Abstract: Method and system for activating at least one of a display screen and a touch screen, and/or for deactivating a power conservation system for a hand held computing device (PDA, radiotelephone, etc.), when a stylus used for the touch screen is absent from a receptacle that receives the stylus on the device. When the stylus is present in the receptacle, the display screen and/or touch screen are deactivated and/or the power conservation system is activated. When the stylus is absent from the receptacle, but an accumulated time for such absence is greater than a selected time-out value, the system reacts as if the stylus is present in the receptacle. Examples of methods of sensing presence or absence of a stylus in a stylus receptacle are presented.

Abstract: Method and system for simultaneous display of standard text characters and hand entered characters in a designated soft write pad portion of a hand held device display screen. When a hand entered character is entered on the soft write pad, standard text on the soft write pad is displayed in a display pattern (color and/or shading and/or thickness and/or font) that is visually distinguishable from a display pattern used for (temporary) display of the hand entered character. The hand entered character is analyzed and, if recognized, is converted to a standard text character and displayed at a location indicated by a cursor. The display pattern of standard text character and/or hand entered characters can be changed by the user. Display of a hand entered character on the soft write pad terminates after a designated time interval.

Abstract: Method and system for determining (x,y) location coordinates for a contact point on a touch sensitive panel or input screen. Selected, substantially constant voltages are provided for two electrodes that are part of the input screen, from one voltage source. A current value is measured for one resistive line segment that extends from the contact point to one of the electrodes, and the voltage at the contact point is measured. Resistance values for at least two of the four resistive lines that extend from the contact point to the electrodes are calculated or estimated, and (x,y) location coordinates are estimated for the contact point from these resistance values. The invention uses two measurements and two non-switched voltage sources to provide the (x,y) coordinates.

Abstract: Apparatus for a touch sensitive panel or input screen for a hand held computing device that provides increased active or key area for the input screen. Four wires, each connected to one of the electrodes, are divided into smaller two-wire and one-wire units, with two of the four wires being connected to a signal processor from opposed locations on a boundary of the input screen. Replacing a conventional four-wire unit with this arrangement, the active or key area on the input screen can be increased by as much as 10-14 percent on a typical hand held device, or one or more dimensions of the device housing can be reduced. The four wire connection may be replaced by a three wire connection.

Abstract: Method and system for activating at least one of a display screen and a touch screen, and/or for deactivating a power conservation system for a hand held computing device (PDA, radiotelephone, etc.), when a stylus used for the touch screen is absent from a receptacle, that receives the stylus on the device. When the stylus is present in the receptacle, the display screen and/or touch screen are deactivated and/or the power conservation system is activated. When the stylus is absent from the receptacle, but an accumulated time for such absence is greater than a selected time-out value, the system reacts as if the stylus is present in the receptacle. Examples of methods of sensing presence or absence of a stylus in a stylus receptacle are presented.

Abstract: Method and system for determining (x,y) location coordinates for a contact point on a touch sensitive panel or input screen. Selected, substantially constant voltages are provided for two electrodes that are part of the input screen, from one voltage source. A current value is measured for one resistive line segment that extends from the contact point to one of the electrodes, and the voltage at the contact point is measured. Resistance values for at least two of the four resistive lines that extend from the contact point to the electrodes are calculated or estimated, and (x,y) location coordinates are estimated for the contact point from these resistance values. The invention uses two measurements and two non-switched voltage sources to provide the (x,y) coordinates.

Abstract: Apparatus for a touch sensitive panel or input screen for a hand held computing device that provides increased active or key area for the input screen. Four wires, each connected to one of the electrodes, are divided into smaller two-wire and one-wire units, with two of the four wires being connected to a signal processor from opposed locations on a boundary of the input screen. Replacing a conventional four-wire unit with this arrangement, the active or key area on the input screen can be increased by as much as 10-14 percent on a typical hand held device, or one or more dimensions of the device housing can be reduced. The four wire connection may be replaced by a three wire connection.