GB2521865A

GB2521865A - Camera stabilisation mounting

Info

Publication number: GB2521865A
Application number: GB1400186.1A
Authority: GB
Inventors: Kin Leung
Original assignee: MASTORTECH Ltd
Current assignee: MASTORTECH Ltd
Priority date: 2014-01-07
Filing date: 2014-01-07
Publication date: 2015-07-08
Also published as: GB201400186D0

Abstract

Camera platform 18 assembly 10 for single handed use having support arm 11 mounted to platform 18 to provide relative movement / rotation in pitch / tilt and roll axes 17, 13. Movement may be effected by pitch and roll motors 22, 21, co-axial with axes 17, 13. Motors 22, 21 may have rotatable armatures, and may be connected by L-shaped bracket 14. Axes 17, 13 may coincide. Support arm 11 may be handgrip extending on yaw axis (figure 5, 27) orthogonal to pitch and roll axes 17, 13 and intersecting platform 18. Handgrip 11 may be pistol grip with thumb actuated pitch control switch (figure 5, 23, 24) and forefinger operated on / off switch 26. Pitch and roll may be controlled by orientation sensor comprising solid state electronic gyroscope. For use with video camera, still camera, smart phone, tablet computer. A method of use is also included.

Description

Camera Stabilisation Mounting

TECHNICAL FIELD

This invention relates to a stabilisation mounting for a camera, particularly a video camera, which is capable of being hand-held, and capable of maintaining a horizontal viewing plane.

BACKGROUND TO THE INVENTION

One problem with hand-held cameras is the effect of vibration and movement on the viewing direction. Typically a hand-held camera is subject to instability because of the difficulty of holding the camera still. A moving camera, for example a vehicle mounted camera, is subject to instability due to movement of the vehicle out of the viewing plane. A hand-held camera on a moving vehicle suffers both forms of instability, and this instability is exacerbated in a video image. Moving the camera, for example in a video panning shot, tends to emphasize instabilities.

U.S. patent 8,179,078 contains an extensive review of prior art camera stabilisation techniques, and discloses a camera stabilisation platform with rotation sensors for the pitch and yaw (pan) axes. The platform is adapted to a particular camera device.

This prior device principally relies upon two handholds to control movement in the roll axis, and has pitch and yaw sensors, placed respectively on the pitch and yaw axes, to provide a control signal for pitch and yaw motors, whereby a camera on the mount is stabilised, See-saw type automatic roll control is also disclosed in the prior art, but has certain control and displacement limitations by virtue of the frame-like design of the prior stabilisation platform.

What is required is an improved camera platform capable of maintaining a horizontal viewing plane with simplicity of construction and comparatively light weight.

SUMv1ARY OF THE INVENTION According to one aspect of the invention there is provided a platform assembly for a camera, said assembly being adapted for single handholding and comprising a camera platform for supporting a camera thereon, and a support arm, said platform being mounted to said support arm with capability of relative movement in pitch and roll about respective pitch and roll axes, and wherein said roll capability comprises rotation Unlike the prior art the assembly of the invention is capable of maintaining the camera platform in a horizontal plane, thus avoiding the disturbances which are often apparent in a hand-held camera, particularly during panning.

In one embodiment the assembly includes an electronic orientation sensor in or on the camera platform for detecting angular movement in pitch and roll, and a pitch motor and roll motor for effecting correcting motion to the platform.

The assembly is in one embodiment self-contained, and comprises batteries or the like to provide electrical energy to the orientation sensor and motors.

In one embodiment the assembly is held in one hand via a substantially vertically orientated pistol grip, and can be panned by movement of the user's arm. In this condition of use, the centre of gravity of the assembly may be arranged to substantially coincide with a vertical (panning) axis of the assembly. This arrangement both reduces strain on the user's arm in applying a correcting torque to the pistol grip, and also minimizes the electrical consumption of the pitch and roll motors.

The generally vertical axis of the pistol grip may pass between a camera on the assembly and a roll motor mounted on the pistol grip, and for this purpose the pistol grip may include a rearwardly cranked extension.

In a second aspect the invention provides a method of providing positioning of a hand-held camera in a horizontal plane, said method comprising mounting a camera on a platform assembly according to the invention, holding said assembly via the support arm in a single hand, and stabilising said camera by motorised movement of the camera platform in pitch and roll under control of an orientation sensor for the camera platform.

BRIEF DESCRIPTION OF DRAWINGS

Other features of the invention will be apparent from the appended claims and from the following description of an embodiment shown by way of example only in the accompanying drawings in which:-Fig. I is a perspective view of a mounting according to the invention carried in one hand and having a camera mounted thereon; Fig. 2 is a plan view of the mounting and camera of Fig. 1; t5 Fig. 3 is a front elevation of the monnting and camera of Fig. t; Fig. 4 isa side elevation of the mounting and camera of Fig. 1; Fig. 5 is a rear elevation of the mounting and camera of Fig. t.

Fig. 6 is a schematic front elevation showing rotatability of the camera mounting about the roll axis, Fig. 7 shows the mounting of Fig. 6 with smart phone in landscape orientation.

Fig. 8 shows the mounting of Fig. 6 with tablet mounted thereon.

DESCRIPTION OF AN EMBODIMENT

With reference to Figs. 1-5, a hand-held camera mount 10 comprises a single handgrip II which is cranked upwardly and backwardly to define a generally upright planar support 12 which defines orthogonally thereto a generally horizontal roll axis H, An U shaped frame member 14 has one leg 15 pivotable about the roll axis 13, and another leg 16 which defines orthogonally thereto a generafly horizontal pitch axis 17.

A camera platform 18 is pivotable about the pitch axis 17, and supports a removable camera 19, for example a digital SLR camera.

It Will be understood that the roll and pitch axes 13, 17 may be used to maintain the direction of view 20 of the camera in a substantially horizontal plane, notwithstanding relative movements of the handgrip 11, as will be further explained below.

The leg 15 is mounted with respect to the support 12 via a roll motor 21, and the platform 18 is mounted with respect to the leg 16 via a pitch motor 22 Thus it will be understood that arcuate movement of the respective motor TI, 22 will result in corresponding movement of the camera platform 18 in roll and pitch.

The handgrip ii is generally configured as a trigger grip whereby the palm and fingers provide the gripping force and the thumb is capable of independent movement.

In the illustrated embodiment thumb switches 23, 24 are provided for manual control movement of the camera platform about the pitch axis 17, one switch 23 pitching the platform 18 downward when pressed, and the other switch 24 pitching the mount 18 upward when pressed. Other kinds of switch, for example a rocker or wheel switch, are possible. A power on-off switch 26 is conveniently located at the front of the handgrip for operation by a forefinger. Other switches may be provided for manual control of roll, if desired, for example to create special effects.

The camera platform 18 includes a support casing 25 within which is mounted a solid state orientation sensor of conventional kind such as a vibrating structure gyroscope.

Such a sensor is capable of determining absolutely the orientation of the platform 18, and is further capable of giving corrective electronic signals to the motors 21, 22 so as to automatically maintain a horizontal viewing direction for the camera.

Panning of the camera (rotation about a generally vertical yaw axis) can be achieved by arcuate movement of the hand, and the orientation sensor is used to automatically correct any tilting of the camera platform about the roll and pitch axes 13, 17.

An important attribute of the invention is that the handgrip 11 is fufly rotatable about the roll axis 13. Thus the orientation of the handgrip in the vertical plane is not restricted, and the handgrip 11 may be below the platform 18 (as illustrated), or above the platform, or to one side of the platform. Furthermore, the handgrip 11 may be moved arcuately with respect to the camera mount, without restriction, should the holder of the handgrip wish to do so. This aspect of the invention is illustrated schematically in Fig. 6, and shows alternative handle positions at 900, ]Q0 and 2700 about the roll axis. Any intermediate handle position is obtainable whilst maintaining the camera platform 18 substantially horizontal.

The embodiment of Figs. 1-5, unlike the prior art, is capable of being held in one hand, and may be made of lightweight materials such as plastic and aluminium.

Batteries for electrical power may be housed within the handgrip 11. Rearward t5 cranking of the handgrip ensures that the centre of gravity is generally above the vertical gripping axis 27, so that the user need not have to exert an arcuate force in order to maintain the handgrip in a substantially vertical orientation, neither rolling to one side nor pitching forward or backward. The roll axis 13 is arranged to pass close to the centre of the mass movable about the roll axis (camera, camera mount, pitch motor and frame member), and the pitch axis 17 is also arranged to pass close to the centre of the mass movable about the pitch axis (camera and camera mount).

The relatively simple L' shaped frame member provides the necessary axes of movement in roll and pitch, yet is small and thus of low mass and low cost.

Furthermore such a bracket may be easily sized to suit the dimensions of the camera to be mounted, whilst maintaining the centre of mass substantially on the vertical gripping axis 27. For example either leg 15, 16 may be made longer or shorter (see K and Y' of Fig. 2), and the rearwards cranking of the handgrip may be increased or decreased (see Z' of Fig. 4), according to requirements of design and balance.

In a practical embodiment, the motors 21, 22 are brushless D.C. motors having a rotational positional accuracy of + 0.05 degrees, and a corrective speed of + 180

S

degrees per second. The solid state gyroscope may employ a 32 bit microcomputer, and the camera mount may have a working current in the range 150-200 mA.

In use it is envisaged that initialisation after switching on will take 15 seconds or less.

Within this period the camera platform 18 will stabilise in the horizontal plane, according to detection of movement inputs at the handgrip 11, The speed and direction of movement in translation and rotation are sensed by the solid state gyroscope, and using conventional predictive, differentiation and integration techniques, the motors 21, 22 are energised to maintain the platform horizontal.

Typically one or more PID controllers are utilised to ensure that each motor rapidly reaches a desired rotational position.

As noted above Fig. 6 illustrates the possibility of moving the handle 11 angularly about the roll axis to any desired orientation, thus increasing the possibilities of supporting the camera in confined locations, whilst maintaining freedom from roll induced camera shake.

Fig. 6 shows a smart phone in portrait orientation, and secured by a standard screw mount 28; other kinds of mount are of course possible, including slides, rails, forks and clamps.

Fig. 7 illustrates a smart phone in landscape orientation, and in Fig. 8 a tablet computer is illustrated to emphasize the versatility of the invention. Unlike the prior art, the mounting of the invention is suitable for a wide range of recording devices, including camcorders arid conventional mobile phones, and is thus not restricted to a particular recording device.

Amendments and alterations to the invention are of course envisaged within the scope of the claims appended hereto.

Claims

Claims I. A platform assembly for a camera, said assembly being adapted for single handholding and comprising a camera platform for supporting a camera thereon, and a support arm, said platform being mounted to said support arm with capability of relative movement in pitch and roll about respective pitch and roll axes, and wherein said roll capability comprises rotation.
2. An assembly according to claim 1 and further including a pitch motor and a roll motor, whereby said relative movement is effected.
3. An assembly according to claim 2 wherein said pitch motor is co-axial with the pitch axis.tS
4. An assembly according to claim 2 or claim 3 wherein said roll motor is coaxial with the roll axis.
5. An assembly according to claim 4 wherein said roll motor comprises a roll motor body mounted on said support arm, and a rotatable roll motor armature,
6. An assembly according to claim S and including a bracket connected to said roll motor armature at one end, the other end of said bracket having said pitch motor mounted thereon.
7. An assembly according to claim 6 wherein said pitch motor comprises a pitch motor body mounted to said bracket, and a rotatable pitch motor armature connected to said platform.
8. An assembly according to claim 6 or claim 7 wherein said bracket is substantially L' shaped, the pitch axis passing through one arm thereof, and the roll axis passing through the other arm thereof
9. An assembly according to any preceding claim wherein the pitch and roll axes coincide.
10. An assembly according to any preceding claim wherein said support arm comprises a handgrip.
11. An assembly according to claim 10 wherein in one orientation said support arm extends on a yaw axis substantially orthogonally to said pitch and roll axes.
12. An assembly according to claim 11 wherein said yaw axis intersects said platform.
13. An assembly according to claim 11 or claim 12 wherein said yaw and roll axes coincide.
14. An assembly according to any of claims 10-13 wherein said handgrip is a pistol grip having thumb actuated pitch control for a pitch motor.
15. An assembly according to claim 14 and further including a pitch-up thumb switch and a pitch-down thumb switch.
16. An assembly according to any of claims 10-15 and including a forefinger actuated on/off switch.
17. An assembly according to any preceding claim and further including an orientation sensor for said camera platform whereby relative pitch and roll is controlled.
18. An assembly according to claim 17 wherein said sensor is contained within said platform.
19. An assembly according to claim 17 or claim 18 wherein said sensor comprises a solid state electronic gyroscope.
20. An assembly according to any preceding claim wherein said camera platform is adapted to receive one of a still camera, a video camera, a combined still and video camera, and a computer device incorporating a camera.
21. An assembly according to claim 20 wherein said camera is one of a smart phone and a tablet computer.
22. A method of providing positioning of a hand-held camera in a horizontal plane, said method comprising: mounting said camera on a platform assembly according to any of claims 17- 19, holding said assembly via said support arm in a single hand, and stabilising said camera by motorised movement of said camera platform in pitch and roll under control of said orientation sensor.
23. A platform assembly for a camera, substantially as described herein with reference to the accompanying drawings.
24. A method of positioning a hand-held camera in a horizontal plane, substantially as described herein with reference to the accompanying drawings.