JP2020154296A - Imaging device having hand-shake correction function - Google Patents

Abstract

To provide an imaging device having folded optics, provided with an anti-shake mechanism without increasing the size of the device.SOLUTION: An optical system with reflecting members that bend an optical axis comprises, from an object side, a first reflecting member, an imaging lens group, a second reflecting member, and an imaging element. The optical system performs a hand-shake correction by rotating, about rotation axes, a reflecting surface of the second reflecting member having a narrowed effective range, one of the rotation axes being perpendicular to a plane defined by an optical axis of the imaging lens group and an optical axis reflected by the reflecting member, and the other one of the rotation axes being parallel with the reflected optical axis or parallel with the optical axis of the imaging lens group.SELECTED DRAWING: Figure 4

Description

The present invention relates to an imaging device with an image stabilization function.

With the rapid development of imaging technology, lens drive devices are widely applied in many imaging devices. The application of the lens driving device to various portable electronic devices such as mobile phones and tablet computers is particularly accepted by consumers.

The drive mechanism of the lens drive device adapted to ordinary portable electronic devices is generally formed by a coil and a permanent magnet, and the coil is fixed to the outer periphery of the image pickup lens frame. When a current is applied to the coil, the action of electromagnetic force allows the coil to focus by moving the imaging lens frame and moving along the optical axis of the lens. Further, when the user takes a picture while holding the electronic device by hand, it is possible to correct the shake of the lens driving device due to the shake by driving the lens in the direction perpendicular to the optical axis. However, for example, it is a small optical device to be mounted on a portable electronic device, and it is difficult to mount it on the portable electronic device as it is with a zoom optical system having a long optical length, and it is necessary to take a structure such as bending.
In an optical system using this bending structure, an image pickup lens arranged in front of and behind a prism or a mirror for bending a light beam can be used for vibration correction, but in portable electronic devices that are becoming smaller and smaller, these front and back By using the shake correction structure of the image pickup lens arranged in, there is a possibility that the total length of the bending optical system becomes long, and there is a possibility that a part of the shape must be projected.

Therefore, it is necessary to provide a new lens driving device that can solve the above problems.

Japanese Unexamined Patent Publication No. 2004-219930 Japanese Unexamined Patent Publication No. 2012-118336

The present invention has been made in view of the above problems, and an object of the present invention is to realize a space-saving anti-vibration mechanism without increasing the size of the image pickup device in the image stabilization of an image pickup device having a bending optical system. To do.

The object of the present invention has been realized as follows. In the following description, reference numerals and the like in the drawings are added in parentheses to facilitate understanding of the invention, but each component of the present invention is not limited to those added. It should be widely interpreted to the extent that a person skilled in the art can technically understand it.

The present invention is characterized in that it has the following configuration in an image pickup apparatus that causes an optical element constituting the image pickup optical system to perform an image shake suppression operation in response to a shake applied to the image pickup optical system. As the optical elements of the imaging optical system, a first reflective member that reflects light incident from the object side along the first optical axis in the direction along the second optical axis, and a first reflective member that reflects the light beam incident along the first optical axis in the optical axis direction from this reflective member On the other hand, it has an image pickup lens group located on the image plane side and a second reflection member that reflects the light beam passing through the image pickup lens group in the direction along the third optical axis. The first reflective member is supported by the support member, and the imaging lens group is supported by the movable member. The second reflective member is supported by two movable members, and each movable member forms an axis perpendicular to the plane formed by the optical axis of the imaging lens group and the optical axis reflected by the second reflective member. It is possible to rotate the reflecting member with an axis parallel to the optical axis of the imaging lens group or an axis parallel to the reflected optical axis as a rotation axis.
An electromagnetic actuator that gives a driving force to rotate the movable member is arranged in the two movable members, and an image shake suppression operation is performed according to the shake applied by the imaging optical system.
When the electromagnetic actuator is a voice coil motor having a permanent magnet and a coil, the electromagnetic actuator support portion of the movable member supports either the permanent magnet or the coil.

As an advantage of the present invention, the anti-vibration mechanism of the bending type image pickup device of the present invention creates a reflective surface of the second reflective member whose effective range is narrowed by the optical axis of the imaging lens group and the optical axis reflected by the reflective member. Camera shake correction is performed by rotating the reflective member with an axis perpendicular to the plane to be formed, an axis parallel to the reflected optical axis, or an axis parallel to the optical axis of the imaging lens group as a rotation axis. By doing so, the correction movable range of the optical system can be minimized, so that the purpose of providing a more efficient anti-vibration mechanism in portable electronic devices that are becoming smaller can be achieved, and the quality of captured images can be improved. Get better.

It is a perspective view of the bending type image pickup apparatus of 1st Embodiment of this invention. It is a perspective view which excluded the front side cover plate and the rear side cover plate of the bending type image pickup apparatus of 1st Embodiment of this invention. It is sectional drawing which passed through the rotation axis AS1 of the bending type image pickup apparatus of 1st Embodiment of this invention, and was cut by the plane parallel to the 2nd optical axis. It is sectional drawing which passed through the rotation axis BS2 of the bending type image pickup apparatus of 1st Embodiment of this invention, and was cut by the plane parallel to the 3rd optical axis. It is a 1st holder perspective view of the bending type image pickup apparatus of 1st Embodiment of this invention. It is a 2nd holder perspective view of the bending type image pickup apparatus of 1st Embodiment of this invention. It is a perspective view of the vibration isolation unit of the bending type image pickup apparatus of 1st Embodiment of this invention. It is an exploded view of the vibration isolation unit of the bending type image pickup apparatus of 1st Embodiment of this invention. It is a perspective view of the bending type image pickup apparatus of the 2nd Embodiment of this invention. It is sectional drawing which passed through the rotation axis CS3 of the bending type image pickup apparatus of the 2nd Embodiment of this invention, and was cut by the plane parallel to the 3rd optical axis. It is sectional drawing which passed through the rotation axis AS1 of the bending type image pickup apparatus of the 2nd Embodiment of this invention, and was cut by the plane parallel to the 2nd optical axis. It is a portable electronic device (portable information terminal) provided with the bending type imaging device of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 to 4 are drawings showing the bending type imaging device 100 of the present invention.

1 to 8 show an image pickup apparatus and its components according to the first embodiment of the present invention.
The image pickup optical system of the bending type image pickup device 100 is composed of a first prism 21, an image pickup lens group 31, a second prism 41, and an image pickup element 51 from the objective side, and is a bending optical system that reflects light flux by the first and second prisms. It has become.

The light beam from the subject incident on the incident surface 21-a of the first prism 21 along the first optical axis O1 is directed along the second optical axis O2 by the reflecting surface 21-b of the first prism 21 (from the left). It is reflected by the right side) and is ejected from the injection surface 21-c. Subsequently, the luminous flux passes through the image pickup lens group 31 located on the second optical axis O2, enters the second prism 41 through the incident surface 41-a, and enters the second prism 41 by the reflecting surface 41-b of the second prism 41, and the third optical axis O3. It is reflected in the direction along the above (direction from the rear to the front) and emitted from the injection surface 41-c, and is imaged on the image pickup surface of the image pickup element 51.

The bendable image pickup device 100 has a housing 10 which is a base member. As shown in FIG. 8, the housing 10 has a box-shaped upper opening 11 opened upward, a box-shaped front opening 12 opened in the front-rear direction, and a rear opening 13. The first prism 21 is held in the box-shaped upper opening 11, and the lens frame 31 holding the image pickup lens group is supported by the two shafts 17 in the front opening 12, and can move forward and backward along the second optical axis O2. It is held in. The vibration isolation unit 60 holding the second prism 41 is rotatably supported by a shaft support member substantially parallel to the third optical axis O3 in the rear opening 13. The image sensor unit 50 is fixed in the direction perpendicular to the third optical axis O3 for the luminous flux emitted from the second prism 41.
The upper opening 11, the front opening 12, and the rear opening 13 of the housing 10 are closed by the first prism cover 14, the front cover plate 15, and the rear cover plate 16 (FIGS. 1 and 3).

The image pickup lens frame 32 that holds the image pickup lens group 31 is supported by two shafts 17 so as to be able to move straight along the second optical axis O2 in the box-shaped front opening 12, and is supported by the image pickup lens frame 32. An electromagnetic actuator composed of a permanent magnet 34 for focusing fixed to a side recess 33, a focusing coil 71 fixed to a hole 18 of a housing 10 facing the permanent magnet 34, and a flexible substrate 70 for mounting a hole sensor 72 for focusing. The focusing operation is performed by moving the image pickup lens frame 31 forward and backward along the second optical axis O2 by the driving force of the (voice coil motor).

The focus yoke 73 is provided on the surface side of the focus coil 71 that does not face the permanent magnet 34 for focus, and is fixed to the housing 10 like the focus coil 71.

The focus yoke 73 has a role of a magnetic spring for returning the permanent focus magnet 34 to a predetermined position when the image pickup lens group 31 moves due to a change in the focus position, and the image pickup lens group 31 and the image pickup lens frame 32 are combined. The role of urging the radial rattling of the supporting shaft 17 in one direction and the leakage magnetic flux of the focusing coil 71 are converged to improve the electromagnetic action efficiency of the focusing permanent magnet 34 and the focusing coil 71. It also has.

By providing the focusing hole sensor 72, the position of the focusing permanent magnet 34 can be detected, so that more accurate focusing position adjustment and accurate control in a situation where the focusing adjustment speed is important are realized. ing.

The focusing coil 71 may be a coil winding mounted and fixed on the housing 10, or may be a conductive pattern directly formed on the flexible substrate 70.

The bending type image pickup apparatus 100 includes a vibration isolation (image shake correction) unit 60 that reduces image shake on the image plane caused by vibration such as camera shake. The anti-vibration unit 60 rotates the second prism 41 with a rotation axis AS1 perpendicular to the plane including the second optical axis O2 and the third optical axis O3 and a rotation axis B S2 parallel to the third optical axis O3. It is configured to be rotatable as.

The second prism 41 is fixed to the first holder 81 by adhesion or the like. In addition, the permanent magnet A82 constituting the voice coil motor and the rotating shaft AS1 shaft hole supported by the second holder are made of metal. Bush 83 is press-fitted. This block will be referred to as a first holder block 80.

The first holder block 80 is pivotally supported by inserting the shaft 84 into the rotation shaft AS1 of the second holder 91. The shaft 84 is fixed to the second holder hole, and is set to a size that allows it to rotate smoothly with respect to the bush 83. Further, by inserting the pin 85 into the hole A86 of the first holder in this state, the movable range of the first holder block 80 in the rotation direction with respect to the second holder 91 is regulated.
In this case, the rotation axis BS2 is preferably as close as possible to the reflection surface 41-b of the second prism.

A flexible substrate 70 on which the anti-vibration coil A74 and the anti-vibration hole sensor A75 for position detection are mounted is further attached to the second holder 91, and the anti-vibration coil A74 and the anti-vibration hole sensor A75 are fixed at the positions shown in the drawings. A voice coil motor is configured together with the permanent magnet A82 of the first holder block 80. Further, an anti-vibration yoke A76 made of magnetic metal is attached to the back surface of the anti-vibration coil A74 of the flexible substrate 70, and a more predetermined position of magnetism with the permanent magnet A82 of the first holder block 80 ( In the embodiment, it acts as a magnetic spring held at the center of the moving range).

A permanent magnet B92 constituting a voice coil motor is fixed to the second holder 91, and a metal bush 93 is press-fitted into a hole of a rotating shaft BS2 shaft supported by a housing 10. This block will be referred to as a second holder block 90.

The second holder block 90 is inserted from the rear opening 13 of the housing 10 and is pivotally supported by inserting the shaft 94 into the rotation shaft BS2 shaft. The shaft 94 is fixed to the hole in the housing and is set to a size that allows it to rotate smoothly with respect to the bush 93. Further, by inserting the pin 95 into the hole B96 of the second holder 91 in this state, the movable range of the second holder block 90 in the rotation direction with respect to the housing 10 is restricted.

A flexible substrate 70 on which the vibration-proof coil B77 and the vibration-proof hole sensor B78 for position detection are mounted is further attached to the housing 10, and the vibration-proof coil B77 and the vibration-proof hole sensor B78 are fixed at the positions shown in the drawings. A voice coil motor is formed together with the permanent magnet B92 of the second holder block 90. Further, an anti-vibration yoke B79, which is a yoke made of magnetic metal and attracts the permanent magnet B92 of the electromagnetic actuator, is attached to the back surface of the anti-vibration coil B77 of the flexible substrate 70, and the second holder block 90 is permanently attached. It acts as a magnetic spring that holds the magnet at a more predetermined position (center of the moving range in the embodiment) of magnetism with the magnet B92.

The housing 10 has a groove 19 capable of holding the ball 61 for sliding the second holder block 90. A sliding surface is also formed on the opposite portion of the second holder 91, and the surface accuracy is set so that the second holder 91 can rotate smoothly like the sliding surface of the housing. The housing 10 and the second holder block 90 are urged by a tension spring 62 in a direction in which they hit each other against the ball 61, and the position in the horizontal direction with the rotation axis can be determined by the height of the ball. The purpose is to eliminate backlash due to manufacturing errors.
Further, the urging direction of the spring 62 coincides with the attraction direction of the permanent magnet B92 and the vibration-proof yoke B79 constituting the magnetic spring holding the second holder block 90, thereby enabling a more stable magnetic spring action. There is.

When the second prism 41 has a backlash component in a direction parallel to the second optical axis O2 or the third optical axis O3, the third optical axis O3 moves in parallel and image shake that cannot be controlled by camera shake correction occurs. It is conceivable that the focus shift may occur due to the change of the optical path length. Therefore, in this embodiment, it is essential to eliminate the backlash component in the horizontal direction with the rotation axis of the second holder block 90.
In the present invention, the second holder is spring-forced in a direction parallel to the rotation axis, and a ball is used for the sliding portion, so that loose play can be reliably removed with a low load.

9 to 11 show an image pickup apparatus according to a second embodiment of the present invention and its components.
The difference from the first embodiment is the direction of the rotation axis of the vibration isolation unit.
In the first embodiment, the rotation axis AS1 perpendicular to the plane including the second optical axis O2 and the third optical axis O3 and the rotation axis B S2 substantially parallel to the third optical axis O3 are used. In the embodiment, the rotation axis AS1 perpendicular to the plane including the second optical axis O2 and the third optical axis O3 and the rotation axis CS3 substantially parallel to the second optical axis O2.
The basics of the components are the same as those in the first embodiment, and even in this case, a space-saving anti-vibration mechanism can be realized without increasing the size of the imaging device, and the problem can be solved.

In the present embodiment, the second prism may be a mirror (not shown).

The above-described bending type imaging device 100 may be used in the imaging device 100 for a mobile information device 200 such as a so-called smartphone, a so-called feature phone, or a tablet device shown in FIG. 12, for example.

The above is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above-described embodiment, but is made by an engineer in this area based on the contents disclosed in the present invention. All equivalent modifications or modifications are included in the invention described in the claims of the present application.

10… Housing 11… Upper opening 12… Front opening 13… Rear opening 14… First prism cover 15… Front cover plate 16… Rear cover plate 17… Shaft 18… Hole 19… Groove 21… First Prism 21-a ... First prism incident surface 21-b ... First prism reflecting surface 21-c ... First prism ejection surface 31 ... Imaging lens group 32 ... Imaging lens frame 33 ... Recessed 34 ... Focusing permanent magnet 41 ... No. 2 prisms 41-a ... 2nd prism incident surface 41-b ... 2nd prism reflecting surface 41-c ... 2nd prism ejection surface 50 ... Imaging element unit 51 ... Imaging element 60 ... Anti-vibration unit 61 ... Ball 62 ... Spring 70 … Flexible substrate 71… Focus coil 72… Focus hole sensor 73… Focus yoke 74… Anti-vibration coil A
75 ... Anti-vibration hall sensor A
76 ... Anti-vibration yoke A
77 ... Anti-vibration coil B
78 ... Anti-vibration hall sensor B
79 ... Anti-vibration yoke B
80 ... 1st holder block 81 ... 1st holder 82 ... Permanent magnet A
83 ... Bush 84 ... Shaft 85 ... Pin 86 ... Hole A
90 ... 2nd holder block 91 ... 2nd holder 92 ... Permanent magnet B
93 ... Bush 94 ... Shaft 95 ... Pin 96 ... Hole B
100 ... Bending image pickup device 200 ... Portable information device O1 ... 1st optical axis O2 ... 2nd optical axis O3 ... 3rd optical axis S1 ... Rotating axis A
S2 ... Rotation axis B
S3 ... Rotation axis C

Claims (9)

In an imaging device that includes a reflective member having a reflective surface that bends the optical axis and corrects camera shake by rotating the reflective member.
The reflective member is arranged between the image pickup lens group and the image pickup element, and reflects the X axis, which is an axis perpendicular to the plane formed by the optical axis of the image pickup lens group and the optical axis reflected by the reflection member. A bending type image pickup apparatus characterized in that the reflection member is rotated around a Y axis, which is an axis parallel to the optical axis, and a Z axis, which is an axis parallel to the optical axis of the image pickup lens group. Anti-vibration mechanism. The reflective member is held by a first holding frame, and the first holding frame is held by a second holding frame that is rotatable around one of the X-axis, the Y-axis, and the Z-axis. The second holding frame is rotatably held by the base member around the remaining two axes of the X-axis, the Y-axis, and the Z-axis, and the first holding frame and the second holding frame are held. A first electromagnetic actuator for rotating the first holding frame is provided between the holding frames of the above, and the second holding frame is rotated between the second holding frame and the base member. The anti-vibration mechanism of the bending type imaging device according to claim 1, further comprising a second electromagnetic actuator for causing the vibration. The prevention of the bending type imaging device according to claim 2, wherein the first holding frame or the second holding frame has an urging means for removing backlash in the axial direction of the rotating shaft. Shaking mechanism. The vibration isolation of the bending type imaging device according to any one of claims 1 to 3, wherein a ball is used for the sliding surface between the second holding frame and the base member in order to reduce friction. mechanism. The anti-vibration mechanism for a bending-type imaging device according to any one of claims 1 to 4, wherein the first electromagnetic actuator and the second electromagnetic actuator are voice coil motors. When the first holding frame has the urging means, the urging direction of the urging means is the same as the direction in which the permanent magnet of the first electromagnetic actuator and the yoke are attracted to each other.
When the second holding frame has the urging means, the urging direction of the urging means is the same as the direction in which the permanent magnet and the yoke of the second electromagnetic actuator are attracted to each other. The anti-vibration mechanism of the bending type imaging device according to any one of Items 1 to 5. The anti-vibration mechanism of the bending type imaging device according to any one of claims 1 to 6, wherein the reflecting member is a prism or a mirror. A camera comprising the anti-vibration mechanism of the bending type imaging device according to any one of claims 1 to 7. A portable electronic device comprising the camera according to claim 8.