JP2007171243A - Liquid crystal display driver - Google Patents

Liquid crystal display driver Download PDF

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JP2007171243A
JP2007171243A JP2005364543A JP2005364543A JP2007171243A JP 2007171243 A JP2007171243 A JP 2007171243A JP 2005364543 A JP2005364543 A JP 2005364543A JP 2005364543 A JP2005364543 A JP 2005364543A JP 2007171243 A JP2007171243 A JP 2007171243A
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liquid crystal
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vlcd
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negative
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JP4173504B2 (en
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Haruo Hayashi
春生 林
Wen-Yu Liao
文裕 廖
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Sitronix Technology Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display driver which switches a liquid crystal positive voltage (+Vlcd) and a liquid crystal negative voltage (-Vlcd) by a voltage switching control circuit to alternately output them and invariably provides required voltages of a segment driver and a common driver. <P>SOLUTION: It is possible to make the liquid crystal positive voltage (+Vlcd) and the liquid crystal negative voltage (-Vlcd) nonexistent simultaneously, so that the liquid crystal display driver switches the liquid crystal positive voltage (+Vlcd) and the liquid crystal negative voltage (-Vlcd) by the voltage switching control circuit to alternately output them and invariably provides required voltages of the segment driver and the common driver. Since it is enough for the liquid crystal display driver to select an original Vlcd-GND in accordance with original circuit design in a process of manufacturing a semiconductor, manufacturing costs are considerably reduced because equipment for the process of manufacturing the liquid crystal display driver does not require equipment for a process of high voltage manufacturing and allows component sizes to be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、液晶ディスプレイドライバに関するもので、特に液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）を自動的に切替えする回路であり、駆動電圧回路の製造工程においてはＶｌｃｄ-ＧＮＤの選択が可能である液晶ディスプレイドライバに関するものである。   The present invention relates to a liquid crystal display driver, and more particularly to a circuit that automatically switches between a liquid crystal positive voltage (+ Vlcd) and a liquid crystal negative voltage (-Vlcd). In the manufacturing process of a drive voltage circuit, Vlcd-GND is selected. It relates to a liquid crystal display driver that is possible.

ＳＴＮｃ（Ｓｕｐｅｒ Ｔｗｉｓｔｅｄ Ｎｅｍａｔｉｃ）液晶ディスプレイ（ＬＣＤ：Ｌｉｑｕｉｄ Ｃｒｙｓｔａｌ Ｄｉｓｐｌａｙ）ドライバの５レベル駆動方法においては、五つの駆動電圧を使って一つの液晶ディスプレイを駆動する。詳しい説明を加えれば、四つの駆動電圧及び一つの分段負電圧（−Ｖｓｅｇ）である。一般のＨｉＦａｓ（Ｈｉｇｈ Ｆｒｅｑｕｅｎｃｙ Ａｍｐｌｉｔｕｄｅ Ｓｅｌｅｃｔｉｏｎ Ｍｅｔｈｏｄ）によるＩＣ駆動の規格は、液晶正電圧（＋Ｖｌｃｄ）が＋２０Ｖ、液晶負電圧（-Ｖｌｃｄ）は−２０Ｖで、半導体製造工程では耐圧４０Ｖの高圧製造工程を選択する必要がある。   In a five-level driving method of an STNc (Super Twisted Nematic) liquid crystal display (LCD) driver, one liquid crystal display is driven using five driving voltages. More specifically, there are four drive voltages and one divided negative voltage (-Vseg). The standard of IC drive by general HiFas (High Frequency Amplitude Selection Method) is liquid crystal positive voltage (+ Vlcd) is + 20V, liquid crystal negative voltage (-Vlcd) is -20V, and semiconductor manufacturing process selects high voltage manufacturing process with withstand voltage 40V There is a need to.

図１に、５レベル駆動方法に基づいて運用された従来品液晶ディスプレイドライバのフローチャートを示す。図1を参照すると、従来の液晶ディスプレイドライバは駆動電圧発生回路１１を含んでおり、これによって五つの駆動電圧を発生させ、また、この五つの駆動電圧は、液晶正電圧（＋Ｖｌｃｄ）、液晶負電圧（-Ｖｌｃｄ）、分段正電圧（＋Ｖｓｅｇ）、共電極電圧（Ｖｃｏｍ）、分段負電圧（−Ｖｓｅｇ）を含んでいる。駆動極性信号（ＣＯＮ）に制御されたセグメントドライバ１１は分段正電圧（＋Ｖｓｅｇ）及び分段負電圧（−Ｖｓｅｇ）を受けて分段駆動信号（ＳＥＧ）を発生させる。駆動極性信号（ＣＯＮ）に制御されたコモンドライバ１３は、液晶正電圧（＋Ｖｌｃｄ）、共電極電圧（Ｖｃｏｍ）及び液晶負電圧（-Ｖｌｃｄ）を受けて通用駆動信号（ＣＯＭ）を発生させる。駆動極性信号（ＣＯＮ）の分段駆動信号（ＳＥＧ）と通用駆動信号（ＣＯＭ）の電圧ウェーブ図は図２に示すとおりである。   FIG. 1 shows a flowchart of a conventional liquid crystal display driver operated based on the five-level driving method. Referring to FIG. 1, the conventional liquid crystal display driver includes a driving voltage generation circuit 11 to generate five driving voltages. The five driving voltages are a liquid crystal positive voltage (+ Vlcd), a liquid crystal negative voltage, and the like. A voltage (-Vlcd), a divided positive voltage (+ Vseg), a common electrode voltage (Vcom), and a divided negative voltage (-Vseg) are included. The segment driver 11 controlled by the drive polarity signal (CON) receives the divided positive voltage (+ Vseg) and the divided negative voltage (−Vseg) and generates a divided drive signal (SEG). The common driver 13 controlled by the drive polarity signal (CON) receives the liquid crystal positive voltage (+ Vlcd), the common electrode voltage (Vcom), and the liquid crystal negative voltage (−Vlcd) and generates a common drive signal (COM). A voltage wave diagram of the split drive signal (SEG) and the common drive signal (COM) of the drive polarity signal (CON) is as shown in FIG.

従来の液晶ディスプレイドライバにおいて、図２ではっきりわかるように、液晶ディスプレイ（例えばＳＴＮ ＬＣＤやＣＳＴＮ ＬＣＤ）の操作時、通用駆動信号（ＣＯＭ）の理論形態において表示時間をポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）とネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）に分けることができ、その内、ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）の理論形態では、低電圧、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）を高電圧とし、（図２参照）もしくは、ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）の理論形態は高電圧、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）を低電圧（図中未表示）とする。図２に示す駆動極性信号（ＣＯＮ）の理論形態に基づくと、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）段階では液晶負電圧（-Ｖｌｃｄ）が、ネガティブ区間（ＮＮｅｇａｔｉｖｅ Ｆｒａｍｅ）段階では液晶正電圧（＋Ｖｌｃｄ）が必要で、また、二組の電圧具は以下の関係となる。
+Ｖｌｃｄ-（-Ｖｓｅｇ）＝+Ｖｓｅｇ-（-Ｖｌｃｄ）
例えば +Ｖｌｃｄ＝２０Ｖ；-Ｖｌｃｄ＝-１５Ｖ；-Ｖｓｅｇ＝0Ｖ；Ｖｓｅｇ＝5Ｖ。
即ち、液晶ディスプレイドライバの半導体製造工程では、耐圧を選択して駆動電圧発生回路１１の最高電圧+Ｖｌｃｄと最低電圧-Ｖｌｃｄ間の圧力差を得なければならず、詳しく言えば、半導体製造工程において、高圧（４０Ｖ）部品完成を考慮しなければならない。 In a conventional liquid crystal display driver, as clearly shown in FIG. 2, when operating a liquid crystal display (for example, STN LCD or CSTN LCD), the display time is set to a positive period (Positive Frame) and a negative in the theoretical form of a common drive signal (COM). The theoretical form of the negative section (Negative Frame) can be divided into a low voltage and a positive section (Positive Frame) as a high voltage (see FIG. 2) or a negative section (Negative Frame). The theoretical form of “Frame” is a high voltage, and the positive period (Positive Frame) is a low voltage (not shown in the figure). According to the theoretical form of the drive polarity signal (CON) shown in FIG. 2, a liquid crystal negative voltage (-Vlcd) is required in the positive period (-Positive Frame) stage, and a liquid crystal positive voltage (+ Vlcd) is required in the negative period (NN Negative Frame) stage. In addition, the two sets of voltage tools have the following relationship.
+ Vlcd − (− Vseg) = + Vseg − (− Vlcd)
For example, + Vlcd = 20V; −Vlcd = −15V; −Vseg = 0V; Vseg = 5V.
That is, in the semiconductor manufacturing process of the liquid crystal display driver, it is necessary to select a withstand voltage and obtain a pressure difference between the maximum voltage + Vlcd and the minimum voltage −Vlcd of the drive voltage generation circuit 11. High voltage (40V) part completion must be considered.

しかしながら、高圧部品に必要なチップ面積は非常に大きく、耐圧が大きくなれば高圧部品のサイズも益々増大する。また、高圧部品の半導体製造工程は、一般の半導体製造工程に必要な設備コストよりも更に高く、且つサイズも大きくなればなる程、材料需要も増大、コストは相当アップする。   However, the chip area required for the high voltage component is very large, and the size of the high voltage component increases more and more as the breakdown voltage increases. In addition, the semiconductor manufacturing process for high-voltage components is higher than the equipment cost required for a general semiconductor manufacturing process, and the larger the size, the more the material demand increases and the cost increases considerably.

本発明は、電圧切替え制御回路を有する液晶ディスプレイドライバを提案する。液晶ディスプレイドライバの液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）はそれぞれネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）もしくはポジティブ区間（ＰｏｓｉｔｉｖｅＦｒａｍｅ）に現れ、同時に存在することがない。即ち、液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）は同時に存在させないことも可能である。よって本発明は電圧切替え制御回路により液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）を切替ええて交互に出力、且つ、セグメントドライバとコモンドライバの必要電圧を変わりなく提供する。また、本発明の液晶ディスプレイドライバは、半導体製造工程において元来の回路設計に応じて元来のＶｌｃｄ-ＧＮＤを選択すればよく、よって、液晶ディスプレイドライバの製造工程設備は、高電圧製造工程設備が不要で部品サイズも縮小可能である為、大幅な製造コスト削減となる。   The present invention proposes a liquid crystal display driver having a voltage switching control circuit. The liquid crystal positive voltage (+ Vlcd) and the liquid crystal negative voltage (−Vlcd) of the liquid crystal display driver appear in a negative period (Negative Frame) or a positive period (PositiveFrame), respectively, and do not exist at the same time. In other words, the liquid crystal positive voltage (+ Vlcd) and the liquid crystal negative voltage (−Vlcd) may not exist simultaneously. Therefore, the present invention switches the liquid crystal positive voltage (+ Vlcd) and the liquid crystal negative voltage (−Vlcd) by the voltage switching control circuit to alternately output the voltage required for the segment driver and the common driver without change. In addition, the liquid crystal display driver of the present invention only needs to select the original Vlcd-GND according to the original circuit design in the semiconductor manufacturing process, and therefore the liquid crystal display driver manufacturing process equipment is a high-voltage manufacturing process equipment. Is not required and the part size can be reduced, which greatly reduces the manufacturing cost.

本発明の液晶ディスプレイドライバは、駆動電圧発生回路、セグメントドライバ、コモンドライバ及び電圧切替え制御回路によって構成され、駆動電圧発生回路は、五つの駆動電圧を発生させ、その電圧とは、液晶正電圧（＋Ｖｌｃｄ）、液晶負電圧（-Ｖｌｃｄ）、分段正電圧（＋Ｖｓｅｇ）、共電極電圧（Ｖｃｏｍ）、分段負電圧（−Ｖｓｅｇ）である。セグメントドライバは分段正電圧（＋Ｖｓｅｇ）及び分段負電圧（−Ｖｓｅｇ）を受けて分段駆動信号（ＳＥＧ）を出力、電圧切替え制御回路は液晶正電圧（＋Ｖｌｃｄ）、分段正電圧（＋Ｖｓｅｇ）、分段負電圧（−Ｖｓｅｇ）、液晶負電圧（-Ｖｌｃｄ）を受け第一出力端と第二出力端からそれぞれ出力された液晶正電圧（＋Ｖｌｃｄ）、液晶負電圧（-Ｖｌｃｄ）と共電極電圧（Ｖｃｏｍ）はコモンドライバが受けて通用駆動信号（ＣＯＭ）を出力する。   The liquid crystal display driver of the present invention includes a drive voltage generation circuit, a segment driver, a common driver, and a voltage switching control circuit. The drive voltage generation circuit generates five drive voltages, and the voltage is a liquid crystal positive voltage ( + Vlcd), liquid crystal negative voltage (−Vlcd), divided positive voltage (+ Vseg), common electrode voltage (Vcom), and divided negative voltage (−Vseg). The segment driver receives the divided positive voltage (+ Vseg) and the divided negative voltage (−Vseg) and outputs the divided drive signal (SEG). The voltage switching control circuit has the liquid crystal positive voltage (+ Vlcd) and the divided positive voltage (+ Vseg). ), A stage negative voltage (−Vseg), a liquid crystal negative voltage (−Vlcd), and the liquid crystal positive voltage (+ Vlcd) and the liquid crystal negative voltage (−Vlcd) respectively output from the first output terminal and the second output terminal. The electrode voltage (Vcom) is received by the common driver and outputs a common drive signal (COM).

本発明に含まれる電圧切替え制御回路は第一スイッチ、第二スイッチを構成要素とし、その内の第一スイッチは第一出力端を液晶正電圧（＋Ｖｌｃｄ）の出力端、もしくは分段正電圧（＋Ｖｓｅｇ）の出力端に接続した後、第一出力端はコモンドライバの正電圧端に接続、また第二スイッチは液晶負電圧（-Ｖｌｃｄ）もしくは分段負電圧（−Ｖｓｅｇ）の出力端に接続した後、第二出力端はコモンドライバの負電圧端に接続する。   The voltage switching control circuit included in the present invention includes a first switch and a second switch as components, and the first switch has a first output terminal connected to an output terminal of a liquid crystal positive voltage (+ Vlcd) or a divided positive voltage ( After connecting to the output terminal of + Vseg), the first output terminal is connected to the positive voltage terminal of the common driver, and the second switch is connected to the output terminal of the liquid crystal negative voltage (-Vlcd) or the divided negative voltage (-Vseg). After that, the second output terminal is connected to the negative voltage terminal of the common driver.

更に詳細を示すが、本発明を液晶ディスプレイに繋いで操作する場合、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）段階では、液晶負電圧（-Ｖｌｃｄ）のみの使用となり、またネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）段階では液晶正電圧（＋Ｖｌｃｄ）のみの使用となり、液晶負電圧（-Ｖｌｃｄ）と液晶正電圧（＋Ｖｌｃｄ）は同時に存在することはない。よって、表示状態がポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）である時、第一スイッチは第一出力端分段正電圧（＋Ｖｓｅｇ）の出力端に、第二スイッチは第二出力端を液晶負電圧（-Ｖｌｃｄ）の出力端に接続する。つまり、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）の場合、電圧切替え制御回路は分段正電圧（＋Ｖｓｅｇ）と液晶負電圧（-Ｖｌｃｄ）をコモンドライバまで導通、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）段階においてのみコモンドライバの必要電圧となる。   As will be described in more detail, when the present invention is connected to a liquid crystal display, only the negative liquid crystal voltage (-Vlcd) is used in the positive period (Positive Frame) stage, and the positive liquid crystal stage is used in the negative period (Negative Frame) stage. Only the voltage (+ Vlcd) is used, and the liquid crystal negative voltage (−Vlcd) and the liquid crystal positive voltage (+ Vlcd) do not exist at the same time. Therefore, when the display state is the positive period (Positive Frame), the first switch is connected to the output terminal of the first output terminal divided positive voltage (+ Vseg), and the second switch is connected to the second output terminal of the liquid crystal negative voltage (−Vlcd). ) Connect to the output terminal. In other words, in the positive period (Positive Frame), the voltage switching control circuit conducts the divided positive voltage (+ Vseg) and the liquid crystal negative voltage (−Vlcd) to the common driver, and the common driver is required only in the positive period (Positive Frame) stage. Voltage.

表示状態がネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）段階である場合、第一スイッチは第一出力端を液晶正電圧（＋Ｖｌｃｄ）の出力端に接続、第二スイッチは第二出力端を分段負電圧（−Ｖｓｅｇ）の出力端に接続させ、よってネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）においては電圧切替え制御回路は液晶正電圧（＋Ｖｌｃｄ）と分段負電圧（−Ｖｓｅｇ）を導通、液晶正電圧（＋Ｖｌｃｄ）はネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）段階においてのみコモンドライバの必要電圧となる。   When the display state is in the negative frame (Negative Frame) stage, the first switch connects the first output terminal to the output terminal of the liquid crystal positive voltage (+ Vlcd), and the second switch connects the second output terminal to the divided negative voltage (− Vseg) is connected to the output terminal, so that in the negative period (Negative Frame), the voltage switching control circuit conducts the liquid crystal positive voltage (+ Vlcd) and the divided negative voltage (−Vseg), and the liquid crystal positive voltage (+ Vlcd) is in the negative period. Only in the (Negative Frame) stage, the voltage is required for the common driver.

本発明は、電圧切替え制御回路をポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）またはネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）の異なる段階において液晶負電圧（-Ｖｌｃｄ）と液晶正電圧（＋Ｖｌｃｄ）を切替えコモンドライバに入力するもので、同一時間に液晶負電圧（-Ｖｌｃｄ）と液晶正電圧（＋Ｖｌｃｄ）を同時に存在させないことを特徴としており、液晶ディスプレイドライバの半導体製造工程においては元来の回路設計に基づいて元来のＶｌｃｄ-ＧＮＤを選択すればよく、セグメントドライバとコモンドライバの必要電圧を変わりなく提供する。   In the present invention, the voltage switching control circuit inputs a liquid crystal negative voltage (−Vlcd) and a liquid crystal positive voltage (+ Vlcd) to a switching common driver at different stages in a positive period (Positive Frame) or a negative period (Negative Frame). The liquid crystal negative voltage (-Vlcd) and the liquid crystal positive voltage (+ Vlcd) do not exist at the same time at the same time. In the liquid crystal display driver semiconductor manufacturing process, the original Vlcd-GND is based on the original circuit design. The required voltage of the segment driver and the common driver is provided without change.

請求項１の発明は、液晶ディスプレイドライバは、次の構成要素（ａ）（ｂ）（ｃ）（ｄ）を含み、
（ａ）駆動電圧発生回路は、これによって液晶正電圧（＋Ｖｌｃｄ）液晶負電圧（-Ｖｌｃｄ）分段正電圧（＋Ｖｓｅｇ）共電極電圧（Ｖｃｏｍ）及び分段負電圧（−Ｖｓｅｇ）を発生させ出力し、
（ｂ）セグメントドライバは、駆動極性信号（ＣＯＮ）によって制御されており、分段正電圧（＋Ｖｓｅｇ）及び分段負電圧（−Ｖｓｅｇ）を受けて分段駆動信号（ＳＥＧ）を出力し、
（ｃ）電圧切替え制御回路は駆動極性信号（ＣＯＮ）によって制御されており、液晶正電圧（＋Ｖｌｃｄ）と分段正電圧（＋Ｖｓｅｇ）及び分段負電圧（−Ｖｓｅｇ）と液晶負電圧（-Ｖｌｃｄ）を受けて、ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）とポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）状態での駆動極性信号（ＣＯＮ）に対応して制御された液晶正電圧（＋Ｖｌｃｄ）または液晶負電圧（-Ｖｌｃｄ）を、第一出力端と第二出力端から交互に出力し、
（ｄ）コモンドライバは駆動極性信号（ＣＯＮ）によって制御されており、電圧切替え制御回路両出力端から提供された液晶正電圧（＋Ｖｌｃｄ）、液晶負電圧（-Ｖｌｃｄ）及び共電極電圧（Ｖｃｏｍ）を受けて通用駆動信号（ＣＯＭ）を出力することを特徴とする、液晶ディスプレイドライバとしている。
請求項２の発明は、請求項１記載の液晶ディスプレイドライバにおいて、前記電圧切替え制御回路は、第一スイッチと第二スイッチを含み、その第一スイッチは、第一出力端を液晶正電圧（＋Ｖｌｃｄ）出力端または分段正電圧（＋Ｖｓｅｇ）出力端に接続、またその第二スイッチは液晶負電圧（-Ｖｌｃｄ）出力端または分段負電圧（−Ｖｓｅｇ）出力端に接続することを特徴とする、液晶ディスプレイドライバとしている。
請求項３の発明は、請求項２記載の液晶ディスプレイドライバにおいて、第一出力端と第二出力端の電性を保存コンデンサの正電圧端（ＶＰ）または負電圧端（ＶＮ）にそれぞれ接続することを特徴とする、液晶ディスプレイドライバとしている。
請求項４の発明は、請求項２記載の液晶ディスプレイドライバにおいて、駆動極性信号（ＣＯＮ）はポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）の理論形態において、第一スイッチは第一出力端を分段正電圧（＋Ｖｓｅｇ）出力端に、電圧切替え制御回路は第二出力端を液晶負電圧（-Ｖｌｃｄ）の出力端に接続することを特徴とする、液晶ディスプレイドライバとしている。
請求項５の発明は、請求項２記載の液晶ディスプレイドライバにおいて、駆動極性信号（ＣＯＮ）はネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）の理論形態である場合、第一スイッチは第一出力端を液晶正電圧（＋Ｖｌｃｄ）出力端に、第二スイッチは第二出力端を分段負電圧（−Ｖｓｅｇ）の出力端に接続することを特徴とする、液晶ディスプレイドライバとしている。 In the invention of claim 1, the liquid crystal display driver includes the following components (a) (b) (c) (d):
(A) The drive voltage generation circuit generates and outputs a liquid crystal positive voltage (+ Vlcd), a liquid crystal negative voltage (-Vlcd), a divided positive voltage (+ Vseg), a common electrode voltage (Vcom), and a divided negative voltage (-Vseg). And
(B) The segment driver is controlled by a drive polarity signal (CON), receives a divided positive voltage (+ Vseg) and a divided negative voltage (−Vseg), and outputs a divided drive signal (SEG).
(C) The voltage switching control circuit is controlled by a drive polarity signal (CON), and a liquid crystal positive voltage (+ Vlcd), a divided positive voltage (+ Vseg), a divided negative voltage (−Vseg), and a liquid crystal negative voltage (−Vlcd). ), The liquid crystal positive voltage (+ Vlcd) or the liquid crystal negative voltage (−Vlcd) controlled according to the drive polarity signal (CON) in the negative period (Negative Frame) and the positive period (Positive Frame) state, Output alternately from the first output end and the second output end,
(D) The common driver is controlled by a drive polarity signal (CON), and a liquid crystal positive voltage (+ Vlcd), a liquid crystal negative voltage (−Vlcd), and a common electrode voltage (Vcom) provided from both output terminals of the voltage switching control circuit. In response, the liquid crystal display driver outputs a common drive signal (COM).
According to a second aspect of the present invention, in the liquid crystal display driver according to the first aspect, the voltage switching control circuit includes a first switch and a second switch, and the first switch has a first output terminal connected to a liquid crystal positive voltage (+ Vlcd). ) It is connected to the output terminal or the divided positive voltage (+ Vseg) output terminal, and the second switch is connected to the liquid crystal negative voltage (−Vlcd) output terminal or the divided negative voltage (−Vseg) output terminal. , As a liquid crystal display driver.
According to a third aspect of the present invention, in the liquid crystal display driver according to the second aspect, the first output terminal and the second output terminal are connected to the positive voltage terminal (VP) or the negative voltage terminal (VN) of the storage capacitor, respectively. This is a liquid crystal display driver.
According to a fourth aspect of the present invention, in the liquid crystal display driver according to the second aspect, the drive polarity signal (CON) is in a theoretical form of a positive frame (Positive Frame), and the first switch splits the first output terminal into a positive voltage (+ Vseg). ) At the output end, the voltage switching control circuit is a liquid crystal display driver characterized in that the second output end is connected to the output end of the liquid crystal negative voltage (-Vlcd).
According to a fifth aspect of the present invention, in the liquid crystal display driver according to the second aspect, when the drive polarity signal (CON) is a theoretical form of a negative period (Negative Frame), the first switch connects the first output terminal to the liquid crystal positive voltage ( The liquid crystal display driver is characterized in that the second switch connects the second output terminal to the output terminal of the divided negative voltage (-Vseg) at the + Vlcd) output terminal.

本発明の液晶ディスプレイドライバは、電圧切替え制御回路３０を液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）に切替ええる為、同一時間に液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）が存在することはなく、よって、液晶ディスプレイドライバは半導体製造工程において、元来の回路設計に基づき元来のＶｌｅｄ-ＧＮＤを選択可能で、且つセグメントドライバ２２とコモンドライバ２３に必要な電圧も変わりなく提供できるという特徴を持つ。それにより、製造工程において高電圧製造工程の設備を必要とすることなく、部品サイズも縮小可能である為、大幅に液晶ディスプレイドライバの製造コストを削減するのに効果的である。   The liquid crystal display driver of the present invention switches the voltage switching control circuit 30 between the liquid crystal positive voltage (+ Vlcd) and the liquid crystal negative voltage (−Vlcd), so that the liquid crystal positive voltage (+ Vlcd) and the liquid crystal negative voltage (−Vlcd) are the same time. Therefore, the liquid crystal display driver can select the original Vled-GND based on the original circuit design in the semiconductor manufacturing process, and the voltage required for the segment driver 22 and the common driver 23 also changes. It has the feature that it can be provided without any problems. Thereby, the component size can be reduced without requiring equipment for a high-voltage manufacturing process in the manufacturing process, which is effective in greatly reducing the manufacturing cost of the liquid crystal display driver.

図３に、５レベル駆動方法に基づいて動く、本発明実施例の液晶ディスプレイドライバのフローチャートを示す。本発明の液晶ディスプレイドライバは、５つの駆動電圧を発生させる駆動電圧発生回路２１を含み、この５つの駆動電圧とは、液晶正電圧（＋Ｖｌｃｄ）、液晶負電圧（-Ｖｌｃｄ）、分段正電圧（＋Ｖｓｅｇ）、共電極電圧（Ｖｃｏｍ）及び分段負電圧（−Ｖｓｅｇ）のことである。駆動極性信号（ＣＯＮ）によって制御されたセグメントドライバ２２は分段正電圧（＋Ｖｓｅｇ）と分段負電圧（−Ｖｓｅｇ）を受けて分段駆動信号（ＳＥＧ）を出力する。また、駆動極性信号（ＣＯＮ）に制御された電圧切替え制御回路３０は、液晶正電圧（＋Ｖｌｃｄ）分段正電圧（＋Ｖｓｅｇ）分段負電圧（−Ｖｓｅｇ）液晶負電圧（-Ｖｌｃｄ）を受ける。且つ、駆動極性信号（ＣＯＮ）に制御されたコモンドライバ２３は、電圧切替え制御回路３０の第一出力端３０１と第二出力端３０２からそれぞれ出力された液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）及び共電極電圧（Ｖｃｏｍ）を受けて通用駆動信号（ＣＯＭ）を出す。   FIG. 3 shows a flowchart of the liquid crystal display driver according to the embodiment of the present invention which operates based on the five-level driving method. The liquid crystal display driver of the present invention includes a drive voltage generation circuit 21 that generates five drive voltages. The five drive voltages are a liquid crystal positive voltage (+ Vlcd), a liquid crystal negative voltage (−Vlcd), and a divided positive voltage. (+ Vseg), common electrode voltage (Vcom), and divided negative voltage (−Vseg). The segment driver 22 controlled by the drive polarity signal (CON) receives the divided positive voltage (+ Vseg) and the divided negative voltage (−Vseg), and outputs a divided drive signal (SEG). Further, the voltage switching control circuit 30 controlled by the drive polarity signal (CON) receives the liquid crystal positive voltage (+ Vlcd) divided positive voltage (+ Vseg) divided negative voltage (-Vseg) and liquid crystal negative voltage (-Vlcd). Further, the common driver 23 controlled by the drive polarity signal (CON) has a liquid crystal positive voltage (+ Vlcd) and a liquid crystal negative voltage (+) output from the first output terminal 301 and the second output terminal 302 of the voltage switching control circuit 30, respectively. -Vlcd) and the common electrode voltage (Vcom), and a common drive signal (COM) is output.

電圧切替え制御回路３０は第一スイッチ３１及び第二スイッチ３２を含む。第一スイッチ３１は駆動極性信号（ＣＯＮ）に対応しており、第一スイッチ３１は液晶正電圧（＋Ｖｌｃｄ）及び分段正電圧（＋Ｖｓｅｇ）の出力端に接続され、並びに、第一出力端３０１はコモンドライバ２３の液晶正電圧（＋Ｖｌｃｄ）に接続されている。第二スイッチ３２も駆動極性信号（ＣＯＮ）に対応しており、第二出力端３０２は液晶負電圧（-Ｖｌｃｄ）分段負電圧（−Ｖｓｅｇ）の出力端に接続され、並びに第二スイッチ３２はコモンドライバ２３の分段負電圧（−Ｖｓｅｇ）に接続されている。   The voltage switching control circuit 30 includes a first switch 31 and a second switch 32. The first switch 31 corresponds to the drive polarity signal (CON). The first switch 31 is connected to the output terminals of the liquid crystal positive voltage (+ Vlcd) and the divided positive voltage (+ Vseg), and the first output terminal 301. Is connected to the liquid crystal positive voltage (+ Vlcd) of the common driver 23. The second switch 32 also corresponds to the drive polarity signal (CON), the second output terminal 302 is connected to the output terminal of the liquid crystal negative voltage (−Vlcd) divided negative voltage (−Vseg), and the second switch 32. Is connected to the divided negative voltage (−Vseg) of the common driver 23.

更に詳細に説明すると、本発明は液晶ディスプレイドライバ（例えばＳＴＮ ＬＣＤやＣＳＴＮ ＬＣＤ）を操作する場合、駆動極性信号（ＣＯＮ）の理論形態は、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）とネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）の時間を表示する。ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）の理論形態は低電圧、ポジティブ区間（ＰｏｓｉｔｉｖｅＦｒａｍｅ）の理論形態は高電圧である（図２参照）。もしくは、ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）の理論形態は高電圧、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）は低電圧である（図中未表示）。その内、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）段階では液晶負電圧（-Ｖｌｃｄ）のみの使用、ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）段階では液晶正電圧（＋Ｖｌｃｄ）のみの使用となる。液晶負電圧（-Ｖｌｃｄ）と液晶正電圧（＋Ｖｌｃｄ）は同時に存在しないことが特性である。しかし本発明は、図2に示すように駆動電圧の分段駆動信号（ＳＥＧ）と通用駆動信号（ＣＯＭ）と同様の電圧ウェーブ図が必要である。   More specifically, when the present invention operates a liquid crystal display driver (eg, STN LCD or CSTN LCD), the theoretical form of the drive polarity signal (CON) is that of a positive frame (Positive Frame) and a negative frame (Negative Frame). Display time. The theoretical form of the negative period (Negative Frame) is a low voltage, and the theoretical form of the positive period (Positive Frame) is a high voltage (see FIG. 2). Or, the theoretical form of the negative section (Negative Frame) is a high voltage, and the positive section (Positive Frame) is a low voltage (not shown in the figure). Among them, only the liquid crystal negative voltage (−Vlcd) is used in the positive period (Positive Frame) stage, and only the liquid crystal positive voltage (+ Vlcd) is used in the negative period (Negative Frame) stage. The characteristic is that the liquid crystal negative voltage (−Vlcd) and the liquid crystal positive voltage (+ Vlcd) do not exist simultaneously. However, as shown in FIG. 2, the present invention requires a voltage wave diagram similar to the drive voltage staged drive signal (SEG) and the common drive signal (COM).

図２に示すとおり、駆動極性信号（ＣＯＮ）はポジティブ区間（ＰｏｓｉｔｉｖｅＦｒａｍｅ）において、分段駆動信号（ＳＥＧ）と通用駆動信号（ＣＯＭ）の電圧出力には、分段正電圧（＋Ｖｓｅｇ）共電極電圧（Ｖｃｏｍ）分段負電圧（−Ｖｓｅｇ）及び液晶負電圧（-Ｖｌｃｄ）が必要である。よって、表示状態がポジティブ区間（ＰｏｓｉｔｉｖｅＦｒａｍｅ）段階である場合、第一スイッチ３１は第一出力端３０１を分段正電圧（＋Ｖｓｅｇ）の出力端に接続させ、第二スイッチ３２は第二出力端３０２を液晶負電圧（-Ｖｌｃｄ）の出力端に接続させる。このように、駆動電圧発生回路２１で出力された分段正電圧（＋Ｖｓｅｇ）と分段負電圧（−Ｖｓｅｇ）はセグメントドライバ２２で使用され、並びに分段正電圧（＋Ｖｓｅｇ）共電極電圧（Ｖｃｏｍ）液晶負電圧（-Ｖｌｃｄ）はコモンドライバ２３で用いられる。   As shown in FIG. 2, the drive polarity signal (CON) is a positive voltage (+ Vseg) common electrode voltage for the voltage output of the split drive signal (SEG) and the common drive signal (COM) in the positive period (PositiveFrame). (Vcom) A divided negative voltage (-Vseg) and a liquid crystal negative voltage (-Vlcd) are required. Therefore, when the display state is the positive section (PositiveFrame) stage, the first switch 31 connects the first output terminal 301 to the output terminal of the divided positive voltage (+ Vseg), and the second switch 32 connects the second output terminal 302. Is connected to the output terminal of the liquid crystal negative voltage (-Vlcd). As described above, the divided positive voltage (+ Vseg) and the divided negative voltage (−Vseg) output from the drive voltage generation circuit 21 are used by the segment driver 22, and the divided positive voltage (+ Vseg) common electrode voltage (Vcom). The liquid crystal negative voltage (−Vlcd) is used by the common driver 23.

駆動極性信号（ＣＯＮ）がネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）段階である場合、分段駆動信号（ＳＥＧ）と通用駆動信号（ＣＯＭ）電力出力には、液晶正電圧（＋Ｖｌｃｄ）分段正電圧（＋Ｖｓｅｇ）共電極電圧（Ｖｃｏｍ）及び分段負電圧（−Ｖｓｅｇ）が必要である。よって、表示状態がネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）である時、第一スイッチ３１は第一出力端３０１を液晶正電圧（＋Ｖｌｃｄ）の出力端に接続、第二スイッチ３２は第二出力端３０２を分段負電圧（−Ｖｓｅｇ）の出力端に接続する。駆動電圧発生回路２１が出力した分段正電圧（＋Ｖｓｅｇ）と分段負電圧（−Ｖｓｅｇ）はセグメントドライバ２２で使用され、並びに液晶正電圧（＋Ｖｌｃｄ）共電極電圧（Ｖｃｏｍ）及び分段負電圧（−Ｖｓｅｇ）はコモンドライバ２３に用いられる。その内、分段正電圧（＋Ｖｓｅｇ）と分段負電圧（−Ｖｓｅｇ）はセグメントドライバ２２に使用し、共電極電圧（Ｖｃｏｍ）と液晶正電圧（＋Ｖｌｃｄ）はコモンドライバ２３に用いられる。   When the drive polarity signal (CON) is in the negative frame (Negative Frame) stage, the divided drive signal (SEG) and the common drive signal (COM) power output include a liquid crystal positive voltage (+ Vlcd) and a divided positive voltage (+ Vseg). A common electrode voltage (Vcom) and a partial negative voltage (-Vseg) are required. Therefore, when the display state is a negative period (Negative Frame), the first switch 31 connects the first output terminal 301 to the output terminal of the liquid crystal positive voltage (+ Vlcd), and the second switch 32 separates the second output terminal 302. Connected to the output terminal of the stage negative voltage (-Vseg). The divided positive voltage (+ Vseg) and the divided negative voltage (−Vseg) output from the drive voltage generation circuit 21 are used by the segment driver 22, and the liquid crystal positive voltage (+ Vlcd) common electrode voltage (Vcom) and the divided negative voltage. (−Vseg) is used for the common driver 23. Among them, the divided positive voltage (+ Vseg) and the divided negative voltage (−Vseg) are used for the segment driver 22, and the common electrode voltage (Vcom) and the liquid crystal positive voltage (+ Vlcd) are used for the common driver 23.

本発明は電圧切替え制御回路３０を液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）に切替ええる為、同時間内には液晶正電圧（＋Ｖｌｃｄ）と液晶負電圧（-Ｖｌｃｄ）のどちらか一つしか存在しない。よって液晶ディスプレイドライバの半導体製造工程は、元来の回路設計に基づく元来のＶＬＣＤ-ＧＮＤを選択すればよく、セグメントドライバ２２、コモンドライバ２３の必要電圧を変わりなく提供する。図４に本発明液晶ディスプレイドライバの別の実施例フローチャートを示す。本発明の液晶ディスプレイドライバは、更に保存コンデンサ３３を構成要素に加えることが可能である。保存コンデンサ３３は正電圧端（ＶＰ）と負電圧端（ＶＮ）両端を含み、且つ、電圧切替え制御回路３０の第一出力端３０１と第二出力端３０２をそれぞれ正電圧端（ＶＰ）と負電圧端（ＶＮ）に接続する。   In the present invention, since the voltage switching control circuit 30 is switched between the liquid crystal positive voltage (+ Vlcd) and the liquid crystal negative voltage (−Vlcd), either the liquid crystal positive voltage (+ Vlcd) or the liquid crystal negative voltage (−Vlcd) is used within the same time. There is only one. Thus, the semiconductor manufacturing process of the liquid crystal display driver only needs to select the original VLCD-GND based on the original circuit design, and provides the necessary voltages for the segment driver 22 and the common driver 23 without change. FIG. 4 shows a flowchart of another embodiment of the liquid crystal display driver of the present invention. The liquid crystal display driver of the present invention can further include a storage capacitor 33 as a component. The storage capacitor 33 includes both a positive voltage terminal (VP) and a negative voltage terminal (VN), and the first output terminal 301 and the second output terminal 302 of the voltage switching control circuit 30 are connected to a positive voltage terminal (VP) and a negative voltage terminal, respectively. Connect to the voltage terminal (VN).

第一出力端３０１と第二出力端３０２の電性は保存コンデンサ３３の正電圧端（ＶＰ）及び負電圧端（ＶＮ）に接続する。同様に本実施例を利用した液晶ディスプレイを操作する場合、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）時には液晶負電圧（-Ｖｌｃｄ）だけが使用され、ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）段階では液晶正電圧（＋Ｖｌｃｄ）だけが使用される。即ち液晶負電圧（-Ｖｌｃｄ）と液晶正電圧（＋Ｖｌｃｄ）は同時に存在しない。   The electrical properties of the first output terminal 301 and the second output terminal 302 are connected to the positive voltage terminal (VP) and the negative voltage terminal (VN) of the storage capacitor 33. Similarly, when operating the liquid crystal display using the present embodiment, only the liquid crystal negative voltage (-Vlcd) is used in the positive period (Positive Frame), and only the liquid crystal positive voltage (+ Vlcd) is used in the negative period (Negative Frame) stage. used. That is, the liquid crystal negative voltage (−Vlcd) and the liquid crystal positive voltage (+ Vlcd) do not exist at the same time.

本発明実施時の作動方式であるが、表示状態がポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）段階である場合、第一スイッチ３１は第一出力端３０１を分段正電圧（＋Ｖｓｅｇ）の出力端に接続し、第二スイッチ３２は第二出力端３０２を液晶負電圧（-Ｖｌｃｄ）の出力端に接続する。よって、保存コンデンサ３３の正電圧端（ＶＰ）の電位は分段正電圧（＋Ｖｓｅｇ）となり、負電圧端（ＶＮ）の電位は液晶負電圧（-Ｖｌｃｄ）となる。即ち、ポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）段階において、電圧切替え制御回路３０で起きた分段正電圧（＋Ｖｓｅｇ）と液晶負電圧（-Ｖｌｃｄ）はそれぞれのコモンドライバ２３の正電圧端と負電圧端に出入される。   Although it is an operation system at the time of carrying out the present invention, when the display state is a positive frame (Positive Frame) stage, the first switch 31 connects the first output terminal 301 to the output terminal of the divided positive voltage (+ Vseg), The second switch 32 connects the second output end 302 to the output end of the liquid crystal negative voltage (−Vlcd). Therefore, the potential at the positive voltage terminal (VP) of the storage capacitor 33 is the divided positive voltage (+ Vseg), and the potential at the negative voltage terminal (VN) is the liquid crystal negative voltage (−Vlcd). That is, in the positive frame stage, the divided positive voltage (+ Vseg) and the liquid crystal negative voltage (−Vlcd) generated in the voltage switching control circuit 30 enter and exit the positive voltage terminal and the negative voltage terminal of the common driver 23. Is done.

表示状態がポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）からネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）に転換した場合、制御信号を受けて第一スイッチ３１は分段正電圧（＋Ｖｓｅｇ）の出力端を、第二スイッチ３２は液晶負電圧（-Ｖｌｃｄ）の出力端を切り離した後、第二スイッチ３２は分段負電圧（−Ｖｓｅｇ）の出力端に、第一スイッチ３１は液晶正電圧（＋Ｖｌｃｄ）の出力端に接続する為、保存コンデンサ３３の正電圧端（ＶＰ）は液晶正電圧（＋Ｖｌｃｄ）位置を正確に保持する。   When the display state changes from the positive period (Positive Frame) to the negative period (Negative Frame), the first switch 31 receives the output terminal of the divided positive voltage (+ Vseg) in response to the control signal, and the second switch 32 is the liquid crystal negative. After disconnecting the output terminal of the voltage (−Vlcd), the second switch 32 is connected to the output terminal of the divided negative voltage (−Vseg), and the first switch 31 is connected to the output terminal of the liquid crystal positive voltage (+ Vlcd). The positive voltage terminal (VP) of the storage capacitor 33 accurately holds the liquid crystal positive voltage (+ Vlcd) position.

表示状態がネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）段階にある場合、第一スイッチ３１は第一出力端３０１を液晶正電圧（＋Ｖｌｃｄ）出力端に第二スイッチ３２は第二出力端３０２を分段負電圧（−Ｖｓｅｇ）出力端に接続する。よって、保存コンデンサ３３の正電圧端（ＶＰ）の電位は液晶正電圧（＋Ｖｌｃｄ）、負電圧端（ＶＮ）の電位は分段負電圧（−Ｖｓｅｇ）となる。即ち、ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）段階において、電圧切替え制御回路３０は液晶正電圧（＋Ｖｌｃｄ）と分段負電圧（−Ｖｓｅｇ）をコモンドライバ２３の正電圧端と負電圧端にそれぞれ出入する。   When the display state is in a negative frame (Negative Frame) stage, the first switch 31 sets the first output terminal 301 to the liquid crystal positive voltage (+ Vlcd) output terminal, the second switch 32 sets the second output terminal 302 to the divided negative voltage ( -Vseg) Connect to the output. Therefore, the potential at the positive voltage end (VP) of the storage capacitor 33 is the liquid crystal positive voltage (+ Vlcd), and the potential at the negative voltage end (VN) is the divided negative voltage (−Vseg). In other words, in the negative frame (Negative Frame) stage, the voltage switching control circuit 30 inputs and outputs the liquid crystal positive voltage (+ Vlcd) and the divided negative voltage (−Vseg) to the positive voltage terminal and the negative voltage terminal of the common driver 23, respectively.

表示状態がネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）からポジティブ区間（ＰｏｓｉｔｉｖｅＦｒａｍｅ）に転換すると、制御信号を受けて第一スイッチ３１は液晶正電圧（＋Ｖｌｃｄ）の出力端を第二スイッチ３２は分段負電圧（−Ｖｓｅｇ）の出力端を切り離した後、第二スイッチ３２は液晶負電圧（-Ｖｌｃｄ）の出力端に第一スイッチ３１は分段正電圧（＋Ｖｓｅｇ）の出力端に切替ええて接続する為、保存コンデンサ３３の負電圧端（ＶＮ）は液晶負電圧（-Ｖｌｃｄ）の位置を正確に保持する。   When the display state changes from the negative period (Negative Frame) to the positive period (PositiveFrame), the first switch 31 receives the control signal and the output terminal of the liquid crystal positive voltage (+ Vlcd) is received, and the second switch 32 is the divided negative voltage (− After disconnecting the output terminal of Vseg), the second switch 32 is connected to the output terminal of the negative liquid crystal voltage (−Vlcd), and the first switch 31 is connected to the output terminal of the divided positive voltage (+ Vseg). The negative voltage terminal (VN) 33 accurately holds the position of the liquid crystal negative voltage (−Vlcd).

前記実施例と同様、液晶正電圧（＋Ｖｌｃｄ）液晶負電圧（-Ｖｌｃｄ）は、それぞれネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）とポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）段階で現れ、同時に存在することはなく、よって、駆動電圧発生回路２１出力の駆動電圧＋Ｖｌｃｄと-Ｖｌｃｄも同時に存在することはない。   As in the previous embodiment, the liquid crystal positive voltage (+ Vlcd) and the liquid crystal negative voltage (−Vlcd) appear in the negative period and the positive period, respectively, and do not exist at the same time. The drive voltages + Vlcd and -Vlcd output from the generation circuit 21 do not exist at the same time.

５レベル駆動方法に基づいて運用された従来品液晶ディスプレイドライバのフローチャートである。6 is a flowchart of a conventional liquid crystal display driver operated based on a five-level driving method. 図１に示した液晶ディスプレイドライバの駆動極性信号（ＣＯＮ）の分段駆動信号（ＳＥＧ）と通用駆動信号（ＣＯＭ）の電圧ウェーブ図である。FIG. 2 is a voltage wave diagram of a split drive signal (SEG) and a common drive signal (COM) of a drive polarity signal (CON) of the liquid crystal display driver shown in FIG. ５レベル駆動方法に基づいて運用された本発明液晶ディスプレイドライバのフローチャートである。6 is a flowchart of a liquid crystal display driver of the present invention operated based on a five-level driving method. 本発明液晶ディスプレイドライバの別の実施例フローチャートである。6 is a flowchart of another embodiment of the liquid crystal display driver of the present invention.

符号の説明Explanation of symbols

１１ 駆動電圧発生回路
１２ セグメントドライバ
１３ コモンドライバ
２１ 駆動電圧発生回路
２２ セグメントドライバ
２３ コモンドライバ
３０ 電圧切替え制御回路
３０１ 第一出力端
３０２ 第二出力端
３１ 第一スイッチ
３２ 第二スイッチ
３３ 保存コンデンサ 11 drive voltage generation circuit 12 segment driver 13 common driver 21 drive voltage generation circuit 22 segment driver 23 common driver 30 voltage switching control circuit 301 first output end 302 second output end 31 first switch 32 second switch 33 storage capacitor

Claims (5)

液晶ディスプレイドライバは、次の構成要素（ａ）（ｂ）（ｃ）（ｄ）を含み、
（ａ）駆動電圧発生回路は、これによって液晶正電圧（＋Ｖｌｃｄ）液晶負電圧（-Ｖｌｃｄ）分段正電圧（＋Ｖｓｅｇ）共電極電圧（Ｖｃｏｍ）及び分段負電圧（−Ｖｓｅｇ）を発生させ出力し、
（ｂ）セグメントドライバは、駆動極性信号（ＣＯＮ）によって制御されており、分段正電圧（＋Ｖｓｅｇ）及び分段負電圧（−Ｖｓｅｇ）を受けて分段駆動信号（ＳＥＧ）を出力し、
（ｃ）電圧切替え制御回路は駆動極性信号（ＣＯＮ）によって制御されており、液晶正電圧（＋Ｖｌｃｄ）と分段正電圧（＋Ｖｓｅｇ）及び分段負電圧（−Ｖｓｅｇ）と液晶負電圧（-Ｖｌｃｄ）を受けて、ネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）とポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）状態での駆動極性信号（ＣＯＮ）に対応して制御された液晶正電圧（＋Ｖｌｃｄ）または液晶負電圧（-Ｖｌｃｄ）を、第一出力端と第二出力端から交互に出力し、
（ｄ）コモンドライバは駆動極性信号（ＣＯＮ）によって制御されており、電圧切替え制御回路両出力端から提供された液晶正電圧（＋Ｖｌｃｄ）、液晶負電圧（-Ｖｌｃｄ）及び共電極電圧（Ｖｃｏｍ）を受けて通用駆動信号（ＣＯＭ）を出力することを特徴とする、液晶ディスプレイドライバ。 The liquid crystal display driver includes the following components (a) (b) (c) (d):
(A) The drive voltage generation circuit generates and outputs a liquid crystal positive voltage (+ Vlcd), a liquid crystal negative voltage (-Vlcd), a divided positive voltage (+ Vseg), a common electrode voltage (Vcom), and a divided negative voltage (-Vseg). And
(B) The segment driver is controlled by a drive polarity signal (CON), receives a divided positive voltage (+ Vseg) and a divided negative voltage (−Vseg), and outputs a divided drive signal (SEG).
(C) The voltage switching control circuit is controlled by a drive polarity signal (CON), and a liquid crystal positive voltage (+ Vlcd), a divided positive voltage (+ Vseg), a divided negative voltage (−Vseg), and a liquid crystal negative voltage (−Vlcd). ), The liquid crystal positive voltage (+ Vlcd) or the liquid crystal negative voltage (−Vlcd) controlled according to the drive polarity signal (CON) in the negative period (Negative Frame) and the positive period (Positive Frame) state, Output alternately from the first output end and the second output end,
(D) The common driver is controlled by a drive polarity signal (CON), and a liquid crystal positive voltage (+ Vlcd), a liquid crystal negative voltage (−Vlcd), and a common electrode voltage (Vcom) provided from both output terminals of the voltage switching control circuit. And a general-purpose driving signal (COM) is output. 請求項１記載の液晶ディスプレイドライバにおいて、前記電圧切替え制御回路は、第一スイッチと第二スイッチを含み、その第一スイッチは、第一出力端を液晶正電圧（＋Ｖｌｃｄ）出力端または分段正電圧（＋Ｖｓｅｇ）出力端に接続、またその第二スイッチは液晶負電圧（-Ｖｌｃｄ）出力端または分段負電圧（−Ｖｓｅｇ）出力端に接続することを特徴とする、液晶ディスプレイドライバ。   2. The liquid crystal display driver according to claim 1, wherein the voltage switching control circuit includes a first switch and a second switch, and the first switch has a first output terminal connected to a liquid crystal positive voltage (+ Vlcd) output terminal or a split positive circuit. A liquid crystal display driver connected to a voltage (+ Vseg) output terminal, and a second switch connected to a liquid crystal negative voltage (-Vlcd) output terminal or a divided negative voltage (-Vseg) output terminal. 請求項２記載の液晶ディスプレイドライバにおいて、第一出力端と第二出力端の電性を保存コンデンサの正電圧端（ＶＰ）または負電圧端（ＶＮ）にそれぞれ接続することを特徴とする、液晶ディスプレイドライバ。   3. The liquid crystal display driver according to claim 2, wherein the electrical properties of the first output terminal and the second output terminal are respectively connected to the positive voltage terminal (VP) or the negative voltage terminal (VN) of the storage capacitor. Display driver. 請求項２記載の液晶ディスプレイドライバにおいて、駆動極性信号（ＣＯＮ）はポジティブ区間（Ｐｏｓｉｔｉｖｅ Ｆｒａｍｅ）の理論形態において、第一スイッチは第一出力端を分段正電圧（＋Ｖｓｅｇ）出力端に、電圧切替え制御回路は第二出力端を液晶負電圧（-Ｖｌｃｄ）の出力端に接続することを特徴とする、液晶ディスプレイドライバ。   3. The liquid crystal display driver according to claim 2, wherein the drive polarity signal (CON) is a theoretical form of positive frame (Positive Frame), and the first switch switches the voltage from the first output terminal to the divided positive voltage (+ Vseg) output terminal. The control circuit has a second output terminal connected to an output terminal of a liquid crystal negative voltage (-Vlcd), a liquid crystal display driver. 請求項２記載の液晶ディスプレイドライバにおいて、駆動極性信号（ＣＯＮ）はネガティブ区間（Ｎｅｇａｔｉｖｅ Ｆｒａｍｅ）の理論形態である場合、第一スイッチは第一出力端を液晶正電圧（＋Ｖｌｃｄ）出力端に、第二スイッチは第二出力端を分段負電圧（−Ｖｓｅｇ）の出力端に接続することを特徴とする、液晶ディスプレイドライバ。
3. The liquid crystal display driver according to claim 2, wherein when the drive polarity signal (CON) is a theoretical form of a negative frame (Negative Frame), the first switch has a first output terminal at a liquid crystal positive voltage (+ Vlcd) output terminal. The two switches have a second output terminal connected to an output terminal of a divided negative voltage (-Vseg), a liquid crystal display driver.
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