JPH0720212B2 - 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 capable of obtaining a stable image even when disturbance vibration is applied to the image pickup apparatus body.

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 continuous rod 1303. Reference numeral 1305 is a joint that rotatably connects the continuous rod 1303 and the support rod 1304. Shooting is supported by supporting rod 1304,
The operation of this photographing device is performed. 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 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 portion 1301 leans against a constant angle. 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" SMP
Thee Journal Vol. 87 Sep. 1978 Page 578 (J
ohn Jurgens "Steadicam as a Design Problem", SMPTE
jounal 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 the image stabilization characteristic is selected so as to suppress the screen shake under the former photographing condition in the above conventional example, the photographing screen does not respond well as the photographer intends under the latter photographing condition. On the other hand, if the image stabilization characteristics are selected according to the latter shooting conditions, a quick response can be achieved in the direction intended by the photographer, but under the former shooting conditions, a sufficient image stabilization effect can be obtained. Can not.

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 of the present invention provides a lens barrel unit having a plurality of lenses and an image pickup device, and an image signal from an electric signal obtained by the image pickup device. 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 incident ray axis to the lens barrel portion, and the lens barrel portion and the support body. An actuator that is mounted between the actuators and drives the lens barrel portion to rotate, a relative angle detection unit that detects a relative angle between the lens barrel portion and the support, and an angular velocity of the lens barrel portion around the rotation axis. The angular velocity detecting means, the drive circuit for supplying electric power to the actuator in proportion to the command input, and the pan photographing or the tilt photographing by seeing that the absolute value of the output of the relative angle detecting means exceeds the first predetermined value. Moving shots such as It is determined that it is a shadow, and the absolute value of the output of the relative angle detecting means is smaller than the second predetermined value, and the absolute value of the output of the angular velocity detecting means is smaller than the third predetermined value for a predetermined time. When the above continues, the shooting mode determination means for determining still shooting, and when the shooting mode determination means determines for still shooting, the output of the relative angle detection means and the output of the relative angle detection means are integrated. The calculation result and the output of the angular velocity detecting means are added with a first predetermined gain, and the addition result is used as a command input of the drive circuit, and the shooting mode determination means determines that the shooting mode is moving shooting. In this case, the output of the relative angle detecting means, the result obtained by dividing the output of the relative angle detecting means by a predetermined time constant, and the result of integrating the output of the relative angle detecting means, The above By adding a predetermined gain output and a second respective speed detection means is to and a command input and makes control operation unit of the driving circuit the addition result.

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. Therefore, it is possible to obtain a stable image with little screen shake regardless of the shaking of the photographer and the shooting device during still shooting, and it is possible to reduce the size and weight without impairing operability during moving shooting such as pan shooting and tilt shooting. 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 to collect reflected light from a subject and form an image on the image pickup element 2 to generate 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 to rotate and drive the lens barrel portion 1 in the yaw direction around a rotation shaft 6 (in the use state, the lens barrel portion 1 is substantially horizontal). It can be freely rotated on. 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 coil 204a,
204b and the 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 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, and θo is the angle of the support 3 around the rotation axis 6.

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 a differential amplifier circuit including an operational amplifier 301 and resistors 302, 303, 304, 305, and an output signal c
Is getting + VH and -VH are suitable power supplies and resistors
An appropriate bias voltage is applied to the Hall element 9 via 306 and 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 an output signal b in response to the rotation angular velocity of the lens barrel 1 around the rotation axis 6. The output signal b of the angular velocity sensor 7 is input to the angular velocity detection circuit 12, and the signal d proportional to the angular velocity ωm around the rotation shaft 6 of the lens barrel portion 1 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 oscillation 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 portion 1 rotates around the rotating shaft 6, a mechanical Coriolis force is generated. Since the Coriolis force is proportional to the product of the angular velocities of the two axes of the sense element 403 orthogonal to each other, it is proportional to the product of the angular velocity ωm of the lens barrel 1 around the rotation axis 6 and the angular velocity due to the 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 synchronously detected by the synchronous detection circuit 404 at the same frequency as the forced vibration, and the low-pass filter 405 detects the low-frequency component (for example, DC to 100) of the detected output.
By taking out (about Hz), a signal d proportional to the angular velocity ωm of the lens barrel 1 around the rotation axis 6 can be obtained.

The output signal c of the relative angle detection circuit 11 and the output signal d of the angular velocity detection circuit 12 are input to the photographing mode determination means 13. The photographing mode discrimination means discriminates from the input signals whether the photographer is performing still photography or pan photography.

Here, the still shooting means that the photographer operates the photographing device without changing the photographing direction, and the pan photographing means that the photographer rotates the photographing direction in the yaw direction. It means operating the imaging device.

The determination result of the photographing mode determination means 13 is input to the control calculation means 14. Further, the output signal c of the relative angle detection circuit 11 and the output signal d of the angular velocity detection circuit 12 are input to the control calculation means 14. The control calculation means 14 is a photographing mode determination means 13
If it is determined that the still image is taken, the relative angle detection circuit
The output signal c of 11 and the output signal d of the angular velocity detection circuit 12,
The output of the relative angle detection circuit 11 is added when the result of integration calculation of the output signal c of the relative angle detection circuit 11 is added with a first predetermined gain, and the shooting mode determination means 13 determines that pan shooting is performed. The signal c and the result obtained by dividing the output signal c of the relative angle detection circuit 11 by a predetermined time constant, the result of the integral calculation of the output signal c of the relative angle detection circuit 11, and the output signal of the angular velocity detection circuit 12. d is added with a second predetermined gain, and the calculation result is output as an output signal e.

FIG. 5 shows the structures of the photographing mode discrimination means 13 and the control calculation means 14. In this embodiment, the photographing mode discrimination means 13 and the control calculation means 14 are composed of A / D converters 502, 503, a calculation device 501 and a memory 50.
4 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 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. Signal q
Capture in RAM area (random access memory area),
A predetermined operation is performed and then combined, and the combined digital signal w is output to the D / A converter 505 to obtain a combined signal e.

FIG. 6 shows a specific configuration of the A / D converter 502 (the same applies to the A / D converter 503). Input signal c and D / A converter
The output signal m of 607 is compared by the comparator 601,
A comparison 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
The 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"). . The counter circuit 606 subtracts one from the internal state by the input pulse to the down pulse input terminal D, and adds one by one to the internal state 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 control calculation means 14 is input to the drive circuit 16 and is 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. Operational amplifier
A power amplifier circuit is configured by 701, transistors 704 and 705, and resistors 702 and 703, and a voltage signal f obtained by amplifying the signal e by a predetermined number is output.

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 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. Furthermore, the angular velocity ωm of the lens barrel 1
The digital signal q corresponding to is fetched from the A / D converter 503 and stored in the memory 504.

In process 803, whether the still image capturing or the pan image capturing is performed is determined based on the digital signal p corresponding to the relative angle θmo between the lens barrel 1 and the support 3 and the digital signal q corresponding to the angular velocity ωm of the lens barrel 1. Determine. Then, if it is determined to be still image capturing, the process proceeds, and if it is determined to be pan imaging, the process proceeds.

In process 804, a control calculation is performed so that the lens barrel unit 1 is stationary or substantially stationary, 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.

The process 803 corresponds to the photographing mode discrimination means in FIG. 1, and the processes 804 and 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 changed to "L" by the relative angle θmo between the lens barrel portion 1 and the support body 3.
After the digital signal p corresponding to is newly captured and stored in the variable Qn, 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 taken in and stored in the variable Wn, and then the signal k is set to “H” again. That is, at this point in time, the lens barrel portion 1 and the support body 3 are present.
That is, the information of the relative angle θmo of the above is stored in the variable Qn, and the information of the angular velocity ωm of the lens barrel portion 1 is stored in the variable Wn. Furthermore, the information of each one sampling before is the variable Qn-1.
And stored in the variable Wn-1.

The ninth (b) is a detailed flowchart of the process 803. The variable PFL indicates that pan photography is determined when the content is “1”, and still photography is determined when the content is “0”.

Now, if PFL = 1 in the result of the main processing 803 at the previous sampling, the result of the processing 901, the processing 902
Move to. In process 902, it is determined whether the absolute value of the variable Qn exceeds a predetermined value QAIS. If the absolute value of the variable Qn does not exceed the predetermined value QAIS, the process proceeds to processing 903,
If it exceeds, the process proceeds to processing 907. In process 903, it is determined whether or not the absolute value of the variable Wn exceeds a predetermined value WAIS.
If the absolute value of the variable Wn does not exceed the predetermined value WAIS, the process proceeds to processing 904, and if it exceeds, the process proceeds to processing 907. processing
At 904, the content of the variable NAIS is incremented by "1". In process 905, it is determined whether the variable NAIS exceeds a predetermined value TAIS.
If the variable NAIS exceeds the predetermined value TAIS, the process proceeds to step 906, and if not, the process proceeds to step 908. In process 906, the variable PFL is set to "0". In process 907, the variable NAIS is set to "0". The variable NAIS acts as a kind of counter,
Since the series of processes shown in FIG. 8 is performed by the timer interrupt generated at each time ΔT, the processes 904 to 905 are performed.
Corresponds to measuring time ΔT × TAIS.

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 portion 1 and the support 3 is equal to or less than a predetermined value (corresponding to QAIS), and the absolute value of the angular velocity ωm of the lens barrel portion is equal to a predetermined value (WAIS). It is determined that still shooting is not performed (PFL = 0) for the predetermined time (corresponding to TAIS) for more than a predetermined time (corresponding to), and the above conditions are satisfied while pan shooting is performed. Without PFL = 1.

Contrary to the above, if PFL = 0 in the result of the previous processing 803, the processing proceeds to processing 909 as a result of processing 901.
In process 909, it is determined whether the absolute value of the variable Qn exceeds the predetermined value QPAN. If the absolute value of the variable Qn exceeds the predetermined value QPAN, the process proceeds to step 910, and if not, the step 908.
Move to. In process 910, the variable PFL is set to "1". Processing 91
At 1, the variable NAIS is set to "0".

That is, when it is determined that the still image is taken (PFL =
When the absolute value of the relative angle θmo between the lens barrel 1 and the support 3 is equal to or greater than a predetermined value (corresponding to PPAN), it is determined to be pan photographing (PFL = 1). This is because the lens barrel portion 1 is controlled so as to be stationary or substantially stationary during the still image capturing, and thus the relative angle between the lens barrel portion 1 and the support 3 in the process of shifting from this state (still image capturing) to the pan image capturing. The fact that θmo becomes large (details will be described later) is used.

Then, in process 908, the process shifts 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 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, the value corresponding to the relative angle θmo of the lens barrel 1 and the support 3 before one sampling is held from the variable Qn that holds the value corresponding to the current relative angle θmo between the lens barrel 1 and the support 3. Subtract the variable Qn-1,
The result is stored in the variable ΔQ. Next, the variable Wn-1 that holds the value corresponding to the angular velocity ωm of the lens barrel 1 before sampling is subtracted from the variable Wn that holds the value corresponding to the current angular velocity ωm of the lens barrel 1 Is stored in the variable ΔW. Then, the following calculation (1) 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) (1) Here, the priority of each operation in the above mixed operation is
() [Brackets], x [multiplication], / [division], + [addition],-[subtraction].

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, the value corresponding to the relative angle θmo of the lens barrel 1 and the support 3 before one sampling is held from the variable Qn that holds the value corresponding to the current relative angle θmo between the lens barrel 1 and the support 3. Subtract the variable Qn-1,
The result is stored in the variable ΔQ. Next, the variable Wn-1 that holds the value corresponding to the angular velocity ωm of the lens barrel 1 before sampling is subtracted from the variable Wn that holds the value corresponding to the current angular velocity ωm of the lens barrel 1 Is stored in the variable ΔW. Then, the following calculation (2) 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) (2) Here, in the above mixed calculation, the priority of each calculation is
() [Brackets], x [multiplication], / [division], + [addition],-[subtraction].

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,
It should be noted in advance that the delay element due to sampling and the frequency dependence of the low-pass filter 405 of the angular velocity detection circuit 12 in this figure can be sufficiently ignored in the frequency region described below, and are therefore omitted. Now, the angle θm of the lens barrel 1
The relative angle θmo between the angle θo and the support 3 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 (an output signal of the position detection circuit 11) that is KQ · AQ times θmo. KQ is the magnetic flux / 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 θm of the lens barrel portion 1 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 times AW is obtained. KW is the angular velocity of the angular velocity sensor 7
AW is a voltage conversion gain, and AW is a 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 the part surrounded by a broken line) of the arithmetic unit 501, and the result and the result are integrated with the gain 1 / Ta (block 1003). And the signal d multiplied by −K1 (block 1009) at the addition point at 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 is 1 (0 dB) in the frequency range of the first break point frequency f1 or lower, and becomes 2 (2 dB) above f1.
It is attenuated at -6dB / oct in the following frequency range, and is attenuated at -12dB / oct in the frequency range above f2. From Figure 11,
In the frequency range of f1 and above, the amount of transmission from the vibration of θo to the vibration of θm becomes small. The degree is represented by the difference ZdB between 0dB and the characteristic line (in this case at fr = 1Hz Z = 15dB).

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 anti-vibration characteristic of the image capturing apparatus is set to the characteristic shown in FIG. 11, the rotation angle θm of the lens barrel portion 1 hardly changes regardless of the change of the rotation angle θo of the support body 3, and the change of the shooting 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 (1) has the following meaning depending on the processing (En = En _- 1 + ΔE) in the next stage.

That is, the first term [-K1 * [Delta] W] in the equation (1) is a component provided to set the angular velocity .omega.m of the lens barrel portion to "0" and to keep the lens barrel portion 1 stationary. In the term [K2 × ΔQ] in the second term of the equation (1), the relative angle θmo between the lens barrel 1 and the support 3 is set to “0”, and the angle θm of the lens barrel 1 and the angle θo of the support 3 are almost equal to each other. It is a component that is provided to bring them into agreement. 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 to the angle θo of the support 3 is improved, and the vibration damping effect is diminished. Therefore, when the torque Tm generated by the actuator 5 according to the term [K2 × ΔQ] is small and the loss around the bearing of the actuator 5 is large, the generated torque Tm does not exceed the loss, and the lens barrel 1 and the support body The relative angle θmo of 3 does not reach "0". That is, there is a steady deviation between the angle θm of the lens barrel portion 1 and the angle θo of the support body 3, and the control of ωm = 0 is performed.
Therefore, the term [K2 × ΔT × Qn / T] in the second term of the equation (1)
a] is provided to compensate for the loss of the effect of the term [K2 × ΔQ] due to the bearing loss of the actuator 5 or the like. That is, the term [K2 × ΔT × Qn / Ta] is the next processing (En = E
n _- 1 + ΔE) has the meaning of an integral calculation of θmo 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 [K2 × ΔT × Qn / T
a] is added to the variable En. As a result, the term [K2 × ΔQ]
Even if the torque generated by the actuator 5 is smaller than the loss in the bearing, the term [K2 × ΔT × Qn / Ta] is added to En at each sampling, so the torque generated by the actuator 5 changes with time. It becomes larger than the bearing loss, and the steady deviation between θo and θm is eliminated.

Now, the control operation at the time of the next pan photographing will be described. First, since the lens barrel unit 1 is controlled to stand still as described above during still image capturing, the photographer operates the support 3 from this state (still image capturing) to start pan image capturing. If so, the lens barrel portion 1 is controlled so as to stand still without following the support body 3 (actually, the term [K2 ×
ΔQ] and the term [K2 × ΔT × Qn / Ta] move a little) The relative angle θmo between the lens barrel 1 and the support 3 gradually increases. However, when the absolute value of the relative angle θmo exceeds a predetermined value (corresponding to QPAN in FIG. 9A) by the photographing mode discrimination means 13 (process 803), it is discriminated to be pan photographing, and the control calculation is processed 805. Will be done by. In process 805, the control calculation is performed so that the angle θm of the lens barrel portion 1 smoothly matches the angle θo of the support body 3 and follows well. This will be described in detail below.

Each term in the mixed operation (2) is processed in the next stage (En
= En _- 1 + ΔE) has the following meanings.

That is, the first term of expression (2) [-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 processing 805 is always performed when it is determined to be pan shooting), this item is “0”. Therefore, the following equation (3)
To get

ΔW = ΔQ / Tw (3) The formula (3) can be rewritten as the following formula (4) from the above description.

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

(Wn-Wn _- 1) / [Delta] T = [Wn + (Qn-Qn _- 1) / [Delta] T-Wn] / Tw (5) Equation (5) is obviously a difference equation, and the limit [Delta] T of the sampling period [Delta] T → When 0 is taken, the equation (5) becomes a differential equation of the following equation (6) where t is time.

dWn / dt = (Wn + dQn / dt−Wn) / Tw (6) Here, 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 (6) can be rewritten as the following equation (7).

dωm / dt = (ωm + dθmo / dt−ωm) / Tw (7) Now, in the equation (7), the term [dθmo / dt] represents the relative angular velocity between the lens barrel portion 1 and the support 3. [Ωm + d], which is the sum of this term and the angular velocity ωm of the lens barrel 1.
θmo / dt] represents the angular velocity ωo of the support 3.
Therefore, the equation (7) becomes the following equation (8).

dωm / dt = (ωo−ωm) / Tw (8) When the differential equation (8) is taken with respect to ωm, the following equation (9) is obtained.
To get

ωm = ωo × (1−e ^{−t / TW} ) (9) That is, in the equation (9), 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 (2) gives the angular velocity command to the lens barrel 1. However, the term [−K3 × (ΔW−ΔQ /
Tw)] alone, the angle θm of the lens barrel 1 and the angle θ of the support 3
Since o does not match, the image forming mode determination means 13 is shifted by the difference at the time when the image capturing mode determining means 13 determines the pan image capturing. Therefore, in the term [K4 × ΔQ], the relative angle θmo between the lens barrel 1 and the support 3 is set to “0”, and the angle θm of the lens barrel 1 and the angle θ of the support 3 are set.
₀ is provided to make them substantially coincident. But,
When 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 3 at the time of detecting the pan photographing sharply becomes “0”.
Therefore, the photographed screen suddenly flows, which makes the photographer feel uncomfortable. vice versa,
When the gain K4 is decreased, the torque Tm generated by the actuator 5 due to the term [K4 × ΔQ] is small, and when there is a bearing loss of the actuator 5, the angle θm of the lens barrel portion 1 and the angle θo of the support body 3 match. Does not reach. Therefore, the term [K4 × ΔT × Qn / Tp] is provided. This term [K4 × ΔT
× Qn / Tp] means the integral calculation of the relative angle θmo between the lens barrel 1 and the support 3 by the next process (En = En _- 1 + ΔE), and the angle θm of the lens barrel 1 and the support 3 The stationary deviation from the angle θo of is compensated. That is, if there is a steady deviation between θo and θm, [K4 × Δ
T × Qn / Tp] is added to the variable En. As a result, the term [K4
× ΔQ] even if the torque generated by the actuator 5 is smaller than the bearing loss, the term [K4 × ΔT × Qn / T
Since p] is added to En at each sampling, the torque generated by the actuator 5 increases with time, overcoming the bearing loss, and eliminating the steady deviation between θo and θm.

Now, with reference to FIG. 12, the movement of the angle θo of the support body 3 and the angle θm of the lens barrel portion 1 when the photographer operates the photographing apparatus of the present embodiment in the states of still photographing, pan photographing, and still photographing again. It demonstrates using. FIG. 12 shows the angle θo of the support body 3 when the photographer operates the photographing apparatus of the present embodiment in the order of the still photographing, the pan photographing, and the still photographing again.
And the movement of the lens barrel portion 1 at an angle θm. Curve 12
01 indicates the movement of the support body 3 at the angle θo, and the photographer performs still photography until time t1, pan photography starts from this time (t1), and still photography again at time t3. Indicates. A curve 122 shows the movement of the lens barrel portion 1 at the angle θm. When the pan photographing is started at time t1, at this time, the photographing apparatus of the present embodiment is still discriminated as the still photographing by the photographing mode discrimination means 13 (process 803). Although it moves slightly, the followability to the support 3 is poor and the relative angle θmo between the lens barrel 1 and the support 3 increases. Eventually, at time t2, when the relative angle θmo between the lens barrel portion 1 and the support body 3 increases to a value with respect to θPAN defined in the process 803, the process 803 discriminates the pan photographing and 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 1 slightly exceeds the angle θo of the support 3 (overshoot). This is the integral term [K1 × Δ of the mixed operation (2) in process 805.
T × Qn / Tp], but the degree of the overshoot is slight and the photographer does not feel uncomfortable.

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 apparatus 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 photographing apparatus of the present invention does not require the counterweight of the lens barrel portion, which is 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. Further, the photographing apparatus of the present invention has a photographing mode discrimination means, and achieves both the vibration-proof effect required for still photographing and the good followability required for pan photographing. Therefore, if, for example, a video camera is constructed based on the present invention, a compact, lightweight, 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 an angular velocity of FIG. FIG. 5 is a configuration diagram showing a specific configuration of the detection circuit, FIG. 5 is a configuration diagram showing a specific configuration of the photographing mode discrimination means and the control calculation means of FIG. 1, and FIG. 6 is an A / D conversion of FIG. 7 is a circuit diagram showing the specific configuration of the drive unit, FIG. 7 is a circuit diagram showing the specific configuration of the drive circuit of FIG. 1, and FIG. 8 is a built-in program stored in the ROM area of the memory of FIG. 9 is a basic flowchart of FIG. 9, FIG. 9 is a detailed flowchart of the process of FIG. 8, and FIG.
FIG. 11 is a block diagram for explaining the operation of the figure, FIG. 11 is a Bode diagram for explaining the operation of FIG. 1, FIG. 12 is an operation explanatory diagram for explaining the operation of FIG. 1, and FIG. It is a block diagram of the conventional imaging 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 ... Angular velocity detection circuit, 13 ... Shooting mode discrimination means, 14 ...... Control calculation means, G ・ ・ ・ Center of gravity of the lens barrel 1, 16 ・ ・ ・
… Drive circuit, 501 …… Computer, 502,503 …… A / D converter,
504 ... Memory, 505 ... D / A converter.

Claims (4)

[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 rotation axes that are substantially orthogonal to each other, an actuator that is mounted between the lens barrel portion and the support body, and that drives the lens barrel portion to rotate, and the mirror. Relative angle detecting means for detecting a relative angle between the cylindrical portion and the support, angular velocity detecting means for detecting an angular velocity of the lens barrel around the rotation axis, and drive for supplying electric power proportional to a command input to the actuator. Circuit,
When the absolute value of the output of the relative angle detection means exceeds the first predetermined value, it is determined to be moving photography such as pan photography or tilt photography, and the absolute value of the output of the relative angle detection means is the second predetermined value. Is smaller than the above value and the absolute value of the output of the angular velocity detecting means is smaller than the third predetermined value for a predetermined time or more, the shooting mode determining means determines the still shooting and the shooting mode determining means. When it is determined that the means is still photography, the output of the relative angle detection means, the result of the integral calculation of the output of the relative angle detection means, and the output of the angular velocity detection means are respectively set to a first predetermined gain. When the photographing mode discriminating means discriminates that the photographing is a moving photographing, the output of the relative angle detecting means and the output of the relative angle detecting are added. The result obtained by dividing the output of the relative angle detecting means by an integral calculation with the result obtained by dividing the output of the relative angle detecting means by the second predetermined gain An image pickup apparatus, comprising: a control calculation unit that takes the result as a command input to the drive circuit. 2. The photographing apparatus according to claim 1, wherein the rotation axis of the actuator passes through the center of gravity of the lens barrel portion 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 vibration gyro is used as the angular velocity detecting means. 4. The transmission characteristic of the rotation angle of the lens barrel portion relative to the rotation angle of the support is set to 1 in the frequency range of the first break point frequency f1 or lower, and is set to the second break point frequency f2 (f1 or higher when f1 or higher. <
The image pickup apparatus according to claim 1, wherein attenuation is performed at -6 dB / oct in a frequency range of f2) or less and attenuation is performed at -12 dB / oct in a frequency range of f2 or more.