Patent Grant
9557488
The disclosure is directed to optical connectors, and in particular relates to optical connectors with lenses having opposing angled planar surfaces.
Optical fiber is increasingly being used for a variety of applications, including but not limited to broadband voice, video, and data transmission. As consumer devices increasingly use more bandwidth, it is anticipated that connectors for these devices will move away from electrical connections and toward using optical connections or a combination of electrical and optical connections to meet the bandwidth needs.
Generally speaking, conventional optical connectors used for telecommunication networks and the like are not suitable for consumer electronic devices. For instance, conventional optical connectors are relatively large when compared with consumer devices and their interfaces. Additionally, conventional optical connectors need to be deployed with great care and into relatively clean environments, and generally need to be cleaned by the craft prior to connection. Such optical connectors are high-precision connectors designed for reducing insertion loss between mating connectors in the optical network. Further, though optical connectors used in telecommunications are reconfigurable (i.e., suitable for mating/unmating), they are not intended for the relatively large number of mating cycles normally associated with consumer electronic devices.
Besides operating with a relatively large number of mating/unmating cycles, consumer electronic devices are often used in environments where contaminants are ubiquitous. Consequently, an optical connector used for commercial electronic devices must be designed so that any contaminants (e.g., dust, dirt, debris, fluid, etc.) that find their way into the optical connector do not substantially reduce optical connector performance.
Further, the optical connector should be designed so that reflected light does not return to the light source, and so that multiple reflections do not cause interference effects that could impair the performance of the system. The impairing effects of optical reflections can be reduced by applying an anti-reflective coating to the surfaces in the optical path. However, such anti-reflective coatings increase the complexity and cost of the optical connector.
Another known method of reducing optical reflections is to provide an index-matching fluid between optical surfaces. However, the use of index-matching fluids is not practical in applications where a connector needs to be routinely disconnected and connected where the optical surfaces are interfaced. Therefore, it is desirable to have an optical connector that inherently suppresses adverse effects of optical reflections without using anti-reflective coatings or index-matching fluids.
Moreover, certain consumer electronic devices have size and space constraints for making connections and may not be amenable to a straight optical connection, so that an optical connector with a bend is also desirable.
An aspect of the disclosure is an optical connector for optically connecting at least one light source to at least one light receiver. The optical connector includes first and second connector members respectively having first and second positive-power lens elements with respective first and second planar lens surfaces. The lens elements are arranged in their respective connector members such that when the two connector members are operably mated, the first and second lenses form an optical system where the first and second planar lens surfaces are spaced apart in opposition with a narrow gap in between, and are non-perpendicular to the optical system axis. The lenses may be conventional lenses with a convex surface or may be gradient-index lenses each having two planar surfaces. The optical connector is tolerant to contamination that can find its way into the narrow gap.
Another aspect of the disclosure is an optical connector for optically connecting a light source to a light receiver. The optical connector includes a first connector member having a first front section with a first front end, and includes a first lens arranged at the first front section, the first lens having a first axis, a first positive optical power and a first planar surface, with the first planar surface closest to the first front end. The optical connector also includes a second connector member having a second front section with a second front end, and includes a second lens arranged at the second front section, the second lens having a second axis, a second positive optical power and a second planar surface, with the second planar surface closest to the second front end. The optical connector is formed by matingly engaging the first and second front ends to form an optical system with an optical axis formed from the first and second axes, with the first and second planar surfaces being spaced apart in opposition and angled to be non-perpendicular to the optical system axis.
Another aspect of the disclosure is a method of forming an optical connection between at least one light source and at least one light receiver. The method includes connecting a first connector member to a second connector member, with the first connector member having at least one first lens with a first positive power and a first planar surface and the second connector member having at least one second lens with a second optical power and a second planar surface. Connecting the first and second connector members forms at least one optical system from the at least one first and at least one second lenses, with the first and second planar surfaces being spaced apart in opposition and angled to be non-perpendicular to a corresponding optical system axis. The method also includes passing light from the at least one light source to the at least one light receiver via the at least one optical system.
Another aspect of the disclosure is an optical connector for communicating light of an operating wavelength from a light source to a light receiver. The optical connector includes a first connector member having a first rear section and a first front section with a first front end, with a first lens disposed in the first front section, the first lens having a first positive optical power and a first planar surface adjacent the first front end, the first lens having a first focal plane and a first lens axis. The optical connector also includes a second connector member having a second rear section and a second front section with a second front end, with a second lens disposed in the second front section, the second lens having a second positive optical power and a second planar surface adjacent the second front end, the second lens having a second focal plane and a second lens axis. The first and second front sections are configured to matingly engage to form an optical system from the first and second lenses, wherein the optical system has an optical system axis defined by coaxial first and second lens axes, with the first and second planar surfaces being in opposition and spaced apart, and angled to be non-perpendicular to the optical axis.
Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the same as described herein, including the detailed description that follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description present embodiments that are intended to provide an overview or framework for understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments and together with the description serve to explain the principles and operation.
Connector assembly 100 includes plug and receptacle fiber optic cables 110A and 110B that are respectively connected to plug 12A and receptacle 12B of optical connector 10. Plug and receptacle fiber optic cables 110A and 110B respectively carry at least one plug optical fiber 32A and at least one receptacle optical fiber 32B. Connector assembly 100 includes respective strain-relief members (“boots”) 112A and 112B that cover respective portions of the connector assembly where fiber optic cables 110A and 110B respectively interface with plug and receptacle 12A and 12B.
With reference to
Plug 12A and receptacle 12B have their respective front sections 17A and 17B configured to matingly engage at their respective front ends 18A and 18B to establish optical communication between the plug and receptacle over one or more optical pathways, as described below.
In an example, plug and receptacle bodies 16A and 16B are configured to support, at their respective rear sections 20A and 20B, at least one plug ferrule 24A and at least one receptacle ferrule 24B. Plug and receptacle ferrules 24A and 24B have respective front ends 26A and 26B and respective central bores 28A and 28B. Ferrule central bores 28A and 28B are respectively sized to accommodate respective plug and receptacle optical fibers 32A and 32B, which having respective end faces 34A and 34B that respectively reside at or near ferrule front ends 26A and 26B. Plug and receptacle optical fibers 32A and 32B have respective longitudinal optical fiber axes AFA and AFB (see
Likewise, plug and receptacle bodies 16A and 16B are respectively configured to support, at their respective front sections 17A and 17B, at least one plug lens 40A and at least one receptacle lens 40B. Plug and receptacle lenses 40A and 40B have respective focal planes PA and PB located at their respective rear sections 20A and 20B, e.g., at or near ferrule front ends 26A and 26B. Plug and receptacle lenses 40A and 40B also have respective lens axes AA and AB (see
As discussed below, focal planes PA and PB need not be parallel to each other when combined to form optical system 41. Also in an example, focal planes PA and PB generally represent best-focus locations for optical system 41 where light is generally concentrated, and do not necessarily represent locations where light is brought to a point-like focus. Focal planes PA and PB can thus be thought of as image planes of optical system 41 where a light source arranged at focal (image) plane PA is imaged onto a light receiver at focal (image) plane PB.
In an example, at least one of plug and receptacle lenses 40A and 40B consists of a single optical element, while in another example, at least one of the plug and receptacle lenses is formed from multiple optical elements.
In an example, plug and receptacle optical fibers 32A and 32B are respectively arranged in plug and receptacle ferrules 24A and 24B such that optical fiber end faces 34A and 34B extend from respective ferrule front ends 26A and 26B and into respective plug and receptacle chambers 60A and 60B. Thus, respective optical fiber end faces 34A and 34B of the plug and receptacle optical fibers 32A and 32B are spaced apart from respective plug and receptacle lenses 40A and 40B and are generally disposed at respective focal planes PA and PB. Thus, plug and receptacle optical fibers 32A and 32B, which generally represent a light source and a light receiver, are in optical communication with each other through respective plug and receptacle chambers 60A and 60B via the operation of optical system 41.
In an example, plug and receptacle chambers 60A and 60B are filled with air, while in other examples, the chambers are filled with another type of gas, or a solid or a fluid or gel-like dielectric material transparent to the operating wavelength of optical connector 10. Example operating wavelengths for optical connector 10 include one or more of the optical telecommunication wavelengths of 850 nm, 1310 nm and 1550 nm. Other example operating wavelengths include wavelengths associated with vertical-cavity surface-emitting lasers (VCSELS), such as 980 nm and 1060 nm, and 1300 nm and 1600 nm for silicon-based light sources. In an example, the operating wavelength of optical connector 10 is in the range from about 850 nm to about 1600 nm. Optical connector 10 may be operational at multiple operating wavelengths.
In an example, plug lens 40A includes a convex front surface 42A facing toward plug rear section 20A and a planar rear surface 44A at plug front end 18A. Receptacle lens 40B includes a planar front surface 42A at receptacle front end 18B and a convex rear surface 44B facing receptacle rear section 20B. Planar rear surface 44A of plug lens 40A and planar front surface 42A of receptacle lens 40B are opposing and spaced apart to define a gap 48 when plug 12A and receptacle 12B are matingly engaged at their respective front ends 18A and 18B to form optical connector 10. In an example, gap 48 has an axial width WA (see
In an example, opposing planar lens surfaces 44A and 42B are angled with respect to optical system axis A1 (i.e., are not perpendicular thereto) and are parallel to one another.
Example materials for lenses 40A and 40B include Polyetheremide ((PEI), sold by the General Electric Company under the trademarked name ULTEM® 1010), PolyMethylMethacrylate, glass (including Gorilla® glass, a trademark of Corning, Inc., Corning, N.Y.), plastic, Silica/Germania glass, MethylMethacrylate with Benzyl Methacrylate, and combinations thereof as used by those skilled in the art of lens design. In an example discussed in greater detail below, at least one lens 40A and 40B is a gradient-index (GRIN) optical element, for which an exemplary material is the aforementioned Silica/Germania (e.g., Germanium-doped Silica) glass. Examples of optical connector 10 having at least one GRIN lens are discussed in greater detail below.
Example lens design parameters are set forth in Table 1 and Table 2, below. The examples presented in Tables 1 and 2 employ uniform-index refractive lenses. However, the disclosure is also applicable to other lens types, such as the aforementioned GRIN lenses. In Tables 1 and 2 below, the following abbreviations are used: Operating wavelength is λ, fiber core diameter is DC (DCA, DCB) fiber numerical apertures are NAA and NAB, distance from fiber 32A to vertex of lens 40A is DVA, diameter of lenses 40A and 40B are DA and DB, axial gap width is WA, axial thickness of lenses 40A and 40B are THA and THB, distance from vertex of lens 40B to fiber 32B is DVB, lateral offset of optical fiber axis AFB of optical fiber 32B relative to optical axis A1 is LATB, relative angle of optical fiber axis AFB relative to optical system axis A1 is φ, and refractive indices of lenses 40A and 40B are nA and nB,
If optical system 41 is used to couple light 120 between identical optical fibers, then it is desirable that optical system 41 have unit magnification. However, optical system 41 need not have unit magnification. Magnifications other than unity can be achieved for example by using different radii of curvature for convex lens surfaces 42A and 44B.
An example where optical system 41 can have other than unit magnification is when the light source is an active light-emitting device such as a semiconductor laser and the light receiver is an optical fiber. Semiconductor lasers generally have a smaller cross section than an optical fiber core, and also generally have a greater divergence angle than the optical fiber acceptance angle. In such a case, optical system 41 can have a magnification larger than unity, with an example magnification being in the range from 1.5× to 3×.
Another example where optical system 41 can have other than unit magnification is where the light source is an optical fiber and the light receiver is a photodetector. Photodetectors generally have smaller cross section than an optical fiber core, and a greater acceptance angle than the divergence angle of the light beam emitted by the optical fiber. In such a case, optical system 41 can have magnification smaller than unity. With an example magnification being in the range from just under 1× to 0.33× (i.e., 1:3).
Another example where optical system 41 can have other than unit magnification is when coupling between dissimilar optical fibers or waveguides. In this case, optical system 41 can have a magnification larger than or smaller than unity, depending on the relative characteristics of the emitting and receiving optical fibers. It is noted that avoid substantial optical losses, the receiving optical fiber should have étendue equal to or greater than the étendue of the emitting optical fiber.
Also in an example, at least one of convex lens surfaces 42A and 44B is aspheric.
With reference to
Divergent light 120A is then incident upon lens surface 42A and is substantially collimated thereby to form substantially collimated light 120A that travels substantially parallel to optical system axis A1 through plug lens 40A. Collimated light 120A then travels through angled and planar lens surface 44A and across gap 48 to angled and planar lens surface 42B of plug lens 40B, thereby forming substantially collimated light 120B.
There is some refraction of collimated light 120A as it passes through gap 48 due to angled and planar lens surfaces 44A and 42B. However, in the case where opposing angled and planar lens surfaces 44A and 42B are parallel and plug and receptacle lenses 40A and 40B are made of the same material, the light rays making up collimated light 120A and collimated light 120B are substantially parallel to one another and are only slightly displaced relative to each other. Note also that the angled and planar lens surfaces 44A and 42B have no optical power, which is advantageous with respect to contaminants that may be present in gap 48, as described in greater detail below.
Substantially collimated light 120B then travels through receptacle lens 40B to its convex lens surface 44B, where collimated light 120B is converted to converging light 120B, which converges onto receptacle optical fiber 32B at end face 34B located substantially at focal plane PB. In this sense, receptacle optical fiber end face 34B serves as an optical (light) receiver. In an example embodiment such as illustrated in
In an example such as shown in
In an example, angles θA and θB are selected to optimize the performance of optical connector 10, which in an example means at least one of maximizing the light coupling efficiency between the plug and receptacle optical fibers 32A and 32B, minimizing the amount of reflected light that can enter the plug and receptacle optical fibers, and minimizing the reduction in light coupling due to the presence of contaminants in gap 48. Reflected light that makes it back into plug optical fiber 32A can interfere with or otherwise impair normal operation of the original light source (not shown), and reflected light that enters receptacle optical fiber 32B can cause unwanted interference effects downstream, e.g., at a photodetector (not shown).
For optical connector 10 to be so optimized, angles θA and θB need to be sufficiently large to reduce or eliminate the adverse effects of light reflections from one or both of angled and planar lens surfaces 44A and 42B, yet also need to be sufficiently small so that the presence of contamination in gap 48 does not increase WA dramatically and cause light to arrive at receptacle fiber end 34B at an excessively large angle relative to receptacle fiber axis AFB so that it is unable to couple into receptacle fiber 32B.
The ranges for angles θA and θB depend on the specific optical system 10, such as the size and emission angle of the light source, the size and acceptance angle of the light receiver, and the focal lengths of plug lens 40A and receptacle lens 40B. For the example optical systems presented in Tables 1 and 2, angles θA and θB can be in the range from 2 degrees to 7 degrees, and have an absolute difference θA−θB in the range from 2 degrees to 4 degrees. It is also noted that angle θA can be larger or smaller than angle θB.
By way of example, consider fluid 49 in the form of water, which has a refractive index n=1.327 at an operating wavelength of 850 nm. Gap 48 can be sufficiently small so that fluid 49 that is ambient to optical connector 10 can be pulled into the gap via capillary action, thus filling gap 48. The presence of fluid 49 can change both the position and the angle of the light rays making up light 120 as the light travels through gap 48 and to optical fiber 32B.
As discussed above, optical connector 10 is configured such that the axial width WA of gap 48 is generally small. A small gap 48 ensures that the thickness of any liquid contaminants 49 that become trapped in the gap is also small, so that the optical attenuation of light 120 passing through the liquid contaminants is small. Thus, even if the liquid contaminant appears substantially opaque in general use, in thin layers the optical attenuation of such contaminants should be minimal. Also, many foodstuffs consumed in close proximity to computing devices are often water-based, so estimates of optical connector performance using water as a gap material are believed to representative of real-life experiences.
Example optical transmission values through 0.001 inch of example materials at wavelengths averaged over 800 nm to 859 nm are listed in Table 3 below. The listed materials constitute potential contaminants for the optical connector:
In the example of
Thus, in an example, angled and planar lens surfaces 44A and 42B have the following general properties when combined in forming optical system 41: they have no optical power that could be undesirably altered by the presence of contaminants in gap 48; they oppose one another and are spaced apart, and are angled with respective angles θA and θB measured relative to the optical system axis A1, with the angles being selected so that back reflection from either of the planar lens surfaces does not result in a substantial amount of reflected light 120R1 to be coupled back into optical fiber 32A or more generally, back toward the source of light 120A; Angles θA and θB are selected so that doubly-reflected light 120R2 is not coupled into optical fiber 32B; Angles θA and θB are selected so that the deviation and displacement of light 120 caused by presence of fluid 49 in gap 48 between the surfaces is acceptably small, i.e., at most results in an insubstantial change in the amount of light 120B coupled into optical fiber 32B.
Unitary Optical Connector
Unitary optical connector 10 is well suited for providing optical coupling between at least one optical fiber 32B and a corresponding at least one active device 33A, such as a laser or a photodiode. An active device 33A is shown mounted to a motherboard 35A and lies in a plane PAD that is substantially perpendicular to the intersecting optical system axis A1. In an example, active device 33A is mounted on motherboard 35A in such a way that light 120A undergoes a substantially right-angle bend within plug 12A, as described below. Note that unitary optical connector 10 is suitable for connecting multiple optical fibers 32B to multiple other optical fibers 32A or to multiple active devices 33A, thereby creating multiple optical pathways between plug 12A and receptacle 12B.
With continuing reference to
Plug body 16A includes an angled surface SM oriented substantially at a 45 degree angle relative to optical system axis A1 so that the optical system axis is folded by substantially 90 degrees. Angled surface SM defines an internal mirror for plug body 16A that operates by total internal reflection and thus forms a substantially 90 degree bend in the general optical path of light 120A. In an example, convex lens surface 42A and planar lens surface 44A are part of plug body 16A and are formed integral therewith, e.g., via molding or machining Chamber 60A is formed as an open recess at a plug body end 15.
In an example, receptacle body 16B includes a bore 28B with an axis A28, where the bore is sized to accommodate optical fiber 32B. While
As in the previously described example optical connector 10, in an example unitary connector 10, lens surfaces 44A and 42B are angled and planar, and non-parallel i.e., are neither perpendicular to optical system axis A1 nor parallel to each other.
In the operation of unitary optical connector 10, divergent light 120A from a light-emitting active device 33A is emitted through chamber 60A towards convex lens 42, which forms substantially collimated light that travels through a portion of plug body 16A that is substantially centered around optical system axis A1. Collimated light internally reflects by substantially 90 degrees from angled surface (internal mirror) SM and travels towards planar lens surface 44A. Note that the portion of plug body 16A through which light 120A passes effectively defines lens 40A. Also, in this configuration, the plane PAD in which active device 33A resides is co-planar with focal plan PA and is substantially parallel to the folded portion of optical system axis A1 formed by angled surface SM and which passes through receptacle 12B.
Light 120A then passes through planar lens surface 44A and gap 48 and enters receptacle body 16B of receptacle 12B at planar lens surface 42B as light 120B. Light 120B then travels through receptacle body 16B as substantially collimated light until it reaches convex lens surface 44B. Convex lens surface 44B focuses the substantially collimated light 120B to form converging light 120B that travels through chamber 60B and converges onto optical fiber 32B at end face 34B, which is located at focal plane PB. Light 120B then travels in optical fiber 32B as guided light, and eventually exits receptacle 12B and travels on to its next destination, which may be another active device (not shown) such as a photodetector, or a passive device (not shown) such as another optical fiber.
Optical system 42 of connector 10 of
The optical connector 10 disclosed herein is designed to provide optical coupling between a source of optical radiation (i.e., a light source) and a receiver of optical radiation (i.e., a light receiver). The source of optical radiation can be an optical waveguide (such as an optical fiber), or an active device that emits light, such as a laser. The receiver of optical radiation can be an optical waveguide (such as an optical fiber) or an active device that detects light, such as a photodiode. Optical connector 10 is generally configured to mitigate adverse performance effects caused by the presence of contaminants in gap 48, and in an example is optimized for maximum coupling efficiency while minimizing adverse effects from unwanted reflections.
GRIN Lens Embodiments
Thus, lenses 40A and 40B can be generally characterized as lenses having positive optical power, with the optical power originating from either a conventional plano-convex lens with a convex lens surface (42A and 44B, respectively) and angled planar surface 44A and 42B, or from the gradient index of refraction with the volume of each lens 40A and 40B, with the lens surfaces 42A, 44A, 42B and 44B all being substantially planar.
The use of GRIN lenses 40A and 40B in unitary optical connector 10 obviates the need for chambers 60A and 60B, which are employed ostensibly in the non-GRIN embodiments described above to provide a volume having an index of refraction different from the lens so that light can converge or diverge therein after it enters or exits the lens. For a GRIN lens, such convergence and divergence occurs within the volume of the lens so that an adjacent volume with a different refractive index is not necessary. In an example, chamber 60 is used to provide a stand-off between active device 33A and plug body 16A.
In the example embodiment of
An advantage of an optical connector 10 that uses an optical system with the above-described configuration lenses 40A and 40B (whether GRIN lenses, conventional lenses or a combination thereof) is that the plug and receptacle halves 12A and 12B of the optical connector are tolerant to a relative lateral displacement, i.e., the two halves can be laterally displaced without the optical connector experiencing a substantial optical loss. This tolerance is attractive for low-cost manufacturing of optical connector components.
Good alignment of plug 12A and receptacle 12B places planar surfaces 44A and 42B in their proper relative orientation. In an example, alignment of plug 12A and receptacle 12B is accomplished using one or more alignment features, such as alignment features 13A and 13B shown on optical connector 10 of
Although the disclosure has been illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples can perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the disclosure and are intended to be covered by the appended claims. It will also be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the same. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.
This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/431,517 filed on Jan. 11, 2011, the content of which is relied upon and incorporated herein by reference in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4420219 | Muchel | Dec 1983 | A |
| 4526467 | Fantone | Jul 1985 | A |
| 4616900 | Cairns | Oct 1986 | A |
| 4636030 | Carter et al. | Jan 1987 | A |
| 4718744 | Manning | Jan 1988 | A |
| 4787700 | Yin | Nov 1988 | A |
| 4802726 | Palmquist et al. | Feb 1989 | A |
| 4893889 | Iwakiri et al. | Jan 1990 | A |
| 5026131 | Jannson et al. | Jun 1991 | A |
| 5172271 | Sinclair | Dec 1992 | A |
| 5214730 | Nagasawa et al. | May 1993 | A |
| 5805749 | Sato | Sep 1998 | A |
| 5832153 | Duck | Nov 1998 | A |
| 6012852 | Kadar-Kallen | Jan 2000 | A |
| 6253007 | Laughlin | Jun 2001 | B1 |
| 6393179 | Cheng et al. | May 2002 | B1 |
| 6782162 | Fukuzawa et al. | Aug 2004 | B2 |
| 7771129 | Ishida et al. | Aug 2010 | B2 |
| 8182159 | Tanaka | May 2012 | B2 |
| 20020064191 | Capewell et al. | May 2002 | A1 |
| 20030063085 | Huang et al. | Apr 2003 | A1 |
| 20030063853 | Huang et al. | Apr 2003 | A1 |
| 20090269009 | Tanaka | Oct 2009 | A1 |
| 20100265983 | Adachi et al. | Oct 2010 | A1 |
| 20110091156 | Laughlin | Apr 2011 | A1 |
| Number | Date | Country |
|---|---|---|
| 1407740 | Apr 2003 | CN |
| 101535862 | Sep 2009 | CN |
| 53914 | Jun 1982 | EP |
| 0357132 | Mar 1990 | EP |
| 1537477 | Dec 1978 | GB |
| 59034507 | Feb 1984 | JP |
| 0003276 | Jan 2000 | WO |
| 03076993 | Sep 2003 | WO |
| 2006008965 | Jan 2006 | WO |
| Entry |
|---|
| Chinese Office Action and Search Report for Application No. 201280005043.8, dated Nov. 24, 2015, 5 pages. |
| Patent Cooperation Treaty, International Search Report for PCT/US2012/020715, mail date Jul. 25, 2013, 9 pages. |
| International Search Report and Written Opinion issued in corresponding PCT Application No. PCT/US2012/020715, mailed Apr. 5, 2012. |
| TW Search Report for Application No. 101101139, dated May 13, 2015, 1 page. |
| Number | Date | Country | |
|---|---|---|---|
| 20120177327 A1 | Jul 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61431517 | Jan 2011 | US |
