JP2009180990A - Camera and interchangeable lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enlarge a detection range by a magnetic sensor, in a camera having a blur correction function. <P>SOLUTION: The camera includes: an imaging device 6 which images a subject image made incident through an image forming optical system; blur detection means 14X and 14Y which detect the blur of the camera; a blur correction unit 15 which controls the relative position between the image forming optical system 2 and the imaging device 6 in a direction orthogonal to the optical axis of the image forming optical system 2, based on the detected blur, to correct image blur on the imaging device 6; a position detection sensor 154 which has such a characteristic that a linear position detection signal in proportion to the relative position is outputted in a first area where the relative position is small and a non-linear position detection signal not being in proportion to the relative position is outputted in a second area where the relative position is large; a correction means 7 which corrects the non-linear position detection signal to a corrected position detection signal in proportion to the relative position, to output it; and a control means 7 which drive-controls the blur correction unit 15, based on either one of the position detection signal and the corrected position detection signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a camera having a blur correction function and an interchangeable lens.

2. Description of the Related Art Conventionally, a device that uses a position detection device using a magnet and a magnetic sensor as a camera shake correction device is known (for example, Patent Document 1).
JP 2000-39303 A

  However, since the output range having linearity is used for position detection among the outputs of the magnetic sensor, there is a problem that the range in which position detection is possible is limited.

According to a first aspect of the present invention, there is provided a camera according to the first aspect, wherein an image pickup device that picks up an image of a subject incident through an image forming optical system, a shake detecting unit that detects camera shake, and an image formed based on the detected shake. In a direction orthogonal to the optical axis of the optical system, a blur correction unit that corrects image blur on the image sensor by controlling the relative position between the imaging optical system and the image sensor, and a first region where the relative position is small A position detection sensor having a characteristic of outputting a linear position detection signal proportional to the relative position and outputting a nonlinear position detection signal not proportional to the relative position in the second region where the relative position is large, and the nonlinear position detection signal as the relative position Correction means for correcting and outputting a proportional correction position detection signal, and control means for driving and controlling the blur correction unit based on one of the position detection signal and the correction position detection signal. And wherein the door.
According to a second aspect of the present invention, in the camera according to the first aspect, the correction means stores a conversion table for replacing the non-linear position detection signal with a correction position detection signal proportional to the relative position. When a non-linear position detection signal is output from the sensor, a correction position detection signal is output by a conversion table.
According to a third aspect of the present invention, in the camera according to the second aspect, the conversion table outputs the output of the position detection sensor and a linear position detection signal proportional to the relative position in the first and second regions. A corrected position signal is generated by replacing the nonlinear position detection signal of the position detection sensor with the linear position detection signal of the corresponding reference position detection sensor in the second region. It is characterized by doing.
According to a fourth aspect of the present invention, in the camera according to any one of the first to third aspects, the blur correction unit includes a blur correction optical system that forms an imaging optical system, and the blur correction optical system as an optical axis. Including a support mechanism that is movably supported in a direction orthogonal to the actuator, and an actuator that drives the blur correction optical system via the support mechanism.
According to a fifth aspect of the present invention, in the camera according to any one of the first to third aspects, the blur correction unit includes a support mechanism that supports the image pickup device so as to be movable in a direction perpendicular to the optical axis, and a support mechanism. And an actuator for driving the image sensor through a mechanism.
An interchangeable lens according to a sixth aspect of the present invention is based on an imaging optical system that forms a subject image on an image sensor provided in a camera, a blur detection unit that detects camera shake, and a detected blur. , A blur correction optical system that corrects image blur on the image sensor by moving the imaging position of the subject image on the image sensor, a drive device that drives the blur correction optical system, and a first region with a small relative position Outputs a linear position detection signal proportional to the relative position, and outputs a non-linear position detection signal that is not proportional to the relative position in the second region where the relative position is large, A storage device for storing a conversion table for replacement with a corrected position detection signal proportional to the position, and a blur correction optical system by driving the drive device based on one of the position detection signal and the corrected position detection signal And a controlling means for driving and controlling.

  According to the present invention, the range in which the position of the shake correction unit can be detected can be expanded.

A camera according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1 (a), the camera body 1 is provided with a photographing lens 2, a release button 3, a power button 4, and a mode dial 5 for performing a photographing mode setting operation. As shown in FIG. 2, the photographing lens 2 includes a focus adjustment lens 2a, another imaging lens 2b, and a shake correction device 15 (FIG. 2) described later. Further, as shown in FIG. 1B, a liquid crystal monitor 17 is provided on the back surface of the camera body 1.

  FIG. 2 is a block diagram illustrating a circuit configuration of the camera according to the embodiment. The camera includes a half-push switch 3a, a full-push switch 3b, a power switch 4a, an image sensor 6, a control circuit 7, an SDRAM 8, a flash memory 9, a memory card interface 11, a liquid crystal monitor 17, a shake detection sensor 14X and 14Y, and a shake correction. A device 15 is provided.

  The imaging element 6 is configured by a CCD or CMOS image sensor provided with a plurality of photoelectric conversion elements. The imaging element 6 captures a subject image formed on the imaging surface and outputs a photoelectric conversion signal (image signal) corresponding to the brightness of the subject image to the control circuit 7.

  Based on various programs, the control circuit 7 performs a predetermined calculation using signals input from each part constituting the camera, and sends a control signal to each part of the camera to control the photographing operation. The control circuit 7 converts the image signal input from the image sensor 6 into a digital image signal, and performs various image processing on the digital image signal to generate image data. Then, the control circuit 7 performs compression processing on the generated image data by a predetermined method such as JPEG, and records it on the memory card 12 in a format such as EXIF.

  The SDRAM 8 is used to temporarily store data during or after image processing, image compression processing, and display image data creation processing. The display image data is generated by the control circuit 7 based on the image data generated by the control circuit 7 based on the output from the image sensor 6 or the image data recorded on the memory card 12. The generated display image data is stored in the SDRAM 8 by the control circuit 7. The flash memory 9 is a non-volatile memory in which various programs for the control circuit 7 to perform operations are recorded. Further, the flash memory 9 records a position information table that is referred to by the control circuit 7 during blur correction. The position information table will be described later.

  The memory card interface 11 is an interface to which the memory card 12 can be attached and detached. The memory card interface 11 is an interface circuit that writes image data to the memory card 12 and reads image data recorded on the memory card 12 based on the control of the control circuit 7. The memory card 12 is a semiconductor memory card such as a compact flash (registered trademark) or an SD card.

  The shake detection sensors 14X and 14Y are composed of, for example, a gyro sensor, and detect the shake generated in the camera body 1 at the time of photographing by dividing it into pitching and yawing of the camera. A shake amount signal representing pitching and yawing detected by the shake detection sensors 14X and 14Y is output to the control circuit 7. The control circuit 7 performs blur correction by driving a blur correction device 15 described later based on the input blur amount signal.

  The blur correction device 15 includes a shift lens 151, actuators 153X and 153Y, and position detection sensors 154X and 154Y. The subscripts X and Y correspond to the optical axis direction Y and the lateral direction X of the camera as shown in FIG. 1, but in FIG. 2, the shift lens 151, the actuators 153X and 153Y, and the position detection sensor 154X and The positional relationship of 154Y is shown for convenience. The shift lens 151 is supported by a support member (not shown) so as to be movable in a plane parallel to the imaging surface of the imaging element 6, that is, in a plane orthogonal to the optical axis. The shift lens 151 is driven in the above plane by the actuators 153X and 153Y.

  Actuators 153X and 153Y (hereinafter collectively referred to as 153) are, for example, voice coil motors having coils, magnets, and yokes. The actuator 153 generates a driving force according to the voltage applied by the control circuit 7 and moves the shift lens 151.

  The position detection sensors 154X and 154Y (hereinafter collectively referred to as 154) are, for example, magnetic sensors having a magnet 154a and a magnetic detection element (Hall element) 154b. The magnet 154 a is fixed to the shift lens 151, and the magnetic detection element 154 b is fixed to the lens barrel of the photographing lens 2. The magnetic detection element 154b outputs a voltage corresponding to the magnetic flux density received from the magnet 154a. When the relative position of the magnet 154a and the magnetic detection element 154b changes with the movement of the shift lens 151, the magnetic flux density received by the magnetic detection element 154b from the magnet 154a changes, so the output voltage of the magnetic detection element 154b also changes. This output voltage is output to the control circuit 7 as a position detection signal indicating the position information of the shift lens 151.

  As described above, the position of the shift lens 151 is detected as position information based on the position detection signal output from the position detection sensor 154. Since the output characteristics of the position detection sensor 154 have nonlinear regions at both ends of the detection range, in this embodiment, a position information table for correcting the output voltage in the nonlinear region is mounted in each camera in advance. This position information table is created for each camera by the information table creation device 30 shown in FIG. 3 in the camera manufacturing process, and is recorded in the flash memory 9 of the camera. The position information table is a correction data table in which the output voltage of the magnetic detection element 154b is associated with the position information of the shift lens 151, as will be described later. The control circuit 7 refers to the position information table recorded in the flash memory 9, corrects the position information indicated by the input position detection signal, and accurately detects the position of the shift lens 151. By using the position information table, the non-linear output range of the magnetic detection element 154b can also be used for position detection of the shift lens 151.

First, the principle of creating the position information table created by the information table creating apparatus 30 will be described.
In this embodiment, the movement amount of the shift lens is detected by both the position detection sensor 154 and the two-dimensional PSD. FIG. 4 shows the relationship between the Hall element output and the PSD output with respect to the shift lens moving amount. The horizontal axis is the X-axis movement amount of the shift lens, the vertical axis is the Hall element output and the PSD output, the symbol VH is the Hall element output diagram, and the symbol VP is the PSD output diagram. Here, description will be made assuming that the X-axis movement amount of the shift lens 151 with respect to the drive voltage applied to the actuator 153X is linear.

In FIG. 4, the output of the position detection sensor and the PSD output when the applied voltage of the movement amount + X1 is applied to the actuator 153X are expressed as VHx1 and VPx1, respectively. Similarly, the output of the position detection sensor and the PSD output with respect to the movement amount + Xn are expressed as VHxn and VPxn, respectively. As shown in FIG. 4, the PSD output is linear throughout the lens movement region, but the position detection sensor output is nonlinear in the end region exceeding the movement amount Xh. In the non-linear region, the position of the shift lens cannot be detected correctly using the position detection sensor output. Therefore, in the non-linear region, the position information by the position detection sensor output is corrected by associating the PSD output with respect to the movement amount X and the position detection sensor output.
In the following description, it is assumed that the outputs of the position detection sensor 154 and the two-dimensional PSD are the same with respect to the shift lens movement amount.

  The creation of the position information table will be described in more detail with reference to FIGS. FIG. 3 is a block diagram of the position information table creation device. The information table creation device 30 includes a lens driving unit 31, a two-dimensional PSD (Position Sensitive Detector) 32, a control circuit 33, and a laser light output unit 34, and is configured so that the photographing lens 2 having the blur correction device 15 can be attached. ing. In the information table creation device 30, the laser beam output from the laser beam output unit 34 is irradiated perpendicularly to the light receiving surface of the two-dimensional PSD 32. When the two-dimensional PSD 32 is irradiated with the laser beam, the two-dimensional PSD 32 outputs a position detection signal indicating the position irradiated with the laser beam to the control circuit 33 as position information. Further, when the photographing lens 2 is attached to the information table creation device 30, the lens driving unit 31 and the control circuit 33 are configured to be connected to each signal output terminal of the shake correction device 15.

  The control circuit 33 makes the shift lens 151 of the blur correction device 15 to the lens driving unit 31 in two axes orthogonal to each other in a plane orthogonal to the optical axis of the laser beam output from the laser beam output unit 34, that is, Command signals for driving in the X-axis direction and the Y-axis direction shown in FIG. In response to this command signal, the lens driving unit 31 applies a driving voltage to the actuator 153 of the blur correction device 15 to drive the shift lens 151. FIG. 5 shows the shift lens 151 from the left end (X = −L) to the right end (X = L) of the drive range in the X axis direction with the Y axis direction of the shift lens 151 fixed at the center of the drive range. It shows how it is driven.

  As shown in FIG. 5A, when the shift lens 151 is driven to the right end (X = −L) of the driving range, the control circuit 33 instructs the laser light output unit 34 to output laser light. Output a signal. Upon receiving this command signal, the laser beam output from the laser beam output unit 34 enters the two-dimensional PSD 32 via the shift lens 151. At this time, the control circuit 33 inputs the position detection signal (output voltage) from the two-dimensional PSD 32 as the lens position information b1. Further, a position detection signal (output voltage) from the magnetic detection element 154b of the position detection sensor 154 is input as the lens position information a1.

  When the lens position information a1 and the lens position information b1 are input as described above, the control circuit 33 calculates the difference between the lens position information a1 and b1. When the calculated difference is zero, that is, when the position detection signal by the magnetic detection element 154b matches the position detection signal by the two-dimensional PSD 32, the control circuit 33 sets 1 to the linear flag. When the calculated difference is not zero, that is, when the lens position information a1 by the magnetic detection element 154b does not match the lens position information b1 by the two-dimensional PSD 32, the control circuit 33 sets 0 to the linear flag. The linear flag may be set to 1 when the calculated difference is less than a predetermined threshold, and the linear flag may be set to 0 when the difference is greater than or equal to the predetermined threshold. The control circuit 33 records the lens position information a1, the lens position information b1, and the linear flag in association with each other.

  Next, as shown in FIG. 5B, the control circuit 33 drives the shift lens 151 by a distance ΔL in the X-axis direction. When the shift lens 151 is driven by the distance ΔL and positioned at (X = −L + ΔL), the control circuit 33 performs lens position information a2 by the magnetic detection element 154b and lens position information by the two-dimensional PSD 32 in the same manner as described above. b2 is acquired and the linear flag is set. Then, the control circuit 33 records the lens position information a2, the lens position information b2, and the linear flag in association with each other.

  As described above, the control circuit 33 drives the shift lens 151 by a distance ΔL in the X-axis direction, and repeats the recording of the lens position information and the linear flag acquired at the post-drive position, as shown in FIG. As shown in FIG. 4, the shift lens 151 is driven to the right end (X = L) of the driving range. When the shift lens 151 is driven to the right end, the control circuit 33 creates a position information table related to the X-axis direction using the lens position information and the linear flag recorded for each distance ΔL.

  FIG. 6 shows an example of the position information table in the X-axis direction. This position information table indicates that the linear flag is 0 near the end of the driving range of the shift lens 151, that is, the lens position information obtained from the magnetic detection element 154b is different from the lens position information obtained from the two-dimensional PSD 32. ing. Further, in the vicinity of the center portion (X = 0) of the driving range of the shift lens 151, the linear flag is 1, that is, the lens position information obtained from the magnetic detection element 154b and the lens position information obtained from the two-dimensional PSD 32 are equal. Represents. That is, the output voltage of the magnetic detection element 154b and the output voltage of the two-dimensional PSD 32 with respect to the position of the shift lens 151 have characteristics as shown in FIG. In FIG. 7A, the solid line P1 indicates the characteristic of the output voltage from the magnetic detection element 154b, and the broken line P2 indicates the characteristic of the output voltage from the two-dimensional PSD 32. 7A shows the output voltage when the center of the magnet 154a and the center of the magnetic detection element 154b are coincident at the points X = 0 and Y = 0, as shown in FIG. 7B. This shows the characteristics.

  As shown in FIG. 7A, in the region R2 (for example, 0.3 mm) near the center portion (X = 0) of the driving range of the shift lens 151, the output voltage of the magnetic detection element 154b and the two-dimensional PSD 32 Both the output voltage and the output voltage are linear. In the region R1 or region R3 where the shift lens 151 is near the end of the driving range (X = -L or X = L), the output voltage of the two-dimensional PSD 32 continues to maintain linearity, but the magnetic detection element 154b The output voltage becomes non-linear. Therefore, the output voltage of the two-dimensional PSD 32 represented by the broken line P2 is the same as the magnetic detection element 154b when the output voltage of the magnetic detection element 154b represented by the solid line P1 does not lose linearity in the regions R1 and R3. It can be considered that it shows the output characteristics. The position information table is used to give linearity to the position detection characteristics of the shift lens 151 even when the output voltage of the magnetic detection element 154b is in the regions R1 and R3.

  When the creation of the position information table in the X-axis direction is completed, the control circuit 33 creates a position information table in the Y-axis direction. In this case, the control circuit 33 fixes the X axis direction of the shift lens 151 at the center of the driving range, and extends from the lower end (Y = −L) to the upper end (Y = L) of the driving range in the Y axis direction. Drive every distance ΔL. Then, similarly to the case of driving in the X-axis direction described above, the control circuit 33 records the lens position information and the linear flag for each distance ΔL, and creates a position information table in the Y-axis direction.

  With reference to the flowcharts shown in FIGS. 8 and 9, the above-described position information table creation processing by the information table creation device 30 will be described. Each process of FIG. 8 and FIG. 9 is performed by executing a program in the control circuit 33. 8 and 9 is stored in a memory (not shown), and is activated when an operation member (not shown) is operated and a signal instructing creation of a position information table is input.

  In step S101 of FIG. 8, the lens driving unit 31 is instructed to drive the shift lens 151 to the left end (X = −L) of the driving range in a state where the Y-axis direction of the shift lens 151 is fixed at the center of the driving range. Proceed to step S102. In step S102, a process for acquiring lens position information is performed, and the process proceeds to step S103. The lens position information acquisition process will be described later with reference to FIG.

  In step S103, the lens driving unit 31 is instructed to move the shift lens 151 by a distance ΔL in the X axis direction of the driving range, and the process proceeds to step S104. The process in step S104 is the same as that in step S102. In step S105, it is determined whether or not the shift lens 151 has reached the right end (X = L) of the drive range. When the position of the shift lens 151 has reached the right end of the drive range, an affirmative determination is made in step S105 and the process proceeds to step S106. If the position of the shift lens 151 has not reached the right end of the driving range, a negative determination is made in step S105 and the process returns to step S103.

  In step S106, a position information table in the X-axis direction is created using the lens position information acquired in steps S102 and S104, recorded in a predetermined recording area, and the process proceeds to step S107. In step S107, the lens drive unit 31 is instructed to drive the shift lens 151 to the lower end (Y = −L) of the drive range with the X-axis direction of the shift lens 151 being fixed at the center of the drive range, and then to step S108. move on.

  The process in step S108 is the same as that in step S102. In step S109, the lens driving unit 31 is instructed to move the shift lens 151 by a distance ΔL in the Y axis direction of the driving range, and the process proceeds to step S110. The process in step S110 is the same as that in step S102. In step S111, it is determined whether or not the shift lens 151 has reached the upper end (Y = L) of the drive range. When the position of the shift lens 151 has reached the upper end of the drive range, an affirmative determination is made in step S111 and the process proceeds to step S112. If the position of the shift lens 151 has not reached the upper end of the driving range, a negative determination is made in step S1111 and the process returns to step S109.

  In step S112, a position information table in the Y-axis direction is created using the lens position information acquired in steps S108 and S110, recorded in a predetermined recording area, and a series of processes is completed.

With reference to FIG. 9, the lens position information acquisition processing in steps S102, S104, S108, and S110 of FIG. 8 will be described.
In step S201, lens position information am (1 ≦ m ≦ n) is acquired based on the output voltage from the magnetic detection element 154b of the position detection sensor 154, and the process proceeds to step S202. In step S202, lens position information bm (1 ≦ m ≦ n) is acquired based on the output voltage from the two-dimensional PSD 32, and the process proceeds to step S203.

  In step S203, it is determined whether the lens position information am acquired in step S201 is equal to the lens position information bm acquired in step S202. If the lens position information am and bm are equal, step S203 is affirmed and the process proceeds to step S204. In step S204, the linear flag is set to 1 and the process proceeds to step S206. If the lens position information am and bm are not equal, a negative determination is made in step S204 and the process proceeds to step S205. In step S205, the linear flag is set to 0 and the process proceeds to step S206.

  In step S206, the lens position information am, the lens position information bm, and the linear flag set in step S204 or step S205 are associated with each other and recorded in a predetermined recording area.

  The position information table created as described above is recorded in the flash memory 9 of the camera body 1. In the camera body 1, when the user sets the shooting mode, the control circuit 7 controls the shake correction device 15 to start the shake correction operation. The control circuit 7 inputs the shake amount signal output from the shake detection sensors 14X and 14Y and the position detection signal output from the position detection sensor 154.

  Whenever the position detection signal from the position detection sensor 154 is input, the control circuit 7 refers to the position information table and corresponds to the lens position information am (1 ≦ m ≦ n) indicated by the input position detection signal. The position information bm (1 ≦ m ≦ n) is read. Then, the control circuit 7 determines the read lens position information bm as the position of the shift lens 151. That is, the control circuit 7 replaces the lens position information am with the lens position information bm.

  The control circuit 7 drives the shift lens 151 for correcting the above-described image blur based on the blur amount signals output from the blur detection sensors 14X and 14Y and the position of the shift lens 151 determined as described above. Calculate the amount. Then, the control circuit 7 applies a voltage to the actuator 153 based on the calculated drive amount.

  The actuator 153 generates a driving force by the applied voltage and drives the shift lens 151 in a plane orthogonal to the optical axis. As a result, the relative position of the shift lens 151 and the image sensor 6 in the direction orthogonal to the optical axis of the subject light is changed, and the subject light that has passed through the photographing lens 2 is refracted in a direction that cancels out the blur. Can be resolved.

  The control circuit 7 updates the image displayed on the liquid crystal monitor 17 with a period of 1/30 seconds, for example, by controlling the image sensor 6 and the LCD drive circuit 171. As a result, the moving image is displayed on the liquid crystal monitor 17 as a through image. At this time, since the image blur is eliminated by the shift lens 151, a live view without blur is displayed on the liquid crystal monitor 17.

  When the user half-presses the release button 3 to instruct preparation for shooting, the control circuit 7 reads the image signal output from the image sensor 6 and calculates, for example, a focus evaluation value. The control circuit 7 adjusts the focus adjustment state by driving the focus adjustment lens 2a based on the calculation result.

  When the release button 3 is fully pressed, the control circuit 7 determines the position of the shift lens 151 with reference to the position information table based on the position detection signal from the position detection sensor 154. When the position of the shift lens 151 is determined, the control circuit 7 applies a voltage necessary for driving the shift lens 151 to the initial position, that is, a voltage necessary for centering, to the actuator 153. The initial position is a position where the optical axis of the shift lens 151 coincides with the optical axis of the photographing lens 2. In this manner, the control circuit 7 applies a voltage to the actuator 153 until it is determined that the shift lens 151 has moved to the initial position based on the position detection signal input from the position detection sensor 154 and the position information table. As a result, the shift lens 151 is centered at the initial position. When the control circuit 7 confirms that the shift lens 151 has been centered, the control circuit 7 controls the image sensor 6 to start imaging. Further, as described above, the control circuit 7 shifts the shift lens 151 based on the shake amount signals output from the shake detection sensors 14X and 14Y, the position detection signal output from the position detection sensor 154, and the position information table. Directs the shake correction to drive.

  The image signal output from the image sensor 6 is subjected to the above-described processing by the control circuit 7 to generate image data. Next, the control circuit 7 executes a compression process on the generated image data. Then, the control circuit 7 generates an image file based on the compressed image data and writes the image file to the recording medium 12.

  The operation of the camera according to the embodiment will be described with reference to the flowcharts shown in FIGS. Each process of FIG. 10 and FIG. 11 is performed by executing a program in the control circuit 7. A program for performing each process of FIGS. 10 and 11 is stored in the flash memory 9 and is activated when a signal instructing setting of the photographing mode is input from the mode dial 5.

  In step S301, the LCD drive circuit 171 is instructed to turn on the liquid crystal monitor 17, and the process proceeds to step S302. In step S302, the blur correction device 15 is driven to perform blur correction processing, and the process proceeds to step S303. The blur correction process will be described later with reference to FIG. In step S303, the through image is displayed on the liquid crystal monitor 17 based on the image signal output from the image sensor 6, and the process proceeds to step S304.

  In step S304, it is determined whether or not the release button 3 has been pressed halfway. If an ON signal is input from the half-press switch 3a, an affirmative determination is made in step S304 and the process proceeds to step S305. If no ON signal is input from the half-press switch 3a, a negative determination is made in step S304 and the process returns to step S302.

  The processing in step S305 is the same as that in step S302. In step S306, the focus evaluation value is calculated, and the focus adjustment lens 2a is driven based on the calculation result to adjust the focus, and the process proceeds to step S307. In step S307, it is determined whether or not the release button 3 has been fully pressed. When an ON signal is input from the full push switch 3b, an affirmative determination is made in step S307 and the process proceeds to step S308. When the ON signal is not input from the full push switch 3b, a negative determination is made in step S307, and the process proceeds to step S312 described later.

  In step S308, centering for driving the shift lens 151 to the initial position is performed, and the process proceeds to step S309. The processing in step S309 is the same as that in steps S302 and S305. In step S310, a photographing operation is performed, the acquired image data is recorded in the memory card 12, and the process proceeds to step S311. In step S311, it is determined whether the power is turned off. When an off signal is input from the power switch 4a, an affirmative determination is made in step S301, and the series of processing ends. If no off signal is input from the power switch 4a, a negative determination is made in step S311 and the process returns to step S302.

  If an ON signal is not input from the full-press switch 3b in step S307, the process proceeds to step S312 to determine whether or not the half-press operation of the release button 3 has been released. When the half-press operation is released, that is, when an ON signal is not input from the half-press switch 3a, an affirmative determination is made in step S312 and the process proceeds to step S311. If the half-press operation is not released and an ON signal is input, a negative determination is made in step S312 and the process returns to step S305.

With reference to FIG. 11, the blur correction process in steps S302, S305, and S309 in FIG. 10 will be described.
In step S401 of FIG. 11, a blur amount signal is input from the blur detection sensors 14X and 14Y, and the process proceeds to step S402. In step S402, the lens position information am is acquired based on the output voltage from the magnetic detection element 154b of the position detection sensor 154, and the process proceeds to step S403.

  In step S <b> 403, the lens position information bm corresponding to the lens position information am acquired in step S <b> 402 is read with reference to the position information table recorded in the flash memory 9, and the read lens position information bm is read from the shift lens 151. The position information is determined and the process proceeds to step S404. In step S404, the drive amount of the shift lens 151 is calculated based on the blur amount signal acquired in step S401 and the position information of the shift lens 151 determined in step S403. Based on the calculated driving amount, a voltage is applied to the actuator 153 to drive the shift lens 151.

According to the embodiment described above, the following operational effects can be obtained.
The control circuit 7 uses the position information table to convert the output voltage of the position detection sensor 154 with respect to the shift lens movement amount so as to have linearity. That is, the position of the shift lens 151 is detected in regions corresponding to the regions R1 to R3 shown in FIG. In the conventional technique, the range in which the output voltage of the magnetic detection element 154b has linearity, that is, the range corresponding to the region R2 in FIG. 7A (for example, about 0.3 mm) is the shift lens 151 by the position detection sensor 154. It was in the range where position detection of was possible. On the other hand, according to the present embodiment, the control circuit 7 can use the position information table as a range in which the position of the shift lens 151 can be detected for the region R1 and the region R3. The position detection range of the lens 151 can be expanded.

  As shown in FIG. 12, when the center of the magnet 154a and the center of the magnetic detection element 154b do not coincide with each other at the points X = 0 and Y = 0, the region having linearity in the output voltage of the magnetic detection element 154b R2 is offset by the amount of deviation between the center of the magnet 154a and the center of the magnetic detection element 154b as compared to the case shown in FIG. In this case, in the conventional technique, a region that can be used for detecting the position of the shift lens 151 in the positive direction of the X-axis is a region R21 in FIG. In other words, the region that can be used for detecting the position of the shift lens 151 in the X-axis direction is the region R21 and the region R22 having the same range as the region R21. The range becomes narrower. On the other hand, according to the present embodiment, since the region R31 can be used for position detection of the shift lens 151 using the position information table, the position detection range of the shift lens 151 can be ensured. Furthermore, it is possible to reduce the design burden that it is necessary to reduce the deviation between the centers of the magnet 154a and the magnetic detection element 154b as much as possible in order to secure the areas 21 and R22.

  Furthermore, considering the case where the centers of the magnet 154a and the magnetic detection element 154b are displaced as described above, it is necessary to provide a margin in the drive range when determining the drive range of the shift lens 151. However, by using the position information table, it is not necessary to provide a margin in the driving range of the shift lens 151, so that the driving range of the shift lens 151 can be set wide. As a result, it is possible to perform blur correction corresponding to a large blur occurring in the camera.

The embodiment described above can be modified as follows.
(1) According to the value set in the linear flag, the control circuit 7 uses the position detection signal input from the position detection sensor 154 as the lens position information of the shift lens 151 and the lens position information bm in the position information table. May be switched between using the lens position information as the lens position information of the shift lens 151. In this case, when the position detection signal from the position detection sensor 154 is input, the control circuit 7 refers to the position information table and sets the value set in the linear flag corresponding to the lens position information indicated by the input position detection signal. Determine. For example, when the input lens position information is a (n / 2), the control circuit 7 refers to the position information table in FIG. 6 and determines that the linear flag is 1. When the linear flag is 1, the control circuit 7 uses the lens position information a (n / 2) indicated by the position detection signal input from the position detection sensor 154 as the lens position information of the shift lens 151.

  When the input lens position information is a2, the control circuit 7 refers to the position information table and determines that the linear flag is 0. When the linear flag is 0, the control circuit 7 uses the lens position information b2 by the two-dimensional PSD 32 corresponding to the lens position information a2 indicated by the input position detection signal as the lens position information of the shift lens 151.

(2) Instead of replacing the nonlinear output with the linear output, the control circuit 7 may correct the lens position information am indicated by the input position detection signal. In this case, for example, a difference value cm (= bm−am) between the lens position information am and the lens position information bm is recorded in the flash memory 9 in advance as correction data. When the position detection signal is input from the position detection sensor 154, the control circuit 7 refers to the correction data and reads the difference value cm corresponding to the lens position information am indicated by the input position detection signal. Then, the control circuit 7 may correct the lens position information of the shift lens 151 by adding the difference value cm to the lens position information am.

(3) The shake correction device 15 may be provided inside the interchangeable lens. In this case, the blur correction device 15 includes a memory for recording the position information table and a control circuit for converting the lens position information am input from the position detection sensor 154 into the lens position information bm. Good.

(4) Instead of driving the shift lens 151 to perform blur correction, the blur correction may be performed by driving the image sensor 6. In this case, the imaging element 6 is supported by a support member so as to be movable in a direction orthogonal to the optical axis, and is driven by the actuator via the support member.

  In addition, the present invention is not limited to the above-described embodiment as long as the characteristics of the present invention are not impaired, and other forms conceivable within the scope of the technical idea of the present invention are also within the scope of the present invention. included.

1 is an external view of a camera according to an embodiment of the present invention. Main part configuration diagram of camera according to embodiment Configuration diagram of main parts of an output correction apparatus according to an embodiment Diagram explaining the relationship between Hall element output and PSD output The figure which shows the drive of the shift lens at the time of position information table creation The figure explaining an example of a positional information table The figure explaining the output characteristic of a magnetic detection element Flowchart for explaining position information table creation processing in the embodiment Flowchart for explaining position information table creation processing in the embodiment Flowchart for explaining the operation of the camera of the embodiment Flowchart for explaining the operation of the camera of the embodiment The figure explaining the output characteristic of a magnetic detection element

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Shooting lens 6 ... Imaging element 7 ... Control circuit 9 ... Flash memory 14X, 14Y ... Blur detection sensor 15 ... Blur correction device 151 ... Shift lens 153 ... Actuator 154 ... Position detection sensor

Claims (6)

An image sensor that captures an image of a subject incident through an imaging optical system;
Blur detection means for detecting camera shake,
Based on the detected blur, in the direction perpendicular to the optical axis of the imaging optical system, the relative position between the imaging optical system and the image sensor is controlled to correct image blur on the image sensor. An image stabilization unit to
In the first region where the relative position is small, a linear position detection signal proportional to the relative position is output, and in the second region where the relative position is large, a nonlinear position detection signal which is not proportional to the relative position is output. A position detection sensor;
Correction means for correcting and outputting the nonlinear position detection signal to a correction position detection signal proportional to the relative position;
A camera comprising: control means for driving and controlling the shake correction unit based on one of the position detection signal and the corrected position detection signal. The camera of claim 1,
The correction means stores a conversion table for replacing the nonlinear position detection signal with the corrected position detection signal proportional to the relative position, and when the nonlinear position detection signal is output from the position detection sensor, The correction position detection signal is output by the conversion table. The camera according to claim 2,
The conversion table is created using both the output of the position detection sensor and the output of a reference position detection sensor having a characteristic of outputting a linear position detection signal proportional to the relative position in the first and second regions. In the second area, the corrected position signal obtained by replacing the nonlinear position detection signal of the position detection sensor with the linear position detection signal of the corresponding reference position detection sensor is output. The camera according to any one of claims 1 to 3,
The blur correction unit includes a blur correction optical system that constitutes the imaging optical system, a support mechanism that supports the blur correction optical system so as to be movable in a direction orthogonal to the optical axis, and the support mechanism via the support mechanism. And an actuator for driving the blur correction optical system. The camera according to any one of claims 1 to 3,
The camera is characterized in that the blur correction unit includes a support mechanism that supports the image sensor so as to be movable in a direction orthogonal to the optical axis, and an actuator that drives the image sensor via the support mechanism. An imaging optical system for forming a subject image on an image sensor provided in the camera;
Blur detection means for detecting camera shake,
Based on the detected blur, a blur correction optical system that corrects an image blur on the image sensor by moving an imaging position of a subject image on the image sensor;
A driving device for driving the blur correction optical system;
In the first region where the relative position is small, a linear position detection signal proportional to the relative position is output, and in the second region where the relative position is large, a nonlinear position detection signal which is not proportional to the relative position is output. A position detection sensor;
A storage device for storing a conversion table for replacing the nonlinear position detection signal with the correction position detection signal proportional to the relative position;
An interchangeable lens comprising: control means for driving and controlling the blur correction optical system by driving the drive device based on one of the position detection signal and the correction position detection signal.

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