JP4759275B2 - Image blur correction device - Google Patents

Description

  The present invention relates to an image blur correction apparatus in an imaging apparatus, and more particularly to a position detection apparatus for a movable part such as an image sensor that has moved for image blur correction.

  Conventionally, image blurring on the image plane is suppressed by moving the image blur correction lens or image sensor on a plane perpendicular to the optical axis in accordance with the amount of camera shake that occurs during imaging in an imaging device such as a camera. An image blur correction device has been proposed.

Patent Document 1 discloses a device in which a movable part including an image blur correction lens is moved by a permanent magnet and a coil, and position detection before and after the movement is performed by a Hall element and a permanent magnet.
JP 2002-229090 A

  However, in the device of Patent Document 1, the permanent magnet, the Hall element, and the yoke for position detection are attached to the end portions of the movable portion and the fixed portion. For this reason, when rattling occurs due to the clearance of the mechanism portion related to driving, the amount of movement of the image blur correction lens in the movable portion and the member for detecting the position in the movable portion (Hall element in Patent Document 1) The amount of movement may vary.

  Accordingly, an object of the present invention is to provide an apparatus capable of accurately detecting a position even if a mechanical part is shaken in an image blur correction apparatus.

  An image blur correction device for an image pickup apparatus according to the present invention detects an image pickup element, a first direction orthogonal to the optical axis of the photographing lens with respect to the image pickup element, and a position in a second direction orthogonal to the optical axis and the first direction. A position detecting magnet that is used to move the movable portion in the first and second directions, and a magnetic field change detecting portion that is used to detect the position at a position facing the position detecting magnet. The magnetic field change detection unit includes first and second horizontal magnetic field change detection elements used for position detection in the first direction and first and second verticals used for position detection in the second direction. When the position of the center of the image sensor passes through the optical axis due to the movement of the movable part, the optical axis is in the vicinity of the center of the surface facing the magnetic field change detection part of the position detection magnet. Pass through. As a result, even if the mechanical shake of the image blur correction apparatus occurs, the movement amount of the image pickup element in the movable portion and the movement amount of the position detection member, that is, the position detection magnet in the movable portion are substantially the same. By doing so, accurate position detection becomes possible.

  Preferably, when the vicinity of the center of the image sensor passes through the optical axis due to the movement of the movable part, the movable part is positioned at the center of the movement range in both the first and second directions. As a result, it is possible to perform image blur correction by making maximum use of the imaging range of the image sensor.

  More preferably, the surface of the position detection magnet facing the magnetic field change detection unit is a square formed by a line parallel to one of the first and second directions, and the position detection magnet is parallel to the optical axis. When the N pole and the S pole are arranged in the third direction and the vicinity of the center of the image sensor passes through the optical axis due to the movement of the movable part, the second direction of the first and second horizontal magnetic field change detection elements Each of the positions of the first and second vertical direction magnetic field change detecting elements faces the vicinity of the middle of the second direction of the square, and the positions of the first direction face the vicinity of both ends of the first direction of the square, respectively. Each of the positions in the first direction faces the vicinity of the middle of the square in the first direction, and each of the positions in the second direction faces the vicinity of both ends of the square in the second direction. As a result, position detection can be performed by making maximum use of the square size of the position detection magnet.

  Preferably, the movable part has a plate at a position in contact with the position detection magnet and the image sensor and sandwiched between the position detection magnet and the image sensor, and the plate is made of a metal material. . As a result, it is possible to dissipate heat from the image sensor using the surface area of the position detection magnet in addition to the plate.

  More preferably, the position detection magnet is a permanent magnet, and the plate is a magnetic material that is attracted by a magnetic force from the position detection magnet. Thereby, attachment of a plate and the magnet for position detection can be simplified by magnetic force.

  Preferably, the fixed portion has a position detecting yoke made of a magnetic material on the back side of the magnetic field change detecting portion facing the position detecting magnet. Thereby, the magnetic flux density between the position detection magnet and the magnetic field change detection element can be increased.

  Preferably, the first and second horizontal magnetic field change detection elements and the first and second vertical magnetic field change detection elements are any one of a Hall element, an MI sensor, a magnetic resonance magnetic field detection element, and an MR element. is there.

  Preferably, the magnetic field change detection unit is a biaxial Hall element, and the first and second horizontal magnetic field change detection elements and the first and second vertical magnetic field change detection elements are all Hall elements.

  As described above, according to the present invention, it is possible to provide an apparatus capable of accurate position detection even when the mechanical shake of the image blur correction apparatus occurs.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The imaging device 1 will be described as a digital camera. In order to describe the direction, in the imaging device 1, the horizontal direction orthogonal to the optical axis LX is the first direction x, the vertical direction orthogonal to the optical axis LX is the second direction y, and the horizontal direction parallel to the optical axis LX is The third direction z will be described. FIG. 5 shows a configuration diagram in a cross section taken along line AA of FIG. In FIG. 4, the sensor substrate 66b and the position detection yoke 43b are not shown.

  The parts related to the imaging of the imaging device 1 are the Pon button 11 for switching on / off the main power source, the release button 13, the LCD monitor 17, the CPU 21, the imaging block 22, the AE unit 23, the AF unit 24, and the imaging unit of the image blur correction device 30. 39a and a photographing lens 67. In response to pressing of the Pon button 11, the on / off state of the Pon switch 11 a is switched. The subject image is captured as an optical image through the photographing lens 67 by the imaging block 22 that drives the imaging unit 39a, and the image captured by the LCD monitor 17 is displayed. The subject image can also be optically observed with an optical viewfinder (not shown).

  When the release button 13 is half-pressed, the photometry switch 12a is turned on to perform photometry, distance measurement, and focusing operation. When the release button 13 is fully pressed, the release switch 13a is turned on to take an image. Is stored in memory.

  The imaging block 22 drives the imaging unit 39a. The AE unit 23 performs a photometric operation of the subject to calculate an exposure value, and calculates an aperture value and an exposure time necessary for photographing based on the exposure value. The AF unit 24 performs distance measurement, and performs focus adjustment by displacing the photographing lens 67 in the optical axis direction based on the distance measurement result.

  The portion relating to image blur correction of the image pickup apparatus 1 includes an image blur correction button 14, a CPU 21, an angular velocity detection unit 25, a driver circuit 29, an image blur correction device 30, a Hall element signal processing circuit 45, and a photographing lens 67.

  When the image blur correction button 14 is pressed, the image blur correction switch 14a is turned on, and the angular velocity detection unit 25 and the image blur correction device 30 are driven at regular intervals independently of other operations such as photometry. Then, image blur correction is performed. The parameter IS = 1 is set in the correction mode in which the image blur correction switch 14a is turned on, and the parameter IS = 0 is set in the correction mode in which the image blur correction switch 14a is not turned off. In the present embodiment, this fixed time will be described as 1 ms.

  Various outputs corresponding to the input signals of these switches are controlled by the CPU 21. On / off information of the photometry switch 12a, release switch 13a, and image blur correction switch 14a is input to the ports P12, P13, and P14 of the CPU 21 as 1-bit digital signals, respectively. The imaging block 22, the AE unit 23, and the AF unit 24 input and output signals at ports P3, P4, and P5, respectively.

  Next, details of the angular velocity detection unit 25, the driver circuit 29, the image blur correction device 30, the Hall element signal processing circuit 45, and an input / output relationship with the CPU 21 will be described.

  The angular velocity detection unit 25 includes first and second angular velocity sensors 26 and 27 and an amplifier / high pass filter circuit 28. The first and second angular velocity sensors 26 and 27 detect angular velocities in the first direction x and the second direction y every fixed time (1 ms) of the imaging device 1. The first angular velocity sensor 26 detects the angular velocity in the first direction x, and the second angular velocity sensor 27 detects the angular velocity in the second direction y. The amplifier / high-pass filter circuit 28 amplifies the signal related to the angular velocity, cuts the null voltage and panning of the first and second angular velocity sensors 26 and 27, and outputs an analog signal as the first and second angular velocities vx and vy of the CPU 21. Input to A / D0 and A / D1.

  The CPU 21 performs A / D conversion on the first and second angular velocities vx and vy input to A / D0 and A / D1, and then performs image blurring that occurs in a certain time (1 ms) by a conversion coefficient that takes into account the focal length and the like. Calculate the quantity. Therefore, the angular velocity detection unit 25 and the CPU 21 have an image blur amount calculation function.

  The CPU 21 calculates the position S to be moved of the imaging unit 39a according to the image blur amount obtained by the calculation for each of the first direction x and the second direction y. The first direction x component of the position S is sx, and the second direction y component is sy. Movement of the movable part 30a including the imaging part 39a is performed by an electromagnetic force described later. In order to move the movable part 30a to this position S, the first direction x component of the driving force D that drives the driver circuit 29 is defined as a first PWM duty dx, and the second direction y component is defined as a second PWM duty dy.

  The image blur correction device 30 moves the imaging unit 39a to the position S to be moved calculated by the CPU 21, thereby eliminating the shift of the optical axis LX on the imaging plane of the subject image caused by the blur and imaging with the subject image. This is a device that keeps the surface position constant and corrects image blur, and includes a movable part 30a including an imaging part 39a and a movable area, and a fixed part 30b. In addition, the image blur correction device 30 includes a driving part that moves the movable part 30a by an electromagnetic force generated by the direction of the current flowing through the coil and the direction of the magnetic field of the magnet, and a position detection part that detects the position of the movable part 30a. It can be divided into two categories.

  The movable portion 30a of the image blur correction device 30 is driven by a driver circuit 29 that receives the output of the first PWM duty dx from the PWM0 and the second PWM duty dy from the PWM1 of the CPU 21. The position P before or after the movement of the movable part 30a moved by driving the driver circuit 29 is detected by the hall element part 44b and the hall element signal processing circuit 45. Information on the detected position P is input to the A / D2 and A / D3 of the CPU 21 with the first detection position signal px as the first direction x component and the second detection position signal py as the second direction y component. . The first and second detection position signals px and py are A / D converted via A / D2 and A / D3. The first direction x component and the second direction y component of the position P after A / D conversion with respect to the first and second detection position signals px and py are set to pdx and pdy, respectively. PID control is performed based on the data of the detected position P (pdx, pdy) and the data of the position S (sx, sy) to be moved.

  The movable portion 30a includes first and second driving coils 31a and 32a, an imaging portion 39a, a position detecting magnet 41a, a movable substrate 49a, a moving shaft 50a, first to third horizontal moving bearing portions 51a to 53a, Plate 64a.

  A member that requires electrical wiring in the movable portion 30a needs to be supplied with electric power from the fixed portion 30b and other portions by a flexible substrate or the like. However, when the position detection magnet 41a is a permanent magnet, the position detection part in the movable part 30a does not require electric power, and therefore, the wiring is simplified because the electric part to the position detection part is not required in the movable part 30a. As a result, reduction of the external force to the movable part 30a is implement | achieved.

  The fixed portion 30b includes first and second driving permanent magnets 33b and 34b, first and second driving yokes 35b and 36b, a position detecting yoke 43b, a hall element portion 44b, and first to fourth vertical movement bearings. Portions 54b to 57b, a base plate 65b, and a sensor substrate 66b.

  The U-shaped moving shaft 50a viewed from the third direction z of the movable portion 30a is perpendicular to the first to fourth vertical moving bearing portions 54b to 57b attached to the base plate 65b of the fixed portion 30b. It is supported so as to be movable in the (second direction y). The first and second vertical movement bearing portions 54b and 55b have a long hole shape extending in the second direction y when viewed from the first direction x. Thereby, the movable part 30a can move in the vertical direction with respect to the fixed part 30b.

  The moving shaft 50a is supported so as to be movable in the horizontal direction (first direction x) with the first to third horizontal moving bearing portions 51a to 53a of the movable portion 30a. Thereby, the movable part 30a excluding the moving shaft 50a can move in the horizontal direction with respect to the moving shaft 50a and the fixed part 30b.

  In order to make maximum use of the imaging range of the image sensor 39a1, when the vicinity of the center of the image sensor 39a1 is in a positional relationship passing through the optical axis LX of the photographic lens 67, the movable portion 30a is in both the first direction x and the second direction y The positional relationship between the movable part 30a and the fixed part 30b is set so as to be located at the center of the movement range (at the movement center position). The center of the image sensor 39a1 refers to the intersection of two diagonal lines of a rectangle that forms the imaging surface of the image sensor 39a1.

  The movable unit 30a is attached with an imaging unit 39a, a plate 64a, a movable substrate 49a, and a position detecting magnet 41a in the optical axis direction when viewed from the direction of the photographing lens 67. The imaging unit 39a includes an imaging element 39a1, a stage 39a2, a pressing unit 39a3, and an optical low-pass filter 39a4. The stage 39a2 and the plate 64a sandwich and urge the imaging element 39a1, the pressing unit 39a3, and the optical low-pass filter 39a4. The first to third horizontal movement bearing portions 51a to 53a are attached to the stage 39a2. The plate 64 a is positioned so that the image sensor 39 a 1 is perpendicular to the optical axis LX of the photographic lens 67 when the image sensor 39 a 1 is attached. Further, when the plate 64a is made of a metal material, the plate 64a is further brought into a heat radiation effect by being in contact with the image sensor 39a1.

  The movable substrate 49a is attached with first and second driving coils 31a and 32a and a position detecting magnet 41a on which a sheet-like spiral coil pattern is formed. The first driving coil 31a moves the movable portion 30a including the first driving coil 31a in the first direction by an electromagnetic force generated from the direction of the current of the first driving coil 31a and the direction of the magnetic field of the first driving permanent magnet 33b. In order to move to x, it has a coil pattern formed by a line parallel to either the first direction x or the second direction y. The second drive coil 32a moves the movable part 30a including the second drive coil 32a in the second direction by electromagnetic force generated from the direction of the current of the second drive coil 32a and the direction of the magnetic field of the second drive permanent magnet 34b. In order to move to y, it has a coil pattern formed by a line parallel to either the first direction x or the second direction y.

  The first and second driving coils 31a and 32a are connected to a driver circuit 29 for driving them via a flexible substrate (not shown). The driver circuit 29 receives the first and second PWM duties dx and dy from the PWM0 and PWM1 of the CPU 21, respectively. The driver circuit 29 supplies power to the first and second drive coils 31a and 32a in accordance with the input first and second PWM duties dx and dy, and drives the movable portion 30a.

  The position detection magnet 41a is attached with the N pole and the S pole arranged in the third direction z. The surface of the position detection magnet 41a facing the fixed portion 30b is a square formed by a line parallel to either the first direction x or the second direction y. Since the shape of the surface of the position detection magnet 41a facing the fixed portion 30b is square, when the movable portion 30a is moved in the second direction y, the position detection in the first direction x is not affected, and the first When moved in one direction x, the position detection in the second direction y is not affected.

  When the movable part 30a is at the movement center position, the position detection magnet 41a is attached so that the optical axis LX of the photographing lens 67 passes through the vicinity of the center of the square. For this reason, even if rattling occurs due to the clearance of the mechanism unit, the amount of movement of the imaging element in the movable unit 30a and the amount of movement of the position detection member in the movable unit 30a, that is, the position detection magnet 41a, are Can be almost the same.

  The position detecting magnet 41a is attached so as to be in contact with the plate 64a. When the position detection magnet 41a is a permanent magnet, the permanent magnet contacts the plate 64a. When the position detection magnet 41a is an electromagnet, the magnetic material constituting the magnetic core of the electromagnet is in contact with the plate 64a. That is, there is a positional relationship in which the plate 64a is sandwiched between the position detection magnet 41a and the image sensor 39a1. For this reason, when the plate 64a is made of a metal material, the heat generated by the imaging element 39a1 can be radiated by the magnetic material constituting the permanent magnet of the position detection magnet 41a or the magnetic core of the electromagnet together with the plate 64a. Become. At this time, since the surface area capable of radiating heat is increased by the position detecting magnet 41a, the heat radiation effect is also improved.

  Further, when the position detection magnet 41a is a permanent magnet and the plate 64a is a magnetic material that is attracted by the magnetic force of the position detection magnet 41a, such as iron or nickel, the plate 64a of the position detection magnet 41a. Attachment to the can be simplified by magnetic force.

  In addition, with one magnet, position detection in the first direction x using the first and second horizontal hall elements hh1 and hh2, and second direction y using the first and second vertical hall elements hv1 and hv2. It becomes possible to perform position detection. Therefore, a small magnet can be used for both driving and position detection. Similarly, the drive and position detection yokes can be reduced in size. Therefore, the driving coil can be arranged in the empty space of the movable portion, and the driving magnet can be arranged in the empty space of the fixed portion, and the entire image blur correction apparatus can be downsized.

  The first and second drive permanent magnets 33b and 34b are attached to the movable portion 30a side of the fixed portion 30b so as to face the first and second drive coils 31a and 32a, respectively. The hall element portion 44b is attached to the movable portion 30a side of the fixed portion 30b so as to face the position detection magnet 41a. The position detection yoke 43b is attached to the opposite side of the surface of the fixed portion 30b where the hall element portion 44b is located, that is, the back side of the hall element portion 44b facing the position detection permanent magnet 41a. The position detecting yoke 43b is made of a magnetic material and serves to increase the magnetic flux density between the position detecting magnet 41a and the Hall element portion 44b.

  The first driving permanent magnet 33b is on the base plate 65b of the fixed portion 30b in the third direction z and on the first driving yoke 35b attached to the movable portion 30a side, and N in the first direction x. The pole and the S pole are mounted side by side. The length of the first driving permanent magnet 33b in the second direction y is such that the magnetic field exerted on the first driving coil 31a does not change when the movable part 30a moves in the second direction y. Is set longer than the first effective length L1 in the second direction y.

  The second driving permanent magnet 34b is on the base plate 65b of the fixed portion 30b in the third direction z and on the second driving yoke 36b attached to the movable portion 30a, and is N in the second direction y. The pole and the S pole are mounted side by side. The length of the second driving permanent magnet 34b in the first direction x is such that the magnetic field exerted on the second driving coil 32a does not change when the movable part 30a moves in the first direction x. Is set to be longer than the second effective length L2 in the first direction x.

  The first drive yoke 35b is made of a polygonal soft magnetic material having a U-shape when viewed in the second direction y, and the first drive permanent magnet 33b and the first drive coil 31a are connected to the third. It is attached on the base plate 65b of the fixed portion 30b so as to be sandwiched in the direction z. The portion of the first driving yoke 35b on the side in contact with the first driving permanent magnet 33b serves to prevent the magnetic field of the first driving permanent magnet 33b from leaking to the surroundings. The first driving permanent magnet 33b, the first driving coil 31a, and the portion facing the movable substrate 49a in the first driving yoke 35b are between the first driving permanent magnet 33b and the first driving coil 31a. It serves to increase the magnetic flux density.

  The second drive yoke 36b is made of a polygonal soft magnetic material having a U-shape when viewed in the first direction x, and the second drive permanent magnet 34b and the second drive coil 32a are connected to the third direction. It is attached on the base plate 65b of the fixed portion 30b so as to be sandwiched in the direction z. The portion of the second drive yoke 36b on the side in contact with the second drive permanent magnet 34b serves to prevent the magnetic field of the second drive permanent magnet 34b from leaking out. The second drive permanent magnet 34b, the second drive coil 32a, and the portion of the second drive yoke 36b facing the movable substrate 49a are between the second drive permanent magnet 34b and the second drive coil 32a. It serves to increase the magnetic flux density.

  The Hall element portion 44b is a biaxial Hall element in which four Hall elements, which are magnetoelectric conversion elements (magnetic field change detection elements) utilizing the Hall effect, are arranged. The Hall element portion 44b has a first direction x and a second direction y of the movable portion 30a. First and second detection position signals px and py for identifying the current position P are detected. Of the four hall elements, the first and second horizontal hall elements hh1 and hh2 are used for position detection in the first direction x, and the first and second vertical hall elements are used for position detection in the second direction y. Hall elements hv1 and hv2 are used.

  Since the first and second horizontal hall elements hh1 and hh2 detect the position of the movable portion 30a in the first direction x, their input terminals (not shown) are wired in series. The first and second horizontal hall elements hh1 and hh2 are mounted on the sensor substrate 66b of the fixed portion 30b as viewed from the third direction z and at positions facing the position detecting magnet 41a of the movable portion 30a.

  The position of the first and second horizontal hall elements hh1 and hh2 in the second direction y is determined by the imaging element so that the position detection can be performed by making maximum use of the square size of the position detection magnet 41a. When the vicinity of the center of 39a1 is in a positional relationship passing through the optical axis LX, all of them are located in the vicinity of the middle in the second direction y of the square of the surface facing the Hall element portion 44b of the position detecting magnet 41a. desirable. The positions of the first and second horizontal hall elements hh1 and hh2 in the first direction x are the hall element portions 44b of the position detecting magnet 41a when the vicinity of the center of the image sensor 39a1 passes through the optical axis LX. It is desirable that it is in a place facing both ends in the first direction x of the square of the surface facing to (see FIG. 9).

  Since the first and second vertical hall elements hv1 and hv2 detect displacement of the movable portion 30a in the second direction y, respective input terminals (not shown) are wired in series. The first and second vertical hall elements hv1 and hv2 are mounted on the sensor substrate 66b of the fixed portion 30b as viewed from the third direction z and at positions facing the position detecting magnet 41a of the movable portion 30a.

  The position of the first and second vertical hall elements hv1 and hv2 in the first direction x is determined so that the position detection can be performed by making maximum use of the square size of the position detection magnet 41a. When the vicinity of the center of 39a1 is in a positional relationship passing through the optical axis LX, all of them are located in the vicinity of the middle in the first direction x of the square of the surface facing the hall element portion 44b of the position detecting magnet 41a. desirable. The positions of the first and second vertical hall elements hv1 and hv2 in the second direction y are the hall element portions 44b of the position detecting magnet 41a when the vicinity of the center of the imaging element 39a1 passes through the optical axis LX. It is desirable to be in a place facing both ends of the square in the second direction y of the square facing the surface.

  The base plate 65b and the sensor substrate 66b are plate-like members that serve as a base to which the hall element portion 44b and the like are attached in the fixed portion 30b, and are arranged in parallel with the imaging surface of the imaging device 39a1. The sensor substrate 66b is in a positional relationship such that the position detection magnet 41a is sandwiched between the image sensor 39a1. In the present embodiment, the base plate 65b is closer to the photographing lens 67 than the movable substrate 49a in the third direction z, but the positional relationship is such that the movable substrate 49a is closer to the photographing lens 67. There may be. In this case, the first and second drive coils 31a and 32a are on the opposite side of the movable substrate 49a from the side where the photographic lens 67 is located, and the first and second drive permanent magnets 33b and 34b are photographic lenses 67 on the base plate 65b. Placed on the side where there is.

  The Hall element signal processing circuit 45 calculates the first and second horizontal potential differences between the output terminals of the first and second horizontal Hall elements hh1 and hh2 from the output signals of the first and second horizontal Hall elements hh1 and hh2. x1 and x2 are detected, and from these, a first detection position signal px for specifying the position in the first direction x is output to A / D2 of the CPU 21. In addition, the Hall element signal processing circuit 45 generates first and second vertical signals between the output terminals of the first and second vertical Hall elements hv1 and hv2 from the output signals of the first and second vertical Hall elements hv1 and hv2. The direction potential differences y1 and y2 are detected, and a second detection position signal py for specifying the position in the second direction y is output from these to the A / D3 of the CPU 21.

  A circuit configuration relating to input / output signals of the first and second horizontal hall elements hh1 and hh2 in the hall element signal processing circuit 45 will be described with reference to FIG. A circuit configuration relating to input / output signals of the first and second vertical Hall elements hv1 and hv2 in the Hall element signal processing circuit 45 will be described with reference to FIG. For simplification of description, the circuit configuration relating to the first and second vertical hall elements hv1, hv2 is omitted in FIG. 6, and the circuit configuration relating to the first and second horizontal hall elements hh1, hh2 is omitted in FIG. Omitted.

  In the Hall element signal processing circuit 45, the output portions of the first and second horizontal Hall elements hh1 and hh2 have first to fifth circuits 451 to 455, and the input portion has a sixth circuit 456. In the Hall element signal processing circuit 45, the output units of the first and second vertical Hall elements hv 1 and hv 2 have 11th to 15th circuits 461 to 465, and the input unit has a 16th circuit 466.

  Each of the output terminals of the first horizontal hall element hh1 is connected to the first circuit 451, and the first circuit 451 is connected to the third circuit 453. Each of the output terminals of the second horizontal hall element hh2 is connected to the second circuit 452, and the second circuit 452 is connected to the fourth circuit 454. The third and fourth circuits 453 and 454 are connected to the fifth circuit 455. The first and second circuits 451 and 452 are differential amplifier circuits that amplify signal differences between the output terminals of the first and second horizontal hall elements hh1 and hh2, respectively. The third circuit 453 is a subtraction circuit that obtains the first horizontal potential difference x1 between the output terminals of the first horizontal hall element hh1 from the difference between the amplified signal difference and the reference voltage Vref. The fourth circuit 454 is a subtraction circuit that obtains the second horizontal potential difference x2 between the output terminals of the second horizontal hall element hh2 from the difference between the amplified signal difference and the reference voltage Vref. The fifth circuit 455 is a subtraction amplification circuit that obtains the first detection position signal px by multiplying the difference between the first and second horizontal potential differences x1 and x2 by a constant amplification factor.

  The first circuit 451 includes first to third resistors R1 to R3, first and second operational amplifiers A1 and A2. One of the output terminals of the first horizontal hall element hh1 is connected to the non-inverting input terminal of the first operational amplifier A1, and the other terminal is connected to the non-inverting input terminal of the second operational amplifier A2. The inverting input terminal of the first operational amplifier A1 is connected to the first and second resistors R1 and R2, and the inverting input terminal of the second operational amplifier A2 is connected to the first and third resistors R1 and R3. The output terminal of the first operational amplifier A1 is connected to the second resistor R2 and the seventh resistor R7 of the third circuit 453. The output terminal of the second operational amplifier A2 is connected to the third resistor R3 and the ninth resistor R9 of the third circuit 453.

  The second circuit 452 includes fourth to sixth resistors R4 to R6, and third and fourth operational amplifiers A3 and A4. One of the output terminals of the second horizontal hall element hh2 is connected to the non-inverting input terminal of the third operational amplifier A3, and the other terminal is connected to the non-inverting input terminal of the fourth operational amplifier A4. The inverting input terminal of the third operational amplifier A3 is connected to the fourth and fifth resistors R4 and R5, and the inverting input terminal of the fourth operational amplifier A4 is connected to the fourth and sixth resistors R4 and R6. The output terminal of the third operational amplifier A3 is connected to the fifth resistor R5 and the eleventh resistor R11 of the fourth circuit 454. The output terminal of the fourth operational amplifier A4 is connected to the sixth resistor R6 and the thirteenth resistor R13 of the fourth circuit 454.

  The third circuit 453 includes seventh to tenth resistors R7 to R10 and a fifth operational amplifier A5. The inverting input terminal of the fifth operational amplifier A5 is connected to the seventh resistor R7 and the eighth resistor R8, the non-inverting input terminal is connected to the ninth resistor R9 and the tenth resistor R10, and the output terminal is the eighth resistor R8 and the fifth resistor R8. Connected to the fifteenth resistor R15 of the circuit 455, the first horizontal potential difference x1 is output. One terminal of the tenth resistor R10 is connected to the power source of the reference voltage Vref.

  The fourth circuit 454 includes first to fourteenth resistors R11 to R14 and a sixth operational amplifier A6. The inverting input terminal of the sixth operational amplifier A6 is connected to the eleventh resistor R11 and the twelfth resistor R12, the non-inverting input terminal is connected to the thirteenth resistor R13 and the fourteenth resistor R14, and the output terminal is the twelfth resistor R12 and the fifth resistor. Connected to the seventeenth resistor R17 of the circuit 455, the second horizontal potential difference x2 is output. One terminal of the fourteenth resistor R14 is connected to the power source of the reference voltage Vref.

  The fifth circuit 455 includes fifteenth to eighteenth resistors R15 to R18 and a seventh operational amplifier A7. The inverting input terminal of the seventh operational amplifier A7 is connected to the fifteenth resistor R15 and the sixteenth resistor R16, the non-inverting input terminal is connected to the seventeenth resistor R17 and the eighteenth resistor R18, and the output terminal is connected to the sixteenth resistor R16. A first detection position signal px obtained by multiplying the difference between the first and second horizontal potential differences x1 and x2 by a constant amplification factor is output. One terminal of the eighteenth resistor R18 is connected to the power source of the reference voltage Vref.

  The first and fourth resistors R1 and R4 have the same resistance value, the second, third, fifth, and sixth resistors R2, R3, R5, and R6 have the same resistance value, and the seventh to fourteenth resistors R7 to R14 have the same resistance value. The fifteenth and seventeenth resistors R15 and R17 are set to the same resistance value, and the sixteenth and eighteenth resistors R16 and R18 are set to the same resistance value. The first to fourth operational amplifiers A1 to A4 are set to the same operational amplifier, and the fifth and sixth operational amplifiers A5 and A6 are set to the same operational amplifier.

  The sixth circuit 456 includes a nineteenth resistor R19 and an eighth operational amplifier A8. The inverting input terminal of the eighth operational amplifier A8 is connected to one of the nineteenth resistor R19 and the input terminal of the second horizontal hall element hh2. The potential of the non-inverting input terminal of the eighth operational amplifier A8 is set to a constant voltage Vfx corresponding to a constant current value in the first and second horizontal hall elements hh1 and hh2. The output terminal of the eighth operational amplifier A8 is connected to one input terminal of the first horizontal hall element hh1. One terminal of the nineteenth resistor R19 is grounded.

  Each of the output terminals of the first vertical hall element hv1 is connected to the eleventh circuit 461, and the eleventh circuit 461 is connected to the thirteenth circuit 463. Each of the output terminals of the second vertical hall element hv2 is connected to the twelfth circuit 462, and the twelfth circuit 462 is connected to the fourteenth circuit 464. The thirteenth and fourteenth circuits 463 and 464 are connected to the fifteenth circuit 465. The eleventh and twelfth circuits 461 and 462 are differential amplifier circuits that amplify the signal difference between the output terminals of the first and second vertical Hall elements hv1 and hv2, respectively. The thirteenth circuit 463 is a subtraction circuit that obtains the first vertical potential difference y1 between the output terminals of the first vertical hall element hv1 from the difference between the amplified signal difference and the reference voltage Vref. The fourteenth circuit 464 is a subtraction circuit that obtains the second vertical potential difference y2 between the output terminals of the second vertical hall element hv2 from the difference between the amplified signal difference and the reference voltage Vref. The fifteenth circuit 465 is a subtracting amplifier circuit that obtains the second detection position signal py by multiplying the difference between the first and second vertical potential differences y1 and y2 by a constant amplification factor.

  The eleventh circuit 461 includes 21st to 23rd resistors R21 to R23, 21st and 22nd operational amplifiers A21 and A22. One output terminal of the first vertical hall element hv1 is connected to the non-inverting input terminal of the twenty-first operational amplifier A21, and the other terminal is connected to the non-inverting input terminal of the twenty-second operational amplifier A22. The inverting input terminal of the twenty-first operational amplifier A21 is connected to the twenty-first and twenty-second resistors R21 and R22, and the inverting input terminal of the twenty-second operational amplifier A22 is connected to the twenty-first and twenty-third resistors R21 and R23. The output terminal of the twenty-first operational amplifier A21 is connected to the twenty-second resistor R22 and the twenty-seventh resistor R27 of the thirteenth circuit 463. The output terminal of the 22nd operational amplifier A22 is connected to the 23rd resistor R23 and the 29th resistor R29 of the 13th circuit 463.

  The twelfth circuit 462 includes twenty-fourth to twenty-sixth resistors R24 to R26, a twenty-third and twenty-fourth operational amplifiers A23 and A24. One of the output terminals of the second vertical hall element hv2 is connected to the non-inverting input terminal of the 23rd operational amplifier A23, and the other terminal is connected to the non-inverting input terminal of the 24th operational amplifier A24. The inverting input terminal of the 23rd operational amplifier A23 is connected to the 24th and 25th resistors R24 and R25, and the inverting input terminal of the 24th operational amplifier A24 is connected to the 24th and 26th resistors R24 and R26. The output terminal of the 23rd operational amplifier A23 is connected to the 25th resistor R25 and the 31st resistor R31 of the 14th circuit 464. The output terminal of the 24th operational amplifier A24 is connected to the 26th resistor R26 and the 33rd resistor R33 of the 14th circuit 464.

  The thirteenth circuit 463 includes 27th to 30th resistors R27 to R30 and a 25th operational amplifier A25. The inverting input terminal of the 25th operational amplifier A25 is connected to the 27th resistor R27 and the 28th resistor R28, the non-inverting input terminal is connected to the 29th resistor R29 and the 30th resistor R30, and the output terminal is the 28th resistor R28 and the 15th resistor. Connected to the 35th resistor R35 of the circuit 465, the first vertical potential difference y1 is output. One terminal of the thirtieth resistor R30 is connected to the power source of the reference voltage Vref.

  The fourteenth circuit 464 includes 31st to 34th resistors R31 to R34 and a 26th operational amplifier A26. The inverting input terminal of the 26th operational amplifier A26 is connected to the 31st resistor R31 and the 32nd resistor R32, the non-inverting input terminal is connected to the 33rd resistor R33 and the 34th resistor R34, and the output terminal is the 32nd resistor R32 and the 15th resistor. Connected to the 37th resistor R37 of the circuit 465, the second vertical potential difference y2 is output. One terminal of the 34th resistor R34 is connected to the power supply of the reference voltage Vref.

  The fifteenth circuit 465 includes 35th to 38th resistors R35 to R38 and a 27th operational amplifier A27. The inverting input terminal of the 27th operational amplifier A27 is connected to the 35th resistor R35 and the 36th resistor R36, the non-inverting input terminal is connected to the 37th resistor R37 and the 38th resistor R38, and the output terminal is connected to the 36th resistor R36. The second detection position signal py obtained by multiplying the difference between the first and second vertical potential differences y1 and y2 by a constant amplification factor is output. One terminal of the thirty-eighth resistor R38 is connected to the power source of the reference voltage Vref.

  The twenty-first and twenty-fourth resistors R21 and R24 have the same resistance value, the twenty-second, twenty-third, twenty-fifth and twenty-sixth resistors R22, R23, R25 and R26 have the same resistance value, and the twenty-seventh to thirty-fourth resistors R27 to R34 have the same resistance value. The 35th and 37th resistors R35 and R37 are set to the same resistance value, and the 36th and 38th resistors R36 and R38 are set to the same resistance value. The 21st to 24th operational amplifiers A21 to A24 are set to the same operational amplifier, and the 25th and 26th operational amplifiers A25 and A26 are set to the same operational amplifier.

  The sixteenth circuit 466 includes a 39th resistor R39 and a 28th operational amplifier A28. The inverting input terminal of the 28th operational amplifier A28 is connected to one of the 39th resistor R39 and the input terminal of the second vertical hall element hv2. The potential of the non-inverting input terminal of the 28th operational amplifier A28 is set to a constant voltage Vfy corresponding to the constant current value in the first and second vertical Hall elements hv1 and hv2. The output terminal of the 28th operational amplifier A28 is connected to one of the input terminals of the first vertical hall element hv1. One terminal of the 39th resistor R39 is grounded.

  Next, the procedure of image blur correction processing that is performed independently of other operations as interrupt processing at regular time intervals (1 ms) will be described with reference to the flowchart of FIG.

  When the image blur correction process interrupt operation starts in step S11, the first and second angular velocities vx and vy output from the angular velocity detection unit 25 in step S12 are converted to A via the A / D0 and A / D1 of the CPU 21, respectively. / D converted and input. In step S13, the first and second detected position signals px and py of the movable portion 30a, which are detected by the Hall element portion 44b and calculated by the Hall element signal processing circuit 45, are obtained from the A / D2 and A / D3 of the CPU 21, respectively. Through A / D conversion. Thus, the current position P (pdx, pdy) is obtained.

  In step S14, it is determined whether IS = 0. When IS = 0, that is, when the correction mode is not set, in step S15, the position S (sx, sy) to which the movable part 30a should move is made the same as the movement center position of the movable part 30a. In the case of IS = 1, that is, in the correction mode, in step S16, the position S (sx, sy) to which the movable part 30a should move is calculated from the first and second angular velocities vx, vy obtained in step S12.

  In step S17, the driving force D required for movement of the movable portion 30a from the position S (sx, xy) determined in step S15 or step S16 and the current position P (pdx, pdy), that is, the first and second driving coils 31a. , 32a to calculate the first and second PWM duties dx, dy necessary for driving. In step S18, the first and second drive coils 31a and 32a are driven by the first and second PWM duties dx and dy via the driver circuit 29, and the movable portion 30a is moved. The operations in steps S17 to S18 are automatic control calculations used in PID automatic control for performing general proportional, integral, and differential calculations.

  In the present embodiment, the position detection using the Hall element is described as the magnetic field change detection element, but another detection element may be used as the magnetic field change detection element. Specifically, an MI sensor (high frequency carrier type magnetic field sensor), a magnetic resonance type magnetic field detection element, an MR element (magnetoresistance effect element) capable of obtaining position detection information of the movable part by detecting a change in the magnetic field. ). These can obtain the same effects as those of the present embodiment using Hall elements.

It is the perspective view seen from the back which shows the appearance of the imaging device of this embodiment. It is a front view of an imaging device. It is a circuit block diagram of an imaging device. It is a block diagram of an image blur correction apparatus. It is a block diagram of the cross section in the AA of FIG. It is a circuit block diagram of the part which detects the 1st direction x component of a biaxial Hall element and a Hall element signal processing circuit. It is a circuit block diagram of the part which detects the 2nd direction y component of a biaxial Hall element and a Hall element signal processing circuit. It is a flowchart of an image blur correction process performed as an interrupt process at regular intervals. It is a perspective view which shows the positional relationship of a Hall element part and a position detection magnet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging device 11 Pon button 12a Metering switch 13 Release button 13a Release switch 14 Image blur correction button 14a Image blur correction switch 17 LCD monitor 21 CPU
22 Imaging block 23 AE unit 24 AF unit 25 Angular velocity detection unit 26, 27 First and second angular velocity sensors 28 Amplifier / high pass filter circuit 29 Driver circuit 30 Image blur correction device 30a Movable unit 30b Fixed unit 31a, 32a First, first 2 driving coils 33b, 34b first and second driving permanent magnets 35b, 36b first and second driving yokes 39a imaging unit 39a1 imaging element 39a2 stage 39a3 pressing unit 39a4 optical low-pass filter 41a position detection magnet 43b position detection Yoke 44b Hall element part 45 Hall element signal processing circuit 451-456 First to sixth circuit 461-466 First to 16th circuit 49a Movable substrate 50a Moving shaft 51a-53a First to third horizontal moving bearings 54b-57b 1st-4th vertical movement axis Receiver 64a Plate 65b Base plate 66b Sensor substrate 67 Shooting lens A1 to A8 1st to 8th operational amplifier A21 to A28 21st to 28th operational amplifier dx, dy First and second PWM duty hh1, hh2 First and second horizontal directions Hall elements hv1, hv2 First and second vertical hall elements L1, L2 First and second effective lengths LX Optical axis px, py First and second detection position signals R1 to R19 First to 19th resistors R21 to R39 21st to 39th resistances vx, vy first and second angular velocities x1, x2 first and second horizontal potential differences y1, y2 first and second vertical potential differences

Claims (8)

An image sensor, a first direction orthogonal to the optical axis of the imaging lens for the image sensor, and a position detection magnet used to detect a position in the second direction orthogonal to the optical axis and the first direction; And a movable part movable in the first and second directions,
A fixing unit having a magnetic field change detection unit used to detect the position at a position facing the position detection magnet;
The magnetic field change detection unit includes first and second horizontal magnetic field change detection elements used for position detection in the first direction, and first and second vertical magnetic field change detections used for position detection in the second direction. Having an element,
The fixed part has a sensor substrate located at a position farther from the photographing lens than the movable part along the optical axis, and the magnetic field change detection part is provided on the sensor board;
The movable part has a plate made of a metal material sandwiched between the position detection magnet and the image sensor while being in contact with the position detection magnet and the image sensor,
The optical axis passes through the vicinity of the center of the surface of the position detection magnet facing the magnetic field change detection unit when the vicinity of the center of the image sensor is in a positional relationship passing through the optical axis due to the movement of the movable unit. Image blur correction device.   2. The image blur correction apparatus according to claim 1, wherein when the positional relationship is established, the movable portion is positioned at the center of a moving range in both the first and second directions. The surface of the position detection magnet facing the magnetic field change detection unit is a square formed by a line parallel to one of the first and second directions, and the position detection magnet is the optical axis. N pole and S pole are arranged in a third direction parallel to
When in the positional relationship, the positions in the second direction of the first and second horizontal direction magnetic field change detecting elements are both opposed to the middle of the square in the second direction, and the positions in the first direction. Are opposed to the vicinity of both end portions of the square in the first direction, and the positions of the first and second vertical magnetic field change detecting elements in the first direction are both in the middle of the square in the first direction. The image blur correction device according to claim 2, wherein the image blur correction apparatus faces the vicinity and faces the vicinity of both ends of the square in the second direction. The image blur correction apparatus according to claim 1, wherein the position detection magnet is an electromagnet, and the plate is in contact with a magnetic material constituting a magnetic core of the electromagnet . The image blur correction apparatus according to claim 1 , wherein the position detection magnet is a permanent magnet, and the plate is a magnetic material that is attracted by the magnetic force from the position detection magnet.   2. The image blur correction device according to claim 1, wherein the fixing unit includes a position detection yoke made of a magnetic material on a back side of the magnetic field change detection unit facing the position detection magnet. .   The first and second horizontal magnetic field change detecting elements, the first and second vertical magnetic field change detecting elements are any one of a Hall element, an MI sensor, a magnetic resonance type magnetic field detecting element, and an MR element. The image blur correction device according to claim 1. The magnetic field change detection unit is a biaxial Hall element,
2. The image blur correction apparatus according to claim 1, wherein each of the first and second horizontal magnetic field change detection elements and the first and second vertical magnetic field change detection elements is a Hall element.

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