JP2000221421A - Optical control element and image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical control element preventing influence by an electrified substance in the vicinity of a mirror by using a driving system for rotating a mirror by using a tube whose shape is controlled by air pressure as an actuator and utilizing expansion by pressuring. SOLUTION: Figure (a) shows that the air pressure in a cavity A46 and a cavity B47 is in an initial state and a condition that the reflection surface of the mirror 4 is neutral. By feeding air to the cavity A46 from an air pressure adjusting device and increasing the air pressure in the cavity A46 to specified one, the deformed tube A44 rotates a base 41 supported through a pivot A42 in a state where the reflection surface of the mirror 4 is kept plane as shown by figure (b). As for air flowing in and discharged from an air entrance; the pressure in the tube A44 becomes the same by an air distribution pipe, so that the rotational angle of the mirror 4 becomes the same. Since the tube controlled by the air pressure is used to rotate the mirror 4, the influence by the electrified substance in the vicinity of the mirror in the rotation control of the mirror 4 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light control element having a function as a spatial light modulator useful in fields such as an image pickup device and a video camera mounted on a moving body such as a vehicle, a ship, an aircraft, and the like, and its light. The present invention relates to an imaging device using a control element.

[0002]

2. Description of the Related Art FIG. 7 is a diagram showing a configuration example of a conventional light control element disclosed in Japanese Patent Application Laid-Open No. 3-40693. In FIG. 7A, reference numeral 1 denotes a mirror device, reference numeral 2 denotes a surface, and reference numeral 3 denotes a plurality of light control elements arranged in a matrix and arranged in a plane. In FIG. 7B showing details of the light control element 3, reference numeral 4 denotes a mirror having a reflecting surface for incident light, reference numerals 5 and 6 denote torsional hinges for supporting the mirror 4, and reference numeral 7 denotes torsional hinges 5 and 6.
Is a fixed beam.

FIG. 8 is a diagram showing the operation of the light control element. The mirror 4 moves the torsion hinges 5 and 6 from the position indicated by the broken line 12 to the position indicated by the broken line 13 with respect to the vertical plane 11.
Can be moved around an axis 14 which indicates the rotation center of. In the “on” position, the edge 15 of the mirror 4 contacts the landing electrode 16. The mirror 4 is moved to the "on" position by applying a suitable positive voltage to the control electrode 17. The voltage on the control electrode 17 is the positive electrode 1
8 and via a NOT circuit 19
Added to 0. A differential bias is applied to mirror 4 via electrode 21.

In the "off" state, the mirror 4 applies a negative voltage to the control electrode 17 and rotates to the position shown by the broken line 13.

The mirror device 1 has a plurality of light control elements 3 arranged in a matrix and arranged in a plane, and the rotation of each mirror can be controlled individually or simultaneously.

On the other hand, FIG. 9 is a diagram showing an example of the configuration of a light control element disclosed in Japanese Patent Application Laid-Open No. 6-175050, in which the distortion of the mirror during rotation is suppressed. In FIG. 9 showing the configuration of the light control element 3, reference numerals 4 and 7 are the same as those in the conventional example of FIG. Reference numerals 22 and 23 denote flexible pivots having low torsional rigidity, which are composed of two thin plates which support the mirror 4 and are joined perpendicularly to each other.

The light control element shown in FIG. 9 can control the rotation of the mirror 4 by the same driving method as the conventional example shown in FIG. Further, in this example, even when the mirror 4 rotates, the mirror 4 does not distort because the flexible pivots 22 and 23 as the supporting members have low torsional rigidity.

Next, FIG. 10 shows a configuration example of a conventional image pickup apparatus using a movable mirror and a motor for rotating the mirror without providing the light control element. In the figure, 31 is an image sensor, 32 is an image pickup unit incorporating the image sensor 31, 33 is a frame which is a housing to which the image pickup unit 32 is fixed, 34 is a gyro fixed to the frame 33, and 35 is supported by the frame 33 The bearing 36 is a movable mirror supported by the bearing 35 so as to be rotatable about one axis perpendicular to the visual axis of the imaging unit 32, and 37 is a frame 3
3, a motor for driving the movable mirror 36; 38, an electronic control unit for controlling the motor 37 based on a signal from the gyro 34; 39, an angle sensor for detecting the angle of the movable mirror 36 with respect to the frame 33; 33 is a fixed mirror fixed to 33.

FIG. 11 is a block diagram showing the operation of the imaging apparatus. The movement of the frame 33 is detected by the gyro 34, and the motor 37 is controlled by the electronic control unit 38 based on the gyro signal so that the movement of the movable mirror 36 in the space becomes zero, and the movable mirror 36 is driven. The pointing error of the movable mirror 36 with respect to the command value of the electronic control device 38 is detected based on the difference between the integrated value of the gyro 34 and the measurement value of the angle sensor 39, and is fed back by the electronic control device 38, thereby accommodating the fluctuation of the entire imaging device. Image blur can be prevented.

[0010]

In the conventional light control device shown in FIGS. 7 and 9, a charged mirror is rotated by an electric attraction force. However, if there is a charged material near the mirror, the rotation angle of the mirror is increased. And the voltage changes. For example, there is a case where an ungrounded housing is charged by static electricity. Therefore, for the purpose of simplifying the structure, for example, FIG.
Instead of using a movable mirror 36, a rotation angle detector such as a motor 37 or an angle sensor 39, the light control element 1 is provided at the position of the movable mirror 36, and a target is set based on a predetermined relationship between the applied voltage and the mirror rotation angle. In the case where an image pickup device that performs open control of the mirror rotation angle by applying a voltage corresponding to the rotation angle is obtained, there is a problem that the angle accuracy is remarkably deteriorated and cannot be controlled.

Further, in the conventional light control element, since the pivot for supporting the mirror is outside the mirror, there is a problem that the aperture ratio becomes low.

Further, in the conventional image pickup apparatus shown in FIG. 10 which does not use a light control element, the mechanism for spatially stabilizing an image is only one of a motor drive type, which hinders improvement in spatial stabilization accuracy. The level required for performing image tracking processing in an imaging device or the like mounted on a moving object, or a level that cannot be visually recognized by a video camera or the like (that is, 1/2 of the imaging element). There has been a problem that the image shake due to the shaking of the imaging device cannot be suppressed to a level where it is not possible to judge from the image that the image shake remains by suppressing the image shake below the pixel.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a drive system for rotating a mirror using expansion by pressurization using a tube whose shape is controlled by air pressure as an actuator. By using this, it is possible to obtain a light control element which is not affected by a charged material near the mirror, and to provide a light having an increased aperture ratio by providing a pivot for supporting the mirror not on the outside of the mirror but on the side opposite to the reflection surface. It is another object of the present invention to obtain an image pickup device in which the control element is further used to reduce the influence of friction torque on a movable mirror by using the light control element, thereby improving the directivity.

[0014]

According to a first aspect of the present invention, there is provided a light control device comprising: a mirror having a reflecting surface for incident light; a base for holding the mirror in a plane; and a mirror for rotating the mirror about one axis. A flexible pivot joined to a base, and a mirror that is provided with an airtight cavity and an air inlet / outlet to the cavity while supporting the base apart from the pivot and according to a change in air pressure in the cavity. , A beam that fixes the tube, and a pressure adjusting device that adjusts the air pressure in the cavity so as to move the base and rotate the mirror.

According to a second aspect of the present invention, there is provided a light control device, comprising: a mirror having a reflecting surface for incident light; a base for holding the mirror in a plane; and a mirror joined to the base so that the mirror can be rotated about one axis. A pivot having flexibility;
While supporting the base apart from the pivot, a watertight cavity and a liquid inlet / outlet to the cavity are provided, and a tube deformable in the direction of the mirror in response to a change in the liquid pressure in the cavity; The apparatus comprises a filled liquid, a beam for fixing the tube, and a pressure adjusting device for adjusting the pressure of the liquid in the cavity so as to move the base and rotate the mirror.

According to a third aspect of the present invention, there is provided an imaging apparatus for converting incident light into an electric signal by using a built-in imaging element, a housing to which the imaging unit is fixed, and a housing fixed to the housing. A gyro for detecting shaking of the housing, a bearing fixed to the housing, a movable mirror supported by the bearing in a state rotatable with respect to one axis perpendicular to the visual axis of the imaging unit, A motor supported by the housing for driving the movable mirror, a first electronic control device for controlling the motor to cancel the shaking of the movable mirror with respect to the space based on a signal from the gyro, and the housing 2. The light control device according to claim 1, wherein the angle sensor is fixed to the housing and detects an angle of the movable mirror with respect to the housing, and the light control element is fixed to the housing at a position where incident light from the movable mirror is reflected to the imaging unit. Multiple A mirror unit formed by arranging in a plane,
Controlling the light control element based on a difference between an integrated value of the gyro signal and a measured value of the angle sensor so that a pointing error of the movable mirror with respect to a command value of the first electronic control device is canceled. And an electronic control unit.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of a light control element according to a first embodiment of the present invention. In the figure, 1, 2, 4, and 7 are the same as those of the conventional device. Reference numeral 51 denotes an air inlet / outlet through which air flows in and out of an air adjusting device (not shown), and 52 denotes an air distribution pipe for distributing the air flowing in from the air inlet / outlet 51. In FIG. 1B showing details of the light control element 3b, reference numeral 41 denotes a base for holding the mirror 4 in a plane, reference numeral 42 denotes a thin film pivot A for rotatably supporting the base 41, and reference numeral 43 denotes a pivot A4 for the base 41.
2 is a pivot B in the form of a thin film supported together with the pivot 2. The mirror 4 is held by the base 41 by, for example, vapor deposition of aluminum or bonding of an aluminum thin film, and rotates together with the base 41. The base 41 is formed, for example, by providing a concave portion on a silicon substrate. One end of the pivot A42 is joined to the opposite surface of the base 41 to which the mirror 4 is joined,
For example, silicon is used as a material. The pivot B43 has one end joined to the base 41 on a surface of the base 41 facing the joint surface of the mirror 4, and is made of, for example, silicon.

FIG. 2 is a sectional view of FIG. 1 (b), wherein reference numeral 44 denotes a tube A to which the other end of the pivot A42 is joined and which is supported and fixed to the beam 7, and 45 denotes a tube to which the other end of the pivot B43 is joined. The tubes B and 46 supported and fixed to the beam 7 are controlled in air pressure by an air pressure adjusting device such as a pump (not shown), and air for deforming the tube A44 is filled from an air hole (not shown) to be an airtight tube. A
The cavities A and 47 provided in 44 are cavities B provided in an airtight tube B45 in which air pressure is controlled by an air pressure adjusting device (not shown) and air for deforming the tube B45 is filled from an air hole (not shown) and airtight. is there. By providing the pivot for supporting the mirror on the side opposite to the reflection surface, the aperture ratio can be increased.

FIG. 3 is a diagram showing the operation of the light control element according to this embodiment. FIG. 3A shows a cavity A46 and a cavity B.
This shows a state in which the air pressure in 47 is in an initial state and the reflection surface of the mirror 4 is in a neutral state. As shown in FIG. 3 (b), air is sent from the air pressure adjusting device
46 is increased to a predetermined air pressure, so that the deformed tube A44 is connected to the base 4 supported via the pivot A42.
1 is rotated while the reflecting surface of the mirror 4 is kept flat. The air flowing into and out of the air inlet / outlet 51 has the same pressure in each tube A44 by the air distribution pipe 52, so that the rotation angle of each mirror 4 is the same. FIG.
As shown in (c), the air pressure in the cavity A46 is released by the air pressure adjusting device, and the air pressure in the cavity A46 is returned to the initial pressure.
The air is sent from the air pressure adjusting device to the cavity B47 to increase the cavity B47 to a required air pressure, and the base 41 supported by the deformed tube B45 via the pivot B43 is held in a plane with the reflection surface of the mirror 4. 3
It rotates in the opposite direction to (a). Further, by returning the air pressure in the cavities A46 and B47 to the initial state again,
The reflection surface of the mirror 4 returns to the state shown in FIG. In this embodiment, since a tube controlled by air pressure is used to rotate the mirror 4, the rotation control of the mirror 4 is not affected by a charged material near the mirror.
Therefore, without using a rotation angle detector to simplify the structure of the light control element, the predetermined relationship of the mirror rotation angle according to the air pressure of the cavity in the tube, that is, the amount of deformation of the tube is determined by the air pressure, By adjusting the air pressure based on the relationship between the air pressure as a control factor and the rotation angle maintained by the deformation, the rotation angle of the mirror can be open-controlled. In the above description, the air pressure adjusting device is used as the pressure adjusting device. However, in addition to this, for example, a pressure adjusting device that fills each of the cavities A46 and B47 with liquid and adjusts the pressure of the liquid may be provided. It operates similarly and has the same effect.

Embodiment 2 FIG. 4 is a configuration diagram of an imaging apparatus according to Embodiment 2 of the present invention.
39 are the same as those of the above-mentioned conventional device. Reference numeral 60 denotes a mirror device in which a plurality of the light control elements described in Embodiment 1 are arranged in a matrix and arranged in a plane, and is fixed to a frame 33 serving as a housing. 61 is fixed to the frame 33. The second electronic control unit controls the mirror device 60.

FIG. 5 is a diagram showing the operation of the image pickup apparatus according to this embodiment. Gyro 3 for shaking of frame 33
4 and the movable mirror 3 is detected based on the gyro signal.
The motor 37 is controlled by the first electronic control unit 38 to drive the movable mirror 36 so that the fluctuation of the space 6 becomes zero. The pointing error of the movable mirror 36 with respect to the command value of the first electronic control device 38 is detected by the difference between the integrated value of the gyro 34 and the measurement value of the angle sensor 39, and the above-described conventional method is used until the feedback to the first electronic control device 38. Same as the device. Further, in this embodiment, the movable mirror 36
Is input to the second electronic control unit 61, and the second electronic control unit 61 is configured by the light control element 3 described in the first embodiment so that the fluctuation of the image with respect to the space becomes zero. The mirror device 60 is controlled by rotating the mirror 4, which is a component of the light control element 3, as shown in FIG. That is, the one-dimensional image shake accompanying the shaking of the entire imaging apparatus is set as the first stage, and the motor-driven movable mirror 3 is used.
6, there is an action of suppressing the light by the mirror 4 of the light control element 3 as the second stage. The integrated value of the gyro 34 and the angle sensor 3
9, the first electronic control unit 3 detected by the difference between the measured values
A similar effect can be obtained without feeding back the pointing error of the movable mirror 36 to the command value of 8 to the first electronic control unit 38.

[0022]

According to the first aspect of the present invention, a mirror whose shape is controlled by air pressure is used for the actuator of the mirror of the light control element, so that the mirror is rotated without being affected by the charged material near the mirror. be able to. Therefore, there is an effect that the mirror rotation angle can be open-controlled by the air pressure supplied to the tube without using the rotation angle detector in order to simplify the structure. Further, by providing the pivot for supporting the mirror on the side opposite to the reflection surface, there is an effect that the aperture ratio can be increased.

According to the second aspect of the present invention, since the tube whose shape is controlled by hydraulic pressure is used for the actuator of the mirror of the light control element, the mirror can be rotated without being affected by the charged material near the mirror. Can be done. Therefore, there is an effect that the mirror rotation angle can be open-controlled by the hydraulic pressure supplied to the tube without using a rotation angle detector to simplify the structure. Further, by providing the pivot for supporting the mirror on the side opposite to the reflection surface, there is an effect that the aperture ratio can be increased.

According to the third aspect of the present invention, the light control element is disposed between the movable mirror that reflects the incident light and the light receiving unit that receives the incident light, so that the light control element is driven by the motor based on the gyro signal. The primary light stabilized by the movable mirror is secondarily stabilized by a mirror device composed of a light control element having one degree of freedom controlled based on a gyro signal and an angle sensor signal. There is an effect that an image in which dimensional vibration is suppressed can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing Embodiment 1 of a light control element according to the present invention.

FIG. 2 is a diagram showing Embodiment 1 of the light control element according to the present invention.

FIG. 3 is a diagram showing Embodiment 1 of the light control element according to the present invention.

FIG. 4 is a diagram showing Embodiment 2 of the imaging apparatus according to the present invention.

FIG. 5 is a diagram showing Embodiment 2 of the imaging apparatus according to the present invention.

FIG. 6 is a diagram showing Embodiment 2 of the imaging apparatus according to the present invention.

FIG. 7 is a diagram showing a conventional light control element.

FIG. 8 is a diagram showing a conventional light control element.

FIG. 9 is a view showing a conventional light control element.

FIG. 10 is a diagram illustrating a conventional imaging device.

FIG. 11 is a diagram illustrating a conventional imaging device.

[Explanation of symbols]

1 mirror device, 2 planes, 3 light control elements, 4 mirrors, 5 torsion hinges, 6 torsion hinges, 7 beams, 11 vertical planes, 12 broken lines, 13 broken lines, 14 axes,
15 edges, 16 landing electrodes, 17 control electrodes,
18 positive electrode, 19 inverter, 20 negative electrode, 21
Electrode, 22 flexible pivot, 23 flexible pivot, 31 imaging device, 32 imaging unit, 33
First frame, 34 gyro, 35 first bearing, 36 movable mirror, 37 first motor, 38 first electronic control unit, 39 first angle sensor, 40 fixed mirror, 41 base, 42 pivot A, 43 Pivot B, 44 Tube A, 45 Tube B, 46
Cavity A, 47 Cavity B, 51 Air inlet / outlet, 52 Air distribution pipe, 60 Mirror device, 61 Second electronic control device, 62 Second frame, 63 Second bearing, 64
Second motor, 65 second angle sensor, 66 mirror device, 67 second electronic control unit.

Claims (3)

[Claims] A mirror having a reflecting surface for incident light; a base for holding the mirror in a plane; a flexible pivot joined to the base so that the mirror can be rotated about one axis; While supporting the base away from the pivot, an airtight cavity and an air inlet / outlet to the cavity are provided, and a tube that can be deformed in the direction of the mirror in response to a change in atmospheric pressure in the cavity and the tube are fixed. An optical control element, comprising: a beam to be adjusted; and a pressure adjusting device that adjusts an atmospheric pressure in the cavity so as to move the base and rotate the mirror. 2. A mirror having a reflecting surface for incident light, a base for holding the mirror in a plane, a flexible pivot joined to the base so as to rotate the mirror about one axis, and A tube that is separated from the pivot and supports the base, and is provided with a watertight cavity and a liquid inlet / outlet to the cavity, and a tube that can be deformed in the direction of the mirror in response to a change in liquid pressure in the cavity; Light, comprising: a filled liquid, a beam for fixing the tube, and a pressure adjusting device for adjusting the pressure of the liquid in the cavity so as to move the base and rotate the mirror. Control element. 3. An imaging unit that converts incident light into an electric signal using a built-in imaging device, a housing to which the imaging unit is fixed, and a movement of the housing fixed to the housing and detected. A gyro, a bearing fixed to the housing, a movable mirror supported by the bearing so as to be rotatable about one axis perpendicular to the visual axis of the imaging unit, and a movable mirror supported by the housing. A motor for driving a movable mirror, a first electronic control device for controlling the motor to cancel the shaking of the movable mirror with respect to a space based on a signal from the gyro, and a movable mirror fixed to the housing. 2. An angle sensor for detecting an angle with respect to the housing, and a plurality of light control elements according to claim 1 fixed to the housing at a position where incident light from the movable mirror is reflected to the image pickup unit. Mirror device And controlling the light control element based on a difference between an integrated value of the gyro signal and a measured value of the angle sensor so that a pointing error of the movable mirror with respect to a command value of the first electronic control device is canceled. An imaging device comprising: the electronic control device according to claim 2;