JP2802896B2 - Variable-lens control unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to a variable power lens.Control deviceTo
More specifically, a variable power lens arranged on the same optical axis
Zooming operation with zoom lens system consisting of lens group and focusing lens group
Related to the variable power lens control device
Is what you do. [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. And the zoom lens
This focus for the same subject distance in the zoom range
The moving amount of the single lens group is almost the same (hereinafter, this
This is called "equivalent movement")
Moving member for focusing lens group with subject distance scale
(Distance ring), while being located adjacent to it
Just attach an index to the fixed ring to
It is not necessary to change the subject distance scale according to
There are advantages. However, the lens structure of the variable power optical system described above.
The inner focusing method and the
And rear focusing zoom lenses
Optical design is performed under the condition that
In this case, there is a problem that the lens configuration becomes complicated.
Furthermore, the amount of movement of the focusing lens group on the wide-angle side
(Delivery amount) becomes unnecessarily large.
This also increases the outer diameter of the lens,
There is also a problem that the lens and the lens barrel become heavy. [0003] 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. The present applicant has solved the above-mentioned problems.
Invention (hereinafter referred to as a varifocal lens control device)
"Invention of prior application") is disclosed in Japanese Patent Application No. 62-013.
No. 345. [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 normally
Cam frame for driving the focusing lens group (hereinafter referred to as “focus
Transfer) in the optical axis direction by the cam groove formed in the
The zoom lens group drive frame (hereinafter referred to as the “magnification
Predetermined) by a plurality of cam grooves formed in
The lens interval is set. Therefore,
To the cam frame for driving the double lens group (hereinafter referred to as "variable cell")
On the other hand, each focus
Since the lens groups are combined, it is inevitable
The mechanism that drives both the lens group and the focusing lens group
It becomes complicated, simplifies the configuration, reduces costs, compacts
This has been an obstacle to the development of [0008] The present invention has been made in view of the above circumstances.
Therefore, the purpose is to make it cheap and small
Also a simple optical systemlensWhile using
Automatically adjusts the resulting image position shift in combination with the existing AF function
Zoom lens that can quickly and accurately correctcontrolEquipment
To provide. [0009] [Means for Solving the Problems]UpAchieve the stated purposeSuta
Therefore, the invention (first invention) described in claim 1 is the same
Arranged on the optical axisZooming functionHaveVariable power lens groupAnd
AndZooming and focusing functionsHaveAt least two or more lenses
Focusing lens groupVariable magnification optical system
And the distance between the subject and the focusing lens group in the optical axis direction.
The relationship with the output amount differs at the magnification position within the zoom range, and
Any second focal length from any first focal length within the zoom range.
An imaging position shift occurs due to the scaling operation that updates to the point distance.
In the control device of the variable power lens device,Above zoom lens
A variable power lens group position detecting means for detecting the position of the group,Variable magnification
In operation,When the zoom lens group is moved in the optical axis direction,
Sometimes the above focusing lens groupThe above two or more lenses
Without moving at least one of the lenses
The zoom lens is moved by moving the lens relatively.
Change the overall focal lengthVariable magnification driving means and the focusing
Lens groupThe two or more lenses that make upOptical axis direction
Focusing drive means for driving the zoom lens group
Output means outputBased on the aboveCalculate the amount of movement of the focusing lens group
OutAnd controls the focusing drive means based on the calculation result.
Variable magnification focusing correction control means,With, At variable power operationTo
IsDriving the zoom lens group by the zoom driving means.
andBy the above-mentioned variable power focusing correction control meansFocus driving means
In order to correct the above image position shiftAbove focus lens
Drive groupMove, At the time of focusing operation, it is combined with the existing AF function.
Drive the focusing lens group by the focusing driving means
It is characterized by doing. [0010]More specifically, the zoom lens group position detection
The position detection by the projection means detects the position from the immovable part of the camera.
DetectIt is characterized by doing. [0011]To achieve the above object,
The invention described in (3) (the second invention) is performed during focusing operation.
Consists of multiple lenses in combination with the existing AF function
Automatic focus adjustment by driving and controlling the focusing lens group
While achieving the object distance and the focusing lens group.
The relationship with the extension amount in the optical axis direction differs at the magnification position within the magnification range.
From any first focal length within the zoom range.
Image position by the zoom operation to update to the desired second focal length
In a camera with a variable power optical system that causes displacement,
At the time of double operation,When the zoom lens group is moved in the optical axis direction,
At the same time, the above focusing lens groupTwo or more of the above
Without moving at least one of the lenses
The above-mentioned variable power optics by moving the lens relatively
Change the focal length of the entire systemVariable magnification driving means and
Focal lens groupThe two or more lenses that make upoptical axis
Focus driving means for driving in the direction,With variable power operation
The distance between the multiple lenses of the focusing lens group
While holding the camera, the above-mentioned image position shift correction and automatic focus adjustment
Drives the focusing lens group in the optical axis direction to achieveDo
It is characterized by the following. [0012]More specifically, the variable magnification driving means
Focusing lens group position that detects the position of the moving focusing lens group
Position detecting means and an output of the focusing lens group position detecting means.
The above focusing lens group keeps the distance between a plurality of lenses.
Should be given to the focus driving means that is driven in the optical axis direction
A variable-power focusing correction controller that calculates the amount of movement of the focusing lens group
With stepsIt is characterized by doing. [0013] [Action] The variable power driving means moves the variable power lens group in the optical axis direction.
At the same time as changing the focal length of the focusing lens group
At least one or more lenses in the focusing lens group to cause
The group is moved in the optical axis direction. And the focus driving means is
While maintaining the focal length of multiple focusing lens groups constant, light
Drive in the axial direction. The variable power focusing correction control means includes a variable power lens.
From the output of the lens group position detecting means, for example,
The amount of movement corresponding to the imaging position shift due to the magnification change is calculated.
This variable power optical system is operated by the variable power driving means during the variable power operation.
Drive the variable-power lens group, and
It is configured to drive the focusing lens group. And
At the time of focusing operation, in combination with the existing AF functionFocus lens
While maintaining the focal length of the lens groupFocusing by focusing drive means
Lens groupIn the direction of the optical axisI try to drive. [0015] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
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, 2e are
First lens group consisting of single or multiple lenses
Lens, the second group lens, the third group lens, the fourth group lens and
This is the fifth lens unit. Then, the first group lens 2a and the
The two-group lens 2b is used to form a focusing lens system.
A caching lens group is formed. The first and second lens groups
Lenses 2a and 2b, the third lens group 2c to the fifth lens group
2e constitutes the variable power lens group 2. The second
Magnification configuration with zoom lens group 2 excluding group lens 2b
Make up a group. In addition, the above-mentioned zoom
The total focal length of the double optical system is f. 3 is the film surface,
Reference numeral 4 denotes a telephoto-side focal length in which the focal length f of the entire system is the longest focal length.
Shortest focus from point distance (hereinafter simply abbreviated as "tele side")
The focal length on the wide-angle side as the distance (hereinafter simply referred to as “wide side”)
Abbreviated) to set any focal length between
A zooming motor as a zooming drive means for driving the zooming configuration group.
Motor Mz and a variable-magnification drive unit comprising a mechanism unit described later.
You. 5 is from infinity during focusing operationShortest shooting distance
ChiInfinity on the optical axis 1 corresponding to the subject distance to the nearest
From position (∞ position)Shortest shooting distance position, ieTo the closest position
The first group lens 2a and the second group lens
Drive the lens 2b (specifically, the first group lens 2a and the second
With the distance between the group lenses 2b kept constant,
Focus motor as focusing drive means
M_F And a focus drive unit comprising a mechanism unit described later.
is there. 6 and 7 are the first group lens 2a and
Drive to the focus drive unit 5 together with the second group lens 2b.
The slit disk 6a is rotationally driven.
Rotation from the photo interrupter 6b
A pulse proportional to the number is generated, and the first group lens 2a and the
Focuser for detecting the amount of movement of the second lens unit 2b on the optical axis 1
Counter 7 is the first group lens 2a and the second group lens.
The position of the lens 2b on the optical axis is detected and proportional to the position.
The focus level that outputs the voltage as focus position information Sx
LensgroupFocusing lens group position detector as position detecting means
(Hereinafter abbreviated as “FPM”). 8 is a variable magnification group
Is driven by the variable power driving unit 4 to change the position of the variable power lens system.
ElectricallyVoltage detected and proportional to the focal length f of the whole system
Is output as focal length information Zp.
A variable power lens group position detector (hereinafter referred to as “ZP
M ”), 9 receives the focal length information Zp
After A / D conversion, it is very close to ∞ position in Zp
Of the first group lens 2a and the second group lens 2b up to the position
The amount of travel (ieMaximum feed amount, below, simply ``Feeding amount"When
Call) The maximum feed amount calculation unit for calculating Fpx is 10
Output Fpx of maximum feeding amount calculation unit 9 and focus of FPM7
In response to the output Sx as position information, the output Sx is converted to A /
After D-conversion, these ratios are calculated, and a proportional constant Cfp is output.
It is a proportional constant calculation unit that operates. 11 is the above three outputs F
px, Cfp, and Sx, the correction amount Dfp for focusing
A focus correction calculating unit for calculating the focus counter 6;
Output Dfc and the correction amount of the focus correction calculation unit 11 described above.
The focus driver 5 is controlled by receiving the corresponding output Dfp.
It is a focus control unit. 13 to 15 constitute start-up means
13 and 14 are external devices for starting the zoom operation.
A variable magnification switch consisting of operable push button switches,
13 is a magnification up switch (hereinafter simply referred to as “up switch”).
), 14 is a magnification down switch (hereinafter simply referred to as
"Down switch"), 15 are these switches
In response to the outputs of 13 and 14, the rotation direction of the variable power motor Mz is changed.
After determining the driving direction (STR) to output the start signal (STR)
Receiving unit 16 receives the start signal STR and the output Fpx.
It is a variable power control section that controls the variable power drive section 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. [0017]Therefore, the variable power focusing correction control means outputs the result
From the output Zp of the ZPM 8
Movement amount to bring all focusing groups into focus
It has a function of calculating Dfp. And the above variable power drive
The unit 4 moves the zoom lens unit 2 in the optical axis direction at the same time
Only the focusing lens group 2a is moved in the optical axis direction
It is configured so that [0018]In addition, the focusing drive unit 5
Keeping the focal length of the casing lens group in the optical axis direction
It is composed.In addition, + V indicates the power supply, and input / output of each part.
The power relationship shows only the main signal. Now, in the operation executed by each of the above-described operation units,
The contents and the arithmetic expressions related thereto are shown below. 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
To Zp and the lens-specific constants of the variable power optical system, respectively.C
₁ , C _Two , C _Three   And when                 C_Two   Fpx = ───────── + C_Three              (1)   Zp + C ₁ 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,                   A₁   Sx (∞) = ─────── + A_Two          (2)   Zp + A ₀ It is calculated by the following formula. Here, Zp is the above Z
The output of PM8,A ₀ , A ₁ , A _Two Is the same as above
This 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             S (i)   Cfp = ─────── (3)           Fp (i) 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 Sx (∞) aboveZp ₁ ,S ₁ To be
WhenS (e) = Cfp · Fp (e) + S ₁ (4) The calculation for obtaining the expected focus position S (e) is performed. Was
However, Fp (e) is Zp =Zp ₁ Into equation (1)
Value. The basis of the concept of the present invention is as follows.
From the equation (5), the above equations (1) to (4) are obtained from the equation (5).
Is derived. [0024]D = (C ₀ ・ Zp + C ₁ ) ・ Sx + C _Two (5) Where D is the subject distanceC ₀ , C ₁ , C _Two Is at design time
It is a setting constant determined in. That is, in the equation (5), the subject distance D is
A means for controlling Zp and Sx so as not to change is realized.
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 positively removed the condition of equal displacement
It can be said that it is a theory. 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
  IsFocusing lens group positionThe output of the detection means
Focus position information Sx.
Focusing lens group (first group lens 2a and second lens
Extension amount (movement) of the group lens 2b) corresponding to the subject distance
Amount). Zp is alsoZoom lens group positionInspection
This focal length information Zp, which is the output of the output means,
On the surface side, the amount of movement of the variable power lens unit 2 due to the variable power operation is set to the fourth group.
The lens 2d is shown as a representative. Also this figure
1 is the optical axis 1 'on the wide side,
The optical axis on the side. 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, reference numerals 17 and 18 to 20 denote:
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
The grooves, 37 to 39, are similarly connected to the third pin 22 to the fifth pin 24.
Each of the variable magnification cells 32 has a width that can be fitted into each.
The perforated cam groove 40 is a front part 2 of the fixed cell 25.
6, which is fitted around the outer periphery of the optical disk 6 so as to be movable only in the optical axis direction.
The waste transfer cells, 40a and 40b,
It is orthogonal to the optical axis 1 from the outer and inner circumferences of the waste transfer cell 40.
Focus pins 41 and
And 42 are fitted with the focus pins 40b, respectively.
With a width that can fit on the first half 26 of the fixed cell 25 and
The linear cam groove and the
And the cam groove 43 on the outer periphery of the focus transmission cell 40.
A fan that is rotatably fitted and whose movement in the optical axis direction is restricted.
The focus cell 43a is located after the focus cell 43.
Gear formed on the outer periphery of the flange provided at the end
The portion 43b can be fitted with the focus pin 40a.
Cam formed on the focus cell 43 with a width
The groove 44 is the focus motor M described with reference to FIG._F, 44
a is the focus motor M_FDriven by focus
A driving gear meshing with the gear portion 43a of the cell 43;
In the variable magnification motor Mz, 45a is a gear portion 3 of the variable magnification 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 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 (a)
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 In other words, the variable power transmission cell
The rotation movement accompanying the magnification change operation of the focus transmission cell 4
Do not be restricted by the 0 focus pin 40b
Is configured. Note that, in FIG.
Straight cam groove 28 and straight cam groove in front half 26
41 is shown as the same cross section for convenience of drawing,
The linear cam groove 28 and the linear cam groove 41 are located at different cross sections.
ing. 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 the subject distance D = 1.2 m)
The near curve 48 represents an arbitrary object distance D (for example, D = 3.0).
  m) focusing lenses 2a, 2b
  Changes the focal position, i.e.
This indicates the change in the in-focus position when changing between
The focus curves, 49, 50 and 51 are Zp =Zp ₁ And it
The ∞ curve 46, the focusing curve 48, and the closest curve 47, respectively.
At the intersection with, the value of Sx at these intersections 49-51 is
EachS ₁   , S (e), and S3.
52, 53 and 54 are similarly Zp =Zp ₀ And it
Each of the curve 46, the focusing curve 48 and the closest curve 47
At the intersections, the values of Sx at these intersections 52 to 54 are respectively
ReS ₀   , S (i), and S2. 55 is Z
p =Zp ₁ And Sx = S (i), 56
Arrow indicating double drive direction, 57 indicates focus drive direction
It is an arrow. 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 second group lens 2b
  Of the first group lens 2a to the fifth group lens 2e excluding
Each group is subjected to a zooming action, and the cam shown by the solid line in FIG.
Move according to the diagram. The focal length is determined by this zooming operation.
f can be updated, but at the same time a focus shift occurs.
Must compensate for this. So next, focus on
I will talk about it. Incidentally, the second lens unit 2b performs the above-described zooming operation.
Does not move. The driving gear 4 is driven by the focus motor 44.
4a is driven, and the rotational force is applied to the driving gear 44a.
Transmitted to the gear portion 43a of the focus cell 43 meshing with
Then, 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. Toes
The rotational movement of the focus cell 43 is
a in the optical axis direction of the focus transmission cell 40
Is converted into motion, and this linear motion is
40b to the variable power transmission cell 34,
The lens 2a and the second group lens 2b perform the above-described zooming operation.
(However, the second group lens 2b is not
Movement) The entire magnification transmission cell 34 with the lens interval maintained.
Moves on the optical axis to the in-focus position. This theory
As is clear from the description, the variable power transmission cell 34 is variable power.
And focus operation.
You. Note that the change in the output of the ZPM 8 due to the above magnification operation is shown in FIG.
Zp shown in FIG. 2 and the FPM 7
The change in the output is also Sx shown in FIG. Next, referring to FIG. 1, the whole of this 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 = Zp₀And
Of the focusing lens groups 2a and 2b, ie, FPM
7 is Sx = S (i). Where
Instead of updating the focal length f from the wide side to the tele side
Activate the rate up operation. Up switch 13 in FIG.
Is pressed, the driving direction judgment unit 15
An activation signal (STR) including direction information is output. this
At this point, the maximum functioning as initial condition calculation means
The feed amount calculation unit 9 receives the output (Zp) of ZPM 8 and
D conversion, and the proportionality constant calculator 10 outputs the FPM7 output (Sx
 ) And perform A / D conversion. And each value is
As described above, Zp = Zp₀, Sx = S (i). ∞ position
FIG. 10 shows that the in-focus position does not change with the focal length f.
In the case of a varifocal lens having such characteristics,
According to the equation (1), Zp = Zp₀Maximum feed amount Fpx at
Fp (i) is required. That is, intersection 52 to intersection 5 in FIG.
Length up to 4. Therefore, FIG.
The length from intersection 52 to intersection 54 according to equation (1)
Can be obtained as the maximum feed amount Fpx (= Fp (i)).
You. Further, the maximum feed amount calculation unit 9 calculates the maximum feed amount by the equation (2).
Zp = Zp₀At the position of the intersection 52 of the
Mark) is Sx (∞) = S₀ Is calculated as Next, the proportional constant
The arithmetic unit 10 calculates the S₀ And the maximum feed amount Fp (i)
Further, the proportionality constant Cfp is calculated by Sx = S (i) and equation (3).
calculate. The initial condition of the focusing lens system obtained in this way
Fpx = Fp (i), Sx (∞) = S₀ , Cfp
Is temporarily stored in the storage means of the initial condition calculation means (not shown).
Then, the zooming control unit 16 controls the zooming direction as described above.
Double the variable-power motor Mz by the information and the start signal (STR)
Start in the direction of increasing the rate. The variable power group is indicated by an arrow in FIG.
When it moves in the direction of 56 and reaches the intersection 55,
If the switch 13 is turned off,
The control unit 16 stops the variable power motor Mz. At this point
And Zp = Zp₁And the focus motor M_F Is
Since it has not started yet, Sx = S (i)
You. Here, similarly to the above, the maximum feeding amount calculation unit 9 determines that Zp =
Zp₁(1) from the intersection 49 to the intersection 51
The maximum feed amount Fpx = Fp (e), which is the length of
ＳSx of intersection 49 of curve 46CoordinateIs given by S
x (∞) = S₁ Is calculated as And the focus correction calculation unit 1
1 is this S₁ And the previously obtained proportionality constant Cfp and
It will be indicated at the intersection 50 by the above Fp (e) and the equation (4).
The in-focus position S (e) is calculated. And the focus control unit 1
2 is a focusing lens in a direction indicated by an arrow 57 in FIG.
Focus motor M so as to drive the lens groups 2a and 2b._F
And the output Sx of the FPM 7 that changes with this
The output Sx is monitored via the focusing correction calculation unit 11 and
= S (e) when the focus motor M_F Stop
Then, the magnification increasing operation and the focus correction operation are completed.
Note that the magnification reduction operation is just the opposite of the above operation,
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.
The advantage is that the single lens groups 2a and 2b can be driven.
You. 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 unit 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. EspeciallyHas AF functionCamera and this device
When the camera is used in conjunction with the
Can useTogether with the in-focus position calculated by the AF circuit of the camera
The amount of movement up to the position is calculated by the compensation
It is possible to share the focus driving means by making it correspond to the positive amount
it canTherefore, the cost can be further reduced.
There is a point. The present invention is limited to the above embodiment.
Without departing from the gist, various
Modifications can be made. For example, a cell fixed to the variable power transmission cell 34
May be the first group cell 17. Further, it is involved in both the zooming operation and the focusing operation.
What is shown in FIG. 3 is the variable power transmission cell 34.
As described above, the focus counter 6 and the FPM 7
The focus is not limited to the example of connecting to the
Movement of the cell 43 and the focus transmission cell 40 in the optical axis direction
It may be configured to detect the amount.That is, these
The focus counter 6 and the FPM 7 are a variable power lens system.
Position from the camera may be detected.
Part (that is, fixed to the camera body and
May be detected. Similarly, the ZPM 8 has 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 expressed by FPM
7, not only the focus count but also the focus count.
May be compared with the output Dfc of the data 6, ie, Sx =
  When Dfc is reached, the focus motor M_FStop
You may comprise so that it may be. Generally, the FPM 7 is connected to a potentiometer,
Each of the focus counters 6 is composed of a rotary encoder or the like.
The focus counter 6 is more accurate
In the above case, the driving to the expected focus position S (e) is better.
It has the advantage of being more accurate. The calculation by the 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 0, and f = 135 mm
The corresponding Zp value is set to 31 and it corresponds to the closest position
And the value of Fp corresponding to the ∞ position
Is 31, the approximate expression for each section is as follows:
Become. Zp ≦ 3 Fp = 31                                             2   4 ≦ Zp ≦ 7 Fp = 29−─────── (Zp−4)                                             4                                             6   8 ≦ Zp ≦ 15 Fp = 27−─────── (Zp−8)                                             8                                             21   16 ≦ Zp ≦ 31 Fp = 21−─────── (Zp−16)                                             16 Also, formulas (1) and (2) are tailored.
Equation Fpx =a ₀ + A ₁ Zp + a _Two Zp ^Two ……even if
Good. Where a₀  , A₁  , A_Two  , …… is at design time
It is a setting constant determined in. In general, 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. [0056] As described in detail above, according to the present invention,
If it is inexpensive, use a compact and simple zoom lens
And can correct the imaging position shift due to zooming by itself.
Together with the existing AF function to automatically
A variable power lens control device that can dynamically and quickly and accurately focus.
Can be provided. In particular, according to the present invention, A
By applying to a camera with F function,
While reducing the cost of the functionality of cameras with AF function
To provide a variable power lens control device which can be significantly improved.
Can be. According to the present invention, the functions of zooming and focusing are provided.
Do not move at least one lens groupWhat
By makingOf the lens groupFixedMeans are omitted
And the troublesome formation of cam grooves can be omitted.
Therefore, a change that can realize a simplified configuration and reduced cost is realized.
A lens magnification control device 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 the 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 Drive 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 a 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02B 7/08 G02B 7/28 G03B 3/10 G03B 13/34

Claims (1)

(57) [Claims] 1.Arranged on the same optical axisZooming functionHaveMagnifying lens
GroupandZooming and focusing functionsHaveAt least two
Focusing lens group consisting of the upper lens groupVariable magnification composed of
An optical system, including an object distance and an optical axis of the focusing lens group.
The relationship with the feeding amount in the direction differs at the magnification position in the zoom range.
And from any first focal length within the zoom range
Is changed to the second focal length by the zooming operation.
In the control device of the variable power lens device that causes the displacement, Magnification lens group position detection for detecting the position of the magnification lens group
Delivery means,During zoom operation, Move the zoom lens group in the optical axis direction
At the same time, the above focusing lens groupMake up the above two or more
Without moving at least one of the lenses
By moving the lens relatively,
Change the focal length of the whole systemVariable magnification driving means; Above focusing lens groupTwo or more lenses that compose
ToFocusing drive means for driving in the optical axis direction; Output of the zoom lens group position detecting meansBased on the aboveCombination
Calculate the amount of movement of the focus lens groupAnd based on the calculation results
Controls the focus drive meansVariable magnification focusing correction control means,With , At variable power operationTo, The variable magnification driving means
Drive groupandBy the above-mentioned variable power focusing correction control meansthe above
In order to correct the above image position shift by controlling the focusing drive means
Drive the above focusing lens groupMove, At the time of focusing operation, the above focusing is performed in combination with the existing AF function.
The focusing lens group is driven by a driving unit.
Variable magnification lens control device. 2. The position detection by the zoom lens group position
LaImmovable part ofDetecting the position from
Claim 1ToThe variable magnification lens control device according to the above. 3. At the time of focusing operation, in combination with the existing AF functionMultiple
Consisting of lensesBy driving and controlling the focusing lens group
To achieve automatic focus adjustmentWith the subject distance and above
The relationship with the extension amount of the focusing lens group in the optical axis direction varies. Area
And any first position within the magnification range
Variable power to update from the focal length of the image to an arbitrary second focal length
Has a variable magnification optical system that causes image position shift due to workMosquito
Mela,During zoom operation, Move the zoom lens group in the optical axis direction
At the same time, the above focusing lens groupMake up the above two or more
Without moving at least one of the lenses
By moving the lens relatively,
Change the focal length of the whole systemVariable magnification driving means; Above focusing lens groupTwo or more lenses that compose
ToFocusing drive means for driving in the optical axis direction;With The above focusing lens group changed during zooming operationMake upMultiple
While keeping the distance between the lensesIn order to achieve the above image position shift correction and automatic focus adjustment
The above focusing lens group Driving in the optical axis direction
Variable magnification lens control device. 4. Position of the focusing lens group moved by the variable power drive
Focusing lens group position detecting means for detecting The output of the focusing lens group position detecting meansBased on the aboveFocus
Lens groupMultipleOptical axis direction while maintaining the distance between the lenses
Drive toThe focusing lens group to be given to the focusing driving means
ofVariable power focusing correction control means for calculating the amount of movementfurtherYes
Claims characterized byTo 3Variable power lens control described
apparatus.