Method and apparatus for detecting the presence of a moulding in an open blister package based on sensed temperature differences

• US 6,471,396 B2
• Filed: 11/29/2000
• Issued: 10/29/2002
• Est. Priority Date: 12/03/1999
• Status: Expired due to Term

• Current Assignee: Alcon Incorporated
• Original Assignee: Novartis Ag
• Inventors: Biel, Roger
• Primary Examiner(s): Gutierrez, Diego
• Assistant Examiner(s): PRUCHNIC, STANLEY J
• Application Number:
  US09/725,405
• Publication Number:
  US 20010009561A1
• Time in Patent Office: 699 Days
• Field of Search: 374/45, 374/4, 374/5, 374/6, 374/7, 374/120, 374/121, 374/124, 374/129, 374/53, 374/16, 374/10, 250/358.1, 250/340, 250/342, 250/338.1, 53/52, 53/55, 53/56, 53/57, 53/58, 534/93, 534/94, 534/98
• US Class Current: 374/45
• CPC Class Codes: G01N 21/9508 Capsules; Tablets
• CPC Class Codes: G01N 25/72 Investigating presence of flaws

Abstract

The invention relates to a method and a device for registering the presence of an ophthalmic moulding consisting of a biocompatible polymeric material, especially an ophthalmic lens, particularly a contact lens, in a package. The invention solves the problem through the use of an IR camera. Packages containing a moulding, especially a contact lens, have a change in their temperature distribution compared with a package without a contact lens. By evaluating the temperature difference, it is possible to determine whether or not there is a contact lens in a package. In particular, by using the detecting method according to the invention, one can determine whether there is a contact lens in the package directly after the filling procedure.

Claims

1. A method for detecting the presence of a moulding in an open blister package, the method comprising:

measuring at least one temperature of a first open blister package with a moulding to obtain a first temperature measurement;

measuring at least one temperature of a second open blister package without a moulding to obtain a second temperature measurement; and

detecting the presence of the moulding in the first open blister package based on a difference between the first temperature measurement and the second temperature measurement.

2. The method according to claim 1, wherein the first and second temperature measurements are local temperature measurements.

3. The method according to claim 1, wherein an infrared line camera is used to measure the temperatures of the open blister packages.

4. The method according to claim 3, wherein said infrared line camera has a resolution of 0.5 to 0.1 K.

5. The method according to claim 4, wherein said infrared line camera has a resolution of 0.2 K.

6. The method according to claim 3, wherein a sensor is used to detect when a package enters and/or leaves a measuring area of the infrared line camera.

7. The method according to claim 1, wherein temperatures of several open blister packages are measured simultaneously.

8. The method according to claim 1, wherein ventilators are arranged over the package to increase air exchange over the package prior to measuring the temperatures.

9. The method according to claim 1, wherein the moulding is a contact lens.

10. A method for detecting the presence of a moulding in an open blister package, the method comprising:

measuring a first local temperature distribution of a first zone of an open blister package, wherein the moulding is contained in the first zone;

measuring a second local temperature distribution of a second zone of the open blister package, wherein the moulding is not contained in the second zone; and

detecting the presence of the moulding in the open blister package based on a difference between the first local temperature distribution of the first zone and the second local temperature distribution of the second zone.

11. The method according to claim 10, wherein local temperature measurements of several open blister packages are carried out simultaneously.

12. The method according to claim 10, wherein an infrared line camera is used to measure local temperature distributions of the open blister packages.

13. The method according to claim 12, wherein said infrared line camera has a resolution of 0.5 to 0.1 K.

14. The method according to claim 13, wherein said infrared line camera has a resolution of 0.2 K.

15. The method of claim 12, wherein a sensor is used to detect when a package enters and/or leaves a measuring area of the infrared line camera.

16. The method of claim 10, wherein ventilators are arranged over the open blister package to increase air exchange over the open blister package prior to measuring the local temperature distributions.

17. A method of claim 10, wherein the moulding is a contact lens.

18. An apparatus for detecting the presence of a moulding in an open blister package, comprising:

an infrared line camera for measuring local temperature distributions of at least two zones of the open blister package, wherein the moulding is contained in one of the at least two zones of the open blister package while the moulding is not contained in the other zone of the open blister package;

a sensor for detecting when the open blister package enters and/or leaves a measuring area of the infrared line camera; and

an electronic evaluation means for evaluating a difference between the local temperature distributions of the at least two zones of the open blister package.

19. An apparatus according to claim 18, wherein the infrared line camera has a resolution of 0.5 to 0.1 K.

20. An apparatus according to claim 19, wherein the infrared line camera has a resolution of 0.2 K.