Browse Prior Art Database

Calibration-Point-Marking Technique for a Touchscreen

IP.com Disclosure Number: IPCOM000039288D
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Farringer, JA: AUTHOR [+2]

Abstract

Touchscreen devices are often attached to CRT displays in interactive data processing systems so that an operator can input data to the system. One such device 1, shown in Fig. 1, includes a glass window 2, a frame 3 and elements 4 for securing touchscreen 1 to a display. Four piezoelectric transducers 5 are accurately secured by adhesive 6 to the glass at precise locations in the four corners, as illustrated in Fig. 2. During manufacture, touchscreen 1 is placed in a holding fixture 7, and an installation tool 8 is used to accurately position the transducers on the glass. The tool includes four cylinders 9 attached to a vacuum source 10. Transducers 5 are placed in the free ends of the cylinders and held there by the vacuum.

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Calibration-Point-Marking Technique for a Touchscreen

Touchscreen devices are often attached to CRT displays in interactive data processing systems so that an operator can input data to the system. One such device 1, shown in Fig. 1, includes a glass window 2, a frame 3 and elements 4 for securing touchscreen 1 to a display. Four piezoelectric transducers 5 are accurately secured by adhesive 6 to the glass at precise locations in the four corners, as illustrated in Fig. 2. During manufacture, touchscreen 1 is placed in a holding fixture 7, and an installation tool 8 is used to accurately position the transducers on the glass. The tool includes four cylinders 9 attached to a vacuum source 10. Transducers 5 are placed in the free ends of the cylinders and held there by the vacuum. The peel-back layers over the adhesive on the transducers are removed and tool 8 presses the transducers against the glass where they are permanently retained. Current touchscreen calibration routines required geometric information about transducer locations in order that X-Y calculated loc

(Image Omitted)

ations can be determined and referenced accurately. One method requires repeated touches at the center of the touchscreen. Since CRT images drift and expand and contract, and screen installation locations vary, visual targets which are displayed by a CRT are not exact reference points. The installation tool 8 includes a spring-loaded dot marker 11 accurately located at the center point...