METHOD AND APPARATUS FOR DETECTING PARTICULAR MATTER IN SEALED LIQUIDS

• US 3,627,423 A
• Filed: 02/17/1970
• Issued: 12/14/1971
• Est. Priority Date: 02/17/1970
• Status: Expired due to Term

• Current Assignee: Daniel J. Verin, Emanuel B. Hershberg, Julius Z. Knapp
• Original Assignee: Daniel J. Verin, Emanuel B. Hershberg, Julius Z. Knapp
• Inventors: Knapp, Julius Z., Verin, Daniel J., Hershberg, Emanuel B.
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Chew, II, Orville B.
• Application Number:
  US05/012,342
• Time in Patent Office: 665 Days
• Field of Search: 250/218,223B 356/197,103,104,102
• US Class Current: 356/340
• CPC Class Codes: G01N 2033/0081 containers; packages; bottles
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke
• CPC Class Codes: G01N 21/9027 in containers after filling

Abstract

A method and apparatus for detecting particulate contaminates in a liquid; the method comprising the steps of positioning the container containing the liquid to be inspected in light paths angularly disposed to a viewing axis and forming an illuminated area with a shadow zone at the viewing axis, rotating the container and the liquid therein in the illuminated area and viewing the liquid from the shadow zone; the apparatus comprising a platform for supporting a container to be inspected, means for rotating and stopping the platform, light sources for directing light at the container at an angle relative to a viewing axis to form an illuminated area through the container with a shadow zone at the viewing axis, a camera having an electrooptical transducer, said camera being mounted at said viewing axis, and means connected to the camera for optically viewing the transduced image.

Claims

1. A method for detecting in relative size particulate matter in a liquid in a transparent container comprising the steps of a. projecting at least two light beams through said container so that they intersect within said liquid, illuminate substantially all of said liquid, exit therefrom and delineate an angular shadow zone radiating outwardly from said container;

b. rotating said container about its axis, at a speed below that at which said liquid cavitates, to cause the liquid in said container and any particulate matter therein to move through said light beams and form a moving image of any particulate matter; and

c. while said liquid and any particulate matter therein are still moving, viewing said illuminated liquid from a position in said shadow zone and off the path of any of said light beams to detect the presence of moving images of particulate matter therein.

2. A method as recited in claim 1 in which the rotation of said container is stopped prior to said viewing.

3. A method as recited in claim 2 in which said viewing position is also outside of the space defined by the planes of the upper and lower surfaces of said liquid.

4. A method as recited in claim 1 in which, prior to viewing, said images are passed through means to prevent the passage of those particle images having less than a prespecified size.

5. Apparatus for inspecting a liquid in a container for particulate contaminates, said apparatus including means for supporting a container, light means for directing at least two light beams at said container and said liquid along light paths angularly disposed to a viewing axis passing through said container so that said lIght paths intersect in said container and illuminate substantially all of said liquid and form an angular shadow zone at said viewing axis, means on said supporting means for rotating said container supported thereon and viewing means at said viewing axis for viewing said container on said supporting means.

6. Apparatus as recited in claim 5 in which said light means includes a first light means for directing said light at said container along a first path angularly disposed at one side of said viewing axis and a second light means for directing said light at said container along a second path angularly disposed at the other side of said viewing axis.

7. Apparatus as recited in claim 6 in which said viewing means includes electro-optical means.

8. Apparatus as recited in claim 7 in which said electro-optical means includes a vidicon camera and a receiver connected, by cable, to said camera, said receiver having a screen responsive to signal impulses from said camera for viewing images of particles in said liquid.

9. Apparatus as recited in claim 8 in which said camera is mounted angularly outside of the space defined by the planes of the upper and lower surfaces of the liquid in said container.

10. Apparatus as recited in claim 9 in which said camera includes an optical screen for allowing the transmission of particle images above a certain size and for preventing the transmission of particle images below said certain size.