Patent Number: 8,878,818

Title: Multi-touch optical touch panel

Abstract: A multi-touch optical touch panel which comprises a rectangular position-detecting surface with a length L and a width W; a first set of a plurality of light-emitting element pairs configured for emitting a plurality of light beams, wherein the first set of light-emitting element pairs are arranged at various points along a first side of the position-detecting surface in a lengthwise direction; a second set of a plurality of light-emitting elements are arranged at various points along the first side at 90 degrees with reference to the first side; two reflectors arranged along two opposed sides of the rectangular position-detecting surface in the W direction; and a first set of a plurality of light-receiving element pairs configured for receiving the plurality of light beams emitted by the first set of light-emitting element pairs, wherein the first set of light-receiving element pairs are arranged at various points along a second side of the position-detecting surface opposite to the first side in a lengthwise direction; a second set of a plurality of light-receiving elements are arranged at various points along the second side at -90 degrees with reference to the second side for receiving the plurality of light beams emitted by the second set of light-emitting elements. A control circuit is configured for causing the first set of light-emitting element pairs and the second set of light-emitting elements to emit the plurality of light beams in a predetermined order to scan the position-detecting surface, and further configured for causing the first set of light-receiving element pairs and the second set of light-receiving elements to receive the plurality of light beams, thereby forming optical paths on the position-detecting surface in a grid pattern.

Inventors: Chang; Yu-Jen (New Taipei, TW), Hsuan; Wei-Yi (Taipei, TW), Lee; Yi-Sheng (Taipei Hsien, TW), Parsons; Robert D. (Raleigh, NC)

Assignee: International Business Machines Corporation

International Classification: G06F 3/042 (20060101)

Expiration Date: 2019-11-04 0:00:00