An example method of interfacing with a hypervisor in a computing system is described, which includes a processor having at least three hierarchical privilege levels including a third privilege level more privileged than a second privilege level, the second privilege level more privileged than a first privilege level. The method includes: identifying an input/output (I/O) space instruction, not supported by the processor, to be performed for backdoor communication between the hypervisor and guest software executing in a virtual machine (VM) managed by the hypervisor, the hypervisor executing at the third privilege level; writing one or more parameters to one or more registers of the processor that are mapped to one or more unsupported registers used by the I/O space instruction; writing a value indicative of the I/O space instruction to a designated register of the processor; executing an instruction, by the guest software executing at the first or second privilege level, which is trapped to the third privilege level.

A computing system can include an operating system (OS) executing on a hardware platform, which includes processor(s), memory, storage, input/output (IO) devices, and the like. When the OS executes directly on the hardware platform, the OS is referred to herein as a "host OS." Computer virtualization is a technique that involves encapsulating the hardware platform of the computing system into virtual hardware platforms on which virtual machine(s) execute under control of virtualization software. A virtual machine (VM) provides virtual hardware abstractions for processor, memory, storage, and the like to a guest operating system (OS) and guest application(s) that run on the guest OS. The virtualization software provides virtual hardware platforms and virtual execution environments for the virtual machine(s).
A guest OS in a VM can include support tools for communicating with the virtualization software (e.g., a hypervisor). The support tools include components that execute in kernel mode and components that execute as regular applications (e.g., user mode). These support tools provide "back door" interfaces to interact with various hypervisor components to provide a better end-user experience, as well as making the guest OS virtualization-aware. One approach to perform a call into the hypervisor from a guest OS in a VM is to use a hypervisor call instruction. However, on some central processing units (CPUs), such a hypervisor call is restricted to privileged mode (e.g., kernel mode) code, rendering it unusable by regular applications (e.g., user mode code). It is desirable to provide a technique for all guest code (e.g., kernel mode and user mode) to interface with the hypervisor.

Unified hypercall interface across processors in virtualized computing systems


A tire tread catcher consisting of canister that catches tread as they are thrown off tire(s) and a housing surrounding the tire(s) to funnel and direct tread and road debris to the canister. The canister is attached to a truck or trailer undercarriage adjacent to and right behind the tires. The canister is open towards the tire and may have a scope shaped bottom edge. The housing encloses the front and sides of the tire. The front plate of the housing can be tapered to reduce wind resistance. The side plates also reduces wind resistance and protects the tire(s) from sun exposure. The housing helps to ensure any tread thrown off the tire is directed towards the canister, where the tread and debris is captured and retained.

The present invention relates to a tire tread catcher and more particularly to an apparatus that attaches to the undercarriage of a vehicle or trailer around and behind the tire(s) to catch any tread thrown from a tire.
Retreaded tires are often used on trucks, trailers, cargo vans and other type of vehicles. The retreaded tires are typically cheaper than new tires, making them attractive to the users. One problem with retreaded tires is that they often throw the tread off the tire. The tread thrown off typically lands on the highway and creates a road hazard. The tread laying on the highway can cause damage to automobiles and other vehicles. The tread can also cause a driver to maneuver around the obstacle. This can cause traffic problems and perhaps a collision with another vehicle or an accident of some other sort.
The tire tread catcher of this invention addresses this problem. The thrown tread is captured and retained for later disposal and eliminates the hazards created by tread left behind on the highway.
Tires and the materials tires are made of are now recyclable. As such, tread left behind usually ends up being trashed. However, with the tread catcher of this design, the tread is retained for proper disposal and recycling.
Another benefit of the tread catcher of this invention is that other road hazards are also reduced. Other objects, such as rocks and other debris, are often thrown by rotating tires of vehicles. The tire tread catcher of this invention also captures and retains flying debris to reduce these types of road hazards.
Accordingly, it is an object of the present invention to provide a tire tread catcher adapted to capture and retain tread thrown from retreaded tires.
Another object of the present invention is to provide a tire tread catcher constructed to reduce or eliminate road hazards due to tread being left behind on the highway and the collection and retention of other debris that may be a road hazard.
A further object of the present invention is to provide a tire tread catcher adapted to protect the tire or tires on a vehicle from deterioration from the sun, thereby extending the life of the tires.
Still another object of the present invention is to provide a tire tread catcher that may reduce wind resistance thereby improving the performance of the vehicle.
Still a further object of the present invention is to provide a tire tread catcher adapted to funnel and direct tread thrown from the tire or tires and road debris into a canister for retention and later disposal. The tire tread catcher of this invention is characterized by a housing surrounding the tire(s) to act as a funnel to direct objects to a canister mounted behind the tire(s).
These and other objects and features of the present invention will be better understood and appreciated from the following detailed description of the main embodiment thereof, selected for purposes of illustration and shown in the accompanying drawings.


An approach for allocating bandwidth is disclosed. A request is detected from a terminal for capacity on a communication channel based on type of traffic transmitted from the terminal. A bandwidth allocation pattern designated for the terminal is retrieved, wherein the bandwidth allocation pattern is set based on a predetermined service plan associated with the terminal. Bandwidth over the communication channel is reserved for the terminal according to the bandwidth allocation pattern without feedback to the terminal. This arrangement has particular applicability to a satellite network that provides data communication services.

Communication service providers, from cable to cellular to satellite providers, are ever mindful of the performance and availability of their networks. One key aspect for ensuring high performance and high availability concerns how traffic is engineered. This challenge is even greater when the network carries a diverse range of traffic type, from low data rate non-real-time traffic to high data rate real-time traffic. Additionally, subscribers require flexibility in terms of their commitment, or lack thereof, to a predetermined amount of capacity ahead of time. Such demand has resulted in the development of on-demand bandwidth allocation techniques, whereby a station or terminal can request capacity dynamically as their load requirements change. Traditionally, these bandwidth allocation techniques are closed loop, such that a feedback mechanism is established between a granting terminal and the requesting terminals to determine the amount of desired capacity. One drawback with this approach is that network capacity is consumed as overhead, largely because of this feedback or closed loop.
Based on the foregoing, there is a clear need for improved approaches for allocating bandwidth, while minimizing overhead.

Method and apparatus for providing open loop bandwidth allocation


A folded cascode receiver amplifier with constant gain has inputs coupled to PMOS and NMOS differential transistors pairs with scaled geometries. The transconductance of both PMOS and NMOS transistors is the same whether the common mode input voltage is low or high. In a first version the transconductance of both PMOS and NMOS differential transistor pairs is reduced when the common mode input voltage is at mid-rail. Resistive means between current sources and the sources of the PMOS and NMOS transistor pairs force the current source transistors into the triode region of operation. A second version insures a constant voltage gain through control means which maintain a constant ratio of the transconductance of the output stage transistors versus the PMOS and NMOS differential transistor pairs when active.

1. Field of the Invention
The invention relates to a low voltage differential signal receiver, and more particularly to a receiver which has a constant voltage gain over a large input common mode voltage range.
2. Description of the Related Art
Because of the large common mode input range (0.2 v to 2.2 v) that a preamplifier for a Low Voltage Differential Signal (LVDS) receiver uses, the CMOS rail-to-rail input stages of the preamplifier comprise an NMOS differential pair connected in parallel with a PMOS differential pair. The NMOS input pair is able to reach the positive supply rail while the PMOS input pair is able to reach the negative supply rail. At the middle of the common mode voltage range, both the NMOS and PMOS input pairs are on, and the total transconductance gm has twice the gm of a single pair, assuming both pairs have the same gm value. Because of this, the total transconductance is not constant across the input common-mode range. This is an undesired phenomenon because it results in non-constant gain and variable unity gain bandwidth.
Below are the typical specifications of a Low Voltage Differential Signal (LVDS) receiver that the preamplifier needs to support:
LVDS Receiver Preamplifier Specifications:
Featuresfrequency 175 MHz to 945 MHzDC SpecificationsSymbolParametersConditionMinTypMaxUnitVTHDifferentialVOC = +1.2 V+100mVInput HighThresholdVTLDifferential−100mVInput LowThresholdVidInput differ-Rin = 100 ohm0.10.4Vential voltageIinInput currentVin = +2.4/0 V±10μAVcc = 3.6 VVocCommon Mode0.21.22.2VVoltage
All known prior art has attempted to solve the above mentioned problem of non-constant gm over the entire common mode input range. This is due to the application of the rail-to-rail input stage in Operational Amplifier design where large variation of gm impedes an optimal frequency compensation.
Referring now to FIG. 1, which was taken from the second reference listed below (W. Redman-White), we describe a typical circuit of the prior art. Rail-to-Rail input stages utilizing NMOS (M1, M2) and PMOS (M3, M4) differential pairs in parallel and joined by a Current Summation block, have three operating regions with respect to the Input common mode voltage range. When the common mode Input voltage is near the negative power supply (VSS), only the PMOS pair operates. For common mode Input voltages near the positive power supply (VDD), only the NMOS pair operates. For common mode Input voltages around mid-rail, both differential pairs operate and in this region, the transconductance of the input stage is twice as big as in the regions where only one pair (PMOS or NMOS) is on. The basic principle behind this is to vary the effective tail current in the active differential pair so that its gm doubles when the other is inactive. A simple way to achieve this is to use a transistor to sense that one of the pairs has lost current through a bypass transistor. Please refer to paper:                R. Hogervorst, J. P. Tero, R. G. H. Eschauzier, and J. H. Huising, "A Compact Power-Efficient 3V CMOS Rail-to-Rail Input/Output Operational Amplifier for VLSI Cell Libraries," IEEE Journal of Solid State Circuits, Vol. 29, No. 12, pp. 1505-1513, December 1994, which describes a two-stage, compact, power-efficient 3V CMOS operational amplifier with rail-to-rail input and output ranges.
An alternative technique is to increase the tail current bias on each side by a factor of 4 and to add additional devices inside each differential pair, which have a width 3 times that of the active devices. If the square-law operation is valid, gm will double, making up the deficit caused by the inactive pair, refer to below cited U.S. Pat. No. 5,208,552. In these implementations, the diverting transistor is 3 times wider than the driving transistor, which causes extra tail current added to the large signal limiting value. Hence slewing value doubles within the common input voltage range. To remedy this, a novel implementation that employs a diverting transistor of the same size as that of the driving transistor have been reported in                W. Redman-White, "A High Bandwidth Constant gm and Slew-Rate Rail-to-Rail CMOS Input Circuit and its Application to Analog Cells for Low Voltage VLSI Systems," in IEEE Journal of Solid State Circuits, Vol. 32, No. 5, pp 701-712, May 1997, which describes a new rail-to-rail CMOS input architecture that allows circuit behavior which is nearly independent of the common mode level with respect to transconductance and slewing characteristics.
Other approaches include:    a) controlling the sum total VGS−VT in the two pairs by current steering, and hence regulating the total gm, as referred to in            S. Sakurai and M. Ismail, "Robust Design of Rail-to-Rail CMOS Operational Amplifiers for a Low Power Supply Voltage," IEEE Journal of Solid State Circuits, Vol. 31, No. 2, pp. 146-156, February 1996, which describes new bias circuits which provide currents to n- and p-channel differential pairs placed in parallel. The bias currents are a function of the input common mode voltage to allow the total transconductance of the differential pairs to be constant over the entire common mode range.            b) overlapping the transition regions of the tail currents for the NMOS and PMOS pairs to achieve constant overall transconductance gm, as referred to in            M. Wang, T. L. Mayhugh, S. H. K. Embabi, E. Sanchez-Sinencio, "Constant-gm Rail-to-Rail CMOS Op-Amp Input Stage with Overlapped Transition Regions," IEEE Journal of Solid State Circuits, Vol. 34, No. 2, pp. 148-156, February 1999, which describes a design technique to maintain a constant gm input stage. The proposed technique overlaps the transition regions of the tail currents for the n- and p-pairs to achieve constant overall transconductance gm.
U.S. patents that relate to the present invention disclosure are:    U.S. Pat. No. 4,555,673 (Huijsing et al.) discloses a differential amplifier containing a pair of differential portions and a summing circuit with rail-to-rail input capability and controlled transconductance. A current control regulates the operating currents for the differential portions.    U.S. Pat. No. 5,208,552 (Ryat) teaches the use of a rail-to-rail operational transconductance amplifier having a first operating range where the two differential amplifiers are active and second and third operating ranges where only one differential amplifier is active. Means are provided such that the transconductance of the active transistors in one of the second or third ranges is equal to twice the transconductance of the transistors in the first range.    U.S. Pat. No. 5,323,120 (Ryat) shows an Operational Transconductance Amplifier (OTA) with complimentary input transistor pairs where a dummy diode is provided for each pair. When the common mode input signal is near the positive or negative supply voltage, one of the pairs turns off. The diode loads act to increase the current through the other pair when this occurs. This results in a constant transconductance over the entire common mode input range.    U.S. Pat. No. 5,334,948 (Fong et al.) describes a CMOS constant operational amplifier which has two differential input circuits each having a current source and a compensation circuit. Each compensation circuit dynamically tracks the common mode input voltage relative to a respective supply voltage and generates a respective tracking voltage that is used to modulate the current source of the respective differential input circuit. The operational amplifier maintains virtually constant open loop gain throughout its entire operating range.    U.S. Pat. No. 5,371,474 (Wassenaar et al.) shows differential amplifier similar to U.S. Pat. No. 4,555,673 described above, but uses FETs and allows square-root current control.    U.S. Pat. No. 5,384,548 (Sakurai et al.) presents rail-to-rail operation by placing NMOS and PMOS transistors in parallel so that at least one type of transistors are operating in a high gain region throughout the entire input range. A constant transconductance bias means enables the rail-to-rail CMOS differential stage to possess a constant transconductance over the entire common mode voltage range.    U.S. Pat. No. 5,574,401 (Spitalny) discloses a CMOS amplifier input stage comprising NMOS and PMOS differential pairs connected in parallel. The tail currents of these differential pairs are controlled to maintain a nearly constant effective total transconductance, i.e., the combined transconductances of both pairs remain at least approximately constant as the input voltage swings through its operating range.    U.S. Pat. No. 5,631,607 (Huij sing et al.) teaches compact gm control circuits which makes constant the sum of the gate-source voltages of the complementary input transistors and thereby the gm of the input stage. The circuit implements a floating voltage source between the N and P-channel input stage transistors and the positive and negative voltage supply rails.    U.S. Pat. No. 5,646,575 (Sauer) describes a composite amplifier which is constructed by connecting the corresponding input terminals of a high-frequency amplifier and a precision amplifier together. Also the output of the precision amplifier is connected to the offset trim port of the high-frequency amplifier.    U.S. Pat. No. 6,384,683 (Lin) describes an intermediate stage for a rail-to-rail input/output CMOS operational amplifier. It includes a floating current source separating two current mirrors, where the ideal current source includes a floating current mirror enabling an output quiescent current to be provided which does not vary with changes in the voltage rails or the common-mode input voltage. This enables elimination of input offset caused by the mismatch of the two current sources.
Most of the above U.S. patents describe methods to achieve constant transconductance bias to enable the rail-to-rail CMOS differential stage to possess a constant transconductance over the entire common mode voltage range.
Related art techniques to provide constant gm bias for rail-to-rail input stage require extra current consumption; either through the use of current monitor/control circuits or by level shifting. In the LVDS receiver applications where the input stage has to work up to 945 MHz, current consumption of the input stage is very high and any current monitor/control would consume a considerable amount of current.
Besides that, having a constant gm at the input stage does not mean that the voltage gain will be constant. If this input stage drives a load Rout, then the voltage gain will be gm*Rout, which will vary by at least +/−10% if Rout is an integrated resistor.
In contrast, the present invention maintains a constant voltage gain over a large input common mode voltage range and at the same time is power efficient.

High frequency receiver preamplifier with CMOS rail-to-rail capability


Absorbent structures comprising a continuous matrix of hydrophilic fibers, having dispersed therein particles of a water-insoluble hydrogel, are disclosed.

Water-insoluble hydrogels have been proposed for use in absorbent structures. A major drawback of the hydrogel materials is their relatively high cost, as compared to conventional absorbent materials like cotton and wood pulp fibers. A second drawback is a phenomenon called gel-blocking: when exposed to a fluid, the outer layers of a hydrogel particle swell, thus preventing fluid to reach the inner layers of the particle other than by a relatively slow diffusion process. Because of this gel blocking, hydrogel materials have relatively poor absorption kinetics.
One general approach towards solving this problem is to provide a multilayer structure, comprising one or more hydrogel containing layers and one or more wicking layers.
Examples of this approach are disclosed in: U.S. Pat. No. 4,364,992, issued Dec. 21, 1982 to Ito et al; U.S. Pat. No. 4,102,340, issued Jul. 25, 1978 to Mesek et al; and in EP-PA 83306764.8, publication No. 0 108 637.
A drawback of this approach is that the wicking layer does not have the excellent rewet properties of hydrogel material. Another drawback is the relatively high manufacturing cost of multilayer structures.
EP PA 8430 1578.5, publication No., 0 122 042, discloses absorbent structures comprised of a hydrophilic fibrous matrix having dispersed therein discrete particles of a water-insoluble hydrogel material. The structures are compressed to a relatively high density, so as to ensure good wicking.
Although this latter approach provides absorbent structures having a good performance in terms of rewet and absorbent capacity, there is still room for improvement. The high cost of hydrogel materials make a further increase of the absorbent capacity per gram of material highly desirable.
It is therefore an object of the present invention to provide a hydrogel-comprising absorbent structure having an improved absorbent capacity per gram of hydrogel material used.


A circular transducer array (30) is provided for use in recording a sound field. The array (30) comprises a plurality of microphones (31a–31h), a digital signal processor (33), frequency compensation filters (34) and a sum and difference network (35). The digital signal processor calculates the Fourier transform of sampled output signals from the transducers to produce a plurality of sound wave components specifying the sound field. The frequency compensation network (34) equalises each component using Bassel functions to flatten the apparent response of the array (30) and the sum and difference network (35) then combines the equalised components to provide a plurality of audio signals which represent the sound field.

Previous microphones have been developed primarily for use in sound reinforcement systems and for monophonic and stereophonic recording. Pressure microphones have an omnidirectional response, being equally sensitive to sounds arriving from all directions. First order gradient microphones were developed to provide a variety of directional responses, which can increase the potential acoustic gain in sound reinforcement systems in reverberant environments. These microphones also allow stereophonic recording with acceptable imaging within the loudspeaker angles. The gradient microphone is in many cases implemented as two closely spaced pressure elements with their outputs subtracted. This produces an approximation to the gradient, and a signal proportional to the sound velocity is obtained by integrating the difference signal.
Second order gradient microphones have also been developed which provide greater discrimination between sound from different angles of arrival. These typically consist of two gradient elements—each often consisting of two pressure elements—which produce the second spatial derivative with respect to one, or two axes. A pure second order response is obtained using the derivative with respect to two axes, and the four pressure elements form a square with their outputs combined with amplitudes of plus or minus one. This array produces a sin (2θ) polar response. A second square array is obtained by rotating the first by 45 producing a cos (2θ) response. If the outputs are integrated twice, then at low frequencies the response is constant with frequency. Alternative implementations consist of two pressure gradient elements, or a single diaphragm open to the atmosphere at four points, with two openings to one side of the diaphragm and two openings connected to the other to produce the appropriate signs.
Higher order devices may also be built using three or more gradient elements and similar implementation methods to that of the second order microphones. For each order m, an mth order integration is required to produce a flat response with frequency.
An alternative method for improving the discrimination of a microphone is to use two or more individual microphones, and to combine their outputs to produce one or more outputs which have higher directivity than a single element. More complex systems may be built using a larger array of microphones. Typically, prior art examples consist of a straight line of microphones with either equal or different inter-microphone separations, and use beam forming principles to produce one or more beams with sharp directivity in one or more directions.
Surround sound systems offer the potential for improved sound localisation over stereo systems. Early quadraphonic systems brought to light some of the issues that affect the quality of reproduction, in particular the limitations of small numbers of loudspeakers, and the importance of the functions used to place individual sound sources in the 360 degree sound field. The ambisonics system was developed independently by several researchers, and has proved to be a low order approximation to the holographic reconstruction of sound fields. The sound field is recorded using microphones that measure the spherical harmonics of the sound field at (theoretically) a point. The performance of the system becomes more accurate over wider areas as the number of loudspeakers and the number of spherical harmonics of the recorded sound field are increased.
All current ambisonics systems are first order: that is, they use a recording microphone which records only the zeroth (pressure) and first (x, y and z components of velocity) responses. A prior art microphone designed specifically for this purpose is the Soundfield microphone. Since only the first spherical harmonic, also termed spatial harmonic in the art, is available, the resulting reproduction demonstrates poor localisation.
Most surround systems use only the horizontal (x and y) components of the velocity, since a) lateral localisation is more acute than vertical localisation, and b) the use of the z component requires loudspeakers to be positioned above the listener, which is often impractical. In this case the spatial harmonics are obtained from microphones with azimuthal polar responses of the form cos (mθ) and sin (mθ). Each spherical harmonic greater than order zero therefore requires 2 channels. The total number of channels required to transmit or record all spatial harmonics up to order M is thus 2M+1.
Modem surround sound systems typically use five loudspeakers, and it has been shown that this allows the use of microphones which can measure up to the second order spherical harmonics of the sound field, requiring five channels. Surround systems using more than five loudspeakers will allow harmonics of orders greater than 2, and higher numbers of channels are required—for example, the inclusion of third order spherical harmonics require seven channels.
The recently introduced DVD-Audio disk allows the recording of six channels of audio. It is thus capable of carrying recordings from second order microphone systems. Future audio disk technology will provide greater numbers of channels. While some second and higher order microphones have been developed in the past, there are currently no microphone systems commercially available which can measure spherical harmonics of order two or greater. There is thus a technology mismatch between the reproduction capability that DVD disks offer and the recording technology that current microphones can provide. A practical need therefore exists for the development of microphone systems that can accurately record the higher spherical harmonics of sound fields in the horizontal plane, and in particular, the second order responses.
Consider a general sound pressure field p(x,y,z,t). The pressure in the plane z=0 is a three-dimensional function of x,y and t. This three-dimensional function may be equivalently expressed in terms of its three-dimensional Fourier transform
                              P                                (                                          k                ->                            ,              ω                        )                          =                  ∫                                    ∫                              -                ∞                            ∞                                                                  p                                                  (                                      x                    ,                    y                    ,                    t                                    )                                                                          ⅇ                                  -                                      j                                                              [                                                                        ω                                                                                t                                                +                                                                              k                            ->                                                    ·                                                      r                            ->                                                                                ]                                                                                ⅆ                t                                                          ⅆ                                  r                  ->                                                                                (        1        )            where {right arrow over (k)} is the vector wavenumber and (−j{right arrow over (k)}·{right arrow over (r)}) is chosen so that the pressure is represented by incoming waves which is relevant in surround systems, as opposed to outgoing waves in some texts. This equations shows that any sound field in the horizontal plane z=0 can be expressed as a sum of plane waves.
Writing {right arrow over (k)} in terms of its two components u=k cos (θ) and ν=k sin (θ), where k=|{right arrow over (k)}|, this may be written
                              P                                (                          u              ,              v              ,              ω                        )                          =                              ∫                          -              ∞                        ∞                                                        ∫                              -                ∞                            ∞                                                                  ∫                                  -                  ∞                                ∞                                                                            p                                                        (                                          x                      ,                      y                      ,                      t                                        )                                                                                ⅇ                                      -                                          j                                                                    (                                                                              ω                                                                                t                                                    +                          ux                          +                          vy                                                )                                                                                ⅆ                  t                                                                                ⅆ                  x                                                                                ⅆ                  y                                                                                (        2        )
As an example, a complex plane wave with radian frequency ω0, magnitude B, phase φ and angle of incidence θ0 has the formp(x, y, t)=Bej[ω0t+φ+k0 cos (θu)x+k0 sin (θ0)y]  (3)where k0=ω0/c and c is the speed of sound. The Fourier transform isP(u, v, ω)=A(2π)3 δ(u−k0 cos (θ0))δ(v−k0 sin (θ0))δ(ω−ω0)   (4)where, for convenience, A=BeJφ is the complex amplitude. The "spectrum" consists of a delta function at as ω=ω0, u=k cos (θ0), ν=k sin (θ0). Since P(u, v, ω) exists only at one point, it may be represented as a vector 10 in wavenumber-frequency space 11, as shown in FIG. 1. In the (u,v) plane, the vector 10 has a projection 12 which is a vector of radius k0=ω0/c and angle θ0 relative to the u axis.
A real plane wave is given by the real part of equation 3,
                                          p            R                                          (                          x              ,              y              ,              t                        )                          =                                            1              2                                    A                                                                                ⅇ                              j                                                  [                                                                                ω                        0                                                                  t                                        +                                                                  k                        0                                                                                cos                                                                          (                                                      θ                            0                                                    )                                                                                x                                        +                                                                  k                        0                                                                                sin                                                                          (                                                      θ                            0                                                    )                                                                                y                                                        ]                                                              +                                    1              2                                                                  A                                                                                *                                                  ⅇ                              -                                  j                                                        [                                                                                ω                          0                                                                        t                                            +                                                                        k                          0                                                                                cos                                                                                (                                                          θ                              0                                                        )                                                                                x                                            +                                                                        k                          0                                                                                sin                                                                                (                                                          θ                              0                                                        )                                                                                y                                                              ]                                                                                (        5        )            which can be written
                                          p            R                                          (                          x              ,              y              ,              t                        )                          =                                            1              2                                    A                                                                                ⅇ                                                                    jω                    0                                                      t                                +                                                      jk                    0                                                                          [                                                                                cos                                                                                (                                                          θ                              0                                                        )                                                                                x                                            +                                                                        sin                                                                                (                                                          θ                              0                                                        )                                                                                y                                                              ]                                                                                +                                    1              2                                                                  A                                                                                *                                                  ⅇ                                                                    -                                          jω                      0                                                                          t                                +                                                      k                    0                                                                          [                                                                                cos                                                                                (                                                                                θ                                0                                                            +                              x                                                        )                                                                                x                                            +                                                                        k                          0                                                                                sin                                                                                (                                                                                θ                                0                                                            +                              π                                                        )                                                                                y                                                              ]                                                                                (        6        )
The second term consists of a negative frequency complex plane wave with conjugate phase and the same positive wavenumber k0 propagating in the opposite direction θ0+π. The spectrum may be represented as two vectors in (u, v, ω) space. As ω0 and θ0 vary, the two vectors trace out a cone shape, since k=ω/c. Thus the spectrum of any two-dimensional spatial pressure field lies in the cone ω=±ck in the three-dimensional (u, v, ω) space.
The pressure field is obtained from P(u, v, ω) by the inverse Fourier transform
                              p                                (                          x              ,              y              ,              t                        )                          =                              1                                          (                                  2                                    π                                )                            3                                                                    ∫                              -                ∞                            ∞                                                                  ∫                                  -                  ∞                                ∞                                                                            ∫                                      -                    ∞                                    ∞                                                                                P                                                              (                                              u                        ,                        v                        ,                        ω                                            )                                                                                ⅇ                                          j                                                                    [                                                                              ω                                                                                t                                                    +                          uv                          +                          vy                                                ]                                                                                ⅆ                    u                                                                                ⅆ                    v                                                                                ⅆ                    ω                                                                                (        7        )
Writing P(u, v, ω) in terms of spatial polar coordinates, u=k cos (θ), v=k sin (θ), and p(x, y, t) in terms of polar coordinates x=r cos (θ), y=r sin (θ) yields
                              p                                (                          r              ,              ϕ              ,              t                        )                          =                              1                                          (                                  2                                    π                                )                            3                                                                    ∫                              -                ∞                            ∞                                                                  ∫                0                ∞                                                                            ∫                  0                                      2                                        π                                                                                P                                                              (                                              k                        ,                        θ                        ,                        ω                                            )                                                                                ⅇ                                          j                                                                    [                                                                              ω                                                                                t                                                    +                                                      kr                                                                                cos                                                                                (                                                                  θ                                  -                                  ϕ                                                                )                                                                                ]                                                                                k                                                                                ⅆ                    k                                                                                ⅆ                    θ                                                                                ⅆ                    ω                                                                                (        8        )
Since k=ω/c the integral over ω is only nonzero for ω=±kc. HenceP(k, θ, ω)=P(k, θ, ω)2π[δ(ω−kc)+δ(ω+kc)]  (9)and so
                              p                                (                          r              ,              ϕ              ,              t                        )                          =                                            1                              4                                                  π                  2                                                                                ∫                0                ∞                                                                            ∫                  0                                      2                                        π                                                                                P                                                              (                                              k                        ,                        θ                        ,                        kc                                            )                                                                                ⅇ                                          j                                                                                k                                                                          [                                                      ct                            +                                                          r                                                                                cos                                                                                (                                                                      θ                                    -                                    ϕ                                                                    )                                                                                ]                                                                                k                                                        ⅆ                    k                                                                                ⅆ                    θ                                                                                +                                    1                              4                                                                                π                  2                                                                                ∫                0                ∞                                                                            ∫                  0                                      2                                        π                                                                                P                                                              (                                              k                        ,                        θ                        ,                                                  -                          kc                                                                    )                                                                                ⅇ                                          j                                                                                k                                                                          [                                                                                -                              ct                                                        +                                                          r                                                                                cos                                                                                (                                  θ–ϕ                                  )                                                                                ]                                                                                k                                                                                ⅆ                    k                                                                                ⅆ                    θ                                                                                (        10        )
There are two special cases of interest. In the first, the signal contains only positive frequencies, (for example the complex plane wave considered above) and the pressure field is analytic. In this case the second integral is zero, and the analytic pressure field is
                                          p            a                                          (                          r              ,              ϕ              ,              t                        )                          =                              1                          4                                            π                2                                                                                ∫              0              ∞                                                                  ∫                0                                  2                                    π                                                                                P                                                        (                                          k                      ,                      θ                      ,                      kc                                        )                                                                                ⅇ                                      j                                                                                k                                                                    [                                                  ct                          +                                                      r                                                                                cos                                                                                (                                                                  θ                                  -                                  ϕ                                                                )                                                                                ]                                                                                k                                                  ⅆ                  k                                                                                ⅆ                  θ                                                                                (        11        )
The analytic case is useful for the analysis and design of surround systems.
The second case of interest is real pressure fields, which occur in practice. In this case the spectrum in polar coordinates has the propertyP(k, θ, −kc)=P*(k, θ+π, kc)  (12)
Substituting this in equation 10
                                          p            R                                          (                          r              ,              ϕ              ,              t                        )                          =                              1                          4                                            π                2                                                                                ∫              0              ∞                                                                  ∫                0                                  2                                    π                                                                          Re                                                  {                                                            P                                                                    (                                                  k                          ,                          θ                          ,                          kc                                                )                                                                                ⅇ                                              j                                                                                k                                                                                [                                                          ct                              +                                                              r                                                                                cos                                                                                (                                                                          θ                                      -                                      ϕ                                                                        )                                                                                ]                                                                                }                                                                                k                                                  ⅆ                  k                                                                                ⅆ                  θ                                                                                (        13        )
Equations 11 and 13 both show that the pressure field is completely specified by a two dimensional spectrum S(k, θ)=kP(k, θ, kc) which specifies at each frequency, the complex amplitude of the plane wave arriving from each angle θ. S(k, θ) may be termed the frequency-dependent source distribution. Since it is periodic in θ, it can be expanded in a Fourier series
                              S                                (                          k              ,              θ                        )                          =                  ∑                                                    q                m                                                          (                k                )                                                                ⅇ                              j                                                                                m                                                                                θ                                                                        (        14        )
The coefficients qm(k) are thus the "angular spectrum" of S(k, θ) at each spatial frequency k, given by
                                          q            m                                          (            k            )                          =                              1                          2                            π                                                                    ∫              0                              2                                π                                                                                S                                                  (                                      k                                                                                ,                    θ                                    )                                                                          ⅇ                                                      -                    j                                                                                m                                                                                θ                                                                                ⅆ                θ                                                                        (        15        )
The analysis is further simplified by examining each frequency component separately. In this case the sound field is "monochromatic", consisting of complex plane waves of the same frequency ω0 arriving from all directions θ. In this case
                              P                                (                          k              ,              θ              ,              kc                        )                          =                                            1              k                                                  S                                            (                                  k                  ,                  θ                                )                                              =                                                    2                                π                                            k                0                                                                δ                                            (                                  k                  -                                      k                    0                                                  )                                                                                S                0                                                          (                θ                )                                                                        (        16        )            where S0(θ)=S(k0, θ). Substituting this in equation 11 yields
                                          p            0                                          (                          r              ,              ϕ              ,              t                        )                          =                              ⅇ                          j                                                                                ω                0                                          t                                                      1                          2                            π                                                                    ∫              0                              2                                π                                                                                S                  0                                                                  (                  θ                  )                                                                          ⅇ                                  j                                                                                kr                                                                                cos                                                              (                                              θ                        -                        ϕ                                            )                                                                                ⅆ                θ                                                                        (        17        )
Thus a monochromatic sound field is expressed in terms of its one-dimensional source distribution. A simple example is a single plane wave with complex amplitude Λ arriving from direction θ0. The source distribution is a delta function at θ=θ0 and thus
                                          S                          0                                                                                θ                0                                                                    (            θ            )                          =                              2                        π                                                                          A                                                      ∑                                  m                  =                                      -                    ∞                                                  ∞                                                          δ                                                  (                                      θ                    -                                          θ                      0                                        -                                          2                                            m                                                                                π                                                        )                                                              =                      A                                                      ∑                                  m                  =                                      -                    ∞                                                  ∞                                                          ⅇ                                  j                                                                                m                                                              (                                              θ                        -                                                  θ                          0                                                                    )                                                                                (        18        )            and so the angular spectrum isqm=Ae−jmθ0   (19)
The monochromatic sound field may be written directly in terms of the spectrum of S0(θ) by substituting from equation 14,
                                          p            0                                          (                          r              ,                                                                        ϕ              ,              i                        )                          =                              ⅇ                          j                                                                                ω                0                                          t                                                                    ∑                              m                =                                  -                  ∞                                            ∞                                                                  q                m                                                          1                                  2                                    π                                                                                ∫                  0                                      2                                        π                                                                                ⅇ                                          j                                                                    [                                                                              m                                                                                θ                                                    +                                                                                k                              0                                                                                r                                                                                cos                                                                                (                                                                  θ                                  -                                  ϕ                                                                )                                                                                ]                                                                                ⅆ                    θ                                                                                (        20        )            which, with the identity
                                          j            n                                                        J              n                                                  (              z              )                                      =                              1                          2                            π                                                                    ∫              0                              2                                π                                                                                ⅇ                                  j                                                        [                                                                  n                                                                                θ                                            +                                              z                                                                                cos                                                                                (                            θ                            )                                                                                ]                                                                                ⅆ                θ                                                                        (        21        )            yields
                                          p            0                                          (                          r              ,              ϕ              ,              t                        )                          =                              ⅇ                          j                                                                                ω                0                                          t                                                                    ∑                              m                =                                  -                  ∞                                            ∞                                                                  j                m                                                                            J                  m                                                                  (                                                            k                      0                                                            r                                    )                                                                          q                m                                                          ⅇ                                  j                                                                                m                                                                                ϕ                                                                                (        22        )
This shows that the angular pressure field at radius r may be written as a sum of terms of the form exp(jmφ). These have been termed "phase modes" in antenna array literature and the same terminology will be used here. The magnitude of each phase mode is the spectral coefficient multiplied by a Bessel function of the first kind which describes how the phase mode varies radially.
An important feature of equation 22 is that for small k0r the Bessel functions of high orders are small and may be neglected without significantly affecting the pressure. Hence, for low frequencies, or for small radii, the phase mode expansion may be truncated to some maximum order m=±M . However, as the frequency or radius increases, M must increase to preserve the accuracy of the expression.
As an example, the pressure due to a single plane wave at angle θ0 is obtained from equations 19 and 22 with qm=A exp (−jmθ0)
                                          p                          0                                            θ                0                                                                    (                          r              ,              ϕ              ,              t                        )                          =                  A                                                                          ⅇ                          j                                                                                ω                0                                          t                                                                    ∑                              m                =                                  -                  ∞                                            ∞                                                                  j                m                                                                            J                  m                                                                  (                                                            k                      0                                                            r                                    )                                                                          ⅇ                                  j                                                                                m                                                              (                                              ϕ                        -                                                  θ                          0                                                                    )                                                                                (        23        )
Thus the pressure field due to a plane wave consists of phase modes with magnitudes given by Bessel functions.
By adding the terms in equation 22 m=l and m=−l, and noting that J−m(z)=(−1)m Jm(z), the phase mode expansion may be written
                                                        p              0                                                  (                              r                ,                ϕ                ,                t                            )                                =                                    ⅇ                              j                                                                                ω                  0                                                t                                                                [                                                q                  0                                                                                J                    0                                                                          (                    kr                    )                                                              +                                                ∑                                      m                    =                    1                                    ∞                                                                                j                      m                                                                                [                                                                        q                          m                                                +                                                  q                                                      -                            m                                                                                ]                                                                                J                      m                                                                                (                                                                        k                          0                                                                        r                                            )                                                                                cos                                                              (                                              m                                                                                ϕ                                            )                                                                                +                              j                                                                      ∑                                          m                      =                      1                                        ∞                                                                                j                        m                                                                                [                                                                              q                            m                                                    -                                                      q                                                          -                              m                                                                                ]                                                                                J                        m                                                                                (                                                                              k                            0                                                                              r                                                )                                                                                sin                                                                    (                                                  m                                                                                ϕ                                                )                                                                                ]                            (        24        )
Thus the pressure may be alternatively written as a sum of cosine and sine terms, which are known as amplitude modes. In cases where the spectrum of S(θ) is Hermitian (q−m=qmm), this can be written
                                          p            0                                          (                          r              ,              ϕ              ,              t                        )                          =                              ⅇ                          j                                                                                ω                0                                          t                                                      [                                                            q                  0                                                                                J                    0                                                                          (                    kr                    )                                                              +                              2                                                                      ∑                                          m                      =                      1                                        ∞                                                                                j                      m                                                                                Re                                                              {                                              q                        m                                            }                                                                                J                        m                                                                                (                                                                              k                            0                                                                              r                                                )                                                                                cos                                                                    (                                                  m                                                                                ϕ                                                )                                                                                -                              2                                                                      ∑                                          m                      =                      1                                        ∞                                                                                j                      m                                                            Im                                                              {                                              q                        m                                            }                                                                                J                        m                                                                                (                                                                              k                            0                                                                              r                                                )                                                                                sin                                                                    (                                                  m                                                                                ϕ                                                )                                                                                ]                                              (        25        )
The spectrum of the plane wave (equation 19) is Hermitian, and substituting for qm yields the simpler and well-known form
                                          p            0                                          (                          r              ,              ϕ              ,              t                        )                          =                  A                                                                                ⅇ                                                jω                  0                                                t                                                                [                                                                    J                    0                                                                          (                    kr                    )                                                  +                                  2                                                                              ∑                                              m                        =                        1                                            ∞                                                                                j                        m                                                                                J                          m                                                                                (                                                                                k                              0                                                                                r                                                    )                                                                                cos                                                                          (                                                      m                                                                                (                                                                                θ                                  0                                                                -                                ϕ                                                            )                                                                                )                                                                                ]                                                          (        26        )

Microphone arrays for high resolution sound field recording


A technique for controlling power consumption in a wireless device detects data frames indicating a pause in the reception of speech frames from the wireless network. The mobile unit places the receiver circuitry in a low-power or sleep mode to thereby reduce processor cycles and save battery power. At the end of a time period, the receiver circuitry awakens to receive and process additional speech frames or to return to the low-power mode if no additional speech signals have been received.

1. Field of the Invention
The present invention is directed generally to power control in a wireless device and, more particularly, to a system and method to control power consumption in receiver circuitry in a wireless device.
2. Description of the Related Art
Wireless communication devices, such as cellular telephones, are typically battery-powered. As such, an important design criteria is the minimization of power consumption by the battery-powered wireless communication device.
In a circuit-switched communication network, a continuous communication link is established between the wireless communication device and the communication network for the duration of the phone call. The wireless communication device includes a transmitter and a receiver to provide the bi-directional communication link with the communication network. In the past, power control and power consumption reduction had focused on the transmitter within the wireless device. Because the transmitter power can be significant, these efforts are well-founded. When the user is not speaking, the wireless communication device can reduce its transmitting power to thereby conserve battery power.
Although a reduction in transmitter power provides a savings, those skilled in the art will appreciate that other portions of circuitry within the wireless communication device consumes significant amounts of power. Therefore, it can be appreciated that there is a significant need for a system and method to control power consumption within the wireless communication device. The present invention provides this and other advantages as will be apparent from the following detailed description and accompanying figures.

System and method for power consumption control in a wireless device


A printing machine, having side walls and at least one form cylinder with an outer cylindrical surface carrying a removable sleeve-shaped printing form, the form cylinder having journals and being removably mounted in the side walls. A bearing rotatably supports the journals in the sidewalls and at least one of the side walls has an opening. A transport device moves the form cylinder back and forth through the opening in the side wall so that the sleeve of the form cylinder removed from the printing machine can be exchanged for a replacement sleeve and the form cylinder with the replacement sleeve can be moved back into the printing machine.

1. Field of the Invention
The invention relates to a printing machine with at least one form cylinder that carries a sleeve-shaped printing form which adheres frictionally to the outer cylindrical surface of the form cylinder and can be exchanged for a replacement sleeve by being removed from the outer cylindrical surface. The form cylinder is installed in the printing machine in a bearing, from which it can be removed, and has permanent preset interfaces to ensure that its bearing in the printing machine is correct in respect to the lateral and the circumferential register. There is a removal assembly to remove the form cylinder from its bearing. There is also a holder to hold the form cylinder at one of its journals, while the other journal is free, and a sleeve-changing device to remove the sleeve from the form cylinder and exchange it for the replacement sleeve.
2. Description of the Prior Art
From U.S. Pat. No. Re. 33,994, a printing machine is known that has an opening in its side wall so that a sleeve can be slipped through the opening onto a cylinder mounted in the printing machine. The cylinder is mounted and held at its journal on one side in the opposite side wall, while the other journal is uncovered.

Printing machine with at least one interchangeable cylinder


A large actuation area switching device includes a housing for holding a switch, means for compression and at least three slotted hinges. The slotted hinges create axes of operation such that a force applied to any point on the surface of the housing actuates the switch.

It is well known in the art to cover or enclose switches with a protective housing that in addition acts as an actuation mechanism. In a relaxed state, a top member of the housing sits directly over the switch but does not actuate the underlying switch. By applying an external force on the surface of the top member of the housing directly over the switch, the top member of the housing (or actuation mechanism attached thereto) is depressed to actuate the underlying switch. When the external force is removed from the surface of the top member of the housing, the flexible top member returns to a relaxed state.
A disadvantage of known actuation switching devices is that an external force must be applied at a specific point, and in a substantially perpendicular direction to the surface of the top member of the housing, in order to ensure that the top member of the housing (or actuation mechanism attached thereto) makes physical contact with the switch, thereby activating the switch. Accordingly, prior art actuation switching devices have numerous "dead" spots along the surface of the top member of the housing that would not activate the switch no matter how much external force is applied at those "dead" spots. Other prior art actuation switching devices attempt to eliminate the numerous "dead" spots by utilizing multiple switches. Utilizing multiple switches, however, increases manufacturing time and costs.
Another disadvantage of known actuation switching devices is the small size of such actuation switching devices. Known actuation switching devices tend to be not much bigger than the switches they cover. These known devices may be difficult to utilize if a user must activate a switch quickly, has both hands preoccupied, or has poor eyesight.
Accordingly, there is a need for a large actuation area switching device that can be activated upon applying a force anywhere on its surface.


The present invention relates to a method of providing an aromatic and flavorful precursor for use in a smoking article to alter the aroma of mainstream and sidestream smoke upon burning the cigarette during use. In particular, 2,3-pinanediol and transcinnamaldehyde are contacted together, preferably in the presence of an acid catalyst. The resulting aromatic and flavorful precursor is then collected.

The present invention relates to smoking articles such as cigarettes, and in particular to the synthesis of a precursor for altering the aroma and flavor characteristics of the mainstream and sidestream smoke of smoking articles.
Popular smoking articles, such as cigarettes, have a substantially rod shaped structure and include a charge of smokable material such as strands or shreds of tobacco (e.g., cut filler) surrounded by a paper wrapper thereby providing a so-called "tobacco rod." Numerous popular cigarettes have cylindrical filter elements aligned in an end-to-end relationship with the tobacco rod. Typically, filter elements are constructed from fibrous materials such as cellulose acetate, have a circumscribing plug wrap, and are attached to the tobacco rod using tipping material.
Cigarettes are employed by the smoker by burning one end thereof. The smoker then receives mainstream smoke into his/her mouth by drawing on the opposite end (e.g., filter end) of the cigarette. Typically, a person using a cigarette draws on or puffs the article about 5 to about 10 times, and each puff lasts about 0.5 second to about 2 seconds. Typically, a burning cigarette has a useful lifetime of about 1 minute to about 10 minutes. During the time that the cigarette is not being drawn upon by the smoker, it remains burning and sidestream smoke can be generated. Sidestream smoke is smoke which directly enters and diffuses into the atmosphere during the burning of a smoking article. The characteristic sight and odor of the mainstream smoke and the sidestream smoke may be perceived negatively by certain individuals.
There are several general approaches to altering the characteristic sight and odor of mainstream and sidestream smoke. One is to reduce the amount of sidestream smoke such as described, for example in U.S. Pat. Nos. 3,744,496 to McCarty, 4,231,377 and 4,420,002 both to Cline and 4,561,454 to Guess. Typically, this is accomplished by reducing the amount of tobacco consumed during the smolder period between puffs, or by reducing the amount of smoke generated during combustion. Another approach is to alter the aroma of the sidestream smoke such as described, for example in U.S. Pat. Nos. 4,941,486 to Dube et al. and 4,804,002 to Herron.
It would be highly desirable to provide a method of forming an aromatic and flavorful precursor useful in a smoking article and components thereof which prior to being employed by the user is odorless, and when employed provides highly pleasant smelling sidestream smoke and which delivers good tobacco taste to the smoker.

Method of providing an aroma and flavor precursor for smoking articles


A salt water supply unit includes a salt water plate that divides the interior of a salt water tank into a salt container and a salt water reservoir, and a salt water well that stands and penetrates the salt water plate. The salt water well accommodates a salt water valve device and a concentration detector. The salt water valve device includes a valve box having a valve hole that allows makeup water or salt water to flow therethrough, a float rod penetrating the valve hole, a valve element coupled to a first end of the float rod, and a water level detecting float coupled to a second end of the float rod. The concentration detector includes a switch that is incorporated in a stem holding a concentration detecting float. The switch outputs different detection signals in accordance with the position of the concentration detecting float.

A water softening apparatus removes hardness components in raw water such as tap water using an ion exchange resin bed (water softening treatment) to obtain soft water. Hardness component removing ability of the ion exchange resin bed is gradually decreased by continuous water softening treatment. Regenerating treatment of recovering the hardness component removing ability thus needs to be executed before the hardness component removing ability is lost, by causing the ion exchange resin bed to react with salt water (e.g. sodium chloride aqueous solution).
Recently provided is a water softening apparatus that automatically switches passages between raw water softening treatment and ion exchange resin bed regenerating treatment. This water softening apparatus includes a pressure tank (resin cylinder) accommodating an ion exchange resin bed configured to soften raw water, a control valve configured to automatically switch fluid passages upon switching between water softening treatment and regenerating treatment, and a salt water supply unit (salt water supply device) configured to supply the pressure tank with salt water used for regeneration of the ion exchange resin bed (see Patent Document 1).
The salt water supply unit includes, as main elements, a salt water tank, a salt water plate, a water level detecting float, a salt water well, and a salt water valve. The salt water tank accommodates a salt container configured to contain salt serving as a regenerant, and a salt water reservoir configured to reserve salt water that is generated from salt and makeup water (e.g. raw water) supplied from outside. The salt water plate is a water permeable member that partitions the interior of the salt water tank into the salt container and the salt water reservoir and allows salt to be placed on its upper surface. The water level detecting float is a member that is located inside the salt water well and is floatable on a water surface.
The salt water well is a cylindrical member that stands in the salt water tank so as to be divided from the salt container and to surround the water level detecting float. The salt water well has a communication hole (flow hole) allowing fluid to flow between the interior of the salt water well and the salt water reservoir. The communication hole of the salt water well prescribes, by its height, the maximum amount of salt water fed from the salt water reservoir into the salt water well, in other words, the maximum amount of salt water consumed by regenerating treatment.
The salt water valve is located in the salt water well and has a communication passage connecting the communication hole of the salt water well and the exterior of the salt water tank, a valve element configured to open or close the communication passage in accordance with the position of the water level detecting float, and the like. The salt water well vertically penetrates the salt water plate and is inserted to the bottom of the salt water tank (see Patent Documents 2 and 3).
The control valve switches the passages upon regenerating treatment in the water softening apparatus, so that salt water is imported from the salt water tank into the pressure tank and the ion exchange resin bed is regenerated. The salt water tank is supplied with makeup water after regenerating treatment, so as to generate salt water to be used for next regenerating treatment. Salt in the salt container dissolves in this makeup water, so that salt water of the saturated concentration is generated in the salt water tank.
Patent Document 1: Japanese Patent Laid-open Publication No. 2007-260574
Patent Document 2: Japanese Patent Laid-open Publication No. 04-108586
Patent Document 3: Japanese Patent Laid-open Publication No. 2011-31214

Salt water supply unit and water softening apparatus