JP2004280039A - Solid state imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely switch, at low power, the position of a lens to two focal positions of the macro-imaging and the normal imaging. <P>SOLUTION: A lens holder 12 is movably attached to a holder 11 provided to a substrate 6 on which a CCD61 (charge coupled device) is loaded, and a permanent magnet 2 magnetized so that the region divided into four with respect to the circumferential direction alternately becomes the N and S poles is wound around the outer circumference of the lens holder. The first and the second magnetic bodies 4 and 5 facing at an interval in a prescribed direction of the optical axis are disposed in an axially symmetrical pair of regions among the regions in which the permanent magnet 2 is divided into 4, each is magnetized into N or S pole by an electromagnet 3. By switching the direction of the current of the electromagnet 3, the permanent magnet 2 is instantaneously moved so as to abut against the first or the second magnet 4 or 5. Even when the current of the electromagnet 3 is turned off, the attractive holding to the first or the second magnet 4 or 5 can be maintained by the magnetic force of the permanent magnet 2 itself. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solid-state imaging device that performs imaging using an imaging element, and more particularly to a solid-state imaging device that can perform macro imaging.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a so-called digital camera that forms an image of a subject on an image sensor of a CCD (charge coupled device) using an optical lens has been widely used. Various types of digital cameras have been proposed, but if digital cameras can easily perform so-called macro imaging, which captures images in close proximity to a subject within several tens of centimeters, it is highly useful. In order to perform macro imaging, it is necessary to change the focal position of a lens when capturing an image of a subject that is several meters or more away.
[0003]
By the way, as a means for changing the focal position of a lens, a means for moving a 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 has high noise, a means for adjusting the lens position using an electromagnet has been proposed as an alternative to the means (for example, see 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 engaging with the concave groove having the U-shaped cross section. A coil (electromagnet) 11 is arranged, and a (permanent) magnet 12 is fixed to the yoke 2 so as to face the coil. By passing a current through the coil 11, the lens frame 1 can be moved in the optical axis direction.
[0005]
[Patent Document 1]
JP-A-5-34562 (page 2-3, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, when the lens position is switched between the normal imaging position and the macro imaging position using the above-described means, there are the following problems. That is, it is described that the lens frame 1 is moved only by passing a current through the coil 11, and it is not clear how to accurately stop the lens frame at a predetermined zoom position or focus position. Further, in order to accurately hold the lens frame 1 at a predetermined zoom position or focus position, it is necessary to keep a current flowing through the coil 11 and maintain a magnetic force. Therefore, with the above-described means, the lens frame 1 cannot be accurately stopped at the macro imaging position or the normal imaging position, and in order to hold the lens frame 1 at these positions, it is necessary to supply a current to the coil 11, Consumption increases.
[0007]
Therefore, an object of the present invention is to provide a solid-state imaging device with a simple structure, which can switch a lens position between two different focal positions with low power and high accuracy.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, a first feature of a solid-state imaging device according to the present invention is a lens unit that holds a substrate on which an imaging element is mounted and a lens that is mounted on the substrate and forms a subject image on the imaging element. 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 lens holder. And an electromagnetic drive means for driving to a first position and a second position which is moved from the first position by a predetermined distance in the optical axis direction.
[0009]
By configuring the invention in this manner, the following operation and effect can be obtained. That is, first, since the lens holder is merely moved in the optical axis direction with respect to the holder mounted on the substrate by the electromagnetic driving means, the configuration is extremely simple. Secondly, by driving the lens holder to the first position and the second position separated from the first position by a predetermined optical axis direction by the electromagnetic driving means, the lens position can be accurately and reliably set. It is possible to switch between two different focal positions, and control of the electromagnetic driving means is also facilitated.
[0010]
According to a second feature of the solid-state imaging device according to the present invention, the electromagnetic driving means described in the feature 1 includes an electromagnet, a first magnetic body magnetized by energizing the electromagnet, and a first magnetic body. A second magnetic body opposed to the optical axis in the optical axis direction, and a permanent magnet disposed on the lens holder between the first magnetic body and the second magnetic body. The permanent magnet is driven to a first position where the permanent magnet is attracted to the first magnetic body and a second position where the permanent magnet is attracted to the second magnetic body in accordance with energization of the electromagnet.
[0011]
That is, the configuration can be simplified because the first magnetic body has two functions of the drive source for driving the permanent magnet and the magnetic body for holding the permanent magnet at the first position. Further, since the permanent magnet is attracted and held by the first magnetic body and the second magnetic body by its own magnetic force, electric power for holding the permanent magnet at the first position and the second position becomes unnecessary, and the Power can be saved.
[0012]
A third feature of the solid-state imaging device according to the present invention is that the permanent magnet described in the feature 2 has a magnetic pole portion that is different in a direction orthogonal to the optical axis direction, and the second magnetic body is activated by energizing the electromagnet. That is, it is magnetized to a magnetic pole different from that of the first magnetic body. A fourth feature of the solid-state imaging device according to the present invention is that the electromagnet is provided on the holder along the outer periphery of the lens holder.
[0013]
By magnetizing the first magnetic body to a magnetic pole different from that of the second magnetic body and facing each other with the permanent magnet interposed therebetween, one of these magnetic bodies attracts the permanent magnet, and the other attracts the permanent magnet. Is repelled, the magnetic force for driving the permanent magnet is increased, and the permanent magnet can be driven more reliably. In addition, by providing the electromagnet on the holder along the outer periphery of the lens holder, the size of the solid-state imaging device can be reduced as compared with a case where the electromagnet is provided at a location different from the lens holder.
[0014]
A fifth feature of the solid-state imaging device according to the present invention is that, in the permanent magnet described in any of the above features 3 or 4, only one of the magnetic poles is provided between the first magnetic body and the second magnetic body. It is located.
[0015]
That is, when both the magnetic poles of the permanent magnet are sandwiched between the first magnetic body and the second magnetic body, one of the two magnetic poles opposed to each other is attracted, but the other magnetic pole is repelled. As a result, the suction force is reduced. Therefore, by configuring the first magnetic body and the second magnetic body to sandwich only one of the different magnetic pole portions of the permanent magnet, the influence of the magnetic force of the other magnetic pole portion can be eliminated. Can be reliably sucked or repelled to move.
[0016]
According to a sixth feature of the solid-state imaging device according to the present invention, the permanent magnet described in the second feature has a magnetic pole portion different in a direction orthogonal to the optical axis direction, and the first magnetic body is orthogonal to the optical axis direction. And a pair of magnetic bodies that are magnetized to different magnetic poles by energizing the electromagnet. One of the magnetic members is arranged in the optical axis direction with respect to one magnetic pole portion of the permanent magnet, and the other is arranged in the optical axis direction with respect to the other magnetic pole portion of the permanent magnet. Have been. A seventh feature of the solid-state imaging device according to the present invention is that the first magnetic body described in the above feature 6 has an arc shape. An eighth feature of the solid-state imaging device according to the present invention is that the holder described in any one of the above features 6 and 7 has a positioning portion for positioning the first magnetic body.
[0017]
By causing the pair of first magnetic materials having different magnetic poles to face the different magnetic pole portions of the permanent magnet in this manner, simultaneously applying an attractive force or a repulsive force to both of the different magnetic pole portions of the permanent magnet. Therefore, the driving force of the permanent magnet is increased, and the permanent magnet can be driven more reliably. Further, if a pair of first magnetic bodies having different magnetic poles are formed in an arc shape, the pair of first magnetic bodies can be disposed on both sides of the lens holder, so that the lens holder can be stably provided without tilting. Can be driven. Further, by positioning by the positioning portion provided on the holder, it is possible to prevent the fixed position of the first magnetic body from shifting.
[0018]
A ninth feature of the solid-state imaging device according to the present invention is that the second magnetic body described in any one of the above features 6 to 7 is engaged with the holder so that the position can be adjusted in the optical axis direction. is there.
[0019]
That is, the set first or second focal position may be slightly shifted depending on the manufacturing or assembly dimensional tolerance of the component. Therefore, if the focus position can be accurately adjusted and the initial setting can be performed for each solid-state imaging device, clear imaging can be performed. Therefore, by providing such a focal position initial setting means, it is not necessary to make the manufacturing or assembly dimensional tolerance of the component parts more strict than necessary.
[0020]
A tenth feature of the solid-state imaging device according to the present invention is that at least one of the first magnetic body and the second magnetic body described in any one of the above-described features 2 to 9 is a portion where a permanent magnet is attracted. Is provided with a projection.
[0021]
In the solid-state imaging device according to the present invention, when the permanent magnet is attracted to the first or second magnetic body, the magnetic attraction of the permanent magnet is strong, and the next time the magnet is attracted in the opposite direction, the permanent magnet is attracted to the first or second magnetic body. In some cases, it is difficult to separate from the second magnetic body. Therefore, a minute projection is provided at a position where the permanent magnets of the first and second magnetic bodies are attracted, and the permanent magnet is attracted to the first or second magnetic body via the minute projections. The permanent magnet is easily separated from the first and second magnetic bodies.
[0022]
An eleventh feature of the solid-state imaging device according to the present invention is that the permanent magnet described in any one of the above features 2 to 10 has a ring shape centered on the optical axis of the lens and extends along a circumferential direction thereof. Have different magnetic pole portions.
[0023]
By making the permanent magnet ring-shaped around the optical axis of the lens, the weight balance of the permanent magnet is excellent and the magnetic force can be easily balanced, so that the lens holder is stable without tilting. And can be driven.
[0024]
According to a twelfth feature of the solid-state imaging device according to the present invention, the permanent magnet described in the feature 11 has a magnetic pole portion different in a radial direction, and a ring member made of a magnetic material is provided inside the permanent magnet. It is to be.
[0025]
That is, when a ring member made of a magnetic material is attached to the inside of a ring-shaped permanent magnet having different magnetic pole portions in the circumferential and radial directions, a closed magnetic path is formed inside the permanent magnet, and leakage of magnetic flux can be prevented.
[0026]
A thirteenth feature of the solid-state imaging device according to the present invention is that the lens holder according to any one of the above features 1 to 12 is movably engaged with the holder in the optical axis direction. A fourteenth feature of the solid-state imaging device according to the present invention resides in that at least one of the lens holder described in the above feature 13 and the holder is provided with a guide groove for guiding the movement of the lens holder.
[0027]
As described above, by engaging the lens holder movably with the holder in the optical axis direction, the lens holder can be movably arranged with a very simple configuration. Also, by inserting one of the lens holder and the holder into the other guide groove and moving it, it is possible to reliably prevent light from entering from the outside.
[0028]
A fifteenth feature of the solid-state imaging device according to the present invention is that the first position described in any one of the above features 1 to 14 is a normal imaging position for imaging a subject image located in a normal imaging region. The second position is a macro image pickup position for picking up a subject image located in the short-range image pickup area.
[0029]
A sixteenth feature of the solid-state imaging device according to the present invention is that a holding force of the lens holder at the normal imaging position is larger than a holding force of the lens holder at the macro imaging position.
[0030]
Therefore, the holding power of the lens holder at the normal imaging position is larger than the holding power of the lens holder at the macro imaging position. It is possible to prevent the position from being accidentally shifted from
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
The configuration of the solid-state imaging device according to the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the solid-state imaging device includes a substrate 6 on which an imaging device including a CCD 61 is mounted, and a lens unit 1 that is mounted on the substrate and holds a lens 13 that forms a subject image on the CCD. And The lens unit 1 includes a holder 11 fixed to the substrate 6 so as to surround the CCD 61, a lens holder 12 that holds the lens 13 and movably engages the holder in the optical axis direction of the lens, and a lens holder 12. Electromagnetic drive means for driving the holder to a first position and to a second position moved from the first position by a predetermined distance in the optical axis direction.
[0032]
The lens holder 12 has a hollow, substantially cylindrical shape, and has a lens 13 mounted on a center axis thereof by a lens cap 14. The lower cylindrical portion 12a of the lens holder 12 is engaged with a cylindrical guide groove 11a formed on the holder 11, and is movable in the optical axis direction. The first position is a normal imaging position for imaging a subject image located in the normal imaging region, and the second position is a macro imaging position for imaging a subject image located in the short-distance imaging region. is there.
[0033]
The electromagnetic driving means includes an electromagnet 3, a first magnetic body 5 magnetized by energizing the electromagnet, a second magnetic body 4 opposed to the first magnetic body in the optical axis direction, A permanent magnet 2 provided along the outer periphery of the lens holder 12 is provided between the first magnetic body and the second magnetic body. The electromagnet 3 is formed by winding an electric coil 32 around a bobbin 31 formed of a ring member having a U-shaped cross section. As shown in FIG. 4, the first magnetic body 5 and the second magnetic body 4 are formed of ring members having an L-shaped cross section, and surround the lower surface and the inner surface, and the upper surface and the outer surface of the electromagnet 3, respectively. It is arranged as follows.
[0034]
The permanent magnet 2 has a ring shape and is attached to the outer periphery of a magnet holder 15 screwed to the outer periphery of the lens holder 12. Further, the permanent magnet 2 is magnetized such that regions divided into four along the circumferential direction are alternately arranged with N magnetic poles and S magnetic poles. Therefore, a pair of axially symmetric regions of the N magnetic pole and the S magnetic pole are respectively formed. As shown in FIG. 7, the permanent magnet 2 has a magnetic body 91 inserted inside a ring member 90 and four electromagnets 92 arranged outside the ring member 90 so that the N magnetic pole and the S magnetic pole are alternately formed. Magnetize side by side. That is, if the ring member 90 is magnetized without inserting the magnetic body 91 inside the ring member 90, different magnetic poles are generated on the outer peripheral side and the inner peripheral side of the ring member 90, respectively. The magnetic body 91 is inserted inside the inside so that the circumferential area of 90 degrees becomes the same magnetic pole.
[0035]
As shown in FIGS. 3 and 4, a pair of N-pole regions 2a of the permanent magnet 2 are provided on the inner circumference of the first magnetic body 5 and the second magnetic body 4 in a predetermined direction in the optical axis direction. A pair of protruding portions 5a, 4a protruding so as to be sandwiched from below and above, respectively, are formed symmetrically with respect to the optical axis, that is, at intervals of 180 degrees. Note that small protrusions (not shown) are formed on the protrusions 5a and 4a at contact portions between the lower surface and the upper surface of the permanent magnet 2.
[0036]
Next, the operation of the above-described solid-state imaging device will be described. That is, when a current is applied to the electric coil 32 in the clockwise direction in FIG. 3, as shown in FIGS. 3 and 4, the protrusion 5a of the first magnetic body 5 becomes the N pole and the protrusion of the second magnetic body 4 The portion 4a is magnetized to the south pole. Therefore, the pair of protrusions 5a, 5a of the first magnetic body 5 and the N-type regions 2a, 2a of the permanent magnet 2 opposed thereto repel each other. On the other hand, the pair of protrusions 4a, 4a of the second magnetic body 4 and the N-type regions 2a, 2a of the permanent magnet 2 facing each other attract each other. Therefore, the permanent magnet 2 is driven upward by the magnetic force of both the repulsive force and the attractive force and is attracted to the lower surface of the protruding portion 4a of the second magnetic body 4, and this position becomes the macro imaging position. In this state, even if the current flowing through the electric coil 32 is stopped, the permanent magnet 2 is attracted and held on the lower surface of the protrusion 4a of the second magnetic body 4 by its own magnetic force. Thus, the lens holder 12 is driven and held at the macro imaging position.
[0037]
On the other hand, as shown in FIGS. 5 and 6, when a current is applied to the electric coil 32 in the counterclockwise direction in FIG. 5, the protrusion 5 a of the first magnetic body 5 becomes the S pole and the second magnetic body 4 The protrusion 4a is magnetized to the N pole. Accordingly, the permanent magnet 2 is driven downward and is attracted to the upper surface of the protruding portion 5a of the first magnetic body 5 by the operation opposite to that described above, and this position becomes the normal imaging position. In this state, even if the current flowing through the electric coil 32 is stopped, the permanent magnet 2 is attracted and held on the upper surface of the protrusion 5a of the first magnetic body 5 by its own magnetic force. Thus, the lens holder 12 is driven and held at the normal imaging position.
[0038]
Therefore, by changing the direction of the current flowing through the electric coil 32 clockwise by a switching means (not shown) such as a changeover switch, the lens holder 12 can be accurately and reliably moved between the macro imaging position and the normal imaging position. Can be driven. Further, once the lens holder 12 is driven between the macro image pickup position and the normal image pickup position, even if the current is cut off, the lens holder 12 is held at each position by the magnetic force of the permanent magnet 2 itself, as described above, so that the cost is greatly reduced. Power can be used.
[0039]
In this embodiment, the holding force of the lens holder 12 at the normal imaging position, that is, the attraction force acting between the permanent magnet 2 and the first magnetic body 5 is the holding force of the lens holder 12 at the macro imaging position. That is, it is larger than the attraction force acting between the permanent magnet 2 and the second magnetic body 4. This can be realized, for example, by making the contact area between the permanent magnet 2 and the protrusion 5a of the first magnetic body 5 larger than the contact area between the permanent magnet 2 and the protrusion 4a of the second magnetic body 4.
[0040]
This prevents the lens holder 12 from being inadvertently displaced from the normal imaging position and not being able to accurately capture the subject image when capturing the subject image at the normal imaging position that is more frequently used than the macro imaging position. it can. When the macro imaging position is used more frequently than the normal imaging position, the holding force of the lens holder 12 at the macro imaging position may be larger than the holding force of the lens holder 12 at the normal imaging position.
[0041]
In addition, the first and second magnetic bodies 4 and 5 are magnetized to different magnetic poles by energizing the electromagnet 3, so that a magnetic force of attraction and repulsion is generated between each magnetic body and the permanent magnet 2. Therefore, the magnetic force acting on the permanent magnet increases, and the permanent magnet 2 can be driven more reliably.
[0042]
Further, since the electromagnet 3 is provided on the holder 11 along the outer periphery of the lens holder 12, the size of the solid-state imaging device can be reduced as compared with the case where the electromagnet 3 is provided separately from the lens holder.
[0043]
Also, N very Since only the region 2a is sandwiched between the protrusions 4a and 5a, N and S very The permanent magnet 2 can be driven more easily than when both regions are sandwiched.
[0044]
Further, since the permanent magnet 2 has a ring shape centering on the optical axis of the lens 3, the weight balance is good, and the lens holder 12 can be driven stably without the optical axis of the lens 13 being inclined.
[0045]
Further, since the holder 11 is formed with the guide groove 11a which engages with the cylindrical portion 12a in the optical axis direction, the lens holder 12 can be formed with a simple configuration without using a special mechanism for guiding the lens holder 12. Can be guided in the optical axis direction. In addition, by the engagement between the guide groove 11a and the cylindrical portion 12a, unnecessary intrusion of light from the outside can be prevented.
[0046]
Further, since the magnet holder 15 is screwed to the lens holder 12 so as to be movable along the optical axis direction of the lens 13, by rotating the lens holder or the magnet holder, the light of the permanent magnet 2 with respect to the lens holder is changed. The position in the axial direction, that is, the focus of the solid-state imaging device can be adjusted.
[0047]
The protrusions 5a and 4a of the first magnetic body 5 and the second magnetic body 4 are provided with the above-described protrusions, so that the attraction force of the permanent magnet 2 does not become excessive, When the magnet is driven in the opposite direction, it can be easily separated from the protrusion.
[0048]
Here, in the present embodiment, the pair of N-pole regions 2a are sandwiched between the protruding portions 5a and 4a at a predetermined interval. However, the pair of S-pole regions of the permanent magnet 2 may be sandwiched. Further, if both the N-pole and S-pole regions are sandwiched, the holding force of the permanent magnet 2 with respect to the first and second magnetic bodies 4 and 5 increases. In this case, in order to drive the permanent magnet 2 smoothly, it is better to make the areas sandwiched by the N and S pole regions uneven.
[0049]
Further, in this embodiment, the permanent magnet 2 having four magnetic poles different in the circumferential direction is used as the permanent magnet, but the number of magnetic poles of the permanent magnet is not limited to this, and may be, for example, six or eight. . Further, permanent magnets having different magnetic poles in regions obtained by dividing the circumferential direction and the radial direction into two may be used as described in a second embodiment described later.
[0050]
Next, another embodiment will be described with reference to FIGS. As shown in FIGS. 8 and 9, the solid-state imaging device includes a substrate 106 on which an imaging element including a CCD 161 is mounted, and a lens unit 101 mounted on the substrate and holding a lens 113 for forming a subject image on the CCD. And The lens unit 101 includes a holder 111 fixed to the substrate 106 so as to surround the CCD 161, a lens holder 112 that holds the lens 113 and movably engages the holder in the optical axis direction of the lens, and a lens holder 112. Electromagnetic drive means for driving the holder to a first position and to a second position moved from the first position by a predetermined distance in the optical axis direction.
[0051]
The lens holder 112 has a hollow, substantially cylindrical shape, and has a lens 113 mounted on a center axis thereof by a lens cap 114. Further, a cylindrical guide groove 112a is formed in the lens holder 112, and a cylindrical portion 111j forming an upper portion of the holder 111 is engaged with the circumferential groove, so that the lens guide 112 is movable in the optical axis direction. . The first position is a normal imaging position for imaging a subject image located in the normal imaging region, and the second position is a macro imaging position for imaging a subject image located in the short-distance imaging region. is there.
[0052]
The electromagnetic driving means includes an electromagnet 103, first magnetic bodies 133 and 134 that are magnetized by energization of the electromagnet, and a second magnetic body 104 that faces the first magnetic body in the optical axis direction. And a permanent magnet 102 provided along the outer periphery of the lens holder 112 between the first magnetic body and the second magnetic body. For ease of explanation, the permanent magnet 102, the electromagnet 103, the first magnetic bodies 133 and 134, and the second magnetic body 104 will be described in this order.
[0053]
The permanent magnet 102 is wound around a magnet holder 115 via a ring member 121 made of a magnetic material wound around the inner periphery thereof. The magnet holder 115 is screwed to the outer periphery of the lens holder 112. Further, the permanent magnet 102 is magnetized so that a region divided into two in the circumferential direction becomes an N pole and an S pole. That is, as shown in FIG. 12, when the ring member is first magnetized in the diametric direction by a magnetizing device 192 such as an electromagnet, different magnetic poles are attached to the outer peripheral side and the inner peripheral side for each of two regions divided in the circumferential direction. Magnetized. Next, when a ring member 121 made of a magnetic material is mounted inside the magnetized permanent magnet 102, a closed magnetic path (not shown) is formed on the inner peripheral side to prevent leakage of magnetic flux inside the permanent magnet 102. it can.
[0054]
On the other hand, as shown in FIGS. 8 and 9, the electromagnet 103 includes a hollow, substantially cylindrical bobbin 131 and an electric coil 132 wound around the bobbin, and the electric coil is provided on the substrate 106. It is connected to switching means (not shown) via the terminal 132a. One end of a pair of elongated first magnetic bodies 133 and 134 having a rectangular cross-sectional shape is inserted into the inner periphery of the bobbin 131. The other end of each of the first magnetic bodies 133 and 134 has a semicircular shape centered on the optical axis. It extends and is arranged on the holder 111.
[0055]
Incidentally, as shown in FIGS. 10 to 11, a horizontal flange portion 111a is formed on the outer periphery of the holder 111, and a pair of positioning portions 111e centered on the optical axis are provided above the horizontal flange portion. 111f is formed. Grooves 111g and 111h are formed on the outer periphery of the positioning portions 111e and 111f at positions facing the N-pole and S-pole regions divided into two on the circumference of the permanent magnet 102 from below, respectively. The first magnetic bodies 133 and 134 are inserted into the grooves 111g and 111h, and are positioned on the holder 111 by the positioning portions 111e and 111f and the grooves.
[0056]
Next, the second magnetic body 104 will be described. As shown in FIG. 8, the second magnetic body 104 has a disk shape having an opening hole at the center, and three outwardly protruding projections 104b are provided on the outer periphery of the disk in the circumferential direction. It is provided at equal intervals along. On the other hand, a cylindrical portion 111b is formed on the outer peripheral portion of the horizontal flange portion 111a of the holder 111, and an opening 111i for disposing the first magnetic bodies 133 and 134 on the holder 111 is formed in the cylindrical portion. ing. In addition, on the upper end surface 111c of the cylindrical portion 111b, slope portions 111d whose height in the optical axis direction changes along the circumferential direction are formed at three equally spaced positions along the circumferential direction. The second magnetic body 104 is mounted on the cylindrical portion 111b of the holder 111 such that the three protrusions 104b abut on the slope 111d. Therefore, when assembling the second magnetic body 104 to the cylindrical portion 111b of the holder 111, the height of the second magnetic body in the optical axis direction is increased by rotating the second magnetic body in the circumferential direction. Therefore, the initial position of the second magnetic body in the optical axis direction, that is, the macro imaging position of the lens holder 112 can be initialized.
[0057]
Next, the operation of the above-described solid-state imaging device will be described. When a current is applied to the electromagnet 103 and the pair of first magnetic bodies 133 and 134 each having one end inserted into the bobbin 131 are magnetized into N and S poles, respectively, the pair of first magnetic bodies When the N pole and the S pole of the opposing permanent magnet 102 are the same magnetic pole, as shown in FIG. 10, the permanent magnet is repelled upward to abut on the second magnetic body 104. Let it. When the current flowing through the electromagnet 103 is turned off in this state, the magnetic force of the permanent magnet 102 itself causes the permanent magnet 102 to be attracted and held on the contact surface of the second magnetic body 104. Thus, the lens holder 112 is driven and held at the macro imaging position.
[0058]
In this embodiment, as in the first embodiment, the holding force of the lens holder 112 at the normal imaging position is larger than the holding force of the lens holder 112 at the macro imaging position. That is, the attraction force acting between the permanent magnet 102 and the pair of first magnetic bodies 133 and 134 is larger than the attraction force acting between the permanent magnet 102 and the second magnetic body 104. . This can be realized, for example, by making the contact area between the permanent magnet 102 and the pair of first magnetic bodies 133 and 134 larger than the contact area between the permanent magnet 102 and the second magnetic body 104.
[0059]
This prevents the lens holder 112 from being inadvertently displaced from the normal imaging position when capturing the subject image at the normal imaging position that is more frequently used than the macro imaging position, thereby preventing the subject image from being accurately captured. it can. When the macro imaging position is used more frequently than the normal imaging position, the holding force of the lens holder 112 at the macro imaging position may be larger than the holding force of the lens holder 112 at the normal imaging position.
[0060]
Next, when the direction of the current of the electromagnet 103 is switched by switching means (not shown), the pair of first magnetic bodies 133 and 134 become magnetic poles different from the N pole and the S pole of the opposing permanent magnet 102, respectively. The permanent magnet is attracted downward, is separated from the second magnetic body 104 as shown in FIG. 11, and is attracted to the first magnetic bodies 133 and 134. When the current of the electromagnet 103 is turned off in this state, the electromagnet 103 is attracted and held on the contact surface of the second magnetic body 104 by the magnetic force of the permanent magnet 102 itself. Thus, the lens holder 112 is driven and held at the normal imaging position.
[0061]
Therefore, by changing the direction of the current flowing through the electromagnet 103 by a switching means (not shown) such as a changeover switch, the lens holder 112 can be accurately and reliably driven between the macro imaging position and the normal imaging position. Can be. Further, once the lens holder 112 is driven between the macro imaging position and the normal imaging position, even if the current is cut off, the lens holder 112 is held at each position by the magnetic force of the permanent magnet 102 itself as described above, so that significant power saving is achieved. Becomes possible.
[0062]
In addition, a pair of first magnetic bodies 133 and 134 that are magnetized into different magnetic poles by energizing the electromagnet 3 are opposed to different magnetic poles of the permanent magnet 102 in the optical axis direction, respectively. Since the attractive force and the repulsive force are simultaneously generated with respect to the magnetic pole, the driving force of the permanent magnet is increased, and the permanent magnet can be driven more reliably.
[0063]
Further, since the first magnetic members 133 and 134 are arc-shaped, by arranging the first magnetic members 133 and 134 in accordance with the shape of the ring-shaped permanent magnet 102, the facing area between the first magnetic member and the permanent magnet increases, The driving force of the permanent magnet can be increased. In addition, since the first magnetic body can be arranged along the outer circumference of the lens holder 112 and the holder 111, the size of the solid-state imaging device can be reduced.
[0064]
Further, since the holder 111 is formed with the positioning portions 111e and 111f for positioning the first magnetic members 133 and 134, it is possible to prevent the fixed position of the first magnetic member from being shifted, and to prevent the first magnetic member from being shifted. It is possible to prevent a reduction in the driving force of the permanent magnet 102 due to the positional deviation.
[0065]
In addition, since the second magnetic body 104 can move in the optical axis direction with respect to the holder 111 by rotating along the inclined surface 111d, the position of the second magnetic body in the optical axis direction can be adjusted. In addition, the macro imaging position can be easily corrected irrespective of the dimensional tolerance of each part.
[0066]
Further, since the permanent magnet 102 has a ring shape centered on the optical axis of the lens 113, the weight balance is good, and the lens holder 112 can be driven stably without the optical axis of the lens 113 being inclined.
[0067]
Further, since the ring member 121 made of a magnetic material is provided on the inner periphery of the permanent magnet 102 having different magnetic poles in the region where the circumference and the radial direction are respectively divided into two, a closed magnetic path is formed on the inner periphery side, Leakage of magnetic flux inside the permanent magnet 102 can be prevented, and the permanent magnet can be driven more reliably.
[0068]
In addition, since the lens holder 112 is formed with the guide groove 112a that engages with the cylindrical portion 111j in the optical axis direction, the lens holder 112 can be configured with a simple configuration without using a special mechanism for guiding the lens holder. It can guide movement in the optical axis direction. Further, by the engagement between the guide groove and the cylindrical portion, unnecessary intrusion of light from the outside can be prevented.
[0069]
Further, since the magnet holder 115 is movably screwed to the lens holder 112 along the optical axis direction, by rotating the lens holder or the magnet holder, the permanent magnet 102 in the optical axis direction with respect to the lens holder is rotated. The position, that is, the focus of the solid-state imaging device can be adjusted.
[0070]
As shown in FIGS. 8 and 9, a hemispherical projection 104 a having a predetermined height is formed on a surface of the second magnetic body 104 facing the permanent magnet 102. The second magnetic body is in contact with the second magnetic body through the top of the projection. Therefore, it is possible to prevent the attraction force to the second magnetic body 104 from becoming excessive, and it is possible to reliably separate the permanent magnet 102 in the opposite direction. If a similar projection is also formed on the attraction surface of the first magnetic body 133, 134, the permanent magnet 102 can be reliably separated from the first magnetic body.
[0071]
In this embodiment, the ring member 121 made of a magnetic material is provided on the inner periphery of the permanent magnet 102. However, the means for canceling the magnetic pole on the inner periphery side of the permanent magnet is not limited to this, and can be changed as appropriate. is there. For example, the magnet holder 115 may be formed of a magnetic material and arranged along the inner circumference of the permanent magnet.
[0072]
Further, in the present embodiment, the permanent magnet 102 having different magnetic poles in the region where the circumferential direction and the radial direction are respectively divided into two is used as the permanent magnet. However, the permanent magnet is not limited to this. Permanent magnets having different magnetic poles in a region obtained by dividing the circumference into four parts as shown in the embodiment may be used.
[0073]
Further, in the present embodiment, the number of the positioning portions 111e and 111f for positioning the first magnetic bodies 133 and 134 is two, but the number of the positioning portions may be two or more.
[0074]
In each embodiment, the first and second positions are the normal imaging position and the macro imaging position, respectively. However, the first and second positions are not limited to these.
[0075]
Further, in each of the above-described embodiments, the permanent magnets 2 and 102 are not limited to ring-shaped ones, and two magnets are provided on the outer circumference of the magnet holders 15 and 115 so that the same magnetic poles are located on the outer sides. A configuration provided at an interval may be used. Also, a U-shaped magnet can be used instead of the ring shape.
[0076]
Further, the present invention can be easily applied not only to the case where the CCD elements as described above are used as the imaging elements 61 and 162 but also to the case where, for example, a CMOS element or a normal film is used.
[0077]
【The invention's effect】
First, since the permanent magnet attached to the lens holder is merely moved in the optical axis direction by the magnetic force of the electromagnet, the structure can be made extremely simple and small. Second, by adsorbing the permanent magnet to the first magnetic body or the second magnetic body, the focal length between the macro imaging position and the normal imaging can be set accurately. Third, by simply switching the current direction of the electromagnet, the focal length can be changed instantaneously and with low noise. Fourth, by disposing only one magnetic pole of the permanent magnet between the first magnetic body and the second magnetic body having different magnetic poles, both the repulsive force of magnetic force and the attractive force are used. Therefore, the lens holder can be moved more strongly.
[0078]
Fourth, even if the current is turned off, the permanent magnet is attracted and held by the first magnetic body or the second magnetic body by its own magnetic force. Good. Therefore, significant power saving can be achieved. Fifth, by providing projections on the attraction surfaces of the first magnetic body and the second magnetic body, the magnetic attraction force of the permanent magnet is prevented from becoming excessive, and In addition, it is possible to prevent the second magnetic body from being difficult to separate from the attraction surface. Sixth, since the position of the permanent magnet or the second magnetic body can be adjusted in the optical axis direction, the initial setting of the focal position can be performed accurately and easily. Seventh, since the holding force of the lens holder at the normal imaging position is larger than the holding force of the lens holder at the macro imaging position, when the subject image is taken at the normal imaging position where use frequency is relatively high, Inadvertent displacement from the imaging position can be prevented.
[Brief description of the drawings]
FIG. 1 is a top view of a solid-state imaging device.
FIG. 2 is a cross-sectional view of the solid-state imaging device.
FIG. 3 is a top view in which the solid-state imaging device is rotated by 90 degrees.
FIG. 4 is a cross-sectional view in which the solid-state imaging device is rotated by 90 degrees.
FIG. 5 is a top view in which the solid-state imaging device is rotated by 90 degrees.
FIG. 6 is a cross-sectional view of the solid-state imaging device rotated by 90 degrees.
FIG. 7 is an explanatory view showing a method of magnetizing a permanent magnet.
FIG. 8 is a top view of another solid-state imaging device.
FIG. 9 is a cross-sectional view of another solid-state imaging device.
FIG. 10 is a cross-sectional view of another solid-state imaging device rotated by 90 degrees.
FIG. 11 is a cross-sectional view in which another solid-state imaging device is rotated by 90 degrees.
FIG. 12 is an explanatory view showing a method of magnetizing a permanent magnet.
FIG. 13 is a sectional view of a lens driving device according to a conventional example.
[Explanation of symbols]
1, 101 lens unit
11, 111 holder
12, 112 Lens holder
121 ring member
13, 113 lenses
2,102 permanent magnet
3,103 electromagnet
132 electric coil
133 1st magnetic body
134 first magnetic body
4,104 Second magnetic body
104a protrusion
104b protrusion
5 First magnetic body
6,106 substrates
61, 161 CCD (imaging device)

Claims (16)

A substrate on which the imaging element is mounted, and a lens unit that holds a lens mounted on the substrate and forming a subject image on the imaging element,
The lens unit includes a holder fixed to the substrate so as to surround the imaging element, a lens holder that holds the lens and is movable in the optical axis direction, A solid-state imaging device comprising: an electromagnetic driving means for driving the first position to a second position moved by a predetermined distance in the optical axis direction from the first position. 2. The electromagnet according to claim 1, wherein the electromagnetic driving means includes: an electromagnet; a first magnetic body magnetized by energizing the electromagnet; and a second magnetic body facing the first magnetic body in the optical axis direction. And a permanent magnet provided on the lens holder between the first magnetic body and the second magnetic body,
The permanent magnet is driven to the first position where it is attracted to the first magnetic body or the second position where it is attracted to the second magnetic body in accordance with the energization of the electromagnet. Solid-state imaging device. In claim 2, the permanent magnet has a different magnetic pole portion in a direction orthogonal to the optical axis direction,
The solid-state imaging device according to claim 1, wherein the second magnetic body is magnetized to a magnetic pole different from that of the first magnetic body by energizing the electromagnet. The solid-state imaging device according to claim 3, wherein the electromagnet is provided on the holder along an outer periphery of the lens holder. 5. The solid-state imaging device according to claim 3, wherein only one magnetic pole of the permanent magnet is disposed between the first magnetic body and the second magnetic body. 6. . In claim 2, the permanent magnet has a different magnetic pole portion in a direction orthogonal to the optical axis direction,
The first magnetic body includes a pair of magnetic bodies that are arranged side by side in a direction orthogonal to the optical axis direction and that are magnetized to different magnetic poles by energizing the electromagnet,
One of the magnetic bodies is arranged to face one magnetic pole portion of the permanent magnet in the optical axis direction,
The solid-state imaging device according to claim 1, wherein the other one of the magnetic members is arranged to face the other magnetic pole portion of the permanent magnet in an optical axis direction. 7. The solid-state imaging device according to claim 6, wherein the first magnetic body has an arc shape. The solid-state imaging device according to claim 6, wherein the holder has a positioning portion that positions the first magnetic body. The solid-state imaging device according to any one of claims 6 to 8, wherein the second magnetic body is engaged with the holder so as to be position-adjustable in the optical axis direction. 10. The method according to claim 2, wherein at least one of the first magnetic body and the second magnetic body has a projection at a position where the permanent magnet is attracted. Solid-state imaging device. The permanent magnet according to any one of claims 2 to 10, wherein the permanent magnet has a ring shape around the optical axis of the lens, and has different magnetic pole portions along the circumferential direction. Characteristic solid-state imaging device. 12. The solid-state imaging device according to claim 11, wherein the permanent magnet has different magnetic pole portions in a radial direction, and a ring member made of a magnetic material is provided inside the permanent magnet. The solid-state imaging device according to claim 1, wherein the lens holder is movably engaged with the holder in the optical axis direction. 14. The solid-state imaging device according to claim 13, wherein at least one of the lens holder and the holder is provided with a guide groove for guiding the movement of the lens holder. In any one of claims 1 to 14, the first position is a normal imaging position for imaging a subject image located in a normal imaging region,
The solid-state imaging device according to claim 1, wherein the second position is a macro imaging position for imaging a subject image located in a short-distance imaging region. 16. The solid-state imaging device according to claim 15, wherein a holding force of the lens holder at the normal imaging position is larger than a holding force of the lens holder at the macro imaging position.

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