Abstract: In hardware, performing computations on a stream typically requires handshaking signals to provide flow control. Many different handshaking protocols are available, and they are typically implemented in an ad hoc manner suited to the current design. An approach according to the invention uses a subset of the possible flow-control protocols in an effort to achieve a maximum amount of flexibility and reusability, while requiring only a moderate level of overhead when compared to manually-designed systems.

Abstract: In hardware, performing computations on a stream typically requires handshaking signals to provide flow control. Many different handshaking protocols are available, and they are typically implemented in an ad hoc manner suited to the current design. An approach according to the invention uses a subset of the possible flow-control protocols in an effort to achieve a maximum amount of flexibility and reusability, while requiring only a moderate level of overhead when compared to manually-designed systems.

Abstract: Improvements in the art of sensor and display technology now make the implementation of a workpad concept feasible. While prior art touch displays are acceptable for short, casual use tasks, they may not be feasible or suited for intensive use tasks. Recent improvements in the optical qualities (brightness, contrast, viewing cone) of flat panel displays, such as LCDs, allow implementing a touch screen for use in a horizontal orientation. This greatly improves the human factors for applications involving extensive pointing, drawing, or writing.

Abstract: A stylus assembly in which a stylus is mounted in a housing for movement relative thereto. An electrical circuit is provided for sensing contact of the stylus with a writing surface and measuring the pressure exerted on the surface by the stylus.

Abstract: An improved touch overlay for the viewing surface of a display for detecting both finger touch and stylus location is disclosed. An upper and a lower set of transparent conductors are disposed on at least one transparent flexible insulating substrate and are oriented orthogonally with respect to each other. Depending on the orientation of the transparent conductors, top and bottom cover layers may be added to the overlay. The separation between the upper and lower conductors and a separation from the user's finger on the top surface of the overlay from the upper conductors is optimized. To speed finger touch sensing, the ambient capacitance of the overlay is reduced by increasing the separation between the upper and lower conductors layers. For improved operation, the present invention features a separation of at least 3 mils between upper and lower conductors.

Abstract: An architecture for communication of remote devices to a digitizing display includes a contact sensing mechanism and a position sensing mechanism whose outputs are multiplexed for transmission from the stylus to an antenna located proximate to the digitizing display. The digitizing display also includes a transmitter for transmitting information from a pen-based computer system to the stylus for storage or utilization in the stylus.

Abstract: A portable paperless parcel tracking system capable of reading bar codes on packages, capturing signatures and alphanumeric data related to the parcels when entered into a touch panel display, disabling manual or finger touch entry when a stylus is near the surface of the display, storing the parcel related data electronically and transmitting the data to a host at a convenient time.

Abstract: A data processing system is disclosed which is equipped with a secure user friendly input system. The input system comprises an array of horizontal and vertical conductor supported on a flexible, transparent overlay membrane secured to the viewing surface of the display of an individual workstation and a remotely sensed personal stylus. The stylus is equipped to receive electromagnetic signals from the array and transmit signals containing information concerning the stylus position on the overlay and stylus ID to a receiver at the workstation. The input system also includes a control processor operating in stored program instructions which control the detection and log-on procedures for the remotely sensed personal stylus.

Abstract: A combined finger touch and stylus detection system is disclosed for use on the viewing surface of the visual display device. Transparent conductors arranged in horizontal and vertical grid are supported on a flexible, transparent overlay membrane which is adaptable to a variety of displays. A unique interconnection pattern is provided between the transparent conductors in the array and buses which interconnect the conductors with the supporting electronics, whereby a minimum number of bus wires can be employed to service the array conductors and yet both unique finger touch location sensing and unique stylus location sensing can be accomplished. The system includes a control processor which operates on stored program instructions which, in a first embodiment provides for the alternate detection of either finger touch location or stylus location and, in a second embodiment, provides for the simultaneous detection of both finger touch location and stylus location.