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US 2006/0214890 A1Published application
Display apparatus and drive method therefor
AssigneeCasio Computer Co., Ltd.
InventorsMorio Morishige, Tomoyuki Shirasaki, Hiroyasu Yamada
Life of this patent
Estimating the term…
Abstract
Disclosed is a high-definition display apparatus which allows a write current having an adequate value to flow. The display apparatus comprises a plurality of signal lines, a plurality of optical elements which presents display as a drive current equal in value to a write current flowing in the signal lines flows, and a current control driver which is connected to one ends of the signal lines, reduces the current value of a gradation signal by a current reduction ratio and lets the write current flow in the signal lines.
Claims28
A display apparatus comprising:
- a plurality of pixels which are respectively arranged at intersections of a plurality of scan lines and a plurality of signal lines in a display areas and each of which comprises:
- (i) an optical element which performs an optical operation based on a current value of a drive current flowing therethrough, and (ii) a pixel circuit which supplies said drive current to said optical element;
- and
- a current control driver which is arranged in an area other than said display area, which is connected to each of said signal lines, and which reduces a current value of a gradation signal by a predetermined current reduction ratio so as to supply said drive current to said optical elements;
- wherein the current control driver comprises:
- a plurality of current mirror circuits corresponding respectively to the signal lines;
- a plurality of first switch circuits which are provided between the current mirror circuits and the signal lines corresponding thereto, respectively, and which are adapted to have a sync-signal input thereto so that the current reduced by the mirror circuits flows in the signal lines;
- a plurality of second switch circuits which supply corresponding gradation signals to the current mirror circuits;
- and
- a shift register which outputs a signal to the second switch circuits to select the second switch circuits sequentially.
7 more elements
(canceled)
6-7. (canceled)
A display apparatus comprising:
- a plurality of signal lines;
- a plurality of pixels, each of which is connected to one of the plurality of signal lines and comprises an optical element which performs an optical operation based on a value of a drive current flowing therethrough;
- and
- a current control driver which is connected to other ends an end of each of said plurality of signal lines and which reduces a current value of a gradation signal by a predetermined current reduction ratio such that the reduced write current flows in said signal lines;
- wherein the current control driver comprises:
- a plurality of current mirror circuits corresponding respectively to the signal lines;
- a plurality of first switch circuits which are provided between the current mirror circuits and the signal lines corresponding thereto, respectively, and which are adapted to have a sync-signal input thereto so that the reduced write current flows in the signal lines;
- a plurality of second switch circuits which supply corresponding gradation signals to the current mirror circuits;
- and
- a shift resister which outputs a signal to the second switch circuits to select the second switch circuits sequentially.
7 more elements
A display apparatus comprising:
- a optical element which has a pair of electrodes and performs an optical operation in accordance with a current flowing between said pair of electrodes;
- a first switching element including a control terminal and a current path which has a first end that is connected to a first one of said pair of electrodes of said optical element so that a current with a value corresponding to a voltage between said control terminal and said first end of said current path flows in said current path;
- a power supply line which is connected to a second end of said current path of said first switching element and on which a power supply signal for allowing a drive current to flow in said optical element is output;
- a scan line on which a scan signal for selecting said optical element is output;
- a signal line in which a write current flows from said power supply line via said current path of said first switching element;
- a second switching element which controls a voltage to be applied to said control terminal of said first switching element in accordance with said scan signal on said scan line;
- a third switching element which controls a current flowing in said signal line in accordance with said scan signal in said scan line;
- a capacitor which holds a voltage between said control terminal of said first switching element and said first end of said current path of said first switching element;
- and
- a current control driver which allows said write current, which is obtained by reducing a current value of a gradation signal by a predetermined current reduction ratio, to flow in said signal line;
- wherein the current control driver comprises:
- a plurality of current mirror circuits corresponding respectively to the signal lines;
- a plurality of first switch circuits which are provided between the current mirror circuits and the signal lines corresponding thereto, respectively, and which are adapted to have a sync-signal input thereto so that the write current flows in the signal lines;
- a plurality of second switch circuits which supply corresponding gradation signals to the current mirror circuits;
- and
- a shift register which outputs a signal to the second switch circuits to select the second switch circuits sequentially.
13 more elements
A drive method for display apparatus comprising:
- providing a plurality of pixels, a plurality of signal lines and a current control driver comprising:
- (i) a plurality of current mirror circuits which correspond respectively to the signal lines and each of which reduces a current value of an input gradation signal by a predetermined current reduction ratio;
- (ii) a plurality of first switch circuits which are provided between the current mirror circuits and the signal lines corresponding thereto, respectively, and which are adapted to have a sync-signal input thereto so that the current reduced in the mirror circuits flows in the corresponding signal lines;
- (iii) a plurality of second switch circuits which supply corresponding gradation signals to the current mirror circuits;
- and (iv) a shift register which outputs a signal to the second switch circuits to select the second switch circuits sequentially
- causing a write current obtained by reducing the current value of the gradation signal by the predetermined current reduction ratio to flow to the plurality of pixels via the plurality of signal lines;
- and
- causing a drive current equal in value to said write current to flow in optical elements of said plurality of pixels.
5 more elements
Dependencies are inferred from the claim text.