JP4101664B2 - Solid-state imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solid-state image pickup device that picks up an image using an image pickup element, and more particularly to a solid-state image pickup device that can perform macro photography.
[0002]
[Prior art]
Conventionally, a fixed focal length camera using an optical lens with a deep focal depth has been widely used, and so-called macro photography that uses this fixed focal length camera to photograph close to the subject within a few tens of centimeters. If it can be done easily, it is highly useful. However, since the focal position of the lens is different between the case of performing macro photography and the case of performing normal photography of photographing a subject separated by several meters or more, means for changing the focal position is necessary.
[0003]
By the way, as means for changing the focal position of the lens, conventionally, a means for moving the lens holder in the optical axis direction manually or electrically using a screw mechanism has been widely used. Since such a mechanism has a complicated mechanism, consumes a large amount of power, and is noisy, a simple means for adjusting the lens position using an electromagnet has been proposed as an alternative means (see, for example, Patent Document 1). ). The means disclosed in Patent Document 1 is shown in FIG.
[0004]
That is, the lens driving device includes a ring-shaped lens frame 1 having a U-shaped cross section, and a yoke 2 that engages with a concave groove of the U-shaped cross section. The lens frame includes an electromagnet. 11 is arranged, and a permanent magnet 12 is fixed to the yoke 2 so as to face the electromagnet. The lens frame 1 can be propelled in the optical axis direction (horizontal direction in the figure) by passing a current through the electromagnet 11.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-34562 (page 2-3, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, when normal shooting and macro shooting can be performed using the above means, the electromagnet 11 is used to move and hold the lens frame 1 to a predetermined focal position or the like. 1 cannot be accurately stopped at the macro imaging position and the normal imaging position, and power to the electromagnet 11 is required.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a solid-state imaging device having a simple structure that can accurately set a focal position between a macro imaging position and a normal imaging position without requiring power.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, a first feature of the solid-state imaging device according to the present invention includes a substrate on which an imaging element is mounted and a lens unit that holds a lens that forms a subject image on the imaging element. The unit includes a holder fixed to the substrate so as to surround the imaging device, a lens holder that holds the lens and is movable in the optical axis direction, and a first provided in the lens holder. The second permanent magnet provided on the holder, and driving means for moving the lens holder. The first permanent magnet and the second permanent magnet are arranged to face each other in the optical axis direction, at least one of them has a different magnetic pole in a direction orthogonal to the optical axis direction, and the lens The holder or the holder is movably engaged in a direction orthogonal to the optical axis direction, and the driving means moves either the first permanent magnet or the second permanent magnet in a direction orthogonal to the optical axis direction. There is to move.
[0009]
By configuring the invention in this way, the following effects can be obtained. First, by changing the relative position of the first permanent magnet and the second permanent magnet and utilizing the change in magnetic force exerted by each other, the lens holder can be moved to the first and second without requiring any power. It can be driven and held in the second position. Second, for example, the first position is set to the normal imaging position, the second position is set to the macro imaging position, and the lens holder that holds the lens is driven to the first position and the second position. Thus, the lens holder can be accurately moved and held at two different imaging positions. Therefore, it is possible to focus accurately and easily at these two different imaging positions. Third, since the basic configuration is only the first permanent magnet provided in the lens holder and the second permanent magnet provided in the holder that engages the lens holder movably in the optical axis direction, The structure can be made simple and small.
[0010]
Second feature of the solid-state imaging device according to the present invention, drive motion means as described above, wherein 1 is to be moved in a direction perpendicular to said second permanent magnet in the optical axis direction.
[0011]
That is, in the above invention, the first permanent magnet and the second permanent magnet are arranged to face each other in the optical axis direction. For example, both the permanent magnets are arranged in the direction perpendicular to the optical axis direction and the N pole and the S pole. By magnetizing the magnetic pole with the pole and moving the second permanent magnet in a direction orthogonal to the optical axis direction, the N pole and S of the first permanent magnet and the second permanent magnet facing the first permanent magnet It is characterized by changing the relative positions of the poles to change the magnetic force exerted by them along the optical axis direction. If the invention is configured in this way, both permanent magnets exert a magnetic force on each other along the optical axis direction, so that the magnetic force for driving the lens holder in the optical axis direction can be used efficiently, and the structure Can be made simpler and smaller.
[0012]
A third feature of the solid-state imaging device according to the present invention is that the driving means described in any one of the features 1 and 2 has a ring shape centered on the optical axis of the lens, and is freely engaged with the holder. It is in alignment. A fourth feature of the solid-state imaging device according to the present invention is that the first permanent magnet described in any one of the features 1 to 3 and the second permanent magnet are both optical axes of the lens. And having different magnetic poles along the circumferential direction.
[0013]
That is, the driving means in the direction of the optical axis of the lens holder according to the present invention is characterized in that it has a ring shape centered on the optical axis of the lens and is rotatably engaged with the holder. Therefore, if the drive means is rotated around the optical axis, for example, the second permanent magnet provided on the holder and the first permanent magnet provided on the lens holder in the rotational direction about the optical axis. The relative position changes, and the magnetic force exerted by each other can be easily changed. Further, if both the first permanent magnet and the second permanent magnet are formed in a ring shape centered on the optical axis, the balance between the weight and the magnetic force of the permanent magnet is improved, and the drive means is as described above. Combined with the ring shape, the structure can be made simpler and smaller.
[0014]
A fifth feature of the solid-state imaging device according to the present invention is that the lens holder described in any one of the features 1 to 4 is movably engaged with the holder in the optical axis direction. By directly engaging the lens holder with the holder in this way, other members for movably engaging the lens holder are not required, and the structure can be made simpler and more compact.
[0015]
A sixth feature of the solid-state imaging device according to the present invention is that the first position described in any one of the features 1 to 5 is a normal imaging position for capturing a subject image located in the normal imaging region, The second position is a macro imaging position for imaging a subject image located in the short-distance imaging area.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The configuration of the solid-state imaging device according to the present invention will be described with reference to FIGS. The solid-state imaging device includes a substrate 1 on which an imaging device 11 made of a CCD is mounted, and a lens unit 2 that holds a lens 21 that forms a subject image on the imaging device.
The lens unit 2 includes a holder 22 fixed to the substrate 1, a lens holder 23 that is movably engaged with the holder in the optical axis direction of the lens 21, and a first permanent magnet 24 provided on the lens holder. And a second permanent magnet 25 provided in the holder, and a driving means 26 for moving the lens holder.
[0017]
The holder 22 has a cylindrical portion 22 a and a horizontal flange portion 22 b provided at the upper end of the cylindrical portion, and the cylindrical portion is fixed to the substrate 1 so as to surround the imaging element 11. A circumferential groove 22c is formed on the upper end surface of the cylindrical portion 22a. On the other hand, the lens holder 23 has a substantially cylindrical shape, and the lens 21 is held by a lens cap 27 at the center thereof. The lower end 23a of the lens holder 23 is inserted into and engaged with the circumferential groove 22c of the holder 22 described above. The circumferential groove 22c is provided with a key 22d made of a protrusion parallel to the optical axis at least at one location on the circumference. The key groove provided on the lower end 23a of the lens holder 23 is provided on this key. 23b is engaged. Therefore, the lens holder 23 is restrained from moving in the circumferential direction by the key 22d, and can move only in the optical axis direction with respect to the holder 22.
[0018]
A male screw 23b is screwed on the outer periphery of the lens holder 23, and a female screw 28a of a ring-shaped magnet holder 28 is screwed into the male screw. A ring-shaped first permanent magnet 24 is attached to the outer periphery of the magnet holder 28. The first permanent magnet 24 is magnetized so that the four divided regions are alternately N and S poles along the circumferential direction. As shown in FIG. 5, the first permanent magnet 24 is magnetized by inserting a magnetic body 90 inside the ring member and placing magnetizing devices 9 such as electromagnets at four locations outside the ring member. Do it.
[0019]
On the upper surface of the horizontal flange portion 22b of the holder 22, a ring-shaped spacer 26 centering on the optical axis is rotatably abutted, and this spacer constitutes the driving means 26 described above. On the upper surface of the spacer 26, a second permanent magnet 25 having the same shape and magnetic pole as the first permanent magnet 24 is mounted at a position facing the first permanent magnet in the optical axis direction. A drive lever 26a protrudes from at least one place on the circumference. A cylindrical portion 22e is provided on the outer peripheral portion of the horizontal flange portion 22b of the holder 22, and the height of the cylindrical portion in the optical axis direction is slightly smaller than the thickness of the spacer 26 so as not to hinder the rotation of the spacer. Is getting bigger.
[0020]
A hollow cylindrical positioning holder 29 is bonded to the upper end surface of the cylindrical portion 22 e of the holder 22. The lower end surface 29a of the positioning holder 29 is in contact with the upper end surface of the cylindrical portion 22e so as to cover the upper surface of the outer peripheral portion of the spacer 26, and restrains the movement of the spacer in the optical axis direction. Further, a lid portion 29b orthogonal to the optical axis is formed on the upper portion of the positioning holder 29. The lower surface of the lid portion is spaced from the upper end surface of the magnet holder 28 screwed into the lens holder 23 with a predetermined distance in the optical axis direction. Are facing each other. The lid 29b of the positioning holder 29 is provided with a groove 29c into which a drive lever 26a protruding from the spacer 26 can be inserted and which can be rotated by 90 degrees about the optical axis.
[0021]
Next, the operation of the above-described solid-state imaging device will be described. 1 and 2 show a case where the lens holder 23 is set to a normal imaging position for capturing a subject image located in the normal imaging region. That is, the drive lever 26a protruding from the spacer 26 is in contact with the groove 29c provided in the lid portion 29b of the positioning holder 29 at the end portion 29e at the 12 o'clock position in FIG. At this position, the first permanent magnet 24 and the second permanent magnet 25 are assembled such that the magnetic poles divided into four in the circumferential direction are opposed to the S pole and the N pole, respectively. Accordingly, as shown in FIG. 2, the first permanent magnet 24 and the second permanent magnet 25 are attracted and attracted by the mutual magnetic force, and the lens holder 23 is attached to the first permanent magnet 24. Is held at a position where it is attracted to the second permanent magnet 25, and the normal imaging position is precisely set at this position in the optical axis direction.
[0022]
On the other hand, FIGS. 3 and 4 show a case where the lens holder 23 is set to a macro imaging position for imaging a subject image located in the short-distance imaging area. That is, the drive lever 26a projecting from the spacer 26 is rotated 90 degrees counterclockwise in FIG. 3 from the position described above, and the groove 29c provided in the lid portion 29b of the positioning holder 29 and the 9 o'clock position in FIG. When contact is made at a certain end portion 29f, the second permanent magnet 25 mounted on the spacer also rotates counterclockwise by 90 degrees, and the first permanent magnet 24 and the magnetic pole divided into four in the circumferential direction are The N and N poles, and the S and S poles face each other. Therefore, as shown in FIG. 4, the first permanent magnet 24 and the second permanent magnet 25 repel each other by the magnetic force, and move the first permanent magnet upward. Accordingly, the lens holder 23 to which the first permanent magnet 24 is attached is held by moving the upper end surface of the magnet holder 28 attached thereto to a position where it abuts the lower surface of the lid portion 29b of the positioning holder 29. The macro imaging position is set precisely at the directional position.
[0023]
As described above, the drive lever 26a protruding from the spacer 26 is rotated 90 degrees counterclockwise or clockwise, and brought into contact with the end portions 29f and 29e of the groove 29c of the lid portion 29b of the positioning holder 29, respectively. As a result, the lens holder 23 can be easily and precisely set to the normal imaging position and the macro imaging position. Further, the focus adjustment can be easily performed by rotating the magnet holder 28 screwed into the lens holder 23 at the time of assembly.
[0024]
In addition, since the relative positions of the first permanent magnet 24 and the second permanent magnet 25 are changed and the first permanent magnet 24 is driven in the optical axis direction by the attractive force and the repulsive force exerted by each other, a simple configuration is achieved. Thus, the lens holder 23 can be driven in the optical axis direction without consuming any power, and the lens holder can be reliably held at two positions, the normal imaging position and the macro imaging position.
[0025]
Further, the first permanent magnet 24 and the second permanent magnet 25 are arranged opposite to each other in the optical axis direction, and the second permanent magnet is rotated to change the magnetic force exerted by both of them along the optical axis direction. Therefore, the magnetic force for driving the lens holder 23 in the optical axis direction can be used efficiently.
[0026]
Further, since both the first permanent magnet 24 and the second permanent magnet 25 are ring-shaped around the optical axis, the weight balance is good and the lens holder 23 is stabilized without tilting the optical axis of the lens 21. Can be driven.
[0027]
Further, since the spacer 26 for driving the second permanent magnet 25 has a ring shape and is rotatably engaged with the holder 22, the second permanent magnet can be easily rotated. Furthermore, since the lever 26a is formed in this spacer, the second permanent magnet can be rotated more easily.
[0028]
Since the holder 22 is formed with a circumferential groove 22c that engages with the lower end portion 23a of the lens holder 23 in the optical axis direction, a simple mechanism for guiding the lens holder 23 is not used. The structure can guide the movement of the lens holder in the optical axis direction. Further, the engagement between the circumferential groove 22c and the lens holder 23 can prevent unnecessary light from entering from the outside.
[0029]
Further, since the key 22d is formed in the circumferential groove 22c, and the key groove 23b formed in the lower end portion 23a of the lens holder 23 is engaged with this key, the movement of the lens holder 23 in the circumferential direction is restrained. The first permanent magnet 24 can be prevented from rotating with the rotation of the second permanent magnet 25.
[0030]
Further, since the magnet holder 28 is screwed to the lens holder 22 so as to be movable along the optical axis direction of the lens 21, the first permanent magnet for the lens holder is rotated by rotating the lens holder or the magnet holder. 24 and the position of the magnet holder in the optical axis direction, that is, the focus of the solid-state imaging device can be easily adjusted.
[0031]
As described above, the first permanent magnet 24 and the second permanent magnet 25 are not limited to the case where the magnetic poles are divided into four parts in the circumferential direction and different magnetic poles are magnetized in each region. Different magnetic poles may be magnetized. Here, the greater the number of magnetic poles in the circumferential direction, the smaller the rotation angle of the permanent magnet, and the lens holder can be driven more easily. Further, both or both of the first permanent magnet 24 and the second permanent magnet 25 are made into bar magnets, and, for example, 4 along the circumferential direction so as to extend in the radial direction around the optical axis. It is also possible to arrange them so that one magnetic pole of the bar magnet faces one magnetic pole of the other permanent magnet in the optical axis direction.
[0032]
Further, in the case where both the first permanent magnet 24 and the second permanent magnet 25 or one of them is a bar magnet, the bar magnet is moved linearly, for example, the N extreme of this bar magnet is changed to the other. It is also possible to constitute the permanent magnet so as to alternately face the N pole and the S pole in the optical axis direction.
[0033]
In this embodiment, the positioning holder 29 is bonded to the upper end surface of the cylindrical portion 22e. However, a male screw or a female screw is threaded on the outer periphery of the cylindrical portion 22e, and a screw portion that can be screwed to the screw is provided on the positioning holder. Accordingly, the positioning holder and the cylindrical portion may be screwed together so as to be movable along the optical axis direction. In this way, the position of the lid portion 29b in the optical axis direction, that is, the macro imaging position can be easily adjusted. Further, the macro imaging position can be easily adjusted even if the lower end surface 29a and the lid portion 29b of the positioning holder 29 are configured as separate members and are screwed together so as to be movable along the optical axis direction.
[0034]
Further, in the present embodiment, the relative position of the first and second permanent magnets 24 and 25 is changed by rotating the lever 26a by 90 °, but the rotation angle of the lever is not limited to this. For example, when the number of different magnetic poles in the circumferential direction of the first and second permanent magnets is small, the rotation angle of the lever becomes large, and the number of different magnetic poles in the circumferential direction of the first and second permanent magnets is large. The lever rotation angle may be small.
[0035]
In the present embodiment, the relative positions of the first and second permanent magnets 24 and 25 are changed by rotating the second permanent magnet 25, but the first permanent magnet 25 is rotated to rotate the first permanent magnet 25. The relative position of the second permanent magnet may be changed.
[0036]
In this embodiment, the key 22d is formed in the circumferential groove 22c to restrict the movement of the lens holder 23 in the circumferential direction. However, the magnet holder 28 or the lens holder circle is placed on the lid 29b of the positioning holder 29 or the like. You may provide the restraint part which restrains the movement of the circumferential direction.
[0037]
In the present embodiment, the first and second positions are the normal imaging position and the macro imaging position, respectively, but the first and second positions are not limited to this.
[0038]
The present invention is not limited to the case where the CCD element as described above is used as the image pickup element 11, but can be easily applied to a case where, for example, a CMOS element or a normal film is used.
[0039]
【The invention's effect】
First, by changing the relative position of the first permanent magnet and the second permanent magnet and utilizing the change in magnetic force exerted by each other, the lens holder can be moved to the first and second without requiring any power. It can be driven to the second position. Second, for example, the first position is set to the normal imaging position, the second position is set to the macro imaging position, and the lens holder that holds the lens is driven to the first position and the second position. Thus, the lens holder can be accurately moved and held at two different imaging positions. Therefore, it is possible to easily and precisely focus at these two different imaging positions.
[0040]
Third, the basic configuration is only the first permanent magnet provided in the lens holder and the second permanent magnet provided in the holder that supports the lens holder so as to be movable in the optical axis direction. Can be made simple and small. Fourth, the first permanent magnet and the second permanent magnet opposed to the first permanent magnet in a ring shape centering on the optical axis of the lens, respectively, and different magnetic poles in the circumferential direction The weight of the permanent magnet is such that the lens holder is moved in the direction of the optical axis by utilizing the mutual attraction and repulsion of the mutual magnetic force. And the balance of magnetic force can be improved, and the structure can be made simpler and smaller. Fifth, a rotation lever is attached to the spacer that rotationally drives the second permanent magnet, and the rotation lever is restrained from further rotation in the first position and the second position. A sense of certainty is obtained in the switching operation to the position, and erroneous operation can be prevented.
[Brief description of the drawings]
FIG. 1 is a top view of a solid-state imaging device when normal imaging is performed.
FIG. 2 is a cross-sectional view of a solid-state imaging device when normal imaging is performed.
FIG. 3 is a top view of the solid-state imaging device when performing macro imaging.
FIG. 4 is a cross-sectional view of a solid-state imaging device when performing macro imaging.
FIG. 5 is an explanatory diagram of a method for magnetizing a ring-shaped permanent magnet.
FIG. 6 is a cross-sectional view of a lens driving device according to a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Board | substrate 11 Image pick-up element 2 Lens unit 21 Lens 22 Holder 23 Lens holder 24 1st permanent magnet 25 2nd permanent magnet 26 Spacer (drive means)

Claims (6)

A substrate on which an image sensor is mounted, and a lens unit that holds a lens that forms a subject image on the image sensor;
The lens unit includes a holder fixed to the substrate so as to surround the imaging device, a lens holder that holds the lens and is movable in the optical axis direction, and a first provided in the lens holder. A permanent magnet, a second permanent magnet provided in the holder, and a driving means for moving the lens holder,
The first permanent magnet and the second permanent magnet are arranged to face each other in the optical axis direction, and at least one of the first permanent magnet and the second permanent magnet is
It has different magnetic poles in a direction perpendicular to the optical axis direction, and is movably engaged with the lens holder or the holder in a direction perpendicular to the optical axis direction,
The solid-state imaging device , wherein the driving unit moves either the first permanent magnet or the second permanent magnet in a direction orthogonal to the optical axis direction . The solid-state imaging device according to claim 1, wherein the driving unit moves the second permanent magnet in a direction orthogonal to the optical axis direction . 3. The solid-state imaging device according to claim 1, wherein the driving unit has a ring shape centered on the optical axis of the lens and is rotatably engaged with the holder . In one of claim 1 to 3, the a first permanent magnet and the second permanent magnet each have a ring shape around the optical axis of the lens, in the circumferential direction A solid-state imaging device having different magnetic poles along the same . 5. The solid-state imaging device according to claim 1, wherein the lens holder is movably engaged with the holder in an optical axis direction . 6. The method according to claim 1, wherein the first position is a normal imaging position for capturing a subject image located in the normal imaging area, and the second position is a position in the short-distance imaging area. A solid-state imaging device, which is a macro imaging position for imaging a subject image to be captured .

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