JPH08234089A - Lens barrel with built-in converter lens - Google Patents

Abstract

PURPOSE: To further simplify a constitution, to miniaturize a lens barrel and to obtain an ultra short focal distance in addition to a focal distance by zooming without using a dedicated electrical and mechanical member in order to insert/detach a converter lens. CONSTITUTION: When the rotating force of a zoom motor is applied to a driving gear 21, a main movable frame 2 is moved with rotation in an optical axis direction, and a slave movable frame 3 is moved straight in the optical axis direction, and also, a cam frame 6 is moved with rotation in the optical axis direction. On the way from a wide-photo position to a storing position, a movable frame 9 for two-group is moved with rotation in the optical axis direction by the rotating force of the cam frame 6, and a movable frame 7 for three-group is moved with no rotation in the optical axis direction. By the relative rotating and straight-advancing action of two movable frames 7 and 9, the converter lens Lc is inserted from a retreat position into the optical path of an effective luminous flux, then, an optical system of an ultra short focal distance is set. When the cam frame 6 is still more rotated in the same direction, the converter lens Lc returns to the retreat position outside the optical path of the effective luminous flux, then, the lens barrel is brout into a storage state where the length of the lens barrel becomes the shortest.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom optical system lens which can be applied to various fields of equipment and devices which require a zoom optical system such as a normal camera, a video camera and a projector using a silver salt film. More specifically, with respect to the lens barrel, the zoom optical system is constructed by removably inserting a converter lens into a zoom optical system in which a plurality of lens groups move relative to each other along the optical axis to change the focal length. The present invention relates to a lens barrel having a variable power optical system capable of realizing a specific focal length that cannot be obtained by the system alone.

[0002]

2. Description of the Related Art A variable magnification optical system capable of realizing a specific focal length (super wide angle or super telephoto) which cannot be obtained by a zoom optical system alone by inserting a converter lens into the zoom optical system in a removable manner. A technique relating to a lens barrel having a built-in system is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-302711
JP-A-2-308113, JP-A-2-30821
No. 0, JP-A-2-308211, JP-A-2-
It is already known from JP-A-308212, JP-A-3-6971 and JP-A-3-11312.

[0003]

However, in the lens barrel technology disclosed in these publications, ultra-wide-angle photography or super-telephoto photography is provided outside the operation member (for example, seesaw knob) used for photography in the zooming area. In many cases, a dedicated operating member used for the case is required.Even if the dedicated operating member is not required, an electric driving means for inserting and removing the converter lens (for example, an electric motor) is provided separately from the driving means for zooming. Or a solenoid), or a special electric control means for inserting and removing the converter lens, which impairs the operability of the lens barrel, or This is a major cause of complicating the structure or configuration of the lens barrel.

In addition, in each of the publications, the mechanical movement means for inserting and removing the converter lens becomes complicated, which also contributes to the complicated structure. Furthermore, none of these publications discloses the problem or technique of shortening the lens barrel length when not in use, and therefore an attempt is made to obtain a lens barrel capable of shortening the lens barrel length. It is in a state where it cannot be used as a reference technology at the time.

The present invention has been made in view of such circumstances, and the first object thereof is to change the focal length while a plurality of lens groups relatively move on the optical axis. By inserting a converter lens in the zoom optical system so that it can be inserted and removed, a lens barrel incorporating a variable power optical system that achieves a specific focal length that cannot be obtained within the zooming area of the zoom optical system, i) It is possible to use the driving force of the electric motor for driving each moving lens group constituting the zoom optical system as it is without using a dedicated electric driving means as the driving force when inserting and removing the converter lens. Is possible,

(Ii) It is not necessary to particularly provide a complicated electric control means for inserting / removing the converter lens. (Iii) An ordinary zoom lens is used as a mechanical movement means for inserting / removing the converter lens. It is possible to make the structure simple by using the mechanical members possessed by as much as possible and to add a few unique members to it, and to make it a robust and highly precise structure,

(Iv) The diameter and length of the lens barrel need not be made particularly large. (V) No special operating member is provided for realizing a specific focal length and for shortening the lens barrel length, and It is an object of the present invention to provide a lens barrel having a built-in converter lens, which can achieve a specific focal length by an operation that is continuous with a normal zooming operation.

A second object of the present invention is to retract the converter lens out of the optical axis at the storage position so that the lens barrel length of the lens barrel when not in use can be shortened. An object of the present invention is to provide a lens barrel including a converter lens.

[0009]

In order to achieve the above object, the present invention provides a zoom optical system in which a plurality of lens groups change the focal length while relatively moving on the optical axis. In a lens barrel having a variable magnification optical system that realizes a specific focal length that cannot be obtained in the zooming region of the zoom optical system by inserting the converter lens in a removable manner, in the lens barrel or the lens. The zoom optical system is configured so that the plurality of lens groups can be relatively moved by operating the lens group driving means provided in the apparatus equipped with the lens barrel in the reciprocating direction. A plurality of lens groups that move on the optical axis while rotating around the optical axis when the lens group driving means is rotated in a predetermined direction; Les When the lens group driving means is rotated in a predetermined direction, the lens group driving means is configured to move straight on the optical axis without rotating, and the length of the lens barrel is set to the longest state. And a second state length when the first state length is shortened by a length corresponding to a zooming region of the zoom optical system from the first state length,
4 of the third state length when it is further shortened from the second state length and the fourth state length when it is in the shortest state
Each of the stages is set, and the length of the lens barrel can be sequentially changed from the first state length to the fourth state length by rotating the driving means in a predetermined direction. In addition, when the lens barrel is in the first state length, the plurality of lens groups have a focal length at one end of a zooming region of the zoom optical system. When the lens barrel is in the second state length, the plurality of lens groups have a focal length at the other end of the zooming region of the zoom optical system. The rotational movement lens group and the rectilinear movement lens group are set so that the lens barrels move to the first state length and the second state length, respectively. It is configured such that the converter lens, which has been previously placed in the retracted position in the lens barrel, can be inserted into the operating position in the zoom optical system by using the relative linear and rotational movements generated therebetween. , The specific focal length is obtained by the relative position of the converter lens when it is inserted in the zoom optical system, and the combined focal length of the inserted converter lens and the plurality of lens groups. It is characterized in that the relative position is set.

In order to achieve the second object, the present invention provides a lens barrel having the converter lens built-in, wherein when the lens group is moved to the storage position, the converter lens is placed outside the optical axis. The storage length of the lens barrel when not in use is shortened.

[0011]

The lens barrel having the built-in converter lens constructed as described above is used in a zoom optical system in which a plurality of lens groups change the focal length while relatively moving on the optical axis. By removably inserting the lens, a plurality of lens groups can be moved relative to each other in the lens barrel that has a built-in variable magnification optical system that realizes a specific focal length that cannot be obtained within the zooming area of the zoom optical system. And a plurality of lens groups moved by the lens group driving means are rotated around the optical axis when the lens group driving means is rotated in a predetermined direction. However, at least one rotationally movable lens group that moves on the optical axis and a linearly movable lens group that linearly moves on the optical axis while remaining unrotated are configured separately.

In order to realize a specific focal length which cannot be obtained in the normal zooming area of the zoom optical system, it is set as an extension of the operation for realizing the focal length in the zooming area of the lens group driving means. By utilizing the operation of the lens group driving means described above, a relative rectilinear movement and a rotational movement are generated between the rotational movement lens group and the rectilinear movement lens group, and the relative rectilinear movement and the rotational movement cause the converter lens to zoom in and out. It is inserted at a predetermined position of the system to obtain a desired specific focal length.

The lens barrel having the built-in converter lens constructed as described above is in a non-use state as a structure for retracting the converter lens out of the optical axis when the lens group is moved to the storage position. The storage length of the lens barrel in is reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a lens barrel incorporating a converter lens of the present invention will be described in detail below with reference to an embodiment shown in the drawings. FIG. 1 is one of the sectional views showing the configuration of a lens barrel incorporating a converter lens according to the present invention. What is drawn above the center line (which is also the optical axis O) is a zoom optical system. FIG. 4 is a cross-sectional view of the lens barrel in the long focal length (TELE) state, and what is drawn below the center line is the lens when the zoom optical system is in the short focal length (WIDE) state. It is sectional drawing of a lens barrel.

FIG. 2 is another cross-sectional view of the lens barrel incorporating the converter lens according to the present invention. What is drawn above the center line is that the zoom optical system is within its own zooming area. Ultra short focal length (S-WID
FIG. 7E is a cross-sectional view of the lens barrel in the state of E), and what is drawn below the center line is a cross-sectional view of the lens barrel in the stored state (non-use state).

FIGS. 3 and 4 are views showing the state of the main part when the converter lens is in the retracted position. Of these, FIG. 3 is a schematic sectional view taken along the line AA of FIG. , Fig. 4
3 is a schematic side view of the main part of FIG. 3, and FIG. 5 is a schematic perspective view for explaining the operating principle of the converter lens. FIG. 6 is a schematic cross-sectional view taken along the line BB of FIG. 2 showing the state of the main part when the converter lens is inserted in the working position.

1 to 6, the zoom optical system incorporated in the lens barrel of the illustrated embodiment has a first lens group L ₁ and a second lens group L ₁ which are sequentially arranged from the object side. L ₂ and 4 of the third lens group L ₃ and the fourth lens group L ₄
It is configured as a zoom optical system (L _{1 to} L ₄ ) having a group configuration. In this case, the first group lens group L ₁ is a lens group having a two-group three-element configuration, the second group lens group L ₂ is a lens group having a two-group two-element configuration, and the third group lens group is L ₃
Are each configured as a lens group L ₃ having a three-group three-element configuration.

On the other hand, the fourth lens group L ₄ is constructed as a lens group having a two-group two-lens structure, and the upper part (upper half of FIG. 2) of the fourth lens group L ₄ is located above the center line of FIG. As shown in the drawn sectional view, it is partially cut into an arc shape. This is a measure for accommodating the gear train means 25 to 27 for focusing, which will be described later, in the partially cut space portion.

That is, passing through the fourth lens group L ₄ , the short side direction of the screen of the 35 mm film (the width direction of the film)
The effective luminous flux that goes toward the lens passes through a position that is not too high from the optical axis O. Therefore, when the fourth lens group L ₄ is viewed in plan view, a shallow semicircular shape (arc shape) formed at a position higher than a predetermined height is formed. The area of () is a non-use area of the photographing light flux. Therefore, if the front lens and the rear lens in the _fourth lens group L ₄ are cut by a plane parallel to the optical axis O at each predetermined height point, each lens has a flat upper semi-circular plane. The deformed lens has a shape, and the portion corresponding to the shallow semicircular region of each lens is formed as a space portion.

In this case, since the rear lens is located near the film surface F, the height of the effective light beam passing through the rear lens from the optical axis O is the optical axis O of the effective light beam passing through the front lens. Since the height is higher than the height from above, the space portion 16a formed here is a space portion having a two-stage structure in which a step is formed in a portion near the optical axis O.

Since this space portion can be utilized as a storage space portion 28 for installing various mechanical members, as shown in FIG. 11, from the output gear 25 of the focus motor 24, Focusing gear train means 25 to 27, which reach the small gear 27 at the final stage via an appropriate reduction gear train 26, can be housed in the housing space 28 so that the fourth lens group L ₄ of the fourth lens group L ₄ can be housed. The upper part is cut off.

[0022] Now, the lens group L ₁ ~L ₄ group 4, at the time of zooming, by relatively moving the optical axis O depicts the relative motion trajectories shown in FIG. 7, for example, from the long: focal length f _T The optical design is such that the focal length can be continuously changed within the zooming region up to the short focal length f _W , and by relatively moving the zooming region beyond the ultra-long focal length f _T side to a predetermined position. Long focal length (focal length in macro) f longer than the long focal length f _T
Optically designed to obtain _TM .

Then, an electromagnetically driven shutter unit S having, for example, a shutter blade S ′ that also serves as a diaphragm is located at an intermediate position between the second lens group L ₂ and the third lens group L _3. There is. However, the shutter unit S
The description itself is omitted because it is not a characteristic part of the present invention. On the other hand, in the lens barrel of the illustrated embodiment, a converter lens Lc for realizing a specific focal length which is not obtained in the zooming regions of the zoom optical systems L _{1 to} L ₄ , for example, an ultra-short focal length f _SW , It is provided between the second lens group L ₂ and the third lens group L ₃ of the zoom optical system.

In this case, as will be described later, the converter lens Lc has a length that allows the lens barrel to realize the zooming regions of the zoom optical systems L _{1 to} L ₄ , that is, the zoom optical system. When L _{1 to} L ₄ realize the focal length within the zooming area, they are located at the retracted position (the position shown in FIG. 1) out of the effective light beam path of the zoom optical system, and the lens barrel is zoom optical. If the length of the system L _{1 to} L ₄ exceeds the zooming area,
That is, when the zoom optical systems L _{1 to} L ₄ are out of the zooming area, they are located at a predetermined operating position (position in FIG. 2) preset on the optical axis O, and further the lens barrel. If there it is set to a non-use state of the zoom optical system L ₁ ~L _4, i.e., when the zoom optical system L ₁ ~L ₄ is in the retracted state, the optical axis O outside the preset predetermined It is configured to be located at the retracted position.

[0025] In the following description,: focal length f _T of the TELE end each length: focal length f _T, the focal length f _TM during macro longer long focal length f _TM than: focal length f _T of the TELE end the focal length f _W of the short focal length f _W WIDE end, the ultra-short focal length f _SW will be referred to as a focal length f _SW of S-WIDE.

Next, such zoom optical systems L _{1 to} L ₄
The structure of the lens barrel including the converter lens Lc will be described. Reference numeral 1 denotes an apparatus or device that requires a zoom optical system, for example, a fixed ring fixed to a camera. An optical axis O is formed on a portion of the inner peripheral surface on the side of the object side while rotating a main moving frame 2 described later. A female helicoid screw 1a having a plurality of threads, for example, is formed to move in the front-rear direction along.

Further, in the portion of the inner peripheral surface on the side of the film surface F, for example, three linear guide grooves 1b for making the connecting ring 10 to be described later linearly forward and backward along the optical axis O are formed. Further, a notch portion 1c for mounting a drive gear 21 to be described later is formed in a part of a collar portion formed in an intermediate portion of the fixed ring 1.

Reference numeral 2 denotes a main moving frame which is provided between the inner portion of the fixed ring 1 and the outer portion of a guide ring 5 to be described later so as to be rotatable relative to the both rings 1, 5.
As shown in FIG. 8, a male helicoid screw 2a which is precisely screwed with the helicoid screw 1a of the fixing ring 1 is formed in a predetermined range on the outer peripheral surface thereof, and the drive gear 21 is formed at the rear end of the outer peripheral surface. A gear portion 2b that meshes is formed.

In this case, the gear portion 2b is the main moving frame 2
Is spirally formed so as to have a predetermined optical axis direction length as shown in FIG. 8 so that it can move while rotating in a predetermined range in the optical axis O direction. The predetermined length in the optical axis direction will be described in detail in the section "Operation or Action". In addition, a plurality of lead grooves 2c and a predetermined number of connecting grooves 2d are formed on the inner peripheral surface of the main moving frame 2 for moving the sub moving frame 3 to be described later in the front-rear direction along the optical axis O. ing.

Further, an inner flange portion (step portion) 2e formed at the rear end portion of the main moving frame 2 is provided with a flange portion of a guide ring 5 and an outer peripheral end surface of the coupling ring 10 on the object side, which will be described later. It is configured to be sandwiched between the rings 5 and 10 such that they can rotate relative to each other and cannot move relative to each other in the optical axis O direction. Reference numeral 3 denotes a sub-moving frame provided inside the main moving frame 2 so as to be movable (expandable and contractible) in the front-rear direction along the optical axis O. The sub-moving frame 3 keeps its inner surface in a non-rotating state. While it is provided with a key groove 3a for moving straight. The sub-moving frame 3 serves as a first-group moving frame for moving the first lens group L ₁ along the optical axis O.

Reference numeral 4 denotes an engaging piece which is planted on the outer peripheral surface of the sub-moving frame 3 and is configured to be fitted precisely into the lead groove 2c of the main moving frame 2. The engagement piece 4 plays a role of moving the slave moving frame 3 along the optical axis O in the front-rear direction in cooperation with the lead groove 2c when the main moving frame 2 rotates in the forward and reverse directions. Reference numeral 5 is a guide ring provided over the inner portion of the main moving frame 2 and the inner portion of the sub moving frame 3, and a key portion 5a that fits into the key groove 3a of the sub moving frame 3 is formed on the outer peripheral surface thereof. ing.

The guide ring 5 is fixed at its rear end portion so as to be integrated with a connecting ring 10 which will be described later. Regarding the relationship between the three rings, the guide ring 5, the connecting ring 10 and the fixed ring 1. It will be described later. Further, one circular groove 5b is formed on the peripheral wall portion of the guide ring 5.
And two rectilinear grooves 5c and 5d are formed respectively, and a flange portion 5e is formed at the rear end portion of the guide ring 5. Reference numeral 6 denotes a cam frame fitted to the inner peripheral surface of the guide ring 5 so as to be relatively rotatable, and the flange portion 5 of the guide ring 5 is provided.
The inner surface of e and a stop ring (snap ring) 23 fitted to the tip portion of the guide ring 5 are configured so as to move in the optical axis direction integrally with the guide ring 5.

A connecting pin 11 is planted near the rear end of the cam frame 6, and the connecting pin 11 is fitted into the arcuate groove 5b of the guide ring 5 and the connecting groove 2d of the main moving frame 2 at the same time. As a result, the main moving frame 2 can also rotate integrally. As shown in FIG. 9, a third group moving cam groove 6a, a fourth group moving cam groove 6b, and a rectilinear groove 6c are formed on the peripheral wall portion of the cam frame 6, respectively. The third group moving cam groove 6a and the fourth group moving cam groove 6b will be described in detail in the section "Operation or Action" described later.

Reference numeral 7 denotes a third-group moving frame fitted to the inner peripheral surface of the front portion of the cam frame 6, and the portion located on the right side in the drawing is formed as a hollow end wall 7a. Then, in the three regions on the end face wall portion 7a facing the three leg portions 8d of the fourth-group moving frame 8 described later, and in one region facing the focus motor 24 described later, the three When the group moving frame 7 and the fourth group moving frame 8 move relative to each other on the optical axis O in a direction of approaching each other, that is, between the third group moving frame 7 and the fourth group moving frame 8. The spacing is shown in Figure 2.
When the state shown in the sectional view below the center line of is reached,
A leg receiving area (not shown) having a shape into which the lateral legs 8d formed in the fourth-group moving frame 8 can enter, and a motor receiving area having a shape into which the tail of the focus motor 24 can enter. (Not shown) are formed respectively.

Further, on the outer peripheral surface of the third-group moving frame 7, there are arranged rollers 12 fitted into a plurality of pins that are planted at equal intervals. 3 group moving cam groove 6a formed in the peripheral wall portion of the guide ring 5 and the forward linear groove 5c formed in the peripheral wall portion of the guide ring 5 at the same time. The movable frame 7 is configured to be movable in the optical axis direction in a non-rotated state.

Further, on the peripheral wall portion of the third-group moving frame 7,
As shown in FIG. 10, a second group moving cam groove 7 for moving in the optical axis direction while rotating a second group moving frame 9 described later.
Although b is formed, the second group moving cam groove 7b will be described in detail in the section of the second group moving frame 9 and the section "Operation or action" described later. Reference numeral 8 is a movable frame for the fourth group, which is fitted to the inner peripheral surface of the rear portion of the cam frame 6, and has a structure of relative movement between the movable frame 7 for the third group and a fourth group lens group holding frame 16 described later. In relation, it is structured as follows.

First, a portion closer to the film surface F than the inner flange portion 8a located at the center in the drawing is formed as a cylindrical portion 8b, and the inner peripheral surface thereof is planted in the fourth group lens group holding frame 16. A rectilinear groove 8c into which the connected connecting pin 17 is fitted is formed. Then, the inner flange portion 8 of the fourth-group moving frame 8
A plurality of (at least three) laterally extending leg portions 8d are projectingly formed in the portion closer to the object side than a, and the outer peripheral surfaces of the leg portions 8d at the plural portions are arranged along the optical axis O. The cam frame 6 can move straight in the direction (sliding), and the cam frame 6 is a moving frame 8 for the fourth group.
It is configured to fit with the inner peripheral surface of the cam frame 6 under the condition that the cam frame 6 can be relatively rotated with respect to.

The plurality of leg portions 8d are formed at unequal angular intervals in the illustrated embodiment, and one of the plurality of space portions 8e formed between the leg portions 8d is It is configured to be used as a space for housing a focus motor 24 with an output gear, which will be described later. In order to bring the two moving lens frames (the third group moving frame and the fourth group moving frame 8 in the illustrated example) adjacent to each other to the smallest distance, both moving lens frames are as if both hands were used. Since the structure in which the fingers are crossed so as to be combined belongs to the publicly known as a lens barrel of a zoom lens, detailed illustration and description thereof will be omitted.

Further, on the outer peripheral surface of the moving frame 8 for the fourth lens group, there are arranged fitting rollers 13 fitted into a plurality of pins planted at equal intervals. The fitting roller 13 is simultaneously fitted into the fourth group moving cam groove 6b formed in the peripheral wall portion of the cam frame 6 and the rearward rectilinear groove 5d formed in the peripheral wall portion of the guide ring 5, and the cam frame 6 Is rotated, 3
Similar to the case of the group moving frame 7, the fourth group moving frame 8 is also configured to be movable in the optical axis direction in a non-rotating state.

As described above, the reference numeral 9 designates a movable frame 7 for the third group so that it can move in the optical axis direction on the inner peripheral surface of the movable frame 7 for the third group.
It is a moving frame for the second group that is fitted so as to be relatively rotatable with respect to the outer peripheral surface of which a plurality of fitting rollers 14 arranged at equal intervals are provided.

The fitting roller 14 includes a cam groove 7b for moving the second group and a cam frame 6 formed in the peripheral wall of the moving frame 7 for the third group.
Is fitted in the straight groove 6c formed in the peripheral wall portion of
When the cam frame 6 rotates and moves in the optical axis direction, the second-group moving frame 9 moves in the optical axis direction together with the cam frame 6 by the amount of the movement, and the process of moving in the optical axis direction. Is configured to be rotated with respect to the third group moving frame 7 by the second group moving cam groove 7b of the third group moving frame 7.

That is, when the cam frame 6 rotates,
It is configured so that it can move in the optical axis direction together with the cam frame 6 while rotating with respect to the third-group moving frame 7. Reference numeral 10 is a connecting ring fixedly attached to the rear end portion of the guide ring 5, and a connecting protrusion 10a formed on the outer periphery of the connecting ring 10 is configured to be fitted in the straight guide groove 1b of the fixed ring 1. There is. Therefore, the guide ring 5 (which is also the connecting ring 10) is connected to the fixed ring 1 while being movable in the optical axis direction but not rotating around the optical axis O.

Reference numeral 15 denotes a focus ring rotatably fitted to the inner peripheral surface of the above-mentioned moving frame 8 for the fourth group, and the peripheral wall portion thereof has a fourth group lens group holding frame 16 to be described later on the optical axis O during focusing. A focusing cam groove 15a for moving along is formed, and an inner gear portion 15b that meshes with a small gear 27 described later that is finally rotated by the focus motor 24 is formed on the inner peripheral surface of the flange portion. ing.

Reference numeral 16 denotes a fourth lens group holding frame for holding the fourth lens group L ₄ , which is fitted on the inner peripheral surface of the focus ring 15 so as to be movable in the optical axis direction. The holding frame 16 has a plane shape that substantially matches the plane shapes of the front lens and the rear lens in the _fourth lens group L ₄ , as shown in the sectional view drawn upward from the center line in FIG. It is configured as a holding frame.

That is, like the front lens and rear lens in the _fourth lens group L ₄ , it is formed so as to be cut so as to be parallel to the optical axis O at a point of a predetermined height from the optical axis O. . As a result, the fourth lens group holding frame 16
Is configured as a holding frame having a planar shape of "upward C-shape", and is a super semicircular fourth lens group L
₄ is this “upward C-shaped” 4th lens group holding frame 1
It will be fixedly held by 6.

Further, a connecting pin 17 is planted on the outer peripheral surface of the fourth lens group holding frame 16. The connecting pin 17 is fitted in the focusing cam groove 15a of the focus ring 15 and the straight advance groove 8c of the fourth-group moving frame 8 at the same time, and when the focus ring 15 rotates,
The group lens group holding frame 16 can be moved in the front-rear direction along the optical axis O in a non-rotated state.

Reference numeral 18 denotes a first-group lens group holding frame which holds the first-group lens group L ₁ and is fixed to the inside of the front end of the slave moving frame 3. A second lens group holding frame 19 holds the second lens group L ₂ and is fixed inside the second lens group moving frame 9.
Reference numeral 20 denotes a third group lens group holding frame that holds the third group lens group L ₃ and is fixed inside the third group moving frame 7. Reference numeral 21 denotes a drive gear rotatably supported by a support shaft 22 provided in the cutout portion 1c of the fixed ring 1, and a reversible rotatable zoom motor provided on the camera side or the lens barrel.
For example, it is configured to mesh with the output gear of the pulse motor through an appropriate reduction gear train (neither is shown).

Reference numeral 24 shown in FIG. 2 indicates 4 during focusing.
The lens group holding frame 16 (the fourth lens group L ₄ ) is moved to the optical axis O.
As shown in the sectional view drawn upward from the center line of FIG. 2, it is a focus motor for moving in the front-back direction along the inner side of the inner flange portion 8 of the fourth-group moving frame 8 as shown in the sectional view.
In a state of penetrating a and protruding to the film surface F side,
It is configured to be attached to the end surface on the object side of the inner flange portion 8a of the fourth-group moving frame 8. Further, the focus motor 24 is composed of, for example, a pulse motor that rotates in forward and reverse directions.

Reference numeral 25 denotes an output gear fixed to the output shaft of the focus motor 24. As shown in FIG. 11, a final stage small gear meshed with the inner gear portion 15b of the focus ring 15 via an appropriate reduction gear train 26. It is configured to be connected to the gear 27. Reference numeral 30 denotes the base plate of the shutter unit S described above, and a light beam transmitting hole 30a is formed in a portion corresponding to the effective light beam optical path of the zoom optical system. This ground plate 3
Reference numeral 0 denotes a second lens group holding frame 19 inside the third lens group moving frame 7.
(It is also the second group moving frame 9) and the third group lens group holding frame 20.
It is fixedly arranged between and.

Reference numeral 31 denotes an insertion / removal movement of the converter lens Lc between the retracted position (the position shown in FIG. 3) out of the effective light beam path of the zoom optical system and the operating position (the position shown in FIG. 6) on the optical axis O. This is a converter lens arm for causing the back surface of the base plate 30 (a shutter blade S ′ that also serves as an aperture) by the pivot 32.
The frame body 3 configured to be rotatably supported on a surface opposite to the surface on which the converter lens Lc is held, and which holds the converter lens Lc at the rotating end of the arm portion of the converter lens arm 31.
1a, and as shown in FIGS. 5 and 6, for rotating the converter lens arm 31 at the end of the rising portion 31b that rises at right angles to the arm portion (parallel to the optical axis O direction). The action pin 33 is provided so as to be orthogonal to the optical axis O direction.

In this case, the retracted position of the converter lens Lc is determined by the position of the converter lens Lc when the frame 31a of the converter lens arm 31 contacts the inner peripheral wall surface of the third-group moving frame 7. And again
The working position of the converter lens Lc is such that the working pin 33 is 2
The position is determined by the position of the converter lens Lc when the S-WIDE switching end cam 9a of the group moving frame 9 is held at a predetermined position (position where the converter lens arm 31 is placed in the working posture described later). It is configured.

In the following description, the attitude of the converter lens arm 31 when the converter lens Lc is in the "retracted position" is referred to as the retracted attitude, and the converter lens Lc
The posture of the converter lens arm 31 when is in the working position is referred to as the “working posture”.

Reference numeral 34 is a tension spring composed of a coil spring or the like wound around a pivot 32 for constantly biasing the converter lens arm 31 in a counterclockwise direction, one end of which is an inner peripheral wall of the third-group moving frame 7. , And the other end is hooked on the arm portion of the converter lens arm 31. As a result, when the converter lens arm 31 is in the free state, the tension spring 34 places the converter lens arm 31 in the retracted position.

The second group moving frame 9 has an S for switching the converter lens arm 31 from the retracted posture to the working posture.
The end surface cam 9a for switching -WIDE is the second group moving frame 9
Is formed on a cylindrical end surface portion on the film surface F side. The S-WIDE switching end surface cam 9a is a converter lens when the second-group moving frame 9 is rotated by a predetermined value or more relative to the third-group moving frame 7 (which is also the base plate 30) and comes close to it. The end surface cam 9a has a cam slant surface for engaging the action pin 33 of the arm 31, and the end surface cam 9a holds the action pin 33 at a predetermined position by the cam surface continuous with the cam slant surface to actuate the converter lens arm 31 in a working posture. It is formed so as to be held on.

That is, by zooming operation for changing the focal length from the focal length f _W at the WIDE end to the focal length f _SW at the S-WIDE position, the two groups can be seen from the relative movement locus shown in FIG. Moving frame 9 for the third group moving frame 7
When relatively approaching and rotating with respect to the (base plate 30), the end face cam 9a for S-WIDE switching pushes the action pin 33 to push the converter lens arm 31 around the pivot 32, and then the end face cam 9a. Is the action pin 33
Is held at a predetermined position to hold the converter lens arm 31 in the working posture.

Further, when the lens barrel is operated to the retracted state, the second-group moving frame 9 moves to the film surface F side, but the third-group moving frame 7 comes closer to the film surface F. 2 as a result (or relative)
The group moving frame 9 is separated from the third group moving frame 7 again, and the holding of the action pin 33 by the end face cam 9a is released, and the converter lens arm 31 is biased counterclockwise by the tension spring 34 to be in the retracted posture. Returned to. The relative position of the converter lens arm 31 and the end surface cam 9a will be described in detail in the section "Operation or Action" described later.

Although not shown in the figure, the lens barrel having the above-described structure is provided on the lens barrel side or the camera side, such as a lens barrel for controlling movement of each lens frame (moving frame and holding frame). Appropriate total control circuit means for controlling the entire camera, suitable zoom motor drive circuit means for driving the zoom motor, suitable focus motor drive circuit means for driving the focus motor 24, suitable automatic focusing control means, seesaw type It is configured to have a zooming operation member and the like.

Next, the operation or action of the lens barrel of the illustrated embodiment will be described for each usage mode.
In the following description, “forward rotation” of the zoom motor or the like means that the lens groups L _{1 to} L ₄ move from positions in the TELE region toward positions in the WIDE region, and “rotate in the opposite direction”. Means that each lens group L ₁ ~
The direction in which L ₄ moves in the direction opposite to the case in which it is the positive direction is set.

[Focal Length Changing Operation or Function in Zooming Regions f _{T to} f _W ] When the lens barrel is in the state of the sectional view drawn above the center line in FIG. 1, the zoom optical system L ₁ to L ₄ is located at a position that realizes the focal length f _T at the TELE end. In this state, when the seesaw type zooming operation member (not shown) is operated in a direction (forward direction) in which each of the lens groups L _{1 to} L ₄ moves from the TELE area to the WIDE area, the overall control circuit means The zoom motor drive circuit means is provided with a control command to drive a zoom motor (not shown) in the positive direction, for example, to rotate the zoom motor in the positive direction.

When the zoom motor rotates in the forward direction, its rotational force is transmitted to the drive gear 2 via the output gear and the reduction gear train.
1 and further transmitted to the main moving frame 2 via the gear portion 2b of the main moving frame 2, the main moving frame 2 has its own male helicoid screw 2a and the female helicoid screw 1a of the fixing ring 1. On the optical axis O from the position of the sectional view drawn above the center line of FIG. 1 toward the position of the sectional view drawn below while rotating in the positive direction with respect to the fixed ring 1 by the screwing action of Will move to the right.

When the main moving frame 2 rotates and moves rightward in this manner, the guide ring 5 and the connecting ring 10 provided inside the main moving frame 2 become together with the main moving frame 2. It will move to the right. This is because the flange portion of the guide ring 5 and the outer peripheral end surface of the coupling ring 10 can relatively rotate the inner flange portion 2e of the main moving frame 2 and move integrally with the main moving frame 2 in the optical axis O direction. This is because it is sandwiched between the states.

At this time, the guide ring 5 and the connecting ring 10
Are integrally formed with each other, and the connecting ring 10
Since the connecting projection 10a of is fitted into the straight guide groove 1b of the fixed ring 1, the guide ring 5 and the connecting ring 1
0 moves to the right in a non-rotating state due to the rotation-preventing action (straight guide action) of the connecting protrusion 10a and the straight guide groove 1b.

On the other hand, when the main moving frame 2 rotates and moves to the right, the sub moving frame 3 provided between the main moving frame 2 and the guide ring 5 is drawn above the center line in FIG. From the position of the cross section shown in FIG. 1 to the position of the cross section shown below, the light beam moves straight on the optical axis O to the right. This is a lead action by the engagement piece 4 fixed to the outer peripheral surface of the sub-moving frame 3 and the lead groove 2c formed on the inner peripheral surface of the main moving frame 2.
In addition, a straight guide function is exerted by the rotation preventing effect of the key groove 3a formed on the inner peripheral surface and the straight key portion 5a formed on the non-rotating guide ring 5 on itself.

By the way, the flange portion 5e of the guide ring 5
When the main moving frame 2 rotates and moves to the right, the cam frame 6 sandwiched between the fixing ring (snap ring) 23 and the stop ring (snap ring) 23 moves together with the guide ring 5 and the connecting ring 10 to the optical axis O. Move up to the right. At this time, since the connecting pin 11 on the cam frame 6 side is engaged in the connecting groove 2d on the main moving frame 2 side, the main moving frame 2 and the cam frame 6 rotate in the right direction while rotating integrally. Will move.

When the cam frame 6 rotates in the forward direction in this manner, the third-group moving cam groove 6a formed in the front portion of the cam frame 6 and the rectilinear groove 5 formed in the front portion of the guide ring 5
Since the fitting roller 12 that is simultaneously fitted to c is subjected to the cam action of the third-group moving cam groove 6a and the straight-moving guide action of the straight-moving groove 5c, this fitting roller 12
The movable frame 7 for the third group, which is integrated with the above, moves straight to the right on the optical axis O from the position of the sectional view drawn above the center line of FIG. 1 toward the position of the sectional view drawn below. Move to.

On the other hand, 4 formed on the rear portion of the cam frame 6
The fitting roller 13 that is simultaneously fitted into the group moving cam groove 6b and the rectilinear groove 5d formed in the rear portion of the guide ring 5.
However, the cam action by the fourth group moving cam groove 6b and the rectilinear groove 5d
Therefore, the moving frame 8 for the fourth lens group, which is integrated with the fitting roller 13, is also subjected to the linear guide action by the cross section drawn below the position of the cross section drawn above the center line of FIG. It moves straight to the right on the optical axis O toward the position shown in the figure.

In this way, when the cam frame 6 rotates and the third-group moving frame 7 moves straight to the right, the second-group moving cam groove 7b formed in the third-group moving frame 7 and the cam frame 6 are formed. The fitting roller 14 that is simultaneously fitted to the straight groove 6c is
The second group moving cam groove 7b receives the cam action and the straight advance groove 6c provides the straight advance guide action. Therefore, the second-group moving frame 9 integrated with the fitting roller 14 moves from the position of the sectional view drawn above the center line in FIG. 1 to the position of the sectional view drawn below the cam frame 6 as shown in FIG. It moves to the right on the optical axis O while rotating integrally with.

When the drive gear 21 rotates in the positive direction in this way, the frame members 2, 6, 7 to 9 and the rings 5 and 10 are sectional views drawn above the center line of FIG. From the position of, to the position of the sectional view drawn below, the respective movements are as follows.

(A) The main moving frame 2 moves rightward on the optical axis O while rotating, (b) the sub moving frame 3
The (first group moving frame) linearly moves rightward on the optical axis O in the non-rotated state. (C) The guide ring 5 and the coupling ring 10 remain in the non-rotated state of the optical axis. (B) The cam frame 6 moves rightward on the optical axis O while rotating integrally with the main moving frame 2 while moving linearly on the O rightward (d). The group moving frame 7 and the fourth group moving frame 8 move (go straight) to the right on the optical axis O in a non-rotated state, respectively. (F) The second group moving frame 9
It moves rightward on the optical axis O while rotating integrally with the cam frame 6.

As a result, the respective lens units L _{1 to} L ₄ constituting the zoom optical system draw the respective movement loci shown in FIG. 7 while the first lens barrel is in the longest state. Of the WIDE end corresponding to the second state length when the first state length is shortened by the length corresponding to the zooming region from the position where the focal length f _T of the TELE end corresponding to the state length is realized. It will move to a position that realizes the focal length f _W.

On the other hand, the zoom optical systems L _{1 to} L ₄ are
In a state where the focal length f _W at the E end is realized, the seesaw type zooming operation member is moved to each lens group L _{1 to} L ₄
Is operated in a direction (reverse direction) such that the lens moves from the WIDE area to the TELE area, the integrated control circuit means controls the zoom motor (not shown) to rotate in the reverse direction, and the drive gear 21 is reversed. Will be rotated in the direction.

At this time, the respective frame members 2, 6, 7 ...
9 and each of the rings 5 and 10 described above from the position of the sectional view drawn below the center line of FIG. 1 toward the position of the sectional view drawn above as the drive gear 21 rotates in the reverse direction. The lens groups L _{1 to} L ₄ move in the opposite directions to the items (a) to (f), and the WID
It moves to the left from the position where the focal length f _W at the E end is realized to the position where the focal length f _T at the TELE end is realized.

As described above, in the illustrated embodiment, by operating the seesaw type zooming operation member in the forward and reverse directions, the respective lens groups (zoom optical systems) L _{1 to} L ₄ are moved to the zooming areas f _{T to} f. The focal length within the zooming regions f _{T to} f _W is obtained by moving the optical axis O in the front-back direction within the range of _W.

In this case, the lens groups L _{1 to} L ₄ are TEL
When the focal length f _T at the E end and the focal length f _W at the WIDE end are realized, an appropriate position control means,
For example, each position of the sub-moving frames 3 to 4 moving frame 8 which is the moving frame for the first group is detected by using an electric position detecting means or the like, and this electric detection information is introduced into the general control circuit means. By configuring the zoom motor to TEL
It is configured in advance so as to stop at a position or phase corresponding to the focal length f _T at the E end and the focal length f _W at the WIDE end.

In the process in which the lens units L _{1 to} L ₄ move in the front-back direction on the optical axis O within the range of the zooming regions f _{T to} f _W , the second-group moving frame 9 moves for the third group. Within the frame 7, the second group moving frame 9 is rotated relative to the third group moving frame 7 by a certain angle (angle corresponding to the circumferential length of the second group moving cam groove 7b). The S-WIDE switching end cam 9a moves so as to approach the action pin 33 on the converter lens arm 31, but in the illustrated embodiment, both members 9 and 33 contact at the relative rotation angle at this time. The relative positions of both members 9 and 33 are set in advance so as not to do so. Therefore, within the range of zooming regions f _{T to} f _W , the end face cam 9a for switching S-WIDE and the action pin 3 are provided.
3 means to keep close to each other.

[Focusing Operation or Action] When focusing is performed in the lens barrel having such a configuration, the focus motor 24 is rotationally driven in the forward and reverse directions based on, for example, a photographing distance control signal from an automatic focusing control means (not shown). By doing. In the illustrated embodiment, for example, when the automatic focusing control means measures the subject distance at that time, it is configured to output a photographing distance control signal matching the subject distance at that time to the total control circuit means. The control circuit means calculates the amount of rotation of the focus motor 24 according to the shooting distance control signal and outputs the calculation result to the focus motor drive circuit means.

Therefore, the focus motor 24 rotates in the forward or reverse direction by the rotation amount instructed by the focus motor drive circuit means. The rotational force of the focus motor 24 at this time is generated from the output gear 25 fixed to the output shaft of the focus motor 24, as shown in the sectional view drawn above the center line of FIG. 2 and the partial plan view of FIG. After being transmitted to the final stage small gear 27 through the reduction gear train 26, and further transmitted from the small gear 27 to the inner gear portion 15b of the focus ring 15, the focus ring 1
5 rotates in the positive direction, for example, in the fourth-group moving frame 8 with respect to the fourth-group moving frame 8 by an amount corresponding to the calculation result of the integrated control circuit means.

At this time, the connecting pin 17 planted in the fourth group lens group holding frame 16 is simultaneously fitted in the focusing cam groove 15a of the focus ring 15 and the straight groove 8c of the fourth group moving frame 8. The connecting pin 17 and the fourth-group lens group holding frame 16 integrated with the connecting pin 17 serve as a focusing cam groove 15 that acts on the connecting pin 17.
Due to the cam action of a and the rotation preventing action of the rectilinear groove 8c, for example, the film moves linearly in the direction of the film surface F in the figure.

That is, the fourth lens group holding frame 16 moves to the right along with the rotation of the focus ring 15 by an amount determined by the calculation result of the integrated control circuit means at that time and the shape of the focusing cam groove 15a. 7 to reach the position of L ₄ ^′ shown in FIG. 7, and focusing is performed in accordance with the subject distance at that time. Such focusing operation is performed in the zooming regions f _{T to} f of the zoom optical systems L _{1 to} L _4.
This can be performed within _{W and} at any time when the converter lens Lc described below is inserted.

[From zooming areas f _{T to} f _W to S-WI
Operation or Action When Switching DE to Focal Length f _SW ] As described above, in the present invention, a specific focal length that cannot be obtained by zooming in the normal zooming regions f _{T to} f _W , for example, an ultra-short focal length ( The focal length f _SW of S-WIDE is obtained by inserting the converter lens Lc at a predetermined operating position set on the optical axis O.

In this case, in the illustrated embodiment, each lens group (zoom optical system) L _{1 to} L _{4 is connected} to the focal length f at the WIDE end.
It is configured to be operated by further operating the seesaw type zooming operation member in the forward direction in a state where it is placed at a position where _W is realized. That is, when the zoom motor from forward operation of the seesaw zooming operation member is rotated in the forward direction, the position of the center line from the drawn downward cross-sectional view of FIG far (the position of the focal length f _W of the WIDE end) The main moving frame 2 which has been stopped has the drive gear 21 and its own gear portion 2b.
The guide ring 5 and the coupling ring 10 are moved straight to the right while being further rotated by the screwing action with the cam ring 6, and the cam frame 6 is rotated integrally with the main moving frame 2. While moving to the right.

In this case, in the illustrated embodiment, the third group moving cam groove 6a and the fourth group moving cam groove 6b formed in the cam frame 6 and the second group moving cam groove formed in the third group moving frame 7 are formed. 7
Since the cam shape with respect to b is set to a cam state of a predetermined angle in a region (range) in the direction toward the film surface F from the position of the focal length f _W at the WIDE end, each lens group L ₁
The first lens group L ₁ and the fourth lens group L ₄ of ~L _4, without changing the relative relationship positions of each other, FIG. 2
Position of the cross-sectional view drawn above the center line of the (S-WID
Move to a position that realizes the focal length f _{SW of} E).

Of the lens groups L _{1 to} L ₄ , the second lens group L ₂ and the third lens group L ₃ are separated from the first lens group L ₁ and the fourth lens group L ₄ , respectively. The mutual relative positions are brought close to each other, and the positions are moved to the position of the cross-sectional view drawn above the center line of FIG. 2 (the position for realizing the focal length f _SW of S-WIDE). The principle (point) of the movement of the movable frames 3, 7 to 9 at this time is the same as that of the movable frames 3, 7 to 9 in the zooming areas f _{T to} f _W , but the parallel movement is performed. The cam amount in the cam state is set to, for example, the lead amount of the lead groove 2c of the main moving frame 2 so that the distance between the four lens group moving frames 3 and 7 to 9 on the optical axis changes as described above. It shall be set accordingly.

The S-WID corresponding to the third state length when the focal length f _W at the WIDE end corresponding to the second state length is further shortened from the second state length from the realization position.
Each moving frame 3,7 to the position where the focal length f _SW of E is realized
In the moving process of 9, the second-group moving frame 9 moves straight ahead while relatively rotating with respect to the third-group moving frame 7 (integrated with the main plate 30), so that the focal length f _W at the WIDE end is realized. Position, the working pin 33 on the converter lens arm 31
The S-WIDE switching end face cam 9a placed at a position close to the contact point abuts against the action pin 33 on the converter lens arm 31, and the converter lens arm 31 is pivoted against the urging force of the tension spring 34. It will be rotated clockwise about 32 (in FIG. 3).

Therefore, the converter lens arm 31 which has been placed in the retracted posture shown in FIG. 3 until now also largely rotates in the clockwise direction (in FIG. 3) from the retracted posture. When the second-group moving frame 9 further rotates and advances straight, the S-WIDE switching end face cam 9a contacts the pin surface near the tip of the action pin 33, causing the action pin 33 to rotate as shown in FIG. It will be held dynamically in the moving position.

Therefore, the converter lens arm 31 is
When the zoom lens reaches the working position on the optical axis O and stops at that position, the converter lens Lc is inserted at a predetermined working position at this point and is at a suitable position for realizing the focal length f _W of the WIDE end. The focal length f _SW of S-WIDE is realized in cooperation with the optical systems L _{1 to} L ₄ . In this case, in the illustrated embodiment, the second-group moving frame 9 and the third-group moving frame 9 are arranged so that the S-WIDE switching end face cam 9a and the action pin 33 on the converter lens arm 31 have such a relationship. The relative movement with respect to 7 and the rotation amount are set.

When the converter lens Lc is inserted in a predetermined operating position, its state is detected by using an appropriate attitude control means, for example, an electric attitude detection means,
The zoom motor is configured to be S-WIDE by being configured to introduce this electrical detection information into the integrated control circuit means.
It should be configured in advance so as to be stopped at a position or phase corresponding to the position where the focal length f _SW is realized.

[Operation or Action when the Lens Barrel is Stored] As described above, in the present invention, when the lens barrel is not in use, the lens barrel is at the shortest position as the fourth state length. It is configured so that it can be stored up to.
In this case, in the illustrated embodiment, each lens group (zoom optical system) L _{1 to} L ₄ is further placed in a state where the focal length f _SW of S-WIDE is realized (third state length),
The operation is performed by operating the seesaw type zooming operation member in the forward direction.

That is, when the zoom motor rotates in the forward direction by operating the seesaw type zooming operation member in the forward direction, the position in the sectional view drawn above the center line of FIG. 2 (focal length f _{SW of} S-WIDE until now). The main moving frame 2 which has been stopped at the position 2) is driven by the drive gear 21 and its own gear portion 2b.
The guide ring 5 and the connecting ring 10 move to the right while being further rotated by the screwing action with
And are moved straight to the right, and further, the cam frame 6 is moved to the right while rotating integrally with the main moving frame 2.

In the illustrated embodiment, the main moving frame 2 is
When the drive gear 21 reaches one end (end on the object side) of the length of the gear portion 2b of the main moving frame 2 in the optical axis direction, the movement to the right is stopped. Frame 2 is S-WID
While extending from the focal length (corresponding to the third state length) of the f _SW position of E in this position, the moving frame 3 and 8 of the first group and 4 groups, each mobile within the zooming area f _T ~f _W When moving the frames 3 and 8, and from the position where the focal length f _W of the WIDE end is realized, the focal length f of the S-WIDE
Each lens group moving frame 3 and 8 up to the position to realize _SW
While the movement is continued according to the same principle (procedure) as in the case of the movement, the moving frames 9 and 7 of the second group and the third group are
From the position that realizes the focal length f _W at the DE end to S-WIDE
Contrary to the case where the lens group moving frames 9 and 7 are moved to the position where the focal length f _SW is realized, the movement is continued so as to be relatively separated.

In this case, in the illustrated embodiment, 3 of the cam frame 6 is used.
The cam shapes of the group moving cam groove 6a and the fourth group moving cam groove 6b and the second group moving cam groove 7b of the third group moving frame 7 are S-WID from the position of the focal length f _W at the WIDE end described above.
When moving to the position of focal length f _SW of E, and when S-WI
From the position where the focal length f _{SW of} DE is realized to the film surface F
Since the cam state is set so that the relative position in the opposite direction is generated in the area (range) in the direction toward
Of the lens groups L _{1 to} L ₄ , the first and fourth lens groups L ₁ and L ₄ move to the right until the main moving frame 2 stops without changing their relative positions, and The second and third lens groups L ₂ and L ₃ will move to the right until the main moving frame 2 stops so that the relative positions of them gradually separate.

Then, when the main moving frame 2 is stopped, the movement of each moving frame 3, 7 to 9 to the right is stopped. That is, it stops at the position of the cross-sectional view drawn below the center line of FIG. 2, and this position becomes the stored state position corresponding to the fourth state length of this lens barrel.

In the illustrated embodiment, the end face cam 9a for S-WIDE switching is provided with the action pin 33 on the converter lens arm 31 from the position where the focal length f _SW of S-WIDE is realized to the housed position. Of the end surface cam 9a and the relative distance between the second-group moving frame 9 and the third-group moving frame 7 so that the converter lens arm 31 can be returned to the retracted position (from the pressed state). 7) is set. As a result, the converter lens Lc
Can be set outside the optical axis and can be set at a position where there is no interference with other lens groups, and the overall size of the lens barrel can be further reduced.

Further, in the illustrated example, the zoom motor is preliminarily configured to stop the rotational drive at the position where the drive gear 21 reaches one end of the gear portion 2b of the main moving frame 2 in the optical axis direction length. However, it is also possible to configure so that the zoom motor 21 is stopped before reaching the one end of the gear portion 2b of the main moving frame 2 in the optical axis direction length.

[Operation or Action when Switching from Zooming Regions f _{T to} f _W to Focal Length f _{TM in} Macro] In the illustrated embodiment, normal zooming regions f _{T to} f _{W are used.}
It is so constructed that an ultra-long focal length (focal length in macro) f _TM , which cannot be obtained by zooming in, can be obtained. In this case, in the illustrated embodiment, each lens unit (zoom optical system) L _{1 to} L _{4 is set} to the focal length f at the TELE end.
It is configured to be operated by operating the seesaw type zooming operation member in the opposite direction in a state where it is placed at a position where _T is realized.

However, each lens group (zoom optical system) L ₁
The principle or the point about the movement of L ₄ is that the rotation direction of the zoom motor changes from the forward direction to the reverse direction, and the movement direction of the main moving frame 2 changes from the right direction to the left direction (field direction). Since this is the same as the operation or action when the lens barrel is stored, detailed description thereof will be omitted in order to avoid complexity of the description.

In the illustrated embodiment, the three moving cam grooves 7b and 6 for controlling the movement of the respective lens group moving frames 3 and 7-9.
The shapes of a and 6b are such that the insertion rollers 12, 13 and 14 which are the objects to be moved in the respective cam grooves have the focal length f in the macro state.
From the position _{where TM} is obtained zooming area f _T ~f to a position where the focal length f _SW of the focal length is obtained position and S-WIDE is obtained accommodated state of the lens barrel via the position obtained in the _W, continuous It is configured so that it can be moved to. In the illustrated embodiment, as described above, the relative rotation angle between the second-group moving frame 9 and the third-group moving frame 7 is set as follows.

(B) Second group moving frame 9 and third group moving frame 7
When and are relatively rotating within the range of zooming regions f _{T to} f _W , it is set so that the end face cam 9a for S-WIDE switching and the action pin 33 do not come into contact with each other.

(B) Second group moving frame 9 and third group moving frame 7
And S-WIDE from the position of the focal length f _W at the WIDE end
When the relative rotation reaches the position of the focal length f _SW of, the S-WIDE switching end face cam 9a and the action pin 33 come into contact with each other during the relative rotation to move the converter lens arm 31 from the retracted position to the action position. It is set so that the action pin 33 can be held at the S-WIDE switching end face cam 9a while being rotated.

(C) Moving frame 9 for second group and moving frame 7 for third group
When and rotate relative to each other from the position of the focal length f _SW of S-WIDE to the housed position, the S-WIDE switching end face cam 9a opens the action pin 33 on the converter lens arm 31 during the relative rotation. It is set to do so.

Although a plurality of embodiments have been described above,
The present invention is not limited to these and can be variously modified and implemented without departing from the gist thereof. For example, in the illustrated embodiment, the retracted state position of the lens barrel is set on the extension of the position beyond the focal length f _SW of S-WIDE, but it exceeds the position of the focal length f _{TM in} the macro state. It is also possible to configure to set on extension.

Further, the structure for moving each lens group moving frame along the optical axis is not limited to the structure of the illustrated embodiment, and an appropriate structure known per se can be used. Is. Also, the focusing system and structure are not limited to those of the illustrated embodiment. Further, the shooting screen frame can be changed from the standard screen screen frame to a so-called panoramic screen screen frame in conjunction with the switching operation of the converter lens Lc from the retracted position to the working position. .

That is, with respect to the standard screen screen frame formed on the camera body, the shield plate that symmetrically shields the upper and lower parts of the standard screen screen frame to form the panoramic screen screen frame is slidable or rotatable. In addition, the standard screen frame is provided such that it can move back and forth between the retracted position and the approached position.

Then, the operation of inserting the converter lens Lc into the system of the zoom optical system, that is, the rotation operation of the converter lens arm 31 is transmitted to the shielding member via the member transmitting to the camera main body side. The screen member for the panoramic screen may be formed by rotating or sliding the screen member to enter the screen member from the retracted position into the upper part and the lower part of the screen frame for the standard screen. With this configuration, it is possible to take a magnificent and powerful photograph with an ultra-wide angle of view and an ultra-horizontal screen size, and greatly increase its practical value.

[0105]

As described above, according to the present invention of claim 1, one lens group driving means for relatively moving a plurality of lens groups is provided, and the lens group driving means moves the lens group driving means. When the lens group driving means is rotated in a predetermined direction, the plurality of lens groups are rotated with respect to at least one rotation-moving lens group that moves on the optical axis while rotating around the optical axis. The lens group is divided into a straight-moving lens group that moves straight along the optical axis, and when realizing a specific focal length that cannot be obtained within the normal zooming range of the zoom optical system, the lens group By using the operation of the lens group drive means set on the extension of the operation for realizing the focal length in the zooming area of the drive means, the linear movement and rotation relative to each other are performed between the rotational movement lens group and the linear movement lens group. Cause exercise So, since it is configured so as to obtain a specific focal length for the purpose of converter lens by the relative rotational translatory movement is inserted into a predetermined position of the zoom optical system,
It is possible to provide a lens barrel having a built-in converter lens that exhibits the following various effects.

(I) As a driving force for inserting / removing the converter lens, the driving force of the electric motor for driving each moving lens group constituting the zoom optical system is used as it is without using a dedicated electric driving means. Can be used.

(Ii) It is not necessary to particularly provide a complicated electric control means for inserting / removing the converter lens.

(Iii) As a mechanical movement means for inserting / removing the converter lens, a mechanical member included in an ordinary zoom lens is used as much as possible, and a slight unique member is added to the structure. The structure can be simplified and the cost can be reduced. Moreover, a structure having few intermediate parts and being robust and having high positional accuracy can be obtained.

(Iv) It is not necessary to increase the diameter and length of the lens barrel. In particular, when the insertion / removal position of the converter lens is set to the intermediate position of the zoom optical system, the area of the effective light flux becomes the smallest, so that there is an advantage that the converter lens can be made compact. Since a shutter is provided in the device, there is a so-called dead space for fully opening the shutter blade. Therefore, a converter lens and its insertion / removal mechanism can be provided in this space to effectively utilize the dead space. it can.

(V) When a specific focal length is realized and the lens barrel length is shortened, a dedicated operating member is not provided,
Moreover, the specific focal length can be realized by an operation that is continuous with the normal zooming operation. Further, the invention according to claim 9 is configured such that the converter lens is retracted to the outside of the optical axis in the housed state, so the converter lens capable of shortening the lens barrel length of the lens barrel when not in use is incorporated. A lens barrel can be provided.

[Brief description of drawings]

FIG. 1 is one of cross-sectional views of a lens barrel incorporating a converter lens according to the present invention. What is drawn above a center line (which is also an optical axis O) is that a zoom optical system has a long focal length ( FIG. 6 is a cross-sectional view of the lens barrel when in the TELE state, and what is drawn below the center line is a cross-sectional view of the lens barrel when the zoom optical system is in the short focal length (WIDE) state. Is.

FIG. 2 is another cross-sectional view of a lens barrel incorporating a converter lens according to the present invention. What is drawn above the center line is that the zoom optical system can be obtained within its own zooming region. FIG. 5 is a cross-sectional view of the lens barrel in a state of no ultra-short focal length (S-WIDE). What is drawn below the center line is the lens barrel in the stored state (state when not in use). FIG.

FIG. 3 is a diagram for explaining a state when the converter lens is at the retracted position.

FIG. 4 is a diagram showing a state in which a converter lens is in a retracted position.

FIG. 5 is a perspective view showing a state where the converter lens is being inserted from the retracted position to the working position.

FIG. 6 is a diagram showing a state in which a converter lens is inserted in a working position in a zoom optical system.

FIG. 7 is a diagram showing four lens groups L ₁ to L constituting a zoom optical system.
Relative motion trajectories when zooming L ₄ is a zooming operation diagram illustrating the relationship between the moment of the focal length.

FIG. 8 is a development view showing the shape and arrangement of male helicoid screws, gears, and lead grooves formed on the outer peripheral surface of the main moving frame.

FIG. 9 is a development view showing the shapes and arrangement relationships of the third-group moving cam groove, the fourth-group moving cam groove, and the arc-direction straight-moving groove formed in the peripheral wall portion of the cam frame.

FIG. 10 is a development view showing a shape and a positional relationship of a second-group moving cam groove formed in a peripheral wall portion of a third-group moving frame.

FIG. 11 is a rear view showing the gear train means from the output gear of the focus motor to the final stage gear meshing with the focus ring inner gear portion. is there.

[Explanation of symbols]

L _{1 to} L ₄ zoom optical system f _{T to} f _W zooming area f _T long focal length (focal length at TELE end) f _W short focal length (focal length at WIDE end) f _TM super long focal length (focal length during macro) Distance _SW f Ultra short focal length (specific focal length, S-WIDE
Focal length) O Optical axis Lc Converter lens F Film surface S Shutter unit S'Shutter blade also used as diaphragm 1 Fixing ring 1a Female helicoid screw 1b Straight guide groove 1c Notch 2 Main moving frame 2a Male helicoid screw 2b Gear 2c Lead Groove 2d Connection groove 2e Inner flange 3 Sub-moving frame (1st group moving frame) 3a Key groove 4 Engaging piece 5 Guide ring 5a Key portion 5b Arc direction groove 5c, 5d, 6c Straight groove 5e Flange portion 6 Cam frame 6a 3 group moving cam groove 6b 4 group moving cam groove 7 3 group moving frame 7b 2 group moving cam groove 8 4 group moving frame 8a Inner flange portion 8b Cylindrical portion 8c Straight groove 8d Leg portion 8e Space portion 9 Second group moving frame 9a End face cam 10 Connecting ring 10a Connecting protrusion 11,17 Connecting pin 12,13,14 Fitting roller 15 Focusing 15a Focusing cam groove 15b Inner gear portion 16 4th group lens group holding frame 18 1st group lens group holding frame 19 2nd group lens group holding frame 20 3rd group lens group holding frame 21 Drive gear 22 Support shaft 23 Stop ring 24 Focus motor 25 Output gear 26 Reduction gear train 27 Small gear at final stage 28 Storage space portion 30 Base plate of shutter unit S 30a Luminous flux transmission hole 31 Converter lens arm 31a Frame body 31b Rise portion 32 Axis 33 Action pin 34 Tension spring

Claims (9)

[Claims] 1. Zooming of a zoom optical system by removably inserting a converter lens into a system of a zoom optical system in which a plurality of lens groups move relatively on an optical axis to change a focal length. In a lens barrel incorporating a variable power optical system that realizes a specific focal length that cannot be obtained in a region, one lens group driving means provided in the lens barrel or an apparatus equipped with the lens barrel By operating the lens group driving means in a reciprocating direction, the plurality of lens groups can be moved relative to each other. When rotated, at least one rotation-moving lens group that moves on the optical axis while rotating around the optical axis and the lens group driving means do not rotate when rotated in a predetermined direction. And a linear movement lens group that linearly moves on the optical axis, and the length of the lens barrel is the first state length when in the longest state, and the first state length from the first state length. The second state length when shortened by the length corresponding to the zooming area of the zoom optical system, the third state length when further shortened from the second state length, and the shortest state The length of the lens barrel is sequentially set from the first state length to the fourth state length by rotating the driving means in a predetermined direction while setting each of the four states to the fourth state length. And the relative relationship positions of the plurality of lens groups are adjusted so that when the lens barrel is in the first state length, the plurality of lens groups are zoomed by the zoom optical system. The focal length at one end of the area When the lens barrel is in the second state length so that the obtained relative relationship position is obtained, the plurality of lens groups have a relative relationship in which the focal length of the other end of the zooming region of the zoom optical system is obtained. Between the rotational movement lens group and the rectilinear movement lens group, except for the step of shifting the lens barrel to the first state length and the second state length. By using the relative rectilinear and rotational movements generated in the, it is possible to insert the converter lens previously placed in the retracted position in the lens barrel to the working position in the zoom optical system, When the converter lens is inserted into the zoom optical system, the relative position of the two is determined by the combined focal length of the inserted converter lens and the plurality of lens groups. A lens barrel having a built-in converter lens, wherein the lens barrel is set so as to have a relative relationship position where the specific focal length can be obtained. 2. A lens barrel including the converter lens according to claim 1, wherein a focal length at one end of a zooming region of the zoom optical system is set as a longest focal length that can be realized by the zoom optical system. However, the focal length at the other end of the zooming area of the zoom optical system is set as the shortest focal length that can be realized by the zoom optical system, and it is realized with a combined focal length of the converter lens and the plurality of lens groups. A lens barrel having a built-in converter lens, wherein the specific focal length is set as a focal length having a value shorter than a shortest focal length that can be realized by the zoom optical system. 3. A lens barrel having the converter lens according to claim 1 or 2 built therein, wherein the converter lens previously placed in a retracted position in the lens barrel has a predetermined function in the zoom optical system. A lens barrel having a built-in converter lens, characterized in that it can be inserted by rotational movement in a plane orthogonal to the optical axis when it is inserted into a position. 4. A lens barrel including the converter lens according to claim 1, wherein the frame holding the converter lens faces a linear movement lens that faces the rotation movement lens group. A lens barrel having a built-in converter lens, which is rotatably supported by a pivot provided on a main plate of a shutter unit fixedly attached to a frame holding a group. 5. A lens barrel including the converter lens according to claim 4, wherein an end surface cam formed on a cylindrical end surface of a holding frame of the rotational movement lens group is used to move the rotational movement lens group and the linear movement. A configuration in which a frame body holding the converter lens is rotationally moved in a plane orthogonal to the optical axis with the pivot axis as an axis at a relative distance of a predetermined value or less with a moving lens group and a relative rotation angle of a predetermined value or more. A lens barrel with a built-in converter lens. 6. A lens barrel incorporating the converter lens according to claim 1, wherein one lens barrel is provided inside the lens barrel or inside a device equipped with the lens barrel. By operating the lens group driving means in the reciprocating direction, a plurality of lens groups can be relatively moved, and by operating the lens group driving means in a fixed direction, the zoom optical system can be improved. The plurality of lens groups that are configured are configured so that they can be made closer than the relative distance on the optical axis when the specific focal length is realized, and the length of the lens barrel at this time when not in use A lens barrel having a built-in converter lens, which is configured to be set as a storage length of the lens barrel. 7. A lens barrel including the converter lens according to claim 6, wherein the lens group closest to the film surface among the plurality of lens groups is configured as a focusing lens group, and the focusing lens group is used for focusing. Focusing driving means for driving the lens group is provided in the lens barrel, and the lens barrel is not used in a frame body that holds the lens group located on the object side facing the focusing lens group. A lens barrel having a built-in converter lens, which is configured to form a space for accommodating a member related to the focusing drive means when the housing length is shortened. 8. A lens barrel having a built-in converter lens according to claim 1, wherein a panoramic screen is formed by shielding a standard screen screen frame formed on the camera body from above and below. A shield plate forming a screen frame for the standard screen is provided so as to be able to move forward and backward with respect to the screen frame for the standard screen, and the shield plate is moved from the retracted position to the standard position in conjunction with the operation of inserting the converter lens into the system of the zoom optical system. A lens barrel having a built-in converter lens, which is configured to enter the screen frame for a screen to form the screen frame for a panoramic screen. 9. A lens barrel including the converter lens according to claim 1, wherein the converter lens is retracted out of the optical axis when the lens group is moved to a storage position. A lens barrel having a built-in converter lens, which is configured to shorten the storage length of the lens barrel when not in use.