Process and apparatus for making a numerical determination of the color, or of a change in color, of an object

• US 4,616,933 A
• Filed: 03/27/1984
• Issued: 10/14/1986
• Est. Priority Date: 09/13/1979
• Status: Expired due to Fees

• Current Assignee: L'Oreal SA
• Original Assignee: L'Oreal SA
• Inventors: Leveque, Jean-Luc M., Gras, Gilbert J.
• Primary Examiner(s): McGraw, Vincent P.
• Application Number:
  US06/593,882
• Time in Patent Office: 931 Days
• Field of Search: 356/445-448, 356/402, 356/408, 356/416, 356/418, 356/425, 250/227
• US Class Current: 356/416
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/445 Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• CPC Class Codes: G01N 21/55 Specular reflectivity

Abstract

A coaxial optical fiber bundle assembly (Reference No. 6 in the following Specification and Drawing), carrying emitted light from a light source and received light which has been returned by an object illuminated from said light source, is moved towards the object (Reference No.: 7) to cause the intensity of the received light, as detected by a photo transistor in light emitter-receiver unit (Reference No.: 1), to attain a maximum value which is amplified and held as a display on digital voltmeter (Reference No.: 11). Comparison of the held value with the corresponding held maximum value resulting from a similar determination made of either a different object of the same object after a color change therein or thereof can thus be made on a numerical basis.

Claims

1. Apparatus for making numerical-determination of one of the colors or of a change in a given color of an object, which apparatus is comprised of:

(a) a source of light to irradiate the object whose numerical-determination of color is desired and to be found;

(b) a photo transducer measn to pick up the light returned by the object;

(c) optical fiber receiving means to direct the light returned by the object to the said photo transducer means;

with

the said optical fiber receiving means having an end that is displaceable substantially perpendicularly to the said object being investigated whose numerical-determination of color is desired and to be found in order to obtain such desired determination;

(d) optical fiber emitter means having an end to direct the emission of said light source to a said object being investigated, said optical fiber receiving means and said emitter means being coaxially disposed at least at said ends to provide coaxial ends and to provide first and second optical fiber bundles;

with

said optical fiber emitter means and said optical fiber receiving means being disposed as a unit to be passed within and to make traversing entry substantially perpendicularly into a zone of access wherein is located the object to be investigated;

(e) signal processing means for determining the value of the maximum of the signal supplied by the photo transducer means during the displacement of the said optical receiver means;

with said signal processing means including means to provide said maximum signal value determination substantially instantaneously at the time during displacement of the said end of the optical receiving means when said receiving means is at least in very near maximum signal-generating proximity of contact with said object to be investigated; and

(f) a display unit responsive to said signal processing means for substantially instantaneously displaying information according to the determination made;

with

(g) means associated with said apparatus assembly for moving said coaxial ends of said first and second optical fiber bundles in said unit towards and away from said object.

2. Apparatus according to claim 1, wherein:

said optical fiber emitter means and optical fiber receiver means comprise first and second optical fiber bundles having coaxial ends in the same plane substantially parallel to the object,

the said ends being displaceable together substantially perpendicularly to the object to the effect the desired determination.

3. Apparatus according to claim 1, wherein:

the said photo transducer means further comprises an optical filter.

4. Apparatus according to claim 3, wherein:

said optical filter has a spectral distribution which approximates to that which corresponds to the sensitivity of the human eye.

5. Apparatus according to any one of claims 1-4, inclusive, wherein:

said signal processing means includes a peak detector means and an analogue memory.

6. Apparatus according to claim 5, wherein:

said signal processing means further includes

an analogue/digital and digital/analogue converter having an output which feeds said display unit and an input which feeds said display unit and an input connected to the said peak detector means.

7. Apparatus according to claim 6, wherein:

said display unit comprises a voltmeter.

8. Apparatus according to claim 6, wherein:

said signal processing means further includes means to obtain a signal proportional to the output signal of said peak detector means, and means establishing a proportionality coefficient being less than 1; and

comparator means comparing the said proportional signal and the output signal of said photo transducer means whereby and wherein

as soon as the two compared signals are equal, said comparator initiates the resetting of the converter to zero as well as the start of a first timed period at the end of which there is produced a resetting to zero of said peak detector and the commencement of a second timed period at the end of which said display unit is reset to zero.

9. Apparatus according to claim 7, wherein:

said signal processing means further includes means to obtain a signal proportional to the output signal of said peak detector means, the proportionality coefficient being less than 1; and

comparator means comparing the said proportional signal and the output signal of said photo transducer means whereby and wherein

as soon as the two compared signals are equal, said comparator initiates the resetting of the converter to zero as well as the start of a first timed period at the end of which there is produced both a resetting to zero of said peak detector and the commencement of a second timed period at the point of which said display unit is reset to zero.

10. Apparatus according to any one of claims 1-4, which is usable for examining the skin, wherein

said light source is one which emits light practically completely in the visible spectrum with a maximum in yellow.

11. Apparatus according to claim 5, which is usable for examining the skin, wherein

said light source is one which emits light practically completely in the visible spectrum with a maximum in yellow.

12. Apparatus according to claim 6 which is usable for examining the skin, wherein:

said light source is one which emits light practically completely in the visible spectrum with a maximum in yellow.

13. Apparatus according to claim 7 which is usable for examining the skin, wherein:

said light source is one which emits light practically completely in the visible spectrum with a maximum in yellow.

14. Apparatus according to claim 8 which is usable for examining the skin, wherein:

said light source is one which emits light practically completely in the visible spectrum with a maximum in yellow.

15. Apparatus according to claim 9 which is usable for examining the skin, wherein:

said light source is one which emits light practically completely in the visible spectrum with a maximum in yellow.

16. A process for making a numerical determination of one of the colors, and a change in a given color, of an object which comprises the Steps of:

(I) taking an apparatus characterized in therein having

(a) a source of light to irradiate the object whose numerical-determination of color is desired and to be found;

(b) a photo transducer means to pick up the light returned by the object;

(c) optical fiber receiving means to direct the light returned by the object to the said photo transducer means;

with

the said optical fiber receiving means having an end that is displaceable substantially perpendicularly to the said object being investigated whose numerical-determination of color is desired and to be found in order to obtain such desired determination;

(d) optical fiber emitter means having an end to direct the emission of said light source to a said object being investigated, said optical fiber receiving means and said emitter means being coaxially disposed at least at said ends to provide coaxial ends and to provide first and second optical fiber bundles;

with

said optical fiber emitter means and said optical fiber receiving means being disposed as a unit to be passed within and to make traversin entry substantially perpendicularly into a zone of access wherein is located the object to be investigated;

(e) signal processing means for determining the value of the maximum of the signal supplied by the photo receiver (b) during the displacement of the said end of the optical receiver means (c);

with

said signal processing means for determining the value of the maximum of the signal supplied by the photo transducer means during the displacement of the said optical receiver means;

with said signal processing means including means to provide said maximum signal value determination substantially instantaneously at the time during displacement of the said end of the optical receiving means when said receiving means is at least in very near maximum signal-generating proximity of contact with said object to be investigated; and

(f) a display unit responsive to said signal processing means for substantially instantaneously displaying information according to the determination made; and

therewith

(II) moving said coaxial ends of said first and second optical fiber bundles in said receiving means and said emitter means towards the said object;

while

(III) receiving the light from said light source return from the said object;

then

(IV) processing the output signal of said photo transducer means using the detector circuit in said signal processing means; and

(V) displaying substantially instantaneously the output of said detector circuit in said signal processing means using for such purpose the display unit.

17. A process according to claim 16, when carried out:

using an optical filter in the path of the said returned light picked up from the illuminated object,

said optical filter having a medium wave length which approximates to the wave length corresponding to the normal unmodified color of the object being investigated.