Abstract: A computer system employs a keyboard that includes an integrated pointing device coupled to a pointing key. The system has a typing mode of operation and a pointing mode of operation. In the pointing mode, the pointing key is used to enter pointing information, thereby obviating a discrete pointing device such as a mouse. The system may be switched between the typing mode and the pointing mode explicitly by predetermined commands. Alternatively, the system may be switched into the pointing mode implicitly by monitoring and timing keyboard events following a pointing key press.

Abstract: In a cursor tracking system (FIG. 11), a pointing device includes a plurality of force sensors (304), optionally integrated with a keyswitch on a computer keyboard. The force sensors detect lateral and vertical forces applied to the keycap (300) by a user (302) for cursor control. Raw force data is acquired by A/D apparatus (306) and transmitted (310,312) to a host processor. Driver level software in the host linearizes the raw force values (316, FIG. 12D) to compensate for anomolies and nonlinearities in the force sensors, keyboard mechanics, and A/D. The resulting linear force values are adjusted (320) to compensate for preloading bias forces (318) on the sensors. The unbiased, linear force values and sensor configuration (322) are used to determine a net XY vector (324, FIG. 16). A speed value is determined by a quadratic mapping of the XY vector magnitude (328), taking mouse button status into account.

Abstract: A miniature isometric joystick is disclosed for receiving manual user input to effect directional control such as controlling cursor movement on a computer display screen or controlling movement of an apparatus such as a machine or robot. The joystick is arranged to fit between the existing keys in a computer keyboard. The joystick includes a preloading spring for compressing the assembly together, thereby biasing the force sensors so as to neutralize manufacturing variations and control electrical and mechanical null zones. An integrated switch is provided in the joystick for detecting an external force applied by the user's fingertip. The switch unobtrusively detects when a user is pointing, thereby allowing a control system to measure pointing system bias signals while the user is not pointing. This permits the control system to automatically correct for drift, without requiring additional keyboard space for a separate switch to enable the pointing device.

Abstract: A pressure sensitive transducer array in which a plurality of transducers are connected in series and in parallel with one another. In one embodiment, a resistive layer is formed from carbon or silver ink on a polyester film. A plurality of conductive shunt elements having greater conductivity than the resistive layer is formed on a second polyester film. The films are placed adjacent to one another with the shunt elements contacting the resistive layer. Voltage is applied across the resistive layer and pressure is applied thereto. As the pressure increases, the number of current paths set up through contact points on the shunt elements increase thereby decreasing the resistance across the resistive layer and increasing current flow. In another embodiment a plurality of plate elements are contained in a plane on one side of a dielectric layer. A plurality of plate elements are contained in a plane on the other side of the dielectric layer.

Abstract: A pressure sensitive transducer array in which a plurality of transducers are connected in series and in parallel with one another. In one embodiment, a resistive layer is formed from carbon or silver ink on a polyester film. A plurality of conductive shunt elements having greater conductivity than the resistive layer is formed on a second polyester film. The films are placed adjacent to one another with the shunt elements contacting the resistive layer. Voltage is applied across the resistive layer and pressure is applied thereto. As the pressure increases, the number of current paths set up through contact points on the shunt elements increase thereby decreasing the resistance across the resistive layer and increasing current flow. In another embodiment a plurality of plate elements are contained in a plane on one side of a dielectric layer. A plurality of plate elements are contained in a plane on the other side of the dielectric layer.

Abstract: Apparatus for use in a computer keyboard for cursor control is disclosed. The apparatus includes a compound key which serves for both typing a character and for pointing operations, i.e. for cursor control like a mouse. For pointing operations, a pointing stick or shaft is pressed in a desired direction by a user for moving a cursor in a corresponding direction on a display screen. The pointing stick is disposed in an aperture that extends through a modified key cap, so that no additional keyboard space is required for the pointing device, thereby obviating a separate mouse, keyboard mounted trackball or the like. In an alternative embodiment, the pointing stick extends through an aperture in the keyboard space bar. In another embodiment, adjacent key caps are modified so as to fit closely around the key cap that houses the pointing stick without interfering with operation of either the pointing stick or the keyswiches.

Abstract: A miniature isometric joystick is disclosed for receiving manual user input to effect directional control such as controlling cursor movement on a computer display screen or controlling movement of an apparatus such as a machine or robot. The joystick is arranged to fit between the existing keys in a computer keyboard. The joystick includes a preloading spring for compressing the assembly together, thereby biasing the force sensors so as to neutralize manufacturing variations and control electrical and mechanical null zones. An integrated switch is provided in the joystick for detecting an external force applied by the user's fingertip. The switch unobtrusively detects when a user is pointing, thereby allowing a control system to measure pointing system bias signals while the user is not pointing. This permits the control system to automatically correct for drift, without requiring additional keyboard space for a separate switch to enable the pointing device.

Abstract: A keyswitch-integrated pointing assembly in which a plurality of substantially planar force sensing elements are disposed on a planar surface adjacent a keyswitch on a keyboard. The keyswitch includes a plunger which extends downwardly from a key cap for actuating a switch at the lower end of vertical key cap travel. The key cap engages an indexing surface when fully depressed which transmits force applied to the key cap to the force sensing elements. The force sensing elements are sandwiched between a pair of opposing plates thereby biasing the elements into a substantially linear operating region when no force is applied to the key cap.

Abstract: Methods and apparatus are disclosed for normalizing electronic sensor data to correct for variations in individual sensor transfer characteristics which are not known in advance. A general characteristic transfer function for a sensor type of interest is determined empirically. A baseline response reading is acquired from an individual sensor, and that baseline response applied to the general transfer function to determine a specific transfer function for the individual sensor. The specific transfer function is used to calculate normalized data. One application of the invention is in computer cursor control pointing devices such as a joystick. Because the invention compensates for wide variations in sensor characteristics, inexpensive sensors such as force-sensitive resistors may be used in a joystick without sacrificing pointing accuracy and ergonomic efficiency.