Field balancing may be performed with an irradiation system including a plurality of adjustable radiant-energy emitters. The irradiation system powers the radiant-energy emitters from a power source and radiant energy is emitted from the radiant-energy emitters, where an amount of radiant energy emitted from each emitter is capable of being varied based on power received from the power source. A plurality of radiant-energy sensors detects an amount of radiant energy which includes radiant energy created directly by at least one of the radiant-energy emitters. The amount of radiant energy detected at at least two of the radiant-energy sensors is compared, and at least one of the radiant-energy emitters is adjusted by varying the power received from the power source so that the amount of radiant energy detected at each of the radiant-energy sensors tends towards becoming approximately equal. The emitting of radiant energy from each radiant-energy emitter is terminated when a total amount of radiant energy emitted from the plurality of adjustable radiant-energy emitters exceeds a predetermined threshold value, where the threshold value is sufficient to allow the total amount of radiant energy emitted from the plurality of adjustable radiant-energy emitters to sanitize a particular area in which the emitters are located.

Systems and methods for emitting radiant energy

A system that incorporates teachings of the present disclosure may include, for example, a method for aligning first and second light signals on an optical path directed to a target, where the first light signal provides a visualization of the target, and a portion of the second light signal reflects from at least one subsurface of the target. The method also includes aligning a first focal point of the first light signal and a second focal point of the second light signal, where the first focal point is at least in a first proximate location of the second focal point, and adjusting a first position of the first and second focal points to be in at least a second proximate location of the target without adjusting the at least first proximate location of the first focal point relative to the second focal point. Other embodiments are disclosed.

Method and apparatus for analyzing subsurfaces of a target material

A hair treatment device is provided comprising alight-based detector (10) for detecting a hair (11) near a skin (12) surface. The light-based detector comprises a light source (13) for emitting optical radiation of at least a first wavelength and with an incident polarization towards the skin surface. A light sensor (14a, 14b) is provided for detecting light reflected at the skin surface. The light sensor (14a, 14b) is capable of separately detecting the reflected light with the incident polarization and with a different polarization and for providing a PP value representing the detected light with the incident polarization and a CP value representing the detected light with the different polarization. A processor (15) is operative to scale the CP value and the PP value to respective dynamic ranges, to determine a Minimum Intensity Projection (MIP) value by selecting the lowest value of the scaled CP value and the scaled PP value and to discriminate between the skin surface (12) and the hair (11) based on the minimum intensity projection.

Hair treatment device having a light-based hair detector

A method for measuring visual appearance of birefringent fibers is disclosed. The method involves emitting light, creating N polarization states of the emitted light, wherein the polarized emitted light illuminates the birefringent fibers, thereby generating internal reflection components, external reflection components, and diffusion components of the light, observing the light from the illuminated birefringent fibers, creating N polarization states of the observed light, forming N images of the observed polarized light, each image comprising a plurality of pixels, measuring the intensity in each pixel of the N images, and for each pixel, separating the internal reflection component, the external reflection component, and the diffusion component from the i-th image for the N images, wherein i=1, 2, . . . N and N≧4.

Visual appearance measurement method and system for randomly and regularly arranged birefringent fibers

The invention provides a hair treatment device (40) comprising a light-based detector (10) for detecting a hair (22) near a skin surface (21) and a method for detecting a hair (22) near a skin surface (21). The detector (10) comprises a light source (11), optical elements (14, 16, 17, 18) and a polarization-sensitive light sensor (12, 13). The light source (11) generates a light beam (31) and the optical elements (14, 16, 17, 18) focus the light beam (31) at a hair (22) near the skin surface (21). The polarization-sensitive light sensor (12, 13) is provided for detecting light interacted with the hair (22) or the skin surface (21) and having a predefined linear polarization. The light source (11) and/or the optical elements (14, 16, 17, 8) are arranged to cause the light beam (31), when reaching the skin surface (21), to have a polarization direction which is time-invariant and spatially variant in cross-sections of the 10 light beam.

Hair treatment device with hair detector

Methods and apparatus to determine the orientation of randomly arranged birefringent fibers are disclosed. One method comprises emitting light, creating N i polarization states of the emitted light, illuminating the birefringent fibers with the emitted light so polarized, thereby generating IR i internal reflection components of the light in the birefringent fibers, observing the light from the illuminated birefringent fibers, creating O i polarization states of the observed light, forming I i images of the observed polarized light, each image comprising an information (N i , O i , IR i ), wherein i=1, 2, . . . , n and n≧3, separating the i-th internal reflection component from the i-th image, and calculating an angle of a neutral axis of the birefringent fibers using the IR i internal reflection components.

Birefringent fibers orientation measurement

Methods and apparatus to measure visual appearance of randomly arranged birefringent fibers are disclosed. One method comprises emitting light, creating N i polarization states of the emitted light, illuminating the birefringent fibers with the emitted light so polarized, thereby generating IR i internal reflection components, ER i external reflection components, and D i diffusion components of the light in the birefringent fibers, observing the light from the illuminated birefringent fibers, creating O i polarization states of the observed light, forming X i images of the observed polarized light, each image comprising an information (N i , O i , IR i , ER i , D i ), wherein i=1, 2, . . . n and n≧4, measuring the intensity I i in each pixel in the X, images, and separating the i-th internal reflection component, the i-th external reflection component, and the i-th diffusion component from the i-th image for the X i images.

Visual appearance measurement method and system for randomly arranged birefringent fibers

Along with intensity and spectrum, the polarization of light carries abundant information Polarization imaging has established strong interest for visual appearance measurement, based on its ability to analyze scattered light and for defense applications, thanks to its performances in term of object detection/identification Image contrast enhancement and information on the objects (natural, man-made, detection of water bodies, 3D shape) composing the scene can also be derived from the polarization analysis In this paper, we will present an innovative polarization component based on ceramic PLZT and its integration in an imaging system It will lead to a passive polarization camera that will measure the 4 Stokes parameters for each pixel of the image, in real-time, without any mechanical rotation and at high frame per second Based on PLZT ceramic, we will present the design and the manufacturing of a rotatable and programmable waveplate It will be the key component of a passive polarization imaging system The component will be optimized, fabricated and integrated into a passive polarization camera The performances of the polarization camera will be demonstrated in the laboratory Measurement of Stokes vector for each pixel of the image will allow precise polarization measurement, leading to accurate analysis of the scattered light Various parameters (gloss, color) and images (polarization degree, surface scattering, volume scattering) will be calculated from the Stokes parameters

Bruno Francois Pouet

Papers

Birefringent fibers orientation measurement

Visual appearance measurement method and system for randomly arranged birefringent fibers

Visible Stokes imaging using programmable waveplate based on PLZT ceramic