JP2001352068A - Substrate, display element, and display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost and a robust portable terminal display element and a display unit, and also to provide a display which allows one to casually watch TV, wherever one may be. SOLUTION: This display uses a transparent or a colored high molecular substrate, at least a part of the surface of which is covered by a conductive material, and a substrate which is the same one as this but is provided on the surface with a plurality of thin-film transistors, each of which consists of three terminals, that is, gate electrode, source electrode, and drain electrode, and an active semiconductor layer constituted of an organic thin film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate and a liquid crystal display device or a light emitting display device, and a portable terminal display device and a video display device using the same.

[0002]

2. Description of the Related Art There is an increasing demand for a small and lightweight portable terminal display device, and the development of a light and strong substrate for a display device is remarkable. In particular, there is an urgent need to use plastic materials as substrate materials for liquid crystal display elements. On the other hand, display quality needs to be improved, and improvement in image quality by TFT driving has been studied. On the other hand, efforts to reduce the price of large flat panel displays are highly expected. As large-sized display devices, there are a liquid crystal display device and a PDP plasma display panel, but both tend to significantly increase the manufacturing cost as the size increases. Therefore, innovation of the manufacturing method is required as the size increases. In recent years, organic light-emitting elements, which are self-luminous display elements, have attracted attention in addition to liquid crystal display apparatuses, and have begun to show potential as small portable terminal display apparatuses. Further development is underway to improve image quality in combination with an a-Si transistor. Organic light emitting devices have the potential to be formed at low cost by low temperature processes and low molecular light emitting devices by vapor deposition and polymer light emitting devices by coating.

[0003]

SUMMARY OF THE INVENTION An inexpensive and robust portable terminal display device and display device are provided. Furthermore, a display device that allows the user to easily watch television anywhere is also provided.

[0004]

In order to provide an inexpensive and durable liquid crystal display device or organic light-emitting device, a transparent or colored polymer substrate having at least a part of the surface covered with a conductive material and a transparent or colored polymer substrate are provided. Gate electrode, source electrode,
A substrate on which a plurality of thin film transistors each including three terminals of a drain electrode and an active semiconductor layer of an organic thin film are arranged is used.

Further, in order to form an organic transistor on a polymer substrate at a low temperature and maintain its characteristics stably, in order to block moisture that enters from outside, which is a major obstacle, at least a part of the surface is made of a conductive material. A covered transparent or colored polymer material, a substrate having the surface of the polymer material covered with a gas barrier film, and three terminals of a gate electrode, a source electrode, a drain electrode and an active semiconductor layer of an organic thin film on the substrate. A substrate on which a plurality of thin film transistors made of are arranged is used.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 is composed of a liquid crystal element substrate, a liquid crystal layer, and a counter substrate, each having an inverted staggered organic transistor and a storage capacitor formed for each pixel on a plastic substrate covered with a barrier layer. 1 shows a cross-sectional configuration example of a liquid crystal display element to be used. In FIG. 1, it is a polymer substrate material 1,
Typically, polycarbonate, polyether sulfone,
Examples include polyacrylate and polyimide. 0.4m thick
A sheet shape of about m is a typical example, but may be a thick plate of about 1 mm to about 10 mm, or may be 0.5 mm to several mm. The gas barrier layer 2 is typically formed of a SiO2 film. As another example, a material having gas barrier properties such as Ta2O5 and Al2O3 may be used. The film thickness is about 1
Angstroms to thousands angstroms are optimal. Note that the gas barrier layer may be provided outside the polymer substrate. Further, a protective layer for preventing flaws may be provided on the outermost side. The gate electrode 3 typically uses gold, palladium, chromium, or the like. Typically, aluminum or chromium is used for the drain electrode 4 and the source electrode 5. Each electrode material was formed at a substrate temperature setting of room temperature to 100 ° C. The film thickness ranges from hundreds to thousands of angstroms. Polyorganosiloxane that can be applied and formed is used for the gate insulating layer 6 and the interlayer insulating layer 7. The thickness depends on the size of the auxiliary capacitor, but is in the range of hundreds to thousands of angstroms. As the organic thin film as the active semiconductor layer 8, a thiophene oligomer or pentacene, which can form a film having large fine crystal grains and good orientation by an evaporation method, was used. The size of the fine particles is from several microns to several tens of microns, and the mobility thereof can be as large as 1.0 or more than the mobility of a-Si. Although this mobility depends on the substrate temperature and the deposition rate during film formation, the substrate temperature can be set from room temperature to 100 ° C. The film thickness is in the range of tens to thousands of angstroms, and is typically formed at 500 angstroms. In particular, the crystallinity of the organic vapor-deposited layer is important for transistor performance, but the interface between the gate oxide film 6 and the active layer 8 is also important. Therefore, in the film formation near the interface, it is necessary to sufficiently suppress the deposition rate. In order to form a liquid crystal display element, a polyimide alignment film 12 that can be formed at a low temperature was applied on an opposing substrate on which an organic transistor substrate, a color filter, and a transparent electrode 13 were formed. After performing a normal rubbing treatment, beads were dispersed and a cell was assembled.

(Embodiment 2) FIG. 2 shows an organic transistor having an inverted staggered structure formed for each pixel on a plastic substrate 1 covered with a barrier layer 2, a hole transport layer 14, and electroluminescent layers 16 and 17. 1 shows a cross-sectional configuration example of a light-emitting display element including an organic light-emitting layer including an electron transport layer 19 and an electron transport layer 19. The structure of the substrate is the same as that of FIG. 1, but an ITO film is formed as a transparent electrode 9 on the entire surface inside. The three films in charge of the light emitting function on the ITO are a hole transport layer 14 typified by triphenylamine which can be vacuum deposited at room temperature, an electron transport layer 19 typified by oxadiazole, and a green light emitting layer 16.
A luminous layer of aluminum quinoline, perylene of red emission 17 and tetraphenylbutadiene of blue emission 18 was formed. Each film thickness is several tens to several thousand angstroms. An organic transistor was further formed on the light emitting layer by an evaporation method. After forming the gate electrode 3, forming the gate insulating film 6, forming the active layer 8, forming the source electrode 4 and the drain electrode 5, the entire surface is covered with a passivation film to complete the device.

(Embodiment 3) FIG. 3 is a schematic diagram of a mobile phone 20 incorporating a liquid crystal display element 21 using an organic transistor and the plastic substrate of FIG. The number of pixels in the display portion is color QVGA. Since a TFT driven liquid crystal element having good image quality can perform the entire panel manufacturing process at 100 ° C. or less, it can be mass-produced at low cost. Conventional a-Si
In the case of a transistor, a CVD process was required to be 200 degrees or more, and a plastic substrate could not be used. Furthermore, it has excellent environmental resistance and can maintain stable display performance.

FIG. 4 is a schematic diagram of a mobile phone 20 incorporating the organic light emitting element 22 using the plastic substrate and the organic transistor of FIG. The number of pixels in the display portion is color QVGA. A TFT driven organic light emitting device having good image quality can be manufactured at low cost. Efficiency that cannot be achieved with the current passive drive is possible.

(Embodiment 4) FIG. 5 shows an embodiment in which the liquid crystal display element 21 of the plastic substrate shown in FIG. 1 is enlarged to form a liquid crystal TV 23 having a diagonal size of 20 inches. Extremely light, durable and easy to carry, unlike conventional glass substrates, it is a shock-resistant and safe display. FIG. 6 shows an organic light-emitting display element 22 of the plastic substrate shown in FIG.

[0012]

As described above, according to the present invention, a liquid crystal cover element and an organic light emitting element which are inexpensive and durable by using a polymer substrate on which an organic transistor is formed, and a portable terminal device and an image display using the same are provided. The device can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a liquid crystal display device using a polymer substrate according to a first embodiment of the present invention.

FIG. 2 shows an organic light emitting device using a polymer substrate according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of a mobile phone incorporating a liquid crystal display element using a plastic substrate and an organic transistor according to a third embodiment of the present invention.

FIG. 4 is a schematic diagram of a mobile phone incorporating an organic light-emitting element using a plastic substrate and an organic transistor according to a third embodiment of the present invention.

FIG. 5 is a schematic diagram of a liquid crystal TV incorporating a liquid crystal display device using a plastic substrate and an organic transistor according to a fourth embodiment of the present invention.

FIG. 6 is a schematic diagram of an organic light emitting thin TV incorporating an organic light emitting device using a plastic substrate and an organic transistor according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polymer substrate 2 Gas barrier layer 3 Gate electrode 4 Drain electrode 5 Source electrode 6 Gate insulating layer 7 Interlayer insulating layer 8 Active semiconductor layer 9 Transparent electrode 10 Common electrode 11 Auxiliary capacitance layer 12 Alignment film 13 Liquid crystal layer 14 Hole transport layer 15 Electrode 16 Green light emitting layer 17 Red light emitting layer 18 Blue light emitting layer 19 Electron transport layer 20 Mobile phone 21 Liquid crystal element on plastic substrate 22 Organic light emitting element on plastic substrate 23 Liquid crystal TV 24 Thin TV

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G09F 9/30 338 H01L 29/78 618B 5F110 H04N 5/66 102 G02F 1/1335 530 5G435 // G09F 9 / 00 302 1/136 500 F term (for reference) 2H090 JA07 JB03 JC07 JD11 LA01 LA04 LA17 2H091 FA44Z FB02 GA01 GA13 GA16 LA12 2H092 JA26 KA09 KA13 KA18 KB25 MA04 NA27 PA01 PA08 5C058 AA06 AB06 BA35 5C094 AA18BA03A29A EA07 EB01 FB01 FB14 HA08 HA10 5F110 AA30 BB01 CC07 DD01 DD19 EE02 EE04 FF01 FF21 GG05 GG41 GG42 HK03 HK04 NN02 NN22 NN32 NN72 NN73 5G435 AA06 BB05 EE37 GG31 LL07

Claims (8)

[Claims] 1. A transparent or colored polymer substrate whose surface is at least partially covered with a conductive material, and three terminals of a gate electrode, a source electrode and a drain electrode and an active semiconductor layer of an organic thin film on the substrate. A substrate on which a plurality of thin film transistors are arranged. 2. A transparent or colored polymer material at least partially covered with a conductive material, a substrate having a surface covered with a gas barrier film, a gate electrode on the substrate, A substrate on which a plurality of thin film transistors including three terminals of a source electrode and a drain electrode and an active semiconductor layer of an organic thin film are arranged. 3. A liquid crystal display device comprising at least the substrate according to claim 1 or 2, a liquid crystal layer, and a counter substrate covered with a transparent conductive material. 4. An organic light emitting display device comprising at least the substrate according to claim 1 or 2 and an organic electroluminescent layer. 5. A mobile terminal display device using a liquid crystal display element comprising the substrate according to claim 1 or 2, a liquid crystal layer, and a counter substrate covered with a transparent conductive material. 6. A portable terminal display device using an organic light emitting display element comprising at least the substrate according to claim 1 or 2 and an organic electroluminescent layer. 7. A video display device comprising a television tuner and a liquid crystal display element comprising at least the substrate according to claim 1 or 2, a liquid crystal layer, and a counter substrate covered with a transparent conductive material. 8. An image display device comprising a television tuner and an organic light emitting display element comprising at least the substrate according to claim 1 or 2 and an organic electroluminescent layer.