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US 2018/0324522 A1Published application
Sound pressure gradient microphone
AssigneePanasonic Intellectual Property Management Co., Ltd.
InventorMAKOTO TAKEMOTO
Life of this patent
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Abstract
A sound pressure gradient microphone includes: a first non-directional microphone; a second non-directional microphone; a delay device that receives an output of the second non-directional microphone; and a subtractor that receives an output of the first non-directional microphone and an output of the delay device. The subtractor outputs a difference between the output of the first non-directional microphone and the output of the delay device. A phase of the first non-directional microphone is ahead of a phase of the second non-directional microphone.
Claims7
A sound pressure gradient microphone comprising:
- a first non-directional microphone having a first phase;
- a second non-directional microphone having a second phase;
- a delay device that receives an output of the second non-directional microphone;
- a subtractor that receives an output of the first non-directional microphone and an output of the delay device, and outputs a difference between the output of the first non-directional microphone and the output of the delay device,
- wherein the first phase is ahead of the second phase.
2 more elements
A sound pressure gradient microphone comprising:
- a first non-directional microphone;
- a second non-directional microphone;
- a first high-pass filter that receives an output of the first non-directional microphone;
- a second high-pass filter that receives an output of the second non-directional microphone;
- a delay device that receives an output of the second high-pass filter;
- and
- a subtractor that receives an output of the first high-pass filter and an output of the delay device, and outputs a difference between the output of the first high-pass filter and the output of the delay device,
- wherein the first high-pass filter includes a first capacitor which is disposed between the first non-directional microphone and the subtractor, and is connected in series to the first non-directional microphone and the subtractor,
- the second high-pass filter includes a second capacitor which is disposed between the second non-directional microphone and the delay device, and is connected in series to the second non-directional microphone and the delay device, and
- a capacitance value of the first capacitor is smaller than a capacitance value of the second capacitor so as to achieve a state where a phase of a signal output from the first high-pass filter is ahead of a phase of a signal output from the second high-pass filter.
7 more elements
A sound pressure gradient microphone comprising:
- a first non-directional microphone;
- a second non-directional microphone;
- a first high-pass filter that receives an output of the first non-directional microphone;
- a second high-pass filter that receives an output of the second non-directional microphone;
- a delay device that receives an output of the second high-pass filter;
- and
- a subtractor that receives an output of the first high-pass filter and an output of the delay device, and outputs a difference between the output of the first high-pass filter and the output of the delay device,
- wherein the first high-pass filter includes a first capacitor and a first resistor, the first capacitor is disposed between the first non-directional microphone and the subtractor and is connected in series to the first non-directional microphone and the subtractor, and the first resistor has a grounded first end and a second end connected to a line between the first non-directional microphone and the subtractor,
- the second high-pass filter includes a second capacitor and a second resistor, the second capacitor is disposed between the second non-directional microphone and the delay device and is connected in series to the second non-directional microphone and the delay device, and the second resistor has a grounded first end and a second end connected to a line between the second non-directional microphone and the delay device, and
- a resistance value of the first resister is smaller than a resistance value of the second resistor so as to achieve the state where a phase of a signal output from the first high-pass filter is ahead of a phase of a signal output from the second high-pass filter.
7 more elements
A sound pressure gradient microphone comprising:
- a first non-directional microphone;
- a second non-directional microphone;
- a first digital filter that receives an output of the first non-directional microphone;
- a second digital filter that receives an output of the second non-directional microphone;
- a delay device that receives an output of the second digital filter;
- and
- a subtractor that receives an output of the first digital filter and an output of the delay device, and outputs a difference between the output of the first digital filter and the output of the delay device,
- wherein the first and second digital filters are set so as to achieve the state where a phase of a signal output from the first digital filter is ahead of a phase of a signal output from the second digital filter.
5 more elements
Dependencies are inferred from the claim text.