CN1928569A - Acceleration sensor, electronic device comprising the same, and acceleration measuring method - Google Patents

Abstract

There is provided an acceleration sensor that is capable of detecting acceleration with high precision and capable of reducing the size and cost due to its simple structure. The acceleration sensor comprises: a pair of cantilevers arranged on a same straight line or almost in parallel in such a manner that positions of fixed ends and free ends are arranged to face in opposite directions from each other, and each of the free ends has a degree of freedom to deflect along a same direction; a pair of magnetic field generating devices mounted respectively to each of the free ends for generating magnetic fields; and a pair of magnetic field detecting devices arranged to face each of the magnetic field generating devices, respectively, for detecting directions of the magnetic fields generated by each of the magnetic field generating devices.

Description

Acceleration transducer, the electronic installation that it is installed and acceleration measurement method

Technical field

The present invention relates to a kind of acceleration transducer, particularly about a kind of acceleration transducer of the measure of the change acceleration based on magnetic direction.And, the invention still further relates to a kind of electronic installation that this acceleration transducer is installed, relate to a kind of acceleration measurement method in addition.

Background technology

For the running-active status of measuring gage earnest body, the acceleration transducer of the acceleration of this object was measured in research and utilization in the past.It can utilize the airbag apparatus of operation part at industrial robot, automobile and be installed on the various fields such as hard disk drive on the portable computer.Specifically, in hard disk drive,, utilize for the destruction of suppressing data in the improper instantaneous measurement of moving or coming off and magnetic head is kept out of the way etc.And then, except free-falling, when measuring the inclination (angle) of the impact that puts on the machine or machine, also need to use acceleration transducer.

As the structure of the acceleration transducer of prior art, shown in patent documentation 1, generally adopt the method for measuring the strain that on structure, produces because of acceleration.Specifically, the center of criss-cross rubber-like support component (intersection point) gone up lead is installed, and, the askew measuring sensor of fixed installation on each beam of support component.Measure the distortion of each beam then based on the measured value of this askew measuring sensor, and measure the acceleration on each direction of principal axis (X, Y, Z).For example, use the semiconductor piezoelectric element to make up bridge circuit and measure its resistance value, perhaps, shown in patent documentation 1, use piezoelectric vibrator to measure, thereby measure acceleration according to crooked posting a letter the cycle as askew measuring sensor.

Patent documentation 1: specially permit communique No. 2732287

But, in above-mentioned method described in the prior art, must be at crosswise support component (spring) self or on its periphery, be provided with and take out measure the crooked electrode that uses during with signal, like this, and because the cause of its wiring, its structure complexity that becomes.And,, therefore, can not realize its miniaturization because askew measuring sensor is installed on support component.And then, owing on the spring position of support component, install or built-in askew measuring sensor, therefore, be subjected to the influence of spring deflection, be difficult to measure high-precision acceleration.

Summary of the invention

Therefore,, the object of the present invention is to provide and a kind ofly can measure acceleration accurately in order to improve described defective of the prior art, and simple in structure, simultaneously, can realize the acceleration transducer of miniaturization, cost degradation.

As the relevant acceleration transducer of a kind of one embodiment of the invention, it comprises: a pair of semi-girder, its stiff end is arranged on the same straight line or on the position of almost parallel mutually on the contrary towards free-ended direction, and each free end has can be along the degree of freedom of equidirectional deflection; The pair of magnetic field generation device, it is installed in respectively on each free end, and produces magnetic field; The pair of magnetic field measurement mechanism, it is established in the face of each magnetic field generation device respectively, and measures the magnetic direction by each magnetic field generation device.

At this, magnetic field measuring device comprises a pair of measurement mechanism respectively, that is, measure the measurement mechanism of the acceleration on the length direction of semi-girder, and the track when measuring along the deflection semi-girder forms face and perpendicular to the measurement mechanism of the acceleration on the direction of the length direction of described semi-girder.And then the track the when magnetic direction that magnetic field generation device produces is set at along the deflection semi-girder forms face and perpendicular to the direction of the length direction of described semi-girder.And for example, described acceleration transducer can be installed on the electronic installation based on hard disk drive.At this moment, preferably, the length direction that constitutes a pair of semi-girder of acceleration transducer is arranged on the surface level under the user mode of electronic installation.

According to foregoing invention, at first,, then produce revolving force according to each free-ended moment if on prescribed direction, produce acceleration, thus each overhanging beam of difference deflection.And the magnetic field generation device that is installed on each free end is tilted, along with magnetic direction also changes.At this moment, each free end staggers and by deflection in two direction of principal axis of regulation.At this, in the electronic installation of acceleration transducer is installed, under the user mode of this electronic installation, the X-Y plane of surface level for constituting by X-axis and Y-axis, vertical therewith direction is a Z-direction, then, when a pair of overhanging beam was set, at the acceleration on the X-direction (perhaps Y direction), a pair of overhanging beam was distinguished deflection round about to the Z-direction deflection and along X-axis (perhaps Y-axis), in addition, at the acceleration on the Z-direction to the equidirectional deflection.And,, measure the deflected of aforesaid a pair of overhanging beam by each magnetic field measuring device, thereby can measure two acceleration on the direction of principal axis as the variation of the magnetic direction of magnetic field generation device.Thereby,, therefore can constitute small-sized and acceleration transducer cheaply because it is simple in structure.At this moment, particularly can measure two direction of principal axis (promptly by being provided with, the length direction of overhanging beam (X-axis or Y-axis), and the track during along the deflection semi-girder forms face and perpendicular to the direction (Z-direction) of the length direction of described semi-girder) on the magnetic field measuring device of acceleration, thereby, can simplyr measure acceleration more accurately.

And, on the basis of said structure, when a pair of semi-girder has degree of freedom on the torsional direction of this beam, another magnetic field measuring device of the magnetic direction that measurement changes because of the twist operation of semi-girder is set in the face of the magnetic field generation device of at least one side.

And a pair of semi-girder is the tabular beam that the track when having perpendicular to this semi-girder deflection forms the plane of face.

Thus, when being accelerated on another axle (for example, the Y-axis) direction outside the described diaxon (for example, X-axis and Z axle), overhanging beam is reversed, and changes magnetic direction by magnetic field generation device thus.And, utilize other magnetic field measuring devices to measure the variation of magnetic direction, thereby can measure the acceleration on this another direction of principal axis (for example, Y-axis).Particularly pass through to form tabular beam, thereby, can produce aforesaid deflection easily and reverse thereby can produce aforesaid deflection easily and reverse for the acceleration on each direction of principal axis.Thus, can form the acceleration transducer that utilizes simple structure to measure the acceleration on three direction of principal axis, thereby can realize miniaturization and cost degradation.

And, in each free end, be divided into each magnetic field generation device a plurality of respectively and be provided with.Thus, the magnetic field measuring device that needn't intensive setting be provided with in the face of magnetic field generation device, and, can suppress to become the weight that produces greatly and the increase of cost because of magnetic field generation device.

And, when a pair of semi-girder roughly is same linearity ground and is provided with, make each free end be positioned at opposition side mutually and be provided with.At this moment, each stiff end with a pair of overhanging beam is fixed on the same support component for good.

Thus, can leave distance and the pair of magnetic field generation device is set, when measuring magnetic direction, can suppress the influence of the magnetic field generation device of opposite side by magnetic field measuring device.Thus, can improve measuring accuracy.At this moment,, thereby the shared space of support component is diminished, thereby realize lightweight, the miniaturization of sensor by fixing distolateral being fixed on the same support component that will stand facing each other.

And magnetic field measuring device is the magneto-resistance effect element that changes resistance value when importing magnetic field corresponding to this magnetic direction.And, when not quickening in any direction, make magneto-resistance effect element be approximately perpendicular to magnetic direction and be provided with.Thus, when utilizing parts such as giant magnetoresistance (GMR) element to measure the variation of magnetic direction easily, improve its measuring accuracy, its result can improve the measuring accuracy of acceleration.

And then described acceleration transducer comprises the differential voltage measurement mechanism, when it possesses the bridge circuit that is made of a pair of magneto-resistance effect element, measures from the differential voltage of this bridge circuit output.Thus, come the subtle change of measured resistance value by inquiry according to the differential voltage of bridge circuit, therefore, can further measure acceleration easily and accurately.

The acceleration transducer that another embodiment of the present invention is relevant, it comprises: the elastomeric element that has a degree of freedom on the direction at least; N pole-face and S pole-face are constituted by one and are installed on magnetic field generation device on the elastomeric element towards equidirectional; And be respectively provided to few each magnetic field measuring device that can measure magnetic direction in the face of the N pole-face of this magnetic field generation device and S pole-face; Wherein, each magnetic field measuring device is formed by the magneto-resistance effect element that changes resistance value corresponding to magnetic direction respectively, and the magnetic direction that can measure is set simultaneously becomes same direction.

According to foregoing invention, at first, when produce quickening on prescribed direction, elastomeric element is by deflection, and the N pole-face of magnetic field generation device mounted thereto and S pole-face are to inclined.And this angle is output corresponding to the resistance value of magnetic field degree of tilt as the magneto-resistance effect element that is provided with in the face of each pole-face.At this moment, the magnetic direction that measures is identical and each magneto-resistance effect element is set, and on the other hand, keeps rightabout magnetic field generation device to keep the opposite polarity of the N utmost point or the S utmost point, thereby obtains rightabout resistance value.And the mode of the difference by calculating these resistance values can measure variable quantity (approximately twice) bigger when a magneto-resistance effect element is set.Its result, the measurement sensitivity that can improve degree of tilt, simultaneously, because of the magnetization fixed-direction of a plurality of magnetic field measuring devices is set in equidirectional, thereby it is simple in structure, and then can realize the miniaturization of sensor.

And, also comprising the bridge circuit of measuring the differential voltage between each magneto-resistance effect element on the said structure, and then each magneto-resistance effect element is faced described N pole-face and S pole-face respectively and respectively is provided with two.

Thus, utilize bridge circuit measured resistance value easily, thereby measure the acceleration on the prescribed direction easily.And, use the acceleration on the direction according to the rules and four magneto-resistance effect elements changing whole resistance values are formed bridge circuit, thereby measure bigger differential voltage, thereby can measure acceleration more accurately by the variation of resistance value.

And four magneto-resistance effect elements are connected side by side and formed bridge circuit in chips, and form voltage apply with terminal and differential voltage measurement terminal on this chip.

Thus, as mentioned above, make whole magneto-resistance effect elements fixing, thereby wafer program (wafer process) can be formed on the chip (chip) by the equidirectional magnetization.Thereby, can realize being used the miniaturization of element, can realize the miniaturization of acceleration transducer self.

The acceleration transducer of other structurally associateds of the present invention, it comprises: a pair of semi-girder, its stiff end is arranged on the same straight line or on the position of almost parallel mutually on the contrary towards free-ended direction, and each free end has can be along the degree of freedom of equidirectional deflection; The pair of magnetic field generation device, N pole-face and S pole-face constitute and are installed in respectively on each free end of each semi-girder towards the equidirectional one; Each magnetic field measuring device, it is provided with at least one in the face of the N pole-face of each magnetic field generation device with the S pole-face respectively separately, and the measurement magnetic direction; Wherein, each magnetic field measuring device is formed by the magneto-resistance effect element that changes resistance value corresponding to magnetic direction respectively, and simultaneously, being provided with by it becomes same direction in the face of magnetic direction that described each magnetic field generation device can measure.

And, as the acceleration measurement device on the length direction of semi-girder, in the face of the N pole-face of the magnetic field generation device of a side and opposite side and S pole-face the group that is made of four described magneto-resistance effect elements at least is set respectively, simultaneously, track as along the deflection semi-girder time forms face and perpendicular to the acceleration measurement device on the direction of the length direction of described semi-girder, is provided with at least by four magneto-resistance effect elements group that constitute, identical with the magneto-resistance effect element group of acceleration measurement device in addition.

According to foregoing invention, at first,, then produce revolving force according to each free-ended moment if on prescribed direction, produce acceleration, thus each overhanging beam of difference deflection.And the magnetic field generation device that is installed on each free end is tilted, along with magnetic direction also changes.At this moment, each free end staggers and by deflection in two direction of principal axis of regulation.At this, in the device of acceleration transducer was installed, the regulation plane that forms this device was set at the X-Y plane that is made of X-axis and Y-axis, and vertical therewith direction dictates is a Z-direction.And, can be when a pair of overhanging beam be set, for the acceleration on the X-direction (perhaps Y direction) to the Z-direction deflection and along X-axis (perhaps Y-axis), this a pair of overhanging beam deflection round about respectively, on the other hand, for the acceleration of Z-direction, this a pair of overhanging beam is to the equidirectional deflection.And,, measure the twisting states of aforesaid a pair of overhanging beam by each magnetic field measuring device, thereby can measure two acceleration on the direction of principal axis as the variation of the magnetic direction of magnetic field generation device.That is, come measured resistance value, thereby can constitute the acceleration transducer of simple in structure, miniaturization and cost degradation by using magneto-resistance effect element.Particularly as mentioned above, the magnetic direction that measures owing to N pole-face and S pole-face corresponding to each magnetic field generation device keeps equidirectional that each magneto-resistance effect element is set, therefore, when can improve the measurement sensitivity of acceleration, because the magnetization fixed-direction of a plurality of magnetic field measuring devices is set at the cause of equidirectional, it is simple in structure.And then because a plurality of magnetic field measuring devices concentrate in together, therefore, as described later, the resistance value deviation between the element of formation bridge circuit is very few, and, the temperature characterisitic of each element is consistent.Its result can suppress the variation of the temperature variation of the bridge circuit that chip of reason constitutes greatly, can improve the temperature drift characteristic.

And, be used to measure all directions acceleration and by each magneto-resistance effect element that each component is arranged, be provided with each bridge circuit of measuring the differential voltage between described each magneto-resistance effect element.At this moment, in a chip, form each magneto-resistance effect element in the face of each each magnetic field generation device, and can on each chip, constitute bridge circuit and form voltage and apply with terminal and differential voltage measurement terminal.And then on each each chip, each magneto-resistance effect element that is formed in each chip has equidirectional.

Thus, though use the magneto-resistance effect element that has been set up corresponding to different magnetic field generation devices to come the acceleration of measured X direction of principal axis and Z-direction,, can measure simply by the mode of bridge circuit measured resistance value at that time.And then, because each magneto-resistance effect element of corresponding each magnetic field generation device can be contained in the chip, therefore, can realize being used the miniaturization of element, thereby can realize the miniaturization of acceleration transducer self.

And, in having the acceleration transducer of described structure, when a pair of semi-girder has degree of freedom on the torsional direction of this beam, can be respectively provided to another torsional direction magnetic field measuring device of the magnetic direction that the twist operation of a few measurement by semi-girder change in the face of the N pole-face of at least one magnetic field generation device and S pole-face, each magnetic field measuring device that torsional direction is used is formed by the magneto-resistance effect element that changes resistance value corresponding to magnetic direction respectively, and the magnetic direction that can measure is set simultaneously becomes same direction.

Thus, when being accelerated on another axle (for example, the Y-axis) direction outside the described diaxon (for example, X-axis and Z axle), semi-girder is changed magnetic direction by magnetic field generation device thus by deflection.And, as mentioned above, when measuring the variation of the relevant magnetic direction of other magnetic field measuring devices, use the N pole-face that corresponds respectively to magnetic field generation device and S pole-face and the magneto-resistance effect element that is provided with, thereby can measure the acceleration on more high-precision another direction of principal axis (for example, Y-axis).

And preferably, as above-mentioned acceleration transducer, it possesses the bridge circuit of measuring the differential voltage between each magneto-resistance effect element that torsional direction uses.And, if each magneto-resistance effect element that torsional direction is used is in the face of with the S pole-face and respectively two separately of the settings of N pole-face, the measurement sensitivity that then further improves acceleration.And then four magneto-resistance effect elements that torsional direction is used are tied together and are formed bridge circuit in chips, and formation voltage applies with terminal and differential voltage measurement terminal on this chip, thereby realize the miniaturization of sensor.

And described a pair of semi-girder is the tabular beam that the track when having perpendicular to this semi-girder deflection forms the plane of face.Like this, by forming tabular beam, thereby, can produce aforesaid deflection easily and reverse for the acceleration on each direction of principal axis.Thus, can form the acceleration transducer that utilizes simple structure to measure the acceleration on three direction of principal axis, thereby can realize miniaturization and cost degradation.

And preferably, described magnetic field generation device is a U font magnet.At this moment, be provided with the ferromagnetism body at opposition side position of the formation face of the N utmost point that covers U font magnet and the S utmost point.And then, in each free end of each overhanging beam, be divided into each magnetic field generation device a plurality of respectively and be provided with.

Thus, by forming the magnetic field generation device of U font, significantly be added to the magnetic field intensity that is mapped to magnetic field measuring device.Particularly by combination U font magnet and ferromagnetism body (iron, permalloy, ferrite etc.), significantly suppress magnetic field and spill phenomenon outside the magnetic field measuring device direction, and can suppress the mutual interference between the adjacent magnets.Its result, even the intensive magnetic field measuring device that is provided with also can obtain high output voltage (magnetic resistance change rate), big magnet needn't be set in order to obtain high-intensity magnetic field or form more microscler shape, and, by cutting apart magnetic field generation device, thereby can realize further miniaturization.Thus, magnetic field measuring device can intensively be set, thereby can realize the miniaturization of sensor, and reduce cost.

The acceleration transducer that the present invention is correlated with, wherein, the support component of the stiff end of the semi-girder that supports at least one side is set, simultaneously, this support component is installed on the fixed part as a part that is fixed on the acceleration transducer on the acceleration analysis object, is provided with between support component and the fixed part and can measures the mutual traverse measuring device that relatively moves.At this, traverse measuring device has measurement according to support component and relatively moving of fixed part and the function of the stress of being energized.Particularly, this traverse measuring device is corresponding to support component and relatively moving of fixed part and the shear stress of being energized and export piezoelectricity (PZT) element of electric signal.And then, the weight with extra fine quality is set on support component.

Thus, at first, when producing acceleration on the acceleration analysis object, the fixed part moment on the acceleration analysis object moves to the acceleration direction, but the reaction of support component is slower.Like this, produce relative displacement between fixed part and the support component, at this moment, utilize the traverse measuring device that is arranged between support component and the fixed part to measure incident mutual dislocation, thereby can measure the acceleration that produces on the dislocation direction.For example, export the sensors such as PZT element of electric signal by using to be energized at the stress (specifically being shear stress) of traverse measuring device, thereby can more promptly measure acceleration according to mutual dislocation.And then, by increasing the quality of support component, further slow down the tracking that the acceleration analysis object relatively moves, thereby can further improve the measurement sensitivity of acceleration.

Also have, above-mentioned acceleration transducer is installed on the electronic installation such as hard disk drive, and measures the acceleration that produces on this electronic installation.Thus, the action of control electronic installation when measuring the regulation acceleration, and can from acceleration, protect this to install self.And then, the impact that puts on electronic installation or inclination of electronic installation etc. can also be measured, and processing can be implemented corresponding to the situation of the electronic installation that is measured to.Thereby, when can constitute the high-reliability electronic device, can realize the high mechanization of electronic installation.Particularly, the rail direction of seeking that the highly sensitive direction of measurement of above-mentioned traverse measuring device is set at the head-slider on the hard disk drive is good, and stop the record regenerating of data when on this direction, measuring acceleration, thereby can suppress record regenerating mistake to the densification disk.

And, because above-mentioned acceleration transducer can measure the acceleration of 1G to about the 50G, therefore, sensor can have function simultaneously by the acceleration analysis free-falling, the function of impacting by acceleration analysis and the function by the acceleration analysis angle.

Acceleration measurement method as another embodiment of the present invention, it is characterized in that, utilize stiff end and free-ended position to keep reverse direction and be arranged on the same straight line or on the position of almost parallel, and each free end has can be along a pair of semi-girder of the degree of freedom of equidirectional deflection, measurement is installed in the magnetic direction from each magnetic field generation device generation on each free end, and based on the acceleration at least two direction of principal axis of its measure of the change.

At this moment, based on the combination of the variation of each magnetic direction that measures from each magnetic field generation device, measure acceleration.Particularly, be equidirectional or rightabout so-called combination based on each magnetic direction that measures from each magnetic field generation device, measure acceleration.

Also have, based on a pair of semi-girder because of reversing the magnetic direction that changes, measure other axial acceleration.

And then, use the magneto-resistance effect element that changes because of the magnetic field input to come the mode of measured resistance value to measure magnetic direction.

This acceleration measurement method also has effect, the effect as above-mentioned acceleration transducer, and it also can realize the purpose of the invention described above.

The present invention has the excellent effect that did not have in the prior art by described structure, according to therewith, use a pair of overhanging beam, measure magnetic direction by the magnetic field generation device that is arranged on the free end, can utilize simple structure to measure acceleration on a plurality of directions thus, thereby obtain small-sized and acceleration transducer cheaply.

Also have, when use has the magnetic field generation device of the N utmost point, the S utmost point, with the acceleration on the direction according to the rules and the N utmost point of the magnetic field generation device that tilts and the magnetic direction of the S utmost point measure with resistance value, and, when a magneto-resistance effect element was set, its difference had bigger variable quantity.Its result, the present invention have the excellent effect that did not have in the prior art, promptly, can improve the measurement sensitivity of acceleration, simultaneously, because of the magnetization fixed-direction of a plurality of magneto-resistance effect elements is set in equidirectional, thereby it is simple in structure, and then can realize the miniaturization of sensor.

Description of drawings

Fig. 1 represents the structure as the overhanging beam of the part of acceleration transducer.Figure 1A is a vertical view, and Figure 1B is a underside perspective view.

Fig. 2 represents the one-piece construction synoptic diagram of acceleration transducer.Fig. 2 A is the exploded view of acceleration transducer, and Fig. 2 B is the side view of simple expression.

Fig. 3 A, Fig. 3 B are the key diagram of the measuring principle of expression acceleration.

Fig. 4 A, Fig. 4 B are the key diagram of the measuring principle of expression acceleration.

Fig. 5 A, Fig. 5 B, Fig. 5 C are the key diagram of the measuring principle of expression acceleration.

Fig. 6 A, Fig. 6 B are the key diagram of the measuring principle of expression acceleration.

Fig. 7 A to Fig. 7 F is the key diagram of the appropriate setting of expression sensor.

Fig. 8 A to Fig. 8 C is the key diagram of the measuring principle of expression acceleration.

Fig. 9 A is the synoptic diagram of the state that is provided with of each sensor of expression, and Fig. 9 B is the structural representation of expression bridge circuit.

Figure 10 is the underside perspective view of expression as the variation of the overhanging beam of the part of acceleration transducer.

Figure 11 represents the structural representation of overhanging beam of the part of the acceleration transducer of being correlated with as second embodiment, and wherein, Figure 11 A is the upside stereographic map, and Figure 11 B is a underside perspective view.

Figure 12 A, Figure 12 B represent that respectively each direction of principal axis on the overhanging beam that second embodiment is correlated with is with the state that is provided with of sensor.

Figure 13 A, Figure 13 B are the key diagram of the measuring principle of expression the 3rd embodiment acceleration of being correlated with, and the occasion of U font magnet is used in its expression.

Figure 14 A, Figure 14 B are the key diagram of the measuring principle of expression the 3rd embodiment acceleration of being correlated with, the relation when U font magnet is used in its expression between the resistance value of magnetic direction and GMR element.

Figure 15 A, Figure 15 B represent what the 3rd embodiment was correlated with, the view when using the GMR element to constitute bridge circuit.

Figure 16 represents the structure of the magnetic-field measurement chip that the 3rd embodiment is correlated with, and represents the relation that is provided with of the relative U font of this magnetic-field measurement chip magnet simultaneously.

Figure 17 A, Figure 17 B represent the synoptic diagram of the bridge circuit that is made of the magnetic-field measurement chip.

Figure 18 A represents the simple structural representation of the magnetic-field measurement chip that the 3rd embodiment is correlated with, and Figure 18 B represents the relation that is provided with of the relative U font of magnetic-field measurement chip magnet.

Figure 19 represents what the 4th embodiment was correlated with, as the structure of the overhanging beam of the part of acceleration transducer.Figure 19 A is a vertical view, and Figure 19 B is a underside perspective view.

Figure 20 represents the one-piece construction synoptic diagram of the acceleration transducer that the 4th embodiment is correlated with.Figure 20 A is the exploded view of acceleration transducer, and Figure 20 B is the side view of simple expression.

Figure 21 A, Figure 21 B are for representing the key diagram of the acceleration analysis principle that the 4th embodiment is correlated with.Figure 22 A, Figure 22 B, Figure 22 C are for representing the key diagram of the acceleration analysis principle that the 4th embodiment is correlated with.

Figure 23 A, Figure 23 B are for representing the key diagram of the acceleration analysis principle that the 4th embodiment is correlated with.

The key diagram of the appropriate setting of the acceleration transducer that Figure 24 A, Figure 24 B, Figure 24 C, Figure 24 D are correlated with for expression the 4th embodiment.

Figure 25 represents what the 4th embodiment was correlated with, to the set-up mode of the magnetic-field measurement chip of U font magnet.

Figure 26 represents what the 4th embodiment was correlated with, to the embodiment that improves of the set-up mode of the magnetic-field measurement chip of U font magnet.

Figure 27 represents the structure of the magnetic-field measurement chip that the 4th embodiment is correlated with, and represents the relation that is provided with of the relative U font of these magnetic-field measurement chips magnet simultaneously.

Figure 28 represents what the 4th embodiment was correlated with, the key diagram when constituting bridge circuit with each magnetic-field measurement chip.

Figure 29 represents what the 4th embodiment was correlated with, to the variation of the set-up mode of the magnetic-field measurement chip of U font magnet.

Figure 30 represents the variation of overhanging beam structure of the part of the acceleration transducer of being correlated with as the 4th embodiment, and wherein, Figure 30 A is the upside stereographic map, and Figure 30 B is a underside perspective view.

Figure 31 A, Figure 31 B represent the variation that the magnetic-field measurement chip constitutes respectively.

Synoptic diagram when Figure 32 A, Figure 32 B represent that relative magnet is provided with magnetic-field measurement chip shown in Figure 31.

View when Figure 33 represents that acceleration transducer of the present invention is installed in hard disk drive.

Figure 34 represents a part of structural representation of the acceleration transducer that the 6th embodiment is correlated with.

Figure 35 represents the side view of the acceleration transducer that the 6th embodiment is correlated with.

Figure 36 represents what the 6th embodiment was correlated with, the view when degree of will speed up sensor is installed in the acceleration analysis object.

Figure 37 represents the variation of the acceleration sensor structure that the 6th embodiment is correlated with.

Embodiment

The invention is characterized in, in the free-ended position of the acceleration on corresponding prescribed direction and a pair of overhanging beam that changes, be installed in the magnetic direction of the magnetic field generation device on this each free end by measurement, thereby measure acceleration.Next, its concrete structure is described in conjunction with the embodiments.

[embodiment 1]

In conjunction with Fig. 1 to Figure 10 the first embodiment of the present invention is described.Fig. 1 to Fig. 2 represents the structure of acceleration transducer.Fig. 3 to Fig. 8 is the key diagram of expression acceleration analysis principle and method.Fig. 9 is the simple synoptic diagram of the structure of expression acceleration transducer.Figure 10 is the relevant synoptic diagram of variation of the structure of expression acceleration transducer.

[structure]

The structure of the acceleration transducer that present embodiment is relevant at first, is described referring to figs. 1 through Fig. 2.Shown in Fig. 2 A, the acceleration transducer that present embodiment is relevant roughly is made of three structures (A, B, C).At first, be arranged on the first structure A on acceleration transducer top in conjunction with Fig. 1 explanation.Figure 1A represents its vertical view, and Figure 1B represents underside perspective view.

As shown in Figure 1, the first structure A comprises the roughly rectangular framework 3 with specific thickness, and wherein, in the central authorities of each minor face, one is equipped with stiff end 11b, the 12b to separately a pair of overhanging beam 1 (each overhanging beam 11,12) that extends to the center.Also have, each beam 11,12 is located along the same line when forming this a pair of overhanging beam 1, and each free end 11a, 12a stand facing each other mutually and be set up.That is, the stiff end of two beams 11,12 and free-ended position keep reverse direction and are set up.

Also have, each beam 11,12 is on the plane that is formed by framework 3, and is parallel substantially roughly tabular and be formed, and has the degree of freedom perpendicular to deflection on the direction on this plane.Specifically, be fulcrum with the tie point of each beam 11,12 and framework 3, free end 11a, 12a can retouch out arc track (deflection track) and deflection on the plane perpendicular to the plane that is formed by framework 3.And each beam 11,12 also has degree of freedom on torsional direction.In addition, the same length of each beam 11,12, it is shorter than half length on the long limit of framework 3.Thus, on the approximate centre position of framework 3, free end 11a, 12a stand facing each other mutually and are set up.

And, on free end 11a, the 12a of the mutual face-off of each beam 11,12, being separately installed with magnet 21,22 (magnetic field generation device), it constitutes pair of magnet 2.The length direction of each magnet 21,22 is approximately perpendicular to the length direction of beam 11,12, and it has roughly rectangular shape.Also have, shown in Figure 1A, it is installed on the following side of free end 11a, 12a, and, make the N utmost point be positioned at its downside, the S utmost point is positioned at its upside (with reference to Fig. 4 A described later).Specifically, do not applying under the state of acceleration, the magnetic direction of magnet 21,22 is the direction that is approximately perpendicular to the plate face of tabular overhanging beam 11,12, promptly, its direction is to form face along 11,12 o'clock track of deflection overhanging beam, perpendicular to the direction of the length direction of this overhanging beam 11,12.In addition, magnet the 21, the 22nd, permanent magnet.

At this, shown in Figure 1A and Fig. 2 A, among the above-mentioned first structure A, the plane parallel that is formed by framework 3 is in the X-Y plane of the electronic installation that is mounted (for example, hard disk drive).And the long edge of framework 3 X-direction, minor face is set up along Y direction.Thereby each overhanging beam 11,12 is along the X-axis setting, and it has the degree of freedom of deflection on Z-direction.And (horizontal direction under) the user mode for example, hard disk drive, that is, this magnetic direction is a Z-direction to the magnetic direction of above-mentioned magnet 21,22 perpendicular to the device that is set up.

Next, be installed on second structure B and the 3rd structure C of the above-mentioned first structure downside in conjunction with Fig. 2 explanation.Fig. 2 A is the one-piece construction synoptic diagram of acceleration transducer, and Fig. 2 B is the integrally-built side sectional drawing of simple expression acceleration transducer.

At first, the 3rd structure C comprises that shape is approximately identical to the pedestal 5 of the roughly rectangular sheet material system of above-mentioned framework 3.And second structure B has the side surface body 6 of specified altitude for surrounding the periphery of the 3rd structure C.This side surface body 6 is arranged between the 3rd structure C and the first structure A, thereby forms the space between these structures A and C.That is, form the space of a pair of overhanging beam 1 of the permission first structure A along the Z-direction deflection.

At this, be elaborated at the 3rd structure C.Pedestal 5 is provided with corresponding to being installed in the above-mentioned pair of magnet 2 on the framework 3 and measures the pair of magnetic field measured chip (magnetic field measuring device) 4 of magnetic direction separately.That is,, magnetic- field measurement chip 41,42 is installed respectively corresponding to each magnet 21,22 on the free end 11a, the 12a that are installed in each beam 11,12 respectively.Shown in Fig. 2 B, the assembling acceleration transducer after, these magnetic-field measurement chips 41,42 be positioned at each magnet 21,22 under.

Specifically, corresponding each magnet 21,22 is separately installed with three above-mentioned magnetic-field measurement chips 41,42.Promptly, shown in Fig. 2 A, comprise: the magnetic-field measurement chip 41x of the acceleration on the measured X direction of principal axis, measure the magnetic-field measurement chip 41y of the acceleration on the Y direction and the magnetic-field measurement chip 41z that measures the acceleration on the Z-direction corresponding to the magnetic-field measurement chip 41 of a side magnet 21.Promptly, shown in Fig. 2 A, comprise: the magnetic-field measurement chip 42x of the acceleration on the measured X direction of principal axis, measure the magnetic-field measurement chip 42y of the acceleration on the Y direction and the magnetic-field measurement chip 42z that measures the acceleration on the Z-direction corresponding to the magnetic-field measurement chip 42 of a side magnet 21.And, the corresponding pair of magnet 21,22 of these magnetic-field measurement chips and be applicable to each direction of principal axis (X-axis with, Y-axis with, Z axle with) and be set up (41x and 42x, 41y and 42y, 41z and 42z), as described later, use the measured value of a pair of associated magnetic field measured chip to measure acceleration on each direction of principal axis.

On the top lamination face on above-mentioned each magnetic-field measurement chip 41,42, be formed with by the MR resistance value of output corresponding to the magnetic direction that is transfused to, thus the GMR element (magneto-resistance effect element) (for example, 41xa, 42xa) of measurement magnetic direction.Be directed to this, the magnetic-field measurement chip shown in the reference marks 41x is elaborated.The GMR element 41xa of described chip 41x is provided with several along direction (Y direction) linearity perpendicular to X-axis, and contacts mutually.And, magnetize for the acceleration on the measured X direction of principal axis and to be fixed on the X-direction.The chip GMR element 42xa of symbol 42x also has same structure.Also have, the GMR element of the magnetic-field measurement chip shown in symbol 41y, the 42y is provided with several along direction (X-direction) linearity perpendicular to Y-axis, and polyphone mutually, and it magnetizes in order to measure the acceleration on the Y direction and is fixed on the Y direction.On the other hand, the GMR element of the chip shown in symbol 41z, the 42z also has the identical structure of using with X-axis of chip 41x, 42x.That is, form several perpendicular to the last linearity of the direction (Y direction) of X-axis, and polyphone, and magnetization is fixed on the X-direction.And, be formed with the splicing ear that is connected above-mentioned GMR element two ends on each magnetic-field measurement chip 41,42.Thus, as described later, can measure magnetic direction with MR resistance value corresponding to magnetic direction.

[measuring method]

Next,, describe to shown in Figure 6 in conjunction with Fig. 3 at measuring principle and the method for measuring the acceleration on each direction of principal axis according to said structure.At first, the input angle of the magnetic field H of relative GMR element is described in conjunction with Fig. 3, with and and the MR resistance value between relation.The top of Fig. 3 A is provided with magnet 21, and still, when not quickening in any direction, magnetic-field measurement chip 4 is approximately perpendicular to the direction (with reference to dot-and-dash line and Fig. 4 A of Fig. 3 A) of the magnetic field H of magnet 21 and is set up.And, as described later, when beam 11,12 along Z-direction, that is, along perpendicular to the X-Y plane deflection that forms by framework 3, then, the magnetic field generation face of magnet 21 is tilted, the direction inclination-Δ θ of consequent magnetic field H (Δ is the mark of expression variable quantity) or+angle that Δ θ is suitable.Like this, shown in the dotted arrows among Fig. 3 A, magnetic field has predetermined angular and is input in the GMR element.At this moment, as mentioned above, because that the GMR element of the lamination face of magnetic-field measurement chip 4 is magnetized along a direction (for example, X-direction) is fixing, therefore, if the magnetic direction on this direction changes, then, shown in Fig. 3 B, the MR resistance value also changes.That is, in this example, the resistance value under the plumbness is set at R0, and it has the characteristic that king-sized variation takes place when being illustrated in the inclination minute angle.Thereby because of each free end 11a, 12a of acceleration deflection semi-girder 11,12, thereby the direction of the magnetic field H of magnet mounted thereto is measured in the variation of MR resistance value that can be by the GMR element.

Below, specify the measuring principle of each axial acceleration.At this, the principle when Fig. 4 to Fig. 5 has illustrated the acceleration of measured X direction of principal axis and Z-direction.As mentioned above, be respectively arranged with pair of magnetic field measured chip 41x, 42x that X-axis is used, and pair of magnetic field measured chip 41z, the 42z of Z axle usefulness, still, the magnetization fixed-direction of MR element separately is X-direction.Thereby, can use identical chip, still, as described later,, therefore, X-axis chip 41x, 42x and Z axle chip 41z, 42z are set respectively in order to constitute bridge circuit and to measure two axial acceleration.

In addition, because that the chip of above-mentioned X-axis and Z axle usefulness only is magnetized on X-direction is fixing, therefore, if, then, can only measure the acceleration of X-direction only with the magnetic direction on semi-girder of a chip measurement.But, as described herein, a pair of beam 11,12 being set respectively, therefore pair of magnet 21,22, and pair of magnetic field measured chip 41,42, as mentioned above, can measure X-direction and Z-direction, that is, and the acceleration on two direction of principal axis.

At first, shown in Fig. 4 A, usually, the direction of the magnetic field H of magnet 21,22 is approximately perpendicular to the lamination face of magnetic-field measurement chip 41,42 and is set.But, shown in Fig. 4 B, be subjected to the influence of the quality of the deadweight of beam 11,12 or magnet 21,22, therefore, usually, free end 11a, the 12a of beam 11,12 are sagging.At this moment, relative vertical direction inclination-Δ θ g separately, therefore, and in the same manner, the also relative vertical direction inclination-Δ θ g of the input angle of GMR element.In addition, owing to each beam 11,12 keeps reverse direction to be set up, therefore, the both forward and reverse directions of this angle is also opposite.And, the figure shows state with acceleration, acceleration on the X-direction of this moment and the acceleration on the Z-direction are to represent with the variable quantity of the direction of magnetic field H, promptly, poor with it by the angle of inclination sum of calculating above-mentioned magnet 21,22, and represent according to the angular dimension that this calculates.Specifically, be the poor of input angle corresponding to the angle A x of the acceleration on the X-direction, be the input angle sum corresponding to the angle A z of the acceleration on the Z-direction, that is, and Ax=-Δ θ g-(Δ θ g)=0, Az=-Δ θ g+ (Δ θ g)=-2 Δ θ g.

Next, shown in Fig. 5 A, the situation during at acceleration on X-direction describes.Shown in Fig. 5 A, when quickening on arrow G x direction, the free end of the beam 11 of a side (magnet 21) is to the positive dirction deflection of Z axle, therefore, and magnet 21 relative vertical direction inclination-Δ θ g+ Δ θ x.And the free end of the beam 12 of opposite side (magnet 22) is to the negative direction deflection of Z axle, therefore, and magnet 22 relative vertical direction inclination-Δ θ g-Δ θ x.At this, be respectively corresponding to the angle A x of the acceleration of X-direction and angle A z corresponding to the acceleration of Z-direction, Ax=(Δ θ g+ Δ θ x)-(Δ θ g-Δ θ x)=+ 2 Δ θ x, Az=(Δ θ g+ Δ θ x)+(Δ θ g-Δ θ x)=-2 Δ θ g.

In the same manner, Fig. 5 B is illustrated in the situation of quickening on the Z-direction.Shown in Fig. 5 B, when quickening on arrow G z direction, the free end of a pair of beam 11,12 (magnet 21,22) is simultaneously to the positive dirction deflection of Z axle, therefore, and magnet 21,22 relative vertical direction inclination-Δ θ g+ Δ θ z.At this, be respectively corresponding to the angle A x of the acceleration of X-direction and angle A z corresponding to the acceleration of Z-direction, Ax=(Δ θ g+ Δ θ z)-(Δ θ g+ Δ θ z)=0, Az=(Δ θ g+ Δ θ z)+(Δ θ g+ Δ θ z)=-2 Δ θ g+2 Δ θ z.

In the same manner, Fig. 5 B is illustrated in the state that is accelerated on X-axis on the X-Z plane and the Z-direction.Shown in Fig. 5 B owing to comprised the acceleration on the X-direction when on arrow G xz direction, being accelerated, therefore, as mentioned above, the free end of a pair of beam 11,12 (magnet 21,22) respectively with different angles to the Z-direction deflection.Therefore, a side magnet 21 relative vertical direction inclination-Δ θ g+ Δ θ x+ Δ θ z, opposite side magnet 22 relative vertical direction inclination-Δ θ g-Δ θ x+ Δ θ z.At this, be respectively corresponding to the angle A x of the acceleration of X-direction and angle A z corresponding to the acceleration of Z-direction, Ax=(Δ θ g+ Δ θ x+ Δ θ z)-(Δ θ g-Δ θ x+ Δ θ z)=+ 2 Δ θ x, Az=(Δ θ g+ Δ θ x+ Δ θ z)+(Δ θ g-Δ θ x+ Δ θ z)=-2 Δ θ g+2 Δ θ z.

As mentioned above, when relative X-direction is quickened, the deflection round about respectively of the free end of a pair of semi-girder 11,12, when relative Z-direction is quickened, each free end is respectively to the equidirectional deflection, therefore, and the combination of the deflection direction of specific each semi-girder 11,12 by the direction of the magnetic field H on the X-direction of measuring each magnet 21,22, thereby, can the measured X direction of principal axis and Z-direction on two axial acceleration.

Fig. 6 is illustrated in the situation when quickening on the Y direction.When being accelerated on Y direction, two beams 11,12 reverse to identical torsional direction.Thereby as shown in Figure 6A, magnet 21,22 all rotates to equidirectional.Then, shown in Fig. 6 B, two magnet 21,22 relative vertical direction inclination+Δ θ y, this angle of inclination Δ θ y can be used as corresponding to the angle A y of the acceleration on the Y direction and is used.

Next, in conjunction with Fig. 7 to Fig. 9 acceleration measurement method and formation on each concrete direction of principal axis are described.At first, shown in Fig. 9 A, each axle is provided with pair of magnetic field measured chip ((41x, 42x), (41y, 42y), (41z, 42z)), and, measure the X-direction of each magnet 21,22, the degree of tilt on the Y direction in order to use these each magnetic-field measurement chips 41,42, therefore, use the bridge circuit shown in the MR resistance value pie graph 9B that each magnetic- field measurement chip 41,42 measures.That is, corresponding each axle and form bridge circuit Sx, Sy, Sz, and, can measure separately differential voltage Vx, Vy, Vz and the differential voltage measurement mechanism is set.And, the variation of measuring the resistance value of each GMR element based on the differential voltage that is output.

At this, the differential voltage measurement mechanism is for calculating the calculation element of each differential voltage Vx, Vy, Vz with following account form.At this, in following calculating formula,, represent its variable quantity (for example, " dRx1 ") with the mode of subsidiary " d " with the resistance value that Rx1, Rx2, Ry1, Ry2, Rz1, the Rz2 shown in Fig. 9 B represents the GMR element of each magnetic-field measurement chip.

Then, Vx=((Rx1+dRx1)/(Rx1+dRx1+Rx2-dRx2)-1/2), Vz=((Rz1+dRz1)/(Rz1+dRz1+Rz2-dRz2)-1/2), Vy=((Ry1+dRy1)/(Ry1+dRy1+Ry2-dRy2)-1/2).

At this moment, be fixed on the X-direction, therefore, be necessary to measure the various combination of the deflection direction of aforesaid a pair of semi-girder 11,12 according to the resistance value of each GMR element output because the GMR element on X-direction and the Z-direction all magnetizes.For this reason, the set-up mode of the pair of magnetic field measured chip on each is as described below.

At first, Fig. 7 A is illustrated in the state that X-direction (direction of arrow to the right) goes up a pair of semi-girder 11,12 when producing acceleration, and Fig. 7 B is illustrated in the state that Z-direction (direction of arrow that makes progress) goes up a pair of semi-girder 11,12 when producing acceleration.Also have, Fig. 7 B～Fig. 7 F represents corresponding to the input angle of the magnetic field H of separately GMR element and the positive and negative relation of resistance value.In these figure, the triangle that illustrates in magnetic- field measurement chip 41x, 42x, 41z, 42z is represented the positive negative direction according to the output resistance of magnetic direction to be measured.In addition, be set up owing to the free end of each semi-girder 11,12 stands facing each other respectively, therefore, originally, the positive and negative relation at the angle of inclination of magnet 21,22 keeps reverse direction and is set (with reference to Fig. 4 etc.).

The resistance value of measuring with the GMR element of X-direction at first is described.Shown in the top of Fig. 7 C, if keep reverse direction the GMR element is set, then, shown in the below of Fig. 7 C, the positive and negative relation of resistance value dR is opposite respectively.On the other hand, shown in the top of Fig. 7 E, if the GMR element is set to equidirectional, then, shown in the below of Fig. 7 E, resistance value dR be on the occasion of.At this moment, in order to measure differential voltage and to calculate two resistance values with bridge circuit, then, in Fig. 7 C, Dx=+dR-(dR)=+ 2dR; In Fig. 7 E, Dx=+dR-(+dR)=0, therefore, pair of magnetic field measured chip 41x, 42x that X-direction is used should be set to the reverse direction shown in Fig. 7 C.

Next the resistance value of measuring with the GMR element of Z-direction is described.Shown in the top of Fig. 7 D, if keep reverse direction the GMR element is set, then, shown in the below of Fig. 7 D, resistance value dR be on the occasion of.On the other hand, shown in the top of Fig. 7 F, if to equidirectional the GMR element is set, then, shown in the below of Fig. 7 F, the positive and negative relation of resistance value dR is opposite respectively.At this moment, in order to measure differential voltage and to calculate two resistance values with bridge circuit, then, in Fig. 7 D, Dx=+dR-(+dR)=0; In Fig. 7 F, Dx=+dR-(dR)=+ 2dR, therefore, pair of magnetic field measured chip 41z, 42z that Z-direction is used should be set to the equidirectional shown in Fig. 7 F.

And then, in conjunction with shown in Figure 8, the resistance value of measuring with the GMR element of Y direction is described.At first, Fig. 8 A is illustrated in the state of a pair of semi-girder 11,12 when producing acceleration on the Y direction, and the state of the magnet 21,22 when in the left side this state being shown is shown in Fig. 8 B.In addition, in this diagram, between each magnet 21,22, be provided with at interval.Also have, Fig. 8 C represents corresponding to the input angle of the magnetic field H of separately GMR element and the positive and negative relation of resistance value.At this moment, magnet 21,22 tilts for shown in Fig. 8 C, and therefore, shown in its middle part, reverse direction is provided with the GMR element, and then, shown in downside, the positive and negative relation of resistance value dR is opposite respectively.At this moment, in order to measure differential voltage and to measure two resistance values with bridge circuit, then, Dy=+dR-(dR)=+ 2dR, therefore, pair of magnetic field measured chip 41y, 42y that Y direction is used should be set to the reverse direction shown in Fig. 8 C.

According to the above description, the direction that will be used for each the magnetic-field measurement chip of each is arranged to respectively shown in Fig. 9 A.Thus, measure differential voltage according to the variation of the resistance value of GMR element by bridge circuit, thereby, can measure the variation of the magnetic direction that the magnet 21,22 from the free end that is installed on a pair of semi-girder 11,12 produces.At this moment, the size of differential voltage is corresponding to the size of resistance value, and, also corresponding to the variation (degree of tilt of vertical direction relatively) of magnetic direction.Thereby, can measure corresponding each the degree of tilt of magnet 21,22, and can measure acceleration on each direction of principal axis based on this degree of tilt.

Also have, as mentioned above, the present invention has the structure that a pair of semi-girder 1 is set and measures the changes of magnetic field that produces on its free end.That is, when the acceleration on the generation prescribed direction, on each free end, produce moment, thus each semi-girder 11,12 of difference deflection.And, by being installed in magnet 21,22 on each free end and the variation magnetic field direction.At this moment, the different directions deflection is pressed in the acceleration on relative X-axis of each free end and the Z axle respectively.For example, the acceleration of the relative X-direction of a pair of semi-girder, deflection in the opposite direction, on the other hand, the acceleration of Z-direction relatively is along the equidirectional deflection.And, as the variation of magnetic direction and the different deflected of a pair of overhanging beam are measured, thereby can measure acceleration on X-direction and the Z-direction with the GMR element.And, and then, the GMR element of the acceleration by installing and measuring Y direction, thus can measure three acceleration on the direction of principal axis by simple structure.Thereby, can constitute small-sized and acceleration transducer cheaply.

Show in the above description, the variation that constitutes bridge circuit and measure the resistance value of each GMR element, and be set at the degree of tilt of each magnet 21,22 on each semi-girder 11,12 based on this measure of the change, final, measure the structure of each axial acceleration, but its structure is not limited to this.That is, also can adopt structure and the method for not using bridge circuit and measuring the resistance value of each GMR element.

Also have, can not use bridge circuit, and measure the different deflection directions along Z-direction of each semi-girder 11,12, thereby the acceleration of measured X direction of principal axis and Z-direction also can by other structures and method.At this moment, also the GMR element of pair of magnetic field measured chip 41z, the 42z of Z axle usefulness can be kept reverse direction and (shown in Fig. 7 D and be provided with) is set.At this moment, for example, directly measure the resistance value of each GMR element, and distinguish to come and measure the positive and negative state of its variable quantity, thereby can use X-axis to use and Z axle usefulness jointly, thus the further simplification on the implementation structure.

And, in the above description, a pair of semi-girder 11,12 is arranged to same linearity, still, also can be arranged to same linearity, but it is also passable to be arranged to roughly flat shape.Like this, also the acceleration on X-axis, the Z-direction relatively plays aforesaid same function.Also have, in the above description, each free end that magnet 21,22 is installed stands facing each other mutually and is set up, and still, embodiment is illustrated as described later, and it is also passable that it is installed on opposition side respectively.

And then, in the above description, show the structure that beam 11,12 is provided with along X-axis, still, it also all can along any direction setting.For example, beam 11,12 is set up along Y direction, and its deflection direction is that Z-direction is also passable.

Also have, the magnet 21,22 that is arranged on the free end of a pair of semi-girder 11,12 not only is confined to above-mentioned shape.For example, the underside perspective view of the first structure A as shown in figure 10, it can have the shape of having been cut apart by the matching part of beam 11,12 (reference marks 21a, 21b, 22a, 22b), and then, also can have other difformities.Thus, the magnetic field that can break away from magnet 21,22 produces face and is provided with, needn't intensive setting in the face of magnet 21,22 and the magnetic-field measurement chip that is provided with, and, can suppress the weight of magnet 21,22 and the increase of cost.

[embodiment 2]

In conjunction with Figure 11 to Figure 12 the second embodiment of the present invention is described.Figure 11 represents to comprise the structural representation of first structure of relevant a pair of semi-girder of present embodiment and magnet, and Figure 11 A represents the upside stereographic map, and Figure 11 B is observed stereographic map from the inboard.Figure 12 represents the synoptic diagram of the magnetic-field measurement chip that be provided with this moment.

As shown in figure 11, a pair of semi-girder 101 that the present invention is correlated with roughly is arranged on the same straight line, and each stiff end of each beam 111,112 stands facing each other and is set up.And, each fixing distolaterally is fixed by a plate-like support member 130.Thereby each free end of each beam 111,112 is positioned at opposition side.Thus, can make leave between each magnet 121,122 that is installed on each free end the distance and be provided with.And then each magnet 121,122 is divided into two and be set up.At this moment, on the free end of each beam 111,112, be extended with the short accessory of length perpendicular to beam 111,112, its both ends are provided with divided each magnet (121a, 121b and 122a, 122b).

As the foregoing description, correspondingly, at the downside of each magnet 121,122, each axle is provided with the pair of magnetic field measured chip relatively.At this moment, each magnetic-field measurement chip is set up corresponding to divided magnet 121,122.Specifically, shown in Figure 12 A, be provided with a side chip 141x that X-axis uses and a side chip 141z of Z axle usefulness at the downside of magnet 121a.And, be provided with a pair of chip 141y, the 142y that Y-axis is used at the downside of magnet 121b.Also have, be provided with the opposite side chip 142x that X-axis uses and the opposite side chip 142z of Z axle usefulness at the downside of magnet 122a.In addition, shown in Figure 12 B, a pair of chip 141y, 142y that Y-axis is used are separately positioned under pair of magnet 121b, the 122b also passable.

Thus, can leave distance and pair of magnet 121,122 is set, when measuring magnetic direction, can suppress the influence of opposite side magnet by chip.Thus, can improve measuring accuracy.Also have, needn't chip intensively be set, therefore, design and manufacturing are simple.And then, needn't use framework shown in Figure 13, and use the support component 130 that is arranged on central authorities to support a pair of semi-girder 101, therefore, save the space of sensor self, and can realize cost degradation.

[embodiment 3]

Next, in conjunction with Figure 13 to Figure 18 the third embodiment of the present invention is described.Figure 13 to Figure 15 represents the measuring principle of the acceleration transducer that present embodiment is relevant.Figure 16 to Figure 18 simply represents a part of structure of acceleration transducer.

Also have, in the present embodiment, particularly use U font magnet, and with the magnetic direction of resistance measurement N pole-face and S pole-face, and try to achieve acceleration, thereby can improve sensitivity from its difference as above-mentioned magnet.Next the measuring principle of the acceleration that present embodiment is relevant and the structure of acceleration transducer are described.

At first, the fundamental measurement principle of the acceleration transducer that present embodiment is relevant is as the foregoing description 1 and embodiment 2, promptly, utilize acceleration analysis chip measurement to be supported on semi-girder 201, the magnetic direction that when producing acceleration, produces in the magnet 202 of change location and state, thereby the measurement of realization acceleration.

In the present embodiment, in order further to improve measuring accuracy, use U font magnet 202 as shown in figure 13.The N pole-face of this U font magnet 202 and S pole-face directed downwards and be installed on the free end of semi-girder 201.Use above-mentioned U font magnet 202, thereby prevent that magnetic field from spilling towards periphery from each pole-face, magnetic direction keeps more perpendicular to the direction of each pole-face, and it has directive property.Thereby, can measure the degree of tilt of magnet 202 accurately, that is, can measure acceleration accurately.In addition, can use non-U font magnet, so long as N pole-face and S pole-face get final product to the magnet that the equidirectional one constitutes.

Also have, for the N pole-face that makes U font magnet 202 and the magnetic direction of S pole-face point to GMR element 231a, the 232a of magnetic-field measurement chip 231,232 more and suppress leakage magnetic field, the opposition side position that covers the formation face of the N pole-face of U font magnet 202 and S pole-face with ferromagnetism body (iron, permalloy, ferrite etc.) is good.That is, on the plate of ferromagnetism body, possess N utmost point portion and S utmost point portion and constitute U font magnet, and it is also passable to form the lid type.As mentioned above,, significantly suppress the phenomenon that magnetic field spills from N pole-face and S pole-face by combination U font magnet and ferromagnetism body (iron, permalloy, ferrite etc.), and, the mutual interference between the adjacent magnets can be suppressed.

Also have, and use U font magnet 202 accordingly, N pole-face and S pole-face directed downwards as shown in Figure 3A, are provided with and possess the magnetic-field measurement chip 231,232 of facing the GMR element of each pole-face respectively.Then, shown in Fig. 3 B, during the acceleration of produce (reference arrow Gz), produce the N pole-face and of the state inclination of S pole-face of face as the magnetic field of magnet 202 from Fig. 3 A.At this moment, because U font magnet 202 is constituted by one, therefore, N pole-face and S pole-face are to roughly the same direction inclination equal angular.The measuring principle of the magnetic direction of this moment is described in conjunction with Figure 14 to Figure 15.

Figure 14 A model utility ground expression U font magnet 202 and the magnetic-field measurement chip 231,232 that is set up in the face of this magnet.At this moment, the GMR element of each magnetic-field measurement chip 231,232 is magnetized fixing respectively to equidirectional, and can measure the magnetic direction of equidirectional.And, as mentioned above, if position shown in the dotted line that U font magnet 202 is tilted among Figure 14 A, then, and the variation of the magnetic direction separately by N pole-face and S pole-face, the resistance value that the GMR element is exported is as shown in Figure 14B.That is, output+dR from face the magnetic-field measurement chip 231 of N pole-face, output-dR from face the magnetic-field measurement chip 232 of S pole-face.And, as described later,, measure acceleration from output by these resistance values.

When measuring acceleration, as mentioned above, at first calculate the difference of the resistance value of exporting respectively from each magnetic-field measurement chip 231,232.Then, its output valve promptly, improves and measures sensitivity greater than the occasion of using a chip to measure.Specifically, shown in Figure 15 A, use GMR element 231a, the 232a of each magnetic-field measurement chip 231,232 to constitute bridge circuit, and calculate the differential voltage (Vout) between this GMR element 231a, the 232a.Thus, differential voltage is " 2dR ", and the degree of tilt of magnet is measured in the sensitivity when it uses a GMR element 231a to double.And, shown in Figure 14 A, this be when at GMR element 231a, 232a to the equidirectional magnetization situation fixedly the time.

At this, measure sensitivity in order further to improve, shown in Figure 15 B,, use the resistance value that is measured to corresponding to the degree of tilt of U font magnet 202 as four resistance values that constitute bridge circuit.That is, two magnetic-field measurement chips 233,234 (GMR element 233a, 234a) are set respectively in the face of the N pole-face of U font magnet 202 and S pole-face.And, use four GMR element 31a, 32a, 33a, 34a to measure resistance value corresponding to magnetic direction.This situation as shown in figure 16.

Expression U font magnet 202 in Figure 16, and one group of magnetic-field measurement chip 230.As shown in figure 16, in the face of the N pole-face of U font magnet 202 and S pole-face two magnetic-field measurement chips 231～234 are set respectively on pole-face separately, as a whole, one group of magnetic-field measurement chip 230 with four GMR elements is set on the magnetic field generation face of a U font magnet 202.At this moment, whole magnetization fixed-directions of one group of magnetic-field measurement chip 230 are equidirectional.This is described in detail in the back.

Use above-mentioned four magnetic-field measurement chips 231～234 to form bridge circuit, then, shown in Figure 17 A, the terminal of each chip 231～234 is connected.And, shown in Figure 17 B, from in the face of the GMR element 231a of the magnetic-field measurement chip 231,233 of N pole-face, resistance value that 233a measures are+dR, from being-dR in the face of the GMR element 232a of the magnetic-field measurement chip 232,234 of S pole-face, resistance value that 234a measures.The differential voltage of utilizing the as above bridge circuit of structure to come position shown in compute sign A, the B, thus can further measure degree of tilt in high sensitivity.

Figure 18 illustrates and constitute one group magnetic-field measurement chip 230 by four magnetic-field measurement chips 231～234 shown in above-mentioned Figure 17 A and constitute the bridge circuit that comprises each connecting wiring, thereby form the example of a magnetic-field measurement chip 204.The reason that can form an aforesaid chip is that aforesaid four GMR element 231a～234a are magnetized and are fixed on equidirectional, and the wafer program of making chip also can form the cause of four GMR elements simultaneously easily.If the magnetic-field measurement chip 204 to a chip of this formation is elaborated, then, shown in Figure 18 A, on a magnetic-field measurement chip 204, be formed with four GMR element 231a～234a, and, also be formed with the wiring and each terminal (voltage applies with terminal 204a, 204b (Vcc, G), differential voltage terminal 204c, 204d (A, B)) that connect these parts.Also have, each terminal and each GMR element 231a～234a are connected in chip respectively.

Shown in Figure 18 B, each GMR element 231a～234a of above-mentioned magnetic-field measurement chip 204 is set up in the face of the N pole-face of U font magnet 202 and S pole-face respectively.Differential voltage under this state is measured differential voltage with terminal 204c, 204d (A, B), thereby, can measure acceleration corresponding to the degree of tilt of magnet 202.

And, can measure the acceleration of a direction of principal axis (for example, vertical direction (Z-direction)) by above-mentioned acceleration transducer.And, when wanting to measure the acceleration on other two direction of principal axis, to be arranged on each by the acceleration transducer that above-mentioned semi-girder 201, magnet 202, magnetic-field measurement chip 204 constitute, thereby can measure acceleration on three direction of principal axis (X, Y, Z-direction).

As mentioned above, go up installation U font magnet 202 at semi-girder 1 (elastomeric element), and the GMR element that stands facing each other in this N pole-face and S pole-face is set, and use the bridge circuit measured resistance value, measure acceleration in high sensitivity thereby can have.Particularly, will make a plurality of GMR elements have identical magnetization fixed-direction and be provided with, and be formed in the chip, thereby can realize the miniaturization of acceleration transducer.

[embodiment 4]

Next, in conjunction with Figure 19 to Figure 32 the fourth embodiment of the present invention is described.Figure 19 to Figure 20 represents the structure of acceleration transducer.Figure 21 to Figure 26 is the key diagram of expression acceleration analysis principle and method.The structure of slightly representing acceleration transducer between Figure 27 to Figure 28.Figure 29 to Figure 32 represents the variation of acceleration sensor structure.

[structure]

The structure of the acceleration transducer that present embodiment is relevant is described with reference to Figure 19 to Figure 20.Shown in Figure 20 A, as first embodiment, the acceleration transducer that present embodiment is relevant roughly is made of three structures (A, B, C).At first, be arranged on the first structure A on acceleration transducer top in conjunction with Figure 19 explanation.Figure 19 A represents its vertical view, and Figure 19 B represents underside perspective view.

As shown in figure 19, the first structure A comprises the roughly rectangular framework 313 with specific thickness, wherein, in the central authorities of each minor face, one is equipped with stiff end 311b, the 312b of a pair of overhanging beam 310 (each overhanging beam 311,312) that extends to center separately.Also have, each beam 311,312 is located along the same line when forming this a pair of overhanging beam 310, and each free end 311a, 312a stand facing each other mutually and be set up.That is, the stiff end of two beams 311,312 and free-ended position keep reverse direction and are set up.

Also have, each beam 311,312 is on the plane that is formed by framework 313, and is parallel substantially roughly tabular and be formed, and has the degree of freedom perpendicular to deflection on the direction on this plane.Specifically, be fulcrum with the tie point of each beam 311,312 and framework 313, free end 311a, 312a can retouch out arc track (deflection track) and deflection on the plane perpendicular to the plane that is formed by framework 313.And each beam 311,312 also has degree of freedom on torsional direction.In addition, the same length of each beam 311,312, it is shorter than half length on the long limit of framework 313.Thus, on the approximate centre position of framework 313, free end 311a, 312a stand facing each other mutually and are set up.

Also have, be separately installed with magnet 321a, 321b, 322a, 322b (magnetic field generation device) about free end 311a, the 312a of the mutual face-off of each beam 311,312.In addition, though on each beam 311,312, be separately installed with two magnet,, also a magnet can be installed on each beam 311,312, also pair of magnet can be installed corresponding to a pair of semi-girder 310.

Each magnet 321a, 321b, 322a, 322b are the U font magnet that has thickness on the length direction of beam 311,312.And, the N pole-face of these U font magnet 321a, 321b, 322a, 322b and pole-face directed downwards and be mounted (with reference to Figure 21 A described later).Specifically, do not applying under the state of acceleration, the magnetic direction of U font magnet 321a, 321b, 322a, 322b is the direction that is approximately perpendicular to the plate face of tabular overhanging beam 311,312, promptly, its direction is to form face along 311,312 o'clock track of deflection overhanging beam, perpendicular to the direction of the length direction of this overhanging beam 311,312.Wherein, on the N pole-face, its magnetic direction is for exporting directed downwards from the N pole-face, and on the S pole-face, its magnetic direction is for being input to S pole-face points upwards.In addition, U font magnet 321a, 321b, 322a, 322b are permanent magnet.

At this moment, as mentioned above, on the plate of ferromagnetism body, possess N utmost point portion and S utmost point portion and constitute U font magnet, and form the lid type, thereby, spilling can be suppressed significantly from the magnetic field of N pole-face and S pole-face, therefore, as shown in the figure, magnet is set even adjoin each other, also can suppresses interference such as adhesive or repulsion.

At this, shown in Figure 19 A and Figure 20 A, among the above-mentioned first structure A, the plane parallel that is formed by framework 313 is in a plane (for example, surface level) of the electronic installation that is mounted (for example, hard disk drive).And the long edge of framework 313 X-direction, minor face is set up along Y direction.Thereby each overhanging beam 311,312 is along the X-axis setting, and it has the degree of freedom of deflection on Z-direction.And when the device that is equipped with acceleration transducer (for example, hard disk drive) when being placed on the surface level, the magnetic direction of above-mentioned magnet 321a, 321b, 322a, 322b is the Z-direction perpendicular to this horizontal direction.But the regulation of acceleration transducer is provided with corresponding direction can be any direction.

Next, be installed on second structure B and the 3rd structure C of the above-mentioned first structure downside in conjunction with Figure 20 explanation.Figure 20 A is the one-piece construction synoptic diagram of acceleration transducer, and Figure 20 B is the integrally-built side sectional view of simple expression acceleration transducer.

At first, the 3rd structure C comprises that shape is approximately identical to the pedestal 315 of the roughly rectangular sheet material system of above-mentioned framework 313.And second structure B has the side surface body 314 of specified altitude for surrounding the periphery of the 3rd structure C.This side surface body 314 is arranged between the 3rd structure C and the first structure A, thereby forms the space between these structures A and C.That is, form the space of a pair of overhanging beam 310 of the permission first structure A along the Z-direction deflection.

At this, be elaborated at the 3rd structure C.On pedestal 315, the magnetic-field measurement chip 305,306,307 (magnetic field measuring device) of measuring each magnetic direction is set corresponding to being installed in three magnet among above-mentioned magnet 321a on the framework 313,321b, 322a, the 322b.Its set-up mode shown in Figure 20 B, that is, and the assembling acceleration transducer after, its be positioned at each magnet 321a, 322a, 322b under.And, for the magnetic direction (reference arrow) of the N pole-face of each magnet 321a, 322a, 322b and S pole-face and be used.

The structure of magnetic-field measurement chip 305,306,307 is approximately identical to magnetic-field measurement chip 204 illustrated, that be formed four GMR elements among above-mentioned the 3rd embodiment.At this, magnetic-field measurement chip shown in the symbol 307 is measured the acceleration on the Y direction, the acceleration on two magnetic-field measurement chip measured X direction of principal axis shown in the symbol 305,306 and the Z-direction.That is, two magnetic-field measurement chips shown in the symbol 305,306 partner corresponding to a pair of semi-girder 311,312 and are set up.

As mentioned above, on each lamination face above the magnetic-field measurement chip 305,306,307, respectively form four GMR element (magneto-resistance effect element) output respectively corresponding to the MR resistance value of the magnetic direction that is transfused to.These GMR elements are magnetized fixing in order only to measure the magnetic field on the prescribed direction along prescribed direction.For example, be formed on the magnetic-field measurement chip that the X-direction shown in the symbol 305,306 uses with, Z-direction the GMR element along perpendicular to the direction (Y direction) of X-axis the formation of linearity ground several, and mutual polyphone, and be magnetized for the acceleration on the measured X direction of principal axis and be fixed on the X-direction.In addition, in the back in detail the principle of utilizing the acceleration on these parts measured X direction of principal axis and the Z-direction is described in detail.The GMR element of the magnetic-field measurement chip shown in the symbol 307 is provided with several along direction (X-direction) linearity perpendicular to Y-axis, and mutual polyphone, and it magnetizes in order to measure the acceleration on the Y direction and is fixed on the Y direction.

Be formed with the wiring that connects above-mentioned each GMR element on each magnetic-field measurement chip 305,306,307, and then, be formed with the splicing ear that is connected on these GMR elements (voltage terminal, ground terminal, differential voltage measure with terminal etc.).

Below, specify the measuring principle of each axial acceleration.At this, the principle when Figure 21 to Figure 23 has illustrated the acceleration of measured X direction of principal axis and Z-direction.As mentioned above, use and Z axle usefulness as X-axis, pair of magnetic field measured chip 305,306 is set, the magnetization fixed-direction of its GMR element separately is X-direction.And, as described later, be formed among four GMR elements on the magnetic-field measurement chip, two are the X-axis element, remain two and are Z axle element.Thereby, among pair of magnetic field measured chip 305,306, use two respectively, amount to four GMR elements and constitute bridge circuit, thereby measure two acceleration on the direction of principal axis.Next, further describe measuring principle.

At first, shown in Figure 21 A, usually, the direction of the magnetic field H of magnet 321a, 321b, 322a, 322b is approximately perpendicular to the lamination face of magnetic-field measurement chip 305,306,307 and is set.But, shown in Figure 21 B, be subjected to the influence of the quality of the deadweight of beam 311,312 or magnet 321a, 321b, 322a, 322b, therefore, usually, free end 311a, the 312a of beam 311,312 are sagging.At this moment, relative vertical direction inclination-Δ θ g separately, therefore, and in the same manner, the also relative vertical direction inclination-Δ θ g of the magnetic direction of relative GMR element.In addition, owing to each beam 311,312 keeps reverse direction to be set up, therefore, the both forward and reverse directions of this angle is also opposite.And, the figure shows state with acceleration, acceleration on the X-direction of this moment and the acceleration on the Z-direction are to represent with the variable quantity of the direction of magnetic field H, promptly, poor with it by the angle of inclination sum of calculating above-mentioned magnet 321a, 321b, 322a, 322b, and represent according to the angular dimension that this calculates.Specifically, be the poor of input angle corresponding to the angle A x of the acceleration on the X-direction, be the input angle sum corresponding to the angle A z of the acceleration on the Z-direction, that is, and Ax=-Δ θ g-(Δ θ g)=0, Az=-Δ θ g+ (Δ θ g)=-2 Δ θ g.

Next, shown in Figure 22 A, the situation during at acceleration on X-direction describes.Shown in Fig. 5 A, when quickening on arrow G x direction, the free end of the beam 11 of a side (magnet 321a) is to the positive dirction deflection of Z axle, therefore, and the relative vertical direction inclination-Δ of magnet 321a θ g+ Δ θ x.And the free end of the beam 312 of opposite side (magnet 322a) is to the negative direction deflection of Z axle, therefore, and the relative vertical direction inclination-Δ of magnet 322a θ g-Δ θ x.At this, be respectively corresponding to the angle A x of the acceleration of X-direction and angle A z corresponding to the acceleration of Z-direction, Ax=(Δ θ g+ Δ θ x)-(Δ θ g-Δ θ x)=+ 2 Δ θ x, Az=(Δ θ g+ Δ θ x)+(Δ θ g-Δ θ x)=-2 Δ θ g.

In the same manner, Figure 22 B is illustrated in the situation of quickening on the Z-direction.Shown in Fig. 5 B, when quickening on arrow G z direction, the free end of a pair of beam 311,312 ( magnet 321a, 322a) is simultaneously to the positive dirction deflection of Z axle, therefore, and the relative vertical direction inclination-Δ of magnet 321a, 322a θ g+ Δ θ z.At this, be respectively corresponding to the angle A x of the acceleration of X-direction and angle A z corresponding to the acceleration of Z-direction, Ax=(Δ θ g+ Δ θ z)-(Δ θ g+ Δ θ z)=0, Az=(Δ θ g+ Δ θ z)+(Δ θ g+ Δ θ z)=-2 Δ θ g+2 Δ θ z.

That is, Figure 22 C is illustrated in the state that is accelerated on X-axis on the X-Z plane and the Z-direction.As shown in the drawing owing to comprised the acceleration on the X-direction when on arrow G xz direction, being accelerated, therefore, as mentioned above, the free end of a pair of beam 311,312 ( magnet 321a, 322a) respectively with different angles to the Z-direction deflection.Therefore, a side magnet 321 relative vertical direction inclination-Δ θ g+ Δ θ x+ Δ θ z, opposite side magnet 322 relative vertical direction inclination-Δ θ g-Δ θ x+ Δ θ z.At this, be respectively corresponding to the angle A x of the acceleration of X-direction and angle A z corresponding to the acceleration of Z-direction, Ax=(Δ θ g+ Δ θ x+ Δ θ z)-(Δ θ g-Δ θ x+ Δ θ z)=+ 2 Δ θ x, Az=(Δ θ g+ Δ θ x+ Δ θ z)+(Δ θ g-Δ θ x+ Δ θ z)=-2 Δ θ g+2 Δ θ z.

As mentioned above, when relative X-direction is quickened, the deflection round about respectively of the free end of a pair of semi-girder 311,312, when relative Z-direction is quickened, each free end is respectively to the equidirectional deflection, therefore, and the combination of the deflection direction of specific each semi-girder 311,312 by the direction of the magnetic field H on the X-direction of measuring each magnet 321a, 322a, thereby, can the measured X direction of principal axis and Z-direction on two axial acceleration.

Figure 23 is illustrated in the situation when quickening on the Y direction.When being accelerated on Y direction, two beams 311,312 reverse to identical torsional direction.Thereby both sides magnet 321a, 321b, 322a, 322b all rotate along equidirectional.For this reason, magnet 321a, 321b, the relative vertical direction inclination+Δ of 322a, 322b θ y.Thereby, can be with the angle+Δ θ y of this inclination as corresponding to the angle A y of the acceleration of Y direction and use.

At this, because all magnetizing, the GMR element on X-direction and the Z-direction is fixed on the X-direction, therefore, be necessary to come the various combination of the deflection direction of specific aforesaid a pair of semi-girder 311,312 according to the resistance value of each GMR element output.For this reason, set GMR element in the pair of magnetic field measured chip 305,306 on each as follows.

At first, Figure 24 A is illustrated in the state that X-direction (direction of arrow to the right) goes up a pair of semi-girder 311,312 when producing acceleration, and Figure 24 B is illustrated in the state that Z-direction (direction of arrow that makes progress) goes up a pair of semi-girder 311,312 when producing acceleration.And Figure 24 C, Figure 24 D correspond respectively to above-mentioned Figure 24 A, Figure 24 B, the input angle of the magnetic field H of relative each the GMR element of its expression and the positive and negative relation of resistance value.In these figure, the triangle that illustrates in magnetic-field measurement chip 305,306 is represented the positive negative direction according to the output resistance of magnetic direction to be measured.In addition, be set up owing to the free end of each semi-girder 311,312 stands facing each other respectively, therefore, originally, the positive and negative relation at the angle of inclination of magnet 321a, 322a keeps reverse direction and is set (with reference to Figure 21 etc.).

The resistance value (state shown in Figure 24 A) of the GMR element measurement that the use X-axis is used at first is described.Shown in the top of Figure 24 C, be arranged to the GMR element of right magnetic-field measurement chip 305,306 in the opposite direction, then, shown in the bottom of Figure 24 C, the positive and negative relation of resistance value dR is opposite respectively.On the other hand, in contrast, the GMR element is set along equidirectional, then, resistance value dR be respectively on the occasion of or negative value.At this moment, in order to measure differential voltage and to calculate two resistance values with bridge circuit, then, when direction is opposite, Dx=+dR-(dR)=+ 2dR; When direction is identical, Dx=+dR-(+dR)=0, therefore, the GMR element in the pair of magnetic field measured chip 305,306 that X-direction is used should be set to the reverse direction shown in Figure 24 C.

Next the resistance value (state shown in Figure 24 B) that the GMR element of Z axle usefulness is measured is used in explanation.Shown in the top of Figure 24 D, be arranged to the GMR element of right magnetic-field measurement chip 305,306 along equidirectional, then, the positive and negative relation of resistance value dR is opposite respectively.On the other hand, in contrast, the GMR element is set in the opposite direction, then, resistance value dR be respectively on the occasion of.At this moment, in order to measure differential voltage and to calculate two resistance values with bridge circuit, then, when direction is identical, Dz=+dR-(dR)=+ 2dR; When direction is opposite, Dz=+dR-(+dR)=0, therefore, the GMR element in the pair of magnetic field measured chip 305,306 that Z-direction is used should be set to the equidirectional shown in Figure 24 D.

And then the resistance value of the GMR element measurement of explanation use Y direction, it is identical with above-mentioned the 3rd embodiment.Thereby, make whole GMR elements point to equidirectionals and be provided with and get final product.

Next, to shown in Figure 27, further specify the method to set up of magnetic-field measurement chip 305,306,307 in conjunction with Figure 25.At first, as mentioned above, each magnetic-field measurement chip 305,306,307 is set in the face of each magnet 321a, 322a, 322b.At this moment, as shown in figure 25, in the face of magnet 321a's, two GMR elements in the magnetic-field measurement chip 305 are used with element (symbol SX1) as X-axis, in the same manner, in the face of magnet 322a, two GMR elements in the magnetic-field measurement chip 306 are used with element (symbol SX2) as X-axis, constitute X-axis acceleration transducer SX thus.And, therewith in the same manner, by residue GMR element (SZ1, SZ2) the formation Z axle acceleration transducer SZ of magnetic-field measurement chip 305,306.In addition, as mentioned above, the formation X-axis is set in magnetic-field measurement chip 305,306 in the opposite direction with the GMR element of sensor SX, but, if like this, in magnetic-field measurement chip 306, the magnetization fixed-direction of whole GMR element can not keep equidirectional.Then, can not realize a chipization, therefore, shown in symbol SZ2, SX2 among Figure 26, be necessary to be set at equidirectional.Corresponding to this, the voltage that is connected in these GMR elements applies with the set-up mode of terminal in contrast to common mode to well.This is described in detail in the back.

And four GMR elements in the magnetic-field measurement chip 307 that has been set up in the face of magnet 322b are used with sensor SY as Y-axis.At this moment, its direction is pointed to the torsional direction of beam 312.

Next, the structure and the method to set up thereof of the magnetic-field measurement chip of in fact installing 305,306,307 are described in conjunction with Figure 27.At first, the chip that the structure of the magnetic-field measurement chip 307 that Y-axis is used is correlated with as above-mentioned the 3rd embodiment that has illustrated in conjunction with Figure 18, it is made of identical four the GMR elements 371,372,373,374 of magnetization fixed-direction.And each GMR element 371～374 is faced N pole-face and the S pole-face of magnet 322b respectively.Also have, on this magnetic-field measurement chip, be formed with voltage and apply, thereby form bridge circuit with terminal (Vcc, G) and differential voltage measurement terminal (Y1, Y2).Thus, as mentioned above, measure with the differential voltage between the terminal (Y1, Y2) by measuring differential voltage, thereby can have the degree of tilt of measuring magnet 322b in high sensitivity, that is, and the acceleration on the Y direction.

And, as X-axis use with the Z axle with also being formed with four GMR elements (351,352,353,354) (361,362,363,364) in the same manner respectively on the pair of magnetic field measured chip 305,306 that is used with identical magnetization fixed-direction.But wherein, two GMR elements of the difference in each chip 305,306 constitute X-axis sensor SX1, SX2 (351,352,363,364), Z axle sensor SZ1, SZ2 (353,354,361,362).In addition, about the sensor that X-axis is used, the voltage of the GMR element SX2 in the magnetic-field measurement chip 306 applies with terminal and is connected by reverse direction, thereby output resistance is opposite, and it has the effect of relative SX1 counter-rotating.And, constitute bridge circuit by each with sensor, and measure differential voltage and measure the differential voltage of using between the terminal (X1, X2) (Z1, Z2), thereby measure the degree of tilt of each magnet 321a, 322a, as mentioned above, can measure the acceleration of X-axis or Z week on the direction.That is,, use each GMR element formation bridge circuit as shown in figure 28 of each magnetic-field measurement chip 305,306,307 by said structure.Thereby,, and, that is, measure the acceleration on each direction of principal axis based on the variation that these values are measured the resistance value of each GMR element with described bridge circuit measurement differential voltage Vx, Vy, Vz separately.

And, as shown in figure 27, in each chip, all be magnetized fixingly along equidirectional owing to be formed on GMR element on the magnetic-field measurement chip 305,306,307, therefore, in the wafer program of making chip, can be contained in easily in the chip and make.Thereby, can realize the miniaturization of magnetic-field measurement chip.And each four GMR element is formed in the chip, therefore, can connect these wirings easily when constituting bridge circuit, can simply use.

In addition, in the above description, the N utmost point of U font magnet 321a etc. and the S utmost point are parallel to the length direction of each beam 311,312 and are mounted, and are provided with the GMR element of magnetic-field measurement chip 305,306,307 therewith accordingly, still, are not limited thereto.As shown in figure 29, the N utmost point and the S utmost point of U font magnet 321a etc. are mounted also passable perpendicular to the length direction of each beam 311,312.At this moment, the corresponding N utmost point and the S utmost point and the GMR element of magnetic-field measurement chip 305,306,307 is installed.

Also have, show in the above description, the variation that constitutes bridge circuit and measure the resistance value of each GMR element, and be set at each magnet 321a, the 321b on each semi-girder 311,312, the degree of tilt of 322a, 322b based on this measure of the change, finally, measure the structure of each axial acceleration, but its structure is not limited to this.That is, also can adopt structure and the method for not using bridge circuit and measuring the resistance value of each GMR element.

Also have, can not use bridge circuit, and measure the different deflection directions along Z-direction of each semi-girder 311,312, thereby the acceleration of measured X direction of principal axis and Z-direction also can by other structures and method.For example, directly measure the resistance value of each GMR element, and distinguish to come and measure the positive and negative state of its variable quantity, thereby can use X-axis to use and Z axle usefulness jointly, thus the further simplification on the implementation structure.

And, in the above description, a pair of semi-girder 311,312 is arranged to same linearity, still, also can be arranged to same linearity, but it is also passable to be arranged to roughly flat shape.Like this, also the acceleration on X-axis, the Z-direction relatively plays aforesaid same function.Also have, in the above description, each free end that magnet is installed stands facing each other mutually and is set up, and still, illustrated as the back, it is also passable that it is installed on opposition side respectively.

And then, in the above description, show the structure that beam 311,312 is provided with along the X-axis that forms surface level, still, it also all can along any direction setting.For example, beam 311,312 is provided with along the Y direction that forms surface level, and its deflection direction is that Z-direction is also passable.

At this, Figure 30 represents above-mentioned a pair of semi-girder 310, that is, and and the variation of the first structure A.Figure 30 represents to comprise the structural representation of first structure of relevant a pair of semi-girder of present embodiment and magnet, and Figure 30 A represents the upside stereographic map, and Figure 30 B is observed stereographic map from the inboard.

As shown in figure 30, a pair of semi-girder 401 that the present invention is correlated with roughly is arranged on the same straight line, and each stiff end of each beam 411,412 stands facing each other and is set up.And, each fixing distolaterally is fixed by a plate-like support member 430.Thereby each free end of each beam 411,412 is positioned at opposition side.Thus, can make between each magnet 421,422 that is installed on each free end and be provided with distance.And then each magnet 421,422 is divided into two and be set up.At this moment, on the free end of each beam 411,412, be extended with the short accessory of length perpendicular to beam 411,412, its both ends are provided with divided each U font magnet (421a, 421b and 422a, 422b).

Corresponding to this, as mentioned above, the downside of each U font magnet 421a, 421b, 422a, 422b is provided with the magnetic-field measurement chip.

Thus, be installed in and leave distance between the magnet on each beam 411,412 and be set up, when measuring magnetic direction, can suppress the influence of opposite side magnet by chip.Thus, can improve measuring accuracy.Also have,, therefore, save the shared space of sensor self, and can realize cost degradation owing to use the support component 430 that is arranged on central authorities to support a pair of semi-girder 401.

At this, in conjunction with Figure 31 to Figure 32 the variation of above-mentioned magnetic-field measurement chip is described, and the variation of the method to set up of magnet relatively.Figure 31 A represents the structure of the magnetic-field measurement chip 405 ' (406 ') that X-axis and Z-direction are used.And Figure 31 B represents the structure of the magnetic-field measurement chip 407 ' that Y direction is used.In this diagram, the GMR element is represented at the position shown in symbol 405a (406a) or the symbol 407a.Wherein, each GMR element is magnetized fixing along direction shown in the triangle, and as mentioned above, it all is magnetized fixing in same chip along equidirectional.

State when Figure 32 represents in fact to be provided with in the face of magnet.Figure 32 A is a vertical view, and Figure 32 B is the side view on the direction of arrow shown in Figure 32 A.In this diagram, be separately installed with U font magnet 421a, 421b, 422a, 422b on the semi-girder 401 shown in Figure 30, at this moment, the relative magnet 421a of magnet 421b, 422b, 422a revolve and turn 90 degrees and be mounted.And, be provided with the magnetic-field measurement chip 405 ', 406 ' of above-mentioned X-axis and Z axle usefulness in the face of magnet 421a, 422a, be provided with the magnetic-field measurement chip 407 ' that Y-axis is used in the face of magnet 422b, and each GMR element 405a, 406a, 407a relatively.In addition, be not provided with the chip of relative magnet 421b, but, be mounted magnet yet in order to keep the balance of semi-girder.

As mentioned above, by constituting the magnetic-field measurement chip and U font magnet be set, thereby, as above-mentioned, can measure three acceleration on the direction of principal axis.In addition, the method to set up of the structure of above-mentioned magnetic-field measurement chip and U font magnet, and then the position relation between magnetic-field measurement chip and the U font magnet is not limited to above-mentioned example.

[embodiment 5]

Next illustrate about the example of the acceleration transducer of structure shown in above-mentioned first embodiment to the, four embodiment is installed.For example, degree of will speed up sensor is assemblied in the framework of hard disk drive.

At this, Figure 33 represents the inner structure synoptic diagram of hard disk drive 500.The inside of hard disk drive 500 is equipped with the control basal plate 501 of the work of this driver of control, and on this substrate 501 acceleration transducer 510 is installed.And, the signal that utilizes calculation element (figure does not show) computing on the control basal plate 501 to measure, and the acceleration on the measurement prescribed direction from this sensor 510.Thus,, also can measure the acceleration on aforesaid three direction of principal axis, therefore, can measure the acceleration on any direction rightly no matter how hard disk drive 500 is installed on the computer.

And for example, when a kind of acceleration that measures on each direction of principal axis more than the setting was installed on the hard disk drive 500, it was good will making the mechanism and the control device of the action that magnetic head removes on the disk.Thus, can control the record regenerating of the impaired and track mistake of relative data, thereby can improve reliability.

In addition, in the above description illustration degree of will speed up sensor be installed in situation on the hard disk drive, still, also can be equipped on other electronic equipments.And, when being arranged to measure the regulation acceleration action of control electronic installation and from acceleration the structure of protection this device self.And then, measure acceleration by using above-mentioned acceleration transducer, thereby can measure the impact that puts on the electronic installation or the degree of tilt of electronic installation etc.And, can implement corresponding to the acceleration that measures, that is, and corresponding to the predetermined processing of impact or tilt condition.Thereby, when can constitute the high-reliability electronic device, can realize the high mechanization of electronic installation.

At this, for example, when measuring free-falling, use measurement range at the sensor of 1G～3G for well, when measure impacting, use measurement range at the sensor of 30G～50G for well, but, acceleration transducer of the present invention can measure the acceleration of 1G to about the 50G, function that therefore, sensor can have function by the acceleration analysis free-falling simultaneously, impact by acceleration analysis and the function by the acceleration analysis angle.

[embodiment 6]

Next, in conjunction with Figure 34 to Figure 37 the sixth embodiment of the present invention is described.Figure 34 to Figure 36 represents the structure of the acceleration transducer that present embodiment is relevant, and Figure 37 represents its variation.

In the present embodiment, at first, has a pair of semi-girder and magnet first structure A employing structure as shown in figure 34.Promptly, its structure is approximately identical to the structure shown in Figure 30 B, it comprises: by a pair of semi-girder 511,512, support the plate-like support member 530 of its stiff end, and be arranged on the cantilever part 500 that the magnet installation portion 520 on the free end of a pair of semi-girder 511,512 constitutes; Be installed in four magnet 521a, 521b, 522a, 522b on each magnet installation portion 520 with the N utmost point and S utmost point.But the magnetic field of each magnet 521a etc. sees through magnetic field installation portion 520, and points to downside shown in Figure 34 and be set.Thereby the downside of magnetic field installation portion 520 shown in Figure 34 is provided with the magnetic-field measurement chip that possesses the GMR element.

And, the acceleration determination object thing of the relative hard disk drive of the above-mentioned first structure A etc., its mounting means is as shown in figure 35.That is, the downside of support component 530 is provided with the PZT550 (piezoelectric part) that roughly is rectangular shape, and support component 530 is installed on the substrate 600 that constitutes acceleration transducer by this PZT550.At this moment, the upper surface of PZT550 and lower surface are separately fixed on support component 530 and the substrate 600.And substrate 600 is fixed on the acceleration determination object thing that is called hard disk drive.

And, under the state of Figure 35, Figure 36,, therefore, be formed with this highly suitable gap (with reference to the symbol D among Figure 35) between substrate 600 and the cantilever part 500 (magnet installation portion 520) because PZT550 has specified altitude.In this clearance D, magnet installation portion 520, that is, the downside that is installed on magnet 521a on this magnet installation portion 520 etc. is provided with the magnetic-field measurement chip 610,620 that carries the GMR element.Thus, can use the GMR element to measure the N utmost point of magnet 521a etc., the variation that S extremely goes up the magnetic direction (with reference to the arrow of Figure 35) that produces, and as above-mentioned embodiment illustrated, can measure three acceleration on the direction of principal axis.

And then in the present embodiment, the PZT550 that is arranged between support component 530 and the substrate 600 is if alongst have shear stress, then, to produce voltage according to piezoelectric effect and be set.In order to measure this electric signal (that is, voltage), the two ends on the length direction of PZT550 are provided with electrode, and utilize mode such as welding to be connected on the connecting terminal that is formed on the substrate 600, and then, be connected on the metering circuit.In addition, metering circuit is can measure the acceleration that produces on the length direction of support component 530 corresponding to the magnitude of voltage that measures and work.

And,, when in fact above-mentioned acceleration transducer is installed on the acceleration analysis object that is called hard disk drive, substrate 600 grades are fixedly mounted on the hard disk drive as the 5th embodiment.At this moment, as shown in figure 36, what the direction of principal axis alongst (direction of arrow) of support component 530 was set at head-slider seeks the rail direction.In addition, symbol 650 expression magnetic masks.

And, seeking on the rail direction, promptly of hard disk drive, when producing acceleration on the length direction of support component 530, the substrate 600 that is fixed on this hard disk drive axially moves, still, support component 530 is slower than moving of substrate 600, that is, it is followed substrate 600 and moves.Then, produce between substrate 600 and the support component 530 and relatively move, its position relation produces skew.That is, the top and following side of PZT550 relatively moves, and thus, PZT550 has shear stress in the longitudinal direction.And the shape of PZT550 changes because of this shear stress and produces voltage, and measures this voltage by metering circuit etc., thereby can measure the acceleration on the length direction of support component 530.In addition, the resonant frequency height of PZT550, and sensitivity is also high, therefore, can measure the acceleration of the direction of principal axis alongst (direction of arrow of Figure 36) of support component 530 very at high speed.

At this, for the measuring accuracy of the acceleration alongst that improves support component 530, as shown in figure 37, being provided with on support component 530 to increase these support component 530 quality, and the weight 560 with definite quality is for well.Thus, support component 530 has the strong inertial force that keeps stationary state, and therefore, the trailing phenomenon of the shift action of hard disk drive is slower relatively, thereby the sensitivity of measuring acceleration is higher.

As mentioned above, according to present embodiment, constitute by the first structure A and the magnetic-field measurement chip 610 that possess cantilever part 500 and magnet 521a etc., and possesses first acceleration transducer (acceleration measurement device) of measuring the acceleration on three direction of principal axis, and be higher than second acceleration transducer (other acceleration measurement devices) that the PZT550 of this first acceleration transducer constitutes by resonant frequency, thereby when can measure the acceleration on any direction, can measure the acceleration on the important directions very at high speed.

Utilize possibility on the industry

The acceleration transducer that the present invention is correlated with can be arranged on industrial robot or hard disk drive etc. and be afraid of punching On the machine that hits, and the safety operation such as quit work when measuring the regulation acceleration, thereby can suppress Device is by damaged phenomenon. Therefore, it has the possibility of utilizing on the industry.

Claims (42)

1. acceleration transducer is characterized in that comprising:

A pair of semi-girder, its stiff end is arranged on the same straight line or on the position of almost parallel, described each free end has can be along the degree of freedom of equidirectional deflection towards free-ended direction mutually on the contrary;

The pair of magnetic field generation device, it is installed in respectively on described each free end, and produces magnetic field;

The pair of magnetic field measurement mechanism, it is established in the face of described each magnetic field generation device respectively, and measures the magnetic direction of described each magnetic field generation device.

2. acceleration transducer as claimed in claim 1, it is characterized in that, described each magnetic field measuring device comprises a pair of measurement mechanism respectively, promptly, measure the measurement mechanism of the acceleration on the length direction of described semi-girder, and the track when measuring along the described semi-girder of deflection forms face and perpendicular to the measurement mechanism of the acceleration on the direction of the length direction of described semi-girder.

3. acceleration transducer as claimed in claim 2 is characterized in that, track when the magnetic direction of described magnetic field generation device is set at along the described semi-girder of deflection forms face and perpendicular to the direction of the length direction of described semi-girder.

4. acceleration transducer as claimed in claim 1, it is characterized in that, described a pair of semi-girder has degree of freedom on the torsional direction of this beam, another magnetic field measuring device of the magnetic direction that measurement changes because of the twist operation of semi-girder is set in the face of the magnetic field generation device of at least one side simultaneously.

5. acceleration transducer as claimed in claim 4 is characterized in that, described a pair of semi-girder is the tabular beam that the track when having perpendicular to this semi-girder deflection forms the plane of face.

6. acceleration transducer as claimed in claim 1 is characterized in that, the described magnetic field generation device on described each free end is divided into several respectively and is provided with.

7. acceleration transducer as claimed in claim 1 is characterized in that, described a pair of semi-girder roughly is same linearity and is provided with, simultaneously each free end mutually back to and be provided with.

8. acceleration transducer as claimed in claim 7 is characterized in that, each stiff end of described a pair of semi-girder is fixed on the same support component.

9. acceleration transducer as claimed in claim 1 is characterized in that, changes the magneto-resistance effect element of resistance value when described magnetic field measuring device is input magnetic field corresponding to this magnetic direction.

10. acceleration transducer as claimed in claim 9 is characterized in that, when not quickening in any direction, described magneto-resistance effect element is approximately perpendicular to described magnetic direction.

11. acceleration transducer as claimed in claim 9 is characterized in that also comprising the differential voltage measurement mechanism, it possesses the bridge circuit that is made of described a pair of magneto-resistance effect element, measures simultaneously from the differential voltage of this bridge circuit output.

12. an acceleration transducer is characterized in that comprising:

At least the elastomeric element that has a degree of freedom on the direction;

N pole-face and S pole-face are constituted by one and are installed on magnetic field generation device on the described elastomeric element towards equidirectional; And

Be respectively provided to few each magnetic field measuring device that can measure magnetic direction in the face of the N pole-face of this magnetic field generation device and S pole-face;

Wherein, described each magnetic field measuring device is formed by the magneto-resistance effect element that changes resistance value corresponding to magnetic direction respectively, and the magnetic direction that configuration simultaneously can measure becomes equidirectional.

13. acceleration transducer as claimed in claim 12 is characterized in that also comprising the bridge circuit of measuring the differential voltage between described each magneto-resistance effect element.

14. acceleration transducer as claimed in claim 13 is characterized in that, described each magneto-resistance effect element is faced described N pole-face and S pole-face respectively and respectively is provided with two.

15. acceleration transducer as claimed in claim 14, it is characterized in that, described four magneto-resistance effect elements are connected side by side and formed described bridge circuit in chips, form voltage simultaneously and apply with terminal and differential voltage measurement terminal on this chip.

16. an acceleration transducer is characterized in that comprising:

A pair of semi-girder, its stiff end is arranged on the same straight line or on the position of almost parallel, described each free end has can be along the degree of freedom of equidirectional deflection to free-ended direction mutually on the contrary;

The pair of magnetic field generation device, N pole-face and S pole-face constitute and are installed in respectively on the free end of described each semi-girder towards the equidirectional one;

Each magnetic field measuring device of at least one the measurement magnetic direction that is provided with separately with the S pole-face in the face of the N pole-face of each magnetic field generation device respectively;

Wherein, described each magnetic field measuring device is formed by the magneto-resistance effect element that changes resistance value corresponding to magnetic direction respectively, and being provided with simultaneously by its magnetic direction that can measure in the face of described each magnetic field generation device becomes same direction.

17. acceleration transducer as claimed in claim 16, it is characterized in that, measurement mechanism as acceleration on the length direction of measuring described semi-girder, in the face of the N pole-face of the described magnetic field generation device of a side and opposite side and S pole-face the group that is made of four described magneto-resistance effect elements at least is set respectively, simultaneously, track when measuring along the described semi-girder of deflection forms face and perpendicular to the measurement mechanism of the acceleration on the direction of the length direction of described semi-girder, is provided with at least by four described magneto-resistance effect element groups identical with the magneto-resistance effect element group of measurement mechanism described acceleration that constitute in addition.

18. acceleration transducer as claimed in claim 17 is characterized in that, is used to measure all directions acceleration and by each magneto-resistance effect element that each component is arranged, and is provided with each bridge circuit of measuring the differential voltage between described each magneto-resistance effect element.

19. acceleration transducer as claimed in claim 18, it is characterized in that, in a chip, form described each magneto-resistance effect element in the face of described each magnetic field generation device, formation voltage applies with terminal and differential voltage measurement and uses terminal on each chip simultaneously, thereby constitutes described bridge circuit.

20. acceleration transducer as claimed in claim 19 is characterized in that, on described each chip, described each magneto-resistance effect element that is formed on described each chip has equidirectional.

21. acceleration transducer as claimed in claim 17, it is characterized in that, described a pair of semi-girder has degree of freedom on the torsional direction of this beam, simultaneously, be respectively provided to the described magnetic field measuring device of another torsional direction of the magnetic direction that the twist operation of a few measurement by described semi-girder change in the face of the N pole-face of at least one described magnetic field generation device and S pole-face, each magnetic field measuring device that described torsional direction is used is formed by the magneto-resistance effect element that changes resistance value corresponding to magnetic direction respectively, and the magnetic direction that can measure is set simultaneously becomes same direction.

22. acceleration transducer as claimed in claim 21 is characterized in that also comprising to possess the bridge circuit of measuring the differential voltage between each magneto-resistance effect element that described torsional direction uses.

23. acceleration transducer as claimed in claim 22 is characterized in that, each magneto-resistance effect element that described torsional direction is used is faced described N pole-face and S pole-face respectively and respectively is provided with two.

24. acceleration transducer as claimed in claim 23, it is characterized in that, four magneto-resistance effect elements that described torsional direction is used are connected side by side and formed described bridge circuit in chips, form voltage simultaneously and apply with terminal and differential voltage measurement terminal on this chip.

25. acceleration transducer as claimed in claim 17 is characterized in that, described a pair of semi-girder is the tabular beam that the track when having perpendicular to this semi-girder deflection forms the plane of face.

26. acceleration transducer as claimed in claim 16 is characterized in that, described magnetic field generation device is a U font magnet.

27. acceleration transducer as claimed in claim 26 is characterized in that also being provided with the ferromagnetism body at opposition side position of the formation face of the N utmost point that covers described U font magnet and the S utmost point.

28. acceleration transducer as claimed in claim 26 is characterized in that, in each free end of described each semi-girder, described each magnetic field generation device is divided into a plurality of respectively.

29. acceleration transducer as claimed in claim 1, it is characterized in that also being provided with the support component of the stiff end of the described semi-girder that supports at least one side, simultaneously, this support component is installed in as on the fixed part of a part that is fixed on the acceleration transducer on the acceleration analysis object, is provided with between described support component and the fixed part and can measures the mutual traverse measuring device that relatively moves.

30. acceleration transducer as claimed in claim 29 is characterized in that, described traverse measuring device has measurement by described support component and relatively moving of described fixed part and the function of the stress of being energized.

31. acceleration transducer as claimed in claim 30 is characterized in that, described traverse measuring device is corresponding to described support component and relatively moving of fixed part and the shear stress of being energized and export the piezoelectric element of electric signal.

32. acceleration transducer as claimed in claim 29 is characterized in that, the weight with extra fine quality is set on the described support component.

33. an acceleration transducer is characterized in that comprising,

Measure the acceleration measurement device of the acceleration on the prescribed direction; And

Measure resonant frequency and be higher than this device and identical or be different from another acceleration measurement device of the acceleration on the direction of described acceleration measurement device.

34. an electronic installation is characterized in that it possesses acceleration transducer as claimed in claim 1.

35. a hard disk drive is characterized in that it possesses acceleration transducer as claimed in claim 1.

36. electronic installation as claimed in claim 34 is characterized in that, the length direction that constitutes a pair of semi-girder of described acceleration transducer is set on the surface level under the user mode of electronic installation.

37. the hard disk drive with acceleration transducer as claimed in claim 29 is characterized in that, the moving direction of measuring by described traverse measuring device is set in seeking on the rail direction of the head-slider that is equipped on the hard disk drive.

38. acceleration measurement method, it is characterized in that, utilize its stiff end to be arranged on the same straight line on the contrary mutually or on the position of almost parallel to free-ended direction, and described each free end has and can measure the magnetic direction that produces from each magnetic field generation device that is installed on described each free end along a pair of semi-girder of the degree of freedom of equidirectional deflection, and based on the acceleration at least two direction of principal axis of its measure of the change.

39. acceleration measurement method as claimed in claim 38 is characterized in that, based on the combination of the variation of each magnetic direction that measures from described each magnetic field generation device, measures acceleration.

40. acceleration measurement method as claimed in claim 39 is characterized in that, is equidirectional or rightabout described combination based on each magnetic direction that measures from described each magnetic field generation device, measures acceleration.

41. acceleration measurement method as claimed in claim 38 is characterized in that, based on described a pair of semi-girder because of reversing the magnetic direction that changes, measure his axial acceleration.

42. acceleration measurement method as claimed in claim 38 is characterized in that, comes the mode of measured resistance value to measure described magnetic direction by the magneto-resistance effect element that changes because of the magnetic field input.

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