Stereoscopic image display device, control device, and display processing method

A control device, comprising:

• a detector configured to detect a viewpoint position representing a position of a viewer;
• a calculator configured to calculate a gravity point of the viewpoint positions when a plurality of viewpoint positions are detected;
• a deriver configured to derive a drive mode according to the gravity point, the drive mode indicating a voltage to be applied to an optical element of which a refractive-index distribution changes according to an applied voltage;
• and
• an applier to apply a voltage to the optical element according to the drive mode such that a visible area within which a display object displayed on a display having a display surface including pixels arranged thereon is stereoscopically viewable is set at the gravity position.

A display processing method implemented in a stereoscopic image display device that includes a display having a display surface with pixels arranged thereon, and an optical element of which a refractive-index distribution changes according to an applied voltage, the method comprising:

• detecting a viewpoint position representing a position of a viewer;
• calculating a gravity point of the viewpoint positions when a plurality of viewpoint positions are detected;
• deriving a drive mode according to the gravity point, the drive mode indicating a voltage to be applied to the optical element;
• and
• applying a voltage to the optical element according to the drive mode such that a visible area within which a display object displayed on the display is stereoscopically viewable is set at the gravity position.