Drive method of el display apparatus
View Patent ↗A drive method of an EL display apparatus that includes a switching element that turns on and off a current path between a driver transistor and an EL element. The drive method aggregates image data input to the EL display apparatus, and determines a period to turn off the switching element according to an amount of the aggregate data. With the method, suppression of peak current and expansion of contrast and so on is realized.
1. A drive method of an EL display apparatus that comprises a display screen in which a plurality of pixels each of which includes an EL element are formed in a matrix and a switching element which turns on/off a current that flows in the EL element, the drive method comprising:
weighting image data with respect to a color of respective of the plurality of pixels, said image data generating a signal which is to be impressed to the respective pixels of the EL display apparatus,
aggregating said weighted image data, and
when results of said aggregating of said weighted image data are larger than a predetermined value,
suppressing an amount of current that flows in the EL element by shortening a time period to pass the current during one frame period by controlling said switching element, displaying a non-display area on the display screen of the EL display apparatus, and shifting the non-display area on the display screen synchronizing with said one frame period.
2. An EL display apparatus including a display screen in which a plurality of pixels each of which includes an EL element are formed in a matrix, the EL display apparatus comprising:
a switching element which turns on/off a current that flows in the EL element;
a gate driver circuit that drives a gate signal line selecting a line of the pixels;
an aggregation circuit configured to weight image data with respect to color of respective of the plurality of pixels, said image data generating a signal which is to be impressed to the respective pixels of the EL display apparatus, and to aggregate the weighted image data; and
a control circuit that controls a timing or a period to generate a start pulse signal for the gate driver circuit based on the aggregated image data, wherein
the gate driver circuit drives the gate signal line according to the start pulse signal, generates a non-display area on the display screen by controlling said switching element, and shifts the non-display area in a scanning direction of the gate driver circuit.
3. The drive method of an EL display apparatus according to claim 1 , wherein:
said EL display apparatus comprises a gate driver circuit that drives a gate signal line selecting a line of the pixels,
the non-display area is generated in a belt-like form on the display screen of the EL display apparatus by the gate driving circuit driving the gate signal line; and
the non-display area is shifted scanning direction of the gate driver circuit.
4. The drive method of an EL display apparatus according to claim 1 , further comprising:
detecting brightness of outside the EL display apparatus;
generating a belt-like non-display area and a belt-like display area; and
changing or adjusting a ratio of the belt-like non-display area and the belt-like display area according to an output value obtained by the detecting.
5. The EL display apparatus according to claim 2 , further comprising:
a selection circuit formed on a substrate on which the EL elements are formed; and
a source driver circuit, wherein
the source driver circuit outputs a video signal of a first color or a video signal of a second color from a signal output terminal,
the substrate includes source signal lines to supply the video signals of the source driver circuit to the EL elements,
the selection circuit includes an input terminal to connect to the signal output terminal of the source driver circuit and a selection output terminal to connect to the source signal line,
the selection circuit includes a plurality of combinations of one output terminal and a plurality of selection output terminals configured to connect to the one output terminal, and
the selection circuit applies a video signal of the source driver circuit input to the input terminal of the selection circuit to the source signal line connected to the one or plural of selection output terminals that are selected from the plurality of the selection output terminals.
6. The EL display apparatus according to claim 2 , further comprising
a source driver circuit that applies a gradation signal to the EL elements, wherein
the source driver circuit includes a voltage output circuit and a current output circuit.
7. The EL display apparatus according to claim 2 , wherein
brightness of the display screen is controlled by varying a ratio of the non-display area to the display screen.
8. The EL display apparatus according to claim 2 , wherein
the shifting the non-display area in the display screen is performed synchronizing with one flame period.
9. The EL display apparatus according to claim 2 , wherein
in the display screen, the plurality of pixels having a plurality of colors are formed in a matrix, and
an area of an element of one color of the plurality of colors is different from an area of an element of the other colors.
10. The EL display apparatus according to claim 2 , wherein the non-display area is divided into a plurality of parts.
11. The drive method of an EL display apparatus according to claim 1 , wherein: a driver transistor for supplying current to said EL element is formed in said pixel of said EL display apparatus, and
said driver transistor is a P-channel transistor.
12. The drive method of an EL display apparatus according to claim 1 ,
wherein, said EL display apparatus further comprises;
a source driver circuit that applies an image signal and,
a switch circuit arranged between an output terminal of said source driver circuit and source signal lines which said pixel is connected with, and
wherein, said switch circuit impresses image signal which is output from said output terminal of said source driver circuit to selected source signal line.
13. The EL display apparatus according to claim 2 , wherein: a driver transistor for supplying current to said EL element is formed in said pixel of said EL display apparatus, and
said driver transistor is a P-channel transistor.
14. The EL display apparatus according to claim 2 , further comprising:
a source driver circuit that applies an image signal and,
a switch circuit arranged between an output terminal of said source driver circuit and source signal lines which said pixel is connected with, and
wherein, said switch circuit impresses image signal which is output from said output terminal of said source driver circuit to selected source signal line.