JP3416317B2 - Lens barrel and optical equipment using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel and an optical apparatus using the same, and more particularly to fixing or moving a first lens unit on the object side during image pickup of an object or observation of an object image with an observation system. In a lens barrel that houses a shooting lens such as a zoom lens or a fixed focal length lens, the overall size of the lens barrel is reduced when not shooting except when shooting, such as a video camera with excellent portability. It is suitable.

[0002]

2. Description of the Related Art Conventionally, in optical equipment such as video cameras, various so-called front lens fixed type zoom lenses in which a first lens unit on the object side is fixed at the time of photographing, for example, during zooming or focusing, have been widely used. It is used. In many cases, in the lens barrel that holds the fixed front lens type zoom lens, the first holding frame that holds the first lens group is fixed to the fixing member (fixed barrel). Therefore, the total length of the lens barrel was always constant during shooting and non-shooting.

FIG. 13 is a sectional view of a main part of a conventional fixed lens barrel of a front lens. In the figure, 101 is a fixing member having an image pickup element (not shown). A third holding frame 102 holds the afocal lens (third lens group) L3, and is fixed to the fixing member 101. Reference numeral 103 denotes a fourth holding frame that holds the relay lens L3, and the fixing member 101
And the bar 10 and the bar 10 fixed by the third holding frame 102.
It is held by 5 so as to be movable in the optical axis direction. The fourth holding frame 103 is moved in the optical axis direction by the driving force from the driving motor 106 via the feed screw. 1
A first holding frame 07 holds the first lens unit L1.
It is fixed to the fixing member 101 with screws 108.

Reference numeral 109 is a second lens holding the second lens unit L2.
It is a holding frame, and is held so as to be movable in the optical axis direction by a bar 110 and a bar 111 fixed between the first holding frame 107 and the fixing member 101. Second holding frame 1
09 is moved in the optical axis direction via the feed screw by the driving force from the drive motor 112.

[0005]

In the lens barrel for holding the fixed front lens type zoom lens shown in FIG. 13, the first holding frame 107 is fixed to the fixing member 101. Therefore, the entire length of the lens barrel is always constant during shooting and non-shooting, and the first lens group is in a state of protruding toward the object side during non-shooting.

Recently, various camera-integrated video cameras equipped with a liquid crystal monitor have a structure in which the entire camera is shortened in the optical axis direction of the taking lens. When a photographing lens having a lens barrel which is long in the optical axis direction as shown in FIG. 13 is used in such a video camera, only the photographing lens of the entire camera is projected in the optical axis direction even when not photographing, There was a problem that portability was not good.

Such a problem is not limited to the taking lens in which the first lens group is fixed at the time of photographing, and is the same in the taking lens in which the first lens group moves on the optical axis during zooming and / or focusing. It was

According to the present invention, in an optical device equipped with a lens barrel for accommodating a photographing lens in which the first lens unit on the object side is fixed or moved at the time of photographing, by appropriately setting the configuration of the lens barrel. It is an object of the present invention to provide a lens barrel suitable for a camera-integrated video camera, etc., which has improved portability, and an optical device using the same in order to reduce the size of the entire optical device when not shooting.

In particular, the present invention relates to a lens barrel having a retractable structure in which a lens barrel for holding a lens unit on the object side is appropriately set so that the total lens length is shortened during non-photographing and an optical apparatus using the same. For the purpose of provision.

Incidentally, the time other than the time when the photographing operation of the photographing lens and the observation operation are not performed (when the photographing is not performed) is also referred to as the "during storage".

[0011]

A lens barrel according to a first aspect of the present invention comprises a fixed barrel having a fixed cam engaging portion, and a first lens group provided on the fixed barrel so as to be able to move straight in the optical axis direction. The first lens holding frame held and the second lens holding second lens group
A lens holding frame, a first cam that is rotatably provided inside the first lens holding frame and that engages with the fixed cam engaging portion, and a second lens holding frame for moving in the optical axis direction. A cam ring having a second cam, and by rotating the cam ring to move in the optical axis direction, the first lens holding frame and the second lens holding frame are brought into a stored state and a photographing state. In the lens barrel that moves in the optical axis direction, the first cam of the cam ring includes the first lens holding frame and the cam ring from the stored state to the shooting state.
The integrally optical axis direction, Repetitive together when the cam ring is rotated
Between the first cam area protruding and the shooting state, the first cam area
A second cam region for fixing the lens holding frame in the optical axis direction, wherein the second cam of the cam ring rotates from the stored state to the photographing state. The second lens holding frame is moved in the optical axis direction during the shooting state and the first cam region in which the relative position of the cam ring and the second lens holding frame does not change while being extended along with the optical axis direction. And a second cam region that causes the second cam region to move.

A lens barrel according to a second aspect of the present invention includes a fixed barrel having a fixed cam engaging portion, and a first lens holder that holds the first lens group that is provided on the fixed barrel so as to be able to move straight in the optical axis direction. A frame and a second lens holding frame holding the second lens group;
A first cam that is rotatably provided inside the first lens holding frame and that engages with the fixed cam engagement portion; and a second cam that moves the second lens holding frame in the optical axis direction. And a cam ring having a cam ring, and the first lens holding frame and the second lens holding frame are moved in the optical axis direction between a stored state and a photographing state by rotating the cam ring and moving the cam ring in the optical axis direction. In the lens barrel, the first of the cam rings is
The cam of the, from the stored state to the shooting state,
The first lens holding frame and the cam ring are integrally formed in the optical axis direction.
Countercurrent, when the cam ring is rotated and the first cam region for feeding out together during the shooting state, the second cam region to move together to the optical axis and the cam ring and the first lens holding frame The second cam of the cam ring and the second cam of the cam ring rotate while the cam ring rotates and is extended in the optical axis direction from the stored state to the photographing state.
The first cam area in which the relative position with respect to the lens holding frame does not change, and during the shooting state, while the cam ring rotates, the second lens holding amount is different from the moving amount of the first lens holding frame. And a second cam region for moving the frame in the optical axis direction.

In the lens barrel of the third aspect of the invention, a fixed barrel, a first lens holding frame for holding the first lens group, which is provided on the fixed barrel so as to be able to move straight in the optical axis direction, and an optical member for the fixed barrel. A second lens holding frame, which holds the second lens group, is provided so as to be able to move straight in the axial direction, and a first lens holding frame, which is provided inside the fixed cylinder and is rotatable in a fixed position, for moving in the optical axis direction. A cam ring having a first cam and a second cam for moving the second lens holding frame in the optical axis direction,
In the lens barrel for moving the first lens holding frame and the second lens holding frame in the optical axis direction between the stored state and the shooting state by rotating the cam ring, the first cam of the cam ring is provided. Is a first cam region that extends the first lens holding frame in the optical axis direction from the stored state to the shooting state, and fixes the first lens holding frame in the optical axis direction during the shooting state. The second cam area of the cam ring, and the second cam of the cam ring holds the second lens holding frame in the optical axis direction from the stored state to the shooting state. It is characterized in that it has a first cam region and a second cam region for moving the second lens holding frame in the optical axis direction during the photographing state.

According to a fourth aspect of the invention, in the first, second or third aspect of the invention, the first lens group is the lens group closest to the object side, and the second lens group is in the optical axis direction during zooming. It is characterized by a moving lens group. According to a fifth aspect of the invention, in the first, second or third aspect of the invention, the first cam and the second cam of the cam ring are separate cams. According to a sixth aspect of the invention, in the first or third aspect of the invention, the first cam and the second cam of the cam ring are common cams.

According to another aspect of the optical apparatus of the present invention, a fixed barrel having a fixed cam engaging portion, and a first lens holding frame for holding the first lens group which is provided on the fixed barrel so as to be able to move straight in the optical axis direction. A second lens holding frame that holds a second lens group; a first cam that is rotatably provided inside the first lens holding frame and that engages with the fixed cam engagement portion; and the second lens A cam ring having a second cam for moving the holding frame in the optical axis direction, and rotating the cam ring to move in the optical axis direction, the first lens holding frame and the second lens holding frame.
In an optical device having a lens barrel for moving a lens holding frame in an optical axis direction between a housed state and a photographing state, the first cam of the cam ring is an optical device for capturing an object image from the lens barrel. , The first lens holding frame and the cam ring are integrally formed in the optical axis direction from the stored state to the shooting state.
A, has a first cam region for feeding both the said cam ring rotates, during the photographing state, and a second cam region for the fixed state the first lens holding frame in the optical axis direction, the cam The second cam of the ring changes the relative position between the cam ring and the second lens holding frame while the cam ring rotates and extends in the optical axis direction from the stored state to the photographing state. A second cam for moving the second lens holding frame in the optical axis direction between the first cam area and the shooting state.
And a cam area.

According to an eighth aspect of the present invention, there is provided an optical device comprising: a fixed barrel having a fixed cam engagement portion; and a first lens holding frame which is provided on the fixed barrel so as to be able to move straight in the optical axis direction and which holds a first lens group. A second lens holding frame that holds a second lens group; a first cam that is rotatably provided inside the first lens holding frame and that engages with the fixed cam engagement portion; and the second lens A cam ring having a second cam for moving the holding frame in the optical axis direction, and rotating the cam ring to move in the optical axis direction, the first lens holding frame and the second lens holding frame.
In an optical device having a lens barrel for moving a lens holding frame in an optical axis direction between a housed state and a photographing state, the first cam of the cam ring is an optical device for capturing an object image from the lens barrel. , The first lens holding frame and the cam ring are integrally formed in the optical axis direction from the stored state to the shooting state.
In a first cam region for feeding both the said cam ring rotates, said during the shooting state, the second cam region to move together to the optical axis and the cam ring and the first lens holding frame The second cam of the cam ring has the cam ring and the second lens holding frame while the cam ring rotates and is extended in the optical axis direction from the stored state to the photographing state. And a second cam with a movement amount different from the movement amount of the first lens holding frame in the optical axis direction while the cam ring rotates during the photographing state and the first cam region where the relative position of the first lens does not change. And a second cam region for moving the holding frame in the optical axis direction.

An optical apparatus according to a ninth aspect of the present invention comprises a fixed barrel,
A first lens holding frame holding a first lens group, which is provided in the fixed barrel so as to be able to move straight in the optical axis direction, a second lens holding frame holding a second lens group, and a fixed position rotation inside the fixed barrel. A cam ring that is freely provided and has a first cam for moving the first lens holding frame in the optical axis direction and a second cam for moving the second lens holding frame in the optical axis direction. A lens barrel for moving the first lens holding frame and the second lens holding frame in the optical axis direction between the stored state and the photographing state by rotating the cam ring, In the optical device for picking up the object image, the first cam of the cam ring has a first cam region that extends the first lens holding frame in the optical axis direction from the stored state to the shooting state. During the shooting state, the first
A second cam region for fixing the lens holding frame in the optical axis direction, wherein the second cam of the cam ring holds the second lens holding frame from the stored state to the photographing state. Is fixed in the optical axis direction, and a second cam area for moving the second lens holding frame in the optical axis direction during the photographing state.

According to a tenth aspect of the invention, in the seventh, eighth or ninth aspect of the invention, the first lens group is the lens group closest to the object side, and the second lens group is in the optical axis direction during zooming. It is characterized by a moving lens group. Claim 1
The invention of claim 1 is the invention of claim 7, 8 or 9 characterized in that the first cam and the second cam of the cam ring are separate cams. The invention of claim 12 is the invention of claim 7, 8 or 9, wherein the first of the cam rings is
The first cam and the second cam are common cams.

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

1 and 2 are sectional views of the essential portions of Embodiment 1 of the present invention. FIG. 1 shows a state in which the lens barrel is stored, and FIG. 2 shows a state in which the lens barrel is not stored. FIG. 3 is an explanatory view of a part of FIG.

In the figure, 1 is a first lens group which is fixed at the time of photographing (magnification and focusing and observation of an object), 2 is a second lens group for magnification change, and 3 is a third lens group which is fixed at the time of photographing. Reference numeral 4 denotes a fourth lens group that moves on the optical axis for correcting the image plane variation due to zooming and during focusing.

A front lens frame (first holding frame) 5 holds the first lens group 1. 6 is a cam ring, which is a front lens frame 5
It is rotating inside. Reference numeral 7 denotes a cam ring inner gear, which is provided inside the cam ring 6. Reference numeral 11 denotes a straight-movement key portion for the front lens frame, which is provided integrally with the frame 8 which also serves as a retainer from the rear in the thrust direction of the cam ring 6. 9 is a straight groove for the second group frame, which is formed in the front lens frame 5. 10 is a straight groove for the front lens frame, which is provided in the fixed cylinder 15.

Reference numeral 16 is a stepping motor for driving the fourth lens, 17 is a zooming motor for driving when retracting and changing the magnification,
Reference numeral 18 denotes an interlocking gear, which meshes with the cam ring inner gear 7. An output shaft 19 transmits the driving force from the zoom motor 17. Reference numeral 12 is a fixed cam roller, which is a fixed cylinder 15.
And is engaged with a cam groove 32 provided in the cam ring 6.

In this embodiment, three or more fixed cam rollers and three
The cam grooves of the book are arranged every 120 degrees when viewed from the front of the lens barrel to prevent the first lens group 1 from tilting and decentering. In the figure, only one place is shown. Reference numeral 13 denotes a second group cam roller, which is integrally provided with a second group moving frame (second holding frame) 14, engages with a cam hole provided in the cam ring 6, and further has a tip end thereof for a second group frame straight advance. It is engaged with the groove 9. In the second group moving frame 14, three or more second group cam rollers 13 and three cam grooves are arranged every 120 degrees when viewed from the front of the lens barrel,
The tilt decentering of the second lens group 2 is prevented. In the figure, only one place is shown.

Reference numeral 20 is an arm portion integrally provided with the second-group moving frame 14. Reference numeral 21 denotes an output shaft of the step motor 16, which has a male thread on its outer peripheral portion. Reference numeral 22 is a rack member, and 23 is a rack spring, which generates a pressing force for pressing the rack teeth of the rack member 22 to the male screw portion of the output shaft 21. The rack 22 has no thrust and is attached to the fourth group moving frame (fourth holding frame) 30. Reference numeral 24 denotes a detent bar of the fourth lens group 4, reference numeral 25 denotes a guide bar for moving the fourth lens group 4, which is fitted with a sleeve integral with the fourth group moving frame 30 to make the fourth lens group 4 fall eccentric. Is being prevented.

A volume encoder unit 29 has a brush portion 28 and a connecting portion 27 which is integral with the brush portion 28, and these are connected to the arm portion 20. Brush part 2
8 moves in the left-right direction in the figure, the contact position on the resistor (not shown) changes, and the output value from the encoder 7 changes accordingly, and the optical axis of the second lens group 2 changes. The direction position is detected. Reference numeral 26 is a diaphragm portion.

In this embodiment, when the second group moving frame 14 is at the position of the solid line (tele end) as shown in FIG.
When the zoom motor 17 rotates in a predetermined direction, power is transmitted to the cam ring inner gear portion 7 via the output shaft 19 and the interlocking gear 18, and the cam ring 6 rotates in a predetermined direction. At this time, the fixed cam roller 12 is positioned in the region 32b where the cam groove 32 on the cam ring 6 does not have a cam lift (cam lift is 0) (FIG. 3 (D)), whereby the cam ring 6 rotates. The first lens group 1 does not move in the optical axis direction even if it moves.

On the other hand, the second group cam roller 13 is located in the area 31a provided with the cam lift of the cam groove 31 on the cam ring 6, so that the second lens group 2 is moved to the second group 2 as the cam ring 6 rotates. It is arranged to move on the optical axis to the position (wide end) indicated by the dotted line (FIG. 3 (C)). At this time, the volume encoder 29 detects the position of the second lens group 2 in the optical axis direction. The cam ring 6 is rotated in the thrust direction and the radial direction by the front lens frame 5 and the frame 8 while the fitting play is held below a predetermined amount.

At this time, the first lens group 1 is stationary without rotating due to the engagement of the straight-movement key 11 for the front lens frame 5 and the straight-movement groove 10, and the second-group cam roller 13 and the straight-movement for the second-group frame are straight forward. Due to the engagement of the groove 9, the second group moving frame 14 also moves straight without rotating.

In FIG. 2, the zoom motor 17 is further rotated in a predetermined direction from the position of the second-group moving frame 14 indicated by the chain double-dashed line in FIG. 1 (that is, from the time of shooting to the time of non-shooting). It shows a state in which the lens group 1 is retracted and brought into a stored state (non-photographing state). At this time, the relationship between the fixed cam roller 12 on the cam ring 6 and the second group cam roller 13 is shown in FIG.
(C), FIG. 3 (B), and FIG. 3 (A).

In this embodiment, in the process from the photographing state of FIG. 1 to the retracted state of FIG. 2, as shown in FIGS. 3C, 3B and 3A, the second group cam roller 13 for the second group moving frame 14 is provided. Moves the area 31b where the cam lift is zero.

As a result, the relative positional relationship between the first lens group 1 and the second lens group 2 becomes constant, and the cam ring 6 is rotated until the cam groove engaged with the fixed cam roller 12 has a predetermined cam lift. While retracting while moving the front lens frame 5 straight,
The storage state of FIG. 2 is reached.

Next, the cam ring 6 shown in FIGS.
The deployed state of the cam mechanism will be described. In the figure, the left-right direction indicates the rotation angle of the cam ring 6, and the up-down direction indicates the position in the optical axis direction. Further, as described above, both the first lens group 1 and the second lens group 2 are actually positioned using three or more cam portions for the purpose of removing the tilt eccentricity, but in FIG. Therefore, only one cam portion is shown in the figure.

FIG. 3A shows the housed state (corresponding to FIG. 2), and FIG. 3B shows the movement of the first lens group 1 and the second lens group 2 when moving from the housed state to the photographing state. The intermediate situation is shown. 3C shows a state in which the focal length of the taking lens is at the wide end (two-dot chain line in FIG. 1), and FIG. 3D shows a state at the tele end (solid line in FIG. 1). The intermediate focal length is taken in the intermediate situation between FIG. 3 (C) and FIG. 3 (D).

In FIG. 3, reference numeral 34 indicates the position of the optical axis on the focus plane, for example. A shows the fixed cam roller 12, and B shows the second group cam roller 13. Fixed cam rollers 12 and 2
Since the group cam roller 13 is engaged with the straight-moving key 11 and the second group frame straight-moving groove 9 as described above, FIGS.
In (D), the position in the left-right direction from the optical axis (relative distance)
Does not change.

The cam ring 6 is provided with a cam portion 32 for the front lens frame and a cam portion 31 for the second group moving frame, and each of the cam portions has a flat portion (0
The cam portions 31b and 32b and the portions having the cam lift (tilt cam portions) 31a and 32a are held together.

FIG. 3 (A) shows the state of storage and the focusing surface 3
The distance from 4 to the rear end 6a of the cam ring 6 is C, which is the shortest. Since the second group cam roller 13 has the cam lift 0 and is located at the deepest position of the flat portion 31b, even if the cam ring 6 rotates in the direction of the arrow 33 from this state, the cam ring 6 and the second lens group 2
Does not change relative positional relationship (that is, when the rotatable cam ring 6 in the front lens frame 5 is rotated in the direction of arrow 33,
The cam lift 32a moves the position of the cam ring 6 with respect to the fixed cam roller 12 in the optical axis direction away from the focus surface 34. When the cam ring 6 moves, the front lens frame 5 (first lens group 1) simultaneously moves in the optical axis direction by the same amount as the cam ring 6 moves. At this time, the second group cam roller 13 of the second lens group 2
Is located in the flat portion 31b of the cam ring 6,
The second lens group 2 moves in the optical axis direction by the same amount as the moving amount of the cam ring 6 as the cam ring 6 moves. Therefore, the relative positional relationship between the first lens group 1 and the second lens group 2 does not change).

On the other hand, since the fixed cam roller 12 is at the innermost part of the portion 32a having the cam lift, by rotating the cam ring 6 in the direction of the arrow 33, the cam ring 6 moves in the optical axis direction, and along with this, the front lens frame. 5 is fed (that is, when the rotatable cam ring 6 in the front lens frame 5 is rotated in the direction of the arrow 33, the position of the cam ring 6 with respect to the fixed cam roller 12 is changed from the focus surface 34 by the cam lift 32a. The front lens frame 5 is moved at the same time when the cam ring 6 is moved.
The (first lens group 1) moves in the optical axis direction by the same amount as the moving amount of the cam ring 6. At this time, since the second group cam roller 13 of the second lens group 2 is located on the flat portion 31b of the cam ring 6, the second lens group 2 moves the cam ring 6 along with the movement amount of the cam ring 6 in the optical axis direction. Move the same amount as. Therefore,
The first lens group 1 and the second lens group 2 are integrally extended).

FIG. 3B shows the focus position 3 in this intermediate situation.
The distance from 4 to the rear end 6a of the cam ring is B (B> C). When the cam ring 6 is further rotated in the direction of the arrow 33, FIG.
In the state of (C), the fixed cam roller 12 has the flat portion 3
2b, and conversely, the second group cam roller 13 is arranged at the entrance of the tilt cam portion 31a having a cam lift. At this time, the distance from the focusing surface 34 to the rear end portion 6a of the cam ring 6 is A (A> B). This state is the state of the chain double-dashed line in FIG. From here, when the cam ring 6 is further rotated in the direction of the arrow 33, the state shown in FIG.

As described above, according to the first embodiment of the present invention, the first cam group 6 and the single motor 17 retract the first lens group, which is fixed during zooming of the photographing state during storage.

In the first embodiment, when the second lens group 2 is zoomed while maintaining the relative positional relationship between the first lens group 1 and the second lens group 2 when the second lens group 2 is at the wide end. The first lens group 1 is retracted by the same amount as the stroke.

Generally, in order to reduce the size, the distance between the first lens group 1 and the second lens group 2 at the wide end is set to be the shortest distance within a range where mechanical collision does not occur even if various errors are taken into consideration.
Also, the aperture stop at the telephoto end and the second lens group are often designed to have the shortest distance.

In the present embodiment, the amount of movement of the second lens unit during zooming and the amount of collapse of the lens unit during storage are made the same, thereby obtaining the most efficient collapse effect. Therefore, in the cam mechanism of FIG. 3, the lift amounts of the cam portion 31 and the cam portion 32 are made equal to each other.

FIG. 4 is an explanatory diagram showing the loci of movement of the first, second, third and fourth lens groups constituting the zoom lens in this embodiment in the optical axis direction. 4 (A), (C),
The positions of the respective lens groups in (D) are shown in FIGS. 3 (A), (C),
Each corresponds to (D). 1, 2, 3, and 4 in FIG.
The first, second, third, and fourth lens groups are shown in FIG.
Shows the lens arrangement in the non-shooting state of FIG. 3 (A), FIG. 4 (C) shows the lens arrangement in the wide state of FIG. 3 (C), and FIG. The lens arrangement in the case of FIG. 3D in the tele state is shown. Here, when the cam ring 6 is rotated in the direction of arrow 33 in FIG.
The state of (A) is sequentially changed to the states of (B) and (C). The arrangement of the lenses is such that the first lens group 1 and the second lens group 2 move in the optical axis direction at equal intervals in the state of FIGS. Further, when the cam ring 6 is rotated in the direction of the arrow 33 from the state of FIG. 3 (C), the state of FIG. 3 (D) is obtained. At this time, the lens arrangement is changed from the state of FIG.
The lens group 1 does not move in the optical axis direction, but the second lens group 2 moves in the optical axis direction indicated by the arrow. The arrow of the fourth lens group 4 indicates the locus of movement so as to correct the image plane variation in accordance with the zoom movement of the second lens group 2.

Next, a second embodiment of the present invention will be described.
The second embodiment is the same as the rear focus type zoom lens, which is composed of four lens groups as a whole, as compared with the zoom lens of the first embodiment, but the first lens group is used when the magnification is changed from the wide-angle end to the telephoto end. The difference is that is moving to the object side.

FIG. 5 is an explanatory view showing the positions on the optical axis of each lens unit constituting the zoom lens of Embodiment 2 as in FIG.

FIG. 6 is an explanatory view showing a developed state of the cam mechanism of the cam ring 6 of the second embodiment, similar to FIG.

FIG. 5 (A) shows the stored state (the state of being collapsed), FIG. 5 (C) shows the state at the wide end, and FIG. 5 (D).
Indicates the state at the tele end. 6A is in the stored state (corresponding to FIG. 5A), FIG. 6B is an intermediate state from the stored state to the photographing state, and FIG. 6C is in the wide end state (FIG. 5C). )), And FIG. 6D shows the state at the telephoto end (corresponding to FIG. 5D).

As a difference from FIG. 3, the cam portion 32 for the front lens frame is provided with a region 32c having a predetermined cam lift by eliminating the region where the cam lift is 0. It is moving in the axial direction. At this time, the movement of the second lens group is caused by the cam portion 3 in the region 31a of FIGS.
It also corresponds to the difference between the lift of 1 and the lift of the cam portion 32.

Next, a third embodiment of the present invention will be described.
In the first and second embodiments, the cam ring 6 is provided with the front lens frame cam portion 32 and the second-group moving frame cam portion 31 independently.

On the other hand, in the present embodiment, the two cam portions are constituted by a common one cam portion to regulate the positions of the lens groups 1 and 2 in the optical axis direction. , 2 is different.

FIG. 7 is a development view of the cam mechanism of the cam portion 38 provided on the cam ring 6 when the same zoom lens as that of the first embodiment is used as the zoom lens in the present embodiment. 7A shows the state of storage, FIG. 7B shows the intermediate state of transition from storage to the shooting state, FIG. 7C shows the state of the wide end, and FIG. The state of the edge is shown.

The cam portion 38 uses a cam portion (first region) 35 and a cam portion (third region) 37 having a cam lift of 0 in common to regulate the positions of the first lens group and the second lens group (second portion).
The area 36 is extended to both ends. Cam part 35
The front lens frame 5 and the cam portion 37 are regions used independently for the position regulation of the second group moving frame 14. If the cam portion 35 is provided with a lift, it can be applied to a zoom lens similar to the second embodiment shown in FIG.

As described above, three or more cam portions are used to prevent the eccentricity of each movable lens group from collapsing. For example, in this figure, the cam portion is formed in the range of 120 degrees. The rotation angles of the cam ring 6 from the state of FIG. 7 (A) to the state of FIG. 7 (B), (C), (D) are θ _B , θ _C , and θ _D. The distance from the focus position 34 to the rear end portion 6a of the cam ring 6 is the distance C, B, in the order of FIG. 7 (A) → FIG. 7 (D) as in FIG.
A, A, and the distance A-distance C is the amount of collapse. By thus integrating the cam portions into one, the working process of the cam ring 6 is simplified, the strength is improved, and the cam accuracy is improved in accordance with the strength improvement.

FIG. 8 is a development explanatory view of the cam mechanism of the cam portion provided on the cam ring according to the present invention. This figure shows three cam portions 81a, 81b provided with one moving lens group on the cam ring 6,
It is a figure when the cam ring 6 in the case of positioning by 81c is expanded 360 degrees. FIG. 8A shows a cam ring applied to the third embodiment. FIG. 8B shows a cam ring applied to the first embodiment. As shown in the figure, the cam portion in FIG. 8 (A) need only be three in total, so that the machining process is simplified as compared with FIG. 8 (B). In FIG. 8A, since the cam ring 6 has a margin of extra thickness, the strength of the cam ring 6 is better than that in FIG. 8B.

In FIG. 8A, the manner of cam lift (cam gradient) can be made gentler than that in FIG. 8B. Therefore, for example, by laying a cam gradient near the tele that requires high speed for moving the focusing lens group on the trace of zoom tracking, it is possible to incorporate measures such as pressing the required maximum speed of the focusing lens group. Becomes

In the above description of the respective embodiments of the present invention, the state between the first lens group and the second lens group, which is the first from the subject side, is from the shooting state to the storage state (non-shooting state). Although the configuration for shortening the total lens length has been described, the present invention is not limited to this.

For example, in the zoom lens as shown in FIG. 4, the present invention is carried out between the third lens of the third group and the fourth lens of the fourth group from the subject side, and then the first lens. It is also possible to adopt a superposition structure in which the present case is implemented between the first lens group and the second second lens group.

According to this, the total length of the lens when stored can be further shortened. Even if the structure of the lens barrel of the present invention is not applied to shorten the total length of the lens, if the present invention is applied, the lens group is biased to a certain position inside the lens, so that a wide space can be secured. This space may be used, for example, as a retreat space for the movable parts in a unique state during non-shooting.

The cam in each embodiment of the present invention described above is
The cam cylinder provided on the cylindrical cylindrical cylinder has a cam hole and a cam groove, and the cam roller inserted by being fitted into the cam hole or the cam groove has an interlocking structure. A type in which a cam portion 38 having a convex cam is provided on the inner circumference of 6 may be used.

As shown in the left diagram of FIG. 9, reference numeral 38 is composed of the above-mentioned cam portions 35 and 37 of the cam lift 0 and the cam portion 36 having the cam lift in the range of B °. It is provided in 3 places. Second group moving frame 1 (not shown)
Reference numeral 4 denotes three cam follower parts which are pressed against the cams 38, and the cam follower parts are pressed against the cam parts by a pressing force obtained by a spring or the like from the direction of arrow 41, for example. Alternatively, the convex cam portion 38 may be sandwiched. or,
In order to connect to the rectilinear groove 9 shown in FIG. 1, it is provided side by side with the convex cam portion 38 and provided in the connecting groove portion 42.

Further, in this embodiment, in the shooting state shown in FIG. 2, a slight tilt of the front lens frame or the like due to mechanical rattling does not fall within the target range, and as a result, unacceptable deterioration of image performance such as one-sided blurring. It is conceivable that a fixed holding barrel for fitting and holding the outer diameter of the front lens frame 5 with the inner diameter is further provided on the outer appearance when it occurs.

As described above, in this embodiment, the position of the fixed cam roller 12 does not change in the optical axis direction as shown in FIGS. On the other hand, the cam ring 6 and the front lens frame 5 are arranged so as to be integrally rotatable in the thrust direction. On the other hand, the configurations shown in FIGS. 10 and 11 can also be applied.

The cam ring 6 hatched in the constructions of FIGS. 10 and 11 is fixed in the thrust direction and is rotatably assembled to the fixed cylinder 15 which is immovable in the thrust direction (actually, the cam ring is actually mounted. An inner gear portion (not shown) is provided on the inner circumference, and is rotated by a motor as in the example of FIGS. 1 and 2.

A cam similar to that shown in FIGS. 8A and 8B is provided on the cam ring 6. The second group moving frame 14 is provided with a cam roller 13 similar to that shown in FIGS. 1 and 2, and is fitted into the cam of the cam ring 6 and has a tip end thereof in a straight groove 9 provided in the fixed barrel 15.
Is fitted to. As a result, as in FIGS. 1 and 2, the second group moving frame 14 is movable in the optical axis direction at the portion where the cam lift is provided (cam 36 portion) by the rotation of the cam ring.

On the other hand, as a difference from FIG. 1 and FIG. 2, a cam roller portion 40 is provided integrally with the front lens frame 5 and similarly fitted to the cam on the cam ring, and its tip is provided on the fixed barrel 15. It also fits in the straight groove 9 '.

That is, in FIGS. 1 and 2, the cam roller is the fixed side and the cam (cam ring) is the movable side in the thrust direction, and therefore the cam ring and the front lens frame are integrated in the thrust direction. In the configuration of FIG. 11, the cam ring is the fixed side and the cam roller side is the movable side in the thrust direction. Therefore, the cam ring is integrated with the fixed cylinder in the thrust direction.

FIG. 10 shows a state of storage. Each lens group is located on the camera body side as shown in FIG. When the cam ring 6 rotates from that state, the first lens frame moves forward while the position of the second lens frame is fixed, and the shooting state at the tele end is reached. At this time, the state shown in FIG. If the cam ring is further rotated in the same direction from this position, the first
The second lens group moves forward while the lens group remains fixed, and zooming is performed from the tele end to the wide end. 12
(D) is in the wide end state. Although the configurations of FIGS. 10 and 11 are different from those of FIGS. 1 and 2 in the above, they do not depart from the gist of the present invention.

In the description of each embodiment of the present invention, the cam ring has been described above, but a similar cam is provided on the plate-shaped cam plate in which the cam ring is expanded, and the cam plate is slid to the left and right. It is possible to obtain a similar movement.

[0077]

As described above, according to the present invention, in the optical apparatus equipped with the lens barrel for housing the photographing lens in which the first lens unit on the object side is fixed or moved during photographing, By appropriately setting the configuration, the overall size of the optical device during non-shooting can be reduced, and for example, a lens barrel suitable for a camera-integrated video camera having improved portability and an optical device using the lens barrel can be achieved. be able to.

In particular, according to the present invention, the lens barrel for holding the lens unit on the object side has a retractable structure in which the lens barrel for holding the lens unit on the object side is appropriately set, thereby reducing the lens overall length during non-photographing and an optical system using the lens barrel. Equipment can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a first embodiment of the present invention at the time of shooting.

FIG. 2 is a cross-sectional view of essential parts of the first embodiment of the present invention during non-imaging

FIG. 3 is a development explanatory view of a cam mechanism of the cam ring of FIG.

FIG. 4 is a lens cross-sectional view of the zoom lens according to Embodiment 1 of the present invention.

FIG. 5 is a lens cross-sectional view of a zoom lens according to a second embodiment of the present invention.

FIG. 6 is a development explanatory diagram of a cam mechanism of a cam ring according to a second embodiment of the present invention.

FIG. 7 is a development explanatory diagram of a cam mechanism of a cam ring according to a third embodiment of the present invention.

FIG. 8 is a development explanatory view of a cam mechanism of a cam ring according to the present invention.

FIG. 9 is an explanatory view of another embodiment of the cam ring according to the present invention.

FIG. 10 is an explanatory view of another embodiment of the cam ring according to the present invention.

FIG. 11 is an explanatory view of another embodiment of the cam ring according to the present invention.

FIG. 12 is a lens cross-sectional view of a zoom lens corresponding to FIGS.

FIG. 13 is a side view of a main part of a lens barrel of a conventional zoom lens.

[Explanation of symbols]

5 Front lens frame (first holding frame) 6 cam ring 8 frames 9 2nd group frame straight groove 10 Straight groove for front lens frame 11 Straight key for front lens frame 12 fixed cam roller 13 2nd group cam roller 14 second group moving frame (second holding frame) 31, 32 Cam section

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02B ⁷ /02-7/105

Claims (12)

(57) [Claims] 1. A fixed barrel having a fixed cam engagement portion, a first lens holding frame that holds the first lens group and is provided on the fixed barrel so as to be able to move straight in the optical axis direction, and holds a second lens group. The second lens holding frame, the first cam that is rotatably provided inside the first lens holding frame and that engages with the fixed cam engaging portion, and the second lens holding frame moves in the optical axis direction. And a cam ring having a second cam for moving the first lens holding frame and the second lens holding frame by rotating the cam ring in the optical axis direction. In the lens barrel that moves in the optical axis direction depending on the state, the first cam of the cam ring is configured such that the first lens holding frame and the cam from the stored state to the shooting state.
A ring integral with the optical axis direction, when the cam ring rotates together
A first cam region for feeding, during the shooting state, and a second cam region for the fixed state the first lens holding frame in the optical axis direction, the second cam of the cam ring A first cam region where the relative position of the cam ring and the second lens holding frame does not change while the cam ring rotates and is extended in the optical axis direction from the stored state to the shooting state, A lens barrel having a second cam region for moving the second lens holding frame in the optical axis direction during the photographing state. 2. A fixed barrel having a fixed cam engagement portion, a first lens holding frame which holds the first lens group and is provided on the fixed barrel so as to be able to move straight in the optical axis direction, and holds a second lens group. The second lens holding frame, the first cam that is rotatably provided inside the first lens holding frame and that engages with the fixed cam engaging portion, and the second lens holding frame moves in the optical axis direction. And a cam ring having a second cam for moving the first lens holding frame and the second lens holding frame by rotating the cam ring in the optical axis direction. In the lens barrel that moves in the optical axis direction depending on the state, the first cam of the cam ring is configured such that the first lens holding frame and the cam from the stored state to the shooting state.
A ring integral with the optical axis direction, when the cam ring rotates together
And a second cam region for integrally moving the first lens holding frame and the cam ring in the optical axis direction during the photographing state. In the second cam, the relative position between the cam ring and the second lens holding frame does not change while the cam ring rotates and is extended in the optical axis direction from the stored state to the photographing state. The first lens holding frame is moved in the optical axis direction by a moving amount different from the moving amount of the first lens holding frame in the optical axis direction while the cam ring is rotating between the first cam area and the photographing state. And a second cam region that allows the lens barrel to move. 3. A fixed barrel, a first lens holding frame which is provided on the fixed barrel so as to be able to move straight in the optical axis direction and holds a first lens group, and a first barrel which is provided on the fixed barrel so as to be able to move straight in the optical axis direction. A second lens holding frame that holds two lens groups; and a first lens that is fixedly rotatable inside the fixed barrel.
A first cam for moving the lens holding frame in the optical axis direction and a second cam for moving the second lens holding frame in the optical axis direction.
A lens barrel for moving the first lens holding frame and the second lens holding frame in the optical axis direction between the stored state and the photographing state by rotating the cam ring. In the first cam region of the cam ring, the first cam region that extends the first lens holding frame in the optical axis direction from the stored state to the photographing state and the photographing state during the photographing state A second cam region for fixing the first lens holding frame in the optical axis direction, wherein the second cam of the cam ring holds the second lens from the stored state to the photographing state. A first cam area for fixing the holding frame in the optical axis direction, and a second cam area for moving the second lens holding frame in the optical axis direction during the photographing state.
And a cam region of the lens barrel. 4. The first lens group is a lens group closest to the object side, and the second lens group is a lens group that moves in the optical axis direction during zooming. 2 or 3 lens barrel. 5. The first cam and the second cam of the cam ring.
The lens barrel according to claim 1, 2 or 3, wherein the cam is a cam separate from the cam. 6. The first cam and the second cam of the cam ring.
2. The cam of claim 1 is a common cam.
Or the lens barrel of 3. 7. A fixed barrel having a fixed cam engaging portion, a first lens holding frame which holds the first lens group and is provided on the fixed barrel so as to be able to move straight in the optical axis direction, and a second lens group. The second lens holding frame, the first cam that is rotatably provided inside the first lens holding frame and that engages with the fixed cam engaging portion, and the second lens holding frame moves in the optical axis direction. And a cam ring having a second cam for moving the first lens holding frame and the second lens holding frame by rotating the cam ring in the optical axis direction. In an optical device that has a lens barrel that moves in the optical axis direction depending on the state, and the first cam of the cam ring moves from the stored state to the shooting state in an optical device that captures an object image from the lens barrel. Until the first lens holding frame and the cam
A ring integral with the optical axis direction, when the cam ring rotates together
A first cam region for feeding, during the shooting state, and a second cam region for the fixed state the first lens holding frame in the optical axis direction, the second cam of the cam ring A first cam region where the relative position of the cam ring and the second lens holding frame does not change while the cam ring rotates and is extended in the optical axis direction from the stored state to the shooting state, An optical device, comprising: a second cam region that moves the second lens holding frame in the optical axis direction during the shooting state. 8. A fixed barrel having a fixed cam engagement portion, a first lens holding frame which holds the first lens group and which is provided on the fixed barrel so as to be able to move straight in the optical axis direction, and holds a second lens group. The second lens holding frame, the first cam that is rotatably provided inside the first lens holding frame and that engages with the fixed cam engaging portion, and the second lens holding frame moves in the optical axis direction. And a cam ring having a second cam for moving the first lens holding frame and the second lens holding frame by rotating the cam ring in the optical axis direction. In an optical device that has a lens barrel that moves in the optical axis direction depending on the state, and the first cam of the cam ring moves from the stored state to the shooting state in an optical device that captures an object image from the lens barrel. Until the first lens holding frame and the cam
A ring integral with the optical axis direction, when the cam ring rotates together
And a second cam region for integrally moving the first lens holding frame and the cam ring in the optical axis direction during the photographing state. In the second cam, the relative position between the cam ring and the second lens holding frame does not change while the cam ring rotates and is extended in the optical axis direction from the stored state to the photographing state. The first lens holding frame is moved in the optical axis direction by a moving amount different from the moving amount of the first lens holding frame in the optical axis direction while the cam ring is rotating between the first cam area and the photographing state. An optical device having a second cam region. 9. A fixed barrel, a first lens holding frame which holds the first lens group and which is provided on the fixed barrel so as to move straight in the optical axis direction, and a second lens holding frame which holds the second lens group, The fixed cylinder is rotatably installed inside the fixed cylinder and
A first cam for moving the lens holding frame in the optical axis direction and a second cam for moving the second lens holding frame in the optical axis direction.
A lens barrel for moving the first lens holding frame and the second lens holding frame in the optical axis direction between the stored state and the photographing state by rotating the cam ring. In the optical device that captures an object image from the lens barrel, the first cam of the cam ring is configured such that the first lens holding frame is an optical axis from the stored state to the shooting state. A second cam region of the cam ring, the first cam region extending in a direction, and a second cam region that fixes the first lens holding frame in the optical axis direction during the photographing state. Is a first cam area for fixing the second lens holding frame in the optical axis direction from the stored state to the photographing state, and the second lens holding frame is used for the optical axis during the photographing state. Second to move in the direction
And a cam area of the optical device. 10. The first lens group is a lens group closest to the object side, and the second lens group is a lens group that moves in the optical axis direction during zooming. 8
Or 9 optical equipment. 11. The optical device according to claim 7, wherein the first cam and the second cam of the cam ring are separate cams. 12. The optical device according to claim 7, wherein the first cam and the second cam of the cam ring are common cams.