Abstract: There are provided a piezoelectric body of ytterbium-doped aluminum nitride, having a greater piezoelectric coefficient d33 or g33 than those not doped with ytterbium, and a MEMS device using the piezoelectric body. The piezoelectric body is represented by a chemical formula Al1-xYbxN where a value of x is more than 0 and less than 0.37 and having a lattice constant ratio c/a in a range of 1.53 or more and less than 1.6. The piezoelectric body with such a configuration has a greater piezoelectric coefficient d33 or g33 than those not doped with ytterbium.

Abstract: Provided is a scandium-doped aluminum nitride with nitrogen polarity. The nitride material is represented by the chemical formula ScXMYAl1-X-YN. M is at least one or more elements among C, Si, Ge, and Sn, X is greater than 0 and not greater than 0.4, Y is greater than 0 and not greater than 0.2, and X/Y is less than or equal to 5. The nitride material has piezoelectricity with a polarization direction of nitrogen polarity opposite to the direction of thin film growth.

Abstract: An audio amplifier is provided with: an amplifier circuit; a power supply circuit that generates a plurality of power supply voltages; a power supply relay that selects one of the power supply voltages as the power supply voltage supplied to the amplifier circuit; a switching condition determiner that determines whether the switching condition of the power supply relay is satisfied; a silent section detector that detects a silent section of the audio signal which is equal to or greater than the operation time of the power supply relay; and a switching instruction unit for providing the power supply relay with an instruction for switching the power supply voltage during the silent section when the switching condition is satisfied and the silent section is detected.

Abstract: An audio amplifier is provided with: an amplifier circuit; a power supply circuit that generates a plurality of power supply voltages; a power supply relay that selects one of the power supply voltages as the power supply voltage supplied to the amplifier circuit; a switching condition determiner that determines whether the switching condition of the power supply relay is satisfied; a silent section detector that detects a silent section of the audio signal which is equal to or greater than the operation time of the power supply relay; and a switching instruction unit for providing the power supply relay with an instruction for switching the power supply voltage during the silent section when the switching condition is satisfied and the silent section is detected.

Abstract: In a sake/milk heating process, the field of view of an infrared sensor is moved by a predetermined pattern in a heating chamber as an initial search. When the field of view is fixed after the initial search, if the temperature variation of an object within the field of view after a predetermined time has passed is equal to or lower than a specified value, various determinations are made, and the field of view of the infrared sensor is again moved in the heating chamber as a re-search. Thus, even if the field of view is fixed at a position where no food item is placed for some reason in the initial search, the field of view will not be fixed in the incorrect position and can be moved again.

Abstract: In a sake/milk heating process, the field of view of an infrared sensor is moved by a predetermined pattern in a heating chamber as an initial search. When the field of view is fixed after the initial search, if the temperature variation of an object within the field of view after a predetermined time has passed is equal to or lower than a specified value, various determinations are made, and the field of view of the infrared sensor is again moved in the heating chamber as a re-search. Thus, even if the field of view is fixed at a position where no food item is placed for some reason in the initial search, the field of view will not be fixed in the incorrect position and can be moved again.

Abstract: In an echo effector for imparting an echo effect to an audio signal based on values of a plurality of parameters, a memory is provided for memorizing an interrelationship among the plurality of the parameters which are mutually related to each other. A dial is actuated for independently setting one or more of the parameters to desired values. A microcomputer dependently sets the remaining parameters to appropriate values according to the desired values and the memorized interrelationship. Further, in a sound field effector operative according to a selected program for creating an effect simulative of a sound field in matching with a room situation under which the effector is installed, a program memory stores a plurality of programs which can be selected in terms of types of sound fields and types of room situations. A first switch is operated for designating a desired type of a sound field. A second switch is operated for designating a desired type of a room situation.

Abstract: In an apparatus for amplifying a sound while suppressing a howling noise, a microphone collects a sound and converts the collected sound into a corresponding input signal. An amplifier amplifies the input signal to generate the sound through a loudspeaker. A plurality of equalizers are interposed between the microphone and the amplifier, each equalizer having a variable attenuation frequency for attenuatively filtering the input signal around the attenuation frequency. Detection is conducted for detecting a plurality of noise spectrum peaks of the howling noise contained in the collected sound. Then, an adjustment is conducted adjusting respective variable attenuation frequencies of the plurality of the equalizers correspondingly to the plurality of the detected noise spectrum peaks to thereby remove the howling noise from the generated sound.

Abstract: A howling prevention apparatus prevents a howling noise which is generated in a sound amplification system using a microphone and a loudspeaker. The howling prevention apparatus utilizes a plural number of first to n-th equalizers, which have a variable frequency response and which modulate an output of the microphone. A detector detects a frequency point at which a loop gain of the system reaches a peak while supplying a standard noise signal to the loudspeaker to produce a test sound and measuring the sound collected by the microphone through the series of the equalizers. A frequency response of the first equalizer is adjusted to suppress a noise peak at and around a frequency point detected by the detector. Then, a frequency response of the second equalizer is also adjusted to suppress a noise peak at and around another frequency point detected by the detector. Lastly, a frequency response of the n-th equalizer is adjusted by subsequently repeating the above setting procedure.

Abstract: A car audio apparatus mounted on an automobile and having a function for preventing theft, the car audio apparatus includes a main body portion fixed to the automobile and a front panel detachably mounted to the main body portion of the audio apparatus. The main body portion has a CPU and a first memory for storing a first secret code and the front panel has a second memory for storing a second secret code. The CPU is capable of respectively reading out the first and second secret codes from the first and second memories and comparing the first secret code with the second secret code so that when both secret codes agree, the CPU enables operation of the car audio apparatus and when both of the secret codes do not agree, the CPU inhibits the operation of the car audio apparatus.