Display device, display module, and electronic device
To provide a display device in which a reflective liquid crystal element and a light-emitting element are switched for display, and the operation of a reflective liquid crystal element driver IC and the operation of a light-emitting element driver IC can be alternately stopped even when they are integrated. The display device includes a pixel, a driver circuit, and a switching control circuit. The driver IC includes a buffer amplifier for outputting a grayscale voltage to drive the liquid crystal element and a buffer amplifier for outputting a grayscale voltage to drive the light-emitting element. Each buffer amplifier includes a transistor configured to supply a bias current, and a switch. The switch is configured to control a conduction state between a wiring for supplying a bias voltage and a gate of the transistor. The switching control circuit is configured to output a switching signal for controlling a conduction state of the switch.
1. A display device comprising:
a pixel comprising:
a liquid crystal element which comprises a reflective electrode comprising an opening; and
a light-emitting element which is below and overlaps with the opening and is configured to emit light through the opening; and
a source driver circuit comprising:
a first buffer amplifier for the liquid crystal element; and
a second buffer amplifier for the light-emitting element,
wherein each of the first buffer amplifier and the second buffer amplifier comprises a first transistor and a switch electrically connected to a gate of the first transistor,
wherein the switch is configured to alternately switch driving and stopping of the first buffer amplifier and the second buffer amplifier,
wherein an operation of the first buffer amplifier is stopped while the second buffer amplifier is driven, and
wherein an operation of the second buffer amplifier is stopped while the first buffer amplifier is driven.
2. The display device according to claim 1 , further comprising a switching control circuit configured to output a first switching signal to the first buffer amplifier and a second switching signal to the second buffer amplifier.
3. The display device according to claim 1 , further comprising a controller and a sensor,
wherein the sensor is configured to measure illuminance, and
wherein, in accordance with the illuminance measured by the sensor, the controller is configured to switch a first mode for performing display with the liquid crystal element, a second mode for performing display with the liquid crystal element and the light-emitting element, and a third mode for performing display with the light-emitting element.
4. The display device according to claim 1 , wherein the source driver circuit further comprises a first level shifter operationally connected to the first buffer amplifier and a second level shifter operationally connected to the second buffer amplifier.
5. A display module comprising:
the display device according to claim 1 ; and
a touch panel.
6. An electronic device comprising:
the display device according to claim 1 ; and
at least one of an operation key and a battery.
7. The display device according to claim, 1 , further comprising:
a first wiring electrically connected to the first buffer amplifier; and
a second wiring electrically connected to the second buffer amplifier, and
wherein the first wiring is configured to supply a first signal switching a supply of a bias voltage, and
wherein the second wiring is configured to supply a second signal switching a supply of a bias voltage.
8. A display device comprising:
a pixel comprising:
a liquid crystal element which comprises a reflective electrode comprising an opening;
a first pixel circuit configured to drive the liquid crystal element;
a light-emitting element which is below and overlaps with the opening and is configured to emit light through the opening; and
a second pixel circuit configured to drive the light-emitting element; and
a source driver circuit comprising:
a first buffer amplifier for the liquid crystal element; and
a second buffer amplifier for the light-emitting element,
wherein each of the first buffer amplifier and the second buffer amplifier comprises a first transistor and a switch electrically connected to a gate of the first transistor,
wherein the switch is configured to alternately switch driving and stopping of the first buffer amplifier and the second buffer amplifier,
wherein an operation of the first buffer amplifier is stopped while the second buffer amplifier is driven,
wherein an operation of the second buffer amplifier is stopped while the first buffer amplifier is driven, and
wherein each of the first pixel circuit and the second pixel circuit comprises a second transistor comprising an oxide semiconductor layer.
9. The display device according to claim 8 , further comprising a switching control circuit configured to output a first switching signal to the first buffer amplifier and a second switching signal to the second buffer amplifier.
10. The display device according to claim 8 , further comprising a controller and a sensor,
wherein the sensor is configured to measure illuminance, and
wherein, in accordance with the illuminance measured by the sensor, the controller is configured to switch a first mode for performing display with the liquid crystal element, a second mode for performing display with the liquid crystal element and the light-emitting element, and a third mode for performing display with the light-emitting element.
11. The display device according to claim 8 , wherein the source driver circuit further comprises a first level shifter operationally connected to the first buffer amplifier and a second level shifter operationally connected to the second buffer amplifier.
12. A display module comprising:
the display device according to claim 8 ; and
a touch panel.
13. An electronic device comprising:
the display device according to claim 8 ; and
at least one of an operation key and a battery.
14. A display device comprising:
a pixel comprising:
a liquid crystal element which comprises a reflective electrode comprising an opening and is configured to display a grayscale image by reflecting external light;
a first pixel circuit configured to drive the liquid crystal element;
a light-emitting element which is below and overlaps with the opening and is configured to display a grayscale image by emitting light through the opening; and
a second pixel circuit configured to drive the light-emitting element;
a source driver circuit comprising:
a first buffer amplifier configured to output a grayscale voltage to the liquid crystal element; and
a second buffer amplifier configured to output a grayscale voltage to the light-emitting element; and
a switching control circuit,
wherein each of the first buffer amplifier and the second buffer amplifier comprises a first transistor configured to supply a bias current, and a switch between a wiring for supplying a bias voltage and a gate of the first transistor,
wherein the switch is configured to alternately switch driving and stopping of the first buffer amplifier and the second buffer amplifier,
wherein an operation of the first buffer amplifier is stopped while the second buffer amplifier is driven,
wherein an operation of the second buffer amplifier is stopped while the first buffer amplifier is driven, and
wherein the switching control circuit is configured to output a switching signal for controlling a conduction state of the switch.
15. The display device according to claim 14 , wherein the switching signal comprises a first switching signal to be supplied to the first buffer amplifier and a second switching signal to be supplied to the second buffer amplifier.
16. The display device according to claim 14 , further comprising a controller and a sensor,
wherein the sensor is configured to measure illuminance, and
wherein, in accordance with the illuminance measured by the sensor, the controller is configured to switch a first mode for performing display with the liquid crystal element, a second mode for performing display with the liquid crystal element and the light-emitting element, and a third mode for performing display with the light-emitting element.
17. The display device according to claim 14 , wherein the source driver circuit further comprises a first level shifter operationally connected to the first buffer amplifier and a second level shifter operationally connected to the second buffer amplifier.
18. A display module comprising:
the display device according to claim 14 ; and
a touch panel.
19. An electronic device comprising:
the display device according to claim 14 ; and
at least one of an operation key and a battery.