JPH10186433A - Apex angle variable prism device, and camera shake correcting device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the rotating and driving part of a spherical lens small in size and flat. SOLUTION: In this apex angle variable prism device, an apex angle variable prism 2 consisting of spherical lenses 3 and 4 whose spherical surface are opposed to each other, is used, and rotated on the line linking the almost center of either of the spherical surfaces to the outer edge of the lens as the axis of rotation U. The spherical lens is provided with the rotating and driving part 1B at one part of its outer edge so that it can rotate around the axis of rotation with a rotating and supporting part 1A as the center. The rotating and driving part is constituted as a linear motor 70 and rotated on a plane Z perpendicular to the axis of rotation U. Since it is constituted as the linear motor, the device is made small in size and flat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable apex angle prism device using a doublet type variable apex angle prism, which is constructed by arranging two spherical lenses such that their spherical surfaces face each other. The present invention relates to a camera shake correction device used. More specifically, in order to vary the optical axis by slightly rotating the plano-concave and plano-convex lenses around the center of each spherical surface and varying the apex angle of the prism, the lens driving unit is configured as a linear motor. Thus, the camera shake correction device itself can be reduced in size and flattened, and the camera shake of the television camera body can be easily corrected.

[0002]

2. Description of the Related Art In recent years, a camera shake correction device has been provided to suppress a shake of a shot image due to vibration (camera shake) transmitted to a camera at the time of shooting with a television camera. This is achieved by mounting a detection sensor (angular velocity detection sensor, acceleration detection sensor, etc.) for detecting the angle and posture of the camera body in the TV camera, and according to the output, a variable prism (camera shake correction device) By changing the apex angle of (1) and tilting the optical axis, the shaking of the image due to the shaking of the camera body is canceled.

As such a camera shake correction apparatus, for example, Japanese Patent Laid-Open No. 61-269572 is known. The vertical angle variable prism used as this camera shake correction device encloses a special liquid in the lens optical axis by sandwiching it with a plate glass, and changes the vertical angle of the prism by changing the angle posture of one of the glass plates. In this way, the optical axis is corrected by the angle at which the camera shakes.

In such a liquid-encapsulated variable-angle prism, liquid is sealed between the plate glass and the bellows connecting the plate glass, so that when the angle of the slope glass is changed, the sealed liquid acts as viscous resistance, There is a disadvantage that it is difficult to follow a high-speed shake.

As a means for solving this problem, a doublet type variable apex angle prism combining a pair of spherical lenses can be considered. Referring to FIG. 7, the principle of the variable apex angle prism will be described.

A wedge-shaped prism 1 shown in FIG. 1A has a refractive index n and an apex angle α. In this wedge-shaped prism 1, a refraction angle θ is generated on an outgoing optical axis F1 with respect to an incident optical axis F. The relationship between the refraction angle θ and the vertex angle α is expressed as follows: θ = (n−1) α (1)

On the other hand, the apex angle variable prism 2 to which the present invention is applied is constituted by a pair of spherical lenses, in this example, a plano-concave spherical lens 3 and a plano-convex spherical lens 4, as shown in FIG. Are opposed to each other with a slight gap 5 kept between the spherical surfaces 3a, 4a. The refractive index n of the plano-concave lens 3 and the plano-convex lens 4 and the radii of curvature of the spherical surfaces 3a, 4a are substantially equal.

As shown by a dotted line in FIG. 1B, the apex angle variable prism 2 has a plane 3 of a plano-concave lens 3 and a plano-convex lens 4.
When b and 4b are perpendicular to the optical axis F, the light is not refracted. However, as shown by the solid line, when the plano-concave lens 3 and the plano-convex lens 4 are relatively rotated in the direction of the arrow x along the spherical surfaces 3a, 4a to form a vertex angle α between the planes 3b, 4b. Equation (1) equivalent to wedge-shaped prism 1
As a result, an output optical axis F1 with respect to the incident optical axis F is generated.

The spherical surface 3a of the plano-concave lens 3 and the plano-convex lens 4
By making the relative rotation direction along 4a a biaxial right-angle direction and freely controlling the rotation angle, the refraction direction and refraction angle θ of the output optical axis F1 can be freely changed in any direction, up, down, left and right. can do. Therefore, if the apex angle variable prism 2 is attached to a video camera body and applied to a camera shake correction device, the screen shake can be corrected.

Incidentally, the pair of spherical lenses 3 and 4 constituting the variable apex angle prism 2 must be slid without damaging each other. In this case, the lens is used as the center of rotation of each spherical lens. Instead of taking two rotation axes perpendicular to the plane passing through the center of the spherical surface and perpendicular to the lens optical axis (the optical axis of the original optical system for correcting the blur), the center of the lens spherical surface and the vicinity of the outer edge of each spherical lens are not taken. A method of setting the rotation axis on a straight line passing through one point is conceivable.

FIG. 8 is a cross-sectional view showing the guiding method, and is an example in which the optical axis of the television camera can be changed by being attached to a lens barrel (described later) of a television camera lens. In the figure, only the plano-convex lens 4 is shown for the lens support 1A and its rotation drive 1B. Plano-concave lens 3, plano-convex lens 4
A lens barrel that holds the respective supporting portions and the driving portions and attaches them to the imaging lens is also omitted.

FIG. 9 is a sectional view of the lens barrel 20, and FIG. 10 is a perspective view of the lens barrel. As shown in FIG. 9, the lens barrel 20 is used to connect the variable apex angle prism 2 to the imaging lens L, and is configured as a cylinder having a flange 20a as shown in FIG. The lens rotation support portion 1 is provided at a predetermined location on the flange 20a or the like.
A notch is provided for attaching A or the like.

As shown in FIG. 8, a plano-concave lens 3 is placed with its plane 3b facing the object side of the camera, and a plano-convex lens 4
Is arranged to face the spherical surface 3a of the plano-concave lens 3 with the spherical surface 4a thereof with a small gap. The plane 4b of the plano-convex lens 4 is arranged close to the imaging lens L and with a gap that does not hinder the rotation of the plano-convex lens 4.

Next, the lens rotation support means will be described by taking the plano-convex lens 4 as an example. First, the bearing 8 side of the lens rotation will be described. In FIG. 8, a steel ball 6 is placed on an imaginary rotation axis U serving as a rotation center of the plano-convex lens 4. The steel ball 6 is rotatably supported by a bearing body 17 and a bearing cover 15 to form a pivot bearing 8, which functions as a pivot point in any direction.

It is desirable to position the steel ball 6 as close as possible to the plano-convex lens 4 which is the object to be rotated in order to reduce the overall size. The shaft 10 has one end pressed into the steel ball 6,
Further, the other end is pressed into the holding frame 11. Holding frame 11
Is fixed to the plano-convex lens 4. That is, as shown in FIG. 9, a pair of positioning pins 12 pressed into the plano-convex lens 4 are used.
Are fitted into holes (round hole and long hole configuration) provided in the holding frame 11 so that both are positioned. The plano-convex lens 4 and the holding frame 11 are fastened by screws 13 so that the plano-convex lens 4 and the holding frame 11 move integrally.

A pivot bearing 8 using steel balls 6 is constructed as shown in FIGS.

The bearing cover 15 is fastened to the bearing main body 17 by screws 16 and the steel ball contact surface provided on the bearing cover 15 and the bearing main body 17 is formed as a conical surface, so that the steel ball 6 is smooth without play. It can rotate. With this structure, the holding frame 11 and the plano-convex lens 4 integrally fixed to the holding frame 11 can freely rotate around the steel ball 6 as long as there is no other constraint.

The plano-convex lens 4 thus pivotally held
The rotation holding frame 11 is positioned by a pair of left and right positioning pins 19 provided on the bearing portion 8, and is fixed to the flange 20 a of the lens barrel 20 by screws 18 in that state as shown in FIG. 9. . FIG. 11 is a perspective view when the pivot bearing 8 and the rotation holding frame 11 are viewed from the lower front surface.

Next, a description will be given of a lens driving system 1B for applying a driving force for rotating the plano-convex lens 4. FIG.
FIG. 3 is a perspective view of the mechanism as viewed from an imaging lens side. The fixing portion 21 of the plano-convex lens 4 is screwed to the plano-convex lens 4
Is fixed to the drive-side holding frame (drive frame) 22.

The drive frame 22 is connected to the drive frame 22 so as to restrict the drive frame 22 to rotate only around the virtual rotation axis U, as shown in FIG. The back surface 24 of the arm 38 functions as a contact surface. As is clear from FIG. 13, the contact surface 24 is a surface K (see FIG. 8) perpendicular to the rotation axis U. The contact surface 24 is a contact portion 26
The contact portion 26 also serves as a mounting portion for the DC motor 25. The contact portion 26 is provided with a pair of ball bearings 52 as shown in FIG. It is devised to move.

A pressing means 60 as shown in FIG. 8 is provided so that the surface of the arm 38 makes good contact with the ball bearing 52. The pressing means 60 includes a pressing element 61 for pressing the back side of the arm 38 and a spring 62. Although not shown, a support screw 63 for supporting the spring 62 is attached and fixed to the lens barrel 20 side.

The bearing shaft 54 shown in FIG. 13 is fixed to the contact portion 26 while being pressed by the leaf spring 55 shown in FIG. As shown in FIG. 14, the bearing shafts 54 are parallel to a plane K (see FIG. 8) perpendicular to the rotation axis U, and are provided at two locations radially from the rotation center in this plane. Therefore, with this configuration, the plano-convex lens 4 is held in space by three points of the bearing 8 and the two bearings 52, and is guided along one plane perpendicular to the virtual rotation axis U. become.

Next, the driving mechanism of the plano-convex lens 4 is shown in FIG.
4 and FIG. As shown in FIG. 14, a steel belt 45 is fixed to a pulley 44 attached to the motor 25 by means of a screw 46a via a washer so that the steel belt 45 is attached without slipping and without being damaged. The steel belt 45 is wound around a pulley 44 of about 360 ° in a so-called α-winding state, and then wound around the arm 38 of the drive frame 22 shown in FIG.

At the crossing portion of the α-winding, a hole is formed in one side of the steel belt 45, and the other 45a has a narrow width so that the steel belt 45 crosses without overlapping. A part of the steel belt 45 is fixed to the arm 38 by a screw 46b.

As shown in FIG. 15, the arm 38 of the drive frame 22
A hollow hole is formed (only the right side is shown in the figure), and a compression coil spring 47 is fitted into this hole, and a shaft 48 into which a guide 49 is press-fitted is fitted as a guide rod, thereby forming a steel belt. 45 is given a predetermined tension.

The contact portion 26 is, as shown in FIG.
It is attached via a columnar column portion 40 so as to straddle the cut-out portion of the flange 20a provided at 0.

When the motor 25 rotates in the xa or xa 'direction as shown in FIG.
The arm 38 (the drive frame 22) also rotates in this direction or the xb direction. FIG. 16 shows a state of rotation when rotated in the xa direction. When the arm 38 rotates, the plano-convex lens 4 also rotates via the drive frame 22 (see FIG. 4). As the motor 25, a motor having a body length is used to reduce inertia.

The contact portion 24 of the bearing 52 rotates along a plane K perpendicular to the rotation axis U. Therefore, the plano-convex lens 4
Is a rotation about an axis passing through the center of the convex spherical surface 4a, and even if the partial convex spherical surface 4a rotates, it does not deviate from the entire spherical surface.

FIG. 18 is a conceptual diagram intuitively explaining that the spherical surface of the plano-convex lens 4 is included in the same spherical surface before and after the movement due to such movement. A part of the spherical surface that rotates about the diameter of the sphere B does not deviate from the original spherical surface even if it moves by rotation, and the surface perpendicular to this diameter is also the same. Therefore, the spherical bearing can be rotated without deviating from the spherical surface of the sphere B by the pivot bearing 8 at one point on the diameter and guiding along the surface perpendicular to the diameter.

[0030]

By the way, in order to rotate the spherical lenses 3 and 4 by a predetermined amount in the z plane as described above, a motor 25 having a body length is used in the example shown in FIG. I have. Therefore, as is apparent from FIG. 17, the motor 25 protrudes from the front surface of the lens barrel 20, which hinders miniaturization and flattening of the camera shake correction device.

Although it is possible to move the motor 25 to the inner lens 4 side in order to achieve flattening, the pressing means 60 then projects to the spherical lens 4 side, and such a design change is made. However, this does not contribute to downsizing or flattening of the device.

Therefore, the present invention has been made to solve such a conventional problem and proposes a variable apex angle prism device capable of miniaturizing and flattening as much as possible and a camera shake correction device using the same.

[0033]

According to the first aspect of the present invention, there is provided a prism having a variable apex angle, wherein first and second spherical lenses having spherical surfaces having substantially the same radius are provided. An apex angle variable prism device in which the spherical surfaces are opposed to each other, and are rotated around a straight line connecting the center of one approximately spherical surface and the vicinity of the outer edge of the lens, wherein the spherical lens is centered on a rotation support portion. A rotation drive unit is provided at a part of the outer edge of the spherical lens so as to be able to rotate around the rotation axis, and the rotation drive unit is configured as a linear motor.

In the image stabilizing apparatus according to the present invention, first and second spherical lenses having spherical surfaces having substantially the same radius are combined with their spherical surfaces facing each other, and one of the approximately spherical center and the lens outer edge are formed. An apex angle variable prism device configured to rotate with a straight line connecting the vicinity as a rotation axis, wherein the spherical lens has an outer edge of the spherical lens so that the spherical lens can rotate around the rotation axis about a rotation support portion. A rotation drive unit constituted by a linear motor is provided in part, and the apex angle variable prism device is attached to an imaging optical system of a television camera, and the spherical lens rotates based on a shake component of the television camera. The angle is controlled to correct the optical axis.

In the present invention, a linear motor is used as a rotation drive unit (rotation drive unit) for the lenses 3 and 4. The linear motor only slightly projects in the direction of the z-plane, which is the rotation plane of the lenses 3 and 4, and hardly projects in the direction of the optical axis F on either the front side or the rear side of the lens.

For this reason, even if the rotation driving parts are attached to both the lenses 3 and 4, there is no possibility that the entire apparatus becomes large. Therefore, according to the present invention, the device can be reduced in size and flattened. Miniaturization and flattening also reduce the weight of the device itself.

[0037]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a vertical angle variable prism apparatus according to the present invention;

FIG. 1 is a sectional view of a main part of a variable apex angle prism device which is a main part of a camera shake correction apparatus according to the present invention.

The variable apex angle prism device according to the present invention comprises:
Only the rotation drive unit 1B for imparting lens rotation in the apex angle variable prism device shown in FIG. 8 is changed as shown in FIG. Therefore, the same components as those in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 shows only a lens driving system for one spherical lens 4. Since the other spherical lens 3 is similarly configured, its description is omitted. In FIG. 1, a flat mounting arm 38 (see FIG. 2) is provided on a drive frame 22 provided at a position 180 ° away from the rotation supporting portion 1A, and a linear motor 70 is provided at a predetermined position.

The linear motor 70 is composed of a drive coil 71 functioning as a rotor coil, and a pair of stator magnets 72, 73 which are opposed to each other with a small gap therebetween so as to sandwich the drive coil 71. The upper magnet 72 is fixed to the upper mounting plate 75, and the lower magnet 73 is fixed to the lower mounting plate 80.

FIG. 2 is a plan view of the linear motor 70 with the upper magnet 72 removed, and the drive coil 71 is wound around a spherical center O2 in a fan shape and provided on the mounting arm 38. Recess 38a (see FIG. 3).

The reason why the drive coil 71 is wound in a fan shape is that the lens 4 moves in an arc shape (arrow a in FIG. 2), and a rotating force is efficiently generated in that direction.

A part of the mounting arm 38 has a pair of ball bearings 76a and 76b whose axes are directed toward the center of the spherical surface.
5. The ball bearing 76 functions as a rotation guide for smoothly rotating the spherical lens 4.

Further, a suction magnet 77 is provided between the pair of ball bearings 76a and 76b at a predetermined position of the mounting arm 38 such that the ball bearing 76 stably contacts and slides on the upper mounting plate 75. The upper mounting plate 7 which is mounted and fixed and faces the upper mounting plate 7
A magnetic plate 78 (see FIG. 1 and FIG. 3) is attached to the surface 5. Attach arm 3 by the attractive force of magnet 77
8 can be pressed against the upper mounting plate 75, and stable lens rotation can be realized.

Magnets 72 and 73 are arranged on both upper and lower surfaces of the drive coil 71. FIG. 2 shows the lower magnet 73.
Only shown. The magnets 72 and 73 are not disposed so as to face the entire surface of the drive coil 71, and the left and right coil sides 71a,
The plate magnets 73a and 73b are arranged so as to face the coil sides 71a and 71b so that a driving force is generated in the direction of the arrow a by the current flowing through the coil 71b.

FIG. 4 also shows the upper side of the coil sides 71a and 71b.
The pair of plate-like magnets 72a and 72b are arranged to face each other. With this configuration, the coil sides 71a, 71b
The magnets are arranged on both upper and lower surfaces, respectively, and the coil sides 71a and 71b are placed in the magnetic field.

As shown in FIG. 2, the width W of each of the magnets 72 and 73 is equal to the coil side 71 even when the lens 4 is at the maximum rotation angle.
The width is selected so that a and 71b do not come off the magnets 72 and 73. This is because if the coil sides 71a, 71b deviate from the magnets 72, 73, the desired rotational power cannot be obtained.

The pair of magnets 72 and 73 are fixed to the base 87 by screws 83 and 85 using spacers 82 and 84 so that the magnets 72 and 73 can always maintain a fixed interval. The base 87 can use the flange 20 a of the lens barrel 20 or the like.

FIG. 5 shows a state in which the above-described variable apex angle prism device 2 is attached to the lens barrel 20. In this example, for the sake of easy understanding, one of the rotation driving units 1B shows only the driving coil 71. The other rotary drive 1B 'is shown with magnets 72 and 73 as the center.

In the linear motor 70 thus configured, the magnetic path is formed between the magnets facing each other as shown in FIG.
1a and 71b, the coil sides 71a and 7
The polarities of the magnets 72 and 73 are mounted in opposite directions so that the direction of the force generated between the magnets 72 and 73 is the same.

In FIG. 2, when a clockwise current is applied to the drive coil 71, a rightward force is generated in the drive coil 71 by Fleming's left-hand rule.
Can be turned to the right. If a current is passed in a counterclockwise direction, the lens can be turned to the left, so that the lens 3 or 4 can be turned by a predetermined angle and the optical axis of the apex angle variable prism can be changed, similarly to the conventional drive motor 25.

As shown in FIG. 3, since the linear motor 70 is small and flat, even if this configuration is adopted for the pair of spherical lenses 3 and 4, it is possible to reduce the size and flatness of the entire apex angle variable prism device. Can be achieved.

Next, FIG. 6 shows an embodiment in which such an apex angle variable prism device is applied to camera shake correction of a television camera. FIG. 6 is a system diagram of a main part of the camera shake correction device.

The variable apex angle prism device 2 of FIG. 1 having a combination of concave and convex lenses is mounted on the front surface of the imaging lens 201. Therefore, the plano-concave lens 3 and the plano-convex lens 4 can freely rotate in two axial directions orthogonal to the optical axis. When the two orthogonal axes are a horizontal axis x which is a horizontal scanning direction and a vertical axis y which is a vertical scanning direction, when the plano-concave lens 3 is rotated in the horizontal direction, the plano-convex lens 4 is rotated in the vertical direction,
The optical axis is corrected.

In FIG. 7, a subject image is formed on a CCD 202 in this example, which is an image pickup device, via a variable apex angle prism 2 and an image pickup lens 201, and is converted into a signal.
The image signal is subjected to predetermined signal processing by a camera signal processing circuit 230 at the subsequent stage to generate a video signal.

An angular velocity sensor 203, 20 which is a shake detection sensor for the camera body, in this case, the imaging lens 201.
4 is attached. The sensor 203 detects a vertical shake, and the sensor 204 detects a horizontal shake.

Each of the detection signals (x and y signals for convenience) is amplified by the amplifiers 205 and 206, and then supplied to the filter 207 to pass only the band of the vibration component to be removed. A filter 207 is provided for each of the x and y signals, but is omitted in the figure.

Thereafter, A in the microcomputer 209
/ D converter 231. The digitized angular velocity signals x and y are integrated by the integrator 232 and smoothed, and then the integrated signal (signal corresponding to the rotation angle) Lx,
Ly is supplied to the Y-axis calculation means 233 and the X-axis calculation means 234 to correct the posture of the lenses 3 and 4.
It is converted to x and Sy. These signals Sx and Sy are the target values for which the shake is to be corrected.

The posture of the pair of lenses 3 and 4 constituting the above-described variable apex angle prism 2 is not necessarily in the posture of the initial state (the initial position in which none of the lenses is rotated), but in the x and y directions. It is also conceivable that it is rotating (tilting).

Accordingly, in the present invention, a pair of lenses 3, 4
Encoders (rotary encoders) 210 and 211 for detecting the rotation angle of the lens drive motors 220 and 2
21 is provided.

The encoded outputs from the encoders 210 and 211 are supplied to signal processing circuits 212 and 215 and output as rotation angle signals θx and θy in the x-axis and y-axis directions, respectively.

The rotation angle signals θx and θy are supplied to the amplifier 2
After being converted into digital signals by A / D converters 237 and 238 in the microcomputer 209 via the digital cameras 35 and 236, the converted signals are output (conveniently Dx and Dy).
And the rotation angle correction signals (represented by Δθx and Δθy for convenience) calculated by the rotation angle correction amount calculation means 240 and 241 are supplied to the corresponding calculation means 233 and 234, and the optical axis correction for the lenses 3 and 4 is performed. Are calculated and output as the signals Sx and Sy for use.

The arithmetic processing by the arithmetic means 233 and 234 is as follows: Sx = Lx−Dx + Δθx (2) Sy = Ly−Dy + Δθy (3)

Here, Δθx is a correction rotation angle amount and a correction signal used when the lens 4 is rotated in the y-axis direction due to camera shake, and details thereof are omitted, but can be approximated by the following equation.

[0066]

(Equation 1)

Here, α is the angle (tilt angle) between the rotation axis U of one spherical lens 4 shown in FIG. 1 and the optical axis F, and β is the rotation axis of the other spherical lens 3 (not shown). )
And the optical axis F.

Similarly, Δθy is a correction rotation angle and a correction signal used when the lens 3 is rotated in the x-axis direction due to camera shake, and can be approximated by the following equation as in the above case.

[0069]

(Equation 2)

Therefore, in addition to the integrated signal Ly obtained when camera shake occurs in the y-axis direction,
Rotation angle signal Dy and rotation angle correction signal Δθ for lens 4
y is given. Similarly, the other arithmetic means 234 has x
Integral signal Lx obtained when camera shake occurs in the axial direction
In addition, a rotation angle signal Dx and a rotation angle correction signal Δθx for the lens 3 are provided.

Equation (3) will be described. First, when the lenses 3 and 4 are both at the initial position (the state in which the rotation of the lenses is not corrected at all), Dx = Dy = 0 (4). At this time, when the camera body shakes in the x-axis direction due to camera shake, the integration signal L related to the sensor 203 is output.
x is obtained, and an optical axis correction signal Sx for correcting this is generated.

The rotation of the lens 3 is controlled by the optical axis correction signal Sx. When the lens 3 rotates by φ by the rotation of the lens 3, an encode signal θx is obtained at that time. The rotation angle canceling signal (rotation angle correction signal) Δθy is calculated based on the encode signal θx, that is, Dx, and the lens 4 is rotated by adding this.

That is, Sy = Δθy (5) Therefore, when the lens 4 has already been rotated, (θy
≠ 0), and the difference, Sy = Δθy−Dy (6), may be used to correct the lens 4.

When there is camera shake also in the y-axis direction, since the integrated signal Ly related to the sensor 204 has been obtained, the optical axis correction signal Sy finally applied to the lens 4 to correct this is Sy = Ly−Dy + Δθy (7) Equation (2) can be derived for the lens 4 based on the same concept.

As described above, the use of the variable apex angle prism apparatus shown in FIG. 1 makes it possible to easily correct the camera shake of the television camera.

[0076]

As described above, according to the present invention, when using a doublet type apex angle variable prism in which a pair of spherical lenses are combined, one point on the outer edge of the lens in a direction perpendicular to the optical axis and orthogonal to each other. A lens drive unit having a linear motor structure is configured as a lens drive system in a case where an axis passing through the lens and the lens center is guided as a rotation axis.

Because of the linear motor structure, the variable apex angle prism device can be reduced in size and flattened. Therefore, the variable apex angle prism device and the image stabilizing device using the same can be reduced in size, and the device can be made inexpensive accordingly. Can be provided.
Therefore, the present invention is very suitable when applied to an optical system of a portable video camera used for business or consumer use.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a main part showing one embodiment of a variable apex angle prism device according to the present invention.

FIG. 2 is a configuration diagram of a main part showing an example of a rotation driving unit with a part omitted.

FIG. 3 is a sectional view on the line AA including the upper part.

FIG. 4 is a cross-sectional view on the line BB including the upper part.

FIG. 5 is a partial sectional view showing a state in which a lens is attached to a lens barrel.

FIG. 6 is a system diagram of a main part showing an embodiment of a camera shake correction device to which the apex angle variable prism device according to the present invention is applied.

FIG. 7 is an explanatory diagram of a variable apex angle prism.

FIG. 8 is a sectional view of a main part of the variable apex angle prism device.

FIG. 9 is a partial cross-sectional view showing an example of attaching a lens to a lens barrel.

FIG. 10 is a perspective view showing a schematic shape of a lens barrel.

FIG. 11 is a perspective view illustrating details of a lens support unit.

FIG. 12 is a perspective view illustrating details of a lens driving unit.

FIG. 13 is a cross-sectional view of a main part showing details of a lens driving unit.

FIG. 14 is an exploded perspective view showing an example of a motor transmission system.

FIG. 15 is a front view (part 1) in which a part of an example of a motor transmission system is sectioned;

FIG. 16 is a front view (part 2) in which a part of an example of a motor transmission system is sectioned;

FIG. 17 is a perspective view showing a state where the variable apex angle prism is assembled.

FIG. 18 is an explanatory diagram showing a rotating state of a plano-convex lens.

[Explanation of symbols]

2 ... vertical angle variable prism, 3,4 ... spherical lens,
1A: lens support, 1B: lens drive, 7
0: linear motor, 71: drive coil, 72,
73 ・ ・ ・ Magnet

Claims (4)

[Claims] 1. A first and a second spherical lens having spherical surfaces having substantially the same radius are combined with their spherical surfaces facing each other, and are rotated around a straight line connecting the center of one of the spherical surfaces and the vicinity of the outer edge of the lens. A variable apex angle prism device, wherein the spherical lens is provided with a rotation drive unit at a part of an outer edge of the spherical lens so that the spherical lens can rotate around the rotation axis about a rotation support unit; The drive unit is configured as a linear motor. 2. The variable apex angle prism according to claim 1, wherein the first spherical lens is a plano-concave spherical lens, and the second spherical lens is a plano-convex spherical lens. 3. The linear motor includes a drive coil, and fixed magnets disposed opposite to each other so as to sandwich the drive coil from above and below. The drive coil is used as a rotor, and the magnet is used as a stator. The variable apex angle prism according to claim 1, wherein the driving coil is provided on a lens fixing portion side of the spherical lens. 4. A first and a second spherical lens having spherical surfaces having substantially the same radius are combined so that the spherical surfaces are opposed to each other, and the first and second spherical lenses are rotated around a straight line connecting the center of one substantially spherical surface and the vicinity of the outer edge of the lens. A variable apex angle prism device, wherein the spherical lens is rotatable around a rotation axis around the rotation axis so that a part of an outer edge of the spherical lens is a rotation driving unit configured by a linear motor. The variable apex angle prism device is attached to the imaging optical system of the television camera, and the rotation angle of the spherical lens is controlled based on the shake component of the television camera so that the optical axis is corrected. A camera shake correction device, characterized in that: