JPH09236453A - Pole sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pole sensor wherein slit tracks on a rotary slit disk are less and photo-detecting elements are assigned in a centralized manner. SOLUTION: On a rotary slit disk 1, a U-phase slit track 11, a U'-phase slit track 12, a V-phase/W'-phase slit track 13 and a V'-phase/W-phase slit 14 wherein a light/dark slit pattern comprising a light reflection part and a light transmission part is farmed with central angle 45 deg. are assigned. Meanwhile, on a fixed slit disk 2, are a U-phase slit window 21, a U'-phase slit window 22, a V-phase slit window 23, a V'-phase slit window 24, a W-phase slit window 25 and a W'-phase slit window 26 are formed within the range of central angle 15 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical displacement detector, and more particularly to a pole sensor for detecting the magnetic pole position of a three-phase motor.

[0002]

2. Description of the Related Art Conventionally, a pole sensor for detecting a magnetic pole position of an AC servomotor or the like, as shown in FIG. 6, has a rotary slit disk 1'connected to a rotary shaft 6 of an AC servomotor 7, a light source 3 and a rotary slit disk 1 '. , Fixed slit disc 2 '
And the light receiving element 4 and the signal processing circuit 5.
Here, the light source 3, the fixed slit disk 2 ′ and the light receiving element 4 are fixed to the stator side of the motor 7. When the number of magnetic poles P of the AC servomotor 7 is 8, the rotary slit disk 1'has a central angle of 45 as shown in FIG. 7 (1).
Of the U-phase slit track 81 and the U'phase (U phase and 1
Slit track 82 which represents a phase having a phase difference of 80 °)
And V-phase slit track 83 and V'-phase slit (representing a phase different from V-phase by 180 °) slit track 8
4 and W phase slit track 85 and W'phase (W phase and 180
A slit track 86, which represents phases having different phases, is provided, and the fixed slit disk 2 ′ has U-phase slit tracks 81 and U ′, respectively, as shown in FIG. 7B.
Phase slit track 82, V phase slit track 83,
V'phase slit track 84, W phase slit track 8
5, a U-phase slit window 91, a U'-phase slit window 92, a V-phase slit window 93, a V'-phase slit window 94, a W-phase slit window 95, so as to face the W'-phase slit track 86.
The W'phase slit window 96 was formed.

A light beam 31 emitted from a light source 3 passes through a slit pattern of a slit track on the rotating slit disk 1'according to the number of poles of a motor and the magnetic pole positions of U, V and W phases, and further a fixed slit disk. The light passes through the slit window on 2 ', is received by the corresponding light receiving element 4, and is converted into a current signal. The current signal of each light receiving element 4 is converted into a voltage signal by the signal processing circuit 5, differentially amplified, and converted into a rectangular wave signal, and the magnetic pole position of the AC servomotor 7 is detected.

[0004]

In the conventional pole sensor described above, since the slit windows of the fixed slit disk are arranged as centrally as possible, six slit tracks on the rotary slit disk are required, and the size in the radial direction is reduced. There was a problem of getting bigger. Further, as shown in FIG. 8 (1), the slit tracks on the rotary slit disk are U-phase, V-phase, W-phase slit tracks 101 and U ′.
In the case where the number of phase tracks, the V ′ phase, and the W ′ phase slit tracks 102 is set to a minimum of two, in order to differentially detect the signals of the U phase, V phase, and W phase, the number of poles is set to 8 and FIG. As shown in 2), a U-phase slit window 111, a U′-phase slit window 112, a V-phase slit 11 on the fixed slit disk 2 ′.
3, V'phase slit window 114, W phase slit window 115,
Since the W'phase slit window 116, the light source 3, and the light receiving element 4 have to be arranged within the range of mechanical angle ± 240 ° / P = ± 30 °, the reliability is lowered and the reliability is to be improved. There was a problem that the cost would increase.

An object of the present invention is to provide a pole sensor in which the number of slit tracks on the rotary slit disk is small and the light receiving elements are collectively arranged.

[0006]

A first pole sensor of the present invention is a rotary slit disk fixed to a rotary shaft of a motor and having a slit pattern synchronized with a magnetic pole position of the motor, and having an annular shape in a radial direction thereof. The first, second, third, and fourth slit tracks of
Each slit track is divided by a central angle of 360 ° / P (P is the number of magnetic poles of the motor) to form bright and dark slit patterns of the light reflecting portion and the light transmitting portion, and the slit pattern of the second slit track is the first. The center angle of the slit pattern of the slit track is 360 ° / P, and the slit pattern of the third slit track is 18 degrees at the center angle with respect to the slit pattern of the first slit track.
0 ° / P shift, the slit pattern of the fourth slit track is 180 ° / P at the central angle in the direction opposite to the slit patterns of the second slit slit track and the slit pattern of the third slit track. The rotating slit disc, the light source, and the fixed slit fixed so as to face the rotating slit disc are on a first straight line centered on a point on the central axis of the rotating slit disc. First and second slit windows in which a light ray transmitted through the light transmitting portions of the first and second slit tracks is incident, or a light ray from the light source is passed and is incident on the first and second slit tracks, respectively. And the second straight line centered on the above point and forming an angle of 60 ° / P with the first straight line and transmitted through the transparent portions of the third and fourth slit tracks, respectively. The third and fourth slit windows for making the light beam incident or for making the light beam from the light source pass and respectively enter the third and fourth slit tracks, and the first straight line and the first straight line with the point as the center. The light source which is on the third straight line forming an angle of 60 ° / P in the direction opposite to the straight line of 2 and has respectively passed through the light transmitting portions of the third and fourth slit tracks is incident, or From the first slit track, the fixed slit disk having the sixth and fifth slit windows for allowing the light beam from the first slit track to be incident on the third and fourth slit tracks, respectively. The window, the light transmitting portion of the second slit track and the second
Window, the light transmitting portion of the third slit track and the third window,
The light source that has passed through the light transmitting portion of the fourth slit track and the fourth window, the light transmitting portion of the fourth slit track and the fifth window, and the light transmitting portion of the third slit track and the sixth window, respectively. First, to receive the light beam from the
The electric signals output from the second, third, fourth, fifth, and sixth light receiving elements and the first, second, third, fourth, fifth, and sixth light receiving elements are processed to 3 And a signal processing circuit that outputs each phase signal.

The second pole sensor of the present invention is a motor for a motor.
Fixed to the rotating shaft and synchronized with the magnetic pole position of the motor
With a rotating slit disc with a slit pattern
And the first, second, third, and fourth rings that are annular in the radial direction
4 slit tracks are arranged and each slit track is
The central angle is 360 ° / P (P is the number of magnetic poles of the motor)
Light-reflective and non-light-reflective slits are divided into each
The pattern is formed and the slit of the second slit track is
The pattern is the slit pattern of the first slit track.
Angle of 360 ° / P with respect to
The track slit pattern is the first slit track
180 ° / P at the central angle with respect to the slit pattern of
And the slit pattern of the fourth slit track is the first
Second to the slit pattern of the slit track of
Opposite to the slit pattern of the third slit track
Rotating slit disc with a central angle of 180 ° / P
Disk, the distance L from the rotary slit disk₁ Just apart
Positioned light source, the rotating slit disk and the light
A distance L from the rotating slit disc between the sources.₀ Only
It is fixed and provided away from the optical axis of the light source.
Distance r in the direction toward the central axis of the slit disk₀ =
k ・ r₁ (However, k = (L₁ -L ₀ ) / L₁ , R₁ Is
The optical axis of the light source and the central axis of the rotating slit disk
On the first straight line centered on the point
The track halves of the first and second slit tracks, respectively.
The light from the light source located at a distance obtained by multiplying the diameter by a constant k
Pass the wire through the first slit track and the second slit track, respectively.
The first and second slit windows to be incident on the
A second straight line that forms an angle of 60 ° / P with the first straight line
Third and fourth slit tigers on the line from the points
Located at a distance that is equal to the track radius of the track multiplied by a constant k,
A light beam from the light source is passed therethrough to generate a third light beam and a fourth light beam, respectively.
Third and fourth slit windows that enter the slit track
And the first straight line and the second straight line centering on the point
In front of the third straight line that makes an angle of 60 ° / P in the opposite direction
From the marking points, the third and fourth slit track tracks
Located at a distance obtained by multiplying the radius k by a constant k, and
Of the third slit and the fourth slit tiger respectively.
The 6th and 5th slit windows to be incident on the
After passing through the fixed slit disc and the first window,
The light rays reflected by the light reflecting portion of the first slit track,
After passing through the second window, the light reflection of the second slit track
Rays reflected by the projectile, after passing through the third window,
The light beam reflected by the light reflecting portion of the slit track, the fourth
After passing through the window, at the light reflecting part of the 4th slit track
After passing through the reflected light beam, the fifth window, the fourth slip
Light rays reflected by the light-reflecting portion of the track will pass through the sixth window.
After passing through, it is reflected by the light reflection part of the third slit track.
First, each of the received light rays is converted into an electric signal,
The second, third, fourth, fifth and sixth light receiving elements, and the first and first
Output from the second, third, fourth, fifth, and sixth light receiving elements
Signal processing circuit that processes electrical signals and outputs three-phase signals
With the road.

The third pole sensor of the present invention is a motor for a motor.
Fixed to the rotating shaft and synchronized with the magnetic pole position of the motor
With a rotating slit disc with a slit pattern
And the first, second, third, and fourth rings that are annular in the radial direction
4 slit tracks are arranged and each slit track is
The central angle is 360 ° / P (P is the number of magnetic poles of the motor)
Light-reflective and non-light-reflective slits are divided into each
The pattern is formed and the slit of the second slit track is
The pattern is the slit pattern of the first slit track.
Angle of 360 ° / P with respect to
The track slit pattern is the first slit track
180 ° / P at the central angle with respect to the slit pattern of
And the slit pattern of the fourth slit track is the first
Second to the slit pattern of the slit track of
Opposite to the slit pattern of the third slit track
Rotating slit disc with a central angle of 180 ° / P
Disk, the distance L from the rotary slit disk₁ Just apart
Positioned light source, the rotating slit disk and the light
A distance L from the rotating slit disc between the sources.₀ Only
It is fixed and provided away from the optical axis of the light source.
Distance r in the direction toward the central axis of the slit disk₀ =
k ・ r₁ (However, k = (L₁ + L ₀ ) / L₁ , R₁ Is
The optical axis of the light source and the central axis of the rotating slit disk
On the first straight line centered on the point
The track halves of the first and second slit tracks, respectively.
Located at a distance obtained by multiplying the diameter by a constant k,
The light source reflected by the light reflecting portion of the slit track 2
The first and second slit windows for passing the light rays from
Make an angle of 60 ° / P with the first straight line centering on the point
The third and fourth pickpockets from the point on the second straight line
The distance between the track radius and the constant k
The optical slits of the third and fourth slit tracks, respectively.
The light from the light source reflected by the projecting part is supplied to the third and fourth slits.
Window and a first straight line and a second straight line centered on the point
On the third straight line that makes an angle of 60 ° / P in the opposite direction to the line
From the above points, the third and fourth slit tracks, respectively.
Located at a distance equal to the track radius of x multiplied by a constant k,
The light is reflected by the light reflecting portions of the third and fourth slit tracks, respectively.
The sixth and fifth slits that allow the light emitted from the light source to pass therethrough.
Fixed slit disk with a window
After being reflected by the light reflecting part of the slit rack, open the first window
Light rays that pass through are reflected at the light reflection part of the second slit track.
Rays that have passed through the second window after being projected, the third slit
After being reflected by the light reflector of the truck, it passes through the third window
Light rays are reflected by the light reflecting portion of the fourth slit track.
After passing through the fourth window, the fourth slit trap
Light that has passed through the fifth window after being reflected by the light reflector
Line, reflected by the light reflecting part of the third slit track
After that, each of the light rays that have passed through the sixth window is received and an electric signal is received.
No. 1st, 2nd, 3rd, 4th, 5th, 6th
Optical element and first, second, third, fourth, fifth and sixth light receiving
The electric signal output from the element is processed and each three-phase signal is processed.
And a signal processing circuit for outputting.

The number of slit tracks on the rotary slit disk is 4, and when the number of magnetic poles P is 8, the slit window of the fixed slit disk is within the range of 60 ° / 8 × 2 = 15 °, and the light receiving element is Are arranged more intensively than in the conventional case (FIG. 8 (2)). The first pole sensor is a light transmissive type, and the second and third pole sensors are a light reflective type. The signal processing circuit converts the currents output from the first, second, third, fourth, fifth, and sixth light receiving elements into voltages, respectively, first, second, third, fourth, and fourth. 5, a sixth current / voltage conversion circuit, a first differential amplifier circuit for differentially amplifying output voltages of the first and second current / voltage conversion circuits, and third and fourth current / voltage conversion circuits A second differential amplifier circuit that differentially amplifies the output voltage of the circuit; a third differential amplifier circuit that differentially amplifies the output voltage of the fifth and sixth current / voltage conversion circuits; It can be composed of first, second and third comparators for comparing the output voltage of the second and third differential amplifier circuits with a predetermined reference voltage.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a light transmission type pole sensor according to an embodiment of the present invention, and FIG. 2 (1) is a diagram showing a slit track pattern of a rotary slit disk 1.
2 (2) is a diagram showing a slit window arrangement pattern of the fixed slit disk 2, FIG. 3 is a circuit diagram of the signal processing circuit 5, FIG. 4 (1) is a waveform diagram of an output signal of the light receiving element of each phase, FIG.
(2) is a waveform diagram of the output signals of the comparators 60, 61, 62. The number of magnetic poles P is 8. The pole sensor of this embodiment is different from the conventional pole sensor of FIG. 6 only in the rotary slit disk 1 and the fixed slit disk 2.
As shown in FIG. 2A, on the rotary slit disk 1, a U-phase slit track 11, a U′-phase slit track 12, a V-phase, a W′-phase slit track 13, a V′-phase,
The W-phase slit track 14 and the four slit tracks are arranged in this order, and each of the slit tracks 11 to 14 is divided by 360 ° / P = 45 ° to form a bright and dark slit pattern of the light reflecting portion and the light transmitting portion. Are formed. Then, the U'phase slit track 12 is rotated in the clockwise direction by 45 with respect to the U phase slit track 11 (reference line).
° The slit patterns are formed deviated, and the V-phase and W′-phase slit tracks 13 are deviated from the U-phase slit track 11 by 180 ° / P = 22.5 ° in the clockwise direction to form the slit patterns V ′. A slit pattern is formed in the phase W-phase slit track 14 with a 180 ° / P = 22.5 ° offset in the counterclockwise direction with respect to the U-phase slit track 11.

As shown in FIG. 2 (2), a U-phase slit window 21, a U'phase slit window 22, a V-phase slit window 23, a V'phase slit window 24, W are provided on the fixed slit disk 2.
A phase slit window 25, a W'phase slit window 26 and six slit windows are formed. The U-phase slit window 21 is a reference on the radius around the point 0 on the central axis of the rotary slit disk 1 on which the light ray 31 transmitted through the light transmitting portion of the U-phase slit track 11 on the rotary slit disk 1 enters. It is arranged on a straight line with a central angle of 0 ° from the line. The U′-phase slit window 22 is arranged on a straight line having a center angle of 0 ° with respect to the reference line on the radius around the point 0, on which the light ray 31 transmitted through the light transmitting portion of the U′-phase slit track 12 is incident. Has been done. The V phase slit window 23 and the W'phase slit window 26 are V
On the radius centered on the point 0, on which the light beam 31 transmitted through the light transmission part of the phase W'phase slit track 13 is incident, the central angle is ± 60 ° / P with respect to the reference line, that is, ±
It is arranged on a straight line of 7.5 °. The V′-phase slit window 24 and the W-phase slit window 25 are on the radius around the point 0 on which the light ray 31 transmitted through the light transmitting portion of the V′-phase and W-phase slit track 14 is incident, with respect to the reference line. Each of them is arranged on a straight line having a central angle of ± 60 ° / P, that is, ± 7.5 °.

The signal processing circuit 5, as shown in FIG.
Current / conversion circuits 51, 52, 53, 54 for converting the output current (FIG. 4 (1)) of each light receiving element 5 of the phase, U'phase, V phase, V'phase, W phase, and W'phase into voltage. , 55, 56 and current /
Differential amplification circuits 57, 58, 59 for differentially amplifying the output signals of the voltage conversion circuits 51 and 52, 53 and 54, 55 and 56,
And the output signals of the differential amplifier circuits 57, 58, and 59 are rectangular waves, and the U-phase signal and V are phase-shifted by 120 ° in electrical angle.
Comparator 6 that outputs a phase signal and a W phase signal (Fig. 4 (2))
It is composed of 0, 61 and 62. The U-phase slit track 11, the U′-phase slit track 12, the V-phase, the W′-phase slit track 13, the V′-phase, and the W-phase slit track 14 are arranged in the radial direction between the slit patterns. It is optional as long as the relationship is maintained. Further, the fixed slit disk 2 may be provided between the light source 3 and the rotary slit disk 1.

Next, an embodiment of the light reflection type pole sensor will be described. The rotating slit disk of the light-reflecting pole sensor has the same phase relationship between the light-transmitting pole sensor, the slit track, and the slit pattern except that the slit pattern is the light reflecting portion and the non-light reflecting portion.
Further, in the fixed slit disc, the angle indexing origin (point 0 in FIG. 2 (2)) is not on the central axis of the rotating slit disc, and the radial position of each slit window is a light transmissive pole sensor. Deviated. FIG. 5 is a view for explaining the positional relationship between the light source, the rotating slit disk, the fixed slit disk, and the light receiving element in the light reflection type pole sensor. FIG. Light-receiving element 4 reflected by slit disk 1
5 (2) shows a case where the light from the light source 3 is reflected by the rotary slit disk 1, then passes through the slit window and is received by the light receiving element 4.

The distance from the optical axis on the rotary slit disk 1 to the origin 0 _{1 for} angle indexing is r ₁ , and the distance r from the optical axis on the fixed slit disk 2 to the origin 0 _{0 for} angle indexing.
₀ , the distance between the light source 3 and the rotary slit disk 1 is L ₁ ,
The distance between the fixed slit disk 2 and the rotary slit disk 1 is L ₀ , the radial distance from the angle indexing origin 0 ₀ to the slit window is u ₀ , and the radial distance from the angle indexing origin 0 ₁ to the slit pattern (slit when the track radius) and u _1, in the case of FIG. _{5 (1) r 0 = {} (L 1 -L 0) / L 1} r 1 ····· (1) u 0 = {(L 1 - L ₀ ) / L ₁ } u ₁ (2), and in the case of FIG. 5B, r ₀ = {(L ₁ + L ₀ ) / L ₁ } r ₁ (3) ) U ₀ = {(L ₁ + L ₀ ) / L ₁ } u ₁ (4)

That is, in the case of the light reflection type pole sensor of the type shown in FIG.
Each slit window is formed at the position according to the formula (2), and L
_It suffices to dispose the fixed slit disk 2 at a position determined by ₀ and the expression (1). In the case of the light reflection type pole sensor of the type shown in FIG. 5 (2), the fixed slit disk 2 is in accordance with the expression (4). Each slit window may be formed at a position, and the fixed slit disk 2 may be arranged at a position determined by L ₀ and the formula (3). In addition to the AC servo motor, the pole sensor of the present invention can be applied to a motor such as a DC brushless motor or an IPM motor that needs to detect a magnetic pole.

[0016]

As described above, according to the present invention,
By increasing the number of slit tracks on the rotary slit disk as much as possible and by consolidating the arrangement of the light receiving elements, it is possible to irradiate with only one light source, and since the light receiving element can be integrated into one chip, the number of parts is not increased. It is possible to provide a low-cost pole sensor capable of differential detection, resistant to signal noise and temperature change.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a light transmission type pole sensor according to an embodiment of the present invention.

2 is a diagram showing a slit pattern of the rotary slit disc 1 (FIG. 1 (1)) and a slit window arrangement pattern of a fixed slit disc 2 (FIG. 2 (2)) in FIG.

FIG. 3 is a circuit diagram of a signal processing circuit 5.

FIG. 4 is an output signal waveform diagram.

FIG. 5 is a rotary slit disc 1, a fixed slit disc 2, and a light reflecting pole sensor according to another embodiment of the present invention.
3 is a diagram showing a positional relationship between a light source 3 and a light receiving element 4. FIG.

FIG. 6 is a configuration diagram of a conventional pole sensor.

FIG. 7 is a layout view of a slit track of a rotary slit disk and a slit window of a fixed slit disk in a conventional pole sensor.

FIG. 8 is a layout view of a slit track of a rotary slit disk and a slit window of a fixed slit disk in a conventional pole sensor.

[Explanation of symbols]

 1 rotating slit disk 11 U phase slit track 12 U'phase slit track 13 V phase, W'phase slit track 14 V'phase, W phase slit track 2 fixed slit disk 21 U phase slit window 22 U'phase slit window 23 V Phase slit window 24 V'phase slit window 25 W phase slit window 26 W'phase slit window 3 Light source 4 Light receiving element 5 Signal processing circuit 51-56 Current / voltage conversion circuit 57-59 Differential amplifier circuit 60-62 Comparator 6 Shaft 7 motor

Claims (4)

[Claims] 1. A pole sensor for detecting a magnetic pole position of a three-phase motor, which is a rotary slit disk fixed to a rotary shaft of the motor and having a slit pattern synchronized with the magnetic pole position of the motor. There are four annular first, second, third, and fourth slit tracks arranged in the radial direction, and each slit track has a central angle of 360 °.
/ P (P is the number of magnetic poles of the motor) is divided into light and dark slit patterns of the light reflecting portion and the light transmitting portion, and the slit pattern of the second slit track is different from the slit pattern of the first slit track. 36 at the central angle
0 ° / P deviation, the slit pattern of the third slit track is 180 ° / P deviation from the slit pattern of the first slit track at the central angle, and the slit pattern of the fourth slit track is of the first slit track. 180 ° / P at the central angle in the direction opposite to the slit patterns of the second and third slit tracks with respect to the slit pattern
The rotating slit disc, the light source, and the fixed slit slit disc are provided so as to be opposed to the rotating slit disc, and are on a first straight line centered on a point on the central axis of the rotating slit disc. First and second slits in which a light ray transmitted through the light transmitting portions of the first and second slit tracks is incident, or a light ray from the light source is passed to be incident on the first and second slit tracks, respectively. The windows and the second straight line centered on the above point and forming an angle of 60 ° / P with the first straight line respectively enter the light rays transmitted through the transparent portions of the third and fourth slit tracks. Alternatively, third and fourth slit windows that allow light rays from the light source to pass therethrough and enter the third and fourth slit tracks, respectively, and a first straight line and a second straight line about the point. Is the opposite On a third straight line forming an angle of 60 ° / P, the light sources that have respectively transmitted through the light transmitting portions of the third and fourth slit tracks are incident, or the light rays from the light source are transmitted. Fixed slit disk in which sixth and fifth slit windows are formed to enter the third and fourth slit tracks, respectively, a light transmitting portion of the first slit track, the first window, and the second slit track. Light transmitting part and second window, third slit track light transmitting part and third window, fourth slit track light transmitting part and fourth window, fourth slit track light transmitting part The first, the second, the third, the fourth, which receive the light rays from the light source that have respectively passed through the fifth window, the light transmitting portion of the third slit track, and the sixth window, and convert the received light into an electric signal.
Signal processing for processing electric signals output from the fifth and sixth light receiving elements and the first, second, third, fourth, fifth, and sixth light receiving elements to output signals of three phases A pole sensor having a circuit. 2. A port for detecting the magnetic pole position of a three-phase motor.
A magnetic sensor fixed to the rotating shaft of the motor,
Rotating slipper with slit pattern synchronized with pole position
Disk, which has a first and second annular shape in the radial direction.
Two slit tracks, second, third and fourth, are arranged,
The center angle of each slit track is 360 ° / P (P is the above-mentioned model
The number of magnetic poles of the data
A bright and dark slit pattern is formed and the second slit pattern is formed.
The rack slit pattern is the first slit track
Deviation of 360 ° / P at the central angle with respect to the slit pattern,
The slit pattern of the third slit track is the first slit track.
1 at the central angle with respect to the slit pattern of the lit track
80 ° / P offset, slit slit of 4th slit track
Turn the slit pattern of the first slit track
On the other hand, slit putters for the second and third slit tracks
Rotation deviated from the center by 180 ° / P in the opposite direction
A slit disc and a distance L to the rotary slit disc₁ Located only apart
Between the rotating slit disc and the light source,
Distance L from slit disc₀ Fixed apart only
The optical axis of the light source from the rotary slit disc
Distance r in the direction toward the central axis₀ = K · r₁ (However,
k = (L₁ -L ₀ ) / L₁ , R₁ Is the optical axis of the light source and the front
The distance between the center axes of the rotating slit discs)
On the first straight line that is the heart,
The track radius of the slit track of 2 was multiplied by a constant k
Located at a distance to allow the rays from the light source to pass through and
The first and second slit tracks are made to enter the first track respectively.
1, the second slit window and the first straight line centered on the point
The point on the second straight line that makes an angle of 60 ° / P with the line
The track halves of the third and fourth slit tracks, respectively.
The light from the light source located at a distance obtained by multiplying the diameter by a constant k
3rd and 4th slit tracks through the line respectively
3rd and 4th slit windows to be incident on
, 60 ° in the opposite direction of the first and second straight lines
From the point on the third straight line forming the angle / P
A constant k is applied to the track radii of the third and fourth slit tracks.
It is located at the multiplied distance and allows the rays from the light source to pass through.
And respectively enter the third and fourth slit tracks.
Fixed slit with sixth and fifth slit windows
After passing through the disc and the first window, the optical reflection of the first slit track
Rays reflected by the projectile, after passing through the second window,
The light beam reflected by the light reflecting portion of the slit track, the third
After passing through the window, at the light reflecting part of the third slit track
The reflected ray, after passing through the fourth window, slips into the fourth slit.
Light rays reflected by the light-reflecting portion of the track will pass through the fifth window.
After passing through, it is reflected by the light reflection part of the 4th slit track.
Rays, after passing through the sixth window, the third slit tiger
Light rays reflected by the light reflection part of the
First, second, third, fourth, fifth, sixth converted to air signal
From the first, second, third, fourth, fifth, and sixth light receiving elements.
A signal that processes the applied electrical signal and outputs each of the three-phase signals
Sensor having a signal processing circuit. 3. A port for detecting the magnetic pole position of a three-phase motor.
A magnetic sensor fixed to the rotating shaft of the motor,
Rotating slipper with slit pattern synchronized with pole position
Disk, which has a first and second annular shape in the radial direction.
Two slit tracks, second, third and fourth, are arranged,
The center angle of each slit track is 360 ° / P (P is the above-mentioned model
The number of magnetic poles of the data
A bright and dark slit pattern is formed and the second slit pattern is formed.
The rack slit pattern is the first slit track
Deviation of 360 ° / P at the central angle with respect to the slit pattern,
The slit pattern of the third slit track is the first slit track.
1 at the central angle with respect to the slit pattern of the lit track
80 ° / P offset, slit slit of 4th slit track
Turn the slit pattern of the first slit track
On the other hand, slit putters for the second and third slit tracks
Rotation deviated from the center by 180 ° / P in the opposite direction
A slit disc and a distance L to the rotary slit disc₁ Located only apart
Between the rotating slit disc and the light source,
Distance L from slit disc₀ Fixed apart only
The optical axis of the light source from the rotary slit disc
Distance r in the direction toward the central axis₀ = K · r₁ (However,
k = (L₁ + L ₀ ) / L₁ , R₁ Is the optical axis of the light source and the front
The distance between the center axes of the rotating slit discs)
On the first straight line that is the heart,
The track radius of the slit track of 2 was multiplied by a constant k
First and second slit tracks located at a distance, respectively
The light from the light source reflected by the light reflection part of
The first and second slit windows and the first point
On a second straight line that makes an angle of 60 ° / P with the straight line of
Tracks of the third and fourth slit tracks
Located at a distance obtained by multiplying the radius by a constant k, and
3、4 Before reflected by the light reflection part of the 4th slit track
Third and fourth slit windows for passing light from the light source
And the first straight line and the second straight line centering on the point
In front of the third straight line that makes an angle of 60 ° / P in the opposite direction
Trajectories of the third and fourth slit tracks from the notation
Position at a distance equal to
3、4 Before reflected by the light reflection part of the 4th slit track
The sixth and fifth slit windows that pass the light from the light source are
After being reflected by the formed fixed slit disk and the light reflecting portion of the first slit rack,
Of light that has passed through the window of the second reflection of light from the second slit track
Rays that have passed through the second window after being reflected by
After being reflected by the light-reflecting part of the lit truck, open the third window
The passing light beam is reflected at the light reflection part of the fourth slit track.
Rays that have passed through the fourth window after being projected, the fourth slit
After being reflected by the light reflector of the truck, it passes through the fifth window
Light rays are reflected by the light reflecting portion of the third slit track.
Then, each of the light rays that have passed through the sixth window is received and
First, second, third, fourth, fifth, sixth converted into a signal
Output from the light receiving element and the first, second, third, fourth, fifth, and sixth light receiving elements.
A signal that processes the applied electrical signal and outputs each of the three-phase signals
Sensor having a signal processing circuit. 4. The first, second, and third circuits for converting the currents output from the first, second, third, fourth, fifth, and sixth light receiving elements into voltages by the signal processing circuit, respectively. , Fourth, fifth, and sixth current / voltage conversion circuits, a first differential amplification circuit that differentially amplifies output voltages of the first and second current / voltage conversion circuits, and third and fourth A second differential amplifier circuit that differentially amplifies the output voltage of the current / voltage conversion circuit of
And a third differential amplifier circuit that differentially amplifies the output voltage of the sixth current / voltage conversion circuit, and compares the output voltages of the first, second, and third differential amplifier circuits with a predetermined reference voltage, respectively. The pole sensor according to any one of claims 1 to 3, further comprising first, second, and third comparators.