Patent ID: 7570244

Claim:
A display apparatus, comprising: a pixel matrix circuit configured to supply a current to a light emitting element of each pixel; a signal line configured to supply a signal current in accordance with digital image data to said pixel matrix circuit; a reference current generating unit configured to output a bit weighted reference current in correspondence with each bit of said digital image data; a bit weighting current generating unit corresponding to said each bit of said digital image data, said bit weighting current generating unit configured to output a bit weighting current corresponding to said reference current and to correct said bit weighting current by writing the corresponding said reference current; and a switching unit corresponding to said bit weighting current generating unit, said switching unit configured to switch said bit weighting current output from the corresponding said bit weighting current generating unit in accordance with a data level of a corresponding bit, and to add each current switched by said switching unit to form said signal current and to output said signal current to said signal line, wherein said bit weighting current generating unit includes: a first field effect transistor configured to output a current, a second field effect transistor configured to connect the gate and drain of said first field effect transistor when said reference current is written, and a capacitance element connected to the gate of said first field effect transistor, and said second field effect transistor is configured to conduct when said reference current is written so that a gate voltage corresponding to a current flowing through said first field effect transistor is held in said capacitance element, said second field effect transistor is configured to shut off when said bit weighting current is output, and said first field effect transistor is configured to output a current corresponding to the gate voltage held by said capacitance element when said bit weighting current is output.