Display driver circuit, electro-optical device, and display drive method
View Patent ↗The present invention provides a display driver circuit having a simple configuration due to a decrease in the number of voltage levels and capable of preventing deterioration of contrast ratio in display drive by using MLS, an electro-optical device, and a display drive method. First to fourth bits of grayscale data corresponding to a display pattern for three lines are supplied to each ROM. The ROMs decode and output 4MLS operation results for a display pattern defined by the first to fourth bits of the grayscale data and a dummy display-pattern corresponding to the display pattern based on orthogonal functions defined by combinations of a scan pattern and a dummy scan pattern of a virtual electrode based on a field signal.
1. A display driver circuit which drives an electro-optical device having scan electrodes and signal electrodes by using a multi-line selection that selects three scan electrodes simultaneously, the display driver circuit comprising:
first to m-tb (m is a natural number) decoder circuits which are provided for respective bits of each of first to third grayscale data and output decoded output signals based on a field signal and the respective bits of each of the first to third grayscale data, the first to third grayscale data being m-bit data and corresponding to a scan pattern of the three scan electrodes;
a pulse width modulation signal conversion circuit which modulates pulse width of m bits of the decoded output signals output from the first to m-th decoder circuits; and
a signal electrode driver circuit which drives the signal electrode based on signals, pulse width of which is modulated by the pulse width modulation signal conversion circuit,
wherein an i-th (i is a natural number equal to or greater than one and equal to or less than m) decoder circuit outputs one of the decoded output signals corresponding to the field signal, by using a result of a given operation executed on a display pattern and a dummy pattern corresponding to the display pattern, based on an orthogonal function which defines the scan pattern of the three scan electrodes in each field and a scan pattern of a virtual scan electrode corresponding to the scan pattern of the three scan electrodes, the display pattern being corresponding the i-bit data of the first to third grayscale data; and
wherein the signal electrode driver circuit drives the signal electrode by using one of two potential levels based on the signals, pulse width of which is modulated by the pulse width modulation signal conversion circuit.
2. A display driver circuit which drives an electro-optical device having scan electrodes and signal electrodes by using a multi-line selection that selects three scan electrodes simultaneously, the display driver circuit comprising:
a grayscale data conversion circuit which converts m (m is a natural number) bits of first to third grayscale data corresponding to scan pattern of the three scan electrodes into (m+p) bits (p is a natural number) of first to third converted grayscale data, respectively;
first to (m=p)th decoder circuits which are provided for respective bits of each of the first to third converted grayscale data and output decoded output signals based on a field signal end respective bits of each of the first to third converted grayscale data;
a pulse width modulation signal conversion circuit which modulates pulse width of (m+p) bits of the decoded output signals output from the first to (m+p)th decoder circuits; and
a signal electrode driver circuit which drives the signal electrode based on signals, pulse width of which is modulated by the pulse width modulation signal conversion circuit,
wherein a j-th (j is a natural number equal to or greater than one and equal to or less than (m+p)) decoder circuit outputs one of the decoded output signals corresponding to the field signal, by using a result of a given operation executed on a display pattern and a dummy pattern corresponding to the display pattern, based on an orthogonal function which defines the scan pattern of the three scan electrodes in each field and a scan pattern of a virtual scan electrode corresponding to the scan pattern of the three scan electrodes, the display pattern being corresponding to the j-th bit data of the first to third grayscale data; and
wherein the signal electrode driver circuit drives the signal electrode by using one of two potential levels based on the signals, pulse width of which is modulated by the pulse width modulation signal conversion circuit.
3. An electro-optical device which is driven by using a multi-line selection that selects three scan electrodes simultaneously, the electro-optical device comprising:
a pixel defined by one of a plurality of scan electrodes and one of a plurality of signal electrodes intersecting each other;
the display driver circuit as defined by claim 1 which drives the signal electrode; and
a scan driver which drives the scan electrodes.
4. An electro-optical device which is driven by using a multi-line selection that selects three scan electrodes simultaneously, the electro-optical device comprising:
a pixel defined by one of a plurality of scan electrodes and one of a plurality of signal electrodes intersecting each other;
the display driver circuit as defined by claim 2 which drives the signal electrode; and
a scan driver which drives the scan electrodes.
5. An electro-optical device which is driven by using a multi-line selection that selects three scan electrodes simultaneously, the electro-optical device comprising:
a display panel having a pixel defined by one of a plurality of scan electrodes and one of a plurality of signal electrodes intersecting each other;
the display driver circuit as defined by claim 1 which drives the signal electrode; and
a scan driver which drives the scan electrodes.
6. An electro-optical device which is driven by using a multi-line selection that selects three scan electrodes simultaneously, the electro-optical device comprising:
a display panel having a pixel defined by one of a plurality of scan electrodes and one of a plurality of signal electrodes intersecting each other
the display driver circuit as defined by claim 2 which drives the signal electrode; and
a scan driver which drives the scan electrodes.
7. A display drive method of driving an electro-optical device having scan electrodes and signal electrodes by using a multi-line selection that selects three scan electrodes simultaneously, the method comprising:
outputting decoded output signals for respective bits of each of first to third grayscale data, based on a field signal and ani-th data of the first to third grayscale data, the first to third grayscale data being m-bit (m is a natural number and i is a natural number equal to or greater than one and equal to or less than m) data and corresponding to a scan pattern of the three scan electrodes; and
driving the signal electrode by using one of two potential levels based on the signals, pulse width of which is modulated based on the decoded output signals,
wherein the i-th bit data of the decoded output signals is output corresponding to the field signal, by using a result of a given operation executed on a display pattern and a dummy pattern corresponding to the display pattern, based on an orthogonal function which defines the scan pattern of the three scan electrodes in each field and a scan pattern of a virtual scan electrode corresponding to the scan pattern of the three scan electrodes, the display pattern being corresponding to i-th bit data of the first to third grayscale data.
8. A display drive method of driving an electro-optical device having scan electrodes and signal electrodes by using a multi-line selection that selects three scan electrodes simultaneously, the method comprising:
converting m (m is a natural number) bits of first to third grayscale data corresponding to scan pattern of the three scan electrodes into (m+p) bits (p is a natural number) of first to third converted grayscale data, respectively;
outputting decoded output signals for respective bits of each of the first to third converted grayscale data, based on a field signal and a j-th bit data of the first to third converted grayscale data (j is a natural number equal to or greater than one and equal to or less than (m+p)); and
driving the signal electrode by using one of two potential levels based on the signals, pulse width of which is modulated based on the decoded output signals,
wherein j-th bit data of the decoded output signals is output corresponding to the field signal, by using a result of a given operation executed on a display pattern and a dummy pattern corresponding to the display pattern, based on an orthogonal function which defines the scan pattern of the three scan electrodes in each field and a scan pattern of a virtual scan electrode corresponding to the scan pattern of the three scan electrodes, the display pattern being corresponding to j-th bit data of the first to third grayscale data.