Display device
In an organic EL display device including a proximity sensor, deterioration in display quality due to irradiation with IR light is suppressed. In the organic EL display device including the proximity sensor is provided with a light shielding unit that prevents a channel layer of a first initialization transistor from being irradiated with IR light, the first initialization transistor being provided in a pixel circuit in order to initialize a voltage that is applied to a control terminal of a drive transistor. The first initialization transistor preferably has a dual-gate structure. The first initialization transistor may have a LDD structure (including a one-side LDD structure).
1. A display device provided with a pixel circuit including a display element driven by a current, the display device comprising:
a display unit that includes
a plurality of the pixel circuits of a plurality of rows and a plurality of columns,
a plurality of data signal lines configured to supply data signals to a plurality of the pixel circuits in corresponding respective columns,
a plurality of scanning signal lines configured to control writing of the data signals into a plurality of the pixel circuits in corresponding respective rows,
a plurality of light-emission control lines configured to control whether to supply a current to the display element included in each of a plurality of the pixel circuits in the corresponding respective rows,
a first power line configured to supply a high-level power supply voltage,
a second power line configured to supply a low-level power supply voltage, and
an initialization power line configured to supply an initialization voltage; and
a proximity sensor that includes
an emitting unit configured to emit infrared light from a back surface of the display unit, and
a light receiving unit configured to receive reflected light of the infrared light, wherein
each pixel circuit includes
a control node,
the display element including a first terminal and a second terminal connected to the second power line,
a drive transistor having a control terminal connected to the control node, a first conduction terminal, and a second conduction terminal, the drive transistor being provided in series with the display element,
a light-emission control transistor having a control terminal connected to one of the plurality of light-emission control lines, a first conduction terminal, and a second conduction terminal, the light-emission control transistor being provided in series with the display element,
a holding capacitor having one end connected to the first power line and the other end connected to the control node,
a write control transistor having a control terminal connected to one of the plurality of scanning signal lines, a first conduction terminal connected to one of the plurality of data signal lines, and a second conduction terminal connected to the first conduction terminal of the drive transistor,
a threshold voltage compensation transistor having a control terminal connected to one of the plurality of scanning signal lines, a first conduction terminal connected to the second conduction terminal of the drive transistor, and a second conduction terminal connected to the control node, and
a first initialization transistor having a control terminal connected to one of the plurality of scanning signal lines, a first conduction terminal connected to the control node, and a second conduction terminal connected to the initialization power line, and
a first light shielding unit configured to prevent a channel layer of the first initialization transistor from being irradiated with the infrared light is provided.
2. The display device according to claim 1 , wherein a light shielding unit configured to prevent a channel layer of a transistor included in the pixel circuit from being irradiated with the infrared light is the first light shielding unit provided in an island shape corresponding to the pixel circuit.
3. The display device according to claim 1 , wherein a second light shielding unit that prevents a channel layer of the threshold voltage compensation transistor from being irradiated with the infrared light is provided.
4. The display device according to claim 3 , wherein the first light shielding unit and the second light shielding unit are formed in the same layer and using the same material.
5. The display device according to claim 1 , wherein the first light shielding unit is provided for each pixel circuit in a whole of the display unit.
6. The display device according to claim 1 , wherein the first initialization transistor has a lightly doped drain (LDD) structure.
7. The display device according to claim 6 , wherein
the first initialization transistor has the LDD structure only for one of a first conduction terminal side and a second conduction terminal side, and
the first light shielding unit is provided on a side having no LDD structure out of the first conduction terminal side and the second conduction terminal side.
8. The display device according to claim 1 , wherein the first initialization transistor has a dual-gate structure including two transistors connected in series.
9. The display device according to claim 1 , wherein the first light shielding unit is a metal member and is electrically connected to the first conduction terminal or the second conduction terminal of the first initialization transistor.
10. The display device according to claim 1 , wherein the first light shielding unit is a plate-shaped metal member made of the same material as the plurality of scanning signal lines.
11. The display device according to claim 1 , wherein the first light shielding unit is a plate-shaped resin member having a property of absorbing the infrared light.
12. The display device according to claim 1 , wherein the first light shielding unit is a plate-shaped resin member having a property of scattering the infrared light.
13. The display device according to claim 1 , wherein
the first conduction terminal of the light-emission control transistor is connected to the second conduction terminal of the drive transistor, and
the second conduction terminal of the light-emission control transistor is connected to the first terminal of the display element, and
each pixel circuit includes a power supply control transistor having a control terminal connected to one of the plurality of light-emission control lines, a first conduction terminal connected to the first power line, and a second conduction terminal connected to the first conduction terminal of the drive transistor.
14. The display device according to claim 13 , wherein each pixel circuit includes a second initialization transistor having a control terminal connected to one of the plurality of scanning signal lines, a first conduction terminal connected to the first terminal of the display element, and a second conduction terminal connected to the initialization power line.
15. The display device according to claim 1 , wherein the emitting unit emits the infrared light in a period during which the first initialization transistor is in an off-state in each of all pixel circuits in an infrared light irradiation region that is irradiated with the infrared light and the write control transistor is in an off-state in each of all pixel circuits in the infrared light irradiation region.