US 5,289,088 A · DC linear motor

A DC linear motor, comprising:

a stator;
a movable part movable relative to said stator in a first direction, a first distance representing a distance between a reference position of said movable part and a present position thereof;
position/speed detecting means, coupled to said stator and said movable part, for detecting a position and a speed of said movable part;
and
a connector, coupled to said movable part, said position/speed detecting means, and external control means, which supplies the external control means with an output of said position/speed detecting means so that the external control means can control a driving of said movable part based on the output of said position/speed detecting means, wherein said position/speed detecting means includes:
a sensor target fixed on said stator;
and
a displacement sensor, coupled to and movable with, said movable part, for detecting a second distance between the displacement sensor and the sensor target opposite to the displacement sensor, the sensor target having a shape such that the first distance and the second distance have a one-to-one function relationship to each other, said sensor target arranged such that said second distance changes in a second direction which is substantially perpendicular to the first direction as said movable part moves in the first direction.

5 more elements

An image scanner comprising:

a light source for projecting a divergent light onto an image on a document;
reading means for reading a reflected light reflected from the image on the document;
a DC linear motor which carries said light source and said reading means so that the image on the document can be read by said reading means;
and
control means, coupled to said DC linear motor, for controlling a driving of said DC linear motor, wherein said DC linear motor includes:
a stator;
a movable part coupled to said light source and said reading means, the movable part being movable relative to the stator in a first direction, a first distance representing a distance between a reference position of the movable part and a present position thereof;
and
position/speed detecting means, coupled to the stator and the movable part, for detecting a position and a speed of the movable part, the position/speed detecting means including:
a sensor target fixed on the stator;
and
a displacement sensor, coupled to and movable with the movable part, for detecting a second distance between the displacement sensor and the sensor target opposite to the displacement sensor, the sensor target opposite to the displacement sensor, the sensor target being oriented such that as the movable part moves in the first direction, the second distance changes in a second direction which is substantially perpendicular to the first direction, and the sensor target having a shape such that the first distance and the second distance have a one-to-one function relationship to each other, and
wherein said control means includes:
digitalizing means, coupled to the position/speed detecting means of said DC linear motor, for receiving and digitalizing an output of the displacement sensor of the position/speed detecting means of said DC linear motor;
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the digitalizing means, for receiving the output of the position/speed detecting means digitalized by the digitalizing means so as to generate position/speed data corresponding to the position and the speed of the movable part;
and
driving-control means, coupled to the movable part of said DC linear motor, the command generating means and the data-processor means, for receiving the predetermined command from the command generating means and the position/speed data from the data-processor means, to control the driving of the movable part.

15 more elements

A disk storage apparatus, comprising:

a head for recording information on a disk and reproducing information therefrom;
disk rotating means for rotating on the disk;
a DC linear motor, coupled to said head, which moves said head in an approximately radial direction of the disk;
and
control means, coupled to said DC linear motor, for controlling a driving of said IC linear motor, wherein said DC linear motor includes:
a stator;
a movable part coupled to said head, the movable part being movable relative to the stator in a first direction, a first distance representing a distance between a reference position of the movable part and a present position thereof;
and
position/speed detecting means, coupled to the stator and the movable part, for detecting a position and a speed of the movable part, the position/speed detecting means including:
a sensor target, fixed on the stator;
and
a displacement sensor, coupled to and movable with the movable part, for detecting a second distance between the displacement sensor and the sensor target opposite to the displacement sensor, the sensor target having a shape such that the first distance and the second distance have a one-to-one function relationship to each other, the sensor target arranged such that the second distance changes in a second direction which is substantially perpendicular to the first direction as said movable part moves in the second direction, and
wherein said control means includes:
digitalizing means, coupled to the position/speed detecting means of said DC linear motor, for receiving and digitalizing an output of the displacement sensor of the position/speed detecting means;
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the digitalizing means, for receiving the output of the position/speed detecting means digitalized by the digitalizing means so as to generate position/speed data corresponding to the position and the speed of the movable part;
and
driving-control means, coupled to the movable part of said DC linear motor, the command generating means, and the data-processor means, for receiving the predetermined command from the command generating means and the position/speed data from the data-processor means, so as to control the driving of the movable part.

15 more elements

An image scanner comprising:

a light source for projecting a divergent light on an image on a document;
reading means for reading a reflected light reflected from the image on the document;
a DC linear motor which carries said light source and said reading means so that the image on the document can be read by said reading means, and
control means, coupled to said DC linear motor, for controlling a driving of said IC linear motor, wherein said DC linear motor includes:
a stator;
a movable part coupled to said light source and said reading means, the movable part being movable relative to the stator in a first direction, a first distance representing a distance between a reference position of the movable part and a present position thereof;
and
position/speed detecting means, coupled to the stator and the movable part, for detecting a position and a speed of the movable part, the position/speed detecting means including:
a sensor target, fixed on the stator;
and
a displacement sensor, coupled to and movable with the movable part, for detecting a second distance between the displacement sensor and the sensor target opposite to the displacement sensor, the sensor target having a shape such that the second distance is expressed as a periodic function of the first distance and being oriented such that as the movable part moves in the first direction, the second distance changes in a second direction which is substantially perpendicular to the first direction, and
wherein said control means includes:
digitalizing means, coupled to the position/speed detecting means of said DC linear motor, for receiving and digitalizing an output of the displacement sensor of the position/speed detecting means;
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the digitalizing means, for receiving the output of the position/speed detecting means digitalized by the digitalizing means so as to generate position/speed data corresponding to the position and the speed of the movable part;
and
driving-control means, coupled to the movable part of said DC linear motor, the command generating means, and the data-processor means, for receiving the predetermined command from the command generating means and the speed data from the data-processor means, so as to control the driving of the movable part of said DC linear motor.

14 more elements

A disk storage comprising:

a head for recording information on a disk and reproducing information therefrom;
disk rotating means for rotating the disk;
a DC linear motor, coupled to said head, which moves said head in an approximately radial direction of the disk;
and
control means, coupled to said DC linear motor, for controlling a driving of said DC linear motor, wherein said DC linear motor includes:
a stator;
a movable part coupled to said head, the movable part being movable relative to the stator in a first direction, a first distance representing a distance between a reference position of the movable part and a present position thereof;
and
position/speed detecting means, coupled to the stator and the movable part, for detecting a position and a speed of the movable part, the position/speed detecting means including:
a sensor target, fixed on the stator;
and
a displacement sensor, coupled to and movable with the movable part, for detecting a second distance between the displacement sensor and the sensor target opposite to the displacement sensor, the sensor target having a shape such that the second distance is expressed as a periodic function of the first distance and being oriented such that as the movable part moves in the first direction, the second distance changes in a second direction which is substantially perpendicular to the first direction, and
wherein said control means includes:
digitalizing means, coupled to the position/speed detecting means of said DC linear motor, for receiving and digitalizing an output of the displacement sensor of the position/speed detecting means of said DC linear motor;
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the digitalizing means, for receiving the output of the position/speed detecting means digitalized by the digitalizing means so as to generate position/speed data corresponding to the position and the speed of the movable part;
and
driving-control means, coupled to the movable part of said DC linear motor, the command generating means, and the data-processor means, for receiving the predetermined command from the command generating means and the position/speed data from the data-processor means, so as to control the driving of the movable part of said DC linear motor.

15 more elements

An image scanner comprising:

a light source for projecting a divergent light on an image on a document;
reading means for reading a reflected light reflected from the image on the document;
a DC linear motor which carries said light source and said reading means so that the image on the document can be read by said reading means, and
control means, coupled to said DC linear motor, for controlling a driving of said DC linear motor, wherein said DC linear motor includes:
a stator;
a movable part, coupled to said light source and said reading means, which movable part is movable relative to the stator;
and
position/speed detecting means, coupled to the stator and the movable part, for detecting a position and a speed of the movable part, the position/speed detecting means including:
a sensor target, fixed on the stator, which comprises a sensitive part and a non-sensitive part;
and
an area sensor, coupled to and movable with said movable part, for detecting a minute area of the sensitive part of the sensor target opposite to the area sensor, the sensitive part and the non-sensitive part being arranged so that the minute area of the sensitive part detected by the area sensor changes periodically as said movable part moves, and
wherein said control means includes:
digitalizing means, coupled to the position/speed detecting means of said DC linear motor, for receiving and digitalizing an output of the displacement sensor of the position/speed detecting means of said DC linear motor;
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the digitalizing means, for receiving the output of the position/speed detecting means digitalized by the digitalizing means so as to generate position/speed data corresponding to the position and the speed of the movable part;
and
driving-control means, coupled to the movable part of said DC linear motor, the command generating means, and the data-processor means, for receiving the predetermined command from the command generating means and the position/speed data from the data-processor means, to control the driving of the movable part.

14 more elements

A disk storage comprising:

a head for recording information on a disk and reproducing information therefrom;
disk rotating means for rotating the disk;
a DC linear motor, coupled to said head, which moves said head in an approximately radial direction of the disk;
and
control means, coupled to said DC linear motor, for controlling a driving of said DC linear motor, wherein said DC linear motor includes:
a stator;
a movable part coupled to said head, the movable part being movable relative to the stator;
and
position/speed detecting means, coupled to the stator and the movable part, for detecting a position and a speed of the movable part, the position/speed detecting means including:
a sensor target, fixed on the stator, which comprises a sensitive part and a non-sensitive part;
and
an area sensor, coupled to and movable with said movable part, for sensing a minute area of the sensitive part of the sensor target opposite to the area sensor, the sensitive part and the non-sensitive part being arranged so that the minute area of the sensitive part detected by the area sensor changes periodically as said movable part moves, and
wherein said control means includes:
digitalizing means, coupled to the position/speed detecting means of said DC linear motor, for receiving and digitalizing an output of the displacement sensor of the position/speed detecting means of said DC linear motor;
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the digitalizing means, for receiving the output of the position/speed detecting means digitalized by the digitalizing means so as to generate position/speed data corresponding to the position and the speed of the movable part;
and
driving-control means, coupled to the movable part of said DC linear motor, the command generating means, and the data-processor means, for receiving the predetermined command from the command generating means and the speed data from the data-processor means, to control the driving of the movable part of said DC linear motor.

15 more elements

An image scanner comprising:

a light source for projecting a divergent light on an image on a document;
reading means for reading a reflected light reflected from the image on the document;
a DC linear motor which carries said light source and said reading means so that the image on the document can be read by said reading means, and
control means, coupled to said DC linear motor, for controlling a driving of said DC linear motor, wherein said DC linear motor includes:
a stator including a permanent magnet having a plurality of N-poles and S-poles;
and
a movable part, coupled to said light source and said reading means, the movable part being movable relative to the stator, the plurality of N-poles and S-poles of the permanent magnet being alternately aligned along a direction of motion of the movable part, the movable part including:
a coil opposite to the permanent magnet of the stator, the magnetic field of the permanent magnet penetrating the coil, and the movable part moving when the coil is electrified, and
a Hall effect element which detects the magnetic field penetrating the coil, and
wherein said control means includes:
digitalizing means, coupled to the Hall effect element of the movable part, for receiving and digitalizing an output of the Hall effect element, said digitalizing means including a waveform shaper which performs a waveform shaping on the output of the Hall effect element of the movable part;
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the digitalizing means, for receiving the output of the Hall effect element of the movable part digitalized by the digitalizing means so as to generate position/speed data corresponding to the position and a speed of the movable part;
and
driving-control means, coupled to the Hall effect element, the coil of the movable part, the command generating means and the data-processor means, for receiving the predetermined command from the command generating means and the position/speed data from the data-processor means, so as to control the driving of the movable part of said DC linear motor.

12 more elements

An disk storage comprising:

a head for recording information on a disk and reproducing information therefrom;
disk rotating means for rotating the disk;
a DC linear motor, coupled to said head, which moves said head in an approximately radial direction of the disk;
and
control means, coupled to said DC linear motor, for controlling a driving of said DC linear motor, wherein said DC linear motor includes:
a stator including a permanent magnet having a plurality of N-poles and S-poles;
and
a movable part, coupled to said head, the movable part being movable relative to the stator, the plurality of N-poles and S-poles of the permanent magnet being alternately aligned along a direction of motion of the movable part, the movable part including:
a coil opposite to the permanent magnet of the stator, the magnetic field of the permanent magnet penetrating the coil, and the movable part moving when the coil is electrified;
and
a Hall effect element which detects the magnetic field penetrating the coil, and
wherein said control means includes:
digitalizing means, coupled to the Hall effect element of the movable part, for receiving and digitalizing an output of the Hall effect elements, said digitalizing means including a waveform shaper which performs a waveform shaping on the output of the Hall effect element of the movable part;
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the digitalizing means, for receiving the output of the Hall effect element of the movable part digitalized by the digitalizing means so as to generate position/speed data corresponding to the position and a speed of the movable part;
and
driving-control means, coupled to the Hall effect element and the coil of movable part, the command generating means and the data-processor means, for receiving the predetermined command from the command generating means and the speed data from the data-processor means, so as to control the driving of the movable part of said DC linear motor.

14 more elements

An image scanner comprising:

a light source for projecting a divergent beam on an image on a document;
reading means for reading a reflected light reflected from the image on the document;
a DC linear motor which carries said light source and said reading means so that the image on the document can be read by said reading means, and
control means, coupled to said DC linear motor, for controlling a driving of said DC linear motor, wherein said DC linear motor includes:
a stator including a permanent magnet having a plurality of N-poles and S-poles;
and
a movable part coupled to said light source and said reading means, the movable part being movable relative to the stator, the plurality of N-poles and S-poles of the permanent magnet being alternately aligned along a direction of motion of the movable part, the movable part including a coil opposite to the permanent magnet of the stator, the magnetic field of the permanent magnet penetrating the coil, and the movable part moving when the coil is electrified;
position/speed detecting means, coupled to said stator and said movable part, for detecting a position and a speed of said movable part;
and
temperature detecting means, coupled to said movable part, for detecting a temperature of the coil of the movable part;
and
wherein said control means includes:
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the position/speed detecting means and the temperature detecting means, for processing an output of the position/speed detecting means and an output of the position/speed detecting means so as to calculate a control voltage V to be applied to the coil as follows:
V'=RI+K(Rv-v),
, where R represents the resistance of the coil at tC..degree. and is defined as R=R.sub.0 (1+0.0043t) (-200<t<+150), R.sub.0 represents the resistance of the coil at 0.degree. C., I represents a driving current, K represents a proportional gain, Rv represents a target speed of the movable part, and v represents a present speed of the movable part;
and
driving-control means, coupled to the movable part of said DC linear motor, the command generating means, and the data-processor means, for controlling the driving of the movable part based on the predetermined command generated by the command generating means and the control voltage calculated by the data-processor means.

15 more elements

A disk storage comprising:

a head for recording information on a disk and reproducing information therefrom;
disk rotating means for rotating the disk;
a DC linear motor, coupled to said head, which moves said head in an approximately radial direction of the disk;
and
control means, coupled to said DC linear motor, for controlling a driving of said DC linear motor, wherein said DC linear motor includes:
a stator including a permanent magnet having a plurality of N-poles and S-poles;
and
a movable part coupled to said light source and said reading means, the movable part being movable relative to the stator, the plurality of N-poles and S-poles of the permanent magnet being alternately aligned along a direction of motion of the movable part, the movable part including a coil opposite to the permanent magnet of the stator, the magnetic field of the permanent magnet penetrating the coil, and the movable part moving when the coil is electrified;
position/speed detecting means, coupled to said stator and said movable part, for detecting a position and a speed of said movable part;
and
temperature detecting means, coupled to said movable part, for detecting a temperature of the coil of the movable part;
and
wherein said control means includes:
command generating means for generating a predetermined command which controls the driving of the movable part of said DC linear motor;
data-processor means, coupled to the position/speed detecting means and the temperature detecting means, for processing an output of the position/speed detecting means and an output of the position/speed detecting means so as to calculate a control voltage V to be applied to the coil as follows:
V'=RI+K(Rv-v),
, where R represents the resistance of the coil at tC..degree. and is defined as R=R.sub.0 (1+0.0043t) (-200<t<+150), R.sub.0 represents the resistance of the coil at 0.degree. C., I represents a driving current, K represents a proportional gain, Rv represents a target speed of the movable part, and v represents a present speed of the movable part;
and
driving-control means, coupled to the movable part of said DC linear motor, the command generating means, and the data-processor means, for controlling the driving of the movable part based on the predetermined command generated by the command generating means and the control voltage calculated by the data-processor means.

16 more elements

DC linear motor

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DC linear motor

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Abstract

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