JP2006317585A - Image blur correction lens device and correction method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve vibration restraining effects, by providing a tripod with an operation angle detecting means and highly accurately detecting vibration. <P>SOLUTION: In step S2, panning positional data P, outputted from a panning detection means disposed on the tripod, are inputted. In step S3, a different positional change quantity ΔP from a set reference position P0 is calculated. In step S9, determination is made whether the positional change quantity ΔP is equal to or larger than a given threshold. This process determines whether the operator of the tripod 10 has deliberately performed a panning operation. When the positional change quantity ΔP is smaller than the threshold, it is considered as vibration data, and then an HPF process in step S10 and a phase compensation process in step S11 are performed. In step S12, an adjustment coefficient is extracted by using a focal distance obtained using a focal distance detecting means and using a table stored in a CPU. By multiplying the coefficient with the vibration data created by the time of step S11, control data for an image blur correction lens group are generated. Based on the control data, the correction lens control processing of step S7 to step S14 is repeated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image blur correction lens apparatus including a tripod having an operation angle detection function and a zoom lens unit having an image blur correction function, and a correction method thereof.

  A conventional image blur correction lens system disclosed in, for example, Patent Document 1 detects vibration by a vibration sensor mounted in a lens, and controls an image blur correction lens group that decenters an optical axis in accordance with the detected vibration. As the vibration sensor, an angular velocity sensor that mainly outputs an analog signal is used. When vibration is applied, the angular velocity sensor detects an angular velocity corresponding to the vibration. The detected angular velocity is converted into a vibration angle by integrating on the hardware or software, and the control amount of the image blur correction lens group is calculated on the software in consideration of the lens state such as the focal length from the vibration angle. . Using this control data, a drive device such as an actuator is controlled to perform image blur correction.

JP 2002-49068 A

  However, the image blur correction lens system using the output of the vibration sensor mounted in the lens described above has the following two problems.

  The first problem is a vibration sensor. As described above, an angular velocity sensor is mainly used as a vibration sensor used for image blur correction. However, this type of sensor generates low-frequency noise. The SN ratio is worse than that. The frequency of this noise is about 0.1 Hz, and the vibration applied to a normal lens is lower than 1 to 15 Hz, but the frequencies are close. Therefore, if it is attempted to remove by filtering, the signal level of the low frequency vibration is also lowered, resulting in a problem that the suppression effect is lowered.

  The second problem is the vibration axis. When the vibration sensor is mounted in the lens, the vibration can be detected more accurately with respect to the vibration about the position where the vibration sensor is attached. However, in a lens system using a tripod, the center axis of vibration is the rotation axis of the tripod, and therefore the position of the vibration axis and the position of the vibration sensor differ greatly depending on the lens mounting position. For example, since the zoom lens calculates the balance with the camera and is mounted on a tripod, the lens mounting position is changed back and forth according to the weight of the camera. In such a case, there is a case where accurate vibration detection cannot be performed, and there is a problem that the suppression effect is lowered.

  An object of the present invention is to solve the above-described problems and to control the image blur correction lens group mounted in the zoom lens unit based on the output of the operation angle detection means provided on the tripod, thereby generating in the movable direction of the tripod. An object of the present invention is to provide an image blur correction lens device that performs image blur correction for vibration.

  Another object of the present invention is to provide an operation detection unit on a tripod, and if necessary, control the image blur correction lens group by any output from a vibration detection unit provided in the zoom lens. Another object of the present invention is to provide an image blur correction lens device that performs image blur correction even with respect to vibrations applied to the other.

  Still another object of the present invention is to provide a correction method for an image blur correction lens apparatus that uses an image blur correction lens group in accordance with the amount of movement of an operation detection means provided on a tripod.

  In order to achieve the above object, the technical feature of the image blur correcting lens apparatus according to the present invention is that a tripod having an operation angle detecting means for detecting a panning and tilting movement amount, an image blur correcting lens group, and the image blur correcting unit. And a zoom lens unit having a correction lens driving unit that drives the correction lens group, and the image blur correction lens group is controlled via the correction lens driving unit according to an output of the operation angle detection unit.

  The technical feature of the image blur correction lens apparatus according to the present invention is that a tripod having an operation angle detection means for detecting a panning and tilting movement amount, an image blur correction lens group, and the image blur correction lens group are driven. A zoom lens unit having a correction lens driving unit and a vibration detection unit, and a selection unit that selectively selects the operation angle detection unit or the vibration detection unit, and the operation angle detection unit is selected by the selection of the selection unit. The image blur correction lens group is controlled via the correction lens driving means according to the output of the vibration detection means or the output of the vibration detection means.

  Further, the technical feature of the correction method of the image blur correction lens apparatus according to the present invention is that the lens for correcting the image blur of the zoom lens unit using the image blur correction lens group is panned by the operation angle detection means provided on the tripod. If the movement amount is smaller than a threshold value, image blur correction control is performed by the image blur correction lens group. If the movement amount is larger than the threshold value, the image blur correction lens group is set in the center. A centering process for controlling the position is performed.

  According to the image blur correction lens device according to the present invention, the output of a sensor affected by low frequency noise such as an angular velocity sensor by performing image blur correction control using the output of the operation angle detection means mounted on the tripod. Without using a digital signal vibration detection without noise, the vibration angle and the vibration detection axis match the operation angle detection means regardless of the lens mounting position for the vibration applied to the tripod's movable direction, Vibration can always be detected accurately, and image blur correction can be performed without reducing the suppression effect even for low-frequency vibration.

  Further, according to the image blur correcting lens device of the present invention, the output of either the operation angle detecting means provided on the tripod or the vibration detecting means in the zoom lens unit is used to suppress the vibration in the tripod movable direction. Since image blur correction with high effect can be performed and image blur correction can be performed with respect to vibrations other than the tripod movement direction, an appropriate suppression effect according to the shooting situation can be obtained.

  Furthermore, according to the correction method of the image blur correcting lens device according to the present invention, it is possible to perform appropriate vibration suppression by detecting a change in the operator's intentional operation angle.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 shows a block circuit configuration diagram of the present invention, in which a zoom lens unit 20 is fixed to a tripod 10. The tripod 10 is provided with panning / tilting detection means 11 for detecting panning and tilting movement amounts, and a digital output of the detection means 11 is connected to a CPU 21 in the zoom lens unit 20. The output of the CPU 21 is sequentially connected to a D / A converter 22, a drive circuit 23, and an actuator 24, and the actuator 24 drives an image blur correction lens group 25 for decentering the optical axis. The output of the position detector 26 that detects the position of the image blur correction lens group 25 is connected to the CPU 21 via the A / D converter 27, and the output of the position detector 26 is fed back to the drive circuit 23. Yes.

  Control data calculated by the CPU 21 based on the output of the detection means 11 is converted into an analog signal by the D / A converter 22. The converted analog signal is input to the drive circuit 23. The drive circuit 23 compares the control position signal from the D / A converter 22 with the position signal input from the position detector 26, and converts it into a drive control voltage. Feedback to the actuator 24. Then, the image blur correcting lens group 25 is finally controlled by the actuator 24.

  FIG. 2 is a flowchart of an example of software processing in the CPU 21. Although only the panning direction will be described here, the same process is performed in the tilting direction.

  When power is supplied to the zoom lens unit 20 via a camera (not shown), the internal registers and memories of the CPU 21 are initialized in step S1. In step S2, the panning position data P output from the panning detection unit 11 is input. In step S3, the input value data P is set as the reference position P0. In steps S4 and S5, an HPF (High Pass Filter) process, which will be described later, and a reset process for initializing data used for the phase compensation process are performed. In step S6, a centering flag indicating whether or not to perform a centering process described later is cleared.

  Next, in steps S7 and S8, a difference position change amount ΔP from the reference position P0 set in step S3 is calculated from the panning position data P output from the panning detection means 11. Here, the calculated position change amount ΔP indicates a position change amount (P−P0) from the reference panning position, and indicates vibration applied to the movable direction of the tripod 10.

  Subsequently, in step S9, it is determined whether the position change amount ΔP is equal to or greater than a certain threshold value. This is a process for determining whether or not the operator of the tripod 10 has intentionally performed the panning operation, and the threshold value is set to the minimum amount of panning position change that can be determined to have performed the panning operation. In the embodiment, it is determined whether or not the panning operation has been performed only by the amplitude of the panning position change amount ΔP. However, it is determined by both the frequency of the position change amount ΔP and the amplitude and frequency of the position change amount ΔP. Also good.

  If the position change amount ΔP is smaller than the threshold value, the position change amount ΔP is regarded as vibration data, and HPF processing is performed in step S10. The frequency of vibration applied to the zoom lens unit 20 is mainly 1 to 15 Hz, and unnecessary components below this frequency band are removed by performing HPF processing. However, when the HPF process is performed, the phase of the vibration that is actually applied is shifted from the phase of the signal generated by the HPF process, and as a result, the suppression effect is reduced.

  Therefore, in step S11, a phase compensation process is performed to compensate for a phase change caused by the HPF process. In step S12, an amplitude adjustment coefficient is extracted using a focal length acquired by a focal length detection unit (not shown) and a table stored in the CPU 21, and this coefficient is multiplied by the data generated up to step S11. Control data for controlling the image blur correction lens group 25 is generated.

  Then, the control data generated in step S13 is output to the D / A converter 22. Finally, in step S14, the centering flag is confirmed. If the centering flag is cleared, the process returns to step S7 again, and the correction lens control processing in steps S7 to S14 is repeated.

  On the other hand, if the position change amount ΔP is greater than or equal to the threshold value in step S9, it is assumed that the operator of the tripod 10 has performed the panning operation, and the process proceeds to step S16 to set the centering flag. Subsequently, in step S17, position data of the image blur correction lens group 25 output from the position detector 26 via the A / D converter 27 is acquired, and in step S18, the correction lens group is used using this position data. Control data for centering 25 is generated.

  When the panning operation is performed, the image blur correction lens group 25 is largely moved until the position change amount ΔP is recognized as a vibration until it is determined by software, and the image blur correction lens group 25 is moved to the end position of the movable range. There is a possibility of reaching.

  When the image blur correction lens group 25 reaches the end position, normal control cannot be performed, so that centering processing is required. This centering is to control the image blur correction lens group 25 to the center position in the movable range. In step S18, the position data acquired in step S17 is compared with the center position, and control data that moves to the center position at a constant speed is calculated. The control data generated in step S18 is output to the D / A converter 22 in step S13, and the process proceeds to step S14.

  In step S14, since the centering flag is set, the process proceeds to step S15. In step S15, it is determined from the correction lens position data acquired in step S17 whether the image blur correction lens group 25 has completed centering. If the centering has not been completed, the process returns to step S17, and the centering process is repeated. If the centering has been completed, the process returns from step S15 to S2, and the correction lens control initialization process is performed again.

  FIG. 3 is a block circuit configuration diagram of the second embodiment. The same reference numerals as those of the first embodiment denote the same devices. An angular velocity sensor 31 that detects vibration applied to the zoom lens unit 20 as an angular velocity is provided, and an output of the angular velocity sensor 31 is connected to the CPU 21 through an HPF circuit 32, an arithmetic circuit 33, and an A / D converter 34 in order. . The output of the CPU 21 is connected to the HPF circuit 32. Further, the output of the control changeover switch 35 is connected to the CPU 21.

  The HPF circuit 32 removes a DC component contained in the output signal of the angular velocity sensor 31, the arithmetic circuit 33 converts a signal corresponding to the angular velocity into an angular signal, and the A / D converter 34 is an analog signal output from the arithmetic circuit 33. Is converted to a digital signal. The control changeover switch 35 selects whether to use the signal of the panning detection means 11 of the tripod 10 or the signal of the angular velocity sensor 31 of the zoom lens unit 20 for image blur correction control.

  FIG. 4 is a flowchart showing an example of software processing in the CPU 21. Although only the panning direction will be described as in the first embodiment, the same processing is performed in the tilting direction, and the same step numbers as those in the flowchart of FIG. 2 perform the same processing.

  When the CPU is initialized in step S1, the state of the control changeover switch 35 is determined in step S21. When the switch state is “tripod”, that is, when the control is performed using the output of the panning detection means 11, the correction lens control initialization process in steps S <b> 2 to S <b> 6 similar to the first embodiment is performed.

  On the other hand, when the switch state is “lens”, that is, when control is performed using the output of the angular velocity sensor 31, initialization processing of correction lens control in steps S22, S23, S24, and S6 is performed. Step S22 is a process of resetting the HPF circuit 32 on hardware, and is performed by controlling the analog switch (not shown) mounted in the HPF circuit 32 by the CPU 21. In steps S23 and S24, HPF processing for calculating the output of the angular velocity sensor 31 and reset processing of phase compensation processing are performed. In step S6, the centering flag is cleared.

  When the initialization of the correction lens control is completed, the state of the control selector switch 35 is determined in step S25. If the control switch 35 is “tripod”, the process proceeds to step S7, and if it is “lens”, the process proceeds to step S26. When the process proceeds to step S7, the same processes of steps S7 to S14 as in the first embodiment are performed.

  In step S25, the vibration angle Δθ output from the A / D converter 34 when the process proceeds to step S26 is acquired and compared with a threshold value in step S27. Similar to step S9, this process is also a process for determining whether or not the tripod operator has performed a panning operation. When the panning operation is performed, the angular velocity sensor 31 detects a very large vibration. The presence / absence of panning operation is determined based on the amplitude.

  The threshold is set to the minimum vibration angle at which it can be determined that a panning operation has been performed. Similar to the control by the panning detection means 11, the panning operation may be determined by both the frequency of the vibration angle Δθ and the amplitude and frequency of the vibration angle Δθ.

  In step S27, when the vibration angle Δθ is smaller than the threshold value, the vibration angle Δθ is regarded as vibration data, and the process proceeds to steps S28, S29, and S30, and HPF processing, phase compensation processing, amplitude based on the output of the angular velocity sensor 31 is performed. Adjustment processing is performed to generate control data, which is output to the D / A converter 22 in step S13. Then, the processes of steps S25 to S30, S13, and S14 are repeated until the state of the control switch 35 changes to “tripod” in step S25, or the vibration angle Δθ becomes equal to or larger than the threshold value in step S27.

  On the other hand, when the vibration angle Δθ is equal to or larger than the threshold value in step S27, it is assumed that the panning operation intended by the tripod operator is performed, the process proceeds to step S16, and the centering process described in the first embodiment is performed. When the centering process is completed, the process proceeds from step S15 to S21, and the correction lens control process is performed again.

  In the second embodiment, the angular velocity sensor 31 is used as the vibration detection means mounted in the lens, but other vibration detection means may be used. In the second embodiment, the control changeover switch 35 is used. Instead of the control changeover switch 35, the CPU 21 performs software processing from the outputs of the panning detection means 11 and the A / D converter 34 to determine the photographing state. Then, control switching may be performed automatically.

1 is a block circuit configuration diagram of Embodiment 1. FIG. FIG. 3 is an operation flowchart of the first embodiment. 6 is a block circuit configuration diagram of Embodiment 2. FIG. FIG. 6 is an operation flowchart of the second embodiment.

Explanation of symbols

10 Tripod 11 Panning Detection Unit 20 Zoom Lens Unit 21 CPU
DESCRIPTION OF SYMBOLS 22 D / A converter 23 Drive circuit 24 Actuator 25 Image blur correction lens group 26 Position detector 27 A / D converter 31 Angular velocity sensor 32 HPF (high pass filter) circuit 33 Arithmetic circuit 34 A / D converter 35 Control changeover switch

Claims (6)

  The operation angle includes a tripod having an operation angle detection means for detecting a movement amount of panning and tilting, and a zoom lens unit having an image shake correction lens group and a correction lens drive means for driving the image shake correction lens group. An image blur correction lens apparatus that controls the image blur correction lens group via the correction lens driving unit according to an output of a detection unit.   A tripod having an operation angle detection means for detecting a movement amount of panning and tilting; an image blur correction lens group; a correction lens driving means for driving the image blur correction lens group; and a zoom lens section having a vibration detection means; An operation angle detection unit or a selection unit that selectively selects the vibration detection unit, and the selection of the selection unit causes the output of the operation angle detection unit or the output of the vibration detection unit to pass through the correction lens driving unit. And an image blur correction lens group that controls the image blur correction lens group.   The image blur correction lens apparatus according to claim 2, wherein the vibration detection unit is an angular velocity sensor.   The image blur correction lens device according to claim 2, wherein the selection unit is a changeover switch.   In a lens that corrects the image blur of the zoom lens unit using the image blur correction lens group, a panning and tilting movement amount is detected by an operation angle detection unit provided on a tripod, and if the movement amount is smaller than a threshold value, Image blur correction control by an image blur correction lens group is performed, and if the movement amount is larger than a threshold value, centering processing is performed to control the image blur correction lens group to a center position. Method.   6. The image blur correction lens apparatus correction method according to claim 5, wherein the threshold value is a minimum movement amount that allows an operator to determine whether the movement amount is intentionally changed.

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