JP2009058601A - Lens driving device, imaging device, and mobile terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a reliable lens driving device which increases driving force with low power consumption and is operated reliably, and to obtain an imaging device of low power consumption by comprising the lens driving device. <P>SOLUTION: When the lens driving device is seen in the section containing the optical axis of an image pickup lens group, a mirror cell, a coil, a magnet, and a yoke are arranged in this order from the optical axis to outside, an interval t (mm) between the coil and the magnet is formed to be 0.01≤t≤0.15, viscous fluid is interposed in the interval between the coil and the magnet, and the mirror cell is maintained in the optical-axis orthogonal direction by the viscous fluid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens driving device suitable for a small imaging device built in a portable terminal or the like.

  Conventionally, a small and thin imaging device is mounted on a small and thin portable terminal such as a mobile phone or a PDA (Personal Digital Assistant). As a result, not only voice information but also image information can be transmitted to remote places.

  Various types of image pickup apparatuses mounted on these mobile phones and PDAs have been proposed in which a sharp image is obtained by moving the image pickup lens group in the optical axis direction in accordance with the subject distance as well as the fixed focus method.

  As a lens driving device used in the imaging device as described above, a magnet and a coil that is fixed to the lens frame and moves together with the lens frame are arranged in a yoke whose cross section is bent in a U shape, and the coil is energized. There is known a lens driving device using a so-called voice coil motor that moves the lens frame in the optical axis direction of the imaging lens group by electromagnetic force generated in this manner.

In order to improve the impact resistance and vibration characteristics of the lens drive device using this voice coil motor, a viscous fluid is interposed around the leaf spring that supports the lens group, and the driving force is increased to improve the damping effect. In order to increase the magnetic field, there is one in which a magnetic fluid is interposed between a coil and a magnet (for example, see Patent Document 1).
JP 2006-195452 A

  However, in the lens driving device described in Patent Document 1, an increase in driving force by interposing a magnetic fluid between a coil and a magnet is about several percent, and a great effect cannot be obtained.

  In order to increase the driving force without increasing the power consumption, it is effective to make the distance between the coil and the magnet and the distance between the coil and the yoke closer. However, if these distances are too small, the coil and the magnet may come into contact with each other during movement, which causes a problem of malfunction.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to obtain a highly reliable lens driving device that increases driving force with low power consumption and operates reliably, and has low power consumption imaging by providing the lens driving device. The purpose is to obtain a device.

  The above object is achieved by the invention described below.

1. A lens frame that holds the imaging lens group; a coil that is formed integrally with the lens frame; a magnet that is disposed to face the coil; and a yoke that holds the magnet. A lens driving device in which a viscous fluid is interposed in a gap of the magnet, and the lens frame is moved in an optical axis direction of the imaging lens group by an electromagnetic force generated by supplying power to the coil. When the apparatus is viewed in a cross section including the optical axis of the imaging lens group, the lens frame, the coil, the magnet, and the yoke are arranged in this order from the optical axis to the outside, and the gap t (mm) between the coil and the magnet. )
0.01 ≦ t ≦ 0.15
The lens driving device is characterized in that the lens frame is held in the direction perpendicular to the optical axis by the viscous fluid.

2. A lens frame that holds the imaging lens group, a coil that is formed integrally with the lens frame, a magnet that is arranged to face the coil, and a magnet that is formed so as to sandwich the coil and that holds the magnet A viscous fluid is interposed in the gap between the coil and the magnet and in the gap between the coil and the yoke, and the coil and the lens frame are moved by the electromagnetic force generated by supplying power to the coil. A lens driving device that moves in the optical axis direction of the imaging lens group, wherein the gap between the coil and the magnet, and the gap t (mm) between the coil and the yoke,
0.01 ≦ t ≦ 0.15
The lens driving device is characterized in that the lens frame is held in the direction perpendicular to the optical axis by the viscous fluid.

3. A lens frame that holds the imaging lens group, an urging member that urges the lens frame in the optical axis direction, a coil that is integrally formed with the lens frame, and a magnet that is disposed to face the coil And a yoke for holding the magnet, and a viscous fluid is interposed in the gap between the coil and the magnet, and the lens frame is attached to the imaging lens group by electromagnetic force generated by supplying power to the coil. A lens driving device that moves in an optical axis direction, when the lens driving device is viewed in a cross section including the optical axis of the imaging lens group, the lens frame, the coil, the magnet, and the yoke Are arranged in order, the gap t (mm) between the coil and the magnet,
0.01 ≦ t ≦ 0.15
The lens driving device is characterized in that the lens frame is held in the direction perpendicular to the optical axis by the viscous fluid.

4). A lens frame that holds the imaging lens group, an urging member that urges the lens frame in the optical axis direction, a coil that is integrally formed with the lens frame, and a magnet that is disposed to face the coil And a yoke that holds the magnet and sandwiches the coil, and a viscous fluid is interposed in the gap between the coil and the magnet and in the gap between the coil and the yoke. A lens driving device that moves the coil and the lens frame in the optical axis direction of the imaging lens group by electromagnetic force generated by feeding power, the gap between the coil and the magnet, and the gap t ( mm)
0.01 ≦ t ≦ 0.15
The lens driving device is characterized in that the lens frame is held in the direction perpendicular to the optical axis by the viscous fluid.

  5). The lens driving device according to any one of claims 1 to 4, wherein the viscous fluid is a magnetic fluid.

  6). An imaging apparatus comprising: an imaging element disposed behind the imaging lens group; and the lens driving device according to any one of 1 to 5.

  A portable terminal comprising the imaging device according to 7.6.

  That is, when the present inventor looks at the lens driving device in a section including the optical axis of the imaging lens group, the lens frame, the coil, the magnet, and the yoke are arranged in this order from the optical axis toward the outside. By forming a gap between the coil and the magnet in the range of the above formula and filling the gap with a viscous fluid, the centering of the lens frame can be performed without requiring a support member for supporting the lens frame. It is an invention that was made possible and found.

  Further, in the case of having a yoke that holds the magnet and is formed so as to sandwich the coil, the gap between the coil and the magnet and between the coil and the yoke are formed in the gaps in the range of the above formula. The present invention has been made by finding that centering of a lens frame is possible without filling a viscous fluid and interposing it with a support member for supporting the lens frame.

  According to the present invention, it is possible to increase the driving force with low power consumption and operate reliably and to obtain a highly reliable lens driving device. By providing the lens driving device, an imaging device with low power consumption can be obtained. Can be obtained.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

  FIG. 1 is an external view of a mobile phone T that is an example of a mobile terminal that incorporates an imaging device S including a lens driving device of the present invention.

  In the mobile phone T shown in the figure, an upper casing 71 as a case having a display screen D and a lower casing 72 having an operation button P are connected via a hinge 73. The imaging device S is built below the display screen D in the upper casing 71, and is arranged so that the imaging device S can capture light from the outer surface side of the upper casing 71.

  Note that the position of the imaging device S may be arranged above or on the side of the display screen D in the upper housing 71. Of course, the mobile phone T is not limited to a folding type.

  FIG. 2 is a perspective view showing the outer surface of the imaging apparatus S according to the present embodiment.

  The outer surface of the image pickup apparatus S shown in FIG. 1 includes a substrate 52, an outer frame member 21, and a lid member 22. The lid member 22 has an opening. Reference numeral 10 denotes an imaging lens group.

(First embodiment)
FIG. 3 is a cross-sectional view of the imaging apparatus S according to the first embodiment. This figure shows a cross section taken along line FF including the optical axis O shown in FIG.

  In the imaging apparatus S illustrated in FIG. 3, an imaging element 51 and an imaging lens group 10 that guides a subject image to the photoelectric conversion unit of the imaging element 51 are arranged. As the image sensor 51, a CMOS type or CCD type image sensor is applied. An infrared light cut filter F is disposed between the image sensor 51 and the imaging lens group 10. The infrared light cut filter F is held by the outer frame member 21, and the outer frame member 21 is fixed to the substrate 52 holding the image sensor 51 with an adhesive.

  A large number of pads (not shown) are formed on the substrate 52 and are connected to the image sensor 51 via bonding wires W. Further, on the outside, although not shown, for example, a terminal for connection with an external substrate such as a control circuit of a portable terminal that is a host device including the imaging device S is formed.

  A lid member 22 is attached to the upper part of the outer frame member 21. A yoke 31 made of a magnetic material is assembled to the outer frame member 21, and a magnet 32 is assembled to the yoke 31.

  As shown in the figure, the magnet 32 has a polarity of N pole on the yoke side, S pole on the coil side, S pole on the yoke side, and N pole on the coil side along the optical axis. In the drawing, the surface side opposite to the subject-side coil is shown as N-pole and the surface side opposite to the image-side coil is shown as S-pole. In order to make such a magnet with a polarity arrangement, a magnet with two poles may be used, or it may be divided into 32A and 32B with a magnet with one pole, and connected and configured. Also good.

  The imaging lens group 10 is held by a lens frame 23. A coil 33 is assembled on the outer periphery of the lens frame 23 so as to face the magnet 32. That is, the coil 33 is movable together with the lens frame 23 that holds the imaging lens group 10. Note that the lens frame 23 may have a double structure of a lens frame that holds the imaging lens group 10 and a lens frame that holds the coil 33 so that focus adjustment at an infinite distance or a hyperfocal distance can be performed. Good.

  The coil 33 is composed of a coil 33A facing the magnet 32A and a coil 33B facing the magnet 32B among the magnets 32. In the drawing, the coil 33A facing the N pole and the coil 33B facing the S pole are driven at the time of driving. By supplying a current in the reverse direction, it is possible to generate a driving force in the same direction as the optical axis O direction.

  The driving principle of the voice coil motor is known and disclosed in Japanese Patent Application Laid-Open No. 2005-128392. However, driving force is generated by the magnetic force generated by supplying power to the coil 33 and the magnetic force of the magnet 32. It is something to be made.

  In the imaging device S of the first embodiment, the gap between the coil 33A and the magnet 32A, which are lens driving devices, and the gap between the coil 33B and the magnet 32B are set to the predetermined intervals described below. Is filled with a viscous fluid R, preferably a viscous fluid having magnetism.

  FIG. 4 is an enlarged view showing a state between the coil and the magnet of the lens driving device shown in FIG.

  As shown in FIG. 4, the coil 33 is formed by winding a winding 33s, and the gap t between the winding 33s closest to the magnet 32 and the magnet 32 is 0.01 mm or more and 0.15 mm. It is formed to be as follows. As shown in the figure, the gap t is a distance from a point closest to the outer shape magnet 32 of the winding 33s having a circular cross section. A viscous fluid R is filled and interposed in the gap between the coil and the magnet formed as described above.

  In this way, the gap between the coil and the magnet is formed to be 0.01 mm or more and 0.15 mm or less, and the gap 33 is filled with a viscous fluid R, preferably a viscous fluid having magnetism. A uniform gap with respect to the magnet 32 can be maintained on the outermost periphery of the magnet 32. Accordingly, the lens frame 23 is positioned substantially in the center with respect to the magnet 32 by the viscous fluid R without using a support member that supports the lens frame 23. Similarly, when the lens frame 23 is moved in the direction of the optical axis O by energization of the coil 33, it is similarly positioned at the approximate center by the viscous fluid R and operates reliably without using a support member. High reliability can be obtained.

  In other words, by setting the gap to the above range, the driving force can be increased with low power consumption, and by centering with the viscous fluid with the gap set to the above range, a leaf spring or the like for positioning and supporting the lens frame can be dispensed with. It is possible to obtain a highly reliable lens driving device that operates reliably without causing contact even when the lens group is moved.

(Second Embodiment)
FIG. 5 is a cross-sectional view of the imaging apparatus S according to the second embodiment. This figure also shows a cross section taken along line FF including the optical axis O shown in FIG.

  In the imaging apparatus S illustrated in FIG. 5, an imaging element 51 and an imaging lens group 10 that guides a subject image to the photoelectric conversion unit of the imaging element 51 are arranged. An infrared light cut filter F is disposed between the image sensor 51 and the imaging lens group 10. The infrared light cut filter F is held by the outer frame member 21, and the outer frame member 21 is fixed to the substrate 52 holding the image sensor 51 with an adhesive.

  A large number of pads (not shown) are formed on the substrate 52 and are connected to the image sensor 51 via bonding wires W. Further, on the outside, although not shown, for example, a terminal for connection with an external substrate such as a control circuit of a portable terminal that is a host device including the imaging device S is formed.

  A lid member 22 is attached to the upper part of the outer frame member 21. A yoke 31 made of a magnetic material is assembled to the outer frame member 21, and a magnet 32 is assembled to the yoke 31.

  The yoke 31 holds the magnet 32 and is formed so as to sandwich the coil 33 formed on the lens frame 23.

  The imaging lens group 10 is held by a lens frame 23. A coil 33 is formed between the magnet 32 and the yoke 31 on the outer periphery of the lens frame 23. That is, the coil 33 is movable together with the lens frame 23 that holds the imaging lens group 10. Note that the lens frame 23 may have a double structure of a lens frame that holds the imaging lens group 10 and a lens frame that holds the coil 33 so that focus adjustment at an infinite distance or a hyperfocal distance can be performed. Good.

  In the image pickup apparatus S of the second embodiment, the gap between the coil 33 and the magnet 32, which is a lens driving device, and the gap between the coil 33 and the yoke 31 are set at predetermined intervals described below. Is filled with a viscous fluid R, preferably a magnetic viscous fluid.

  6 is an enlarged view showing a state between the coil and the magnet and between the coil and the yoke of the lens driving device shown in FIG.

  As shown in FIG. 6, the coil 33 is formed by winding a winding 33 s, and the gap t between the winding 33 s closest to the magnet 32 and the magnet 32 is 0.01 mm or more and 0.15 mm. It is formed to be as follows. As shown in the figure, the gap t is a distance from a point closest to the outer shape magnet 32 of the winding 33s having a circular cross section. A viscous fluid R is filled and interposed in the gap between the coil and the magnet formed as described above.

  Similarly, the gap t between the winding 33s closest to the yoke 31 and the yoke 31 is formed to be 0.01 mm or more and 0.15 mm or less. As shown in the figure, the gap t is a distance from a point closest to the outer yoke 31 of the winding 33s having a circular cross section. The gap between the coil and the yoke formed as described above is filled with a viscous fluid R and interposed.

  Thus, the gap between the coil and the magnet and the gap between the coil and the yoke are formed to be 0.01 mm or more and 0.15 mm or less, and the gap is filled with a viscous fluid R, preferably a magnetic viscous fluid. By doing so, the coil 33 can be maintained and held in a uniform gap with respect to the magnet 32 and the yoke 31. Accordingly, the lens frame 23 is positioned substantially in the center with respect to the magnet 32 and the yoke 31 by the viscous fluid R without using a support member that supports the lens frame 23. Similarly, when the lens frame 23 is moved in the direction of the optical axis O by energization of the coil 33, it is similarly positioned at the approximate center by the viscous fluid R, so that it does not come into contact without using a support member and operates reliably. High reliability can be obtained.

  In other words, by setting the gap to the above range, the driving force can be increased with low power consumption, and by centering with the viscous fluid with the gap set to the above range, a leaf spring or the like for positioning and supporting the lens frame can be dispensed with. It is possible to obtain a highly reliable lens driving device that operates reliably without causing contact even when the lens group is moved.

  FIG. 7 is a flowchart showing an outline of an operation at the time of photographing of a portable terminal provided with an imaging device having the lens driving device according to the first and second embodiments. The flow shown in the figure shows the operation when the mobile terminal is set to the camera mode.

  In the flow shown in the figure, first, a button corresponding to the release button of the mobile terminal is operated and waits for being turned on (step S101).

  When a button corresponding to the release button of the portable terminal is turned on (step S101; Yes), the coil is energized so that the imaging lens group moves to the imaging element side (step S102). Thereby, regardless of the attitude of the mobile terminal, the imaging lens group is moved to the imaging element side shown in FIGS. 3 and 5, that is, in the abutting portion 21 t where the lens frame 23 is formed on the outer frame member 21. It comes into contact. In this state, the image sensor is driven to capture an image (step S103).

  Next, the coil is energized so that the imaging lens group moves toward the subject (step S104). This means that the coil is energized in the direction opposite to that in step S102. Thereby, irrespective of the attitude of the mobile terminal, the imaging lens group is moved to the subject side, that is, the lens frame 23 is separated from the abutting portion 21t and is placed on the abutting portion 22t formed on the lid member 22. It comes into contact. In this state, the image pickup device is driven to capture an image (step S105).

  Thereafter, the image captured in step S103 and the image captured in step S105 are evaluated and compared (step S106). In this evaluation and comparison, for example, each image is subjected to Fourier transform to detect the frequency, and the image having the higher frequency is regarded as an image with higher sharpness, that is, an image in focus. Note that the present invention is not limited to this, and evaluation and comparison based on contrast or the like may be performed.

  Next, the coil is energized so as to be at a position where an image with higher sharpness is obtained (step S107). As a result, the imaging lens group is set at a focused position.

  Thereafter, actual shooting is performed, an image is recorded (step S108), and shooting of one frame is completed.

  The above is the outline of the operation at the time of photographing of the portable terminal provided with the imaging device having the lens driving device according to the first and second embodiments.

(Third embodiment)
FIG. 8 is a cross-sectional view of an imaging apparatus S according to the third embodiment. This figure also shows a cross section taken along line FF including the optical axis O shown in FIG. Since the imaging apparatus S shown in the figure is the same in many parts as the imaging apparatus S shown in FIG. 3, in order to avoid duplication of explanation, the same reference numerals are given to the same functional members, and the parts different from FIG. Only the explanation will be given.

  The imaging apparatus S shown in FIG. 8 includes a biasing member that biases the lens frame 23 toward the imaging element. As shown in the figure, a coil spring 55 is provided between the lid member 22 and the lens frame 23. By this coil spring 55, the lens frame 23, that is, the imaging lens group 10 is urged toward the image sensor in the optical axis direction, and the lens frame 23 is in contact with the abutting portion 21t in a non-energized state. Further, the coil spring 55 only biases the lens frame 23 in the optical axis direction, and does not restrict the direction orthogonal to the optical axis of the lens frame 23.

  Also in the case of this example, the gaps between the coil 33A and the magnet 32A, which are lens driving devices, and between the coil 33B and the magnet 32B are the same as those shown in FIG. R, preferably filled with a viscous fluid having magnetism.

  That is, a gap t (see FIG. 4) between the winding 33s near the magnet 32 and the magnet 32 is formed to be 0.01 mm or more and 0.15 mm or less, and the viscous fluid R, preferably By interposing a viscous fluid having magnetism, a uniform gap can be maintained with respect to the magnet 32 on the outermost periphery of the coil 33.

  Accordingly, the lens frame 23 is positioned substantially in the center with respect to the magnet 32 by the viscous fluid R without using a support member that supports the lens frame 23. Similarly, when the lens frame 23 is moved in the direction of the optical axis O by energization of the coil 33, it is similarly positioned at the approximate center by the viscous fluid R and operates reliably without using a support member. High reliability can be obtained.

  In other words, by setting the gap to the above range, the driving force can be increased with low power consumption, and by centering with the viscous fluid with the gap set to the above range, a leaf spring or the like for positioning and supporting the lens frame can be dispensed with. It is possible to obtain a highly reliable lens driving device that operates reliably without causing contact even when the lens group is moved.

(Fourth embodiment)
FIG. 9 is a cross-sectional view of an imaging apparatus S according to the fourth embodiment. This figure also shows a cross section taken along line FF including the optical axis O shown in FIG. Since the imaging apparatus S shown in FIG. 5 is the same in many parts as the imaging apparatus S shown in FIG. 5, the same reference numerals are given to the same functional members to avoid duplication of explanation, and the parts different from FIG. Only the explanation will be given.

  The imaging apparatus S shown in FIG. 9 includes a biasing member that biases the lens frame 23 toward the imaging element. As shown in the figure, a coil spring 55 is provided between the lid member 22 and the lens frame 23. By this coil spring 55, the lens frame 23, that is, the imaging lens group 10 is urged toward the image sensor in the optical axis direction, and the lens frame 23 is in contact with the abutting portion 21t in a non-energized state. Further, the coil spring 55 only biases the lens frame 23 in the optical axis direction, and does not restrict the direction orthogonal to the optical axis of the lens frame 23.

  Also in the case of this example, the gap between the coil 33 and the magnet 32 and the gap between the coil 33 and the yoke 31 as the lens driving device are the same as those shown in FIG. Preferably, a viscous fluid having magnetism is filled and interposed.

  That is, the gap t (see FIG. 6) between the winding 33s closest to the magnet 32 and the magnet 32 is formed to be 0.01 mm or more and 0.15 mm or less. The gap between the coil and the magnet formed in this way is filled with a viscous fluid R and interposed.

  Similarly, the gap t between the winding 33s closest to the yoke 31 and the yoke 31 is formed to be 0.01 mm or more and 0.15 mm or less. The gap between the coil and the yoke formed in this way is filled with a viscous fluid R and interposed.

  Thus, the gap between the coil and the magnet and the gap between the coil and the yoke are formed to be 0.01 mm or more and 0.15 mm or less, and the gap is filled with a viscous fluid R, preferably a magnetic viscous fluid. By doing so, the coil 33 can be maintained and held in a uniform gap with respect to the magnet 32 and the yoke 31. Accordingly, the lens frame 23 is positioned substantially in the center with respect to the magnet 32 and the yoke 31 by the viscous fluid R without using a support member that supports the lens frame 23. Similarly, when the lens frame 23 is moved in the direction of the optical axis O by energization of the coil 33, it is similarly positioned at the approximate center by the viscous fluid R, so that it does not come into contact without using a support member and operates reliably. High reliability can be obtained.

  In other words, by setting the gap to the above range, the driving force can be increased with low power consumption, and by centering with the viscous fluid with the gap set to the above range, a leaf spring or the like for positioning and supporting the lens frame can be dispensed with. It is possible to obtain a highly reliable lens driving device that operates reliably without causing contact with the lens group movement.

  In the third and fourth embodiments, the coil spring is used as the biasing member for biasing the lens frame in the optical axis direction. However, the present invention is not limited to this, and a plate spring or the like is used. It may be biased in the optical axis direction. However, the biasing member shown in this example only biases the lens frame in the optical axis direction, and is not fixed to the lens frame. The position of the frame is not restricted.

  FIG. 10 is a flowchart showing an outline of an operation at the time of photographing of a portable terminal provided with an imaging device having a lens driving device according to the third and fourth embodiments. The flow shown in the figure shows the operation when the mobile terminal is set to the camera mode.

  In the flow shown in the figure, first, a button corresponding to the release button of the portable terminal is operated and waits for being turned on (step S201).

  When a button corresponding to the release button of the portable terminal is turned on (step S201; Yes), the image pickup device is driven to capture an image (step S202). That is, the imaging lens group is moved to the imaging element side by the coil spring 55 (see FIGS. 8 and 9), that is, the lens frame 23 is in contact with the abutting portion 21 t formed on the outer frame member 21. Become. In this state, the image is captured.

  Next, the coil is energized so that the imaging lens group moves toward the subject (step S203). Thereby, the imaging lens group is moved to the subject side against the urging force of the coil spring 55, that is, the lens frame 23 is separated from the abutting portion 21 t and the abutting portion 22 t formed on the lid member 22. It will be in the state contact | abutted. In this state, the image pickup device is driven to capture an image (step S204).

  Thereafter, the image captured in step S202 and the image captured in step S204 are evaluated and compared (step S205). In this evaluation and comparison, for example, each image is subjected to Fourier transform to detect the frequency, and the image having the higher frequency is regarded as an image with higher sharpness, that is, an image in focus. Note that the present invention is not limited to this, and evaluation and comparison based on contrast or the like may be performed.

  Next, the imaging lens group is set so as to be a position where an image with higher sharpness is obtained (step S206). That is, if the image sharpness of the image obtained in step S202 when the image pickup lens group is located on the image sensor side is high, no power is supplied, and the image sharpness obtained in step S204 when the image pickup lens group is located on the subject side. Is higher, the coil is energized as in step S203. As a result, the imaging lens group is set at a focused position.

  Thereafter, actual shooting is performed, an image is recorded (step S207), and shooting of one frame is completed.

  The above is the outline of the operation at the time of photographing of the portable terminal provided with the imaging device having the lens driving device according to the third and fourth embodiments.

  8 and 9 and the flowchart of the operation outline shown in FIG. 10 are described in the case where the imaging lens group is urged toward the image sensor in the optical axis direction by the urging member. However, the imaging lens group may be biased toward the subject side in the optical axis direction.

  If the imaging lens group is biased toward the subject in the optical axis direction, the coil may be energized so as to move the imaging lens group to the imaging element side in step S203 in the flowchart shown in FIG. Furthermore, if the image sharpness is high when the image pickup lens group is located on the subject side in step S206, no power is supplied. If the image sharpness is high when the image pickup lens group is located on the image pickup device side, the same as step S203. The position of the imaging lens group may be set by energizing the coil.

1 is an external view of a mobile phone that is an example of a mobile terminal that incorporates an imaging device including a lens driving device of the present invention. It is a perspective view which shows the outer surface of the imaging device which concerns on this Embodiment. It is sectional drawing of the imaging device which concerns on 1st Embodiment. It is an enlarged view which shows the state between the coil and magnet of the lens drive device shown in FIG. It is sectional drawing of the imaging device which concerns on 2nd Embodiment. It is an enlarged view which shows the state between the coil of the lens drive device shown in FIG. 5, and a magnet, and a coil and a yoke. It is a flowchart which shows the operation | movement outline at the time of imaging | photography of the portable terminal provided with the imaging device which has the lens drive device which concerns on 1st and 2nd embodiment. It is sectional drawing of the imaging device which concerns on 3rd Embodiment. It is sectional drawing of the imaging device which concerns on 4th Embodiment. It is a flowchart which shows the operation | movement outline at the time of imaging | photography of the portable terminal provided with the imaging device which has the lens drive device which concerns on 3rd and 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Imaging lens group 21 Outer frame member 22 Lid member 23 Mirror frame 31 Yoke 32 Magnet 33 Coil 51 Imaging element 52 Substrate F Infrared light cut filter R Viscous fluid S Imaging device T Mobile phone

Claims (7)

A lens frame that holds the imaging lens group; a coil that is formed integrally with the lens frame; a magnet that is disposed to face the coil; and a yoke that holds the magnet. A viscous fluid is interposed in the gap between the magnets, and the lens drive device moves the lens frame in the optical axis direction of the imaging lens group by electromagnetic force generated by supplying power to the coil,
When the lens driving device is viewed in a cross section including the optical axis of the imaging lens group, it is arranged in the order of a lens frame, a coil, a magnet, and a yoke from the optical axis toward the outside.
The gap t (mm) between the coil and the magnet is
0.01 ≦ t ≦ 0.15
The lens driving device is characterized in that the lens frame is held in the direction perpendicular to the optical axis by the viscous fluid. A lens frame that holds the imaging lens group, a coil that is formed integrally with the lens frame, a magnet that is arranged to face the coil, and a magnet that is formed so as to sandwich the coil and that holds the magnet A viscous fluid is interposed in the gap between the coil and the magnet and in the gap between the coil and the yoke, and the coil and the lens frame are moved by the electromagnetic force generated by supplying power to the coil. A lens driving device that moves in the optical axis direction of the imaging lens group,
The gap between the coil and the magnet, and the gap t (mm) between the coil and the yoke,
0.01 ≦ t ≦ 0.15
The lens driving device is characterized in that the lens frame is held in the direction perpendicular to the optical axis by the viscous fluid. A lens frame that holds the imaging lens group, an urging member that urges the lens frame in the optical axis direction, a coil that is integrally formed with the lens frame, and a magnet that is disposed to face the coil And a yoke for holding the magnet, and a viscous fluid is interposed in the gap between the coil and the magnet, and the lens frame is attached to the imaging lens group by electromagnetic force generated by supplying power to the coil. A lens driving device that moves in the optical axis direction,
When the lens driving device is viewed in a cross section including the optical axis of the imaging lens group, it is arranged in the order of a lens frame, a coil, a magnet, and a yoke from the optical axis toward the outside.
The gap t (mm) between the coil and the magnet is
0.01 ≦ t ≦ 0.15
The lens driving device is characterized in that the lens frame is held in the direction perpendicular to the optical axis by the viscous fluid. A lens frame that holds the imaging lens group, an urging member that urges the lens frame in the optical axis direction, a coil that is integrally formed with the lens frame, and a magnet that is disposed to face the coil And a yoke that holds the magnet and sandwiches the coil, and a viscous fluid is interposed in the gap between the coil and the magnet and in the gap between the coil and the yoke. A lens driving device that moves the coil and the lens frame in the optical axis direction of the imaging lens group by electromagnetic force generated by feeding power,
The gap between the coil and the magnet, and the gap t (mm) between the coil and the yoke,
0.01 ≦ t ≦ 0.15
The lens driving device is characterized in that the lens frame is held in the direction perpendicular to the optical axis by the viscous fluid. The lens driving device according to claim 1, wherein the viscous fluid is a magnetic fluid. An imaging apparatus comprising: an imaging element disposed behind the imaging lens group; and the lens driving device according to claim 1. A portable terminal comprising the imaging device according to claim 6.

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