JPH0640663B2 - Imaging device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus having an anti-vibration mechanism that minimizes vibration of a lens barrel regardless of vibration of a support (main body case). Provided is a compact and lightweight photographing device that can be used in a portable video camera or the like.

2. Description of the Related Art As a conventional anti-vibration mechanism, an anti-vibration mechanism that suppresses transmission of vibration from a support table to a surface plate or the like by air pressure or hydraulic pressure is widely used. FIG. 16 is a sectional view showing the structure of such a conventional vibration damping mechanism.

In FIG. 16, an air chamber 505 is formed between the surface plate 501 and the support No. 502, and compressed air is sent from the air compressor 504 through the pipe 503. as a result,
An air layer having a very weak spring property is formed between the surface plate 501 and the support 502. Therefore, even if the support 502 vibrates significantly, the vibration is hardly transmitted to the surface plate 501.

Problems to be Solved by the Invention In such a conventional vibration isolation mechanism, since the compressed air is used, the air chamber 505 is necessary, and the shape becomes large. Moreover, a compressor is required, which makes a loud noise and requires a large installation area. Therefore, such a conventional image stabilization mechanism cannot be used for image stabilization of a portable video color.

In consideration of such a point, the present invention newly developed a photographing device having a small, lightweight, and high-performance anti-vibration mechanism that can be used for a portable video camera.

Means for Solving the Problems An image pickup apparatus of the present invention includes a lens barrel section having a plurality of lenses and an image pickup element mounted thereon, image signal processing means for generating an image signal from an electric signal obtained by the image pickup element, and A support body that rotatably supports the lens barrel section around a rotation axis that is orthogonal or substantially orthogonal to the axis of the light beam incident on the lens barrel section, and is mounted between the lens barrel section and the support body. Actuator means for rotationally driving the lens barrel portion, position detecting means for detecting a relative angle between the lens barrel portion and the support, angular velocity detecting means for detecting an inertial angular velocity of the lens barrel portion around the rotation axis, and the position A synthesizing means for synthesizing the output signal of the detecting means and the output signal of the angular velocity detecting means, a driving means for supplying electric power to the actuator means so as to suppress the variation of the synthetic signal output by the synthesizing means, and the position detecting means. The pan for detecting the start of the panning operation when the output signal of the means is out of the first predetermined range, and for detecting the end of the panning operation when the output signal of the angular velocity detecting means is in the second predetermined range. The position detection unit compares the detection gain of the position detection unit and the detection gain of the angular velocity detection unit with an output signal of the movement detection unit and the pan detection unit, and compares the detected gain of the position detection unit with the gain of the angular velocity detection unit. The above-mentioned object is achieved by the provision of a gain correcting means for making the gain of (1) relatively large.

With the above-described structure, the present invention detects the relative position of the lens barrel and the support and the angular velocity of the lens barrel, and drives the lens barrel by actuator means so as to suppress fluctuations in both. The vibration of the lens barrel is controlled and greatly reduced. Furthermore, by changing the relative ratio of the detection gain of the position detection means and the detection gain of the angular velocity detection means during the panning operation by the gain correction means, the delay of the movement of the lens barrel portion during the panning operation is made sufficiently small in practical use, The lens barrel portion and the support are prevented from colliding with each other, and the following movement of the lens barrel portion is smoothed.

Embodiment FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, a large number of lens groups (not shown) and an image pickup device 41 (for example, a CCD plate or an image pickup tube) are attached to a lens barrel portion 1 of an image pickup apparatus (video camera), and reflected light from a subject is reflected. The light is condensed to form an image on the image sensor 41 and converted into a charge signal (electrical signal). The image signal processor 42 sequentially reads out the charge signals obtained by the image sensor 41,
The image signal (video signal) of the method is produced. The actuator 3 arranged between the lens barrel portion 1 and the main body case 2 (support portion) has the lens barrel portion 1 with the rotation axis 4 as the center of rotation.
Is rotationally driven in a predetermined direction (yaw direction) (in the use state, the lens barrel portion 1 is rotatable about a horizontal plane as a corresponding direction). Rotation axis 4 of actuator 3
Is rotatably supported by the main body case 2 through the center of gravity G of the lens barrel portion 1. Although not shown in the drawings, the main body case 2 is provided with a grip portion that is manually supported by the operator of the photographing apparatus.

2 (a), (b), and (c) show a concrete configuration of the actuator 3. In FIG. 2, the back yoke 101 made of a ferromagnetic material of the magnet 102 is attached to the lens barrel portion 1 and rotates together with the rotating shaft 4. The magnet 102 is magnetized to have four poles and generates a magnetic field flux. Bearing 107 of rotating shaft 4
Is attached to the coil yoke 103, the coil 104
The a and 104b and the Hall element (magnetic sensing element) 5 are fixed.
In this example, the magnet 102 is attached to the lens barrel portion 1 and the coil yoke 103 is attached to the main body case 2 (note that this relationship may be reversed). coil
104a and 104b are connected in series, and a rotational torque is generated by the current flowing from the terminals 105 to 106 and the magnetic flux of the magnet 102. The Hall element 5 is the magnet 102.
Of the magnet 102 (the angular position θ _m of the lens barrel 1) and the coil yoke 103 (the angular position θ _x of the main body case 2) (θ _h = θ). generate an output signal corresponding to ( _x − θ _m ).
Note that θ _m is the angle of the lens barrel portion 1 around the rotation axis 4 when viewed from the absolute space coordinate system (inertial coordinates), and θ _x is the angle of the main body case 2 around the rotation axis 4 when viewed from the same inertial coordinates. Is.

The output signal a of the Hall element 5 that detects the magnetic flux of the magnet 102 of the actuator 3 is input to the position detector 11. FIG. 3 shows a specific configuration of the position detector 11. The DC signal obtained at the two output terminals of the Hall element 5 is supplied to the operational amplifier 111 and the resistors 112, 113, 114, 115.
Is differentially amplified a predetermined number of times by a differential amplifier circuit consisting of to obtain an output signal c.

Further, an angular velocity sensor 6 composed of a vibration type gyro is attached to the lens barrel portion 1 by a fixing member 7. The detection axis of the angle sensor 6 coincides with the rotation axis 4 of the actuator 3, and outputs the output signal b in response to the rotational angular velocity (that is, the inertial angular velocity) of the lens barrel portion 1 around the rotational axis 4 in the inertial coordinates. The output signal b of the angular velocity sensor 6 is input to the angular velocity detector 12, and is proportional to the angular velocity ω _m (that is, the inertial velocity ω _m ) around the rotation axis 4 of the lens barrel portion 1 viewed from the inertial coordinate, or a predetermined angular velocity ω _m . A signal d proportional to the frequency range component is obtained. FIG. 4 shows a specific configuration of the angular velocity detector 12. The forced vibration circuit 133 has a sine wave oscillating circuit of a predetermined frequency (1 kHz), and forcibly vibrates the drive element 131 made of the piezoelectric element of the angular velocity sensor 6 by the oscillating frequency signal. The sense element 132 made of a piezoelectric element is a drive
Because it is placed in mechanical contact with element 131, it vibrates at the same frequency as drive element 131. At this time, when the lens barrel 1 rotates about the rotation axis 4 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 132, it is proportional to the product of the angle ω _m about the rotation axis 4 of the lens barrel portion 1 in inertial coordinates and the angular velocity due to forced vibration. The sense element 132 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 132 is synchronously detected by the synchronous detection circuit 134 at the same frequency as the forced vibration, and the low-pass filter 135 extracts the low frequency component (DC to 100 Hz) of the detected output. A signal proportional to the angular velocity ω _m around the rotation axis 4 (that is, the inertial angular velocity ω _m ) is obtained.

The output signal c of the position detector 11 and the output signal d of the angle detector 12 are combined in the combiner 13 to obtain a combined signal e. The synthesizer 13 includes A / D converters 21 and 22, an arithmetic unit 23, a memory 24, and a D / A converter 25. The A / D converter 21 produces a digital signal p corresponding to the value of the output signal c of the position detector 11. Further, the A / D converter 22 produces a digital signal q corresponding to the value of the output signal d of the angular velocity detector 12. The arithmetic unit 23 operates according to a predetermined internal program, which will be described later, stored in the ROM area (read-only memory area) of the memory 24, and operates the digital signal p of the A / D converter 21 and the digital signal of the A / D converter 22. The signal q is taken into the RAM area (random access memory area), subjected to a predetermined calculation and then combined, and the combined digital signal w is output to the D / A converter 25 to obtain a combined signal e.

The A / D converters 21 and 22 preferably have a sequential conversion type configuration. FIG. 5 shows a specific configuration of the successive conversion A / D converter 21 (the same applies to the A / D converter 22). Input signal c and D / A conversion circuit 147
The output signal m of is compared by the comparator 141,
A comparison signal n corresponding to the magnitude relation is obtained. The oscillator circuit 145 generates clock pulse 1 having a predetermined frequency. The signal h from the calculator 23 is normally "H" (high potential state), and becomes "L" (low potential state) when the digital signal p is read. Therefore, the inverter circuit 142 and the AND circuits 143 and 144 output the clock pulse 1 to the counter circuit 1 according to the comparator signal n.
The signal is input to the down pulse input terminal D or the up pulse input terminal U of 46 (when the signal h is "H"). The counter circuit 146 subtracts the internal state one by one according to the input pulse to the down pulse input terminal D and increments the internal state one by one according to the input pulse to the up pulse input terminal U. The internal state of the counter circuit 146 is output as a digital signal p, and the D / A converter 147 converts it into an analog signal m corresponding to the digital signal p.
As a result, the digital signal p of the counter circuit 146 becomes a value corresponding to the input signal c.

The computing unit 23 sets the signal h to "L" for a predetermined short time to stop the operation of the counter circuit 146 and read the stable digital signal p. Similarly, the computing unit 23
Sets the signal k to "L" for a predetermined short time to read a stable digital signal q.

The output signal e of the D / A converter 25 of the combiner 13 is the driver 1
4 and the voltage signal (or current signal) f proportional to the signal e is supplied to the coils 104 a and 104 b of the actuator 3. FIG. 6 shows a specific configuration of the driver 14.
The operational amplifier 151, the transistors 154 and 155, and the resistors 152 and 153 form a power amplifier circuit, and a signal e
To output a voltage signal f amplified by a predetermined number.

The built-in program of the arithmetic unit 23 will be described. FIG. 7 shows a basic flowchart thereof, and FIGS. 8 (a) to (f) show detailed flowcharts of respective parts. First, the basic flow chart of FIG. 7 will be described (note that the numbers from to represent nodes and correspond to the numbers in FIG. 8).

[1] <Control operation at rest> 181 (corresponding to combining means): This corresponds to a method of creating a combined signal when a stationary subject is photographed.

[2] <Pan start detection> 182 (corresponding to the pan start detection means in the pan operation detection means): The start of the panning operation is detected, the operation moves to [3] when the panning operation is performed, and [1] when the panning operation is not performed. Return to.

[3] <Gain setting> 183 (corresponding to gain setting means in pan operation detecting means): The control gain is set according to the situation at the time of detecting the start of the panning operation.

[4] <Control operation during panning> 184 (corresponding to synthesizing means): This corresponds to the method of creating a synthetic signal during panning operation.

[5] <Gain correction> 185 (corresponding to gain correction means):
The control gain is corrected according to the movement of the lens barrel portion 1 during the panning operation. In particular, the relative ratio is increased or decreased by changing the synthesis ratio of the digital signal from the position detector 11 and the digital signal from the angular velocity detector 12.

[6] <Pan end detection> 186 (corresponding to the pan end detection unit in the pan operation detection unit): The end of the panning operation is detected, and when the panning operation is continued, the procedure returns to [4] and the panning operation ends. When you do, return to [1].

In this embodiment, <pan start detection> 182 (pan start detection means) and <gain setting> 183 (gain setting means).
And <pan end detection> 186 (pan end detection means) constitute pan operation detection means (<gain setting>
183 (gain setting means) is not always necessary).

Next, an operation flowchart of each unit will be described. FIG. 8 (a) shows a flowchart of <control operation at rest> 181.

[11] Waiting for an interrupt from the timer. The timer generates an interrupt signal every predetermined time (T ₁ = 5 msec), and when an interrupt occurs, the process proceeds to [12].

[12] The signal h is set to "L" for a predetermined short time, the digital signal p is input, and stored in the variable Pn.

[13] The signal k is set to "L" for a predetermined short time, the digital signal q is input, and stored in the variable Qn.

[14] Subtract a predetermined reference value Pr from Pn (P = Pn-Pr),
A digital value P corresponding to the relative angle θ _h between the lens barrel 1 and the support 2 is calculated. Similarly, a predetermined reference value Qr is subtracted from Qn (Q = Qn-Qr), and a digital value Q corresponding to the angular velocity ω _m of the lens barrel 1 viewed from the inertial coordinate is calculated. The calculation formula means that the calculation result on the right side is stored in the variable on the left side.

[15] The synthesis ratio D is set to 1 (the synthesis ratio D is directly related to the relative ratio). P is multiplied by D and added and combined with Q to obtain a combined digital value E (E = D * P + Q, where * means multiplication).

[16] E is output to the D / A converter 25, and the analog signal e
Convert to.

[17] Add 1 to the count variable N with N1 as mod (N = N + 1 (mod N1)). That is, 1 is added to N to newly store it in N, and if the value of N is equal to N1, N is set to 0. Here, N1 = 10.

[18] If N is not 0, return to [11], and if N is 0, move to [21] of <pan start detection> 182. That is, <pan start detection> 182 every N1 * T1 = 50 msec.
Are doing.

FIG. 8B shows a flowchart of <pan start detection> 182.

[21] Subtract Px from P and store in variable V (V = P−
Px). A value obtained by multiplying P by H1 (H1 is a constant) and a value obtained by multiplying V by H2 (H2 is a constant) are added and stored in a variable W (W = H1 * P + H2 * V). Make P a new Px (Px
= P). That is, Px is the value of P before N1 * T1 hours, and V corresponds to the relative angular velocity (differential value of the relative angle θ _h ) between the lens barrel 1 and the main body case 2. Therefore, W is a combined value of the relative angle θ _h (P) and the relative angle (V).

[22] | P | <P1 (P1 is a constant) <Control operation at rest> Return to [11] in 181. If | P | <P1, go to [23].

[23] If | P |> P2 (P2 is a constant larger than P1), <Gain setting> Go to [31] of 183, | P |>
If not P2, go to [24].

[24] If | W |> W1 (W1 is a constant), move to <Gain setting> [31] of 183. If not | W |> W1, <Control operation at rest> [11] of 181. Go home.

In [22] to [24] of <Pan start detection> 182 described above, the start of the panning operation is detected by the digital value P corresponding to the relative angle θ _h and the digital value V corresponding to the relative angular velocity. FIG. 9 shows a detection area of the start of the panning operation by P and V (hatched portion in the figure). The line a corresponds to | P | = P1, and the line b corresponds to | P | = P.
2 and the line c corresponds to | W | = W1. Depending on the values of P and V, it is determined that the panning operation has started when entering the shaded portion in the figure. That is, the relative angle θ _h between the lens barrel 1 and the main body case 2 is outside the predetermined range (| P |> P
2) or when the relative angle θ _h is outside the predetermined range (| P |> P1), the combined value (W) of the relative angle θ _h and the relative angular velocity is outside the predetermined range (| W |> W1 ), The start of the panning operation is detected. The dotted line in FIG. 9 represents the end of the movable limit, and | P | P
1im means a collision between the lens barrel portion 1 and the main body case 2.

FIG. 8 (c) shows a flowchart of <gain setting> 183.

[31] | P | to P3 (P3 is a constant such that P3 ≦ P2)
The value obtained by subtracting is multiplied by K1 (K1 is a constant including 0), and | V |
The value obtained by subtracting V1 (V1 is a constant) from is multiplied by K2 (K2 is 0
, And add them to obtain a composite ratio D (D
= K1 * (| P | -P3) + K2 * (| V | -V
1)). That is, a value corresponding to the relative angle θ _h or (and) the relative angular velocity at the time of detecting the start of the panning operation is set as the initial value of the composite ratio D (initial value setting means).

[32] When D is smaller than D1, D is set to D1 (lower limit value limiting means). Here, D1 is a constant of about 1, for example, D1 = 1.

[33] When D is larger than D2, D is set to D2 (upper limit limiting means). Here, D2 is a constant that is significantly larger than 1, for example, D2 = 25.

FIG. 8 (d) shows a flowchart of <control operation during panning> 184.

[41] Waiting for an interrupt from the timer. The timer generates an interrupt signal every predetermined time (T1 = 5 msec), and when an interrupt occurs, the process proceeds to [42].

[42] The signal h is set to "L" for a predetermined short time, the digital signal p is input, and stored in the variable Pn.

[43] The signal k is set to "L" for a predetermined short time, the digital signal q is input, and the digital signal q is stored in the variable Qn.

[44] Subtract a predetermined reference value Pr from Pn (P = Pn-pr),
A digital value P corresponding to the relative angle θ _h between the lens barrel 1 and the support 2 is calculated. Similarly, a predetermined reference value Qr is subtracted from Qn (Q = Qn-Qr), and a digital value Q corresponding to the angular velocity ω _m of the lens barrel 1 viewed from the inertial coordinates is calculated.

[45] Multiply the synthesis ratio D by P and then add and synthesize with Q to obtain a synthetic digital value E (E = D * P + Q).

[46] E is output to the D / A converter 25, and the analog signal e
Convert to.

[47] The count variable N is incremented by 1 with N2 as mod (N = N + 1 (mod N2)). That is, N is incremented by 1 and stored in N, and if the value of N is equal to N2, N is set to 0.
To Here, N2 = 10.

[48] If N is not 0, return to [41], and if N is 0, shift to <51> of <gain correction> 185. That is,
<Gain correction> 185 is performed every N2 * T1 = 50 msec.

The above <control operation during panning> 184 and <control operation during rest> 181 basically perform the same control operation, but the value of the synthesis ratio D is significantly different.

FIG. 8 (e) shows a flowchart of <gain correction> 185.

[51] Subtract Px from P and store in V (V = P-Px).
Let P be the new Px (P = Px). The variable S is set to 1 when the sign of P is positive, S is also set to 0 when P is 0, and S is set to -1 when the sign of P is negative (S = sgn (P)). Multiply S and V to obtain Y (Y = S * V). That is, V becomes a value corresponding to the relative angular velocity (differential value of the relative angle θ _h ). Also, Y is | V | when the sign of P and the sign of V match.
And the sign of P and the sign of V are different,
Is equal to | V |.

[52] When Y ≧ Y1 (Y1 is a negative constant including 0), go to [53], and when Y2 <Y <Y1 (Y2 is a negative constant), go to [61] of <pan end detection> 186. , Y ≦ Y2
In case of, go to [54].

[53] Multiply the composition ratio D by M1 to obtain a new D (D = D *
M1). Here, M1 is a constant greater than 1, for example, M1 = 1.1. That is, the synthesis ratio D is increased by the predetermined ratio M1. After that, when D is larger than D2, D is set to D2 (upper limit limiting means). next,
<Detection of end of pan> Go to [61] of 186.

[54] The synthesis ratio D is reduced to M1 / 1 / thick to obtain a new D (D
= D / M1). That is, the synthesis ratio D is made smaller by the predetermined ratio M1. After that, when D is smaller than D1, D is set to D1 (lower limit value limiting means). Next, go to [61] of <end of bread> 186.

In the above-mentioned <correction of gain> 185, the synthesis ratio D (relative ratio) is increased or decreased according to the digital value V corresponding to the relative angular velocity. In particular, when the signs of V and P are the same, the composition ratio D is increased, and when the signs of V and P are different and | V | is larger than a predetermined value (-Y2), the composition ratio D is large. Is small.

FIG. 8 (f) shows a flowchart of <pan end detection> 186.

[61] | Q | <Q1 (Q1 is a constant), go to [62], and if not | Q | <Q1, return to [41] of <control operation during panning> 184.

[62] If | P | <P4 (P4 is a constant), go to [63]. If not | P | <P4, return to [41] of <control operation during panning> 184.

[63] When | V | Go home.

In the above-described <pan end detection> 186, the angular velocity ω _m of the lens barrel portion 1 viewed from the inertial coordinate is within a predetermined range (| Q | <Q1).
The relative angle θ _h between the lens barrel 1 and the main body case 2 is within a predetermined range (| P | <P4), and the relative angular velocity (differential value of the relative angle θ _h ) is within a predetermined range (| V Since | <V2), the end of the panning operation is detected.

Next, the anti-vibration characteristics of the image taking apparatus will be described. Tenth
In the control block diagram of the figure, the relative angle θ _h of the angle θ _m of the lens barrel portion 1 and the angle θ _x of the main body case 2 as viewed from the inertial coordinates
θ _x −θ _m is easily detected by the Hall element 5 that detects the magnetic field of the magnet 102 of the actuator 3.
The hall terminal 5 and the position detector 11 are represented by a block 204, and a signal c (output signal of the position detector 11) of B times θ _h is obtained. On the other hand, the angular velocity ω _m of the lens barrel portion 1 viewed from the inertial coordinates is detected by the angular velocity sensor 6 and the angular velocity detector 12, and is represented by the cascade connection of blocks 205 and 206. That is, the angular velocity sensor 6 and the synchronous detection circuit 11
34 detects a signal obtained by multiplying ω _m by −A (block 205), and _h = ω _h by the low-pass filter 135.
/ 2π = 100Hz or higher high-frequency ripple voltage is reduced.
It is removed (block 206), and the signal d of the frequency component (DC to 100 Hz) that requires the fluctuation of ω _m is extracted. The combiner 13 is represented by a block 207 and an addition point 208, which multiplies the signal c by D and then adds and combines it with the signal d to obtain a combined signal e. In the block 209 corresponding to the driver 14, the signal e is amplified C times and the voltage signal f
To get In the block 210 corresponding to the actuator 3, the voltage signal f is converted into the torque Tm. here,
R is a combined resistance value of the coils 104a and 104b, and Kt is a torque constant. A block 201 represents the transmission from the torque Tm to the angular velocity ω _{m due} to the mechanical moment of inertia Jm of the lens barrel portion 1, and a block 202 represents the relationship between ω _m and θ _m . Here, s means the Laplace operator.

Now, in the transfer function from the angular velocity ω _m to the signal d, the term (block 206) related to frequency is set as F (s) = {ω _h / (s + ω _h )} (1), and L = C・ (Kt / R) ・ (1 / Jm)…
… (2), the transfer function from θ _x to θ _m is G (s) = θ _m / θ _x ＝ (B ・ D ・ L) / {s ・ s + F (s) ・ A ・ L ・s + B / D / L}

(3) Where ω ₁ = 2π · ₁ = (B · D) / A
…… (4) ω ₂ = 2π ・₂ ＝ A ・ L
…… (5), ω ₁ = 2π · ₁ << ω ₂ = 2π · ₂
…… (6) ω _h = 2π · _h >> ω ₂ …… (7). Actually, ₁ = 0.1Hz, ₂ = 10Hz,
_h = 100Hz.

In this case, since F (jω) = 1 in the frequency range of ₁ to ₂ , the frequency transfer function G (j
The broken line approximation board characteristics of ω) are as shown in FIG. That is, the transfer characteristic G (jω) of the rotation angle θ _m of the lens barrel portion 1 with respect to the rotation angle θ _x of the main body case 2 in the inertial coordinate is
_{1 in} the frequency range below the first break frequency 1
It becomes (0 dB) (line), and at ₁ or more, the second break frequency
The ₂ following frequency ranges attenuated by -6 dB / oct (line), ₂ or more in the frequency range are attenuated by -12 dB / oct (line) (This characteristic, ₂ ≧ 6 · _1,
obtained if _h ≧ 3 · _2).

Transmission of vibration of theta _m from the vibration of FIG. 11 from, theta _x in _one or more frequency ranges is reduced. The degree is 0 dB
It is represented by the difference ZdB between the (line) and the characteristic line.

FIG. 12 shows the measurement result of the fluctuation of the rotation angle θ _x of the main body case in the yaw direction at the time of shooting with a shooting device (video camera) without a vibration isolation mechanism (spectrum analysis). This corresponds to the fluctuation of the rotation angle θ _z of the main body case 2 when the operator holds the photographing device in his hand and stands still on the ground and photographs a stationary subject. From this, it can be seen that the variation in the range of 0.5 Hz to 5 Hz is large. Therefore, if the anti-vibration characteristic of the present photographing device is set to the characteristic shown in FIG. 11, the rotation angle θ _m of the lens barrel portion 1 hardly changes regardless of the fluctuation of the rotation angle θ _z of the main body case 2, and the photographing screen It can be seen that the fluctuation of is extremely small. That is, stable and easy-to-view video shooting becomes possible. In particular, the effect can be obtained by setting ₁ ≤ 0.5 Hz.

Further, in this embodiment, since the built-in program of the synthesizer 13 has the pan operation detecting means and the gain correcting means, even if the high-speed panning operation is performed in the present photographing apparatus, the lens barrel portion 1
It is possible to prevent a collision between the main body case 2 and Next, this will be described.

When photographing a moving subject with a photographing device (video camera), the operator keeps the subject off the photographing screen while rotating about the rotation axis (this kind of operation is called a panning operation). During the panning operation, the photographing device is rotating in the yaw direction in the inertial coordinates. At this time, since the image-taking apparatus is performing the image stabilization operation having the characteristic as shown in FIG. 11, the follow-up operation of the rotation angle θ _m of the lens barrel portion 1 is considerably performed with respect to the increase of the rotation angle θ _x of the main body case 2. Be late. First, the synthesis ratio D of the synthesizer 13
Described below is the drawback when D is constant (D = 1). First
As can be seen from FIG. 1 and equation (4), the addition point 208
The smaller the relative ratio B ・ D / A between the detection gain BD of the relative angle θ _h and the detection gain A of the angular velocity ω _m is, the smaller ₁ is, and the vibration isolation characteristics are improved. Therefore, the relative ratio is considerably small. It is necessary to select it. That is, it is necessary to set the detection gain B small. However, when the detection gain B of the position detector 11 is reduced, the torque Tm generated by the actuator 3 is reduced.
At most, only a small torque corresponding to B · θ _h1 (θ _h1 is the value of the relative angle θ _h corresponding to the end of the movable limit) can be generated. If the torque Tm generated by the actuator 3 is small, the acceleration of the lens barrel portion 1 becomes small, and the increase in the rotation angle θ _m of the lens barrel portion 1 is greatly delayed with respect to the increase in the rotation angle θ _x of the body case 2 due to the panning operation. Like As a result, the main body case 2 and the lens barrel 1 are moved to the movable end (| θ _h
A collision occurred at │ = θ _h1 ), and the operator felt an impact force due to the collision. Such a collision is likely to cause damage to the photographing device and gives an operator an unpleasant feeling, and should be avoided as much as possible.

In this embodiment, the panning operation detecting means detects that the panning operation is in progress, and the gain correcting means changes the synthesis ratio D in accordance with the digital value V corresponding to the relative angular velocity, thereby increasing or decreasing the relative ratio B · D / A. I am letting you. As a result, the relative ratio BD / A during the panning operation becomes larger than the relative ratio B / A during the control operation at rest, the torque Tm generated by the actuator 3 also increases, and the rotation speed of the main body case 2 due to the panning operation. The barrel portion 1 can be accelerated sufficiently following the increase in θ _x . As a result, a collision between the lens barrel portion 1 and the main body case 2 can be prevented.

Next, this will be described in more detail. The pan start detecting means of the pan operation detecting means uses the digital value P corresponding to the relative angle θ _h between the lens barrel portion 1 and the main body case 2 and the digital value V corresponding to the relative angular velocity so that the relative angle θ _h falls outside the predetermined range. Or the composite value of the relative angle and the relative angular velocity is out of the predetermined range, the start of the panning operation is detected. When the panning operation is not performed (when a stationary subject is photographed), the relative angle θ _h slightly changes within a predetermined narrow range, and the relative angular velocity is small. That is, the absolute values of the digital values P, V, W are sufficiently small, and the calculator 23
Repeats <control operation at rest> 181. Further, the composition ratio D is 1.

Assuming that the panning operation is started in such a state, the lens barrel portion 1 will increase despite an increase in the body case θ _x.
Since the angle θ _m does not change, the absolute value of the relative angle θ _h increases and the absolute value of the relative angular velocity also increases. as a result,
<Pan start detection> In 182, the digital values P and V enter the panning operation start detection area in FIG. 9, and the panning operation is detected.

<Setting of gain> In 183, the composite ratio D corresponding to P and V at the start of the panning operation is set, and <
Control operation at the time of panning> Move to the control operation of 184. Normally, the synthesis ratio D is given a value larger than 1 as an initial value.

<Correction of gain> In 185, the composite ratio D is corrected by observing the degree of change of the digital value P corresponding to the relative angle at the next time from the value of the digital value V corresponding to the relative angular velocity at that time. . For example, if V has the same sign as P, the synthetic ratio D is increased to increase the torque Tm generated by the actuator 3 (a torque related to D · P is generated). Therefore, the lens barrel portion 1 is accelerated by a sufficiently large acceleration, and the velocity θ _x of the body case 2 due to the panning operation is increased.
The angle θ _m of the lens barrel portion 1 increases almost in accordance with the increase.
As a result, a collision between the lens barrel portion 1 and the main body case 2 is prevented. That is, the increase of | P | is suppressed, and conversely | P |
Will be reduced.

When V and P have different signs and their absolute value | V | is larger than a predetermined value (| Y2 |), the synthesis ratio D is reduced to reduce the degree of decrease of | P |. . As a result, | P | gradually decreases toward 0, preventing rapid movement of the shooting screen. That is, the movement of the photographing screen during the panning operation becomes smooth, and the screen becomes very easy to see.

During the panning operation, since the composition ratio D is large, the angle θ _m of the lens barrel portion 1 also increases following the increase in the angle θ _x of the main body case 2 due to panning. That is, the angular velocity ω _m of the lens barrel portion 1 matches or substantially matches the angular velocity of the body case 2 (as viewed from the inertial coordinate) due to panning,
ω _m is outside the predetermined range (| Q |> Q1).

After the panning operation is completed, the operator of the photographing apparatus shifts to photographing a normal still subject. When the panning operation is completed, the angle θ _x of the main body case 2 hardly changes, so that the angle θ _m of the lens barrel portion 1 also tries to stay at a value that matches θ _x . Along with this, the angular velocity θ _m of the lens barrel portion 1 becomes a small value within a predetermined range or becomes 0, and the relative angle θ _h and the relative angular velocity also settle at small values.
That is, the absolute value of the digiter value Q corresponding to the angular velocity ω _m of the lens barrel portion 1 becomes smaller than Q1 (| Q | <Q
1), the absolute value of the digital value P corresponding to the relative angle θ _x between the lens barrel portion 1 and the main body case 2 becomes smaller than P4 (|
P | <P4), the absolute value of the digital value V corresponding to the relative angular velocity of the lens barrel 1 and the main body case 2 becomes smaller than V2 (| V | <V2). As a result, <pan end detection> 18
In step 6, the end of the panning operation is detected, and the process proceeds to <control operation at rest> 181.

Thereafter, the <control operation at rest> 181 is continued until the next panning operation is started. Further, when the next panning operation occurs, the <pan start detection> 182 detects it according to the above-described operation, moves to <control operation at panning> 184, and ends the panning operation by <pan end detection> 186. Until the detection, <control operation during panning> 184 is performed.

In the above-described embodiment, the combination ratio D is increased or decreased at a predetermined ratio in <Gain modification> 185, but the present invention is not limited to such a case. FIG. 13 (a) shows another example of <gain correction> 185 flowchart. In this example, the synthesis ratio D is increased or decreased by a predetermined value. This will be described.

[101] Subtract Px from P and store in V (V = PP
x). Let P be the new Px (P = Px). The variable S is set to 1 when the sign of P is positive, S is also set to 0 when P is 0, and S is set to -1 when the sign of P is negative (S = sgn (P)). Multiply S and V to obtain Y (Y = S * V).

[102] When Y ≧ Y1 (Y1 is a negative constant including 0), go to [103], and when Y2 <Y <Y1 (Y2 is a negative constant), go to [61] of <pan end detection> 186. , Y ≦ Y
In case of 2, go to [104].

[103] Add M2 to the composite ratio D to make a new D (D
= D + M2). Here, M2 is a constant smaller than 1, for example, M2 = 0.2. That is, the composition ratio D is increased to a predetermined value M2. After that, when D is larger than D2, D is set to D2 (upper limit limiting means). Next, go to [61] of <pan end detection> 186.

[104] Subtract M2 from the composition ratio D to obtain a new D (D =
D-M2). That is, the synthesis ratio D is made smaller by the predetermined value M2. After that, when D is smaller than D1,
D is set to D1 (lower limit value limiting means). Next, go to [61] of <pan end detection> 186.

Furthermore, FIG. 13 (b) shows another flowchart example of <correction of gain> 185. In this example, the composite ratio D is increased or decreased at a ratio according to the digital value Y related to the relative angular velocity (V). This will be described.

[111] Subtract Px from P and store in V (V = P−P
x). Let P be the new Px (P = Px). The variable S is set to 1 when the sign of P is positive, S is also set to 0 when P is 0, and S is set to -1 when the sign of P is negative (S = sgn (P)). Multiply S and V to obtain Y (Y = S * V).

[112] When Y ≧ Y1 (Y1 is a negative constant including 0), go to [113], and when Y2 <Y <Y1 (Y2 is a negative constant), go to [61] of <pan end detection> 186. , Y ≦ Y
In case of 2, go to [114].

[113] The value obtained by adding Y3 to Y3 (Y3 is a positive constant) is M3.
Double (M3 is a constant), add 1 to the value, and store in Md (Md = 1 + M3 * (Y + Y3)). Multiply the composite ratio D by Md to obtain a new D (D = D * Md). That is, the composite ratio D is increased by the ratio Md corresponding to the relative angular velocity (V).
After that, when D is larger than D2, D is set to D2 (upper limit limiting means). Next, <pan end detection> 186
Go to [61].

[114] | Y | minus Y4 (Y4 is a positive constant) is multiplied by M3, 1 is added to the value, and the result is stored in Md (Md =
1 + M3 * (| Y | -Y4)). The synthesis ratio D is set to 1 / Md to obtain a new D (D = D / Md). That is, the composite ratio D is made smaller by the ratio Md corresponding to the relative angular velocity (V).
After that, when D is smaller than D1, D is set to D1 (lower limit value limiting means). Next, <pan end detection> 186
Go to [61].

Further, FIG. 13 (c) shows another flowchart example of <correction of gain> 185. In this example, the synthesis ratio D is increased or decreased by a value corresponding to the digital value Y related to the relative angular velocity (V). This will be described.

[121] Px is subtracted from P and stored in V (V = P-Px).
Let P be the new Px (P = Px). The variable S is set to 1 when the sign of P is positive, S is also set to 0 when P is 0, and S is set to -1 when the sign of P is negative (S = sgn (P)). Multiply S and V to obtain Y (Y = S * V).

[122] When Y ≧ Y1 (Y1 is a negative constant including 0), go to [123], and when Y2 <Y <Y1 (Y2 is a negative constant), go to [61] of <pan end detection> 186. , Y ≦ Y
In case of 2, go to [124].

[123] Y + Y3 (Y3 is a positive constant) + M4
Double (M4 is a constant) and store in Md (Md = M4 * (Y +
Y3)). Add Md to the composite ratio D to make a new D (D =
D + Md). That is, the composition ratio D is increased by the value Md corresponding to the relative angular velocity (V). After that, when D is larger than D2, D is set to D2 (upper limit limiting means). Next, go to [61] of <pan end detection> 186.

[124] | Y | minus Y4 (Y4 is a positive constant) is multiplied by M4 and stored in Md (Md = M4 * (| Y | -Y
4)). Subtract Md from the composition ratio D to obtain a new D (D =
D-Md). That is, the composite ratio D is made smaller by the value Md according to the relative angle (V). After that, when D is smaller than D1, D is set to D1 (lower limit value limiting means). next,
<Detection of end of pan> Go to [61] of 186.

In the above-described embodiment, the relative ratio (BD / A) between the detection gain BD of the relative angle θ _h and the detection gain A of the angular velocity ω _m is increased or decreased by changing the composition ratio D. However, the present invention is not limited to such a case. For example, the gain of the position detector 11 may be increased or decreased, or the gain of the angular velocity detector 12 may be increased or decreased, which is of course included in the present invention.

Further, in the <pan start detection> 182 of the above-described embodiment, the digital value V corresponding to the relative angle θ _h
Although the start of panning is detected when these enter the shaded area in FIG. 9, the present invention is not limited to such a case. FIG. 14A shows another flowchart example of <pan start detection> 182. In this example, the start of the panning operation is detected when the relative speed θ _h (P) is out of the predetermined range. This will be described.

[201] Set P to a new Px (Px = P).

[202] | P | <P2 (P2 is a constant) <Control operation at rest> Return to [11] of 181. If not | P | <P2, go to <31> of <gain setting> 183. .

Further, FIG. 14 (b) shows another example of the flowchart of <pan start detection> 182. In this example, the relative angle θ _h (P) is out of the predetermined range, or the combined value (W) of the relative angle (P) and the relative angular velocity (V) is out of the predetermined range. , The start of the panning operation is detected (slightly different from the panning start detection area in FIG. 9). This will be described.

[211] Subtract Px from P and store in variable V (V = PP
x). A value obtained by multiplying P by H1 (H1 is a constant) and a value obtained by multiplying V by H2 (H2 is a constant) are added and stored in a variable W (W = H1 * P + H2 * V). Make P a new Px (Px
= P).

If [212] | P |> P2 (P2 is a constant), the operation proceeds to [31] of <gain setting> 183, and if not | P |> P2, the operation proceeds to [213].

[213] | W |> W1 (W1 is a constant) <Go to gain setting> Go to [31] of 183. If not | W |> W1, <Control operation at rest> Go to [11] of 181. Go home.

Further, in the <pan end detection> 186 of the above-described embodiment, the digital value Q corresponding to the angular velocity ω _m and the relative angle θ _h.
Although the end of panning is detected by reducing the absolute values of the digital value P corresponding to the above and the digital value V corresponding to the relative angular velocity, the present invention is not limited to such a case. FIG. 15A shows another example of the flowchart of <pan end detection> 186. In this example, the end of the panning operation is detected when the angular velocity ω _m (Q) of the lens barrel portion 1 as viewed from the inertial coordinate is within a predetermined range. This will be described.

[301] | Q | <Q1 (Q1 is a constant) <Control operation at rest> Return to [11] of 181, and if not | Q | <Q1, <Control operation during panning> [41] of 184 Return to.

Further, FIG. 15 (b) shows another example of the flow chart of <pan end detection) 186. In this example, the end of the panning operation is detected when the angular velocity ω _m (Q) is within the predetermined range and the relative angle θ _h (P) is within the predetermined range. This will be described.

[311] If | Q | <Q1 (Q1 is a constant), go to [312]. If not | Q | <Q1, return to [41] of <control operation during panning> 184.

[312] If | P | <P4 (P4 is a constant), return to [11] of <control operation at rest> 181. If not | P | <P4, <control operation at panning> [41] of 184. Return to.

As shown in each of the above-described embodiments, the image pickup apparatus of the present invention does not require an air chamber and can be made compact and lightweight.
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. In addition,
The detection of the magnetic field of the magnet is not limited to the Hall element, but a magnetoresistive element or a supersaturated reactor may be used. Further, the pan movement detecting means and the gain correcting means can be simply configured, and the collision between the lens barrel portion and the support body during the panning operation can be prevented. Of course, the application range of the photographing apparatus is not limited to the video camera. Besides, various modifications can be made without changing the gist of the present invention.

Advantageous Effects of Invention According to the photographing apparatus of the present invention, by detecting the relative position of the lens barrel and the support and the angular velocity of the lens barrel, the lens barrel is driven and controlled by the actuator means so as to suppress the fluctuation of both. However, the vibration of the lens barrel is greatly reduced. Furthermore, a panning motion detection means and a gain correction means are provided,
The collision between the lens barrel and the support is also prevented. Therefore, if, for example, a video camera is constructed based on the present invention, 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 an image pickup apparatus according to an embodiment of the present invention, FIGS. 2 (a), (b), and (c) are diagrams showing a concrete structure of the actuator of FIG. 1, and FIG. FIG. 1 is a diagram showing a specific configuration of the position detector, FIG. 4 is a diagram showing a specific configuration of the angular velocity detector of FIG. 1, and FIG. 5 is a specific configuration of an A / D converter. FIG. 6 is a diagram showing a concrete configuration of the driver of FIG. 1, FIG. 7 is a diagram showing a basic flowchart of a program built in the synthesizer, and FIGS. 8 (a) to 8 (f). FIG. 9 is a diagram showing a detailed flowchart of each part, FIG. 9 is a diagram showing a panning start detection area, FIG. 10 is a block diagram of a vibration isolation mechanism, and FIG. 11 is a frequency transfer function G from θ _x to θ _m .
(Jω), FIG. 12 is a view showing how θ _x changes, and FIGS. 13 (a) to 13 (c) are views showing another flow chart of <gain correction> 185, FIG. (a), (b) is a diagram showing another flowchart of <pan start detection> 182,
15 (a) and 15 (b) are diagrams showing another flowchart of <pan end detection> 186, and FIG. 16 is a configuration diagram showing an example of a conventional image stabilizing mechanism. 1 ... Lens barrel part, 2 ... Main body case (support), 3 ... Actuator, 4 ... Rotation axis, 5 ... Hall element (sensing element), 6 ... Angular velocity sensor, 7 ... Fixing member , 11 ...
... Position detector, 12 ... Angular velocity detector, 13 ... Combiner, 14 ... Driver, 21, 22 ... A / D converter, 2
3 ... arithmetic unit, 24 ... memory, 25 ... D / A converter, 41 ... image sensor, 42 ... image signal processor, G ...
The center of gravity of the lens barrel section 1.

Claims (3)

[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, Position detecting means for detecting a relative angle between the lens barrel and the support, angular velocity detecting means for detecting an inertial angular velocity of the lens barrel around the rotation axis, an output signal of the position detecting means and the angular velocity detecting means. Of the output signal of the position detecting means, the driving means for supplying electric power to the actuator means so as to suppress the fluctuation of the combined signal output by the combining means, and the output signal of the position detecting means. outside Of the panning operation detecting means for detecting the start of the panning operation, and detecting the end of the panning operation when the output signal of the angular velocity detecting means is within the second predetermined range. The relative ratio of the detection gain of the position detecting means and the detection gain of the angular velocity detecting means is changed by the output signal, and the gain of the position detecting means is relatively increased as compared with the gain of the angular velocity detecting means. An image pickup apparatus comprising a gain correction means. 2. The gain correction means increases or decreases the relative ratio of the detection gain of the position detection means and the detection gain of the angular velocity detection means by a predetermined ratio every predetermined time. The imaging device according to item (1). 3. The gain correction means increases or decreases the relative ratio of the detection gain of the position detection means and the detection gain of the angular velocity detection means by a predetermined value at predetermined time intervals. The imaging device according to item (1).