JP2012060266A - Imaging apparatus and network camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure long term reliability and implement low vibration and compactness.SOLUTION: A first magnetization part 61 is disposed in flush with an outer circumferential surface of a magnetic support ring 52 disposed on an outer circumferential side of an optical member 51, a second magnetization part 62 is disposed in flush with an axially upper end face of the support ring 52, and a third magnetization part 63 is disposed in flush with an axially lower end face of the support ring 52. The first magnetization part 61 is magnetized in polar anisotropic orientation in an axially middle region of the outer circumferential surface of the support ring 52 with unmagnetized regions in between the second and third magnetization parts 62, 63. The second and third magnetization parts 62, 63 thus have a greater width and a correspondingly greater magnetic force independently of the magnetic field of the first magnetization part 61.

Description

  The present invention relates to an optical image formed on a light receiving surface of an image sensor and an image sensor by rotationally driving a rotating body that can be displaced in the axial direction and the radial direction while controlling the axial position and the radial position. The present invention relates to an imaging apparatus and a network camera system suitable for generating a high-resolution image by super-resolution processing from a plurality of original images acquired by so-called pixel shift, in which imaging is performed with relatively small displacements.

  The imaging device employs a two-dimensional image sensor in which pixels are arranged in a matrix. In this two-dimensional image sensor, the resolution depends on the size and the number of pixels. On the other hand, it is higher than the original resolution of the image sensor from a plurality of original images acquired by so-called pixel shifting, which is performed while relatively displacing the optical image formed on the light receiving surface of the image sensor and the image sensor. A technique for generating a resolution image is conventionally known.

  In such a technique for increasing the resolution by shifting pixels, a shift mechanism (hereinafter referred to as “optical shift mechanism”) that relatively displaces the optical image and the image sensor is referred to as “optical shift”. For example, a technique for minutely displacing the image sensor with an actuator made of a piezo element is known (see Patent Document 1).

  In addition, a parallel plate is disposed between the image pickup optical system and the image pickup device so as to be inclined with respect to the optical axis of the image pickup optical system, and the parallel plate is rotated around the optical axis so as to be on the light receiving surface of the image pickup device. There is a technique for shifting the position of an optical image (see Patent Documents 2 and 3).

  Further, as an image processing method for generating a high-resolution image from a plurality of original images acquired by pixel shifting, an image shift process for mapping pixel values of a low-resolution image to pixels of a high-resolution image, or an ML (Maximum-likelihood) method A super-resolution technique using a MAP (Maximum A Posterior) method, a POCS (Projection On to Convex Sets) method, or the like is known (see Patent Document 1).

JP 2008-306492 A JP 2000-125170 A JP 2000-278614 A

  By the way, when such a technique for increasing the resolution by shifting pixels is applied to, for example, a surveillance camera system, if a high-resolution image is required for verification purposes of traffic accidents, a high-resolution image is saved from the stored low-resolution image. Since a resolution image can be obtained, convenience can be improved.

  When an imaging apparatus is used for such a surveillance camera, long-term reliability (long life) is required, which enables stable operation even for long-term continuous operation, for example, 10 years. Moreover, low noise is desired so that it can be used without any trouble even in a quiet environment. However, as in the prior art disclosed in Patent Documents 2 and 3, the configuration in which the driving force of the motor is transmitted to the parallel plate using a gear mechanism to rotate the parallel plate sufficiently ensures long-term reliability. In addition, there was a limit to achieving low noise.

  In order to ensure long-term reliability and achieve low vibration, it is conceivable to apply the technology of a bearingless motor. For example, as disclosed in Japanese Patent Laid-Open No. 2010-41742, this bearingless motor is a brushless motor in which the function of a magnetic bearing is integrated and a mechanical bearing is omitted. Since the (rotor) generates a predetermined torque to drive the shaft, the shaft and the permanent magnet for rotational driving must be connected by a highly rigid back yoke, which causes a problem that the apparatus becomes large. It was. In addition, it is necessary to provide a permanent magnet for adjusting the axial position of the rotating body at a position away from the permanent magnet for rotational driving, and it is difficult to increase the size of the permanent magnet for axial position adjustment. The magnetic force for controlling the axial position of the body could not be increased, and stable axial position control could not be performed.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to ensure long-term reliability, achieve low vibration and reduce the size of the device, and rotate. Providing an imaging device that realizes a highly accurate optical shift mechanism by reducing the change in the angle with respect to the optical axis by stably controlling the position of the body in the optical axis direction and reducing the effect on the optical shift amount The main purpose is to do.

  An imaging apparatus according to the present invention includes an imaging element that photoelectrically converts light from a subject and outputs a pixel signal, a lens unit that forms an image of light from the subject on the imaging element, and an optical axis of the lens unit. And a rotating body having a support ring made of a magnetic body provided on the outer peripheral side of the optical member, and rotating the rotating body to change the tilting direction of the optical member with respect to the optical axis. A rotation drive device that relatively displaces the optical image formed on the light receiving surface of the image pickup device and the image pickup device, and the rotation drive device has one end surface in the axial direction of the support ring. A second magnetized portion provided on the support ring so as to face the third ring, a third magnetized portion provided on the support ring so as to face the other end surface in the axial direction of the support ring, and the support ring On the outer surface of As described above, by applying an axial magnetic force to at least one of the first magnetized portion, the second magnetized portion, and the third magnetized portion provided in the support ring, the shaft of the optical member A second position control unit that controls the directional position to a floating state, and a first position that controls the radial position of the optical member to a floating state by applying a radial magnetic force to the first magnetized unit. A control unit; and a magnetic rotation driving unit that rotates the optical member by applying a magnetic force in a rotation direction to the first magnetized unit, wherein the first magnetized unit is an outer peripheral surface of the support ring. It is set as the structure magnetized by polar anisotropic orientation so that it may face the center site | part of the axial direction in.

  In the network camera system of the present invention, the imaging device having the above-described configuration and the image processing device are connected to each other via a network, and the imaging device specifies a rotational movement of the rotating body by the rotation driving device at a specified cycle. Shift control means for performing image capturing by the image pickup device, image pickup control means for performing image pickup by the image pickup device at a specified cycle, and transmission means for transmitting frame images sequentially generated by image pickup by the image pickup device to the image processing apparatus. The image processing apparatus includes a receiving unit that receives a frame image transmitted from the imaging device, and a super-resolution processing unit that generates a high-resolution image from a plurality of frame images received by the receiving unit. And

  According to the present invention, since the radial position and the axial position of the rotating body are controlled by the first and second position control units, a mechanical bearing is not required, and the rotation driving device has a long life and low vibration. Can be realized. Further, since the optical member and the support ring that constitutes a part of the rotary drive device are directly connected, the device can be downsized. The first magnetized portion is magnetized in a polar anisotropic orientation so as to face the axial central portion of the outer peripheral surface of the support ring, thereby avoiding interference with the magnetic force of the first magnetized portion. However, since the second and third magnetized portions can be extended to the outer peripheral edge of the support ring, the axial position control of the rotating body can be increased to enable stable axial position control. . Therefore, the rotating body can be maintained at a constant angle with respect to the optical axis, and the quality (substantial resolution) of the high resolution image generated by the image processing apparatus can be improved.

Overall configuration diagram of network camera system according to the present invention FIG. 1 is a block diagram illustrating a schematic configuration of an imaging apparatus and an image processing apparatus illustrated in FIG. Schematic diagram showing the processing status in the imaging apparatus and image processing apparatus shown in FIG. 1 is a longitudinal sectional view showing an imaging unit of an imaging apparatus including a rotation driving device according to a first embodiment of the present invention. Illustration of orientation of easy axis in anisotropic magnet Cross section of the main part of the rotating body schematically showing the magnetic force when magnetized in anisotropic orientation FIG. 4 is a plan view of the optical shift mechanism shown in FIG. The top view which shows the example which applied the rotational drive apparatus shown in FIG. 7, and the three-phase motor of the conventional structure used as the origin of the rotational drive apparatus Configuration diagram of the shift control unit shown in FIG. The figure which shows the principal part and shift control part of the rotational drive apparatus shown in FIG. Sectional drawing which shows the incident condition of the light to the image pick-up element shown in FIG. Schematic diagram showing the relative circular motion of the pixels relative to the light image Schematic diagram showing the relative circular motion of the pixels relative to the light image Schematic diagram showing the state of imaging and the image generated by this Schematic diagram showing the situation of the imaging reference position in an example of the ratio between the imaging period and the circular motion period Sectional drawing of the principal part of the rotational drive apparatus which concerns on 2nd Embodiment of this invention.

  A first invention made to solve the above problems is an image sensor that photoelectrically converts light from a subject and outputs a pixel signal; a lens unit that forms an image of light from the subject on the image sensor; An optical member inclined at a predetermined angle with respect to the optical axis of the lens unit, a rotating body having a support ring made of a magnetic body provided on the outer peripheral side of the optical member, and the rotating body is rotated to rotate the optical member. An image pickup apparatus comprising: a rotation drive device that relatively displaces the light image formed on the light receiving surface of the image pickup element and the image pickup element by changing a tilt direction with respect to the optical axis; The rotation drive device is provided on the support ring so as to face a first magnetized portion provided on the support ring so as to face an outer peripheral surface of the support ring and an end surface in the axial direction of the support ring. Second By applying a magnetic force in the radial direction to the magnetized portion, a third magnetized portion provided on the support ring so as to face the other end surface in the axial direction of the support ring, and the first magnetized portion By applying an axial magnetic force to at least one of the first position control unit that controls the radial position of the optical member in a floating state, the second magnetized unit, and the third magnetized unit. A second position control unit that controls the axial position of the optical member in a floating state; and a magnetic rotation driving unit that rotates the optical member by applying a magnetic force in a rotational direction to the first magnetizing unit. And the first magnetized portion is magnetized in a polar anisotropic orientation so as to face the axial central portion of the outer peripheral surface of the support ring.

  According to this, since the radial position and the axial position of the rotating body are controlled by the first and second position control units, a mechanical bearing is unnecessary, and a long life and low vibration rotational drive device is realized. can do. Further, since the optical member and the support ring that constitutes a part of the rotary drive device are directly connected, the device can be downsized. The first magnetized portion is magnetized in a polar anisotropic orientation so as to face the axial central portion of the outer peripheral surface of the support ring, thereby avoiding interference with the magnetic force of the first magnetized portion. However, since the second and third magnetized portions can be extended to the outer peripheral edge of the support ring, the axial magnetic force applied by the second position control portion is increased and stable axial position control is achieved. Is possible.

  Further, since the first magnetized portion is magnetized in the polar anisotropic orientation, the magnetic force of the first magnetized portion can be made higher than that in the non-polar anisotropic orientation, and the rotating body Since the change in magnetic force associated with the rotation can be made a waveform close to a sine wave, the accuracy of the radial position control and rotation control of the rotating body can be improved.

  In a second aspect based on the first aspect, the first magnetized portion is provided on a first ring member, and the second magnetized portion is provided on a second ring member, The third magnetized portion is provided on the third ring member, and the second ring member and the third ring member are bonded to the axial end surface of the first ring member.

  According to this, since it is sufficient to provide each magnetized portion separately on one ring member, it is easy to magnetize the ring member. Moreover, since it is easy to increase the magnetic field at the time of magnetizing each ring member, the magnetic force of the magnetized portion can be increased. Accordingly, the radial position magnetic force applied by the first position control unit and the axial direction magnetic force applied by the second position control unit can be increased to enable stable position control of the rotating body.

  In a third aspect based on the first aspect, the second magnetized portion, the third magnetized portion, and the first magnetized portion are provided in a single ring member. The configuration.

  According to this, since there is no need to bond the magnetized ring members together, it is possible to eliminate concerns such as peeling of the ring members due to deterioration of the adhesive, and it is possible to further improve the reliability for long-term use.

  According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the rotary drive device further includes a capsule member that encloses the rotating body and encloses a fluid having a higher refractive index than air. The rotating body is configured to rotate in a non-contact state with other than the fluid.

  According to this, the structure in which the rotating body is integrated by the capsule member facilitates the handling, and prevents the intrusion of dust and the like around the optical member, thereby reducing the relative displacement accuracy between the optical image and the image sensor ( Image quality deterioration). In addition, it is possible to reduce the influence of the change in the angle of the optical member with respect to the optical axis on the relative displacement between the optical image and the image sensor, and to realize a highly accurate optical shift mechanism.

  A fifth invention made to solve the above problem is a network camera system in which the imaging device and the image processing device are connected to each other via a network, and the imaging device is rotated and driven. Shift control means for performing the rotational movement of the rotating body by the apparatus at a specified cycle; imaging control means for performing imaging by the imaging device at a specified cycle; and frame images sequentially generated by imaging with the imaging device. A transmission means for transmitting to the image processing apparatus, the image processing apparatus receiving a frame image transmitted from the imaging apparatus, and a high-resolution image from a plurality of frame images received by the reception means. And a super-resolution processing means for generating.

  According to this, since the radial position and the axial position of the rotating body are controlled by the first and second position control units, a mechanical bearing is unnecessary, and a long life and low vibration rotational drive device is realized. can do. Further, since the optical member and the support ring that constitutes a part of the rotary drive device are directly connected, the device can be downsized. The first magnetized portion is magnetized in a polar anisotropic orientation so as to face the axial central portion of the outer peripheral surface of the support ring, thereby avoiding interference with the magnetic force of the first magnetized portion. However, since the second and third magnetized portions can be extended to the outer peripheral edge of the support ring, the axial magnetic force applied by the second position control portion is increased and stable axial position control is achieved. Is possible. Therefore, the rotating body can be maintained at a constant angle with respect to the optical axis, and the quality (substantial resolution) of the high resolution image generated by the image processing apparatus can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the term “axial direction” indicates the optical axis direction (corresponding to the vertical direction in FIG. 4), and the term “radial direction” is the direction orthogonal to the optical axis (corresponding to the horizontal direction in FIG. 4). It shall be shown. The radial direction can take any angle within 360 ° around the optical axis.

  FIG. 1 is an overall configuration diagram of a network camera system according to the present invention. As shown in FIG. 1, a network camera system to which the present invention is applied includes at least one imaging device (network camera) 1 and an image processing device (host device) 2. The imaging device 1 and the image processing device 2 are connected via the Internet, and imaging data generated by the imaging device 1 is transmitted to, for example, the image processing device 2 located in a remote place, and a video is displayed on the image processing device 2. Is done. Various command signals for controlling the imaging device 1 are transmitted from the image processing device 2 to the imaging device 1.

  The imaging data is transmitted from the imaging apparatus 1 to the image processing apparatus 2 using a so-called Internet protocol such as TCP (UDP) / IP. For example, the imaging data is encrypted and encapsulated, for example, VPN (Vertual As a network camera system called a so-called CCTV (Closed Circuit TV) in which the imaging device 1 and the image processing device 2 are connected in a one-to-one relationship by a dedicated line. Also good.

  FIG. 2 is a block diagram illustrating a schematic configuration of the imaging device and the image processing device 2 illustrated in FIG. 1. As shown in FIG. 2, the imaging device 1 includes an imaging unit 11, an image processing unit 12, a data compression / transmission unit 13, and a shift control unit 14. The imaging unit 11 includes an imaging element 31 that photoelectrically converts light from a subject and outputs an analog pixel signal. The image sensor 31 is a two-dimensional CMOS image sensor. Instead of this, a two-dimensional CCD image sensor may be used for the image sensor 31.

  The analog signal output from the image sensor 31 is converted into a digital signal by the A / D converter 32, and this digital signal is input to the image processing unit 12, where color correction, demosaic processing, gradation correction (γ correction). , YC separation processing and the like are performed and converted into image data. This image data is stored in the data compression / transmission unit 13 by, for example, H.264. The image data is transmitted to the image processing apparatus 2 after being subjected to compression processing such as H.264 or MPEG4.

  In addition, the imaging unit 11 includes an optical shift mechanism 35 that relatively slightly displaces the optical image formed on the light receiving surface of the imaging element 31 and the imaging element 31, and each part of the optical shift mechanism 35. These operations are controlled by the shift control unit 14.

  The configuration of the optical shift mechanism 35 and the control by the shift control unit 14 will be described in detail later. To explain the outline, an optical member (indicated by reference numeral 51 in FIG. 4) that slightly displaces the optical image is provided. The rotating body (indicated by reference numeral 53 in FIG. 4) is rotationally driven by a magnetic rotation driving unit 64, and the radial and axial positions of the rotating body are detected by the first and second magnetic sensors 65 and 66 and rotated. The radial and axial positions of the body are controlled by the first and second electromagnets 67 and 68, and the rotational position of the rotating body is detected by the origin sensor 70.

  The rotating body is provided with a magnetizing portion (indicated by reference numerals 61 and 62 in FIG. 4), and the first and second magnetic sensors 65 and 66 detect the magnetism of the magnetizing portion to detect the shift control portion. The shift control unit 14 controls the magnetic rotation driving unit 64 based on the position information of the rotating body indicated by the outputs of the magnetic sensors 65 and 66 to rotate the optical member, and the first and second The electromagnets 67 and 68 are controlled to hold the optical member at a predetermined position.

  The image processing apparatus 2 includes a data reception decoding unit 21, a display unit 22, a storage unit 23, a super-resolution processing unit 24, a period setting unit 25, and an input unit 26. The image processing apparatus 2 is configured by installing necessary application software in an information processing apparatus such as a personal computer or a workstation, or may be a dedicated apparatus such as a CCTV recorder.

  In the image processing device 2, the compressed image data transmitted from the imaging device 1 is received and decoded by the data receiving / decoding unit 21, converted into RGB image data, and displayed in real time by a display or the like. 22 is displayed. Further, the RGB image data is sent to the storage unit 23 composed of a hard disk drive device or the like, temporarily accumulated therein, and can be read from the storage unit 23 and reproduced on the display unit 22 as necessary.

  For example, when a high-resolution image is necessary for verification of traffic accidents, etc., the image data is read from the storage unit 23 and super-resolution processing is performed by the super-resolution processing unit 24 so that the high-resolution image is obtained. (Still image) can be generated and the high resolution image can be displayed on the display unit 22.

  As will be described in detail later, the input unit 26 receives an input of an imaging cycle from the user and sends it to the cycle setting unit 25. The cycle setting unit 25 determines a circular motion cycle based on the imaging cycle sent from the input unit 26 and transmits a command signal related to the circular motion cycle to the imaging device 1. The shift control unit 14 of the imaging apparatus 1 drives the optical member at a rotational speed corresponding to the designated circular motion cycle by operating the optical shift mechanism 35 based on the command signal related to the circular motion cycle.

  FIG. 3 is a schematic diagram illustrating processing states in the imaging device 1 and the image processing device 2. As shown in FIG. 3, the image sensor 31 is driven by a drive circuit 33, and performs imaging (sampling) at a constant cycle (hereinafter, imaging cycle) in accordance with a timing signal generated by the drive circuit 33. For example, when generating 30 frame images per second at a frame rate of 30 frames / sec, the imaging cycle is set to about 30 ms.

  The super-resolution processing unit 24 of the image processing apparatus 2 performs super-resolution processing for generating a high-resolution image from a plurality of temporally continuous frame images. In this super-resolution processing, first, the frame image stored in the storage unit 23 is displayed as a still image by frame advance. Then, when the reference image is designated by the user from among them, the frame image serving as the reference image and a plurality of frame images before and after the frame image are read from the storage unit 23 and sent to the super-resolution processing unit 24 for super Resolution processing is performed.

  As super-resolution processing, for example, ML (Maximum-likelihood) method, MAP (Maximum A Posterior) method, POCS (Projection On to Convex Sets) method, etc. are adopted and realized by executing application software on CPU. Is done. In general, since the super-resolution processing has a large amount of calculation, a part of the processing may be performed using a GPU (Graphics Processing Unit) or dedicated hardware.

  Here, the ML method uses a square error between a pixel value of a low-resolution image estimated from a high-resolution image and an actually observed pixel value as an evaluation function, and a high resolution that minimizes this evaluation function. This is a method of using an image as an estimated image. That is, the ML method is a super-resolution processing method based on the principle of maximum likelihood estimation. The MAP method is a method for estimating a high-resolution image that minimizes an evaluation function obtained by adding probability information of a high-resolution image to a square error. That is, the MAP method is a super-resolution processing method that estimates a high-resolution image as an optimization problem that maximizes the posterior probability by using some foresight information for the high-resolution image. The POCS method is a super-resolution processing method for obtaining a high-resolution image by creating simultaneous equations regarding pixel values of a high-resolution image and a low-resolution image and sequentially solving the equations.

  These super-resolution processes first assume a high-resolution image, and based on the point spread function (PSF function) obtained from the camera model from the assumed high-resolution image, for all pixels of the low-resolution image, It has a process of estimating a pixel value and searching for a high-resolution image such that the difference between the estimated value and the observed pixel value (observed value) is small. Therefore, these super-resolution processes are called reconfigurable super-resolution processes.

  Here, the process of searching for a high-resolution image is to search for a position corresponding to a pixel obtained as a low-resolution image in the high-resolution image, and is a process called “alignment”. In general, in super-resolution processing, even if the change in pixel position between a plurality of low-resolution images is unknown, it is possible to increase the resolution, so that the alignment processing is repeatedly performed over a wide range around the pixel of interest. For this reason, it is known that the calculation cost becomes extremely high. On the other hand, as described in detail later, in the present invention, the position of the pixel shifted by the optical shift mechanism 35 is known, and each frame image, that is, a low-resolution image is captured at the known position. For at least a stationary subject, much of the alignment processing can be omitted by optical shift, and the calculation cost can be greatly reduced.

  Note that super-resolution processing that uses image information that spans a plurality of temporally continuous frames may be particularly referred to as inter-frame reconstruction type super-resolution processing. On the other hand, when the reconstruction type super-resolution processing is performed within one frame, it is called intra-frame reconstruction type super-resolution. In this embodiment, inter-frame reconstruction type super-resolution is adopted.

  Here, the still image that has been increased in resolution by the super-resolution processing is reproduced in the image processing device 2, but if the processing capability of the image processing device 2 is sufficiently high, the high resolution obtained by the super-resolution processing is obtained. It is also possible to reproduce a moving image using a resolution image as a frame image.

<First Embodiment>
FIG. 4 is a longitudinal sectional view showing the imaging unit 11 of the imaging apparatus 1 according to the first embodiment of the present invention.

  As illustrated in FIG. 4, the imaging unit 11 of the imaging device 1 forms an image on the light receiving surface 31 a of the imaging device 31 with light from a sensor module 41 provided with the imaging device 31 and a subject (not shown). A lens unit 42 and an optical shift mechanism 35 for displacing a light image formed on the light receiving surface 31a of the image sensor 31 are provided. The lens unit 42 is supported on the substrate 46 via the lens holder 45. The sensor module 41 and the optical shift mechanism 35 are also supported by the substrate 46. Note that other electrical components and the like are mounted on the substrate 46 as necessary.

  The optical shift mechanism 35 includes a rotating body 53 including an optical member 51 and a support ring 52 provided on the outer peripheral side, and a rotation driving device 54 that rotationally drives the rotating body 53. The rotating body 53 is accommodated in an optical capsule (capsule member) 55, and a liquid 56 is sealed inside the optical capsule 55. Therefore, the rotating body 53 is rotationally driven by the rotational driving device 54 in a floating state that can be displaced in the axial direction and the radial direction in the liquid 56.

  The optical member 51 has a substantially disc shape, and a parallel plate 57 inclined at a predetermined angle with respect to the optical axis C of the lens unit 42 is provided at the center thereof. By rotating the parallel plate 57, the light image formed on the light receiving surface 31 a of the image sensor 31 can be slightly displaced relative to the image sensor 31. In addition, as a material of the optical member 51, not only optical glass but an acrylic resin etc. can also be used, for example.

  As the liquid 56 sealed in the optical capsule 55, a liquid having a refractive index higher than that of air and lower than that of the parallel plate 57 is employed. Thereby, the shift width by the parallel flat plate 57 becomes substantially smaller than the case where the parallel flat plate 57 is placed in the air. For this reason, the change of the optical shift amount caused by the tilt of the central axis of the parallel plate 57 due to the swinging of the optical member 51 in the optical capsule 55 can be suppressed.

  As the liquid 56 sealed in the optical capsule 55, an antifreeze liquid (for example, a mixture of polypropylene glycol and water) may be used. Thereby, the temperature range in which the imaging apparatus 1 can be used (for example, up to −20 ° C.) can be expanded, and the viscosity of the liquid 56 is increased. Therefore, the buffering action against external impact is improved and the optical member 51 is improved. Can be prevented from being damaged. Further, it is possible to easily adjust the refractive index of the liquid 56 only by adjusting the concentration of the antifreeze liquid, and a desired optical shift amount can be easily obtained.

  The optical capsule 55 has a constricted cross section at the center, a central portion 58 that defines a disc-shaped space with the optical axis C as the center, and a rectangular cross section that is continuous with the outer peripheral side of the central portion 58. And an annular portion 59 that defines an annular space. A parallel plate 57 is accommodated in the central portion 58, and an outer peripheral portion of the optical member 51, a support ring 52, and the like are accommodated in an annular portion 59 widened in the vertical direction.

  The optical capsule 55 is made of, for example, a transparent resin (preferably PPS described later) or a glass material. The entire optical capsule 55 does not need to be formed of a transparent material, and a portion corresponding to an optical path through which incident light from the lens unit 42 passes may be formed of the transparent material as described above. Further, the portion other than the portion corresponding to the optical path of the optical capsule 55 may be opaque (for example, black). Thereby, the so-called stray light in which unnecessary light enters the image sensor 31 can be blocked.

  The support ring 52 has an annular shape, and is disposed at the center portion in the axial direction and has a first ring member 52a that holds the optical member 51 on its inner peripheral side, and an upper end surface of the first ring member 52a. The second ring member 52b is fixed to the lower end surface of the first ring member 52a with an adhesive, and the third ring member 52c is fixed to the lower end surface of the first ring member 52a with the adhesive. The first ring member 52a has a rectangular cross section, and each of the second and third ring members 52b and 52c has an annular flat plate shape having the same diameter and width as the first ring member 52a, and is concentric. It is bonded to the first ring member 52a. Thus, the support ring 52 itself has an annular shape having a rectangular cross section.

  Each of the first to third ring members 52a, 52b, 52c is a so-called plastic magnet made of polyphenylene sulfide resin (PPS) in which minute magnetic particles are dispersed and mixed, and thereby a liquid 56 containing water. Even inside, water absorption and swelling are prevented. Further, by using the same resin material as a binder and using a plastic magnet, the second and third ring members 52b and 52c can be replaced with the first ring member 52a by using an adhesive having high adhesiveness to both members to be bonded. It can be adhered to the surface, improving reliability for long-term use. Similarly, if the same material as that of the binder of the first ring member 52a is used as the material of the optical member 51, the adhesiveness when the optical member 51 and the support ring 52 are bonded is improved, and the long-term use. Reliability can be improved.

  Here, neodymium is adopted as the magnetic particles of the first to third ring members 52a, 52b, 52c. A neodymium magnet has an extremely large magnetic force and can obtain a large driving torque, and thus is effective when the viscosity of the liquid 56 becomes large at low temperatures. On the other hand, since neodymium can be oxidized by water and cause rust, the surface of the support ring 52 is coated with a resin material to prevent contact with the liquid 56. The coating with the resin material may be performed before the second and third ring members 52b and 52c are fixed to the first ring member 52a or after the second ring members 52b and 52c are fixed to the first ring member 52a. Also good.

  The liquid 56 sealed in the optical capsule 55 is not limited to the antifreeze liquid. Any material may be used as long as it has a refractive index higher than that of air and a refractive index lower than that of the parallel plate 57. For example, water may be used. Further, the antifreeze liquid does not need to be aqueous, and for example, transparent silicone oil may be employed. In this case, since there is no possibility that rust is generated on the support ring 52 or the like, a rust prevention treatment such as resin coating is unnecessary.

  The binder used for the first to third ring members 52a, 52b, and 52c is not limited to PPS, and for example, polyamide resin such as 6 nylon, polyethylene resin, polypropylene resin, or the like can be used. Further, different resins may be used as binders for the first to third ring members 52a, 52b, and 52c. On the other hand, the magnetic particles used for the first to third ring members 52a, 52b, and 52c are not limited to neodymium, and for example, ferrite, samarium cobalt, and the like can also be used. Further, different magnetic particles may be used for the first to third ring members 52a, 52b, and 52c. In addition, since the rust does not generate | occur | produce when a ferrite is used as a magnetic body particle | grain, the resin coating mentioned above can be abbreviate | omitted.

  The rotation drive device 54 includes a first magnetized portion 61 provided on the support ring 52 so as to face the outer peripheral surface of the support ring 52 in the radial direction, and a support ring so as to face the upper end side in the axial direction of the support ring 52. A second magnetized portion 62 provided on the support ring 52, a third magnetized portion 63 provided on the support ring 52 so as to face the lower end side in the axial direction of the support ring 52, and a first magnetized portion 61. The rotational position of the rotating body 53 is controlled by applying a magnetic force in the radial direction to the first magnetizing section 61 and a magnetic rotation driving section 64 that rotates the rotating body 53 by applying a magnetic force in the rotating direction. A first electromagnet (first position controller) 67 and a second electromagnet (second electromagnet) that controls the axial position of the rotating body 53 by applying an axial magnetic force to the second magnetized section 62. Position control unit) 68 and rotating body 53 at a predetermined axial position. And a permanent magnet 69 for applying a magnetic force in the same direction as the second electromagnet 68 to the third magnetized part 63 to lifting.

  Further, the rotation drive device 54 is based on the first magnetic sensor 65 that detects the radial position of the rotating body 53 based on the magnetism of the first magnetized portion 61 and the magnetism of the second magnetized portion 62. And a second magnetic sensor 66 for detecting the axial position of the rotating body 53. The first electromagnet 67 controls the radial position of the rotating body 53 based on the detection result of the first magnetic sensor 65. On the other hand, the second electromagnet 68 controls the axial position of the rotating body 53 based on the detection result of the second magnetic sensor 66.

  More specifically, the first magnetized portion 61 has a pole on the outer peripheral side of the first ring member 52a so as to face the central portion of the outer peripheral surface of the first ring member 52a excluding both ends in the axial direction. Magnetized in anisotropic orientation. Thereby, the 1st ring member 52a is a permanent magnet.

  Here, polar anisotropic orientation will be described with reference to FIGS. FIG. 5 is an explanatory view of the orientation of the easy axis in the anisotropic magnet, FIG. 5 (A) is a plan view showing the polar anisotropic ring-shaped magnet 101, and FIG. 3 is a plan view showing a radial anisotropic ring-shaped magnet 102. FIG. FIG. 6 is a cross-sectional view of the main part of the rotating body 53 schematically showing the magnetic force when the first ring member 52a is magnetized in an anisotropic orientation, and FIG. 6 (A) shows the polar anisotropic orientation. FIG. 6B shows a case where the magnet is magnetized in a radial anisotropic orientation as a comparison.

  As shown in FIG. 5A, the polar anisotropic ring-shaped magnet 101 creates an orientation magnetic field along the circumferential direction of the ring-shaped magnetic member so as to have a required number of poles (eight poles here), By simultaneously forming the ring-shaped magnetic member forming the plastic magnet and aligning the easy magnetization axis of the magnetic fine particles with the direction of the magnetic force lines indicated by the arrows in the figure, no magnetic pole is formed on the inner peripheral surface side, only the outer peripheral surface side. Are magnetized so as to form a plurality of pairs (four pairs in this case) of magnetic poles in which N and S poles appear alternately along the circumferential direction.

  On the other hand, as shown in FIG. 5B, the radial anisotropic ring-shaped magnet 102 has the magnetic field oriented along the radial direction of the ring-shaped magnetic member alternately reversed along the circumferential direction of the ring-shaped magnet. By making the ring-shaped magnetic member at the same time as aligning the easy axis of magnetization of the magnetic fine particles in the direction of the line of magnetic force, the magnetic pole forming a pair of N and S poles on the outer peripheral surface and the inner peripheral surface in the circumferential direction. Magnetization is performed so that a total of 8 pairs of magnetic poles are formed on the inner and outer peripheral surfaces so as to appear alternately in 4 pairs.

  Therefore, in the polar anisotropic ring magnet 101, the magnetic force formed by the N pole and S pole on the outer peripheral surface is strong on the radially outer side of the ring magnet, that is, the magnetic flux density is increased, and the axial direction of the ring magnet is increased. It becomes weak on the side. On the other hand, in the radial anisotropic ring-shaped magnet 102, the magnetic force formed by the N pole and S pole on the outer peripheral surface is stronger than that of the polar anisotropy on the radially inner side and the axial side of the ring magnet. The outer diameter of the ring-shaped magnet is weaker than that of polar anisotropy.

  That is, if the first magnetized portion 61 is magnetized in a radial anisotropic orientation, the lines of magnetic force generated in the vicinity of the upper and lower ends of the first magnetized portion 61 are as shown in FIG. Since each of them faces in the vertical direction, it does not act on the first electromagnet 67, and there is a large amount of magnetic leakage. On the other hand, when the first ring member 52a is magnetized with polar anisotropy, as shown in FIG. 6A, the magnetic force generated by the first magnetized portion 61 is radially outward. Most of them can be applied to the first electromagnet 67 because they occur substantially horizontally. Therefore, the magnetic force of the first electromagnet 67 that acts on the first magnetized portion 61 to control the radial position of the rotating body 53 can be increased, and the accuracy of radial control of the rotating body 53 is increased. Can do.

  Further, in the radial anisotropic ring-shaped magnet 102, the surface magnetic flux density on the outer peripheral surface of the ring-shaped magnet is large near the boundary between the N pole and the S pole with respect to the displacement in the circumferential direction (rotation of the rotating body 53). In the polar anisotropic ring-shaped magnet 101, the surface magnetic flux density on the outer peripheral surface of the ring-shaped magnet changes sinusoidally with respect to the displacement in the circumferential direction. Therefore, the rotation angle of the rotating body 53 can be detected with high accuracy, and the rotational drive control of the rotating body 53 can be performed with high accuracy.

  Note that the inner diameter of the first ring member 52a is made smaller than the outer diameter of the optical member 51, and when the first ring member 52a is molded, the optical member 51 is set in a mold and integrally molded. Good. By doing in this way, the worry that the optical member 51 and the support ring 52 are separated due to deterioration of the adhesive or the like can be eliminated, and the reliability for long-term use can be further improved.

  The second and third magnetized portions 62, 63 create an orientation magnetic field along the vertical direction, and align the easy magnetization axes of the magnetic fine particles simultaneously with the molding of the ring member (plastic magnet), thereby making each ring member 52b, The entire upper surface of 52c is magnetized in an anisotropic orientation such that the entire area of the upper surface is the S pole and the entire lower surface is the N pole (see FIG. 10). Thereby, the 2nd and 3rd ring members 52b and 52c are permanent magnets.

  By configuring the support ring 52 in this way, a non-magnetized portion is interposed between the first magnetized portion 61 and the second and third magnetized portions 62, 63. The portion functions as a back yoke that easily becomes a magnetic path. As described above, the second and third ring members 52b and 52c have a uniform magnetic flux density distribution in the circumferential direction, while the first magnetized portion 61 has a magnetic flux density distribution that changes sinusoidally in the circumferential direction. Therefore, if the magnetic field of the first magnetized portion 61 affects the second and third magnetized portions 62 and 63, the accuracy of the axial position of the rotating body 53 decreases, but the first magnetized portion Since the non-magnetized part is interposed between the part 61 and the second and third magnetized parts 62 and 63, the influence of the magnetic field of the first magnetized part 61 is influenced by the second and third magnetized parts. It becomes difficult to reach the magnetic parts 62 and 63, and the position control of the rotating body 53 in the axial direction can be performed with high accuracy.

  Further, since there is a portion that is not magnetized between the first magnetized portion 61 and the second and third magnetized portions 62 and 63, interference with the magnetic force of the first magnetized portion 61 is prevented. It is possible to extend the second and third magnetized portions 62 and 63 to the outer peripheral edges of the second and third ring members 52b and 52c, respectively, while avoiding them. Therefore, the magnetic force of the 2nd and 3rd magnetized parts 62 and 63 can be strengthened, and the precision of the axial position control of the rotating body 53 by the 2nd electromagnet 68 and the permanent magnet 69 can be improved. Further, since the first to third magnetized portions 61, 62, and 63 may be provided separately on the first to third ring members 52a, 52b, and 52c, respectively, magnetization is easy and magnetized. It is also possible to increase the magnetic field at the time and maximize the magnetic force of each of the magnetized portions 61, 62, 63. This also improves the accuracy of position control of the rotating body 53 in the radial direction and the axial direction. can do.

  As described above, the rotating body 53 is configured to directly connect the support ring 52 constituting a part of the rotation driving device 54 to the optical member 51 without using a separate back yoke. The number of adhesion portions can be reduced, the optical capsule 55 can be downsized, and the imaging device 1 can be downsized.

  In addition, since the first to third ring members 52 a, 52 b, and 52 c are only attached to the optical member 51 in the rotating body 53, and it is not necessary to draw a conducting wire inside the optical capsule 55, the optical capsule 55 is sealed. Can increase the sex. Further, the independence of the optical capsule 55 as a member is increased, which is advantageous in the manufacturing process.

  FIG. 7 is a plan view of the optical shift mechanism 35 shown in FIG. FIG. 8A is a plan view of the rotary drive device 54 shown in FIG. 7, and FIG. 8B is a three-phase structure of the conventional configuration that is the basis of the rotary drive device 54 shown in FIG. It is a top view which shows the example which applied the motor. As shown in FIGS. 4 and 7, the magnetic rotation driving unit 64 includes a stator core 71 formed by laminating a plurality of electromagnetic steel strips, and a coil 72 wound around the stator core 71. The stator core 71 is provided in contact with the outer peripheral surface of the optical capsule 55, and is disposed to face the first magnetized portion 61 via the optical capsule 55.

  The rotary drive device 54 is a so-called inner rotor type three-phase motor, and the first magnetized portion 61 for generating a field is alternately arranged with N poles and S in the circumferential direction as shown in FIG. Eight magnetic poles magnetized on the poles are provided. On the other hand, three magnetic rotation driving units 64 are provided at equal intervals, and each stator core 71 includes two teeth 73. As shown in FIG. 8 (B), this rotary drive unit 54 has a 6-state 8-pole configuration in which three 2-core stator cores are removed at regular intervals from a 12-phase 8-pole conventional 3-phase motor. It has become.

  The coils 72 of the magnetic rotation drive unit 64 are star-connected (see FIG. 9), and the two coils 72 of each stator core 71 are two phases of three phases (u phase, v phase and w phase), specifically Specifically, they are set to u phase and v phase, v phase and w phase, and w phase and u phase, respectively.

  When the magnetic rotation driving unit 64 is energized by energizing the coil 72 of the magnetic rotation driving unit 64, an attractive force and a repulsive force are generated between the first magnetizing unit 61 and the rotating body in the optical capsule 55. The rotating body 53 can be rotated without contacting the 53. The configuration using this magnetic force is similar to the configuration of a so-called bearingless motor, there is no sliding portion, the rotary drive device 54 is driven with extremely low vibration, and a long life can be achieved. .

  FIG. 9 is a block diagram of the shift control unit 14 shown in FIG. As shown in FIG. 9, the coil 72 of the magnetic rotation driving unit 64 is driven by a three-phase driver 75 provided in the shift control unit 14. In the shift control unit 14, the speed command value is sent from the arithmetic processing unit 76 to the pulse width modulator (PWM) 77, and the pulse width modulator 77 calculates the ON duty ratio based on this speed command value, and this duty A PWM signal pulse-modulated based on the ratio is output to the three-phase driver 75. The three-phase driver 75 includes three systems of push-pull type transistor circuits 78 therein, and controls the current that flows through each coil 72 based on the PWM signal. As a result, the rotating body 53 is rotationally driven in a circular motion cycle instructed from the cycle setting unit 25 (see FIG. 2).

  As shown in FIG. 4, the first electromagnet 67 includes a first magnetic body 81 disposed so as to face the first magnetized portion 61, and a coil wound around the first magnetic body 81. 82. The first magnetic body 81 is formed by laminating a plurality of electromagnetic steel strips to suppress eddy currents, and is provided in a state of being in contact with the outer peripheral surface of the optical capsule 55.

  When the first electromagnet 67 is excited by energizing the coil 82 of the first electromagnet 67, repulsive force and attractive force are generated between the first electromagnet 67 and the first magnetized portion 61. Three first electromagnets 67 are arranged at equal intervals around the optical capsule 55 (see FIG. 7), and the rotating body is controlled by individually controlling the energization amount of each coil 82 of the first electromagnet 67. It is possible to adjust the radial magnetic force applied to 53 and to displace the rotating body 53 in an arbitrary radial direction. Thereby, the rotating body 53 is held at a predetermined radial position, that is, a radial position where the central axis of the optical member 51 substantially coincides with the optical axis C.

  The second electromagnet 68 includes a second magnetic body 83 disposed so as to face the second magnetized portion 62, and a coil 84 wound around the second magnetic body 83. The second magnetic body 83 is configured by laminating a plurality of electromagnetic steel strips to suppress eddy currents, and is provided in a state of being in contact with the outer surface of the upper wall of the optical capsule 55.

  The permanent magnet 69 is provided on the side opposite to the second electromagnet 68 with the optical capsule 55 interposed therebetween. The permanent magnet 69 is provided in contact with the outer surface of the lower wall of the optical capsule 55, and is disposed to face the third magnetized portion 63 via the optical capsule 55.

  The permanent magnet 69 and the third magnetized portion 63 are set so that the sides facing each other become the same magnetic pole (here, N pole) (see FIG. 10), and the permanent magnet 69 and the third magnetized portion. A repulsive force is generated between the rotating body 53 and the rotating body 53 in a state where it floats from the inner surface of the bottom wall of the optical capsule 55.

  The second electromagnet 68 and the second magnetized portion 62 are set so that the sides facing each other are the same magnetic pole (here, S pole) (see FIG. 10), and the coil 84 of the second electromagnet 68 is set. When the second electromagnet 68 is excited by energizing the current, a repulsive force is generated between the second electromagnet 68 and the second magnetized portion 62.

  Three second electromagnets 68 are arranged at equal intervals on one main surface of the optical capsule 55 (see FIG. 7), and the permanent magnet 69 is also in the same circumferential direction as the second electromagnet 68 on the other surface of the optical capsule 55. The three electromagnets 68 and the second electromagnet 68 are arranged at regular intervals (so as to overlap in the direction of the optical axis), and the energization amount of each coil 84 of the second electromagnet 68 is controlled. The rotating body 53 is held at a predetermined axial position by balancing the magnitude of the repulsive force generated between the magnetized portion 62 and the repulsive force generated between the permanent magnet 69 and the third magnetized portion 63. The

  Thus, since the second electromagnet 68 and the permanent magnet 69 cooperate to control the axial position of the rotating body 53, the axial position of the rotating body 53 can be controlled easily and with high accuracy. Here, the rotating body 53 is displaced to an axial position where the repulsive force of the second electromagnet 68 and the repulsive force of the permanent magnet 69 are balanced by uniformly controlling the energization amount of each coil 84 of the second electromagnet 68. However, it is possible to control such that the energization amount of each coil 84 of the second electromagnet 68 is individually controlled to suppress the swinging motion in which the center line of the rotating body 53 is inclined with respect to the optical axis C. is there. With such a configuration, for example, even when the lens unit 42 is configured as a so-called zoom lens system, the optical shift amount can be appropriately managed.

  In addition, it is also possible to generate an attractive force between the second electromagnet 68 and the second magnetized portion 62 and between the permanent magnet 69 and the third magnetized portion 63 and balance them. is there. In particular, in the configuration in which repulsive force is generated as described above, the rotating body 53 floats from the inner surface of the bottom wall of the optical capsule 55 by the magnetic force of the permanent magnet 69 even when the second electromagnet 68 is not excited. There is an advantage that the rotation of the rotating body 53 can be started smoothly at the time of startup or the like.

  In addition, a neodymium magnet may be used as the permanent magnet 69, but another magnet (for example, a ferrite magnet) may be used in consideration of the balance with the magnetic force generated by the upper second electromagnet 68.

  The first magnetic sensor 65 is composed of, for example, a Hall element. The first magnetic sensor 65 is disposed at the end of the first magnetic body 81 constituting the first electromagnet 67 on the side opposite to the first magnetized portion 61, and the first magnetic sensor 65. Is fixed to the surface of the first magnetic body 81, whereby the first magnetic sensor 65 and the first electromagnet 67 are integrated.

  When the first magnetic sensor 65 is arranged in this way, the first magnetic sensor 65 and the first electromagnet 67 overlap in the radial direction, so that the arrangement space is reduced and space saving can be achieved. The first magnetic sensor 65 detects the magnetism of the first magnetized portion 61 through the first magnetic body 81, that is, the magnetism of the first magnetized portion 61 is guided by the first magnetic body 81. Therefore, the detection accuracy of the first magnetic sensor 65 does not need to be lowered because it is guided to the first magnetic sensor 65.

  The second magnetic sensor 66 is composed of, for example, a Hall element. The second magnetic sensor 66 is disposed at the end opposite to the second magnetized portion 62 in the second magnetic body 83 constituting the second electromagnet 68, and the second magnetic sensor 66. Is fixed to the surface of the second magnetic body 83 so that the second magnetic sensor 66 and the second electromagnet 68 are integrated.

  When the second magnetic sensor 66 is arranged in this manner, the second magnetic sensor 66 and the second electromagnet 68 are overlapped in the axial direction, so that the arrangement space is reduced, and space saving can be achieved. Then, the second magnetic sensor 66 detects the magnetism of the second magnetized portion 62 via the second magnetic body 83, that is, the magnetism of the second magnetized portion 62 is guided by the second magnetic body 83. Thus, the detection accuracy of the second magnetic sensor 66 does not need to be lowered because it is guided to the second magnetic sensor 66.

  Now, such a configuration in which magnetism is guided by a magnetic material and detected by a magnetic sensor is advantageous in terms of space saving, but on the other hand, the magnetism is attenuated while passing through the magnetic material. The attenuation of the magnetism is the absolute strength of the magnetism of the measurement object (for example, the magnetism generated by the first magnetized portion 61), the length and permeability of the magnetic material guiding the magnetism, and the object to be detected (for example, Since it depends on the gap length between the first magnetized portion 61) and the magnetic body, it cannot be said unconditionally. As a result, when the detection accuracy of the magnetic sensor is insufficient, the outer side of the magnetic sensor (for example, the first magnetized portion 61) By placing a magnetic block (not shown) on the outer peripheral side of the first magnetic sensor 65 disposed on the outer peripheral side of the electromagnet 67, the output of the magnetic sensor is enhanced. This is the effect of increasing the lines of magnetic force penetrating the magnetic sensor by the magnetic block. It is also effective to use a GMR (Giant Magneto Resistive) element (giant magnetoresistive element) instead of the Hall element as the magnetic sensor. The GMR element is an element that is known to have been applied to a magnetic head of a hard disk and brought about a dramatic increase in storage capacity. This makes it possible to detect weak magnetism with high accuracy.

  The first and second magnetic bodies 81 and 83 constituting the first and second electromagnets 67 and 68 are connected via a connecting member 85. Further, the first magnetic body 81 and the permanent magnet 69 constituting the first electromagnet 67 are connected via a connecting member 86. As a result, the first magnetic sensor 65, the second magnetic sensor 66, the first electromagnet 67, the second electromagnet 68, and the permanent magnet 69 are integrated to form the position detection control unit 87. ing.

  It is preferable to use a non-magnetic material (for example, resin, ceramic, etc.) for the connecting members 85 and 86, so that the magnetic interaction between the first electromagnet 67, the second electromagnet 68 and the permanent magnet 69 is achieved. Can be prevented from occurring.

  As shown in FIG. 7, the position detection control unit 87 is arranged in a space between the magnetic rotation driving units 64 arranged at equal intervals in the circumferential direction. Here, three magnetic rotation driving units 64 are arranged at an angle of 120 degrees with respect to the center of the optical capsule 55, that is, the center of the rotating body 53 at the normal position, and the position detection control unit 87 is also optically connected. Three are arranged at an angle of 120 degrees with respect to the center of the capsule 55. As shown in FIG. 8B, this is a position detection control unit in a space formed by removing three 2-core stator cores at regular intervals from a 12-state 8-pole conventional 3-phase motor. 87 is arranged.

  As described above, the first and second magnetic sensors 65 and 66, the first and second electromagnets 67 and 68, and the permanent magnet 69 are arranged and integrated at the same position in the circumferential direction, and the magnetic rotation driving unit is integrated. Since it is arranged in the space between 64, the space outside the optical capsule 55 is effectively used to save space.

  In addition, the stator core 71 constituting the magnetic rotation driving unit 64, the first and second magnetic bodies 81 and 83 constituting the first and second electromagnets 67 and 68, and the permanent magnet 69 include the optical capsule 55. Since it is provided in contact with the outer surface, if the dimensional accuracy of the optical capsule 55 itself is managed well, the positional relationship of each component can be determined with extremely high accuracy, and high control performance is realized. be able to.

  FIG. 10 is a diagram illustrating a main part of the rotation driving device 54 illustrated in FIG. 4 and the shift control unit 14. As shown in FIG. 10, the shift control unit 14 includes a position determination unit 91 that determines the radial and axial positions of the rotating body 53 based on the output signals of the first and second magnetic sensors 65 and 66. According to the determination result of the position determination unit 91, an energization control unit 92 that controls energization amounts of the coils 82 and 84 provided in the first and second electromagnets 67 and 68 is provided. The position determination unit 91 and the energization control unit 92 are realized by executing a predetermined program by the CPU of the arithmetic processing unit 76 shown in FIG.

  The position determining unit 91 determines the radial position of the rotating body 53 based on the magnitude of the magnetism of the first magnetized unit 61 detected by the first magnetic sensor 65, and the second magnetic sensor Based on the magnitude of magnetism of the second magnetized portion 62 detected by 66, the position of the rotating body 53 in the axial direction is determined.

  The energization control unit 92 compares the actual position of the rotating body 53 acquired by the position determination unit 91 with the normal position, and corrects the correction value for correcting the deviation of the rotating body 53 with respect to the normal position in the radial direction and the axial direction. Is calculated. As shown in FIG. 9, the correction value is transmitted from the arithmetic processing unit 76 to the first and second electromagnet driving drivers 93 and 94 via the D / A converter (DAC), and corresponds to the correction value. Current to flow through the coils 82 and 84 of the first and second electromagnets 67 and 68. By such feedback control, the rotating body 53 is held at the regular radial position and axial position.

  Here, the first magnetic sensor 65 and the first electromagnet 67 are arranged at the same circumferential position, and the radial position of the rotating body 53 detected by the first magnetic sensor 65 and the first The position where the radial force is applied to the rotating body 53 by the electromagnet 67 is the same. The second magnetic sensor 66 and the second electromagnet 68 are also arranged at the same circumferential position, and the axial position of the rotating body 53 detected by the second magnetic sensor 66 and the second electromagnet. 68, the position where the axial force is applied to the rotating body 53 becomes the same. For this reason, the calculation process for position control can be simplified, and position control of the rotating body 53 can be performed easily and with high accuracy.

  In the shift control unit 14, the position determination operation by the position determination unit 91 and the position control operation by the energization control unit 92 are alternately performed in a time division manner. That is, while position control for energizing the coils 82 and 84 of the first and second electromagnets 67 and 68 is performed, position determination based on the output signals of the first and second magnetic sensors 65 and 66 is not performed. Conversely, position control is not performed while position determination is performed.

  As a result, the first and second magnetic sensors 65 and 66 are affected by the magnetic field generated by energizing the coils 82 and 84 of the first and second electromagnets 67 and 68 so that the first and second magnetic sensors 65 and 66 are magnetized. It can be avoided that the magnetism of the parts 61 and 62 cannot be detected accurately.

  By the way, in the super-resolution processing performed by the super-resolution processing unit 24 shown in FIG. 2, if the imaging position of the original frame image is known, the calculation cost of the alignment processing is greatly reduced. Can do. At this time, for example, if the image sensor 31 of 1.2 million pixels is configured with a 1/3 inch size, the pixel pitch is about 3.75 μm. The pixel pitch of the image to be obtained is 3.75 / 4 = 0.93 μm, and it is desired to grasp the imaging position with high accuracy on the order of submicrons.

  As described above, in order to grasp the imaging position of the frame image with high accuracy, it is necessary to control the position of the optical member 51 with high accuracy. This is because the first and second magnetic sensors 65, 65, 66 and first and second electromagnets 67 and 68. Furthermore, in order to grasp the imaging position of the frame image with high accuracy, it is necessary to detect with high accuracy the rotational position of the rotating body 53 that defines the light shift direction by the parallel plate 57.

  Therefore, as shown in FIG. 7, the rotation driving device 54 includes an origin sensor 70 that detects an origin position that serves as a reference for the rotational position of the optical member 51. Based on the output signal of the origin sensor 70, the shift position of the optical image when the image pickup device 31 takes an image is determined according to the timing signal generated by the drive circuit 33. Thereby, the imaging position of a frame image can be grasped with high accuracy, and the calculation cost of super-resolution processing can be reduced.

  The origin sensor 70 is composed of a reflection type photosensor (photoreflector), and detects a marking portion (not shown) provided on the support ring 52 of the optical member 51. In addition, what is necessary is just to form a marking part on the surface of the support ring 52 using the printing method etc. for the required color (for example, white if the support ring 52 is black). The origin sensor 70 is not limited to the reflection type photosensor, and a known sensor including another optical sensor can be used.

  Furthermore, in order to grasp the imaging position of the frame image with high accuracy, it is necessary to control the rotation speed of the optical member 51 with high accuracy. For this purpose, it is necessary to detect the rotational speed of the rotating body 53 with high accuracy. Here, the rotational speed of the rotating body 53 is obtained from the output signal of the first magnetic sensor 65. When the first magnetizing unit 61 rotates in conjunction with the rotating body 53, the magnetic poles (N pole and S pole) facing the first magnetic sensor 65 are alternately switched, and the signal output from the first magnetic sensor 65 is The sine wave having a period in which one pair of the N pole and the S pole of the first magnetized portion 61 is relatively moved is obtained, and the rotational speed of the rotating body 53 is obtained based on the period of the output signal. it can.

  This will be described in detail with reference to FIG. 9. The output signal of the first magnetic sensor 65 is binarized by a comparator (CMP) and output as three FG pulses, and the pulse interval of the FG pulses. Is counted by a high-speed counter (not shown). The arithmetic processing unit 76 performs an operation of dividing the known magnetic pole distance of the first magnetizing unit 61 by the count value of the high-speed counter, thereby obtaining the actually measured speed value Vn.

  In addition to such a method of detecting the rotational speed, for example, marking may be applied to the optical member 51, the first magnetized portion 61, and the like, and this may be detected by an optical sensor (photo reflector). . In this case, if the black-and-white marking is used, the rotation angular velocity can be detected at a higher sampling rate because drawing can be performed at a relatively narrow pitch.

  Further, here, PI control (proportional integral control) based on the rotation speed of the optical member 51 is performed in order to rotate the optical member 51 at a constant speed. Specifically, a speed target value Vr is set corresponding to the circular motion period instructed from the period setting unit 25 (see FIG. 2), and an error δV (= Vr) of the actually measured speed value Vn with respect to this speed target value Vr. -Vn) is calculated. Next, the proportional term (P = Gp × δV) is calculated by multiplying the error δV by an appropriate gain Gp. Further, since a speed offset occurs, the error δV is integrated, and this is multiplied by an appropriate gain Gi to calculate an integral term (I = Gi × Σ (δV)). Then, the speed command value is obtained by adding the obtained proportional term (P) and integral term (I). This speed command value is sent to the pulse width modulator (PWM) 77 as described above, and a PWM signal for operating the three-phase driver 75 is output. Thereby, the optical member 51 can be rotated at a constant speed with high accuracy.

  FIG. 11 is a cross-sectional view showing a state of incidence of light on the image sensor 31. FIG. 11A shows a state where the optical path of the incident light is shifted to the rightmost side, and FIG. A state in which the parallel plate 57 is rotated 180 ° from the state A) is shown. When the parallel plate 57 is further rotated 180 ° from the state of FIG. 11B, the state returns to the state of FIG.

  Since the parallel plate 57 of the optical member 51 is inclined with respect to the optical axis C of the lens unit 42, the position of the light that refracts the light incident through the lens unit 42 and enters the light receiving surface 31 a of the image sensor 31. Changes in accordance with the rotational position of the parallel plate 57, and when the optical member 51 is rotated by the optical shift mechanism 35, the optical image formed on the light receiving surface 31 a of the image sensor 31 becomes the rotational speed of the optical member 51. It moves so as to draw a circle with a corresponding cycle (circular motion cycle), and thereby the optical image can be relatively displaced relative to the image sensor 31.

  Thus, the parallel plate 57 has only a function of shifting the incident light that has passed through the lens unit 42 in a direction perpendicular to the optical axis C. Further, since the positional relationship between the lens unit 42 and the image sensor 31 is fixed, the angle of view on the image sensor 31 side is also determined. As is clear from these facts, the amount of optical shift remains unchanged regardless of whether the parallel plate 57 is translated in the direction of the optical axis C or in the direction perpendicular to the optical axis C. On the other hand, when the angle between the parallel plate 57 and the optical axis C changes, the optical shift amount is greatly affected. That is, what is important for the position control of the optical member 51 including the parallel flat plate 57 is the angle variation of the optical member 51 with respect to the optical axis C, and in the optical axis C direction of the optical member 51 and the direction (radial direction) perpendicular to the optical axis C. The parallel movement may be controlled so that the optical member 51 does not contact the inner wall of the optical capsule 55 as far as possible. Here, as described above, the magnetic force is applied to the optical member 51 from the external magnetic rotation driving unit 64, and this magnetic force will make the rotation center of the optical member 51 coincide with the optical axis C on average. And Therefore, among the above-described components, the first electromagnet 67 and the first magnetic sensor 65 can be omitted. However, in this case, there is a possibility that the optical member 51 may vibrate slightly, and the first electromagnet 67 and the first magnetic sensor 65 are omitted if such vibration is disliked when viewed as an imaging device. Should not.

  12 and 13 are schematic diagrams showing the state of the relative circular motion of the pixel with respect to the optical image. The imaging device 31 has a so-called Bayer array in which R pixels that receive an R (Red) component of incident light, B pixels that receive a B (Blue) component, and G pixels that receive a G (Green) component. These are so-called single-plate image sensors arranged based on the above. In this Bayer array, G pixels are arranged in a zigzag pattern (checker flag shape) with the number of pixels being 1/2 of the total number of pixels, and R pixels and B pixels are G with a number of pixels that is 1/4 of the total number of pixels. The pixels are dispersedly arranged at positions other than the pixel arrangement position. In the figure, the X axis indicates the main scanning direction, and the Y axis indicates the sub scanning direction. The same applies hereinafter.

  Here, as shown in FIG. 11, the optical image is displaced with respect to the pixels of the fixed image sensor 31, but in the following description, for the sake of convenience, the relative movement of the pixels with respect to the optical image is performed. Is illustrated such that the pixels move relative to the stationary light image. Each pixel receives light in a range generally indicated as an optical size, but in the following description, only the center position of each pixel is illustrated for convenience.

  Here, as shown in FIG. 12B, for example, when the diameter of the circular motion is set to a length of √2 times the pixel pitch, the R color information is completely missing from the movement range of the R pixel. Occurs. Similarly, an area where the B color information is completely lost is generated outside the B pixel movement range. By the way, when the diameter of the circular motion is set to a length that is √2 / 2 times the pixel pitch as in the conventional case, the area where the R color information is completely lost becomes larger, and a general Bayer array is provided. Even if a low-resolution image captured by a single-plate color image sensor is subjected to super-resolution processing, a high-definition high-resolution image cannot be reproduced.

  On the other hand, as shown in FIG. 12A, when the diameter of the circular motion is set to a length twice the pixel pitch, as shown in FIGS. 13A and 13C, the R pixel and B Since the R pixel and the B pixel can be moved to a region without pixels, the imaging position is not biased, and a high-resolution image obtained by super-resolution processing can be made high quality. Further, as shown in FIG. 13B, the G pixel originally has a large number of pixels (1/2 of the whole), and the staggered G pixel scans the peripheral region. It becomes possible to sample the image exhaustively.

  On the contrary, when the diameter of the circular motion is larger than twice the pixel pitch, a region where the R pixel and the B pixel cannot be imaged does not occur in a band shape. However, if the diameter of the circular motion is increased when the angular velocity of the circular motion is constant, the displacement speed of the optical image (that is, the peripheral speed) increases. In this case, when the same imaging period (period in which charge accumulation is performed in the imaging element 31) is given, the optical image moves by a larger distance, and the integration effect becomes large, that is, the image is blurred ( Therefore, the high-frequency component is lost due to pixel integration, and the effect of super-resolution processing is suppressed.

  Next, imaging (sampling) will be described. FIG. 14 is a schematic diagram illustrating imaging and a situation of an image generated by imaging.

  Here, imaging is performed while continuously performing relative circular movement of pixels with respect to the optical image at a constant speed in one direction, and frame images F1, F2,. The The imaging reference positions P1, P2,... Shown indicate the timing of imaging, and one frame image is generated for each. In particular, here, the center position of the pixel at the start of imaging is shown as the imaging reference position, charge accumulation is started at each imaging reference position, and charge accumulation is completed immediately before the imaging reference position, and a pixel signal is output. Is done.

  The rotational speed of this circular motion is stably maintained by the above-described PI control, the reference of the rotational position of the parallel plate 57 (see FIG. 4) is managed by the above-described origin sensor 70 (see FIG. 7), and the parallel plate 57 Since the influence on the shift width (shift position) due to the change in the tilt angle is suppressed to be small, the imaging position of the frame image captured at each timing can be grasped with extremely high accuracy.

  As shown in FIG. 2, the information regarding the imaging position is obtained by the shift control unit 14 (more specifically, the arithmetic processing unit 76 shown in FIG. 9) based on the outputs of the first magnetic sensor 65 and the origin sensor 70. Sequentially generated, transmitted from the imaging device 1 to the image processing device 2, and stored in the storage unit 23 in association with image data in units of frames output from the imaging unit 11. In the process of super-resolution processing, information regarding the imaging position is referred to by the super-resolution processing unit 24, and the alignment processing is simplified at this time.

  Note that in order to achieve an appropriate high resolution by super-resolution processing, it is desirable that all pixels be in a uniformly displaced state, and it is not appropriate to cause a time difference in charge accumulation timing between pixel lines. Here, a global shutter system is adopted in which the shutter operation of all the pixels is performed at the same timing.

  In addition, by performing many imaging (sampling) while the pixel performs one circular motion, the quality of the high resolution image obtained by the super-resolution processing can be improved. Set to a non-integer multiple of the imaging period. In this way, by repeating the circular motion, it is possible to capture images at a number of different positions, so a large number of images with slightly different imaging positions can be generated, so the high resolution obtained by super-resolution processing The image quality can be improved. On the other hand, if the circular motion cycle is an integral multiple of the imaging cycle, the imaging reference position does not change even if the circular motion is repeated, and the number of imaging reference positions that can be set by one circular motion is limited.

  Hereinafter, an example of the imaging reference position will be described by specifically determining the ratio between the circular motion period and the imaging period. FIG. 15 is a schematic diagram illustrating the state of the imaging reference position in an example of the ratio between the imaging cycle and the circular motion cycle. In FIG. 15, the pixel pitch is shown as 1.

  In this example, the circular motion cycle is set to 7.5 times the imaging cycle. Here, if the imaging cycle is 30 ms (about 30 frames / s), for example, the circular motion cycle is 225 ms (= 30 ms × 7.5). In this case, the imaging reference position returns to the original position at the second round motion, and 15 times of imaging (sampling) is performed while the circular motion is performed twice. Each imaging reference position is separated by a relative angle of 48 deg (= 360 deg / 7.5).

  In the first round movement, as shown in FIG. 15A, imaging is performed at the imaging reference positions P1 to P8. In the second round movement, as shown in FIG. 15B, the imaging reference position P9 is taken. The imaging reference positions P9 to P15 are intermediate positions between the adjacent imaging reference positions (for example, P1 and P2) in the first round motion. When the first and second circular motions are combined, the imaging reference positions P1 to P15 are separated from each other by a relative angle of 24 degrees as shown in FIG.

  Here, the first processing mode in which super-resolution processing is performed based on eight images obtained by imaging at the first imaging reference positions P1 to P8 of the circular motion, and the first and second times of the circular motion. And two processing modes, the second processing mode for performing the super-resolution processing, based on the 15 images obtained by imaging at the imaging reference positions P1 to P15.

  In the first processing mode, two imaging reference positions having different positions in both the X-axis and Y-axis directions are set within the original one pixel range, so that the image sensor in each of the X-axis and Y-axis directions. The resolution can be increased at a resolution almost twice the original resolution of 31. On the other hand, in the second processing mode, four imaging reference positions having different positions in both the X-axis and Y-axis directions are set within the original one pixel range. High resolution can be achieved with a resolution almost four times the original resolution of the image sensor 31.

  In particular, in this second processing mode, each of the imaging reference positions P9 to P15 set at the second circular motion is adjacent to the imaging reference positions P1 to P8 set at the first circular motion. Since the imaging reference position is uniformly distributed without being biased, an image excellent in compatibility with the super-resolution processing can be generated.

  It is also possible to perform super-resolution processing in the imaging device 1 while imaging is being performed in the imaging device 1. In this case, in the second processing mode, circular motion is performed twice and 15 What is necessary is just to perform a super-resolution process once whenever the image of a sheet is prepared.

  On the other hand, in the first processing mode, it is preferable to perform super-resolution processing each time eight images are aligned while sequentially shifting the imaging reference position. Specifically, super-resolution processing is performed using the eight images obtained by imaging at the imaging reference positions P1 to P8 at the first time, and at the imaging reference positions P9 to P15 and P1 at the second time. Super-resolution processing is performed using eight images obtained by imaging, and thereafter the imaging reference positions P10 to P15, P1, and P2 are set as imaging reference positions P2 to P9 for the third time and imaging reference positions P10 to P15, P1, and P2 for the fourth time. Are shifted one by one.

  In this way, two processing modes can be set. In both modes, it is not necessary to change the circular motion cycle (the rotational speed of the optical shift mechanism 35) or the imaging cycle, and thus control is easy.

  Note that the first image used for the super-resolution processing in each mode does not need to be limited to an image obtained by imaging at the imaging reference position P1, which is the original position. Super-resolution processing is performed using eight images captured during circular motions of two times. In the second processing mode, images are captured while circular motions are performed twice from an arbitrary position. Super-resolution processing may be performed using 15 images.

  Such processing is performed when super-resolution processing is performed using frame images stored in the storage unit 23 of the image processing device 2 as shown in FIG. The present invention can also be applied to the case where super-resolution processing is performed, and particularly in the latter case, it is not necessary to return the imaging start position to the imaging reference position P1 when the processing mode is switched. It is possible to generate high-resolution images with different resolutions by switching the.

  As shown in FIG. 2, the imaging cycle is designated by the user using the input unit 26 in the image processing apparatus 2, and the circular motion cycle is determined based on the designated imaging cycle by the cycle setting unit 25. A command signal related to the circular motion period determined here is transmitted to the imaging apparatus 1. The shift control unit 14 of the imaging device 1 operates the optical shift mechanism 35 at a rotational speed corresponding to the designated circular motion cycle based on the command signal regarding the circular motion cycle acquired from the image processing device 2.

  Further, the user can designate the processing mode (first processing mode and second processing mode), and uses the frame image stored in the storage unit 23 of the image processing apparatus 2 as shown in FIG. When performing super-resolution processing, the user is allowed to specify the processing mode together with the reference image, and the number of frame images corresponding to the processing mode specified here is set based on the frame image specified as the reference image. It is only necessary to read out and perform super-resolution processing.

  In addition, the said circular motion period can be changed suitably. For example, by setting the circular motion cycle to 7.2 times the imaging cycle, the imaging reference position returns to the original position at the fifth circular motion, and 36 imagings (sampling) while the circular motion is performed five times. It is also possible to adopt a configuration in which In this case, the imaging reference positions are separated by a relative angle of 50 deg (= 360 deg / 7.2).

Second Embodiment
FIG. 16 is a cross-sectional view of a main part of the rotary drive device according to the second embodiment of the present invention, and corresponds to FIG. 10 (main part of FIG. 4) of the first embodiment. Here, only points different from the first embodiment will be referred to, and the same components as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

  In this imaging device 1, as shown in FIG. 16, the support ring 52 is formed of a single ring member 52d that forms an annular shape and holds the optical member 51 on the inner peripheral side thereof. And the 1st magnetizing part 61 which comprises the rotational drive apparatus 54 is provided in the single ring member 52d so that the outer peripheral surface of radial direction may be faced, and the 2nd magnetizing part 62 is the upper end of an axial direction. The third magnetized portion 63 is provided on the single ring member 52d so as to face the lower end side in the axial direction. The first magnetized portion 61 is extremely different from the outer peripheral side of the ring member 52d at the central portion of the outer peripheral surface where a portion that is not magnetized is interposed between the second and third magnetized portions 62 and 63. Magnetized in an isotropic orientation.

  As shown in FIGS. 4 and 10, in the imaging apparatus 1 according to the first embodiment, the support ring 52 includes the first to third ring members 52a, 52b, and 52c. The second and third ring members 52b and 52c need to be bonded to the first ring member 52a. On the other hand, when the support ring 52 is configured by a single ring member 52d as in the present embodiment, it is possible to remove the concern that the ring member peels due to deterioration of the adhesive or the like, and reliability for long-term use. Can be further increased.

  Although this invention was demonstrated based on specific embodiment containing an Example, these embodiment is an illustration to the last and this invention is not limited by these embodiment. Note that all the components of the imaging apparatus according to the present invention shown in the above-described embodiments are not necessarily essential, and can be appropriately selected as long as they do not depart from the scope of the present invention.

  An image pickup apparatus according to the present invention and a network camera system including the same have the effects of ensuring long-term reliability, realizing low vibration, and further reducing the size, and controlling the axial position of a rotating body. This is useful as a rotation drive device suitable for generating a high-resolution image by super-resolution processing from a plurality of original images acquired by pixel shifting and an imaging device equipped with the same.

DESCRIPTION OF SYMBOLS 1 Imaging device 2 Image processing apparatus 11 Imaging part 13 Data compression transmission part (transmission means)
14 Shift control part 21 Data reception decoding part (reception means)
24 Super-resolution processing unit 31 Image sensor, 31a Light receiving surface 33 Drive circuit (imaging control means)
35 Optical shift mechanism 42 Lens unit 50 Optical capsule 51 Optical member 52 Support ring 52a First ring member 52b Second ring member 52c Third ring member 52d Single ring member 53 Rotating body 54 Rotating drive device 55 Optical Capsule (capsule member)
56 Liquid 57 Parallel plate 61 First magnetizing part 62 Second magnetizing part 63 Third magnetizing part 64 Magnetic rotation driving part 67 First electromagnet (first position control part)
68 Second electromagnet (second position controller)
69 Permanent magnet 82 Support ring (first ring member)
C Optical axis

Claims (5)

An image sensor that photoelectrically converts light from a subject and outputs a pixel signal;
A lens unit that focuses light from the subject on the image sensor;
An optical member inclined at a predetermined angle with respect to the optical axis of the lens unit, and a rotating body having a support ring made of a magnetic material provided on the outer peripheral side of the optical member;
A rotation drive device that relatively displaces the optical image formed on the light receiving surface of the image sensor and the image sensor by rotating the rotating body and changing the tilt direction of the optical member with respect to the optical axis. An imaging device comprising:
The rotational drive device is
A first magnetized portion provided on the support ring so as to face the outer peripheral surface of the support ring;
A second magnetized portion provided on the support ring so as to face one end surface in the axial direction of the support ring;
A third magnetized portion provided on the support ring so as to face the other end surface in the axial direction of the support ring;
A first position controller that controls a radial position of the optical member in a floating state by applying a radial magnetic force to the first magnetized portion;
A second position control unit that controls the axial position of the optical member in a floating state by applying an axial magnetic force to at least one of the second magnetized part and the third magnetized part;
A magnetic rotation drive unit that rotates the optical member by applying a magnetic force in a rotation direction to the first magnetized unit;
The imaging apparatus, wherein the first magnetized portion is magnetized in a polar anisotropic orientation so as to face an axial central portion of the outer peripheral surface of the support ring. The first magnetized portion is provided on a first ring member made of a magnetic material, the second magnetized portion is provided on a second ring member made of a magnetic material, and the third magnetized portion is Provided in a third ring member made of a magnetic material;
The imaging apparatus according to claim 1, wherein the second ring member and the third ring member are bonded to an axial end surface of the first ring member.   The imaging apparatus according to claim 1, wherein the second magnetized portion, the third magnetized portion, and the first magnetized portion are provided in a single ring member. A capsule member containing the rotating body and encapsulating a fluid having a higher refractive index than air;
The imaging apparatus according to claim 1, wherein the rotation driving device rotates the rotating body in a non-contact state with a fluid other than the fluid. A network camera system in which the imaging apparatus according to any one of claims 1 to 4 and the image processing apparatus are connected to each other via a network,
The imaging device
Shift control means for causing the rotational movement of the rotating body by the rotational drive device to be performed at a specified period;
Imaging control means for performing imaging by the imaging element at a specified cycle;
Transmission means for transmitting frame images sequentially generated by imaging with the imaging device to the image processing device;
The image processing apparatus includes:
Receiving means for receiving a frame image transmitted from the imaging device;
A network camera system comprising: super-resolution processing means for generating a high-resolution image from a plurality of frame images received by the receiving means.

Images