Active matrix-type display device
View Patent ↗When performing gradation expression using a time division driving method, an operational frequency of a driving circuit is suppressed, and non-light emitting time is eliminated to increase the light emitting time. Each of a number of pixel circuits includes a light emitting element, a driver element for turning on or off a driving current of the light emitting element, a switching element for controlling connection of a gate electrode of the driver element with a signal line, and a capacitance to which a signal voltage supplied from the signal line to the gate electrode of the driver element is written.
1. An active matrix-type display device having a pixel circuit for each of a number of pixels arranged in matrix to control the light-emitting period, wherein,
each pixel circuit includes:
a light emitting element which emits light in response to a driving current,
a driver element for controlling the driving current supplied to the light emitting element,
a capacitance in which a signal voltage is written from a signal line for applying a voltage corresponding to the written signal voltage to the gate of the driver element, and
a gate potential control line for shifting the potential of the capacitance to control the gate potential of the driver element, wherein,
one frame is divided into a plurality of subframes, and in each of the subframes, at least three stages of signal voltage are written in the capacitance from the signal line, and
in one subframe, after the signal voltage is written in, the subframe is further divided to form sub-subframes by changing the gate potential of the driver element by the gate potential control line for controlling the gate electrode voltage of the driver element in the sub-subframe by combining the signal voltage and the voltage of the gate potential control line to control a light emitting period of the light emitting element.
2. The active matrix-type display device according to claim 1 , wherein connection of the signal line with the capacitance is controlled by a switching element.
3. The active matrix-type display device according to claim 1 , wherein the sum of lengths of all subframe periods in each of the subframes is equal to the length of one frame period.
4. The active matrix-type display device according to claim 1 , wherein the sub-subframes, in one frame, have a priority light emitting period for a second half sub-subframe in a first half subframe, and a priority light emitting period for a first half sub-subframe in a second half subframe.
5. The active matrix-type display device according to claim 1 , wherein the subframes are of equal length.
6. The active matrix-type display device according to claim 1 , wherein the driver element is a field effect transistor.
7. The active matrix-type display device according to claim 6 , wherein the field effect transistor is a thin film transistor.
8. The active matrix-type display device according to claim 1 , wherein the light emitting element is an organic electroluminescent element.