JP2964384B2 - Variable power lens device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable power lens device.
More specifically, a variable power lens arranged on the same optical axis
Variable magnification optical system consisting of lens group and focusing lens group for variable magnification operation
Also relates to a variable power lens device that causes an image position shift
It is. [0002] 2. Description of the Related Art A zoom lens operates for zooming.
Even if the imaging position shifts (so-called focus movement or focus
Focus) for each zooming operation.
Easy operation without troublesomeness, but compared to single focus lens
Because the full aperture F-number is dark, for example,
Focus adjustment (focusing operation) using the
Some skill is required. In recent years, AF of cameras
Going forward and solving this problem
Operators (users) will be able to demonstrate their future mobility
Focus only on the composition decision according to the drawing intention.
And improved operability. General
Focusing (focusing operation) of the zoom lens
Move the focusing lens group provided in a part of the optical system.
It is done by movement. [0003] The zoom lens is used in the entire zoom range.
Focusing lens for the same subject distance
The amount of movement of the group is almost the same (hereinafter, this is referred to as “equivalent
Movement)), and therefore the
Moving member for focusing lens group (distance ring)
On the other hand, while the fixing ring
It is only necessary to attach an index, and depending on the zooming, the subject
There is an advantage that it is not necessary to change the distance scale. I
However, it also depends on the lens configuration of the zoom optical system.
However, the inner focusing method and rear focusing
In the focusing type zoom lens, the above-mentioned
When designing optical under the condition of realization, the lens
There is a problem that the configuration becomes complicated.
The moving amount (extending amount) of the focusing lens group
There was a problem that it became bigger. Again, this
As a result, the outer diameter of the lens increases,
There is also a problem that the weight increases. [0004] As described above, the zoom lens is
Operability is improved by combination with AF function.
Even escape from the above-mentioned equal movement condition of the zoom lens
Because it cannot be made compact,
The problem that implementation was difficult remained.
Accordingly, the present applicant has proposed a varif that can solve the above-described problems.
Invention relating to the focal lens control device (hereinafter referred to as “the prior invention”)
), The Japanese Patent Application No. 62-013345
Suggested. [0005] That is, the above-mentioned invention of the prior application uses the same optical axis.
The variable magnification lens group and focusing lens group
Move the focusing lens group of the double optical system from close range to infinity
From the closest position on the optical axis corresponding to the subject distance
After setting the in-focus position up to the telephoto position,
Lens group to minimize the focal length of the entire zoom optical system
From any first focal length between the distance and the longest focal length
By updating to the second focal length,
Varifocal lens that causes image shift
A focal length detecting means for detecting the focal length of the entire system,
A focusing lens for detecting the position of the focusing lens group on the optical axis.
Lens group position detecting means and the output of the focal length detecting means.
The infinity of the focusing lens group at the focal length
The maximum for calculating the feeding amount from the distant position to the close position.
Feed amount calculating means, this maximum feeding amount calculating means and the focusing
The output of the lens group position detecting means
Proportional constant calculating means for calculating the output ratio, and the proportional constant
Calculating means, the maximum feed amount calculating means, and
Receives the output of the focus lens group position detecting means
Imaging from the in-focus position caused by updating the focal length
Focus correction calculation means for calculating the amount of displacement as a correction value
Focusing drive means for driving the focusing lens group;
Movement amount that generates a signal corresponding to the movement amount of the focusing lens group
Monitoring means, the movement amount monitoring means, and the focusing correction operation.
Receiving the output of the
Focusing control means for controlling to drive to a focusing position;
A variable-power driving unit for driving the variable-power lens group and a separately provided
Receiving the start signal from the starting means,
Variable power control means for controlling the power of the variable power optical system.
Automatically corrects the imaging position shift due to updating the focal length of the entire system
It is configured to be. [0006] According to the invention of the prior application configured as described above,
The lens optical system itself has a very simple configuration, and is compact, lightweight and
In addition to being inexpensive, the entire lens control device is similarly small and light.
A variable-magnification lens group,
To the second focal length from the focal length of
Varifocal lens-specific imaging position even when the distance is updated
The displacement can be corrected instantaneously and the in-focus state can be maintained.
Therefore, it is practically equivalent to a zoom lens.
You can get things. [0007] However, the details will be described later.
As explained, the varifocal lens is the shortest focus
The change in the focal length of the entire system from the distance to the longest focal length
The focus position at infinity (遠 position)
The focus position at the closest position is far from the infinity position.
It is configured to change as
Are the multiple focussing units arranged in a part of the zoom optical system.
By moving each group of Glenns
I have. Each focusing lens group is
A cam frame (hereinafter referred to as “focus
The cam groove formed in the "cassell")
The zoom lens group drive frame (hereinafter referred to as
Double cell).
A fixed lens interval is set. Follow
The cam frame for driving the zoom lens group (hereinafter referred to as “magnification cell”)
To each other through different cam grooves.
Inevitably zooming because focusing lens group is combined
Machine that drives both lens group and focusing lens group
The structure is complicated, simplifying the configuration, reducing costs, and
This was an obstacle to achieving impact. The present invention has been made in view of the above circumstances.
Therefore, the purpose is to make it cheap and small
Also use a simple optical system, zooming,
Magnification that can automatically and quickly correct image misalignment
A lens device is provided. [0010] SUMMARY OF THE INVENTION The present invention is directed to the above-mentioned object.
In order to achieve this, mainly a magnification unit arranged on the same optical axis
Variable power lens system having focusing function and focusing lens having focusing function
Variable magnification optical system consisting of
The relationship with the extension amount of the focusing lens system in the optical axis direction is within the zoom range.
At any magnification position, and any first within the magnification range
Zooming operation for updating the focal length to an arbitrary second focal length
In a variable-power lens system that causes an imaging position shift due to
Means for detecting the position of the zoom lens system
And second detecting means for detecting the position of the focusing lens system
Prior to the scaling operation,
Based on the output of the first and second detection means,
Defines the position of the focusing lens system corresponding to the position of the lens system
Initial condition calculating means for calculating an initial condition to be changed;
In the double operation, the initial condition calculating means and the first and second conditions
Based on the output of the detecting means,
The position of the focusing lens system is controlled to correct the imaging position shift.
Variable magnification focusing correction control meansAnd the above initial condition calculation
Means include a focusing lens system related to the position of the zoom lens system
The maximum feed amount, focus position information and both
Include arithmetic means for determining the initial condition of the related proportional constant.
AndFeatures. [0011]The present invention also achieves the above object.
Mainly has a zoom function, which is arranged on the same optical axis.
Variable magnification lens system and focusing lens system with focusing function?
Variable magnification optical system, the subject distance and the focusing lens
The relationship with the extension amount in the optical axis direction of the zoom
Any first focal length within the zoom range
By updating the focal length from to any second focal length
In a vari-focal lens apparatus that causes an imaging position shift,
First detecting means for detecting the position of the double lens system;
Second detecting means for detecting the position of the focal lens system;
Prior to the doubling operation, the first and
The position of the zoom lens system is determined based on the output of the second detection means.
Initial condition that defines the position of the focusing lens system corresponding to the position
Initial condition calculating means for calculating the number of
The initial condition calculating means and the first and second detecting means
Of the imaging position associated with the scaling operation based on the output of
Zooming to control the position of the focusing lens system to compensate for this
Having focus correction control means, the aboveThe second detecting means is as described above.
Focusing lens systemthe aboveDetecting the position from the zoom lens system
The third detection means and the relative position from the zoom operation start position
And a fourth detecting means for detecting,the aboveInitial condition operation
For the means, using the output of the third detection means,the aboveVariable magnification
The output of the fourth detection means is used for the focus correction control means.
It is characterized by having. [0012]More specifically,For variable magnification focusing correction control means
Control of the focusing lens system by
At the time interval of
Is performed every time the output of the detecting means changes by a predetermined amount.
It is assumed that. Furthermore, the initial condition calculating means includes:
Maximum extension of the focusing lens system in relation to the position of the zoom lens system
Amount, focus position information and ratios related to both
Characterized by including a calculating means for obtaining an initial condition of the constant.
Is what you do. [0013] [Action]FirstThe term condition calculation means is activated to perform the scaling operation.
When operating the means, the output of the first and second detection means
Position information of a variable power lens system and initial focus lens system
Conditions, e.g., maximum feed at the start of zooming, proportional
Compute numbers and so on. Zooming operation starts from this state
And the variable power in-focus correction control means outputs the initial condition calculation.
And the first and second detection means at the time of the magnification change.
The focusing position of the focusing lens group is
The calculation is performed later to drive and control the focusing lens system. [0014] 【Example】Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
This will be specifically described.FIG. 1 shows the overall configuration of the present invention.
It is a block diagram. In FIG. 1, reference numeral 1 denotes light of a variable power optical system.
The axis 2 is arranged on the optical axis 1 so as to be movable along the optical axis 1.
As a variable power lens system that constitutes the variable power optical system
2a, 2b, 2c, 2d, 2
e is a first lens composed of a single lens or a plurality of lenses.
Group lens, second group lens, third group lens, fourth group lens
And the fifth lens group. And the first group lens 2a
And the second lens unit 2b as a focusing lens system.
All focusing lens groups. This first group,
A second group lens 2c including a second group lens 2a, 2b
To form the zoom lens group 2 with the fifth lens group 2e.
ing. The variable power lens excluding the second lens unit 2b
The zooming group 2 constitutes a zooming group. In addition,
The total focal length of the variable power optical system consisting of lens group 2 is f
is there. 3 is the film surface, and 4 is the longest focal length f of the entire system.
The focal length on the telephoto side as a point distance (hereinafter simply referred to as "tele side")
Abbreviation) to the wide-angle focal length as the shortest focal length
(Hereinafter simply abbreviated as “wide side”)
To set the focal length, drive the zoom unit.
Variable magnification motor Mz as double driving means and machine described later
Variable magnification drive unit consisting of components, 5 from infinityMinimum shooting distance
IeNothing on the optical axis 1 corresponding to the subject distance approaching
Focusing position between the telephoto position (∞ position) and the closest position
Driving the first group lens 2a and the second group lens 2b
(Specifically, the first group lens 2a and the second group lens 2b
  Move in the direction of the optical axis while keeping the distance between
Focus motor M as focusing drive means_F   And
And a focus drive unit including a mechanism unit described later. 6
And 7 are the first group lens 2a and the second
Driven by the focus drive unit 5 together with the group lens 2b
Of these, the slit disk 6a is rotationally driven.
The rotation from the photo interrupter 6b
The first group lens 2a generates a pulse proportional to the number, and
Second detection of the amount of movement of the second group lens 2b on the optical axis 1
As a fourth detecting means which is one of the detecting means
A focus counter 7 is provided for the first group lenses 2a and 2a.
And the position of the second lens unit 2b on the optical axis is detected.
Voltage in proportion to the position as focus position information Sx
Third detection, which is one of the output second detection means
Focusing lens group position detector (hereinafter referred to as “FPM”)
Abbreviated). Numeral 8 drives the variable power drive unit 4 together with the variable power components.
Detects the position of the zoom lens system and calculates the focal length of the entire system.
output a voltage proportional to f as focal length information Zp
Zoom lens group position detector (hereinafter referred to as first detection means)
Below, abbreviated as “ZPM”), 9 is the focal length information Zp.
  , And A / D-converted.
1st group lens 2a from the position to the closest position
The amount of movement of the group lens 2b (ie,Maximum feed amount, below,
Simply referred to as "amount delivered") Maximum feed amount for calculating Fpx
The calculation unit 10 has an output Fpx of the maximum feeding amount calculation unit 9 and
The output Sx as the focus position information of the FPM 7 is
After receiving the output Sx and performing A / D conversion,
A proportional constant calculating unit that calculates and outputs a proportional constant Cfp;
11 receives the above three outputs Fpx, Cfp, Sx
Focus correction calculation for calculating a correction amount Dfp for focusing
Department. Reference numeral 12 denotes an output Dfc of the focus counter 6.
And an output corresponding to the correction amount of the focus correction calculation unit 11
Focuser for controlling focus drive unit 5 in response to Dfp
Control unit. 13 to 15 constitute start-up means;
Both and 14 can be operated externally to start the scaling operation
A variable magnification switch consisting of a push button switch, 13 is a double
Rate up switch (hereinafter simply referred to as “up switch”)
, 14 are magnification down switches (hereinafter simply referred to as “downs”).
15) are switches 13 and 14
The rotation direction of the variable power motor Mz was determined in response to the output of
A driving direction determination unit that outputs a start signal (STR),
6 is a variable power drive receiving the start signal STR and the output Fpx.
It is a scaling control unit that controls the moving unit 4. Here, the maximum feeding amount calculation unit 9 and the proportional constant operation
Calculation unit 10, focus correction calculation unit 11, focus control unit 12
And a variable power focusing control unit with the variable power control unit 16.
Make up. Prior to the magnification operation, the first detection
Output means (ZPM8) and second detection means (focus
After receiving the output of the counter 6 and FPM 7), place it at infinity
From the distance to the nearest position (referred to as the maximum
The maximum feed amount calculation unit 9 for calculating the report Sx, the proportionality constant Cf
proportional constant calculation unit 10 for calculating p, and these calculations
A machine including storage means (not shown) for temporarily storing results
The active part is herein referred to as initial condition calculating means.
I do. Note that + V indicates a power supply and input / output of each unit.
The relationship shows only the main signals. By the way, each of the arithmetic units described above is
The contents of the operation to be executed and the operation expression related to this are shown below.
Show. A conventional zoom lens has a variable power operation (all focal lengths).
Defined as not moving in focus due to update of point distance f)
However, as a basic idea of the present invention,
The focus movement is allowed (eventually, this focus
Correct the movement to bring it into focus). Focusing
Assuming front focusing method
I do. The maximum feeding amount calculation unit 9 is located at the infinity position to the closest position.
Output corresponding to the feed amount up to Fpx, ZPM8 output
Is Zp, and the lens-specific constant of the variable power optical system is C
₁   , C_Two  , C_Three  And when An operation is performed using the following arithmetic expression. Further, the maximum feeding amount calculating section 9 will be described later.
In the cam diagram at the position ∞ of the first group lens 2a in FIG.
The corresponding focus position information Sx is Sx (∞).
When, It is calculated by the following formula. Here, Zp is the above Z
Output of PM8, A₀ , A₁ , A_Two Is a variable power optical system as above
Is a constant unique to the lens. The proportionality constant calculator 10 is provided with a
The output of FPM7 immediately before the start of operation is represented by S (i),
The output of the constant operation unit 10 is Cfp, and the
Maximum feeding amount calculation unit 9 based on the output of ZPM 8 immediately before the start of operation
Let Fp (i) be the output of An operation is performed using the following arithmetic expression. The focusing correction calculation unit 11 includes a variable power driving unit 4
At a predetermined time interval after the operation of
The above focus correction calculation when the output change reaches a predetermined amount
The output of the unit 11 is S (e), the output of the proportionality constant calculator 10
Is Cfp, the output Zp of the ZPM 8 at the point of time to be corrected, and
And the value of the above Sx (∞) is Zp₁ , S ₁Toss
When   S (e) = Cfp · Fp (e) + S ₁                             (4) The calculation for obtaining the expected focus position S (e) is performed. Was
Where Fp (e) is Zp = Zp₁ Into equation (1)
Value. The concept of the present invention is based on the following.
In the expression (5), the above expressions (1) to (4) are obtained from the expression (5).
Derived. [0025]   D = (C₀  ・ Zp + C₁ ) ・ Sx + C_Two                          (5 ) Here, D is the subject distance C₀  , C₁ , C_Two  At design time
This is a set constant that is determined. That is, in the equation (5), the subject distance D is
Implements means to control Zp and Sx so that they do not change
If you change the focus by moving the
) Becomes possible. However, focusing lens
The amount of movement of the group is not the same amount of movement. In other words, the theory of the present invention
It can be said that the theory removes the condition of mass transfer. FIG. 2 shows a variable magnification structure of the apparatus of the present invention shown in FIG.
A cam diagram showing the movement of the group, for example, from the wide side
The case where the entire system focal length f is updated to the side is shown. Sx
  Is the focus position described above, which is the output of the third detection means.
Location information Sx.
Glens group (first group lens 2a and second group lens 2
b) indicates the amount of movement (movement) corresponding to the subject distance
ing. Zp is also the output of the first detection means.
In the drawing, the focal length information Zp
The amount of movement caused by the zooming operation of the second group lens is
It is shown as a representative. In this drawing, 1 is a wafer.
The optical axis 1 'on the id side is the light beam on the tele side.
Axis. FIG. 3 shows a variation not specifically shown in FIG.
The structure of the mechanism of the double drive unit 4 and the focus drive unit 5
4 to 8 (except for FIG. 5B).
5) is an enlarged partial plan view showing each part in FIG. 3, and FIG.
FIG. 5B is a partial cross-sectional view taken along line AA ′ of FIG. In FIG. 3, 17 and 18 to 20 are
First group lens 2a and third group lens 2c to fifth group
A first group cell for fixedly supporting the lens 2e, and
It is a third group cell to a fifth group cell. 21 and 22-24
Are the first group cells 17 in directions substantially orthogonal to the optical axis 1 respectively.
And the third group cell 18 to the fifth group cell 20 respectively.
And the third to fifth pins. 25
Is a fixed cell having a cylindrical cross section as an immovable member;
Is the first half of this fixed cell 25 and 27 is the first half 26
The second half of the fixed cell 25 having the smaller diameter, 28 and
And 29 to 31 are a first pin 21 and a third pin, respectively.
Fixed cell having a width in which 22th to fifth pins 24 can be fitted
25 with a fixed cam groove of the fixed cell 25
is there. 32 is the optical axis direction on the outer periphery of the latter half 27 of the fixed cell 25.
Inserted in a rotatable state with movement in the
33a is a rear end of the variable power cell 32.
The gear portion 33b formed on the outer periphery of the flange portion of the portion,
Similarly, a projection is provided at the front end of the variable magnification cell 32 substantially orthogonal to the optical axis 1.
The rotation transmitting pin 34 is the first half 26 of the fixed cell 25.
Rotatably fits in the inner circumference of the lens and can also move in the optical axis direction
The scaled transmission cell 34a is the scaled transmission cell 34
Has a length corresponding to at least the movement amount in the optical axis direction.
And has a width in which the rotation transmitting pin 33b can be fitted.
It is formed along the optical axis 1 from the rear end of the variable power transmission cell 34.
The notch 35 is used to connect the second group lens 2 b to the variable power transmission cell 3.
The first pin 21 is fitted into the fixing portion 36 for fixing to the 4
Cams drilled in the variable power transmission cell 34
It is a groove. Similarly, reference numerals 37 to 39 denote third pins 22 to fifth pins.
Cell 24 has a width that can fit into each
Each of the cam grooves 40 pierced corresponds to the fixed cell 25.
It is fitted around the outer periphery of the front part 26 so as to be movable only in the optical axis direction.
Focus transfer cells 40a and 40b
From the outer and inner circumferences of the focus transmission cell 40
Focus pins projecting in the direction orthogonal to
  41 and 42 are the focus pins 40, respectively.
b has a width in which the first half 26 of the fixed cell 25 can be fitted.
The linear power drilled in the upper and variable power transmission cells 34, respectively.
The groove and the cam groove 43 are provided in the focus transmission cell 40.
Is rotatably fitted to the outer periphery of
Focus cell. Reference numeral 43a denotes a rear end of the focus cell 43.
Gear part formed on the outer periphery of the flange part provided in the part,
43b is a width into which the focus pin 40a can fit.
A cam groove formed in the focus cell 43;
44 is a focus motor M described with reference to FIG._F , 44a
Is the focus motor M_F   Driven by the focus
The driving gear 45 meshes with the gear portion 43a of the
45a is the gear portion 3 of the variable power cell 32.
3a and the driving force driven by the variable power motor Mz
Gear. In FIGS. 4 to 8 described below, FIG.
The same parts are denoted by the same reference numerals, and duplicate descriptions are omitted.
You. FIG. 4 shows a straight line of the rear half part 27 of the fixed cell 25.
The cam grooves 29 to 31 and the cam grooves 37 to 39 of the variable power cell 32
The straight cam grooves 29 to 31 are shown in FIG.
Each of them is formed in a long hole along the optical axis direction,
The cam grooves 37 to 39 are determined when the zoom lens group 2 is designed.
It is formed in a long hole shaped along the cam diagram. In FIG. 5, the upper diagram (a) and the lower diagram
FIG. 4B shows the connection between the variable power cell 32 and the variable power transmission cell 34.
FIG. 5A is an enlarged view of the portion shown in FIG.
FIG. 4B is a cross-sectional view taken along the line AA ′ of FIG.
is there. In FIGS. 5A and 5B,
The notch 34a is a straight slot-shaped notch along the optical axis 1.
And the rotation transmitting pin 33b fits into the notch 34a.
Have been. Therefore, the variable power transmission cell 34 moves in the optical axis direction.
The movement is restricted by the variable magnification cell 32.
Instead, only the rotational movement of the variable magnification cell 32 is transmitted.
Has been established. FIG. 6 shows the first half 26 of the fixed cell 25 and the magnification.
The respective cam shapes and relationships with the transmission cell 34 are shown.
FIG. 11 is an enlarged plan view as viewed from the third focus transmission cell 40 side.
is there. The cam groove 36 of the variable power transmission cell 34 is
Formed in accordance with the cam diagram determined at the time of design of 2.
I have. Therefore, the first group cell 17 is independent of the focusing operation.
Moves on the optical axis with the rotational movement of the variable power transmission cell 34
It is configured to perform a variable magnification operation. FIG. 7 shows the cam groove 43 of the focus cell 43.
b is an enlarged plan view showing the shape of b and the directional relationship with the optical axis 1.
It is. As can be seen from FIG.
It is formed in an inclined shape. Therefore, focus
The rotational movement of the cell 43 depends on the optical axis of the focus pin 40a.
Directional linear motion, ie, light from the focus transfer cell 40
It is configured to be converted into a linear motion in the axial direction. FIG. 8 shows the focus cell 40 and the fixed cell 2.
5 in relation to the first half 26 and the variable power transmission cell 34;
Focus cell 43 side showing the shape of each cam groove
FIG. Straight cam groove 41 in first half 26
Are formed in a linear long hole in the direction along the optical axis.
The cam groove 42 of the variable power transmission cell 34 is
Are formed so as to be orthogonal to That is, the variable power transmission cell 34 accompanies the variable power operation.
The rotational movement is the focus pin 4 of the focus transmission cell 40.
0b.
In FIG. 3, the first half 26 of the fixed cell 25
The straight cam groove 28 and the straight cam groove 41 are formed for convenience of drawing.
The same cross section is shown, but the straight cam groove 28 and the straight
It is located on a section different from that of the cam groove 41. FIG. 9 illustrates the operation of the embodiment shown in FIG.
FIG. In FIG. 9, reference numeral 46 denotes a part shown in FIG.
The cam diagram at the position ∞ of the first group lens 2a
Curve corresponding to the ∞ position cam (hereinafter abbreviated as “∞ curve”).
Similarly, 47 is the closest position (example) of the first group lens 2a.
(E.g., corresponding to subject distance D = 1.2 m)
The curve 48 represents an arbitrary subject distance D (for example, D = 3.0 m).
Etc.) of the focusing lens units 2a and 2b
Changes in focus position, that is, changing the focal length between the wide side and the tele side
Focused music indicating the change of the focus position when changing between
The lines, 49, 50 and 51 are Zp = Zp₀ And each
Of the ∞ curve 46, the focusing curve 48 and the closest curve 47
At the intersection, the value of Sx at these intersections 49-51 is
Each S₁  S₀   , S (e), S_Three It corresponds to. 52, 53
And 54 are similarly Zp = Zp₀ And each curve
46, at the intersection with the focusing curve 48 and the closest curve 47,
The value of Sx at these intersections 52 to 54 is S₀   ,
S (i), S_TwoIt corresponds to. 55 is Zp = Zp₁
 And Sx = S (i), 56 is the variable-power drive
Arrow 57 indicates the direction of the focusing drive.
You. FIG. 10 shows the ∞ curve 46 and the focusing curve 4 in FIG.
8 and the near curve 47 are compared with those of other varifocal lenses.
For ease of comparison with properties, simply formally
FIG. 3 is a diagram drawn by standardizing (normalizing) the data. Note that FIG.
Corresponding parts have the same reference characters allotted and redundant description will be omitted.
I do. The operation of the present embodiment thus constructed will be described.
I will tell. Before describing the overall control operation, the operation of the mechanism shown in FIG.
Explain the work. First, the driving gear 4 is driven by the variable power motor 45.
5a rotates, and is rotated by the gear portion 33a meshing therewith.
The power is transmitted to the variable power cell 32 and the rotation transmission pin 33.
b. The variable power transmission cell 34 and the second group lens connected at b.
2b starts rotating integrally. First group cell 17, fifth
As shown in FIGS. 6 and 4, the group cells 20
The first pin 21 and the third to fifth pins 22 to 24
Straight cam grooves 28, 29, 30, 31 along the optical axis direction, respectively.
Thus, the position in the rotation direction is regulated. Obedience
The rotation of the variable power transmission cell 34 and the variable power cell 32
The first pin 21 and the third to fifth pins 22 to 24 are
According to the rotation angle of the cam groove and the shape of each cam groove 36-39.
On the optical axis. That is, the first lens excluding the second group lens 2b
Each group of the group lens 2a to the fifth group lens 2e has a zooming action.
And move according to the cam diagram shown by the solid line in FIG.
I do. Although the focal length f can be updated by this zooming operation,
At the same time, defocus also occurs, so this must be corrected.
Must. Therefore, the focusing operation will be described below.
The second group lens 2b moves depending on the zooming operation.
do not do. Drive gear 44a by focus motor 44
  Is driven, and this rotational force meshes with the driving gear 44a.
Transmitted to the gear portion 43a of the focus cell 43
And the focus cell 43 rotates, as shown in FIG.
The focus pin 40b is connected to the first half 41 of the fixed cell 25.
The linear cam groove 41 formed on the
The focus transmission cell 40 also rotates because the position is regulated.
Direction, and therefore, as shown in FIG.
The focus pin fitted into the cam groove 43b of the ssel 43
In the figure, the water 40a corresponds to the rotation angle of the cam groove 43b.
A linear motion is made on the optical axis by an amount according to the component force component. That is, the rotational movement of the focus cell 43 is
Focus transfer cell 40 through an aqua spin 40a
Is converted into a linear motion in the direction of the optical axis.
To the variable power transmission cell 34 via the focus pin 40b.
The first group lens 2a and the second group lens 2b are transmitted
Set by the zooming operation described above (however,
2b is fixed) Variable magnification transmission with lens spacing maintained
Since the entire cell 34 moves on the optical axis to the in-focus position,
is there. As already apparent from this description, the variable power transmission
Reach cell 34 is involved in both zooming and focusing operations
You are doing. Note that the first detection by
The change in the output of ZPM8 as the output means is represented by Zp shown in FIG.
  And constitutes a second detecting means by the focusing operation.
The change in the output of FPM7 as the third detecting means is the same
This is Sx shown in FIG. Next, referring to FIG. 1, the whole of the embodiment will be described.
The control operation will be described mainly with reference to FIG. Now, of the variable power lens group 2,
Position, that is, the output of ZPM8 is Zp = Zp₀ And
The positions of the focusing lens groups 2a and 2b,
It is assumed that the output of the FPM 7 is Sx = S (i).
Here, first, the entire system focal length f is changed from the wide side to the tele side.
Activate the magnification up operation to be updated. When the up switch 13 in FIG. 1 is pressed
Includes information on the scaling direction from the drive direction determination unit 15
A start signal (STR) is output. At this point, the initial
Maximum feeding amount calculating section 9 which functions as a condition calculating means
Receives the output (Zp) of ZPM8, performs A / D conversion,
Example: The constant calculator 10 receives the output (Sx) of the FPM 7
A / D conversion is performed. And each value is
Zp = Zp₀ , Sx = S (i). The in-focus position changes with the focal length f.
Varifocal with characteristics as shown in FIG.
In the case of a lens, Zp = Zp according to equation (1).₀ To
The maximum delivery amount Fpx = Fp (i) in this case is obtained. One
That is, the length from the intersection 52 to the intersection 54 in FIG. Therefore, in FIG. 9 which is the present embodiment,
The length from the intersection 52 to the intersection 54 is maximum according to the equation (1).
It can be obtained as the delivery amount Fpx (= Fp (i)).
You. Further, the maximum feed amount calculation unit 9 calculates the maximum feed amount by the equation (2).
Zp = Zp₀ Of the intersection 52 of the ∞ curve 46 at
(Coordinates) is Sx (∞) = S₀   Is calculated as Next, the proportionality constant calculator 10 calculates the S₀
And the maximum feed amount Fp (i) and Sx = S
Calculate the proportionality constant Cfp by (i) and equation (3).
You. The focusing lens system obtained in this wayDefine location
ToFpx = Fp (i), Sx (∞) as initial conditions
= S₀   , Cfp are notations of an initial condition calculating means (not shown).
Is temporarily recorded in the storage means.
It is changed by the above-mentioned information on the zooming direction and the start signal (STR).
The double motor Mz is started in the direction of increasing the magnification. The variable magnification unit moves in the direction of arrow 56 in FIG.
Up switch 13 is turned off when the intersection point 55 is reached.
Assuming that the state has been changed, the scaling controller 16 changes the scaling mode.
Data Mz is stopped. At this point, Zp = Z
p₁ And the focus motor M_F   Still start
Therefore, Sx = S (i) still holds.
Here, similarly to the above, the maximum feeding amount calculation unit 9 calculates Zp = Z
p₁ (1) from the intersection 49 to the intersection 51
The maximum feed amount Fpx = Fp (e), which is the length of
Further, Sx at the intersection 49 of the ∞ curve 46CoordinateInto equation (2)
Therefore, Sx (∞) = S₁ Is calculated as Then, the focus correction calculation unit 11 calculates the S₁ You
And the previously obtained proportional constant Cfp and the above Fp (e)
And the planned in-focus position S indicated by the intersection 50 by the equation (4).
(E) is calculated. Then, the focus control unit 12
Focusing lens unit 2 in the direction indicated by arrow 57 in FIG.
a, 2b to drive the focus motor M_FTo
Control, and the output Sx of the FPM 7 that changes with this
Monitoring is performed via the focus correction calculation unit 11, and the output Sx is S
When x = S (e), the focus motor M_F
  Stops and ends magnification up operation and focus correction operation
I do. Note that the magnification reduction operation is the reverse of the above operation
Therefore, the description is omitted because it can be easily analogized. As described above, in the present embodiment, the second lens unit
Since the lens 2b is fixed to the variable power transmission cell 34,
Varifocal lens, a simple optical system, is even simpler
Have been. In addition, the second lens unit 2b is moved by the variable power operation.
∞ Focus position due to the structure that does not change
Despite having the characteristic that the position changes, by proportional operation
Easily calculate the expected in-focus position and focus on this in-focus position.
There is an advantage that the single lens groups 2a and 2b can be driven. Further, the above-mentioned and the like in the conventional zoom lens
Remove the condition of the amount shift, and
Since the change is made to be the equation (5),
Of the focusing lens units 2a and 2b
The advantage is that it does not grow as necessary. Therefore, the lens outer diameter
Has the advantage of being as small as possible. And apparently (use
Top) focuses once like a conventional zoom lens
Later, even if you change the magnification, the focus moves (blurred).
There are no benefits. The second lens group 2b is connected to a variable power transmission cell.
34, the cell for the second lens group is omitted.
The cam groove, which is difficult to process, is formed in the variable power transmission cell 34.
Need to be implemented, thus simplifying the configuration and reducing costs.
Can be reduced. In addition,
Since it is not necessary to drive the second group lens 2b for zooming,
The frictional force is reduced by the
Can be realized. In addition, a conventional cam is used to compensate for mechanical focusing.
Since the positive is performed electrically, the outer diameter of the lens
Can be made as small as possible, and the lens barrel configuration can be simplified.
The motor that drives the focusing lens group has a small capacity.
As a result, miniaturization, weight reduction, and cost reduction of the entire device have been realized.
There are advantages. In particular, use the camera and this device in conjunction
In this case, the AF circuit of the camera can be shared.
Further, there is an advantage that the cost can be reduced. The present invention is limited to the above embodiment.
Without departing from the gist, various
Modifications can be made. For example, the variable power transmission cell 3
The cell fixed to 4 may be the first group cell 17.
Also, it is involved in both the zooming operation and the focusing operation.
Is a variable-magnification transmission cell 34, as shown in FIG.
The focus counter 6 and the FPM 7 have a driving gear 44a.
The focus cell 43 is not limited to the example in which the focus cell 43 is connected.
And the amount of movement of the focus transmission cell 40 in the optical axis direction is detected.
May be configured.That is, these focus
The counter 6 and the FPM 7 are positioned from the zoom lens system.
Position may be detected.
That is, the part that is fixed to the camera body and does not move)
The position from may be detected. Similarly, the ZPM 8 is driven by a driving gear 45a.
  Is not limited to the configuration in which the variable magnification cell 32 or
Is the rotation angle of the variable power transmission cell 34 or the third group cell 19
To detect the amount of movement in the optical axis direction of any of the fifth group cells 21
It may be configured to output. Further, the focus motor 44 and the variable power
Motor 45 includes driving gears 44a and 45a, respectively.
May be driven via a speed reduction mechanism without being directly connected to
No. The expected in-focus position S (e) is the third
Limited to comparison with the output Sx of FPM7 as the detection means
Of the focus counter 6 as the fourth detecting means.
It may be compared with the output Dfc, that is, Sx = Df
c, the focus motor M_F   I'll stop
It may be configured as follows. In general,threeFPM7 as a means of detecting
Potentiometer,As a fourth detection meansfocus
Each of the counters 6 is composed of a rotary encoder or the like.
In this case, since the accuracy of the focus counter 6 is higher,
In the above case, the driving to the expected in-focus position S (e) is more accurate.
There are advantages. The calculation based on equation (2) is performed, for example, as shown in FIG.
Is divided into four parts by the value of Zp.
Approximating each section with a straight line,
Therefore, Sx (∞) may be calculated. For example, f = 35
The value of Zp corresponding to mm is set to 0, and f = 135 mm
The value of Zp to be set to 31 is
The value of Fp is set to 0, and the value of Fp corresponding to the ∞ position is set to 3.
1, the approximate expression of each section is as follows.
You. Zp ≦ 3 Fp = 31 Also, formulas (1) and (2) are tailored.
Equation Fpx = a₀+ A₁ Zp + a_Two Zp^Two... and then
Is also good. Where a₀  , A₁ , A_Two , …… is at design time
It is a setting constant determined in. Also, generally, the tele side and the wide side are stopped.
Position, the pressure angle between the zoom cam and the stop member,
From the problem of stop strength, the calculation formula such as formula (1)
In some cases, approximation cannot be made on the telephoto side and the wide side. So
In the case of, the zone of Zp is divided into three zones,
This is done by creating an approximate expression by dividing into zones
be able to. Equations (1) and (2) are also used in the calculation.
The data is stored in the CPU and the ROM without limitation.
You can also. [0067] As described in detail above, according to the present invention,
If you use a variable power lens that causes
Calculate and store the initial conditions of the focusing lens system in advance
By doing so, the arithmetic processing becomes more efficient and the
Variable power lens device that can quickly and accurately correct this
Can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an overall configuration of an embodiment of a varifocal lens control device according to the present invention. FIG. 2 is a diagram showing a change in a focal length f to be set, which is a characteristic of a varifocal lens used in the present invention, and how each lens group moves. FIG. 3 is a vertical sectional side view showing a specific configuration of a variable magnification drive unit and a focus drive unit in FIG. 1 as a main part of the present invention. FIG. 4 is a plan view showing respective cam shapes and relationships between a straight cam groove of a fixed cell and a variable power cell. FIG. 5 is an enlarged plan view showing a connecting portion between the variable power cell and the variable power transmission cell, and a cross-sectional view taken along the line AA 'of the plan view. FIG. 6 is a plan view showing respective cam shapes and relationships between a fixed cell and a variable power transmission cell. FIG. 7 is a plan view illustrating a cam shape of a focus cell and a directional relationship with an optical axis. FIG. 8 is a plan view showing respective cam shapes of a focus cell, a fixed cell, and a variable power transmission cell. FIG. 9 is a diagram for explaining the overall operation of the embodiment of FIG. 1; FIG. 10 is a diagram in which the diagram of FIG. 9 is formally approximated to the characteristics of another varifocal lens. [Description of Signs] 1 Optical axis 2 Variable power lens groups 2a to 2e First to fifth lens groups 3 Film surface 4 Variable power drive unit 5 Focus drive unit 6 Focus counter 7 Group lens unit position detector (FPM) 8 Focal length detector (ZPM) 9 Maximum feeding amount calculation unit 10 Proportional constant calculation unit 11 Focus correction calculation unit 12 Focus control unit 13 Magnification up switch (Up switch) 14 Magnification down switch (Down switch) 15 Driving direction determination unit 16 magnification change control unit Mz, 45 zooming motor _M F, 44 focus motor + V power source 17 first group cells 18-20 group 3 cells to the fifth group cell 21 first pin 22-24 third pin-fifth pin 25 Fixed cell 26 Front half part 27 Rear half part 28 to 31, 41 Linear cam groove 32 of fixed cell Variable power cell 33a Gear part 33b Rotation transmission pin 34 Variable power transmission cell 3 4a Notch 35 Fixed part 36, 42 Cam groove 37-39 of variable power transmission cell Cam groove 40 of variable power cell Focus transmission cell 40a, 40b Focus pin 43 Focus cell 46 ∞Position cam corresponding curve (∞ curve) 47 Closest curve 48 Focusing curve 49-55 Intersection 56 Arrow indicating the direction of the variable power drive 57 Arrow indicating the direction of the focus drive

Claims (1)

(57) [Claims] A variable power optical system comprising a variable power lens system having a variable power function and a focusing lens system having a focusing function, which are disposed on the same optical axis, wherein a subject distance and an optical axis of the focusing lens system are provided. The relationship with the amount of extension in the direction differs at the magnification position within the magnification range, and the imaging position shift is caused by a magnification operation of updating from an arbitrary first focal length to an arbitrary second focal length within the magnification range. In the resulting variable power lens device, first detecting means for detecting the position of the variable power lens system, second detecting means for detecting the position of the focusing lens system, and Initial condition calculating means for calculating initial conditions for defining the position of the focusing lens system corresponding to the position of the variable power lens system based on the outputs of the first and second detecting means at the start of magnification, During the scaling operation, the initial condition calculating means A variable-magnification focusing correction control means for controlling the position of the focusing lens system in order to correct the imaging position shift accompanying the magnification operation based on the output of the first and second detection means. However, the above-mentioned initial condition calculation means includes a position
The maximum extension of the focusing lens system, focus position information and
And initial conditions for the proportionality constants associated with both
A vari-focal lens device comprising arithmetic means . 2. Mainly has a zoom function arranged on the same optical axis
From zoom lens system and focusing lens system with focusing function
Variable magnification optical system, the subject distance and the focusing lens
The relationship with the extension amount in the optical axis direction of the system is the magnification position within the zoom range.
And any first focal length within the zoom range
Is updated by the zoom operation to update the focal length to an arbitrary second focal length.
In a variable power lens apparatus which causes an image position shift, first detecting means for detecting the position of the variable power lens system, second detecting means for detecting the position of the focusing lens system, and Prior to the above,
And the variable power lens based on the output of the second detecting means.
Defines the position of the focusing lens system corresponding to the position of the system
Initial condition calculating means for calculating an initial condition; and the initial condition calculating means and
And the output of the second detection means.
Position of the focusing lens system in order to correct the image position shift.
Has Henbaigoase correction control means for controlling the location, the second detecting means includes a third detecting means for detecting the position from the variable power lens system of the focusing lens system, zooming operation consists of a fourth detecting means for detecting the relative position from the starting position, the above-mentioned initial condition calculating means, using the output of the third detecting means, the said Henbaigoase correction control means, said first it comprises using the output of the fourth detector zoom lens device. 3. Henbaigoase correction position control of the focusing lens system of the control unit, the variable magnifying lens apparatus according to claim 1 or 2, characterized in that the zooming operation start at a predetermined time interval. 4. The position control of the focusing lens system according Henbaigoase correction control unit, according to claim 1 or 2 from the zooming operation starts, the output of the first detecting means is characterized in that it is carried out in which varies a predetermined amount
2. The variable power lens device according to 1. 5. The initial condition calculating means includes calculating means for obtaining initial conditions of a maximum extension amount of the focusing lens system related to the position of the zoom lens system, focus position information, and a proportional constant related to both of them. Item 3. The variable power lens device according to Item 2 .