Current mirroring circuit, panel driving apparatus and OLED driver
AssigneeSilicon Works Co., Ltd.
InventorsDong Hyun Hwang, Se Won Lee
Life of this patent
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Abstract
The present invention provides a technology of simultaneously sensing characteristics of a plurality of OLED pixels. Further, a current mirroring circuit for sensing characteristics of OLED pixels can be applied to fields other than sensing characteristics of OLED pixels, and the current mirroring technology can output sensing currents having a uniform magnitude within a predetermined error range to a plurality of output terminals.
Claims14
A current mirroring circuit, comprising:
- a current generation unit configured to generate a first current and a second current;
- and
- a plurality of current mirroring units each including an N-type output transistor configured to mirror the first current and a P-type output transistor configured to mirror the second current, and supplying a current corresponding to a difference between the mirroring current of the P-type output transistor and the mirroring current of the N-type output transistor to output terminals,
- wherein source sides of the N-type output transistors of the current mirroring units are connected to different positions on a first wire and source sides of the P-type output transistors of the current mirroring units are connected to different positions on a second wire,
- wherein magnitudes of currents at the output terminals of the current mirroring units construct a shape in which a magnitude of the current flowing to the output terminal at a middle position is larger or smaller than magnitudes of the current flowing to the output terminals at both ends.
A panel driving apparatus for driving a panel including a plurality of pixels, a plurality of data lines for driving the pixels, and a plurality of sensing lines for sensing characteristics of the pixels, the panel driving apparatus comprising:
- a sensing circuit including a plurality of current mirroring units configured to supply test currents to the sensing lines through a plurality of output terminals, to sense signals generated in the pixels by the test currents, to produce pixel sensing data by digitalizing the signals, to include an N-type output transistor configured to mirror a first current and a P-type output transistor configured to mirror a second current, and to supply the test currents corresponding to a difference between the mirroring current of the P-type output transistor and the mirroring current of the N-type output transistor to the output terminals;
- and
- a data driving circuit configured to receive image data compensated on the basis of the pixel sensing data, to convert the image data into a data voltage, and to supply the data voltage to the data lines.
An OLED (Organic Light Emitting Diode) driver for driving an OLED panel including a plurality of OLED pixels, a plurality of data lines for driving the OLED pixels, and a plurality of sensing lines for sensing characteristics of the OLED pixels, the OLED driver comprising:
- a sensing circuit configured to include a plurality of current mirroring unit, which each includes an N-type output transistor configured to mirror a first current and a P-type output transistor configured to mirror a second current and supplies test currents corresponding to a difference between the mirroring current of the P-type output transistor and the mirroring current of the N-type output transistor to the sensing lines through output terminals, and to produce pixel sensing data by digitalizing signals generated in the sensing lines;
- and
- a data driving circuit configured to receive image data compensated on the basis of the pixel sensing data, to convert the image data into a data voltage, and to supply the data voltage to the data lines.
Dependencies are inferred from the claim text.