JPS61113016A - Range adjusting device of zoom lens - Google Patents

Abstract

PURPOSE:To correct excellently the curvature of an image plane by eliminating the need to move forth an optical system for the 1st lens group (normal area adjustment) when a range adjustment is made in a macro area. CONSTITUTION:When the range adjustment is made in the macro area, the cam part 15B for the macro area range adjustment of the 3rd cam groove 15 is slanted in the opposite direction of a zoom power varying cam part 15A so that the 1st lens group L1 does not move from a normal range position D in a telephoto state, and consequently the movement extent (x) of the 1st lens L1 and the extension extent (y) by a helicoid screw 5 cancel each other. Further 2nd lens group L2 is displaced greatly to left by the macro area range adjusting cam part 13B of the 1st cam groove 13 and the 3rd lens group L3 and the 4th lens L4 are displaced to right at the same time to make a range adjustment in the macro area up to a extremely short range position without deteriorating aberrations of the optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a distance adjusting device for a zoom lens, and particularly to a distance adjusting device for a zoom lens that can photograph beyond a normal photographing area to a nearby macro area.

[Background of the invention]

Various distance adjustment devices for zoom lenses capable of adjusting the distance in a so-called macro area 1 which is closer than the close range position of the normal photographing area that enables zoom magnification have been proposed and are already known. For example, in addition to the normal area adjustment operation member rotatably provided on the outer periphery of a fixed lens barrel, a zoom magnification operation member that rotates to change the zoom magnification is moved straight in the optical axis direction, and A distance adjustment device for a zoom lens was developed in 1973, which allows distance adjustment in the macro area by moving a part of a movable lens group in the optical axis direction.
It is disclosed in the patent publication No.-23811. In addition, a zoom lens that enables distance adjustment in the macro range by rotating a rotatable zoom magnification operation member beyond the rotation range of the zoom magnification adjustment member was also developed by Tokuko Sho 51-1.
It is known from patent publication No. 7045.

However, all of the above zoom lenses are provided with both a distance adjustment member for the normal photographic area and a distance adjustment operation member for the macro area (an operation member that also functions as a zoom magnification changer). Therefore, in this type of known distance adjustment device, when shooting from a normal shooting area to a macro area, or vice versa, it is necessary to switch both operating members each time. h
Therefore, the operation for adjusting the distance is complicated, and not only is it impossible to quickly adjust the distance, but also the distance adjustment becomes unlucky, so there is a risk of missing a photo opportunity when photographing a moving object where the distance gradually changes.

On the other hand, there are also zoom lenses that can change the zoom magnification and adjust the distance from the normal shooting area to the macro area with a single operating member, such as those disclosed in JP-A-54-24623 and JP-A-56-83708. It has already been published in the published patent publication. In these publicly available zoom lenses, the distance can be adjusted in the normal shooting area by rotating the operating member, and furthermore, the distance can be controlled in the macro area by rotating beyond the normal shooting area. be. However, in the embodiments shown in these published patent publications, when adjusting the distance in the macro area, along with the movement of the macro area adjustment lens that constitutes a part of the zoom magnification change movable lens, Normally, the lens for adjusting the candy area is extended far beyond the close range position, which not only increases the lens aperture but also increases the aberrations of the optical system, especially the curvature of field.

[Purpose of the invention]

The present invention solves the above-mentioned drawbacks of conventional zoom lenses, allows distance adjustment in the macro area quickly and easily following distance adjustment in the normal shooting area, and further improves aberration correction, especially in the macro area. It is an object of the present invention to provide a distance adjustment device for a zoom lens that can satisfactorily correct the curvature of an image plane.

[Summary of the invention]

In order to achieve the above object, the present invention moves the optical system for normal area adjustment in the optical axis direction by rotating an operating member to adjust the distance in the normal shooting area, and then rotates the optical system beyond the normal shooting area. In a zoom lens that allows distance adjustment in a nearby macro area by relatively displacing the macro area adjustment optical system that constitutes a part of the zoom magnification moving lens group in the optical axis direction, the operation member is rotated. (A lens driving means that moves the optical system for normal area adjustment in the optical axis/direction in conjunction with and an optical system reversing means for displacing the lens driving means at least a little in the direction, so that when the operating member rotates beyond the normal photographing area, the lens driving means moves the optical system for adjusting the normal area at least by an amount. The technical point is that the optical system reversing means is configured to reverse the normal area adjusting optical system by approximately the same amount.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and the zoom lens optical system includes a positive first lens group, a negative second lens group L! , a positive third lens group, and a positive fourth lens group IJI.

A movable barrel 2 is slidably fitted and supported on a fixed lens barrel 1 to which a lens mount on the camera body side (not shown) can be coupled, and a cam barrel 3 is rotatably supported on the outer periphery of the movable barrel 2. has been done. A first lens barrel 4 holding a first lens group is screwed into one end of the movable barrel 2 via a helicoid screw 5, and a fourth lens barrel 4 holding a fourth lens group is screwed onto the other end of the movable barrel 2. A fourth lens barrel 6 to be held is fixed with a machine screw 7.

Also, a second lens barrel 8 (
! : The third lens barrel 9 holding the third lens group L3 is slidably fitted and supported on the inner periphery of the co-pressure fixed lens barrel 1.

Operation member 10I-j: is screwed and supported by a part of the movable cylinder 2 via a screw (2), and has a straight groove 10A that is long in the optical axis direction.

Indeed, the rotary bottle installed in the first lens barrel 4 is fitted into this straight groove 10A, and the operating member 10 is rotated! l
'& transmitted to the first lens barrel 4.

As shown in FIG. 2, the fixed lens barrel 1 has straight inner grooves IA and 1B extending in the optical axis direction (vertical direction in FIG. 2) and a fourth groove.
It has an escape groove IC extending in the optical axis direction through which the handle 6a of the lens barrel 6 passes.

In addition, as shown in FIG. 3, the movable barrel 2 has two relief grooves that are long in the optical axis direction (vertical direction in FIG. 3) and 2B.
and a linear guide groove 2C extending in the optical axis direction. Furthermore, as shown in FIG. 3, the cam barrel 3 includes a first cam groove 13 for sliding the second lens barrel 8, a second cam groove 14 for sliding the third lens barrel 9, and a second cam groove 14 for sliding the third lens barrel 9. A third cam groove 15 is provided that passes through the linear guide groove 2C of the movable barrel 2 and engages with a fixing pin 16 implanted in the fixed lens barrel 1. Further, the cam cylinder 3 is provided with a sliding groove 3A extending in the circumferential direction (left-right direction in FIG. 4) in which the interlocking pin 17 installed in the movable cylinder 2 is slidably engaged. There is. Furthermore, the first sliding pin 18 that engages with the first cam groove 13 is fixed to the second lens barrel 8 through the escape groove 2A of the movable lens barrel 2 and the linear guide groove IA of the fixed lens barrel. , the second sliding pin 19 that engages with the second cam groove 14 passes through the relief groove 2B of the movable barrel 2 and the linear guide groove IB of the fixed lens barrel 1,
It is fixed to the third lens barrel 9. FIG. 5 is a developed view showing a state in which the fixed barrel 1, movable barrel 2, and cam barrel 3 are combined. Similarly to FIG. Fig. 6 is an enlarged cross-sectional view showing the connecting device section that connects the operating member 10 and the cam cylinder 3, and Fig. 7 shows the state when the distance n and 1 are adjusted to infinity. , is a developed view of the coupling device section, the movement regulating section of the operating member 10, and the cam cylinder 3 shown in FIG. 6. Note that the movement restriction portion is indicated by a two-dot chain line.

As shown in FIGS. 6 and 7, the movable cylinder 2 has a release plate 22 which is fixed to the holding plate side with separate machine screws and has a chevron-shaped slope 22a near the tip slope 20a of the holding plate.
On the other hand, since the operation member 10 is fixedly installed with four machine screws,
As shown in the buttons in FIGS. 1 and 7, on the inner circumferential surface of the button, there is a first rotation restriction plate 24 for regulating the infinite position of the normal photographing area;
A second rotation restriction plate 25 that also serves as rotation restriction for close range in the normal shooting area (hereinafter referred to as "normal close range") and close range in the macro area (hereinafter referred to as "macro close range") and a straight movement restriction plate 2 that regulates the longest focal length position (hereinafter referred to as "telephoto position") of the operating member 10.
6 are fixedly installed by machine screws 27, respectively. The limiting piece 28 that comes into contact with these limiting plates 24, 25 and 26 is a cover tube 29 provided on the outer periphery of the fixed tube 1.
It is fixed to one end with a machine screw 30. The width W of the limiting piece 280 is the first contact surface 25a of the second rotation limiting plate 25.
The distance is slightly narrower than the distance t (see FIG. 7) between the lower end of the straight-travel restriction plate 26 and the upper surface of the straight-travel restriction plate 26.

Furthermore, as shown in FIG. 6, a leaf spring 31 extending in the circumferential direction is fixed to the inner surface of the operating member 10 by a fixing plate 32 and machine screws 33. At the tip of the leaf spring 31, a connector 34 made of plastic having a small coefficient of friction, such as polyacetal, is fixed. When the connector 34 comes into contact with the slope 20a of the presser plate 20, it moves downward as shown by the two-dot chain line in FIG. inserted,
It is configured to engage with this. Oh, leaf spring 31
The connector 34 supported by the connector 34 and the presser plate 2 (13) constitute a connecting means, and the release plate 22 constitutes a release means. Moreover, the automatic coupling device is constituted by the coupling means and the release means.

In FIG. 5, A114A115A is a curved cam portion 13A114A115A115A115A115A115A115A115A115A115A115A115A115A115A115A115A114A115A is a curved cam portion 13 A114A115 of the first cam groove 13, second cam groove 15, and third cam groove 15 formed in the cam barrel 3. , the remaining cam part 1 extending to the right
3B, 114B, and 15B are for distance adjustment in the macro area. In the zoom cam section,
The inclination angle of the first cam groove 13 is greater than the inclination angle of the third cam groove 15, and the inclination angle of the second cam groove 14 is greater than the inclination angle of the third cam groove 15.
The angle of inclination is smaller than that of the In the macro area distance adjusting cam part, the first cam groove 13 has a large inclination angle, and the inclination angle of the second cam groove 14 is zero (0).

As shown in FIG. 7, the third cam groove 15 allows the cam barrel 3 to be displaced downward (to the right in FIG. 1) relative to the fixing pin 16 when the cam barrel 3 rotates to the left. It is configured as follows.

The lens drive means is composed of a helicoid screw 5 for feeding out the first lens barrel 4 and a rotation pin 12 for transmitting the rotation of the operating member 10, and a macroscopic mechanism for the third cam groove 15 provided in the cam barrel 3 constitutes a lens driving means. The first lens group (normal area adjustment optical system) LI is returned using the movable cylinder 2 that supports the lens driving means including the interlocking pin 17 and the helicoid screw 5 that engage with the area cam groove 15B and the sliding groove 3A. An optical system reversing means is configured.

Next, the operation of the embodiment configured as described above will be explained.

1 and 7, the operating member 10 has the shortest focal length (
Move along the optical axis to the wide-angle) position (move to the right in Figure 1 and downward in Figure 7) L! , 1. Furthermore, at infinity (ω
) indicates the state when the distance is adjusted to the position. In this state, the side surface of the first rotation limiting plate 24 is in contact with a limiting piece 28 fixed to the cover tube 29, as shown in FIG. Further, since the connector 34 of the automatic coupling device and the sloped end 20a of the presser plate 20 are located apart from each other, the rotation of the operating member 10 is not transmitted to the cam cylinder 3.

When the operating member 1 (13) is slid from the position shown in Fig. 1 to the left (upward in Fig. 7) along the optical axis, the movable cylinder 2 connected via the screw 11 moves to the left as one Moving. In this case, the fixed pin 16 implanted in the fixed barrel 1 is connected to the movable barrel 2.
Since it is engaged with the straight guide groove 2C (see Fig. 5),
The movable barrel 2 moves straight along the straight guide groove 2C without rotating around the optical axis. As a result, the first lens barrel 4 and the fourth lens barrel 6, which are coupled to the movable barrel 2, move together to the left in FIG. 1 along the optical axis. Therefore, the first lens group L4 and the fourth lens group L4 simultaneously move by the same amount to the left along the optical axis.

When the movable tube 2 moves to the left in FIG. 1 together with the operating member 1, the interlocking pin 17 implanted in the movable tube 2 moves upward in FIG. 5 (to the left in FIG. 1). The cam cylinder 3 is moved upward via the sliding groove 3Ae.

On the other hand, the fixing pin 1 that engages with the third cam groove 15 of the cam cylinder 3
6 is fixed to the fixed lens barrel 1 and is immovable, so the cam barrel 3
moves upward together with the movable cylinder 2, and at the same time the third cam groove 1
5 according to the cam shape of the zoom magnification changing cam part 15A.
It rotates to the left in Figures and Figure 7. Therefore, both the first cam groove 13 and the second cam groove 14 move obliquely to the left in FIG. 5 according to the inclination angle of the zoom magnification changing cam portion 15A of the third cam groove 15.

In this case, as is clear from FIG. 5, the inclination angle of the zoom magnification cam portion 13A of the first cam groove 13 with respect to the rotational direction (left side) of the cam barrel 3 is the same as that of the zoom magnification cam portion of the third cam groove 15. The inclination angle of the zoom magnification changing cam portion 14A of the second cam groove 14 is smaller than the inclination angle of the zoom magnification changing cam portion 15A of the third cam groove 15. Therefore, according to the difference in the respective inclination angles, the first sliding pin 18 that engages with the first cam groove 13 moves downward (to the right in FIG. 1) along the straight guide groove IA, and at the same time, The second sliding pin 19 that engages with the second cam groove 14 moves upward (leftward in FIG. 1) along the straight guide groove IB.

Therefore, when the operating member 1 (13) is slid to the left in FIG. 1, the first lens group...! :The fourth lens group moves to the left together with the melting operation member 10, and at the same time, the second lens group moves to the right, and the third lens group moves to the left, and the zoom lens The focal length gradually changes from the shortest focal length to the longer focal length. As a result, the operation member 10
The zoom magnification is changed according to the movement of . If the operating member 10 still moves to the left in FIG. 1 and reaches the telephoto position,
The straight movement limiting plate 26 fixed to the operating member 10 moves upward in FIG. 7, and as shown in FIG. 8, comes into contact with the limiting arm 28 of the cover cylinder 29, thereby preventing its movement. At this time, the first sliding pin 18, the second sliding pin 19, and the fixed pin 15 are connected to the bent portion 1 of the first cam groove, respectively.
3a1im2 The bent portion 14a1 of the cam groove 14 reaches the bent portion 15a of the third cam groove 15, and the zoom lens optical system
~The combined focal length of TJL is maximum.

Next, distance adjustment will be explained in detail. First, distance adjustment in the normal shooting area will be described.

When the operating member 1 (13) is rotated around the optical axis within the range of movement along the optical axis, excluding the telephoto position of the operating member 10, the rotation will change to the first position on the infinity side as shown in FIG. The rotation is restricted by the rotation restriction plate 24 coming into contact with the restriction arm 28 of the cover cylinder 29 . Further, when the operating member 1 (13) is rotated to the close distance side, the second rotation restriction plate 25 moves to the left in FIG. 7, and the first contact surface 25a of the second rotation restriction plate 25
By contacting the limiting arm 28, its rotation is prevented.

Furthermore, when the operating member 10 rotates, the first lens barrel 4 rotates about the optical axis via the rotation pin 1.2 that fits into the linear groove 10A of the operating member 10.

Due to this rotation, the first lens group together with the first lens barrel 4 rotates and moves in the optical axis direction (moves to the left in FIG. 1) in accordance with the lead of the helicoid screw 5, and the first lens group moves in the direction of the optical axis (moves to the left in FIG. 1) in the normal shooting area. Distance adjustments are made.

Next, distance adjustment during photography in a macro area (hereinafter referred to as "macro photography") will be described.

In the above example of a real gun, macro photography becomes possible when the operating member 1 is extended and placed at the telephoto position and then further rotated beyond the normal close range position.

FIG. 9 shows a state in which the operating member 1 (13) has been extended to the telephoto position and further rotated to the normal close range position.

As shown in FIG. 7, the length of the first contact surface 25a of the second rotation restriction plate 25 is shorter than the length of the first rotation restriction plate 24;
The width W of the limiting arm 28 is configured to be slightly narrower than the interval t. Therefore, when the operating member 10 is at a position on the optical axis other than the telephoto position, the first contact surface 25a of the second rotation limiting plate 25 contacts the limiting arm 28, so that the operating member 1 is normally placed at a close range position. It is impossible to rotate beyond.

However, as shown in FIG.
8, that is, when the operating member 10 is extended to the telephoto position, the limit at the close range position is usually lacking, so the first contact surface 25a shown in FIG. It can be displaced to the left without contact.

Therefore, the operating member 10 rotates beyond the normal close range position (J7) only in the telephoto position, and as shown in FIG. When the touching macro close range position is reached, the rotation is stopped.

On the other hand, the operating member 10 normally rotates at close range,
As shown in FIG. 9, the second rotation limiting member 25 has a limiting arm 28
When reaching a position close to , the connector 34 fixed to the tip of the plate spring 31 provided on the operating member 10 approaches the slope 20a of the holding plate 20, as shown in FIG. Also,
When the operating member 10 is extended to the telephoto position, the cam cylinder 3
rotates according to the cam shape of the third cam groove 15, and the cam cylinder 3
The retaining groove 35 provided in is placed between the slope 20a of the holding plate 20 and the chevron-shaped slope 22a of the release plate 22.

When the operating member 10 moves beyond the normal close range position and further toward the macro close range position (in the direction of the arrow in FIG. 6), the connector 34 is attached to the slope 20a of the presser plate 20 fixed to the movable cylinder 2. The end faces of the connector 34 are in contact with the leaf spring 31.
It is pushed down along the slope 20a in FIG. 6 against the urging force of , and is fitted into the engagement groove 35 of the cam cylinder 3 as shown by the two-dot chain line. Since the cam cylinder 3 and the operating member 10 are connected to each other by the engagement between the connector 34 and the engagement groove 35, the second rotary contact surface 25b (see FIG. 9) of the second rotation limiting plate 25 is until it comes into contact with the restriction piece 28,
Rotate to the left. At this time, the press plate 20 covers the top of the connector 34 and prevents the connector 34 from coming off from the engagement groove 35. In this macro region, the third contact surface 25c of the second rotation limiting plate 25 is placed in contact with the limiting piece 28 as shown in FIG. 4, so that the movement of the operating member 10 in the optical axis direction is prevented. It becomes impossible. Therefore, in the case of macro photography, zoom magnification cannot be changed.

In the second rotation, the second contact surface 25b of the limiting plate 25 is the limiting piece 28
Operation member 1 (13) to the macro close range position where it comes into contact with
When the cam cylinder 3 rotates, the cam cylinder 3 rotates together with the operating member 10.
The cam grooves 13 to 15 rotate leftward from the position shown in FIG. 9 to the position shown in FIG. 10.

Therefore, the second lens group moves largely relative to the other lens groups in a direction opposite to the movement direction for zooming, according to the cam shape 1 j9 ) of the first cam groove 13.

With this, it is possible to perform macro photography by adjusting the distance to a close range in an extremely close macro area.

When switching the imaging area from the macro area to the normal imaging area, the operating member 1 (13) is rotated in the direction of the infinite position of the normal imaging area (in the direction opposite to the arrow in FIG. 6). When the connector 34 reaches the vicinity of the tip slope 20a of the presser plate 20, as shown by the two-dot chain line in FIG.
comes into contact with the chevron-shaped slope 22a of the release plate 22, rises along the chevron-shaped slope 22a, and separates from the engagement groove 35. At this time, the connector 34 further rises due to the restoring force of the leaf spring 31 and returns to the position shown by the solid line. On the other hand, the second
The third contact surface 25c of the rotation limiting plate 25 separates from the limiting piece 28. Therefore, distance adjustment can be switched from the macro area to the normal shooting area, and zooming can also be changed.

As described above, when the operating member 10 and the cam cylinder 3 are connected via the connector 34 and the engagement groove 35 (20), the connector 34 slides on the slope at the tip of the presser plate 20, It is pressed against the retaining groove 35 by the lower surface. Also, cam tube 3
When the connection between the and the operating member 10 is released, the connector 34 separates from the engagement groove 35.
It is pressed against the chevron-shaped slope 22a of No. 2. Therefore, when connecting and releasing the connection, especially when releasing the connection, the connector 34 and the engagement groove 35
The amount of friction that occurs between the two has a large effect on the switching tone when switching the imaging area. In the above embodiment, in order to make the switching smooth, polyacetal, which has a small coefficient of friction, is used as the material for the connector 34, and is configured to minimize frictional resistance.

FIG. 11 is an optical system movement diagram showing the movement of each lens group in the embodiment of FIG. 1. Point A in Fig. 7 is the point at infinity (
ω) position, point B is the normal close distance position of the first lens group in the wide-angle state, point C is the infinity (Q5) position of the first lens group in the telephoto (longest focal length) state, and point D is the The first lens group L10 is normally at a close distance position in a telephoto state.

The first lens group moves within the range surrounded by points A, B, C, and D by zooming and adjusting the distance in the normal shooting area. Distance adjustment in the normal photographing area is performed by extending the first lens group L1 according to the lead of the helicoid screw 5, but when entering the macro area θ, as described above, the operating member 10 and the cam barrel 3 are linked. Distance adjustment is made in the macro area. In this case, the first
As shown in FIG. 10, the macro area distance adjusting cam portion 15B from the bent portion 15a of the third cam groove 15 is inclined upward to the right, so that the fixing pin 16 is aligned with the chain double-dashed line in FIG. When the cam barrel 3 is rotated to the left so as to reach the macro close range position shown by the solid line from the position of the bent portion 15a, the cam barrel 3
is the macro area distance adjusting cam portion 15 of the third cam groove 15
According to the inclination of B, it rotates downward (first
(to the right in the figure) by an amount of movement X.

This downward movement of the cam cylinder 3 causes the movable cylinder 2 to move by an amount X to the right in FIG. 1 via the sliding groove 4A and the interlocking pin 17. Therefore, the fourth lens group L4 moves to the right by X along with the movable barrel 2, as shown in FIG.

On the other hand, the amount of movement of the first lens group is the helicoid screw 5.
It is the sum of the amount of movement y from the normal close-range positioning point and the displacement tx of the cam cylinder 3. Therefore, if the macro area distance adjusting cam portion 15B of the third cam groove 15 is tilted so that y≦X, the first lens group can move forward from the close distance position point in the telephoto state. There is no. In the embodiment shown in FIG. 1, the third cam groove 15 is used for adjusting the distance in the macro area so that the first lens group L1 does not move from the normal close distance position in the telephoto state when adjusting the distance in the macro area. The cam portion 15B is tilted in the opposite direction to the zoom magnification cam portion 15A, so that the amount of movement X of the first lens L1 and the amount y of delivery by the helicoid screw 5 are offset.

In this case, as shown in FIG. 11, the amount y of the first lens group extended by the helicoid screw 5 and the amount X returned by the third cam groove 15 are in the relationship x=y. , is returned from point 5 to point E. If the first lens group L
1 is not returned by the third cam groove 15 (for example, when the inclination of the macro-area distance adjusting cam part 15B of the third cam groove 15 is zero), the curvature of field is positive at the periphery of the lens image plane. The direction changes greatly, making it difficult to obtain a sharp image. Therefore, in FIG. 11, the macro area distance adjusting cam portion 15 of the third cam groove 15 is adjusted so that y≦X.
By forming B, it is possible to compensate for aberrations in the optical system, especially curvature of field, which are caused by the first lens group L1 being extended forward beyond its normal close-range position in the telephoto state.

Further, the second lens group L1 is largely displaced to the left by the macro area distance adjusting cam portion 13B (see FIG. 5) of the first cam groove 13, and reaches point G as shown by the dotted line in FIG.
', but is moved back by X by the macro area distance adjusting cam portion 15BK of the third cam groove 15, and moves to point H shown by the solid line. Further, the third lens group moves to the right by X along with the fourth lens group L4 as shown by the solid line, and the third lens group moves to one point and the fourth lens group moves to the right by X.
Reach the point. As mentioned above, when adjusting the distance in the macro area, the first lens group remains stationary at the close-up position in the telephoto state, and the second lens group moves to the left.
By simultaneously displacing the third lens group and the fourth lens group L4 to the right, distance adjustment in the macro area can be performed to extremely close positions without worsening the aberrations of the optical system.

〔Effect of the invention〕

As described above, according to the present invention, zooming is performed by moving a single operating member in a straight line in the direction of the optical axis, and by rotation around the optical axis, distance adjustment in the normal shooting area is followed by adjustment in the macro area. Since the lens is configured so that the distance can be adjusted and the first lens group (normal area adjustment optical system) does not move forward when adjusting the distance in the macro area, zooming in the normal shooting area is possible. Not only can magnification change and distance adjustment be performed simultaneously, but also distance adjustment can be performed continuously from the normal photographing area to the macro area, and in this case, field curvature in the peripheral area of the lens image plane can be well corrected. Therefore, it has excellent operability and can provide an extremely clear image up to the periphery of the screen.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIGS. 2 to 4 are developed views of the lens barrel section of the embodiment of FIG. 1, FIG. 2 is a fixed lens barrel, and FIG. FIG. 4 shows the movable cylinder, and FIG. 4 shows the cam cylinder. FIG. 5 is a developed view showing the joints shown in FIGS. 2 to 4 superimposed, and FIG. 6 shows the connection of the embodiment shown in FIG. FIGS. 7 to 10 are expanded views of the coupling device, operating member regulating portion, and cam cylinder of the embodiment shown in FIG. 1, and the focal length and distance adjustment position are as shown in FIG. 7, respectively. 8 shows the state adjusted to wide-angle and infinity, Fig. 8 shows the state adjusted to telephoto and infinity, Fig. 9 shows the state adjusted to telephoto and normal close range, Fig. 10 shows the state adjusted to telephoto and macro close range, and Fig. 11 shows the state adjusted to telephoto and macro close range. FIG. 3 is an optical system layout diagram showing a moving state of the optical system in the example. [Description of symbols of main parts] 1...Fixed lens barrel 3...Cam barrel 10...Operation member 13...First cam groove 14...Second Cam groove 15...Third cam groove

Claims (2)

[Claims] (1) By rotating the operating member around the optical axis, the optical system for adjusting the normal area is moved in the optical axis direction to adjust the distance in the normal shooting area, and then by rotating beyond the normal shooting area, the zoom magnification can be changed. In a zoom lens that allows distance adjustment in a nearby macro area by relatively displacing a macro area adjustment optical system that constitutes a part of a movable lens group in the optical axis direction, a lens driving means for moving the normal area adjusting optical system in the optical axis direction; and a lens driving means for moving the lens in the direction opposite to the direction in which the lens is moved by the lens driving means in response to rotation of the operating member beyond the normal photographing area. and an optical system reversing means for displacing the driving means, the amount being at least approximately equal to the amount by which the lens driving means moves the normal area adjusting optical system when the operating member rotates beyond the normal imaging area. A distance adjusting device for a zoom lens, characterized in that the optical system reversing means is configured to reverse the normal area adjusting optical system by a certain amount. (2) The lens driving means includes a rotating pin (12) that transmits the rotation of the operating member (10) to the first lens barrel (4) holding the normal area adjustment optical system (L_1), and the first
The optical system reversing means includes a helicoid screw (5) formed in the lens barrel (4), and rotates by a zooming operation to move the zoom magnification changing movable lens group (L_1 to L_4).
), and further rotates in conjunction with the rotation of the operating member (10) beyond the normal photographing area.
a cam groove (15B) that moves the cam tube in the optical axis direction; The zoom lens distance adjusting device according to claim 1, further comprising a movable barrel (2) that supports the first lens barrel.