Back to results
US 2026/0229174 A1Published application
Display device and method for driving same
AssigneeSharp Display Technology Corporation
InventorKohhei TANAKA
Life of this patent
Estimating the term…
Abstract
In a current-driven display device of an internal compensation type, an on-bias application period Tobs is provided in order to apply an on-bias voltage to the drive transistor in the pixel circuit within non-light emission periods in both refresh frame periods and non-refresh frame periods in a pause driving mode. During the non-light emission period in a refresh frame period, the pixel circuit is driven via existing signal lines and voltage lines such that the on-bias voltage is applied during the period between the start of the non-light emission period and the start of writing of a data voltage to the pixel circuit. This reduces the difference in the stress state of the drive transistor between refresh frame periods and non-refresh frame periods.
Claims15
A display device comprising:
- a display portion including a plurality of pixel circuits;
- a drive circuit configured to drive the plurality of pixel circuits;
- and
- a display control circuit configured to control the drive circuit such that a drive period and a pause period alternately appear, the drive period consisting of one or more refresh frame periods in which voltage of a plurality of data signals is written, as data voltage, to the plurality of pixel circuits, the pause period consisting of one or more non-refresh frame periods in which writing of data voltage to the plurality of pixel circuits is stopped,
- wherein each of the plurality of pixel circuits includes
- a display element configured to be driven by a current,
- a drive transistor arranged in series with the display element and including a control terminal, a first conduction terminal, and a second conduction terminal,
- a holding capacitor having one terminal connected to the control terminal of the drive transistor and thus being configured to hold a voltage of the control terminal of the drive transistor,
- a write control transistor, as a switching element, having a first conduction terminal configured to receive a data voltage to be written to the holding capacitor and a second conduction terminal connected to the first conduction terminal of the drive transistor,
- a threshold compensation transistor, as a switching element, arranged between the second conduction terminal and the control terminal of the drive transistor, and configured to put the drive transistor in a diode-connected state when in ON state,
- at least one emission control transistor, as a switching element, arranged in series with the display element and the drive transistor, and
- a bias application circuit configured to apply, to the first conduction terminal of the drive transistor, a bias voltage for reducing threshold voltage shift caused by a hysteresis characteristic of the drive transistor,
- wherein in each of the plurality of pixel circuits, the bias application circuit has
- a first terminal configured to receive one of signals provided to control terminals of transistors each of which is included in the each of the plurality of pixel circuits or in another pixel circuit, but none of which are included in the bias application circuit, or to receive one of the power supply voltages of the plurality of pixel circuits, and
- a second terminal connected to the first conductive terminal of the drive transistor, and
- the bias application circuit is configured to apply the bias voltage to the first conductive terminal of the drive transistor based on the signal or the voltage received at the first terminal.
13 more elements
A method for driving a display device using a display element driven by a current, wherein
- the display device comprises a display portion including a plurality of pixel circuits,
- each of the plurality of pixel circuits including:
- a display element driven by a current;
- a drive transistor having a control terminal, a first conduction terminal, and a second conduction terminal, and arranged in series with the display element;
- a holding capacitor having one terminal connected to the control terminal of the drive transistor and thus being configured to hold a voltage at the control terminal of the drive transistor;
- a write control transistor, as a switching element, having a first conduction terminal configured to receive a data voltage to be written to the holding capacitor and a second conduction terminal connected to the first conduction terminal of the drive transistor;
- a threshold compensation transistor, as a switching element, arranged between the second conduction terminal and the control terminal of the drive transistor, and configured to put the drive transistor in a diode-connected state when in ON state;
- at least one emission control transistor, as a switching element, arranged in series with the display element and the drive transistor, and
- a bias application circuit configured to apply, to the first conductive terminal of the drive transistor, a bias voltage for reducing threshold voltage shift caused by a hysteresis characteristic of the drive transistor, wherein in each of the plurality of pixel circuits, the bias application circuit having a first terminal configured to receive one of signals provided to control terminals of transistors each of which is included in the each of the plurality of pixel circuits or in another pixel circuit, but none of which are included in the bias application circuit, or to receive one of the power supply voltages of the plurality of pixel circuits, and having a second terminal connected to the first conductive terminal of the drive transistor,
- the method comprising performing a pause driving by driving the plurality of pixel circuits such that a drive period and a pause period alternately appear, the drive period consisting of one or more refresh frame periods in which voltage of a plurality of data signals is written, as data voltage, to the plurality of pixel circuits, the pause period consisting of one or more non-refresh frame periods in which writing of data voltage to the plurality of pixel circuits is stopped,
- wherein the performing the pause driving includes performing a bias application by driving the plurality of pixel circuits such that the bias application circuit applies the bias voltage to the first conduction terminal of the drive transistor based on the signal or the voltage received at the first terminal within a period during which the emission control transistor in each of the plurality of pixel circuits is in OFF state in both the refresh frame period and the non-refresh frame period.
8 more elements
Dependencies are inferred from the claim text.