| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a positional information detection system capable of preventing deterioration of image quality requiring no complicated initial setting while reducing the system cost.SOLUTION: A positional information detection system 1, which is a system for entering a piece of information concerning an indication position on a display area of an LCD 50, includes a light emission unit 11 and an operation unit 10. The light emission unit 11 has a light emitting module group 112 disposed along a circumference of the LCD 50. A control circuit 1111 controls the light emitting module group 112 to cause LEDs emit light time-sequentially in a state the light emitting timing and the light emitting position are associated with each other. The operation unit 10 has a sensor unit 102 including optical sensors 102a-102d. The optical sensors 102a-102d receive the light from an LED included in the light emitting module group 112. A position determination circuit 1011 determines an intersection position as an indication position based on four light detection results.</p> |
