Automated strip reader densitometer

• US 5,118,183 A
• Filed: 02/13/1990
• Issued: 06/02/1992
• Est. Priority Date: 02/10/1989
• Status: Expired due to Term

• Current Assignee: X-Rite Incorporated (Danaher Corporation)
• Original Assignee: X-Rite Incorporated (Danaher Corporation)
• Inventors: Friend, Timothy R., Peterson, Steven H., Berg, Bernard J., Cargill, Mark A., Boes, Thomas J.
• Primary Examiner(s): Evans, F. L.
• Assistant Examiner(s): Hantis, K. P.
• Application Number:
  US07/480,331
• Time in Patent Office: 840 Days
• Field of Search: 356/73, 356/404, 356/406, 356/407, 356/418, 356/419, 356/425, 356/443, 356/444, 356/446, 356/402, 356/405, 356/416, 364/526
• US Class Current: 356/73
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: G01J 3/524 Calibration of colorimeters
• CPC Class Codes: G01N 2021/0162 using microprocessors for control of a sequence of operations, e.g. test, powering, switching, processing
• CPC Class Codes: G01N 2021/1734 Sequential different kinds of measurements; Combining two or more methods
• CPC Class Codes: G01N 21/4738 Diffuse reflection precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration, e.g. also for testing fluids, fibrous materials
• CPC Class Codes: G01N 21/59 Transmissivity G01N21/25 takes precedence
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04
• CPC Class Codes: G01N 21/86 Investigating moving sheets G01N21/89 takes precedence
• CPC Class Codes: G01N 2201/0694 Microprocessor controlled supply
• CPC Class Codes: G01N 2201/126 Microprocessor processing
• CPC Class Codes: G01N 35/00029 provided with flat sample substrates, e.g. slides G01N35/028 takes precedence

Abstract

A densitometer apparatus (410) is disclosed and is adapted to provide color density measurements of object samples. The densitometer apparatus (410) comprises a source light (580) for projecting light toward an object sample comprising a control strip (588, 620). A reflection optics assembly (576) is adapted to measure light density reflected from the object sample when the object sample is in the form of a paper control strip. A transmission optics assembly (618) is adapted to measure transmission density of light rays projected through the object sample when the object sample is in the form of a film control strip. A motor assembly (426) operating with a drive wheel assembly (434) and idler wheel assembly (440) automatically moves the object sample (588, 620) through the apparatus (410) adjacent the source light (580). A pair of guides (468, 470) are selectively adjustable by the operator to control movement of the object sample (588, 620) through the apparatus (410). In response to input from a key switch assembly (492) activatable by the operator, the apparatus (410) is adapted to perform various color density measurement and calibration functions, and display appropriate information to the operator through the use of a visual display (490).

Claims

1. A densitometer system adapted for measuring color characteristics of object samples under test, said system comprising:

light source means for generating light rays and directing the same onto said object samples;

reflection filter means positioned at a predetermined angle relative to the direction of object illumination by said light source means, and responsive to light rays reflected from said object samples so as to discriminate a predetermined color shade set of spectral responses of said reflected light rays;

transmission filter means positioned relative to the direction of object illumination by said light source means, and responsive to light rays transmitted through said object samples so as to discriminate a predetermined color shade set of spectral responses of said transmitted light rays;

reflection detection means responsive to light rays transmitted through said reflection filter means for generating on separate reflection detection paths reflection signals representative of the intensity of said light rays transmitted through said reflection filter means;

transmission detection means responsive to light rays transmitted through said transmission filter means for generating on separate transmission detection paths transmission signals representative of the intensity of said light rays transmitted through said transmission filter means;

reflection multiplexing means connected to said reflection detection means for time multiplexing said reflection signals on said separate reflection detection paths;

transmission multiplexing means connected to said transmission detection means for time multiplexing said transmission signals on said separate transmission detection paths;

processing means connected to said reflection multiplexing means and to said transmission multiplexing means for processing said multiplexed signals;

input means connected to said processing means for providing operator input to said densitometer system;

display means connected to said processing means for providing visual signals to an operator indicative of functions performed by said densitometer system;

motor means connected to said processing means and adapted to automatically move said object samples through said densitometer system adjacent said light source means so as to provide an automated measurement of a plurality of color patches associated with said object samples; and

guide means mounted to said densitometer system and adjustable by said operator so as to provide a guidance in at least one dimension of said object samples through said densitometer system.

2. A densitometer system adapted for measuring color characteristics of object samples under test, said system comprising:

light source means for generating light rays and directing said light rays onto said object samples;

filter means responsive to light rays reflected from said object samples so as to discriminate a predetermined color shade set of spectral responses of said reflected light rays;

detection means responsive to light rays transmitted through said filter means for generating signals representative of the intensity of said light rays transmitted through said filter means;

processing means connected to said detection means for processing said signals and for generating data representative of color characteristics of said object samples under test;

input means connected to said processing means for providing operator input to said densitometer system;

motive means connected to said processing means and adapted to automatically move said object samples under test through said densitometer system adjacent said light source means, so as to provide an automated measurement of a plurality of color patches associated with said object samples; and

guide means mounted to said densitometer system and adjustable by an operator of said system, so as to provide a guidance in at least one dimension of said object samples through said densitometer system.

3. A densitometer system in accordance with claim 2 characterized in that said filter means comprises reflection filter means positioned at a predetermined angle relative to the direction of object illumination by said light source means, and said reflection filter means is responsive to light rays reflected from said object samples so as to discriminate a predetermined color shade set of spectral responses of said reflected light rays.

4. A densitometer system in accordance with claim 3 characterized in that said detection means comprises reflection detection means responsive to light rays transmitted through said reflection filter means for generating, on separate paths, reflection signals representative of the intensity of said light rays transmitted through said reflection filter means.

5. A densitometer system in accordance with claim 4 characterized in that said system further comprises reflection multiplexing means connected to said reflection detection means for time multiplexing said reflection signals on said separate paths.

6. A densitometer system in accordance with claim 2 characterized in that said filter means comprises transmission filter means positioned relative to the direction of object illumination by said light source means, with said transmission filter means being responsive to light rays transmitted through said object samples so as to discriminate a predetermined color shade set of spectral responses of said transmitted light rays.

7. A densitometer system in accordance with claim 6 characterized in that said detection means comprises transmission detection means responsive to light rays transmitted through said transmission filter means for generating, on separate paths, transmission signals representative of the intensity of said light rays transmitted through said transmission filter means.

8. A densitometer system in accordance with claim 7 characterized in that said system further comprises transmission multiplexing means connected to said transmission detection means for time multiplexing said transmission signals on said separate paths.

9. A densitometer system in accordance with claim 2 characterized in that said system further comprises multiplexing means connected to said detection means for time multiplexing said signals.

10. A densitometer system in accordance with claim 2 characterized in that said system further comprises display means connected to said processing means for providing visual displays to said operator, indicative of functions performed by said densitometer system.

11. A densitometer system in accordance with claim 2 characterized in that said motive means comprises an electric motor.

12. A densitometer system in accordance with claim 2 characterized in that said guide means comprises a film guide bar having an elongated configuration, and further having nubs or similar elements adapted to be secured into slots located adjacent a forward edge of a bottom housing of said densitometer system.

13. A densitometer system in accordance with claim 12 characterized in that said guide means further comprises a pair of film guides, including a left film guide and a right film guide for capturing said object samples for guidance in at least one dimension into said densitometer system.

14. A densitometer system in accordance with claim 13 characterized in that said guide means further comprises a recessed portion of a housing assembly of said densitometer system, with said recessed portion including indicia for purposes of indicating the center of the path for color density measurements of said object samples under test.

15. A densitometer system in accordance with claim 14 characterized in that said guide means further comprises numerical indicia located on a forward edge of a bottom housing of said densitometer system, with said numerical indicia centered with respect to said indicia positioned on said recessed portion, and extending lengthwise across said forward edge, each of said film guides being manually adjustable by an operator for guiding and controlling guidance of said object samples into said densitometer system.

16. A densitometer system in accordance with claim 2 characterized in that said color characteristics include color densities, and:

at least one of said object samples is adapted for use as a calibration reference sample, said calibration reference sample comprising at least one reference color patch and calibration indicating means for indicating previously measured color density values of said reference color patch; and

said densitometer system further comprises calibration means for adjusting slope between low and high color density measurements, said calibration means being adapted to read said calibration indicating means when said calibration reference sample is moved through said densitometer system adjacent said light source means, and to adjust said slope based at least in part on said values of said reference color patch represented by said calibration indicating means.

17. A densitometer system in accordance with claim 16 characterized in that said calibration indicating means comprises a plurality of indicators, and the position of each of said indicators is representative of a particular color density measurement value of said reference color patch.

18. A densitometer system in accordance with claim 16 characterized in that said calibration indicating means comprises a plurality of color indicators and a reference indicator, and the displacement of each of said color indicators relative to said reference indicator is representative of particular color density measurement values of said reference color patch.

19. A densitometer system in accordance with claim 16 characterized in that said calibration indicating means comprising a plurality of color indicators and a reference indicator, wherein the displacement of at least one of said color indicators relative to said reference indicator is representative of a particular color density measurement value of said reference color patch, and the displacement of at least another one of said color indicators relative to said reference indicator is representative of another particular color density measurement value of said reference color patch, but offset by a predetermined value so as to substantially avoid overlap of said plurality of color indicators.

20. A densitometer system in accordance with claim 2 characterized in that said system further comprises means for providing information to said operator as to appropriate positioning of said guide means for guidance of individual ones of said object samples through said densitometer system.

21. A densitometer system adapted for measuring color characteristics of object samples under test, said system comprising:

light source means for generating light rays and directing said light rays onto said object samples;

filter means comprising transmission filter means positioned relative to the direction of object illumination by said light source means, with said transmission filter means being responsive to light rays transmitted through said object samples so as to discriminate a predetermined color shade set of spectral responses of said transmitted light rays;

detection means responsive to light rays transmitted through said filter means for generating signals representative of the intensity of said light rays transmitted through said filter means;

processing means connected to said detection means for processing said signals and for generating data representative of color characteristics of said object samples;

motive means connected to said processing means and adapted to automatically move said object samples through said densitometer system adjacent said light source means, so as to provide and automated measurement of a plurality of color patches associated with said object samples; and

guide means mounted to said densitometer system and adjustable by an operator of said system, so as to provide a guidance in at least one dimension of said object samples through said densitometer system.

22. A densitometer system in accordance with claim 21 characterized in that said filter means further comprises reflection filter means positioned at a predetermined angle relative to the direction of object illumination by said light source means, and said reflection filter means is responsive to light rays reflected from said object samples so as to discriminate a predetermined color shade set of spectral responses of said reflected light rays.

23. A densitometer system in accordance with claim 22 characterized in that said detection means comprises reflection detection means responsive to light rays transmitted through said reflection filter means for generating, on separate paths, reflection signals representative of the intensities of said light rays transmitted through said reflection filter means.

24. A densitometer system in accordance with claim 23 characterized in that said system further comprises reflection multiplexing means connected to said reflection detection means for time multiplexing said reflection signals on said separate paths.

25. A densitometer system in accordance with claim 21 characterized in that said detection means comprises transmission detection means responsive to light rays transmitted through said transmission filter means for generating, on separate paths, transmission signals representative of the intensity of said light rays transmitted through said transmission filter means.

26. A densitometer system in accordance with claim 25 characterized in that said system further comprises transmission multiplexing means connected to said transmission detection means for time multiplexing said transmission signals on said separate paths.

27. A densitometer system in accordance with claim 21 characterized in that said system further comprises multiplexing means connected to said detection means for time multiplexing said signals.

28. A densitometer system in accordance with claim 21 characterized in that said system further comprises display means connected to said processing means for providing visual displays to said operator, indicative of functions performed by said densitometer system.

29. A densitometer system in accordance with claim 21 characterized in that said motive means comprises an electric motor.

30. A densitometer system in accordance with claim 21 characterized in that said guide means comprises a film guide bar having an elongated configuration, and further having nubs or similar elements adapted to be secured into slots located adjacent a forward edge of a bottom housing of said densitometer system.

31. A densitometer system in accordance with claim 30 characterized in that said guide means further comprises a pair of film guide, including a left film guide and a right film guide for capturing said object samples for guidance in at least one dimension into said densitometer system.

32. A densitometer system in accordance with claim 31 characterized in that said guide means further comprises a recessed portion of a housing assembly of said densitometer system, with said recessed portion including indicia for purposes of indicating the center of the path for color density measurements of said object samples under test.

33. A densitometer system in accordance with claim 32 characterized in that said guide means further comprise numerical indicia located on a forward edge of a bottom housing of said densitometer system, with said numerical indicia centered with respect to said indicia positioned on said recessed portion, and extending lengthwise across said forward edge, each of said film guides being manually adjustable by an operator for guiding and controlling guidance of said object samples into said densitometer system.

34. A densitometer system in accordance with claim 21 characterized in that said color characteristics include color densities, and:

at least one of said object samples is adapted for use as a calibration reference sample, said calibration reference sample comprising at least one reference color patch and calibration indicating means for indicating previously measured color density values of said reference color patch; and

said densitometer system further comprise calibration means for adjusting slope between low and high color density measurements, said calibration means being adapted to read said calibration indicating means when said calibration reference sample is moved through said densitometer system adjacent said light source means, and to adjust said slope based at least in part on said values of said reference color patch represented by said calibration indicating means.

35. A densitometer system in accordance with claim 34 characterized in that said calibration indicating means comprises a plurality of indicators, and the position of each of said indicators is representative of a particular color density measurement value of said reference color patch.

36. A densitometer system in accordance with claim 34 characterized in that said calibration indicating means comprises a plurality of color indicators and a reference indicator, and the displacement of each of said color indicators relative to said reference indicator is representative of particular color density measurement values of said reference color patch.

37. A densitometer system in accordance with claim 34 characterized in that said calibration indicating means comprising a plurality of color indicators and a reference indicator, wherein the displacement of at least one of said color indicators relative to said reference indicator is representative of a particular color density measurement value of said reference color patch, and the displacement of at least another one of said color indicators relative to said reference indicator is representative of another particular color density measurement value of said reference color patch, but offset by a predetermined value so as to substantially avoid overlap of said plurality of color indicators.

38. A densitometer system in accordance with claim 21 characterized in that said system further comprises means for providing information to said operator as to appropriate positioning of said guide means for guidance of individual ones of said object samples through said densitometer system.

39. A densitometer system adapted for measuring color characteristics of objects samples under test, said system comprising:

light source means for generating light rays and directing said light rays onto said object samples;

filter means responsive to light rays reflected from said object samples so as to discriminate a predetermined color shade set of spectral responses of said reflected light rays;

detection means responsive to light rays transmitted through said filter means for generating signals representative of the intensity of said light rays transmitted through said filter means;

processing means connected to said detection means for processing said signals and for generating data representative of color characteristics of said object samples under test;

motive means connected to said processing means and adapted to automatically move said object samples under test through said densitometer system adjacent said light source means, so as to provide an automated measurement of a plurality of color patches associated with said object samples;

guide means mounted to said densitometer system and adjustable by an operator of said system, so as to provide a guidance in at least one dimension of said object samples through said densitometer system;

said guide means comprising a film guide bar having an elongated configuration, and further having nubs or similar elements adapted to be secured into slots located adjacent a forward edge of a bottom housing of said densitometer system; and

said guide means further comprising a pair of film guides, including a left film guide and a right film guide for capturing said object samples for guidance in at least one dimension into said densitometer system.

40. A densitometer system in accordance with claim 39 characterized in that said guide means further comprises a recessed portion of a housing assembly of said densitometer system, with said recessed portion including indicia for purposes of indicating the center of the path for color density measurements of said object samples under test.

41. A densitometer system in accordance with claim 40 characterized in that said guide means further comprises numerical indicia located on a forward edge of a bottom housing of said densitometer system, with said numerical indicia centered with respect to said indicia positioned on said recessed portion and extending lengthwise across said forward edge, each of said film guides being manually adjustable by an operator for guiding and controlling guidance of said object samples into said densitometer system.

43. A densitometer system in accordance with claim 40 characterized in that said calibration indicating means comprises a plurality of indicators, and the position of each of said indicators is representative of a particular color density measurement value of said reference color patch.

42. A densitometer system adapted for measuring color characteristics of object samples under test, said system comprising:

light source means for generating light rays and directed said light rays onto said object samples;

filter means responsive to light rays reflected from said object samples so as to discriminate a predetermined color shade set of spectral responses of said reflected light rays;

detection means responsive to light rays transmitted through said filter means for generating signals representative of the intensity of said light rays transmitted through said filter means;

processing means connected to said detection means for processing said signals and for generating data representative of color characteristics of said object samples under test;

motive means connected to said processing means and adapted to automatically move said object samples under test through said densitometer system adjacent said light source means, so as to provide an automated measurement of a plurality of color patches associated with said object samples;

guide means mounted to said densitometer system and adjustable by an operator of said system, so as to provide a guidance in at least one dimension of said object sample through said densitometer system;

said color characteristics include color densities, and at least one of said object samples is adapted for use as a calibration reference sample, said calibration reference sample comprising at least one reference color patch and color indicating means for indicating previously measured color density values of said reference color patch; and

said densitometer system further comprises calibration means for adjusting slope between low and high color density measurements, said calibration means being adapted to read such calibration indicating means when said calibration reference sample is moved through said densitometer system adjacent said light source means, and to adjust said slope based at least in part on said values of said reference color patch represented by said calibration indicating means.

44. A densitometer system in accordance with claim 42 characterized in that said calibration indicating means comprises a plurality of color indicators and a reference indicator, and the displacement of each of said color indicators relative to said reference indicator is representative of particular color density measurement values of said reference color patch.

45. A densitometer system in accordance with claim 42 characterized in that said calibration indicating means comprises a plurality of color indicators and a reference indicator, wherein the displacement of at least one of said color indicators relative to said reference indicator is representative of a particular color density measurement value of said reference color patch, and the displacement of at least another one of said color indicators relative to said reference indicator is representative of another particular color density measurement value of said reference color patch, but offset by a predetermined value so as to substantially avoid overlap of said plurality of color indicators.