Outer and Inner Diameter Measuring Apparatus and Method for Transparent Tube

• US 20080198389A1
• Filed: 05/27/2005
• Published: 08/21/2008
• Est. Priority Date: 01/13/2005
• Status: Abandoned Application

• Current Assignee: LS Cable Limited (LS Corporation)
• Original Assignee: LS Cable Limited (LS Corporation)
• Inventors: Kim, Young-Sun, Bae, Sang-Joon, Cho, Young-Chang, Kim, Young-Ghi, Yoo, Won-Sang
• Application Number:
  US11/813,807
• Publication Number:
  US 20080198389A1
• Time in Patent Office: Days
• US Class Current: 356/626
• CPC Class Codes: G01B 11/105 using photoelectric detection means
• CPC Class Codes: G01B 11/12 internal diameters

Abstract

An outer and inner diameter measuring method for a transparent tube in a non-contact manner includes the steps of irradiating a light having a linear sectional shape, inclined at a pre-determined angle with respect to a plane perpendicular to a length direction of a transparent tube, to the transparent tube; obtaining a light beam pattern formed since the light having a linear sectional shape is intercepted and refracted by the tube; obtaining an inner diameter of the tube by extracting inner diameter information of the tube from the obtained light beam pattern; and obtaining an outer diameter from a light beam pattern refracted by the tube, thereby calculating the outer and inner diameters together.

Claims

1. An outer and inner diameter measuring apparatus for a transparent tube, comprising:

a light beam irradiating means for irradiating a light having a linear sectional shape and inclined at a predetermined angle with respect to a plane perpendicular to a length direction of a transparent tube;

a pattern obtaining means arranged to face the light beam irradiating means with the tube being interposed therebetween so as to obtain a light beam pattern intercepted and refracted by the tube; and

a calculating means for extracting inner diameter information of the tube from a pattern refracted by the tube among the light beam pattern obtained by the pattern obtaining means, and calculating and outputting an inner diameter of the tube.

2. The outer and inner diameter measuring apparatus for a transparent tube according to claim 1, wherein the light beam irradiating means includes:

a laser beam generator;

a linear light converting optical system for converting a laser beam, generated from the laser beam generator, into a light having a linear sectional shape; and

a collimator for converting the laser beam, converted into the light having a linear sectional shape by the linear laser beam converting optical system, into a parallel linear light.

3. The outer and inner diameter measuring apparatus for a transparent tube according to claim 1 or 2, further comprising an IR (infrared) cutoff filter arranged to a light beam output side of the light beam irradiating means.

4. The outer and inner diameter measuring apparatus for a transparent tube according to claim 1, wherein the pattern obtaining means includes:

a screen to which the pattern intercepted and refracted by the tube is projected; and

a camera for photographing the light beam pattern projected to the screen.

5. The outer and inner diameter measuring apparatus for a transparent tube according to claim 1 or 4, further comprising an IR cutoff filter arranged to a light beam input side of the pattern obtaining means.

6. The outer and inner diameter measuring apparatus for a transparent tube according to claim 4, further comprising a band pass filter provided between the screen and the camera.

7. The outer and inner diameter measuring apparatus for a transparent tube according to claim 4, wherein the screen has a light diffusion coating.

8. The outer and inner diameter measuring apparatus for a transparent tube according to claim 1,

wherein the calculating means additionally extracts outer diameter information of the tube from a pattern intercepted by the tube among the light beam pattern obtained by the pattern obtaining means, and calculates and outputs an outer diameter of the tube.

9. An outer and inner diameter measuring method for a transparent tube, comprising:

irradiating a light having a linear sectional shape and inclined at a predetermined angle with respect to a plane perpendicular to a length direction of a transparent tube, to the transparent tube;

obtaining a light beam pattern formed since the light having a linear sectional shape is intercepted and refracted by the tube; and

obtaining an inner diameter of the tube by extracting inner diameter information of the tube from the obtained light beam pattern.

10. The outer and inner diameter measuring method for a transparent tube according to claim 9,

wherein, in the inner diameter obtaining step, the inner diameter information is extracted from a pattern refracted by the tube among the obtained light beam pattern.

11. The outer and inner diameter measuring method for a transparent tube according to claim 10,

wherein, in the inner diameter obtaining step, the inner diameter is calculated by putting a coordinate value of the refracted pattern to an approximate equation for the inner diameter expressed by an equation of multi degrees and multi terms.

12. The outer and inner diameter measuring method for a transparent tube according to claim 9, further comprising:

extracting outer diameter information of the tube from the obtained light beam pattern, and then obtaining an outer diameter of the tube.

13. The outer and inner diameter measuring method for a transparent tube according to claim 12,

wherein, in the outer diameter obtaining step, the outer diameter information is extracted from a pattern intercepted by the tube among the obtained light beam pattern.