Abstract: Computer keyboard systems and methods of determining excessive keystroke force or overpressure are described. A computer keyboard system 10 is illustrated having a keyboard array of keys 14. Individual keys 14 are capable of being reciprocated through a keystroke range which comprises an undepressed position and an actuation position. The keystroke range may also include an overtravel subrange. Individual keys 14 are operatively connected with individual keyswitches 32 which are activated thereby for providing informational signals to a keyboard microprocessor 54, 56. The microprocessor is configured to determine a keyswitch closure duration value and compare that value with a predetermined threshold duration value. If the closure duration value is greater than the predetermined threshold duration value, then an overpressure signal is produced which enables a sensory warning device 50, 52 to warn the keyboard operator that excessive force has been applied.

Abstract: A computer keyboard 10 having a plurality of keys 18 at desired locations being supported above a support plate 20 having a plurality of apertures 22 at the desired locations. A membrane keyswitch assembly 24 is mounted on the support plate 20 having keyswitches at each desired location. The keys have key plungers 28 that move up and down in the support plate apertures 22. An elastomeric dome sheet 46 is mounted over the membrane keyswitch assembly 24 with individual elastomeric dome return springs for biasing the keys 18 to their up position. An air chamber 52 is formed beneath the support plate 20 extending between the desired key locations. An air-impervious elastomeric membrane 60 is sandwiched between the air chamber 52 and the support plate 20 forming a flexible upper wall that receives and engages the key plungers 28. The membrane 60 has individual pedestal portions at the key locations for engaging the plungers 28.

Abstract: A low cost self-leveling keyswitch 10 having a keytop 32 with an elongated keycap 34 that extends in a major direction. The keytop 32 has an off-set keystem 36 that is slidably mounted in a keystem bearing 26. The keytop 32 has a self-leveling projection 42 that extends downward, spaced from the keystem 36. Both the keystem 36 and the projection 42 are on opposite sides of the central axis 33 and engage an elongated plateau portion 66 of an elastomeric dome return spring 60. The elongated direction of the plateau portion is the same as the elongated direction of the keycap 34. The elongated dome return spring 60 in conjunction with the self-leveling protection 42 minimize any wobble or tilting of the keytop 32 as the keytop 32 is depressed independently of the location of the depression force. The effective size of the projection 42 is preferably more than 50% of the effective area of the elongated dome return spring 60.

Abstract: A computer keyboard 10 has a plurality of keys 24 with each key 24 having a membrane keyswitch 30. Each keyswitch 30 has a lower membrane layer 32 with a printed circuit having switch contacts 42 printed on an upper side thereon within a switch contact area. An upper membrane layer 36 is provided having a printed circuit thereon with switch contacts 46 printed on a lower side thereon within the switch contact area and in actuation alignment with switch contacts 42. Dielectric pads 50 are printed over parts of the switch contact area forming dielectric mounds between switch contact segments. Stress concentration pads 54 are printed on the upper side of the upper layer 36 spaced intermediate the dielectric pads 54 for causing the upper layer 36 to deflect between the dielectric pads 50 to bring portions of the switch contacts 46 into contact with the switch contacts 42.

Abstract: A computer keyboard with multiple rows of cantilevered keys which are flexibly attached to first common mounting strips. The keyboard also has multiple rows of cantilevered sub-members flexibly attached to second common mounting strips, with the sub-members being aligned beneath associated keys. The cantilevered sub-members are in sliding contact with their associated cantilevered keys and induce a tactile "break over" sensation as the associated cantilevered keys are depressed. Each sub-member is designed to actuate a switch contact as the cantilevered key is depressed, whereby the computer keyboard can be constructed without a dome sheet.

Abstract: A cursor control device includes a single key cursor control which utilizes pressure sensitive resistors for controlling cursor movement. Pressure sensitive resistors are arrayed so as to provide an output corresponding to the magnitude and direction of an applied input pressure. Input pressure is transmitted to these resistors by a means for actuating these devices. The means for actuating can include a single key which incorporates functionality of both up, down, left and right cursor control keys and pointing devices to produce horizontal, vertical, diagonal and curvilinear cursor movement. Cursor control device offers mechanically simple, low cost construction, and can be incorporated onto many keyboard constructions. Cursor control device can be positioned on keyboards in many locations as best suits individual applications. Cursor control device can also be incorporated into other devices which require cursor control such as electronic mice.

Abstract: A two-layer membrane switch particularly suited for application as a keyswitch in low-profile keyboard applications, such as keyboards for notebook or laptop type personal computers. When used as a keyswitch, the switch comprises a first conductor layer including a conductive ink patterned as an electrical contact on a polyester dielectric film around an opening through the film. A second conductor layer, also includes a conductive ink patterned as an electrical contact on a polyester dielectric film. With the electrical contact of the second conductor layer located under the corresponding opening in the first conductor layer, a moveable, conductive elastomer switch closure is used to establish electrical contact between the electrical contact of the first conductor layer and the electrical contact of the second conductor layer through the opening in the first conductor.

Abstract: A computer keyboard has multiple rows of cantilevered keys which are flexibly attached to common mounting strips. The rows of cantilevered keys are arranged to partially overlap adjacent rows such that the keys in one row actuate switch contacts aligned beneath mounting strips in the adjacent row. An interface between the switch contact membrane and a printed circuit board, and employing a portion of the dome sheet as supporting legs for the keyboard, are also described.

Abstract: An improved alphanumeric keyboard 10 is illustrated for use in lap top or notebook personal computers 12. The keyboard 10 has a plurality of full travel, self leveling keyswitches 14 for actuating printed circuit electrical contacts 22 and 26 when the keyswitch is depressed. The keyboard 10 includes an integral keyswitch structure 40 that has an integral keytop 42 and keytop support substructure 44 supported on a common integral base sheet 46. Each of the keytop support substructures 44 includes hinge members 50a50b, 50c and 50d that are positioned in a rectangular orientation about the keytop 42. Each hinge member has a rigid upper hinge panel 52 and a lower hinge panel 58 that are integrally interconnected to the keytop 42 and the base sheet 46 for maintaining the keytop in a parallelogram orientation as it is depressed to prevent the keytop from moving laterally or wobbling during depression. The hinge panels 52 and 58 are interconnected by resilient webs 54, 60 and 64.

Abstract: A leveler suitable for use in multi-unit keys for a keyboard, such as a notebook keyboard, includes a J-shaped cantilever member interposed between a keycap and a base used to house the keycap. The leveler is rotatably attached to the keycap and rotatably and slidably engaged with the base. Upon actuation of the key, the slidable and rotatable portion permits the key to be compressed, while the rotatable portion attached to the keycap provides, through the action of the cantilever, a downward force upon the lower surface of the keycap. The distribution of this force via the cantilever mechanism provides a key leveling function, such that the keycap does not have a tendency to bind or stick within the guide portion of the base.

Abstract: A computer keyboard has multiple rows of cantilevered keys which are flexibly attached to common mounting strips. The rows of cantilevered keys are arranged to partially overlap adjacent rows such that the keys in one row actuate switch contacts aligned beneath mounting strips in the adjacent row. An interface between the switch contact membrane and a printed circuit board, and employing a portion of the dome sheet as supporting legs for the keyboard, are also described.

Abstract: An improved alphanumeric keyboard 10 is illustrated for use in lap top or notebook personal computers 12. The keyboard 10 has a plurality of full travel, self leveling keyswitches 14 for actuating printed circuit electrical contacts 22 and 26 when the keyswitch is depressed. The keyboard 10 includes an integral keyswitch structure 40 that has an integral keytop and keytop support substructure 44 supported on a common integral base sheet 46. Each of the keytop support substructures 44 includes hinge members 50a, 50b, 50c and 50d that are positioned in a rectangular orientation about the keytop 42. Each hinge member has a rigid upper hinge panel 52 and a lower hinge panel 58 that are integrally interconnected to the keytop 42 and the base sheet 46 for maintaining the keytop in a parallelogram orientation as it is depressed to prevent the keytop from moving laterally or wobbling during depression.

Abstract: A computer keyboard according to a preferred construction has multiple non-conductive keys and at least one conductive key mounted in a keyboard housing. The conductive key includes a molded plastic key body having conductive material embedded therein. Conductive plugs are electrically coupled and mounted to the conductive key body. An electrostatic discharge pad is provided on a switch assembly positioned beneath the keys of the keyboard. The discharge pad is coupled to ground through a path resistor. When the conductive key body is depressed to an activated position, the plugs engage the electrostatic discharge pads so that electrostatic charges of the user progressively dissipate to ground through the key body, plug, discharge pad, and path resistor. At least one of the path resistor or the plug has a resistance greater than the resistance of the conductive key body.

Abstract: A computer keyboard has multiple rows of cantilevered keys which are flexibly attached to common mounting strips. The rows of cantilevered keys are arranged to partially overlap adjacent rows such that the keys in one row actuate switch contacts aligned beneath mounting strips in the adjacent row. Each cantilevered key has an elongated member extending between a common mounting strip and a key cap, whereby the elongated members are wider at the point of attachment to the common mounting strips than at a point adjacent to the key cap.

Abstract: A data input monitor for use with a data input device, such as a computer keyboard, measures the amount of data entered into a computer and establishes intermittent rest periods based on the measured data amount. The data input device includes a display for informing a user when to rest during the rest periods. The data input monitor includes in one embodiment a microprocessor programmed to count the number of keystrokes entered on the computer keyboard and to compute an actual input rate that data is entered into the computer. This actual input rate is then compared to a stored predefined input rate, and used to compute an actual rest period. The data input monitor uses LEDs to inform a user when to work and when to rest. A method for managing user work pace on a computer keyboard is also described.

Abstract: A computer keyboard employs a single monoblock structure to both support the keys and to define the aesthetic enclosure. The monoblock has multiple key supports into which key bodies are slidably mounted. The keyboard includes a switch membrane disposed on top of the monoblock and a dome sheet positioned on top of the switch membrane beneath the key bodies. The dome sheet has multiple resilient domes with openings formed therein to provide access for the key bodies to corresponding key supports. The domes support the key bodies and provide the "spring-like" feel during operation of the computer keys. The switch membrane has annular switch contacts positioned about the monoblock key supports beneath the domes. As one of the key bodies is depressed, the associated dome buckles and actuates the annular switch contact. The computer keyboard is low cost due to having only one structural component and is quiet due to the position of the rubber or elastomer dome sheet beneath the key bodies.

Abstract: A cursor movement control key and electronic keyboard for a computer having a video display incorporates a force-sensitive resistor having a junction resistance which varies inversely with pressure applied thereto. The external key cap engages an actuator which bears against the force-sensitive resistor. The actuator has a plurality of four pads which bear against respective electrode regions of the force-sensitive resistor. The pads are positioned at the 0.degree., 90.degree., 180.degree., and 270.degree. positions. The actuator mounts relative to a keyboard mounting plate. At least one of the actuator and mounting plate include opposed lateral projections which engage relative to the other of the actuator and mounting plate to both, a) retain the actuator to the mounting plate, and yet b) allow clearance for tilting movement of the actuator relative to the mounting plate.

Abstract: As a preferred embodiment, a computer keyboard dome sheet is illustrated in the figures showing a extruded sheet 30 with an elongated body 32 with parallel extruded ridges 44 corresponding to the keyboard rows 16a-16f. Apertures or cutouts are formed in the ridges 46 at desired intervals between the key positions to form individual ridge domes 48 having parallel front and rear walls 54 and 56 that are collapsible to bring a switch actuating keel 66, 92 into engagement with the switch structure to actuate an electrical switch to indicate that the key switch has been depressed.

Abstract: Excess clearance provided between a multi-wide keytop and a rigid supporting housing layer is removed by provision of yieldable projections that extend upwardly beyond the housing layer and engage the movable leveling bar. The projections are formed integrally with an underlying dome sheet of elastomeric material and protrude through complementary openings formed through the housing layer.