JPH0420862A - Rotation detecting apparatus - Google Patents

Abstract

PURPOSE:To miniaturize an apparatus by providing the constitution wherein a rotation detecting means comprises a piezoelectric element and is rotated and moved together with a material to be rotated and the electric output corresponding to the rotary angle speed of a rotating member is outputted. CONSTITUTION:In a bimorphic plate 1 which is to become a rotation detecting means, monomorphic plates 1a and 1b forming a pair are stuck together so as to hold a common terminal plate 2 comprising a thin metal plate. The monomorphic plates 1a and 1b are made of piezoelectric ceramics and constituted in such a way that electromotive force is generated across one surface side and the other surface side when the plates are curved or twisted in the thickness direction. Electrodes 3 and 4 are formed on the surface parts of the monomorphic plates 1a and 1b. When a rotary frame member 7 is rotated in the direction of an arrow R in this rotation detecting apparatus, one-end side of the bimorphic plate 1 is rotated and moved in the rotating direction together with the member 7, and the outer end side remains at the initial position by inertia corresponding to the mass of an inertia member 6. Therefore, the torsional displacement occurs between both ends in the longitudinal direction, and the potential having the specified polarity in response to the rotating direction of the member 7 is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a rotation detection device useful for use in electro-acoustic transducers using so-called handphones, portable video camera devices, and the like.

B1 Summary of the Invention The present invention provides a rotation detecting means comprising a piezoelectric element, which is attached to a rotating member that is rotated together with an object to be detected, and is positioned on the axis of rotation of the object to be detected. By attaching it to the rotary member, the rotation detecting means outputs an electrical output according to the rotational angular acceleration of the rotating member, and has good durability against impacts, etc.
The object of the present invention is to provide a rotation detection device that can detect the rotational movement of a rotationally detected object with a high degree of accuracy and is useful for use in an electro-acoustic transducer using a so-called handphone, a portable video camera device, and the like.

Further, in the above-mentioned rotation detecting device, the present invention has the rotation detecting means formed in a plate shape so as to cause torsional displacement as the rotating member rotates, thereby detecting the rotational movement of the rotated object. This allows for high sensitivity.

C9 Prior Art Conventionally, so-called headphone devices, in which a pair of small electro-acoustic transducers are attached and supported near the pinnae of both ears, have been used to create a natural listening sensation as if sound waves were propagating from the outside. A so-called high naural method has been proposed in order to realize the acoustic reproduction that gives the same effect.

This pinaural system applies predetermined phase conversion and signal level conversion to the right channel signal, which is originally reproduced only by the right electro-acoustic transducer, and supplies it to the left electro-acoustic transducer. The right channel signal reproduced only by the acoustic transducer is subjected to predetermined phase conversion and signal level conversion and then supplied to the right electro-acoustic transducer.

In such a pinaural method, it is possible to achieve a good sense of external localization for sounds propagating from the sides and rear, but it is difficult to achieve a good sense of localization outside the head for sounds propagating from the front. Met. and,
In this pinaural system,
As described in Publication No. 42, if the rotational movement of the head is detected and the constants of the phase transformation and signal level transformation are changed according to the detected rotational movement of the head, the propagation from the front can be prevented. It has been proposed that a good sense of extra-head localization can be achieved with respect to sound.

In addition, in a portable video camera device, it is possible to detect the rotational movement of the video camera device and perform predetermined signal processing on the video signal according to the detected rotational movement of the video camera device. It has been proposed that image fluctuations caused by blur can be corrected. Note that such camera shake is caused by repeated rotations in the horizontal direction in a low frequency band below a predetermined frequency of about 5Hz to 100cm, so it can be detected by frequency-selecting the rotational movement of the video camera device. , the effects of camera shake can be effectively corrected.

Therefore, electric power using the pinaural method has traditionally been used.
2. Description of the Related Art Rotation detection devices for detecting the rotational movement of a rotating object such as a head have been proposed for use in acoustic conversion devices, portable video camera devices, and the like.

That is, Japanese Patent Publication No. 54-19242 uses a distance measuring device consisting of a cylinder part and a piston part that are slidably fitted to each other, and one end of the distance measuring device is placed on the user's shoulder at one end of the piston. A device is described in which rotational movement of the user's head with reference to the user's shoulder is detected by attaching one end to the user's head and attaching the other end to the user's head. There is. Also,
Japanese Patent Publication No. 54-19242 describes a device in which a so-called gyroscope device is attached to a user's head to detect rotational movement of the user's head.

Although it is difficult to miniaturize the device configuration and the rotation detection device configured using such a distance JIl measuring device or gyroscope is expensive, it cannot handle rotational movements that cause minute vibrations. cannot be detected accurately.

Note that in the rotation detection device using the gyroscope described above, a magnetic needle can be used instead of the gyroscope. However, a rotation detection device configured using a magnetic needle has poor detection response and cannot accurately detect rotational movement.

In addition, the applicant first used a sound source indicating the reference position,
A rotation detection device for an electro-acoustic conversion device is proposed, which detects the rotational movement of the user's head by measuring the distance to the sound source. That is, this rotation detection device includes a pair of microphone devices attached to the left and right sides of the user's head, and uses these microphone devices to detect the phase of the detection sound emitted from the sound source. The apparatus is configured to detect the respective distances from the sound source to the left and right sides of the user's head. In this rotation detection device, the rotational movement of the user's head is calculated based on changes in distances from the sound source to the left and right sides of the user's head.

As described above, it is difficult to miniaturize a rotation detection device configured using a sound source that indicates a reference position so as to include this sound source and make it portable.

Therefore, this rotation detection device cannot be configured to be used outdoors.

Further, Japanese Patent Application Laid-Open No. 63-272300 describes a rotation detection device constructed using a pair of bimorph plates. This bimorph plate is constructed by bonding a metal plate to a piezoelectric ceramic, for example, and is configured to generate an electromotive force when bent. In this rotation detection i1F, the pair of bimorph plates are cantilevered with their respective ends attached to positions between the paths of the rotating member that is rotated and moved together with the rotationally detected object. Each of these bimorph plates has its other end, which is a free end, extending in opposite directions facing each other. The electrodes of these bimorph plates are formed by the curvature of each bimorph plate caused by the rotation of the rotating member, that is, by the curvature such that the free ends of each bimorph plate are displaced in the same rotational direction with respect to the rotating member. They are connected so that the electromotive forces are added to each other.

In this rotation detection device, when the rotating member performs a rotational movement, each of the bimorph plates is curved according to the angular acceleration of this rotational movement, and an electromotive force corresponding to this curvature can be obtained. That is, in this rotation detection device,
Based on the electromotive force, the rotational speed and rotational angular position of the rotationally detected object can be calculated.

In this rotation detection device, when the rotating member moves in parallel with the rotated object, the free ends of the bimorph plates are displaced in opposite rotational directions relative to the rotating member. This results in a curvature that looks like this. At this time, since the electromotive forces generated by these bimorph plates cancel each other out, only the rotational movement component that is not affected by the parallel movement component of the rotating member is detected.

D9 Problem to be Solved by the Invention Incidentally, in a rotation detection device configured using a pair of bimorph plates as described above, each of the bimorph plates has a so-called cantilevered structure with only one end of each bimorph plate attached to the rotating member. Since they are supported, if an impact is applied from the outside, there is a risk that one end of these bimorph plates will be damaged or fall off from the rotating member.

In addition, this rotation detection device is configured such that each of the bimorph plates extends laterally from the axis of the rotational movement to be detected, so it is difficult to miniaturize the device configuration.

In this rotation detection device, each of the bimorph plates needs to have the same mechanical and electrical characteristics, that is, the amount of curvature per constant angular acceleration of the rotating member and the output voltage level. . In order to prepare a plurality of bimorph plates having the same characteristics, it is necessary to sort the bimorph plates, which makes it difficult to manufacture this rotation detection device.

Therefore, the present invention is proposed in view of the above-mentioned circumstances, and has good durability against impacts, etc., allows for miniaturization of the device configuration, and furthermore, facilitates manufacturing. An object of the present invention is to provide a rotation detection device.

80 Means for Solving the Problems In order to solve the above-mentioned problems and achieve the above-mentioned objects, a rotation detection device according to the present invention includes a rotation detecting device that is made of a piezoelectric element and is attached to a rotating member that rotates together with a rotationally detected object. and an inertial member located on the rotation axis of the rotational object and attached to the rotation detection means, and the rotation detection means generates an electrical output according to the rotational angular acceleration of the rotation member. This is what happens when you output it.

Further, in the rotation detecting device according to the present invention, in the above-described rotation detecting device, the rotation detecting means is formed in a plate shape, one end in the longitudinal direction is attached to the rotating member, and the other end in the longitudinal direction is attached to the inertial member. The rotary member is rotated, and torsional displacement occurs as the rotary member rotates.

F0 action In the rotation detecting device according to the present invention, the rotation detecting means, which is made of a piezoelectric element and is attached to a rotating member that rotates together with the rotated object, detects the rotation of the rotated object when the rotating member rotates. Positioned on the rotation axis! The inertia member attached to the rotation detecting means is deformed by inertia corresponding to the mass of the inertia member attached to the rotation detecting means, and outputs an electrical output corresponding to the rotational angular acceleration of the rotation member.

Furthermore, if the rotation detecting means is formed into a plate shape, one longitudinal end thereof is attached to the rotating member, and an inertia member is attached to the other longitudinal end thereof, the rotation detecting means is twisted as the rotating member rotates. It generates a displacement and outputs an electrical output according to the rotational angular acceleration of the rotating member.

G. Examples Specific examples of the present invention will be described below with reference to the drawings.

The rotation detecting device according to the present invention is a device that detects the rotational angular acceleration of a rotating object such as a user's head or a portable video camera device.

As shown in FIG. 1, this rotation detection device includes a bimorph plate 1 serving as rotation detection means. This bimorph plate 1 includes a pair of first and second monomorph plates 1.
A and 1B are pasted together with a common terminal plate 2 made of a thin metal plate interposed therebetween. Each of the above monomorph plates 1
A and lb are made of piezoelectric ceramic, for example, and are configured to generate an electromotive force between one side and the other side by being curved or twisted in the thickness direction.

On each surface of the bimorph plate 1, as shown in FIGS. 1 and 2, a plurality of electrodes each made of a conductive thin film is formed. That is, the first electrode 3 is formed on the surface portion of the first monomorph plate 1a, which is one side of the bimorph Fif. Further, the second monomorph plate 1b which is the other side of the bimorph Fi,1
A second electrode 4 is formed on the surface portion.

The bimorph plate 1 has one end side in the longitudinal direction,
A rotary frame member 7, which serves as a rotating member that rotates and moves together with the rotationally detected object, is attached to an inner side of the bottom plate. The rotating frame member 7 is made of a material such as metal or resin and is formed in a size that allows the bimorph plate 1 to be accommodated therein. The bimorph plate 1 is arranged so as to be housed within the rotating ring 7. Further, the rotating frame member 7 is provided with leg portions 7b for attaching the rotating frame member 7 to the object to be rotated.

A support member 5 is provided at the other end in the longitudinal direction of the bimorph plate l, that is, at the end of the rotating frame member 7 that is the top plate facing the bottom plate to which the bimorph plate 1 is attached. An inertial member 6 is attached. The inertial member 6 is formed of a material having an appropriate density and has a substantially disk shape and has a predetermined mass. The support member 5
is formed into a substantially cylindrical shape, and one end side is connected to the bimorph plate 1.
A support groove 5a into which the support groove 5a can be inserted is provided so that the support groove 5a is bifurcated, and the inertial member 6 is externally fitted in the middle part. The support member 5 is supported by the bimorph plate 1 by inserting the other end side of the bimorph plate 1 into the support groove 5a. The other end of the support member 5 is rotatably fitted into a support hole 7a formed in the top plate of the rotary frame member 7.

Incidentally, each of the electrodes 3.4 is provided with a voltage extraction terminal 9.4, respectively, so that the electromotive force generated by the torsional displacement of the bimorph plate l as the rotating frame member 70 rotates as shown in FIG. 3 can be taken out. 10 are connected. That is, the first electrode 3 is connected to the first voltage extraction terminal 9
It is connected to the. Then, the second electrode 4
It is connected to the voltage extraction terminal 10 of.

The rotation detecting device according to the present invention configured as described above detects the rotational angular acceleration of the rotating frame member 7 about the longitudinal direction of the bimorph plate 7 of the rotating detected object as indicated by the arrow R in FIG. To detect.

That is, in this rotation detection device, as shown in FIG.
is rotated in the first rotational direction together with the rotating frame member 7, and the other end is held at the initial position by inertia according to the mass of the inertial member 6, so that the distance between both ends in the longitudinal direction is This causes a torsional displacement of .

Due to such torsional displacement of the bimorph plate 1, potentials of predetermined polarities depending on the rotational direction of the rotation frame member 7 are generated in the first and first voltage extraction terminals 910, respectively. That is, in this rotation detection device, when the rotation ring 7 starts to be rotated in the second rotation direction that is the opposite direction to the first rotation direction, the bimorph F
i, 1 is torsionally displaced in a direction opposite to when the rotating frame member 7 starts to be rotated in the first rotation direction.

In this way, the voltage taken out from the first and second voltage take-out terminals 9.10 corresponds to the rotational angular acceleration of the rotating frame member 7, that is, the rotational angular acceleration of the rotationally detected object. It becomes.

When the second rotation detection device is shown in an equivalent circuit, as shown in FIG.
Two capacitors C, , C are connected in series between 0 and 0. In this equivalent circuit, each of the capacitors C, C2 has a capacitance between the first electrode 3 and the common terminal plate 2, and a capacitance between the second electrode 4 and the common terminal plate 2, respectively. It shows. That is, let C be the capacitance of each capacitor C, C2, and
If the potential difference stored in these capacitors C, C, due to the torsional displacement of the bimorph plate 1 is e, then in this rotation detection device, the capacitance is c/2.
Therefore, an electromotive force of 2e can be obtained.

In this rotation detection device, as shown in FIG. 5, the first and second electrodes 3 and 4 are connected to the first voltage extraction terminal 9, and the common terminal plate 2 is connected to the second voltage Also in the rotation detection device configured in this way, which may be connected to the take-out terminal 10, the rotation frame member 7 is connected to the first and second voltage take-out terminals 9 and 10.
A voltage corresponding to the rotational angular acceleration can be extracted.

When this rotation detection device is illustrated by an equivalent circuit, as shown in FIG.
0, the first and second capacitors C+ and Cz are connected in parallel.

That is, in this rotation detection device, the electric capacity I is 2.
It is possible to obtain an electromotive force of c and e.

In this rotation detection device, if the connection is made to increase the capacitance between the first and second voltage extraction terminals 9 and 10, the low cutoff frequency for detecting rotational movement is lowered. It is possible to accurately detect rotational movement in a wide frequency band including low frequency bands.

Further, as shown in FIGS. 8 and 9, the rotation detecting device according to the present invention includes a cylindrical rotating member 11 formed in a cylindrical shape.
and a ring-shaped piezoelectric element 8 serving as a rotation detecting means formed in a ring shape so as to be externally fitted onto the cylindrical rotating member 11. In this rotation detection device, the ring-shaped piezoelectric element 8 is further fitted with a ring-shaped inertia member 12 formed in a ring shape.

In this rotation detection device, the cylindrical rotation member 11
is attached to the object to be rotated and rotated around the axis by the rotation of the object to be rotated, the ring-shaped piezoelectric element 8 is caused to rotate due to the inertia of the ring-shaped inertia member 12 according to it. A displacement occurs such that the outer circumferential side and the inner circumferential side are rotated relative to each other. Such a ring-shaped piezoelectric element 8
The voltage generated by the displacement corresponds to the rotational angular acceleration of the cylindrical rotating member 11, that is, the rotational angular acceleration of the rotationally detected object.

Furthermore, as shown in FIGS. 10 and 11, the rotation detection device according to the present invention includes the ring-shaped piezoelectric element 8 and a cylindrical shape so that the ring-shaped piezoelectric element 8 can be fitted inside. It may also be configured using a cylindrical rotating member 13 formed in a cylindrical shape.

In this rotation detection device, the ring-shaped piezoelectric element 8
is fitted inside the cylindrical rotating member 13. An inertial member support rod 14a is fitted into the insertion hole 8a on the inner side of the ring-shaped piezoelectric element 8. and,
A ring-shaped inertia member 14 formed in a ring shape is externally fitted onto the inertia member support rod 14a. The cylindrical rotating member 13 is provided with leg portions 13a for attaching the cylindrical rotating member I3 to an object to be rotated.

In this rotation detection device, the cylindrical rotation member 13
is attached to the object to be rotated and rotated around the axis by the rotation of the object to be rotated, the ring-shaped piezoelectric element 8 has an inertia according to the mass of the ring-shaped inertia member 14, Displacement occurs such that the outer circumferential side and the inner circumferential side are rotated relative to each other. Such a ring-shaped piezoelectric element 8
The voltage generated by the displacement corresponds to the rotational angular acceleration of the cylindrical rotating member 13, that is, the rotational angular acceleration of the rotationally detected object.

As shown in FIGS. 12 and 13, the rotation detection device according to the present invention includes a disc-shaped piezoelectric element 15 formed in a disc shape, and a disc-shaped piezoelectric element 15! ! ! It may also be constructed using a disc-shaped rotating member 16 formed in a disc-shape so that it can be placed.

In this rotation detection device, the disk-shaped piezoelectric element 15
is attached and supported by the flat lower surface side on the disc-shaped rotating member IG. Then, this disc-shaped piezoelectric element 1
A disk-shaped inertia member 17 formed in a substantially disk shape is placed and attached to the flat upper surface side of the inertia member 5 . The disc-shaped rotating member 16 is provided with leg portions 16a for attaching the disc-shaped rotating member 16 to an object to be rotated.

In this rotation detection device, the disc-shaped rotating member 16
is attached to the object to be rotated and rotated around the axis by the rotation of the object to be rotated, the disc-shaped piezoelectric element 15 has an inertia according to the mass of the disc-shaped inertia member 17, A torsional displacement occurs in which the lower surface side and the upper surface side are rotated relative to each other. The voltage generated by the displacement of the disc-shaped piezoelectric element 15 is applied to the disc-shaped rotating member 1.
6, that is, corresponds to the rotational angular acceleration of the object to be rotated.

In this rotation detection device, the disk-shaped piezoelectric element 15
Instead, the ring-shaped piezoelectric element 8 may be used as shown in FIGS. 14 and 15.

That is, in this rotation detection device, the flat lower surface side of the ring-shaped piezoelectric element 8 is attached to and supported by the disk-shaped rotating member 16, and the flat upper surface side of the ring-shaped piezoelectric element 8 is formed approximately in a disk shape. The disc-shaped inertial member 17 is mounted and attached. In this rotation detection device, when the disc-shaped rotating member 16 is rotated around its axis, the ring-shaped piezoelectric element 8 is moved toward the lower surface and the upper surface by inertia according to the mass of the disc-shaped inertial member 17. This causes a torsional displacement such that the two are rotated relative to each other. The voltage generated by such displacement of the ring-shaped piezoelectric element 8 is the rotational angular acceleration of the disc-shaped rotating member 16, that is,
This corresponds to the rotational angular acceleration of the object to be rotated and detected.

The rotation detection device according to the present invention configured as described above includes:
It is used by being attached to the head/hand portion of a so-called headphone device. This headphone device includes a pair of left ear electro-acoustic transducer and right ear electro-acoustic transducer connected by the head hunt section. In this headphone device, the head hand section is attached to the user's head, thereby positioning and supporting the left ear electro-sound '9 converter near the user's left auricle, and The electro-acoustic transducer for the right ear is positioned and supported near the right auricle of the user.

This rotation detection device has a structure in which the leg portion 7b of the rotary frame member 7, the cylindrical rotary member 11, the leg portion 13a, or the leg portion 16a is attached to an upper side of a substantially central portion of the head hunt portion. is attached to the headphone device.

By attaching the rotation detection device according to the present invention to the headphone device as described above, it is possible to detect the rotational movement of the head to which the headphone device is attached. A predetermined signal processing device is used to change the phase and sound level of the sound reproduced by each of the arithmetic electro-acoustic transducers in accordance with the rotational movement of the head detected by the rotation detection device. By applying this signal processing, it is possible to perform good sound reproduction without so-called in-head localization.

Furthermore, when the rotation detection device according to the present invention is attached to a portable video camera device, it processes video signals in response to rotational movement of the video camera device due to so-called hand shake.
It can be applied to a device that corrects image fluctuation.

H2 Effects of the Invention As mentioned above, in the rotation detection device according to the present invention,
The rotation detecting means, which is made of a piezoelectric element and is attached to a rotating member that rotates and moves together with the rotating detected object, is positioned on the rotation axis of the rotating detected object when the rotating member rotates, and the rotating detecting means It is deformed by the inertia corresponding to the mass of the inertia member attached to the inertia member. Therefore, this rotation detecting means outputs an electrical output according to the rotational angular acceleration of the rotating member.

In this rotation detection device, the rotation detection means can be formed into, for example, a ring shape or a cylindrical shape, so that the device configuration can be made smaller and has good durability against impacts and the like. I can do it.

Furthermore, if the rotation detecting means is formed into a plate shape, one longitudinal end thereof is attached to the rotating member, and an inertia member is attached to the other longitudinal end thereof, the rotation detecting means is twisted as the rotating member rotates. It generates a displacement and outputs an electrical output according to the rotational angular acceleration of the rotating member.

This rotation detection device is constructed by supporting the above-mentioned rotation detection means formed in a plate shape at both ends, so that the device configuration can be made smaller and has good durability against impacts, etc. Can be configured.

Furthermore, since the rotation detection device according to the present invention can be constructed without using a plurality of rotation detection means, it can be easily manufactured without going through a process such as selecting the rotation detection characteristics of the rotation detection means. I can do it.

That is, the present invention can provide a rotation detection device that has good durability against impacts and the like, can be downsized in device configuration, and is easy to manufacture.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of the rotation detection device according to the present invention, FIG. 2 is a plan view showing the configuration of the rotation detection device, and a third view shows the rotation detection device detecting rotational movement. FIG. 4 is a plan view showing a state in which the rotation detection device detects a first rotation direction. FIG. 5 is a plan view showing another example of the connection of the electrodes of the bimorph plate of the rotation detecting device shown in FIG. 1 above. FIG. 6 is a circuit diagram showing an equivalent circuit of the rotation detecting device shown in FIG. 2, and FIG. 7 is a circuit diagram showing an equivalent circuit of the rotation detecting device shown in FIG. 5. FIG. 8 is a perspective view showing the configuration of a rotation detecting device according to the present invention constructed using a ring-shaped piezoelectric element and a ring-shaped inertial member, and FIG. 9 is a perspective view of the rotation detecting device shown in Part 8 above. FIG. 3 is a vertical cross-sectional view showing the configuration. FIG. 10 is a perspective view showing another example of the configuration of the rotation detection device according to the present invention constructed using a ring-shaped piezoelectric element and a ring-shaped inertial member, and FIG. It is a vertical section V showing the configuration of the rotation detection device. FIG. 12 is a perspective view showing the configuration of a rotation detection device according to the present invention constructed using a disk-shaped piezoelectric element and a disk-shaped inertial member, and 131g is a configuration of the rotation detection device shown in FIG. 12 above. FIG. FIG. 14 is a perspective view of the rotation detecting device shown in FIG. 12, and FIG. 15 is a longitudinal sectional view showing the configuration of the rotation detecting device shown in FIG. 14.

Claims (2)

[Claims] (1) Rotation detecting means made of a piezoelectric element and attached to a rotating member that rotates and moves together with the rotated object; and an inertia located on the rotation axis of the rotated object and attached to the rotation detecting means. a rotation detecting device, wherein the rotation detecting means outputs an electrical output according to a rotational angular acceleration of the rotating member. (2) The rotation detection means is formed into a plate shape, has one longitudinal end attached to the rotating member, and has an inertial member attached to the other longitudinal end, and detects torsional displacement as the rotating member rotates. The rotation detecting device according to claim (1), wherein the rotation detecting device rotates.