Display device having first and second display areas

1. A display device comprising:

a first display area comprising main sub-pixels;

a second display area comprising pixel groups spaced apart from each other and a transmission portion between the pixel groups, the second display area having a different resolution from that of the first display area; and

extension lines between two pixel groups adjacent to each other in a first direction among the pixel groups and extending in the first direction,

wherein each of the pixel groups comprises a plurality of auxiliary sub-pixels and a plurality of horizontal lines electrically connected to the plurality of auxiliary sub-pixels and extending in the first direction,

wherein the extension lines are electrically connected to the horizontal lines included in each of the two pixel groups, and a number of the extension lines is less than a number of the horizontal lines, and

wherein, on a plane, a width of an area in which the extension lines are arranged in a second direction perpendicular to the first direction is less than a width of an area in which the horizontal lines are arranged in the second direction.

2. The display device of claim 1 , wherein two adjacent extension lines from among the extension lines are located on different layers.

3. The display device of claim 1 , wherein each of the plurality of auxiliary sub-pixels comprises a pixel circuit and a display element electrically connected to the pixel circuit,

the pixel circuit comprises a driving thin-film transistor configured to supply a driving current to the display element, a first initialization thin-film transistor configured to initialize a voltage of a driving gate electrode of the driving thin-film transistor, and a second initialization thin-film transistor configured to initialize a pixel electrode of the display element,

the horizontal lines comprise a first initialization voltage line configured to transmit an initialization voltage to the first initialization thin-film transistor and a second initialization voltage line configured to transmit the initialization voltage to the second initialization thin-film transistor, and

the first initialization voltage line and the second initialization voltage line are electrically connected to each other by a first connection line.

4. The display device of claim 3 , wherein the pixel circuit further comprises a switching thin-film transistor configured to transmit a data signal to a driving source electrode of the driving thin-film transistor,

the horizontal lines further comprise a first scan line configured to transmit a previous scan signal to the first initialization thin-film transistor, a second scan line electrically connected to a switching gate electrode of the switching thin-film transistor, and a third scan line electrically connected to a second initialization gate electrode of the second initialization thin-film transistor, and

the second scan line and the third scan line are electrically connected to each other by a second connection line, and a same scan signal is applied thereto.

5. The display device of claim 4 , wherein at least one of the first connection line or the second connection line is located on a different layer from that of the horizontal lines.

6. The display device of claim 4 , wherein each of the pixel groups comprises a first row and a second row in which the plurality of auxiliary sub-pixels are arranged in the first direction,

a first auxiliary sub-pixel in the first row and a second auxiliary sub-pixel in the second row are arranged adjacent to each other in a second direction perpendicular to the first direction, and

the second initialization voltage line and the third scan line are shared by the first auxiliary sub-pixel and the second auxiliary sub-pixel.

7. The display device of claim 6 , wherein the second initialization voltage line and the third scan line are each electrically connected to a first initialization thin-film transistor of the second auxiliary sub-pixel.

8. The display device of claim 6 , wherein the horizontal lines further comprise a third initialization voltage line that crosses the second row in the first direction and along which an initialization voltage is applied to a second initialization thin-film transistor of the second auxiliary sub-pixel, and

the third initialization voltage line is electrically connected to the first connection line.

9. The display device of claim 6 , wherein the horizontal lines further comprise a first emission control line crossing the first row in the first direction, and a second emission control line crossing the second row in the first direction, and

the first emission control line and the second emission control line are electrically connected to each other so that a same emission control signal is transmitted to the first auxiliary sub-pixel and the second auxiliary sub-pixel.

10. The display device of claim 1 , wherein the second display area is surrounded by the first display area.

11. A display device comprising:

a display panel having a first display area and a second display area having different resolutions from each other; and

an electronic element corresponding to the second display area of the display panel,

wherein the display panel comprises:

a substrate;

a plurality of main sub-pixels on the substrate in the first display area;

a plurality of pixel groups on the substrate and spaced apart from each other in the second display area; and

extension lines between two pixel groups adjacent to each other in a first direction among the pixel groups and extending in the first direction,

wherein each of the pixel groups comprises a plurality of auxiliary sub-pixels and a plurality of horizontal lines electrically connected to the plurality of auxiliary sub-pixels and extending in the first direction,

wherein the extension lines are electrically connected to the horizontal lines included in each of the two pixel groups, and

wherein, on a plane, a width of an area in which the extension lines are arranged in a second direction perpendicular to the first direction is less than a width of an area in which the horizontal lines are arranged in the second direction.

12. The display device of claim 11 , wherein two adjacent extension lines from among the extension lines are located on different layers.

13. The display device of claim 11 , wherein each of the plurality of auxiliary sub-pixels comprises a pixel circuit and a display element electrically connected to the pixel circuit,

the pixel circuit comprises a driving thin-film transistor configured to supply a driving current to the display element, a first initialization thin-film transistor configured to initialize a voltage of a driving gate electrode of the driving thin-film transistor, and a second initialization thin film transistor configured to initialize a pixel electrode of the display element, and

the horizontal lines comprise a first initialization voltage line configured to transmit an initialization voltage to the first initialization thin-film transistor and a second initialization voltage line configured to transmit the initialization voltage to the second initialization thin-film transistor,

wherein the first initialization voltage line and the second initialization voltage line are electrically connected to each other by a first connection line.

14. The display device of claim 13 , wherein the pixel circuit further comprises a switching thin-film transistor configured to transmit a data signal to a driving source electrode of the driving thin-film transistor,

the horizontal lines further comprise a first scan line configured to transmit a previous scan signal to the first initialization thin-film transistor, a second scan line electrically connected to a switching gate electrode of the switching thin-film transistor, and a third scan line electrically connected to a second initialization gate electrode of the second initialization thin-film transistor, and

the second scan line and the third scan line are electrically connected to each other by a second connection line, and a same scan signal is applied thereto.

15. The display device of claim 14 , wherein each of the pixel groups comprises a first row and a second row in which the plurality of auxiliary sub-pixels are arranged in the first direction,

a first auxiliary sub-pixel included in the first row and a second auxiliary sub-pixel included in the second row are adjacent to each other in a second direction perpendicular to the first direction, and

the second initialization voltage line and the third scan line are electrically connected to a first initialization thin-film transistor of the second auxiliary sub-pixel.

16. The display device of claim 15 , wherein the horizontal lines further comprise a third initialization voltage line that crosses the second row in the first direction and along which an initialization voltage is applied to a second initialization thin-film transistor of the second auxiliary sub-pixel,

wherein the third initialization voltage line is electrically connected to the first connection line.

17. The display device of claim 15 , wherein the horizontal lines further comprise a first emission control line crossing the first row in the first direction, and a second emission control line crossing the second row in the first direction, and

the first emission control line and the second emission control line are electrically connected to each other so that a same emission control signal is transmitted to the first auxiliary sub-pixel and the second auxiliary sub-pixel.

18. The display device of claim 11 , wherein a number of the extension lines is less than a number of the horizontal lines.

19. The display device of claim 11 , wherein the electronic element comprises an imaging device.