Keyboard encoding
First Claim
1. A method of encoding the activation of a switch of a group of switches, the switches being designated by respective X,Y locations, and each of the switches having a first terminal designated by the X location thereof, and a second terminal designated by the Y location thereof, comprising the steps of:
- activating a switch;
energizing the first terminals of the switches to energize the second terminal of the activated switch;
monitoring the second terminals of the switches to identify from the energized second terminal a Y location of the activated switch;
energizing the second terminals of the switches designated by the identified Y location to energize the first terminal of the activated switch; and
monitoring the first terminals of the switches to identify from the first terminal energized in the second terminals energizing step an X location of the activated switch.
2 Assignments
0 Petitions
Accused Products
Abstract
A keyboard interface controller in the nature of a state machine is placed in a stop mode or an idle mode after initialization. In stop or idle mode, all the keyboard conductors associated with the X-axis are activated, while all keyboard conductors associated with the Y-axis are sensed. Upon being awakened by an interrupt upon key closure from which the Y-axis location of the closed key is determined, the controller sequences through the steps of (a) determining the X-axis of the keyboard by activating the determined Y-axis conductor and sensing the X-axis conductors; (b) converting the crosspoint to a unique code; (c) transmitting the crosspoint code to the host; and (d) checking for either another closure or the release of the closure detected. When all keys are released, the controller returns to stop or idle mode.
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Citations
36 Claims
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1. A method of encoding the activation of a switch of a group of switches, the switches being designated by respective X,Y locations, and each of the switches having a first terminal designated by the X location thereof, and a second terminal designated by the Y location thereof, comprising the steps of:
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activating a switch; energizing the first terminals of the switches to energize the second terminal of the activated switch; monitoring the second terminals of the switches to identify from the energized second terminal a Y location of the activated switch; energizing the second terminals of the switches designated by the identified Y location to energize the first terminal of the activated switch; and monitoring the first terminals of the switches to identify from the first terminal energized in the second terminals energizing step an X location of the activated switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An interface controller for a keyboard having a plurality of keys arranged conceptually on a grid of X-designated conductors and Y-designated conductors, each key being at a crossing of an X-conductor and a Y-conductor and having one terminal connected to the X-conductor and another terminal connected to the Y-conductor, comprising:
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a plurality of controllable driver-sense circuit pairs respectively associated with the X-conductors of the keyboard; a plurality of controllable driver-sense circuit pairs respectively associated with the Y-conductors of the keyboard; and control logic coupled to the driver-sense circuit pairs respectively associated with the X-conductors and Y-conductors for activating the drivers associated with the X-conductors and the sense circuits associated with the Y-conductors to identify a Y-conductor that is connected to a closed key, and for activating the driver associated with the identified Y-conductor and the sense circuits associated with the X-conductors to identify an X-conductor that is connected to the closed key. - View Dependent Claims (12, 13, 14, 15)
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16. A method of encoding the activation of a switch of a group of switches, the switches being designated by respective X,Y locations, and each of the switches having a first terminal designated by the X location thereof, and a second terminal designated by the Y location thereof, comprising the steps of:
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placing a first signal on the first terminals of the switches; monitoring the second terminals of the switches to detect the first signal, the detected first signal identifying a Y location of an activated switch; placing a second signal on the second terminals of the switches designated by the identified Y location; and monitoring the first terminals of the switches to detect the second signal, the detected second signal identifying an X location of the activated switch. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of identifying an activated switch in a group of switches wherein each switch is individually associated with one of a plurality of column conductors and one of a plurality of row conductors, comprising the steps of:
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placing a first signal on the column conductors, wherein the first signal is communicated to a first one of the row conductors through a first activated switch; sensing the first signal on the first row conductor; placing a second signal on the first row conductor in response to the sensing step, wherein the second signal is communicated to a first one of the column conductors through the first activated switch; and sensing the second signal on the first column conductor. - View Dependent Claims (26, 27, 28, 29, 30)
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31. A method of encoding the activation of a switch of a group of switches arranged on a keyboard wherein the switches are coupled to a plurality of first conductors and second conductors, each of the switches being coupled between a respective different pair of the first conductors and the second conductors, comprising the steps of:
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placing a first signal on the first conductors, wherein the first signal is communicated through a first activated switch to a second conductor coupled to the first activated switch; monitoring the second conductors to detect the first signal, the detected first signal identifying the second conductor coupled to the first activated switch; placing a second signal on the identified second conductor coupled to the first activated switch, wherein the second signal is communicated through the activated switch to a first conductor coupled to the first activated switch; and monitoring the first conductors to detect the second signal, the detected second signal identifying the first conductor coupled to the first activated switch. - View Dependent Claims (32, 33, 34, 35, 36)
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Specification