JPH1124634A - Liquid crystal display - Google Patents
Liquid crystal displayInfo
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- JPH1124634A JPH1124634A JP17438997A JP17438997A JPH1124634A JP H1124634 A JPH1124634 A JP H1124634A JP 17438997 A JP17438997 A JP 17438997A JP 17438997 A JP17438997 A JP 17438997A JP H1124634 A JPH1124634 A JP H1124634A
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- Prior art keywords
- voltage
- liquid crystal
- polarity
- crystal display
- inversion
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は液晶表示装置とくに
その駆動方式に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display and, more particularly, to a driving system thereof.
【０００２】[0002]
【従来の技術】ＯＡ機器例えばワードプロセッサーやパ
ーソナルコンピュータ用のフラットパネル表示装置に
は、表示面積の拡大化と精細度向上がの望まれ、近年で
は、大きさは１０．４''サイズから１２．１''サイズ
が、また画素数はＶＧＡ（６４０×４８０）、ＳＶＧＡ
（８００×６００）、ＸＧＡ（１０２４×７６８）、さ
らにそれ以上の画素数の表示装置が製品化されている。2. Description of the Related Art In flat panel display devices for OA equipment, for example, word processors and personal computers, it is desired to increase the display area and improve the definition. 1 '' size, the number of pixels is VGA (640 × 480), SVGA
(800 × 600), XGA (1024 × 768), and a display device having a larger number of pixels have been commercialized.
【０００３】一方、これらの用途は携帯形が主で、電池
による長時間動作が可能であることが望まれる。液晶デ
ィスプレイは駆動電圧が低いことから、プラズマディス
プレイやＥＬディスプレイにくらべて格段に消費電力が
小さい。しかしながら、電池駆動の携帯機器において
は、液晶ディスプレイの消費電力は全体の３割と大き
い。On the other hand, these applications are mainly of a portable type, and it is desired that they can be operated for a long time by a battery. Since a liquid crystal display has a low driving voltage, it consumes much less power than a plasma display or an EL display. However, in a battery-powered portable device, the power consumption of the liquid crystal display is as large as 30% of the whole.
【０００４】そこで、液晶パネルを駆動するドライバＩ
Ｃの低消費電力化や電源回路の効率改善、液晶パネルを
照明するバックライトの効率改善により低消費電力化が
なされてきた。Accordingly, a driver I for driving a liquid crystal panel is provided.
Power consumption has been reduced by reducing the power consumption of C, improving the efficiency of the power supply circuit, and improving the efficiency of the backlight for illuminating the liquid crystal panel.
【０００５】しかし、これだけの改善では限界が来てお
り液晶パネルを駆動するための消費電力の低減も必要に
なってきている。図１０に電圧波形を示すように、液晶
ディスプレイは液晶の劣化を防ぐために、１フレーム期
間さらに１水平期間毎に各画素の電極電圧（画素電極電
圧−コモン電極間電圧）の極性を反転するフレーム反転
駆動を行っており、フレーム反転周波数や駆動電圧を高
くすると消費電力が増大する。液晶パネルを駆動する電
力の低減には、低電圧で動作する液晶を使う方法、駆動
周波数を下げる方法が取られてきた。[0005] However, these improvements have reached their limits, and it is necessary to reduce the power consumption for driving the liquid crystal panel. As shown in the voltage waveform in FIG. 10, the liquid crystal display has a frame in which the polarity of the electrode voltage (pixel electrode voltage-common electrode voltage) of each pixel is inverted every frame period and every horizontal period in order to prevent the deterioration of the liquid crystal. Inversion driving is performed, and when the frame inversion frequency or the driving voltage is increased, power consumption increases. In order to reduce the power for driving the liquid crystal panel, a method of using a liquid crystal operating at a low voltage and a method of lowering the driving frequency have been adopted.
【０００６】[0006]
【発明が解決しようとする課題】しかし、上記の様な従
来の方法を用いた表示装置は、経時的に表示ムラが発生
したり、フリッカが発生するといった問題があった。こ
れは、低電圧動作の液晶は組成が変化しやすい特性をも
つからである。また、駆動周波数が低い場合には液晶の
ちょっとした組成変化も画面のフリッカに現れ易くなる
り問題となる。However, the display device using the conventional method as described above has a problem that display unevenness occurs over time and flicker occurs. This is because the composition of a liquid crystal operated at a low voltage tends to change. In addition, when the driving frequency is low, a slight change in the composition of the liquid crystal tends to appear on the screen as flicker.
【０００７】本発明はこのような問題を解決するために
成されたもので、その目的は、簡易な手段によって、低
消費電力の液晶表示装置を提供することにある。The present invention has been made to solve such a problem, and an object of the present invention is to provide a low power consumption liquid crystal display device by simple means.
【０００８】[0008]
【課題を解決するための手段】本発明は、複数の信号線
と複数の走査線とを備え、液晶層を挟み込む様に配置さ
れた電極を含む複数の画素を有する液晶表示パネルと、
前記信号線と走査線に前記画素の駆動電圧を印加する電
圧印加手段と、１フレーム期間以上の時間単位で前記画
素に印加する駆動電圧の極性を反転する極性反転手段と
を具備する液晶表示装置において、前記各画素を第１の
複数フレーム期間にわたって同一極性の電圧で駆動する
手段と、次の第２の複数フレーム期間では前記各画素電
圧を極性反転して駆動する手段と、前記第１および第２
の複数フレーム期間中に１または複数のフレーム期間毎
に、印加される駆動電圧を徐々に遷移、変化させる手段
とを具備することを特徴とする液晶表示装置を得るもの
である。According to the present invention, there is provided a liquid crystal display panel having a plurality of pixels including a plurality of signal lines and a plurality of scanning lines, and including a plurality of electrodes disposed so as to sandwich a liquid crystal layer.
A liquid crystal display device comprising: voltage applying means for applying a driving voltage of the pixel to the signal line and the scanning line; and polarity inverting means for inverting the polarity of the driving voltage applied to the pixel in a time unit of one frame period or more. A means for driving each pixel with a voltage of the same polarity over a first plurality of frame periods; a means for driving each pixel voltage by inverting the polarity of each pixel voltage in a next second plurality of frame periods; Second
Means for gradually changing and changing the applied driving voltage every one or a plurality of frame periods during the plurality of frame periods.
【０００９】さらに、複数フレーム期間に画素の液晶層
に発生した残留電圧を次の複数フレーム期間に印加され
前記駆動電圧と異なる値に遷移された駆動電圧により相
殺して、前記液晶層にかかる電圧がどのフレーム期間と
もにほぼ等しくなる様にしたことを特徴とする上記液晶
表示装置を得るものである。Further, the residual voltage generated in the liquid crystal layer of the pixel during a plurality of frame periods is canceled by the drive voltage applied to the next plurality of frame periods and shifted to a value different from the drive voltage, and the voltage applied to the liquid crystal layer is reduced. The above liquid crystal display device is characterized in that each of the frame periods is substantially equal in every frame period.
【００１０】これにより液晶層に発生した残留電圧を相
殺して、液晶層にかかる電圧が常にほぼ等しくなる様に
する。Thus, the residual voltage generated in the liquid crystal layer is canceled, so that the voltage applied to the liquid crystal layer always becomes substantially equal.
【００１１】さらに、極性が反転される際の電圧の遷移
量を液晶層に印加される電圧が大きい程大きくすること
を特徴とする上記液晶表示装置を得るものである。Further, the liquid crystal display device according to the present invention is characterized in that the amount of voltage transition when the polarity is reversed is increased as the voltage applied to the liquid crystal layer is increased.
【００１２】さらに、隣接する画素の液晶層に印加され
る電圧は互いに逆極性であることを特徴とする上記液晶
表示装置を得るものである。Further, the liquid crystal display device according to the present invention is characterized in that voltages applied to liquid crystal layers of adjacent pixels have opposite polarities.
【００１３】本発明の液晶表示装置の駆動では、液晶を
駆動する電圧は一定期間（複数フレーム期間、Ｎフレー
ム、Ｎ：２以上の自然数）の間、極性反転しないから、
極性反転のための放電、充電電流は流れない。極性反転
しない期間がＮフレームと長いことが消費電流の抑制と
フリッカ頻度抑制に作用する。In driving the liquid crystal display device of the present invention, the voltage for driving the liquid crystal is not inverted for a certain period (a plurality of frame periods, N frames, N: a natural number of 2 or more).
No discharging or charging current flows for polarity reversal. The fact that the period during which the polarity is not inverted is as long as N frames has an effect on suppression of current consumption and suppression of flicker frequency.
【００１４】フレーム毎に徐々に電圧を遷移させながら
の極性反転は、液晶配向層周辺に蓄積された直流的な電
圧（いわゆる残留電圧）をドライバＩＣから供給される
補正された電圧で合成して、常に液晶層にかかる電圧を
等しく維持する様に作用する。したがって極性反転の際
に発生するフリッカは除去される。The polarity inversion while gradually changing the voltage for each frame is achieved by synthesizing a DC voltage (a so-called residual voltage) accumulated around the liquid crystal alignment layer with a corrected voltage supplied from the driver IC. Operates so as to always maintain the voltage applied to the liquid crystal layer equal. Therefore, flicker generated at the time of polarity inversion is eliminated.
【００１５】さらに、隣接する画素で極性を逆にすると
極性反転時のフリッカは完全に相殺される。Further, when the polarity is reversed between adjacent pixels, flicker at the time of polarity reversal is completely canceled.
【００１６】なお、液晶の残留電圧は、同一極性が印加
される時間（Ｎフレーム期間）はもとより表示する階調
（液晶印加電圧）によっても変化するので、ドライバＩ
Ｃから液晶に印加する電圧（補正電圧）の遷移量は階調
毎に設定する。The residual voltage of the liquid crystal varies not only with the time (N-frame period) when the same polarity is applied but also with the gradation (liquid crystal applied voltage) to be displayed.
The transition amount of the voltage (correction voltage) applied from C to the liquid crystal is set for each gradation.
【００１７】図５および図６に示すように、液晶表示パ
ネル１はマトリクス配列の多数の画素２を有し、その各
画素２を構成する画素電極３、この電極に接続されたＴ
ＦＴスイッチング素子４、この素子に信号電圧を印加す
る信号線５、この素子にスイッチ電圧を印加する走査線
６を備えたアレイ基板７と、対向して配置され透明コモ
ン電極８を形成した対向基板９を有している。As shown in FIGS. 5 and 6, the liquid crystal display panel 1 has a large number of pixels 2 arranged in a matrix, a pixel electrode 3 constituting each pixel 2, and a T electrode connected to this electrode.
An FT switching element 4, an array substrate 7 including a signal line 5 for applying a signal voltage to the element, a scanning line 6 for applying a switch voltage to the element, and a counter substrate disposed to face and forming a transparent common electrode 8 9.
【００１８】両基板の電極表面には絶縁性の配向膜１
０、１１が塗布され、基板間に液晶層１２が挟持されて
いる。An insulating alignment film 1 is provided on the electrode surfaces of both substrates.
0 and 11 are applied, and a liquid crystal layer 12 is sandwiched between the substrates.
【００１９】スイッチング素子４がオンとなり、画素電
極３とコモン電極８間に駆動電圧が印加されると、印加
電圧は配向膜１０、１１を通して液晶層領域１２にかか
る。図６のように、画素は、画素電極３とコモン電極８
間に、画素電極側の配向膜容量Ｃ10、液晶層容量Ｃ11、
コモン電極側の配向膜容量Ｃ12が直列接続された等価回
路となる。When the switching element 4 is turned on and a driving voltage is applied between the pixel electrode 3 and the common electrode 8, the applied voltage is applied to the liquid crystal layer region 12 through the alignment films 10 and 11. As shown in FIG. 6, the pixel includes a pixel electrode 3 and a common electrode 8.
In between, the alignment film capacitance C10 on the pixel electrode side, the liquid crystal layer capacitance C11,
It becomes an equivalent circuit in which the alignment film capacitors C12 on the common electrode side are connected in series.
【００２０】このため、電圧をオフにしても配向膜１
０、１１表面に残留電荷が残りこれが残留電圧となっ
て、つぎに極性反転した電圧を印加しても、液晶層１２
に等量の電圧を印加することができない。Therefore, even if the voltage is turned off, the alignment film 1
Residual charges remain on the surfaces 0 and 11, which become residual voltages.
Cannot be applied with the same amount of voltage.
【００２１】このために、図７に示すように、一方の極
性（正極性）の電圧印加期間と極性反転の電圧印加期間
とでは、特性が変わり、同一画素で異なる透過率Ｔ1 と
Ｔ1'になる結果、反転毎にちらつき、すなわちフリッカ
を発生することになる。For this reason, as shown in FIG. 7, the characteristics change between the voltage application period of one polarity (positive polarity) and the voltage application period of the polarity inversion, resulting in different transmittances T1 and T1 'for the same pixel. As a result, flickering, that is, flicker occurs at each inversion.
【００２２】これを緩和するために、隣接画素との透過
率平均法を用いる。図８（ａ）に示すように、第１の走
査線（奇数）上の画素に印加する電圧と隣接する第２の
走査線（偶数）上の画素に印加する電圧を逆極性（図で
は（＋）を正極、（−）を反転極とする）とし、図８
（ｂ）のように次のフレーム反転で、この関係を逆にす
る方法である。この方法によれば、一方の画素の透過率
Ｔ1 と隣接する逆極性の画素の透過率Ｔ1'の平均が目視
上の透過率となるので、見掛けのフリッカが発生しな
い。しかし、透過率が平均的に低くなり、また１フレー
ム反転と組み合わされるため反転周波数が高く、消費電
力が増大する。To alleviate this, a method of averaging transmittance with adjacent pixels is used. As shown in FIG. 8A, the voltage applied to the pixel on the first scanning line (odd number) and the voltage applied to the pixel on the adjacent second scanning line (even number) are opposite in polarity (in the figure, ( (+) Is a positive electrode, and (-) is a reverse electrode).
This method reverses this relationship in the next frame inversion as shown in FIG. According to this method, the average of the transmittance T1 of one pixel and the transmittance T1 'of the adjacent pixel of the opposite polarity is a visual transmittance, so that no apparent flicker occurs. However, the transmittance becomes low on average, and the inversion frequency is high because of the combination with one-frame inversion, and the power consumption increases.
【００２３】本発明によれば以上のような不都合を解消
する。According to the present invention, the above disadvantages are solved.
【００２４】[0024]
（実施の形態１）図１（ａ）に、本実施の形態に用いた
液晶表示装置の液晶パネル１と駆動部の回路２０、３０
の回路配置を示す。液晶パネル１は、８００×６００の
ドットの薄膜トランジスタＴＦＴをスイッチング素子に
用いたアクティブマトリクス方式液晶表示パネルであ
る。ここに符号Ｃｃは補助容量線による補助容量、符号
ＣLは液晶容量を示している。(Embodiment 1) FIG. 1A shows a liquid crystal panel 1 of a liquid crystal display device used in this embodiment and circuits 20 and 30 of a driving unit.
2 shows the circuit arrangement of FIG. The liquid crystal panel 1 is an active matrix type liquid crystal display panel using 800 × 600 dot thin film transistors TFT as switching elements. Here, reference symbol Cc indicates an auxiliary capacitance by an auxiliary capacitance line, and reference symbol CL indicates a liquid crystal capacitance.
【００２５】信号線ドライバ部２０では、シフトレジス
タ（Ｓ／Ｒ）２１がタイミングパルスＳＴＨとシフトク
ロックφ１を受けて表示データ（ＤＡＴＡ）を順次ラッ
チ２２に取り込む。全てのラッチ２２に表示データを蓄
積すると、ラッチされた表示データは水平同期信号φ２
を受けてＤ／Ａ変換部２３に出力されアナログ電圧に変
換され、バッファ２４を介して信号線５に出力される。
Ｄ／Ａ変換は、基準電圧Ｖref1とＶref2を受けてこの間
を抵抗分割するＲ−ＤＡＣ型である。これらの回路は８
００本の信号線５それぞれに用意されて接続される。In the signal line driver section 20, the shift register (S / R) 21 receives the timing pulse STH and the shift clock φ1 and sequentially takes in the display data (DATA) into the latch 22. When the display data is stored in all the latches 22, the latched display data becomes the horizontal synchronization signal φ2.
In response, the signal is output to the D / A converter 23, converted into an analog voltage, and output to the signal line 5 via the buffer 24.
The D / A conversion is of the R-DAC type which receives the reference voltages Vref1 and Vref2 and divides the resistance between them. These circuits are 8
Prepared and connected to each of the 00 signal lines 5.
【００２６】走査ドライバ部３０では、シフトレジスタ
３１が走査タイミングパルス（垂直同期信号ＳＴＶと走
査シフトクロック（水平同期信号）φ２を受けて走査タ
イミングパルスを順次シフトしていく。In the scanning driver section 30, the shift register 31 receives the scanning timing pulse (vertical synchronization signal STV and scanning shift clock (horizontal synchronization signal) φ2 and sequentially shifts the scanning timing pulse.
【００２７】スイッチ部３２では走査タイミングパルス
の有無によって電圧Ｖg2、Ｖg1が選択され、走査線６へ
出力され１ライン毎に走査パルスが出力される。このス
イッチ部３２が６００本の走査線６それぞれに用意され
て接続される。In the switch section 32, the voltages Vg2 and Vg1 are selected depending on the presence or absence of a scanning timing pulse, and the voltages are output to the scanning line 6 and the scanning pulse is output for each line. The switch unit 32 is prepared and connected to each of the 600 scanning lines 6.
【００２８】また図１（ｂ）に示すように２個のスイッ
チング素子４１、４２によるコモン電極駆動回路４０で
は、極性反転信号ＰＯＬにより電圧Ｖcom1とＶcom2が切
り替えられる。As shown in FIG. 1B, in the common electrode drive circuit 40 including two switching elements 41 and 42, the voltages Vcom1 and Vcom2 are switched by the polarity inversion signal POL.
【００２９】この様な回路に図２（ａ）に示すような本
発明の特徴とする方式を実現するための極性反転時電圧
補正部５０を搭載した。図２（ｂ）に、極性反転時電圧
補正部の出力波形を示す。In such a circuit, a polarity reversal voltage correction unit 50 for realizing a system characteristic of the present invention as shown in FIG. 2A is mounted. FIG. 2B shows an output waveform of the polarity inversion-time voltage correction unit.
【００３０】極性反転時電圧補正部５０では、極性反転
信号ＰＯＬを受け極性反転が開始されると，ＲＯＭに作
成した補正電圧データテーブル５１から水平同期φ２の
毎に順次読みだしＤ／Ａ変換部５２によりＤ／Ａ変換さ
れて、Ｖref1とＶref2として出力される。When the polarity inversion is started in response to the polarity inversion signal POL, the polarity inversion-time voltage correction unit 50 sequentially reads the correction voltage data table 51 created in the ROM for each horizontal synchronization φ2 from the D / A conversion unit. The signal is D / A-converted by 52 and output as Vref1 and Vref2.
【００３１】極性反転時電圧補正部のＶref1とＶref2の
出力波形は、液晶の種類、配向膜の種類、極性反転周
期、表示階調により決定される。液晶配向層周辺に充放
電される直流的な電圧（いわゆる残留電圧）の充放電特
性は１−ｅ（−ｔ／ＣＲ）、ｅ（−ｔ／ＣＲ）の時定数
曲線で表すことが難しい。これは充放電特性が液晶種類
・配向膜種類に大きく依存するためである。The output waveforms of Vref1 and Vref2 of the polarity reversal voltage corrector are determined by the type of liquid crystal, the type of alignment film, the polarity reversal cycle, and the display gradation. It is difficult to express the charge / discharge characteristics of the DC voltage (so-called residual voltage) charged / discharged around the liquid crystal alignment layer by the time constant curves of 1-e (-t / CR) and e (-t / CR) . This is because the charge / discharge characteristics greatly depend on the type of liquid crystal and the type of alignment film.
【００３２】本実施の形態では極性反転を３６００垂直
周期（３６００フレーム期間）として、３６００周期の
一方の極性の複数フレーム期間と、つぎに続く３６００
周期の極性反転複数フレーム期間を繰り返す。また、補
正電圧デ一タテーブル５１を液晶・配向膜を固定した液
晶パネルから実験的に求めた。また、充放電特性は表示
階調にも依存するので、黒表示と白表示について求め、
それぞれＶref1とＶref2として出力させた。In the present embodiment, the polarity inversion is 3600 vertical periods (3600 frame periods), a plurality of frame periods of one polarity of the 3600 period, and the following 3600 period.
The polarity inversion cycle is repeated for a plurality of frame periods. Further, the correction voltage data table 51 was experimentally obtained from a liquid crystal panel in which a liquid crystal and an alignment film were fixed. In addition, since the charge / discharge characteristics also depend on the display gradation, black display and white display are obtained.
These were output as Vref1 and Vref2, respectively.
【００３３】さてこのように製作した液晶表示装置の液
晶パネルの駆動電圧波形を図３に、画素印加波形を図４
に示す。図は黒表示状態における画素への印加電圧の遷
移状態を示す。FIG. 3 shows the driving voltage waveform of the liquid crystal panel of the liquid crystal display device manufactured as described above, and FIG.
Shown in The figure shows a transition state of the voltage applied to the pixel in the black display state.
【００３４】例えば信号電圧は０Ｖ〜５Ｖの範囲で変化
し、コモン電圧は−１Ｖ〜４Ｖの範囲で変化する。画素
に印加される電圧は（画素電極電圧−コモン電極電圧）
となる。For example, the signal voltage changes in a range of 0 V to 5 V, and the common voltage changes in a range of -1 V to 4 V. The voltage applied to the pixel is (pixel electrode voltage-common electrode voltage)
Becomes
【００３５】すなわち信号電圧は前記極性反転時電圧補
正部からのＶref1とＶref2を受け、極性反転直後は残留
電圧を差し引いた電圧を、その後は充放電特性に基づい
た電圧を出力する。一方のコモン電圧は極性反転信号に
同期した波形で、ゲート突き抜け電圧を差し引いた電位
とした。That is, the signal voltage receives Vref1 and Vref2 from the polarity reversal voltage correction unit, and outputs a voltage obtained by subtracting the residual voltage immediately after the polarity reversal, and thereafter outputs a voltage based on the charge / discharge characteristics. On the other hand, the common voltage had a waveform synchronized with the polarity inversion signal, and was a potential obtained by subtracting the gate penetration voltage.
【００３６】正転の第１の複数フレーム期間内で各フレ
ーム期間を経るごとに駆動電圧を大きくする。つづいて
極性反転信号により極性反転された次の第２の複数フレ
ーム期間に移行すると反転初期のフレーム期間の駆動電
圧は小さく、徐々に大となり最終フレーム期間で最大に
なるようにしている。図は説明をしやすくするために画
面が黒表示の状態の波形を示しているが、実際は白表示
から黒表示にわたる駆動電圧範囲において遷移量を決定
する。The drive voltage is increased every time each frame period within the first plurality of normal rotation frame periods. Subsequently, when a transition is made to the next second plurality of frame periods in which the polarity is inverted by the polarity inversion signal, the drive voltage in the initial inversion frame period is small, gradually increases, and is maximized in the final frame period. Although the figure shows a waveform in a state where the screen is displayed in black for ease of explanation, the transition amount is actually determined in a drive voltage range from white display to black display.
【００３７】本実施の形態の液晶表示装置は液晶パネル
を駆動する電力が１ｍＷと小さく、極性反転時のフリッ
カはほとんど発生しなかった。In the liquid crystal display device of this embodiment, the power for driving the liquid crystal panel is as small as 1 mW, and almost no flicker occurs at the time of polarity inversion.
【００３８】（比較例）実施の形態１の液晶表示装置か
ら極性反転時電圧補正部を取り除き、Ｖref1とＶref2の
電位が０Ｖと５Ｖの間を極性反転の度に切り替わる電圧
とした。その他は実施の形態と同じである。この液晶表
示装置は極性反転時のフリッカが酷く発生した。(Comparative Example) The polarity reversal voltage corrector was removed from the liquid crystal display device of the first embodiment, and the voltage between Vref1 and Vref2 was switched between 0 V and 5 V every time the polarity was reversed. Others are the same as the embodiment. In this liquid crystal display device, flicker during polarity reversal was severely generated.
【００３９】さらに、この比較例の極性反転を１垂直周
期ごとの１水平（Ｈ）反転とし、図１０に示す従来のＨ
・コモン反転駆動とした。この時、液晶パネルを駆動す
る電力は３００ｍＷと大きかった。Further, the polarity inversion of this comparative example is one horizontal (H) inversion every one vertical cycle, and the conventional H shown in FIG.
・ Common inversion drive. At this time, the power for driving the liquid crystal panel was as large as 300 mW.
【００４０】（実施の形態２）実施の形態１の液晶表示
装置において、走査線方向に隣接する画素の液晶に印加
される電圧を互いに逆極性にした。すなわち図８に示す
透過率平均法で駆動する。図９に、信号波形とコモン電
圧を示す。信号波形は偶数番目の信号線と奇数番目の信
号線とで互いに逆極性とした。コモン電圧は１Ｖに固定
している。この駆動によっても、隣接する捜査線上の画
素が同レベルの信号に対して等しい透過率を示すため、
極性反転時のフリッカが生じなかった。(Embodiment 2) In the liquid crystal display device of Embodiment 1, the voltages applied to the liquid crystals of the pixels adjacent in the scanning line direction have opposite polarities. That is, it is driven by the transmittance average method shown in FIG. FIG. 9 shows a signal waveform and a common voltage. The signal waveforms of the even-numbered signal lines and the odd-numbered signal lines have opposite polarities. The common voltage is fixed at 1V. Even with this drive, since the pixels on the adjacent search lines show the same transmittance for the same level of signal,
No flicker occurred during polarity reversal.
【００４１】なお、本発明は各種液晶モード（ＴＮ、Ｉ
ＰＳモードなど）、各種液晶駆動方式（アナログサンプ
ルホールド型アクティブマトリクス方式、ＭＩＭ型アク
ティブマトリクス方式、単純マトリクス方式）など極性
反転が必要な液晶液晶表示装置にも適用が可能で、本実
施の形態と同様の効果があることはいうまでもない。In the present invention, various liquid crystal modes (TN, I
It can be applied to liquid crystal liquid crystal display devices requiring polarity reversal, such as a liquid crystal driving method (PS mode, etc.), various liquid crystal driving methods (analog sample hold type active matrix method, MIM type active matrix method, simple matrix method). Needless to say, there is a similar effect.
【００４２】[0042]
【発明の効果】以上、詳細な説明したように、本発明に
よればフリッカが改善された低消費電力の液晶表示装置
を提供することができ、しかもこれを簡易な手段の付加
で実現することができる。As described in detail above, according to the present invention, it is possible to provide a low power consumption liquid crystal display device with improved flicker, and to realize this by adding simple means. Can be.
【図１】（ａ）は本発明の一実施の形態の回路配置を示
す図、（ｂ）はコモン電極駆動回路の回路図、1A is a diagram showing a circuit arrangement according to an embodiment of the present invention, FIG. 1B is a circuit diagram of a common electrode driving circuit,
【図２】（ａ）は本発明の一実施の形態の極性反転時電
圧補正部の構成を示すブロック図、（ｂ）は（ａ）の補
正部の電圧波形図、2A is a block diagram illustrating a configuration of a polarity inversion voltage correction unit according to an embodiment of the present invention, FIG. 2B is a voltage waveform diagram of the correction unit in FIG.
【図３】本発明の一実施の形態の電圧波形図、FIG. 3 is a voltage waveform diagram according to one embodiment of the present invention;
【図４】本発明の一実施の形態の電圧波形図、FIG. 4 is a voltage waveform diagram according to one embodiment of the present invention;
【図５】本発明に係る液晶表示パネルの要部断面略図、FIG. 5 is a schematic sectional view of a main part of a liquid crystal display panel according to the present invention;
【図６】液晶表示パネルの一画素の等価回路図、FIG. 6 is an equivalent circuit diagram of one pixel of a liquid crystal display panel,
【図７】透過率と印加電圧の関係を示す曲線図、FIG. 7 is a curve diagram showing the relationship between transmittance and applied voltage;
【図８】（ａ）、（ｂ）は表示画面上の画素の極性反転
を説明する平面略図、FIGS. 8A and 8B are schematic plan views illustrating polarity inversion of pixels on a display screen;
【図９】本発明の他の実施の形態の電圧波形図、FIG. 9 is a voltage waveform diagram according to another embodiment of the present invention;
【図１０】従来装置の電圧波形図。FIG. 10 is a voltage waveform diagram of the conventional device.
１： 液晶表示パネル ２： 画素 ３： 画素電極 ５： 信号線 ６： 走査線 ８： コモン電極 １０、１１：配向膜 １２：液晶層 ２０：信号線ドライバ部 ３０：走査線ドライバ部 ４０：コモン電極駆動回路部 ５０：極性反転時電圧補正部 1: liquid crystal display panel 2: pixel 3: pixel electrode 5: signal line 6: scanning line 8: common electrode 10, 11: alignment film 12: liquid crystal layer 20: signal line driver section 30: scanning line driver section 40: common electrode Drive circuit unit 50: Voltage correction unit at polarity inversion
───────────────────────────────────────────────────── フロントページの続き (72)発明者 鷺 成一 神奈川県横浜市磯子区新杉田町８番地 株 式会社東芝横浜事業所内 (72)発明者 佐藤 清一 神奈川県川崎市川崎区日進町７番地１ 東 芝電子エンジニアリング株式会社内 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiichi Sagi 8, Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Toshiba Yokohama Office (72) Inventor Seiichi Sato 7-1, Nisshincho, Kawasaki-ku, Kawasaki-shi, Kanagawa-ken Toshiba Electronics Engineering Corporation
Claims (4)
液晶層を挟み込む様に配置された電極を含む複数の画素
を有する液晶表示パネルと、前記信号線と走査線に前記
画素の駆動電圧を印加する電圧印加手段と、１フレーム
期間以上の時間単位で前記画素に印加する駆動電圧の極
性を反転する極性反転手段とを具備する液晶表示装置に
おいて、前記各画素を第１の複数フレーム期間にわたっ
て同一極性の電圧で駆動する手段と、次の第２の複数フ
レーム期間では前記各画素電圧を極性反転して駆動する
手段と、前記第１および第２の複数フレーム期間中に１
または複数のフレーム期間毎に、印加される駆動電圧を
徐々に遷移、変化させる手段とを具備することを特徴と
する液晶表示装置。A plurality of signal lines and a plurality of scanning lines;
A liquid crystal display panel having a plurality of pixels including electrodes arranged to sandwich a liquid crystal layer, voltage applying means for applying a driving voltage of the pixels to the signal lines and the scanning lines, and a time unit of one frame period or more. A liquid crystal display device comprising: a polarity inverting unit for inverting the polarity of a driving voltage applied to the pixel; a unit for driving each of the pixels with a voltage having the same polarity over a first plurality of frame periods; Means for inverting the polarity of each of the pixel voltages during a plurality of frame periods; and driving the pixel voltages during the first and second plurality of frame periods.
A liquid crystal display device comprising: means for gradually changing and changing the applied driving voltage for each of a plurality of frame periods.
した残留電圧を次の複数フレーム期間に印加され前記駆
動電圧と異なる値に遷移された駆動電圧により相殺し
て、前記液晶層にかかる電圧がどのフレーム期間におい
てもほぼ同一になる様にしたことを特徴とする請求項１
に記載の液晶表示装置。2. A voltage applied to the liquid crystal layer by offsetting a residual voltage generated in a liquid crystal layer of a pixel in a plurality of frame periods by a drive voltage applied in the next plurality of frame periods and changed to a value different from the drive voltage. Are set to be substantially the same in any frame period.
3. The liquid crystal display device according to 1.
晶層に印加される電圧が大きい程大きくすることを特徴
とする請求項１に記載の液晶表示装置。3. The liquid crystal display device according to claim 1, wherein the amount of voltage transition when the polarity is inverted is increased as the voltage applied to the liquid crystal layer is increased.
は互いに逆極性であることを特徴とする請求項１または
請求項３に記載の液晶表示装置。4. The liquid crystal display device according to claim 1, wherein voltages applied to liquid crystal layers of adjacent pixels have opposite polarities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17438997A JPH1124634A (en) | 1997-06-30 | 1997-06-30 | Liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17438997A JPH1124634A (en) | 1997-06-30 | 1997-06-30 | Liquid crystal display |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1124634A true JPH1124634A (en) | 1999-01-29 |
Family
ID=15977759
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17438997A Pending JPH1124634A (en) | 1997-06-30 | 1997-06-30 | Liquid crystal display |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1124634A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002304161A (en) * | 2001-01-30 | 2002-10-18 | Semiconductor Energy Lab Co Ltd | Liquid crystal display |
| WO2005033785A1 (en) * | 2003-10-02 | 2005-04-14 | Sanyo Electric Co.,Ltd. | Liquid crystal display unit and driving method therefor and drive device for liquid crystal display panel |
| JP2009282489A (en) * | 2008-05-19 | 2009-12-03 | Lg Display Co Ltd | Liquid crystal display for enhancing display quality, and driving method therefor |
| JP2010044351A (en) * | 2008-08-08 | 2010-02-25 | Lg Display Co Ltd | Liquid crystal display and its driving method |
| US9922605B2 (en) | 2013-12-31 | 2018-03-20 | Samsung Display Co., Ltd. | Display device and driving method thereof |
| US10319320B2 (en) | 2015-07-13 | 2019-06-11 | Samsung Display Co., Ltd. | Display device and method of driving the same |
-
1997
- 1997-06-30 JP JP17438997A patent/JPH1124634A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002304161A (en) * | 2001-01-30 | 2002-10-18 | Semiconductor Energy Lab Co Ltd | Liquid crystal display |
| WO2005033785A1 (en) * | 2003-10-02 | 2005-04-14 | Sanyo Electric Co.,Ltd. | Liquid crystal display unit and driving method therefor and drive device for liquid crystal display panel |
| KR100794105B1 (en) * | 2003-10-02 | 2008-01-10 | 산요덴키가부시키가이샤 | Liquid crystal display unit, driving method therefor, and drive device for liquid crystal display panel |
| JP2009282489A (en) * | 2008-05-19 | 2009-12-03 | Lg Display Co Ltd | Liquid crystal display for enhancing display quality, and driving method therefor |
| JP2010044351A (en) * | 2008-08-08 | 2010-02-25 | Lg Display Co Ltd | Liquid crystal display and its driving method |
| KR101330353B1 (en) * | 2008-08-08 | 2013-11-20 | 엘지디스플레이 주식회사 | Liquid Crystal Display and Driving Method thereof |
| US9922605B2 (en) | 2013-12-31 | 2018-03-20 | Samsung Display Co., Ltd. | Display device and driving method thereof |
| US10319320B2 (en) | 2015-07-13 | 2019-06-11 | Samsung Display Co., Ltd. | Display device and method of driving the same |
| US10540935B2 (en) | 2015-07-13 | 2020-01-21 | Samsung Display Co., Ltd. | Display device and method of driving the same |
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