Patent application number | Description | Published |
20080211515 | Method and Apparatus for Measuring Scattering Coefficient of Device Under Test - A measuring method and measuring apparatus for vector-measuring a scattering coefficient of a device under test substantially using a scalar measuring instrument while enabling a reduction in the size of the measuring instrument and the cost. The measurement system includes a signal source that applies a signal to a device under test, a scalar measuring instrument that measures a reflected wave reflected from the device under test or a transmitted wave transmitted through the device under test as a scalar value, and a superimposing signal system that superimposes three different vector signals whose relation values are specified in advance on the reflected wave or the transmitted wave of the device under test. The three vector signals are superimposed on the reflected wave or the transmitted wave of the device under test, and the superimposed signals are each measured as a scalar value by the electric-power measuring instrument. The three measured scalar values are converted into a single vector value using the specified relation values of the three vector signals, thereby obtaining a transmission coefficient of the device under test. | 09-04-2008 |
20090010779 | Piezoelectric Micropump - A piezoelectric micropump in which a pump chamber is isolated by a diaphragm. A piezoelectric element is disposed on a back surface of the diaphragm, and the diaphragm is deformed by bending deformation of the piezoelectric element to change the volume of the pump chamber and transport fluid in the pump chamber. A support member for supporting a back surface of the piezoelectric element is provided so that the support member inhibits bending of a peripheral portion of the diaphragm in a reverse direction. The support member thus prevents the piezoelectric element from being floated. Accordingly, the displacement of the piezoelectric element can be reliably transmitted as the change in volume of the pump chamber, thereby enhancing the fluid transportation performance. | 01-08-2009 |
20090010780 | Micropump - A micropump having a diaphragm portion, a valve portion of an intake-side check valve, and a valve portion of a discharge-side check valve formed in a single elastic-member sheet. A piezoelectric actuator is attached onto a back surface of the diaphragm portion. The elastic-member sheet is sandwiched between a first case member and a second case member, the elastic-member sheet providing sealing between both case members. A vibration chamber is defined between the elastic-member sheet and the first case member, the vibration chamber housing the piezoelectric actuator. A pump chamber is defined between the elastic-member sheet and the second case member. | 01-08-2009 |
20090142209 | Piezoelectric Pump - A piezoelectric pump capable of generating a large displacement at a central portion of a piezoelectric element even when a driving voltage is relatively low and preventing short-circuits caused by migration. The piezoelectric pump includes a pump body with a pump chamber, and a piezoelectric element that closes the pump chamber. The central area and the peripheral area of the piezoelectric element are bent in opposite directions by applying voltages to the piezoelectric element so that the volume of the pump chamber is changed. The piezoelectric element is a laminate including a plurality of piezoelectric layers with electrodes interposed therebetween. The central area and the peripheral area of each piezoelectric layer are polarized opposite to each other in the thickness direction, and the electrodes are formed such that voltages in the same direction in the thickness direction are applied to the central area and the peripheral area of each piezoelectric layer. Since voltages at the same potential are applied to the electrodes formed in the same planes of the piezoelectric layers, short-circuits caused by migration can be prevented. | 06-04-2009 |
20090148318 | Piezoelectric Pump - A piezoelectric pump having a first opening in a center portion of a pump body, and a second opening apart from the center. An outer peripheral portion of a metal diaphragm is fixed to the pump body, and a piezoelectric element having a size that covers the first opening and does not cover the second opening is bonded to a back center portion of the diaphragm. By applying a voltage near the resonance frequency to the piezoelectric element, a portion of the diaphragm opposing the first opening and a portion of the diaphragm opposing the second opening are bent in opposite directions so that fluid is drawn in from one of the first opening and the second opening and is discharged from the other opening. Such a piezoelectric pump can increase the discharging pressure, and can reliably discharge the fluid even under a condition where the pressure on the discharging side is high. | 06-11-2009 |
20090232682 | PIEZOELECTRIC MICRO-BLOWER - A piezoelectric micro-blower capable of efficiently conveying compressive fluid without use of a check valve and ensuring a sufficient flow rate. The micro-blower has a blower body with a first wall and a second wall. Openings are formed in the respective walls and face a center of a diaphragm. An inflow path allowing the openings to communicate with the outside is formed between the walls. By applying a voltage to a piezoelectric element to cause the diaphragm to vibrate, a part of the first wall close to the first opening vibrates. Thus, gas can be drawn from the inflow path and discharged from the opening in the second wall. | 09-17-2009 |
20090232683 | PIEZOELECTRIC MICRO-BLOWER - A piezoelectric micro-blower capable of efficiently conveying compressive fluid without use of a check valve and ensuring a sufficient flow rate. The micro-blower has a blower body with a first wall and a second wall. Openings are formed in the respective walls and face a center of a diaphragm. An inflow path allowing the openings to communicate with the outside is formed between the walls. By applying a voltage to a piezoelectric element to cause the diaphragm to vibrate, a part of the first wall close to the first opening vibrates. Thus, gas can be drawn from the inflow path and discharged from the opening in the second wall. | 09-17-2009 |
20090232684 | PIEZOELECTRIC MICRO-BLOWER - A blower body is provided with a first wall and a second wall, and openings are provided in the walls at positions facing the approximate center of a diaphragm. An inflow passage that allows the openings to communicate with the outside is arranged between the two walls. When the diaphragm is vibrated in response to a voltage applied to a piezoelectric element, the first wall vibrates near the opening and sucks in air from the inflow passage so that the air can be ejected from the opening. A plurality of branch passages which provide sound absorption are connected to an intermediate section of the inflow passage so as to prevent noise generated near the opening from leaking from an inlet. | 09-17-2009 |
20100017669 | METHOD FOR CORRECTING HIGH-FREQUENCY CHARACTERISTIC ERROR OF ELECTRONIC COMPONENT - An electronic-component high-frequency characteristic error correcting method for allowing a calibration work to be performed on a two-terminal impedance component using the same correction-target measuring system as that used in actual measurement. At least three correction data acquisition samples having different high-frequency characteristics are measured by a reference measuring system and an actual measuring system. An equation for associating the value measured by the actual measuring system with the value measured by the reference measuring system using an error correction coefficient of a transmission line is determined. A given electronic component is measured by the actual measuring system. An estimated high-frequency characteristic value of the electronic component obtained when the electronic component is measured by the reference measuring system is calculated using the determined equation. | 01-21-2010 |
20100196177 | VIBRATING DEVICE AND PIEZOELECTRIC PUMP - A piezoelectric pump includes a piezoelectric element, an intermediate plate, and a vibrating plate. The piezoelectric element has a substantially flat plate shape. The intermediate plate is bonded to a principal surface of the piezoelectric element and applies a residual stress in a compressive direction to the piezoelectric element. The vibrating plate is bonded to the intermediate plate such that the vibrating plate faces a principal surface of the piezoelectric element and receives a residual stress in a compressive direction from the intermediate plate. In addition, the vibrating plate defines a portion of a wall surface of a pump chamber having an open hole. A fluid passage is provided in the piezoelectric pump. The fluid passage communicates with the outside of the chamber at one end thereof, and communicates with the pump chamber through the open hole at the other end. | 08-05-2010 |
20110005733 | PIEZOELECTRIC FAN AND COOLING DEVICE USING PIEZOELECTRIC FAN - A piezoelectric fan includes a piezoelectric vibrator that vibrates in a bending mode when a voltage is applied thereto and a plurality of parallel or substantially parallel blades connected to or integrated with the piezoelectric vibrator. The blades are arranged between heat-radiating fins of a heat sink such that the blades bend parallel or substantially parallel to side surfaces of the heat-radiating fins. A joint that connects the blades to each other is disposed at free ends in a longitudinal direction of the blades. When the blades are excited by the piezoelectric vibrator and warm air between the heat-radiating fins is blown, the joint prevents the blades from twisting. | 01-13-2011 |
20110014069 | PIEZOELECTRIC FAN DEVICE AND AIR-COOLING APPARATUS USING THE PIEZOELECTRIC FAN DEVICE - A piezoelectric fan device includes four piezoelectric fans that are arranged side-by-side in their width direction, and ends of the piezoelectric fans opposite to other ends in which the blades extend are coupled side-by-side and supported by a support. The piezoelectric fans include piezoelectric vibrators arranged to flexurally vibrate when a voltage is applied thereto and blades coupled to the piezoelectric vibrators such that the blades can be excited by the piezoelectric vibrators. Two central piezoelectric fans are driven in the same phase and the other two piezoelectric fans are driven in the opposite phase by a voltage applying device. Accordingly, not only vibrations of the centroid acting on the support but also moments about three axes are cancelled out. | 01-20-2011 |
20110064594 | COOLING DEVICE - A piezoelectric fan includes a blade that is joined to a piezoelectric oscillator that bends in response to an application of a voltage, and the blade of the piezoelectric fan is arranged to swing in a space between neighboring heat dissipating fins of a heat sink. The formation of a hole in the blade increases the amplitude of the blade and also improves the sweep effect of sweeping high-temperature air in the vicinity of the wall of the heat dissipating fin, and thus, improves the cooling capability of the piezoelectric fan. | 03-17-2011 |
20110068657 | PIEZOELECTRIC ACTUATOR DRIVER CIRCUIT - In a piezoelectric-actuator driving circuit for driving a piezoelectric actuator, an amplifier circuit amplifies a signal output from a feedback circuit and supplies the amplified signal to a non-inverting amplifier circuit and an inverting amplifier circuit. The non-inverting amplifier circuit amplifies the output voltage of the amplifier circuit with a predetermined gain and applies the amplified voltage to a first terminal of the piezoelectric actuator. The inverting amplifier circuit inverts and amplifies the output voltage of the amplifier circuit with the same gain as that of the non-inverting amplifier circuit and then applies the amplified voltage to a second terminal of the piezoelectric actuator through resistors. The feedback circuit amplifies a difference between voltages at respective ends of the resistor and supplies the amplified difference to the amplifier circuit. | 03-24-2011 |
20110068658 | PIEZOELECTRIC ACTUATOR DRIVER CIRCUIT - In a piezoelectric actuator driver circuit, a resistor provided to detect current is inserted in a current path for a piezoelectric actuator. A signal of a decreased voltage of the resistor is subjected to positive feedback to an amplifier circuit via a band-pass filter. An output signal of the amplifier circuit is subjected to negative feedback to the amplifier circuit via a band-elimination filter. The band-pass filter allows a signal of a fundamental resonant frequency of a piezoelectric device, which includes the piezoelectric actuator, to pass therethrough, and the band-elimination filter blocks the signal of the fundamental resonant frequency. Thus, a loop gain at a higher-order resonant frequency with respect to the fundamental resonant frequency becomes very low and a higher-order resonant mode can be effectively suppressed. | 03-24-2011 |
20120134858 | COOLING DEVICE - A piezoelectric fan includes a blade that is joined to a piezoelectric oscillator that bends in response to an application of a voltage, and the blade of the piezoelectric fan is arranged to swing in a space between neighboring heat dissipating fins of a heat sink. The formation of a hole in the blade increases the amplitude of the blade and also improves the sweep effect of sweeping high-temperature air in the vicinity of the wall of the heat dissipating fin, and thus, improves the cooling capability of the piezoelectric fan. | 05-31-2012 |
20120293041 | PIEZOELECTRIC ACTUATOR DRIVER CIRCUIT - In a piezoelectric actuator driver circuit, a resistor provided to detect current is inserted in a current path for a piezoelectric actuator. A signal of a decreased voltage of the resistor is subjected to positive feedback to an amplifier circuit via a band-pass filter. An output signal of the amplifier circuit is subjected to negative feedback to the amplifier circuit via a band-elimination filter. The band-pass filter allows a signal of a fundamental resonant frequency of a piezoelectric device, which includes the piezoelectric actuator, to pass therethrough, and the band-elimination filter blocks the signal of the fundamental resonant frequency. Thus, a loop gain at a higher-order resonant frequency with respect to the fundamental resonant frequency becomes very low and a higher-order resonant mode can be effectively suppressed. | 11-22-2012 |