Driving circuit for display device and liquid crystal display device
AssigneeKabushiki Kaisha Toshiba
InventorsKazuo Nakamura, Tomonobu Motai, Takashi Nakamura, Masao Karube, Hirotaka Hayashi
Life of this patent
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Abstract
A driving circuit of a display device like liquid crystal display, which is small in circuit size, ensures good quality images, and can freely change the display gradation, is configured to execute digital-analog conversion by reallocating charges between a primary-side capacitor and a secondary-side capacitor and includes a plurality of such capacitors in the primary side or the secondary side to enable both quick conversion and reliable potential output to signal lines. Also in an output circuit, output of signal potentials not affected by fluctuation of properties of TFT and inverters can be realized.
Claims36
A driving circuit of a display device including a digital-analog converter circuit which introduces digital data and outputs an analog video signal, said digital-analog converter circuit comprising:
- a reference voltage selecting circuit which is responsive to each of bit signals of data of a plurality of bits to exclusively select and output one of a plurality of reference voltages;
- a group of input-side capacitor elements connected to said reference voltage selecting circuit and including a plurality of capacitor elements which hold the reference voltage output from said reference voltage selecting circuit;
- an amplifier which amplifies a voltage in accordance with electric charge accumulated to each capacitor element in said group of input-side capacitor elements;
- and
- a connection circuit which supplies electric charge of each capacitor element in said group of input-side capacitor elements to said amplifier selectively in sequence,
- wherein said amplifier includes:
- an output-side capacitor element which holds electric charge distributed from each capacitor element in said group of input-side capacitor elements;
- and
- a buffer amplifier which amplifies a voltage due to the electric charge held on said output-side capacitor element and outputs the amplified voltage as an analog video signal.
A driving circuit of a display device including a digital-analog converter circuit which introduces digital data and outputs an analog video signal, said digital-analog converter circuit comprising:
- a reference voltage selecting circuit which is responsive to each of bit signals of time-serially input data of a plurality of bits to exclusively select and output one of a plurality of reference voltages;
- an input-side capacitor element connected to said reference voltage selecting circuit to hold the reference voltage output from said reference voltage selecting circuit;
- an amplifier which amplifies a voltage in accordance with electric charge accumulated to said input-side capacitor element;
- and
- a connection circuit which supplies electric charge of said input-side capacitor element to said amplifier selectively in sequence;
- wherein said amplifier includes:
- a group of output-side capacitor elements which holds electric charge distributed from said input-side capacitor element, said group of output-side capacitor elements having a plurality of capacitor elements;
- and
- a buffer amplifier which amplifies a voltage due to the electric charge held on each capacitor element of said group of output-side capacitor elements and outputs the amplified voltage as an analog video signal.
A driving circuit of a display device including a digital-analog converter circuit which introduces digital data and outputs an analog video signal, said digital analog converter circuit comprising:
- a reference voltage selecting circuit which is responsive to each of bit signals of time-serially input data of a plurality of bits to exclusively select and output one of a plurality of reference voltages;
- a group of input-side capacitor elements connected to said reference voltage selecting circuit and including a plurality of capacitor elements which hold the reference voltage output from said reference voltage selecting circuit;
- an amplifier which amplifies a voltage in accordance with electric charge accumulated to each capacitor element in said group of input-side capacitor elements;
- and
- a connection circuit which supplies electric charge of each capacitor element in said group of input-side capacitor elements to said amplifier selectively in sequence;
- wherein said amplifier includes:
- a group of output-side capacitor elements which holds electric distributed from each capacitor element in said group of input-side capacitor elements, said group of output-side capacitor elements having a plurality of capacitor elements;
- and
- a buffer amplifier which amplifies a voltage due to the electric charge held on each capacitor element of said group of output-side capacitor elements and outputs the amplified voltage as an analog video signal.
A driving circuit of a display device having a plurality of signal lines and scanning lines extending to intersect at right angles, and pixel switching elements provided at crossing points of said signal lines and said scanning lines, respectively, to display gradient representation of 2m (m is a plural number) based on data with m bits, comprising:
- a data distributing circuit supplied with said data of m bits;
- a data latch circuit sequentially storing said data of m bits and outputting them at a predetermined timing;
- a gamma correction circuit which store the output from said data latch circuit and outputs it at a predetermined timing;
- and
- a digital-analog converter circuit which stores the output from said gamma correction circuit and outputs it at a predetermined timing,
- wherein said digital-analog converter circuit includes:
- a reference voltage selecting circuit which is responsive to each of bit signals of data of a plurality of bits to exclusively select and output one of a plurality of reference voltages;
- a group of input-side capacitor elements connected to said reference voltage selecting circuit and including a plurality of capacitor elements which hold the reference voltage output from said reference voltage selecting circuit;
- an amplifier which amplifies a voltage in accordance with electric charge accumulated to each capacitor element in said group of input-side capacitor elements;
- and
- a connection circuit which supplies electric charge of each capacitor element in said group of input-side capacitor elements to said amplifier selectively in sequence;
- wherein said amplifier includes:
- an output-side capacitor element which holds electric charge distributed from each capacitor element in said group of input-side capacitor elements;
- and
- a buffer amplifier which amplifies a voltage due to the electric charge held on said output-side capacitor element and outputs the amplified voltage as an analog video signal.
Dependencies are inferred from the claim text.