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MPCT Touch
Itron has applied its vacuum fluorescent display (VPD) process to the production of projective capacitive touch sensors which it claims has performance and set-up benefits compared with indium tin oxide (ITO)-based projective capacitive touch panels.
This low impedance touch technology, which the firm calls MPC Touch, works with 4mm of plastic or 8mm of glass overlay and is able to support applications where users are wearing a range of gloves from nitrile, nylon, cotton and leather.
“Rain drops do not false-trigger the touch screen when the front panel is inclined to allow water to run off,” said Itron UK managing director, Andy Stubbings.
Another assembly benefit is that no bonding is required between the touch panel and the front overlay since a 0.5mm air gap is allowed.
This permits the touch sensor to be fitted to the TFT assembly and offered up to the front panel. The low impedance also allows the use of more compact flex foils making it possible to retrofit the sensors into existing applications.
“Unlike the conventional ITO PCT which requires significant tuning to suit the application, MPC Touch can use one threshold value for varying thickness of front panel material,” said Stubbings.
Current standard panel sizes in 4.3-inch and 7-inch are being expanded to include 3.5-inch and 5.7-inch options.
Custom panels up to 10.4inches can be tooled where quantities exceed 500/year and have a typical one time set up charge of £3500. Semi-custom sizes can be cut from larger standard panels to allow short run or rapid prototyping.
A capacitive touch controller module part number MCBK42 suits all sizes of MPC panel and provides host interface via asynchronous serial or twin wire I2C interface. On-board linear and digital voltage regulation enables 3.3V or 5V power supply support.
