A high efficiency blood pump includes a pump housing, wherein the pump housing provides an inlet and outlet. The pump includes a motor housing, wherein the motor housing contains a motor. An impeller is housed in the pump housing, wherein the impeller is radially supported by a hydrodynamic bearing providing at least one row of pattern grooves. A diaphragm provided by the pump housing separates the impeller chamber from the motor chamber. A magnetic coupling is provided between the motor and the impeller, wherein the magnetic coupling causes the impeller to rotate when the motor rotates and provides axial restraint of the impeller.

Some blood pumps mimic the pulsatile flow of the heart and have progressed to designs that are non-pulsatile. Non-pulsatile or continuous flow pumps are typically rotary and propel fluid with impellers that span the spectrum from radial flow centrifugal type impellers to axial flow auger type impellers.
A common issue encountered by blood pumps is blood damage. The causes of blood damage are mostly attributed to shear stress and heat generated by the bearings supporting the impeller and/or shaft seals of externally driven impellers. Shear stress and/or heat may cause hemolysis, thrombosis, and the like.
A great deal of effort has been devoted to reducing or eliminating blood damage in rotary blood pumps. One solution to minimizing/eliminating blood damage is to provide total hydrodynamic support of the impeller. For example, ramp, wedge, plain journal, or groove hydrodynamic bearings may be utilized to provide hydrodynamic support in blood pumps.
Additionally, passive permanent magnetic and active controlled magnetic bearings can be utilized to provide impeller support in blood pumps. Magnetic bearings may be combined with hydrodynamic bearings to provide total impeller support in blood pumps.
Some blood pumps provide blood flow utilizing a motor that has a shaft mechanically connected to an impeller. Shaft seals may be utilized to separate the motor chamber from the pump chamber. However, shaft seals can fail and generate excess heat allowing blood to enter the motor and/or produce blood clots. Some blood pumps incorporate electric motors into the pumping chamber, rather than providing separate motor and pumping chambers. For example, a stator may be provided in the pump housing and magnets can be incorporated into an impeller to provide a pump impeller that also functions as the rotor of the electric motor.
Heart pumps that are suitable for adults may call for approximately 5 liters/min of blood flow at 100 mm of Hg pressure, which equates to about 1 watt of hydraulic power. Some implantable continuous flow blood pumps consume significantly more electric power to produce the desired amount of flow and pressure.
High power consumption makes it impractical to implant a power source in the body. For example, size restrictions of implantable power sources may only allow the implantable power source to provide a few hours of operation. Instead, high power consumption blood pumps may provide a wire connected to the pump that exits the body (i.e. percutaneous) for connection to a power supply that is significantly larger than an implantable power source. These blood pumps may require external power to be provided at all times to operate. In order to provide some mobility, external bulky batteries may be utilized. However, percutaneous wires and external batteries can still restrict the mobility of a person with such a blood pump implant. For example, such high power consumption blood pumps have batteries that frequently require recharging thereby limiting the amount of time the person can be away from a charger or power source, batteries that can be heavy or burdensome thereby restricting mobility, percutaneous wires that are not suitable for prolonged exposure to water submersion (i.e. swimming, bathing, etc.), and/or other additional drawbacks.
The various embodiments of blood pumps discussed herein may be suitable for use as a ventricular assist device (VAD) or the like because they cause minimal blood damage, are energy efficient, and can be powered by implanted batteries for extended periods of time. Further, these pumps are also beneficial because they may improve the quality of life of a patient with a VAD by reducing restrictions on the patient's lifestyle.


A method for providing access to a socio-RBT service is provided. The socio-RBT service enables updating social networking website profile of a user with RBT related information of the user. The method enables, firstly, receiving socio-RBT subscription information from the user. The socio-RBT subscription information comprises at least one unique identifier of the user. Secondly, the method enables verifying one or more predetermined conditions related to the user. The one or more predetermined conditions facilitate to determine if the user is eligible to access the socio-RBT service. Further, the method enables mapping the unique identifier of the user with a unique identifier of the user's social networking website profile. The method further enables obtaining RBT subscription information corresponding to the mapped unique identifier of the user. The method enables, finally, updating RBT related information on the social networking website profile of the user corresponding to the RBT subscription information.

With advancements in communication technology, participative websites such as social networking websites are widely used to view user's profile information such as location, interests, hobbies, occupation etc. Further, social networking websites also facilitate users/subscribers to interact with each other. In addition, users/subscribers can also share pictures and send messages through their social networking website profile. Examples of some popular social networking sites may include MySpace, Orkut, Facebook, LinkedIn and Hi5. Over a period of time, these websites have gained popularity as they enable users to connect with existing and old friends, find new people sharing common hobbies and interests, and establish new business contacts etc.
Generally, the user's social networking website profile in a social networking website describes the user's personality traits. Further, the social networking websites provide updates on changes made by a user to the social networking website profile or any recent activity undertaken by the user on the social networking website. However, these updates and activities are limited to the ones carried out by the user when he accesses a particular social networking website using a data communications network, such as, internet.
Conventionally, the only method to update the social networking website profile of a user or undertake any activity is to access the social networking website over the internet. In certain example scenarios, when internet access is not available due to technical fault or may be because the user is in a location where internet connectivity is not provided, the user shall not be able to update his social networking website profile or perform any other activity on a social networking website. Further, if the user is not a regular user of the Internet, his social networking website profile may not be updated with his personality traits which may have changed over a period of time.
Moreover, traditional methods and systems do not provide any means to harness existing telecommunication services, such as, Value Added Services (VAS) for updating the social networking website profile. Various VAS, such as, RBT are indication of user preferences and personality traits. Enough information can be extracted from the RBT to update the social networking website profile of the user. As RBT provided by a telecommunication network is usually a monotonous sound heard by a caller while waiting for a callee to respond to a call, users have an option to select a RBT of their own choice by subscribing to a RBT service. The RBT selected by the user can be used to understand the personality traits of the user and make them available on his social networking website.
In light of the above, there is a need for a system and method for integrating social networking websites with VAS. Further, there is a need for a system and method for integrating social networking website with RBT services. In addition, there is a need for a system and method that would enhance the experience of other users/subscribers browsing through the social networking websites as they would be provided with additional information about a particular user, such as, the user's current emotional state, favorite song etc. compounded with the user's social networking website profile. Furthermore, there is a need for a system and method where the user's social networking website profile can be updated without requirement of Internet access.

Method and system for updating social networking site with ring back tone information


A method for predicting a pressure window for drilling a borehole in a formation includes: obtaining a pore pressure related data value of the formation using a data acquisition tool; predicting pore pressure uncertainty from the pore pressure related data value of the formation using a processor; estimating uncertainty of a pressure window for drilling fluid using the predicted pore pressure uncertainty using a processor; and applying the estimated uncertainty to the pressure window to provide a modified pressure window using a processor.

Geologic formations are used for many purposes such as hydrocarbon production, geothermal production and carbon dioxide sequestration. Boreholes are typically drilled into the earth in order to access the formations. Prior to a borehole being drilled, forces or loads in the rock mass of a formation are substantially in equilibrium with each other. Keeping the drilled formation stable generally requires a support pressure be applied by drilling mud in the borehole. The proper support pressure is related to the pressure of the formation fluid in the pores of the formation (i.e., pore pressure). If the applied support pressure is insufficient, the formation surrounding the borehole may become unstable and collapse into the borehole damaging equipment and causing costly delays, or formation fluid may enter into the wellbore causing a kick or even a blowout.
During drilling, the pressure of the drilling mud is maintained within a pressure window, for instance by a mud program. It is important that the pressure window is accurately determined in order to efficiently drill the borehole and prevent damage. Hence, it would be well received in the drilling industry if estimates of pore pressure were provided with an uncertainty that could be used as input to the mud program in order for the pressure window to compensate for the uncertainty. In particular, it would be well received if the pore pressure and associated uncertainty could be predicted ahead of the drill bit, i.e., before the formation is drilled.

Method to predict overpressure uncertainty from normal compaction trendline uncertainty


A polychromic image is reproduced and transferred onto a substrate by (a) providing a positive electrode moving at substantially constant speed along a predetermined path, the electrode having a passivated surface defining a positive electrode active surface; (b) forming on the positive electrode active surface a plurality of dots of colored, coagulated colloid representative of a desired image, by electrocoagulation of an electrolytically coagulable colloid present in an electrocoagulation printing ink containing a coloring agent; and (c) bringing an endless belt moving at the same speed as the positive electrode and having on one side thereof a colloid retaining surface adapted to releasably retain dots of electrocoagulated colloid, into contact with the positive electrode active surface to cause transfer of the dots of colored, coagulated colloid from the positive electrode active surface onto the colloid retaining surface of the belt and to thereby imprint same with the image. Steps (b) and (c) are repeated several times to define a corresponding number of printing stages arranged at predetermined locations along the path and each using a coloring agent of different color, thereby producing several differently colored images of coagulated colloid which are transferred at respective transfer positions onto the colloid retaining surface in superimposed relation to provide the desired polychromic image. A substrate is then brought into contact with the surface of the belt to cause transfer of the polychromic image from the colloid retaining surface onto the substrate and to thereby imprint the substrate with the polychromic image.

The present invention pertains to improvements in the field of dynamic printing. More particularly, the invention relates to an improved multicolor electrocoagulation printing method and apparatus.
In U.S. Pat. No. 5,538,601 of Jul. 23, 1996, Applicant has described a multicolor electrocoagulation printing method and apparatus in which use is made of a single positive electrolytically inert electrode in the form of a revolving cylinder having a passivated surface onto which dots of colored, coagulated colloid representative of an image are produced. These dots of colored, coagulated colloid are thereafter contacted with a substrate such as paper to cause transfer of the colored, coagulated colloid onto the substrate and thereby imprint the substrate with the image. As explained in this patent, the positive electrode is coated with a dispersion containing an olefinic substance and a metal oxide prior to electrical energization of the negative electrodes in order to weaken the adherence of the dots of coagulated colloid to the positive electrode and also to prevent an uncontrolled corrosion of the positive electrode. In addition, gas generated as a result of electrolysis upon energizing the negative electrodes is consumed by reaction with the olefinic substance so that there is no gas accumulation between the negative and positive electrodes.
The electrocoagulation printing ink which is injected into the gap defined between the positive and negative electrodes consists essentially of a liquid colloidal dispersion containing an electrolytically coagulable colloid, a dispersing medium, a soluble electrolyte and a coloring agent. Where the coloring agent used is a pigment, a dispersing agent is added for uniformly dispersing the pigment into the ink. After coagulation of the colloid, any remaining non-coagulated colloid is removed from the surface of the positive electrode, for example, by scraping the surface with a soft rubber squeegee, so as to fully uncover the colored, coagulated colloid which is thereafter transferred onto the substrate. The surface of the positive electrode is thereafter cleaned by means of a plurality of rotating brushes and a cleaning liquid to remove any residual coagulated colloid adhered to the surface of the positive electrode.
In order to provide a polychromic image, the negative electrodes, the positive electrode coating device, ink injector, rubber squeegee and positive electrode cleaning device are arranged to define a printing unit and several printing units each using a coloring agent of different color are disposed around the positive cylindrical electrode to produce several differently colored images of coagulated colloid which are transferred at respective transfer stations from the positive electrode active surface onto the substrate in superimposed relation to provide the desired polychromic image. The substrate which is in the form of a continuous web is partially wrapped around the positive electrode and passed through the respective transfer stations for being imprinted with the differently colored images in superimposed relation.
Since the paper web is brought into contact with the dots of colored, coagulated colloid produced by each printing unit, by the positive cylindrical electrode upon rotation thereof and pressed against the positive electrode active surface by pressure rollers for being imprinted with differently colored images of coagulated colloid, the web is often displaced between the positive electrode and the pressure rollers in a direction parallel to the longitudinal axis of the positive electrode. Accordingly, it is difficult to provide a polychromic image in which the differently colored images are perfectly superimposed.

Multicolor electrocoagulation printing method and apparatus


A hands-free telephone terminal includes a loudspeaker (HP), a microphone (MI) and loudspeaker gain control means (AUG, DIM, PP). A loudspeaker gain correction method cyclically determines a listening comfort index to deduce gain modification parameters. If the local user modifies the loudspeaker gain using the control means, the gain modification parameters weight the loudspeaker gain to optimize listening comfort during a telephone conversation for the local user and for the remote user.

1. Field of the Invention
The present invention concerns a loudspeaker gain correction method for a "hands-free" telephone terminal or for an audioconference telephone terminal.
2. Description of the Prior Art
A hands-free telephone set or telephone terminal includes a sound pick-up device with one or more microphones, a sound output device with one or more loudspeakers and transmit and receive signal processing circuits. These circuits include an acoustic echo canceller, an electric echo canceller and a gain variation device for attenuating the signals transmitted during a telephone conversation to prevent the Larsen effect. The attenuation is determined by the dominant transmission direction and by the performance of the echo cancellers.
A user controls the listening level by modifying the loudspeaker gain. The higher the chosen listening level, the less attenuation is applied to the non-dominant transmission direction. This attenuation is called the stability gain and takes a positive value less than unity. An excessively high attenuation, for example greater than 10 dB, would make listening more uncomfortable for the local user and for the other party, called as a remote user. The latter perceive variations in the levels of the speech signals transmitted and have the sensation of a half-duplex communication. When choosing the listening level, the local user is most sensitive to the sound intensity of the voice of the remote user and chooses an excessively high listening level. Unknown to them, this then causes a deterioration of the overall quality of the audioconference, in particular through a progressively more accentuated sensation of half-duplex communication. This sensation is all the stronger for the remote user if he is using the handset of his telephone.

Loudspeaker gain correction for a hands-free telephone terminal


A method and apparatus for protecting an energized inductive device such as an electromagnet from an open circuit, i.e., the loss of the power source for the inductive device. A diode is connected across terminals of the inductive device such that when the inductive device is normally energized, the diode is reversed-biased. A spark gap enclosed in a housing is connected in series with the diode. An inert gas fills the housing. A resistance in the form of one or more resistors is in series with both the diode and the spark gap. Upon the sudden loss of supply to the energized device, the diode, the resistance and the spark gap form a path for the discharge of energy from the inductive device.

1. Field of the Invention
The invention relates to controls for inductive devices and, more particularly, to a discharge device for a large inductive device such as an electromagnet.
2. Description of the Related Art
Large inductive devices are oftentimes incorporated into industrial applications. For example, an electromagnet is merely an encased inductor. Electromagnets can be used with a crane as lifting magnets in the steel industry for scrap material handling. The electromagnet is coupled to a magnet controller, which includes an electrical circuit that typically receives a DC voltage from a generator or other source and controls the voltage applied to, and thus the current flow through, the electromagnet.
The industrial applications in which these inductive devices are incorporated are such that the device and any controller are subject to harsh conditions in which damage to the equipment can easily result. For example, the conductors providing the power supply to a lifting magnet can be cut or otherwise disconnected from the lifting magnet. If the device is energized when it is abruptly disconnected from its power supply, a voltage level across its terminals can result high enough to damage or destroy the device. The typical rating of insulation for a lifting magnet is 600 volts. If the conductors are cut or otherwise disconnected, the voltage potential across the terminals of the lifting magnet can go as high as 10,000 volts, high enough to breakdown the insulation. The breakdown of the insulation can destroy the electromagnet, which is expensive to repair and/or replace.
In the case of electromagnets, one solution proposed has been the addition of a spark gap surge arrester including two electrodes, each connected to a separate terminal of the electromagnet. When the voltage level is high enough, the air gap between them breaks down. The resultant spark discharges the energy from the electromagnet. However, such arresters are exposed to damage themselves due to the harsh environments in which they are located.


A device for leaktight coupling of a tube to a tubular nose, the tube being provided with an outwardly-directed bead at a distance from its end, the tubular nose presenting an outside thread and including an inlet bore for defining a housing for an annular gasket and an annular gasket-retaining insert, the device including a nut having the tube passing therethrough and presenting an end inside thread for co-operating with the thread of the tubular nose and including a chamber behind the thread, the chamber terminating by a drive wall, and an axial drive collar removably placed between one of the flanks of the bead and the drive wall, the collar extending axially towards the end of the tube beyond the bead in the chamber to co-operate with the insert, slidable in its housing and shaped as a pusher for compressing the gasket between the bore and the tub.

In general, that type of device requires the tubes that are used to be well calibrated, and above all well supported in the nose so that the connection can be made properly leaktight. That is why the use of such devices is restricted to tubes of relatively small diameter for which the ratio of thickness over diameter is fairly large. With larger diameters, endpieces are fitted to the ends of the tubes, where such endpieces are made separately, with manufacturing tolerances that are under better control. The cost of couplings of that kind is naturally more expensive, particularly because of the need for prior assembly of endpieces onto tubes. In addition, when making an installation in situ, for example an installation for distributing a compressed fluid, it is often necessary to adjust the length of the tubes in the installation. It is then necessary for a tube to be connectable in the state in which it is then to be found, with a minimum amount of work being done on its cut end. This work consists in forming a bead, or more generally peripheral projections, on the tube so as to provide means for preventing the tube from moving axially in the coupling. This work leads to the tube being deformed, which is harmful for the leaktightness of the coupling. Finally, it should also be observed that in all devices in the state of the art, the sealing ring that is put into place is often injured or taken away by the end of the tube for coupling while it is being inserted into the tubular nose.

Device for leaktight coupling of a tube to a threaded tubular nose


A boosting portion switches between an N channel MOS transistor with high drivability and a P channel MOS transistor with low drivability for transmitting a high potential at an internal node to an output node. The N and P channel MOS transistors are respectively operated when boosted potential Vpp is low and high.

1. Field of the Invention
The present invention relates to a semiconductor device provided with a potential generating circuit boosting an externally applied power supply potential.
2. Description of the Background Art
Conventionally, a dynamic random access memory (DRAM) is provided with a boost circuit generating a potential higher than an externally applied power supply potential for driving a word line of a memory array.
FIG. 16 is a diagram showing an arrangement of the memory cell of the DRAM.
Referring to FIG. 16, a memory cell MC includes: an N channel MOS transistor 302 connected between a bit line BL and a storage node SN and having its gate connected to a word line; a capacitor 304 having its one end connected to storage node SN and the other end connected to a cell plate potential Vcp.
A substrate of N channel MOS transistor 302 is in most cases set at a negative back gate potential Vbb when a P type substrate is used. Cell plate potential Vcp applied to the other end of the capacitor is in most cases set at a potential half power supply potential Vcc.
Here, assume that an H (High) level is written as data to memory cell MC. Then, power supply potential Vcc is applied to bit line BL and N channel MOS transistor 302 is rendered conductive upon activation of word line WL. Power supply potential Vcc is transmitted to storage node SN.
FIG. 17 is a diagram shown in conjunction with a potential applied to N channel MOS transistor 302 when data at the H level is written to the memory cell.
Referring to FIG. 17, assume that storage node is initially set at a ground potential and then attains to power supply potential Vcc by application of power supply potential Vcc from bit line BL. In this case, N channel MOS transistor 302 has its drain D, source S, and gate G respectively connected to a bit line; storage node SN, and word line. When storage node SN attains to power supply potential Vcc, a large voltage of Vbbxe2x88x92Vcc is applied as a substrate bias voltage Vbs of N channel MOS transistor 302 because of substrate potential Vbb.
Inherently, a threshold voltage Vth of an access transistor used for the memory cell is set at a value greater than a threshold voltage of an N channel MOS transistor used for a usual peripheral circuit to reduce a subthreshold leakage current and to enhance refresh properties. As stated previously, if the source potential and substrate bias voltage Vbs increase, the threshold voltage of N channel MOS transistor 302 increases due to a substrate bias effect.
FIG. 18 is a graph showing a relationship between substrate bias voltage Vbs and threshold voltage Vth.
Referring to FIGS. 17 and 18, assume that the threshold voltage is Vt0 when substrate bias voltage Vbsr of N channel MOS transistor 302 is 0V.
When an L level is written to;storage node SN of the memory cell and the potential at storage node SN is 0V, the value of substrate bias voltage Vbs equals to substrate potential Vbb and threshold voltage Vth equals to threshold voltage Vt1 shown in FIG. 18.
Then, when data at the H level is written to the memory cell, storage node SN attains to potential Vcc, so that substrate bias voltage Vbs equals to |Vbbxe2x88x92Vcc|. Thus, threshold voltage Vth increases to attain to threshold voltage Vt2 shown in FIG. 18.
To enable transmission of power supply potential Vcc at the H level of bit line BL to storage node SN without causing any voltage drop, the potential of word line WL must be set; at a value higher than power supply potential Vcc by threshold voltage Vth.
FIG. 19 is a graph showing a relationship between a voltage written to the memory cell and a potential for activating the word line required therefor.
Referring to FIG. 19, a line G1 represents a potential transmitted to storage node SN of the memory cell. A line G2 represents a value obtained by adding the threshold voltage of the memory cell transistor to the potential of line G1. When 0V at the L level is written to the memory cell, the difference between lines G1 and G2 corresponds to threshold voltage Vt1 shown in FIG. 18. On the other hand, when power supply potential Vcc at the H level is to be written to the memory cell, line G2 becomes higher than line G1 by threshold voltage Vt2. A lower limit of the activation potential actually applied to the word line is obtained by further adding a margin to the potential of line G2 as depicted by a line G3.
The actual activation potential of the word line is set with reference to the case where the writing voltage requiring a high activation potential is power supply potential Vcc. Thus, line G3 equals to that indicating the activation potential of word line WL when power supply potential Vcc is changed.
Namely, the potential required for activation of the word line changes in accordance with the change in power supply potential Vcc and in consideration of the change in the substrate bias effect of the threshold voltage.
The activation potential of word line WL is in most cases boosted potential Vpp obtained by internal boosting.
FIG. 20 is a diagram shown in conjunction with a basic principle of a conventional boost circuit generating boosted potential Vpp.
Referring to FIG. 20, a boost circuit 310 includes: a diode 312 having its anode and cathode respectively connected to power supply potential Vcc and a node N11 for precharging node N11 to power supply potential Vcc; an oscillation circuit 316 generating a clock signal for a boosting operation; a capacitor 314 having its one end and the other end respectively connected to node N11 and an output of clock generation circuit 316; and a diode 318 having it anode connected to node N11 and cathode outputting boosted potential Vpp. When node N11 is precharged to power supply potential Vcc by diode 312 for precharging, node N11 is boosted to a value twice power supply potential Vcc from power supply potential Vcc by a clock signal generated by oscillation circuit 316 of which L and H levels respectively correspond to a ground potential and power supply potential Vcc. The boosted potential is output as boosted potential Vpp through diode 318.
It is noted that the foregoing description ignores a voltage drop in a forward direction due to diodes 312 and 318 for simplification.
FIG. 21 is a circuit diagram showing an actual arrangement of a boost circuit.
Referring to FIG. 21, a boost circuit 320 includes capacitors 321 and 322 having their one ends receiving clock signals CLK. The other end of capacitor 321 is connected to a node N12. The other end of capacitor 322 is connected to a node N13.
Boost circuit 320 further includes: an N channel MOS transistor 324 diode-connected to N12 from a node to which power supply potential Vcc is applied; an N channel MOS transistor 326 diode-connected to N13 from the node to which power supply potential Vcc is applied; and an N channel MOS transistor 328 connected between nodes N12 and N14 and having its gate connected to node N13 and its back gate supplied with substrate potential Vbb. Boosted potential Vpp is output from node N14.
Before operation, nodes N12 and N13 are precharged to power supply potential Vcc or a potential lower than power supply potential Vcc by a threshold voltage of the N channel MOS transistor. The precharge is performed by N channel MOS transistors 324 and 326 which are diode-connected.
Clock signal CLK is input, and the potential at one ends of capacitors 321 and 322 are boosted to power supply potential Vcc from 0V.
Then, nodes N12 and N13 attain to a potential twice power supply potential Vcc from power supply potential Vcc due to capacitive coupling. The potential twice power supply potential Vcc at node N12 is supplied to node N14 through N channel MOS transistor 328. At the time, boosted potential Vpp decreases by threshold voltage Vthn of N channel MOS transistor 328.
Namely, in the circuit shown in FIG. 21, the high potential at node N12 is decreased by the threshold voltage of N channel MOS transistor 328 for output.
Next, a conventional boost circuit capable of outputting higher boosted potential Vpp will be described.
FIG. 22 is a circuit diagram showing an arrangement of boost circuit 330.
Referring to FIG. 22, boost circuit 330 uses an N channel MOS transistor 334 having a triple-well structure for outputting boosted potential Vpp. N channel MOS transistor 334 has its back gate connected to a node N15.
FIG. 23 is a cross sectional view showing N channel MOS transistor 334.
Referring to FIG. 23, an N well 344 is formed in a main surface of a P substrate 342, and a P well 345 is formed in N well 344. N well 344 is connected to node N15 through an N type impurity region 346. P well 345 is connected to node N15 through a P type impurity region 350. Further, N channel MOS transistor MOS transistor 334 is formed in a main surface of P well 345. N channel MOS transistor 334 includes N type impurity regions 352 and 354 as well as a gate electrode 356. Impurity region 352 is connected to node N15, and a capacitor 332 is connected between gate electrode 356 and node NIB. Boosted potential Vpp is output from impurity region 354.
Node N15 is connected to P well 345 through impurity region 350. The potential at node N15 is transmitted to impurity region 354 through a PN junction between impurity region 354 and P well 345. Accordingly, the node at Vpp attains to a potential lower by a Pn junction voltage Vjv from a potential twice power supply potential Vcc. However, generally, since the PN junction voltage Vjv is lower than threshold voltage Vth of N channel MOS transistor 334, a higher boosted potential can be generated than in the case of the circuit shown in FIG. 21.
FIG. 24 is a circuit diagram showing an arrangement of a conventional boost circuit 360 capable of outputting still higher boosted potential.
Referring to FIG. 24, boost circuit 360 includes; a capacitor 362 having its one end supplied with clock signal CLK and the other end connected to a node N16; a level converting portion 364 having its input receiving clock signal CLK for amplifying the amplitude thereof for output; a capacitor 366 connected between an output of level converting portion 364 and a node N17; and N channel MOS transistor 368 having its gate connected to node N17 and outputting a boosted potential at node N16 as boosted potential Vpp when it is rendered conductive. N channel MOS transistor 368 has its back gate connected to a substrate potential Vbb.
FIG. 25 is a circuit diagram showing an arrangement of level converting portion 364 shown in FIG. 24.
Referring to FIG. 25, level converting portion 364 includes: an inverter 372 receiving and inverting an input signal IN; an N channel MOS transistor 374 connected between a ground node and a node N18 and having its gate receiving an input signal IN, an N channel MOS transistor 376 connected between a node N19 and the ground node and having its gate receiving an output from inverter 372; a P channel MOS transistor 378 connected between a node to which boosted potential Vpp is applied and node N18 and having its gate connected to node N19; and a P channel MOS transistor 380 connected between the node to which boosted potential Vpp is applied and node N19 and having its gate connected to node N18. An output signal OUT obtained by amplifying the amplitude of input signal IN is output from node N19.
Returning to FIG. 24, the operation of boosted circuit 360 will briefly be described. The gate potential of N channel MOS transistor 368 is boosted to a potential higher than a potential twice power supply potential Vcc by an output from level converting portion 364. Accordingly, the potential twice power supply potential Vcc at node N16 can be output as boosted potential Vpp without causing any potential drop.
FIG. 26 is a circuit diagram showing an arrangement of another boost circuit 380 which has been modified as in the case of boost circuit of FIG. 24.
Referring to FIG. 26, boost circuit 380 includes: a capacitor 382 having its one end supplied with clock signal CLK and the other end connected to a node N20; an inverter 384 receiving and inverting clock signal CLK; a capacitor 386 having its one end supplied with clock signal CLK and the other end connected to a node N21; a diode 388 precharging node N21 to power supply potential Vcc; a P channel MOS transistor 390 connected between nodes N21 and N22 and having its gate receiving an output from inverter 384; and an N channel MOS transistor 392 connected between node N22 and a ground node and having its gate receiving an output from inverter 384.
Boost circuit 380 further includes: a capacitor 394 connected between nodes N22 and N23; a diode 396 for precharging node N23 to power supply potential Vcc; and an N channel MOS transistor 398 connected between nodes N20 and N24 and having its gate connected to a node N23. Boosted potential Vpp is output from node N24.
FIG. 27 is a diagram showing waveforms in conjunction with the operation of boost circuit 380.
Referring to FIGS. 26 and 27, in the initial state, nodes N21 and N23 are precharged to power supply potential Vcc respectively by diodes 388 and 396. Then, when clock signal CLK rises from 0V to power supply potential Vcc, the potential at node N21 is boosted to a potential twice power supply potential Vcc from power supply potential Vcc. The potential is transmitted to node N22, and the potential at node N23 is boosted to a potential three times power supply potential Vcc from power supply potential Vcc by capacitive coupling of capacitor 394. More specifically, the potential at node N23 which has conventionally been set twice the power supply potential can be boosted to the potential three times power supply potential Vcc. Accordingly, the potential twice the power supply potential generated by capacitor 382 at node N20 can be transmitted by N channel MOS transistor 398 having its gate receiving the potential three times the power supply potential without causing any potential drop.
FIG. 28 is a circuit diagram showing an arrangement of a boost circuit 400 which uses a P channel MOS transistor at an output portion.
Referring to FIG. 28, boost circuit 400 includes: inverters 404 and 406 connected in series and receiving clock signal CLK; a capacitor 408 having its one end connected to an output from inverter 406 and the other end connected to a node N25; a level converting circuit 402 receiving clock signal CLK and converting the level thereof for output to node N26; and asp P channel MOS transistor 410 connected between nodes N25 and N27 and having its gate connected to a node N26.
P channel MOS transistor 410 has its back gate connected to a node N27. Boosted potential Vpp is transmitted from node N27. Boosted potential Vpp is also supplied to level converting circuit 402.
FIG. 29 is a circuit diagram showing an arrangement of level converting circuit 402.
Referring to FIG. 29, level converting circuit 402 includes: an inverter 412 receiving and inverting an input signal IN; an N channel MOS transistor 414 having its gate receiving input signal IN and connected between node N21 and a ground node; an N channel MOS transistor 416 connected between a node N29 and the ground node and having its gate receiving an output from inverter 412; a P channel MOS transistor 418 connected between a node to which boosted potential Vpp is applied and a node N28 and having its gate connected to a node N29; and a P channel MOS transistor 420 connected between the node to which boosted potential Vpp is applied and node N29 and having its gate connected to node N28.
Level converting circuit 402 further includes: a P channel MOS transistor 424 connected between the node to which boosted potential Vpp is applied and a node N30 and having its gate connected to N29; and an N channel MOS transistor 422 connected between node N30 and the ground node and having its gate connected to node N29. An output signal OUT from level converting circuit 402 is output from node N30.
Returning to FIG. 28, the operation of a boost circuit 400 will briefly be described.
Before operation, node N25 is precharged to power supply potential Vcc or a potential lower than power supply potential Vcc by the threshold voltage.
Then, a pulse is applied to clock signal CLK and the potential at node N25 is boosted to a potential twice power supply potential Vcc by capacitive coupling of capacitor 408.
At the time, a signal obtained by inverting a clock signal CLK is applied to the gate of N channel MOS transistor 410 by level converting circuit 402. The amplitude of the inverted signal has been amplified to attain to boosted potential Vpp from 0V. When the potential at node N25 attains to 2Vcc, the potential at node N26 attains to 0V. P channel MOS transistor 410 is rendered conductive for outputting the potential at node N25 without causing any potential drop. When clock signal CLK is at the L level, node N26 attains to boosted potential Vpp, and P channel MOS transistor 410 is rendered non-conductive.
FIG. 30 is a circuit diagram showing an arrangement of another exemplary boost circuit 430 which uses a P channel MOS transistor at an output portion.
Referring to FIG. 30, boost circuit 430 includes: inverters 434 and 436 connected in series and receiving clock signal CLK; a capacitor 438 having its one end supplied with an output of inverter 436 and the other end connected to a node N31; an inverter 432 receiving and inverting clock signal CLK; a capacitor 440 having its one end receiving an output of inverter 432 and the other end connected to a node N32; an N channel MOS transistor 442 diode-connected in a forward direction to a node supplied with power supply potential Vcc from node N31; an N channel MOS transistor 444 diode-connected in a forward direction to a node supplied with power supply potential Vcc from N32; and a P channel MOS transistor 446 connected between nodes N31 and N33 and having its gate connected to node N32. P channel MOS transistor 446 has its back gate connected to a node N33, from which boosted potential Vpp is output.
The operation of boost circuit 430 will briefly be described. First, before operation, node N31 is precharged to power supply potential Vcc or a potential lower than the power supply potential by the threshold voltage. When clock signal CLK changes from the L to H level, the potential at node N31 is boosted to a potential twice power supply potential Vcc by a capacitive coupling of capacitor 438.
At the time, the potential at node N32 is precharged by N channel MOS transistor 444 even if the potential is to decrease due to the capacitive coupling of capacitor 440. Thus, it is maintained at power supply potential Vcc. Namely, P channel MOS transistor 446 is rendered conductive since node N31 is twice the power supply potential and the gate is at power supply potential Vcc. Thus, the potential twice the power supply potential is transmitted to node N33 without causing any voltage drop.
On the other hand, when clock signal CLK falls from the H to L level, node N31 is precharged by N channel MOS transistor 442 and attains to power supply potential Vcc. Node N32 attains to the potential twice power supply potential Vcc due to the capacitive coupling of capacitor 440. Namely, the gate potential equals to boosted potential Vpp, so that P channel MOS transistor 446 is rendered non-conductive.
FIG. 31 is a schematic diagram shown in conjunction with a load circuit connected to the boost circuit.
Referring to FIG. 31, boosted potential Vpp output from boost circuit 310, previously described with reference to FIG. 19, is used as a power supply potential of a circuit which requires a boosting level such as a word driver 452 or a row decoder 454 of the DRAM. When the access operation of the DRAM starts, boosted potential Vpp decreases due to current consumption. If the potential is kept at a decreased level, the potential of the word line driven by word driver 452 does not sufficiently increase, or a time required for driving the word line increases. As a result, performance degradation or malfunction is caused.
If boost circuit 310 is always operated to maintain the level of boosted potential Vpp high, however, the DRAM generally consumes a greater amount of current. Then, measures are taken to reduce the amount of current consumed.
FIG. 32 is a block diagram showing an arrangement of generating boosted potential Vpp employed in the conventional case.
Referring to FIG. 32, a detector circuit 462 for monitoring boosted potential Vpp is arranged. Detector circuit 462 operates a ring oscillator 464 by an activation signal /OE to generate a clock signal when boosted potential Vpp decreases. Responsively, boost circuit 466 boosts boosted potential Vpp by a pumping operation. When boosted potential attains at least to a set potential, detector circuit 462 inactivates ring oscillator 464 to stop clock signal CLK and the pumping operation of boost circuit 466. Further, when a row-related command which causes semiconductor memory device to receive boosted potential Vpp and consume a large amount of current is input, for example, boost circuit 468 activated in synchronization with input control signal /RAS may be arranged.
FIG. 33 is a circuit diagram showing a first example of detector circuit 462 shown in FIG. 32.
Referring to FIG. 33, a detector circuit 462a of the first example includes: an N channel MOS transistor 472 connected between a node N34 supplied with boosted potential Vpp and a node N35 and having its gate connected to power supply potential Vcc; and a resistor 474 connected between node N35 and the ground node. Control signal /OE of an activation signal is output from node N35.
A transistor having a large threshold voltage is for example used for a memory array portion of N channel MOS transistor 472. In the case of detector circuit 462a, control signal /OE is controlled such that boosted potential Vpp equals to Vcc+Vth (memo). It is noted that threshold voltage Vth (memo) is a threshold voltage of N channel MOS transistor 452.
FIG. 34 is a circuit diagram showing a second example of detector circuit 462.
Referring to FIG. 34, a detector circuit 462b includes: a P channel MOS transistor 476 connected between node N34 supplied with boosted potential Vpp and node N36 and having its gate connected to node N36; a P channel MOS transistor 478 connected between nodes N36 and N35 and having its gate connected to power supply potential Vcc; and a resistor 480 connected between node N35 and a ground node. A control signal /OE is output from node N35.
In the case of detector circuit 462b, control signal /OE is controlled such that boosted potential Vpp equals to Vcc+2Vthp. It is noted that Vthp is a threshold voltage of P channel MOS transistors 476 and 478.
More specifically, when boosted potential Vpp falls below a set value, P channel MOS transistors 476 and 478 are rendered conductive and control signal /OE attains to the H level. When boosted potential Vpp attains at least to the set value, P channel MOS transistors 456 and 458 are rendered non-conductive and node N35 attains to the L level because of resistor 460, so that control signal /OE also attains to the L level.
Recently, the devices with the DRAMs are required to consume less power. Thus, in the DRAMs, externally applied power supply potential Vcc is becoming lower. Here, a DRAM operating with a low power supply voltage will be considered.
FIG. 35 is a graph showing a relationship between a power supply potential and a boosted potential.
Referring to FIG. 35, Vpp equals to Vcc at any point on a line G10, and Vpp equals to 2Vcc at any point on a line G14.
In the conventional boost circuit which has been described above, even an ideal circuit can generate Vpp as low as twice power supply potential Vcc. Namely, the level of boosted potential Vpp has a slope which is twice as sharp as the change in power supply potential Vcc. To write power supply potential Vcc to the memory cell, the activation potential of the word line must be a potential (a line G11) higher by the threshold voltage of the memory cell. In addition, an operation margin, control margin and the like are required, so that the potential of a line G13 is necessary for actually driving the word line of the memory cell. Namely, the boost circuit must output a potential higher than that of line G13.
However, even in the ideal boost circuit, boosted potential Vpp, i.e., an output potential, has a slope twice as sharp as that of power supply potential Vcc. Thus, a decrease in power supply potential Vcc results in a sharp decrease in the output potential. Then, a required potential (line G13) and the supplied potential (line G14) become equal at a point A. Therefore, a potential required for driving the word line cannot be generated on the lower voltage side of point A.
To achieve a circuit capable of ideally outputting a potential twice as power supply potential Vcc, conventionally, a triple-well process as shown in FIGS. 21 and 22 is used, the number of circuit elements is increased as shown FIGS. 23 and 25 to increase the gate potential, or the P channel MOS transistor is used at the output portion to prevent the decrease by the threshold voltage as shown in FIGS. 26 and 28. However, any of these measures suffer from the problems that the process becomes complicated, the number of circuit elements increases, or the element size of the P channel MOS transistor with less mobility increases, thereby resulting in increase in the layout area.
An object of the present invention is to provide a semiconductor device provided with a boost circuit which is capable of generating a suitable boosted potential Vpp even when an externally applied power supply voltage is low and which is advantageous in terms of the number of circuit, layout area, current consumption and process.
In short, the present invention is a semiconductor device provided with a voltage detecting portion, a clock signal generation circuit, and a boosting portion.
The voltage detecting portion detects a potential at a first node supplied with a boosted potential. The clock signal generation circuit generates an source clock signal in accordance with an output from the detection circuit. The boosting portion boosts an external power supply potential in accordance with the source clock signal for applying it to the first node.
The boosting portion includes: a precharge circuit precharging a second node to a prescribed potential; a boost circuit boosting the potential at the second node in accordance with the source clock signal; a first field effect transistor of a first conductivity type connected between the first and second nodes; a first driving circuit driving the gate potential of the first field effect transistor in accordance with the source clock signal; a second field effect transistor of a second conductivity type connected between the first and second nodes; and a second driving circuit driving the gate potential of the second field effect transistor in accordance with the source clock signal.
Therefore, a main advantage of the present invention is that a driver formed by the P channel MOS transistor is also used together with a driver formed by the N channel MOS transistor, so that a high boosted potential can be supplied while avoiding a problem of voltage drop by the threshold voltage of the driver, which is caused in the case of the N channel MOS transistor.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

Semiconductor device provided with boost circuit consuming less current


A digital FM base station radio having a dedicated digital signal processing (DSP) board operates on audio signals from RF links and land lines. The DSP board detects, filters and generates tones and communicates information regarding these tones to a controller microprocessor on the central control board for the radio.

In public service radio, it is common to superimpose control tones on audio signals. These control tones generally have sub-audible frequencies below 300 Hz, but may also be in the audible frequency range. These tones convey control commands and other information signals. The tones may be, for example, sent from one radio to another over an RF link or from a dispatcher console to a remote base station over land lines.
Tones are no longer used merely to remotely turn transmitters on and off and other basic control functions. Tones are performing an ever increasing variety of functions. Tones can be used to remotely control a base station or mobile transceiver receiver, monitor the operation and/or internal settings of a receiver, and send voting control information to central site controllers. It is impossible to predict how tones will be used in upcoming years, other than to say that tones will be used even more extensively than they are now used. For example, tones may be used to allow a mobile radio to link with a telephone connection at the base station and for many other radio operations.
Base stations, in particular, need to be able to encode and decode tones. It is often preferable to locate a base station near the antennas located on top of high buildings or on top of mountains. These inaccessible base stations are remotely controlled over land lines by one or more dispatcher consoles.
Tones are used to remotely control the base station. Furthermore, much of public service radio communications is between repeating base stations and remote mobile units and, thus, the base stations handle a large volume of the tone traffic in the system. Tone remote detection is typically used to remotely control base station systems. This coding allows a wide range of control functions to be implemented by remote tones. Tone remote detection is governed by industry standards that establish the format of tones and a library of their functions. The format for tone remote detection is a high volume secur-it tone (100 ms), a function tone (40 ms) and a hold tone if the function tone is a transmit function. The hold tone continues as long as a voice audio signal remains.
There are other kinds of tone codes used in public service radio. A common code is dual-tone multi-frequency (DTMF) coding for sending alphanumeric signals entered by a 12 or 16 pad keyboard. DTMF is generally referred to as "Touch Tone." DTMF coding is generally used to remotely turn on and off repeaters, especially the transmitter of the repeater. Type 90 tone is an older but still used tone code principally used to turn remote repeaters on and off. Type 90 coding uses single signals instead of the dual-frequency tones of DTMF.
Previously, base stations could not be easily adapted to accept new tones or handle an increasing volume of tone traffic. Prior base stations had separate hardware modules for each of the specific functions that were tone controlled. For example, a DTMF decoder module decoded the dual frequency alphanumeric tones of DTMF. Another module encoded DTMF signals. Similarly, tone remote control, voting tone generation, hold tone notching and Type 90 tone detection were each generated in separate modules. For example, the Ericsson-General Electric MASTR II Base Station Controller had separate plug in modules for tone remote control, tone generation and DTMF decoding.
Existing hardwired modules could not accept new tones without modification. Generally, another module was added to accommodate new tone types, assuming that the base station could be modified to accept new modules. Similarly, each module could only process a certain maximum amount of tone traffic. When the traffic exceeded the capacity of any one module, the base station had no ability to shift unused capacity in another module to the overloaded module. Accordingly, existing base stations do not have the capacity to handle new tones or large increases in the volume of any particular type of tone. Given the increasing use of tones, this inflexibility severely hampers the usefulness of existing base stations and the ease with which new tones can be added to the radio system.
The compartmentalized modules in prior base stations are bulky and complex. The numerous hardware modules increases the size and cost of the radio. Since each module has its own circuitry and logic units, and the modules interface with one another, the modules are complex and may be prone to failure.
Maintenance of modularized base station radios is time consuming and expensive. Modules are generally replaced when broken. The modules are not interchangeable with other modules in the base stations. Accordingly, a repair technician, who cannot generally predict which module is to be replaced before inspecting the radio, is required to carry a spare of every module in the radio or order a replacement for the broken module from the radio manufacture. It is impractical and prohibitively expensive to stock spare radio modules in every van of each repair technician. Thus, replacement modules are ordered from the manufacturer and the radio remains down (unusable) until the replacement module is received. Long down times for radios are abhorred, especially in public service radio systems which service police, fire squads, paramedics and other emergency units.
Maintaining and upgrading the performance of existing base stations generally requires the repair technician to visit the base station to make adjustments or add new components. Most prior base stations have adjustable potentiometers that are manually adjusted for each radio customer. Heat and other environmental factors affect the operation of these potentiometers. Accordingly, these potentiometers may need to be reset from time to time. The need for manual adjustments increases the need for and expense of maintenance of base station radios. Similarly, to upgrade a base station radio, such as to handle new tones, requires that a technician physically install new components into the radio and, possibly, manually adjust these new components. In short, prior base station radios lack flexibility and are expensive to maintain.
It has recently become known to provide remote mobile radio units with a digital signal processing board that plugs into the central controller board of the radio. U.S. Pat. No. 4,887,311, entitled "Radio With Options Board" issued on Dec. 12, 1989, to Terry Garner and Robert Dixon (the Garner Patent). The Garner Patent discloses an optional digital processor that interfaces with the control microprocessor for the radio. This digital processor allows the radio to handle several additional tone controlled functions. The digital processor receives processed RF audio from the radio's audio processor. The digital processor issues commands to the control microprocessor to implement these new tone controlled functions.
The digital processor disclosed in the Garner Patent works well with mobile radio units that communicate solely over an RF link but not over land or telephone lines. Moreover, the relatively low volume of traffic flowing through a mobile radio unit allows the existing audio processor to handle an add on digital signal processor. Finally, the radio control architecture disclosed in the Garner Patent is well suited to a mobile radio unit, but not to a base station. While the Garner Patent discloses a digital processor for mobile units, there remained a need for a flexible tone detection, filtering and encoding device for base stations having multiple audio inputs and handling a high volume of tone traffic.
This need for digital processing flexibility in a base station is satisfied by the present invention. We have developed a base station having a universal digital signal processing (DSP) module that is fully programmable. In the preferred embodiment, the DSP module is a piggy-back board that attaches to the central controller board (control shelf) of the base station radio. The DSP module preforms the tone decoding, filtering and generation previously performed by separate hardware modules. The DSP module has digital potentiometers that can be remotely programmed. All of the operating parameters of the DSP board can be programmed. Thus, the operating personality (e.g. operating parameters unique to the customer), ability to handle tones and maintenance adjustments can be programmed or reprogrammed into the DSP module without altering the hardware of the base station.
Moreover, the DSP board can be remotely monitored and programmed. For example, a technician can communicate directly with the radio board via a telephone interface, receive information regarding current settings and operation of the DSP board, and reset the DSP board including its potentiometers over the telephone. Accordingly, the technician can remotely diagnose and often remotely repair the base station. If the technician is required to physically visit the radio, he need only bring a single substitute DSP board, instead of the many hardware modules previously required.
A universal DSP board and digital signal processor replaces the various hardware modules previously required for signal processing. The DSP board is compact, inexpensive and flexible compared to the numerous hardwired modules used for tone control in prior base stations.
In the preferred embodiment, the DSP board includes two coder-decoder (codec) processors to handle the conversion of audio between analog and digital signals. Audio signals are received and transmitted over RF links, and over land lines and telephone lines. The DSP processor operates on the digitized audio signals through serial interfaces between each of the codecs.
The DSP board module interfaces with the controller board of the base station. A parallel communication interface including a dual port random access memory (RAM) device allows the controller board to communicate with the DSP microprocessor. The central controller can set the operating parameters of the DSP board, issue commands to the DSP microprocessor such as tone generation, and receive information derived from the audio signals by the DSP microprocessor.
The DSP board fundamentally handles tone detection, tone filtering and tone generation. These functions may be performed simultaneously. Each function may be enabled or disabled. Additionally, functions can be programmed into the DSP processor. Similarly, the controller can alter operating parameters for the DSP board, such as the potentiometer settings and codec channel assignments.
The DSP board of the present invention handles detection and decoding for DTMF, Type 90 single tones, and tone remote. The detection schemes employed by the DSP microprocessor all employ the Goertzel Algorithm to extract tone frequency information from the digitized audio signal. In addition, the DTMF decoding scheme includes several post-tests to prevent false detection of tones. Similarly, the tone remote decoding scheme has an energy-based algorithm that discriminates between tones having the same frequency such as secur-it, function and hold tones. When it recognizes a new valid tone, the DSP microprocessor passes the tone information it decodes to the controller microprocessor.
In the present invention, the DSP board provides tone filtering. It is known to use notch filters to remove a control tone superimposed on a audio signal. This filtering technique is known as "hold-tone filtering." Notch filters have previously been separate hardware modules in the radio. Incorporating the notch filter as a programmed function of the DSP microprocessor reduces the number of modules in the radio controller and allows for remote digital reconfiguration of the filter by reprogramming the microprocessor.
Similarly, in some applications, certain audio bands are notched out of the signal to prevent corruption of the control tone that is to be superimposed on the audio signal. This notching is "anti-false filtering" and is predominately used in conjunction with the 2-wire remote line interface of the base station.
Tone generation enables a base station to send control signals to external devices. The DSP board, in the preferred embodiment, can generate any tone having a frequency up to 3.2 KHz. The DSP processor is programmed with an algorithm used to generate tones. This algorithm includes sinusoidal look-up techniques to enhance the precision and efficiency of the tone calculations. By using this powerful and flexible tone generation algorithm, a single DSP processor has been substituted for several prior tone generation hardware modules.
The DSP board can function as an all digital, programmable compressor. Line audio inputs from several sources are filtered, converted to digital, and compressed by the DSP processor. The processor executes an audio compression program that selects and applies the appropriate gain to the digital signal. The compressed signal leaves the processor, is converted to analog form, filtered and routed to a variety of outlets such as an RF power transmitter or line links.
As a digital programable compressor, the DSP board eliminates hum and noise on the line input. In the preferred embodiment, the compressor outputs zero (0) voltage if the line input voltage is below a threshold value. Thus, the usual noise and hum from audio lines are eliminated.
The DSP compressor acts as a hard-limiter to prevent the compressor output signal amplitude from exceeding selected values. Moreover, the DSP processor provides digital control of the various threshold levels applied by the compressor. The DSP processor can be used to implement a software potentiometer. Accordingly, the compressor thresholds can be modified by resetting these software potentiometers in the DSP processor.
It is an objective of the present invention to improve the performance and flexibility of base stations by centralizing most of the tone decoding, filtering, compression and tone generation functions of a radio base station in a single DSP board. In addition, it is an object to reduce the size of base station radios, lower their cost, and simplify their maintenance and repair.
Furthermore, it is an object of the present invention to provide a universal digital signal processing board that can be easily reconfigured to meet various base station requirements. This flexibility allows the base station to be (re)configured either on site or remotely to promptly satisfy customer requirements or to handle new applications of control tones.

Digital signal processor for radio base station


A method for transferring oxygenated blood from a low pressure chamber to a high pressure chamber includes placing a conduit between the left auricle and the aorta of a patient, attaching a prosthetic valve at the aortic end of the conduit, filling the conduit with oxygenated blood from the left auricle and using the downward systolic force of blood in the aorta to create a Venturi effect in the aorta allowing the oxygenated blood in the conduit to flow from the low pressure chamber into the high pressure chamber.

The paradoxical flow valve relates to a valved conduit that enables the passage of fluid between a low pressure chamber, the left auricle, and a high pressure chamber, the aorta, in order to obtain incremental flow of oxygenated blood in the high pressure chamber without the need to increase the force of the left ventricle myocardial pump or replace it by a mechanical or natural heart.


A valve 100 comprising a one piece valve body 112 having an axial fluid bore 124 and a rotatable fluid control element 110. The body 112 includes an integral bracket 128 which provides an open access area between the bracket 128 and the main body 112 of the valve 100. A valve stem 130 is disposed within a stem bore 135, and 137 extending from the valve body 112 to the bracket 128, and engaging the flow control element 110. A contiguous single piece gland flange 142 secures packing 134 disposed between a valve body bore 137 and the stem 130. The stem 130 includes an enlarged shoulder 152 which engages a contiguous single piece shear bushing 148 having a diameter greater than the diameter of the stem bore 130, thereby preventing removal and/or blowout of the stem 130 without prior removal of the shear bushing 148.

This invention relates to a ball valve for the passage of fluids wherein the valve includes an integral bracket providing protection against blowout of the stem when subjected to high pressure and high temperature conditions, and more particularly to a ball valve with an integral bracket and a contiguous blowout prevention bushing.
Conventional ball valves are often subjected to extremely high pressures and temperatures in the various processes where they are used. Many prior art valves suffer in that they leak past seals associated with the rotatable closure members. The tendency for valves to leak increases under conditions of high pressure and high temperature, and is especially common in severe service valves which operate through a wide range of temperatures.
Ball valves operating under high pressure conditions often include a bonnet attached to the body of the valve to prevent blowout of the stem. The bonnet can be integral to the valve body, such as is disclosed in U.S. Pat. No. 6,095,493 to Velan, or can be separately bolted onto the valve body. However, the prior art bonnet designs suffer from shortcomings in their design.
The integral and bolt-on bonnet designs are similar in that they both cooperate with the stem to prevent blowout under high pressure conditions. One shortcoming of the prior art integral bonnet design is the required use of the split bushing and split glands that are necessary for the installation of the stem. The split gland and split bushing increase the number of critical parts for possible failure and increase the time necessary to install the stem as efforts must be made to ensure proper alignment of the stem within the stem passage. Misalignment of the stem in the stem passage of the bonnet can result in improper bearing of the axial load leading to leakage of the stem seals and unseating of the ball with the upstream and downstream seats. Furthermore, use of the split gland can result in an unbalanced compression of the packing rings, also leading to leakage in the valve.
The use of split-bushings requires the use of an additional bearing surface because the split bushing does not provide an adequate planar surface against which parts can freely move, instead requiring a thrust bearing located below the split bushing, and a stem bushing located above the split bushing. In addition, the prior art split bushing integral bonnet design features a long stem that extends above the bonnet. This creates a risk that axial movement of the handle can be translated through the stem to the ball, unseating the ball from the upstream and downstream inserts, and possibly damaging the seats.
Examples of valves featuring stems secured by plates and flanges are disclosed in U.S. Pat. Nos. 3,508,738, 4,342,444, 4,460,157 and 5,377,955.
In U.S. Pat. No. 3,913,610, Paptzun discloses a valve wherein the valve stem is contained within an integral housing. The housing is capped by a disc through which a threaded end of the stem extends. The opening through which the threaded end extends is smaller in diameter than the outer diameter of the stem, thereby providing a shoulder which secures the stem inside the integral flange housing.
In U.S. Pat. No. 4,475,712, DeJager discloses a valve de-signed to operate under high pressure conditions having an integral bonnet, wherein the valve stem is retained within the valve body. The valve stem has a shoulder with an outer diameter greater than the diameter of the stem passage. To install the stem in the DeJager valve, the body is equipped with an opening on the bottom through which the stem is inserted. The bottom opening is secured by a cover assembly which is secured into the valve body once the stem is inserted in the valve body.
Other patents of interest in the art include U.S. Pat. Nos. 4,479,513, 4,558,874, and 4,762,301.

Ball valve with shear bushing and integral bracket for stem blowout protection


Fibrous structures comprising a fiber flexibilizing agent system, methods for making such fibrous structures and sanitary tissue products comprising such fibrous structures are provided.

Conventional sanitary tissue products incorporate fibrous structures that typically contain fiber flexibilizing agents, such as softening agents. Fiber flexibilizing agents reduce the opacity of fibrous structures within which they are incorporated.
Accordingly, there is a need for fibrous structures that contain a fiber flexibilizing agent system wherein the net change in opacity of the fibrous structure resulting from the fiber flexibilizing agent system is greater than the net change in opacity of the fibrous structure resulting from individual components of the fiber flexibilizing agent system.

Fibrous structure comprising a fiber flexibilizing agent system


A service pin assembly for a machine includes a service pin and a tray for retaining the service pin. The tray is attachable to a frame of the machine, and is pivotable relative to the frame between a first position and a second position. In the first position, the tray facilitates a storage of the service pin with the machine. In the second position, the tray facilitates an engagement of the service pin with a lift arm of the machine and the frame to restrict a relative movement between the frame and the lift arm.

Machines, such as earth moving machines, construction machines, mining machines, generally include a lift arm and a work implement, such as a bucket that help the machine perform certain earth moving operations. Such work implements may be coupled to the lift arm, and may be raised and lowered by moving the lift arm, during material loading and transferring operations, for example.
For desired operational performance, regular servicing or maintenance of the machine may be performed. For inspection or maintenance of the lift arm, and of the components, such as actuators (such as fluid cylinders) associated with lift arm, the lift arms are generally maintained in a raised position. One way of holding the lift arm in the raised position is to extend the lift arm cylinder by operating a lever in an operator cabin and hold the lever in that position. However, the lift arm may be brought down if the actuators malfunction, or if a person unduly or unknowingly moves a lever associated with the operation of the actuators.

Caterpillar Underground Mining Pty. Ltd.


The present invention belongs to the field of natural medicine and pharmaceutical chemistry, and specifically relates to novel 2-substituted oleanolic acid derivatives of formula (I) or a pharmaceutically acceptable salt thereof, to a process for the preparation of these compounds, compositions containing such compounds and their use in preparing antineoplastic medicaments.

Oleanolic acid (OA), also known as caryophyllin, is a type of pentacyclic triterpenoids. It is extracted from the leaves and fruits of Oleaceae, Gentianaceae, Rubiaceae, Amaranthaceae, and the like, and is mainly present in free form and (or) in combination with saccharides. Many scientists, domestic and overseas, have conducted extensive research on pentacyclic triterpenoids. According to the literature, oleanolic acid and derivatives or analogs thereof exhibit a variety of biological activities, such as anti-inflammation, antitumor, antivirus, immunoregulation, inhibition of platelet aggregation, hypolipidemic, liver protection, kidney protection, anti-HIV, etc. (LI, Yingxia et al., An oleanolic acid-lactose conjugate, the preparation process and use thereof, [P] CN 1414012 A.2003; ZHANG, Yihua et al., An oleanolic acid derivative, the preparation process and use thereof, [P] CN 102070697 A.2011; Lin, Z. H.; Zhang, Y.; Zhang, Y. N.; Shen, H.; Hu, L. H.; Jiang, H. L.; Shen, X. Oleanolic acid derivative NPLG441 potently stimulates glucose transport in 3T3-L1 adipocytes via a multi-target mechanism. Biochemical Pharmacology. 2008. 76:1251-1262; Chen, J.; Gong, Y. C.; Liu, J.; Hua, W. Y.; Zhang, L. Y.; Sun, H. B. Synthesis and biological evaluation of novel pyrazolo[4,3-b]oleanane derivatives as inhibitors of glycogen phosphorylase. Chemistry & Biodiversity. 2008. 5: 1304-1312).

2-substituted oleanolic acid derivative, method preparing for same, and application thereof

Hangzhou Bensheng Pharmaceutical Co., Ltd.


A rotary hammer incorporating both a reciprocating drive for generating a first hammering action transmittable to a tool bit and ratcheting mechanism for generating a second hammering action transmittable to the tool bit. The first hammering action and the second hammering actions differing in frequency and force of the impacts transmitted to the tool bit. Furthermore, the reciprocating drive and ratcheting mechanism are selectably engageable so that the first hammering action and the second hammering action may be selectably transmitted to the tool bit individually or in combination depending on the desired mode operation.

One type of rotary hammers comprise a motor which rotatingly drives a spindle supporting a chuck in which a drill bit can be held, while at the same time causing a piston tightly fitted within the spindle to execute a linear reciprocating motion within the spindle. This motion causes repeated compression of an air cushion between the piston and a ram slidably mounted within the spindle, which causes the ram in turn to execute reciprocating linear motion within the spindle and apply impacts to the drill bit via a beat piece.
The problem with such designs is that the frequency of impacts per revolution of the spindle is relatively small.
In an alternative design of hammer drill, the impacts which are imparted onto the drill bit are generated using two ratchet plates which interact with each other, one of which is fixed, the other rotating with the spindle, the vibrations generated by two ratchets being transferred to the drill bit. EP0613758 discloses such a design.
Though this design produces a high frequency of impacts per revolution of the spindle, the size of the impacts is relatively small.

Rotary hammer having both a reciprocating hammer mechanism and a ratcheting hammer mechanism


A conductive paste contains metal powder, an inorganic binder, and an organic vehicle as main ingredients. The organic vehicle includes a solvent having a boiling point of 270° C. or higher, and the proportion of the solvent with respect to the entire solvent included in the organic vehicle is 3 to 100% by weight.

Since a conductive paste containing metal powder has good conductivity, the conductive paste is widely used for components of a variety of electronic devices. The conductive paste is used for forming conductor wiring of a wiring board. As the conductive paste, for Example, a paste formed by dispersing metal powder and an inorganic binder in an organic vehicle is used. To form conductor wiring, first, the conductive paste is applied to, for Example, a ceramic or a glass substrate in a predetermined pattern using a screen printer, a dispenser, and the like. Then, the applied conductive paste is baked at a high temperature so that the organic vehicle evaporates and the metal powder sinters. This forms a continuous membrane having good conductivity.
Since components of electronic devices have been densely packed, there is a need for efficiently forming a minute wiring pattern (fine pattern). More specifically, it is required to accurately form a fine pattern having a line width and a line interval of 100 μm or less. Therefore, a conductive paste for improving the accuracy of the fine pattern has been disclosed.
Patent Document 1 proposes a conductive paste, which contains spherical conductive powder having an average particle size of 0.8 μm or less and an organic vehicle. The ratio (D50/Dmin) between the median value D50 of the particle size of the conductive powder and the minimum value Dmin of the detectable particle size of the conductive powder is in the range of 2 to 5. Since using this conductive paste reduces waviness of the surface of a conductive pattern, a fine pattern having excellent shape accuracy is obtained. According to the above publication, the ratio (V1rpm/V10rpm) between the viscosity V1rpm measured with a Brookfield rotational viscometer using a No. 4 spindle at 1 rpm and the viscosity V10rpm measured with the same instrument at 10 rpm is preferably 2 to 5. Because of this characteristic, the conductive paste does not easily sag after being applied in a predetermined pattern. Thus, the form of the coated film is reliably maintained.
Also, Patent Document 2 proposes a conductive paste, which contains spherical metal powder having a particle size of 100 μm or less and a heat curable phenol resin as a binder resin. The conductive paste includes 0.01 to 5 wt % of a polyethylene resin with respect to 100 parts by weight of the metal powder. By using such a conductive paste, a fine pattern having excellent shape accuracy is formed, and therefore a high quality and high accuracy conductive circuit is manufactured.
In general, the wiring resistance of the conductive paste is required to be reduced for use in forming wiring with the conductive paste. To reduce the wiring resistance, it is effective to form a conductor wiring with a wide line width. However, widening the line width is often difficult due to the design, and there is a strong demand for narrowing the line width. Therefore, to reduce the wiring resistance, the thickness of the coated film must be increased in addition to reducing the volume resistivity of the conductive paste. Also, to increase the conductivity of the wiring, the conductive paste is required to be sufficiently sintered. However, the shrinkage rate of the conductive paste during drying and sintering is great, and the thickness after sintering is reduced to approximately 20% of the thickness when being applied. To suppress shrinkage, the proportion of the solid content such as the metal powder and the inorganic binder in the conductive paste may be increased.
However, in the conventional conductive paste, if the proportion of the solid content in the conductive paste is increased, the amount of the organic vehicle is relatively reduced. Therefore, the viscosity of the conductive paste is increased due to evaporation of a solvent in the organic vehicle, which affects the applying property of the conductive paste. For example, when forming a fine pattern on the wiring board by screen printing, a screen printing plate having a mesh with small openings is used. In this case, the increased viscosity of the conductive paste hinders the conductive paste from passing through the screen printing plate. This causes clogging of the screen printing plate. Thus, thin spots or disconnection might be created in the wiring, making it difficult to accurately form a fine pattern of 100 μm or less. In particular, when continuously printing for a long time, thin spots or disconnection are easily formed, making it even more difficult to accurately form a fine pattern. Also, when forming a fine pattern using a dispenser, the same problems as in the case of the screen printing occur since a nozzle with a small opening is used.    Patent Document 1: Japanese Laid-Open Patent Publication No. 2004-139838    Patent Document 2: Japanese Laid-Open Patent Publication No. 9-310006

Conductive paste and wiring board using same


An imaging system utilizes a plurality of sensors capable of sensing objects within a field of view about a sight line. At least two sensors have different sight lines with the sight lines having known relative positions. Each sensor produces signals corresponding to positions of objects within a field of view over time. At least one sensor signal memory receives those signals and stores them in a manner enabling concurrent access to signals received from any selected combination of sensors. The processing unit and associated memory contain at least one program for selecting sensor signals from a sensor signal memory. Preferably motion detectors are provided for determining vibration, flexure or movement of each sensor. A normalizing means is preferably provided to adjust the sensor or make an appropriate modification of the signal received from the sensor.

1. Field of the Invention
This invention relates to a system for creating images or tracking objects using a plurality of sensors.
2. Description of the Prior Art
Video images are frequently created to show a scene or record events occurring at a selected location over time. These images are frequently displayed on a video monitor wherein the image is comprised of a set of pixels. Each pixel has either an assigned grey level value or color. These images are created from signals emitted from sensors which are positioned to observe a scene. These sensors could be anything from video cameras to infrared detectors. Typically, the sensors produce analog signals corresponding to the scene which they observe. The analog signals are digitized to create digital images of the scene. Those digital images can be stored in a memory, displayed on a screen or directed to a variety of processing systems which may either extract information from the image or modify the image in accordance with predetermined procedures or reconstructed for display on a screen.
In many applications the sensor or optics associated with the sensor are moved to enable the sensor to survey across a desired field of regard. Such systems generate data in serial form as the sensor or the optics moves across the field of regard. The scan rate associated with such movement determines how rapidly an image can be created and can also affect the clarity of the image which is created. At the present time the data rate available from serially scanning systems is much lower than the ability of processors to handle the generated data. Hence, image processing capabilities have evolved which can process image data much faster than image data can be generated by the serially scanning systems.
When serial scanning is used, images are revisited and updated at a relatively low rate. These low update rates limit passive ranging performance as well as clutter discrimination. Serially scanned systems also have necessarily shorter detector dwell times which limit the sensitivity and detection range. The combined degradations in ranging, discrimination and detection can be severely limiting in tactical and surveillance applications.
Another problem associated with serial scanned systems is that they generally use gimballed optics and serial scan mechanisms which have moving parts that are costly and unreliable. Large protruding apertures are required to maximize coverage. For protection such apertures require spherical windows or greenhouse flat windows. Such spherical windows are generally not desired in aircraft because they make the aircraft easier to detect and also interrupt the aerodynamics of the airplane body. Gimballed optics are not generally compatible with conformal mounting if a large field of view is required. Costly assembly, alignment and maintenance is also characteristic of gimballed optics. Hence, there is a need for an image and tracking system which can cover a wide field of regard without using gimballed optics or other moving parts.
The art has suggested that serial gimballed sensor scanners be replaced with a large number of staring sensors fixed to a host platform. Staring focal plan arrays (FPA's) are distributed to obtain maximal coverage with minimal moving parts. Each array generates a series of signals corresponding to the field-of view which it observes. Those signals must normally be combined with signals from other arrays to generate a full field-of-regard. Since each array stares at its field-of-view, the processing time to create such images can be 1,000 times longer than is available with serial scan systems. Another problem with using parallel arrays is that platform motion can be crippling to long staring time sensors that are mounted on the platform. For example, a 100.degree. per second motion would move scene data across 116 pixels if each sensor's instantaneous field-of view is 150 .mu.r and the integration time is 0.01 seconds. Vibration levels can reach 10 pixels, peak to peak on common aircraft platforms. The resulting loss of signal to noise ratio as well as spatial information is a major problem for staring focal plane arrays.
In the majority of cases, the multiplicity of sensors required to achieve distributed aperture systems requires a greater processor load and increased complexity. Data is available from all distributed aperture scenes simultaneously for each frame. Previously, the parallel processing load has been considered unmanageable when scaled from conventional systems. For example, a distributed aperture concept can easily represent a 30-million pixel processing requirement. These pixels receive support on a parallel frame-to-frame basis. Superficially, multiple sensors appear more costly and complex as well.
Intra-sensor alignment is important for tracking and clutter discrimination. Relating data to a common inertial reference frame is also important for "pointing" targeting systems accurately. For multiple sensors sensor-to-sensor alignment is important. Sensors must be maintained in relative alignment to one another or the signals from them must be corrected to account for any misalignment which occurs.
Consequently, there is a need for an image and tracking system which can generate images from sensors subjected to motion and vibration. The sensors should either be positioned or movable to cover a wide field-of-regard. The signals from the sensors must be integrated and normalized in a relatively short time to account for overlaps in fields of view among the sensors and movement of sensors resulting from vibration or movement of the platform on which the sensors have been mounted.

Distributed aperture imaging and tracking system