Improvements in the perpendicular magnetic recording and reproducing head of the type in which a main magnetic pole and an auxiliary magnetic pole are arranged as a unitary structure on one side of a magnetic recording medium. Problems are solved in relation to pseudo pulses in the output signals and change in the level, contributing to improving the sensitivity for recording and reproduction. The magnetic head is used for perpendicular VTR's. The perpendicular magnetic recording and reproducing head of the invention comprises a support block which consists of a main magnetic pole, a non-magnetic block which holds said main magnetic pole to form a surface opposed to the magnetic recording medium, and an auxiliary magnetic pole block which supports part of said main magnetic pole and which supports said non-magnetic block; and a magnetic block provided on the side surface of said support block in the direction of track width. The region opposed to the magnetic recording medium is constitued by the main magnetic pole, non-magnetic block and magnetic block.

A conventional perpendicular magnetic recording and reproducing head of this kind has, as shown in FIG. 12, a structure in which non-magnetic blocks 6 and 6 having a suitable thickness and for providing the opposed surface are joined to the tops of auxiliary magnetic pole blocks 1a and 1b, each of the blocks 1a and 1b having a window 2 for coil winding use, to form a pair of support blocks 4 and 4, a main magnetic pole 3 is held between the pair of support blocks 4 and 4 to form a core chip 1, and the coil is wound through the coil winding windows 2 after the surfaces of the non-magnetic blocks 6 and 6 are polished into a spherical or similar form to be contacted with or opposed to a magnetic recording medium (Patent unexamined publication No. 40314/84 (TOKKAI Sho 59-40314)).
With the magnetic head of the above structure, a magnetic tape, magnetic disk or like magnetic recording medium is driven in sliding contact with or at a predetermined distance from the opposed area A centering about the main magnetic pole 3. Consequently, when a recording signal is applied to the coil and the main magnetic pole 3 is excited accordingly, a magnetic flux is induced from the main magnetic pole 3, by which a magnetic layer of that portion of the perpendicular magnetic recording medium which is being opposed to the upper end face of the main magnetic pole 3 is magnetized in a perpendicular direction. That is, magnetic flux flow circuit is established in which the magnetic flux emanating from the main magnetic pole 3 returns thereto via a route [the magnetic layer of the magnetic recording medium.fwdarw.a soft magnetic layer of the magnetic recording medium.fwdarw.the magnetic layer.fwdarw.an air gap (between the surfaces of the non-magnetic blocks 6, 6 and the magnetic recording medium).fwdarw.the non-magnetic blocks 6, 6.fwdarw.return path portions 1c and 1d of the auxiliary magnetic pole blocks 1a and 1b.fwdarw.main magnetic pole holding portions 1e and 1f]. During reproducing a magnetic flux flow circuit is provided in which a signal current is applied to the coil 5 by a signal recorded in the magnetic layer of the magnetic recording medium via a route reverse from the above-mentioned one for magnetic recording.
In this kind of head, the primary factor that determines its recording and reproducing sensitivity depends on the reluctance of the magnetic flux flow circuit. In other words, the smaller the reluctance is, the more the recording and reproducing sensitivity increases.
In the conventional perpendicular magnetic recording and reproducing head, however, it is difficult to increase the recording and reproducing sensitivity, because the magnetic flux flow circuit includes the air gap and the non-magnetic blocks 6 and therefore has a large reluctance.
To decrease the reluctance, it is also possible, for instance, in the prior art example of FIG. 12, to adopt an arrangement in which the return path portions 1c and 1d of the auxiliary magnetic pole blocks 1a and 1b are directly opposed to the magnetic recording medium with no non-magnetic blocks 6 and 6 interposed therebetween so that the magnetic recording medium is driven in direct sliding contact with or at a predetermined distance from the return path portions. In this instance, however, edges 1g and 1h of the return path portions 1c and 1d are exposed to the magnetic recording medium and perform the function of what is called a pseudo magnetic recording and reproducing gap, inevitably producing an adverse effect of introducing pseudo pulses into the signal output.
Furthermore, if the condition of contact between the magnetic recording medium and the magnetic head, for example, the contact pressure therebetween or the infeed of the magnetic head to the magnetic recording medium, is changed by any unsuspected reason, the distance between the magnetic recording medium and the return path portions 1c and 1d also changes, posing problems such as fluctuations in the output signal level because of the fluctuations of the reluctance.

Perpendicular magnetic recording and reproducing head

Kabushiki Kaisha Sankyo Seiki Seisakusho


A reading apparatus configured to read a plurality of colorimetric patches in different colors formed on a paper sheet and trigger patches formed so as to correspond to the colorimetric patches includes: a colorimeter configured to read the colorimetric patches; a trigger sensor configured to read the trigger patches; and a controller configured to control a reading region, wherein the controller has a colorimetry region determination mode in which the reading region is determined and a colorimetry adjustment mode in which the reading region is controlled, and in the colorimetry region determination mode, after the reading regions are set to states where the reading regions are gradually shifted in a reading direction, the reading results for the colorimetric patches are collected and thereafter, a region for which a state consistent with a characteristic of the colorimetric patch has been obtained as the reading result is determined as the reading region.

Field of the Invention
The present invention relates to a technique of properly reading a plurality of colorimetric patches formed on a colorimetric chart when image formation is adjusted in an image formation apparatus.
Description of the Related Art
An image formation system has been known in which a reading apparatus (output object reading apparatus) is connected to a latter stage of an image formation apparatus configured to form an image on a paper sheet such that the image on the paper sheet obtained as a result of the image formation is read by the reading apparatus. Similarly, an image formation apparatus has been known in which a reading unit (output object reading unit) is arranged on a downstream side of an image formation unit configured to form an image on a paper sheet such that the image on the paper sheet obtained as a result of the image formation is read by the reading unit.
The image formation apparatus such as a printer or a multi-functional peripheral is provided with an image adjustment mode. In this image adjustment mode, in order to enhance the quality of an output image, a colorimetric patch has been conventionally printed in color to provide a function of detecting this colorimetric patch by using an RGB color density sensor or the like to compare with original print data and, when a difference therebetween is observed, correcting print density and so on while forming an image.
Preferably, in order to decrease the number of paper sheets for the adjustment, the size of the colorimetric patch to be printed on the paper sheet during such an image adjustment mode is made as small as possible with respect to a paper sheet conveying direction such that a large number of the colorimetric patches can be formed on one paper sheet.
In recent years, in order to reduce an image adjustment period or the like for further enhancement of the image quality, an image reading apparatus including an image formation apparatus equipped with an inline image scanner has appeared. This image scanner can be used to correct a position shift between a front side and a rear side of a sheet, image density, a color tone, and the like in regard to the output image in real time.
Additionally, equipping an inline spectrophotometer for accurately measuring the color tone to correct an absolute color on print data can contribute to further reduction of the adjustment period. Because the image scanner can detect the patches on the entire surface of the paper sheet, by understanding a correlation between a true color tone acquired by the spectrophotometer and color data acquired by the image scanner to correct the image scanner, the patches can be actually formed on the entire surface of the paper sheet, whereby the paper sheet for the adjustment can be saved in turn. Alternatively, when the spectrophotometer alone is connected inline to the image formation apparatus such that the colorimetry is carried out on the patch on the paper sheet while being conveyed, effects of the period reduction and so on can be achieved as a consequence of automated adjustment.
In a case where the spectrophotometer is used, a configuration is employed in which reflected light of respective components of separated light is arithmetically calculated into L*a*b* color space data or XYZ color space data, whereby the color tone is deduced. The patch for which the colorimetry is to be carried out for a visible light source is irradiated by the spectrophotometer such that an optical spectrum of the reflected light is acquired. Additionally, in some cases, in order to exclude the influence of a fluorescent agent in the paper sheet for colorimetry and consequently obtain more accurate colorimetry, reflected light of an ultraviolet light source is acquired so as to be subjected to the arithmetic calculation.
Here, the size of a colorimetric patch P formed on a paper sheet P will be described with reference to FIG. 19. In a typical spectrophotometer, a lens unit configured to acquire the reflected light is approximately 4 mm, while a measurement diameter φ is also approximately 4 mm on the colorimetric patch.
Accordingly, a patch size PTsize_H of the colorimetric patch is required to have 4 mm+α per one colorimeter with respect to a paper sheet width direction (a direction perpendicularly intersecting the paper sheet conveying direction).
In addition, with respect to a paper sheet length direction (paper sheet conveying direction), the colorimetric patch is required to have a patch size PTsize_V=φ+mv+2 mg obtained by adding a movement distance my of the paper sheet P corresponding to a measurement period, the measurement diameter φ, and a margin mg.
The spectrophotometer is constituted by an exposure unit configured by an LED or the like, a diffraction grating configured to separate light, a CMOS sensor configured to detect the reflected light of the separated light, a signal output unit configured to output a detection result in accordance with a wavelength, and so on. The typical spectrophotometer uses the CMOS sensor or the like to collect the reflected light that has been separated in units of 10 nm in a range of 380 nm to 730 nm. Exposure by the LED or the like continues for a predetermined period during colorimetry. When the reflected light is not collected for the predetermined period, precise colorimetry cannot be achieved. In order to enhance the stability in repeated colorimetry, it is further preferable to take an integrated average of several times. The separated light reflection data obtained here is stored to a memory of the colorimeter and at the same time, subjected to arithmetic calculation processing into a colorimetric value in L*a*b* or the like. Results of these series of the processing are temporarily stored to a RAM and held until being transmitted to the reading apparatus.
Here, when a colorimetry period and the colorimetric patch on the moving paper sheet during colorimetry is considered in accordance with the typical spectrophotometer as a reference, the measurement diameter φ needs to be 4 mm, the colorimetry period needs to be 10 ms, and an analog amount of the reflected light needs to be equal to or larger than 1.3 ms when converted to a digital value. When a conveying speed of the paper sheet is assumed as 300 mm/s, a movement amount while the colorimetry is carried out one time is found out to be approximately 3.4 mm. Accordingly, the necessary patch size at least requires 7.4 mm, where 4 mm of the measurement diameter φ has been added. In other words, resolution for the colorimetry of the colorimetric patch is found out to be 7.4 mm in the paper sheet conveying direction.
Additionally, regarding the colorimetric patch described above, it is important to align a timing at the spectrophotometer between two adjacent colorimetric patches such that the colorimetry is carried out for each of the colorimetric patches without spanning across both of the colorimetric patches. As for techniques in this field, various types of relevant proposals are described in JP 2006-251652 A and JP 2000-39747 A.
(1) In JP 2006-251652 A, as illustrated in FIG. 20, a paper sheet conveying sensor 199 is controlled to detect a leading edge of a paper sheet while being conveyed, form a trigger signal with a predetermined timer, and carry out the colorimetry on each of colorimetric patches. In this case, due to deviations on an image formation side such as a blank space at the leading edge of the paper sheet (a distance from the leading edge of the paper sheet to the colorimetric patch) and printing magnification, a timing from the leading edge of the paper sheet to each of the colorimetric patches is to be slightly changed. Therefore, it is required to enlarge a patch size.
(2) JP 2000-39747 A employs a control approach in which a spectrophotometer judges a boundary of each of colorimetric patches by itself to start the colorimetry. In this case, a color difference (including differences in saturation and brightness) equal to or larger than a certain degree is required between respective patches. This accordingly causes a limitation on the arrangement of the colorimetric patches on a chart. In addition, an unavailable combination of the colorimetric patches has a possibility of occurring. Therefore, it is required to enlarge the colorimetric patch such that whether the boundary of each of colorimetric patches is certainly passed can be determined with ease.
(3) As illustrated in FIG. 21 and FIG. 22, another approach is also considered in which trigger patches are formed in advance so as to be synchronized with the colorimetric patches in the conveying direction on the paper sheet P such that a trigger sensor 190a detects the trigger patch and, in accordance with this detection of the trigger patch, a spectrophotometer 190b carries out the colorimetry on the colorimetric patch. In this case, the trigger patch serving as a reference point is prepared for each of the colorimetric patches and thus, it is made possible to precisely pinpoint the colorimetric patch while the colorimetry is carried out thereon almost without being affected by the blank space at the leading edge or printing magnification.
As described thus far, in the cases of (1) and (2), there has been a problem where the colorimetric patch is required to be enlarged. On the other hand, in the case of (3), the colorimetric patch is not required to be enlarged and it seems that the colorimetry can be precisely carried out on the colorimetric patch.
According to the verification by the inventors of the present application, however, it has been found that even the above-described approach (3) has problems caused during manufacturing, for example, a positional difference in the paper sheet conveying direction between the trigger sensor 190a and the spectrophotometer 190b (refer to FIG. 21) and a difference in detection directivity in the paper sheet conveying direction between the trigger sensor 190a and the spectrophotometer 190b (refer to FIG. 22).
For a remedy for this, a calibration is required in such a manner that, for example, a position where the trigger sensor is activated is measured with a scale while the trigger patch is moved in units of 0.1 mm and recorded for each of the sensors; thereafter, on the basis of the recorded positions, the positions of the spectrophotometer and the trigger sensor are aligned. Nevertheless, this requires a longer adjustment period and thus is not desirable.

Reading apparatus, reading control method, and reading control program


Definitions are received for allowable activity windows and epochs. Each epoch specifies a retention duration and allowable activity window. There can be a retention policy specifying that copies created during a particular time period of the allowable activity window are to be retained past a retention duration of an initial epoch. A determination is made as to whether a copy was created during the particular time period specified in the retention policy. If the copy was not created during the particular time period, the retention duration of the initial epoch is added to a creation time of the copy to obtain a date after which the copy should be deleted. If the copy was created during the particular time period, a retention duration of a subsequent epoch is added to the creation time to obtain the date. The date is then associated with the copy.

Organizations including companies, businesses, institutions, and the like collect and generate a vast amount of data. The data may include documents, reports, video, music, social media postings, emails, medical records, customer transactions, financial records, and so forth.
Since data plays such a vital role in the functioning of an organization, it is important that there be copies of data such as backup copies in the event of a disaster. In addition to backup copies, organizations often make copies for other purposes such as for analytics, reporting, and testing.
An organization may wish to maintain the data including copies of the data for a certain period of time after their creation. In some cases, a retention period is mandated by law. The copies, if left unchecked, however, can cause an organization's storage costs to spiral out-of-control. Different copies may have varying degrees of importance and the importance can change with the passage of time. There is a need for improved systems and techniques that reflect these understandings when calculating final data retention dates in order to more efficiently manage data growth.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions. EMC, Data Domain, Data Domain Restorer, and Data Domain Boost are trademarks of EMC Corporation.

Systems and methods for managing copy creation and deletion


A holder is disclosed, wherein the holder is situated on a circuit board and is used for connecting with an electronic component. The holder comprises an upper surface, a lower surface, and an opening. The upper surface comprises a recess used for laying a flat component, wherein the recess comprises at least one rough area; the lower surface comprises a protruding edge, wherein the protruding edge is connected with the circuit board with glue, and the protruding side and the circuit board delimit a space; and the opening penetrates the upper surface and the lower surface, whereby the gas generated from heating the glue will accumulate in the enclosed space, and the gas will then escape through the opening and out through at least one of the rough areas.

1. Field of the Invention
The present invention relates to a type of a holder and a photographic device, especially to a type of the holder and the photographic device which has gas escape and glue reinforcement designs.
2. Description of the Related Art
In the manufacturing process of the Chip On Board (COB), a holder is often situated on the PCB, and an electronic component can be situated on the holder. Black glue is usually used as an adhesive for the PCB and the holder, but this has the following disadvantages:
1. When the black glue is heated, gas is generated and accumulates in the holder. This will result in unevenness in the holder and will cause the holder to tilt on the PCB. This may also cause the holder to be easily detached from the PCB;
2. Even if the holder is not detached from the PCB, the holder being tilted on the PCB will affect the accuracy of the Modulation Transfer Function (MTF), further influencing the product yield rate; and
3. The surface area in contact between the holder and the PCB is minimal, resulting in insufficient adhesion of the black glue. When the holder and PCB are knocked or shaken, the holder is easily detached from the PCB.
To overcome the disadvantages of the accumulated gas in the related arts, gas escape holes were designed in the holders (as disclosed by Taiwan Patent No. 388554 or No. I240300). With these designs, gas can escape from inside the holder. However, this type of design also allows dust particles to settle inside the holder. This will increase the difficulty of the module formation for the holder design, thus affecting the production line yield rate. The expenses of the holder module design and product cost will also increase.
Therefore, it is necessary to provide a type of holder and photographic device which will eliminate problems encountered by prior technologies.


Cmpositions for coatings having a dry content higher than 80%, preferably of about 85-90% by weight, based on polyisocyanates and PFPEs, completely crosslinkable also in a range of temperatures between 5xc2x0 C. and 20xc2x0 C., comprising the following components:

The present invention relates to high dry content polyurethane compositions based on perfluoropolyether oligomers. Said compositions are used for application to various substrata, such as for example metals, ceramic and stony materials, plastic and glass surfaces and they are able to completely crosslink also at temperatures lower than 20xc2x0 C., also of about 10xc2x0 C., forming thin films having good mechanical and surface properties.
Coatings obtained from polyurethane formulations based on perfluoropolyethers (PFPE) are known in the prior art. According to EP 665,253 it is possible to prepare high dry content polyurethane resins, by crosslinking PFPEs having hydroxyl terminations and functionality comprised between 2 and 4, or mixtures thereof, with polyisocyanic adducts obtained by reaction of polyols with diisocyanates, of the type for example TMP-IPDI (trimethylolpropane-isophorondiisocyanate) having a ratio by moles 1/3). Said formulations have the drawback not to completely crosslink at a temperature of 25xc2x0 C. or lower. Therefore the properties of the obtained coating are unsatisfactory as regards the chemical resistance, permeability and duration in the time.
From EP 812,891 bicomponent xe2x80x9cno dirt pick upxe2x80x9d formulations are known in which the PFPE resin diol is crosslinkable with prepolymers obtained by prepolymerization of a PFPE diol with polyisocyanates obtained by cyclotrimerization of HDI, IPDI or other monomeric diisocyanates, alone or in admixture therewith. The examples of this application describe formulations having a dry content higher than 70% by weight but not higher than 85% by weight. The xe2x80x9cno dirt pick upxe2x80x9d properties are good but it is desirable to further improve them. In conclusion, the protective coatings obtainable by crosslinking the prior art formulations, containing PFPEs having hydroxyl terminations, with polyisocyanates, have a lower crosslinking temperature limit, generally from +25xc2x0 C., which compromises the possibility of application and complete crosslinking in the field and they do not show an optimal combination of properties as indicated hereinafter.
The need was therefore felt to have available PFPE-based polyurethane compositions combining the following properties:
applicability to dry contents greater than 80% by weight, preferably in the range 85-90% by weight,
filming capability and complete crosslinkability also at temperatures in the range 5xc2x0 C.-20xc2x0 C.,
as regards the properties of the coatings obtainable by said formulations:
improved chemical resistance and stability to UV ageing photooxidation,
improved xe2x80x9cno dirt pick usxe2x80x9d surface properties,
good mechanical properties and in particular good surface hardness (pencil hardnessxe2x89xa7B) and abrasion resistance.
Compositions based on polyisocyanates and perfluoropolyethers meeting the combination of the above mentioned properties have now been surprisingly and unexpectedly found by the Applicant.
An object of the present invention are compositions for coatings having a dry content higher than 80%, preferably of about 85-90% by weight, based on polyisocyanates and PFPE, completely crosslinkable also in a range of temperatures between 5xc2x0 C. and 20xc2x0 C., said compositions comprising the following components:
Component 1): mixture comprising:
1.a) Partially fluorinated prepolymers, having free NCO groups, obtained by reaction of (per)fluoropolyethers (PFPEs) diols having number average molecular weight Mn in the range 800-1,500, preferably 1,000-1,200, with the cyclic trimer of the isophorondiisocyanate (IPDI), in said reaction the ratio in equivalents between the OH/NCO groups being in the range 0.20-0.25,
1.b) non cyclic isocyanic trimer of hexamethylendiisocyanate (biuret of HDI) having an absolute viscosity at 20xc2x0 C. lower than 5,000 mPa.s, in component 1) the ratio referred to the dry product between the compound 1.b) and the compound 1.a) being in the range 10-90, preferably 30-60 parts of compound 1.b)/100 parts of compound 1.a);
Component 2): (per) fluoropolyether (PFPE) diol having Mn in the range 350-700, preferably 500-0650, the amount of PFPE diol component 2) being such that the ratio in equivalents between the OH and NCO groups in the composition is in the range 0.9-1.1;
Component 3): inert organic solvent under the crosslinking conditions, complement to 100% by weight of the composition.
The component 1.a) is obtainable by hot dissolving (for example 40xc2x0-80xc2x0 C.) the trimer of IPDI and the (per)fluoropolyether diol in a solvent as those indicated in component 3), maintaining the stoichiometric ratio in equivalents OH/NCO within the indicated limits and a dry content in the range 65%-85% by weight. Then the polymerization catalyst is added, see later on, preferably dibutyltin-bis-isooctylthioacetate and the reaction is hot maintained until the theoretic NCO content is obtained, determined by titration according to ASTM D 2572.
As component 2 also (2a) mixtures of PFPE oligomer diols having Mn in the range 800-1,500, preferably 1,000-1,200, with PFPE oligomer diols having Mn in the range 350-700, preferably 500-650, can be used, in said mixtures of oligomers the weight ratio between, respectively, the high and low molecular weight oligomers being in the range 1/2-1/10, or alternatively the number average molecular weight of the mixtures of PFPE oligomer diols being lower than or equal to 700.
The inert solvent component 3) under crosslinking conditions is a solvent which does not react with the OH and NCO groups present in the composition of the invention.
As component 3) an aprotic dipolar solvent such as ethyl or butyl acetate is preferably used.
As cyclic trimer of isophorondiisocyanate (IPDI) of component 1.a, the commercial product Vestanat(copyright) T1890, Huels can for example be used.
As component 1.b) non cyclic isocyanic trimer of hexamethylendiisocyanate (biuret of HDI), the commercial products Tolonate(copyright) HDB-LV, Rhodia(copyright) or Desmodur(copyright) 3200, Bayer, can be used.
The (per)fluoropolyether diol compounds comprise one or more of the following (per)fluorooxyalkylene units xe2x80x94(C3F6O)xe2x80x94, xe2x80x94(CFYO)xe2x80x94, xe2x80x94(C2F4O)xe2x80x94, xe2x80x94CR4R5CF2CF2Oxe2x80x94,xe2x80x94(CF2)axe2x80x2Oxe2x80x94, wherein Y is F or CF3, R4 and R5 are equal to or different from each other and selected from H, Cl, axe2x80x2 is an integer equal to 3 or 4.
The preferred PFPE diol compounds for the compositions of the present invention are the following, wherein the (per) fluoropolyoxyalkylene units are statistically distributed along the chain:
aI) xe2x80x94(C3F6O)mxe2x80x2 (CFYO)nxe2x80x2xe2x80x94 wherein the (C3F6O) and (CFYO) units are perfluorooxyalkylene units statistically distributed along the chain; mxe2x80x2 and nxe2x80x2 are integers such as to give the above mentioned molecular weights, and mxe2x80x2/nxe2x80x2 are comprised between 5 and 40, nxe2x80x2 being different from 0; Y is F or CF3;
when the unit (CFYO) is absent in this case nxe2x80x2 can also be equal to 0;
bI) xe2x80x94(C2F4O)pxe2x80x2(CYFO) qxe2x80x2xe2x80x94(C3F6O)txe2x80x2xe2x80x94 wherein pxe2x80x2 and qxe2x80x2 are integers such that pxe2x80x2/qxe2x80x2 ranges between 5 and 0.3, preferably between 2.7 and 0.5 and such that the molecular weight is within the above indicated limits; txe2x80x2 is an integer with the meaning of mxe2x80x2, Y=F or CF3; txe2x80x2 can be 0 and qxe2x80x2/(qxe2x80x2+pxe2x80x2+txe2x80x2) is equal to 1/10or lower and the txe2x80x2/pxe2x80x2 ratio ranges from 0.2 to 6;
cI) xe2x80x94CR4R5CF2CF2Oxe2x80x94 wherein R4 and R5 are equal to or different from each other and selected from H, Cl, the molecular weight such as to be comprised in the above mentioned limits, a fluorine atom of the perfluoromethylene unit can be substituted with H, Cl, or perfluoroalkyl group, having for example from 1 to 4 carbon atoms;
dI) xe2x80x94(CF2)axe2x80x2Oxe2x80x94 wherein axe2x80x2 is an integer equal to 3 or 4. The (per) fluoropolyethers are obtainable by known processes. See U.S. Pat. Nos. 3,665,041, 3,242,218, 3,715,378 and EP 239,123.
The two end groups, equal to or different from each other, of the bifunctional (per)fluoropolyethers are of the type
HO (CH2CH2O)x0CH2xe2x80x94CF2xe2x80x94
wherein x0 is an integer from 0 to 4, preferably from 0 to 2; in the preferred compounds x0=0; said end group being linked to the (per)fluorooxyalkylene unit by an oxygen atom but not by peroxidic sequences xe2x80x94Oxe2x80x94Oxe2x80x94.
The formulations according to the present invention advantageously combine the following properties:
complete crosslinkability at temperatures in the range +5xc2x0 C.-+20xc2x0 C.;
very high dry content when applied, also higher than 85%; therefore the formulations of the present invention are able to meet the most restrictive rules in terms of VOC (volatile organic compound) emissions and therefore they can be applied also in crowded urban places;
improved properties of xe2x80x9cno dirt pick upxe2x80x9d, waterproofing, chemical resistance and abrasion-resistance;
high surface hardness (pencil hardnessxe2x89xa7B);
high gloss and transparency;
good mechanical properties such as for example high hardness and flexibility.
It has been surprisingly found that the biuret of HDI component 1.b) as above defined, at the indicated crosslinking temperatures forms homogeneous mixtures both with the partially fluorinated prepolymers having free NCO groups component 1.a) and with the PFPEs diols component 2) as above defined. Other commercial crosslinking agents as the isocyanurate trimers, have not this property, as described in the comparative Examples.
Furthermore, the number average molecular weight of component 2) comprised in the above indicated limits allows to obtain an almost instantaneous homogeneous mixture with the free polyisocyanates of component 1.b) (not prepolymerized).
The compatibility among said components makes it possible the preparation of formulations having a high titre of dry product and reduced viscosity as requird for the application in the field.
The use of PFPE diol mixtures component 2), having bimodal distributions of the molecular weight allows to further improve the above indicated properties and in particular the xe2x80x9cno dirt pick upxe2x80x9d properties.
The compositions according to the present invention can be formulated both as monocomponent and as bicomponent, therefore they can be obtained by mixing the components 1.a), 1.b) and 2) with the solvent, or the same components are suitably combined to give the bicomponent formulation A (components 1.a+1.b) and B (component 2), the solvent being added in A and/or in B.
The obtained formulations are limpid and macroscopically transparent.
The compositions of the invention are crosslinked by addition of a catalyst (only at the time of the use). The chemical classes of catalysts are well known, the metal or amine ones commonly used in the paint formulations can be mentioned, for example: tertiary amines such as triethylendiamine, N-ethyl-ethylendiamine, tetramethylguanidine, dimethyl cyclohexylamine, diazobicyclo octane, etc.; organometal catalysts such as dibutyltindilaurate, tin octanoate, cobalt naphthenate, vanadium acetylacetonate, dimethyl-tin-diethylhexanoate, dibutyltin diacetate, dibutyltin dichlodride, and mixtures thereof. The catalyst is added in concentrations generally ranging from 0.1 to 2% by weight and preferably from 0.5 to 1%.
To the formulations of the invention additives such as for example pigments and fillers, preferably dispersed or predispersed in component 2), can be added. When silica having an opacifying action of the coating are used, they must be incorporated in a minimum amount in order to avoid worsenings (brittleness) of the mechanical properties. Pigments can be selected from the natural, synthetic inorganic and organic ones. As an example of inorganic pigments it can be mentioned: metal oxides (titaniun dioxide, iron oxides, mixed oxides of Ni, Co, Zn, Ti, or Cr, Cu or Fe, Ni, Cr, Mn, cobalt aluminates); organic pigments (derivatives from anthraquinone, quinacridone, tetrachloroisoindolinone, diketoperylene, phthalocyanines, etc.). Fillers as well as inert pigments and any other type of additive, are added to the dispersion under a very fine size, generally with sizes lower than 100 microns, preferably lower than 10 xcexcm, in amounts up to 15% by volume. Other examples of compounds usable as fillers are: polyamides having 20-100 microns sizes, glass spheres such as zeolites, etc.
Other optional additives are thixotropic agents, polymer dispersing agents acrylic, silicone, polyurethane, polyamine or having a carboxylic or non ionic functionality; stretching, anticissing, antifoam additives, etc.; additives to reduce photooxidation (UV adsorber for example hydroxybenzophenone derivatives, hydroxybenzotriazole, etc.) and HALS (hindered amines, for example derivatives from tetramethyl-piperidine, etc.).
The pot life, defined as the necessary time to double the initial viscosity of the formulation, for monocomponent formulations maintains high both at 20xc2x0 C. and at 50xc2x0 C., in a closed vessel in absence of the crosslinking catalyst. The pot life is generally of at least 4 hours at 50xc2x0 C. and at least 8 hours at 20xc2x0 C.
By adding to the formulation small amounts (10-50 ppm) of a suppressor of the catalyst used for the synthesis of the prepolymer component 1.a), for example benzoyl chloride, phosphoric acid or Irganox(copyright) MD, the shelf life of the monocomponent formulation is of various days at room temperature.
The application tachniques are the conventional ones for protective coatings, such as for example spray-gun, brush, roll. In the preferred application technique by spray-gun the suitable viscosities for the formulations are in the range 100-500 mPa.s.
Besides in the case of monocomponent formulations the viscosity values at 50xc2x0 C. are sufficiently low also with the highest dry product contents, therefore allowing a correct application using the above indicated techniques.
The formulation pot-life is of about 10 minutes from the time of the addition of the crosslinking catalyst and therefore when said formulations are spray applied, it is preferable to use guns equipped with a system of mixing heads, optionally heatable, heads known in the prior art and commercially available, wherein the addition of the catalyst at the gun head at the spray-time, with optional recycle of the not sprayed formulation, is involved.
The coatings obtainable by crosslinking at room temperature of the formulations according to the present invention are homogeneous and transparent films, having a 5-100 microns, preferably 30-50 microns, thickness.
The following Examples describe the invention with non limitative purposes.

Compositions for coatings based on (per) fluoropolyethers

Abstract: Component 1): mixture comprising:

Abstract: 1.a) Partially fluorinated prepolymers, having free NCO groups, obtained by reaction of (per)fluoropolyethers (PFPEs) diols having number average molecular weight Mn in the range 800-1,300 with the cyclic trimer of the isophorondiisocyanate,

Abstract: 1.b) non cyclic isocyanic trimer of hexamethylendiisocyanate,

Abstract: Component 2): (per) fluoropolyether (PFPE) diol with Mn in the range 350-700, preferably 500-650,

Abstract: component 3): inert organic solvent in crosslinking conditions, complement to 100% by weight of the composition.


The sheet finisher includes a predetermined folding mode for receiving a sheet from a copy machine and which features a plurality of transfer guides through which the sheets received from the copy machine are selectively transferred; switching flappers for switching the flow of the sheet between guides, a temporary holding guide in which the leading end portion of the sheets can be temporarily inserted; a sheet folding arrangement including press roller pairs for folding the sheets; a sheet discharge angle control device which varies the angle at which the sheets are discharged onto an upper tray in accordance with the folding mode that is being used; a tray shift mechanism for moving the tray left and right so as to stack the sheets which are discharged thereonto in a classifying manner; a friction roller for moving a predetermined corner of each of the sheets into a preselected corner of the tray; a fastening device for fastening the sheets which have been maneuvered into the preselected corner by the friction roller; a tray rise mechanism for changing the distance between the upper surface of the tray and the level at which the sheets are discharged; an escape mechanism which drops processed stacks of sheets from the upper tray into a lower one; and a tray angle varying mechanism for changing the angle of the lower tray when the stacks are dropped theretowards.

1. Field of the Invention
The present invention relates to a sheet finisher which can appropriately fold, sort, fasten and collect sheets which have come out of a copy machine and the like.
2. Description of the Prior Art
Japanese Patent Application Laid-Open No. 61-211272 (1986) discloses a previously proposed sheet finishing device.
This device is arranged to take the sheets which have come out of a copy machine, fold the same and then eject them onto an upper tray. Following this, the sheets on the upper tray are induced to engage a stopper and become aligned. They are then fastened together by stapling. After this fastening operation, the stopper is rotated and the fastened stack of sheets is collected by being dropped onto a lower tray. In this device the lower tray is arranged at a predetermined inclined or slanted angle.
However, with this prior art arrangement, as the stacks of sheets which are fastened together are induced to drop onto the lower tray under the influence of the stopper rotation only, the assuredness with which the sheets are unfailingly dropped into the intended position is low. That is to say, if the upper tray is formed of normal types of plastic, the effect of friction and static electrical charges hinders the sliding of the sheets.
In order to overcome the effect of the friction and static electricity, if the angle of the upper tray is overly increased, the capacity of the tray is undesirably reduced.
Further, if lower tray angle is fixed the capacity of the same is limited.
In particular, if a Z folding mode is selected, the folds of the Z folded sheet cause the thickness of the stack to become three times greater than normal. Depending on the number of stacks accumulated on the lower tray, the entry angle which is defined by a vertical line and the lower tray, rapidly becomes reduced.
Under these conditions, in the worst case, as the stack of sheets is dropped, the leading edge of the stack strikes against those already received in the tray and results in spillage.
Normally, with the so called Z sheet folding function, the sheets which are required to be folded in the folding device, are half folded and the half folded sheets are then again folded in half.
A prior art device which features this Z folding function is disclosed in Japanese Patent Application Laid-Open No. 61-217476 (1986).
In this arrangement a sheet folding transfer chute and a sheet transit chute having a pair of discharge rollers are provided at the downstream of an entrance deflector which is switched in accordance with the presence or absence of the demand for folding.
A first deflector is interposed at the downstream end of this sheet folding transfer chute, and first and second folding rollers which constitute a pair of folding rollers of a first folding stage and a folding position control guide chute are also provided.
Further, a second deflector is interposed downstream of the folding rollers of the first folding stage and second and third folding rollers which constitute a second folding stage roller pair and a second folding position control guide chute are provided.
Additionally, a third deflector is interposed downstream of the second folding stage roller pair, and third and fourth folding rollers which constitute a third folding stage roller pair and a third folding position control guide chute are provided.
Downstream of the roller pair of the third folding stage, a final guide chute is provided which merges with the above mentioned transit chute at its end.
A discharge roller is provided at the downstream of the final guide chute and the transit chute and arranged to discharge the treated sheets through an ejection opening onto a tray.
However, with this type of folding device when forming the folds in the sheets, as the sheet folding position control guide chute which receives the leading end of the sheet subjects the sheet to a degree of resistance, the bowing of the central portion of the sheet which is pinched by the folding rollers is reduced, and in addition to this during the half and Z folding modes, for example, depending on the size of the sheet, first to third sets of folding rollers are necessary in addition to the sheet folding position control guide chute. Accordingly, the construction of the finisher becomes complex, expensive and cannot be rendered compact.
Further, as the discharge rollers and the tray are fixed in place, it is not possible for example, to continuously Z fold a large number of sheets. That is to say, as the thickness of the folded and unfolded ends of the Z folded sheets is notably different, as the number of sheets increases the upper surface of the stacked sheets rapidly becomes inclined with respect to the surface of the tray.
Under these conditions the accumulative capacity of the device is lowered and the manner in which the sheets are discharged and pushed out onto the tray deteriorates the stacking neatness.
Further, the sheet folding mechanism is required to include a half folding mode which folds the sheets in half, a Z folding mode which folds the sheets and then folds the folded section again, in addition to a non-folding mode.
With this above mentioned prior art arrangement irrespective of the sheet folding mode the sheet which have been processed are discharged at a predetermined height above the tray. As the thickness of the folded sheets is two to three times that of the non-folded ones, in order to increase the accumulative capacity, it has been proposed to increase the distance between the top of the tray and the sheet discharge means.
However, this measure leads to the problem that, particularly during the non folding mode, the mass per unit area of the sheet is relatively small and the neatness with which the sheets are stacked is reduced. That is to say, the layer of air between the sheet being discharged and the surface onto which the sheet is intended to drop, produces a floating effect which deteriorates the neatness with which the sheets pile one on the other.
Normally, sheet finishers are provided with a fastening device which staples the collected stack of sheets together. While this appears to be desirable at first glance, before the sheets can be appropriately stapled they must have their side and top edges aligned.
In order to achieve this alignment or setting, one prior proposed arrangement has provided the tray with two side edges and base section and has utilizes the weight of the sheet in combination therewith to define means for suitably aligning the sheets in a suitably neat manner.
An alternative arrangement has provided one fixed side edge, a base and has added an adjustable guide which pushed sideways toward the single fixed edge in order to improve the neatness of the sheet stack.
However, the former arrangement is such that as the width of the guide is fixed, and cannot be reduced to exactly that of the sheets in order to permit the same to received without incident, the desired effect has not been achieved. With the latter arrangement in order to adjust the width of the guide, a drive mechanism is necessary. This provision increases the bulk of the arrangement undesirably and further does not permit the mixing of different sheet sizes.
In connection with the fastening devices which staple the stack of sheets together, the stapler must be moved to a fastening position for the stapling operation and then back to its home or original position after the stapling is completed. An example of a mechanism for returning the stapler to its original or home position can be found in Japanese Patent Application Laid-Open No. 59-69346 (1984). However, with this type of prior art arrangement the stapler must be moved a relatively large distance from its home position to its fastening one. As a result the layout of the finisher is rendered undesirably wide and prevents the achievement of a desirably compact arrangement.
A further problem comes in that the large distance through which the stapler must be moved requires a finite amount of time and slows the overall operation of the finisher.


A portable screw fastener driving tool is driven electrically from a solid state inverter and intended to be coupled to any selected one in a set of screw fastener engaging members, each demanding a drive enabling tightening of the engaged fastener by parameters (e.g. torque, angle, speed) specific to its size or type. Code elements are provided on the members in a binary code pattern specific for each member. Sensors on the tool read the code pattern on the member connected to the tool and serve it electrically to a decoding unit which transforms the read binary pattern to signals adapted to control the inverter the way the member demands.

This invention relates to a hand held power driven tool and a drive system therefor for tightening threaded fasteners. The tool comprises a portable housing with an electric motor therein connected to drive an output shaft to which any selective one in a set of fastener engaging members is releasably connectable into working position.
Tools of that type have been introduced in the automotive industry for performing continuous repetitive work on assembly lines and include an electronic drive unit of solid state inverter type for each tool adapted to transform a single phase AC power input into three phase AC current to the motor. The frequency and tension of the current are automatically and continuously varied and controlled by the drive unit closely according to the demand of the tightening process performed by the fastener engaging member of the tool. In hitherto used applications, due to the automatic character of the operation the tool and drive unit have been set to tighten just one size or type of fasteners at a time, which means that on for instance an assembly line for engines or car bodies, the operator has been able to tighten fasteners in just a few positions on each object. This means that the operator is restricted to an undesirably monotonous work.
It is an object of the invention to enable use of the tool and drive unit on a whole set of fasteners of different sizes by enabling the drive unit to automatically adapt the parameters of the served electric power to the needs of the actual fastener.
This object is attained by the invention defined in the following claims and hereinafter described with reference to embodiments thereof illustrated in the accompanying drawings.

Power driven tool and drive system therefor


The current disclosure discloses a sampling phase selection method for a data stream, wherein the data stream has a variable data rate in a fixed time period. The method comprises the following steps: generating M section signals with the same time interval during the fixed time period of the data stream, generating N continuous clock phases according to a rising edge of each of the section signals, selecting one of the continuous clock phases corresponding to the different section signals in turn to provide a sampling phase, performing a plurality of samplings on the data stream to generate a flag signal, repeating the selecting and the sampling steps to generate N flag signals corresponding to the different section signals, and selecting a final sampling phase according to the N flag signals corresponding to the different section signals.

1. Technical Field
The current disclosure relates to a method for selecting a sampling phase of a data stream and, in particular, to a method for selecting a sampling phase of a data stream having a variable data rate during a fixed time period.
2. Description of Related Arts
Operations of most electronic devices are driven by a clock signal. Due to rapid developments in technology, the working frequency of the clock signal may be above GHz and the clock signal may have a stable oscillating frequency which is generated by an oscillator.
However, the oscillator has a high Q value which is the allowed energy of the clock signal concentrated on a narrow baseband and the harmonic wave of the baseband. When the energy is concentrated on a high frequency harmonic wave, the radiation produced by Electro-Magnetic Interference (EMI) may be greater than regulation standards made by FCC, JEITA and IEC.
For reducing EMI, a Spread Spectrum (SS) is utilized to modulate the clock signal. The frequency of the SS modulated clock signal may not be fixed at a certain frequency but may be varied within a given frequency range. Therefore, the clock signal may have a lower energy distribution or lower frequency range to reduce the effect of EMI.
FIG. 1A shows a clock signal CLK_ref which is not modulated by SS. As shown in FIG. 1A, the clock signal CLK_ref includes a fixed frequency fc. FIG. 1B shows a frequency spectrum of the clock signal CLK_ref. As shown in FIG. 1B, the energy at frequency fc is above a given threshold energy P0. The given threshold energy P0 is the energy for causing EMI. FIG. 1C shows a diagram of the clock signal CLK_ref and time.
FIG. 2A shows a clock signal CLK_SS which is modulated by SS. FIG. 2B shows a frequency spectrum of the clock signal CLK_SS. As shown in FIG. 2B, the energy of the clock signal CLK_SS has been spread to frequency ranges f1 and f2. Therefore, is energy at frequency fc is under a given threshold energy P0. FIG. 2C shows a diagram of the clock signal CLK_SS and time. Referring to FIG. 2C, the output frequency of the clock signal CLK_SS may periodically work between a range of frequency f1 and f2.
Moreover, a high speed data stream may be modulated by SS and transmitted in order to reduce EMI. When the modulated data stream is transmitted, data jitter and phase skew between the modulated clock signal and the data stream may affect the sampling section of significant bits.
If a conventional oversampling is performed to sample bits of data of the modulated data stream, a certain sampling clock phase may only sample bits of data of a certain frequency band. Moreover, when a high-speed data stream is transmitted via a noise channel, the high-speed data stream may be interfered by a noise signal having a fixed time section.
If a conventional oversampling is performed on the high-speed data stream, the noise signal may be continuously sampled by a certain sample phase. Therefore, the current disclosure provides a method for selecting a sampling phase of a data stream.

Sampling phase selection method for a stream of data bits


A flow detection sensor has a manifold with an inlet on a bottom surface and an outlet on a side surface. A movable partial blockage rests near the bottom surface of the manifold and is movable upward in response to a flow of liquid from the inlet to the outlet. A sensor detects the position of the movable partial blockage within the manifold.

1. Field of the Invention
The present invention relates to the field of sensing the flow of a liquid and more particularly to a highly sensitive liquid flow detector.
2. Description of the Related Art
Liquid flow detectors are often used to detect the flow of water in water heaters. Electrically operated water heaters generally are known in the prior art and have numerous common features. The most common water heater used today is a water heater having a storage tank. In this, a supply or tank of water is pre-heated by an electric heating element or combustion of fossil fuel so that hot water is available shortly after a hot-water spigot is opened. Storage-tank water heaters waste energy in that there is substantial energy lost by radiation and conduction of the hot water stored in their storage tank, sometimes 40 or 50 gallons. The radiated energy also taxes air conditioning systems. Several attempts have been made to reduce this waste, including enhanced insulation for reducing radiated heat lost and using timers to disable the heating elements during night hours.
Recently, tankless, or instantaneous, heaters have been deployed for heating water on demand. There are several major advantages in tankless water heaters. The first is, because there is no pre-heated water, there is very little energy loss due to heat radiated from the pre-heated water. Second, the tankless water heaters are smaller, requiring fewer raw materials and requiring fewer resources in shipment. Third, the tankless water heaters occupy less space in homes, apartments, retail outlets, warehouses etc.
Several U.S. patents cover various aspects of tankless water heaters. U.S. Pat. No. 3,351,739, issued to Eckman has a tankless water heater with staged energization of electrical heating elements and a high temperature cutout switch.
U.S. Pat. No. 3,795,789, issued to Malzoni has a tankless water heater with a flow switch and electric heating elements.
U.S. Pat. No. 4,604,515, issued to Davidson and U.S. Pat. No. 4,638,147, issued to Dytch et al. include a solid state switch to control electrical current to the heating elements. Dytch mounts the solid state switch on a wall of the heating chamber, thereby cooling the switch while recovering generated heat. Dytch also teaches locating a temperature sensor at the outlet of the heater.
U.S. Pat. No. 5,479,558 to White, Jr., et al describes a flow-through tankless water heater with a flow switch. The flow switch has an arm and a ball joint, but requires significant water flow to energize the flow switch.
U.S. Pat. No. 6,552,283 to Cabrera describes a flow-switch. The flow switch has a floating magnetic set of balls that have a specific gravity higher than water yet will float upwardly in a pipe when water flows, thereby coming into proximity with a magnetic switch and energizing the heating elements. The floating set of magnetic balls must be retained within the pipe to prevent them from flowing out of the water heater. Unfortunately, this requires screens within the flow of water which, in many circumstances, corrode or clog during use.
GB 471,730 to Shepherd describes a flow switch for a tankless water heater. The flow switch of this patent has a plunger in a cylinder that, when water flows, is pushed downward, activating a mercury switch to power the heating elements. This switch uses a spring to urge the plunger back into the resting mode, thereby removing power from the heating elements. The use of a spring is problematic, in that the spring can break or corrode, thereby resulting in continuous power to the heating elements.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. What is needed is a liquid flow detector that detects a small amount of liquid flow and has limited components that are exposed to the liquid, reducing failure due to corrosion and clogging.


The invention relates to an inspection system for process equipment for treating substrates, such as, for instance, semiconductor wafers or flat panel displays. The system is provided with a wireless sensor with which the interior of the process device can be inspected. The sensor is provided with a transmitter to transfer a signal, during inspection of the interior of the process device, to a receiver disposed outside the process device. The wireless sensor is arranged on a support having substantially the same dimensions as the substrates to be treated.

This invention relates to an inspection system for process equipment for treating substrates, such as, for instance, semiconductor wafers or flat panel displays.
During the performance of a process treatment on substrates such as semiconductor wafers or flat panel displays, a strict control of the process parameters is required. Therefore process treatment typically takes place in a process chamber which is closed to the surroundings. Such a process chamber can be a vacuum chamber. To ensure a controlled process, the process chamber is provided with fixedly arranged sensors, for instance for measuring the temperature and the pressure. These sensors can be arranged in the chamber itself but it is also possible that the sensors are arranged outside the chamber and measure via a window provided in the wall of the chamber. When sensors are fixedly arranged in the process chamber, the sensors must be resistant to the process conditions used. This imposes a limitation on what sensors can be used for this purpose. The arrangement of sensors outside the process chamber and measuring through a window likewise imposes limitations on what sensors can be used and what quantities can be measured with them. In some processes, such as those where a thin layer is deposited on the substrates, the equipment is subject to fouling and regular servicing is required. It is then important that such maintenance be performed at the right time: not too soon, which would lead to unnecessarily high costs and to reduced availability of the equipment, nor too late, which would lead to poor process results and product rejection. The possibility of visually inspecting the interior of the process chamber would lead to a better determination of the moment of maintenance. A camera permanently arranged in the process chamber is naturally subject to the same fouling as the process chamber itself and the question is if a proper observation could be made with it. In addition, the question is if such a camera would survive the process conditions of elevated temperature, reactive gases, vacuum and the like. Also, in special circumstances, there may be a need to measure parameters in the process chamber such as temperature, pressure, gas concentration, ionization degree of the gas, and the like, this in addition to, or for comparison with, the information supplied by the fixedly arranged sensors. Normally, it is not possible to perform such additional measurements without making the process chamber accessible for inspection through disassembly. Another need for an inspection possibility occurs in programming the substrate transport mechanism which transports the substrates in such process equipment from an input station to the process chamber and back again. The substrate must then be accurately deposited in the correct position in the process chamber. During programming, visual control is a requirement. This means that the programming of the substrate transport mechanism must take place with the chamber disassembled. As an alternative, the visual control can take place through the window. The question is, however, how accurately a visual control can be done through a window, in view of light diffraction.
The object of the present invention is to provide a solution to the above problems and to provide an inspection system with which at any time the interior of the process chamber can be inspected, or with which measurements in the interior of the process chamber can be carried out without the necessity of dismounting the process chamber.
This object is achieved in that the inspection system comprises a sensor which is provided with a transmitter for wireless communication and a receiver disposed outside the process device, while the sensor provided with a transmitter is arranged on a support having substantially the same shape and dimensions as the substrates to be treated.
When the process device is provided with a transport mechanism for transporting the substrates, the support with the wireless sensor arranged thereon can be transported from outside the process chamber to the interior of the process chamber and vice versa in the same manner as the substrates to be treated.
The invention also relates to a sensor provided with a transmitter for wireless communication, for inspecting the interior of a process device for treating substrates, the sensor being arranged on a support having substantially the same shape and dimensions as the substrates to be treated. Such a sensor can be applied fruitfully in an inspection system according to the invention.
The invention further relates to a method for inspecting the interior of a process device for treating substrates, wherein the process device is provided with an input/output station for the input/output of substrates, at least one process chamber for treating substrates and substrate transport means for transporting the substrates from the input/output station to the process chamber and vice versa, wherein a sensor provided with a transmitter is placed on the input/output station and is transported with the substrate transport means to the interior of the process device for performing the inspection, wherein during the inspection the transmitter transmits a signal which can be received with a receiver disposed outside the process device, and wherein after completion of the inspection the sensor is placed on the input/output station again with the substrate transport means.
With such a method, the interior of a process chamber of the process equipment can be inspected in a highly efficient manner. Moreover, the operation of the substrate transport means can be inspected during use without the housing or the like needing to be removed.
According to a further elaboration of the invention, the method is characterized in that programming of the substrate transport mechanism takes place during the visual inspection, on the ground of the information supplied by the camera. Further, according to a further elaboration of the method according to the invention, adjustment of the process device can take place during inspection, on the ground of the information supplied by the sensor.
In a process device for machined treatment of substrates, the substrates are supplied while placed in cassettes. According to the invention, on such a substrate, a wireless sensor is fitted. Instead of a standard substrate, also a special sensor support can be used, such that the external dimensions are substantially equal to those of a standard substrate, so that the sensor support can be carried to the process chamber by the substrate transport mechanism and that the sensor support fits in a substrate position in the process chamber. For the sensor support, instead of the usual substrate material, a different material can be chosen, for instance aluminum, or another metal or an alloy or glass. On the upper side of the support, the sensor can be provided. An example of such a sensor is the video telemetry capsule endoscope as described in Gavriel Iddan et al. in Nature, Vol. 405, May 2000, p. 417. This camera capsule has no external connections by means of wires, glass fiber cables or other physical connections. The dimensions are 11xc3x9730 mm. The capsule is provided with a battery and a transmitter which transmits in the UHF range. The UHF signal is received by one or more antennas connected with a receiver. The receiver can be connected with a storage system for storing the received images or with a Video imaging system for reproducing the images or with a computer. A telemetric system for the wireless transfer of the signal utilizes, according to the prior art, a pulse code modulation (PCM) method. The above-described camera capsule is used for inspecting the stomach wall of a patient. To that end, the patient swallows the capsule and the UHF signal transmitted by the capsule is received with antennas fitted on the body. In due course, the capsule leaves the body by the usual route via the gastrointestinal tract. In this way, such an inspection can be carried out without requiring surgical intervention.
When such a sensor fitted on a support is used in the interior of a process device, the antenna can be disposed outside the process device. Depending on the thickness and nature of the material of the walls of the process device, however, it may be necessary for a proper reception to dispose the antenna in the interior of the process device, while the signal is brought outside by means of a signal line and a lead-through.
For the wireless transfer of the signal, instead of the more conventional radio techniques, the world standard xe2x80x9cBluetoothxe2x80x9d technology can be utilized. The Bluetooth technology utilizes a radio signal in the frequency band of 2.4 to 2.48 GHz, applies a spread spectrum, frequency jumping and a complete duplex signal with 1600 frequency jumps per second. The signal jumps between 79 frequencies located at a mutual interval distance of 1 MHz to achieve a high degree of interference immunity. This technology is especially suitable for signal transfer over a short distance, 10 m, and is optionally suitable for signal transfer over a medium-range distance, 100 m. An example of an application is given in U.S. Pat. No. 6,069,588 in the name of O""Neill. The advantage of a transmission system according to the Bluetooth technology is that the chips required therefor are particularly compact and energetically economic. Moreover, since this technique focuses on consumer applications, the costs of these chips will be low.
As a further alternative to wireless transfer, use can also be made of infrared signal techniques, for instance according to the standard IrDA, known to those skilled in the art. The disadvantage of infrared techniques, however, is that a line of sight is necessary, penetrable for infrared light.
In addition to the example of a camera mentioned, many other sensors are conceivable. For instance sensors for temperature, pressure, concentration of gas, ionization degree of a gas, acceleration and other quantities. The use of the same technique for manufacturing sensors as for manufacturing integrated electronic circuits leads to the situation that many compact and energetically economical sensors are available and are becoming available. These sensors are in particular suitable for use according to the invention.
What has been contemplated for the application of the invention is, in particular, process equipment for treating silicon wafers. Such wafers are costly and a proper control of the process equipment is of eminent importance. This applies in particular to wafers having a large diameter, for instance 200 mm, or the largest wafer currently in use, 300 mm. The sensor can be provided on a wafer, together with a transmitter and an energy supply. The energy supply can consist of a battery. To be considered as an alternative is a solar cell, in which case the process device must provide for irradiation with light. When the substrate is a silicon wafer, the sensor and/or the transmitter can also be provided in, instead of on, the wafer, by means of the technique for manufacturing electronic circuits.
It is noted that U.S. Pat. No. 4,543,576 discloses a wireless measuring system which, in a vapor deposition system, during vapor deposition, measures the temperature and resistance of the vapor deposited layer on a reference substrate, while outside the vapor deposition chamber a receiver is disposed. In this vapor deposition system, the measuring system is mounted on a movable substrate holder which during vapor deposition is moved to improve the uniformity of the vapor deposited layer. However, the measuring system described in this U.S. patent specification is large compared with the substrate and is connected with the position of the reference wafer. In the above U.S. patent specification, it is not described that the substrate itself can serve as a support of the sensor, so that the substrate provided with a sensor can be transported with the substrate transport mechanism through the process device to any substrate position in the system. Moreover, in this known apparatus, it is not the process equipment itself that is inspected, but the layer which is formed with this equipment.

Inspection system for process devices for treating substrates, sensor intended for such inspection system, and method for inspecting process devices


In a plasma processing apparatus according to the present invention, a gas inlet port and a discharge port are provided on a chamber for introducing and discharging gas into and from the chamber respectively. A sample to be etched is placed on an electrode part, so that a high-frequency power source applies a high-frequency bias to the sample. An electromagnet provided on the periphery of a plasma generation area generates a magnetic field while a waveguide connected to an upper potion of the chamber introduces a microwave into the plasma generation area through a microwave introduction window. Electron cyclotron resonance is excited for the gas for generating plasma. At least a surface of the microwave introduction window exposed to the plasma generation area is made of quartz, while the gas contains fluorine. The apparatus having the aforementioned structure can remove a material adhering to the surface of the microwave introduction window when the sample is etched.

1. Field of the Invention
The present invention relates to a technique of etching gold, platinum, iridium or a conductive metal oxide with plasma, and more particularly, it relates to a technique of cleaning a plasma etching apparatus introducing a microwave for generating plasma.
2. Description of the Prior Art
In a high-frequency device or a ferroelectric memory applied to a mobile communicator such as a portable telephone, for example, a metal such as gold, platinum or iridium is employed as the material for a wire or an electrode in an LSI. In an element employing a substrate of gallium arsenide as a high-frequency device, for example, gold is employed as the material for a gate electrode or the like due to requirement for the characteristics of the element. In a ferroelectric memory employing a metal oxide for a dielectric, oxidation resistance is required for an electrode material and gold, platinum or iridium having small reactivity is employed for the electrode material not to reduce the dielectric.
While an RIE (reactive ion etching) apparatus or the like is employed for patterning the metal, an etching apparatus such as an ECR (electron cyclotron resonance) plasma apparatus or a surface wave plasma etching apparatus employing high-density plasma is now being employed following refinement of devices.
Dissimilarly to silicon or aluminum, however, the aforementioned metal has small reactivity with plasma. When subjected to plasma processing, therefore, the metal is scattered from the processed material mainly by sputtering, to adhere to the inner part of a chamber of the plasma apparatus.
The material adhering to the inner part of the chamber in the aforementioned manner is conductive. In a plasma etching apparatus generating plasma with an electrode, generation of the plasma is not remarkably influenced by such a conductive material adhering to the electrode. In a plasma etching apparatus generating plasma by introducing a microwave, however, a conductive material adhering to a window for introducing the microwave reflects the microwave, to cause difficulty in generation of the plasma.
While the aforementioned metal partially reacts with chlorine or fluorine, a chloride or a fluoride of the aforementioned metal has low vapor pressure. Under ordinary pressure, for example, AuF3 is sublimed at about 300xc2x0 C., PtF6 is vaporized at 69xc2x0 C., IrF3 is decomposed at 250xc2x0 C., and InF3 is vaporized at a temperature of at least 1200xc2x0 C. Despite plasma processing, therefore, the reactant is hardly discharged as vapor but adheres to the inner part of the chamber, and this conductive reactant disadvantageously causes the aforementioned difficulty in generation of the plasma. When chlorine is employed as etching gas, further, this etching gas may corrode and damage a metal film or an insulator film of an aluminum alloy such as Al or AlSiCu or a high dielectric constant metal oxide such as SBT (strontium bismuth tantalate) or BST (barium strontium titanate), for example, separately formed on a substrate formed with the metal to be etched. Therefore, employment of chlorine is unpreferable.
While the electrode material to be etched may be prepared from a conductive oxide such as tin oxide, ruthenium oxide or iridium oxide or an oxide such as indium oxide or tantalum oxide attaining conductivity due to addition of an impurity in place of the aforementioned metal, this material also adheres to the inner part of the chamber, particularly the microwave introduction window, as a result of sputtering to cause the aforementioned problem.
An object of the present invention is to reduce inhibition of generation of plasma caused by a deposit in a technique of introducing a microwave through a microwave introduction window for generating plasma and performing etching on the basis of this plasma.
In order to attain the aforementioned object, a plasma processing method according to an aspect of the present invention introduces a microwave and gas into a chamber capable of storing a sample having a conductive layer through a microwave introduction mechanism and from a gas inlet port respectively for processing the conductive layer with plasma, while at least a part of the microwave introduction mechanism exposed to the plasma consists of quartz, the gas contains at least fluorine, and the part of quartz is etched at the same time during the processing.
In an example of this plasma processing method, the gas contains no halogen element but fluorine.
A plasma processing method according to another aspect of the present invention introduces a microwave and gas into a chamber capable of storing a sample having a conductive layer through a microwave introduction mechanism and from a gas inlet port respectively for processing the conductive layer with first plasma, while the sample is discharged and a part of the microwave introduction mechanism exposed to the first plasma is cleaned with second plasma when prescribed information changed by processing the conductive layer with the first plasma satisfies a prescribed condition.
According to this plasma processing method, the part of the microwave introduction mechanism exposed to the first plasma, to which a conductive material adheres as a result of processing the conductive layer with the first plasma, is cleaned with the second plasma after the sample is discharged, whereby the cleaning can be performed without damaging the material of the sample by the second plasma.
When the number of processed samples, for example, is employed as the prescribed information, the part of the microwave introduction mechanism exposed to the plasma can be prevented from adhesion of a large quantity of conductive material caused by processing an excessive number of samples.
When information reflecting the state of the first plasma, position information of a microwave matcher interposed between a microwave generation source and the chamber or a reflected power value of the microwave, for example, is employed as the prescribed information, the part of the microwave introduction mechanism exposed to the plasma is cleaned by detecting the state of the plasma changed by adhesion of the conductive material, whereby the part of the microwave introduction mechanism exposed to the plasma can be prevented from adhesion of a large quantity of conductive material.
In an example of this plasma processing method, at least the part of the microwave introduction mechanism exposed to the first plasma consists of quartz, and the second plasma is generated from gas containing fluorine.
The conductive layer contains gold, silver, copper, a platinum metal, indium, gallium, germanium, arsenic or phosphorus, an alloy of any of these metals, or a metal oxide.
A plasma processing apparatus according to still another aspect of the present invention comprises a chamber capable of storing a sample having a conductive layer to be etched with plasma, a gas inlet port for introducing gas containing fluorine into the chamber, and a microwave introduction mechanism, consisting of quartz at least in a part exposed to the plasma, for introducing a microwave for generating the plasma from the gas into the chamber.
The microwave introduction mechanism preferably has a microwave introduction window of quartz. The microwave introduction window of quartz is provided to fill up a through hole of a conductor member having the through hole, for example.
In an example of this plasma processing apparatus, the microwave introduction mechanism has a microwave introduction window and a separator, consisting of quartz at least in a part exposed to the plasma, for separating the microwave introduction window from the plasma. The microwave introduction window is formed by a conductor member having a through hole, for example.
According to the plasma processing apparatus having the aforementioned structure, the microwave introduced from the microwave introduction mechanism generates plasma from the gas containing fluorine. When the conductive layer or a compound thereof adheres to the part of the microwave introduction mechanism exposed to the plasma due to plasma processing, fluorine contained in the plasma etches this part of the microwave introduction mechanism, thereby preventing deterioration of introduction of the microwave.
A plasma processing apparatus according to a further aspect of the present invention comprises a sample holder, receiving a sample having a conductive layer to be etched with plasma, capable of applying high-frequency power to the sample, a sample holder cover, consisting of quartz at least in a part exposed to the plasma, for covering the periphery of the sample holder without coming into contact with the sample, a chamber capable of storing the sample holder and the sample holder cover, a gas inlet port for introducing gas containing fluorine into the chamber, and a microwave introduction mechanism for introducing a microwave for generating the plasma from the gas into the chamber.
According to the aforementioned structure, the conductive layer or a compound thereof will not adhere to the sample holder as a result of plasma processing. When the conductive layer or a compound thereof adheres to the sample holder cover, fluorine contained in the plasma etches the sample holder cover thereby preventing disturbance of application of the high-frequency power.
The upper end of the sample holder cover is preferably located downward beyond a position of the sample holder for receiving the sample. Thus, the upper end of the sample holder cover will not inhibit the sample from coming into contact with the sample holder, whereby the high-frequency power can be sufficiently applied to the sample.
A plasma processing apparatus according to a further aspect of the present invention comprises a chamber capable of storing a sample having a conductive layer to be etched with plasma, a gas inlet port for introducing gas into the chamber, and a microwave introduction mechanism for introducing a microwave for generating the plasma from the gas into the chamber, while the microwave introduction mechanism includes a waveguide for propagating the microwave, a microwave introduction window having microwave transmissibility interposed between the waveguide and the chamber, and reflection quantity detection means detecting the quantity of reflected microwave, and plasma for cleaning a part of the microwave introduction window exposed to the plasma is generated in the chamber when the quantity of the reflected microwave exceeds a prescribed level.
According to this structure, the quantity of the reflected microwave increased by a conductive material adhering to the microwave introduction window as a result of etching the conductive layer is so detected as to clean the microwave introduction window when the quantity of the reflected microwave is increased, whereby stable plasma processing can be carried out.
A plasma processing apparatus according to a further aspect of the present invention comprises a chamber capable of storing a sample having a conductive layer to be processed with plasma, a gas inlet port for introducing gas into the chamber and a microwave introduction mechanism for introducing a microwave for generating the plasma from the gas into the chamber, while the microwave introduction mechanism includes a waveguide for propagating the microwave, a microwave introduction window having microwave transmissibility interposed between the waveguide and the chamber, and a microwave matcher for matching the microwave with the plasma by controlling the position or the quantity of a member inserted into a part propagating the microwave, and plasma for cleaning a part of the microwave introduction window exposed to the plasma is generated in the chamber when the position or the quantity of the member of the microwave matcher inserted into the part propagating the microwave is out of a prescribed range.
According to this structure, the position or the quantity of insertion of the member of the microwave matcher changed by a conductive material adhering to the part of the microwave introduction window exposed to the plasma as a result of etching the conductive layer is so detected as to clean the microwave introduction window when the position or the quantity is out of the prescribed range, whereby stable plasma processing can be carried out.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

Method and apparatus for plasma processing


The invention provides segments of HSV-1 and HSV-2 glycoprotein B which include antigenic epitopes in the gB amino-proximal region that react with human antibodies in a type-specific manner, and epitopes in the gB carboxy-proximal region that cross-react with HSV-1 and HSV-2 antibodies.

The invention relates to glycoprotein B segments of herpes simplex virus types 1 and 2 (HSV-1, HSV-2) containing linear antigenic epitopes reactive with human antibodies to HSV-1 and HSV-2. Of particular interest are HSV glycoprotein B segments containing type-specific epitopes useful in serodiagnostic immunoassays for distinguishing HSV-1 infection from HSV-2 in humans, and in human vaccines for generating neutralizing antibodies to HSV-1 or HSV-2.
1. Field of Art
The herpes simplex virus (HSV) glycoprotein B (gB) is a transmembrane envelope glycoprotein that contributes to the penetration of virions into host cells by host cell recognition, viral adherence, and virion-cell membrane fusion. gB induces fusion of the virion envelope with the cellular cytoplasmic membrane, an essential function for virus entry. Immunization of humans and animals with purified gB induces virus-neutralizing antibody responses, and recombinant gB proteins are being investigated as HSV vaccines. The amino acid sequences for both gB-1 and gB-2 and their encoding nucleotide sequences are known and available, e.g., from Genebank.
The HSV type 2 gB (gB-2) polypeptide contains 904 amino acids (aa)--(FIG. 5). The amino-terminal segment (1-22aa) is a signal peptide that is cleaved from the mature protein during processing. aa 745 to 798 constitute a hydrophobic transmembrane anchor domain. The segment carboxy-proximal to the anchor domain (aa 799 to 904) is cytoplasmic and appears to mediate membrane fusion. The amino-proximal segment (aa 23 to 744) is extracellular and contains epitopes that are recognized by virus-neutralizing antibodies. HSV type 1 gB (gB-1) is structurally similar (FIG. 4).
HSV-2 and HSV-1 are closely related viruses. Most of their proteins, including gB, are highly conserved (very homologous) and are known to elicit cross-reactive antibody responses. It has accordingly been difficult to provide reliable, sensitive immunoassays capable of distinguishing HSV-1 from HSV-2 infection, or to provide type-specific vaccines effective against HSV infection.
2. Discussion of Related Art
HSV infections in humans are commonly diagnosed by immunoassay of blood samples for HSV antibodies in Western blot assays or other immunoassays using random lysates of cells infected with HSV-1 or HSV-2 as antigen targets. These serodiagnostic assays have been recognized as generally unsatisfactory for distinguishing HSV-1 infection from HSV-2 infection owing to strong responses of type-common antibody-reactive regions of both native proteins. This has proved to be a particular problem in distinguishing acute HSV-2 infection in patients previously infected with HSV-1, because of a likely anamnestic response to HSV-1 and HSV-2 type-common antigens which obscures responses to type-specific antigens. Difficulties in detecting HSV-2 type-specific antibodies by using HSV-2 cell lysate Western blot assays on subjects previously infected with HSV-1, for example, may result in a not uncommon misclassification of samples subjected to these assays as HSV-1 positive and HSV-2 negative. Accordingly, on-going research has attempted to identify domains of various native HSV viral proteins which are highly reactive with anti HSV-1 and anti HSV-2 antibodies and which provide a virus type-specific antibody response.
While several HSV proteins have been considered as sources of useful antigenic epitopes for diagnosis and prevention, only HSV-1 and HSV-2 glycoprotein G (gG-1, gG-2) has been found useful to date for use in assays with improved sensitivities and specificities. Most HSV-2 and HSV-1 proteins are very homologous, as noted above. However, HSV-2 gG-2 and HSV-1 gG-1 have highly dissimilar amino acid sequences, and human gG-2 and gG-1 antibody responses in the presence of HSV-2 and HSV-1 infections appear to have significantly improved virus type-specificity over lysates of infected cells. Thus, detection of antibody reactivities to native or recombinant HSV-1 or HSV-2 glycoprotein G presently forms the basis for current HSV type-specific immunoassays.
HSV glycoprotein B has also sparked interest as a possible source of type-specific HSV antigens. To date, however, only the complete proteins have been used, and these have exhibited only cross-reactive antibody responses. Virus-specific determinates to human antibodies have been eagerly sought for many years, without notable success.
HSV-2 and HSV-1 infections each elicit strong immunoglobulin G (IgG) antibody responses in vivo to both HSV-2 gB-2 and to HSV-1 gB-1 (1, 2, 3); these antibodies are detectable early in acute infections, attain high titers, and persist for many years (4, 2, 5). Cross-reactive polyclonal antibody responses predominate (4, 6, 7). This exhibition of the related antigenicity of HSV gB-2 and gB-1 is consistent with the marked overall conservation of their amino acid sequences (86% at the amino acid level). Perhaps in consequence, the structures of gB-1 and gB-2 have not been previously broadly elucidated with respect to specific antigenic domains recognizing human antibodies which are clinically useful, especially type-specific antigenic regions capable of distinguishing HSV-1 from HSV-2 infection.
While human IgG antibodies cross-reactive to whole or randomly lysed gB-2 and gB-1 are thus known, virus type-specific antibodies have only been reported in murine models. Immunization of laboratory animals with purified virion-derived gB-2 elicits antibodies that neutralize HSV-2 infectivity in vitro and protect susceptible animal hosts from experimental HSV-2 infections (reviewed in Seminars in Pediatric Infections 2: 178-185, Stanberry, 1991 and Microbiol. and Immunol. 179: 137-158, Burke, 1992).
HSV-2 infections and HSV-1 infections elicit strong IgG antibody responses to gB-2 and to gB-1, respectively. gB-2 responses include antibodies that cross-react strongly with native gB-1, and gB-1 responses include antibodies that cross-react strongly with native gB-2. Therefore, gB-2 reactivities and gB-1 reactivities do not differentiate between antibody responses to HSV-2 infections and antibody responses to HSV-1 infections. Immune responses to most HSV-2 proteins include antibodies that cross-react with the homologous HSV-1 protein, and vice versa. Linear epitopes that react with type-specific, virus-neutralizing murine monoclonal antibodies have been localized to the extracellular amino-terminal segment of gB-1 (8, 9, 10, 11, 12, 13, 14). However, little information has been available regarding the locations and type specificities of gB epitopes recognized by human HSV antibodies (8, 15, 14). Vaccines comprising both recombinant gB-2 and gB-2 are currently undergoing clinical trials (16, 17), but efficacy or type-specificity of gB-2 in this application is not yet known.
The above numerals refer to the following publications, all incorporated herein by reference:
1. J. Virol. Methods 18:159-168, 1987 PA0 2. Infect. Immun. 31:1062-1070, 1981 PA0 3. Am. J. Epi 104:192-201, 1976 PA0 4. J. Med. Virol. 17:153-166, 1985 PA0 5. Infect. Immunol. 34:880-887, 1981 PA0 6. J. Med. Virol. 15:251-263, 1985 PA0 7. Rev. Infect. Dis. 2:899-913, 1980 PA0 8. J. Med. Virol. 27:309-316, 1989 PA0 9. J. Gen. Virol. 70:735-741, 1989 PA0 10. Virol. 135:379-394, 1984 PA0 11. Virol. 186:99-112, 1992 PA0 12. Virol. 172:11-24, 1989 PA0 13. J. Infect. Dis. 166:623-627, 1992 PA0 14. J. Infect Dis. 168:844-853, 1993 PA0 15. J. Clin. Micro. 23:725-730, 1986 PA0 16. Rev. Infect. Dis. 13:S906-S911, 1991 PA0 17. Micro. Immunol. 179:137-158, 1992


An elongated flexible heater strip is provided having a transmission line section and a heater section employing a high mu material to control temperature at the Curie temperature of the high mu material; the above elements and a return buss being confined in a conductive sheath having a plurality of transverse slots to render the strap flexible, so that it may be cinched about a member to be heated; a strip of conductive material, such as copper, extending at least along the transmission line section interiorly of said sheath to reduce the resistance thereof and increase the current carrying capacity of the strap.

There is disclosed in U.S. Pat. Nos. 4,695,712 and 4,717,814 a quite thin, strap-like device that is a flexible heater employed to solder braids of electrical conductors or metal junctions to one another. These prior art straps have been sold, by the assignee cf the present invention, under the trademark "SOLDER STRAP" for about five years. The devices are comprised of a centrally located return buss, a high mu material located on one side and insulated from the return buss and an outer sheath. The sheath on the side of the return bus remote from the high mu material is transversely slotted to render the strap flexible, so that it may be wrapped about a pipe or braid.
The heater is usually provided with a latch and is adapted to cooperate with a tool that both cinches the strap and provides a constant current thereto. The heater extends along a length of the strap remote from the end that cooperates with the tool for only a distance necessary to surround the pipe or braid. A length of strap that extends from the tool to the heater region serves as a transmission line and does not include high mu material. This length of sheath is however transversely slotted along its entire length in order to impart flexibility. Also as the strap is cinched during use, the transmission line section folds easily upon itself without kinking, which might internally short out the strap. The currently available straps are limited, in the power that can be delivered to a load, to about 250 watts. Demands have developed for a higher wattage strap, but one in which the physical dimensions remain unchanged, and which operates at the same temperature.
Further, recent developments have indicated a potential need for a strap that operates at much higher temperatures, specifically braze temperatures. The present strap operates at solder temperatures of about 350.degree. C. to 450.degree. C., while braze temperatures are in the 700.degree. C. to 850.degree. C. range.


A crossbow that includes a frame along which a movement trajectory of an arrow substantially passes, a first limb and a second limb connected to the frame on opposite sides from the movement trajectory. Each of said limbs having a loose end. The crossbow further includes a first cam having a first rotation axle and a second cam having a second rotation axle. The cams rotatably arranged on a first holder and on a second holder, respectively. The holders fixed on said frame on opposite sides from the movement trajectory. In addition, the crossbow is provided with a bowstring connecting the first cam and the second cam, a first cable connecting the first cam and the loose end of the first limb, and a second cable connecting the second cam and the loose end of the second limb.

Numerous varieties of crossbows are known in the art that ensure a high initial speed of an arrow. This is achieved by means of using cables, rollers, cams, cam holders, and limbs.
The closest analog to this invention may be a crossbow according to U.S. Pat. No. 9,297,604, wherein the holders with the cams arranged thereon are attached to the stock assembly. The limbs are also attached to the stock assembly. The bowstring connects the cams. The first cable connects the first cam to the first limb and the second limb. The second cable connects the second cam to the second limb and the first limb. When the bowstring is being drawn, each of the cams wraps around the cable track to a cable length that corresponds to movement distance of these two limbs. Therefore, the cable track on the cam should have a great length. It is apparent that this arrangement of the cables compromises arrow's initial speed. Furthermore, the fact that the cables cross the crossbow stock negatively affects said initial speed achieved with this crossbow due to the formation of a friction node. Another shortcoming of this crossbow is a rather great width of the device, which is defined by the arrangement of the limbs on the two sides of the cams.