JPS59160124A - Driving method of liquid crystal for display - Google Patents

Abstract

PURPOSE:To make effective values roughly the same and to decrease a driving voltage by setting the min. voltage impressed between liquid crystal electrodes at a specific value in association with the driving voltage and duty. CONSTITUTION:The min. voltage to be impressed between liquid crystal electrodes in the stage of time-divided driving, as designated as x>1 is set at x/ (N1/2+1)XV0 where a driving voltage is designated as V0 and a duty as 1/N. If the duty 1/N is now made to 1/16, a biasing ratio is 1/5(=161/2+1) in the coventional voltage averaging method and the min. voltage of the impressed voltage is 1/5XV0. A coefft. alpha where a=N+1 is alpha=[(a<2>+N-1)/N]1/2/a 0.31. If the driving voltage V0=5.1V, an effective value Vs=not equal to XV0 1.6V. If X is larger than 1, for example, x=1.2, the biasing ratio is 1.2/5 and the coefft. alpha' is [(a<2>+ X(N-1)/N]1/2/a=0.33. Therefore, the driving voltage is 1.6/0.33 4.8V to obtain the same effective value, thus the driving voltage decreases by about 5%. While the biasing ratio of 1/5 is obtd. by using the resistors R1-R5 having the same resistance values in the prior art, the min. Voltage is obtainable from both terminals of the resistors R1, R2, R4, R5 by making R1, R2, R4, R5 to 1.2 times the conventional resistance value and making R3 to 0.2 time.

Description

【発明の詳細な説明】 〔発明の利用分野〕 本発明は高次時分割駆動を行なう液晶表示駆動方法に関
する。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a liquid crystal display driving method that performs high-order time division driving.

〔発明の背景〕[Background of the invention]

従来、液晶表示装置を時分割駆動する際には電圧平均化
法が用いられ、その印加電圧の最小値は、駆動電圧をＶ
ＯＩデユーティを輪とすると、ｖｏ／（ｖ’Ｎ＋ｉ）と
して設定されている。この駆動電圧は液晶材料等の要因
に依存しており、従来の方式では駆動電圧を低くするこ
とはできなかった。Conventionally, a voltage averaging method has been used when driving a liquid crystal display device in a time-division manner, and the minimum value of the applied voltage is
If the OI duty is a ring, it is set as vo/(v'N+i). This driving voltage depends on factors such as the liquid crystal material, and it has not been possible to lower the driving voltage with conventional methods.

〔発明の目的〕[Purpose of the invention]

本発明はこのような点に鑑みてなされたものであり、そ
の目的とするところは、実効値をほぼ同じにして駆動電
圧を低くすることがでさる液晶表示駆動方法を提供する
ことにある。The present invention has been made in view of these points, and an object of the present invention is to provide a liquid crystal display driving method that can lower the driving voltage while keeping the effective values substantially the same.

〔発明の概要〕[Summary of the invention]

本発明はこのような目的を達成するために、時分割駆動
する際の液晶電極間に印加される最小電圧を、ｘ　＞　
１としたときｘ／（ＶＫ＋１）ｘｖｏに設定したもので
ある。In order to achieve such an object, the present invention sets the minimum voltage applied between the liquid crystal electrodes during time-division driving to x >
When it is set to 1, it is set to x/(VK+1)xvo.

〔発明の実施例〕[Embodiments of the invention]

以下、本発明を実施例により説明する。 The present invention will be explained below using examples.

第１図は本発明に係る液晶表示駆動方法の一実施例にお
ける電圧波形図であり、（ａ）は走査線側の電極に印加
される電圧Ｖｙの波形、（ｂ）はセグメント側の電極に
印加される電圧ＶＸの波形、（ｃ）はマトリックス配列
された液晶セルの両電極間に印加される電圧（Ｖｙ　Ｖ
ｘ）の波形をそれぞれ示す。図において、ｔｏから１．
の間は点灯状態であり、ｔｌからｔ２の間は非点灯状態
であり、点灯時にはピーク値■ｏの交流電圧が液晶に印
加され、非点灯時にもピーク値Ｖｌの交流電圧が液晶に
印加される。FIG. 1 is a voltage waveform diagram in an embodiment of the liquid crystal display driving method according to the present invention, in which (a) is the waveform of the voltage Vy applied to the electrode on the scanning line side, and (b) is the waveform of the voltage Vy applied to the electrode on the segment side. The waveform of the applied voltage VX, (c) is the voltage applied between both electrodes of the matrix-arranged liquid crystal cell (Vy V
The waveforms of x) are shown respectively. In the figure, from to to 1.
The period between t1 and t2 is the lighting state, and the period from tl to t2 is the non-lighting state, and when the light is on, an AC voltage of the peak value ■o is applied to the liquid crystal, and even when the light is not lit, the AC voltage of the peak value Vl is applied to the liquid crystal. Ru.

いｉ、デユーティ１／／Ｎを１／１６　　とすると、従
来の電圧平均化法ではバイアス比は’１５　（＝ｖ’Ｍ
　＋１　）であり、印加電圧の最小値は１１５ＸＶｏと
なる。ここで８　”−”　Ｖ’Ｆｒ＋　１とすると係数
αは次式のようになる。If duty 1//N is 1/16, the bias ratio in the conventional voltage averaging method is '15 (=v'M
+1), and the minimum value of the applied voltage is 115XVo. Here, if 8"-"V'Fr+1 is assumed, the coefficient α becomes as shown in the following equation.

”１７１百ヌ覇 αニー　　　　　　　　　　ヰ０．３１　　・・・（１
）ここで、駆動電圧Ｖｏ　＝　５．１　（Ｖ）とすると
、実効値Ｖ８−αＸ　Ｖ　ｏ　’；　１．６　（Ｖ）　
（！：　ｆｘ　ル。``171 Hyakuha α Knee ヰ0.31...(1
) Here, if the driving voltage Vo = 5.1 (V), the effective value V8-αX Vo'; 1.6 (V)
(!: fx le.

本発明は従来のバイアス比ａに１より大きい係数Ｘを乗
じたものをバイアス比とする−ものであり、いま、ｘ　
＝　１．２とするとバイアス比は１．２１５　となる。The present invention uses the conventional bias ratio a multiplied by a coefficient X larger than 1 as the bias ratio, and now x
= 1.2, the bias ratio becomes 1.215.

この場合（１）式は次式のように変形される。In this case, equation (1) is transformed as shown below.

α′−→（ａ２＋Ｘ（Ｎ−１））／Ｎ　　　　・・・（
２）ここでａ　＝　ｖ’Ｆｒ＋１である。（２）式にｘ
＝１．２を代入すると、α’　：ｏ、ａａとなる。した
がって、同じ実効値を得るためには、従来は駆動電圧が
５．１（Ｖ）であったものが、”’１０．３３÷４．８
　（Ｖ）とな９．５％程度駆動電圧が低下する。なお、
第１図（Ｃ）におけるＶｌは１．２１５Ｘ　ＶＯ（Ｖ）
　　となる。α'-→(a2+X(N-1))/N...(
2) Here a = v'Fr+1. (2) In equation (2), x
By substituting =1.2, α' :o, aa. Therefore, in order to obtain the same effective value, the conventional drive voltage of 5.1 (V) must be changed to ``10.33÷4.8''.
(V), the driving voltage decreases by about 9.5%. In addition,
Vl in Figure 1 (C) is 1.215X VO (V)
becomes.

この実施例では、５（ｖ）の単電源で駆動することが可
能となり、態動電源を１台省略することができる。In this embodiment, it is possible to drive with a single 5(v) power supply, and one active power supply can be omitted.

液晶の電極間に印加される最小電圧は、駆動電圧を抵抗
の直列回路で分圧することにより得られる。The minimum voltage applied between the electrodes of the liquid crystal is obtained by dividing the driving voltage using a series circuit of resistors.

例えば　　−２第２図に示すよ うに、従来は抵抗Ｒ１〜Ｒ５に同じ抵抗値のものを用い
て稀のバイアス比を得ていたものが、本発明ではＲ１ｔ
　Ｒ２ｒ　Ｒ４、Ｒ５を従来の抵抗値の１．２倍とし、
Ｒ３を０．２倍として、抵抗Ｒ１＋　Ｒ２１Ｒ４゜Ｒ５
の両端から最小電圧を得ることができる。For example, as shown in -2 Figure 2, in the past, resistors R1 to R5 had the same resistance value to obtain a rare bias ratio, but in the present invention, R1t
R2r R4 and R5 are set to 1.2 times the conventional resistance value,
R3 is 0.2 times, resistance R1+ R21R4゜R5
The minimum voltage can be obtained from both ends of .

〔発明の効果〕〔Effect of the invention〕

以上説明したように、本発明に係る液晶表示駆動方法に
よると、従来の駆動方法により得られる実効値とほぼ同
じ実効値を得るだめには、駆動電圧を従来より低くする
ことが可能となシ、液晶の低駆動電圧化を達成できると
いう効果がある。As explained above, according to the liquid crystal display driving method according to the present invention, in order to obtain an effective value that is almost the same as the effective value obtained by the conventional driving method, it is possible to lower the driving voltage than before. This has the effect of achieving a lower driving voltage for the liquid crystal.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明に係る液晶表示Ｉり動力法の一実施例に
おける電圧波形図、第２図は分圧回路の一実施例の回路
図である。 Ｌ゛Δ１０ 第２図FIG. 1 is a voltage waveform diagram in an embodiment of the liquid crystal display I power method according to the present invention, and FIG. 2 is a circuit diagram of an embodiment of a voltage dividing circuit. L゛Δ10 Figure 2

Claims (1)

【特許請求の範囲】 駆動電圧をＶｏ　＋デユーティを１ｈとしたとき液晶電
極間に印加される最小電圧を、ｘ／（ＶＫ＋１　）ｘｖ
ｏ〔ただしｘ〉１〕としたことを特徴とする液晶表示駆
動・方法。[Claims] When the drive voltage is Vo + duty is 1h, the minimum voltage applied between the liquid crystal electrodes is x/(VK+1)xv
A liquid crystal display driving/method characterized in that: o [where x>1].