Internal color probe

• US 5,963,332 A
• Filed: 08/20/1997
• Issued: 10/05/1999
• Est. Priority Date: 08/20/1997
• Status: Expired due to Fees

• Current Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Original Assignee: General Electric Company
• Inventors: Feldman, Sandra Freedman, Penney, Carl Murray
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): Smith, Zandra V.
• Application Number:
  US08/915,288
• Time in Patent Office: 776 Days
• Field of Search: 356/402, 356/405, 356/425, 356/406, 356/407, 356/408, 356/409, 356/410
• US Class Current: 356/425
• CPC Class Codes: G01J 3/0224 using polarising or depolarising elements
• CPC Class Codes: G01J 3/463 Colour matching
• CPC Class Codes: G01J 3/50 using electric radiation detectors

Abstract

A probe is configured for measuring color in a sample of material having a refractive index. The probe includes a light source that emits a light beam toward the sample. A color sensor is disposed at an oblique angle with the light source and directed toward a common probe zone for containing the sample. The light source and sensor are optically aligned with a reference plane in the probe zone to effect angles of incidence and reflection relative to the zone having a magnitude substantially equal to Brewster'"'"'s maximum polarization angle for the refractive index of the sample, for measuring interior color of the sample.

Claims

1. A probe for measuring color in a sample of material having a refractive index, comprising:

a light source for emitting a light beam toward said sample; and

a color sensor for performing spectrum color analysis disposed at an oblique angle with said light source and directed toward a common probe zone containing said sample, said light source and said sensor being optically aligned with a reference plane in said probe zone to effect angles of incidence and reflection relative thereto having a magnitude substantially equal to Brewster'"'"'s maximum polarization angle for said refractive index of said sample for measuring interior color of said sample.

2. A probe according to claim 1 further comprising a first polarizer optically aligned between said light source and probe zone for polarizing said light beam to minimize a reflection wave from said sample while permitting transmission of a refraction wave into said sample.

3. A probe according to claim 2 wherein said first polarizer comprises a linear polarizer.

4. A probe according to claim 3 further comprising a first lens for collimating said light beam toward said probe zone.

5. A probe according to claim 2 further comprising a second polarizer optically aligned between said probe zone and said sensor for transmitting said refraction wave from said sample to said sensor while blocking transmission of differently polarized light from said sample.

6. A probe according to claim 5 further comprising a second lens optically aligned between said second polarizer and said sensor for focusing collected light said second polarizer upon said sensor.

7. A probe for measuring color in a sample of material having a refractive index, comprising:

a light source for emitting a light beam toward said sample;

a color sensor disposed at an oblique angle with said light source and directed toward a common probe zone containing said sample, said light source and said sensor being optically aligned with a reference plane in said probe zone to effect angles of incidence and reflection relative thereto having a magnitude substantially equal to Brewster'"'"'s maximum polarization angle for said refractive index of said sample for measuring interior color of said sample;

a first polarizer optically aligned between said light source and probe zone for polarizing said light beam to minimize a reflection wave from said sample while permitting transmission of a refraction wave into said sample;

a second polarizer optically aligned between said probe zone and said sensor for transmitting said refraction wave from said sample to said sensor while blocking transmission of differently polarized light from said sample;

a second lens optically aligned between said second polarizer and said sensor for focusing collected light from said second polarizer upon said sensor;

a blender for blending a base resin with a colorant seal to form a blend;

a resin dispenser for adding said resin to said blender;

a colorant dispenser for adding said colorant to said blender; and

a controller operatively joined to said resin and colorant dispensers for controlling the ration of said colorant to said resin in said blend; and

wherein

said color probe is optically joined to said blender to position said probe zone therein for randomly receiving a portion of said blend to define said sample; and

said color probe is operatively coupled to said controller for varying said ratio to control color thereof in response to measured color of said sample.

8. A method for measuring color in a sample of material having a probe zone therein and having a refractive index, comprising:

projecting an incident light beam toward a reference plane within the probe zone of said sample at an angle of incidence to substantially effect Brewster'"'"'s maximum polarization angle for the specific refractive index of said sample; and

measuring internal color of said sample through spectrum color analysis at about Brewster'"'"'s maximum polarization angle relative to a normal to said reference plane for a light wave refracted through said sample from said incident light beam.

9. A method according to claim 8 further comprising polarizing said incident light beam to minimize a reflection wave from said sample, while permitting transmission of a refraction wave into said sample.

10. A method for measuring color in a sample of material having a probe zone therein and having a refractive index, comprising:

projecting an incident light beam toward a reference plane within the probe zone of said sample at an angle of incidence to substantially effect Brewster'"'"'s maximum polarization angle for the specific refractive index of said sample;

measuring color of said sample at about Brewster'"'"'s maximum polarization angle relative to a normal to said reference plane for a light wave refracted through said sample from said incident light beam;

polarizing said incident light beam to minimize a reflection wave from said sample while permitting transmission of a refraction wave into said sample;

blending a base resin with a colorant to form a blend;

controlling the ratio of said colorant to said resin in said blend;

measuring color of a portion of said blend as said sample; and

varying said ratio to control blend color in response to the measured color of said sample.