Methods for forming a magnetic tunnel junction (MTJ) storage element and MTJ storage elements formed are disclosed. The MTJ storage element includes a MTJ stack having a pinned layer stack, a barrier layer and a free layer. An adjusting layer is formed on the free layer, such that the free layer is protected from process related damages. A top electrode is formed on the adjusting layer and the adjusting layer and the free layer are etched utilizing the top electrode as a mask. A spacer layer is then formed, encapsulating the top electrode, the adjusting layer and the free layer. The spacer layer and the remaining portions of the MTJ stack are etched. A protective covering layer is deposited over the spacer layer and the MTJ stack.

Magnetoresistive Random Access Memory (MRAM) is a non-volatile memory technology that uses magnetic elements. For example, Spin Transfer Torque Magnetoresistive Random Access Memory (STT-MRAM) uses electrons that become spin-polarized as the electrons pass through a thin film (spin filter). STT-MRAM is also known as Spin Transfer Torque RAM (STT-RAM), Spin Torque Transfer Magnetization Switching RAM (Spin-RAM), and Spin Momentum Transfer (SMT-RAM).
FIG. 1 illustrates a conventional STT-MRAM bit cell 100. The STT-MRAM bit cell 100 includes magnetic tunnel junction (MTJ) storage element 105, a transistor 101, a bit line 102 and a word line 103. The MTJ storage element is formed, for example, from at least two ferromagnetic layers (a pinned layer and a free layer), each of which can hold a magnetic field or polarization, separated by a thin non-magnetic insulating layer (tunneling barrier). Electrons from the two ferromagnetic layers can penetrate through the tunneling barrier due to a tunneling effect under a bias voltage applied to the ferromagnetic layers. The magnetic polarization of the free layer can be reversed so that the polarity of the pinned layer and the free layer are either substantially aligned or opposite. The resistance of the electrical path through the MTJ will vary depending on the alignment of the polarizations of the pinned and free layers. This variance in resistance can be used to program and read the bit cell 100. The STT-MRAM bit cell 100 also includes a source line 104, a sense amplifier 108, read/write circuitry 106 and a bit line reference 107. Those skilled in the art will appreciate the operation and construction of the memory cell 100 is provided merely as an example.
With reference to FIGS. 2A-C, conventional MTJ storage elements generally are formed by first patterning a bottom fixed layer, forming a single damascene, depositing the tunneling barrier/free layer/top electrode stack, and performing a chemical mechanical polishing (CMP) step. Additional details are provided, for example, in M. Hosomi, et al., A Novel Nonvolatile Memory with Spin Transfer Torque Magnetoresistive Magnetization Switching Spin-RAM, proceedings of IEDM conference (2005), which is incorporated herein by reference in its entirety.
For example, as shown in FIG. 3, conventional MTJ storage elements generally are formed on a bottom electrode 302 such as a Si substrate. One or more seed layers (not shown) may be formed on the bottom electrode 302. An antiferromagnetic (AFM) layer 304 is first formed on the bottom electrode 302, and then a first ferromagnetic layer is formed on top of the AFM layer. The first ferromagnetic layer is "pinned" with a fixed magnetization to form a pinned layer. The pinned layer may include one or more layers, such as a bottom pinned layer 306, a coupling layer 308 typically formed of a non-magnetic metal such as ruthenium, and a top pinned layer 310. A tunneling barrier layer 312 is formed of an insulator such as a metal oxide on top of the pinned layer. A free layer 314 is formed of a second ferromagnetic layer directly on top of the tunneling barrier 312. A top electrode or hardmask layer 316 (e.g., tantalum) is formed on top of the free layer 314.
Next, the MTJ stack 300 is subjected to a magnetic annealing process in a vacuum. A pattern is then applied to the MTJ stack using a lithography technique. A photoresist (not shown in FIG. 3) is formed on top of the hardmask layer 316. The patterned cell size may be larger than the final size. Each of the aforementioned layers can be comprised of one or more layers or films.
Next, the MTJ stack 300 is etched using an etching process such as reactive ion etching. The etching process includes trimming the size of the photoresist, patterning the hardmask 316, removing the photoresist, etching the free layer 314, etching the barrier layer 312, etching the pinned layers 306, 308 and 310, and etching the pinning layer AFM 304. Next, a passivation layer is deposited to protect the MTJ storage element and the interlayer dielectric (ILD) insulator layer 318. A combination stack may be needed, along with a low deposition temperature to protect the MTJ and promote adhesion between the MTJ and ILD. Finally, planarization and metallization is performed.
The MTJ stack 300 is susceptible to damage during the etching process due to redeposition of etching byproducts. The step involving removal of photoresist may include processes such as oxygen ashing. Oxygen ashing can cause damage to the hardmask layer 316 during the photoresist removal process. Oxygen ashing can also cause damage to upper portions 320 of sidewalls of the free layer 314. As described above, the etching process proceeds from etching the hardmask layer 316 at the top of the MTJ stack 300 towards etching the pinned layers at the bottom of the stack. As the etching process progresses deeper down the MTJ stack, damage can be caused to sidewalls 322 of the free layer 314. As the etching process proceeds further down the stack, the upper portions 324 and lower portions 326 of the sidewalls of the barrier layer 312 may also be impacted.
As some of the etching byproducts may be conductive, damages to the sidewalls of the MTJ due to redeposition of such etching byproducts may lead to leakage paths, thereby reducing the magnetic resistance (MR) ratio of the MTJ. Such process related damages may result in significantly lower yields. There is a need for techniques which protect the MTJs from damages caused during the fabrication process.

Fabricating a magnetic tunnel junction storage element


A floral shipper comprising an inner container for supporting a floral grouping therein in an upright position and an outer container sized to receive therein the inner container and the upright floral grouping. The outer container has a bottom wall and a plurality of side walls extending upwardly therefrom. At least some of the side walls have a heightened portion that is greater than the height of the inner container and the floral grouping and have disposed therein ventilation openings for allowing air to circulate within the outer container. The ventilation openings are disposed in the at least some of the side walls so that when two or more outer containers are oriented adjacent one another, at least some ventilation openings of one outer container align with the ventilation openings of the adjacent outer container. A floral shipper assembly comprises a plurality of floral shippers and a pallet for supporting the floral shippers, wherein each shipper includes a width and length dimension such that when a plurality of the shippers are oriented adjacent one another, the overall width and overall length of the adjacent shippers substantially matches the respective width and length of the pallet onto which the floral shippers are arranged.

The present invention relates to a floral shipper assembly for shipping flowers and, more particularly, a floral shipper that provides efficient use of space and ventilation to the flowers contained in the shipper.
Floral shippers are used for shipping and presenting flowers. Prior art floral shippers typically comprise a round-shaped plastic container, also known in the art as a wet container, and a cardboard container surrounding the plastic container. A bunch, or grouping, of flowers is placed into the plastic container. Water is then poured into the plastic container to a desired level. The plastic container is then placed into a plastic bag that extends upward and surrounds the flowers. One or more of the plastic containers are then placed into the cardboard container, which is typically rectangular-shaped and has a height greater than that of the flowers. Cut-outs are provided a few inches below the top of and in the sides of the cardboard container for enabling the container to be grasped and lifted and for providing ventilation into the container during shipping. Before transporting large quantities of the floral shippers, the shippers are assembled on one or more standard-sized shipping pallets generally in side-by-side and stacked formation. Together, the two containers provide protection for and ventilation to the flowers.
These prior art floral shippers and the methods of shipping them have not satisfactorily kept up with the needs of the growing floral industry. As many flowers are shipped intercontinentally, the designs of floral shippers need to incorporate more efficient use of transportation space without compromising the quality of the flowers they carry and display.
By placing the round-shaped plastic container into the rectangular container the space in the corners of the rectangular container go unused. The plastic bag into which the round container is placed prevents air from the cut-outs from circulating around and in between the flowers, especially since the plastic bag usually is above the level of the cut-outs. Moreover, even without the plastic bags the flowers themselves tend to block the cut-outs and prevent air circulation.
When the floral shippers are assembled as an assembly onto a pallet, much of the available space of the pallet goes unused. This is because manufacturers of prior art floral shippers have typically placed greater emphasis on the accommodation of a predetermined amount of flowers rather on the means of shipping the flowers. Thus, for example, when multiple floral shippers of different sizes and shapes are assembled one on top of the other and/or side-by-side on a pallet, there is uneven and, consequently, unuseable space above the top of the shippers and/or to the side of the shippers. Moreover, because the containers vary so much in size and shape, there is no certainty or predictability as to whether a particular assembly of containers will cause one container to inhibit airflow to or from an adjacently-stacked container, in which case the quality of the flowers may be compromised. Over a period of time and a number of shipments, this unuseable space and uncertainty in stacking formations creates inefficiencies in cost, inconveniences when attempts are made to maximize space, and possible degradation in the quality of the flowers shipped.
There is a need for a floral shipper that provides the benefits of protecting and displaying flowers and that may be combined with other floral shippers while maximizing use of transportation space. In addition, there is a need for a floral shipper that can be quickly assembled, easily grasped and moved, and be assembled with other floral shippers with predictable and efficient use of space.
The present invention comprises a floral shipper assembly including an inner container for supporting a floral grouping therein in an upright position and an outer container sized to receive therein the inner container and the upright floral grouping. The outer container has a bottom wall and a plurality of side walls extending upwardly therefrom. At least some of the side walls have a heightened portion that is greater than the height of the inner container and the floral grouping. At least some of the side walls have disposed therein ventilation openings for allowing air to circulate within the outer container. The ventilation openings are disposed in the at least some of the side walls so that when two or more outer containers are oriented adjacent one another, at least some ventilation openings of one outer container align with the ventilation openings of the adjacent outer container.
The outer container is preferably sized to receive therein the inner container and the floral grouping, although the outer container may be sized to accommodate two or more of the inner containers and the upright floral grouping.
The ventilation openings are preferably disposed in opposing side walls of the outer container. This promotes cross ventilation on the inside of the outer container. Even more preferably, at least some of the ventilation openings are disposed immediately above the height of the inner container in the heightened portion of the side walls. At least some of the ventilation openings may also form slots in the outer container sized to permit fingers of the human hand to fit at least partially therethrough. The slots facilitate grasping the floral shipper and moving it from one location to another.
In a preferred embodiment, at least a portion of the periphery of the inner container matches and slidably engages the inside surface of one or more of the side walls of the outer container. The ventilation openings are disposed at a top edge of the at least some of the side walls for providing a path for air to circulate across and throughout an upper region of the outer container. Preferably, the plurality of side walls comprises at least two width side walls each having a width dimension and two length side walls each having a length dimension, wherein when two or more floral shippers are oriented side-by-side along their width dimension, the ventilation openings in the width side walls automatically align and provide a first path for air circulation across the shippers and when at least one of the two or more floral shippers is oriented side-by-side along the length dimension with another floral shipper, the ventilation openings in the length side walls automatically align and provide a second path for air circulation across the shippers that is transverse to the first path. This causes the paths to impinge one another, thereby causing the air to stir up, or circulate, randomly throughout the inside of the outer container.
In another preferred embodiment, the inner container includes a bottom wall and a plurality of side walls extending upwardly therefrom and the inner container side walls are set off from the outer container side walls by a lip extending outwardly from at least some of the inner side walls of the inner container. Even more preferably, the four side walls are substantially equal in height and form a substantially rectangular-shaped container.
In another preferred embodiment, the inner container includes an outwardly extending lip adjacent a top edge of at least some of the side walls of the inner container wherein the lip corresponds to and slidably engages at least a portion of the inside surface of the outer container. The side walls of the inner container may be tapered inwardly to facilitate stacking of the inner containers. Preferably, the side walls of the inner container include outwardly extending ribs extending substantially from the top to the bottom of the inner container for positioning and guiding the inner container into the outer container.
According to another aspect of the invention, a floral shipper assembly comprises a plurality of floral shippers and a pallet for supporting the floral shippers. Each floral shipper of the assembly includes a width and length dimension such that when a plurality of the shippers are oriented adjacent one another, the overall width and overall length of the adjacent shippers substantially matches the respective width and length of the pallet onto which the floral shippers are arranged.
In a preferred embodiment, the width and length of the floral shippers are 10 inches and 16 inches, respectively, and the width and length of the pallet are 40 inches and 48 inches, respectively, so that the assembly comprises four floral shippers oriented widthwise and three floral shippers oriented lengthwise. Preferably, the floral shippers include side walls having ventilation openings disposed therein such that when the shippers are aligned adjacent to one another the openings line up with one another to permit air to circulate from within one floral shipper to within the adjacent floral shipper.


An apparatus and a method for cleaning wafers with contact holes or via holes are provided. The apparatus for cleaning wafers comprises a first arm, a second arm, a fixing device, a rotating device and a spraying device. The fixing device, disposed on the first arm, fixes the wafer in a manner such that a surface of the wafer, with contact holes or via holes, faces downward. The rotating device, disposed above the fixing device, rotates the fixing device. The spraying device, disposed on the second arm in a manner such that the spraying device is located beneath the fixing device, sprays the water upwards to the surface of the wafer. By the apparatus and method according to the invention, the possibility of native oxide remaining in the contact holes or the via holes is greatly reduced. In addition, the removal of defects from the surface of the wafer is enhanced.

1. Field of the Invention
The invention relates to an apparatus and method for cleaning wafers with contact holes or via holes; in particular, the invention relates to a wafer-cleaning apparatus and method that disposes the wafer in a manner such that its surface, with contact holes or via holes, faces downward during cleaning.
2. Description of the Related Art
In ultra large scale integration (ULSI) process, for example, before wafers enter a high-temperature chamber or after being subjected to thin-film etching, the wafers must be subjected to chemical cleaning, de-ionized (DI) water rinsing and drying so the surface of the wafer can attain the requirement of high cleanliness. Wafer-cleaning technique affects the yield, the quality of the device and the reliability. Wafer cleaning removes contamination on the surface of the wafer, such as particles, organic and metal ions.
The wafer-cleaning technique comprises a wet chemical cleaning and a physical cleaning technology. No matter which procedure is used, a step in which DI water sprays or cleans the wafer is included.
In FIG. 1, a conventional wafer-cleaning apparatus, using DI water, is shown. Such apparatus comprises a vacuum chuck 22, a rotary shaft 24 and a sprayer 26. The vacuum chuck 22 fixes a wafer 10 by vacuum. The rotary shaft 24, disposed beneath the vacuum chuck 22 and connected with the vacuum chuck 22, rotates the vacuum chuck 22. The rotary shaft 24 rotates at high speed so that the wafer 10, disposed on the vacuum chuck 22, rotates at high speed. The sprayer 26, disposed above the vacuum chuck 22, sprays DI water downwards to the surface of the wafer 10, as shown by arrow A and arrow B.
In FIG. 2, a cross-section of the wafer 10 with via holes is shown. The wafer 10 is provided with a substrate 12, a metal layer 14 and a dielectric layer 16. The dielectric layer 16, for example, is oxide material. The via hole 30, defined by etching, is located inside the dielectric layer 16. When the wafer 10, as shown in FIG. 2, is disposed in a manner such that a surface S, with the via hole 30, of the wafer 10 faces upward, as shown in FIG. 1, the spraying DI water remains in the via hole 30 due to gravity. As a result, native oxide 40 is formed inside the via hole 30 so as to affect the characteristic of the device. In addition, because of gravity and the angle of the spraying water, defects, generated on the surface of the wafer, are splashed up by the water, easily fall back onto the surface of the wafer. Thus, the problem of defects remaining on the surface of the wafer often occurs.
In order to address the disadvantages of the aforementioned wafer-cleaning technique, the invention provides an apparatus and method for cleaning wafers with contact holes or via holes that can reduce the possibility of native oxide remaining in contact or via holes.
Another purpose of the invention is to provide an apparatus and method for cleaning wafers with contact holes or via holes that can enhance the removal of defects from the surface of the wafer.
Accordingly, the invention provides an apparatus for cleaning wafers with contact holes or via holes comprising a first arm, a second arm, a fixing device, a rotating device and a spraying device. The fixing device, disposed on the first arm, fixes the wafer in a manner such that a surface of the wafer, with contact holes or via holes, faces downward. The rotating device, disposed above the fixing device, rotates the fixing device. The spraying device, disposed on the second arm in a manner such that the spraying device is located beneath the fixing device, sprays the water upwards to the surface of the wafer.
Furthermore, the fixing device is a vacuum chuck, and the spraying device is a sprayer.
The spraying device comprises a nozzle. The apparatus further comprises an oscillator and a controller. The oscillator, disposed on the second arm, communicates with the nozzle. The controller electrically connects to the oscillator.
The invention provides a method for cleaning wafers with contact holes or via holes comprising the following steps. First, a substrate is provided, and at least one dielectric layer is formed on a surface of the substrate. Then, the dielectric layer is etched to form the contact holes or via holes, and the substrate is disposed in a manner such that its surface, with contact holes or via holes, faces downward. Finally, the water is applied upwards to the surface of the substrate.
Furthermore, the water is de-ionized water.

Apparatus and method for cleaning wafers with contact holes or via holes


The present invention relates to a warning apparatus which can continuously monitor a normal condition wherein an alarm sound can be produced. When a high level judgement signal (W) indicating safety is input, an inaudible frequency signal is supplied from a V-F converter (11) to a speaker (13) so that a warning sound of an inaudible frequency is generated, while when a low level (zero) judgement signal (W) indicating danger is input, an audible frequency signal is supplied from the V-F converter (11) to the speaker (13) so that a warning sound of an audible frequency which can be heard by personnel is generated. Furthermore, when an output current of an inaudible frequency or an audible frequency is supplied to the speaker (13), the output current is sampled by a current transformer (21) of a monitoring circuit (20), and amplified and rectified to give a direct current output signal (SN), thereby enabling verification that the warning apparatus is normal.

To warn nearby people of danger, for example when a train is approaching a railway crossing, or when an abnormal situation arises in a factory or the like, in general a warning sound is produced using a siren, a bell or the like. More recently, a speaker or a piezoelectric buzzer has been used for producing the warning sound.
With such a conventional warning apparatus wherein a dangerous situation is notified by producing a warning sound, the warning apparatus is only driven to produce the warning sound when the dangerous situation arises, while at normal safe times, it is not driven so that the warning sound is not generated.
However, in particular at factories and the like, dangerous situations wherein the warning apparatus is operated seldom arise. Hence, it cannot be known if there is a fault in the warning apparatus. It is therefore uncertain if the warning apparatus can normally produce a warning sound when a dangerous situation actually arises, so that there is extreme danger to nearby personnel in the case of a fault such that the warning sound is not sounded.
The present invention takes into consideration the above situation with the object of providing a highly reliable warning apparatus which can verify if a warning sound can be produced, even at normal safe times where it is not necessary to warn personnel.


An image recording apparatus of the present invention comprises a conveying roller which conveys a print medium, a print head which conveys each of a plurality of sub-regions that are obtained by dividing the region of the print medium and records a test pattern each time the print medium is conveyed by the conveying roller in the region of the print medium corresponding to the convey amount of one rotation of the conveying roller, a CCD which reads a plurarity of the test patterns, and a control unit which calculates an interval between the previously recorded test pattern and the test pattern recorded after the print medium is conveyed, calculates the amount of deviation between the calculated interval and a predetermined interval as to all the test patterns recorded on the print medium, and calculates the average value of the amounts of deviation.

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-075914, filed Mar. 16, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a print apparatus, and more particularly, to an image recording apparatus such as an inkjet printer capable of correcting a sheet convey amount error using a predetermined test pattern.
2. Description of the Related Art
Conventionally, in inkjet printers of a type for performing recording by ejecting ink from a print head having a plurality of nozzles, a serial type is mainly used in which an image is formed by reciprocating the print head above a print medium along a main scan direction while intermittently conveying the print medium. In this serial type, however, a problem arises in that a gap is caused between the lines of printed characters or the lines thereof overlap depending upon the accuracy of a convey amount of the print medium.
To improve the sheet convey accuracy, there is conceived an idea for improving the accuracy of parts used in a print medium convey mechanism and improving the assembling accuracy of the convey mechanism. However, this idea requires a higher level of check and management. That is, in the inkjet printer, the mechanical improvement of the media convey accuracy results in an increase in a product cost.
To solve the above problem, Jpn. Pat. Appln. KOKAI Publication No. 5-96796 discloses a technology as to xe2x80x9crecording method and apparatusxe2x80x9d. According to this technology, a test pattern is printed on a print medium and read by a reading unit, a sheet convey amount error is calculated based on a result of the read test pattern, and the print medium is conveyed based on a correction value for correcting the error.
That is, in this technology, a plurality of vertical lines (test pattern) are printed along a sub-scan direction, the leading and trailing end addresses of the respective vertical lines are read by the reading unit, and the difference (Exe2x88x92S) between the leading end address S of a noted vertical line and the trailing end address E of a vertical line in front of the noted vertical line is determined. Then, the sheet convey amount error in correspondence to the difference (Exe2x88x92S) is corrected, and a thus corrected sheet convey amount is stored in a memory.
When an image is actually recorded, a sheet convey amount error according to each line feed position is referred to from the memory, and a drive signal based on the sheet convey amount error is applied to a sheet convey motor. With this operation, the print medium can be conveyed accurately over the entire surface thereof.
In the technology disclosed in Jpn. Pat. Appln. KOKAI Publication No. 5-96796, however, the vertical lines as the test pattern are printed as many as 70 lines in the vertical direction of an A4 size print medium and are read by the reading unit one by one in order to calculate the correction value for correcting the sheet convey amount error. That is, the vertical lines are printed the number of times corresponding to the number of times of convey of the print medium that are necessary to record an image, the amount of dislocation of the print medium to a predetermined sheet convey amount is read over the entire surface of the A4 size print medium, and a correction value for correcting a sheet convey amount error, which arises each time the print medium is conveyed, is calculated. While this method is effective in the A4 size print medium, it is hard to say that this method is also effective to a print medium larger than the A4 size and to a rolled print medium because it requires a long processing time in them.
In contrast, various types of print medium such as a thin sheet, a thick sheet, and a sheet having a large or small coefficient of friction are used in the inkjet printer. In this circumstances, a problem arises in that even if the same sheet convey pulse is supplied to a sheet convey motor, a recording sheet as a print medium is conveyed in a different amount depending upon whether the print medium is thick or thin and depending upon whether or not the print medium has a large coefficient of friction. In this point, the conventional technology records test data over the entire surface of a print medium and calculates the correction value for correcting the sheet convey amount error even if the above disadvantage exists, and thus it requires a long processing time.
An object of the present invention is to provide an inkjet printer capable of effectively determining a sheet convey amount error and calculating an appropriate correction value without recording and reading teat data over the entire region of a print medium. Another object of the present invention is to provide an image recording apparatus such as an inkjet printer capable of using print medium having a different thickness, determining an appropriate sheet convey amount error for each sheet having a different thickness and a different coefficient of friction and calculating an appropriate correction value easily and promptly.
In more detail, an object of the present invention is to save the useless consumption of time, an amount of ink, and sheets when a sheet convey amount error is measured by using a length corresponding to the sheet convey amount of the one rotation of a conveying roller as a measurement range when the sheet convey amount error is measured.
Another object the present invention is to permit a sheet convey multiplication ratio for correcting deviation in convey amount, which is a factor for causing the above sheet convey amount error, to be independently calculated and to permit the sheet convey multiplication ratio to be calculated according to each recording mode.
To achieve the above objects, according to a first aspect of the present invention, there is provided an image recording apparatus comprising: a conveying roller which conveys a print medium; a print head which is capable of scanning the print medium in a direction perpendicular to the direction where the print medium is conveyed by the conveying roller and which records a test pattern on the print medium; a scanner which reads the test pattern recorded on the print medium; and an arithmetic operation circuit which calculats the convey amount error of the conveying roller based on the result detected by the scanner, wherein the conveying roller conveys each of a plurality of the sub-regions that are obtained by dividing the region of the print medium, which corresponds to the convey amount of the print medium conveyed by the one rotation of the conveying roller, at a time; the print head records a test pattern each time the print medium is conveyed by the conveying roller and records a plurality of test patterns in the region of the print medium corresponding to the convey amount of the one rotation of the conveying roller; and the arithmetic operation circuit: calculates an interval between (two) test patterns that are adjacent to each other along the direction where the print medium is conveyed; calculates the amount of deviation between the calculated interval and an ideal interval as to all the test patterns recorded on the print medium; and calculates the average value of the amounts of deviation.
Further, according to a second aspect of the present invention, there is privided an image recording apparatus comprising: a conveying roller which conveys a print medium; a convey motor which applies rotational drive to the conveying roller; a print head which records test patterns on the print medium; a carriage which causes the print head mounted thereon to perform scan in a direction perpendicular to the direction where the print medium is conveyed by the conveying roller; a sensor which optically reads the test patterns recorded on the print medium; and an arithmetic operation circuit which calculates the convey amount error of the conveying roller based on the result detected by the scanner, wherein the print head records a test pattern each time the print medium is conveyed by the conveying roller and records a plurality of test patterns in the region of the print medium corresponding to the convey amount of the one rotation of the conveying roller; and the arithmetic operation circuit: calculates an interval xcex94DAn of test patterns that are adjacent to each other along the direction where the print medium is conveyed as to intervals of all the test patterns and calculates a total sum DA of the intervals; calculates the amount of deviation DB between the thus calculated total sum DA of the intervals and a total sum D of ideal intervals; calculates a first correction amount xcex94DBmean by calculating the average value of the amount of deviation DB between the total sums DA and D; calculates a primary correction interval xcex94DCn by adding the first correction value xcex94DBmean to the intervals xcex94DAn of the respective test patterns; calculates a second correction amount xcex94DDn by calculating the difference between the first correction amount xcex94D and the primary correction interval xcex94DCn; and adds the first correction amount xcex94DBmean to the second correction amount xcex94DDn.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.


A curtain coating method and apparatus using a rotatable or slidable coating plate and in which a coating liquid freely falls in the form of a thin film from a hopper. The thin film collides with a web continuously running and circumferentially turning around a backup roller to coat the web. The coating plate is rotated or slid to retract so that the freely falling coating liquid reaches the web so as to coat the web after the freely falling coating liquid flows along a checking plate which is doglegged in section and provided on a forward end of the coating plate, thereby coating the web with an even thickness at the start of coating operations.

1. Field of the Invention
The present invention relates to a method for forming a coating with various kinds of liquid compositions (hereinafter referred to as "a coating liquid") onto a continuously running belt-like support (hereinafter referred to as "a web") used in manufacturing photosensitized material film; photographic print paper; magnetic recording materials such as magnetic recording tapes, etc.; adhesive tape; information recording paper such as pressure-sensitive paper, heat-sensitive paper, etc.; other photographic printing plate, and so on. More particularly, the present invention relates to a curtain coating method and an apparatus therefor.
2. Description of the Related Art
A curtain coating method and an apparatus therefor are representative of a method and apparatus in which a coating liquid in the form of a thin film is made to collide with a running web so as to coat the running web with the coating liquid.
Curtain coating method and apparatus therefor include a method and apparatus wherein a freely falling curtain film composed of one or more kinds of coating liquids is made to collide with an object to be coated so as to form a coating film on the object. The basic curtain coating method and apparatus therefor have been used for many years for coating furniture, iron plates, etc. Recently, however, the curtain coating method has been applied to a field in which accuracy is particularly required, such as in manufacturing photosensitized materials, as disclosed in U.S. Pat. No. 3,632,374 or U.S. Pat. No. 3,508,947.
In such a method and apparatus, it is extremely important to evenly apply the freely falling curtain film at the time coating is started.
Compared with a slide-hopper-type bead coating method, the curtain coating method is required to perform coating at a higher speed. Therefore, the flow of the fed liquid is required to be increased correspondingly. As a result, forming an even coating becomes difficult at the start of coating. In the case where even coating cannot be performed, problems may occur in products because of contamination due to spattering of the coating liquid, contamination of a roller in the stage after a drying zone due to a not-yet-dried thickly-coated portion, or the like.
A curtain coating method is disclosed, for example, in Japanese Patent Publication No. Sho-49-24133, in which a rotatable or slidable device called a deflector (coating plate) is used for dual purposes, namely, for forming a stable curtain film to feed a predetermined quantity of coating at the start of coating and for collecting the coating liquid prior to the start of coating.
FIG. 4 shows the coating method disclosed in U.S. Pat. No. 3,632,374. A coating liquid 13 made to flow onto a slide surface 12 of a slide hopper 11 and then freely falls in the form of a thin film from a forward end portion 14 of the slide surface 12 to form a curtain film 15. The curtain film 15 is made to collide with a running web 16 so as to form a coating thereon. Before coating is started, a rectangular plane coating plate 18 is inserted so as to interrupt the curtain film 15 so that the coating liquid flows along the coating plate 18 so as to be collected in a collecting tank 21. At the start of coating, the coating plate 18 is rotated about a fulcrum 19 so that the curtain film 15 reaches the web 16 to thereby perform coating. Further, the opposite side ends of the curtain film 15 are held by edge guides 20 extending from the forward end portion 14 of the slide surface 12 to a position lower than the position at which the curtain film 15 collides with the web.
This method has an effect that, in the case of single layer coating, the free falling curtain film 15 is received by the coating plate 18 prior to the start of coating so that the coating liquid can be collected in the collecting tank 21 so as to be used again. However, the apparatus has the following three defects. The first defect is that the curtain film 15 is required to be sufficiently high in order to rotate or slide the coating plate 18 and, therefore, the use of the apparatus is limited in the case where there is not sufficient space. The second defect is that non-coating portions exist at the opposite side ends of the curtain film 15 between the edge guides 20 and the coating plate 18. The third defect is that although the coating liquid is applied onto the entire width of the web 16 at the same time, at the instance when the rotating and retreating coating plate 18 is separated from the curtain film 15 at the start of coating a thickly coated portion is formed with the coating liquid lump portion.
U.S. Pat. No. 4,922,851 and U.S. Pat. No. 4,851,268 disclose a coating apparatus which attempts to overcome the above-mentioned defects. Namely, the coating plate is caused to effectively function to realize smooth coating, that is, coating without the formation of thick portions, even in the case where film formation is difficult in the slide-hopper-type curtain coating apparatus. In this apparatus, an L-shaped coating plate 9 as shown in FIGS. 3(a) and 3(b) is used in a manner so that the sliding speed of the coating plate 9 can be suitably selected.
However, in the method and apparatus disclosed in the above U.S. Pat. No. 4,922,851 and U.S. Pat. No. 4,851,268, when the coating plate 9 is removed, a freely falling coating-liquid film 5 wets the lower surface of a forward end portion of the coating plate 9 as shown in FIG. 3(a) so that the liquid is finally moved onto the web 6 together with the liquid to be applied onto the web 6 so as to form an excessive bead portion 22 as shown in FIG. 3(b), and a part of the bead portion 22 becomes a thickly coated portion at the start of coating, while another part swings so as to make the bead unstable, resulting in unevenness in the coated film thickness. Assume that a point where the freely falling coating-liquid film 5 falls down onto the web 6 is a coating point and that an angle (hereinafter referred to as "coating angle") between a vertical line and a straight line starting from the center of rotation of a backup roller to the coating point is .PSI., coating has been difficult particularly in the case where the coating angle .PSI. is larger than 30 degrees in the conventional method and apparatus.

Curtain coating method and apparatus utilizing checking plate for controlling liquid flow


The present invention is directed to a modified amidotransferase. The amino acid sequence of the modified amidotransferase differs from the amino acid sequence of a native E. coli glutamine PRPP amidotransferase in that one or more amino acid residues of the modified amidotransferase are substituted at positions equivalent to amino acid positions in Bacillus amidotransferase selected from the group consisting of 282, 283, 307, and 347 of SEQ ID NO:1, wherein the modified amidotransferase is less sensitive to end-product inhibition than is the native E. coli glutamine PRPP amidotransferase.

This invention relates to the deregulation of purine nucleotide biosynthesis. More particularly, this invention is directed to the modification of glutamine phosphoribosylpyrophosphate (PRPP) amidotransferase to decrease end-product inhibition of glutamine PRPP amidotransferase activity.
Glutamine PRPP amidotransferase catalyzes the initial reaction in de novo purine nucleotide synthesis and is the key regulatory enzyme in the pathway. Genes encoding glutamine PRPP amidotransferase have been cloned from more than 20 organisms including bacteria, eukarya, and archea. In particular, the enzymes from Escherichia coli and Bacillus subtilis have been purified to homogeneity and are well-characterized, including having the X-ray structures determined for these enzyme species. The E. coli and B. subtilis enzymes are both homotetramers and are representative of two classes of glutamine PRPP amidotransferases. Enzymes of the B. subtilis class are synthesized with an NH2 terminal propeptide and an Fexe2x80x94S center, whereas enzymes of the E. coli class have neither.
Purine nucleotide biosynthesis is regulated, at both the gene (transcription/translation) and the protein (enzymatic activity) level. Attempts at increasing the biosynthesis of purine nucleotides have focused on the deregulation of genes encoding pathway enzymes. However, the enzymatic activity of a key pathway enzyme, glutamine PRPP amidotransferase, is inhibited by the pathway end-products, adenine and guanine nucleotides. Therefore an effective strategy for enhancing host cell production of purine nucleotides includes the use of a modified glutamine PRPP amidotransferase, wherein the modification reduces the sensitivity of the enzyme to end-product inhibition by adenine and guanine nucleotides.
The two classes of glutamine PRPP amidotransferase enzymes (as represented by the E. coli and B. subtilis enzymes) exhibit different end-product inhibitory patterns by adenine and guanine nucleotides. GMP is the single strongest inhibitor of E. coli glutamine PRPP amidotransferase, and AMP is the strongest inhibitor of the B. subtilis enzyme. Notwithstanding this difference, there is one common distinctive characteristic of the inhibition by nucleotides. Certain pairs of adenine and guanine nucleotides give more than additive inhibition compared to the individual nucleotides, a phenomenon called synergistic inhibition. AMP plus GMP has been reported to be a strong synergistic nucleotide pair for the E. coli enzyme, although more recent experiments suggest that GDP plus AMP may be the most effective synergistic pair. The strongest synergistic pair for the B. subtilis enzyme has been reported to be ADP plus GMP.
The synergistic inhibition of glutamine PRPP amidotransferase implies the existence of separate binding sites for adenine and guanine nucleotides on each subunit. X-ray structures of B. subtilis and E. coli enzymes have identified four nucleotide binding sites per half-tetramer, two equivalent allosteric A sites between subunits, each with an adjacent catalytic C sites. It has been reported that synergistic binding of GMP to the A site and AMP to the C site could account for the synergistic inhibition of the E. coli enzyme.
A more systematic study of the mechanism for synergistic inhibition of the B. subtilis glutamine PRPP amidotransferase, as reported herein, confirms that ADP and GMP are the most synergistic pair and demonstrates that synergistic inhibition results from synergistic binding. An X-ray structure of a ternary enzyme ADP-GMP complex establishes that ADP binds to the A site and GMP to the C site and that synergism results from a specific interaction between the xcex2-phosphate of a nucleoside diphosphate in the A site and a nucleoside monophosphate in the C site. These results establish the mechanistic basis for synergism.
Purine nucleotide production in bacteria is controlled and limited by regulation of gene expression as well as regulation of the enzymatic activity of pathway enzymes such as glutamine PRPP amidotransferase. This regulation limits production yields during commercial biosynthesis of inosine, as well as adenine and guanine nucleosides and nucleotides. Typically, commercial production of the nucleosides and nucleotides is carried out using Bacillus species that are genetically deregulated. However, due to feedback inhibition of glutamine PRPP amidotransferase, nucleotide overproduction in these genetically deregulated strains is less than maximal. The elimination, or at least the reduction, of nucleotide end-product inhibition of glutamine PRPP amidotransferase activity will further enhance the production yield of purine nucleotides.
In accordance with one embodiment of the present invention a modified glutamine PRPP amidotransferase is prepared that is desensitized to inhibition by purine nucleotides. The modified enzyme has at least one amino acid of the allosteric A sites or the catalytic C sites of said amidotransferase substituted with a non-native amino acid, wherein the substitution reduces the sensitivity of the enzyme to end product inhibition relative to the native glutamine PRPP amidotransferase enzyme. Furthermore, the present invention encompasses gene sequences that encode for the modified glutamine PRPP amidotransferase.
In accordance with one embodiment a method is provided for producing purine nucleotides. The method comprises the steps of culturing a host cell that comprises gene sequences encoding for a modified glutamine PRPP amidotransferase, wherein the modified glutamine PRPP amidotransferase has reduced sensitivity to end-product inhibition.

Deregulation of glutamine PRPP amidotransferase activity

The Board of Trustees of the University of Illinois


Group IVB metal metallocenes of bis(1-methyl fluorenyl) diphenyl silane and bis(1-methyl fluorenyl) dimethyl tin are disclosed, plus their use in the production of polyolefins, including isotactic polypropylene.

It is well known that many metallocenes can be useful for the polymerization of some olefins. Particularly it has been noted that metallocenes can be combined with aluminoxanes to produce catalyst systems of high activity for the production of polyolefins. A particularly interesting type of metallocene for olefin polymerization is the so-called bridged sandwich-bonded metallocene in which the ligand of the metallocene comprises two cyclopentadienyl-like groups connected through a bridging group. Some of the bridged sandwich-bonded metallocenes when used in the polymerization of olefins having three or more carbon atoms have been found to be useful for producing polymers having different types of microstructure as reflected by tacticity determined by spectroscopic techniques such as infrared and NMR. A discussion of such techniques is disclosed in Zambelli et al, J. Polym. Sci. Part C, 84, 1488,(1962); Lotz et al, Macro Molecules, 21, 2375, (1988); Haftka et al, J. Macromol. Sci. Phys., 830, 319,(1991); and Youngman et al, Macromol. Res., 2, 33 (1967).
It is well known in the art that the microstructure tacticity of a polyolefin molecule can have a significant effect upon the physical properties of the polymer. Other things which affect the polymer properties include the type of monomer, and comonomer if employed, the weight average molecular weight (M.sub.w) of the polymer, the molecular weight distribution, and the composition distribution of the resin. Accordingly, for producing commercially desirable polymers, it is important to find metallocene catalysts which give the desired combination of polymer properties plus commercially practical polymerization activities.
Many sandwich-bonded bridged metallocenes have been at least proposed in the open literature and the patent literature and there have been some studies of the effects of varying the structure of the ligand used in the metallocene. One example of such a study is disclosed in the New Journal of Chemistry, Vol. 14, No. 6-7, pages 499-503 (1990). While the patent literature contains broad assertions regarding the particular types of polymers that will be produced with specific types of metallocenes, subsequent work has revealed that those generalizations are too broad.
For example, while U.S. Pat. Nos. 4,794,096 and 4,769,510 teach that bridged chiral, stereorigid metallocene catalysts are capable of producing polymers having high levels of isotactic microstructure, the only actual examples of such metallocenes are racemic ethylene bridged bisindenyl or bis-tetrahydroindenyl metallocenes which must be isolated from mixtures of the racemic and meso isomers by difficult, tedious, expensive fractional crystallizations or similar techniques. Further U.S. Pat. No. 4,892,851 shows that that the bridged, chiral, sterorigid metallocene cyclopentadienyl isopropylidene fluorenyl zirconium dichloride produces highly syndiotatic polypropylene rather than isotactic polyproplyene. Also Dr. Abbas Razavi in a paper at the SPO 92 meeting reported that the bridged, chiral, stereorigid metallocene racemic [bis(3-methyl indenyl) ethylene] zirconium dichloride yields a highly amorphous polypropylene rather than an isotactic polypropylene. The present inventors have also noted that certain bis-unsubstituted fluorenyl bridged metallocenes produce amorphous polypropylene having only low levels of isotaticity as determined by NMR.
An object of the present invention is to provide compositions comprising bis-fluorenyl bridged sandwich-bonded metallocene which are suitable for use in preparing isotatic polypropylene even without separation of racemic and meso isomers.
Another object of the present invention is to provide processes for polymerizing olefins using the special metallocene compositions.
In accordance with yet another aspect of the present invention, there is provided processes for producing novel isotactic polymers.
Other aspects, objects, and advantages of the present invention will become apparent from a review of the following disclosure.

Bis fluorenyl metallocenes and use thereof


The claimed subject matter relates to a computer-implemented architecture that can, at a high level, store query results in a location-independent manner in order to facilitate caching of local results. To store query results in a location-independent manner such that cached results to location-based queries can be useful, the architecture can further include a mechanism for encoding a surface or area (e.g., the earth) based upon document density rather than geography. The encoding mechanism can also organize an inverted index so that no join operation is required to return valid results to a location-based query. The architecture can also include a mechanism for determining when previously cached results are adequate to satisfy a query.

Maps have been created and used by mankind for thousands of years. They facilitate travel, logistics, planning, defining the boundaries of property rights, and the like. Cartography has changed dramatically because of advances in technology. The traditional tools of cartography such as the telescope, the sextant, and the compass are being replaced by digital photography, GPS surveying and computer databases. In addition to better surveying technologies, map presentation technology has changed dramatically as well. Traditional maps that were simply hand-drawings on paper are rapidly being replaced by computer displays that can provide dynamic information tailored to a specific user.
In addition, fixed maps, e.g. maps that have a fixed view and fixed information, are being replaced by dynamic maps where a user can select a specific view and customize the information that is displayed. Furthermore, searching functionality is common in many computer-based maps. A user of computer-based maps can usually select a position and conduct a search for specific information. That information may then be represented on the user's customized map, creating a representation that is tailored to the user's request(s).
Oftentimes the information sought out by a user may be information associated with a position or object rather than a physical characteristic. For example, one common use of interactive maps is to allow a user to search for a specific kind of business. For example a user may search for all businesses that sell pizza within a certain distance from a specific location. The results to such a search can yield a computer-implemented map that displays markers indicating all the pizza parlors in the relevant area. Moreover, in addition to the advances in interactive mapping, location-based information-gathering technologies have advanced rapidly as well. For instance, modern demographic techniques have arisen to determine very detailed information about locations, persons, businesses, etc. Furthermore, satellite images for every region of the earth have been obtained, and several conventional systems that utilize satellite (or other orthographic-style) imagery in connection with street-side imagery are in being developed and enhanced. The demands for these and other location-based information will continue to increase as more advances are made in the relevant fields.
However, with the increased availability of location-based information, it is becoming increasingly important for a mapping and/or location-based query system to provide efficient storage and retrieval mechanisms to reduce the resources required to operate the system. The combination of the aforementioned difficulties has resulted in inefficient mechanisms for facilitating location-based searching. No effective technology has previously been developed to adequately resolve the current difficulties related to location-based searching.
For example, there are inefficiencies in the prior art with regard to processing relevant information within a data store. Typically, a data store of location-related information utilizes two kinds of inverted indices, one for keywords and another for the location. The first inverted index can be implemented as a 2-dimensional array where the first column is an array of keywords and the second column is associated with a set of documents that contain that keyword. The second inverted index is also sometimes implemented as a 2-dimensional array in the prior art, where the first column is a location and the second column is a set of documents associated with the position indicated in the first column. When a user performs a search, there are generally at least three criteria associated with the search (1) the location to be searched; (2) the keyword to search; and (3) limiting criteria.
The limiting criteria can be, e.g. a radius limit that extends from the location to an arbitrary distance. Additionally or alternatively the limiting criteria can be a limit on the number of results returned such as returning the 100 closest results. Generally, the first inverted index is searched in which a set, S1, of documents are made that match the keyword. Next, some conventional systems perform a second search on the second inverted index. The search looks to the first column to determine how close that location is to the location is in the search string. If the limiting criteria are satisfied, the set is included in set S2. The computer continues to search and all sets that are returned are returned are added to S2. When the search of the second inverted index is finished the set S2 is complete. Now the two sets must be intersected. The results are the intersection of S1 and S2, (S1∩S2). The aforementioned processed is a join operation (e.g., an inner join) for joining two inverted indices. This process is extremely expensive in terms of system resources and, as such, often referred to as the "join problem" because of the inefficiencies associated with this process.
In addition to the join problem, other difficulties exist. For example, many conventional systems rely exclusively on "back-end" evaluation of location-based queries. Back-end access typically involves disk reads, which can be orders of magnitude slower than accessing data in a cache. Implementing a system with a front-end cache is a common strategy in the prior art to increase efficiency in some fields. However, traditional caching schemes have failed to adequately employ caches for location-based queries because it is very rare for a search to be carried out from exactly the same location and with exactly the same keyword.
Generally, a location-based search involves two or three parameters. They are conducted as a search of a keyword from a certain location. There are no known strategies to determine if cached results are sufficient for a subsequent search made from a nearby location rather than from an exact location. This occurs because data in a cache is usually constructed based upon a previous search, such as the one described above, that goes to the back-end and joins two inverted indices. Hence, the data in the cache will be based upon a key that contains both keyword and location information. Thus, in order to retrieve a record (from either the back-end or the cache) the key must match exactly in both dimensions, which makes cached results of little value in conventional systems.
Therefore, what is needed is a solution that can remedy both the join problem and, as well, make use of a cache for storing location-based results in a manner that can be employed for subsequent queries, even when the location is not an exact match.

Indexing and caching strategy for local queries


A multiple head signal distribution system, for reading data on a videodisc having a center, the data disposed on a continuous track on the disk and having a beginning wherein the disk is read with a plurality of heads, each head reading the same data at time delayed intervals.

The invention relates to a multiple head signal distribution system. More particularly, the invention relates to a system in which an information bearing disk is read with a plurality of staggered heads, for reading the same information at predetermined delayed intervals.
The demand for information services, especially movie and audio programs has increased dramatically. In the last few decades, the American public has outgrown the few viewing options offered by broadcast TV. They have demanded the ability to choose from a large variety of programming options.
Further, the viewing consumer wants to watch the program of their choice, and they want to watch it at a convenient time. Often, it is not possible to arrange one's life around the scheduled program start times. What is desired is the ability to watch the program at the desired start time.
The popularity of videocassette rentals has stemmed from the ability to choose from a large variety of movies, and then watch them when desired. However, renting videocassettes has its shortcomings. One must travel to the video store not only to select a program to watch, but also to return the videocassette the next day.
Pay-per-view programs have gained in popularity in part because of their convenience. However, they have three main shortcomings: selection, inconvenient start times, and inability to "stop" the program when the viewer is interrupted.
From the random accessibility of videocassettes, viewers have grown accustomed to watching a program when they wish, and to having the ability to pause or rewind the program when they are interrupted during its play. Pay-per-view programs do not give the viewers this convenience. One must begin watching the pay-per-view at the scheduled time, and must either stay glued to the television set, or risk missing a portion of the show.
Others have proposed systems for delivering video programs to a viewer.
U.S. Pat. Nos. 4,567,512 and 4,590,516 to Abraham both disclose a recorded program communication system.
U.S. Pat. No. 4,890,320 to Monslow et al discloses a television broadcast system for selective transmission of view-chosen programs at viewer-requested times. However, this system does not allow multiple viewers to view the same program with differing start times.
U.S. Pat. No. 5,133,079 to Ballantyne et al discloses a method and apparatus for distribution of movies in which the video signal is compressed for transmission to a subscriber.
U.S. Pat. No. 5,172,413 to Bradley et al discloses a video delivery system and method in which multiple versions of the same program are transmitted, each time delayed by five minutes. However, this system requires a separate video play unit and separate copy of the program for each time delayed version of the program transmitted to the subscribers.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.

Multiple head signal distribution system


The present invention relates to a high speed printing system, in which the printing intensity of each type element, applied onto a record media, is varied in accordance with the surface area of the type element. The system employs a double control mode, in each hammering operation, for carrying out the variation of the printing intensity. The double control mode is comprised of a first control mode and a second control mode, which follows immediately after the first control mode. In the first control mode, a maximum energizing current is supplied to a hammer means, comprising a dc motor, for hammering a selected type element to produce a desired character on the record media. In the second control mode, an energizing current is applied to the hammer means. The latter energizing current has variable peak amplitude which is suitable for carrying out fine control of the printing intensity in accordance with the size of the surface area of each type element.

(1) Field of the Invention
The present invention relates to a high speed printing system and, more particularly, to a means for controlling a variable intensity printing applied to a record media.
(2) The Prior Art
In a printing system, it is necessary to vary the intensity of the printing which is applied to the record media in accordance with the size of the surface area of the characters. This is done in order to obtain high quality printed characters, having uniform deepness, regardless of the size of the surface area of the characters. In one prior art printing system a single control mode is employed for hammering each type element of the printer. In the single control mode, an energizing current having a constant amplitude is supplied to a hammer means during the flight of each type element toward a platen. However, the energizing current varies only when a type element selected to be hammered requires a respective predetermined printing intensity. The above mentioned prior art printing system has the following disadvantage: it is difficult to carry out a fine control of the printing impact and, accordingly, a fine control of the deepness. This is because, although the energizing current is slightly varied, the hammering speed of the type element at the platen and the flight time of the type element are widely varied.
Generally, there are two methods for hammering the type elements. In a first method, the hammering operation of a selected type element and the spacing operation of a carrier are performed alternately. This is the so-called intermittent printing method. The carrier contains a plurality of type elements and traverses back and forth along lines of the record media. On the other hand, in a second method, the hammering operation and the spacing operation are performed simultaneously. This is the so-called continuous printing method. That is, in the above mentioned first method, the carrier stops traversing every time it is located at the predetermined printing position and, then, the hammering operation follows; while, in the above mentioned second method, the hammering operation has commenced before the carrier reaches the predetermined printing position and, when the carrier reaches this printing position, the selected type on the carrier is impacted at the printing position on the record media. Therefore, the above mentioned second method is more suitable for employment in a high speed printing system than the above mentioned first method.
In a printing system employing either the first method or the second method the above-mentioned disadvantage arises when the single control mode is used to control the printing impact. As mentioned above, the disadvantage is that, although the energizing current is slightly varied, the intensity of the printing impact is widely varied, and as a result, fine control of the printing impact, and accordingly, fine control of the contrast appearing on the record media, can not be achieved. Furthermore, in a printing system employing the above mentioned second method the following disadvantage is created: the selected type element does not impact correctly at a predetermined printing position on the record media. This is because, although the energizing current is slightly varied, the flight time of the selected type element is widely varied.

High speed variable intensity printing system


An information recording medium comprises a semiconductor layer and a layer of a ferroelectric substance overlaid on the semiconductor layer, information being recorded by means of directions of polarization of the ferroelectric substance. The ferroelectric substance is an organic ferroelectric substance, such that recorded information may not be lost during its reproduction and a sufficiently high level of a reproduced signal may be obtained.

1. Field of the Invention
This invention relates to an information recording medium. This invention particularly relates to an information recording medium, which is provided with a layer of a ferroelectric substance and on which information is recorded by means of directions of polarization of the ferroelectric substance. This invention also relates to a method for recording information on the information recording medium.
2. Description of the Prior Art
As information recording media, on which various kinds of information, such as image signals and audio signals, are recorded or which are used as signal memories for computers, magnetic recording media, magneto-optical recording media, or the like, have heretofore been used widely.
Also, an information recording medium, on which the information can be recorded and erased, from which the information can be reproduced, and on which the information can be recorded at a high density, has been proposed in, for example, Japanese Unexamined Patent Publication No. 57(1982)-27447. The proposed information recording medium comprises a semiconductor layer and a layer of a ferroelectric substance overlaid on the semiconductor layer and records the information by means of directions of polarization of the ferroelectric substance. Recording of the information on the proposed information recording medium is carried out by moving an electroconductive head on the ferroelectric substance layer, and at the same time applying a voltage to the ferroelectric substance layer such that only predetermined portions of the ferroelectric substance layer may be selectively polarized in a predetermined direction. When the information is to be reproduced from the information recording medium, a change in the electrostatic capacity of the recording medium due to depletion layers, which are formed in the semiconductor layer by the polarization of the ferroelectric substance, is detected by an electroconductive head.
As the electroconductive head for reproduction, theoretically, a reproducing head, which is employed in a video disk system referred to as the VHD system, can be used. Specifically, with the video disk for the VHD system, the depletion layers described above are not formed, but a change in the electrostatic capacity is obtained from the presence or absence of pits. Therefore, the head for reproducing the recorded information is constituted so as to detect a change in the electrostatic capacity, which change occurs in accordance with the recorded information.
It is considered that a coercive field Ec serves as one of indexes for the stability of the information, which has been recorded by means of the directions of polarization of the ferroelectric substance. The stability of the information recorded on the information recording medium will hereinbelow be studied from the point of view of the coercive field Ec.
As for the conventional information recording medium disclosed in Japanese Unexamined Patent Publication No. 57(1982)-27447, the material which is considered for use as the ferroelectric substance is only lead titanate, which is an inorganic material. The coercive field Ec of the inorganic ferroelectric substance having a perovskite structure, such as lead titanate, is approximately on the order of several megavolts/m. In cases where the inorganic ferroelectric substance is used to record information at a high density, it is necessary for the thickness of the layer of the ferroelectric substance to be reduced to a value approximately equal to the recording spot length, e.g., to approximately 0.1 .mu.m. In such cases, the coercive field Ec can be converted to a voltage on the order of 0.1 V. Specifically, if a voltage higher than this order is applied to the ferroelectric substance layer, the recorded signal will disappear.
When a signal is reproduced from the information recording medium, in general, if the amplitude of a radio-frequency (RF) voltage, which is applied to the resonance circuit containing the information recording medium via the electroconductive head during the detection of the electrostatic capacity of the information recording medium, is lower than 1V, a reproduced signal will be obtained which has a markedly low S/N ratio and cannot be utilized practically. This is because the output power of the reproduced signal is proportional to the amplitude of the RF voltage. By way of example, in ordinary electrostatic capacity types of video disk systems, the amplitude of the RF voltage applied to the disk is set at approximately 4 V with the S/N ratio of the reproduced signal being taken into consideration.
As described above, even if the amplitude of the RF voltage applied to the information recording medium is set at the minimum value, i.e., approximately 1 V, such that the S/N ratio of the reproduced signal may not become markedly low, the setting value is much larger than 0.1 V, and therefore the information recorded on the information recording medium will be lost.
For the purposes of manufacturing an apparatus for reproducing the recorded information from the information recording medium of this type, it is desirable that the electroconductive head conventionally employed in the VHD system is utilized directly. However, with the conventional information recording medium in which depletion layers are formed, a degree of modulation .DELTA.C, i.e., the change in the electrostatic capacity caused to occur by the presence or absence of the depletion layers, is small, and therefore the conventional reproducing head cannot be utilized directly.
Also, the system for recording the information on the information recording medium by applying a voltage to the ferroelectric substance layer from the exterior in the manner described above, the problems occur in that, if the recording voltage is excessively high, the ferroelectric substance layer will suffer from dielectric breakdown, and the information recording medium will break. The intensity of the electric field, at which dielectric breakdown occurs, varies for different kinds of materials, structures, conditions, and the like, and is ordinarily approximately 1 MV/cm. The thickness of a recording layer of the information recording medium in accordance with the present invention is approximately 1 .mu.m or less. Therefore, in order for the information recording medium to be prevented from breaking due to dielectric breakdown, it is desirable that the voltage applied from the exterior during the recording step is kept at 100 V or less. However, such a recording method has not heretofore been developed.


A method of controlling the duration of local anesthesia and a reagent system or kit for inducing and limiting the duration of local anesthesia is described.

The present invention relates to anesthesia, especially local anesthetics. More particularly, this invention relates to a method for controlling the duration of local anesthesia, and to a reagent system or kit for inducing and limiting or reversing local anesthesia produced.
Anesthetic agents are pharmacologically active agents that block nerve conduction when applied in therapeutically effective amounts. They can be used for local application, namely to a localized area, for example, by application to the skin or other dermal membrane, or for systemic application, e.g., by the intraperitoneal or intravenous routes of administration.
The anesthetic agent may be applied locally by injection, ointments, jellies, topical solutions and suspensions or other forms known for topical administration.
Local anesthetics generally are esters or amides of benzoic acid, typically administered as an acid addition salt in dosages known to those skilled in the art.
For example, as applied to the region of the mouth and adjacent areas of humans, anesthesia involves injection of anesthetic agents including roughly 2 to 3% lidocaine, 2 to 3% mepivacaine, 0.5% marcaine or 3 to 4% prilocaine, usually administered in aqueous solution in the form of a water-soluble acid-addition salt, typically the hydrochloride salt. Also, as practiced, vasoconstricting agents such as epinephrine, phenylphrine or levonordenphedrine may be administered concomitantly or separately with the local anesthetic agent in order to prolong the duration of the local anesthesia, reportedly by constriction of blood vessels, resulting in prolongation of the contact of the anesthetic with the nerve.
Aqueous Lidocaine hydrochloride in sodium bicarbonate has been used in spinal and epidural anesthesia to speed up the onset of anesthesia to reduce the burning upon injection and to lengthen the duration of action.
In some areas, especially in the mouth, the local anesthesia may last longer than needed. This is debilitating and restrictive to the patient's normal activity. The administration of a local anesthetic at relatively low pH, typically in the range of about pH 2 to about pH 5.5, has been reported to retard the duration of anesthetic action.

Method of reversing local anesthesia and reagent system therefor


A pole-cleaning device sleeve having a pole-like member with a proximal end, a distal end, opposite to the proximal end, and a length separating the distal and proximal ends, the pole-like member having a head portion defining a working surface and being coupled to the distal end of the pole-like member, the pole-cleaning device also having a removably couplable sleeve with a distal end substantially adjacent to the head portion, a proximal end terminating at a location along the pole-like member length, and a sleeve length separating the distal and proximal ends, an outer layer being of a substantially deformably-resilient and polymer-based material, an inner layer coupled to the outer layer and contacting an outer surface of the pole-like member, and the outer and inner layers encapsulating at least a portion of the pole-like member.

It is well known that with the purchase of any transportation vehicle comes the added expense to the owner or operator of maintaining that vehicle. This principle is noticeably applicable with respect to marine vessels. Maintenance includes cleaning, resurfacing, or conditioning the outside exterior of the marine vessel generally with a cleaning device having an elongated pole that includes an end opposite to a handle portion of the pole that does the cleaning. Although cleaning devices are primarily used in connection with maintenance of marine vessels and other vehicles, other known devices employ the same structural features used to maintain the exterior/interior of the marine vessel, e.g., paint brushes.
Cleaning and maintaining the exterior surface of the marine vessel, specifically washing or painting, is problematic for many users because of the size or cumbersome shape of most marine vessels. It is estimated that a dirty hull of a marine vessel can increase fuels costs up to about 30%. As such, the user is required to reach or extend the pole over larger surfaces to effectuate proper cleaning or maintenance of the marine vessel. In many instances, the use of the cleaning device results in damage to the boat because the user is often unbalanced or unstable. As the cost to repair most damage to a marine vessel is actually more than the cleaning or maintenance itself, preventing any damage to the marine vessel is very important for users. Also problematic for many users is when the cleaning device becomes dislodged from the user and falls into a body of water, causing the cleaning device to sink to the bottom thereof. As many marine vessels are docked in large bodies of water, retrieving the cleaning device becomes difficult if not impossible. As most of these cleaning devices are also costly to purchase, preserving the life of the cleaning device is also desired.
Most known cleaning devices consist of a metallic or rigid pole with a head located at the distal end of the pole. The head typically has a brush, bristles, or other protuberances coupled thereto. Some known cleaning devices place a raised surface, made typically of rubber, around the perimeter of the head to prevent damage, should the head contact the cleaning or contact surface of the vessel. These "cushioned" heads, however, do not prevent damage on the marine vessel from the pole of the cleaning device. As there are many portions on a marine vessel that require a user to navigate the pole around or across in order to reach a desired cleaning location, the pole tends to contact the surfaces or objects of the vessel. The consequences of this contact are dents, scratches, and other deformations or visual indications of a hard surface contacting a wood, fiberglass, or composite structure. These cushioned heads also do not inhibit the cleaning device from sinking in a usually less dense body of water.
Some other known cleaning devices include rubber grips located at the handle portion of the cleaning device. These devices, however, suffer from many of the above-described deficiencies. Chiefly, they do not provide protection at the head or distal end of the pole, where typically most of the contact occurs. Also, most, if not all, of these devices do not permit the rubber portion from being easily removed from the pole. As such, the user is limited to purchasing an entirely new cleaning device should the rubber portion become damaged. A user is also unable to retrofit pre-existing cleaning devices with protection. Furthermore, because many of these cleaning devices often require the head portion to be extended through use of the pole, most if not all known cleaning devices do not have the ability to protect the marine vessel from contact with the pole when the pole is extended. These cleaning devices also do not prevent a cleaning device from sinking in a body of water.
Therefore, a need exists to overcome the problems with the prior art as discussed above.


A fixing device includes: a fixing belt of an endless shape wound to pass over a heating-side member and a nip forming member; and a pressing roller driven to rotate in a state of being brought into tight contact with the nip forming member through the fixing belt, wherein a toner image is fixed to a recording medium at a nip portion at which the fixing belt and the pressing roller are brought into tight contact with each other by causing the pressing roller to be in tight contact with the fixing belt and driving the pressing roller to rotate, a guide member guiding the fixing belt to a space between the nip forming member and the heating-side member is disposed to be separate from the nip forming member, and a sliding member is disposed at least in a contact portion between the nip forming member and the fixing belt.

Technological Field
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and a multi-function apparatus thereof and a fixing device that fixes a toner image formed on a recording medium to the recording medium in such an image forming apparatus. Particularly, in a fixing device including an endless fixing belt that is wound to pass over a heating-side member and a nip forming member and a pressing roller that is driven to rotate in the state of being brought into tight contact with the nip forming member through the fixing belt and fixing a toner image to a recording medium in a nip portion at which the fixing belt and the pressing roller are brought into tight contact with each other by causing the pressing roller to be in tight contact with the fixing belt and driving the pressing roller to rotate, there is a feature in that the fixing belt is stably rotated in the state of being in tight contact with the nip forming member by decreasing frictional resistance between the fixing belt and the nip forming member by employing a simple configuration.
Description of the Related Art
Generally, in an image forming apparatus such as a copying machine, a printer, a facsimile, or a multi-function apparatus thereof, a toner image transferred onto a recording medium is fixed onto the recording medium by using a fixing device.
In such a fixing device, in fixing a toner image transferred to a recording medium to a sheet by using heat and pressure, in order to save energy, an endless fixing belt is wound to pass over a heating roller and a heating-side roller, the pressing roller is driven to rotate in the state of being in tight contact with the heating-side roller through the fixing belt, and the toner image is fixed to a recording medium at a nip portion at which the fixing belt and the pressing roller are tightly brought into contact with each other.
In addition, in recent years, in order to further save energy, for example, as disclosed in JP 2008-46663 A, it is proposed that, instead of the heating-side roller described above, by using a fixing member, in which a heat-resistant elastic member is disposed at a portion at which a nip is formed by causing the pressing roller to be in tight contact therein, that does not rotate, the fixing belt described above is wound to pass over a heating roller and the fixing member, and, by causing the pressing roller that is driven to rotate to be in tight contact with the heat-resistant elastic member through the fixing belt, the fixing belt is driven to rotate together with the pressing roller, and, in a nip portion at which the fixing belt and the pressing roller are brought into tight contact with each other, a toner image is fixed to a recording medium.
However, in the technology disclosed in JP 2008-46663 A, sliding resistance is generated according to friction between the heat-resistant elastic member of the fixing member and the fixing belt, and the rotation of the fixing belt becomes unstable, whereby there is a problem of the presence of an adverse effect on a formed image and the like.
In addition, as disclosed in JP 2003-337481 A, a fixing device fixing an unfixed image on a recording material is known. When devices configuring an image forming apparatus are compared with each other, the power consumption of the fixing device is relatively high. In order to decrease the power consumption of the image forming apparatus, it is effective to decrease the power consumption of the fixing device.
The fixing device fixes an unfixed image through pressurization and heating. As one of techniques for decreasing the power consumption of the fixing device, it is considered to lower the fixing temperature. In a case where the fixing temperature is set to be low, in order to suppress the degradation of the image quality (fixing quality), it is necessary to employ some countermeasure.
For example, in a case where same toner is used, by increasing the load at the fixing nip or increasing a nip time, the influence according to the lowering of the fixing temperature can be decreased. Also in a case where the fixing temperature is lowered, by employing such a countermeasure, degradation of the fixing quality can be suppressed, and furthermore, the power consumption of the fixing device can be decreased.

Fixing device having an endless belt and guide member and image forming apparatus


A coating process for the fabrication of organic photoreceptors employs an electrically conductive single slot die biased to allow an electric field between the die and the ground plane on the photoreceptor substrate. The homogenous coating dispersion is fed through the die at a predetermined gap and rate to control coating thickness at the same time that an electric field is applied. The formulation, rheology, particle mobility, coating speed, electric field and the like are controlled so that the photogenerator particles migrate to the substrate in the dwell time defined by the coating die region.

1. Field of Invention
This invention generally relates to a process for applying a coating material to a surface of a substrate. More particularly, this invention relates to a process for applying a charge generating material to a photoreceptor substrate, and to photoreceptors made by such a process.
2. Description of Related Art
Among the many conventional methods of coating a substrate with a coating material is the use of an extrusion or slot die from which the coating material is extruded onto the substrate. Using such slot coating of thin layers, the window of operating parameters is extremely small and is affected by factors such as the coating thickness, the speed of the substrate, the theological properties of the coating liquids, the vacuum pressure, the relative speed of the extruded coating material, the amount of pressure applied to the coating material as it progresses through the extrusion slot, etc.
Extrusion coating methods for forming thin layers are described in U.S. Pat. Nos. 4,521,457 and 5,614,260, the entire disclosures of which are totally incorporated herein by reference.
Such extrusion coating methods have conventionally been used to manufacture Xerographic photoreceptors. Xerographic photoreceptors are typically prepared using either a single layer configuration or a multilayer configuration. The multilayer arrangement is more common. In the multilayer configuration, the active layers are the charge generation layer (CGL) and the charge transport layer (CTL). Charge generation layers are usually prepared as dispersions of pigment particles in a polymer host. Most charge generation layers conventionally range from between 0.1 and 5 microns in dry thickness. In contrast, transport layers conventionally range from about 20 to 29 microns thick. In the multilayer configurement, additional layers, such as blocking, adhesion, overcoat and undercoard layers may optionally be included as desired.
Generally, each of the charge generation and charge transport layers is applied separately onto a substrate. The charge generation layer is typically coated onto a blocking layer, under which there can be an undercoat layer for providing adhesion and optionally a blocking function over the substrate. Then, the charge transport layer is typically coated over the charge generation layer.
The use of conventional extrusion slot die methods of forming thin coatings of dispersions of photoconductive particles can produce defects resembling brush marks along each edge of the deposited coating. These brush marks can remain as defects in the dried coating and can ultimately print out as undesirable artifacts in the final electrophotographic copy.
The coating materials for charge generation layers of photoreceptors can be Newtonian but are often made of Non-Newtonian dispersions, which show shear thinning, thixotropic and yield stress behaviors. The dispersion shows little or no deformation up to the yield stress, which can lead to flocculation of dispersion particles in the coated film.
U.S. Pat. No. 5,531,872 to Forgit et al., the entire disclosure of which is incorporated herein by reference, discloses a static process for fabricating a photoconductive member including depositing a photoconductive material, such as a charge generating material, and a charge transport material on a substrate, sequentially in any order, or simultaneously. The photoconductive material, the charge transport material, or both, are electrophoretically deposited onto the substrate from a liquid composition using a voltage of from 8 to 60 volts to create an electric field. The electrophoretic deposition is accomplished by maintaining the electric field for up to five minutes.


An electrostatic latent image developing toner includes a plurality of toner particles (10) each including a toner mother particle (11) and an external additive adhering to a surface of the toner mother particle (11). The toner mother particles (11) contain a crystalline polyester resin and a non-crystalline polyester resin. The toner particles (10) include, as the external additive, crystal nucleating agent particles (13) containing a crystal nucleating agent for promoting crystallization of the crystalline polyester resin. On a differential scanning calorimetry spectrum of the toner before fixing, an endotherm quantity of a heat absorption peak originating from a crystalline region of the crystalline polyester resin is less than 2.0 mJ/mg. On a differential scanning calorimetry spectrum of the toner after fixing, an endotherm quantity of a heat absorption peak originating from a crystalline region of the crystalline polyester resin is at least 6.0 mJ/mg.

A method for manufacturing a capsule toner described in Patent Literature 1 includes a mixed resin fine particle attaching step, a spraying step, and a filming step. In the mixed resin fine particle attaching step, particles having mixed resin fine particles adhering thereto are obtained by causing mixed resin fine particles including crystalline polyester resin fine particles and non-crystalline resin fine particles to adhere to surfaces of toner mother particles. In the spraying step, a mixed solution is sprayed to the particles having the mixed resin fine particles adhering thereto in a flowable state. The mixed solution includes a crystal nucleating agent and a liquid for plasticizing the particles having the mixed resin fine particles adhering thereto. In the filming step, a resin coat layer is formed on the surface of each toner mother particle by processing the mixed resin fine particles into a film using impact force.

Electrostatic latent image developing toner


Disclosed are formulations which are designed to delay release of rasagiline while maintaining specific pharmacokinetic properties.

U.S. Pat. Nos. 5,532,415, 5,387,612, 5,453,446, 5,457,133, 5,599,991, 5,744,500, 5,891,923, 5,668,181, 5,576,353, 5,519,061, 5,786,390, 6,316,504, 6,630,514 disclose R(+)-N-propargyl-1-aminoindan ("R-PAI"), also known as rasagiline. Rasagiline has been reported to be a selective inhibitor of the B-form of the enzyme monoamine oxidase ("MAO-B") and is useful in treating Parkinson's disease and various other conditions by inhibition of MAO-B in the brain.
U.S. Pat. No. 6,126,968 and PCT International Application Publication No. WO 95/11016 disclose pharmaceutical formulations comprising rasagiline. PCT International Application Publication No. WO 2006/014973 also discloses pharmaceutical formulations comprising rasagiline.
AZILECT® is a commercially available rasagiline mesylate immediate release formulation indicated for the treatment of the signs and symptoms of idiopathic Parkinson's disease as initial monotherapy and as adjunct therapy to levodopa. The current marketed formulation of rasagiline (Azilect®) is rapidly absorbed, reaching peak plasma concentration (tmax) in approximately 1 hour. The absolute bioavailability of rasagiline is about 36%. (AZILECT® Product Label, May 2006).

This patent is subject to a terminal disclaimer.

Delayed release rasagiline citrate formulation