JP2003177442A - Lens driver and method of adjusting lens driver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens driver which can perform exact and stable lens driving without depending upon the differences in postures and individuals and a method of adjusting the lens driver. <P>SOLUTION: The driving Duty to a voltage driver is increased by slightly each (S40) and the driving Duty values when a shake correcting lens moves are written into an EEPROM (S50, S60). The above writing is performed with an X-axis and Y-axis, respectively, to obtain adjustment values. The dead zone of the voltage driver is offset and corrected by using the adjustment values in driving. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens driving device and an adjusting method of the lens driving device in an optical device such as a silver halide camera, a digital still camera, an interchangeable lens, a video camera and binoculars.

[0002]

2. Description of the Related Art Conventionally, it has been used in a shake correction device for detecting a camera shake and moving a part or all of a photographing optical system in a direction for canceling the camera shake to correct an image shake on an image pickup surface. A lens driving device is known. FIG. 7 is a diagram showing an outline of a camera shake correction device. The blur generated in the camera has a total of 6 degrees of freedom including a rotational movement of 3 degrees of freedom including pitching, yawing and rolling movements and a translational movement of 3 degrees of freedom including movements in the X-axis, Y-axis and Z-axis directions. The shake correction device normally corrects a shake caused by a two-degree-of-freedom motion including pitching and yawing motions.

The camera shake is caused by angular velocity sensors 30x, 3
Monitored by 0y. Angular velocity sensor 30x, 30y
Usually uses a piezoelectric vibration type angular velocity sensor that detects a Coriolis force generated by rotation. The angular velocity sensor 30x is
The yaw shake is detected, and the angular velocity sensor 30y
Detects pitching shake. When performing image stabilization,
The outputs of the angular velocity sensors 30x and 30y are transferred to the lens CPU.
6, the target drive position of the shake correction lens 101 is calculated. An instruction signal is sent to the voltage drivers 61x and 61y to drive the shake correction lens 101 to the target drive position,
The voltage drivers 61x and 61y follow the instruction signal,
VCM (voice coil motor) 120x, which is a drive unit,
120y is driven.

The position of the blur correction lens 101 is monitored by the lens position detectors 110x and 110y, and the lens CP
Give feedback to U6. The lens CPU 6 controls the blur correction lens 101 from the target drive position and the position of the blur correction lens 101.

[0005]

However, the voltage drivers 61x and 61y used in the conventional lens driving device.
Generally have a dead zone. FIG. 8 is a conceptual diagram illustrating a dead zone included in the voltage driver. The horizontal axis of FIG. 8 is an instruction signal input to the voltage driver, and is indicated by%. For example, in the case of an 8-bit voltage driver, the input signal Duty is 100% = 256. The vertical axis of FIG. 8 represents the output from the voltage driver. In the example shown in FIG. 8, the output signal is not output when the input signal is in the range of −5% to 5%. This range is called a dead zone. In this dead zone, even if the coil is connected to the voltage driver, no current flows through the coil.
In this example, the input signal exceeds 5% or -5%
When the output signal is below the input signal,
It becomes linear and is output.

There is a problem that such a dead band of the voltage driver adversely affects the control result of the shake correction lens 101. Specifically, there are cases where fine control cannot be performed due to the influence of the dead zone. The adverse effect of the dead zone may or may not occur due to the attitude difference of the camera. When the camera is supported in the horizontal direction (horizontal position), with respect to shake correction in the y-axis direction, a bias-like force that constantly lifts the shake correction lens 101 against gravity is necessary. For example, when 5 V is applied to the VCM 120y and a VCM that generates a force four times the weight of the movable part is used, the bias voltage to counter gravity is 1.25 V, and when 5 V is applied to the voltage driver 61y, The drive duty is 25%. That is, when the shake correction operation is performed, the drive is performed centering on the duty of 25%, and a linear region outside the dead zone of the voltage driver is used. Therefore, in this case, the adverse effect of the dead zone does not occur.

However, when the shake correction is performed in the x-axis direction, a biasing force that opposes gravity is not necessary, and when the shake correction is performed, it is necessary to drive the drive duty 0% as the center. Therefore, there is a problem that fine control cannot be performed due to the influence of the dead zone of the voltage driver 61x, and the lens control result particularly in the horizontal direction is deteriorated. When the camera is held in the vertical direction (longitudinal position), such a position difference adversely affects the dead zone in the y-axis direction. Further, the range of the dead zones of the voltage drivers 61x and 61y has individual differences and is different for each voltage driver. Therefore, there is a problem that there are individual differences for each camera in addition to the attitude difference.

An object of the present invention is to provide a lens driving device and a method for adjusting the lens driving device, which are capable of performing accurate and stable lens driving irrespective of posture differences and individual differences.

[0009]

The present invention solves the above-mentioned problems by the following means for solving the problems. It should be noted that, for ease of understanding, reference numerals corresponding to the embodiments of the present invention will be given and described, but the present invention is not limited thereto. That is, in the invention of claim 1, the movable lens part (10
1) and a driving unit (120) for driving the lens unit,
Even if the control unit (8) for controlling the drive unit, the driver unit (61) for outputting a drive current to be supplied to the drive unit according to the instruction signal obtained by the control unit, and the instruction signal are input. A storage unit (62) that stores dead zone amount information regarding a range of the instruction signal that is a dead zone in which the driver unit does not output the drive current, and the dead zone amount information stored in the storage unit is the driver. It is a lens driving device characterized in that it is a value that can be adjusted according to individual differences of parts.

According to a second aspect of the present invention, in the lens driving device according to the first aspect, the control section (8) gives an instruction signal in consideration of the dead zone amount information stored in the storage section (64). The lens driving device is characterized in that the influence of the dead zone of the driver section is reduced or eliminated by transmitting it to the driver section (61).

The invention of claim 3 is the invention of claim 1 or claim 2.
In the lens driving device according to the item (1), the lens unit (10
1) is a blur correction lens that is movable in the X-axis direction and the Y-axis direction that are substantially orthogonal to each other, and that moves in the X-axis direction and / or the Y-axis direction to correct the blurring of an image, The drive unit (120) and the driver unit (6)
1) is an X-axis direction drive unit (120x) and a Y-axis direction drive unit (1) respectively corresponding to the X-axis direction and the Y-axis direction.
20y), an X-axis direction driver section (61x), and a Y-axis direction driver section (61y), and the dead zone amount information corresponds to the X-axis direction driver section and the Y-axis direction driver section, respectively. A lens driving device having quantity information and Y-axis direction dead zone quantity information.

The invention of claim 4 is from claim 1 to claim 3.
In the lens driving device according to any one of items 1 to 5,
A lens driving device comprising: an adjustment operation control unit (6) for controlling an operation required for performing an adjustment operation of storing the dead zone amount information as an adjustment value in the storage unit.

The invention of claim 5 is from claim 1 to claim 4.
An adjustment method for storing the dead zone amount information in the storage unit as an adjustment value in the lens driving device according to any one of items 1 to 4, wherein the instruction signal is increased little by little, and the lens unit (101) Is stored in the storage section (62) as the adjustment value, which is a value corresponding to the instruction signal when the movement of the lens is started.

According to a sixth aspect of the invention, there is provided the method of adjusting a lens driving device according to the fifth aspect, wherein the driver (61) is used.
x, 61y) is provided, the adjustment is performed for each driver.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in more detail below with reference to the drawings. Figure 1
FIG. 3 is a diagram showing an embodiment of a blur correction lens and a camera including a lens driving device according to the present invention. FIG. 2 is an enlarged view of the blur correction unit 100. In addition, the same reference numerals are given to the portions having the same functions as those of the conventional example described above, and the duplicated description will be appropriately omitted. FIG. 1 and FIG. 2 show only the parts necessary for detecting the pitching occurring in the camera system and moving the shake correction lens 101 in the y-axis direction to correct the shake. The subscript y used in the description is omitted. x
Regarding the axial direction, since it has the same configuration as the y-axis direction,
Detailed description here is omitted.

(Interchangeable Lens) As shown in FIGS. 1 and 2, the interchangeable lens 1 includes a fixed barrel 1a, a movable barrel 1b, a lens CPU 6, a target position conversion unit 7, a control unit 8 and a photographing optical system. A first lens group 10, a second lens group 11, a shake correction lens (third lens group) 101 and a fourth lens group 13, which form a system, a lens frame 102, and a steel ball 103.
, Biasing spring 104, angular velocity sensor 30, and VCM1
20, a position detection device 110, a lock mechanism 130,
Filter 60, voltage drivers 61 and 65, and EEP
The ROM 62, the focal length detection unit 63, and the subject distance detection unit 64 are provided.

The fixed barrel 1a is a member for movably supporting the movable barrel 1b. The fixed barrel 1a includes the fourth lens group 13
Is stored. The fixed barrel 1a is detachably attached to the camera body 2. The movable barrel 1b includes a first lens group 10, a second lens group 11, and a shake correction lens 101.
It is a member that moves in the optical axis I direction together with. Moving cylinder 1
Reference numeral b contains the first lens group 10, the second lens group 11, and the blur correction lens 101.

The first lens group 10 moves in the direction of the optical axis I to perform focus adjustment for forming an image of a subject on the film surface 20. A first lens group 10, a second lens group 11,
All or part of the blur correction lens 101 and the fourth lens group 13 moves in the optical axis I direction to continuously change the focal length. The blur correction lens 101 is driven in a direction orthogonal to the optical axis I (direction of arrow in the figure) to correct blur.

The blur correction lens 101 is a lens unit which is driven in a plane (XY plane) orthogonal to the optical axis I to correct blur. The shake correction lens 101 is fitted into the inner peripheral portion of the lens frame 102 and is caulked and held. The lens frame 102 is a holding member that holds the image stabilization lens 101, and is provided with a coil 121.

The steel ball 103 and the biasing spring 104 have an optical axis I.
A support member that movably supports the lens frame 102 in a plane perpendicular to the lens frame 102. The support member is disposed so as to be in contact with the recess 102b provided in the lens frame 102, and is interposed between the lens frame 102 and the right substrate 105. However, the lens frame 102 can operate smoothly. Biasing spring 1
04 presses the lens frame 102 against the steel ball 103,
By supporting the lens frame 102 by the steel ball 103, the lens frame 102 is movable only within the plane and is biased so as not to move in the optical axis I direction.

The angular velocity sensor 30 is a sensor for detecting shake generated in the camera. The angular velocity sensor 30 is, for example, a piezoelectric vibration type angular velocity sensor that detects a Coriolis force generated by rotation. The angular velocity sensor 30 outputs an angular velocity signal according to the detected angular velocity to the filter 60.

The VCM 120 is a drive unit (actuator) that generates a driving force for driving the shake correction lens 101 in a plane perpendicular to the optical axis I (in the XY plane). The VCM 120 includes a coil 121 attached to the lens frame 102, a magnet 122, and a magnet 12.
2, a magnet 123 that forms a magnetic field between the magnet 124 and a yoke 124 that fixes the magnet 12,
3 and a yoke 125 for fixing the same. York 12
5 is fixed to the right substrate 105, and the yoke 124 is fixed to the left substrate 106.
The gap between V and V is properly maintained.
The CM 120 is a magnet 1 divided into two poles and magnetized.
A magnetic circuit is formed between 22 and 123. VCM12
0 means that when a current flows through the coil 121 in the magnetic field lines,
An electromagnetic force is generated by Fleming's left-hand rule in the direction perpendicular to the direction of current flow and the direction of magnetic force lines. VCM12
0 is due to the drive current output by the voltage driver 61,
When the coil 121 is energized, a driving force in the y-axis direction is generated to drive the shake correction lens 101.

The position detecting device 110 is a device for detecting the position of the blur correction lens 101 in a plane perpendicular to the optical axis I. The position detection device 110 includes an infrared light emitting diode (hereinafter referred to as IRED) 111, a one-dimensional position detection element (hereinafter referred to as PSD) 112, and an IRED.
111 and a PSD 112, and a slit plate 102a that is attached to the outer peripheral portion of the lens frame 102 and that limits the light flux from the IRED 111.
The position detection device 110 is an IR fixed to the left substrate 106.
The infrared light projected from the ED 111 and incident on the PSD 112 fixed to the right substrate 105 through the slit plate 102a is detected. The position detection device 110 includes the slit plate 10
By moving 2a, the position of the center of gravity of the light moving on the PSD 112 is monitored and detected, and the blur correction lens 10
The actual drive position of 1 is detected. Position detection device 110
Feeds back current position information (position detection signal) regarding the current position of the shake correction lens 101 to the control unit 8.

The lock mechanism 130 is used for the blur correction lens 10
It is a mechanism for locking 1. The image stabilization lens 101 is
When the shake correction operation is not performed, the lens center position needs to be locked in the vicinity of the optical axis I.
This lock is performed by 0. Lock mechanism 130
Is a latch solenoid 131, a seesaw lever 132,
A lock pin 133 is provided. Latch solenoid 13
Reference numeral 1 denotes an actuator whose tip portion moves in the left-right direction in the figure when energized, and maintains the state even when the energization is released. For unlocking, for example, the tip end of the latch solenoid is driven to the right in the figure, the seesaw lever 132 rotates counterclockwise about the fulcrum, and the lock pin 22 is driven to the left. The lock pin 22 is supported by being fitted to the left substrate 106, and can be smoothly operated only in the optical axis direction.

The lens CPU 6 is a central processing unit for performing various controls on the interchangeable lens 1 side. The lens CPU 6 calculates the focal length based on the pulse signal output from the focal length detection unit 63, and calculates the subject distance based on the pulse signal output from the subject distance detection unit 64. Lens CP
U6 includes a target position conversion unit 7 and a control unit 8. The lens CPU 6 uses the lens contact point 90 provided between the interchangeable lens 1 and the camera body 2 to connect the body side C
Communication with the PU 9 is possible. Also, the lens CPU
6 is a lock solenoid 1 via a voltage driver 65.
It is possible to control the energization to 31 and issue a drive instruction for locking and unlocking the shake correction lens 101. Further, the lens CPU 6 monitors the state of the blur correction switch 3 provided on the interchangeable lens 1. Anti-shake switch 3
Is ON, shake correction control is performed, and if the shake correction switch 3 is OFF, the shake correction start command from the camera body 2 is ignored and shake correction is not performed.

The target position conversion section 7 converts the output signal of the filter 60 into target position information for driving the shake correction lens 101 to the target position. The target position conversion unit 7 sets the output signal (analog signal) of the filter 60 to A
The target drive position of the shake correction lens 101 is calculated by the target position conversion unit on the basis of the focal length information, the subject distance information, and the information peculiar to the lens written in the EEPROM 62, which is quantized and captured by the / D conversion. The target position conversion unit 7 outputs information on the calculated target drive position to the control unit 8. The target position conversion unit 7 includes a control unit 8 and a filter 6
0, the EEPROM 62, the focal length detection unit 63, and the subject distance detection unit 64 are connected.

The control section 8 is a section that controls the VCM 120 and performs follow-up control so that the shake correction lens 101 is driven according to the information of the target drive position. The control unit 8 is shown in FIG.
The control of the VCM 120 is changed so as to cancel the fluctuation of the frictional force generated between the guide surface 14a and the steel ball 15a shown in FIG. The control unit 8 converts the position detection signal (analog signal) output by the position detection device 110 into a digital signal and takes it in. The controller 8 calculates a drive signal based on the target position information and outputs the digital drive signal to the voltage driver 61. A PSD 112, a voltage driver 61, and an EEPROM 62 are connected to the control unit 8.

The filter 60 is a low pass filter for removing a predetermined frequency component from the output signal of the angular velocity sensor 30. The filter 60 cuts noise components and DC components included in the high frequency band. The filter 60 is
The angular velocity signal after removing the predetermined frequency component is output to the target position conversion unit 7.

The voltage driver 61 is a driver unit that supplies electric power to the VCM 120 according to the input drive signal (drive voltage). The voltage driver 61 includes a coil 121.
Connected to the drive signal, performs switching for the drive signal, applies a voltage to the coil 121 of the VCM 120, and
The M120 is driven. The voltage driver 61 has a dead zone as described in the related art. The voltage driver 65 is a driver that supplies electric power for driving the latch solenoid 131.

The EEPROM 62 stores lens data which is various unique information about the interchangeable lens 1, a coefficient for converting a pulse signal output from the object distance detecting section 64 into a physical quantity, and dead zone quantity information described later. It is a non-volatile storage unit for storing.

The focal length detector 63 is a zoom encoder or the like for detecting the focal length. Focal length detector 63
Is a target position conversion unit 7 that outputs a pulse signal according to the focal length value.
Output to.

The subject distance detector 64 is an encoder or the like for detecting the distance to the subject. The subject distance detection unit 64 detects the position of the photographing optical system and outputs a pulse signal corresponding to the position to the target position conversion unit 7.

(Camera Main Body) The camera main body 2 includes a CPU 9 on the body side, a finder screen 20, a finder optical system 21, an eyepiece lens 22, and a finder optical system 2.
1 and the eyepiece lens 22 are provided with a quick return mirror 23 that distributes the light flux that has passed through the photographing optical system, a lens contact 90, and a release switch 91.

The body side CPU 9 is a central processing unit for performing various controls of the entire camera system. CPU on the body side
9 sends a shake correction start command to the lens CPU 6 based on the ON operation of the release switch 91, sends a shake correction stop command to the lens CPU 6 based on the OFF operation of the release switch 91, and various other types. Perform processing.

The release switch 91 is a switch that detects a half-press operation of a release button (not shown) to start a series of shooting preparation operations, detects a full-press operation of the release button, and starts the shooting operation.

Next, the blur correction lens 101 performed by the control unit 8
The control operation (hereinafter referred to as blur correction control) will be described. FIG. 3 is a block diagram of a portion related to blur correction control of the control unit 8. The shake correction control is performed by the PID control unit 8a.
Is performed in combination with the feedforward control performed by the feedforward calculation unit 8b and the offset correction performed by the offset subtraction unit 8c. The target position information converted into the target position of the shake correction lens 101, which is the output of the target position conversion unit 7, is input to the control unit 8 as information necessary for performing the shake correction control. The position information of the blur correction lens 101 obtained by the position detection unit 110 of the blur correction lens 101 is also input to the control unit 8.

(PID control) First, the PID control section 8a
Will be explained. PID control is performed using the deviation between the target position information of the blur correction lens 101 and the lens position information. The lens position information is subtracted from the target position information, and the numerical value is multiplied by the proportional constant Kp (proportional term). Further, the result of subtracting the lens position information from the target position information and the subtracted information one sampling before are added, and the numerical value is multiplied by the integration constant Ki (integral term). Further, the subtracted information one sampling before is subtracted from the result of subtracting the lens position information from the target position information, and the value is multiplied by the differential constant Kd (differential term). Here, Z represents Z conversion, and 1 / Z represents information one sampling before. The result of multiplying the proportional constant Kp by the integral constant Ki by the differential constant Kd,
All are added and output as the output of the PID control unit.

(Feedforward control) While performing PID control, the feedforward value is calculated. As described in the above unit structure, the steel ball 103 is used to smooth the operation on the support portion of the shake correction lens 101, but a frictional force is generated. Anti-shake lens 10
When the driving direction of 1 is reversed, the shake correction lens 101 stops due to the friction of the supporting portion. At this time, if the shake correction lens 101 is not driven with a force greater than the static friction force,
The blur correction lens 101 cannot move.

The feed-forward calculation unit 8b is provided to apply a force to push the shake correction lens 101, which has stopped once, to prevent discontinuous movement due to friction. As described above, this frictional force greatly changes depending on the posture of the shake correction unit due to the influence of the biasing spring 104 in the optical axis direction. It is necessary to change the feedforward output according to the change in the frictional force. That is, when the direction of gravity applied to the unit is applied in the direction in which the shake correction lens 101 is pressed against the sliding portion, the frictional force also increases, so that the feedforward output also needs to be increased. On the contrary, when the direction of gravity applied to the unit is applied in the direction of pulling the shake correction lens 101 away from the sliding portion, the frictional force becomes small, and therefore the feedforward output needs to be lowered.

The operation of the feedforward calculation unit 8b will be specifically described below. Feedforward calculation unit 8b
Then, the target position information three samples before is subtracted from the current target position information. Thereby, the differential value of the target position information is simply acquired. The result of the subtraction is input to the limiter. When the input of the limiter block is u and the output is y, if the input u is larger than a positive predetermined value Fmax, the output y is limited to Fmax, and if the input u is smaller than a negative predetermined value -Fmax, the output y is -Fmax. Limited to and output. This limiter output is the basis of feedforward.

Next, a method of changing the gain of this feedforward will be described. The feedforward calculation unit 8b is
The feed-forward amount is adjusted by using the fact that the control error eventually increases as the attitude of the lens changes. FIG. 4 is a diagram showing how the control error changes in accordance with the magnitude relationship between the frictional force and the feedforward amount. In FIG. 4, the left side of the figure shows a case where the feedforward amount is smaller than the frictional force. The right side of the figure shows the case where the feedforward amount is larger than the frictional force.

When the feedforward amount is smaller than the frictional force, the drive waveform of the shake correction lens 101 behaves as if it stopped at the apex of the target drive waveform. This is because when the speed of the shake correction lens 101 has stopped at 0 and has stopped, the shake correction lens 1 must be subjected to a force greater than the static friction force.
This is because 01 does not start to move and the feedforward amount is smaller than this static friction. When the target drive waveform is subtracted from the drive waveform of the shake correction lens 101, it can be seen that the control error is large at the stopped position.

Next, when the feedforward amount is larger than the frictional force, the drive waveform of the shake correction lens 101 behaves as if it is strongly pressed near the apex of the target drive waveform. This is because the feedforward force begins to work in the opposite direction when the speed of the shake correction lens 101 becomes 0, and at this time, since the feedforward amount is larger than the static frictional force, the direction opposing the frictional force. It is caused by pushing more than frictional force.

By subtracting the lens position waveform from the target drive waveform, the control error waveform due to the frictional force can be found. Further, when this control error waveform is multiplied by the velocity direction of the target drive waveform, the magnitude relationship between the frictional force and the feedforward force can be clearly understood. Figure 4
When the frictional force> feedforward amount on the left side, a control error occurs in the positive direction, whereas when the frictional force <feedforward amount on the right side in FIG. 4, the control error is output in the negative direction. . In this way, the magnitude relationship between the frictional force and the feedforward amount can be determined from the control error, and the feedforward amount can be adjusted.

Returning to FIG. 3, the automatic adjustment of the feedforward amount will be described. The velocity direction of the target position information is calculated, and the result of subtraction is multiplied. This makes it possible to determine whether the feedforward amount is larger or smaller than the frictional force as described above. The output obtained by subtracting the target position information three samples before from the current target position information becomes the velocity component of the target position information. When the input u is F_l <u <F_h, the velocity direction output is y = 1, and the input u is -F_h <.
When u <-F_l, the velocity direction output y = -1 is set, and otherwise y = 0 is set.

This speed direction output is multiplied by the result obtained by subtracting the position information of the shake correction lens 101 from the target position information to determine the magnitude relationship between the frictional force and the feedforward amount.
The output after the multiplication is input to the next determination routine. In this judgment routine, it is judged whether the output after the subtraction is within a predetermined range.

When the input u of the judgment routine is FAmin <u <FAmax, the output y of the judgment routine is a positive constant B.
That is, when the input u is in the above range, it is determined that the feedforward amount is small with respect to the frictional force,
The increment B that increases the feedforward amount will be output.

When the input u of the judgment routine is -FAmax <u <-FAmin, the output y of the judgment routine is a negative constant -B. That is, if the input u is in the above range,
It is determined that the feedforward amount is large with respect to the frictional force, and decrement -B that reduces the feedforward amount is output. FIG. 4 shows the range of this judgment routine.

The outputs of the judgment routine are added by discrete numerical integration with limits. Limits are set so that the result of addition does not become too large or too small. Limit input u is u> L
If max, limit the output y to y = Lmax.
When u <Lmin, the output y is y = Lmin
Restricted to. FFini, which is the initial value of the feedforward amount, is added to this limit output value and output as a numerical value that determines the feedforward amount.

Initial value FFi of this feedforward amount
It is preferable that ni be determined with respect to the frictional force under the normal temperature use environment when the shake correction lens 101 is in the horizontal state.
At the time of shipment from the factory, set the shake correction lens 101 in the horizontal state,
It is necessary to find the feedforward value that minimizes the control error and write the value in the EEPROM or the like using that value as the initial value. In this way, the feedforward variable U2 obtained automatically is multiplied by the above U1 and added to the calculation result of the PID control.

(Offset Correction) Next, an offset subtraction method for correcting the dead zone of the voltage driver 61 from this control output will be described. First, feedforward output and P
The direction component of the added value output of the ID control output is extracted. If the added value output is +, the drive direction output is +1 and
If the added value output is −, the drive direction output is set to −1.
Next, an absolute value calculation of the added value output is performed, and O corresponding to the dead zone amount of the voltage driver 61 obtained by the inspection described later is performed.
FFset_duty_Y is subtracted and output as a drive duty to the voltage driver. OFFset_duty_
Y is an adjustment value for the driver for driving in the Y-axis direction, and an adjustment value OFFs is separately set for the driver for the X-direction.
et_duty_X is provided. When the control calculation of the X-axis drive amount is performed, this value is used as an instruction value to the voltage driver.

Next, a calculation method (adjustment method) of OFFset_duty_Y, which is an adjustment value used for offset correction.
Will be described. FIG. 5 is a diagram showing an adjusting device for adjusting the amount of the dead zone of the voltage driver 61 and the lens barrel being adjusted. The inspection table 71 is provided with a joint part equivalent to a mount provided in the camera body, and the interchangeable lens 1 is mounted on the joint part in an upward direction. A semiconductor laser light source 75 is provided above the interchangeable lens 1. From this semiconductor laser light source 75, a laser beam of a sufficiently collimated parallel light flux is emitted and is incident from the first lens group side. The laser light transmitted through each lens group enters the two-dimensional PSD 72. The two-dimensional PSD 72 is an element that can two-dimensionally detect the barycentric position of light. When the blur correction lens 101 is moved, the light on the two-dimensional PSD 72 also moves, and the position of the blur correction lens 101 can be monitored by the two-dimensional PSD 72.

The reflected light from the two-dimensional PSD 72 has a bad influence on the position detection accuracy due to the influence of the secondary reflection on the lens surface and a bad influence on the returning light to the semiconductor laser light source 75. In order to prevent this adverse effect, the two-dimensional PSD 72 has an antireflection coating applied to the PSD surface to prevent its reflected light, and is further mounted at a slight inclination with respect to the laser light. Two
The output from the dimension PSD 72 is sent to the inspection device 74 as a two-dimensional position signal through the PSD processing circuit 73.
The inspection device 74 can communicate with the lens CPU 6 through a mount contact (not shown in FIG. 5 as through the mount contact). As described above, the lens CPU 6 is connected to the EEPROM 62 for writing the adjustment value.

The lens CPU 6 is preprogrammed with a sequence for adjusting the dead zone amount of the voltage driver 62, and also has a function as an adjusting operation control section. When the drive duty is specified from the inspection device side, this adjustment program sends the specified value directly to the voltage driver 62 for drive. The power supply to the interchangeable lens 1 is supplied from the inspection table 71 via the mount.

FIG. 6 is a flow chart showing the flow of the adjusting operation. In step (hereinafter referred to as S) 10, the shake correction lens 101 is driven to the movable center position. S20
Then, the output of the two-dimensional PSD 72 is monitored and stored as the initial position of the shake correction lens 101. In S30,
The X-axis side voltage driver is set to the standby state. This is because the characteristic is checked from the voltage driver on the X-axis side. In S40, the drive duty is increased from 0 by a small amount. S5
At 0, the output of the two-dimensional PSD 72 is monitored to determine whether or not the blur correction lens 101 has moved with respect to the initial position. If the shake correction lens 101 does not move, S4
The value is returned to 0, the drive duty is increased, and the drive is performed again. When it is confirmed that the shake correction lens 101 has moved, it is determined that the image sensor is out of the dead zone of the voltage driver, and the drive D at that time is determined.
is set to OFFset_duty_X and EEPR
In S70 written in the OM 62, the Y-axis side adjustment is performed in the same manner as in S30 to S60.

According to this embodiment, the dead zone amount of the voltage driver 61 is measured by each driver and stored in the EEPROM 62 as an adjustment value, and the offset value corresponding to the dead zone amount of the voltage driver 61 is corrected using this adjustment value. Since this is performed, it is possible to drive the lens accurately and stably regardless of the posture difference and the individual difference.

(Modifications) The present invention is not limited to the above-described embodiments, but various modifications and changes can be made, which are also within the scope of the present invention. For example, when the support structure of the shake correction lens 101 is spring-supported, the drive Du
The drive amount of the shake correction lens 101 may be plotted with respect to ty to obtain the dead zone width.

Further, although an example in which the two-dimensional PSD 72 is used to monitor the position of the shake correction lens 101 is shown, the invention is not limited to this, and for example, the lens position detection units 110x and 110y provided in the shake correction unit 100. May be used.

[0059]

As described in detail above, according to the first aspect of the invention, the dead zone amount information regarding the range of the instruction signal, which is the dead zone in which the driver section does not output the drive current even when the instruction signal is input, is stored. Since the dead zone amount information stored in the storage unit is a value that can be adjusted according to the individual difference of the driver unit, regardless of the individual difference of the driver unit,
Accurate dead zone amount information can be used, and stable driving can be performed.

According to the second aspect of the present invention, the control section transmits an instruction signal in consideration of the dead zone amount information stored in the storage section to the driver section, thereby reducing or eliminating the influence of the dead zone of the driver section. Therefore, the influence of the dead zone can be minimized and accurate driving can be performed.

According to the third aspect of the invention, the dead zone amount information includes X axis direction dead zone amount information and Y axis direction dead zone amount information corresponding to the X axis direction driver section and the Y axis direction driver section, respectively. Accurate driving can be performed regardless of the difference.

According to the fourth aspect of the invention, since the adjustment operation control section for controlling the operation necessary for performing the adjustment operation for storing the dead zone amount information as the adjustment value in the storage section is provided, the adjustment operation can be simplified. It can be carried out.

According to the invention of claim 5, the instruction signal is increased little by little, and the value corresponding to the instruction signal when the lens section starts to move is stored in the storage section as an adjustment value, so that it is accurate. The dead zone amount information can be stored.

According to the sixth aspect of the invention, when a plurality of drivers are provided, the adjustment is performed for each driver, so that the optimum dead zone amount information can be stored for each driver.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a blur correction lens and a camera including a lens driving device according to the present invention.

FIG. 2 is an enlarged view of a blur correction unit 100.

FIG. 3 is a block diagram of a portion related to blur correction control of a control unit 8.

FIG. 4 is a diagram showing how a control error changes according to the magnitude relationship between a frictional force and a feedforward amount.

FIG. 5 is a diagram showing an adjusting device for adjusting the amount of dead zone of a voltage driver 61 and a lens barrel being adjusted.

FIG. 6 is a flowchart showing a flow of adjustment operation.

FIG. 7 is a diagram showing an outline of a camera shake correction device.

FIG. 8 is a conceptual diagram illustrating a dead zone included in a voltage driver.

[Explanation of symbols]

1 interchangeable lens 1a Fixed tube 1b Moving barrel 2 camera body 6 lens CPU 7 Target position conversion unit 8 control unit 9 Body side CPU 10 First lens group 11 Second lens group 13 4th lens group 20 finder screen 21 Finder optical system 22 eyepiece 23 Quick Return Mirror 30 Angular velocity sensor 60 filters 61,65 voltage driver 62 EEPROM 63 Focal length detector 64 Subject distance detector 71 inspection table 72 Two-dimensional PSD 73 PSD processing circuit 74 Inspection device 75 Semiconductor laser light source 90 lens contact 91 Release switch 100 image stabilization unit 101 Image Stabilizer Lens (Third Lens Group) 102 lens frame 103 steel ball 104 biasing spring 110 Position detection device 120 VCM 130 Lock mechanism

Claims (6)

[Claims] 1. A movable lens unit, a drive unit that drives the lens unit, a control unit that controls the drive unit, and a drive that supplies the drive unit according to an instruction signal obtained by the control unit. A driver section that outputs a current; and a storage section that stores dead zone amount information regarding a range of the instruction signal that is a dead zone in which the driver section does not output the drive current even when the instruction signal is input, The dead zone amount information stored in the section is a value that can be adjusted according to individual differences of the driver section. 2. The lens driving device according to claim 1, wherein the control unit transmits an instruction signal in which the dead zone amount information stored in the storage unit is taken into consideration to the driver unit, whereby the driver unit A lens driving device characterized by reducing or eliminating the influence of the dead zone of. 3. The lens driving device according to claim 1, wherein the lens unit is movable in an X axis direction and a Y axis direction that are substantially orthogonal to each other, and the X axis direction and / or the Y axis direction. A blur correction lens that corrects an image blur by moving in an axial direction, wherein the drive unit and the driver unit are X-axis direction drive units corresponding to the X-axis direction and the Y-axis direction, respectively. An axial drive unit, an X-axis direction driver unit, and a Y-axis direction driver unit are provided, and the dead zone amount information is the X-axis direction driver unit, the Y-direction driver unit.
A lens driving device characterized in that it has X-axis direction dead zone amount information and Y-axis direction dead zone amount information respectively corresponding to the axial direction driver sections. 4. Any one of claims 1 to 3
The lens drive device according to item 1, further comprising: an adjustment operation control unit that controls an operation required to perform an adjustment operation that stores the dead zone amount information as an adjustment value in the storage unit. apparatus. 5. Any one of claims 1 to 4
A method of storing the dead zone amount information in the lens driving device as an adjustment value in the storage unit, wherein the instruction signal is increased little by little, and when the lens unit starts moving, A value corresponding to an instruction signal is stored in the storage unit as the adjustment value. 6. The method for adjusting a lens driving device according to claim 5, wherein when a plurality of the drivers are provided, the adjustment is performed for each driver. .