GB2059098A

GB2059098A - Cover for cuvettes

Info

Publication number: GB2059098A
Application number: GB8025079A
Authority: GB
Original assignee: Optische Werke G Rodenstock
Current assignee: Optische Werke G Rodenstock
Priority date: 1979-09-14
Filing date: 1980-07-31
Publication date: 1981-04-15
Also published as: DE7926157U1; FR2465216A1

Abstract

A cover (7) for a cuvette (1), for use in the measurement of e.g. a soft contact lens (6) immersed in a clear liquid (5) by means of an ophthalmometer (4), has a bottom (8) which projects into the liquid, bores (11) which allow the bottom to be properly wetted and displaced fluid to escape, and a support flange (10) which rests on the cuvette. At least the lower surface of the bottom is matt black to absorb light, and is tapered outwardly upwards so that air bubbles can rise towards the edge. <IMAGE>

Description

SPECIFICATION Cover for cuvettes This invention relates to a coverforcuvettes.

Contact lenses, in particular soft contact lenses, are laid in fluid-filled cuvettes for the purpose of optical measurement of the surface shapes thereof, for which purpose the optical measurement operation can be effected by means of a usual opthalmometer. The measuring beam of an opthalmometer usually extends horizontally, and is directed upwardly by means of a prism on to the cuvette which is disposed on the prism. Measurement may however be from the bottom or the side. The measuring operation is impeded by downwardly incident extraneous light or by reflection phenomena at the surface of the fluid.

The present invention is defined in the appended claims to which reference should now be made.

Thus wetting or immersion of the bottom of the cover, which is preferably of a matt black nature, prevents reflection atthesurface ofthe immersion fluid during the measuring operation.

When the cover is inserted into the cuvette, immersion fluid below the bottom of the cover must be capable of escaping in an upward direction, and for this purpose suitable passages are provided; for example, in the case of a cup-shaped cover which is closed all around, the passage can be in the form of fine bores in the bottom of the cover.

The bottom of the cover can be of a configuration which rises slightly from the middle towards the edge, so that air bubbles can rise towards the edge.

When the cover is of a cup-shaped configuration, an upwardly extending cylindrical portion may be connected to the bottom of the cover, and in turn has at its upper end a support flange which extends outwardly and which rests on the wall of the cuvette.

The cylinder region and the support flange may have interruptions therein, and the bottom may also be supported on preferably three suitably bent support arms.

An embodiment of the innovation is illustrated by way of example in the drawing, which shows a vertical sectional view through a cuvette having a cover embodying the invention.

The cuvette 1 has a clearly transparent bottom 2 and is arranged on the prism 3. The measuring beam of an opthalmometer 4 is deflected upwardly by the prism 3 and reaches the contact lens 6 in the immersion liquid 5. The cover 7 has a cylindrical projection 9 which extends upwardly from the tapered bottom 8 and a radially outwardly extending support flange 10 is joined to the cylindrical projection 9 at the top thereof. Provided in the bottom 8 are fluid passages in the form of fine bores 11. At least the lower surface of the bottom 8 is coloured matt black so as to absorb light.

With such a cover downwardly incident extraneous light is kept away and also reflection at the surface of the fluid is essentially eliminated.

1. A cover for cuvettes having clearly transparent bottom or side regions, for optical measurement of objects in a cuvette which is filled with clear fluid, in which the bottom of the cover projects into the fluid, at least one fluid passage is provided which leads from the underside to the top side of the bottom, and the cover has a support flange or support arms for resting on the wall of a cuvette.

2. A cover according to claim 1, in which at least the side thereof which is towards the cuvette is capable of absorbing light.

3. A cover according to claim 1 or 2, in which the cuvette and the cover are of circular cross-section, and the bottom is of an outwardly upwardly tapered configuration.

4. A cover according to claim 3, including a cylindrical projection extending from the bottom upwardly and a support flange extending outwardly from the cylindrical projection.

5. A cover according to claim 4, in which the bottom has a fluid passage in the form of a plurality of fine bores.

6. A cover for cuvettes substantially as herein described with reference to the drawing.

7. A cuvette provided with a cover in accordance with any preceding claim.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Cover for cuvettes This invention relates to a coverforcuvettes. Contact lenses, in particular soft contact lenses, are laid in fluid-filled cuvettes for the purpose of optical measurement of the surface shapes thereof, for which purpose the optical measurement operation can be effected by means of a usual opthalmometer. The measuring beam of an opthalmometer usually extends horizontally, and is directed upwardly by means of a prism on to the cuvette which is disposed on the prism. Measurement may however be from the bottom or the side. The measuring operation is impeded by downwardly incident extraneous light or by reflection phenomena at the surface of the fluid. The present invention is defined in the appended claims to which reference should now be made. Thus wetting or immersion of the bottom of the cover, which is preferably of a matt black nature, prevents reflection atthesurface ofthe immersion fluid during the measuring operation. When the cover is inserted into the cuvette, immersion fluid below the bottom of the cover must be capable of escaping in an upward direction, and for this purpose suitable passages are provided; for example, in the case of a cup-shaped cover which is closed all around, the passage can be in the form of fine bores in the bottom of the cover. The bottom of the cover can be of a configuration which rises slightly from the middle towards the edge, so that air bubbles can rise towards the edge. When the cover is of a cup-shaped configuration, an upwardly extending cylindrical portion may be connected to the bottom of the cover, and in turn has at its upper end a support flange which extends outwardly and which rests on the wall of the cuvette. The cylinder region and the support flange may have interruptions therein, and the bottom may also be supported on preferably three suitably bent support arms. An embodiment of the innovation is illustrated by way of example in the drawing, which shows a vertical sectional view through a cuvette having a cover embodying the invention. The cuvette 1 has a clearly transparent bottom 2 and is arranged on the prism 3. The measuring beam of an opthalmometer 4 is deflected upwardly by the prism 3 and reaches the contact lens 6 in the immersion liquid 5. The cover 7 has a cylindrical projection 9 which extends upwardly from the tapered bottom 8 and a radially outwardly extending support flange 10 is joined to the cylindrical projection 9 at the top thereof. Provided in the bottom 8 are fluid passages in the form of fine bores 11. At least the lower surface of the bottom 8 is coloured matt black so as to absorb light. With such a cover downwardly incident extraneous light is kept away and also reflection at the surface of the fluid is essentially eliminated. CLAIMS

7. A cuvette provided with a cover in accordance with any preceding claim.