JP4662786B2 - 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 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 a movable part using a magnetic field change detection element such as a Hall element as in the device of Patent Document 1, a constant voltage is applied to the input terminal of the magnetic field change detection element both at the time of position detection and at other times. Was applied, and current was consumed unnecessarily.

  Accordingly, an object of the present invention is to provide an apparatus capable of performing position detection with low power consumption in position detection of an image blur correction apparatus.

  An image blur correction apparatus for an image pickup apparatus according to the present invention includes either an image pickup element or an image blur correction lens, and is orthogonal to a first direction orthogonal to the optical axis of the photographing lens, and to the optical axis and the first direction. A movable portion movable in the second direction, and a fixed portion that supports the movable portion in a movable manner in the first and second directions, and either the movable portion or the fixed portion is arranged in the first direction of the movable portion. A magnetic field change detection unit having a horizontal magnetic field change detection element used for position detection and a vertical magnetic field change detection element used for position detection in the second direction of the movable part, and when detecting the position of the movable part Applies a voltage between the input terminals of the horizontal direction magnetic field change detection element and the vertical direction magnetic field change detection element, and stops the voltage application except during position detection. Thereby, it becomes possible to suppress the power consumption by stopping the voltage application to the magnetic field change detection unit in an unnecessary time zone other than the time of position detection.

  Preferably, a first detection position signal for specifying a position in the first direction is detected from the output signal of the horizontal magnetic field change detection element to detect the position of the movable part, and the output of the movable part is detected from the output signal of the vertical magnetic field change detection element. A signal processing unit that outputs a second detection position signal for specifying a position in the second direction for position detection, and first and second directions of the movable unit after the first and second detection position signals are input and A / D converted. And a control means for controlling the movable part, the fixed part and the signal processing part. When detecting the position of the movable part, a voltage of a constant voltage value is applied from the control means via the signal processing part. The voltage application performed from the control means via the signal processing unit is stopped except at the time of position detection. As a result, it is possible to control the timing of applying the voltage to the magnetic field change detection unit by the control means.

  More preferably, when the position of the movable portion is detected, voltage is applied from the control means to all the operational amplifiers in the signal processing section, and voltage application from the control means is stopped except when the position is detected.

  More preferably, voltage application to all the operational amplifiers is performed prior to voltage application to the input terminals of the horizontal magnetic field change detection element and the vertical magnetic field change detection element, respectively. The stop is performed simultaneously with the stop of voltage application to the input terminals of the horizontal magnetic field change detecting element and the vertical magnetic field change detecting element. This makes it possible to ensure a stable waiting time for the operational amplifier.

  More preferably, it includes a memory unit that is connected to the control means, records a constant voltage value, and does not erase the contents even when the power is turned off. As a result, once the constant voltage value to apply voltage to the horizontal magnetic field change detection element and the vertical magnetic field change detection element is set, the constant voltage value is used without setting again after the power is turned off. Thus, a voltage can be applied to the input terminals of the horizontal direction magnetic field change detecting element and the vertical direction magnetic field change detecting element.

  Preferably, the movable part has a magnetic field change detection part, and the magnetic field change detection part has one horizontal magnetic field change detection element and one vertical magnetic field change detection element.

  More preferably, the magnetic field change detection unit is a uniaxial Hall element, and both the horizontal magnetic field change detection element and the vertical magnetic field change detection element are Hall elements.

  Preferably, the fixed portion has a position detection magnet portion used for position detection of the movable portion in the first and second directions at a position facing the magnetic field change detection portion, and the position detection magnet portion is A first position detecting magnet attached to a position facing the horizontal magnetic field change detecting element and used for position detection in the first direction; and a second position attached to a position facing the vertical magnetic field change detecting element. And a second position detecting magnet used for position detection.

  More preferably, the first and second position detection magnets are also used for movement of the movable portion in the first and second directions. This makes it possible to use one magnet for both the movement of the movable part and the position detection in one direction.

  Further, another image blur correction device of the imaging apparatus according to the present invention has either one of an image sensor or an image blur correction lens, and a movable part that is movable on a plane orthogonal to the optical axis of the photographing lens; A fixed portion that supports the movable portion so as to be movable on the plane, and either the movable portion or the fixed portion has a detection portion that is used to detect the position of the movable portion, and when the position of the movable portion is detected. Turns on the detection unit and turns off the detection unit except during position detection.

  As described above, according to the present invention, it is possible to provide an apparatus capable of performing position detection with low power consumption in position detection of an image blur correction apparatus.

  Hereinafter, the present embodiment 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 apparatus 1 are the Pon button 11 for switching on / off the power, 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 39a of the image blur correcting unit 30. 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, and thereby the on / off state of the 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 image blur correction portion of the image pickup 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, the Hall element signal processing circuit unit 45, and the photographing lens 67. And a memory unit 72.

  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.

  The memory unit 72 records the first constant voltage XVf and the second constant voltage YVf having constant voltage values applied to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 via the hall element signal processing circuit unit 45. A nonvolatile memory such as an EEPROM that can be electrically rewritten and whose contents are not erased even when the power is turned off. The memory unit 72 inputs and outputs signals at the port P6.

  Next, the 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, 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 calculated 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 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. 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.

  Driving of the movable portion 30a of the image blur correction unit 30 is performed 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 44a and the Hall element signal processing circuit part 45. Information on the detected position P is input to A / D2 and A / D3 of the CPU 21 as 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, respectively. . 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 drive coils 31a and 32a, an imaging portion 39a, a hall element portion 44a, a movable substrate 49a, a movement shaft 50a, first to third horizontal movement bearing portions 51a to 53a, and a 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). 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 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 first driving coil 31a has a movable part 30a including the first driving coil 31a by the 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 position detection and driving magnet 411b. In order to move in one direction x, a coil pattern formed by a line parallel to either the first direction x or the second direction y is provided. The second driving coil 32a has the movable part 30a including the second driving coil 32a in the first position by the 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 detecting and driving magnet 412b. In order to move in two directions y, a coil pattern formed by a line parallel to either the first direction x or the second direction y 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 (magnetic field change detection elements) using the Hall effect, and the current position P (first direction) in the first direction x and the second direction y of the movable part 30a. This is a uniaxial Hall element that detects a detection position signal px and a second detection position signal py). Of the two hall elements, a hall element for position detection in the first direction x is a horizontal hall element hh10, and a hall element for position detection in the second direction y is 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.

  In order to perform position detection by making the most of the range in which position detection with high accuracy can be performed using the linear change amount, the position of the horizontal hall element hh10 in the first direction x is light near the center of the image sensor 39a1. When in a positional relationship passing through the axis LX, it is desirable that the first position detection and driving magnet 411b be near the same distance as the north and south poles. Similarly, the position of the vertical hall element hv10 in the second direction y is the N pole and S pole of the second position detecting and driving magnet 412b when the vicinity of the center of the imaging element 39a1 passes through the optical axis LX. It is desirable to be in the vicinity of the same distance.

  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 horizontal potential difference x10 between the output terminals of the horizontal hall element hh10 from the output signal of the horizontal hall element hh10, and identifies the position in the first direction x based on the detected horizontal potential difference x10. The vertical potential difference y10 between the output terminals of the vertical hall element hv10 is detected from the first hall element signal processing circuit 450 that outputs the signal px to the A / D2 of the CPU 21 and the output signal of the vertical hall element hv10. A second hall element signal processing circuit 460 for outputting a second detection position signal py for specifying the position in the second direction y to the A / D 3 of the CPU 21.

  At the time of position detection, the first constant voltage XVf is applied to the input terminal of the horizontal hall element hh10 from the D / A0 of the CPU 21 via the first hall element signal processing circuit 450, and the input terminal of the vertical hall element hv10 is applied. The second constant voltage YVf is applied from the D / A 1 of the CPU 21 via the second Hall element signal processing circuit 460. Except for the time of position detection, the outputs of both D / A0 and D / A1 of the CPU 21 are set to zero. That is, the voltage application to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 is stopped.

  A circuit configuration relating to input / output signals of the horizontal hall element hh10 and the vertical hall element hv10 in the first and second hall element signal processing circuits 450 and 460 will be described.

  In the first hall element signal processing circuit 450, the output section of the horizontal hall element hh10 has a first circuit 451 and a third circuit 453, and the input section has a sixth circuit 456. In the second hall element signal processing circuit 460, the output section of the vertical hall element hv10 includes an eleventh circuit 461 and a thirteenth circuit 463, and the input section includes a sixteenth circuit 466.

  An output terminal of the horizontal hall element hh10 is connected to the first circuit 451, and the first circuit 451 is connected to the third circuit 453. The first circuit 451 is a differential amplifier circuit that amplifies a signal difference between the output terminals of the horizontal hall element hh10. The third circuit 453 obtains a horizontal potential difference x10 (hall output voltage) between the output terminals of the horizontal hall element hh10 from the difference between the amplified signal difference and the reference voltage Vref, and multiplies it by a certain amplification factor to obtain the first potential. It is a subtraction amplification circuit for obtaining one detection position signal px.

  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, 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 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 connected to the eighth resistor R8. The first detection position signal px obtained by multiplying the horizontal potential difference x10 by a constant amplification factor is output. One terminal of the tenth resistor R10 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 seventh and ninth resistors R7 and R9 are set to the same resistance value, and the eighth and tenth resistors R8 and R10 are set to the same resistance value.

  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 horizontal hall element hh10. The potential of the non-inverting input terminal of the eighth operational amplifier A8 is set to the first constant voltage XVf corresponding to the constant current value at the input terminal of the horizontal hall element hh10. The output terminal of the eighth operational amplifier A8 is connected to one input terminal of the horizontal hall element hh10. One terminal of the nineteenth resistor R19 is grounded.

  The output terminal of the vertical hall element hv10 is connected to the eleventh circuit 461, and the eleventh circuit 461 is connected to the thirteenth circuit 463. The eleventh circuit 461 is a differential amplifier circuit that amplifies a signal difference between the output terminals of the vertical hall element hv10. The thirteenth circuit 463 obtains a vertical potential difference y10 (hall output voltage) between the output terminals of the vertical hall element hv10 from the difference between the amplified signal difference and the reference voltage Vref, and multiplies it by a constant amplification factor to obtain the first potential. 2 is a subtraction amplification circuit for obtaining a detection position signal py.

  The eleventh circuit 461 includes 21st to 23rd resistors R21 to R23, 21st and 22nd operational amplifiers A21 and A22. One of the output terminals of the vertical hall element hv10 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 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 connected to the 28th resistor R28. The second detection position signal py obtained by multiplying the vertical potential difference y10 by a constant amplification factor is output. One terminal of the thirtieth resistor R30 is connected to the power source of the reference voltage Vref.

  The 22nd and 23rd resistors R22 and R23 are set to the same resistance value, the 27th and 29th resistors R27 and R29 are set to the same resistance value, and the 28th and 30th resistors R28 and R30 are set to the same resistance value.

  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 vertical hall element hv10. The potential at the non-inverting input terminal of the 28th operational amplifier A28 is set to the second constant voltage YVf corresponding to the constant current value at the input terminal of the vertical hall element hv10. The output terminal of the 28th operational amplifier A28 is connected to one input terminal of the vertical hall element hv10. One terminal of the 39th resistor R39 is grounded.

  At the time of position detection, a voltage is applied from the CPU 21 to all operational amplifiers in the first and second Hall element signal processing circuits 450 and 460 (not shown). Except for the time of position detection, the voltage application from the CPU 21 is stopped.

  In order to secure a stable waiting time for each operational amplifier, at the start of position detection, voltage application to all the operational amplifiers in the first and second Hall element signal processing circuits 450 and 460 is applied to the horizontal hall element hh10 and the vertical hall element. This is performed earlier than the first and second constant voltages XVf and YVf applied to the input terminals of hv10. Further, after the position detection is completed, the voltage application to all the operational amplifiers in the first and second Hall element signal processing circuits 450 and 460 is stopped to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10. This is performed simultaneously with the stop of voltage application.

  In the conventional technique, voltage application to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 has been performed directly from the power supply unit or the like without using the CPU 21. Therefore, voltage application is always performed while the Pon button 11 is turned on and the image pickup apparatus 1 is turned on regardless of whether position detection is performed. However, since voltage application to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 is only required for position detection, voltage application other than position detection is unnecessary power consumption. In the present embodiment, under the control of the CPU 21, voltage is applied to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 only at the time of position detection, thereby suppressing power consumption in unnecessary time zones. Is possible.

  Limiting the voltage application of the operational amplifier at the time of position detection also has an effect of suppressing power consumption in unnecessary time zones.

  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.

  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, voltage application to all the operational amplifiers in the first and second Hall element signal processing circuits 450 and 460 is started. In step S14, the first constant voltage XVf is applied from D / A0 of the CPU 21 to the input terminal of the horizontal hall element hh10 via the sixth circuit 456 of the first hall element signal processing circuit 450. The second constant voltage YVf is applied from the D / A1 of the CPU 21 to the input terminal of the vertical hall element hv10 via the sixteenth circuit 466 of the second hall element signal processing circuit 460. The first and second constant voltages XVf and YVf are recorded in the memory unit 72, and are read via the CPU 21 when the power of the imaging device 1 is turned on. In step S15, the first and second detected position signals px and py detected by the Hall element unit 44a and calculated by the Hall element signal processing circuit unit 45 are A / D via A / D2 and A / D3 of the CPU 21. The current position P (pdx, pdy) is obtained after being converted and input. In step S16, the outputs of D / A0 and D / A1 are made zero. That is, voltage application to the input terminals of the horizontal hall element hh10 and the vertical hall element hv10 is stopped. At the same time, voltage application to all the operational amplifiers in the first and second Hall element signal processing circuits 450 and 460 is stopped.

  In step S17, it is determined whether or not IS = 0. When IS = 0, that is, when the correction mode is not set, in step S18, 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 S19, the position S (sx, sy) where the movable part 30a should move is calculated and set from the first and second angular velocities vx, vy obtained in step S12.

  In step S20, 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 S18 or step S19, that is, the first and second driving coils 31a. , 32a required to drive the first and second PWM duties dx, dy are calculated. At step S21, the first and second PWM duties dx and dy drive the first and second drive coils 31a and 32a via the driver circuit 29, thereby moving the movable portion 30a. The operations in steps S20 and S21 are automatic control calculations used in PID automatic control that performs general proportional, integral, and differential calculations.

  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, the configuration has been described in which the position detecting Hall element portion 44a is disposed in the movable portion 30a, and the position detecting magnets (first and second position detecting and driving magnets 411b and 412b) are disposed in the fixed portion 30b. 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 detecting magnet, and the fixed portion 30b may include a Hall element portion.

  Further, any of the magnets as a device for generating a magnetic field may be a magnet that always generates a magnetic field or an electromagnet that generates a magnetic field as necessary.

  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.

  Further, although the position detection using the Hall element has been described as the magnetic field change detection element, 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.

  In the present embodiment, the movable part 30a is movable in the first direction x and the second direction y with respect to the fixed part 30b, and detects the position in the first direction x and the position in the second direction y. Thus, the position of the movable part 30a is detected. However, the movement and position detection of the movable part 30a are not limited to this, but on a plane perpendicular to the optical axis LX (for example, movement only in the one-dimensional direction). Other forms that move are also possible.

  Further, in the present embodiment, the position detection is performed by the magnetic field change, but the position detection unit is not limited to the one by the magnetic field change.

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 sensors 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, 453, 456 First, third, sixth circuit 461, 463, 466 Eleventh, thirteenth, sixteenth circuit 49a Movable substrate 50a Moving shaft 51a-53a First-first 3 Horizontal movement bearings 54b to 57b 1st to 1st Bearing part for vertical movement 64a Plate 65b Base plate 67 Shooting lens 72 Memory part A1, A2, A5, A8 First, second, fifth, eighth operational amplifiers A21, A22, A25, A28 21, 21, 22, 25th , 28th operational amplifier dx, dy first, second PWM duty hh10 horizontal hall element hv10 vertical hall element L1, L2 first, second effective length LX optical axis px, py first, second detection position signal of photographing lens vx, vy first and second angular velocities

Claims (8)

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 detection unit having a magnetic field change detection element;
When the position of the movable part is detected, voltage is applied between the input terminals of the horizontal direction magnetic field change detection element and the vertical direction magnetic field change detection element, and when the position is not detected, the voltage application is stopped ,
A first detection position signal for specifying a position in the first direction is output from the output signal of the horizontal magnetic field change detection element to detect the position of the movable part, and the movable signal is output from the output signal of the vertical magnetic field change detection element. A signal processing unit for outputting a second detection position signal for specifying a position in the second direction for detecting the position of the unit;
Control for calculating the positions of the movable part in the first and second directions after the first and second detection position signals are inputted and A / D converted, and controlling the movable part, the fixed part, and the signal processing part. Means and
When the position of the movable portion is detected, the voltage of a constant voltage value is applied from the control means via the signal processing unit, and from the control means via the signal processing unit, except during the position detection. An image blur correction apparatus that stops voltage application . When the position of the movable part is detected, voltage is applied from the control means to all the operational amplifiers in the signal processing part, and when the position is not detected, the voltage application from the control means is stopped. The image blur correction apparatus according to claim 1 , wherein the image blur correction apparatus is an image blur correction apparatus. The voltage application to all the operational amplifiers is performed prior to the voltage application to the input terminals of the horizontal magnetic field change detection element and the vertical magnetic field change detection element, respectively. 3. The image blur correction apparatus according to claim 2 , wherein the stop is performed simultaneously with the stop of the voltage application to the input terminals of the horizontal direction magnetic field change detection element and the vertical direction magnetic field change detection element. The image blur correction apparatus according to claim 1 , further comprising a memory unit connected to the control unit, recording the constant voltage value, and not erasing contents even when the power is turned off. The movable part has the magnetic field change detection part,
The image blur correction apparatus according to claim 1, wherein the magnetic field change detection unit includes one horizontal magnetic field change detection element and one vertical magnetic field change detection element. The magnetic field change detection unit is a uniaxial Hall element,
6. The image blur correction apparatus according to claim 5 , wherein both the horizontal direction magnetic field change detection element and the vertical direction magnetic field change detection element are Hall elements. The fixed portion has a position detection magnet portion used for position detection in the first and second directions of the movable portion at a position facing the magnetic field change detection portion,
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 5 , 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 image blur correction apparatus according to claim 7 , wherein the first and second position detection magnets are also used for movement of the movable portion in first and second directions.

Images