Display device and liquid crystal display device

Abstract

The present invention addresses the problem of using a plurality of display devices to seamlessly form a large screen. To solve said problem, the present invention has the following configuration. That is, the display devices are characterized in that: a first display device 1000 has a first display area 10 and a first frame edge area 20 disposed outside the first display area 10; a second display device 2000 has a second display area 10 and a second frame edge area 20 disposed outside the second display area 10; the first display device 1000 and the second display device 2000 are disposed in parallel in a state of partially overlapping each other; the first frame edge area 20 of the first display device 1000 overlaps the second display area 10 of the second display device 2000; the second frame edge area 20 of the second display device 2000 overlaps the first display area 10 of the first display device 1000; and when viewed in a plan view, the first display area 10 and the second display area 10 are continuous to each other.

Description

Technical Field

[0001] The present invention relates to a display device, and particularly to a transparent display device using a liquid crystal display device.

Background Art

[0002] There is a demand for a transparent display device that allows the background to be seen, such as glass. In a transparent display device, for example, an image displayed on the front side can be visually recognized in a state where it is superimposed on the background on the back side. Also, even in a portion where no image is displayed, the background image can be visually recognized through the glass. Such a transparent display device can be realized, for example, using a liquid crystal display device.

[0003] Patent Documents 1 to 3 describe configurations for realizing a transparent liquid crystal display device using so-called polymer-dispersed liquid crystal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a transparent liquid crystal display device or the like, a problem of luminance gradient easily occurs, so it is difficult to increase the size of the screen. When increasing the size of the screen, a means of arranging a plurality of transparent display devices in parallel can be taken. However, in a liquid crystal display device, a frame area for arranging the scanning line lead-out lines is required. Due to the existence of this frame area, the screen is interrupted, so it is difficult to display a natural image simply by arranging a plurality of transparent liquid crystal display devices side by side.

[0006] An object of the present invention is, when realizing a large-screen transparent display device using a plurality of transparent liquid crystal display devices, to realize a natural large screen without the screen being interrupted. Further, it is to realize a transparent liquid crystal display device with little brightness unevenness.

Means for Solving the Problems

[0007] The present invention realizes the above object, and typical means are as follows.

[0008] (1) The first display device has a first display area and a first frame area arranged outside the first display area. The second display device has a second display area and a second frame area arranged outside the second display area. The first display device and the second display device are arranged in parallel with a part overlapping each other. The first frame area of the first display device overlaps the second display area of the second display device, and the second frame area of the second display device overlaps the first display area of the first display device. When viewed in a plane, the first display area and the second display area are continuous. A display device characterized by this.

[0009] (2) A first liquid crystal display device in which a first TFT substrate and a first counter substrate are adhered by a first sealing material in a first frame area, and a first liquid crystal is sandwiched inside, and a first display area is formed in the area where the first liquid crystal is sandwiched, and a second liquid crystal display device in which a second TFT substrate and a second counter substrate are adhered by a second sealing material in a second frame area, and a second liquid crystal is sandwiched inside, and a second display area is formed in the area where the second liquid crystal is sandwiched, are arranged in parallel with a part overlapping each other. The first frame area of the first liquid crystal display device overlaps the second display area of the second liquid crystal display device, and the second frame area of the second display device overlaps the first display area of the first display device. When viewed in a plane, the first display area and the second display area are continuous. A liquid crystal display device characterized by this.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] Hereinafter, the content of the present invention will be described in detail using examples.

Examples

[0012] FIG. 1 is a front view of a transparent liquid crystal display device, and FIG. 2 is a side view. In FIGS. 1 and 2, there is no backlight on the back surface of the display area, and the substrate is made of transparent glass. Therefore, normally light can pass through, and the background on the back side of the transparent liquid crystal display device can be viewed, and the background on the front side can also be viewed from the back side.

[0013] The transparent liquid crystal display device shown in FIGS. 1 and 2 has a single display panel 1000. However, as will be described later, the operations described below are the same even when a large-screen transparent liquid crystal display device is configured by juxtaposing two or more liquid crystal display panels.

[0014] Light sources 40 such as side lights, driver ICs 51, 52, etc. are arranged inside the lower pedestal 5000. Since the display panel 1000 is transparent, like a glass window, it is possible to view the opposite side of the display panel. Also, the image displayed on the display panel 1000 can be viewed from either the back side or the front side. Therefore, the image displayed on the transparent liquid crystal display device can give the impression of floating in the background.

[0015] Figures 1 and 2 show usage examples of the transparent liquid crystal display device, and the transparent liquid crystal display device can be used for various other applications. For example, by attaching it to a window glass, it is usually used as a window glass and can be used to display an image on the window when necessary. Also, when used as a display device for an automobile, it is usually used as a window through which the outside can be seen, and an image can be displayed in the display area as needed.

[0016] Figure 3 is a cross-sectional view showing the operation of the transparent liquid crystal display device. In Figure 3, a liquid crystal 300 is sandwiched between a TFT substrate 100 on which a pixel electrode, a scanning line, a video signal line, a TFT (Thin Film Transistor), etc. are arranged, and a counter substrate 200 on which a common electrode, a black matrix, etc. are formed. A cover glass 400 is arranged on the counter substrate 200. On the surface of the cover glass 400, a surface treatment is performed to prevent fingerprints, etc. from adhering when touched with a finger. This surface treatment is sometimes called an AF (Anti-Finger) treatment.

[0017] The counter substrate 200 and the cover glass 400 are adhered by an OCA (Optical Celar Adhesive) 70. The OCA 70 is a transparent adhesive sheet and has a refractive index close to that of glass. Therefore, the interface reflection between the OCA 70 and the counter substrate 200 or the cover glass 400 can be minimized. The thickness of the OCA 70 is, for example, 0.1 mm. Also, instead of the OCA, it may be bonded with a transparent resin such as an OCR (Optical Clear Resin).

[0018] Since the liquid crystal display device in FIG. 3 is driven in a so-called field sequential manner, there is no color filter. Since no color filter is used, the light transmittance of the display area can be increased. A display area is formed in the overlapping portion of the TFT substrate 100 and the counter substrate 200, and in the TFT substrate 100, a terminal area 30 is formed in the portion that does not overlap the counter substrate 200.

[0019] In FIG. 3, the TFT substrate 100 and the counter substrate 200 are adhered with a transparent sealing material 60, and liquid crystal 300 is encapsulated inside. The liquid crystal 300 in FIG. 3 is a so-called polymer dispersed liquid crystal. The liquid crystal constituting the liquid crystal layer 300 usually transmits light, but when a voltage is applied between the pixel electrode formed on the TFT substrate 100 and the common electrode formed on the counter substrate 200, the orientation of the liquid crystal molecules 301 changes and scatters light. By controlling the scattering action of the liquid crystal molecules 301 for each pixel, an image can be formed. This image can be viewed from both the front and the back of the liquid crystal display panel.

[0020] In FIG. 3, the TFT substrate 100 is formed larger than the counter substrate 200, and the non-overlapping portion of the TFT substrate 100 and the counter substrate 200 is the terminal area 30. The light source 40 is provided on the terminal area 30 so as to face the side surface of the counter substrate 200 or the side surface of the cover glass 400. As shown in FIG. 4, the light source 40 is composed of an LED 41 and a lens 42.

[0021] As shown in FIG. 4, the light source 40 has a configuration in which a plurality of LEDs are arranged on the side surface of the lens 41. The light emitted from the LED 41 is subjected to the action of convergence or divergence by the lens 42, and as shown in FIG. 3, it enters the display area of the transparent liquid crystal display device from the side surface of the counter substrate 200 or the cover glass 400.

[0022] For example, the LED 41 has three LED chips that generate red, green, and blue light, respectively, arranged for each package. Also, the LED 41 may be provided with an LED chip that generates any one of red, green, and blue light for each package, and different colored LEDs 41 may be arranged side by side. The liquid crystal display device in FIG. 3 is driven in a field sequential manner. That is, a color image is displayed by displaying a red image, a green image, and a blue image in a time-division manner. In the following drawings, the light source 40 is shown as being integrated with the LED 41 and the lens 42.

[0023] Returning to FIG. 3, the light from the light source 40 enters the inside of the liquid crystal display panel through the side surface of the counter substrate 200, the side surface of the cover glass, or the sealing material 60. The incident light collides with the liquid crystal molecules 301 in the liquid crystal layer 300 while repeating reflections. Among the liquid crystal molecules 301 in the pixels where a voltage is applied between the pixel electrode and the common electrode, they scatter as shown in FIG. 3. On the other hand, in the pixels where no voltage is applied between the pixel electrode and the common electrode, the light travels straight. As a result, the light incident on the liquid crystal layer 300 is controlled for scattering for each pixel, and thus an image is formed.

[0024] In FIG. 3, a reflector 350 is attached to the side surfaces of the TFT substrate 100, the counter substrate 200, and the cover glass 400 on the side opposite to the light source 40, and reflects the light that reaches the end portion toward the display region side. Note that, in FIGS. 5 and below, the description of the reflector 350 is omitted. In FIG. 3, in the terminal region 30, driver ICs 51 and 52 are arranged side by side with the light source 40.

[0025] FIG. 5 is a perspective view of the transmissive liquid crystal display device used in the present invention. In FIG. 5, the TFT substrate 100 and the counter substrate 200 are arranged overlapping each other. As shown in FIG. 3, liquid crystal is sandwiched between the TFT substrate 100 and the counter substrate 200. On the counter substrate 200, a transparent first cover glass 400 made of glass is attached as a light guide plate for mechanically protecting and guiding the light emitted from the light source 40. The thicknesses of the TFT substrate 100, the counter substrate 200, and the cover glass 400 are, for example, 0.5 mm or 0.7 mm.

[0026] In FIG. 5, a display area 10 is formed in the overlapping portion of the TFT substrate 100 and the counter substrate 200, and the periphery of the display area 10 is a frame area 20. Scanning line leads and the like are arranged in the frame area 20. The feature of the liquid crystal display panel shown in FIG. 5 is that the light source 40 is arranged over the entire side surface of the counter substrate 200 and the cover glass 400 along the terminal area 30. That is, light from the light source 40 also enters the portion corresponding to the frame area 20 where the pixel electrodes are not formed. Thereby, uneven brightness in the display area 10 can be suppressed.

[0027] In FIG. 5, in addition to the light source 40, driver ICs 51 and 52 are arranged in the terminal area 30. A driver IC 51 for video signals is arranged in the central portion of the terminal area 30, and driver ICs 52 for scanning signals are arranged on both sides thereof. A flexible wiring board for supplying signals and power is connected to the terminal area 30, but is omitted in FIG. 5.

[0028] In a transparent liquid crystal display device as shown in FIGS. 3 to 5, when trying to increase the screen size, uneven brightness of the screen becomes a problem. Therefore, in order to obtain a large-screen transparent liquid crystal display device, it is conceivable to juxtapose a plurality of transparent liquid crystal display devices. FIG. 6 shows an example thereof. In FIG. 6, two transparent liquid crystal display devices 1000 and 2000 are arranged in parallel. In FIG. 6, one image is formed by the two display areas 10. However, in the configuration of FIG. 6, since the screen is divided by the frame area 20 over a width w1, a sense of incongruity occurs in the display screen.

[0029] FIG. 7 is a front view showing a configuration in which, in order to counter this, the width of the frame area 20 is reduced and the break in the screen is made as small as w2. In a transparent liquid crystal display device, scanning line leads are formed in the frame area 20. When the width of the frame area 20 is reduced, the density of the scanning line leads increases, and as shown by the shading in FIG. 7, the light transmittance in the frame area 20 decreases, deteriorating the quality as a transparent display device.

[0030] That is, in order to obtain a transparent display device, it is desirable that both the display area 10 and the frame area 20 have the same light transmittance. In the frame area 20, the wiring density of the lead wires has a great influence on the light transmittance. In order to set the wiring density to a predetermined value, the frame area 20 needs to have a predetermined width.

[0031] FIG. 8 is a cross-sectional view showing a basic configuration of the present invention that overcomes the above problems. In FIG. 8, the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 are arranged in such a manner that the frame area 20 and the display area 10 overlap. According to the configuration as shown in FIG. 8, the display area AA1 of the first transparent liquid crystal display device 1000 and the display area AA2 of the second transparent liquid crystal display device 2000 can be seamlessly connected.

[0032] That is, the frame area 20 of the first transparent liquid crystal display device 1000 overlaps with the display area 10 of the second transparent liquid crystal display device 2000, and the frame area 20 of the second transparent liquid crystal display device 2000 overlaps with the display area 10 of the first transparent liquid crystal display device. The first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 are adhered by an OCA 70 in the vicinity of the frame area 20. In FIG. 8, the frame area 20 is shaded for easy understanding in the drawing, but the frame area 20 is also transparent like the display area 10.

[0033] FIG. 9 is a perspective view specifically showing the configuration of FIG. 8. In FIG. 9, the second transparent liquid crystal display device 2000 is arranged upside down with respect to the first transparent liquid crystal display device 1000, and the display areas 10 and the frame areas 20 of each other overlap. The back side of the TFT substrate 100 of the first transparent liquid crystal display device 1000 and the back side of the TFT substrate 100 of the second transparent liquid crystal display device 2000 are adhered via an OCA in the frame area portion 20. Since the same image is displayed on each of the transparent liquid crystal display devices 1000 and 2000 shown in FIG. 9 when viewed from the front or the back, there is no problem with the visibility of the entire transparent liquid crystal display device.

[0034] FIG. 10 is a plan view of FIG. 9. In FIG. 10, the frame region 20 of the first transparent liquid crystal display device 1000 overlaps with the display region 10 of the second transparent liquid crystal display device 2000, and the frame region 20 of the second transparent liquid crystal display device 2000 overlaps with the display region 10 of the first transparent liquid crystal display device 1000. In FIG. 10, the display regions 10 of the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 are hatched, but the directions of the hatching are different. As shown in FIG. 10, the display regions 10 of the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 are seamlessly connected.

[0035] Here, regarding seamless connection, the problem is how accurately the two display regions 10 can be joined together, and the joining accuracy can be achieved at about 10 μm. On the other hand, visually, if the sides of the display region 10 of the first transparent liquid crystal display device 1000 and the sides of the display region 10 of the second transparent liquid crystal display device 2000 coincide within 50 μm or less, it will look seamless.

[0036] FIG. 11 is a cross-sectional view taken along line A-A of FIG. 10. FIG. 11 has the same configuration as FIG. 8, except that the cross-sections of the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 are described in detail for each substrate. In FIG. 11, the display region AA1 of the first transparent liquid crystal display device 1000 and the display region AA2 of the second transparent liquid crystal display device 2000 are seamlessly connected.

[0037] FIG. 12 is a cross-sectional view taken along line B-B of FIG. 10. FIG. 12 shows the overlapping part of the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000. In FIG. 12, the upper first transparent liquid crystal display device 1000 is the display region, and the lower second transparent liquid crystal display device 2000 is the frame region. The lower transparent liquid crystal display device is shaded to indicate that it is the frame region, but this part is also transparent.

[0038] The portion shown in Fig. 12 also has an image formed by the first transparent liquid crystal display device 1000. In the second transparent liquid crystal display device 2000, although no image is formed in this portion, since the light from the light source enters from the side surfaces of the counter substrate 200 and the cover glass 400, the brightness of this portion does not decrease.

[0039] Fig. 13 is a cross-sectional view taken along the line C-C of Fig. 10. Fig. 13 shows the portion where the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 overlap. In Fig. 13, the upper first transparent liquid crystal display device 1000 is a frame region, and the lower second transparent liquid crystal display device 2000 is a display region. The upper transparent liquid crystal display device 1000 is shaded to indicate that it is a frame region, but this portion is also transparent.

[0040] The portion shown in Fig. 13 also has an image formed by the second transparent liquid crystal display device 2000. In the first transparent liquid crystal display device 1000, although no image is formed in this portion, since the light from the light source enters from the side surfaces of the counter substrate and the cover glass, the brightness of this portion does not decrease.

[0041] As shown in Figs. 12 and 13, even in the frame region of either transparent liquid crystal display device, an image is formed by the display region of the other transparent liquid crystal display device, so the image is not interrupted. Although it is necessary to accurately align the ends of the display region 10 of the first transparent liquid crystal display device 1000 and the display region 10 of the second transparent liquid crystal display device 2000, since this combination can be performed with an accuracy of about 10 μm, there is no problem in practical use.

[0042] Fig. 14 is a cross-sectional view taken along the line D-D of Fig. 10. Fig. 14 is a cross-sectional view of the display region 10 of the first transparent liquid crystal display device 1000. Fig. 14 has the same configuration in principle as the transparent liquid crystal display device shown in Fig. 3. In Fig. 14, the frame region 20 is shown shaded, but this portion is also surely transparent.

[0043] FIG. 15 is a cross-sectional view taken along the line E-E of FIG. 10. FIG. 14 is a cross-sectional view of the display area 10 of the second transparent liquid crystal display device 2000. FIG. 15 shows the state where FIG. 14 is turned over, and it has the same configuration as the transparent liquid crystal display device shown in FIG. 3 in principle. In FIG. 15, the frame area 20 is shown by shading, but this part is also surely transparent. Since the transparent liquid crystal display device can display the same image when viewed from the front surface or the back surface, the image formed in FIG. 14 and the image formed in FIG. 15 are recognized as the same image.

[0044] FIG. 16 is a plan view showing the configuration of the TFT substrate 100. The TFT substrate 100 is divided into a display area 10, a frame area 20, and a terminal area 30. In the display area 10, scanning lines 101 extend in the horizontal direction (x direction) and are arranged in the vertical direction (y direction). Also, video signal lines 103 extend in the vertical direction and are arranged in the horizontal direction. In the area surrounded by the scanning lines 101 and the video signal lines 103, pixels 105 including pixel electrodes and TFTs are formed.

[0045] The video signal lines 103 extend to the terminal area 30, and in the terminal area 30, they become video signal line leads 104 and are connected to the driver IC 51. The scanning lines 101 extend in the horizontal direction, and in the frame area 20, they become scanning line leads 102 and extend in the direction of the terminal area 30.

[0046] In the frame area 20 of FIG. 16, the scanning line leads 102 are diagonal wirings and extend toward the terminal area 30 side. In the frame area 20, there are parts where the scanning line leads 102 do not exist. In this part, an outer peripheral wiring 120 having a mesh shape (lattice shape) with a plurality of openings formed of metal is formed, and a common potential is applied to this outer peripheral wiring 120. The light transmittance of the frame area 20 is set to be approximately the same as that of the display area 10 by the scanning line leads 102 and the outer peripheral wiring 120.

[0047] In FIG. 16, a driver IC 51 that drives the video signal line 103 is disposed at the horizontal (x-direction) center of the terminal region 30. Also, driver ICs 52 that drive the scanning lines 101 are disposed on both sides of the driver IC 51. By dividing the driver IC in this way, the length of the routing of the lead wires can be suppressed.

[0048] FIG. 17 is a plan view of the counter substrate 200 corresponding to FIG. 16. The counter substrate 200 is divided into a display region 10 and a frame region 20. In the display region 10 of FIG. 17, a black matrix 201 is formed corresponding to the video signal line 103 and the scanning line 101 of FIG. 16. The role of the black matrix 201 is to improve the contrast of the image and to prevent the generation of photocurrent in the TFT formed on the TFT substrate 100. Since the width of the black matrix 201 is larger than the widths of the video signal line 103 and the scanning line 101, the transmittance of the display region 10 is substantially determined by the transmittance of the black matrix 201.

[0049] The black matrix 201 is not formed in the frame region 20. Therefore, the transmittance of the frame region 20 is determined by the scanning line lead wire 102 and the outer peripheral wiring 120 formed on the TFT substrate 100. A common electrode 202 is formed on the entire surface of the surface of the counter substrate 200 facing the TFT substrate 100 by a transparent electrode such as ITO (Indium Tin Oxide). The liquid crystal molecules 301 are driven by the electric field between the common electrode 202 formed on the counter substrate 200 and the pixel electrode 115 formed on the TFT substrate 100.

[0050] However, as long as the transmittance of the frame area 20 is not significantly different from that of the display area 10, a structure in which the black matrix 201 is provided in the frame area 20 may be adopted. As an example, the black matrix may be formed of a metal material, and a part of the black matrix 201 may be used as a potential supply line extending from the frame area 20 toward the display area 10 to supply a common potential to the common electrode 202. In another example, for the purpose of uniform appearance when viewed from the counter substrate 200 side, a black matrix having the same aperture ratio as the black matrix 201 in the display area 10 may be provided in the frame area 20 in a lattice pattern. Even in this case, since the black matrix 201 in the frame area 20 has a plurality of openings, the transparency of the frame area 20 is sufficiently ensured.

[0051] FIG. 18 is a plan view of a pixel. In FIG. 18, scanning lines 101 extend in the horizontal direction (x direction) and are arranged in the vertical direction (y direction), and video signal lines 103 extend in the vertical direction and are arranged in the horizontal direction. A pixel electrode 115 is formed in a region surrounded by the scanning lines 101 and the video signal lines 103. A TFT is formed as a switching element at the lower left of the pixel. In FIG. 18, a part of the scanning line 101 branches to form a gate electrode 110, and a semiconductor layer 111 is formed to cover this. In FIG. 18, the video signal line 103 branches to form a drain electrode 112. The source electrode 113 is connected to the pixel electrode 115 via a through hole 114.

[0052] FIG. 19 is a plan view of the counter substrate 200 and corresponds to the pixel on the TFT substrate 100 side in FIG. 18. In FIG. 19, a black matrix 201 is formed in a lattice pattern. The black matrix 201 is formed corresponding to the scanning lines 101 and the video signal lines 103 on the TFT substrate 100. Further, it is formed so as to cover the TFT in FIG. 18.

[0053] FIG. 20 is a plan view showing the shape of the outer peripheral wiring 120 formed in the frame region 20 of the TFT substrate 100. The outer peripheral wiring 120 is formed in a lattice shape and has a plurality of openings inside. The light transmittance is determined by the width wm and pitch pm of the wiring portions constituting the mesh shape (lattice) of the outer peripheral wiring. This transmittance is, for example, 84%. FIG. 21 is a plan view showing the shape of the scanning line extraction line 102 in the frame region 20 of the TFT substrate 100. The scanning line extraction line 102 is an oblique wiring. The light transmittance of the region where the scanning line extraction line 102 is formed is determined by the pitch ps of the scanning line extraction line 102 and the width ws of the scanning line extraction line 102. This transmittance is, for example, 84%.

[0054] Thus, the transmittance in the frame region 20 can be easily set. In the present invention, the light transmittance of the display region 10 and the light transmittance of the frame region 20 are made to match as much as possible. In the display region 10, the transmittance is determined by the black matrix 201 formed on the counter substrate 200. On the other hand, in the frame region 20, it is determined by the wiring width and wiring pitch of the scanning line extraction line 102 and the outer peripheral wiring 120 formed on the TFT substrate 100. Therefore, it is possible to easily set the light transmittance in both the display region 10 and the frame region 20. It is desirable that the transmittance of the display region 10 and the frame region 20 be 5% or less.

[0055] Realistically, the light transmittance of the frame region 20 is often matched to the light transmittance of the display region 10. The width of the frame region 20 will be determined in relation to the set light transmittance. Also, in order to make the influence of the transmittance variation as inconspicuous as possible, it is desirable that the light transmittance of the display region 10 and the frame region 20 be as high as possible. In this embodiment, the transmittances of the display region 10 and the frame region 20 are each 80% or more.

[0056] If a metal material with low electrical resistance is used for the scanning line 101, video signal line 103, scanning line lead-out line 102, etc. formed on the TFT substrate 100, the width of the wiring can be reduced, which is advantageous for improving the light transmittance of the transparent display device. In this embodiment, as these wirings, wirings having a structure in which Al is laminated on Mo are used. In particular, since Al can reduce the wiring resistance, the wiring can be made thinner. The same applies to the outer peripheral wiring 120 formed in the frame region 20.

Example

[0057] In Example 1, two transparent liquid crystal display devices are arranged in parallel to realize a large-screen transparent liquid crystal display device. The configuration described in Example 1 can also be applied when three or more transparent liquid crystal display devices are arranged in parallel to form an even larger screen. FIG. 22 is a schematic cross-sectional view when three transparent liquid crystal display devices are arranged in parallel to use a large-screen transparent display device.

[0058] In FIG. 22, the combination of the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 is the same as the configuration described in Example 1. In FIG. 22, the combination of the second transparent display device 2000 and the third transparent display device 3000 can also be combined according to the same principle as in Example 1.

[0059] That is, a large-screen transparent display device in which the display regions 10 having the width AA1, the display regions 10 having the width AA2, and the display regions 10 having the width AA3 are seamlessly connected can be formed. The same applies when forming a large-screen transparent liquid crystal display device using four or more transparent liquid crystal display devices.

Example

[0060] In Example 1, since two transparent liquid crystal display devices are used in an overlapping manner near the frame region 20, a step is generated. This step may affect visibility. FIG. 23 is a cross-sectional view showing this problem. Since FIG. 23 is the same as FIG. 8 of Example 1, the description of the structure will be omitted. In FIG. 23, depending on the use of the display device, the edges of the transparent liquid crystal display devices 1000 and 2000 indicated by arrow E may affect visibility.

[0061] FIG. 24 is a cross-sectional view of a transparent display device for countermeasures. In FIG. 24, a glass plate 500 is attached to the back surface of the TFT substrate 100 of the first transparent liquid crystal display device 1000 via an OCA 70. The thickness of the glass plate 500 is the sum of the thicknesses of three glass substrates and the thickness of the OCA of 0.1 mm. For example, when the thicknesses of the TFT substrate 100, the counter substrate 200, and the cover glass 400 are each 0.7 mm and the thickness of the OCA 70 is 0.1 mm, if the thickness of the glass plate 500 is set to 2.2 mm, the surface of the glass plate 500 and the surface of the second transparent liquid crystal display device 200 will be flush. Similarly, by attaching a glass plate 500 of the same thickness to the back side (upper side) of the TFT substrate 100 of the second transparent liquid crystal display device 2000, the surface of the first transparent liquid crystal display device 1000 and the surface of the glass plate 500 can be made flush.

[0062] By adopting the configuration as shown in FIG. 24, the surface of the transparent display device using a plurality of transparent liquid crystal display devices can be flattened, and the decrease in visibility due to the presence of steps can be countered. Also, in the configuration of FIG. 24, since it can be made the same as a single smooth plate, the handling of the transparent liquid crystal display device also becomes easy.

Example

[0063] In each of the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 in Example 1, the display region 10 is a superposition of three glass substrates, while the terminal region 30 is a single TFT substrate. Depending on the use of the transparent liquid crystal display device, the mechanical strength of the terminal region 30 may become a problem.

[0064] FIG. 25 is a perspective view of a transparent liquid crystal display device that addresses this issue. The difference between FIG. 25 and FIG. 9 of Example 1 is that the cover glass 410 is attached to the back side of the TFT substrate 100. This can reinforce the strength of the TFT substrate 100. The thickness of the cover glass 410 can be, for example, about 0.7 mm or 0.5 mm, the same as that of the TFT substrate. Since the other configurations of FIG. 25 are the same as those of FIG. 9 of Example 1, the description will be omitted.

Example

[0065] In Examples 1 to 4, the case where the transparent liquid crystal display device is flat was described. On the other hand, there is also a demand to use a curved transparent liquid crystal display device. Even in a transparent liquid crystal display device using a glass substrate, if the glass substrate is made thinner, it can be easily curved. The present invention can also be applied to such a curved display device.

[0066] When the display device is curved, various curvatures are possible. As representative examples, FIGS. 26 and 27 show the case of curving along the x-axis (horizontal axis) with a radius R, and FIGS. 28 to 30 show the case of curving along the y-axis (vertical axis) with a radius R. In the transparent display devices 1000 and 2000 shown in FIGS. 26 to 30, the terminal regions are omitted, and only the display region 10 and the frame region 20 are described.

[0067] FIG. 26 is an example in which an assembly of a first transparent liquid crystal display device 1000 and a second transparent liquid crystal display device 2000 is curved along the x-axis like a double-headed arrow. The first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 overlap near the frame region 20. FIG. 27 is a cross-sectional view taken along line F-F of FIG. 26. The configuration of FIG. 26 is the same as that described in FIG. 8 of Example 1 except that the first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 are curved.

[0068] FIG. 28 shows an example in which an assembly of a first transparent liquid crystal display device 1000 and a second transparent liquid crystal display device 2000 is curved along the y-axis like a double-headed arrow. The first transparent liquid crystal display device 1000 and the second transparent liquid crystal display device 2000 overlap in the vicinity of the frame region 20. Since the configuration of FIG. 28 is not curved in the x-axis direction, the cross-section I-I of FIG. 28 is the same as FIG. 8.

[0069] FIG. 29 is a cross-sectional view taken along line G-G of FIG. 28. In FIG. 29, the display region 10 of the first transparent liquid crystal display device 1000 and the frame region 20 of the second transparent liquid crystal display device 2000 overlap. FIG. 30 is a cross-sectional view taken along line H-H of FIG. 28. In FIGS. 29 and 30, the OCA is not shown. In FIG. 30, the frame region 20 of the first transparent liquid crystal display device 1000 and the display region 10 of the second transparent liquid crystal display device 2000 overlap. The configurations of FIGS. 29 and 30 are the same as those described in FIGS. 12 and 13 in the first embodiment, except that the transparent liquid crystal display devices 1000 and 2000 are curved. Thus, the present invention can also be applied to a curved transparent display device.

[0070] In the above description, the outer shape or the display region of the transparent display device is rectangular. However, the present invention can also be used for a transparent display device having an outer shape or a display region other than rectangular. That is, even for such a deformed transparent display device, by arranging the display region of the first transparent display device and the frame region of the second transparent display device to overlap, it is possible to arrange a plurality of display regions seamlessly. Thereby, even for a deformed transparent display device, a large-screen transparent display device can be realized using a plurality of transparent display devices.

[0071] Furthermore, in the description of this embodiment, the overlapping in the left and right frame regions and the display region has been described. However, in the upper frame region on the opposite side of the light source side, the display regions and the upper frames of a plurality of transparent display devices may be overlapped so that the display regions can be seamlessly connected.

Description of Reference Numerals

[0072] 10…Indicating area, 20…Frame area, 30…Terminal area, 40…Light source, 41…LED, 42…Lens, 50…Driver IC, 51…Video signal line driver IC, 52…Scanning line driver IC, 60…Transparent sealing material, 70…OCA, 100…TFT substrate, 101…Scanning line, 102…Scanning line lead-out wire, 103…Video signal line, 104…Video signal line lead-out wire, 105…Pixel, 110…Gate electrode, 111…Semiconductor layer, 112…Drain electrode, 113…Source electrode, 114…Through hole, 115…Pixel electrode, 120…Peripheral wiring, 200…Counter substrate, 201…Black matrix, 202…Common electrode, 300…Liquid crystal layer, 301…Liquid crystal molecules, 400…Cover glass, 410…Cover glass, 500…Glass plate, 1000…First transparent liquid crystal display device, 2000…Second transparent liquid crystal display device, 3000…Third transparent liquid crystal display device, 5000…Pedestal

Claims

1. The first display device has a first display area and a first frame area disposed outside the first display area. The second display device has a second display area and a second frame area disposed outside the second display area. The first display device and the second display device are arranged in parallel with a part of them overlapping each other. The first frame area of the first display device overlaps with the second display area of the second display device, and the second frame area of the second display device overlaps with the first display area of the first display device. Viewed in a plane, the first display area and the second display area are continuous. The light transmittance of the first display area is 80% or more, and the light transmittance of the second display area is 80% or more. The light transmittance of the first frame area is 80% or more, and the light transmittance of the second frame area is 80% or more. A display device, wherein the difference between the light transmittance of the first display area and the light transmittance of the first frame area is 5% or less, and the difference between the light transmittance of the second display area and the light transmittance of the second frame area is 5% or less.

2. The display device according to claim 1, wherein the shapes of the first display area and the second display area are rectangular.

3. A first transparent substrate is attached to the first display device, and a second transparent substrate is attached to the second display device. The state of the first display device and the second display device is plate-shaped as a whole. The display device according to claim 1 is characterized in that.

4. A first liquid crystal display device in which a first TFT substrate and a first counter substrate are adhered by a first sealing material in the first frame area, a first liquid crystal is sandwiched inside, and a first display area is formed in the area where the first liquid crystal is sandwiched, and A second liquid crystal display device in which a second TFT substrate and a second counter substrate are adhered by a second sealing material in the second frame area, a second liquid crystal is sandwiched inside, and a second display area is formed in the area where the second liquid crystal is sandwiched, are arranged in parallel with a part of them overlapping each other. The first frame area of the first liquid crystal display device overlaps with the second display area of the second liquid crystal display device, and the second frame area of the second liquid crystal display device overlaps with the first display area of the first liquid crystal display device. Viewed in a plane, the first display area and the second display area are continuous. The light transmittance of the first display area is 80% or more, and the light transmittance of the second display area is 80% or more. The light transmittance of the first frame area is 80% or more, and the light transmittance of the second frame area is 80% or more. A liquid crystal display device, wherein a difference between the light transmittance of the first display area and the light transmittance of the first frame area is 5% or less, and a difference between the light transmittance of the second display area and the light transmittance of the second frame area is 5% or less.

5. In the first TFT substrate, a first terminal area is formed in a portion where the first counter substrate does not overlap. In the first terminal area, a first light source including a first LED is arranged to face a first side surface of the first counter substrate. In the second TFT substrate, a second terminal area is formed in a portion where the second counter substrate does not overlap. The liquid crystal display device according to claim 4, wherein a second light source including a second LED is arranged in the second terminal area to face a second side surface of the second counter substrate.

6. In the first display area, first scanning lines extend in a first direction and are arranged in a second direction, and first video signal lines extend in the second direction and are arranged in the first direction. In the first frame area, a first scanning line lead-out line connected to the first scanning line is formed, and a lattice-shaped first common electrode is formed in an area where the first scanning line lead-out line is not formed. In the second display area, second scanning lines extend in a first direction and are arranged in a second direction, and second video signal lines extend in the second direction and are arranged in the first direction. The liquid crystal display device according to claim 4, wherein in the second frame area, a second scanning line lead-out line connected to the second scanning line is formed, and a lattice-shaped second common electrode is formed in an area where the second scanning line lead-out line is not formed.

7. The liquid crystal display device according to claim 4, wherein the first liquid crystal and the second liquid crystal are polymer dispersed liquid crystals.

8. A surface of the first TFT substrate on a side opposite to the first counter substrate The liquid crystal display device according to claim 4, wherein a surface of the second TFT substrate on a side opposite to the second counter substrate is adhered by a transparent adhesive sheet.

9. A first cover glass is attached to the first counter substrate, and the first light source also faces the side surface of the first cover glass. The liquid crystal display device according to claim 5, wherein a second cover glass is attached to the second counter substrate, and the second light source also faces the side surface of the second cover glass.

10. A first transparent substrate is attached to the first liquid crystal display device, a second transparent substrate is attached to the second liquid crystal display device, and the state of the first liquid crystal display device and the second liquid crystal display device is plate-shaped as a whole. The liquid crystal display device according to claim 4, characterized in that.

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