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US 8,525,722 B2Granted
Ad converting device, dial-type input device, and resistance-voltage conversion circuit
AssigneeRicoh Company, Ltd.
InventorsToshiro Yasuda, Makoto Hangaishi
Life of this patent
Estimating the term…
Abstract
An AD converting device includes a resistance-voltage conversion circuit which changes a first integrated voltage in proportion to a product of a varied resistance of a variable resistance and an electrical current applied to the variable resistance and changes a second integrated voltage and a reference voltage in proportion to a product of a total resistance of the variable resistance and the electrical current.
Claims9
An AD converting device comprising:
- a double integral AD converter having
- an integrator which
- when a first integrated voltage is input to the integrator, performs a first integration in which a difference between the first integrated voltage and a reference voltage is integrated,
- after the first integration is performed and when a second integrated voltage is input to the integrator, performs a second integration in which a difference between the second integrated voltage and the reference voltage is integrated, and
- outputs an integrated voltage according to at least the second integration;
- and
- an output part which receives the integrated voltage output from the integrator and the reference voltage, counts time from when the second integration is started to when the integrated voltage becomes equal to the reference voltage, and outputs the counted time as a digital value;
- a variable resistance;
- and
- a resistance-voltage conversion circuit which changes the first integrated voltage in proportion to a product of a resistance value of the variable resistance after being varied in the variable resistance and a value of an electrical current applied to the variable resistance and changes the second integrated voltage and the reference voltage in proportion to a product of a total resistance value of the variable resistance and the electrical current applied to the variable resistance.
7 more elements
A resistance-voltage conversion circuit which is connected to a variable resistance and an AD converting device having;
- a double integral AD converter having
- an integrator which
- when a first integrated voltage is input to the integrator, performs a first integration in which a difference between the first integrated voltage and a reference voltage is integrated,
- after the first integration is performed and when a second integrated voltage is input to the integrator, performs a second integration in which a difference between the second integrated voltage and the reference voltage is integrated, and
- outputs an integrated voltage according to at least the second integration;
- and
- an output part which receives the integrated voltage output from the integrator and the reference voltage, counts time from when the second integration is started to when the integrated voltage becomes equal to the reference voltage, and outputs the counted time as a digital value, the resistance-voltage conversion circuit comprising
- a voltage output part generating and outputting the first integral voltage based on a resistance value of the variable resistance and generating and outputting the second integrated voltage and the reference voltage;
- and
- a resistance-voltage conversion part which changes the first integrated voltage in proportion to a product of a resistance value of the variable resistance after being varied in the variable resistance and a value of an electrical current applied to the variable resistance and changes the second integrated voltage and the reference voltage in proportion to a product of a total resistance value of the variable resistance and the electrical current applied to the variable resistance.
7 more elements
Dependencies are inferred from the claim text.