• National patents: US
• Publication number: US20030052257 A1
• Publication type: Application
• Application number: US 10/224,590
• Publication date: Mar. 20, 2001
• Filing date: Aug. 21, 2002
• Priority date: Aug. 21, 2001
• Patent number: US6765193 B2
• Date of Patent: Jul. 20, 2004
• Inventor: Sarun Sumriddetchkajorn
• Original Assignee: Sarun Sumriddetchkajorn
• Status: Patented

ABSTRACT:

Optical touch switches are implemented based on the use of light total internal reflection and light scattering concepts. The optical touch switch basically consists of a light source, a light guide, a photodetector, and an electronic controller. The fingertip touching on the touching surface of the optical touch switch leads to the change in electrical current produced by the photodetector. As a result, the electronic control box senses this change of electrical current and allows the electrical load to stay at the desired state. Key advantages include ease of implementation, prevention of the light beam incident directly on the user’s eyes, and ability to accept both strong and weak mechanical forces from users.