Development of Projection-Type Electrostatic Capacitance Touch Panel by Hitachi Display
Widely use of touch panels both in smart phone and digital cameras will continue to play an important role in maintaining the high growth rate of this technology. Recently, the projection type electrostatic capacitance touch panels are gaining in popularity for allowing only a very light touch, not mentioning their multi-touch operations capability. Up to now, the projection-type electrostatic capacitance touch-panels produced a mild electric current on the surface of the LCD, where it detects changes in the electric current to determine where the user’s fingers is touching the display. However, in such scenario, non-conductive objects such a plastic stylus or a gloved hand could not be used since they have no effect on electric current. To overcome this, Hitachi Display has developed a projective-type electrostatic capacitance touch-panel capable of converting input from a non-conductive object into electrostatic capacitance, allowing use of plastic stylus and gloved hands or other similar objects on this type of display. The new technology is capable of detecting both conductive as well as non-conductive objects, all without compromising responsiveness to light touch or design considerations.
Hitachi display has used a common controller IC as the detection controller, allowing the data entry with a coordinate detection error of ±0.5mm or less when using a stylus with a 0.8mm tip. Additionally, other type of non-conductive materials such as wool and natural or synthetic leather as well as synthetic fabric can also be used. This will result in performing simultaneous operation using both plastic stylus and your fingers, opening new possibilities for variety of new applications and interfaces. Well, use of stylus pen or gloves on such display will become handy in cold climates.