A portable combination observation and hunting stand having a lower and middle ladder portion interconnected with each other with the middle ladder portion interconnected to a third, upper portion which comprises of a seat platform and an separate standing platform, all of which is abuttable to a tree or other support structure at a unique angle and is securely attached thereto by a chain or cable having a first end attached to the upper ladder portion at the end of the outer vertical upright then extending around the tree to a turnbuckle or load binder pivotally connected on the opposite side of the seat platform and adjustable according to the circumference of the selected tree or other support structure.

The object of the present invention is to provide a comfortable, light-weight and easily transported, quickly assembled for use and easily disassembled, by one person, elevated platform or seat from which to observe and/or hunt game and other wildlife as well as events such as sports, parades, etc.
Another object of the invention is to provide a portable observation and hunting stand that insures the maximum safety of the user by permanent all welded construction of the upper portion which comprises the seat platform and standing platform, the middle and lower portions, connection of upper section to tree or support structure by means of a chain or cable and turnbuckle or load binder, connection of middle section to tree or support structure by means of a stabilizer strap, securing of lower section by inserting tubular ends of lower section into the ground.
A further object of this invention is to provide a portable hunting and observation stand that employs any size tree or other support structure but will not harm or damage such tree or support structure.
The foregoing objects are realized as a lightweight, portable hunting and observation stand which includes a lower ladder section, a middle ladder section, and an upper ladder section which incorporates a standing platform and a seating platform.

Portable combination hunting and observation stand


A method for processing, analyzing live and off-line physical memory in order to determine the presence, and initiate the removal, of malware from the system. The internal structures within the host operating system, the drivers, and the user-space executables can be utilized to self-verify the integrity of the processes, their related structures, and the binary execution paths residing on the system. Additionally, these same characteristics are employed for use in comparison with other baseline malicious and benign datasets as well as datasets from live systems to automatically identify malware and remove it from a targeted computer system.

Current anti-virus (or the more general, "anti-malware") software systems are fighting a battle with malicious-intent software (i.e. "malware") that has previously been largely unwinnable. The current systems focus on inspecting and alerting upon known (or weakly deduced) methods that malware authors and developers are constantly tweaking. The capabilities of current anti-malware systems to dynamically change their inspection techniques (outside of simple signature updates) are limited once installed on a host computer system in the field. This limitation creates numerous false positives and false negatives. True run-time dynamic response to changing threats is not an advantage of current anti-malware software. These current anti-malware systems oftentimes function with only moderate success until they completely fail due to a disruptive technology that is introduced by the malware developers. Until this new disruptive technology is observed, reverse-engineered, and understood by the anti-malware developers, the anti-malware's triggers and subsequent counter-measures are bypassed.
Ultimately, anti-malware will continue to fail so long as it functions within the current paradigm. Two primary characteristics condemn anti-malware systems to failure. These characteristics are that it (1) operates in a known manner and (2) operates from within the same context as the malware. Anti-malware functions in a "known manner" because there are operating system "rules" that it must abide by in order to avoid interfering with healthy system operations, and in some cases, in order to be approved by the operating system's manufacturer. These rules do not have to be followed by malware and oftentimes, depending upon the malware's ultimate goal, are stretched to the functional limit. Anti-malware also operates from within the same context that the malware operates. The issue of context does not necessarily signal a horrible practice, it is arguable that this must occur at some level in the current paradigm. However, by combining that anti-malware toolsets operate in a largely known way, function with the same level of access and act upon the same objects and structures within the system, anti-malware has not been able to actively attack malware. This is because the anti-malware is trying to retain its integrity while attempting to discover malware characteristics.
A paradigm shift must take place in order to be able to detect and remove malware from a computer system. There must be a shift in the strategy of attacking malware from a different context by employing a dynamic system.
FIG. 10 is a simplified block diagram of a system 1000 including a target host computer system 1011 and an analysis host computer system 1012. In FIG. 10, the target host computer system 1011 includes a central processing unit (CPU) 1014, also known as a "processor." Central processing unit 1014 coacts with a non-volatile storage device, or hard disk drive (HDD), 1016 and with volatile memory 1018, sometimes known as Random Access Memory (RAM) or "physical memory," across the multiple logical and physical layers of the target host computer system 1011 in order to perform various processes, as known in the art. The processes may include those of an operating system, such as Microsoft Windows©, which are initially stored in HDD 1016, and loaded into RAM 1018 at startup or initialization. Other programs and processes stored on HDD 1016 may be initiated from time to time or at startup. These additional programs and their support files result in processes being loaded into RAM 1018. Central Processing Unit 1014 acts upon these programs' commands in order to facilitate interaction between the user (where applicable), desired target host computer system hardware (which includes the processor 1014, RAM 1018, HDD 1016, etc.), and the target host computer system operating system. The user may interact with target host computer system 1011 by way of a physical device connected to user interface 1023. The device attached to user interface 1023 may be a keyboard, mouse, voice command arrangement, or the like.
In addition to the processes associated with the operating system intentionally loaded into HDD 1016 of target host computer system 1011 of FIG. 10, and in addition to the various executable, ancillary, and data files, the volatile memory 1018 may contain one or more malware processes or paths of malicious code execution (such as injected or patched dynamic linked libraries (DLLs), functions, drivers, etc.). Various means by which malware can be introduced into computer systems are well-known, and include computer viruses, Trojan horses, rootkits, and the like. The modes of transmission may include any of the paths by which the target host computer system 1011 interacts with its environment, including network connections 1072 accessed by a network interface 1022, disk drives, and the like. However introduced, the malware processes and malicious code paths may become resident within volatile memory 1018 and be executed by the processor 1014. When resident only within RAM 1018, such malware can be countered by (a) "rebooting" the target host computer system 1011 to thereby halt power to the RAM 1018, which without power and under normal conditions will effectively clear the contents of RAM 1018 of any discernible execution paths, and (b) then re-loading the RAM 1018 with the benign or acceptable processes stored on HDD 1016.
Under some conditions, the malware processes may also become resident on HDD 1016 of target host computer system 1011. This by itself is not necessarily deleterious, as the malware may adversely affect the operation of the target host computer system 1011 only when it becomes resident in RAM 1018 where it can interact with the benign or acceptable processes. However, when the target host computer system 1011 is rebooted with malware resident on the HDD 1016, the malware is likely to be re-introduced into the RAM 1018. Under these conditions the malware can now persist on the target host computer system 1011 during periods when the RAM 1018 cannot maintain its state or the contents of its memory (e.g. when it loses power during events such a reboot or power cycle of the target host computer system 1011). In cases such as these, rebooting the target host computer system 1011 may not effectively deal with the malware infection. When malware is introduced into the volatile memory, it may become intermixed with or "infect" one or more of the benign, acceptable or, "good" processes.
Security programs, such as those provided by McAfee, Norton, Webroot, and others, are often used with computer systems to counter various types of malware, such as spyware and viruses. Such security programs are intended to monitor information introductions to the computer by many potential paths and to sequester information identified as malware, render it harmless, or at least to warn of the presence of malware.
It is well-known that the providers of security programs are at a disadvantage relative to the developers of malware. This disadvantage results from the difficulty of anticipating what new malware will arise, and the characteristics that might render the malware amenable to detection and countering. In effect, the malware protection available to the operator of a computer such as target host computer system 1011 of FIG. 10 "runs behind" the development of security countermeasures. Thus, there is always the possibility, if the target host computer system 1011 is made available for the introduction of information or data, that malware will be introduced. It is very desirable, considering the possibility that the security programs may be only partially effective, that the operator of the target host computer system 1011 of FIG. 10 allow only data from a trusted source to be introduced into the target host computer system 1011. While some anti-virus software might employ anomaly-based measures that the companies may claim will help detect "future" malware, these anomaly-based measures are simply rulesets which can be circumvented after careful study of the governing rules.
Notwithstanding the strict use of trusted information sources and faithful adherence to up-to-date security programs and practices, introduction of malware into computer systems is a fact of life. The introduction of malware can be highly deleterious, potentially allowing (a) the computer system to be taken over and used as part of a "botnet" (a network of malware components controlled from a command entity) for propagating malware or undesired communications (such as spam) to other computer systems, (b) revelation of sensitive personal data such as bank account numbers and passwords, and in the context of national security, loss or corruption of sensitive technical, strategic, or tactical information.
Malware, in order to perform its malevolent function when it infects a computer system, must be accessible by the CPU or similar processing unit located on the system—which typically means that it must be resident in RAM—at some point in its execution. Malware that takes up residence in RAM of a computer must have, by necessity, bypassed all of the identification steps mandated by the resident security program, or it must have been confirmed (even mistakenly) to run by the user of the computer system. The presence of malware may become obvious or be suspected due to untoward operation of the computer. The response is usually to run an anti-malware program in a "scan" mode in which all, or most, of the processes' address spaces in HDD and RAM are inspected for recognized patterns and/or behaviors. However, it may well be that the malware, having already escaped detection by the security program on its way to execution, may again escape detection during a scan or even ongoing examination by the security software. In some cases, malware, once executing, may attack the security software's ability to detect certain parts or capabilities of the malware. At this point there may be no remedy except to re-format the HDD 16 and re-load it with the acceptable or benign programs so as to be able to continue with its use.
Some malware may not make its presence known or suspected by refraining to adversely affect the appearance of normal operation. For example, a computer that has been acquired for a botnet may draw unwanted operator attention if the takeover gives overt indications, such as execution latency or catastrophic application or operating system failure. Thus, such malware attempts to hide its presence on the target host computer system. Since there is no overt indication of infection with malware, no countermeasures may be taken, and the infected target host computer system may continue to operate, apparently normally, except that it may "run" the benign programs and processes with increased, yet unnoticeable, latency, as some of its computing power is diverted to fulfilling its malicious tasks. Due to operating systems' behemoth size and inherent latency for non-malicious reasons, there often is little way for the operator to determine or notice any malware-attributable delay.
Increasing attention has lately been directed towards forensic examination of computer systems. United States patent application 2005/0204205, published Oct. 13, 2005 in the name of Ring et al. describes a method for finding malicious modules, processes, and system call patches in a computer system and restoring the system to an uncompromised state. In the method of the Ring publication, various analyses are performed, including system call table address correlation, module linked list address correlation, user space and kernel space process-view correlation, network port binding verification, and user and kernel space file-view correlation. These analyses are performed on each inspected host computer system and the comparisons are made with regards to a single host computer system. Ring's analyses state that "it senses anomalous operating system behavior when activity in the operating system deviates, that is fails to adhere to, a set of predetermined parameters or premises." Not all malicious software affects systems in ways detectable by Ring's analyses.
Current methods of detection by anti-virus and anti-malware entities are reaching a point of diminishing return, because the depth and breadth of inspection can only be so extensive before noticeable overhead is produced, resulting in usability and functionality issues that become unbearable for users.
Numerous methods can be used to analyze the physical memory of a target host computer system. Before analyzing the contents of the physical memory however, it must be captured, or acquired. There are two primary modes or times at which physical memory capture can occur, namely live and off-line. "Live" memory capture occurs on the target host computer system and runs in the context of that operating system. "Off-line" physical memory capture occurs when the target host computer system's physical memory is not in operation and the physical memory has been stored in a binary file (such as in the case of a paused VMWare image or a computer in a state of "hibernation"). This binary file is then moved from the target host computer system (e.g., target host computer system 1011 of FIG. 10) and is analyzed on another host computer system, such as analysis host computer system 1012 of FIG. 10. Access to "live" physical memory can be performed through introduction of physical hardware or through software-based methods, such as by employing Application Programming Interfaces (APIs), well-known in the art. The copying and transfer of the "off-line" physical memory binary file can be performed in several ways. The target host computer system way is through an application that uses Application Programming Interfaces (APIs) to access and copy the physical memory to a binary file. This binary file is simply an on-disk copy of what is stored in physical memory. In the binary file format, we can now treat it as any typical system file and copy, move, read, or edit the data. A second way is to obtain physical memory binary files that have been created by virtual machine technologies or by the target operating system, such as hibernation files. Moving the data from the target machine can be performed in numerous ways as well. Using any method, the data can be transferred, as by path 1073 of FIG. 10, from the target host computer system 1011 to the analysis host computer system 1012. Path 1073 can involve using human interaction and removable media (such as CDs, floppies, etc.), a direct link (such as a null modem), or a network connection such as 1072 in order to transfer the data to the analysis host computer system 1012.
Recent strategies for removing malware from memory have typically focused on removing injected data structures from linked lists or repatching binary code that has been changed by the malware. While these methods are sound, the areas that they typically address do not cover the full spectrum of malware-targeted methods. As malware detection becomes increasingly proficient, malware's methods of hiding itself from discovery improve. This improvement typically means diving deeper into the lower levels of the operating system or taking advantage of increasing levels of indirection. As described earlier, it is increasingly difficult to perform these inspections by anti-virus/-malware software during run-time execution of the applications due to the increased overhead operations cost. Improved apparatus and methods are desired for cleansing malware from computer systems.


In a tape loading device, a loading drive gear rotates about a shaft. The loading drive gear includes a U-shaped groove in which the shaft is disposed and a spring accommodating portion disposed continuously to the U-shaped groove. The first and second arms are rotated by the rotation of the loading drive gear, whereby sliders are moved along guide openings so as to wind a tape around a drum. When the tape has been loaded, the sliders are stopped by catchers. When the loading drive gear is further rotated, the shaft thereof is moved to the spring accommodating portion, and an energizing force is generated to a spring and exerted on the first and second arms in a direction where the sliders are pressed against the catchers. With this operation, the positions of the sliders are fixed so that the tape can stably travel. Since the spring is contained in the loading drive gear, the number of parts can be reduced as well as the tape loading device can be arranged simply and assembled easily.

This application claims benefit of Japanese Patent Application No. 2000-290922 filed in Japan on Sep. 25, 2000, the contents of which are incorporated by this reference.
1. Field of the Invention
The present invention relates to a tape loading device for loading a tape in a magnetic recording/reproducing apparatus such as a video tape recorder and the like.
2. Description of the Related Art
VTRs (video tape recorders) sometimes employ a front loading system for substantially horizontally loading a tape cassette from the front surface of a cabinet. In the front loading system, when the tape cassette is inserted into a cassette holder from the front surface of the cabinet, the cassette holder moves to a tape loading device and loads it on the tape loading device. When the tape cassette is set at a predetermined position, the tape in the tape cassette is pulled out by the tape loading device.
In a helical scan system, the tape pulled out from the tape cassette is wound around a drum. That is, the tape loading device includes a pair of tape pull-out members (hereinafter, referred to as xe2x80x9cslidersxe2x80x9d) that pass through the vicinity of an end of a drum from the vicinity of the tape cassette and move to the vicinity of the other end of the drum. The tape is pulled out by being hooked with the sliders and wound around the drum. With this operation, data can be recorded to and reproduced from the tape.
Each slider includes a guide roller rotatably mounted on a shaft having a flange, and an inclining post. As the sliders move, the tape is pulled out from the tape cassette while being in contact with the surfaces of the guide rollers and the inclining posts and travels by being guided by the guide rollers and the inclining posts.
FIGS. 1 and 2 are bottom plan views showing the back side of the chassis of a tape loading device as a related art of the above tape loading device.
A tape cassette (not shown) is transported by a cassette loading device (not shown) such that the tape take-out surface of the tape cassette is disposed at a position where it faces the peripheral surface of a drum (not shown).
A pair of guide openings 1 and 2 are formed through a chassis (not shown) from the vicinity of the position of a cassette holder at a time a tape cassette has been loaded to the vicinity of the front end of the drum through the vicinity of the rear end of the drum. The drum (not shown) is interposed between the guide openings 1 and 2. Sliders 3 and 4 for pulling out a tape are guided by the guide openings 1 and 2 and can slide from a position in the vicinity of the front end of the cassette holder to the rear end of the drum.
A guard panel on the front surface of the tape cassette opens in a process in which the tape cassette is inserted into a cabinet and loaded by the cassette loading device. On the completion of loading of the tape cassette, the guide rollers and the inclining posts of the sliders 3 and 4 are located inwardly of the tape in the tape cassette. When the tape cassette has been loaded, it is possible to pull out the tape from the tape cassette.
The sliders 3 and 4 move to the rear end of the drum along the guide openings 1 and 2 from the above state so as to pull out and load the tape. FIG. 1 shows a state in which the tape starts to be loaded.
Link mechanisms are mounted to ends of the sliders 3 and 4, and the rotation of a loading drive gear 7 is transmitted to the sliders 3 and 4 through the link mechanisms so that the sliders 3 and 4 are driven so as to slide along the guide openings 1 and 2.
That is, a pair of gears 5 and 6, which are meshed with each other, are rotatably disposed to the chassis between the guide openings 1 and 2. The gear 5 has a cut-out gear 14 disposed thereto coaxially, and a loading drive gear 7 is meshed with the cut-out gear 14. Thus, the gears 5 and 6 are rotated by the rotation of the loading drive gear 7.
The gears 5 and 6 have levers 8 and 9 fixed thereto and these levers 8 and 9 constitute link mechanisms, respectively. One ends of coupling members 10 and 11 are rotatably supported at the extreme ends of the levers 8 and 9 by means of shafts. The other ends of the coupling members 10 and 11 are rotatably supported by engaging portions 12 and 13 disposed at the rear ends of the sliders 3 and 4 by means of shafts.
The gears 5 and 6 are rotated in an opposite direction by the rotation of the loading drive gear 7, and the rotation of the gears 5 and 6 rotates the levers 8 and 9 about the rotational shafts of the gears 5 and 6. With this operation, the coupling members 10 and 11 connected to the extreme ends of the levers 8 and 9 are also moved, whereby the sliders 3 and 4 mounted at the extreme ends of the coupling members 10 and 11 are moved along the guide openings 1 and 2.
FIG. 2 shows a state before the completion of loading of the tape. The sliders 3 and 4 have locking portions 15 and 16 formed at the extreme ends thereof. The sliders 3 and 4 slide along the guide openings 1 and 2 until the locking portions 15 and 16 are abutted against catchers 17 and 18 fixed in the vicinity of the rear end of the drum disposed to the chassis. With this operation, when the tape has been loaded, the guide rollers and the inclining posts are located at predetermined stop positions in the vicinity of the rear end of the drum.
The positions of the sliders 3 and 4 must be fixed in a state in which the locking portions 15 and 16 thereof are abutted against the catchers 17 and 18 to permit the tape to stably travel while being wound around the drum. For this purpose, springs 19 are interposed between predetermined positions of the lever 8 and 9 and predetermined positions on the peripheries of the gears 5 and 6. The springs 19 energize the sliders 3 and 4 and move them in the directions of the catchers 17 and 18, that is, in a tape loading direction by further rotating and stopping the loading drive gear 7 after the locking portions 15 and 16 are abutted against the catchers 17 and 18. The energizing force of the springs 19 causes the catchers 17 and 18 to press the locking portions 15 and 16 so that the guide rollers are located at the positions regulated by the catchers 17 and 18.
The springs 19 must be provided to fix the guide rollers at the positions regulated by the catchers 17 and 18, which increases the number of parts, makes an assembly job such as a job for mounting the springs 19, and the like complicated and increases cost.
An object of the present invention is to provide a tape loading device capable of reducing the number of parts, simplifying an arrangement and making it easy to assemble the device.
A tape loading device of the present invention includes a loading drive gear; a pair of tape guides; coupling members for coupling the loading drive gear with the pair of tape guides and moving the tape guides between a loading start position and a loading terminating position by the rotation of the loading drive gear; and a pair of loading stoppers for stopping the tape guides at the loading terminating position, wherein the loading drive gear has a shaft supported by an elastic member, is located at a center in an ordinary state and is decentered by a force in a predetermined direction against the elastic force of the elastic member, and the tape loading device further includes a unit disposed to the coupling members and the loading drive gear for exerting a force in the decentering direction on the loading drive gear by further rotating the loading drive gear after the pair of tape guides are abutted against the loading stoppers, thereby exerting the elastic force generated by the elastic member on the tape guides abutted against the loading stoppers through the coupling members.
A tape loading device of the present invention includes a rotatable loading drive gear; first and second arms rotated by the rotation of the loading drive gear; a pair of tape guides coupled with the first and second arms, respectively and moved by the rotation of the first and second arms, respectively; a pair of loading stoppers for stopping the movement of the pair of tape guides at predetermined positions when a tape has been loaded; a first unit for generating a force by decentering the loading drive gear; and a second unit for exerting, when the tape has been loaded, the force generated by the first unit by decentering the loading drive gear on the first and second arms so as to press the pair of tape guides against the pair of loading stoppers.
Further, a tape loading device of the present invention includes a rotatable loading drive gear; first and second arms rotated by the rotation of the loading drive gear; a pair of tape guides moved by the rotation of the first and second arms, respectively; a pair of loading stoppers for stopping the movement of the pair of tape guides at predetermined positions when a tape has been loaded; a first unit for generating a force by decentering the loading drive gear; and a second unit for abutting the first and second arms against the loading drive gear by rotating the first and second arms to the loading terminating position to thereby decenter the loading drive gear, whereby exerting the force generated by the first unit on the first and second arms so as to press the pair of tape guides against the pair of loading stoppers.
The other features and advantages of the present invention will be apparent from the following description.

Tape loading device having an elastic member


A developer cartridge having a developer cartridge body with a fitting part is coupled to a developer supply path connected to a developing unit. A fitting part shutter unit is detachably mounted to the developer cartridge body and moved by an external force to move between a first position covering the fitting part and a second position expositing the fitting part.

1. Field of the Invention
The present invention relates to a developer cartridge for supplying liquid developer to a developing unit. The invention also relates to a liquid-type image forming apparatus including the developer cartridge of the invention.
2. Description of the Related Art
In general, image forming apparatuses are classified into dry-type image forming apparatuses using powdered dry developer and liquid-type image forming apparatuses using liquid developer. The dry-type image forming apparatus and the liquid-type image forming apparatus have their respective advantages and disadvantages. However, the liquid-type image forming apparatus can create high-resolution prints with higher contrast, compared to the dry-type image forming apparatus. Particularly, due to the increase in the widespread use of digital cameras, color prints with higher contrast should be produced more frequently. Accordingly the demand for color image forming apparatuses is expected to gradually increase.
The liquid-type image forming apparatus uses a developer cartridge to supply developer to a developing unit where the developer includes a mixture of a liquid carrier and a powdered toner of a predetermined color. Before the developer cartridge is attached to the image forming apparatus, the developer cartridge is previously filled with a developer having a predetermined color density. Accordingly, after the cartridge containing the developer runs out, the used cartridge is generally replaced with a new cartridge. Fitting units are provided for connecting the developer cartridge to the image forming apparatus in such a manner that the developer can be transferred between the developer cartridge and the developing unit. The fitting units enable the convenient replacement of the developer cartridge.
The fitting units may include a first fitting part connected to tubes for conveying and collecting developer connected to the developing unit, and a second fitting part connected to a developer supply opening portion and a developer collection opening portion of the developer cartridge, which are respectively coupled to the first fitting parts.
The first and second fitting parts may be respectively male and female fitting members that are complementarily coupled to each other.
In the structure described above, when the developer cartridge is attached to the image forming apparatus, the second fitting parts of the developer cartridge are coupled with the first fitting parts provided in the image forming apparatus.
However, according to the above-described structure, since the second fitting parts are exposed to the outside when the developer cartridge is attached to and detached from the image forming apparatus, user's hands may graze the second fitting parts. In particular, when the user detaches the developer cartridge from the image forming apparatus, the user's hands may be stained with some of the developer that is present on the second fitting parts.
Also, the second fitting parts exposed to the outside make an offensive appearance and can be stained or contaminated with dust, etc. during cartridge replacement.

Developer cartridge having a movable cover and liquid-type image forming apparatus


A method of processing X-ray images of a breast (B), the method comprising the steps of —generating (GEN3DV) a 3D volume from a plurality of X-ray images, —processing (DETMC) the 3D volume and/or the plurality of X-ray images, —computing (DETMC-CTR), for each region of interest in the 3D volume, a 3D characteristic position of the region of interest, —computing (CALCTGT) at least one needle target 3D position from a plurality of said computed 3D characteristic positions, —associating (SELIMG-TGT) each needle target position with a target image, —displaying (DISP-IMG) a slice image on a graphical interface, and —if the current slice image is a target image, displaying (DISP-TGT) on the graphical interface a target marker indicating each needle target position associated with the displayed current slice image.

Technical Field
Embodiments of the present invention relate to X-ray mammography and more particularly to assistance tools for carrying out an X-ray-guided breast biopsy.
Description of Related Art
Microcalcifications are tiny specks of mineral deposits (calcium) that can be scattered throughout the mammary gland or occur in clusters. Commonly, they simply indicate the presence of tiny benign cysts, but can signify the presence of early breast cancer.
Suspicious microcalcifications are commonly punctured thanks to biopsy, which is a medical test commonly performed by a surgeon or an interventional radiologist involving sampling of cells or tissues for examination.
Ultrasound guided biopsy is preferentially performed, as it is a non-irradiating modality, but micro calcifications are often hard to detect with such techniques. On the contrary, micro-calcifications are well detected with X-rays, and that is why mammography is used to puncture suspicious microcalcifications clusters.
Before sampling the radiologist has to select a target point of the breast. The middle of a notch is placed at the selected target point, after firing a biopsy gun.
Selecting the target point may be carried out thanks too many image acquisition techniques.
A conventional procedure for X-ray guided biopsy is stereotaxy. This procedure, which is mainly performed in the case of breast biopsy, comprises the acquisition of two stereo views taken at two different angles, usually +15°/−15°. With stereotaxy, the target point selection is generally done by selecting one point in each of the two stereo views. These points shall correspond to the target projection in the stereo images.
Another procedure for X-ray guided biopsy is digital breast tomosynthesis (DBT). This procedure is considered as potentially more efficient to guide breast biopsy than conventional stereotaxy, since it provides a 3D representation of the breast.
For DBT biopsy, the radiologist navigates though the 3D image acquired to select the target point. With DBT, to select the target point, the radiologist has to go up and down in the 3D volume and select the slice and the pixel to maximize the probability of getting micro-calcifications in the samples.
However, such navigation is very time consuming for the radiologist and thus may significantly increase the duration of the biopsy.
In addition, the target point selected by the radiologist may be approximate, especially when microcalcifications form multiple clusters in different regions of the breast.

Method of processing X-ray images of a breast


Supporting device, notably mattress, mattress support or supporting device for seats, comprising several elements comprising flexible fluid-holding chambers aligned vertically and assembled in a network so as to form a structure enabling a body to rest. The pressure in each fluid-holding chamber is transmitted insider first conduits (4) coming out of said chamber. The first conduits communicate this pressure to the fluid-holding chambers of the neighboring elements.

The present invention concerns mattresses, mattress supports for beds or seats, comprising a group of fluid-holding chambers that communicate their pressure.
In order to find a solution to the comfort inconveniences of traditional mattresses (latex, springs, foam) and of water mattresses, several constructions of fluid-holding beds have been attempted.
None meets fully the requirements of ease of assembly, advanced modularity, reduced space requirement, flexibility, hygiene and comfort.
It is an aim of the present invention to propose a mattress or mattress support for beds or seats that avoids the inconveniences of the prior art mattresses.
According to the present invention, this aim is achieved in particular through the characteristics of the independent claims. Further advantageous embodiments are moreover described in the dependent claims and in the description.
In particular, this aim is achieved by means of a mattress or mattress support for beds or seats comprising a group of fluid-holding chambers that transmit their pressure.

Supporting device, notably mattress, mattress support or for a seat


A method for use in a data processing system connected to a network in accordance with a data transfer protocol, the data processing system having one or more event queues for holding network events, and being capable of responding to interrupts issued in response to the presence of a network event in the data processing system by invoking a stack to cause processing in accordance with the data transfer protocol of network events on the event queues; the method comprising: deciding whether to permit the interrupts to be enabled, in dependence on the result of a determination as to the presence of current indications that the stack will be invoked by an entity in the data processing system to cause processing in accordance with the data transfer protocol of network events on the event queues.

The present invention relates to a method and system for processing data, and in particular it relates to processing data in accordance with a data transfer protocol.
FIG. 1 represents elements of a computer system capable of implementing a conventional protocol stack, such as a transmission control protocol (TCP) stack in a computer connected to a network. The computer system includes an application 101, a socket 102 and an operating system 103 incorporating a kernel 104. A network interface such as a network interface card (NIC) 106 is provided for interfacing between the computer system and the network. The socket 102 connects the application to a remote entity by means of a network protocol, in this example TCP/IP. The application can send and receive TCP/IP messages by opening a socket and reading and writing data to and from the socket, and the operating system causes the messages to be transported across the network via the NIC. One socket is typically provided for each network endpoint with which an application wishes to communicate. The application can invoke a system call (syscall) for transmission of data onto the network. Syscalls can be thought of as functions taking a series of arguments which cause execution of the CPU to switch to a privileged level and start executing the operating system. A given syscall will be composed of a specific list of arguments, and the combination of arguments will vary depending on the type of syscall.
Syscalls made by applications in a computer system can indicate a file descriptor (sometimes called a handle), which is usually an integer number that identifies an open file within a process. A file descriptor is obtained each time a file is opened or a socket or other resource is created. File descriptors can be re-used within a computer system, but at any given time a descriptor uniquely identifies an open file or other resource within the context of a process. Thus, when a resource (such as a file) is closed down, the descriptor will be destroyed, and when another resource is subsequently opened the descriptor can be re-used to identify the new resource. Any operations which for example read from, write to or close the resource take the corresponding file descriptor as an input parameter. A system call when invoked causes the operating system to execute algorithms which are specific to the file descriptor identified in the syscall.
In the context of networking, syscalls are used by applications to invoke a stack to send data, and to consume data that has been received, optionally blocking until more data arrives. In this context, a stack is a set of software and/or hardware resources that implement a collection of sockets. Other system calls are used for control plane operations such as creating and destroying sockets, connecting to remote endpoints, and querying the state of sockets.
In a typical network arrangement packets arriving at a NIC are delivered into buffers in host memory, and a notification is sent, in the form of a communication to the NIC's device driver in the operating system kernel. The communication channel by which this communication is delivered typically consists of a queue of notifications that may include notifications of other types of events, including successful transmission of outgoing packets. This communication channel is referred to in the following description as an event queue.
When network events are occurring in the computer system, at some point the device driver must process the event queue by inspecting each event notification and processing the received packets. It is desirable that this happen promptly, since undue delay in the processing of received packets may delay the progress of applications, or may cause the link to go idle. In conventional systems the processing of the event queue is invoked by way of an interrupt generated by the NIC at the time that the event is delivered to the event queue.
An interrupt causes the CPU to save the state of whatever process is currently running, and switch control to an interrupt service routine. This routine processes the event queue, and carries out network processing for the received packets. Thus network processing is carried out in a timely manner and at high priority in response to packet arrival.
A disadvantage of this mechanism is that interrupts incur high overhead due to the requirement to save and subsequently restore the state of the running process, and to interact with the hardware, and due to the impact on the memory caches in the processor.
It is widely known that performance can be improved by reducing the rate at which interrupts are invoked. One means by which this can be achieved is interrupt moderation, which imposes a minimum time gap between each interrupt. This may delay the processing of received packets slightly, but it means that the overheads of an interrupt are effectively spread over a larger number of event notifications.
Another means to reduce overheads due to interrupts is "Lazy Receiver Processing", discussed at http: (slash) (slash) www.cs.rice.edu/CS/Systems/LRP/final.html in an article entitled Lazy Receiver Processing: A Network Subsystem Architecture for Server Systems by Peter Druschel and Gaurav Banga. In this model interrupts are not enabled by default. Instead any outstanding event notifications in the event queue are processed when the stack is invoked by the application via a system call. Thus received packets are processed promptly provided the application invokes the stack frequently. When the application is blocked waiting to send or receive on a socket it is not available to process the event queue. To ensure that events will still be handled at this time, interrupts are enabled and the event queue is processed in the conventional way.
A problem with the Lazy Receiver Processing scheme is that if the process does not invoke the stack frequently, and is not blocked waiting for a socket, then the event queue may not get processed in a timely fashion. This can be resolved by providing a kernel thread that is able process the event queue from time-to-time as necessary, as described in the applicant's co-pending PCT application no. PCT/GB06/002202. However, this mechanism may not always be capable of implementation in a way that is both efficient and timely, partly because it involves the use of an additional thread competing with applications for CPU time.


A power supply unit includes a transformer, and outputs a first power supply voltage which is used for logic processing and a second power supply voltage which is used for driving a drive unit. A voltage control unit includes a shunt regulator to a detection voltage input terminal of which is connected a voltage which has been voltage divided from the first power supply voltage, and controls the second power supply voltage to a predetermined voltage value. And a voltage application control unit applies a voltage which is determined in advance to the detection voltage input terminal of the shunt regulator, when the replay unit is in a stopped mode where replay by the replay unit of data recorded upon the optical disk is stopped.

The present invention relates to an optical disk device which reads and replays data recorded upon an optical disk such as a DVD or the like.
Optical disk devices which record data upon recording media are per se generally known and popular. Such an optical disk device irradiates laser light upon the recording surface of the optical disk, and reads the data which is recorded upon this optical disk by detecting the reflected light. During replay, the optical disk device performs various types of servo control. Types of such servo control are rotational speed control of the optical disk (rotational speed control of a spindle motor), control of the condensation upon the recording surface of the optical disk of the laser light irradiated upon this optical disk (focus control), control of the irradiation of the laser light irradiated upon this optical disk upon the center of the track from which data is being read (tracking control), and the like. In such servo control, drive units such as the spindle motor, a thread motor, an actuator which supports an objective lens of a pickup head, and the like are driven. On the other hand, in a stopped mode in which replay of the data which is recorded upon the optical disk is stopped, these drive units are not driven. Due to this, the load upon the power supply which supplies operating power to the drive units is different in a replay mode in which data which is recorded upon the optical disk is being replayed, and in the stopped mode. Thus, if the output of the power supply which supplies operating power to the drive units is the same in the replay mode and in the stopped mode, then the circuit components which are connected to the output side of this power supply will generate heat in the stopped mode.
Furthermore, power supplies which vary their outputs in response to fluctuation of the load are described in Japanese Laid-Open Patent Publication H07-182056, Japanese Laid-Open Patent Publication H08-51772, and Japanese Laid-Open Patent Publication H09-311655.
However, a typical optical disk device is built so as to obtain a first power supply voltage which is used in logic processing and a second power supply voltage which is used for driving the above described drive units from an AC-DC power supply which employs a transformer. The first power supply voltage is taken off from an intermediate point of a coil of a transformer from which the second power supply voltage is taken off. The optical disk device employs a shunt regulator in order to control the second power supply voltage to a predetermined voltage. In concrete terms, a voltage obtained by voltage dividing the first power supply voltage is connected to a detection voltage input terminal of the shunt regulator, and the second power supply voltage is controlled to a predetermined voltage by this shunt regulator.
On the other hand, the load imposed by logic processing is the same in the replay mode and in the stopped mode. The load upon the first power supply voltage is approximately the same in the replay mode and in the stopped mode. With a prior art type optical disk device, there has been no structure for changing over the voltage which is inputted to the detection voltage input terminal of the shunt regulator in the replay mode and in the stopped mode. As a result, it has not been possible to change the second power supply voltage which is used for driving the drive units according to fluctuations of the load in the replay mode and in the stopped mode. Due to this, with a prior art optical disk device, in order to prevent generation of heat by the circuit components which are connected in the output line of this second power supply voltage, high priced circuit components of high rating with respect to generation of heat have been used, so that there has been a problem of high cost.
A feature of the present invention is to provide an optical disk device, with which, along with preventing generation of heat by the circuit components in the stopped mode, also a reduction in cost may be anticipated.


A method for preparing a biogenic guanidine complex, the method including: mixing dimethyl sulfoxide (DMSO) with water in a volume ratio thereof of 1:1 to yield a solvent DMSO-H2O; adding organic guanidine (G) and a compound MX2 in a molar ratio G/MX2=1:1 or 2:1 to the solvent DMSO-H2O, where the organic guanidine (G) is selected from arginine (Arg), guanidinoacetic acid (Gaa), creatine (Cra), creatinine (Cran), guanine (Gua), and agmatine (Agm); M represents Fe2+, Mg2+, or Zn2+; and X represents Cl−, CH3COO−, or CH3CH(OH)COO−; stirring the solvent DMSO-H2O containing the organic guanidine and the compound MX2; recycling the solvent DMSO-H2O through vacuum distillation and obtaining a solid; transferring the solid to a Buchner funnel, and washing the solid with deionized water and ethanol consecutively; and removing the deionized water and ethanol through vacuum filtration, and drying the solid. Biogenic guanidine complex can be used for production of Polyethylene terephthalate or Poly(ethylene isophthalate-co-terephthalate).

The disclosure relates to a method for preparing a biogenic guanidine complex, a method for preparing polyethylene terephthalate (PET), and a method for preparing poly(ethylene isophthalate-co-terephthalate)(PEIT).
Polyethylene terephthalate (also written poly(ethylene terephthalate)), commonly abbreviated PET, PETE, is a common thermoplastic polymer resin of the polyester family and is used in fibers for clothing, containers for liquids and foods, thermoforming for manufacturing, and in combination with glass fiber for engineering resins.
In the related art, the production of PET employs antimony such as ethylene glycol antimony or antimony trioxide as a catalyst. However, the antimony compounds are toxic to cells. Therefore, the PET products produced with an antimony catalyst pose a threat to the ecological environment and human health.

Method for preparing biogenic guanidine complex, method for preparing polyethylene terephthalate (PET), and method for preparing poly (ethylene isophthalate-co-terephthalate) (PEIT)


Disclosed is an anticorrosion paint for preventing steel materials from corrosion by using polyaniline as an anticorrosion pigment. The anticorrosion paint has an excellent anticorrosion effect, long persistence of the anticorrosion effect, high durability and superior coating property controlling the anticorrosion effect, without using metal causing environmental pollution as an anticorrosion pigment. Especially, in the anticorrosion paint, the top coat paint for improving the protection of the primer coat paint and the anticorrosion effect. The top coat paint includes 40 to 89 wt % of matrix resin, 5 to 54 wt % of colored pigment, 1 to 50 wt % of dopants and 5 to 54 wt % of mixed solvents, and the primer coat paint includes 3 to 49 wt % of the polyaniline, 40 to 86 wt % of the matrix resin, 1 to 47 wt % of the dopants and 10 to 56 wt % of the mixed solvents. The anticorrosion paint plays a role in exerting persistently the excellent anticorrosion effect without causing environmental problem.

The present invention relates to an anticorrosion paint which employs polyaniline as an anticorrosion pigment, so as to prevent the corrosion of metal materials, in particular, of steel materials. More specifically, the present invention relates to an anticorrosion paint, which can provide persistently excellent anticorrosion effect without using metal which causes environmental pollution.
As generally known in the art, the corrosion of metal materials including steel is a serious problem in various industrial fields. The corrosion of steel brings enormous loss in property and industry, and half of steel production is consumed in replacing the corroded steel structures every year. Various anticorrosion paints have been used to prevent the corrosion of metal materials, especially steel materials.
The above-mentioned anticorrosion paint is composed of metal, which is utilized as general anticorrosion pigment, and organic polymeric resins/inorganic resin which makes the metal to adhere to the surface of steel and protects coated object from corrosive environments. The anodizing forming type using Pb, Cr and the like, and the sacrificial anode anticorrosive type using Zn have been previously used as anticorrosion pigments.
However, the anodizing forming type anticorrosion pigments are classified as heavy metal, and so have the defect of causing another environmental problem at the time of elution, and the sacrificial anode anticorrosive type anticorrosion pigments exert an anticorrosion capability with an electrochemical sacrificial mode using the ionization tendency of the anticorrosion pigment, so have a defect of being unable to protect metal materials from corrosion for long period of time because the capability of the sacrificial anode anticorrosion decreases as the corrosion of sacrificial metals increases over time.
Since the rust of metal materials results from the action of air, water or carbon dioxide, the anticorrosion paints should perform two actions: to prevent them from contacting the surface of metal materials and block chemically the generation of the rust. A paint for primer coat should have particularly strong adherence to a metal basis and a paint for top coat should not permeate any air or water through the coating of paint, the low occurrence of cracking, high durability and high weatherability.
The oil based paints, which contain the mixed drying oil and the anticorrosion pigment, and the red lead paints, which contain the mixed red lead (Pb3O4) and boiled oil, are mainly used as anticorrosion paints. The anticorrosion paints that can substitute for the red lead paints comprise zinc powder, lead suboxide, basic zinc chromate (zinc yellow), or basic lead chromate (zinc chromide) pigments, in which the latter two pigments have a chemical anticorrosion effect. Besides, the anticorrosion paints may contain iron oxide, Bengala alone, or zinc yellow and red lead as combination pigments. As vehicles, those suitable for the primer coat or topcoat paints are used, and oil varnish and synthetic resin varnish as well as boiled oil are usually used. Recently, the paint, in which basic zinc chromate, phosphoric acid and butyral resin are dispersed into a mixed solvent of alcohol, ketone and water, is used for anticorrosive treatment of metal materials including aluminum, zinc or tin.
However, the prior anticorrosion paints as described above have problems such as the environmental pollution or low persistence of the anticorrosion effect.
Meanwhile, polyaniline is known as a material hard to handle because it is insoluble and difficult to be dispersed, despite its excellent function, it has many limits in its application. A recent technical development is capable of dispersing polyaniline into a matrix resin and permits its application in various fields and the development of products using it, but any application to the anticorrosion paints has not been reported.
Accordingly, the present invention is made to solve the problems of the prior art and the object of the invention is to provide anticorrosion paints for steel using polyaniline which has an excellent anticorrosion effect, long persistence of the anticorrosion effect, high durability and superior coating property controlling the anticorrosion effect, without using metals which cause environmental pollution as an anticorrosion pigment.
Another object of the present invention is to provide a method of simply preparing the anticorrosion paint.
To accomplish the above objects and other objects which can easily follow upon the above objects, the present invention provides a coated steel substrate comprising an anticorrosion paint system, wherein the paint system comprise a primer coat paint layer and a top coat paint layer: a primer coat paint layer including 3 to 49 weight percent (wt %) of the polyaniline, 40 to 86 wt % of the matrix resin, 1 to 47 wt % of the additives and 10 to 56 wt % of the mixed solvent; and a top coat paint layer for protecting for protecting the primer coat paint layer and improving the anticorrosion effect, the top coat paint layer including 40 to 89 wt % of matrix resin, 5 to 54 wt % of colored pigment, 1 to 50 wt % of additives and 5 to 54 wt % of mixed solvent.
Also, the anticorrosion paint of the present invention is characterized in that it uses no metal which has mainly been used in the prior arts as an anticorrosion pigment to solve the defects of the previous anticorrosion paint, and it uses polyaniline with an excellent anticorrosion function as the anticorrosion pigment to provide excellent anticorrosion effect on metal materials, particularly steel materials.
The present invention will hereinafter be described in further detail regarding the anticorrosion paint for steel using the polyaniline according to the preferred embodiments of the present invention.
Generally, the polyaniline is classified into a fully oxidized type, a partially oxidized type and a reduced type depending on an oxidation degree. Although the emeraldine base form of polyaniline (PANI-EB) is in an insulated state, it is transferred to the emeraldine salt form of polyaniline (PANI-ES) in a conductive state by doping the PANI-EB in protonic acid, such as hydrochloric acid. Electric conductivity is changed by doping level, the used organic solvent, and the kind of dopant or molecular weight. By improving doping level, the insulator-metal transition phenomenon occurs. The PANI-ES plays a role as a charge carrier by the formation of polaron that has a mobile defect in one-dimensional chain structure.
Emeraldine salt (electric conductivity: xcx9c5 S/cm) is synthesized in powder form by oxidatively polymerizing aniline monomer using oxidants, such as ammonium peroxydisulfate(APS; (NH4)S2O8) in protonic acid solution including 1M hydrochloric acid(HCl). The emeraldine salt is transferred to the insulating emeraldine base (electric conductivity: xcx9c10xe2x88x9210 S/cm) by deprotonation in basic solution, such as ammonium hydroxide(NH4OH).
Since both forms of polyaniline (base and salt thereof) were not dissolved in solvent, they have been difficult to be fabricated, but after it was reported in 1986 that N-methyl-2-pyrrollidinone could be used as solvent, the polyanilines became to be fabricated into film, fiber or elastomer. When the film or fiber was stretched four times and then doped with 1M HCl, it represented an electrical conductivity of 220 S/cm. The degree of cross-linking is controlled by varying the molecular weight of the polyaniline used for fabrication of the film, the use of solution or the evaporation rate of the solvent, and the resultant diverse films represent various results in crystallinity, electric conductivity after doping, an electric conductivity mechanism and electromagnetic interference shielding capability.
Recently, since the polyaniline doped with the functional acid like camphorsulfonic acid or dodecylbenzenesulfonic acid is known to have an increased solubility in nonpolar or mild polar solvents, such as m-crezol or chloroform, film or fiber can be fabricated directly from the polyaniline doped with the functional acid in the conductive state. This resultant film showed the phenomenon of an electrical conductivity of 400 S/cm at its maximum, depending on solvent. This phenomenon has been described by the notion of xe2x80x9ceffectively doped sitexe2x80x9d formed in the chain of polymer, depending on solvent. Unlike the previous doped polyaniline film, it was confirmed that this resultant film has a high negative dielectric constant and exhibits the metallic electrical conductivity because the electrical conductivity of this resultant film is little temperature-dependent.
The polyaniline used as an anticorrosion pigment in the present invention is both emeraldine salt of a reduced type and emeraldine base of an oxidized type.
The polyaniline used in the present invention is prepared as follows (in which aniline monomer is purified before use, and ammonium peroxydisulfate, H2SO4 and formic acid are used as such):
(1) A solution of aniline (40 Ml) in 80:20 (v/v %) of 1M H2SO4 and formic acid (800 Ml) in a vessel 1 is first cooled to 0xc2x0 C. and a solution of ammonium peroxydisulfate (23 g) as an oxidant in 1M H2SO4 (200 Ml) in a vessel 2 is cooled to 0xc2x0 C. After the solution containing the oxidant of the vessel 2 is added to the solution containing aniline of the vessel 1 over 2 min while stirring with a magnetic bar, the resultant mixture is reacted for approximately 90 min while stirring with a magnetic bar. After that, the reaction mixture is filtered through a filter paper.
(2) The resulting filtrate from process (1) is added without aniline at 0xc2x0 C. to a solution of ammonium peroxydisulfate (23 g) in 80:20 (v/v %) of 1M H2SO4 and formic acid and then the solution reaches 1L of total volume. The resultant mixture is reacted for approximately 90 min, and then the reaction mixture is filtered through a filter paper three times.
(3) The resultant filtered solid from processes 1 and 2 is added again to 1M HCl solution, stirred to make a suspension, and then further stirred by a magnetic bar for approximately 15 min, and filtered through a filter paper to obtain the reduced form of polyaniline.
After the filtrate is washed with 1M HCl until it is completely colorless, the protonated polyaniline is obtained.
Such a preparation of polyaniline according to the present invention is characterized in that the process of adding the only oxidant without additional aniline to the filtrate obtained after synthesis is repeated three to five times and nearly similar polyaniline in the physiochemical properties such as an electrical conductivity and thermal stability is obtained.
Therefore, the synthesis of the present invention provides much higher yield than that of the prior art.
And the reduced form of polyaniline obtained from the above synthesis may be dedoped with 0.1M NH4OH to produce the oxidized form of polyaniline.
The molecular structure of polyaniline of the present invention is as follows:
From the preparation of the present invention, the aniline monomer was synthesized to the polymerized polyaniline having 10,000 to 50,000 of molecular weight.
The content of polyaniline used in the present invention is preferably in a range of 3 to 49% by weight. When the content of polyaniline is less than 3% by weight, it results in the problems such as poor anticorrosion effect and a reduced persistence of anticorrosion effect. When the content of the polyaniline exceeds 49% by weight, the addition of polyaniline has little improvement so that it is not economical, and the film shows a tendency of being easily separated decrease of film durability.
First of all, the method of preparing a primer coat using polyaniline (either reduced form or oxidized form) comprises the step of mixing polyaniline, a matrix resin, various additives and mixed solvents at a predetermined ratio, and milling the mixture. The primer coat may further comprise an extender.
More particularly, 3 to 49% by weight (wt %) of polyaniline, 40 to 86 wt % of a matrix resin, 1 to 47 wt % of additives, and 10 to 56 wt % of mixed solvents are mixed, and the mixture is milled for 90 min using an attrition mill. If desired, an extender may be added to the mixture and the content of the extender is preferably in a range of 5 to 15 wt %. When the extender is added, the content of the matrix resin and the mixed solvents together should be decreased by the same amount as that of the extender.
The matrix resins are for example cellulose acetate propionate (100% of solid content), a thermoplastic polyurethane resin (50% of solid content), acrylic urethane (50% of solid content), epoxy ester (60% of solid content) or epoxy resin (100% of solid content), which can be used either alone or as a mixture of two or more.
The content of matrix resins is preferably in a range of 40 to 86 wt %. Where the resin content is less than 40 wt %, it is disadvantageous in that adhesion between the surface of metal materials and paint is decreased. Where the resin content exceeds 86 wt %, it is disadvantageous in that the content of polyaniline is relatively decreased and the anticorrosion effect is reduced.
As additives, a wetting dispersion agent, an anti-settling agent, a defoamer, an anti-cratering agent, an anti-sagging agent, a leveling agent, an anti-pinhole agent, or a plasticizer may be employed. It is preferred that a mixture of at least two kinds of the above additives are used according to the properties of the paint. The kind and content of the additives will be readily understood by those who skilled in the art.
The content of the additives should do not exceed total 47 wt %. Where the content exceeds 47 wt %, it is disadvantageous in that the adhesion between the surface of metal materials and the paint is greatly decreased.
As extenders, talc, calcium carbonate, barium sulfate or clay may be used.
As solvents, xylene, toluene, methyl isobutyl ketone, butyl acetate, ethyl acetate, cellosolve acetate, ethyl cellosolve, n-butanol, iso-butanol, isopropylalcohol, methyl ethyl ketone, cyclohexanone, methanol or diacetone alcohol may be used either alone or as a mixture of two or more thereof.
The top coat that is used to protect an anticorrosion paint for the primer coat and to improve an anticorrosion effect is prepared by adding 40 to 89 wt % of matrix resins, 5 to 54 wt % of colored pigments, 1 to 50 wt % of additives and 5 to 54 wt % of mixed solvents.
Epoxy resin or acrylic urethane resin may be employed as the resins, and inorganic or organic pigments, such as titanium oxide, iron oxide (reddish brown, yellow or black), phthalocyanine blue or phthalocyanine green, may be used after being mixed depending on a desired color, as the colored pigments. As the additives, a wetting dispersion agent, an anti-settling agent, a defoamer, an anti-cratering agent, an anti-sagging agent, a leveling agent, anti-decolorizing agent or an anti-pinhole agent may be employed.
As Solvents, xylene, toluene, methyl isobutyl ketone, butyl acetate, ethyl acetate, cellosolve acetate, ethyl cellosolve, n-butanol, isobutanol, isopropylalcohol, methyl ethyl ketone, cyclohexanone, methanol or diacetone alcohol may be used either alone or as a mixture of two or more thereof.
The present invention will hereinafter be described in further detail by examples and comparison examples. It should however be borne in mind that the present invention is not limited to or by the examples.

Anti-corrosion paint for steel with polyaniline


A method for forming a contact of a semiconductor device is described, in which a conductive layer pattern is electrically connected to a semiconductor substrate and an interlayer insulating film is formed on the semiconductor substrate including the conductive layer pattern. The interlayer insulating film is etched down to a top surface of the conductive layer pattern using a contact formation mask to form a contact hole. The conductive layer pattern is isotropically etched through the contact hole so as to extend the surface area of the exposed conductive layer pattern and the contact hole is filled with conductive material, forming a contact plug electrically connected to the conductive layer pattern. It is therefore possible to extend the contact area between the conductive layer pattern and a contact plug. As a result, the contact resistance is reduced.

As DRAM (dynamic random access memory) devices have become more finely structured, both the area of such devices and the diameter of contacts used on these devices have been reduced. Despite a reduction of both the area and the diameter in the horizontal direction, however, this fine structure does not effect the structural characteristics of a DRAM in the vertical direction. Accordingly, contacts must be both fine and long.
Referring to FIG. 1, a device isolation region (not shown) defining an active region and an inactive region is formed in a semiconductor substrate 10. A first conductive layer (not shown), a second conductive layer (not shown), and a gate mask 16 are formed over a semiconductor substrate 10 in the active region with a gate oxide layer (not shown) interposed between these layers and the substrate 10. The first and second conductive layers are then etched using the gate mask 16 as an etching mask to form a gate electrode of a double layer structure including first and second gate electrode portions 12 and 14.
After or before the formation of the insulating layer spacer 16, impurity ions are implanted to form a source/drain region (not shown) in the semiconductor substrate 10 outside of the area covered by the gate electrode 12 and 14. A first interlayer insulating film 20 is then formed over the semiconductor substrate 10 and the gate electrode 12 and 14.
The first insulating film 20 is penetrated by a first contact hole 21, and the resulting contact hole 21 is filled with a conductive material to form a contact pad 22 that is electrically connected to the source/drain region.
A second interlayer insulating film 24, including an embedded bit line 26, is then formed over the first interlayer insulating film 20. The second insulating film 24 is etched to form a second contact hole 28 that exposes a top surface of the contact pad 22. A silicon nitride layer spacer 30 is then formed on the sidewalls of the contact hole 28.
The second contact hole 28 is then filled with a conductive material to form a buried contact (BC) 32 that electrically connects a lower capacitor electrode to the contact pad 22. In order to make this electrical connection to the buried contact 32, a conductive layer (not shown) is formed over the second interlayer insulating film 24. The conductive layer is then patterned to form the lower capacitor electrode 34.
In the DRAM device of a capacitor over bit line (COB) structure, as described above, the buried contact 32 becomes fine and long. Furthermore, as shown in FIG. 1, the spacers 30 formed on the sidewalls of a contact hole may reduce the contact area between the contact pad 22 and the buried contact 32. As a result, the resistance between the contact pad 22 and the buried contact 32 increases, thereby slowing down the operation speed of the DRAM and potentially making an electrical open circuit, if the resistance is high enough.


A semiconductor device which includes: a semiconductor chip with plural pads; a tab connected with the semiconductor chip; bus bars which are located outside of the semiconductor chip and connected with the tab; a sealing body which resin-seals the semiconductor chip; plural leads arranged in a line around the semiconductor chip; plural first wires which connect pads of the semiconductor chip and the leads; and plural second wires which connect specific pads of the semiconductor chip and the bus bars. Since the sealing body has a continuous portion which continues from a side surface of the semiconductor chip to its back surface to a side surface of the tab, the degree of adhesion among the semiconductor chip, the tab and the sealing body is increased. This prevents peeling between the tab and the sealing body during a high-temperature process and thus improves the quality of the semiconductor device (QFN).

The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly to technology which is effective for a semiconductor device with exposed leads on the back surface of a sealing body.
A conventional semiconductor device consists of a semiconductor chip with multiple input/output pads, a chip mounting plate bonded to the semiconductor chip using an adhesive agent, inner leads with upward burrs at the most remote end from the chip mounting plate, and conductive wires for electrically connecting the input/output pads of the semiconductor chip with the inner leads. Here, the bottoms of the chip mounting plate and inner leads are exposed to the outside. (See Patent Literature 1.)
[Patent Literature 1] Japanese Unexamined Patent Publication No. 2001-77278 (FIG. 1)

Method of manufacturing semiconductor device


Biologically active oxidized variants of granulocyte-macrophage colony stimulating factor (GM-CSF) are provided in which one or more methionine residues are oxidized. Methods are also provided for making and characterizing such variants.

The control of blood cell formation is mediated by a group of glycoproteins called colony stimulating factors. One such protein is granulocyte-macrophage colony stimulating factor (GM-CSF), which stimulates progenitor cells to form granulocyte, macrophage and eosinophil colonies on semisolid medium [Lopez et al., J. Clin. Invest. 78: 1220 (1986); Metcalf, Blood 67: 257 (1986)]. GM-CSF can stimulate the initial cell divisions of erythroid progenitor cells without altering their ultimate ability to form mature red cells [Sieff et al., Science , 230: 1171 (1985)]. It also can stimulate colon), formation in the HL60 and KG-1 human myeloid leukemic cell lines [Tomonaga et al., Blood 67: 31 (1986)]and has a direct effect on neutrophil function [Lopez et al., J. Clin. Invest. 78: 1220 (1986)].
The cloning and sequencing of complementary DNAs encoding human [Lee et al., Proc. Natl. Acad. Sci. USA 82: 4360 (1985); Wong et al., Science 228: 810 (1985); Cantrell et al., Proc. Natl. Acad. Sci. USA 82: 6250 (1985)], gibbon [Wong et al., supra and murine [Gough et al., Nature 309: 763 (1984)]GM-CSF have been reported. Greenberg et al. [Current Microbiol. 17: 321 (1988)]have described the expression of biologically active, mature human GM-CSF in an E. Coli secretory expression system. The isolation of natural GM-CSF from cultured human [U.S. Pat. No. 4,438,032; Gasson et al., Science 230: 1171 (1985); Burgess et al., Blood 69: 43 (1987)], mouse [Burgess et al., Exp. Hematol. 9: 893 (1981); Sparrow et al., Proc. Natl. Acad. Sci. USA 82: 292 (1985)] and rat [Wu et al., Exp. Hematol. 12: 267 (1984)] cells has also been reported.
Mature human GM-CSF consists of about 127 amine acid residues, four of which are methionine residues. The mature forms of mouse and gibbon GM-CSF appear to contain only three methionine residues. GM-CSF from various species is also known to contain a number of cysteine residues, and the human protein contains four.
Methionine and cysteine are often important to the overall conformation and biological activity of a protein. The side chains of methionine residues are hydrophobic and tend to associate with other hydrophobic residues in the stable conformation of a protein. The sulfhydryl groups of cysteines are often joined in disulfide linkages (as cystine), which also serve to maintain conformation.
Under oxidizing conditions, the character of methionine and cysteine residues changes markedly. The sulfur in methionine is converted from a thio ether to a highly polar sulfoxide or sulfone. If a given methionine was associated with other hydrophobic residues, there is a likelihood that the hydrophilic oxidized form will no longer do so. Oxidation of cysteine residues can give rise to unnatural intra- and inter-chain disulfide bridges.
The possible overall effect of the oxidation of a protein can thus be a dramatic change in conformation (3-dimensional shape) which can result in a strong reduction or complete loss of biological activity. Whether a given protein will be thus altered by oxidation cannot presently be predicted with any reasonable degree of certainty.


A method of enhancing a server's ability to withstand a SYN flood type denial of service attack is presented. Modifications to the TCP/IP layer of a server reduce the amount of system resources that are allocated, and the amount of CPU overhead that is required to process a connection request until the TCP/IP three-way handshake is completed to verify the presence of a legitimate client. Specifically, the TCP/IP layer allocates a small TCP control block (TCB) of a size sufficient only to service the connect request upon receipt of the SYN packet. A full TCB is not allocated until the connection is completed. Further, the TCP/IP layer delays notification to the socket layer of the receipt of the SYN packet until after the connection is completed. Finally, the route information of the connection is not cached until after the connection is completed.

Despite early skepticism, businesses have now fully embraced the Internet as a vehicle critical to the success of their continued operations. The explosion of e-commerce and the emergence of business to business (B2B) technologies and industry utilization, as well as the proliferation of personal computers (PCs) have galvanized the business mindset and the consuming public to the use of the Internet as an everyday tool for commerce. The explosion of such use has pushed the limits of Internet technology faster and further than heretofore thought possible. Unfortunately, such explosion has also brought forth an unsavory element know as hackers that threatens to bring down, or at least hobble this new e-commerce business paradigm that is otherwise beginning to flourish.
One technique that these hackers have employed against Web servers is known as a SYN flood denial of service attack. This type of attack is based on the realization by the hackers that many corporate Web sites are getting millions of hits per day, and that many servers are not able to respond crisply under these heavy loads. Even with only the volume of legitimate connect requests from actual potential customers, many servers often slow down network connections, deny service for potential customers, and even cause network failures due to the sheer volume of business which potential customers are attempting to conduct on the Web server. Such performance slow downs and denial of service problems tend to increase customer dissatisfaction, reduce sales, and diminish the possibility for repeat customers. These problems translate directly into lost sales and lost business opportunities. Unfortunately, this disruptive and non-productive environment appears to be exactly what many hackers are seeking, and have devised the SYN flood denial of service attack to foster its existence.
On Feb. 7, 8, and 9, 2000, this very type of denial of service attack was used to block access to legitimate users of many popular Websites, including Yahoo, Buy.com, eBay, CNN.com, Amazon.com, ZDNet, E*Trade, and Datek. This type of attack was also blamed for the Feb. 18, 2000, shutdown of the Federal Bureau of Investigation's (FBI) Website for several hours. Warnings of such attacks had been issued by the National Institute of Standards and Technology, Carnegie Mellon's Computer Emergency Response Team Center, and the FBI. However, despite the warnings and all the preparations and precautions taken by Internet Service Providers (ISPs) against such attacks, including rate filters, these Websites were still taken down for several hours. The failure of these Websites to protect against such a simple attack has called into question the vulnerability of Internet companies.
Spurred by the February 7-9 attacks, the President of the United States called an emergency Web security summit on February 15 with experts, government officials (including the Attorney General, the National Security Adviser, the Commerce Secretary, and others), and high-tech business leaders to address the concerns felt by the federal government and private industry about such attacks. This problem is so serious that the Attorney General of the United States of America has charged federal law enforcement officials to combine their resources to combat this type of online terrorism, enlisting the FBI and the National Infrastructure Protection Center (NIPC) in the fight. Further, the President has sent a budget request of $2 Billion to Congress for government efforts to combat computer sabotage by cyberterrorists.
To understand these SYN flooding denial of service attacks, one must first understand the way the Internet, and the servers connected to the Internet, operate. Lying at the core of the explosion of the popularity and usage of the Internet is the Web server and browser communication protocol known as hypertext transfer protocol (HTTP). HTTP is the network protocol used to deliver virtually all files and other data, known collectively as resources, on the worldwide Web. These resources include HTML files, image files, query results, etc. This network protocol typically takes place through TCP/IP sockets. As with other network protocols, HTTP utilizes a client-server model. In this model, an HTTP client (such as a consumer) opens a connection and sends a request message to an HTTP server (e.g. a corporate Web server). Once the HTTP server has received the request from the client, it returns a response message, typically containing the resource that was requested by the client. For most typical browsing transactions on the Internet, the server then closes the connection after delivering the response. As such, HTTP is a stateless protocol, i.e. not maintaining any connection information between transactions.
The actual mechanism of an HTTP transaction, such as a Web browsing connection, is shown in FIG. 7, which illustrates the basic request/response message flow between a client and a server. As may be seen from this simplified figure, a client 500 establishes a TCP connection to a server 502 by transmitting a connect request 504 (TCP SYN) to the server 502. This SYN 504 is received at the TCP/IP layer 506 within the server 502. This TCP/IP layer 506 then creates a TCP control block (TCB) to service the connection, and notifies 508 the connect request to the socket layer 510. The socket layer 510 then indicates 512 to the TCP/IP layer 506 the acceptance of this connect request. At this point, the TCP/IP layer 506 caches route information about the connection and client, and transmits an acknowledgment (TCP SYN+Ack) 514 to the client 500 who then completes the connect request by acknowledging (TCP Ack) 516 the server's acknowledgment of its initial request. This three-way handshake establishes the TCP connection over which the client 500 then transmits the HTTP "Get file" request to the server.
In a SYN flood attack, the hacker takes advantage of the server's allocation of resources and desire to establish a connection to service a client, recognizing that a server will attempt several times to establish a connection with a client before giving up the connection attempt and freeing the resources allocated to the connection. The abuse of the TCP/IP connect attempt arises at the point where the server system 502 has sent an acknowledgment (SYN-ACK 514) back to the client 500, but has not yet received the ACK 516 message. This is known as a half-open connection. The server 502 typically has built in it system memory a data structure describing all pending connections. Since this data structure is of finite size, it can be made to overflow by intentionally creating too many half-open connections.
Creating half-open connections is easily accomplished by the hacker with IP spoofing. The attacking system sends SYN messages 504 to the victim server system 502 that these appear to be legitimate, but in fact reference a client system that is unable to respond to the SYN-ACK messages 514. This means that the final ACK message 516 will never be sent to the victim server system 502. The half-open connections data structure on the victim server system 502 will eventually fill, at which point the system 502 will be unable to accept any new incoming connections until the table is emptied out. Normally there is a timeout associated with a pending connection, so the half-open connections will eventually expire and the victim server system 502 will recover. However, the attacking system can simply continue sending IP-spoofed packets requesting new connections faster than the victim system can expire the pending connections.
The time-out may be quite long due to the server's desire to establish a connection with the client so that it may service its request. Often, a server 502 will retransmit the SYN-ACK 5 times, doubling the time-out value after each retransmission. The initial time-out value is three seconds. Therefore, the server 502 will retransmit the SYN-ACK at 3, 6, 12, 24, and 48 seconds after the first transmission. After the last transmission of the SYN-ACK, the server waits 96 seconds before giving up on the connection attempt and deallocating the resources that were allocated earlier for the connection. In this example, the server has tied up the allocated resources for a total of 189 seconds. In most cases, the victim of such an attack will have difficulty in accepting any new incoming network connections. In these cases, the attack does not affect existing incoming connections or the ability to originate outgoing network connections. However, in some cases, the system may exhaust memory, crash, or be rendered otherwise inoperative.

System and method for enhancing a server's ability to withstand a “SYN flood” denial of service attack


A semiconductor device and a method of producing the same, the device including a semiconductor chip; balls which function as external connecting terminals; a substrate which electrically connects the semiconductor chip and the balls; a mold resin which seals at least a part of the semiconductor chip; and a connecting portion sealing resin which seals the connecting portion between the substrate and the semiconductor chip. The semiconductor device is mounted onto a printed circuit board via the balls. The thermal expansion coefficient of the mold resin is matched with the thermal expansion coefficient of the printed circuit board. A side surface holding portion for the holding the side surfaces of the semiconductor chip is formed in the mold resin to restrict thermal deformation of the semiconductor chip.

1. Field of the Invention
The present invention generally relates to a semiconductor device and a method of producing the same and, more particularly, to a semiconductor device of a surface mount package type and a method of producing the same.
2. Description of the Related Art
Generally, a BGA (Ball Grid Array) type semiconductor device is well known as a semiconductor device of the surface mount package type. The BGA-type semiconductor device has ball-like protrusion electrodes (bumps) as external connecting terminals, and the protrusion electrodes are bonded to a printed circuit board so that the semiconductor device is mounted onto the printed circuit board.
In recent years, there has been an increasing demand for highly reliable electronic equipment onto which semiconductor devices are mounted, and, hence, high reliability is also expected when a semiconductor device is mounted onto a printed circuit board.
FIG. 1 shows a conventional semiconductor device of a surface mount package type. A BGA-type semiconductor device 1 comprises a semiconductor chip 2, a wiring board 3 (hereinafter referred to as "substrate 3"), protrusion electrodes 4 (hereinafter referred to as "balls 4"), and a mold resin 5. The substrate 3 comprises insulating resin tape 6 made of polyimide (hereinafter referred to as "PI tape") and a wiring layer 7. The semiconductor chip 2 is mounted on the upper surface of the substrate 3 with a bonding member 10.
Ball attachment holes 8 are formed in ball attachment positions in the PI tape 6 of the substrate 3. The wiring layer 7 is made of copper foil formed into a predetermined pattern. Metal wires 9 are bonded between the wiring layer 7 and the semiconductor chip 2, and are connected to the balls 4 through the ball attachment holes 8. In this manner, the semiconductor chip 2 is electrically connected to the balls 4 via the metal wires 9 and the wiring layer 7.
The balls 4 are bumps which function as external connecting terminals, and are formed by soldering. The balls 4 are bonded to the wiring layer 7 through the ball attachment holes 8 formed in the PI tape 6. The balls 4 are also disposed on the mounting surface of the substrate 3 (on the bottom surface in FIG. 1) in an area array so as to accommodate the high-density semiconductor chip 2 and the small semiconductor device 1.
The mold resin 5 is formed on the upper surface of the substrate 3, on which the semiconductor chip 2 is mounted, so as to protect the semiconductor chip 2, the wiring layer 7, and the metal wires 9.
The semiconductor device 1 is surface-mounted on a printed circuit board 11. More specifically, the balls 4 are positioned with electrodes 12 formed on the printed circuit board 11, and the semiconductor device 1 is then placed on the printed circuit board 11. The balls 4 are bonded to the electrode 12 by reflow soldering, so that the semiconductor device 1 is mounted on the printed circuit board 11.
The semiconductor chip 2 in the semiconductor device 1 generates heat when operated. The temperature of the semiconductor chip 2 rises during when operated, and drops when stopped. By the heat, the semiconductor device 1 thermally expands.
However, since the thermal expansion coefficients of the semiconductor device 1 and the printed circuit board 11 are different, a thermal expansion difference occurs between the semiconductor device 1 and the printed circuit board 11, thereby causing stress in the bonding position between the semiconductor device 1 and the printed circuit board 11. Such stress might results in removal of the balls 4 from the electrodes 12.
To solve this problem, a semiconductor device 20 shown in FIG. 2 has been developed. In FIG. 2, the same components as in the semiconductor device 1 shown in FIG. 1 are indicated by the same reference numerals.
The semiconductor device 20 is characterized by a buffer member 21 interposed between the semiconductor chip 2 and the substrate 3. The buffer member 21 is made of elastomer (a low elastic modulus material), and is elastically deformed. The substrate 3 is disposed on the bottom surface (the surface facing the printed circuit board 11) of the buffer member 21.
The semiconductor chip 2 has a face-down structure, and the semiconductor chip 2 and the substrate 3, between which the buffer member 21 is interposed, are electrically connected by the metal wires 9. A potting resin 22 formed by potting seals the semiconductor chip 2.
Transfer molding cannot be performed on the structure having the buffer member 21 that can be elastically deformed. For this reason, the potting resin 22 seals the semiconductor chip 2 and the metal wires 9.
The buffer member 21 interposed between the semiconductor chip 2 and the substrate 3 takes up a thermal expansion difference between the semiconductor device 20 and the printed circuit board 11. Thus, stress is prevented between the semiconductor chip 2 and the substrate 3, and the bonding reliability (packaging reliability) between the balls 4 and the electrodes 12 can be improved.
With the semiconductor device 20, however, there is a problem that the buffer member 21 interposed between the semiconductor chip 2 and the substrate 3 adds to the number of components and complicates the production procedures, resulting in high production costs.
Another problem is that the semiconductor device 20 becomes taller than the semiconductor device 1 by the height of the buffer member 21 between the semiconductor chip 2 and the substrate 3.
The semiconductor chip 2 attached to the buffer member 21 can be sealed only by the potting resin 22, and a fillet-like concave portion 23 is inevitably formed on the boundary of the potting resin 22 and the upper surface of the semiconductor chip 2. Because of the concave portion 23, the upper surface of the semiconductor device 20 formed by the semiconductor chip 2 and the potting resin 22 is not flat, resulting in another problem that desirable chucking cannot performed with the semiconductor device 20.
If the semiconductor device 20 is transported using a vacuum chuck, it is necessary to chuck the upper surface of the semiconductor device 20 having the balls 4 formed on the mounting surface (the bottom surface) of the substrate 3. Especially for the small chip size package shown in FIG. 2, it is necessary to vacuum chuck the entire upper surface of the semiconductor device 20 (i.e., the entire upper surface formed by the semiconductor chip 2 and the potting resin 22).
With the potting resin 22, however, the upper surface of the semiconductor device 20 is not flat due to the fillet-like concave portion 23 on the upper edge. Furthermore, the entire surface of the vacuum chuck needs to be in contact with the upper surface of the semiconductor device 20, but air entering through the concave portion 23 lowers the degree of vacuum and hinders secure chucking.

Surface mount type semiconductor device and method of producing the same having an interposing layer electrically connecting the semiconductor chip with protrusion electrodes


A computer disc drive includes a disc with circumferentially arranged tracks, a number of sectors on each track, with each sector including positional and data fields. The disc drive also includes a servo system with a magnetic head, arm, motor, and servo signal processor. One track of the disc drive includes a number of sectors, with each of the sectors including a positional field. A second track of the disc drive includes a number of sectors, with each of the sectors including a positional field. The positional fields of the second track are in a phase variant relationship, or staggered configuration, with the positional fields of the first track. Thus, the magnetic head reading from the first track or the second track is assured of producing a coherent signal with positional information that is sufficient for the servo system to process, despite interfering magnetic patterns between the two tracks. The resulting variably coherent signal with positional information allows the servo system to reposition the arm to a desired position.

Computer disc drives are known in the art. Such systems include a number of coaxially arranged discs. Each disc is coated with a thin film of magnetic storage media. Each disc further includes a number of concentric tracks. Each track is divided into a number of sectors; data is stored in the sectors on each track.
For each disc, there is a magnetic head assembly, supported by an arm, which is selectively positioned over tracks on the disc to access the data. The width of the magnetic head is approximately equal to the width of a track.
In addition to reading and writing a user's data on the disc, the head is utilized as a position transducer component in a servo mechanism. Head position information is embedded directly on the tracks of each disc at the beginning of each sector. As the disc is rotated, the head reads the position information and transmits this information to a track position detector for processing. The actual position of the magnetic head is compared with its desired position. The difference is processed to generate a signal which is fed to a DC motor which re-positions the head at a corrected position. This servo procedure is repeated until the actual position of the head equals the desired position.
This radial positioning of the head assembly is typically undertaken in two steps. First, the head assembly seeks a particular track on the disc. This is achieved by processing position information associated with each sector of each track. That is, previously embedded sector information is read and processed as the head moves across the tracks of the disc. This step results in a rough positioning of the assembly relative to a desired track. In order to read a particular sector located on the track, in the next step, the head assembly is precisely positioned with respect to the target track. This is achieved by reading "A" and "B" servo bursts from their position centered half way between the center lines of data tracks adjacent to and on either side of the target track. The "A" and "B" bursts are processed and the head position is adjusted such that the signal from the "A" burst equals that from the "B" burst. When the signals are equivalent, the read head is positioned on the track center line. This precise alignment is maintained until it is necessary to move to another track.
A problem associated with this technology is that the servo mechanism requires precise processing of all track position data. This is particularly necessary when the data is stored on discs in a high density configuration. However, as a result of vibrations, spindle bearing run-out and other factors, when writing track position information, the servo writer is not as accurate as necessary. Whole tracks of magnetic patterns may be misplaced slightly from their proper position both radially and circumferentially.
Radial misplacements may be controlled adequately with precision servowriter mechanics and position control systems. On the other hand, for high density magnetic patterns, circumferential mispositioning may result in adjacent tracks being written entirely out of phase with one another. Thus, as the head crosses between tracks, the two tracks may destructively interfere with one another, thereby resulting in a composite signal of undetectably small amplitude. In this case, position information is not gathered and the operation of the servo mechanism is seriously disrupted.
This problem is not readily solved. As track bit densities increase, achieving track-to-track coherence requires more exacting tolerances on mechanical parts. The requisite tolerances are difficult to obtain. Similarly, the problem is difficult to solve by adjusting variables such as non-repeatable bearing run-out, head skew angle, or timing jitter during servo pattern writing.

Disc drive head positioning servo system with coherent adjacent track magnetic patterns