JP3173315B2 - Drives and cameras and optical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for driving a driven body such as a lens in an optical apparatus such as a still camera and a video camera.

[0002]

2. Description of the Related Art For example, a driving device used for driving a lens at the time of auto-focusing of a video camera requires a high-speed driving, a large thrust, a low vibration and a low noise. And high control accuracy are required.

[0003] As a conventional driving device of this type, (A) a lead screw is provided on an output shaft of a stepping motor, and a rack screw is provided on a focus lens barrel or a variable power lens barrel which is a driven body. By engaging the screw with the rack screw, the rotation of the stepping motor moves the driven lens, such as the focus lens barrel or the variable power lens barrel, in the optical axis direction, and counts the number of stepping steps of the stepping motor. Is performed in the optical axis direction by a necessary amount. (B) It is necessary to amplify the driving force of the motor by the deceleration mechanism, rotate the lens barrel provided with the cam, move the lens barrel in the optical axis direction by this cam, and count the output pulses of the pulse encoder. It is performed to move by an appropriate amount in the optical axis direction. (C) The lens barrel, which is the driven body, is moved in the optical axis direction by the voice coil motor, and the movement position of the lens is detected by the magnetoresistive element.

[0004]

As described above, there are various driving devices in the related art. However, since the driving device of (A) uses a stepping motor as a driving power source, a lens as a driven body can be quickly driven. Attempting to drive the stepping motor causes the stepping motor to lose synchronism, and the position of the lens with respect to the input pulse cannot be determined.

In order to drive the driven lens at a high speed, a large amount of electric power is required, and a large and powerful motor is required. As a result, the size of the entire apparatus is increased. In the case of using a stepping motor as the driving power source, vibration occurs because the lens is driven by the step operation, and the vibration directly vibrates the microphone to generate noise, which is recorded on a video tape by a video camera via the microphone. There was a problem that would be done.

Further, in the driving device shown in FIG. 1B, since the deceleration mechanism is used to drive the lens barrel as the driven body at a high speed, the rotation speed of the motor as the driving source must be increased. Eventually, noise is generated, and the noise is recorded on a videotape by a video camera via a microphone.

[0007] Although the drive device of (C) is a so-called direct drive, the problem of noise can be solved, but the moving weight is the weight of the lens barrel which is the driven body and the weight of the movable portion of the voice coil motor. Is added. As a result,
As compared to the thrust required to move the lens, a stronger thrust is required, and there is a problem that the voice coil motor must be large and a large amount of power is required.

[0008] Further, for example, in order to compensate for the defocus caused when the lens is used in a high temperature environment or a low temperature environment by varying the driving position and the driving stroke amount of the driven body, any of the conventional apparatuses is required. However, since it is controlled by the relative position, for example, the temperature of the lens is measured, the result is processed by the microcomputer, and the driven body is controlled to the position in consideration of the correction amount, which is a rather large scale. A correction system is required, and there is a problem that an apparatus equipped with the correction system becomes expensive, large, and consumes a large amount of power.

It is an object of the present invention to provide a driving device, a camera, and an optical device which can easily control the position of a driven body (lens barrel).

[0010]

According to a first aspect of the present invention, there is provided a driving device which is provided so as to be movable in a rectilinear direction and has a sliding groove for driving, and moves the driven member in the rectilinear direction. A guide means for guiding freely, a permanent magnet magnetized to two poles and having a rotation center, a sliding shaft fitted at one end to the sliding groove of the driven body, and a rotation shaft of the permanent magnet at the other end. A rotor having an arm integrally formed with a fixed rotating shaft, a rotor rotated by a driving power source, and a rotation angle detecting means for detecting a rotation angle of the rotor and outputting a signal proportional to a magnetic flux density of the permanent magnet And control means for controlling the rotation of the rotor by driving the drive power source based on a control command signal relating to a target position of the driven body and an output signal of the rotation angle detection hand throw, Rotation of the rotor The mounting direction of the arm is adjusted so that the degree and the output signal of the rotation angle detection means have a substantially linear relationship, and the rotation angle of the rotor and the position of the driven body have a substantially linear relationship. The rotation angle detecting means is provided at a position opposed to the boundary between the magnetic poles of the permanent magnet when the arm is at an angle perpendicular to the direction of the straight movement so as to coincide with the boundary between the magnetic poles of the permanent magnet. .

According to a second aspect of the present invention, in the first aspect, the rotation angle θ of the rotor and the position X of the driven body are set.
X = R sin θ (R is a constant), and the output e out of the rotational position detecting means is expressed by the following relation with respect to the rotational angle θ of the rotor: e out = B sin ⁿ θ (n = 1,2; B = (Constant).

According to a third aspect of the present invention, in the first aspect of the invention, the driven body is a lens barrel.

A camera according to a fourth aspect of the present invention is characterized in that the lens is moved by using the driving device according to the first, second or third aspect.

An optical apparatus according to a fifth aspect of the present invention is the optical apparatus according to the first or second aspect.
Alternatively, the lens is moved by using the third driving device.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory diagram of a main part in which the driving device of the present invention is applied to a zoom lens used for a video camera or the like.

In FIG. 1, 1 is a permanent magnet, 2 is a first stator, 3 is a second stator, 4 is a coil, 5 is an arm which is a component of power conversion means, 6 is a rotating shaft, 7
Is a sliding shaft, 8 is a lens barrel which is a driven body, 9 and 10 are first and second guide bars which are guide means, 11 is a photographing lens which is a moving body, and 12 is a rotational position detecting means. Hall element, 13 is an amplifier circuit (first control means), 14 is a control circuit (second control means), 15 is a drive circuit,
6 is a fixed lens barrel for holding the first and second guide bars, 17
Is a spring, 18 is a motor, and 19 is a rotor formed by the permanent magnet 1, the arm 5, the rotating shaft 6, and the sliding shaft 7.

The permanent magnet 1 is formed by molding a neodymium-based plastic permanent magnet into a cylindrical shape, for example, and its outer diameter is magnetized to two poles, and its magnetized waveform is sinusoidal. . The two-pole sine-wave magnetized waveform can be obtained by making the inner diameter smaller than the outer diameter of the permanent magnet and magnetizing it in a parallel magnetic field.

The first stator 2 is made, for example, by stamping and laminating a silicon steel plate by press working, and
And a magnetic pole portion 2a and an extension portion 2b opposed to each other.

The second stator 3 is formed, for example, by punching and laminating a silicon steel plate by plus processing, and
And a magnetic pole portion 3a opposed to.

The coil 4 is formed by winding a copper wire around a hollow bobbin (not shown), and the extension portion 2 of the first stator 2 is formed.
b. The arm 5 is made by molding, for example, a polycarbonate resin, and a rotating shaft 6 and a sliding shaft 7 are provided integrally, and the permanent magnet 1 is fixed to the rotating shaft 6. The rotating shaft 6 is rotatably supported by a bearing of a case (not shown). Then, the above-mentioned first stator 2, second stator 3, coil 4, rotor 1
Reference numeral 9 denotes a motor (drive power source) 18.

The lens barrel 8 is formed by molding, for example, a polycarbonate resin, and has a first sliding groove 8a and a sliding hole 8a.
b, a second sliding groove 8c, and a spring locking portion 8d are provided, and the taking lens 11 is fixed. The sliding shaft 7 is fitted into the first sliding groove 8a of the lens barrel 8, and the spring locking portion 8
A tracking spring 17 is fixed to the sliding shaft 7 d.
Is urged to abut the side surface of the sliding groove 8a of the lens barrel 8. The tracing spring 17 is made, for example, by pressing phosphor bronze.

The first guide bar 9 is made of, for example, stainless steel, and is arranged in parallel with the optical axis direction of the taking lens 11. Both ends of the first guide bar 9 are press-fitted into the fixed lens barrel 16 by known means. Fixed. The first guide bar 9 is fitted in the sliding hole 8b of the lens barrel 8, and supports the lens barrel 8 movably in the length direction of the first guide bar.

The second guide bar 10 is made of, for example, stainless steel, and is disposed in parallel with the optical axis direction of the taking lens 11, and both ends thereof are fixed to the fixed lens barrel 16 by a known means such as press fitting. Have been. The second guide bar 10 is fitted into the sliding groove 8c of the lens barrel 8,
The lens barrel 8 is movably supported in the length direction of the second guide bar.

The Hall element 12 is a well-known Hall element.
The permanent magnet 1 is fixed to a case (not shown) so as to face the outer peripheral portion of the permanent magnet 1 through a slight gap.
And outputs an output signal proportional to the magnetic flux density on the surface.

The input terminal 13a of the amplifier circuit 13 is connected to the output terminal of the Hall element 12, and amplifies the output signal of the Hall element 12. Further, the amplifier circuit 13 includes a circuit for supplying bias power to the Hall element 12.

The control circuit 14 has a first input terminal 14a,
It has a second input terminal 14b and an output terminal 14c, and the first input terminal 14a is connected to, for example, a focus control circuit (not shown) of a video camera.
In a, a target position of the photographing lens 11 as a moving body is input as a voltage value as a control command signal. The second input terminal 14b is connected to the output terminal 13b of the amplifier circuit 13,
The current position of the photographing lens 11, which is a moving object, is input to the second input terminal 14b as a voltage value. Therefore,
The control circuit 14 amplifies the difference between the voltage corresponding to the target position input to the first input terminal 14a and the voltage corresponding to the current position input to the second input terminal 14b, and amplifies the output terminal 14c. Output to

The drive circuit 15 has an input terminal 15a and first and second output terminals 15b and 15c.
5a is electrically connected to the output terminal 14c of the control circuit 14, and the first and second output terminals 15b and 15c are electrically connected to the coil 4, respectively. In the drive circuit 15, when the voltage value applied to the input terminal 15a is higher than a predetermined voltage, the voltage output to the first output terminal 15b becomes higher than the voltage output to the second output terminal 15c. And the predetermined voltage and the input terminal 15
A voltage proportional to the absolute value of the difference between the voltages input to a is applied to the coil 4 via the first and second output terminals 15b and 15c.

The drive circuit 15 has an input terminal 15a.
Is lower than the predetermined voltage, the voltage output to the first output terminal 15b is lower than the voltage output to the second output terminal 15c, and the predetermined voltage And a voltage proportional to the absolute value of the difference between the voltages input to the input terminal 15a and the input terminal 15a is applied to the coil 4 via the first and second output terminals 15b and 15c. The amplifying circuit 13, the control circuit 14, and the drive circuit 15 constitute control means.

With this configuration, in the present embodiment, when a command signal corresponding to the target position of the lens barrel 8 as a driven body is input to the first input terminal 14a of the control circuit 14 as a voltage, The control circuit 14 amplifies the difference between the output signal of the Hall element 12 and the command signal, and applies a voltage for reducing the difference to zero to the drive circuit 15 to the coil 4 of the meter 18. The rotor 19
The output voltage of the Hall element 12 rotates to a position at which a value corresponding to the command signal is output. At this time, the rotation of the rotor 19 is transmitted to the lens barrel 8 via the arm 5, and the lens barrel 8 moves to a position corresponding to the command signal.

If the movement of the lens barrel 8 does not have linearity with respect to the command signal, it will be difficult to control the position of the lens barrel 8. The position of the lens barrel 8 and the output voltage of the Hall element 12 are given linearity by applying a sinusoidal magnetization and devising the mounting angle of the arm 5 and the Hall element 12 to control the lens barrel 8. Easy going.

Next, the position of the lens barrel 8 and the Hall element 12
The mounting angles of the permanent magnet 1, the arm 5, and the Hall element 12 for making the output voltage of the device have linearity will be described with reference to FIGS.

In the present embodiment shown in FIG. 1, the mounting direction of the arm 5 coincides with the direction of the boundary T between the magnetic poles of the permanent magnet 1. When the arm 5 is at an angle perpendicular to the longitudinal direction of the first and second guide bars 9 and 10, the Hall element 12 forms a boundary T between the magnetic poles of the permanent magnet 1.
Is disposed at a position opposite to the above.

Next, the output signal of the Hall element 12, the rotation angle of the rotor 19, and the position of the lens barrel 8 will be described with reference to FIG. In FIG. 2, θ represents the rotation angle of the rotor 19, and 0 represents the position where the arm 5 is in a direction perpendicular to the length direction of the first and second guide bars 9, 10. Eout represents the output signal of the Hall element 12. Further, x represents the position of the lens barrel 8 as 0 where the arm 5 is in a direction perpendicular to the length direction of the first and second guide bars 9 and 10.

Now, since the permanent magnet 1 is given a sinusoidal magnetization, the output voltage eout of the Hall element 12 with respect to the rotation angle θ of the rotor 19 becomes sinusoidal as shown in FIG. Become. Also, the rotation angle θ of the rotor 19
With respect to the position x of the lens barrel 8 with respect to the above, since the arm 5 for rotation of the sliding shaft 7 becomes equal to the longitudinal component of the first and second guide bars 9 and 10 by the configuration described with reference to FIG. 2 (b).

The output voltage eout of the Hall element 12 and the position x of the lens barrel 8 become sinusoidal with respect to the rotation angle θ of the rotor 19, so that the output of the Hall element 12 with respect to the position x of the lens barrel 8 is obtained. The voltage eout is shown in FIG.
As shown in FIG. 3C, the position becomes a straight line, and the position of the lens barrel 8 can be easily controlled based on the output voltage eout of the Hall element 12.

Next, a specific configuration of the Hall element 12, the amplifier 13, the control circuit 14, and the drive circuit 15 in this embodiment will be described with reference to FIG. In FIG. 3, 21 to 48 are resistors, 49 to 54 are operational amplifiers, and 55 is a capacitor.

The resistor 21 is connected to the first input terminal of the Hall element 12 and the power supply + V, and determines the bias current of the Hall element 12. Since the bias current of the Hall element 12 is a factor that determines the gain of the Hall element, the gain is determined by the resistor 21. Resistance 22, 23, 2
4, 25, 26, 27 and the operational amplifier 49 constitute a well-known differential amplifier circuit, and the first and second input terminals of the differential amplifier circuit are connected to the first and second output terminals of the Hall element 12, respectively. Terminal is connected. The resistors 32 and 33 are for generating a reference voltage.

The resistors 28, 29, 30, 31 and the operational amplifier 50 constitute a well-known differential amplifier circuit 141. The first input terminal 14a of the differential amplifier circuit including the operational amplifier 50 is an input terminal of the driving device according to the present embodiment,
It is connected to an external command signal generator such as an automatic focus detector in a video camera. Further, a second input terminal of the differential amplifier circuit 141 including the operational amplifier 50 is connected to an output terminal of the differential amplifier circuit 141 including the operational amplifier 49, and the differential amplifier circuit 141 including the operational amplifier 50 is externally connected. The difference between the given command signal and the signal obtained by amplifying the output signal of the Hall element 12 corresponding to the rotational position of the rotor 19 is amplified.

Resistors 34, 35, 36, 37, 38, 3
9, 40, 41, capacitor 55, operational amplifiers 52, 5
Reference numeral 3 denotes a speed signal amplifying circuit 142. The input terminal of the speed signal amplifying circuit 142 is
2 is connected to the output terminal of a differential amplifier circuit including an operational amplifier 49 for amplifying the output signal of
Amplifies the change in the output signal of the Hall element 12, which represents the rotation speed of the rotor 19.

The resistors 42, 43, 44, 45 and the operational amplifier 51 constitute a well-known amplifier circuit 151, whose input terminal is the output of the differential amplifier circuit 141 including the operational amplifier 50 which is the first output terminal of the control circuit 14. And a second output terminal of the control circuit 14, which is an output terminal of the speed signal amplifying circuit 142. The amplifying circuit 151 including the operational amplifier 51 outputs a command signal and a voltage corresponding to a reference voltage corresponding to the rotational speed of the rotor 19 in accordance with the displacement of the lens barrel 8.

The resistors 46, 47, 48 and the operational amplifier 54 constitute a well-known inverting amplifier circuit 152, and a first input terminal thereof is connected to an output terminal of the amplifier circuit 151 including the operational amplifier 51. 51, and outputs a voltage obtained by inverting the output voltage of the amplifying circuit 151 including 51. The output terminal of the amplifier circuit 151 including the operational amplifier 51 is the first output terminal 15b of the drive circuit 15, and the inverting amplifier circuit 152 including the operational amplifier 54 at the first terminal of the coil 4.
Output terminal is the second output terminal 15 of the drive circuit 15.
c and is connected to the second terminal of the coil 4. With such a circuit configuration, the driving device according to the present invention can accurately drive the lens barrel 8 as the driven body in response to the command signal.

When the lens barrel 8 is driven by the driving device according to the present invention as in the first embodiment of the present invention described above, the gain of the driving circuit is adjusted by focusing the photographing lens on the focal point. It is desirable to set such that a current enough to drive a load due to the weight of the lens barrel 8 or the like flows through the coil 4 of the motor 18 when the common confusion circle is moved by half or less of the diameter of the circle of confusion. A picture without blur can be obtained.

FIG. 4 is an exploded perspective view of a lens barrel when the present invention is applied to driving a zoom lens of a video camera.
The same parts as those in FIG. In FIG. 4, reference numeral 55 denotes a first fixed lens barrel;
Are fixed. Reference numeral 56 denotes a first movable lens barrel to which a variable power lens is fixed. Reference numeral 57 denotes a second fixed lens barrel to which the second fixed lens group is fixed. 58 and 59 are first and second lenses for a variable power lens.
The first movable lens mirror is fixed to the first and second fixed lens barrels, and is fitted in the sliding holes 56c and the sliding grooves 56d provided in the first movable lens barrel 56. The tube 56 is movably supported in the optical axis direction.

Reference numeral 61 denotes a stepping motor, and a screw shaft 61a is provided on the output shaft. Reference numeral 60 denotes a rack member, and a mounting hole 56 provided in the first movable lens barrel 56.
a, 56b, and a rack screw portion is engaged with the screw shaft 61a of the stepping motor. A reset sensor 62 resets the position of the first movable lens barrel 56. With such a configuration,
The variable power lens moves in the optical axis direction as the stepping motor 61 rotates.

Reference numerals 63 and 64 denote aperture blades, and reference numeral 65 denotes a holding plate for regulating the position of the aperture blades. Reference numeral 66 denotes a motor for driving the aperture, and the aperture springs 63 and 64 open and close according to the rotation thereof. Reference numeral 16 denotes a third fixed lens barrel, and reference numeral 8 denotes a second movable lens barrel to which a focus compensating lens is fixed.

Reference numerals 9 and 10 denote guide bars for the first and second focus compensating lenses, respectively.
And is fitted to the sliding hole 8b and the second sliding groove 8c of the second movable lens barrel 8,
The second movable lens barrel 8 is supported movably in the optical axis direction. Reference numeral 18 denotes a motor, and the third fixed lens barrel 16
The output shaft 7 is fitted in the first sliding groove 8a of the second movable lens barrel 8, and the second movable lens barrel 8 is driven in the optical axis direction by the rotation of the motor 18. .

With the lens barrel having such a configuration, it is possible to perform quiet, high-speed, and accurate lens driving.

(Second Embodiment) In the first embodiment of the present invention, the magnetization waveform of the permanent magnet 1 is sinusoidal, but the reason is that the inner diameter of the permanent magnet is larger than the outer diameter. In some cases, the magnetized waveform of the permanent magnet does not become a sine wave. Even in such a case, the driving device according to the present invention enables accurate position control of the driven body. Next, such a second embodiment according to the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 5 is an enlarged view of a main part of a second embodiment of the present invention. This second embodiment is the same as the first embodiment except for the connection between the driven member and the rotor. Since the configuration is the same, the same portions are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 5, the permanent magnet 1 has a cylindrical shape, and its surface is subjected to so-called trapezoidal wave-like magnetization.
The rotating shaft 6 is rotatably supported by bearings provided in a case (not shown) at small diameter portions at both ends, and the permanent magnet 1 is fixed to a large diameter portion at the center by press fitting or the like. The arm 5 is attached in the boundary direction of the magnetization of the permanent magnet 1, and a fitting shaft 7 is provided at a tip portion thereof.

The rotating shaft 6, the arm 5, and the fitting shaft 7 are integrally formed by plastic molding, and form a rotor 19 as a rotating body together with the permanent magnet 1.

Reference numeral 8 denotes a lens barrel which is a driven body, to which a photographing lens 11 is fixed. The lens barrel 8 is supported movably in the optical axis direction by fitting the slide hole 8b with the guide bar 9. The lens barrel 8 is provided with a curved first sliding groove 8e, and the curved shape of the first sliding groove 8e is such that the arm 5 has a rotor 19 at right angles to the guide bar 9. The shape of the lens barrel 8 is such that the position of the lens barrel 8 becomes a straight line when the rotor 19 rotates with the rotation position as the origin. That is, the curved shape of the first sliding groove 8e is such that the position x of the lens barrel 8 becomes x = A × θ (A is an arbitrary constant) with respect to the rotation angle θ of the rotor 19. ing. The Hall element 12 is connected to the arm 5
Is perpendicular to the guide bar 9 and opposes the permanent magnet 1 via a slight gap at a position opposing the boundary T of the magnetic poles of the permanent magnet 1. The follower spring 17 has one end fixed to the spring locking portion 8 d of the lens barrel 8 and the other end biasing the fitting shaft 7 so as to contact the first sliding groove 8 e of the lens barrel 8. I have.

Next, the operation of the second embodiment having such a configuration will be described with reference to FIGS. 6 (a), 6 (b) and 6 (c). FIG.
Where θ is the rotor 19 when the rotation position of the rotor 19 at which the arm 5 is perpendicular to the guide bar 9 is taken as the origin.
Is the rotation angle eout of the Hall element 1 output when the boundary T of the magnetic pole of the permanent magnet 1 and the Hall element 12 face each other.
The output voltage 2 and x represent the position of the lens barrel 8 when the rotation position of the rotor 19 in which the arm 5 is perpendicular to the guide bar 9 is set as the origin.

Since the magnetic flux density of the outer peripheral portion of the permanent magnet 1 forms a trapezoidal wave with respect to the angle as described above, the output voltage e of the Hall element 12 with respect to the rotation angle θ of the rotor 19 is obtained.
out is a straight line as shown in FIG. The position x of the lens barrel 8 is such that the sliding groove 8e of the lens barrel 8 has a shape that moves the lens barrel 8 linearly with respect to the rotation angle of the rotor 19 as described above. As shown in FIG. 6B, a straight line is formed with respect to the rotation angle θ of the rotor 19. Since the output voltage eout of the Hall element 12 and the position x of the lens barrel 8 are each linear with respect to the rotation angle θ of the rotor 19, the output voltage eout of the Hall element 12 with respect to the position x of the lens barrel 8 is also linear. Become. That is, the output voltage e of the Hall element 12 in proportion to the position x of the lens barrel 8
out can be obtained, and the position of the lens barrel, which is the driven body, can be easily controlled. According to the second embodiment having such a configuration, accurate position control is possible regardless of the magnetization waveform of the permanent magnet 1.

[0055]

As described above, according to the driving device of the present invention, the driven body can be driven at high speed and quietly, and the rotational position of the rotor is set to the position of the driven body and the primary position. Therefore, there is an effect that accurate position control can be easily performed.

Since the lens is moved by the driving device of the present invention, there is an effect that a camera with high speed, quietness, and high accuracy can be obtained.

Since the lens is moved by the driving device of the present invention, there is an effect that a high-speed, quiet, and high-precision optical device can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a first example of the present invention.

FIG. 2 is an explanatory diagram illustrating an output signal of a rotational position detecting unit and a position of a driven body according to the first embodiment of the present invention.

FIG. 3 is a drive circuit diagram according to the first embodiment of the present invention.

FIG. 4 is an exploded perspective view of a lens barrel to which the first embodiment of the present invention is applied.

FIG. 5 is an explanatory view of a main part of a second embodiment of the present invention.

FIG. 6 is an explanatory diagram illustrating an output signal of a rotational position detecting unit and a position of a driven body according to a second embodiment of the present invention.

[Explanation of symbols]

 5 Arm (power conversion means) 8 Lens barrel (driven body) 12 Hall element (rotational position detection means) 13 Amplification circuit (first control means) 14 Control circuit (second control means) 19 Rotor (rotary body) )

Continuation of the front page (56) References JP-A-5-27150 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B ^7/ 04-7/08

Claims (5)

(57) [Claims] 1. A driving device which is provided so as to be movable in a straight traveling direction.
A driven body having a sliding groove, and a guide for movably guiding the driven body in the linear direction.
And id means, a permanent magnet having a rotation center is magnetized in two poles, prior to one end
The driven shaft has a sliding shaft fitted into the sliding groove and the other end provided with the sliding shaft.
The rotating shaft fixed to the center of rotation of the permanent magnet is integrally formed
Arm that is rotated by a driving power source.
Flux density of the permanent magnet to detect a coater, the rotation angle of the rotor
A rotation angle detecting means for outputting a signal proportional to the rotation angle, a control command signal relating to a target position of the driven body, and the rotation angle detection means.
The drive power source based on the output signal of the turning angle detection hand throw
Control the rotation of the rotor by driving
Control means for controlling the rotation angle of the rotor and the output of the rotation angle detection means.
Signal and a substantially linear relationship, the rotation angle of the rotor
So that the degree and the position of the driven body have a substantially linear relationship.
In addition, the mounting direction of the arm is
The arm coincides with the boundary and the rotation angle detecting means is
When the permanent magnet is at an angle perpendicular to the straight traveling direction,
A driving device provided at a position facing a boundary between the magnetic poles . 2. The rotation angle θ of the rotor and the position X of the driven body have a relationship of X = Rsin θ (R is a constant), and the output e out of the rotation position detecting means is the rotation angle of the rotor. 2. The driving device according to claim 1, wherein e out = B sin ⁿ .theta. (n = 1, 2; B = constant) with respect to .theta .. 3. The driving device according to claim 1, wherein the driven body is a lens barrel. 4. A camera for moving a lens using the driving device according to claim 1. 5. An optical apparatus characterized in that a lens is moved by using the driving device according to claim 1.