Display device

1. A display device comprising:

a flexible display panel comprising a recognition pattern;

a housing for holding the flexible display panel, wherein varying amounts of a display area of the flexible display panel are exposable to the outside of the housing for displaying a first image on the display area of the exposed display panel, such that in a first position a first amount of the display area is exposed and a size of the entire first image is adjusted to fit the first amount of the display area, and in a second position a second amount of the display area variably compared with the first amount of the display area is exposed and the size of the entire first image is adjusted to fit the second amount of the display area; and

a sensor in the housing for sensing an amount of the exposed display area corresponding to the recognition pattern,

wherein the flexible display panel further comprises a non-display area neighboring the display area, and

wherein the recognition pattern is disposed in the display area.

2. The display device of claim 1 , further comprising a controller connected with the sensor and the flexible display panel, the controller for displaying an image corresponding to the amount of the exposed display area sensed by the sensor.

3. The display device of claim 2 , wherein the recognition pattern is also in the non-display area.

4. The display device of claim 1 , wherein the flexible display panel is configured to enter and exit the housing along a first direction, and wherein the recognition pattern is formed in the flexible display panel along the first direction.

5. The display device of claim 4 , wherein the recognition pattern comprises first sub-patterns for absorbing light and second sub-patterns for reflecting light that are alternately arranged along the first direction, and the sensor comprises a photo sensor comprising a light emitting portion and a light receiving portion neighboring each other.

6. The display device of claim 4 , wherein the recognition pattern comprises a bar code and the sensor is configured to read or recognize the bar code.

7. The display device of claim 4 , wherein the recognition pattern comprises an ideogram and the sensor is configured to read or recognize the ideogram.

8. The display device of claim 4 , wherein the recognition pattern comprises first sub-patterns for transmitting light and second sub-patterns for blocking light, wherein the first sub-patterns and the second sub-patterns are alternately arranged along the first direction, and the sensor comprises a photo sensor comprising a light emitting portion and a light receiving portion that are arranged on opposite sides of the recognition pattern.

9. The display device of claim 1 , wherein the housing comprises a roll portion in the housing for rolling or storing the flexible display panel.

10. A display device comprising:

a flexible display panel comprising a recognition pattern;

a housing for holding the flexible display panel and defining a display area of the flexible display panel, wherein a size of the entire display device is adjustable to vary amounts of the display area of the flexible display panel exposable to the outside for displaying an image, such that in a first position a first amount of the display area is exposed and in a second position a second amount of the display area variably compared with the first amount of the display area is exposed; and

a sensor in the housing for sensing an amount of the exposed display area corresponding to the recognition pattern,

wherein the flexible display panel further comprises a non-display area neighboring the display area, and

wherein the recognition pattern is disposed in the display area.

11. The display device of claim 10 , further comprising a controller connected with the sensor and the flexible display panel, the controller for displaying an image corresponding to the amount of the exposed display area sensed by the sensor.

12. The display device of claim 11 , wherein the recognition pattern is also in the non-display area.

13. The display device of claim 10 , wherein the flexible display panel is configured to enter and exit the housing along a first direction, and wherein the recognition pattern is formed in the flexible display panel along the first direction.

14. The display device of claim 13 , wherein the recognition pattern comprises first sub-patterns for absorbing light and second sub-patterns for reflecting light that are alternately arranged along the first direction, and the sensor comprises a photo sensor comprising a light emitting portion and a light receiving portion neighboring each other.

15. The display device of claim 13 , wherein the recognition pattern comprises a bar code and the sensor is configured to read or recognize the bar code.

16. The display device of claim 13 , wherein the recognition pattern comprises an ideogram and the sensor is configured to read or recognize the ideogram.

17. The display device of claim 13 , wherein the recognition pattern comprises first sub-patterns for transmitting light and second sub-patterns for blocking light, wherein the first sub-patterns and the second sub-patterns are alternately arranged along the first direction, and the sensor comprises a photo sensor comprising a light emitting portion and a light receiving portion that are arranged on opposite sides of the recognition pattern.

18. The display device of claim 10 , wherein the housing comprises a roll portion in the housing for rolling or storing the flexible display panel.