JP4484555B2 - 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 an apparatus in which a movable part including an image blur correction lens is moved by a magnet and a coil, and position detection before and after the movement is performed by a Hall element and a magnet.
JP 2002-229090 A

  However, in the position detection of the movable part using the Hall element as in the apparatus of Patent Document 1, the Hall element used for position detection in the first direction orthogonal to the optical axis of the photographing lens, the optical axis, and the first direction The circuits for supplying power to the input terminals of the Hall elements used for detecting the position in the second direction orthogonal to are different. In addition, the signal processing circuits for outputting the detection position signals for specifying the positions in the first and second directions by performing signal processing on the outputs from the output terminals of the respective Hall elements are also separate.

  Accordingly, an object of the present invention is to reduce the size of the signal processing circuit of two or more magnetic field change detection elements used for position detection in two directions perpendicular to the optical axis and perpendicular to each other and perpendicular to each other. Is to provide a device.

  An image shake correction apparatus for an image pickup apparatus according to the present invention includes either an image pickup element or an image shake correction lens, and is orthogonal to the first direction orthogonal to the optical axis of the photographing lens and the optical axis and the first direction. A movable portion movable in the second direction; and a fixed portion that supports the movable portion so as to be movable in the first and second directions. Either the movable portion or the fixed portion is a first direction of the movable portion. The magnetic field change detecting element unit has a horizontal magnetic field change detecting element used for detecting the position of the movable portion and a vertical magnetic field change detecting element used for detecting the position of the movable part in the second direction. A magnetic field change detection element signal processing circuit unit that outputs a detection position signal for specifying a position in the first and second directions to detect the position of the movable part from the output signal of the detection element and the vertical direction magnetic field change detection element and performs signal processing. In addition, the magnetic field change detection element signal processing circuit The unit supplies power to the input terminals of the horizontal magnetic field change detection element and the vertical magnetic field change detection element, and performs position detection from the output terminals of the horizontal magnetic field change detection element and the vertical magnetic field change detection element. A signal processing circuit, a magnetic field change detecting element that supplies power to the input terminal, a power supply changeover switch that switches between the horizontal magnetic field change detecting element and the vertical magnetic field change detecting element, and an output from the output terminal And a signal processing changeover switch unit that switches a magnetic field change detecting element for signal processing to either a horizontal magnetic field change detecting element or a vertical magnetic field change detecting element.

  As a result, the power supply circuit and the signal processing circuit can be shared by the horizontal magnetic field change detecting element and the vertical magnetic field change detecting element, and the circuit scale of the magnetic field change detecting element signal processing circuit unit can be reduced. Is possible.

  Preferably, the movable part has a magnetic field change detecting element part, and the fixed part opposes the position detecting magnet part used for detecting the position of the movable part in the first and second directions to the magnetic field change detecting element part. The magnetic field change detection element section has one horizontal magnetic field change detection element and one vertical magnetic field change detection element, and the position detection magnet section is located at a position facing the horizontal magnetic field change detection element. A first position detection magnet that is attached and used for position detection in the first direction, and a second position detection that is attached to a position facing the vertical magnetic field change detection element and used for position detection in the second direction. It consists of a magnet.

  More preferably, the movable part includes a first drive coil used for moving the movable part in the first direction and a second drive coil used for moving the movable part in the second direction. The first position detection magnet is also used to move the movable part in the first direction, and the second position detection magnet is also used to move the movable part in the second direction.

  Preferably, the detection position signal at the time of detecting the position in the first direction is inputted, the position of the movable portion in the first direction is calculated after A / D conversion, and the detection position signal at the time of detecting the position in the second direction is inputted. Control means for calculating the position of the movable part in the second direction after A / D conversion and controlling the movable part, the fixed part, and the magnetic field change detection element signal processing circuit part, and the control means includes a power supply changeover switch part. The switching of the signal processing changeover switch unit is controlled.

  Preferably, the magnetic field change detection element signal processing circuit unit is a differential amplifier circuit that amplifies a signal difference between the output terminals of the horizontal magnetic field change detection element and the vertical magnetic field change detection element as a signal processing circuit. And a subtracting amplifier circuit for obtaining a potential difference from the difference between the signal difference amplified by the differential amplifier circuit and the reference voltage and amplifying the potential difference to obtain a detection position signal.

  More preferably, the differential amplifier circuit includes first and second operational amplifiers, the signal processing changeover switch unit includes first to fourth switches, and one of the output terminals of the horizontal magnetic field change detection element is: The first switch is connected to the non-inverting input terminal of the first operational amplifier, and the other terminal is connected to the non-inverting input terminal of the second operational amplifier A2 via the third switch to detect the vertical magnetic field change. One of the output terminals of the element is connected to the non-inverting input terminal of the first operational amplifier via the second switch, and the other terminal is connected to the non-inverting input terminal of the second operational amplifier via the fourth switch. Is done.

  More preferably, the differential amplifier circuit has first to third resistors, the inverting input terminal of the first operational amplifier is connected to the first and second resistors, and the inverting input terminal of the second operational amplifier is the first and second resistors. The output terminal of the first operational amplifier is connected to the second resistor and the subtracting amplifier circuit, and the output terminal of the second operational amplifier is connected to the third resistor and the subtracting amplifier circuit.

  More preferably, the subtracting amplifier circuit has a third operational amplifier, the output terminal of the first operational amplifier is connected to the inverting input terminal of the third operational amplifier via the fourth resistor, and the output terminal of the third operational amplifier has the fifth resistor. Is connected to the inverting input terminal of the third operational amplifier, the output terminal of the second operational amplifier is connected to the non-inverting input terminal of the third operational amplifier via the sixth resistor, and the non-inverting input terminal of the third operational amplifier is the seventh resistor. And is connected to a reference voltage.

  Preferably, the power supply circuit of the magnetic field change detection element signal processing circuit unit includes a fourth operational amplifier, the power supply changeover switch unit includes fifth to eighth switches, and an inverting input of the fourth operational amplifier. The terminal is connected to one of the input terminals of the horizontal magnetic field change detecting element via the fifth switch, and is connected to one of the input terminals of the vertical magnetic field change detecting element via the sixth switch. The output terminal is connected to the other input terminal of the horizontal magnetic field change detecting element via the seventh switch, and is connected to the other input terminal of the vertical magnetic field change detecting element via the eighth switch.

  Preferably, the detection element of each of the horizontal direction magnetic field change detection element and the vertical direction magnetic field change detection element is a Hall element, an MI sensor, a magnetic resonance type magnetic field detection element, or an MR element.

  As described above, according to the present invention, the size of the signal processing circuit of two or more magnetic field change detection elements used for position detection in two directions perpendicular to each other and perpendicular to the optical axis is reduced. An image blur correction apparatus can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 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.

  The parts related to the imaging of the imaging device 1 are the Pon button 11 for switching on / off the main power supply, 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 correcting unit 30. 39a and a photographing lens 67. The on / off state of the Pon switch 11a is switched in response to the pressing of the Pon button 11, and thereby the on / off state of the main power supply of the imaging device 1 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 CPU 21 is a control unit that controls each unit related to imaging and controls each unit related to image blur correction described later.

  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 image blur correction device, that is, the portion related to the image blur correction of the imaging apparatus 1 includes the image blur correction button 14, the CPU 21, the angular velocity detection unit 25, the driver circuit 29, the image blur correction unit 30, and the signal processing circuit unit of the magnetic field change detection element. It comprises a Hall element signal processing circuit unit 45 and a photographic 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 unit 30 are driven at regular intervals independently of other operations such as photometry. Thus, 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 unit 30, the Hall element signal processing circuit unit 45 as the signal processing circuit unit of the magnetic field change detection element, and the 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 and sets 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 unit 30 moves the imaging unit 39a to the position S to be moved which is calculated and set by the CPU 21, thereby eliminating the deviation of the optical axis LX on the imaging plane of the subject image caused by the blur and This is a device that keeps the position of the image plane constant and corrects image blur, and includes a movable portion 30a including an imaging portion 39a and a movable region, and a fixed portion 30b. The image blur correction unit 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 driving of the movable portion 30a of the image blur correction unit 30 is performed by the 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 44a and the Hall element signal processing circuit part 45. A detected position signal pxy is input to the A / D 2 of the CPU 21 as information on the detected position P. The detected position signal pxy is A / D converted via A / D2. The data after A / D conversion with respect to the detected position signal pxy output at the time of position detection in the first direction x is set as pdx as the first direction x component of the position P. The data after A / D conversion with respect to the detected position signal pxy output at the time of detecting the position in the second direction y is set as pdy as the second direction y component of the position P. 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 part 30a includes first and second driving coils 31a and 32a, an imaging part 39a, a hall element part 44a as a magnetic field change detecting element part, a movable substrate 49a, a moving shaft 50a, and first to third horizontal moving parts. It has bearing parts 51a-53a and plate 64a.

  The fixed portion 30b includes two first and second position detection and drive magnets 411b and 412b, first and second position detection and drive yokes 431b and 432b, and first to fourth vertical movements as position detection magnet portions. Bearing portions 54b to 57b and a base plate 65b.

  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). 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 optical axis LX of the photographic lens 67 is in a positional relationship passing through the vicinity of the center of the image sensor 39a1, the movable portion 30a is provided 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, and a movable substrate 49a 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 on which a sheet-like and spiral coil pattern is formed, and a hall element portion 44a. The coil pattern of the first drive coil 31a includes a movable part including the first drive coil 31a by the electromagnetic force generated from the direction of the current of the first drive coil 31a and the direction of the magnetic field of the first position detection and drive magnet 411b. In order to move 30a in the first direction x, it has a line parallel to the second direction y. The coil pattern of the second driving coil 32a includes a movable part including the second driving coil 32a by an electromagnetic force generated from the direction of the current of the second driving coil 32a and the direction of the magnetic field of the second position detection and driving magnet 412b. In order to move 30a in the second direction y, a line parallel to the first direction x is provided. The Hall element portion 44a will be described later.

  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 first position detection and drive magnet 411b is attached to the movable portion 30a side of the fixed portion 30b so as to face the first drive coil 31a and the horizontal hall element hh10. The second position detection and drive magnet 412b is attached to the movable portion 30a side of the fixed portion 30b so as to face the second drive coil 32a and the vertical hall element hv10.

  The first position detection and drive magnet 411b is on the base plate 65b of the fixed portion 30b and the first position detection and drive yoke 431b attached to the movable portion 30a side in the third direction z. N pole and S pole are mounted side by side in one direction x. The length of the first position detection and drive magnet 411b in the second direction y is such that the magnetic field exerted on the first drive coil 31a and the horizontal hall element hh10 does not change when the movable portion 30a moves in the second direction y. The first driving coil 31a is set to be longer than the first effective length L1 in the second direction y.

  The second position detection and drive magnet 412b is on the base plate 65b of the fixed portion 30b and the second position detection and drive yoke 432b attached to the movable portion 30a side in the third direction z. N pole and S pole are mounted side by side in two directions y. The length of the second position detection and drive magnet 412b in the first direction x does not change the magnetic field exerted on the second drive coil 32a and the vertical hall element hv10 when the movable part 30a moves in the first direction x. The second driving coil 32a is set to be longer than the second effective length L2 in the first direction x.

  The first position detecting / driving yoke 431b is formed of a polygonal soft magnetic material having a U-shape when viewed from the second direction y, and the first position detecting / driving magnet 411b, first driving The coil 31a and the horizontal hall element hh10 are mounted on the base plate 65b of the fixed portion 30b so as to sandwich the coil 31a and the horizontal hall element hh10 in the third direction z. The portion of the first position detection and drive yoke 431b on the side in contact with the first position detection and drive magnet 411b serves to prevent the magnetic field of the first position detection and drive magnet 411b from leaking to the surroundings. The first position detection and drive magnet 411b, the first drive coil 31a, and the portion facing the movable substrate 49a in the first position detection and drive yoke 431b are the same as the first position detection and drive magnet 411b. The first driving coil 31a and the first position detection and driving magnet 411b serve to increase the magnetic flux density between the horizontal hall element hh10.

  The second position detection and drive yoke 432b is made of a polygonal soft magnetic material having a U-shape when viewed in the first direction x, and the second position detection and drive magnet 412b and second drive The coil 32a and the vertical hall element hv10 are mounted on the base plate 65b of the fixing portion 30b so as to be sandwiched between the third direction z. The portion of the second position detection and drive yoke 432b on the side in contact with the second position detection and drive magnet 412b serves to prevent the magnetic field of the second position detection and drive magnet 412b from leaking to the surroundings. The second position detection and drive magnet 412b, the second drive coil 32a, and the portion facing the movable substrate 49a in the second position detection and drive yoke 432b are connected to the second position detection and drive magnet 412b and the second magnet. The second driving coil 32a and the second position detection and driving magnet 412b serve to increase the magnetic flux density between the vertical hall element hv10.

  The hall element unit 44a has two hall elements that are magnetoelectric conversion elements using the Hall effect, and detects the current position P (detection position signal pxy) in the first direction x and the second direction y of the movable part 30a. It is a uniaxial Hall element. Of the two hall elements, the hall element for position detection in the first direction x is the horizontal hall element hh10 as a horizontal magnetic field change detection element, and the hall element for position detection in the second direction y is the vertical magnetic field change detection element. As a vertical hall element hv10.

  The horizontal hall element hh10 is mounted on the movable substrate 49a of the movable part 30a as viewed from the third direction z and at a position facing the first position detection and driving magnet 411b of the fixed part 30b. The vertical hall element hv10 is mounted on the movable substrate 49a of the movable part 30a as viewed from the third direction z and at a position facing the second position detection and drive magnet 412b of the fixed part 30b.

  The base plate 65b is a plate-like member that serves as a base to which the first and second position detection and drive yokes 431b and 432b are attached in the fixed portion 30b, and is arranged in parallel with the imaging surface of the imaging element 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 and the hall element portion 44a are on the opposite side of the movable substrate 49a from the side where the photographing lens 67 is located, and the first and second position detection and drive magnets 411b and 412b are The base plate 65b is disposed on the side where the photographing lens 67 is present.

  The hall element signal processing circuit unit 45 detects the potential difference xy10 between the output terminals of the horizontal hall element hh10 and the vertical hall element hv10 from the output signals of the horizontal hall element hh10 and the vertical hall element hv10, and the first A detection position signal pxy specifying the position in the direction x or the second direction y is output to the A / D 2 of the CPU 21.

  A circuit configuration relating to input / output signals of the horizontal hall element hh10 and the vertical hall element hv10 in the hall element signal processing circuit unit 45 will be described.

  A common output unit of the horizontal hall element hh10 and the vertical hall element hv10 in the hall element signal processing circuit unit 45 includes a first circuit 451 and a second circuit 452. The common input section of the horizontal hall element hh10 and the vertical hall element hv10 in the hall element signal processing circuit section 45 includes a third circuit 453.

  The Hall element signal processing circuit unit 45 is a first to eighth switch as a switch for switching the first and third circuits 451 and 453 to connect to either the horizontal hall element hh10 or the vertical hall element hv10. It has switches SW1-SW8.

  Among the first to eighth switches SW1 to SW8, the first to fourth switches SW1 to SW4 function as signal processing changeover switch units, and output terminals of the horizontal hall element hh10 and the vertical hall element hv10, and the first circuit. The connection is switched with 451.

  The fifth to eighth switches SW5 to SW8 switch the connection between the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 and the third circuit 453 as a power supply changeover switch unit.

  The first, third, fifth, and seventh switches SW1, SW3, SW5, and SW7 are connected to the port P22 of the CPU 21, turned off when the output signal from the port P22 is Lo, and turned on when the output signal is Hi. Is done. The output signal from the port P22 is set to Hi when detecting the position in the first direction x under the control of the CPU 21.

  The second, fourth, sixth, and eighth switches SW2, SW4, SW6, and SW8 are connected to the port P23 of the CPU 21, turned off when the output signal from the port P23 is Lo, and turned on when the output is Hi. Is done. The output signal from the port P23 is set to Hi when detecting the position in the second direction y under the control of the CPU 21.

  The output terminal of the horizontal hall element hh10 is connected to the first circuit 451 through the first and third switches SW1 and SW3. The output terminal of the vertical hall element hv10 is connected to the first circuit 451 via the second and fourth switches SW2 and SW4. The first circuit 451 is connected to the second circuit 452.

  The first circuit 451 is a differential amplifier circuit that amplifies the signal difference between the output terminals of either the horizontal hall element hh10 or the vertical hall element hv10 switched by the first and third switches SW1 and SW3. The second circuit 452 obtains a potential difference xy10 (hall output voltage) between the output terminals of the horizontal hall element hh10 or the vertical hall element hv10 from the difference between the amplified signal difference and the reference voltage Vref, and constant amplification is performed on this. This is a subtracting amplifier circuit that multiplies the rate AA1 to obtain the detected position signal pxy.

  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 horizontal hall element hh10 is connected to the non-inverting input terminal of the first operational amplifier A1 via the first switch SW1, and the other terminal is connected to the second operational amplifier via the third switch SW3. Connected to the non-inverting input terminal of A2. One of the output terminals of the vertical hall element hv10 is connected to the non-inverting input terminal of the first operational amplifier A1 via the second switch SW2, and the other terminal is connected to the second operational amplifier via the fourth switch SW4. Connected to the non-inverting input terminal of 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 fourth resistor R4 of the second circuit 452. The output terminal of the second operational amplifier A2 is connected to the third resistor R3 and the sixth resistor R6 of the second circuit 452.

  The second circuit 452 includes fourth to seventh resistors R4 to R7 and a third operational amplifier A3. The inverting input terminal of the third operational amplifier A3 is connected to the fourth resistor R4 and the fifth resistor R5, the non-inverting input terminal is connected to the sixth resistor R6 and the seventh resistor R7, and the output terminal is connected to the fifth resistor R5. The When the Hi signal is output from the port P22 of the CPU 21 from the output terminal of the third operational amplifier A3 and the first and third switches SW1 and SW3 are turned on, as the first direction x component of the position detection information, When the detection position signal pxy obtained by multiplying the potential difference xy10 by a constant amplification factor AA1 is output and the Hi signal is output from the port P23 of the CPU 21, the position detection is performed when the second and fourth switches SW2 and SW4 are turned on. A detection position signal pxy obtained by multiplying the potential difference xy10 by a constant amplification factor AA1 is output as the y component of the second direction of information. One terminal of the seventh resistor R7 is connected to the power source of the reference voltage Vref.

  The second and third resistors R2 and R3 are set to the same resistance value, the fourth and sixth resistors R4 and R6 are set to the same resistance value, and the fifth and seventh resistors R5 and R7 are set to the same resistance value. The value of the amplification factor AA1 is calculated from the ratio of the resistance values of the fifth resistor R5 and the fourth resistor R4.

  The third circuit 453 includes an eighth resistor R8 and a fourth operational amplifier A4. The inverting input terminal of the fourth operational amplifier A4 is connected to the eighth resistor R8. The inverting input terminal of the fourth operational amplifier A4 is connected to one of the input terminals of the horizontal hall element hh10 via the fifth switch SW5, and one of the input terminals of the vertical hall element hv10 via the sixth switch SW6. Connected. The output terminal of the fourth operational amplifier A4 is connected to the other input terminal of the horizontal hall element hh10 via the seventh switch SW7, and is connected to the other input terminal of the vertical hall element hv10 via the eighth switch SW8. The One terminal of the eighth resistor R8 is grounded.

  The potential of the non-inverting input terminal of the fourth operational amplifier A4 is set to a constant voltage Vfxy corresponding to a constant current value at the input terminals of the horizontal hall element hh10 and the vertical hall element hv10.

  In the prior art, signal processing from the output terminals of the horizontal hall element hh10 and the vertical hall element hv10 has been performed by separate circuits. Therefore, the Hall element signal processing circuit unit 45 uses a differential amplification circuit and a subtraction amplification circuit corresponding to the first and second circuits 451 and 452 for position detection in the first direction x and position detection in the second direction y. It is necessary to have two each as a circuit scale.

  In the present embodiment, signal processing from the output terminals of the horizontal hall element hh10 and the vertical hall element hv10 is performed by the same first and second circuits 451 and 452 via the first to fourth switches SW1 to SW4. Is called. Accordingly, the horizontal hall element hh10 and the vertical hall element hv10 share a differential amplification circuit and a subtraction amplification circuit, which are one signal processing circuit, so that the circuit scale can be reduced.

  In addition, power supply to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 has been performed by separate circuits. Therefore, the Hall element signal processing circuit unit 45 needs to have two power supply circuits corresponding to the third circuit 453 for detecting the position in the first direction x and for detecting the position in the second direction y. Was made larger.

  In the present embodiment, power supply to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 is performed by the same third circuit 453 via the fifth to eighth switches SW5 to SW8. Accordingly, since the horizontal hall element hh10 and the vertical hall element hv10 share one power supply circuit, the circuit scale can be reduced.

  Next, the procedure of image blur correction processing performed independently of other operations as interrupt processing every predetermined time (1 ms) will be described with reference to the flowchart of FIG. Note that the output signals from the ports P22 and P23 of the CPU 21 are both set to Lo immediately after the imaging apparatus 1 is turned on and before the first image blur correction process interrupt operation is performed.

  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 Hi signal is output from the port P22 of the CPU 21, and the constant voltage Vfxy is applied to the input terminal of the horizontal hall element hh10 via the third circuit 453, the fifth and seventh switches SW5 and SW7. In step S14, the position in the first direction x is detected by the horizontal hall element hh10 of the hall element unit 44a, and the detection position calculated by the hall element signal processing circuit unit 45 through the first and third switches SW1 and SW3. The signal pxy is A / D converted and inputted via A / D2 of the CPU 21, and the first direction x component pdx of the current position P is obtained.

  In step S15, the Lo signal is output from the port P22 of the CPU 21, the Hi signal is output from the port P23, and the constant voltage Vfxy is supplied to the vertical hall element via the third circuit 453, the sixth and eighth switches SW6 and SW8. Applied to the input terminal of hv10. In step S16, the position in the second direction y is detected by the vertical hall element hv10 of the hall element section 44a, and the detected position calculated by the hall element signal processing circuit section 45 via the second and fourth switches SW2 and SW4. The signal pxy is A / D converted and inputted via A / D2 of the CPU 21, and the second direction y component pdy of the current position P is obtained. In step S17, the output from the port P23 of the CPU 21 is made a Lo signal.

  In step S18, it is determined whether or not IS = 0. When IS = 0, that is, when the correction mode is not set, in step S19, the position S (sx, sy) to which the movable part 30a should move is set to be 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 S20, the position S (sx, sy) to which the movable part 30a should move is calculated and set from the first and second angular velocities vx and vy obtained in step S12.

  In step S21, the driving force D required to move the movable portion 30a from the position S (sx, sy) and the current position P (pdx, pdy) set in step S19 or step S20, that is, the first and second driving coils 31a. , 32a required to drive the first and second PWM duties dx, dy are calculated. In step S22, the first and second PWM coils da and dy are used to drive the first and second drive coils 31a and 32a via the driver circuit 29, thereby moving the movable part 30a. The operations in steps S21 and S22 are automatic control calculations used in PID automatic control for performing general proportional, integral, and differential calculations.

  In the present embodiment, an embodiment has been described in which the position detection of the movable portion 30a in the first direction x is performed using one horizontal hall element hh10 and the position detection in the second direction y is performed using one vertical hall element hv10. However, the number of Hall elements used for position detection is not limited to this.

  A circuit for supplying power to each input terminal of two or more Hall elements used for position detection in two directions perpendicular to the optical axis LX and perpendicular to each other, and a circuit for signal processing from the output terminal are made common through a switch. This is because it is possible to reduce the scale of the signal processing circuit of the Hall element.

  In the present embodiment, the configuration in which the position detecting magnet and the driving magnet are shared in each of the first direction x and the second direction y has been described.

  Further, in the present embodiment, the position detecting Hall element portion 44a is disposed on the movable portion 30a, and the position detecting magnets (first and second position detecting and driving magnets 411b and 412b) are disposed on the fixed portion 30b. However, the configuration of the movable portion 30a and the fixed portion 30b may be reversed, that is, the movable portion 30a may include a position detection magnet, and the fixed portion 30b may include a Hall element portion.

  Further, although the position detection by the Hall element unit 44a using the Hall element as the magnetic field change detection element has been described, 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), or the like.

  In addition, the imaging unit 39a including the imaging element 39a1 has been described as being arranged and moved on the movable unit 30a. However, the imaging unit 39a is fixed, and the same applies to the configuration in which the image blur correction lens is arranged and moved on the movable unit 30a. The effect is obtained.

It is the perspective view seen from the back which shows the appearance of the imaging device in 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 part. It is a block diagram of the cross section in the AA of FIG. It is a circuit block diagram of a Hall element part and a Hall element signal processing circuit part. It is a flowchart of an image blur correction process performed as an interrupt process at regular intervals.

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 sensor 28 amplifier / high pass filter circuit 29 driver circuit 30 image blur correction unit 30a movable unit 30b fixed unit 31a, 32a first, first Two driving coils 39a Imaging unit 39a1 Imaging element 39a2 Stage 39a3 Holding unit 39a4 Optical low-pass filter 411b, 412b First and second position detection and driving magnets 431b and 432b First and second position detection and driving yoke 44a Hall element Part 45 Hall element signal processing circuit part 451 to 453 First to third circuit 49a Movable substrate 50a Movement shaft 51a to 53a First to third horizontal movement bearing parts 54b to 57b First to fourth vertical movement bearing parts 64a plate 65b base plate 67 Dx, dy First and second PWM duty hh10 Horizontal hall element hv10 Vertical hall element L1, L2 First and second effective length LX Optical axis of photographic lens pxy Detection position signal SW1 to SW8 First to eighth switches vx , Vy first and second angular velocities

Claims (10)

A movable part having either one of an image sensor or an image blur correction lens, movable in a first direction orthogonal to the optical axis of the photographing lens, and in a second direction orthogonal to the optical axis and the first direction;
A fixed portion that movably supports the movable portion in the first and second directions;
Either the movable part or the fixed part includes a horizontal magnetic field change detection element used for detecting the position of the movable part in the first direction and a vertical direction used for detecting the position of the movable part in the second direction. A magnetic field change detecting element unit having a magnetic field change detecting element;
Magnetic field change for signal processing by outputting a detection position signal for specifying the position in the first and second directions for detecting the position of the movable part from the output signals of the horizontal magnetic field change detection element and the vertical magnetic field change detection element A detection element signal processing circuit unit,
The magnetic field change detecting element signal processing circuit unit includes a circuit for supplying power to the input terminals of the horizontal magnetic field change detecting element and the vertical magnetic field change detecting element, the horizontal magnetic field change detecting element, and the vertical magnetic field change detecting element. The signal processing circuit for performing the position detection from the output terminal of the first and the magnetic field change detecting element for supplying power to the input terminal are either the horizontal magnetic field change detecting element or the vertical magnetic field change detecting element. A power supply changeover switch unit that switches, a signal processing changeover switch unit that switches a magnetic field change detection element that performs signal processing of an output signal from the output terminal to either the horizontal magnetic field change detection element or the vertical magnetic field change detection element; An image blur correction apparatus comprising: The movable part has the magnetic field change detecting element part,
The fixed part has a position detection magnet part used for position detection in the first and second directions of the movable part at a position facing the magnetic field change detection element part,
The magnetic field change detecting element section has one horizontal magnetic field change detecting element and one vertical magnetic field change detecting element,
The position detection magnet unit is attached to a position facing the horizontal magnetic field change detection element and used for position detection in the first direction, and the vertical magnetic field change detection element. The image blur correction apparatus according to claim 1, further comprising: a second position detection magnet that is attached to an opposing position and is used for position detection in the second direction.   The movable portion includes a first drive coil used for moving the movable portion in the first direction, and a second drive coil used for moving the movable portion in the second direction. The first position detection magnet is also used to move the movable part in the first direction, and the second position detection magnet moves the movable part in the second direction. The image blur correction apparatus according to claim 2, wherein the image blur correction apparatus is also used for the purpose. The detected position signal at the time of detecting the position in the first direction is inputted, the position of the movable part in the first direction is calculated after A / D conversion, and the detected position signal at the time of detecting the position in the second direction is inputted. Control means for calculating the position of the movable part in the second direction after A / D conversion and controlling the movable part, the fixed part, and the magnetic field change detection element signal processing circuit part,
The image blur correction apparatus according to claim 1, wherein the control unit controls switching of the power supply changeover switch unit and the signal processing changeover switch unit.   The magnetic field change detection element signal processing circuit unit is a differential amplifier circuit that amplifies a signal difference between output terminals of the horizontal magnetic field change detection element and the vertical magnetic field change detection element as the signal processing circuit; 2. The image according to claim 1, further comprising: a subtracting amplifier circuit that obtains a potential difference from a difference between the signal difference amplified by the differential amplifier circuit and a reference voltage, amplifies the potential difference, and obtains the detection position signal. Blur correction device. The differential amplifier circuit includes first and second operational amplifiers,
The signal processing changeover switch unit includes first to fourth switches,
One output terminal of the horizontal magnetic field change detecting element is connected to the non-inverting input terminal of the first operational amplifier via the first switch, and the other terminal is connected to the non-inverting input terminal via the third switch. One of the output terminals of the vertical direction magnetic field change detecting element is connected to the non-inverting input terminal of the first operational amplifier via the second switch, and is connected to the non-inverting input terminal of the second operational amplifier A2. The image blur correction apparatus according to claim 5, wherein the terminal is connected to a non-inverting input terminal of the second operational amplifier via the fourth switch. The differential amplifier circuit has first to third resistors,
The inverting input terminal of the first operational amplifier is connected to the first and second resistors, the inverting input terminal of the second operational amplifier is connected to the first and third resistors, and the output terminal of the first operational amplifier is the first operational amplifier. 7. The image blur correction apparatus according to claim 6, wherein the second resistor and the subtracting amplifier circuit are connected to each other, and the output terminal of the second operational amplifier is connected to the third resistor and the subtracting amplifier circuit.   The subtracting amplifier circuit includes a third operational amplifier, an output terminal of the first operational amplifier is connected to an inverting input terminal of the third operational amplifier via a fourth resistor, and an output terminal of the third operational amplifier includes a fifth resistor. And an output terminal of the second operational amplifier is connected to a non-inverting input terminal of the third operational amplifier via a sixth resistor, and a non-inverting input terminal of the third operational amplifier. The image blur correction device according to claim 7, wherein the image blur correction device is connected to the reference voltage via a seventh resistor. The circuit for supplying power to the magnetic field change detection element signal processing circuit unit includes a fourth operational amplifier,
The power supply changeover switch unit has fifth to eighth switches,
The inverting input terminal of the fourth operational amplifier is connected to one of the input terminals of the horizontal magnetic field change detecting element via the fifth switch, and the input terminal of the vertical magnetic field change detecting element via the sixth switch. And the output terminal of the fourth operational amplifier A4 is connected to the other input terminal of the horizontal magnetic field change detecting element via the seventh switch, and the vertical magnetic field via the eighth switch. The image blur correction apparatus according to claim 1, wherein the image blur correction apparatus is connected to the other input terminal of the change detection element. The detection element of each of the horizontal direction magnetic field change detection element and the vertical direction magnetic field change detection element is a Hall element, an MI sensor, a magnetic resonance type magnetic field detection element, or an MR element. Image blur correction device.

Images