A blowout preventer is provided with an improved sealing assembly for sealing engagement with a pipe extending through the blowout preventer into a well bore. The sealing assembly includes an elastomeric seal and a plurality of circumferentially spaced metal inserts within the seal for substantially minimizing or preventing extrusion of the seal under high fluid pressure. The BOP be reliably used for sealing engagement with pipes of varying diameters. Each insert has a substantially I-shaped configuration with an upper flange, a lower flange, and a rib fixedly interconnecting the flanges. A slot is provided within at least one of the flanges and forms a cavity for receiving a male interconnecting member extending circumferentially from an adjacent one of the inserts, such that the circumferentially spaced inserts are interconnected to minimize extrusion gaps between the inserts and to better enable the sealing assembly to form a positive seal with the pipe.

1. Field of the Invention
The present invention relates to blowout preventors commonly used in oil and gas drilling operations to seal fluids within the well bore. More particularly, the present invention relates to a sealing or packing element of a ram-type blowout preventer with improved metal inserts to prevent extrusion of the sealing element.
2. Description of the Background
Ram-type blowout preventers or BOPs are commonly provided on wellheads for sealing with pipe and thereby retaining high pressure within the well bore. The BOP commonly employs a pair of semi-circular ram rubbers, each of which move simultaneously for sealing enegagment with the pipe in response to application of high fluid pressure to the opposing ram cylinders. In the past decade, increased emphasis has been placed upon BOPs which are capable with sealing with variable diameter pipe, thereby minimizing the number of blowout preventors required at the drilling site.
Since at least the 1930's, those skilled in the art of blowout preventers have recognized the desirability of utilizing metal plates or segments which may be at least partially embedded within the ram rubber to increase the integrity of the seal under high pressure These metal segments are typically arranged circumferentially about each semi-circular ram rubber, as disclosed in U.S. Pat. No. 2,035,925, and inherently move closer as the BOP rams move radially inward to engage the pipe. U.S. Pat. No. 3,434,729 discloses a BOP ram assembly, and teaches the use of metal plates spaced above and below the ram rubber to inhibit the extrusion of rubber under high pressure Although the metal plates as disclosed in the '729 patent have been widely used, many BOP operators prefer the characteristics of BOP sealing elements which include a plurality of circumferentially-spaced metal inserts imbedded within the ram rubber.
BOP metal inserts are preferably provided adjacent both the upper and lower ends of each of the opposing BOP seals. A significant advantage of providing the elements at the lower end of the BOP seal is that the entire BOP sealing assembly may be inverted during an emergency, so that the bottom inserts are now the top inserts and serve to prevent extrusion of the sealing element and thereby retain the high pressure fluid within the well bore. Such metallic inserts functionally are provided in two general types: (1) inserts within the elastomeric sealing material which are adapted for engagement with the pipe which passes through the BOP, and (2) inserts which are not adapted to engage the BOP pipe but only reinforce the elastomeric or rubber seal, so that a layer of the rubber seal is provided between the radially inwardmost surface of the metal inserts and the pipe.
One type of metal inserts for a BOP seal is disclosed in U.S. Pat. No. 3,572,628. The inserts as shown in FIG. 8 of this patent are substantially I-shaped, with the upper and lower flanges of each insert positioned adjacent the upper and lower ends of the BOP sealing element. U.S. Pat. No. 2,609,836 discloses a blowout preventor with "control elements" that are either I-shaped, as shown in FIGS. 13-15, or are cup-shaped, as shown in FIGS. 39-42. One advantage of the cup-shaped control elements is that these elements may interlock. U.S. Pat. No. 3,915,424 discloses anti-extrusion elements which are positioned adjacent the upper and lower surfaces of the BOP seal, and overlap and interlock so that the radially inward-most surface of the elements contacts the pipe. A particular type of interlocking mechanism for anti-extrusion elements of a BOP seal is disclosed in U.S. Pat. No. 3,915,426.
Advantages are obtained by using metal inserts for a BOP seal wherein the upper metal inserts and the lower metal inserts are interconnected, in the manner of the I-beam design discussed above. Compared to separate upper and lower insert designs, less individual components of the seal assembly are used, and the I-beam design also promotes the uniform movement of the inserts toward the pipe. U.S. Pat. No. 3,958,808 discloses I-beam inserts as shown in FIG. 9 with "buttons" to better secure the metal inserts to the elastomeric material of the sealing element. U.S. Pat. No. 4,444,404 discluses a BOP packing element with I-beam metal inserts having "stair-stepped" flanges. U.S. Pat. No. 4,447,037 disclosed another version of I-beam inserts for a BOP seal, with the metal inserts having a configuration as shown in FIGS. 6 and 7 of this patent.
Prior art BOPs have disadvantages which have limited their acceptance in the oil and gas exploration industry. Some of the BOPs employ sealing assemblies which do not include circumferentially spaced metal inserts to minimize extrusion of the sealing material, while other BOPs employ metal plates above and below the rubber sealing element to control extrusion. Of the BOPs which utilize circumferentially spaced metal inserts, the type of inserts which fixedly interconnect an upper insert member to a lower insert member are generally preferred over those which utilize separate upper and lower insert members. BOP sealing inserts which interlock, such that significant extrusions gaps are eliminated between adjacent members, and which uniformly close around the pipe to create a seal are preferred, although such BOP's are generally expensive. Improved techniques are thus required to provide a relatively low cost sealing assembly for a BOP which does not suffer from the disadvantages of the prior art, and which can effectively prevent extrusion of the BOP sealing material.
The disadvantages of the prior art are overcome by the present invention, and an improved blowout preventer, a sealing assembly for a blowout preventer, and metal inserts for the sealing assembly of a blowout preventer are hereinafter disclosed which overcome the disadvantages of prior art BOPs.


A frequency modulated output of a Digital Locked Loop (DLL) is implemented with a Johnson Counter outputting a sample clock and a synchronized digital code at a multiple of the sample clock. The digital code drives a digital-to-analog converter to generate a frequency modulated control signal. The control signal is summed with the center frequency control from the digital locked loop digital filter to provide a frequency modulated center frequency control signal to the DLL oscillator.

1. Field of the Invention
The present invention relates generally to a digital phase locked loop, and in particular to a digital phase locked loop that generates a frequency modulated output clock.
2. Description of the Related Art
Phase locked loops (PLL) have been widely used in communication systems or the like, some frequently appearing in applications such as extracting information from carrier waves or synchronous signals. A phase locked loop is a well-known clock synchronization technique to drive a timing signal, synchronized or locked, to a reference clock signal.
A PLL is a frequency-selective circuit generally containing a phase comparator, a low-pass filter, and a controllable oscillator, whose own output is coupled in a feedback arrangement to one of the phase comparator inputs. When an input or reference clock signal is applied to the PLL, the phase comparator compares the phase of the oscillator output signal to the phase of the reference clock signal and generates an error signal that is related to both the frequency and the phase relationship between the two signals. This error signal is filtered, buffered and applied to the oscillator, thus driving the oscillator output signal frequency in a direction to more closely equate its frequency, to that of the reference clock signal frequency. When the oscillator output frequency is sufficiently close to the reference frequency, usually within a few percent, the PLL will be in a "frequency locked" condition. Next, the phase detector and the feedback nature of the PLL cause the oscillator to substantially align each of the oscillator clock output rising edges to the rising edges of the reference clock signal frequency, with the exception of some small but finite phase difference. This point is called the "zero phase error." While the phases may not be perfectly aligned, their frequencies are sufficiently matched such that the amount of phase difference remains substantially constant, except for the small effects of noise. The self-correcting nature of the PLL thus allows the system to track any small frequency changes of the reference clock signal once it is locked. A frequency divider is often inserted in the feedback loop when the desired output frequency of the oscillator is to be a multiple of the reference clock signal frequency.
In combination with a digital phase detector, fully-digital PLLs usually include a digital loop filter instead of the traditional analog filter, and often include a digitally-controlled oscillator (DCO) instead of a current-controlled oscillator (ICO) or voltage-controlled oscillator (VCO). In theory, these fully digital PLLs have several advantages over their analog counterparts. First, digital logic exhibits much better noise immunity than analog circuitry. Second, analog components are vulnerable to DC offset and drift phenomena that are not present in equivalent digital implementations. Further, the loop dynamics of analog PLLs are quite sensitive to process technology scaling, and therefore require significant design and simulation efforts, whereas the functional behavior of digital logic remains essentially unchanged with scaling, although its parametric behavior does change. Moreover, power dissipation is of extreme concern for portable, battery-powered, computing or communication systems. Thus, Digital PLLs generally enable a relaxation of the power supply voltage requirements of integrated circuits.
As is known in the art, high frequency clock generation circuits such as those used in portable, electronic devices can produce significant levels of electromagnetic interference (EMI). This can be particularly detrimental in portable, wireless communication applications. Consequently, manufacturers of wireless communication devices, such as cell phones, employ various techniques to reduce the EMI produced by such high frequency components. One technique employed to reduce EMI generated by a PLL clock generation circuit is to frequency modulate the oscillator of the PLL by various means. The benefit of frequency modulation is to spread the energy of the output signal over a wider frequency range and thereby effect a reduction in the measured intensity of EMI, as well as its adverse effects on nearby radio receivers.
FIG. 1 is a block diagram of a typical PLL 100 of the prior art using frequency modulation on its output to reduce the circuit's generation of EMI. The PLL 100 includes a phase detector 110 having a first input for the referenced clock signal and a second input for the feedback signal. The output of the phase detector 110 is coupled to the input of a digital filter 120. The output of the digital filter 120 is coupled to a first input of an adder 130, and a second input of adder 130 receives a frequency modulation control signal (fm). The frequency modulation control signal (fm) is generated through a separate oscillation system. The output of adder 130 is coupled to an input of a controllable oscillator 140, which generates an oscillating clock signal on its output. The output of controllable oscillator 140 is also coupled to an input of frequency divider 150. An output of frequency divider 150 is coupled to the second input of phase detector 110. Thus, the output of controllable oscillator 140 is coupled through the frequency divider 150, to operate as the feedback signal to the second input of phase detector 110.
As will be appreciated, if the inherent variations in clock generation systems are non-linear, they may cause the injected frequency modulation signal to shift the average center frequency output of controllable oscillator 140. Without precise synchronization of the reference clock signal and the frequency modulation signal, there may be significant fluctuations in the average clock frequency output of the digital PLL. Moreover, the additional circuitry required to generate the frequency modulation control signal further complicates the overall digital circuitry of the integrated circuit.
For the reasons stated above, and for other reasons which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for an alternative digital locked loop system capable of establishing a digital frequency or phase locked loop output clock having frequency modulation without altering the average system frequency output and with minimal added complexity.
In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced.

This patent is subject to a terminal disclaimer.

Frequency modulated output clock from a digital frequency/phase locked loop


This system for displaying data on a display unit comprising a television screen associated with a videographic memory, the data containing at least one videographic signal and scanning data, a pre-processing unit for reel time programming the output data of the radar, a threshold unit for thresholding the videographic signal from its background noise, and a digitizer circuit for digitizing the videographic signal after thresholding, a compression circuit for space-time compressing the videographic signal after digitization, a transmission device for proprietary serial data transmission of the scanning data, of the compressed videographic signal and of compression data, to the television display assembly unit, which comprises a decompression unit for decompressing the videographic signal and a converter unit for converting the standard of the coordinates of the data contained in this signal, from a polar coordinates into a Cartesian coordinates with the aid of the compression and scanning data, and control device for controlling the contents of the memory in cooperation with an after glow processor, for controlling certain zones of videographic memory according to a mathematical treatment formula, and generating a complete image of the radar output.

The present invention relates to a system for the remote display of output data of at least one radar.
More particularly, this system is adapted to permit the display of output data of a radar on a display unit comprising a television screen associated with a videographic memory.
Systems exist in the art for displaying output data of a radar in which the different outputs of a radar are applied to a display console comprising a conventional readout.
More particularly, the videographic signal output of this radar is connected to the corresponding input of the readout via a coaxial cable or H.F. microwave.
It will be understood that the use of such a cable presents a number of drawbacks as concerns the placement of the different components of the radar unit, the transmission of the signals and ease of the use of the radar unit.

System for the remote display of output data of at least one radar


A method for network adaptation includes receiving, by an adaptation coordinator of a virtual network, a performance measurement generated at a performance checkpoint located in the virtual network. The method also includes generating, by the adaptation coordinator, a first update of a service-specific configuration of the virtual network. The first update includes at least one of a modification of a performance checkpoint configuration, a modification of a Virtual Network Function (VNF) configuration, a modification of a protocol configuration, a modification of a resource allocation input, or a modification of a logical graph. The service-specific configuration includes a configuration of a plurality of logical nodes and a plurality of logical links of the virtual network in accordance with a service-specific data plane logical topology.

Telecommunications networks are constantly evolving to improve revenue generation by incorporating new technologies with improved features and functionality for delivering higher data rates and quality of service, while attempting to maintain or increase cost efficiencies. Thus, network operators have been considering a wide variety of new revenue-generating services, including machine-to-machine (M2M) long-term monitoring and control services. M2M services may include, e.g., traffic monitoring, fleet management, smart metering, environmental monitoring, industrial monitoring and control, etc. The number of M2M devices is expected to grow quickly as more connected device become available to consumers, and as more industries adopt M2M technologies such as sensor networks.

System and method for modifying a service-specific data plane configuration


Treatment fluids employing stabilized heteropolysaccharide-based gels in brines are used as part of gravel packing and combined gravel packing-fracturing operations; a method includes providing a treatment fluid which includes an aqueous brine base, a heteropolysaccharide including one selected from the group consisting of diutan, scleroglucan, and succinoglycan, and a protein present in an amount sufficient to stabilize the heteropolysaccharide and hence minimizing the salting out phenomenon, the method including placing the treatment fluid in a subterranean formation.

The disclosure herein relates to treatment fluids employed in subterranean operations, and more particularly, to the stabilization of heteropolysaccharide-based gels in brine-based treatment fluids as part of subterranean operations, such as gravel packing and combined gravel packing-fracturing operations.
Gravel packing treatments have been used to reduce the migration of unconsolidated formation particulates into a well bore. During gravel packing operations, gravel particulates are generally carried to a well bore by a hydrocarbon or aqueous carrier fluid. The gravel particulates are suspended in a carrier fluid, which may be viscosified, and the carrier fluid is pumped into a well bore in which the gravel pack is to be placed. The carrier fluid may leak off into the subterranean zone and/or return to the surface while the particulates are left in the zone. The resultant gravel pack may act as a filter to separate formation sands from produced fluids while permitting the produced fluids to flow into the well bore. A portion of the gravel may be coated with tackifying agents, among other things, to further help control the migration of formation fines. Typically, gravel pack operations involve placing a gravel pack screen in the well bore and packing the surrounding annulus between the screen and the well bore with gravel designed to prevent the passage of formation sands through the pack. Such gravel packs may be used to stabilize the formation while causing minimal impairment to well productivity.
For gravel packing operations requiring higher densities, heteropolysaccharide-based viscosifiers, such as diutan gels are commonly employed in brine-based fluids. However, when diutan gels are prepared in high salt concentration brines (e.g., brine density greater than about 10 ppg such as, but not limited to, sodium bromide, calcium bromide, calcium chloride, cesium formate, cesium acetate, potassium formate and potassium acetate) and temperatures above about 180° F. (about 82° C.), diutan exhibits a salting-out effect at pH less than about 3. The salting-out effect is believed to be a cumulative effect of the following factors: temperature, brine density, concentration of diutan and pH. Hence, to maintain the requisite rheological properties of the treatment fluids, among the required considerations are a careful selection of salts and salt concentrations. In general, the salting-out effect trends along the Hofmeister series observed for proteins. Thus, bromides and iodides relative to chlorides are generally more favorable for preventing heteropolysaccharide salting-out. Iodides in particular, while providing good prevention of salting out, are not practical in typical gravel packing operations due to the prohibitive cost of iodide salts. Thus, the salting-out effect tends to limit the brine types, brine densities, and temperatures in which the treatment fluids can be prepared and used.
Other solutions to prevent or reduce salting-out include the use of urea, which has also not proved to be commercially viable. Other avenues employing, for example, xanthan-based gelling agents in lieu of diutan suffer from incompatibilities with crosslinkers used in xanthan-based systems as well as temperature limitations in operation.

Treatment fluids comprising stabilized heteropolysaccharides and related methods


A network arrangemen includes a receiving computer connected over a network to plural sending computers. A first session is established between the receiving computer and a first of the plural sending computers, where the first session involves providing data of a peripheral device attached to the receiving computer to the first sending computer, and where the data of the peripheral device is provided to a first device driver of the peripheral device in the first sending computer. A second session is established between the receiving computer and a second of the plural sending computers, where the second session involves providing the data of the peripheral device attached to the receiving computer to the second sending computer, and where the data of the peripheral device is provided to a second device driver of the peripheral device in the second sending computer.

Many enterprises are transitioning to a network arrangement in which computing resources of central servers are provided to local computers at which users are located. The computing resources (e.g., software applications, processing resources, storage resources, etc.) that are centralized at one or more central servers can be selectively allocated to a session established by a user at a local computer.
Protocols arc provided to enable a user at a local computer to access and share the desktop of a remote computer (e.g., a central server) over a computer network. One such protocol is the Remote Desktop Protocol (RDP), as provided by Microsoft Corporation, to provide remote display and input capabilities over network connections. Another protocol that can be used is the Remote Graphics Software (RGS) protocol from the Hewlett Packard Co. RGS is designed to take full advantage of the computer and graphics resources of a remote computer to deliver interactive remote access at the local computer. The desktop video data of the remote computer is transmitted over the network to the local computer, which displays the desktop video data locally in a window at the local computer. RGS is designed to provide fast capture, compression, and transmission of a desktop video data over a network. RGS also allows audio data to be sent from the remote computer to the local computer for output on an audio device of the local computer. RGS also captures user keyboard and mouse inputs at the local computer, and sends the keyboard and mouse inputs to the remote computer for processing by the operating system of the remote computer, and by applications running on the remote computer. RGS also allows data of other peripheral devices (e.g., such as storage devices) to be communicated from the local computer to the remote computer.
When connecting a local computer to multiple remote computers, multiple duplicate peripheral devices may have to be attached to the local computer for use with the corresponding remote computers. Use of duplicate peripheral devices increases the number of hardware devices that have to be attached to the local computer, and can lead to increased complexity and costs.

Selectively communicating data of a peripheral device to plural sending computers

Hewlett-Packard Development Company, L.P.


A VVA apparatus includes a control shaft arranged rotatable in accordance with the engine operating conditions, an alteration mechanism for changing a lift amount and an operating angle of an engine valve in accordance with rotation of the control shaft, and a drive mechanism for rotating the control shaft and including an electric motor and a reduction mechanism. The reduction mechanism has a reduction ratio set to be larger when the valve is under small lift-amount and operating-angle control than when the valve is under large lift-amount and operating-angle control.

The present invention relates to a variable-valve-actuation (VVA) apparatus for an internal combustion engine, which can vary at least the operating angle of engine valves such as an intake valve and an exhaust valve in accordance with engine operating conditions.
Typically, the VVA apparatus applied to intake valves comprises a crank cam arranged at the outer periphery of a driving shaft that rotates in synchronism with a crankshaft and having an axis eccentric to an axis of the driving shaft, and a valve operating (VO) cam to which torque of the crank cam is transmitted through a transmission mechanism to have a cam face coming in slide contact with the top face of a valve lifter arranged at the upper end of the intake valve for opening operation thereof against a biasing force of a valve spring.
The transmission mechanism includes a rocker arm disposed above the VO cam and swingably supported to a control shaft, a crank arm having an annular first end engaged on the outer peripheral surface of the crank cam and a second end rotatably connected to a first arm of the rocker arm through a pin, and a link rod having a first end rotatably connected to a second arm of the rocker arm through a pin and a second end rotatably connected to a cam nose of the VO cam through a pin.
The control shaft is driven, for example, by an electric motor through a worm gear or reduction mechanism provided to a driving shaft of the motor. Fixed on the outer peripheral surface of the control shaft is a control cam having an axis eccentric to an axis of the control shaft by a predetermined amount and rotatably fitted in a support hole formed substantially in the center of the rocker arm. The control cam changes a rocking fulcrum of the rocker arm in accordance with the rotated position to change the position of contact of the cam face of the VO cam with respect to the top face of the valve lifter, carrying out variable control of the lift amount and operating angle of the intake valve.
Specifically, when the engine operating conditions are in the low-rotation range, for example, the control shaft is rotated in one direction through the motor to rotate the control cam in the same direction, moving the rocking fulcrum of the rocker arm in the direction of separating from the driving shaft. Then, a pivotal point of the rocker arm with the link rod is moved upward to draw up the cam nose of the VO cam, moving the position of contact of the VO cam with respect to the top face of the valve lifter in the direction of separating from a lift portion of the VO cam. Thus, the intake valve is controlled to minimize the lift amount and the operating angle
On the other hand, when the engine operating conditions pass from the low-rotation range to the high-rotation range, the control shaft is rotated in another direction by the motor to rotate the control cam in the same direction, moving the rocking fulcrum of the rocker arm in the direction of approaching the driving shaft. Then, the cam nose of the VO cam is pushed downward by the link rod, etc. to move the position of contact of the VO cam with respect to the top face of the valve lifter to the lift portion of the VO cam. Thus, the intake valve is controlled to increase the lift amount and the operating angle.
Therefore, outstanding engine performance such as improved fuel consumption, increased engine output, or the like can be obtained in accordance with the engine operating conditions.
With the VVA apparatus, however, referring to FIG. 8, the worm gear arranged to reduce rotation of the motor for control of the control shaft has a reduction ratio which is always constant regardless of the control conditions of the valve-lift amount and the operating angle as shown by broken line. Thus, under small valve-lift and operating-angle control which corresponds to a control area in the ordinary driving range or practical range of the vehicle, the reduction ratio is smaller, leading to greater power consumption of the motor.
Specifically, the reduction ratio obtained from the angular velocities of the driving shaft of the motor and the control shaft corresponds to a torque ratio of the motor, which is proportional to current supplied thereto. Therefore, under small valve-lift and operating-angle control, the reduction ratio is not increased and thus smaller, leading to greater torque of the motor for rotating the control shaft. This increases power consumption during ordinary driving of the vehicle, resulting in a harmful effect on fuel consumption of the internal combustion engine which also serves to drive accessories such as an alternator.
Further, if power supplied to the motor is smaller due to reduction in storage amount of a battery for supplying power to the motor, a technical problem can occur such as deterioration of the rotation-ability of the motor in the ordinary driving range of the vehicle.
Furthermore, since the reduction ratio is not decreased and thus constant during the transition from small valve lift to large valve lift, which occurs at quick acceleration of the vehicle and the like, the total number of revolutions of the motor required for this transition cannot be reduced, causing longer transition time, resulting in possible lowering of the switching responsivity from small valve lift to large valve lift.

Variable-valve-actuation apparatus for internal combustion engine


An electrophotographic photoreceptor using a non-contact type charging process has a creep value CIτ of is 2.70% or more, preferably 3.00% or more, and a Vickers hardness (HV) at its surface of 20≦HV≦25 in a case where a maximum indenting load of 30 mN is loaded to the surface under a circumstance at a temperature of 25° C. and at a relative humidity of 50%. Since such an electrophotographic photoreceptor is excellent in flexibility and has plasticity not too soft nor exhibiting fragility, the amount of film reduction due to wear is decreased during long time use, excellent surface smoothness is ensured, and there is no occurrence of injury or unevenness in density to the formed images.

Electrophotographic image forming apparatus have been utilized not only for copying machines but also generally for printers as output means of computers, etc. for which demand has been increased remarkably in recent years. In the electrophotographic image forming apparatus, toner images are formed by uniformly charging a photosensitive layer of an electrophotographic photoreceptor provided to the apparatus by a charger, exposing the same, for example, by a laser light corresponding to image information, and supplying a particulate developer referred to as a toner from a developing device to electrostatic latent images formed by exposure.
While toner images formed by deposition of the toner as an ingredient of a developer to the surface of the electrophotographic photoreceptor is transferred by transfer means to a transfer material such as recording paper. However, not all the toner on the surface of the electrophotographic photoreceptor is transferred to the recording paper but the toner partially remains on the surface of the electrophotographic photoreceptor. Further, paper dusts of recording paper in contact with the electrophotographic photoreceptor during development may sometimes remain being deposited to the electrophotographic photoreceptor as they are.
Since the residual toner and the deposited paper dusts on the surface of the electrophotographic photoreceptor give undesired effects on the quality of images to be formed, they are removed by a cleaning device. Further, a cleanerless technique has been developed in recent years and they are removed by a so-called development and cleaning system of recovering the residual toner by a cleaning function added to the developing means without providing independent cleaning means. For the electrophotographic photoreceptor, since operations of charging, exposure, development, transfer, cleaning and charge elimination are conducted repetitively, a durability to electrical and mechanical external forces has been demanded. Specifically, it has been required for durability against abrasion or injury occurred upon frictional rubbing to the surface of the electrophotographic photoreceptor or against degradation of the surface layer caused by deposition of active substances such as ozone or NOx generated upon charging by the charger.
For attaining the reduction of cost and free of maintenance in the electrophotographic image forming apparatus, it is important that the electrophotographic photoreceptor has sufficient durability and can operate stably for a long time. The physical property of the surface layer constituting the electrophotographic photoreceptor has a great concern with the durability and the long time stability of operation of the electrophotographic photoreceptor.
Hardness is one of indices for generally evaluating physical properties of the materials, particularly, mechanical properties, not being restricted only to the physical property on the surface of an electrophotographic photoreceptor. The hardness is defined as a stress from a material against intrusion of an indenter. An attempt of quantitizing the mechanical property of a film that constitutes the surface of the electrophotographic photoreceptor by using the hardness as a physical parameter for recognizing the physical property of materials has been conducted. For example, scratch resistant test, pencil hardness test and Vickers hardness test, etc. have been generally known as the test method for measuring the hardness.
However, each of the hardness tests described above involves a problem in measuring the mechanical properties of a material showing complicate behaviors of plasticity, elasticity (also including retarded component) and creeping property in combination such a film comprising or organic material. For example, while Vickers hardness is used for the evaluation of hardness of a film by measuring the length of an indentation, this reflects only the plasticity of the film and can not exactly evaluate the mechanical property such as of those comprising an organic material showing a deformation state also including elastic deformation at a large ratio. Accordingly, the mechanical property of a film constituted with an organic material has to be evaluated in view of various properties.
One of prior arts for evaluating the physical property of the surface layer of the electrophotographic photoreceptor having the organic photosensitive layer proposes the use of a universal hardness value (Hu) and plastic deformation ratio according to the universal hardness test as specified in DIN 50359-1 (for example, refer to the publication of Japanese Unexamined Patent Publication JP-A 2000-10320). This prior art discloses that mechanical degradation less occurs to the surface layer of the photoreceptor when defining Hu and plastic deformation ratio to a specified range. However, substantially all light sensitive bodies having charge transporting layers using polymeric binders generally used at present are included in the definition range for the elasticity disclosed in JP-A 2000-10320 and this results in a problem that a suitable range is not defined substantially.
Further, in another prior art for evaluating the physical property of the surface layer of the electrophotographic photoreceptor, it has been disclosed that the scratch resistance of the photoreceptor can be improved by defining the Young's modulus as the mechanical property other than the hardness to a specified range together with the universal hardness value (Hu) described above in the photoreceptor provided to electrophotographic image forming apparatus using a contact charging process (for example refer to the publication of Japanese Unexamined Patent Publication JP-A 2001-125298).
However, another prior art is restricted to the case of using the contact charging process. In the electrophotographic system using an electrophotographic photoreceptor for image formation, the process for charging the photoreceptor is generally classified into two types, i.e., contact charging as disclosed in another prior art and non-contact charging using, for example, a scorotron. Accordingly, a difference is naturally present between the contact charging and non-contact charging due to the difference of the charging mode, for the performance required for the photoreceptor used respectively in them. This results in a problem that a suitable range for defining the surface physical property value for the electrophotographic photoreceptor using the contact type charging process can not be applied as it is to the surface physical property of the electrophotographic photoreceptor using the non-contact type charging process.

Electrophotographic photoreceptor and image forming apparatus having the same


The present invention relates to an etchant for etching metal wiring, and the metal wiring etchant according to the present invention includes hydrogen peroxide at about 5 wt % to about 15 wt %, an oxidant at about 0.5 wt % to about 5 wt %, a fluoride-based compound at about 0.1 wt % to about 1 wt %, a nitrate-based compound at about 0.5 wt % to about 5 wt %, and a boron-based compound at about 0.05 wt % to about 1 wt %.

(a) Field of the Invention
The present invention relates to an etchant and a manufacturing method of a thin film transistor ("TFT") array panel using the same.
(b) Description of the Related Art
To form metal wiring in a substrate in a display device such as a liquid crystal display ("LCD"), a metal layer is generally formed by sputtering on a substrate, a photoresist is coated and exposed on the metal layer, and the metal layer is etched using the photoresist such that the metal layer is selectively maintained on only a predetermined region to form the metal wiring.
Here, the resistance of the type of metal used in forming the metal layer is an important factor in generating a resistor-capacitor ("RC") signal delay, and a technique for using metal wiring having low resistance has been developed.
Recently, copper (Cu), which has relatively low resistance and has relatively little negative environmental impact is increasingly gaining attention as a wiring material for low resistance applications, however copper has poor adherence with a glass substrate or a silicon insulating layer such that it is difficult to use as a single layer. To solve this problem, a multilayer including a copper alloy layer, a titanium (Ti) layer, a titanium alloy layer, a molybdenum (Mo) layer, or a molybdenum alloy layer having excellent adherence with a glass substrate or a silicon insulating layer is used as a lower layer below the copper layer.
To etch this multilayer, a peroxide-based etchant is typically used, and if the peroxide-based etchant includes metal ions at more than a predetermined concentration, peroxide decomposition is accelerated and is quickly decomposed into water and oxygen such that heat and a quick composition change may be undesirably generated, thereby generating instability.

Etchant for electrode and method of fabricating thin film transistor array panel using the same


An optical frequency discriminator having enhanced linearity is provided, which discriminator may be utilized in FM communications systems or in other applications. The discriminator has two interferometers with the optical path length difference for the first interferometer being .DELTA.L and for the second interferometer being m.DELTA.L where m>1. The optical FM signal is applied in parallel to both optical interferometers with approximately m.sup.3 times as much of the signal being applied to the first interferometer as to the second interferometer. Each interferometer has an output signal versus frequency characteristic with a substantially linear region about a center frequency, which center frequency is approximately equal to the center frequency of the input optical signal. The outputs from the interferometers are combined in a manner such as the difference in absolute value of the linear region characteristic slopes is obtained, the resulting output being a discriminated output which is substantially linear over an enhanced FM range.

Because of the large inherent bandwidth of optical systems, such systems are being increasingly utilized for transmitting information, generally over fiber optic cables, in telephony, cable television, data processing and other applications. Heretofore, such systems have typically used amplitude modulation because it is simple to implement. However, frequency modulation can provide an order of magnitude or more increase in signal-to-noise ratio. This is because the predominant noise sources are sources of amplitude noise rather than frequency noise. While this signal-to-noise ratio advantage has been taken advantage of for many years in the radio field, FM is not currently being employed to any extent in optical communications for a number of reasons.
One reason why optical FM communications are not more extensively utilized is that current applications are typically binary. For such applications, the signal-to-noise ratio improvement provided by FM is in most applications not sufficiently important to warrant the increased cost and complexity of an FM system. For analog communication or communication involving a multiplicity of discrete optical frequency levels, where noise may present problems, current optical frequency discriminators have been found to provide linearity over such a short frequency range that it is difficult to obtain distortion free outputs over a useful range of modulating frequencies.
The lack of an optical frequency discriminator which provides a substantially linear output over an extended frequency range is also a problem in other applications, for example, in many applications where accurate, high speed testing or measurement of the optical frequency of a changing signal is required. Frequency shift key (FSK) systems are one such application.
A need therefore exists for an improved frequency discriminator for use in optical FM communication systems and other applications, which discriminator provides a substantially linear output over an enlarged frequency range. It is an object of this invention to provide such a discriminator. A further object is to provide an enhanced optical FM communications system capable of providing distortion-free operation over an extended frequency range.

Optical frequency discriminator using two mach-zehnder interferometer arrangement


With a sealing structure for the sliding unit disclosed here, a sealing member of foam rubber is disposed in a way closing a clearance left open between widthwise opposing covering shells installed on a track rail. A covering shell is composed of a covering side secured to a side wall of a track rail, and seal supporters integral with the covering side. A slider is provided with a projection extending through between inside fronts of the sealing members, which come into abutment against one another. Upon the back-and-forward linear movement of the slider relatively to the track rail, the projection moves in a way deforming the sealing members in expansion/collapse fashion, with keeping the close sliding engagement with the confronting fronts of the sealing members so that the sealing members keep constantly closing the clearance left open between the covering shells.

1. Field of the Invention
The present invention relates to a sliding unit having a guide rail member and a slider fit in the guide member for back-and forth movement with respect to the guide member, and more particularly sealing means for the sliding unit to keep contaminants including debris, metal cuttings, oil mists and so on, which might occur owing to the back-and-forth movement of the slider, against escape outside the sliding units, and also isolate the sliding unit from foreign materials such as oil mists, dust and dirt which might otherwise enter into the sliding unit.
2. Description of the Prior Art
Sliding units constructed as shown in FIGS. 8 and 9 are conventionally known to work on a diversity of fields including semiconductor manufacturing apparatus, machine tools, various assembling equipments, testing instruments and so on, most of which is expected to work in controlled atmosphere as in a clean room. The prior sliding unit is primarily comprised of an elongated track rail 2 upward opened to have an U-shaped traverse cross-section, a slider 3B accommodated for lengthwise movement in an U-shaped recess 5 opened upward at 27 of the track rail 2, a recirculating-ball screw shaft 4 mating with the slider 3B, and a motor 9 for driving the recirculating-ball screw shaft 4 to turn about its own axis. The recirculating-ball screw shaft 4 is supported for rotation on the track rail 2 at both of a first bearing member 11 installed in an lengthwise end near the motor 9 and a second bearing member 12 installed in the lengthwise opposite end of the track rail 2, which is fastened to any basement by means of suitable fastener means such as screws. The slider 3B fits in the track rail 2 for linear movement through rolling elements running through between the slider 3B and the track rail 2. A bottom 6 and a pair of upright side walls 7A define in combination the recess 5 in the track rail 2. The side walls 7A are provided on their sidewise opposing inner surfaces with raceway grooves 8 while the slider 3B has raceway grooves confronting the raceway grooves 8 on the side walls 7A to define load raceways between them. Rolling elements may run through the load raceway defined between the raceway grooves 8 on the side walls 7A and the raceway grooves on the slider 3B, thereby allowing the slider 3B to move smoothly on the track rail 2.
The slider 3B has a pair of widthwise opposing flanges 13, which are angled upwards to rest thereon an object such as a workpiece table, not shown. The flanges 13 are made with threaded holes 14 for fixture means such as bolts to hold any object thereto. A dustproof cover 15B is attached to the forward and aft bearing members 11, 12 so as to shield the track rail 2 with the exception of sidewise clearances 33 where the flanges 13 are allowed to extend sidewise to move back and forth through there. Thus, the dustproof cover 15B is arranged above the slider 3B and the recirculating-ball screw shaft 4, which constitute in combination a torque-to-thrust conversion system for the sliding unit, thereby keeping the contaminants such as dust and debris against entering into and also coming from inside the track rail 2. The upright flanges 13 of the slider 3B, on which the object to be carried is loaded, extend widthwise outwardly of the tack rail 2 and then turn upwardly so as to be unobstructed with the dustproof cover 15B. The slider 3B has a nut 17 made therein with an internal helical groove that will mate with an external helical groove provided around the recirculating-ball screw shaft 4. The mating of the screw shaft 4 with the nut 17 constitutes a torque-to-thrust conversion system in which the rotation of the screw shaft 4 allows the nut 17 to move linearly lengthwise of the track rail 2. The forward and aft bearing members 11, 12 are mounted on railheads 20 of the upright side walls 7A of the track rail 2. The railheads 20 are finished in parallel with the raceway grooves 8 of the track rail 2.
Sensor rails 22 are disposed on sidewise outsides of the upright side walls 7A of the track rail 2, one to each side wall 7A. The sensor rails 22 are each provided with a limit sensor 23 at any preselected place to sense the associated flange 13 during back-and-forth movement, followed by issuing the detected signal to a controller through a lead wire 24 and a sensor connector 25. The motor 9 is energized depending on any control signal applied through a motor connector 28 to produce a torque transmitted to the recirculating-ball screw shaft 4 via a coupling 30. A fore-and-aft range over which the slider 3B is allowed to travel is defined with stoppers 31, 32 that are secured to the bearing member 11, 12, one to each bearing member.
In Japanese Patent Laid-Open No. 325070/1999, for example, there is disclosed a sealing construction for the sliding unit constructed as stated earlier, in which bellows-like sealing means are installed at the sidewise clearances 33 to keep foreign matter such as dust, debris and so on against entering into and coming from inside the sliding unit through the sidewise clearances 33. The bellows-like sealing means are each composed of at least one sealing member expansible owing to its own elasticity, which is secured to anyone of the confronting lengthwise edges of the upright side wall 7A of the track rail 2 and the dustproof cover 15B to close the associated clearance 33. When the slider 3B travels with respect to the track rail 2 along the clearances 33, the sealing members are easily subject to the elastic expansile and collapsed deformation and thus thrust aside by the action of the moving flanges 13.
Another example of the sealing constructions for the sliding unit made as stated earlier is disclosed in Japanese Patent Laid-Open No. 27235/2001, which is the senior application of the present applicant. With this prior sealing construction, the expansible sealing members are arranged in gaps between the track rail and the dustproof cover in a manner allowing the flanges to travel along the gaps as the slider moves relatively to the track rail. Each expansible sealing member is composed of upper and lower sealing parts that are urged elastically against each other to close the associated gap. When the flange travels along the associated gap, the upper and lower sealing parts are shoved apart from each other at only a region closely neighboring the moving flange to allow it to travel between the sealing parts, with keeping a sliding contact with the opposite surfaces of the moving flange. At the residual regions before and after the moving flange, however, the upper and lower sealing parts are kept in abutment against each other due to their own elasticity. The lower sealing part is made greater in elastic force than the upper sealing part to compensate the influence of gravity. Moreover, the upper and lower sealing parts are made in an elongated configuration that is attached at one lengthwise side thereof to any one edge of the gap and abutted against the counterpart with their own elasticity.
There are also known a conveying system with dust proofing means of the type disclosed in, for example, Japanese Patent Laid-Open No. 187906/2001. The conveying system is made of a rodless cylinder that includes a cylinder tube and a table moving in and out along the cylinder tube. A mounting stage is fastened to the table while a covering member is attached to the cylinder tube. A dustproof member is held between an inside surface of the covering member and any one of side surfaces of the cylinder tube and the mounting stage. The dustproof member may be subjected to elastic deformation in a sidewise direction that is perpendicular to a direction along which the table moves in and out.
With most prior sliding units constructed as stated earlier, nevertheless, any sidewise slits or clearances are left uncovered between the dustproof cover and the track rail to allow the flanges for supporting thereon a workpiece table to travel back and forward integrally with the slider along the clearances as the slider moves back and forth with respect to the track rail. This means many conventional sliding units should not be able to effectively prevent foreign materials such as dust and dirt, and so on from entering into the sliding unit through the clearances and also keep contaminants including debris, metal cuttings, and so on owing to the sliding unit itself against scattering all around through the clearances in the clean rooms where the semiconductor manufacturing machines and the like are installed. To cope with this, various ways constructed as stated earlier have been proposed to keep dust and debris against entering into and escape out of the dustproof cover through slits, clearances and so on. Nevertheless, the major obstacles to all the sealing constructions in which the bellows-like expansible sealing members are installed to close the sidewise clearances and in which the upper and lower expansible sealing parts are urged elastically against each other to close the clearances are necessitating the sophisticated expansible sealing members that are very tough to form them and thus become high in their production cost. Moreover, another problem faced in the expansible sealing members as stated above is how to make sure of more elasticity, with even superior sealing property.
To better deal with the obstacles and problem as stated above, the sealing member as shown in FIG. 7 has been developed, which has been filed by the present applicant under senior patent application in Japan, Japanese Patent Laid-Open No. 206530/2002. The sealing member is convenient to assemble it with the sealing structure in the sliding units and less expensive in production cost. With the sealing structure for the sealing unit in FIG. 7, a sealing member 1A rich in restoring force is secured to the dustproof cover 15A to lie in a clearance that is left opened between the dustproof cover 15A and the lengthwise side wall 7A of the track rail 2. The sealing member 1A constantly closing the clearance 33 between the dustproof cover 15A and the lengthwise side wall 7A of the track rail 2 experiences any deformation of expansion/collapse, with keeping sliding engagement with the associated wing 10A that pushes its way out the sealing member 1A as a sidewise wing 10A of the slider 3A moves back and forth between the sealing member 1A and the side wall 7A. The sealing structure constructed as stated earlier is envisaged to make certain of smooth back-and-forth movement of the slider, helping improve the sealing performance at the clearance 33 and also the durability of the sealing member 1A. Moreover, the sealing member 1A is easy to place correctly it in the associated clearance 33. In the sealing structure shown in FIG. 7, other most parts and components are the same or equivalent in function with those in sealing unit of the present invention, which will be described later. To that extent, the parts and components are given the same reference characters as in the sealing unit in FIG. 3, so that the later description will be applicable.
The present invention, therefore, has as its principal object to refine the sealing structure of the sliding unit disclosed in the Japanese Patent Laid-Open No. 206530/2002. The entire concept of the present invention is to shrink the sealing structure down in size and make it simple in construction in compliance with the sliding units being generally shrinking in size. The major object of the present invention is the provision of a sliding unit in which any clearances to be closed with the sealing members are concentrated on just a limited area on the sealing unit to deal with the need to much more shrink the sliding unit. In particular, the principal object of the present invention is to provide sealing means for a sliding unit, in which at least one projection extends from a slider out of a dustproof enclosure along a clearance left open in the dustproof enclosure to allow the projection to travel back and forth along the clearance, and a sealing member of expansible cellular material is installed to close elastically the clearance, but collapse to allow the projection to move along the clearance, with keeping sliding engagement with the sealing member thereby preventing foreign materials such as dust and dirt, oil mist and so on from entering into the sliding unit and also keeping contaminants including debris, metal cuttings, oil mists and so on owing to the sliding unit itself against escape outside the sliding unit through there into a controlled atmosphere such as clean rooms, laboratories and the like where the semiconductor manufacturing machines and so on are installed.
The present invention is concerned with sealing means for a sliding unit; comprising a guide component including a track rail having a pair of side walls spacing away widthwise from each other and extending lengthwise in parallel with each other, and a slider fit between the widthwise opposing side walls for back-and-forth sliding movement; wherein the guide component is made opened upwardly to provide a clearance defined between lengthwise edges lying in sidewise opposition to each other above the slider, and sealing members of elastic cellular material exhibiting a restoring force are disposed in the guide component, with their sidewise opposing inside fronts coming in abutment against one another to close the clearance; and wherein the slider is provided thereon with a projection to hold thereon an object, which extends through between the inside fronts of the sealing members in a way moving along the clearance with deforming the sealing members in expansion/collapse fashion to constantly keep a close sliding engagement with the inside fronts of the sealing members upon a back-and-forth movement of the slider relatively of the guide component.
In an aspect of the present invention, sealing means for a sliding unit is disclosed in which the projection extends lengthwise of the slider and has forward and aft tapered ends, and a mid-portion left thick in widthwise direction. In another aspect of the present invention, sealing means for a sliding unit is disclosed in which a wear-proof slideway belt is applied on the projection of the slider, with which the sealing member comes into sliding engagement.
In another aspect of the present invention, sealing means for a sliding unit is disclosed in which there is provided a resilient member extending lengthwise of the sealing member to aid the sealing member in speedy recovery from the deformation of expansion/collapse suffered when the projection of the slider moves through the clearance. In a further another aspect of the present invention sealing means for a sliding unit is disclosed in which the sealing member is made of foamed rubber. In another aspect of the present invention sealing means for a sliding unit is disclosed in which the sealing member is coated with a protective skin. In another aspect of the present invention sealing means for a sliding unit is disclosed in which the sealing member has a slim portion made tapered towards the inside front in traverse cross-section, and just the slim portion can be much subjected to an elastic deformation to such extent that the sealing member gets deformed to a substantially quadrangular configuration in cross section as the projection of slider moves with pushing the inside front of the sealing member. In a further aspect of the present invention, sealing means for a sliding unit is disclosed in which a wear-proof slideway belt extending fore-and-aft direction of the sealing member is applied on the inside front of the sealing member with which the projection of the slider comes into sliding engagement.
In another aspect of the present invention, sealing means for a sliding unit is disclosed in which the guide component is made with an air port that is connected with an air line to either suck and expel an atmosphere existing in a space enclosed with the guide component and the sealing members out of the space through there or blow a clean air into the space through there.
In another aspect of the present invention, sealing means for a sliding unit is disclosed in which the track rail is made up of a pair of the side walls and a bottom integral with the side walls in such a way that the side walls rise along widthwise spaced edges of the bottom, thereby forming as a whole a shape of trough.
In another aspect of the present invention, sealing means for a sliding unit is disclosed in which the side walls of the track rail are provided on their widthwise opposing inner surfaces with raceway grooves while the slider is provided on sidewise opposing surfaces thereof with raceway grooves confronting the raceway grooves of the side walls to define load raceways between them, and rolling elements installed in the slider run through the load raceways defined between the confronting raceway grooves, thereby allowing the slider to move back and forth relatively to the track rail.
In another aspect of the present invention, sealing means for a sliding unit is disclosed in which the slider includes a carriage fit in between the side walls of the guide component for sliding movement, and a torque-to-thrust conversion system mounted on the carriage and comprised of a nut mating with a recirculating-ball screw shaft, and wherein the guide component includes driving means to rotate the recirculating-ball screw shaft mating with the nut in the slider.
In a further another aspect of the present invention, sealing means for a sliding unit is disclosed in which the slider has just one projection extending in fore-and-aft direction midway between the widthwise opposing side surfaces thereof, and the guide component is comprised of the track rail, a pair of first covering shells to hold the sealing members therein, one to each shell, the first covering shells being each fastened to the associated side wall, with rising above the side wall lengthwise of the side wall, and end covers attached to forward and aft ends of the track rail, one to each end. In another aspect of the present invention, sealing means for a sliding unit is disclosed in which the covering shell is composed of a covering side extending along the associated side wall, and seal supporters formed integral with the covering side to define a recess lying above the slider to open toward a counterpart that are in widthwise opposition to the covering shell, and wherein the sealing members are installed in the recesses, one to each recess.
In another aspect of the present invention, sealing means for a sliding unit is disclosed in which the slider has two projections that extend lengthwise of the slider, with being spaced widthwise apart from each other, and wherein the guide component is comprised of the track rail, the end covers fastened to the forward and aft ends of the track rail, one to each end, and a second covering shell to hold the sealing members therein, the second covering shell including a pair of covering sides fastened to the side walls of the track rail, one to each side wall, so as to lie lengthwise of the track rail above the side walls, and covering ridges disposed midway between the widthwise spaced projections and fastened at their forward and aft ends to the end covers, and the covering sides and covering ridges being each angled in towards the associated projection at the lengthwise upper edges thereof. In another aspect of the present invention, sealing means for a sliding unit is disclosed in which the covering ridges are made of either an elongated Tee or elongated angles that lie back to back with each other at their legs midway between the projections, with other legs extending in directions opposite towards their associated projections, and wherein the sealing member is made up of a sidewise outside sealing block held in the associated covering side, and a sidewise inside sealing block flanking the associated leg of the covering ridge and held in the associated covering ridge.
In another aspect of the present invention, sealing means for a sliding unit is disclosed in which there is installed a sensor in opposition to any one side of the slider to sense where the slider is. Moreover, in another aspect of the present invention, sealing means for a sliding unit is disclosed in which the sealing member is made up of a major thick portion, and a relatively slim portion reaching from the major thick portion to the projection to mainly afford the deformation of expansion/collapse of the sealing member.
In another aspect of the present invention, sealing means for a sliding unit is disclosed in which a fastener plate is attached to any surface of the sealing member, where the sealing member is mounted to the covering shell. Moreover, sealing means for a sliding unit is disclosed in which the projection has a platform to rest thereon any object including an instrument, part, member, position control table, and so on.
With the sealing structure constructed as stated earlier, the sealing members are disposed on the widthwise opposing inside surfaces of the guide component, one to each inside surface, to close the clearance left opened between the inside surfaces. Upon the back-and-forward linear movement of the slider relatively to the guide component, the projection of the slider can move between the confronting inside fronts of the sealing members in a way deforming the sealing members in expansion/collapse fashion, with keeping the close sliding engagement with the confronting fronts of the sealing members so that the sealing members keep constantly closing the clearance left open between the covering shells. With the sliding unit in which the slider has only one projection, the atmosphere inside the sliding unit is just exposed to the environment at one clearance and, thus, can be kept surely in airtight condition. By the way of contrast, the slider with two projections are effective to make certain of keeping the object on the table steady and also smooth sliding movement of the slider without subject to lean even if the object on the table is lopsided in load.
In accordance with the sealing structure discussed here, it is preferred that the projection is made up of forward and aft tapered ends and a mid-portion left thick in widthwise direction. Moreover, sealing member is preferably made up of a major thick portion fit in the recess defined with the seal supporters of the covering shell composing the guide component, and a relatively slim portion reaching from the major thick portion to the inside front. The sealing member formed as stated just above helps make sure of their natural deformation in expansion/collapse fashion with keeping good closing condition, when the projection of the slider travels in a way shoving the sealing members aside. With the sealing structure of the present invention, thus, foreign materials such as dust and dirt, and so on are kept against either entering into or coming from inside the sliding unit through the clearance between the sealing members lying on the seal supporters of the covering shells. For example, debris, metal cuttings, and so on caused owing to the back-and-forth movement of the slider are kept against scattering all around through the clearance in the clean room, which will be thus maintained in any desired cleanliness. In addition, as the foam rubber for the sealing member is made in a simple quadrangular shape in traverse cross-section, rather than any sophisticated shape and structure that might introduce costly production requirements, the sealing member devised in the present invention can be much reduced in its production cost and also is easy to apply it to any clearance left open between the sidewise opposing surfaces of the guide component.
In accordance with the sealing structure of the present invention, the sealing member has resilient member extending lengthwise on the side making a sliding contact with the projection of the slider to aid the sealing member in speedy recovery from the deformation of expansion/collapse suffered when the projection of the slide moves in a way pushing the sealing member aside. Even if the sealing member were subjected to deterioration due to aging, for instance, even when the projection of the slider were actuated after stood idle for a long period, moreover, any spring force of the resilient member would aid the sealing member to immediately restore its initial shape from the deformation of expansion/collapse, without leaving signs of the associated projection on the sealing member. Thus, it will be expected that the spring force of the resilient member works to improve the response of the sealing member to the deformation of expansion/collapse, thereby raising the close engagement of the sealing member with other surfaces to make sure of high sealing performance.
With the sliding unit with the sealing structure constructed as stated earlier, the projection extending upward above the top of the slider is to rest thereon any load or object to be carried including parts, instruments, members, and so on for production machines. The sliding unit with the sealing structure of the present invention, although limited to just a small weight in load capacity to be carried, is suitable to shrink it down to the size most conformable to parts, instruments, table and so on, which weigh less enough to be carried on, for example semiconductor manufacturing equipment, position control table and the like. The sliding unit of the present invention is most suitable to work well on the machines that need the sliding unit much less in sidewise dimension, as is the case, for example in assembling machines in which many tables have to be placed one upon another within a limited space. Further, the sliding unit according to the second embodiment of the present invention has two projections extending upwards above the slider, which tolerate the sliding unit bearing the more massive load than in just one projection. Moreover, the sliding unit of the present invention, because the slider does not have any wings extending sidewise out of the sliding unit as in the prior sliding unit, is made much slim in widthwise dimension, compared with any types of the prior sliding unit.
The sealing member of the present invention is made in a quite simple shape, for example a substantially trapezoidal shape composed of a thick portion of quadrilateral in cross section and a tapered slim portion. This means that the sealing members are most easily installed in the recesses between the seal supporters of the covering shells, one to each recess, with their confronting inside fronts extending towards each other out of the seal supporters into abutment against one another. Moreover, the sealing member of such simple shape as stated earlier is infinitesimal in the likelihood of causing any irregular deformation in itself, helping realize improvement in sealing performance, with even inexpensive in production cost.
With the sealing structure of the present invention, it is said that the atmosphere inside the sliding unit enclosed with the guide component and the covering shells proves substantially airtight, except that it is exposed to the environment at just a tiny area where the projection extends outside through between the lengthwise fronts of the sealing members coming abutment against each other. Thus, the sliding unit is only needed to experience a minor amount of suction even when air existing inside the sliding unit has to be sucked out to expel debris, metal cuttings, oil mist and so on owing to the sliding unit itself. Thus, it is said that the sliding unit of the present invention is so constructed as able to easily provide the high cleanness-assured working environment. That is to say, the sealing structure of the present invention makes certain of keeping the contaminants including debris, metal cuttings, oil mist and so on, which might occur owing to the sliding unit itself, against scattering outside the sliding unit and also most reducing the occurrence of the debris ever realized. Consequently the sealing structure of the present invention serves good sealing function and there is no occurrence of any obstacle in the clean room where, especially, the semiconductor manufacturing machines are installed. Further, the sealing construction using the sealing member of porous substance such as foam rubber is effective to protect the sliding unit against an invasion of foreign matter such as dust and dirt through the clearance in the sliding unit.
In case where the sealing structure of the present invention is availed in a bad environment full of a cloud of dust, it will be appreciated to force a clean air in the reverse direction into the inside of the sliding unit through the air port that has been originally envisaged to expel the contaminated air out of the sliding unit, blowing the clean air out through the clearances or gaps in the sliding unit, thereby keeping the foreign matter such as dirt and dust against entering inside the sliding unit, which might otherwise ruin the sliding ability of the sliding unit in itself, and making sure of increasing the durability of the sliding unit. Usage as stated just above is most effective in the worst-working environment including woodworking sites full of sawdust, working shops to cut, grind and polish ceramics, and so on.
The above and other related objects and features of the present invention will be more apparent to those skilled in the art from a reading of the following description of the disclosure found in the accompanying drawings and the novelty thereof pointed out in the appended claims.


A distributed storage system including a server is configured to accept a request including a consistency indicator that flags for the server that cross datacenter consistency is desired. The server may be required to detect the consistency indicator and in response, to determine a consistency key based at least in part on the request. In an example aspect, the consistency key may comprise a hash value determined by a hash function shared across datacenters, whereby every datacenter may determine the same consistency key for a given resource and datacenter combination. The server may be further configured to determine a preferred datacenter for handling the request based at least in part on the consistency key, and thereafter to redirect the request to the preferred datacenter. In embodiments, the consistency indicator may also denote a scope of the strong consistency required by the calling client.

Cloud computing refers to the on-demand availability of computer system resources, especially data storage and computing power typically provided in geographically dispersed datacenters, over the Internet without direct active management by the user. Modern cloud computing has many qualities, perhaps none more important than high availability. Businesses in particular utilize cloud computing platforms for many mission critical applications including, e-commerce and data warehousing applications. For many applications, any period of system unavailability can be very expensive to system users. Accordingly, cloud computing platforms typically make extensive use of redundancy within each datacenter, as well as geographic redundancy whereby additional redundant datacenters are distributed about the globe. Such redundancies involve both hardware and data redundancy, the latter of which involves distribution of resource replicas between geographically diverse datacenters.
Such replication and distribution of resource replicas between datacenters is not, however, always a fast process. Transaction data, for example, and other data that underly business applications may be quite voluminous, and/or may change rapidly. In such instances, it can be difficult to ensure that data is consistent across diverse datacenters.
Business applications may, however, require and assume that a consistent view of data resources is always available, and that the data written by one client is always provided to that or other clients during subsequent read of that data. Current approaches to this problem are often inadequate. For example, cloud computing platforms may support 'eventual consistency' whereby written data is eventually consistent across datacenters (i.e., after background replication completes). Alternatively, consistent views of data may be provided to clients that connect to the same datacenter (i.e., the datacenter to which the data is written initially). In yet another example, where a cloud computing platform provides session consistency, disparate clients may share a session. The first solution is not timely, and the second is of little use to a client that is connected to a different datacenter. According to the last solution, session data is shared between clients that may be widely distributed throughout the world.

Cross datacenter read-write consistency in a distributed cloud computing platform


A system and method for a vehicle including a communication gateway in a vehicle configured to establish a wireless communication connection with a portable device; a plurality of object sensors that detects objects surrounding the vehicle; a remote park assist system configured to (i) identify at least one parking space based on data received from the plurality of object sensors; (iv) determine a movement trajectory for the vehicle; (v) transmit a vehicle maneuver request to the portable device; (vi) receive a plurality of responses from the portable device in response to transmitting the vehicle maneuver request; and (vii) maneuver the vehicle based on the plurality of object sensors, the plurality of responses, and the movement trajectory; and the portable device, in response to receiving a request from the remote park assist system, is configured to transmit the plurality of responses.

This section provides background information related to the present disclosure which is not necessarily prior art.
Remote park assist (REPA) systems identify a parking space based on a plurality of object sensors located on the exterior of the vehicle. The REPA system determines a movement trajectory for the vehicle to maneuver the vehicle into or out of the parking space. The REPA system may determine various vehicle parameters related to one or more brakes, a transmission, an engine, or a steering system for the movement trajectory. A driver of the vehicle may remain in the vehicle or may get out of the vehicle while the REPA system is maneuvering the vehicle into or out of the parking space. The REPA system maneuvers the vehicle as long as a continuous movement gesture is performed on a portable device by the driver of the vehicle. This helps to ensure the driver is held responsible for the vehicle even under automated control of the REPA system.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
In the drawings, reference numbers may be reused to identify similar and/or identical elements.

Remote park assist message flow systems and methods


Provided is a vinyl alcohol-based copolymer, obtained by saponifying a copolymer of vinyl acetate and a polyfunctional monomer, wherein the polyfunctional monomer contains two or more ethylenic double bonds in its molecule, the vinyl alcohol-based copolymer has a side chain containing an ethylenic double bond and a molar ratio (d) of the ethylenic double bond to a total of vinyl alcohol units and vinyl acetate units is from 0.05/100 to 2/100, and the vinyl alcohol-based copolymer is water soluble.

As a vinyl alcohol-based polymer (hereinafter, may be abbreviated as a PVA) having an ethylenic double bond introduced into the molecule, those described in Patent Documents 1 to 5 below are known. Patent Document 1 describes a PVA post-modified with a reactive molecule containing an ethylenic double bond, thereby having an ethylenic double bond introduced into the side chain of the PVA. Patent Document 2 describes a product obtained by, after obtaining a vinyl ester-based copolymer having a protected ethylenic double bond, removing the protection and saponifying it. Patent Document 3 describes a PVA having an ethylenic double bond introduced into an end of the molecular chain using aldehyde or the like as a chain transfer agent. Patent Document 4 describes a product obtained by washing and drying after obtaining a carboxyl group containing PVA by saponification after copolymerizing a maleic acid derivative and a vinyl ester monomer, thereby randomly introducing an ethylenic double bond using the carboxyl group as a starting point into the main chain. Patent Document 5 describes a product obtained by washing and drying what is saponified after copolymerizing carbon monoxide and a vinyl ester monomer, thereby introducing an enone structure into the main chain.
These PVAs having an ethylenic double bond introduced into the molecule are widely utilized as a photosensitive material and a dispersion stabilizer for suspension polymerization and emulsion polymerization of a vinyl-based monomer. Among all, when these PVAs are used as a dispersion stabilizer for polymerization, the ethylenic double bond present in the molecular chain of the PVA is involved in chemical bond formation with dispersoids and high polymerization stability is exhibited even in a small amount of use.
However, in the production methods described in Patent Documents 1 and 2 above, a step for introducing an ethylenic double bond into the PVA is separately necessary other than the step of producing a PVA. Performance of them is therefore limited from the economic perspective. When an ethylenic double bond is introduced into the main chain of the PVA molecule by the production methods described in Patent Documents 3, 4, and 5 above, such PVAs are easily colored by heating and thus their use is limited. In addition, when such PVAs are used as dispersion stabilizers for polymerization, there is a problem of coloration of the polymers to be produced.

Vinyl alcohol copolymer and method for producing same


Apparatus for reboring a damaged portion in the first of first and second bores (14,15) in a counterbored workpiece (12) contemplates a first pilot (35) for extending through the second bore and engaging the first bore interiorly of the damaged portion, a cylinder (41) for supporting and axially driving the first pilot and the workpiece, a second pilot (55) for engaging the first bore exteriorly of the damaged portion, a cylinder and motor (52) for supporting and axially driving the second pilot in opposed relation to the cylinder for supporting and axially driving the first pilot, whereby the first bore is concentrically aligned, and a boring device (53) mounted on the cylinder and motor for supporting and axially driving the second pilot for reboring a portion of the first bore in the workpiece. The method for repairing the bore of the workpiece includes the steps of mounting the workpiece on the first pilot engaging the first bore interiorly of the damaged portion, positioning the second pilot for engaging the first bore exteriorly of the damaged portion, driving the first and second pilots into closer positioning to effect concentric alignment of the first bore in the workpiece with the first and second pilots, simultaneously moving the first and second pilots to clamp the workpiece against a fixed plate while maintaining the concentric alignment of the first bore with the first and second pilots, disengaging the second pilot from the extremity of the first bore of the workpiece, and inserting a boring device into the extremity of the first bore for reboring the damaged portion thereof.

There are various industrial applications where a workpiece has a throughbore which is formed by two counterbores where one of the bores may be particularly subject to wear. Such excessive wear may be brought about by the material that the workpiece is made of or the action of whatever operative components work in the bore or a combination of these and perhaps other factors. Particularly in regard to workpieces which may be complexly configured such that the original manufacturing may make the workpiece relatively expensive, it is highly desirable if a damaged bore in an otherwise usable workpiece can be repaired or in some manner reconditioned.
One such device of this type exists in the automotive field in the form of the main housing for many power rack and pinion steering assemblies. The power rack and pinion steering housing as manufactured by or for several automotive manufacturers consists of an elongate, irregularly shaped housing which seats a spool valve having a plurality of peripheral grooves which interact with a plurality of ports in the housing. Since the housing is constructed of aluminum for weight reduction purposes the pressurized fluid in the spool valve grooves eventually forms score lines or recesses in the housing. At some point in time the score lines become sufficiently pronounced such that fluid leakage between the various spool valve grooves takes place to an extent that the operation of the power assist to the steering mechanism is adversely affected.
Due to the significant costs involved in replacement of the entire housing, efforts are being made in the vehicle repair industry to recondition or rebuild the housings. The housings are generally an elongate member for receiving a shaft having the grooved spool valve at one end and a fluted gear near the opposite end for engaging a rack. The bore for the shaft is counterbored from both ends with one bore designed to receive the spool valve and supporting bushings, bearings and seals and the other end accommodating the fluted gear portion of the shaft. As a basic manufacturing technique a pair of counterbores are made to receive these two portions of the shaft. According to standard manufacturing techniques the two bores in the counterbored housing are not necessarily exactly concentric. Any effort to rebore or to rebore and fit the bore housing the spool valve with a metallic sleeve necessarily contemplates that the rebore be made with a reamer which is exactly concentrically aligned with the original bore. If this alignment is not achieved, the shaft or rod mounting the spool valve will be misaligned with and therefore bind in the associated bushings and bearings on which it rides. Even minor misalignment produces a defective power steering unit which cannot be used successfully as a replacement part.
As a result various attempts have been made to devise a method and apparatus for reboring such steering housings with concentric alignment achieved to within the requisite tolerances of approximately one half a thousandths of an inch. For the most part these efforts at repairing the housings by reboring and inserting a sleeve have proven to be costly in terms of requiring a substantial amount of time of skilled machinists and proving difficult to maintain within required tolerances, thus producing numerous scrap parts or rebuilt parts with marginal operating parameters.
One approach to endeavoring to rebore such housing involves utilization of the original tooling which was employed to hold the housing to make the original bore comply with use of a larger reamer. It is believed that this has proved to be largely unsuccessful evidently for the reasons that variations in different versions of the same tooling and variations in the outer dimensions of the housing are of a sufficient magnitude such that the requisite precision in achieving concentric alignment with the original bore cannot be repeatedly achieved. Thus, the concept of reprocessing damaged housings on the original tooling has not achieved wide acceptance.
Another approach which has been employed to some extent involves the attempted processing of the power steering housings on a conventional boring machine. In this instance the two ends of the housing, i.e., the counter bore openings, are aligned and then the housing is retained while an enlarged rebore is done at the end having the bore housing the spool valve. This approach presumes that the two counterbores are exactly concentrically aligned; however, it is to be noted that the two bores are not in fact concentrically aligned in the actual housings which are manufactured. Therefore, the error by way of initial misalignment of the bores is coupled with whatever error may exist by way of effecting the aforesaid end to end alignment. For these reasons substantial difficulties have been encountered in endeavoring to locate and effect rebore on conventional milling machines.
To applicant's knowledge no method and apparatus have been devised which will obviate the above discussed problems of achieving sufficient accuracy in the reboring of non-aligned counterbores in a workpiece to quickly and repeatably effect precision reboring for extremely close tolerance applications. The aforedescribed methods and apparatus not only fail to achieve sufficient precision in a large number of instances but also tend to be slow and time consuming, thus increasing the cost of endeavoring to repair workpieces of this type.

Apparatus for aligning and reboring a damaged throughbore of a housing


System, methods, and other embodiments described herein relate to an improved approach to reverse engineering binary code through the use of machine learning and image processing. In one embodiment, a method includes, in response to receiving, as an electronic input, a code segment of code that is represented in a binary format, transforming the segment into an image to visually represent the binary format of the segment. The method includes generating, as an electronic output from a classifier, a segment indicator that is based, at least in part, on the image and that specifies source code corresponding to the segment in order to reverse engineer the segment into the source code using the classifier.

Identifying program source code from compiled machine code, i.e., binary, is a complex task. These complexities can arise because the binary representation obfuscates the original source code of the program. That is, binary machine code that is compiled from the original source code can be generated in several different ways according to implementations of a particular compiler to achieve similar functionalities, and thus directly reversing the binary into the exact original source code is generally difficult. This can be due to a lack of knowledge about the compiler that generated the binary, and, more generally, the overall complexity of the binary representation.
For example, in the context of maintaining security, it can be useful to reverse engineer a compromised binary or a binary of independent malicious code to unfold how a malicious attack compromised the program or how a particular piece of malicious code functions. However, attempting to reverse engineer binary code generally involves multiple steps that can include approximating the original source code from the binary code using imprecise tools, and then manually reconstructing the source code using the approximation as a base. This multiple step process can be tedious and often fails to provide a completely accurate reconstruction.

Systems and methods for identifying source code from binaries using machine learning


A parallel optical transceiver module is provided that has a heat dissipation system that dissipates large amounts of heat, while also protecting the laser diodes, ICs and other components of the module from particulates, such as dust, for example, and from mechanical handling forces. The heat dissipation system is configured to be secured to the optical subassembly (OSA) of the module such that when the OSA is secured to the upper surface of the leadframe of the module, the OSA and the heat dissipation system cooperate to encapsulate at least the laser diodes and laser diode driver IC in a way that protects these components from dust and other particulates and from external mechanical forces. The heat dissipation system of the module is disposed for coupling with an external heat dissipation system, e.g., with a heat dissipation system that is provided by the customer.

Parallel optical transceiver modules typically include a plurality of laser diodes for generating optical data signals, laser diode driver circuitry for driving the laser diodes, a controller for controlling operations of the transceiver module, receiver photodiodes for receiving optical data signals, receiver circuitry for demodulating and decoding the received optical data signals, and monitor photodiodes for monitoring the output power levels of the laser diodes. Parallel optical transceiver modules typically also include an optical subassembly having optical elements that direct the optical data signals produced by the laser diodes onto the ends of optical fibers and that direct optical data signals received over optical fibers onto the receiver photodiodes.
The laser diode driver circuitry is typically contained in an integrated circuit (IC) having electrical contacts pads that are electrically coupled by electrical conductors (e.g., bond wires) to electrical contacts pads of the laser diodes. The number of laser diodes that are included in a parallel optical transceiver module depends on the design of the module. A typical parallel optical transceiver module may contain six laser diodes and six receiver photodiodes to provide six transmit channels and six receive channels. A typical parallel optical transceiver module that has no receiver photodiodes (i.e., an optical transmitter module) may have, for example, twelve laser diodes for providing twelve transmit channels. The laser diode driver ICs that are commonly used in these types of parallel optical transceiver or transmitter modules generate large amounts of heat that must be dissipated in order to prevent the laser diodes from being adversely affected by the heat. Due to the large amounts of heat generated, the tasks associated with designing and implementing a suitable heat dissipation system are challenging.
In addition, in a typical parallel optical transceiver or transmitter module, the laser diode driver IC is typically placed in very close proximity to the laser diodes to enable the bond wires that couple the contact pads of the laser diodes to the contact pads of the driver IC to be kept relatively short. Long bond wires can lead to electromagnetic coupling between adjacent bond wires that can degrade signal integrity, thereby detrimentally affecting the performance of the module. Placing the driver IC in close proximity to the laser diodes and using relatively short bond wires makes designing and implementing a suitable heat sink solution for the module even more challenging.
The heat dissipation systems used in existing parallel optical transceiver and transmitter modules typically comprise a heat sink structure that is mechanically and thermally coupled to a lower surface of a leadframe of the module. The laser diodes and laser diode driver IC are mounted on an upper surface of the leadframe. The coupling of the heat sink structure to the lower surface of the leadframe provides a thermal path for heat dissipation that is: from the laser diodes and driver IC down into the upper surface of the leadframe; from the upper surface of the leadframe through the leadframe to the lower surface of the leadframe; and then from the lower surface of the leadframe into the heat sink device secured thereto. The heat sink structure is typically a generally planar sheet of thermally conductive material, such as copper or aluminum. A thermally conductive material or device is used to secure the heat sink structure to the lower surface of the leadframe. As an alternative to using a generally planar heat sink structure secured to the lower surface of the leadframe, one or more heat sink devices may be coupled to other locations on the leadframe, such as to the side edges of the leadframe. In the latter case, heat that is transferred into the leadframe is transferred to the side edges of the leadframe and into the heat sink devices. In this type of arrangement, the leadframe functions in part as a heat spreader device to move heat generated by the laser diodes and laser diode driver IC away from those devices and then, via the heat sink devices coupled to the side edges of the leadframe, out of the leadframe.
One of the problems associated with the heat dissipation systems described above is that they do not protect the laser diodes and the laser diode driver IC from particulates, such as dust, for example. In fact, the process of securing the heat dissipation system to the leadframe may result in dust or other particulates being deposited on the laser diodes, which can degrade their performance. Additionally, some amount of handling typically occurs during the process of mounting the module on the PCB, which can lead to the laser diodes, the laser diode driver IC, bond wires, and other components of the module being damaged. Thus, while the customer's heat dissipation system may be effective at dissipating heat, it typically does not protect the laser diodes and ICs of the module from dust and other particulates or from mechanical handling forces that can damage these components.
Accordingly, a need exists for a parallel optical transceiver module having a heat dissipation system that is capable of dissipating large amounts of heat and that protects the laser diodes and other components of the module from particulates, such as dust, for example, and from mechanical handling forces.

Parallel optical transceiver module having a heat dissipation system that dissipates heat and protects components of the module from particulates and handling

Avago Technologies Fiber IP (Singapore) Pte. Ltd.