JP3355787B2 - Optical axis correction mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel optical axis correcting mechanism. Specifically, for example, in a use state such as a handy type video camera device, there is no so-called camera shake correction .
Etc. in which it relates to video cameras necessary, and to provide a novel optical axis correcting mechanism that can improve the accuracy of such camera shake correction.

[0002]

2. Description of the Related Art For example, in a handy type video camera apparatus, as a method for correcting camera shake, an afocal lens composed of a convex lens and a concave lens is disposed as an optical axis correcting lens in front of a taking lens system. A method of correcting camera shake by moving a concave lens in a direction perpendicular to the optical axis (ABS method) is known.

In such an ABS system, the position of the optical axis correcting lens must be detected. As a means for this, the position of the optical axis correcting lens is set in two directions orthogonal to each other, for example, the HV direction ( H direction is defined as the horizontal direction, and V direction is defined as the vertical direction.), And the positions of the optical axis correcting lenses in the respective directions may be separately detected by two position sensors.

FIGS. 7 to 9 show a method of correcting camera shake by moving an afocal lens composed of a convex lens and a concave lens as an optical axis correcting lens and moving the convex lens among these lenses in a direction perpendicular to the optical axis. FIG.

[0005] In addition, "h" added to the reference numeral of each member described later.
Alternatively, as for the suffix “v”, “h” indicates a value in the horizontal direction, and “v” indicates a value in the vertical direction.

Reference numeral a denotes a photographing lens system, and an image pickup device (CCD) b is disposed behind the photographing lens system.

[0007] Reference numeral c denotes a convex lens for correction positioned on the photographing lens system a side of the optical axis correcting lens constituted by an afocal lens, and the convex lens for correction c is located near the front of the photographing lens system a. The optical axis x 'is always parallel to the main optical axis x of the photographic lens system a.

Eh and ev are linear motors for driving the correcting convex lens c. The yokes fh and fv attached to the lens barrel (not shown) and the magnets gh and gv attached to the yokes fh and fv. And a moving coil hh, hv, etc. attached to the correction convex lens c side. One (for the V direction) linear motor ev is located at a position near the upper end of the correction convex lens c and the other (for the H direction). Are disposed at positions near the right end of the correcting convex lens c (see FIG. 8).

Reference numerals ih and iv denote position sensors for detecting the position of the correcting convex lens c. For example, light emitting diodes (LED) jh and jv and a semiconductor position detecting element (PS)
D) kh, kv, etc., and PSDkh, kv are formed in a rectangular shape whose light receiving surface is long to one side.

The LEDs jh and jv are peripheral portions of the correcting convex lens c and are located at positions separated from each other by 90 degrees at the center angle on the opposite sides from the positions where the linear motors eh and ev are arranged, that is, the vertical linear motors. ev and a position opposing the optical axis x with the optical axis x therebetween, and the horizontal linear motor eh and the optical axis x
Are attached at positions facing each other with the.

The PSDkh and kv are supported by a lens barrel (not shown) at positions facing the LEDs jh and jv, respectively.
Are extended in substantially the same direction as the tangential direction of.

The vertical component of the correcting convex lens c is obtained by a position sensor iv disposed at a position opposed to the horizontal linear motor eh across the optical axis x, and the horizontal component of the correcting convex lens c is obtained. Is the vertical linear motor ev
And a position sensor ih disposed at a position facing the optical axis x.

Reference numerals lh and lv (only the component for the V-direction component in FIG. 7) denote a camera shake detection sensor comprising an angular velocity sensor. When a camera shake is detected, a shake detection signal is output. Therefore, this is integrated by the camera shake amount calculation circuits mh and mv to detect a change in angle.

The angle data detected by the camera shake amount calculation circuits mh and mv are compared with the position data of the optical axis correction lens c obtained by the position sensor ih or iv by the correction lens position control circuits nh and nv. The amount of the angle to be corrected is detected, and this correction data is stored in the linear motor eh.
Alternatively, the signal is output to ev, and the optical axis correcting lens c is moved in the vertical or horizontal direction, so that the optical axis is corrected.

Such an ABS type optical axis correcting mechanism is excellent in responsiveness because it only moves the correcting convex lens c in the direction opposite to the camera shake direction.

[0016]

However, in such a camera shake correction system based on the ABS method,
Two similar position sensors ih in the horizontal and vertical directions,
Since iv is arranged on the correction convex lens c, so-called crosstalk may occur between the two position sensors, and erroneous position detection may occur.

In addition, the correction convex lens c may not only move in the HV direction, but also cause so-called rolling to rotate around the optical axis x '(see FIG. 9).

The rolling itself does not affect the image quality. However, since the correcting convex lens c is rotated about the optical axis, the horizontal and vertical directions are set at the positions where the LEDs jh and jv are attached. A motion having a component of

The position sensors ih and iv erroneously detect that the correction convex lens c has moved in the horizontal direction or the vertical direction, respectively, and have a problem in that the components in the horizontal direction or the vertical direction are erroneously detected.

[0020]

In order to solve the above-mentioned problem, the optical axis correcting mechanism of the present invention drives a correcting lens by a lens driving means in a so-called ABS system to remove a vertical component caused by a shake. In addition, the camera shake correction is performed, and the horizontal component due to the shake is corrected by rotating the lens barrel by a so-called gimbal type lens barrel driving unit.

[0021]

Therefore, according to the optical axis correction mechanism of the present invention, the motion component due to the shake is decomposed into a vertical component and a horizontal component, and the vertical camera shake is corrected by the so-called ABS method. Since the direction shake is corrected by the so-called gimbal method, the two position sensors can be different types, and each of the members is independent of the other members, that is, the correction lens and the lens barrel. As a result, the so-called crosstalk between the two position sensors can be eliminated, and erroneous detection of each position can be prevented.

Also, even if the correction lens is rolling,
Since the position of the correction lens needs to be controlled only in the vertical direction, the position of the correction lens is not erroneously detected.

Furthermore, since most of the shakes occur in the vertical direction, the camera shake in the vertical direction is corrected by the ABS system having good response, so that the camera shake in the vertical direction can be surely corrected. In the horizontal direction, the shake is corrected by the gimbal method.
The range of shake correction can be widened.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the optical axis correcting mechanism of the present invention will be described below according to each embodiment applied to a video camera apparatus.

FIGS. 1 to 5 show a first embodiment of the optical axis correcting mechanism of the present invention.
FIG.

In FIG. 1, reference numeral 1 denotes an optical axis correcting mechanism. The vertical optical axis correcting mechanism 2 is configured by a so-called ABS system, and the horizontal optical axis correcting mechanism 3 is configured by a so-called gimbal system.

The vertical drive mechanism 2 includes a correcting convex lens 5 located on the photographing lens system 4 side of the optical axis correcting lens constituted by an afocal lens, and the correcting convex lens 5 having an optical axis X ′. It has suspensions 6 and 6 movably supported while maintaining a state parallel to the main optical axis X of the taking lens system 4, and lens driving means 7 for moving the correcting convex lens 5 to a predetermined position.

The convex lens 5 for correction is supported by the lens holder 8 and positioned in front of the photographic lens system 4, and its optical axis X ′ is positioned so as to be parallel to the main optical axis X of the photographic lens system 4. You.

The lens holder 8 has a substantially ring shape, and has a coil bobbin 9 integrally protruding upward from an upper end thereof, and an LED mounting portion for mounting an LED of a position sensor described later at a lower end thereof. The piece 10 is integrally protruded downward.

The coil bobbin 9 comprises two bobbin pieces 9a, 9a parallel to each other, and the two bobbin pieces 9a, 9a
And the center of the space between them coincides with the radial direction about the axis of the lens holder 8.

The suspension 6 is provided between two vertical spring pieces 11, 11 which are long and horizontal in the front-rear direction and are vertically separated from each other, and a front end of one side edge of each vertical spring piece 11, 11. And a vertically oriented support piece 12 connecting
The vertical spring pieces 11 are vertically supported pieces 13 which are connected between the rear end portions on the side opposite to the support piece 12 of each of the vertical spring pieces 11.

The suspension 6 is formed by punching and bending a sheet metal material having a predetermined size.

The suspensions 6, 6 formed in this manner have their supported pieces 13, 13 oriented perpendicular to the left and right sides of the lens barrel 14 of the photographic lens system 4, and have the support pieces 12, 13. 12 is fixed by screws or the like in a state where it protrudes forward from the taking lens system 4.

The left and right ends of the lens holder 8 have a predetermined orientation (the coil bobbin 9 at the upper end extends upward, and the LED mounting piece 10 at the lower end faces downward) between the tips of the support pieces 12, 12 of the suspensions 6, 6. In the state in which the vertical spring pieces 11, 11,... Of the suspensions 6, 6 are not bent, the optical axis X 'of the correcting convex lens 5 is set in the taking lens system. 4 is coincident with the main optical axis X.

The lens driving means 7 includes a coil 15 wound around the bobbin pieces 9a of the coil bobbin 9 of the lens holder 8, a yoke 16 having an E-shaped cross section fixed to the main body (not shown), and attached to the yoke 16. Magnet 17, 1
7

The yoke 16 has a middle piece 16a which is formed sufficiently smaller than a distance between the bobbin pieces 9a and 9a of the coil bobbin 9, and has a middle piece 16a.
a is disposed at a position to be inserted from the outside into the space between the bobbin pieces 9a, 9a, and the pieces 16b, 16
The magnets 17, 17 are attached to b.

When power is supplied to the coil 15, the lens holder 8 moves in the up-down direction.
Can be moved in the vertical direction.

Reference numeral 18 denotes a position sensor, which includes an LED 19 attached to the lens holder 8 and a PSD 20 attached to a main body (not shown).

The LED 19 is mounted on the LED mounting piece 10 formed at the lower end of the lens holder 8 with its light emitting side facing the taking lens system 4 side.

The PSD 20 has an elongated rectangular plate shape, the longitudinal direction of which coincides with the vertical direction about the optical axis X of the taking lens system 4, and the light receiving surface of the PSD 20 is the LED.
19, the position of the correcting convex lens 5 is detected.

It should be noted that the range of such vertical camera shake correction may be in the range of about 1.0 to 5.0 degrees in terms of the inclination angle of the optical axis, and is usually set to 1.5 degrees. I have.

The horizontal drive mechanism 3 includes a fixed plate 21 having an inverted L-shape viewed from the front and covering one side and an upper part of the lens barrel 14, and a horizontal plate 21a of the fixed plate 21. There is a lens barrel driving means 22 formed on the lower surface and supporting the lens barrel 14 so as to be rotatable in the horizontal direction.

The fixing plate 21 is not limited to the inverted L-shape as shown, but may be a simple flat plate extending in the horizontal direction.

The lens barrel driving means 22 is a flat motor, and includes a stator 23 fixed to the horizontal plate 21a,
It comprises a rotor section 24 and the like which are arranged opposite to the stator section 23 and fixed to the upper end of the lens barrel 14.

The stator portion 23 includes an iron printed circuit board 25 adhered to the lower surface of the horizontal plate 21a, a cylindrical housing 26 fixed so as to penetrate the printed circuit board 25 and the horizontal plate 21a, Stator coils 27, 2 disposed on printed circuit board 25 so as to surround
7, etc.

The rotor section 24 has a ring-shaped rotor magnet 28 arranged to face the stator coils 27, 27,... Of the stator section 23, and a disk-shaped outer peripheral edge having a short peripheral wall. The rotor case 29 includes a flat rotor case 29 supporting the rotor magnet 28 and a support shaft 30 protruding from the center of the rotor case 29.

The support shaft 30 of the rotor portion 24 is
Is rotatably supported by the housing 26 via a bearing 31, a bearing metal 32, and a sleeve 33, whereby the rotor portion 24 is rotatably supported by the stator portion 23.

As a result, the lens barrel 14 is fixed to the fixed plate 21.
The lens barrel driving means 22 is a lens barrel supporting means for rotatably supporting the lens barrel 14 in the horizontal direction, and a lens barrel for rotating the lens barrel in the horizontal direction. It has a function as a driving means.

The lens barrel 14 is supported such that its center of rotation coincides with the center of gravity of the lens barrel 14.

Then, the stator coils 27, 27,.
By supplying a drive current to the rotor, the rotational force is urged to the rotor magnet 28, the rotor part 24 is rotated, and the lens barrel 14 is rotated in the horizontal direction.

Numeral 34 denotes an angular position sensor, which is fixed to the outer peripheral edge of the rotor case 29 and is attached to the stator portion 23 with a ring-shaped plastic magnet 35 having a large number of S poles and N poles alternately magnetized on the outer peripheral surface thereof. And an MR sensor 36 disposed so as to face the outside of the plastic magnet 35. The rotation of the rotor unit 24 is controlled based on position information from the angular position sensor 34. It has become so.

Reference numerals 37v and 37h denote camera shake detection sensors each composed of an angular velocity sensor. When a camera shake is detected, a shake detection signal is output. Since the shake detection signal is angular velocity data, it is processed by the camera shake amount calculation circuits 38v and 38h. Integral calculation is performed to detect the change in angle.

The suffix of “v” or “h” attached to each member indicates that “v” is related to the vertical (V) direction, and “h” is horizontal (H). ) Direction.

When a camera shake in the vertical direction occurs,
The angle data detected by the camera shake amount calculation circuit 38v is compared with the position data of the correction convex lens 5 obtained by the position sensor 18 by the correction lens position control circuit 39v, and the amount of the angle to be corrected is detected. Then, the correction data is output to the lens driving means 7, and the correction convex lens 5 is moved in the vertical direction to correct the optical axis.

When a shake in the horizontal direction occurs, the angle data detected by the shake amount calculating circuit 38h is converted by the lens barrel position control circuit 39h into the angle position sensor 3h.
4 is compared with the position data of the lens barrel 14 obtained, the amount of angle to be corrected is detected, and the correction data is output to the lens barrel driving means 22 so that the lens barrel 14 rotates in the horizontal direction. By moving the optical axis, the optical axis is corrected.

The range in which the shake correction in the horizontal direction is performed is such that the rotation angle of the lens barrel driving means 22 is 1.
It is sufficient if the angle is in the range of about 0 to 5.0 degrees, but due to its mechanism, the rotation angle can be increased as long as the lens barrel 14 does not collide with the fixed member on the camera side.

When the camera shake is corrected in the vertical direction, the position of the correcting convex lens 5 is detected by the position sensor 18 attached to the lens holder 8, and when the camera shake is corrected in the horizontal direction, the position of the lens barrel 14 is changed. This is detected by the angular position sensor 34 of the lens barrel driving means 22.

FIG. 6 shows a second embodiment of the optical axis correcting mechanism of the present invention.

Optical axis correcting mechanism 1 in the second embodiment
A differs from the optical axis correction mechanism 1 in the first embodiment in that the rotation angle of the lens barrel driving means 22 in the horizontal direction is set to, for example, 30 degrees and used in a tracking mechanism in such a direction. is there. Therefore, only the different parts will be described, and the parts which are not different will be denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

A tracking control circuit 40 detects the movement of a target object in a captured image and outputs the detection signal to the lens barrel driving means 22 as a tracking control signal.

There are various known methods for detecting the movement of a target object in a captured image, but a block matching method is generally used. Regarding the block matching method, the present applicant has filed a 1993 patent application No. 61
No. 060 (filed on Feb. 25, 1993).

Then, upon receiving a control signal from the tracking control circuit 40, the lens barrel driving means 22 is driven, and the photographing lens system 4 is driven.
The lens barrel 14 is rotated so that the axial direction of the main optical axis X is directed to the target object.

The rotation angle of the main optical axis as a tracking mechanism needs to be at least 10 degrees or more.
About 30 degrees is preferable. This is because the higher the upper limit of the rotation range of the tracking mechanism is, the better, but in the case of the gimbal system, the lens barrel 14 is provided in the video camera apparatus.
Is necessary to be rotated.

Thus, in the second embodiment,
The deflection vertical hand that the most frequent in the shake correction with good ABS system responsive, also, it is possible with correcting the shake in the horizontal direction in the gimbal system, thereby also have a tracking function by the gimbal system.

[0065]

As is apparent from the above description, the optical axis correcting mechanism of the present invention comprises an afocal lens composed of two concave and convex lenses disposed in front of the main lens system;
The convex lens of the afocal lens is referred to as a correcting lens.
And a lens support means vertically parallel to movably supported with the main optical axis perpendicular to said correction lens with respect to the main optical axis of the main lens system, a lens drive for moving the correcting lens in the vertical direction Means, a lens barrel accommodating the main lens system, a lens barrel supporting means for rotatably supporting the lens barrel in a horizontal direction, and a lens barrel driving means for rotating the lens barrel in a horizontal direction with the door, the component in the vertical direction of the deflection performed shake correction by driving the correction convex lens by said lens drive means, a component in the horizontal direction of the vibration rotating the lens barrel by the lens barrel driving means And shake correction is performed.

Therefore, according to the optical axis correcting mechanism of the present invention, the vibration
Decomposing the components of the motion by Les the vertical component and the horizontal component,
Vertical camera shake correction is performed by the so-called ABS method.
Since the horizontal shake correction is corrected by a so-called gimbal method, the two position sensors can be different types, and each of the two separate position sensors has a different structure, that is, a correction lens and a lens barrel. It can be provided independently, so that so-called crosstalk between the two position sensors can be eliminated, and erroneous detection of each position can be prevented.

Also, even if the correction lens rolls,
Since the position of the correction lens needs to be controlled only in the vertical direction, the position of the correction lens is not erroneously detected.

[0068] Furthermore, it is often a lot of vibration which occurs in the vertical direction, for correcting the good ABS system responsive to camera shake at the vertical direction, certainly, it can be corrected in the vertical direction of the camera shake, also In the horizontal direction, the shake is corrected by the gimbal method.
The range of shake correction can be widened.

[0069] The structure and shape of each part shown in the above Examples or, specific numerical range such as can be tracked in the correction range and tracking mechanism in such camera shake correction is the implementation of the practice of the present invention They are merely examples and should not be construed as limiting the technical scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first example of an optical axis correcting mechanism according to the present invention together with FIG. 2 to FIG.
FIG. 2 is a perspective view of a main part.

FIG. 2 is a front view schematically showing a main part of a lens driving unit.

FIG. 3 is a sectional view schematically showing a main part of a lens barrel driving unit.

FIG. 4 is an exploded perspective view of a lens barrel driving unit.

FIG. 5 is a schematic diagram showing the entire configuration as viewed from the side.

FIG. 6 shows a second embodiment of the optical axis correcting mechanism of the present invention, and is a schematic diagram showing the entire configuration as viewed from the side.

FIG. 7 shows an example of a conventional optical axis correcting mechanism together with FIGS. 8 and 9, and FIG. 7 is a schematic view of the whole viewed from the side.

FIG. 8 is a schematic diagram viewed from the optical axis direction.

FIG. 9 is a schematic diagram showing a state in which the optical axis correcting lens is rolling.

[Explanation of symbols]

 Reference Signs List 1 optical axis correction mechanism 4 photographing lens system (main lens system) 5 convex lens for correction (lens for correction) 6 suspension (lens support means) 7 lens driving means 14 lens barrel 22 lens barrel driving means 1A optical axis correction mechanism

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-104666 (JP, A) JP-A-63-225119 (JP, A) JP-B-44-5988 (JP, B1) (58) Field (Int.Cl. ⁷ , DB name) G03B 5/00 G03B 17/00 G02B 27/64

Claims (2)

(57) [Claims] 1. An afocal lens comprising two concave and convex lenses disposed in front of a main lens system, and a convex lens of the afocal lens is used as a correcting lens, and the correcting lens is used as main light of the main lens system. Lens support means movably supported in a direction perpendicular to the axis in parallel with the main optical axis, lens driving means for moving the correction lens in the vertical direction, and a lens barrel accommodating the main lens system Lens barrel supporting means for rotatably supporting the lens barrel in the horizontal direction, and lens barrel driving means for rotating the lens barrel in the horizontal direction, wherein the vertical component of the shake is reduced by the lens performs image stabilization by driving the correction convex lens by the driving means,
Optical axis correcting mechanism the components in the horizontal direction of the deflection, characterized in that to perform the pivots lens barrel in shake correction by the barrel driving means. 2. The optical axis correcting mechanism according to claim 1, wherein said lens barrel driving means is used as a driving means of a tracking mechanism for moving an optical axis in accordance with the movement of a predetermined target object.