Light weight appliance to be used with smart devices to produce shortwave infrared emission
10859239 ยท 2020-12-08
Assignee
Inventors
- Reuven Schmerling (Amherst, MA, US)
- William R. Palmer (Rescue, CA, US)
- Stephen L. Palmer (Cameron Park, CA, US)
Cpc classification
F21V9/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
G02B5/208
PHYSICS
F21V9/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21V17/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F21V9/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21V9/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A short wavelength infrared (SWIR) energy emitting unit, and device having a SWIR emitting unit, for producing SWIR energy from an emission source emitting electromagnetic energy. The SWIR energy unit comprises a phosphor material, an electromagnetic energy blocking member, a substrate for delivering the system or material to an electromagnetic energy emission source, and optionally, an attachment member.
Claims
1. A short-wavelength infrared energy producing unit configured to affix to a device capable of emitting at least one source of electromagnetic energy comprising: a substrate material securable to said device capable of emitting at least one source of electromagnetic energy through a frictional fit attachment member comprising a plurality of walls formed together to partially enclose an interior region, said interior region sized and shaped to receive or engage with at least a portion of a device having a source for emitting ultraviolet or visible light; a phosphor layer; and an electromagnetic energy blocking layer; said frictional fit attachment member comprises an opening of sufficient size to allow emission of electromagnetic energy from said at least one source of electromagnetic energy on one first, front wall and said phosphor layer and said electromagnetic energy blocking layer positioned on an opposite, second, back wall.
2. The short-wavelength infrared energy producing unit configured to affix to a device capable of emitting at least one source of electromagnetic energy according to claim 1, further including an attachment member.
3. The short-wavelength infrared energy producing unit configured to affix to a device capable of emitting at least one source of electromagnetic energy according to claim 2, wherein said attachment member includes a pressure sensitive adhesive.
4. The device for producing short-wavelength infrared emissions according to claim 1, further including a protective shield.
5. The device for producing short-wavelength infrared emissions according to claim 4, wherein said protective shield is made of an optically transmissive material.
6. The short-wavelength infrared energy producing unit according to claim 1, wherein said phosphor is contained in a binder or carrier.
7. The short-wavelength infrared energy producing unit according to claim 1, wherein said electromagnetic energy blocking layer is one or more wavelength-blocking optical filters configured to at least partially block emissions of NIR light, visible light, or combinations thereof.
8. The device for producing short-wavelength infrared emissions according to claim 1, wherein said electromagnetic energy blocking layer is a NIR or visible light filter configured to render said device capable of emitting at least one source of electromagnetic energy invisible to a NIR or visible light detection system or sensor.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
(17) While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described, a presently preferred, albeit not limiting, embodiment with the understanding that the present disclosure is to be considered an exemplification of the present invention and is not intended to limit the invention to the specific embodiments illustrated.
(18) The present invention is directed towards a short-wavelength infrared energy producing unit configured to affix to a device capable of emitting at least one source of electromagnetic energy, preferably visible or ultraviolet light, and a device having at least one source for emitting electromagnetic energy having or utilizing the short-wavelength infrared energy producing unit, both referred to generally as SWIR energy producing unit 10. The SWIR energy producing unit 10 comprises a phosphor material layer; an electromagnetic energy blocking member layer; a substrate layer for delivering the unit to an emission source, and optionally, an attachment member. The phosphor allows the SWIR energy producing unit 10 to emit SWIR, preferably when excited at its absorption wavelengths associated with visible or ultraviolet light.
(19) Phosphors that are capable of producing SWIR energy when exposed to visible light are known. For example, the SWIR energy producing unit 10 may use one or more rare-earth phosphors, i.e. lanthanides (those chemicals listed on the chemical table having atomic numbers from 57-71, including Lanthanum, (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), and Lutetium (Lu)), as well as Scandium and Yttrium. The term phosphors, as used herein, also includes engineered fluorescers, such as quantum dots. Illustrative examples of the desired phosphor preferably emit energy at various wavelengths of between about 1000 nm and about 3000 nm. One illustrate example may be the phosphor which produces a Nd:YAG laser. As used herein, the term about or approximately means plus or minus 10% of the stated value.
(20) One particular phosphor is capable of emitting energy at various wavelengths between about 1400 nm and 1600 nm, when properly excited at its absorption wavelengths of between about 400 nm and about 800 nm. Referring to
(21) Many smart devices now have built-in cameras. In addition to the relatively low power LEDs in the data display screen, these devices also have built-in white light illuminators to provide light to the scene to be photographed. These light sources are most commonly very bright white LEDs. This light is rich in visible red light, as well as light of other wavelengths that can effectively excite a SWIR emitting phosphor. The spectra of the white light illuminator in an Apple iPhone 5S camera flash is shown in
(22) As can be seen from
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(25) Preferably, the SWIR energy producing unit 10 is designed to produce a SWIR energy emitting source that does not also produce visible or NIR emission. It is desirable that any visible or NIR emissions be blocked with a suitable filter. This filter, preferably, is at least partially transparent to the SWIR energy of interest so that this energy may be usefully emitted from the device. A selective wavelength filter element may be created using a combination of organic or other dyes, such as anthraquinones, dianthrones, cyanines, heteroaromatics, metal dithiolenes, perylenes, phthalocyanines, rhodamines, tetraaryldiamines, thiazines, triarylamines, or triarylmethanes. The dyes may be incorporated into a substrate or carrier, such as a plastic resin, including plastisol, organisol, or other materials which will form a solid solution (a solid-state solution of one or more solutes in a solvent) in which the dye is efficiently dispersed. The dyes and any carrier or support resin must permit the transmission of SWIR energy so that useful energy can leave the device. Similarly, a thin-film filter, such as a dielectric filter, may be utilized to block visible and NIR energy while permitting the SWIR energy to pass. A combination of these and other filter types may also be advantageously employed.
(26) The SWIR energy producing unit 10 then comprises a light-weight and convenient means of producing SWIR energy from existing visible energy sources.
EXAMPLES
(27) Referring to
(28) Referring again to the embodiment shown in
(29) For SWIR photoluminescence, one or more lanthanide ions (Ln.sup.3+) may be used, as known in the art, see Liang, et al., J. Mater Chem C, 2017, 5, 6488. The phosphor layer 13 used in this embodiment may be designed to contain the phosphor in a binder/carrier. A preferred, albeit non-limiting, binder/carrier utilized was product 3426, a UV cured urethane-based ink base from Nazdar (Shawnee, Kans.). This type of material provided good transparency to the excitation light and bonded exceptionally well to a variety of substrates, including 3M's 764 adhesive tape product (3M Maplewood, Minn.). The material is tough and flexible after curing, allowing the finished product to be stretched and flexed without damage. It was found that the bond between the 3426 and the 764 products was both a mechanical bond and a chemical bond. Preferably, the dry powdered phosphor was mixed into the un-cured urethane product to form a slurry at concentrations of about 0.5% to concentrations of about 50% (W/W), depending on the SWIR conversion efficiency and SWIR output desired for any given application. The slurry was then deposited onto the substrate, for example 3M product 764, in a controlled thickness, and later cured by application of ultraviolet light. After curing, a preferred, albeit not limiting, thicknesses of between 0.001 to about 0.080 was determined to be functional for the application.
(30) An illustrative example of an effective VIS/NIR filter 15 for use in the boot embodiment was created using a commercial product referred to as SPECTRE 160 (visibly-opaque IR transmitting (VOIRT) screen ink, absorbs 200-1065 nm, transmits >1165 nm), available from Epolin, Inc. (Newark, N.J.). The SPECTRE 160 was supplied in the form of an air dry, viscous ink that could be screen printed, or, alternately, applied in a controlled thickness layer by the use of doctor blades. In an illustrative example, the VIS/NIR filter layer was applied directly over the phosphor layer. After curing, the preferred thicknesses were between 0.0005 to about 0.020, although other thicknesses worked as well.
(31) A second (dye) product EPOLIGHT 7527G (visible opaque dye, blocks light from 200 nm to 1065 nm), also from Epolin, can be used to produce a suitable VIS/NIR filter. This dye was supplied as a powder, and used by incorporating it into a suitable carrier which serves to both disperse the dye and bond it to a substrate, typically the phosphor layer 13. A suitable carrier may be, for example, a solvent-based, SWIR transparent paint base such as Nazdar's S226 clear mixing base.
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(33) The SWIR energy producing boot 10B, which may act as a frictional fit member, may comprise two opposing side walls 31 and 33, a front wall 35 and a back wall 37, see
(34) The SWIR energy producing boot 10B was found to function well and produce significant SWIR emission when placed on an Apple iPhone. The phosphor layer used in this embodiment may be designed to contain the phosphor in a binder/carrier. A preferred, albeit non-limiting, binder/carrier utilized was product 3426, a UV cured urethane-based ink base from Nazdar (Shawnee, Kans.). This type of material provided good transparency to the excitation light and bonded exceptionally well to a variety of substrates, including 3M's 764 adhesive tape product (3M Maplewood, Minn.). The material is tough and flexible after curing, allowing the finished product to be stretched and flexed without damage.
(35) It was found that the bond between the 3426 and the 764 products was both a mechanical bond and a chemical bond. Preferably, the dry powdered phosphor was mixed into the un-cured urethane product to form a slurry at concentrations of about 0.5% to concentrations of about 50% (W/W), depending on the SWIR conversion efficiency and SWIR output desired for any given application. The slurry was then deposited onto the substrate, for example 3M product 764, in a controlled thickness, and later cured by application of ultraviolet light. After curing, a preferred, albeit not limiting, thicknesses of between 0.001 to about 0.080 was determined to be functional for the application.
(36) An illustrative example of an effective VIS/NIR filter 15 for use in the SWIR energy producing boot 10B embodiment was created using a commercial product referred to as SPECTRE 160 (visibly-opaque IR transmitting (VOIRT) screen ink, absorbs 200-1065 nm, transmits >1165 nm), available from Epolin, Inc. (Newark, N.J.). The SPECTRE 160 was supplied in the form of an air dry, viscous ink that could be screen printed, or, alternately, applied in a controlled thickness layer by the use of doctor blades. In an illustrative example, the VIS/NIR filter layer 15 was applied directly over the phosphor layer 13. After curing, the preferred thicknesses were between 0.0005 to about 0.020, although other thicknesses worked as well.
(37) A second (dye) product EPOLIGHT 7527G (visible opaque dye, blocks light from 200 nm to 1065 nm), also from Epolin, can be used to produce a suitable VIS/NIR filter 15. This dye was supplied as a powder and used by incorporating it into a suitable carrier, which serves to both disperse the dye and bond it to a substrate, typically the phosphor layer 13. A suitable carrier may be, for example, a solvent-based, SWIR transparent, paint base such as Nazdar's S226 clear mixing base.
(38) While the phosphor layer 13 and the VIS/NIR filter 15 were formed separately, both the phosphor containing element and the VIS/NIR filter element could alternately utilize a two-part, urethane-based material, such as BJB WC565, from BJB Enterprises (Tustin, Calif.). The WC565 material is a water clear urethane rubber product that cures after combining an A and B component. This WC565 material is highly transmissive in the excitation band of the phosphor, as well as being highly transmissive to SWIR energy. Because both the SWIR producing element and the VIS/NIR filter element were produced using the same base material, insert molding a cured SWIR producing element directly into the VIS/NIR filter portion of the device while obtaining excellent adhesion between the two elements was possible. The cured products were tough and flexible, curing to a hardness of approximately SHORE A65. Concentrations of the phosphor and VIS/NIR blocker dye can vary widely depending on the thickness of the respective elements and the desired SWIR production and VIS/NIR light blockage.
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(40) The elastic nature of the band 19 permits it to be readily affixed to smart devices of varying sizes and shapes. Once again, the VIS/NIR filter 15 may comprise the entire outermost surface of the band, or may be limited to the region of the device in which SWIR energy must pass, but VIS/NIR energy must be blocked.
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(44) A VIS/NIR filter 15 then permits only the desirable SWIR energy to be emitted from the device. A third form employs the phosphor 13 proximal to the camera flash and utilizes a dispersion of VIS/NIR filter material that is distributed throughout at least a portion of the body of the material comprising the structure behind the large area emitter surface. All forms of the device may employ diffusion filters, Fresnel lenses, holographic elements, total internal reflection, or similar known means to promote even distribution of optical energy over the large emission surface. To switch between emission of SWIR energy and visible light, the device may be slid out of the way of the camera flash so that visible light does not energize the phosphor. Rails or tracks may be employed to facilitate the sliding action. Alternately, the device may be completely removed from the smart device when it is not desired to produce SWIR energy.
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(46) It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention, and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
(47) One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures, and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations of the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.