Ophthalmic lens inspection system and method

• US 5,745,230 A
• Filed: 07/29/1996
• Issued: 04/28/1998
• Est. Priority Date: 12/21/1992
• Status: Expired due to Term

• Current Assignee: Johnson & Johnson Vision Products, Inc.
• Original Assignee: Johnson & Johnson Vision Products, Inc.
• Inventors: Ravn, Thomas Christian, Ebel, James A., Edwards, Russell J., Gundersen, Borge Peter
• Primary Examiner(s): Pham, Hoa Q.
• Application Number:
  US08/681,639
• Time in Patent Office: 638 Days
• Field of Search: 356/124-127, 356/237, 356/239, 356/240, 356/430, 356/244, 356/246, 264/2.6, 250/572, 250/223 B, 250/562, 358/101, 358/106, 358/107, 382/8, 382/65, 206/5.1, 206/562, 206/563
• US Class Current: 356/124
• CPC Class Codes: G01M 11/0207 Details of measuring devices
• CPC Class Codes: G01M 11/0214 Details of devices holding the object to be tested

Abstract

A lens inspection method and apparatus comprising a pallet having wells for receiving one or more lens containers at the receiving point. A conveyor achieves uniformity of pallet motion when transporting the lens. The pallet wells includes holes that pass through the pallet. These holes, along with a side driven transport system, make possible an arrangement of a lamp and camera on opposite sides of the lens for capturing an image of a lens. A computer implemented algorithm processes the digitized image to determine the acceptability of the lenses. A lens disposition mechanism uses a signal generated by the computer and indicates lens acceptability to disposition the lens by physically separating a container with an acceptable lens from an unacceptable lens. After disposition of containers, the pallet is returned by conveyor to the lens receiving point.

Claims

1. An apparatus for the inspection of ophthalmic lenses comprising:

a lens pallet having wells for receiving, at a lens container receiving area, a plurality of lens containers for holding a plurality of ophthalmic lenses,

an inspection station including a lamp for illuminating the lenses and the lens containers, and a camera for capturing an image of the lenses produced during illumination of the containers,

image analysis means connected to the camera to receive the images of the lenses from the camera, to determine whether individual ones of the lenses are acceptable or unacceptable, and to produce signals identifying said individual ones of the lenses as acceptable or unacceptable,

a lens disposition mechanism connected to the image analysis means to receive the signals therefrom and, in response to said signals, to remove the lens containers from the pallet and to physically separate acceptable lenses from unacceptable lenses,

a conveyor for transporting the pallet in a first direction from the lens container receiving area to the inspection station then to the lens disposition mechanism,

a pallet restraining means for minimizing movement of the pallet in directions other than the first direction, and

means for returning the pallet from the lens disposition mechanism to the container receiving area.

2. The apparatus of claim 1 wherein said lens containers are lens packages, and said apparatus further comprises a package sealing station.

3. The apparatus of claim 2 further comprising a saline dosing station between the inspection station and the package sealing station.

4. The apparatus of claim 1 wherein the apparatus further comprises a sensor responsive to a triggering means on said pallet, the sensor electrically connected to the lamp for initiating the illumination.

5. The apparatus of claim 1 wherein the pallet wells for receiving a plurality of lens containers comprise holes passing through the pallet from a bottom pallet surface to a top pallet surface.

6. The apparatus of claim 5 wherein the inspection station is so arranged that a pallet at the inspection station has the lamp located beyond the plane of one of the pallet top and bottom surfaces, the camera is located beyond the plane of the other surface, and the illumination of the lens takes place along a path through the holes in the pallet.

7. The apparatus of claim 1 wherein the pallet further comprises side walls and top and bottom surfaces, wherein the side walls are substantially perpendicular to the top and bottom surfaces, and the pallet restraining means comprises mechanical bias means located on the side walls and the pallet restraining means further comprises guide rails on the conveyor which are positioned to compress the pallet mechanical bias means when the pallet is between the guide rails.

8. The apparatus of claim 7 wherein the pallet comprises an engagement means and the conveyor comprises a drive means for engaging the pallet engagement means and transporting the pallet.

9. The apparatus of claim 1 wherein the pallet further comprises locating means and the lens container further comprises a mating locating means, the locating means and the mating locating means capable of interlocking to retain the container on the pallet while transporting by the conveyor.

10. Apparatus according to claim 1, wherein the lens disposition mechanism, in response to the signals from the image analysis means, removes the acceptable lenses from the pallet and transfers the acceptable lenses to a first location, and removes the unacceptable lenses from the pallet and transfers the unacceptable lenses to a second location.

11. Apparatus according to claim 10, wherein the lens disposition mechanism removes from the pallet all of the lens containers held therein.

12. The apparatus of claim 1, wherein said conveyer is a precision conveyor which enables movement of the pallets in the first direction with a pallet movement tolerance of 0.30 mm in other directions.

13. A method of inspecting ophthalmic lenses for use with a movable pallet having a plurality of wells, said method comprising:

providing a pallet conveying means which is capable of transporting the pallet in one direction and capable of restraining movement in other directions,

placing lens containers into the wells of the lens pallet at a container receiving area,

placing ophthalmic lenses into the lens containers,

transporting the pallet from the container receiving area to an inspection station comprising a lamp and a camera,

illuminating the lenses and the containers with the lamp, and capturing with the camera images of the lenses produced during illumination of the lens containers,

determining whether lenses contain nonconformities from the images received from the camera,

producing, in response to said determination, signals identifying lenses as acceptable or unacceptable,

transporting the pallet from the inspection station to a lens disposition mechanism,

dispositioning the lenses at the lens dispositioning mechanism consistent with said signals by removing the lens containers from the pallet and physically separating acceptable lenses from unacceptable lenses, and

returning the pallet from the lens disposition mechanism to the container receiving area.

14. The method of claim 13 wherein the unacceptable lenses are separated from that which are acceptable by removing the lens containers with the unacceptable lenses from the pallet.

15. The method of claim 14 wherein removal of the unacceptable lens from the pallet includes removal of the lens containers in which the lenses are reposed.

16. The method of claim 13 wherein the illumination of the lens containers and capturing of lens images occur by passing light through the lens containers, lenses, and holes in the pallet well.

17. The method of claim 13 wherein the illumination of the lenses comprises sensing a triggering means on the pallet, wherein the sensing initiates energy being provided to the lamp.

18. The method of claim 13 wherein said lens containers are the lens packages, the method further comprising the step of sealing the packages with a foil.

19. The method of claim 18 further comprising dosing the packages with saline after determination of acceptability but before sealing the packages.

20. A method according to claim 13, wherein the dispositioning step includes the steps of, in response to said signals, removing the acceptable lenses from the pallet and transferring the acceptable lenses to a first location, and removing the unacceptable lenses from the pallet and transferring the unacceptable lenses to a second location.

21. A method according to claim 20, wherein the dispositioning step further includes the step of removing from the pallet all of the lens containers held therein.

22. The method of claim 13, wherein the step of providing the pallet conveying means restrains pallet movement in the other direction to a tolerance of 0.30 mm.