GB2145235A - Underwater imaging - Google Patents

Abstract

An underwater imaging system with remote viewing comprises a camera, light source, fibre optic cable for optically connecting the subject being imaged with the camera and light source, and one or more water-tight housings. The camera may be TV, cine or still. As shown, a water-tight housing 1 contains a light source 2, SLR camera 10, TV camera 13 for viewing through the SLR camera lens, fibre optic cables 5 and 7, controller 8 for moving cable 7, and bundle of electrical cables 4. Housing 1 has a seal 16 for cables 4 and seal 17 for cable 7. Cable 5 may pass through seal 17 or a separate seal. TV and still cameras may be provided in parallel (Figure 2). A TV camera may be provided without a SLR camera (Figures 4 and 5) and, if of underwater type, may be situated outside a separate water-tight housing (Figures 3 and 5). Two separate water-tight housings may be provided (Figures 3 and 5). <IMAGE>

Description

SPECIFICATION Imaging system This invention relates to an imaging system.

Viewing an object underwater has hitherto involved directing a camera at the object and transmitting the image obtained to the surface or to some other location for viewing. This has been generally satisfactory in providing general views of the object but has been constrained by the size of the camera to prevent fine detail or inspection within tight spaces being achieved.

According to the present invention there is provided an underwater imaging system having a camera, a fibre optic light source, and a fibre optic cable connected with the light source and with the camera lens to allow light to pass along the fibre optic cable to the camera, the system being protected from attack by water.

Preferably a housing is provided for at least some of the elements of the system. The housing should be watertight and capable of withstanding ambient pressures.

The camera may for example be for taking still photographs, or "movie pictures", or may be a television camera, and two or more different types of camera may be mounted in the housing. Alternatively a further one or more housings may be provided each enclosing an element of the system acting in conjunction with the elements in the other housing or housings.

The camera may be connected with a remote viewing location, for example at the surface when the system is used underwater, by means of one or more cables, and these may be conventional underwater cables, currently used with television and other cameras. This avoids the use of long runs of fibre optic cable which is very expensive.

When the camera is of single lens reflex type a television camera can be mounted behind it to take pictures through the lens of the SLR camera; thus both television pictures and intermittent stills photographs can be taken through the lens of the SLR camera.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Figures 1 to 5 are schematic diagrams showing alternative imaging systems of the invention for underwater use.

In these embodiments of the invention various elements of the system are common, and the same reference numerals will be used to identify these common elements in each case.

Referring now to Figure 1,the imaging system has a housing 1 which is designed for use at considerable depths underwater and is therefore watertight and resistant to external pressure. Within the housing 1 several elements are mounted as follows.

A fibre optic light source 2 is power fed through an electrical cable 3 which extends from a bundle of cables 4 extending to the housing 1 from the surface of the water. A cable 5 carries the light from the source 2 to a fibre optic lens unit 6, and the light is thence transmitted through the wall of the housing 1 to an outlet external of the housing 1 by a fibre optic cable 7.

Alternatively, as shown in broken lines on Figure 1, the light can be passed directly from the source 2 through the cable 5 to run in conjunction with the fibre optic cable 7.

The lens unit 6 has attached to it a controller 8 for determining movement of the fibre optic cable 7 an door lens unit 6. The controller 8 is powered electrically through a cable 9 extending from the bundle 4.

A single lens reflex camera 10 is mounted behind the lens unit 6 through a lens adaptor 11 so as to receive light therethrough from the fibre optic cable 7. Behind the camera 10 through a further lens adaptor 12 is mounted a television camera 13 which views through the lens of the SLR camera 10.

The SLR camera 10 has an electric cable 14 from the bundle 4 and the television camera 13 has a TV cable 15. The TV cable 15 and bundle of cables 4 pass out of the housing 1 through a seal/penetrator 16, while the fibre optic cable 7 passes out through a seal/penetrator 17. Apart from these seal/penetrators 16 and 17 the housing 1 has no apertures in its wall.

In use, the system of Figure 1 can be used to inspect areas underwater where access is severely limited, simply by inserting the fine fibre optic cable 7, either manually by a diver or remotely, into the desired area and actuating the SLR and/or television camera 10, 13 to view. The signals from the cameras 10, 13 pass through the cables 14, 15 to the surface where the results are observed and recorded.

The system shown in Figure 1 has the cameras 10 and 13 mounted in-line. Figure 2 shows a system of the invention in which the camera 10 and 13 are mounted separately and an image separator 18 is disposed between them and the lens unit 6. In other respects the system is similar to that of Figure 1 and operates in the same way.

In Figure 3 the system is split between a number of interconnected parts. A first housing 1 A contains the light source 2, the cables 5 and the lens 6 with its controller 8. A second housing 1 B is detachably connected to the housing 1A and the lens adaptor 11 extends between them, with the walls of the housings 1A, 18 being sealed to the adaptor 11 at its exit locations to prevent ingress of water, The television camera 13 is adapted for use underwater and requires no external housing for protection, and its lens adaptor 12 passes through the wall of the housing 18 in a sealed manner.

Figure 4 shows a similar system to that of Figure 1 with exception that the television camera 13 is mounted through its lens adaptor 12 on the lens unit 6. No SLR camera 10 is provided.

In Figure 5 an underwater television camera 13 is used external of the housing 1, as in Figure 3, but no SLR camera 10 is provided.

The systems of these embodiments of the invention can be used underwater manually by a diver swimming tethered or free; remotely by remote controlled vehicles, submersibles or manipulators whether tethered, untethered, manned or unmanned; or from temporarily or permanently installed subsurface apparatus or structures. They can be used for underwater image collection, study and recording of permanent or temporary or free flowing objects, and allow a user to observe and record an image within, for example, a crack in an internal or external portion of a structure. They also allow a user to observe and record images in confined spaces or in areas where direct line of sight is restricted or denied.

By using the systems of these embodiments an image can be transmitted to the surface through the bundle of cables 4 and TV cable 15, or the image may be displayed and recorded locally within or nearthe system.

The television camera 13 in Figure 1 can be of surface or underwater type, and may generally be colour or monochrome. It may be colour collection type.

The TV cable may be coaxial, pairs or single strand.

The SLR camera may be of stills or motion format.

The fibre optic cable 7 may be a cable, a bundle or a strand.

The light source 2 may be fixed or variable intensity.

The housing 1 may contain fluid such as air, inert gas, oil or mineral-based products which at depth equalise or reduce the differential between the pressure within and outside the housing 1.

Modifications and improvements may be made without departing from the scope of the invention.

Claims (14)

1. An underwater imaging system comprising a camera, a light source, and fibre optic cable means connected with the light source and with the camera lens so that light can pass along the fibre optic cable means from the light source to an object to be viewed and thence along the fibre optic cable means to the camera, the system being adapted for underwater use by the provision of one or more watertight housings within which elements of the system are contained.

2. A system according to claim 1, wherein the camera and the light source are contained within a single watertight housing.

3. A system according to any one of the preceding claims, wherein the camera has cable connected to it for transmitting images received by the camera to the water surface.

4. A system according to any one of claims 1 to 3, wherein electrical power is provided forthe light source and/orthe camera through cable connecting the system to the water surface.

5. A system according to any one of claims 1 to 4, wherein the camera is a single lens reflex camera.

6. A system according to any one of claims 1 to 4, wherein the camera is a television or movie camera.

7. A system according to any one of claims 1 to 4, wherein a television or movie camera is mounted adjacent a single lens reflex camera and arranged to receive light through the lens of the single lens reflex camera.

8. A system according to any one of the preceding claims, wherein at least a part of the fibre optic cable means is movable and its movement is determined by control means within said housing.

9. A system according to any one of the preceding claims, wherein said housing contains fluid for resisting the effect of external water pressure on the housing.

10. An underwater imaging system substantially as herein before described with reference to and as shown in Figure 1 of the accompanying drawings.

11. An underwater imaging system substantially as hereinbefore described with reference to and as shown in Figure 2 of the accompanying drawings.

12. An underwater imaging system substantially as hereinbefore described with reference to and as shown in Figure 3 of the accompanying drawings.

13. An underwater imaging system substantially as hereinbefore described with reference to and as shown in Figure 4 of the accompanying drawings.

14. An underwater imaging system substantially as hereinbefore described with reference to and as shown in Figure 5 of the accompanying drawings.