Display device

Abstract

The display device comprises: a liquid crystal display panel having a first substrate, a second substrate, a first liquid crystal layer, a first polarizing plate, and a second polarizing plate; a dimming panel having a third substrate, a fourth substrate, a second liquid crystal layer, a third polarizing plate, and a fourth polarizing plate; a first transparent conductive layer disposed on the first substrate; a conductive strip connected to the first transparent conductive layer; and a first metal frame formed of a metal material; wherein the conductive strip is connected to the first metal frame.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Japanese Patent Application No. 2021-122567, filed on July 27, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the present invention relate to display devices. Background Technology

[0004] In recent years, in order to improve the contrast of display devices, a technology has been developed that uses a display panel for dimming in addition to the display panel for image display. Summary of the Invention

[0005] The purpose of this embodiment is to provide a display device capable of suppressing electrostatic charging.

[0006] One embodiment of the display device includes:

[0007] A liquid crystal display panel has a first substrate, a second substrate, a first liquid crystal layer sandwiched between the first substrate and the second substrate, a first polarizing plate and a second polarizing plate;

[0008] A dimming panel having a third substrate, a fourth substrate, a second liquid crystal layer, a third polarizing plate, and a fourth polarizing plate sandwiched between the third substrate and the fourth substrate;

[0009] A first transparent conductive layer is disposed on the first substrate;

[0010] Conductive strip, which is connected to the first transparent conductive layer; and

[0011] The first metal frame is formed of a metallic material;

[0012] The conductive strip is connected to the first metal frame. Attached Figure Description

[0013] Figure 1 It is an exploded perspective view schematically showing the structure of a display device with two display panels.

[0014] Figure 2 This is a cross-sectional view illustrating a schematic example of a display device.

[0015] Figure 3 It is a schematic cross-sectional view showing the stacked structure of the liquid crystal display panel and the dimming panel.

[0016] Figure 4 This is a cross-sectional view showing other structural examples of the display device in the embodiment.

[0017] Figure 5A This is a perspective view showing other structural examples of the display device in the embodiment.

[0018] Figure 5B This is a perspective view showing other structural examples of the display device in the embodiment.

[0019] Figure 6 It is along Figure 5A The cross-sectional view of the display device shown by lines A1-A2.

[0020] Figure 7 It is along Figure 5A The cross-sectional view of the display device shown by lines B1-B2. Detailed Implementation

[0021] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the disclosure is merely an example, and appropriate modifications that can be readily conceived by those skilled in the art while maintaining the spirit of the invention are of course included within the scope of the present invention. Additionally, regarding the accompanying drawings, for the purpose of clearer explanation, there are instances where the width, thickness, shape, etc., of various parts are schematically represented compared to the actual embodiment; however, this is merely an example and does not constitute a limitation on the interpretation of the present invention. Furthermore, in this specification and the various figures, elements identical to those described in previously existing figures are sometimes labeled with the same reference numerals, and detailed descriptions are appropriately omitted.

[0022] Hereinafter, a display device according to one embodiment will be described in detail with reference to the accompanying drawings.

[0023] In this embodiment, the first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but they may also intersect at an angle other than 90 degrees. The direction of the third direction Z toward the tip of the arrow is defined as up or above, and the direction of the third direction Z opposite to the direction of the tip of the arrow is defined as down or below. In addition, the first direction X, the second direction Y, and the third direction Z are sometimes referred to as the X direction, the Y direction, and the Z direction, respectively.

[0024] Furthermore, in the cases of "a second component above the first component" and "a second component below the first component," the second component may be connected to the first component or disposed separately from it. In the latter case, a third component may be sandwiched between the first component and the second component. On the other hand, in the cases of "a second component above the first component" and "a second component below the first component," the second component is connected to the first component.

[0025] Furthermore, there is an observation position for viewing the display device at the tip of the arrow pointing from the third direction to Z. Observing the display device from this observation position towards the XY plane defined by the first direction X and the second direction Y is called a top view. Observing the display device in cross-section on the XZ plane defined by the first direction X and the third direction Z, or on the YZ plane defined by the second direction Y and the third direction Z, is called a cross-sectional view.

[0026] [Implementation Method]

[0027] Figure 1 It is an exploded perspective view schematically showing the structure of a display device with two display panels. Figure 1 The diagram illustrates a three-dimensional space defined by a first direction X, a second direction Y perpendicular to the first direction X, and a third direction Z perpendicular to both the first direction X and the second direction Y.

[0028] like Figure 1 As shown, the display device DSP includes a liquid crystal display panel PNL1, a dimming panel PNL2, and a backlight unit BL. For example... Figure 1 As shown, by arranging a dimming panel PNL2 between the liquid crystal display panel PNL1 and the backlight unit BL, the contrast of the image displayed by the liquid crystal display panel PNL1 can be improved.

[0029] In one example, the liquid crystal display panel PNL1 is rectangular. In the illustrated example, the short side EX of the liquid crystal display panel PNL1 is parallel to the first direction X, and the long side EY of the liquid crystal display panel PNL1 is parallel to the second direction Y. The third direction Z corresponds to the thickness direction of the liquid crystal display panel PNL1. The main surface of the liquid crystal display panel PNL1 is parallel to the XY plane defined by the first direction X and the second direction Y. The liquid crystal display panel PNL1 has a display area DA and a non-display area NDA located outside the display area DA. The non-display area NDA has a terminal area MT for mounting a driver IC and a flexible wiring substrate. Figure 1 In the diagram, the terminal area MT is indicated by a slash.

[0030] The display area DA is the area where the image is displayed, and it has, for example, multiple pixels PX configured in a matrix. (Example: In...) Figure 1 As shown in the enlarged representation, each pixel PX is arranged in an area divided by the scan line G and the signal line S, and has a switching element SW, a pixel electrode PE, a common electrode CE, a liquid crystal layer LC, etc.

[0031] The switching element SW is, for example, a thin-film transistor (TFT) and is electrically connected to the scan line G and the signal line S. The scan line G is electrically connected to the switching element SW of each pixel PX arranged along the first direction X. The signal line S is electrically connected to the switching element SW of each pixel PX arranged along the second direction Y. The pixel electrode PE is electrically connected to the switching element SW. The pixel electrode PE is opposite to the common electrode CE, and the liquid crystal layer LC is driven by the electric field generated between the pixel electrode PE and the common electrode CE. The capacitor CS is formed, for example, between an electrode at the same potential as the common electrode CE and an electrode at the same potential as the pixel electrode PE.

[0032] The terminal region MT extends along the short side EX of the liquid crystal display panel PNL1. A terminal portion is formed in the terminal region MT, through which the liquid crystal display panel PNL1 is electrically connected to an external device such as a flexible wiring board.

[0033] The dimming panel PNL2 has a structure that is basically the same as that of the liquid crystal display panel PNL1, but... Figure 1 Detailed structural diagrams are omitted here. Furthermore, the detailed structures of the liquid crystal display panel PNL1 and the dimming panel PNL2 will be explained later. Figure 2 and Figure 3 The descriptions will be presented together.

[0034] The backlight unit BL is located on the lower side of the dimming panel PNL2, and the image is displayed by controlling the light from the backlight unit BL according to each pixel PX.

[0035] Figure 2 This is a cross-sectional view illustrating a schematic example of a display device. Figure 2 The display device DSP shown includes a liquid crystal display panel PNL1, a dimming panel PNL2, an adhesive layer OCA, a resin frame FLR, a frame FLM, an upper frame UFL1, an upper frame UFL2, and a conductive strip CTP. Although not shown, an illumination device, i.e., a backlight, is provided between the resin frame FLR and the dimming panel PNL2. The specific structure of the backlight will be discussed later. Figure 6 The structures are identical. The resin frame FLR and the frame FLM constitute the lower frame DFL.

[0036] The upper frames UFL1 and UFL2 appear to be separate in the attached diagram, but they are actually connected, forming a single frame. Both upper frames UFL1 and UFL2 are made of metal and are therefore referred to as the metal frame.

[0037] The liquid crystal display panel PNL1 includes a first substrate SUB11, a second substrate SUB21, a transparent conductive layer TE1, a first polarizing plate PL11, a second polarizing plate PL21, a flexible printed circuit FPC1, and a printed substrate PC1.

[0038] The dimming panel PNL2 comprises a first substrate SUB12, a second substrate SUB22, a transparent conductive layer TE2, a first polarizing plate PL12, a second polarizing plate PL22, a flexible printed circuit FPC2, and a printed substrate PC2.

[0039] The flexible printed circuit FPC1 is connected to the terminal portion of the first substrate SUB11. A printed substrate PC1 is grounded on the flexible printed circuit FPC1.

[0040] The flexible printed circuit FPC2 is connected to the terminal portion of the first substrate SUB12. A printed substrate PC2 is grounded on the flexible printed circuit FPC2.

[0041] A flexible printed circuit (FPC3) is also grounded to printed circuit substrates PC1 and PC2. A wiring board (TC) is connected to the FPC3. Synchronization signals from the wiring board (TC) are input to printed circuit substrates PC1 and PC2 via the FPC3. Signals are input from printed circuit substrate PC1 to liquid crystal display panel PNL1 via the FPC1. Signals are input from printed circuit substrate PC2 to dimming panel PNL2 via the FPC2. These signals drive liquid crystal display panel PNL1 and dimming panel PNL2, respectively.

[0042] The resin frame FLR has a bottom frame (BFR) and wall frames (WFR). The bottom frame (BFR) has a rectangular shape that extends along the XY plane. The wall frames (WFR) protrude from the end of the bottom frame (BFR) along a third direction (Z).

[0043] The frame FLM has a bottom BFM and a wall WFM. The bottom BFM has a rectangular shape that extends along the XY plane. The wall WFM protrudes from the end of the bottom BFM along a third direction Z.

[0044] The resin frame FLR is disposed within the space formed by the bottom BFR and wall WFR of the frame FLM. The bottom BFR of the resin frame FLR is connected to the bottom BFM of the frame FLM. The wall WFR of the resin frame FLR is connected to the wall WFM of the frame FLM. The frame FLM is made of metal and is also called a metal frame.

[0045] A raised portion (PP) is provided on the surface of the bottom BFM of the frame FLM that is not in contact with the resin frame FLR. The wiring board TC is grounded to the raised portion (PP).

[0046] Figure 3This is a schematic cross-sectional view illustrating the stacked structure of the liquid crystal display panel and the dimming panel. As described above, the display device DSP includes a liquid crystal display panel PNL1 and a dimming panel PNL2. The liquid crystal display panel PNL1 and the dimming panel PNL2 are bonded together, for example, by a transparent adhesive layer OCA. Furthermore, common structures in the liquid crystal display panel PNL1 and the dimming panel PNL2 are positioned so that they overlap when viewed from above, and are bonded together by the adhesive layer OCA.

[0047] The following is a detailed description of the structure of the liquid crystal display panel PNL1.

[0048] like Figure 3 As shown, the liquid crystal display panel PNL1 includes a first substrate SUB11, a second substrate SUB21, a liquid crystal layer LC1, a transparent conductive layer TE1, a first polarizing plate PL11, and a second polarizing plate PL21.

[0049] The liquid crystal layer LC1 is sandwiched between the first substrate SUB11 and the second substrate SUB21 and sealed by the sealing member SE1. The first polarizing plate PL11 is disposed below the first substrate SUB11, and the second polarizing plate PL21 is disposed above the second substrate SUB21. The polarization axis of the first polarizing plate PL11 and the polarization axis of the second polarizing plate PL21 are, for example, orthogonal to each other, that is, at a 90-degree angle.

[0050] A transparent conductive layer TE1 is provided between the second substrate SUB21 and the second polarizing plate PL21, grounded to the second substrate SUB21. By providing the transparent conductive layer TE1, static electricity can be prevented from charging the liquid crystal display panel PNL1. Details are described later.

[0051] A flexible wiring board FPC1 is mounted on the terminal area MT1 of the liquid crystal display panel PNL1.

[0052] Next, the detailed structure of the dimming panel PNL2 will be explained.

[0053] like Figure 3 As shown, the dimming panel PNL2 is the same as the liquid crystal display panel PNL1, and includes a first substrate SUB12, a second substrate SUB22, a liquid crystal layer LC2, a transparent conductive layer TE2, a first polarizing plate PL12, and a second polarizing plate PL22.

[0054] The liquid crystal layer LC2 is sandwiched between the first substrate SUB12 and the second substrate SUB22 and sealed by the sealing member SE2. A first polarizing plate PL12 is disposed below the first substrate SUB12, and a second polarizing plate PL22 is disposed above the second substrate SUB22. The polarization axis of the first polarizing plate PL12 and the polarization axis of the second polarizing plate PL22 are, for example, orthogonal to Nicol's law, i.e., at 90 degrees. Furthermore, the polarization axis of the first polarizing plate PL11 of the liquid crystal display panel PNL1 and the polarization axis of the second polarizing plate PL22 of the dimming panel PNL2 are aligned in the same direction.

[0055] A transparent conductive layer TE2 is provided between the second substrate SUB22 and the second polarizing plate PL22, grounded to the second substrate SUB22. Details of the transparent conductive layer TE2 will be described later.

[0056] A flexible wiring board FPC2 is mounted on the terminal area MT2 of the dimming panel PNL2.

[0057] Back Figure 2 This section details the countermeasures for static electricity (ESO) in the liquid crystal display panel PNL1 and the dimming panel PNL2. In the liquid crystal display panel PNL1, a conductive strip CTP is connected to the transparent conductive layer TE1. The conductive strip CTP is connected to the frame FLM and the upper frame UFL1. In other words, the transparent conductive layer TE1 is electrically connected to the frame FLM and the upper frame UFL1 via the conductive strip CTP. Since the frame FLM and the upper frame UFL1 are made of metal, even if the liquid crystal display panel PNL1 carries static electricity, the static electricity will be discharged to the frame FLM and the upper frame UFL1 via the conductive strip CTP. Furthermore, as long as the conductive strip CTP is at least connected to the frame FLM, ESO can be achieved.

[0058] On the other hand, a transparent conductive layer TE2 is provided in the dimming panel PNL2. The transparent conductive layer TE2 is not electrically connected to the frame FLM and the upper frame UFL1. The transparent conductive layer TE2 is in an electrically floating state.

[0059] The static electricity carried by the display device's DSP is generated when the polarizing plate is attached to the panel and when the protective film on which the polarizing plate is attached is peeled off. The dimming panel PNL2 is attached to the liquid crystal display panel PNL1 via the adhesive layer OCA while the polarizing plate is attached. Therefore, the dimming panel PNL2 does not carry static electricity. Thus, the transparent conductive layer TE2 can be in an electrically floating state.

[0060] On the dimming panel PNL2, there is no need to attach conductive strips that connect to the transparent conductive layer TE2. This reduces the number of manufacturing steps and the manufacturing cost of the display device's DSP.

[0061] In this embodiment, by connecting the transparent conductive layer TE1 disposed on the liquid crystal display panel PNL1 and the frame FLM, a display device capable of suppressing electrostatic charging can be provided.

[0062] <Structure Example 1>

[0063] Figure 4 This is a cross-sectional view showing other structural examples of the display device in the embodiment. Figure 4 In the structural example shown, with Figure 2 The difference between the structure shown and the one shown is that a transparent conductive layer is not provided for the dimming panel PNL2.

[0064] exist Figure 4 In the DSP display device shown, no transparent conductive layer is provided between the second substrate SUB22 and the second polarizing plate PL22 of the dimming panel PNL2. Figure 4 The other structures of the DSP in the display device shown are similar to those in the previous diagram. Figure 2 The same applies, therefore please cite for details. Figure 2 The explanation is omitted here.

[0065] As described above, no static electricity will be generated on the dimming panel PNL2 when the liquid crystal display panel PNL1 is bonded. Therefore, even if a transparent conductive layer is not provided on the dimming panel PNL2, as long as the liquid crystal display panel PNL1 has a transparent conductive layer TE1, static electricity can be suppressed.

[0066] In this structural example, it also achieves the same effect as in the implementation method.

[0067] <Structure Example 2>

[0068] Figure 5A and Figure 5B This is a perspective view showing other structural examples of the display device in the embodiment. In this structural example, the detailed structure of the conductive strip and its surrounding area will be described.

[0069] Figure 5A This is a 3D view of a portion of the display device's DSP. Figure 5A The image shows the flat portion UFL1a and the wall portion UFL1b, which are part of the upper frame UFL, as well as the second substrate SUB12 and the second polarizing plate PL21 of the liquid crystal display panel PNL1. The flat portion UFL1a and the wall portion UFL1b are formed of plate-shaped metal materials extending along the XY plane and the XZ plane, respectively.

[0070] The flat portion UFL1a has a recess CAV and a notch NTC1. The wall portion UFL1b has a notch NTC2. Inside the notch NTC2, a fastener SCR, which will be fitted into the frame FLM as described later, is disposed.

[0071] Figure 5B yes Figure 5A A magnified view of a portion of the image. Furthermore, in... Figure 5B In the accompanying drawings, for ease of observation, some of the components of the display device DSP are omitted. For example, the upper frame UFL (flat portion UFL1a and wall portion UFL1b) is omitted.

[0072] A conductive strip CTP is provided for grounding the liquid crystal display panel PNL1. The conductive strip CTP has a first part CTPa, a second part CTPb, a third part CTPc, and a fourth part CTPd.

[0073] The first part CTPa, the second part CTPb, the third part CTPc, and the fourth part CTPd are respectively arranged along the XY plane, XZ plane, XY plane, and XZ plane. The first part CTPa is connected to the transparent conductive layer (not shown) of the liquid crystal display panel PNL1. Details of these parts are described later.

[0074] The first part of the resin frame FLR2, FLR2a, has a notch NTC3. Inside the notch NTC3, the wall portion FLMa1 of the frame FLM and the fastener SCR are disposed. The fastener SCR fixes the upper frame UFL, the frame FLM, and the resin frame FLR2. Details of the wall portion FLMa1 will be described later.

[0075] Figure 6 It is along Figure 5A The cross-sectional view of the display device shown by lines A1-A2.

[0076] like Figure 6 As shown, the display device DSP includes a frame FLM, a resin frame FLR1, an illumination device ILD, a dimming panel PNL2, a liquid crystal display panel PNL1, an adhesive layer OCA, a light source element LS, a wiring substrate DLS, an adhesive tape ATP, the frame FLM, the resin frame FLR2, the flat portion UFL1a and the wall portion UFL1b of the upper frame UFL1, and a conductive tape CTP. The illumination device ILD and... Figure 1 The backlight unit BL is the same.

[0077] The frame FLM has a bottom FLMb, wall portions FLMa1 and FLMa2, and a flat portion FLMf. The bottom FLMb extends along the XY plane. Wall portions FLMa1 and FLMa2 extend and protrude from the ends of the bottom FLMb along the XZ plane. The flat portion FLMf extends from the ends of wall portion FLMa2 along the XY plane.

[0078] A resin frame FR1 is provided in contact with the bottom FLMb of the frame FLM. The resin frame FR1 has a bottom FR1b and multiple protrusions FR1a. The protrusions FR1a are in contact with and support the lighting device ILD.

[0079] The lighting device ILD includes a reflector REF, a light guide plate LG, an optical plate OPS, a light source element LS, and a wiring substrate DLS. The reflector REF, light guide plate LG, and optical plate OPS are arranged in this order along the third direction Z. The light source element LS is arranged side-by-side with the light guide plate LG. The light source element LS is connected to the wiring substrate DLS. The wiring substrate DLS is bonded to the wall FLMa1 of the frame FLM using adhesive tape ATP.

[0080] Optical sheets (OPS) can be, for example, prism sheets or diffusers. Moreover, for example, as an optical sheet (OPS), only two prism sheets and one diffuser are required.

[0081] The resin frame FLR2 has a first portion FLR2a, a second portion FLR2b, and a third portion FLR2c extending along the XZ plane, XY plane, and XZ plane, respectively. As described above, the first portion FLR2a is grounded to the second portion CTPb of the conductive strip CTP. Because the resin frame FLR2 has a notch NTC3, the first portion FLR2a is partially connected to the wall portion FLMa1 of the frame FLM, but not completely. The second portion FLR2b holds the wall portion FLMa1 of the frame FLM. The third portion FLR2c has a fixing member AD that connects to the first polarizing plate PL12. The dimming panel PNL2, which includes the first polarizing plate PL12, is fixed by the third portion FLR2c and the fixing member AD.

[0082] The first part CTPa of the conductive strip CTP is pressed and fixed to the liquid crystal display panel PNL1 by the recess CAV of the upper frame UFL1.

[0083] The second part, CTPb, is fixed between the wall portion UFL1b of the upper frame UFL1 and the first part FLR2a of the resin frame FLR2 via the wall portion UFL1b. The fourth part, CTPd, is connected to the wall portion FLMa1 of the frame FLM.

[0084] As described above, the first portion CTPa of the conductive strip CTP is connected to the transparent conductive layer of the liquid crystal display panel PNL1, and the fourth portion CTPd is connected to the wall portion FLMa1 of the frame FLM. Thus, the static electricity carried by the liquid crystal display panel PNL1 is discharged to the frame FLM via the conductive strip CTP.

[0085] In addition, the conductive strip CTP is fixed by the recess CAV of the upper frame UFL1 and the wall UFL1b, so it will not cause positional displacement.

[0086] Figure 7 It is along Figure 5A A cross-sectional view of the display device shown along lines B1-B2. For Figure 7 Only for Figure 6 The differences between them will be explained.

[0087] exist Figure 7 In the middle, because it is separated from the notch NTC3, the first part FLR2a of the resin frame FLR2 is in contact with the entire wall FLMa1 of the frame FLM.

[0088] Since the recessed portion CAV and the notched portion NTC1 of the upper frame UFL1 are separate, the flat portion UFL1a is formed by a flat metal plate extending along the XY plane.

[0089] In this structural example, it also achieves the same effect as in the implementation method.

[0090] In this disclosure, the frame FLM is also referred to as the first metal frame, and the upper frame UFL is also referred to as the second metal frame.

[0091] The first substrate SUB12 and the second substrate SUB22 of the dimming panel PNL2 are also referred to as the third substrate and the fourth substrate, respectively. The first polarizing plate PL12 and the second polarizing plate PL22 are also referred to as the third polarizing plate and the fourth polarizing plate, respectively.

[0092] The transparent conductive layers TE1 and TE2 are also referred to as the first transparent conductive layer and the second transparent conductive layer, respectively.

[0093] Some embodiments of the present invention have been described, but these embodiments are provided by way of example and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

Claims

1. A display device, characterized in that, have: A liquid crystal display panel has a first substrate, a second substrate, a first liquid crystal layer sandwiched between the first substrate and the second substrate, a first polarizing plate and a second polarizing plate; A dimming panel having a third substrate, a fourth substrate, a second liquid crystal layer, a third polarizing plate, and a fourth polarizing plate sandwiched between the third substrate and the fourth substrate; A first transparent conductive layer is disposed on the first substrate; A conductive strip, which is connected to the first transparent conductive layer; A first metal frame, formed of metallic material, constitutes the lower frame; and The second metal frame, which serves as the upper frame, is formed of metallic material. The conductive strip is connected to the first metal frame. The liquid crystal display panel is disposed between the first metal frame and the dimming panel. The second metal frame has a recess. The conductive strip is fixed by the recess.

2. The display device according to claim 1, characterized in that, The display device further includes a second transparent conductive layer disposed on the third substrate. The second transparent conductive layer is in an electrically floating state.

3. The display device according to claim 1, characterized in that, The liquid crystal display panel is disposed between the first metal frame and the dimming panel.

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