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JP2008083399A - Reference voltage circuit for liquid crystal display - Google Patents

Reference voltage circuit for liquid crystal display Download PDF

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JP2008083399A
JP2008083399A JP2006263375A JP2006263375A JP2008083399A JP 2008083399 A JP2008083399 A JP 2008083399A JP 2006263375 A JP2006263375 A JP 2006263375A JP 2006263375 A JP2006263375 A JP 2006263375A JP 2008083399 A JP2008083399 A JP 2008083399A
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reference voltage
gradation
common electrode
liquid crystal
digital
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Katsuhiko Kishida
克彦 岸田
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LG Display Co Ltd
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LG Philips LCD Co Ltd
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Priority to JP2006263375A priority Critical patent/JP2008083399A/en
Priority to KR1020060117554A priority patent/KR20080028730A/en
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3648—Control of matrices with row and column drivers using an active matrix
    • G09G3/3655—Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3696—Generation of voltages supplied to electrode drivers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/66—Digital/analogue converters
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/04—Maintaining the quality of display appearance
    • G09G2320/043—Preventing or counteracting the effects of ageing
    • G09G2320/046—Dealing with screen burn-in prevention or compensation of the effects thereof

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  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Liquid Crystal Display Device Control (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Liquid Crystal (AREA)

Abstract

【課題】共通電極電圧（Ｖｃｏｍ）の調整を不要にすることができ、ひいては製造工程を簡略化することができる液晶表示装置用基準電圧回路を得る。
【解決手段】液晶表示装置用基準電圧回路１００には、入力された階調データに基づいて２５６階調の正極及び負極の階調基準電圧を生成するデジタルアナログコンバータ１０と、基準電圧を分圧した共通電極電圧（Ｖｃｏｍ）を生成する共通電極電圧生成回路２０とを設けた。
【選択図】図１A reference voltage circuit for a liquid crystal display device that can eliminate the need for adjustment of a common electrode voltage (Vcom) and can simplify a manufacturing process is obtained.
A reference voltage circuit for a liquid crystal display device includes a digital-to-analog converter that generates positive and negative gradation reference voltages of 256 gradations based on input gradation data, and a reference voltage divided. And a common electrode voltage generation circuit 20 for generating the common electrode voltage (Vcom).
[Selection] Figure 1

Description

この発明は、階調基準電圧と共通電極電圧を生成する液晶表示装置用基準電圧回路に関するものである。   The present invention relates to a reference voltage circuit for a liquid crystal display device that generates a gradation reference voltage and a common electrode voltage.

従来の液晶表示装置用基準電圧回路について図５を参照しながら説明する。図５は、従来の液晶表示装置用基準電圧回路の構成を示す図である（例えば、特許文献１参照）。   A conventional reference voltage circuit for a liquid crystal display device will be described with reference to FIG. FIG. 5 is a diagram showing a configuration of a conventional reference voltage circuit for a liquid crystal display device (see, for example, Patent Document 1).

図５において、液晶表示装置用基準電圧回路３００は、第１、第２の基準電圧がそれぞれ印加される基準電圧端子３０１、３０２と、基準電圧端子３０１、３０２間に直列接続された複数の抵抗３０３とが設けられている。   In FIG. 5, a reference voltage circuit 300 for a liquid crystal display device includes reference voltage terminals 301 and 302 to which first and second reference voltages are applied, and a plurality of resistors connected in series between the reference voltage terminals 301 and 302, respectively. 303 is provided.

この図５に示す基準電圧回路３００は、基準電圧端子３０１、３０２にそれぞれ印加された第１、第２の基準電圧の差分電圧を複数の抵抗３０３により分圧して、例えば２５６階調の階調基準電圧（Ｖ２５５正極、Ｖ２５４正極、Ｖ２５３正極、〜、Ｖ１２８正極、Ｖ１２７正極、Ｖ１２６正極、〜、Ｖ２正極、Ｖ１正極、Ｖ０正極、Ｖ０負極、Ｖ１負極、Ｖ２負極、〜、Ｖ１２６負極、Ｖ１２７負極、Ｖ１２８負極、〜、Ｖ２５３負極、Ｖ２５４負極、Ｖ２５５負極）を生成するとともに、共通電極電圧（Ｖｃｏｍ）を生成する。なお、図５では、一部の階調基準電圧を省略している。   The reference voltage circuit 300 shown in FIG. 5 divides the differential voltage between the first and second reference voltages applied to the reference voltage terminals 301 and 302 by a plurality of resistors 303, for example, a gradation of 256 gradations. Reference voltage (V255 positive electrode, V254 positive electrode, V253 positive electrode, ~, V128 positive electrode, V127 positive electrode, V126 positive electrode, ~, V2 positive electrode, V1 positive electrode, V0 positive electrode, V0 negative electrode, V1 negative electrode, V2 negative electrode, ..., V126 negative electrode, V127 negative electrode , V128 negative electrode, V253 negative electrode, V254 negative electrode, V255 negative electrode) and a common electrode voltage (Vcom). In FIG. 5, some gradation reference voltages are omitted.

液晶表示装置は、交流駆動を行っている。この交流駆動電圧を液晶パネルの画素電極に加えている。画素電極と対を成す対向電極が液晶パネルの共通電極である。この共通電極には交流駆動による残留ＤＣが発生しないように、共通電極電圧（Ｖｃｏｍ）を印加する必要がある。従来は、階調基準電圧を固定とし、共通電極電圧（Ｖｃｏｍ）を製造工程で１台１台調整して製造ばらつきを無くしていた。   The liquid crystal display device performs AC driving. This AC drive voltage is applied to the pixel electrode of the liquid crystal panel. The counter electrode that forms a pair with the pixel electrode is a common electrode of the liquid crystal panel. It is necessary to apply a common electrode voltage (Vcom) to the common electrode so that residual DC due to AC driving does not occur. Conventionally, the gradation reference voltage is fixed and the common electrode voltage (Vcom) is adjusted one by one in the manufacturing process to eliminate manufacturing variations.

特開平７−３２５５５６号公報JP 7-325556 A

上述したような従来の液晶表示装置用基準電圧回路では、正極性と負極性のバランス調整を共通電極電圧（Ｖｃｏｍ）のみで行っていたため、表示階調によってはバランスが取れず残留ＤＣによる焼きつきを発生させているという問題点があった。   In the conventional reference voltage circuit for a liquid crystal display device as described above, the balance between positive polarity and negative polarity is adjusted only by the common electrode voltage (Vcom). There was a problem of generating.

この発明は、上述のような課題を解決するためになされたもので、その目的は、共通電極電圧（Ｖｃｏｍ）の調整を不要にすることができ、ひいては製造工程を簡略化することができる液晶表示装置用基準電圧回路を得るものである。   The present invention has been made to solve the above-described problems, and an object of the present invention is to make it unnecessary to adjust the common electrode voltage (Vcom), and thus to simplify the manufacturing process. A reference voltage circuit for a display device is obtained.

この発明に係る液晶表示装置用基準電圧回路は、入力された階調データに基づいて複数階調の階調基準電圧を生成するデジタル階調基準電圧生成回路と、共通電極電圧を生成する共通電極電圧生成回路とを設けたものである。   A reference voltage circuit for a liquid crystal display device according to the present invention includes a digital gradation reference voltage generation circuit that generates a plurality of gradation reference voltages based on input gradation data, and a common electrode that generates a common electrode voltage And a voltage generation circuit.

この発明に係る液晶表示装置用基準電圧回路は、共通電極電圧の調整を不要にすることができ、ひいては製造工程を簡略化することができるという効果を奏する。   The reference voltage circuit for a liquid crystal display device according to the present invention can eliminate the need for adjustment of the common electrode voltage, and thus has the effect of simplifying the manufacturing process.

実施の形態１．
この発明の実施の形態１に係る液晶表示装置用基準電圧回路について図１から図４までを参照しながら説明する。図１は、この発明の実施の形態１に係る液晶表示装置用基準電圧回路の構成を示す図である。 Embodiment 1 FIG.
A reference voltage circuit for a liquid crystal display device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a diagram showing a configuration of a reference voltage circuit for a liquid crystal display device according to Embodiment 1 of the present invention.

図１において、この実施の形態１に係る液晶表示装置用基準電圧回路１００は、階調基準電圧を生成するデジタルアナログコンバータ（ＤＡＣ）（デジタル階調基準電圧生成回路）１０と、共通電極電圧を生成する共通電極電圧生成回路２０とが設けられている。   In FIG. 1, a reference voltage circuit 100 for a liquid crystal display device according to the first embodiment includes a digital analog converter (DAC) (digital gradation reference voltage generation circuit) 10 that generates a gradation reference voltage, and a common electrode voltage. A common electrode voltage generation circuit 20 is provided.

また、共通電極電圧生成回路２０は、第１の端子２１と、第１の抵抗２２と、第２の端子２３と、第２の抵抗２４と、オペアンプ２５とから構成されている。   The common electrode voltage generation circuit 20 includes a first terminal 21, a first resistor 22, a second terminal 23, a second resistor 24, and an operational amplifier 25.

図２は、この発明の実施の形態１に係る液晶表示装置の構成を示すブロック図である。図２において、この基準電圧回路１００は、液晶パネル４０と、データ線駆動回路５０と、走査線駆動回路６０と、表示制御回路７０と、ＲＯＭ８０と、電源回路９０などとともに、液晶表示装置を構成している。なお、ＲＯＭ８０は、基準電圧回路１００に内蔵されてもよい。   FIG. 2 is a block diagram showing the configuration of the liquid crystal display device according to Embodiment 1 of the present invention. In FIG. 2, the reference voltage circuit 100 constitutes a liquid crystal display device together with a liquid crystal panel 40, a data line driving circuit 50, a scanning line driving circuit 60, a display control circuit 70, a ROM 80, a power supply circuit 90, and the like. is doing. The ROM 80 may be built in the reference voltage circuit 100.

つぎに、この実施の形態１に係る液晶表示装置用基準電圧回路の動作について図面を参照しながら説明する。   Next, the operation of the reference voltage circuit for a liquid crystal display device according to the first embodiment will be described with reference to the drawings.

基準電圧回路１００のデジタルアナログコンバータ（ＤＡＣ）１０は、ＲＯＭ８０からシリアルに送られてくる階調データを入力し、階調データの値に応じて、例えば２５６階調の階調基準電圧（Ｖ２５５正極、Ｖ２５４正極、Ｖ２５３正極、〜、Ｖ１２８正極、Ｖ１２７正極、Ｖ１２６正極、〜、Ｖ２正極、Ｖ１正極、Ｖ０正極、Ｖ０負極、Ｖ１負極、Ｖ２負極、〜、Ｖ１２６負極、Ｖ１２７負極、Ｖ１２８負極、〜、Ｖ２５３負極、Ｖ２５４負極、Ｖ２５５負極）を生成する。このＲＯＭ８０には、予め、例えば２５６階調の階調データが記憶されている。なお、図１では、一部の階調基準電圧を省略している。   The digital-to-analog converter (DAC) 10 of the reference voltage circuit 100 receives gradation data sent serially from the ROM 80, and, for example, 256 gradation gradation reference voltage (V255 positive electrode) according to the gradation data value. , V254 positive electrode, V253 positive electrode, ~, V128 positive electrode, V127 positive electrode, V126 positive electrode, ~, V2 positive electrode, V1 positive electrode, V0 positive electrode, V0 negative electrode, V1 negative electrode, V2 negative electrode, ~, V126 negative electrode, V127 negative electrode, V128 negative electrode, ~ , V253 negative electrode, V254 negative electrode, V255 negative electrode). In the ROM 80, for example, gradation data of 256 gradations is stored in advance. In FIG. 1, some of the gradation reference voltages are omitted.

また、共通電極電圧生成回路２０は、第１の端子２１に印加された所定の基準電圧を、第１の端子２１と第２の端子２３の間に接続された第１の抵抗２２と、第２の端子２３とアースの間に接続された第２の抵抗２４により分圧し、オペアンプ２５を通して共通電極電圧（Ｖｃｏｍ）を生成する。   The common electrode voltage generation circuit 20 generates a predetermined reference voltage applied to the first terminal 21, a first resistor 22 connected between the first terminal 21 and the second terminal 23, The voltage is divided by the second resistor 24 connected between the second terminal 23 and the ground, and the common electrode voltage (Vcom) is generated through the operational amplifier 25.

液晶表示装置は、交流駆動を行っている。この交流駆動電圧を液晶パネルの画素電極に加えている。画素電極と対を成す対向電極が液晶パネルの共通電極である。この共通電極には交流駆動による残留ＤＣが発生しないように、共通電極電圧（Ｖｃｏｍ）を印加する必要がある。   The liquid crystal display device performs AC driving. This AC drive voltage is applied to the pixel electrode of the liquid crystal panel. The counter electrode that forms a pair with the pixel electrode is a common electrode of the liquid crystal panel. It is necessary to apply a common electrode voltage (Vcom) to the common electrode so that residual DC due to AC driving does not occur.

この実施の形態１に係る液晶表示装置用基準電圧回路１００は、共通電極電圧（Ｖｃｏｍ）の調整を無くすとともに、さらに精度の良い残留ＤＣ対策を施すものである。具体的には、上述したようにデータ線駆動回路（ドライバ）５０に供給する階調基準電圧をデジタルアナログコンバータ（ＤＡＣ）１０を用いて生成し、液晶パネル４０の画素電極に印加する正極電圧と負極電圧を調整する。さらに、各階調基準電圧ごとに正負バランス調整を施す。   The reference voltage circuit 100 for a liquid crystal display device according to the first embodiment eliminates the adjustment of the common electrode voltage (Vcom) and provides a more accurate measure against residual DC. Specifically, as described above, the gradation reference voltage supplied to the data line driving circuit (driver) 50 is generated using the digital-analog converter (DAC) 10, and the positive voltage applied to the pixel electrode of the liquid crystal panel 40 is Adjust the negative voltage. Furthermore, positive / negative balance adjustment is performed for each gradation reference voltage.

上述したように、階調基準電圧（Ｖ２５５正極〜Ｖ０正極、Ｖ０負極〜Ｖ２５５負極）を、デジタルアナログコンバータ（ＤＡＣ）１０を用いて生成しており、共通電極電圧（Ｖｃｏｍ）の調整を不要としている。このデジタルアナログコンバータ（ＤＡＣ）１０では、出力電圧を正極性と負極性を独立で制御し出力できるため、共通電極電圧（Ｖｃｏｍ）の調整は不要である。   As described above, the gradation reference voltage (V255 positive to V0 positive, V0 negative to V255 negative) is generated using the digital-analog converter (DAC) 10, and adjustment of the common electrode voltage (Vcom) is unnecessary. Yes. In the digital-analog converter (DAC) 10, since the output voltage can be controlled by independently controlling the positive polarity and the negative polarity, adjustment of the common electrode voltage (Vcom) is unnecessary.

上記の基準電圧回路１００により、共通電極電圧（Ｖｃｏｍ）の調整は不要になる。また、階調基準電圧ごとに正負バランス調整が行われるため、従来よりも精度の高い調整が行われ、焼きつき発生の原因となる残留ＤＣの問題が解決する。すなわち、基準電圧回路１００では、基準階調ごとに正極性と負極性のバランスが調整されるため、従来例より残留ＤＣが少なく、焼きつきの発生を低減している。   The reference voltage circuit 100 eliminates the need to adjust the common electrode voltage (Vcom). In addition, since the positive / negative balance adjustment is performed for each gradation reference voltage, the adjustment with higher accuracy than the conventional one is performed, and the problem of residual DC that causes burn-in is solved. That is, in the reference voltage circuit 100, since the balance between positive polarity and negative polarity is adjusted for each reference gradation, the residual DC is less than in the conventional example, and the occurrence of burn-in is reduced.

なお、デジタルアナログコンバータ（ＤＡＣ）１０の出力数に余裕があれば、図３に示すように、共通電極電圧（Ｖｃｏｍ）をデジタルアナログコンバータ（ＤＡＣ）１０から出力しても良い。すなわち、デジタルアナログコンバータ（ＤＡＣ）（デジタル電圧生成回路）１０は、ＲＯＭ８０からシリアルに送られてくる階調データを入力し、階調データの値に応じて、例えば２５６階調の階調基準電圧（Ｖ２５５正極、Ｖ２５４正極、Ｖ２５３正極、〜、Ｖ１２８正極、Ｖ１２７正極、Ｖ１２６正極、〜、Ｖ２正極、Ｖ１正極、Ｖ０正極、Ｖ０負極、Ｖ１負極、Ｖ２負極、〜、Ｖ１２６負極、Ｖ１２７負極、Ｖ１２８負極、〜、Ｖ２５３負極、Ｖ２５４負極、Ｖ２５５負極）と共通電極電圧（Ｖｃｏｍ）を生成する。なお、図３では、一部の階調基準電圧を省略している。また、ＲＯＭ８０は、基準電圧回路１００に内蔵してもよい。この際も、共通電極電圧（Ｖｃｏｍ）の調整は不要で、正極性と負極性の階調基準電圧を制御すると良い。   If the number of outputs of the digital / analog converter (DAC) 10 is sufficient, the common electrode voltage (Vcom) may be output from the digital / analog converter (DAC) 10 as shown in FIG. That is, the digital-analog converter (DAC) (digital voltage generation circuit) 10 receives gradation data sent serially from the ROM 80, and, for example, 256 gradation reference voltages according to the gradation data value. (V255 positive electrode, V254 positive electrode, V253 positive electrode, ~, V128 positive electrode, V127 positive electrode, V126 positive electrode, ~, V2 positive electrode, V1 positive electrode, V0 positive electrode, V0 negative electrode, V1 negative electrode, V2 negative electrode, ~, V126 negative electrode, V127 negative electrode, V128 Negative electrode, V253 negative electrode, V254 negative electrode, V255 negative electrode) and a common electrode voltage (Vcom). In FIG. 3, some of the gradation reference voltages are omitted. The ROM 80 may be built in the reference voltage circuit 100. Also in this case, adjustment of the common electrode voltage (Vcom) is unnecessary, and it is preferable to control the positive and negative gradation reference voltages.

この実施の形態１では、簡略化のためデジタルアナログコンバータ（ＤＡＣ）１０を用いて階調基準電圧を生成しているが、本発明は必ずしもこの限りではない。デジタルアナログコンバータ（ＤＡＣ）１０を用いずに、図４に示すように、デジタルポテンショメータ（デジタル階調基準電圧生成回路）１０Ａを用いて正極性と負極性の電圧を制御して生成すれば、同様の効果が得られる。すなわち、デジタルポテンショメータ１０Ａは、表示制御回路７０やＲＯＭ８０などから送られてくる制御データ（ＩＮＣ、Ｕ／Ｄ、ＣＳ１０〜ＣＳ１：なお、記号の上に付するオバーラインは省略している。）を入力し、制御データに応じて、例えば２５６階調の階調基準電圧（Ｖ２５５正極、Ｖ２５４正極、Ｖ２５３正極、〜、Ｖ１２８正極、Ｖ１２７正極、Ｖ１２６正極、〜、Ｖ２正極、Ｖ１正極、Ｖ０正極、Ｖ０負極、Ｖ１負極、Ｖ２負極、〜、Ｖ１２６負極、Ｖ１２７負極、Ｖ１２８負極、〜、Ｖ２５３負極、Ｖ２５４負極、Ｖ２５５負極）を生成する。共通電極電圧（Ｖｃｏｍ）は、図１と同様に生成する。なお、図４では、一部の階調基準電圧を省略している。また、共通電極電圧（Ｖｃｏｍ）をデジタルポテンショメータ１０Ａから出力しても良い。さらに、ＲＯＭ８０は、基準電圧回路１００に内蔵してもよい。   In the first embodiment, the gradation reference voltage is generated using the digital analog converter (DAC) 10 for simplification, but the present invention is not necessarily limited to this. As shown in FIG. 4, without using the digital-analog converter (DAC) 10, the same can be achieved by controlling the positive and negative voltages using a digital potentiometer (digital gradation reference voltage generation circuit) 10A. The effect is obtained. In other words, the digital potentiometer 10A receives control data (INC, U / D, CS10 to CS1: overline attached to the symbol is omitted) sent from the display control circuit 70, the ROM 80, or the like. Depending on the input control data, for example, 256 gradation reference voltages (V255 positive electrode, V254 positive electrode, V253 positive electrode, ~ V128 positive electrode, V127 positive electrode, V126 positive electrode, ~, V2 positive electrode, V1 positive electrode, V0 positive electrode, V0 negative electrode, V1 negative electrode, V2 negative electrode,..., V126 negative electrode, V127 negative electrode, V128 negative electrode,..., V253 negative electrode, V254 negative electrode, V255 negative electrode). The common electrode voltage (Vcom) is generated as in FIG. In FIG. 4, some of the gradation reference voltages are omitted. Further, the common electrode voltage (Vcom) may be output from the digital potentiometer 10A. Further, the ROM 80 may be built in the reference voltage circuit 100.

この発明の実施の形態１に係る液晶表示装置用基準電圧回路の構成を示す図である。It is a figure which shows the structure of the reference voltage circuit for liquid crystal display devices which concerns on Embodiment 1 of this invention. この発明の実施の形態１に係る液晶表示装置の構成を示すブロック図である。It is a block diagram which shows the structure of the liquid crystal display device which concerns on Embodiment 1 of this invention. この発明の実施の形態１に係る液晶表示装置用基準電圧回路の別の構成を示す図である。It is a figure which shows another structure of the reference voltage circuit for liquid crystal display devices which concerns on Embodiment 1 of this invention. この発明の実施の形態１に係る液晶表示装置用基準電圧回路の他の別の構成を示す図である。It is a figure which shows another another structure of the reference voltage circuit for liquid crystal display devices which concerns on Embodiment 1 of this invention. 従来の液晶表示装置用基準電圧回路の構成を示す図である。It is a figure which shows the structure of the conventional reference voltage circuit for liquid crystal display devices.

符号の説明Explanation of symbols

１０ デジタルアナログコンバータ、１０Ａ デジタルポテンショメータ、２０ 共通電極電圧生成回路、２１ 第１の端子、２２ 第１の抵抗、２３ 第２の端子、２４ 第２の抵抗、２５ オペアンプ、４０ 液晶パネル、５０ データ線駆動回路、６０ 走査線駆動回路、７０ 表示制御回路、８０ ＲＯＭ、９０ 電源回路、１００ 液晶表示装置用基準電圧回路。   DESCRIPTION OF SYMBOLS 10 Digital analog converter, 10A digital potentiometer, 20 Common electrode voltage generation circuit, 21 1st terminal, 22 1st resistance, 23 2nd terminal, 24 2nd resistance, 25 operational amplifier, 40 liquid crystal panel, 50 data line Drive circuit, 60 scanning line drive circuit, 70 display control circuit, 80 ROM, 90 power supply circuit, 100 reference voltage circuit for liquid crystal display device.

Claims (8)

入力された階調データに基づいて複数階調の階調基準電圧を生成するデジタル階調基準電圧生成回路と、
共通電極電圧を生成する共通電極電圧生成回路と
を備えたことを特徴とする液晶表示装置用基準電圧回路。 A digital gradation reference voltage generation circuit for generating gradation reference voltages of a plurality of gradations based on input gradation data;
A reference voltage circuit for a liquid crystal display device, comprising: a common electrode voltage generation circuit that generates a common electrode voltage. 前記デジタル階調基準電圧生成回路は、外部のＲＯＭから入力された階調データに基づいて複数階調の正極及び負極の階調基準電圧を生成するデジタルアナログコンバータであり、
前記共通電極電圧生成回路は、所定の基準電圧を分圧した共通電極電圧を生成する
ことを特徴とする請求項１記載の液晶表示装置用基準電圧回路。 The digital gradation reference voltage generation circuit is a digital analog converter that generates a plurality of gradation positive and negative gradation reference voltages based on gradation data input from an external ROM,
The reference voltage circuit for a liquid crystal display device according to claim 1, wherein the common electrode voltage generation circuit generates a common electrode voltage obtained by dividing a predetermined reference voltage. 複数階調の階調データを記憶するＲＯＭをさらに備え、
前記デジタル階調基準電圧生成回路は、前記ＲＯＭから入力された階調データに基づいて複数階調の正極及び負極の階調基準電圧を生成するデジタルアナログコンバータであり、
前記共通電極電圧生成回路は、所定の基準電圧を分圧した共通電極電圧を生成する
ことを特徴とする請求項１記載の液晶表示装置用基準電圧回路。 A ROM for storing gradation data of a plurality of gradations;
The digital gradation reference voltage generation circuit is a digital analog converter that generates a plurality of gradation positive and negative gradation reference voltages based on gradation data input from the ROM,
The reference voltage circuit for a liquid crystal display device according to claim 1, wherein the common electrode voltage generation circuit generates a common electrode voltage obtained by dividing a predetermined reference voltage. 入力された階調データに基づいて複数階調の階調基準電圧を生成するとともに、共通電極電圧を生成するデジタル電圧生成回路
を備えたことを特徴とする液晶表示装置用基準電圧回路。 A reference voltage circuit for a liquid crystal display device, comprising: a digital voltage generation circuit that generates a plurality of gradation reference voltages based on input gradation data and generates a common electrode voltage. 前記デジタル電圧生成回路は、外部のＲＯＭから入力された階調データに基づいて複数階調の正極及び負極の階調基準電圧を生成するとともに、共通電極電圧を生成するデジタルアナログコンバータである
ことを特徴とする請求項４記載の液晶表示装置用基準電圧回路。 The digital voltage generation circuit is a digital / analog converter that generates a plurality of grayscale reference voltages for positive and negative electrodes based on grayscale data input from an external ROM, and generates a common electrode voltage. 5. The reference voltage circuit for a liquid crystal display device according to claim 4, wherein: 複数階調の階調データを記憶するＲＯＭをさらに備え、
前記デジタル電圧生成回路は、前記ＲＯＭから入力された階調データに基づいて複数階調の正極及び負極の階調基準電圧を生成するとともに、共通電極電圧を生成するデジタルアナログコンバータである
ことを特徴とする請求項４記載の液晶表示装置用基準電圧回路。 A ROM for storing gradation data of a plurality of gradations;
The digital voltage generation circuit is a digital / analog converter that generates a plurality of grayscale reference voltages for positive and negative electrodes based on grayscale data input from the ROM and generates a common electrode voltage. The reference voltage circuit for a liquid crystal display device according to claim 4. 前記デジタル階調基準電圧生成回路は、外部のＲＯＭから入力された制御データに基づいて複数階調の正極及び負極の階調基準電圧を生成するデジタルポテンショメータであり、
前記共通電極電圧生成回路は、所定の基準電圧を分圧した共通電極電圧を生成する
ことを特徴とする請求項１記載の液晶表示装置用基準電圧回路。 The digital gradation reference voltage generation circuit is a digital potentiometer that generates a plurality of gradation positive and negative gradation reference voltages based on control data input from an external ROM,
The reference voltage circuit for a liquid crystal display device according to claim 1, wherein the common electrode voltage generation circuit generates a common electrode voltage obtained by dividing a predetermined reference voltage. 制御データを記憶するＲＯＭをさらに備え、
前記デジタル階調基準電圧生成回路は、前記ＲＯＭから入力された制御データに基づいて複数階調の正極及び負極の階調基準電圧を生成するデジタルポテンショメータであり、
前記共通電極電圧生成回路は、所定の基準電圧を分圧した共通電極電圧を生成する
ことを特徴とする請求項１記載の液晶表示装置用基準電圧回路。 A ROM for storing control data;
The digital gradation reference voltage generation circuit is a digital potentiometer that generates a plurality of gradation positive and negative gradation reference voltages based on control data input from the ROM,
The reference voltage circuit for a liquid crystal display device according to claim 1, wherein the common electrode voltage generation circuit generates a common electrode voltage obtained by dividing a predetermined reference voltage.
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JP2008164850A (en) * 2006-12-27 2008-07-17 Lg Display Co Ltd Reference voltage adjustment method for liquid crystal display device
WO2010150562A1 (en) * 2009-06-22 2010-12-29 シャープ株式会社 Liquid crystal display device and method for driving same
JP2012098400A (en) * 2010-10-29 2012-05-24 Hitachi Displays Ltd Display device
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KR101825214B1 (en) 2011-06-17 2018-03-15 삼성디스플레이 주식회사 Liquid crystal display device and driving method thereof

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Publication number Priority date Publication date Assignee Title
JP2008164850A (en) * 2006-12-27 2008-07-17 Lg Display Co Ltd Reference voltage adjustment method for liquid crystal display device
WO2010150562A1 (en) * 2009-06-22 2010-12-29 シャープ株式会社 Liquid crystal display device and method for driving same
CN102804252A (en) * 2009-06-22 2012-11-28 夏普株式会社 Liquid crystal display device and method for driving same
JP2012098400A (en) * 2010-10-29 2012-05-24 Hitachi Displays Ltd Display device
US9001090B2 (en) 2010-10-29 2015-04-07 Japan Display Inc. Display device
US9378710B2 (en) 2010-10-29 2016-06-28 Japan Display Inc. Display device
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