JPS60191288A - Color display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a first substrate provided with a thin film transistor (TPT) array having several electrodes serving as display element units, and a second substrate provided with a counter electrode. The present invention relates to a display device that displays images by electro-optical changes occurring between these substrates, and particularly relates to a color display device that displays colors by providing a color filter.

Conventionally, this type of device uses materials such as liquid crystal, EC (electrochromy), and EL (electroluminescence) as electro-optic modulation controls, and uses a thin film structure to fabricate a semiconductor array for small movement on a substrate. A structure is used in which a first substrate is provided with an electrode, a second substrate is provided with a counter electrode, and a layer of an electro-optic modulation material is sandwiched between these substrates.

Hereinafter, as a representative example, a liquid crystal display device having a thin film semiconductor structure will be described with reference to the drawings.

FIGS. 1(a) and 1(b) show examples of substrates having thin film semiconductors, and FIG. 2 shows an example in which this is configured as a liquid crystal display device. That is, FIG. 1(a) shows thin film transistors for actual use (T
FT: Th1n Film Transiator). TPT includes dart electrodes 1 r 1' provided on the dart lines 1a and 1a' (made of a transparent or metal thin film conductive group) formed on the substrate S.
Thin film semiconductors 2, 2/, 2'', 2/ formed on the above f-)'l electrodes with an insulating film I interposed therebetween.
//, a source line (made of a conductive film) 3゜3' provided in contact with the end of the semiconductor device, and a drain electrode 4゜4', 4", 4"1 provided at the other end of the semiconductor (composed of has been done.

The drain electrodes 4.4', 4'', and 4'' constitute electrodes serving as units of display elements. FIG. 1(b) is a plan view viewed from the direction of arrow B in FIG. 1, and shows a part of the matrix drive circuit.

In addition, FIG. 2 shows that the substrate shown in FIG. 1 and the counter electrode substrate are 4
Figure 1 (b) shows a liquid crystal display device constructed by
) is an enlarged sectional view taken along line AA'.

In FIG. 2, 7 and S are substrates such as glass, 4" and 4"' are the aforementioned drain electrodes (in return, 8 is a counter electrode).

For 4, 4'''1...8, etc., a transparent conductive film such as engineering n206, 5n02, etc. or a metal thin film such as Au, AI, Pd, etc. is used depending on the case.1'', 1''' and 2' + 2 ″
' are a dirt electrode and a source line, respectively, and AI,
Metals such as Au, Ag, Pt, Pd, and Cu are used.

5.5' specifically shows an example in which the insulating film is formed only on the dirt line such as 1ay1 a/, and 9 is the insulating film provided as necessary. 21/, ell/ is C.
d8. A semiconductor such as CdSe, Te, amorphous silicon, etc., 10 is a spacer, and 11 is a liquid crystal layer. In addition, in display devices, various liquid crystal molecule orientation states are available depending on whether a display mode such as excited scattering mode (DSM) or twisted nematic (TN) is used, or whether the device is a transmission type or a reflection type. Optical detection means such as a polarizing plate, a λ/4 plate, and a reflecting plate are appropriately set.

An overview of the driving method is, for example, the dart line 1a.

When an image signal is applied to 1 a/ and a driving voltage is scanned and applied to source lines 3 and 3' (only while a signal is being input to the dirt line), one of the intersections of these electrodes Source (3,3') drain (4,4///
) becomes electrically conductive, an electric field is generated between the drain electrode and the counter electrode 8, and the arrangement state of liquid crystal molecules in the liquid crystal layer 11 changes, thereby producing a display.

In such devices, a common method for performing a shadow display is to form a color filter on a counter electrode substrate that faces a substrate on which a driving semiconductor array is provided.

However, a color display device having such a configuration has various problems. That is, since the liquid crystal layer is sandwiched between the substrate on which the driving semiconductor array is formed and the counter electrode substrate on which the color filter is formed, there is a drawback that parallax occurs when this color display device is viewed from an angle.

Furthermore, when bonding the substrate on which the driving semiconductor array is formed and the counter electrode substrate on which the color filter is formed using an adhesive, each voltage of the driving semiconductor array and the color filter are adjusted within ±5 μm. Although precise alignment is necessary, it is not easy to perform precise alignment and bonding.
This has the disadvantage that positional deviations often occur, causing color unevenness in color display devices.

The present invention has been made in view of the above points, and a main object of the present invention is to provide a color display device in which a thin film transistor array and a color filter are integrated.

Another purpose is to eliminate the need for precise alignment between the color filter of the counter electrode substrate on which electrodes are formed and the electrodes of the driving semiconductor array when manufacturing a color display device.

Another object of the present invention is to eliminate parallax when a color display device is viewed from an angle.

A color display device of the present invention that achieves the above object includes a first substrate provided with a thin film transistor array having a plurality of electrodes serving as display element units, and a second substrate provided with a counter electrode. In a display device that displays by electro-optical changes occurring between these substrates, a color filter having only a dye layer formed by vapor phase deposition prior to the formation of the thin film transistor array as a color element is disposed on the substrate. It is characterized by the fact that it has been established.

The color filter used in the present invention is preferably made by a method of forming a dye layer using a thin film of dye deposited by vacuum evaporation, and the patterning of the dye layer is carried out using a resist mask (hereinafter referred to as an under mask) under the dye layer to be removed. It is preferable to use a so-called per-perspective etching method (or lift-off method) in which the underlying undermask is removed from the substrate, thereby physically removing the overlying dye layer at the same time.

In this method, after forming an undermask using a material that can be dissolved later, a vapor-deposited dye layer is provided on the undermask, and the desired pattern is then formed by dissolving the undermask. According to the reverse etching method, a pattern is formed by removing the undermask itself, so color filters can be formed on the same plane on the substrate.Moreover, this color filter has a simple structure of only a dye layer. An N-film transistor array can be formed on the color filter.

In this case, dyes or pigments that can be sublimed or vapor-deposited are used in the dye layer used in the present invention, such as phthalocyanine pigments, nanthole pigments, indathrene dyes, and oil-soluble didisperse dyes.

The present invention will be described below with reference to FIGS. 3, 4, and 5.

FIG. 3 shows a 191st embodiment of a color display device according to the present invention, in which parts similar to those shown in FIGS. 1 and 2 are designated by the same reference numerals. In Figure 3,
1" and 1"' are r-) electrodes, i and 2/l/ are thin film semiconductors, 3 and 3' are source lines, 4" and 4
``' is a drain electrode that functions as a display element unit, 5 is an insulating layer, 7 and S are substrates such as glass, 8 is a counter electrode, 1
1 is a liquid crystal layer, and 12 and 13 are polarizing plates. Each part of the display surface shown in FIG. 3 is constructed of the same materials as described in connection with FIGS. 1 and 2, and performs a photoindication effect through the same electro-optical changes as described above.

In the color display device of the present invention, a color filter having only a dye layer formed by vapor deposition prior to the formation of the thin film transistor array as a color element is provided on the substrate S.
formed on top. In the illustrated embodiment, this color filter consists of four turns of three colors: a blue element 6, a green element 6', and a red element 6''.

Each of these color elements is connected to an element electrode, that is, a drain electrode 4.
It is formed under ", 4"' and serves as a color filter corresponding to the element electrode. A color display device is constructed by forming a thin film transistor array on these color elements and sandwiching a liquid crystal layer 11 between this and a counter substrate 7 on which a counter electrode is formed.

FIG. 4 shows a modification of the display device of the present invention, in which a color filter consisting of color elements 6, 6', 6" and dart electrodes 1", 1' in the configuration shown in FIG. 3 are formed on the same plane. By doing so, the thickness of the thin film transistor array is reduced and the structure is made flat. In other respects, what is shown in FIG. 4 is the same as what is shown in FIG.

Next, with reference to FIGS. 5(a) to 5(,), a process for creating a color filter in a color display device according to the present invention will be described.

First, a positive resist for deep ultraviolet light (for example,
0DUR1013 manufactured by Tokyo Ohka Co., Ltd.) was applied by rotation using a spinner. After drying, prebaking at 120°C for 20 minutes. Next, the prescribed 1? with far ultraviolet light? Expose and develop in a turn shape.

Through the above steps, the amplifier mask 14 shown in FIG. 5(a) is formed on the substrate S. Next, Figure 5 (b
) The entire surface is irradiated with deep ultraviolet light.

Then, as shown in FIG. 5(c), a blue vapor-deposited dye layer 15 is formed on the undermask 14 to a thickness of 30,001 mm by vacuum vapor deposition of Ni phthalocyanine.

Then, the undermask below the dye layer 15 is immersed in a resist developer. Removal of the undermask simultaneously removes the deposited dye layer 15 above it.

In this way, the blue element 6 is formed as shown in FIG. 5(d).

On the blue element 6 formed in FIG. 5(d), a green dye Toshite Pb phthalocyanine and a red dye Lionogun Magenta R (manufactured by Toyo Ink) are used, respectively, as shown in FIG. 5(a).
By repeating the same process as in ~(d) (J+'4'), a color filter consisting of a three-color pattern of blue element 6, green element 6', and red element 6'' as shown in FIG. 5(e), for example, can be obtained. is formed on the substrate S.

After forming a thin film transistor layer on the color filter consisting of the color elements 6, 6' and 6'', a liquid crystal layer 11 is sandwiched between a counter substrate 7 on which a counter electrode is formed, and the result is as shown in FIG. 3 or 4. A color display device is constructed as shown.

In the color display device shown in FIGS. 3 and 4, each color element is formed under the element electrodes 4", 4"', and serves as a color filter corresponding to the element electrodes 4", 4"'. Therefore, in this example, it is R (red).

Color display is performed using the three primary colors of G (green) and B (blue). This configuration has the advantage that parallax does not occur because the color filter is formed in close contact with the electrode of the display section.

Furthermore, since the color filter is integrated with the thin film transistor array, there is an advantage that alignment is not required when bonding the substrate S and the substrate 7 together.

In the present invention, in addition to the liquid crystal used in the embodiment above, EC (electrochromy), EL (electroluminescence), etc. can also be used as the electro-optic modulation material. As the liquid crystal, a single liquid crystal or a mixture of liquid crystals exhibiting nematic, cholesteric, or smectic properties are used depending on the display operation mode. These display operation modes may be of any type, such as so-called TN, DAP, DSM, HAN, dust host, phase change, etc., and depending on the selected mode and display effect, suitable optical detection means (λ/4 plate , a polarizing plate 2, a reflecting plate, a lens, and an illumination device) can be appropriately selected and added to the device of the present invention.

The diagonal display device according to the present invention has good drive performance, productivity, and reliability, and has a high pixel density, and can be used as a small display device such as a television,
Applicable to video camera monitors, etc.

As explained above, according to the present invention, color display is achieved by using a color display device in which a transistor array is provided on a substrate on which a color filter having only a dye layer formed by vapor deposition as each color element is formed. When manufacturing the device, there is no need for precise alignment between the color filter of the counter substrate on which electrodes are formed and the electrodes of the thin film transistor array, and there are advantages such as no parallax when viewed from an angle.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view showing a part of a substrate having a semiconductor drive circuit in a conventional display device, and FIG. 1(b)
is a plan view thereof, FIG. 2 is a partial sectional view of a display device having the substrate shown in FIGS. 1 (&) and (b), and FIG. 3 is a sectional view showing an embodiment of a color display device according to the present invention. FIG. 4 is a sectional view showing another embodiment of the present invention, and FIG. 5(a)-(
-) is an explanatory diagram showing an example of the process of creating a color filter in the color display device of the present invention. In the figure, 1&11a'lla", 1m"', 1a""...r-
) wire 1.1', 1", 1"'... dirt, electrode 2.2
', 2"+ 2"'...Semiconductor 3.3', 3", 3"
', 3"...source 4.4', 4" 4///...
- Drain electrode 5.5', 9. I...Insulating film 6...Blue element 6'...Green element 6''...Red element 7.S...Substrate 8...ti!II 10...
・Spacer 11...Liquid crystal layer 12.13...Polarizing plate 14...Undermask 15...Vapour-deposited dye layer Fig. 5

Claims (1)

[Claims] It has a first substrate provided with a thin film transistor array having a plurality of electrodes serving as display element units, and a second substrate provided with a counter electrode, and displays by electro-optical changes occurring between these substrates. 1. A color display device comprising: a color filter having, as a color element, only a dye layer formed by vapor deposition prior to the formation of the thin film transistor array; provided on a substrate.