 26 as a fulcrum, the engaging claw 23 is anisotropic. The conductive conductive rubber connector 41 is not removed by the repulsive force.
[0039]
That is, when the resin is softened due to a high temperature, even if a turning force in the clockwise direction in FIG. 1 acts on the first engagement claw 24 side due to the repulsive force of the anisotropic conductive rubber connector 41, the opposite first Since the movement is suppressed by the two engaging claws 25, the disengagement of the engaging claws is sealed.
[0040]
In the above embodiment, the liquid crystal display panel 11 and the circuit board 31 are inserted into the light guide plate 21 from the lower side 21a side. However, unlike this, the liquid crystal display panel 11 and the circuit board 31 are inserted into the light guide plate 21. The engaging claws 24 and 25 can be deformed from the direction orthogonal to the plate surface and forcedly pushed in.
[0041]
【The invention's effect】
As described above, according to the present invention, the light guide plate of the backlight unit is provided with the first engagement claw for holding the liquid crystal display panel and the second engagement claw for holding the circuit board, so that the liquid crystal display By assembling the panel, the light guide plate, and the circuit board, a conventionally used holder made of metal, for example, becomes unnecessary.
[0042]
Therefore, since the holder is not required, the weight and size can be reduced, and the cost can be reduced. Moreover, even if it is assembled, the workability is greatly improved because it is a fitting type. Furthermore, even if the resin is softened due to a high temperature, there is no risk that the engaging claws will come off, and the reliability is high.
[Brief description of the drawings]
FIG. 1 is an enlarged side view of a main part showing a cross section of a part of a liquid crystal display device according to an embodiment of the present invention.
FIG. 2 is a front view of a light guide plate used in the embodiment.
FIG. 3 is a bottom view of the light guide plate.
FIG. 4 is a right side view of the light guide plate.
FIG. 5 is a perspective view of an engaging claw provided on the light guide plate.
FIG. 6 is an exploded perspective view showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Liquid crystal display device 11 Liquid crystal display panel 12, 13 Transparent electrode board 121 Connection terminal part 21 Light guide plate 22 Opening part 23 Engagement claw 24 1st engagement claw 25 2nd engagement claw 26 Base 31 Circuit board 41 Anisotropic conduction Rubber connector

Claims (1)

The first and second transparent electrode substrates made by crimping via a peripheral sealing material, and the liquid crystal display panel having a connection terminal portion to the first transparent electrode substrate, the second transparent electrode substrate side of the liquid crystal display panel A backlight unit including a light guide plate provided; a circuit board for driving a liquid crystal disposed on an anti-liquid crystal display panel side of the light guide plate and connected to the connection terminal portion via an anisotropic conductive rubber connector; In a liquid crystal display device comprising:
The light guide plate includes a first engagement claw that engages with a peripheral edge of the first transparent electrode substrate, and a second engagement claw that engages with a peripheral edge of the circuit board, and the first and second engagements. The claws share the same base, and are integrally attached to the side end surface of the light guide plate so as to be swingable in a seesaw shape with the base as a fulcrum, and the connection terminal portion and the A liquid crystal display device characterized in that a distance between the circuit board and the circuit board is maintained so as not to be separated by a repulsive force of the anisotropic conductive rubber connector.

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