JPS63194213A - Zoom lens barrel - Google Patents

Abstract

PURPOSE:To simultaneously execute a lead-in operation of a lens barrel and a closing operation of a photographic lens barrier by providing an operable and closeable photographic lens barrier so that a cam pin of a moving frame responds to a housing driving operation extending from one end to one end of a housing cam groove part and the photographic lens barrier is closed. CONSTITUTION:When the rotation of a zoom driving frame 2 is continued, a first cam pin 5 and a second cam pin 16 move by being controlled by a first cam groove 2a and a second cam groove 2b, and both lenses 3, 14 are led into a lens barrel. In cooperation therewith, the first cam pin 5 pushes and moves the driven part 8a of a barrier driving lever 8, and a driven pin 10 is brought to pushing and moving operation by a driving part 8b, therefore, a driving plate 9 rotates clockwise against the tensile force of a tension spring 9a. As a result, driven pins 11b, 11d engaged with long holes 9b, 9c formed on this driving plate 9 move clockwise, and by these driven pin 11b, 11d, first barriers 11A, 11B are closed. In such a way, in cooperation with the lead-in operation, the photographic lens barrier can be driven to open and close.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a zoom lens barrel, and more particularly to a zoom lens barrel in which the zoom is driven by the rotational driving force of a motor.

(b) Prior Art In general, when zoom driving is performed by selectively driving each of a plurality of lens groups constituting a zoom optical system in a zoom lens barrel, a zoom lens that rotates along the circumferential direction of the optical axis is used. A drive frame is provided.

This zoom drive frame is manually driven.

In recent years, electronic automation of exposure, film feeding, automatic focusing, etc. in still cameras has progressed, and the size of still cameras has been significantly reduced, and zoom lens barrels are no exception.

That is, in order to make the camera more compact, there are already on the general market cameras in which the lens barrel is retracted (sinking) when not photographing.

However, cameras equipped with the above-mentioned retractable lens require a complicated mechanism to retract the lens barrel, and the retracting operation is troublesome, especially for zoom lenses. The problem was big in this case.

Furthermore, the lens barrel of the zoom lens mentioned above protrudes beyond the front of the camera, so like a general compact camera, a shooting lens barrier is stored in the front of the camera and the front of the shooting lens is closed when not in use. It cannot be configured to cover. Therefore, the only options are to provide a photographing lens barrier on the lens barrel side rather than on the camera body side, or to attach a lens cap to the lens barrel.

However, since lens caps are not needed when taking pictures, they tend to lose powder because they are placed in pockets or near the shooting location, and they are difficult to use.
On the other hand, even if the photographic lens barrier is placed at the front of the lens barrel, a drive mechanism is required in addition to the photographic barrier to open and close it, making the lens barrel more complex, larger, and more expensive. In addition, the photographic lens barrier must be opened and closed each time the camera body is switched between a photographing state and a non-photographing state, resulting in extremely poor operability, especially quick shooting performance.

(c) Purpose The present invention has been made in view of the above-mentioned circumstances.The purpose of the present invention is to have a simple and compact structure so that when the lens barrel is not in use, it can be retracted by a predetermined amount to make it compact. It is an object of the present invention to provide a zoom lens barrel capable of simultaneously performing a closing operation of a photographing lens barrier by retracting the lens barrel.

(d) Structure In order to achieve the above-mentioned object, the present invention provides a plurality of movable lens groups that are arranged to be slidable in the optical axis direction with respect to the fixed lens barrel when each of the plurality of lens groups is fixed. In a zoom lens barrel that drives a zoom drive frame by electrically driving a zoom drive frame having a plurality of cam grooves each of which engages with a cam pin provided on each frame, the cam grooves formed in the zoom drive frame are At least on the extension line of one end side of the zoom drive range of the cam groove that engages with the cam pin of the movable frame disposed at the front, there is a storage drive range for retracting the movable frame disposed at the front backward. In order to make the plurality of lens groups into a macro configuration, there is a storage cam groove formed across the macro drive range, and an extension line of each cam groove formed in the zoom drive frame on the other end side of the zoom drive range. A macro drive groove formed over the entire length, a photographing lens barrier that is openable and closable at the front of the zoom lens barrel, and a cam pin of the moving frame located at the front end of the storage cam groove. The photographing lens barrier is closed in response to a storage driving operation in which the cam pin slides into contact with the terminal end of the storage cam groove, and the photographing lens barrier is closed in response to a feeding drive operation in which the cam pin slides in sliding contact with the storage cam groove from the terminal end to the starting end. The invention is characterized by comprising a barrier drive member that opens the barrier drive member.

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

This embodiment shows an example in which the present invention is applied to a so-called multifocal compact camera, which is a camera in which a zoom lens barrel of a type in which lenses are driven by an electric motor in a macro area and a zoom area is fixed to a camera body. Further, this embodiment is an example in which the zoom optical system is composed of five lens groups, and the photographing lens is composed of a zoom lens that performs zoom movement by moving all the lens groups in a composite manner.

FIG. 1 is a schematic cross-sectional view showing the configuration of an embodiment of a zoom lens barrel according to the present invention, in which the camera body (not shown) is
A cylindrical fixed TTT cylinder 1 is integrally fixed to the cylindrical fixed TFT cylinder 1, and the outer periphery of this fixed TFT cylinder 1 prevents movement in the direction of the optical axis P, and slides in the circumferential direction around the optical axis P. A removably supported zoom drive frame 2 is provided.

Further, a cylindrical first movable frame 4 with a first lens group 3 fixed to the front portion is arranged on the inner circumference of the fixed lens barrel 1 so as to be slidable on its rear outer circumference. has been done. At the rear of this first moving frame 4.

A first cam pin 5 protruding outward is fixed by a screw connection. As shown in the developed view of the cam in FIG. 2, the first cam pin 5 fits into a straight groove 1a formed in the fixed lens barrel 1 parallel to the optical axis β, and also fits into the straight groove 1a. The first cam grooves 2a are also fitted into first cam grooves 2a formed in the zoom drive frame 2 so as to intersect with each other. Furthermore, the shape of the first cam groove 2a has a zoom curved portion in the middle region corresponding to the zoom drive angle 02, and continues from the long focal point side end to the region corresponding to the macro drive angle θ. The macro drive groove portion is continuously formed. Furthermore, the above-mentioned first
A storage cam groove is formed for retracting and storing (collapsing) the movable frame 4 rearward.

Now, an outer casing 6 which has a cylindrical shape and is integrally attached to the camera body in the same way as the fixed lens barrel 1 described above is provided so as to surround the outer periphery of the zoom drive frame 2, and the front thereof is A support shaft 7 having a funnel-shaped opening and protruding inward toward the front of the intermediate portion is fixed by caulking, and a barrier drive lever 8 is rotatably supported by this support shaft 7.

As shown in detail in FIG. 4, this barrier drive lever 8 has a driven portion 8a formed on the side surface of one arm as described above.
The first cam pin 5 is brought into contact (pushed) with the rotation of the zoom drive frame 2, and when the first cam pin 5 enters the storage drive angle θ1 within its drive range. The barrier drive lever 8 is adapted to rotate clockwise.

Further, in the front opening of the outer casing 6, a disk ring-shaped drive plate 9 to which a driven pin 10 protruding rearward is fixed is supported so as to be rotatable around the optical axis P. As shown in detail in FIG. 3, a barrier 11 consisting of two semicircular first and second barriers 11A and IIB is provided adjacent to the barrier 9. Then, this first and second barrier 1
1A.

At the base end of each of the spindles 11B, there is a support shaft 11 that protrudes forward.
The support shafts 11a and llc are rotatably supported in support holes 12a and 12b formed in a fixed plate 12 fixed to the front part of the outer casing 6.

Further, the drive plate 9 is given a counterclockwise rotational habit by a tension spring 9a, and long holes 9b and 9c are formed, and the lengths of the holes 9b and 9c are the same as the first and second holes.
It is designed to fit into driven pins llb and lid that protrude rearward of the barriers IIA and IIB, respectively. Furthermore, a cover plate 13 is fixed in front of this fixed plate 12.

Now, on the inner periphery of the above-mentioned fixed lens barrel 1, the above-mentioned first movable frame 4 is provided.
A second movable frame 15 formed in a split mold that does not interfere with the movement is slidably provided, a second group lens 14 is fixed to the second movable frame 15, and a second cam pin 16 is attached to the periphery of the second movable frame 15. It is fixed by a screw connection. And this second cam pin 16.

Movement in the zoom driving direction is performed by the straight groove 1b and the second cam groove 2'b similar to those described above, and the second cam groove 2b also has the same storage drive angle 01 to macro drive angle θ, as described above. Similar grooves are provided in regions corresponding to the respective regions. Furthermore, a third movable frame 18 is provided on the inner periphery of the fixed lens barrel 1.
is slidably provided, a third group lens 17 is fixed to this, and a third cam pin 19 is fixed to the periphery thereof. This third cam pin 19 is connected to the above-mentioned straight groove 1b.
The third cam groove 2c fits into the second cam pin 16 without interfering with the second cam pin 16, and allows movement in the zoom driving direction by the third cam groove 2c. The shape of the third cam groove 2c is such that a zoom drive cam corresponding to the zoom drive angle θ2 is formed in the middle, and the short focal length end of the third cam groove 2c has a zoom drive cam corresponding to the zoom drive angle θ2. A groove extending in a direction (direction along a plane perpendicular to the axis) is continuously formed, and a groove extending in a circumferential direction over an area corresponding to the macro drive angle θ is continuously formed at the long focal length end of the groove. There is.

Further, a fourth movable frame 21 is slidably provided on the inner circumference of the fixed lens barrel 1, a fourth group lens 20 is fixed to this, and a fourth cam pin 22 is fixed to the periphery of the fourth movable frame 21. There is. The fourth cam pin 22 is moved in the zoom drive direction by the same straight groove IC and fourth cam groove 2d as described above. The shape of the fourth cam groove 2d is similar to the shape of the third cam groove 2c described above, with grooves formed in regions corresponding to the storage drive angle θ, the zoom drive angle θ2, and the macro drive angle θ3, respectively.

Furthermore, a fifth movable frame 24 is slidably formed on the fixed lens barrel 1 and is formed in a split mold so as not to interfere with the fourth movable frame 12. , a fifth group lens 23 is fixed, and a fifth cam pin 25 is fixed to the periphery thereof. The fifth cam pin 25 is fitted into the above-mentioned linear groove 1c without interfering with the fourth cam pin 22, and is also moved in the zoom driving direction by the fifth cam groove 2e. Further, the shape of the fifth cam groove 2e is such that a zoom drive cam groove corresponding to the zoom drive angle θ2 is formed in the middle, and the short focal length end thereof has a circular direction extending over an area corresponding to the storage drive angle θ1. A groove extending to .theta. is continuously formed, and at the long focal length end thereof, a groove is continuously formed in a region corresponding to the macro drive angle .theta..

On the other hand, a tooth surface 2' is provided on the rear peripheral surface of the zoom drive frame 2.
An output gear 26 fixed to the tip of an output shaft 27 of a cylindrical focus drive motor (not shown) meshes with this tooth surface 2', and by rotating the motor, a zoom drive is performed. Frame 2 is designed to be rotated.

The zoom lens barrel according to this embodiment configured as described above operates in a first-order manner.

Now, the rotation of the zoom drive motor (not shown) is on the output shaft 27.
When the output gear 26 rotates, the zoom drive frame 2
is driven to rotate.

Then, the first to fifth cam pins 5, 16, 19, 22, and 25 move into the first to fifth cam grooves 2a while their rotation in the circumferential direction is restricted by the straight grooves 1a, lb, and lc, respectively.
~2e are moved in the direction of the optical axis P according to their respective shapes, and these first to fifth cam pins 5, 16, 19, 22, 2
1st to 5th moving frames 4, 15, 18, 21 where 5 was planted
．． 24, the first to fifth group lenses 3°14.17, 20, and 23 move by a predetermined distance in the direction of the optical axis P as shown in FIG. 5, forming a predetermined zoom photographing lens optical system. It is. The range of such zoom drive is within the range of zoom drive angle θ2.

On the other hand, when the zoom drive motor is energized for macro photography, the zoom drive frame 2 is rotated and moved from the long focal point end of the zoom area with the zoom drive angle θ2 to the macro area with the macro drive angle θ, as described above. However, the first cam pin 5 and the second cam pin 16 move in the direction of the optical axis P by an amount defined by the first cam groove 2a and the second cam groove 2b in the macro area. Accordingly, the first moving frame 4 (first lens group 3) and the second moving frame 15 (second lens group 14) also move in the optical axis P direction. At this time, the third to fifth group lenses 17,
20.23 is the third to fifth cam grooves 2c.

Since the shapes of 2d and 2e extend in a plane perpendicular to the optical axis P, they do not move in the optical axis P direction.

In the various cases described above, the first cam pin 5 is not in contact with the driven portion 8a of the barrier drive lever 8, so the relationship between the driving portion 8b and the driven pin 10 is indicated by the broken line in FIG. As shown, the numbers 8b' and 10' are shown, and at this time, since the driving plate 9 is biased counterclockwise by the tension spring 9a, the elongated hole 9b
, 9c are located at the positions indicated by symbols 9b' and 9c',
Along with this, the driven pins llb and lid are changed to 11b.
'.

Located at the position indicated by 11d', the first barrier 11A.

11B is opened and the front surface of the lens is exposed.

Next, when the zoom drive motor is energized to put the lens barrel into the retracted state when not photographing, the zoom drive frame 2 rotates, and as described above, from the short focus end of the zoom drive area of the zoom drive angle θ2 to the retraction drive angle. θ, the first group lens 3 and the second group lens 14, the first cam pin 5 and the second cam pin 16 emit light by an amount defined by the first cam groove 2a and the second cam groove 2b. It is retracted by moving backward along the axis P direction.

At this time, the third to fifth group lenses 17, 20°23 are
The shape of the third to fifth cam grooves 2c, 2d, and 2e is the optical axis P.
Since it is formed along the plane perpendicular to the optical axis P
It does not move in any direction.

Furthermore, when the rotation of the zoom drive frame 2 continues, the first cam pin 5
and the second cam pin 16 is connected to the first cam groove 2a and the second cam groove 2b.
Both lenses move 3°14 (first moving frame 3).
．． The second moving frame 15) is retracted into the lens barrel as shown in FIG.

In cooperation with such a feeding operation, the first cam pin 5 pushes the driven part 8a of the barrier drive lever 8, and the driving part 8b
Since the driven pin 1o is pushed, the drive plate 9 rotates clockwise against the tensile force of the tension spring 9a.

Then, the driven pins 11b and lid that engage with the long holes 9b and 9c formed in the drive plate 9 move clockwise, and the driven pins llb and lid close the first barrier IIA,
IIB is closed as shown by the solid line in FIG.

When performing zoom shooting from such a stored state, you can move to the zoom area or macro area by energizing the zoom drive motor in the opposite direction to that described above. be.

Therefore, in this embodiment, the barrier can be closed by driving the zoom drive frame 2 to the storage area that is continuous with the short focus end of the zoom drive range in the zoom lens barrel, and the zoom drive frame 2 By driving the lens from the storage area to the short focus end of the zoom drive range, the barrier can be opened automatically.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

For example, it goes without saying that the lens configuration of the optical system in the zoom lens barrel is not limited to the five-group configuration described above, but may be any other type.

Also, it is optional to choose whether the zoom lens barrel is fixed to the camera body or in the form of an interchangeable lens.

The motor for driving the zoom may be housed within the zoom lens barrel, or may be housed within the camera body and may be configured to drive the zoom drive frame of the zoom lens barrel via a coupling.

Further, the focusing means is the fifth group lens 2 described above.
Of course, a rotating helicoid may be interposed between the third and fifth moving frames 24, or the entire lens system may be moved, or other lens groups may be moved.

(e) Effect As described above, according to the present invention, the macro mode can be achieved by simply rotating the zoom drive frame from the zoom drive area to the macro area or the storage area using the electric motor, without using any complicated configuration. In addition to being able to retract the lens barrel in storage mode to make it more compact, the photographic lens barrier can be opened and closed in conjunction with this retracting operation without any additional operations, making it possible to take pictures easily. It can improve quick shooting performance when not in use, is compact when not in use (when carried), and prevents dust from forming on the lens surface.

It is possible to provide a zoom lens barrel that can effectively prevent the adhesion of fingerprints and the like and damage caused by external forces.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing the structure of an embodiment of a zoom lens barrel according to the present invention, and FIG. 2 is a cam development showing the relationship between the cam groove, the straight groove, and the cam pin shown in FIG. 1. 3 is an enlarged front view showing details of the barrier shown in FIG. 1, FIG. 4 is an enlarged view showing details of the barrier drive lever shown in FIG. 1, and FIG. 5 is an enlarged front view showing details of the barrier drive lever shown in FIG. Similarly, the sixth diagram is a diagram showing the relationship between the rotation angle of the zoom drive frame and the amount of movement of each lens group.
The figure is a sectional view showing the storage and retracted state in the same embodiment. 1... Fixed tttM, 1a to 1c... Straight groove, 2... Zoom drive frame, 2'... Tooth surface, 2a to 2e... ...1st to 5th cam grooves. 3.14.17, 20.23... 1st to 5th group lenses, 4.15.18, 21.24... 1st to 5th moving frames, 5.16, 19 , 22.25, 1st to 5th cam pins, 6... Outer casing, 8... Barrier drive lever, 8a... Driven part, 8b... ... Drive unit, 9... Drive plate, 9a... Group...
Tension spring, 10... Driven pin, 11
... Barrier, 12 ... Fixed plate,
13. Old... Cover plate, 26... Output gear, 27. Old... Output shaft.

Claims (1)

[Claims] (1) Each of the plurality of lens groups is fixed, and each of the plurality of moving frames is arranged to be slidable in the optical axis direction with respect to the fixed lens barrel. In a zoom lens barrel that zooms by electrically driving a zoom drive frame having a cam groove, the cam groove formed in the zoom drive frame engages with a cam pin of a movable frame disposed at least forwardly. A storage cam groove is formed on the extension line of one end of the zoom drive range of the cam groove and extends over the storage drive range in order to retract the movable frame disposed at the front to the rear, and a storage cam groove is formed on the zoom drive frame. A macro drive groove portion formed across the macro drive range in order to configure the plurality of lens groups into a macro configuration is formed on the extension line of each cam groove on the other end side of the zoom drive range, and a macro drive groove portion is formed at the front of the zoom lens barrel. The photographing lens barrier is opened and closed in response to the storage drive operation in which the photographing lens barrier is opened and closed in the storage cam groove portion, and the cam pin of the movable frame provided in the front slides into contact with the storage cam groove portion from the starting end to the terminal end. close the
A zoom lens barrel comprising: a barrier drive member that opens the photographing lens barrier in response to a feeding drive operation in which the cam pin slides into contact with the storage cam groove from the terminal end to the starting end.