JP2617709B2 - Optical modulation element and driving method thereof - Google Patents

Description

The present invention relates to an optical modulation element such as a liquid crystal or electroluminescence, a modulation element that performs various types of modulation using the action of an electric field, and a method of driving these modulation elements. It is about.

[Prior Art] FIG. 10 schematically shows a general electrode configuration in a conventional optical modulation element. Specifically, for example, a TN (twisted nematic) liquid crystal, a ferroelectric liquid crystal, or the like is used. 2 shows the configuration of the liquid crystal display element. As shown in FIG. 10, the scanning electrode group 101 and the information electrode group 102 are connected to a driver 105 via a signal supply line 106, and each of the electrodes corresponds to a signal from the scanning electrode drive unit 103 and the information electrode drive unit 104. , The electric field applied to the liquid crystal sandwiched between the electrodes is controlled.

[Problems to be Solved by the Invention] However, in the scanning electrode group 101 and the information electrode group 102, each electrode has an independent structure, and the signal supply line 106 is connected to one end thereof. Therefore, for example, when the electrode is a striped thin film deposited on a glass substrate, there is a problem that the potential becomes unstable on the side away from the signal supply line 106 due to a breakage in the middle of the stripe or the like. . Further, in order to apply a desired potential to each of the electrode groups, it is necessary to provide a number of drivers corresponding to each potential. In particular, when the number of pixels (electrode intersections) and the potential to be selected are increased, There were problems such as an increase in the cost of the drive unit.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and provides an optical modulation element capable of making the potential on each electrode surface substantially uniform and greatly reducing the number of drivers, and a method of driving the same. With the goal.

[Means for Solving the Problems] A first aspect of the present invention created to solve the above problems is to provide a pair of conductors at both longitudinal ends of a plurality of striped conductive films. A first substrate having a first electrode group, a second substrate having a second electrode intersecting the longitudinal direction, and an optical modulation substance arranged between the first and second substrates, A first power source for applying a potential selected from a plurality of reference potentials to the pair of conductors independently and applying a predetermined potential to the conductive film by a combination of the potentials applied to the pair of conductors; And a second power source for applying a predetermined potential to the second electrode, wherein a width direction of the conductive film is provided between the conductive film and the pair of conductors. The resistance is sufficiently higher than the resistance of the conductive film so that a substantially uniform potential is applied to the conductive film. In optical modulation element characterized in that by interposing a resistor with.

Further, a second aspect of the present invention is a first substrate having a first electrode group in which a pair of conductors are provided at both ends in a longitudinal direction of a plurality of stripe-shaped conductive films, A driving method of an optical modulation element, comprising: a second substrate having a second electrode to be formed; and an optical modulation substance disposed between the first and second substrates. A resistor having a resistance sufficiently higher than that of the conductive film is interposed between the conductive film and the pair of conductors, and the pair of conductors are independently provided with a plurality of reference potentials. A potential that is selected is applied, and by the combination of the potentials that are applied to the pair of conductors, a substantially uniform potential is applied in the width direction of the conductive film and a predetermined potential is applied to the second electrode. By changing the state of the optical modulation substance In the driving method of adjusting element.

[Operation] Since a pair of conductors is disposed at both ends in the longitudinal direction of the conductive film via a high-resistance resistor, when an independent voltage is applied to each conductor, A large voltage drop occurs in the high resistance resistor, and a substantially uniform potential is applied in the width direction of the conductive film. Further, a potential corresponding to a combination of potentials applied to the pair of conductors is applied to the conductive film between the conductors.

Embodiment FIG. 1 is a longitudinal sectional view showing an embodiment of an electrode configuration of an optical modulation element according to the present invention, and FIG. 2 is a plan view of the electrode.

In the electrode configuration shown in FIG. 1, the conductive film (the first electrode 1 formed of a resistance film having a relatively low resistance is provided on the base 5a,
Further, a plurality of electric conductors 3 and 4 are provided thereon via a relatively high-resistance resistor 2. On the other hand, on the side facing the base 5a, a second stripe-shaped second as shown in FIG.
An electrode (counter electrode) 11 is provided on the base 5b, and the modulating substance 10 is sandwiched between the bases.

The first electrode 1 and the second electrode 11 are made of glass or other base material 5a, 5b.
It is formed on a transparent thin film of ITO, SnO ₂ , In ₂ O ₃ or the like or a metal thin film of Au or the like.

The resistor 2 is a resistor having a resistance sufficiently higher than that of the first electrode 1 and is formed of polyester or the like in which a small amount of metal-doped conductive fine powder such as Si, Se or carbon is kneaded. .

The conductors 3 and 4 are made of Al, Au or the like, and are formed on the resistor 2.

Next, a method of applying a desired potential to the first electrode in the above-described electrode configuration will be described with reference to FIGS.

In FIG. 3, the conductor 3 is connected to a first power supply 6a, and the conductor 4 is connected to a second power supply 6b.
And Vb. Here, for simplicity of explanation, two power 6a and 6b voltage Va and Vb is assumed to be both three levels of V _1, V _2, V _3.

The potential between the conductors 3 and 4 is, as shown in FIG.
Although it changes between the resistor regions 2a and 2b and the first electrode region 1a,
It is determined by the combination of applied voltages Va and Vb. That is, when both the combination of Va and Vb is V ₁ , V ₁ , V ₁
V intermediate value when the V _12, V ₁ and V ₃ of the substantially intermediate value when V _2
13 (V _2), V ₂₃ approximately intermediate values when V _2, V ₂ and V ₃ when both of V _2, both as that V ₃ when the V _3, the potential of the first electrode 1 is five different It is determined.

Hereinafter, when this potential is between the conductors 3 and 4, the first electrode 1
The condition for giving a substantially constant value over the entire area will be described.

FIG. 5 is an equivalent circuit of the electrode configuration shown in FIG. Here, one of the necessary conditions is that the resistance r ₂ of the resistor _{2 is}
There By sufficiently larger than the resistance r ₁ of the first electrode 1, by a configuration such, cause a large voltage drop due to the resistor 2, to reduce the voltage drop across the first electrode 1,
An almost constant potential can be obtained.

The relationship between the resistance values will be described more specifically. For example, as shown in a plan view in FIG.
When the width of the electrode 1 is a and the sheet resistance value is about 100 Ω / sq, the resistance value of the resistor 2 sandwiched between the first electrode 1 and the conductor 3 or 4 is 10 ⁴ Ω over the length a. It is desirable to obtain the above. Further, Joule heat due to current is generated in the resistor ₂ , and in order to minimize this, it is preferable that the resistor r2 is appropriately increased. Therefore, as the resistor 2, a semiconductor having a high withstand voltage or a resistor having a higher resistance than the semiconductor is suitable.

The next necessary condition is that the conductor 3 or 4 should have a sufficiently low electric resistance.
For this purpose, it is desirable to use a metal having a particularly low resistance and having a sheet resistance value of several tens Ω / sq or less.

By satisfying the above conditions, a stable and constant potential can be applied to the first electrode 1. In particular, even at a position distant from the signal supply end of the thin-film striped first electrode 1, Since a stable potential is applied to the conductor 3 or 4, the potential does not become unstable even if a part of the first electrode 1 is broken.

Further, in the configuration shown in FIG.
Various types of modulation are performed by an electric field formed between the electrodes (1, 2, 3, and 4) and the second electrode 11 configured according to the present invention. Is smaller than the interelectrode resistance of the modulating substance 10,
A sufficient partial pressure to the modulation substance 10 can be obtained. Also,
It is desirable to perform various kinds of smooth modulation by selecting a resistor such that the product of the modulating substance 10 with the interelectrode capacitance, that is, the time constant is shorter than the desired modulation response period.

The optical modulator used in the present invention includes a first optically stable state (for example, forming a bright state) and a second optically stable state (for example, forming a dark state) in response to an applied electric field. That is, a substance having at least two stable states with respect to an electric field, particularly a liquid crystal having such properties is preferable.

As the bistable liquid crystal preferably used in the driving method of the present invention, a chiral smectic liquid crystal having ferroelectricity is most preferable. Among them, chiral smectic C phase (SmC ^* ), H phase (SmH ^* ), and I phase ( SmI ^* ),
F-phase (SmF ^* ) and G-phase (SmG ^* ) liquid crystals are suitable. For this ferroelectric liquid crystal, please refer to “Le Journal de
Physique Lettle "(" LE JOURNAL DE PHYSIQUELE
TTERS ") Volume 36 (L-69) 1975" Ferroelectric Liquid Crystals "(" Ferroelectric Li
quid Crystals ”);“ Applied Physics
Letters "(" Applied physics Letters ") Volume 36, Vol.
No. 11, 1980 "Submicro Second Bistable Electro-Optic Switching In Liquid Crystals"("Submicro Second Bistable
Electrooptic Switching in Liquid Crystals ");
“Solid state physics” 16 (141) 1981 “Liquid crystal” and the like, and the ferroelectric liquid crystal disclosed therein can be used in the present invention.

More specifically, examples of the ferroelectric liquid crystal compound used in the method of the present invention include decyloxybenzylidene-p'-
Amino-2-methylbutylcinnamate (DOBAMBC),
Hexyloxybenzylidene-p'-amino-2-chloropropylcinnamate (HOBACPC) and 4-o-
(2-methyl) -butyl resorcylidene-4'-octylaniline (MBRA 8) and the like can be mentioned.

When a device is constructed using these materials, a heater is embedded in the device as necessary in order to keep the liquid crystal compound in a temperature state where it becomes SmC ^* , SmH ^* , SmI ^* , SmF ^* , SmG ^*. It can be supported by a copper block or the like.

FIG. 11 schematically illustrates an example of a ferroelectric liquid crystal cell. 21a and 21b are substrates (glass plates) coated with transparent electrodes such as In ₂ O ₃ , SnO ₂ and ITO (indium-tin-oxide), between which the liquid crystal molecular layer 22 is perpendicular to the glass surface The liquid crystal of the SmC ^* phase, which is oriented likewise, is sealed. A thick line 23 represents a liquid crystal molecule,
The liquid crystal molecules 23 have a dipole moment ( _P⊥ ) 24 in a direction perpendicular to the molecules. When a voltage higher than a certain threshold is applied between the electrodes on the substrates 21a and 21b, the liquid crystal molecules 23
The orientation of the liquid crystal molecules 23 can be changed so that the helical structure is unwound and all the dipole moments (P _⊥ ) 24 are oriented in the electric field direction. The liquid crystal molecules 23 have an elongated shape, and exhibit refractive index anisotropy in the major axis direction and the minor axis direction thereof. For example, it is easily understood that a liquid crystal optical modulation element whose optical characteristics change depending on the voltage application polarity is obtained. Further, when the thickness of the liquid crystal cell is sufficiently reduced (for example, 1 μm), the helical structure of the liquid crystal molecules is unwound (non-helical structure) even when no electric field is applied as shown in FIG. Child moment P or P '
Takes either the upward (34a) or downward (34b) state. When an electric field E or E 'having a polarity equal to or more than a certain threshold value is applied to such a cell as shown in FIG. 12, an upward direction 34a or a downward direction 34b corresponds to the dipole moment electric field E or E'. In response, the liquid crystal molecules are aligned in one of the first stable state 33a (bright state) and the second stable state 33b (dark state).

There are two advantages of using such a ferroelectric liquid crystal as the optical modulation element. Firstly, the response speed is extremely fast, and secondly, the alignment of liquid crystal molecules has a bistable state. Explaining the second point with reference to FIG. 12, for example, when an electric field E is applied, the liquid crystal molecules are aligned in the first stable state 33a. This state is the first stable state even when the electric field is cut off.
33a is maintained, and when an electric field E 'in the opposite direction is applied,
The liquid crystal molecules are oriented to the second stable state 33b and change the direction of the molecules.
Each stable state has a memory function. In order to effectively realize such a high response speed and bistability, it is preferable that the cell is as thin as possible, and generally 0.5 μ to 20 μ, particularly 1 μ to 5 μ is suitable.

A liquid crystal-electro-optical device having a matrix electrode structure using a ferroelectric liquid crystal of this type has been proposed by Clarke and Lagabal in US Pat. No. 4,367,924.

Next, a method of driving an optical modulator using the ferroelectric liquid crystal as the modulator substance 10 in FIG. 1 will be described.

FIG. 7A schematically shows the wiring of the electrodes, and FIG. 7B is an explanatory diagram of the potentials in the resistor regions 2a and 2b. Here, when the inversion threshold voltage of the strong induction liquid crystal is V _th , the voltage V ₀ applied to the first electrode is
Is determined so that | ± V ₀ | <| ± V _th | <1 ± 2V ₀ |. When such a voltage relationship is set, the ferroelectric liquid crystal molecules sandwiched between the first electrode 1 and the second electrode 11 do not invert when the absolute value of the voltage between both electrodes is V ₀ or less, In the case of 2V ₀ or more, it is inverted according to the direction of the applied voltage. In the following description, when the potential difference between the two electrodes is + 2V ₀ or more, the pixel is inverted to “white”.
When −2V ₀ or less, it should be inverted to “black”.

In FIG. 7, + V is applied to the first electrode 1 as the selection potential V _{SS.
When 0} is given and −V ₀ is applied to the second electrode 11 as the selection potential V _IS , the potential difference between the two electrodes becomes −2V ₀ and the pixel is inverted to “black”. At this time, the potential of the second electrode 11 is changed to the non-selection potential V _INS
When = 0, the potential difference becomes −V ₀ and does not exceed V _th , so that the pixel is not inverted and is maintained as it is.

On the other hand, if the potential of the first electrode 1 is the non-selected electrode V _SNS1 = 0 and the potential of the second electrode 11 is V _IS = −V ₀ , the potential difference is −V.
_When the potential of the second electrode 11 is set to V _INS = 0, the potential difference becomes 0, and neither pixel is inverted.

When the potential of the first electrode 1 is set to the non-selection electrode V _SNS2 = −V ₀ and the potential of the second electrode 11 is set to V _IS = −V ₀ , the potential difference becomes zero.
Further, when the potential of the second electrode 11 is V _INS = 0, the potential difference becomes + V _0, and therefore the pixel is not inverted in any case.

That is, in the above combination, the first electrode 1 and the second electrode 1
The potential difference between the electrode 11 exceeds the threshold value _Vth , and the pixel becomes “black”
Only when the potential of the first electrode is V _SS = + V ₀ and the potential of the second electrode 11 is V _IS = −V ₀ .

On the other hand, application of potential to the first electrode 1 is obtained by applying a potential of each of the conductors 3, 4 + V ₀ or -V _0, but to give a potential of + V ₀ to V _SS, the conductor When potential + V ₀ is applied to both 3 and 4, when the combination of 3 and 4 is + V ₀ and −V ₀ , V _SNS1 = 0, and when both are −V ₀ , V _SNS1
SNS2 = V _SCL = -V ₀ .

The pixel of the optical modulation element made of the ferroelectric liquid crystal is "white".
For example, if the first electrode 1 is set to V _SCL = −V ₀ and the second electrode 11 is set to V _ICL = + V ₀ , the potential difference becomes + 2V ₀ ,
It is possible to apply a voltage larger than V _th to the liquid crystal with the opposite polarity to the case of inverting to "black", and the pixel is inverted to "white".

Hereinafter, the driving method of the optical modulation element having a large number of pixels will be described in more detail with reference to FIGS.

FIG. 8 is a plan view showing a circuit configuration of an optical modulation element having a large number of pixels. In FIG. 8, 1001,1002,100
, ... correspond to the first electrode 1, and 11001, 11002, 11003, ... serve as information electrodes, and the second electrodes
It corresponds to the electrode 11 (counter electrode). Scan electrode 10
01, 1002, 1003, ... are provided with conductors 2a001, 2a002, 2a003, ... Corresponding to the conductor 3 and conductors (2b001, 2b002, 2b003, ...) Corresponding to the conductor 4 in FIG. Although not shown, between each of the conductors and the scanning electrode,
The resistor is formed.

Further, reference numeral 100 is a drive unit for information electrodes, which is connected to the information electrodes 11001, 11002, 11003, .... 200
Reference numerals a and 200b denote scan electrode drive units, respectively. 200a has drivers 2a1 to 2a4, and conductors 2a001 and 2a00
2, ... are connected in the order of 2a1, 2a2, ..
005) and thereafter, in the same manner, the connection is made in the order of 2a1, 2a2,. On the other hand, 200b has drivers 2b1 to 2b4, and conductors 2b001, 2b002, ...
1,2b2, ... connected.

In the above electrode configuration, first, the drive unit 200b
The driver 2b1 at the potential + V ₀ , and the other driver 2b2
~ 2b4 is set to the potential -V ₀ . In the drive unit 200a is to the driver 2a1 potential + V _0, of the other driver 2
the to potential -V ₀ a2~2a4. In this case, the conductor 2b0
Potentials + V ₀ for 01 to 2b004, −V _{0 for} 2b005 to 2b016, + V ₀ for conductors 2a001, 2a005, 2a009, and 2a013, and −V _{0 for} conductors connected to other drivers 2a2 to 2a4. Is applied.

At this time, the scanning electrode to which the selection potential V _SS = + V ₀ is applied is 100
1 only, and 1002 to 1004,1005,1009,1013 have V _SNS1 = 0
In all other _cases , the potential is V _SNS2 = −V ₀ . That is,
A pair of conductors sandwiching the scanning electrodes 1001, 1002, ...
Only when the combination of 2a001 and 2b001, 2a002 and 2b002,... Is + V ₀ , the selection potential V _SS = is applied to the scan electrodes 1001, 1002,.
+ V ₀ will be applied.

At this time, a signal corresponding to a desired image, that is, a selection potential V _IS = −V ₀ or a non-selection potential V _INS = 0 is applied to each information electrode 11001, 11002,.
Scanning electrodes 1001 by sequentially or simultaneously applying
The pixel writing of the line formed by is performed.

Furthermore, with the potential of re + V ₀ driver 2b1 by the drive unit 200b, the potential of the other drivers 2b2~2b4 and -V _0, + V ₀ the potential of the driver 2a2 by a drive unit 200a simultaneously, the other driver 2A1,2a3, If 2a4 is -V ₀ , only scan electrode 1002 has V _SS = + V ₀ .
Hereinafter similarly, sequentially applied to + V ₀ to the scan electrodes 2a001~2a004 when only the + V ₀ driver 2b1, further driver 2b
When +2 is set to + V ₀ and the other drivers 2b1, 2b3, and 2b4 are set to −V ₀ , the driver 2a1 to 2a4 are sequentially supplied with + V ₀ , so that the lines from the scan electrodes 1005 to 1008 can be selected at the selection potential V _SS = + V Can be ₀ . By repeating such operations in order, the forward selection potential V _SS = + V ₀ can be applied to the scan electrode 1016, and the drive unit 100 synchronizes V to the information electrodes 11001, 11002, ... In synchronization with each line selection.
By giving _IS or V _INS , the state of the pixel can be sequentially determined for each line.

Further, the state of all pixels is erased to a uniform state prior to the writing of the image, but this erasing may be performed collectively on all lines, or prior to writing for each line. Alternatively, only the writing line may be erased.

When erasing the entire surface collectively, the driver 2a
1 to 2a4, 2b1 to 2b4 are all set to the potential of V _SCL = −V ₀ , and 1
This can be done by setting all the information electrodes of 1001, 11002, ... To V _ICL = + V ₀ .

On the other hand, as a specific example of erasing for each line, prior to the writing for each line, a potential obtained by inverting the polarity of the potential applied at the time of each writing is applied to the drivers 2a1 to 2a4 and 2b1 to 2b4, respectively. Applied and then V
_{As ICL} , the potential whose polarity is inverted with that of V _IS is applied to electrodes 11001, 11002,
It suffices to provide a phase for ...

In the above embodiment, the method in which the electrodes 1001, 1002,... Are used as scanning electrodes and the selection potential V _SS is sequentially applied has been described. However, as another driving method, the electrodes 11001, 11002,. It is also possible to drive by simultaneously giving information signals to 2a1, 2a2, ... And time-dividing 2b1, 2b2 ,. To give a specific example, first, the electrode 11001 is set to -V ₀ , the other electrodes 11002, 11003, ...
Is set to 0, and the line on the electrode 11001 is selected. This time,
First, set the driver 2b1 to + V _0, and set the other drivers 2b2,2b3,2b4
Is set to −V ₀ . In synchronization with this, + V ₀ in the case of selection as the information signal to the driver 2A1～2a4, when in the case of non-selection gives simultaneously -V ₀ respectively, the potential of the electrode 1001 to 1004 is + V ₀ or 0 or And the pixel state is determined. At this time, the potentials of the other electrodes 1005, 1006, ... Are 0 or −V ₀ and all are less than V _th , so that image writing is not performed.

Further, the driver 2b2 is set to + V ₀ , and the other drivers 2b1, 2b
3,2b4 is set to −V ₀ . When applying a + V ₀ or -V ₀ in accordance with the information to the driver 2a1~2a4 Similarly, the potential of the electrode from 1005 to 1008 is + V ₀ +0 or the determined state of the pixel is determined. In the same manner, + V ₀ is sequentially applied to the drivers 2b3, 2b4,..., The others are maintained at −V ₀ , and simultaneously + V ₀ or −V ₀ is applied to the drivers 2a1 to 2a4 in synchronism with the application of + V ₀ or −V _0. Is formed. After this, electrode 1
By setting 1002 to −V ₀ and setting the others to 0, writing to the line on the electrode 11002 is performed in the same manner.

In the above driving example, 16 electrode lines can be driven by 8 drivers, and the number of drivers can be greatly reduced. According to the circuit configuration shown in FIG.
When, for example, X drivers are provided in the drive unit 200a to drive n lines, the drive unit 200b has
It is sufficient if there are n / X drivers, and the total number of drivers is X + n / X. If the total number of drivers is made as small as possible, n may be made to be a square value of X. For example, n is
In the case of 1024 lines, 32 + 1024/32 = 64, and it can be driven by 64 drivers.

FIG. 9 shows another embodiment of the present invention. 9th
In the figure, the same reference numerals as those in FIG. 8 indicate the same parts. In FIG. 9, adjacent conductors on the electrodes 1001, 1002,... Are commonly connected. Of the common conductors, 2a101, 2a201, 2a301, ... Are connected in the order of the drivers 2a1, 2a2, ..., and the fifth (2a102) and subsequent drivers of the drivers 2a1, 2a2 ,. They are connected in order. On the other hand, 2b101, 2b201, 2b102,... Are combined two by two and are sequentially connected to the drivers 2b1, 2b2,.

Look electrode when the electrode is also in the configuration, the potential of the disposed conductive member at both end portions both + V ₀ of the electrodes 1001 and 1002 100
A potential of + V ₀ is applied to 1,1002. That is, the electrode 1001
To give + V ₀ only to the drive unit, first
In the driver 200b, the driver 2b1 has a potential of + V ₀ , and the other drivers 2b2 to 2b4 have a potential of −V ₀ . Here, assuming that the drive unit 200a sets the potential of the driver 2a1 to + V ₀ and the other driver 2a2 to the potential −V ₀ of 2a4, only the electrode 1001 becomes the potential + V ₀ , 1002 is ₀ , 1003 and 1004 are −V ₀ , 1005 , 1006
Is ₀ , 1007 is −V ₀ , 1008, 1009 is ₀ , 1010 to 1015 is −
The electric potential of each electrode is determined such that V ₀ and 1016 are 0.

Furthermore, the potential of only again + V ₀ driver 2b1 by the drive unit 200b, the potential of the other drivers 2b2~2b4 and -V _0, at the same time as the potential of only the + V ₀ driver 2a2, if other and -V _0, Only the electrode 1002 has the potential + V ₀ , and the other electrodes have the potential of 0 or −V ₀ . Similarly, the selected driver is 1003 for 2b2 and 2a2, 1004 for 2b2 and 2a3, 1005 for 2b1 and 2a3, 1006 and 2b for 2b1 and 2a4
The selection potential V _SS = + V ₀ is applied only to 1007 in the case of 2 and 2a4 and 1008 in the case of 2b2 and 2a1, respectively.

Next, a case where the electrodes 1001, 1002, ... Are used as information electrodes will be described as in the above-described embodiment.

First, the drive unit 200b, a potential of only the + V ₀ driver 2b1, the other with -V _0. At this time, in synchronization with this, the drivers 2a1 to 2a4 are respectively driven by + V ₀ according to the signals.
Or −V ₀ potential, the scanning electrodes 1001, 1002 and 100
Of the 5,1006, + V ₀ is given only to the selected electrode. Further, only the driver 2b2 is set to + V ₀ by the drive unit 200b.
Driver 2a1 by the drive unit 200a
By giving the + V ₀ or -V ₀ in response to each signal ～2A4, becomes as + V ₀ only electrode selected among the scan electrodes 1003 and 1004 and 1007 and 1008 are given.

Also in the above driving method, 16 lines can be driven by 8 drivers, and in order to drive n lines, for example, if X drivers are provided in the drive unit 200a, 2 × n / 2 is provided in the drive unit 200b. It is sufficient if there are / x = n / x drivers, and the total number of drivers is X + as in the previous embodiment.
It becomes n / x.

In each of the above embodiments, the potentials applied to the conductors 3 and 4 in FIG. 7 are set to + V ₀ and −V ₀ to simplify the description.
And the potential of the first electrode 1 (1001, 1002, ...) Is V _SS = +
V ₀ , V _SNS1 = 0, V _SNS2 = −V _0, and the second electrode 11 (11
001,11002, ...), but the potential has been described as a _{V IS = -V 0, V INS} = 0, the first electrode 1, the potential applied to the second electrode 11, the various range capable of driving an optical modulation device It goes without saying that it can take a value. Further, for example, in the above embodiment, the second
The potential of the electrode 11 is modulated between V _{IS and} V _INS in accordance with a signal according to a signal so that the magnitude of the potential is multi-valued or analog-modulated, and the magnitude of V _SS applied to the first electrode 1 can be similarly modulated. ,
It is also possible to modulate the selection signal of the potential applied to the conductor 4, and by doing so, it is possible to express an image having a halftone.

Further, in the above-described embodiment, the case where only one electrode sandwiching the optical modulation substance is driven in matrix has been described, but the other counter electrode can also be driven in matrix by the same configuration. At this time, for example, if V _{SS of} one electrode is + V ₀ , V _SNS1 is 0, and V _SNS2 is −V ₀ , V _SS ′ of the other electrode is −V ₀ , V _SNS1 ′ is 0, V _SNS2 ′
Can be driven by setting V to + V ₀ .

Furthermore, if the potential gradient type gray cell proposed by the present applicant in Japanese Patent Application No. 60-266980 is used as one of the electrodes, an optical modulation element suitable for expressing a halftone can be obtained.

[Effects of the Invention] As described above, according to the present invention, a plurality of conductors are arranged at both ends in the longitudinal direction on a conductive film forming an electrode surface via a resistor, and each conductor is By applying a potential corresponding to the combination of potentials applied to the conductive film between the conductors, a substantially uniform potential can be obtained over the entire surface of the electrode separated by the conductor. , A stable potential can be applied even when a part of the surface is torn. Further, according to the present invention, the number of drivers for driving each electrode can be significantly reduced, and the cost of each signal supply unit can be reduced.

[Brief description of the drawings]

1 and 2 are a longitudinal sectional view and a plan view of one embodiment of the present invention, FIGS. 3 and 4 are explanatory diagrams of potential application in the present invention, and FIG. 5 is an equivalent circuit diagram of FIG. 6, FIG. 6 is a plan view of the electrode surface, FIG. 7 (a) is a schematic diagram of electrode wiring, FIG. 7 (b) is an explanatory diagram of potential, and FIG. 8 is a circuit configuration showing one embodiment of the present invention. FIG. 9, FIG. 9 is a circuit configuration diagram showing another embodiment of the present invention, FIG. 10 is a diagram showing an electrode configuration of a conventional example, and FIGS. 11 and 12 are schematic diagrams of a ferroelectric liquid crystal cell. . 1: First electrode, 2: Resistor, 3, 4: Conductor, 5a, 5b: Base, 6a to 6c: Power supply, 10: Modulating substance, 11: Second electrode, 100, 200a, 200b: Drive unit, 2a1 to 2a4, 2b1-2b4: Driver, 1001,1002,1003 ...｝ (scan or information electrode) 11001,11002,11003, ...｝ (scan or information electrode)

Claims (9)

(57) [Claims] 1. A first substrate having a first electrode group in which a pair of conductors are provided at both ends in the longitudinal direction of a plurality of stripe-shaped conductive films, and a second substrate intersecting the longitudinal direction. A second substrate having an electrode, an optical modulation substance arranged between the first and second substrates, and a pair of conductors each independently applying a potential selected from a plurality of reference potentials to the pair of conductors. A first power source for applying a predetermined potential to the conductive film by a combination of the potentials applied to the conductor, and a second power source for applying a predetermined potential to the second electrode. In the provided optical modulation element, the resistance is sufficiently higher than the resistance of the conductive film so that a substantially uniform potential is applied between the conductive film and the pair of conductors in the width direction of the conductive film. An optical modulator comprising a resistor having a resistance interposed therebetween. 2. The optical modulation element according to claim 1, wherein the conductive film is a transparent conductive film. 3. The optical modulation element according to claim 1, wherein the resistor is made of a material selected from metal-doped Si, Se and polyester containing conductive fine powder. 4. The optical modulation element according to claim 1, wherein the conductor is Al or Au. 5. The optical modulation element according to claim 1, wherein said optical modulation substance is a chiral smectic liquid crystal. 6. The optical modulation element according to claim 1, wherein the optical modulation substance is a ferroelectric liquid crystal. 7. The first power source includes a first drive unit to which one of the pair of conductors is connected, and a second drive unit to which the other of the pair of conductors is connected. 2. The optical modulator according to item 1, wherein 8. The plurality of first electrodes are divided into a plurality of groups, and one of the pair of conductors in each group is connected to a plurality of output terminals of the first drive unit, respectively. The optical modulation element according to claim 7, wherein the other of the pair of conductors in the group is commonly connected to one output terminal of the second drive unit. 9. A first substrate having a first electrode group in which a pair of conductors are provided at both longitudinal ends of a plurality of striped conductive films, and a second substrate intersecting the longitudinal direction. In a method for driving an optical modulation element, which comprises a second substrate having an electrode and an optical modulation substance arranged between the first and second substrates, the conductive film and the conductive film are used as the first electrode. A resistor having a resistance sufficiently higher than the resistance of the conductive film is interposed between the pair of conductors, and the pair of conductors are independently selected from a plurality of reference potentials. By applying a substantially uniform potential in the width direction of the conductive film by applying a combination of the potentials applied to the pair of conductors, and applying a predetermined potential to the second electrode. Of the optical modulation element characterized by changing the state of the optical modulation substance Dynamic way.