JPH06105966B2 - Imaging device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photographing device such as a video camera, and in particular,
The present invention relates to an image pickup apparatus having a vibration isolation function that can obtain a stable image even when the image pickup apparatus main body is subjected to disturbance vibration or swing.

2. Description of the Related Art In recent years, the performance of video equipment has been remarkably improved, and high-quality images have become extremely easy to obtain. Along with this, sophisticated photography techniques are required. Against such a background, there has been proposed an image pickup apparatus having an image stabilization function capable of obtaining a stable image with little screen shake regardless of the shake of the photographer and the image pickup apparatus.

Hereinafter, a conventional imaging apparatus having a vibration isolation function will be described with reference to the drawings. FIG. 13 is a block diagram showing a conventional image pickup apparatus having a vibration isolation function. Reference numeral 1301 is a lens barrel portion on which a plurality of lenses and a photographing element are mounted. 1302 is the lens barrel
The counterweight for 1301 is mechanically coupled to the lens barrel 1301 by a connecting rod 1303. Reference numeral 1305 is a joint that rotatably connects the connecting rod 1303 and the support rod 1304. The photographer operates the photographing apparatus by supporting the support rod 1304. In the above configuration, the counterweight 1302 is adjusted so that the center of gravity of the movable portion 1306 composed of the lens barrel 1301, the connecting rod 1304, and the counterweight 1302 is located near the joint 1305.

Then, the movable portion 1306 has a large moment of inertia around the joint 1305. Therefore, even if the support bar 1304 supported by the photographer is tilted by some disturbance, the posture of the movable portion 1306, that is, the lens barrel portion 1301 is kept constant without tilting due to the action of the moment of inertia of the movable portion 1306. . Therefore, it is possible to obtain a stable image with little screen shake even when the photographer swings (for example, John Jurgens, "Design of Steadicam" S.M.
P.T.E.Journal Vol. 87, Sep. 1978, p. 587 (John Jurgens "Steadicam as a Design Problem
m ”, SMPTE jounal Vol.87, Sep, 1978, P587)].

Problems to be Solved by the Invention However, in the conventional configuration as described above, it is necessary to provide an extremely large counterweight 1302. Therefore, it is difficult to reduce the size and weight of the conventional configuration, which is not suitable for a portable video camera.

Means for Solving the Problems In order to solve the above-mentioned problems, a photographing apparatus of the present invention provides a lens barrel part having a plurality of lenses and a photographing element, and an image signal from an electric signal obtained by the photographing element. Image signal processing means to generate, a support body for rotatably supporting the lens barrel portion around a rotation axis that is orthogonal or substantially orthogonal to an axis of an incident light beam on the lens barrel portion, and the lens barrel portion and the support body. An actuator means that is mounted between and that drives the lens barrel to rotate;
Relative angle detection means for detecting a relative angle between the lens barrel portion and the support, lens barrel angular velocity detection means for detecting an angular velocity of the lens barrel portion with respect to the space around the rotation axis, and the actuator according to a command signal. Drive means for supplying electric power to the means, a load for estimating the magnitude of a disturbance load applied to the lens barrel portion based on an output signal of the lens barrel angular velocity detecting means and a command signal of the driving means, and outputting a load estimation signal. Observation means,
The output of the relative angle detecting means and the output of the lens barrel angular velocity detecting means, and a combining means for generating and outputting a combined signal, the input of the drive means from the combined signal output from the combining means The above-mentioned object is achieved by configuring so that the command signal obtained by subtracting the load estimation signal is input.

Operation The present invention controls the lens barrel so as to be stationary or substantially stationary in the inertial coordinate by the above-mentioned configuration. Therefore, a stable image with less screen shake can be obtained irrespective of the swing of the photographer and the photographing apparatus, and the photographing apparatus that can be reduced in size and weight can be provided.

Embodiment An image pickup apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an image pickup apparatus in one embodiment of the present invention. In FIG. 1, a large number of lens groups (not shown) and a photographing element 2 (for example, CCD
A plate or a photographing tube) is attached to collect reflected light from a subject to form an image on the photographing element 2 and a charge signal (electric signal)
Convert to. The image signal processing circuit 10 sequentially reads out the charge signal obtained by the image pickup device 2 to obtain an image signal (video signal).
Is producing.

An actuator 5 is arranged between the lens barrel portion 1 and the support body 3, and the lens barrel portion 1 is rotationally driven about the rotation shaft 6 in the yaw direction. The rotation shaft 6 of the actuator 5 is the lens barrel 1
It is rotatably supported by the support body 3 through the center of gravity G of. The actuator 5 is provided with a projection 17, and the support 3 is provided with stopper pins 18a and 18b. The protrusion 17 and the stopper pins 18a and 18b regulate the movable range of the lens barrel portion 1 in the yaw direction. Further, the support 3
There is provided a grip portion 4 which is manually supported by the operator of the photographing apparatus.

2 (a), (b), and (c) show a specific configuration of the actuator 5. In FIG. 2, the ferromagnetic back yoke 201 of the magnet 202 is attached to the lens barrel 1 and rotates together with the rotary shaft 6. The magnet 202 is magnetized to have four poles and generates a magnetic field flux. Bearing of rotating shaft 6
On the coil yoke 203 to which 207 is attached, the coil 204
The a and 204b and the Hall element (magnetic sensing element) 9 are fixed.
In this example, the magnet 202 is attached to the lens barrel 1,
The coil yoke 203 is attached to the support 3. The coils 204a and 204b are connected in series, and a rotational torque is generated by the current flowing from the terminals 205 to 206 and the magnetic flux of the magnet 202. The Hall element 9 is arranged substantially opposite to the magnetic pole switching portion of the magnet 202, and
2 (angle θm of lens barrel 1) and coil yoke 203 (support 3
The output signal corresponding to the relative angle difference θmo (= θo−θm) of the angle θo of is generated. Note that θm is the angle of the lens barrel portion 1 around the rotation axis 6 as viewed from the space (inertia coordinate), and θo is the angle of the support 3 around the rotation axis 6 as viewed from the same inertial coordinate.

The output signal a of the Hall element 9 that detects the magnetic flux of the magnet 202 of the actuator 5 is input to the relative angle detection circuit 11. FIG. 3 shows a specific configuration of the relative angle detection circuit 11. The DC signal obtained at the two output terminals of the hall element 9 is differentially amplified by a predetermined multiple by the differential amplifier circuit including the operational amplifier 301 and the resistors 302, 303, 304, 305 to obtain the output signal c. + _V H, -V _H is a suitable power source, the resistor 30
An appropriate bias voltage is applied to the Hall element 9 via 6,307.

Further, the angular velocity sensor 7 composed of a vibration type gyro is attached to the lens barrel portion 1 by a fixing member 8. The detection axis of the angular velocity sensor 7 coincides with the rotation axis 6 of the actuator 5, and outputs the output signal b in response to the rotation angular velocity around the rotation axis 6 of the lens barrel 1 in the inertial coordinate. The output signal b of the angular velocity sensor 7 is input to the angular velocity detection circuit 12,
Angular velocity ω around the rotation axis 6 of the lens barrel 1 viewed from the inertial coordinates
A signal d proportional to m is obtained. FIG. 4 shows a specific configuration of the angular velocity detection circuit 12. The forced vibration circuit 401 has a sine wave oscillating circuit of a predetermined frequency (for example, 1 kHz), and the drive element 402 made of the piezoelectric element of the angular velocity sensor 7 is forcibly vibrated by the oscillating frequency signal. Since the sense element 403 made of a piezoelectric element is arranged in mechanical contact with the drive element 402, it vibrates at the same frequency as the drive element 402. At this time, when the lens barrel unit 1 rotates about the rotation axis 6 in the inertial coordinate, a mechanical Coriolis force is generated. Since the Coriolis force is proportional to the product of the angular velocities of the two orthogonal axes of the sense element 403, it is proportional to the product of the angular velocity ωm around the rotation axis 6 of the lens barrel portion 1 in inertial coordinates and the angular velocity due to forced vibration. Sense element 403
Generates mechanical strain due to Coriolis force, and generates an electric signal due to piezoelectric action. The output of the sense element 403 is synchronously detected by the synchronous detection circuit 404 at the same frequency as the forced vibration, and the low-pass filter 405 extracts the low-frequency component (for example, DC to 100 Hz) of the detected output. Angular velocity ωm around the rotation axis 6 of 1
A signal d proportional to is obtained.

The output signal c of the relative angular velocity detection circuit 11 and the output signal d of the lens barrel angular velocity detection circuit 12 are input to the combining means 14. The synthesizing means 14 adds the output signal d of the lens barrel angular velocity detection circuit 12 and the result of the integral calculation of the output signal c of the relative angle detection circuit 11 with a predetermined gain, and outputs the calculation result as an output signal e. To do.

FIG. 5 shows the configurations of the load observer 13 and the synthesizing means 14. In this embodiment, the load observing device 13 and the synthesizing means 14 are A / D converters 50.
2, 503, arithmetic unit 501, memory 504, and D / A converter 505. The A / D converter 502 produces a digital signal p corresponding to the value of the output signal c of the position detection circuit 11.
Further, the A / D converter 503 outputs the output signal d of the angular velocity detection circuit 12.
A digital signal q corresponding to the value of is generated. The arithmetic unit 501 operates according to a predetermined built-in program, which will be described later, stored in the ROM area (read only memory area) of the memory 504, and the digital signal p and A / D of the A / D converter 502.
The digital signal q of the D converter 503 is taken into the RAM area (random access memory area), subjected to a predetermined calculation and then combined, and the combined digital signal w is output to the D / A converter 505.

FIG. 6 shows a specific configuration of the A / D converter 502 (the same applies to the A / D converter 503). The input signal c and the output signal m of the D / A conversion circuit 607 are compared by the comparator 601, and the comparator signal n corresponding to the magnitude relation is obtained.
The oscillator circuit 605 generates a clock pulse 1 having a predetermined frequency. The signal h from the calculator 501 is normally "H" (high potential state), and becomes "L" (low potential state) when the digital signal p is read. Therefore, the inverter circuit 602 and the AND circuits 603 and 604 are connected to the comparator signal n.
Accordingly, the clock pulse 1 is input to the down pulse input terminal D or the up pulse input terminal U of the counter circuit 606 (when the signal h is "H"). Counter circuit 606
The internal state is decremented by 1 by the input pulse to the down pulse input terminal D, and the internal state is incremented by 1 by the input pulse to the up pulse input terminal U. The internal state of the counter circuit 606 is output as a digital signal p, and is converted into an analog signal m according to the digital signal p in the D / A converter 607. As a result, the counter circuit
The digital signal p of 606 becomes a value corresponding to the input signal c. The arithmetic unit 501 sets the signal h to "L" for a predetermined short time to stop the operation of the counter circuit 606 and read a stable digital signal p. Similarly, the calculator 501
Makes the signal k "L" for a predetermined short time so that a stable digital signal q is read.

The output signal u of the control calculation means 15 is input to the drive circuit 16,
A voltage signal (or current signal) f proportional to the signal u is supplied to the coils 204a and 204b of the actuator 5. 7th
The figure shows a specific configuration of the drive circuit 16. Operational amplifier 701
The transistors 704 and 705 and the resistors 702 and 703 form a power amplifier circuit, which outputs a voltage signal f obtained by amplifying the signal e by a predetermined factor.

Now, the built-in program of the arithmetic unit 501 will be described.
First, an outline will be described based on the basic flowchart shown in FIG.

In process 801, an interrupt from the timer is awaited.
The timer generates an interrupt signal at every predetermined time TS,
When an interrupt occurs, moves to. That is, the following processing is performed at the sampling time TS.

In process 802, the digital signal p corresponding to the relative angle θmo between the lens barrel 1 and the support 3 is fetched from the A / D converter 502 and stored in the memory 504. Further, the digital signal q corresponding to the angular velocity ωm viewed from the inertial coordinate of the lens barrel 1 is given by A /
It is fetched from the D converter 503 and stored in the memory 504.

In process 804, control calculation is performed so that the lens barrel unit 1 is stationary or substantially stationary in the inertial coordinate, and the combined signal e is produced. After this processing, shifts to.

In process 805, the angular velocity ωm seen from the inertial coordinate of the lens barrel unit 1
Corresponding to the digital signal q and the input signal u of the drive circuit 16
Then, a load estimation signal t corresponding to the magnitude of the disturbance load applied to the lens barrel portion 1 is calculated and output. Then, the command signal u obtained by subtracting the load estimation signal t from the combined signal e obtained in the process 804 is produced.

The processing 804 and the processing 805 are control calculation means in FIG.
Equivalent to 15.

Next, the processes 802 to 805 will be described in detail with reference to FIG.

FIG. 9A is a detailed flowchart of the process 802. First, the content of the variable Qn holding the value of the digital signal p corresponding to the relative angle θmo between the lens barrel 1 and the support 3 at the previous sampling is stored in the variable Qn−1. Next, the signal h is set to “L”, a digital signal p corresponding to the relative angle θmo between the lens barrel 1 and the support 3 is newly fetched and stored in the variable Qn, and then the signal h is set to “H” again.

Further, the content of the variable Wn holding the value at the time of the previous sampling of the digital signal q corresponding to the angular velocity ωm of the lens barrel portion 1 is stored in the variable Wn−1. Next, the signal k is set to “L”, a digital signal q corresponding to the angular velocity ωm of the lens barrel unit 1 is newly fetched and stored in the variable Wn, and then the signal k is set to “H” again.
To That is, at this time, the information of the relative angle θmo between the current barrel 1 and the support 3 is stored in the variable Qn, and the information of the angular velocity ωm of the barrel 1 is stored in the variable Wn. Furthermore, the information before each sampling is Qn-
1 and the variable Wn-1.

FIG. 9B is a detailed flowchart of the process 804. First, the variable En holding the value of the digital signal w corresponding to the output signal e of the synthesizing means 14 one sampling before is stored in the variable En-1. Next, from the variable Qn that holds a value corresponding to the current relative angle θmo between the lens barrel 1 and the support 3, the relative angle θmo between the lens barrel 1 and the support 3 one sampling before.
The variable Qn−1 holding the value corresponding to is subtracted and the result is stored in the variable ΔQ. Then, the variable Wn-1 holding the value corresponding to the angular velocity ωm of the lens barrel unit 1 before one sampling is subtracted from the variable Wn holding the value corresponding to the current angular velocity ωm of the lens barrel 1, The result is stored in the variable ΔW.
Then, the following calculation (2) is performed using K1, K2, Ta, and TS as constants, and the calculation result is stored in the variable ΔE.

ΔE = −K1 × ΔW + K2 × (ΔQ + TS × Qn / Ta) (2) Next, the variable ΔE and the variable En−1 are added, and the result is newly stored in the variable En. After that, move to and process the next stage
After 805, it waits for a timer interrupt (see Fig. 8).

Although a detailed description of the process 805 will be given later, first, the control operation and the image stabilization effect during still shooting when the process 805 is not performed will be described in detail.

FIG. 10 is a control block diagram of the image pickup apparatus in this embodiment during still image pickup. In the figure, S represents a Laplace operator. Further, in the figure, the delay element due to sampling and the frequency dependence of the low-pass filter 405 of the lens barrel angular velocity detection circuit 12 can be sufficiently ignored in the frequency region described below, and thus are omitted. Now, the angle θm of the lens barrel 1 and the angle θ of the support 3 as seen from the inertial coordinates.
The relative angle θmo of o is determined by the magnet 20 of the actuator 5.
It is easily detected by the Hall element 9 which detects the magnetic field of 2. Hall element 9 and relative angle detection circuit 11 are block 10
A signal c (an output signal of the position detection circuit 11), which is represented by 01 and is K _Q · A _Q times θmo, is obtained. K _Q is the magnetic flux density / voltage conversion gain of the Hall element 5, and A _Q is the relative angle detection circuit 11
Is the voltage gain of. On the other hand, the angular velocity ωm of the lens barrel 1 viewed from the inertial coordinates is detected by the angular velocity sensor 7 and the angular velocity detection circuit 12, and is represented by a block 1008.
A signal d of _W · A _W times is obtained. K _W is the angular velocity / voltage conversion gain of the angular velocity sensor 7, and A _W is the voltage gain of the angular velocity detection circuit 12. Further, the signal c is multiplied by K2 (block 1002) by the processing 804 (corresponding to a portion surrounded by a broken line) of the arithmetic unit 501, and the result and the result are integrated with a gain of 1 / Ta (block 1003). And the signal d multiplied by −K1 (block 1009) are combined at the addition point 1010,
Obtain the combined signal e. Block 1004 corresponding to drive circuit 16
At, the signal e is amplified Ae times to obtain the voltage signal f. In the block 1005 corresponding to the actuator 5, the voltage signal f is converted into the torque Tm. Here, R is a combined resistance value of the coils 204a and 204b, and Kt is a torque constant. A block 1006 represents the transmission from the torque Tm to the angular velocity ωm due to the mechanical moment of inertia Jm of the lens barrel portion 1, and a block 1007 represents the relationship between ωm and θm. Therefore, the transfer characteristic from θo to θm from this block diagram is as shown in FIG. 11th
In the figure, fr is the fluctuation frequency of θo. Here, the frequencies f1 and f2 at the break points can be expressed as follows using the respective gain constants shown in FIG.

Actually, f1 = 0.18Hz and f2 = 10Hz are set. And
The transfer characteristic of the rotation angle θm of the lens barrel portion 1 with respect to the rotation angle θo of the support 3 in the inertial coordinate is 1 (0 dB) in the frequency range of the first break point frequency f1 or lower, and the transfer characteristic of the second bend point f1 or higher. It is attenuated at -6 dB / oct in the frequency range below the point frequency f2, and is attenuated at -12 dB / oct in the frequency range above f2. From FIG. 11, the amount of transmission from the vibration of θo to the vibration of θm becomes small in the frequency range of f1 and above. The extent is represented by the difference ZdB between 0 dB and the characteristic line (in this case at fr = 1 Hz Z = 15 dB).

The fluctuation of the shooting device during still shooting is mainly 0.5Hz to 5Hz
It is known to be distributed in the range of. Therefore, if the vibration-proof characteristics of the present photographing device are set to the characteristics as shown in FIG. 11, the barrel portion 1 will be irrespective of the fluctuation of the rotation angle θo of the support body 3.
It can be seen that the rotation angle θm of 1 is almost unchanged, and the fluctuation of the shooting screen is significantly reduced. That is, stable and easy-to-view video shooting becomes possible.

In addition, each term in the mixing operation (2) has the following meaning depending on the processing (En = En-1 + ΔE) in the next stage.

That is, the first term [−K1 × ΔW] in the equation (2) is a component provided for setting the angular velocity ωm of the lens barrel portion 1 to “0” and keeping the lens barrel portion 1 stationary in the inertial coordinates. The term [K2 × ΔQ) in the second term of the equation (2) is the angle θm in the inertial coordinate of the lens barrel 1 and the inertial coordinate of the support 3 when the relative angle θmo between the lens barrel 1 and the support 3 is “0”. The angle θo at is a component provided to make the states substantially coincide. Where gain K2 is gain K1
It is set to be much smaller than. This is because the main purpose is to set the angular velocity ωm of the lens barrel portion 1 to “0”. That is, when K2 is increased, the followability of the angle θm of the lens barrel portion 1 with respect to the angle θo of the support 3 is improved, and the vibration isolation effect is reduced. Therefore, the value of K2 is selected to be sufficiently small, and the torque Tm generated by the actuator 5 according to the term [K2 × ΔQ] is small. Therefore, when the loss around the bearing of the actuator 5 is large, the generated torque Tm
Does not reach the loss, and the relative angle θmo between the lens barrel portion 1 and the support body 3 does not reach “0”. That is, the lens barrel portion 1
The control of ωm = 0 is performed with a steady deviation between the angle θm and the angle θo of the support body 3. Therefore,
The term [K2 × ΔT × Qn / Ta] in the second term of the equation (2) is provided, and θmo is set in addition to the next-stage processing [En = En-1 + ΔE].
Has the meaning of the integral calculation of the angle θm of the lens barrel 1 and the support 3
The stationary deviation of the angle θo of is removed. That is, θo
If there is a steady deviation between θm and θm, the term [K2 × ΔT × Qn × Ta] is added to the variable En for each sampling.
As a result, even when the torque generated by the actuator 5 according to the term [K2 × ΔQ] is smaller than the bearing loss, the term [K2 × ΔT × Qn / Ta] is added to En for each sampling, The torque generated by the actuator 5 increases with time and exceeds the bearing loss, and the steady deviation between θo and θm can be eliminated.

However, the problems to be described below became clear during repeated examinations for actually realizing the imaging apparatus of the present invention.

That is, viscous friction generated between the rotating shaft 6 and the bearing 207 provided for rotatably supporting the lens barrel 1 and the support 3 and the image pickup device 2 and the support 3 attached to the lens barrel 1. Due to the rigidity of several tens of wire rods connected to the image signal processing circuit 10 provided in the above, sufficient vibration isolation characteristics cannot be obtained. Both the viscous friction of the bearing portion and the rigidity of the wire material become the disturbance torque TD (FIG. 10) applied to the lens barrel portion 1, and moreover, they act to rotate the lens barrel portion 1 in accordance with the movement of the support body 3. Therefore, equivalently, from the angle θo of the support 3
In the transfer characteristic to the angle θm of the first break point frequency f1
Will move to the high frequency side (f1 = 2-3 Hz). As a result, as described above, the fluctuations of the shooting device during still shooting are mainly distributed in the range of 0.5Hz to 5Hz, so sufficient vibration damping characteristics can be obtained when the viscous friction of the bearing and the rigidity of the wire are large. It will not be possible.

In the present invention, in order to solve the above problems, the disturbance load TD applied to the lens barrel portion 1 is changed from the output d of the lens barrel angular velocity detection circuit 12 and the input u of the drive circuit 16 by the load observer 13 shown in FIG. The disturbance load TD is estimated, and the output t of the load observer 13 is combined with the output e of the combining means 14 so as to cancel the disturbance load TD applied to the lens barrel 1.
Is subtracted by a subtracter 19.

The principle of the present invention is briefly described as follows.

When there is no disturbance, the angular velocity of the lens barrel portion 1 should be proportional to the integral of the input u of the drive circuit 16. It is considered that the non-proportionality is due to disturbance, so conversely, the lens barrel angular velocity detection circuit
The disturbance load TD can be estimated by comparing the output d of 12 and a signal obtained by multiplying the integrated value of the input u of the drive circuit 16 by a predetermined value.

Hereinafter, the operation of the load observer 13 of FIG. 1 will be described in detail.

FIG. 12 (a) shows a block diagram of the load observer 13. The generated torque Tm of the actuator 5 is obtained by multiplying the command signal u input to the drive circuit 16 by Ae · Kt / R (block 1201). Angular velocity ωm of barrel 1 and its estimated angular velocity The difference signal α is obtained by the subtractor 1216. Further, the difference signal is multiplied by Jm · G1 (block 1212) to obtain the signal β. In addition, the difference signal α is integrated (block 1213) to obtain the signal ν,
Estimated disturbance load by further doubling Jm · G (block 1214) To get Next, the torque Tm generated by the actuator 5, the signal β, and the estimated disturbance load Are added by the adder 1215 to obtain the signal δ. Further, the signal ε is obtained by integrating the signal δ (block 1211), and is further multiplied by 1 / Jm to estimate the estimated angular velocity of the lens barrel 1. To get Therefore, the estimated disturbance load obtained by the above loop Estimated disturbance load by multiplying R / Kt / Ae times (block 1202) It is possible to obtain the input t of the drive circuit 16 necessary to generate the magnitude of

Next, the operation of the part surrounded by the broken line in FIG. 12 (a) will be described.

In the block diagram of FIG. 12 (a), the input position of the angular velocity ωm of the lens barrel portion 1 is equivalently converted to organize the block diagram, which results in FIG. 12 (b). Input x in Fig. 12 (b) is
It is expressed as follows from Fig. 12 (a).

x = Tm−ωm · JmS (5) Paying attention to the adder 1011 in FIG. 10, the signal x expressed by the equation (5) is the disturbance load TD applied to the lens barrel 1 with a negative sign. equal. Therefore, from the block diagram of FIG. 12 (b), the estimated disturbance load from the disturbance load TD applied to the lens barrel 1 is estimated. When the transfer functions up to are obtained, the following equation is obtained.

From the equation (6), the actual disturbance load TD is estimated in the second-order lag system from the angular velocity ωm of the lens barrel 1 and the command signal u of the drive circuit 16 by the loop of the portion surrounded by the broken line in FIG. 12 (a). You can do it.

Therefore, if the natural frequency of the second-order lag system is fn and the damping factor is ζ, then G1 = 2ζ (2πfn) (7) G2 = (2πfn) ² (8) As described above, since the fluctuations of the image capturing device during still shooting are mainly distributed in the range of 0.5 Hz to 5 Hz, it is considered that the frequency of the disturbance load TD is also distributed in the range of 0.5 Hz to 5 Hz (7 ) And fn in equation (8)
The disturbance load TD can be estimated extremely accurately by selecting 5 Hz and ζ between 0.7 and 1. The above calculation is executed by the process 805 shown in FIG.

Next, the process 805 will be described in detail with reference to the flowchart of FIG.

First, a variable Tn that holds the value of the digital signal T corresponding to the output signal t of the load observer 13 one sampling before is set as a variable.
Stored in Tn-1 and similarly estimated angular velocity of lens barrel 1 A variable that holds the value corresponding to To store. Next, the estimation of the lens barrel portion 1 is performed from the variable Wn−1 that holds the value corresponding to the angular velocity ωm of the lens barrel portion 1 before one sampling. Is subtracted and the result is stored in the variable ΔA. And G
The following calculations (9) and (10) are performed with 1, G2, TS as constants, and the calculation results are variables. Stored in.

Next, And add To store. And from variable En to variable Is subtracted and the result is newly stored in Un. And finally,
The content of the variable Un is output to the D / A converter 505 as a signal w (see FIG. 5). After that, the process shifts to and waits for a timer interrupt (see FIG. 8).

In the above description, the embodiment of the present invention is applied to the shake prevention in the yaw direction and the pan photographing, but it goes without saying that the invention can also be applied to the shake prevention in the pitch direction and the tilt photographing. Further, the application range of the present photographing device is not limited to the video camera, and various modifications can be made without changing the gist of the present invention.

EFFECTS OF THE INVENTION As described above, the anti-vibration mechanism of the image pickup apparatus of the present invention does not require the counterweight of the lens barrel portion required in the conventional example, and can be reduced in size and weight. Moreover, the number of sensors is small and the cost is low. In addition, Hall element (magnetic sensitive element) that detects the magnetic field of the actuator magnet
Since the relative position is detected by, the configuration is simple and the number of parts is small. Furthermore, since the disturbance load applied to the lens barrel can be estimated by the load observer in the imaging apparatus of the present invention, the disturbance load can be canceled by the signal obtained by the load observer.

Therefore, according to the present invention, if, for example, a video camera is configured, a video camera with a small, lightweight, and high-performance anti-vibration mechanism can be easily obtained, and viscous friction generated between the rotary shaft and the bearing, and a mirror. Sufficient anti-vibration characteristics can be obtained even if the wire that connects the image pickup device attached to the tubular portion and the image signal processing circuit provided on the support has a large rigidity. Moreover, no adjustment is necessary because it can automatically follow the change in the magnitude of the disturbance load.

[Brief description of drawings]

FIG. 1 is a block diagram of a photographing device according to an embodiment of the present invention,
2 (a), (b), and (c) are configuration diagrams showing a specific configuration of the actuator of FIG. 1, and FIG. 3 is a circuit showing a specific configuration of the relative angle detection circuit of FIG. 4 and FIG. 4 are configuration diagrams showing a specific configuration of the lens barrel angular velocity detection circuit of FIG. 1, and FIG. 5 is a configuration diagram showing a specific configuration of the load observer and the synthesizing unit of FIG. FIG. 6 is a configuration diagram showing a specific configuration of the A / D converter of FIG. 5, FIG. 7 is a circuit diagram showing a specific configuration of the drive circuit of FIG. 1, and FIG. 8 is FIG. Memory of ro
A basic flowchart of the built-in program stored in the M area, FIGS. 9 (a), 9 (b), and 9 (c) are detailed flowcharts of the respective processes of FIG. 8, and FIG. 10 describes the operation of FIG. 11 is a Bode diagram for explaining the operation of FIG. 1, and FIGS. 12 (a) and 12 (b) are blocks for explaining the operation of the load observer of FIG. Figure, thirteenth
FIG. 1 is a block diagram of a conventional photographing device. 1 ... Lens barrel, 3 ... Support, 5 ... Actuator,
6 ... Rotation axis, 7 ... Angular velocity sensor, 9 ... Hall element, 10 ... Image signal processing circuit, 11 ... Relative angle detection circuit, 12 ... Lens barrel angular velocity detection circuit, 13 ... Load observer ,
14 ... Combining means, G ... Center of gravity of lens barrel 1, 16 ... Driving circuit, 501 ... Computing unit, 502, 503 ... A / D converter, 504 ... Memory, 505 ... D / A converter .

Claims (4)

[Claims] 1. A lens barrel portion having a plurality of lenses and a photographing element mounted thereon, image signal processing means for generating an image signal from an electric signal obtained by the photographing element, and an axis of an incident light beam to the lens barrel portion. A support body that rotatably supports the lens barrel portion around rotation axes that are substantially orthogonal to each other, an actuator unit that is mounted between the lens barrel portion and the support body, and that rotationally drives the lens barrel portion, and the mirror. Relative angle detection means for detecting the relative angle between the tubular portion and the support, lens barrel angular velocity detection means for detecting the angular velocity of the lens barrel portion with respect to the space around the rotation axis, and the actuator means in response to a command signal. Load observing means for estimating the magnitude of the disturbance load applied to the lens barrel portion based on the driving means for supplying electric power, the output signal of the lens barrel angular velocity detecting means and the command signal of the driving means, and outputting the load estimation signal. And before The output signal of the relative angle detecting means and the synthesizing means for generating and outputting a synthetic signal from the output of the lens barrel angular velocity detecting means are provided, and the command signal input to the driving means is the load estimation signal from the synthetic signal. An image pickup apparatus, which is configured to be obtained by subtracting. 2. The photographing apparatus according to claim 1, wherein the rotation axis of the actuator section passes through the center of gravity of the lens barrel section or in the vicinity of the center of gravity. 3. An image pickup apparatus according to claim 1, wherein an angular velocity sensor using a vibrating gyro is used as the angular velocity detecting means. 4. The transfer characteristic of the rotation angle of the lens barrel portion with respect to the rotation angle of the support in space is set to 1 in the frequency range of the first break point frequency f1 or lower, and at the f1 or higher, the second break point frequency f2 ( −6 dB / oc in the frequency range below f1 <f2)
The photographing device according to claim (1), characterized in that it is attenuated at t and is attenuated at −12 dB / oct at f2 or more.