Abstract:
The switch includes a printed circuit, of generally plane shape, and comprising a first face bearing a first contact pad, a second face, opposite the first, bearing a second contact pad, and a through-orifice allowing access between the first face and the second face. The switch also includes a conductor, having a first part, which cooperates with the first contact pad, and a second part, which extends between a first end, fixed to the first part, and a free second end, passing through the orifice. The second part is elastically deformable between a rest position, in which its second end cooperates with the second contact pad, and a stressed position, in which its second end is moved away from the second contact pad.
Abstract:
A key input device including a plurality of keytops, with an elastic member being disposed between each keytop and a printed circuit board so as to be supported at a lower end portion thereof by an upper surface of the printed circuit board and pushed upwardly to cause the keytop to be biased upwardly. An engaging portion, provided on a main body of each keytop, prevents the keytop from coming out of a hole accommodating the respective keytops. The depressing stroke of the respective keytops can be defined by an upper casing an the printed circuit board regardless of the state of elastic deformation of the elastic member. An insulating substrate may be provided on the printed circuit board, with printed electrodes being formed on an upper surface of the insulating substrate in an opposed relationship to the keytops in such a manner that, when one of the keytops is depressed, the printed electrodes are brought into contact with the contact electrodes corresponding to the depressed keytop. Printed wiring conductors or strips can be formed on the upper surface of the printed circuit board on which the printed electrodes for the keytop switches are formed. The circuit elements or electronic components, connected through the printed wiring conductors or strips, can be mounted on the lower surface side of the printed circuit board resulting in a common printed circuit board for holding the keytop switches and the mounting of the electronic components.
Abstract:
A binary code generator for generating a plural bit binary code from keyboard input data comprises a printed circuit including a plurality of conductive lead groupings arranged in registration with a plurality of pushbuttons on a keyboard frame. The circuit board includes a plurality of electrical terminals one of which is operatively electrically connected to a voltage source and the others of which are selectively operatively electrically connected to the lead patterns forming the conductive lead groupings in accordance with the binary code to be generated. Upon actuation of the pushbutton switch all of the lead patterns in the conductive lead grouping associated with that pushbutton are electrically connected together whereby selected ones of the output terminals are electrically connected to the voltage source thereby to produce a binary output code. The keyboard is formed of a single integral sheet of resilient material and includes a plurality of conductive resilient contacts normally spaced from the conductive lead groupings on the circuit board. In a preferred embodiment each of the lead patterns in a lead grouping comprises a plurality of radially extending branches and the contact member is formed with a contact surface in the form of a continuous generally circular rim adapted upon depression of its associated pushbutton to bridge a sufficient number of lead branches in the associated lead grouping to provide effective and reliable switching under all conditions. The contacts are electrically and structurally separated from each other by raised strips formed integral on the resilient keyboard sheet and secured by appropriate means to the circuit board, those strips being effective to reliably maintain independent actuation of individual pushbuttons.
Abstract:
An encoded keyboard device which includes a plurality of layers of insulator material, at least two of which have patterns of electrically conductive material supported thereby, a plurality of holes extending through one of said layers and positioned with respect to said conductive patterns so that electrically conductive material may extend through the holes and electrically interconnect the patterns, and a plurality of keys adapted to push electrically conductive material against one of said patterns to produce a coded output representative of the key depressed.
Abstract:
Architecture for a keyboard that supports the n-key rollover feature, while being compatible with well established, high volume, inexpensive manufacturing techniques. The design is a matrix design that uses resistors at each key rather than diodes, and employs novel circuits which allow any combination of simultaneous key presses to be detected using this resistive matrix. The resistors can be screen printed on the flexible sheets in a manner similar to the conductors. A resistive keyboard matrix employs circuit techniques that eliminate phantom key presses. The resistors can be created by screen-printing carbon ink. Additionally, various implementations of the decoder circuits can be employed to provide the n-key rollover feature on flexible sheets for inexpensive production.
Abstract:
The frequency capability of a planar multiple switch for entry of digital data is improved by forming an upper conductive planar member from fine conductive elements electrically joined, such as a screen or conductor pattern, together but with sufficient space between elements to substantially reduce capacitive coupling between the upper member and lower contact members. Further, multiple bit switch areas are formed adjacent single bit switch areas; and coded contact areas are formed on parallel lines by placing insulation on selected sections of lines and building up adjacent contact sections by additional conductor material.
Abstract:
A membrane switch in which a membrane layer is supported in a spaced relation from at least one contact of one or more pairs of electrically conductive switch contacts. The contacts are mounted on an insulated substrate. The membrane surface adjacent the contacts has an electrically conductive bridging surface supported thereon such that depression of the membrane will bridge the contacts to complete a circuit. The membrane is mounted on the substrate and is held in a normally spaced relationship with the contacts by a plurality of projections formed on the membrane surface adjacent the substrate or one or more of the contact surfaces. The projections may be integrally formed by puncturing the membrane surface with a sharp object or projections may be formed by permanently deforming the membrane without rupturing the membrane itself. Additionally, the projections may be formed by applying individual spacer elements to the membrane surface.
Abstract:
A keyboard device utilizing a conductive plastic material layer which contacts circuit elements or pathways, the improvement of snapable plastic means raised on a pedestal through which it snaps through center to provide a feel of completion of circuit contact to the user.
Abstract:
In a mechanically operated keyboard employing keys each having a multiplicity of electrical switch contacts for providing an encoded electrical signal output corresponding to and uniquely identifying individual key stations, an electrical circuit provides a dummy load across the multiple switch contacts which varies as different keys are actuated in a manner to provide a constant load across the multiple switch contacts. The electrical circuit develops a control signal which can be employed in conjunction with associated circuits to inhibit erroneous data output signals from the keyboard in the event of improper switch closure.
Abstract:
A key device for a computer keyboard has a rigid printed circuit board, a flexible printed circuit board, and a key structure. The rigid printed circuit board has two adjacent but unconnected conductive ends electrically connected to two wires respectively. The flexible printed circuit board, fixed over the rigid printed circuit board, has a conductive segment installed above the two conductive ends, and an isolation layer installed around the conductive segment to form a gap between the conductive segment and the two conductive ends. The key structure is moveably fixed on the flexible printed circuit board in an up and down manner. When the key structure is pushed downward, the bottom of the key structure will touch the conductive segment of the flexible printed circuit board, and the conductive segment will touch the two conductive ends of the rigid printed circuit board to electrically connect the two conductive ends and the two wires.