A micromachined plate 11, called a torsion plate, selectively pivots upon a substrate responsively to electrical force so as to move an attached micromirror 12 in a same plane; thereby to accurately selectively intercept, and to reflect, a light beam 2 that is moving parallel to the substrate; forming thus an optomechanical switch 1. The electrical force may be electromagnetic 3 in nature or, preferably, electrostatic. In various embodiments the pivoting torsion plate 11 with the micromirror 12 affixed may be (i) biased off the substrate by a three-dimensional structure 14 and/or by a xe2x80x9creshapedxe2x80x9d torsion beam 11c, (ii) bent as plate 11d, and operated push OR pull, push AND pull, or push AND push, in a rocking operation, (iii) elevated above the substrate upon a self-assembling xe2x80x9cmicro-elevator structurexe2x80x9d 16, and/or (iv) moved greatly in angular position by action of a xe2x80x9cmicro-flapxe2x80x9d 11f. A new design spring-loaded landing electrode 18, and a torsion microhinge 131-134, further enhance performance. The micromachined, or Micro Electro Mechanical Systems (MEMS), optomechanical switch 1 so formed is both fast and accurate to switch light over large angles up to 180xc2x0 while being highly resistant to sticking, or xe2x80x9cstictionxe2x80x9d.

1. Field of the Invention
The present invention generally concerns optical switches; particularly optomechanical switches; and still more particularly micromachined, or Micro Electro Mechanical Systems (MEMS), optomechanical switches.
The present invention particularly concerns micromachined, or Micro Electro Mechanical Systems (MEMS), optomechanical switches-having a MEMS torsion platexe2x80x94which serves to mount a micromirror xe2x80x94that is (i) electrostatically or electromagnetically moved in angular position, and/or (ii) hinged for angularly pivoting movement by surface micromachined hinges, and/or (iii) mechanically biased in angular pivoting movement by torsion springs that also serve to conduct electricity.
2. Description of the Prior Art
2.1 General Prior Art Optical Switching, and Micromachined Optical Switches
Optical switching plays a very important role in telecommunication networks, optical instrumentation, and optical signal processing systems. In telecommunication networks, fiber optic switches are used for network restoration, reconfiguration, and dynamic bandwidth allocation.
There are many different types of optical switches. In terms of the switching mechanism, the switches can be divided into two general categories. A first type, called xe2x80x9coptomechanical switchesxe2x80x9d, involves physical motion of some optical elements. The second type, which will be referred to here as xe2x80x9celectro-optic switchesxe2x80x9d, employs a change of refractive index to perform optical switching. This refractive index change can be induced by electro-optic, thermal-optic, acousto-optic, or free-carrier effects. The electro-optic-type switch generally needs to be implemented in coupled optical waveguides.
Optomechanical switches offer many advantages over electro-optic switches. They have lower insertion loss, lower crosstalk, and higher isolation between ON and OFF state. They are bidirectional and independent of optical wavelength, polarization, and data modulation format. The crosstalk of electro-optic waveguide switches is limited to a range above xe2x88x9230 dB, and is often in the range of xe2x88x9210 to xe2x88x9215 dB, while optomechanical switches can routinely achieve crosstalk  less than xe2x88x9250 dB.
An optomechanical switch can be implemented either in free-space or in waveguides (or in fibers). The free-space approach is more scalable, and offers lower coupling loss to optical fibers. Currently, macro-scale optomechanical switches employing external actuators are available commercially. For example, conventional optomechanical switches are available from JDS, DiCon, AMP, HP, etc. Most of these switches are, however, bulky and require extensive manual assembly. Their speed is also slow, the switching time ranging from 10 milliseconds to several hundred milliseconds. Worse, the switching time often depends on the switching path, i.e., how far is the next output port from the current output port. This is very undesirable for system design. Response times below 1 millisecond are desirable for network applications.
Meanwhile, micromachining technology, also known as Micro Electro Mechanical Systems (MEMS), offers many advantages for building optomechanical switches. MEMS technology is a batch processing technique for fabricating movable microstructures and microactuators. See, for example, K. E. Petersen, xe2x80x9cSilicon as a Mechanical Materialxe2x80x9d, Proc. IEEE 70 (1982) 420-457; and M. F. Dautartas, A. M. Benzoni, Y. C. Chen, G. E. Blonder, B. H. Johnson, C. R. Paola, E. Rice, and Y. H. Wong, xe2x80x9cA Silicon-Based Moving Mirror Optical Switchxe2x80x9d J. Lightwave Technol. 8 (1992) 1078-1085.
Micromachining technology, or MEMS, can significantly reduce the size, weight, and cost of optomechanical switches. The switching time can also be reduced because of the higher resonant frequency of the smaller optomechanical switches. Furthermore, the MEMS optomechanical switch is more rugged than macro-scale switches of equivalent design because the inertial forces are much smaller in the micro-scale switches. MEMS technology has previously been employed to realize various types of optomechanical switches.
2.1 Specific Prior Art Micromachined Optical Switchesxe2x80x94Free-Space Optomechanical Switches
There has been some demonstration of MEMS fiber optic switches. Both bulk-micromachining and surface-micromachining techniques have been employed. However, none of the reported switches fully satisfy all the requirements for large scale network applications. The bulk micromachined 2xc3x972 fiber optic switch was reported by ATandT Bell Labs in 1992. See M. F. Dautartas, A. M. Benzoni, Y. C. Chen, G. E. Blonder, B. H. Johnson, C. R. Paola, E. Rice, and Y. H. Wang, xe2x80x9cA Silicon-Based Moving Mirror Optical Switch,xe2x80x9d in J. Lightwave Technol, 8 (1992) 1078-1085. The Bell Labs switch employs two separate silicon wafers (vertical micromirrors in the top  less than 110 greater than  silicon wafer, and V-grooves in bottom  less than 100 greater than  silicon substrate). The two wafers are joined together manually and external actuators are employed. An insertion loss of 0.7 dB and a switching time less than 10 ms have been obtained. This switch, however, still requires substantial manual assembly and the cost is very high. It does not appear to be scalable to large arrays.
Toshiyoshi and Fujita of the University of Tokyo reported a 2xc3x972 matrix switch using bulk micromachined torsion mirrors. See Toshiyoshi, H.; Fujita, H. xe2x80x9cElectrostatic micro torsion mirrors for an optical switch matrix,xe2x80x9d J. Microelectromechanical Systems, vol.5, p.231-7, 1996. Torsion mirrors are suspended by thin polysilicon beams over through holes etched on silicon substrate. The mirror substrate is then bonded to another silicon substrate, on which bias electrodes and mechanical stops are patterned and etched. When the mirror is attracted downward by the electrostatic force, light is reflected to the orthogonal output fibers. Large switching contrast ( greater than 60 dB), small crosstalk ( less than 60 dB), and a fairly high insertion loss of 7.6 dB were reported. One limitation of this approach is that the mirror angle in the ON state is determined by the mechanical stop on another wafer and cannot be accurately controlled or reproduced. This results in the high insertion loss reported in their paper.
Marxer et al., from University of Neuchatel reported a bulk micromachined 2xc3x972 fiber optic switches using deep reactive ion etching (DRIE) process on silicon-on-insulator (SOI) wafer. See C. Marxer, M.-A. Gretillat, N. F. de Rooij, R. Battig, O. Anthamatten, B. Valk, and P. Vogel, xe2x80x9cVertical Mirrors Fabricated by Reactive Ion Etching for Fiber Optical Switching Applications,xe2x80x9d in Proc. 10th Workshop on Micro Electro Mechanical Systems (MEMS), pp. 49-54, 1997. The 75-xcexcm-thick silicon layer above SiO2 is etched through by DRIE. A 2.3-xcexcm-thick vertical mirror as well as the electrostatic microactuator are created by the same etching step. Switching time below 0.2 ms, coupling loss of 2.5 dB and 4 dB, and switching voltage of 28 V have been achieved. A similar process has recently been reported by the Michigan group. See W. H. Juan and S. W. Pang, xe2x80x9cBatch-Micromachined, High Aspect Ratio Si Mirror Arrays for Optical Switching Applications,xe2x80x9d in Proc. International Conf. Solid-State Sensors and Actuators (TRANSDUCERS 97), Paper 1A4.09P, 1997.
There are two limitations of this approach: (1) the mirror angle and quality are determined by the etching process. Mirror angle  less than 1xc2x0 is difficult to achieve. The rough etched surface also introduces scattering losses. It is also difficult to polish the sidewalls or coat metals on the mirrors. (2) The displacement of the mirror is small because the comb drive actuator has limited displacement. In Marxer""s paper, tapered fibers were placed very closed to the mirror ( less than 20 xcexcm), which reduces the required mirror movement. However, such configuration is not scalable to switches with dimension larger than 2xc3x972 arrays. Michigan""s group did not report the optical characterization data of their switch.
Miller and Tai of Caltech reported an electromagnetically actuated 2xc3x972 fiber optic switches. See R. A. Miller, Y. C. Tai, G. Xu, J. Bartha, and F. Lin, xe2x80x9cAn Electromagnetic MEMS 2xc3x972 Fiber Optic Bypass Switch,xe2x80x9d in Proc. International Conf. on Solid-State Sensors and Actuators (TRANSDUCERS 97), pp.89-92, 1997. The 5-xcexcm thick micromirror is fabricated by anisotropic (TMAH) etching on  less than 011 greater than  silicon substrate. The mirror is then glued a suspended silicon membrane. The silicon membrane is bulk micromachined, and connected to the silicon substrate by cantilevers or torsion beams. It is actuated electromagnetically through the interaction of an integrated copper coil and an external magnet. A switching time of 10 ms, an insertion loss of 3 dB, and switching current of 20-30 mA have been achieved. There are several limitations for this approach: first, the electromagnetic coil has large fringe field and, therefore, high crosstalk among adjacent switching elements. It is difficult to make dense switch arrays. Second, the power consumption for each switch is very high. Heat sinking will be a major issue for large arrays. Third, constant power consumption is required. Forth, the mirror integration process is not a manufacturable process.
In 1995, UCLA reported a surface-micromachined 2xc3x972 fiber optic switch. See S. S. Lee, L. Y. Lin, and M. C. Wu, xe2x80x9cSurface-Micromachined Free-Space fiber Optic Switches,xe2x80x9d Electronics Letters, Vol. 31, No. 17, pp. 1481-1482, August 1995. Surface micromachining offers greater flexibility since it can monolithically integrate various types of three-dimensional micro-optical elements with microactuators. See M. C. Wu, L. Y. Lin, S. S. Lee, and K. S. J. Pister, xe2x80x9cMicromachined Free-Space Integrated Micro-Optics,xe2x80x9d in Sensors and Actuators: A. Physical, Vol. 50, pp. 127-134, 1995.
The UCLA switch is made of a surface-micromachined moveable micromirror. The vertical micromirror was realized by the microhinge technology. See K. S. J. Pister, M. W. Judy, S. R. Burgett, and R. S. Fearing, xe2x80x9cMicrofabricated Hinges, Sensors and Actuators: A. Physical, Vol. 33, pp. 249-255, 1992. This vertical micromirror was integrated on a surface-micromachined translation stage. Because stepper motor (scratch drive actuator) is employed, and large travel distance is needed, the switching time is inherently long (15 msec). See S. S. Lee, E. Motamedi, and M. C. Wu, xe2x80x9cSurface-Micromachined Free Space Fiber Optic Switches with Integrated Microactuators for Optical Fiber Communication Systems,xe2x80x9d in Proc. 1997 International Conferences on Solid-State Sensors and Actuators Transducers 97, Paper 1A4.07P, 1997. This switch also suffers from very poor reliability due to friction and tear/wear (similar to that of the original micromotors). See L. S. Fan, Y. C. Tai, and R. S. Muller, xe2x80x9cIntegrated Movable Micromechanical Structures for Sensors and Actuators,xe2x80x9d in IEEE Trans. Electron. Device, Vol. 35, pp. 724-730, 19E8.
The torsion mirrors such as the Digital Micromirror Devices (DMD) (sometimes xe2x80x9cDeformable Mirror Device) and their variations developed by Texas Instruments can also be employed as an optical switch. See, as an early patent on a DMD, U.S. Pat. No. 4,441,791 to Hornbeck for a DEFORMABLE MIRROR LIGHT MODULATOR and assigned to Texas Instruments Incorporated (Dallas, Tex). The Hornbeck DMD concerns a light modulator where a light-reflective metallized membrane defining a deformable mirror is disposed over a semiconductor substrate in which a matrix array of field effect address transistors are formed.
The modern form of the DMD is basically a torsion mirror with xc2x110xc2x0 tilting angles. Two types of optical switches have been realized by DMD-like devices: the first type employs the DMD as tilting mirrors. Light from input fiber is directed to different output fibers by the DMD. This switch is limited to 1xc3x972 arrays and is very difficult to scale up to larger switches. Packaging is also very difficult since the optical fibers are not in the same plane as the switches. The second type uses the DMD as an ON-OFF switch. For this application, the asymmetric DMD, i.e., the torsion plate with a very long arm, is often employed. To construct a Nxc3x97N switch, each fiber is split into N such ON-OFF switches, and the output to the same fiber is then combined from N switches again. This switch is fundamentally lossy. The fundamental splitting loss is 2 log N, or 18 dB for an 8xc3x978 switch, which is unacceptable for system application without employing optical amplifiers.
Another ON/OFF switch, called in-line fiber gate, was demonstrated by the NTT group. See E. Hashimoto, Y. Uenishi, K. Honma, and S. Nagaoka, xe2x80x9cMicro-Optical Gate for Fiber Optic Communications,xe2x80x9d in Proc. International Conf. on Solid-State Sensors and Actuators (TRANSDUCERS 97), pp.331-334, 1997. Hashimoto, et al. employ the electrostatic torsion beam actuator similar to the Digital Micromirror Device (DMD) of Texas Instruments, Inc, (Dallas, Tex). Instead of using the torsion plate as mirror, another vertical metal mirror is integrated on the torsion plate by electroplating. The height of the micromirror is about 20 xcexcm, and the precise angle of the micromirror is hard to control (an accuracy of 0.5xc2x0 requires an aspect ratio of 115, while most thick photoresist mold""s aspect ratio is less than 20). The displacement of the torsion plate is also very small due to the thin sacrificial layer used. The displacement requirement is relaxed by employing lensed optical fibers, which reduce the optical beam diameter to 2 xcexcm. However, they are not suitable for large switches. The ON/OFF switch is also undesirable for constructing Nxc3x97M switches.
2.3 Specific Prior Art Micromachined Optical Switches Waveguide/Fiber-Based Optomechanical Switches
Ollier and Mottier reported a 1xc3x972 waveguide optical switch. See Ollier, E., Mottier, P., xe2x80x9cIntegrated electrostatic micro-switch for optical fibre networks driven by low voltage,xe2x80x9d Electronics Letters, vol.32, p. 2007-9, 1996. The device consists of a movable waveguide and two fixed waveguides. The movable waveguide is basically a silica cantilever beam realized by undercutting the silicon below the waveguide. The motion is constrained to the inplane direction by two flexure beams. The movable waveguide can be pulled towards either fixed waveguides by electrostatic gap-closing actuators. A fiber-to-fiber insertion loss of 3-4 dB, a switching time of 0.8 ms, and a driving voltage of xc2x128 V has been obtained. Another type of fiber optic switch involves physical movement of the fiber itself instead of waveguide Field, et al. of HP reported a 1xc3x972 fiber optic switch which utilize a electroplated (LIGA) thermal actuator to move the input fiber between two output fibers. See L. A. Field, D. L. Burriesci, P. R. Robrish, and R. C. Ruby, xe2x80x9cMicromachined 1*2 optical-fiber switch,xe2x80x9d Sensors and Actuators A (Physical), Vol. A53, pp. 311-16, 1996. A coupling loss of xe2x88x925.8 dB and isolation of 66.5 dB have been achieved. Another moving-fiber optical switch is reported by Gonzales and Collins. See C. Gonzalez and S. D. Collins, xe2x80x9cMagnetically actuated fiber-optic switch with micromachined positioning stages,xe2x80x9d Optics Letters, Vol. 22, pp. 709-11, 1997. The 1xc3x974 switch consists of one movable fiber and four fixed fibers. The movable fiber is mounted on a bulk-micromachined and manually assembled translation stage, which is actuated by an electromagnetic actuator. A thin film of paramagnetic material (permalloy) is deposited on the input translation stage and an external magnetic field is applied to either side of the sliding stage to align the input fiber to the appropriate output fiber. A switching time of 5 msec, an insertion of 1 dB, and a crosstalk of xe2x88x9260 dB have been achieved for multimode fibers. One of the major constraints of the waveguide-based fiber optic switches is that they are mainly constrained to 1xc3x97N switches, and it is very difficult to scale up to Nxc3x97M switches. The waveguide-type switches also have high fiber-to-fiber insertion loss.
2.4 Background Regarding the Alignment(s) of Free Space Optomechanical Switches
The present invention will be seen to facilitate, and improve, precise optical alignments in free space, and through micromechanical optomechanical switches. A patent discussing the requirements of optical alignment in optical switching is U.S. Pat. No. 5,155,778 to Magel, et. al. for an OPTICAL SWITCH USING SPATIAL LIGHT MODULATORS (assigned to Texas Instruments Incorporated, Dallas, Tex.). This patent concerns a structure for optical interconnection. In one embodiment, the structure consists of optical fibers connected to an array of microlenses, either through integrated waveguides or not, that direct light onto a mirror formed in a substrate, which mirror reflects light to a spatial light modulator. The spatial light modulator in turn reflects the light back to another mirror, which reflects the light through another microlens array, through integrated waveguides or not, and out another optical fiber. The structure is manufactured by forming the mirrors out of the substrate, forming waveguides if desired, forming troughs for the fibers and the microlenses, attaching external pieces such as the fibers, the lenses, and the spatial light modulator package, and packaging the device to maintain alignment.
2.5 Background Regarding the Tilt Angle of Free Space Optomechanical Switches
The performance of DMD-devices is also of interest. The devices of the present invention do not directly have a xe2x80x9ctilt anglexe2x80x9d though which light is reflected, but will be seen to have the ability to selective (i) transmit, or (ii) reflect, an incipient light beam, for an effective xe2x80x9ctilt anglexe2x80x9d of 180xc2x0. It is, however, illustrative to understand how important a large (180xc2x0 is maximum) and regularly repeatable xe2x80x9ctilt anglexe2x80x9d is in free-space optical switching. Such an understanding can be gained from U.S. Pat. No. 5,548,443 to Huang for a LIGHT SEPARATOR FOR TESTING DMD PERFORMANCE assigned to Texas Instruments Incorporated (Dallas, Tex.). The Huang light separator tests the tilt angles of mirror elements of a digital micro-mirror device. The light separator is comprised of two triangular prisms. A bottom prism receives light from all mirror elements. It transmits light from all mirror elements having a tilt angle over a specified angle from a different face than light from mirror elements having a tilt angle less than the specified angle. A top prism receives light from one face of the bottom prism. It further divides the light, so that light from all mirror elements having a tilt angle within a specified range is transmitted from one face and light from other mirror elements is transmitted from another face.
2.6 Background Regarding the Sticking, Adherence, or xe2x80x9cStictionxe2x80x9d of the Moving Elements of Optomechanical Switches
The present invention will shortly be seen to offer improvement regarding the sticking, or adherence, or xe2x80x9cstictionxe2x80x9d of the moving element(s) of an optomechanical switches.
A previous attempt to improve operability in this area is shown in U.S. Pat. No. 5,579,151 to Cho for a SPATIAL LIGHT MODULATOR assigned to Texas Instruments Incorporated (Dallas, Tex.). The Cho Spatial Light Modulator, or SLM, has a reflector that is electrostatically deflectable out of a normal position, where a supporting beam is unstressed, into a deflected position, where a portion of the mirror contacts a portion of a landing electrode which is at the same electrical potential as is the reflector. An inorganic layer or solid lubricant is deposited on the contacting portions. After the modulator is operated for a period of time, the tendency of the reflector to stick or adhere to the landing electrode is diminished or eliminated by the layer so that the reflector is returned to its normal position without any reset signal or with a reset signal having a reasonably low value. Preferred materials for the layer are SiC, AlN or SiO(2).
Yet another previous effort to deal with this problem is shown in U.S. Pat. No. 5,665,997 to Weaver, et. al. for a GRATED LANDING AREA TO ELIMINATE STICKING OF MICRO-MECHANICAL DEVICES assigned to Texas Instruments Incorporated (Dallas, Tex.). The Weaver digital micro-mirror device (DMD) has contacting elements that are reportedly not prone to stick together. In the case of a deflecting mirror device, landing electrodes are covered with a grating, which serves to reduce the contacting area but still permits conduction between the mirror and a landing electrode. Alternatively, the landing electrode can be fabricated as a grated surface.
2.7 Background Regarding Optomechanical Hinges, as May be Used in Optomechanical Switches
The optomechanical switch of the present invention will shortly be seen to preferably incorporate a micromechanical hinge of improved form. A general reference to the state of the art in these micromechanical structures is given in K. S. J. Pister, M. W, Judy, S. R. Burgett, and R. S. Fearing, xe2x80x9cMicrofabricated Hinges, Sensors and Actuators: A. Physical, Vol. 33, pp. 249-255, 1992.
Another reference is U.S. Pat. No. 5,600,383 to Hornbeck for a MULTI-LEVEL DEFORMABLE MIRROR DEVICE WITH TORSION HINGES PLACED IN A LAYER DIFFERENT FROM THE TORSION BEAM LAYER assigned to Texas Instruments Incorporated (Dallas, Tex.). The Hornbeck multi-level DMD (where here the initials xe2x80x9cDMDxe2x80x9d have their alternative meaning of xe2x80x9cdeformable mirror devicexe2x80x9d) concerns a bistable pixel architecture where torsion hinges are placed in a layer different from the torsion beam layer. This results in pixels which can be scaled to smaller dimensions while at the same time maintaining a large fractional active area, an important consideration for bright, high-density displays such as are used in high-definition television applications.
The present invention contemplates micromachined, or Micro Electro Mechanical Systems (MEMS), optomechanical switches of new design having certain advantages over existing MEMS optomechanical switches. These advantages include, inter alia, (i) increasing the speed, certainty and exactitude of (micro-)movement (which movement is, among other things, useful for the optical switching of a light beam), while (ii) reducing stiction, of sticking, of the components of the optomechanical switch.
The invention realizes these advantages through certain unique structures that are usable both in the preferred micromechanical optomechanical switches of the present invention and also in other MEMS switches and devices. These structures include (i) geometries of (micromachined) electrode plates and/or electrical coils which serve to develop electrostatic and/or electromagnetic forces so as to move a (micromechanical) switch element in (angular, pivoting) position, (ii) surface micromachined hinges which permit a (micromachined) plate to be accurately angularly pivoted in a predetermined plane, (iii) (micromechanical) torsion springs that both mechanically bias the (micromachined micro-hinged) plate in its angular pivoting movement and that also serve to conduct electricity to the (micromachined angularly pivoting microhinged) plate, and (iv) a structure micromachined upon a substrate for both mechanically receiving, and for making electrical connection to, a distal end region of micromachined plate that is controllably pivoting about the substrate from its proximal end region so as to selectively land upon the structure, thus xe2x80x9ca micromachined landing electrode structurexe2x80x9d.
1. A Micromachined Optomechanical Switch
1.1 Hinged for Pivoting Operation Under Electrical Force
In one of its aspects the present invention is embodied in a micromachined optomechanical switch having (i) a micromirror that is mounted to (ii) a micromachined plate (sometimes called a xe2x80x9ctorsion platexe2x80x9d) that is itself mechanically hinged about a pivot axis to (iii) a substrate. The switch is activated by a circuit that selectively develops (i) an electrostatic or (ii) an electromagnetic force between the micromachined plate and the substrate, either of which (i) electrostatic or (ii) electromagnetic force causes the micromachined plate and the micromirror mounted thereto to pivot in angular position relative to the substrate.
By this pivoting operation a radiation beam will selectively intercept the micromirror dependent upon whether the micromachined plate is, or is not, moved in angular position by action of the electrostatic, or the electromagnetic, force that is selectively developed by the circuit between the micromachined plate and the substrate. Ergo, an electrically-controlled optomechanical switch is realized.
Note that the (i) micromirror is not the same as the (ii) pivoting micromachined plate. Indeed, the micromirror is preferably mounted (i) perpendicularly to the micromachined plate, and (ii) orthogonally to the pivot axis of the (pivoting) micromachined plate. By this orientation, and by this relationship, the micromirror will constantly move in the same plane during all angularly pivoting movement of the micromachined plate. This xe2x80x9csame-planexe2x80x9d operation is very useful both (i) to selectively direct an incident radiation beam that skims over the top of the substrate (and that is typically at 45xc2x0 to the plane of the micromirror) in useful directions, and (ii) to maintain precision optical alignment.
1.2 Hinged for Pivoting Operation Under Electrostatic Force
In greater detail, one, preferred, embodiment of the micromachined optomechanical switch employ electrostatic force as its reliable, strong, and readily-realized actuation mechanism. It is possible to generate either (i) a repulsive electromagnetic force, or (ii) an attractive electromagnetic force, between the micromachined plate and the substrate by the simple expedient of placing an electrostatic charge on both the micromachined plate and the substrate that is, respectively, (i) of the same polarity, or (ii) of differing polarity.
In actual implementation, the generation of a repulsive electrostatic force requires placement of a same-polarity electrical charge on two conductors one or which is electrically floating, and this is more difficult to realize than is the placement of an opposite-polarity electrical charge on each conductor. Therefor the preferred MEMS devices of the present invention, as do the majority of electrostatic MEMS devices, mainly use an attractive electrostatic force, which attractive electrostatic force can readily be easily realized by applying a voltage between two conductors, in this case the (i) micromachined plate and (ii) the substrate.
In developing either the attractive or the repulsive type of electrostatic force, at least one of the micromachined plate and the substrate is electrically conducting. Normally the micromachined plate is so conducting. The mechanism for selectively developing an electromagnetic force between the micromachined plate and the substrate requires selectively emplacing, and removing, an electrostatic charge. The electrostatic force developed in response to the electrostatic charge (or, more simply, an xe2x80x9celectrical voltagexe2x80x9d) operates so as to attract (alternatively, so as to repel) the micromachined plate from the substrate, causing it to pivot in angular position about a hinged pivot axis towards (alternatively, away from) the substrate.
An electrical insulator is positioned between (i) the substrate and (ii) the micromachined plate that is hinged to, and that pivots upon, the substrate. An electrical voltage selectively developed between, as a first electrode, (i) the substrate, and, as a second electrode, the (ii) micromachined plate, produces an electrostatic force that serves to pivot the micromachined plate and the micromirror mounted thereon relative to the substrate.
1.3 Hinged for Pivoting Operation Under Electromagnetic Force
Another, less preferred, embodiment of the micromachined optomechanical switch uses electromagnetic force as the actuation mechanism. In this case an electromagnet is positioned in one of (i) the substrate and (ii) the micromachined plate (that is hinged to, and that pivots upon, the substrate), while, typically, a permanent magnet is placed in the remaining one of (i) the substrate and (ii) the micromachined plate. (It is possible to use an electromagnet in both (i) the substrate and (ii) the micromachined plate.)
Selectively energizing the electromagnet produces an electromagnetic force that serves, dependent upon the magnetic polarization, either to attract, or to repel, the permanent magnet, thus (in either case) pivoting the micromachined plate and the micromirror mounted thereon relative to the substrate.
In accordance with the principles of a common solenoid that a it is more effective to produce a repulsive electromagnetic force than an attractive electromagnetic force between an electromagnet and a permanent magnet that is appropriately aligned to the field of the electromagnet, in the preferred micromachined optical switches of the present invention the magnetic field of the permanent magnet is positioned and oriented relative to the electromagnet so that energization (at a predetermined direction of current flow) of the electromagnet serves to repel the permanent magnet. Note that, being repulsive in nature, the preferred electromagnetic force is opposite to the preferred electrostatic force, which is attractive in nature.
In fact, the numerous preferred embodiments of micromachined optomechanical switches in accordance with the present invention can be made so as to employ either an attractive or a repulsive force (or both, in certain switch embodiments) of either an electrostatic and/or an electromagnetic nature. Although certain force directions and force types are preferred for ease of implementation, a practitioner of the electrical arts will realize that all the various variations of construction are essentially equivalent.
Indeed, embodiments of the micromachined optomechanical switches in accordance with the present invention which use both attractive and repulsive forces at the same time, or at separate times, are eminently possible. If the attractive force is considered to be a xe2x80x9cpullxe2x80x9d, and the repulsive force to be a xe2x80x9cpushxe2x80x9d, then the term xe2x80x9cpush-pullxe2x80x9d is defined as xe2x80x9cpush OR pullxe2x80x9d, or those very xe2x80x9csingle electrical actionxe2x80x9d switches just discussed. However, the term xe2x80x9cpush and pullxe2x80x9d is reserved for switches that electrically both push AND pull. It is possible to construct a xe2x80x9cpush and pullxe2x80x9d switch having both attractive and repulsive forces (i) exerted in separate areas of the same switch at the same time, or (ii) exerted in the same or in separate areas of the same switch at separate times.
If both the xe2x80x9cpush and pullxe2x80x9d forces are exercised concurrently, then the switch will generally be very xe2x80x9cstrongxe2x80x9d and very xe2x80x9cfastxe2x80x9d to assume at least a desired forced position. Conversely, if the xe2x80x9cpush and pullxe2x80x9d forces are exerted in a time sequence, then the switch will clearly exhibit d positively-controlled action, assuming first one and then the other position each under a applied electrical force. Likewise, it is possible to build a hybrid xe2x80x9cpush and pullxe2x80x9d switch that combines, for example, electrostatic pull and electromagnetic push; again at the same time, or at separate times.
Continuing with the basic electromagnetic embodiment of the micromachined optomechanical switch, the electromagnet is preferably located in the substrate, thus making that the permanent magnet is located in the micromachined plate, for reason of ease of fabrication. However, the opposite positions are possible. The permanent magnet is preferably made from a magnetic material integrated within the micromachined plate, and is more preferably made of permalloy. The electromagnet is normally a simple loop of conductor, such as may be made from the traces upon a printed circuit substrate.
1.4 With the Pivoting Element Biased in Position to Reduce Stiction
Variants of both embodiments of the micromachined optomechanical switch permit (i) minimization of stiction, or the undesirable sticking of the micromechanical pivoting plate to the substrate, and (ii) maximization of the spatial movement of the mirror.
For example, in the magnetic embodiment just discussed, the permanent magnet in the micromachined plate can serve to bias the micromachined plate in position off the substrate. This bias will exist regardless that the electrostatic or the electromagnetic force that serves to repel (or to attract) the micromachined plate, and that causes it to pivot away from the substrate, may be absent. The positional biasing of the micromachined plate from off the substrate diminishes the possibility of stiction of the micromachined plate to the substrate.
This positional biasing is typically realized mechanically. In one embodiment of the micromachined optomechanical switch a three-dimensional surface-micromachined structure serves to physically support the micromachined plate in a position angled about the pivot axis and displaced off the substrate. Again, the biasing the pivoting micromachined plate in position off the substrate serves to diminish the possibility that the micromachined plate will fail in its pivoting motion by undesirably adhering to the substrate.
1.5 Push-pull, and Push and Pull Switches
In another, embodiment, the micromachined plate is bent about an axis, and pivots about the substrate along this axis. As a consequence of this bend, only a portion of the micromachined plate that is upon a one side of the axis will (or can) be against the substrate at any one time, while the portion of the micromachined plate that is upon the other side of the axis will be angled away from the substrate.
The micromirror is mounted to only one bent arm portion of the micromachined plate. The bent micromachined plate serves like a rocker, alternately lifting and lowering the micromirror from the substrate.
Typically one (only) arm portion of the bent micromachined plate is biased in position by a torsion spring. The restoring force of this torsion spring is compounded by an electromagnetic or electrostatic force. This switch is called a xe2x80x9cpush-pullxe2x80x9d switch where it is remembered that this term means to electrically push (i.e., repulse) OR pull (i.e., attract). Clearly then the other push, or pull, force is provided by the spring.
However, it is also possible to construct, as a variant of the pivoting micromachined plate xe2x80x9cpush-pullxe2x80x9d switch, a xe2x80x9cpush and pullxe2x80x9d switch. This xe2x80x9cpush and pullxe2x80x9d micromachined optomechanical switch permits that all movement of the rocker plate within the switch transpires under positive electrical control. This occurs because the electrical circuit for selectively developing a force selectively so develops a force that alternately repels each portion of the micromachined plate. These forces can be sequenced so as to positively force the micromachined plate to pivot in position: first so as to xe2x80x9cpush-the-first-portionxe2x80x9d followed by xe2x80x9cpush-the-second-portionxe2x80x9d. A rocking motion of the switch is thus induced in a xe2x80x9cpush and pushxe2x80x9d operation.
Alternatively, the forces between the substrate and each portion of the bent micromachined plate may be temporally sequenced so as to positively force the micromachined plate to pivot in position first in a xe2x80x9cpush-the-first-portion while pulling-the-second-portionxe2x80x9d operation, followed by a xe2x80x9cpull-the-first-portion while pushing-the-second-portionxe2x80x9d operation, or a xe2x80x9cpush and pullxe2x80x9d operation. Clearly the xe2x80x9crockingxe2x80x9d bent micromachined plate, and the micromirror mounted thereto, are not only controlled in position, but may be made to strongly and quickly assume any desired position.
These variants are quite useful. An optical switching system designer will normally use a micromechanical xe2x80x9crocker switchxe2x80x9d that has the desired response time in each direction of its motion.
1.6 Even More Substantially Three-dimensional Pivoting Switches
Certain other three-dimensional structures are equally, or even more, efficacious for strong, fast, positive switch control.
In one three-dimensional embodiment a micromachined structure serves to elevate the micromachined plate above the substrate, and about a pivot axis that is intermediary in position within the micromachined plate between a first portion and a second portion thereof. (Normally but one micromirror is, as before, mounted to but one portion of the micromachined plate.)
The mechanism for selectively developing a force between the micromachined plate and the substrate so develops the force first between the substrate and one portion of the micromachined plate, and then between the substrate and the other portion. This causes the micromachined plate and the micromirror mounted thereto to pivot in angular position relative to the substrate (as before), only now about the elevated pivot axis.
In accordance with (i) the principle of a lever, and in accordance with the fact that (ii) the micromachined plate may be greatly pivoted in angle in its position elevated above the substrate, the micromirror may be greatly moved in position. In other words, small, or micro, machines can be made to reliably positively produce (relatively) large and useful motions! The (micro)force produced at the long end of the pivoting lever is, of course, minuscule. Luckily, it does not take any great force to reflect light in a mirror, nor to block the transmission of light by a opaque filter!
Normally when (micro)forces are minuscule, stiction can be a problem. Certain other structures within micromachined optomechanical switches in accordance with the present invention serve to minimize, or even eliminate, this problem.
2. A Micromachined Landing Electrode Structure
In accordance with another of its aspects, the present invention is embodied in a micromachined landing electrode structure. This is a structure micromachined upon a substrate for (i) mechanically receiving, and (ii) making electrical connection to, a distal end region of micromachined plate that is pivoting about the substrate at its proximal end region so as toxe2x80x94among such other things as were, for example, discussed abovexe2x80x94selectively land upon this structure (which is upon the substrate). The structure is thus called a xe2x80x9cmicromachined landing electrode structurexe2x80x9d.
This micromachined landing electrode structure is made from an electrically conductive buckled beam that is buckled above a plane of the substrate in a location that falls under the distal end region of the pivoting micromachined plate. The buckled beam serves (i) as a spring to the pivoting movement of the micromachined plate (at least when it draws near to the substrate) (ii) as an electrode for making electrical contact to the micromachined plate when the micromachined plate is pivoted into (pressured) contact therewith, and (iii) as a stop helping to prevent stiction between the pivoting micromachined plate and the substrate.
The electrically conductive buckled beam is itself preferably formed as polysilicon beam that is pushed until it buckles, and that is then locked in its buckled position into a micromachined structure.
The micromachined plate is normally biased in its angular position by a torsion spring and/or by an electrostatic or an electromagnetic force. When the micromachined plate is in full contact with the substrate, then the contact area is large and the stiction force between micromachined plate and the substrate could also be large. If this stiction force proved to be larger than the restoring force of a torsion spring serving to bias the pivoting micromachined plate in position, then the micromachined plate could become permanently undesirably stuck to the substrate. To combat stiction force, the contact area is reduced by employing the buckled beam, which reduces the contact area to basically a point. Additionally, the larger spring constant of the buckled beam can make the total restoring force larger than any residual sticking force, therefore further reducing the possibility of stiction.
The micromachined plate is normally biased in its angular position by a torsion spring. The spring constant of the buckled beam is made to be much larger than that of the torsion spring so that a force on the micromachined plate by the buckled beam (when the micromachined plate is in contact therewith) will be much stronger than an opposite force on the micromachined plate arising from the torsion spring. The anti-stiction restoring force may alternatively be realized by a cantilever bending spring that is cantilevered from the approximate center of the buckled beam so as to contact the micromachined plate when its pivots close to the substrate. Both bucked beam and/or cantilevered spring provide a spring force that serves to angularly kick the torsion plate off the substrate when any (electrostatic or electromagnetic) force holding it proximately to the substrate is released. This effect promotes fast mechanical action of the micromachined plate, and of the micromachined optomechanical switch of which the micromachined plate forms a part.
3. Improved Micromachined Hinges
In still yet another of its aspects, the present invention is embodied in hinges for a micromachined plate that is angularly hinged for pivoting upon and relative to a substrate.
The hinged pivoting micromachined plate mechanism includes (i) a micromachined plate having at least one substantially straight side adjacent to which straight side is relieved at least one hole. Only a narrow strip of the plate remains between this at least one hole and the edge of the straight side.
The mechanism further includes (ii) so many micromachined staples as there are holes are attached to the substrate. Each staple spans over the narrow strip of the micromachined plate and into a hole so that both ends of the staple can be permanently connected to the substrate. The mechanism thus formed holds the micromachined plate to angularly pivot about the substrate on its narrow strip, which serves as a hinge pin, and along its straight side.
Although these structural elements (i) and (ii) taken alone may well be different from previous micromachined structures, it should be recalled that, in accordance with the principles of the present invention, this pivoting, hinged, micromachined plate must also be both (i) supplied with electrical voltage (at least in the electrostatic embodiments of the switch) and (ii) mechanically biased in position (at least for those switch embodiments that are not xe2x80x9cpush and pullxe2x80x9d). The preferred hinged pivoting micromachined plate mechanism does so permit (i) the micromachined plate to angularly pivot on its straight side about the substrate while (ii) an electrical bias is separately provided to the micromachined plate.
This dual function is accomplished by the final structural element of (iii) one or more torsion springs each of which are attached between the substrate and a region along the straight side pivoting end of the micromachined plate. This (these) torsion spring(s) serves to mechanically bias the micromachined plate in angular position towards the substrate, and into but an acute angular separation therefrom. The angular displacement of the micromachined plate, as it pivots on its hinge pin, is normally limited by these one or more torsion springs.
The combination of (i) the straight-edged holed micromachined plate, (ii) the staples spanning such narrow portion of the micromachined plate as serves as the hinge pin, thus constraining the micromachined plate to pivot upon its straight edge, and (iii) the one or more torsion springs, combine to establish a well-defined axis and direction of angular rotation to the pivoting micromachined plate. In other words, the micromachined plate is exactingly positioned, and rotates exactinglyxe2x80x94properties which are useful for the precision deflection of light.
Moreover, the same (iii) one or more torsion springs also serve to conduct electricity between an appropriate electrical trace upon the substrate and, again, the same straight-side pivoting-end region of (i) the micromachined plate. Selective electrical energization proceeding along this conductive path is, or course, exactly how the hinged micromachined plate (and any micromirror attached thereto) is caused to variably selectively pivot in angular position relative to the substrate.
These and other aspects and attributes of the present invention will become increasingly clear upon reference to the following drawings and accompanying specification.


According to one embodiment, a magnetic resonance imaging apparatus includes a data acquisition unit, an eddy magnetic field measuring unit and an imaging unit. The data acquisition unit is configured to acquire magnetic resonance signals at mutually different timings with applying a gradient magnetic field for generating an eddy magnetic field. The eddy magnetic field measuring unit is configured to acquire eddy magnetic field information including a time constant of the eddy magnetic field based on phase information of the magnetic resonance signals acquired at the timings. The imaging unit is configured to perform imaging under an imaging condition or a data processing condition according to the eddy magnetic field information.

MRI is an imaging method which excites nuclear spin of an object set in a static magnetic field with a RF (radio frequency) signal having the Larmor frequency magnetically and reconstructs an image based on MR (magnetic resonance) signals generated due to the excitation.
In MRI, gradient magnetic fields are applied by gradient coils for acquiring MR signals. However, gradient magnetic fields are generated as pulse waves. Therefore, in case of being an electrical conductor around a gradient coil, an eddy current is generated in the electrical conductor when a gradient magnetic field rises and falls.
A heat shield of a static field magnet is included in examples of electrical conductors. When a super conducting magnet which generates a static magnetic field not less than 0.5 T is used as a static field magnet, a metallic container including liquid helium is provided as a heat shield in the super conducting magnet. Additionally, plural metallic containers such as a metallic container including liquid nitrogen are arranged around the liquid helium layer. Therefore, applying a gradient magnetic field produces an eddy current in each metallic container.
Temperatures, materials and sizes of respective metallic containers set in a static field magnet are different mutually. Therefore, an intensity and an attenuation time constant of eddy current generated in each metallic container has plural components. Generally, a time constant of an eddy current is in a wide range from 0.2 ms to 3 ms.
Meanwhile, an application of a gradient magnetic field also produces a self-eddy current in a gradient magnetic field coil material itself. The self-eddy current sometimes produces considerable strain of a magnetic field.
The eddy current as mentioned above produces an eddy magnetic field which changes due to the eddy current and generates a strain in a waveform of a gradient magnetic field outputted as a controlling value from a controller in a MRI apparatus. Then, the strain of the gradient magnetic field leads to an image artifact.
Accordingly, an Actively Shielded Gradient Coil (ASGC) to suppress generation of an eddy magnetic field is devised. Alternatively, compensation of an eddy magnetic field which corrects a waveform of a gradient magnetic field strained by an eddy magnetic field is devised. In principle, ASGC makes it possible to reduce an intensity of an eddy magnetic field substantially.
However, practically, it is not possible to prevent a minute eddy magnetic field from being generated for reasons such as production error of an ASGC and discrete arrangement of coil wires. Therefore, in the case of using a high-speed imaging method such as an EPI (echo planar imaging) method, it is possible to generate artifact in an image by the presence of a slight eddy magnetic field. Then, it is preferable to perform compensation of an eddy magnetic field even if a gradient magnetic field is applied with an ASGC.
The method to adjust a waveform of a gradient magnetic field set as a pulse sequence so as to cancel an eddy magnetic field is devised as another technology of suppressing an eddy magnetic field. For example, DWI (diffusion weighted imaging) is performed by an EPI sequence while applying an MPG (motion probing gradient) pulse. The MPG pulse is an intensive gradient magnetic field pulse. Therefore, a technology to adjust a gradient magnetic field other than an MPG pulse in an EPI sequence so as to cancel an eddy magnetic field generated due to the MPG pulse is suggested.
It is significant to measure intensities, time constants and a spatial distribution of eddy magnetic fields in advance with satisfactory accuracy in order to perform compensation of the eddy magnetic fields precisely. For example, in the case of performing DWI, it is significant to measure an eddy magnetic field having a time constant from 0.2 ms to 30 ms with satisfactory accuracy. Intensities and time constants of eddy magnetic fields can be obtained in accordance with phase shift information of MR signals acquired by a pulse sequence for measuring the eddy magnetic fields.
On the other hand, recently, an MRI apparatus which can generate static magnetic field intensity not less than 3 T becomes widely used. Under the high magnetic field as mentioned above, an influence to attenuation of a MR signal intensity by transverse relaxation star (T2*) relaxation may be not negligible. That is, both phase shifts by eddy magnetic fields and T2* attenuation occur in MR signals. In this case, it becomes difficult to obtain intensities and time constants of eddy magnetic fields from phase shift amounts of MR signals precisely. Especially, when DWI is performed, it becomes more difficult to measure intensities and time constants of eddy magnetic fields with high accuracy since a time constant of an eddy magnetic field becomes equivalent to that of T2* attenuation.
That is, it is difficult to measure intensities and time constants of eddy magnetic fields, each having a time constant from 0.2 ms to 30 which is equivalent to that of T2* attenuation especially, with satisfactory accuracy under a high magnetic field not less than 3 T with a conventional technology. Not only under a high magnetic field, it is desired to measure intensities and time constants of eddy magnetic fields with satisfactory accuracy.

Magnetic resonance imaging apparatus and magnetic resonance imaging method


Magnetic field gradient sensing apparatus utilizing highly sensitive fluxgate magnetometers permit direct determination of the distance between two well bores and for determining the direction from one bore to the other. The gradient sensing apparatus may be responsive to alternating magnetic fields resulting from current flow in a steel casing within a target well and measured by two fluxgate magnetometers diametrically oppositely located in a sensor tool and oriented to measure the vector components of the alternating field at opposite sides of the tool to thereby obtain a measure of the gradient of the field across the diameter of the tool. Field gradient sensing apparatus may also be used to measure the gradient of a static magnetic field having a radial gradient, wherein the static field is produced by ferromagnetic materials in the target well. Again, a pair of magnetometers is utilized to measure the field gradient across the diameter of the sensor to determine distance and direction to the target. Both static and alternating magnetic fields may be simultaneously measured for improved accuracy and reliability.

The present invention is directed, in general, to an apparatus and a method of determining the distance between a relief well, or borehole, being drilled and an existing cased target well. More particularly, the invention is directed to a method for directly obtaining the distance between a relief borehole and a target well through the measurement of alternating or static magnetic field gradients, or both, at the location of the relief well. The invention further provides a method for determining the direction to the target well from the relief well.
Although electronic methods for guiding the drilling of a relief borehole to intersect an existing, or target, well having a casing have been extremely successful, it has recently become apparent that often some additional way to guide the final portion of the relief borehole after it is within a few feet of the target is needed. This need arises particularly when the total depth of the target well closely coincides with the desired intersection point, which often occurs, or if complications arise with mathematical modeling in a situation where modeling is required for determination of the current flow on the target. During the drilling of a relief well, particularly after it is within a few feet of the target, static Earth field perturbations can be very large due to the ferromagnetic nature of the casing of the target well. The magnetic poles which generate these perturbations are "smeared out" along the length of the target well to such an extent that the present methods of mathematical analysis of the associated field perturbations have been virtually useless, and this problem has led to documented cases of drastic error in directing the relief well.

Alternating and static magnetic field gradient measurements for distance and direction determination


In the fluid filling device A of the present invention, when installed in the fluid filler port B1 of the drum B, the hollow internal space of the tubular body 10 provided with the communication part 10a communicating with the internal space of the drum B is divided into the fluid inlet part 10b for leading waste oil into the drum B from outside and the fluid outlet part 10c for leading the waste oil filled into the drum B to the outside of the drum B. The fluid filling device A is further provided with the fluid inlet 11 for leading the fluid from the fluid filler port outside the container in communication with the fluid inlet part 10b and the fluid outlet 12 for leading the fluid filled into the container to the outside of the container in communication with the fluid outlet part 10c.

Conventionally, in order to empty the waste oil out of an oil tank of a heavy machine or the like into a drum, the waste oil has been conveyed into a container from the outlet of the oil tank of the heavy machine, and the waste oil conveyed into the container has been pumped into a drum via a hose.
In this method, although it depends on the capacity of the oil tank and the capacity of the drum, the amount of the waste oil discharged from the heavy machine can be much larger than the capacity of the drum, which requires more than one drum to accommodate the waste oil.
In filling the waste oil into these drums, the waste oil is conveyed into a first drum, and when this drum is filled to capacity, the other end of the hose is switched to the fluid filler port of a second drum to fill the drum with the waste oil.
The hose switching operation is repeated until the oil tank is emptied.
However, the hose switching operation in emptying the waste oil into the drums is very troublesome, with the fear that the operator may inadvertently spill the waste oil from the drums.
The spilled waste oil may stain not only the drums as the containers but also the floor or the ground and the operator's clothing; cleaning the spilled waste oil is very troublesome.
The present invention, which has been contrived to solve these problems, has the object of providing a fluid filling device which can fill fluid into a container without difficulty or the fear of spilling the fluid, and consequently without the fear of staining the operator's clothing with the spilled fluid.


A bathing system, includes a transfer system having a carrier base and a transfer seat. A sliding of the transfer seat relative to the carrier base may facilitate transfer of the transfer seat toward or away from the tub. A first arm and a second arm of the carrier base extends into and overlaps with a first support surface and a second support surface of the tub respectively. A controller may be in operative communication with a plurality of sensors and determine whether the bathing system is in a state where it is permissible to transfer the transfer seat toward or away from the tub and if so, actuate components of the transfer system to permit the transfer of a patient in the transfer system.

Immersion bathing and/or hydrotherapy for assisted and/or self-bathing in various medical care and long-term care institutions typically involves transporting a patient using a transfer system into a bathing tub. Many existing transfer methods do not adequately provide for patient dignity and safety and may be a source of embarrassment and/or anxiety for the bather. The safety shortcomings of such systems may sometimes result in fall, injury or even death of the patient due to user error, and/or lack of monitoring the transfer process.

Systems and methods for a bathing system


Natural gas is stored in a closed vessel under a pressure of about 1400 to 4500 kPa using a carbon molecular sieve adsorbent. The deliverable volume of natural gas from a vessel packed with carbon molecular sieve particles is increased by raising the density of the polymer precursor of the carbon molecular sieve through adjustment of the conditions for suspension polymerization of vinylidene chloride.

This invention relates to a method of storing natural gas. More particularly, the invention relates to storage of natural gas at near ambient temperatures using a solid adsorbent, in particular, a carbon molecular sieve.
U.S. Pat. No. 4,820,681 discloses an improved carbon molecular sieve which has a high capacity for carbon dioxide and may be characterized as hydrophobic, requires no binders, and may be carbonized in a single step.
Natural gas, being substantially methane, has a low molecular weight and it occupies a large volume per unit weight compared to liquid fuels. Thus, reducing the volume of natural gas is necessary for most practical applications of natural gas as a fuel. Methods for doing this could include (1) storage at high pressure, (2) liquefaction and storage at low temperatures, and (3) adsorption on solids. Of these methods the last is of particular interest since compact storage of natural gas at moderate pressures may be achieved, while avoiding the cryogenic temperatures needed for liquid natural gas of the high pressures needed for storage as a gas within reasonable size vessels.
Conventional activated carbons have been found to have reasonable capacity for natural gas but higher capacity is believed necessary for commercial success. Inorganic zeolites have also been tried, but found to have relatively low capacity for natural gas. Carbon molecular sieves also have been suggested for adsorption of natural gas. Improvements in the storage of natural gas have been disclosed in copending applications U.S. Ser. Nos. 07,906,995, 07/906,993 and 07/964,174.
The present inventors have found a method for increasing the packing density of carbon molecular sieves and thereby increasing the volumetric efficiency of the adsorption of natural gas. The invention relates to improvements in the suspension polymerization which provides a polymer precursor to such carbon molecular sieves. A discussion of suspension polymerization of vinylidene halides may be found, for example, in U.S. Pat. No. 4,163,090 to Dow Chemical Co.

Improving the density of carbon molecular sieves for the storage of natural gas


A portable, extremity-attachable device for dispensing skin treatment comprises a deformable housing having a skin treatment reservoir that is caused to dispense such treatment upon squeeze actuation. A set of valves permit proper operation of the device with different modes of use. Embodiments include a simple deformable, wrist-mounted device and a pumped based device with a rigid housing.

The increase in bacterial immunity to modern antibiotics is problematic and one of the chief vectors of infection is the human hand. Hence, when not in the proximity of a washroom to disinfect one's hands, it would be useful to have a means to accomplish such sanitation. Also, in the midst of daily activities, it can be inconvenient to uncap bottles of disinfecting gels or hand lotions to otherwise treat the hands.
Fortunately, it has been established that ethyl alcohol is a most effective antiseptic for gram-negative pathogens; it is of low viscosity, easily dispensed from a portable container, and does not require the use of a material wipe or cloth because of the speed of evaporation. Further, an adequate dose for sanitizing the hands comprises but a few drops of this antiseptic. To prevent chafing, glycerin can be added to the alcohol without levels of viscosity increase that would be deleterious to the dispensing process.
Various methods of portable disinfectant or lotion dispensers have been disclosed in the prior art. These include body-mounted dispensers, wrist bracelet dispensers, and others. U.S. Pat. No. 6,371,946 discloses a dispensing tube that drips liquid onto the hand. U.S. Pat. No. 6,053,898 discloses a tube-fed finger dispenser. A body-worn dispenser of form factor similar to a pager is disclosed in U.S. Pat. No. 5,927,548.
What has not been demonstrated is a dispenser that is wrist- or arm-worn that provides ease of actuation and, more specifically, single hand actuation. Neither has there been a device that can be surreptitiously actuated. This is an important consideration with respect to public relations. Individuals such as business and sales personnel may come in contact with and greet many people during the day. It would be desirable to have the option of sanitizing the hands after a handshake with a person without conveying a disdainful message to that person in so doing.
A wrist-mounted dispenser that achieves dispensing directly to the hand with a simple hand action is a major advantage of the present invention. This is especially useful to nurses and doctors in busy hospital settings, as well as for allied healthcare workers who cannot take time to repeatedly wash their hands with soap and water. With the advent of new forms of communicable disease such as SARS, an important consideration regards means to prevent disease spread. In this vein, the present invention provides a dispensing modality for viricidal and antibacterial prophylactic treatments of the hands and other exposed parts of the body.

Portable device for dispensing skin treatments


The present method and system provides for call center simulation including receiving a plurality of input parameters relating to call center operations, wherein the call center operations include a main queue for processing on-hold calls and a virtual queue for processing a plurality of call back requests. The method and system further includes generating a call arrival dataset based at least on the plurality of input parameters and simulating call center operations for managing the call arrival dataset across the time sequence, including placing a portion of the call arrival dataset into the virtual queue. The method and system includes simulating a metering of the call arrival dataset in the virtual queue for a metered wait time based at least on a queuing factor and generating a simulation output indicating operations processed via the main queue and the virtual queue.

The present invention relates generally to call center management operations and more specifically to simulation operations relating to call center operations, where the simulations account for a virtual queuing of customer calls.
Call centers receive calls from numerous customers. The high volume of calls often necessitates the use of call queues in which the customers must wait until an agent of the call center is available to assist the caller. However, in call systems utilizing virtual queuing, a customer may opt to receive a call back from an agent of the call center instead of waiting on the phone. If so, the call remains in the queue of the call center, but the customer may disconnect from the call. When the customer's call reaches the head of the queue, the call center calls the customer back and connects the customer to an agent. As such, in typical virtual queuing systems, each call is queued either normally (i.e., the customer waits on the line) or virtually (i.e., the customer is called back). Such functionality occurs completely within the call center and may require additional devices, components, software, and structure to provide the virtual queuing functionality.
Customer service interactions and call center activities are major cost factors for companies. These call centers are both essential to managing customers, but also relate directly to customer relations and satisfaction. Call centers themselves seek operation as maximum efficiency for not only solving the concerns of the customer, but also for managing staffing of service agents. A company seeks to find an economic medium between the staffing of call centers and managing customer expectations for service operations.
Staffing analytics and call management systems seek to optimize the staffing requirements of call centers, but these existing systems fail to account for virtual queuing techniques. Thus, a call center that utilizes a virtual queue or seeks to understand operational optimization with a virtual queue cannot use the existing simulation or optimization software. These call centers are then unable to better approximate or estimate the staffing requirements throughout various time intervals.
Therefore, there exists a need for workforce management and planning systems to be able to account for virtual queuing and incorporate the effects of virtual queuing in the software simulation operations.

System and method for simulating virtual queuing of calls


A guide assembly for power tools includes a rectilinear guide and a rotary guide slidably attached to the rectilinear guide with a post with axially opposed top and bottom ends respectively. The rotary guide further includes a knob provided with a rod with a first end directly attached to a bottom surface of the knob. The assembly further includes a mechanism for slidably attaching the rotary guide to the rectilinear guide and a mechanism for removably securing the rectilinear guide to a support surface. The removable securing mechanism further includes an opening formed in each of the end caps and located in a central region thereof.

1. Technical Field
This invention relates to tool guides and, more particularly, to a guide assembly for power tools for assisting a user to make accurate cuts easily and quickly when employing power saws and like power tools.
2. Prior Art
Archeological evidence proves that man was using tools at least four million years ago. For thousands of years, their development continued at a steady pace, as better materials and innovations slowly transformed the devices we use to shape the world. After World War II, a new tool market sprang up in the form of homeowners and do-it-yourselfers who wanted to save money by tackling repairs and building projects themselves. This meant creating portable power tools and scaled-down machines that were lighter, easier to use, and more affordable than their industrial-strength predecessors.
Power tools from the 1940s and '50s are some of the most exciting ever created. Especially pleasing to the eye, most were constructed with aluminum bodies, which reflected the styling of the day. Jigsaws and drills often had streamlined, bullet-shaped bodies, which looked like they were developed in a wind tunnel. But, by far, the greatest improvements to power tools were made in comparatively recent power tools.
The best power tools are precision-engineered devices capable of performing their cutting, boring, drilling, sanding, sawing and planking tasks remarkably well. But power tools and the accessories, jigs, and gizmos that go with them are noteworthy objects in and of themselves, symbols of sophisticated building technology and practice. Obviously, it would be advantageous to provide a means for assisting in the precision use of circular saws, jig saws, rotary tools and the like.
U.S. Pat. No. 6,116,304 to Wilson discloses a power tool guide system that includes a base plate and at least one stanchion assembly mounted on the base plate. The system also includes a guide assembly mounted on the stanchion assembly for slidably receiving a power tool thereon above base plate. Unfortunately, this prior art example does not provide a means for attaching the system to a preexisting workbench.
U.S. Pat. No. 6,725,558 to Gommper discloses an adjustable portable power tool guide having a base plate, a base plate cutting edge to define a cut line, an adjustable tool guide rail for guiding a portable power tool cutter adjacent to the cutting edge, and an adjustable control bar that defines a reliable and predetermined angle between the cutting edge and the control bar. Unfortunately, this prior art example does not provide a means for attaching the system to a preexisting workbench.
U.S. Pat. No. 4,489,634 to Volk discloses a table for supporting and guiding diverse portable power tools with precision and safety. In one mode of use with a sabre saw, adjustable guide rails for the saw have free-floating engagement with locator posts on the table and rest directly on the workpiece which is being cut. The guide rails at one end can be raised or lowered for precise leveling and locked in the chosen position. Very smooth cutting by the sabre saw is enabled without chattering of the work piece. In another form of the table there is a second mode of use with a circular saw or router, and the guide rails are supported at a fixed height atop the locator posts and above the top surface of the work piece resting on the table. A work piece protractor guide on the table enables various cutting angles. Precision cutting of cove molding by a sabre or circular saw is possible by proper angular adjustment of the protractor guide and saw blade. The sabre saw can also be used in a ripping mode across the guide rails when the latter are supported at a fixed height atop the locator posts. Unfortunately, this prior art example does not provide a means for attaching the system to a preexisting workbench.
Accordingly, the present invention is disclosed in order to overcome the above noted shortcomings. The present invention satisfies such a need by providing an apparatus that is simple and easy to use, lightweight yet durable in design, and designed for assisting a user to make accurate cuts easily and quickly when employing power saws and like power tools. The guide assembly for power tools provides a user a simple means for ensuring precise operation of various types of power tools. The present invention is simple to use, inexpensive, and designed for many years of repeated use.

Guide assembly for power tools and associated method


A new cultivar of Veronica plant named ‘Verpurg’ that is characterized by its compact and dwarf plant habit, its numerous flowering stems, its re-blooming habit resulting in a long bloom season, its flowers that are intense violet-purple in color, and its strong flower stems.

The present invention relates to a new and distinct cultivar of Veronica spicata and will be referred to hereafter by its cultivar name, 'Verpurg'. 'Verpurg' represents a new herbaceous perennial grown for landscape use.
'Verpurg' arose from open pollination of Veronica 'Verspi' as the female parent. 'Verpurg' originated as a seedling that arose from seed planted from open pollination of Veronica 'Verspi' in 2016. The male parent is therefore unknown. 'Verpurg' was selected as a single unique plant in 2018 from amongst the resulting seedlings.
Asexual propagation of the new cultivar was first accomplished by stem cuttings by the Inventor in July of 2019 in Haarlem, The Netherlands. Asexual propagation by stem cuttings has determined that the characteristics of the new cultivar are stable and are reproduced true to type in successive generations.


Provided are methods, computer programs and apparatus supporting use of generic shortcuts. Generic shortcut sequences are sequences of generic inputs that are defined to an application program to initiate specific operations of the application, and which translate to a respective input sequence receivable from each of a plurality of different types of input device. An application program written to support generic shortcut sequences will initiate specific application operations when received device-specific inputs translate into a sequence of generic inputs and the sequence includes a generic shortcut sequence. An event translator applies mappings between receivable device-type-specific inputs and respective generic inputs, to allow received input sequences to be translated into sequences of generic inputs. The resulting sequences of generic inputs are compared with defined generic shortcut sequences. If a match is identified between the sequence of generic inputs (generated by translating received device-specific inputs) and a defined generic shortcut sequence, the generic shortcut sequence initiates its respective application operation.

Application programs written for 'pervasive' computing environments may be used by a number of different types of computing devices. The different computing devices may use different types of input devices such as a microphone (or other speech input), a mouse, a keypad or a keyboard. Not all devices have the same capabilities or are usable in the same manner. For example, a microphone and a mouse do not have keys, while a keypad does not have a "mute" feature. Even when similar capabilities are available, they may be reduced. For example, a keypad on a telephone does not directly have alphabetic keys.
Shortcuts are abbreviated input sequences that are defined to perform the same action as an application interaction sequence (typically a longer input sequence). If an original, formal input sequence is long or complex, a shortcut can provide an efficient and convenient alternative. Shortcuts may be implemented using application elements such as macros, voice prompts, icons or hot keys (combinations of keys of a computer keyboard that can be pressed together to efficiently initiate an operation). A shortcut input sequence via a keyboard may begin with a designated input such as the Ctrl key, Alt key or a function key (F1 to F12). Shortcuts have been found to be very useful in conventional data processing applications.
For example, the Ctrl-S ("Control" followed by "S") sequence can be used to save a document in many application programs written for a Windows™ operating system. In Web applications, where shortcuts can be macros for navigation sequences across multiple pages, the sequence Alt-O may be used for "login using default account information in wallet and order products already in the shopping cart".
However, shortcuts are typically defined with respect to a single input device and are usable only for that type of device. Therefore, if an application program can receive inputs from multiple devices (such as a mouse, keyboard and voice input via a microphone), the application developer must decide whether or not to implement shortcut support for each device type. Faced with the task of providing multiple device-type-specific shortcuts to enable each input device to initiate the same application feature, such as saving a file, developers may decide to omit shortcut support for many device types.
U.S. Pat. No. 6,091,409 describes Internet 'shortcut objects' encapsulating location information (such as a URL) and represented by Windows™ desktop icons. The objects can be opened by a number of different user operations that activate the Web Browser—such as positioning the mouse cursor over the icon and pressing mouse buttons or via menu selection (File and then Open). However, U.S. Pat. No. 6,091,409 and related patent U.S. Pat. No. 5,877,765 do not disclose generic or device-independent shortcuts.
U.S. Pat. No. 5,864,605 describes voice menu optimization using 'shortcuts'. A shortcut message in a voice menu prompts a caller to select a shortcut button that initiates an action. The shortcut button corresponds to a sequence of a plurality of dialling buttons. U.S. Pat. No. 5,864,605 does not disclose generic or device-independent shortcuts.
When developing application programs that need to accept input from a plurality of input device types (e.g. for pervasive computing environments), a generic application model and platform-independent language may be used, such as XForms. XForms is described in the W3C's 'XForms 1.0' Recommendation of 14 Oct. 2003 (at the time of writing, this specification is available at Website URL: 'www.w3.org/TR/2003/REC-xforms-20031014/'). An XForms application includes three separate elements: a device-independent XML form definition comprising a set of form controls describing what the form does; a separate interface description section describing how the form is to be presented; and XML instance data. The generic model can be translated into a number of different versions of the application, which each take account of the capabilities of a particular input device type. For example, a first application version may be provided for invocation by a Web Browser supporting XHTML, and a second version for invocation from a WML-compliant mobile telephone. A goal of XForms is to support Browsers on different types of device (hand-held devices, televisions and desktop computers). However, XForms does not provide support for reusable shortcuts across devices.

Methods, apparatus and computer programs supporting shortcuts across a plurality of devices

International Business Machines Corporation


An image sensor includes a plurality of light detecting elements. The plurality of light detecting elements are arranged in a plurality of rows and a plurality of columns, wherein a flat field picture generated by the image sensor, the intensity standard deviation of pixels in each pixel column is greater than that of pixels in any pixel row, or the intensity standard deviation of pixels in each pixel row is greater than that of pixels of any pixel column.

1. Technical Field
The present invention relates to an image sensor and an optical touch system comprising the same.
2. Related Art
In an optical touch screen system, the method of calculating the position of an object is to use an image sensor to generate a picture, analyzing the location of an object image in the picture, calculating the coordinates of the object according to the location of the object image in the picture and a portion of geometric dimensions of the optical touch screen system.
U.S. Pat. No. 4,782,328 discloses an optical touch screen system, which comprises two image sensors configured to capture the image of an object on a touch screen. A processor is coupled with the two image sensors for processing the images from the two image sensors in order to decide sensing paths respectively connecting the object and the two image sensors, and further calculates the coordinates of the object using the sensing paths.
U.S. Pat. No. 7,689,381 B2 discloses another optical touch screen system, which comprises a mirror, two light sources, an image sensor, and a processor. The mirror and the two light sources are disposed at the border of a touch area. The mirror can generate a reflection of an object. The image sensor can capture an image of the object and an image of the reflection. The processor can determine sensing paths passing through the image of the object and the image of the reflection, and then determine the coordinates of the object by the two sensing paths.
Usually, in an optical touch screen system, it is difficult to have uniform background light. In order to precisely determine an object image, the influence of non-uniform background illumination has to be eliminated before the analysis of the object image. A general method is to store a to background picture in advance, subtracting the background picture from a captured picture, and then lastly analyzing the subtracted picture to determine the object image. To perform the aforementioned method, an optical touch screen system always has to store a background picture, which needs a large memory space for storage. Further, the background illumination may change so that the background picture has to be frequently updated, which increases the operation loadings on the optical touch screen system. In addition, the computing procedures of subtracting a background picture from a picture, analyzing the boundary positions of the object image in the subtracted picture, and calculating the coordinates of the object according to the boundary positions consumes a large amount of electrical energy. Furthermore, the optical touch screen system needs a faster clock to be more responsive.

Image sensor and optical touch system including the same


A splicing device and splicing method in which automatic and accurate splicing is performed by inserting two carrier tapes into the device. The splicing device including cutting devices for cutting the tail end of number one carrier tape and the leading end of number two carrier tape at a predetermined cutting position; a positioning device for indexing number one and number two carrier tapes towards each other respectively to splicing position at which positioning pins engage with indexing holes of the number one and number two carrier tapes; and a joining device which, with splicing tape affixed to connected protective tape positioned at the splicing position, folds protective tape and joins the splicing tape to both surfaces of number one and number two carrier tapes straddling thereof.

Typically for component mounters, a carrier tape holding multiple electronic components at fixed intervals is wound onto a reel, and by moving a sprocket which engages in indexing holes provided in the carrier tape, the carrier tape is indexed a fixed amount each time so that an electronic component is supplied to a supply position, and the component is picked up by a suction nozzle and mounted onto a circuit board.
For this type of component mounter, when the remaining quantity of electronic components held in one reel becomes small, the leading end of a carrier tape wound around a different reel which holds the same type of electronic component is connected using splicing tape to the tail end of the carrier tape for which the remaining quantity has become small, in other words, splicing is performed. An item with this type of splicing function is disclosed, for example, in PTL 1.


Incoming communications received by call centers and the like are routed to one or more alternative call centers based on a comparison of Match Rates and Expected Wait Times. Such routing helps improve the overall load balancing of a call center or network of call centers while increasing the effectiveness and controlling the costs of handling incoming communications.

Many businesses today have offices in more than one location. For example, a large corporation may have its corporate headquarters in New York, manufacturing facilities in Virginia and research and development laboratories in California. As a result, a businesses' employees may be spread out as well. Many businesses have purchased equipment and associated software referred to as "call centers" or ("contact centers"). Generally speaking, a call center is used to distribute incoming "calls (hereafter the word "call" or "calls" is used to indicate any number of incoming communications or communication types, such as voice calls, voice mail, facsimile, voice-over-IP, emails, instant messages, Internet-based web chats, collaborative Internet sessions, or any other type of incoming communication that can be handled by a customer service representative or the like) to a business' employees. Call centers have become more sophisticated over the years. Today, some call centers have the ability to route an incoming call to an employee who has a specialized skill or expertise in order to answer/satisfy the specialized questions/needs of incoming callers.
A business may have more than one call center linked together. For example, each such "multi-site" call center might be responsible for distributing calls to a particular subset of employees who have specific skills or expertise. An advantage of having a linked arrangement of call centers is that when an incoming call is received by one call center, and this "original" call center determines that the available employees (referred to as "agents") connected to it do not have the requisite skills or expertise to meet the needs of the incoming call in a timely fashion, the original call center can route the call to an "alternative" call center that is capable of promptly directing the call to a qualified, available agent. In general, it is preferable to place incoming calls into a "queue" associated with a center which has a short wait time, rather than a long wait time, in order to enhance customer satisfaction and reduce the chance that callers will hang up before an agent answers the call.
When caller wait time is the chief concern, many conventional call centers use techniques that change how work is handled in order to reduce wait time. For example, in some cases calls are moved from one "queue" to another, where wait times are expected to be shorter or where agents are available to take the call immediately. The agent that services such a "re-queued" caller, however, is typically not the first choice in agent type (i.e., does not have the ideal abilities or specialized knowledge needed to answer a caller's question), and, therefore, may provide a service which is less efficient, less effective, or costs more than an agent who is more ideally suited to service this type of call.
The criteria to determine whether a call should be routed to another call center and/or which call center, among many, should be the target of the routed call, vary. Increasingly, some businesses want to use a criterion called "Match Rate". So it is clear, many techniques for routing calls can involve a transaction in which one value or criteria is matched with another. See for example, U.S. Pat. No. 5,206,903 to Kohler, et. al assigned to the same assignee herein. It should be emphasized, however, that as used herein, the term "Match Rate" has a different and more specialized meaning. Specifically, as used herein, the term Match Rate should be understood as a cumulative measurement (i.e., a "running tally"), instead of a successful "match" of caller or call to agent. More specifically, the Match Rate to which the present invention is directed is a measurement of what percentage of calls needing a particular skill or expertise set are answered by agents who are ideally suited to serve the contact, rather than by agents who are less than ideally suited to do so.
Some existing techniques route calls to agents based on a set of skills. Others are capable of selecting a queue with the shortest wait time served by qualified agents from among many queues in order to minimize wait times. The latter techniques are sometimes referred to as "load balancing" techniques.
To date, however, the inventors are not aware of a technique which allows calls to be balanced based on a combination of wait times and a Match Rate.
Accordingly, it is a desire of the present invention to provide for methods and devices for balancing calls, such as incoming calls, based on a Match Rate and wait times.
It is a further desire of the present invention to balance calls based on a Match Rate and wait times which is associated with a particular set of skills or expertise.
Further desires will become apparent from the drawings, detailed description of the invention and claims which follow.

Methods and devices for balancing communications using match rates


The integration of genes into methylobacterium, such as M. extorquens ATCC is disclosed, using a transposon system, preferably the mini-Tn7 transposon system, and under the control of a promoter, such as the strong methanol dehydrogenase promoter (PmxaF). Multicopy integration of genes of interest is also disclosed. The unique and specific attachment site for the Tn7 attachment (attTn7) is identified for M. extorquens.

Methylobacterium extorquens is a pink-pigmented facultative methylotroph (PPFM) capable of growth on simple and inexpensive single-carbon compounds, such as methanol, as the sole carbon and energy source in a completely synthetic mineral salt medium (Bourque et al., 1992). These simple requirements combined with the fully automated nutrient non-limiting high cell density fed-batch bioprocesses developed for M. extorquens ATCC 55366 (Bourque et al, 1995; Bélanger et al., 2004; Beland et al., 2004), render large-scale M. extorquens fermentations very cost-effective. This feature, along with the availability of genetic tools (Marx and Lidstrom, 2001; Figueira et al., 2003; Choi et al., 2004) and abundant genome sequence information and stoichiometric models for evaluating its metabolic capabilities (Van Dien and Lidstrom, 2002), makes M. extorquens very interesting economically as a host for the production of recombinant proteins. Overexpression in M. extorquens of recombinant green fluorescent protein, esterase from Lactobacillus casei, catechol 2,3-dioxygenase from Pseudomonas putida, enterocin P from Enterococcus faecium, and haloalkane dehalogenase from Xanthobacter autotrophicus have been described in the literature (Fitzgerald and Lidstrom, 2003; Bélanger et al., 2004; Choi et al., 2004; Gutierrez et al., 2005).
Methylobacterium strains are ubiquitous in nature, inhabiting soils (Sy et al., 2001), sediments and fresh water environments (Rickard et al., 2002). Methylobacterium strains have also been detected and isolated from the surface of leaves from almost all plants tested (Romanovskaya 2001; Omer et al., 2004; Koopman and Kutschera, 2005; Gallego et al., 2005). Furthermore, there are a growing number of reports describing favourable interactions between PPFMs and plants. M. extorquens has been described as an endophytic microorganism, found in the stem and leaves of citrus plants (Lacava et al., 2004), as a bud endophyte of Scots pine (Pirttila, 2000), and in the rhizosphere of flowering plants (Idris et al., 2004).
Recently, our laboratory has successfully cloned and expressed in M. extorquens the cry1Aa gene. The toxin protein encoded by cry1Aa is highly active against the spruce budworm, a powerful forest defoliating pest. These observations in view of the ubiquitous nature of M. extorquens in the environment and the ease by which the strain can be genetically transformed to over-express recombinant proteins, suggests that this microorganism could be utilized as an attractive delivery system of recombinant biocontrol agents against crop and forest insect pests. However, the utilization of expression systems in the environment or under high cell density fermentation bioprocesses can be problematic. The reason for this being plasmid segrational instability in the absence of selective pressure. The loss of plasmid and consequently the loss of expression of the desired recombinant product occurs gradually but surely under growth conditions where antibiotics cannot be used for practical or safety issues. We have shown in a previous study (Bélanger et al., 2004) that approximately 50% of recombinant expression is lost following 15 generations of growth in the absence of selective pressure in M. extorquens. Integration of expression cassettes in bacterial chromosomes would not necessitate the use of antibiotic selection for the stable expression of recombinant products. It has been recently shown that the Tn7 system integrates, in a stable and site-specific manner, recombinant DNA fragments into a site of the chromosome called attTn7. This attTn7 is located in the intergenic region downstream of the glmS gene in many Gram negative bacteria such as E. coli, Klebsiella pneumonia, Serratia marcescens, Pseudomonas putida and Yersinia pestis (Craig, 1989; Lichtenstein and Brenner, 1982; Choi et al., 2005).

Multicopy-integration of heterologous genes and expression in


A system is described whereby a cloud router may allow routing as a service in a cloud-like manner. In an example, an apparatus may include a processor and a memory coupled with the processor that effectuates operations. The operations may include receiving first routing information associated with a first customer edge device; adding the first routing information to network routing information of the apparatus, wherein the network routing information comprises a network routing table with routes for a plurality of networks; and propagating the network routing information to a software defined network (SDN) controller, wherein, based on the network routing information, the SDN controller sends a forwarding information base (FIB) to a provider edge device connected with the first customer edge device.

Communication networks have migrated from using specialized networking equipment executing on dedicated hardware, like routers, firewalls, and gateways, to software defined networks (SDNs) executing as virtualized network functions (VNF) in a cloud infrastructure. To provide a service, a set of VNFs may be instantiated on general-purpose hardware. Each VNF may require one or more virtual machines (VMs) to be instantiated. In turn, VMs may require various resources, such as memory, central processing units (CPUs), and network interfaces or network interface cards (NICs).
This background information is provided to reveal information believed by the applicant to be of possible relevance. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art.