JP2000028894A - Driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drive plural bodies to be driven and to accurately detect the positions of the bodies to be driven by fixing one scale member in a device main body and providing each of the bodies to be driven with a sensor to be opposed to the scale member. SOLUTION: Projections 26a and 26b having a groove in which a guide shaft 13 passes are formed in the center of the lower parts of lens frames 21a and 21b. The upper surfaces of the grooves of the projections 26a and 26b are formed level, and the ends of flexible printed circuit boards 20a and 20b where MR sensors 14a and 14b are fixed are stuck to the upper surfaces thereof so that the detecting surfaces of the sensors 14a and 14b may face downward. In the driving device 1, the magnetized surface of the shaft 13 is used also as the scale in order to detect the positions of lenses L1 and L2, and positional deviation is not caused between the scale read by the sensor 14a and the scale read by the sensor 14b. Since one scale member is prepared and the shaft 13 is used also as the scale member, the utilization efficiency of space is high.

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 individually driving a plurality of driven members in the same direction or in opposite directions to individually detect the positions of the driven members.

[0002]

2. Description of the Related Art A driving device for driving a driven body to move it to an arbitrary position is provided with a scale member whose relative position changes by driving and a sensor for reading the scale, and the number of scales read by the sensor. In some cases, the position of the driven body is detected based on the following. One of the scale member and the sensor is fixed to the apparatus main body, and the other is attached to the driven body and moves together with the driven body. The detection of the position by the scale member and the sensor is performed optically or based on other physical properties.

FIG. 9 shows an example of such a driving device. The driving device 5 drives the lens L, and includes a piezoelectric actuator 71, a driving shaft 72, a guide shaft 73, and a support wall 7.
4, 75, a magnetized plate 76 as a scale member, and a magnetic resistance (MR) sensor 77. The piezoelectric actuator 71 has a fixed rear end surface, and expands and contracts in the front-rear direction according to the applied voltage. The drive shaft 72 has a rear end fixed to the front end surface of the piezoelectric actuator 71, and is displaced in the axial direction as the piezoelectric actuator 71 expands and contracts.

The drive shaft 72 is slidably supported by support walls 74 and 75, and the guide shaft 73 is disposed in parallel with the drive shaft 72 and is fixed to the support walls 74 and 75. The lens L is held by a lens frame 81. Lens frame 81
A protrusion 82 having a through hole that slides on the outer peripheral surface of the drive shaft 72 is provided at an upper part of the drive shaft 72, and a protrusion 83 having a groove through which the guide shaft 73 passes is provided at a lower part. Guide shaft 7
Reference numeral 3 slides on the side surface of the groove of the projection 83 to restrict the rotation of the lens frame 81 around the drive shaft 72.

FIG. 10 shows an example of a voltage applied to the piezoelectric actuator 71. When the applied voltage changes rapidly, the piezoelectric actuator 71 expands or contracts rapidly, and when the applied voltage changes gradually, the piezoelectric actuator 71 expands or contracts gradually. The lens frame 81, which is only in sliding contact with the drive shaft 72, slides on the drive shaft 72.
If the displacement of the drive shaft 72 is low, the displacement cannot follow the displacement. If the displacement of the drive shaft 72 is high, the drive shaft 72 remains at the original position.

Therefore, the lens L can be driven in one direction by repeatedly increasing and gradually decreasing the voltage applied to the piezoelectric actuator 71 as shown in FIG. 10A, and conversely. 10B, the lens L can be driven in the opposite direction by repeating a gradual rise and a rapid fall as shown in FIG. The driving speed of the lens L can be adjusted by the magnitude and cycle of the applied voltage.

The magnetized plate 76 is attached to the projection 82 of the lens frame 81 in parallel with the drive shaft 72, and has a large number of N poles and S poles on its surface at a predetermined pitch in the direction along the drive shaft 72. Are alternately magnetized. The MR sensor 77 changes its electric resistance value in accordance with the magnetic field of the environment. The MR sensor 77 is fixed to a leaf spring 78 screwed to the support wall 75 and is arranged to face the magnetized surface of the magnetized plate 76. . Although not shown, a spacer having a uniform thickness is adhered to the surface of the MR sensor 77, and the MR sensor 77 is lightly pressed against the magnetized plate 76 by the urging force of the leaf spring 78, and the surface is magnetized. It is kept at a fixed distance from the magnetized surface of the plate 76.

When the drive shaft 72 vibrates due to expansion and contraction of the piezoelectric actuator 71 and the lens frame 81 moves, the magnetized plate 7
6 also moves, and the magnetic field around the fixed MR sensor 77 changes periodically. Therefore, the output of the MR sensor 77 also changes periodically, and the drive amount of the lens L is calculated from the number of changes in the output of the MR sensor 77 and the magnetization pitches of the N and S poles of the magnetizing plate 76. The position of the lens L is obtained by integrating the driving amount from a predetermined reference position.

Even in a configuration in which the MR sensor 77 is mounted on the lens frame 81 to be movable and the magnetized plate 76 is fixed, the position of the lens L can be similarly determined.

In such a driving device, the position is directly detected by reading the scale, so that the position of the lens can always be known correctly. For example, even when the magnitude of the sliding contact force between the drive shaft and the lens frame fluctuates due to a processing error and the amount of drive of the lens frame due to one expansion and contraction of the piezoelectric actuator is not constant, no error occurs in the detected lens position. . In other words, highly accurate position detection is possible regardless of the accuracy of the driving mechanism.

[0011]

When two or more driven members are individually driven in the same or opposite directions by the above method, a driving element such as a piezoelectric actuator, a driving shaft, a scale member and a sensor are connected to the driven member. You only have to prepare for each. However, when it is necessary to keep the driven members in a predetermined positional relationship at all times, it is necessary to precisely align each scale member, and extremely high assembling accuracy is required.

For example, in a zoom lens in which two lenses are driven to change the focal length, if an error occurs in the relative position of the lenses, a desired focal length cannot be obtained. Therefore, it is necessary to drive each lens while keeping the relative positions of the lenses strictly. For this reason, it is necessary to perform the alignment of the two scale members with high accuracy, and it takes a long time to adjust the position during assembly.

Further, if a scale member is provided for each driven body, it becomes necessary to secure a space for disposing each scale member, which hinders miniaturization of the apparatus. This disadvantage is
This occurs even when it is not necessary to keep the driven body in a predetermined positional relationship.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a plurality of driven objects are individually driven in the same direction or opposite directions, and the scale is read to detect the position of each driven object. An object of the present invention is to provide a driving device having a simple configuration with high accuracy.

[0015]

In order to achieve the above object, according to the present invention, there is provided a driving device for individually driving a plurality of driven members in the same direction or in opposite directions to individually detect the positions of the driven members. And a scale member whose physical property changes at predetermined intervals along the driving direction of the driven body, and a sensor for detecting the physical property, wherein the scale member and the sensor are arranged in accordance with the driving of the driven body. In a device that changes the relative position and detects the position of the driven body based on the number of changes in the physical properties detected by the sensor, one scale member is fixed to the device main body, and the scale member is opposed to the scale member. A sensor is provided for each driven body.

In this driving device, the surface of the scale member is given predetermined physical properties and is used as a scale.
One scale member is used for detecting the positions of all driven bodies. Therefore, the space required for arranging the scale members is minimized. In addition, since there is no displacement of the scale read by each sensor, it is possible to accurately set all driven members to a desired positional relationship.

The scale member may also serve as a regulating member for regulating the movement of the driven body in a direction perpendicular to the driving direction. In this configuration, there is no need to separately provide a regulating member, and the required space is further reduced.

The scale member may have only one surface having the above-mentioned physical properties. If this surface is flat, all the sensors face the scale member from the same direction. If the scale member is cylindrical and has a curved surface, each sensor can be opposed to the scale member from a different direction, and the degree of freedom in the arrangement of the sensor and the driven body increases.

The scale member may be provided with two flat surfaces having the above-mentioned physical properties in different directions. Each sensor can be opposed to the scale member from any direction, and the restriction on the arrangement position of the sensor and the driven body with respect to the scale member is reduced. For example, if the scale member is formed in a flat plate shape and the both sides have the above-described physical properties, the sensor and the driven body can be arranged on both sides of the scale member.

The physical properties used as the scale on the surface of the scale member may be arbitrarily set, for example, magnetic. In this case, an N pole and an S pole are alternately formed on the surface of the scale member, and a magnetoresistive sensor whose electric resistance changes according to magnetism is used as a sensor. The magnetic poles can be formed at minute intervals, and the sensitivity of the magnetoresistive sensor is high, so that the position of the driven body can be accurately detected.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a driving device according to an embodiment of the present invention. FIG. 1 shows an exploded perspective view of the driving device 1 according to the first embodiment. Drive unit 1
Denotes two movable lenses L1 and L2 included in the zoom lens
Are driven while maintaining a predetermined positional relationship to change the focal length while preventing the movement of the focal position. The lenses L1 and L2 are arranged front and rear with their optical axes aligned. The driving range of the lenses L1 and L2 is about several mm.

The drive unit 1 includes two piezoelectric actuators 11a and 11b, two drive shafts 12a and 12b, one guide shaft 13 also serving as a scale member, and two MR sensors 1
4a, 14b and support walls 16, 17. The rear ends of the piezoelectric actuators 11a and 11b are fixed to an apparatus main body (not shown), and expand and contract in the front-rear direction according to the applied voltage. The drive shafts 12a and 12b have their rear ends fixed to the front end surfaces of the piezoelectric actuators 11a and 11b, respectively, and are displaced in the axial direction as the piezoelectric actuators 11a and 11b expand and contract.

The drive shafts 12a and 12b are formed of a highly rigid material such as carbon resin, are arranged in parallel, and are slidably supported by support walls 16 and 17 in the axial direction. The guide shaft 13 is arranged below and parallel to the centers of the drive shafts 12a and 12b, and is fixed to the support walls 16 and 17.

The support walls 16, 17 are arranged in parallel and fixed to the main body of the apparatus. The support wall 16 includes a drive shaft 12a,
Through holes 16a and 16b which lightly contact the outer peripheral surfaces thereof through the front end of 12b, fixing holes 16c which fix through the front end of the guide shaft 13, and light from the front through the lens L
It has a large-diameter opening 16d for leading to 1. Support wall 17
Are through holes 17a, 17b which lightly slide on the outer peripheral surfaces of the drive shafts 12a, 12b through rear end portions thereof, and the guide shaft 1
3 has a fixing hole 17c for fixing through the rear end, and a large-diameter opening 17d for guiding light transmitted through the lenses L1 and L2 backward. At the lower part of the support wall 17, an MR
A notch 17e is formed for passing the flexible printed circuit boards 20a and 20b to which the sensors 14a and 14b are fixed.

The lenses L1 and L2 are respectively connected to the lens frame 21.
a, 21b, and are held by the lens frames 21a, 21b.
The through hole 23 through which the drive shafts 12a and 12b pass
Protrusions 22a and 22b having a and 23b are provided. Drive shafts 12a, 12b are provided on the side surfaces of the protrusions 22a, 22b.
An opening for exposing b is formed, and leaf springs 24a and 24b for pressing the drive shafts 12a and 12b exposed from the opening with an appropriate force are screwed. Through holes 23a, 23b are pressed by the pressing force of leaf springs 24a, 24b.
Are in sliding contact with the drive shafts 12a and 12b.

At the lower center of the lens frames 21a and 21b,
Protrusions 26a and 26b having a groove through which the guide shaft 13 passes are provided. The upper surfaces of the grooves of the protruding portions 26a and 26b are formed horizontally, and the ends of the flexible printed circuit boards 20a and 20b to which the MR sensors 14a and 14b are fixed have the detection surfaces of the MR sensors 14a and 14b facing downward. It is fixed. The left and right inner surfaces of the grooves of the protrusions 26a and 26b are formed vertically, and are in sliding contact with the outer peripheral surface of the guide shaft 13. The guide shaft 13 regulates the movement of the lens frames 21 a and 21 b in a direction perpendicular to the driving direction, and
a, rotation around 12b is prevented.

The piezoelectric actuators 11a and 11b include:
The voltage as shown in FIG. 10 is applied. The lenses L1 and L2 are driven in one direction by repeatedly increasing and gradually decreasing the applied voltage as shown in FIG. 11A, and gradually increased and suddenly as shown in FIG. It is driven in the opposite direction by repeating the lowering. The voltages applied to the piezoelectric actuators 11a and 11b are individually controlled, and the lenses L1 and L2 are maintained in a predetermined positional relationship.

FIG. 2 shows the appearance of the guide shaft 13. The guide shaft 13 is made of a resin containing a magnetized material, and has a shape in which a part of a cylinder is removed in parallel with the central axis, that is, a cylindrical shape having a flat portion parallel to the central axis. On the surface 13a of the flat portion, a large number of N poles and S poles are alternately magnetized in the axial direction at a predetermined pitch of about 100 μm. The guide shaft 13 is horizontally fixed to the support walls 16 and 17 with the magnetized surface 13a facing upward, and comes into contact with the inner surfaces of the grooves of the protrusions 26a and 26b at both ends of the diameter. Also, MR
The detection surfaces of the sensors 14a and 14b are parallel to the magnetization surface 13a, and face the magnetization surface 13a at a predetermined distance.

A magnetic field is formed around the MR sensors 14a and 14b at regular intervals along the moving direction by the magnetized surface 13a of the guide shaft 13. When the lenses L1 and L2 are driven, the magnetic environment of the MR sensors 14a and 14b fixed to the lens frames 21a and 21b changes periodically, and the output values of the MR sensors 14a and 14b also change periodically. MR
Number of changes in output values of sensors 14a and 14b and magnetized surface 1
The drive amounts of the lenses L1 and L2 are calculated from the magnetization pitches of the N pole and S pole of 3a, and the positions of the lenses L1 and L2 are obtained by integrating the drive amounts from a predetermined reference position.

Actually, not only the maximum and minimum values of the output values of the MR sensors 14a and 14b are counted, but also the MR sensor 1
The position of the MR sensors 14a and 14b with respect to the magnetized surface 13a is obtained more precisely by performing an interpolation process on the output values of the 4a and 14b. Thus, the positions of the lenses L1 and L2 can be detected with high accuracy of 1/10 or less of the magnetization pitch of the magnetization surface 13a.

As described above, the driving device 1 uses the magnetized surface 13a as a scale for detecting the positions of the lenses L1 and L2, and the scale read by the MR sensor 14a and the scale read by the MR sensor 14b are misaligned. Can not occur, and there is no error due to the displacement of the scale in the detected relative position between the lens L1 and the lens L2. Lens L1
And the lens L2 are individually driven. However, by driving while detecting the position, it is possible to drive the lenses L1 and L2 while always maintaining a strictly desired positional relationship. In addition, since there is one scale member and the guide shaft 13 is also used as the scale member, the space utilization efficiency is high, and the drive device 1 can be formed small.

FIG. 3 shows the appearance of the driving device 2 of the second embodiment.
And an exploded perspective view is shown in FIG. This driving device 2 also
Like the driving device 1, the two driving lenses L1 and L2 included in the zoom lens are driven, and two piezoelectric actuators 31a and 31b, two driving shafts 32a,
32b, two MR sensors 34a and 34b, and a frame 35.

The frame 35 has a guide wall 38 located at the center in the left and right direction and extending in the front-rear direction, and a support wall 3 perpendicular to the guide wall 38.
6 and 37, and a base 39 is fixed to the rear part.
The support walls 36, 37 have through holes 36a, 36 for slidably supporting them through the drive shafts 32a, 32b.
b and 37b are formed. 3 and 4, the through hole of the support wall 37 that supports the drive shaft 32a is not shown. The piezoelectric actuators 31a and 31b have their rear end surfaces fixed to the base 39, and the drive shafts 32a and 32b are arranged on both sides thereof in parallel with the guide wall 38.

The lenses L1 and L2 are respectively connected to a lens frame 41.
a, 41b, and are held by the lens frames 41a, 41b.
The through hole 43 through which the drive shafts 32a and 32b pass
Protrusions 42a and 42b having a and 43b are provided. Drive shafts 32a, 32 are provided on the side surfaces of the protrusions 42a, 42b.
An opening for exposing b is formed, and leaf springs 44a and 44b for pressing the drive shafts 32a and 32b exposed from the opening with an appropriate force are screwed. The through-holes 43a, 43b are pressed by the pressing force of the leaf springs 44a, 44b.
The inner surface of the slidably contacts the drive shafts 32a and 32b. Lens frame 4
In the protrusions 42a, 42b of 1a, 41b, through holes 45a, 45b having a rectangular cross section are formed so as to face the guide wall 38.

The MR sensors 34a and 34b are fixed to the ends of the flexible printed circuit boards 40a and 40b, and inserted into the through holes 45a and 45b. MR sensor 34a,
34b has four side surfaces in contact with the inner surfaces of the through holes 45a and 45b, and is movable in the vertical direction with respect to the guide wall 38, and is restricted from moving and rotating in the vertical direction with respect to the moving direction. Held in state.

On the left and right sides of the frame 35, leaf springs 47a, 47
b is screwed. The leaf springs 47a and 47b are formed between the projections 42a and 42b of the lens frames 41a and 41b and the substrate 40.
a, 40b for pressing the MR sensors 34a, 34b fixed to the guide wall 38.

FIG. 5 shows the lens frame 41a viewed from the front and its peripheral portion. The protrusions 42a and 42b pressed by the leaf springs 47a and 47b contact the surface of the guide wall 38, and thereby the lens frame 4 around the drive shafts 32a and 32b.
The rotation of 1a, 41b is prevented. MR sensor 34a,
A spacer 34c having a uniform thickness is stuck on the surface of 34b, and M is pressed by leaf springs 47a and 47b.
The R sensors 34a and 34b are maintained at a fixed distance from the surface of the guide wall 38 by the spacer 34c contacting the guide wall 38.

FIG. 6 shows the guide wall 38 viewed from the side.
The guide wall 38 is made of a resin containing a magnetized material, and a large number of N poles and S poles are provided at a predetermined pitch of about 100 μm on the left and right side surfaces of the drive shaft 32a at a predetermined pitch of about 100 μm. 32b are alternately magnetized in the axial direction. The left and right magnetized surfaces 38a are formed such that the mutual positions of the magnetic poles are aligned.

A magnetic field is formed around the MR sensors 34a and 34b at regular intervals along the moving direction by the magnetized surface 38a of the guide wall 38. When the lenses L1 and L2 are driven, the magnetic environment of the MR sensors 34a and 34b attached to the lens frames 41a and 41b changes periodically,
The positions of the lenses L1 and L2 are obtained from the outputs of the sensors 34a and 34b.

In the driving device 2 of the present embodiment, the lens L1,
Separate magnetized surfaces are used as graduations for detecting the position of L2, but since these graduations are provided on the same member, there is no displacement between the graduations due to mounting errors. Therefore, the relative positions of the lenses L1 and L2 can always be detected correctly, and the lenses L1 and L2 can be driven while maintaining the desired positional relationship strictly. In addition, there is one scale member, and the guide wall 3
Since the scale member 8 is also used as the scale member, the space utilization efficiency is high and the driving device 2 can be formed small.

In each of the above embodiments, the magnetic poles are regularly formed on the surface of the guide shaft 13 or the guide wall 38 and are used as scales. However, the physical properties used as scales are not limited to magnetism. Instead, any material may be used as long as it can be provided regularly. For example, light reflectivity and conductivity can be used.

FIG. 7 shows a configuration of a scale member and a sensor of a driving device according to a third embodiment using light reflectivity as a scale.
Is shown schematically in FIG. The scale member 51 is fixed to the apparatus main body, and has a flat surface 51a provided with a black and white pattern at a predetermined pitch. The white portion W of the pattern has a high light reflectance, and the black portion B has a low reflectance. The sensors 52 a and 52 b are attached to driven members (not shown) that are individually driven, and are arranged to face the surface 51 a of the scale member 51. The sensors 52 a and 52 b move in parallel with the scale member 51 by driving the driven body.

The sensors 52a and 52b are connected to the scale member 51.
Light-emitting elements 53a, 53 that emit light toward the surface 51a of the
b and light receiving elements 54a and 54b that receive light reflected by the surface 51a. As the light emitting elements 53a and 53b, for example, a light emitting diode and a laser diode,
As the light receiving elements 54a and 54b, for example, photodiodes and phototransistors are used. The light emitting elements 53a and 53b are set so as to emit a light beam having a diameter smaller than the width of one section of the black and white pattern on the surface 51a of the scale member 51.

The amount of light incident on the light receiving elements 54a and 54b is periodically determined depending on whether the light from the light emitting elements 53a and 53b hits the white portion W or the black portion B of the pattern due to the movement of the driven body. Changes to Thereby, the movement amount of the driven body is detected, and the position of the driven body is obtained by integrating the movement amount from a predetermined reference position.

FIG. 8 schematically shows a configuration of a scale member and a sensor of a driving device according to a fourth embodiment using conductivity as a scale. The scale member 61 has a columnar shape and is fixed to the apparatus main body. The scale member 61 is made of an insulating material, and a conductive material C such as aluminum is vapor-deposited on the outer peripheral surface 61a of the scale member 61 so as to be provided with a predetermined pitch over the entire circumference. The sensors 62a and 62b are attached to driven members (not shown) that are individually driven, and face the scale member 61 in different directions. The sensors 62 a and 62 b move parallel to the scale member 61 by driving the driven body.

The sensor 62a has two electric terminals 63a, 6
4a. The terminals 63a and 64a are connected to the scale member 6.
The scale member 61 is disposed in a plane perpendicular to one axis.
Is in contact with the outer peripheral surface 61a. The width of the terminals 63a and 64a is set smaller than the width of the insulating portion I or the conductive portion C where the outer peripheral surface 61a is exposed. The sensor 62b is configured in exactly the same way, and its two electric terminals 63b, 64
b is in contact with the outer peripheral surface 61a of the scale member 61.

The terminals 63a and 64a and the terminals 63b and 64b
Are periodically changed depending on whether the driven bodies move in contact with the conductive section C or the insulating section I due to the movement of the driven bodies. Thereby, the movement amount of the driven body is detected, and the position of the driven body is obtained by integrating the movement amount from a predetermined reference position.

When the sensor is made to face a single scale member from different directions as in the present embodiment, the degree of freedom of the arrangement of the sensor and the driven body is increased, and the apparatus can be driven even when many driven bodies are driven. The design is easy.

The physical properties to be used as the scale may be selected in consideration of the type of the driven body and the difficulty of the use and configuration of the driving device including the required detection accuracy and the like. In particular, a configuration in which a magnetic field is detected by an MR sensor using magnetism has high detection accuracy, and is therefore suitable for precision equipment such as a photographing lens of a camera.

[0050]

According to the driving device of the present invention, the space occupied by the scale member can be minimized, so that the device can be downsized and other members can be easily arranged. In addition, since there is no displacement of the scale read by each sensor, it is possible to accurately set all driven members to a desired positional relationship. In addition, the number of components is small, and precise positioning between the scale members is not required, so that the cost can be reduced.

In a configuration in which a scale member is also used as a regulating member for regulating the movement of the driven body in the direction perpendicular to the driving direction, the space utilization efficiency is further improved and the number of parts is further reduced.

In the configuration in which the sensor is opposed to the scale member from the same direction, the entire apparatus including the driven body can be reduced in size. There are few restrictions on the arrangement of the driving body, and the apparatus can be designed freely according to the application.

If the magnetism on the surface of the scale member is detected by a magnetoresistive sensor, the detection accuracy is extremely high, and the driven body can be strictly set at a desired position. Therefore, it is suitable when the relative position of the driven body needs to be set particularly strictly.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a driving device according to a first embodiment.

FIG. 2 is a perspective view of a guide shaft of the driving device according to the first embodiment.

FIG. 3 is a perspective view of a driving device according to a second embodiment.

FIG. 4 is an exploded perspective view of a driving device according to a second embodiment.

FIG. 5 is a front view of a lens frame of a driving device according to a second embodiment and peripheral portions thereof.

FIG. 6 is a side view of a guide wall of a driving device according to a second embodiment and peripheral portions thereof.

FIG. 7 is a perspective view of a scale member and a sensor of a driving device according to a third embodiment.

FIG. 8 is a perspective view of a scale member and a sensor of a driving device according to a fourth embodiment.

FIG. 9 is an exploded perspective view of a conventional driving device.

FIG. 10 is a diagram showing an example of a voltage applied to a piezoelectric actuator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive device 11a, 11b Piezoelectric actuator 12a, 12b Drive shaft 13 Guide shaft (scale member) 14a, 14b MR sensor 16, 17 Support wall 20a, 20b Flexible printed circuit board 21a, 21b Lens frame 22a, 22b Projection 24a, 24b Plate Spring 26a, 26b Projection 2 Drive 31a, 31b Piezoelectric actuator 32a, 32b Drive shaft 34a, 34b MR sensor 35 Frame 36, 37 Support wall 38 Guide wall (scale member) 40a, 40b Flexible printed circuit board 41a, 41b Lens frame 42a, 42b Projection 44a, 44b Leaf spring 45a, 45b Through hole 47a, 47b Leaf spring 51 Scale member 52a, 52b Sensor 53a, 53b Light emitting element 54a, 54b Light receiving element 61 Scale member 62a, 62b Sa 63a, 63b terminal 64a, 64b terminal L1, L2 lens (driven member)

Claims (5)

[Claims] 1. A driving device for individually driving a plurality of driven members in the same direction or in opposite directions to individually detect the positions of the driven members, wherein the physical properties of the surface are along the driving direction of the driven members. A scale member that changes every predetermined distance, and a sensor that detects the physical property, changes the relative position of the scale member and the sensor according to the driving of the driven body, and changes the physical property detected by the sensor. In the apparatus for detecting the position of a driven body based on the number of times, one scale member is fixed to the apparatus main body, and a sensor is provided on each of the driven bodies so as to face the scale member. Characteristic drive device. 2. The driving device according to claim 1, wherein the scale member also functions as a regulating member that regulates the movement of the driven body in a direction perpendicular to the driving direction. 3. The scale member has a surface having the above-mentioned physical properties.
The drive device according to claim 1, wherein the drive device includes only one drive. 4. The scale member has two flat surfaces having the physical properties in different directions.
3. The driving device according to claim 1. 5. The physical property is magnetic, and N and S poles are alternately formed on the surface of the scale member, and the sensor is a magnetoresistive sensor whose electric resistance changes according to the magnetism. The driving device according to claim 1, wherein: