[地理考古资料]Optical touch sensor technology.pdfVIP

ThL5 11:45 - 12:00 Optical Touch Sensor Technology Sarun Sumriddetchkajorn and Ratthasart Amarit Electro-Optics Section, National Electronics and Computer Technology Center National Science and Technology Development Agency 112 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 Thailand Tel: 66-2564-6900 ext. 2102, Fax: 66-2564-6771, E-mail: sarun.sumriddetchkajorn@nectec.or.th Abstract We describe four optical concepts for implementing a compact optical touch sensor with an embedded noise rejection scheme suitable for disabled who have difficulty in operating a mechanical switch. Their performances are also discussed. Today, there is a need of deploying touch sensor into the machine in order to reduce the activating force not only for typical people but also for disabled people, who have faced difficulty in operating a widely used mechanical switch due to spinal muscular atrophy and amyotrophic lateral sclerosis, to operate the machine comfortably. So far, several touch sensors have been proposed and devised based on the use of surface acoustic wave [1], piezoelectric transducer [2], capacitive device [3], and resistive membrane [4]. However, the acoustic approach requires a high driven electrical power while the piezoelectric and capacitive technologies need to have specially designed electronic circuit to prevent a high output saturation voltage as well as to suppress the unwanted electrostatic ind