JP5028054B2 - Lens barrel and imaging device - Google Patents

Description

  The present invention relates to a lens barrel that retracts and stores a lens group in one form, and extends and uses the lens group to a predetermined position in another form. In particular, the focal length is obtained by relatively moving a plurality of lens groups. The present invention relates to a lens barrel suitable for a zoom lens that can change the image quality and an imaging apparatus using such a lens barrel.

In an imaging apparatus such as a digital camera, the lens barrel is used for the imaging apparatus main body other than at the time of shooting in accordance with the progress of high performance of a photographing lens such as a zoom lens capable of changing a focal length and downsizing according to user requirements. There is an increasing use of a so-called collapsible photographic lens housed inside. Furthermore, it is important not only to reduce the size but also to reduce the thickness of the lens barrel portion in the retracted state to the limit due to the demand for further thinning.
As described above, as a technique for coping with the demand for thinning of the imaging device, a retractable configuration in which the lens barrel is housed in the imaging device main body other than during photographing is used. In the lens barrel, a shutter mechanism or a shutter device including a shutter mechanism and a diaphragm mechanism, and a plurality of lens holding frames each holding a plurality of lens groups each including at least one lens, and a fixed portion on the base end side thereof The distance between the lens holding frame and the interference is reduced, and in order to eliminate such interference, a part of the lens holding frame is notched or a hole is provided in a part of the lens holding frame, An opening as a relief for preventing interference, that is, a relief opening is formed in the lens holding frame. As a result, harmful light that passes through the escape opening of the shutter device or the lens holding frame without passing through the optical path of the original lens is generated, and image degradation such as flare due to the harmful light occurs.

For example, as a technique for further reducing the thickness of the lens barrel, a retracting mechanism has been proposed that retracts some lens groups out of the optical axis when retracting the lens groups. The guide shaft for guiding the retractable lens holding frame for holding the retractable lens group during the movement related to the retracting of the lens group and the insertion on the optical axis is in the retracted state, and the shutter device and the other lens holding frame. Are arranged in the same space. At this time, at least one of the shutter device and the lens holding frame must be provided with a relief opening for preventing interference with the guide shaft.
When the lens barrel is extended to a state where it can be photographed, since the shutter device and the lens holding frame are extended toward the objective side, they do not interfere with the guide shaft, but from the objective side, for example, the first lens group. Incident light passes through the escape opening of the shutter device and the lens holding frame, and may reach an image sensor made up of, for example, a CCD (charge coupled device) solid-state image sensor.

  That is, such a lens barrel has a CCD solid-state imaging device 1, a low-pass filter (LPF) 2, a fixed frame 3, a first rotational movement frame 4, and a first rectilinear movement, as shown in a longitudinal section in FIG. Frame 5, second rotational movement frame 6, second linear movement frame 7, cam ring 8, third linear movement frame 9, front decoration part 10, first lens group 11, second lens group 12, and third lens A group 13, a fourth lens group 14, a shutter device 15 including a diaphragm mechanism, a retractable lens holding frame 16, a holding frame rotating shaft 17, a guide shaft 18, a base plate 19, and a fixed plate 20 are provided. In this case, the second lens group 12 includes a lens holding frame for holding it. The third lens group 13 is a retractable lens group that retracts out of the optical axis when retracted, and is retained by a retractable lens retaining frame 16, and the retractable lens retaining frame 16 rotates about the retaining frame rotation shaft 17. The third lens group 13 is moved between the optical axis and the retracted position. For example, the guide shaft 18 regulates and guides the position of the retractable lens holding frame 16 when the third lens group 13 is positioned on the optical axis and moves forward and backward along the optical axis. The lens holding frame of the second lens group 12 is provided with a relief opening 12a for inserting the guide groove 18 when retracted, and the shutter device 15 is also provided with a relief for inserting the guide groove 18 when retracted. An opening 15a is provided. The light incident from the first lens group 11 passes through the relief opening 12 a of the lens holding frame of the second lens group 12 and the relief opening 15 a of the shutter device 15, not the aperture opening of the shutter device 15, and the cam ring 8. The light is reflected on the inner diameter portion 8b and reaches the CCD image pickup device 1.

In this case, as shown in an example of the field transfer sequence of the CCD solid-state imaging device 1 in FIG. 8, after the mechanical shutter is closed, the charge accumulated in the CCD solid-state imaging device 1 is transferred during the exposure period. Since the light is incident even during the transfer, the image obtained as a result of imaging has a whitish pattern such as a flare or a horizontal stripe in the image due to the time shift of the CCD field transfer. May occur.
For example, Patent Document 1 (Japanese Patent Laid-Open No. 2006-79070), Patent Document 2 (Japanese Patent Laid-Open No. 2005-308443), and Patent Document 3 (Japanese Patent Laid-Open No. 2005-308443) disclose techniques for coping with harmful light passing through a relief opening such as a lens holding frame. Utility Model Registration No. 2565022). Patent Document 1 has a configuration in which a groove-shaped opening is shielded by fixing an elastically deformable light-shielding elastic tongue piece to a lens holding frame and bringing the light-shielding elastic tongue piece into contact with an inner peripheral surface of an outer lens barrel. It is shown. In Patent Document 2, a light-shielding piece is provided on a wall portion of a lens holding frame having a notch opening so as to be swingable about an axis substantially parallel to a plane perpendicular to the optical axis. A configuration is shown in which the protrusion is retracted substantially parallel to the optical axis direction, and in the photographing state, the light shielding piece is returned to the light shielding state substantially parallel to the surface where the optical axes intersect perpendicularly by the urging member. Patent Document 3 discloses a configuration in which a gap opening portion of a sliding fitting portion is shielded by providing a light-shielding member made of a thin-film light-shielding sheet having a large number of cuts radially formed on an outer peripheral edge portion.

JP 2006-79070 A JP 2005-30843 A Utility Model Registration No. 2565022

  However, all of the configurations shown in Patent Documents 1 to 3 utilize the guide member because the light-shielding member is bent and deformed and the rotation about the axis parallel to the surface where the optical axes intersect perpendicularly is used. It is not suitable for shielding a local relief opening such as a lens holding frame as a relief against the relief and a relief opening of a shutter device in a narrow part. Moreover, in the configuration as disclosed in Patent Document 1, there is a problem in durability because the elastically deformable member is pressed and deformed, and resistance to relative movement between the lens holding frame and the outer lens barrel is low. This will affect the driving force of the lens barrel. In the configuration as in Patent Document 2, the size of the light shielding piece affects the dimension of the lens barrel in the retracted state in order to retract the light shielding piece in the retracted state in a direction substantially parallel to the optical axis. End up. When the configuration of Patent Document 3 is adopted in a lens barrel as in the present invention, a load is always applied to the light shielding sheet in the retracted state of the lens barrel. If the retracted state is maintained for a long time, the light shielding sheet is plastic. There is a risk that the light shielding in the photographing state may be hindered.

The present invention has been made in view of the above-described circumstances, can be incorporated in a narrow part, achieves a light shielding configuration with excellent durability, and effectively prevents harmful light from reaching the image sensor. An object of the present invention is to provide a lens barrel and an imaging apparatus that can be prevented.
That is, the object of claim 1 of the present invention is to make it possible to effectively prevent harmful light from reaching the image sensor with a simple configuration without requiring a large amount of occupied space, and to improve durability. It is another object of the present invention to provide a lens barrel that can achieve an excellent light shielding structure.
An object of the present invention is to provide a lens barrel that can effectively and easily achieve opening and closing of the first relief opening formed in the shutter device.
The object of the third aspect of the present invention is to provide a lens barrel capable of achieving an effective light-shielding configuration even when there is a lens holding frame arranged close to the shutter device. There is.
A fourth object of the present invention is to provide a lens barrel that can effectively and easily achieve opening and closing of the first relief opening.
The object of the fifth aspect of the present invention is to provide a lens barrel capable of achieving an effective light shielding structure of the first relief opening and the second relief opening.
An object of claim 6 of the present invention is to provide a lens barrel capable of achieving an effective light shielding structure of the first relief opening, the second relief opening, and the third relief opening. It is to provide .

An object of claim 7 of the present invention is to provide a lens barrel that can be configured more compactly, in particular, with a space occupied by the shutter mechanism and the diaphragm mechanism being narrower.
An object of claim 8 of the present invention is that it is possible to effectively prevent harmful light from reaching the image pickup device with a simple configuration without requiring a lot of occupied space in the lens barrel, and is durable. An object of the present invention is to provide an image pickup apparatus that can achieve a light-shielding configuration that is excellent in performance.

In order to achieve the above-described object, a lens barrel according to the present invention described in claim 1 is provided.
A lens mirror in which at least a part of a plurality of lens groups is retracted and an imaging state in which imaging can be performed by moving at least a part of the plurality of lens groups to the objective side from a retracted state in which the plurality of lens groups are accommodated. A torso,
At least two lens holding frames that hold at least one of the lenses constituting the plurality of lens groups and the lens groups;
A shutter device having a shutter mechanism for opening and closing an imaging optical path, and disposed between the at least two lens holding frames;
A guide member for guiding a first lens holding frame, which is one of the at least two lens holding frames, installed in a region inside the outer shape of the shutter device;
A cam frame having a cam for moving a second lens holding frame disposed close to the objective side of the shutter device, which is one of the at least two lens holding frames;
With
The shutter device has a first relief opening formed so that the guide member can be inserted;
A light-shielding member that is in close contact with a plane that intersects the optical axis on the imaging plane side of the shutter device substantially perpendicularly and moves integrally with the shutter device in the optical axis direction is disposed,
The light shielding member is formed such that a flat light shielding part intersects the optical axis substantially perpendicularly, and the light shielding part is formed with a projecting part projecting in a direction parallel to the optical axis toward the imaging plane side, The tip of the projecting portion is fitted with the cam frame, and the cam frame rotates, so that the light shielding portion rotates about the optical axis and shields the first relief opening of the shutter device. It is a feature.
A lens barrel according to a second aspect of the present invention is the lens barrel according to the first aspect,
The light-shielding member includes a second relief opening.

A lens barrel according to a third aspect of the present invention is the lens barrel according to the first or second aspect,
The second lens holding frame has a third relief opening formed so that the guide member can be inserted therethrough.
A lens barrel according to a fourth aspect of the present invention is the lens barrel according to any one of the first to third aspects,
The light shielding member shields the first relief opening of the shutter device in the photographing state, and rotates when shifting from the photographing state to the retracted state, so that the first relief of the shutter device is provided. It is characterized by opening the opening.
The lens barrel according to the present invention described in claim 5 is the lens barrel according to any one of claims 2 to 4,
In the retracted state, the second relief opening is located corresponding to the first relief opening,
The guide member is characterized in that it enters the first escape opening and the second escape opening.

A lens barrel according to the present invention described in claim 6 is the lens barrel according to any one of claims 3 to 5,
In the retracted state, the second relief opening is located corresponding to the first relief opening and the third relief opening,
The guide member is characterized in that it enters the first escape opening, the second relief opening, and the third relief opening.
A lens barrel according to a seventh aspect of the present invention is the lens barrel according to any one of the first to sixth aspects,
The shutter device includes an aperture mechanism that limits a light flux in the imaging optical path.
An imaging apparatus according to an eighth aspect of the present invention includes the lens barrel according to any one of the first to seventh aspects.

According to the present invention, a lens barrel and an imaging apparatus that can be incorporated in a narrow part, achieve a light shielding configuration with excellent durability, and can effectively prevent harmful light from reaching the imaging element. Can be provided.
That is, according to the lens barrel of claim 1 of the present invention,
A lens mirror in which at least a part of a plurality of lens groups is retracted and an imaging state in which imaging can be performed by moving at least a part of the plurality of lens groups to the objective side from a retracted state in which the plurality of lens groups are accommodated. A torso,
At least two lens holding frames that hold at least one of the lenses constituting the plurality of lens groups and the lens groups;
A shutter device having a shutter mechanism for opening and closing an imaging optical path, and disposed between the at least two lens holding frames;
A guide member for guiding a first lens holding frame, which is one of the at least two lens holding frames, installed in a region inside the outer shape of the shutter device;
A cam frame having a cam for moving a second lens holding frame disposed close to the objective side of the shutter device, which is one of the at least two lens holding frames;
With
The shutter device has a first relief opening formed so that the guide member can be inserted;
A light-shielding member that is in close contact with a plane that intersects the optical axis on the imaging plane side of the shutter device substantially perpendicularly and moves integrally with the shutter device in the optical axis direction is disposed,
The light shielding member is formed such that a flat light shielding part intersects the optical axis substantially perpendicularly, and the light shielding part is formed with a projecting part projecting in a direction parallel to the optical axis toward the imaging plane side, The tip of the protrusion is fitted with the cam frame, and the cam frame rotates, so that the light shielding portion rotates about the optical axis, and the first relief opening of the shutter device is shielded from light. It is possible to effectively prevent harmful light from reaching the image sensor with a simple configuration without requiring a lot of occupied space, and it is possible to achieve a light shielding configuration with excellent durability. It becomes.

According to the lens barrel of the second aspect of the present invention, in the lens barrel of the first aspect, the second shield opening is provided in the light shielding member. The opening and closing of one escape opening can be achieved effectively and easily.
According to the lens barrel of claim 3 of the present invention, in the lens barrel of claim 1 or 2, the third relief opening is formed in the second lens holding frame so that the guide member can be inserted therethrough. By having the portion, it is possible to achieve an effective light shielding configuration even when there is a lens holding frame arranged close to the shutter device.
According to a lens barrel of a fourth aspect of the present invention, in the lens barrel of any one of the first to third aspects, the light shielding member is the first of the shutter device in the photographing state. It is particularly effective to open and close the escape opening by shielding the escape opening and rotating when shifting from the photographing state to the retracted state to open the first relief opening of the shutter device. Moreover, it can be easily achieved.

According to the lens barrel of claim 5 of the present invention, in the lens barrel of any one of claims 2 to 4, in the retracted state, the second relief opening is the first barrel. Located corresponding to the relief opening of
In particular, the guide member can achieve effective light shielding of the first escape opening and the second escape opening by entering the first relief opening and the second relief opening. it can.
According to a lens barrel of a sixth aspect of the present invention, in the lens barrel of any one of the first to fifth aspects, in the retracted state, the second relief opening is the first barrel. Corresponding to the relief opening and the third opening,
The guide member enters the first relief opening, the second relief opening, and the third opening, and in particular, the first relief opening, the second opening, and the third It is possible to achieve effective light shielding of the relief opening.
According to a lens barrel of a seventh aspect of the present invention, in the lens barrel of any one of the first to sixth aspects, the shutter device includes a diaphragm mechanism that restricts a light flux in the imaging optical path. By including, in particular, the occupied space by the shutter mechanism and the diaphragm mechanism can be made narrower and more compact.
According to the imaging device of claim 8 of the present invention, as the imaging optical system, the lens barrel according to any one of claims 1 to 7 is included, so that a large occupied space in the lens barrel is obtained. Therefore, it is possible to effectively prevent harmful light from reaching the image sensor with a simple configuration, and to achieve a light shielding configuration excellent in durability.

Hereinafter, based on an embodiment of the present invention, a lens barrel of the present invention will be described in detail with reference to the drawings.
1 to 6 show a configuration of a main part of a lens barrel used as an imaging optical system in a digital camera as an imaging apparatus according to an embodiment of the present invention. FIG. 1 is a half longitudinal sectional view showing the configuration of the lens barrel in the telephoto state, and FIG. 2 is a configuration of the lens barrel in the wide-angle state at the upper half and the configuration of the lens barrel in the retracted state at the lower half. FIG. 3 is a longitudinal sectional view showing the configuration of the lens barrel when the upper half is in the intermediate focal length state, and FIG. 3 is a longitudinal sectional view showing the configuration including the guide shaft portion of the lens barrel when the lower half is in the retracted state. 4 is a cross-sectional view showing the configuration of the lens barrel in the vicinity of the light-shielding member in the retracted state, FIG. 5 is a cross-sectional view of the configuration in the vicinity of the light-shielding member of the lens barrel in the wide-angle state, and FIG. It is a cross-sectional view showing a configuration in the vicinity of the light blocking member of the lens barrel in the state.

In the lens barrel shown in FIGS. 1 to 6, the same components as those in the conventional configuration shown in FIG. , First rotational movement frame 4, first linear movement frame 5, second rotational movement frame 6, second linear movement frame 7, cam ring 8, third linear movement frame 9, front decoration part 10, first 1 lens group 11, 2nd lens group 12, 3rd lens group 13, 4th lens group 14, shutter device 15 including a diaphragm mechanism, retractable lens holding frame 16, holding frame rotating shaft 17, guide shaft 18, base plate 19 The fixing plate 20 and the light shielding member 21 are provided.
Also in this case, the second lens group 12 includes a lens holding frame for holding it. The third lens group 13 is a retractable lens group that retracts out of the optical axis when retracted. The third lens group 13 is held by a retractable lens holding frame 16, and the retractable lens holding frame 16 pivots about the holding frame rotating shaft 17. The third lens group 13 is moved between the optical axis and the retracted position. For example, the guide shaft 18 regulates and guides the position of the retractable lens holding frame 16 when the third lens group 13 is positioned on the optical axis and moves forward and backward along the optical axis. The lens holding frame of the second lens group 12 is provided with a relief opening 12a for inserting the guide groove 18 when retracted, and the shutter device 15 also has a relief opening for inserting the guide groove 18 when retracted. A portion 15a is provided.

In this case, the light shielding member 21 is provided on the image sensor side of the shutter device 15. As shown in FIGS. 1 to 3, the light shielding member 21 is formed by forming a flat light shielding portion as a main body on a plane where the optical axes intersect substantially perpendicularly, and the optical axis on the image pickup element side of the shutter device 15 is substantially the same. Closely arranged on the perpendicular planes. As shown in FIG. 2, an arm portion 21a projecting in an arm shape in a direction parallel to the optical axis is formed on the flat light shielding portion of the light shielding member 21, and the most distal end of the arm portion 21a. Is formed with a concave portion. As shown in FIG. 2 and FIGS. 4 to 6, a convex portion 8 a formed so as to protrude from the cam ring 8 in a rib shape is fitted in the concave portion, and the cam ring 8 rotates around the optical axis. The rotation operation is transmitted from the convex portion 8a to the arm portion 21a via the concave portion, and the light shielding member 21 is also rotated around the optical axis.
The light shielding portion of the light shielding member 21 is formed in a substantially annular shape as shown in FIGS. 4 to 6, and at the outer peripheral edge, the relief opening 15 a of the shutter device 15 and the second lens group (lens holding frame) 12. The escape opening 12a is formed so as to shield the escape opening 12a and cut out a part of the periphery, and to open the escape openings 15a and 12a.

In the photographing state, as shown in FIGS. 5 and 6, respectively, the wide-angle state and the telephoto state, the periphery of the light-shielding portion of the light-shielding member 21 is the relief opening 15a of the shutter device 15 and the second lens holding frame (second lens group). ) 12 escape openings 12a are shielded. When moving from the photographing state as described above to the retracted state as shown in FIG. 4, the light shielding member 21 rotates, and the relief opening 21b is positioned corresponding to the relief openings 15a and 12a. The guide shaft 18 enters the relief openings 15a and 12a of the shutter device 15 and the second lens holding frame 12 through the relief opening 21b of the light shielding member 21, and can shift to the retracted state.
This makes it possible to prevent light incident from the first lens group 11 from reaching the CCD solid-state imaging device 1 from a portion other than the aperture opening of the shutter device 15. In this embodiment, the shutter device 15 and the light shielding member 21 can be moved integrally in the optical axis direction, as shown in FIGS. The engaging claws 15b are provided at three positions on the circumference at almost equal intervals. Although not clearly shown, the light shielding member is formed with a notch for escaping the engaging claw 15b at a position where the light shielding member 21 is assembled to the shutter device 15.

Therefore, with such a configuration, the light incident from the first lens group 11 can be used as the shutter device 15 such as the relief opening portion 12a of the lens holding frame of the second lens group 12 and the relief opening portion 15a of the shutter device 15. It is possible to achieve a lens barrel that can prevent the light from reaching the CCD image pickup device 1 from being reflected by the inner diameter portion 8b of the cam ring 8 through a portion other than the aperture opening. In the above description, the lens barrel according to the present invention is used to describe a digital camera as an imaging apparatus. However, the present invention is applied to other imaging apparatuses such as a portable information terminal having a camera function. May be.
Next, a lens barrel according to another embodiment related to the present invention will be described in detail with reference to the drawings.
An imaging apparatus such as a digital camera includes an imaging element, and a lens barrel including a plurality of lenses for forming an image on the imaging element and a lens driving device for moving the plurality of lenses to a predetermined position. In recent years, in compact cameras and the like, one or more rotating cylinders that rotate to advance and retract in the optical axis direction, one or more rectilinear guide cylinders that advance and retract in the optical axis direction without rotating, and a lens without rotating One or more lens holding cylinders that hold and advance and retract in the direction of the optical axis, are stored short when not in use, extend in the direction of the optical axis when in use, and hold each lens in place. Many lens barrels having a predetermined focal length are used.

Further, with the progress of miniaturization, there is a tendency that high accuracy is required for optical axis alignment of lenses. In order to increase the accuracy, it is necessary to maintain not only the accuracy between the lens holding frame and the lens but also the optical axis position shift of the rotating cylinder that drives the lens holding frame with high accuracy. The rotating cylinder can move by having a clearance with the relative moving object, that is, a clearance, and if this clearance is narrowed to increase accuracy, malfunctions and extra energy loss may occur. It will be generated. Furthermore, in order to immediately enter the shooting state when the camera is turned on, it is necessary to move the lens barrel from the retracted state to the shooting state at high speed. If the clearance is narrowed, the frictional resistance increases. It becomes difficult to move at high speed.
In order to solve such an optical axis shake of the lens, there is a type that uses a magnet to hold the auxiliary lens attached and detached. Further, a magnet is provided on the lens holding frame, and the magnet's attractive force is applied to the metal housing of the motor provided in the guide means that holds the lens holding frame so as to be movable in the direction of the optical axis, thereby intersecting the optical axis. It is also considered to prevent the movement in the direction and smooth the operation. However, with this method, energy is required even at locations where the lens holding frame is always urged and the lens optical axis does not need to be aligned. Also, this method cannot effectively remove the backlash when the lens holding frame rotates because it receives a force from one magnet.

Therefore, the rotating cylinder is urged by the magnetic attractive force in the photographing state, so that the optical axis can be accurately aligned in the photographing state, and the magnetic attractive force is lost in the operation in the non-photographing state. Thus, it is the lens barrel according to this embodiment that makes it possible to effectively prevent energy loss during operation.
That is, the lens barrel as the first aspect according to this embodiment is
A lens group that can be photographed by forming an image on the imaging surface;
One or more lens holding frames for holding at least one of the lens groups;
A lens driving cylinder capable of moving the lens holding frame to a predetermined position in the optical axis direction by holding and rotating the lens holding frame;
The lens group, the lens holding frame, and a fixed cylinder that holds the lens driving cylinder,
In the lens barrel having one or more rotating cylinders that rotate to enable the lens holding frame to move forward and backward,
A magnetic body is provided in a rear part of the rotating cylinder held by the fixed cylinder, a member for generating at least two magnetic forces is provided in a front part of the fixed cylinder, and the member for generating the magnetic force is provided near the member for generating the magnetic force. The rotating cylinder forms a biasing surface that is biased by magnetic force,
When the rotating cylinder moves forward, an attractive force is generated on the magnetic body in a direction perpendicular to the optical axis direction, and when the rotating cylinder is urged against the urging surface by the attractive force, the center of the imaging surface It is characterized in that the shaft and the central axis of the rotating cylinder coincide with each other.

The lens barrel of the first aspect performs optical axis alignment by generating an attractive force by magnetic force only when the rotating cylinder moves forward, and the rotating cylinder is urged by the urging surface. is there.
The lens barrel as a second aspect according to this embodiment is the lens barrel according to the first aspect,
The rotating barrel can move in the direction of the optical axis while rotating from the shortened position to the front of the shooting area, and only rotates in the shooting area, and depends on the magnetic body and the member that generates magnetic force. It is characterized by being arranged so that the suction force is maximized in the imaging region.
The lens barrel of the second aspect generates an attractive force due to magnetic force in an imaging region where optical axis alignment is required, and an attractive force due to magnetic force between a shortened position where no optical axis alignment is necessary and the imaging region. Prevents the loss of energy for rotating the rotating cylinder.

A lens barrel as a third aspect according to this embodiment is the lens barrel according to the first aspect or the second aspect.
The member that generates the magnetic force is composed of a magnet.
The lens barrel of the third aspect makes it possible to perform optical axis alignment with high accuracy using an inexpensive member.
A lens barrel as a fourth aspect according to this embodiment is the lens barrel according to the first aspect or the second aspect.
The member for generating the magnetic force is composed of an electromagnet.

  The lens barrel according to the fourth aspect can easily perform the control of aligning the optical axis only when necessary, and can suppress energy loss when the optical axis alignment is unnecessary. It is.

The lens barrel as a fifth aspect according to this embodiment is the lens barrel according to the fourth aspect,
It is characterized in that it is energized only during imaging to generate a magnetic force.
In the lens barrel of the fifth aspect, the optical axis is aligned only in the photographing state, and in other states, it is possible to suppress the energy loss in operation by giving the rotating cylinder backlash.
An imaging apparatus such as a camera as a sixth aspect according to this embodiment includes a lens barrel according to any one of the first to fifth aspects.
The image pickup apparatus according to the sixth aspect can obtain high image quality and suppress energy loss.
Next, specific embodiments of the lens barrel according to another embodiment related to the present invention will be described in detail.

9 to 16 show the configuration of the main part of a lens barrel used as an imaging optical system in a digital camera as an imaging apparatus. FIG. 9 is a longitudinal sectional view showing the configuration of the lens barrel in an imaging state in which the upper half is extended and the electromagnet is energized, and the lower half is a configuration of the lens barrel in the retracted state. 10 is a detailed view of the main part of FIG. 9, FIG. 11 is a longitudinal sectional view showing the configuration of the lens barrel in a non-imaging state in which the lens barrel is extended and the electromagnet is de-energized, and FIG. FIG. 13 is a longitudinal sectional view showing the configuration of the lens barrel in the middle of storage, and FIG. 14 is a diagram for explaining the first rotation moving frame and the fixed frame, which are the main parts of the lens barrel. FIG. 15 is an exploded perspective view, FIG. 15 is a schematic cross-sectional view showing the positional relationship between the first rotary moving frame and the electromagnet when the electromagnet is energized, and FIG. 16 is the first rotary moving frame and the electromagnet when the electromagnet is deenergized. It is a typical cross-sectional view which shows the arrangement | positioning relationship.
In the lens barrel shown in FIGS. 9 to 16, the same components as those in FIG. 1 are denoted by the same reference numerals, and a CCD solid-state imaging device 1, a low-pass filter (LPF) 2, a fixed frame 3, 1 rotational movement frame 4, first linear movement frame 5, second rotational movement frame 6, second linear movement frame 7, cam ring 8, third linear movement frame 9, front decoration part 10, first lens A group 11, a second lens group 12, a third lens group 13, a fourth lens group 14, a shutter device 15 including a diaphragm mechanism, an engagement pin 30, a magnetic ring 31, an electromagnet 32, and an abutting member 33 are provided. .

  The basic configuration in the embodiment shown in FIGS. 9 to 16 is that the first lens group 11 is held by a third rectilinear movement frame 9 integrated with the first lens holding frame, and the third rectilinear movement is performed. The moving frame 9 is moved by the second rotating moving frame 6 via the cam follower 9a of the third rectilinear moving frame 9 engaged with a cam groove provided on the inner peripheral surface of the second rotating moving frame 6. Is retained. A groove is fitted on the inner peripheral surface of the third rectilinear moving frame 9 so that the second rectilinear moving frame 7 is relatively rectilinearly movable, and the second rectilinear moving frame 7 is rotated second. The key groove 6a of the second rotational movement frame 6 and the second rectilinear movement frame 7 are arranged in a plane perpendicular to the optical axis direction so as to be rotatable relative to the frame 6 and integrally move in the optical axis direction. The key portion 7a is engaged. Thus, the third rectilinear movement frame 9 can move along the cam groove provided on the inner peripheral surface of the second rotation movement frame 6 when the second rotation movement frame 6 rotates. The second rotational movement frame 6 is fitted to the helicoid 5b provided on the inner peripheral surface of the first linear movement frame 5 by the helicoid 6b, and the second linear movement frame 7 is arranged in the optical axis direction. The rectilinear key part 7b of the second rectilinear movement frame 7 is fitted in the rectilinear guide groove 5b provided on the inner peripheral surface of the first rectilinear movement frame 5 so that the rectilinear movement can be performed along the rectilinear movement. .

The first rotational movement frame 4 is engaged with an engagement pin 30 so as to be able to rotate integrally with the second rotational movement frame 6, and is integrated with the first rectilinear movement frame 5 in the optical axis direction. The key groove 4a of the first rotational movement frame 4 is engaged with the key portion 6a of the first rectilinear movement frame 6 on a plane perpendicular to the optical axis direction so that it can be relatively rotated. Thus, as the first rotational movement frame 4 rotates, the second rotational movement frame 6 advances and retreats while rotating along the helicoid provided on the inner diameter of the first rectilinear movement frame 5. The second rectilinear moving frame 7 is allowed to go straight without rotating integrally with the second rotating moving frame 6 in the optical axis direction. The first rotational movement frame 4 is helicoidally fitted to the inner peripheral surface of the fixed frame 3 holding the CCD image pickup device 1, and the first straight movement frame 6 is an inner part of the straight movement key portion 6 b and the fixed frame 3. The peripheral surface engages with a straight guide groove 3a provided along the optical axis direction. The fixed frame 3 is provided with a motor and a plurality of gears for driving the first rotational movement frame 4, and is engaged with the first rotational movement frame 4. As a result, the rotational force received from the motor rotates the first rotational movement frame 4 via the gear, and the first linear movement frame 5, the second rotational movement frame 6 and the second linear movement frame 7 are moved. Thus, the third rectilinear movement frame 9 holding the first lens group 11 can be advanced and retracted in the optical axis direction.
The third lens group 13 and the fourth lens group 14 are held by a holding frame rotating shaft 17 and a guide shaft 18 provided on the fixed frame 3, and rotate around the holding frame rotating shaft 17 and are guided by the guide shaft 18. It is possible to move forward and backward along the optical axis along the axis.

The first rotational movement frame 4 and the first rectilinear movement frame 5 are moved forward and backward in the optical axis direction with respect to the fixed frame 3, and the helicoid outermost diameter portion of the first rotational movement frame 4 and the first rectilinear movement. The straight key part of the frame 5 has a certain clearance or more. This clearance makes it possible to rotate and move the rotational movement frame without energy loss.
In this case, a magnetic ring member 31 is provided at the base end portion of the first rotational movement frame 4, and the first rotational movement frame 4 is extended to the fixed frame 3 when the first rotational movement frame 4 is extended to the imaging region. Two electromagnets 32 are provided at positions facing the ring member 31 of the one rotational movement frame 4 and at an angular interval of about 120 ° with the optical axis direction as the center. When the electromagnet 32 is energized, an electromagnetic force acts between the ring member 31 of the rotational movement frame 4 and the electromagnet 32 and an attractive force acts between the ring member 31. At this time, two abutting members 33 that abut on the electromagnet side are respectively provided between the ring member 31 of the rotational movement frame 4 and the two electromagnets 32. At this time, when the electromagnet 32 is energized and attracted via the contact member 33, the central axis of the first rotational movement frame 4 coincides with the optical axes of the third lens group 13 and the fourth lens group 14. The contact member 33 is arranged so as to do this.

The electromagnet 32 is energized, energized, and excited at the same time as a release button provided in a camera as an imaging device is pressed, for example. This magnetic force causes an attractive force to act on the ring member 31 of the first rotational movement frame 4, and the first rotational movement frame 4 is urged toward the electromagnet 32 with the abutting member 33 interposed therebetween, thereby causing the first rotational movement. The central axis of the frame 4 coincides with the optical axes of the third lens group 13 and the fourth lens group 14. This makes it possible to obtain high-performance image performance by matching the optical axes during shooting. On the other hand, when the first rotary moving frame 4 is rotated and zoomed and stored (or started), the electromagnet 32 is not energized, and the first rotary moving frame 4 maintains clearance so that it is driven without energy loss due to friction. It becomes possible to do.
As described above, when the first rotational movement frame 4 is in the photographing state, it is pressed toward the electromagnet 32 by the attractive force based on the magnetic force of the electromagnet 32, so that the optical axis can be accurately aligned in the photographing state. In the photographing state, the electromagnet 32 is de-energized and the attractive force due to the magnetic force disappears, so that it is possible to prevent energy loss during operation.
Next, lens barrels according to other embodiments related to the present invention will be described in detail with reference to the drawings.

In an imaging device such as a digital camera, a buffer member is provided on a lens barrel as a countermeasure against vibration as the performance of a photographing lens such as a zoom lens capable of changing a focal length is improved and the size is reduced according to user requirements. There is something provided. However, in this case, there is a problem that the shape becomes large because of the double structure of the lens frame and the lens frame protection member. Further, since the buffer member moves so as to move when an external force or the like is applied, it is very difficult to attach the lens frame protection member and the buffer member.
On the other hand, there is a case where the photographer unconsciously presses the extended lens barrel in the photographing enabled state to move the lens barrel to the storage side, and the lens barrel is damaged. In addition, the lens barrel may be unexpectedly vibrated, resulting in shooting with a focus failure.
This embodiment provides a lens control device and an imaging device that can prevent the lens barrel from being damaged and that can be easily assembled. In addition, the lens control device and the imaging device according to this embodiment can automatically return even when a focus failure due to vibration or the like occurs.

That is, the lens control device as the first aspect according to this embodiment is
In a lens control device for controlling a lens barrel provided with a DC motor as a drive source for driving the lens and the lens barrel frame,
Short brake control is performed when the DC motor is stopped, and the short brake control is continued without turning off the power thereafter.
The lens control device as the second aspect according to this embodiment is
As a drive source for driving the lens and lens barrel frame, a direct current motor, a lens barrel provided with a photodetector and a light shielding member for detecting rotation of the direct current motor, a central processing unit, a motor control drive A lens control device comprising:
When the detector detects the rotation of the DC motor without a DC motor drive command from the central processing unit, short brake control is performed for a certain period of time.
The lens control device as the third aspect according to this embodiment is
As a drive source for driving the lens and lens barrel frame, a direct current motor, a lens barrel provided with a photodetector and a light shielding member for detecting rotation of the direct current motor, a central processing unit, a motor control drive A lens control device comprising:
When the detector detects the rotation of the DC motor without a DC motor drive command from the central processing unit, the lens barrel is reset after performing a short brake control on the DC motor for a certain period of time. It is a feature.

An imaging apparatus such as a camera as a fourth aspect according to this embodiment is
As a drive source for driving the lens and lens barrel frame, a direct current motor, a lens barrel provided with a photodetector and a light shielding member for detecting rotation of the direct current motor, a central processing unit, a motor control drive In an imaging device comprising means and a shake detection means for detecting a shake amount,
When the shake detecting means detects a value larger than a certain threshold value, the DC motor is short brake controlled for a certain period of time.
An imaging apparatus such as a camera as a fifth aspect according to this embodiment
As a drive source for driving the lens and lens barrel frame, a direct current motor, a lens barrel provided with a photodetector and a light shielding member for detecting rotation of the direct current motor, a central processing unit, a motor control drive In an imaging device comprising means and a shake detection means for detecting a shake amount,
When the blur detecting means detects a value larger than a certain threshold value, the lens barrel is reset after performing a short brake control on the DC motor for a certain period of time.
Such a lens control device and an imaging device can prevent damage without incurring a cost increase even if the photographer carelessly presses it with his hand.

Next, specific embodiments of the lens control device according to other embodiments related to the present invention will be described in detail.
That is, FIG. 17 shows a first configuration of a lens control device according to another embodiment related to the present invention. In FIG. 17, the lens control device includes a lens barrel 50, a central processing unit 61, and motor driving means 62. The lens barrel 50 includes a DC motor 51, lens driving means 52, and a detection device 53.
The lens barrel 50 includes a DC motor 51 as a drive source for driving a lens and the like, and the lens drive means 52 is configured to drive the lens barrel frame and the lens via a gear mechanism.
For example, when the photographer unintentionally presses the lens barrel 50 with his / her hand in the photographing ready state extended to the subject side, for example, the telephoto side photographing state, the lens barrel 50 tilts from the lens barrel frame. The rotational force is transmitted to the DC motor 51 through the gear mechanism, and the DC motor 51 may rotate and the lens barrel frame may move to the storage side.

Therefore, when the direct current motor 51 is rotated a little, the direct current motor is rotated by a detection device 53 which is a motor rotation detection means comprising a light shielding means installed on the output shaft of the direct current motor 51 and a photodetector for detecting this. It is possible to detect. As a result, when the rotation of the motor 51 is detected, an instruction to short brake the DC motor 51 is issued from the central processing unit (CPU) 61, and the motor driving means 62 can short-circuit the terminals of the DC motor 51. It is clear from the configuration of the DC motor 51 that the torque for rotating the DC motor 51 becomes larger when the terminals of the DC motor 51 are free and when the terminals are short-circuited. is there.
As a result, when the rotation detection means of the DC motor 51 detects rotation, the terminals of the motor 51 are instantaneously short-circuited, increasing the amount of force required to move the lens barrel to the storage side and moving to the storage side. It becomes possible to prevent automatically. In this way, it is possible to prevent the lens barrel from being damaged. Further, when the hand is pushed a little, the focus position is also shifted. Therefore, after a short brake of the DC motor 51, a focus failure occurs by performing a reset operation to return the lens barrel 50 to the normal position. Can also be prevented.

  FIG. 18 shows a second configuration of the lens control apparatus according to another embodiment related to the present invention. In FIG. 18, the same components as those in FIG. 17 are denoted by the same reference numerals as those in FIG. 17, and in addition to the lens barrel 50, the central processing unit 61, and the motor driving means 62, vibrations such as camera shake are detected. A shake detecting means 71 is provided. The lens barrel 50 also includes a DC motor 51, lens driving means 52, and a detection device 53 in this case.

  As shown in FIG. 18, an imaging apparatus that performs camera shake correction such as camera shake includes a camera shake detection unit 71 for detecting a camera shake amount. Since there is a large difference in the output value of the shake detection means 71 when a normal shake amount and a shock are applied, it is possible to determine that a shock has been applied without determining a shake if it exceeds a certain threshold value. Is possible. When an impact is applied to the lens barrel 50, there is a high possibility that a focus failure will occur. Therefore, even when it is detected that the shake detection means 71 is above a certain threshold, the terminals of the DC motor 51 are short-circuited. It becomes possible to prevent the movement of the body frame, and it is possible to avoid a focus failure by resetting the lens barrel 50 thereafter.

It is a longitudinal cross-sectional view which shows typically the structure of the lens barrel in the telephoto state according to one embodiment of this invention. The upper half is a longitudinal sectional view schematically showing the configuration of the lens barrel according to the embodiment of FIG. 1 in the wide-angle state, and the lower half is a longitudinal sectional view schematically showing the configuration in the retracted state. . The upper half is a longitudinal sectional view schematically showing the configuration of the lens barrel according to the embodiment of FIG. 1 in the intermediate focal length state, and the lower half is schematically showing the configuration including the vicinity of the guide shaft in the retracted state. FIG. It is a cross-sectional view which shows typically the structure of the light-shielding member vicinity in the retracted state of the lens barrel according to embodiment of FIG. It is a cross-sectional view which shows typically the structure of the light-shielding member vicinity in the wide angle state of the lens barrel according to embodiment of FIG. It is a cross-sectional view which shows typically the structure of the light-shielding member vicinity in the telephoto state of the lens barrel according to embodiment of FIG. It is a longitudinal cross-sectional view which shows the structure of the conventional lens barrel typically. It is a timing chart which shows typically an example of a field transfer sequence in a CCD solid-state image sensor. It is a figure according to other embodiment of this invention, the upper half shows the structure of the lens barrel in the imaging state in which the lens barrel is extended and the electromagnet is urged, and the lower half is in the retracted state It is each a longitudinal cross-sectional view which shows the structure of a lens barrel. FIG. 10 is a detailed view of a main part of FIG. 9. FIG. 10 is a longitudinal sectional view showing the configuration of the lens barrel in a non-imaging state in which the lens barrel is extended and the electromagnet is de-energized in the embodiment of FIG. 9. It is detail drawing of the principal part of FIG. FIG. 10 is a longitudinal sectional view showing a configuration of a lens barrel in the middle of accommodation in the embodiment of FIG. 9. FIG. 10 is an exploded perspective view for explaining a first rotation moving frame and a fixed frame, which are main parts of the lens barrel, in the embodiment of FIG. 9. FIG. 10 is a schematic cross-sectional view showing the positional relationship between the first rotational movement frame and the electromagnet when the electromagnet is energized in the embodiment of FIG. 9. FIG. 10 is a schematic cross-sectional view showing the positional relationship between the first rotational movement frame and the electromagnet when the electromagnet is de-energized in the embodiment of FIG. 9. It is a block diagram which shows typically the 1st structure of the lens control apparatus according to other embodiment of this invention. It is a block diagram which shows typically the 2nd structure of the lens control apparatus according to other embodiment of this invention.

Explanation of symbols

1 CCD solid-state image sensor 2 Low-pass filter (LPF)
DESCRIPTION OF SYMBOLS 3 Fixed frame 4 1st rotation movement frame 5 1st rectilinear movement frame 6 2nd rotation movement frame 7 2nd rectilinear movement frame 8 Cam ring 9 3rd rectilinear movement frame 10 Front decoration part 11 1st lens group 12 Second lens group 13 Third lens group 14 Fourth lens group 15 Shutter device including aperture mechanism 16 Retraction lens holding frame 17 Holding frame rotating shaft 18 Guide shaft 19 Base plate 20 Fixing plate 21 Light shielding member

Claims (8)

A lens mirror in which at least a part of a plurality of lens groups is retracted and an imaging state in which imaging can be performed by moving at least a part of the plurality of lens groups to the objective side from a retracted state in which the plurality of lens groups are accommodated. A torso,
At least two lens holding frames that hold at least one of the lenses constituting the plurality of lens groups and the lens groups;
A shutter device having a shutter mechanism for opening and closing an imaging optical path, and disposed between the at least two lens holding frames;
A guide member for guiding a first lens holding frame, which is one of the at least two lens holding frames, installed in a region inside the outer shape of the shutter device;
A cam frame having a cam for moving a second lens holding frame disposed close to the objective side of the shutter device, which is one of the at least two lens holding frames;
With
The shutter device has a first relief opening formed so that the guide member can be inserted;
A light-shielding member that is in close contact with a plane that intersects the optical axis on the imaging plane side of the shutter device substantially perpendicularly and moves integrally with the shutter device in the optical axis direction is disposed,
The light shielding member is formed such that a flat light shielding part intersects the optical axis substantially perpendicularly, and the light shielding part is formed with a projecting part projecting in a direction parallel to the optical axis toward the imaging plane side, The tip of the projecting portion is fitted with the cam frame, and the cam frame rotates, so that the light shielding portion rotates about the optical axis and shields the first relief opening of the shutter device. Characteristic lens barrel.   The lens barrel according to claim 1, wherein the light shielding member includes a second relief opening.   3. The lens barrel according to claim 1, wherein the second lens holding frame has a third relief opening formed so that the guide member can be inserted therethrough. 4.   The light shielding member shields the first relief opening of the shutter device in the photographing state, and rotates when shifting from the photographing state to the retracted state, so that the first relief of the shutter device is provided. The lens barrel according to any one of claims 1 to 3, wherein the opening is opened. In the retracted state, the second relief opening is located corresponding to the first relief opening,
5. The lens barrel according to claim 2, wherein the guide member enters the first relief opening and the second relief opening. 6. In the retracted state, the second relief opening is located corresponding to the first relief opening and the third relief opening,
The said guide member penetrates into the said 1st escape opening part, the said 2nd relief opening part, and the said 3rd relief opening part, The any one of Claims 3-5 characterized by the above-mentioned. Lens barrel.   The lens barrel according to claim 1, wherein the shutter device includes a diaphragm mechanism that restricts a light flux of the imaging optical path.   An imaging apparatus comprising the lens barrel according to any one of claims 1 to 7 as an imaging optical system.

Images