JP2016226052A - Signal processor, lens control device and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal processor capable of appropriately dealing with panning or tilting.SOLUTION: The signal processor is provided in an imaging apparatus including a sensor for detecting a shake amount or a movable component for shake correction and generates a signal representing a target position of the movable component for shake correction based on a detection signal of the sensor. The signal processor comprises: a high-pass filter that is configured to apply high-pass filtering processing to the detection signal and formed to hold an intermediate value of arithmetic operation of the filtering processing; a saving register used for saving the intermediate value; and a save control part for saving the intermediate value in the saving register if a level of an integration value of the detection signal exceeds a predetermined first threshold, and substituting the intermediate value with a value being saved in the saving register if a predetermined condition is satisfied.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a signal processing device that performs predetermined signal processing, and a lens control device and an imaging device that include the signal processing device.

  2. Description of the Related Art Conventionally, an imaging device that performs camera shake correction using a movable lens has been used. In such an imaging apparatus, a target position signal representing a target position of the lens is generated based on a detection signal of a sensor (for example, a gyro sensor) that detects a shake amount.

  The target position is a lens position at which blurring of a captured image due to camera shake is suppressed. Then, camera shake correction is realized by controlling the lens position so that the difference between the target position signal and the current position signal (a signal representing the current position of the lens) is reduced.

JP 2011-023987 A JP 2008-134426 A

  By the way, when using the imaging apparatus, panning and tilting may be performed by a photographer. Panning and tilting move much more than camera shake, and are different from unintentional camera shake in that the photographer intentionally moves the imaging device.

  Therefore, it is desired that the imaging apparatus can appropriately cope with panning and tilting with respect to generation of a target position signal and the like. As an example, when panning or tilting is performed, it is desired that the lens easily returns to the center. Patent Document 1 discloses an imaging apparatus that increases the cutoff frequency of the high-pass filter as the fluctuation correction amount increases. However, it is not possible to restore the cutoff frequency to the original value or to perform an intermediate operation performed by the high-pass filter. There is no mention of saving values.

  In view of the problems described above, the present invention is a signal processing device that generates a target position signal based on a detection signal of a sensor that detects a shake amount, and is a signal that can appropriately cope with panning, tilting, and the like. An object is to provide a processing apparatus. It is another object of the present invention to provide a lens control device and an imaging device provided with the signal processing device.

  A signal processing apparatus according to the present invention is provided in an imaging device having a sensor for detecting a shake amount and a movable part for shake correction, and represents a target position of the movable part for shake correction based on a detection signal of the sensor. A signal processing device for generating a signal, which performs high-pass filter processing on the detection signal, and is configured to hold an intermediate value of an operation of the filter processing, and the intermediate The saving register used for saving the value and the intermediate value is saved in the saving register when the level of the integrated value of the detection signal exceeds a predetermined first threshold, and when the predetermined condition is satisfied, the intermediate value is saved. And a save control unit that replaces the value with the value saved in the save register. According to this configuration, it is possible to appropriately cope with panning, tilting, and the like.

  The signal processing device according to the present invention is provided in an imaging device having a sensor for detecting a shake amount and a movable component for shake correction, and determines a target position of the movable component for shake correction based on a detection signal of the sensor. A signal processing device that generates a signal representing the high-pass filter that performs high-pass filtering on the detection signal and is configured to hold an intermediate value of the calculation of the filtering, When the level of the save register used for saving the intermediate value and the integral value of the detection signal is continuously below a predetermined first threshold value for a predetermined time, the intermediate value is saved in the save register, and the predetermined condition is And a saving control unit that replaces the intermediate value with a value saved in the saving register when the value is satisfied. According to this configuration, it is possible to appropriately cope with panning, tilting, and the like.

  More specifically, the above-described configuration includes a first integrator that has a variable cutoff frequency and executes integration processing of the detection signal, and a second integrator that executes integration processing of the detection signal. The cutoff frequency of the first integrator may be increased when the signal level of the output signal of the second integrator exceeds a predetermined reference threshold.

  More specifically, in the above configuration, when the cut-off frequency of the first integrator is increased, the cut-off of the first integrator is continued when the signal level does not exceed the reference threshold continuously for a certain period of time. It is good also as a structure which returns a frequency.

  More specifically, the high-pass filter has a low-pass filter of a primary IIR filter to which the input value of the high-pass filter is input, and subtracts the output value of the low-pass filter from the input value of the high-pass filter. The low-pass filter is provided with a delay element that holds the output value of the low-pass filter, and the intermediate value is a value that is held by the delay element. It is good also as a structure.

  More specifically, as the above configuration, the retraction control unit, when the sign of the output of the high-pass filter is inverted after the level of the integral value of the detection signal exceeds a second threshold value higher than the first threshold value, When the offset value is replaced with a value saved in the save register, the level of the integrated value of the detection signal does not exceed a second threshold value, and the sign of the output of the high-pass filter is inverted, the substitution is performed. It is good also as a structure which does not perform.

  More specifically, the target position may be a position of the lens at which blurring of a captured image due to shake of the imaging device is suppressed. More specifically, the sensor may be a gyro sensor. More specifically, the shake correction movable part may be a movable lens.

  The lens control device according to the present invention includes the signal processing device configured as described above, and controls the position of the lens so as to approach the target position based on a signal representing the target position generated by the signal processing device. The configuration is as follows.

  More specifically, as the above configuration, a current position signal that represents the current position of the lens is acquired, and the position of the lens is controlled so that the difference between the current position signal and the signal that represents the target position is reduced. It is good also as composition to do. More specifically, the above-described configuration may be configured such that the position of the lens is controlled through control of a lens driving motor that drives the lens.

  The imaging apparatus according to the present invention includes the signal processing device having the above-described configuration. The imaging device according to the present invention includes the lens control device having the above configuration.

  The signal processing device according to the present invention can appropriately cope with panning, tilting, and the like. Further, according to the lens control device or the imaging device according to the present invention, it is possible to enjoy the advantages of the signal processing device according to the present invention.

1 is a block diagram of an imaging apparatus according to an embodiment of the present invention. It is a block diagram of the sensor detection signal processing part concerning a 1st embodiment. It is a block diagram of the high pass filter which concerns on embodiment of this invention. It is a block diagram of a sensor detection signal processing part concerning a 2nd embodiment. It is a block diagram of a sensor detection signal processing part concerning a 3rd embodiment. It is explanatory drawing regarding the operation | movement form of a sensor detection signal process part. It is explanatory drawing regarding the operation | movement form of a sensor detection signal process part. It is explanatory drawing regarding the operation | movement form of a sensor detection signal process part. It is a graph regarding a motion of a lens. It is a graph regarding a motion of a lens. It is a graph regarding a motion of a lens. It is a block diagram of a sensor detection signal processing part concerning a 5th embodiment. It is explanatory drawing regarding the operation | movement form of a sensor detection signal process part. It is a graph regarding a motion of a lens. It is a graph regarding a motion of a lens. It is explanatory drawing regarding the operation | movement form of a sensor detection signal process part. It is explanatory drawing of the modification regarding the movable component for camera shake correction. It is explanatory drawing of the modification regarding the movable component for camera shake correction. It is an external view of the mobile telephone (smart phone) regarding this embodiment. 1 is an external view of a digital still camera according to an embodiment. 1 is an external view of a digital video camera according to an embodiment.

  Embodiments of the present invention will be described below by taking each of the first to fifth embodiments as an example.

1. First Embodiment [Entire Configuration of Imaging Device, etc.]
First, a first embodiment will be described below with reference to the drawings. FIG. 1 is a block diagram of an imaging apparatus according to an embodiment of the present invention. The imaging device 9 of this embodiment includes a lens unit 1, a position sensor 2, a lens driving motor 3, a gyro sensor 4, a lens control device 6, and the like, and has a camera shake correction function.

  The lens unit 1 includes a lens 1a that is a camera shake correction lens, and an optical image of a subject is captured using an image sensor (CCD [Charge Coupled Device] or CMOS [Complementary Metal Oxide] in the imaging device 9 using the lens 1a. Semiconductor] etc.). The image pickup device 9 can expose the image sensor via the lens 1a to pick up an image of the subject. The lens 1 a is a movable member that is elastically supported by a spring (elastic body) with respect to a fixed portion of the lens unit 1.

  The position sensor 2 is a sensor that continuously detects the position (current position) of the lens 1a. For example, a hall sensor or a photo reflector is applied. This detection result signal (current position signal) is subjected to processing such as AD conversion, and is then sent to the adder 12 in the lens control device 6.

  The lens driving motor 3 is configured by, for example, a VCM [Voice Coil Motor], and drives the lens 1 a with a driving force corresponding to the motor current output from the lens control device 6.

  The gyro sensor 4 is a kind of angular velocity sensor, and continuously detects the amount of camera shake (shake amount) in the imaging device 9. This detection result signal (sensor detection signal) is sent to the sensor detection signal processing unit 11 in the lens control device 6.

  The lens control device 6 includes a sensor detection signal processing unit 11, an addition unit 12, a PID [P: Proportinal, I: Integral, D: Differential] filter 13, a driver unit 14, and the like. The lens control device 6 is formed as a semiconductor device in which these parts are integrated.

  The sensor detection signal processing unit 11 receives a sensor detection signal from the gyro sensor 4 and executes signal processing for generating a target position signal. The target position signal is a signal that represents the position of the lens 1a (that is, the target position of the lens 1a) at which blurring of the captured image due to camera shake (shake of the imaging device 9) is suppressed. A more detailed configuration and the like of the sensor detection signal processing unit 11 will be described again.

  The adder 12 calculates a difference between the value of the target position signal and the value of the current position signal output from the position sensor 2, and outputs the calculation result to the PID filter 13.

  The PID filter 13 generates an output signal based on the information received from the adder 12 so that the difference between the value of the target position signal and the value of the current position signal approaches zero, and outputs the output signal to the driver unit 14.

  The driver unit 14 generates a motor current corresponding to the output signal of the PID filter 13 and outputs it to the lens driving motor 3. Accordingly, the lens driving motor 3 drives the lens 1a so that the current position approaches the target position.

  Note that a portion including the addition unit 12, the PID filter 13, the driver unit 14, and the like corresponds to a portion that controls the position of the lens 1a so as to approach the target position based on the target position signal. That is, in this portion, the position of the lens 1a is controlled so that the difference between the current position signal and the target position signal is small, so that the camera shake correction function is exhibited in the imaging device 9.

[Configuration of sensor detection signal processor]
Next, a more detailed configuration of the sensor detection signal processing unit 11 will be described. FIG. 2 is a block diagram of the sensor detection signal processing unit 11. The sensor detection signal processing unit 11 is provided corresponding to each sensor detection signal in the yaw direction and the pitch direction, for example. As shown in the figure, the sensor detection signal processing unit 11 includes a gyro operation unit 20 and a pan / tilt control unit 30.

  The gyro operation unit 20 includes an amplifier 21, a low-pass filter 22, a high-pass filter 23, an integrator 24 with a limiter, and an equalizer 25, and mainly plays a role of performing an arithmetic process using a sensor detection signal.

  The amplifier 21 performs a predetermined amplification process on the sensor detection signal received from the gyro sensor 4 and sends it to the low-pass filter 22. The low-pass filter 22 performs low-pass filter processing on the sensor detection signal received from the amplifier 21 and sends it to the high-pass filter 23.

  The high-pass filter 23 performs high-pass filter processing on the sensor detection signal received from the low-pass filter 22 and sends it to the integrator 24 with limiter. The high-pass filter 23 is formed so that the cutoff frequency is variable and the offset value Ofs is held. This offset value Ofs is an intermediate value of the calculation of the filter processing performed by the high-pass filter 23.

  FIG. 3 shows the configuration of the high-pass filter 23. As shown in the figure, the high-pass filter 23 includes a low-pass filter 40 that is a primary IIR filter to which the input value of the high-pass filter 23 is input. Further, the high pass filter 23 is configured to output a value obtained by subtracting the output value of the low pass filter 40 from the input value of the high pass filter 23 as the output value of the high pass filter 23.

  The low-pass filter 40 includes a delay element 41 that holds the input value of the low-pass filter 40, a delay element 42 that holds the output value of the low-pass filter 40, a limiter element 43 for suppressing overflow in calculation, and a predetermined coefficient for the input value Multipliers (44a to 44c) for multiplying and each adder (45a, 45b) for adding each input value. The coefficients and the like in each multiplier (44a to 44c) are appropriately set in advance so that the primary IIR filter forms a low-pass filter.

  The input value of the low-pass filter 40 is input to the adder 45a through the multiplier 44a, and is input to the adder 45a through the delay element 41 and the multiplier 44b. Further, the output value of the adder 45a is input to the adder 45b, and the output value of the adder 45b is input via the limiter element 43, the delay element 42, and the multiplier 44c.

  The output value of the limiter element 43 becomes the output value of the low-pass filter 23. The value held in the delay element 42 corresponds to the offset value Ofs. The offset value Ofs correlates with the offset of the gyro sensor 4.

  According to the high-pass filter having the configuration shown in FIG. 3, the offset value Ofs is reset at an appropriate timing, and even in a situation where the sensor detection signal is noisy (for example, when the imaging device 9 is in a handheld state). It becomes easy to restore the operation to a normal state.

  Returning to FIG. 2, the integrator 24 with limiter executes integration processing of the sensor detection signal received from the high-pass filter 23, and sends the resultant signal to the equalizer 25. The integrator 24 with limiter has a limiter function for limiting the gain, and is formed so that the cutoff frequency is variable.

  The equalizer 25 subjects the signal received from the integrator 24 with limiter to a process of correcting the advance or delay of the phase and outputs the processed signal to the subsequent stage. The output signal of the equalizer 25 is sent to the subtracter 12 as a target position signal representing the target position of the lens 1a.

  The pan / tilt control unit 30 includes a pan / tilt start detection unit 31, a pan / tilt end detection unit 32, and a cut-off control unit 33. The gyro operation mainly corresponds to panning and tilting. It plays a role of controlling the unit 20.

  The pan / tilt start detection unit 31 starts panning or tilting (for example, the imaging device 9 is moved in approximately one direction to change the composition, and may be abbreviated as “pan / tilt” hereinafter). It is detected that More specifically, the pan / tilt start detection unit 31 monitors the signal level of the output signal of the equalizer 25 (representing the level of the integrated value of the sensor detection signal), and the signal level has exceeded a predetermined threshold Ta. Is detected as the start of pan / tilt.

  When panning / tilting is started, the imaging device 9 continuously moves in a substantially one direction for a relatively long time, and the integrated value of the sensor detection signal increases. Therefore, the pan / tilt start detection unit 31 can determine the start of pan / tilt as described above. Information on the detection result by the pan / tilt start detection unit 31 is transmitted to the cut-off control unit 33.

  The pan / tilt end detection unit 32 detects that pan / tilt has ended. More specifically, the pan / tilt end detection unit 32 monitors the signal level of the output signal of the integrator 24 with limiter (represents the level of the integrated value of the sensor detection signal), and this signal level is equal to or lower than the threshold Ta. This is detected as the end of pan / tilt. Information on the detection result by the pan / tilt end detection unit 32 is transmitted to the cut-off control unit 33.

  The cut-off control unit 33 controls the cut-off frequency of the high-pass filter 23 and the integrator 24 with limiter based on the detection results of the pan / tilt start detection unit 31 and the pan / tilt end detection unit 32. Further, the cutoff control unit 33 further plays a role of resetting the offset value Ofs (returning to the initial value).

[Operation mode of sensor detection signal processing unit]
Next, the operation mode of the sensor detection signal processing unit 11 will be described below with reference to the state transition diagram shown in FIG. Here, a state in which pan / tilt is not detected is referred to as a “normal state”.

  In the “normal state”, the cutoff frequency of the high-pass filter 23 and the integrator 24 with limiter is set so that noise included in the sensor detection signal is appropriately removed. Thereby, a target position signal for suppressing blurring of a captured image due to camera shake is appropriately generated, and as a result, the imaging device 9 can exhibit a high-performance camera shake correction function.

  However, when panning / tilting is performed, since the photographer intends to change the composition, it is important to make it easier to return the lens 1a to the center (the center of the movable region) rather than the camera shake correction. Therefore, when the pan / tilt control unit 30 detects the start of pan / tilt in the “normal state” (when the monitored signal level exceeds the threshold value Ta), the pan / tilt control unit 30 cuts the high-pass filter 23 and the integrator 24 with limiter. The off frequency is set to a predetermined value higher than that in the “normal state” (step S11).

  As a result, the state of the sensor detection signal processing unit 11 shifts from the “normal state” to the “pan / tilt detection state”. In the “pan / tilt detection state”, since the cutoff frequency of the high-pass filter 23 and the integrator 24 with limiter is high, the lens 1a can be returned to the center more quickly.

  When the pan / tilt control unit 30 detects the end of pan / tilt in the “pan / tilt detection state” (when the monitored signal level is equal to or lower than the threshold Ta), the pan / tilt control unit 30 integrates with the high-pass filter 23 and the limiter. The cutoff frequency of the device 24 is returned to a normal value (lower than the current value), and the offset value Ofs is reset (step S12).

  As a result, the state of the sensor detection signal processing unit 11 shifts from the “pan / tilt detection state” to the “normal state”. In the “normal state”, as described above, a high-performance camera shake correction function can be exhibited.

  Further, by resetting the offset value Ofs, the bias of the offset value Ofs is eliminated, and for example, the target position of the lens 1a can be returned from the center after panning / tilting.

  In the first embodiment, as described above, when the start of pan / tilt is detected (when the level of the integrated value of the sensor detection signal exceeds the threshold value Ta), the cutoff frequency of the high-pass filter 23 and the like is increased, When the end of pan / tilt is detected (when the level of the integral value becomes equal to or less than the threshold value Ta), the cutoff frequency is restored. Therefore, it is possible to appropriately cope with panning and tilting.

  In the first embodiment, the lens 1a is used even when panning / tilting is performed in a situation where there is little noise in the sensor detection signal, or when a shake that does not allow camera shake correction is applied (during large shake). Can be controlled relatively well.

2. Second Embodiment Next, a second embodiment will be described. Note that the imaging apparatus of the second embodiment is basically the same as the imaging apparatus of the first embodiment except for the configuration and operation mode of the sensor detection signal processing unit. In the following description, emphasis is placed on the description of parts that are different from the first embodiment, and description of parts that are equivalent to the first embodiment may be omitted.

[Configuration of sensor detection signal processor]
FIG. 4 is a block diagram of the sensor detection signal processing unit 11 according to the second embodiment. As shown in the figure, the sensor detection signal processing unit 11 includes a gyro operation unit 20 and a pan / tilt control unit 30.

  The gyro operation unit 20 includes an amplifier 21, a low-pass filter 22, a high-pass filter 23, an integrator 24 with limiter, a pan / tilt detection integrator 27, and a save register 28. The configurations of the amplifier 21, the low-pass filter 22, the high-pass filter 23, and the integrator with limiter 24 are basically the same as those in the first embodiment. The output signal of the integrator 24 with limiter is sent to the subtracter 12 as a target position signal indicating the target position of the lens 1a.

  The pan / tilt detection integrator 27 receives a sensor detection signal from the high-pass filter 23, executes an integration process on the sensor detection signal, and outputs a signal representing the result. The output signal of the pan / tilt detection integrator 27 is used to detect the start and end of pan / tilt, as will be described later.

  It should be noted that the pan / tilt detection integrator 27 and the limiter-equipped integrator 24 are arranged so that panning and tilting movements are detected better (for example, to prevent excessive pan / tilt detection). Unlike the above, there is no limiter function for limiting the gain.

  The save register 28 is a register for saving the offset value Ofs. The save register 28 holds the latest offset value Ofs (updates the held contents) every time the offset value Ofs is saved.

  The pan / tilt control unit 30 includes a pan / tilt detection unit 35 and an offset value control unit 36.

  The pan / tilt detection unit 35 monitors the signal level of the output signal of the pan / tilt detection integrator 27 (hereinafter referred to as “signal level A” for convenience) and the sign of the output signal of the high-pass filter 23. Detects the start and end of pan / tilt. The signal level A can be said to represent the level of the integrated value of the sensor detection signal. The signal level A may be the signal level of the output signal of the integrator 24 with limiter, for example.

  The pan / tilt detector 35 detects that the signal level A exceeds a predetermined threshold Ta as the start of pan / tilt. The pan / tilt detector 35 detects that the sign of the output signal of the high pass filter 23 has been inverted after the start of pan / tilt as the end of pan / tilt.

  The pan / tilt detector 35 also detects that the signal level A exceeds a predetermined threshold Ta ′ (set to a value lower than the threshold Ta). Note that when the signal level of the output signal exceeds the threshold Ta ′, the possibility of starting pan / tilt is relatively high. Therefore, at this time, as will be described later, preparations for pan / tilt are made.

  The pan / tilt detector 35 also detects that the sign of the output signal of the high-pass filter 23 is inverted after the signal level A exceeds a predetermined threshold Ta ′ (set to a value lower than the threshold Ta). . Information of each detection result by the pan / tilt detection unit 35 is transmitted to the offset value control unit 36.

  Based on the detection result of the pan / tilt detection unit 35, the offset value control unit 36 saves the offset value Ofs and returns the offset value Ofs (replaces the offset value Ofs with the value saved in the save register 28). Control).

[Operation mode of sensor detection signal processing unit]
Next, the operation mode of the sensor detection signal processing unit 11 will be described below with reference to the state transition diagram shown in FIG. Here, the state in which the signal level A is equal to or lower than the threshold Ta ′ is referred to as “normal state”.

  When it is detected in the “normal state” that the signal level A exceeds the threshold Ta ′, the state of the sensor detection signal processing unit 11 shifts from the “normal state” to the “pan / tilt detection preparation state” ( Step S21). At this time, the pan / tilt control unit 30 causes the offset value Ofs to be saved. As described above, the pan / tilt control unit 30 saves the offset value Ofs before the start of pan / tilt (before the image pickup apparatus 9 is largely moved), and saves the offset value Ofs before the value is largely biased. It is supposed to let you.

  When the pan / tilt control unit 30 detects the start of pan / tilt (the signal level A exceeds the threshold Ta) in the “pan / tilt detection preparation state”, the state of the sensor detection signal processing unit 11 is “ The process proceeds from the “pan / tilt detection preparation state” to the “pan / tilt detection state” (step S22).

  When the pan / tilt control unit 30 detects inversion of the sign of the output signal of the high pass filter 23 in the “pan / tilt detection state”, the state of the sensor detection signal processing unit 11 changes from “pan / tilt detection state” to “ The process proceeds to the “normal state” (step S23). At this time, the pan / tilt control unit 30 executes the return of the offset value Ofs. As a result, the large bias of the offset value Ofs can be eliminated, and the target position of the lens 1a can be set to a more desirable state (for example, a state closer to the center).

  When the pan / tilt control unit 30 detects inversion of the sign of the output signal of the high-pass filter 23 in the “pan / tilt detection preparation state”, the state of the sensor detection signal processing unit 11 is “pan / tilt detection preparation state”. To “normal state” (step S24). At this time, since the bias of the offset value Ofs is relatively small, unlike the case of step S23, the offset value Ofs is not returned.

  In the second embodiment, the offset value Ofs is saved in the save register 28 when the level of the integrated value of the sensor detection signal (signal level A) exceeds the threshold Ta ′. Further, when the sign of the output of the high pass filter 23 is inverted after the level of the integrated value of the sensor detection signal exceeds the threshold value Ta (higher than the threshold value Ta ′), the offset value Ofs is saved in the save register 28. On the other hand, when the level of the integrated value of the sensor detection signal does not exceed the threshold value Ta and the sign of the output of the high-pass filter 23 is inverted, the replacement is not performed.

3. Third Embodiment Next, a third embodiment will be described. The imaging device of the third embodiment is basically the same as the imaging device of the second embodiment, except for the configuration of the sensor detection signal processing unit. In the following description, emphasis is placed on the description of parts different from the second embodiment, and description of parts equivalent to the second embodiment may be omitted.

  FIG. 5 is a block diagram of the sensor detection signal processing unit 11 according to the third embodiment. As shown in the figure, the sensor detection signal processing unit 11 includes a gyro operation unit 20 and a pan / tilt control unit 30 as in the case of the second embodiment.

  However, in the third embodiment, an equalizer 25 is further provided as a component of the gyro operation unit 20, and a pan / tilt detection unit 37 and a cutoff control unit 38 are further provided as components of the pan / tilt control unit 30. It has been.

  The equalizer 25 subjects the signal received from the integrator 24 with limiter to a process of correcting the advance or delay of the phase and outputs the processed signal to the subsequent stage. The output signal of the equalizer 25 is sent to the subtracter 12 as a target position signal representing the target position of the lens 1a. The equalizer 25 is formed so that the cutoff frequency is variable.

  The pan / tilt detector 37 monitors the signal level of the output signal of the equalizer 25 (hereinafter referred to as “signal level B” for convenience) and detects the start and end of pan / tilt. More specifically, the pan / tilt detector 37 detects that the signal level B exceeds the threshold Ta as the start of pan / tilt. The pan / tilt detector 37 detects that the signal level B has fallen below the threshold Ta as the end of pan / tilt. It can be said that the signal level B represents the level of the integrated value of the sensor detection signal.

  The cutoff control unit 38 controls the cutoff frequency of the equalizer 25 based on the detection result of the pan / tilt detection unit 37. More specifically, the cut-off control unit 38 sets the cut-off frequency of the equalizer 25 to a predetermined value higher than usual until the end is detected after the start of pan / tilt is detected.

  In the pan / tilt control unit 30, a part related to the control of the high-pass filter 23 (pan / tilt detection unit 35 and offset value control unit 36) and a part related to the control of the equalizer 25 (pan / tilt detection unit 37 and cut-off). The control unit 38) is provided separately. Thereby, simplification of the system related to the control of the gyro operation unit 20 is facilitated.

  In the sensor detection signal processing unit 11 in the third embodiment, in addition to the same operation as in the second embodiment, an operation of increasing the cutoff frequency of the equalizer 25 is performed when pan / tilt is detected. . This operation is intended to conform to the operation performed by the pan / tilt control unit 30 of the first embodiment (the operation of increasing the cutoff frequency of the high-pass filter 23 and the like).

  That is, in the third embodiment, when pan / tilt is not detected, the cutoff frequency of the equalizer 25 is set so that the imaging device 9 exhibits a high-performance camera shake correction function. On the other hand, when pan / tilt is detected, the cutoff frequency of the equalizer 25 is increased so that the lens 1a can easily return to the center.

  In the second or third embodiment, the release timing in the yaw direction and the pitch direction is likely to be the same as in the first embodiment, and the lens 1a is set to “L” even when the pan / tilt is performed in an oblique direction. The phenomenon of returning to the center is less likely to occur. Furthermore, it is possible to avoid a state in which the correction of the lens position does not work in the vibration state.

  In the second or third embodiment, for example, when pan / tilt is performed in a situation where there is a lot of noise in the sensor detection signal, or when shake enough to correct camera shake is applied (during medium excitation), etc. The position of the lens 1a can be controlled relatively well.

  FIG. 9 illustrates a graph relating to the movement of the lens 1a during pan / tilt in a situation where there is a lot of noise. In FIG. 9, the horizontal axis represents time, and the vertical axis represents the position of the lens 1a. The graph of the second or third embodiment is represented by a solid line, and the graph of the first embodiment is represented by a broken line.

  In the first embodiment, as shown in the figure, there is a possibility that the lens 1a moves to the end again after the lens 1a is returned to the vicinity of the center after the end of pan / tilt. This phenomenon is mainly caused by returning the cut-off frequency of the high-pass filter 23 while the imaging device 9 is still moving. However, in the second or third embodiment, such a phenomenon is difficult to occur.

  Moreover, the graph regarding the motion of the lens 1a at the time of a medium vibration is illustrated in FIG. In FIG. 10, the horizontal axis represents time, and the vertical axis represents the position of the lens 1a. The graph of the second or third embodiment is represented by a solid line, and the graph of the first embodiment is represented by a broken line.

  In the first embodiment, as shown in the drawing, even when a shake that can be corrected is applied, the movement of the lens 1a may not be correctly converged (for example, the operating point is biased). However, in the second or third embodiment, such a phenomenon is avoided.

4). Fourth Embodiment Next, a fourth embodiment will be described. The imaging device of the fourth embodiment is equivalent to the imaging device of the second or third embodiment except for the operation mode of the sensor detection signal processing unit. Therefore, hereinafter, the operation mode of the sensor detection signal will be described, and description of other parts will be omitted.

  The operation mode of the sensor detection signal processing unit 11 will be described below with reference to the state transition diagram shown in FIG. The sensor detection signal processing unit 11 basically performs the same operation as in the second or third embodiment.

  However, in the sensor detection signal processing unit 11 of the fourth embodiment, the operation of step S25 is performed instead of saving the offset value Ofs when shifting from the “normal state” to the “pan / tilt detection preparation state”. It has become. That is, the pan / tilt control unit 30 saves the offset value Ofs as a save register when the level of the integrated value of the sensor detection signal (signal level A) continues to be equal to or lower than the threshold value Ta ′ as the operation of step S25. The operation of retracting to 28 is performed.

  Accordingly, in the fourth embodiment, the advantages of the second or third embodiment are maintained, and the stability of the operation at the time of panning / tilting with the imaging device 9 held by hand is higher. In the second or third embodiment, when a large vibration continues, the offset value becomes abnormal, and there is a concern that the operating point may be greatly shifted and a normal control becomes difficult (singular state). In the fourth embodiment, such a singular state is unlikely to be obtained, and even if it becomes a singular state, it recovers in a certain time.

  FIG. 11 illustrates a graph relating to the movement of the lens 1a during large vibration. In FIG. 11, the horizontal axis represents time, and the vertical axis represents the position of the lens 1a. The graph of the fourth embodiment is represented by a solid line, and the graph of the second or third embodiment is represented by a broken line.

  In the second or third embodiment, as shown in the drawing, when a large vibration continues, the operating point of the lens 1a may move to the end. However, in the fourth embodiment, such a phenomenon is difficult to occur.

5. Fifth Embodiment Next, a fifth embodiment will be described. Note that the imaging apparatus of the fifth embodiment is basically the same as the imaging apparatus of the second embodiment, except for operations performed by the sensor detection signal processing unit. In the following description, emphasis is placed on the description of parts different from the second embodiment, and description of parts equivalent to the second embodiment may be omitted.

  FIG. 12 is a block diagram of the sensor detection signal processing unit 11 according to the fifth embodiment. As shown in the figure, the sensor detection signal processing unit 11 includes a gyro operation unit 20 and a pan / tilt control unit 30 as in the case of the second embodiment.

  However, the pan / tilt control unit 30 (offset value control unit 36) in the fifth embodiment, in addition to the control of saving the offset value Ofs and the return of the offset value Ofs, will be described later. The cutoff frequency is controlled.

  Next, the operation form of the sensor detection signal processing unit 11 will be described below with reference to the state transition diagram shown in FIG. Here, a state in which the signal level A is equal to or lower than the threshold Ta ′ is referred to as a “normal state”.

  When it is detected in the “normal state” that the signal level A exceeds the threshold Ta ′, the state of the sensor detection signal processing unit 11 shifts from the “normal state” to the “pan / tilt detection preparation state” ( Step S31). At this time, the pan / tilt control unit 30 causes the offset value Ofs to be saved. As described above, the pan / tilt control unit 30 saves the offset value Ofs before the start of pan / tilt (before the image pickup apparatus 9 is largely moved), and saves the offset value Ofs before the value is largely biased. It is supposed to let you.

  When the pan / tilt control unit 30 detects the start of pan / tilt (the signal level A exceeds the threshold Ta) in the “pan / tilt detection preparation state”, the state of the sensor detection signal processing unit 11 is “ The process proceeds from the “pan / tilt detection preparation state” to the “pan / tilt detection state” (step S32).

  At this time, the pan / tilt control unit 30 changes the cutoff frequency of the integrator 24 with limiter to a predetermined value higher than that in the “normal state”. As a result, the integrator 24 with limiter has a higher cutoff frequency and lowers the input sensitivity. In the “pan / tilt detection state”, since the cutoff frequency of the integrator 24 with limiter is high, the lens 1a can be returned to the center more quickly.

  Note that the state of the sensor detection signal processing unit 11 immediately shifts to a “pan / tilt release waiting state” after entering the “pan / tilt detection state”. The “pan / tilt release waiting state” is a state in which the cutoff frequency of the integrator 24 with limiter is maintained at the value in the “pan / tilt detection state” and waits for the release of the “pan / tilt detection state”. .

  In the “pan / tilt release waiting state”, the pan / tilt control unit 30 monitors whether or not the signal level A exceeds the threshold Ta. When it is detected that the signal level A exceeds the threshold Ta, the state of the sensor detection signal processing unit 11 shifts from the “pan / tilt release waiting state” to the “pan / tilt detection state” (step S33). ).

  However, if the signal level A does not exceed the threshold Ta for a certain period of time, the state of the sensor detection signal processing unit 11 shifts from the “pan / tilt release waiting state” to the “normal state” (step S34). ). At this time, the pan / tilt control unit 30 executes the return of the offset value Ofs and returns the cutoff frequency of the integrator 24 with limiter to the normal value (cancels the change of the cutoff frequency).

  When the pan / tilt control unit 30 detects inversion of the sign of the output signal of the high-pass filter 23 in the “pan / tilt detection preparation state”, the state of the sensor detection signal processing unit 11 is “pan / tilt detection preparation state”. To “normal state” (step S35). At this time, since the bias of the offset value Ofs is relatively small, unlike the case of step S34, the offset value Ofs is not returned.

  As described above, in the fifth embodiment, when the signal level A (the signal level of the output signal of the pan / tilt detection integrator 27) exceeds the threshold value Ta (predetermined reference threshold value), the integrator 24 with limiter 24 The cut-off frequency is increased. Further, after the cutoff frequency of the integrator 24 with limiter is increased, when the signal level A does not exceed the threshold value Ta continuously for a predetermined time, the cutoff frequency of the integrator 24 with limiter is restored. .

  That is, in the fifth embodiment, when pan / tilt is not detected, the cutoff frequency of the integrator 24 with limiter is set so that the imaging device 9 exhibits a high-performance camera shake correction function. On the other hand, when pan / tilt is detected, it is possible to increase the cutoff frequency of the integrator 24 with limiter so that the lens 1a can be easily returned to the center.

  Furthermore, in the fifth embodiment, a period of waiting for pan / tilt cancellation is provided, and the cutoff frequency of the integrator 24 with limiter is maintained at a high value during this period. Therefore, compared with a case where a period of waiting for pan / tilt cancellation is not provided (for example, when the cutoff frequency of the integrator 24 with limiter is immediately restored to the original level when the signal level A does not exceed the threshold Ta). It is possible to further stabilize the position of the lens 1a after panning and tilting.

  Therefore, according to the fifth embodiment, it is possible to obtain the above-described advantages while having advantages similar to those of the second embodiment. Here, FIGS. 14 and 15 illustrate graphs relating to the movement of the lens 1a during pan / tilt. In each figure, the horizontal axis represents time, and the vertical axis represents the position of the lens 1a.

  In FIG. 14, the graph of the fifth embodiment (when the cutoff frequency of the integrator 24 with limiter is changed) is represented by a solid line. On the other hand, a graph when the cutoff frequency of the integrator 24 with limiter is not changed (other conditions are the same as those of the fifth embodiment) is represented by a broken line. As shown in FIG. 14, according to the fifth embodiment, the lens 1a quickly returns to the center as compared with the case where the cutoff frequency of the integrator 24 with limiter is not changed.

  In FIG. 15, the graph of the fifth embodiment (when a period of waiting for pan / tilt release is provided) is represented by a solid line. On the other hand, a graph in a case where a period of waiting for pan / tilt cancellation is not provided (other conditions are the same as in the fifth embodiment) is represented by a broken line.

  As shown in FIG. 15, according to the fifth embodiment, the lens 1a when the change of the cut-off frequency of the integrator 24 with limiter is canceled is compared with the case where the period of the pan / tilt cancellation waiting state is not provided. Is prevented from moving again toward the end side (bulging on the graph), and the position of the lens 1a after panning / tilting becomes more stable. Note that the timings (A) and (B) shown in FIG. 15 correspond to the timings (A) and (B) shown in FIG. 13, respectively.

  In the fifth embodiment, the features of the fourth embodiment described above may be incorporated. In this case, as shown in the state transition diagram of FIG. 16, the sensor detection signal processing unit 11 instead of saving the offset value Ofs at the time of transition from the “normal state” to the “pan / tilt detection preparation state”, The operation of Step S36 (the operation equivalent to Step S25 in the fourth embodiment) is performed.

  In other words, the pan / tilt control unit 30 saves the offset value Ofs as a save register when the level of the integrated value of the sensor detection signal (signal level A) continues to be equal to or lower than the threshold value Ta ′ as the operation of step S36. The operation of retracting to 28 is performed. Thereby, also in 5th Embodiment, it is possible to acquire the advantage according to the case of 4th Embodiment.

6). Others The sensor detection signal processing unit 11 of each embodiment is provided in the imaging device 9 having the gyro sensor 4 that detects the shake amount, and is a signal processing device that generates a target position signal based on the sensor detection signal. . As described above, according to the signal processing device, it is possible to appropriately cope with panning, tilting, and the like.

  In addition, the lens control device 6 of each embodiment includes a sensor detection signal processing unit 11 (signal processing device), and the lens 1a approaches the target position based on the target position signal generated by the sensor detection signal processing unit 11. Control the position of the. According to the lens control device 6 and the imaging device 9 of each embodiment, it is possible to enjoy the advantages of the sensor detection signal processing unit 11.

  In each embodiment, the movable lens 1a is adopted as a movable part for camera shake correction (camera correction). However, other forms may be used. For example, as a modification of each embodiment, an image sensor or a camera module (a module having a lens and an image sensor) is a movable part for camera shake correction.

  FIG. 17 illustrates a block diagram of the imaging device 9 when an image sensor is employed as a movable part for camera shake correction. The imaging device 9 shown in this figure includes a camera module 7 having a lens 7a and an image sensor 7b, and the image sensor 7b is movable.

  A position sensor 2a for detecting the position of the image sensor 7b is provided instead of the position sensor 2, and a motor 3a for driving the image sensor 7b is provided instead of the lens driving motor 3. Further, instead of the lens control device 6, a control device 6a for controlling the position of the image sensor 7b is provided. The control device 6a controls the position of the image sensor 7b through the motor 3a so that the difference between the current position signal output from the position sensor 2a and the target position signal is small, and the camera shake correction function is exhibited in the imaging device 9. So that

  FIG. 18 illustrates a block diagram of the imaging device 9 when a camera module is employed as a movable part for camera shake correction. The imaging device 9 shown in this figure includes a camera module 7 having a lens 7a and an image sensor 7b, and the camera module 7 is movable.

  A position sensor 2 b that detects the position of the camera module 7 is provided instead of the position sensor 2, and a motor 3 b that drives the camera module 7 is provided instead of the lens drive motor 3. Further, instead of the lens control device 6, a control device 6b for controlling the position of the camera module 7 is provided. The control device 6b controls the position of the camera module 7 through the motor 3b so that the difference between the current position signal output from the position sensor 2b and the target position signal is small, and the camera shake correction function is exhibited in the imaging device 9. So that

  The configuration of the present invention can be variously modified in addition to the above embodiment without departing from the spirit of the invention. That is, the above-described embodiment is an example in all respects and should not be considered as limiting, and the technical scope of the present invention is not the description of the above-described embodiment, but the claims. It should be understood that all modifications that come within the meaning and range of equivalents of the claims are included. Further, the present invention can be used in various applications such as a digital still camera, a digital video camera, a surveillance camera, and a camera module for a mobile phone.

  Here, a mobile phone, a digital still camera, and a digital video camera are given as specific examples of the imaging device 9, and external views of the respective devices are shown in FIGS.

  FIG. 19 is an external view of the mobile phone (smart phone). The cellular phone A of this configuration example displays an imaging unit A1 mounted on the front and back of the main body, an operation unit A2 (such as various buttons and a touch panel) that accepts user operations, and characters and videos (including photographed images). And a display unit 3. The mobile terminal as the imaging device 9 is not limited to a mobile phone, and includes notebook PCs, tablet PCs, mobile game machines, and the like.

  FIG. 20 is an external view of the digital still camera. The digital still camera B of this configuration example includes an imaging unit B1 that captures a still image, an operation unit B2 (such as a release button and a zoom lever) that receives a user operation, a display unit B3 that displays a captured image and a menu screen, Have

  FIG. 21 is an external view of the digital video camera. The digital video camera C of this configuration example includes an imaging unit C1 that captures a moving image, an operation unit C2 that receives user operations (such as a shooting start / stop button and a zoom lever), and a display unit C3 that displays captured images and menu screens. And having.

  Any of the imaging devices A to C has the features of the imaging device 9 described above.

  The present invention can be used for an imaging apparatus having a camera shake correction function.

DESCRIPTION OF SYMBOLS 1 Lens unit 1a Lens 2 Position sensor 2a Position sensor 2b Position sensor 3 Lens drive motor 3a Motor 3b Motor 4 Gyro sensor 6 Lens control apparatus 6a Control apparatus 6b Control apparatus 7 Camera module 7a Lens 7b Image sensor 9 Imaging apparatus 11 Sensor detection signal Processing unit 12 Addition unit 13 PID filter 14 Driver unit 20 Gyro operation unit 21 Amplifier 22 Low-pass filter 23 High-pass filter 24 Integrator with limiter (first integrator)
25 Equalizer 27 Pan / tilt detection integrator (second integrator)
28 Pan / Tilt Control Unit 31 Pan / Tilt Start Detection Unit 32 Pan / Tilt End Detection Unit 33 Cutoff Control Unit 35 Pan / Tilt Detection Unit 36 Offset Value Control Unit 37 Pan / Tilt Detection Unit 38 Cutoff Control Unit 40 Low-pass filter 41, 42 Delay element 43 Limiter element 44a-44c Multiplier 45a, 45b Adder A Cellular phone (smart phone)
B Digital still camera C Digital video camera A1, B1, C1 Imaging unit A2, B2, C2 Operation unit A3, B3, C3 Display unit

Claims (14)

The signal processing device is provided in an imaging device having a sensor for detecting a shake amount and a movable component for shake correction, and generates a signal representing a target position of the movable component for shake correction based on a detection signal of the sensor. And
A high-pass filter that performs high-pass filtering on the detection signal, and is configured to hold an intermediate value of an operation of the filtering;
A saving register used for saving the intermediate value;
When the level of the integral value of the detection signal exceeds a predetermined first threshold, the intermediate value is saved in the save register, and when the predetermined condition is satisfied, the intermediate value is saved in the save register. An evacuation control unit that replaces the value
A signal processing apparatus comprising: The signal processing device is provided in an imaging device having a sensor for detecting a shake amount and a movable component for shake correction, and generates a signal representing a target position of the movable component for shake correction based on a detection signal of the sensor. And
A high-pass filter that performs high-pass filtering on the detection signal, and is configured to hold an intermediate value of an operation of the filtering;
A saving register used for saving the intermediate value;
The intermediate value is saved in the save register when the level of the integrated value of the detection signal continues for a predetermined time and is not more than a predetermined first threshold value, and when the predetermined condition is satisfied, the intermediate value is saved in the save value. A save control unit that replaces the value saved in the register;
A signal processing apparatus comprising: A first integrator having a variable cut-off frequency and executing an integration process of the detection signal;
A second integrator that executes integration processing of the detection signal, and when the signal level of the output signal of the second integrator exceeds a predetermined reference threshold, the cutoff frequency of the first integrator is increased. The signal processing apparatus according to claim 1, wherein the signal processing apparatus is a signal processing apparatus.   After the cutoff frequency of the first integrator is increased, the cutoff frequency of the first integrator is returned to the original when the signal level does not exceed the reference threshold continuously for a certain period of time. The signal processing apparatus according to claim 3. The high-pass filter is
It has a low pass filter of a primary IIR filter to which the input value of the high pass filter is input, and is configured to output a value obtained by subtracting the output value of the low pass filter from the input value of the high pass filter,
The low-pass filter is provided with a delay element that holds the output value of the low-pass filter,
The signal processing apparatus according to claim 1, wherein the intermediate value is a value held in the delay element. The evacuation control unit
When the sign of the output of the high-pass filter is reversed after the level of the integrated value of the detection signal exceeds a second threshold value that is higher than the first threshold value, the offset value is replaced with a value saved in the save register. on the other hand,
6. The signal processing apparatus according to claim 5, wherein the replacement is not performed when the level of the integrated value of the detection signal does not exceed a second threshold and the sign of the output of the high-pass filter is inverted.    The signal processing apparatus according to claim 1, wherein the target position is a position of the shake correction movable part at which blurring of a captured image due to shake of the imaging apparatus is suppressed.   The signal processing apparatus according to claim 1, wherein the sensor is a gyro sensor.   The signal processing apparatus according to claim 1, wherein the shake correction movable part is a movable lens. A signal processing device according to claim 9,
A lens control device that controls the position of the lens so as to approach the target position based on a signal representing the target position generated by the signal processing device. Obtaining a current position signal representing the current position of the lens;
The lens control apparatus according to claim 10, wherein the position of the lens is controlled so that a difference between the current position signal and a signal representing the target position is reduced.   The lens control apparatus according to claim 10, wherein the position of the lens is controlled through control of a lens driving motor that drives the lens.   An image pickup apparatus comprising the signal processing apparatus according to claim 1.   An imaging apparatus comprising the lens control device according to claim 10.

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