JPH10213405A - Spherical body sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction type new spherical body sensor, which senses the arbitrary, free movement applied from the outside. SOLUTION: The following parts are provided. A case 1 comprises a nonmagnetic body having at least the lower surface in a curved-surface shape. A magnetic response member 3 is contained in the case 1 so that the member is freely moved in accordance with gravity. A coil part 2 is provided at the specified arrangement at least at the above described lower surface of the case 1 and generates the induced output voltage in response to the relative position of the magnetic response member 3. Then, the case 1 is rolled, fluctuated or inclined in response to the movement applied on the case 1 from the outside. The magnetic response member 3 is relatively displaced in the case 1 in response to the motion of the case 1. The induced output voltage generated in a coil part 2 is changed in response to the displacement. Thus, the induced output signal, which senses the displacement of the case 1 in response to the movement applied from the above described outside, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spherical or hemispherical or partial sphere or other curved external shape, which converts an externally applied motion into a rolling motion or a swaying motion, or tilts. The present invention relates to a novel sphere sensor which detects a motion applied from the outside.

[0002]

2. Description of the Related Art Conventionally known position sensors include a linear sensor for detecting a linear position and a rotation sensor for detecting a rotational position. There are several detection methods such as an electromagnetic induction method and an optical method, but the optical method has a limit in detection resolution. For example, a mouse is known as a cursor pointing device of a personal computer. A conventional mouse separates the rotational motion of an omni-directional rotator into X-axis and Y-axis components, and optically moves the X-axis and Y-axis components respectively. Is attached. However, since the detection resolution of the optical incremental pulse encoder is limited, it is not possible to increase the number of generated pulses with respect to the moving distance, and it is troublesome to move the cursor over a long distance. On the other hand, in the electromagnetic induction type sensor, by using circuit processing such as phase difference counting,
The detection resolution can be refined by electric processing. However, in the conventional inductive rotation sensor, since the size of the device is insufficiently reduced, if the device is configured by providing two axes of X and Y, the device becomes large.
A compact pointing device such as a mouse could not be constructed.

Incidentally, in the conventionally known inductive position detecting device, there is a differential transformer as a linear position detecting device, and a resolver as a rotational position detecting device. The differential transformer excites one primary winding in one phase, and performs differential operation in accordance with a linear position of an iron core interlocking with a detection target position at each arrangement position of two differentially connected secondary windings. The resulting reluctance, resulting in 1
The voltage amplitude level of the phase induction output AC signal indicates the linear position of the iron core. The resolver excites a plurality of primary windings in one phase, extracts an output AC signal indicating a sine phase amplitude function characteristic from the sine phase extracting secondary winding, and extracts the cosine phase extracting secondary winding from the secondary winding. An output AC signal showing an amplitude function characteristic of a cosine phase is taken out. This two-phase resolver output is a known R
By using a conversion circuit called a / D converter, the phase value corresponding to the detected rotational position can be digitally measured. Also, an output AC signal in which a plurality of primary windings are respectively excited by AC signals of a plurality of phases such as a sine phase and a cosine phase, and the AC signal is electrically phase-shifted according to a linear position or a rotational position to be detected. There is also known a technique of digitally measuring a linear position or a rotational position of a detection target by measuring the electric phase shift amount of the output AC signal (see, for example, Japanese Patent Application Laid-Open No. 49-10 / 1979).
7758, JP-A-53-106065, JP-A-55
No. 13891, No. 1-25286).

[0004]

However, all of the conventionally known inductive position detecting devices measure a linear position or a rotational position along a predetermined guide or axis, and are free from any externally applied free position. No movement could be detected. In general, an inductive position detecting device is structurally non-contact, and can be manufactured easily and inexpensively with a simple configuration such as a coil and an iron piece. If it can be configured as a device for detecting motion, wide applications and applications are expected. For example, if the device can be configured as a device that detects two-axis movement of one operator in the X-Y directions, an operator having a simple configuration that can replace an existing two-axis operator such as a mouse is provided. It can be applied to other applications and uses that did not exist before. The present invention has been made in view of the above points, and has as its object to provide a novel inductive spherical sensor capable of detecting any free movement applied from the outside.

[0005]

A spherical sensor according to the present invention comprises a case made of a non-magnetic material having at least a curved lower surface, a magnetic responsive member housed movably in accordance with gravity in the case, and A coil portion that is installed at a predetermined position on at least the lower surface of the case and generates an induction output signal in response to a relative position of the magnetically responsive member, and that the case is rotated in response to a movement externally applied to the case. The magnetic responsive member is relatively displaced in the case according to the movement of the case, and the induced output signal generated in the coil portion changes in accordance with the displacement, and the magnetic response member is changed from the outside. It is characterized in that the displacement of the case according to the applied movement is detected.

[0006] At least the lower surface of the case has a curved shape, and at least on the lower surface, a coil portion is provided in a predetermined arrangement and moves together with the case. The case rolls or swings or tilts in response to a movement externally applied to the case, and the coil portion arrangement surface rolls or swings with the movement of the case in response to any free movement applied from the outside. Or tilt. A magnetic response member is movably accommodated in the case according to gravity, and the magnetic response member is always oriented in the direction of gravity, so that the magnetic response member moves relative to each other in the case according to the movement of the case. Movement,
It will be displaced relatively to the coil part arranged on the lower surface of the case. The induced output signal generated in the coil portion changes according to the change in the positional relationship between the magnetic response member and the coil portion, and the displacement of the case according to the movement applied from the outside is detected.

The method of applying an external force to the sphere sensor of the present invention may be arbitrarily set according to the purpose of use. For example,
Place this sphere sensor on any horizontal surface such as a table
Place the case with the bottom side down. In this case, the case is rolled or rocked by applying an external force directly to the case by a human hand or the like. Thus, the sphere sensor of the present invention can be used as a novel device for detecting the amount of operation by a human hand. Alternatively, the spherical sensor may be suspended in a pendulum shape and applied for the purpose of detecting vibration or the like. Alternatively, the sphere sensor may be fixedly installed on an object, and may be applied for the purpose of tilt detection based on the case tilting according to the tilt of the object. In addition, the swing width of the instantaneous vibration or inclination is
Since it corresponds to acceleration, it can be mounted on a vehicle or the like and applied as an inclinometer and / or accelerometer.

[0008] The case may consist entirely of a full sphere, or a hemisphere or partial sphere. In addition, the shape is not limited to a perfect sphere, and may be an elliptical sphere or the like, and it is sufficient that a curved surface is partially formed (that is, at least on the lower surface). The magnetic response member may be formed of a solid sphere. Alternatively, it may be made of a magnetic fluid. Alternatively, it may be made of magnetic powder. Or,
It may include both a solid magnetic response member and a magnetic fluid or magnetic powder.

[0009] In one embodiment, the coil section includes a plurality of poles arranged along a first direction, and each pole has an electromagnetic inductive coupling by primary and secondary coils. Including a first detection coil unit and a plurality of poles arranged along a second direction orthogonal to the first direction, each pole has an electromagnetic induction coupling by primary and secondary coils And a second detection coil section for detecting an X-axis component position detection signal and a Y-axis component position detection signal corresponding to the relative position of the magnetic response member. It is good to output each from a part. As a result, the rolling or swinging movement of the case can be separated into the X-axis component and the Y-axis component and detected, so that one sphere sensor according to the present invention can be used for externally detecting all directions (excluding the vertical direction). Any free movement added from the motion can be detected. Further, using a sphere sensor having such first and second detection coil portions, a cursor X-axis based on the X-axis component position detection signal and the Y-axis component position detection signal output from the sphere sensor is used. If a circuit for forming a drive signal and a cursor Y-axis drive signal is provided, a novel spherical mouse can be provided. By using such a spherical mouse, the cursor can be easily rolled by hand at a place having an arbitrary plane, such as a table, to perform a cursor operation.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1A is an external perspective view showing an example of a sphere sensor according to the present invention, and FIG.
FIG. 2 is an external perspective view showing an example of a magnetic response member 3 housed therein, and FIG. 2C is a developed view showing an example of a coil (pole) arrangement of a coil unit 2 arranged on a lower surface of a case 1.
In FIG. 1, a case 1 has a complete spherical shape in its outer shape, has a complete spherical space inside, and is made of a nonmagnetic material such as plastic or stainless steel. In the case 1, a steel ball 3a made of a magnetic material such as iron as shown in FIG. 2B is housed as the magnetic response member 3, and the steel ball 3a is movable in the case 1 according to gravity. It is.

A coil portion 2 composed of one or a plurality of coils is mounted on the outer lower surface of the case 1. Coil section 2
Each of the coils is a thin type in which the winding axis direction is a direction perpendicular to the surface of the case 1 and does not hinder the rolling of the case 1. Of course, the coil section 2 is such that a thin coil is attached to the outside of the case 1 and is molded from above with a non-magnetic material so that the surface becomes smooth and the case 1 is smoothly rolled. It may be appropriately manufactured and processed so that it can be secured. However, this point is a design matter and will not be particularly described. The coil section 2 may be attached to the inside of the case 1 instead of the outside. Also in this case, the surface is smoothed by molding with a non-magnetic substance or the like from above to ensure smooth rolling of the steel ball 3a. In addition, even if the case 1 is a perfect sphere, it can be divided into half and so on.
It is appropriately designed so that the magnetic responsive member 3 (steel ball 3a) is easily housed in the manufacturing operation.

The arrangement and connection of the individual coils in the coil section 2 and the mode of excitation may be appropriately designed according to the detection principle to be adopted. The coil arrangement of the coil unit 2 shown in FIG. 1C shows an example configured according to a resolver type position detection principle. In FIG. 1C, the coil unit 2 includes a plurality of poles arranged along a first direction (for convenience, referred to as an X-axis direction). Including a first detection coil unit 2X having an inductive coupling unit and a plurality of poles arranged along a second direction (conveniently referred to as a Y-axis direction) orthogonal to the first direction. Each of the poles includes a second detection coil unit 2Y having an electromagnetic inductive coupling by primary and secondary coils.

The first detection coil section 2X includes four poles arranged at regular intervals in the X-axis direction, and each pole has at least two poles.
Secondary coils 21, 22, 23, 24 are provided. That is, four at least secondary coils 21, 22, 23, 2 arranged at regular intervals in the X-axis direction along the curved surface of case 1.
4 and a primary coil (not shown) constitute a first detection coil unit 2X. Similarly, the second detection coil unit 2Y includes four poles arranged at equal intervals in the Y-axis direction, and each pole is at least a secondary coil 25, 26, 27, 2
8 and includes a primary coil (not shown). The pole arrangement of the first detection coil unit 2X (the arrangement of the secondary coils 21 to 24) and the pole arrangement of the second detection coil unit 2Y (the arrangement of the secondary coils 25 to 28) are on the curved surface of the case 1. They intersect as shown.

Although the arrangement of the primary coils is not particularly shown, any suitable arrangement may be used as long as the magnetic field excited by the primary coils can be applied to the corresponding secondary coils. . For example, individual primary coils may be provided so as to overlap at the same position corresponding to individual secondary coils, respectively, or case 1
1 to surround all the secondary coils within an appropriate range of
One primary coil may be provided, or a plurality of primary coils may be provided so as to surround a plurality of secondary coils in some groups. In any case, when the resolver type position detection principle is followed or when the differential transformer principle described later is followed, all the primary coils are excited by an in-phase (one-phase) AC signal.

The magnetic response member 3 housed in the case 1
Represents each 2 in each detection coil unit 2X, 2Y.
The magnetic coupling (ie, electromagnetic induction coupling) between the secondary coil and the corresponding primary coil is changed according to the proximity positional relationship with the secondary coil. An output signal corresponding to the close positional relationship is output from each of the detection coil units 2X and 2Y. Therefore, an X-axis component position detection signal and a Y-axis component position detection signal corresponding to the relative position of the magnetic response member 3 can be obtained based on the outputs of the detection coil units 2X and 2Y. The size (diameter) of the steel ball 3a as the magnetic response member 3 may be appropriately designed according to the resolver type position detection principle, similarly to the arrangement interval of each secondary coil.
For example, in the illustrated example, the magnetic response member 3, that is, the steel ball 3a
Is drawn so as to have a diameter substantially corresponding to the arrangement range of the two adjacent secondary coils 21 and 22. However, the present invention is not limited to this, and it is possible in design to reduce or increase an appropriate amount of the diameter dimension.

Regarding the principle of position detection of the resolver type,
The first detection coil unit 2X will be described as an example.
By changing the corresponding position of a with respect to each of the secondary coils 21 to 24, the magnetic coupling between the primary coil and each of the secondary coils 21 to 24 is changed in accordance with the X-axis component position. The induction output AC signal amplitude-modulated according to the axial component position is induced in each of the secondary coils 21 to 24 with different amplitude function characteristics according to the displacement of the secondary coils 21 to 24. Each of the induced output AC signals induced in each of the secondary coils 21 to 24 has the same electrical phase because the primary coil is commonly excited by the single-phase AC signal, and its amplitude function is steel. It changes in accordance with the approach or distance of the sphere 3a to or from each secondary coil.

When the resolver principle is adopted, the amplitude function of the induced output AC signal generated in the four secondary coils 21 to 24 in the detection coil unit 2X is represented by a sine function (s is added in the figure) and a cosine function (FIG. , A minus sine function (/ s (s bar) in the figure),
The arrangement intervals of the secondary coils 21 to 24 and the magnetic response member 3 (that is, the steel ball 3a) correspond to a minus cosine function (/ c (c bar) is added in the figure). Set the size. Depending on various conditions, the arrangement of each coil can be slightly changed, and the size of the magnetic response member 3 (steel ball 3a) can also be changed. Therefore, the arrangement of each coil can be appropriately adjusted so as to obtain desired functional characteristics. Alternatively, by adjusting the secondary output level by electrical amplification, a desired amplitude function characteristic can be finally obtained. Therefore, each secondary coil 21
Although the arrangement of 〜24 and the size of the magnetic response member 3 (steel ball 3a) are important, absolute accuracy is not required and can be set or changed as appropriate in design. The same applies to the second detection coil unit 2Y. The amplitude functions of the induced output AC signals generated in the four secondary coils 25 to 28 are represented by a sine function (s), a cosine function (c), and a minus sine function (/ s) and the negative cosine function (/ c).
In the specification, for convenience of notation, a bar symbol indicating inversion is described as “/ (slash)”, which corresponds to the bar symbol in the figure.

FIG. 2 is a circuit diagram of the primary and secondary coils in the first detection coil section 2X. A common excitation AC signal (indicated by sinωt for convenience of explanation) is applied to the primary coil. . In response to the excitation of the primary coil, the steel ball 3a
The AC signal having an amplitude value corresponding to the X-axis component position is guided to each of the secondary coils 21 to 24. The respective induced voltage levels correspond to the two-phase function characteristics sinθ and cos corresponding to the X-axis component position.
θ and the function characteristics −sin θ and −cos θ of the opposite phase are shown. That is, the induced output signals of the respective secondary coils 21 to 24 are amplitude-modulated by the two-phase function characteristics sinθ and cosθ and the opposite-phase function characteristics −sinθ and −cosθ corresponding to the X-axis component position. Are output respectively. Note that θ is proportional to the X-axis component position, for example, θ = 2π (x / p). Here, x is an X-axis component position, and p is a length corresponding to one cycle of the above function. For convenience of explanation, coefficients according to other conditions, such as the number of turns of the coil, are omitted, and the secondary coil 21 is used as a sine phase, and the output signal is represented by “sin θ · sin ω
t ”, and the output signal of the secondary coil 22 is represented by“ cos θ · sin ωt ”with the cosine phase being used. The secondary coil 23 has a negative sine phase, and its output signal is represented by “−sin θ · sin ωt”. The secondary coil 24 has a negative sine phase and its output signal is “−cos θ · sin
ωt ”. A first output AC signal A (= 2 sin θ · sin ωt) having a sine function amplitude function is obtained by differentially combining the induced outputs of the sine phase and the minus sine phase. The second output AC signal B (= 2 cos θ · sin) having a cosine function amplitude function is obtained by differentially combining the induced outputs of the cosine phase and the negative cosine phase.
ωt) is obtained. Note that, for simplicity of expression, the coefficient “2” is omitted, and hereinafter, the first output AC signal A is represented by “sinθ · sinωt”, and the second output AC signal B is represented by “cosθ · sinωt”. ".

Thus, the first position corresponding to the X-axis component position x
The first output AC signal A = sinθ · sinωt having the function value sinθ as the amplitude value and the second output AC signal B = having the second function value cosθ corresponding to the same X-axis component position x as the amplitude value cosθ · sinωt is output. According to such a winding configuration, two output AC signals A and B, which are in-phase AC and have a two-phase amplitude function, similar to those obtained in a resolver conventionally known as a rotary position detecting device.
(Sine output and cosine output) to the first detection coil unit 2
It can be seen that X can be obtained. The two-phase output AC signal (A = sin θ · sin ωt and B = cos θ · sin ωt) output from the first detection coil unit 2X can be used in the same manner as the output of a conventionally known resolver. For example, as shown in FIG. 2, the output AC signals A and B of the detection coil unit 2X are converted into an appropriate digital phase detection circuit 4.
0 and the sine function sinθ and the cosine function cosθ
The digital phase detection method detects the phase value θ of
Digital data Dx of the X-axis component position x can be obtained. As a digital phase detection method employed in the digital phase detection circuit 40, a known RD (resolver-digital) converter may be applied,
A new method developed by the present inventors may be adopted.

The second detection coil section 2Y is also shown in FIG.
Similarly, the primary and secondary coil circuits can be configured to output a resolver type two-phase output AC signal indicating the Y-axis component position. Then, similarly to the above, the digital data Dy indicating the Y-axis component position can be obtained by adopting the digital phase detection method. Thus, the X-axis component position and Y obtained from the first detection coil unit 2X and the second detection coil unit 2Y, respectively.
The combination of the axial component position data Dx and Dy makes it possible to obtain data for detecting the amount of displacement of the motion applied externally to the case 1 in all directions (excluding the vertical direction).

The coil arrangement of the coil section 2 is not limited to the above example, but can be modified as appropriate. For example, FIG. 3A shows an example in which the secondary coils 21 'to 24' and 25 'to 28' for each pole of the first and second detection coil units 2X and 2Y are arranged in a fan shape. Each secondary coil 21 'with a dash sign
1 to 24 'and 25' to 28 'are secondary coils 21 to 21 having the same reference numerals without dashes in FIG.
24 and 25 to 28, and have the same technical significance. 1C differs from the arrangement of FIG. 1C in that each of the secondary coils 21 'to 24' and 25 'to 28' has a fan-shaped arrangement as shown. FIG. 3 shows such a fan-shaped arrangement of each pole, for example, with respect to the pole of the secondary coil 21 ′ (sine pole of the first detection coil unit 2X).
One secondary coil may be wound in a predetermined fan shape as shown in FIG. 3B, or a plurality of secondary coils may be arranged in a predetermined fan shape as shown in FIG. 3C. Is also good. When one pole is constituted by a plurality of secondary coils as shown in FIG. 3C, similarly to the above, these in-phase secondary coils are connected in series to generate one output signal for the pole. To do. FIG. 4 shows that the secondary coils 21 ″ to 24 ″ and 25 ″ to 28 ″ for each pole of the first and second detection coil units 2X and 2Y are arranged in a semicircle, An example in which the second detection coil units 2X and 2Y are stacked in two layers is shown.

The number of primary and secondary coils and the number of phases (or poles) in the coil section 2 are not limited to those shown in the figure, and the design can be changed as appropriate according to the configuration of a known inductive type position detecting device. It is. For example, the present invention is not limited to a configuration in which a sine phase and a cosine phase resolver-type outputs are generated, but may be a configuration in which three-phase synchro-type outputs with a phase shift of 120 degrees are generated, or an appropriate configuration thereof. In addition,
The coil arrangement of the coil unit 2 is not limited to the lower surface of the case 1,
It may be provided over the entire surface. In this case, for example, one hemisphere of the spherical case 1 is shared by one set of the first and second detection coil units 2X and 2Y as described above, and another hemisphere is another set as described above. And the first and second detection coil sections 2X and 2Y can share the arrangement. Of course, other arrangements can be appropriately designed. Thus, if the coil portion 2 is provided in an appropriate arrangement over the entire surface of the case 1 made of a complete sphere, even if the case 1 is used to roll the case 1 more than one turn, detection is performed over the entire turn. You can get the output. On the other hand, when the coil portion 2 is arranged corresponding to the lower surface of the case 1 as shown in each of the illustrated examples, if the magnetic response member 3 (steel ball 3a) is out of the range corresponding to the coil portion 2, Since detection becomes impossible, the detectable range is limited. In such a case, the spherical sensor of the present invention can be used to detect a motion that swings the case 1 within a predetermined range or to detect a tilt.

The shape of the case 1 is not limited to a perfect sphere, but may be a hemisphere or another partial sphere as shown in FIG. Of course, case 1 with a hemispherical shape
Shall be covered with an appropriate lid. Case 1
May be an elliptical sphere or a shape having a partially curved surface.

The shape of the magnetic response member 3 is not limited to the sphere 3a as in the above embodiment, but may be a partial sphere (or partial circle) 3b as shown in FIG. The material is not limited to a magnetic material such as iron, but may be a good conductor such as copper. It is already known that when a good conductor is used as the magnetic response member 3, a change in magnetoresistance is obtained due to eddy current loss, and the coupling coefficient between the primary and secondary coils is changed. It is also known that a combination of a magnetic substance and a good conductor complementarily increases the rate of change of the magnetic coupling coefficient to improve the detection sensitivity. This may be adopted. Further, the magnetic response member 3 is not limited to a fixed-shaped object, and may be a non-fixed-shaped object (fluid or powder). FIG. 6B shows an example in which an appropriate amount of magnetic fluid 3 c is stored as the magnetic response member 3. FIG. 6C shows an example in which an appropriate amount of magnetic powder 3 d is stored as the magnetic response member 3. In this case, the material is not limited to the fine powder 3d, and may be a granular material such as iron sand. FIG. 6D shows an example in which a combination of a steel ball 3a and an appropriate amount of a magnetic fluid 3c (or powder or granules) is used as the magnetic response member 3. The hybrid type as shown in FIG. 6D can improve the S / N ratio of the detection output signal and can smooth the change of the output signal. As another example, the inside of the case 1 is filled with a non-magnetic viscous fluid, and the steel ball 2a is stored therein,
You may make it give a buffering action to a sudden movement.

The method of applying an external force to the spherical sensor of the present invention may be arbitrarily set according to the purpose of use. FIGS. 7A and 7B schematically show some examples of use. FIG. 7A shows this spherical sensor on an arbitrary horizontal surface 11 such as a table.
The case 1 is placed with its lower surface (that is, the surface on which the coil unit 2 is arranged) facing down. In this case, the case 1 is rolled or rocked by applying an external force directly to the case 1 by a human hand or the like. Thus, the spherical sensor of the present invention can be used as a novel device for detecting the amount of operation by a human hand. (B) shows an example in which this spherical sensor is suspended in a pendulum shape and applied for the purpose of vibration detection or the like. (C) shows a case 1 in which the spherical sensor is fixedly installed on the object 12 and the case 1 is changed according to the inclination of the object 12.
An example will be described in which the present invention is applied for the purpose of detecting the inclination based on the inclination of. In addition, the swing width of the instantaneous vibration or inclination is
Since it corresponds to acceleration, it can be mounted on a vehicle or the like as the object 12 and applied as an inclinometer and / or accelerometer.

Regardless of whether the case 1 is of a full spherical type as shown in FIG. 1 or of a hemispherical (or partial spherical) type as shown in FIG. If the first and second detection coil units 2X and 2Y as shown are provided to enable two-directional position detection,
It can be used as a spherical mouse. That is,
Place the case 1 on the table and roll it by hand in any direction. Accordingly, the first and second detection coil units 2
Output signals corresponding to the movement amounts of the X-axis position component and the Y-axis position component are obtained from X and 2Y, and the output signals are processed by the above-described digital phase detection circuit 40, whereby X
Position data Dx and Dy of the axis position component and the Y axis position component are obtained. Since the position data Dx and Dy are absolute values of a plurality of bits, the position data Dx and Dy are converted to displacement detection / incremental pulse forming circuits 81 and 81 as shown in FIG.
The processing is performed at 82, and the incremental pulses Px and Py may be generated at every constant displacement. The incremental pulses Px and Py are used as signals for instructing the X and Y movements of the cursor. Since a circuit for forming an incremental pulse based on the input of absolute position data that changes with time is known, each of the circuits 81, 8
The details of 2 are omitted.

FIG. 9 shows an example in which a known RD (resolver-digital) converter is applied as the digital phase detection circuit 40. Secondary coils 21 and 2 of coil unit 2
A = sin θ · sin ωt and B = cos θ · sin ωt of the resolver type two-phase output AC signals output from the analog multipliers 30 and 31 are input to the analog multipliers 30 and 31, respectively. The phase generating circuit 32 sequentially generates digital data of the phase angle φ, and the sine / cosine generating circuit 33 generates an analog signal of a sine value sinφ and a cosine value cosφ corresponding to the phase angle φ. In the multiplier 30, the sine phase output AC signal A = sin
θ · sinωt is multiplied by the cosine value cosφ from the sine / cosine generating circuit 33 to obtain “cosφ · sinθ · sinωt”.
Get. The other multiplier 31 multiplies the cosine phase output AC signal B = cos θ · sin ωt by the sine value sin φ from the sine / cosine generating circuit 33 to obtain “sin φ · c
osθ · sinωt ”. In the subtractor 34, both multipliers 30,
The difference between the output signals of the phase generator 31 is obtained, and the phase generation operation of the phase generator 32 is sequentially controlled by the output of the subtractor 34 as follows. That is, the generated phase angle φ of the phase generating circuit 32 is reset to 0 at first, and then sequentially increased,
When the output of the subtractor 34 becomes 0, the increase is stopped. The output of the subtractor 34 becomes 0 because “cosφ · sinθ · sinω
t ”=“ sin φ · cos θ · sin ωt ”, that is, φ = θ is satisfied, and the phase generation circuit 32
From the output AC signals A and B
And the digital value of the phase angle θ of the amplitude function.
Accordingly, a reset trigger is periodically given at an arbitrary timing to sequentially reset the generated phase angle φ of the phase generation circuit 32 to 0, start incrementing the phase angle φ, and the output of the subtractor 34 becomes 0 When this happens, the increment is stopped and digital data of the phase angle θ is obtained. It is known that the phase generating circuit 32 is configured to include an up / down counter and a VCO, and the output of the subtractor 34 drives the VCO to control the up / down counting operation of the up / down counter. In that case, a periodic reset trigger is unnecessary.

An error occurs in the electrical AC phase ωt of the secondary output AC signal due to a change in the impedance of the primary and secondary coils of the coil unit 2 due to a temperature change or the like. , Sinωt
Is automatically canceled out, which is advantageous.
On the other hand, conventionally known two-phase AC signals (for example, sin
ωt and cosωt), a system in which an electric phase shift is generated in a one-phase output AC signal by exciting in
The output phase error based on such a temperature change cannot be removed. By the way, the conventional RD as described above
Since the phase detection circuit including the converter is a tracking comparison method, there is a problem that a clock delay occurs when φ is tracked and counted, resulting in poor response. Therefore, the present inventors have developed a novel phase detection circuit as described below, and it is convenient to use this.

FIG. 10 shows an embodiment of a novel digital phase detection circuit 40 applicable to the detection coil unit 2X (or 2Y) for one axis in the spherical sensor according to the present invention. 10, in a detection circuit section 41, a predetermined high-speed clock pulse CK is counted by a counter 42, and an excitation AC signal (for example, sinωt) is generated from an excitation signal generation circuit 43 based on the count value. To the primary coil. The modulo number of the counter 42 corresponds to one cycle of the exciting AC signal, and for convenience of explanation, the count value 0 is set to the reference sine signal si.
It is assumed that it corresponds to the 0 phase of nωt. Coil section 2
The two-phase output AC signals A = sinθ · sinωt and B = cosθ · sinωt output from the secondary coils 21 to 24 are input to the detection circuit unit 41.

In the detection circuit section 41, the first AC output signal A = sin θ · sin ωt is input to the phase shift circuit 44, and its electric phase is phase-shifted by a predetermined amount.
AC signal A '= sin advanced by 0 degree and phase shifted
θ · cosωt is obtained. Further, in the detection circuit section 41, an addition circuit 45 and a subtraction circuit 46 are provided. In the addition circuit 45, the phase-shifted AC signal A ′ = sinθ · cosωt output from the phase shift circuit 44 and the coil The second AC output signal B = cosθ · sinωt output from the secondary coils 21 to 24 of the unit 10 is added, and the added output is B + A ′ = cosθ · sinωt + sinθ · cosω.
As a result, a first electrical AC signal Y1 can be obtained, which can be represented by a simplified expression t = sin (ωt + θ). In the subtraction circuit 46, the phase-shifted AC signal A ′ = sin θ · cosωt and the second
Is subtracted from the AC output signal B = cos θ · sin ωt, and as a subtraction output, BA ′ = cos θ · sin ωt−sin θ · cos
A second electrical AC signal Y2 can be obtained, which can be represented by a simplified expression ωt = sin (ωt−θ). Thus, the first electric AC signal Y1 = sin (ω) having the electric phase angle (+ θ) shifted in the positive direction corresponding to the detection target position (x)
t + θ) and a second electric AC signal Y2 = sin (ωt−θ) having an electric phase angle (−θ) shifted in the negative direction corresponding to the same detection target position (x). Each is obtained by electrical processing.

The output signals Y1 and Y2 of the adder circuit 45 and the subtractor circuit 46 are input to zero-cross detection circuits 47 and 48, respectively, where the respective zero-crosses are detected. As a method of detecting the zero cross, for example, a zero cross in which the amplitude values of the signals Y1 and Y2 change from negative to positive, that is, zero phase is detected. The zero-cross detection pulse, that is, the zero-phase detection pulse detected by each of the circuits 47 and 48 is a latch pulse LP
1 and LP2 are input to the latch circuits 49 and 50. The latch circuits 49 and 50 latch the count value of the counter 42 at the timing of the respective latch pulses LP1 and LP2. As described above, the modulo number of the counter 42 corresponds to one cycle of the exciting AC signal, and the count value of 0 corresponds to the 0 phase of the reference sine signal sinωt. The data D1 and D2 latched by the latch circuits 49 and 50 respectively correspond to the phase shifts of the output signals Y1 and Y2 with respect to the reference sine signal sinωt. The output of each of the latch circuits 49 and 50 is input to the error calculation circuit 51, and "(D1 + D2) / 2"
Is calculated. Note that this calculation is actually “D
This may be performed by shifting the addition result of the binary data of “1 + D2” by one bit lower.

Here, the influence of the length of the wiring cable between the coil section 2 and the detection circuit section 41 and the influence of each length of the coil section 2 are described.
Taking into account that an impedance change due to a temperature change or the like occurs in the secondary and secondary coils, the phase variation error of the output signal is indicated by “± d”. Is represented by A = sinθ · sin (ωt ± d) A ′ = sinθ · cos (ωt ± d) B = cosθ · sin (ωt ± d) Y1 = sin (ωt ± d + θ) Y2 = sin (ωt ± d−θ) D1 = ± d + θ D2 = ± d-θ

That is, each phase shift measurement data D1, D
No. 2 performs the phase shift count using the reference sine signal sinωt as the reference phase, so that a value including the phase variation error “± d” is obtained as described above. Therefore, the error calculation circuit 51 calculates “(D1 + D2) / 2” to obtain (D1 + D2) / 2 = {(± d + θ) + (± d−θ)} / 2.
= ± 2d / 2 = ± d, the phase variation error “± d” can be calculated.

The data of the phase variation error “± d” obtained by the error calculation circuit 51 is supplied to a subtraction circuit 52, and is subtracted from one phase shift measurement data D1. That is,
In the subtraction circuit 52, since the subtraction of “D1− (± d)” is performed, D1− (± d) = ± d + θ− (± d) = θ, and the correct detection after removing the phase variation error “± d” Digital data indicating the phase difference θ is obtained. As described above, according to the present invention, it can be understood that the phase fluctuation error “± d” is canceled and only the correct phase difference θ corresponding to the detection target position x is extracted.

This point will be further described with reference to FIG. In FIG. 11, a sine signal sin as a reference for phase measurement is shown.
ωt and the waveforms near the zero phase of the first and second AC signals Y1 and Y2 are shown. FIG. 11A shows a case where the phase fluctuation error is plus (+ d), and FIG. −
d) is shown. In the case of FIG. 7A, the reference sine signal sin
The 0 phase of the first signal Y1 is “θ +
d ”, and the corresponding phase difference detection data D1 indicates a phase difference corresponding to“ θ + d ”. Also, the second signal Y2 with respect to the zero phase of the reference sine signal sinωt
Is delayed by “−θ + d”, and the corresponding phase difference detection data D2 indicates a phase difference corresponding to “−θ + d”. In this case, in the error calculation circuit 51, (D1 + D2) / 2 = {(+ d + θ) + (+ d−θ)} / 2
= + 2d / 2 = + d, the phase variation error "+ d" is calculated. Then, D1-(+ d) = + d + θ − (+ d) = θ is calculated by the subtraction circuit 52, and the correct phase difference θ is extracted.

In the case of FIG. 11B, the reference sine signal si
The zero phase of the first signal Y1 is “θ” with respect to the zero phase of nωt.
−d ”, and the corresponding phase difference detection data D1 indicates a phase difference corresponding to“ θ−d ”. Also, the second signal Y with respect to the zero phase of the reference sine signal sinωt
The 0 phase of No. 2 is delayed by “−θ−d”, and the corresponding phase difference detection data D2 indicates a phase difference corresponding to “−θ−d”. In this case, in the error calculation circuit 51, (D1 + D2) / 2 = {(− d + θ) + (− d−θ)} / 2
= −2d / 2 = −d, the phase variation error “−d” is calculated. Then, D1-(− d) = − d + θ − (− d) = θ is calculated by the subtraction circuit 52, and a correct phase difference θ is extracted. In the subtraction circuit 52, A subtraction of “D2− (± d)” may be performed, and in principle, the correct phase difference θ
It can be understood that data (−θ) reflecting the above is obtained.

As can be understood from FIG. 11, the electrical phase difference between the first signal Y1 and the second signal Y2 is 2θ, and the phase variation error “± d” between them is always obtained.
, Which is twice the value of the accurate phase difference θ. Therefore, the configuration of the circuit portion including the latch circuits 49 and 50, the error calculation circuit 51, and the subtraction circuit 52 in FIG. 10 is appropriately changed to a configuration for directly obtaining the electrical phase difference 2θ between the signals Y1 and Y2. It may be. For example, from the point in time when the pulse LP1 corresponding to the zero phase of the first signal Y1 output from the zero-cross detection circuit 47 occurs, the pulse LP2 corresponding to the zero phase of the second signal Y2 output from the zero-cross detection circuit 48 By gating by an appropriate means until the time of occurrence, and counting this gate period, digital data corresponding to the electrical phase difference (2θ) can be obtained in which the phase fluctuation error “± d” is canceled. , Is shifted one bit lower, data corresponding to θ is obtained.

In the above embodiment, the output of the same counter 42 is latched by the latch circuit 49 for latching + θ and the latch circuit 50 for latching -θ. No particular reference is made to the sign of. However, the sign of the data may be subjected to appropriate design processing so as to conform to the gist of the present invention. For example, assuming that the modulo number of the counter 42 is 4096 (decimal notation), the digital counts 0 to 4095 may be appropriately processed according to the phase angle of 0 to 360 degrees. In the simplest design example, the most significant bit of the count output of the counter 42 is a sign bit, the digital counts 0 to 2047 correspond to +0 to +180 degrees, and the digital counts 2048 to 4095 correspond to −180 to −0.
The arithmetic processing may be performed in accordance with the degree.
Alternatively, as another example, by converting input data or output data of the latch circuit 50 into a two's complement number, the digital counts 4095-0 are made to correspond to negative angle data expressions of -360 degrees to -0 degrees. You may.

By the way, there is no particular problem when the case 1 is stationary, but when it changes with time, the phase angle θ corresponding thereto also changes with time. In that case, each output signal Y of the addition circuit 45 and the subtraction circuit 46
1 and Y2 are not constant values but show dynamic characteristics that change with time according to the moving speed. When this is represented by θ (t), the output signals Y1 and Y2 are Y1 = sin {ωt ± d + θ (t)} Y2 = sin {ωt ± d−θ (t)} That is, with respect to the frequency of the reference signal sinωt, the leading output signal Y1 makes a frequency transition in a direction of increasing the frequency in accordance with + θ (t), and the lagging output signal Y2 becomes −θ.
Frequency transition is performed in a direction in which the frequency becomes lower according to (t).
Under such dynamic characteristics, the periods of the signals Y1 and Y2 transition in the opposite directions one after another for each period of the reference signal sinωt. The measurement time reference for D2 will be different, and both data D1 and D2 will simply be
By simply performing the calculations at 1, 52, the accurate phase variation error “±
d "cannot be obtained.

Even when the detection target is changing with time, the phase difference θ corresponding to the position of the detection target every moment.
It is desirable to be able to detect accurately. Therefore, in order to solve the above-described problem, even when the detection target position is changing with time, the phase difference θ corresponding to the detection target position can be detected every moment. An improvement measure will be described with reference to FIG.

FIG. 12 shows a modified example of a part of the error calculating circuit 51 and the subtracting circuit 52 in the detecting circuit part 41 of FIG. 10, and the configuration of other parts not shown is the same as that of FIG. 10. It may be. When the position to be detected is temporally changing, the phase difference θ corresponding to the position is represented by +
When represented by θ (t) and −θ (t), each output signal Y
1, Y2 can be represented as described above. The phase shift measurement value data D1 and D2 obtained by the latch circuits 49 and 50 respectively become D1 = ± d + θ (t) and D2 = ± d−θ (t). In this case, ± d + θ (t) repeatedly temporally changes in the plus direction from 0 ° to 360 ° in accordance with the temporal change of θ. Further, ± d-θ (t) repeatedly and temporally changes in the minus direction from 360 degrees to 0 degrees in accordance with the temporal change of θ. Therefore, ± d
+ Θ (t) ≠ ± d-θ (t), but sometimes both changes intersect, in which case ± d + θ (t) = ±
d−θ (t) holds. Thus, ± d + θ (t) =
When ± d-θ (t) holds, the output signals Y1, Y2
Of the latch pulses LP1 and LP2 corresponding to the respective zero-cross detection timings.
Are coincident with each other.

In FIG. 12, the coincidence detecting circuit 53 detects that the generation timings of the latch pulses LP1 and LP2 corresponding to the zero-cross detection timing of each of the output signals Y1 and Y2 coincide, and responds to this detection. A coincidence detection pulse EQP is generated. On the other hand, the time variation determination circuit 54
Then, it is determined by a suitable means (for example, a means for detecting the presence or absence of a temporal change in the value of the one phase difference measurement data D1) to determine that the mode is one in which the detection target inclination angle θ temporally changes. , The time-varying mode signal T
Output M. A selector 55 is provided between the error calculation circuit 51 and the subtraction circuit 52, and when the time variation mode signal TM is not generated, that is, TM = “0”, that is, the detection target inclination angle θ changes with time. If not, the output of the error calculation circuit 51 added to the selector input B is selected and input to the subtraction circuit 52. Thus, when the input B of the selector 55 is selected, the circuit of FIG.
It operates equivalently to the circuit of FIG. That is, when the detection target linear position x is stationary, the output data of the error calculation circuit 51 is supplied to the subtraction circuit 5 via the input B of the selector 55.
2 and operates similarly to the circuit of FIG.

On the other hand, when the time-varying mode signal TM is generated, that is, when TM = “1”, that is, when the position to be detected is temporally changing, the latch circuit 56 applied to the input A of the selector 55 Select output and subtraction circuit 5
Enter 2 When the time variation mode signal TM is "1",
When the coincidence detection pulse EQP is generated, the condition of the AND gate 57 is satisfied and the coincidence detection pulse EQP is generated.
A pulse responsive to P is output from the AND gate 57,
A latch instruction is given to the latch circuit 56. The latch circuit 56 latches the output count data of the counter 42 according to the latch instruction. Here, when the coincidence detection pulse EQP occurs, the output of the counter 42 is latched by the latch circuits 49 and 50 at the same time.
= D2, and the data latched by the latch circuit 56 is
This corresponds to D1 or D2 (where D1 = D2).

The coincidence detection pulse EQP is generated when the zero-cross detection timing of each of the output signals Y1 and Y2 coincides, that is, when “± d + θ (t) = ± d−θ (t)” is satisfied. Therefore, in response to this, the latch circuit 5
6 is D1 or D2 (where D1
= D2), which is equivalent to (D1 + D2) / 2. This means that (D1 + D2) / 2 = [{± d + θ (t)} + {± d−θ (t)}]
/ 2 = 2 (± d) / 2 = ± d, and the data latched by the latch circuit 56 accurately indicates the phase variation error “± d”. .

As described above, when the position to be detected fluctuates with time, data accurately indicating the phase fluctuation error "± d" is latched by the latch circuit 56 in accordance with the coincidence detection pulse EQP. Is supplied to the subtraction circuit 52 via the input A of the selector 55. Therefore, the subtraction circuit 52 can obtain data θ (or θ (t) if it fluctuates over time) that accurately responds only to the detection target position from which the phase fluctuation error “± d” has been removed. In addition,
In FIG. 12, the AND gate 57 may be omitted, and the coincidence detection pulse EQP may be directly supplied to the latch control input of the latch circuit 56. Also, the latch circuit 56
In addition, not only the output count data of the counter 42 but also the output data “± d” of the error calculation circuit 51 may be latched as shown by a broken line in FIG. In that case,
Since the output timing of the output data of the error calculation circuit 51 corresponding to the generation timing of the coincidence detection pulse EQP is slightly delayed due to the circuit operation delay of the latch circuits 49 and 50 and the error calculation circuit 51, an appropriate After performing the time delay adjustment, the output of the error calculation circuit 51 may be latched in the latch circuit 56. When the detection circuit section 41 is configured in consideration of only the dynamic characteristics, FIG.
It will be understood that the two circuits 51 and selector 55 and one of the latch circuits 49 or 50 of FIG. 1 may be omitted.

FIG. 13 shows another embodiment of a phase difference detection calculation method capable of canceling the phase fluctuation error "± d". The resolver-type first and second AC output signals A and B output from the secondary coils 21 to 24 of the coil unit 2 are input to the detection circuit unit 60, and the first and second AC output signals A and B are input to the detection circuit unit 60 as in the example of FIG. AC output signal A = sinθ · sinωt is input to the phase shift circuit 44, and its electric phase is phase-shifted by a predetermined amount, and the phase-shifted AC signal A ′ = sinθ ·
cosωt is obtained. In the subtraction circuit 46, the phase-shifted AC signal A ′ = sin θ · cos ωt and the second AC output signal B = cos θ · sin ωt are subtracted. sinωt-sinθ ・ c
As a result, an electrical AC signal Y2 can be obtained, which can be represented by a simplified expression of osωt = sin (ωt−θ). The output signal Y2 of the subtraction circuit 46 is input to the zero-cross detection circuit 48, and a latch pulse LP2 is output in response to the zero-cross detection.
Is input to

The difference between the embodiment of FIG. 13 and the embodiment of FIG. 10 is that the phase shift amount θ is obtained from the AC signal Y2 = sin (ωt−θ) including the electrical phase shift corresponding to the position to be detected.
Are different from each other in the reference phase when measuring. FIG.
In the example of 0, the reference phase when measuring the phase shift amount θ is:
This is the zero phase of the reference sine signal sinωt, which is not input to the coil unit 2 and includes a phase variation error “± d” based on a coil impedance change due to a temperature change or other various factors. Not something.
Therefore, in the example of FIG. 10, two AC signals Y1 = si
n (ωt + θ) and Y2 = sin (ωt−θ), and by obtaining the electrical phase difference, the phase variation error “±
"d" is offset. On the other hand, FIG.
In the embodiment, the first and second signals output from the coil unit 2 are
By forming a reference phase for measuring the amount of phase shift θ based on the AC output signals A and B, and making the reference phase itself include the phase fluctuation error “± d”, The fluctuation error “± d” is excluded.

That is, in the detection circuit section 60, the first and second AC output signals A and B output from the coil section 2 are input to zero cross detection circuits 61 and 62, respectively, and the respective zero crosses are detected. . The zero-cross detection circuits 61 and 62 respond to either a zero-cross where the amplitude values of the input signals A and B change from negative to positive (so-called 0 phase) or a zero-cross where the amplitude value changes from positive to negative (so-called 180 degree phase). Output a zero-cross detection pulse. This is because sinθ and cosθ, which determine the positive and negative polarities of the amplitudes of the signals A and B, are arbitrarily positive or negative according to the value of θ. This is because it is necessary to detect a zero cross every 180 degrees. Both zero cross detection circuits 61,
The zero-crossing detection pulse output from the OR circuit 62
3 or the output of the OR circuit 63 is
The pulse is input to a divide-by-2 pulse circuit 64 (including, for example, a 分 -divider circuit such as a T-flip-flop and a pulse output AND gate). , A zero-crossing detection pulse corresponding to only the zero phase is output as the reference phase signal pulse RP. This reference phase signal pulse R
P is provided to the reset input of counter 65. The counter 65 constantly counts a predetermined clock pulse CK, and its count value is repeatedly reset to 0 in accordance with the reference phase signal pulse RP. The output of the counter 65 is input to the latch circuit 50, and the count value is latched by the latch circuit 50 at the generation timing of the latch pulse LP2. The data D latched by the latch circuit 50 is output as measurement data of the phase difference θ corresponding to the detection target position x.

The first and second AC output signals A and B output from the coil unit 2 are A = sin θ · sin ω, respectively.
t, B = cos θ · sin ωt, and the electric phases are in phase. Therefore, a zero cross should be detected at the same timing, but since the amplitude coefficient fluctuates with the sine function sin θ and the cosine function cos θ, either amplitude level may be 0 or close to 0, and such In one case, virtually no zero crossing can be detected. Therefore, in this embodiment, zero-cross detection processing is performed for each of the two AC output signals A = sin θ · sin ωt and B = cos θ · sin ωt, and either of the zero-cross detection outputs is OR-combined, so that one of the amplitude levels is obtained. It is characterized in that even if the zero-cross detection cannot be performed due to a small amplitude, the other zero-cross detection output signal having the larger amplitude level can be used.

In the case of the example of FIG. 13, the phase fluctuation error due to a change in the coil impedance of the coil section 2 is, for example, "-
d ", the AC signal Y2 output from the subtraction circuit 46 becomes Y2 = sin, as shown in FIG.
(Ωt−d−θ). In this case, the output signals A and B of the coil unit 2 have amplitude values sinθ and cosθ corresponding to θ, respectively, and A = sinθ · si as illustrated in FIG.
n (ωt−d) and B = cos θ · sin (ωt−d), which include the phase fluctuation error. Therefore, the reference phase signal pulse RP obtained at the timing shown in FIG. 14C based on the zero-cross detection is shifted from the original zero phase of the reference sine signal sinωt by a phase variation error −d. . Therefore, this reference phase signal pulse RP
, The output AC signal Y2 of the subtraction circuit 46 = sin
If the phase shift amount of (ωt−d−θ) is measured, an accurate value θ from which the phase fluctuation error −d is removed can be obtained.

When the device conditions such as the wiring length of the coil section 2 are determined, the impedance change mainly depends on the temperature. Then, the phase variation error ± d is
This corresponds to data indicating the temperature of the surrounding environment where the spherical sensor is provided. Therefore, in the circuit having the circuit 51 for calculating the phase variation error ± d as in the embodiment of FIG. 10, the data of the phase variation error ± d obtained therefrom can be appropriately output as the temperature detection data. Therefore, according to such a configuration of the present invention, not only can the position be detected by one spherical sensor, but also data indicating the temperature of the surrounding environment of the sensor can be obtained.
It has an excellent effect. Of course, there is an excellent effect that high-precision detection in response to the detection target position can be performed without being affected by a change in impedance on the sensor side due to a temperature change or the like and a length of the wiring cable. Further, since the examples of FIGS. 10 and 13 are methods for measuring a phase difference in an AC signal, it is possible to perform detection excellent in high-speed response as compared with the detection method shown in FIG. It has excellent effects.

The digital phase detection circuit 40 as described above
Are provided for each of the detection coil units 2X and 2Y, and generate X-axis component position data Dx and Y-axis component position data Dy corresponding to the respective output signals. In that case, the common hardware device of the digital phase detection circuit 40 is
In order to calculate the phase difference data θ for each of the plurality of detection coil units 2X and 2Y, it is preferable to share the time division data. The measurement of the phase component θ included in the output signals of the detection coil units 2X and 2Y is not limited to the calculation of the digital absolute value as described above, and other design changes are possible. For example, an analog signal (voltage or current) corresponding to the phase component θ may be output. FIG.
As described above, the incremental pulses Px and Py may be generated according to the increase (displacement) of the phase component θ. Further, the phase value θ may be frequency-converted, and a clock pulse having a frequency corresponding to the phase value θ may be repeatedly generated. Alternatively, without performing the calculation for obtaining the phase component θ, the amplitude value sin θ or cos of the output signal A or B is used.
θ may be used as it is as position detection information. Alternatively, the amplitude value sinθ or cos of the output signal A or B
is subjected to voltage-frequency conversion to obtain the amplitude value sin θ or c.
A clock pulse having a frequency corresponding to osθ may be repeatedly generated. In short, the method of processing the output signal of the sphere sensor of the present invention may be any method irrespective of digital / analog.

In each of the above embodiments, the coil 2
And the principle of detection by the magnetic response member 3 may be constituted by a known phase shift type position detection principle. For example,
In the coil unit shown in FIG. 2, the relationship between the primary coil and the secondary coil is reversed so that the sine-phase coil 21 and the minus-sine-phase coil 23 are switched to the opposite sine signal s.
are excited by inωt and −sinωt, and the cosine phase coil 22 and the negative cosine phase coil 24 are excited by cosine signals cosωt and −cosωt having phases opposite to each other. An output signal sin (ωt−θ) including the shift θ may be obtained. Alternatively, the detection principle by the coil unit 2 and the magnetic response member 3 may be configured to obtain an analog detection output based on a known differential transformer type position detection principle.

Alternatively, in each of the above embodiments, the configuration of the coil unit 2 is not constituted to include a pair of a primary coil and a secondary coil, but is constituted by only one coil.
The one coil is driven at a constant voltage by a predetermined AC signal, and a current change based on a change in inductance generated according to an amount of a magnetic body (magnetic responsive member 3) penetrating into the coil is measured. May be obtained. In that case, the required measurement should be performed by a method of measuring an amplitude change of an output signal responsive to the current change, or a method of measuring a phase change between output signals at each end of the coil responsive to the current change. Can be. In addition, the configuration of the detection unit using the coil unit 2 and the magnetic response member 3 can be arbitrarily modified. In addition, the spherical sensor may be configured by selectively adopting a part of the new and meaningful configuration shown in the above embodiment.

[0055]

As described above, according to the present invention, at least the lower surface of the case has a curved shape, and at least the lower surface has the coil portion disposed in a predetermined arrangement so that it can move with the case. The case rolls, swings or tilts in response to a movement externally applied to the case, and the coil portion arrangement surface rolls with the movement of the case in response to any free movement applied from the outside. Move or swing or tilt. And, inside this case, a magnetic response member is housed movably according to gravity,
Since the magnetic responsive member is always oriented in the direction of gravity, the magnetic responsive member relatively moves within the case in response to the movement of the case, and is relatively displaced with respect to the coil portion disposed on the lower surface of the case. Will do. The induced output signal generated in the coil portion changes according to the change in the positional relationship between the magnetic response member and the coil portion, and the displacement of the case according to the movement applied from the outside can be detected. Therefore, there is provided a novel sensor which is structurally non-contact and can detect any externally applied free movement easily and inexpensively with a simple configuration using an inductive type detection device. It is expected to have a wide range of applications and applications.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing an embodiment of a sphere sensor according to the present invention, in which FIG. 1A is a schematic view of the appearance, FIG. 1B is a diagram showing an example of a magnetic response member, and FIG. FIG.

FIG. 2 shows one of two detection coil units constituting the coil unit.
FIG. 1 is a circuit diagram showing two circuit configuration examples.

FIG. 3 is a developed view showing another example of the coil arrangement of the coil unit.

FIG. 4 is a developed view showing still another example of the coil arrangement of the coil unit.

FIG. 5 is a schematic external view showing another embodiment of the sphere sensor according to the present invention.

FIG. 6 is a view showing a modification of the magnetic response member in FIG. 1;

FIG. 7 is a view showing an example of use of a sphere sensor according to the present invention.

FIG. 8 is a block diagram showing a configuration example in which incremental pulses are respectively generated based on X-axis position component data and Y-axis position component data obtained from two detection coil units constituting the coil unit.

FIG. 9 is a block diagram showing an example of a phase detection type measurement circuit applicable to the sphere sensor according to the present invention.

FIG. 10 is a block diagram showing another example of a phase detection type measurement circuit applicable to the sphere sensor according to the present invention.

FIG. 11 is an operation explanatory diagram of FIG. 10;

FIG. 12 is a block diagram showing a modification example added to the circuit of FIG. 10;

FIG. 13 is a block diagram showing still another example of a phase detection type measurement circuit applicable to the sphere sensor according to the present invention.

FIG. 14 is an operation explanatory diagram of FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Coil part 2X, 2Y Detection coil part 21-24 along a predetermined direction Secondary coil 3 Magnetic response member 3a Steel ball 40 Digital phase detection circuit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobuyuki Akazu 2-1453-43, Niibori, Higashiyamato-shi, Tokyo (72) Inventor Kazuya Sakamoto 1-1-5 Kawasaki, Hamura-shi, Tokyo, MAC Hamura Court II- 405 (72) Inventor Hiroshi Sakamoto 896-8 Yamada, Kawagoe-shi, Saitama (72) Inventor Akio Yamamoto 1-13-29 Nishi, Kunitachi-shi, Tokyo KM Heights 101

Claims (9)

[Claims] 1. A case made of a non-magnetic material having at least a curved lower surface, a magnetic responsive member housed movably in accordance with gravity in the case, and a predetermined arrangement at least on the lower surface of the case. A coil portion that generates an induction output signal in response to the relative position of the magnetic response member, and rolls, swings or tilts the case in response to a movement externally applied to the case, and moves the case. The magnetic responsive member is relatively displaced in the case in response to the change, and the induced output signal generated in the coil portion changes in accordance with the displacement, and the displacement of the case in response to the externally applied movement is detected. A spherical sensor. 2. The sphere sensor according to claim 1, wherein the case is formed entirely of a sphere. 3. The case according to claim 1, wherein the case comprises a partial sphere.
A sphere sensor according to claim 1. 4. The sphere sensor according to claim 1, wherein the magnetic response member is formed of a sphere. 5. The sphere sensor according to claim 1, wherein the magnetic response member is made of a magnetic fluid. 6. The sphere sensor according to claim 1, wherein the magnetic response member is made of a magnetic powder. 7. The sphere sensor according to claim 1, wherein the magnetic response member includes a solid magnetic response member and a magnetic fluid or a magnetic powder. 8. The first detection unit, wherein the coil unit includes a plurality of poles arranged along a first direction, each pole having an electromagnetic inductive coupling by a primary and a secondary coil. A second portion including a coil portion and a plurality of poles arranged along a second direction orthogonal to the first direction, wherein each of the poles has an electromagnetic induction coupling by a primary and a secondary coil; And outputs an X-axis component position detection signal and a Y-axis component position detection signal corresponding to the relative position of the magnetic response member from the first and second detection coil units, respectively. The sphere sensor according to any one of claims 1 to 7, wherein: 9. A cursor X-axis drive signal and a cursor Y-axis based on the sphere sensor according to claim 8, and the X-axis component position detection signal and the Y-axis component position detection signal output from the sphere sensor. A spherical mouse comprising a circuit for forming a drive signal.