Abstract: Virtual keypads are provided which determine an intended user key entry based upon location of keystrokes as well as other keystroke characteristics such as keystroke shape and/or pressure. Virtual keypad layouts which include overlapping or multi-character keys may be used to reduce typing errors on small pressure sensing touch screens. Keystrokes on overlapping or multi-character keys may be disambiguated using measured pressures applied to the pressure sensing touch screen as well as other keystroke characteristics such as keystroke shape. Additional user interfaces are provided which exploit pressure sensing touch screen capable of discriminating magnitudes of pressure exerted upon the touch screen surface.

Abstract: Virtual keypads are provided which determine an intended user key entry based upon location of keystrokes as well as other keystroke characteristics such as keystroke shape and/or pressure. Virtual keypad layouts which include overlapping or multi-character keys may be used to reduce typing errors on small pressure sensing touch screens. Keystrokes on overlapping or multi-character keys may be disambiguated using measured pressures applied to the pressure sensing touch screen as well as other keystroke characteristics such as keystroke shape. Additional user interfaces are provided which exploit pressure sensing touch screen capable of discriminating magnitudes of pressure exerted upon the touch screen surface.

Abstract: The present invention provides a full color liquid crystal display of passive matrix design that includes a polarizer, an analyzer having a transmission axis, and at least one light generation stage positioned between the polarizer and analyzer for transmitting light of a desired wavelength to the analyzer. This light generation stage includes a first retarder stack that rotates desired wavelengths of light to a particular polarization state, a second retarder stack inverted and rotated by 90 degrees with respect to said first retarder stack, and a passive matrix addressed optical element positioned between the first and second retarder stacks. The retardation and orientation of each of the first retarder stack, second retarder stack, and passive matrix addressed optical element are optimized so as to provide a color generation stage that places desired wavelengths of light substantially along the transmission axis of the analyzer.

Abstract: The present invention provides a full color liquid crystal display of passive matrix design that includes a polarizer, an analyzer having a transmission axis, and at least one light generation stage positioned between the polarizer and analyzer for transmitting light of a desired wavelength to the analyzer. This light generation stage includes a first retarder stack that rotates desired wavelengths of light to a particular polarization state, a second retarder stack inverted and rotated by 90 degrees with respect to said first retarder stack, and a passive matrix addressed optical element positioned between the first and second retarder stacks. The retardation and orientation of each of the first retarder stack, second retarder stack, and passive matrix addressed optical element are optimized so as to provide a color generation stage that places desired wavelengths of light substantially along the transmission axis of the analyzer.