Claims
- 1. A circuit for use with a liquid crystal display (LCD) wherein said LCD display contains a matrix of picture elements (pixel) arranged in a first number of pixel columns and second number of rows on a substrate, said circuit comprising:
- a plurality of row select driver circuits corresponding to said number of pixel rows for electrically energizing said pixel rows, said row select driver circuits being deposited on the LCD display substrate, wherein an output of each of said row select driver circuits is electrically connected to a corresponding pixel row and to a succeeding row select driver circuit as an activating input; and
- switching means external to the LCD display and having leads electrically connected to said row select driver circuits for providing:
- first set of three clock signals S1,o, S2,o, S3,o to all odd-numbered rows having a period twice as long as the horizontal scanning time of the display,
- second set of three clock signals S1,e, S2,e, S3,e to all even-numbered rows lagging said first set of three clock signals respectively by said horizontal scanning time,
- a seventh clock signal S4 having a period equal to the horizontal scanning time of the display,
- a shift-in clock signal SDIN coupled to only the input terminal of first row select driver circuit,
- said first set of three clock signals, second set of three clock signals, said seventh clock signal and said shift-in clock signals causing an output signal from each row select driver circuit such that each pixel row is sequentially energized.
- 2. The circuit of claim 1, wherein the leads from the switching means is less than the number of pixel rows.
- 3. The circuit of claim 1 wherein each of said row select driver circuits includes a plurality of thin-film transistors interconnected to cause sequential activation of each pixel row.
- 4. The circuit of claim 3 further including:
- a first row select driver circuit stage activating a first pixel row for a first predetermined period of time; and
- a second adjacent row select driver circuit stage activating a subsequent pixel row for a second predetermined period of time such that a longer row select time is provided for each row to charge or discharge the pixels of the corresponding pixel row.
- 5. The circuit of claim 1 wherein the substrate is glass.
- 6. The circuit of claim 1 wherein:
- the clock signal S2,o lags but overlaps partially with and has a pulsewidth wider than the clock signal S1,o, and
- the clock signal S3,o lags but overlaps partially with and has a pulsewidth wider than the clock signal S2,o.
- 7. The circuit of claim 1 wherein the output signal from each row select driver circuit energizes a corresponding pixel row and acts as a shift signal to the succeeding row select driver circuit.
- 8. The circuit of claim 7 wherein each row select driver circuit includes:
- a transistor M1 and a transistor M2 connected in series between a positive power supply and a first negative power supply VSS1 with the gate of M1 connected to said S1,o clock signal for odd-numbered stages and to said S1,e clock signal for even-numbered stages, and with the gate of M2 connected to an input terminal;
- a transistor M5 and a transistor M4 connected in series between said VSS1 and said clock signal S2,o for odd-numbered stages and to said S2,e signal clock for even-numbered stages, with:
- the gate of M4 connected to said input terminal,
- the gate of M5 connected to the common node between M1 and M2, and to the drain and gate of a transistor M3 with the source connected to VSS1;
- a transistor M7 and a transistor M6 connected in series between a second negative supply terminal VSS and said clock signal S3,o for odd-numbered stages or clock signal S3,e for even-numbered stages, with:
- the gate of M7 connected to the common node between M1 and M2,
- the gate of M6 connected to the common node between M4 and M5, and
- the common node between M7 and M6 connected to said row output and the input terminal of the next stage;
- a transistor M11 and a transistor M10 connected in series between said first negative supply terminal VSS1 and said clock signal S1,o for odd-numbered stages and said clock signal S1,e for even-numbered stages having:
- the gate of M11 connected to said input signal,
- the common node of M11 and M10 connected to the gate of a transistor M8 with drain and source connected in parallel with the drain and source of the transistor M7;
- a transistor M9 connected between the gate of M10 and the row output of succeeding stage, and having the gate of M9 connected to the clock signal S4.
- 9. A circuit of claim 8, wherein the first negative power supply terminal VSS1 and the second negative power terminal supply VSS are connected.
- 10. The circuit of claim 7, wherein each row select driver circuit includes:
- a transistor M2 and a transistor M1 connected in series between a first negative power supply VSS1 and said S1,o clock signal for odd-numbered stages and S1,e clock signal for even-numbered stages, with the gate of M1 connected to the drain of M1 and with the gate of M2 connected to an input terminal;
- a transistor M5 and a transistor M4 connected in series between said VSS1 and said clock signal S2,o for odd-numbered stages and to said S2,e clock signal for even-numbered stages, with:
- the gate of M4 connected to said input terminal,
- the gate of M5 connected to the common node between M1 and M2, and to the drain and gate of a transistor M3 with the source connected to VSS1;
- a transistor M7 and a transistor M6 connected in series between a second negative supply terminal VSS and said clock signal S3,o for odd-numbered stages or clock signal S3,e for even-numbered stages, with:
- the gate of M7 connected to the common node between M1 and M2,
- the gate of M6 connected to the common node between M4 and M5, and
- the common node between M7 and M6 connected to said row output and the input terminal of the next stage;
- a transistor M11 and a transistor M10 connected in series between said first negative supply terminal VSS1 and said clock signal S1,o for odd-numbered stages and said clock signal S1,e for even-numbered stages having:
- the gate of M11 connected to said input signal,
- the common node of M11 and M10 connected to the gate of a transistor M8 with drain and source connected in parallel with the drain and source of the transistor M7;
- a transistor M9 connected between the gate of M10 and the row output of succeeding stage, and having the gate of M9 connected to the clock signal S4.
- 11. A circuit of claim 10, wherein the first negative power supply terminal VSS1 and the second negative power terminal supply VSS are connected.
Parent Case Info
This application is a continuation-in-part, of application Ser. No. 08/287,499, filed Aug. 8, 1994, now abandoned.
US Referenced Citations (5)
Continuation in Parts (1)
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Number |
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287499 |
Aug 1994 |
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