Patent ID: 7586468

Claim:
A display device for presenting display using a current video signal, comprising: a voltage-current conversion circuit for converting a voltage video signal into a current video signal; and a current driving pixel circuit for receiving the current video signal output from said voltage-current conversion circuit to present display, wherein said voltage-current conversion circuit comprises: an output transistor for receiving the voltage video signal at a gate, and supplying corresponding drain current, and a compensation circuit for compensating for variation in threshold voltage of said output transistor; said current driving pixel circuit comprises: a transistor with a gate connected to a gate line; and a driving transistor that is driven by a current video signal; and the drain current is supplied to the current driving pixel circuit through the transistor with a gate connected to a gate line wherein said compensation circuit comprises: a storage capacitor for receiving at one end and holding a data voltage supplied to the gate of said output transistor, a first control signal line connected to the other end of said storage capacitor, and receiving a predetermined voltage or a pulsed signal, and a MOS capacitor element having one end connected to the gate of said output transistor, and the other end connected to a second control signal line for receiving a predetermined voltage or a pulsed signal, wherein a capacitance of the MOS capacitor element is changed by varying the ON/OFF state of said MOS capacitor element with a change in voltage on said first or second control signal line.