Electroluminescent display device and a driving method thereof
First Claim
1. An electroluminescent display apparatus comprising:
- a plurality of electroluminescent elements for emitting light in response to a voltage or a current applied, each of the electroluminescent elements including a first electrode, an electroluminescent layer in contact with the first electrode, and a second electrode in contact with the electroluminescent layer;
a plurality of first switching circuits respectively connected to the first electrodes of the electroluminescent elements, for applying a first drive voltage to electroluminescent elements selected in each of address periods, in each of light emission setting periods, each of the first switching circuits having a smaller resistance ratio than that of each of the plurality of electroluminescent elements, during each of the light emission setting periods; and
a second switching circuit connected to each of the second electrodes of the electroluminescent elements, for applying a second drive voltage different from the first drive voltage, to all the electroluminescent elements, in each of the light emission setting periods.
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Accused Products
Abstract
A controller stores image signals Sp represented as binary values for every unit of frame. The controller divides one frame into a plurality of sub-frames representing an image by image data of two gradation levels, in accordance with respective figures of the stored image signals Sp for one frame. The image data of two gradation levels for each of the sub-frames is written into capacitors Cp from a drain driver, for every row. When the image data is "1", a drive transistor is turned on. A common driver applies a voltage of a predetermined level for every sub-frame, to control the voltage applied between electrodes of an organic EL element. As a result, the organic EL element emit light with brightness which differs between sub-frames. Images of the sub-frames are visually synthesized, so that gradation is expressed in one frame.
957 Citations
25 Claims
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1. An electroluminescent display apparatus comprising:
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a plurality of electroluminescent elements for emitting light in response to a voltage or a current applied, each of the electroluminescent elements including a first electrode, an electroluminescent layer in contact with the first electrode, and a second electrode in contact with the electroluminescent layer; a plurality of first switching circuits respectively connected to the first electrodes of the electroluminescent elements, for applying a first drive voltage to electroluminescent elements selected in each of address periods, in each of light emission setting periods, each of the first switching circuits having a smaller resistance ratio than that of each of the plurality of electroluminescent elements, during each of the light emission setting periods; and a second switching circuit connected to each of the second electrodes of the electroluminescent elements, for applying a second drive voltage different from the first drive voltage, to all the electroluminescent elements, in each of the light emission setting periods. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An electroluminescent display apparatus comprising:
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first and second groups each consisting of electroluminescent elements for emitting light in response to a voltage or a current applied, each of the electroluminescent elements including a first electrode, an electroluminescent layer in contact with the first electrode, and a second electrode in contact with the electroluminescent layer; a plurality of first switching circuits respectively connected to the first electrodes of the electroluminescent elements, for applying a first drive voltage to electroluminescent elements selected in each of address periods, in each of light emission setting periods, each of the first switching circuits having a smaller resistance ratio than that of each of the plurality of electroluminescent elements, during each of the light emission setting periods; and a second switching circuit connected to each of the second electrodes of the electroluminescent elements, for applying a second drive voltage different from the first drive voltage, to the first group of the electroluminescent elements, and subsequently, to the second group of the electroluminescent elements, in each of the light emission setting periods. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. A driving method of an electroluminescent display apparatus comprising:
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a step of preparing a plurality of electroluminescent elements for emitting light in response to a voltage or a current applied, each of the electroluminescent elements including a first electrode, an electroluminescent layer in contact with the first electrode, and a second electrode in contact with the electroluminescent layer; a first drive voltage supply step of supplying a first drive voltage to the first electrodes of the electroluminescent elements which are addressed, in each of light emission setting periods, in a frame period for forming an image by synthesizing a plurality of sub-frames each consisting of an address period for addressing the plurality of electroluminescent elements, and one of the light emission setting periods for making the addressed electroluminescent elements emit light; and a second drive voltage supply step of supplying a second drive voltage different from the first drive voltage, to the second electrodes of all the electroluminescent elements, in each of the light emission setting periods. - View Dependent Claims (21, 22)
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23. A driving method of an electroluminescent display apparatus, comprising:
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(A) a step of preparing first and second groups each consisting of electroluminescent elements for emitting light in response to a voltage or a current applied, each of the electroluminescent elements including a first electrode, an electroluminescent layer in contact with the first electrode, and a second electrode in contact with the electroluminescent layer; (B-1) a first electroluminescent element group address step of addressing the first group of the electroluminescent elements; (B-2) a first electroluminescent element group light emission step of applying a common voltage to the electroluminescent elements addressed by the first electroluminescent element group address step; (B-3) a second electroluminescent element group address step of addressing the second group of the electroluminescent elements, after the first electroluminescent element group address step; and (B-4) a second electroluminescent element group light emission step of applying a common voltage to the electroluminescent elements addressed by the second electroluminescent element group address step, wherein the first electroluminescent element group address step, the first electroluminescent element group light emission step, the second electroluminescent element group address step, and the second electroluminescent element group light emission step are carried out, in one of sub-frames of a frame period for forming an image by synthesizing the sub-frames each consisting of an address period for sequentially addressing the first and second groups, and a light emission setting period for making those of the electroluminescent elements of the first and second groups, which are addressed in the address period, emit light. - View Dependent Claims (24, 25)
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Specification