JP2003098418A - Lens moving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten lens intervals during a housing operation, and to suppress battery consumption. SOLUTION: When changing variable power, driving a motor 22 for variable power moves first and second lens holding frames 16 and 17 in the direction of an optical axis O, respectively. A third lens holding frame 18 is provided freely movably to the second lens holding frame 17. When focusing, driving a motor 30 for focusing rotates a feed screw 32 to move a movable table 32 in the direction of the optical axis O. A third lens holding frame 18 engages partially with the movable table 32. The movable table 32 is maintained in a state of always engaging with the third lens holding frame 18 by energizing an energizing spring 35. During a housing operation, only the motor 22 for variable power is driven to house the first and second lens holding frames 16 and 17. The third lens holding frame 18 abuts on a stopper frame 36 provided on a fixed cylinder 14 in the meantime, and is brought toward the second lens holding frame 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens moving device used for a photographic camera, an electronic still camera or the like,
More specifically, the present invention relates to a lens moving device that moves a lens to a retracted position where the lens is retracted into a camera body when not in use.

[0002]

2. Description of the Related Art Most cameras using a zoom lens camera have a lens collapsing mechanism, and when not in use, the lens barrel is housed in a camera body for portability. When the lens barrel is stored in the storage position, if the distance between the lens groups incorporated in the lens barrel is too wide, a large storage space is required and the camera body becomes thick. In order to eliminate such inconvenience, Patent No. 2
In the optical device proposed in Japanese Patent No. 925197, the entire optical system is moved to the storage position by driving the first driving means, and the optical system is operated during the storage operation by driving the second driving means for focus adjustment operation. The first lens unit forming the system is brought closer to the second lens unit forming the optical system in front of this, and the respective lens groups are simultaneously moved to the storage position without interfering with each other.

[0003]

However, in the optical device described in the above publication, the second drive means is driven together with the first drive means during the storing operation. In addition, when performing a shooting preparation operation of moving from the storage position to the shooting position, the first
The first and second driving means are driven to separate the second lens unit from the second lens unit. When both of the driving means are driven in this way, the battery will be consumed more during the storage operation and the shooting preparation operation.

The present invention has been made in consideration of the above circumstances, and provides a lens moving device capable of reducing the storage space for retracting the lens barrel as much as possible and the battery consumption accompanying this. The purpose is to do.

[0005]

In order to achieve the above object, in the lens moving device of the present invention, in the process of the storing operation of driving only the second driving means to move the optical system toward the storing position. Spacing means for contacting a part of the front or rear of the second optical unit to bring the second optical unit toward the first optical unit; and the spacing means for moving the second optical unit to the first optical unit. The first driving means and the connecting means for releasing the connection between the second optical unit and the optical unit are provided.

According to this, the connecting means for connecting the first drive means and the second optical unit is detachably provided, and only the second drive means is driven to direct the optical system to the storage position. During the accommodating operation of moving all at once, the spacing means comes into contact with the second optical unit to move the second optical unit toward the first optical unit to release the connection of the connecting means.

The first or second optical unit may be a lens holding frame holding a single lens or a lens group, or may be moved so as to change the distance between them during a zooming operation or a focus adjusting operation. It may be an optical unit composed of a plurality of single-lens lenses or lens groups. When the second optical unit is arranged at the rearmost side of the optical system, it is desirable to use a stopper fixedly provided at the rear side of the second optical unit as the space closing means. Further, when the second optical unit is arranged in front of the first optical system, the third optical unit constituting the optical system arranged in front of the second optical unit at the time of the housing operation is in the housing position. The third optical unit comes into contact with the second optical unit during the movement to bring the second optical unit toward the first optical unit, whereby the connection of the connecting portion is released. In this case, the spacing reducing means corresponds to the third optical unit.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIGS. 1 to 3, a zoom lens 10 of a camera is composed of three groups of first to third lens groups 11 to 13 in order from a subject side. The fixed barrel 14, the cam barrel 15, the first lens holding frame 16, the second lens holding frame 17, and the third lens holding frame 18 for holding the lens groups 11 to 13 and moving them in the direction of the optical axis O. And are used.

The first lens group 1 is attached to the first lens holding frame 16.
1 is fixed, and the second lens group 12 is fixed to the second lens holding frame 17. The fixed barrel 14 has a linear guide opening 19 extending parallel to the optical axis O. A first cam groove 20 for moving the first lens holding frame 16 and a second cam groove 21 for moving the second lens holding frame 17 are formed on the inner circumference of the cam barrel 15. .

A variable power motor 22 is provided outside the fixed barrel 14.
Is fixed. The zoom motor 22 rotates the cam barrel 15 in the circumferential direction about the optical axis O. The first lens holding frame 16 is provided with first cam followers 23 that engage with the first cam grooves 20 through the linear guide openings 19 at three divided positions about the optical axis O, respectively. The second lens holding frame 17 is provided with second cam followers 24 that engage with the second cam grooves 21 through the linear guide openings 19 at three divided positions around the optical axis O, respectively.

The first lens holding frame 16 is used for the variable power motor 2
The drive of 2 moves between the position where it projects from the fixed barrel 14 toward the subject and the storage position where it is stored inside the fixed barrel 14. Although not shown, the outer periphery of the fixed barrel 14 is covered by the camera body, and the first lens holding frame 16 is retracted into the camera body when moved to the storage position. Further, the second lens holding frame 17 changes its interval with respect to the first lens holding barrel 16 during zooming, and approaches the image forming surface side at the storage position. The image forming surface is indicated by reference numeral 25, and a CCD image sensor 26 is fixed here, for example.

Guide rods 27 are fixed to the second lens holding frame 17 at circumferentially divided positions around the optical axis O, respectively. Further, the third lens holding frame 18 is provided with bearing portions 28 that engage with the three guide rods 27, respectively. As a result, the second lens holding frame 17 supports the third lens holding frame 18 movably in the optical axis O direction.

A focusing motor 30 is fixed to the second lens holding frame 17. A feed screw 31 is attached to the shaft of the focusing motor 30. The feed screw 31 is screwed into a screw portion 33 provided on the moving table 32. Mobile stand 3
2 is moved in the direction of the optical axis O by the rotation of the feed screw 31 while being engaged with a rotation stopping guide rod 34 provided on the third lens holding frame 17 and being stopped from rotating.

The movable table 32 is detachably connected to the abutting portion 18a of the third lens holding frame 18, and moves the third lens holding frame 18 toward the second lens holding frame 17. At times, it abuts against the contact portion 18a and engages with it.
Then, the second lens holding frame 17 is urged to urge the third lens holding frame 18 in a direction in which the third lens holding frame 18 is separated from the second lens holding frame 17, that is, in a direction in which the contact portion 18 a is pressed against the moving table 32. A spring 35 is provided. Biasing spring 27
Is a compression coil spring, and a plurality of guide bars 27
It is arranged by inserting each. These biasing springs 35
The movable table 32 and the contact portion 18a are always engaged by the urging of the third lens holding frame 18 via the movable table 32 by driving the focusing motor 30 during focusing.
The focus is adjusted by moving the lens holding frame 17 so as to change the distance.

A stopper frame 36 is formed on the fixed barrel 14 on the optical axis O closest to the image plane. Stopper frame 3
Reference numeral 6 denotes an exposure opening 1 through which the subject light passes.
4a, and the front surface 36a on the subject side during the storing operation
Contacts the rear surface 18b of the third lens holding frame 18 and moves the third lens holding frame 18 toward the second lens holding frame 17 against the bias of the biasing spring 35.

The rotation amount of the cam barrel 15 is detected by the cam barrel rotation position detector 37. This cam barrel rotation position detector 37
Is a code plate 3 provided along the outer circumference of the cam barrel 15.
7a and a slider 37b that slides on the code plate 37a. The control unit 38 reads the code corresponding to the rotational position of the cam barrel 15 from the code plate 37a via the slider 37b to identify the retracted position and the zoom position of the zoom lens.

The focusing motor 30 is a pulse motor. The origin position of the third lens holding frame 18 is the focus initial position (infinity position within the focus adjustment range) away from the second lens holding frame 17. This position can be specified by detecting the light shielding plate 39 provided on the third lens holding frame 18 with the photo sensor 40 provided on the second lens holding frame 17.

A power switch 41, a shutter button 42, a zoom lever 43, etc. provided outside the camera are connected to the control unit 38. When the shutter button 42 is half-pressed, the AF circuit 44 operates to perform the focusing operation. During the focusing operation, the zoom position and the AF circuit 4 at that time
The focus position determined by the combination with the subject distance obtained from 4 is obtained, and the focus motor 30 is rotated by sending a pulse signal corresponding to the focus position to the driver 45,
The third lens holding frame 18 is moved from the initial focus position toward the in-focus position. In addition, the control unit 38 rotates the focusing motor 30 in the opposite direction after the completion of image capturing, and returns the third lens holding frame 18 from the focusing position at that time to the initial focus position. Such a focusing operation program is stored in the memory 46.
Remembered in.

When the power switch 41 is turned off, the storing operation is performed. In the storage operation, only the zoom motor 22 is driven to move the zoom lens 10 to the storage position. When the power switch 41 is turned on, a shooting preparation operation is performed.
In the shooting preparation operation, only the zoom motor 22 is driven to perform the first operation.
And the second lens holding frames 16 and 17 are attached to the fixed cylinder 14 respectively.
To the side of the subject, and the zoom lens 10 is set at the wide end from the storage position. Programs for such a storage operation and a shooting preparation operation are stored in the memory 46.

The zoom lever 43 is, for example, a seesaw type lever, and is operated to either the tele end side or the wide end side. The control unit 38 controls the drive time and the rotation direction of the zoom motor 22 by sending a drive signal via the driver 47 in response to the operation of the zoom lever 43. A program for such a scaling operation is also stored in the memory 46.

FIG. 4 shows the movement of each lens group with respect to the rotational position of the cam barrel 15. The zoom lens 10 is moved between the storage position and the wide position. Tele position is
It is set between the storage position and the wide position. When the zoom lens 10 is in the storage position, the rotational position of the cam barrel 15 is the initial position. The rotation of the cam barrel 15 in the lens feeding direction is from the initial position to the terminal position.

The rotation range of the cam barrel 15 includes a variable power range and a storage range. In the zoom range, the zoom lens 10 is zoomed between the tele end and the wide end. The storage area is an area in which the cam barrel 15 rotates during the shooting preparation operation or the storage operation. In the variable power range, the first and second lens holding frames 16 and 17 are respectively moved in the direction of the optical axis O so that the intervals between them are different, and the focal length of the zoom lens 10 is continuously changed.

In the storage area, the first set at the variable power position.
The second lens holding frames 16 and 17 move toward the storage position. At this time, the third lens holding frame 18
It moves toward the storage position together with the second lens holding frame 17, and comes into contact with the stopper frame 36 during the movement to be moved toward the second lens holding frame 17. The timing at which the third lens holding frame 18 approaches is when the cam barrel 15 rotates to the rotation position F in the storage area.

During the storing operation, only the variable power motor 22 is continuously driven, and the third lens holding frame 18 is driven during the driving.
Comes into contact with the stopper frame 36. Thereby, the storing operation can be performed in a short time. The focusing motor 30 is not driven during the storage operation. When the storage operation is completed, the first and second lens holding frames 16 and 17 are located at the storage positions J and K, respectively. Then, the third lens holding frame 1
8 is a position L closer to the second lens holding frame 17 than at the focus initial position.

In the shooting preparation operation as well as in the collapsing operation,
Only the zooming motor 22 is continuously driven, and the first and second lens holding frames 16 and 17 are extended toward the subject side. Then, the third lens holding frame 18 also moves together with the second lens holding frame 17, and when the cam barrel 15 reaches the rotation position F, the moving table 32 engages with the third lens holding frame 18 and the stopper frame. Leave 36. When the movable table 32 is engaged with the third lens holding frame 18, the third lens holding frame 18 becomes the focus initial position with respect to the second lens holding frame 17. Therefore, the shooting preparation state can be quickly performed.

Next, the operation of the above embodiment will be described. When the camera is not used, the zoom lens 10 is in the storage position. In the storage position, as shown in FIGS. 1 and 5, the first lens moving cylinder 16 is in the storage position J retracted into the fixed cylinder 14, and the second lens holding frame 17 is the first lens holding frame 16. Further, the third lens holding frame 18 is set to the storage position L close to the second lens holding frame 17 with the rear surface 18b of the third lens holding frame 18 abutting the front surface 36a of the stopper frame 36. In this state, the engagement between the movable table 32 and the contact portion 18a is released.

When using the camera, the power switch 41 is turned on. The control unit 38 responds to the turning on of the power switch 41 via the driver 47.
Drive only. The drive of the zoom motor 22 is transmitted to the cam barrel 15, and the cam barrel 15 rotates from the initial position to the end position. When the cam barrel 15 rotates, the first lens holding frame 16 responds to the displacement of the first cam groove 20 along the optical axis O, and the second lens holding frame 17 moves the optical axis of the second cam groove 21. According to the displacement along the direction of O, each is extended toward the subject side.

The second lens holding frame 17 is used for the focusing motor 3
0, the feed screw 31, the moving base 32, the urging spring 35, and the guide rods 27 and 34 are moved together. And the third
The lens holding frame 18 is maintained at that position while being guided by the guide rod 27 while being in contact with the stopper frame 36 by the urging force of the urging spring 35 until the cam barrel 15 reaches the rotation position F. When 15 reaches the rotational position F, the contact portion 18a engages with the moving base 32 and moves together with the second lens holding frame 17. When the contact portion 18a is engaged with the movable table 32, the third lens holding frame 18 becomes the focus initial position.

The controller 38 includes a cam barrel rotation position detector 37.
If it is determined that the cam cylinder 15 has passed the tele end position and reached the wide end position by monitoring the signal from the, the drive of the zoom motor 22 is stopped. This allows the zoom lens 10
Indicates that the shooting preparation operation has been completed.

When taking a picture, the zoom lever 43 is operated to perform zooming. At the time of this operation, the control unit 38 monitors the operation direction and time of the zoom lever 43,
The drive of the variable power motor 22 is controlled by the rotation direction and time corresponding to these. As a result, the cam barrel 15 rotates in the variable power range and the zoom lens 10 is set at the desired variable power position. At this time, the third lens holding frame 18 moves together with the second lens holding frame 17 to be the focus initial position corresponding to the variable power position at that time.

When taking a picture, the shutter button 42
In response to the half-pressing operation of, the control unit 38 drives the AF circuit 44, and is stored in advance in the memory 46 from the combination of the subject distance information obtained from the AF circuit 44 and the zoom position information at that time. The moving amount of the third lens holding frame 18 is obtained by referring to the table.

The control unit 38 sends a pulse signal corresponding to the moving amount to the driver 45 to control the driving of the focusing motor 30. As a result, the third lens holding frame 18 moves in the direction approaching the second lens holding frame 17 from the focus initial position corresponding to the zoom position at that time, and the focus of the zoom lens 10 is focused on the subject. To do. And
When the shutter button 42 is fully pressed after the half-press operation, the CCD image sensor 26 captures an image. After the image capturing is completed, only the focusing motor 30 is driven to return the third lens holding frame 18 to the focus initial position.

The image data obtained by the image pickup by the CCD image sensor 26 is taken into the data processing circuit. The data processing circuit performs various data processing such as white balance adjustment and gamma correction on the image data. The image data from the data processing circuit is also sent to the AE processing circuit. The AE processing circuit determines the subject brightness of the CCD image sensor based on each input image data and the charge accumulation time of the CCD image sensor set in the CCD driver at that time, that is, the shutter speed of the electronic shutter. Calculate the photometric value. And
The control unit 38 determines the shutter time of a new electronic shutter based on this photometric value, and the shutter time is determined by the CCD.
The feedback to the driver is performed, whereby the driving of the CCD image sensor 26 is adjusted and the AE control is performed.

To put the camera in a non-use state, the power switch 41 is turned off. In response to the power switch 41 being turned off, the control unit 38 drives only the variable power motor 22 in the reverse direction. By this drive, the cam barrel 15 rotates toward the initial position. By this rotation, the first and second lens holding frames 16 and 17 are respectively retracted toward the image plane side in accordance with the displacement of the first and second cam grooves 20 and 21 along the optical axis O direction. At this time, the third lens holding frame 18
Since the contact portion 18a is engaged with the movable table 32 by the biasing force of the biasing spring 35, it moves together with the second lens holding frame 17. The rotational position of the cam barrel 15 is the rotational position F.
When it reaches, the rear surface 18b of the third lens holding frame 18 comes into contact with the front surface 36a of the stopper frame 36 and its movement is stopped. At this time, since the movement of the second lens holding frame 17 toward the image forming surface side is continued, the third lens holding frame 18 resists the urging of the urging spring 35 and the second lens holding frame 17 is urged. The contact portion 18a and the moving base 32 are disengaged from each other.

When the cam barrel 15 reaches the initial position, the drive of the zoom motor 22 is stopped. As a result, the first and second lens holding frames 16 and 17 are located at the storage positions J and K, respectively. Then, the third lens holding frame 18 is located at the storage position L that is close to the second lens holding frame 17 in the state where the engagement with the movable table 32 is released.

The second lens holding frame 17 of the above embodiment corresponds to the first optical unit of the present invention, and the third lens holding frame 18 corresponds to the second optical unit of the present invention. Further, the first driving means of the present invention is the focusing motor 3
0, the second driving means corresponds to the variable power motor 22, and the spacing means corresponds to the stopper frame 36. The connecting means of the present invention is composed of the movable table 31, the contact portion 18a, and the biasing spring 35 of the present embodiment.

In the above embodiment, the zooming motor 22 is a motor which is driven only when focusing is performed. However, the present invention is not limited to this, and the zooming for moving the third lens holding frame 18 is also performed during zooming. It may be a dual-purpose focusing motor. Further, the first and second lens holding frames 16 and 17 are structured to be advanced and retracted by the cam mechanism, but the present invention is not limited to this, and any known mechanism such as a helicoid mechanism can be used.

Further, in the above embodiment, the variable power position is identified by the rotational position of the cam barrel 15, but the present invention is not limited to this, and it may be identified by the rotational amount of the cam barrel 15, or , The first or second lens holding frame 16 or 17 may be identified by the movement amount or the movement position.

In the above embodiment, the zoom lens has a three-group structure, but the present invention is not limited to this, and a two-group structure or a four-group structure or more may be used. Further, although the first to third lens holding frames 16 to 18 are arranged in order from the subject side, the present invention is not limited to this order, and for example, the third lens holding frame is held on the subject side of the second lens holding frame 17. Frame 18
May be movably supported. In this case, the third lens holding frame 18 is brought into contact with the first lens holding frame 16 that moves toward the image plane during the storage operation,
May be brought closer to the second lens holding frame 17. In this example, since the third lens holding frame 18 is brought closer to the rear surface of the first lens holding frame 16 located in front of the third lens holding frame 18, the rear surface of the first lens holding frame 16 serves as a space reducing means.

Further, in the above embodiment, the zoom lens camera is used, but the present invention is not limited to this, and the present invention can be applied to a bifocal camera that switches to a tele position, a wide position, and a storage position. Furthermore, the tele position is set between the storage position and the wide position, but it is also possible to set the wide position between the storage position and the tele position. In this case, the boundary between the variable power guide area and the storage guide area is the wide position. Furthermore, in the zoom lens according to the above-described embodiment, the retracted position inside the camera body is the storage position, but the storage position of the present invention is not limited to the retracted position in the camera body, but a lens provided on the front surface of the camera body. It may be placed in the hood.

Further, in the above embodiment, the power switch 4
Although it is configured to perform the shooting preparation operation or the storage operation in response to the operation 1, the present invention is not limited to this, and for example, a protective cover for protecting the shooting lens is provided on the front surface of the camera so as to be openable and closable. The shooting preparation operation or the storage operation may be performed in response to the opening / closing operation of the protective cover.

Further, the present invention can be applied to, for example, a photographic camera as well as the electronic still camera. Further, as the AF circuit 44, an active autofocus circuit including a light projector and a light receiver, or a circuit using a contrast method for determining whether or not the image is in focus by using the contrast of an image obtained from a CCD image sensor is used. You can

Further, in the above embodiment, it is preferable that the initial position of the third lens holding frame 18 is adjusted. In this case, a method of displacing the position of the photo sensor 40, a method of displacing the third lens group 13 in the optical axis direction with respect to the third lens holding frame 18, and a predetermined pulse after the light shield plate 39 is detected by the photo sensor 40. A method of driving the motor 30 to electrically shift the initial position may be adopted.

[0044]

As described above, in the lens moving device of the present invention, the connecting means for connecting the first driving means and the second optical unit to each other in a disengageable manner is provided, and only the second driving means is driven. And the second optical unit together with the first optical unit are moved toward the storage position during the storing operation, the second optical unit abuts on the spacing means and the spacing means moves to the second spacing means.
Since the optical unit is moved toward the first optical unit to disconnect the connection means, the second drive means alone drives the first and second optical units during the storing operation. You can close the gap. This eliminates the need to drive the first driving unit in addition to the driving of the second driving unit during the storage operation, and thus can reduce battery consumption during the storage operation and the shooting preparation operation.

[Brief description of drawings]

FIG. 1 is an end view showing a zoom lens using a lens moving device of the present invention, showing a state of a storage position.

FIG. 2 is an end view showing the zoom lens at a tele position.

FIG. 3 is an end view showing the zoom lens at a wide position.

FIG. 4 is an explanatory diagram showing a movement amount of a zoom lens in an optical axis direction with respect to a rotation amount of a cam barrel.

[Explanation of symbols]

14 Fixed tube 15 Cam tube 16 First lens moving barrel 17 Second lens holding frame 18 Third lens holding frame 18a contact part 22 Motor for zooming 30 Focusing motor 32 mobile platform

Claims (3)

[Claims] 1. An optical system including a first optical unit and a second optical unit supported by the first optical unit so as to be movable in the photographing optical axis direction, and supported by the first optical unit. And a first drive unit for moving the second optical unit so that the interval is changed with respect to the first optical unit for the focus adjustment operation or the magnification changing operation, and the optical system for changing the magnification. A lens moving device comprising: a second driving means for moving the optical system toward a storage position by driving only the second driving means. Spacing means for contacting a part of the front or rear of the second optical unit to bring the second optical unit toward the first optical unit, and the spacing means for moving the second optical unit to the second optical unit. Toward the optical unit 1 Said first drive means when for a second
And a connecting means for releasing the connection with the optical unit. 2. The stopper is provided by arranging the second optical unit at the rearmost position of the optical system and fixing the spacing means at the rear of the second optical unit. The lens moving device according to claim 1. 3. The first drive means comprises a guide means for movably guiding the second optical unit in the optical axis direction, a motor, and a movable table moved in the optical axis direction by rotation of the motor. The connecting means includes a movable table and a second movable table that makes one-sided contact with the movable table when the movable table moves in a direction in which the second optical unit is moved toward the first optical unit. 3. The abutment portion of the optical unit, and an urging means for urging the second optical unit in a direction in which the abutment portion engages with the moving base, as claimed in claim 1 or 2. Lens moving device.