Showing papers on "Bimorph published in 1983"

Optomechanical bimorph actuator

Abstract: An optomechanical bender bimorph–a device which responds to incident illumination by bending–is described. Expressions for the bimorph action are derived and the results of tests are reported.

Bimorph piezoelectric flexible mirror: graphical solution and comparison with experiment

Abstract: The equation of state of a flexible piezoelectric mirror of rectangular cross section has been solved for arbitrary electrode voltages V(x, y) at a point x, y on the mirror. The corresponding displacement W(x, y) has been plotted in three dimensions for four forms of the voltage distribution. These surfaces give the actual shape of the distorted mirror. Contours of equal displacement W(x, y) = constant have also been plotted. It is found that these contours reproduce quite well the interferograms measured by Steinhaus Lipson [ J. Opt. Soc. Am.69, 478 ( 1979)] for comparable forms of the voltage distribution. The dynamic problem for a time-dependent voltage V(x, y; t) has also been solved. At certain frequencies resonant behavior is exhibited.

Differential pressure vortex sensor

Abstract: A differential pressure sensor (10) adapted specifically for use with vortex shedding flowmeters which can be used in small spaces, uses a bending beam (60) for providing an electrical signal proportional to differential pressures between two oppositely facing diaphragms (40A, 40B). The diaphragms deflect under differential pressure and cause the beam (60) to be bent. The diaphragms have low mass and have a support structure (43) between them, carrying spring clips (50) which load one end of the bending beam (60). The other end of the bending beam (60) is then supported so it cantilevers from its mounting or support (61, 62) and upon movement of the diaphragms under differential pressure the beam (60) will bend. The signal can be derived by using a bending element made of a piezoelectric "bimorph" beam, which provides a voltage output as it bends, a strain gauge sensor on a beam, or an optical sensor, such as a fine fiber which deflects and provides an optical output may be used, as well as similar devices. Preferably, the sensor is a piezoelectric bimorph beam because of the direct electrical signals provided, which result from bending of the beam (60).

Solid state image sensing device

Abstract: A solid state image-sensing device is disclosed which includes a base board fitted with a plurality of connection pins, an interline transfer charge coupled device (IT-CCD) serving as an area sensor, and a pair of bimorph piezoelectric vibrating elements which jointly vibrate to periodically vibrate the IT-CCD relative to an incoming image light in a plane substantially parallel with the surface of the base board, and wherein the piezoelectric vibrating elements are elastically held above the base board by support plates having a spring action, thereby efficiently vibrating the IT-CCD.

Bimorph electromechanical transducer and control circuit device therefor

Abstract: An electromechanical transducer comprising a bimorph and applicable, for example, to a helical scan type VTR for displacing a magnetic head into alignment with a magnetic track on a videotape, together with a control device for the electromechanical transducer. The bimorph is displaceabe at a free end portion thereof in response to a voltage applied thereacross. The control device comprises a sensor for sensing a displacement of the transducer, a drive circuit for driving the bimorph in response to externally derived drive signals which include a head position compensation drive signal, a feedback circuit for applying negative feedback to the drive circuit in response to a sensed displacement, and a low pass filter for cutting off high frequency components of the drive signal. The feedback circuit includes a high pass filter for reducing frequencies lower than first order resonance frequency.

A flat piezoelectric polymer film loudspeaker as a multi-resonance system

Abstract: A flat diaphragm full-range loudspeaker utilizing a piezoelectric polymer is described. This loudspeaker is characterized by an excellently simple constitution and multiresonance response characteristics. Since the fundamental resonant frequency of a loudspeaker should be as low as possible, it is convenient to utilize the flexural vibration of a bimorph diaphragm. The input-output relation of a bimorph diaphragm radiator in a multi-resonance frequency region is studied theoretically, and the formula for estimating output sound pressure level for the resonant peak is given. This is also examined experimentally.

Osteogenesis induced by bimorph polyvinylidene fluoride films

Abstract: The first callus formation induced by piezoelectric polyvinylidene fluoride (PVDF) film has been reported in 1976 by Susuki. Nevertheless, the mechanism of action of induced osteogenesis remains still mysterious. So, the study of the influence of the nature of the stress exerted onto the piezoelectric film has been undertaken.For this purpose, the osteogenic power of two kinds of piezoelectric PVDF films has been followed:- monomorph PVDF films sensitive to all stresses,- bimorph PVDF films only sensitive to bending stresses.PVDF films of various thicknesses - 175 μ, 250 μ, 450 μ-were implanted on a series of white new-zealand mature male rabbits. Each PVDF film was implanted round the right femoral diaphysis and a reference PVDF film round the controlateral femur. Osteogenesis was controlled by X rays and quantitative analysis of alkaline phosphatases in the blood. With bimorph films, a greatest amount of callus and an important remodelling of the cortical bone were observed. The new osteons are perpendi...

Magnetic recording and reproducing device

Abstract: PURPOSE:To compensate the deviation of tracking due to a temperature characteristic and a secular change, by detecting the variance of the voltage value of the operating point of a bimorph plate in the exit part of a track and applying a voltage for compensation to the bimorph plate. CONSTITUTION:The voltage of the operating point of a bimorph plate 7a is denoted as V'3. The comparison output V'3 from a comparing circuit 17a is sampled in a sampling and holding circuit 85a just before a switching pulse PX falls, and this output is compared with a reference voltage in a comparing circuit 86a. A positive voltage is supplied as the comparison output to a counter 87a, and components corresponding to one switching pulse PX are substrated, and a counted value smaller than the preset value of the counter 87a by 1 passes a digital-analog converter 88a and is supplied as a compensating voltage to the bimorph plate 7a through an adding circuit 15a, and a head 6a traces the track accurately even in the entrance part of the track.

Control of microscopic displacement for bimorph type piezoelectric body displacement device

Abstract: PURPOSE: To reduce influences by the hysteresis of a bimorph and to facilitate the control of a microscopic position in case the bimorph is maintained at the constant position for a long time by a method wherein the bimorph constituted of two sheets of piezoelectric body is controlled so as to displace in the reverse direction. CONSTITUTION: Piezoelectric bodies 2 and 3 are adhered on both surfaces of a metal plate 1 provided with a bimorph type piezoelectric body displacement device and the fixing ends of the piezoelectric bodies 2 and 3 are fixed on a support-fixing part 6. Lead wires 4 are connected to an electrode near the fixing ends of the piezoelectric bodies 2 and 3 and both ends U and W of a power source 5 are connected in between the lead wires 4 and 4. The removable voltage and V of the power source 5 is connected to a lead wire 4' connected with the metal plate 1. By this constitution, in case voltage supplied from the power source 5 in the reverse direction is impressed on each of the piezoelectric bodies 2 and 3, the displacement of the piezoelectric bodies 2 and 3 is set in the reverse direction and a bimorph is maintained at a constant position for a long time, influences by the lapse of time and the hysteresis of the bimorph are eliminated and the control of the microscopic position is facilitated. COPYRIGHT: (C)1984,JPO&Japio

Deflection arm device

Abstract: PURPOSE:To suppress unnecessary vibration and to improve response characteristics, by the constitution that the vicinity of free end of a bimorph piezoelectric element is bonded with a piezoelectric ceramic element which is orthogonal to the lengthwise direction of the bimorph element and both ends of which are fixed and a deflection accelerating voltage is applied to the piezoelectric ceramic element. CONSTITUTION:In a bimorph piezoelectric element 10 consisting of piezoelectric ceramic elements 1, 2 and electrodes, one end is fixed to a support stand 30 and a lower side near the other end is bonded with the center upper surface of a piezoelectric ceramic element 40 located to a direction orthogonal to the long- side direction of the element 10. Electrodes are bonded on both major planes of the element 40 and both the ends are fixed to the fixed stand 30. A prescribed deflection voltage is applied to the element 10 via terminals 11 and 12 and a voltage which assists the deflection at the free end of the element 10 is applied to the element 40 via terminals 41 and 42. The element 40 eliminates the the unnecessary vibration and improves the responsiveness.

Method of manufacturing polymeric piezoelectric films by pressing

Abstract: The invention relates to a transducer piezoelectric polymer manufacturing process by forging. The invention aims to achieve, by crushing of a preform, a radial orientation of the molecular chains composing the polymer relative to the center of pressure. The invention is particularly applicable to the manufacture of bimorph or piezoelectric transducers used in electroacoustic devices.

Vibration suppressing device for bimorph piezoelectric element

Abstract: PURPOSE:To correct the displacement of a bimorph piezoelectric element from a deflection with respect to the prescribed deflecting voltage by feeding back a voltage which correspond to the displacement to the bimorph element when the element is deflected to the position displaced from the deflection. CONSTITUTION:When the deflecting voltage of a tracking signal source 60 is 0V, in case that a bimorph piezoelectric element 10 is moved by DELTAD by the initial state, the deflection DELTAD is detected by a displacement sensor 30, and a voltage becoming DELTAV to match the displacement DELTAD is outputted by a comparator 50. The voltage DELTAV is inputted as a voltage V through a DC amplifier 70 to a mixer 80. In the mixer 80, the voltage is inverted and is inputted as -V. The voltage outputted from the mixer 80 becomes the deflecting voltage of the value applied with the deflecting voltage 0(V) and the voltage -V(V) from the tracking signal source 60, and a deflecting voltage for providing the displacement of the inverted direction of the sign is applied as the displacement of DELTAD to the element 10. Accordingly, the element 10 is returned to its initial state.

A Piezoelectric Single-Plate Bending Vibrator Using Interdigital Electrodes

Abstract: This paper presents an advanced design of the piezoelectric single-plate bending vibrator, in which interdigital electrodes formed in parallel to the plate-length are used for both poling treatment and excitation of vibrations. The dependences of the capacitance ratio of the vibrator on the electrode dimensions and the poling-voltage are clarified. It is demonstrated that the proposed vibrator exhibits the performance superior to the conventional bimorph vibrator.

Cooling device for electrical parts

Abstract: PURPOSE:To enable to protect a bimorph fan, which lacks in thermal stability in itself, from heat by comparatively keeping apart from an electrical parts as well as to perform an effective cooling by a method wherein the bimorph fan is housed in a cylindrcial body to act as a wind channel provided with openings at positions, and is fixed with the cylinder body. CONSTITUTION:In a square cyliner 1 having an opening 1a toward an electrical parts to be cooled is housed a bimorph diaphrgm 2 in a direction prolonged in parallel nearly with the axial direction and the bimorph diaphragm 2 is adhesion-fixed on the top surface and undersurface of the square cylinder 1 at the upper and lower edge faces of a fixing part or an electrical connection part 3 on the bimorph diaphragm 2. When alternating-current voltage is impressed on a macromolecular piezo-electric film in the bimorph diaphragm 2 through the intermediaries of lead wires 6a and 6b and the connection part 3, the bimorph diaphragm 2 is vibrated right and left with the fixing part 3 as the supporting point, thereby enabling to send wind out toward A direction from the opening 1a, while air is being breathed in from openings 1b, 4a, 4b, 5a and 5b. By this wind, a forcible cooling for the electrical parts to be cooled, that is aimed at in this invention, is performed.

Piezoelectric element bending oscillator and piezoelectric filter

Abstract: PURPOSE:To obtain a piezoelectric single element bending oscillator having a small capacitance in matching with a conventional bimorph oscillator, by providing cross finger electrodes so that the lengthwise direction of the fingers is in parallel with the direction of contracted and shrinked strain of the bending oscillator. CONSTITUTION:Figure shows electrodes 4, 5, 6 formed on one side of a piezoelectric electrode 1. An N6 member is used for the piezoelectric plate 1, as the size, length l=18.0mm., width W=9.6mm., thickness t=0.7mm. are adopted, the interval (p) of electrodes is taken as 0.5mm., width of electrodes/interval is taken as 0.5, and the polarization is done at 50kV/cm for a three-terminal filter. In taking one electrode 11 as an input and another electrode 12 as an output, the frequency characteristics of the attenuation are measured. The result is that the center frequency is about 7kHz and the attenuation is 0.7dB. Thus, a filter having low loss at a comparatively low frequency is realized with a comparatively small size. Since bonding for a bimorph oscillator is not required, the dispersion in characteristics is less and the stability is improved.

Electronic flash device for changing irradiation angle

Abstract: PURPOSE:To change an irradiation angle of a flash device, by applying the control voltage to a reflector made of a piezoelectric material, and varying its shape. CONSTITUTION:A piezoelectric material (for instance, PVDF) Q is of so-called bimorph constitution consisting of two layers 1, 2. Also, Al is respectively vapor-deposited to faces (a), (b) and (c) made of the piezoelectric materials 1, 2, and an electrode is formed, respectively. Voltage is applied to each electrode (a)-(c) face through an electric power source E and a switch S. When the switch S is closed in a state that Q of the bimorph constitution is formed like a curved face and both end parts A, B are fixed, voltage is applied between respective electrodes, and Q is deformed as shown by an alternate long and two short dashe's line Q'. This deformation is varied by the magnitude of the voltage, and the shape such as thickness, etc. of the piezoelectric materials 1, 2. When application of the voltage is stopped, Q is returned to the shape of a full line again.

High speed scanning arrangement for video tape recorder

Abstract: In a helical scan video recorder in which the magnetic heads are arranged on bimorph piezoelectric actuators it may be desirable, in order to counteract depolarization of the piezoelectric elements, to bias these elements. This is possible without the use of additional slip rings if the electrode to which the drive voltage is applied is connected, via a diode, to the electrode to which the bias is applied and the bias is applied, alternately with the drive voltage, at instants at which the associated magnetic head is not used. If the (lower) drive voltage is applied the diode is cut off and the bias is isolated from the drive.

Floating device of magnetic head

Abstract: PURPOSE:To always keep the distance between a magnetic head and a magnetic disk at a prope fixed level in opposing each other, by combining a photoelectric conversion element with a bimorph element. CONSTITUTION:A magnetic head 2 is buried into a holder 3 in opposition to the surface of a magnetic disk 1, and at the same time a light emitting element 4 and a photoelectric converting element 6 are buried into the holder 3. When the distance l is set at a proper level between the disk 1 and the head 2, the light of the element 4 is reflected at a reflecting point (a) of the disk 1 and then made incident to a converting element 5. A bimorph element 6 containing electrodes 6' and 6'' for application of voltage connects the holder 3 and a holding substrate 7. Then the voltage based on the level of the output of the element 6 is applied to the element 6 to control the position of the head 2. As a result, the distance l can always be kept at a proper level.

A Highly Sensitive Displacing Device Using Piezoelectric Bimorph with Double-Support Structure

Abstract: In order to improve displacing devices, new methods for supporting a bimorph element with a double-support structure were investigated. Consideration of bending properties revealed that, when the bimorph element was bent, the cross-sections at both of the bimorph element's ends rotated. A double-support bimorph element with U-shaped metal plates at each end was designed, the result being used. It was found that the displacement for the double-support bimorph with U-shaped metal plates was approximately 4 times larger than the displacement for a conventional double-support bimorph.

Magnetic head driving element

Abstract: PURPOSE:To suppress the hysteresis phenomenon of the bimorph voltage versus displacement characteristics, by forming a bimorph through the combination of a piezoelectric element having a high piezoelectric constant and another piezoelectric element having a linear voltage versus displacement characteristic in a prescribed ratio of thickness. CONSTITUTION:As a piezoelectric element 3, a piezoelectric element having a large piezoelectric constant d31 is used, and as an element 3, a piezoelectric element having a small piezoelectric constant d'31 but a sufficiently small hysteresis and an excellent linear voltage versus displacement characteristic is used, and the excellent linear voltage versus displacement characteristics are obtained by suppressing the hysteresis of a bimorph 1 at sufficiently small level, and the thickness l'2 of the element 4 is made sufficiently thinner than the thickness l2 of the element 3 by taking the Young's modulus into consideration, allowing to increase the displacement xsi' to a drive voltage Va sufficiently.

Manufacture of piezoelectric thin film type electric- mechanical displacement transducer

Abstract: PURPOSE:To form a piezoelectric thin film and electrode layers at a fine region without procedures of photolithography and etching by forming a bimorph structure on a cantilevered insulating layer produced on the face of a semiconductor substrate. CONSTITUTION:After formation of an SiO2 insulating layer 12 on the face of a semiconductor substrate 11, a U-shape opening is provided on part of the insulating layer 12 by photolithography and etching. The cantilevered SiO2 layer 15 is then produced with a cavity 14 formed by etching on the substrate 11 through the opening 13. A lower electrode layer 16, piezoelectric thin film 17 and upper electrode layer 18 are produced successively in laminated structure. The electrode layer 16, thin film 17 and electrode layer 18 are formed only on the cantilevered layer 15 extended out so that excessive parts fall into the cavity 14 during evaporation process. Therefore, there is no need for patterning using a mask.

Supporting structure of piezoelectric type electro- acoustic transducer

Abstract: PURPOSE:To improve the shock resistance of a piezoelectric electro-acoustic transducer having flat output sound pressure frequency characteristics, by supporting elastically the transducer having its end of one side connected to the other end of an expanding/contracting member such as a spring, etc that is fixed to a back cover of a timepiece CONSTITUTION:A diaphragm 33' made of a polymer material film obtained by thermoforming constitutes a piezoelectric electro-acoustic transducer 41 together with a bimorph oscillator 32 A spring 38 ensures an electric connection between the electrode of the oscillator 32 and a module 30 That is, the electric signal delivered from the timepiece module 30 via springs 38 and 39 is transmitted to the transducer 41 and generates audible sound Furthermore the diaphragm 33' is fixed by compressing a packing 45 set between a back cover 43 and a module support frame 44 This also assures the water tight structure

Voltage to pressure transducer

Abstract: A pressure control system for maintaining pressure of a gas within a container at a preselected value. The volume within the container is connected to a source of pressurized gas. An external portion of the container is spherical shaped and has an orifice formed therein through which gas is exhausted from the volume. A piezoelectric bender bimorph has a portion thereof adjacent the exhaust orifice. Feedback means connected between the volume and the piezoelectric bender bimorph function to vary the position of the bimorph relative to the exhaust orifice to maintain pressure within the container at preselected value.

Bonding type piezoelectric component and its manufacture

Abstract: PURPOSE:To reduce the bonding time and to obtain an excellent bonding type piezoelectric component, by heating a laminating body overlapping a piezoelectric plate and a metallic plate via solder higher than the melting point of the solder and cooling the body after pressing CONSTITUTION:A paste solder 14 is applied to the bonding surface of a piezoelectric plate 11 with screen printing or coating Then, the metallic plate 12 to be bonded is prepared for the plate 11 applied with the solder 14, the plates 11, 12 are overlapped via the solder 14 to obtain a laminating body 1 The body 1 is kept a higher temperature than the melting point of the solder and the solder is completely bonded on the entire bonding surface with pressing The solder is fixed with air cooling, the bonding is finished to obtain a unimorph type piezoelectric component 10 Similarly, a bimorph type piezoelectric component 20 bonded with two piezoelectric plates 21, 31 and a bimorph type piezoelectric component 30 bonded with two piezoelectric plates clipping a metallic plate, can be manufactured

Multicore optical switch

Abstract: PURPOSE:To make an optical switch miniaturized, by using a piezoelectric plastic in a movable part. CONSTITUTION:A fixing part 4 where optical fibers 5a and 5b are arranged in two lines and have end faces trued up and held by the plastic is provided, and optical fibers 2 which are arranged in one line and have end faces trued up are provided, and a movable part 1 of a bimorph which holds these optical fibers 2 and uses a piezoelectric plastic 1c for the purpose of protecting optical fibers 2 is provided. The direction of the voltage impressed to the movable part 1 is switched to drive the movable part 1, and end faces of optical fibers of the movable part 1 are matched to end faces of optical fibers 5a or 5b in one line of the fixing part 4. As a result, the light is transmitted to fibers 5a or 5b from fibers 2.

Piezoelectric electroacoustic converter

Abstract: PURPOSE:To improve the reliability in comparison with two piezoelectric sheets sticked with an adhesive, by constituting bimorph equivalently through the use of a flexible piezoelectric sheet CONSTITUTION:When polarization is processed to a flexible piezoelectric sheet incorporating inorganic or organic ferrodielectric material, or high polymer piezoelectric material under a specified condition, the polarization is processed from one surface of the piezoelectric sheet to the half-way toward thickening direction Based on this knowledge, one flexible piezoelectric sheet is used and the sheet is polarized in such a way that the front and back sides are taken as one electrode and the center in the thickening direction is taken as another electrode

Rotary head device

Abstract: PURPOSE:To prevent the mistracking due to the natural oscillation by detecting the natural oscillation of a bimorph element and producing the electric signal corresponding to said natural oscillation in order to attenuate the natural oscillation CONSTITUTION:A plan and a side view are shown for the periphery of the attachment part of a video head element of a rotary head device A planar oscillation detecting piezoelectric element 7 is set on the center surface of a flat plate type bimorph containing a video head element 5 attached to a free end The detection output of the element 7 is extracted in a rotary state Therefore a brush ring system or a rotary transformer is applied

Deflecting device of solid-state image pickup element

Abstract: PURPOSE:To obtain a deflecting device of solid-state image pickup element which can be produced in an easy way of production with excellent reliability and mechanical strength, by fixing the 1st bimorph oscillator to the end face of one side of a basement and a solid-state image pickup element and the 2nd bimorph oscillator to the end face of the other side of the basement and the solid-state image pickup element respectively to apply an electric field to these bimorph oscillators and then moving with a shift the basement and the solid- state image pickup device in parallel to each other. CONSTITUTION:An electric field is applied to bimorph oscilators 21 and 22 so that they are bent to the right side respectively, and as a result a solid-state image pickup element 11 moves together with the oscillators 21 and 22 to the right side and in parallel to a basement 30. In this case, the element 11 never tilts to the basement 30 compared with a state obtained before the electric filed is applied for deflection since the element 11 moves in parallel to the basement 30. In case a backward electic field is applied, the element 11 moves horizontally and to the left side. Thus the deflection is attained. A high level of image resolution is obtained for a solid-state image pickup device owing to its consecutive operation.

A bimorph microphone using composite piezoelectric polymer

Abstract: A microphone with simple construction, using a bimorph diaphragm made from a composite piezoelectric polymer sheet, is described. A composite of lead-titanatezirconate powder and polyvinylidenefluoride and/or fluorinated rubber is useful, because its characteristics can be widely controlled by varying its composition, and it is easy to mold into a sheet. A symmetric bimorph structure using two composite polymer sheets is convenient for the structure. Microphone response is calculated, and it is concluded that a microphone, some 10-20 mm in diameter, shows of -70•`-90 dB response (re volt/microbar) as a telephone microphone. Several experiments confirm these results.

Electro-acoustic transducer of piezoelectric type

Abstract: PURPOSE:To utilize the oscillation energy effectively and to smooth the output sound pressure frequency characteristics, by adhering a diaphragm so that it covers whole surface of one of electrodes of a bimorph vibrator made by adhering two pieces of piezoelectric ceramics CONSTITUTION:A bimorph vibrator is constituted by adhering two pieces of piezoelectric ceramics 32a and 32b Each of the ceramics 32a and 32b are provided with electrodes 321, 322, 323 and 324 The electrodes 321 and 324 are made to be input electrodes of the vibrator 32 A polymer material 33 having an electrode 34 on one side of it is adhered so that it covers whole surface of the electrode 324 of the vibrator 32 to constitute a piezoelectric type electro-acoustic transducer 31 Due to the use of the polymer material 33, the Young's modulus is made smaller, the extension and compression of the vibrator 32 according to distorted oscillation is made easier, and output sound frequency characteristics is made smoother