Disclosed is a disk drive having a spindle motor, a disk that is rotated by the spindle motor, and a movable actuator arm that carries a read/write head. The head physically engages a parked, or home, position at the Inner Diameter (ID) of the disk when the spindle motor is not energized and the disk is stationary. The electrical energization that must be applied to the spindle motor in order to breakaway the head from the disk (i.e., the breakaway current), and the energization that is necessary to cause the motor to achieve a stable spinning state (i.e., the spin current) are monitored. Possible future failure of the disk drive is predicted as a function of any changes in these two-electrical parameters, as these parameters may change over a period of time; i.e., may change over a number of disk drive stop/start events.

1. Field of the Invention
This invention relates to the field of data storage using magnetic disk drives; for example, magnetic disk drive data storage. More specifically, the invention pertains to the field of predicting failure of a disk drive due to an increase in head to disk stiction, friction, and other physical phenomenon that affect the breakaway current and/or spin current of the disk drive""s spindle motor
2. Description of the Prior Art
The spindle or disk drive motor (i.e., the motor that rotates the spindle on which disks are mounted) of a Direct Access Storage Device (DASD) must be provided with enough current to first break the heads of the device away from physical contact with the disks, and thereafter bring the spindle motor to a stable spin condition. If the spindle motor has insufficient power to break the heads free of the disk surfaces, or if the motor has insufficient power to bring the disks up to operational rotating speed, the disk drive will not operate properly.
As used herein, the term breakaway current is the magnitude of the spindle motor energization (for example, current) that is necessary to overcome stiction, and other forces that cause the head to adhere to the surface of a stationary disk, whereas the term spin energization is the magnitude of spindle motor energization that is required to achieve a stable spin velocity of the disks and the spindle motor. In many disk drives, the magnitudes of these two electrical parameters are equal; however, they are usually not of the same magnitude in that the magnitude of the spin parameter is usually lower than the magnitude of the breakaway parameter.
Stiction is an art term that is used to define the sticking of read/write transducing heads to a recording disk surface when the disk is stationary and the heads are in physical contact with the disk. Stiction resists disk movement when the spindle motor is energized. The problem of overcoming stiction has been addressed in the art.
The publication RESEARCH DISCLOSURE, September 1991, at page 662, describes an arrangement in which, in order to assist in overcoming stiction, the disk spin motor is energized at the resonant frequency of the spin motor and its associated apparatus.
In the publication JA 60-242550, it is suggested that the head be moved radially of the disk prior to stating to rotate the disk, and in publication JA 62-295262 if energization of the disk motor does not cause movement of the disk, then a carriage motor is energized.
The publication JP 3-90840 suggests a procedure for measuring head stiction by selective rotation of a disk, and publication JP 3-105763 suggests detecting the variation in friction between a magnetic head an a recording medium, and sending a warning when the percentage of the variation factor of the friction variation exceeds a preset slice level.
Other examples contained in the U.S. patent art are as follows, which patents are incorporated herein by reference to indicate the background of the invention and to illustrate the state of the art.
U.S. Pat. No. 4,589,036 describes a disk drive unit wherein on start up the head(s) is first moved radially outward of the disk. When it is detected that the head(s) has arrived at a predetermined radial position, rotation of the disk begins. Radial movement of the head continues until disk rotation increases to a predetermined speed.
U.S. Pat. No. 4,839,754 describes the use of switching-type regulator power supply connected to a brushless DC spindle motor wherein a shunt capacitor connected to the input of the power supply operates to apply maximum possible power to the motor during start up, thus overcoming stiction-friction forces.
U.S. Pat. No. 4,970,610 overcomes the disk/head stiction effect by applying a sequence of current pulses to the disk drive motor at a frequency close to the resonant frequency of the rotary spring-mass system that is formed by the stuck assembly of disks and head suspensions.
U.S. Pat. No. 4,996,618 provides that, upon power off, the heads are moved to a disk area that is near the Contact-Start-Stop (CSS) area. Later, when power is reapplied to the disk drive unit, and before the disk rotates, a head actuator is energized to move the heads into the CSS area.
U.S. Pat. No. 5,018,029 describes the use of force perturbations to reduce the effect of stiction. Once it is detected that stiction has been overcome, operating voltage is applied to the disk""s spin motor.
U.S. Pat. No. 5,130,867 provides a piezoelectric actuator to load a head onto a disk so as to provide an operating range at a selected portion of a Stribeck diagram; i.e., a diagram that plots the friction coefficient between a head and a disk as a function of the rotational velocity of the disk.
While devices of the above type are generally useful for their intended purposes, the need remains in the art to detect or predict future disk drive failure by monitoring the electrical energization that must be applied to the spindle motor in order to cause the motor to begin to spin, and/or to cause the motor to achieve a stable spin state, wherein failure of the disk drive is predicted as a function of changes in one, or both, of these monitored electrical energizations. That is, a need remains for an insitu means for measuring and quantifying the stiction and friction present in a disk drive during use, and to use this information to alert the user to a potential failure problem before the problem actually occurs.
This invention predicts future failure of a disk drive due to a detected increase in head to disk stiction, and/or due to a detected increase in friction, and the like, that affects the ability of the drive""s spindle motor to achieve a stable spin state. An increase in stiction/friction may occur as the disk drive is used in a data processing installation, for example, as the disk drive experiences a relatively large number of stop/start cycles over a period of time. More specifically, the invention provides a method and apparatus for predicting disk drive failure by periodically measuring the breakaway current and/or the spin current of a disk drive or spindle motor. The motor""s breakaway current is the magnitude of the initial current that is required to overcome head/disk stiction and to thereby begin spinning the disk. The motor""s spin current is the magnitude of current that is thereafter required to bring the motor up to a stable and reliable spinning state whereat data processing can reliably occur. Usually, the motor""s spin current is of a lower magnitude than is its breakaway current. The invention responds to changes in breakaway current and/or spin current that may occur over a period of use, due for example, to repeated stop/start operations of the disk drive.
An object of the invention is to predict failure of a disk drive having a spindle motor, a disk that is rotated by the motor, and a head that physically engages the disk when the motor is not energized. The electrical energization that must be applied to the spin motor in order to cause head to breakaway from the disk and/or to cause the motor to begin to spin, and/or to achieve a reliable spinning state is monitored. Failure of the disk drive is predicated as a function of changes in these monitored electrical energizations.
As a feature of the invention, the rate of increase in these two motor energization parameters is compared to given magnitudes, and failure is predicted as a result of this comparison. This feature of the invention may also require that the number of disk drive stop/start operations exceed a given magnitude before the rates of increase of these two parameters are monitored.
These and other objects and advantages of the invention will be apparent to those of skill in the art upon reference to the following detailed description, which description makes reference to the drawing.

Method and apparatus for predicting failure of a disk drive

International Business Machines Corporation


A gas-circuit breaker includes a cylinder, a stationary piston, and a moving piston. The cylinder has a moving contact that is fixed on one end of a rod and has a gas exhaust that faces a stationary contact. The rod is inserted into the cylinder. The stationary piston is fixed to the container, and is fitted in an opening of the cylinder to create a puffer chamber. Due to movement of the rod, the stationary piston compresses arc-extinguishing gas, and the gas blows onto the arc through gas exhaust. The moving piston partitions the puffer chamber into a first puffer chamber and a second puffer chamber. Sliding of the moving piston changes the capacity of the first puffer chamber and the second puffer chamber according to the difference in pressure in the first puffer chamber and the second puffer chamber.

1. Field of the Invention
The present invention is related to a gas-circuit breaker installed in, for example, an electric-power substation and/or a switching station.
2. Description of the Related Art
A conventional gas-circuit breaker includes an arc-extinguishing chamber to extinguish an arc generated between contact. In such an arc-extinguishing chamber, a mechanical puffer is used to mechanically compress an arc-extinguishing gas (hereinafter, "gas") and blow the compressed gas onto an arc. In recent years, a thermal puffer is used in combination with the mechanical puffer to increase the pressure of the gas by using the heat of the arc.
The conventional gas-circuit breaker, in which thermal puffer and mechanical puffer are used together, is disclosed in Japanese Patent Publication No. H07-109744. FIGS. 5 and 6 are a cross sections of the conventional gas-circuit breaker disclosed in Japanese Patent Publication No. H07-109744 in a closed position (current is flowing) state and in an open position (current is interrupted), respectively.
As shown in FIGS. 5 and 6, a gas-circuit breaker is housed in a container 230. The container 230, part of which is shown in the figure, is filled with a gas, for example, sulfur hexafluoride (SF6), used for extinguishing an arc. The gas-circuit breaker includes a stationary contact 210 that is fixed to a first side of the container 230, and a moving contact 220 that is capable of moving linearly on a central axis X, by an operating device (not shown). Because of such a movement, the moving contact 220 is capable of physically contacting or separating from the stationary contact 210.
The stationary contact 210 has a stationary arc-contact 211 arranged on the central axis X. The moving contact 220 includes a moving arc-contact 221, a thermal chamber 222, and a pressure chamber 223. The moving arc-contact 221 moves linearly along the axis X with respect to the stationary arc-contact 211, and it is capable of electrically contacting or separating from the stationary arc-contact 211.
The thermal chamber 222 is located between the moving arc-contact 221 and the pressure chamber 223, and moves linearly on the central axis X along with the moving arc-contact 221 with the operation of a hollow operating rod 224. The pressure chamber 223 is configured of a cylinder 225 that moves linearly along with the moving arc-contact 221 and the thermal chamber 222, and a stationary piston 226 that is supported by the container 230. Due to opening movement of the moving contact 220 (i.e., movement towards right in FIG. 5), the volume of the pressure chamber 223 decreases, whereby the gas inside is compressed.
The thermal chamber 222 has two vents. One vent 222a opens towards the moving arc-contact 221 and another vent 222b opens in the pressure chamber 223. A check valve 222c is located between the thermal chamber 222 and the pressure chamber 223 in the vent 222b. The check valve 222c opens when the pressure inside the pressure chamber 223 is higher than the pressure in the thermal chamber 222, whereby the gas flows from the pressure chamber 223 into the thermal chamber 222. On the contrary, the check valve 222c closes when the pressure in the thermal chamber 222 is higher than the pressure in the pressure chamber 223, thereby preventing flow of gas from the thermal chamber 222 into the pressure chamber 223.
Furthermore, a relief valve 223a is located on the stationary piston 226. At the time of current interruption, when the pressure in the pressure chamber 223 increases above a predetermined pressure, the relief valve 223a opens. When the relief valve 223a opens, the gas inside the pressure chamber 223 flows into the container 230 whereby the pressure in the pressure chamber 223 from increasing above the predetermined pressure.
In closed position (i.e., when current is flowing), the stationary contact 210 and the moving contact 220 are in electrical contact, so that current flows between the stationary contact 210 and the moving contact 220. At the time of current interruption, the moving contact 220 moves to the right in FIG. 5, separates from the stationary contact 210, and an arc is formed between the stationary arc-contact 211 and the moving arc-contact 221.
When the interruption current is large, the temperature of the gas in the thermal chamber 222 increases due to heat of the arc, and the gas expands, leading to increased pressure in the thermal chamber 222. If the pressure in the thermal chamber 222 is higher than pressure of compressed gas in the pressure chamber 223, the check valve 222c between the thermal chamber 222 and the pressure chamber 223 closes. As the current reduces and becomes closer to 0, the highly pressurized gas in the thermal chamber 222 blows onto the arc that is generated between the stationary arc-contact 211 and the moving arc-contact 221 through the vent 222a. Thus, the arc is quenched and electric current is interrupted.
On the other hand, when the interruption current is small, rise in the temperature in the thermal chamber 222 is smaller. As a result, the gas inside the pressure chamber 223 is compressed due to interruption, and the pressure in the pressure chamber 223 is higher than the pressure in the thermal chamber 222. Therefore, the check valve 222c between the thermal chamber 222 and the pressure chamber 223 opens. As a result, the highly pressurized gas in the pressure chamber 223 passes through the thermal chamber 222 and the vent 222a, and blows onto an arc that is generated between the stationary arc-contact 211 and the moving arc-contact 221 so that the current is interrupted.
Thus, in the conventional technology, large current interruption performance depends on the capacities of the thermal chamber 222 and the pressure chamber 223. Because it is necessary to locate the thermal chamber 222 between the moving arc-contact 221 of the moving contact 220 and the pressure chamber 223, it is necessary to secure space between the stationary contact 210 and the stationary piston 226 proportionate to the capacity of the thermal chamber 222, in addition to the operation stroke of the moving contact 220.
Therefore, when the capacity of the thermal chamber 222 is increased along with the increase in the interruption current, the gas-circuit breaker becomes lengthy along the axis, and it is not possible to downsize the gas-circuit breaker. Furthermore, when the interruption current is smaller, even if the capacity of the pressure chamber 223 is reduced, space in the thermal chamber 222 becomes a dead space, and pressure of the gas cannot be increased.


An apparatus for forming a lesion in cardiac tissue includes an optical fiber for guiding a coherent waveform of a selected wavelength to a fiber tip. The wavelength is selected to have a low absorption in water. The fiber tip is contained within a guide member having a discharge bore for a direction of energy discharge to define an unobstructed light pathway from the fiber tip through a discharge end of the discharge bore. A fluid pathway is in fluid flow communication with the guide member to admit a bio-compatible flushing fluid to the discharge bore.

1. Field of the Invention
The present invention relates to surgical instruments for laser cardiac ablation procedures. More particularly, the invention relates to a wand including a fiber optic transmission channel for atrial cardiac ablation.
2. Description of the Prior Art
A. Atrial Fibrillation
It is known that at least some forms of cardiac arrhythmia are caused by electrical impulses traveling through the cardiac muscle tissue by abnormal routes. In a normal, non-arrhythmic heart, electrical nerve impulses travel in an orderly and well-defined fashion through the sinoatrial node and then through the atrioventricular node in order to create an orderly flow of nerve impulses that lead to contraction in the heart.
In cardiac arrhythmia, cardiac impulses travel disorderly and undesirable paths through the cardiac tissue leading to disorderly and inefficient contraction of heart muscle. These fibrillations prevent the heart from pumping blood efficiently and can lead to death.
B. Maze Procedure—Generally
One technique for treating atrial fibrillation is to surgically create lines in the heart muscle tissue (myocardium) whereby electrical conduction of nerve impulses is blocked or rerouted. This technique for creating lines of electrical blockage is referred to as the Maze procedure.
Initial approaches to performing the Maze procedure involved invasive surgery in which a series of linear incisions are made in the cardiac tissue and then sutured together. The lines of scar tissue that form in the incisions do not conduct nerve impulses and are intended to prevent disorderly contraction of the atrial tissue.
In a typical Maze procedure, up to six non-conductive lines are required. Each of the non-conductive lines is typically several centimeters in length. Once these lines scar and heal, they disrupt electrical pathways that may support atrial fibrillation. Examples of the Maze procedure and other surgical techniques for treating atrial fibrillation are described in Chiappini, et al., "Cox/Maze III Operation Versus Radiofrequency Ablation for the Surgical Treatment of Atrial Fibrillation: A Comparison Study", Ann. Thorac. Surg., No. 77, pp. 87–92 (2004) and Cox, "Atrial fibrillation II: Rationale for surgical treatment", J. Thoracic and Cardiovascular Surg., Vol. 126, No. 6, pp. 1693–1699 (2003).
C. Less Invasive Maze Procedure Technologies
Less invasive ablation techniques have also been utilized to perform the Maze procedure. In such techniques, the surgeon typically drags an electrode in a linear fashion along the endocardial (internal) or epicardial (external) surface to produce a series of focal lesions. The scaring created by the focal lesions is hopefully contiguous and non-conductive of electrical impulses. For endocardial use, standard ablation catheters or catheters with extended distal electrodes are employed. Epicardially, specially designed handheld probes with a distal electrode for the application of ablating energy are often used.
For the greatest likelihood of success in a Maze procedure, it is particularly important that the lesions created be transmural. A transmural lesion extends through the full wall thickness of the cardiac muscle at the location of the lesion. One factor that obstructs obtaining transmural lesions from an epicardial approach of the heart is the cooling effect of blood in and around the heart. This is a particular difficulty when radio frequency (RF) energy is employed. The application of RF energy relies exclusively on thermal diffusion to create transmural lesions. The cooling effect of blood within the atrium tends to limit the depth to which thermal lesions can be formed.
It is desirable to create a full thickness transmural lesion but undesirable to perforate the atrial wall. Perforation of the atrial wall leads to a weakening of the heart structure as well as significant bleeding during surgery that must be controlled.
Additionally, producing transmural lesions with RF energy tends to heat the surface tissue at the point of probe contact this. This tends to create burns and adhesion between the probe and the heart tissue. Such adhesions can insulate the probe from the heart tissue blocking the efficient application of energy. These procedures are also a problem for the surgeon and staff who often must stop to clean the tip of the probe.
A discussion of techniques and technologies for treating atrial fibrillation is set forth in Viola, et al., "The Technology in Use for the Surgical Ablation of Atrial Fibrillation", Seminars in Thoracic and Cardiovascular Surgery, Vol. 14, No. 3, pp. 198–205 (2002). Viola et al. describe numerous ablation technologies for treating atrial fibrillation with the Maze procedure. These include cryosurgery, microwave energy, radiofrequency energy, and laser ablation.
D. Laser Ablation and the Maze Procedure

Atraumatic laser tip for atrial fibrillation treatment


A memory controller scrambles input data and stores the scrambled data in a memory, and then allows the stored data to be read from the memory only once. The memory controller includes a true random number generator (TRNG) for generating a true random number and a pseudo-random number generator (PRNG) that uses the true random number as a seed to generate a pseudo-random number. A linear feedback shift register (LFSR) receives and shifts the pseudo-random number and then scrambles the input data using the shifted number from the LFSR. The scrambled data then is stored in the memory and the seed is stored in one of the same or a separate memory. In response to a read request, the seed is read and used to regenerate the shifted number to descramble the stored data. The stored seed is invalidated to prevent additional attempts at reading the data.

The present invention generally relates to data storage and memories and, more particularly, to a memory in which the data stored therein can be read out only one time.
Sometimes data in a system is set to be processed only once for security or efficiency reasons. For example, in edge-computing applications, for privacy protection, locally collected data must be processed to remove certain identification information before saving the data to the cloud. After processing the locally collected data, it is cleared from the processor memory. In secure content distribution applications, contents such as video or audio data distributed using a network protocol is received and saved until it is accessed for decoding and playback. Once the data is played, the distributed contents must be cleared or made invalid to comply with copyright protection requirements. Similar applications include communications between modules in a semiconductor system. For example, communications between a processing core and a security root usually include commands and requests that must be deleted or cleared after being acknowledged.
It would be advantageous to have a system that ensures data is securely stored and read only once.

Read-once memory and method of operating same


A bushing assembly adapted for application in vehicle suspension systems includes an outer, generally cylindrical bushing member, an inner generally cylindrical bushing member arranged concentrically within the outer member. The two bushing members are interconnected by an elastomeric member disposed there between and bonded thereto to permit limited rotational displacement between the external and internal bushing members. An angular position sensor is at least partially embedded within the elastomeric member and operative to produce an output signal indicative of the relative angular position of the external and internal bushing members. The sensor includes a stator assembly including a permanent magnet, a galvanomagnetic sensing element and a flux guide defining at least one pole face, and a rotor including a flux guide defining a second pole face. An air gap between the two pole faces varies dimensionally as a function of the relative angular position of the stator assembly and rotor.

Angular and linear position systems are widely used in automatic control systems as feedback-sensing devices in one or more control loops of the system. In the automotive industry, a relatively recent trend is providing control-by-wire in lieu of the more traditional control provided by mechanical linkages, such as cables, rods and the like.
With the goal of improving drive stability of automotive vehicles, mechanically assisted driver control has been studied as a way to reduce uncontrolled vehicle behavior, such as body yaw and roll, as well as skidding. Specifically, antilock braking systems has already come into use as means for preventing locking of the wheels during breaking. Additionally, there are proposed vehicle control systems such as traction control, which reduces wheel spin during acceleration, or vehicle stability control, which affords overall control of stabilization of vehicle behavior.
In recent years, various vehicular height regulator systems or vehicular height control systems have been developed for regulating vehicle body attitude. For example, one such vehicle height control system is disclosed in U.S. Pat. No. 4,838,563 to Konishi et al.
For providing accurate vehicular height control, it is essential that the vehicle height indicative signal generated by the vehicle height sensor accurately correspond to the actual height of the vehicle body. In order to make the vehicle height indicative signal value accurately correspond to the actual height, accurate alignment of the vehicle height sensor in mounting the sensor on the vehicle body becomes essential.
In the conventional process to adjust alignment of the vehicle height sensor in mounting the sensor on the vehicle body, a pivotal arm of a vehicle height sensor is fixed at a certain angular position, at which the sensor produces a vehicle height indicative signal indicative of the vehicular height coincident with a preset target vehicle height, by means of a pin. At this condition, the vehicle height sensor is fixed onto the vehicle body. Thereafter, a test load is applied to the vehicle body to adjust the vehicle height so that the height level of a suspension member, such as a suspension link or suspension arm, becomes equal to the highest level of the arm of the vehicle height sensor. Then, the sensor arm and the suspension member are rigidly connected for cooperation with one another. Thereafter, the shearing load is exerted on the pin to shear the pin to release the sensor arm from restriction. Also, the test load exerted on the vehicle body is released.
Such conventional processes require additional parts, such as a pin for fixing the sensor arm relative to the sensor body, and an additional jig for applying the test load. Furthermore, the aforementioned process requires substantial attention to cause lowering of efficiency in adjusting alignment of the vehicle height sensor, further increasing costs.
More recently, position sensors have come into use in a wide variety of related applications, such as such as determining the relative movement of a vehicle suspension system with respect to a supported vehicle body. Conventional suspension-type position sensors typically include a linear-type motion sensor that utilizes capacitor plates or an inductor to determine the distance between a component of the vehicle suspension system and the vehicle body.
Heretofore, the sensors and mechanical linkages used in connection therewith to determine the relative movement of a vehicle suspension system with respect to a vehicle body have been limited by the construction being placed within the respective vehicle in a location, which provides only linear of the vehicle suspension system with respect to the vehicle body. These placement limitations are a result of not only the construction of the sensor itself, but also of the mechanical linkages used to connect the sensor to a component of the vehicle suspension system and a component of the vehicle body.
Currently, electronically controlled suspension systems often require semi-active suspension systems or active suspension systems to provide active damping for a vehicle. In such suspension systems, sensors supply input signals, including vehicle suspension position, to an electronic control unit on a real time basis. This increased functionality requires that more and more sensors be incorporated within the vehicle body and suspension system, making sensor packaging, as well as cost, complexity and robustness, more and more problematic.

Vibration isolating bushing with embedded angular position sensor


A voltage detection circuit includes: an amplifier which amplifies a voltage difference between first and second input signals input into non-inverting and inverting input terminals of the amplifier via first and second input portions; a first signal line which connects the first input portion to the amplifier; a second signal line which connects the second input portion to the amplifier; a first capacitor connected in parallel to the first signal line; a second capacitor connected in parallel to the second signal line; a first filter element which has an inductor component and a resistor component and is connected in series to the first signal line between the first capacitor and the amplifier; and a second filter element which has an inductor component and a resistor component and is connected in series to the second signal line between the second capacitor and the amplifier.

A chip bead may be used in an electronic circuit such as a voltage detection circuit as a filter element for removing noise included in an input signal or the like. A chip bead is an electronic component through which a required signal is passed. The chip bead absorbs noise in a high frequency band of the signal, and discharges the absorbed noise in the form of heat.
Japanese patent application No. 2005-365378 discloses a technique of removing noise included in a signal by disposing chip beads in an electronic circuit built into a remote controller for earphones connected to a portable telephone.


The translation lookaside buffer (TLB) of a processor is kept in synchronization with a guest page table by use of an indicator referred to as a “T” bit. The T bit of the NPT/EPT entries mapping the guest page table are set when a page walk is performed on the NPT/EPT. When modifications are made to pages mapped by NPT/EPT entries with their T bit set, changes to the TLB are made so that the TLB remains in synchronization with the guest page table. Accordingly, record/replay of virtual machines of virtualized computer systems may be performed reliably with no non-determinism introduced by stale TLBs that fall out of synchronization with the guest page table.

Deterministic replay in a virtual machine creates an execution that is logically equivalent to an original execution of interest. Two executions are logically equivalent if they contain the same set of dynamic instructions, each dynamic instruction computes the same result in the two executions, and the two executions compute the same final state of the system (processor, memory and devices). Virtual machines are software abstractions of physical computer systems, generally using virtualization software, which is typically a thin layer of software that logically sits, and provides an interface, between hardware and a guest Operating System (OS). Virtualization is well known to those in the field of computer science. Some virtualization functionality, however, has recently been implemented in hardware, including in recent microprocessor designs (as described further below) and in recent input/output (I/O) devices. Accordingly, the term "virtualization software" may be replaced by the term "virtualization logic" to encompass implementations involving any combination of software and/or hardware virtualization functionality. The term "virtualization software" will be primarily used throughout the following description, but this usage should not be understood as a limitation on the scope of the invention.
A virtual machine-based deterministic replayer may support full-system replay; i.e., the entire virtual machine (VM), including guest operating system (OS) and guest applications, is recorded and replayed. During recording, all sources of non-determinism from outside the virtual machine are captured and logged in a log file. These include data and timing of inputs to all devices, including virtual disks, virtual network interface cards (NICs), etc. A combination of techniques, such as device emulation and binary translation, are used to ensure deterministic replay as long as the recorded device input data are replayed at the right times.
Certain central processor unit (CPU) instructions are non-deterministic. A non-deterministic instruction is one whose output is not determined entirely by its inputs or a current architectural state. For example, the x86 RDTSC instruction returns the current time expressed in processor clocks, RDPMC and RDMSR return the contents of performance counter registers, etc. Thus, the outputs of non-deterministic instructions can arise from the interaction of the VM with a non-deterministic unit such as a real time clock, which is a device that can be queried by a CPU with a RDTSC instruction, whose result is returned in real-time and depends on when the instruction is executed. Examples of other non-deterministic units include input devices (such as a keyboard, mouse, microphone, etc.) a thermal sensor, a transducer, a network card, a video camera, and so on. Such devices are non-deterministic because they produce inputs that cannot be predicted based solely on the state of the machine.
When executing application(s) within a VM, the virtualization software can record the complete execution behavior. Having saved this behavioral information, the user can replay that exact and complete behavior an unlimited number of times. This can be useful for debugging. For example, a user can record execution of the VM, and then attach a gdb debugger to the guest operating system or guest applications during replay. On replay, the user can look at memory, set breakpoints, and single step through the execution to identify problems and resolve them. Of course, record and replay have other applications too, any of which may benefit from the embodiments described herein.
Record and replay techniques may also be used to provide fault tolerance capabilities in a virtualized computer system, so that the virtualized computer system may continue to operate properly in the event of a failure in hardware, virtualization software or host software. One way of providing fault tolerance is to run two virtual machines (a "primary" virtual machine, and a "backup" or "secondary" virtual machine) in near lockstep.
FIG. 1 illustrates a method of providing fault tolerance by record and replay, using a backup VM supporting the primary VM. A primary VM 200-1 is the "real" VM that is actually communicating externally of the virtualized computer system. A backup VM 200-2 is configured to take over almost instantaneously if primary host 100-1 or primary VM 200-1 fails.
The primary VM 200-1 runs at least one VCPU 210-1 and the guest OS 220-1, supported by virtualization software, which may comprise a hypervisor 601-1 including a VMM (Virtual Machine Monitor) 300-1 and a VMkernel 600-1, on host system hardware 100-1 supporting a virtual disk 240-1. The secondary VM 200-2 also runs at least one VCPU 210-2 and the guest OS 220-2, also supported by virtualization software, which may comprise a hypervisor 601-2 including a VMM 300-2 and a VMkernel 600-2, on host system hardware 100-2 supporting a virtual disk 240-2. FIG. 1 shows a separate virtual disk 240-1, 240-2 for each VM 200-1, 200-2 for purposes of illustration, however, the primary VM 200-1 and secondary VM 200-2 in a fault tolerance configuration may share a common virtual disk, which may be managed and modified exclusively by the primary VM 200-1 until the secondary VM 200-2 takes over in the event of a failure of the primary VM 200-1. While the virtualized computer system illustrated in FIG. 1 includes virtualization software comprising a hypervisor, which further comprises a VMkernel and a VMM, this invention may be implemented in a wide variety of virtualized computer systems having a wide variety of configurations of virtualization software or virtualization logic, as described in the prior art, including, in particular, earlier-filed patents and patent applications assigned to VMware, Inc., the assignee of this patent application. For the purposes of this disclosure, any action performed by the VMkernels 600-1, 600-2 may be considered to be performed by virtualization software or virtualization logic in a broader sense, such as by the hypervisors 601-1, 601-2.
One way of keeping the two VMs 200-1, 200-2 in near lockstep for fault tolerance is to record (log) all non-deterministic inputs or events encountered by the primary VM 200-1 in log entries 280 and send the log entries 280 to the backup VM 200-2. The VMM 300-1 corresponding to the primary VM 200-1 records such logs and the VMkernel 600-1 sends the log entries 280 to the VMkernel 600-2 corresponding to the secondary VM 200-2. Non-deterministic inputs/events include, for example, (i) all inputs from the network external to the virtualized computer system, (ii) information regarding when virtual interrupts were delivered to the VCPU 210-1 due to external events, (iii) timer interrupts delivered to the VCPU 210-1, and (iv) timestamps delivered to the VCPU 210-1 when the VCPU 210-1 acquires the current time via various hardware functionality. The VMM 300-2 corresponding to the backup VM 200-2 then uses the log entries 280 to ensure that the backup VM 200-2 executes exactly the same instruction stream as the primary VM 200-1 (i.e., the backup VM 200-2 replays the log 280). The VMkernel 600-2 corresponding to the secondary VM 200-2 sends acknowledgments (ACK) 282 back to the VMkernel 600-1 corresponding to the primary VM 200-1, indicating which log entries 280 have been received at the secondary VM 200-2 and which log entries 280 have been replayed on the secondary VM 200-2.
Deterministic replay by the backup VM 200-2 requires that the replay on the backup VM 200-2 behave substantially the same during logging and replaying phases. However, the memory management unit (MMU) of modern CPUs may be a source of non-determinism. In particular, MMUs of modern CPUs that include hardware support for processor (CPU) virtualization may be a source of non-determinism. Both Intel Corporation and Advanced Micro Devices, Inc. have introduced processor designs with hardware support for processor virtualization. Support in Intel processor designs is typically promoted as Intel Virtualization Technology (Intel VT-x) and was formerly known by the code-name "Vanderpool," while support in AMD designs is typically promoted as AMD Virtualization (AMD-V) or Secure Virtual Machine (SVM) technology and was at one time known by the code-name "Pacifica." Persons of ordinary skill in the art will generally be familiar with both AMD and Intel designs for hardware-assisted virtualization, which are detailed in published design documents such as Advanced Micro Devices, Inc., AMD64 Virtualization Codenamed "Pacifica" Technology: Secure Virtual Machine Architecture Reference Manual (2005) and Intel Corporation, Intel® Virtualization Technology Specification for the IA-32 Intel® Architecture (2005). Despite some apparent differences in terminology, persons of ordinary skill in the art will appreciate the substantial similarity of AMD and Intel hardware-assistance techniques. Among other possible uses, embodiments of this invention may be used to enable deterministic replay in a virtualized computer system having such modern CPUs. This patent describes the invention(s) in relation to these specific Intel and AMD processor designs, although the invention(s) may also be implemented in connection with other processor designs. Thus, more specifically, the memory management unit (MMU) of modern CPUs (e.g., Intel VT-x or AMD-V CPUs) may use in-memory data structures (e.g., Nested Page Tables (NPT) or Extended Page Tables (EPT)) as well as on-the-chip data structures (e.g., Translation Lookaside Buffers (TLB)) for caching accessed entries of the in-memory data structures. The TLB may provide a source of non-determinism, as will be explained in more detail below.
FIG. 2A illustrates generally how a linear page number (LPN) 406 is translated to a machine page number (MPN) 410 by a MMU 450 in a modern CPU 110. LPN 406 is the virtual address page number used by guest OS 220 (and guest applications executing on the guest OS 220) to access virtual memory. LPN 406 is translated to a physical page number (PPN) 408, using guest page table 402 maintained by guest OS 220. The PPN 408 is a physical page number from the perspective of guest OS 220. However, in order to access the actual system memory, PPN 408 is generally translated to a machine page number (MPN) 410 in virtualized computer systems. Prior patents and applications assigned to VMware describe methods that may be used by virtualization software to translate guest "physical" addresses specified by a guest OS (e.g. PPN 408) to machine addresses (e.g. MPN 410) that can be used to access actual physical memory. These prior patents and applications describe "shadow page tables" generated by virtualization software and used by a MMU to translate guest virtual addresses (e.g. LPN 406) into machine addresses (e.g. MPN 410). In some modern CPUs 110, however, the MMU 450 can translate the LPN 406 to a MPN 410 using guest page table 402 along with NPT or EPT 404. NPT or EPT 404 is typically maintained by virtualization software, such as VMM 300. As described in existing literature and as known in the art, the MMU 450 may retain a limited number of various mappings, including mappings from LPN 406 to PPN 408 and mappings from LPN 406 to MPN 410, among others, in a TLB 454 and in paging structure caches 456, to improve memory access times. In general terms, when translating a LPN 406 to a MPN 410, MMU 450 typically first looks in TLB 454 for the required mapping. If a valid mapping from LPN 406 to MPN 410 is found, the cached mapping is generally used, and the MMU 450 generally does not need to use the guest page table 402 or the NPT or EPT 404 to determine the appropriate translation. If a valid mapping from LPN 406 to MPN 410 is not found, however, the MMU 450 must generally perform a page table walk to determine the translation. Such a page table walk is described below in connection with FIGS. 2B and 2C.
Prior patents and applications assigned to VMware have used the terms GVPN (Guest Virtual Page Number), GPPN (Guest Physical Page Number) and PPN (Physical Page Number) in describing address translations in virtualized computer systems. LPN, as used in this patent, is analogous to GVPN, as used in some prior VMware patents; PPN, as used in this patent, is analogous to GPPN, as used in some prior VMware patents; and MPN, as used in this patent, is analogous to PPN, as used in some prior VMware patents.
FIG. 2B illustrates in greater detail how the MMU 450 performs a page table walk on the guest page table 402, according to one configuration, to translate from LPN 406 to PPN 408, and further uses NPT or EPT 404 to translate from PPN 408 to MPN 410. For purposes of this patent, a translation from LPN 406 to PPN 408 will be referred to as a "guest translation," while a translation from PPN 408 to MPN 410 will be referred to as a "host translation." Although the terminology used by Intel for guest page tables and EPT and the terminology used by AMD for guest page tables and NPT is different, the structure and use of these page tables are substantially similar, and, although the following description uses terminology from Intel literature, a person of skill in the art will also understand the structure and process as they relate to AMD CPUs, as well as other possible hardware-assist CPUs. FIG. 2B shows a 3-level structure for guest page table 402, although structures having different numbers of levels are also possible. A person of skill in the art will understand other possible structures and their use, based on existing literature, including, in particular, relevant literature from Intel and AMD. Thus, guest page table 402 comprises a page directory 402-1, a page table 402-3 and a page frame 402-5. Actually, as is well known, virtualized computer systems typically comprise numerous guest page tables 402, each with its own page directory 402-1, and each guest page table 402 typically comprises a plurality of page tables 402-3 and a plurality of page frames 402-5, however, for simplicity, FIG. 2B shows only the page directory, page table and page frame involved in a current address translation. The page directories 402-1 and the page tables 402-3 are referred to collectively herein as "guest page table pages," while the page frames 402-5 are referred to herein as "guest data pages."
As also shown in FIG. 2B, linear address 406A comprises a directory value 406-1, a table value 406-2 and an offset value 406-3. LPN 406 comprises the directory value 406-1 and the table value 406-2. Along with guest page table 402, control register CR3 412 is also maintained by guest OS 220. CR3 412 specifies a base address for page directory 402-1 in the form of a PPN (or in the form of a physical address, depending on the paging mode). MMU 450 performs a host translation 409-1 to translate this PPN into MPN 410-1 using NPT/EPT 404. The structure of NPT/EPT 404 and the process for its use in translating from PPN to MPN is described below in connection with FIG. 2C. MPN 410-1 specifies the base address of page directory 402-1 in terms of a machine address. The directory value 406-1 is then used as an index into page directory 402-1 to select page directory entry 402-2. Entry 402-2 specifies the base address for page table 402-3 again in the form of a PPN. MMU 450 performs another host translation 409-2 to translate this PPN into MPN 410-2 using NPT/EPT 404. MPN 410-2 specifies the base address of page table 402-3 in terms of a machine address. The table value 406-2 is then used as an index into page table 402-3 to select page table entry 402-4. Entry 402-4 specifies the base address for page frame 402-5 again in the form of a PPN. MMU 450 performs another host translation 409-3 to translate this PPN into MPN 410-3 using NPT/EPT 404. MPN 410-3 specifies the base address of page frame 402-5 in terms of a machine address. Page frame 402-5 includes the memory location for the memory access. The actual machine address (MA) 402-6 for the memory access is determined by adding the offset 406-3 to MPN 410-3.
FIG. 2C illustrates in greater detail how the MMU 450 uses the NPT or EPT 404, according to one configuration, to perform a host translation, such as the host translations 409-1, 409-2 and 409-3, translating from PPN 408 to MPN 410. FIG. 2C shows a 4-level structure for NPT/EPT 404, although structures having different numbers of levels are also possible. A person of skill in the art will understand other possible structures and their use, based on existing literature, including, in particular, relevant literature from Intel and AMD. Thus, NPT/EPT 404 comprises a PML4 table 404-1, a page directory pointer table 404-3, a page directory 404-5 and a page table 404-7. At the same time, guest physical address 408A comprises an upper portion 408-1 that is not used for translating to MPN, a PML4 value 408-2, a directory pointer value 408-3, a directory value 408-4, a table value 408-5 and an offset value 408-6. PPN 408 comprises the PML4 value 408-2, the directory pointer value 408-3, the directory value 408-4 and the table value 408-5. Along with NPT/EPT 404, Virtual Machine Control Structure (VMCS) 413 is also maintained by VMM 300. VMCS 413 includes EPT PTR 413-1, which specifies a machine base address for PML4 table 404-1. The PML4 value 408-2 is then used as an index into PML4 table 404-1 to select PML4 table entry 404-2. The entry 404-2 specifies a machine base address for page directory pointer table 404-3. The directory pointer value 408-3 is then used as an index into page directory pointer table 404-3 to select page directory pointer table entry 404-4. Entry 404-4 specifies the machine base address for page directory 404-5. The directory value 408-4 is then used as an index into page directory 404-5 to select page directory entry 404-6. The entry 404-6 specifies a machine base address for page table 404-7. The table value 408-5 is then used as an index into page table 404-7 to select page table entry 404-8. Entry 404-8 specifies MPN 410 corresponding to PPN 408.
As mentioned above, MMU 450 generally stores recently used mappings related to guest page table 402 and NPT/EPT 404 in TLB 454 and in paging structure caches 456 to speed up subsequent memory accesses. Different types of mappings may be stored in TLB 454 and caches 456, as described in existing literature, including, in particular, relevant literature from Intel and AMD. For example, recent mappings from LPN 406 to PPN 408 and recent mappings from LPN 406 to MPN 410 may be stored in TLB 454, while recent mappings from PPN 408 to MPN 410 and recent mappings from PML4 value 408-2 to the contents of PML4 table entry 404-2 may be stored in caches 456. If the guest OS 220 makes changes to guest page table 402 and/or the VMM 300 makes changes to NPT/EPT 404, one or more of the mappings stored in TLB 454 and caches 456 may become stale relative to the corresponding mappings in guest page table 402 and/or NPT/EPT 404. Inconsistencies can arise between the mappings in guest page table 402 and NPT/EPT 404 on one hand and the cached mappings in TLB 454 and caches 456 on the other hand. Such inconsistencies can give rise to non-determinism. Software generally cannot determine exactly which mappings are stored in TLB 454 and caches 456 because mappings can be stored and/or evicted by unpredictable means. For example, mappings can be evicted from TLB 454 due to capacity evictions, System Management Interrupts and speculative TLB prefetches. Thus, the mapping used for a memory access can depend on whether a particular mapping has been stored or evicted from TLB 454 or caches 456. Suppose for example, MMU 450 stores a mapping from a first LPN to a first MPN in TLB 454, based on the mappings in guest page table 402 and NPT/EPT 404. Next, suppose that guest OS 220 changes guest page table 402, so that the first LPN should now map to a second MPN. Suppose next that there is a memory access to the first LPN before any TLB flush (or relevant TLB invalidation). The mapping used by MMU 450 for this memory access to the first LPN will depend on whether or not the mapping from the first LPN to the first MPN has been evicted from TLB 454. If the mapping has not been evicted, then MMU 450 will generally map the first LPN to the first MPN based on the cached mapping, while, if the mapping has been evicted, the MMU 450 will walk the guest page table 402 and determine that the first LPN should map to the second MPN.
The VMM 300 can eliminate any possible non-determinism resulting from changes it makes to NPT/EPT 404 by flushing the TLB 454 and/or the caches 456, and/or by invalidating entries in the TLB 454 and/or the caches 456. A person of skill in the art will understand how to do this, based on existing literature, including, in particular, relevant literature from Intel and AMD.
In some existing virtualized computer systems, the VMM 300 can also eliminate any possible non-determinism resulting from changes the guest OS 220 makes to the guest page table 402. In existing virtualization products from VMware, for example, the VMM 300 can place traces on all physical memory pages that constitute the guest page table 402. Traces are described in earlier patents owned by VMware. If the guest OS 220 attempts to write to the guest page table 402, the VMM 300 is activated and alerted to the attempted write. The VMM 300 may allow the attempted write to take place, but then the VMM 300 can also eliminate any possible non-determinism by flushing the TLB 454 and/or the caches 456, and/or by invalidating appropriate entries in the TLB 454 and/or the caches 456.
However, to fully take advantage of efficiencies of the modern CPUs described above, the VMM 300 preferably does not place traces on the physical memory pages containing the guest page table 402. Instead, the VMM 300 should allow the guest OS 220 to write to the guest page table 402, without any such traces. In this case, however, the VMM 300 generally cannot eliminate all possible non-determinism resulting from changes to the guest page table 402 by the guest OS 220.

This patent is subject to a terminal disclaimer.

Synchronizing a translation lookaside buffer with page tables


To provide a control circuit of a step-down DC-DC converter, a step-down DC-DC converter and a control method thereof which can prevent overshoot and production of a through current flowing to a main switching transistor and a synchronous rectifier transistor by adopting a simple circuit configuration. The control circuit of the step-down DC-DC converter in which a main switching transistor M0 is constituted of a NMOS transistor has a MOS transistor M2 connected between a gate of the main switching transistor M0 and a ground potential and is operable to become conductive in response to an OFF command from the main switching transistor M0.

1. Field
The disclosure relates to a control circuit for a step-down DC-DC converter, a step-down converter, and a control method thereof. More particularly, it relates to a step-down DC-DC converter in which a main switching transistor includes an NMOS transistor, a control circuit for the step-down DC-DC converter and a control method of the step-down DC-DC converter.
2. Description of Related Art
In the technology disclosed in Japanese Laid-open Patent Publication No. 2002-084741, a series circuit including a resistor 103, a diode D101 and a speed-up capacitor C102 is connected in parallel with a voltage dividing resistor R101 at an output terminal side of a resistor voltage dividing circuit. At the stage when a terminal voltage of resistor R101 reaches or exceeds 1 Vf required for turning on the above diode R101 after start-up, the diode D101 is turned on to thereby start charging the speed-up capacitor C102. The charging voltage of the speed-up capacitor C102 at this time is at most equal to the difference between the terminal voltage of resistor R101 during a voltage stabilizing operation and the 1 Vf, so that the speed-up capacitor C102 is gradually charged even if its capacitance is small. As a result, a change in the voltage division ratio of the resistor voltage dividing circuit is also carried out gradually, thereby preventing output voltage overshoot.
Japanese Laid-open Patent Publication No. 2005-174351 discloses a technology for preventing overshooting and undershooting.
However, the technology described in Japanese Laid-open Patent Publication No. 2002-084741 requires the provision of one resistor element, two diodes and one capacitative element at the exterior, which inevitably increases circuit size. Also, in the event a main switching transistor is constituted of a NMOS transistor and a synchronous rectifier transistor is employed, the OFF timing of the main switching transistor is delayed. As a result, the main switching transistor and the synchronous rectifier transistor become conductive at the same time so that a through current flows therethrough. As a result, the main switching transistor and the synchronous rectifier transistor are likely to be damaged.

Control circuit for step-down DC-DC converter, step-down DC-DC converter and control method thereof


Discharging of used printing presses is executed in a narrow space of a mimeograph printing machine body, both simply and cheaply. A pair of rollers convey a used printing press peeled off from a plate cylinder. A press receiving plate swings by 180.degree. around an axis. It receives the printing press conveyed by the pair of rollers at a first position thereof and further conveys the same by its swinging activity toward a second position. A discharge box collects and allows piling of the used printing presses conveyed by the press receiving plate. It is disposed at the end of the conveying path and below the second position of the press receiving plate. The press receiving plate thereby performs both swinging activity around the axis to convey the used printing presses toward the discharge box and compresses the same to increase the number of the printing presses to be discharged therein.

1. Field of the Invention
The present invention relates to a discharge apparatus for discharging printing presses from a plate cylinder disposed in a mimeograph printing machine after a predetermined number of printings are completed based on each of the printing press.
2. Description of the Related Art
A conventional discharge apparatus for discharging a printing press, for example that described in Japanese laid open utility model publication number 204765/1986, needs a rubber roller for peeling off a used printing press wrapped around a plate cylinder, a pair of conveying rollers for conveying the printing press peeled off by the rubber rollers toward a discharge box installed in a section of a mimeograph printing machine and a rubber belt apparatus disposed between the rubber roller and the pair of conveying rollers for conveying the printing presses, so that a large number of parts are needed in the apparatus for conveying the printing presses, and both the scale and the cost of the printing press conveying apparatus increases.
Another conventional discharge apparatus for discharging a printing press, for example that described in Japanese laid open patent publication number 278928/1991, needs a pair of compression spring members, each connected to a pressure plate at opposite edges thereof, for exerting a pressure by the pressure plate on the printing press collected in the discharge box and needs several mechanisms for reciprocating the pressure plate, either in cooperation with or against, the compressing springs.
In addition, the conventional compressing apparatus for a printing press also needs a sensor and an actuator beside the pressure plate for sensing a filling of the discharge box with the printing presses collected therein, so that many parts are needed for the discharge apparatus.
Further, the conventional pressure plate for compressing the printing presses collected in the discharge box returns to a start position soon after its execution of compressing the printing presses, whereby incomplete compressing of the printing presses occurs. Fewer of the printing presses can be collected in the discharge box because they are insufficiently compacted.
Another conventional discharge apparatus for discharging a printing press has a receiving plate which is pivotably mounted by a shaft fixed to a machine body and disposed in a printing press conveying path for receiving the printing presses peeled off from the plate cylinder It can swing by 90.degree. around the shaft after receiving the printing press, to position in a direction perpendicular to that of the printing press receiving position. But it does not disclose the conveying in the same direction as that of the receiving of the printing press, and the compressing of the printing presses.

Printing press discharge apparatus for mimeograph printing machine


Extremely advanced technology for scrambling an optical signal based on quantum mechanical fluctuation is used to provide a highly reliable optical communication method which can invalidate illicit activities such as wire-tapping, a system, and a laser oscillator which is used in the method and system. A transmitter side generates laser light, simultaneously oscillated at a plurality of wavelengths, the total number of generated photons being constant, and transmits a signal light comprising data which has been added to the light of the plurality of wavelengths; and at a receiving side, light, simultaneously oscillated at the plurality of wavelengths, is selected from the signal light, and the data is demodulated.

1. Field of the Invention
The present invention relates to a laser oscillator and an optical communication method and system. The invention specifically relates to technology for scrambling optical signals, which can be used in a highly reliable optical communication system which invalidates illicit activities such as wire-tapping.
2. Description of the Related Art
In an optical communication system using optical fiber as a transmission medium, the communication can be tapped in the same manner as electrical communications using electrical wires by locally bending the optical fiber so that the mode of transmitting along the optical fiber is easily converted to an radiation mode, thereby enabling the light which is being transmitted in the optical fiber to be extracted to the outside. Furthermore, a communication system using spatial light propagation can easily be tapped by providing an optical receiver in the same manner as radio communications.
When the tapped signal can be demodulated, even in a case where the data has been enciphered, the possibility remains that the data can be theoretically deciphered.
For this reason, a desirable communication method is one in which it is difficult to demodulate a tapped signal. One conventional proposal for such a communication method utilizes quantum-mechanical fluctuations which cannot be artificially reproduced, such as the irregularity (chaotic nature) of a laser oscillator.
For example, in one communication method, laser light having chaotic fluctuation is used as the carrier, which data is added to and transmitted, and a part of the signal light transmitted is input a laser resonator on the receiving side so that the laser resonator can perform synchronous oscillation, whereby the carrier component is extracted and the data is subsequently demodulated. According to this method, without the aforementioned special means for extracting the carrier component, a signal detected by a conventional communication method for directly detecting ordinary signal light would always be distorted, making it impossible to demodulate the data.
When extracting the carrier component by inputting signal light to a laser resonator and performing synchronous oscillation, the light carrier frequency and the oscillating frequency of the laser resonator must be aligned with high precision. However, the optical frequency of infrared light used in optical communication is approximately 190 THz, which is much higher than the frequency of ordinary electrical and microwave communications (several GHz). Consequently, a large amount of change in the oscillating frequency is caused by fluctuation of the laser resonator (e.g. thermal and mechanical fluctuation of the resonator length). Since fluctuation reflects changes in the physical properties of the laser resonator, such as change in the refractive index, it has a wide band of components.
In attempting to inject laser light into another laser resonator and perform synchronous oscillation, the resonant frequency of the laser resonator must be aligned with great precision to the light frequency of the injected light.
However, the laser resonator attempting the synchronous oscillation has fluctuation in its own oscillating frequency similar to that of the other laser resonator. As a result, it is impossible to guarantee that the resonant frequency of the laser resonator attempting the synchronous oscillation will remain within the frequency bandwidth of the other laser resonator for a long period of time.
Furthermore, when the person performing the tapping has means for demodulating the signal obtained by synchronous oscillation as described above, conventional methods offer no physical means of stopping him from demodulating the tapped signal.

Laser oscillator, optical communication method and system

Nippon Telegraph and Telephone Corporation


A light-emission control switch transistor and a threshold compensation switch transistor are transistors having different conductivity types. Gate potentials at the light-emission control switch transistor and the threshold compensation switch transistor are controlled using a first control signal. A gate potential at the data signal switch transistor is controlled using a second control signal. A control circuit selects rows sequentially. in a selected one of the rows, the light-emission control switch transistor is maintained off, the threshold compensation switch transistor is maintained on, and the data signal switch transistor is maintained off in a first period. In the selected row, the light-emission control switch transistor is maintained on, the threshold compensation switch transistor is maintained off, and the data signal switch transistor is maintained on in a second period after the first period.

The present disclosure relates to a display device.
An organic light-emitting diode (OLED) element is a current-driven spontaneous light-emitting element. This produces advantages in terms of eliminating the need for backlight, obtaining low power consumption, a wide viewing angle, and a high contrast ratio, etc., so that it is expected to be used in development of flat panel displays.
An OLED display device of active matrix type includes a transistor for selecting a pixel and a driving transistor for supplying a current to the pixel. The transistors in the OLED display device are generally thin film transistors (TFTs), and low temperature polysilicon (LTPS) TFTs are widely used.
The TFT has fluctuation in threshold voltage or charge mobility. As the driving transistor determines the light emission intensity of the OLED display device, such fluctuation in electrical characteristics causes a problem. In response to this, the OLED display device generally used is provided with a compensation circuit for compensating for fluctuation or change in threshold voltage for the driving transistor.
For example, a residual image may be caused on the OLED display device and this phenomenon is called image retention. If a black-and-white checkered pattern is displayed for a particular period of time and then an intermediate tone is intended to be displayed on an entire screen, a residual image of the checkered pattern in a different tone is displayed for a while, for example.
This results from history effect produced by the driving transistor. The history effect means a phenomenon that a difference is caused between a drain current determined when a gate-to-source voltage changes from a high voltage to a low voltage and a drain current determined when the gate-to-source voltage changes from a low voltage to a high voltage.
Specifically, as a difference is caused between the drain current determined by switching from black to an intermediate tone and the drain current determined by switching from white to an intermediate tone, the light-emission intensity of the OLED display device is changed. This difference in the drain current lasts for several frames or more to become visually recognizable as the residual image. Such behavior of the drain current is called current transient response characteristics due to the history effect.

Wuhan Tianma Micro-Electronics Co., Ltd.


A mobile phone is provided which is capable of improving security of personal data of each user when one mobile phone is commonly used by a plurality of users. The mobile phone proper is commonly used by a plurality of users and holds personal data of only a user who logged on with the user's exclusive information attachment being connected to the mobile phone proper, and on the other hand, when the user logs off, moves and saves personal data of the user into the user's exclusive information attachment. In the log-on operations, the mobile phone proper, when a new user has not been registered therein, since the mobile phone proper is in an available state, registers the new user therein and moves personal data of the new user from the information attachment and holds the data. In the log-off operations, the mobile phone proper, when the user has been registered therein and personal data of the user has been held therein, cancels the registration of the user and moves the personal data of the user from the mobile phone proper into the information attachment.

1. Field of the Invention
The present invention relates to a mobile phone, a personal data managing method, and a personal data managing control program, and more particularly to the mobile phone which is suitably employed when the mobile phone is used commonly by a plurality of users, and the personal data managing method for managing the personal data to be employed in the mobile phone, and the personal data managing control program to be used in the mobile phone.
The present application claims priority of Japanese Patent Application No. 2004-115406 filed on Apr. 9, 2004, which is hereby incorporated by reference.
2. Description of the Related Art
In ordinary cases, a mobile phone is manufactured on a premise that one mobile phone is used by one user, however, in some cases, the one mobile phone is commonly used by a plurality of users in a workplace, family, or a like. In this case, even if personal data of one user is stored in the mobile phone and is seen by other users, conventionally, it does not present a problem from a privacy viewpoint since contents of the personal data are a telephone directory or a like at the most. However, in recent years, a mobile phone has become multifunctional and is provided with various functions including a scheduler, a mailer, or a like, in many cases. As a result, personal data stored in the mobile phone is diversified and, therefore, it is difficult for each user to manage such personal data stored in the mobile phone according to a rule made by each user. For example, when one mobile phone is commonly used by a plurality of employees in a workplace and one employee takes the mobile phone out for a business trip for a short time, it is impossible that personal data stored in a presently-available mobile phone is separated for every user, thus causing great inconvenience. Moreover, since personal data of a user can be easily referenced or manipulated by an other user, a problem from viewpoints of privacy among users and of security of personal data occurs. Therefore, a mobile phone having succeeded in solving these problems is proposed.
One example of a conventional method for setting an environment in which a speech terminal is used is disclosed in Japanese Patent Application Laid-open No. 2000-201234 (page 1, FIG. 2) in which, by making a portable memory (mobile phone card) of the speech terminal save a user's most suitable setting condition for an environment in which a device can be used and by making the speech terminal read out the setting information when the speech terminal is operated, the terminal can be operated by any speech terminal on the same setting conditions at any time.
Similarly, a portable communication terminal is disclosed in Japanese Patent application Laid-open No. 2004-040595 (Abstract, FIG. 2) in which management information in which user data of a plurality of users and a PIN (Personal Identification Number) number set by each user is stored in a storing section and user data corresponding to the PIN number input by a user's operation of an operating inputting section is read out from the storing section and the read user data is displayed on a displaying section. By configuring as above, even when one portable communication terminal is commonly used by a plurality of users, data of each of the plurality of users can be independently held and managed.
Moreover, another portable communication terminal is disclosed in Japanese Patent Application Laid-open No. Hei 11-215231 (Abstract, FIG. 1) in which the portable communication terminal has a personal information storing section that stores, at least, personal identification codes and PIN (Personal Identification Number) codes and a compacted number storing section provided on an individual basis that stores a compacted number table and compacted numbers serving as user's information collectively in its compacted number storing section. When the personal identification code and PIN code both being input by users' specified operations are authenticated by a personal identification section, use of the compacted number table prepared on an individual basis is allowed.
However, the conventional technology as described above has following problems. That is, in the case of the conventional method for setting an environment in which a speech terminal is used which is disclosed in the Japanese Patent Application Laid-open No. 2000-201234, if a third party fraudulently obtains the mobile phone card, data stored in the mobile phone card is referenced to by another mobile phone, causing problems in terms of privacy among users and security of personal data.
Also, in the case of the portable communication phone disclosed in Japanese Patent application Laid-open No. 2004-040595, since data of all users is stored collectively, the same problem as in the technology disclosed in Japanese Patent Application Laid-open No. 2000-201234 occurs and, additionally, if an amount of user's data becomes large, a trouble of a failure in storing personal data in the mobile phone proper occurs. Furthermore, in the case of the another portable communication terminal disclosed in Japanese Patent Application Laid-open No. Hei 11-215231, since compacted numbers are stored collectively by the compacted number storing section, the same problem as in the technology disclosed in the Japanese Patent Application Laid-open No. 2004-040595 occurs.

Mobile phone, personal data managing method to be used in same, and personal data managing control program


An isolated or a purified nucleic acid sequence for enhancing expression levels of a protein of interest, in 5′ to 3′ direction, comprises: a cytomegalovirus (CMV) promoter; an eEF-1 intron repeat (eEF-1 IR); and a regular sequence, which comprises: at least one tag element, a fixable linker sequence, wherein the fixable sequence is TEV sequence; and a multiple cloning site (MCS). By means of the array of the specific promoter and eEF-1 IR, the expression and purity of the recombinant protein could be enhanced; wherein eEF-1 IR can reduce the length of vector and assist RNA polymerase II transcription. Besides, TEV sequence of the fixable linker sequence of the regular sequence can remove a tag on recombinant protein; a specific target can be inserted into the multiple cloning site.

1. Field of the Invention
The present invention relates to a nucleic acid sequence segment, especially to a nucleic acid sequence segment that enhances expression of the recombinant protein segments. The present invention also relates to an expression vector, especially to an expression vector that enhances the expression of recombinant protein. The present invention also relates to a kit, especially to the kit comprising the expression vector and an antibody that can detect the expression of the expression vector.
2. Description of the Prior Arts
Since the physical and chemical properties, folding, structure stability, activity, and protein function can be affected by post-translational modification (PTM), PTM is an extremely important mechanism in biological cells. Phosphorylation is one of the most important post-translational modifications of proteins, and it is involved in a variety of different biological signal pathways; phosphorylation not only refers to a PO4 group binding to a protein or other molecules, but also be defined as an organic phosphate group leading into a molecule, therefore, phosphorylation plays a significant rule in biochemistry field because of its complicated regulation mechanism. Protein phosphorylation occurs at a specific amino acid (the major unit of protein) on which the serine is followed by a threonine Phosphorylation occurring on tyrosine is relatively less, and the location on tyrosine is wider because tyrosine can be purified by antibody easily. Phosphorylation and dephosphorylation respectively require specific enzymes to react, such as protein kinase and phosphatase that can react on particular location on amino acid sequence of the protein. Studies estimate that nearly a third of intracellular proteins are phosphorylated, and nearly half of the protein kinases are related to diseases including cancer. Nowadays, the purification and identification of kinase and phosphatase are still difficult because commercial vectors are unavailable for mass production and recombinant protein kinases purification, and commercial recombinant protein kinases still have low purity and other shortcomings.
The secondary structure of alpha-kinase 1 (ALPK1) is: α-helices overlap in N-terminus, and threonine/serine kinases domain in the C-terminus. There is no sequence homology to conventional protein kinases, and they will mainly phosphorylate at α-helices on substrate of the amino acid. However, the functions of ALPK1 gene is rarely known, and commercially available ALPK1 recombinant protein has disadvantages such as poor expression, only 80% purity, less protein concentration for crystallization, incapability of expression in prokaryotic cells, and mini transfection for eukaryotic cells.

Nucleic acid sequence segment for enhancing protein expression


An electric vehicle wherein at least part of a cell unit is provided along an inclined part of a rear dividing wall. A bottom end of the cell unit is positioned lower than the hip point of a passenger. As seen from the vehicle-width direction, motor mounts are positioned so that the top part of the cell unit and part of the motor mounts overlap in the vertical direction of the electric vehicle.

According to an electric vehicle disclosed in Japanese Laid-Open Patent Publication No. 09-309343 (hereinafter referred to as "JP 09-309343 A"), a battery cluster 20 is disposed below a driver seat 6 (FIG. 2).
A vehicle 1000 disclosed in U.S. Patent Application Publication No. 2006/0096797 (hereinafter referred to as "US 2006/0096797 A1") has a first battery pack 1900 that is a 12-volt lead storage battery, and a second battery pack 2000 that is a lithium ion battery ([0032], [0033]). The first battery pack 1900 is disposed in an engine compartment ([0033]). The second battery pack 2000 is provided beneath the base of a front passenger seat 1120 of the vehicle 1000 ([0034]).
According to an electric vehicle disclosed in Japanese Laid-Open Patent Publication No. 08-002405 (hereinafter referred to as "JP 08-002405 A"), a lead battery 25 is disposed above a fuel tank 24, and a sodium-sulfur battery 28 is disposed behind a partition 27 (FIG. 4, FIG. 5, [0011], [0012]).
According to U.S. Patent Application Publication No. 2007/0089442 (hereinafter referred to as "US 2007/0089442 A1"), a rear air-conditioning unit 2000 and a battery pack 3000 are provided on a floor panel 4000 and below an upper back panel 5000 (FIG. 1, [0052]). The battery pack 3000 is substantially in the shape of a rectangular parallelepiped (FIGS. 1 and 2).
According to a vehicle 1 disclosed in U. S. Patent Application Publication No. 2011/0132676 (hereinafter referred to as "US 2011/0132676 A1"), the front side of a battery 12 that supplies electric power to a motor 11 is disposed forwardly of a dash panel 18, and the rear side of the battery 12 is disposed in a tunnel 22 that extends in a longitudinal direction of the vehicle (Abstract, FIGS. 1 and 2).


A two-stroke engine (4) has a throttle motor (22) for driving a throttle valve (20), a fuel injection device (430) disposed in an intake system (18) including a crank chamber (420), and a control unit (24) controlling the throttle motor (22) and the fuel injection device. The two-stroke engine (4) is designed to achieve an engine rotation speed of 4,500 rpm to 7,000 rpm when the throttle valve (20) is fully open. The two-stroke engine (4) is operated with the throttle full open by the control unit (24), and a battery (8) is charged with electric power generated by a generator (6) using the two-stroke engine.

The present invention relates to a two-stroke engine (hereinafter referred to as "2-st engine") mounted on a working machine, and more specifically, to a 2-st engine suitable for hybridizing a working machine and a series hybrid device for a working machine incorporating the same.
Historically, the 2-st engines were excluded from passenger cars under the exhaust gas regulations tightened year by year, and then also excluded from motorcycles (motorbikes), and today, 4-stroke engines (hereinafter, "4-st engines") account for the great majority of engines of passenger cars and motorcycles.
The working machine is not only essentially required to be small and lightweight, but also has various usage environments, and is tilted or reversed in use. The 2-st engine has a simpler mechanism than the 4-st engine. Particularly, a piston valve type 2-st engine has no valve system components in an engine body and is therefore characterized by high reliability, small size, and light weight. Considering the use form of the working machine, the characteristics of the 2-st engine are suitable for the power source of the working machine. For this reason, the 2-st engines continue to be adopted as a power source for working machines, and historically, the 2-st engines for working machines have evolved in combination with a carburetor. Therefore, the current working machines have a power source made up of a 2-st engine incorporating a carburetor.
The exhaust gas regulations are being tightened year by year for working machines as well. However, the developers of the 2-st engines are constantly developing and putting into practical use the techniques overcoming the exhaust gas regulations. A typical example thereof is a stratified scavenging engine (U.S. Pat. No. 6,289,856) and an electronic control device for a carburetor (U.S. Pat. No. 9,255,535). For weight reduction and simplification, the number of sensors mounted on a working machine is limited, and an electric power generated by a generator is mainly used for ignition of a spark plug.
Passenger cars and motorcycles are becoming more electrified so as to comply with recent exhaust gas regulations. In the working machine industry, many motor-driven types are already on the market. Since the working machine is required to be small and lightweight as described above, a large capacity battery cannot be mounted on the working machine. This problem leads to limited working time. In fact, a commercially available electric working machine is unsuitable for long-time use because the battery runs out after being used for about 30 minutes. Particularly since most of the working machines are used outdoors such as in fields and forests where a charging power source cannot be secured, both electrification and hybridization are limited in terms of widespread use.
In passenger cars, a technique has been proposed for mounting a relatively small battery and extending a cruising distance and has already been put into practical use. A system extending a cruising distance uses an engine exclusively for power generation. A typical example is "e-Power" of Nissan Motor Co., Ltd. The e-Power is a series hybrid system charging a battery with a combination of a 4-st engine and a generator for running only with a motor using this battery as an energy source.
The hybrid system requires an engine, a generator, a motor, and a battery, and has a disadvantage of being large and heavy. This disadvantage is fatal for working machines required to be small-sized and lightweight. However, measures against exhaust emissions are an urgent issue even for working machines. Regarding the power source of the working machine, a hybrid device for a working machine is proposed by U.S. Pat. Nos. 6,289,856, 9,255,535, Japanese Unexamined Utility Model Application Publication No. 4(1992)-19184, and Japanese Laid-Open Patent Publication No. 63(1988)-199103. Although it is not clear whether the engines disclosed in Japanese Unexamined Utility Model Application Publication No. 4(1992)-19184 and Japanese Laid-Open Patent Publication Nos. 63(1988)-199103, 2004-166543, and 2020-115 are 2-st engines or 4-st engines, it can be inferred that the inventors of Japanese Unexamined Utility Model Application Publication No. 4(1992)-19184 and Japanese Laid-Open Patent Publication Nos. 63(1988)-199103, 2004-166543, and 2020-115 proposed hybrid devices for working machines on the assumption of a 4-st engine.

Two-stroke engine for working machine and series hybrid device for working machine incorporating the same


A host device is configured to communicate over a network with a storage system. The host device comprises a multi-path input-output (MPIO) driver configured to control delivery of input-output (IO) operations from the host device to the storage system over selected ones of a plurality of paths through the network. The MPIO driver is further configured to send one or more requests to the storage system for data corresponding to performance of one or more switch fabrics in the network, and to receive the data corresponding to the performance of the one or more switch fabrics from the storage system. The MPIO driver is also configured to identify one or more performance issues associated with at least one of the selected ones of the plurality of paths based on the received data, and to manage one or more of the input-output operations responsive to the identified performance issues.

Storage arrays and other types of storage systems are often shared by multiple host devices over a network. Applications running on the host devices each include one or more processes that perform the application functionality. The processes issue input-output (IO) operations for delivery to storage ports of the storage system. The storage ports are typically limited in number and each has limited resources for handling IO operations received from the host devices. Different ones of the host devices can run different applications with varying workloads and associated IO patterns. Such host devices also generate additional IO operations in performing various data services such as replication and migration so as to meet business continuity requirements.
Fibre channels can achieve lossless data transfer by utilizing buffer to buffer credit mechanisms. However, the Fibre channels are not immune to fabric congestion. When fabric congestion occurs, some host device multi-pathing software is not provided with sufficient information about the congestion situation. As a result, host device multi-pathing software is not equipped with necessary information to overcome the congestion.

Array driven fabric performance notifications for multi-pathing devices


A packaging and application unit, including an applicator containing a product capable of becoming soluble or gelling on its surface in contact with a liquid composition, and a reservoir containing the liquid composition. In use, the applicator is placed into contact with the liquid composition through an elastically deformable element which is capable of containing a quantity of the liquid composition, and is capable of selectively passing from a compressed position wherein at least a portion of the surface of the applicator bears on a restoring surface of the deformable element, so as to be in contact with the liquid composition, into a rest position. Passing from the compressed position to the rest position produces the charging of the deformable element with the liquid composition by suction through a charging surface of the deformable element.

1. Field of the Invention
The present invention concerns a packaging and application unit capable of being used, in particular, in the fields of pharmacy, cosmetics, dermatology, hair care and etc. The invention concerns more particularly a device of the type comprising a solid or semi-solid applicator which must be placed into contact with a liquid composition before the application, and capable of becoming soluble or of gelling at its surface which contacted the liquid composition. By way of example, the applied material of the applicator may be a slightly friable lipstick whose surface must be placed into contact with water for example, in order to soften it on its surface, and thus to promote the friability of the lipstick. Again, by way of example, the applicator may be of the "styptic pencil" type used for cauterizing wounds. In the previous example, the applicator contains active water-soluble substances such as mixtures of aluminum and ammonium sulphates which become soluble in the presence of a liquid composition such as water. The invention also applies to the application of a product capable of having both a cosmetic effect and a treatment effect. The cosmetic effect being produced by the applicator itself, and the treatment effect being obtained by a liquid solution with which the applicator is placed into contact. By way of example, this concerns a lipstick that is placed into contact with a treatment composition which prevents the cracking of lips. It may also be a stearate soap of ammonium or potassium, or a tensioning stick, for example, of polyvinyl alcohol (PVA) capable of erasing wrinkles. It may also be a compound such as an emollient which may not be introduced into the stick during its manufacture.
2. Discussion of the Background
European Patent 612 488 describes an applicator comprising a reservoir containing a product to be applied, a cap intended to close the reservoir and an applicator holder supporting a deformable element, for applying the product, made of foam or an elastomer of low hardness. The deformable element has asperities on its surface and is provided with the ability to regain its original shape.
The reservoir for the product is delimited by a capillary end fitting in the shape of a glove finger having a bottom provided with a seat pierced by at least one capillary opening against which the deformable element is applied and deformed in its position when the reservoir is closed by the cap.


Bag tying machine with a pair of pivoted arms (1,2), a pair of leaf springs (3) between the two arms (1,2) to form a first abutment, and a second abutment (5), preferably formed from a pair of rollers. In use, the open neck of a bag is passed between the arms (1,2) and is gathered together by the leaf springs (3). The gathered together neck of the bag is pushed onto an adhesive tape which is wrapped around the neck of the bag as this passes through the second abutment. The downstream ends of the arms (1,2) are urged together by pneumatic cylinders (6). These are advantageously controlled by a variable pressure controller (9).

Our earlier patent specification EP-A-0128687 describes a bag sealing machine for gathering together the neck of a filled bag and then forming an adhesive tape tie around the gathered together neck. Such machines are widely used, particular in the bakery industry. Typically such machines include a pair of arms which are pivoted at one end and urged together at their opposite ends by compression springs. The open end of a filled bag is urged between the pair of pivoted arms and gathered together by a follow-up member travelling faster than the bag along the pivoted arms. As described in EP-A-0128687 the gathered together neck of the bag is compressed against a first abutment formed by a pair of fixed jaws projecting into the space between the pair of arms, then forced between the jaws onto a piece of adhesive tape and then, together with the piece of adhesive tape forced into contact with a second abutment formed by a second pair of jaws which wraps the adhesive tape around the gathered together neck of the bag and onto itself to complete the tie.
Over the years the speed of operation of such bag sealing machines has increased significantly and one problem that can occur is that the neck of the bag can be torn as it is pushed against the first set of jaws. This is obviously unsatisfactory. The likelihood of the neck being torn depends partly on the speed of throughput of the filled bag, partly on the gauge of the plastic used to form the bags and partly on the weight of the contents of the bag. It also appears that the overall shape of the bag may also influence this because recently attempts have been made to use a gusseted bag for loaves of bread to give a more rectangular appearance to the filled bag and, when operating the bag sealers at high speed with such bags has led to unsatisfactory results.


A foldable fuel cooker is provided including a central member and a plurality of legs pivotally connected to central member via pipes mounted thereon. An inlet tube is connected to the central member and extends therefrom to a central extent of one of the legs. A brace is mounted on one of the legs for preventing the inlet tube from being inadvertently removed.

1. Field of the Invention
The present invention relates to burner tripods and more particularly pertains to a new folding propane cooker with inlet support brace for providing a propane cooker that has improved air ventilation, more robust hinged couplings, and an improved inlet which is less susceptible to being inadvertently detached.
2. Description of the Prior Art
The use of burner tripods is known in the prior art. More specifically, burner tripods heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art burner tripods include U.S. Pat. No. 5,423,308; U.S. Pat. No. 5,333,540; U.S. Pat. No. 4,949,701; U.S. Pat. No. 4,393,857; U.S. Pat. No. 4,210,118; and U.S. Pat. No. Des 256,316.
The prior art burner tripods further includes that which is shown in FIGS. 1-3. Such tripod includes a cylindrical central member with two legs pivotally mounted thereon and a third leg fixed with respect to the central member. The foregoing pivotal coupling is accomplished by way of an inferior compression fitting. The central member has a height which is approximately equal to that of the inboard extents of the legs. As shown in FIG. 3, a bottom face of the tripod has a bottom face with a washer welded therein for reasons that will soon become apparent. The prior art tripod further includes an inlet pipe which is constructed from a bendable brake line. As shown in FIG. 3, the brake line has a vertically oriented inboard portion welded within an aperture of the washer and having a grease zert mounted to a top end thereof. As such, ventilation is precluded. The prior art tripod further includes a horizontally oriented outboard portion spaced below the bottom face of the central member and extending therefrom in an adjacent spaced relationship with the fixed leg. As shown in FIGS. 1 & 2, the horizontally oriented outboard portion extends past an outboard extent of the fixed leg whereat a coupler is positioned for connecting with a gas supply hose. The inlet tube of the prior art tripod is highly susceptible to being broken off. The prior art device is constructed from a stainless metal.
In these respects, the folding propane cooker with inlet support brace according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of providing a propane cooker that has improved air ventilation, more robust hinged couplings, and an improved inlet which is less susceptible to being inadvertently detached.

Folding propane cooker with inlet support brace