JPH0621907B2 - Driving method for liquid crystal display - Google Patents
Driving method for liquid crystal displayInfo
- Publication number
- JPH0621907B2 JPH0621907B2 JP60212983A JP21298385A JPH0621907B2 JP H0621907 B2 JPH0621907 B2 JP H0621907B2 JP 60212983 A JP60212983 A JP 60212983A JP 21298385 A JP21298385 A JP 21298385A JP H0621907 B2 JPH0621907 B2 JP H0621907B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- voltage
- crystal display
- heat
- heating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Liquid Crystal (AREA)
- Liquid Crystal Display Device Control (AREA)
Description
【発明の詳細な説明】 〔発明の利用分野〕 本発明は、熱−電気光学効果を用いた液晶表示装置に係
り、特に、良好な表示装置を得るのに好適な液晶表示装
置の駆動法に関する。Description: FIELD OF THE INVENTION The present invention relates to a liquid crystal display device using a thermo-electro-optical effect, and more particularly to a method for driving a liquid crystal display device suitable for obtaining a good display device. .
液晶の熱、電気−光学効果を利用した表示装置は、米国
特許第3,796,999号あるいは第3,836,243号に詳しく記述
されている。A display device utilizing the heat and electro-optical effect of liquid crystal is described in detail in U.S. Pat. No. 3,796,999 or 3,836,243.
これらの装置は、液晶材料（例えば、スメクチツク液
晶）が封入されているセルに、レーザ光を照射して、任
意の部分を局部的に加熱し、該液晶物質の相転移温度以
上に一担昇温する過程、及びこれに続く冷却過程におい
て、電界印加の有無により、冷却後の光学的性質を制御
し、表示を達成するものである。In these devices, a cell in which a liquid crystal material (for example, smectic liquid crystal) is enclosed is irradiated with laser light to locally heat an arbitrary portion, and the temperature rises above the phase transition temperature of the liquid crystal substance. In the heating process and the subsequent cooling process, the optical properties after cooling are controlled depending on the presence / absence of an electric field applied to achieve display.
第５図は、スメクチツク液晶の熱、電気−光学効果を説
明するものである。初期状態では、液晶分子は整然と並
びに透明状態である。この状態からレーザ光等によつて
加熱し、等方性液体相になるまで温度を上げ、冷却す
る。このとき、液晶に電界Ｅを加えると、元の状態（透
過）に戻るが、電界Ｅを加えないと、散乱状態になる。FIG. 5 illustrates the thermal and electro-optical effects of smectic liquid crystals. In the initial state, the liquid crystal molecules are in an orderly and transparent state. From this state, heating is performed by laser light or the like, the temperature is raised until it becomes an isotropic liquid phase, and it is cooled. At this time, if an electric field E is applied to the liquid crystal, the liquid crystal returns to the original state (transmission), but if the electric field E is not applied, the liquid crystal becomes in a scattering state.
第６図(ａ)，(ｂ)は、前述した原理を利用したマトリク
ス型液晶表示パネルの一例を示す図である。〔“The Di
rect View Matrix Addressed Smectic AL.c.D Panel"19
82 International Research Contevencc (1982)参
照、〕行電極駆動回路１０のスイツチ素子３を閉じ、電
圧源２により電流を基板２２に設けられたヒート電極１
に流して、ジユール熱を発生させる。この熱により、ヒ
ート電極１に接する部分の液晶層２５の温度を上げ、等
方性液体相にする。次にスイツチ３を開き、通電を止め
ると、液晶は冷却過程に入る。このときに電極１と対向
基板２１にある電極４間に、例電極駆動回路３１からス
イツチ素子５により電圧を選択的に印加すると、電圧が
加わつた部分の液晶層は、元の透過状態になり、電圧が
加わらなかつた部分の液晶層は散乱状態になる。以上の
原理により、光学情報を表示することができる。6 (a) and 6 (b) are diagrams showing an example of a matrix type liquid crystal display panel utilizing the above-mentioned principle. [“The Di
rect View Matrix Addressed Smectic AL.cD Panel "19
82 International Research Contevencc (1982)], the switch element 3 of the row electrode drive circuit 10 is closed, and a current is provided to the substrate 22 by the voltage source 2
And heat it to generate fever heat. Due to this heat, the temperature of the liquid crystal layer 25 in the portion in contact with the heat electrode 1 is raised to make it an isotropic liquid phase. Next, when the switch 3 is opened and the energization is stopped, the liquid crystal enters the cooling process. At this time, when a voltage is selectively applied from the example electrode drive circuit 31 by the switch element 5 between the electrode 1 and the electrode 4 on the counter substrate 21, the liquid crystal layer of the part to which the voltage is applied becomes the original transmissive state. , The liquid crystal layer where no voltage is applied becomes a scattering state. Based on the above principle, optical information can be displayed.
ところで、このマトリクス型液晶表示装置において、ス
イツチ素子３を順次閉じて、ヒート電極１を順次加熱す
る。この加熱エネルギーの供給源として直流電圧源２を
使用しているが、電源側の表示品質が悪くなるという問
題があつた。この現象は、第７図によつて次のように説
明することができる。By the way, in this matrix type liquid crystal display device, the switch elements 3 are sequentially closed and the heat electrodes 1 are sequentially heated. Although the DC voltage source 2 is used as a supply source of this heating energy, there is a problem that the display quality on the power source side is deteriorated. This phenomenon can be explained as follows with reference to FIG.
第７図において、(ａ)は、加熱時にスイツチ素子端に発
生する電圧ＶＶ、(ｂ)は液晶層に印加する電圧ＶLC、
(ｃ)は液晶の透過率Ｔを示したものである。このうち
(ｂ)の(Ｈ)は、スイツチ素子３に近い部分、(Ｍ)は中央
部、(Ｌ)は共通端部の電圧を示している。なお、この説
明では、列電極駆動回路３１のスイツチ素子５により、
列電極４の電位は０であるとする。In FIG. 7, (a) is the voltage V V generated at the switch element end during heating, (b) is the voltage V LC applied to the liquid crystal layer,
(c) shows the transmittance T of the liquid crystal. this house
In (b), (H) indicates a portion near the switch element 3, (M) indicates a central portion, and (L) indicates a common end voltage. In this description, the switch element 5 of the column electrode drive circuit 31 causes
The potential of the column electrode 4 is 0.
まず、ヒート電極１の加熱直後の液晶印加電圧は、ヒー
ト電極１の抵抗による電圧降下のため、各部ともそれぞ
れ図のような電圧となり、その後の加熱時間ｔＨの間に
次第に減衰する。これは、実際の液晶パネルではガラス
基板と液晶層の間に配向制御膜が介在しているためであ
る。このｔＨの期間では、液晶が加熱状態にあり、等方
性液体相となつているため、透過率Ｔは高くなつてい
る。First, the liquid crystal applied voltage immediately after heating the heat electrode 1 becomes a voltage as shown in the figure due to the voltage drop due to the resistance of the heat electrode 1, and gradually attenuates during the subsequent heating time t H. This is because in the actual liquid crystal panel, the alignment control film is interposed between the glass substrate and the liquid crystal layer. During this period of t H , the liquid crystal is in a heated state and is in an isotropic liquid phase, so the transmittance T is high.
さて、加熱が終了後には、上記の説明と同様の現象によ
り、図のような波形の電圧が液晶層に印加することにな
る。すなわち、加熱後の冷却過程においても、液晶層に
は、スイツチ素子側部、中央部及び共通制御側部には、
それぞれ異なつた電圧が印加していることになる。特
に、スイツチ素子側部には、比較的高い電圧が残つてい
る。したがつて、その表示原理により、たとえ列電極の
電位が０であつても、図(ｃ)のように透過率Ｔに差異が
生じ、表示品質が低下する原因となる。Now, after the heating is completed, a voltage having a waveform as shown in the figure is applied to the liquid crystal layer due to the same phenomenon as described above. That is, even in the cooling process after heating, the liquid crystal layer, the switch element side portion, the central portion and the common control side portion,
It means that different voltages are applied to each. In particular, a relatively high voltage remains on the side of the switch element. Therefore, due to the display principle, even if the potential of the column electrode is 0, there is a difference in the transmittance T as shown in FIG.
本発明の目的は、熱、電気−光学効果を有する液晶を用
いたマトリクス型表示装置において、輝度むらをなくし
て表示品質を良好にした液晶表示装置の駆動法を提供す
ることにある。An object of the present invention is to provide a driving method of a liquid crystal display device in which a display quality is improved by eliminating uneven brightness in a matrix display device using a liquid crystal having a heat and electro-optical effect.
本発明は、上記原理に基いた液晶表度装置において、直
流電圧源により加熱した場合には、液晶層に、加熱後に
残留電圧があるため、高電圧印加側の表示品質が悪くな
るという問題に鑑み、この残留電圧を少なくするため、
例えば交流電圧源で加熱することにより、表示品質の低
下防止を図つたものである。The present invention, in a liquid crystal display device based on the above principle, when heated by a DC voltage source, there is a residual voltage in the liquid crystal layer after heating, there is a problem that the display quality on the high voltage application side deteriorates. In view of this, in order to reduce this residual voltage,
For example, by heating with an AC voltage source, the display quality is prevented from being degraded.
本発明の一実施例を第１図及び第２図を用いて説明す
る。An embodiment of the present invention will be described with reference to FIGS. 1 and 2.
第１図において、液晶パネルの構成及び列電極駆動回路
３１部の構成は、第６図と全く同様である。行電極駆動
回路１０は、双方向スイツチ素子３３群から成る。ま
た、３４は、第２図(ａ)に示す波形の電圧を発生する加
熱電圧発生源である。In FIG. 1, the configuration of the liquid crystal panel and the configuration of the column electrode drive circuit 31 section are exactly the same as in FIG. The row electrode drive circuit 10 is composed of a group of bidirectional switch elements 33. Further, 34 is a heating voltage generating source for generating a voltage having a waveform shown in FIG.
この構成の表示装置の表示タイミングは、第３図に示す
ように、行電極駆動回路１０のスイツチ素子３３を順次
閉じて、ヒート電極１に のように±ＶＨの電圧を印加して順次加熱する。一方、
列電極４には列電極駆動回路３１から表示情報に応じて
スイツチ素子５を選択的に開閉して、 のような±ＶＷの振幅の電圧又は０電圧を印加する。The display timing of the display device having this configuration is as shown in FIG. 3, in which the switch element 33 of the row electrode drive circuit 10 is sequentially closed and the heat electrode 1 is displayed. Then, a voltage of ± V H is applied to heat sequentially. on the other hand,
The switch element 5 is selectively opened and closed on the column electrode 4 according to display information from the column electrode drive circuit 31. A voltage having an amplitude of ± V W or 0 voltage is applied.
したがつて、その表示原理によりヒート電極１と列電極
４の交叉部の画素に透過率の差が生じて表示することが
できる。Therefore, due to the display principle, the pixel at the intersection of the heat electrode 1 and the column electrode 4 has a difference in transmittance and can be displayed.
このようにすれば、加熱電圧として第２図(ａ)に示すよ
うな±ＶＨの交流電圧を印加して、ヒート電極１を加熱
している。したがつて、スイツチ素子３３端側の液晶層
には、第２図(ｂ)に示すような電圧を印加することにな
る。すなわち、ヒート電極の加熱後に、液晶層にわずか
な電圧が発生するだけなので、列電極から印加する電圧
によつてのみ表示状態が決定する。したがつて、本実施
例によれば、、表示品質の低下を防止できるという効果
が得られる。なお、上述のわずかな電圧とは、液晶の透
過率が変化する電圧以下、すなわち、しきい値電圧詞下
の電圧である。By doing so, the heating electrode 1 is heated by applying an AC voltage of ± V H as shown in FIG. 2A as the heating voltage. Therefore, a voltage as shown in FIG. 2B is applied to the liquid crystal layer on the end side of the switch element 33. That is, since only a slight voltage is generated in the liquid crystal layer after heating the heat electrode, the display state is determined only by the voltage applied from the column electrode. Therefore, according to this embodiment, it is possible to obtain the effect of preventing the deterioration of the display quality. The above-mentioned slight voltage is equal to or lower than the voltage at which the transmittance of the liquid crystal changes, that is, a voltage below the threshold voltage.
第４図(ａ)は、加熱電圧として他の実施例を示すもので
ある。この実施例では、ヒート電極１の加熱時間ｔ
Ｈを、前半 と後半 に分け、さらに加熱電圧を に分けている。そして、 として、後半のｔＨで同図(ｂ)に示すように、液晶層に
印加する残留電圧を少なくするようにしている。FIG. 4 (a) shows another embodiment as the heating voltage. In this embodiment, the heating time t of the heat electrode 1 is
H in the first half And the second half The heating voltage It is divided into And As a result, at the latter half t H , the residual voltage applied to the liquid crystal layer is reduced as shown in FIG.
本実施例でも、第１の実施例と全く同じ効果が得られ
る。Also in this embodiment, the same effect as in the first embodiment can be obtained.
以上の実施例では、加熱電圧として、方形波の電圧で説
明したが、これらの波形に限定されるものではな、加熱
後に液晶に印加する電圧がしきい値電圧になれば良いも
のである。すなわち、第８図は液晶表示装置の１画素当
りの電気的等価回路を示す図である。同図において、Ｃ
Ａ，ＲＡは配向制御膜の静電容量、抵抗を表わし、
ＣＬ，ＲＬは液晶の静電容量、抵抗を表わす。またＶＬ
は、液晶に印加する電圧であり、液晶表示装置では、端
子Ｘが行電極、端子Ｙが列電極となりＸ，Ｙに電圧を印
加して表示制御を行う。そして、第９図は、端子Ｘ，Ｙ
間にステツプ電圧ＶXYを印加した場合の液晶に印加する
電圧ＶＬを示したものである。スメクチツク液晶表示装
置では、その表示過程により、加熱後、すなわちｔ＞ｔ
１での液晶印加電圧 が問題となり、ｔ＞ｔ１における は次式で表わせる。In the above embodiments, the square wave voltage was used as the heating voltage. However, the heating voltage is not limited to these waveforms, and the voltage applied to the liquid crystal after heating may be the threshold voltage. That is, FIG. 8 is a diagram showing an electrically equivalent circuit per pixel of the liquid crystal display device. In the figure, C
A and RA represent the capacitance and resistance of the orientation control film,
C L and R L represent the capacitance and resistance of the liquid crystal. Also VL
Is a voltage applied to the liquid crystal. In the liquid crystal display device, the terminal X serves as a row electrode and the terminal Y serves as a column electrode to apply a voltage to X and Y to perform display control. And FIG. 9 shows terminals X and Y.
The voltage VL applied to the liquid crystal when the step voltage V XY is applied in between is shown. In the smectic liquid crystal display device, due to the display process, after heating, that is, t> t.
Liquid crystal applied voltage at 1 Becomes a problem, and at t> t 1 Can be expressed by the following equation.
ただし、 上式において、ＣAＲA＝ＣLＲLとすると、ＶＬ＝０とな
る。すなわち、加熱後の液晶印加電圧ＶＬを０にするこ
とができる。 However, In the above equation, if C A R A = C L R L , then VL = 0. That is, the liquid crystal applied voltage VL after heating can be set to zero.
ここで、ＣＡ，ＲＡ，ＣＬ，ＲＬは材料の物性定数や素
子構造から決まる値であるが、材料の選定や組成物の改
良により、変えることができることになる。したがつ
て、これらのことにより、直流電圧によつて加熱した場
合でも、表示品質の低下を防止することが可能になる。Here, C A , R A , C L , and R L are values determined by the physical constants of the material and the device structure, but can be changed by selecting the material and improving the composition. Therefore, due to the above, it becomes possible to prevent the deterioration of the display quality even when heated by the DC voltage.
以上説明したように本発明による液晶表示装置の駆動法
によれば、加熱後に液晶に印加する残留電圧を少なくす
ることができるので、輝度むらをなくして表示品質を良
好にする効果がある。As described above, according to the driving method of the liquid crystal display device of the present invention, it is possible to reduce the residual voltage applied to the liquid crystal after heating, so that it is possible to eliminate uneven brightness and improve display quality.
第１図は本発明の液晶表示装置の駆動法の一実施例を示
す構成図、第２図ないし第４図は本発明の液晶表示装置
の駆動法の作用を示す波形図、第５図はスメクチツク液
晶の熱い電気−光学効果を説明する図、第６図(ａ)，
(ｂ)は従来の液晶表示装置の駆動法の一例を示す構成
図、第７図は従来の液晶表示装置の駆動法の欠点を示す
説明図、第８図および第９図は本発明の液晶表示装置の
駆動法の他の実施例を示す説明図である。 １……ヒート電極、４……列電極、１０……行電極駆動
回路、３３……スイツチ素子、３４……加熱電圧発生
源。FIG. 1 is a block diagram showing an embodiment of a driving method of a liquid crystal display device of the present invention, FIGS. 2 to 4 are waveform diagrams showing the operation of the driving method of a liquid crystal display device of the present invention, and FIG. FIG. 6 (a), which illustrates the hot electro-optical effect of smectic liquid crystals.
(b) is a configuration diagram showing an example of a driving method of a conventional liquid crystal display device, FIG. 7 is an explanatory diagram showing a defect of the driving method of the conventional liquid crystal display device, and FIGS. 8 and 9 are liquid crystal of the present invention. It is explanatory drawing which shows the other Example of the drive method of a display apparatus. 1 ... Heat electrode, 4 ... Column electrode, 10 ... Row electrode drive circuit, 33 ... Switch element, 34 ... Heating voltage generation source.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 北島 雅明 茨城県日立市久慈町4026番地 株式会社日 立製作所日立研究所内 (56)参考文献 特開 昭60−181828（ＪＰ，Ａ) 特開 昭60−181829（ＪＰ，Ａ) 特開 昭60−107024（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Kitajima 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitate Manufacturing Co., Ltd. (56) References JP-A-60-181828 (JP, A) JP-A-60 -181829 (JP, A) JP-A-60-107024 (JP, A)
Claims (1)
熱、電気−光学効果によって光の散乱及び透過を生ずる
液晶表示体を設け、該行電極に電流を流して、該行電極
に接触する液晶層を一定期間加熱し、その後に続く冷却
過程にて前記行電極と前記列電極の交叉部に選択的に電
界を作用させて表示画素を形成するマトリクス液晶表示
装置の駆動法において、前記液晶層を加熱するために前
記行電極に一定期間印加する加熱電圧として、少なくと
も１周期以上の交流電圧を用いることを特徴とする液晶
表示装置の駆動法。1. Between a plurality of row electrodes and a plurality of row electrodes,
A liquid crystal display that causes light scattering and transmission due to heat and electro-optical effects is provided, and a current is applied to the row electrode to heat the liquid crystal layer in contact with the row electrode for a certain period of time, and in the subsequent cooling process. In a driving method of a matrix liquid crystal display device in which a display pixel is formed by selectively applying an electric field to an intersection of the row electrode and the column electrode, heating applied to the row electrode for a certain period in order to heat the liquid crystal layer. A method for driving a liquid crystal display device, characterized in that an alternating voltage of at least one cycle is used as the voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60212983A JPH0621907B2 (en) | 1985-09-26 | 1985-09-26 | Driving method for liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60212983A JPH0621907B2 (en) | 1985-09-26 | 1985-09-26 | Driving method for liquid crystal display |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6271933A JPS6271933A (en) | 1987-04-02 |
| JPH0621907B2 true JPH0621907B2 (en) | 1994-03-23 |
Family
ID=16631523
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60212983A Expired - Lifetime JPH0621907B2 (en) | 1985-09-26 | 1985-09-26 | Driving method for liquid crystal display |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0621907B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9071872B2 (en) | 2003-01-30 | 2015-06-30 | Rovi Guides, Inc. | Interactive television systems with digital video recording and adjustable reminders |
| US9075861B2 (en) | 2006-03-06 | 2015-07-07 | Veveo, Inc. | Methods and systems for segmenting relative user preferences into fine-grain and coarse-grain collections |
| US9118948B2 (en) | 1998-07-14 | 2015-08-25 | Rovi Guides, Inc. | Client-server based interactive guide with server recording |
| US9125169B2 (en) | 2011-12-23 | 2015-09-01 | Rovi Guides, Inc. | Methods and systems for performing actions based on location-based rules |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10884278B2 (en) * | 2017-10-24 | 2021-01-05 | Palo Alto Research Center Incorporated | Liquid crystal temperature control by resistive heating |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60181829A (en) * | 1984-02-29 | 1985-09-17 | Hitachi Ltd | image information device |
| JPS60181828A (en) * | 1984-02-29 | 1985-09-17 | Hitachi Ltd | image information device |
-
1985
- 1985-09-26 JP JP60212983A patent/JPH0621907B2/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9118948B2 (en) | 1998-07-14 | 2015-08-25 | Rovi Guides, Inc. | Client-server based interactive guide with server recording |
| US9071872B2 (en) | 2003-01-30 | 2015-06-30 | Rovi Guides, Inc. | Interactive television systems with digital video recording and adjustable reminders |
| US9075861B2 (en) | 2006-03-06 | 2015-07-07 | Veveo, Inc. | Methods and systems for segmenting relative user preferences into fine-grain and coarse-grain collections |
| US9092503B2 (en) | 2006-03-06 | 2015-07-28 | Veveo, Inc. | Methods and systems for selecting and presenting content based on dynamically identifying microgenres associated with the content |
| US9128987B2 (en) | 2006-03-06 | 2015-09-08 | Veveo, Inc. | Methods and systems for selecting and presenting content based on a comparison of preference signatures from multiple users |
| US9125169B2 (en) | 2011-12-23 | 2015-09-01 | Rovi Guides, Inc. | Methods and systems for performing actions based on location-based rules |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6271933A (en) | 1987-04-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4692779A (en) | Image forming method and apparatus therefor | |
| US4499458A (en) | Liquid crystal display device associating two addressing modes | |
| GB1529197A (en) | Thermo-optic liquid-crystal device for real-time display of animated images | |
| JPH0827460B2 (en) | Optical modulator | |
| JPH0525095B2 (en) | ||
| JPH0621907B2 (en) | Driving method for liquid crystal display | |
| US5724059A (en) | Method for driving optical modulation device | |
| JPS6120017A (en) | Liquid-crystal display device | |
| JP2566149B2 (en) | Optical modulator | |
| JPS61166523A (en) | Image forming device | |
| JP2536157B2 (en) | Liquid crystal display | |
| JPH02154229A (en) | Liquid crystal light valve and how to drive the liquid crystal light valve | |
| JP2614220B2 (en) | Display device | |
| JPS61296331A (en) | Image display device | |
| JPS6250733A (en) | liquid crystal display device | |
| JPH06337422A (en) | Liquid crystal electro-optical device | |
| JPS58198092A (en) | Liquid crystal display | |
| JP2640265B2 (en) | Driving method of ferroelectric liquid crystal device | |
| JPS59187323A (en) | Driving method of liquid crystal display element | |
| JPH01182828A (en) | Liquid crystal display panel | |
| JPH01189634A (en) | Liquid crystal display device | |
| JPS60209779A (en) | Liquid crystal display unit | |
| JPS60262137A (en) | Driving method of liquid-crystal element | |
| JPS62238533A (en) | Driving method of optical modulation element | |
| JPS6457236A (en) | Optical modulating element and driving method thereof |