Flexible display device and method of controlling flexible display device

A display device, comprising:

• a flexible substrate that when bent has a curved portion and an uncurved portion;
• a display unit including multiple light-emitting elements arranged on the substrate and configured to display an image within a display area according to an image signal;
• a displacement sensor secured to a front surface, a back surface or both of the substrate and configured to detect a state of curvature of the substrate;
• a control unit configured to control the image signal in accordance with the state of curvature detected by the displacement sensor and to (i) size the image to fit within the uncurved portion of the flexible substrate, (ii) split the display area into at least two split areas, the number of split areas being in inverse relation to the size of the uncurved portion and (iii) simultaneously display within each split area a portion of the image, thereby displaying a split image;
• and
• an image region arithmetic unit configured to calculate a split amount and a reduction percentage of an image region based on a lookup table specifying a relation between an output of the displacement sensor and an image split control amount,
• wherein,
• the control unit controls the image signal according to an amount and position of the curvature of the substrate,
• the control unit is configured to split the image displayed in the display unit differently than when the substrate is recovering and the image is changed to an original state, and
• the control unit controls the split of the image displayed in the display unit based on the split amount and the reduction percentage of the image region calculated by the image region arithmetic unit.