CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Phase patent application and claims priority to and the benefit of International Application Number PCT/KR2019/003695, filed on Mar. 29, 2019, which claims priority to Korean Patent Application Number 10-2018-0092107, filed on Aug. 7, 2018, the entire contents of each of which are incorporated herein by reference.

TECHNICAL FIELD

Embodiments related to a display device. More particularly, embodiments relate to an organic light emitting display device including a plurality of transistors.

BACKGROUND ART

Recently, flat display devices are generally used as a display device. In particular, an organic light emitting display device among the flat display devices has been spotlighted as a next-generation display device because of advantages of being relatively thin and light and having low power consumption and high response speed.

The organic light emitting display device may include a plurality of thin film transistors and organic light emitting elements connected to the thin film transistors. The organic light emitting element may emit light having a luminance corresponding to a voltage supplied to the organic light emitting element through a thin film transistor.

DISCLOSURE

Technical Problem

Some example embodiments include a display device including a transistor having improved characteristics.

Technical Solution

In order to achieve the object of the present invention described above, a display device may include a substrate, an organic light emitting element on the substrate, a pixel circuit between the substrate and the organic light emitting element, electrically connected to the organic light emitting element, and including a first transistor and a second transistor, a first metal layer between the substrate and the pixel circuit, overlapping the first transistor, and supplied with a first voltage, and a second metal layer between the substrate and the pixel circuit, overlapping the second transistor, and supplied with a second voltage different from the first voltage.

In one embodiment, the first voltage and the second voltage may have polarities different from each other.

In one embodiment, the first transistor and the second transistor may have driving ranges different from each other.

In one embodiment, the first voltage may have a negative polarity, and the second voltage may have a positive polarity.

In one embodiment, the first voltage may be −3 V to −5 V.

In one embodiment, the second voltage may be +4 V to +6 V.

In one embodiment, the first transistor may include a first active pattern on the substrate and including a first channel, and a first gate electrode on the first active pattern, and the first metal layer may overlap the first channel.

In one embodiment, the second transistor may include a second active pattern connected between the first active pattern and the first gate electrode and including a second channel, and a second gate electrode on the second active pattern, and the second metal layer may overlap the second channel.

In one embodiment, the pixel circuit may further include a third transistor including a third active pattern connected to the first active pattern, and a third gate electrode on the third active pattern, and the second metal layer may overlap the third channel.

In one embodiment, the first transistor may have a driving range wider than a driving range of the second transistor.

In one embodiment, the first metal layer may be connected to a connection line outside the pixel circuit.

In one embodiment, the second metal layer may be connected to a connection line outside the pixel circuit or connected to a driving voltage line crossing the pixel circuit.

In one embodiment, each of the first transistor and the second transistor may include a PMOS transistor.

In order to achieve the object of the present invention described above, a display device may include a substrate including a display area and a peripheral area, a plurality of organic light emitting elements on the display area of the substrate, a plurality of pixel circuits between the substrate and the organic light emitting elements, electrically connected to the organic light emitting elements, respectively, and each including a first transistor and a second transistor, a plurality of first metal lines between the substrate and the pixel circuits, overlapping the first transistor of each of the pixel circuits, and supplied with a first voltage, and a plurality of second metal lines between the substrate and the pixel circuits, overlapping the second transistor of each of the pixel circuits, and supplied with a second voltage different from the first voltage.

In one embodiment, the display device may further include a plurality of driving voltage lines extending in a first direction and supplying driving voltages to the organic light emitting elements. The first metal lines and the second metal lines may extend in a second direction intersecting the first direction.

In one embodiment, the display device may further include a first connection line extending in the first direction and connected to the first metal lines. The first connection line may receive the first voltage through a first pad on the peripheral area of the substrate.

In one embodiment, the second metal lines may be connected to the driving voltage lines, respectively, and the second metal lines may receive the second voltage through the driving voltage lines, respectively.

In one embodiment, the display device may further include a second connection line extending in the first direction and connected to the second metal lines. The second connection line may receive the second voltage through a second pad on the peripheral area of the substrate.

In one embodiment, the first voltage and the second voltage may have polarities different from each other.

In one embodiment, the first transistor and the second transistor may have driving ranges different from each other.

Advantageous Effects

In the display device according to the embodiments, the first voltage supplied to the first metal layer overlapping the first transistor and the second voltage supplied to the second metal layer overlapping the second transistor may be different from each other, so that the driving range of the first transistor and the driving range of the second transistor may be different from each other, and characteristics of the first and second transistor may be improved.

