Photosensor controller for musical instrument having a driving means for driving a subsequent pair of luminescing means and detecting means in sequence
AssigneeYamaha Corporation
InventorRokurota Mantani
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Abstract
A photosensor controller is described comprising sensor units 17-0 to 17-7, 18-0 to 18-7, 19-0 to 19-7 and a circuit 16 driving light emitting diodes by a method of time division. Each sensor unit comprises pairs of an LED and a photodiode. After the driving circuit 16 turn on the proceeding LED, if turns off the next LED for a period corresponding to the delay time constant of a detected signal from a photodiode which corresponds to "OFF", making a completely to "0" in this off period of turning off, even in case of waveform rounding. Following this, the next LED is turned on.
Claims7
A photosensor controller for use in a musical instrument equipped with a plurality of elements for operation, comprising:
- a) a plurality of luminescing means for emitting light;
- b) a plurality of detecting means for detecting light emitted by said luminescing means, wherein each of said detecting means forms a pair with a respective one of said luminescing means for each of said elements, detecting the light emitted therefrom, and thereby detecting operations in said elements;
- c) a driving means for driving said pairs of luminescing means and detecting means in sequence wherein, said luminescing means is driven by said driving means for a first period of time and said detecting means scans said luminescing means during a portion of said first period of time, and, following elapse of said first time period, said luminescing means is extinguished, and after a second period of time said driving means drives a subsequent pair of said luminescing means and said detecting means in sequence.
A photosensor controller for use in a musical instrument equipped with a plurality of elements for operation, comprising:
- a) a plurality of luminescing means for emitting light;
- b) a plurality of detecting means for detecting light emitted by said luminescing means, wherein each of said detecting means forms a pair with a respective one of said luminescing means for each of said elements, detecting the light emitted therefrom, and thereby detecting operations in said elements;
- c) driving means for driving said pairs of luminescing means and detecting means in sequence wherein said luminescing means is driven for a first period of time and said detecting means scans said luminescing means during a portion of said first period of time, and, following elapse of said first time period, said luminescing means is extinguished and after a second period of time said driving means drives a subsequent pair of said luminescing means and said detecting means in sequence;
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- d) means for outputting a status variation signal when said detecting means detects a change in status of said luminescing means from a previous scan of said luminescing means;
- wherein an LED is utilized in said luminescing means and a photodiode is utilized in said detecting means, each anode of said photodiode being connected to a power source and each cathode of said photodiode being connected to a common terminal, said common terminal having an electric potential utilized as a detection signal of said detecting means.
Dependencies are inferred from the claim text.