JPS5841482B2 - Zoom lens barrel with macro mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a zoom lens barrel equipped with a macro mechanism.

As shown in FIG. 1, the optical system of a zoom lens capable of macro photography includes at least two movable lens groups L1. Among L2, movable lens group L2
consists of a lens group 12 with positive refractive power and a lens group 11 with negative refractive power, and both the positive and negative lens groups 12-11 are mechanically separated as shown in FIG. 1C only during macro photography. Furthermore, a zoom lens optical system that enables macro photography by continuously increasing the relative distance between the axes of both lens groups 12 and 11 is already known (Japanese Patent Application Laid-Open No. 49-42361).

Therefore, the present applicant previously filed an application for a lens barrel as shown in FIG. 8 as a lens barrel using this type of zoom lens optical system (Utility Model Application No. 49145629).

That is, the lens barrel shown in FIG. 8 has a movable lens group L1 consisting of both positive and negative lens groups 12 and 11, and separate holding frames 22 and 23 for holding both the positive and negative lens groups 12 and el, respectively.
At the same time, guide pins 22a and 23a are installed in the holding frames 22 and 23#, and the fixed lens barrel 2
4 and the zooming operation ring 25 have the guide pin 2
The cam grooves 26 and 27 and the linear guide grooves 2B and 29, into which the cam grooves 2a and 23a fit and engage, respectively, are provided, and the cam groove 26
, 27 are formed parallel to each other and have the same shape, and when the zooming operation ring 25 is rotated, both the positive and negative lens groups 12 and 27 are formed parallel to each other and have the same shape.
11 are configured to move together while maintaining a predetermined relative position with the other movable lens group L2, thereby enabling normal zooming operations.

On the other hand, the zooming operation ring 25 is provided with an escape groove 30 extending in the circumferential direction, and when performing macro photography, the zooming operation ring 25 is slid in the loss direction and the guide pin is inserted into the escape groove 30. 22a, the rotational force of the zooming operation ring 25 is not transmitted to the guide pin 22a but only to the guide pin 23a, and the relative distance between the axes of both the positive and negative lens groups 12 and e is determined by the rotation force of the zooming operation ring 25. 25
The rotation of the lens gradually increases the size of the lens, making macro photography possible.

However, the above lens barrel has a configuration in which only one of the positive and negative lens groups that make up the negative movable lens group is stopped during macro photography, and the zooming operation ring cannot be moved in a direction different from the zooming direction. By moving the zooming operation ring, the relief groove formed on the inner circumferential surface of the zooming operation ring is positioned on the guide pin of one lens holding frame. In a lens barrel of a so-called ring-type zoom lens, which is configured to perform focusing by a rotating movement and focusing by a rotational movement of the operation ring, the moving direction for moving and operating the relief groove is adopted. There was a drawback that it could not be implemented because it could not be done.

In addition, in the above lens barrel, an extra holding frame must be provided for dividing the - movable lens group into both positive and negative lens groups, and this holding frame can be fixed to the fixed lens barrel by external operation of the operation ring. In order to make the inner part so that it can slide independently and to prevent the lens group it holds from tilting when sliding, it has to have a long shape in the optical axis direction, which increases the size of the lens barrel itself. There were drawbacks.

Furthermore, in the above lens barrel, it is necessary to drill an extra cam groove in the fixed lens barrel by dividing the negative movable lens group into both positive and negative lens groups. In order for the divided positive and negative lens groups to be movable as a unit, they must be formed in exactly the same shape as the other cam groove and in parallel to each other, which requires a lot of manufacturing cost. There were inconveniences such as causing uploads.

The present invention has been made in view of the above-mentioned points, and its purpose is to perform a zooming operation by rotating an operating ring, or to perform a zooming operation by sliding an operating ring in the optical axis direction. Any type of zoom lens barrel, such as a lens barrel configured to perform focusing by movement and rotation of the operating ring, can be implemented without any problems and its shape is Compared to conventional zoom lens barrels, it does not need to be particularly large, and compared to conventional zoom lens barrels, there is no need to drill extra cam grooves, making the structure extremely simple and inexpensive. An object of the present invention is to provide a lens barrel for a zoom lens equipped with a macro mechanism that can be manufactured.

The configuration of the present invention will be explained below with reference to the accompanying drawings.

FIG. 2 shows an embodiment of the present invention, in which 1 is a fixed lens barrel, and as is well known, a focusing lens system F is attached to the tip of the fixed lens barrel.
A master lens system M is fixed to the rear end of the master lens system M so as to be able to move forward and backward, and a penetrating cam groove 2 is provided on the peripheral side of the lens barrel as shown in FIG. 3 is drilled.

Reference numeral 4 denotes an operating ring for performing a zooming operation, which is rotatably provided around the circumferential side of the fixed lens barrel 1, and has a linear guide groove 5°6 extending in the optical axis direction on its inner circumferential surface. ing.

7 is a first movable frame body containing a first movable lens group L1 constituting a variable power lens system;
and the master lens system M in a slidable manner.

A guide pin 7a is installed in this first movable frame 7, and this guide pin 7a passes through the cam groove 3 of the fixed lens barrel 1, and is further inserted into the linear guide groove 6 of the operation ring 4.
The first movable frame 7 is fitted into the optical axis and moved in the optical axis direction in conjunction with the rotational movement of the operating ring 4.

8 is a second movable frame body, which is a second movable lens group L disposed between the first movable lens group L1 and the master lens system M;
It includes a negative lens group 11 of the two lenses.

A guide pin 8a is installed in this second movable frame 8, and this guide pin 8a passes through the cam groove 2 of the fixed lens barrel 1 and is further attached to the inner peripheral surface of the operation ring 4. It is formed so as to fit into a linear guide groove 5 provided and move the second movable frame 8 in the optical axis direction in conjunction with the rotational movement of the operating ring 4.

Further, an annular protrusion 8b is provided on the surface of the second movable frame 8 on the master lens side.
has penetrating notch grooves 8c, 8c facing each other with the optical axis as the center, as shown in FIG. 4, on its circumferential side.

Reference numeral 9 denotes a substantially U-shaped spring provided around the circumferential side of the protruding portion 8b of the second movable frame 8, and a portion of the spring 9 protrudes from the notched grooves 8c, 8c toward the optical axis side.

Reference numeral 10 denotes a driven frame body containing the positive lens group 12 of the second movable lens group L2 constituting the variable magnification lens system, and a driven frame body that is slidably mounted between the lens group 11 of the above number and the master lens system M. It is fitted.

Further, on the focusing lens side of the driven frame 10, an annular protrusion that can be fitted into the protrusion 8b of the second movement frame is provided, and furthermore, the tip (which has a substantially triangular cross section) is provided. A locking portion 10a is provided.

Therefore, when the driven frame 10 is in close contact with the second moving frame 8 shown in FIG.
c.

It is configured to be clamped by a spring 91 protruding from the second movable frame 8c and move integrally with the second movable frame 8, and when clamped with a strong force, the spring 9
It is constructed so that it can overcome the force exerted by the clamping members and become stationary, and be separated from the second movable frame 8.

Reference numeral 11 denotes a switching operation ring for switching from normal zoom photography to macro photography, and as shown in FIG.
A switching index for switching from zoom photography to macro photography is provided, and is provided on the circumferential side of the fixed lens barrel 1 so as to be rotatable by a fixed amount.

Reference numeral 12 denotes a locking lever pivotally mounted on the switching operation ring 11. The locking lever 12 is always biased in the radial direction from the optical axis by a spring (not shown). It can be pushed toward the optical axis side using the operating button 13.

When the locking lever 12 is pushed toward the optical axis against the biasing force, the locking lever 12 passes through the notch 4a provided in the operating ring 4 and extends downward from the operating ring 4. a bent first locking end 12a formed to be located in the direction of the optical axis; and a second locking end 12a formed to be located within the sliding trajectory of the driven frame 10 in the optical axis direction only during the pushing movement. A mountain end 12b is provided.

Since the present invention is configured as described above, when performing a normal zooming operation, for example, when changing magnification from a long focus state to a short focus state shown in FIG. 2, first, the operating ring 4 1 in Figure 2 and rotate it toward you.

When the operation ring 4 rotates, the guide pins 7a and 8a are guided within the cam grooves 3 and 2 formed in the fixed lens barrel 1, respectively, by the linear guide grooves 6 and 5 provided on the inner peripheral surface thereof. 1st
Both the movable frame 7 and the second movable frame 8 move toward the focusing lens.

When the second movable frame 8 moves, the driven frame 10 (this is located in the optical axis direction from the notch grooves 8e, 8e of the second movable frame on the focus side of the locking portion 10a formed with a substantially triangular cross section) Since the spring 9 protruding in the direction is located, the movement of the second ijT moving frame 8 (the frayed spring 9 contacts the locking portion 10a and moves the driven frame 10 in the same direction).

Therefore, at this time, the second movable lens group ■7□ constituting the variable magnification system lens group, both the positive and negative lens groups 12 and 11, are moved to the focusing l/waste side to the short focus position of variable magnification. is set to

Next, to explain in detail the operation when performing macro photography, from the state of the longest focus position in Fig. 2, first, press the operation button 13.
While pressing , the switching operation ring 11 is rotated clockwise to set the index in FIG. 5 from the zoom position to the macro position.

At this time, by pressing the operation button 13, the first locking end 12a of the locking lever 12 passes through the notch 4a of the operation ring 4.
It is located below the operation ring 4, and the second locking end 12b passes through the fixed lens barrel 1 and is located within the sliding trajectory of the driven frame 10 in the optical axis direction (see FIG. 6a).

Then, following the pressing of the operation button 13, the switching operation ring 11 is rotated (thereby, the locking lever 12 moves together and the first locking end 12a is cut off from the inner peripheral surface of the operation ring 4). Notch 4a
Therefore, even if the push button 13 is subsequently released, the locking lever 12 is prevented from returning to its original position by the inner peripheral surface of the control button 1'F44. 2 section JL end 1
2b is maintained within the sliding locus of the driven frame 10 in the optical axis direction.

Next, when the operating ring 4 is operated to the short focus side, the same operation as described above is performed, and the first moving frame 7 and the second movable frame 8
is moved to the focusing lens side.

When the second movable frame 8 moves, the aforementioned spring 9 engages with the locking portion 10a (thereby, the driven frame 10 tries to follow this, but at this time, the sliding of the driven frame 10 As described above, the second locking end 12 of the locking lever 12 is located within the movement trajectory.
b is located, the driven frame 10 is prevented from moving toward the focusing lens, and the second locking end 12b
It is clamped at the position where it touches.

When the driven frame body 10 is clamped, the spring 9 provided on the second movable frame body 8 moves to the second movable frame body 8 as shown in FIG.
As the movable frame 8 moves, the locking portion 10a, which has a substantially triangular cross section, is gradually expanded by the sloped surface on the master lens side, and finally extends beyond the top of the locking portion 10a, as shown in FIG. Since the relationship is severed, the second movable frame 8 moves independently away from the driven frame 10, and the negative lens group 11 and the positive lens group 12 forming the second movable lens group L2.
Gradually increase the distance between the shafts.

As the distance between the axes increases, the distance to the subject becomes closer and the imaging magnification increases.
Macro photography becomes possible.

Further, in order to return to the normal zooming shooting state from macro photography, first, the operation ring 4 is rotated toward the long focus side.

By this operation, both the first movable frame 7 and the second movable frame 8, which are interlocked with the operation ring 4, are moved toward the master lens side.

When this movement is completed, the second movable frame 8 moves to the protrusion 8
The driven frame 10 is moved again via the spring 9 provided at b.
be integrated with.

That is, just before reaching the movement completion position, the spring 9 engages with the locking portion 10a of the driven frame 10 on the inclined surface on the focusing lens side, as shown in FIG. 6C, and from this state, the second movable frame As the body 8 is moved, the spring 9 is gradually expanded by the inclined surface, and finally reaches beyond the top and is located on the opposite inclined surface, as shown in FIG.

Then, the operation ring 4 is rotated to the final position, and when the spring 9 reaches the position shown in FIG. 6a, the switching operation ring 11 is rotated to switch the index from the macro position to the zoom position.

As a result, the lens barrel returns to the state shown in FIG. 2 again, and the zooming operation force S'oJ becomes available.

FIG. 7 shows another embodiment of the present invention, in which a zooming operation is performed by sliding an operating ring in the optical axis direction, and focusing is performed by rotating the operating ring. The present invention is applied to a so-called ring-type zoom lens barrel.

In the figures, members having the same functions as those in the embodiment described above are given the same reference numerals, and redundant explanations will be omitted.

Reference numeral 14 denotes an operation ring for performing a zooming operation by sliding movement in the optical axis direction, and the operation ring 14 has a linear guide groove 15 provided on its inner peripheral surface and a focusing lens system F.
The focusing lens system F is formed to move forward and backward in conjunction with the rotational movement of the guide pin 16 installed in the holding member.

Reference numeral 17 denotes a control member that is slidable only in the optical axis direction by a linear guide groove provided on the inner peripheral surface and a guide pin (not shown) installed in the fixed lens barrel 1. The control member 17 has an annular marking portion 17a that engages with the operation ring 14.
Therefore, when the operation ring 14 rotates (this does not rotate from the side, but only when the operation ring 14 slides in the optical axis direction), it is formed to follow this movement.

The control member 17 includes the first movable frame 7 that protrudes through the cam groove 3°2 of the fixed lens barrel 1 as described above.
Guide cam grooves 18 and 19 are bored into which the guide pins 7a and 8b of the second movable frame 8 fit and engage, respectively.
When the control member 17 slides in the axial direction, the first movement frame 7
and is formed to move the second movable frame 8 in the axial direction.

Reference numeral 20 denotes a lock lever for preventing erroneous operation by preventing switching from zooming photography to macro photography when the variable magnification lens system is in a state other than the longest focal position. It is provided on the circumferential surface and is formed by a plate spring member, and is constantly given a biasing force in the radial direction from the optical axis.

Further, this lock lever 20 is formed so as to penetrate through the fixed lens barrel 1 and protrude into the sliding locus of the operating ring 14, and to be pressed only when the operating ring 14 is set to the longest focal point side. It has a release portion 20a and a locking end 20b formed to be located within the rotation locus of the first locking end 12a when the locking lever 12 is pushed.

Reference numeral 21 denotes a notch portion that allows the locking lever 12 to be lowered when the operation button 13 is pressed, and the notch portion 21 corresponds to the notch 4a formed in the operation ring 4 in the above-mentioned first embodiment. It is provided on the fixed lens barrel 1.

Next, the operation of the above configuration will be described.

When performing a normal zooming operation, when the operation ring 14 is slid in the optical axis direction, the control member 1
7 follows this.

When the control member 17 moves, the guide pins 7a and 8a that fit into the guide cam grooves 18 and 19 of the control member 17 are guided in the cam grooves 3 and 2 formed in the fixed lens barrel 1. The first movable frame 7 and the second movable frame 8 move on the optical axis to change the magnification.

At this time, as the second movable frame 8 moves, the driven frame 10 moves all the way, and both the positive and negative lens groups 12 and 11 held respectively are integrated into the second movable lens. Group L2
The configuration is as detailed in the first embodiment above.

Further, when performing macro photography from a normal zooming photography state, first, the operating ring 14 is set to the longest focus position to bring it into the state shown in FIG.

Next, press the operation button 13 to release the second locking end 1 of the locking lever.
2b within the sliding trajectory of the driven frame 10, and then the first locking end 12a of the locking lever is inserted into the notch on the inner surface of the fixed lens barrel 1 to rotate the switching operation ring 11. 21, and maintain the pushing position of the locking lever 12.

Then, in the above-mentioned state in which the second locking end 12b of the locking lever 12 is located within the sliding trajectory of the driven frame 10, when the variable power lens system is moved from the long focal position to the short focal position l. ,
Through the operation described in detail in the first embodiment, only the negative lens group e1 of the second movable lens group L2 moves, and as a result, the subject distance becomes continuously shorter and the photographing magnification increases. This makes macro photography possible.

In addition, when the operation ring 14 is set to a position other than the longest focal point position, the lock lever 20 is released from the pressure of the release part 20a, so the lock lever 20 is moved in the radial direction from the optical axis compared to the state shown in FIG. in a state.

Therefore, when the switching operation to macro photography is performed in this state, when the operation button 13 is pressed, the locking end 20b of the locking lever 20 will move along the rotational trajectory of the first locking end 12a of the locking lever 12. Because it is located within the switching operation ring 11
cannot be rotated, making it impossible to switch to macro photography.

This allows the photographer to easily recognize that the variable magnification lens system is not set at the longest focal position, thereby completely preventing erroneous operations.

In the above embodiment, the movable lens group constituting the variable magnification lens system is divided into both positive and negative lens groups, and in a structure in which these are integrated during normal zooming operation, each lens holding Although only the configuration using the spring provided on the frame and the approximately triangular engaging portion has been explained,
The present invention is not limited to this, and can be implemented even if the holding frames of both the positive and negative lens groups are integrated by the attraction force of a magnet or the like.

In addition, in the above embodiment, only a configuration in which the movable lens group located closest to the master lens among the movable lens groups constituting the variable power lens system is divided into both positive and negative lens groups has been described, but the present invention The present invention is not limited to this, and can be implemented even if the movable lens group located closest to the focusing lens is divided into both positive and negative lens groups, and it goes without saying that it is based on the same technical idea as the present invention. stomach.

As described above, the present invention provides a zoom lens that enables macro photography by dividing the movable lens group constituting a variable magnification lens system into both positive and negative lens groups and increasing the relative distance between the axes. As for the lens barrel, during macro photography, the movable lens group is held divided into positive and negative lens groups, and the structure that stops the movement of one of the lens groups is simply to stop the movement of one of the lens groups within the sliding trajectory of one holding frame. The zooming operation is performed by the M movement of the operating ring, or Macro photography is possible with any type of zoom lens barrel, including those that perform sliding motion in the optical axis direction or those that perform sliding motion in the optical axis direction. An extremely versatile lens barrel can be provided.

In addition, in the present invention, as a structure for moving the movable lens group - which is held separately into both positive and negative lens groups, as one unit during zooming operation, both lens holding frames are engaged between both lens holding frames. Since we adopted a structure in which a holding means is provided that holds both frames together when they are in this state and releases the holding when a force is applied to both holding frames to relatively separate them, only one holding frame can be held. The other holding frame moves in close contact with the operating ring on the outside of the lens barrel, so there is no need to move it independently. Because it is integrated with the holding frame, there is no risk of it tilting, and it can be formed extremely simple and thin, making it possible to take macro photography without having to make it particularly large compared to a normal zoom lens barrel. can be made possible.

Furthermore, as described above, in the present invention, for the movable lens group divided into both positive and negative lens groups, only one lens holding frame is required to move the movable lens group as one body during normal zooming operations. can be moved in conjunction with external operation, and the other lens holding frame can be configured to follow this, so unlike the conventional example, the other lens holding frame can be moved in conjunction with external operation, so it is not fixed. There is no need to worry about adding an extra cam groove on the lens barrel side, and therefore, compared to conventional configurations, it is extremely simple and inexpensive to manufacture, and it is also a zoom lens barrel that enables macro photography. However, compared to ordinary zoom lens barrels, it has excellent features and effects, such as being able to be manufactured at a relatively low cost.

[Brief explanation of the drawing]

Figures 1 a, b, and c are cross-sectional views showing the optical system used in the present invention, where a is a short focus state, l] is a long focus state, and C is a macro photography state. FIG. 3 is a half-cut sectional view of the main part showing one embodiment of the same, FIG. 3 is a developed view of the main part of the same embodiment, and
The figure shows only a cross-sectional view of the N- section of the above embodiment, Fig. 5 is a plan view showing the external appearance of the above embodiment, and Figs. 6 a, b, and c show the operating state of the above embodiment. FIG. 7 is an enlarged sectional view of the main part, FIG. 7 is a half-cut sectional view of the main part showing another embodiment of the present invention, and FIG. 8 is a partially cutaway view showing a conventional example of the invention. 8... First holding frame body, 1o... Second holding frame body, 9° 10a... Holding means, 11... Fixed lens barrel portion, 12
12b, 13... Blocking means, Ll... First movable lens group, L2... Second movable lens group, 'l... Negative lens group, 12... Positive lens group.

Claims (1)

[Claims] 1 A first movable lens group, a second movable lens group consisting of a positive lens group having positive refractive power and a negative lens group having negative refractive power.
a movable lens group, the first and second movable lenses are moved on the optical axis while changing the distance between them to perform zooming, and the relative axes of both the positive and negative lens groups of the second movable lens group A first holding frame that moves on the optical axis while changing the distance from the first movable lens group by an external manual zooming operation in a zoom lens that enables macro photography by increasing the distance between the lenses. and a second holding frame movable on the same optical axis to individually hold the lens groups divided into positive and negative lenses, and both holding frames are provided between the first holding frame and the second holding frame. A holding means is provided that holds both bodies together when they are engaged, and releases the holding when a force is applied between both holding frames in a direction to relatively separate them. A blocking means for blocking the movement of the second holding frame body by external operation is provided on the fixed lens barrel portion whose movement is blocked, and movement of the second holding frame body is prevented by operating the blocking means during macro photography. The invention is characterized in that it is configured such that only the first holding frame is separated from the second holding frame and moves on the X-axis as the first movable lens group is moved by manual zooming operation. A zoom lens barrel equipped with a macro mechanism.