Liquid-crystal display system having a driver circuit capable of multi-color display

An X driver circuit into which display data to be displayed on a liquid-crystal panel is supplied, and which generates and transmits any of m liquid-crystal driving voltages having m different voltage levels corresponding to said display data to each data line of the liquid crystal panel, said X driver circuit comprising:

• a voltage divider circuit provided for each data line, by which n voltages externally supplied are divided into m voltages having m different voltage levels (n<m, n and m are integers larger than 1) corresponding to said display data;
• wherein said voltage divider circuit includes:
• a first selector circuit which is supplied with the n voltages of n different voltage levels, and which selects and transmits two of the supplied n voltages,
• a first control circuit which controls said first selector circuit in accordance with said display data so as to select the two voltages,
• a resistance circuit which is supplied with the selected voltages at both of its ends, in which a plurality of resistor elements are connected in series, and which transmits either of a plurality of divisional voltages produced from the selected voltages, and the supplied voltages, and
• a second control circuit which controls said second selector circuit under a voltage selection command externally supplied, so as to select the voltage to-be-transmitted from either of said supplied voltages and said plurality of divisional voltages corresponding to said display data.

A liquid-crystal display system for tonal displays, including:

• a liquid-crystal panel having a plurality of scanning lines and a plurality of data lines;
• a Y driver circuit by which one of the plurality of scanning lines to have a voltage applied thereto is selected, and which transmits the voltage to the selected one of the plurality of scanning lines;
• an X driver circuit which is supplied with display data, and which transmits a voltage corresponding to the display data to each of the plurality of data lines;
• a power source, which supplies voltages to the Y driver circuit and the X driver circuit, the supply voltages of the X driver circuit being n voltages having different n voltage levels;
• a control signal generator circuit for generating a time signal which divides one horizontal scanning cycle into a first period and a subsequent second period;
• wherein said X driver circuit includes a voltage divider circuit which generates m voltages having m different voltage levels from said n voltages of n different voltage levels supplied from said power source (n<m, wherein n and m are integers greater than 2) and outputs a voltage selected from said m voltages;
• and
• a control circuit, supplied with said time signal and a signal corresponding to said display data, which controls said voltage divider circuit so that a first voltage is selected from said m voltages in said first period, and a second voltage (may be) is selected in said second period from said m voltages, in response to said time signal and said signal corresponding to said display data, in a manner that a time constant, when said first voltage is output to the data lines, is smaller than a time constant when said second voltage is output to the data lines, said second voltage corresponding to said display data;
• wherein said X driver circuit outputs said first voltage and said second voltage, as selected, to each of the data lines in said first period and said second period, respectively.

An X driver circuit which is used for a liquid-crystal display system having a liquid crystal panel and a power source for the liquid-crystal display, and which generates and outputs from a plurality of voltages output from said power source for the liquid-crystal display a display voltage corresponding to display data supplied from an external system via a plurality of data lines comprising:

• a voltage divider circuit which is supplied with n voltages of n different voltage levels, and generates m voltages of m different voltage levels, from said n voltages (n<m, wherein n and m are integers greater than 2), and outputs a selected one of the m voltages;
• and
• a control circuit which is externally supplied with a time signal to divide a horizontal scanning cycle into a first period and a subsequent second period, and controls said voltage divider circuit so that a first voltage is selected from said m voltages in said first period, and a second voltage is selected in said second period from said m voltages, in response to said time signal and said signal corresponding to said display data, in a manner that a time constant when said first voltage is output to said liquid-crystal panel is smaller than a time constant when said second voltage is output to said liquid-crystal panel, said second voltage corresponding to said display data;
• wherein said circuit divider circuit outputs said first and second voltages as selected, in said first and second period to said liquid-crystal panel, respectively.

A liquid-crystal display system for tonal display, including:

• a liquid crystal panel having a plurality of scanning lines and a plurality of data lines;
• a Y driver circuit by which one of the plurality of scanning lines to have a voltage applied thereto is selected, and which transmits the voltage to the selected one of the plurality of scanning lines;
• an X driver circuit which is supplied with display data, and which transmits a voltage corresponding to the display data to each of the plurality of data lines;
• and
• a power source, which supplies voltages to the Y driver circuit and the X driver circuit, the supplied voltages of the X driver circuit being n voltages having n different voltage levels,
• said X driver circuit comprising:
• a plurality of voltage divider circuits which generate m voltages having m different voltage levels from said n voltages supplied from said power source for the liquid-crystal display system (n<m, wherein n and m are integers greater than 2), and outputs one of the m voltages,
• a plurality of control circuits which divide a horizontal scanning cycle into a second period and a preceding first period and control said voltage divider circuits to select a second voltage corresponding to said display data from said m voltages and selecting a first voltage in a manner that an output impedance of said voltage divider circuit is smaller in said first period than an output impedance in said second period,
• wherein each of said voltage divider circuits outputs selected voltages to each of the data lines in said first period and said second period respectively.

An X driver circuit which is used for a liquid-crystal display system including a liquid crystal panel having a plurality of scanning lines and a plurality of data lines, which generates and outputs a display voltage from a plurality of given voltages corresponding to display data supplied from an external system, comprising:

• a plurality of voltage divider circuits which are supplied with n voltages of n different voltage levels and generate m voltages of m different voltage levels, from said n voltages (n<m, wherein n and m are integers greater than 2), and outputs selected one of the voltages;
• and
• a plurality of control circuits which divide a horizontal scanning cycle into a second period and a preceding first period, and gives a command to said voltage divider circuits to select a second voltage corresponding to said display data from said m voltages in said second period and selects a first voltage in said first period such that an output impedance of said voltage divider circuit smaller in said first period compared to that in said second period;
• wherein each of said voltage divider circuits outputs said first and second voltages as selected, in said first and second period to said data lines respectively.