A safety device for a hydraulic elevator includes an open-door running prevention unit and a pressure sensor. The open-door running prevention unit includes a memory configured to sequentially store values of the pressure sensor during a period in which the hydraulic elevator is in the open-door state as time-series data. When it is determined that the car speed, detected when the hydraulic elevator is in the open-door state, is equal to or larger than a preset first threshold value, the open-door running prevention unit calculates a differential value between a maximum value and a minimum value of the time-series data stored in the memory in a period of a preset determination time. When the differential value is out of a preset allowable range, the open-door running prevention unit determines that the open-door running abnormality is present, and executes the car braking processing.

As related-art open-door running prevention units for a hydraulic elevator, there have been proposed a braking method using an emergency stop device (see, for example, Patent Literature 1), a method using a dual check valve (see, for example, Patent Literature 2), and the like.
Each of the open-door running prevention units monitors a position of a car or a speed of the car in an open-door state to determine an abnormal state and performs a braking operation for the car.

Hydraulic elevator safety device, and method for detecting open-door travel abnormality in hydraulic elevator


An absorbent pad for meat and poultry products and the like and a method for constructing same is disclosed. The absorbent pad includes upper and lower plastic film layers, at least one of which is perforated, and an intermediate absorbent layer disposed between the layers. The intermediate absorbent layer includes a series of juxtaposed and overlapping absorbent material fibers with superabsorbent granules dispersed throughout the absorbent layer and supported by the absorbent material fibers within interstices thereof. The superabsorbent granules are capable of absorbing and suspending liquids therein while being retained and supported by the absorbent material fibers even when the absorbent material fibers have liquid therein. The upper and lower film layers are attached to one another at least partially along opposite marginal edge portions thereof to retain the absorbent layer between the upper and lower layers. The superabsorbent granular particles are homogeneously dispersed throughout the absorbent layer and supported in generally spaced relationship within the interstices of the absorbent material fibers, to enable suspension and retention of liquid by said superabsorbent granules and absorbent material fibers.

The present invention relates to an absorbent pad for meat and poultry products and the like, and to the method for constructing such absorbent pads. More particularly, the present invention relates to a new and improved absorbent pad incorporating superabsorbent granules therein, and to a method for constructing the same.
Meat and poultry food products are typically sold in a supporting tray that is overwrapped by a transparent plastic film or in transparent plastic bags, enabling viewing and inspection of the food products. The public has become accustomed to purchasing meat and poultry food products contained within such packages, not only because the products can be easily viewed and inspected, but also because consumers believe that the food products contained within such packages are maintained in a sterile environment. While it is true that supporting trays with transparent plastic overwrap and transparent plastic bags do, in fact, protect the food products from external contamination, consumers are not always aware of the potential for internal contamination, as the result of juices or liquids exuded from such food products. It has been found that juices or liquids exuded from such food products can support the rapid growth of bacteria which migrate back into and around the food products, resulting in spoilage or deterioration of food products. Furthermore, such exuded liquids or juices create an undesirable visual impression to a consumer, giving the consumer the impression that the food products are unappealing.
As a result, substantial developments have been made in an effort to overcome such problems. In general, these developments have centered around the use of an absorbent pad which is received in a supporting tray or bag and underlies food products in the supporting tray or bag. However, the problem is not so easily solved by providing an absorbent pad alone, because commonly used absorbent pads do not necessarily absorb all of such liquids or juices, and further, the meat or poultry product still come into contact with the juices or liquids absorbed by the absorbent pad. As a result, some absorbent pads have been developed with an imperforate plastic film or non-absorbtive barrier above the absorbent pad allowing side and bottom wicking of the exuded liquids and juices, while seeking to prevent reverse migration of the liquids or juices back into contact with the food products. An example of this is shown in U.S. Pat. No. 3,026,209. Some more recent developments have included the use of an absorbent pad sealed within upper and lower plastic films, and with one of the upper or lower films being perforated for top and/or bottom wicking of the exuded liquids or juices by the absorbent pad within the sealed upper and lower film layers. Examples of circumferential and peripherally sealed upper and lower plastic films containing an absorbent pad therein are shown by U.S. Pat. Nos. 4,275,811; 4,321,997; 4,382,507 and 4,410,578. In general, these patents teach that perforating only one film layer, referably the bottom film layer only, permits bottom wicking and retention of the exuded liquids or juices within the circumferentially sealed upper and lower film layers, without any reverse migration of the liquids or juices back into the food products.
While the aforementioned designs have worked quite well for their intended purposes, they have not solved all of the problems associated with exuded liquids or juices from meat and poultry products. Thus, where the bottom plastic film is perforated to allow for bottom wicking only, some liquids or juices remained trapped between the imperforate upper film layer and the food product, creating the potential for spoilage or discoloration. Even where both the upper and lower plastic film layers have been perforated to allow for both top and bottom wicking, the absorbent layer has not been sufficiently absorbent to retain the liquids or juices therein. Some of the prior art designs have even suggested various additives to the absorbent pad to increase its absorbency; however, in fact, none of the proposed additives have functioned well enough to absorb and retain the exuded liquids or juices within the absorbent pad. Where the absorbent pad has reached its maximum potential absorbency, no more liquids or juices can be absorbed, and this results in excess juices remaining outside of the absorbent pad for contact with the meat products and/or viewing by the consumer.
It has been observed that the absorbent pad, according to the U.S. Pat. Nos. 4,275,811, 4,321,997, 4,382,507 and 4,410,578, cannot sufficiently absorb and retain the juices from the meat products in certain applications. For example, if the absorbent pad is exposed to pressure, the juice will be squeezed out from the pad and onto the product. In U.S. Pat. No. 4,321,997, the absorbent pad is provided with a spacing means for preventing the squeezing out of the juices, recognizing that such problem exists.
According to the present invention, it has been observed that the inclusion of a superabsorbent material in the absorbent pad improves the retention properties of the absorbent pad so that it does not give off the absorbed liquid even when exposed to a pressure. Due to this property, it is now possible to enclose the absorbent pad within plastic sheets wherein the upper sheet is perforated. Thus, the risk that the juice is accumulated between the meat product and the upper sheet is avoided.
However, it is very important that the superabsorbent particles are evenly spaced within the absorbent pad and retained in place. According to the present invention, this object is achieved by including the superabsorbent particles in a network formed between cellulosic fibers and thermoplastic fibers (or other similar fibers), which are bonded in a thermobonding process. The superabsorbent particles are generally homogeneously dispersed or evenly spaced in the material and held in place by the interacting thermoplastic and cellulosic fibers. Thus, the superabsorbent particles, when absorbing liquid, are prevented from moving within the material. It is believed that this property is sufficient for preventing reverse migration of the juices back to the meat product, even when the upper sheet is perforated. In applications where higher demands are placed on the absorbent pad, it may be constructed with an imperforate upper sheet, but the sides thereof may still be unsealed so that the juices are absorbed through said sides.


A mechanism for providing error protection for data that is to be stored in a data storage system in which data are stored in data sectors in a data storage area and redundant information that provides error protection for the data are stored in redundant sectors in a redundant storage area. New data that is written to a designated one of the data sectors, and that is not error protected by the redundant information, is received, and error correction information for the new data is selectively stored in an additional storage area to provide error protection for the new data instead of revising the redundant information to provide such error protection.

The invention relates generally to data storage systems which use error correction codes to protect stored data from loss.
Error correction codes (ECC""s) are often employed in data storage systems to detect and correct data corrupted as a result of a media defect. Before a string of data symbols is recorded, it is encoded to generate redundancy symbols. The redundancy symbols are appended to the data symbols to form code words. When the code words are retrieved from data storage devices, the code words are decoded to detect and, if possible, correct any errors in the data. This decoding is accomplished through manipulation of the redundancy symbols.
Data may be encoded using an (n,k) D distance Reed-Solomon code to protect data stored on k data sectors of k data storage devices using nxe2x88x92k (or xe2x80x9crxe2x80x9d) redundant sectors of r redundant drives. When new data words are received for storage in designated sectors of the data storage devices, the redundancy information stored in corresponding sectors of the redundant drives is updated in order to provide error protection to the new data words. That is, when the new data words are stored in a designated data sector on a particular data storage device, such as a disk drive, the data words stored in the same sector location on each of the kxe2x88x921 other data drives are retrieved. An encoder encodes, using a Reed-Solomon code, the corresponding symbols from each of the kxe2x88x921 retrieved data words and the new data, and generates for each set of k symbols r redundancy symbols. The encoder thus encodes the first symbols from each of these words and generates a first set of r redundancy symbols, and next, encodes the second symbols from each of these words and generates a second set of r redundancy symbols, and so forth. Each set of r redundancy symbols and the associated k encoded symbols together form a Reed Solomon code word. This level of encoding is referred to as sector coding. The various sets of r redundancy symbols are written to the r redundant sectors, by writing one redundancy symbol from each set, that is, one symbol from each code, on each redundant sector.
If an error occurs in a sector or the drive on which the sector resides fails, the lost or erroneous data stored thereon can be regenerated using the associated Reed-Solomon code words. The data and redundancy symbols which form the associated code words are retrieved from the other sectors or drives. A decoder then manipulates the code words, using conventional error correcting techniques, to produce the otherwise lost symbols. A (n,k) Reed Solomon code of distance D can regenerate symbols even if errors or failures occur in up to Dxe2x88x921 sectors or drives simultaneously.
Although the above-described redundancy technique is quite robust, it requires extensive, time-consuming xe2x80x9cread-after-writexe2x80x9d operations. That is, each write operation requires that corresponding symbols from each of the data sectors be retrieved so that the retrieved symbols and the symbols to be recorded can be encoded to generate new redundancy symbols.
Another prior approach, described in U.S. Pat. No. 5,265,104, in the name of Lih-Jyh Weng, reduces the number of read-after-write operations by allowing a data storage system to perform up to [(nxe2x88x92k)/2]xe2x88x921 write operations before it retrieves and encodes the corresponding data code word symbols, along with the new data to be recorded, to generate new redundancy symbols. The protection of the re-written data is maintained by recording a copy of that data over redundant symbols on a redundant sector. Consequently, each such write operation introduces two erasures (i.e., errors with known locations) to the code. While this coding scheme requires fewer retrieval and encoding steps, it loses some error correction capacity for each write operation performed without the retrieval and encoding steps. That is, the effective distance of the code is reduced by two during each write operation which writes new data to both a data sector and a redundant sector.
This invention features an efficient way of providing error protection for data that is to be stored in a data storage system of the kind in which data are stored in data sectors in a data storage area and redundant information that provides error protection for the data are stored in corresponding redundant sectors in a redundant storage area.
In one general aspect of the invention, new data that is written to a designated one of the data sectors, and that is not error protected by the redundant information, is received, and error correction information for the new data is selectively stored in an additional storage area to provide error protection for the new data instead of revising the redundant information to provide such error protection.
Embodiments of the invention may include one or more of the following features.
The selective storing of the error correction information may include determining if the error protection provided by the redundant information is sufficient to enable error correction of data in other data sectors if the redundancy information is not revised. Such determination may include determining if the additional storage area has enough capacity to store the error correction information. If it is determined that the additional storage area does not have enough capacity to store the error correction information, then the redundant information is revised. The redundant information is revised in a sector encoding operation.
The additional storage area may include a plurality of additional sectors. Determining if the additional storage area has enough capacity may include the following: determining if the designated data sector has been written since a previous sector encoding; and if the designated data sector has not been written since the previous sector encoding, determining how many other ones of the data sectors have been written since the previous sector encoding.
The selective storing may further include storing the error correction information on an available sector in the additional storage area if the number of other ones of the data sectors written since the previous sector encoding is less than the number of sectors in the additional storage area. The previous sector encoding corresponds to the last sector encoding operation in which the redundant information was generated from the data in the data sectors.
The selective storing may further include revising the redundancy information if the number of other ones of the data sectors written since the previous sector encoding is not less than the number of sectors in the additional storage area. The revising of the redundancy information may include performing a sector encoding to regenerate the redundant information in the redundant sectors by encoding the data in the data sectors and the new data stored in the additional storage area.
The error correction information stored in the additional storage area may include error correction code (ECC) associated with the new data. That error correction information may further include a copy of the new data.
Alternatively, a first portion of error correction code associated with the new data may be stored in the designated data sector and the error correction information may include a remaining second portion of error correction code associated with the new data. If the data sectors each store a Reed Solomon code word of k data symbols and r ECC symbols, the r ECC symbols being generated by symbol encoding the data, then the length of the first portion of the error correction code associated with the new data may be a first number of ECC symbols and the length of the remaining second portion of error correction code associated with the new data may be a second number of ECC symbols equal to r minus the first number of ECC symbols.
The redundant sectors can have redundant symbols and the corresponding data symbols in the data sectors and associated redundant symbols in the redundant sectors may form Reed Solomon code words of k data symbols and r redundant symbols.
The number of additional sectors in the plurality of additional sectors in the additional storage area may be selected as rxe2x88x922.
The symbol size used by the sector encoding and the symbol encoding may be different.
The coding mechanism of the invention offers several advantages. It increases the overall reliability of disk sectors using sector encoding while reducing the frequency of read-after-write operations required by sector coding. Because the use of rxe2x80x2 (i.e., rxe2x88x922) additional sectors in the additional storage area reduces the number of erasures per write operation to one, the choice of rxe2x80x2 reduces the frequency of read-after-write operations required by a sector encoding operation to at least half of that of prior techniques that overwrite redundant sectors with data. That is, rxe2x80x2 writes of new data may be performed without revising the redundant sectors if error correction information is written to rxe2x80x2 sectors in the additional storage area. Additionally, because sector encoding is used, an ECC within a sector can be selected to be weaker than it could be without sector coding. Therefore, the ECC complexity within a sector is reduced.

Sector-coding technique for reduced read-after-write operations


A device for fixing an object to a support comprises, in a plate forming part of the object, at least one hole for a fixing to pass through. A gasket is applied to the plate at the location of the hole, and a bearing washer is disposed between the gasket and a head of the fixing. An immobilizing device associated with the bearing washer opposes movement of the bearing washer parallel to the plate and to allow movement of the bearing washer perpendicular to the plate. A confinement device associated with the gasket prevents the gasket escaping from the space between the bearing washer and the plate.

1. Field of the Invention
The present invention is generally concerned with fixing any kind of object to any kind of support.
It is more particularly, but not necessarily exclusively, directed to the case where a box adapted to accommodate any kind of equipment, such as electrical equipment, for example, is to be attached to any kind of wall.
The present invention is even more particularly directed to the case where, in order to be attached to any kind of support, the object concerned, whether it is a box or any other kind of object, is equipped with at least one fixing device comprising (in the part adapted to be applied to the support to which it is to be attached, described hereinafter as constituting a plate, in practise the back of the box in the case of a box) at least one hole adapted to have passed through it any kind of fixing means, such as a screw, for example, and which may be either circular or in the form of a slot where it is necessary to provide for levelling when fitting.
The present invention is still more particularly directed to the case where the corresponding fixing must be fluid-tight to avoid possible ingress of moisture through the hole(s) employed.
2. Description of the Prior Art
To this end it has been proposed in some boxes to provide each of the holes at the bottom of a well extending the full height of the box and which, at the open side of the box, is closed off by the gasket usually provided between the box and the lid which closes it.
However, the provision of a well of this kind in a box of this kind inevitably reduces the space available inside the box, to the detriment of its capacity for accommodating equipment, and this disadvantage is all the worse if, as mentioned above, the holes in question are in the form of slots.
In other boxes the necessary seal is achieved by associating with each of the holes employed a gasket which is in contact with the corresponding plate at the hole and a bearing washer inserted between the gasket and the head of the corresponding fixing means.
This arrangement has the disadvantage of entailing the manipulation of additional parts at installation time, in this instance the gasket and the bearing washer. Because they are relatively small, they can easily be dropped (and in practise therefore lost), the corresponding manipulation being even more difficult in the case of boxes given that these operations must be carried out inside the box.
A general object of the present invention is an arrangement which can avoid these problems.

Device for fixing an object to a support, and object incorporating at least one such fixing device


A liquid crystal display device includes a first substrate having a reflective region and a transmissive region, a second substrate corresponding to the first substrate, and a liquid crystal structure located between the first substrate and the second substrate, the liquid crystal structure including a first liquid crystal layer located in the reflective region and a second liquid crystal layer located in the transmissive region, wherein the first liquid crystal layer is configured to control movement of the second liquid crystal layer.

1. Field
Example embodiments of the present invention relate to liquid crystal display devices and methods of manufacturing liquid crystal display devices.
2. Description of Related Art
A liquid crystal display (LCD) device generally includes two transparent substrates and a liquid crystal layer located between the substrates. The liquid crystal display device displays an image by controlling transmittance of light according to orientation of liquid crystal molecules in the liquid crystal layer by varying an electric field generated between the substrates. The liquid crystal molecules in the liquid crystal layer may be arranged initially in a direction substantially perpendicular or substantially parallel to the substrate. Transparent electrodes are located on the substrates, respectively. When electric fields are generated in related pixels by applying voltages to the electrodes, the orientation of the liquid crystal molecules may vary to display the image. The liquid crystal molecules may be restored to an initial orientation state when the electric fields are not generated in the pixels.
The conventional transflective liquid crystal display device has a reflective region and a transmissive region through which light may pass. A reflection plate may be located in the reflective region. A liquid crystal layer may be continuously located in the reflective and the transmissive regions without dividing the liquid crystal layer in accordance with domains of pixels in the conventional transflective liquid crystal display device. As for the conventional transflective liquid crystal display device, pressure (e.g., predetermined pressure) may be applied to the liquid crystal device when a user touches a substrate of the liquid crystal display device to operate the liquid crystal display device. Thus, liquid crystal molecules in the liquid crystal layer may be undesirably orientated to cause strains or spots along portions of the substrate where the pressure is applied even though en electric field may not occur in a pixel of the liquid crystal display device. Additionally, the liquid crystal molecules might not be rapidly restored into an initial orientation state, thereby causing bruising of the liquid crystal molecules. Furthermore, adjacent portions of the liquid crystal layer may be continuously slopped by stress generated along the pressed portions of the substrate to thereby cause pooling of the liquid crystal molecules.

Liquid crystal display devices and methods of manufacturing liquid crystal display devices


A taper sleeve for a conveyor roller used in a curved conveyor section has a taper wall with internal radial ribs which mate with the surface of a cylindrical roller core. The inner edges of the ribs preferably have an interference fit with the core surface.

A curved section of a roller conveyor uses tapered rollers to move articles through the curve. It is known to fit a tapered sleeve over a cylindrical core, see Stumpf U.S. Pat. No. 3,934,951. Known sleeves, however, have a relatively thick wall in order to support articles carried by the conveyor without deformation or damage. This adds to the cost and weight of the sleeve.


A method for inspecting an object using a light measurement system that includes a light source and an imaging sensor. The method includes emitting light from the light source, dispersing light emitted from the light source into one of a diffraction pattern and an interference pattern, and imaging the patterned light onto the object using a lens.

This application relates generally to inspecting objects, and more specifically to methods and apparatus for inspecting objects using a light measurement system.
Objects are sometimes inspected, for example, to determine a size and/or shape of all or a portion of the object and/or to detect defects in the object. For example, some gas turbine engine components, such as turbine or compressor blades, are inspected to detect fatigue cracks that may be caused by vibratory, mechanical, and/or thermal stresses induced to the engine. Moreover, and for example, some gas turbine engine blades are inspected for deformations such as platform orientation, contour cross-section, bow and twist along a stacking axis, thickness, and/or chord length at given cross-sections. Over time, continued operation of the object with one or more defects may reduce performance of the object and/or lead to object failures, for example, as cracks propagate through the object. Accordingly, detecting defects of the object as early as possible may facilitate increasing the performance of the object and/or reducing object failures.
To facilitate inspecting objects, at least some objects are inspected using a light measurement system that projects a structured light pattern onto a surface of the object. The light measurement system images the structured light pattern reflected from the surface of the object and then analyzes the deformation of the reflected light pattern to calculate surface features of the object. However, at least some known light measurement systems are unable to adjust distribution of light over different areas of the illuminated surface of the object, possibly causing some areas of the illuminated surface to be too dark or too light to inspect. Some known light measurement systems utilize liquid crystal display (LCD), liquid crystal on silicon (LCOS), or digital micromirror device (DMD) devices as light sources that can adjust distribution of light over different areas of the illuminated object surface. However, at least some known LCD, LCOS, and DMD devices may have lower resolution than is desired for the light source. Moreover, at least some known LCD, LCOS, and DMD devices may not be capable of accurately constructing a smooth pattern of light, for example a sine wave, but rather may create a binary approximation. Film-type attenuators have also been used to control distribution of light over different areas of the illuminated surface of the object, for example to darken areas of the illuminated surface that may be too light to measure. However, at least some known attenuators may need to be changed when a different object is inspected and/or when the object, a light source, and/or an imaging sensor is re-orientated.

Methods and apparatus for inspecting an object


An optical apparatus that provides extraordinary light transmission through a sub-wavelength-sized light transmitting region of the apparatus includes a core region of dielectric material having a complex dielectric constant, ∈1, surrounded by a metallic cladding material having a complex dielectric constant, ∈2, wherein the core region has a maximum dimension, 2a, further wherein 2a is less than λ, where λ is the free-space wavelength of light incident on an input side of the apparatus, and further wherein |∈1| is greater than 0.5|∈2|, ∈1 has a positive real part, and ∈2 has a negative real part, whereby the incident light will be transmitted by and exit the apparatus from an output side with extraordinary transmission.

1. Field of the Invention
Embodiments of the present invention relate generally to the field of optics; more particularly to optical apparatus, methods and applications that provide and utilize the phenomena of extraordinary transmission of light through a sub-wavelength-sized aperture and, most particularly to the extraordinary transmission of light through a dielectric-filled aperture(s) in a real metal film.
2. Technical Background
Ebbesen et al. reported the discovery of extraordinary transmission through sub-wavelength aperture arrays (T. W. Ebbesen, H. J. Lezec, H. F. Ghaemi, T. Thio, P. A. Wolff, Nature 391 (1998) 667). Leven et al. developed zero-mode waveguides of diameters ˜ 1/10 of the illumination wavelength in order to measure single molecule chemical reactions in a nanoscopically restrained optical volume (M. J. Levene, J. Korlach, S. W. Turner, M. Foquet, H. G. Craighead, W. W. Webb, Science 299 (2003) 682). The proper operation of these nano-optical devices in recent single molecule spectroscopy experiments is crucially dependent on the confinement of light at the entrance of waveguide. The study of transmission through sub-wavelength apertures is particularly interesting for its potential applications in near-field scanning optical microscopy, high-resolution optical lithography and high-density optical data storage. In addition to aperture arrays, it has also been demonstrated that transmission through an isolated aperture is enhanced if the aperture is surrounded by certain periodic structures at its entrance surface (T. Thio, K. M. Pellerin, R. A. Linke, H. J. Lezec, T. W. Ebbesen, Opt. Lett. 26 (2001) 1972), and beaming of the transmitted light can occur if the exit surface is also textured (H. J. Lezec, A. Degiron, E. Devaux, R. A. Linke, L. Martin-Moreno, F. J. Garcia-Vidal, T. W. Ebbesen, Science 297 (2002) 820).
Transmission through a single cylindrical aperture and apertures of other shapes (e.g, C-shaped; H-shaped, others) has been investigated extensively in recent years in order to gain understanding of the mechanisms behind enhanced transmission and make use of this phenomenon in applications such as near-field scanning optical microscopy. While enhanced transmission can be achieved in some of the reported scanning probe designs with novel aperture shapes, the large overall probe sizes used in these designs make them undesirable, particularly for imaging delicate samples.
It has also been reported that transmission can be enhanced if a hole is filled with a dielectric material due to the increase of the cutoff wavelength. However, for wavelengths above the cutoff, transmission is still very low because no propagating modes are allowed inside the aperture.
The inventors have recognized the many benefits and advantages realizable by an optical apparatus that can provide enhanced (extraordinary) transmission through a sub-wavelength aperture, which overcomes the shortcomings known in the art for such apparatus and applications.

Extraordinary light transmission apparatus and method


A cleaning apparatus and a method of using the cleaning apparatus are provided. The method includes first moving a pencil pad into contact with a top surface of a wafer, wherein the pencil pad is connected to a pivot arm and second moving the pivot arm in a sweeping motion from a first zone to a second zone, the first zone being closer to a center of the top surface of the wafer than the second zone, wherein the sweeping motion is controlled by a controller, the pivot arm moves at a first speed in the first zone and the pivot arm moves at a second speed in the second zone, wherein the first speed is different from the second speed.

In the manufacturing process of semiconductor devices, an important step is smoothing a surface of a device after it has been made. For example, the formation of various features or layers in a device may cause uneven topography, and this uneven topography may interfere with subsequent manufacturing processes, such as the photolithographic process. It is desirable to planarize the surface of the device, using known methods such as chemical mechanical polish (CMP), after various features or layers have been formed.
During a CMP process, a wafer is placed on a carrier. The carrier and the wafer are then rotated as downward pressure is applied to the wafer against a polishing pad. A chemical solution, referred to as a chemical slurry, is deposited onto the surface of the polishing pad and under the wafer to aid in the planarizing. Thus, the surface of the wafer may be planarized using a combination of mechanical (the grinding) and chemical (the slurry) forces.
After the CMP process has been applied to a wafer, some residues such as carbon or adhesive films and particles may stay on the top surface of the wafer. These films and particles may cause surface roughness leading to defects in subsequent fabrication processes, such as a defect in the photolithography process due to the uneven surface of the wafer.
In order to remove the residues from the wafer, post-CMP cleaning processes may be applied to the wafer. The post-CMP cleaning processes may include a brush cleaning process, a pencil cleaning process and a drying process. During the brush cleaning operation, a brush is brought into contact with the top surface of the wafer. During a relative movement between the brush and the wafer, the contaminants are removed from the wafer surface.
The pencil cleaning process is applied to the wafer after the brush cleaning process. During the pencil cleaning process, a pencil pad is brought into contact with the surface of the wafer. During a relative movement between the pencil pad and the wafer, the remaining contaminants are removed from the wafer surface.
During the brush and pencil cleaning processes, various cleaning liquids may be applied to the wafer and remain on the top surface of the wafer. The remaining liquids may be removed by a spin drying process.

Taiwan Semiconductor Manufacturing Co., Ltd.


In the case where an uneven structure is formed on the surface of cylindrical electrophotographic photosensitive members, for the purpose of reducing the variation of the uneven structure between the individual cylindrical electrophotographic photosensitive members even when a large number of cylindrical electrophotographic photosensitive members are continuously processed, an insert is inserted into the interior of a cylindrical electrophotographic photosensitive member including a cylindrical substrate and a surface layer, the surface uneven structure of a molding member is transferred to and formed on the surface of the surface layer of the photosensitive member. The insert includes an abutting part having an outer peripheral surface capable of abutting on the inner peripheral surface of the substrate, a connecting part positioned inside of the abutting part in the radical direction and a shaft part positioned inside of the connecting part in the radical direction.

As electrophotographic photosensitive members, general are cylindrical electrophotographic photosensitive members (hereinafter, also simply referred to as "electrophotographic photosensitive members") each including a photosensitive layer formed on a cylindrical substrate. Among electrophotographic photosensitive members, organic electrophotographic photosensitive members including photosensitive layers (organic photosensitive layers) using organic materials as photoconductive materials (charge generating materials and charge transporting materials) have come into wide use. As organic electrophotographic photosensitive members, because of the advantages involving high sensitivity and versatility of material design, predominantly used are electrophotographic photosensitive members each having a laminated photosensitive layer formed by laminating a charge generating layer including a charge generating material and a charge transporting layer including a charge transporting material.
In the image forming process, electrophotographic photosensitive members are used in the repeated cycles of the processes of charging, exposing, developing, transferring and cleaning (and charge removing). In particular, the cleaning process for removing the residual toner staying on the surface of the electrophotographic photosensitive member after the transfer process is an important process for the purpose of obtaining clear images. As the cleaning method, common are the methods in each of which a rubber cleaning blade is pressed against the electrophotographic photosensitive member and thus the residual toner is scraped.
However, cleaning blades exhibiting excellent cleaning capability are large in frictional force with the surface of the electrophotographic photosensitive member, and hence tends to cause problems such as the driving torque increase, the slipping away of the toner due to the micro-vibration of the cleaning blade and the inversion of the cleaning blade. The effects of the size reduction and higher performances of toner particles according to a recent trend toward higher image quality on the cleaning performances are also dealt with.
Among the methods for solving the aforementioned problems, there is a method in which the surface of the electrophotographic photosensitive member is appropriately roughened. This method is effective in reducing the contact area between the surface of the electrophotographic photosensitive member and the cleaning blade and in reducing the frictional force.
Various methods are known for such surface roughening of the surface of the electrophotographic photosensitive member; however, in particular, for the purpose of effectively reducing the frictional force, it is necessary to finely control the surface shape and condition of the electrophotographic photosensitive member. As such a method, PTL 1 discloses a technique for compression molding processing by bringing a touch roll or a molding member (a mold) having an uneven structure on the surface thereof into contact with the surface of the electrophotographic photosensitive member. PTL 1 describes an example in which a SUS 304 touch roll having a prismatic and wavy structure is brought into contact with an electrophotographic photosensitive member by applying a force of 2×10−4 N, and thus, for example, a wavy structure having a pitch of 5 μm and an average depth of 5 μm is formed on the surface of the electrophotographic photosensitive member. PTL 1 also describes an example in which by using a molding member having a well-type structure in which wells having an average one side length of 100 nm and an average depth of 100 nm are formed with an inter-pitch distance of 100 nm, the surface of the electrophotographic photosensitive member was compressed for 2 minutes with a force of 0.8 N, and consequently, there has been formed, on the surface of the electrophotographic photosensitive member, a well-type structure in which wells having an average one side length of 70 nm and a depth of 30 nm are formed with an inter-pitch distance of 120 nm. It has also been disclosed that by heating the electrophotographic photosensitive member and the molding member during processing, the molding accuracy is improved, and the processing pressure is set at 1 N or less for the purpose of maintaining the circularity of the electrophotographic photosensitive member.
The compression molding processing technique disclosed in PTL 1 is an application of a heretofore known technique, to electrophotographic photosensitive members, such as an emboss processing technique, which is an uneven structure processing method for resin surface and others, or a nanoimprint technique which has recently been studied actively as a microprocessing technique.
In general, conventional techniques for performing uneven structure formation processing on the surface of resin films or resin moldings are performed according to the following steps as described in PTL 2:
(1) a resin to be processed is heated to a temperature equal to or higher than the glass transition temperature of the resin (a step of softening the resin so as to easily undergo thermal deformation);
(2) a molding member (a mold) is heated to a temperature equal to or higher than the glass transition temperature of the resin and brought into pressure contact with the resin (a step of penetrating the resin into the fine structures of the molding member);(3) after a predetermined elapsed time, the resin and the molding member are cooled down to a temperature equal to or lower than the glass transition temperature (a step of fixing the fine structure);(4) the molding member is released from the resin.
According to the above-described steps, a batch transfer of the fine structure is possible for the whole area of the surface (the surface having the surface structure (uneven structure) corresponding to the uneven structure formed on the surface of the cylindrical electrophotographic photosensitive member) of the molding member, and thus it is possible to process different workpieces separately (a batch method) according to the above-described steps. In sheet-like workpieces, while the workpieces are being moved, the transfer of the surface structure of the whole area of the surface (the surface having the uneven structure) of the molding member can be repeatedly performed (a step-and-repeat method). In the above-described steps, the heating steps and the cooling steps are important. When the heating temperature is low, there tends to occur a problem such that no sufficient surface structure transfer is able to be performed, and when the cooling is not sufficient, there tends to occur a problem such that the transferred surface structure is collapsed. Accordingly, the control conditions in the heating steps and the cooling step are preferably optimized in detail according to the different properties of the resin.
With respect to the temperature control of each of the members being processed, PTL 3 discloses the control methods focusing respectively on the molding member and the workpiece such as a resin film.
When the whole of the surface (the surface having an uneven structure) of the molding member is pressed against the workpiece, the uniformization of the abutting pressure within the area of the surface (the surface having an uneven structure) of the molding member is an important factor. The workpieces in the above-described conventional techniques are assumed to have flat plate shapes or to be flexible materials; however, in the cylindrical electrophotographic photosensitive member, which is the workpiece in the present invention, the surface to be processed has a curvature, and an object to be processed is a resin layer (a surface layer) having a thickness of a few microns to a few tens microns, formed on a cylindrical substrate being comparatively small in the elastic deformation magnitude and having a hardness. Accordingly, it is difficult to perform the contact between such a surface and the molding member, with a satisfactory precision.
For the purpose of overcoming this difficulty, various inventions and improvements have hitherto been made. Among such inventions and improvements, there is a method in which as shown in FIG. 3, a plate-like molding member 5 is bonded onto a flat-plate-like supporting member 13, and a columnar insert 12 is inserted into the interior of (made to pass through) a cylindrical electrophotographic photosensitive member 1, which is a workpiece. In this method, as described in PTL 3, by applying force (pressure), with some sort of unit, toward the molding member, on both end portions of the insert in the axial direction thereof, the surface layer 3 of a cylindrical substrate 2 of the cylindrical electrophotographic photosensitive member 1 is pressurized while being pressed against the molding member 5, across the width of the surface layer 3 along the axial direction of the cylindrical electrophotographic photosensitive member 1.
In this method, the outer diameter of the insert to be inserted into the cylindrical electrophotographic photosensitive member is required to be smaller than the inner diameter of the cylindrical substrate of the cylindrical electrophotographic photosensitive member as the workpiece. The length of the part of the insert, abutting on the cylindrical substrate, is required to be a length approximately corresponding to the length in the axial direction of the cylindrical substrate of the cylindrical electrophotographic photosensitive member. The shape of the insert satisfying such conditions is often long and thin. For example, the inner diameter of the cylindrical substrate of a common cylindrical electrophotographic photosensitive member of approximately 30 mm in inner diameter is approximately 28.5 mm, and the total length of the cylindrical substrate is approximately 360 mm when the cylindrical electrophotographic photosensitive member is to be used for the A3 paper size.
When force is applied to both end portions in the axial direction of such a long and thin insert so as to generate a pressure to press the surface (the outer peripheral surface) of the cylindrical electrophotographic photosensitive member against the molding member, such pressure tends to be unevenly applied to the vicinity of both end portions. Consequently, the depth of the uneven structure formed on the surface of the cylindrical electrophotographic photosensitive member is different, for example, in the vicinity of the central portion and in the vicinity of the end portions in the axial direction. For the purpose of suppressing such an uneven location of the pressure in the end portions and thus generating a uniform pressure distribution in the axial direction of the cylindrical electrophotographic photosensitive member, it is preferable to use an extremely firm member as the insert. Then, for the purpose of forming the insert so as to be firm, there can be used metal materials high in elastic modulus and hardness such as iron-base alloys, stainless steels and tungsten. Moreover, the shape of the insert is commonly a solid columnar shape but not a hollow columnar shape, for the purpose of more effectively ensuring the strength of the insert.

Process for forming uneven structure on surface of surface layer of cylindrical electrophotographic photosensitive member, and process for producing cylindrical electrophotographic photosensitive member having uneven structure formed on surface of surface layer of same


Lead assays using .delta. aminolevulinic acid dehydratase are disclosed.

The rapid and accurate measurement of lead in biologic, environmental and product materials is of major importance in public health and ultimately in the prevention of lead poisoning. Lead poisoning is caused solely by exposure to and absorption of the heavy metal. Lead may exist in various compound forms, such as oxides, halides, carbonates and acetates. Because it is lead itself that is toxic, the chemical and physical form of lead only slightly influences toxicity by modulating absorption and retention.
Lead poisoning is treatable poorly for two reasons: first, it is difficult to remove lead from critical target organs once it is absorbed; and second, some of the target organ damage induced by lead appear to be irreversible.
Prevention of lead poisoning requires two strategies to succeed: early detection of increased absorption and identification of lead in sources. Early detection is based on biological monitoring. Source identification is based on sampling air, drinking water, dusts, soils and food. For many children in the U.S., a major source of lead in dusts and soils is from old paint thereby making the measurement of lead in painted surfaces another priority. Also, for some environmental applications, measuring lead in soils, sediments and wastes is an important requirement.
Screening persons suspected to have been exposed to lead is based on two principles: measuring lead in blood, urine, bone, teeth or hair; and measuring biological markers or early cellular responses to lead. Direct measurement of lead requires collecting appropriate samples, extracting lead from the biological matrix and analyzing using atomic absorption spectrophotometry (AAS). The analytic phase requires laboratory support, investment in and maintenance of fixed laboratory equipment, skilled technical operators and inevitably delay between sampling people and obtaining an analytical result. For example see Pruszkowska et al. (1983) Atomic Spec. 4, pp. 59-61; and Barthel et al. (1973) J. A.O.A.C. V.56, No. 5.
Lead can also be measured in aqueous media, such as water and extracted blood, by electrochemical methods using a lead-specific electrode. The method is known as anodic stripping voltametry and (ASV) relies on the principle of measuring conductance changes associated with the plating and discharge of lead ions in solution. A portable ASV device is available, however, the method is limited in sensitivity.
An alternative method of screening for possible lead exposure was developed in the 1950's and is based on the effects of lead on cellular heme synthesis (in general, see papers in Silbergeld, EK & Fowler, BA (eds.) Mechanisms of Chemical-Induced Porphyrinopathies, Ann. NY Acad. Sci. (1987) v. 514). Lead is known to alter heme synthesis, common to many cells, at several steps. Because the pathway is under considerable internal feedback control, substantial alterations in the amounts of final product (heme) and various intermediates can be measured. Thus, measurement of aminolevulinic acid (ALA), coproporphyrins and protoporphyrin have been utilized as markers for lead poisoning. Also, activity of the rate-limiting enzyme, ALA dehydrase (ALAD), has been measured (see Doss; Marks et al.; Bernard & Lauwerys in Silbergeld and Fowler, supra).
In the early 1970's, Piomelli and coworkers demonstrated that measuring protoporphyrin in red cells was an accessible and reliable marker for lead exposure in children. Since that time, measuring protoporphyrin (frequently called erythrocyte protoporphyrin (EP) or "free" erythrocyte protoporphyrin (FEP)) is the standard method for screening children and adults for lead exposure. The EP assay requires small samples of blood collected by fingerstick and a portable instrument (the hematofluorometer) was built to provide an instant readout for purposes of clinic-based screening. Throughout the 1970's and 1980's, EP screening was the method of choice in public health to detect both childhood and occupational lead exposure.
However, it was known from the 1970's that there were significant limits to the utility of EP as a screening tool. For example, EP is influenced by iron status of individuals and EP does not rise significantly until blood lead levels are above 30 .mu.g/dl. (Micrograms per deciliter is the standard designation for blood lead concentrations; some authorities recommend using the international unit of micromolar, .mu.M; roughly, 20 .mu.g/dl equals 1 .mu.M.) Thus there are limits of both specificity and sensitivity with the EP assay.
Measuring lead in sources requires the appropriate sampling techniques, extraction of lead from environmental media or product matrices and analysis of lead by AAS. Before the development of AAS, lead was measured in a chemical reaction utilizing dithizone and formation of a lead-sulfide complex (see Chisolm et al. (1955) Amer. J. Disease of Children 89, pp. 159-168). Although the method has been replaced almost completely by AAS, a recent home test kit based on the dithizone reaction has been marketed for measuring lead leached from ceramics and cans (Frandon Enterprises). However, the test kit is considered by some to be unreliable.
Lead also can be analyzed by ion-coupled inductive plasma techniques and by x-ray induced fluorescence spectrophotometry. The former method is primarily a research tool and is used in studies, for example, of specific ion monitoring to determine sources of environmental contamination or of human exposure. The latter method has been adapted for use with portable equipment specifically detecting lead in painted surfaces such as interior woodwork. The sensitivity and reliability are less than ideal and furthermore, the equipment requires a radioactive source to generate x-rays.
Clearly current methods of lead assay are far from ideal. The shortcomings become amplified in view of recent developments in knowledge and public policy regarding lead that demand advances in screening and source identification. With respect to screening, it is generally recognized that lead toxicity occurs in children at blood lead levels as low as 10-15 .mu.g/dl. Although occupational health policy has not been updated since 1977 (the publication of the OSHA lead standard), recent data strongly indicates that an appropriate standard for preventing occupational lead poisoning is considerably lower than the current blood lead level of 40 .mu.g/dl (see Silbergeld et al. (1991), New Solutions, in press).
Recent surveys indicate that lead poisoning, defined as exposures resulting in blood lead levels in excess of 10-15 .mu.g/dl in children, is very prevalent in the U.S. (Agency for Toxic Substances and Disease Registry (ATSDR), Report to Congress on the Nature and Extent of Childhood Lead Poisoning, 1988). The problem has causes in the many widespread sources of lead in the environment, including the food supply. As a consequence, the Centers for Disease Control have recommended that all children be screened for lead exposure starting at 6 months of age and continuing at least yearly thereafter until age 6 (U.S. Public Health Service, Strategic Plan for the Elimination of Childhood Lead Poisoning, February 1991). Furthermore, increased surveillance of workers is clearly required to prevent occupational disease (Silbergeld et al., 1991, supra). Soon it is likely there will be recommendations to assess lead exposure in pregnant women and in the elderly based upon new epidemiologic studies on the effects of lead in those populations (Silbergeld, Environmental Health Perspectives 91: 156, 1990).
With respect to source identification, the recognition that lead at low doses is toxic necessarily results in the need to detect levels of lead in environmental and dietary sources at lower levels, and in the need to develop proactive programs of environmental monitoring of media such as dust and soils. As an example, the EPA has lowered the drinking water standard to an advisory level of 5 parts per billion (ppb), one-third of the current standard, and lowered the air standard from 1.5 .mu.g/cubic meter to 0.5 mg/cubic meter. Current federal and state guidelines for cleaning up contaminated dusts and soils range between 100 and 750 ppm (Reagan & Silbergeld, Trace Substances in Environmental Health in Environmental Geochemistry & Health (1990) 12, Suppl., 199-238). The FDA is proposing a lowered level for allowance leaching of lead from ceramic vessels.
At present there are no acceptable methods for identifying lead in humans or sources without laboratory based analytic support, almost always AAS, a resource intensive process. More significantly, for purposes of early detection and prevention, the need to send samples to a laboratory introduces substantial delays between sample collection and results. In screening programs the delay can be 1-3 months making it difficult to develop timely intervention and to implement treatment programs. Universal screening of all children is likely to be recommended. The impact on state and local screening programs will be enormous. Less than 5% of all children under 6 years currently are screened and almost all of the screening is done with EP as the first tier. The CDC have no recommendations as to alternate methods aside from venous blood and AAS and thus development of a new screening method is one of the highest priorities for eliminating lead poisoning (Public Health Service, 1991, Strategic Plan for Elimination of Childhood Lead Poisoning).
The criteria for a screening and detection method for lead exposure and of lead sources are those that relate to all such methods. First, the methods must be reliable and specific, that is, measure lead and not other metals, ions, or substances. The assays should not be confounded by commonly occurring conditions. Second, the assays must be appropriately sensitive, that is, generate a signal that detects lead or lead exposures at levels of current concern (for instance, in blood, concentrations of lead as low as 2-5 .mu.g/dl; concentrations in water as low as 1 ppb ) .
Additional criteria for screening and detection methods to be useful in public health include: the methods should produce results within the constraints of clinic and outpatient screening, that is, should utilize small amounts of sample (for instance, a fingerstick sample of blood or a single urine collection); should provide answers quickly within the clinic setting; should be relatively inexpensive; should be stable within a range of environmental settings, such as temperature; should be usable by persons with minimal technical training; and should be portable.


The infrared absorption filter of the present invention has a transmittance of not higher than 30% in the near-infrared region in the wavelength range of 800 to 1100 nm; a difference of 10% or less between a maximum value and a minimum value of transmittance in the visible light region in the wavelength range of 450 to 650 nm; and a transmittance of not lower than 50% at a wavelength of 550 nm, the filter being so excellent in environmental stability that after being left to stand in the air atmosphere at a temperature of 60° C. and a humidity of 95% for 1000 hours, the filter can maintain said spectral property in said range. Consequently, when used for a plasma display or the like, the filter can absorb the unwanted infrared rays radiated from the display, resulting in preventing erroneous operation of a remote control using infrared radiation even in such a high-temperature and high-humidity environment. The filter is gray in color so that when placed in front of a display, the color originated in the display can be seen without discoloration.

The following filters have been conventionally used as a heat ray-absorbing filter or as a filter for adjusting the visibility of video camera:                (1) a filter composed of phosphate glass containing metallic ions such as copper or iron ions (Japanese Unexamined Patent Publication No.235740/1985, Japanese Unexamined Patent Publication No.153144/1987, etc.);        (2) an interference filter having plural layers differing from each other in refractive index on a substance to allow light of specific wavelength to pass by interference of transmitted light (Japanese Unexamined Patent Publication No.21091/1980, Japanese Unexamined Patent Publication No.184745/1984, etc.);        (3) an acrylic resin filter composed of a copolymer containing copper ions (Japanese Unexamined Patent Publication No.324213/1994); and        (4) a filter composed of a binder resin and a coloring matter dispersed in the binder resin (Japanese Unexamined Patent Publication No.21458/1982, Japanese Unexamined Patent Publication No.198413/1982, Japanese Unexamined Patent Publication No.43605/1985, etc.).
The above-mentioned conventional infrared absorption filters have problems as described below.
The filter (1) exhibits sharp absorption in the near-infrared region and can intercept infrared radiation at a very high ratio. However, the filter (1) pronouncedly absorbs part of red color in the visible light region so that the transmitted color looks blue. For display purposes, importance is laid on a color balance. In such case, it is difficult to use the filter (1). Another problem is raised about the processability of the filter (1) because it is made of glass.
The optical properties of the filter (2) can be freely designed. Further a filter having properties almost equal to the designed properties can be produced. However, the filter (2) necessitates a plurality of layers differing in refractive index from each other for this purpose, consequently entailing a drawback of incurring high production costs. Moreover, when a large area is required, the filter (2) should have a uniform thickness of high precision over the entire area, resulting in a difficulty in producing the filter.
The filter (3) has improved processability compared with the filter (1). However, the filter (3) exhibits sharp absorption and absorbs the red color of light beams as is the case with the filter (1), raising the same problem as the filter (1) that the filter (3) looks blue.
In the filter (4), various infrared-absorbing materials can be used. Examples of useful materials are phthalocyanine, nickel complex, azo compound polymethine, diphenylmethane, triphenylmethane, quinone and the like. However, when singly used, these materials pose problems of showing insufficient absorption or absorbing a visible light of specific wavelength in the visible light region. Further, when the filter is left to stand at a high temperature or a high humidity for a long time, the infrared-absorbing materials involve problems of decomposing or oxidizing bringing about absorption in the visible light region or ceasing absorption in the infrared region.
An object of the present invention is to provide an infrared absorption filter which can achieve absorption in the near-infrared region, the filter showing a high transmittance in the visible light region, being free from marked absorption of a light of specific wavelength in the visible light region, and being excellent in environmental stability and in processability and productivity.


A computer-implemented method comprising: establishing, by an operation device, a wireless communication with a remote device; authenticating, by the operation device, the wireless communication with the remote device; receiving, at the operation device, a first command to perform a first operation; establishing a first maximum delay period using an estimated time delay, wherein the estimated time delay comprises an authentication delay, an encryption delay, or a combination thereof; determining, by the operation device, that the first command is received within a first maximum delay period; performing, by the operation device, the first operation; receiving, at the operation device, a second command to perform a second operation; establishing a second maximum delay period using the estimated time delay; determining, by the operation device, that the second command is received within a second maximum delay period; and performing, by the operation device, the second operation instructed in the second command.

Internet of things (IoT) devices have been an integral part of society. With virtually every electronic device communicating over some network variation, security has been an important factor for maintaining the functionality of IoT systems. Hackers have increasingly discovered ways to circumvent security features by devising new hacking techniques. One hacking technique, called delayed-message attacks, focuses on IoT devices and other wirelessly operating security systems.
The hacking technique is simple; an actor (or hacker) creates a man in the middle (MITM) device that is designed to intercept signals produced by authorized systems. When a user with an authorized device attempts to unlock a wireless locking mechanism, the MITM device receives the unlocking signal and withholds the signal from reaching the wireless locking mechanism. Once the user deems the locking mechanism unresponsive, the user abandons the area allowing the actor to release the message and gain access to whichever device was being unlocked by the user.
Therefore, there is a long felt and unresolved need for systems and methods that mitigate delayed-message attacks.

Systems and methods for delayed-message attack mitigation


In an ion implantation method of the present invention, an ion beam extracted from an ion source is implanted into a wafer by way of a plasma shower in a transportation section on the upstream side of the wafer. The plasma shower comprised of an arc chamber and a shower tube is arranged in a resolving aperture member or in the immediate vicinity of the downstream side.

1. Field of the Invention
The present invention relates to an ion implantation apparatus and an ion implantation method.
2. Description of the Related Art
The following will describe a typical configuration of an ion implantation apparatus with reference to FIG. 1. In FIG. 1, ions are extracted as an ion beam 52 by an extraction electrode 51 from an ion source 50. The extracted ions are analyzed by a mass analysis magnet 53 and a resolving aperture member 54 and a required ion species is selected. The selected ions are implanted into a wafer 55. The resolving aperture member 54 serves as a mass analysis slit. On a beam line, a shower tube 56 for showering plasma is arranged between the resolving aperture member 54 and the wafer 55. The shower tube 56 is mounted with an arc chamber 57. The arc chamber 57 has an opening therein which faces the beam line side. A Faraday cup 58 for use in measurement of a beam current is provided in such a manner that it can advance onto and retreat from the beam line. That is, the Faraday cup 58 is placed on the beam line when the ion beam is set up (as indicated by a dash-and-dot line in FIG. 1) and placed off from the beam line at the position of a solid line in FIG. 1 when the ions are being implanted. On the back side of the wafer 55, a Faraday cup 59 is arranged so that measurement may be possible during ion implantation.
FIG. 2 is an enlarged view for showing the downstream side of the resolving aperture member 54 in FIG. 1. Although not shown in FIG. 1, components shown in FIG. 1 are arranged in a vacuum chamber 60 as shown in FIG. 2. The arc chamber 57 incorporates therein a filament 57-1. To the filament 57-1 are there connected a filament power source 57-2 and an arc power source 57-3. Furthermore, the arc chamber 57 is arranged in such a manner that a predetermined gas can be introduced into it from a gas supply system 57-4. The shower tube 56, the arc chamber 57, and the arc power source 57-3 are each connected to the ground. In this configuration, in the immediate vicinity of the downstream side of the resolving aperture member 54 is there arranged at least one aperture member 61. The Faraday cup 58 can be advanced onto and retreated from the beam line by a drive device 63 which is mounted outside the vacuum chamber 60.
The following will describe a method of extraction of electrons from the plasma shower. The electrons are specifically extracted from the plasma shower as follows.
(1) Generation of Arc
When a large current is flown through the filament 57-1, the filament 57-1 is heated to 2000xc2x0 C. or higher, to emit thermions. The arc chamber 57 is supplied with a gas such as Ar from the gas supply system 57-4 and also supplied with an arc voltage of a few tens of volts with respect to the filament 57-1. Then, the thermions are accelerated to collide with atoms of the gas, thus generating new thermions. This electron amplification action generates plasma between the filament 57-1 and the arc chamber 57.
(2) Extraction of Electrons by Use of Beam Potential
When an ion beam passes by outside the opening in the arc chamber 57 in a condition where plasma is being generated stably in the arc chamber 57, a positive potential of the ion beam extracts electrons from the plasma which is present in the arc chamber 57. These extracted electrons are accelerated toward the ion beam. These electrons collide with neutral gas atoms which have not been ionized in the arc chamber 57 and ejected through the opening in the arc chamber 57, thus generating plasma again between the arc chamber 57 and the ion beam. This is called a plasma bridge (which is indicated by a reference numeral 65) and has an effect of supplying the ion beam with such a quantity of electrons as to exceed a space charge limited current.
Next, characteristics of extraction of electrons from a plasma shower are described. For example, if the magnitude of a beam current increases, the positive potential of the ion beam increases. As a result, the quantity of electrons which are extracted from the arc chamber 57 increases, thus increasing also the quantity of electrons which are supplied to the ion beam. By such autonomous control, in a plasma shower system, electrons which are abundant enough to neutralize the positive charge of the ion beam are extracted from the plasma shower, thus restraining the positive charging of the wafer 55. That is, the plasma shower system comprised of the shower tube 56 and the arc chamber 57 serves as a charge neutralization apparatus which is for restraining charge.
The following will describe various problems of the above-mentioned conventional technologies.
(1) Effects of Ion Beam Diameter
An ion implantation apparatus employs an ion beam of a variety of ion species, energy levels, and beam currents. The diameter of such an ion beam varies with beam conditions and beam generating conditions.
The arc chamber 57 is mounted at such a position that it may not be collided with an ion beam which has the maximum design diameter. This is done so in order to prevent such a problem from occurring that the beam current would decrease or particles would be generated if the ion beam collides with the arc chamber 57.
If a beam diameter D1 varies at the position of the arc chamber 57, a distance between the opening in the arc chamber 57 and the ion beam also varies and hence the magnitude of an electric field varies. Accordingly, if the beam diameter D1 varies, the quantity of electrons which are supplied to the ion beam varies. For example, if such beam conditions are applied that the beam diameter D1 is liable to decrease, there occurs an insufficiency in quantity of electrons which are supplied from the plasma shower, thus making it impossible to sufficiently suppress positive charging of the wafer 55 in some cases. In order to solve this problem, there may be considered such a method as to vary the power of the plasma shower corresponding to the beam diameter D1. This method, however, requires for its implementation a beam diameter measurement mechanism, a feedback circuit, etc., thus complicating the plasma shower system more than necessary.
(2) Effects of Position of the Arc Chamber 57
The plasma shower is normally arranged on the downstream side of the resolving aperture member 54 where the ion beam is converged, for example, between the wafer 55 and a suppression electrode, that is, the aperture member 61. The plasma shower, however, may be arranged in some cases in the immediate vicinity the wafer 55 so that the wafer may be supplied with electrons easily.
As is clear from FIG. 2, a variation d1 in value of the beam diameter D1 at the position of the plasma shower increases as the plasma shower becomes more distant from the resolving aperture member 54 in a beam axial direction. Accordingly, as the distance between the arc chamber 57 and the ion beam increases in a condition where the arc chamber 57 is separated from the resolving aperture member 54, the quantity of electrons which are supplied from the plasma shower becomes insufficient, thus making it impossible to suppress positive charging of the wafer 55 in some cases.
Next, the Faraday cup 58 is described.
(1) Device Layout Along the Beam Line
As described above, on the downstream side of the resolving aperture member 54 is there arranged the Faraday cup 58 to measure a beam current when the ion beam is set up. The Faraday cup 58 is intended to monitor the beam current, to adjust ion source parameters, thus obtaining a desired ion beam. Furthermore, on the downstream side of the Faraday cup 58, that is, between the Faraday cup 58 and the wafer 55 is there arranged the shower tube 56 to shower plasma, which serves as a charge neutralization apparatus.
When the ion beam is set up completely, the Faraday cup 58 is moved off from the beam line. Then, the ion beam passes through the plasma shower and is transported to the wafer 55, where the ions are implanted into the wafer 55.
It is to be noted that after passing through the resolving aperture member 54, the ion beam diverges. For this reason, as the distance between the resolving aperture member 54 and the wafer 55 increases, the ion beam comes to collide with the shower tube 56 etc., thus being lost more. This loss increases particularly with a low energy beam, thus leading to such a problem in some cases that a throughput may decrease owing to a decrease in the magnitude of the beam current or the ion beam may collide with the shower tube 56 etc.
One of the factors for an elongated distance between the resolving aperture member 54 and the wafer 55 is a problem of an arrangement of the Faraday cup 58 in the beam line. The Faraday cup 58 is moved in such a manner that it may be used only when the ion beam is being set up and, during ion implantation, be moved off from the beam line. The region in the beam line in which the Faraday cup 58 exists becomes a blank when the ions being implanted, thus elongating the beam line.
In view of the above, it is an object of the present invention to provide an ion implantation apparatus and method which can avoid extraction of electrons from a plasma shower from being influenced by a variation in ion beam diameter.
It is another object of the present invention to provide an ion implantation apparatus and method which can suppress loss of an ion beam particularly at a low energy level.
In an ion implantation method to which the present invention is applied, when an ion beam extracted from a ion source is transported to be implanted into a processing-subject substrate, the ion beam is caused to pass through a charge neutralization section in a transportation section on the upstream side of the processing-subject substrate.
An ion implantation method according to an aspect of the present invention features that an ion beam is neutralized by a charge neutralization section at such a position that it is brought nearest the ion beam.
This position which is nearest the ion beam in the present ion implantation method is intended to be such a position that the beam diameter may be smallest there or to be in the immediate vicinity of the downstream side of the position.
In the present ion implantation method, the position which is nearest the ion beam is intended to be a position in the immediate vicinity of the downstream side of a position where the beam diameter becomes smallest and also the position of the charge neutralization section is intended to be variable corresponding to the beam diameter.
In the present ion implantation method, furthermore, on the upstream side of the charge neutralization section is there arranged a resolving aperture member for converging and diverging a beam. Accordingly, the position in the immediate vicinity of the downstream side of a position where the beam diameter becomes the smallest is intended to be on the downstream side of the resolving aperture member.
In the present ion implantation method, furthermore, the charge neutralization section includes a shower tube and an arc chamber combined therewith. A length of the shower tube is made shorter in a beam axis direction.
In the present ion implantation method, furthermore, the shower tube has a minimum required inner diameter.
In the present ion implantation method, furthermore, along a beam line between the shower tube and a processing-subject wafer may there be arranged an intermediate tube in such a manner as to continue to the shower tube.
In the present ion implantation method, furthermore, the arc chamber may be variable in position in a direction perpendicular to a beam axis corresponding to a beam diameter or intensity.
In the present ion implantation method, furthermore, the arc chamber may be variable in position in the beam axis direction corresponding to a beam diameter or intensity, so as to be arranged nearest the ion beam.
In the present ion implantation method, furthermore, the diameter of the shower tube may be variable corresponding to a beam shape, position, or size.
In the present ion implantation method, furthermore, the length of the shower tube may be variable corresponding to a beam shape, position, or size.
In the present ion implantation method, furthermore, the shower tube may be variable in position in the beam axis direction corresponding to a beam shape, position, or size.
In the present ion implantation method, furthermore, a beam measurement portion may be arranged in a transportation section on the upstream side of a processing-subject substrate. In this case, the beam measurement portion and the charge neutralization section may be interchangeable at the same position on the beam line.
In the present ion implantation method, furthermore, on the upstream side of the charge neutralization section may there be arranged the beam convergence/resolution resolving aperture member. Accordingly, the position which is nearest the ion beam may be present in the resolving aperture member. In this case, on the downstream side of the resolving aperture member is there provided a beam measurement portion in such a manner that it can advance onto and retreat from the beam line. In this case, furthermore, on the downstream side of the resolving aperture member may there be arranged an intermediate tube.
In an ion implantation apparatus to which the present invention is applied, when an ion beam extracted from a ion source is transported to be implanted into a processing-subject substrate, the ion beam is caused to pass through a charge neutralization section in a transportation section on the upstream side of the processing-subject substrate.
The ion implantation apparatus according to an aspect of the present invention features that the charge neutralization section is arranged at a position which is nearest the ion beam.
In the present ion implantation apparatus, the position which is nearest the ion beam is intended to be such a position that the beam diameter may be smallest there or to be its immediate vicinity of the downstream side of the position.
In the present ion implantation apparatus, the position which is nearest the ion beam is intended to be such a position in the immediate vicinity of the downstream side that the beam diameter may be the smallest. Furthermore, the present ion implantation apparatus is provided with a drive unit which makes the position of the charge neutralization section variable corresponding to the beam diameter.
In the present ion implantation apparatus, furthermore, on the upstream side of the charge neutralization section is there arranged the resolving aperture member for converging and diverging the ion beam. Accordingly, the position in the immediate vicinity of the downstream side of a position where the beam diameter becomes the smallest is intended to be on the downstream side of the resolving aperture member.
In the present ion implantation apparatus, furthermore, the charge neutralization section includes the shower tube and the arc chamber combined therewith. A length of the shower tube is made shorter in a beam axis direction.
In the present ion implantation apparatus, furthermore, the shower tube has a minimum required inner diameter.
In the present ion implantation apparatus, furthermore, along a beam line between the shower tube and a processing-subject wafer may there be arranged the intermediate tube in such a manner as to continue to the shower tube.
In the present ion implantation apparatus, furthermore, the drive unit includes a drive mechanism which makes variable the position of the arc chamber in the direction perpendicular to the beam axis corresponding to the beam diameter or intensity.
In the present ion implantation apparatus, furthermore, the drive unit includes a drive mechanism which makes variable the position of the arc chamber in the same direction as the beam axis direction corresponding to the beam diameter or intensity. In this case, the arc chamber can be arranged at a position which is nearest the ion beam.
In the present ion implantation apparatus, furthermore, the shower tube may be comprised of at least two members which are divided in the same direction as the beam axis direction. In this case, one of these at least two divided members has a cross section which is a little smaller than that of the other. The drive unit may include a drive mechanism which makes variable the diameter of the shower tube by bringing these two divided members close to or separate them from each other corresponding to the beam shape, position, or size.
In the present ion implantation apparatus, furthermore, the shower tube may be comprised of at least two members which are divided in a direction perpendicular to the beam axis. In this case, one of these at least two divided members has a diameter which is a little smaller than that of the other. The drive portion may include a drive mechanism which makes variable the length of the shower tube by moving at least one of these two divided members in the beam axis direction corresponding to the beam shape, position, or size.
In the present ion implantation apparatus, furthermore, the drive unit may include a drive mechanism which makes variable the position of the shower tube in the same direction as the beam axis direction corresponding to the beam shape, position, or size.
In the present ion implantation apparatus, furthermore, the beam measurement portion may be arranged in a transportation section on the upstream side of a processing-subject substrate. Moreover, an interchanging drive device is provided which makes it possible to interchange the beam measurement portion and the charge neutralization section with each other at the same position on the beam line.
In the present ion implantation apparatus, furthermore, on the upstream side of the charge neutralization section is there arranged the beam convergence/resolution resolving aperture member. In this case, the position which is nearest the ion beam may be present in the resolving aperture member. In this case, on the downstream side of the resolving aperture member may there be provided a beam measurement portion in such a manner that it can advance onto and retreat from the beam line. In this case, furthermore, on the downstream side of the resolving aperture member may there be arranged the intermediate tube.

Ion implantation apparatus equipped with plasma shower and ion implantation method


In the computer interpretation of seismic data, the critical first step is to identify the general class of an unknown event. For example, the classification might be: teleseismic, regional, local, vehicular, or noise. Self-organizing neural networks (SONNs) can be used for classifying such events. Both Kohonen and Adaptive Resonance Theory (ART) SONNs are useful for this purpose. Given the detection of a seismic event and the corresponding signal, computation is made of: the time-frequency distribution, its binary representation, and finally a shift-invariant representation, which is the magnitude of the two-dimensional Fourier transform (2-D FFT) of the binary time-frequency distribution. This pre-processed input is fed into the SONNs. These neural networks are able to group events that look similar. The ART SONN has an advantage in classifying the event because the types of cluster groups do not need to be pre-defined. The results from the SONNs together with an expert seismologist's classification are then used to derive event classification probabilities.

1. Field of the Invention
This invention relates generally to the identification and classification of seismic sources using transient signals recorded passively with geophones or seismometers. More specifically, the invention derives seismic event classification probabilities by computing a time-frequency distribution, filtering out 2-dimensional noise, computing a binary and then a shift-invariant representation, and finally employing a self-organizing neural network for source identification.
2. Description of Related Art
Monitoring networks of seismic stations detect hundreds of thousands of seismic events annually. A variety of types of sources are responsible for these events which are detected and recorded by world wide seismic networks. Typical seismic sources include earthquakes, underground nuclear explosions, mining shots, cultural activities such as moving trucks or trains, and natural noise sources such as the wind, ocean waves, or the breaking of glaciers. To verify nuclear test ban treaties, all events detected by monitoring networks must be analyzed. Because of the large number of events that need to be identified, the problem requires an automated analysis platform. The various methods used in prior knowledge-based or expert systems have been only partially successful in automating seismic signal interpretation. This is because data characteristics vary significantly from event to event and because the solution is difficult to describe with a finite set of rules that are commonly used in conventional knowledge-based expert systems.
Different systems have been developed which classify and identify seismic sources. The following patents and articles describe these systems.
U.S. Pat. No. 4,713,775 is directed to an intelligent assistant system for using and operating computer system capabilities to solve problems. The patent uses some concepts of artificial intelligence to solve problems, however, the seismic event classification system. (SECs) described is an invention for interpreting seismic events. SECs interpret an event in the presence of varying noise by incorporating signal processing, neural networks, image understanding and a production rule system. The problem with static correction of seismic reflection data described in the patent is a highly specialized algorithm for a completely different problem than that of seismic event interpretation.
U.S. Pat. No. 4,939,648 is directed to a method and apparatus for monitoring well logging information. The patent uses signal processing on time series signals. SECs use a neural network to do pattern recognition. The patent uses observations related to situations in a knowledge base to do pattern recognition. The problem addressed in the patent is specific to well logging instrumentation and analysis.
An article by J. Bitto et al., entitled "Seismic Event Discrimination Using Neural Networks," 23rd Asilomar Conference on Signals, Systems, and Computers, Vol. 1, pp. 326-330, November 1989, describes a method used to discriminate between two known classes of events, for example earthquakes and nuclear tests. It describes use of a one-dimensional correlation of the data with supervised back propagation. SECs interpret any seismic event in the presence of varying noise by incorporating two-dimensional spectral estimation of a non-stationary process, making use of an unsupervised self-organizing neural network, using image understanding and production rule systems.
In the article by H. Liu, entitled "A Rule-Based System for Automatic Seismic Discrimination," Pattern Recognition, Vol. 18, No. 6, pp. 459-463, (1985), artificial intelligence technology is proposed. This paper is a proposal to solve a seismic discrimination problem using rules. The paper generally surveys the subject of seismic event discrimination for treaty verification, rule based systems, and a paragraph on pattern recognition.
In the article by I. Palaz et al., entitled "Waveform recognition Using Neural Networks," Geophysics: The Leading Edge of Exploration, Round Table, March 1990, supervised back propagation neural networks are proposed to recognize waveforms. The paper does not describe a method for interpretation of an event in the presence of noise by incorporating a number of new technologies.
SEC's combine a number of technologies and novel algorithms to interpret seismic events using pattern recognition techniques and high level reasoning. All of the above papers and patents are related by only a key word or by use of a particular technology.
Often, only human analysts are able to classify seismic events based on their experience of looking at many seismic events. The basic principle of this invention was motivated by how a human expert views the entire segment of a detected seismic waveform, using both seismic phase and the coda characteristics of the transient signals, to classify a given event.
It is proposed that with the proper representation of the seismic signal and by employing the machine learning properties of a self-organizing neural network, automation of seismic event classification can be achieved. The present invention provides such a method and article.


A duplication detection module may be configured to determine if data on a RFID tag is encoded. If the data on the RFID tag is not encoded, the duplication detection module may determine that the RFID tag is a duplicate RFID tag and that an item associated with the duplicate RFID tag is counterfeit. If the data on the RFID tag is encoded, the duplication detection module may cause the decoder to decode the data on the RFID tag using a private key of a receiving party as a decoding parameter. The module may check for an item identifier and a sender identifier as a part of the encoded data, determine whether the item identifier has previously been read to determine if the RFID tag was duplicated during transport and compare the sender identifier with an expected sender identifier to determine if the RFID tag was duplicated during transport.

With the globalization of production and trade, counterfeiting of products has become a serious problem. One approach to fight counterfeiting is the use of technical countermeasures. For example, a common approach is equipping products with security features and using backend software for the verification of the security-equipped products, i.e., giving an answer to the question whether a product is genuine or counterfeit. This approach may be referred to as product authentication.
In one example, RFID tags may be used as an enabler for product authentication. For instance, the RFID tags may be attached to products and may enable the unique identification of products at an instance level. This means a RFID tag may be attached to each product instance ("item") and the RFID tag may store specific data for the respective product instance or item.
Although the use of RFID tags has the potential to enable product authentication, one or more potential issues may have to be overcome in order for the use of RFID tags to reveal its full strength. One issue, for example, is RFID tag duplication. Tag duplication means reading data of one RFID tag and writing the same data to another RFID tag. In the context of counterfeiting, an adversary may read the RFID tag of a genuine item and write identical data to a RFID tag attached to a counterfeit item, with the intention of circumventing product authentication mechanisms. Consequently, solutions are needed to overcome this issue related to RFID tag duplication as well as other issues.

Duplication detection for non-cryptographic RFID tags using encrypted traceability information


Friction control articles for use in healthcare applications, the articles generally comprising a backing Layer having a first surface and a second surface, where projecting from the first surface of the backing layer is an array of stems, wherein at least a portion of the exterior surface of the stems comprises an elastomeric material. Also disclosed are friction control articles having a coefficient of friction when dry along at least a portion of the first surface of at least 0.6. Multilayered and dual-sided friction control articles are also provided.

The development of enhanced grip and anti-slip surfaces typically centers around the materials and the surface topology of the article. Common materials include natural and synthetic rubbers, styrenic block co-polymers, latex, ethylene vinyl acetate, ethylene-propylene rubber, polyurethane, polyester co-polymers, polyimides, and the like. The surface topology can range from smooth to having exaggerated gripping structures. U.S. Pat. No. 3,585,101 discloses a thin sheet of a soft, ductile, flexible material, such as aluminum, brass, plastic or the like, having a knurled pattern embossed to provide an improved gripping surface. The sheet can be applied to solid objects using an adhesive.
U.S. Pat. No. 4,488,918 discloses a plastic film having a non-slip surface comprising spaced, random patterns of rigid peaks and ridges formed of a second thermoplastic material co-extruded with and bonded to a plastic film. The surface has a pattern of relatively high, sharp, irregular plastic peaks and ridges, sufficiently sharp, hard and rough to effect a mechanical gripping with other surfaces.
U.S. Pat. No. 5,234,740 discloses a slip control surface with a structured surface. The structured surface includes an array of protrusions, typically triangular pyramids. The patent discloses that the sheeting may be applied to the handles of athletic equipment such as softball bats, golf clubs, tennis, racquetball, squash, badminton racquets, as well as the handles of tools.
In medical and other healthcare environments, draping articles are often used to cover irregular surfaces onto which instruments and other surgical and medical implements are placed. It would be desirable to secure such implements to the surfaces of such drapes for temporary placement during a procedure without the need for adhesives (which can leave residue) or without the use of magnets (which can magnetize metal instruments). It would also be desirable to have a multi-purpose, conformable high friction surface that can be readily sterilized and can be used in a multitude of applications in healthcare facilities.

This patent is subject to a terminal disclaimer.

Friction control articles for healthcare applications