Abstract: A system for users to play games on regular surface (201) such as printed material is provided. The system consists of an ultrasonic pointing unit (216), an ultrasonic base unit (213), a control unit (220) and a response unit (240), together with response data (500) and game rules (1100). The user interacts with the surface (201) by placing the ultrasonic pointing unit (216) on various areas of the surface (10). Ultrasonic wave propagates between the ultrasonic point unit (216) and ultrasonic base unit (213). By measuring multiple time-of-flight of ultrasonic wave, the location of the ultrasonic pointing unit (216) could be determined, and the device makes appropriate audio or other responses. Also, with the additions of game rules (1100), the system could ask users questions, or instruct users to tracing pictures or letters, or instruct users to walk a maze, etc. A surface (201) is thereby transformed into an interactive experience with various sound or visual effects.

Abstract: A system for readers to interact with printed materials (201) such as books is provided. The system consists of an ultrasonic pointing unit (216), an ultrasonic base unit (213), a control unit (220) and a response unit (240). The reader interacts with the printed material (201) by placing the ultrasonic pointing unit (216) on various areas of the printed page (10). Ultrasonic wave propagates between the ultrasonic point unit (216) and ultrasonic base unit (213). By measuring multiple time-of-flight of ultrasonic wave, the location of the ultrasonic pointing unit (216) could be determined, and the device makes appropriate audio or other responses. A printed material (201) is thereby transformed into an interactive experience with various sound or visual effects. The sound effects or other response data (540) are stored in data storage (230) accessible by the control unit (220).