초록 ▼

In a light-emitting element drive circuit in an active matrix display device, at least one current-control transistor controls a current flowing through a light-emitting element are connected in parallel to each other. A constant current source is connected to a junction between one electrode of the

In a light-emitting element drive circuit in an active matrix display device, at least one current-control transistor controls a current flowing through a light-emitting element are connected in parallel to each other. A constant current source is connected to a junction between one electrode of the light-emitting element and one electrode of the transistor through which the current 8s controlled to flow. The other electrodes of the light-emitting element and the transistor are connected to a common electrode which may be grounded via a resistor. In other configuration, it may be arranged that the light-emitting element and a capacitance are connected in parallel to each other. In this case, the current-control transistor is connected to a junction between the light-emitting element and the capacitance so as to use charging and discharging operations of the capacitance for driving the light-emitting element.

대표청구항 ▼

[ What is claimed is:] [1.] A current-dependent light-emitting element drive circuit for use in an active matrix display device having a plurality of first lines extending in parallel with one another and a plurality of second lines extending perpendicular to said first lines to form a plurality of

[ What is claimed is:] [1.] A current-dependent light-emitting element drive circuit for use in an active matrix display device having a plurality of first lines extending in parallel with one another and a plurality of second lines extending perpendicular to said first lines to form a plurality of cross points arranged in a matrix form, said current-dependent light-emitting element drive circuit being connected to one of said first lines and one of said second lines at each of said cross points to form a pixel in the display device, said current-dependent light-emitting element drive circuit comprising:a current-dependent light-emitting element having a first terminal connected to an external current supply means and a second terminal;current control means coupled to said first and said second lines and connected to said second terminal of said current-dependent light-emitting element for controlling current flowing through said current-dependent light-emitting element from said current supply means in response to selection signals selectively applied to said first and said second lines; anda capacitor connected in parallel with said current-dependent light-emitting element.