JPH10170900A - Polymer film liquid crystal display and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the display unevenness of a polymer film LCD and to sufficiently reduce the stress applied to a transparent electrode. SOLUTION: The polymer film LCD has an upper polymer film substrate 35 where a transparent electrode 27 is printed, a lower polymer film substrate 36 where a transparent electrode 22 is printed, the liquid crystal 29 interposed between those upper polymer film substrate 35 and lower polymer film substrate 36, and spacers 24 and sealants 25, which are scattered uniformly. The sealants 25 are formed at parts other than the display part through screen printing in addition to the edge part on the lower polymer film substrate 36. Therefore, the sealants 25 are interposed between the upper polymer film substrate 35 and lower polymer film substrate 36 in the LCD panel in addition to the spacers 24, so the thickness of the liquid crystal 29 is controlled to a prescribed value with high precision and the variation in the substrate gap is made small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer film liquid crystal display used for portable equipment and the like and a method of manufacturing the same, and more particularly to a polymer film liquid crystal display capable of reducing display unevenness of a liquid crystal display panel and a method of manufacturing the same. In the specification of the present application, the liquid crystal display is hereinafter referred to as LCD.

[0002]

2. Description of the Related Art Conventional LCDs include an LCD using a glass substrate and an LCD using a polymer film substrate. In a polymer film LCD, since the thickness of the polymer film substrate is small, an LCD in which a polarizing plate, a reflection plate, an illumination light source, or the like is incorporated in the polymer film substrate.
The overall size can be reduced. Also, polymer film substrates have a lower specific gravity than glass substrates,
The weight can be reduced. Furthermore, since the polymer film substrate does not break like the glass substrate, the impact resistance can be improved. Therefore, the market is expected to expand due to demand for portable information terminals and card-type displays.

FIG. 4 is a sectional view showing the structure of a conventional polymer film LCD, and FIG. 5 is a plan view thereof. The polymer film LCD has an upper polymer film substrate 35
A lower polymer film substrate 36, and a sealant 25 interposed between the upper polymer film substrate 35 and the lower polymer film substrate 36 at the periphery thereof.
It has a liquid crystal 29 injected into a space between the substrates 35 and 36 surrounded by the sealant 25. The upper polymer film substrate 35 and the lower polymer film substrate 36 are respectively
Polymer film substrates 26, 21 and transparent electrodes 27, 2 made of ITO formed on inner surfaces (panel surfaces) thereof
The polarizing plates 32 and 33 are laminated on the outer surfaces of the upper polymer film substrate 35 and the lower polymer film substrate 36, respectively. Transparent electrode 27
Are formed in parallel on the upper polymer film substrate 35. The transparent electrode 22 is arranged on the lower polymer film substrate 36 in a direction orthogonal to the transparent electrode 27 on the panel surface. In addition, the inner surfaces of the upper polymer film substrate 35 and the lower polymer film substrate 36 are respectively provided with alignment films 28, 2 so as to cover the transparent electrodes.
3 are formed. The upper polymer film substrate 35 and the lower polymer film substrate 36 are arranged with their panel surfaces facing each other. A transparent spherical spacer 24 made of plastic or the like is provided in the liquid crystal 29.
, And a sealant 25 is arranged around the outside of the liquid crystal 29.

FIGS. 6 to 11 are sectional views showing a method of manufacturing a conventional polymer film LCD in the order of steps. First,
As shown in FIG. 6, ITO (indium tin oxide)
By etching the ITO film of the polymer film with a film, an IT surface is formed on the circuit surface on the polymer film substrate 26.
A substrate 35 is obtained by forming a transparent electrode 27 made of O. Next, as shown in FIG. 7, a polyamide film or the like is applied on the substrate, and a rubbing process for forming a groove in the polyamide film is performed to form an alignment film 28 on the substrate. This alignment film is for aligning the liquid crystal. In addition to the upper polymer film substrate 35 on which the transparent electrode 27 is formed, the circuit surface on the polymer film
Is formed, and an alignment film 23 is further formed on the transparent electrode 22 to manufacture a lower polymer film substrate 36. Then, the alignment films on the upper polymer film substrate 35 and the lower polymer film substrate 36 are removed by photoetching at the edge where the seal portion 25 is arranged, or removed by a plasma ashing device.

[0005] Thereafter, as shown in FIG. 8, the spacers 24 are sprayed on the lower polymer film substrate 36,
As shown in FIG. 9, a sealant 25 is applied to the edge of the substrate. Then, the spacer 24 and the sealant 25 are overlapped on the lower polymer film substrate 36 with the circuit surfaces of the upper polymer film substrate 35 facing each other. As a result, the two substrates are bonded together with the spacer 24 and the sealant 25 interposed therebetween.

Then, as shown in FIG. 10, a liquid crystal 29 is injected into the LCD panel. Next, as shown in FIG. 11, polarizers 32 and 33 are provided on outer surfaces of the upper polymer film substrate 35 and the lower polymer film substrate 36, respectively.
Is attached. Thereby, a polymer film LCD is manufactured.

In the polymer film LCD configured as described above, the timing of an electric signal between the transparent electrode 27 (common electrode) of the upper polymer film substrate 35 and the transparent electrode 22 (segment electrode) of the lower polymer film substrate 36 is controlled. In addition, by selectively applying a voltage, a target pixel is turned on, and an image is displayed on the LCD panel surface.

Conventionally, as a transparent electrode of the above-mentioned polymer film LCD, a TiOx (x <2) film and an alignment film are sequentially formed on an indium oxide transparent electrode formed on a substrate in order to improve the contrast and improve the display function. There has been proposed a structure of a liquid crystal display device which is stabilized (Japanese Utility Model Application Laid-Open No. 57-2).
No. 3518). Further, a multilayer circuit board has been proposed in which a conductive layer in which a titanium thin layer, a copper thin layer, a palladium thin layer, and a metal layer are sequentially formed on an alumina substrate to improve adhesion between the substrate and a circuit has been proposed. (JP-A-54-66458).

[0009]

However, in the conventional polymer film LCD, the thickness of the liquid crystal 29 on the LCD panel surface 41 is controlled only by the point contact between the spacer 24 and the substrate. 41 whole liquid crystal 2
It is difficult to reliably set the thickness of No. 9 to a predetermined amount.
There is a problem that display unevenness occurs in the D panel surface 41. That is, when the thickness of the liquid crystal 29 is larger than a predetermined amount, a red mode occurs in which the LCD panel surface 41 is entirely red. When the thickness of the liquid crystal 29 is smaller than the predetermined amount, a red mode occurs. A blue mode in which 41 becomes blue occurs. Also, when a load or external stress due to bending or the like is applied to the polymer film LCD,
Since the load applied to the transparent electrode cannot be sufficiently dispersed only by the spacer 24, there is a problem that the stress applied to the transparent electrode increases.

[0010] The present invention has been made in view of the above problems, and a polymer capable of preventing display unevenness of a polymer film liquid crystal display and sufficiently reducing stress applied to a transparent electrode. An object of the present invention is to provide a film liquid crystal display and a method for manufacturing the same.

[0011]

According to the present invention, there is provided a polymer film liquid crystal display comprising: a first polymer film substrate having a transparent electrode formed on a polymer film substrate and an alignment film formed so as to cover the transparent electrode; A second polymer film substrate on which a transparent electrode is formed on a film substrate, an alignment film is formed so as to cover the transparent electrode, and the first polymer film substrate and a panel surface thereof are arranged to face each other; A plurality of spacers interposed between the first polymer film substrate and the second polymer film substrate to control a distance between the substrates;
In addition to the edge portions of the polymer film substrate and the second polymer film substrate, at least a part other than the display portion has a sealing agent interposed between the substrates.

The method of manufacturing a polymer film liquid crystal display according to the present invention comprises the steps of: forming a first liquid crystal display substrate by spraying a plurality of spacers on a first polymer film substrate; Producing a second liquid crystal display substrate by forming a sealant on at least a portion other than the display portion and the display portion by coating or the like; and connecting the first liquid crystal display substrate and the second liquid crystal display substrate to each other with their panel surfaces mutually. Curing the sealant after facing and bonding.

In the present invention, in addition to the edge between the first polymer film substrate and the second polymer film substrate,
At least a part other than the display part is provided with a sealant. Therefore, in addition to the point contact between the spacer and the substrate, the thickness of the liquid crystal layer is controlled by the surface contact between the sealant and the substrate, so that the thickness of the liquid crystal layer can be reliably set to a predetermined value. . Further, even when a load due to bending or the like is applied to the polymer film LCD, the area for fixing the polymer film by the sealant is large, so that the fluctuation of the substrate gap can be reduced.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be specifically described with reference to the accompanying drawings. FIG. 1 is a sectional view showing a structure of a polymer film LCD according to an embodiment of the present invention, and FIG. 2 is a plan view thereof. This embodiment is different from the conventional polymer film LCD shown in FIG.
In addition to the edges of the substrates 35, 36, there is no alignment film between the upper polymer film substrate 35 and the lower polymer film substrate 36 in portions other than the display section 40 of the LCD, and the In other words, the sealing agent 25 is interposed, and the other configuration is the same as that of the conventional example shown in FIG. Therefore, in FIGS. 1 and 2, the same components as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIGS. 3A to 3D are sectional views showing a method of manufacturing the polymer film LCD of this embodiment in the order of steps. First, as shown in FIG. 3A, on the upper polymer film substrate 35 shown in FIG. 7, in addition to the edge of the substrate 35, the portion where the sealant is disposed (the portion other than the display unit 40) is provided. The alignment film 28 is removed by photoetching or plasma ashing. After that, spacers 24 are scattered on the alignment film 28 to manufacture the upper liquid crystal display substrate 10. At this time, the spacers 24 are sprayed at a rate of 200 to 500 pieces / mm ² using a wet or dry spacer sprayer. Further, separately from the substrate 35 on which the transparent electrode 27 is formed, an IT
A transparent electrode 22 made of O is formed.
After the alignment film 23 is formed thereon, the lower polymer film substrate 36 is manufactured by removing the alignment film 23 other than the display unit 40 in addition to the edge of the substrate 21.

Next, as shown in FIG. 3B, a sealant 25 is applied to the edge of the substrate 36 and to portions other than the display section 40.
Is screen printed to produce a lower liquid crystal display substrate 11. The sealant 25 may be applied by a dispenser instead of screen printing. The sealant 25 is a thermosetting epoxy resin or a UV (ultraviolet ray) curable epoxy resin, and has flexibility and does not decompose liquid crystal. Thereafter, as shown in FIG. 3C, the upper liquid crystal display substrate 10 and the lower liquid crystal display substrate 11 are overlapped so that the panel surfaces on which the transparent electrodes are formed face each other. Thereby, the upper liquid crystal display substrate 10 and the lower liquid crystal display substrate 11 sandwich the spacer 24 and the sealant 25 therebetween,
Pasted. Then, the substrates 10 and 11 are heated or U
V irradiation and the thickness of the sealant 25 is
Are pressed together to match the thickness of

Thereafter, as shown in FIG.
The liquid crystal 29 is injected into the panel, and the outer surfaces of the upper liquid crystal display substrate 10 and the lower liquid crystal display substrate 11 are
The polarizing plates 32 and 33 are attached, respectively. Thereby, a polymer film LCD is manufactured.

In the polymer film LCD according to the present embodiment thus constructed, the upper polymer film substrate 35 and the lower polymer film substrate 36 other than the display section 40 are provided.
And a sealing agent 25 is interposed between the
The thickness of the liquid crystal 29 is controlled by the surface contact between the sealant 25 and the substrate in addition to the point contact between the liquid crystal 2 and the substrate.
9 can be controlled to a predetermined amount with high precision. Further, even if a load or external stress due to bending or the like is applied to the polymer film LCD, the sealant 25 fixes the polymer film substrate, so that the fluctuation of the substrate gap can be reduced.

[0019]

As described above, according to the present invention,
In addition to the edge between the first polymer film substrate and the second polymer film substrate, at least a portion other than the display portion is provided with a sealant, so that the thickness of the liquid crystal layer can be accurately adjusted to a predetermined value. Can be controlled. Therefore, it is possible to prevent display unevenness occurring in the LCD panel surface. Further, even if a load or external stress due to bending or the like is applied to the polymer film LCD, the sealant fixes the gap between the polymer film substrates, so that the fluctuation of the gap between the substrates can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a structure of a polymer film liquid crystal display according to an embodiment of the present invention.

FIG. 2 is a schematic front view showing a structure of a polymer film liquid crystal display according to an example of the present invention.

FIG. 3 is a cross-sectional view illustrating a method for manufacturing a polymer film liquid crystal display according to an embodiment of the present invention in the order of steps.

FIG. 4 is a schematic sectional view showing the structure of a conventional polymer film liquid crystal display.

FIG. 5 is a schematic front view showing the structure of a conventional polymer film liquid crystal display.

FIG. 6 is a sectional view showing one step of a conventional method for manufacturing a polymer film liquid crystal display.

FIG. 7 is a sectional view showing a step subsequent to that of FIG. 6;

FIG. 8 is a sectional view showing a step subsequent to that of FIG. 7;

FIG. 9 is a sectional view showing a step subsequent to that of FIG. 8;

FIG. 10 is a sectional view showing a step subsequent to that of FIG. 9;

FIG. 11 is a sectional view showing a step subsequent to that of FIG. 10;

[Explanation of symbols]

 LCD substrate 21, 26, 35, 36; polymer film substrate 22, 27; transparent electrode 23, 28; alignment film 24; spacer 25; sealant 29; liquid crystal 32, 33; ; LCD panel surface

Claims (2)

[Claims] 1. A first polymer film substrate having a transparent electrode formed on a polymer film substrate and an alignment film formed to cover the transparent electrode, and a transparent electrode formed on the polymer film substrate to cover the transparent electrode. An orientation film is formed as described above, and the first polymer film substrate and a second polymer film substrate arranged with their panel surfaces facing each other, and between the first polymer film substrate and the second polymer film substrate. A plurality of spacers interposed so as to control a substrate gap, interposed between the substrates at least at a part other than the display part in addition to the edges of the first polymer film substrate and the second polymer film substrate; A polymer film liquid crystal display comprising: a sealing agent. 2. A step of forming a first liquid crystal display substrate by spraying a plurality of spacers on a first polymer film substrate, and sealing at least a part other than an edge portion and a display portion on the second polymer film substrate. Forming a second liquid crystal display substrate by applying an agent or the like, and bonding the first liquid crystal display substrate and the second liquid crystal display substrate with their panel surfaces facing each other, and then applying the sealing agent. Curing the polymer film liquid crystal display.