JPH0734582B2 - 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 this background, there has been proposed an image pickup apparatus having a vibration-proof function capable of obtaining a stable image with little screen shake regardless of the vibration 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 denotes a lens barrel portion on which a plurality of lenses and an image sensor 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 lens barrel 1301, the connecting rod 1304, the counterweight 1302
The counterweight 1302 is adjusted so that the center of gravity of the movable portion 1306 configured by 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 movable portion 1306 is acted by the action of the moment of inertia of the movable portion 1306.
That is, the posture of the lens barrel 1301 is kept constant without tilting. Therefore, it is possible to obtain a stable image with little screen shake even when the photographer swings. (For example, Jun Jurgens, "Design of Steadicam", SMP Thee Journal, Vol. 87, September 1978, page 587 (John
Jurgens "Steadicam as a Design Problem", SMPTE jou
nal Vol.87, Sep, 1978, P587)) Problems to be Solved by the Invention However, the conventional configuration as described above has a problem in that its anti-vibration property is fixed. For example, when a photographer holds an image capturing device in his / her hand and takes an image while walking, the image capturing device shakes in a cycle in which the photographer visits, but it is desirable that the screen does not shake. On the other hand, when the photographer performs pan photographing, it is desirable that the photographing screen respond quickly in the direction intended by the photographer. If, in the above-mentioned conventional example, the image-stabilizing characteristic is selected so that the former photographing condition can suppress the screen shake, the photographing screen does not respond well as the photographer intends under the latter photographing condition. On the contrary, if the anti-vibration characteristic is selected according to the latter shooting condition, it is possible to quickly respond in the direction intended by the photographer, but under the former shooting condition, sufficient anti-vibration effect cannot be obtained. .

Further, according to the above-mentioned conventional example, it is necessary to provide the counterweight 1302, which makes it difficult to reduce the size and weight.

Means for Solving the Problems In order to solve the above-mentioned problems, a photographing apparatus according to the present invention is a lens barrel portion in which a plurality of lenses and an image pickup element are mounted, and an image signal from an electric signal obtained by the image pickup element. Image signal processing means for producing the above, a support member for rotatably supporting the lens barrel portion around a rotation axis orthogonal to or substantially orthogonal to the incident light ray axis to the lens barrel portion, the lens barrel portion and the support member. An actuator means mounted between the two to rotate and drive the lens barrel portion, a relative angle detecting means for detecting a relative angle between the lens barrel portion and the support, and an angular velocity with respect to the inertial coordinate of the lens barrel portion. Lens barrel angular velocity detection means, support angular velocity detection means for detecting angular velocity relative to the inertial coordinate of the support, and absolute value of output signal of the support angular velocity detection means exceeds a predetermined value and continues for a certain time or more. When moved If the output signal of the relative angle detection means is within a predetermined range and the absolute value of the output signal of the support body angle detection means is below a predetermined value and continues for a certain period of time or more, it is determined to be still shooting. Photographing mode determining means, combining means for generating and outputting a combined signal from the output signal of the lens barrel angular velocity detecting means and the output signal of the relative angle detecting means, and amplifying the combined signal to supply power to the actuator means. When the photographing mode discriminating means discriminates the still photographing, the control gain of the synthesizing means is adjusted to control the lens barrel portion to stand still in the inertial coordinate, and the photographing mode discriminating means. When it is determined that the moving image is taken, the control gain of the synthesizing means is adjusted to control the lens barrel and the support so as to match the angles with respect to the inertial coordinates. Than it is.

Operation According to the present invention, when the photographing mode discrimination means discriminates the still photographing by the above-mentioned constitution, the lens barrel part is controlled to be stationary or substantially stationary at the inertial coordinate, and the photographing mode discrimination means is operated. When it is determined that the shooting is a moving image, the respective angles of the lens barrel portion and the support body are smoothly matched in the inertial coordinates, and the lens barrel portion is controlled so as to follow the support body well. To do. Therefore, it is possible to obtain a stable image with little screen shake regardless of the shake of the photographer and the shooting device during still shooting, and it is possible to reduce size and weight without impairing operability during moving shooting such as pan shooting and tilt shooting. An imaging device 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 an image sensor 2 (for example, CCD
(A plate or an image pickup tube) is attached, and the reflected light from the subject is condensed to form an image on the image pickup element 2, and a charge signal (electrical signal)
Convert to. The image signal processing circuit 10 sequentially reads out the charge signals 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 rotatably driven about the rotation shaft 6 in the yaw direction. The rotation shaft 6 of the actuator 5 passes through the center of gravity G of the lens barrel portion 1 and is rotatably supported by the support body 3. Further, the support body 3 is provided with a grip portion 4 that 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 back yoke 201 made of a ferromagnetic material of the magnet 202 is attached to the lens barrel portion 1 and rotates together with the rotating shaft 6. The magnet 202 is magnetized to have four poles and generates a magnetic field flux. Bearing 20 of rotating shaft 6
In the coil yoke 203 to which 7 is attached, the coils 204a, 2
04b and Hall element (magnetism sensitive element) 9 are fixed. In this example, the magnet 202 is attached to the lens barrel portion 1, and the coil yoke 203 is attached to the support body 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 so as to substantially face the magnetic pole switching portion of the magnet 202.
(Angle θm of lens barrel 1) An output signal corresponding to a relative angular difference θmo (= θo−θm) of the coil yoke 203 (angle θo of the support 3) is generated. It should be noted that θm is the angle of the lens barrel portion 1 around the rotation axis 6 viewed from the inertial coordinate, and θo is the angle of the support 3 around the rotation axis 6 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 factor by the operation amplification circuit composed of the operational amplifier 301 and the resistors 302, 303, 304, 305 to obtain the output signal c. + VH, -VH are suitable power supplies, and resistors 306 and 30
An appropriate bias voltage is applied to the Hall element 9 via 7.

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 portion 1 in the inertial coordinates. 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 having a predetermined frequency (for example, 1 kHz), and forcibly vibrates the drive element 402 made of the piezoelectric element of the angular velocity sensor 7 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 with the drive element 402 at the same frequency. 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 1 in inertial coordinates and the angular velocity due to forced vibration. The sense element 403 causes a mechanical strain due to the Coriolis force and generates an electric signal due to a piezoelectric action. The output of the sense element 403 is periodically detected by the synchronous detection circuit 404 at the same frequency as the forced vibration, and the low-frequency component (for example, about DC to 100 Hz) of the detected output is extracted by the low-pass filter 405. A signal d proportional to the angular velocity ωm about the rotation axis 6 of is obtained.

The output signal c of the relative angle detection circuit 11 and the output signal d of the lens barrel angular velocity detection circuit 12 are input to the support angular velocity detection means 17. The support angular velocity detection means 17 outputs a signal u proportional to the angular velocity in the inertial coordinates of the support 3 operated by the photographer from these input signals. The output signal u of the support angular velocity detection circuit 17 is input to the photographing mode determination means 13. The photographing mode discrimination means 13 discriminates whether the photographer is performing still photography or pan photography from these input signals. Here, the still shooting means that the photographer operates the photographing device without changing the photographing direction,
The pan photographing means that the photographer operates the photographing apparatus so as to rotate the photographing direction in the yaw direction.

The discrimination result of the photographing mode discrimination means 13 is input to the synthesizing means 14. Further, the output signal c of the relative angle detection circuit 11 and the output signal d of the lens barrel angular velocity detection circuit 12 are input to the synthesizing means 14. When the shooting mode determination means 13 determines that the shooting mode is determined to be still shooting, the control calculation means 14 determines the relative angle detection circuit 11
Output signal c and the output signal d of the lens barrel angular velocity detection circuit 12
And the result of integration calculation of the output signal c of the relative angle detection circuit 11 are respectively added with a first predetermined gain, and when the photographing mode discrimination means 13 discriminates the pan photographing, the relative angle detection circuit 11 Output signal c, the output signal d of the angular velocity detection circuit, the result of the integral calculation of the output signal c of the relative angle detection circuit 11, and the angular velocity command obtained from the output signal c of the relative angle detection circuit 11, respectively. Addition is performed with a predetermined gain, and the calculation result is output as an output signal e.

FIG. 5 shows the configuration of the photographing mode discrimination means 13 and the composition means 14. In this embodiment, the photographing mode discrimination means 13 and the control calculation means 14 are composed of A / D converters 502 and 503, a calculation device 501, a memory 504 and a D / D converter.
It is composed of an 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 produces a digital signal q corresponding to the value of the output signal d of the angular velocity detection circuit 12. 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 outputs the digital signal p of the A / D converter 502 and the digital signal of the A / D converter 503. RAM for signal q
The area (random access memory area) is fetched, subjected to a predetermined calculation, and then combined to generate the combined digital signal w by D /
It outputs to the A converter 505, and the synthetic signal e is obtained.

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 input the clock pulse 1 to the down pulse input terminal D or the up pulse input terminal U of the counter circuit 606 according to the comparator signal n (when the signal h is "H"). Time). The counter circuit 606 is
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 606
The digital signal p 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 arithmetic unit 501 sets the signal k to "L" for a predetermined short time to read a stable digital signal q.

The output signal e of the synthesizing means 14 is input to the drive circuit 16, and a voltage signal (or current signal) f proportional to the signal e is supplied to the coils 204a and 204b of the actuator 5. FIG. 7 shows a specific configuration of the drive circuit 16. The operational amplifier 701, the transistors 704 and 705, and the resistors 702 and 703 form a power amplification circuit, which outputs a voltage signal f obtained by amplifying the signal e by a predetermined number.

Now, the built-in program of the arithmetic unit 591 will be described.
First, an outline will be described based on the basic flowchart shown in FIG.

The process 801 has an interrupt from the timer.
The timer generates an interrupt signal at every predetermined time ΔT, and shifts to when an interrupt occurs. That is, the following processing is performed at the sampling time ΔT.

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,
Store in memory 504. Further, the digital signal q corresponding to the angular velocity ωm viewed from the inertial coordinate of the lens barrel portion 1 is fetched from the A / D converter 503 and stored in the memory 504.

In process 803, the digital signal p corresponding to the relative angle θmo between the lens barrel portion 1 and the support body 3 and the digital signal q corresponding to the angular velocity ωm of the lens barrel portion 1 from the inertial coordinate are used to determine the support seen from the inertial coordinate. The angular velocity ωo of the body 3 is calculated, and it is determined from the value of the angular velocity ωo of the support body 3 whether the photographing is still photography or pan photography. And if it is judged that it is still shooting, it moves to
If it is determined to be pan photography, the process moves to.

In process 804, a control calculation is performed so that the lens barrel unit 1 is stationary or substantially stationary in the inertial coordinates, and a signal e to be a command input of the drive circuit 16 is generated. After this processing, shifts to.

In process 805, control calculation is performed so that the lens barrel portion 1 smoothly follows the support body 3, and a signal e which is a command input of the drive circuit 16 is generated. After this processing, shifts to.

Incidentally, the processing 803 is the photographing mode discrimination means 13 in FIG.
The process 804 and the process 805 correspond to the control calculation means 14 in FIG.

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 that holds 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. Then 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 portion 1 is newly fetched and stored in the variable Wn, and then the signal k is set to "H" again. That is, at this time, the information of the relative angle θmo between the present barrel portion 1 and the support 3 is stored in the variable Qn, and the barrel portion 1
The information of the angular velocity ωm of is stored in the variable Wn.
Furthermore, the information of each one sampling before is the variable Qn-
1 and the variable Wn-1.

FIG. 9B is a detailed flowchart of the process 803. First, in process 901, relative to the lens barrel 1 and the support 3 one sampling before, from the variable Qn holding a value corresponding to the current relative angle θmo (= θo−θm) between the lens barrel 1 and the support 3. Subtract the variable Qn-1 that holds the value corresponding to the angle θmo,
The result is stored in the variable ΔQ. Next, in process 902, a value ΔQ / ΔT obtained by dividing the variable ΔQ by the sampling period ΔT is added to the variable Wn representing the angular velocity ωm of the lens barrel 1 with respect to the inertial coordinate. That is, the following calculation (1) is performed, and the calculation result is stored in the variable Wo.

Wo = Wn + ΔQ / ΔT (1) In the formula (1), the term [ΔQ / ΔT] is the lens barrel 1 and the support 3
Therefore, if the sampling period Δ is sufficiently small, the second item of the equation (1) is the relative angular velocity (ωo−ωm) of the support 3 with respect to the lens barrel portion 1.
[Wn + ΔQ / ΔT], which corresponds to the sum of this term and the angular velocity ωm of the lens barrel 1, indicates a value corresponding to the angular velocity ωo of the support 3. Therefore, the variable Wo in equation (1)
Represents the angular velocity ωo with respect to the inertial coordinate of the support 3. In the process 903, the variable PFL indicates that the pan photographing is determined when the content is “1”, and the still photographing is determined when the content is “0”.

Now, if PFL = 1 in the result of the processing 803 at the previous sampling, the result of the processing 903 is
Move to 904. In process 904, it is determined whether or not the absolute value of the variable Qn exceeds the predetermined value QAIS. If the absolute value of the variable Qn does not exceed the predetermined value QAIS, the process proceeds to processing 905, and if it exceeds, the process proceeds to processing 909. Variable in process 905
If the absolute value of Wo does not exceed the predetermined value WAIS, process 906
To 909, and if it exceeds, to 909. In process 906, the content of the variable NAIS is incremented by "1". In process 907, the variable N
It is determined whether AIS exceeds a predetermined value TAIS / ΔT.
If the variable NAIS exceeds the predetermined value TAIS / ΔT, process 908.
To 910, and if not exceeded, to 910. Processing 9
In 08, the variable PFL is set to "0". In process 909, the variable NAIS is set to "0". The variable NAIS acts as a kind of counter, and the series of processing shown in FIG.
Processing is performed since timer interrupts occur every T.
The process 907 corresponds to measuring the time ΔT × NAIS.

That is, when it is determined that the pan shooting is performed (PFL =
1), the absolute value of the relative angle θmo between the lens barrel 1 and the support 3 is less than or equal to a predetermined value (corresponding to QAIS), and the support 3
The state in which the absolute value of the angular velocity ωo of is less than or equal to a predetermined value (corresponding to WAIS) is determined to be still shooting only after a predetermined determination time (corresponding to TAIS) (PFL = 0). While performing pan photography, the above conditions are not satisfied and PFL = 1.

On the contrary, if PFL = 0 in the result of the previous processing 803, the processing proceeds to processing 911 as a result of processing 903. Processing 911
Then, it is determined whether or not the absolute value of the variable Wo exceeds a predetermined value WPAN. If the absolute value of the variable Wo exceeds the predetermined value WPAN, the process proceeds to step 912, and if not, the process proceeds to step 915. In process 912, the content of the variable NPAN is incremented by "1". In process 913, it is determined whether the variable NPAN exceeds a predetermined value TPAN / ΔT. If the variable NPAN exceeds the predetermined value TPAN / ΔT, the process proceeds to processing 914, and if not, processing 910.
Move to. In process 914, the variable PFL is set to "1". Processing 91
In 5, the variable NPAN is set to "0". The variable NPAN functions as a kind of counter, and the series of processes shown in FIG. 8 is performed by the timer interrupt generated at each time ΔT, so that the processes 912 to 913 measure the time ΔT × NPAN. Is equivalent to In process 914, the variable PFL is set to "1". In process 915, the variable NPAN is set to "0".

That is, when it is determined that the still image is taken (PFL =
0), the absolute value of the angular velocity Wo of the support 3 is a predetermined value (W
It is determined that the pan shooting is performed (PFL = 1) for the first time after the state of being equal to or more than PAN) continues for a predetermined determination time (corresponding to TPAN) or more.

Then, in process 910, the process proceeds to the next process based on the determination result of still image capturing or pan image capturing. That is, if it is determined in the processing up to the previous stage that still image capturing is performed, the process proceeds to step 804, and if it is determined that pan image capturing is performed, the process proceeds to step 805.

FIG. 9C is a detailed flowchart of the process 804. First, the variable En that holds the value of the digital signal W corresponding to the signal e that is the command input of the drive circuit 16 one sampling before is stored in the variable En-1. Next, a variable that holds a value corresponding to the current relative angle θmo between the lens barrel 1 and the support 3.
A variable Qn-1 holding a value corresponding to the relative angle θmo of the lens barrel 1 and the support 3 before one sampling is subtracted from Qn, and the result is stored in a variable ΔQ. Next, a variable Wn-1 which holds a value corresponding to the angular velocity ωm of the lens barrel portion 1 before one sampling is subtracted from a variable Wn which holds a value corresponding to the current angular velocity ωm of the lens barrel portion 1 The result is stored in the variable ΔW. Then, the following calculation (2) is performed using K1, K2, Ta, and ΔT as constants, and the calculation result is stored in the variable ΔE.

ΔE = -K1 × ΔW + K2 × (ΔQ + ΔT × Qn / Ta)
(2) Next, the variable ΔE and the variable En-1 are added, and the result is newly stored in the variable En. Finally, the content of the variable En is output as a signal W to the D / A converter 505 (see FIG. 5). After that, the process shifts to and the next timer interrupt occurs (see FIG. 8).

FIG. 9D is a detailed flowchart of the process 805. First, the variable En holding the value of the digital signal w corresponding to the signal e which is the command input of the drive circuit 16 one sampling before is stored in the variable En-1. Next, a variable that holds a value corresponding to the current relative angle θmo between the lens barrel 1 and the support 3.
A variable Qn-1 holding a value corresponding to the relative angle θmo of the lens barrel 1 and the support 3 before one sampling is subtracted from Qn, and the result is stored in a variable ΔQ. Next, a variable Wn-1 holding a value corresponding to the angular velocity ωm of the lens barrel portion 1 before one sampling is subtracted from a variable Wn holding a value corresponding to the current angular velocity ωm of the lens barrel portion 1, The result is stored in the variable ΔW. Then, the following calculation (3) is performed using K3, K4, Tw, Tp, and ΔT as constants, and the calculation result is stored in the variable ΔE.

ΔE = −K3 × (ΔW−ΔQ / Tw) + K4 × (ΔQ + ΔT × Qn / Tp) (3) Next, the variable ΔE and the variable En-1 are added, and the result is newly stored in the variable En. . Finally, the content of the variable En is output as a signal w to the D / A converter 505 (see FIG. 5). After that, the process shifts to and the next timer interrupt occurs (see FIG. 8).

Hereinafter, the control operation and the image stabilization effect at the time of still image capturing 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 this 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 are omitted because they can be sufficiently ignored in the frequency region described below. Now, the relative angle θmo between the angle θm of the lens barrel portion 1 and the angle θo of the support body 3 when viewed from the inertial coordinates is easily detected by the Hall element 9 that detects the magnetic field of the magnet 202 of the actuator 5. The Hall element 9 and the relative angle detection circuit 11 are represented by a block 1001 and obtain a signal c (output signal of the position detection circuit 11) that is KQ · AQ times θmo. KQ is the magnetic flux density / voltage conversion gain of the Hall element 5, and AQ is the voltage gain of the relative angle detection circuit 11. On the other hand, the angular velocity ωm of the lens barrel 1 viewed from the inertial coordinate is determined by the angular velocity sensor 7 and the angular velocity detection circuit.
Detected by 12 and detected by block 1008,
Obtain the signal d represented by block 1008 which is KW · AW times ωm. KW is the angular velocity / voltage conversion gain of the angular velocity sensor 7, and AW 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 of the computing unit 501 (the portion surrounded by the broken line corresponds to that),
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 to obtain a combined signal e. In the block 1004 corresponding to the drive circuit 16, the signal e is Ae
It is amplified twice to obtain the voltage signal f. In the block 1005 corresponding to the actuator 5, the voltage signal f is the torque Tm.
Is converted to. Here, R is a combined resistance value of the coils 204a and 204b, and Kt is a torque constant. Block 1006 represents transmission from torque Tm to angular velocity ωm due to mechanical moment of inertia Jm of lens barrel 1, and block 1007 represents ωm and θ.
represents the relationship of m. Therefore, from this block diagram,
The transfer characteristic from ω to θm is as shown in Fig. 11 when it is expressed by a Bode diagram approximated by a broken line. In FIG. 11, 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).

It is known that the fluctuation of the photographing device in the still image is mainly distributed in the range of 0.5 Hz to 5 Hz. Therefore, if the vibration-proof characteristics of the present photographing device are set as shown in FIG. 11, the rotation angle θm of the lens barrel portion 1 hardly changes regardless of the fluctuation of the rotation angle θo of the support body 3, and the fluctuation of the photographing screen. It can be seen that 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 of the next stage (En = En-1 + ΔE).

That is, the first term [−K1 × ΔW] in the equation (2) is a component provided to set each speed ωm of the lens barrel portion 1 to “0” and to make the lens barrel portion 1 stand still 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 smaller than. This is because it is important to set the angular velocity ωm of the lens barrel portion 1 to “0”. That is, when K2 is increased, the support 3 having the angle θm of the lens barrel 1 is
The followability with respect to the angle θo is improved, and the anti-vibration 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 exceed the loss, and the relative angle θmo between the lens barrel 1 and the support body 3 does not reach "0". That is, the angle θm of the lens barrel portion 1 and the angle θo of the support 3 have a steady deviation ω.
Control of m = 0 will be performed. Therefore, the term [K2 × ΔT × Qn / Ta] of the second term of the equation (2) is provided, and it has the meaning of integral calculation of θmo together with the processing of the next stage (En = En−1 + ΔE). The angle θm of 1 and the angle θ of the support 3
Eliminate stationary deviations of o. That is, if there is a steady deviation between θo 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 × ΔQ]
[T × Qn / Ta] is added to En for each sampling, so that the torque generated by the actuator 5 increases with time, overcoming the bearing loss, and eliminating the steady deviation between θo and θm.

Now, the control operation at the time of pan photographing will be described. First, when performing still photography, as described above, the lens barrel unit 1
Is controlled so as to stand still in the inertial coordinate system. Therefore, if the photographer operates the support body 3 from this state (still photography) to start pan photography, the lens barrel portion 1 does not follow the support body 3. It is controlled so as to be stationary (actually, the term [K2 × ΔQ] and the term [K2 × ΔT × Qn / T in the above mixing operation (2)].
(It works a little due to the action a)) The relative angle θmo between the lens barrel 1 and the support 3 gradually increases. However,
The absolute value of the angular velocity ωo of the support 3 is set to a predetermined value (QPAN in FIG. 9A) by the photographing mode determination means 13 (process 803).
(Corresponding to the above), it is determined that the pan photographing is performed, and the control calculation is performed by the process 805. Process 805
Then, the control calculation is performed so that the angle θm of the lens barrel portion 1 smoothly agrees with the angle θo of the support body 3 and follows well. This will be described in detail below.

Each term in the mixed operation (3) is processed in the next process (En
= En-1 + ΔE) has the following meaning.

That is, the first term of expression (3) [-K3 x (ΔW-ΔQ / Tw)]
Serves to match the angular velocity ωm of the lens barrel portion 1 with the angular velocity ωo of the support 3 with a time constant Tw. This is because in the steady state (when the pan photographing is determined and the processing 805 is always performed), this term is “0”, and therefore the following expression (4) is obtained.

ΔW = ΔQ / Tw (4) From the above description, the equation (4) can be rewritten as the following equation (5).

Wn-Wn-1 = (Qn-Qn-1) / Tw (5) Further, the equation (4) can be rewritten as the following equation (6).

(Wn-Wn-1) / [Delta] T = [Wn + (Qn-Qn-1) / [Delta] T-Wn] / Tw (6) Equation (6) is obviously a difference equation and the limit [Delta] T of the sampling period [Delta] T → When 0 is taken, the equation (6) becomes a differential equation of the following equation (7) where t is time.

dWn / dt = (Wn + dQn / dt−Wn) / Tw (7) where Wn corresponds to the angular velocity ωm of the lens barrel 1, and Qn corresponds to the relative angle θmo of the support 3 to the lens barrel 1. Therefore, the equation (7) can be rewritten as the following equation (8).

dωm / dt = (ωm + dθmo / dt−ωm) / Tw (8) Now, in the equation (8), the term [dθmo / dt] represents the relative angular velocity between the lens barrel portion 1 and the support body 3. [Ωm + d], which is the sum of this term and the angular velocity ωn of the lens barrel 1.
θmo / dt] represents the angular velocity ωo of the support 3. Therefore, the equation (8) becomes the following equation (9).

dωm / dt = (ωo−ωm) / Tw (9) When the differential equation (9) is solved for ωm, the equation (10) is eventually obtained.
To get

ωm = ωo × (1-e ^{−t / TW} ) (10) That is, in the equation (10), the angular velocity ωm of the lens barrel 1 is the time constant Tw.
Indicates that it matches the angular velocity ωo of the support 3.
That is, ΔQ / Tw in the equation (3) gives an angular velocity command to the lens barrel 1. However, the term [−K3 × (ΔW−ΔQ / T
w)] alone, the angle θm of the lens barrel 1 and the angle θ of the support 3
O does not match, and is in the form of being shifted by a difference at the time when the shooting mode determination means 13 determines the pan shooting. Therefore, the term [K4 × ΔQ] is the relative angle θ between the lens barrel 1 and the support 3.
It is provided so that mo is “0” and the angle θm in the inertial coordinate of the lens barrel portion 1 and the angle θo in the inertial coordinate of the support body 3 are substantially matched. However, if the gain K4 is increased, the angle difference between the angle θm of the lens barrel portion 1 and the angle θo of the support body 3 at the time when the pan photographing is detected is controlled so that the angle sharply becomes “0”. It seems strange to me that the shooting screen suddenly flows. On the contrary, when the gain K4 is reduced, the torque Tm generated by the actuator 5 due to the term [K4 × ΔQ] is generated.
Is small, the angle θm of the lens barrel portion 1 and the angle θo of the support body 3 do not match when the bearing loss of the actuator 5 exists. Therefore, the term [K4 × ΔT × Qn / Tp] is provided. This item [K4 × ΔT × Qn / Tp] is the next processing (En
= En-1 + ΔE) means an integral calculation of the relative angle θmo between the lens barrel 1 and the support 3, and compensates for a steady deviation between the angle θm of the lens barrel 1 and the angle θo of the support 3. . That is, if there is a steady deviation between θo and θm, the term [K4 × ΔT × Qn / Tp] 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 [K4 × ΔQ] is smaller than the bearing loss, the term [K4 × ΔT × Qn / Tp] is added to En for each sampler, The torque generated by the actuator 5 increases with time and exceeds the bearing loss, and the steady deviation between θo and θm is eliminated.

By the way, when the photographer operates the photographing apparatus of the present embodiment in a state of still photography, pan photography, and still photography again, the angle θo in the inertial coordinate of the support body 3 and the angle θm in the inertial coordinate of the lens barrel portion 1 The movement will be described with reference to FIG. FIG. 12 shows the angle θo in the inertial coordinates of the support body 3 and the angle in the inertial coordinates of the lens barrel portion 1 when the photographer operates the photographing apparatus of the present embodiment such as still photographing, pan photographing, and still photographing. It shows the movement of θm. The curve 1201 is the angle θo in the inertial coordinate of the support 3.
The photographer performs still photography until time t1, and pan photography starts from this time (t1) at time t3.
Indicates that the camera is in still photography again. A curve 1202 shows the movement of the lens barrel 1 at the angle θm in the inertial coordinates. When the pan photographing is started at time t1, the photographing mode discriminating means 13 (process 803) still discriminates the still photographing at this time, so that the lens barrel portion 1 moves slightly as described above. The followability with respect to 3 is poor, and the relative angle θmo between the lens barrel 1 and the support pair 3 expands. Eventually,
After a time corresponding to TPAN defined in process 803, when the relative angle θmo between the lens barrel portion 1 and the support 3 increases to a value corresponding to θPAN defined in process 803 at time t2, it is determined to be pan photography by the process 803. The control calculation is entrusted to the process 805. Then, as described above, the angle θm of the lens barrel portion 1 is smoothly matched with the angle θo of the support body 3 and is controlled so as to follow well. Then, at time t3, when the photographer enters still shooting, after a time corresponding to TAIS defined in the process 803, the process 803 again determines still shooting at time t4. In the above operation, the angle θm of the lens barrel portion 1 slightly exceeds the angle θo of the support body 3 (overshoot). This is the integral term [K4 × Δ of the mixed operation (3) in the process 805.
T × Qn / Tp], but the degree of the overshoot is slight and the photographer does not feel uncomfortable.

As described above, the photographic device having the image stabilizing mechanism is constructed, the operability of the photographic device of the present invention is actually examined, and the values of the constants of Tp, Ta, WPAN, WAIS, TPAN, and TAIS described above are calculated. When decided, Tp = 0.3 seconds, Ta = 3.5 seconds, WPAN = 3
Degrees / second, WAIS = 3 degrees / second, TPAN = 0.3 seconds, and TAIS = 1 second, the photographer can take normal shooting and perform smooth operations for still and moving shooting without feeling discomfort. Could be realized.

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, in the above description, the angular velocity of the support is calculated by the support angular velocity detecting means from the relative angular difference between the support and the lens barrel and the angular velocity of the lens barrel, but an angular velocity sensor is newly attached to the support. Needless to say, it may be directly detected. 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. Further, since the relative position is detected by the Hall element (magnetism sensitive element) that detects the magnetic field of the magnet of the actuator, the configuration is simple and the number of parts is small. It has a discriminating means to achieve both the anti-vibration effect required for still photography and the good followability required for pan photography. Therefore, according to the present invention, for example, if a video camera is configured, a compact, lightweight and high-performance video camera with a vibration isolation mechanism can be easily obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a photographing device according to an embodiment of the present invention,
2 is a configuration diagram showing a specific configuration of the actuator of FIG. 1, FIG. 3 is a circuit diagram showing a specific configuration of the relative angle detection circuit of FIG. 1, and FIG. 4 is a mirror of FIG. FIG. 5 is a configuration diagram showing a specific configuration of the tubular angular velocity detection circuit, FIG. 5 is a configuration diagram showing a specific configuration of the photographing mode discrimination means and the composition means of FIG. 1, and FIG. 6 is A / of FIG. FIG. 7 is a configuration diagram showing a specific configuration of the D converter, FIG. 7 is a circuit diagram showing a specific configuration of the drive circuit of FIG. 1, and FIG. 8 is stored in the ROM area of the memory of FIG. A basic flow chart of the built-in program, FIG. 9 is a detailed flow chart of each processing of FIG. 8, FIG. 10 is a block diagram for explaining the operation of FIG. 1, and FIG.
FIG. 12 is a Bode diagram for explaining the operation of the figure, FIG. 12 is an operation explanatory view for explaining the operation of FIG. 1, and FIG. 13 is a configuration diagram of a conventional photographing apparatus. 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 ... Shooting mode discrimination Means, 14 ... Control computing means, G ... Center of gravity of lens barrel 1,
16 ... Drive circuit, 501 ... Calculator, 502,503 ... A / D converter, 504 ... Memory, 505 ... D / A converter.

Claims (5)

[Claims] 1. A lens barrel portion on which a plurality of lenses and an image pickup device are mounted, image signal processing means for generating an image signal from an electric signal obtained by the image pickup device, and an axis of a light ray incident on the lens barrel portion. Alternatively, a support body that rotatably supports the lens barrel portion around substantially orthogonal rotation axes, and an actuator means that is mounted between the lens barrel portion and the support body and that drives the lens barrel portion to rotate, Relative angle detecting means for detecting a relative angle between the lens barrel and the support, lens barrel angular velocity detecting means for detecting an angular velocity of the lens barrel with respect to the inertial coordinates, and angular velocity with respect to the inertial coordinates of the support. When the absolute values of the output signals of the support angular velocity detection means and the support angular velocity detection means exceed a predetermined value and continue for a certain time or more, it is determined that the moving image capturing is performed, and the output signal of the relative angle detection means is set to a predetermined value. within, When the absolute value of the output signal of the support angular velocity detection means is equal to or less than a predetermined value and continues for a certain period of time or more, a shooting mode determination means for determining still photography, and an output signal of the lens barrel angular velocity detection means and the relative Combining means for generating and outputting a combined signal from the output signal of the angle detecting means,
The driving means is configured to amplify the combined signal and supply electric power to the actuator means. When the photographing mode judging means judges that the photographing is still photography, the control gain of the combining means is adjusted to make the lens barrel part in inertial coordinates. When the photographing mode discriminating means discriminates the moving photographing, the control gain of the synthesizing means is adjusted so that the angles of the lens barrel portion and the support body with respect to the inertial coordinates are matched. Imaging device characterized by. 2. The support angular velocity detecting means is configured to add the differential value of the output signal of the lens barrel angular velocity detecting means and the differential value of the output signal of the relative angle detecting means. The image capturing apparatus according to item (1). 3. 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. 4. The photographing apparatus according to claim 1, wherein an angular velocity sensor using a vibration type gyro is used as the angular velocity detecting means. 5. The transfer characteristic of the lens barrel rotation angle with respect to the support rotation angle in the inertial coordinate 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 ( The image pickup apparatus according to claim (1), characterized in that it is attenuated at −6 dB / oct in a frequency range of f1 <f2) or less and is attenuated at −12 dB / oct in a frequency range of f2 or more.