JP2003177297A - Optical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide optical equipment maintaining optical performance, realizing the miniaturization of a lens barrel at the non-photographing time and constituted so that an accessory can be directly attached. <P>SOLUTION: The optical equipment is equipped with a 1st lens group L1 constituting an optical system, a 2nd lens group L2 provided on the image surface side of the optical axis of the 1st lens group L1, and a driving motor 22 driving the 1st lens group L1 and the 2nd lens group L2 by using a cam barrel 21 where a plurality of cam grooves 21a and 21b are formed so that the 1st lens group L1 may be started to be withdrawn after withdrawing the 2nd lens group L2 in response to the housing instruction of the optical system, and the 1st lens group L1 may be withdrawn to space left by withdrawing the 2nd lens group L2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device using a lens barrel such as a video movie, which is excellent in portability, in which the length of the lens barrel is shortened when not photographing, compared to when photographing. is there.

[0002]

2. Description of the Related Art In recent years, along with the widespread use of digital video movies, miniaturization is desired. Therefore, an optical device using a so-called collapsible lens barrel is proposed in which the length of the lens barrel is shortened during non-shooting in consideration of portability during non-shooting as the lens barrel is downsized.

Conventionally, as a collapsible lens barrel for optical equipment, one described in the patent document is known. Figure 1
1 and 12 show the structure of a conventional retractable lens barrel.

In the figure, L1 is a first lens group which is fixed at the time of photographing (during zooming and focusing), and L2 is a second lens group for zooming.
A lens unit L3 is a third lens unit fixed at the time of shooting, and a lens unit L4 is a fourth lens unit that moves on the optical axis at the time of correction of image plane variation due to zooming and focusing. Reference numeral 31 is a fixed barrel that holds the image sensor FA in a fixed manner. 37 is a first holding frame,
It holds the first lens unit L1. Reference numeral 39 denotes a second holding frame, which holds the second lens unit L2, and the first holding frame 3
Bars 40 and 4 fixed between 7 and female helicoid 43
1 makes it possible to move in the optical axis direction. The female helicoid 43 is fixed to the first holding frame 37 and is coupled to the helicoid provided on the outer peripheral portion of the fixed barrel 31. Reference numeral 42 denotes a drive motor that drives the first lens group L1, that is, the first holding frame 37 in a straight line direction in the optical axis direction by engaging a gear 43a provided on the outer peripheral portion of the female helicoid 43 with an output gear 42a during non-photographing. I am letting you.

[0005]

[Patent document] Japanese Unexamined Patent Publication No. 8-179188

[0006]

However, the conventional retractable lens barrel optical apparatus has the following problems.

(1) When the first lens unit L1 is moved at the time of photographing, it is necessary to minimize the positional deviation with respect to the other lens units and reduce the adverse effect on the optical performance, but the first holding frame 37 is fixed. Due to the rattling of the cylinder 31, the optical deviation could not be minimized. Further, since the first holding frame 37 is guided to the outer peripheral surface of the fixed barrel 31, the size of the lens barrel becomes large, and the first lens group L1 is exposed to the outside even during non-shooting. I couldn't.

(2) When the first lens unit L1 is moved,
The first lens unit L1 projects from the optical device body. Therefore, when an external force is applied to the projecting portion, a force is applied to the lens itself and a positional shift occurs, so that basic optical performance cannot be maintained.

(3) Accessories such as a conversion lens and a filter cannot be directly attached to the protruding first lens unit L1.

Therefore, an object of the present invention is to provide a collapsible lens barrel which can maintain the optical performance, reduce the size of the lens barrel when not photographing, and directly mount an accessory. It is to provide an optical device using the.

[0011]

According to another aspect of the present invention, there is provided an optical device comprising: a first lens group which constitutes an optical system; and a second lens group which is provided on the optical axis image plane side of the first lens group. Then, in response to an instruction to store the optical system, the first lens after the second lens group is retracted.
Of the first lens group is started by using the cam frame in which a plurality of cam grooves are formed so that the first lens group is retracted into the space vacated by the retraction of the second lens group. And a drive unit for driving the lens group and the second lens group.

According to the optical apparatus of the first aspect, the first lens group is started to be retracted after the second lens group is retracted, and the first lens is provided in the space vacated by the retraction of the second lens group. Since the group is retracted, the length of the lens barrel in the optical axis direction can be shortened during non-photographing, the optical device can be downsized, and the portability can be improved. In addition, it is possible to reduce adverse effects on optical performance, to directly attach the accessory, and to reduce costs.

According to a second aspect of the present invention, there is provided an optical system in which a first lens group constituting the optical system, a second lens group provided on the optical axis image plane side of the first lens group, and an extension of the optical system. In response to the instruction, after the first lens group is extended, the second lens group is started to be extended, and the second lens group is extended to the space vacated by the extension of the first lens group. It is provided with a driving means for driving the first lens group and the second lens group by using the cam frame in which the groove is formed.

According to the optical device of the second aspect, the same effect as that of the first aspect can be obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An optical apparatus using a retractable lens barrel of a proposed example which is the basis of the present invention will be described with reference to FIGS. 1 and 2.

L1 is a first lens group that is fixed during shooting, L2 is a second lens group for zooming, L3 is a third lens group that is fixed during shooting, and L4 is correction and focusing of an image plane variation due to zooming. In this case, the fourth lens group moves along the optical axis.

Reference numeral 1 denotes a first holding frame, which is a first lens unit L1.
Holding One end of two guide poles (guide members) 7 is fixed to the first holding frame 1. Generally, in a lens barrel used for a video movie, the diameter of the first lens unit L1 is the largest. Therefore, by fixing one end of the guide pole 7 to the position of the outermost diameter of the first lens unit L1 or fixing it in the optical axis center direction from the position of the outermost diameter of the first lens unit L1, the outer diameter of the lens barrel which is increased by making the lens barrel retractable The increase can be minimized. 2 is the second lens unit L2
It is a second holding frame for holding and is movable by the two guide poles 7 in the optical axis direction. Further, the second holding frame 2 is moved in the optical axis direction by a driving force from the driving motor 11 via a feed screw (not shown) to perform zooming.
Reference numeral 3 denotes a fixed third holding frame for holding the third lens unit L3, which is sandwiched and fixed by the main body 6 and the master flange (fixed lens barrel) 5. A fourth holding frame 4 holds the fourth lens unit L4, and is movable in the optical axis direction by two guide poles 8 held between the third holding frame 3 and the master flange 5. Further, the fourth holding frame 4 is moved in the optical axis direction by a driving force from the driving motor 12 via a feed screw (not shown) to correct an image plane variation due to zooming and perform focusing. There is. An image sensor 13 is fixed to the master flange 5. Reference numeral 14 is a diaphragm unit.

A guide pole 7 is provided on the master flange 5.
Supports 9 and 10 for slidably supporting the lens are provided in parallel with the center of the optical axis. The support portion 9 is composed of two metal bearings 9a and 9b integrated with the master flange 5, and sufficient accuracy such as difference in inner diameter of these metal bearings 9a and 9b and coaxiality is ensured. Therefore, since the guide pole 7 slides on the two support portions 9 and 10, the first pole held by the first holding frame 1 to which one end of the guide pole 7 is fixed is held.
The optical axis center of the lens group L1 does not deviate from the optical axes of the fixed lens group L3 and the focusing lens group L4 and the center of the image sensor 13 even if the first holding frame 1 moves. Therefore, predetermined optical performance can be secured. The second holding frame 2 that moves during zooming also moves in the optical axis direction by the guide pole 7, so
Like the holding frame 1, it does not deviate from the optical axis.

Reference numeral 15 is a driving motor (driving means) for moving the first holding frame 1, and the feed screw 15a integrally provided via the reduction gear is attached to the projection 1a of the first holding frame 1. It meshes with the provided screw part. Therefore, the first holding frame 1 can be moved in the optical axis direction by the rotation of the drive motor 15.

The operation of the retractable lens barrel constructed as described above will be described below.

First, the operation for shifting from the shooting state shown in FIG. 1 to the non-shooting state shown in FIG. 2 will be described.

When the shooting preparation switch or the like is turned off from the shooting state shown in FIG. 1, the shooting ends. The second holding frame 2 is moved to the image plane side (direction of arrow A) by the drive motor 11. Next, the drive motor 15 rotates and the feed screw 15a rotates, so that the first holding frame 1 moves in the image plane direction. The sensor detects that the first holding frame 1 has moved to a predetermined position, and the rotation of the drive motor 15 stops. As a result, as shown in FIG. 2, the lens barrel is in a retracted state in which the length of the lens barrel in the optical axis direction is shortened by the distance b as compared with the case of FIG. Thus, the drive motor 11 and the drive motor 15 respond to the storage instruction of the optical system by the second lens group L.
After the second lens group L1 has been retracted, the first lens group L1 starts to retract, and the first lens group L1 is controlled to retract into the space vacated by the retraction of the second lens group L2.

Next, from the non-photographing state shown in FIG.
The operation at the time of shifting to the state at the time of shooting shown in will be described.

When the photographing preparation switch or the like is turned on from the non-photographing state of FIG. 2, the photographing preparation state is set. The drive motor 15 rotates and the feed screw 15a rotates, so that the first holding frame 1 moves to the object side (the direction opposite to the arrow A). The sensor detects that the first holding frame 1 has moved to a predetermined position, and the rotation of the drive motor 15 stops.
As a result, the first lens unit L1 shown in FIG. 1 is fixed at a predetermined position at the time of photographing. Here, the first holding frame 1 moves to a predetermined position, but the guide pole 7 slides on the supporting members 9 and 10 of the master flange 5 mounted with high precision, so that the guide pole 7 is fixed to the first holding frame 1.
The holding frame 1 also does not deviate from the center of the optical axis, and a predetermined optical performance can be secured. During actual shooting, drive motor 1
After the second holding frame 2 and the fourth holding frame 4 are moved to the initial positions by 1 and the driving motor 12, respectively, the zooming operation and the correction of the image plane variation accompanying the zooming and the focusing operation are started. . That is, in response to an instruction to extend the optical system, the first lens group L1 is extended, the extension of the second lens group L2 is started, and the second lens group L2 is extended to the space vacated by the extension of the first lens group L1. The drive motors 15 and 11 are controlled as described above.

As described above, according to this proposal, one end of at least two guide poles 7 is connected to the first lens unit L1.
Is fixed to the first holding frame 1 for holding, and the other end of the guide pole 7 is provided on the master flange 5 with supporting portions 9,
Since it is slidably supported, it is possible to minimize the optical shift when the first lens unit L1 is moved, and reduce the adverse effects on the optical performance. Further, by providing the guide pole 7 as described above while suppressing the increase in the outer diameter of the lens barrel which is increased by adopting the retractable type, the first holding frame 1 is provided with the optical axis of the master flange 5. The shape can be stored in the body 6 on the object side, and the length of the lens barrel in the optical axis direction at the time of non-shooting can be shortened, so that the optical device can be downsized and the portability can be improved. be able to.

In this proposed example, the movement of the first holding frame 1 in the optical axis direction is performed using the feed screw 15a, but other configurations such as a linear motor may be used. Further, it is also possible to use only two guide poles and move the fourth holding frame 4 as well as the second holding frame 2 in common. Alternatively, a configuration may be adopted in which a slide motor of a viewfinder provided in the optical device is used as a trigger to operate a drive motor that moves the first holding frame 1.

Further, in this proposal example, the optical system in which the first lens unit L1 is extended to the object side at the time of photographing and fixed at a predetermined position to be used, but the first lens group L1 is changed by changing the optical system. It is possible to use a variable length system in which the group L1 is used at an arbitrary position while moving, and the lens barrel length is changed according to the magnification of zooming.

Next, a first embodiment of the present invention will be described with reference to FIGS. The same components as those described above are designated by the same reference numerals and the description thereof will be omitted.

Reference numeral 1 denotes a first holding frame, which is a first lens unit L1.
Holding The first holding frame 1 is held by a guide pole 20 fixed to the main body 6 and the third holding frame 3 so as to be movable in the optical axis direction. Further, a cam shaft 1c is provided on one side of the first holding frame 1. A second holding frame 2 holds the second lens unit L2, and like the first holding frame 1, is held by two guide poles 20 so as to be movable in the optical axis direction. And second
A cam shaft 2a is provided on one side of the holding frame 2. Reference numeral 21 is a cam cylinder having a circular cross section having cam grooves 21a and 21b, and the outer circumference of the cam cylinder can slide around the inner circumference of the main body 6 to rotate about the optical axis.

FIG. 5 shows the shape of the cam barrel 21.
Reference numeral 21a is a cam groove in which the cam shaft 1c of the first holding frame 1 slides, and 21b is a cam shaft 2a of the second holding frame 2.
Is a sliding cam groove. In the cam groove 21a, the cam barrel 2
The cam shaft 1c advances in the direction of the arrow D by the constant rotation of 1 in the direction of the arrow B. The first holding frame 1 moves in the optical axis direction by the distance d due to the movement of the cam shaft 1c, but when the position M is exceeded, the cam groove 21a is orthogonal to the optical axis, so that the first holding frame 1 does not move further in the optical axis direction. . That is, this position is the predetermined position of the first holding frame 1 at the time of shooting.
In the cam groove 21b, the cam barrel 21 makes a constant rotation in the direction of arrow B, but since it is initially orthogonal to the optical axis, the second holding frame 2 does not move in the optical axis direction until the position N is reached. After that, when N is exceeded, it becomes possible to move by the distance e. That is, this distance e is the range of magnification change. Further, a gear 21c is provided in a part of the cam barrel 21, and the gear 22c of the drive motor 22 is provided.
It meshes with a.

The operation of the retractable lens barrel constructed as described above will be described below.

First, the operation for shifting from the shooting state shown in FIG. 3 to the non-shooting state shown in FIG. 4 will be described.

When the photographing preparation switch or the like is turned off from the photographing state shown in FIG. 3, the photographing is completed. Drive motor 2
2 rotates, and the cam barrel 21 rotates in the direction of arrow C, so that the cam shaft 2a moves along the cam groove 21b along arrow E.
And slides in the opposite direction and moves to the N position closest to the image plane in the zoom range. That is, the second holding frame 2 has moved to the most image plane side, and it does not move further in the optical axis direction. When the cam barrel 21 further rotates, the cam shaft 1c
Exceeds the position of M and the first holding frame 1 moves in the image plane direction. Then, the sensor detects that the first holding frame 1 has moved a distance d and has reached a predetermined position, and the drive motor 22
Stops rotating. As a result, as shown in FIG. 4, the lens barrel is in a retracted state in which the length of the lens barrel in the optical axis direction is shortened by the distance c as compared with the case of FIG.

Next, from the non-photographing state shown in FIG.
The operation at the time of shifting to the state at the time of shooting shown in will be described.

When the photographing preparation switch is turned on from the non-photographing state of FIG. 4, the photographing preparation state is set. When the drive motor 22 rotates and the cam barrel 21 rotates in the arrow B direction, the cam shaft 1c slides in the arrow D direction along the cam groove 21a, and the first holding frame 1 moves the optical axis by the distance d. Move toward the object. Even if the cam barrel 21 is rotated further, the first
Since the holding frame 1 does not move in the optical axis direction, the first
The holding frame 1 is fixed. That is, this state is the state at the start of shooting. At the time of actual photographing, the drive motor 22 further rotates to rotate the inside of the variable power range e in the forward and reverse directions to perform the variable power operation. At the same time, the fourth holding frame 4 is driven by the drive motor 12 to perform correction of the image plane variation due to zooming and focus operation.

As described above, according to this embodiment, the length of the lens barrel in the optical axis direction can be shortened at the time of non-photographing, so that the optical device can be downsized and the portability can be improved. You can Moreover, it is possible to minimize the deviation of the optical axis when the lens is moved during shooting, and reduce adverse effects on the optical performance. That is, since the guide pole 20 guides the movement of the first holding frame 1 and the second holding frame 2 in the optical axis direction, it is possible to minimize the optical shift when the first lens unit L1 moves, and to reduce the optical performance. The adverse effect can be reduced. Along with this, the shape of the first holding frame 1 can be reduced, and the first holding frame 1 and the second holding frame 1 can be used during non-shooting.
Since the holding frame 2 is moved to the optical axis image plane side and housed in the main body 6, the lens barrel can be downsized. Further, the cam grooves 21a, 2 with which the first holding frame 1 and the second holding frame 2 engage with each other.
A cam cylinder 21 having a circular cross section having 1b is arranged on the main body 6 so as to be rotatable about the optical axis, and the cam cylinder 21 is rotated by a rotating means, whereby the collapsing operation of the first holding frame 1 and the first lens of the zoom lens. Since the two holding frames 2 can be moved by one drive motor 22, the cost can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 to 9. The optical device of the present invention uses the retractable lens barrel described in the proposed example, but the exterior of this embodiment can be applied to the first embodiment. Therefore, the same reference numerals are given to those described above, and the description thereof will be omitted.

Reference numeral 50 is an optical device such as a video movie. 28 is an optical device 50 for mounting the retractable lens barrel.
Is a first exterior provided on the. 29 is the first exterior 28
On the other hand, it is the second exterior 29 that is movable in the optical axis direction.
The second exterior 29 can be moved by substantially the same amount as the amount of movement of the first holding frame 1 of the retractable lens barrel. Further, a manual button 29 a that allows the second exterior 29 to be moved by a manual operation is attached to the second exterior 29 in a state of protruding from the first exterior 28.

The operation of the optical device constructed as above will be described below.

First, the operation for shifting from the shooting state shown in FIG. 6 to the non-shooting state shown in FIG. 7 will be described.

When the shooting preparation switch or the like is turned off from the shooting state shown in FIG. 6, the shooting ends. The second holding frame 2 is moved to the image plane side by the driving motor 11. Then, the driving motor 15 rotates and the feed screw 15a rotates, so that the first holding frame 1 moves in the image plane direction. The sensor detects that the first holding frame 1 has moved to a predetermined position, and the rotation of the drive motor 15 stops. As a result,
As shown in FIG. 6, the lens barrel is in a retracted state in which the length of the lens barrel in the optical axis direction is shorter by the distance b than in the case of FIG. Then, the operation is completed by moving the second exterior 29 to the image plane side with the manual button 29a.

Next, from the non-photographing state shown in FIG.
The operation at the time of shifting to the state at the time of shooting shown in will be described.

From the non-photographing state of FIG. 7, the manual button 2
When the second exterior 29 is moved to the object side by 9a and it is detected that the second exterior 29 has been moved to a predetermined position, a shooting preparation state is set.
The drive motor 15 rotates and the feed screw 15a rotates, so that the first holding frame 1 moves to the object side. The sensor detects that the first holding frame 1 has moved to a predetermined position, and the rotation of the drive motor 15 stops. As a result, the first lens unit L1 shown in FIG. 6 is in a state at the time of shooting with being fixed at a predetermined position. During actual shooting, drive motor 1
After the second holding frame 2 and the fourth holding frame 4 are moved to the initial positions by 1 and the driving motor 12, respectively, the zooming operation and the correction of the image plane variation accompanying the zooming and the focusing operation are started. .

As described above, according to this embodiment, it is needless to say that the length of the lens barrel in the optical axis direction at the time of non-photographing can be shortened and the portability of an optical device such as a video movie can be improved. By making the exterior of the device slidable, the protruding first holding frame 1 can be protected,
The reliability of the optical device at the time of shooting can be improved.

In this embodiment, the driving motor 15 is driven by turning off the photographing preparation switch, but the driving operation is triggered by the movement of the second exterior 29 in the image plane direction. The motor 15 may be driven.

Further, the second outer casing 29 is a conventional optical device which is replaced with an opening / closing shutter provided on the front surface of the lens barrel, and in conjunction with the operation of feeding and storing the second outer casing 29, The configuration may be such that the opening / closing shutter provided in the optical device is operated.

The exterior sliding movement may be linked with the viewfinder sliding movement. That is, the viewfinder and the exterior are mechanically slid in opposite directions. At the time of shooting, the viewfinder is extended backwards, and this rearward movement causes the exterior to be extended forwards. On the contrary, since the viewfinder is stored in the front during non-shooting, the exterior is stored in the rear by this forward movement.

Finally, a third embodiment of the present invention will be described with reference to FIG. Since the sixth embodiment is used, the same parts as those described so far are designated by the same reference numerals, and the description thereof will be omitted.

Reference numeral 29b is a screw for mounting an accessory such as a conversion lens and a filter shown at 30, which is provided at the tip of the second exterior 29 of the optical device 50. Although the accessory mounting is indispensable for increasing the expandability of the optical device, it cannot be mounted on the fixed portion of the lens barrel because the first holding frame 1 projects toward the object side during photographing. In addition, the first holding frame 1 cannot be directly attached to the first holding frame 1 because the positional accuracy cannot be maintained due to an external force at the time of mounting and an optical axis shift occurs. Then, it is attached to the second exterior 29 for lens protection.

The operation of the optical apparatus constructed as above will be described below.

The second armor 29 is moved to the object side from the non-photographing state (not shown) by the manual button 29a, and when the movement to the predetermined position is detected, the photographing preparation state is set. The drive motor 15 rotates and the feed screw 15a rotates, so that the first holding frame 1 moves to the object side. The sensor detects that the first holding frame 1 has moved to a predetermined position, and the rotation of the drive motor 15 stops. As a result, the first lens unit L1 shown in FIG. 16 is in a state at the time of shooting with being fixed at a predetermined position. In this state, accessory 3
By attaching 0 to the mounting screw portion 29b of the second exterior 29, the accessory can be easily mounted.

As described above, according to this embodiment, it is difficult to mount an accessory, which is difficult for an optical device such as a video movie using a retractable lens barrel, on the exterior by the same amount as the first holding frame 1. It can be realized by a simple configuration of performing. As a result, even an ultra-compact optical device having excellent portability can be provided with various expandability like the conventional optical devices.

[0053]

According to the optical device of the first aspect, the second
The first lens group is started to be retracted after the second lens group is retracted, and the first lens group is retracted into the space vacated by the second lens group. The length can be shortened, the optical device can be downsized, and the portability can be improved.
In addition, it is possible to reduce adverse effects on optical performance,
It is possible to directly attach the accessory and reduce the cost.

According to the optical apparatus of claim 2,
It has the same effect as 1.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part at the time of shooting according to a proposed example that is a basis of the present invention.

FIG. 2 is a cross-sectional view of a main part during non-shooting according to a proposed example.

FIG. 3 is a cross-sectional view of essential parts at the time of shooting according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of a main part at the time of non-imaging according to the first embodiment.

FIG. 5 is a schematic view of the shape of the cam groove of the cam barrel according to the first embodiment.

FIG. 6 is a cross-sectional view of essential parts at the time of shooting according to the second embodiment of the present invention.

FIG. 7 is a cross-sectional view of an essential part at the time of non-imaging according to the second embodiment.

FIG. 8 is a schematic view of an optical device at the time of shooting according to the second embodiment.

FIG. 9 is a schematic diagram of an optical device at the time of non-shooting according to the second embodiment.

FIG. 10 is a cross-sectional view of essential parts when an accessory is attached according to a third embodiment of the present invention.

FIG. 11 is a cross-sectional view of essential parts at the time of shooting with a conventional retractable lens barrel.

FIG. 12 is a cross-sectional view of a main part of a conventional retractable lens barrel during non-shooting.

[Explanation of symbols]

L1 first lens group L2 second lens group L3 Third lens group L4 4th lens group 1 first holding frame 1c camshaft 2 Second holding frame 3rd holding frame 4th holding frame 5 master flange 6 body 7 Guide pole 9,10 Support member 11,15,17,22 Drive motor 20 guide pole 21 cam barrel 21a Cam groove 21b Cam groove 21c gear 22a gear 50 Optical equipment

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeki Murata             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 2H044 BD06 BD11 BE08

Claims (2)

[Claims] 1. A first lens group constituting an optical system, a second lens group provided on the optical axis image plane side of the first lens group, and in response to a storage instruction of the optical system. A plurality of cams are arranged so that the first lens group is started to be retracted after the second lens group is retracted, and the first lens group is retracted into the space vacated by the retraction of the second lens group. An optical device comprising: a driving unit that drives the first lens group and the second lens group using a cam frame in which a groove is formed. 2. A first lens group forming an optical system, a second lens group provided on the optical axis image plane side of the first lens group, and in response to an extension instruction of the optical system. The first
A plurality of cam grooves are formed so that after the lens group is extended, the extension of the second lens group is started, and the second lens group is extended into the space vacated by the extension of the first lens group. An optical device comprising: a driving unit that drives the first lens group and the second lens group by using a cam frame.