Key input apparatus
First Claim
1. A key input apparatus with a plurality of key switches for outputting respective information, said key input apparatus comprising:
- a variable resistance circuit including a plurality of key units connected with each other in parallel and a pair of terminals, each key unit including a key switch and a resistance element connected with the key switch in series,a voltage generating unit including a power source connected with one terminal of said variable resistance circuit and a resistance element connected with said other terminal of said variable resistance circuit in series for generating an analog voltage corresponding to a resistance value of said variable resistance circuit, andan analog-to-digital converter for converting said analog voltage into a digital signal.
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Accused Products
Abstract
This invention relates to a key input apparatus used for inputting the information into various electronic equipments, such as a computer or a computer applied equipment, and the key input apparatus according to this invention has a variable resistance circuit which comprises a plurality of key switches and a plurality of resistance elements connected thereto and changes the resistance value thereof corresponding to the depressed key switch. The apparatus can generate analog voltage corresponding to the change in the resistance value and convert the analog voltage into a digital signal to thereby discriminate the depressed key switch on the basis of the output of the digital signal, whereby the number of signal conductors or terminals between the keyboard and the equipment to be inputted with information is reduced.
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Citations
19 Claims
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1. A key input apparatus with a plurality of key switches for outputting respective information, said key input apparatus comprising:
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a variable resistance circuit including a plurality of key units connected with each other in parallel and a pair of terminals, each key unit including a key switch and a resistance element connected with the key switch in series, a voltage generating unit including a power source connected with one terminal of said variable resistance circuit and a resistance element connected with said other terminal of said variable resistance circuit in series for generating an analog voltage corresponding to a resistance value of said variable resistance circuit, and an analog-to-digital converter for converting said analog voltage into a digital signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A key input apparatus with a plurality of key switches for outputting respective information, said key input apparatus comprising:
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a plurality of input units, each of the input units comprising a key switch element and a resistance element connected with the key switch element in series, the input units connected with each other in parallel between a first bus-bar applied with a constant voltage and a second bus-bar having an output terminal, and an analog-to-digital converter for converting analog voltage outputted from said output terminal into digital values. - View Dependent Claims (10, 11)
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12. A key input apparatus with a plurality of key switches for outputting respective information. said key input apparatus comprising:
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A plurality of input units, each of the input units including a key switch element, a resistance element connected with the key switch element in series, and two plug members connected to both ends of the series circuit of the key switch element and the resistance element, respectively, said resistance element of each input unit having a different resistance value from each other, and a keyboard body including a first bus-bar capable of applying a constant voltage, a second bus-bar having an output terminal outputting analog voltage corresponding to an operation of the key switch elements, and a plurality of connectors arranged on said first and second bus-bars so as to connect said two plug members of each of said input units with the first and second bus-bars, respectively, wherein the input units can be arbitrarily arranged on the keyboard body.
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13. An improved keyboard assembly that can be modified to comply with a subjective requirement of a user so that an information processing unit can be responsive to a range of input data from individual key members that is greater than the number of key positions on the keyboard assembly, said assembly comprising:
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a keyboard housing member providing a predetermined number of key positions for key members, each position providing an electrical connection controlled by a key number and permitting removable attachment to a key member; a plurality of key members of greater number than the key positions; means on each key member for enabling a detachable connection to at least one key position, and means on each key member for enabling a unique electrical signal when operated by the user, whereby the electrical signal is representative of input data to the information processing unit and the keyboard housing member can receive subjectively determined key members in any one of its key positions to provide a specific range of input data as subjectively required for operation of the information processing unit. - View Dependent Claims (14, 15, 16, 17)
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18. An improved keyboard assembly that can be modified to comply with a subjective requirement of a user so that an information processing unit can be responsive to a range of input data from individual key members that is greater than the number of key positions on the keyboard assembly, said assembly comprising:
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a plurality of key members; a keyboard housing member providing a predetermined number of key positions for key members, each key position having an identical terminal connection and being interchangeable with another key position relative to the purpose of inputting information to the data processing unit and for providing an electrical connection controlled by a key member and permitting removable attachment to a key member; means on each key member for enabling a detachable connection to each key position, and means on each key member for enabling a unique electrical signal when operated by the user, whereby the electrical signal is representative of input data to the information processing unit and a common keyboard housing member can receive subjectively determined key members to provide a specific range of input data as subjectively required for operation of the information processing unit.
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19. In an improved keyboard assembly for a computer-based system having a keyboard housing member providing a predetermined number of key positions for key members, each key position providing an electrical connection that is common to output terminals of the keyboard for interconnection with the computer-based system, the improvement comprising:
a detachable key member having an exterior housing with an operable upper member responsive to activation by the user, a lower terminal connector assembly for detachable connection to any key position on the keyboard housing member and means, within the exterior key member housing, for enabling a unique electrical signal when the upper member is activated by the user, regardless of the specific key position connected to the lower terminal connectors, with the electrical signal transmitted to the output terminals for presentation to the computer-based system.
Specification