JP2008131539A - Handheld video camera stabilizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive mechanism having light weight and simple structure for preventing video image from shaking caused by transmission of walking vibration to a camera in walking photographing by a video etc. <P>SOLUTION: The handheld video camera stabilizer includes a balance arm mechanism for attaching to a camera and positioning the centroid at the lower part of the camera, and a triaxial gimbal mechanism by ball joint structure using ball of tiny caliber. The video camera control function and the camera attitude control function such as tilt, pan, vertical movement are added to a grip part connected directly to the ball of the gimbal mechanism. The balance arm mechanism includes static and dynamic attitude adjustment functions of camera attitude. They can be controlled and operated only in the grip part held with one hand. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photographing auxiliary apparatus suitable for use in moving photography by a movie camera such as a video camera or a digital camera with a moving picture photographing function, and in particular, a photographer performs moving photography while supporting the camera with a hand. The present invention relates to an imaging assisting device that makes stable imaging without blurring, and a device that can perform camera function control and camera position control with only one hand holding the imaging assisting device.

When a photographer holds a video camera and is moving while walking, if the photographer's behavior is directly transmitted to the camera, the camera is shaken and it is difficult to obtain a favorable image. Accordingly, various types of photographing assistance devices have been proposed for relaxing the photographer's behavior from being transmitted to the camera (Patent Documents 1 to 3).
Film camera and video camera stabilization devices were devised by Mr. Garrett Brown in 1986 and are now widely used for film and video shooting.

  Patent Documents 1 and 2 disclose providing a spring-added balancing arm for supporting a gimbal (horizontal holding suspension device) -mounted deployment camera system, and solved the problem of camera stabilization for the first time. In movie shooting, television, and video shooting, the photographer attaches a harness that attaches to a spring-equipped balancing arm, and attaches a handle of a three-axis gimbal mechanism using a bearing to which a camera equipped with a balance mechanism is attached. It is used. This type is capable of stable walking photography, but its weight is several tens of kilograms (which has become a topic of causing back pain for photographers), and the system is expensive. Limited to professional use.

  With the recent reduction in weight of video cameras, a simple hand-held camera stabilization device has also been devised, and a typical example is Patent Document 3. The mechanism for isolating the camera system with respect to the movement of the camera as the photographer walks is the same as the former, but without using a spring-equipped balancing arm and attached harness, you must have a grip directly connected to the gimbal device. Thus, it supports the entire camera system.

  In addition, there are several types of gimbal structures as shown below, and there are also types of grips that are located directly below the gimbal in the vertical direction and those that are cantilevered at positions off the vertical axis of the gimbal. Combinations are commercialized and each has advantages and disadvantages.

Prior art examples will be described with reference to prior product examples of Tiffen, Inc., a typical auxiliary device manufacturer. [A] below is a spring-added balancing arm + harness type, and [b] to [e] are handheld types.
[a] United States Tiffen Steadicam Ultra (This is a professional device used for movie shooting. Because it is heavy, it is equipped with an arm that absorbs vibration attached to the harness.)
[b] Steadycam Marine (Tiffen, USA) (This is a new product for handheld shooting for relatively small video cameras.)
[c] Steadicam JR (Tiffen, USA) (This is an old product for handheld shooting for relatively small video cameras.)
[d] Artemis DV, Sahatler, Germany (This is a handheld product for relatively small video cameras.)
[e] Glidecam 2000 Pro of Glidecam (USA) (This is a hand-held shooting auxiliary device for relatively small video cameras.)

As the triaxial gimbal structure, the following two types are mainly proposed and commercialized.
・ Ball bearing gimbal (expensive, low friction. Used in prior product examples [a], [b] and [e].)
・ Ball joint gimbal (simple structure and low cost. High friction. Used in the preceding product examples [c] and [d].)

There are the following two types of grips in relation to the gimbal axis.
A type that allows pan rotation around the Z axis without limitation, and the grip on hand is located away from the Z axis. (Used in the preceding product example [e].)
-A hand grip that passes through the center of the gimbal 3 axis. (Used in the preceding product examples [b], [c], and [d].)

  In both cases, a balance arm and weight are placed at the bottom of the camera, and a three-axis gimbal structure is placed slightly above the center of gravity of the integrated camera and balance arm and weight. it can. In addition, by supporting the grip part connected to the gimbal without the photographer directly supporting the camera, the camera prevents the rotation component from being transmitted to the camera from the rocking motion caused by the photographer's walk. Can be taken.

  Minimizing the distance between the center of gravity of the integrated camera and balance arm / weight and the center of the 3-axis gimbal structure is the decisive factor for taking stable images, and therefore a 3-axis gimbal structure with less friction is provided. And a mechanism for easily and accurately adjusting the position of the balance weight is important.

  In addition, using two cameras to stabilize a stereoscopic video shooting device called a stereoscopic video, a 3D movie, etc., is a product using the prior art of the above-mentioned prior product example [a], There are rare examples of methods using existing stereoscopic cameras. However, since the weight of the mounted camera becomes heavier, it is not popular. The need for stereoscopic walking photography is expected to increase in the future due to the weight reduction of the camera, and the weight reduction of the entire system including the camera is desired.

U.S. Pat.No. 4,017,168 US Pat. No. 5,360,196 (Japanese Special Table No. 8-503763) US Patent No. 4208028 (Japanese Patent No. 2798277)

  Considering the widespread use of these products, at present, a ball joint gimbal with high friction is insufficient to obtain a sufficient swing prevention effect, and a complicated gimbal mechanism using expensive bearings is indispensable. The price is generally higher than that of the camera itself, which has hindered its popularity. Low-friction ball and pan gimbal mechanism and lightweight, compact balance arm weight as a light-weight and high-performance anti-vibration function for small-sized video cameras and digital cameras with video shooting functions that will be in demand Is desired.

  Another problem with the prior art is that it is difficult to operate a camera and a photographing assisting device having a vibration isolation function during shooting while walking. For example, most types of handheld products that are primarily used require operation with both hands, usually in pan and tilt operations. Especially with the type using low friction bearings, it is necessary to manually apply rotational torque to the camera supported by the gimbal mechanism with a hand different from the hand used for grip for pan operation. Yes, it has become an element that breaks the balance obtained by the stabilizer, which leads to requiring skill in operation.

The present invention has been made in view of the above circumstances, and has the following objects.
Using a simple ball joint mechanism, it is possible to perform stable hand-held shooting without blurring in imaging, as well as camera position and direction control during walking shooting using only one hand with a grip. Provided is a shooting assistance device for a video camera that is easy to use.

  Also, the camera function control (REC / STOP, zoom control, etc.) and camera posture control (initial adjustment and shooting operations) can be performed without touching the camera, gimbal mechanism, and balance arm weight with the hand holding the grip. It also provides a mechanism that can perform accurate pan and tilt rotation in the desired direction.

Furthermore, it is easy to adjust the center of gravity to stabilize the camera, and provides various balance arm weights that can be reduced in size and weight for a camera of 1.5 kg or less.

  In the case of a stereoscopic camera, the center of the gimbal can be located above the center of gravity of the camera. Therefore, it is possible to use the camera weight itself as a balance weight, and provide a stabilizing device that can be significantly reduced in weight and size.

  That is, the present invention discloses an improved technology related to high stability, high controllability, light weight, small size, and low price of a hand-held type in which a grip is arranged directly below a ball joint type three-axis gimbal structure. Objective.

In order to achieve the above object, a video camera stabilizing device for handheld according to the present invention comprises:
1) A balance arm / weight mechanism attached to the main body of the video camera (including a digital camera with a moving image function);
2) A grip portion for supporting the video camera body and the balance arm / weight mechanism by hand;
3) A triaxial gimbal mechanism connected to the balance arm / weight mechanism or the video camera main body is located above the grip portion.

In this specification, a video camera is used to include a digital camera with a moving image function.
Here, the balance arm / weight mechanism is fixed to the video camera body with a mounting screw. As long as it has a function of arbitrarily adjusting the position of the center of gravity of the integrated structure of the video camera main body and the video camera stabilization device, in addition to being fixed by the mounting screw, any material and any structure can be adopted.
The structure of the balance arm / weight mechanism includes an arm structure and a balance weight that bypasses the front of the video camera main body and is coupled to a balance weight located at the lower part in order to avoid interference with the grip portion. It is desirable to reduce the weight of this arm structure as long as strength and rigidity allow. Further, the balance weight needs to be provided with a mechanism for adjusting the position manually or electrically in a horizontal plane and a vertical direction by some means.
In addition, in the handheld video camera stabilization device invented so far, the center of the gimbal and the balance arm weight are only located at the lower part of the camera. It is an essential condition that the center of gravity of the integral object is always located below the center of the gimbal, but it is not always necessary that the center of gravity of the camera and the balance arm / weight and the center of the gimbal be positioned below the camera body.
That is, when the gimbal center position can be set higher than the center of gravity position of the camera body, the camera body can function as a balance weight. Although it is not usually possible to place the center of the gimbal inside the camera, depending on the shape of the camera, setting the gimbal position to the left and right of the camera allows the camera body to function as a balance weight. There are cases where the weight can be reduced. For the first time in the present invention, we also propose an arrangement in which the center of the 3-axis gimbal is positioned above the bottom of the camera, increasing the flexibility of arrangement of the balance arm and weight structure, and reducing the weight of the video camera stabilization device for handhelds. Is realized.

In the video camera stabilizing device of the present invention, the balance weight in the balance arm / weight mechanism includes a second video camera body itself which is different from the video camera body.
By using two video camera bodies and using one as a balance weight, it can be used as a handheld video camera stabilization device for stereo video shooting. In some cases, there is a possibility of stabilization even if there is no balance arm / weight at all, and a significant reduction in weight is possible.

In addition, the three-axis gimbal mechanism of the handheld video camera stabilization device of the present invention is preferably configured by a ball joint structure.
As this ball joint structure, for example, a free pan head structure (utilization in a camera stabilizing device is disclosed in Patent Document 3) or a spherical ball bearing structure can be suitably used. In addition, what will be described in the embodiments described later is also an example of the ball joint structure.

  In addition, the three-axis gimbal mechanism of the handheld video camera stabilization device of the present invention has a separate ball joint structure composed of a ball made of a hard material that is connected to and supported by a grip portion and a receiving tray located at the upper portion and a lower portion. It is preferable that it is comprised.

  In the three-axis gimbal mechanism of the handheld video camera stabilization device of the present invention, the diameter of the ball made of a hard material is preferably 0.2 to 1.6 mm, and more preferably 0.5 to 1. The range is 0 mm.

Further, in the three-axis gimbal mechanism of the handheld video camera stabilization device of the present invention, it is preferable that the gimbal tray part located at the upper part is made of a resin material having a predetermined coefficient of friction or less and has a convex depression.
As a material for the gimbal tray part, a low-friction resin such as Teflon (registered trademark) is preferably used.
Here, the shape of the concave recess on the gimbal tray part is based on a cone, but is not limited thereto. The angle of the cone must be large so that it does not come into contact with the grip part with the gimbal ball fixed at the tip, and if the grip part is tilted or rolled or tilted by unexpected force on the camera, the cone surface will be It is desirable to enlarge the ball so that it does not slip. The angle 33 is usually selected in the range of 5 to 45 degrees.

  In addition, the grip portion under the three-axis gimbal mechanism of the handheld video camera stabilization device of the present invention has a rotation mechanism for manually controlling the pan position of the camera using the friction between the ball of the ball joint and the tray. It is preferable. More preferably, the rotation mechanism includes a device for electric rotation.

  Also, an arm for preventing translation of the photographer's hand in the horizontal plane, which is mounted on the grip portion of the lower part of the three-axis gimbal mechanism of the handheld video camera stabilization device of the present invention, is disposed. Is preferred.

  In addition, it is preferable that the grip portion below the three-axis gimbal mechanism of the handheld video camera stabilization device of the present invention includes a spring device and an impact absorbing device for reducing the vertical position fluctuation of the camera due to walking.

  Further, it is preferable that the grip / lower part of the three-axis gimbal mechanism of the handheld video camera stabilization device of the present invention is provided with a control / operation unit for a mechanism for electrically moving the balance weight of the balance arm / weight mechanism.

  Moreover, it is preferable that the balance arm / weight mechanism of the handheld video camera stabilization device of the present invention is provided with a balance weight electric movement mechanism.

  Further, in the balance arm / weight mechanism of the handheld video camera stabilization apparatus of the present invention, it is preferable that the balance arm / weight mechanism is arranged in the camera posture three-axis direction and includes a manual adjustment mechanism for the balance weight position by screws.

  The balance arm / weight mechanism of the handheld video camera stabilization device of the present invention preferably includes a balance weight that can be manually rotated about the X-axis so that the tilt angle of the camera posture can be changed.

  Moreover, it is preferable to use the electromagnetic force by the balance arm mechanism of the handheld video camera stabilization device of the present invention and the magnet disposed at the lower part of the grip part as a restoring force for stabilizing the video camera.

  Moreover, it is preferable that a gyro ballast is provided in the balance arm / weight mechanism of the handheld video camera stabilization device of the present invention. This is because the gyro ballast can be used to improve the stability of the video camera body.

  According to the handheld video camera stabilization device of the present invention, the balance arm and weight mechanism for attaching the video camera to the video camera and locating its center of gravity at the bottom of the camera, and a minimum diameter (preferably 0.5 to 1.0 mm diameter) Light, simple structure, and low cost to prevent foot vibration from being transmitted to the camera and preventing the image from shaking when shooting footage, such as a video that consists of a three-axis gimbal mechanism made of a low-friction resin tray that is separated from the ball. By providing a simple mechanism, it is possible to perform walk shooting with a hand-held video camera that is becoming increasingly smaller and lighter.

  In addition, video camera control functions such as tilt, pan, and vertical movement are added to the grip part directly connected to the ball of the gimbal mechanism, and camera attitude static and dynamic attitude adjustment functions are added to the balance arm / weight mechanism. The operability that can be controlled only by the grip portion that holds them with one hand can also be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the scope of the present invention is not limited to the illustrated examples.

FIG. 1 shows a schematic configuration diagram of a video camera stabilization apparatus as a basis of the present invention. The components and functions of the handheld video camera stabilization device of the present invention are as follows.
The video camera stabilization device of the present invention includes a video camera body 1, a balance arm / weight mechanism 5 including a balance arm 51 and a balance weight 52, and a mounting screw 2 for connecting the video camera body 1 and the balance arm / weight mechanism 5. And a gimbal tray part 3 and a grip part 4 constituting a three-axis gimbal mechanism.

The grip portion 4 has a gimbal ball fixed to the tip. In addition, a video camera operation switch (not shown) is provided on the side surface of the grip portion 4 so that camera operation control and camera posture control can be performed.

Further, by adjusting the balance arm 51 and the balance weight 52, the position of the center of gravity of the integrated structure of the video camera body 1, the balance arm / weight mechanism 5, the mounting screw 2 and the gimbal tray part 3 constituting the three-axis gimbal mechanism can be adjusted. It can be adjusted arbitrarily.

The video camera main body often has a mounting screw position on the bottom of the main body that does not coincide with the vertical axis of the center of gravity of the camera. However, it is possible to equip them with a quick shoe and a horizontal position adjustment mechanism, which is not a big problem. Conversely, from the viewpoint of the camera stabilization device, the horizontal position adjustment mechanism or the like makes the upper structure to be balanced by the gimbal tray part 3 heavy. As a result, the weight of the balance arm / weight mechanism 5 is increased, which in turn leads to an increase in the weight of the entire system. Therefore, if the balance arm / weight can be easily adjusted, the quick shoe and the horizontal position adjustment mechanism It is better not to install.

The mounting screw position of the bottom portion does not need to coincide with the camera center of gravity vertical axis. By arranging the gimbal tray part 3 directly below the camera center of gravity vertical axis, the balance arm / weight mechanism 5 is set to the camera bottom mounting screw position. The same effect can be obtained by designing so as to correct the deviation of the camera gravity center vertical axis.

As described above, the balance arm / weight mechanism 5 is fixed by the mounting screw 2, and the video camera body 1, the balance arm / weight mechanism 5, the mounting screw 2, and the gimbal tray part 3 constituting the three-axis gimbal mechanism. Any material and any structure can be used as long as it has a function of arbitrarily adjusting the position of the center of gravity of the integrated structure.
In addition, in order to avoid interference with the grip portion 4, a balance weight 52 positioned on the lower side, bypassing the front of the video camera main body 1, and a balance arm 51 structure coupled to the balance weight (reducing weight is desirable as long as strength and rigidity allow) Consists of. The balance weight 52 needs to be provided with a mechanism for adjusting the position manually or electrically in the horizontal and vertical directions by some means.

The mounting screw 2 may be a standard or commercially available 1/4 inch screw.

The gimbal tray part 32 is made of a low-friction resin (Teflon (registered trademark) or the like), and has a concave recess on the top so as to function as a socket for receiving the gimbal bow 31. The lower part may be sufficient, or a part of attachment member of the video camera main body 1 of the balance arm weight mechanism 5 may be sufficient.
However, if the position is as close as possible to the bottom of the camera, the center of the gimbal is brought close to the bottom of the camera, which leads to a reduction in the weight of the balance arm / weight mechanism 5 and thus a reduction in the overall weight of the apparatus.

Further, the shape of the concave recess of the gimbal tray part 32 not only affects the gimbal characteristics, but in the form of the present invention in which the ball 31 and the tray 32 constituting the gimbal are separated, the video camera body 1 Since the integrated structure of the video camera stabilizing device according to the present invention has an important role in preventing the fall from the grip portion 4, sufficient consideration is required. It is possible to prevent the fall by connecting the integrated structure of the grip part 4, the video camera body 1 and the video camera stabilizing device of the present invention with a flexible wire. The shape of the concave depression on the gimbal tray part 32 is basically, but is not limited thereto.

Here, the angle 33 of the concave concave cone needs to be large so as not to come into contact with the grip portion 4 with the gimbal ball fixed to the tip, and the grip portion is tilted or a force is applied to the camera unexpectedly. Therefore, when the roll or tilt is performed, it is desirable to increase the size so that the conical surface does not slide off the ball. Usually selected in the range of 5 to 45 degrees.

Further, it is desirable that the grip portion 4 with the gimbal ball fixed to the tip has a structure in which the ball is exposed as much as possible in order to increase the gimbal operating angle.

In addition, it is a feature of the present invention that the lower part of the grip section has the following functions.
・ Camera function control (REC / STOP and zoom control by infrared of the camera)
・ Initial adjustment of balance arm and weight mechanism (balance weight position adjustment by electric)
-Accurate pan / tilt rotation (manual and motorized) in the desired direction during shooting
・ Spring that absorbs vertical movement and shock absorbing mechanism ・ Camera mitigation mechanism on horizontal surface by arm structure that is externally coupled to the grip and hangs the entire system

A preferred embodiment of the structural function of each part will be described below.
The configuration of the first embodiment shown in FIG. 1 shows the simplest, simplest or lightest configuration example among the components to which various functions can be added. Specifically, a balance weight 52 is attached to the lower part of the U-shaped balance arm 51 so as to be able to translate in the X-axis direction by bolts and nuts and to be rotatable around the Z-axis. The balance arm / weight mechanism 5 in which the balance arm 51 and the balance weight 52 are integrated is fixed to the video camera main body 1 by the mounting screw 2.
In the first embodiment, the gimbal tray part 32 is arranged in a cylindrical space coaxial with the mounting screw 2. By positioning the grip part 4 with the ball 31 at the tip and the grip part support part 42 attached to the lower part of the grip part on the tray 32, the video camera stabilization device is configured.

  Next, FIG. 2 is an enlarged view of the video camera body mounting screw, the gimbal tray part 32, and the grip part 4 with the ball fixed to the tip. FIGS. 3A and 3B show the positional relationship between the center of gravity of these components and the center of the gimbal, that is, the center of the ball constituting the ball joint.

  In the first embodiment, the video camera main body 1, the balance arm / weight mechanism 5 connected to the video camera main body 1, and the mounting screw 2 (including a tray that constitutes a three-axis gimbal) are coupled together, and the center of gravity position thereof is combined. The grip portion 4 is held by inserting the ball 31 attached to the tip of the grip portion into the gimbal tray part 32 by adjusting the balance weight 52 of the balance arm / weight mechanism 5 so that the weight is positioned directly below the center of the gimbal. As a result, the video camera main body 1, the balance arm / weight mechanism 5 and the mounting screw 2 can be stably held together.

The center of gravity of the balance arm / weight mechanism 5 is adjusted by adjusting the length of the balance arm 51 (Z-axis position), fine adjustment of the balance weight 52 in the X-axis position (roll rotation posture adjustment), and fine adjustment around the pan rotation axis (tilt). (Rotational posture adjustment).
By adjusting the length of the balance arm 51, the vertical balance, that is, the restoring force of the Yajirobe pendulum is adjusted. The weight of the balance weight 52, the X-axis position, and the pan rotation can be used for adjusting the initial value of the horizontal balance, that is, the roll and tilt rotation. Although the tilt rotation initial posture is basically horizontal, it is possible to adjust the camera posture looked up or looked down to the initial value by adjusting.

  By adjusting the distance between the center of the gimbal and the center of gravity of the camera-integrated structure to be small, it is possible to prevent the camera from being transmitted to the camera with respect to the roll, pan, and tilt rotations among the shaking of the grip portion caused by the photographer walking. Of the shaking of the grip portion that accompanies the photographer's walk, translational displacements in the X, Y, and Z axis directions are difficult to absorb with this configuration. However, the influence on the image is overwhelmingly larger than the translational displacement, and it is possible to provide a sufficiently practical stabilization device with this configuration alone.

  When the angular velocity of the rotational shake of the grip part 4 accompanying the photographer's walk is slow, or when it continues for a long time even if it is fast, the former is mainly caused by static friction and the latter is caused by dynamic friction. The force is transmitted to the integrated object, which results in rotational displacement of the camera. When displaced, since the center of gravity of the camera integrated object is below the center of gravity of the gimbal, a restoring rotational torque is generated and the tilt is restored. In other words, both the cause of rotation due to disturbance and the restoring force are related to static and dynamic friction of the ball joint. The optimum ball diameter could be limited by systematically experimenting with the influence of the ball diameter on stable hand-held vibration isolation and posture restoration after once rotating.

  FIG. 4 shows a drop test (damped vibration characteristic test) method for evaluating the dynamic behavior and the result of the ball diameter dependency. The video camera used is a Sony HDR-HC3 high-definition camera, which weighs about 600 g (including tape) and the balance arm weight weighs 250 g. As an initial condition of the damped vibration, vibration was measured from a roll angle of 15 degrees, and the attenuation was measured.

When the balance arm / weight center of gravity and the gimbal center-of-gravity distance were constant, that is, as a result of the constant restoring moment, the vibration period increased and the damping increased as the ball diameter increased. Normally, the frictional force is said not to depend on the apparent contact area, but it is considered that the asperity (true contact area) increases as the ball diameter increases. The apparent dynamic friction coefficient changed in a positive correlation with the ball diameter.

By the way, in the drop test under this condition, it was revealed as a result of the actual walk shooting test that the video image shake is the least when the time (defined as τ) crosses the vertical axis for the first time is around 2 seconds. That is, when adjusting to τ = 2 seconds, the restoring weight must be increased by adjusting the balance weight to the bottom heavy as the ball diameter increases and increasing the distance between the balance arm / weight center of gravity and the gimbal center of gravity. Means. This means that when the acceleration of walking vibration (translation in the horizontal plane) is the same, an undesired rotational moment increases as the ball diameter increases. In order to lead to actual rotation, not the dynamic friction but the static friction is involved, and it is not simple, but it is considered that the larger the ball diameter, the more disadvantageous it is for the isolation of walking vibration.

  Further, when the ball diameter is 1.6 mm, the vibration stops in a tilted state. As the ball diameter is larger, the reproducibility of pendulum vibration tends to be lost, which is considered to reflect the uneven distribution of the asperity (true contact area) on the apparent contact surface. It is reported that Steadicam JR, which actually has a ball diameter of more than 5 mm, and Artemis DV of Sahatler, Germany, have an indefinite stop position and frequently need to adjust the vertical balance.

  Next, FIG. 5 shows the ball diameter dependency of the rotational follow-up performance of the integrated object when the grip portion is tilted under the same conditions as the drop test. As the ball diameter increases, a tendency to follow the inclination of the grip portion up to a larger angle is seen. This means that the static friction coefficient apparently has a positive correlation with the ball diameter, and from the viewpoint of the performance of the camera stabilization device, it means that the controllability by the one-hand grip of the roll and pan is increased. In reality, when setting τ = 2 seconds, pan rotation of about 360 degrees is possible in a maximum of 20 seconds. As a pan for normal video shooting, only rotation of the grip, that is, separate from grip support, is possible. It was confirmed that the necessary and sufficient rotational speed could be obtained without touching the camera unit by hand.

FIG. 6 schematically shows the dependence of the camera stabilization device overall performance (dynamic balance characteristics and static controllability) on the ball diameter. The dynamic balance characteristic is the reciprocal of the restoring moment necessary to adjust to τ = 2 seconds, the static controllability is pan and tilt followability, and the product is the camera stabilizer performance (arbitrary unit). The maximum performance is about 0.7 mm, and if it is larger than that, the balance performance becomes unstable, and if it is small, panning, tilting operability, and outdoor shooting are likely to be affected by wind, and the overall performance is degraded.
This revealed for the first time that the allowable range is a ball diameter of 0.2 to 1.6 mm, and the preferred range is a ball diameter of 0.5 to 1 mm.

  Although the above drop test results cannot be quantitatively displayed as an effect in actual video shooting, it has been confirmed that the result is qualitatively consistent with the actual feeling.

A specific configuration example of the balance arm / weight structure will be described with reference to FIG.
FIG. 7A is a configuration example used in the first and second embodiments. The balance arm weight material of the third embodiment is a strip-shaped steel material, but the balance arm portion can be selected from materials and shapes that are light in weight and high in rigidity.
As the length of the balance arm portion is longer, the weight of the balance weight can be reduced. However, the optimum length and material are selected based on the balance with the weight increase of the balance arm itself and the dimensions of the entire system. Graphite reinforced resins, aluminum alloys, etc. are suitable material candidates. A material having a high specific gravity is suitable for the balance weight, and steel, copper alloy, lead, tungsten alloy and the like are candidates.

  FIG. 7B is a configuration example in which a weight capable of rotating the balance arm weight of the first embodiment around the X axis is added. With this configuration, the initial tilt value can be easily changed manually. That is, if the rotatable weight is rotated so that the center of gravity moves forward, it can be set to the initial tilt value directed downward, and conversely, if the weight is rotated so that the center of gravity moves backward, it is directed upward. The initial tilt value can be set. It is the same as the configurations of the first and second embodiments that the walking movement and the pan rotation are possible while maintaining the angle.

  Fig. 7-3 shows that the balance arm weight is composed of bolts and nuts in the X, Y, and Z axis directions, and the nut positions are translated by rotation, so that the position of the center of gravity of the unit can be adjusted independently. In addition, it is possible to make fine adjustments quickly without interfering with each other. The balance weight by this triaxial bolt / nut does not need to be positioned directly under the vertical balance arm as shown in the figure, and it is possible to further reduce the weight of the entire system by decentering it so as to approach the position of the center of gravity. The direction of eccentricity and displacement can be found by static balance calculation or by trial and error based on the relationship between the center of gravity of the mounted camera and the position of the mounting screw.

  FIG. 7-4 is an embodiment provided with a mechanism capable of moving the balance weight with respect to the balance arm in the X, Y, and Z axis directions. It is an electric mechanism, and it is desirable that it can be controlled remotely by a control mechanism arranged in a grip section described later. These movements by remote control can be used at the time of initial balance setting, and can be performed continuously without interruption even when it is desired to change the tilt angle during walking shooting.

  FIG. 7-5 shows an embodiment in which the electric gyro ballast is arranged on the balance arm below the balance arm. In addition to passive posture restoration by the gimbal, active posture stability can be added, and more stable posture control becomes possible. In addition, the passive posture restoring force by the gimbal can be adjusted to be smaller, so that stable shooting can be performed even when shooting under acceleration, for example, acceleration or deceleration of a vehicle such as a car or an airplane.

  FIG. 7-6 shows a configuration example that can achieve the most weight reduction. The position of the center of gravity can be adjusted by a combination of rotation around the pan axis of the balance weight composed of bolts and nuts and translational displacement in the horizontal plane by adjusting the nut position.

FIGS. 8A and 8B are configuration examples of a camera stabilization device for stereo video shooting using two cameras. All of them are characterized by using the camera's own weight as a balance weight. A configuration that does not use a balance weight at all is also possible, making it possible to reduce weight and size. With this configuration, by replacing one camera with a balance weight, it can be used as a normal camera stabilization device for one camera.
In addition, even with a single camera, by providing a space that can be fitted with a gimbal mechanism and grip mechanism near the center of gravity and connected to the outside in advance, the ultimate lightweight camera stabilization that uses its own weight as a balance weight An apparatus can be realized. In particular, this configuration can be applied to a digital camera that has been generally equipped with a moving image function in recent years.

FIGS. 9-1 to 9-4 show examples relating to the structure, configuration, and function of the grip portion.
FIG. 9-1 shows an additional embodiment of the active restoring force constituted by a pair of magnets fixed to the balance arm directly below the magnet at the bottom of the grip. The magnet may be an electromagnet or a permanent magnet, but a permanent magnet is desirable because no power supply is required. The configuration of the magnetic poles is preferably a combination that attracts each other. With this configuration, not only passive posture restoration by the gimbal but also active posture stability can be added, and more stable posture control becomes possible. In addition, the passive posture restoring force by the gimbal can be adjusted to be smaller, so that stable shooting can be performed even when shooting under acceleration, for example, acceleration or deceleration of a vehicle such as a car or an airplane.

  FIG. 9-2 shows an additional embodiment of a U-shaped holding fitting fixedly connected to the lower part of the grip. With this configuration, an undesired translational movement in the horizontal direction (X, Y plane) of the hand that supports the camera during moving shooting is converted and transmitted as a rotational movement with respect to the center of the gimbal. The camera system can be stabilized against no translational vibration. The camera posture can be controlled in the same manner as the grip. Another advantage of this configuration is that it can be used conveniently for low-angle shooting.

  FIG. 9-3 shows an embodiment in which functions are added to the grip portion. The grip part 41 is developed into a rotatable upper part 47 and a grip part 48 held by hand. The grip portion 48 incorporates an electric motor capable of rotating in the forward and reverse directions, and the rotating shaft is directly connected to the grip upper portion 47. The motor rotation is transmitted to the gimbal ball 31 fixed to the grip upper part 413, and the camera can be pan-rotated by the friction of the gimbal. This enables electric pan control in addition to manual pan control. The manual pan control can be rotated 360 degrees, but the photographer's own rotation is auxiliary. In reality, the balance arm 51 may be in contact with the hand supporting the grip within the range of rotation of the pan. However, this electric pan rotation eliminates the restriction. In addition, when the wind is strong, when moving quickly, a pan rotation moment may occur, but this can be canceled out. By placing a resistive plate made of lightweight material so that the two-dimensional silhouette of the camera and camera stabilization device vertically projected can be balanced left and right and up and down with respect to the vertical axis of the 3-axis gimbal, Balance instability caused by wind can be reduced.

FIG. 9-4 shows another embodiment in which functions are added to the grip portion.
Of the undesired vibrations associated with the photographer's walk, rotation to the camera can be isolated by a gimbal mechanism, and specific methods have been disclosed in various embodiments. Regarding translational vibration, the possibility of isolation can be shown in FIG. 9-2. The remaining vibration is related to vertical (Z-axis) translation. As shown in FIG. 9-4, the grip part 41 is developed into an upper part 411 that can move up and down and a grip part 412 that is held by hand. A spring 43 is disposed directly below the upper portion 411 and supports the total weight of the camera, the balance arm and the weight integrated. The photographer's vertical movement is transmitted to the grip lower portions 442 and 412, but the vibration is absorbed by the spring 43 to the grip lower portion 411, and the vibration can be slightly isolated from the camera.

  However, the damping vibration is slow only with the spring, and the undesirable vertical movement continues. The shock absorber disposed at 44 absorbs this. Regardless of the type of shock absorber, a normal oil damper type material can be used, and a material having a shock absorbing function such as urethane gel can also be used. Although the normal human walking cycle is less than 1 second, it is possible to realize effective shock absorption characteristics at that frequency by known mechanical studies.

  INDUSTRIAL APPLICABILITY The handheld video camera stabilization device of the present invention can be used for an apparatus used when moving shooting is performed with a movie camera such as a video camera or a digital camera with a moving image shooting function.

Schematic configuration diagram of a handheld video camera stabilization device Enlarged view of the camera mounting screw, gimbal pan, and grip with the ball fixed to the tip Positional relationship diagram of the center of gravity of each component and the center of the gimbal 1 Positional relationship diagram of center of gravity of each component and gimbal center 2 A graph showing the results of a drop test method (damping vibration characteristic test using dynamic friction) and ball diameter dependence to evaluate dynamic behavior Graph showing the ball diameter dependence of the rotation follow-up performance of the camera, balance arm and weight integrated when the grip is tilted A graph showing the ball diameter dependence of the overall performance (dynamic balance characteristics and static controllability) of the camera stabilization device Balance arm weight configuration example 1 Balance arm weight configuration example 2 Balance arm weight configuration example 3 Balance arm weight configuration example 4 Balance arm weight configuration example 5 Balance arm weight configuration example 6 Configuration example of a camera stabilization device for stereo video shooting with two cameras Grip part configuration example 1 Grip part configuration example 2 Grip configuration example 3 Grip part configuration example 4

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Video camera body 13 Monitor 2 Mounting screw 3 Gimbal mechanism (comprising gimbal ball 31 and gimbal tray 32)
31 Gimbal Ball 32 Gimbal Plate Part 33 Gimbal Plate Angle 34 Gimbal Center 35 Camera Center of Gravity 36 Center of Gravity of Camera / Balance Arm / Weight Integrated 37 Center of Gravity of Balance Arm / Weight Integrated 38 Restored Pendulum Length (Distance between 35 and 36)
4 Overall grip part 41 Upper part of the grip for fixing the gimbal ball to the tip 411 Upper part of the grip (movable up and down)
412 Lower grip (built-in spring 43 and shock absorbing member 44)
413 Grip upper part (possible to rotate around Z axis)
414 Lower grip (built-in spring 43 and shock absorbing member 44)
42 Lower manual grip grip 43 Spring 44 Shock absorbing member 45 U-shaped grip holding bracket 46 Camera operation switch REC / STOP, etc.)
47 Camera operation switches (zoom, etc.)
48 Balance weight movement switch 49 Forward / reverse electric motor 5 Balance arm / balance weight integrated body 51 Balance arm 52 Balance weight 53 Balance arm / balance weight fixing bracket 54 Electric gyro ballast

Claims (16)

1) A balance arm / weight mechanism attached to the main body of the video camera (including a digital camera with a moving image function);
2) A grip portion for supporting the video camera body and the balance arm / weight mechanism by hand;
3) A three-axis gimbal mechanism that is located above the grip portion and coupled to the balance arm / weight mechanism or the video camera body;
A device for stabilizing a video camera for handheld, comprising:   The handheld video camera stabilization device, wherein a balance weight in the balance arm / weight mechanism includes a second video camera main body itself different from the video camera main body.   3. The handheld video camera stabilization device according to claim 1, wherein the three-axis gimbal mechanism is configured by a ball joint structure.   The three-axis gimbal mechanism is a ball joint structure composed of a saucer located at the upper part and a ball made of a hard material located at the lower part, and is supported by a grip part having the ball as a vertex. The handheld video camera stabilization device according to claim 1 or 2.   5. The handheld video camera stabilization device according to claim 4, wherein the diameter of the ball made of a hard material in the triaxial gimbal mechanism is 0.2 to 1.6 mm.   6. The device according to claim 3, wherein, in the three-axis gimbal mechanism, the saucer located at an upper portion is made of a material having a predetermined coefficient of friction or less and has a convex recess. Handheld video camera stabilization device.   4. A rotating mechanism for manually controlling a pan position of a camera using friction between the ball of the ball joint and the tray in the grip portion below the three-axis gimbal mechanism. 7. The handheld video camera stabilization device according to any one of claims 6 to 6.   8. The handheld video camera stabilization device according to claim 7, wherein the rotation mechanism includes a device for electric rotation.   8. The arm according to claim 1, further comprising: an arm that is attached to the grip portion at a lower part of the three-axis gimbal mechanism and that does not transmit translational swing in a horizontal plane of a photographer's hand holding the grip portion. The handheld video camera stabilization device according to any one of the preceding claims.   8. The apparatus according to claim 1, wherein a spring device and an impact absorbing device are provided in the grip portion below the three-axis gimbal mechanism to reduce the vertical position fluctuation of the camera due to walking. A handheld video camera stabilization device as described.   8. The control / operation part of a mechanism for electrically moving a balance weight of the balance arm / weight mechanism is provided in the grip part below the three-axis gimbal mechanism. An apparatus for stabilizing a video camera for handheld according to the item.   8. The handheld video camera stabilization device according to claim 1, wherein the balance arm / weight mechanism includes a balance weight electric movement mechanism.   8. The handheld device according to claim 1, wherein the balance arm / weight mechanism includes a manual adjustment mechanism for adjusting a balance weight position by a screw, which is arranged in three camera postures. Video camera stabilization device.   8. The balance arm / weight mechanism according to claim 1, further comprising a balance weight that can change a tilt angle of a camera posture and can be manually rotated around the X axis. Handheld video camera stabilization device.   The handheld device according to any one of claims 1 to 7, wherein an electromagnetic force generated by the balance arm / weight mechanism and a magnet disposed under the grip portion is used as a restoring force for stabilizing the video camera. Video camera stabilization device. 8. The handheld video camera stabilization device according to claim 1, wherein a gyro ballast is disposed in the balance arm / weight mechanism.