JPS63254870A - Photographing device - Google Patents

Abstract

PURPOSE:To realize the vibrationproofing function without enlarging the whole of a device by using an inertia angle detecting means to support freely rotatably a coil to interlink with the magnetic flux of a magnetic circuit formed by a magnet and a yoke. CONSTITUTION:A coil 203 to interlink with a magnetic circuit formed by a magnet 201 and a yoke 202 of an inertia speed detecting element 107 is freely rotatably supported through a shaft 205 and a bearing 206, and feeding is executed through a terminal 208 and a helical spring 207. When the angle speed of the magnet 201 and the yoke 202 around a coil supporting shaft is omegam and the angle speed of the coil 203 is omegas, an electromotive force to occur at the coil 203 is in proportion to omegam-omegas, and therefore, the electromotive force is detected by an inertia angle detecting device 108 and thus, a voltage (a) in proportion to the angle speed omegam is obtained. A relative angle detecting device 110 processes the output signal of a relative angle detecting element 109 to detect the relative angle of a lens-barrel 101 and a supporting body 104 and outputs a relative signal (b). The signals (a) and (b) are synthesized 111 and a power is supplied from a driving circuit 112 to an actuator 106.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a photographing device such as a video camera that is used in combination with a recording device such as a video tape recorder, and in particular to a photographing device such as a video camera that is used in combination with a recording device such as a video tape recorder. The present invention relates to a photographing device having an anti-vibration function that can be obtained.

2. Description of the Related Art In recent years, the performance of video equipment has improved dramatically, and it has become extremely easy to obtain high-quality images. Along with this, advanced photographic techniques are also required. As one of these, there is a desire to obtain stable images even when photographing from places where conventionally stable images could not be obtained due to the shaking of the photographing device, such as from a moving automobile or an airplane. For this purpose, a photographing device has been proposed that has an anti-vibration function that allows stable images to be obtained regardless of the shaking of the photographer and the photographing device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A conventional photographing device having an image stabilization function will be described below with reference to the drawings. FIG. 14 is a configuration diagram of a conventional photographing device having an image stabilization function.

Reference numeral 901 is an imaging unit including a lens unit and an image sensor.

902 is a counterweight for the most imaged portion 901, and is mechanically coupled to the imaging portion 901 by a connecting rod 903. A joint 905 rotatably connects the connecting rod 903 and the support rod 904. The photographer operates this photographing device by supporting the support rod 904. In the above configuration, the imaging unit 901. The counterweight 902 is adjusted so that the center of gravity G of the movable portion 906 composed of the connecting rod 903° and the counterweight 902 is located near the joint 905.

Then, the movable part 906 will have a large moment of inertia around the joint 905. Therefore, even if the support body 904 supported by the photographer suddenly tilts due to some reason, the posture of the movable part 906, that is, the imaging unit 901, is kept constant without tilting due to the action of the moment of inertia of the movable part 906. . That is, a stable image can be obtained even when photographing in a place where the photographer himself/herself moves as described above. For example, John Jurgens; Steadicam Design; SMPTE Journal, Volume 87, September 1978, Page 587 (John
Jurgens rsteadicam as a
Design Prob-lem J, SMPT
E journal Vol, 87. Sep, 197
B, P587) etc. are prior art.

Problems to be Solved by the Invention However, in order to obtain sufficient performance in this conventional example, a large moment of inertia is required, and as a result, the overall size of the device has to be increased. As a result, since it requires skill to operate, it has not become popular among general users despite having the above-mentioned features.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a photographing device that is compact, easy to operate, and has anti-vibration characteristics.

Means for Solving the Problems In order to achieve the above object, a first shadow device of the present invention has the following features:
A lens unit that optically forms an image of light from a subject, an image sensor that converts the optical image obtained by the lens unit into electrical information, and a mirror that mechanically couples the lens unit and the image sensor to form an optical axis. A barrel portion, a support body that rotatably supports the lens barrel portion about a predetermined rotation axis, an actuator means that generates a rotational force between the lens barrel portion and the support body, and a rotational force of the lens barrel portion. An inertial angular velocity detection means that detects the inertial angular velocity around the moving axis, a relative angle detection means that detects the relative positional relationship between the lens barrel and the support, and a combination that combines the output signals of the inertial angular velocity detection means and the relative angle detection means. and drive means for supplying power to the actuator means in response to the combined signal of the combining means.

Function: With the above-described configuration, the present invention can reduce the size of the entire photographing device by replacing the physical moment of inertia with an electric servo mechanism. Furthermore, the inertial angular velocity detecting means for detecting the inertial angular velocity is a simple mechanism, and the photographing apparatus having the above-mentioned image stabilization function can be realized at a low cost.

Embodiment Hereinafter, an embodiment of the photographing apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the lens barrel section is indicated by 101, and the lens barrel section 101 is composed of a lens section 102 for converging light from an object, and an image sensor 103 for converting an optical image into an electrical signal. Ru. 104 is a support body that supports the lens barrel portion 101 so as to be rotatable around the rotation axis 105;
The photographing device is operated via this support 104. Reference numeral 106 indicates a rotation shaft 1 between the lens barrel portion 101 and the support body 104.
This is an actuator that generates rotational force around 05.

107 is an inertial angular velocity detection element attached to the lens barrel section 101 and detects the inertial angular velocity of the lens barrel section 101;
8 is an inertial angular velocity detector that processes the output signal of the inertial angular velocity detection element 107 and outputs an inertial angular velocity signal. 10
9 is a relative angle detection element that detects the relative angle between the lens barrel section 101 and the support body 104; 110 is a relative angle detection element 1;
This is a relative angle detector that processes the output signal of No. 09 and outputs a relative angle signal. 111 is a synthesizer that synthesizes the output signal of the inertial angular velocity detector 108 and the output signal of the relative angle detector 110. Reference numeral 112 denotes a drive circuit 112 that supplies power to the actuator 106 in accordance with the signal synthesized by the synthesizer 111.

Next, the operation of each component will be explained. The inertial angular velocity detection means includes an inertial angular velocity detection element 107 and an inertial angular velocity detector 108. The inertial angular velocity detection element 107 is shown in FIG. A magnet 201 is magnetized in the horizontal direction in the drawing. The magnetic flux generated by the magnet 201 is guided to a magnetic circuit formed by the yoke 202. The yoke 202 in the center is a non-magnetic member 209
Fixed by Coil 203 connects shaft 205 and bearing 2
06, it is supported rotatably around an axis in the vertical direction in the drawing in FIG. 2. Both ends of the coil 2070 are connected to a terminal 208 by a power supply means using a conductive helical spring 207. A weight 204 is coupled to the coil 203 to increase the moment of inertia. The configuration of the magnetic circuit, the method of supporting the coil 203, etc. is similar to that of a moving coil ammeter, but the major difference is that the weight 204 is connected to the coil 203. In a normal ammeter, the response speed is improved. In contrast, the inertial angular velocity detection element of the present invention is constructed to increase the moment of inertia of the movable part. Note that the coil 203. The movable part including the weight 204 is made of non-magnetic material so as not to generate cogging torque. FIG. 3 shows the configuration of the inertial angular velocity detector 108. The inertial angular velocity detector 10B includes a terminating resistor 210 for terminating the coil 203, an amplifier 211 for amplifying the voltage generated at the terminating resistor 210, and an amplifier 211 for amplifying the voltage generated at the terminating resistor 210. It is composed of feedback resistors 212 and 213 for determining the gain of. The resistance of the terminating resistor 210 is adjusted to maintain the coil 203 in critical braking by terminating the coil 203 as it moves in the magnetic field.

Here, the magnet 201. around the coil support axis is based on the inertial coordinates. When the angular velocity of the yoke 202 is ω1 and the angular velocity of the coil 203 is ω, a block diagram showing these relationships is shown in FIG. 4. In the diagram, S indicates a complex number of Laplace transform.

The torque transmitted to the coil 203 is the torque transmitted via the helical spring 207 and the torque due to viscous resistance generated when the coil 203 is braked. The former is proportional to the relative angle between the coil 203 and the yoke 202, and the latter is proportional to the relative angular velocity between the coil 203 and the yoke 202. In the figure, block 214 represents an integral element and represents the angular velocity ω. is the angle θ
Converted to 1. At addition point 219, angle θ of yoke 202
, and the angle θ of the coil 203, the relative angle can be obtained.

Block 215 represents a helical spring 215, and the relative angle is multiplied by a spring constant Kx and converted into torque.

On the other hand, the angular velocity ω. is subtracted from the angular velocity ω of the coil at an addition point 220 to obtain a relative angular velocity, and multiplied by the viscous resistance constant Kw by the viscous resistance shown in block 216 and converted to torque. Two torques greater than or equal to 0 are added at an addition point 221. , is applied to a movable part consisting of a coil 203 represented by a block 217 and a weight 204 coupled thereto. If the moment of inertia around the axis of the coil 203 and the weight 204 coupled thereto is J3, the torque is converted to an angular velocity ω5 by multiplying by (Js −31. Blocks 2, 18
represents an integral element like block 214, and the angular velocity ω3
According to the block diagram of 0 or more that converts into angle θ5,
Angular velocity ω. The transfer function from to angular velocity ω3 is Kw K.

□・S+ − JS JS ・・・・・・ Represented by il+. Similarly, the angular velocity ω. relative angular velocity ω1−ω
The transfer function to , is expressed as JS JS (2). FIG. 5 shows the frequency characteristics of the transfer functions expressed by equations (1) and (2). Relative angular velocity ω. −
C3 is the angular velocity ω at a resonance frequency of 10 or more determined by the spring constant of the helical spring and the moment of inertia Js. and one on one
It turns out that this corresponds to Now, since the electromotive force generated in the coil 203 is proportional to the relative angular velocity ω1-ω3, by detecting this electromotive force, the magnet 201 and the yoke 203 are
The angular velocity ω of can be detected. Therefore, the output of the inertial angular velocity detector 108 provides a voltage a proportional to the angular velocity ω□.

Note that the resonance frequency f. and the spring constant, and the moment of inertia J
There is the following relationship between .

Therefore, the moment of inertia Js is large and the spring constant K
The smaller X is, the lower the angular velocity ω.

can be detected. This is why the weight 204 is added.

The relative angle detection means includes a relative angle detection element 109 and a relative angle detector 110. The relative angle detecting element 109, which shows the connection of the relative angle detecting means in FIG. 6, is a Hall element and is attached to the support 104. As shown in FIG. 7, a magnet 11B is arranged on the side of the lens barrel section 101 facing the relative angle detection element 109. The magnet 118 is magnetized so as to generate a magnetic field on the relative angle detection element 109 according to the relative angle between the support body 104 and the lens barrel section 101 (FIG. 8). Then, due to the action of this magnet 118, the output end XX of the relative angle detection element 109.

A voltage proportional to the product of the current flowing from the input terminal Y to Y' and the strength of the magnetic field applied to the relative angle detection element 109 is generated. In FIG. 6, relative angle detection element 109
The current flowing from the input terminal Y to Y' is the current limiting resistor 301.
, 302, the output 6iXX
The voltage generated at ' is proportional to the strength of the magnetic field. That is, by detecting the voltage generated at the output end xx', the relative angle between the lens barrel section 101 and the support body 104 can be detected. The relative angle detector 110 is a differential amplifier consisting of an operational amplifier 303 and resistors 304, 305, 306, and 307, and differentially amplifies the output of the relative angle detection element 109 by a predetermined factor to obtain an output signal. .

FIG. 9 shows the specific configuration of the synthesis means,
This is a summing amplifier including resistors 401, 402, 403 and an operational amplifier 404. The output signal a of the inertial angular velocity detector 108 and the output signal S of the relative angle detector +10 are added at a predetermined ratio to form the output signal C of the synthesizer 111.

FIG. 10 shows a specific configuration of the driving means, in which the driving circuit 112 includes an operational amplifier 501 and a driving transistor 5.
02.503 and a current detection resistor 504. The output signal C of the combiner 111 is applied to the non-inverting input terminal of the operational amplifier 501.

The operational amplifier 501 operates to equalize the potential of the non-inverting input terminal and the potential of the inverting input terminal, that is, the voltage generated in the current detection resistor 504 by the current flowing through the coil 601 of the actuator 106. Therefore, a current proportional to the output signal C of the synthesizer 111 flows through the coil 601 of the actuator 106.

FIG. 11 shows a specific configuration of the actuator means, including a magnet 602 and a coil 601fa+.

601 (BL and back yoke 60 made of ferromagnetic material
3Fa1. 603 Q)l is arranged around the rotation axis 105. The magnet 602 is attached to the back yoke 603 (a
It is connected to the lens barrel section 101 via the lens barrel 101, and is magnetized as shown in Figure 11. On the other hand, coil (iol(al).

601 (bl is connected to the support 104 via the bank yoke 603 (bl), and coils 60 Hat, 601 +b+ are arranged as shown in FIG. flows, the magnet 602 and the coil 60 Mal,
An electromagnetic force is generated between 601 fbl, and under the configuration shown in FIG. 11, a torque is generated around the rotating shaft 105 in accordance with the magnitude of the current.

Next, the anti-vibration function of the ink shadowing device of the present invention will be explained.

The angle θ around the rotation axis 105 of the lens barrel section 101 as seen from the inertial coordinates. , the angular velocity of inertia is ω. , Similarly, the angle of the support body 104 seen from the inertial coordinates is θ.

In this case, the control block diagram of the image stabilization function of the photographing apparatus having the configuration shown in FIG. 1 is as shown in FIG. 12. Relative angle θ between lens barrel portion 101 and support body 104. −〇 means relative angle detection element 1
Detected by 09. The relative angle detection element 109 and the relative angle detector 110 are represented by block 701 in FIG. 12, and the relative angle θ0-θ. Obtains 8 times the signal. Inertial angular velocity ω of the lens barrel portion 101. is the inertial angular velocity detection element 107
is detected by the inertial angular velocity detector 10B. The inertial angular velocity detection element 107 and the inertial angular velocity detector 10B are represented by a block 705, and the inertial angular velocity ω of the lens barrel portion 101,
(It is assumed that the resonant frequency f0 is sufficiently low.) Signals a and b are combined by addition 1 at an addition point 707 (synthesizer 111) to obtain signal C.

Drive circuit 112 and actuator 106 are in block 70
A torque Ta expressed by 2 and proportional to the magnitude of the output signal C of the synthesizer 111 is generated between the lens barrel section 101 and the support body 105. Here, gIll is the voltage of the drive circuit 112 -
The current conversion gain, kt, is the torque constant of the actuator 106. Block 703 calculates the angular velocity ω from the torque Ta due to the mechanical moment of inertia Jm of the lens barrel portion 101. Block 704 represents the transmission to ω, and θ. , where S means a complex number in Laplace transform.

Now, if m IIl is the angle θ of the support 104. From the lens barrel section 101
angle θ. The transfer function to is θ. (at S2 +F-s+D...
(3) Here, ω1-2π・fl knee ...... (4)
ω = 2π・f2−F (5)
When you put it down, ω becomes smaller〈ω2... (6)
Therefore, the line-return Bode diagram of the frequency transfer function G(jω) is as shown in FIG.

That is, the angle θ of the support body 104 as seen from the inertial coordinates. The transfer characteristic G(jω) of the angle θ of the lens barrel portion 101 with respect to the first corner frequency f is 1 in the frequency range below.
(OdB) (line ■), and in the frequency range of 11 or more and below the second corner frequency f2, it is attenuated by -6 dB10ct (line ■), and in the frequency range of 12 or more -12 dB1
From FIG. 13, θ is attenuated at 0 Ct (line ■) in the frequency range of 11 or more. The amount of transmission from the vibration of to the vibration of θ becomes smaller. Its degree is expressed by the difference Z between QdB (line ■) and the characteristic line.

Effects of the Invention As described above, the imaging device provided by the present invention includes a magnet that generates a magnetic field, a yoke that forms a magnetic circuit with an air gap together with the magnet, and a yoke that links the air gap in the magnetic circuit with magnetic flux. By using inertial angular velocity detection means consisting of arranged coils, support means for supporting the coils so as to be rotatable around a predetermined rotational axis, and power supply means for supplying power from the coils, the overall size of the device can be increased. It is possible to realize the anti-vibration function without any vibration.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the photographing device of the present invention;
Fig. 2 is a cross-sectional view of the inertial angular velocity detection element, Fig. 3 is a circuit diagram of the inertial angular velocity detector, Fig. 4 is a block diagram of the inertial angular velocity detection element, and Fig. 5 is a Bode diagram of the inertial angular velocity detection element.
Figure 6 is a circuit diagram of a relative angle detection element and a relative angle detector.
Fig. 7 is a layout diagram of the relative angle detection element, Fig. 8 is a magnetization characteristic diagram of the magnet placed opposite the relative angle detection element, and Fig. 9
Figure 10 is a circuit diagram of the synthesizer, Figure 10 is a circuit diagram of the drive circuit and actuator, Figure 11 is a configuration diagram of the actuator, Figure 12 is a block diagram of the photographing device of the present invention, Figure 13 is the same as Figure 7. Angle θ of the support in the block diagram. FIG. 14 is a boat diagram showing the transfer characteristics from the angle .theta. of the lens barrel to the angle .theta. of the lens barrel. +01... Lens barrel section, 102... Lens section, 103... Imaging element, 104...
Support body, 105...Rotation axis, 106...
・Actuator, 107... Inertial angular velocity detection element, 108... Inertial angular velocity detector, 109.
... Relative angle detection element, 110 ... Relative angle detector, 21 ... Synthesizer, 112 ...
...Drive circuit. Name of agent: Patent attorney Toshio Nakao 1 person lθ5-
Fig. 2 Fig. 3 Fig. 4 Fig. 5 Circular reduction (logarithm W moxibustion) Fig. 6 Fig. 7 ηa 脣 71 east Fig. 9 Chopsticks 10 Fig. 11 Fig. 6 θ? Figure 12 70.5 Figure 13 Circumference 5 inverse number (ri↑numerical position IE)

Claims (1)

[Claims] A lens section that optically forms an image of light from a subject, an image sensor that converts the optical image obtained by the lens section into electrical information, and a mechanically coupled optical axis between the lens section and the image sensor. a lens barrel portion to be formed; a support body that supports the lens barrel portion rotatably about a predetermined rotation axis; and an actuator means that generates a rotational force between the lens barrel portion and the support body. , an inertial angular velocity detecting means for detecting an inertial angular velocity of the lens barrel about the rotation axis, a relative angle detecting means for detecting a relative positional relationship between the lens barrel and the support, and an inertial angular velocity detecting means. A photographing device comprising a combining means for combining output signals of the relative angle detecting means, and a driving means for supplying electric power to the actuator means according to the combined signal of the combining means, wherein the inertial angular velocity detecting means is connected to a magnetic field. a yoke that forms a magnetic circuit with an air gap together with the magnet, a coil arranged to interlink with magnetic flux in the air gap in the magnetic circuit, and the coil rotated around a predetermined rotation axis. 1. A photographing device comprising: support means for movably supporting; and power supply means for supplying power from the coil.