Drive circuit
First Claim
1. A drive circuit for outputting a drive waveform so as to drive a display element in accordance with grayscale information, the drive waveform being controlled by (i) a plural-stepped voltage amplitude modulation and (ii) a pulse width modulation which is settable for each voltage amplitude of the plural-stepped voltage amplitude modulation, said drive circuit comprising output control means for controlling the drive waveform, at a time of modulating arbitrary grayscale information, said output control means (A) latching a signal indicating a pulse width corresponding to a maximum voltage amplitude to be outputted so as to control a pulse width of the maximum voltage amplitude, and (B) outputting a maximum pulse width for a voltage amplitude smaller than the maximum voltage amplitude.
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Accused Products
Abstract
A drive circuit of the present invention is a drive circuit for driving a display element in accordance with grayscale information, which circuit outputs a drive waveform controlled through (i) plural-stepped voltage amplitude modulation and (ii) a pulse width modulation which is settable for each voltage amplitude of the plural-stepped voltage amplitude modulation, the drive circuit including an output control section for (A) latching a pulse width corresponding to a maximum voltage amplitude, according to the grayscale information, which amplitude is one of plural steps of amplitudes of the drive waveform, and which amplitude is to be outputted, so as to control a pulse width of the maximum voltage amplitude, and (B) outputting a maximum pulse width for a voltage amplitude smaller than the maximum voltage amplitude. With this drive circuit, it is possible to realize a drive circuit, whose circuit scale is smaller, for driving a display device including luminescent elements arranged in a matrix manner, the drive circuit generating a drive signal having been controlled by a voltage amplitude modulation (AM) and a pulse width modulation (PWM)
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Citations
6 Claims
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1. A drive circuit for outputting a drive waveform so as to drive a display element in accordance with grayscale information, the drive waveform being controlled by (i) a plural-stepped voltage amplitude modulation and (ii) a pulse width modulation which is settable for each voltage amplitude of the plural-stepped voltage amplitude modulation,
said drive circuit comprising output control means for controlling the drive waveform, at a time of modulating arbitrary grayscale information, said output control means (A) latching a signal indicating a pulse width corresponding to a maximum voltage amplitude to be outputted so as to control a pulse width of the maximum voltage amplitude, and (B) outputting a maximum pulse width for a voltage amplitude smaller than the maximum voltage amplitude.
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2. A drive circuit for outputting a drive waveform so as to drive a display element in accordance with grayscale information, the drive waveform being controlled by (i) a plural-stepped voltage amplitude modulation and (ii) a pulse width modulation which is settable for each voltage amplitude of the plural-stepped voltage amplitude modulation, said drive circuit comprising:
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voltage value data latching means, at a time of modulating arbitrary grayscale information, for latching first data indicating a maximum voltage amplitude to be outputted;
PWM data latching means, at the time of modulating arbitrary grayscale information, for latching second data indicating a pulse width of the maximum voltage amplitude;
output-range signal generating means, at the time of modulating arbitrary grayscale information, for generating and outputting an output-range signal in accordance with a maximum pulse width of each voltage amplitude; and
one or more control means, at the time of modulating arbitrary grayscale information, for (a) outputting a pulse width of the maximum voltage amplitude according to the first data and the second data, and (b) outputting a maximum pulse width according to the output-range signal, when a voltage amplitude is smaller than the maximum voltage amplitude. - View Dependent Claims (3, 4, 5, 6)
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Specification