Showing papers on "Bimorph published in 1985"

PVF2 velocity hydrophones

Abstract: In underwater acoustical low‐frequency applications a hydrophone with intrinsic directivity is often needed. Poled polyvinylidene fluoride (PVF2) bimorphs are suitable for design of velocity hydrophones. Because of its softness and mechanical flexibility, a PVF2 bimorph associated with an inertial structure follows water particle movement, and so the output current from the hydrophone is proportional to the particle velocity of the incident wave. Moreover, the PVF2 bimorphs manufactured in our laboratories (whose thickness may be greater than 1 mm), make possible a compromise between the opposite requirements that a high sensitivity demands a thick polymer and for a high mechanical flexibility of the membrane (to obtain the lowest possible resonance frequency) a thin bimorph is needed. The study of a low‐frequency particle velocity calibration system made possible the achievement of small lightweight PVF2 velocity hydrophones showing an intrinsic directivity below 100 Hz. The same hydrophone can be connec...

Wobbling-swing driven image sensor

Abstract: A solid-state image sensing device (10), such as an interline-transfer type charge-coupled device (IT-CCD), produces signal carriers in response to incident light and generates an image pickup signal. One frame of the image signal is formed of two fields. The CCD chip (10) is coupled to fixed bimorph piezoelectric vibrators (12, 14) by which it is given a wobbling-swing drive during image pickup. This wobbling-swing drive is controlled by a vibration controller (28). This vibration controller (28) controls the vibration mode of the bimorph piezoelectric elements (12,14) to apply a first vibration (swing vibration) to the CCD (10) such that each pixel cell is displaced to a different sampling position in the plurality of field periods included in one frame period for image pickup, and applying a second vibration, i.e., a swing vibration with wobbling superposed, to the CCD (10) such that each pixel cell is wobbled while picking up an image in each sampling position, which is positioned in each field period.

Piezoelectric optical beam deflector

Abstract: A piezoelectric bimorph scanner is disclosed which has a flexural beam attached to the free end of a cantilever mounted piezoelectric bimorph crystal. A mirror is bonded to the flexural beam a predetermined distance from the bimorph crystal. An AC voltage of predetermined frequency is applied to the bimorph crystal causing the flexural beam to oscillate with a node at the center of the mirror. The mirror rotates about the node rather than swinging in an arc, enabling the scanner to deflect a collimated light beam over a larger deflection angle than heretofore possible without additional light beam control apparatus. In an alternate embodiment, a laser diode may be mounted on the flexural beam instead of the mirror, further reducing costs and components.

A piezoelectric fan using pzt ceramics

Abstract: A fan consisting of a piezoelectric bimorph tipped with an additional flexible blade is introduced. Since the flexible blade resonates in a large amplitude but the bimorph vibrates in a very small amplitude, the fan can supply sufficient and constant air flow without any structural destruction for a long time. The fan case has two air outlets which are directed oppositely each other. The fan with such outlets can supply an air flow of 4 m3/hr at an applied voltage of 140 Vp–p. Another type of a piezoelectric fan using multi-layered PZT ceramic elements produced by a thick film printing technique is introduced. This fan is suitable for low voltage operation and it can supply an air flow of 1 m3/hr at an applied voltage of 17Vp–p.

Tracking control devices for video tape recorders

Abstract: A tracking control device for a video tape recorder comprises a bimorph leaf on which a rotary playback head is mounted so as to be deflectable in a direction perpendicular to tracks to be scanned. A triangular wave signal generating circuit comprising cascaded flip-flops generates a substantially triangular wave signal which is supplied to the bimorph leaf to cause the playback head to wobble relative to the tracks. A detecting circuit detects an envelope signal in the signal reproduced by the playback head, and a phase comparing circuit which includes an exclusive-OR circuit compares the phase of this envelope signal with the phase of the triangular wave signal. The output of the phase comparing circuit is fed back to the bimorph leaf to effect tracking correction.

Properties and Applications of Screen Printed Piezoelectric Films

Abstract: Thick piezoelectric films are fabricated by screen printing and firing the pastes prepared with either the calcined or the sintered composition of Pb0.9875[(Zr0.52Ti0.48)0.975Nb0.025]O3. Lithium carbonate and equal amount of Bi2O3 are added as liquid phases to promote densification. The spontaneous polarization, Ps, of the fabricated piezoelectric films ranges from 6 to 10 µC/cm2, the remanent polarization, Pr, is from 3 to 8 µC/cm2, and the coercive force lies between 1.8 to 4KV/mm. Bimorph structure is formed by fabricating the piezoelectric film on a piezoelectric ceramic (PZT) sheet. The film and the PZT sheet are oppositely poled for buzzer application. By fabricating the piezoelectric film on stainless steel sheet directly, a new piezoelectric transducer is formed, with better performance and durability to temperature higher than 100°C.

Bimorph piezoelectric driving device

Abstract: PURPOSE:To make driving operation stable by a method wherein when outside electrodes are fixed on the outside surface of a rectangular bimorph vibrator fixed one end of which as a cantilever and the other end left as a free end, the outside electrodes are not provided on the section reaching a point at a specified distance from the free end but a driving member is provided on the free end. CONSTITUTION:Electrodes 4 and 5 are respectively formed on the surface and backside of the first piezoelectric ceramics 3 to be the first piezoelectric element 6 likewise electrodes 8 and 9 are respectively formed on the surface and backside of the secod piezoelectric ceramics 7 to be the second piezoelectric element 10. Next the electrodes 5 and 9 sides of said elements 6 and 10 are sticked on a metal plate 11. One end of these piezoelectric elements 6, 10 and the metal plate 11 are held by a supporting member 13 like a cantilever and the other end 2b is left as a free end to fix a rotary head 1 of VTR. In such a constitution, the electrodes 5 and 9 are respectively provided on the overall length of the ceramics 3 and 7 but the electrodes 4 and 8 are not provided on the overall length but fixed on the section outside a point at a specified distance of 1/10- 2/3 of the exposed length L from the free end.

Multilayer Piezoelectric Ceramic Bimorph Actuator

Abstract: Electromechanical properties have been studied for piezoelectric ceramic bimorph actuator without adhesive process, in which many internal electrodes were layered. The presently developed actuator with a size of 40 mm×12 mm×0.8 mm, shows 500µm free displacement or 60 gf clamping force by applying voltage V1=40, V2=-10 DCV. Increasing in layer number of internal electrodes of the actuator, leads to decrease the displacements and to increase the generative force. The hysteresis of the actuator was not only reduced to about one third of that of the conventional type, but also both of the creep and shift phenomena were sufficently reduced.

Adaptive cooled mirror for the resonator of an industrial laser

Abstract: The construction of a semipassive adaptive cooled bimorph mirror is described. The results are given of an investigation of its principal characteristics, such as the sensitivity and the response function of the electrodes. The results of tests under the influence of a high-power laser beam are also given.

Operating device of camera using bimorph element

Abstract: PURPOSE:To increase the displacement extent of a bimorph element used in a camera as a control means by applying the AC voltage of a boosting circuit. CONSTITUTION:For example, when the output of a distance detecting circuit is low as to the AC voltage appearing at the output terminal 64 of an ordinary boosting circuit 56, transistors (TR) 84 and 88 are normally off and a negative voltage is applied to the bimorph element 18 equivalent to a capacitor in terms of circuitry through a resistance 80 and a diode 82. When the output of the distance detecting circuit goes up to a high level as a result of focusing, etc., the TRs 84 and 88 turn on to apply a positive voltag through a diode 66, and the bimorph element operates. The boosting circuit is usable as the ordinary flash circuit which includes a main capacitor 68 and a flashbulb 70.

Flow adjusting device

Abstract: PURPOSE:To miniaturize and simplify the constitution of a flow adjusting device and also to improve the performance of machining and control by using a bimorph type piezoelectric element so as to adjust the flow. CONSTITUTION:Since the bimorph type piezoelectric element 11 is formed by overlapping piezoelectric elements expanded and contracted reciprocally in response to a voltage, the element 11 is changed from, e.g., state 11a to 11b in response to a voltage of a power supply 13 controlled by a signal transmitted from a flow control circuit 5. That is, the distance between a gas flowing part of an oriffice 10 and the piezoelectric element 11 is adjusted by a generated voltage of the controlled power supply 13 so as to control the flow of gas. The constitution comprising the oriffice 10 and the bimorph type piezoelectric element 11 is simplified for the flow adjusting part, the performance of machining is improved, the miniaturization is attained, and the displacement is controlled by a voltage applied to the piezoelectric element, then a high flow control performance is attained.

Piezoelectric Ceramic Transducers for Electronic Telephone Sets

Abstract: Three kinds of piezoelectric ceramic transducers–a transmitter, a receiver and a tone ringer sounder–are developed for new electronic telephone sets. These new transducers use a bimorph diaphragm of equal dimensions, consisting of a piezoelectric ceramic plate and a brass plate. They are designed considering both the fundamental resonance frequency of the diaphragm and the individual frequency responses required for each telephone transducer. The diameter of the transducer is about 33 mm and the thickness is about 6 mm. The volume of the new transducers is reduced to about 1/10 and the number of parts to about 1/2 compared with conventional transducers.

Lens focusing device

Abstract: PURPOSE:To execute a driving smoothly and with a high accuracy by using an annular bimorph unit having an electrostrictive characteristic, as a lens operating body. CONSTITUTION:Annular bimorph units 5, 6 are formed by laminating plural sheets of annular bimorph simple substances 8. The bimorph simple substance 8 is formed by combining a pair of two plate annular electrostrictive materials 8a, 8b by placing an electrode 8c between them. With respect to the electrostrictive materials 8a, 8b, when a voltage is impressed to the electrode 8c and the center part is fixed at a prescribed position, the electrostrictive materials 8a, 8b are curved in both the upper and lower ends, and a displacement quantity in its end part is roughly proportional to the impressed voltage. Two sets each of the annular bimorph units 5, 6 which have superposed the bimorph simple substance 8 are placed on both sides of a movable cylinder 2 for holding a focus lens 1. When the impressed voltage is adjusted so that they negate a load each other, the focus lens 1 can be fed out and in smoothly by sliding the movable cylinder 2 forward and backward in the optical axis direction, and its magnitude can be realized by controlling the impressed voltage V to the electrode 8c.

Modulation Type Pyroelectric Infrared Sensor Using LiTaO3Single Crystal

Abstract: A pyroelectric infrared sensor with a solid state chopper was developed. Ordinarily, the incident rays of pyroelectric IR sensors must be periodically interrupted by means of a chopper, which consists of a motor and a revolving plate, in order to generate a continuous output voltage for temperature measurement. We have developed a new pyroelectric infrared sensor structure by replacing the chopper with a solid state setup consisting of a bimorph vibrator and a grate-type slit plate.

Piezoelectric displacement element

Abstract: PURPOSE:To prevent any crack or breakdown due to stress concentration from happening by a method wherein an electrode near ends subject to the maximum displacement is eliminated in a piezoelectric displacement element composed of two sheets of ring type piezoelectric element supporting the central part as cantilevers CONSTITUTION:Two sheets of piezoelectric elements 6, 7 are bonded together subject to common direction of polarization to constitute a parallel type bimorph 8 An electrode 9 with the inside diameter of d/3-d compared with that (d) of the piezoelectric element is formed on the piezoelectric elements 6, 7 Two heads are fixed on the part near the ends 12, 13 of the piezoelectric element 6 while an intermediate electrode is divided at the intermediate point 14 The bimoprh 8 is supported by supporters 15 at the intermediate point 14 to form two cantilevers Through these procedures, any crack or breakdown due to stress concentration or any fluctuation of displacement characteristics may be prevented from happening compared with those in case of overall electrode since there is no electrode at all near the ends of the cantilevers

Deflecting arm device

Abstract: PURPOSE:To suppress positively an unnecessary vibration by sticking an intermediate part of a supporting member roughly orthogonal to a displacement direction and a longitudinal direction, in the vicinity of the tip part of a bimorph piezoelectric element, fixing both end parts to a substrate through the second piezoelectric element, and impressing a voltage corresponding to a deflecting voltage. CONSTITUTION:The first piezoelectric element 20 is displaced in accordance with an impressed deflecting voltage, and simultaneously, a voltage corresponding to the deflecting voltage is impressed to terminals 31, 32 and 33, 34, too, and a voltage by which the polarizing direction in the second piezoelectric elements 29, 30 is promoted in the deflecting direction of the tip part of the first piezoelectric element 20 is impressed. As a result, the second piezoelectric elements 29, 30 expand and contract in the deflecting direction of the first piezoelectric element 20, a displacement quantity of the second piezoelectric elements 29, 30 is added to a deflection quantity of the first piezoelectric element 20 and the deflection quantity is increased, and an unnecessary vibration of the first piezoelectric element 20 is suppressed by an elastic force of the second piezoelectric elements 29, 30.

Measuring electrode equipped with stirring mechanism due to piezoelectric vibrator

Abstract: PURPOSE:To attain to enhance the accuracy of a measured value and to prevent the adhesion of a substance to a measuring electrode by mixing a liquid in the vicinity of the measuring electrode, by providing a bimorph vibrator in the vicinity of the measuring electrode while connecting an AC power source to said vibrator. CONSTITUTION:When AC voltage of about 10-150Hz is applied to a bimorph vibrator 4, the vibrator 4 is vibrated at the central part thereof at the frequency thereof. The pressure wave generated by this vibration is different from ultrasonic vibration and comes to a relatively large pressure wave by the bimorph vibrator. This pressure wave is impinged to an electrode 1 to prevent the contamination thereof or formation of a substance adhered to said electrode 1 and mixing effect caused by relatively large vibration is generated. In addition, amplitude can be made large by bring the back side of the vibrator 4 into communication with the open air through an air passing pipe 8 and can be easily altered by inserting a throttle valve 9 into the air passing pipe 8. By vibrating the vibrator 4 as mentioned above, a liquid is sufficiently mixed to make it possible to enhance the accuracy of a measured value and the formation of a substance adhered to the electrode 1 can be prevented.

Piezoelectric device for drive

Abstract: PURPOSE:To enhance the accuracy of the moving distance of a piezoelectric element by disposing drive means having a bimorph structure by engaging means on the outer periphery of a rail, moving it along the rail. CONSTITUTION:Since the warpage of the first piezoelectric element 18 of a piezoelectric device 10 and the bendability of the second and third piezoelectric elements 19, 20 can be arbitrarily selected by dividing a pair of piezoelectric elements 12, 13 having a bimorph structure, the accuracy of the moving distance per one cycle of the piezoelectric device 10 can be enhanced. The device 10 can be driven along the rail 24 merely by disposing a pair of the devices 10 to be engaged with movable members 25, 26 at both sides of the rail 24, and the devices 10 are symmetrical. Accordingly, the moving operation is stabilized to substantially set the size of the rail 24.

Head device for magnetic recording and reproducing device

Abstract: PURPOSE:To always keep excellently the contact between a tape and a magnetic head by shifting a support of an electro-mechanical transducer element from a line tying a turning center of a turning body and the magnetic head. CONSTITUTION:The plain view of a major part of a bimorph part of a head device of a VTR is shown in Fig. A head mounting part 211 projected in a direction orthogonal to the lengthwise direction of the bimorph 21 is provided to one end of the bimorph 21 and a magnetic head 7 is fitted to the mounting part 211. The other end of the bimorph 21 is a support 212 of the bimorph 21 (shown in hatched lines in Fig.) and supported by the turning body. The structure of the bimorph 21 and the application of voltage are the same as the known method as shown in the side view when the bimorph 21 is displaced upward.

Piezoelectric device for driving

Abstract: PURPOSE:To obtain the titled device of simple construction and large driving power by a method wherein the driving power of a driving means having the bimorph structure is increased by utilizing an electric field acting on the region between an electret and an electrode. CONSTITUTION:A pair of piezoelectric elements 2 and 3 having the bimorph structure are connected in series with a control circuit; when a required voltage is impressed across electrodes 7 and 9 of the elements 2 and 3, a deflection force F1 in the direction of an arrow 16 is given to the piezoelectric device 1 with piezoelectric bodies 6 and 8 different in electric polarity. Further, when a required voltage is impressed across electrodes 5 and 9 by means of the other control circuit by making the electrode 9 of the element 3 as the electrode of the electret 4, an attraction force F2 in the direction of an arrow 15 is imparted between the electret 4 and the electrode 5.

Printer head of printer

Abstract: PURPOSE:To improve printing speed and the durability of bimorph piezoelectric elements by providing a plastic electrode on the external surfaces of two piezoelectric films sandwiching an intermediate electrode and inputting a printing voltage signal between the plastic electrode and the intermediate electrode. CONSTITUTION:A printer head 5 is composed of an intermediate electrode 13 and plastic electrodes 14, 15 sandwiching piezoelectric films as bimorph piezoelectric element. Voltage is applied among the electrodes 13, 14 and 15 to distort the crystal of piezoelectric elements so that the whole crystal is flexible in a printing direction. In this case, if a voltage to be applied is selected for any high frequency, it is possible to easily increase the printing speed of the printer head 5. In addition, the plastic electrode is made of plastic containing dispersed powdered piezoelectric material. Therefore, said electrode has a buffer action so that a uniform voltage can be applied to piezoelectric film to damp an impact, and also has an effect to prevent damage caused by contact with any other article.

Production for surface potential sensor element

Abstract: PURPOSE:To make a tuning fork unnecessary to simplify the constitution of a sensor element and facilitate producing it, by using a piezoelectric bimorph as the surface potential sensor element of a contactless vibrating reed electrometer CONSTITUTION:The surface potential sensor element of the vibrating reed electrometer consists of a piezoelectric bimorph 10 such as piezoelectric ceramics or the like whose one end is fixed to a vessel 9 of an electromagnetic shield through a fixing member 11, a needle-shaped electrode 5 consisting of a good conductor in the free end, etc An oscillating capacity is generated by the electrode 5 and a face to be measured whose potential is measured through a hole of the vessel 9 facing the electrode 5 by the bimorph 10 oscillated by AC driving Consequently, a tuning fork or the like is unnecessary to simplify the constitution of the surface potential sensor element of the contactless vibrating reed electrometer, and its production is facilitated

Magnetic head device

Abstract: PURPOSE:To increase the effective length compared with the conventional value by increasing the area of a support part for an electromechanical transducing to element reduce the effect of the uneven thickness of an adhesive layer of the support part and therefore obtaining the desired attachment accuracy although the support length is decreased. CONSTITUTION:A bimorph 21 contains two piezoelectric elements held among three electrode layers and also has a long bar 211 containing a rotary magnetic head 15 at the tip part together with arm-shaped bars 212 and 213. Then the bimorph 21 is supported by a rotor (not shown in the figure) via a support part 214 which supports directly those bars 212, 213 and 211. In other words, a part D shown by oblique lines in the figure is equal to the area of the support part of the bimorph 21. In such a constitution, said area of the support part increases greatly. Therefore the effective length (u) can be increased compared with the conventional value for replacement of a magnetic head by decreasing the support length (s).

Color pickup device provided with vibration means

Abstract: PURPOSE:To obtain a color video image without decreasing resolution, by vibrating at least a part of an image-focusing or photographing optical system and also by fetching in the signal in the photographing part corresponding to each picture element in synchronization with the vibration. CONSTITUTION:A stripe shaped 3-primary color filter 17 is installed slightly in front of an image-pickup face 5a of a solid-state image pickup sensor 5, and both upper and lower ends of the 3-primary color filter are fixed securely at the front ends of bimorph vibrators 18 and 19. Bimorph driving voltage is impressed from a lead wire to respective bimorph vibrators 18 and 19 through a driving circuit 21. By this bimorph vibration, the 3-primary color filter vibrates only for a picture element pitch, the picture element signal is sequentially read out in the order of R, G and B, and the signal is stored in respective frame memory units 10R, 10G and 10B. Picture information which is stored in the frame memory in this manner is indicated in a color CRT11 for monitoring while it is swept by horizontal and vertical deflection outputs.

Bimorph electromechanical transducing element

Abstract: PURPOSE:To provide driven bodies with sufficient displacement and to keep their deflection angle within tolerance by a method wherein electrodes provided on the both surfaces are constructed so that no non-deflection regions may be present resulting from gaps between the electrodes in the entire width of the main body. CONSTITUTION:Between the outer electrodes 11, 13 of one piezoelectric element 1 is a linear sideways gap 15 separating them from each other. A similar gap 16 separates an outer electrode 12 from an outer electrode 14 in the other piezoelectric element 2. With regions of no deflection absent in the bimorph piezoelectric elements 1, 2, when the displacement of a video head is 50mum in 50% of the counter electric field, they meet the record carrier 4 at 0.1 deg. (generally called the angle of deflection), which is a satisfactory value for general use.

Non-contact temperature sensor

Abstract: PURPOSE:To attain the miniaturization and wt reduction of the titled sensor and to enhance the reliability thereof, by constituting an optical chopper from the first optical slit plate provided to the pyroelectric sensor vibrated in parallel to a light receiving surface by a bimorph displacement element and the second slit plate provided to a package CONSTITUTION:Bimorph displacement elements 30a, 30b are formed by forming two pairs of slits 121-124 to two mutually opposed surfaces of a ceramic frame body 10 coming to a package main body and attaching supports 32 (321-324) to both ends of bimorph vibrators 31a, 31b while a pyroelectric sensor 60, wherein a slit plate 61 is mounted on the fixing seat 50 integrated with a flexible printed board 40, is mounted to said bimorph displacement elements 30a, 30b Then, a substrate 40 is inserted between the elements 30a, 30b to be received in the frame body 10 and an optical chopper is constituted of the slits 121-124 and the slit plate 61

Optical path opening and closing device

Abstract: PURPOSE:To open and close an optical path with high efficiency by providing a fixed plate with plural mutually parallel light shielding parts, and supporting a plate having similar light shielding parts thereupon at both ends with a flexible polymer bimorph materials, and exciting it by an AC power source. CONSTITUTION:The light shield plate 11 having plural mutually parallel light shielding parts 11a is supported by fixing members 14a and 14b. The light shield plate 12 having light shield parts 12a similar to those of the light shielding plate 11 is arranged in parallel to the light shielding plate 11, and its both ends 13aa and 14bb are supported by flexible high polymer bimorph materials 13a and 13b. The bimorph materials 13a and 13b are driven by the AC power source 15 and oscillated by displacing them as shown by an arrow A. Thus, the opical path is opened and closed with high efficiency.

Force detection apparatus

Abstract: PURPOSE:To facilitate the detection of a wide range of force, by forming a piezoelectric body as a bimorph type and connecting an oscillator, which has frequency in the vicinity of the unresonant frequency of the piezoelectric body, to the piezoelectric body while detecting the change in the impedance amount of the piezoelectric body when force is applied. CONSTITUTION:A bimorph type piezoelectric body 1 is fixed at one end thereof and made free at the other end thereof. A frequency oscillator 3, which applies frequency corresponding to one higher than the frequency at an unresonant point generating when external force is applied to the piezoelectric body 1, is connected to the piezoelectric body 1 through series impedance 2. The signal amplified by an amplifier circuit 4 is converted to a DC signal by a rectifier circuit 5. If the voltage signals from the rectifier circuit 5 and a reference voltage generator 7 are respectively inputted to a differential amplifier circuit 6, the output voltage thereof is zero when no external force is applied and, when external force is applied, output voltage corresponding to the change in impedance is obtained.

Information signal reproducer

Abstract: PURPOSE:To perform the satisfactory tracking by providing a correcting voltage generating circuit which produces the prescribed correcting voltage to a driving circuit for driving bimorph element. CONSTITUTION:A correcting voltage generating circuit K produces the correcting voltage which is similar to the hysteresis characteristics of the drive voltage- displacement amount of a bimorph element 4. The correcting voltage V2 given from the circuit K is supplied to an operational amplifier 3 which constitutes a driving circuit 7 for element 4 and added to the drive voltage given from an LPF2. Thus it is possible to give a displacement to a torary magnetic head 5 in the direction approximately orthogonal to the scan direction of a rotary magnetic head 5 and approximately in proportion to the drive voltage applied to the element 4. This ensures the satisfactory tracking with an information signal reproducer.

Infrared ray detecting apparatus

Abstract: PURPOSE:To miniaturize the titled apparatus and to prevent the deterioration of a bimorph by composing an optical chopper with the bimorph and a shutter driven by said bimorph. CONSTITUTION:Infrared ray made incident from a round hole window 3 attains an element 5 through a small hole 6a provided at the upper surface of an internal shield case 6. Said apparatus is constituted with the shutter part 7 arranged near the hole 6a of the case 6 and the first and second bimorphs 8a, 8b for moving the shutter part. The part 7 repeats the opening and closing states periodically by driving circuit, and the element 5 outputs a signal corresponding to the relative temp. difference between the part 7 and a material to be measured. A diode 11 placed between the bimorphs 8a, 8b detects approximately the temp. of the part 7 by utilizing the temp. characteristic.