The present invention discloses a method for guaranteeing reliability of end-to-end QoS, including: a. detecting and determining whether there is a failure on a Label Switched Path (LSP); if there isn't, returning to the process of detecting; otherwise, determining whether there is a backup LSP for the failed LSP; if there is, an edge router or a transmit router switching service streams and corresponding resources from the failed LSP to the backup LSP based on a certain policy; otherwise, a resource control function (RCF) entity allocating a new LSP according to network topologies for the service streams born on the failed LSP, and switching the service streams from the failed LSP to the newly allocated LSP, and releasing the path resources formerly occupied by the service streams. The method can guarantee service continuity and reliability of QoS in a bearer network.

Along with the continuous growth of the Internet, various network services appear, and advanced multimedia systems emerge in endlessly. Since real-time services are relatively sensitive to network characteristics such as transmission latency, delay jitter etc., when there are FTP services of high burstiness, or HTTP services with image files on the network, the real-time services may be greatly affected. Besides, since multimedia services may occupy much bandwidth, key services, which need to be guaranteed in the existing network, can not be reliably transmitted. Therefore, in order to guarantee reliable transmission of key services, various QoS technologies arise. The Internet Engineering Task Force (IETF) has proposed a good many service models and mechanisms to satisfy QoS requirement. At present, a scheme, which adopts an Integrated Service (INT-SERV) model on the access or edge area of a network, and adopts a Differentiated Service (DIFF-SERV) model on the core area of the network, is comparatively approved in the art.
In the Diff-serv model, a measure of setting priority levels is provided to guarantee the QoS. Although this model has a feature of high line efficiency, the real effectiveness is unpredictable. Therefore, an independent bearer control layer is introduced into the Diff-serv Model of the backbone network in the art, a special set of Diff-serv QoS signaling mechanisms are provided, and also a resource management layer is specially established for the Diff-serv network, which is used for managing topology resources of the network. This Diff-serv mode of resource management is called a Diff-serv model with an independent bearer control layer. FIG. 1 is a schematic diagram of the model. The 101 is a service server, such as a Call Agent (CA), which belongs to the service control layer for implementing functions such as soft switch. The 102 is a bearer network resource manager which belongs to the bearer control layer. Solid circles, such as the 103, are Edge Routers (ER); hollow circles, such as the 104, are Core Routers (CR), and circles filled with skew lines, such as the 105, are Boundary Routers (BR). Here, the ERs, CRs and BRs all belong to the bearer network, so they can be generally called as Connection Node (CN), and the CRs and BRs together can be called as Transmit Router (TR). In FIG. 1, every dot line ellipse in the bearer network represents a management domain, which is managed by a bearer network resource manager, and each domain includes a BR or an ER, and several CRs.
In the model of FIG. 1, the bearer network resource manager is in charge of configuring managing policies and network topologies, allocating resources for service bandwidth applications of users. The users' service bandwidth application requests and results, and path information of the service applications allocated by bearer network resource managers are transferred among the bearer network resource managers of management domains by signaling. When processing a user's service bandwidth application, the bearer control layer may define a route for the user's service, and the bearer network resource manager may inform the ER to forward the service stream according to the defined route.
Here, the route stored in a bearer network resource manager includes: a signaling route and a service route. The signaling route refers to a procedure how a bearer network resource manager looks for a next hop bearer network resource manager, and the service route, including an intra-domain route and an inter-domain route, refers to a procedure how a bearer network resource manager looks for an appropriate bearer LSP according to information of the service stream.
Usually, users' service streams are forwarded on the bearer network according to paths designated by the bearer control layer. Presently, a Multi-protocol Label Switching (MPLS) technology is employed in the art to establish a LSP via resource reservation according to the path of service stream designated by the bearer control layer; or a Resource Reservation Protocol-Traffic Engineering (RSVP-TE) protocol, or an explicit routing mechanism such as Constraint Routing-Label Distribution Protocol (CR-LDP) is employed to establish an end-to-end LSP.
In a bearer network, reliability guarantee is very important. At present, there is a good deal of methods to guarantee reliability in a bearer network, and the simplest one is cold backup, which means using one network entity as a complete backup of another network entity. For example, entity B is taken as a cold backup for entity A. When entity A fails, the backup entity B will totally substitute for entity A. Of course, both bearer connections and service connections of former entity A should be rebuilt in this case.
The cold backup method is easy to implement at the initial stage of network construction, when switching and smoothing are not needed in real time by nodes. However, this method is only suitable for a small-size network, because the small-size network has following characteristics: small traffic volume, relatively low real-time requirement, allowable to interrupt and rebuild connections, and unnecessary for LSPs to perform hot switching.
The inventor found: in a network with an independent bearer control layer, when LSPs are used as paths for bearing service streams, it lacks effective protection for the LSPs at the present technical scheme. In this case, when a failure appears on an LSP, service streams born on the LSP will be interrupted, which may give an undesirable impact on users' service experience.

Method and system for guaranteeing reliability of end-to-end quality of service


A substrate holder to support a substrate in a vertical position in a substrate processing device that performs a process on the substrate, where the process involves forming a plasma in the space around the substrate. The substrate holder includes a base plate and a plurality of supporting claws that are attached to the base plate and arranged so as to come into contact with the outer edge of the substrate and provide vertical support for the substrate. At least one of the plurality of supporting claws is a movable supporting claw that can be brought into contact with and separated from the outer edge of the substrate. When a substrate has been loaded into the holder, the space around the substrate is substantially filled by the base plate or by a member attached to the base plate. The gap formed around the periphery of the substrate between the substrate and base plate is narrower at locations in the circumferential direction to the front and rear of the supporting claws, compared to that at other positions in the circumferential direction along the periphery of the substrate.

1. Field of the Invention
The present invention relates to apparatus used in substrate processing, and more specifically, to a substrate holder used to support a substrate in a vertical position during the performance of a process on the surface(s) of the substrate.
2. Description of the Prior Art
The surfaces of substrates are routinely subjected to various processes in the production of LSIs (large scale integrated circuits), LCDs (liquid crystal displays), and data storage disks. In the production of data storage disks of the type used in "hard disk" drives, a substrate holder may be used to vertically support a substrate having a hole formed in its middle. This permits a processing step, e.g., thin film deposition, to be efficiently performed on both sides of the substrate.
FIG. 6 is a front view showing a prior art substrate holder 50. FIG. 7 is an isometric view which illustrates the operation of substrate holder 50 shown in FIG. 6. Substrate holder 50 shown in FIGS. 6 and 7 includes a vertical base plate 11, fixed supporting claws 12, and a movable claw 13, with claws 12 and 13 connected to base plate 11.
As shown in FIGS. 6 and 7, base plate 11 is shaped in the form of a rectangular plate and is provided with a "J"-shaped cut-out. The curved portion of this "J"-shaped cut-out (referred to as the "curved part") is typically provided with four fixed support claws 12. As FIGS. 6 and 7 show, fixed support claws 12 are disposed at positions arranged symmetrically about a vertical line 10 passing through the lowest point of the "J" (referred to as "central axis 10").
Each of fixed support claws 12 is an "L" shaped member formed by bending a thin ribbon-shaped piece of metal or similar material. Notches are provided in the cut-out portion of base plate 11, and fixed support claws 12 are each disposed within the notches. The support claws 12 are fixed to base plate 11 with screws. The end of each fixed supporting claw 12 points toward the center of curvature of the curved part, and "V"-shaped indentations are formed at their distal ends as shown in FIG. 7.
Movable support claw 13 is fixed to the upper surface of base plate 11. Movable support claw 13 is also a ribbon-shaped member bent into an "L" shape. One end of movable claw 13 is fixed to the upper end surface of base plate 11 with screws, with the distal tip portion positioned directly on central axis 10 and pointing downward. A "V"-shaped indentation is formed in the downward distal end of moveable claw 13 in the same manner as for fixed support claws 12.
The operation of the above mentioned conventional substrate holder 50 will now be described. Substrate holder 50 supports a substrate 2 which is a flat disk with a hole 20 at its center, e.g., a hard disk substrate. Substrate 2 is placed in and removed from substrate holder 50 by a transfer mechanism 4 equipped with a substrate pick-up 3 that holds substrate 2 (see FIG. 7).
As FIG. 7 shows, an opening/closing device 5 which actuates movable support claw 13 is positioned near substrate holder 50. Movable support claw 13 acts as a leaf spring, and opening/closing device 5 includes an opening/closing pin 51 which causes movable support claw 13 to bend by displacing the end of movable support claw 13 upwards. Opening/closing device 5 also includes a moving mechanism 52 which causes pin 51 to displace the end of claw 13 laterally toward or away from substrate holder 50 to engage or disengage pin 51 from claw 13.
The way in which a substrate 2 is loaded on substrate holder 50 will now be described. After substrate pick-up 3 engages substrate 2 by inserting its tip into hole 20 in the center of substrate 2, the substrate is transferred horizontally to the vicinity of substrate holder 50 by transfer mechanism 4. Pin 51 of opening/closing device 5 is moved horizontally (i.e., laterally) by moving mechanism 52 to a position below movable support claw 13 of substrate holder 50. Pin 51 moves up, causing movable support claw 13 to bend and be displaced upward, as shown by the dotted line in FIG. 6. This opens movable support claw 13.
Transfer mechanism 4 then moves substrate 2 into alignment with base plate 11 such that substrate 2 is positioned between movable support claw 13 and fixed support claws 12. Transfer mechanism 4 then causes substrate pick-up 3 to descend slightly, such that substrate 2 rests on and is supported by fixed support claws 12.
Moving mechanism 52 of opening/closing device 5 then causes pin 51 to descend, such that movable support claw 13 is returned to an approximately horizontal position (the solid line in FIG. 6). This causes the end of movable support claw 13 to contact the upper edge of substrate 2, pressing down on substrate 2 from above. Substrate pick-up 3 then withdraws from substrate holder 50 and is returned to a standby position by transfer mechanism 4, ready to pick up another substrate. Pin 51 is then disengaged from moveable claw 13 and is also moved to a prescribed "standby" position.
When extracting substrate 2 from substrate holder 50 the opposite procedure is performed. Moving mechanism 52 of opening/closing device 5 causes pin 51 to move to a position below movable support claw 13, and then lifts pin 51, displacing the end of movable support claw 13 and disengaging it from the substrate. Transfer mechanism 4 inserts the end of substrate pick-up 3 into hole 20 in the center of substrate 2. Substrate pick-up 3 rises up slightly to hold and disengage substrate 2 from support claws 12. Transfer mechanism 4 then withdraws substrate 2 away from substrate holder 50.
FIG. 8 is a plan view of an exemplary substrate processing device which uses substrate holder 50 of FIGS. 6 and 7. The substrate processing system shown in FIG. 8 includes a substrate loading/unloading chamber 61 and an adjacent processing chamber 62 separated by gate valve 66. Chamber 61 may be a load lock chamber. A substrate 2 to be processed is loaded on substrate holder 50 inside chamber 61. Each substrate 2 is supplied to process chamber 62 on a separate substrate holder 50. After substrate 2 has been processed in processing chamber 62, substrate holder 50 is returned to chamber 61, where it is removed from substrate holder 50.
As an example of a substrate processing device, FIG. 8 illustrates a sputtering device which produces magnetic thin films. Two sputtering sources 63 are provided inside of processing chamber 62. Sputtering sources 63 each consist of a sputter target 631 and a magnet assembly 633 provided at the rear of target 631. A sputtering power source 632 which applies a prescribed voltage to target 631 is also provided.
Magnet assembly 633 comprises a central magnet 634 and a ring-shaped peripheral magnet 635 which surrounds central magnet 634. Magnet assembly 633 establishes arch-shaped magnetic flux lines 636 passing through target 631. When a voltage is applied to the target at low pressure, magnetic flux lines 636 give rise to magnetron sputtering.
Process chamber 62 is equipped with a vacuum pumping system 64 and process gas supply system 65 for the introduction of a process gas into its interior. When sputtering power source 632 is operated while introducing the process gas into chamber 62, a magnetron sputtering discharge occurs in the space adjacent to the surface of target 633, and a magnetron plasma, P, is formed in the regions between the sources 63 and the substrate.
As FIG. 8 shows, the pair of sputtering sources 63 are provided on both sides of substrate 2 which is supported by substrate holder 50. Accordingly, magnetron plasma P is formed on both sides of substrate 2, and film deposition is performed simultaneously on the surfaces of both sides of substrate 2.
It is desired that a substrate processing system, such as the one described, be capable of producing highly uniform films on the entire surface of the substrate. For example, in a process to make magnetic thin films on substrates for magnetic recording media, the processing device should produce a high-quality magnetic thin film on both sides of the substrate that extends as close as possible to the outer edge of the substrate in order to increase the recording capacity of the disk.
However, in research conducted by the present inventors, it was determined that when a substrate holder of the type described with reference to FIGS. 6-7 is used, although a high-quality magnetic thin film can be made in the central portion of the substrate, the film is not uniform across the entire surface of the substrate. In particular, it was determined by the inventors that films produced using substrate holder 50 have localized defects (i.e., non-uniform film quality) in regions near the edge of the substrate.
FIGS. 9A and 9B are graphs which illustrate the problem caused by using a conventional substrate holder which is remedied by the present invention. FIGS. 9A and 9B show the modulation characteristics of a magnetic thin film produced using substrate holder 50 shown in FIGS. 6 and 7. The modulation characteristics indicate whether or not there are abnormalities in the modulation (i.e. output signal) of a signal read back from a substrate. In the present case, they show whether or not the magnetic characteristics of the magnetic thin film produced on the substrate are uniform in the area at the periphery of the substrate. Note that FIGS. 9A and 9B represent the magnitudes of the coercive force and remnant magnetic flux in the circumferential direction, with those characteristics being represented by an electrical signal.
FIG. 9A is a graph showing the characteristics of a magnetic thin film deposited on a substrate 95 mm in diameter using the conventional substrate holder of FIGS. 6 and 7 at a radial distance of 40 mm from the substrate center. FIG. 9B is a graph showing the magnetic characteristics of a magnetic thin film deposited on a substrate 95 mm in diameter using the conventional substrate holder of FIGS. 6 and 7 at a radial distance of 46.5 mm from the substrate center. As the figures show, the magnetic characteristics are uniform at 40 mm, because the modulation curve is essentially constant. However, at 46.5 mm from the center, unwanted modulation occurs as indicated by peaks or localized jumps in the magnetic characteristics (which are observed at five places in the graph) showing that the film is not uniform. Occurrence of this sort of modulation is likely to result in errors during magnetic recording, and is a source of bad sectors on the storage medium.
After making a detailed study of the factors which might be responsible for causing these modulation peaks, the present inventors concluded that the positions of the peaks correspond to the positions of the support claws of the substrate holder shown in FIG. 6. That is, the positions of the peaks of FIG. 9B coincides with the positions of the support claws. The inventors have concluded that the support claws are responsible for the observed non-uniformity in the magnetic characteristics of the film.
The inventors have determined that the nonuniformity caused by the support claws is due to the influence of the support claws on the plasma formed during film deposition. In a conventional substrate holder 50 shown in FIG. 6, the plasma enters the space or gap between the edge of the cut-out in the base plate of the substrate holder and the outer edge of the substrate. The entry of plasma becomes a problem when a bias voltage more positive than the sputter cathode voltage is applied to the substrate.
Since the support claws are normally formed of a stainless steel or other metal, electrons and negative ions from the plasma flow freely to the grounded parts of the substrate holder through the support claws (e.g., when the support claws are held at ground potential). The flow of charged particles out of the plasma in the vicinity of the support claws causes local plasma changes in the characteristics of the plasma, with the plasma variation occurring where the support claws are present. This local change in the plasma characteristics produces the observed localized variations in the magnetic characteristics of the film deposited on the substrate.
A study was performed by the inventors involving the application of a negative bias voltage to the substrate to draw positive ions from the plasma for use in processing of the substrate. In the study, the supporting claws acted as electrodes for applying the negative bias voltage to the substrate. This study confirmed that when plasma enters into the gap between the substrate edge and the base plate, the characteristics of the plasma are significantly changed by the presence of the support claws, and the unwanted localized variation of magnetic characteristics of the type shown in FIG. 9B will occur. This has a detrimental effect on the data storage ability of the affected region of the disk, and acts to reduce the overall storage capacity of the disk by reducing the usable area of the disk.
What is desired is a substrate holder that allows disposition of films with a uniform quality over the entire surface of a substrate, i.e., without the localized variation of characteristics which arise from the presence of the support claws which are found in the prior art.

Substrate holder for reducing non-uniform film characteristics resulting from support structures


A dry etching method for a conductive material layer is disclosed. The dry etching method has the steps of: forming an oxygen-containing antireflection film on a surface of a conductive material layer; forming a patterned mask layer on the antireflection film; forming a sidewall protection film on a sidewall of the mask layer; and etching the conductive material layer using the mask layer having the sidewall protection film formed thereon. The sidewall protection film is formed after the antireflection film is patterned using the mask layer. The antireflection film is patterned after the sidewall protection film is formed, with the sidewall protection film left on the sidewall of the antireflection film. The sidewall protection film is formed by using at least one of sulfur based compound and sulfur nitride based compound. The antireflection film is composed of an SiON based material. The conductive material layer is composed of a material selected from the group consisting of a polycide film, an Al based alloy material layer, a Cu based alloy material layer and a refractory metal layer. The conductive material layer is formed on a semiconductor substrate having an insulating film formed on a surface thereof. The conductive material layer is formed on an insulating film having a barrier metal layer formed on a surface thereof.

1. Field of the Invention
This invention relates to a dry etching method adapted for fine processing of manufacturing a semiconductor device, and particularly to a method for preventing regression of a resist mask formed on an SiON based antireflection film so as to improve anisotropy.
2. Description of Related Art
In order to realize large scale integration of semiconductor devices, the minimum processing size of the circuit pattern formation has been rapidly diminished. For instance, the minimum processing size of the 16M DRAM of approximately 0.5 .mu.m (half micron), the minimum processing size of the 64M DRAM of 0.35 .mu.m (sub-half micron), and the minimum processing size of the 256M DRAM of 0.25 .mu.m (quarter micron) are required.
This increasingly fine processing depends largely upon a technique of photolithography to form a mask pattern. Visible to near ultraviolet rays, such as g rays having a wavelength of 436 nm or i rays having a wavelength of 365 nm, of a high pressure mercury lamp are used for the current 0.5-.mu.m class processing, and far ultraviolet rays, such as KrF excimer laser lights having a wavelength of 248 nm, are used for 0.35 to 0.25-.mu.m class processing. In the photolithography technique for forming a fine mask with a ray width of not greater than 0.4 .mu.m, an antireflection film to weaken a reflected light from an underlying material layer is substantially required for preventing reduction in contrast and resolution due to halation and standing wave effect.
As the component material of the antireflection film, amorphous silicon, TiN and TiON are conventionally used. However, since it has been shown that SiON (silicon oxide nitride) exhibits satisfactory optical properties in the far ultraviolet region, application of SiON to the excimer laser lithography is proposed. It is exemplified by a process of fine gate processing with an SiON film restraining the reflectivity of a W (tungsten)--polycide film or an Al (aluminum) based material film.
Meanwhile, after the patterning of the resist mask by such photolithography is finished, the antireflection film is etched in the subsequent etching process.
In this case, such a problem is now being apparent that the anisotropic shape of the underlying material layer may be deteriorated by oxygen discharged from SiON in the etching process, particularly in overetching. This problem is explained with reference to FIGS. 1 to 4.
FIG. 1 shows a state of a wafer prior to the etching, in which a gate SiO.sub.x film 22, a W-polycide film 25 and an SiON antireflection film 26 are sequentially stacked on an Si substrate 21, with a resist mask 27 patterned in a predetermined shape being formed thereon. The W-polycide film 25 is composed of, from the bottom, a polysilicon layer 23 containing impurities and a WSi.sub.x (tungsten silicide) layer 24 which are sequentially stacked.
If the W-polycide film 25 is etched using a Cl.sub.2 /O.sub.2 mixed gas, the etching is promoted by a formation of etching reaction products, such as SiCl.sub.x and WClO.sub.x. On the other hand, a carbon based polymer derived from decomposition products provided by forward sputtering of the resist mask is deposited to form a sidewall protection film 28 on the sidewall surface of the pattern. If the wafer temperature is sufficiently low, SiCl.sub.x of relatively low vapor pressure among the etching decomposition products can be a component of the sidewall protection film 28.
As a result, a gate electrode 25a of anisotropic shape is formed at the end of just etching, as shown in FIG. 2. In FIG. 2, materials after the etching are denoted by their respective original numerals plus subscripts "a".
However, if the overetching follows the just etching, regression of the edge of the resist mask 27 causes the SiON antireflection film 26a to have its end surface tapered to be easily exposed, as shown in FIG. 3. SiON, having an element composition ratio of approximately Si:O:N=2:1:1, is richer in Si than SiO.sub.2 is. Consequently, SiON has low durability to a Cl based plasma, and easily discharges active O* when its exposed end surface is etched. Then, O* removes the sidewall protection film 28 in the form of CO.sub.x, to lower sidewall protection effects. In addition, since the W-polycide film 25 to be etched is reduced in the overetching, a relatively excessive amount of O* is present in the etching gas.
As a result, a gate electrode 25b having an undercut is formed, as shown in FIG. 4. The material layers having the undercut denoted by their respective original numerals plus subscripts "b". The undercut is generated most conspicuously in the WSi.sub.x layer 24b. Since O* sputtered out from the end surface of the SiON antireflection film removes W atoms in the form of WClO.sub.x, the etchrate in the WSi.sub.x 24a is increased.
As the anisotropic shape of the gate electrode is thus deteriorated, serious problems rise, such as, the metallization resistance falling off the designed value and difficulty in forming the sidewall to attain an LDD structure.
The deterioration in the anisotropic shape in the overetching is not limited to the above-described SiON antireflection film, but is a phenomenon which may be generated in cases where an antireflection film capable of easily discharging oxygen is used and where conductive material layers of Al based metallization and the like other than the W-polycide film are used as etching targets.


A portable and personal exercising device that may be stored and transported as a kit of intermatable components, then readily assembled and removably secured to a hinged door of a structure. The kit essentially comprises three telescopically engaging cylindrical members, where a pair of the members mount pulleys, a sliding weight member for vertical movement along the mated cylindrical members, and a cable in cooperation with the pulleys sliding weight member to effect such vertical movement by the person seeking exercise.

This invention is directed to the field of portable exercising devices, more particularly to a personal exercising device that may be readily assembled and disassembled, and placed in a kit or convenient carrying case for easy transport.
The present invention relates to a personal and portable exercising device that may be conveniently transported to different sites by the easy disassembly thereof and placed in a carrying case. As is known, various types of exercising devices are popular in today""s society. In recent decades, as the awareness of the importance of cardiovascular and muscle training has risen, so too has the demand for increased and improved excercise equipment. While gyms and health clubs typically offer a variety of sophisticated and expensive equipment, such clubs are often undesirable because of distance from the user or high membership fees. And, even those who are members of such a facility do not always have the time or energy to visit the club, even when a workout is desired or needed. Further, the public has become more aware that consistent and intelligently applied exercise can lengthen life span, overcome physical dysfunction and provide other related advantages.
Exercising the muscles of the body to increase the strength, muscle size and fitness of an individual by lifting free weights or by using a system of cables and pulleys to lift weights is one of the types of known portable exercising devices. It was found that free weights were cumbersome, created storage problems, can be noisy, damaging to floors and walls, and are heavy limiting portability and increasing shipping cost. The development of devices that used springs or elastic bands to provide the resistance to muscle contraction eliminated the problems inherent with handling heavy weights, but created new problems and were limited to one point of resistance further limiting versatility in types of exercises capable of being performed.
The prior art, as reflected in the following U.S. patents, illustrate and describe a number or personal or portable exercising devices, namely:
a.) U.S. Pat. No. 5,871,424, to Connor, teaches an exercise apparatus having a clamping means for securing the apparatus to a conventional door, at least one elastic resistance band and a flexible resistance harness. The resistance harness includes a pair of arm slings made of a thin, relatively wide fabric material formed in a closed loop and defining an opening therethrough. The resistance harness further includes a connecting strap made of a thin, relatively narrow fabric material and having opposed ends. The opposed ends of the connecting strap are attached to the pair of arm slings such that the arm slings are connected by the connecting strap. The resistance harness further includes a chest strap made of a thin, relatively narrow fabric material and having opposed ends. The opposed ends of the chest strap are attached to the pair of arm slings opposite the connecting strap. The exercise apparatus is compact and lightweight and thus is convenient for individuals who travel frequently to use, transport and store. In a preferred method of using the exercise apparatus, a user extends the upper arms through the arm slings of the resistance harness and pulls the resistance harness using the abdominal muscles in the direction of the pelvis while bowing the lower back outwardly to extend the resistance band. Thus, the spine is elongated and all of the abdominal muscle groups are contracted without placing undue stress on the muscles in the lower back.
b.) U.S. Pat. No. 5,820,529, to Weintraub, relates to a dual operational exercise resistance device that is usable in the home or fitness center by attachment to a supporting structure. The supporting structure can be a freestanding platform base, a wall, or a door. The device can be utilized to replace the weight stack in a universal gym or any exercise machine. The device can be utilized to provide resistance from more than one point of attachment for standard exercise grips. In addition the resistance provided by the device is easily adjustable, providing the appropriate resistance for the particular muscle group being exercised. The device comprises a base that is configured for attachment to a support or exercise machine, a lever arm member having a peripheral edge being pivotally attached to the base having a pulley on end, two pulleys on opposite ends of the base being pivotally mounted on a horizontal axis within vertically orientated mounted brackets and a pulley being pivotally attached to an intermediate point on the base. One end of the lever arm member is attached to a pivotally mounted pulley to which a portion is engaged by a cable and extends therefrom in two directions for attachment to a grip at two alternate locations. To the other end of the bar attached a resistance mechanism that attaches pivotally to an intermediate point on the base. This structure reduces the resistance force produced by the resistance mechanism as the exerciser approaches full contraction of the muscle group being exercised to insure a completely full contraction is made. The device also compensates for the use of a non-linear resistance mechanism.
c.) U.S. Pat. No. 5,766,118, to Connor, describes an exercise apparatus that includes a clamping means for fixing the apparatus to a vertical surface such as a door or a wall, an elastic resistance band and a resistance harness. In a preferred embodiment, the clamping means includes a lag screw having a hook portion adjacent one end. One end of the resistance band is attached to the hook portion of the lag screw and the other end is attached to the resistance harness. In another preferred embodiment, the exercise apparatus further includes an adjustment means for adjusting the vertical location of the resistance harness relative to the clamping means, and the clamping means includes a U-shaped Bracket. The adjustment means includes a belt having one end attached to the U-shaped bracket, and the free end threaded first through an adjustment buckle and then through a hook attached to one end of the resistance band. The other end of the resistance band is attached to the resistance harness. In a preferred method of using the exercise apparatus, a user extends the upper arms through an opening defined by the resistance harness and rotates the upper body about the pelvis while pulling the resistance harness in the direction of the pelvis using the abdominal muscles to extend the resistance band. In another preferred method, the user pulls on the resistance harness in the direction of the pelvis using the abdominal muscles to extend the resistance band without rotating the upper body about the pelvis. Thus, the spine is elongated and all of the abdominal muscle groups are contracted without placing undue stress on the muscles in the lower back.
d.) U.S. Pat. No. 5,468,205, to McFall et al., discloses an exercise apparatus having a pair of pulley support units mounted on a door by straps which vertically encircle the door. The support units are interconnected by a series of elastic bands, such as bungee cords that run vertical paths between the support units. The ends of the bands or cords are wrapped around pulleys and terminated such that a handle may be attached to each of the cords at either the top unit or the bottom unit. Various exercises are possible with one or two arms or legs by pulling on the cords with the handle. The apparatus is easily mounted or dismounted from any door or other vertically oriented and fixed-in-place partition and is small enough to fold and store in a small carrying case.
e.) U.S. Pat. No. 4,747,594, to Houde, is directed to a portable exercise device for use in a doorway, and includes a base with a pair of arms pivotally connected thereto for rotation between a vertical storage position and a horizontal position in which they engage the sides of the opening. Additionally, adjustable brackets on the outer ends of the arms are provided for centering and securing the base in the opening; a central, multi-section post for mounting in a sleeve on the base and for connection to a top bracket for securing the top of the post to the top of the opening. Further, a pair of multi-section columns for mounting in sockets on the base and connection to the top brackets are provided with a pair of spring assemblies connected to the base and slidable on the columns; and pulleys mounted on the top ends of the columns and near the bottom end of the posts. Finally, a cable extends around the pulleys to seat which is slidably mounted on a bar, one end of which is removably mounted in a socket on the base, the bar extending outwardly from the post.
A daily or regular regimen of exercising is extremely important to one""s health. However, one further disadvantage with traditional personal exercising devices, such as those of the prior art, particularly in today""s mobile society, is the inability or difficulty in transporting the devices when one must be away from home or office where the devices are typically used. As a consequence the regimen is broken. This is comparable to one taking a break from one""s dietary schedule. Obviously, the intended results of such schedule may never be reached. The present invention comprises a portable device that allows the user to readily transport the device so that the chosen exercising regimen may be continued at home, office, vacation or a trip. This is accomplished by a unique device that can be readily assembled, disassembled, and transported in a convenient carrying case of the component parts. The manner by which this invention achieves the goals hereof will become apparent in the description which follow, particularly when read in conjunction with the accompanying drawings.
The present invention teaches a personal and portable exercising device that comprises plural intermatable components for easy assembly and mounting to a door, then disassembled for packing and storing in a convenient carrying case or kit for transport to another location and set up to be used again.
The device hereof comprises a first cylindrical, elongated component mounting at a first end a U-shaped hook for removably overriding the top of a door, for example, a diametrically reduced second end, and an adjustable pulley member along the elongated member. A second or intermediate component thereof is a cylindrical member having a first end for telescopically engaging the reduced diametrical second end of the first cylindrical component, a second diametrically reduced second end, and a sliding weight member capable of sliding movement along the lengths of the first and second components through a manual effort by the user thereof. A third and final component comprises a cylindrical member for telescopically engaging the second diametrically reduced second end of the intermediate component, where said third component mounts a pair of pivotal arms, at which at least one said arm is adjustable for removably securing to opposing sides of the door, and a bracket mounting a pulley. Finally, the device includes a manually movable cord having a free end secured to the sliding weight member via the respective pulleys. By adding to or releasing weights from the sliding weight member, the user can readily develop an exercising regimen for daily or regular use, and to maintain same whether at home, office, trip or vacation.
Accordingly, an object of this invention is to provide an exercising device that may be readily assembled and disassembled for use at the pleasure of the user wherever desired.
Another object hereof is the provision of a kit of components forming the exercising device of this invention, where the disassembled device may be readily transported to different locations by the user to ensure the maintenance of a regular exercising regimen irrespective of where the user may be.
A further object of the invention is an exercising device that can be easily and removably attached to a hinged door of a structure.
These and other objects of this invention will become more apparent, particularly to those skilled in the art, in the description and drawings which follows.


There are provided a method for heat treatment, a heat treatment apparatus, and a heat treatment system capable of efficiently controlling heat treatment such as a bright treatment with high precision and without causing oxidation and decarbonization. Computation of ΔG0 (standard formation Gibbs energy) is performed by referring to sensor information from respective sensors, and an Ellingham diagram, a control range, and a status of the heat treatment furnace in operation expressed with ΔG0 are displayed on a display device 531, while a flow rate of hydrocarbon gas is controlled by a control unit 534 so that ΔG0 is within the control range.

For heat treatment of metal, various heat treatments have conventionally been used depending on application purposes, the heat treatments including a standardization treatment such as annealing/normalizing, a hardening/toughening treatment, such as quenching/tempering and thermal refining, and a surface hardening treatment, such as nitriding and surface improvement. While these atmosphere heat treatments are performed in atmosphere gases, such as atmospheric air, inert gases, oxidizing gases, and reducing gases, which are supplied to a heat treatment furnace, the properties of metals that are subjected to the heat treatments are drastically changed by components of these atmosphere gases. Accordingly, it is necessary to control the components of the atmosphere gases supplied into the heat treatment furnace with sufficient precision and to visualize the status of the atmosphere in the furnace with high precision.
As a first conventional technology that performs feedback control on the flow rate of the gas supplied to a heat treatment furnace in response to a signal coming from an oxygen potentiometer placed inside the heat treatment furnace, a method of adjusting the atmosphere gas in a bright annealing furnace disclosed in Patent Literature 1 (Japanese Patent Laid-Open No. 3-2317) will be described with reference to FIG. 1. In FIG. 1, exothermic converted gas is supplied from an exothermic converted gas generator 11 to a gas mixer 13 via a dehumidifier 12, while hydrocarbon gas is supplied from a hydrocarbon gas feeder 14 to the gas mixer 13 via a flow control valve V1 so that the hydrocarbon gas is mixed with the exothermic converted gas.
The mixed gas is heated and combusted at high temperature (1100° C.) in a gas converter with heating function 15, and then the gas is quenched and dehumidified in a gas quenching/dehumidifier system 16, before being supplied to a bright annealing furnace 17. Oxygen partial pressure is measured by the oxygen potentiometer 18 provided inside the bright annealing furnace 17, and based on this measurement value, carbon potential (CP) is calculated by a carbon potential computation controller 19. Then, the calculated value is compared with a preset carbon content in an object to be treated, and the flow rate of hydrocarbon gas supplied to the gas mixer 13 is feedback-controlled via the flow control valve V1 so that the calculated value is matched with the preset carbon content. This prevents oxidation and decarbonization of the material to be treated in the bright annealing furnace 17.
Next, as a second conventional technology, a method of controlling furnace gas in bright heat treatment disclosed in Patent Literature 2 (Japanese Patent Laid-Open No. 60-215717) will be described with reference to FIG. 2.
In FIG. 2, an oxygen analyzer 22 detects the partial pressure of residual oxygen in a heat chamber 21. When the detection value is higher than a set value set in an oxygen partial pressure setting unit 24, hydrocarbon gas and reducing gas are supplied to the heat chamber 21, whereas when the detection value is lower than the set value, oxidizing gas such as air is supplied to the heat chamber 21 so as to control the amount of residual oxygen to be constant.
A carbon monoxide analyzer 23 also detects the partial pressure of residual carbon monoxide in the heat chamber 21, and when the detection value is higher than a set value set in a carbon monoxide partial pressure setting unit 25, inert gas, such as nitrogen, is discharged to the outside of the furnace while being supplied to the heat chamber 21, so that the amount of residual carbon monoxide is controlled to be constant. As a consequence, even when moisture, oxides, and oil and fat adhere to the surface of metals to be treated, the bright treatment is implemented without causing oxidation, decarbonization, carbon deposition, and carburization.
Now, as a third conventional technology, a method and an apparatus for heat treatment disclosed in Patent Literature 3 (U.S. Pat. No. 4,521,257) will be described with reference to FIG. 3.
In FIG. 3, a regulator 38 calculates CP in each of a carburization chamber 35, a diffusion chamber 36, and a soaking chamber 37 based on detection values of oxygen sensors 32, 33, and 34. The calculated values and respective CP set values are compared, and openings of respective flow rate valves are adjusted so as to control each supply flow rate of enrich gas supplied to each of the chambers.
Moreover, there is provided a sequencer 39 that controls the process in a carburizing treatment device, the sequencer 39 being configured to execute a command to cause the regulator 38 to stop and/or resume PID adjustment in accordance with the status of the carburizing device. Accordingly, during a heat treatment period including the time of opening an opening of the furnace, the CP is controlled to be constant.
Next, as a fourth conventional technology, a method and an apparatus for preventing coloration of a plate passing through reducing atmosphere furnace disclosed in Patent Literature 4 (Japanese Patent Laid-Open No. 11-80831) will be described with reference to FIG. 4.
In FIG. 4, the bright treatment is performed on a stainless steel 41 in a bright annealing furnace 42 having a color difference meter 45 provided on an outlet side. A control device 46 adjusts the circulating amount in a refining device 44 and the concentration of H2 supplied from a reducing gas supply device 43, so that a difference signal between an output signal of the color difference meter 45 and a reference signal falls within a control range. This makes it possible to manufacture uniform metallic materials with a stable coloration state.
As a fifth conventional technology, a method of calculating heat treatment conditions by using an Ellingham diagram to reduce metal oxide to metal is disclosed in Patent Literature 5 (WO 2007/061012).

Method for heat treatment, heat treatment apparatus, and heat treatment system


In the case where an object to be ground is ground by mounting a horizontally elongated jig onto a grinding head and by bringing the object into contact with a grinding surface of a grinding disk being driven and rotated, the attitude of the grinding head is controlled by an adjust ring that is in surface contact with the grinding surface of the grinding disk while moving the grinding head, the horizontally elongated jig holding thereon the object that has a plurality of thin film magnetic heads arrayed thereon. Thereby, the flatness of the object is improved and variations in the throat heights of many magnetic heads formed on the object to be ground are reduced by allowing the attitude of the object to be controlled with a grinding surface of a grinding disk as a reference.

1. Field of the Invention
The invention relates to a magnetic head grinding method and an apparatus for grinding an object that has a plurality of magnetic heads arrayed thereon.
2. Description of Related Art
In a conventional batch type process for manufacturing thin film magnetic heads for use in disk drive devices of computers, an object to be ground has many converting portions including magnetic thin film arranged in a single array on a ceramic bar that will become sliders while cut into pieces, so that the throat heights of the gaps of the converting portions can be set to values optimized for reading and writing data signals.
In the case where the throat heights of magnetic heads are set to appropriate values during the grinding process, there is a problem that a ceramic bar, which is an object to be ground, is distorted and has therefore undesirable bends. That is, if the ceramic bar has distortions and bends, the ceramic bar cannot be ground uniformly by the grinding disk of the grinding apparatus. Therefore, there is a likelihood that the throat heights of thin film magnetic heads on both end portions of the ceramic bar will be so large or so small that the magnetic heads on both end portions become defective even though the throat heights of, e.g., thin film magnetic heads in the middle of the ceramic bar are proper.
To overcome this problem, a magnetic head grinding apparatus disclosed in U.S. Pat. No. 5,620,356 is designed so that a ceramic bar is ground by correcting bends thereof while measuring resistances that are varied in accordance with the throat heights of a plurality of thin film magnetic heads arrayed on the ceramic bar. As a result, the throat heights of the respective thin film magnetic heads formed on the ceramic bar can be set to proper values.
By the way, the conventional grinding apparatus such as proposed by U.S. Pat. No. 5,620,356 is constructed so that an object to be ground having many converting portions including magnetic thin film arranged in a single array on a ceramic bar is attached to the bottom surface of a platelike, horizontally elongated jig and that such horizontally elongated jig is further mounted onto a back plate disposed on the apparatus side. However, such conventional grinding apparatus imposes a problem that the attitude of the back plate having the horizontally elongated jig mounted thereon is not set with the grinding surface of the grinding disk as a reference. For example, in the case where the back plate is initially set vertical assuming that the grinding surface of the grinding disk is horizontal, the fact that the grinding surface is out of horizontality affects the accuracy with which to grind the object (the flatness of the grinding surface is reduced, and variations in throat height are increased, etc.).

Magnetic head grinding method and apparatus


A design support apparatus including: a flow analyzer for analyzing a flow of thermosetting resin injected into a resin filling cavity to mold a resin mold product made of the thermosetting resin, using a finite difference method or a finite element method; a residual strain calculator for calculating residual strain (or stress) of the thermosetting resin after heat shrinkage of the thermosetting resin injected into the resin filling cavity to mold the resin mold product; and a strength analyzer for analyzing strength of the resin mold product, using a finite element method. According to this arrangement, strength of the resin mold product made of the thermosetting resin can be predicted accurately.

As a system for supporting designing of a resin mold product (such as a diode package) made of thermosetting resin, there are known a flow analysis system and a strength analysis system. The flow analysis system utilizes a finite difference method or a finite element method, to analyze a flow of resin. The strength analysis system utilizes a finite element method to analyze strength of a resin mold product. Conventionally, there exist various methods of flow analysis and strength analysis. Such a method is disclosed in Japanese Laid-open Publication Nos. H07-334484 and H06-187321.

Design support apparatus and method for supporting design of resin mold product


An image processing system and method includes selecting a color desired by a user, extracting a partial image corresponding to the color desired by the user and selected from a bit-map image, converting the partial image into vector data, storing the vector data in a memory, and setting the converted vector data as vector data to be processed as desired by the user. The image processing system and method further includes calculating a palette color from the bit-map image, extracting a partial image corresponding to the palette color, converting the partial image into vector data per color object, storing the vector data in a memory, and setting, as vector data to be processed as desired by the user, vector data per object that is selected from the vector data stored in the memory based on the color selected from the calculated palette colors.

1. Field of the Invention
The present invention relates to an image processing technique for converting a bit-map image having a plurality of colors into vector data.
2. Description of the Related Art
Paperless offices are now becoming common as environmental problems draw more attention. Image processing systems capable of achieving a paperless office system are now becoming commercially available. For example, in one system, a scanner is used to scan paper documents, and then the scanned data is converted into portable document format (PDF) for storage. An example of such a system is disclosed in Japanese Patent Laid-Open No. 2002-91949 (corresponding US patent Application Publication No. 2002/0087602 A1).
Japanese Patent Laid-Open No. 9-289586 (corresponding U.S. Pat. No. 6,389,162 B2) discloses another system. To enhance the efficiency of encoding in the transmission and storage of image data, noise occurring in the background of an image to be processed is removed, and the color of characters and figures is automatically quantized. The characters are then character coded in optical character recognition (OCR), and the figures are vectorized. This technique disclosed in Japanese Patent Laid-Open No. 9-289586 enhances the coding efficiency of an image by automatically quantizing color.
However, a user may wish to extract only a desired colored portion of an image for efficiency purposes. It is known that many conventional image processing systems are unsuitable for this task.
For example, the user may wish to first scan and reuse an examination sheet that has been graded or corrected with a red pen. The problem and answer sections of the examination sheet will typically be marked-up with the red pen. To reuse the examination sheet data, the problem portion must be extracted without the answer section and without portions marked-up in red. If the image is merely segmented into rectangular area for each object, the problem and marked-up section are extracted together without separation.

Image processing apparatus, image processing method, program, and storage medium


An apparatus for obtaining tool face angles on a rotating drill collar in substantially real time is disclosed. In one exemplary embodiment the apparatus includes a magnetoresistive magnetic field sensor deployed in a tool body. The apparatus further includes a programmed processor configured to calculate tool face angles in substantially real time from the magnetic field measurements. The programmed processor may optionally further be configured to correlate the calculated tool face angles with logging while drilling measurements for use in borehole imaging applications.

Wireline and logging while drilling (LWD) tools measure physical properties of the formations through which a borehole traverses. Such logging techniques include, for example, natural gamma ray, spectral density, neutron density, inductive and galvanic resistivity, acoustic velocity, acoustic calliper, downhole pressure, and the like. Formations having recoverable hydrocarbons typically include certain well-known physical properties, for example, resistivity, porosity (density), and acoustic velocity values in a certain range. In some logging applications it is desirable to determine the azimuthal variation of particular formation properties (i.e., the extent to which such properties vary about the circumference of the borehole). Such information may be utilized, for example, to locate faults and dips that may occur in the various layers that make up the strata. Tools capable of producing azimuthally sensitive information on formation properties are typically identified as imaging tools.
Downhole imaging tools have been available in wireline form for some time. Such wireline tools typically create images by sending large quantities of circumferentially sensitive logging data uphole via a high-speed data link (e.g., a cable). Further, such wireline tools are typically stabilized and centralized in the borehole and include multiple (often times one hundred or more) sensors (e.g., resistivity sensors) extending outward from the tool into contact (or near contact) with the borehole wall. It will be appreciated by those of ordinary skill in the art that such wireline arrangements are not suitable for typical LWD applications. In particular, communication bandwidth with the surface would typically be insufficient during LWD operations (e.g., via known telemetry techniques) to carry large amounts of image-related data. Further, LWD tools are generally not centralized or stabilized during operation and thus require more rugged sensor arrangements.
Several attempts have been made to develop LWD tools and methods that may be used to provide images of various circumferentially sensitive sensor measurements related to borehole and/or formation properties. Many such attempts have made use of the rotation of the BHA (and therefore the LWD sensors) during drilling of the borehole. For example, Holenka et al., in U.S. Pat. No. 5,473,158, discloses a method in which sensor data (e.g., neutron count rate) is grouped by quadrant about the circumference of the borehole. Kurkoski, in U.S. Pat. No. 6,584,837, and Spross, in U.S. Pat. No. 6,619,395, disclose similar methods.
In prior art methods, conventional flux gate magnetometers are utilized to determine the tool face angle of the LWD sensor (which, as described in more detail below, is often referred to in the art as sensor azimuth) at the time a particular measurement or group of measurements are obtained by the sensor. While flux gate magnetometers (also referred to in the art as ring core magnetometers) can be used in borehole surveying applications, such magnetometers have some characteristics that are not ideally suited to imaging applications. For example, flux gate magnetometers typically have a relatively limited bandwidth (e.g., about 5 Hz). Increasing the bandwidth requires increased power to increase the excitation frequency at which magnetic material is saturated and unsaturated. In LWD applications, electrical power is often supplied by batteries, making such power a somewhat scarce resource. For this reason, increasing the bandwidth of flux gate magnetometers beyond about 5 Hz is not practical in many LWD applications. Flux gate magnetometers, therefore, are not well suited for making substantially real-time tool face angle measurements in many LWD settings. There exists a need for sensors and/or sensor arrangements that are suitable for making such real time tool face angle measurements.
Flux gate magnetometers are sensitive instruments requiring careful calibration and handling. Though magnetometers have been used in many LWD and MWD tools, these instruments present design challenges that add to the complexity and expense of the tools. The magnetometers are also relatively expensive, which further compounds this problem. A need exists, therefore, for a more simple, more rugged, and lower cost means for providing substantially real-time azimuthal information in LWD imaging applications.
Moreover, AC and/or DC power is often routed through a drill collar (e.g., from a turbine or a battery pack) to an LWD sensor. The magnetic field about the electrical transmission line is known to interfere with nearby magnetometers. While AC fields may be filtered in certain applications, DC fields are particularly difficult to accommodate. There also exists a need for an arrangement suitable for routing electrical power past magnetic field sensors deployed on a drill collar.

Measurement tool for obtaining tool face on a rotating drill collar


The present invention provides a method of manufacturing a pattern with a flattened surface and a droplet jetting device which can provides the pattern with a flattened surface. A droplet jetting means of the present invention comprises a droplet jetting means having a plurality of nozzles arranged in each row, each of the plurality of nozzles has a plurality of discharge ports aligned in an axial direction, and diameters of the discharge ports for the plurality of nozzles differ from row to row. According to one aspect of the present invention, a droplet jetting means including a plurality of nozzles arranged in two rows with a plurality of discharge ports aligned in an axial direction in each row, comprising steps of: forming a first pattern by jetting a composition through the plurality of nozzles in the first row; and forming a second pattern by selectively jetting the composition through the plurality of nozzles in the second row, wherein discharge amounts the composition jetted from each of the plurality of nozzles aligned in the first row and the second row differ from each other.

1. Field of the Invention
The present invention relates to a droplet jetting device using a droplet jetting means which comprises a plurality of nozzles with discharge ports aligned in an axial direction. Further, the present invention relates to a method of manufacturing a pattern and a method of manufacturing a wiring by droplet jetting.
2. Description of the Related Art
In recent years, pattern formation by means of droplet jetting (ink jetting) has been applied to flat panel display technology and actively developed. The droplet jetting has various benefits of maskless because of direct-write technique, easy application into a large-sized substrate, high material efficiency and the like. Therefore, the pattern formation by means of the droplet jetting has been applied to fabrication of electrodes and the like for an EL layer, a color filter, and a plasma display.
When a pattern having a relatively large size such as a pixel electrode etc. is formed by droplet jetting, a plurality of liquid droplets is continuously jetted. However, this technique may cause unevenness on a surface of the pattern.
A semiconductor device using a transistor formed over an insulator has been widely applied to a large-sized liquid crystal display device as well as a portable terminal such as a cellular phone, and also has been developed actively. High integration and miniaturization of the semiconductor device have been carried out for the purpose of improving its performance. In many case, the distance between elements provided in the first layer has been narrowed and plural wirings have been laminated thereon to highly integrate the semiconductor device. According to the development of a multilayer wiring in which plural layers are laminated, the planarization technique for flattening the surface of the wiring so as not to generate unevenness thereon has been increasingly important.

Droplet jetting device and method of manufacturing pattern

Semiconductor Energy Laboratory Co., Ltd.


Systems and methods are disclosed to manage a microgrid with a hybrid energy storage system (HESS) includes deriving a dynamic model of a bidirectional-power-converter (BPC)-interfaced HESS; applying a first neural network (NN) to estimate a system dynamic; and applying a second NN to calculate an optimal control input for the HESS through online learning based on the estimated system dynamics.

The development of microgrid technologies featuring renewable distributed energy resources (DERs) have brought new opportunities as well as challenges to conventional distribution systems. Meanwhile, hybrid energy storage system (HESS), e.g., combination of batteries and ultra-capacitors, are deployed to compensate the intermittency of renewable DERs and participate in the real-time demand-supply accommodation, which also helps to defer the extraordinary cost of updating the conventional power grids. This unveils a completely new path to alternate the traditional operation pattern of power systems, which creates significant benefits and convenience for both power suppliers and customers. Currently, HESS consisting of lithium-ion batteries (LIB) and ultra-capacitors (UC) have been widely incorporated in microgrids. However, the discrepancies of energy and power densities result in the disparate dynamic inertias between LIB and UC. Therefore, proper real-time control of HESS with promising transient performance becomes a challenging problem.
In a microgrid with a hierarchical control structure, the state of charge (SOC) of energy storage unit (ESU) can be decided by the centralized tertiary control and realized by distributed secondary/primary control. In the charging process, ESU works as a load bank, while in the discharging process, it performs as a DER. For the rest of time, ESU should be isolated from the system to avoid continuously repeated charging and discharging (C&D) caused by the self-discharging effect. Nevertheless, due to the low inertia of microgrids, the initializing and switching C&D processes for ESU may lead to nuisance disturbances, especially in fast C&D scenarios. The unexpected disturbance significantly degrades the power quality and might damage sensitive loads, such as data centers. It may even trigger false protection schemes under the worst scenarios. This disobeys the original purpose of implementing HESS. Therefore, the desired control policy should provide a smooth C&D solution for HESS in a decentralized manner with plug & play capability.
Conventionally, constant current (CC) and proportion-integration (PI)-based controls are two of the most popular methods in industrial applications. CC control has been widely used in low voltage electronic devices such as cellphone and laptop due to its implementation simplicity. However, the starting and terminating of the CC controller will introduce significant voltage disturbances, which is harmful to microgrids. From this perspective, PI-based control methods can slightly improve the transient performance, since large disturbances are introduced only during the initializing periods of C&D. Even though, PI-based methods generally require excessive parameter tuning efforts and rely on the awareness of system dynamics. Once system parameters deviate from the original set point, e.g., due to aging or heating issues, the performance of PI-based controllers will significantly degrade. Additionally, in practice, the outer voltage loop of double-loop PI controller is usually simplified as a proportional (P) controller to avoid over-C&D, which also limits the performance of PI-based controllers. A common issue is that PI-based algorithms introduce considerable disturbances to the system during C&D processes.

Optimal charging and discharging control for hybrid energy storage system based on reinforcement learning

Geiri Co Ltd, State Grid Jiangxi Electric Power Co, State Grid Corp of China SGCC, GEIRINA


An embodiment relates to a method for operating a three-phase machine including a rotor and a stator connected to a three-phase network. The stator is connected to the three-phase network via a first semiconductor circuit arrangement for forming a first rotational field rotating in a first direction of rotation in the stator and via a second semiconductor circuit arrangement for forming a second rotational field rotating in a direction of rotation opposite to the first direction of rotation in the stator. The three-phase machine further includes a controller. The method includes controlling, via the controller, semiconductors of the first and second semiconductor circuit arrangement to accelerate the rotor by current pulses of both the first rotational field and second rotational field in the first direction of rotation.

A three-phase machine can in principle be operated as an electric generator or as an electric motor. The former converts mechanical energy into three-phase current, the latter three-phase current into mechanical energy. Three-phase motors are classified according to IEC standard 60034 in terms of their efficiency into various efficiency classes IE 1 to IE 4 (IEC=International Electrotechnical Commission; IE=International Efficiency). Not all defined efficiencies for electric motors can be easily maintained using the asynchronous machine, especially in the lower power range up to 20 kW, which is why the use of permanent magnets in the rotor is increasingly sought, for example, as a permanent-magnet synchronous machine (=PMSM).
FIG. 1 shows a schematic representation of such a permanent-magnet synchronous machine in an embodiment as a revolving field machine having a stator St which comprises stator windings having winding strands for the three phases of a three-phase network. In this case, the stator windings are electrically connectable to the three phases of the three-phase network via phase terminals A, B, C. The synchronous machine also has a rotor L (also called an armature or pole wheel) in the interior of the stator St, which rotor comprises a magnetic north pole N and a magnetic south pole S and is mounted rotatably about a rotation axis R. The illustration in FIG. 1 is to be understood as merely example and has no limiting effect on the scope of protection the claimed subject matter. If the three-phase current in the stator windings passes through a full time period, the magnetic field of the stator St continues to rotate one full pole pitch (one north and one south pole). With two pairs of poles in the stator, this corresponds to a mechanical rotation of 180 degrees. Since magnetic poles can only occur in pairs, the smallest pole pair number is p=1 (a north pole and a south pole). The number of poles is adequately 2 p. A 4-pole machine thus has 2 pole pairs, that is, the pole pair number p=2. The rotational speed of the stator field in a motor having two pole pairs is only half of that in a motor having only one pole pair, although the frequency of the feeding current does not change. The pole pair number p of the motor, motors commonly having one to four pole pairs, thus determines the rotational frequency of the stator field and thus the rotational speed or rotational frequency of the rotor, which follows the magnetic field in the stator. The rotation frequency of the rotor decreases with increasing pole pair number.
Although the machine type PMSM enables high energy efficiency, the start and operation on the rigid network are not easily possible. To enable this, a damper cage can be provided in the rotor of the machine. Although the damper cage enables a safe startup on the rigid network, the combination of the flows of damper cage and permanent magnet leads to high starting currents.
Likewise, operation on a suitable power electronic actuator, such as a frequency converter (=FU) or soft starter, is possible. In particular, the use of a soft starter, represents a cost-effective solution for starting up a PMSM on a "rigid network", that is, on a three-phase network using a fixed network frequency. Measures to limit the power when switching on an electrical device, for example, an electric motor, are referred to as a soft start. In conventional soft starters for asynchronous machines, the electrical voltage applied to the motor is reduced when the motor is switched on and slowly increased to the full network voltage, for example, via phase angle control. However, this method is not suitable for starting PMSM.
The dissertation of Dr. Marcel Benecke, University of Magdeburg, 2012, entitled "Anlauf von energieeffizienten Synchronmaschinen mit Drehstromsteller" presents a solution for starting up the permanent-magnet synchronous machine on a soft starter. The method presented in this work, however, requires the current polar wheel angle of the machine, so that the motors used for this work had to be equipped with a corresponding encoder system. An encoder is understood as meaning rotational speed and position encoders which detect the mechanical variables rotational speed and position of the pole wheel, that is, of the rotor. Their signals are required to supply the controllers with actual values and to close the existing rotational speed and position control loops. The rotational speed and position signals also serve as an important input variable for the current control loop for the vectorial control methods in three-phase drives. In this case, the encoder detects the rotational speed and/or position directly on the motor shaft.
The encoder system negatively affects the cost and availability of the system, which currently makes a soft starter solution unattractive for highly efficient motors. For these reasons, a method for starting up without an encoder is preferred.
A method for starting up without encoder is known, for example, from WO2018/086688A1 (Siemens AG) May 17, 2018. In this case, the rotor is rotated from a known initial position with a maximum torque via ignition of thyristors, a voltage induced by the rotation of the rotor is measured, and an optimum ignition angle of the synchronous machine is determined. This method enables the machine to start without a rotary encoder system, but provides for a pre-start orientation of the rotor. Such a method without encoder for aligning a three-phase machine is described in WO2018/072810A1 (Siemens AG) Apr. 26, 2018.
The difference between the electrical network rotational speed, corresponding to a grid frequency of the three-phase network of usually 50 Hz or 60 Hz, and the motor rotational speed decreases with increasing motor rotational speed. This has the consequence of the difference angle Δ_φ between the electrical network angle φ_grid and the motor angle φ_mech also changing slowly.
FIG. 2 shows a contour diagram of the maximum possible mean torque M_mean, in the following also referred to simply as the mean torque M_mean, as a function of the network angle φ_grid and the motor angle φ_mech when selecting the optimum ignition time of the thyristors, which is determined by the algorithm of the Benecke method which is described in the above-mentioned dissertation by Dr. Benecke. The illustration in FIG. 2 relates to an example motor having a pole pair number of p=2. The motor has reached its maximum rotational speed at an motor rotational speed of 25 rps=1500 rpm, and the rotor is running synchronously with the network. Isolines are shown at the values 7, 14 and 21 Nm. The darkest regions shown in FIG. 2, also referred to as "torque valleys", in which the mean torque M_mean is less than 7 Nm, are less useful for an acceleration of the motor, since a small positive torque is achievable here; they also include those regions in which the torque M_mean is negative or the current would be greater than a predetermined current limit, that is, where an ignition of the thyristors definitely makes no sense. A current limit, which defines a maximum permissible current, is used for energy efficiency and protection of the electrical components.
The regions shown in white in FIG. 2, also referred to as "torque peaks", in which the mean torque M_mean is greater than 21 Nm, are optimally suited for an ignition of the thyristors in order to accelerate the motor effectively: the possible torque is at maximum in the white regions. The regions lying between them, that is, the light gray regions between 7 and 14 Nm and the even lighter regions between 14 and 21 Nm, are such that they are better suited for an acceleration of the motor, the greater the mean torque M_mean achievable therein.
The time course of network and motor angle during startup of the motor is illustrated in FIG. 2 as a dotted line Z; the time course is illustrated by the arrows on the dotted line Z. This is merely a schematic representation of a time segment which disregards deformations of the dotted line Z through acceleration processes in order to explain the relationships as clearly as possible. If the dotted line Z reaches the maximum value 360 degrees on the scale of the electrical network angle φ_grid, the course is continued at the minimum value 0 degrees on the scale of the electrical network angle φ_grid: this is indicated by the two vertically downward pointing arrows in FIG. 2. As long as the rotational speed of the rotor is just below the synchronous rotational speed, here: 1500 rpm, the network and motor angle, as illustrated by the dotted line Z in the range of the motor angle φ_mech=0 to about 130°, runs in the isolines of 14 and larger. A positive torque contribution can be achieved on a sustained basis here by ignitions. With further increasing rotor rotational speed, however, the line Z, starting from motor angles of φ_mech=approximately 130°, slowly moves into a region in which positive torque can no longer be achieved. The rotational speed drops again here. t1 marks the beginning of the phase in which positive torque can no longer be achieved.
This situation has the consequence that the soft starter, at motor rotational speeds close to the synchronous network rotational speed, here: 1500 rpm, finds fewer and fewer possibilities for the ignition of the thyristors and inserts ever longer breaks between pulse blocks. During this time, the system is in a "torque valley" of FIG. 2, and the ignition algorithm waits until it encounters a "torque peak" of FIG. 2 again.
FIG. 3 shows a diagram describing the startup of a PMSM with a current strength-time curve and a ω_mech-time curve, wherein the magnitude of the current I of the stator phases is plotted in the unit amperes and the mechanical angular speed ω_mech of the rotor is plotted in the unit min-1 over time in units of seconds. In addition, the ignition times 30 of the thyristors are indicated on the x-axis, which, if they take place in quick succession, form so-called pulse blocks 32. In the time range between t=1.5 s and t=2 s, it can be seen that pulse blocks 32 formed by a cluster of ignition times of the thyristors cause a significant acceleration of the rotor, that is, an increase of the mechanical angular speed ω_mech. The pulse blocks 32, that is, a clustered ignition of thyristors to generate a positive torque, correlate with a torque peak in FIG. 2. Analogously to this, a pulse pause 31, that is, a lack of a pulse block 32, correlates with a torque valley in FIG. 2.
The pulse pauses 31 between the pulse blocks 32, which become ever longer at motor rotational speeds close to the synchronous network rotational speed, lead to a so-called "rotary speed ripple" during startup of a motor on a soft starter, that is, a ripple of the mechanical rotational speed ω_mech, which is clearly visible in the time range in FIG. 3 between t=1.5 s and t=2 s.

Method for operating a three-phase machine


An on-chip voltage regulator for controlling a gate of a regulator transistor having a first terminal coupled to receive an external power supply voltage and a second terminal coupled to provide a regulated voltage level to an internal circuit formed on a chip on which the on-chip voltage regulator is formed. The on-chip voltage regulator includes circuitry for detecting when a high current load to which the second terminal of the regulator transistor is coupled is activated. A control transistor is provided having a first terminal coupled to receive the external power supply voltage, a second terminal coupled to the gate of the regulator transistor, and a gate responsive to the means for detecting. In operation, a control voltage with an overshoot portion having preselected duration is generated on the gate of the regulator transistor in response to the activation of the high current load.

1. Field of the Invention
The present invention relates, in general, to integrated circuits and, more particularly, to integrated circuits having voltage regulator circuits generating an internal power supply voltage from an external power supply voltage.
2. Relevant Background
Integrated circuits (ICs) comprise thousands or millions of individual devices interconnected to provide desired functionality. Significant effort is expended to improve processing techniques so as to reduce the size of each individual device in order to provide greater functionality on a given IC chip at reduced cost. In general, smaller geometry devices operate faster with less power than do larger geometry devices. As device geometries are reduced the breakdown voltages of the devices and the isolation that separates the devices decreases also.
Electronic systems usually comprise ICs manufactured with a variety of technologies. This has created a need for multiple power supply voltages to be supplied to a single printed circuit board to support the various types of devices on that board. For example, many complementary metal oxide semiconductor (CMOS) devices are still available that minimum drawn dimensions of more than 0.8 microns and require a power supply voltage of 5.0 volts. In contrast, state of the art ICs such as microprocessors and memory circuits have gate lengths in the order of 0.35 microns and require a power supply voltage of 3.3 volts or lower.
To ensure a broad market for a particular IC, it should be compatible with commonly available power supply voltages for other IC's. A practical solution to this disparity is to provide voltage regulator circuitry integrated with the low voltage ICs that decreases the higher voltage (e.g., 5.0 V in the above example) to the lower voltage required by the small geometry device (e.g., 3.3 V). Hence, it is necessary to regulate the externally supplied power supply voltage inside of each of the small geometry ICs.
A conventional on-chip voltage regulator is designed to generate a lower voltage than the external voltage. Typically, a transistor is coupled in series between the external voltage node and the internal voltage supply node. The conductivity of the transistor is modulated to drop the excess voltage across the transistor. To limit undesirable voltage ripple on the internal voltage supply node, the time constant of the regulator is desirably much longer than the internal cycle of the device. This prevents undesired voltage ripple within a cycle that can upset analog voltage levels. Because of this, the internal voltage supply node should be heavily filtered by coupling a large capacitor between the internal voltage supply node and ground. In practice, however, filter capacitors consume a great deal of chip area without adding functionality. Cost and chip size considerations dictate limiting the filter capacitor to more modest sizes.
The limited capacitor size reduces the charge storage capability of the regulator and makes it more sensitive to high current demand by downstream circuits and devices. An example of such circuitry are sense amplifiers in a dynamic random access memory (DRAM). In a typical DRAM circuit, one sense amplifier is supplied for each bit line pair in the device. For each sense amplifier, the stand-by (i.e., non-switching) state requires relatively little current. When activated, however, each sense amplifier may draw more than 1000 times its standby current. As used herein, the term "activated" means a state in which a circuit is drawing high current whereas "stand-by" means a state in which a circuit draws little current even though power is applied. Moreover, state of the art DRAM devices may have more than 1000 sense amplifiers activated simultaneously, resulting in very high current draw on the regulator. During high current demand, regulation can become poor and the chip's internal voltage levels can vary significantly. It would be desirable to bypass the internal regulator altogether during these high current demand operations.

Fast voltage regulation without overshoot


Output data points of a digital FIR filter are calculated by storing input data points in an addressable memory and accessing the addressable memory to supply a new input data point exactly once for each output data point after a first output data point and storing each input data point in a first recirculating memory for so long as that input data point is needed to calculate a next output data point. The input data points stored in the first recirculating memory are used to calculate output data points. Furthermore, coefficients are stored in a second recirculating memory and are used to calculate the output data points. As a result, only one memory access is required per output data point.

1. Field of the Invention
The present invention generally relates to digital filters and, more particularly, to a Finite Impulse Response (FIR) filter.
2. State of the Art
In conventional practice, computations involved in realizing a FIR filter have been memory access intensive. One data output point of a FIR filter is calculated as ##EQU1## and a succeeding output data point is calculated as ##EQU2## where A.sub.i is one of a series of coefficients defining a windowing function of the filter and X.sub.i is one of a series of input data points.
FIG. 1 shows a known system for performing the foregoing computations. In the system, the coefficients A.sub.i and the input data points X.sub.i are stored in a random access memory 11. The RAM 11 is addressed by an address generator 13 to output corresponding A.sub.i and X.sub.i to a multiplier 15 to form the product A.sub.i X.sub.i. The product A.sub.i X.sub.i is input to either an adder 17 or, in the case i=1, to an accumulator register 19 through a multiplexer 16. When i.noteq.1, the previous sum ##EQU3## stored in the accumulator register 19 is added to the current product A.sub.i X.sub.i in the adder 17 and the cumulative result is stored in the accumulator register 19 through the multiplexer 16. After the sum of the N products has been accumulated in the accumulator register 19, the contents of the accumulator register 19 is output as an output data point. In practice, the coefficients A.sub.i may either be fixed in the case of a non-adaptive filter or may be varied between the calculation of output data points in the case of an adaptive filter.
The system of FIG. 1 requires the address generator 13 to generate 2N addresses per output data point despite the fact that of the 2N operands involved in the calculation, only one of the operands, a new input data point, may differ from the operands involved in the previous calculation. For sophisticated filtering applications, the RAM 11 and its associated address generator 13 normally are so large (in terms of chip area) that they must be located on chips separate from the remainder of the FIR filter circuitry. In such cases, access time for the RAM 11 can be prolonged because of the need to drive the longer interconnect lines. For real-time applications, overcoming these delays requires the use of fast, expensive, and power-hungry logic.


An integrated power module having a depletion mode device and an enhancement mode device that is configured to prevent an accidental on-state condition for the depletion mode device during a gate signal loss is disclosed. In particular, the disclosed integrated power module is structured to provide improved isolation and thermal conductivity. The structure includes a substrate having a bottom drain pad for the depletion mode device disposed on the substrate and an enhancement mode device footprint-sized cavity that extends through the substrate to the bottom drain pad. A thermally conductive and electrically insulating slug substantially fills the cavity to provide a higher efficient thermal path between the enhancement mode device and the bottom drain pad for the depletion mode device.

There are at least three standard methods of packaging multi-chip power modules. One popular method incorporates direct bonded copper (DBC) substrates that comprise a ceramic tile with copper bonded to top and/or bottom sides of the ceramic tile. Alumina (Al2O3), aluminum nitride (AlN), and beryllium oxide (BeO) are materials that are usable as the ceramic tile. DBC substrates are known for their high thermal conductivity and excellent electrical isolation. DBC substrates comprising AlN and copper have a thermal conductivity of at least 150 Watts per meter Kelvin (W/mK). However, DBC substrates have disadvantages of high cost, large design rules, and a limitation of only one electrical conductor routing layer.
Another multi-chip packaging method utilizes leadframe technology with either DBC isolation or a cascode-stacked die technique. However, present leadframe technology not well suited for multiple die structures that are coplanar. In particular, present leadframe technology can be compromised thermally and/or mechanically when attempted to be used for coplanar multi-chip structures.
Yet another standard multi-chip packaging technology incorporates laminate printed circuit board (PCB) technology. An advantage of laminate PCB technology is low cost, integration flexibility, and electrical conductor routing. However, a significant disadvantage of PCB technology is low thermal performance if there are multiple dies requiring high power dissipation that cannot utilize electrically conducting thermal vias due to unequal electrical potentials on both sides of the vias.
What is needed is an integrated power module with improved electrical isolation and improved thermal conductivity that is structured to realize the advantages of each of the above multi-chip packaging methods while avoiding the discussed limitations of those methods.

Integrated power module with improved isolation and thermal conductivity


An incidence area of a light flux controlling member according to the present invention includes a fresnel lens part, an outermost lens part, and a reflector holding part. The fresnel lens part includes a first protrusion that has a first incidence surface, a first reflection surface, and a first ridge line. The outermost lens part includes a second protrusion that has a second incidence surface, and a second reflection surface. A reflector holding part holds a reflector.

In recent years, from the viewpoints of energy conservation and miniaturization, light emitting devices using light emitting diodes (hereinafter also referred to as "LED") as light sources, (LED flashes), have been used as light emitting devices for imaging cameras. As the light emitting devices described above, a light emitting device in which an LED and a fresnel lens are combined is well known.
Typically, the shape of an imaging area of an imaging camera is quadrangular. Therefore, in order to obtain a sharp captured image, the light emitting device preferably illuminates an area to be irradiated quadrangularly. Therefore, a fresnel lens to be used for the light emitting device for an imaging camera is required to uniformly and efficiently irradiate the quadrangular area to be irradiated with light emitted from a light emitting element. Also to date, various fresnel lenses have been proposed for illuminating a quadrangular area to be irradiated (see, e.g., PTL 1).
FIG. 1A is a perspective view of fresnel lens 10 disclosed in PTL 1. Fresnel lens 10 illustrated in FIG. 1A can perform the same function as that of cylindrical lens 20 illustrated in FIG. 1B. As illustrated in FIG. 1A, fresnel lens 10 disclosed in PTL 1 includes a plurality of concentric grooves 12 whose shape in plan view is rectangular which are spaced apart from each other.

Light flux controlling member, light emitting device and illumination apparatus


A push button assembly has a button retainer having drawer slide guides and a corresponding bezel structure. The button retainer also has a surface perpendicular to a principal translational axis, on which is one of a conical protrusion and a conical indentation is formed. The bezel structure has the other of the conical protrusion and conical indentation. The conical indentation mates with the conical protrusion such that the conical protrusion and the portions forming the conical indentation are in contact around their perimeters when the button retainer and bezel structure are in a pre-load position. A method of producing the button retainer and bezel structure is also disclosed, which includes attaching an attachment mold pin to the molds, which can be altered and reattached in the tuning process.

1. Field of the Invention
This invention relates to a push button assembly, and more particularly, a push button assembly having drawer slide guides.
2. Description of Related Art
Push buttons are used to control a wide variety of electronic equipment, including electronic equipment within automobiles. Examples of such uses are buttons for audio applications, driver's information applications, climate control, four-wheel drive activation/deactivation, door switches, and seat movement applications, to name a few.
Push buttons having a transparent or translucent display portion on the front surface are known in the art. These types of push buttons have a light guiding portion, called the button retainer, extending from the back of the push button and extending through a bezel structure. Often, multiple drawer slide guides protrude from the side of the button retainer in order to control friction and wobble.
Button retainers and bezel structures of the type herein are generally made of plastic and injection molded from steel molds. In order to minimize both the friction between the button retainer and the bezel structure and the wobble of the button retainer within the bezel structure, the button retainer and corresponding bezel structure must meet accurate tolerances. Often, as friction is decreased, wobble increases, and vice versa.
In addition to controlling friction and wobble, button design also involves maximizing the lightable area, minimizing the gap between the button retainer and the bezel structure, ensuring adequate button travel, and maximizing the durability of the button assembly. Attempting to satisfy all of these design parameters causes a button to become over-constrained.
A bezel structure is often tuned to fit a button retainer by a process that involves cutting the mold for the bezel structure to one side of a predetermined tolerance band, leaving gaps for the drawer slide guides of the button retainer. Next, the bezel structure is injection molded, and the button retainer is fit within the bezel structure. Measurements are made for adjusting the bezel mold to fit the button guides to accurate tolerances. Then, the bezel mold is re-cut or material is added to the bezel mold. Tuning the multiple drawer slide guides in three dimensions along multiple axes is difficult to control and difficult to package, especially now that bezel structures are designed with computers.
In view of the above, it is apparent that there exists a need for a button retainer and bezel that meet design demands from both a friction and a wobble standpoint. Furthermore, there exists a need for a button retainer and bezel structure in which tuning the button retainer to fit within the bezel structure is easier to control and more accurate.


A depth-adjustable device for a chair comprises a rail rack, the railway is formed with a V-shaped concave, and the supporting board is slideably disposed in the railway by four clipping blocks, and in the lower part of each clipping block is formed a V-shaped convex. The inclined concave cooperates with the inclined convex to allow the adjustment device operate firmly. The V-shaped convex of the clipping blocks moveably abuts against the V-shaped concave in the bottom of the respective railways of the rail base, so that the gravity will be focused on the center and the supporting board and the rail base will slide relative to each other but will not wobble and impact each other, thus reducing the operation noise effectively.

1. Field of the Invention
The present invention relates to an adjustable device for a chair, and more particularly to a depth-adjustable device for a chair that is free of the problem of wobble and noise.
2. Description of the Prior Art
Since different modern designs are used more and more widely in various chairs, various chairs with different adjustment mechanisms, such as chair with pneumatic height-adjustment structure, and spring type recliner, etc, have come into existence in our everyday life.
For example, a conventional depth-adjustable device for an office chair is shown in FIGS. 1 and 2, wherein a supporting board 10 for supporting the chair body (not shown) is slideably mounted on a railway 111 of a rail rack 11. The rail rack 11 is fixed to the chair foot 12, and a rotating handle 13 is pivotally mounted on the rail rack 11 and has a protruded block 131 engaged in a tooth groove 101 in a side of the supporting board 10. However, this conventional depth-adjustable device still has the following problems:
Firstly, since the supporting board 10 is slideably mounted on the square-shaped railway 111 of the rail rack 11, it will cause the shift of the center of gravity of the user when the weight of the person and the chair are applied to the supporting board 10. And the gap in the square-shaped railways 111 will make the rail rack 11 keep impacting the supporting board 10, causing wobble, and even worse, the wobble may cause the disengagement of the supporting board 10 out of the railway 111 of the rail rack 11.
Secondly, the rotating handle 13 is pivotally mounted on the rail rack 11 and has a protruded block 131 engaged in a tooth groove 101 in a side of the supporting board 10. However, the protruded block 131 and the tooth groove 101 are square-shaped in cross section, there will be a gap A between the protruded block 131 and the tooth groove 101, and this gap will also cause the supporting board to wobble or to disengage from the railway 111 of the rail rack 11.
Thirdly, no matter the supporting board 10 impacts the rail rack 11 or the protruded block 131 impacts the tooth groove 101, it will cause noise.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.