Electronic Design

Digital Ink Technology Debuts In Thin Touchscreen

With a sensor thickness range of 0.36 to about 50.8 mm for the glass, a new flat panel takes advantage of "digital ink" technology, which lets users write on a computer touchpanel as if they were writing on paper with liquid ink. This form-fitting, unbreakable, wear-resistant touchscreen can accept many inputs, such as a stylus, a finger, or a gloved hand. Its palm-rejection feature rejects extraneous signals created by the user's palm print while touching the panel with a pen.

Diagonally measuring 5.7 in., the flat panel can transform any surface into a touchscreen. It's designed for applications where thinness, power efficiency, and low weight are critical, like retail signature capture, Web phones, PDAs, gaming devices, GPS devices, and other handhelds. Customers can choose from any first-surface material (plastic or glass), including a store window front, tabletop, or bulletproof glass. Other attributes include special antibacterial, antismudge, and electromagnetic-interference coatings; chemical resistance; flammability up to UL 94 HB; and scratch resistance per ASTM specifications from 5H to 9H.

The panel transmits light at up to 95% at 550 nm (depending on surface finish) and is 99.5% accurate. It has 10 ms or less of chattering time and insulation impedance of more than 20 MΩ at 10 V. Also, it can track pen inputs at 40 in./s, is activated by a force of 75 grams, and has a response time of 10 ms. Rated for 300 million touches in a single location, it features an RS-232C and USB interface, operates from 3.3 to 5 V, has an operating-temperature range of −15°C to 70°C, and works with Windows 95/98/2000/XP and Mac operating systems.

Based on order size and specifications, the digital ink panel costs from $10 to $60, including the sensor and controller. It comes with a 10-year warranty.

Touch International
(512) 388-0090

See associated figure.

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