JP3794456B2 - Liquid crystal display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device.
[0002]
[Prior art]
The liquid crystal display panel has a configuration in which each transparent substrate arranged opposite to each other with a liquid crystal is used as an envelope, and a large number of pixels are formed in the liquid crystal spreading direction.
[0003]
Since the pixel only has a function of controlling the amount of light transmitted therethrough, a so-called backlight is usually arranged on the back surface of the liquid crystal display panel.
[0004]
For this reason, the liquid crystal display panel and the backlight are accommodated by a so-called upper frame that is arranged on the liquid crystal display panel side and has an opening formed in the display area of the liquid crystal display panel. In general, it is configured to be modularized.
[0005]
Here, the resin frame mainly has a function of accommodating a backlight, and at the same time, a so-called mask that supports the liquid crystal display panel and irradiates only the display area of the liquid crystal display panel with light from the backlight. It also has the function of
[0006]
[Problems to be solved by the invention]
However, it has been pointed out that the liquid crystal display device having such a configuration has room for further improvement as the size thereof tends to increase.
[0007]
That is, the resin frame that accommodates the large-sized backlight is required to have higher mechanical strength than before, and as a result, it is forced to increase the thickness of the resin frame.
[0008]
This means that the width of the module frame extending outward from the display area of the liquid crystal display panel is increased, and so-called frame size cannot be reduced.
[0009]
Further, as described above, the resin frame supports the liquid crystal display panel and has a mask function for irradiating only the display area of the liquid crystal display panel with light from the backlight. In addition, shadows are formed around the display area of the liquid crystal display panel.
[0010]
Since the thickness of the portion corresponding to the mask of the resin frame is relatively large, the optical path of light from the backlight is blocked at this portion, and light is not emitted around the display area of the liquid crystal display panel as viewed from the observation side. There was a case where the shadow of was recognized.
[0011]
The present invention has been made based on such circumstances, and an object of the present invention is to provide a liquid crystal display device capable of ensuring the strength of a resin frame without enlarging a so-called frame regardless of an increase in size. It is in.
[0012]
Another object of the present invention is to provide a liquid crystal display device in which no shadow of light is observed around the display area of the liquid crystal display panel as viewed from the observation side.
[0013]
[Means for Solving the Problems]
Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
[0014]
That is, a liquid crystal display panel, a backlight disposed on the back surface of the liquid crystal display panel, a resin frame disposed on the backlight side, and a portion disposed on the liquid crystal display panel side and corresponding to the display area In a liquid crystal display device modularized with an upper frame in which an opening is formed,
A medium frame having an opening formed in a portion corresponding to a display area of the liquid crystal display panel is provided between the liquid crystal display panel and a backlight, and the medium frame is made of a metal plate. It is.
[0015]
According to such a liquid crystal display device, the resin frame can be reinforced by the middle frame made of a metal plate. This does not increase the thickness of the resin frame and can avoid an increase in the so-called frame.
[0016]
Moreover, the thickness can be reduced by using an intermediate frame made of such a metal plate. For this reason, when the middle frame has a mask function that irradiates only the display area of the liquid crystal display panel with light from the backlight and does not irradiate the periphery of the display area, the contour of the opening is positioned correctly. Accordingly, it is possible to avoid the shadow of light from being recognized around the display area of the liquid crystal display panel as viewed from the observation side.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a liquid crystal display device according to the present invention will be described below with reference to the drawings.
[0018]
Example 1.
[Equivalent circuit of liquid crystal display]
The liquid crystal display device of this embodiment is of a so-called lateral electric field type active matrix type, and its equivalent circuit is as shown in FIG.
[0019]
In FIG. 2, first, there is a liquid crystal display panel 100. The liquid crystal display panel 100 includes a plurality of pixels whose display portions are arranged in a matrix, and each pixel is transmitted from the backlight unit 300 disposed on the back of the liquid crystal display panel 100. It is configured so that light can be modulated and controlled independently.
[0020]
The light modulation in each pixel employs a method called a transverse electric field method, and the configuration thereof will be described in detail later. In the liquid crystal layer interposed between the transparent substrates 1A and 1B arranged to face each other. The electric field to be generated is parallel to the transparent substrates 1A and 1B.
[0021]
Such a liquid crystal display panel 100 is known to be capable of recognizing a clear image even when observed from a large angle visual field with respect to the display surface, and is excellent in a so-called wide angle visual field.
[0022]
That is, on the liquid crystal side surface of one transparent substrate 1A among the transparent substrates 1A and 1B arranged to face each other via the liquid crystal of the liquid crystal display panel 100, the x direction (row direction) extends in the y direction (column direction). The scanning signal line 2 and the reference signal line 4 arranged in parallel in the direction) are formed.
[0023]
In this case, in the same figure, from above the transparent substrate 1A, the scanning signal line 2, the reference signal line 4 close to the scanning signal line 2, the scanning signal line 2 relatively separated from the reference signal line 4, The scanning signal lines 2 are arranged in order, such as a reference signal line 4 adjacent to the scanning signal line 2.
[0024]
A video signal line 3 is formed that is insulated from the scanning signal line 2 and the reference signal line 4, extends in the y direction, and is juxtaposed in the x direction.
[0025]
Here, a unit pixel is formed in each rectangular area having a relatively wide area surrounded by the scanning signal line 2, the reference signal line 4, and the video signal line 3, and each unit pixel is in a matrix shape. Arranged to form a display surface. The detailed configuration of this pixel will be described in detail below.
[0026]
The liquid crystal display panel 100 includes a vertical scanning circuit 5 and a video signal driving circuit 6 as external circuits. The vertical scanning circuit 5 sequentially supplies a scanning signal (voltage) to each of the scanning signal lines 2. The video signal (voltage) is supplied from the video signal driving circuit 6 to the video signal line 3 in accordance with the timing.
[0027]
The vertical scanning circuit 5 and the video signal drive circuit 6 are supplied with power from the liquid crystal drive power supply circuit 7, and the image information from the CPU 8 is separately input by the controller 9 into display data and control signals. It is like that.
[0028]
The liquid crystal display panel 100 having the above-described configuration is provided with a reference signal line 4 in particular, and a reference voltage signal applied to the reference signal line 4 is also supplied from the liquid crystal drive power supply circuit 7.
[0029]
[Overall configuration of liquid crystal display device]
FIG. 1 is an exploded perspective view showing an embodiment of a liquid crystal display device according to the present invention.
[0030]
The liquid crystal display device shown in the figure is roughly divided into a liquid crystal display panel module 400, a backlight unit 300, a resin frame 500, a middle frame 700, an upper frame 800, etc., which are modularized.
[0031]
Hereinafter, each of these members will be described sequentially.
[0032]
[LCD panel module]
The liquid crystal display panel module 400 includes a liquid crystal display panel 100, a vertical scanning circuit 5 composed of a plurality of semiconductor ICs mounted around the liquid crystal display panel 100, a video signal driving circuit 6, and input terminals of these driving circuits. 2 corresponds to a portion surrounded by a dotted frame P of the equivalent circuit of FIG.
[0033]
That is, an output from the controller substrate 33, which will be described in detail later, is input to the vertical scanning circuit 5 and the video signal driving circuit 6 on the liquid crystal display panel 100 via the gate substrate 30 and the drain substrate 31, and the outputs of these driving circuits are The signal is input to the scanning signal line 2 and the video signal line 3 of the liquid crystal display panel 100.
[0034]
Here, as described above, the liquid crystal display panel 100 is composed of a large number of pixels whose display region portions are arranged in a matrix, and the configuration of one of these pixels is shown in FIG. 3 (dotted line frame in FIG. 2). (Corresponding to the area surrounded by O). 3 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a sectional view taken along line V-V, and FIG. 6 is a sectional view taken along line VI-VI.
[0035]
In FIG. 3, a reference signal line 4 extending in the x direction and a scanning signal line 2 are formed on the main surface of the transparent substrate 1 </ b> A so as to be relatively separated from and parallel to the reference signal line 4 in the (−) y direction. Has been.
[0036]
Here, three reference electrodes 14 are integrally formed on the reference signal line 4. That is, two of the reference electrodes 14 are in the y direction side of a pixel region formed by a pair of video signal lines 3 described later, that is, in the (−) y direction in the vicinity of the video signal lines 3. It is formed extending to the vicinity of the scanning signal line 2, and the remaining one is formed between them.
[0037]
Then, the surface of the transparent substrate 1A on which the scanning signal line 2, the reference signal line 4, and the reference electrode 14 are formed is covered with the scanning signal line 2 and the like, and an insulating film 15 made of, for example, a silicon nitride film (FIG. 4). , FIG. 5 and FIG. 6) are formed. This insulating film 15 is stored as an interlayer insulating film for the intersection of the scanning signal line 2 and the reference signal line 4 for the video signal line 3 described later, and as a gate insulating film for the formation region of the thin film transistor TFT. The region where the capacitor Cstg is formed functions as a dielectric film.
[0038]
A semiconductor layer 16 is first formed on the surface of the insulating film 15 in the region where the thin film transistor TFT is formed. The semiconductor layer 16 is made of, for example, amorphous Si, and is formed on the scanning signal line 2 so as to overlap with a portion adjacent to the video signal line 3. As a result, a part of the scanning signal line 2 also serves as the gate electrode of the thin film transistor TFT.
[0039]
On the surface of the insulating film 15 formed in this way, as shown in FIG. 3, video signal lines 3 extending in the y direction and arranged in parallel in the x direction are formed.
[0040]
The video signal line 3 is integrally provided with a drain electrode 3A formed so as to extend to a part of the surface of the semiconductor layer 16 of the thin film transistor TFT.
[0041]
Further, a display electrode 18 is formed on the surface of the insulating film 15 in the pixel region. The display electrode 18 is formed so as to run between the reference electrodes 14. That is, one end of the display electrode 18 also serves as the source electrode 18A of the thin film transistor TFT, and extends as it is in the (+) y direction, and further extends in the x direction along the reference signal line 4, and then (-). It has a U shape extending in the direction and having the other end.
[0042]
In this case, a portion of the display electrode 18 that is superimposed on the reference signal line 4 constitutes a storage capacitor Cstg including the insulating film 15 as a dielectric film between the reference signal line 4. For example, when the thin film transistor TFT is turned off, the storage capacitor Cstg has an effect of storing video information in the display electrode 18 for a long time.
[0043]
Note that the surface of the semiconductor layer 16 corresponding to the interface between the drain electrode 3A and the source electrode 18A of the thin film transistor TFT described above is doped with phosphorus (P) to form a high concentration layer. Contact is being made. In this case, the high-concentration layer is formed over the entire surface of the semiconductor layer 16, and after forming each electrode, the high-concentration layer other than the electrode formation region is etched using the electrode as a mask. It can be set as said structure.
[0044]
A protective film 19 (for example, a silicon nitride film) is formed on the upper surface of the insulating film 15 on which the thin film transistor TFT, the video signal line 3, the display electrode 18, and the storage capacitor Cstg are formed as described above (FIGS. 4, 5, and 6). The alignment film 20 is formed on the upper surface of the protective film 19 to constitute the transparent substrate 1A of the liquid crystal display panel 100. A polarizing plate 21 is disposed on the surface of the transparent substrate 1A opposite to the liquid crystal layer.
[0045]
Further, as shown in FIG. 4, a light shielding film 22 is formed in a portion corresponding to a boundary portion of each pixel region on the liquid crystal side portion of the transparent substrate 1B. The light shielding film 22 has a function for preventing the light from being directly applied to the thin film transistor TFT and a function for improving the display contrast. The light shielding film 22 is formed in a region indicated by a broken line in FIG. 3, and an opening formed therein constitutes a substantial pixel region.
[0046]
Further, a color filter 23 is formed covering the opening of the light shielding film 22, and the color filter 23 has a color different from that in the pixel region adjacent in the x direction and has a boundary portion on the light shielding film 22. It is like that. Further, a flat film 24 made of a resin film or the like is formed on the surface on which the color filter 23 is formed, and an alignment film 25 is formed on the surface of the flat film 24. A polarizing plate 26 is disposed on the surface of the transparent substrate 1B opposite to the liquid crystal layer.
[0047]
〔Backlight〕
A backlight unit 300 is disposed on the back surface of the liquid crystal display panel module 400.
[0048]
The backlight unit 300 is a so-called direct type. A plurality of (eight in the figure) cold cathode ray tubes 35 extending in the x direction and arranged in the y direction in the figure, and the cold cathode ray tubes 35. And a reflection plate 36 for irradiating light from the liquid crystal display panel module 400 side.
[0049]
As shown in detail in FIG. 7, the reflector 36 is formed in a wave shape in the direction in which the cold cathode ray tubes are juxtaposed (y direction). In other words, each cold cathode ray tube has an arcuate concave portion where the cold cathode ray tube is disposed, and has a shape having a sharp convex portion between the cold cathode ray tubes, and all of the light from each cold cathode ray tube is displayed on the liquid crystal display. It has an efficient shape to irradiate the panel module side.
[0050]
In this case, the reflecting plate 36 is provided with a side surface 37 on a side orthogonal to the longitudinal direction of the cold cathode ray tube, and both ends of the cold cathode ray tube are fitted into slits 38 formed on the side surface 37 so that the cold cathode ray tube is aligned. Movement in the installation direction is restricted.
[0051]
(Resin frame)
The resin frame 500 constitutes a part of the outer frame of the modularized liquid crystal display device, and accommodates the backlight unit 300.
[0052]
Here, the resin frame 500 has a box shape having a bottom surface and a side surface, and an upper end surface of the side surface can mount a diffusion plate 600 disposed so as to cover the backlight unit 300.
[0053]
The diffusing plate 600 has a function of diffusing light from each cold cathode ray tube 35 of the backlight unit 300, and thereby, the liquid crystal display panel module 400 can be irradiated with uniform light with no brightness bias. It can be done.
[0054]
In this case, the resin frame 500 is formed with a relatively small thickness. This is because the reduction in mechanical strength can be reinforced by the middle frame 700 described later.
[0055]
A DC / AC inverter board 40 is attached to the back surface of the resin frame 500.
[0056]
The DC / AC inverter board 40 is for supplying power to each cold cathode ray tube 35 of the backlight unit 300, and the connection from the DC / AC inverter board 40 is connected to terminals at both ends of each cold cathode ray tube. It is like that.
[0057]
[Medium frame]
An intermediate frame 700 is disposed between the liquid crystal display panel module 400 and the diffusion plate 600.
[0058]
The middle frame 700 is formed of a relatively thin metal plate having an opening 42 formed in a portion corresponding to the display area of the liquid crystal display panel module 400.
[0059]
The middle frame 700 has a function of pressing the diffusion plate 600 against the resin frame 500 and a function of placing the liquid crystal display panel module 400.
[0060]
Therefore, a positioning spacer 44 made of, for example, an L-shaped resin material is attached to a portion corresponding to the corner of the liquid crystal display panel 100 of the middle frame 700 on which the liquid crystal display panel module 400 is placed. As a result, the liquid crystal display panel 100 can be accurately positioned with respect to the middle frame 700.
[0061]
As shown in detail in FIG. 8, the middle frame 700 has a shape in which side surfaces 46 are integrally formed. In other words, the opening 42 is formed on the bottom surface of a metal plate having a box shape. It has a formed shape.
[0062]
The intermediate frame 700 having such a shape is fitted to the resin frame 500 with the diffusion plate 600 disposed therebetween. In other words, the middle frame 700 is stacked on the resin frame 500 so that the inner wall of the side surface 46 faces the outer wall of the side surface of the resin frame 500.
[0063]
The middle frame 700 of the metal plate configured in this way constitutes one frame together with the resin frame 500, and improves its mechanical strength without increasing the thickness of the resin frame 500. Will be able to.
[0064]
That is, each of the middle frame 700 and the resin frame 500 is improved in mechanical strength by being fitted as described above even if the mechanical strength is not sufficient. It has strength against twisting around.
[0065]
For this reason, there exists an effect which can ensure sufficient intensity | strength, without enlarging what is called a frame in the module of a liquid crystal display device.
[0066]
Further, the middle frame 700 itself has an effect that the mechanical strength is increased and the handling in the previous stage of the assembly of the module is facilitated as compared with a substantially planar one having no side surface.
[0067]
In this embodiment, the control board 33 and the DC / DC converter board 47 are arranged to face each other on a part of the side face 46 of the middle frame 700. In other words, the frame is arranged perpendicular to the liquid crystal display panel module 400, thereby reducing the frame.
[0068]
In this case, the control substrate 33 is connected to the flexible gate substrate 30 and the drain substrate 31 attached to the liquid crystal display panel module 400, and is arranged as described above by bending the drain substrate 31.
[0069]
The control board 33 and the DC / DC converter board 47 correspond to a portion surrounded by a one-dot chain line frame Q in FIG.
[0070]
By doing so, it goes without saying that the influence of the electromagnetic wave generated from the control board 33 on other members can be avoided by the side face 46 of the middle frame 700.
[0071]
In the above-described embodiment, the box shape is described as the shape of the middle frame 700. However, it is not necessary to be a complete box shape, and at least one side surface may be formed.
[0072]
This is because such an intermediate frame 700 is not planar, but has a bent portion, and thereby has a structure in which mechanical strength is improved.
[0073]
[Upper frame]
The upper frame 800 has a function of pressing the liquid crystal display panel module 400, the middle frame 700, and the diffusion plate 600 toward the resin frame 500, and constitutes an outer frame of the module of the liquid crystal display device together with the resin frame 500. It is supposed to be.
[0074]
The upper frame 800 is formed with an opening (display window) 48 in a portion corresponding to the display area of the liquid crystal display panel module 400 on a metal plate having a substantially box shape, and is locked to the resin frame 500, for example. It can be attached.
[0075]
The upper frame 800 also has a function as a shield material.
[0076]
[Module cross section]
9 is a view showing a cross section taken along line IX-IX in FIG.
[0077]
As is clear from the figure, the middle frame 700 has the function of placing the liquid crystal display panel module 400, and the light from the backlight unit 300 is irradiated only on the display area of the liquid crystal display panel module 400 and its surroundings. It also has a mask function that prevents the part from being irradiated.
[0078]
Therefore, the contour portion of the opening 42 of the middle frame 700 is required to be accurately positioned with respect to the liquid crystal display panel module 400.
[0079]
In the case of the present embodiment, since the thickness of the middle frame 700 is relatively thin as described above, the setting can be performed accurately and it is not necessary to consider the influence of the thickness of the middle frame 700 for the setting. There is an effect.
[0080]
FIG. 10 is a diagram corresponding to FIG. As is apparent from the figure, the function of the mask of the resin frame 500 greatly affects its thickness, and as a result, the function of the mask is sufficiently exerted depending on the position of the contour of the opening 52 of the resin frame 500. In other words, a shadow of light is formed around the display area of the liquid crystal display panel 100 as viewed from the observation side.
[0081]
9 and 10, D is the thickness of the middle frame, δ is the gap between the middle frame 700 made of cushioning material and the transparent substrate 1 A, d is the thickness of the transparent substrate 1 A, and L is the display area from the end of the middle frame. Indicates the distance to. In the conventional liquid crystal display panel, the viewing angle is narrow, and when observing from the oblique direction with respect to the liquid crystal display panel, there is a problem such as a change in gradation as compared with the case of observing in front of the liquid crystal display panel. .
[0082]
In contrast, the inventor of the present application has an excellent wide-angle visual field in the above-described liquid crystal display panel using the lateral electric field method, and therefore the angle around θ shown in FIGS. When observing, the problem that the shadow by the middle frame was conspicuous was found.
[0083]
9 and 10, when considering a light ray that is emitted at an angle θ with respect to the surface of the liquid crystal display panel 100 and passes through the end portion of the display region, a distance L is set so that the light ray and the middle frame 700 do not cross each other. , No shadow is observed within the angle θ. The angle θ is as wide as possible and the distance L is preferably as short as possible. However, when the angle θ is increased, the distance L is increased.
[0084]
Here, when the light path is emitted at an angle θ with respect to the surface of the liquid crystal display panel 100 and the optical path passing through the end of the display region is traced, the total thickness D, gap δ, and thickness d of the transparent substrate 1A described above is obtained. It can be found that the distance L can be shortened even when the angle θ is constant by changing D + δ + d. In the case of the present embodiment, by using the metal middle frame 700, the thickness D of the middle frame 700 can be reduced and the distance L can be shortened without impairing the strength of the module.
[0085]
Further, according to the liquid crystal display device according to the present embodiment, since the thickness of the middle frame 700 can be reduced, the liquid crystal display panel module 400 is disposed close to the backlight unit 300, as is apparent from FIG. Thus, the display brightness can be improved.
[0086]
Example 2
FIG. 11 is a view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.
[0087]
11, the same reference numerals as those in FIG. 1 are configured by members having the same functions.
[0088]
A configuration different from FIG. 1 is that a deflection preventing plate 50 is disposed on the back surface of the liquid crystal display panel module 400.
[0089]
The deflection preventing plate 50 is made of a transparent substrate made of, for example, acrylic resin.
[0090]
The deflection preventing plate 50 is positioned in the opening 42 of the middle frame 700 and is supported by the resin frame 500 via the diffusion sheets 60A and 60B and the diffusion plate 600.
[0091]
That is, as shown in FIG. 12A, which is a cross-sectional view taken along the line XII-XII in FIG. 11, the diffusion plate 600 is disposed so as to crotch the opening of the resin frame 500, and is mounted on the diffusion plate 600. The liquid crystal display panel module 400 is placed in contact with the placed diffusion sheet 60A.
[0092]
In this case, the deflection preventing plate 50 is positioned in a plane including the opening 42 of the middle frame 700 and is disposed so as to be fitted into the opening 42.
[0093]
As a result, the position of the anti-bending plate 50 in the plane direction is regulated by the middle frame 700, and the position in the vertical direction is regulated by the diffusion plate 600 (including the diffusion sheets 60A and 60B) and the liquid crystal display panel module 400. Therefore, it is not necessary to add a special positioning means for the deflection preventing plate 50.
[0094]
The liquid crystal display device configured as described above is arranged such that the liquid crystal display panel module 400 is in direct contact with the anti-bending plate 50 (or other optical means may be interposed) on the back surface thereof. A force that resists the force of the liquid crystal display panel toward the backlight unit 300 acts on at least the entire display area of the liquid crystal display panel module 400.
[0095]
As described in the above embodiment, this is because the liquid crystal display panel module 400 is not greatly increased in thickness, but the area is drastically increased. The fact that bending tends to occur is solved by the bending preventing plate 50.
[0096]
And since the said bending prevention board 50 is supported by the resin frame 500 used as one of the outer frames of a liquid crystal display device (in the case of an Example, via diffusion sheet 60A, 60B, the diffusion plate 600), If the rigidity is a certain level, the liquid crystal display panel module 400 can be sufficiently prevented from being bent.
[0097]
In the above-described embodiment, the deflection preventing plate 50 is in direct or indirect contact (surface contact) with the liquid crystal display panel module 400 over the entire display area. Of course, it does not have to be.
[0098]
For example, the bending prevention plate 50 may be in contact with several portions of the display area of the liquid crystal display panel module 400. This is because it suffices if a force that resists the force on the backlight unit 300 side of the liquid crystal display panel module 400 acts on the display area of the liquid crystal display panel module 400.
[0099]
FIG. 12B is obtained by changing the shape of the end portion of the deflection preventing plate 50 of FIG. A step is provided at the end of the bending prevention plate 50 so as to enter under the middle frame 700, and the formation region of the bending prevention plate 50 is extended to the support portion of the resin frame 500. By doing so, since it can be supported by the resin frame 500 so as to oppose the force applied to the end portion of the deflection preventing plate 50, deformation of the diffusion plate 600 can be prevented.
[0100]
Example 3
FIGS. 13A and 13B are explanatory views showing a further improved embodiment of the liquid crystal display device shown in the second embodiment.
[0101]
FIG. 13A is a cross-sectional view showing the deflection preventing plate 50 together with the liquid crystal display panel module 400. For example, an ITO film is applied to at least a portion of the deflection preventing plate 50 facing the display region of the liquid crystal display panel module 400. A transparent conductive film 70 is formed.
[0102]
As described above, the liquid crystal display panel module 400 shown in the above embodiment is called a so-called lateral electric field method, and each pixel controls the light transmittance of the liquid crystal by an electric field substantially parallel to the substrate. .
[0103]
In this case, since the electric field is extremely weak and easily affected by an external electric field, the transparent conductive film 70 functions as an antistatic means.
[0104]
In particular, as described above, the liquid crystal display panel module 400 is disposed so as to be in direct or indirect contact with the deflection preventing plate 50, and thus static electricity generated by friction at that time tends to affect the electric field. Therefore, it is extremely effective to provide the antistatic means on the surface of the bending prevention plate 50.
[0105]
For the same purpose, it goes without saying that such antistatic means may be formed on the surface of the liquid crystal display panel module 400 on the side of the deflection preventing plate 50 side.
[0106]
It should be noted that static electricity from the outside is likely to enter the surface on the observation side of the liquid crystal display panel module 400, that is, the surface opposite to the backlight unit 300. Rather, static electricity such as deposition of a transparent conductive film on this surface. Since the display body is not formed unless the preventive measures are taken, the antistatic measures have been conventionally taken.
[0107]
FIG. 13B is a cross-sectional view showing a configuration in which diffusion sheets 60 </ b> A and 60 </ b> B are provided between the deflection preventing plate 50 and the liquid crystal display panel module 400. A transparent conductive film 70 made of, for example, an ITO film is formed on at least a portion of the diffusion sheets 60A and 60B facing the display region, and antistatic treatment is performed. The surfaces of the diffusion sheets 60A and 60B are rough. By providing the diffusion sheets 60A and 60B between the deflection preventing plate 50 and the liquid crystal display panel module 400, the deflection preventing plate 50 and the liquid crystal display panel module 400 are provided. It is possible to prevent problems such as Newton's rings that occur due to the overlap.
[0108]
The surfaces where the deflection preventing plate 50 and the liquid crystal display panel module 400 are in contact with each other are mirror surfaces. Therefore, in order to prevent the deflection preventing plate 50 and the liquid crystal display panel module 400 from sticking in a narrow gap, a liquid crystal display is used. An AG process for roughening and matting the surface of the polarizing plate provided on the surface of the panel module 400 that is in contact with the deflection preventing plate 50 may be performed. Further, the surface of the deflection preventing plate 50 may be roughened.
[0109]
Example 4
FIG. 14 is an explanatory diagram showing a further improved embodiment of the liquid crystal display device shown in the second embodiment.
[0110]
This figure shows a liquid crystal display panel module 400 and a deflection preventing plate 50 formed integrally with the liquid crystal display panel module 400.
[0111]
The deflection preventing plate 50 is fixed in the display area of the liquid crystal display panel module 400.
[0112]
When configured in this way, the number of parts of the module constituting the liquid crystal display device can be reduced, and it is not necessary to pay attention to the positioning of the deflection preventing plate 50 with respect to the liquid crystal display panel module 400 when the module is assembled. .
[0113]
Further, for the same purpose, the bending prevention plate 50 and the diffusion plate 600 may be integrated.
[0114]
For example, the bending prevention plate 50 may be prepared, the surface on the backlight unit 300 side may be subjected to an appropriate process, and this processing surface may have the same function as the diffusion plate 600.
[0115]
Example 5 FIG.
FIG. 14 is a cross-sectional view showing another embodiment of the deflection preventing plate 50.
[0116]
In the figure, a deflection preventing plate 50 is coated with, for example, a metal film 80 that reflects light on its peripheral side end surface, and this metal film 80 has a function of light reflecting means.
[0117]
Moreover, you may provide a white tape and a flexible spacer in a side end surface.
[0118]
The light from the backlight unit 300 is irradiated to the liquid crystal display panel module 400 side through a relatively large deflection preventing plate 50.
[0119]
In this case, the light directed to the side end surface of the deflection preventing plate 50 does not reach the eyes of the observer when the light reflecting means as described above is not provided on the side end surface, and is used as wasted light. Will be used.
[0120]
For this reason, the above-described configuration eliminates the inconvenience, thereby producing an effect of slightly increasing the area of the display region.
[0121]
Further, the white tape or spacer provided on the side end surface is generated between the deflection preventing plate 50 and the middle frame 700 when the deflection preventing plate 50 expands due to heat or the like, or vibrates when the product is conveyed. It is possible to prevent the deflection preventing plate 50 from being deformed by absorbing the pressure. In addition, it is possible to prevent the bending prevention plate 50 from being damaged, and further to prevent generation of dust due to the damage. Further, the white tape or spacer provided on the side end face can prevent foreign matter from entering by filling the gap between the deflection preventing plate 50 and the middle frame 700.
[0122]
The liquid crystal display device described above has been described with respect to a so-called horizontal electric field type, but is not limited to this, and it is needless to say that the present invention can also be applied to a so-called vertical electric field type.
[0123]
This is because the difference is mainly in the configuration of the pixels, and there is almost no difference in the other configurations.
[0124]
Here, the vertical electric field type liquid crystal display device means that a transparent electrode is formed on each surface on the liquid crystal side of each transparent substrate opposed to each other via a liquid crystal, and a voltage difference applied to each of the electrodes. Thus, the light transmittance of the liquid crystal between them is controlled.
[0125]
【The invention's effect】
As is apparent from the above description, according to the liquid crystal display device of the present invention, the strength of the resin frame can be ensured without increasing the so-called frame regardless of the increase in size.
[0126]
In addition, it is possible to obtain a liquid crystal display panel in which no shadow of light is observed around the display area as viewed from the observation side.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of a liquid crystal display device according to the present invention.
FIG. 2 is an equivalent circuit diagram showing an embodiment of a liquid crystal display device according to the present invention.
FIG. 3 is a plan view showing one embodiment of a pixel of a liquid crystal display device according to the present invention.
4 is a cross-sectional view taken along line IV-IV in FIG.
5 is a cross-sectional view taken along line VV in FIG. 3. FIG.
6 is a cross-sectional view taken along line VI-VI in FIG.
FIG. 7 is a perspective view showing an embodiment of a backlight unit of a liquid crystal display device according to the present invention.
FIG. 8 is a perspective view showing an embodiment of a middle frame of a liquid crystal display device according to the present invention.
FIG. 9 is an explanatory diagram showing the effect of the present invention.
FIG. 10 is a diagram corresponding to FIG. 9 and is an explanatory diagram showing the disadvantages of the conventional configuration.
FIG. 11 is an exploded perspective view showing another embodiment of the liquid crystal display device according to the present invention.
12 is a cross-sectional view taken along line XII-XII in FIG.
FIG. 13 is a cross-sectional view showing another embodiment of the liquid crystal display device according to the present invention.
FIG. 14 is a cross-sectional view showing another embodiment of the liquid crystal display device according to the present invention.
FIG. 15 is a cross-sectional view showing another embodiment of the deflection preventing plate used in the liquid crystal display device according to the present invention.
[Explanation of symbols]
50 ... Deflection prevention plate, 100 ... Liquid crystal display panel, 300 ... Backlight unit, 400 ... Liquid crystal display panel module, 500 ... Resin frame, 600 ... Diffuser plate, 700 ... Middle frame, 800 ... ... the upper frame.

Claims (11)

A liquid crystal display panel;
A backlight disposed on the back surface of the liquid crystal display panel,
An upper frame made of a metal plate disposed in front of the liquid crystal display panel and having an opening formed in a portion corresponding to a display area of the liquid crystal display panel ;
A resin frame disposed on the back surface of the liquid crystal display panel and having a bottom surface for accommodating the backlight and a side surface formed on the periphery thereof;
From the liquid crystal display panel and at least one side of the peripheral edge of the inserted and the display frame portion having an opening formed to guide the region and the frame portion of the light from the backlight the liquid crystal display panel between the resin frame A middle frame made of a metal plate having a side wall portion extending along the side wall of the resin frame ,
The upper frame is a liquid crystal fixed to the resin frame with the middle frame and the liquid crystal display panel sequentially stacked on the backlight housed in the resin frame sandwiched with the resin frame. Display device. The liquid crystal display device of the opening formed in the frame-like portion in said frame according to claim 1 which defines the area illuminated by the backlight of the liquid crystal display panel. The liquid crystal display device according to claim 1 , wherein the middle frame receives a back surface of the liquid crystal display panel by the frame-shaped portion . A liquid crystal display panel;
A backlight disposed on the back of the liquid crystal display panel;
An upper frame made of a metal plate disposed in front of the liquid crystal display panel and having an opening formed in a portion corresponding to a display area of the liquid crystal display panel;
A resin frame disposed on the back surface of the liquid crystal display panel and having a bottom surface for accommodating the backlight and a side surface formed on the periphery thereof;
From at least one side of a frame portion inserted between the liquid crystal display panel and the resin frame and having an opening for guiding light from the backlight to the display area of the liquid crystal display panel, and a periphery of the frame portion An intermediate frame made of a metal plate having a side wall portion extending along the side wall of the resin frame;
A transparent substrate positioned in the opening of the middle frame,
The upper frame is a liquid crystal fixed to the resin frame with the middle frame and the liquid crystal display panel sequentially stacked on the backlight housed in the resin frame sandwiched with the resin frame. Display device. The liquid crystal display device according to claim 4 , wherein the transparent substrate is in contact with a back surface of the liquid crystal display panel and supported by the resin frame . The liquid crystal display device according to claim 4, wherein the resin frame is provided with a portion for receiving the transparent substrate . The liquid crystal display device according to claim 4, wherein the transparent substrate is positioned on the same surface as the opening of the middle frame . The liquid crystal display device according to claim 4, wherein an antistatic member is provided between the liquid crystal display panel and the transparent substrate . The liquid crystal display device according to claim 4, wherein a transparent conductive film is provided on a surface of the transparent substrate facing the liquid crystal display panel . The liquid crystal display panel has a structure in which an electric field substantially parallel to one of the substrates is applied to a liquid crystal layer between a pair of substrates constituting the liquid crystal display panel to change a light transmission characteristic of the liquid crystal layer. The liquid crystal display device according to claim 4, wherein an antistatic member is provided on the transparent substrate positioned in the opening . It said sidewall portion in said frame, a liquid crystal display device according to any one of claims 1 to 10 opposite to the side wall outer surface of the resin frame body.

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