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US5636637A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for determining quantities characteristic of the behavior of a surface, in particular of the human skin, subjected to light radiation, and apparatus for implementation thereof

Assignee: L'Oréal SA
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Filing: 1995-05-17
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Granted: 1997-06-10
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Expires: 2015-05-17
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Abstract

Abstract A method and apparatus determine quantities characteristic of the behavior of a surface, in particular, the human skin, subjected to light radiation. The apparatus includes an illumination device, a measurement detection device and a computation device. The apparatus and method determine a scattering spectrum, and calculate one or more quantities characteristic of the surface in a predetermined range of wavelengths.

Inventors

  • 👤 Alain Guiolet
  • 👤 Jean De Rigal
  • 👤 Jean-Luc Leveque

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 15:30
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/44; A61B5/441; A61B5/445; A61B5/0059

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 139 words
A method for determining quantities characteristic of the behavior of a surface subjected to light radiation, comprising: illuminating a predetermined region of a surface with a polarized light beam oriented along an incidence direction which makes, with the normal to the surface, an angle of between 20° and 50°; recovering a scattering light signal originating from the predetermined region and oriented along the normal to the surface by filtering the scattering light signal through a polarizer whose polarization direction is perpendicular to the polarization direction of the light beam; obtaining a scattering spectrum by measuring the scattering light signal and by sweeping a predetermined range of wavelengths of the polarized light beam; and calculating on the basis of the scattering spectrum, at least one quantity characteristic of an optical behavior of the surface in the predetermined range of wavelengths.
Claim 2
Independent Claim 139 words
A method for determining quantities characteristic of the behavior of a surface subjected to light radiation, comprising: illuminating a predetermined region of a surface with a polarized light beam oriented along an incidence direction which makes, with the normal to the surface, an angle of between 20° and 50°; recovering a scattering light signal originating from the predetermined region and oriented along the normal to the surface by filtering the scattering light signal through a polarizer whose polarization direction is perpendicular to the polarization direction of the light beam; obtaining a scattering spectrum by measuring the scattering light signal and by sweeping a predetermined range of wavelengths of the polarized light beam; and calculating on the basis of the scattering spectrum, at least one quantity characteristic of an optical behavior of the surface in the predetermined range of wavelengths.
Claim 3
Dependent Claim 36 words
The method according to claim 1, wherein the orientation of polarization of the light beam is parallel to an incidence plane, said incidence plane being defined by said incidence direction and said normal to the surface.
Claim 4
Dependent Claim 135 words
The method according to claim 2, further comprising: recovering a second, specular light signal originating from the predetermined region along a direction which is symmetrical to the incidence direction of the light beam with respect to the normal to the surface by filtering a collected signal through a polarizer whose polarization direction is parallel to the polarization direction of the light beam; obtaining a specular spectrum by measuring the second, specular light signal and by sweeping a predetermined range of wavelengths of the light beam; determining a pseudo-luminance spectrum by sampling the scattering spectrum and the specular spectrum; and calculating, for each interval of the sampling, a ratio between the specular signal and the scattering signal, wherein the pseudo-luminance spectrum is characteristic of an optical behavior of the surface in the predetermined range of wavelengths.
Claim 5
Dependent Claim 116 words
The method according to claim 3, wherein said predetermined region of a surface is a predetermined region of bare skin; and wherein said illuminating, recovering, obtaining and calculating steps are performed on the same region of bare skin before and after said bare skin has been covered with a film of a sun product, and the method further comprises: comparing the two pseudo-luminance spectra; obtaining for each interval i in the sampling, a pseudo-luminance variance DB i ; and calculating a value I characteristic of the protection efficiency of the product according to the following formula: ##EQU7## where α i is an erythemal efficiency coefficient in the interval in question, and K i is a weighting.
Claim 6
Dependent Claim 51 words
The method according to claim 2, further comprising determining back scattering energy ERD according to the following formula: ##EQU8## where ED i is a signal measured in the scattering spectrum for an interval i of the sampling, α i is an erythemal efficiency coefficient and K i is a simulation weighting.
Claim 7
Dependent Claim 135 words
The method according to claim 1, further comprising: recovering a second, specular light signal originating from the predetermined region along a direction which is symmetrical to the incidence direction of the light beam with respect to the normal to the surface by filtering a collected signal through a polarizer whose polarization direction is parallel to the polarization direction of the light beam; obtaining a specular spectrum by measuring the second, specular light signal and by sweeping a predetermined range of wavelengths of the light beam; determining a pseudo-luminance spectrum by sampling the scattering spectrum and the specular spectrum; and calculating, for each interval of the sampling, a ratio between the specular signal and the scattering signal, wherein the pseudo-luminance spectrum is characteristic of an optical behavior of the surface in the predetermined range of wavelengths.
Claim 8
Dependent Claim 116 words
The method according to claim 6, wherein said predetermined region of a surface is a predetermined region of bare skin, and wherein said illuminating, recovering, obtaining and calculating steps are performed on the same region of bare skin before and after said bare skin has been covered with a film of a sun product; and the method further comprises: comparing the two pseudo-luminance spectra; obtaining for each interval i in the sampling, a pseudo-luminance variance DB i ; and calculating a value I characteristic of the protection efficiency of the product according to the following formula: ##EQU9## where α i is an erythemal efficiency coefficient in the interval in question, and K i is a weighting.
Claim 9
Dependent Claim 51 words
The method according to claim 1, further comprising determining back scattering energy ERD according to the following formula: ##EQU10## where ED i is a signal measured in the scattering spectrum for an interval i of the sampling, α i is an erythemal efficiency coefficient and K i is a simulation weighting.
Claim 10
Dependent Claim 12 words
The method according to claim 1, wherein the surface is human skin.
Claim 11
Dependent Claim 30 words
The method according to claim 1, wherein the polarized light beam is oriented along an incidence direction which makes, with the normal to the surface, an angle of approximately 35°.
Claim 12
Independent Claim 193 words
An apparatus for determining qualities characteristic of behavior of a surface subjected to light radiation, the apparatus comprising: an applicator head; a light source connected to said applicator head, said light source being adapted to send an incident light beam onto a region of the surface; a first polarizer positioned between the light source and the region, said first polarizer polarizing said light beam and the light beam forming, with the normal to the surface, an angle of between 10° and 50°; a light-signal detector connected to said applicator head and oriented so as to collect light originating from the region along the normal to the surface; a second polarizer whose polarization direction is perpendicular to the polarization direction of the light beam, said second polarizer being positioned between the region and said light-signal detector; means for obtaining a scattering spectrum by sweeping a predetermined range of wavelengths of the light beam; means for measuring the light collected by the detector; and computation means for calculating on the basis of the said scattering spectrum one or more quantities which are characteristic of optical behavior of the surface in a predetermined range of wavelengths.
Claim 13
Independent Claim 193 words
An apparatus for determining qualities characteristic of behavior of a surface subjected to light radiation, the apparatus comprising: an applicator head; a light source connected to said applicator head, said light source being adapted to send an incident light beam onto a region of the surface; a first polarizer positioned between the light source and the region, said first polarizer polarizing said light beam and the light beam forming, with the normal to the surface, an angle of between 10° and 50°; a light-signal detector connected to said applicator head and oriented so as to collect light originating from the region along the normal to the surface; a second polarizer whose polarization direction is perpendicular to the polarization direction of the light beam, said second polarizer being positioned between the region and said light-signal detector; means for obtaining a scattering spectrum by sweeping a predetermined range of wavelengths of the light beam; means for measuring the light collected by the detector; and computation means for calculating on the basis of the said scattering spectrum one or more quantities which are characteristic of optical behavior of the surface in a predetermined range of wavelengths.
Claim 14
Dependent Claim 52 words
The apparatus according to claim 11, wherein the first polarizer is positioned between the light source and the region and is oriented so that the polarization direction of the incident beam is parallel to an incidence plane, said incidence plane being defined by said incidence direction and said normal to the surface.
Claim 15
Dependent Claim 18 words
The apparatus according to claim 12, wherein the applicator head comprises reference means for orienting the applicator head.
Claim 16
Dependent Claim 78 words
The apparatus according to claim 13, wherein said reference means comprises a mask which can be applied directly onto the region, said mask comprising a masking element provided with an orifice of asymmetric shape; wherein said applicator head comprises a central part of the same shape as said orifice, said central part cooperating with said orifice when said apparatus is applied onto the region; and wherein adhesive supports are connected to said masking element by removable, fastening means.
Claim 17
Dependent Claim 11 words
The apparatus according to claim 14, wherein the orifice is square.
Claim 18
Dependent Claim 30 words
The apparatus according to claim 13, wherein the reference means make it possible to apply the applicator head onto a surface of skin while always maintaining the same incidence plane.
Claim 19
Dependent Claim 18 words
The apparatus according to claim 11, wherein the applicator head comprises reference means for orienting the applicator head.
Claim 20
Dependent Claim 78 words
The apparatus according to claim 17, wherein said reference means comprises a mask which can be applied directly onto the region, said mask comprising a masking element provided with an orifice of asymmetric shape; wherein said applicator head comprises a central part of the same shape as said orifice, said central part cooperating with said orifice when said apparatus is applied onto the region; and wherein adhesive supports are connected to said masking element by removable fastening means.
Claim 21
Dependent Claim 11 words
The apparatus according to claim 18, wherein the orifice is square.
Claim 22
Dependent Claim 44 words
The apparatus according to claim 17, wherein the reference means make it possible to apply the applicator head onto a surface of skin while always maintaining an incidence plane, said incidence plane being defined by said incidence direction and said normal to the surface.
Claim 23
Dependent Claim 12 words
The apparatus according to claim 11, wherein the surface is human skin.
Claim 24
Dependent Claim 22 words
The apparatus according to claim 11, wherein the light beam forms, with the normal to the surface, an angle of approximately 35°.

References Cited (Backward Citations)

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US4905702A Cited
DE3827457A1 Cited
FR2650890A1 Cited
FR2651112A1 Cited
GB2235767A Cited
EP0475803A1 Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-06-09 2000-12-09 2001-06-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-06-09 2004-12-09 2005-06-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-06-09 2008-12-09 2009-06-10 $7700.00 Window Closed / Lapsed

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