Method and system for optical camber measurement of flat sheet membranes, films, and webs

Patent metadata

Field	Value
Publication number	US-9541384-B2
Application number	US-201414205849-A
Country	US
Kind code	B2
Filing date	Mar 12, 2014
Priority date	Mar 12, 2013
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A system, method, and device for measuring camber in a film is disclosed. The system generally includes: a flat surface with a longitudinal axis, at least three sensors spaced apart along the longitudinal axis, and a computing device operatively connected to each sensor. When the film is positioned in relationship to the sensors, the computing device computes the camber of the film. The flat surface may be a table with a film holder. At least one of the sensors may be a LED sensor. The computing device may have an output means, such as a monitor, a printer, or both. The computing device defines a straight line between the first and third sensor based on the position of the film, and the camber is a deviation of the film, measured by the second sensor, from the straight line.

First claim

We claim:

1. A system for measuring camber in a stationary film comprising:
a flat surface with a longitudinal axis, said flat surface is part of a table, said table has a film roll holder, the stationary film lays flat on said flat surface,
at least three stationary sensors spaced apart along said longitudinal axis, each of said sensors includes a light emitting diode (LED) sensor, a scanning laser, a translating laser, a charged coupled device (CCD) camera, or a high definition video camera, the first and third sensors being at least one meter apart, and
a computing device operatively connected to each said sensor, whereby when the stationary film is positioned in relationship to said sensors, said computing device computes the camber of the stationary film by defining a straight line between the first and third sensor at an actual lateral edge of the stationary film, measuring the actual edge of the stationary film by the second sensor between the first and third sensors, and the camber is a deviation of the measurement from the second sensor measurement and the straight line, the computed camber is accurate to less than ±0.5 mm.

2. The system of claim 1 wherein at least one of the sensors is a LED sensor.

3. The system of claim 1 wherein each said sensor is a LED sensor.

4. The system of claim 1 wherein said computing device has an output means.

5. The system of claim 4 wherein said output means is a monitor, a printer, or both.

6. A method for measuring camber in a stationary film comprising the steps of:
positioning a stationary film having a lateral edge on a flat surface adjacent at least three stationary sensors, each of said sensors includes a light emitting diode (LED) sensor, a scanning laser, a translating laser, a charged coupled device (CCD) camera, or a high definition video camera, the first and third sensors being at least one meter apart, said flat surface is part of a table, said table has a film roll holder, the stationary film lays flat on said flat surface,
determining a straight line between an actual edge position of the lateral edge of the stationary film at a position of the film at the first and third sensor,
determining an actual edge position of the lateral edge of the stationary film at the second sensor, and
calculating a deviation of the actual edge position of the film at the second sensor from the straight line, the deviation is the camber, the calculated camber is accurate to less than ±0.5 mm.

7. A device measuring camber in a stationary film comprising:
a flat surface with a longitudinal axis, said flat surface is part of a table, said table has a film roll holder, the stationary film lays flat on said flat surface,
at least three stationary sensors spaced apart along said longitudinal axis, each of said sensors includes a light emitting diode (LED) sensor, a scanning laser, a translating laser, a charged coupled device (CCD) camera, or a high definition video camera, the first and third sensors being at least one meter apart, and
a computing device operatively connected to each said sensor, whereby when the stationary film is positioned in relationship to said sensors, said computing device computes the camber of the stationary film by defining a straight line between the first and third sensor at an actual lateral edge of the stationary film, measuring the actual edge of the stationary film by the second sensor between the first and third sensors, and the camber is a deviation of the measurement from the second sensor measurement and the straight line, the computed camber is accurate to less than ±0.5 mm, the stationary film is a membrane, film, or web.

8. The device of claim 7 wherein at least one of the sensors is a LED sensor.

9. The device of claim 7 wherein each said sensor is a LED sensor.

10. The device of claim 7 wherein said computing device has an output means.

11. The device of claim 10 wherein said output means is a monitor, a printer, or both.

Assignees

• Celgard Llc

Inventors

• Ham Bogyeol
• Bourcier David P
• Freeman Alan H

Classifications

• G01B11/306 Primary

  for measuring evenness · CPC title

• G01B11/245

  using a plurality of fixed, simultaneously operating transducers ({G01B11/2408 - G01B11/2425, } G01B11/255 take precedence) · CPC title

• B21B38/12

  for measuring roll camber · CPC title