JPH05289619A - Flat panel type image display device - Google Patents

Abstract

PURPOSE:To enable a large-amount display in the display use state and obtain compactness in the nonuse state by composing display areas of plural display units, and folding those display units together compactly. CONSTITUTION:The display areas 1 consists of the two liquid crystal display units with a 10 inch diagonal and each of the liquid crystal display devices employ the active matrix driving of thin film transistors. Then, they are folded together with their display surfaces in. One document of size A4 can be displayed on one display part 1, so information equivalent to size A3 can be displayed at a time by the whole image display device. Those liquid crystal display devices are electrically connected by using, for example, a flexible print wiring. Namely, the two display parts 1 are correlated to each other and complicated processing is carried out through a display of a large amount of data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image information display device, and more particularly to a computer, a word processor or a T.
The present invention relates to a flat panel image display device for graphics such as V, characters, and images.

[0002]

2. Description of the Related Art In recent years, downsizing of information devices such as computers has been further advanced. That is, there is a remarkable momentum in progress in thinning and weight reduction, as represented by notebook computers and word processors. In particular, the flat panel display has been greatly advanced, and power saving has been realized. In the process, development of a liquid crystal display (LCD) capable of displaying a large capacity has accelerated downsizing.

An example of such a thin and lightweight device is shown in FIG. This is an example of a laptop computer, where the keyboard and display part form the main part. These are 3-5 cm thick when folded as shown in Fig. 7 (b).
And, it is much more compact than the display using the CRT until then.

More recently, a flat panel type display having a diagonal of 10 "to 14" has been developed, and the display capacity has been further increased.

[0005]

However, according to the conventional flat panel type image display device, the limit is one ISO standard A4 size, and it is the current situation that further increase in capacity is desired. At that time, for example, if a word processor is taken into consideration, at least one spread sheet of A3 size, that is, two sheets of A4 size are required from the viewpoint of ease of document creation and editing. Although a display (diagonal about 21 ″) capable of displaying this capacity has already been realized in a CRT, the shape and weight of the device have to be extremely large.

On the other hand, it is not easy or practical to realize such a large-capacity display by using a flat panel type image display device having a conventional structure. The reason is as follows.

In the flat panel type image display device having the conventional configuration, as the screen size increases,
Manufacturing with high yield becomes difficult, and the price of the image display device itself becomes very expensive.

Even if they can be easily manufactured, the A3 size flat panel image display device is not very portable and is not easy to use.

As described above, when a display is used for document editing and display, a large-capacity display corresponding to at least an A3 size document or image is possible, and when not in use, the image display is compact and easy to carry. A device was needed.

[0010]

[Means for Solving the Problems] Such a large capacity display,
In addition, in order to realize a compact display, in the present invention, a display area is configured by a plurality of flat panel type display devices, and a mechanism is provided for folding these flat panel type display devices into a compact size. It was Further, in order to cope with large-capacity display, each of the plurality of flat panel display devices has a diagonal size of 10 ″ or more, and each display device can display an A4 size document or image.

[0011]

In the flat panel image display device according to the present invention, the image display area is composed of a plurality of flat panel type display devices, and each display device is capable of displaying an A4 size document or an image, so that at least an A3 size image display device is provided. The corresponding large capacity can be displayed. Further, since it has a mechanism capable of folding these display devices, portability is also good.

[0012]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to FIG. FIG. 1A shows the configuration of a flat panel type image display device according to the present invention. The image display section is composed of two liquid crystal display devices each having a diagonal of 10 ".
As shown in (b), it is characterized by a structure in which each display surface is folded inward. One diagonal 1
Since the display unit of 0 ″ can display approximately one A4 size document, the entire image display device can simultaneously display information that is almost equivalent to A3 size. Further, it is compact in this way. The image display device can be formed in the following manner, since it has a folding mechanism, which is convenient from the viewpoint of portability.

First, a method of manufacturing each liquid crystal display device 1 will be described. All liquid crystal display devices are based on active matrix driving using thin film transistors. The pixel arrangement of the liquid crystal display device 1 is shown in FIG. Further, FIG. 3 is a main part of the sectional structure. In the liquid crystal display device, pixels having a thin film transistor (hereinafter TFT) 5 and a transparent pixel electrode 16 made of tin oxide (hereinafter ITO) are formed on the inner surface (liquid crystal side) of the lower transparent glass substrate 3.
Each pixel is arranged in an intersecting area between two adjacent vertical scanning signal lines 7 or gate signal lines and two adjacent horizontal scanning signal lines 6 or image signal lines.

The TFT 5 of each pixel is mainly composed of the gate electrode 8,
It is composed of gate insulating films 12 and 13, an i-type semiconductor layer 9, a pair of source electrode 11 and drain electrode 10.
The gate electrode is made of the same metal conductor as the vertical scanning signal line, and extends in a T shape from the vertical scanning signal line. As the metal conductor, one having a low resistance is selected in order to increase the transmission speed of the gate drive signal. For example, an Al film formed by sputtering is used.

The gate insulating film is formed on the gate electrode and the vertical scanning signal line. The gate insulating film has a two-layer structure in order to maintain good interlayer insulation. The first layer is A
The Al oxide film 12 formed by anodizing the 1 film and the second layer are silicon nitride films (SiN) 13 formed by the CVD (Chemical Vapor Deposition) method.

The i-type semiconductor layer 9 is used as a channel forming region of the TFT. In each TFT 5, the i-type semiconductor layer forms an island region. The i-type semiconductor layer is formed of an amorphous silicon film or a polycrystalline silicon film and has a thickness of 0.02.
It is formed with a film thickness of about 0.3 μm.

The drain electrode and the source electrode of the TFT are formed so as to be in contact with at least the i-type semiconductor layer and overlap each other, and are also separated from each other. Each of the source electrode and the drain electrode is configured so that the source and the drain are switched in operation when the bias polarity of the circuit changes. That is, the TFT is bidirectional. The drain electrode and the source electrode are the first conductive film 14, the second conductive film 15, and the second conductive film 15 from the lower layer side in contact with the i-type semiconductor layer.
The third conductive film 16 is sequentially stacked. The first conductive film, the second conductive film, and the third conductive film of the drain electrode are
It is formed in the same manufacturing process as each of the source electrodes.

The first conductive film 14 is C formed by sputtering.
An r film is used to form the film with a thickness of 0.04 to 0.1 μm. C
As the r film becomes thicker, stress stress increases, so
It is formed in a range not exceeding the film thickness of 0.2 μm. The Cr film has good contact with the i-type semiconductor layer,
It prevents Al of the conductive film from diffusing into the i-type semiconductor layer. The first conductive film is made of a refractory metal (Mo, T
i, Ta, W) or a silicide film which is a compound of these and Si.

The second conductive film 15 is formed by sputtering.
It is formed to a thickness of 0.3 to 0.4 μm by using a 1-layer film. Al film is C
The stress stress is smaller than that of the r film, the film can be formed to have a large film thickness, and the resistance values of the source electrode, the drain electrode, and the horizontal scanning signal line are reduced. The second conductive film may be formed of an Al film containing Si or Cu in addition to the Al film.

The third conductive film 16 is made of ITO formed by sputtering and has a film thickness of 0.1 to 0.2 μm. The third conductive film serves as a source electrode, a drain electrode, a horizontal scanning signal line, and a transparent pixel electrode. The source electrode is formed along the step shape of the i-type semiconductor layer and is connected to the transparent pixel electrode.

A protective film 1 is formed on the TFT and the transparent pixel electrode.
7 is provided. The protective film is formed mainly for protecting the TFT from moisture, and a film having high transparency and good moisture resistance is used. The protective film is formed of, for example, a SiO ₂ film or a SiN film formed by plasma CVD, and has a film thickness of about 0.6 to 0.8 μm.

The liquid crystal is a nematic liquid crystal 18, which is enclosed in a space formed between the lower transparent glass substrate 3 and the upper transparent glass substrate 4, and which has a lower alignment film 19 and an upper alignment film for setting the orientation of liquid crystal molecules. It is regulated in 20. The lower alignment film is formed on the protective film 17 on the lower transparent glass substrate side. On the inner surface of the upper transparent glass substrate, the IT of the color filter 21, the protective film 22, and the common transparent electrode 23 is formed.
O and an upper alignment film are sequentially stacked and provided.

In the color filter 21, a dyeing base material is formed on the surface of the upper glass substrate, and the dyeing base material other than the red filter forming region is removed by a photolithography technique. Thereafter, the dyeing base material is dyed with a red dye, A fixing process is performed to form a red color filter. Next, by performing the same process, a green filter and a blue filter are sequentially formed. In this way, each color of the color filter faces each pixel.

In the liquid crystal display device 1, the lower transparent glass substrate side and the upper transparent glass substrate side layers are formed separately, and then the upper and lower transparent lath substrates are superposed on each other and the nematic liquid crystal 18 is enclosed between them. Be assembled by

The respective pixels of the liquid crystal display section are arranged in a matrix as shown in FIG. The color filter is an RGB stripe pattern in the vertical direction, and is configured to enhance the visibility of the display when displaying characters.

An equivalent circuit diagram of this liquid crystal display section is shown in FIG. X1G, X2G, ... In FIG. 4 are image signal lines connected to pixels in which the green filters G are formed. X1
B, X2B, ... Are image signal lines connected to the pixels where the blue filter B is formed. X1R, X2R, ... Are image signal lines connected to the pixels in which the red filter R is formed. These image signal lines are selected by the horizontal scanning circuit. Y1 is a gate signal line for selecting the pixel column X1 shown in FIG. Similarly, each of Y2, Y3, ...
A gate signal line for selecting each of the pixel columns X2, X3, .... These gate signal lines are connected to the vertical scanning circuit.

The central portion of FIG. 3 shows a cross section of one pixel portion, while the left side shows a cross section of a portion on the left side edge of the upper and lower transparent glass substrates where the external lead-out wiring 24 exists. The right side shows a cross section of the right side edge of the upper and lower transparent glass substrates where external lead wires are not present. The sealing material 25 shown on each of the left side and the right side of FIG. 3 is configured to seal the nematic liquid crystal, and is formed along the entire periphery of the upper and lower transparent glass substrates excluding the liquid crystal enclosing port (not shown). ing. As the sealing material, for example, epoxy resin is used. The common transparent pixel electrode ITO on the upper transparent glass substrate side is connected to the external lead-out wiring formed on the lower transparent glass substrate side by the silver paste material 26 at at least one location. The external lead wiring is formed in the same manufacturing process as that of the gate electrode, the source electrode, and the drain electrode described above.

The respective layers of the alignment film, the transparent pixel electrode, the common transparent pixel electrode, the protective film and the insulating film are formed inside the sealing material. The polarizing plate 27 is formed outside each of the lower transparent glass substrate and the upper transparent glass substrate.

The horizontal wiring circuit of FIG.
A vertical scanning circuit is connected. A flat panel liquid crystal display device is formed by these circuits, the liquid crystal panel substrate, and the backlight 28. As the backlight, for example, a white fluorescent tube having a peak at GGB3 wavelength is used. The thickness of the flat panel is about 20 mm.

The liquid crystal display device thus manufactured is
A foldable image display device as shown in FIG. 1 is configured by using the individual pieces. The thickness of the device when folded is about 40
mm. The respective liquid crystal display devices are electrically connected. This connection may be made using a flexible printed wiring, for example. As described above, according to the present invention, since the two display units are correlated with each other, more complicated processing can be executed through displaying a large amount of data.

(Embodiment 2) In the second embodiment, an example in which a word processor is constructed using the flat panel type image display device according to the present invention will be shown. The structure is shown in FIG.

Two flat panel type image display units each having a diagonal of 10 "and an input device such as a keyboard and a mouse,
It is composed of a CPU that performs calculation and other arithmetic processing, and a storage device using a floppy disk. The CPU and the floppy disk may be incorporated in one of the liquid crystal display devices.

The word processor using the flat panel image display device according to the present invention can be provided with the following functions, for example.

A different page is displayed on these two flat panel image display sections, and a function is provided to enable editing on the respective display screens.

A function of displaying a document being edited on one screen and displaying the print layout on one screen.

With these functions, it is possible to realize a user-friendly operating environment which has never been available. As a result, it is possible to greatly improve the situation that "a corrected portion is not found until printing is performed on a paper surface" which is often seen in the past.

In the present embodiment, the two liquid crystal display portions are formed in a two-page spread form of the book, but as shown in FIG. 6, one liquid crystal display portion may be left stationary and the other liquid crystal display portion may be opened up.

Although the word processor has been described in the present embodiment, it is of course possible to use it as a display device of a personal computer. In that case, by providing a function of running different applications having data compatibility on each display screen, an extremely user-friendly operating environment can be realized.

(Embodiment 3) The third embodiment is an example in which the flat panel type image display device according to the present invention is used as a TV image display device. This configuration is shown in FIG. According to this, different programs can be displayed on the respective screens as shown in FIG. In other words, one display device
Screen support is possible. Alternatively, as shown in FIG. 8B, it becomes possible to support a landscape TV screen such as a high definition TV. Further, as shown in FIG. 9, by providing at least three bending points, it is possible to realize two screens and one
You can switch screen correspondence.

Although the configuration using the liquid crystal display device and the application example thereof have been described above for the flat panel type image display device of the present invention, the present invention is not limited to the above embodiments.

For example, the liquid crystal material of the liquid crystal display is not limited to nematic liquid crystal, but may be polymer dispersed liquid crystal or ferroelectric liquid crystal. The driving method of the liquid crystal display is not limited to the active matrix method, but may be the simple matrix method. Moreover, color display is not necessary for word processing applications. In that case,
It is possible to omit the manufacturing process of the color filter.

Besides, the flat panel type image display device of the present invention is not limited to the one using the liquid crystal display device. If the flat panel display device is capable of displaying documents or images of about A4 size, the effect of the present embodiment is impaired even if the display is a plasma display, an electroluminescent display, or an LED array or a cathode array. There is no such thing.

[0043]

According to the present invention, it is possible to provide an image display device capable of displaying a large capacity corresponding to at least A3 size without impairing portability. Moreover, the display surface can be protected during storage by the mechanism for bending the image display portion inward. Furthermore, since a plurality of image display units are provided, it is possible to avoid increasing the size of a single image display device.

[Brief description of drawings]

FIG. 1 is a perspective view showing a basic configuration of a flat panel type image display device of the present invention.

FIG. 2 is a layout diagram of pixels of a liquid crystal display device.

FIG. 3 is a sectional view of a main part of a liquid crystal display device.

FIG. 4 is an equivalent circuit diagram of a liquid crystal display device.

FIG. 5 is an explanatory diagram showing an application example of the flat panel image display device of the present invention.

FIG. 6 is a perspective view showing another usage of the flat panel image display device of the present invention.

FIG. 7 is a perspective view for explaining an application example of a conventional flat panel image display device.

FIG. 8: TV of flat panel type image display device of the present invention
FIG. 11 is a perspective view showing an application to an image display device.

FIG. 9 is a perspective view for explaining an application of the flat panel image display device of the present invention to another type of TV image display device.

[Explanation of symbols]

 1 ... Liquid crystal display part, 2 ... Folding direction.

Front Page Continuation (72) Inventor Toshihisa Tsukada 1-280 Higashi Koikekubo, Kokubunji City, Tokyo Inside Central Research Laboratory, Hitachi, Ltd.

Claims (9)

[Claims] 1. A flat panel type image display device comprising a plurality of image display portions. 2. The flat panel type image display device according to claim 1, wherein the plurality of image display portions have the same shape and are arranged in line symmetry with each other. 3. A flat panel type image display device according to claim 1, further comprising a mechanism for bending the plurality of image display portions so that their display surfaces are at least inside. 4. The flat panel image display device according to claim 3, wherein the bent portion is a line of symmetry of the line symmetrical arrangement. 5. The flat panel according to claim 1, 2, 3 or 4, wherein the plurality of image display portions are two image display portions, and the size of each image display portion is 10 inches or more diagonally. Type image display device. 6. The method according to claim 1, 2, 3, 4 or 5.
A flat panel type image display device in which the plurality of image display portions are liquid crystal display devices including a thin film transistor array formed on a glass substrate. 7. The word processor according to claim 1, 2, 3, 4, 5 or 6, wherein the flat panel image display device is used. 8. A computer using a flat panel image display device according to claim 1, 2, 3, 4, 5 or 6. 9. A TV image display device according to claim 1, 2, 3, 4, 5 or 6, wherein the flat panel image display device is used.