JP2015200797A - Sensor output temperature correction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly manage information for sensor output temperature correction.SOLUTION: A sensor output temperature correction device integrates outputs from gyroscopes 23X and 23Y to calculate the amount of camera shake, and drives a correction lens 14 to perform camera shake correction. The sensor output temperature correction device is provided with a temperature sensor 50, and calculates the gain GG of a linear correction formula of the outputs of the gyroscopes from the temperature and the outputs of the gyroscopes during process adjustment and the output of the temperature sensor 50 and the outputs of the gyroscopes during a camera static state. The sensor output temperature correction device records, in a flash memory 51, the gain GG calculated during the drive of a lock motor 44 of a lock mechanism 26 of a camera shake correction mechanism 13.

Description

  The present invention relates to a method for processing temperature-dependent sensor output, and more particularly to temperature correction for output of a gyro sensor mounted on a camera.

  In a camera having a camera shake correction function, for example, a gyro sensor is used to detect camera shake, and correction is performed optically or electronically so as to cancel image shake caused by the shake. However, a temperature drift (offset) generally exists in the output (angular velocity) of the gyro sensor. Therefore, if the output of the gyro sensor is integrated as it is and the angle is calculated, the deviation due to the offset component increases with time, and appropriate camera shake correction cannot be performed.

  It is also known to use a high-pass filter for removing offset due to temperature. However, in this case, it is necessary to set the passband of the filter to a higher frequency, so that signal components caused by vibrations of camera shake that should be detected are also blocked, and high-precision camera shake correction may be hindered. There is. It is also conceivable to measure the temperature characteristics of the gyro output and obtain the temperature correction formula or correction data in advance, but the temperature characteristics of the gyro output differ from sensor to sensor, so for all products before shipment, It is necessary to examine the output of each gyro at at least two different temperatures, which significantly reduces production efficiency. Because of these problems, a configuration has been proposed in which an accelerometer is mounted on a gyro-equipped electronic device so that the stationary state can be detected, so that the gyro-equipped electronic device calibrates itself after product shipment and performs temperature correction. (See Patent Document 1).

JP 2012-037405 A

  However, the camera rarely shoots in a stationary state except when shooting using a tripod. For this reason, if the temperature changes during shooting or moving, accurate correction cannot be performed using the calibration result obtained in a stationary state. Although it is conceivable to acquire and record information related to the temperature characteristics, there is a possibility that correction processing cannot be performed if information recording is not performed effectively.

  An object of the present invention is to appropriately manage information for temperature correction of sensor output.

  The sensor output temperature correction apparatus according to the present invention is a temperature correction apparatus that corrects an output from a sensor including a temperature drift, and is a stationary sensor that determines whether or not a temperature sensor, a nonvolatile memory, and a stationary state are present. A state determination unit, a temperature specifying calculation unit that calculates information related to a temperature characteristic of the temperature sensor when it is determined that it is in a stationary state, and a recording unit that records information related to the temperature characteristic in a nonvolatile memory, Recording of information related to temperature characteristics in a nonvolatile memory is performed while a drive unit mounted on a lens barrel is being driven.

  For example, the temperature correction device determines the stationary state based on the output from the sensor. The correction is performed using the output from the sensor at the reference first temperature, the second temperature detected in the stationary state, and the output from the sensor at that time. The information is preferably calculated when the difference between the first temperature and the second temperature is equal to or greater than a predetermined value. The driving unit is preferably an actuator of a camera shake correction mechanism mounted on the lens barrel or a motor for locking the camera shake correction mechanism. The temperature correction apparatus records the valid data code in the nonvolatile memory immediately after the recording of the information in the nonvolatile memory is completed.

  The lens barrel of the present invention is characterized by including the temperature correction device for sensor output as described above.

  According to the present invention, it is possible to appropriately manage information for temperature correction of sensor output.

It is a block diagram which shows typically the structure of the camera of this embodiment. It is the front perspective view of the camera-shake correction mechanism of this embodiment, the front view at the time of lock release, and the front view at the time of lock. It is a figure which shows typically the movable range of the correction | amendment lens at the time of lock release and lock. It is a perspective view which shows typically the motion of the camera by camera shake, and the relationship between an X-axis and a Y-axis. It is a front view which shows the relationship between a camera main body, a correction lens, and X and Y axes. It is a block diagram of camera shake correction control executed in the lens CPU. It is a flowchart of the main program performed with camera CPU. It is a flowchart of the main program performed with lens CPU. It is a flowchart of a 1 mS timer interrupt process executed by the lens CPU. It is a flowchart of the process test process performed with lens CPU. It is a flowchart of the 2nd correction value (VV) reset process performed with lens CPU. It is a flowchart of the tripod detection process performed by lens CPU. It is a flowchart of the center drive process performed by lens CPU. It is a flowchart of camera shake correction drive processing executed by the lens CPU. It is a flowchart of the gain data update process executed by the lens CPU. It is a schematic diagram which shows the mode of the writing of the data to the non-volatile memory in a gain data update process. It is a timing chart which shows the operation content of the camera-shake correction mechanism including the lock ring, the movement of the correction lens, and the timing of executing the gain data update process. It is a flowchart of the 1mS timer interruption process of the modification performed by lens CPU. It is a graph explaining the method of temperature correction in this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a camera equipped with a sensor output temperature correction apparatus according to a first embodiment of the present invention. In the figure, only the configuration according to the invention is schematically shown.

  In this embodiment, the camera 10 is a digital single-lens reflex camera in which the lens barrel 12 can be attached to and detached from the camera body 11, for example. In the present embodiment, a camera shake correction mechanism 13 is provided in the lens barrel 12. That is, the camera shake correction mechanism 13 including the correction lens 14 for shake correction is arranged between the imaging lenses 15A and 15B. Light incident from the imaging lens 15A is guided along the optical axis L to the imaging element 16 in the camera body 11 through the correction lens 14 and the imaging lens 15B, and forms an image.

  A camera CPU 17 and a lens CPU 18 are provided in the camera body 11 and the lens barrel 12, respectively. The camera CPU 17 is connected to a main switch 19, a photometric switch 20, and a release switch 21, and is connected to the lens CPU 18 through a plurality of electrodes of a lens mount (not shown) together with a power supply line and a ground. The camera CPU 17 performs various controls of the entire camera, and is connected to various other devices.

  The lens barrel 12 is provided with a camera shake correction switch 22 for setting on / off of camera shake correction control, and is connected to the lens CPU 18. Further, in the lens barrel 12, angular velocity sensors 23X and 23Y for detecting rotational angular velocities around the Y and X axes along the vertical axis and horizontal axis of the camera perpendicular to the optical axis L are provided, and the angular velocity sensors 23X and 23Y are provided. The signal detected at is input to the lens CPU 18. When camera shake correction control is on, the lens CPU 18 moves the correction lens 14 to cancel camera shake based on the angular velocity around each axis detected by the angular velocity sensors 23X and 23Y and lens information such as the focal length. The target position in the power X and Y axis directions is calculated.

  For example, the correction lens 14 is driven by electromagnetic interaction between a coil (not shown) provided in a movable part that holds the correction lens 14 and a yoke provided in a fixed part fixed to the lens barrel 12, to the coil. The current supply is controlled by the X direction drive control unit 24X and the Y direction drive control unit 24Y. The movable part that holds the correction lens 14 is provided with position sensors 25X and 25Y using, for example, a Hall element, and the position of the correction lens 14 is detected and fed back to the lens CPU 18. That is, the lens CPU 18 calculates the current supply amount to the coil from the target position of the correction lens 14 calculated based on the signals of the angular velocity sensors 23X and 23Y and the position of the current correction lens 14 obtained from the position sensors 25X and 25Y. And output to the X direction drive control unit 24X and the Y direction drive control unit 24Y.

  The camera shake correction mechanism 13 is provided with a mechanical lock mechanism 26, which will be described later, and a lock detection sensor 26S for detecting the locked state. The lock mechanism 26 is a mechanism for maintaining the center of the correction lens 14 on the optical axis L. The lock mechanism 26 is driven by a lock motor 44, and the lock motor 44 is controlled by a lock ring control unit 27 based on a command from the lens CPU 18. The current lock state is notified to the lens CPU 18 by the lock detection sensor 26S.

  The lens barrel 12 is provided with a temperature sensor 50. A detection signal from the temperature sensor 50 is input to the lens CPU 18, and, as will be described later, for example, a nonvolatile memory 51 such as a flash memory provided in the lens CPU 18 (FIG. 6). (See Fig. 4), the angular velocity signals (gyro output) from the angular velocity sensors 23X and 23Y can be recorded. The communication port of the lens CPU 18 and the communication port of the camera CPU 17 are connected through an electrode of the lens mount, and data communication is performed between them as will be described later.

  FIGS. 2A to 2C are external views of the camera shake correction mechanism 13 of the present embodiment. FIG. 2A is a front perspective view, and FIG. 2B is a front view when unlocking. FIG. 2 (c) is a front view when locked.

  As shown in the figure, the correction lens 14 is held at its approximate center by a movable portion 28 having an annular frame. For example, four protrusions 28P extending outward in the radial direction are provided on the outer peripheral portion of the annular frame of the movable portion 28 at substantially equal intervals along the outer periphery. An annular lock ring 30 is disposed around the annular frame of the movable portion 28 so as to surround the annular frame, and an annular clearance 29 is provided between the lock ring 30 and the annular frame.

  The inner diameter of the lock ring 30 is such that each protrusion 28P of the movable portion 28 abuts on the inner periphery of the lock ring 30 except for tolerances, and the number of recesses 30P corresponding to the protrusions 28P is formed on the inner periphery. It is formed at substantially equal intervals along. As will be described later, the concave portion 30P defines the movable range of the correction lens 14 in camera shake correction in cooperation with the protrusion 28P.

  The lock ring 30 is accommodated in a casing 31 that has a substantially cylindrical appearance, and can be rotated around the optical axis in the casing (fixed portion) 31. The rotation of the lock ring 30 is performed by, for example, a rack and pinion mechanism provided on the outer periphery of the lock ring 30. That is, a rack portion 30 </ b> R is provided on the outer peripheral portion of the lock ring 30 and meshed with a pinion 32 provided on the casing 31 side, and the pinion 32 is driven by a lock motor 44 such as a stepping motor fixed in the casing 31. The

  Further, notches 30A and 30B for detecting the locked state from the rotational position of the lock ring 30 are provided on the outer periphery of the lock ring 30, and the photo interrupter that cooperates with the notches 30A and 30B is provided in the casing 31. (Lock detection sensor) 26S is provided. That is, when the lock is released, light is detected in the photo interrupter 26S through the notch 30A as shown in FIG. 2B, and when locked, the light is detected through the notch 30B as shown in FIG. 2C.

  Further, the movable portion 28 is provided with a plurality of flat plate portions 28A extending radially outward from the annular frame, and a coil or the like for driving the movable portion 28 is mounted thereon. The front and rear of the flat plate portion 28A are supported via a bearing (not shown) in the casing 31, and movement in the optical axis direction is restricted.

  Next, the movable range of the correction lens 14 in this embodiment will be described with reference to FIGS. FIGS. 3A and 3B are diagrams schematically illustrating the movable range of the correction lens 14 when unlocked and locked.

  When the lock shown in FIG. 2B is released, the lock ring 30 is arranged so that the protrusions 28P of the movable portion 28 are positioned in the recesses 30P. At this time, the movement of the movable portion 28 is regulated by the protrusion 28P coming into contact with the side wall of the concave portion 30P, and the movable range of the correction lens 14 is a rectangular region shaded in FIG. ) 33. On the other hand, at the time of locking in FIG. 2C, the lock ring 30 is rotated clockwise from the position in FIG. 2B, and each projection 28P is brought into contact with the arcuate inner peripheral surface of the lock ring 30. . Thereby, the movement of the movable portion 28 in the vertical and horizontal directions is restricted, and the center of the correction lens 14 is fixed so as to coincide with the optical axis L.

  However, since there is a tolerance between the projection 28P and the arcuate inner peripheral surface of the lock ring 30, the correction lens 14 actually has an optical axis as shown in FIG. It can move within a circular shaded area (movable range when locked) 34 centered on L.

  With reference to FIGS. 4 to 6, the camera shake correction process of the present embodiment will be described in more detail. 4 is a perspective view schematically showing the relationship between camera movement due to camera shake and the X and Y axes, and FIG. 5 is a front view showing the relationship between the camera body 11, the correction lens 14, and the X and Y axes. is there.

  As shown in FIG. 4, in photographing with a camera, an image blur that moves in the horizontal direction (X-axis direction) from rotation (yaw) around the vertical axis (Y-axis) occurs, and rotation around the horizontal axis ( The image blur that moves in the vertical direction (Y-axis direction) occurs depending on the pitch. Therefore, the amount of shift in the X-axis direction of the correction lens 14 for canceling image blur in the X-axis direction is determined by detecting the rotational motion around the Y-axis, and the rotational motion around the X-axis is detected. A shift amount in the Y-axis direction of the correction lens 14 for canceling image blur in the Y-axis direction is determined.

  FIG. 6 is a block diagram of camera shake correction control executed in the lens CPU 18, and the correction process is executed as an interrupt process at intervals of a predetermined time (for example, 1 mS), for example.

  Analog angular velocity signals (gyro output) around the Y axis and around the X axis obtained by the gyros of the angular velocity sensors 23X and 23Y are input to the A / D ports (A / D1, A / D2) of the lens CPU 18, and A / D arithmetic units 33X and 33Y convert the signals to digital signals (gyro output) Vx and Vy. As will be described later, offset correction values Vrx, Vry and VVx, VVy for temperature correction are subtracted from the angular velocity signals Vx, Vy around the Y axis and the X axis to obtain corrected outputs Vout_x, Vout_y. The correction outputs Vout_x and Vout_y are input to the control unit 39 and to the angle calculation units 36X and 36Y. In the angle calculators 36X and 36Y, the correction outputs Vout_x and Vout_y are integrated, and the rotation angles (yaw angle θX and pitch angle θY) around the Y axis and the X axis are calculated. In the lens drive position calculation units 37X and 37Y, the correction lens 14 in the X direction and the Y direction for canceling image blur based on the lens information 38 such as the yaw angle, the pitch angle, and the focal length f stored in the memory. The drive position is calculated and input to the control unit 39.

  When the camera shake correction switch 22 input from the port 4 is in the ON state, the control unit 39 drives the drive position X in the X axis direction and the drive position Y in the Y axis direction calculated by the lens drive position calculation units 37X and 37Y. Is the target position of the correction lens 14, the drive position X, the drive position Y and the current position X of the correction lens 14, and the deviation of the current position Y are calculated, and for example, processing such as PID calculation is performed on the automatic control calculation unit 40X. , 40Y. Outputs from the automatic control calculation units 40X and 40Y are output to the X direction drive control unit 24X and the Y direction drive control unit 24Y through the ports 1 and 2, and the X direction coils 41X and Y provided in the camera shake correction mechanism 13 are output. The current supplied to the direction coil 41Y is controlled.

  The position of the movable unit 28, that is, the current position of the correction lens 14 in the X-axis and Y-axis directions is determined based on signals from the hall sensors (position sensors) 25X and 25Y, the X-direction drive control unit 24X and the Y-direction drive control unit 24Y. And is input to the lens CPU 18 through the A / D port (A / D3, A / D4) as the current X position signal and Y position signal, and the current position X as a digital signal in the A / D calculation units 43X and 43Y. The current position Y is converted and fed back as described above. Thus, when the camera shake correction switch 22 is turned on, the target drive position of the correction lens 14 is calculated based on the outputs of the angular velocity sensors 23X and 23Y, and the correction lens 14 is set to the X axis, based on the target value. Driven in the Y-axis direction.

  The lens CPU 18 drives the lock motor 44 through the lock ring control unit (driver) 27 connected to the port 3 to rotate the lock ring 30 based on the on / off state of the camera shake correction switch 22. That is, the position is switched between the unlocked position (FIG. 2B) and the locked position (FIG. 2C). Whether the lock ring 30 has reached the unlocked position or the locked position is detected by a photo interrupter (lock detection sensor) 26S.

  The flash memory 51 also has a temperature T0 at the time of process adjustment (described later) from the temperature sensor 50 inputted via the A / D port 5 of the lens CPU 18 and an offset correction value (at the time of the process adjustment corresponding to this). Information related to the temperature characteristics of the sensor such as the first correction value) Vrx, Vry, and gains GGx, GGy (described later) is recorded. Based on the data, the control unit 39 calculates offset correction values (second correction values) VVx and VVy for the current temperature.

  Next, with reference to FIG. 19, the principle of the sensor output temperature correction process of the present embodiment using the first offset correction values Vrx and Vry, the second offset correction values VVx and VVy, and the gains GGx and GGy will be described. . The temperature correction process is performed for each of the outputs from the gyros 23X and 23Y, but both are handled in the same way. Accordingly, in the description of FIG. 19, description is made using variables such as the gain GG, the gyro output V, the offset correction values Vr, VV, and the correction output Vout excluding the subscripts x and y indicating the correspondence with the gyros 23X and 23Y. To do.

  FIG. 19 is a graph showing the relationship between the temperature and the gyro output at the time of linear approximation, and the horizontal axis corresponds to the temperature and the vertical axis corresponds to the static gyro output. When linearly approximating the gyro output, two points of data are required. In this embodiment, the output V0 at the temperature T0 at the time of process adjustment (calibration) performed before shipment is used as the first data, and the second data detects that the camera is in a stationary state after shipment. Acquired when a tripod is detected (when a tripod is detected).

  Until the second data is acquired after shipment, only the first temperature T0 acquired in the process adjustment and the gyro output V0 at that time are the flash memory as the process adjustment temperature T0 and the first correction value Vr. 51. Therefore, until the second point data is acquired, the offset value (first correction value) Vr at the temperature T0 is only subtracted from the gyro output V. If the temperature deviates from T0 even after the temperature correction, the offset value is offset. The error increases.

  For example, when the temperature T1 and the output V1 are acquired as the second data after shipment, the straight line L1 can be calculated as an approximate expression of the stationary gyro output. At this time, the gyro output V (T) corresponding to the arbitrary temperature T can be expressed as V (T) to GG1 · (T−T0) + Vr, GG1 = (V1−V0) / (T1−T0), and the subsequent correction. In the processing, for an arbitrary temperature T, it can be approximated as V (t) −Vr to VV (T) = GG1 · (T−T0). As a result, the correction output Vout = V (T) −Vr−VV (T) with respect to an arbitrary temperature T becomes substantially 0 in the stationary state, and the offset of the gyro output is removed.

  However, there is an error in the normal measurement value, and the offset value may change with time. Therefore, in the present embodiment, when the stationary state is detected, the second point data is re-acquired again under certain conditions described later, and the gain GG is updated.

  For example, when the temperature T2 and the gyro output V2 are newly acquired as the second point data, the straight line L2 can be considered as an approximate expression of the stationary gyro output. However, when the temperature T2 and the output V2 are detected as the second point data, the gyro output is corrected by the correction formula using the straight line L1, so the second correction value VV2 at this time = GG1 · (T2-T0) It becomes. Here, the gain GG2 of the straight line L2 is GG2 = (Vout + VV2) / (T2-T0), and the correction formula of the gyro output V (T) by the straight line L2 is V (T) to GG2 · (T−T0) + Vr. Become. The second correction value VV (T) is then obtained as VV (T) = GG2 · (T−T0) using the new gain GG2.

  Next, the main flow executed by the camera CPU 17 and the lens CPU 18 will be described with reference to FIG. 1, FIG. 6, FIG. 7, and FIG. The flow of FIGS. 7 and 8 is started when the main switch 19 provided in the camera body 11 is turned on. Here, it is assumed that the lens barrel 12 is attached to the camera body 11.

  FIG. 7 is a flowchart on the camera CPU 17 side. In step S100, it is determined whether or not the release switch 21 is turned on. If the release switch 21 is on, communication with the lens CPU 18 is performed in step S132, a reset of a second correction value described later is requested, and the process jumps to step S118.

  On the other hand, if it is determined in step S100 that the release switch 21 is not turned on, it is determined in step S102 whether or not the photometric switch 20 is turned on. This process is repeated until the photometric switch 20 is turned on. When it is determined that the photometric switch 20 is turned on, in step S104, communication with the lens CPU 18 is performed to request resetting of the second correction value, and through. The lens CPU 18 is notified that an image is displayed.

  In steps S106 to S114, a through image is captured and displayed. That is, in step S106, AE processing is performed, and in step S108, AF processing is performed. In step S110, charge accumulation in the image sensor (CCD) 16 starts under the focus position set in step S108 and the exposure determined in step S106. Is done. In step S112, for example, field reading of the pixel signal accumulated in the image sensor (CCD) 16 is performed and output as an image signal. In step S114, the input image signal is output to a monitor (not shown) and displayed as a through image.

  Next, in step S116, it is determined whether or not the release switch 21 is turned on. If the release switch 21 is not turned on, the process jumps to step S130. On the other hand, if the release switch 21 is on, communication with the lens CPU 18 is performed in step S118 to request the start of camera shake correction processing and to notify the lens CPU 18 that the release processing is to be executed. In steps S120 to S126, a still image is taken. That is, in step S120, charge accumulation in the image sensor (CCD) 16 is started under the focus position set in step S108 and the exposure determined in step S106. In step S122, for example, all the pixels are read out from the charges accumulated in the image pickup device (CCD) 16. In step S124, the output image signal is stored in a non-volatile video memory (not shown), and in step S126, the image is displayed on a monitor (not shown).

  In step S128, communication with the lens CPU 18 is performed to request the end of camera shake correction processing. In step S130, it is determined whether or not the photometric switch 20 is turned on. If it is determined that the photometric switch 20 is turned on, the process returns to step S106. If it is determined that the photometric switch 20 is not turned on, the process returns to step S102 and the same process is repeated. The above processing is repeated until the main switch 19 of the camera body 11 is turned off or until the camera shifts to the sleep mode.

  FIG. 8 is a flowchart on the lens CPU 18 side. In steps S200 and S202, variables such as a status register (flag), a timer counter, and an offset correction value are initialized. That is, in step S200, the second correction value reset request flag KVRES (1: reset request), camera shake correction flag BRE (1: camera shake correction drive request), and process test flag TST (1: process test in progress) are initialized. In step S202, a tripod detection request flag KV (1: tripod detection requested), a lock state flag LOCK (1: unlocked state), a tripod detection flag SAN (1: tripod detected), a tripod detection time counter Tim, Initialization of the second correction values VVx and VVy (hereinafter, both are represented by VV) is performed. That is, in step S200, KVRES = 0, BRE = 0, and TST = 0 are set, and in step S202, KV = 1, LOCK = 0, SAN = 0, Tim = 0, and VV (VVx, VVy) = 0 are set. Is done.

  When initialization of variables such as the status register (flag), timer counter, and offset correction value is completed in steps S200 and S202, it is determined in step S204 whether there is a communication request from the camera CPU 17, and this determination is performed by the camera CPU 17. Is repeated until a communication request is received. When a communication request is detected from the camera CPU 17 in the lens CPU 18, whether the communication from the camera CPU 17 is a second correction value reset request (S206) or a camera shake correction start request in steps S206, S208, S210, and S212. (S208), whether it is a camera shake correction end request (S210) or a process test request (S212), is sequentially determined.

  If the notification from the camera CPU 17 is a second correction value reset request, the second correction value reset request flag KVRES is set to 1 in step S214. In the case of a camera shake correction start request, the flag BRE is set to 1 in step S216, and in the case of a camera shake correction end request, the flag BRE is set to 0 in step S218. If a process test is requested, the process test flag TST is set to 1 in step S220. When all the determinations in steps S206 to S212 are completed, the process returns to step S204, and this process is repeated until the power of the lens CPU 18 is turned off.

  Further, the lens CPU 18 generates a timer interrupt shown in the flowchart of FIG. 9 at a cycle of 1 ms. Hereinafter, the 1 ms timer interrupt processing of the present embodiment will be described with reference to FIG. 2, FIG. 6, and FIG.

  In the 1 ms timer interrupt process, in steps S300, S302, S304, S306, and S308, whether or not the second correction value reset request flag KVRES = 1 (reset of the second correction value (VV) is requested), a tripod Whether the detection request flag KV = 1 (whether a tripod detection process for detecting whether the camera is in a stationary state is requested), or whether the camera shake correction flag BRE = 1 (camera shake correction). ), Whether or not the camera shake correction flag BRE = 0 (whether stop of camera shake correction is required), or whether or not the process test flag TST = 1 (requested by the process test) Are determined sequentially. When the determination in each step of step S300 to step S306 is No, the determination of the next step is performed, and when all the determinations of step S300 to step S308 are completed, the timer interrupt process ends. On the other hand, when the determination in each step of step S300 to step S308 is Yes, the processing corresponding to each flag described below is executed, and then the flag determination in the next step in steps S300 to S308 is performed. .

  In step S300, when the second correction value reset request flag KVRES = 1 (when the reset of the second correction value (VV) is requested), in step S310, a reset process of the second correction value VV described later is performed. Done. In step S312, the second correction value reset request flag KVRES is set to 0, and the determination in step S302 is executed.

  In step S302, when the tripod detection request flag KV = 1 (when a tripod detection process for detecting whether or not the camera is stationary is requested), a tripod detection process using a gyro output described later in step S314. After executing the tripod detection process, the determination in step S304 is executed. In this process, when it is determined that the camera is in a stationary state (tripod use state), gains GGx and GGy described later are calculated and a tripod detection flag SAN is set to 1.

  If the camera shake correction flag BRE = 1 (camera shake correction drive request) in step S304, it is determined in step S316 whether the lock state flag LOCK = 0, that is, whether the camera shake correction mechanism 13 is in the locked state. Is determined. If it is not in the locked state (in the unlocked state), the camera shake correction process described later is executed in step S318, and then the determination in step S306 is executed. On the other hand, when the lock state flag LOCK = 0 (in the lock state), in step S320, a center drive process described later is executed to bring the correction lens 14 to the center of the lockable movable range 34 (FIG. 3B). In step S322, the lock ring 30 is rotated to release the lock, and in step S324, the lock state flag LOCK is set to 1 (unlock state). Thereafter, the camera shake correction process in step S318 is started, and the determination in step S306 is executed.

  If the camera shake correction flag BRE = 0 (camera shake correction stop request) in step S306, it is determined in step S320 whether the lock state flag LOCK = 1, that is, whether the camera shake correction mechanism 13 is in the unlocked state. Is determined. If it is not in the unlocked state (in the locked state), the determination in step S308 is immediately executed. On the other hand, if the lock state flag LOCK = 1 (unlocked state), the center drive process similar to that in step S320 is executed in step S326, and the lens 14 is moved in the unlocked movable range 33 (FIG. 3A). Move to the center of In step S328, driving of the lock motor 44 for rotating the lock ring 30 to lock the camera shake correction mechanism 13 is started (lock process). Then, in step S330, it is determined whether or not the tripod detection flag SAN = 1, that is, whether or not the camera is currently in a stationary state (tripod use state).

  When the tripod detection flag SAN ≠ 1 (when not in a stationary state), it is determined in step S332 whether or not the camera shake correction mechanism 13 has been locked by the lock ring 30, and the process is repeated until the lock is completed. . When the completion of the lock is confirmed, the lock state flag LOCK is set to 0 (lock state) in step S334, and the determination in step S308 is executed. On the other hand, if it is determined in step S330 that SAN = 1 (in a stationary state), a gain data update process described later is executed in step S336, and a tripod detection flag SAN is set to 0 (not in a stationary state) in step S338. After the setting, the processing from step S332 is executed. That is, if it is determined in step S306 that the camera shake correction flag BRE = 0 (camera shake correction stop request), the camera shake correction mechanism 13 is locked without executing the camera shake correction process, and the camera shake correction mechanism 13 is locked. The gain data update process S336 is executed while the lock motor 44 is being driven to lock (the lock process is in operation).

  In step S308, when the process test flag TST = 1 (process test request), a process test described later is executed in step S340. In step S342, the process test flag TST is set to 0 (no process test request), and the timer interrupt process ends. Note that the test requested by the process test flag TST = 1 (process test request) is a temperature calibration test performed in an adjustment process in a factory before shipment. That is, after shipment, the process test flag TST is always 0, and the process test is not normally performed.

  Next, the process test process executed in step S340 of FIG. 9 will be described with reference to FIGS. The temperature correction is performed for each of the gyros 23X and 23Y, and the process test is also performed independently for both gyros. However, since both are handled in the same manner, in the following description, similarly to the description of FIG. 19, the gain GG, the gyro output V, and the offset excluding the suffixes x and y indicating the correspondence with the respective gyros 23X and 23Y. Description will be made using variables such as correction values Vr, VV, correction output Vout and the like.

  In the process test process of the lens CPU 18, first, in step S400, a writing area of a gain GG (described later) in the flash memory 51 is cleared. Since it takes a predetermined time to clear the area, the lens CPU 18 waits for 50 mS in step S402, and then the first correction value Vr and the second correction value VV are set to 0 in step S404. In steps S406 and S408, the AD value (gyro output) V of the gyros 23X and 23Y and the AD value Temp of the temperature sensor 50 are acquired by the control unit 39, and the value of Vout is input in step S410.

  Here, since the offset correction values Vr and VV are set to Vr = 0 and VV = 0 in step S404, the values of Vout (= V−Vr−VV) are the gyros 23X and 23Y at this time. The AD value V itself, that is, the gyro output V0 at the temperature T0 during the process adjustment. In step S412, the value of the first correction value Vr is set to the value of the correction output Vout at this time (Vr = Vout = V0), and the process adjustment temperature T0 during the process test is the current value acquired in step S408. The temperature AD value Temp is set (T0 = Temp), and the gain GG is set to 0 (GG = 0). In step S414, the value of Vr, the value of T0, and the value of GG set in step S412 are recorded in the flash memory 51, and the process test ends.

  Next, the second correction value (VV) reset process in the lens CPU 18 executed in step S310 of FIG. 9 will be described with reference to the flowcharts of FIGS.

  In step S500, gain GG, process adjustment temperature T0, and an OK code (valid data code) described later are read from the flash memory 51. In step S502, it is determined whether the OK code is valid. As will be described later, the OK code is a code indicating whether or not the previous recording process of the gain GG in the flash memory 51 has been performed effectively, and is read from the flash memory 51 when the OK code is valid. In step S504, the value of the second correction value VV for the current temperature Temp is calculated as VV = GG · (Temp−T0) using the gain GG. On the other hand, if it is determined in step S502 that the OK code is not valid, GG is set to 0 in step S508. In step S504, the value of the second correction value VV with respect to the current temperature Temp is set to VV using GG = 0. = GG · (Temp−T0) is calculated. That is, when the OK code is invalid, VV = 0 is set. In step S506, the gain GG read from the flash memory 51 or the value of VV calculated in step S504 using GG = 0 set in step S508 is used as the second correction value VV at the current temperature Temp. The second correction value reset process is ended by setting in the control unit 39.

  Next, with reference to FIG. 12, the tripod detection process in the lens CPU 18 executed in step S314 in FIG. 9 will be described.

  In step S600, the AD value (gyro output) V of the gyros 23X and 23Y is acquired by the control unit 39, and in step S602, the AD value Temp of the temperature sensor 50 is acquired. In step S604, the values of the correction outputs Vout of the gyros 23X and 23Y are input to the control unit 39.

  In step S606, it is determined whether or not the absolute value | ΔVout | of the variation ΔVout of Vout is smaller than a predetermined value MovLvl. That is, the difference between the previous Vout value and the current Vout value is determined for each of the X and Y components. Then, it is determined whether or not both of the absolute values are smaller than the predetermined value MovLvl. If any of the X and Y components of | ΔVout | is greater than or equal to the predetermined value MovLvl, the camera is considered to be moving. Therefore, the process moves to step S618, and the value of the tripod detection time counter Tim is reset to 0. The tripod detection process ends.

  On the other hand, if it is determined in step S606 that both the X and Y components of | ΔVout | are smaller than the predetermined value MovLvl, whether or not the value of the tripod detection time counter Tim is larger than the predetermined value in step S608. Is determined. If Tim> the predetermined value is not satisfied, Tim is incremented in step S620, and the process returns to step S600. Then, the next gyro output V, the next temperature Temp, and the next Vout are sequentially acquired in steps S600 to S604, and the process is repeated until Tim> predetermined value as long as | ΔVout | <MovLvl. If | ΔVout | <MovLvl for a certain time until Tim> predetermined value, it is determined that the camera is installed on a tripod or the like and is stationary, and the process proceeds to step S610.

  In step S610, it is determined whether or not the absolute value | Vout | of the correction output Vout is larger than a predetermined value VLvl. If the correction of the gyro output V by the second correction value VV is properly performed, if it is determined in step S608 that the camera is stationary, Vout must be substantially zero. Nevertheless, if it is determined in step S610 that | Vout |> VLvl, the correction using the second correction value VV calculated using the current gain GG is considered inappropriate. Therefore, when it is determined in step S610 that | Vout |> VLvl, the tripod detection flag SAN is set to 1 in step S614, and in step S616, the current correction output Vout, the current second correction value VV, the current A new gain GG is calculated using the temperature Temp and the process adjustment temperature T0. In step S618, the value of the tripod detection time counter Tim is reset to 0, and the tripod detection process ends.

  On the other hand, if it is determined in step S610 that | Vout | is equal to or less than VLvl, in step S612, the absolute value | Temp−T0 | of the difference between the current temperature Temp and the process adjustment temperature T0 is obtained from the predetermined value GGCalc. Is also determined. When | Temp−T0 |> GGCalc is not satisfied, it is determined that the current temperature Temp is too close to the process adjustment temperature T0 and accuracy cannot be obtained even if the gain GG is calculated. For this reason, steps S614 and S616 are skipped and the process proceeds to step S618, the value of the tripod detection time counter Tim is reset to 0, and the tripod detection process ends.

  If it is determined in step S612 that | Temp−T0 |> GGCalc, as in the case of Yes in step S610, steps S614 and S616 are executed to post a new gain GG value, and then in step S618. Is executed to reset the value of the tripod detection time counter Tim to 0, and the tripod detection process is terminated.

  Next, with reference to the flowchart of FIG. 13, the center drive process in the lens CPU 18 executed in steps S320 and S326 of FIG. 9 will be described.

  The center driving process is a process of moving the correction lens 14 to the center of the movable ranges 33 and 34 (FIG. 3) in the camera shake correction mechanism 13, and in step S700, outputs to the hall sensors 25X and 25Y (FIG. 6). Based on this, the current position information of the correction lens 14 is detected. In step S702, the drive position (X, Y), which is the target position of the correction lens 14 in the control unit 39, is set to (0, 0) corresponding to the optical axis and the centers of the movable ranges 33, 34. Thereafter, in steps S704 and S706, calculation for automatic control is performed based on the current position and the target position, and based on the calculation result, the camera shake correction mechanism 13 is driven to move the correction lens 14 to the center position (0, 0). And the process ends.

  Next, with reference to the flowchart of FIG. 14, the camera shake correction process in the lens CPU 18 executed in step S318 of FIG. 9 will be described.

  In the camera shake correction process, first, in step S800, angular velocity signals around the Y and X axes are acquired from the angular velocity sensors (gyros) 23X and 23Y, and in step S802, rotation angles around the Y and X axes are calculated (angle). Arithmetic units 36X, 36Y). In step S804, drive positions X and Y are calculated from the rotation angle calculated in step S802, the focal length f of the lens, and the like (lens drive position calculation units 37X and 37Y; control unit 39). In step S806, the current position of the correction lens 14 is acquired based on the signals from the hall sensors 25X and 25Y (X and Y direction drive control units 24X and 24Y), and feedback with the drive positions X and Y in the automatic control calculation in step S808. The operation amount is calculated from the deviation of the current position (automatic control calculation units 40X and 40Y). In step S810, power is supplied to the X and Y direction coils 41X and 41Y based on the operation amount to drive the camera shake correction mechanism 13 (X and Y direction drive control units 24X and 24Y). Ends.

  Next, the gain data update process in the lens CPU 18 executed in step S336 in FIG. 9 will be described with reference to the flowchart in FIG.

  The gain data update process is a process of recording the gain GG in the flash memory 51 when the tripod detection flag SAN = 1, that is, when the gain GG is calculated in step S616 of the tripod detection process of FIG. First, in step S900, the write area of the gain GG in the flash memory 51 is cleared. Since it takes a predetermined time to clear the area, the lens CPU 18 waits for 50 mS in step S902, and then writes the gain GG calculated in step S616 to the flash memory 51 in step S904. Next, in step S906, an OK code is written to the flash memory 51, and the gain data update process ends.

  FIG. 16 schematically shows how data is written to the flash memory 51 by the gain data update process.

  As shown in FIG. 16A, in the present embodiment, three consecutive addresses (1000, 1001, and 1002 in this case) of the flash memory 51 are X-direction gain GGx, Y-direction gain GGy, and OK code data. Assigned to. At the time of rewriting, as shown in FIG. 16B, the areas corresponding to the three consecutive addresses are cleared, and all the data “00” is written. Thereafter, as shown in FIGS. 16C and 16D, writing to each memory area is successively performed in the order of the X direction gain GGx, the Y direction gain GGy, and the OK code. The OK code is “01”, for example. If the writing of the OK code is completed, data “01” is recorded at this address. However, if the power of the lens is turned off due to the lens being removed during the gain data update process, data of “00” is recorded in the area where the OK code is recorded. That is, when the OK code in step S502 of the second correction process reset process of FIG. 11 is valid is when the data read from the same area is “01”, and when it is “00” There is a possibility that the gains GGx and GGy that have been output are incorrect data.

  Next, with reference to the timing chart of FIG. 17, the timing at which the gain data update process (S336 of FIG. 9, FIG. 15) of this embodiment is executed will be described. The horizontal axis in FIG. 17 corresponds to time, FIG. 17A shows the operation content of the camera shake correction mechanism 13 (see FIG. 2) including the lock ring 30, and FIG. 17B shows the movement of the correction lens 14. This is shown schematically.

  At time t0, the lens power is turned on, and the lens CPU 18 notifies the camera CPU 17 of the second correction value reset (command (request) (S104 or S132)) at t1, and then the camera CPU 17 requests camera shake correction processing start ( (Command) (S118), the camera shake correction lens center driving process (S320) is performed between t2 and t3 substantially simultaneously, and the lock ring 30 unlocking process (S322) is performed between t3 and t4. When the lock ring 30 is released, a camera shake correction process (S318) is executed, and the correction lens 14 is swung around the center in accordance with the camera shake as shown in FIG. When the lens CPU 18 is notified of the camera shake correction end command (request) (S128) from the camera CPU 17, the center drive process (S326) is performed from t5 to t6. As soon as the center drive process ends, the lock process (S328) for locking the lock ring 30 is started, and the lock process operation ends at t7 (Yes in S332). A period TP1 for executing the gain data update process (S336) is provided between the period t6 and t7 from the start (S328) to the end.

  Since it takes a certain time to write the gain data to the memory, there is a possibility that the power of the lens CPU 18 is turned off by removing the lens barrel 12 from the camera body 11 during the writing. In that case, since the gain data is not correctly recorded in the memory, proper temperature correction cannot be performed when the next gain data is used. Therefore, in the present embodiment, the gain data update process (S336) is performed while the lock motor 44 is driven, thereby preventing the power of the lens CPU 18 from being turned off during the writing to the memory. That is, while the lock motor 44 is being driven, a normal motor noise is generated and there is some vibration, so that the possibility that the user accidentally removes the lens barrel 12 from the camera body 11 is extremely low. Therefore, in the present embodiment, gain data is written to the flash memory 51 during the synchronization. In this embodiment, since the OK code is recorded after the gain data, it is possible to determine the validity of the read gain data by referring to the OK code when reading the data. is there.

  The gain update process (S336) may be performed at other timing as long as the lens power is not turned off. For example, during the period t5 to t7 from when the center drive is started to when the lock ring is locked, the motor and actuator of the camera shake correction mechanism 13 are driven, and the user is unlikely to turn off the power. Similarly, when the gain data update process is performed during the period TP (t5 to t7) or the period from t2 to t4, the power of the lens CPU 18 is prevented from being turned off during the writing to the memory. Can do. Thereby, according to this embodiment, the information for temperature correction of a sensor output can be managed appropriately.

  FIG. 18 shows, as a modified example, a flowchart of the 1 mS timer interrupt process of the lens CPU 18 when the gain data update process is performed during the center drive process in the period TP.

  The flowchart in FIG. 18 corresponds to the flowchart in FIG. 9 and differs from FIG. 9 in the flow from step S326 to S338, and the other processes are the same as those in FIG. Therefore, in the description of this figure, only steps S346 to S358 that are replaced with steps S326 to S338 will be described.

  If it is determined in step S320 that the lock state flag LOCK = 1, the center drive process is started in step S346 as in step S326 of FIG. In the flow of FIG. 9, it is determined whether or not the tripod detection flag SAN = 1 in step S330 after the end of the center drive process. However, in the modification, as soon as the center drive process is started, the step is performed. In S348, it is determined whether or not the tripod detection flag SAN = 1.

  When the tripod detection flag SAN ≠ 1 (when not in a stationary state), it is determined in step S350 whether or not the center driving process by the camera shake correction mechanism 13 has been completed, and this process is performed until the center driving process is completed. Repeated. When the completion of the center drive process is confirmed in step S350, the lock process of the camera shake correction mechanism 13 by the lock ring 30 is executed in step S352. When the lock is completed in step S352, the lock state flag LOCK is set to 0 (lock state) in step S354, and the determination in step S308 is executed in the same manner as in FIG.

  On the other hand, if it is determined in step S348 that SAN = 1 (in a stationary state), gain data update processing is executed in step S356 in the same manner as in step S336 in FIG. 9, and in step S358, step S338 in FIG. Similarly, the tripod detection flag SAN is set to 0 (not in a stationary state). After that, the process after step S350 is performed. That is, when it is determined in step S306 that the camera shake correction flag BRE = 0 (camera shake correction stop request), the actuator is being driven to move the correction lens 14 to the center of the movable range (center drive processing). The gain data update process S356 is executed during operation).

  As described above, in the modified example, similarly to the present embodiment, it is possible to prevent the power of the lens CPU 18 from being turned off during the writing of gain data to the memory.

  In the present embodiment and the modification, the stationary state of the camera is detected using the gyro output, but other sensors such as an acceleration sensor may be mounted, and the stationary state may be detected based on these sensor outputs. In the present embodiment and the modification, data is written to the memory while the lens power is not turned off by the user, for example, while the driving unit such as the lens motor or actuator is operating. However, the present invention may be configured to perform writing to the memory when the drive unit is stopped and to determine the validity of the recorded gain by adding the OK code. In this case, invalid gain data is stored. Although the possibility of occurrence increases, the temperature correction process can be executed even when the gain data is not properly recorded.

DESCRIPTION OF SYMBOLS 10 Camera 13 Camera shake correction mechanism 14 Correction lens 16 Image sensor 17 Camera CPU
18 Lens CPU
19 Main switch 21 Release switch 22 Camera shake correction switch 23X, 23Y Angular velocity sensor 24X, 24Y Drive controller 25X, 25Y Hall sensor (position sensor)
26 Lock mechanism 26S Photo interrupter (Lock detection sensor)
28 Movable part 28P Protrusion 30 Lock ring 30A, 30B Notch 30P Recess 30R Rack part 32 Pinion 44 Lock motor 50 Temperature sensor 51 Flash memory (nonvolatile memory)

Claims (7)

A temperature correction device for correcting output from a sensor including temperature drift,
A temperature sensor;
Non-volatile memory;
A stationary state determining means for determining whether or not a stationary state;
A temperature specifying calculation means for calculating information related to a temperature characteristic of the temperature sensor when it is determined that it is in a stationary state;
Recording means for recording information on the temperature characteristics in the nonvolatile memory,
A sensor output temperature correction device, wherein information related to the temperature characteristic is recorded in the nonvolatile memory while a drive unit mounted on a lens barrel is being driven.   The temperature correction device for sensor output according to claim 1, wherein the stationary state is determined based on an output from the sensor.   The correction is performed using an output from the sensor at a reference first temperature, a second temperature detected in the stationary state, and an output from the sensor at this time. The temperature correction apparatus of the sensor output as described in any one of 1-2.   The temperature correction device for sensor output according to any one of claims 1 to 3, wherein the information is calculated when a difference between the first temperature and the second temperature is a predetermined value or more.   The temperature of the sensor output according to claim 1, wherein the drive unit is an actuator of a camera shake correction mechanism mounted on the lens barrel or a motor for locking the camera shake correction mechanism. Correction device.   The temperature correction of the sensor output according to any one of claims 1 to 5, wherein an effective data code is recorded in the nonvolatile memory immediately after the recording of the information in the nonvolatile memory is completed. apparatus.   A lens barrel comprising the sensor output temperature correction device according to claim 1.

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