An arrayed waveguide grating optical multiplexer/demultiplexer includes an arrayed waveguide connected to at least one first optical waveguide via a first slab waveguide, a plurality of second optical waveguides connected to the arrayed waveguide via a second slab waveguide. At least one expanding width waveguide has a first end portion and a second end portion having a second width larger than a first width of the first end portion. Each first end portion is connected to each first optical waveguide. The second end portion is connected to the first slab waveguide. The first width of the first end portion is larger than a first optical waveguide width of the at least one first optical waveguide. The first width of the first end portion satisfies a single mode condition. A width of the expanding width waveguide increases from the first end portion toward the second end portion.

1. Field of the Invention
The present invention relates to an arrayed waveguide grating optical multiplexer/demultiplexer and an expanding width waveguide.
2. Discussion of the Background
In recent optical communications, research and development of optical wavelength division multiplexing communications has actively been made as a way to exponentially increase the transmission volume, and the results are being put into practice. The optical wavelength division multiplexing communications uses, for example, a technique of wavelength division multiplexing on a plurality of light beams each having a wavelength different from one another to transmit them. In the system of such optical wavelength division multiplexing communications, an optical multiplexer/demultiplexer is necessary which multiplexes a plurality of light beams each having a wavelength different from one another and which demultiplexes light that has undergone wavelength division multiplexing to be transmitted to create a plurality of light beams each having a wavelength different from one another.
FIG. 18(a) illustrates an arrayed waveguide grating (AWG) type optical multiplexer/demultiplexer. Referring to FIG. 18(a), the arrayed waveguide grating type optical multiplexer/demultiplexer is obtained by forming on a substrate 11 an optical waveguide unit 10 that has a waveguide structure.
The waveguide structure includes at least one optical input waveguide 12 arranged side by side, a first slab waveguide 13 connected to the exit ends of the optical input waveguides 12, an arrayed waveguide 14 connected to the exit end of the first slab waveguide 13, a second slab waveguide 15 connected to the exit end of the arrayed waveguide 14, and a plurality of optical output waveguides 16 that are arranged side by side and connected to the exit end of the second slab waveguide 15.
The arrayed waveguide 14 propagates light that is outputted from the first slab waveguide 13, and is composed of a plurality of channel waveguides (14a) that are arranged side by side. Lengths of adjacent channel waveguides (14a) are different from each other by a predetermined length difference (xcex94L). The optical input waveguides 12 and the optical output waveguides 16 have the same dimension.
The number of optical output waveguides 16 is determined, for example, in accordance with the number of light beams which have different wavelengths and which are created by demultiplexing signal light with the arrayed waveguide grating type optical multiplexer/demultiplexer. The arrayed waveguide 14 usually includes a large number (for example, 100) of the channel waveguides (14a). However, FIG. 18(a) is simplified and the number of the channel waveguides (14a), the optical output waveguides 16, and the optical input waveguides 12 in FIG. 18(a) does not exactly reflect the actual number thereof.
FIG. 18(b) schematically shows an enlarged view of an area of FIG. 18(a) which is surrounded by a dotted line (A). As shown in FIG. 18(b), in the arrayed waveguide grating type optical multiplexer/demultiplexer in the background art, the substantially straight portion (12a) which is connected to an end portion of the slightly curved portion (12b) of the optical input waveguides 12 is directly connected to the entrance end of the first slab waveguide 13. Similarly, the substantially straight portion which is connected to an end portion of the slightly curved portion of the optical output waveguides 16 is directly connected to the exit end of the second slab waveguide 15.
One of the optical input waveguides 12 is connected to, for example, transmission side optical fiber, so that light having undergone the wavelength division multiplexing is introduced to one of the optical input waveguides 12. The light which has traveled through one of the optical input waveguides 12 and been introduced to the first slab waveguide 13 is diffracted by the diffraction effect thereof and enters the arrayed waveguide 14 to travel along the arrayed waveguide 14.
Having traveled through the arrayed waveguide 14, the light reaches the second slab waveguide 15 and then is condensed in the optical output waveguides 16 to be outputted therefrom. Because of the preset difference in length between adjacent channel waveguides (14a) of the arrayed waveguide 14, light beams after traveling through the arrayed waveguide 14 have phases different from one another. The wavefront of the light beam is tilted in accordance with this difference and each position where each light beam is condensed is determined by the angle of this tilt. Therefore, the light beams having different wavelengths are condensed at positions different from one another. By forming the optical output waveguides 16 at these positions, the light beams having different wavelengths can be outputted from their respective optical output waveguides 16 that are provided for the respective wavelengths.
For instance, as shown in FIG. 18(a), the light having undergone the wavelength division multiplexing and having wavelengths of xcex1, xcex2, xcex3, . . . , xcexn (n is an integer equal to or larger than 2), is inputted from one of the optical input waveguides 12. The light is diffracted in the first slab waveguide 13, reach the arrayed waveguide 14, and travel through the arrayed waveguide 14 and the second slab waveguide 15. Then, as described above, the light beams are respectively condensed at different positions determined by their wavelengths, enter different optical output waveguides 16, travel along their respective optical output waveguides 16, and are outputted from the exit ends of the respective optical output waveguides 16. The light beams having different wavelengths are taken out through optical fibers that are connected to the exit ends of the optical output waveguides 16.
In this arrayed waveguide grating type optical multiplexer/demultiplexer, improvement in wavelength resolution is in proportion to the difference in length (xcex94L) between the channel waveguides (14a) of the arrayed waveguide 14. When the optical multiplexer/demultiplexer is designed to have a large (xcex94L), it is possible to multiplex/demultiplex light to accomplish wavelength division multiplexing with small wavelength differences, which has not been attained by any conventional optical multiplexer/demultiplexer. It is thus possible for the optical multiplexer/demultiplexer to have a function of multiplexing/demultiplexing a plurality of signal light beams, specifically a function of demultiplexing or multiplexing a plurality of optical signals with a wavelength difference of at most 1 nm. High density optical wavelength division multiplexing communications require such a small wavelength difference.
The arrayed waveguide grating type optical multiplexer/demultiplexer is obtained by, for example, forming a waveguide formation region 10 having the above waveguide structure on a substrate 11 made of silicon (Si) as follows:
That is, an under cladding layer (SiO2 based glass) and a core layer (for example, glass mainly containing SiO2 to which GeO2 is added) are formed on the substrate 11 by flame hydrolysis deposition method, and the above waveguide structure is formed by, for example, photolithography and reactive ion etching method. Subsequently, the over cladding layer that covers the waveguide structure of the core is formed by flame hydrolysis deposition method.
Japanese Unexamined Patent Publication (Kokai) No. Hei 5-313029 discloses an arrayed waveguide grating type multiplexer/demultiplexer. The contents of this reference are incorporated herein by reference in their entirety. In this multiplexer/demultiplexer, optical input waveguides are connected to an inputside slab waveguide via a tapered waveguide.
Japanese Unexamined Patent Publication (Kokai) No. Hei 8-122557 discloses an arrayed waveguide grating type multiplexer/demultiplexer. The contents of this reference are incorporated herein by reference in their entirety. In this multiplexer/demultiplexer, an optical input waveguide is connected to an inputside slab waveguide via a tapered waveguide which has a slit along a center axis of the tapered waveguide.
Japanese Unexamined Patent Publication (Kokai) No. Hei 9-297228 discloses an arrayed waveguide grating. The contents of this reference are incorporated herein by reference in their entirety. In this arrayed waveguide grating, optical input waveguides are connected to an inputside slab waveguide via a parabolic waveguide.
According to an aspect of the present invention, an arrayed waveguide grating optical multiplexer/demultiplexer includes at least one first optical waveguide, a first slab waveguide, an arrayed waveguide, a second slab waveguide, a plurality of second optical waveguides, and at least one expanding width waveguide. The arrayed waveguide is connected to the at least one first optical waveguide via the first slab waveguide. The arrayed waveguide includes a plurality of channel waveguides each of which has a different length. The plurality of second optical waveguides are connected to the arrayed waveguide via the second slab waveguide. The at least one expanding width waveguide has a first end portion and a second end portion having a second width larger than a first width of the first end portion. The first end portion of each of the at least one expanding width waveguide is connected to each of the at least one first optical waveguide. The second end portion is connected to the first slab waveguide. The first width of the first end portion is larger than a first optical waveguide width of the at least one first optical waveguide. The first width of the first end portion satisfies a single mode condition. A width of the at least one expanding width waveguide increases from the first end portion toward the second end portion.
According to another aspect of the present invention, an arrayed waveguide grating optical multiplexer/demultiplexer includes at least one first optical waveguide, a first slab waveguide, an arrayed waveguide, a second slab waveguide, a plurality of second optical waveguides, and a plurality of expanding width waveguides. The arrayed waveguide is connected to the at least one first optical waveguide via the first slab waveguide. The arrayed waveguide includes a plurality of channel waveguides each of which has a different length. The plurality of second optical waveguides are connected to the arrayed waveguide via the second slab waveguide. Each of the plurality of expanding width waveguides has a third end portion and a fourth end portion having a fourth width larger than a third width of the third end portion. The third end portion of each of the plurality of expanding width waveguides is connected to each of the plurality of second optical waveguides. The fourth end portion is connected to the second slab waveguide. The third width of the third end portion is larger than a second optical waveguide width of each of the plurality of second optical waveguides. The third width of the third end portion satisfies a single mode condition. A width of the expanding width waveguide increases from the third end portion toward the fourth end portion.
According to yet another aspect of the present invention, an arrayed waveguide grating optical multiplexer/demultiplexer includes at least one first optical waveguide, a first slab waveguide, an arrayed waveguide, a second slab waveguide, a plurality of second optical waveguides, at least one first expanding width waveguide and a plurality of second expanding width waveguides. The arrayed waveguide is connected to the at least one first optical waveguide via the first slab waveguide. The arrayed waveguide includes a plurality of channel waveguides each of which has a different length. The plurality of second optical waveguides are connected to the arrayed waveguide via the second slab waveguide. The at least one first expanding width waveguide has a first end portion and a second end portion. The second width of the second end portion is larger than a first width of the first end portion. The first end portion of each of the at least one first expanding width waveguide is connected to each of the at least one first optical waveguide. The second end portion is connected to the first slab waveguide. The first width of the first end portion is larger than a first optical waveguide width of the at least one first optical waveguide. The first width of the first end portion satisfies a single mode condition. A width of the at least one first expanding width waveguide increases from the first end portion toward the second end portion. Each of the plurality of second expanding width waveguides has a third end portion and a fourth end portion. A fourth width of the fourth end portion is larger than a third width of the third end portion. The third end portion of each of the plurality of second expanding width waveguides is connected to each of the plurality of second optical waveguides. The fourth end portion is connected to the second slab waveguide. The third width of the third end portion is larger than a second optical waveguide width of each of the plurality of second optical waveguides. The third width of the third end portion satisfies a single mode condition. A width of the second expanding width waveguide increases from the third end portion toward the fourth end portion.
According to further aspect of the present invention, an expanding width waveguide includes a first end portion and a second end portion having a second width larger than a first width of the first end portion. The first end portion is configured to be connected to at least one first optical waveguide. The second end portion is configured to be connected to the first slab waveguide. The first width of the first end portion is larger than a first optical waveguide width of the at least one first optical waveguide. The first width of the first end portion satisfies a single mode condition. A width of the expanding width waveguide increases from the first end portion toward the second end portion.
According to further aspect of the present invention, an optical waveguide circuit includes an expanding width waveguide. The expanding width waveguide includes a first end portion which has a first width and which is configured to be connected to a single mode waveguide. The first width is larger than a waveguide width of the single mode waveguide and satisfies a single mode condition. Further, the expanding width waveguide includes a second end portion which has a second width larger than the first width of the first end portion. A width of the expanding width waveguide increases from the first end portion toward the second end portion.

Arrayed waveguide grating type optical multiplexer/demultiplexer


A process for preparing a laminate by coating the surfaces of a metal substrate that has been treated with an anchor coating agent, with a modified olefin type resin and heat-adhering the olefin resin onto the surfaces of the metal substrate. The process of this invention is characterized by applying heat-treatment to the laminate at the time of adhesion or after the adhesion in the presence of a treating agent which consists of a compound prescribed in the general formulae (1) and (2). ##STR1## The laminate prepared by this process withstands deterioration of adhesion caused by aging, particularly in an atmosphere where water is present.

1. Field of the Invention
The present invention relates to a process for preparing a laminate of a metal and a polyolefin resin. More specifically, the invention relates to a process for preparing a laminate which excellently withstands against the deterioration of adhesion caused by aging.
2. Description of the Related Art
The surfaces of metals have heretofore been coated with a resin to protect them from corrosion, fouling and damage. For instance, a transition joint that is used for the insert molding is subjected to severe environment in which it is brought into contact with molten resins. Therefore, its metallic threaded portions must be coated with a resin. A variety of resins for coating use are suitably selected depending upon the applications and the cost required.
The coating with resin is not limited to the above applications only but is widely employed in such fields as various parts and structural members made of metals, such as commodities, packaging materials, various panels, interior finish members, various casings, etc.
The polyolefin resin can be used for general purposes exhibiting such advantages as easy melt-adhesion upon heating, resistance against water, resistance against humidity, and excellent sanitary properties, and is further, available relatively cheaply. Because of its poor polarity, however, the polyolefin resin is adhered to metals only poorly and peels off easily from the metal after it is once adhered.
In order to improve this defect, an anchor coating agent of organotitanium or the like is applied in advance to the surface of the metal which is to be coated with the polyolefin resin, and then the polyolefin type resin is heat-adhered via the anchor coating agent, as is widely known.
Moreover, it has heretofore been known to improve the adhesiveness by introducing a polar group into the polyolefin resin, and to graft-modify the polyolefin resin with an unsaturated carboxylic acid or an anhydride thereof such as a maleic anhydride in order to apply and heat-adhere it onto the surface of the metal substrate. For instance, according to Japanese Patent Publication No. 10184/1981, a polyolefin grafted with an unsaturated carboxylic acid or an anhydride thereof is heat-adhered to a metal fitting via an organosilicon compound that has a hydroxyl group or a hydrolyzable group and an acid-reactive group and that is disposed on an interface between the two. Moreover, Japanese Patent Publication No. 12299/1983 discloses a composition consisting of 70 to 95 parts by weight of an acid-modified polyethylene and 5 to 30 parts by weight of a polypropylene, which is laminated on a metal, and Japanese Patent Publication No. 40491/1983 discloses a composition consisting of 99 to 70 parts by weight of an acid-modified polyolefin and 1 to 30 parts by weight of a hydrocarbon-type elastomer, that is used as an adhesive agent for laminating a polyolefin on a metal foil.
In fact, however, though the laminate of a polyolefin type resin and a metal substrate exhibits a high adhesion strength during the initial period, the adhesion strength decreases with the lapse of time almost without exception. This tendency appears conspicuously in an environment where water is present. For instance, the aforementioned acid-modified polyolefin resin exhibits a considerably great initial adhesion strength for metals but loses adhesive force drastically with the lapse of time in an environment where water exists. The tendency of adhesion deterioration is also recognized even when the surface of the metal is treated with an anchor coating agent such as organotitanate prior to effecting the adhesion.
In preparing a laminate by coating a metal substrate with a polyolefin resin and heat-adhering it thereon, therefore, it is an object of the present invention to provide a treatment method which prevents the adhesion strength between the metal substrate and the polyolefin resin from decreasing with the lapse of time and, particularly, which prevents the adhesion strength from decreasing in an environment where water exists.
Another object of the present invention is to provide a method of effecting the treatment for preventing the adhesion strength from decreasing with the lapse of time in a simple and easy manner at a relatively low cost.

Process for preparing a laminate of metal and a polyolefin resin


A variable valve lift apparatus may include a camshaft, a cam lobe including at least one low lift cam and at least one high lift cam, and formed or mounted on an exterior circumference of the camshaft, and a cam follower opening a valve with a low lift or a high lift or closing the valve by a rotation of the camshaft. The cam follower may include a valve lift body pivoting on one side and opening or closing the valve by the cam lobe when the camshaft rotates, a bearing shaft fixedly mounted in the valve lift body, and at least one rolling bearing rotatably mounted on the bearing shaft and being movable axially on the bearing shaft to make contact selectively with the low lift cam or the high lift cam.

1. Field of Invention
The present invention relates to a variable valve lift apparatus, and more particularly, to the variable valve lift apparatus that can achieve the improvement of fuel consumption, rapid and accurate control of valve lift change, weight and cost reduction, and the improvement of dynamic characteristic and durability of valves.
2. Description of Related Art
In general, variable valve lift technology is being researched to improve driving performance and fuel consumption by changing the size of the valve lift according to the driving conditions of an engine.
FIG. 1 through FIG. 3 are drawings which show the structure and the operational principle of a variable valve lift apparatus according to a prior art. FIG. 1 is a perspective view of a cam follower of a variable valve lift apparatus according to a prior art. FIG. 2 is a cross-sectional view along a line I-I of FIG. 1 for explaining the operational principle of a variable valve lift apparatus according to a prior art.
Referring to FIG. 1 and FIG. 2, the cam follower comprises a lost lever 1, a locking pin 2, an inner arm 3, a lost motion spring 4, and a hinging pin 5. The lost lever 1 includes two lost lever pads 6. The lost lever 1 is the external body of the cam follower. By driving force through the rotation of a high lift cam moves the lost lever 1, which is mounted at the outside of the inner arm 3 and connected with the inner arm 3 by the hinging pin 5.
The inner arm 3 includes a bearing shaft and a roller 7. The inner arm 3 is the internal body of the cam follower. Inside the inner arm 3 is the locking pin 2 installed, which can be moved forward by hydraulic lash adjuster 8. The lost motion spring 4 is fixedly mounted between fixing plates of the lost lever 1 and the inner arm 3 and functions as an actuator making the lost lever 1 return to its original position after its motion relative to the inner arm 3.
Hereinafter, the principle of low lift and high lift operation of a variable valve lift apparatus according to a prior art will be explained.
Firstly, the principle of low lift valve operation of the variable valve lift apparatus is as follows.
The roller 7 is generally a rolling bearing and has the function of delivering the driving force through the rotation of a low lift cam to the inner arm 3 through bearing, shaft fixedly installed in the inner arm 3 by making rolling contact with the low lift cam. At the moment, the driving force through the rotation of the low lift cam acts on the roller 7 with a contact portion of the inner arm 3 and the hydraulic lash adjuster 8 functioning as an axis of rotation and thereby the hinging pin 5 descends.
Therefore, in case the low lift cam makes rolling contact with the roller 7, the driving force through the rotation of the low lift cam is delivered to a valve stem 9 connected with the hinging pin 5 of the inner arm 3 and thereby a valve operates in low lift. In this case, a high lift cam spins the lost lever 1 with no effect on a valve. This motion of the lost lever 1 is called lost motion.
The operational principle of the lost motion of the lost lever 1 will be described below. The lost lever pad 6 is not a rolling bearing and is a portion making friction contact with the high lift cam. It has the function of delivering the driving force through the rotation of the high lift cam to the lost lever 1 and making the lost lever 1 rotate on the hinging pin 5. The rotation is the motion relative to the inner arm 3.
If the driving force through the rotation of the high lift cams is applied to the lost lever pads 6 with the locking pin 2 received inside the inner arm 3, the rotation of the lost lever 1 becomes lost motion. That is to say, the rotating motion applies no force to the cam follower and the lost lever 1 comes back to its original position by the elastic force of the lost motion spring 4 (Refer to FIG. 2). In this case, only the driving force through the rotation of the low lift cam is applied to the hinging pin 5 through the roller 7 and thereby a valve operates in low lift.
Next, the principle of high lift valve operation of the variable valve lift apparatus is as follows.
In case the locking pin 2 is moved forward with the increase of the hydraulic pressure by the operation of the hydraulic lash adjuster 8, the rotating motion of the lost lever 1 is locked by the locking pin 2. At this moment, the hinging pin 5 rotates down on a contact portion of the hydraulic lash adjuster 8 by the driving force through the rotation of the high lift cam being applied to the lost lever pads 6. Accordingly, a valve operates in high lift through the valve stem 9 connected with the hinging pin 5.
FIG. 3 is a drawing which compares the principles of low lift valve operation and high lift valve operation of a variable valve lift apparatus according to a prior art. Referring to FIG. 3, foregoing explanations will be organized hereinafter.
In case hydraulic pressure of the hydraulic lash adjuster 8 is lower than the load of a spring supporting the locking pin 2, a variable valve lift apparatus operates in low lift condition. In this case, the rotating motion of the lost lever 1 by a high lift cam becomes lost motion.
This is because the lost lever 1 operates in a state of being unlocked with the locking pin 2 received inside the inner arm 3 on account of the locking pin 2 being supported by the spring. In other words, the high lift cam spins with no effect on a valve while the low lift cam makes rolling contact with the roller 7 and thereby the valve operates in low lift.
In case hydraulic pressure of the hydraulic lash adjuster 8 is higher than the load of the spring supporting the locking pin 2, a variable valve lift apparatus operates in high lift condition. In this case, the locking pin 2 moves forward and protrudes from the inner arm 3 by overcoming the load of the spring through higher hydraulic pressure.
Accordingly, the lost lever 1 becomes in locked condition, the driving force through the rotation of the high lift cams acts on the lost lever pads 6 with a contact portion of the hydraulic lash adjuster 8 functioning as a pivot, and thereby the hinging pin 5 descends and a valve operates in high lift. At this moment, the low lift cam and the roller 7 don't make contact with each other in principle as FIG. 3 shows.
This is because the high lift cams make contact with the lost lever pads 6 on the point of the low lift cam making contact with the roller 7 and the inner arm 3 descends in high lift condition.
The problems of the prior art includes at least the followings.
In high lift condition, the valve lift operation is carried out not through a rolling bearing but through the lost lever pads 6. As a result, friction loss is large, abrasion happens, and thereby durability of a variable valve lift apparatus is deteriorated.
In low lift condition as well as high lift condition, two high lift cams always make friction contact with the lost lever pads 6. Therefore, friction loss continues while valves keep opening or closing.
In the meantime, even in high lift condition the contact of the low lift cam and the roller 7 may actually happen and thereby the gap between the high lift cams and the lost lever pads 6 may happen.
This is because even though machining is executed so precisely it's almost impossible for the high lift cams and the low lift cam to simultaneously come into contact with the lost lever pads 6 and the roller 7 respectively. This kind of phenomenon may result from defects of machining precision and vibrations of the variable valve lift apparatus, etc.
In case the gap is formed, lift loss happens in high lift condition, impulsive load acts on the valve apparatus, and thereby durability may be deteriorated. In addition, the structure and the shape of a variable valve lift apparatus according to a prior art are complicated and there are lots of parts in it. This becomes the cause of rise of manufacturing cost and exerts a bad effect on dynamic characteristic and durability of the variable valve lift apparatus.
A variable valve lift apparatus according to a prior art operates through oil pressure of oil gallery by controlling an oil control valve (OCV). On this account, the variable valve lift apparatus is sensitive to oil temperature and pressure and an unnecessary demand for increasing a capacity of hydraulic pump may arise.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

2-step variable valve lift apparatus actuated by dual roller bearings using electromagnetic system


The present invention includes a base frame or hitch receiver which can be attached to the under surface of a pulling vehicle. A hitch frame is pivotally mounted to the base frame for pivotal movement about a horizontal axis. An air bag is positioned between the base frame and the hitch frame and is adapted to collapse in response to downward movement of the forward end of the hitch frame. This collapsing of the air bag causes the air within to be compressed so that it resist downward movement of the forward end of the hitch bar.

The present invention relates to a trailer hitch cushioning device and method for using same.
Trailer hitches are generally used to connect a pulling vehicle to a trailer. A typical example of such a combination is shown in FIG. 1 which shows a pulling vehicle 10 which is pulling a trailer 12. A trailer tongue 14 extends from the front of trailer 12 and includes a hitch socket 16 at its forward end. A ball hitch 18 is fitted within the hitch socket and secured in place to attach the trailer 12 to the vehicle 10. The structure shown in FIG. 1 is merely an example, and any kind of trailer hitch, whether a ball hitch or other types of hitching devices may be utilized with respect to the present invention. When the vehicle 10 pulls the trailer 12 the load in the trailer creates a downward force on the hitch socket 16. During the movement of the vehicle 10 when the trailer crosses a bump, this movement can have an erratic effect upon the pulling vehicle 10 and can influence the steerage and bouncing of the vehicle 10. Therefore it is desirable to provide a means for cushioning or damping the downward force created by the front end of the trailer tongue 14 during movement of the vehicle and the trailer over a bump.
Therefore a primary object of the present invention is the provision of an air cushioning or damping device and method for using same which dampens the downward movement of the trailer tongue in response to going over bumps or other irregular surfaces.
A further object of the present invention is the provision of a trailer hitch cushioning device and method for using same which is easy to mount to the underside of a towing vehicle, or which can be attached to a conventional hitch receiver already mounted to a vehicle.
A further object of the present invention is the provision of a trailer hitch cushioning device and method for using same which permits pivotal movement of the hitch frame relative to a base frame that is bolted to the vehicle.
A further object of the present invention is the provision of a trailer hitch cushioning device and method for using same which utilizes an air bag to cushion the downward movement of the hitch as it pivots relative to a base frame.
A further object of the present invention is the provision of a trailer hitch cushioning device and method for using same which can be pivoted either at the rear of the hitch frame, at the front of the hitch frame, or at any place along the intermediate length of the hitch frame.
A further object of the present invention is the provision of a trailer hitch cushioning device and method for using same which utilizes an air bag positioned between the hitch and the pivot point of the hitch frame.
A further object of the present invention is the provision of a trailer hitch cushioning device and method for using same which places the pivot point of the hitch frame between the air bag and the hitch.
A further objection of the present invention is the provision of a trailer hitch cushioning device and method for using same which permits the air bag to be collapsed either in a vertical direction or in a horizontal direction in response to downward movement of the hitch frame.
A further object of the present invention is the provision of a trailer hitch cushioning device and method for using same which are economical in manufacture, durable in use, and efficient in operation.

Trailer hitch cushioning device and method for using same


An apparatus to facilitate a tracking of surface properties is disclosed. The apparatus includes one or more processors to receive a memory request, access a virtual to virtual page table to retrieve an address storing surface properties metadata, and process the memory request, wherein the virtual to virtual page table provides a mapping between a main surface and an auxiliary surface including the surface properties metadata.

As the graphics industry moves towards higher resolutions, bandwidth compression is critical to ensure that hardware/memory subsystems can support a required bandwidth. Since three-dimensional (3D) and media workloads have fundamentally different properties, optimal compression ratios are achieved by using optimized algorithms for each workload type. This requires software tracking, which results in significant overhead in the software stack, if even supported the operating system. A similar issue exists when software has to keep track of whether a surface is "clear" compressed.
Additionally, there is a similar problem for handling encrypted and clear surfaces. In such instances, any input received from an application is clear content and any surface written by a graphics processing unit (GPU) is encrypted. Thus, software needs to maintain these states as well.


A pullout mechanism for a drawer device includes a first and second guide surfaces, each extending from a first end to a second end, and first and second wheels which run on the respective first and second guide surfaces. The wheels are connected together in a rotationally fixed manner by a shaft mounted to the drawer device. The guide surfaces are provided for attachment to or formation on a frame, such as a frame of an interior trim part of a vehicle. Alternatively, the wheels can be connected to the frame and the guide surfaces to the drawer device. The pullout mechanism further includes first and second pulling devices such as cables, each of which at least partially encircles the first and second wheels, respectively, and is fastened in a pre-stressed manner to the two ends of the respective first and second guide surfaces.

DE 1 866 013 U describes a guide arrangement on items of furniture for parts which can be pulled out on two guide and support faces, such as drawer devices.
It is an object of the invention to reduce the risk of tilting and jamming in a pullout mechanism for a drawer or a drawer device and to create a vehicle comprising such a pullout mechanism or comprising such a drawer device.

Pullout mechanism for a drawer device, drawer device comprising a pullout mechanism and vehicle comprising a drawer device


Disclosed herein are methods for operating a reformer and for operating a vehicle. In one embodiment, the method for operating the reformer comprises: introducing an oxidant and fuel to a reformer at greater than or equal to about 25,000/hr space velocity; combusting the oxidant and the fuel the reformer to produce a combustion gas, wherein the reformer comprises a reformer substrate comprising a reformer catalyst and having a thermal conductivity of greater than or equal to about 35 W/m° K; extinguishing the combustion; and introducing additional fuel and oxidant to the reformer at an air to fuel weight ratio appropriate for reforming. A method of using the reformate produced to reduce cold start emissions and/or regenerate an exhaust control device is also disclosed.

Tighter emission standards and significant innovation in catalyst formulations and engine controls has led to dramatic improvements in the low emission performance and robustness of gasoline and diesel engine systems. However, many technical challenges remain to make the conventionally fueled internal combustion engine a nearly zero emission system having the efficiency necessary to make the vehicle commercially viable.
The automotive industry has made very significant progress in reducing automotive emissions in both the mandated test procedures and the "real world". This has resulted in some added cost and complexity of engine management systems, yet those costs are offset by other advantages of computer controls: increased power density, fuel efficiency, drivability, reliability and real-time diagnostics.
Future initiatives to require zero emission vehicles appear to be taking us into a new regulatory paradigm where asymptotically smaller environmental benefits come at a very large incremental cost. Yet, even an "ultra low emission" certified vehicle may emit high emissions in limited extreme ambient and operating conditions or with failed or degraded components, and especially during cold start.
One approach to addressing the issue of emissions is the employment of fuel cells, particularly solid oxide fuel cells ("SOFC"), in an automobile either as a primary or secondary source of power. A fuel cell is an energy conversion device that generates electricity and heat by electrochemically combining a gaseous fuel, such as hydrogen, carbon monoxide, or a hydrocarbon, and an oxidant, such as air or oxygen, across an ion-conducting electrolyte. The fuel cell converts chemical energy into electrical energy. SOFCs are constructed entirely of solid-state materials, utilizing an ion conductive oxide ceramic as the electrolyte. An electrochemical cell in a SOFC may comprise an anode and a cathode with an electrolyte disposed there between. The oxidant passes over the oxygen electrode (cathode) while the fuel passes over the fuel electrode (anode), generating electricity, water, and heat. The use of the SOFC, and fuel cells in general, reduce emissions through their much greater efficiency, and so require less fuel for the same amount of power produced, as compared to conventional hydrocarbon fueled engines. Additionally, a fuel cell may be employed to supplement a conventional engine; in this way the engine may be optimized for primary traction power, while the fuel cell may provide other power needs for the vehicle, i.e. air-conditioner, communication and entertainment devices. Additionally, the fuel reformer—fuel cell system may be operated while the engine is off, permitting electrically powered devices to operate, and so further reducing emissions by providing power using a more fuel efficient fuel cell to meet the vehicle operator's needs.
To facilitate the production of electricity by the SOFC, a direct supply of simple fuel, e.g., hydrogen, carbon monoxide, and/or methane is preferred. However, concentrated supplies of these fuels are generally expensive and difficult to supply. Therefore, the fuel utilized may be obtained by processing a more complex fuel source. The actual fuel utilized in the system is chosen based upon the application, expense, availability, and environmental issues relating to the fuel. Possible fuels include hydrocarbon fuels, including, but not limited to, liquid fuels, such as gasoline, diesel fuel, ethanol, methanol, kerosene, and others; gaseous fuels, such as natural gas, propane, butane, and others; "alternative" fuels, such as biofuels, dimethyl ether, and others; synthetic fuels, such as synthetic fuels produced from methane, methanol, coal gasification or natural gas conversion to liquids, and combinations comprising at least one of the foregoing methods, and the like; as well as combinations comprising at least one of the foregoing fuels. The preferred fuel is based upon the types of equipment employed, with lighter fuels, i.e., those that may be more readily vaporized and/or conventional fuels, which are readily available to consumers being generally preferred.
Processing or reforming of hydrocarbon fuels, such as gasoline, may be completed to provide an immediate fuel source for rapid start up of the fuel cell as well as protecting the fuel cell by breaking down long chain hydrocarbons and by removing impurities. Fuel reforming may include mixing fuel with air, water and/or steam in a reforming zone before entering the reformer system, and converting a hydrocarbon (such as gasoline) or an oxygenated fuel (such as methanol) into hydrogen (H2) and byproducts (e.g. carbon monoxide (CO), carbon dioxide (CO2) methane (CH4), inert materials (e.g., nitrogen (N2), carbon dioxide (CO2), and water (H2O)). Approaches to reforming include steam reforming, partial oxidation, dry reforming, and combinations comprising at least one of the foregoing. Both steam reforming and dry reforming are endothermic processes, while partial oxidation is an exothermic process.
Accordingly, a SOFC may be used in conjunction with a fuel reformer to convert a hydrocarbon-based fuel to hydrogen and carbon monoxide (the reformate) usable by a fuel cell. Preferably, the reformer has a rapid start, a dynamic response time, and excellent fuel conversion efficiency. It is also preferred for the reformer to have a minimal size and reduced weight, as compared to other power sources. However, reformers operate at temperatures that may be greater than about 600° C., and may exceed about 1000° C. or more. At lower temperatures, for example during start-up, deposition of carbonaceous matter (or soot) upon the catalyst may adversely affect the reformer's efficiency, reduce reformer life, and/or damage fuel cell components. Accordingly, it is beneficial to reduce the time required by a reformer and/or fuel cell system to reach an operational temperature.

Method of operating a reformer and a vehicle


A method and apparatus for decoding a partial response encoded signal to generate a decoded signal. The first stage of the apparatus, a first delay filter, receives the partial response encoded signal and filters it with a delay characteristic of (1-D.sup.2)(1+D). The second stage, a timing system, generates a digital signal representative of the first filtered signal. The timing system includes an equalizer with an EPR4 equalization characteristic. The third stage, a second delay filter, filters the signal with a delay characteristic of 1-D. The final stage, a partial Viterbi decoder, generates the decoded signal.

Digital communication channels are used in a variety of applications. One area of advancement is in increasing the amount of data which can be encoded into a channel of a given bandwidth. When applied to tape or disk drives, increasing the channel data rate while keeping the bandwidth constant produces a corresponding increase in the linear density of recorded data. However, a problem arises as the channel data rate increases while bandwidth is held constant: individual symbols spread so much that they interfere with sample values of adjacent intervals.
One way to deal with intersymbol interference is to purposely introduce a prescribed amount of intersymbol interference which is accounted for in the detection circuitry. One such technique is the well-known Partial Response (PR) signaling. In PR signaling, channel filters limit the spectrum so that the main part of each pulse extends across more than one signal interval and contributes to more than one sample time. A particular arrangement of PR signaling, in which the pulse is exactly three clock periods wide at its base, is known as PR Class 4 (PR4).
Problems arise with PR4 detection channels at high linear densities. Such channels require a great deal of equalizer boost. This requires the use of an expensive and complex multi-stage equalizer having considerable power consumption. For example, in some integrated decoding channels, the equalizer may use as much as half of the chip power dissipation. In addition, such equalization amplifies the noise in the channel, which may result in unreliable clocking.

PRML channel with EPR4 equalization and clocking

International Business Machines Corporation


A Group III nitride semiconductor light-emitting device includes at least an n-type-layer-side cladding layer, a light-emitting layer, and a p-type-layer-side cladding layer, each of the layers being formed of a Group III nitride semiconductor. The n-type-layer-side cladding layer is a superlattice layer having a periodic structure including an InyGa1-yN (0<y<1) layer, an AlxGa1-xN (0<x<1) layer, and a GaN layer. The n-type-layer-side cladding layer has a four-layer periodic structure including a second GaN layer interposed between the InyGa1-yN (0<y<1) layer and the AlxGa1-xN (0<x<1) layer.

1. Field of the Invention
The present invention relates to a Group III nitride semiconductor light-emitting device which suppresses an increase in driving voltage and which exhibits improved emission performance.
2. Background Art
Hitherto, various known Group III nitride semiconductor light-emitting devices are known, and some of them are disclosed in Japanese Patent Application Laid-Open (kokai) Nos. H11-191639 and 2007-180499. Japanese Patent Application Laid-Open (kokai) No. H11-191639 discloses a Group III nitride semiconductor light-emitting device having a structure in which a light-emitting layer is stacked on n-type layers; i.e., a third layer bonded to the light-emitting layer, a second layer bonded to the third layer, and a first layer bonded to the second layer. The second layer has a superlattice structure formed of two layers (AlGaN layer and GaN layer) or a superlattice structure formed of two layers (AlGaN layer and InGaN layer), and the third layer has an impurity concentration lower than that of the second layer. This configuration of the device reduces driving voltage.
Japanese Patent Application Laid-Open (kokai) No. 2007-180499 discloses a Group III nitride semiconductor light-emitting device including a substrate, an n-type semiconductor layer on which an n-electrode is formed, and an intermediate layer provided between the substrate and the n-type semiconductor layer and having a periodic structure formed of AlGaN, GaN, and InGaN. The intermediate layer improves the crystallinity of the n-type semiconductor layer which serves as a current path and on which the n-electrode is formed, thereby improving the reliability of the device. In this device, propagation of threading dislocations generated in a layer provided below the intermediate layer into a layer provided above the intermediate layer is blocked by means of the periodic structure of the intermediate layer. This configuration of the device improves the crystallinity of the layer provided above the intermediate layer, thereby improving emission performance, reverse breakdown voltage, and electrostatic breakdown voltage.
However, as described in Japanese Patent Application Laid-Open (kokai) No. H11-191639, when the second layer, which is not directly bonded to the light-emitting layer, has a superlattice structure formed of AlGaN and GaN layers or a superlattice structure formed of AlGaN and InGaN layers, reduction of driving voltage fails to be attained. In addition, since the AlGaN layer acts as a barrier against electrons, resistance to electrons is not reduced, and confinement of holes in the light-emitting layer is not improved. In the device disclosed in Japanese Patent Application Laid-Open (kokai) No. 2007-180499, the light-emitting layer exhibits improved crystallinity, but confinement of holes in the light-emitting layer fails to be attained, and resistance to electrons is not reduced. Thus, these conventional devices fail to achieve both reduction of driving voltage and improvement of emission performance.

Group III nitride semiconductor light-emitting device including a superlatice layer


A distribution valve for directing high pressure coolant to various stations of a metalworking machine or similar device. A hollow shaft directs high pressure fluid to an aperture in a seal plate. The aperture is selectively coupled to one of several seals mounted in a housing. Each seal is formed with an axial passageway for directing fluid to its respective station when aligned with the aperture. A biasing means holds the seal against the seal plate to provide a leak free interface.

In recent years the use of high pressure coolants in metalworking machinery has proven to be useful in increasing production efficiency and finishes of machined parts. High pressure hydraulic fluids and high pressure fluid systems in general have relied upon the use of various valves and valving techniques for the distribution of the high pressure fluids to various components. These valves variously called distribution valves, distribution devices, rotary manifolds, and other similar nomenclature employ either elastomer seals as the primary sealing component, or metal to metal sealing elements as their primary dynamic (moving) seal element.
Coolants and most fluids used as cutting oils or lubricants for use in metalworking machines are contaminated or become contaminated with particles of varying sizes. These particulates are either airborne, inherent in the fluid, or generated by wear and corrosion in the systems, in which the fluid flows. In metalworking machines the coolant is contaminated with chips from the material being cut or ground. Most fluid systems employ filtration designed to remove particles of various sizes. No filtration is perfect and consequently particles of metals and corrosion products and other minerals are always present in any flowing medium.
In valves and distribution devices employing elastomeric seals, these particles become trapped or embedded in the elastomer seals or between the seals and the moving components in a dynamic seal, causing wear, cutting and ultimately erosion and destruction of the seal and other components in the system ultimately leading to leakage and failure of the components and possible failure of the system.
In valves and distribution devices employing metal to metal seals, the particles can become trapped in the very small clearances between the sealing surfaces. The larger particles may become trapped as the flow carries these particles over the overlapping edges of the sealing elements and as these edges close on each other, much the same as a scissor closing on an obstruction. Both of these actions will damage the sealing surfaces and again cause failure of the component. Some of the existing methods of sealing employ soft metals such as brass or other copper alloy sealing elements. These devices exhibit similar failure modes as do the elastomer sealed components.
Finally it should be noted that in most prior art distribution valves, the flow passages are reduced in diameter to accommodate the sealing elements.
Accordingly, there is a current need for a valve distribution system which is damage resistant to contaminants in the flow medium.

Distribution valve for high pressure coolant used in a metalworking machine application


A time-of-flight mass spectrometer having a chamber with electrodes to generate an electric field in the chamber and electric gating for allowing ions with a predetermined mass and velocity into the electric field. The design uses a row of very thin parallel aligned wires that are pulsed in sequence so the ion can pass through the gap of two parallel plates, which are biased to prevent passage of the ion. This design by itself can provide a high mass resolution capability and a very precise start pulse for an ion mass spectrometer. Furthermore, the ion will only pass through the chamber if it is within a wire diameter of the first wire when it is pulsed and has the right speed so it is near all other wires when they are pulsed.

Mass spectrometers are used extensively in the scientific community to measure and analyze the chemical compositions of substances. In general, a mass spectrometer is made up of a source of ions that are used to ionize neutral atoms or molecules from a solid, liquid, or gaseous substance, a mass analyzer that separates the ions in space or time according to their mass or their mass-per-charge ratio, and a detector. Several variations of mass spectrometers are available, such as magnetic sector mass spectrometers, quadrupole mass spectrometers, and time-of-flight ion mass spectrometers.
Time-of-flight ion mass spectrometers (TOF-IMS) can detect ions over a wide mass range simultaneously. Mass spectra are derived by measuring the times for individual ions to traverse a known distance through an electrostatic field free region. In general, the mass of an ion is derived in TOF-IMS by measurement or knowledge of the energy, E, of an ion, measurement of the time, t1, that an ion passes a fixed point in space, P1, and measurement of the later time, t2, that the ion passes a second point, P2, in space located at a predetermined distance, d, from P1. Using an ion beam of known energy-per-charge E/q, the time-of-flight (tTOF) of the ion is tTOF=t2−t1, and by the ion speed. In a gated TOF-IMS uncertainty in tTOF may result, for example, from ambiguity in the exact time that an ion entered the spectrometer.
One method of attempting overcome this limitation in TOF-IMS utilizes a thin foil located at the entrance to spectrometer. The thin foil method works best with ions having sufficient energy to traverse the foil. Secondary electrons generated by the interaction of the ion with the foil are detected and provide an indication of when the ion entered the spectrometer. However, the foil method is not without its own limitations. These limitations include the requirement that the incident ion have sufficient energy to transit the foil, the energy degradation of the sample ion due to interaction with the foil, and the angular scattering of the sample ion due also to its interaction with the foil.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for resolving when the time that at least one ion entered the spectrometer without substantially reducing the energy of the at least one ion

High precision electric gate for time-of-flight ion mass spectrometers

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration


A sol of inorganic oxide particles is stably dispersed in a hydrophilic organic solvent containing a hydrocarbon such as a paraffinic hydrocarbon or a naphthenic hydrocarbon. The sol contains a dispersion medium containing an organic solvent containing a C6-18 paraffinic hydrocarbon, a C6-18 naphthenic hydrocarbon, or a mixture of these, a C4-8 alcohol having a carbon chain with a carbon-carbon bond in the molecule in an amount of 0.1 to 5% by mass in the entire dispersion medium, and inorganic oxide particles having an average particle diameter of 5 to 200 nm as measured by dynamic light scattering as a dispersoid, wherein the inorganic oxide particles contain a C1-3 alkyl group bonded to a silicon atom and a C4-18 alkyl group. The paraffinic hydrocarbon is a normal paraffinic hydrocarbon or an isoparaffinic hydrocarbon. The naphthenic hydrocarbon is a saturated aliphatic cyclic hydrocarbon substitutable with a C1-10 alkyl group.

An inorganic oxide sol dispersed in an organic solvent is useful when the sol is dispersed in a resin composition (e.g., plastic or varnish composition).
For example, there has been disclosed a method for preparing a silica sol dispersed in a non-polar organic solvent, in which the pH of a silica sol dispersed in an aqueous solvent is adjusted to 1 to 5, and then a non-polar organic solvent and a surfactant are added to the dispersed silica sol to form an emulsion, followed by azeotropic dehydration; and a method for preparing a silica sol dispersed in a non-polar organic solvent, in which a non-polar organic solvent is added to a silica sol dispersed in an alcohol, to thereby perform solvent replacement (see Patent Document 1). The non-polar organic solvent used in the disclosed method is a hydrocarbon such as benzene, toluene, heptane, or octane, a petroleum solvent such as kerosene, or a petrochemical solvent. As disclosed in the aforementioned method, a hydrophobic silica sol is prepared by coating the surfaces of silica particles with an alkyl-substituted silane such as octadecylmethyldimethoxysilane.
There has also been disclosed a process in which an aqueous silica sol is converted into an isopropyl alcohol silica sol through solvent replacement; the solvent is replaced by an alcohol of high boiling point; a silylation agent (e.g., trimethylchlorosilane) is added to the silica sol to thereby prepare a trimethylsilylated silica sol; and the solvent is removed to yield powdery silica (see Patent Document 2).
There has also been disclosed a method for producing an organic solvent silica sol, in which the surfaces of silica particles dispersed in a hydrophilic solvent (silica sol) are treated with an alkylalkoxide silane in the presence of a primary alcohol such as butyl alcohol, and the hydrophilic solvent is replaced by a solvent such as a ketone, an ester, an ether, or a hydrocarbon (see Patent Document 3).

Inorganic oxide sol dispersed in hydrocarbon and production method therefor


Provided is a wind turbine including a generator enclosed in a generator housing, the generator housing including a rotating housing and a stationary housing, whereby the rotating housing is separated from the stationary housing by a first gap; a canopy mounted on a tower and including an electrical connection to a down conductor of the tower, wherein the canopy is separated from the generator housing by a second gap; a lightning current path provided by a plurality of brush assemblies mounted on the stationary housing, wherein a brush assembly includes a brush holder mounted on the stationary housing such that a carbon brush extends across the first gap to make electrical contact with the rotating housing; and an electrical connector extending across the second gap to electrically connect the brush holder to the canopy. Also provided is a method of providing a lightning current path for such a wind turbine.

A wind turbine is generally equipped with a lightning protection system (LPS) that aims to provide a current path to guide lightning current to ground. Since the rotor blades are the most vulnerable targets on account of their height and exposed position, each rotor blade usually incorporates a down conductor in its interior. Electrically conductive "attractors" or targets can be provided at one or more points on the blade exterior and connected to the down conductor, in order to attract a lightning strike in a controlled manner. The down conductors of the rotor blades lead to the hub. It is then necessary to provide a bridge between the rotating hub and the stationary nacelle so that the lightning current can be guided to a down conductor of the wind turbine tower and then to ground. One way of doing this is to use a sliding contact between a rotating down conductor in the hub and a stationary down conductor in the nacelle. Such an approach is proposed by WO2011069686A1 for a direct-drive wind turbine, for the lightning current path from rotor blade down conductor to a stationary main shaft of the generator. The same principle is also applied in CN201125843Y for the lightning current path from rotor blade down conductor to a nacelle down conductor in an indirect-drive wind turbine.
However, depending on the generator design, it may be difficult to ensure that very high lightning currents are reliably brought to ground through such current bridges. It may happen that some part of the lightning current seeks an alternative route to ground, resulting in flashover to components that may be severely damaged as a result. For example, flashover to a main bearing can severely damage the bearing, leading to downtime and costly repair procedures.
Furthermore, a requirement that must be fulfilled by certain types of wind turbines is that of EMC (electromagnetic compatibility) screening.

Lightning protection system for wind turbine


A material removal system for removing oversized materials from a material stream. This material removal system comprises a first transfer system that is used to transport a material stream, a pulley separator, and a gap that is at least as small as the length of the oversized materials that are to be removed from the material stream. Moreover, the pulley separator comprises a rotatable outer shell that has a tubular width and circular cross-section. The pulley separator is located at a discharge end of the first transfer system to create a gap that is at least as small as the length of the oversized materials to be removed.

What is presented is a system and method for the removal of oversized material from a material stream. Material sorting systems are found in shredding mills, scrap metal plants, and the like, and they typically have sizing grates intended to limit the size of material passing through to the end of the system, ensuring a relatively uniform material size exiting the sorting system. However, these grates will only screen materials in two dimensions and elongated pieces of oversized material, often called "pokers," sometimes pass through. While these pokers represent a tiny percent of the weight passing through these systems, they cause a majority of the material handing problems because these pokers easily jam in transfer chutes, poke holes in belts of conveyors (if any exist), and are hazardous to the operating and handpicking personnel. Thus, it would be desirable to have a system and method that removes oversized material within a material stream.

Oversized material removal system and method


A fine-patterning method includes forming a mask layer with lower and upper mask layers on an underlying layer, forming a pair of sacrificial patterns on the mask layer, forming a connection spacer between the sacrificial patterns and first spacers that are spaced apart from each other with the pair of sacrificial patterns interposed therebetween and covering side surfaces of the sacrificial patterns, etching the upper mask layer using the first spacers and the connection spacer as an etch mask to form upper mask patterns, forming second spacers to cover side surfaces of the upper mask patterns, etching the lower mask layer using the second spacers as an etch mask to form lower mask patterns, and etching the underlying layer using the lower mask patterns as an etch mask.

Example embodiments of the inventive concepts relate to methods of forming fine patterns and to related methods of fabricating semiconductor devices using such fine patterning techniques.
In order to realize a highly-integrated semiconductor device, it is necessary to form fine patterns. For example, one method of increasing the number of devices formed within a given area is to reduce the size of the patterns used to form the devices. In other words, patterns should be formed in such a way that a pitch thereof or a sum of a width of each pattern and a space between two adjacent patterns is reduced. However, as the pattern sizes are reduced the resolution in a photolithography processes are being stretched to the limit, and thus, it becomes more and more difficult to form patterns having finer pitches.

Fine patterning methods and methods of fabricating semiconductor devices using the same


The manganese-zinc system ferrite of the invention has an initial permeability .mu.i at a frequency of 100 kHz and at 25.degree. C. of 5,000 or more, and a core loss Pcv at a frequency of 100 kHz and at 200 mT and 40.degree. C. of 400 kW/m.sup.3 or less.

A manganese-zinc system ferrite is used as a material of a core of a coil component and a transformer of various communication equipments and consumer equipments. In these applications, particularly in a ferrite core for a communication equipment, high permeability characteristics are required at a relatively high frequency in a broad range (about from 100 to 500 kHz). A manganese-zinc system ferrite having a high initial permeability .mu.i in such a frequency range is described in JP-A-6-204025 (added with Bi and Mo, initial permeabilities .mu.i at 100 kHz and 500 kHz of 9,000 or more and 3,000 or more, respectively). In conventional manganese-zinc system ferrite in this application, there has been no need to consider a saturation magnetic flux density Bs and direct current overlapping characteristics.
However, with the spread of a portable communication equipment, such as a portable computer terminal, and an ISDN in recent years, further miniaturization of such equipments is demanded, and in a manganese-zinc system ferrite for these communication equipments, demands for a high saturation magnetic flux density, high direct current overlapping characteristics and a low core loss are being increased.


For producing a mother matrix mould                of a full or partial dental prosthesis or        of a temporary crown or bridge        or of a permanent crown or bridge,        the data of a digitalised virtual model reflecting the status of the jaw is used to generate a data set        of the digital tooth set-up of the full or partial dental prosthesis or        of the temporary crown or bridge or        of the permanent crown or bridge,        based on which a rapid manufacturing or rapid prototyping method is used to produce a functional model of the full or partial dental prosthesis or of the temporary crown or bridge or of the permanent crown or bridge that is then invested in a curable elastic impression material from which the mother matrix mould is produced after curing the elastic impression material.

The production of prosthetic restorations such as crowns, bridges, partial or full dentures follows known methods. These include, e.g., the conventional powder/liquid technology methods that have been known for long and are described in the literature (e.g. EP 1 243 230 A2, U.S. Pat. No. 6,881,360 B2 and Ullmann (Dental Materials, Ullmann's Encyclopedia of Industrial Chemistry, Copyright 2002 by Wiley-VCH Verlag)).
In general, three different main classes of materials for production of full dentures are known. These are polymethylmethacrylate (PMMA)-based two component materials [commercially available as Palapress, Paladur (Heraeus Kulzer, DE), SR 3/60® Quick (Ivoclar, LI), Degupress® (Degussa-Hüls, DE)]; PMMA-free hot-curing materials [commercially available e.g. as Paladon® 65 (Heraeus Kulzer, DE), SR 3/60®, SR Ivocap® (Ivoclar, LI), Lucitone® (Dentsply, US)] and injection molded masses for thermoplastic processing.
Thermoplastic materials are heated and injected into a hollow space, usually through an injection molding method. A known method called "Polyapress"® is distributed, amongst others, by Bredent, Senden (DE). There have been numerous attempts to use polymers such as PVC, polyurethane, polyamide or polycarbonate (Ullmann's, ibid 5.1.5. Other Denture Resins).
Moreover, there are methods that are based on light- or microwave-cured 1-component materials (e.g. Versyo.com® made by Heraeus Kulzer) (Ullmann's, ibid 5.1.3. Light-Cured Polymers, 5.1.4. Microwave-Cured Polymers).
The work steps required for preparation of the processing of the plastic materials are the same for all of these materials.
Moreover, techniques for the build-up of layers are known in dental engineering. These are used in combination with light-curing materials in most cases, for example for veneering metal crowns or production of a prosthesis. The advantages of said methods include the level of control over the procedure and the ability to vary the colors in order to attain aesthetically pleasing dental work.
The use of rapid prototyping methods in dental engineering has also been proposed. These involve working with layers that can be polymerized (DE 101 14 290 A1, DE 101 50 256 A1) or ink jet powder printing (U.S. Pat. No. 6,322,728 B1).
Essentially, the production of full dentures involves the following steps:
dentist taking an impression;
                a) fabrication of a model reflecting the shape of the jaw;        b) setting-up the artificial teeth in wax and carving the gingiva;        c) trying-in and correcting, if applicable, done by the dentist or the dental laboratory;        d) investing the wax prosthesis in dental plaster, silicone or agar agar;        e) removing the wax by boiling it out with hot water;        f) filling the hollow space thus generated with a denture plastic material (e.g. PalaXpress®),        g) curing and finishing the dental prosthesis.
Attempts are being made to an increasing degree to simplify this complex procedure. Accordingly, Heraeus Kulzer presented the "Filou® 28" set-up aid (EP 1 704 831 A1) at the IDS 2005. This aid was the first to reduce the time needed for setting-up the artificial teeth in wax.
Further developments reflect a trend of increased digitalization in dental engineering. Accordingly, ceramic restorations are already being produced through CAD/CAM technologies. Digital technologies are becoming distributed more broadly and are being accepted to an increasing degree in dentistry, e.g. scanning technologies (Lava C.O.S. made by 3M Espe) or virtual applicators and virtual set-ups of teeth.
DE 101 14 290 B4 described rapid prototyping methods for dental technology. Rapid Prototyping (German: schneller Prototypenbau) is a method for rapid production of sample components based on design data. Accordingly, rapid prototyping methods are manufacturing methods aiming to implement existing CAD data directly and rapidly in work pieces, if possible without manual detours or moulds. The relevant data interface for this group of methods is the STL format. The methods that have become known by the name of Rapid Prototyping since the 1980s are usually primary forming methods that build-up the work piece in layers from shapeless or neutral-shape material utilizing physical and/or chemical effects. It is a disadvantage of such layering methods that they always generate restorations of anisotropic structure such that post-processing, e.g. through additional light curing or thermal treatment, is required in order to attain the requisite stability. Another disadvantage is that aesthetically-pleasing coloring is very difficult to achieve. And the quality of the surface produced appears just as disadvantageous owing to the layered structure. The materials posses marked, tangible roughness on the order of tenths of millimeters.
The object is to simplify the classical production process that is described above. In this context, the disadvantages described above are to be circumvented or prevented.
The object is met by producing a mother matrix mould                of a full or partial dental prosthesis or        of a temporary crown or bridge        or of a permanent crown or bridge,whereby the data of a digitalized virtual model reflecting the status of the jaw is used to generate a data set        of the digital tooth set-up of the full or partial dental prosthesis or        of the temporary crown or bridge or        of the permanent crown or bridge on the basis of which a rapid manufacturing or rapid prototyping method is used to produce a functional model of the full or partial dental prosthesis or temporary crown or bridge or permanent crown or bridge;being invested in investment material;and a mother matrix mould being produced from the cured investment material.
The term, Rapid Manufacturing or (German) Schnelle Fertigung, refers to methods and production procedures for rapid and flexible production of components and series' through tool-less fabrication based directly on the CAD data. The materials that are used include glass, metal, ceramic materials, plastic materials and new materials (such as UV-curing sol-gel, see, e.g., Multi Jet Modeling) [. . . ].
Since Rapid Manufacturing always focuses on producing the end-product directly, it is fundamentally different from Rapid Prototyping and Rapid Tooling (rapid toolmaking).
Producing a positive likeness of the dental prosthesis as place holder, e.g., according to the rapid prototyping method, said positive likeness of the dental prosthesis can be invested in an elastic impression mass (e.g. alginate, agar-agar or silicone) and can subsequently be removed from the mould. The two-part hollow mould thus generated can be fitted with stock teeth and—after closing the two halves of the mould—the hollow space thus produced can be filled by casting with denture material.
The advantages of the method are as follows:
Established dental materials such as pre-formed stock teeth and time-proven denture materials can be used.
There is no limitation with regard to the selection of materials in terms of their functional, aesthetic and toxicological properties.
The mother matrix mould or flask can be produced according to an inexpensive conventional casting procedure and does not have to be built-up in layers in a time-consuming and expensive manner.
The production method according to the invention comprises, e.g., the following steps for full dentures:
Either
    P-A Production of a model reflecting the shape of the jaw based on the impression taken by the dentist    P-B Digitalization of the modelor
PA+PB Provision of model data from the digital X-ray image or intraoral scan;    P-C Automatic digital set-up using previously entered 3D models of artificial teeth, as described, e.g., in DE 103 04 757 B4;    P-D Digital production of a functional model of the prosthesis from the data of the model from step C according to the rapid prototyping/rapid manufacturing method, optionally including the provision of casting channels;    P-E Investing the functional model, preferably in silicone;    P-F Cutting-open the investment and removing the functional prosthesis from the mould;    P-G Inserting the stock teeth;    P-H Filling the remaining hollow space with denture plastic material (e.g. PalaXpress®);    P-I Finishing the prosthesis.
The functional model can be produced through rapid manufacturing or rapid prototyping methods such as milling methods, 3D printing methods, stereolithography, laser sintering or other rapid prototyping methods. As an option, the surface of the functional model can be post-processed after production, in particular through smoothing and/or polishing. The functional model can consist either of a stable polymer or a wax-like material which is still amenable to slight geometric corrections while trying it in in the mouth of the patient as an option.
The functional model is preferably invested using a commercially available model-making silicone, possibly also using reinforcing elements, such as, e.g., mesh structures which provide additional mechanical stability to the investment and thus improve the geometric accuracy of fit. The silicone is selected such that it has sufficiently high viscosity in its cured state for the mould to be stable and the stock teeth to be held in the intended positions during the subsequent steps of processing. However, the silicone must not be too solid either to allow the finished prosthesis to be removed from the mould without difficulty.
The invention is illustrated in more detail based on the flow diagrams shown in FIGS. 1A and 1B: The initial deviations from the traditional process are the production and handling of a digital model and virtual handling of the model during tooth set-up. Methods of this type and corresponding devices are described, e.g., in U.S. Pat. No. 6,152,731 A, U.S. Pat. No. 6,322,359 B1 and DE 103 04 757 B4. The essential feature of the invention is the production of a functional model through a rapid manufacturing or rapid prototyping method.
The functional model is then invested and the hollow space for casting the dental prosthesis is generated once the functional model is removed from the mould. Since the teeth have already been set-up virtually, the denture teeth can be placed directly in the sites provided for this purpose. The further processing (casting with denture base material and curing) is identical to the traditional method.
The method according to the invention is advantageous in that, while traditional materials are used for processing, the advantages of virtual articulation and tooth set-up can be utilized.
Another trying-in in the patient, which is obligatory in the traditional method, is not mandatory in this method. Dispensing with a trying-in session of this type also dispenses with having to send shipments back and forth between dental office and dental laboratory.
The functional model according to the invention can also be applied to the production of crowns and bridges described, e.g., in EP 1 864 627 A2.
Therefore, the invention also relates to a method for the production of crowns and bridges according to a digitalized virtual model that reflects the jaw status, comprising the steps    tKB-A taking a digital impression of the jaw and tooth status before the preparation;    tKB-B taking a digital impression of the jaw and tooth status after the preparation;    tKB-C digital production of the temporary crown or bridge    tKB-D producing a functional model from the digital data using a rapid manufacturing or rapid prototyping method;    tKB-E investing the functional model in an elastic impression material (e.g. silicone, agar-agar, alginate, dental plaster, refractory investment material);    tKB-F separating the investment and removing the functional model;    tKB-G filling a crown & bridge material into the remaining hollow space;    tKB-H solidification of the crown & bridge material.
The functional model can also be used in the production of ceramic crowns or bridges, which is also described, e.g., in EP 1 864 627 A2.
It is then a method for the production of permanent crowns and bridges made of ceramic materials according to a digitalized virtual model that reflects the jaw status, comprising the steps    d KB-A providing a data set from the digital impression of the jaw and tooth status before the preparation;    dKB-B providing a data set from the digital impression of the jaw and tooth status after the preparation;    dKB-C digital production of the crown or bridge    dKB-D producing a functional model from the digital data    dKB-E investing the functional model, preferably in an elastic impression material made of a porous, absorbent material, such as, e.g., dental plaster, taking the sinter shrinkage into consideration    tKB-F separating the investment and removing the functional model;    dKB-G congruent closing of the investment    dKB-H producing the mother matrix mould (rapid manufacturing or rapid prototyping)    tKB-G filling a ceramic slurry into the remaining hollow space    dKB-J removal from the mould once stability of shape is attained    dKB-Koptional further drying    dKB-L optional sintering of the ceramic blank, and    dKB-M firing.

Production of a negative mould for use in producing of a dental prosthesis, a temporary or permanent crown or bridge


The invention provides a transcutaneous energy transfer device having an external primary coil and an implanted secondary coil inductively coupled to the primary coil, electronic components subcutaneously mounted within the secondary coil and a mechanism which reduces inductive heating of such components by the magnetic field of the secondary coil. For one embodiment of the invention, the mechanism for reducing inductive heating includes a cage formed of a high magnetic permeability material in which the electronic components are mounted, which cage guides the flux around the components to prevent heating thereof. For an alternative embodiment of the invention, a secondary coil has an outer winding and either a counter-wound inner winding or an inner winding in the magnetic field of the outer winding. For either arrangement of the inner coil, the inner coil generates a magnetic field substantially canceling the magnetic field of the outer coil in the area in which the electronic components are mounted.

This invention relates to transcutaneous energy transfer (TET) devices and, more particularly, to such a device which includes a mechanism for protecting components mounted within a secondary coil from magnetic field induced heating.
Many medical devices are now designed to be implantable including pacemakers, defibrillators, circulatory assist devices, cardiac replacement devices such as artificial hearts, cochlear implants, neuromuscular simulators, biosensors, and the like. Since almost all of the active devices (i.e., those that perform work) and many of the passive devices (i.e., those that do not perform work) require a source of power, inductively coupled transcutaneous energy transfer (TET) and information transmission systems for such devices are coming into increasing use. These systems consist of an external primary coil and an implanted secondary coil separated by an intervening layer of tissue.
One problem encountered in such TET systems is that the best place to locate control circuitry for converting, amplifying and otherwise processing the signal received at the secondary coil before sending the signal on to the utilization equipment is within the secondary coil itself. However, there is also a significant magnetic field in the secondary coil resulting from the current induced therein, which field can induce heating of the components, particularly metallic components. As a minimum, such heating can influence the performance of various components, and in particular interfere with the desired uniform power applied to the equipment. In a worst case, the heating can be severe enough to cause damage or destruction to the components which can only be repaired or replaced through an invasive surgical procedure. Such heating can also cause injury or discomfort to the patient in which the components have been implanted.
Heretofore, in order to avoid such heating, it has either been necessary to be sure that the signal induced in the secondary coil is not sufficient to generate a magnetic field which would cause potentially damaging heating of the components or to mount the components at a less convenient location. The former is undesirable because it is generally not possible to eliminate significant heating of the components while still operating the device at required energy levels, and the later solution is not desirable since the output signal from the secondary coil can reach 500 volts and above at an operating frequency that can be in excess of 100 kHz. It is preferable that such high voltage signal not pass extensively through the body and it is difficult to provide good hermetically sealed connectors for signals at these voltages. It is therefore preferable that an auxiliary signal processing module, which may reduce the voltage to a value in the approximately 20 volt range, be included as close to the secondary coil as possible, a position inside the secondary coil being ideal for this purpose.
A need therefore exists for an improved technique for use with TET devices so as to enable at least selected electronic components to be mounted within the secondary coil with minimal heating of such devices.
In accordance with the above, this invention provides a transcutaneous energy transfer device which includes an external primary coil to which energy to be transferred is applied, an implanted secondary coil inductively coupled to the primary coil, each of the coils generating a magnetic field, and electronic components subcutaneously mounted within the secondary coil, with a mechanism being provided which reduces inductive heating of such components by the magnetic field of the secondary coil. For one embodiment of the invention, the mechanism for reducing inductive heating includes a cage formed of a high magnetic permeability material in which the electronic components are mounted. The material of such cage is preferably a ferromagnetic material such as a ferrite and is preferably sufficiently thick so that magnetic field values in the material are well below saturation and so that significant heat dissipation in the material does not occur. The material of the cage should however be as thin as possible while satisfying the above criteria. The cage may be thicker in areas of the cage experiencing high flux density and thinner in other areas. The cage may also be formed of a layer of ferromagnetic material laminated with at least one layer of a low magnetic conductivity material to enhance flux guidance.
Alternatively, the mechanism may include winding the secondary coil with a first number N1 of outer windings and a second number N2 of counter-wound inner windings, N1 being larger than N2. N1, N2 and the diameters of both the outer and inner windings are selected such that the magnetic field caused by the coils in the region of the components is reduced sufficiently to prevent significant component heating. For a preferred embodiment, N1, N2, and the diameters of the windings are selected so that the magnetic fields caused by the windings substantially cancel in the region of the components. For an illustrative embodiment, N1 is approximately 19, N2 is approximately 7, and the diameter of the outer winding is approximately 2.5 inches, and the diameter of inner winding is approximately 1.5 inches. Alternatively, the inner windings may be in the magnetic field of the outer winding, but not electrically connected thereto.
In another aspect of the invention, a transcutaneous energy transfer device is disclosed. The TET includes an external primary coil; an implantable secondary coil coupled to the primary coil; a cage formed of a high magnetic permeability material located within the secondary coil to reduce inductive heating of electronic components mounted therein caused by a magnetic field of the primary and secondary coils, wherein the cage has walls of varying thickness such that a lowest total mass is achieved without exceeding the saturation density of the cage material. In one embodiment, the thickness of the cage walls is a minimum thickness that results in magnetic flux density through the cage walls is approximately equal to the saturation density.
In another aspect of the invention, another transcutaneous energy transfer device is disclosed. This TET includes an external primary coil; an implantable secondary coil coupled to the primary coil; and a cage formed of a high magnetic permeability material located within the secondary coil to reduce inductive heating of electronic components mounted therein caused by a magnetic field of the primary and secondary coils, wherein the cage has a geometry configured to maximize permeability in flux pathway between the primary and secondary coils. In one embodiment, the cage has flanges that extend the high permeability shield material within the flux pathway.
In another embodiment of this aspect of the invention, the cage includes a cylindrical base; a lid shaped in the form of a disk; and the flanges integral with the base. The flanges extend a high magnetic permeable region from base into the magnetic flux pathway. Preferably, the flange is in-line with a shortest flux pathway between the primary and secondary coils, such as extending from base immediately adjacent to the secondary coil to guide the magnetic flux lines back toward the primary coil.
In another aspect of the invention, a transcutaneous energy transfer device is disclosed. This TET includes an external primary coil; an implantable secondary coil coupled to the primary coil; and a cage formed of a high magnetic permeability material within the secondary coil to house electronic components. The cage includes a base; and a self-aligning lid.
In one embodiment of this aspect of the invention, the base is cylindrical and the lid is shaped in the form of a disk. In anther embodiment, the base includes vertical walls. The lid includes an annular recessed shelf circumferentially formed around a mating surface of the lid configured to receive the vertical wall of the base.
In a stiff further aspect of the invention, a transcutaneous energy transfer device is disclosed. The device includes an external primary coil; an implantable housing formed of a substantially low thermal conductivity medium; a secondary coil, mounted within the implantable housing, coupled to the primary coil; a cage formed of a high magnetic permeability material within the secondary coil to house electronic components; and a heat distribution layer thermally coupled to the cage and to an internal surface of the housing. The heat distribution layer may be comprised of multiple alternating layers of high and low heat conductivity materials.
In a further aspect of the invention, a transcutaneous energy transfer system is disclosed. The TET includes a primary coil and an implantable secondary coil having an outer first winding having a first number of turns and a first diameter and an inner second winding having a second number of turns and a second diameter. A method for determining the second number of turns, includes the steps of: a) winding the first winding with a predetermined number of turns; b) inserting a magnetic field monitoring device in a central region of the secondary coil; c) applying a dc current through the first winding while monitoring a magnetic field in the central region; d) winding the second winding in a direction a direction of the first winding using a wire extension from the first winding; e) monitoring, as the second winding is wound in the step d), a strength of a magnetic field in the central region; and f) stopping the winding of the second winding when the magnetic field strength reaches approximately zero.
Further features and advantages of the present invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the drawings, like reference numerals indicate like or functionally similar elements. Additionally, the left-most one or two digits of a reference numeral identifies the drawing in which the reference numeral first appears.

Transcutaneous energy transfer device with magnetic field protected components in secondary coil


A method of assessing a tissue ablation treatment, including positioning a medical device adjacent a target tissue; measuring a first impedance magnitude a first frequency with the medical device; measuring a first impedance phase at a second frequency with the medical device; ablating at least a portion of the target tissue with the medical device; measuring at second impedance magnitude at a third frequency with the medical device; measuring a second impedance phase at a fourth frequency with the medical device; comparing at least one of (i) the first and second impedance magnitudes and (ii) the first and second impedance phases; and providing an indication of the efficacy of the ablation treatment based at least in part on the comparison.

Radiofrequency (RF) and cryogenic ablation procedures are well recognized treatments for vascular and cardiac diseases such as atrial fibrillation. The application of either RF or cryogenic treatment is usually based on the preference of the surgeon or the specific tissue to be treated. In either RF or cryogenic ablation, however, the location and quality of the lesion produced is a primary concern. The clinical success of cardiac tissue ablation to treat arrhythmias depends on efficacy and safety of the application of the selected energy. Many factors influence lesion size such as tissue-electrode contact force, ablation energy level, and cooling factors, that is, blood flow rate, tissue perfusion, and the duration of energy delivery. In addition, there are other factors that can limit deep lesion formation, such as early impedance rise that prevents continued energy delivery. Predicting and assessing lesion size and quality is important to the success of the ablation, but it has been difficult to achieve.
Current methods to identify a lesion's location and assess its quality include coupling a plurality of electrodes to the distal end of a medical device proximate a tissue to be treated, applying a voltage, and measuring impedance across the electrodes with the tissue to be treated completing the circuit. Electrical impedance is defined as the total opposition to alternating current by an electric circuit, equal to the square root of the sum of the squares of the resistance and reactance of the circuit and usually expressed in ohms. In general, the impedance decreases as cell membranes become ruptured and cellular fluids are released into the extracellular space in the regions of treated tissue. These treated regions then become necrotic. As such, impedance may be used to identify particular areas which have been treated and those that have not. It also should be noted that when sufficiently high voltage is applied to tissues, cells may undergo irreversible electroporation which creates permanent pores in the treated cell membranes. This process also releases fluids into the extracellular spaces and leads to tissue necrosis as do the RF and cryogenic therapies.
One drawback to impedance tomography is its lack of direct feedback to evaluate whether a lesion was successfully created to the desired transmurality, quality, or continuity. In particular, impedance measurements provide binary data regarding a particular lesion; either the tissue is viable or necrotic. Impedance measurements alone, however, do not provide real-time assessment of whether a cryogenic or RF lesion was successfully created to a desired lesion depth, in part, because different tissue levels have different impedances.
Tissue ablation technology often utilizes catheter tip temperature monitoring with feedback control to titrate energy delivery. The major limitation of this approach is that the catheter tip temperature and tissue temperatures are not the same. The catheter tip temperature is consistently lower than tissue temperature. The difference is variable and is dependent on the force of the catheter tissue contact that determines impedance as well as cooling of the catheter tip.
In view of the above, it would be desirable to provide improved methods of assessing tissue contact, lesion quality and depth, and other characteristics of cryogenically and/or RF treated tissue to determine the efficacy and resulting characteristics of the treatment.

Multi frequency and multi polarity complex impedance measurements to assess ablation lesions