WO2006117568A1

WO2006117568A1 - Improvements in or relating to camera mountings

Info

Publication number: WO2006117568A1
Application number: PCT/GB2006/001639
Authority: WO
Inventors: Richard Arthur Lindsay
Original assignee: The Vitec Group Plc
Priority date: 2005-05-05
Filing date: 2006-05-05
Publication date: 2006-11-09
Also published as: GB0509233D0; GB2426074A

Abstract

A TV/video camera (12) is disclosed in which optical images are converted into electronic signals. A motorised mounting (10,14,15,16,17) moves the camera in pan and tilt axes and a remote control (18,19) for the motorised mounting provides input signals to the mounting to command movements of the camera in said axes. The camera/mounting has an electronic gyroscope (29) for determining actual movement of the camera/mounting in said axes to provide signals corresponding to actual movement of the camera, and the camera has a microprocessor (28) connected to the gyroscope (29) and remote control (18,19) to receive signals corresponding to intended and actual movements of the camera to determine the difference which corresponds to unwanted movement of the camera and to correct the image via an input (32) to the camera to eliminate the unwanted movement from the image.

Description

IMPROVEMENTS IN OR RELATING TO CAMERA MOUNTINGS

This invention relates to camera mountings and in particular to TV or video camera mountings on which a camera is supported for pan and tilt movement and may be also about a third, roll axis extending parallel to the camera lens axis .

Modern pan and tilt movements incorporate refined bearing arrangements which permit this pan and tilt movement of the camera and refined clamping systems to enable the camera operator to move the camera as smoothly as possible. Any slight jerkiness in the movement is inevitably apparent in the image which is subsequently viewed usually by a television.

Whilst a skilled camera man can exercise great caution in moving the camera to avoid inputting any vibration or jerkiness into its movement, it is inevitable that other forces can act on the camera causing unwanted movements.

For example vibration or movement through the ground or base on which the camera is supported reaches the camera through the mounting and may affect the image recorded by the camera. Other external forces such as wind force exerted on the camera can also cause unwanted camera movement.

Our International patent publication number WO 00/39498 addresses these problems and discloses a mounting for an optical apparatus having an optical axis, the mounting having non-moving and moving components including a base and support for the optical apparatus which provides movement about one or more orthogonal axes (e.g. in pan and tilt) and having damping means between the moving and non-moving components for the or each axis. Means are provided for movement of the support in the or each axis by a gyroscope or equivalent device and the difference between the actual and the intended movements is the determined and used to apply correction to the support/apparatus to counter the unintended movements. The mounting plate for the camera is a two part plate with motorised devices between the parts for adjusting the parts with respect to one another in the pan and tilt axes of the camera and the unwanted movement of the camera determined as indicated above is used to operate a control system for the motorised device to adjust the mounting tapered for the camera to counter the unwanted movement. As an alternative to adjusting a mounting plate, the correction signal could be applied to the camera optics or to the image recorded by the camera rather than the mechanical movement of the camera itself.

This invention provides a TV/video camera having means to convert optical images into electronic signals, a motorised mounting for movement of the camera in at least one axis and a remote control for the motorised mounting for providing input signals to the mounting to command movements of the camera in said axis or axes, the camera/mounting having gyroscope means for determining actual movement of the camera/mounting in the or each axis providing a signal corresponding to actual movement of the camera and having processing means connected to the gyroscope means and remote control to receive signals corresponding to intended and actual movements of the camera to determine the difference which corresponds to unwanted movement of the camera and for correcting the image in the camera to eliminate the unwanted movement from the image. More specifically the mounting for the camera may provide motorised movement in the pan and tilt axes of the camera and the remote control controls movement of the camera in said pan and tilt axes, the remote controller providing signals for said.pan and tilt axes indicating intended movement of the camera to said image correction means and the gyroscope means measuring actual movement of the camera/mounting in said pan and tilt axes and providing signals to the image correction means whereby unwanted camera movement in each axis is determined and the resulting signals used to correct the image in the camera.

In one particular arrangement according to the . invention the camera optics may be adjustably mounted for movement of the optical axis with respect to the image receiving system, and means are provided for adjusting the optics in response to said control means to eliminate said unwanted movement in the image.

In a further arrangement the image receiving system on which an image is focussed by the camera optics for conversion from an optical image into electronic image data may have a greater area than the area of the actual image and means are provided for adjusting the position of the required area on the receiving system to compensate for said unwanted movement of the camera. In the latter arrangement the camera may be a video camera and the receiving system comprises a CCD array, the actual image being taken from an area of predetermined size and said means responsive to the correction signal are arranged to move the area in response to the correction signal to compensate for unwanted camera movement. In a still further arrangement means may be provided for recording the electronic image data and correction signals for subsequent correction of the image.

In any of the above arrangements the remote control for the camera mounting motorised drives may comprise a joystick mounted for movement in orthogonal planes, movement of the joystick in one plane controlling pan movement of the camera and on the other plane controlling tilt movement of the camera mounting.

The following is a description of some specific embodiments of the invention, reference being made to the accompanying drawings in which:

Figure 1 is a diagrammatic side view of a TV/video camera supported on a mounting having motorised drives for pan and tilt movement and a remote joystick for controlling the pan and tilt movement and one arrangement for correcting the camera for unwanted movement;

Figures 2 and 3 are diagrammatic views internally of a video camera showing two different ways of compensating for unwanted movement;

Figure 4 is a similar view to Figure 1 showing an arrangement for correcting in the camera lens system for unwanted movement; Figure 5 is a similar view to Figure 1 in which the correction of the image recorded by the camera is carried out in a microprocessor outside the camera.

Referring to the drawings, there is shown a pan and tilt mounting indicated generally at 10 for location on a tripod or pedestal (not shown) and having a mounting plate 11 on which a TV or video camera 12 is supported. The camera has a lens assembly indicated at 13. The camera mounting 10 comprises a lower mounting 14 which provides pan movement about a vertical axis for the camera and an upper mounting 15 which provides tilt movement about a horizontal axis for the camera. The lower mounting 14 incorporates a motorised drive 16 for pan movement of the camera, and the upper mounting 15 incorporates a motorised drive 17 for tilt movement of the camera.

The motorised drives are controlled by a remote controller 18 having a joystick 19. The joystick is movable in a fore and aft plane 20 which is arranged to control tilt movement of the mounting and in a side to side 21 plane to control pan movement of the mounting. The controller is connected by a line 22 to an interface 23 having lines 24 and 25 connected to the motorised units 16 and 17 for pan and tilt movement of the camera mounting in accordance with command signals from the joystick controller.

Joystick movement represents intended movement of the camera and the interface 23 has lines 26 and 27 to duplicate the command signals to the motorised pan and tilt heads to a microprocessor 28. Actual movement of the camera is monitored by a 2 -axis electronic gyroscope 29 located on the support plate 11 for the camera or the camera itself.

The actual movement of the camera includes unwanted movements imparted to the camera from the ground on which the camera is supported or other external forces acting on the camera such as wind force where the camera is used in outside broadcast location or unwanted vibration imparted to the camera by the operator. The gyroscope 29 has output lines 30,31 leading to the microprocessor 28 for signals corresponding to actual pan and tilt movement. The microprocessor is programed to determine the difference between the intended movement of the camera corresponding to the joystick movement and the actual movement of the camera as determined by the gyroscope. The differences between the two in the respective axes of movement (i.e. pan and tilt of the camera) represents the unwanted movements i.e. the corrections required to the camera in the respective axes.

Signals from the micro-processor representing the correction to the camera required are passed by an input line 32 to the camera control system for correction of the image in the camera. Figure 2 of the drawings is a diagrammatic illustration of a CCD array 33 in the camera which is used.to generate an electronic image of the scene in front of the camera. The frame of the optical image incident on the CCD array is indicated at 34 and is within the boundaries of the array. In one arrangement according to the invention, the array is mounted in the camera for movement in the plane 35 of the array and an arrangement of actuators 31 is provided for displacing the array in any direction within the plane. A control system (not shown) for the actuators receives correction signals from the microprocessor 28 and moves the array accordingly to compensate for unwanted movement of the camera so that that movement is eliminated from the image recorded by the CCD array. The resulting corrected image is delivered by an output for recordal/broadcasting. In an alternative arrangement shown in Figure 3 a control system 36 is provided for controlling the position of the frame 34 on the array from which the electronic image is taken. The correction signal from the microprocessor 28 referred to earlier is fed to the control system 31 to adjust the position of the frame 34 to compensate for unwanted movement of the camera. In a modification of the above apparatus the camera mounting has motorised movement about a roll axis extending parallel to the camera optical axis. The remote controller is arranged to the movement of the camera in said axis. Reference is now made to the further embodiment illustrated in Figure 4 of the drawings. In this case the camera lens system has a control for adjusting the axi^'s of the lens system to compensate for said unwanted movement . The correction signal is fed from the micro-processor 28 by a connection 38 as illustrated to the lens system to feed the correction signal to the lens system. The arrangement is otherwise the same as that of Figure 1.

The invention also envisages correcting the image externally of the camera as shown in Figure 5. In this case the uncorrected electronic image from the camera is fed by a line 39 to the microprocessor 28 together with the inputs from the pan and tilt encoders and the two axis gyroscope as before. The processor is programed to correct the electronic image from the camera to eliminate the effect of unwanted movement from the recorded image and to produce a corrected signal which is output from the microprocessor at 28 for broadcast/recordal .

In yet a further arrangement a device is provided for recording the camera image and a second device is provided for recording, in synchronism with the image, the signals from the encoders and electronic gyroscope. The recording devices have outputs which are fed when a corrected image is to be produced to a remote processor in which the image from the camera is corrected in accordance with the correction signal produced by the gyroscope and encoders and the resulting signal is output for broadcast or recordal. It will be appreciated that many modifications may be made to the above embodiments without departing from the scope of the invention. For example other forms of manual remote controls may be used instead of a joystick such as rotary control knobs and the like. In a further arrangement a computer based control system may be used which may have a pre-programmed graphical user interface.

Claims

CLAIMS :

1. A TV/video camera having means to convert optical images into electronic signals, a motorised mounting for movement of the camera in at least one axis and a remote control for the motorised mounting for providing input signals to the mounting to command movements of the camera in said axis or axes, the camera/mounting has gyroscope means for determining actual movement of the camera/mounting in the or each axis providing a signal corresponding to actual movement of the camera, and the camera has processing means connected to the gyroscope means and remote control to receive signals corresponding to intended and actual movements of the camera to determine the difference which corresponds to unwanted movement of the camera and for correcting the image in the camera to eliminate the unwanted movement from the image .

2. A camera as claimed in claim 1, wherein the mounting for the camera provides motorised movement in one or more of pan, tilt and roll axes of the camera and the remote control controls movement of the camera in the or each axis, the remote controller providing signals for intended movement of the camera to said image correction means and the gyroscope means measuring actual movement of the camera/mounting in said axes and providing signals to the image correction means whereby unwanted camera movement in the or each axis is determined and the resulting signals used to correct the image in the camera.

3. A camera as claimed in claim 2, wherein the camera mounting provides motorised pan and tilt movement for the camera and the remote controller controls movement in the pan and tilt directions.

4. A camera as claimed in any of claims 1 to 3 , wherein the camera optics are adjustably mounted for movement of the optical axis with respect to the image receiving system, and means are provided for adjusting the optics in response to said control means to eliminate said unwanted movement in the image.

5. A camera as claimed in any of claims 1 to 3, wherein the image receiving system on which an image is focussed by the camera optics for conversion from an optical image into electronic image data has a greater area than the area of the actual image and means are provided for adjusting the position of the required area on the receiving system to compensate for said unwanted movement of the camera.

6. A camera as claimed in claim 5, wherein the camera is a video camera and the receiving system comprises a CCD array, the actual image being taken from an area of predetermined size and said means responsive to the correction signal are arranged to move the area in response. to the correction signal to compensate for unwanted camera movement.

7. A camera as claimed in any of claims 1 to 3, wherein means are provided for recording the electronic image data image and correction signals for subsequent correction of the image .

8. A camera as claimed in any of the preceding claims, wherein the remote control for the camera mounting motorised drives comprises a joystick mounted for movement in orthogonal planes, movement of the joystick in one plane controlling pan movement of the camera and on the other plane controlling tilt movement of the camera mounting.