Plasma display apparatus with increased peak luminance
View Patent ↗A PDP apparatus, the peak luminance of which has been improved with little modification of the existing circuit structure, has been disclosed, in which a thinning process that shortens an address period by hiding part of display lines in a fixed subfield of a low luminance is performed, the saved time is increased by an amount corresponding to that from which the luminance weight (the number of sustain discharge pulses, that is, the length of the sustain discharge period) of the thinned subfield of a low luminance is subtracted, and the remaining time is allocated at the ratio of the luminance weights on completion of the first step in each subfield.
1. A plasma display apparatus configured to perform a gray level display using a subfield method, each subfield of a display field comprising at least an address period in which a cell to be lit is selected and a sustain discharge period in which the selected cell is lit, said apparatus comprising:
a display line number change circuit that changes a number of display lines to be displayed in predetermined subfields at a low luminance display side; and
a luminance compensation circuit that increases a number of sustain discharge pulses in the subfields in which the number of lines to be displayed has been changed, so as to compensate for the luminance decrease due to the change of the number of lines displayed.
2. The plasma display apparatus as set forth in claim 1 , further comprising:
an average luminance detecting circuit that detects the average luminance of an input image signal; and
a display line number control circuit that controls whether or not to activate the display line number change circuit and the luminance compensation circuit based on the average luminance.
3. The plasma display apparatus as set forth in claim 1 , further comprising:
a sustain discharge pulse number change circuit that increases the number of sustain discharge pulses of each subfield by allocating the time saved by changing the number of lines to be displayed by the display line number change circuit minus the time used by the luminance compensation circuit, according to a ratio of luminance of each subfield.
4. A method of driving a plasma display apparatus configured to perform a gray level display using a subfield method, each subfield of a display field comprising at least an address period in which a cell to be lit is selected and a sustain discharge period in which the selected cell is lit, said method comprising:
changing a number of display lines to be displayed in predetermined subfields at a low luminance display side; and
increasing a number of sustain discharge pulses in the subfields in which the number of lines to be displayed has been changed, so as to compensate for the luminance decrease due to the change of the number of lines displayed.
5. The method of driving a plasma display apparatus as set forth in claim 4 , further comprising:
detecting the average luminance of an input image signal; and
determining whether or not to change the number of lines to be displayed based on the detected average luminance.
6. The method of driving a plasma display apparatus as set forth in claim 4 , further comprising:
increasing the number of sustain discharge pulses of each subfield by using the remaining time, which is the time saved by changing the number of lines to be displayed by the display line number change circuit minus that used by the luminance compensation circuit, according to a ratio of luminance of each subfield.