JP2814239B2 - Lens control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Technical field   The present invention relates to a lens control device, and more particularly, to a lens control device.
Variable power lens group and focusing lens group arranged on one optical axis
Lens control device that drives and controls a variable power optical system
Is what you do. (B) Conventional technology   The zoom lens position is the same as the image formation position even when zooming.
No deviation (so-called focus shift or defocus)
This eliminates the hassle of adjusting the focus for each zooming operation.
On the other hand, the F-number is larger than the single focus lens.
Because it is dark, for example, with a single-lens reflex finder
Some skill is needed for focus adjustment (focusing operation)
You. In recent years, AF has been adopted for cameras, and this problem has been solved.
By doing so, you can demonstrate the original mobility of the zoom lens
Becomes, the operator (user) composes according to the drawing intention
You can focus on your decisions
Extremely improved operability.   In general, focusing (focusing operation) of a zoom lens
Is a focusing lens provided in a part of the zoom optical system.
This is done by moving the group. And zoomlen
Is the same for the same subject distance in the entire zoom range.
The moving distance of the focusing lens group is almost the same
Below, this is called “equivalent movement”).
Therefore, the subject distance scale should be adjusted for the focusing lens group.
Attached to the moving member (distance ring), while adjacent to this
A simple structure that simply attaches an index to the fixed ring
Can realize the subject distance display with
It is not necessary to change the subject distance scale according to the
There are advantages.   However, due to the lens configuration of the zoom optical system,
Are different, but the inner focusing method and rear
With the focusing type zoom lens, the above-mentioned
When optical design is performed under the condition that
And the focus on the wide-angle side
The moving amount (steering amount) of the lens group becomes unnecessarily large
There was a problem.   This also increases the outer diameter of the lens,
There is also a problem that the weight of the lens and the lens barrel increases.   In this way, the zoom lens depends on the combination with the AF function.
Operability has been improved, but with a zoom lens
Since you cannot escape from the above-mentioned conditions of equal displacement,
The problem that it is difficult to realize impact and cost reduction
Was still left.   Accordingly, the present applicant has proposed a flash that can solve the above-described problems.
Invention relating to the focal lens control device (hereinafter referred to as “the prior application
”) Was first proposed as Japanese Patent Application No. 62-013345.
I thought.   In other words, the prior invention is arranged on the same optical axis.
Of a variable power optical system consisting of a variable power lens group and a focusing lens group
A subject ranging from a close distance to an infinite distance with the focusing lens group
From the closest position on the optical axis corresponding to the distance to the position at infinity
After setting the in-focus position between
The minimum focal length and the longest focal length
A second focal point from any first focal length to the focal length
Focusing position on the same subject with updating to distance
In a varifocal lens that causes a displacement,
A focal length detecting means for detecting a focal length;
Focus lens group position detection for detecting the position of the lens group on the optical axis.
Output means and an output of the focal length detecting means.
Above the infinity position of the focusing lens group at a distance
The maximum feed amount calculator that calculates the feed amount to the nearest position
Step, the maximum feeding amount calculating means, and the focusing lens group position
Receives the output of the detection means and calculates the ratio of these outputs
Means for calculating the proportional constant,
And the maximum feeding amount calculating means and the focusing lens group
Receive the output of the position detection
The amount of image position deviation from the in-focus position caused by the new
A focusing correction calculating means for calculating as a correction value;
Focusing drive means for driving a lens group;
Movement amount monitoring means for generating a signal corresponding to the movement amount;
Output of the movement amount monitoring means and the focus correction calculating means
Drive each focusing lens group to the focusing position
Focus control means for controlling the zoom lens group
Variable-power driving means for driving the camera and separately provided starting means
To control the above-mentioned variable-power driving means in response to the start signal
Control means for controlling the focal length of the entire zoom optical system.
Configuration to automatically correct the imaging position shift due to update
Have been.   According to the invention of the prior application configured as described above, the lens optics
The system itself has a very simple configuration and is small, lightweight and inexpensive
At the same time, the entire lens control device is similarly compact, lightweight and inexpensive.
While the variable power lens group has an arbitrary first focal length.
To the second focal length to update the focal length of the entire system
Even if you do
Can sometimes be corrected and remain in focus,
Get the equivalent of a zoom lens
be able to.   By the way, in the above-mentioned prior invention, the variable power drive and the
Several methods are conceivable for performing the focus drive.   First, the zoom lens group is intended at once from the focused state
To the desired focal length (total focal length)
A method that drives only the focusing lens group to correct misalignment,
Second, after driving the variable power lens group by a predetermined amount from the focused state
The drive is temporarily stopped, and the
Drive only the focusing lens group to compensate for slight
After that, the above-mentioned variable power drive and focus drive are repeated again.
Method, thirdly, similar to the second method, but during focusing drive
A method in which the variable-power driving is performed in parallel with the above-mentioned method can be considered.   The first method is the one that can perform variable speed driving most quickly.
During zooming, for example, single-lens reflex
If you are observing with a viewfinder,
There are practical difficulties because the image is difficult to see. The second one above
In the formula, the variable power drive and the focus drive are performed alternately in steps.
Therefore, although the viewfinder observation image looks good,
More time to reach the desired focal length?
There is a slight disadvantage in that In the case of the above third method
In this case, the viewfinder observation image looks
And the desired focal length is reached more than the second method.
Has the advantage of shortening the time required for
As will be described in detail, the focal length data at a certain point
The correction operation is performed based on the data and focus driving is performed immediately.
However, the focal length may change during the calculation and focusing operation.
The focal length at the time when the driving of the zoom lens is stopped
Will not be performed. Also strange
Externally operable to instruct double operation
When the pressing operation is released during the above step operation
Indicates that the zooming operation is completed without correcting the imaging position shift.
There is a risk of doing this. (C) Purpose   The present invention has been made in view of the above circumstances,
The time required for zooming operation is as short as possible, and zooming drive
The image forming position shift does not substantially occur, and
No matter what point the zooming operation of the display means is stopped at,
No alignment occurs, and correction of the imaging position shift is being performed.
For example, a drive signal output from an automatic focusing device
Focus driving means can be reliably prevented from
To provide a lens control device capable of performing reliable zooming
is there. (D) Configuration   In order to achieve the above object, the first invention (claim
The invention according to the first aspect of the invention is arranged on the same optical axis.
Power system consisting of a variable power lens group and a focusing lens group
A lens control device for driving and controlling the focusing lens;
Focusing drive means for driving the lens group, and
Moving variable magnification driving means, on the optical axis of the focusing lens group
Focusing lens group position detecting means for detecting the position of the
Variable power lens group for detecting the position of the double lens group on the optical axis.
The position detection means and the variable magnification driving means have the variable magnification
Drive instruction signal for instructing drive or stop of the lens group or
Externally operable variable-power drive instruction means for giving a stop instruction signal
And the variable magnification lens group is driven by the variable magnification driving means.
The focusing lens group and the variable power lens
By performing a predetermined calculation based on the position of the group, the zoom lens group
Calculate the correction amount of the focusing lens group corresponding to the position
In order to drive the focusing lens group according to the correction amount of
Focusing correction control means for controlling the focus driving means;
While the positive control means controls the focusing drive means,
Another control means provided controls the focus driving means.
Control prohibition means for prohibiting the driving instruction.
The variable power driving the variable power lens group by a signal
When the drive means receives the stop instruction signal, the variable power lens
After stopping the zoom lens group,
The focus lens group is moved to a position corresponding to the correction amount.
The focus correction control means controls the focus lens through the focus drive means.
Characterized in that it is configured to move a group of
And   Second invention (the invention described in claim 2)
Are the variable power lens groups and the focusing lens
Lens control device that drives and controls the variable power optical system consisting of lens groups
Focusing driving means for driving the focusing lens group
And a variable power driving unit for driving the variable power lens group;
Focusing lens that detects the position of the focusing lens group on the optical axis
Group position detecting means; and a position of the variable power lens group on the optical axis.
Lens unit position detecting means for detecting the position of the zoom lens;
Instructs the moving means to drive or stop the zoom lens group.
External operation to give a driving instruction signal or a stop instruction signal
Operable zoom drive instruction means and the zoom lens group
While the focusing lens is being driven by the variable-power driving means,
Calculation based on the positions of the zoom lens group and the zoom lens group
Focus lens corresponding to the position of the zoom lens group.
The correction amount of the lens group is calculated, and the focusing
Focusing control for controlling the focusing drive means to drive the lens group
A corrective control means and the focus correction control means
Other control means provided separately while controlling the step
Control prohibition hand that prohibits control of the focus drive means
And the output of the zoom lens group position detecting means is changed by a predetermined amount.
Means for monitoring the amount of movement of the zoom lens group for monitoring whether or not
And the variable power lens unit is provided by the variable power driving means.
During the movement, a predetermined amount is set by the variable magnification lens group movement amount monitoring means.
Operates the focus correction control means each time it is determined that the focus has changed
And moving the focusing lens group.
Things.   FIG. 1 is a block diagram showing the overall configuration of the present invention.
You. In FIG. 1, 1 is the optical axis of the variable power optical system, and 2 is this optical axis.
The optical axis is arranged on the optical axis 1 so as to be movable along the optical axis 1.
Variable as a varifocal lens that constitutes a variable power optical system
In the double lens group, 2a, 2b, 2c, 2d, and 2e
A first group lens, a second group lens,
They are a third group lens, a fourth group lens, and a fifth group lens.
Then, with the first group lens 2a and the second group lens 2b,
Construct a focusing lens group as a focusing lens group
You. The first lens group 2a and the second lens group 2b are formed.
Focal length is f_FIt is. The first and second group lenses 2a, 2
b, and varies with the third group lens 2c to the fifth group lens 2e.
A double lens group 2 is formed, and its focal length is f_ZIt is. Also
The total focal length of the variable power optical system comprising the variable power lens group 2
Is f. 3 is the film surface, 4 is the focal length f of the entire system.
The focal length on the telephoto side as the longest focal length (hereinafter simply referred to as
Side ") and the wide-angle focus as the shortest focal length
The distance up to the distance (hereinafter simply abbreviated as "wide side")
Drive the zoom lens group 2 to set the desired focal length
Variable magnification motor M as variable magnification driving means_ZAnd not shown
Variable magnification drive unit consisting of mechanism unit, 5 from infinity to close
Infinity position (光 position) on the optical axis 1 corresponding to the subject distance
The first lens group 2a and the
And the second group lens 2b (in detail, the first group lens
With the distance between the lens unit 2a and the second group lens 2b kept constant, the optical axis
Focus) as a focus driving means
Motor M_FAnd a focus drive consisting of a mechanism (not shown)
The moving parts, 6 and 7, are respectively the first group lens 2a and
The focus drive unit 5 is driven together with the second group lens 2b.
Of these, 6 is the slit disk 6a that is driven to rotate.
Proportional to the rotation speed from the photo interrupter 6b
First lens 2a and second lens
A focus counter for detecting the amount of movement of the 2b on the optical axis 1;
7 is on the optical axis of the first group lens 2a and the second group lens 2b.
The voltage proportional to the position of the focus position information S_xAs
Focusing lens as output focusing lens group position detecting means
Group position detector (hereinafter abbreviated as “FPM”), 8
Driven by the variable magnification drive unit 4 together with the lens group 2 to focus on the entire system.
The voltage proportional to the distance f is calculated as the focal length information Z_pOutput as
Zoom lens group position as a variable zoom lens group position detecting means
Detector (hereinafter abbreviated as “ZPM”), 9 is the above focal length
Information Z_pAfter receiving A / D conversion, this Z_pPosition in
First lens unit 2a and second lens unit from the position to the closest position
(The amount of feed) F_pxMaximum operation
The maximum feed amount calculation unit as output amount calculation means, 10
Output F of feeding amount calculation unit 9_pxAnd FPM7 focus position information
Output S as_xAnd the output S_xAfter A / D conversion
By calculating these ratios, the proportional constant Cf_pOutput proportional constant
Proportional constant calculation unit as calculation means, 11 is the above three outputs
F_px, Cf_p, S_xCorrection amount D for receiving and focusing_fpAct
The focus correction calculation unit as focus correction calculation means for calculating
Output Df of focus counter 6_cAnd the above focus correction
Output Df corresponding to the correction amount of the calculation unit 11_pFocus on receiving
Focus control as focus control means for controlling the drive unit 5
It is your part.   It should be noted that the maximum feed amount calculation unit 9 and the proportional constant calculation unit 10
Focus correction is performed by the focus correction calculation unit 11 and the focus control unit 12.
It constitutes the primary control means. 13 to 15 constitute the starting means
And 13 and 14 are both external operations that activate the scaling operation.
As a variable-power drive instruction means consisting of possible pushbutton switches
13 are magnification change switches (hereinafter referred to simply as “magnification switches”).
14 is the down switch.
(Hereinafter simply referred to as “down switch”), 15 are these
Receiving the output of switches 13 and 14_ZHow to rotate
After determining the direction, it consists of a start instruction signal and a stop instruction signal
The drive direction determination unit 16 that outputs a start signal (STR) is
Motion signal STR and output F_pxTo control the variable power drive 4
This is a variable magnification control unit. Note that + V indicates a power supply,
Indicates only the main signal.   In FIG. 1, the configuration up to this point is the same as the configuration of the prior invention.
As will be described later in detail, the device of the present invention
Further, the output of the focus correction calculation unit 11 allows the input terminal 11
Outputs the signal input from a to the focus control unit 12.
Control means for prohibiting this output.
Is different from the prior invention device in that the
Wrong.   FIG. 2 is a graph showing the characteristics of the device of the invention of the prior application.
Focal length f to be set and the focusing lens group (first
With respect to the subject distance D of the group lens 2a and the second group lens 2b).
The corresponding feeding amount (moving amount) is calculated for each representative subject distance D.
The vertical axis indicates the change of the focal length f of the entire system, and the horizontal axis indicates infinity.
Focusing lens based on focus position for distance
It shows the amount of feeding of the group. In this example, the tele position
Is f = 135 mm, and the wide position is f = 35 mm.
You.   In FIG. 2, reference numerals 17 to 22 denote focusing curves.
, 6.0 m, 3.0 m,
Focal length information Z when placed at 2.0m, 1.5m, 1.2m_pTo change
From the infinity position of the focusing lens units 2a and 2b
This shows a change in the feeding amount up to the in-focus position. That is,
The subject distance D is C₀, C₁, C_TwoAre determined at the time of design
Is the focal length information Z_pAnd Focusin
Glens group position information S_xFrom the following equation
be able to. D = (C₀・ Z_p+ C₁) ・ S_x+ C_Two                  (1)   Therefore, the focusing curve 22 shown in FIG.
The closest focusing curve, especially this closest focusing curve 22_px
And That is, the closest subject distance D is D₀And S_x=
F_pxEquation (1) is   And by separating the constants,
You.   Further, in equation (3), C₁₁= C₁, C_{twenty two} (D₀) = C_Two, C₃₃(D₀) = C_ThreeIf so, Is obtained.   FIG. 3 shows the operation of the apparatus shown in FIG.
FIG. 2 is a graph in which a part of FIG.
You.   In FIG. 3, Z_{p (i)}, S_(i)And F_{p (i)}Each
Focal length information immediately before performing the zooming operation (first focal length
Information) Z_p, Focus position information S_xAnd Z above_{p (i)}In
The amount of movement from the focusing curve 17 of Keru to the closest focusing curve 22
(Maximum payout) and Z_{p (e)}, F_{p (e)}And Df_p
Is a predetermined time after the variable-power drive unit 4 starts operating.
Distance information (e.g., second focal length information
Information), Z above_{p (e)}Focusing curve 17 to focusing curve 22 at
The amount of movement and the amount of focus
You. In other words, the proportional constant Cf immediately before the scaling operation_pAnd the equation (5)
Then, the closest focusing curve at this time is given by equation (6).
You.   In the above equation (7), Cf_p′ Is the ratio after a predetermined time
Let it be an example constant.   And Cf_p= Cf_p′ Holds, focus movement occurs
do not do. For that purpose, equation (7) must be satisfied.
No. The focusing curve 22 at this time is represented by the following equation (8). Therefore,
The left side of equation (7) is C_fp(8)
By substituting and rearranging the equations, equation (9) is obtained. still,
Equation (9) is obtained by replacing equation (8) with equation (2) → equation (3) as described above.
→ By modifying the formula (1), Is obtained. S_{x (T)}Is the focal length information Z_pIs on the tele side
Focus position information S when there is_x, S_{0 (T)}Is the above S_{x (T)}But
Focus position information S when it is on the closest focusing curve 22_x
[That is, S_{x (T)}And F_pxOf intersection]. 23 is as described above
Focus curve at any subject distance
is there. The focal length information Z_p8-bit precision for A / D conversion
255 steps at the tele position and 0 steps at the wide position.
Focus position information S_xIs also 8 bit
0 step at the ∞ position and 255 steps at the closest position
The steps correspond to each other.   FIG. 4 omits a part of the operation sequence of the embodiment shown in FIG.
It is a flowchart of shift control which is abbreviated.   FIG. 5 shows common parts with the embodiment of the prior application shown in FIG.
FIGS. 2 and 3 are diagrams for explaining the operation of FIG.
Portions are given the same reference numerals. In FIG. 5, 27
Is the focal length information Z on the arbitrary focusing curve 23_p1Corresponding to
Points, 28, 30, 33, 35 are focal length information Z_pChange and its direction
Arrows 29, 31, 34, and 36 indicate focus position information S_xof
The arrow indicating the amount of movement and its direction, 32 is Z_p4Focus on
Point on curve 23, Z_{p (T)}Is the focal length information at the tele position.
Information, Z_p2, Z_p3Is the focal length information at some intermediate focal length.
The value of the report.   Now, the operation of the present embodiment thus configured will be described in the fourth.
The description will focus on the flowchart in the figure.   First, we explain the magnification increase operation from the wide side to the tele side.
Then, the up switch 13 in FIG. 1 is pressed.
Therefore, the drive including the information on the scaling direction from the drive direction determination unit 15
The signal (STR) is output. Magnification control unit 16 increases magnification
Is temporarily stored. In FIG. 4,
Although not shown, the maximum feeding amount calculation unit 9 has already output the ZPM8
(Z_p) To perform A / D conversion, and the proportional constant calculation unit 10
Output (S_x) And perform A / D conversion, as shown in Fig. 5.
For example, Z_p1And S₁Assume that In other words, zoomed to point 27
It is assumed that the lens group 2 is located. Next, the "magnifying lens
In the "drive", the scaling controller 16 changes the scaling motor in the direction of increasing the magnification.
M_ZTo rotate. Then, the zoom lens group 2 moves, and the ZPM8
Output (Z_p) Also changes as shown by arrow 28 in FIG.
You. However, FPM7 is focus motor M_FIs not working
Therefore, the distance between the first group lens 2a and the second group lens 2b is
It changes according to the specified cam operation, but the focusing
The lens group is held at a fixed position,
Does not change.   Next, in the “focal length display”, the focal length information Z_p
Current value of Z_p1Is displayed on a focal length display (not shown).
You. In the next “Registration of current location”, the Z_p1To Z_p0= Z_p1
As the variable power motor M_ZFocal length information Z just before the rotation_p
Register Next "Z_pIn "Read", the arrow 28 in FIG.
Focal length information Z that has started to change in the direction indicated_pLatest
The value Z_p1'And read “8 steps or more?”
Checks whether a specified amount of movement has been executed in a branch
If not, the process branches to NO. Soshi
In the next conditional branch, “zoom end?” (In this case, the tele side
Because it has not reached the tele side yet.
Branches to NO, and the magnification switch 13
Or check if 14 is pressed or not (now
If the up switch 13 is still pressed), YE
Branch to S and return to “Register current location” again._p1′
Again Z_p0= Z_p1'And the above operation is repeated.   And Z in Figure 5_p2And reached the above 8 steps
If you do, move from “8 or more steps?” To YES
`` S<sub>x</sub>The current focus position information S<sub>x</sub>,
That is, in this case, the focus drive unit 5 is not operating.
So S<sub>x</sub>= S<sub>(i)</sub>= S<sub>1</sub>Read.   In the following “correction calculation” which is a main part of the prior application invention,
Focusing correction is performed by using equations (4), (5) and (10).
The calculation unit 11 calculates the correction amount Df<sub>p</sub>Is calculated, and the focus control unit 12 calculates
Focus lens drive
Data M<sub>F</sub>To rotate. Therefore, the output of FPM7 (S<sub>x</sub>) Is the fifth
It changes in the direction indicated by arrow 29 in the figure.   However, in FIG.
During the rotation of the focus motor Mf, the variable power motor M<sub>Z</sub>Stopped
Although it is drawn as if
As can be seen from the chart, focus motor M<sub>F</sub>By
Variable magnification motor M during<sub>Z</sub>Is continuing to rotate. Sa
Further, the focus control unit 12 outputs the value of the focus counter 6.
Force Df<sub>c</sub>And the correction amount Df<sub>p</sub>And Df<sub>c</sub>= Df<sub>p</sub>Becomes
Where the arrow 29 is in focus in FIG.
When the curve 23 is reached, the focusing motor M<sub>F</sub>Stop
Then, one cycle of the magnification increasing operation is completed. Further
The variable power switch 13 is not pressed
If so, Z in Fig. 5 again<sub>p2</sub>, S<sub>Two</sub>Is the current position
And return to “Registration”, and in the second cycle,
The operation of the arrows 30, 31 is executed. And up switch
When switch 13 is turned off, it changes from NO to
When the variable magnification motor is stopped, the variable magnification control unit 16
M<sub>Z</sub>Is stopped, and the operation of the variable power drive unit 16 is stopped. And
In the next “Focal Length Display Update”, the new
The display of the focal length f is the focal length information Z.<sub>p</sub>(In this case
Z<sub>p3</sub>) Is updated.   The above magnification is also used for the magnification down operation that moves from the tele side to the wide side.
Since it can be considered almost the same as up operation, it is easy
explain.   When the down switch 14 is pressed, for example,
In FIG. 5, it is assumed that the zoom lens group 2 is located at a point 32.
Then, it is activated from this point 32, and is driven in the direction of arrow 33
When the unit 4 is driven and then reaches the predetermined eight steps, the arrow
The focus driver 5 is driven in the direction indicated by the mark 34.
These are considered as one cycle, and are shown in the following arrows 35 and 36.
The cycle is executed and the down switch 14 is turned off.
At this point, the magnification reduction operation ends.   As described above, the embodiment according to the invention of the prior application is a conventional zoom.
Remove the conditions for the above-mentioned equivalent movement of the
The focus position is changed so that the change of the focus position with the distance is expressed by the equation (1).
In other words, focusing curves 17 to 22 shown in FIG.
Focusing on the wide side
The advantage that the amount of movement of the lens groups 2a and 2b does not increase unnecessarily
There is. Therefore, there is an advantage that the lens outer diameter can be reduced as much as possible.
is there. In addition, apparently (in use), the conventional zoom lens
After focusing once like zoom lens,
There is an advantage that focus movement (blur) does not occur.   However, as mentioned earlier,
Focus drive is variable magnification motor M<sub>Z</sub>Is done while rotating
Therefore, the arrow 29, 31 or the arrow 34,
36 is not horizontal, and arrows 29 and 31
The arrows 34 and 36 point downward and to the left in the figure.
It will have a slope. Therefore, the focus drive of arrow 29
Z just before<sub>p</sub>And S<sub>x</sub>Are Z<sub>p2</sub>, S<sub>1</sub>so
The moving amount (correction amount) of the focus drive indicated by the arrow 29 is
<sub>p2</sub>, S<sub>1</sub>Is calculated by<sub>p</sub>Is increasing
Therefore, after the focusing drive of arrow 29 is completed,<sub>z</sub>Is stopped
Z<sub>p</sub>Is Z<sub>p3</sub>> Z<sub>p</sub>> Z<sub>p2</sub>And the arrowhead of arrow 29 is Z<sub>p2</sub>, S<sub>Two</sub>
, Which means that the focus curve 23 has not been reached,
There was a problem that occurred. Also, the float shown in FIG.
As can be seen from the chart,
Is the variable power motor M<sub>Z</sub>And focusing motor M<sub>F</sub>Is absolutely
Since it is not driven, turn off the zoom switch 13 or 14.
Focus drive may not be performed depending on the timing
You. For example, arrow 28 points to Z<sub>p2</sub>> Z<sub>p</sub>> Z<sub>p1</sub>Advanced
When the up switch 13 is turned off, the arrow 29 ahead
Focus operation is not performed, and blurring may occur.
Was.   Therefore, one embodiment of the present invention capable of solving all of the above problems
Examples will be specifically described below with reference to the accompanying drawings.   FIG. 1 shows an overall configuration of a lens control device according to the present invention.
6 to 8 are block diagrams showing the operation of the embodiment.
For illustration purposes, Fig. 6 shows the focusing drive
The up switch 13 is turned off and the drive direction
Line explaining the correction operation when the stop instruction signal is output
FIG. 7 shows that the up switch 13 is turned off during the variable power driving.
When the drive direction determination unit 15 outputs a stop instruction signal,
FIG. 8 is a diagram for explaining the correction operation in the case of FIG.
6 is a flowchart illustrating an operation order of the embodiment.   In FIG. 6, 17 and 22 have already been described, respectively.
The focus curve at the ∞ position and the focus curve at the closest position. 37
Is a small interval ΔS from the focusing curve 17 to the closest side<sub>x</sub>Is set by the width of
The danger zone on the top position side, 38 shows the focusing curve 22 on the long focal length side
(Upward in the figure) minute interval ΔZ<sub>p</sub>The curve that has been translated
The closest danger zone formed by the focal curve 22 and 39
Is Z<sub>p</sub>= Z<sub>p (s)</sub>Shows the position just before the zoom drive starts
Starting point 40 is any focusing curve including this starting point 39, 41 and
And 42 are the above focusing curves, 40 and Z respectively.<sub>p</sub>= Z<sub>p (1)</sub>Intersection with
And Z<sub>p</sub>= Z<sub>p (3)</sub>Intersections with 43 and 44 are both Z<sub>p</sub>= Z<sub>p (E)</sub>
Above and each S<sub>x</sub>= S<sub>(2)</sub>The temporary end point which is the intersection with
And the end point which is the intersection with the focusing curve 40. 45 and 46
Is an arrow indicating the drive direction of only the variable-power drive, and its size is
8 steps, especially arrow 46 is S<sub>x</sub>= S<sub>(1)</sub>It's above. 47 and
And 48 are the driving directions for focusing operation while performing variable magnification driving
, 49 is an arrow indicating the driving direction of only the focusing drive,
ΔE1 and Serr are focusing errors, respectively.   In addition, Z of arrow 48<sub>p</sub>The size of the direction is 1 step <Z<sub>p (E)</sub>−Z<sub>p (3)</sub><8 steps In a relationship. In the following FIG. 7, FIG.
The same parts are denoted by the same reference numerals, and duplicate descriptions are omitted.
You.   In FIG. 7, reference numeral 50 denotes a driving direction of only the variable power driving.
With arrow, the size is more than 1 step and 8 steps
Shall be smaller than 51 is Z<sub>p (n)</sub>S above<sub>x</sub>= S<sub>(2)</sub>
The temporary end point that is the intersection with, 52 is Z<sub>p (n)</sub>With the focusing curve 40 above
The end point 53, which is the intersection of, indicates the drive direction of only the focus drive
It is an arrow.   FIG. 8 is also described in the following description of the operation.
The description is omitted here.   Regarding the operation of the present embodiment configured as above, mainly
The description proceeds with reference to FIG.   First, the zoom switch 13 or 14 is turned off during the focusing drive.
Will be described. Now, the up switch 13 in FIG.
It is assumed that the key has been pressed (hereinafter,
). As a result, the drive direction determination unit 15
Driving instruction including information on the zooming direction of the dynamic signal (STR)
The signal is output, and the flowchart in FIG.
Begin. First of all, in the "magnification reading",
The control unit 16 temporarily indicates that the magnification
Remember. Next, with “N counter = 0”, the danger zones 37 and 38
Count the number of danger zone check loops to escape
Clears the loop counter to zero. Next, "Z<sub>p</sub>Read
And "S<sub>x</sub>In “Read”, the maximum feeding amount calculation unit 9
Output (Z<sub>p</sub>), Performs A / D conversion, and the
PM7 output (S<sub>x</sub>) To receive A / D conversion
Remember. That is, in this case, Z at the starting point 39 in FIG.<sub>p</sub>You
And S<sub>x</sub>Is the value of In the next conditional branch “Multiply up?”
In the direction of magnification increase by the information temporarily stored earlier
Since it is known that there is, branch to YES. The next "Schiff
The "control" has already been described in detail in FIG.
Correspondence with the operation of the chart is omitted, and referring to FIG.
Only the result of the operation will be described.   Assuming that the variable power lens group 2 is at the position of the starting point 39,
Only the scaling drive is performed in the direction of arrow 45. Variable power drive
Continued below. Arrow 45 advances 8 steps Z<sub>p</sub>= Z<sub>p (1)</sub>
After reaching, focusing operation is added, as indicated by arrow 47.
To the upper right. Therefore, Z at the starting point 39
<sub>p (s)</sub>, S<sub>x</sub>And Z after zooming drive<sub>p (1)</sub>Calculated based on
Correction amount Df for focusing<sub>p</sub>Focus position by intersection 41
However, the displacement caused by the variable-power driving causes the correction amount D
<sub>fp</sub>And output D of focus counter 6<sub>fc</sub>Match and focus drive
Movement stop position 41 'is Z<sub>p</sub>= Z<sub>p (2)</sub>, S<sub>x</sub>= S<sub>(1)</sub>And
New focal length Z by zooming<sub>p (2)</sub>With a focal point of 41 ″
Causes a focusing error of ΔE1. Up switch 13 continues
Since it is pressed, it is further driven to zoom in the direction of arrow 46 and Z<sub>p</sub>
= Z<sub>p (3)</sub>The focus drive is started again from when
Driven in the direction of arrow 48, the temporary end point 43 is reached.
As can be seen from the flowchart of FIG.
During operation, that is, "focusing lens drive" in FIG.
During execution, the zoom switches 13 and 14 are not checked.
So, Z<sub>p</sub>= Z<sub>p (3)</sub>After crossing the middle of arrow 48 (Z<sub>p (3)</sub>And Z
<sub>p (E)</sub>Even if the up switch 13 is turned off during
Not. Therefore, as shown above,
Even if the switch 13 is turned off, Df<sub>p</sub>=
Df<sub>c</sub>Focus driving and zoom driving stop at the temporary end point 43
Stop and execute the `` shift control '' with the focusing error Serr occurring.
When the processing is completed, the flow returns to FIG. this
The operation is executed by the control prohibition unit 11b of FIG.
Camera body (not shown) input via terminal 11a
AF data from the AF unit and its control signals
Output to the application control unit 12, and the acceptance prohibition is released.
This state is maintained until it becomes. Next, "Z_pRead "
End point 43 Z_pThe value Z_{p (E)}And read the next "
Move up? In Z_{p (3)}Compare with Arrow 48 Z_pdirection
Is larger than one step, so branch to YES_xReading
S)₍₂₎Read. And equations (4), (5),
Correction amount Df calculated by equation (10)_pAccording to "Four
Focusing drive in the direction shown by arrow 49
Do. Finally, release the above-mentioned reception prohibition with “Reception prohibition release”.
END and zooming section Z in Fig. 6_{p (s)}To Z_{p (E)}Zoom operation to
(Zoom-up operation) is all ended.   Next, as shown in FIG.
The operation when the switch 13 or 14 is turned off will be described. 8th
In the flowchart shown in the figure, "Increase magnification?"
The process is the same as described above up to branching to S. Further in FIG.
In the “Shift control” shown, start from “Current position registration”.
In other words, "Move more than 8 steps?" Branch to NO
? "To NO and" Scaling switch ON? "To YES
Repeat the check loop operation to return to
Is returning. That is, in FIG.
The operations up to 45, 47, 46 and 48 are the same as those in FIG.
Drive through the temporary end point 43 and drive in the direction of the arrow 50
The status of the check loop corresponds to the operation of the check loop.
You. Therefore, in this case, when the up switch 13 is turned off,
At the temporary end point 51, the variable power drive is immediately stopped and the
"" Ends. Returning to Fig. 8 with RTS, subsequent operations
Is almost the same as the description in FIG. 6, and is indicated by an arrow 53 in FIG.
Focus drive is performed, and the end point 52 is removed to remove the focus error Serr.
To reach the variable magnification section Z_{p (s)}To Z_{p (n)}To increase the magnification
finish.   In addition, NO in the conditional branch of “multiply-up?” In FIG.
The case of branching is explained, but it is directly related to the gist of the present invention.
Since there is no such information, it is described briefly. Turn down switch 14 ON
Apply a drive instruction signal in the magnification down direction to the magnification control unit 16.
Then, in "in the danger zone?", In the danger zone 37 or 38
Check if there is a start point 39, if not, branch to NO
Except for the zooming direction, the operation is the same as above, and in some cases
Branches to YES and focuses on "move to safe area"
If the lens groups 2a and 2b are within the danger zone 37, move to the nearest side, danger zone 38
If it is within, drive a predetermined amount to the position 、 and perform this operation within 3 times
The starting point 39 is escaped from the danger zone 37 or 38 repeatedly. 3
If the number of times is greater than or equal to
And stop at STOP.   Note that the magnification reduction operation is described above and
The explanation is omitted because it can be inferred from the scaling down operation of FIG.
You.   Thus, in the present embodiment, the variable power switch 13 or
Is turned off by arrows 49 or 53 no matter when 14 is turned off.
Focusing lens group 2a, 2b
Because it reaches the end point 44 or 52 on 0, after the scaling operation
There is an advantage that defocus does not occur.   Also, while the magnification switch 13 or 14 is pressed,
Motor M_ZIs required for zooming operation because
There is an advantage that time is reduced as much as possible.   Also, during the final correction, i.e. during the operation of arrow 49 or 53
Is a control signal from the outside (for example, the AF section of the camera body).
Because it is prohibited, the focus position may shift and blur
There are no benefits.   Also, the focusing curve 17 at the ∞ position and the focusing curve at the closest position
Danger zones 37 and 38 are provided near 22 and once
Escapes from the starting point 39, so the subsequent operations are almost the same
There is an advantage that the above operation can be applied to all regions.   It should be noted that the present invention is not limited to the above-described embodiment,
Implementation of various modifications without departing from the gist
Is possible.   For example, “Move one step or more?” In FIG.
2 steps and 4 steps etc.
Within 1 to 8 steps if within the depth of focus
Should be fine. Adjustment and control are critical.
If not, 0 steps may be used.   In addition, the present invention relates to a varifocal recording
An example of application to a lens
Variable power optical system consisting of double lens group and focusing lens
Is also applicable. (E) Effect   As described above in detail, according to the first aspect, the variable power lens
While the group is being driven for zooming, the focus correction control means
Predetermined calculation based on the positions of the lens group and the zoom lens group
Focus lens corresponding to the position of the zoom lens group.
The correction amount of the lens group is calculated, and the focusing drive
The stage is controlled so that it is necessary for the desired zooming operation.
Time is as short as possible.
Can automatically correct the focus,   In addition, as described above, during focusing operation,
When driving, the correction amount for a certain position of the zoom lens group
Is calculated, and during the execution of the focus correction based on the correction amount,
Since the zoom lens group is moving,
The focusing lens group will not reach the corresponding position
However, in the first aspect, the variable power lens is driven by the drive instruction signal.
Variable magnification driving means that was driving the group received a stop instruction signal
After stopping the zoom lens group at the time, the zoom lens
The position of the focusing lens group corresponding to the group position
The focus correction controller controls the focus level through the focus drive
To move the group of lenses, as soon as possible
Slight focusing while achieving zooming to the desired zooming position
Correction deviation may occur at any time when the magnification drive is stopped.
In any case, after stopping the zoom lens group,
Can move the focusing lens group reliably,
Zooming and focusing operations can be completed,   In particular, correction of the image shift after stopping the zoom lens group
During execution, for example, the automatic focusing device or the shutter release switch
Focus drive is controlled by drive signals output from switches
Can be reliably prevented by the control ban,
Provide a lens control device that can perform reliable zooming and focusing
be able to.   Further, according to the second invention, substantially the same as the first invention is provided.
In addition to obtaining the effect, in particular,
Variable power lens group that monitors whether the output change has changed by a predetermined amount
Equipped with a movement amount monitoring means, and a variable magnification lens
The zoom lens group is moving and the variable magnification lens group
The focus correction control means is activated each time it is determined that a predetermined amount has changed.
To move the focusing lens group
While keeping the viewfinder observation image in good condition,
The time required to reach the intended focal length
It is possible to provide a lens control device that can be reduced as much as possible.
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the overall configuration of an embodiment of a varifocal lens control device according to the present invention, and FIG. 2 is a graph showing characteristics of the device according to the prior application. FIG. 3 is a diagram showing, for each subject distance, the relationship between the total system focal length f to be set and the extension amount _Sx of the focusing lens group corresponding to the subject distance D. FIG. FIG. 4 is a diagram illustrating a principle of the operation of a certain focus correction calculation unit with a part of FIG. 2 omitted, and FIG. 4 is a shift diagram with a part of the operation sequence of FIG. 5 described below omitted. FIG. 5 is a flow chart of the control, FIG. 5 is a diagram for explaining the operation of the prior application, and FIGS. 6 and 7 are diagrams for explaining the operation of the embodiment shown in FIG. FIG. 6 shows the case where the zoom switch is turned off during the focusing drive while performing the zoom drive. FIG. 7 is a diagram showing the operation, FIG. 7 is a diagram showing the operation when the variable power switch is turned off during the variable power drive, and FIG. 8 is a diagram showing the operation sequence of FIGS. It is a flowchart. 1 ... optical axis, 2 ... magnification lens group, 2a ~ 2e ... first group ~
Fifth group lens, 3 ... film surface, 4 ... variable magnification drive unit,
5 Focus drive unit 6 Focus counter
7 ... group lens group position detector (FPM), 8 ... variable magnification lens group position detector (ZPM), 9 ... maximum feeding amount calculation unit, 1
0… Proportional constant calculator, 11… Focus correction calculator, 11b…
Control prohibition unit, 12 Focus control unit, 13 Magnification up switch (up switch), 14 Magnification down switch (down switch), 15 Drive direction determination unit, 16
... variable power control unit, _MZ ... variable power motor, M _F ... focus motor, + V ... power supply.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02B 7/08 G02B 7/10

Claims (1)

(57) [Claims] A lens control device for driving and controlling a variable power optical system including a variable power lens group and a focusing lens group disposed on the same optical axis; and a focusing drive unit for driving the focusing lens group; Variable power driving means for driving the lens group; focusing lens group position detecting means for detecting the position of the focusing lens group on the optical axis; and detecting the position of the variable lens group on the optical axis. Variable magnification lens group position detecting means; externally operable variable magnification driving instruction means for providing a driving instruction signal or a stop instruction signal for instructing the variable magnification lens means to drive or stop the variable magnification lens group; The focusing lens corresponding to the position of the zoom lens group by a predetermined calculation based on the positions of the focusing lens group and the zoom lens group while the zoom lens group is driven by the zoom driving unit. Calculate group correction amount The focus correction control means for controlling the focus drive means to drive the focus lens group according to the correction amount, and the focus correction control means controls the focus drive means. A control prohibition means for prohibiting another control means provided separately from controlling the focus driving means, wherein the variable power driving means which drives the variable power lens group by the drive instruction signal is provided. After stopping the variable power lens group at the time of receiving the stop instruction signal, the focus correction control means moves to a position corresponding to the correction amount of the focusing lens group corresponding to the variable lens group position. A lens controller, wherein the focusing lens group is moved via the focusing driving means. 2. A lens control device for driving and controlling a variable power optical system including a variable power lens group and a focusing lens group disposed on the same optical axis; and a focusing drive unit for driving the focusing lens group; Variable power driving means for driving the lens group; focusing lens group position detecting means for detecting the position of the focusing lens group on the optical axis; and detecting the position of the variable lens group on the optical axis. Variable power lens group position detecting means, externally operable variable power drive instruction means for providing a drive instruction signal or a stop instruction signal for instructing the variable power drive means to drive or stop the variable power lens group, The focusing lens corresponding to the position of the zoom lens group by a predetermined calculation based on the positions of the focusing lens group and the zoom lens group while the zoom lens group is driven by the zoom driving unit. Calculate group correction amount Focus correction control means for controlling the focus drive means to drive the focus lens group according to the correction amount, and a separate focus correction control means while the focus correction control means controls the focus drive means. Dominance inhibiting means for inhibiting other control means provided from dominating the focusing drive means, and zooming lens group movement for monitoring whether or not the output of the zooming lens group position detecting means has changed by a predetermined amount. Amount monitoring means, and the focusing correction control means is controlled by the variable power driving means each time the variable power lens group is moving and the variable power lens group movement amount monitoring means determines that the predetermined amount has changed. A lens controller that operates to move the focusing lens group.