JPH08286096A - Lens controller - Google Patents

Abstract

PURPOSE: To attain zooming operation without causing blurring by driving a focusing lens on the basis of information on the in-focus position of the focusing lens with respect to the position of a variable power lens which is divided by a divisor within the movable range of the variable power lens. CONSTITUTION: A microcomputer (AF microcomputer) 116 for controlling AF detects the current position Zn of the variable power lens 102 by counting the number of step driving pulses supplied to a zooming motor 119. What position X on a locus table stored in the microcomputer 116 the variable power lens 102 exists at is calculated by X=Zn/ΔV...a. ΔV is the quotient when the number of step pulses equivalent to the movable range of the lens 102 is divided by the division number of the divisor. When the remainder (a) is not found, the data on the position of the focusing lens 105 equivalent to the position of an address X is read out of the locus table in the microcomputer 116. When the remainder (a) is found, an interior division point is read out. By setting the point as the in-focus position, the focusing lens 105 is driven.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lens control in a camera equipped with an inner focus type lens system.

[0002]

2. Description of the Related Art In recent years, video equipment such as a video camera has been remarkably developed, and in particular, in order to miniaturize the video equipment, an inner focus type lens system which can be miniaturized is widely adopted.

FIG. 2 shows a simple structure of a commonly used inner focus type lens system.

In the figure, 101 is a fixed first
Lens group 102, a second lens group (hereinafter referred to as a variable power lens) 102 that performs zooming, a diaphragm 103, a third lens group 104 that is fixed, and a focus adjustment function and a focus by zooming. A fourth lens group (hereinafter, referred to as a focus lens) having a so-called compensator function for correcting the movement of the surface (hereinafter referred to as a focus lens), 106a is an imaging surface of the image sensor 106.

As is well known, in the lens system configured as shown in FIG. 2, since the focus lens 105 has both a compensator function and a focus adjusting function, the image pickup surface 106a is focused even if the focal lengths are the same. The position of the focus lens 105 for that depends on the subject distance.

When the position of the focus lens 105 for focusing on the image pickup surface 106a is continuously plotted when the subject distance is changed at each focal length, FIG.
become that way.

While the variable power lens 102 is being driven to perform the variable power operation, the locus shown in FIG. 3 is selected according to the subject distance, and the focus lens 105 can be moved along the selected locus. If so, it becomes possible to perform a zooming operation without blurring.

On the other hand, in a so-called front lens focus type lens system in which the front lens is moved to adjust the focus, an independent compensator lens is provided for the variable power lens, and the variable power lens and the compensator lens are further provided. Are connected by a mechanical cam ring.

Therefore, for example, when a knob for a manual zoom is provided on this cam ring and the focal length is manually changed, the cam ring will follow the rotation of the knob no matter how fast the knob is moved, and the zoom ratio will change. Since the lens and the competing lens move along the cam groove of the cam ring, if the focus lens is in focus, the above operation does not cause blurring.

In the control of the inner focus type lens system having the above-mentioned characteristics, the plurality of locus information shown in FIG. 3 is stored in the lens control microcomputer in some form and changed from the focus lens. Generally, a locus is selected according to the position of the double lens, and zooming is performed while following the selected locus.

Further, since the position of the focus lens with respect to the position of the variable power lens is read from the storage element and is applied for lens control, the position of each lens must be read with a certain degree of accuracy.

As is clear from FIG. 3, in particular, when the variable power lens moves at a constant speed or a speed close to it, the inclination of the locus of the focus lens changes every moment due to the change of the focal length.

This indicates that the moving speed and the moving direction of the focus lens change every moment. In other words, the actuator of the focus lens makes a precise speed response from 1 Hz to several hundred Hz. It will have to be done.

It is becoming more common to use a stepping motor for the focus lens group of the inner focus lens system as an actuator that satisfies the above requirements.

The stepping motor rotates in perfect synchronization with the stepping pulse output from the microcomputer for controlling the lens and the stepping angle per pulse is constant, so that the stepping motor has high speed response and stopping accuracy. It is possible to obtain positional accuracy.

Further, when a stepping motor is used,
Since the rotation angle with respect to the step pulse number is constant, the step pulse can be used as it is as an increment type encoder, and there is an advantage that no special position encoder is added.

As described above, when the stepping motor is used to perform the zooming operation while keeping the focus, the locus information of FIG. It may be necessary to store it as a variable function), read trajectory information according to the position or movement speed of the variable power lens, and move the focus lens based on that information.

As described above, while the zoom tracking data stored based on the optical design value is created, in reality, this locus is designed due to an error in the focal length of each lens group. It is not the value. For this reason, in an actual video camera, among the stored data, work is performed to adjust which position of the zoom lens the tele end and the wide end correspond to.

As this method, conventionally, the movable range of the variable power lens from the tele end to the wide end, that is, the stroke is kept as designed, and the focus lens at the tele end and the wide end at the adjustment distance (for example, ∞) is combined. There is known a method in which a position where the focal position difference (balance) also becomes a design value is obtained and the positions are set to the tele end and the wide end. This method will be referred to as constant stroke adjustment here.

Further, the difference between the focusing positions of the telephoto end and the wide end focus lens (balance) is used as a design value, and the focus lens of the middle (intermediate focal length) is the focus lens as shown in FIG. In the above, a method is known in which a zoom lens position is obtained such that the amount of movement from the upward position and the focus lens position at the tele end becomes a design value, and the positions of the variator at the tele end and the wide end are set. . This method will be referred to as tele-middle tracking adjustment here.

Next, referring to FIG. 4, when the constant stroke adjustment and the tele-middle tracking adjustment are carried out, the tele end position and the wide end position become larger than the designed values in the middle focus lens position. The situation when the lens group having an error in the direction is used will be described.

In FIG. 4, the horizontal axis shows the position of the variable power lens (that is, the focal length), and the vertical axis shows the position of the focus lens. In the figure, the trajectory Sb indicated by the dotted line corresponds to the design value. On the other hand, it is assumed that the actual focus lens shows a locus Sa like a solid line due to manufacturing error or the like.

At the distance (eg, ∞) here, the tele end Ta
And the focus position difference of the focus lens at the wide end Wa is 0
And

If the trajectory is as designed,
When performing tele-middle tracking adjustment, the point'on the map is the starting point for the adjustment. From this point, the focus lens is lowered in the figure by the amount A of movement of the focus lens that is the designed value. This position is'.

From this state, the variable power lens is moved to obtain the in-focus position, which is the variator position at the tele end.

Further, in this example, since the difference between the focus positions of the focus lens at the wide end and the tele end is 0 as described above,
Similarly, the position where the variable power lens is moved and focused is the variator position at the wide end.

In the case of constant stroke adjustment, the method is to adjust the stroke and the balance to a predetermined value regardless of whether the trajectory is the designed value or the trajectory having a certain error indicated by the solid line. Also, the tele end position becomes, and the wide end position becomes.

On the other hand, when performing the tele-middle tracking adjustment with the lens having the locus Sa shown by the solid line, the focus lens is positioned by lowering the focus lens by a design value A from the starting point of the adjustment. . From here, similarly to the above, as a result of moving the variable power lens to the in-focus position, is the tele end and is the wide end.

By the above adjusting operation, when there is an error (solid line) such that the height of the "mountain" of the locus rises with respect to the locus of the design value (dotted line) as shown in FIG. When the constant stroke adjustment is performed, the tele end becomes the wide end, and when the tele-middle tracking adjustment is performed, the tele end becomes the wide end.

FIG. 5 shows the information addresses of the locus data when the telephoto end and the wide end are determined by performing the constant stroke adjustment when the trajectory of the design value and the actual trajectory Sa are substantially the same. Here, data is shown when the stroke of the variable power lens is equally divided into, for example, 12.

Therefore, if the position of the variable power lens is at Zn (on the horizontal axis) in the figure, and this is the address 11, the focus position is the position Fa at the 11'th address (on the vertical axis) of the focus lens. .

In this way, when the focus position of the focus lens is read from the position of the variable power lens, it is necessary to accurately detect where the variable power lens is located on the locus data table.

However, the stroke of the variable power lens (the number of step pulses of the step motor required to move the variable power lens over the entire moving range) is a multiple of the equal division number 12 of the moving range of the variable power lens. If not, an error occurs between the locus data table and the actual zoom lens position, and even if the zoom lens is actually in Zn, on the locus data table Wa to Ta '(the number of pulses corresponding to the stroke is Focus point Fa 'at address 11 that is a multiple of 12)
Therefore, the true focus point and the focus point read from the trajectory data table are different, and this error ΔB (= Fa′−Fa) causes blurring during zooming.

FIG. 6 is a locus when the tele end and wide end are determined by the tele-middle tracking adjustment when there is an error between the design value locus (dotted line) Sb and the actual locus (solid line) Sa. Indicates the information address of the data.

Here, the distance from the middle point Ma to the tele end point Ta is almost the same as the design value.

However, the stroke of the variable magnification lens from the wide-angle end point Wa to the middle point Ma is ΔZwa
There is a difference.

Therefore, if the stroke of the variable power lens from Wa to Ta is divided into 12 equal parts, there is an error in the stroke of the variable power lens between the design value and the actual value, so that the error is from Wa to Ta. It will be divided into strokes.

However, since the values from Ma to Ta almost match the design values originally, if the errors are distributed, the distributed errors will occur, but the slope of the peak of the locus is steep. , The distributed error appears as a large blur. This error appears as a deviation between Fa ′ and Fa, and this error ΔB (= Fa′−Fa) causes blurring during zooming.

On the other hand, since the inclination from Wa to Ma is gentle, if the error is absorbed during this period, a large blur does not occur.

FIG. 6 shows a state in which the locus data tables are distributed in this way. Even here,
Similar to the constant stroke adjustment, since the addresses are distributed from Ma to Ta at equal intervals based on the design value, an error occurs unless the design value is a multiple of the division number, as described with reference to FIG. This causes blurring.

[0041]

When the stroke (pulse number) of the variable power lens is divided and the focus lens position is read from the previously stored locus data table, if the divisor of the stroke number is not the division number. However, there is a problem that an error occurs between the actual position of the variable power lens and the position on the locus data table, resulting in blurring during the zoom operation.

Therefore, an object of the present invention is to provide a lens control device capable of realizing a zoom operation without blur by compensating for an error between the actual position of the variable magnification lens and the position on the locus data table. Especially.

[0043]

In order to solve the above-mentioned problems, according to the invention described in claim 1 of the present application, a variable power lens for performing a variable power operation and the variable power lens movement. A focus lens for correcting the movement of the focal plane at the time, the variable power lens, and a driving unit for moving the focus lens independently of each other in parallel with the optical axis,
The focus position of the focus lens with respect to the zoom lens position is stored according to the subject distance, and the information stored in the storage unit is about the movable range of the zoom lens. The lens control device is the focus position of the focus lens with respect to the variable power lens position divided by a number.

According to the second aspect of the present invention, a variable power lens for performing a variable power operation, and a focus lens for correcting the movement of the focal plane when the variable power lens is moved, Drive means for moving the variable power lens and the focus lens independently of each other in parallel with the optical axis,
Storage means for storing the focusing lens focus position with respect to the zoom lens position divided by a divisor of the movable range of the zoom lens according to the subject distance, and the storage unit when the zoom lens is driven. And a control means for controlling the drive of the focus lens based on the stored information read from the means.

According to the invention of claim 3 of the present application, a variable power lens for performing a variable power operation, and a focus lens for correcting the movement of the focal plane when the variable power lens is moved, Drive means for moving the variable power lens and the focus lens independently of each other in parallel with the optical axis,
The focus position of the focus lens with respect to the zoom lens position is stored according to the subject distance, and the information stored in the storage unit is stored in the middle position of the zoom lens. The lens control device is a focus position of the focus lens with respect to the variable power lens position, which is divided by a divisor of the stroke of the side position.

According to the invention of claim 4 of the present application, a variable power lens for performing a variable power operation, and a focus lens for correcting the movement of the focal plane when the variable power lens is moved, Drive means for moving the variable power lens and the focus lens independently of each other in parallel with the optical axis,
Second with respect to the position of the variable power lens, which is divided by a divisor of the stroke from the middle position of the variable power lens to the tele position.
Storage means for storing the in-focus position of the lens group according to the subject distance, and control means for controlling the drive of the focus lens based on the storage information read from the storage means when the variable magnification lens is driven. The lens control device is provided with.

[0047]

According to the first and second aspects of the present invention, based on the information of the focus lens focus position with respect to the zoom lens position, which is divided by the divisor of the movable range of the zoom lens, the actual zoom lens position is changed. An error between the double lens position and the position on the locus data table can be compensated, and a zoom operation without blur can be realized. To provide a lens control device.

According to the third and fourth aspects of the invention, the focus position of the focus lens with respect to the variable lens position divided by the divisor of the stroke from the middle position of the variable power lens to the telephoto side position. It is possible to compensate for the error between the actual position of the variable magnification lens and the position on the locus data table based on the above information, and it is possible to realize a zoom operation without blur.

[0049]

Embodiments of the lens control device according to the present invention will be described in detail below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing an embodiment in which the lens control device of the present invention is applied to a video camera.

In FIG. 1, 101, 102, 103, 1
Reference numerals 04 and 105 are elements constituting an inner focus type lens system, and each of them is a fixed front lens group, a second lens group (referred to as a variable power lens) for performing zooming, an aperture, and a fixed lens. It is a third lens group and a fourth lens group (referred to as a focus lens) having both a competition function and a focusing function.

The image light transmitted through this lens system is imaged on the image pickup surface 106a of the image pickup element 106 and converted into a video signal by photoelectric conversion.

Reference numeral 107 is an amplifier (or impedance converter), and reference numeral 108 is a camera signal processing circuit for performing a predetermined process on the image pickup signal output from the amplifier 108 to convert it into a standardized television signal. The amplified video signal is amplified to a specified level by the amplifier 109, and L
After being processed by the CD (liquid crystal) display circuit 110, the photographed image is displayed on the LCD 111 as an electronic viewfinder.

On the other hand, the video signal amplified at 107 is sent to the aperture control circuit 112 and the AF evaluation value processing circuit 114.

In the aperture control circuit 112, the IG driver 113 and the IG meter 114 are driven to control the aperture 103 and adjust the light amount so that the video signal input level becomes equal to the predetermined reference signal level. There is.

In the AF evaluation value processing circuit 115, in response to the gate signal from the distance measuring frame generating circuit 117, only the video signal corresponding to the distance measuring frame (not shown) in the image pickup screen is taken out and the high pass filter is used to extract the video signal. Only a high-frequency component that changes according to the focus state is extracted and supplied as an evaluation value of the focus state to an AF microcomputer described later.

Reference numeral 116 is a microcomputer for AF control (hereinafter referred to as an AF microcomputer) as a control means and a storage means of the present invention, which corresponds to the strength of the AF evaluation signal supplied from the AF evaluation value processing circuit 115. The drive control of the focus lens 105 and the ranging frame control for changing the ranging area are performed.

Further, the AF microcomputer 116 communicates various control information with a system control microcomputer (hereinafter referred to as "syscon") 122 that controls the entire video camera system. For example, the syscon 122 uses A / D conversion or the like. The read zoom switch 123 (a unitized zoom SW outputs a voltage according to the rotation angle and direction of the operating member.
(Variable speed zoom operation in the wide direction is performed), zooming operation information during zooming controlled by the AF microcomputer 116, zooming operation information, and the like are exchanged with each other.

Reference numerals 118 and 120 respectively apply drive energy to the zoom motor 11 for driving the variable power lens in accordance with the drive commands of 102 and 105 output from 116.
9. Focus motor 121 for driving focus lens
A zoom driver and a focus driver for outputting to.

The driving method of the motor will be described below assuming that the lens driving motor is a stepping motor.

The zoom motor 119, the focus motor 121, the zoom driver 118, and the focus driver 120, which are constituted by these stepping motors, constitute the driving means of the present invention.

The AF microcomputer 116 determines the drive speeds of the zoom motor 119 and the focus motor 121 by program processing, and uses them as the rotation frequency signals of the stepping motors to drive the zoom motor 119.
18. Send to the focus driver 121 for driving the focus motor 121.

The drive / stop command for each motor 119 and 121 and the rotation direction command for each motor are given to each driver 11.
I am sending it to 8, 120.

The drive / stop signal and the rotation direction signal are determined mainly by the state of the zoom switch unit 123 for the zoom motor, and for the focus motor by a process in the microcomputer 116 during AF and zoom. I am accepting orders.

That is, when the zooming operation is not performed, the focus lens is driven so that the AF evaluation value reaches a peak based on the AF evaluation value output from the AF evaluation value processing circuit 115.

During the zooming operation, the zoom lens is driven according to the driving of the zoom lens, the locus shown in FIG. 3 is specified based on the object distance, and the focus lens 105 is driven so as to trace the locus. By doing so, it is possible to perform a zoom operation without blur.

When the subject changes during the zooming operation and the object is out of focus, the focus lens drive amount based on the AF evaluation value from the AF evaluation value processing circuit 115, that is, the blur information is added. By driving the focus lens 105 on the basis of the information obtained, it is possible to maintain the in-focus state even when the out-of-focus state occurs during the zooming operation.

Further, the motor driver sets the phases of the motor excitation phases of the four phases to the forward rotation and reverse rotation phases according to the rotation direction signal, and according to the received rotation frequency signal.
By outputting while changing the applied voltage (or current) of the four motor excitation phases, the output to the motor is turned ON / OFF in response to the drive / stop command while controlling the rotation direction and rotation frequency of the motor. It is off.

FIG. 7A is a flow chart showing the processing operation of the data reading method from the trajectory data table in the AF microcomputer 116 when the constant stroke adjustment is performed as shown in FIG.

In step 701, the current position Zn of the variable magnification lens is counted by a counter in the AF microcomputer 116 for the number of step driving pulses supplied to the zoom motor 119. By incrementing or decrementing when driving in the other direction, it is always detected as an absolute position with respect to the reference position of the variable power lens.

Step 702 calculates which side on the trajectory table stored in the AF microcomputer the variable power lens is located.

That is, ΔV is a quotient when the number of strokes (that is, the number of step pulses of the stepping motor) corresponding to the movable range of the variable power lens 102 is divided by a divisor m. The calculation in this step is as follows: X = Zn / ΔV ... a X: Table position (address) of the zoom lens Zn: Current position of the zoom lens Zn ΔV: Stroke corresponding to the movable range of the zoom lens 102 Quotient when a number is divided by a divisor m: a remainder If step 703 has a remainder in the operation of step 702 (whether a = 0 or not), that is, the current position of the variable magnification lens 102. Is divided by one of the m divided areas by the number of equivalent strokes (step pulse number), it is determined whether or not the division is possible.

The fact that there is no remainder in the processing of step 703 indicates that the variable power lens 102 is on the locus data defined on the locus table.

If there is no remainder, the position data Fx of the focus lens 105 corresponding to the position of the address X which is the current position of the variable magnification lens 102 is read from the trajectory table in step 704.

When there is a surplus, the variable power lens 102 is not on the locus defined on the locus table, and the variable power lens is positioned between the address X and the address X + 1 of the locus table in step 705. Is.

Therefore, the focus position of the focus lens to be read is as follows: Fx and Fx + 1 on the table are "a" and "(X +
1) -X ”is the point internally divided.

Then, in step 706, the table reading focus position is obtained when Fn is the variable magnification lens position Zn. The state of these calculations is shown in FIG.

As described above, the locus data table obtained by dividing the stroke of the variator lens by a divisor is used as the microcomputer 11
By having it in 6, it is possible to eliminate the reading error of the locus data table and prevent blur during the zoom operation.

That is, based on the information of the focus position of the focus lens with respect to the zoom lens position divided by a divisor of the movable range of the zoom lens, the actual zoom lens position,
An error between the position on the trajectory data table and the position can be compensated, and a zoom operation without blur can be realized.

(Second Embodiment) Next, the second embodiment of the present invention will be described.
An example will be described.

FIG. 8 is an operation flow of a method of reading from the trajectory data table in the AF microcomputer 116 when the tele-middle tracking adjustment is performed as shown in FIG.

The step 801 always detects the current position Zn of the variable magnification lens by incrementing or decrementing the step pulse number supplied to the zoom motor.

Step 802 shows the current zoom lens position Z.
It is determined whether n is on the tele side or the wide side from the middle position Ma.

If it is on the wide side, step 803 calculates which side of the locus data table the variable magnification lens is on.

X = Zn / ΔV ′ ... a X: Table position (address) of the variable power lens Zn: Current position of the variable power lens Zn ΔV ′: The number of strokes corresponding to the movable range of the variable power lens 102 is approximately Quotient a ': remainder when divided by the number of divisions m' (ΔV '= stroke / m') That is, ΔV 'is a value obtained by dividing the number of strokes of the zoom lens from the wide to the middle by a constant m'. .

This value is an error between the actual stroke number and the stroke number of the variable magnification lens between the wide and middle of the design value, which occurs due to the variation between the design value and the actual lens during the tele-middle tracking adjustment. Is to absorb.

Steps 804 to 806 are the same as the processing performed in steps 703 to 705 of FIG.

If it is telescopic in step 802, in step 807 which side on the locus data table the variable magnification lens is located is calculated.

That is, ΔV ″ is a quotient obtained by dividing the stroke number of the middle to tele variator by the divisor m ″.

The processing from step 808 to step 810 is the same as the processing from step 703 to step 705 in FIG.

Then, in step 811, the focus position of the focus lens 105 read from the locus data table when Fn is the zoom lens position Zn is obtained.

As described above, the locus data table in which the number of strokes is divided by a divisor is provided in the AF microcomputer 116 even only in the portion where the inclination of the cam locus from the middle position to the tele end position of the variable power lens is steep, and thus the locus is stored. It is possible to eliminate reading errors in the data table and reduce blur during zooming.

That is, based on the information of the focus position of the focus lens with respect to the variable lens position divided by the divisor of the stroke from the middle position of the variable lens to the telephoto side position, the actual variable lens position And the position on the trajectory data table can be compensated, and a zoom operation without blur can be realized.

[0094]

As described above, the claims 1 and 2 of the present application
According to the invention described in 2, the locus information table divided by the divisor of the movable range stroke of the variable power lens is stored in the microcomputer, and the in-focus focus position of the focus lens with respect to the variable power lens position is read from the table. As a result, table reading errors can be eliminated and blurring during zooming can be reduced.

According to the third and fourth aspects of the present invention, the locus information table divided by the divisor of the stroke of the tele variator lens from the steep middle of the cam locus table is stored in the microcomputer. By reading the in-focus focus position with respect to the variator position from the table, it is possible to eliminate the table reading error from the middle to the tele and to reduce the blur during zooming.

Further, no special configuration is required, the amount of data is small, and highly accurate and high-quality zooming operation is possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment when a lens control device according to the present invention is applied to a video camera.

FIG. 2 is a diagram showing a configuration of an inner focus type lens system.

FIG. 3 is a diagram showing, for each object distance, a locus obtained by plotting a focus position of a focus lens according to a variable magnification lens position.

FIG. 4 is a diagram for explaining a constant stroke adjustment operation which is an example of an adjustment operation between the trajectory data and the variable power lens position.

FIG. 5 is a diagram for explaining a tele-middle tracking adjustment operation, which is an example of an adjustment operation between the trajectory data and the variable power lens position.

FIG. 6 is a diagram for explaining an error that occurs between a design value trajectory and an actual trajectory.

FIG. 7: AF when constant stroke adjustment operation is performed
9 is a flowchart illustrating a method of reading from a locus data table in a microcomputer.

FIG. 8 is a flowchart illustrating a method of reading from a trajectory data table in the AF microcomputer when a tele-middle tracking adjustment operation is performed.

[Explanation of symbols]

 102 variable magnification lens 105 focus lens 106 image sensor 115 AF evaluation value processing circuit 116 AF microcomputer 118 zoom driver 119 zoom motor 120 focus driver 121 focus motor

Claims (4)

[Claims] 1. A variable power lens for performing a variable power operation, a focus lens for correcting movement of a focal plane when the variable power lens moves, a variable power lens and a focus lens, respectively. And a storage unit for storing the focusing position of the focus lens with respect to the variable power lens position according to the subject distance. The stored information is divided by a divisor of the movable range of the variable power lens, with respect to the variable power lens position,
The lens control device is the focus position of the focus lens. 2. A variable power lens for performing a variable power operation, a focus lens for correcting the movement of the focal plane when the variable power lens moves, the variable power lens, and the focus lens, respectively. Driving means for independently moving in parallel with the optical axis, and storing the focus lens focus position with respect to the zoom lens position divided by a divisor of the movable range of the zoom lens according to the subject distance. A lens control device comprising: the storage means described above; and a control means for controlling the drive of the focus lens based on the stored information read from the storage means when the variable magnification lens is driven. 3. A variable power lens for performing a variable power operation, a focus lens for correcting the movement of the focal plane when the variable power lens moves, a variable power lens, and the focus lens, respectively. The driving means for independently moving in parallel to the optical axis, and the storage means for storing the focus position of the focus lens with respect to the zoom lens position according to the object distance, the storage means The stored information is the focus position of the focus lens with respect to the variable power lens position, which is divided by a divisor of the stroke from the middle position of the variable power lens to the tele position. . 4. A variable power lens for performing a variable power operation, a focus lens for correcting the movement of the focal plane when the variable power lens moves, a variable power lens, and the focus lens, respectively. Drive means for independently moving in parallel to the optical axis; and a second means for dividing the zoom lens position divided by a divisor of the stroke from the middle position of the zoom lens to the tele position.
A storage unit that stores the focus position of the lens group according to the subject distance; and a control unit that controls the drive of the focus lens based on the storage information read from the storage unit when the variable power lens is driven. , A lens control device.