JP3246783B2 - Method for manufacturing antiferroelectric liquid crystal display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a process for the preparation of the anti-ferroelectric liquid crystal display panel, in particular by using an antiferroelectric liquid crystal panel, to create a panel with a good reflective layer efficient, large panels But there is no shadow of the display screen, and anti-ferroelectric liquid crystal display panel obtained a characteristic that does not impair viewing angle
And a method for producing the same.

[0002]

2. Description of the Related Art A liquid crystal panel using an antiferroelectric liquid crystal,
This antiferroelectric liquid crystal display device is proposed by Nippondenso Co., Ltd. and Showa Shell Sekiyu KK in Japanese Patent Application Laid-Open No. 2-173724, having a wide viewing angle, capable of high-speed response, and multiplex characteristics. Research has been conducted energetically since it was reported to be good.

An antiferroelectric liquid crystal has a hysteresis characteristic in a transmitted light quantity-voltage characteristic as shown in a graph of FIG. Thus, when a certain pulse wave is applied to the liquid crystal molecules, the first stable state (ferroelectric state) is selected when the product of the pulse width and the voltage value exceeds the threshold value. The second stable state (ferroelectric state) is selected depending on the polarity of the applied voltage.

From the first state and the second state, when the absolute value of the product of the pulse width and the voltage value is lower than a certain threshold value, a third stable state (reverse (Ferroelectric state) is selected.

FIG. 10 is a plan view showing an electrode configuration of a matrix type liquid crystal panel including the antiferroelectric liquid crystal.

As shown in FIG. 10, scanning electrodes Y1 to Y1
28, a selection voltage is sequentially and periodically applied to the signal electrodes X1 to X1.
X160 adopts a time-division drive in which a predetermined information signal is applied in parallel in synchronization with the scanning electrode signal, and the liquid crystal molecules of the selected pixel are switched according to the display information.

Various methods have been proposed as a method of time division driving. FIG. 11 and FIG.
According to the driving method disclosed in Japanese Unexamined Patent Publication No. 73724, two frames are written in order to write one screen. The relationship is symmetrical, and thereby, AC is achieved by writing two frames.

FIG. 11 shows a change in the voltage waveform and the transmittance of the pixel when the "ON" state is set, and FIG. 12 shows a change in the pixel transmittance when the "OFF" state is set.

The signal applied to the scanning electrode has three phases as shown in FIGS. 11 and 12, and is always reset to the "off" state (antiferroelectric state) once in the first phase. 2
In the phase, whether the state in the first phase is maintained and the “on” state (ferroelectric state) is set in the third phase is selected.

In the case of FIG. 11, since the third phase exceeds the threshold voltage for setting the ferroelectric state, it is set to the "on" state (ferroelectric state). The "off" state (antiferroelectric state) is maintained so as not to exceed the threshold voltage.

[0011] In the case of using such a display element to perform transmissive display, a backlight is inevitably used, so that power consumption is inevitably increased. Also, when creating a reflection type, the contrast ratio is reduced.

FIG. 8 is a sectional view showing a configuration of a reflection type antiferroelectric liquid crystal display panel according to the prior art. The outside of the second substrate 12 and the first substrate which is the lower substrate of the liquid crystal display panel
Of the polarizing plate 14 and the reflecting plate 1
3 and a polarizing plate 14 are provided.

As shown in FIG. 8, in a conventional antiferroelectric liquid crystal display panel, a reflection plate 13 and a polarization plate 14 are arranged apart from a first substrate 11.

[0014]

Therefore, the incident light 22
On the other hand, when the reflected light 23 passes through the thickness of the air layer or the glass layer of the first substrate 11 before entering the observer's eyes, the optical path is shifted due to the difference in the refractive index. As a result, a ghost may occur with an adjacent pixel, or a shadow may be generated because the pixel portion is apart from the reflection image, thereby causing deterioration in display quality.

Further, the antiferroelectric liquid crystal display panel has a high viewing angle characteristic because the contrast ratio has almost no difference between up, down, left and right.

However, for the above reason, there is a disadvantage that the sharpness and the viewing angle of the image are reduced by the shadow of the selected pixel area and the reflection image generated by this display, and the display quality is deteriorated.

An object of the present invention, by which to solve the above-mentioned problem, and provides a manufacturing method of the antiferroelectric panel is no reduction in the sharpness and the viewing angle of the image by the reflection type antiferroelectric liquid crystal panel is there.

[0018]

Means for Solving the Problems] To achieve the above object antiferroelectric manufacturing how the liquid crystal display panel of the present invention employs the following means.

In the method of manufacturing an antiferroelectric liquid crystal display panel according to the present invention, the first substrate has a step of forming a fine uneven surface on its surface and forming a reflective film, and a step of providing a resin film on the reflective film. Providing a polarizing film on the resin film, further forming a resin film on the polarizing film, pressure and heat treatment using a release plate to cure the resin film, the transparent electrode and the orientation control film Forming a second substrate, the second substrate including a step of forming a transparent electrode and an orientation control film, further arranging a gap material between the first substrate and the second substrate, The method includes a step of bonding the first substrate and the second substrate, and a step of injecting an antiferroelectric liquid crystal between the first substrate and the second substrate.

[Operation] After the reflection film is formed on the first substrate, a thermosetting resin film is thinly applied and a polarizing film is placed thereon. The polarizing film has a structure of iodine and polyvinyl alcohol, a direct dye and polyvinyl alcohol, and a polyethylene structure. After the resin film is dropped on the deflection film, the resin surface is mirror-finished from above, and the resin film is thermally cured while being pressed using a flat substrate to which a release agent is thinly applied.

As a result, the distance between the reflective film and the display pixels becomes extremely small, and it is possible to produce a reflective substrate that does not cause shadows on the display screen.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and manufacturing method of an antiferroelectric liquid crystal display panel according to an embodiment of the present invention will be described below with reference to the drawings. First, the structure of the antiferroelectric liquid crystal display panel of the present invention will be described with reference to FIG.

As shown in FIG. 1, a reflection film 13 is provided on a first substrate 11 having a fine uneven surface. The reflection film 13
Is provided with a polarizing film 14 sandwiched between resin films 15.

Further, the first substrate 11 has a transparent electrode 16 formed on the resin film 15 and further has an alignment control film 17 on the transparent electrode 16.

The second substrate 12 includes a transparent electrode 16, an orientation control film 17 provided on the transparent electrode 16, and the second substrate 1.
2 and a polarizing film 14 provided outside.

Further, a sealing material 18 provided between the first substrate 11 and the second substrate 12, a gap material 19, and an antiferroelectric liquid crystal 20 are provided.

With the structure shown in FIG. 1, incident light 22 passes through the inside of the antiferroelectric liquid crystal display panel, and reflected light 2
When the light exits as 3, the distance between the reflective film 13 and the display pixel becomes extremely small as shown in FIG. 1 and there is no reflected light passing through the adjacent pixels, and the distance between the display portion and its shadow is short, so that the ghost phenomenon occurs. Does not occur, and the dependence of the viewing angle is reduced.

Next, a manufacturing method for forming the antiferroelectric liquid crystal display panel structure shown in FIG. 1 will be described with reference to the sectional views of FIGS.

First, as shown in FIG. 2, one side of the first substrate 11 made of glass is subjected to honing processing or the like, and the surface of the first substrate 11 is roughened to form a fine uneven surface.

Thereafter, a reflective film 13 made of aluminum or silver is formed to a thickness of about 200 nm to 300 nm by a vacuum evaporation method.

As shown in FIG. 3, the resin film 1 made of a liquid containing 100% of resin, for example, a photosensitive resin or an epoxy resin, is formed on the reflection film 13 thus formed.
5 is defoamed to form an appropriate amount.

Further, a thickness of 3
A 0 μm polarizing film 14 is overlaid. Starting from a polyvinyl alcohol film having a thickness of 75 μm, the polarizing film 14 is immersed and swelled in an aqueous solution layer of sodium sulfate and boric acid and an aqueous solution layer of boric acid, and is wet-stretched about 4 times. It is formed by dipping iodine in the film by dipping iodine into the iodine aqueous solution layer and then drying with warm air.

Thereafter, as shown in FIG. 4, the same liquid resin film 15 as described with reference to FIG. 3 is formed on the polarizing plate 14 by defoaming.

Thereafter, as shown in FIG.
5 using a press with a parallel reference using a mirror-like release plate 21 having a good flatness on which a coating of a compound having a low surface energy, for example, a silicone resin or a fluorine resin is formed. Pressurization is performed as shown in FIG.

In this embodiment, a glass plate having a thickness of 5 mm or more is mirror-finished by polishing, and a metal such as chromium is formed by a vacuum evaporation method in order to obtain flatness.

Thereafter, the resin film 15 is caused to undergo a curing reaction by light energy or heat energy while being pressed by a press, and is brought into a solid state.

At this time, when an epoxy resin or the like was used as the resin film 15, the degree of polarization of the polarizing film 16 did not deteriorate by curing at a temperature of 100 ° C. or less.

In the case of a direct dye and a polyvinyl alcohol-based or polyene structure-based film serving as a base film, the polarizing film 14 is used.
Did not deteriorate.

After that, a transparent electrode 16 is formed on the first substrate 11 having the polarizing film 14 therein by a low-temperature sputtering method, and an appropriate annealing treatment is performed in an oxygen atmosphere or as it is to lower the resistance value of the transparent electrode 16. .

Thereafter, the first substrate 11 is subjected to a photo-etching process, and the transparent electrode 16 is patterned. After that, an alignment control film 17 is formed and an alignment process is performed.

Similarly, on the second substrate 12, a transparent electrode 16 and an orientation control film 17 are formed, and an orientation process is performed.

At this time, the orientation control film 17 was obtained by baking a solvent-volatile polyimide at a temperature of 100 ° C. for 2 hours.

Thereafter, using a thermosetting resin or a photosensitive resin adhesive, seal printing is performed on the periphery of the transparent electrode 16 to form a seal material 18, and the particle size is 1.5 μm.
Scattered plastic beads as gap material 19,
After the first substrate 11 and the second substrate 12 are overlapped, the sealing material 18 is thermally cured or photocured, and then an antiferroelectric liquid crystal 20 is injected to form a liquid crystal panel.

At this time, the pressing force is 2.0 kg / cm ²
The above pressure is applied to crush the gap material 19 made of plastic beads so as to have a size of 1.0 μm or less.

Thereafter, the first substrate 11 and the second substrate 12
The value of the birefringence of the antiferroelectric liquid crystal 20 injected between (
In the case of n), a reflection type antiferroelectric liquid crystal display device is obtained by injecting one having a value of 0.1 to 0.06.

When a thermosetting adhesive is used as the sealant 18, it is preferable to use a thermosetting adhesive at a temperature of 120 ° C. or less to prevent the polarizing film 14 from being thermally degraded.

As a result of a reliability test of the antiferroelectric liquid crystal panel having the above structure, a heat resistance test at 80 ° C. for 20 days was performed.
Both the humidity resistance test at -90% for 20 days was stable, the polarizing film 14 hardly deteriorated, and no abnormalities in the leak current value were observed.

[0048]

As is apparent from the above description, according to the present invention, in a reflection type panel of antiferroelectric liquid crystal,
Even on a large screen, there is no shadow of the display pixels, and there is no reduction in the viewing angle of the reflective panel, and a panel with good display images can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of an antiferroelectric liquid crystal display panel of the present invention.

FIG. 2 is a cross-sectional view illustrating a method for manufacturing an antiferroelectric liquid crystal display panel of the present invention.

FIG. 3 is a cross-sectional view illustrating a method for manufacturing an antiferroelectric liquid crystal display panel of the present invention.

FIG. 4 is a cross-sectional view illustrating a method for manufacturing an antiferroelectric liquid crystal display panel of the present invention.

FIG. 5 is a cross-sectional view illustrating a method for manufacturing an antiferroelectric liquid crystal display panel of the present invention.

FIG. 6 is a cross-sectional view illustrating a method for manufacturing an antiferroelectric liquid crystal display panel of the present invention.

FIG. 7 is a cross-sectional view illustrating a method for manufacturing an antiferroelectric liquid crystal display panel of the present invention.

FIG. 8 is a cross-sectional view showing a structure of a conventional antiferroelectric liquid crystal display panel.

FIG. 9 is a graph showing a hysteresis curve in the voltage and transmittance characteristics of the antiferroelectric liquid crystal.

FIG. 10 is a plan view showing a matrix configuration of electrodes in an antiferroelectric liquid crystal display panel.

FIG. 11 is a waveform chart showing a driving method of the antiferroelectric liquid crystal display device.

FIG. 12 is a waveform chart showing a driving method of the antiferroelectric liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 11 first substrate 12 second substrate 13 reflective film 14 polarizing film 15 resin film 16 transparent electrode 19 gap material 20 antiferroelectric liquid crystal 21 release plate 22 incident light 23 outgoing light

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/1333 505 G02F 1/13 101 G02F 1/1335 520

Claims (1)

(57) [Claims] A step of forming a fine uneven surface on a surface of the first substrate and forming a reflective film; providing a resin film on the reflective film; providing a polarizing film on the resin film; A step of forming a resin film on the polarizing film, a step of applying pressure and heat using a release plate to cure the resin film, and a step of forming a transparent electrode and an orientation control film. The method further comprises the step of forming a transparent electrode and an orientation control film, further comprising disposing a gap material between the first substrate and the second substrate; Bonding an antiferroelectric liquid crystal between the first substrate and the second substrate, and manufacturing the antiferroelectric liquid crystal display panel. .