JPH10197857A - Liquid crystal element and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form an insulating layer having thickness distribution in a picture element at low cost by exposing high molecular material embedded between auxiliary electrodes by using a photomask having light transmissivity gradient. SOLUTION: The auxiliary electrode 6 is formed of Al or Mo on a glass base plate 8. Photosensitive polyamide resin is uniformly applied as photosensitive resin 9' and prebaked. Next, the resin 9' is irradiated with ultraviolet rays 11 through the photomask 10 so as to be exposed. The photomask 10 has concentration gradient where light shielding rate is consecutively changed on a plane corresponding to the picture element. Developing processing is performed so as to form a sawtoothed insulating layer 9 in a state where the resin 9' is left to have shape in accordance with the concentration gradient of the photomask 10 on the plate 8. By forming and patterning an ITO film on the insulating layer 9, a scanning electrode 4 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device and a method for manufacturing a liquid crystal device, and more particularly to a ferroelectric liquid crystal (hereinafter referred to as "FL").
C ").

[0002]

BACKGROUND OF THE INVENTION Clark and Lagerwall are AppliedPhysic.
s Letters, Vol. 36, No. 11, issued June 1, 1980; 899-901, JP-A-56-10
No. 7216, U.S. Pat.
U.S. Pat. No. 4,563,059 discloses surface stabilized F
LC (Surface-Stabilized-fer
roeelectric-liquid crystal
The bistable FLC device according to 1) was identified. This bistable FLC device has a pair of pairs set at a distance small enough to control the formation of a helical array structure of liquid crystal molecules in a chiral smectic C phase (Smc * phase), an H phase (SmH * phase) or the like in a bulk state. Liquid crystal between the substrates of
In addition, this is realized by arranging in one direction vertical molecular layers organized by a plurality of liquid crystal molecules.

As shown in Japanese Patent Application Laid-Open No. 61-94023, a liquid crystal device using such an FLC is formed on two inner surfaces while maintaining a cell gap of about 1 to 3 μm. It is known that a transparent electrode is formed and FLC is injected into a liquid crystal cell formed by facing glass substrates that have been subjected to an alignment treatment.

[0004] The characteristics of this FLC element are as follows.
Has a spontaneous polarization, so that the coupling force between the external electric field and the spontaneous polarization can be used for switching. Also, since the growth axis direction of the FLC molecule corresponds to the polarization direction of the spontaneous polarization one-to-one, the polarity of the external electric field is Switching.

That is, in the state of the chiral smectic phase, it takes one of the first optically stable state and the second optically stable state in response to the applied electric field, and when no electric field is applied, the state becomes the same. It is expected to be widely used in fields such as a display device having a property of maintaining a state, that is, bistability, a quick response to a change in an electric field, a high speed, and a memory type display device.

On the other hand, since the FLC element generally uses chiral smectic liquid crystal (SmC *, SmH *) as described above, the liquid crystal molecule has a twisted long axis in the bulk state. The twist of the long axis of the liquid crystal molecules can be eliminated by placing the liquid crystal in a cell having a cell gap (P.213 to 234, NA Clar).
ketal, MCLC, 1983, vol. 94) A liquid crystal device having a display panel formed of such an FLC element can form an image on a display screen of large-capacity pixels by using a multiplexing driving method described in, for example, U.S. Pat. No. 4,655,561 to Kanbe et al. Can be formed. The above-described liquid crystal device can be used for a display screen of a word processor, a personal computer, a micro printer, a television, or the like.

The FLC element has two bistable states in a light transmitting and blocking state, and is mainly used as a binary (white / black) display element. However, a multi-value display, that is, a halftone display is also possible. As one of the halftone display methods, there is a method of creating an intermediate light transmission state by controlling the area ratio of a bistable state in a pixel. Hereinafter, this method (area modulation method) will be described in detail.

FIG. 8 is a diagram schematically showing the relationship between the switching pulse amplitude of the FLC element and the amount of transmitted light (rate). One-polarity single shot is applied to a cell (element) that is initially in a complete light blocking (black) state. 5 is a graph in which the amount of transmitted light I after application of a pulse is plotted as a function of the amplitude V of a single pulse.

Here, the pulse amplitude is equal to or less than the threshold value Vth (V <
In the case of (Vth), the transmission amount does not change, and the transmission state after the pulse application is the same as FIG. 9A showing the state before the application as shown in FIG. 9B. On the other hand, when the pulse amplitude exceeds the threshold value (Vth <V <Vsat), a part of the pixel transits to the other stable state, that is, the light transmission state shown in FIG. Show. When the pulse amplitude further increases and becomes equal to or higher than the saturation value Vsat (Vsat <V), all the pixels enter a light transmitting state as shown in FIG. That is, the area modulation method controls the voltage so that the pulse amplitude satisfies Vth <V <Vsat to display a halftone.

However, since the relationship between the pulse amplitude and the amount of transmitted light shown in FIG. 8 also depends on the cell thickness and the temperature, if there is a cell thickness distribution or a temperature distribution in the display panel, such a simple driving method is used. In such a case, different grayscale levels may be displayed for applied pulses having the same voltage amplitude.

FIG. 10 is a diagram for explaining this.
FIG. 9 is a graph showing the relationship between the pulse amplitude V and the amount of transmitted light I as in FIG. 8, but the relationship at different temperatures, that is, at high and low temperatures, is shown by curves H and L, respectively. That is, it is not unusual for a display (display element) having a large display size to generate a temperature distribution in the same panel (display unit). Therefore, even if an attempt is made to display a halftone at a certain voltage Vap, as shown in FIG. I ₁ ~I would be cotton connexion halftones varies in the range of up to _2, no uniform display is obtained.

What has been devised there is the "4-pulse method" proposed by the present applicant in Japanese Patent Application Laid-Open No. Hei 4-218022. In this driving method, as shown in FIGS. 11 and 12, a plurality of pulses (A, B, C, D in FIG. 12) are applied to a low threshold portion and a high threshold value portion on the same scanning line in the panel. By doing so, the same inversion area is finally obtained as shown in FIG.

The present applicant has further disclosed in Japanese Patent Application Laid-Open No. 5-158444.
As shown in Japanese Patent Publication No.
A shorter "pixel shift method" is proposed. Here, the pixel shift method is a method of inputting and selecting different scanning signals to a plurality of scanning signal lines at the same time, thereby creating a distribution of the electrolytic intensity across the plurality of scanning signal lines, and performing gradation display. .

Next, the outline of the pixel shift method will be described.

A liquid crystal cell which can be used in this pixel shift method has a distribution of threshold values in one pixel as shown in FIG. That is, in the cell 50 shown in FIG. 13, since the thickness of the FLC layer 55 between the two opposing electrodes 51 and 52 changes, the switching threshold of the FLC also has a distribution. When the voltage applied to such a pixel is increased, switching is performed sequentially from a portion having a smaller cell thickness.

FIG. 14A shows this state. In FIG. 14, T ₁ , T ₂ , and T ₃ indicate the temperatures of the observed portion in the panel. Here, the switching threshold voltage of the FLC is set to decrease as the temperature increases. Note that the relationship between the pulse amplitude and the transmittance at these three temperatures T ₁ , T ₂ , and T ₃ is shown by three curves. Next, although there are other causes of the threshold value fluctuation besides the temperature change, the mode will be described mainly using the temperature change for convenience of explanation.

[0017] As can be seen from FIG. 14 (a), the but first upon application of a voltage V ₁ at temperature T ₁ of after resetting the entire pixel to a dark state in a pixel can obtain a X% transmittance, temperature When There rises to T ₂ or T _3, the same V ₁
Is applied to the pixels, the transmittance becomes 100%, and the gradation display cannot be performed correctly. FIG.
(C) shows the inverted state of the pixel after writing at each of the above temperatures. Then, under such conditions, the written gradation information is lost due to the temperature fluctuation, so that the application range as a display element is extremely limited.

Therefore, as shown in FIG.
By performing display across two scanning signal lines S1 and S2 having pixel information, gradation display stable against temperature fluctuations can be performed.

Hereinafter, this driving method will be described in detail.

First, F having a continuous threshold distribution in a pixel
Prepare an LC cell. Here, as this liquid crystal cell,
As shown in FIG. 13, a cell having a structure in which the cell thickness in a pixel is continuously distributed can be used. Further, a configuration having a potential gradient in a pixel or a configuration having a capacitance gradient as proposed by the present applicant in Japanese Patent Application Laid-Open No. 62-125330 may be used.

In any case, by continuously distributing the threshold values in the pixel, a region (domain) corresponding to the bright state and a region (domain) corresponding to the dark state can be mixed in the pixel. A gradation display is enabled by the area ratio of these domains. This method can be used even when the light amount is modulated stepwise (for example, 16 gradations), but a continuous light amount change is required for analog gradation display.

Next, two scanning signal lines are simultaneously selected. This operation will be described with reference to FIG.
Here, FIG. 15A shows transmittance-applied voltage characteristics when pixels on two scanning signal lines are grouped together. In FIG. 15A, scanning is performed for transmittances of 0% to 100%. (Signal) A display area of the pixel B on the line 2 and a transmittance of 100
% To 200% is shown as the display area of the pixel A on the scanning (signal) line 1. That is, since one pixel is configured for one scanning line, when two pixels are simultaneously scanned, the transmittance when both the pixel A and the pixel B are all in the light transmitting state is set to 200%.

Here, two scanning lines are simultaneously selected for one piece of gradation information. However, an area having an area of one pixel is allocated to display one piece of gradation information. ing. This will be described with reference to FIG.

At the temperature T ₁ , the inputted gradation information is written in a range corresponding to 0% at the applied voltage V ₀ and 100% at V ₁₀₀ . Here, as is apparent from FIG.
_{In 1} , the entire range (pixel area) is on the scanning line 2 (see the hatched portion in the figure). However, when the temperature changes from T ₁ to T ₂
, The threshold voltage of the liquid crystal drops, so that when the same voltage is applied to the pixel, a wider area in the pixel than at the temperature T ₁ is inverted.

Therefore, in order to correct this, the temperature T ₂
Set across pixel Ryojo the scanning line 1 and the scanning line 2 when the (hatched portion shows the case of a drawing temperature T _2). Further, when the temperature reaches T ₃ rises further, the applied voltage V ₀
The pixel area to be drawn is changed from ~V _100, set only on the scanning line 1 (a hatched portion shows the case of drawing temperature T _3).

As described above, by setting the pixel area for gradation display according to temperature so as to be shifted on two scanning lines, correct gradation display can be maintained in the temperature range of T _{1 to} T _3. Become.

Next, it is assumed that the scanning signals applied to the two scanning lines selected at the same time are different from each other. This is because, as described above, in order to compensate for a change in the threshold value of the liquid crystal inversion due to a temperature change by simultaneously selecting two scanning lines, the scanning signal applied to the two selected scanning signals is changed. This is because they must be different from each other.

This will be described with reference to FIG. The scanning signals applied to the scanning lines 1 and 2 are set such that the threshold value of the pixel A on the scanning line 2 changes continuously. In the figure, the transmittance at a temperature T ₁ - voltage curve, until 100% transmittance indicates that appear in the region on the scanning line 2, until then 200% is in the region on the scanning line 1 Indicates that it will be displayed.

By setting the transmittance-voltage curve from pixel B to pixel A continuously and at the same gradient, pixel A on scanning line 1 and pixel A on scanning line 2 as shown in FIG. Even if the cell shape of the pixel B (see FIG. 16B) is set to be equal, substantially the same as the cell shown in FIG. 14B when the pixels A and B have continuous threshold characteristics. Display becomes possible.

[0030]

However, in such a conventional liquid crystal element, when gradation display is performed using FLC, a problem is a propagation delay of an electric signal in the liquid crystal element. That is, the propagation delay of the voltage waveform in the liquid crystal element (including the resistance component of the input IC to lkΩ / line) is caused by the capacitance of the liquid crystal layer, the amount of current caused by reversal of spontaneous polarization,
It is determined by the wiring resistance of the electrodes, the internal resistance of the IC, and the like.

The spontaneous polarization of FLC is 6 nc / cm ²
In this case, the influence of the rising edge of the pulse is negligible, so that the rounding of the voltage waveform (delay of the rising edge of the applied voltage pulse) is determined by the capacitance of the liquid crystal and the wiring resistance, and the display is 280 × 220 mm. In a display having an area, one signal line has a capacity of about 1314 pF, a wiring resistance of about 4.1 kΩ, and an internal resistance of the IC of about 1 kΩ, so that the wiring resistance is about 5.1 kΩ (common side), and the waveform is The rounding is about 15.4 μs at the rise from 0% to 90%. In the same cell, the segment side (information signal input side) has a wiring resistance of 6.4 kΩ and an IC internal resistance of 1.0 kΩ, and the rounding is about 22.0 μs from 0% to 90%. That is, the rounding inside the element is distributed from about 2.7 μs to about 22.0 μs.

On the other hand, as shown in FIG. 13, in the method of changing the thickness of the liquid crystal layer (cell thickness), when the electric field intensity is changed and gradation display is performed, the rounding and the transmittance are as follows. Relationship.

[0033]

[Table 1] Therefore, a difference (variation) in transmittance of 18% or more occurs inside the liquid crystal element, so that the display quality is significantly reduced.

In order to solve the above-mentioned problem, the present applicant has formed a metal wiring on a glass substrate and dropped a UV curable resin between adjacent metals as disclosed in, for example, Japanese Patent Application Laid-Open No. 6-347810. And press the mold from above to
A manufacturing method was proposed in which a V resin was cured and an ITO film was formed thereon to contact a metal wiring to form a wiring substrate.

However, this method can solve the delay of the voltage waveform, but has the following problems.

That is, in order to form a saw-like shape in the pixel, the metal surface must be precisely machined with a diamond tool or the like, and the metal mold becomes very expensive.
This significantly increases the cost of the wiring board. Further, precise alignment molding is required so that a saw-shaped mold corresponds to one pixel of the wiring board, and the yield is low. Furthermore, in order to realize precise alignment molding, a dedicated alignment molding is required, which is very difficult to manufacture, and the price of the device becomes very expensive. Is significantly increased.

Accordingly, the present invention has been made to solve such a conventional problem, and is intended to provide a liquid crystal device and a liquid crystal device capable of easily forming a gradient in one pixel at low cost. It is intended to provide a manufacturing method.

[0038]

According to the present invention, a plurality of auxiliary electrodes formed on a surface of a light-transmitting substrate, and an insulating layer formed by exposing a polymer material embedded between the auxiliary electrodes are formed. And a liquid crystal element in which a liquid crystal is sandwiched by a wiring board having the auxiliary electrode and a main electrode formed on the surface of an insulating layer, and an intersection of the main electrode of each of the wiring boards is a pixel. Is characterized in that the polymer material has a thickness distribution within a pixel by exposure to the polymer material using a photomask having a light-shielding rate gradient.

The present invention is also characterized in that the transmittance gradient of the photomask changes continuously.

Further, the present invention is characterized in that the transmittance gradient of the photomask changes stepwise.

Further, the present invention is characterized in that a color filter layer is provided between the translucent substrate and the insulating layer.

Further, the present invention is characterized in that a photosensitive resin is used as the polymer material.

Further, the present invention is characterized in that a ferroelectric liquid crystal is used as the liquid crystal.

Further, the present invention provides a method for manufacturing a semiconductor device, comprising: a plurality of auxiliary electrodes formed on a surface of a light-transmitting substrate; an insulating layer formed by exposing a polymer material embedded between the auxiliary electrodes; In a method for manufacturing a liquid crystal element in which a liquid crystal is sandwiched by a wiring board having a main electrode formed on a surface of an insulating layer and a pixel at an intersection of the main electrode of each of the wiring boards, the insulating film is formed. In this case, the insulating film has a thickness distribution in the pixel by exposing the polymer material using a photomask having a light-shielding rate gradient.

Further, as in the present invention, by exposing a polymer material embedded between a plurality of auxiliary electrodes formed on the surface of a light-transmitting substrate using a photomask having a light-shielding rate gradient, low An insulating layer having a thickness distribution in a pixel can be formed easily at low cost.

[0046]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the structure of the liquid crystal device according to the first embodiment of the present invention.
Is a liquid crystal element, 2a and 2b are first and second wiring boards, 3 is a liquid crystal, 4 and 5 are transparent electrodes which are main electrodes formed of ITO, 6 is a metal electrode which is an auxiliary electrode, and 7 is an alignment film. It is.

Here, as shown in FIG. 2, the first wiring substrate 2a under the liquid crystal element 1 has a photosensitive resin (ultraviolet curable) which is a polymer material on the surface of a glass substrate 8 which is a translucent substrate. A transparent electrode 4 on the surface of the insulating layer 9 and a scanning electrode 4 having the same thickness in FIG. I am trying to do it. By forming the transparent electrode 4 at the same thickness on the surface of the insulating layer 9 formed in a sawtooth shape in this manner, the distribution of the interval between the upper and lower electrodes 4 and 5 within one pixel can be improved.
That is, the thickness distribution is provided.

The glass substrate 8 used in the present embodiment is
Has a thickness of about 1 mm, which is often used for liquid crystal substrates, and is made of a general material such as soda glass (blue plate glass). The ultraviolet-curable resin for forming the insulating layer 9 is gelatin, casein, glue, polyvinyl alcohol, polyimide, polyimide amide, polyester amide, polyester imide, polyamide, polyester, polyparaxylylene, polycarbonate,
Polyvinyl acetal, polyvinyl acetate, polystyrene, cellulose jusi resin, melamine resin, urea resin, acrylic resin, epoxy resin, polyurethane resin,
It can be arbitrarily set from a resin obtained by imparting photosensitivity to a polysilicon resin and a general photoresist resin.

Next, a method of manufacturing the first wiring board 2a will be described.

First, as shown in FIG. 3A, a metal electrode 6 having a thickness of 2 μm is formed on a glass substrate 8 by using Al, Mo, or the like, and thereafter, as shown in FIG. The photosensitive polyamide resin "PA-1000" (manufactured by Ube Industries, Ltd.) is uniformly applied with a spinner or the like to a thickness of 2 [mu] m and prebaked. Next, as shown in (c), the photosensitive resin 9 'is exposed by irradiating ultraviolet (UV) light 11 through a photomask 10.

The photomask 10 has a density gradient in which the light-shielding ratio is continuously changed in a plane corresponding to the pixel, and is exposed to the ultraviolet light 11 through the photomask 10. By irradiating the conductive resin 9 ′, light 11 having an intensity corresponding to the concentration gradient of the photomask 10 is obtained.
Is irradiated on the photosensitive resin 9 ′, so that the photosensitive resin 9 ′ is cured.

Here, the degree of curing of the photosensitive resin 9 ′ varies depending on the intensity of the light 11 to be irradiated, and thus the intensity corresponding to the concentration gradient of the photomask 10 is thus determined. When the light 11 is irradiated and the developing process is performed to remove the uncured photosensitive resin 9 ′, the photosensitive resin 9 ′ remains on the glass substrate 8 in a shape corresponding to the concentration gradient.

Various methods are conceivable for giving the photomask 10 a concentration gradient as described above. For example, a substrate obtained by applying a silver salt emulsion to a glass substrate (hereinafter referred to as a mask substrate) is used. By masking portions of the mask substrate other than the pixels to be exposed, and gradually shifting the area of light to be irradiated, the amount of light irradiation on the mask substrate is continuously changed. Next, by developing this mask substrate, silver is deposited in accordance with the amount of light irradiation, and a photomask having a concentration gradient in a pixel can be manufactured. Further, by transmitting light areas at regular intervals when irradiating light, a photomask having a different density for each area in a pixel can be manufactured.

On the other hand, after irradiating the photosensitive resin 9 ′ with the ultraviolet (UV) light 11 through the photomask 10 and exposing the photosensitive resin 9 ′, the photosensitive resin 9 ′ is developed with a special developing solution. The sawtooth-shaped insulating layer 9 shown in FIG.

Next, on the insulating layer 9 having such a shape, I
The scanning electrode 4 is formed by sputtering and patterning the TO film as shown in FIG. Finally, an alignment film L manufactured by Hitachi Chemical Co., Ltd. is formed on the scanning electrode 4 as an alignment film 7.
Q-1802 is formed at about 300 ° to form the first wiring board 2a as shown in FIG.

When manufacturing the liquid crystal element 1 using such a first wiring board 2a, first, a cell is formed by the first wiring board 2a and the second wiring board 2b on the opposite side. It can be manufactured by filling the cell with the rear liquid crystal 3 (see FIG. 1). Here, the second wiring board 2b is formed by forming the same alignment film 7 on the stripe-shaped information electrodes 5, and does not have the uneven shape unlike the first wiring board 2a.

On the other hand, when manufacturing the liquid crystal element 1, the first
The rubbing direction of the second wiring boards 2a and 2b is parallel to the rubbing direction, and the rubbing direction of the second wiring board 2b is the first rubbing direction.
The cell was formed by shifting the rubbing direction of the wiring board 2a by about 6 ° in the right-hand screw direction. In addition, control of cell thickness
The thin portion was about 1.10 μm, and the thick portion was 1.64 μm. Further, the scanning electrodes 4 of the first wiring substrate 2a were patterned along the ridges in a stripe shape so that one side of the saw shape became one pixel. Further, the width of the scanning electrode 4 is set to 300 μm, and the pixel size is set to 300 μm.
It was set to a rectangle of X200 μm.

The following table shows the liquid crystal materials used.

[0060]

[Table 2] By the way, in Al and Mo forming the metal electrodes 4 and 5, Al has a ρ of about 3.5 × 10 ⁻⁶ Ωcm, and Mo has a ρ of about 2 × 10 ⁻⁶ Ωcm. When the metal electrodes 4 and 5 are formed, the rounding amount (0
量 90%) was improved to about 2 μs.

As described above, by exposing the photosensitive resin 9 'using the photomask 10 in which the concentration gradient is formed, the insulating layer 9 having a thickness distribution within one pixel can be easily formed. it can. Also, such a photomask 1
By using 0, the cost in the case of manufacturing the wiring board 2a can be reduced to about 1/2 compared with the conventional case, and the cost can be reduced.

Next, a second embodiment of the present invention will be described.

In the present embodiment, the transparent electrode is formed in a step shape. FIG. 4 shows a method of manufacturing a wiring board having such a step-shaped transparent electrode. 3 schematically shows the steps after the exposure. 4, the same reference numerals as those in FIG. 3 indicate the same or corresponding parts.

First, the photosensitive resin 9 ′ applied on the glass substrate 8 is irradiated with ultraviolet (UV) light 11 through a photomask 10 A as shown in FIG. . Here, the photomask 10A has a density gradient by changing the light blocking ratio in steps of 50 μm width in the pixel. After that, when the photosensitive resin 9 ′ is developed with a dedicated developer, a step-like insulating layer 9 as shown in FIG. 3B is formed on the glass substrate 8.

Next, an I layer is formed on the insulating layer 9 having such a shape.
The TO film is formed by sputtering and patterned to form the scanning electrode 4A as shown in FIG. Finally, an alignment film LQ-1802 manufactured by Hitachi Chemical Co., Ltd. was formed on the scan electrode 4A as the alignment film 7 by about 300 ° to form the first wiring substrate 2a as shown in FIG.

Next, a third embodiment of the present invention will be described.

In this embodiment, a pigment-based color filter layer composed of red (R), green (G), and blue (B) pixels is formed between the metal electrodes 6. A method of manufacturing a wiring board having such a color filter layer will be described with reference to FIG. In the figure, the same reference numerals as those in FIG. 3 indicate the same or corresponding parts.

In this embodiment, as in the first embodiment, first, after forming the metal electrode 6 on the glass substrate 8,
A pigment-based color filter 12 composed of red (R), green (G), and blue (B) pixels is provided between the metal electrodes 6 on the glass substrate 8 as shown in FIG. It was formed to a film thickness of about 1 μm by the method. In addition, the color filter 12 may be formed by a method other than the photolithography etching method.
For example, it can be formed by a printing method, a sublimation transfer method, or an inkjet method.

Next, the photosensitive resin 9 is exposed on the color filter 12 through a photomask (not shown) having a concentration gradient by irradiating it with UV light and developed, as shown in FIG. The insulating layer 9 having a simple sawtooth shape is formed.

Next, the insulating layer 9 thus formed is formed.
A scanning electrode 4 is formed by forming and patterning an ITO film on the substrate, as shown in FIG. Finally, an alignment film LQ-1802 manufactured by Hitachi Chemical Co., Ltd. is formed on the scanning electrode 4 as the alignment film 7 at a thickness of about 300 °.
A first wiring board 2a having a color filter as shown in (d) was formed.

FIG. 6 is a block diagram of a liquid crystal device provided with a display element according to the present embodiment, and an image display operation of the liquid crystal device will be described with reference to FIG.

In the figure, reference numeral 101 denotes a liquid crystal device;
Is a graphic controller. The graphic controller 102 scans the liquid crystal device 101 with scanning line address information specifying scanning electrodes (see FIG. 1) and image information (PD0 to PD3) on the scanning lines specified by the address information. Line drive circuit 104 and information line drive circuit 105
Is transferred to the display drive circuit 120 composed of

In this embodiment, since the image information having the scanning line address information and the display information is transferred through the same transmission line, the two types of information must be distinguished. The signal for this identification is AH / DL, and when the AH / DL signal is at the H level as shown in FIG. 7, this indicates display information.

The scanning line address information is supplied to the drive control circuit 111 in the liquid crystal device 101 by the image information PD0 to PD0.
After being extracted from the image information transferred as PD3, it is output to the scanning line driving circuit 104 in accordance with the timing of driving the designated scanning line. The scanning line address information is input to a decoder 106 in the scanning line driving circuit 104, and is supplied to the display panel 103 via the decoder 106.
Are driven by the scanning signal generation circuit 107.

On the other hand, the display information is guided to the shift register 108 in the information line driving circuit 105,
It is shifted on a pixel-by-pixel basis. When the shift register 108 completes the shift for one scanning line in the horizontal direction, the display information for 1280 pixels is transferred to the line memory 109 provided therewith, and is output from the information signal generating circuit 110 as each information signal. You.

In this embodiment, the driving of the display panel 103 in the liquid crystal device 101 and the generation of the scanning line address information and the display information in the graphics controller 102 are performed asynchronously. 102 and display panel 103
It is necessary to synchronize with the drive of. This synchronization signal is a SYNC signal, and the liquid crystal device 1 is controlled every one horizontal scanning period.
01 is derived by the drive control circuit 111 in FIG.

Then, the graphics controller 10
The second side always monitors this SYNC signal,
If the signal is at L level, image information is transferred, and conversely, H
At the level, the transfer is not performed after the transfer of the image information for one horizontal scanning line is completed. That is, in FIG. 6, when the graphics controller 102 detects that the SYNC signal has become L level, the AH / D
The L signal is set to the H level to start transferring image information for one horizontal scanning line.

On the other hand, the drive control circuit 1 in the liquid crystal device 101
Numeral 11 sets the SYNC signal to the H level during the image information transfer period. After a predetermined horizontal scanning period, the display panel 103
After the writing to the memory is completed, the drive control circuit 111
The NC signal is returned to the L level again, and image information of the next scanning line can be received.

[0079]

As described above, by exposing the polymer material embedded between the auxiliary electrodes using a photomask having a transmittance gradient as in the present invention, the pixel can be formed easily at low cost. It is possible to form an insulating layer having a thickness distribution in the wiring and a wiring board provided with the insulating layer. By using such a wiring board, propagation delay of a voltage waveform can be reduced, and a liquid crystal element having excellent display characteristics can be manufactured without adding complicated steps.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a liquid crystal element according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a structure of a first wiring substrate of the liquid crystal element.

FIG. 3 is a diagram illustrating a method for manufacturing the first wiring board.

FIG. 4 is a diagram illustrating a method for manufacturing a first wiring substrate of a liquid crystal element according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a method for manufacturing a first wiring substrate of a liquid crystal element according to a third embodiment of the present invention.

FIG. 6 is a block diagram of a liquid crystal device to which the above liquid crystal element is applied.

FIG. 7 is a communication timing chart of image information of the liquid crystal device.

FIG. 8 is a diagram schematically showing a relationship between voltage and transmittance in a conventional area modulation method.

FIG. 9 is a diagram showing a voltage and a light transmission state of a pixel in the conventional area modulation method.

FIG. 10 is a diagram showing a change in voltage-transmittance shown in FIG. 9 with temperature.

FIG. 11 is an explanatory diagram of a driving method using a conventional four-pulse method.

FIG. 12 is a diagram showing a driving waveform of the conventional four-pulse method.

FIG. 13 is a cross-sectional view of a conventional liquid crystal cell having a cell thickness gradient.

FIG. 14 is a first explanatory diagram of a conventional pixel shift method.

FIG. 15 is a second explanatory view of the conventional pixel shift method.

FIG. 16 is a third explanatory view of the conventional pixel shift method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal element 2a, 2b Wiring board 3 Liquid crystal 4,5 Transparent electrode 6 Auxiliary electrode 7 Alignment film 8 Glass substrate 9 Insulating layer 9 'Photosensitive resin 10, 10A Photomask 11 Ultraviolet light 12 Color filter

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Matsuo 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (7)

[Claims] 1. A plurality of auxiliary electrodes formed on a surface of a light-transmitting substrate, an insulating layer formed by exposing a polymer material embedded between the auxiliary electrodes, and the auxiliary electrode and the insulating layer The liquid crystal is sandwiched by a wiring substrate having a main electrode formed on the surface of the substrate, and a liquid crystal element having a pixel at an intersection of the main electrode of the wiring substrate. A liquid crystal element having a thickness distribution in a pixel by exposure to the polymer material using a mask. 2. The photomask according to claim 1, wherein the transmittance gradient of the photomask changes continuously.
The liquid crystal element according to the above. 3. The photomask according to claim 1, wherein the transmittance gradient of the photomask changes stepwise.
The liquid crystal element according to the above. 4. The liquid crystal device according to claim 1, wherein a color filter layer is provided between the translucent substrate and the insulating layer. 5. The liquid crystal device according to claim 1, wherein a photosensitive resin is used as the polymer material. 6. The liquid crystal device according to claim 1, wherein a ferroelectric liquid crystal is used as the liquid crystal. 7. A plurality of auxiliary electrodes formed on a surface of a light-transmitting substrate, an insulating layer formed by exposing a polymer material embedded between the auxiliary electrodes, and the auxiliary electrode and the insulating layer. In a method of manufacturing a liquid crystal element in which a liquid crystal is sandwiched by a wiring board having a main electrode formed on the surface of the liquid crystal element and an intersection of the main electrode of each of the wiring boards is a pixel, when the insulating film is formed, A method for manufacturing a liquid crystal element, wherein the insulating film has a thickness distribution in a pixel by exposing the polymer material using a photomask having a light-shielding rate gradient.