A waveguide structure comprising a medium disposed of a sensing layer (21), a second layer of material (22) having a refractive index greater than that of the medium, and a substrate (24). The structure defines a waveguide capable of supporting an optical mode confined in a sensing layer. The medium is adapted for performing chemical or biological reactions within the medium which will result in a change of an optical property of the sensing layer of the waveguide. The thickness and refractive indexes of the layers are chosen such that an optical mode confined in the sensing layer will suffer substantially anti-resonant reflection as a consequence of the interface between the sensing layer and the second layer and the interface between the second layer and the substrate. Alternatively, the waveguide may comprise a low index sensing medium held between a superstrate and a substrate each of which has a refractive index higher than that of the medium. The waveguide may be capable of supporting two modes, such that one of the modes may be used as a reference during measurement of optical properties of a medium. The waveguide may be capable of supporting a leaky waveguide mode, the presence of the leaky waveguide mode being indicated by a peak of light returned from the waveguide.

This invention relates to waveguide structures, and particularly though not exclusively to waveguide structures suitable for use as optical sensors.
Sensors which are capable of monitoring biological interactions in real time and with high sensitivity are of considerable importance in life science research. Several sensors exist which monitor changes in the refractive index (or other parameters) of a biological sample, caused by molecular interactions. In a typical sensor an evanescent wave associated with an optical mode existing in a high refractive index dielectric layer of a waveguide extends into a biological sample, which is held in a gel. A change of the refractive index of the sample will modify an optical property of the waveguide mode, and detection of this change will provide dynamic information relating to interactions occurring within the biological sample.
Known optical evanescent sensors include those based on surface plasmon resonance and those based on dielectric waveguiding techniques (see for example Welford, K (1991) Surface plasmon-polaritons and their usesxe2x80x94Optical and Quantum Electronics, 23, 1-27; Smith, A. M. (1987) Optical waveguide immunosensors, Proc. SPIE 798 Fibre Optic Sensors II, 206-213); R. H. Ritchie, Phys. Rev. 106, 874 (1957).
Sensors which use surface plasmon resonance comprise a thin metal layer (typically a few tens or hundreds of Angstroms thick) deposited onto a dielectric prism or grating, and a sensing layer (or a fluid) whose optical properties are of interest provided at an opposite surface of the metal layer. Measurements are made by directing light via the prism or grating onto that side of the metal layer which is not in contact with the sensing layer, and detecting light which is reflected from the same side of the metal layer. A surface plasmon resonance excited by the incident light will result in the absorption of that incident light, and a consequent dip in the reflected light intensity. The condition for exciting a resonance (i.e. the angle of incident light which will excite a resonance) is sensitive to changes in the optical properties of the sensing layer. The optical properties of the sensing layer may be monitored by detecting changes in the angle of incidence which excites a resonance
The resolution, and hence the sensitivity, of sensors which utilise surface plasmon resonance is limited by the resonance width (i.e. the range of angles of incident light which will excite resonance). This width is determined ultimately by the amount of absorption of incident light into the metal layer. Absorption is considerable at wavelengths commonly used for biological measurements, and the maximum resolution of surface plasmon sensors is correspondingly restricted.
The angle of incident light which excites a surface plasmon resonance will alter if the wavelength of the incident light is changed. Variations in the wavelength of incident light will thus introduce an error into measurements. This is a further limitation of surface plasmon resonance sensors, since wavelength-stabilised sources of incident light are needed to allow accurate measurement.
A waveguide structure, based upon the surface plasmon resonance structure and known as a leaky mode waveguide, is described by R. P. Podgorsek, H. Frarke and J. Woods (1998) Monitoring of the Diffusion of Vapour Molecules in Polymer Films using SP-Leaky-Mode Spectroscopy, Sensors and Actuators B-Chemical, Vol.51, No.1-3, pp.146-151. The waveguide comprises a substrate, a thin metal layer disposed on top of the substrate, and a sensing layer whose optical properties are of interest disposed as a further layer on top of the layer of metal. The sensing layer has optical properties which change if the medium is exposed to conditions to be sensed, and may be for example dextran gel.
The leaky mode excited within the sensing layer is of a type known in the art as a bulk mode. This contrasts with the mode which is excited by surface plasmon resonance sensors, which mode is known in the art as a surface mode. Generally only one mode may be excited in surface plasmon sensors (the mode must be a TM mode), whereas the leaky mode waveguide allows the excitation of a series of modes (the modes may be any combination of TE and TM).
A leaky mode of the waveguide, i.e. a bulk mode which is centred on the sensing layer, is excited by directing light towards the layer of metal or metal alloy through the substrate over a range of incident angles. The presence of an excited leaky mode is determined by detecting the intensity of light returned from the waveguide over a range of angles. When light is coupled to a leaky mode of the waveguide this is seen as a dip in the intensity of light emitted from the waveguide. A change of an optical property of the sensing layer will modify the angle of incident light required to excite the leaky mode. The angle at which the dip of intensity is returned from the waveguide will change accordingly.
The leaky mode waveguide is advantageous compared to surface plasmon resonance because a bulk mode of the waveguide is excited rather than a surface mode. This bulk mode is centred on the sensing layer of the waveguide and is therefore considerably more sensitive to changes of the optical properties of the sensing layer than the surface mode provided by surface plasmon resonance.
A disadvantage of known leaky mode waveguides is that detection optics are required to detect a dip in the intensity of light returned from the waveguide, and to follow angular movement of that dip. The absence of light is inherently more difficult to detect than a peak of light intensity.
It is an object of the invention to provide a leaky mode waveguide which will return a peak of intensity when a leaky waveguide mode is excited.
According to a first aspect of the invention there is provided an optical sensor comprising a waveguide having a substrate, a layer of metal or metal alloy disposed on top of the substrate, and a medium disposed as a sensing layer on top of the layer of metal or metal alloy, the medium having optical properties which change if the medium is exposed to conditions to be sensed, the sensor further comprising means for directing light towards the layer of metal or metal alloy through the substrate over a range of incident angles, and detection means for detecting the intensity of light returned from the waveguide over a range of detection angles, the means for directing light being configured to direct light such that a leaky waveguide mode is excited within the sensing layer, and the means for detecting the intensity of light being arranged to detect variations with detection angle in the intensity of returned light resulting from the excitation of the leaky waveguide mode; characterised in that the waveguide is configured such that the overlap of the optical field with the layer of metal or metal alloy is less for light incident at an angle which results in excitation of a leaky waveguide mode than for light incident at an angle which does not result in excitation of a leaky waveguide mode, whereby the detected intensity peakswat a detection angle related to an incident angle which results in excitation of a leaky waveguide mode.
The invention is advantageous because it allows for the easy detection of a waveguide mode.
The term metal alloy is intended to include mixtures of metals and mixtures of two or more elements which include at least one metal. Metals or metal alloys are used because they have a sufficiently high imaginary part of refractive index that an optical field extending into the metal or metal alloy suffers significant loss. The term metal or metal alloy is therefore intended to include any material having an imaginary part of refractive index comparable to that of a metal or metal alloy.
Preferably, the substrate comprises a prism or grating for coupling light into the waveguide mode.
An optical source comprising a laser, a light emitting diode or a source capable of producing a broad spectrum of wavelengths of light may be used to provide the incident light. The use of a light emitting diode, or a broad band source, is made possible by the relative wavelength insensitivity of the waveguide mode of the invention.
The detection means is preferably a charge-coupled-device array (CCD) comprising cells of sufficiently small dimensions to allow resolution of the intensity variations resulting from the excitation of the waveguide mode.
The detection means may comprise a single photo-diode which is capable of being translated across the light returned by the waveguide. By translating the photo-diode through a series of positions, the photo-diode may be made to provide a measurement of intensity at each position, thereby giving a measurement similar to that which will be provided by the CCD array.
The thickness of the layer of medium is preferably greater than 200 nm, and most preferably greater than 300 nm. The layer of medium is required to be thicker than that typically used for surface plasmon resonance sensors, in order to support the waveguide mode which is excited within the medium.
According to a second aspect of the invention there is provided a method of optical sensing comprising providing a waveguide comprising a substrate, a layer of metal or metal alloy disposed on top of the substrate, a medium disposed as a sensing layer on top of the layer of metal or metal alloy, the medium having optical properties which change if the medium is exposed to conditions to be sensed, directing light towards the layer of metal or metal alloy through the substrate over a range of incident angles, and detecting the intensity of light returned from the waveguide over a range of angles, wherein the incident light is directed such that a waveguide mode is excited within the sensing layer, and variations in the intensity of returned light resulting from the excitation of the waveguide mode are detected; characterised in that the waveguide is configured such that the overlap of the optical field with the layer of metal or metal alloy is less for light incident at an angle which results in excitation of a leaky waveguide mode than for light incident at an angle which does not result in excitation of a leaky waveguide mode, whereby the detected intensity peaks at a detection angle related to an incident angle which results in excitation of a leaky waveguide mode.
A disadvantage of conventional waveguides used for optical sensing is that they do not provide an optical mode centred on a sensing layer. This problem is overcome by the leaky mode waveguide.
A limitation of the leaky mode waveguide is that leaky modes are sensitive to changes of the dimensions of the layers comprising the waveguide. The waveguide must therefore be made with tight fabrication tolerances.
It is an object of the present invention to provide a waveguide structure which overcomes or mitigates the above disadvantage.
According to a third aspect of the invention there is provided a waveguide structure comprising a medium disposed as a sensing layer, a second layer of material having a refractive index greater than that of the medium, and a substrate, wherein the structure defines a waveguide capable of supporting an optical mode confined in the sensing layer, the medium is adapted for performing chemical or biological reactions within the medium which will result in a change of an optical property of the sensing layer of the waveguide, and the thickness and refractive indices of the layers are chosen such that an optical mode confined in the sensing layer will suffer substantially anti-resonant reflection as a consequence of the interface between the sensing layer and the second layer and the interface between the second layer and the substrate.
The sensing layer is bounded on one side by a material whose refractive index is lower than that of the sensing layer.
The reference in the statement of invention to a mode being confined in the sensing layer of the waveguide structure is intended to mean that the mode is centred on that layer of the waveguide, and it will be appreciated that a proportion of the mode will extend beyond that layer.
The inventors have realised that anti-resonant reflecting optical waveguides (ARROW""s) may be used to concentrate an optical field in a sensing region having a low refractive index. Since biochemical sample separation, antibody-antigen interactions, etc. are usually carried out in low index layer (dextran gel, a polymer or other suitable medium), ARROW waveguides allow concentration of an optical field in a region in which a chemical or biological reaction is to take place (i.e. the sensing layer of the above waveguide structure).
According to a fourth aspect of the invention there is provided a waveguide structure comprising a medium disposed as a sensing layer, a second layer of material having a refractive index greater than that of the medium, and a substrate, wherein the structure defines a waveguide capable of supporting an optical mode confined in the sensing layer, the medium is adapted for performing chemical or biological reactions within the medium which will result in a change of an optical property of the sensing layer of the waveguide, and the thickness and refractive indices of the layers are chosen such that an optical mode confined in the sensing layer will suffer substantially resonant reflection as a consequence of the interface between the sensing layer and the second layer and the interface between the second layer and the substrate.
The use of a resonant reflection to confine the optical mode, rather than an anti-resonant reflection, is advantageous because it renders the optical mode more sensitive to a change of an optical property of the sensing layer of the waveguide. Waveguides configured to provide an optical mode confined by resonant reflection are hereafter referred to as resonant optical waveguides (ROW""s).
The medium adapted for performing chemical or biological reactions in the ARROW or ROW waveguides is preferably dextran gel, but may be any other suitable low-index material.
Preferably, the ARROW or ROW waveguide structure is adapted for use as part of an optical sensing apparatus.
Preferably, the optical sensing apparatus comprises the waveguide structure, an optical source, means for coupling light from the optical source into an optical mode confined in the sensing layer of the structure, and means for detecting changes in the properties of the optical mode by monitoring properties of light coupled from the waveguide structure.
Preferably, the coupling means comprises a prism which is located against or adjacent the substrate of the waveguide structure, the prism being configured to allow light to be coupled into a resonant optical mode confined in the sensing layer of the structure, when the light is incident upon the prism at a predetermined angle. A change of the refractive index of the sensing layer of the structure will modify the angle which will excite a resonant mode of the waveguide structure
Preferably, the optical sensing apparatus is provided with means for scanning the light from the optical source so that it is incident at the waveguide over a range of incident angles. This may be done for example by mounting the optical source on a swinging arm. In the alternative, means may be provided to direct light from the optical source onto the waveguide from many angles simultaneously.
Preferably, the optical sensing apparatus is provided with means for providing light capable of exciting both TE and TM modes confined in the sensing layer of the waveguide structure, and means for producing interference between light coupled from the TE and TM modes, once it has been coupled out of the waveguide structure.
The optical source used to excite an ARROW waveguide mode may be a light emitting diode, or may be capable of producing a broad spectrum of wavelengths of light. The use of a light emitting diode, or a white light source, is made possible by the relative insensitivity of the ARROW mode index to variations of the wavelength of incident light. If a narrow wavelength band of incident light is required, a laser may be used as the light source. A narrow wavelength band will be required to excite a ROW waveguide mode.
The optical apparatus may include means for detecting a dip in the intensity of the light coupled from the waveguide. Should the waveguide structure cause scattering or absorption of light confined within the sensing layers a dip in the intensity of light coupled from the waveguide will indicate the presence of a waveguide mode.
The waveguide structure may be provided with a low index spacer layer located between the second layer and the substrate. The low index spacer layer is advantageous because it allows ARROW modes and resonant mirror modes to be excited in a single waveguide, thereby allowing comparison between them. The low index spacer may similarly allow the simultaneous excitation of ROW modes and resonant mirror modes.
The waveguide structure may be arranged to cause scattering or absorption by the introduction of scattering or absorbing elements in the sensing layer or the second layer of the waveguide, or by providing either of those layers with roughened surfaces. Where the waveguide structure includes a low index spacer layer. scattering or absorbing elements may be introduced into the spacer layer. The spacer layer may be provided with roughened surfaces.
The waveguide structure may be provided with a further layer spaced apart from the second layer by a layer of lower refractive index, the further layer having a refractive index greater than that of the sensing layer. The introduction of this extra layer will decrease the losses suffered by a mode confined in the first layer of the waveguide, and will decrease the range of angles of incident light which may be used to excite a resonant mode confined in the sensing layer of the waveguide structure.
The waveguide structure may be provided with a fourth layer located on an uppermost surface of the sensing layer, the fourth layer being material with a similar refractive index to the second layer, and a fifth layer of substrate located on top of the fourth layer. The sensing layer will thus effectively be bounded on both sides by ARROW or ROW structures. This structure may be referred to as a symmetric ARROW structure or symmetric ROW structure, although the corresponding layers on either side of the sensing layer are not required to be of identical thickness or to have the same refractive index. In this configuration, the sensing layer may consist of a fluid that may be allowed to flow through the waveguide structure. This configuration allows an optical mode to be confined in the fluid, and thereby allows the properties of the fluid to be monitored.
Optical sensing apparatus for use with a waveguide comprising the above symmetric waveguide structure may include means for detecting a dip in the intensity of the light coupled from the waveguide. Resonant modes of the waveguide will be manifest as dips in the intensity of light reflected from the waveguide structure or peaks in the intensity of light transmitted by the waveguide structure
The optical apparatus may be configured to detect the presence of gases or chemicals suspended in the air, water or other fluid. One way in which this may be done is by forming the sensing layer of the waveguide structure from a polymer or other material whose refractive index, density or other property is sensitive (i.e. altered) by the presence of that chemical or biochemical species that is to be detected.
The optical apparatus may be arranged to monitor changes of the refractive index of the sensing layer of the waveguide structure, or alternatively the apparatus may be arranged to monitor fluorescence or absorption within the sensing layer.
According to a fifth aspect of the invention there is provided a method of optical sensing, comprising coupling light into a mode confined in the sensing layer of a waveguide structure described in accordance with the third aspect of the invention or the fourth aspect of the invention, coupling light out of the waveguide structure using a prism, and monitoring the angle at which coupling of light to the mode passes through a resonance.
The method may include coupling white light into a mode confined in the sensing layer of the waveguide structure described in accordance with the third aspect of the invention, thereby allowing the spectroscopic analysis of biological samples.
It is an object of the present invention to provide an alternative waveguide structure which supports an optical mode centre on a sensing layer.
According to a sixth aspect of the invention there is provided a waveguide comprising a sensing layer of a medium, a second layer forming a lower surface of the medium and having a refractive index greater than that of the medium, and a third layer forming an upper surface of the medium and having a refractive index greater than that of the medium, wherein the medium is adapted for performing chemical or biological reactions within the medium which will result in a change of an optical property of the sensing layer of the waveguide, and the waveguide is capable of supporting an optical mode centred on the sensing layer.
The waveguide, which will be referred to as a light condenser, is advantageous because its structure is very simple, and it is robust with respect to environmental changes (for example temperature fluctuations).
The light condenser mode is centred on the sensing layer, thereby providing sensitive measurement of changes of the optical properties of the medium comprising the sensing layer.
According to a seventh aspect of the invention there is provided a waveguide comprising a sensing layer of a medium, a second layer forming a lower surface of the medium and having a refractive index greater than that of the medium, and a third layer forming an upper surface of the medium and having a refractive index less than that of the medium, wherein the medium is adapted for performing chemical or biological reactions within the medium which will result in a change of an optical property of the sensing layer of the waveguide, and the waveguide is capable of supporting an optical mode centred on the sensing layer
The waveguide according to the seventh aspect of the invention provides a light condenser reflection at the interface between the layer of medium and the second layer, and conventional total internal reflection at the interface between the layer of medium and the third layer.
A known construction of optical sensor, referred to as a resonant mirror biosensor, attempts to combine the sensitivity of waveguiding devices with the simple construction and use of surface plasmon resonance devices (see Cush, R. et al (1993) The resonant mirror, Biosensors and Bioelectronics, 8, 347-353). The resonant mirror biosensor is similar in construction to a surface plasmon resonance device. A sensing layer, i.e. the material whose optical properties are to be monitored, is placed in contact with a high refractive index layer. The refractive index and thickness (typically about 100 nm) of the high index layer are selected in such a way that the sensitivity of the sensor is maximised. This high index layer is separated from a prism by a layer of lower refractive index material, called the spacer layer (e.g. silica). The refractive index and thickness (typically about 0.5 microns) of the lower index layer are selected such that the sensitivity of the sensor is maximised and/or the sharpness of the Resonant Mirror resonances are maximised. The sensitivity of the sensor and sharpness of the modes can be controlled by altering the refractive index or thickness of the high index layer and spacer layer. The refractive index of the prism also controls the sensitivity of the sensor and sharpness of the modes. The refractive index of the prism must be higher than the mode index of the Resonant Mirror modes.
The resonant mirror differs from conventional waveguide sensors in that the mode excited in the waveguide sensor is leaky in nature. This feature, which may also be seen in surface plasmon resonance waveguides, allows light to be coupled into and out of the resonant mirror via the prism.
Efficient coupling of light to the high index dielectric layer occurs only for certain angles of incident light where phase matching between an incident beam and resonant modes of the high index dielectric layer is achieved. At a resonant point, light couples into the high index dielectric layer and propagates some distance along the sensing interface before coupling back into the prism. An evanescent wave associated with the resonant modes of the high index dielectric layer will extend into the sensing layer. Changes of optical properties of the sensing layer will alter the properties of the resonant modes of the high index dielectric layer. Generally, the thickness of the high index dielectric layer is made very low, in order to maximise the proportion of the optical mode in the evanescent field interacting with the sensing layer, and so maximise the sensitivity of the device. The thin waveguiding layer generally provides a single waveguide mode (one TE mode and/or one TM mode).
Leaky resonant mirror modes in the resonant mirror biosensor may exist for both TE and TM polarisations, and are seen as fine structure in the reflected light once it has passed through an output analyser. The angles of incidence which excite modes of the high-index layer are sensitive to changes in the sensing layer, and so changes caused by assay reactions in the sensing layer may be monitored by measuring shifts in the excitation angle.
A limitation of resonant mirror waveguides is that a variation in the wavelength of light incident at a waveguide will alter the angle of incidence required to excite resonant modes of that waveguide. The effect of a change of incident wavelength cannot be separated from the effect of a refractive index change in the sensing region, and the sensitivity of an optical sensor comprising the resonant mirror is thus limited by the extent to which variations of the wavelength of incident light can be suppressed. Lasers are used to provide the narrow wavelength band of night required for resonant mirror optical sensors. Unfortunately, lasers are susceptible to an effect known as xe2x80x98mode hoppingxe2x80x99 wherein the laser wavelength jumps between different values which satisfy the resonance, criteria of the laser structure. The wavelength produced by a laser will also vary with temperature due to variation of the dimensions of that laser. Known resonant mirror optical sensors attempts to minimise the wavelength variations in the output of a laser by providing a wavelength stabilisation mechanism. However, this mechanism is both complex and expensive.
Optical sensors comprising other optical waveguides structures may also be susceptible to wavelength changes.
It is an object of the present invention to provide a waveguide structure which overcomes or mitigates the above disadvantage.
According to an eighth aspect of the invention there is provided an optical sensor comprising a waveguide defined by a plurality of layers including a sensing layer comprising a sensing medium adapted for performing chemical or biological reactions which will result in a change of an optical property of the sensing layer, the layers being capable of supporting at least one optical mode, wherein at least a first component of a supported mode extends into the sensing layer to a substantial extent such that the first component is affected by changes in optical properties of the sensing layer, and at least a second component of a supported mode does not extend into the sensing layer to a substantial extent such that the second component is not substantially affected by changes in optical properties of the sensing layer, the sensor further comprising means for detecting variations in signals representative of the first and second components, and means for comparing the detected signals to identify variations which substantially affect only the first component.
The optical sensor is advantageous because the second component will be substantially unaffected by the optical properties of the layer of sensing medium, and may be used as a reference component. The first component will be affected substantially by the optical properties of the sensing layer, and may be used to measure said optical properties. An unwanted experimental variation, for example a change of wavelength of light coupled to the waveguide, since it will affect both components equally, may be removed from a measurement of the optical properties of the medium by comparison of the measurement and reference components.
Suitably, the layers are capable of supporting two modes a first of which is the first component and a second of which is the second component.
Preferably, the two modes are centred on different layers of the waveguide.
The two modes may be resonant mirror modes. Alternatively, the two modes may be anti-resonant reflecting optical waveguide (ARROW) modes, resonant optical waveguide (ROW) modes or light condenser modes. Other different forms of modes may be supported.
The optical sensor is advantageous for measurements utilising modes other than resonant mirror modes for the same reasons given above in relation to resonant mirror modes.
An optical sensor, according to the invention, which is designed to support resonant mirror modes may have a sensing layer of semi-infinite thickness, or may have a sensing layer of finite thickness. In contrast to this, an optical sensor which is designed to support ARROW modes or ROW modes must have a sensing layer of finite thickness, and cannot have a semi-infinite sensing layer.
The layers may be capable of supporting a single mode, a first portion of the single mode defining the first component which extends into the sensing layer, and a second portion of the single mode defining the second component which does not extend into the sensing layer.
According to a ninth aspect of the invention there is provided a method of optical sensing comprising exciting at least one optical mode in a waveguide structure defined by a plurality of layers including a sensing layer comprising a sensing medium adapted for performing chemical or biological reactions which will result in a change of an optical property of the sensing layer, wherein at least a first component of a supported mode is excited so as to extend into the sensing layer to a substantial extent such that the first component is affected by changes in optical properties of the sensing layer, and at least a second component of a supported mode is excited so as not to extend into the sensing layer to a substantial extent such that the second component is not substantially affected by changes in optical properties of the sensing layer, the method further comprising detecting variations in signals representative of the first and second components, and comparing the detected signals to identify variations which substantially affect only the first component.
Preferably, two modes are be supported by the layers, a first of which is the first component and a second of which is the second component. The two modes may be centred on different layers of the waveguide.
The two modes may be resonant mirror modes, or anti-resonant reflecting optical waveguide modes
A single mode may be supported, a first portion of the single mode defining the first component which extends into the sensing layer, and a second portion of the single mode defining the second component which does not extend into the sensing layer.

The University of Manchester Institute of Science and Technology


A stator 3 of a motor 1 is pivotally supported on a stationary system 5 by an elastic member 28, 11a, 42 provided along the circumferential direction of the stator 3, and a detector 11 for detecting a rotational force of the stator 3 is provided to execute the control of stopping, accelerating, decelerating or reversing the operation of the motor 1 based on a detection signal from the detector 11. When the motor load is increased, transmission of torque from the action system 3 to the reaction system 4 of the motor 1 is cut off, and consequently the stator 3 itself of the motor 1 pivots with respect to the stationary system 5 as a reaction. In this stage, the detector 11 detects the rotational force of the stator 3 to stop, accelerate, decelerate, or reverse the operation of the motor 1.

Conventionally, there has been known one in which, when a load system driven by a motor has been operated by a specified target amount, the drive system is automatically stopped. For example, in the case of a power window of an automobile, its motor is driven with a switch operation by the crew to move the window glass downward or upward, and upon achieving full open or full closure, a limit switch or a pressure-sensitive sensor operates to automatically stop the motor. Also, in the case of an elevator, an automatic door, a shutter or the like, it is normal to stop its drive system by position control with a limit switch or the like as described above.
In the aforementioned control device for motor driving system, the drive system stops at the point of time when the load system reaches a specified target position. Therefore, the drive system does not stop even if any error occurs until it reaches the target position. For the above reasons, a variety of irreparable troubles occur sometimes. For example, in the case of the aforementioned power window, there has been the danger that a human hand or neck may be caught in the opening or closing window glass to get injured.
Thus, the prior art apparatus detects the achievement of its purpose of moving the load system by a specified amount by means of a limit switch or a pressure-sensitive sensor and feeds this back to the motor to stop it. Therefore, the system has been unable to cope with the aforementioned error occurring in the course of achieving the purpose. Accordingly, there has been taken the measure of providing a torque limiter or the like between the motor and the load or detecting the error by reading a change of current or phase of a motor power source. However, they are easily influenced by the fluctuation of the power source or temperature, and therefore, no correct control can be expected.
A position detecting means of the limit switch or the pressure-sensitive sensor requires a stationary fixed member in order to fix the detection means. For example, in the case of the power window, the limit switch and the pressure-sensitive sensor are mounted to the window frame. However, in an automobile having no window frame, it is difficult to provide a position detecting means such as the limit switch or the pressure-sensitive sensor. In such a case, it has been executed to drive the motor by means of an inverter and stop the motor by detecting a torque increase as a consequence of the change of its input current or to stop the motor by detecting a torque increase as a consequence of the distortion of an output shaft of the motor. However, such an apparatus generally adopts the method of measuring the change of an optical signal from a stationary system having the power source in order to measure the distortion of the rotating shaft, or the method of measuring the change of a resistance value of a strain gauge by means of a slip ring. However, either method has an unstable factor and still contains a problem in achieving correct control.
Representative motors that have been conventionally used are the direct current motor, the synchronous motor and the induction motor. The direct current motor requires maintenance since it has a mechanical commutator, and it has the disadvantages of: its voltage being not increasable; a sharp change of current being unable to be followed; its capacity being limited; and sparks being generated. In view of the above, the synchronous motor which has no commutator and of which current is controlled based on a position detection signal of its rotor has been put into practical use. However, it requires a slip ring or a rotary transformer in order to supply an excitation power to the rotor in the case of a large capacity. In contrast to this, the induction motor has a simple structure and solidity and is inexpensive. In order to freely control the induction motor similarly to the direct current motor, a vector control has been put into practice. However, complicated calculation is required for the vector control, and a stable power source is necessary. In such a conventional motor, there have been the control factors of current, voltage, frequency, angle of rotation and rotational frequency. These control factors exert influence on the fluctuation of the power source and the change of the rotational frequency, and this causes a problem that high-accuracy control cannot be executed.


A method and device for finishing cellophane-wrapped packets, whereby a succession of stacks, each defined by two superimposed packets having respective heat-shrink overwrappings, are fed successively by a conveyor wheel along a circular track extending through an unloading station, prior to reaching which the packets in each stack are parted in an axial direction with respect to the conveyor wheel, and are then fed, in a radial direction with respect to the conveyor wheel, along respective superimposed paths separated by a heating plate.

In the tobacco industry, cellophaning machines are used, which are capable of forming the packets into stacks, each defined by a first and a second packet, with the second packet superimposed on the first, and with a major lateral surface of the second packet contacting a corresponding major lateral surface of the first packet. The stacks of packets are normally fed successively in a given direction along a track extending in a plane parallel to said major lateral surfaces, and through an unloading station where the stacks are unloaded onto an unloading conveyor and fed to an input of a cartoning machine.
The packets coming off cellophaning machines are normally subjected to a finish operation, in which the packets are heated to heat-shrink the overwrappings. For this to be done properly, without wrinkling the overwrappings, both the major lateral surfaces of each cellophane-wrapped packet must be heated, which is relatively easy to do on cellophaning machines on which the packets are conveyed one by one. The same does not apply, however, on cellophaning machines of the type described above, on which the packets are conveyed stacked in pairs, on account of the mutually contacting major lateral surfaces of the packets in each stack not being accessible directly.
U.S. Pat. No. 6,511,405B1 discloses an apparatus for producing cigarette packs of the hinge-lid-box type; in order to improve the outer appearance of the cigarette packs, once an outer wrapper has been provided and sealed the cigarette packs are conveyed through a shrinking station and subjected to the action of heat in the region of the large-surface-area pack sides, in particular in the region of upwardly directed front sides. For this purpose, heating plates are positioned in the region of the shrinking station and transmit heat to the upwardly directed surfaces of the cigarette packs.
U.S. Pat. No. 5,462,401A1 discloses a method of separating two superimposed rows of cigarette packets originally in direct contact with each other, whereby the two superimposed rows are fed into the input station of a separating device in a first direction parallel to the longitudinal axis of the rows; and are fed in a second direction, perpendicular to the first direction, to a separating station where they are separated by raising the top row and subsequently inserting, between the separated rows, a separating plate which is maintained between the rows as these are removed from the separating station in a third direction parallel to the first.

Method and device for finishing cellophane-wrapped packets


A gate valve comprises a valve body (1) and a gate displaceably arranged inside said valve body transverse to the flow direction, said gate being provided on each side with a guide groove (14) guided by means of a mating guide rail formed on each side of the valve body (1). The gate (13) comprises a gate core (16) coated with a polymeric material, preferably an elastomer, which in the sealing surface areas (17, 18) of the gate (13) sealingly abuts the corresponding seat surfaces (19, 20) of the valve body (1) in the closed position of the gate. At least the guide grooves (14, 44) are coated with a harder and more wear-resisting polymeric material than the remaining portion of the gate, and the two coatings are moulded such that a molecular interbinding exists between said coatings in the transition areas therebetween.

Gate valves of the above type are known which comprise a gate coated on the outside with rubber except for the guide areas. The gate is often made of cast iron with the result that corrosion problems may arise. As a consequence thereof gates entirely coated with rubber are commonly used today. However, a disadvantage of coating the guide areas with soft rubber is an increased friction and wearing off of said guide areas in some situations, such as when the valve is used for extremely high pressures. The increased friction causes in turn an increase in the stem force for opening and closing the valve.
U.S. Pat. No. 4,532,957 discloses furthermore a gate valve with a gate comprising a gate core. On each side the gate core comprises a groove wherein a plastic insert of a harder material is placed. The plastic insert forms a guide groove for mating guide rails inside the valve body. The entire outer surface of the valve gate except for the guide grooves is coated with a softer rubber material.
The manufacture of such a gate involves the steps of first manufacturing the inserts in a separate mould followed by placing the inserts in the grooves inside the gate core, said gate core subsequently being coated with rubber in a second mould.
European printed accepted specification No. 01 46 112 discloses furthermore a valve gate coated on the entire outer surface with a softer rubber-elastic material and provided with a U-shaped harder plastic insert on each side. The plastic insert forms a guide groove for guide rails in the body and is embedded in the rubber-elastic material, i.e. it is encapsulated by said material except for in the guide groove. Also the manufacture of such a gate involves the steps of manufacturing the inserts in a separate mould followed by a placing thereof together with the gate core in a second mould so as to provide the rubber coating.


This invention relates to paperboard containers. Such structures of this type, generally, allow for the container to be formed into a self-locking, pail-like container for holding food stuffs.

1. Field of the Invention
This invention relates to paperboard containers. Such structures of this type, generally, allow for the container to be formed into a self-locking, pail-like container for holding food stuffs.
2. Description of the Related Art
It is known, in the food industry, to employ a paperboard pail which is capable of being self-locking. Exemplary of such prior art is commonly found in the Chinese-food take-out industry. For example, Chinese-food take-out orders are boxed in paperboard pails having a wire handle. Commercial products of this type have been sold by the Fold-Pak Corporation since approximately 1977. While these prior, paperboard pails are capable of containing food, these pails cannot be microwaved if the food needs to be reheated due to the presence of the wire handle. Therefore, a more advantageous container, then, would be presented if the container could be microwaved.
Also, if a food package were to employ the pail container having the wire in a mass production facility, the wire would dramatically slow down the filling lines. Typically, a mass production food filling line is run so that 60 containers per minute are folded, filled and sealed. Clearly, the added production step of attaching the wire handle would adversely affect the speed of the filling lines. Therefore, a further advantageous container, then, would be one which could be easily converted into a container.
In order to avoid the use of the metallic wire, trays were developed that sealed each of the gussets to the side walls. Exemplary of such prior art is U.S. Pat. No. 5,411,204 ('204) to K. F. DeMay, entitled "Reclosable Food Tray and Tray Blank". While the tray of the '204 patent eliminates the use of the metal wire and thus can be put in a microwave oven, the tray also employs the use of adhesives in order to seal the gussets to the side walls. While the adhesives allow for the gussets to be sealed to the side walls, the adhesive may contaminate the food product contained within the tray particularly during heating of the tray and the food product. For example, if a pinhole develops in the tray and the adhesive migrates to the pinhole and into the food stuff, the food may become contaminated or develop an off-taste and/or odor. Also, the use of the adhesive adds to the cost of manufacturing the tray and adds another step in the production of the tray. Finally, upon heating, the adhesive may break down, melt and allow the gussets to become dislodged from the sidewall panels. Therefore, a still further advantageous container, then, would be presented if the use of the adhesives could be eliminated.
It is apparent from the above that there exists a need in the art for a paperboard, pail-like container which is self-locking and easily converted, and is capable of being put in the microwave oven, but which at the same time avoids the use of adhesives. It is the purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.

Method for producing a self-locking, paperboard pail-like container and product thereof


A method of at least one of programming and verifying a threshold voltage of a nonvolatile memory cell. The memory cell includes a control gate, a floating gate, a drain, a source, and a channel region between the drain and the source. The method is a voltage-type programming compared to a current type programming. A first voltage, which varies in correspondence to each threshold level programming, is applied to the control gate, and second and third voltages are applied to the drain and the source, respectively, so that the channel region is turned off at an initial stage and charge carriers for the programming are transferred from the floating gate to the drain. A conductivity of the channel region is monitored during each threshold level programming. The application of at least one voltage among the first voltage, second voltage and third voltage is cut-off to stop the programming when the monitored conductivity reaches a reference value which may be constant for every threshold level to be programmed and/or verified.

1. Field of the Invention
The present invention relates to a method of programming and/or verifying a nonvolatile memory, and particularly to a method of programming and/or verifying a threshold voltage of a nonvolatile memory.
2. Background of the Related Art
The packing density of a conventional nonvolatile memory corresponds in a one to one fashion to the number of memory cells. When nonvolatile semiconductor memory devices such as EEPROMs and flash EEPROMs are used as mass storage media, it is difficult to overcome the high cost-per-bit of the memories. To solve such a problem, a multibit cell stores data of over two bits in one memory cell to enhance the density of data on the same chip area without increasing the size of the memory cell. To achieve the storage of over two bits, more than two threshold voltage levels can be programmed on respective memory cells.
For example, in order to store data of two bits for every cell, the respective cells must be programmed in 2.sup.2 (four) threshold voltage levels. The four threshold voltage levels correspond to logic states 00, 01, 10, and 11, respectively. During the programming of the multiple levels, a problem arises due to a statistical distribution of the respective threshold voltage levels.
A typical distribution value is about 0.5 V. By precisely adjusting the respective threshold voltage levels, the voltage distribution can be reduced so that more voltage levels can be programmed, which increase the number of bits per cell. To adjust the threshold voltage levels in a conventional method, repeated programming and verification are performed. For programming, a series of voltage pulses are applied to the cells to adjust the threshold voltage levels. To verify whether a cell has reached an intended threshold voltage level, a read operation is performed between the respective programming voltage pulses. Programming is concluded when the verified threshold voltage level reaches the intended threshold voltage level.
In the conventional method of repeated programming and verification, there is difficulty in reducing the error distribution of the threshold voltage level due to the limited pulse width of a program voltage. Further, the algorithm of repeated programming and verification is implemented with additional circuits, increasing the area of peripheral circuits on the chip. The repetitive method also prolongs the programming time. To solve such problems, R. Cernea of SunDisk Co., Ltd. suggested a method of simultaneous programming and verification in U.S. Pat. No. 5,422,842.
FIG. 1A illustrates the symbol and circuit diagram of the electrically writable nonvolatile memory. The nonvolatile memory cell includes a control gate 1, a floating gate 2, a source 3, a channel area 4, and a drain 5. When voltages sufficient to cause programming are applied to control gate 1 and drain 5, a current flows between drain 5 and source 3, and electrons are injected into the floating gate 2. This current is compared to a reference current, which varies for each threshold voltage level to be programmed. When the current reaches a value equal to or smaller than the reference current, a programming completion signal is produced. The auto verification of a programmed condition at the same time as programming may compensate for the disadvantage of the repetitive program verification.
However, as disclosed in U.S. Pat. No. 5,043,940, the reference current varies for each of the threshold voltage levels to be programmed during the multi-level programming method. As shown in FIG. 1B, the relationship between the reference currents and the cell threshold voltages is neither explicit nor linear. Therefore, a current controlled type programming method like that in the aforementioned prior art has a disadvantage that a direct and effective multi-level control cannot be easily implemented.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.

Method of programming and/or verifying a threshold voltage level of a nonvolatile memory cell


An invertor controlled D.C. arc welder of consumable electrode type which is arranged to rectify an a.c. power from a commercial power supply, convert it into a high frequency a.c. power by an invertor, rectify it again to obtain a d.c. power output for welding and stabilize the output voltage by feedback control of the invertor based upon the output voltage and provided with means for discriminating shorting and arcing periods of its welding load from the output voltage and additionally controlling the invertor based upon a resultant discrimination signal to raise the output voltage during the early time of the arcing period, thereby preventing defective welding due to insufficient output current. This invention is especially, effective for supplementing such insufficient output current as an aftereffect of insufficient output power during the shortening period in such welder which is provided with means for reducing the output voltage during the shortening period to prevent generation of undesirable spattering.

This invention relates to a consumable electrode type d.c. arc welder and, especially, to an invertor controlled d.c. arc welder of consumable electrode type.
The invertor controlled d.c. arc welder is arranged to rectify an a.c. power from a commercial power supply by an input rectifier, convert its d.c. output into a high frequency a.c. power by an invertor composed of semiconductor switching elements, suitably reduce its voltage by an output transformer and again rectify it to obtain a d.c. power for welding. The welder of this type has such an advantage in that the device can be made small in size and weight since it needs no input transformer of large weight and the output transformer can be made small by increasing the output frequency of the invertor and, moreover, its output voltage can be effectively stabilized by controlling switching operation of the invertor using a difference between the output voltage and a predetermined reference voltage as its control voltage.
While d.c. arc welding of consumable electrode type, such as CO.sub.2 welding, MAG welding and MIG welding, is effected by supplying a stabilized d.c. power as above-mentioned from a welder to a welding load formed of a continuously fed welding electrode rod and a base material to be welded, separating the electrode rod shorted with the base material from the base material to form an arc therebetween and, thereafter, repeating shorting and arcing in similar fashion, undesirable spattering may take place if a current supplied to the welding load becomes excessive at the time of shorting. In order to avoid such spattering, it has been a general practice to provide a large d.c. reactor in the output side of the welder to prevent sudden increase of the load current. However, it has been a bar to reduction of the size and weight of the welder.
The inventors proposed means for preventing such undesirable spattering in the prior Japanese patent application No. H3-353356 (and its corresponding U.S. application Ser. No. 07/991,436, filed Dec. 16, 1992 now U.S. Pat. No. 5,272,314. More particularly, the shorting period Ts is detected from the output voltage V of the welder, which varies as shown in FIG. 1(a) and the above-mentioned reference voltage Sr is reduced by a predetermined value Sn during this period as shown in FIG. 1(b). Then, the above-mentioned invertor control voltage rises to reduce the output voltage during this period, thereby reducing the output current as shown in FIG. 1(c) to suppress spattering. However, it has been found that recovery of the output current is delayed at the early time of the arcing period as an aftereffect of reduction of the output current during the shorting period and less heat is supplied to the welding load. Thus, as shown in FIG. 2, a welded portion A rises abruptly from a base material B and, therefore, the welded region is narrowed to produce an insufficient weld having reduced mechanical strength.
Accordingly, an object of this invention is to provide an improved consumable electrode type d.c. arc welder which produces no defective weld as above-mentioned.

Consumable electrode type D.C. arc welder

Sansha Electric Manufacturing Company, Ltd.


A steering knuckle assembly receives a distal end of a steer axle beam which is generally symmetrical about a center line and has a pin bore therethrough. This knuckle assembly includes a steering knuckle which pivotally cooperates with the axle beam distal end. The steering knuckle includes a pair of yokes where each has a yoke bore longitudinally therethrough coaxially aligned with each other and with the pin bore. Each yoke also includes a yoke outer surface, and a yoke face surface which cooperates with a corresponding axle beam distal end and has an aperture formed therein. The knuckle assembly also includes a kingpin which has opposed ends and is received by the pin and yoke bores. Also included is a pair of yoke seals, each received by the yoke face aperture which includes an annular housing and an annular rubber portion. The rubber portion has at least one lip which operatively contacts the kingpin to provide a seal therewith. Further included is a pair of flexible bladder seals, whereby with each adjacent kingpin end defines a grease receptacle to retain grease and to provide lubrication between the kingpin and the steering knuckle during articulation.

The steering knuckle assembly (wheel spindle assembly) of a motor vehicle includes a steering knuckle having a kingpin joint which receives an end of the steer axle. A kingpin (spindle bolt) is then inserted through bores in the kingpin joint and a bore coaxially aligned in the steer axle end, thereby pivotally securing the axle to the steering knuckle. The kingpin is a pivot axis around which the steering knuckle may move with respect to the axle. Such a design is common in motor trucks of the light to heavy-duty class.
In order for the steering knuckle to pivot and rotate, lubrication is provided in the knuckle joint bores. However, possible contamination may enter the joint, among other places, where the axle beam cooperates with the knuckle. While seals are presently used, they are not able to effectively keep contamination, water, and other foreign matter out of the bearing joint, while ensuring that the joint remains properly lubricated. This often leads to relubrication of the joints at frequent intervals, resulting in greater costs and increased labor associated with maintaining the steering assembly. Also, the potential contamination of the knuckle joint may reduce the life of the kingpin, associated bearing surfaces and other kingpin joint components, which may further lead to premature wear and possible replacement of the kingpin joints.
Moreover, the associated steer axle beam deflects under load, producing a pressure differential in the kingpin joint bearing areas. This pressure differential tends to pull contamination into the kingpin joint and bearings, thus reducing the life of the bearings and other kingpin joint components and again, resulting in frequent relubrication or potential replacement of parts due to wear and insufficient lubrication.
Various references have attempted to provide lubrication to a steering knuckle. For example, U.S. Pat. No. 4,043,567 issued to Kaiser discloses a steering axle assembly having a system for ensuring that lubricant has passed completely to the outer ends of the kingpin. An end plate having a check valve is provided in this reference, whereby the check valve allows grease to pass outwardly when there is sufficient lubrication in the kingpin receiving bores. This reference further discloses a disc-type plug which is flattened into position on the lower end of the lower yoke to prevent the flow of lubricant therefrom. However, this design does not prevent contamination from being drawn into the knuckle.
Further, U.S. Pat. No. 3,659,869 issued to Hase et al. discloses an axle spindle bearing assembly which includes a lower and upper bearing connected to each other by a bore system provided in the axle spindle bolt. A reservoir space connected to the bore system is arranged in the axle spindle bolt within the area of the upper bearing which is in communication with the section of the bore system leading to the lower bearing, for example, by way of a return checking device. However, this arrangement is costly in terms of tooling, manufacturing and piece price.
Consequently, the need has developed for an improved kingpin joint of a steering knuckle assembly which provides additional protection against the introduction of contamination and other foreign matter and allows for better long-term grease retention and lubrication of the joint. The kingpin joint should also be provided with a dedicated seal for when the steer axle and associated components deflect under service loads.

Steering knuckle assembly with lubrication system


A method and apparatus samples (902) a currently received symbol to form sampled values corresponding to sampling times, and evaluates (904) the currently received symbol to determine (906) its value. The method and apparatus recalls (908) a last previously received symbol and selects (916), from a plurality of thresholds (302), a threshold based upon the currently received symbol and the last previously received symbol. The threshold is known to be crossed consistently midway in time between the centers of two adjacent nominal symbols determined by the currently received symbol and the last previously received symbol. The sampled values are compared (920) to locate two adjacent samples, one having a first sampled value greater than the threshold and one having a second sampled value less than or equal to the threshold. A timing phase error is then computed (922, 924) from the first and second sampled values.

A data communications receiver requires a symbol synchronizer for adjusting the sampling instant at which symbol decisions are made. In a radio data communication receiver, the symbol synchronizer must be resistant to noise and simulcast delay distortion, while, at the same time, it must be capable of tracking out large timing drifts associated with crystal oscillator error over long data frames. In general, there is no definitive "optimum" clock recovery technique, as the best choice of symbol synchronizer is a strong function of the pulse shaping that is used in the end-to-end system and the number of digital signal levels in the case of M-ary signaling.
In simulcast paging systems, for example, pulse shaping is usually kept "loose" in the frequency domain by using, for example, Bessel filtering on both the transmit (pre-modulation filter) and receive (post-detection filter) ends, so that the demodulated eye exhibits a wide eye opening. Using such pulse shaping, it can be shown that, for a 2-level case, the zero-crossings provide ideal timing information, making the traditional zero-crossing PLL used in prior art receivers appropriate for symbol synchronization. The general M-ary case (with M>2), however, exhibits jitter in its zero-crossings, making the zero-crossing PLL used in many prior art 4-level receivers, for example, sub-optimum.
Other prior art techniques have reduced the zero-crossing jitter by allowing timing information to be obtained for only "usable" symbol transitions, i.e., those transitions that produce no zero-crossing jitter. Such techniques can allow excessive timing drift and increased bit error rate when the received data includes too many contiguous non-usable symbol transitions.
Thus, what is needed is a method and apparatus for facilitating symbol timing acquisition in a data communication receiver. Preferably, the method and apparatus will overcome the above described prior art deficiencies for the general M-ary case and will provide a new, jitter-free timing phase error measurement.

Method and apparatus for facilitating symbol timing acquisition in a data communication receiver


A child motion apparatus includes an upright column defining a vertical axis, a carriage assembled with the upright column and including a swing shaft portion operable to rotate about a pivot axis, a swing arm affixed with the swing shaft portion, a first motor drive unit assembled with the carriage and having an output shaft, a drive transmission respectively connected with the output shaft and the swing shaft portion, a second motor drive unit assembled with the upright column, and an actuating mechanism respectively connected with the second motor drive unit and the carriage. The drive transmission can transfer an output drive provided by the first motor drive unit at the output shaft to the swing shaft portion to impart rotation to the driven swing arm. The actuating mechanism is drivable by the second motor drive unit to vertically move the carriage relative to the upright column.

1. Field of the Invention
The present inventions relate to child motion apparatuses.
2. Description of the Related Art
Swing apparatuses can be used by parents to help calming or entertaining a child. A child swing apparatus typically travels at a natural frequency in a pendulum motion. The drive system for the swing apparatus is generally located at the pivot point of the pendulum at a high location in the frame structure of the swing apparatus, and the pivot point is generally fixed relative to the swing frame. While the conventional pendulum motion requires driving at the point of highest torque, the system can store the potential energy from one half cycle to another, requiring only a soft push or pull to maintain or increase the amplitude.
However, a few drawbacks may exist in the conventional swing apparatuses. In particular, the swinging motion and frequency are generally locked as a function of the length of the swing arm. If a slower frequency is needed along a same motion path, it may be extremely difficult to exert a driving torque for overcoming the gravitational force acting in the pendulum motion. Accordingly, the drive systems applied in most of the currently available swing apparatuses cannot allow truly adjustable swinging frequency and have a limited range of movement paths.
Therefore, there is a need for an improved structure that can address at least the aforementioned issues.


A pizza box storage and dispensing assembly is disclosed. The assembly includes a pair of telescoping enclosures of generally rectangular cross-sectional outlines sized to snugly receive stacked pizza boxes. The enclosures have rear sections, side walls or sections, and front sections with the front section of the lower enclosure being provided with a dispensing opening at its lower end dimensioned to permit grasping and withdrawal of a single pizza box therethrough. A plate with parallel risers on its sides is fixed to lower sections of the sidewalls of the lower enclosure and extends rearwardly and upwardly from the lower end of the dispensing opening to a lower portion of the rear section of the lower enclosure. Upper and lower restraining paddles are disposed in both sidewalls of the lower enclosure with the lower paddles connected with springs urging them inwardly and the upper paddles interconnected with rods with a lower rods arranged adjacent the plate to be engaged by the lowermost pizza box to transmit a force through the rods to urge the paddle inwardly from the sidewall to thereby restrain downward movement of the pizza boxes at and above the upper paddle. Withdrawal of the lowermost pizza box releases the force allowing the paddle to return against the sidewall and allowing the pizza boxes to slide downwardly while urging the lower paddles inwardly against the force of the springs.

This invention relates to a pizza box storage and dispensing assembly.
Restaurants which prepare pizzas ordinarily provide for take-out or delivery of the pizzas to consumers. Cartons or boxes of well-known configuration are used for the take-out pizzas. Boxes ready to be filled with prepared pizzas are stacked at some location in the kitchen of the restaurant. A common place to stack the pizza boxes is on shelving above a table where the pizzas are prepared or brought to when they are done baking. Most often the stack of pizza boxes extends to a height well above the maximum reach of the kitchen personnel. A pizza box to be filled is of necessity drawn out from the lower or middle section of the stack. The weight of the pizza boxes above the one sought to be removed for use makes removal difficult sometimes causing the upper boxes to be toppled over as a lower box is removed.
This invention overcomes the problems inherent in storing pizza boxes for anticipated use by providing a pizza box storage and dispensing assembly which allows for orderly storage of pizza boxes and easy retrieval of a single pizza box for filling with a pizza. Pizza boxes are easily placed in the assembly which may be telescopic in form to vary the storage space for the boxes. The lowermost pizza box within the assembly is exposed to be readily removed when needed. Upon removal of the lowermost pizza box the upper boxes shift downwardly positioning a new box for removal. The stored pizza boxes are in a stable stacked arrangement and will not be toppled during removal of the lowermost box. The advantage of ease of removal of the lowermost box and stable storage are provided by a structure which is simple in design and thus economical to produce.

Pizza box storage and dispensing assembly


The present invention is directed toward a lighting device of motor vehicle with an arrangement of at least two light conductors. Each conductor includes one coupling arm having a first cross section, a light conductor area with a second cross section, and a transition area located between the coupling arm and the light conductor area. The coupling arms include a respective first contact surface, and the transition areas of the light conductors include a respective second contact surface. The contact surfaces are formed in such a way that the coupling arm of the one light conductor inserts into the transition area of the respective other light conductor. Each one of the two coupling arms include deflectors on a rear side of the coupling arm, which deflect towards the front side, within a section of the transition area where each respective coupling arm fits into the other light conductor.

1. Field of Invention
The present invention relates to lighting devices for motor vehicles and, more specifically, to a lighting device with a light conductor arrangement.
2. Description of Related Art
Lighting devices for motor vehicles that have a light conductor arrangement, as known in the art, typically include a front side, an opposing rear side that has light deflectors, and side areas connecting the front and the rear side. These sides are arranged in such a way that light, which experiences a total internal reflection on the side areas and on the front side, is directed into a longitudinal direction of the light conductor arrangement, so as to allow light reflected at the light deflectors to emit through the front side. Such a lighting device in a motor vehicle is known from Published German Application DE 102005029363A1, wherein the light conductor is designed as a light ring. The diameter of the light ring is a multiple of the size of the cross section of the light conductor, and the longitudinal expansion of the light ring is proportionally larger than its lateral extension. Thus, the light ring can be described as an elongated light conductor. Prisms serve as deflectors and direct the light onto the front side at such a steep angle that the light does not experience a total internal reflection and will be emitted out of the ring. The ring is not realized as an infinite loop, but has two ends which cross approximately at right angles and interpenetrate each other. The coupling of light is achieved via the two respective end faces, which is disadvantageous in that a closed and illuminated contour cannot be accomplished with this structure.
It is also possible to use a structurally closed ring, where light is coupled radially and then directed into the desired tangential circumferential direction by a deflector arranged inside the ring. This can be accomplished, for example, with minor elements set in a 45° angle with regards to the radial direction. However, this is disadvantageous in that the deflection which occurs at the coupling of the light is clearly perceivable. Thus, this structure also does not accomplish a closed ring-shaped illuminated appearance.
From Published German Utility DE 202 068 29 U1, a light having a light guide body made in the basic shape of a glass pane is known. A deflector is arranged in the center of a glass pane area, which deflects the light from a light source positioned centrally in front of a center point of the glass pane area, and which emits light into the direction of the glass pane area, radially towards the outside. Along the outer periphery, a further circumferential deflector is integrated into the glass pane, which lets the incident light emit there via a glass pane area. The disadvantage of this light is that the inner area of the glass pane has to be reserved for the light paths of the light that is radially deflected towards the outside. As such, no other components of other light functions can be arranged in this inner area. For example, an arrangement in which day time running light is aligned round about a head light cannot be accomplished.
In view of the above, there remains a need in the art for a lighting device which omits the mentioned disadvantages or which at least minimizes them. Specifically, there is a need for the realization of a ring-shaped light, in which the inner area has space for components of other light functions and which provides a homogeneous brightly illuminated appearance alongside a closed contour.

Lighting device in a motor vehicle with a light conductor arrangement


Presented is an automated policy-provisioning method for a computing system having a service-oriented architecture. The system comprises at least one managed service and at least one policy enforcement point operable to enforce a runtime policy for the service. The method comprises: receiving in machine-readable form at least one semantic rule defining a condition imposed by a business policy; receiving machine-readable data describing a runtime policy enforcement capability of the at least one policy enforcement point; determining based on the at least one rule and the capability whether the at least one policy enforcement point can meet the condition; based on the determination, deriving a runtime policy suitable for enforcing the condition; and communicating the runtime policy to the at least one policy enforcement point.

Service-oriented architecture (SOA) is a design paradigm for computing systems. It is based around an abstract model in which computing resources are considered in terms of needs and capabilities. In such a model, a service is an entity which is made available to a service-client, to fulfill one or more needs of the client. A core principle of SOA is that services are loosely coupled: that is, different services can be provided by different providers, potentially distributed at different physical locations or points in a computer network. Thus, services are not provided in fixed, monolithic groupings (as is often the case with legacy software applications) but, instead, a service-client can draw together the particular group of services that best fits its needs. The SOA model can be particularly beneficial when it is desired to integrate diverse computing functions—for example, several different computing functions used in a business. In this case, the SOA paradigm can lead to a reduction in redundancy, and resulting decreased commissioning and maintenance costs—for example, because common tasks such as log-in or authentication are implemented just once and then shared as a service (or set of services), instead of being provided independently in several separate software applications.
The potential improvements in efficiency and flexibility offered by SOA are great. However, the openness and interoperability demanded by such a software-architecture places additional demands on the designers of computer systems. It is desirable that an organization retains adequate control of software components made available as services, despite their open availability on a network, for example. This leads to a concept of a "managed service", which is made available for service-clients to use, but is managed according to a runtime policy. This runtime policy ensures that the overall business policy of an organization is obeyed. It is the practical implementation of the principles contained in the business policy.
Responsibility for enforcing runtime policies falls on Policy-Enforcement Points (PEP). These are points in the system architecture which can act as gateways to the services. Thus, a client wishing to access a service does so via a policy enforcement point, which enforces the runtime policy for that service. A contract is formed when one party to a service-oriented interaction agrees to adhere to the policies of another.

Hewlett Packard Enterprise Development LP


A metal diaphragm type valve includes a valve seat holder supported from a rotatable valve stem, a metal diaphragm and a deflection limiter. The valve seat holder has a shaft extending upwardly through central openings in the diaphragm and the deflection limiter. A diaphragm support step having an annular flat surface joining an arcuate shoulder is provided around the shaft of the valve seat holder and the inner peripheral edge of the diaphragm rests on the flat surface. The deflection limiter has a flat bottom surface facing the top surface of the diaphragm and an arcuate surface extends radially outwardly from the flat bottom surface. The deflection limiter, diaphragm and valve seat holder are welded together by a weld extending through the flat bottom portion of the deflection limiter and the inner peripheral edge of the diaphragm to the flat surface on the seat holder, the weld forming an air-tight seal between the valve chamber and the passage for the shaft. The radial dimensions of the flat surfaces are different so that bending stresses occur in different regions of the diaphragm depending on whether the valve is opened or closed.

In the manufacture of semiconductors it is frequently necessary to supply precise volumes of different fluids, say gases, to a treatment chamber, the fluids being conveyed to the treatment chamber in sequence through a fluid feed line controlled by a diaphragm valve. Typically, a first fluid is applied to the treatment chamber through the feed line after which a purge fluid is applied to the feed line to purge any traces of the first fluid. After purging, the second fluid is then applied to the chamber through the feed line.
During the purging operation it is desirable to remove as much as possible of the first fluid in the feed line and valve so that the first fluid will not contaminate the second fluid. To accomplish this, the valve interior should have no gaps, crevices or `dead air spaces` within the chamber where fluid may be caught or trapped so that it is not purged from the valve during the purging operation. As the degree of integration of semiconductors increases, there is a corresponding demand for increased fluid purity and only a very slight amount of fluid trapped in a crevice has a serious effect on the quality of the semiconductor product, and increases the frequency of defective pieces.
In metal diaphragm valves, a crevice which traps fluid and prevents complete purging is frequently found where the metal diaphragm is mounted on a seat holder which extends through the diaphragm.
FIGS. 6 and 7 illustrate a seal structure as disclosed in U.S. Pat. No. 4,750,709 for sealing the inner peripheral edge of a diaphragm in a metal diaphragm type valve to a seat holder. The end portion of the inner peripheral edge of a diaphragm 40 is welded by a weld 80 to a eat holder 78, and an inner peripheral edge portion of the diaphragm, spaced from the weld 80 by distance D, is gripped and supported between the lower surface of a presser 82 and the upper surface of the seat holder 78 at a region 94, thereby preventing a bending stress from being applied to the weld 80 at the time of operation of the diaphragm.
In FIGS. 6 and 7, reference numeral 100 is a body, 100a is a valve chamber, 100b is a valve seat, 100c is a fluid passage, 50 is a bonnet, 160 is a seat, 88 is a stem, 86 is a screw formed at the lower end of the stem and 94 is a gripping region.
The valve disclosed in U.S. Pat. No. 4,750,709, and shown in FIGS. 6 and 7 has several disadvantages. Since the diaphragm 40 is gripped at region 94 spaced by a distance D from weld zone 80, and is supported between the lower surface of the annular presser 82 and the seat holder 78 whose entire upper surface is formed to have a curvature, a deep annular gap Go is formed between the lower surface of the diaphragm and the upper surface of the seat holder. As a result, fluid is likely to be caught in the gap so that it is not easily purged during cleaning of the valve. Accordingly, in this valve the so-called replacement or purging performance of fluids is inferior.
Moreover, since a screw structure 86 is utilized to clamp the diaphragm between seat holder 78 and the presser 82, the screw tightening may be loosened over a long course of use, and in such a case the gripping and supporting of the inner peripheral edge of the diaphragm 40 may be released. As a result, up and down movement of the seat holder 78 causes a large bending stress to be applied to the weld zone 80. This may lead to the formation of cracks in the inner peripheral edge of the diaphragm.
Further, since the diaphragm 40 is gripped in the position or region 94 spaced outwardly from the weld zone 80 by the distance D, fluid does not normally flow into the gap G between the lower surface of the diaphragm 40 and the upper surface of the seat holder 78 falling within the distance D. However, repeated vertical motion during normal valve usage causes a change in the thickness of the diaphragm at the gripping portion 94 so that air-tightness of the gap G is lost and fluid enters the gap where it is caught and not easily removed. As a result, the fluid replacement or purging performance is lowered.
The valve shown in FIGS. 6 and 7 has a further disadvantage. Since the diaphragm 40 is gripped by the presser 82 and the seat holder 78 from above and below at the annular position 94, bending stress of the diaphragm is concentrated on one point of the gripping position 94 as the diaphragm moves up or down. As a result, the diaphragm cracks or is damaged in the vicinity of the gripping position as a result of metal fatigue due to repeated movements of the diaphragm over a period of time, this damage occurring earlier than in any other parts of the diaphragm. Thus, it is hard to extend the life of the diaphragm.
FIGS. 8 and 9 illustrate a metal diaphragm valve with a diaphragm seal structure as disclosed in Japanese Laid-open Patent 114265-1996. This valve includes a valve body 100, a valve chamber 100a, a valve seat 100b, fluid passages 100c, a bonnet 50, a valve seat 160, a bushing 51, a ball 52, a stem 53 and bonnet insert 54. In this arrangement a shaft 91a of a seat holder 91 is inserted through a mounting hole 93a of a diaphragm 93 and a center opening in a weld metal member 90.
The inner peripheral edge of the diaphragm 93 is disposed between an annular flat portion 90a formed on the lower surface of the weld metal member 90 and an annular flat portion 91b formed on the upper surface of the seat holder 91. The end portion of the inner peripheral edge of the diaphragm and the portions of the member 90 and the seat holder abutting the end portions of the inner peripheral edge of the diaphragm 93 are welded together at a weld zone W around the entire circumference of the inner peripheral edge of the diaphragm thereby integrally affixing the diaphragm, the seat holder and the weld metal member.
In the valve shown in FIGS. 8 and 9, bending stress is prevented from being applied to the weld zone W during operation of the diaphragm 93 because movement of the inner peripheral edge of the diaphragm immediately outward of the weld is limited or prevented by abutment of the diaphragm against the flat portion 90a of the lower surface of the weld metal member 90 and the flat portion 91b of the upper surface of the seat holder 91. This arrangement is designed to prevent the fluid being controlled from being caught in the gap between the inner peripheral edge of the diaphragm and the upper surface of the seat holder.
Since the inner peripheral edge of the diaphragm 93 lies between the annular flat portion 90a formed in the weld metal member 90 and the annular flat portion 91b formed in the seat holder 91, the gap Go formed between the lower surface of the diaphragm and the upper surface of the seat holder is smaller in depth as compared with the corresponding gap Go of the valve shown in FIGS. 6 and 7 although this difference is not obvious from the figures because of the small dimensions involved. As a result, fluid in the valve shown in FIGS. 8 and 9 is less likely to be caught in the gap Go.
Furthermore, since the inner peripheral edge of the diaphragm 93, weld metal member 90 and seat holder 91 are affixed and integrated by welding, the risk of leakage of fluid from the end portion of the inner peripheral edge of the diaphragm is much less than in the case of the valve shown in FIGS. 6 and 7 so the sealing performance is extremely high.
Also, since the inner peripheral edge of the diaphragm is confined between the flat portion 90a of the weld metal 90 and the flat portion 91b of the seat holder 91, if the screw of the shaft 91a is loosened so that the seat holder 91 slightly moves up or down, a large bending stress is not directly applied to the weld zone W of the diaphragm. Thus, cracks are less likely to be formed in the weld zone W of the diaphragm 93 as compared with the diaphragm 40 of FIG. 6.
In the valve shown in FIGS. 8 and 9, when the diaphragm 93 moves up or down, the bending stress in the diaphragm is concentrated in the region or outermost position 94 corresponding to the outward radial extent of the flat bottom surface 90a of the weld metal member 90 and the outward radial extent of the flat upper surface 91b of the seat holder 91. The flat surfaces support diaphragm 93 radially inwardly of position 94 but the diaphragm is free to bend outwardly of this position. As a result, when the diaphragm 93 is operated repeatedly, the part of the diaphragm in the vicinity of the position 94 suffers metal fatigue and cracks earlier than other parts of the diaphragm and it is hard to extend the life of the diaphragm.
In the valve shown in FIGS. 8 and 9, the spacing between the lower surface of the diaphragm 93 and the planar upper surface 91b of the seat holder 91 is extremely small, so any fluid accumulation in the gap G between these surfaces is minute. However, repeated vertical motion of the diaphragm during normal usage causes the thickness of the diaphragm to gradually decrease, and the volume of the gap G increases. This permits a greater volume of fluid to enter the small gap and the fluid replacement performance of the valve is lowered.
It should be noted that since the length dimension l (FIG. 9) of the upper flat surface portion 91b of the seat shoulder 91 is selected to be relatively large, a relatively large mass of fluid may enter the gap G and lowering of the fluid replacement performance is a more serious problem.
The valve illustrated in FIGS. 8 and 9 has a further disadvantage in that it requires a large number of parts such as ball 52, bushing 51, bonnet insert 54 and weld metal member 90. Assembly of these parts is complicated and difficult, and it requires much time and labor to complete its assembly.


A new and distinct cultivar of Hosta plant named ‘Great Escape’, characterized by its broadly spreading foliage with upright flower scapes; green and white variegated foliage; violet-colored flowers that are positioned above the foliage on strong scapes; and good garden performance.

The present invention relates to a new and distinct cultivar of Hosta, botanically known as Hosta tardiana and hereinafter referred to by the name 'Great Escape'.
The new Hosta is a naturally-occurring branch mutation of the Hosta tardiana cultivar Halcyon, not patented. The new Hosta was discovered and selected by the Inventor in a controlled environment in Barneveld, The Netherlands in 2002.
Asexual reproduction of the new Hosta by tissue culture in a controlled environment in Barneveld, The Netherlands since 2003, has shown that the unique features of this new Hosta are stable and reproduced true to type in successive generations.


A pipe cutter includes a body having two side walls and each of the side walls has an arcuate slot. A rod pivotally extends through the first end of the body and a first contacting member is rotatably connected to the second end of the body. A first link has a first end thereof pivotably connected to the body and a second end thereof having a disk blade rotatably connected thereto. The rod is pivotally connected to the first link to which a second link is pivotally connected, the other end of the second link has a second contacting member rotatably connected thereto. The second contacting member has two protrusions extending centrally and longitudinally therefrom so as to move within the two arcuate slots.

A conventional pipe cutter generally includes a body made of cast iron, two fixed two  rollers arranged to an inner side of the body and a movable blade disk movably connected to a threaded rod which can be moved by rotating a knob connected to a distal end of the threaded rod. A pipe to be cut can be clamped by the two fixed rollers and the disk blade which is moved twoard the two fixed rollers. By rotating the threaded rod, the disk blade cuts the pipe. However, the speed to move the disk blade is so slow so  that it takes a lot of time to cut the pipe. In addition, the conventional pipe cutter can be only used to cut the  pipe having the  a smaller diameter, because the distance between the two rollers is not adjustable so that a pipe having a large diameter will not be well clamped between the two rollers and the disk blade. Furthermore, the threaded rod can only be moved in a fixed direction and this limits the positions where the rollers are located. All of the three  prior pipe cutters are made in a form of a one-piece article which is made of cast iron which is heavy so that the users cannot use them conveniently. The cost for manufacturing the  conventional pipe cutters is high and therefore reduces the commercial benefit.
The present invention intends to provide an improved pipe cutter wherein one of the two rollers is fixed and the other is movable, the disk blade is movable and pivotally connected to the movable roller by two links so that the two rollers and the blade disk clamp the pipe to be cut evenly on the outside of the pipe, and the pipe cutter of the present invention may clamp pipes with different diameters.


Disclosed herein are various methods, systems, and compositions for the growth independent detection of cells such as microorganisms including bacteria. While existing cellular detection methodologies benefit from cell growth, the methods, systems, and compositions disclosed herein demonstrate embodiments that are independent of cell growth while still allowing for cell-based detection.

In the research laboratory, many studies employing cells are conducted using cultured cells that often exhibit logarithmic growth. In nature, however, cells are rarely in a logarithmic growth-rate and often are in a stationary state. This phenomenon is an important consideration in the development of clinical diagnostics for the detection of cells since clinical samples can contain cells that are not in a metabolic state that supports optimal growth. In some cases, cells can be obtained that do not grow under the assay conditions intended to detect the cells. As such, when testing for the presence of cells directly from a clinical or environmental sample, it can oftentimes be important to employ an assay that operates independent of cell growth.
Even when cells are isolated and cultured in the laboratory there can still be situations in which individual strains of isolated cells can exhibit varying growth characteristics. When such cells exhibit sub-optimal growth, this can lead to a cell not being detected by an assay that generally requires growth. Example 9 of WO 2014/145899 exemplifies this situation (See page 80, line 2-page 82, line 33, and FIG. 26B). In that assay, S. aureus cells were monitored for growth in the presence of clindamycin. The assay was intended for distinguishing a clindamycin susceptible vs. resistant phenotype making the determination based on the growth rate of the bacteria in the presence of clindamycin. In the assay, one clindamycin-resistant isolate of bacteria was misinterpreted as clindamycin-sensitive because the isolate exhibited a sub-optimal growth rate.
As such, assays that generally require a minimum amount of growth or a minimum growth rate may not detect target cells that do not exhibit the required growth characteristics during the assay.
Related patent applications include: PCT/US2014/026536, filed on Mar. 13, 2014, which is hereby incorporated by reference, in its entirety, for all purposes.


The present invention discloses a connector, which includes a male housing and a female housing. The male housing is formed of three side walls surrounding a circumference of a bottom wall and the female housing is formed of three side walls surrounding a circumference of a bottom wall. The male housing and the female housing are mateable with each other through mutual insertion. Practicing the connector of the present invention may reduce the wall thickness of the connector, making the connector thinner so as to enable use in a backlight module arrangement of relatively small space and provide module designing with more flexibility.

1. Field of the Invention
The present invention relates to the field of liquid crystal panel manufacturing, and in particular to a connector.
2. The Related Arts
As shown in FIG. 3, a schematic view of a conventional connector is shown. The conventional connector comprises a male housing 8 and a female housing 9. The male housing 8 and the female housing 9 are each formed by being surrounded by four side walls that are connected end to end. The female housing 9 is insertable into a chamber defined in the male housing 8 to effect connection between mating ports set up in the chambers defined in the housing.
Connectors of such structures, once inserted and connected, show four wall thicknesses in the height direction, making it hard to use in an arrangement of backlight module that provides a relatively small space.

Shenzhen China Star Optoelectronics Technology Co., Ltd


An intake port of an internal combustion engine 10 is provided with a fuel injection valve 22. An intake adjustment mechanism 30 for varying the valve timing of an intake valve 24 and an exhaust adjustment mechanism 32 for varying the valve timing of an exhaust valve 26 are furnished. Immediately after internal combustion engine startup, fuel atomization is facilitated by exercising control so that the valve opening timing for the intake valve 24 coincides with a retarded valve opening timing after exhaust top dead center. In such an instance, the fuel introduced into a cylinder is inhibited from adhering to the exhaust valve 26 and its neighborhood by exercising control in such a manner that the valve closing timing for the exhaust valve 26 coincides with a retarded vale closing timing, which is retarded from a normal valve closing timing.

A conventionally known device that is disclosed, for instance, by Japanese Patent Laid-Open No. 2002-242713 retards the valve opening timing of the intake valve while the internal combustion engine is cold. When the temperature of the internal combustion engine is within the range of 0 to 50° C., this device selects, for a region retarded from the exhaust top dead center, intake valve opening timing that is retarded from normal valve opening timing.
In a region where the exhaust top dead center is exceeded by a crank angle, the more retarded the intake valve opening timing, the higher the intake flow velocity. Therefore, while the internal combustion engine is cold, the above-mentioned conventional device can provide a higher intake flow velocity than in a normal state. When the intake flow velocity is high, the fuel injected into an intake port is likely to become atomized and unlikely to adhere to the intake port or intake valve.
The more atomized the fuel supplied to the internal combustion engine, the higher the combustion quality. Further, air-fuel ratio control in the internal combustion engine can be accurately exercised when the port wet amount is small. Therefore, the above-mentioned conventional device can enhance the stability of the internal combustion engine and provide increased accuracy in air-fuel ratio control at the time of an internal combustion engine cold start.
The applicant of the present invention has acknowledged that the following documents relate to the present invention including the aforementioned document:
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-242713
[Patent Document 2]
Japanese Patent Laid-Open No. 1994-323168
[Patent Document 2]
Japanese Patent Laid-Open No. 1998-252575