Showing papers on "Bimorph published in 1982"

Piezoelectric heat exchanger

Abstract: Apparatus is disclosed for providing increased heat transfer efficiency in a heat exchanger by separating contiguous fluid conductive channels by means of a flexible partition of a bimorph construction consisting of two adjacent layers of piezoelectric material arranged so that, when an electrical signal is applied, one layer expands while the other contracts causing the composite sheet to flex and push a sub-laminar layer of the fluid located adjacent to the sheet away into the turbulent stream while drawing other fluid into contact with the partition. The preferred embodiment of the invention additionally includes a grid or mesh member between the two layers for strengthening the partition so that it can withstand a relatively large pressure gradient thereacross.

Piezoelectric bimorph element

Abstract: PURPOSE:To obtain the bimorph element, performance characteristics thereof for a prolonged term under high tension per a piezoelectric ceramic element unit are excellent, by using piezoelectric ceramics, coercive electric fields thereof differ mutually, as the elements when the piezoelectric bimorph element is manufactured by pasting the two piezoelectric ceramic elements together. CONSTITUTION:A piezoelectric bimorph element is constituted by pasting two piezoelectric elements 1 and 2 together. In the constitution, a Pb(TiZr)O3 group element with breakdown electric field 250V/mm. and a comparatively high piezoelectric modulus m/V in used as the element 1, and an element, which belongs to the same Pb(TiZr)O3 group but the coercive electric field thereof is 1,000V/mm., is employed as the element 2. These elements 1 and 2 are pasted together by using denatured acrylate adhesives while holdg a metallic intermediate electrode plate 3. The elements are immersed in silicone oil elevated to 90-100 deg.C, 4kV/mm. DC voltage is applied in the thickness direction, and polarization treatment is executed so that the directions of polarization are made equal. According to such constitution, negative potential is applied to the electrode plate 3 and positive potential to the elements 1 and 2.

Piezoelectric type electroacoustic converter

Abstract: PURPOSE:To improve the durability, by fitting an electrode smaller than a diameter of a diaphragm plate on the surface of the diaphragm plate made of a high polymer member, and coating the electrode with an organic protective layer having a diameter smaller than the diameter of the diaphragm plate and larger than the electrode diameter. CONSTITUTION:Flexible piezo-electric substance sheets 111 and 112 using a high polymer material polarized toward the specified broadwise direction are formed with polyfluoride vinylidene, its copolymer or composite material taking them as a matrix and filling inorganic ferrodielectric powder. External electrodes 121 and 122 and internal electrodes 131 and 132 are provided and they are laminated toward the broadwise direction with an organic adhesives 14. The external electrodes 121 and 122 are formed with Al film. Epoxy resin is coaed on the external electrodes 121 and 122 to form organic protective layers 151 and 152. Cr plating layers 1611, 1612, 1621 and 1622 are provided on eletrode terminals 1211, 1212, 1221 and 1222 covered with the layers 151 and 152. A bimorph diaphragm plate thus obtained is clamped with a clamp tool to constitute a piezo-electric electroacoustic converter.

Valve using bimorph piezoelectric element

Abstract: PURPOSE:To have a valve with less noises and heat emission by impressing a voltage on a lamination of bimorph piezoelectric element made from high molecular piezoelectric film of fluororubber etc so that the lamination is deflected, and by moving the valve element by the use of the deflection CONSTITUTION:In housing 7 is installed a lamination of a bimorph piezoelectric element 9, fixed at its periphery with a number of peripheral spacers 10 and push plates 11 A coupling shaft 12 is installed at the center of this lamination, one end being fixed to a diaphragm 6 The bimorph piezoelectric element 9 is formed by laminating two disc-shaped high molecular piezoelectric films made of high polymers such as fluororubber, vinylidene fluoride polymer A voltage is impressed on each bimorph piezoelectric element 9 to carry out opening and closing of valve

Control of auto-tracking in tracking-error correcting system of video recording/reproducing apparatus

Abstract: A tracking-error correcting system in a rotary head magnetic recording and reproducing apparatus in which reproducing magnetic heads are mounted on a respective bimorph leaf having piezoelectric elements so as to be movable in the direction of the axis of rotation. The piezoelectric elements are controlled by a control voltage which is produced by adding a signal from an auto-tracking circuit and a signal from a triangular wave generating circuit. In a reproducing mode at a tape speed which is different from a tape speed in recording mode, this system activates the auto-tracking circuit when the control voltage level is within a limited range which is detected by a control voltage detector. Also, this system stops the auto-tracking circuit during a transition period when the reproduction mode changes.

Bimorph piezoelectric element

Abstract: PURPOSE:To obtain high elastic strength and universality in a bimorph piezoelectric element by aligning the polarizing direction of a plurality of piezoelectric plates in the same direction, andbonding thereto a single piezoelectric plate formed by laminating and bonding as one plate. CONSTITUTION:Two piezoelectric plates 1a which have a thickness of t0/2 are aligned as a piezoelectric plate corresponding to a single piezoelectric plate 1 having a thickness of t0 so that the polarizing directions are coincident, laminated and bonded with an adhesive having large elastic deformation state. The single piezoelectric plate 1' which is thus bonded is used and bonded to each of both sides of a metal plate 3, and electrodes 2 are attached to both side surfaces of a piezoelectric element 6'. In this manner, a bimorph piezoelectric element which has high elastic strength and excellent universality can be obtained.

Automatic scan tracking with ringing control

Abstract: A dithered automatic scan tracking system for a videotape playback machine includes a bimorph which with its associated load has a mechanical resonance. In special-effects operating modes, the jump or reset signal which drives the bimorph at the end of its scan to position the playback transducer for the next track excites the mechanical resonance, which causes incorrect demodulation of the detected FM envelope and therefore causes generation of an incorrect AST loop error signal until the excited resonance dies away. A gated phase-lock loop is coupled to the bimorph position sensor and produces clock signals for control of the demodulation of the detected FM envelope. The gate decouples the position sensor from the phase-lock loop during recurrent intervals including those intervals during which the mechanical resonance is excited. This allows generation of a correct error signal immediately after the jump and reduces mistracking.

Ultrasonic transmitting and receiving device

Abstract: An ultrasonic transmitting and receiving device comprises a bimorph vibrator including two piezoelectric elements each connected electrically to the corresponding one of a plurality of terminals for receiving and delivering electric signals and a metallic member made of a thin metal plate and including a flat plate portion and a cylindrical portion extending from the circumferential periphery of the flat plate portion. The flat plate portion is placed between the piezoelectric elements and the cylindrical portion increases in outer diameter as it becomes distant from the flat plate portion.

Piezoelectric Plastic Microphones

Abstract: Current types of microphones are described and compared with designs based on a bimorph diaphragm made from piezoelectric poly(vinylidene fluoride) film. A pressure operated microphone for telephone handsets has been fully developed. Polymer film diaphragms lend themselves to highly symmetrical designs so that both first and second order pressure gradient noise cancelling units have been based on them and compare well with the available alternatives.

Method of production of piezo-electric polymer transducers

Abstract: Procede de fabrication de transducteurs piezoelectriques a polymeres, bimorphes, comportant une electrode centrale (8) en un materiau polymere conducteur qui s'unit intimement aux lames (7) du transducteurs. A method of manufacturing a piezoelectric transducer polymers, bimorph, comprising a central electrode (8) of a conductive polymeric material which is intimately united to the blades (7) of the transducers. Application aux transducteurs bimorphes pouvant etre utilises en emetteurs et/ou capteurs electroacoustiques. Application to bimorph transducers that can be used in transmitters and / or electroacoustic sensors.

Optical deflecting device

Abstract: PURPOSE:To obtain a small-sized optical deflecting device which has a fast response speed, by utilizing piezoelectric effect to vary the curvature of a light- transmissive piezoelectric element surface by a voltage, and changing a route of incident light. CONSTITUTION:The optical deflecting device consists of discoid light-transmissive piezoelectric elements 1 and 2, bimorph structure and transparent electrodes 3 and 4. When a voltage is applied between the electrodes 3 and 4, one piezoelectric element extends and the other contracts. Those elements 1 and 2 are coupled mechanically by adhesion, so the disk curves to vary its surface curvature. Consequently, a routh of the incident light 6 are changed. The piezoelectric elements 1 and 2 use PLZT; the electrode 3 is applied with a high plus voltage in oil to polarize the element 1 and the element 2 is also treated similarly. The transparent electrodes 3 and 4 use ITO. Consequently, the smallsized optical deflecting device with a fast response speed is obtained.

Photoelectric drive circuit for a piezoelectric bimorph element

Abstract: A photoelectric circuit arrangement includes one direct current voltage source and first and second photoconductive networks, each comprising at least one resistance and one photoconductive cell. An output voltage generated between two output terminals of the first and second networks is directly applied to a bimorph element used to close or open a blind. The strong light causes the networks to be in low resistive state so as to produce the output voltage of one polarity to bend the bimorph in one direction and thereby to tend to close the blind, while the weak light causes the networks to be in high resistive state so as to produce the output voltage of the other polarity to bend the bimorph in the opposite direction and thereby to tend to open the blind. The first and second photoconductive networks can be integrated in one body.

Moving mechanism for rotary magnetic head

Abstract: PURPOSE:To displace a rotary magnetic head greatly without increasing the slanting angle of the rotary magnetic head too much, by fitting the rotary magnetic head to the free terminal part of a platelike movable element with an extending material interposed CONSTITUTION:A rotary magnetic head 1 is not fitted directly to a bimorph plate made of a piezoelectric material, but fitted to the free terminal side of a bimorph plate 2 whose one terminal is fixed to a fitting tool 9 by being connected through an extending material 11, thus fitting it at the top of the extending material 11 The extending material 11 may use any material, but it is favorably less in flection to external force applied to the rotary magnetic head 1 and small in density

Scanning on-demand ink jet printer

Abstract: PURPOSE:To provide a titled printer which enables deflecting of ink drop, by constituting a device such that an end part of a head incorporating a nozzle can be transformed and is caused to deflect by means of a bimorph vibrator. CONSTITUTION:A part, incorporating a nozzle 4, of a sustrate 200 is formed in a very thin thickness, and through using of a material such as stainless materials, having a high elasticity, as a substrate material, said part is caused to transform in the direction of the thickness of the substrate. A bimorph vibrator 9 is adhered firmly to the outside of the substrate along the nozzle 4, and the direction of the nozzle is deflected based on a drive signal to change a jet direction of ink drop through the nozzle.

Piezo-electric type speaker

Abstract: PURPOSE:To simplify the structure and reduce the size and weight by fixing a diaphragm at the center of a piezo-electric bimorph element in which plural slits are provided radially from the center and fixing the periphery of the element and diaphragm to respective frames and thereby using the element as a piezo-electric type speaker. CONSTITUTION:A diaphragm 4 provided with corrugation on the periphery is fixed in a hole 2 at the center of a piezo-electric bimorph element 1 provided with plural slits 3 radially from the center. The periphery of the diaphragm 4 and bimorph element 1 is fixed to platy frames 5 provided with a hole in the center and ring-like steps 5a, 5b are made on the hole side at the center of both sides of the frame 5. Terminals 7, 8 are fixed to the frames 5 and connected to a specified electrode of the bimorph element 1. The bimorph is divided into plural bimorph pieces and electric impedance of the bimorph element 1 is made low looked from the terminals 7, 8. Thus, efficiency of the piezo-electric type speaker is improved and the structure is made simple to allow mass production.

Piezoelectric type acceleration detecting pickup

Abstract: PURPOSE:To detect the acceleration in a plurality of directions by one device by arranging a plurality of plate shaped piezoelectric bimorph elements supported in a cantilever form or at both ends on the main body of a case so that their relative angles are different from each other. CONSTITUTION:The plate shaped piezoelectric bimorph elements 2 and 2 are supported on the internal surface of a casing 15 of the pickup 1, with one end of each element buried and fixed as a cantilever mode. The angle formed by the elements is 90 deg. in a horizontal plane. The rotary slant angle thereof in the longitudinal direction is zero, and they are vertically arranged. Lead wires 21 and 21, which transmit the induced output voltages to an external detector, are conneted to the bimorph elements 2 and 2. When the acceleration is applied to the bimorph elements 2 and 2, the voltage is induced in response to the magnitude thereof, and transmitted by the lead wires. When a plurality of the elements are arranged so that the relative angles are different from each other, the acceleration in a plurality of directions can be detected by one pickup.

Axial-Mode Piezoelectrically-Driven Beam Deflectors

Abstract: A random -access beam scanner using axial -mode expansion of a stack of piezoelectric disks has beenfabricated and tested. The measured performance was comparable to that of scanners using galvanometer orpiezoelectric bimorph drivers. Computations predict that improved coupling of the stress developed by axial -mode devices can extend the performance of these devices to levels well beyond those now available.IntroductionStacks of piezoelectric disks known as Piezomotors® (PZMs) have been applied to a large variety of applica-tions ranging from diesel injection pumps to impact printer hammers.1 Although PZMs develop small strains (upto 0.15 percent), they can apply very large forces because of their high axial modulus. They are able todisplace with infinite resolution and to reproduce their performance over many millions of cycles.In response to a requirement for a laser beam scanner with fast response, Physics International Companydeveloped a beam deflector using axial -mode displacement of a split Piezomotor® to oscillate a mirror of

Printing head for wire dot printer

Abstract: PURPOSE:To simplify the device and increase its operating speed, in a printing head for a wire dot printer of electrostriction-type wire driving system, by employing such a design as to fix the wire onto the top of a bimorph type electrostriction oscillator formed into an isosceles triangular shape. CONSTITUTION:A bimorph type electrostriction oscillator 1, which is composed of a metallic sheet 2 and two piezoelectric conversion elements 3 and 4 joined to both sides of the metallic sheet 2, is formed into an almost isosceles triangular shape, and a wire 6 is fixed onto the top. When a voltage is applied onto the side of a terminal 9, the piezoelectric conversion element 4 on the rear side displaces in the direction of contraction, and the top of the metallic sheet 2 displaces and moves from a stationary position N to a resting position 1. When the switching is made from a to b by a switching circuit, the piezoelectric conversion element 3 on the front side displaces in the direction of contraction, the top of the metallic sheet 2 displaces and moves from the resting position 1 to a printing position 2, and printing motion is performed by the wire 6.

Head supporting device of recorder and reproducer

Abstract: PURPOSE:To execute the tracking of a head in case of a high double speed reverse reproducing operation or a high double speed reproducing operation, by constituting so that two electromechanical converting elements are supported in a cantilever mode, and also the head is installed to a free end of one converting element. CONSTITUTION:A head supporting device is provided with monomorph plates 13, 14 placed on both surface sides of one end part of a bimorph plate 1, and 2 pairs of conductive spacers 16-19 placed on both end parts in the lengthwise direction of these monomoph plates 13, 14 and also provided between the bimorph plate 1 and the monomorph plates 13, 14. Also, in a state that one end part of the bimorph plate 1 has been placed between the monomorph plates 13, 14 through the spacers 16-19, the upper surface of one end part of the monomorph plate 13, and the lower surface of one end part of the monomorph plate 14 are made to adhere and fixed to a base body part 15 of a rotary drum 9a, and the bimorph plate 1 is supported by the base body part 15 so that its one end part is suported in a cantilever mode.

Manufacture for bimorph element

Abstract: PURPOSE:To increase the coefficient of electromechanical coupling, by forming electrodes through the vapor deposition of conductive substance to both sides of a piezoelectric element. CONSTITUTION:Electrodes 2, 3, 2', 3' are provided at both sides of piezoelectric elements 1, 1'. A conductive member 4 serving also as a reinforced plate is bonded in both the sides with the sides of the elctrodes 3, 3' of the elments 1, 1'. The free surface of the piezoelectric elements can be made suited without any excess or shortage by forming the electrodes 2, 3, 2', 3' through the vapor deposition of a metal, and the elctrodes can be formed without any glass flit. Thus, higher static capacitance can be obtained and the coefficient of electromagnetic coupling can be increased.

Driving device for angular displacement

Abstract: PURPOSE:To provide an angular displacement driving device with a simple structure, which is excellent in productivity and maintenance by applying a voltage to a bimorph piezoelectric element which is wound, and by giving an anglular displcement to an object to be driven. CONSTITUTION:A bimorph piezoelectric element 1 is formed into like a belt shape and wound spirally. One end part 2 outward in the radial direction of said element 1 is fixed in a case 7 of a voltmeter. The other end part 3 inward in the radial direction of said element 1 is fixed on a rotary axis 4. The rotary axis 4 is supported with a bearing in the case angular displacable manner and on a number plate 10, an index pointer 9 is fixed.

Contact pressure controller for magnetic head of head drum device

Abstract: PURPOSE:To keep a constant level of the contact pressure of a magnetic tape, by not only fixing a magnetic head chip to a cantilever but providing a detecting means for the magnetic head chip to a magnetic recording tape and then actuating a position control means of the magnetic head chip. CONSTITUTION:The electrodes 6 of the same size plus the electrodes 6' of a smaller size than the electrode 6 are attached to both surfaces and their junction surface of a piezoelectric element plate 3 of a bimorph beam 3. Then the voltage is applied to the electrode 6, and thus the pressure is applied to the tip of a chip 1 to cause a distortion to the beam 3. As a result, the voltage is generated to the piezoelectric element. The voltage of the electrode 6' is compared with the reference voltage. Then the result of this comparison is amplified, and the voltage is applied to the electrode 6. Thus the tip of the chip 1 shifts to produce a constant level of the contact force.

Driving device for photometric mirror of single lens reflex camera

Abstract: PURPOSE:To provide a titled device of a low cost by providing a member of bimorph construction including a piezoelectric element to a sub-mirror which turns according to the turning of a main movable mirror. CONSTITUTION:Under photometry or during closing of a shutter, no voltage is applied from an electric power source 14 to the bimorph plate of a sub-mirror 11, and the light reflected by the specular surface of the mirror 11 is made indicent to a photodetector 12, by which photometry is accomplished. While a film 15 is under exposure through the opened shutter where a main mirror 10 is up, a switch 13 closes and the voltage from an electric power source 14 is applied to the bimorph plate of the mirror 11, by which the mirror 11 is deformed to avert to the outside of the photographing luminous flux, thereby shielding the semitransparent mirror part of the mirror 10. It is possible to make the specular surface worked on the bimorph mirror uniform or to divide the same to plural areas according to need.

Bimorph driving type analog electronic timepiece

Abstract: PURPOSE:To simplify mechanism and to reduce thickness by transferring a signal from a time reference signal outputting means directly to hands by utilizing the large displacement of a bimorph element made of a high polymer film treated to have piezoelectric characteristics by polarizing operation CONSTITUTION:Films 41 and 42 are formed by elongating polarized high polymer materials, and then polarizing them by a heat treatment while applying a high DC voltage in the width direction Those are stucked together in the opposite directions with thin-film electrodes 43 and 44 between, thus constituting one multilayered bimorph element 4 Lead terminals 45 and 46 are connected to alternate top and reverse surface electrodes 44 and interlayer electrodes 43 and 44 Then, output signals from prescribed stages of a frequency dividing circuit are applied to the terminals 45 and 46 Namely, a bimorph element 14 for driving a second ratchet wheel inputs a signal of 1Hz which corresponds to the number of teeth of the second ratchet wheel 11 or having a frequency which is a multiple of 1Hz, and bimorph elements 24 and 34 for driving a minute ratchet wheel 21 and an hour ratchet wheel 31 input pulse signals for rotating those wheels 21 and 31 once in an hour and twelve hours respectively

Plane-plate speaker

Abstract: PURPOSE:To make a high-fidelity reproducing possible, by driving a plane-plate vibration diaphragm by plural bimorph piezoelectric transducers with one end fixed. CONSTITUTION:A piezoelectric transducer 11 is put on a fitting part 3 projected in the center of the inside bottom part of a frame 2, and a holding plate 6 is applied from above, and screws 7 are inserted to fitting holes provided in four corners of the holding plate 6 to fix them, and thus, the piezoelectric tranducer 11 is held by the fitting part 3 and the holding plate 6. Insulating sleeves 8 are inserted to body parts of screws 7. Next, an adhesive is filled up in a gap 14 between the piezoelectric transducer 11 and the holding plate 6 to prevent an undesired vibration in the root part of mounting of this transducer.

Bimorph type electrostrictive vibrator

Abstract: PURPOSE:To increase a mechanical variance and a mechanical energy considerably, by making the thickness of piezoelectric elements different in the forward side of the reverse side of polarization CONSTITUTION:When the thickness of a piezoelectric element 11 is h1, the thickness of other piezoelectric element 12 is h2h1=nh2(0

Bimorph piezoelectric element

Abstract: PURPOSE:To minimize the reduction in static capacitance, by providing a punching part at a metallic electrode plate sticked with a piezoelectric plate, without reducing the coupling rate. CONSTITUTION:In a bimorph piezoelectric element which is used for a piezoelectric acoustic converter consisting of sticked and laminated piezoelectric plates by taking a metallic electrode plate (m) as the intermediate layer, punching parts (s) is located to the metallic electrode plate (m). The area ratio range of the punching parts (s) is 30-70%. As the shape of the punching parts (s), the shape not preventing the radial movement is adopted, such a square, radial and non defined shapes. Thus, the reduction in static capacitance can be minimized but the coupling rate can not be lowered.

Piezoelectric deflection element

Abstract: PURPOSE:To prevent the generation of cracks and discharge by applying insulating substance to only the stepped level section of two piezoelectric ceramic plates in a bimorph type piezoelectric element used by adhering two piezoelectric ceramic plates having different inside diameter and by connecting them in parallel. CONSTITUTION:Insulating substance 9 such as silicon rubber adhesives or epoxy resin is applied and fixed on the stepped level part at the inside diameter side, namely electrode 6, of two piezoelectric porcelain plates 3, 4 having different inside diameter so that the electrode 6 and solder at the mounting section of a lead wire 7 may be covered. In this way, generation of discharge and cracks in humid status can be prevented without providing coating film thickner than the insulating substance 9.