GB2396435A

GB2396435A - Magnetic lens focus setting for watertight camera

Info

Publication number: GB2396435A
Application number: GB0229403A
Authority: GB
Inventors: Lin Ching-Wen
Original assignee: A ONE OPTOELECTRONICS CO Ltd
Current assignee: A ONE OPTOELECTRONICS CO Ltd
Priority date: 2002-12-17
Filing date: 2002-12-17
Publication date: 2004-06-23
Also published as: GB0229403D0

Abstract

A lens focus setting structure for a watertight camera 20 comprises two internal magnets 31, 41 separately fixedly connected to two collar adjustments 15, 16 that are mounted around two lens mounts 11, 12 axially movably engaged with two ends of a zoom lens 10 inside the camera, and two external magnets 30, 40 movably attached to an outer wall surface of the camera to separately correspond to and magnetically attract the two internal magnets. When the external magnets are moved, the internal magnets and accordingly the collar adjustments connected thereto are brought to move at the same time, causing the lens mounts to move forward or rearward relative to the zoom lens to enable focus setting from outside of the camera without the need of opening an enclosure thereof.

Description

LENS FOCUS SETTING STRUCTURE FOR WATERTIGHT CAMERA

FIELD OF THE INVENTION

5 The present invention relates to a lens focus setting structure for watertight camera, end more particularly to alens focus setting structure for a camera included in a supervising system to enable lens focus setting without the need of opening an enclosure of the camera, 10 so that the camera maintains watertight during operation thereof.

BACKGROUND OF THE INVENTION

15 Lens for the commercially available cameras are generally divided into two types, namely, fixed lens end zoomlens. Figs. land2areexplodedandassembled perspective views, respectively, of a conventional zoom lens 10. As shown, the zoom lens 10 has two lens 20 mounts, namely, an outer-end lens mount 11, which is a focusing lens, and an inner-end lens mount 12, which is a dual-focusing lens, engaged with outer and inner ends thereof. When the two lens mounts 11, 12 are adjusted forward or rearward in their position 25 relative to the zoom lens 10, the supervising camera may be set to different supervising ranges and visual angles.

\ The two lens mounts 11 and 12 are provided along an outer circumferential surface with three equally spaced projections 111 and 121, respectively. The 5 projections 111, 121 may be fixed in place on the lens mounts 11, 12 by way of, for example, screwing. The zoom lens 10 is provided at positions separately corresponding to the outer-end and innerend lens mounts 11, 12 with two sets of three equally spaced 10 curved guiding slots 13, 14 corresponding to the projections 111, 121, such that the projections 111, 121 are separately movable in the curved guiding slots 13, 14. When the projections 111, 121 are caused to move in and along the corresponding curved guiding 15 slots 13, 14, the positions of the lens mounts 11, 12 relative to the zoom lens 10 are forward or rearward adjusted. The zoom lens 10 also has first and second collar adjustments 15, 16 separately mounted to two ends thereof over the lens mounts 11, 12. The two 20 collar adjustments 15, 16 are provided on respective inner wall surfaces with three axially extended and circumferentially equally spaced linear grooves 151, 161 corresponding to the projections 111, 121. When the collar adjustments 15, 16 are turned, the grooves 25 151, 161 would bring the lens mounts 11, 12 to rotate along with the collar adjustments 15, 16. And, when the lens mounts 11, 12 rotate, the projections 111,

121 are brought to move in and along corresponding curved slots 13, 14 and thereby move the lens mounts 11, 12 forward or rearward. To enable convenient setting of lens focus via the collar adjustments 15, 5 16, two focusing levers 152, 162 are provided on outer surfaces of the collar adjustments 15, 16 for easily turning them.

To perform lens focus setting with the above-described 10 structure, it is necessary to open an enclosure of the camera (not shown) to expose the focusing levers 152, 162 for operation. However, for a watertight camera that is mainly designed for use under water, it is not allowable to open the enclosure of the camera under 15 water to perform the lens focus setting. For this reason, the currently available watertight cameras all have a lens with non-variable length of focus.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a lens focus setting structure for watertight camera to enable focus setting for internal lens from outside of the watertight camera, so that the watertight camera 25 can be conveniently used to take images at different focusing ranges and visual angles.

With the lens focus setting structure of the present invention, a user may easily control the lens focus of a watertight camera without the need of opening the enclosure to adversely affect the watertightness 5 thereof.

To achieve the above and other objects, the lens focus setting structure of the present invention mainly includes internal magnets separately fixedly 10 connected to two collar adjustments in a camera, and external magnets separately movably provided at an outer wall surface of the camera corresponding to the two internal magnets. When the external magnets are moved, theinternal magnets end accordingly the collar 15 adjustments are synchronously moved due to a magnetic attraction between the internal and the external magnets. The focus setting of the camera can therefore be achieved through movement of the external magnets.

20 BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the 25 following detailed description of the preferred

embodiments and the accompanying drawings, wherein

Fig. 1 is an exploded perspective view of a conventional zoom lens; Fig. 2 is an assembled perspective view of Fig. It Fig. 3 is a perspective view of a camera having a lens focus setting structure according to the present invention; and 10 Fig. 4 is a partially sectioned side view of Fig. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to Figs. 3 and 4 that are perspective and 15 partially sectioned side views, respectively, of a camera 20 having a lens focus setting structure according to the present invention. The camera 20 may be a watertight camera for use under water, or a camera includedina supervising system. As shown, the camera 20 20 isinternally provided with a zoom lens 10, to outer and inner ends of which, forward and rearward movable lens mounts 11, 12 are connected. The outer-end lens mount 11 is a focusing lens while the inner-end lens mount 12 is a dual-focusing lens. First and second 25 collar adjustments 15, 16 are mounted over the outer and the inner lens mount 11, 12, respectively, for moving the two lens mounts 11, 12 forward or rearward.

The above-described structure for the zoom lens 10 is a known art, as shown in Fig. 2.

In the present invention, a first internal magnet 31 5 is fixedly connected to the first collar adjustment 15, and a first external magnet 30 is movably attached to an outer wall surface of the camera 20 at a position corresponding to the first internal magnet 31, so that the first internal and external magnets 31, 30 10 magnetically attract each other. Similarly, a second internal magnet 41 is fixedly connected to the second collar adjustment 16, and a second external magnet 40 is movably mounted to an outer wall surface of the camera 20 at a position corresponding to the second 15 internal magnet 41, so that the second internal and external magnets 41, 40 magnetically attract each other. When the first externalmagnet 30 is moved, the first collar adjustment 15 is brought to rotate at the same time due to the magnetic attraction force between 20 the first external and the first internal magnet 30, 31. The rotation of the first collar adjustment 15 in turn causes the outer-end lens mount 11 on the zoom lens 10 to move forward or rearward relative to the zoom lens 10. Similarly, when the second external 25 magnet 40 is moved, the second collar adjustment 16 is brought to rotate et the same time due to the magnetic attraction force between the second external and

internal magnets 40, 41. The rotation of the second collar adjustment 16 in turn causes the inner-end lens mount 12 on the zoom lens lOtomove forward or rearward relative to the zoom lens 10. Through adjustment of 5 positions of the outer-end end theinner-endlens mount 11, 12, lens focus setting for the camera 20 can be achieved. The camera 20 has an enclosure that is usually made 10 of a non-magnetically-conductive material, such as aluminum. The camera20 also has internal components, most of which are made of a plastic material. Thus, the magnetic attraction of the external magnets 30, 40 would only act on the correspondinginternalmagnets 15 31, 41. Meanwhile, to minimize a mutual interference between them, the first external and internal magnets 30, 31 and the second external and internal magnets 40, 41 are provided in the enclosure of the camera 20 with a phase difference of 180 degrees between them.

The camera 20 is provided on the outer wall surface with two guiding grooves 21 and 22 for the two external magnets 30 and 40, respectively, to move therein. The external magnets 30, 40 moving in the guiding grooves 25 21, 22 are magnetically attracted by the internal magnets 31, 41 without the risk of separating from the guiding grooves 21, 22. Alternatively, the guiding

grooves 21, 22 may have a counterbored top inner edge (not shown) to ensure that the external magnets 30, 40 are firmly set in the counterbored guiding grooves 21, 22 without the risk of separating therefrom.

s In the above-described embodiment of the present invention, the positions of the outer-end and inner-end lens mounts 11, 12 relative to outer and inner ends, respectively, of the zoom lens 10 is 10 controlled through turning of the first and second collar adjustments 15, 16, respectively. Therefore, the external magnets 30, 40 of the camera 20 are moved leftward or rightward along the guiding grooves 21, 22 to turn the collar adjustments 15, 16. In another 15 embodiment, the collar adjustments 15, 16 inside the camera 20 are axially moved forward or rearward (not shown). In this case, the external magnets 30, 40 are designed to move forward or rearward on the outer wall surface of the camera.

In brief, the present invention employs magnetic attraction and simple structure to enable focus setting for a zoom lens inside a camera without the need of opening the enclosure of the camera. Therefore, 25 with the present invention, it is possible to achieve fens focus setting for a watertight camera under wafer.

Claims

What is claimed is:

1.Alens focus setting structure for watertight camera, said camera being internally provided with a zoom 5 lens, with outer andinner ends of which en outer-end lens mount, which is a focusing lens, and an inner-endlens mount, which isadual-focusinglens, are axially movably engaged, and said outer-end and inner-end lens mounts being controlled via a first 10 and a second collar adjustment, respectively, mounted therearound to move forward or rearward relative to said zoom lens, said lens focus setting structure comprising: 15 a first internal magnet fixedly connected to said first collar adjustment; a first external magnet movably attached to an outer wall surface of said camera corresponding to said 20 first internal magnet, so that said first internal magnet and said first external magnet magnetically attract each other; a second internal magnet fixedly connected to said 25 second collar adjustment; and a second external magnet movably attached to said

outer wall surface of said camera corresponding to said second internal magnet, so that said second internal magnet and said second external magnet magnetically attract each other.

2.The lens focus setting structure for watertight camera as claimed in claim 1, wherein said camera is provided on said outer wall surface with two guiding grooves for said first and said second 10 external magnet to separately move therein.