JPH09230306A - Liquid crystal display device - Google Patents

Liquid crystal display device

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JPH09230306A
JPH09230306A JP4132396A JP4132396A JPH09230306A JP H09230306 A JPH09230306 A JP H09230306A JP 4132396 A JP4132396 A JP 4132396A JP 4132396 A JP4132396 A JP 4132396A JP H09230306 A JPH09230306 A JP H09230306A
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voltage
signal
circuit
liquid crystal
scanning
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JP4132396A
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Akinori Matsushita
明紀 松下
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Sanyo Electric Co Ltd
Tottori Sanyo Electric Co Ltd
三洋電機株式会社
鳥取三洋電機株式会社
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Abstract

PROBLEM TO BE SOLVED: To easily adjust display density and temp. compensation in the so- called simple matrix liquid crystal display device. SOLUTION: Any one of positive/negative selection voltages is selected and used as a scan voltage, and a signal voltage in the vicinity of an intermediate value between the positive selection voltage and the negative selection voltage is used selectively as the signal voltage according to an image signal, and at this time, a signal circuit 33 supplies the signal voltage depending on a peripheral temp. Further, a power source circuit 44 supplying the voltage of a prescribed bias value to a scan circuit 22 and the signal circuit 33 is constituted so that the voltage of the bias value is obtained by resistance division as the selection voltage, and a temp. dependent resistance element is used as the resistance for obtaining the signal voltage among the resistance division. Thus, the density is temp. compensated by voltage adjustment and bias ratio adjustment.

Description

【発明の詳細な説明】 DETAILED DESCRIPTION OF THE INVENTION

【0001】 [0001]

【発明の属する技術分野】本発明はいわゆる単純マトリクス駆動に好適な液晶表示装置に関する。 The present invention relates to relates to a liquid crystal display device suitable for a so-called simple matrix drive.

【0002】 [0002]

【従来の技術】従来より、互いに直交する電極群を有する液晶セルの駆動、いわゆる単純マトリクス駆動に於ては、一方の電極群の電極に順次電圧レベルの高い電圧を与え、その電圧レベルの高い電圧を印加しているときに他方の電極群に画信号に応じた電圧を与える線順次走査を電圧平均化法に従ったバイアス電圧で行っており、さらに液晶に直流を印加しないために特公昭57−577 Conventionally, Te is at the liquid crystal drive cell, a so-called simple matrix drive with an electrode group which are perpendicular to each other, giving successively higher voltage level voltage to the electrode of one electrode group, higher voltage level is carried out at a bias voltage in accordance with line-sequential scanning provide a voltage corresponding to the image signal to the other electrode group in the voltage averaging method, when the application of the voltage, JP-B to further not applied direct current to the liquid crystal 57-577
18号公報に示されるように極性反転をさせていた。 It was allowed to polarity inversion, as shown in 18 JP.

【0003】このような駆動において、液晶層には、走査時には所定の電圧値の電圧が、また非走査時にも信号電圧による一定の電圧がそれぞれ印加され、それが交流化されるものの、選択画素においては所定の実効値の電圧が印加され、非選択画素においても幾らかの実効値の電圧が印加されることとなった。 In such a drive, the liquid crystal layer, the voltage of the predetermined voltage value at the time of scanning, also a constant voltage by even signal voltage during the non-scanning are applied respectively, although it is AC, the selected pixel voltage of a predetermined effective value is applied in the voltage of some effective value even in the non-selected pixel was to be applied.

【0004】 [0004]

【発明が解決しようとする課題】ところがこのように非選択画素にも電圧が印加されることによって、選択時の実効値と非選択時の実効値の間で表示濃度(光透過率) By applying a voltage to hand the non-selected pixels Thus [0005], display density between the effective value and the non-selected when the effective value of the time of selection (light transmittance)
が大きく変化する必要があり、一方液晶セルは周知の如く駆動電圧や周囲温度によってこの濃度の変化点が変化するので、これらを使用環境によって調整する必要があった。 It is must be greatly changed, whereas since the liquid crystal cell change point of the density changes by a well-known as a driving voltage and ambient temperature, it is necessary to adjust these use environments. そしてこのような調整は一般的には、液晶セルの電源回路に供給する電圧を使用者が可変抵抗等を用いて見易い画面になる様に調整していたが、煩雑であった。 And such adjustment Generally, the user of the voltage supplied to the power supply circuit of a liquid crystal cell was adjusted so as to be easy to see the screen using a variable resistor or the like, is troublesome.
そこで走査回路や信号回路等に所定のバイアス値の電圧を供給する電源回路を抵抗分割によって構成し、その抵抗分割回路にサーミスターやポジスタを組合せて周囲温度に対する電圧補償を行うことが提案されたものの、温度依存抵抗素子の温度特性が所望の調整に対して逆向きであったり、温度依存抵抗素子の温度に対する変化率が液晶セルの温度特性の変化率と一致しないため、実用的でなかった。 The power supply circuit for supplying Therefore voltage of a predetermined bias value to the scan and signal circuits such as constituted by resistance division, it has been proposed to carry out a voltage compensation for ambient temperature by combining the thermistor or posistor to the resistive divider although, the temperature characteristics of the temperature-dependent resistance element or a reverse direction to the desired adjustment, since the change rate with respect to temperature of the temperature-dependent resistance element does not match the rate of change of the temperature characteristics of the liquid crystal cell was not practical .

【0005】一方単純マトリクスの表示装置は、交流化信号の切替え時に液晶に起因する大きな容量性負荷電流が流れ、消費電力が多くなり、また大表示容量化に伴って高速高耐圧集積回路が必要になってきた。 On the other hand the display device of the simple matrix will flow a large capacitive load current due to the liquid crystal at the time of switching of the alternating signal, the power consumption is increased, also requires high-speed and high-voltage integrated circuits with the large display capacity It has become. しかし集積回路にとって、高速化と高耐圧化は相反する仕様であり、実現が困難となっていた。 But for integrated circuits, high-speed and high breakdown voltage is a contradictory specification, implementation has been difficult. そこで走査信号を大きい正負の電圧とし、信号電圧を正の選択電圧と負の選択電圧の中間値近傍の電圧とすることを検討し一定の効果を得たが、上述した温度による動作点の変動に対しては従来の液晶セルの電源回路に供給する電圧を使用者が可変抵抗等を用いて見易い画面になる様に調整する方法を用いるに過ぎなかった。 So the positive and negative voltages greater scanning signal and to obtain a certain effect to consider the signal voltage and the positive selection voltage and the intermediate value voltage near the negative selection voltage, variation of the operating point due to temperature described above against was only use a method of adjustment as a user of the voltage supplied to the power supply circuit of a conventional liquid crystal cell is easily viewable screen using a variable resistor or the like.

【0006】 [0006]

【課題を解決するための手段】本発明は、上述した液晶セルの濃度の変化点が、印加電圧の大きさや温度のみでなくバイアス比にも依存することを考慮して成されたものである。 Means for Solving the Problems The present invention, change point of concentration of a liquid crystal cell described above, it has been made in consideration of the fact that it depends on the bias ratio not only the size and temperature of the applied voltage .

【0007】即ち本発明は、いわゆる単純マトリクスの液晶セルの駆動において、走査電圧に正負の選択電圧のいずれかを選択し用い、信号電圧に正の選択電圧と負の選択電圧の中間値近傍の信号電圧を画信号に応じて選択的に用い、この時信号回路が周囲温度に依存させて信号電圧を供給するように構成したものであり、あるいはまた、走査回路と信号回路に所定のバイアス値の電圧を供給する電源回路を選択電圧を抵抗分割によってバイアス値の電圧を得るように構成し、その抵抗分割のうち信号電圧を得るための抵抗として、温度の上昇に伴ってバイアス比が小さくなるように接続された温度依存抵抗素子を用いるものである。 [0007] The present invention, in the driving liquid crystal cell of so-called simple matrix, select one of the positive and negative selection voltages used in the scanning voltage, the signal voltage of the intermediate value near the positive selection voltage and a negative selection voltage selectively used according to the signal voltage to the image signal, is intended the time signal circuit is configured to provide a signal voltage by depending on the ambient temperature, or alternatively, a predetermined bias value to the scanning circuit and the signal circuit the power supply circuit for supplying a voltage selection voltage configured to obtain a voltage of the bias value by the resistance division, as a resistor for obtaining a signal voltage of the resistance division, the bias ratio decreases with increasing temperature it is to use a connected temperature-dependent resistance element so.

【0008】 [0008]

【発明の実施の形態】まず本発明の原理について、例えば、フレーム毎に極性反転する交流化信号Mを与えることで交流駆動する場合、最初のフレームの走査の時間に走査電極にV0を与え、他方の信号電極には表示したいとき(選択画素)はV1を与え、そして次のフレームにおいて、走査電極にV1を与え、信号電極にはV0を与えるような従来の駆動方式を例に、説明する。 The principle of the first present invention PREFERRED EMBODIMENTS given, for example, if the AC driving by giving alternating signal M whose polarity is inverted every frame, the V0 to time the scanning electrodes of the scanning of the first frame, when you want to view the other signal electrodes (selection pixels) gives the V1, and in the next frame, gives V1 to the scanning electrode, the signal electrodes as an example of a conventional driving method which gives the V0, explained .

【0009】図1において、1は、いわゆる単純マトリクス駆動に用いる、互いに直交する電極群を有する液晶セルで、2は、液晶セル1の一方の電極群の所定の電極に選択電圧を走査電圧として与える走査回路である。 [0009] In FIG. 1, 1 is used in a so-called simple matrix driving, a liquid crystal cell having an electrode group which are perpendicular to each other, 2, to a predetermined electrode of one electrode group of the liquid crystal cell 1 the selection voltage as the scan voltage it is a scanning circuit to give. 3
は、液晶セル1の他方の電極群に信号電圧を画信号に応じて与える信号回路で、4は、走査回路2と信号回路3 A signal voltage to the other electrode group of the liquid crystal cell 1 in the signal circuit to provide in response to the image signal, is 4, the scanning circuit 2 and the signal circuit 3
に所定のバイアス値の電圧と各回路の駆動電圧を供給する電源回路である。 To a power supply circuit for supplying a driving voltage of the voltage and the circuit of a predetermined bias value. 電源回路4は例えばパーソナルコンピュータなど表示装置を組み込む装置から30ボルトの電圧を受け取り、3端子電源回路46によるロジック電圧5ボルトと、液晶セル駆動バイアス電圧、例えば電圧平均化法に従った、走査・信号選択電圧Vと、走査非選択電圧Vcと信号非選択電圧Vsを5つの抵抗R、R0 Power supply circuit 4 receives the voltage of 30 volts from the device incorporating the display device such as a personal computer, 3 a logic voltage 5 volts by the terminal power supply circuit 46, a liquid crystal cell driving bias voltage, for example, according to the voltage averaging method, scanning and and signal selection voltage V, 5 single resistor scanning non-selection voltage Vc and signal non-selection voltage Vs R, R0
による抵抗分割回路で形成し、これをバッファ5を介して出力している。 Formed by resistance division circuit by which the outputs via a buffer 5.

【0010】これらの抵抗分割回路は、いわゆる適正バイアス比という理論があり、これは走査線数Nに対してN 1/2 +1で示されるバイアス比になる様に構成され、 [0010] These resistive divider circuit, there is the theory that a so-called proper bias ratio, which is configured so as to be bias ratio represented by N 1/2 +1 to the scanning line number N,
例えばN=121のときR=1とR0=8との比率になるように抵抗値が選ばれるとき、もっともコントラストがよいとされている。 For example, when the resistance value is chosen so that the ratio of R = 1 and R0 = 8 when N = 121, are the most contrast is good. 従来はこのバイアス回路に供給される電源路、若しくは選択電圧間(V−V)にサーミスタなどの温度依存抵抗素子を挿入するか、若しくは抵抗分割回路のどれか(例えばR0)に替えてサーミスタを挿入することで、上述した適正バイアス比を保ったまま印加電圧を供給しようとしていたため、実際の周囲温度に対して濃度の変化点の変化に対応した所定の電圧を供給設定することが困難であった。 Conventionally supply passage that is supplied to the bias circuit, or to insert a temperature-dependent resistance element such as a thermistor between the selection voltage (V-V), or a thermistor instead of any (e.g. R0) of the resistive divider circuit by inserting, because of trying to supply remains applied voltage maintaining proper bias ratio as described above, it is difficult to supply sets the actual predetermined voltage corresponding to a change in the concentration of the changing point relative to ambient temperature there were.

【0011】本発明は、このようないわゆる適性バイアス比が現実の液晶セルでは少しずれていることを考慮し、むしろ同じ走査線数の液晶セルであっても異なるバイアス比の電圧を印加すると表示濃度やコントラストを最良にする動作点(濃度の変化点に相当)の電圧が異なることを考慮してなされたものである。 [0011] The present invention relates to a display with the so-called suitability bias ratio considering that deviates slightly in the real liquid crystal cell, but rather a voltage of the same number of scanning lines are different bias ratio a liquid crystal cell in which the voltage of the operating point to optimize the density and contrast (corresponding to a change point of concentration) was made in view of the different. そして図1の例では、バイアス比を定める抵抗のうち、非選択電圧を定める抵抗Rの直列接続された2つずつに対して温度の上昇に対して抵抗値が下がるサーミスタRtを各々並列接続したものである。 And in the example of FIG. 1, of the resistors determining the bias ratio, and the thermistor Rt that resistance decreases with the series-connected two by two elevated temperatures for the resistor R defining a non-selection voltage to each parallel connection it is intended. これによって温度の上昇に伴ってバイアス比が小さくなり、濃度の変化点の電圧が高く供給され、見易い表示が提供できる。 This bias ratio decreases with increasing temperature, is supplied higher voltage levels change point, easy to see display can be provided.

【0012】図2は本発明実施例の液晶表示装置のブロック図で、11は互いに直交する電極群を有する液晶セルで、例えばスーパーツイストネマティック液晶表示器などの電界効果型液晶が利用できる。 [0012] Figure 2 is a block diagram of a liquid crystal display device of the present invention embodiment, 11 in the liquid crystal cell having an electrode group which are perpendicular to each other, for example, a field effect type liquid crystal is utilized, such as super twisted nematic liquid crystal display. これらの液晶セル11の電極は、いわゆる単純マトリクスを構成し、画素交点に能動素子を持たないものである。 Electrodes of the liquid crystal cell 11 constitutes a so-called simple matrix, in which no active element in a pixel intersections.

【0013】22は、その液晶セル11の一方の電極群に走査電圧を与える走査回路で、正負の電圧−VL、+ [0013] 22 is a scanning circuit for applying a scanning voltage to one electrode group of the liquid crystal cell 11, the positive and negative voltage -VL, +
VHと中間電圧Vmのいずれかを選択して所定の電極に供給するものであり、このうち−VL、+VHは選択電圧である。 Select one of the VH and the intermediate voltage Vm is intended to supply a given electrode, these -VL, + VH is selected voltage. 33は、液晶セル11の他方の電極群に画信号に応じた信号電圧を与える信号回路で、特には走査回路22の正の選択電圧+VHと負の選択電圧−VLの中間値近傍の2種類の信号電圧−Vb、+Vbを画信号に応じて選択的に電極に供給するものである。 33 is a signal circuit for supplying a signal voltage corresponding to the image signal to the other electrode group of the liquid crystal cell 11, in particular the positive selection voltage + VH and negative two intermediate values ​​near the selection voltage -VL scanning circuit 22 the signal voltage -Vb, and supplies the selectively electrodes in accordance with image signals + Vb. これらの電圧関係は図3に示すとおりで、室温より若干低い温度で適正バイアス比に近接したものとなる。 These voltage relationship is as shown in FIG. 3, it becomes close to a proper bias ratio at a temperature slightly lower than room temperature. 図3aは交流化信号Mと走査・駆動する電圧波形で、図3bは液晶に印加される電圧であり、いずれも横軸は時間である。 Figure 3a is a voltage waveform to scan-driving the switching signal M, Fig. 3b is a voltage applied to the liquid crystal, both the horizontal axis represents time. これらの図において走査電圧は一定の周期で正負いずれかの選択電圧が選択される様子を示しており、信号電圧は画信号と極性反転に伴って2つの値のうちどちらを選択されるのか変化するので、2つの信号電圧のいずれをも算盤の駒状に記載して表現している。 Scanning voltage in these figures shows a state in which either positive or negative selection voltage at a constant cycle is selected, whether the signal voltage is selected which of the two values ​​in accordance with the image signal and the polarity inversion change since is expressed set forth in abacus frame like any of the two signal voltages.

【0014】44は、走査回路22と信号回路33に所定のバイアス値の電圧を供給する電源回路で、少なくとも正負の選択電圧−VL、+VHと信号電圧−Vb、+ [0014] 44 is a power supply circuit for supplying a voltage of a predetermined bias value to the scanning circuit 22 and the signal circuit 33, at least the positive and negative selection voltage -VL, + VH and the signal voltage -Vb, +
Vbと中間電圧Vmとを出力し、より好ましくは、走査回路22や信号回路33、さらには信号授受回路66やバッファ45の駆動電圧Vic等をも供給する。 Outputs and Vb and an intermediate voltage Vm, more preferably, the scanning circuit 22 and the signal circuit 33, furthermore also supplies a driving voltage Vic and the like of the signal transfer circuit 66 and a buffer 45. この信号授受回路66は、信号回路33に供給される各種タイミング信号や画信号に応じた信号をバッファを介して伝送するもので、走査回路22の駆動伝達レベルが供給電源レベルと異なる場合レベルシフトを行ったり、初期化信号を付加して与えるものである。 The signal transfer circuit 66 is for transmitting a signal corresponding to various timing signals and image signals supplied to the signal circuit 33 via a buffer, if the level shift drive transmission level of the scanning circuit 22 is different from the power supply level the and go and gives added an initialization signal.

【0015】この電源回路44は、この表示装置が組み込まれるパーソナルコンピュータなどから供給される電源が、0−5ボルト電圧系である場合、そのまま走査回路22と信号回路33の駆動電圧Viとして用てもよいし、必要に応じて、電圧発生回路(DC/DCコンバータ)41により改めて0−5ボルト系の電圧を得てもよい。 [0015] The power supply circuit 44, Te use power the display device is supplied from a personal computer to be incorporated is, when a 0-5 volt system, it is as the driving voltage Vi of the scanning circuit 22 and the signal circuit 33 may, if necessary, may be obtained voltage again 0-5 volt by the voltage generation circuit (DC / DC converter) 41. 一方供給された電圧を電圧発生回路(DC/DCコンバータ)41に入力し、正負の選択電圧−VL、+V On the other hand the supply voltage input to the voltage generating circuit (DC / DC converter) 41, the positive and negative selection voltages -VL, + V
Hを生成させている。 And to generate H. ここに正負というのは、何かの絶対電位、例えばこの表示装置が組み込まれるパーソナルコンピュータの電源に対して規定された電位のことではなく、非走査時の走査電圧Vmに対する電位で表現している。 Here because the positive and negative absolute potential of something, for example, not that the defined potential to the power supply of the personal computer which this display device is incorporated, are expressed by the potential with respect to the scanning voltage Vm at the non-scanning . 選択電圧に基づいてこれを抵抗分割しバッファ4 Resistance division this based on the selected voltage buffer 4
5を介することによって信号電圧+Vb、−Vbと中間電圧Vmを得る。 5 to obtain a signal voltage + Vb, -Vb the intermediate voltage Vm by via. 但し、この抵抗分割は、図1の如く1 However, the resistance division, as in FIG. 1 1
本の直列接続された抵抗で全てのバイアス電圧を得てもよいが、複数の抵抗分割回路で得てもよい。 May be obtained for all of the bias voltage in series connected resistors of the book, it may be obtained by a plurality of resistive divider circuit. 図の例では全ての電圧を単一の抵抗分割回路で直接得るのではなく、中間電圧Vmは抵抗Rmによって得、信号電圧−V Rather than directly obtained by a single resistive divider circuit all the voltages in the example of FIG intermediate voltage Vm is obtained by the resistance Rm, the signal voltage -V
bは信号電圧+Vbの反転で得るなど間接的に得ている。 b is indirectly obtained, such as obtained by inversion of the signal voltage + Vb. このように信号電圧+Vbを中間電圧Vmに対して反転させて信号電圧−Vbを得ることによって、中間電圧Vmに対する信号電圧+Vbの変動分だけ信号電圧− By inverts obtain a signal voltage -Vb with respect to such a signal voltage + Vb of the intermediate voltage Vm, variation only signal voltage of the signal voltage + Vb with respect to the intermediate voltage Vm -
Vbに反映させることができるので、大変好ましい。 Since it is possible to be reflected in the Vb, very preferable. またこの結果、信号電圧の中心と選択電圧の中心が、いずれも中間電圧Vmとなるように設定され好ましい。 The result, the centers of the selection voltage of the signal voltage are both set to be the intermediate voltage Vm preferred.

【0016】この駆動により、走査回路22の集積回路の出力段は従来の略倍の耐電圧を必要とするが、走査線数に応じた低速処理であり、出力段で3つの電位のうち一つを選択するので交流化信号の切り替え時の大きな電流は発生せず、また従来見られがちだったクロストーク発生の基になる波形崩れもきわめて生じ難い。 [0016] With this drive, the output stage of the integrated circuit of the scanning circuit 22 requires a withstand voltage of a conventional substantially doubled, a slow processing in accordance with the number of scanning lines, one of the three potential at the output stage One large current during switching of the AC signal so that selection does not occur, and also hard to very resulting wave form collapse the underlying crosstalk generation was seen often conventionally. 一方信号回路33は上述の例でわずか5ボルト以内という低電圧しか扱わず、高速駆動に適しているばかりか、集積回路の面積も小さくできるので、ミリメートル単位で液晶周辺の幅(通称額縁)を短くするのに凌ぎを削っていることに対しても幅の狭い駆動素子が利用・配置できるので好ましい。 Meanwhile the signal circuit 33 is not only handles low voltages as within only 5 volts in the above example, not only is suitable for high-speed driving, since the area of ​​the integrated circuit can be reduced, the width of the liquid crystal near in millimeters (the called frame) preferred because the narrow drive element can be used, also disposed width against which competing for short.

【0017】かかる構成で特徴的なことは、信号回路3 The characteristic feature in such a configuration, the signal circuit 3
3は、信号電圧±Vbを周囲温度に依存させて供給することであり、そのために電源回路44は、バイアス電圧のうち信号電圧を得るための抵抗を、温度の上昇に伴ってバイアス比が小さくなるように接続された温度依存抵抗素子で構成したものである。 3 is to supply by dependent signal voltage ± Vb to ambient temperature, the power supply circuit 44 to do so, a resistor for obtaining a signal voltage of the bias voltage, bias ratio with increasing temperature is small which is constituted by connected temperature-dependent resistance element so. これを単純マトリクス駆動における液晶セルの特性を、270度液晶分子捩、走査線数240本のスーパーツイストネマティック液晶セルを例に説明する。 The characteristics of the liquid crystal cell in the simple matrix driving this, 270 ° twisted liquid crystal molecules, a super twisted nematic liquid crystal cell of scanning lines 240 will be described as an example. 液晶セルは、電圧の印加に伴って多少のヒステリシスを持つ輝度変化を示すが、図4(縦軸は光透過率T、横軸は駆動電圧V)に示すごとく周囲温度(LOW,ROOM,HIGH)が高くなると濃度の変化点が低くなり、従来はこれに追従するような電圧制御を行ってきた。 The liquid crystal cell shows a change in luminance with some hysteresis in accordance with the application of a voltage, FIG. 4 (vertical axis is the light transmittance T, the horizontal axis represents the driving voltage V) the ambient temperature as shown in (LOW, ROOM, HIGH ) becomes higher the lower the change point of concentration, conventionally it has been performed a voltage control so as to follow this. 一方、一定の周囲温度下でバイアス比を変化させると、図5に示すように、1/14バイアス駆動では濃度とコントラストを適正にする電圧は低く、 On the other hand, when changing the bias ratio under constant ambient temperature, as shown in FIG. 5, 1/14 in the bias driving voltage to proper density and contrast low,
1/18バイアス駆動では電圧が高くなる。 1/18 the voltage becomes higher in bias driving. さらに汎用されている特性の安定したサーミスタは温度の上昇に伴って抵抗値が低下する。 More stable thermistor properties are widely resistance value with increasing temperature decreases. そこで本発明のこの実施例では、信号電圧±Vbを生成させるために選択電圧+VH In this embodiment of the present invention is therefore, selected to generate a signal voltage ± Vb voltage + VH
と中間電圧Vmの間に設けられた抵抗分割回路の抵抗R Resistance R of the resistor division circuit provided between the intermediate voltage Vm
a、Rbのうち、信号電圧+Vbを得るための抵抗Rb a, of Rb, resistance Rb for obtaining a signal voltage + Vb
を温度の上昇に伴ってバイアス比が小さくなるようにサーミスタと固定抵抗とを直列(または並列)接続することで構成した。 Series and a fixed resistor and a thermistor as a bias ratio decreases with increasing temperature (or parallel) was constructed by connecting.

【0018】通常室温(+25度C)において、選択電圧+VH、−VLや信号電圧±Vbの大きさは、電圧平均化法に準じて求められ、例えば1/240デューティの駆動の場合最適バイアス値は1:16.5であり、中間電圧Vmの電位が供給電圧とフローティングされている場合には、選択電圧30ボルトに対して、供給電源0 [0018] In the normal room temperature (+25 ° C), the size of the selection voltage + VH, -VL or signal voltage ± Vb is sought in accordance with the voltage averaging method, for example, 1/240 if the optimum bias value of the duty of the drive was 1: 16.5, when the potential of the intermediate voltage Vm is supplied voltage and floating, with respect to the selection voltage 30 volts, power supply 0
ボルトレベルに対する信号電圧は略4.3ボルトと0. Signal voltage for the volt level is substantially 4.3 volts and 0.
7ボルトである。 It is 7 volts. 中間電圧VmとGNDレベルを一致させた方が好ましい場合、選択電圧+VH、−VLは±3 If better to match the intermediate voltage Vm and GND level is preferred, selection voltage + VH, -VL is ± 3
0ボルト、信号電圧±Vbは±1.8ボルトである。 0 volt, the signal voltage ± Vb is ± 1.8 volts. 本発明においては室温より低い場合を基準とし、Vm=G With respect to the lower than room temperature in the present invention, Vm = G
NDのとき、例えば+15度Cで選択電圧±28ボルト、信号電圧±1.7ボルトとし、−2〜42度Cの範囲で見易い濃度とコントラストの表示を得ることができた。 When ND, for example, the selection voltage ± 28 volts at +15 ° C, and the signal voltage ± 1.7 volts, it was possible to obtain a display of the legible density and contrast in the range of -2~42 ° C.

【0019】 [0019]

【発明の効果】本発明は上述のように、液晶セル毎のしかも使用環境に依存した濃度調整を煩雑に行う必要がなく、しかも走査回路は正負の選択電圧を走査電圧として用い、画信号に応じて選択電圧の中間値近傍の2種類の信号電圧を用いるので、画信号が著しく増加しても信号回路は低電圧で負担は少なく高速処理できる。 According to the present invention as described above, moreover use environmentally troublesome is not necessary to perform a density adjustment dependent of each liquid crystal cell, yet the scanning circuit using positive and negative selection voltage as the scanning voltage, the image signal since depending on using two kinds of signal voltage of the intermediate value near the selection voltage, the signal circuit also significantly increased image signals burden at a low voltage can be reduced speed processing. 従って温度変化に敏感なスーパーツイストネマティック液晶セルなどであっても、少なくとも使用者が日常機器に向かう室温状態では、表示を見易い状態を保って使用することができた。 Accordingly be an sensitive super twisted nematic liquid crystal cell to a temperature change, the room temperature state of at least the user toward the everyday devices, it could be used while maintaining the easy-to-see state display.

【図面の簡単な説明】 BRIEF DESCRIPTION OF THE DRAWINGS

【図1】液晶表示装置のブロック図である。 1 is a block diagram of a liquid crystal display device.

【図2】本発明実施例の液晶表示装置のブロック図である。 2 is a block diagram of a liquid crystal display device of the present invention embodiment.

【図3】aは交流化信号及び走査回路と信号回路の出力電圧の駆動波形図で、bは液晶に印加される電圧の駆動波形図である。 [3] a is a driving waveform diagram of the output voltage of the alternating signal and the scanning circuit and the signal circuit, b is a driving waveform diagram of a voltage applied to the liquid crystal.

【図4】液晶セルの温度に関する特性図である。 4 is a characteristic diagram relating to the temperature of the liquid crystal cell.

【図5】液晶セルのバイアス比に関する特性図である。 5 is a characteristic diagram for bias ratio of the liquid crystal cell.

【符号の説明】 DESCRIPTION OF SYMBOLS

11 液晶セル 22 走査回路 33 信号回路 44 電源回路 11 liquid crystal cell 22 scanning circuit 33 a signal circuit 44 power supply circuit

Claims (2)

    【特許請求の範囲】 [The claims]
  1. 【請求項1】 互いに直交する電極群を有する液晶セルと、該液晶セルの一方の電極群の所定の電極に正負の選択電圧のいずれかを選択して走査電圧として供給する走査回路と、前記液晶セルの他方の電極群に前記走査回路の正の選択電圧と負の選択電圧の中間値近傍の信号電圧を画信号に応じて選択的に与える信号回路と、前記走査回路と前記信号回路に所定の値の電圧を供給する電源回路とを具備した液晶表示装置において、前記信号回路は、前記信号電圧を周囲温度に依存させて供給することを特徴とする液晶表示装置。 A liquid crystal cell having a 1. A group of electrodes orthogonal to each other, a scanning circuit for supplying a scanning voltage by selecting one of the one of the positive and negative selection voltage to a predetermined electrode of the electrode group of the liquid crystal cell, wherein the other positive selection voltage and the signal circuit for selectively providing according a negative intermediate value signal voltage near the selected voltage to the image signal of the scanning circuit to electrodes of the liquid crystal cell, the signal circuit and the scanning circuit in the liquid crystal display device having a power supply circuit for supplying a voltage of a predetermined value, the signal circuit, a liquid crystal display device and supplying the signal voltage by depending on the ambient temperature.
  2. 【請求項2】 互いに直交する電極群を有する液晶セルと、該液晶セルの一方の電極群の所定の電極に選択電圧を走査電圧として与える走査回路と、前記液晶セルの他方の電極群に信号電圧を画信号に応じて与える信号回路と、前記走査回路と前記信号回路に所定のバイアス値の電圧と各回路の駆動電圧を供給する電源回路とを具備した液晶表示装置において、前記電源回路は、前記選択電圧を抵抗分割によって前記バイアス値の電圧を得、そのうち前記信号電圧を得るための前記抵抗は温度の上昇に伴ってバイアス比が小さくなるように接続された温度依存抵抗素子であることを特徴とする液晶表示装置。 2. A liquid crystal cell having an electrode group which are perpendicular to each other, a scanning circuit for supplying a selection voltage to a predetermined electrode of one electrode group of the liquid crystal cell as a scanning voltage, the signal to the other electrode group of the liquid crystal cell a signal circuit for providing in response to the voltage on the image signal, the liquid crystal display device having a power supply circuit for supplying a driving voltage of the voltage and the circuit of a predetermined bias value to the scanning circuit the signal circuit, the power supply circuit give a voltage of the bias value the selection voltage by the resistance division, a temperature-dependent resistance element and the resistance connected to bias ratio with increasing temperature decreases to them obtaining the signal voltage the liquid crystal display device according to claim.
JP4132396A 1996-02-28 1996-02-28 Liquid crystal display device Granted JPH09230306A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4132396A JPH09230306A (en) 1996-02-28 1996-02-28 Liquid crystal display device

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Application Number Priority Date Filing Date Title
JP4132396A JPH09230306A (en) 1996-02-28 1996-02-28 Liquid crystal display device

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JPH09230306A true true JPH09230306A (en) 1997-09-05

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JP4132396A Granted JPH09230306A (en) 1996-02-28 1996-02-28 Liquid crystal display device

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100683519B1 (en) * 1999-12-23 2007-02-15 엘지.필립스 엘시디 주식회사 Circuit And Method for Compensating a Charging Characteristic of Liquid Crystal Panel

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100683519B1 (en) * 1999-12-23 2007-02-15 엘지.필립스 엘시디 주식회사 Circuit And Method for Compensating a Charging Characteristic of Liquid Crystal Panel
US7403186B2 (en) 1999-12-23 2008-07-22 Lg Display Co., Ltd. Charge characteristic compensating circuit for liquid crystal display panel

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