The bottom hole assembly of the present invention includes a drill bit driven by a positive displacement drilling motor, the motor being constructed of tubular housings, one of said housings having a bend so as to cause the bit to drill directionally, another housing containing a rotor and stator to generate power, and a flexible section between the power generation housing and the bend. A stabilizer is disposed on one end of the flexible section for engaging the wall of the borehole and the housing with the bend includes a wear pad for engaging the lower side of the borehole. The bottom hole assembly contacts the borehole at three contact points, namely at the stabilizer, the wear pad, and the drill bit, for producing the necessary build-up rate, along with the bend, and thus the curvature of the borehole being drilled. The flexible section has a stiffness which is less than the stiffness of the housing of the stator and has a stiffness which is on the order of 33% or less of that of the power generation housing. The stiffness is determined by the selection of the material, wall thickness and length of the flexible section such that the desired flexibility is achieved, but the necessary torsional strength and axial load capabilities are maintained. The purpose of the flexible section is to allow the bottom hole assembly to be configured to achieve high build rates, on the order of 20 to 70 degrees per hundred feet, without generating excessively high loads and stresses on the bit and other bottom hole assembly components.

Directional control in most controlled-trajectory drilling is provided by two basic types of bottom hole assemblies: drilling motors and rotary assemblies. Rotary assemblies are used for maintaining the direction of a well-bore or for making minor changes in direction. Drilling motors are used for making rapid changes in direction. The positive displacement motor is a fluid-driven motor which turns the drill bit independently of drill string rotation. Examples of positive displacement motors are described in U.S. Pat. Nos. 4,059,165 and 4,679,638. The power of a positive displacement motor is generated by a power generation section that includes a rotor and stator which have helical lobes that mesh to form sealed helical cavities. When drilling fluid is pumped through the positive displacement motor, the fluid advancing through the cavities forces the rotor to rotate.
The rotor, which travels in an orbiting motion about the axis of the tool, is connected to either a flexible or articulated constant velocity coupling which transmits torque while eliminating the orbital motion. The coupling then transmits the torque to a driveshaft, which is housed in bearings to enable it to transmit both axial (i.e. "bit weight") and lateral loads from the drill string to the bit. A tandem motor may also be used which includes upper and lower power sections. Such a tandem motor is described in U.S. Pat. No. 5,620,056 issued Apr. 15, 1997, incorporated herein by reference.
A steerable motor, typically configured with a bend in the external housing and two or more stabilizers, is a positive displacement motor configured to operate as a two-mode system. In the "sliding" mode, the steerable motor is oriented by rotating the drill string, using measurement-while-drilling signals to determine toolface or bend orientation. Once the desired downhole toolface orientation is achieved, the drill string is then advanced without rotating, maintaining the desired toolface, using only the rotation generated by the positive displacement motor to drive the bit. The combination of stabilizers and bent housing generates a side load on the bit, causing it to drill in the toolface direction. Pads on the motor housing may be used instead of stabilizers. In the "rotating" mode, the entire motor is rotated, negating the effect of the bend, and its directional characteristics are determined by the size and placement of stabilizers.
FIG. 1 illustrates a simple well with a lateral borehole A. The kick-off point B is the beginning of the build section C. A build section is preferably performed at a constant build-up rate until the desired angle or end-of-build D is achieved. Build-up rate is normally expressed in terms of degrees-per-hundred-feet (deg/100'), which is simply the measured change in angle divided by the measured depth drilled.
The build section C is formed by the build-up rate of the positive displacement motor which creates lateral borehole A having a curvature with a radius. Conventional, or long radius boreholes typically are those with build-up rates between 1 and 8 degrees per 100 feet. Medium radius boreholes typically are those with build-up rates between 8 and 30 degrees per 100 feet and short radius boreholes typically are those with build-up rates over 60 degrees per 100 feet.
The build rate, or angle-changing capability of a motor, depends on the extent to which the combination of bend and stabilizers and/or pads cause the bit to be offset from the center line of a straight borehole. Increased bit offset results in higher build rate. Increased bit offset, however, results in increased side loads, as shown in FIG. 2, when kicking off or when the motor is rotated in the borehole. High bit side loads can cause damage to the gage or bearings of the bit, and limit motor life by causing driveshaft fatigue, radial bearing wear, and stator damage. Stabilizer loads and associated wear also increase.
Medium radius wells use many of the same bottom hole assembly components and well planning tools used in long radius wells. The key differences are that medium radius build rates place some limitations on the ability to rotate, and that these limitations can affect well profile. Medium radius wells may be broadly characterized by the following: the bottom hole assembly used to drill the build section cannot be rotated in that section (or at best, very limited rotation) and due to the hole curvature in the build, the component of drill pipe stress due to bending is high enough that either the stress component due to tension must be limited by well profile design or drill string rotation must be limited while in tension.
The definition of medium radius, like that of long radius, will vary with hole size. The following are approximate guidelines:
______________________________________ Hole Size Build Rate (Degrees/100') ______________________________________ 6" to 63/4" 12 to 25 81/2" 10 to 18 121/4" 8 to 14 ______________________________________
Since the motor used to drill the build section is not intended to be rotated, its configuration is somewhat different than that of a steerable motor. The stabilizers which give a steerable motor its rotating-mode directional tendencies are not needed, and in fact reduce the ability of the motor to slide, so they are typically not used. The first contact point of a medium radius bottom hole assembly is generally a pad or sleeve instead of a stabilizer, and is usually designed close to the bend to maximize the build rate capability.
Depending on hole curvature and bottom hole assembly design, it may be possible to alter the build rate while drilling in the build section without tripping for a bottom hole assembly change. As in long radius drilling, the bottom hole assembly is designed to build angle at a higher rate than necessary, then variations of steerable motor techniques are used to reduce the build rate. One method of reducing the build rate is to rotate the drill string very slowly, on the order of 1 to 10 RPM. This method is referred to as pigtailing because of the corkscrewed hole it would seem to produce. Another method, known as "rocking" or "wagging" toolface, is to orient left for some interval, then right for an equal interval. Both of these techniques can be used to make an aggressive angle-build bottom hole assembly drill a tangent-like trajectory, especially when viewed in the vertical plane. However, these practices may cause excessive stress in motor or measurement-while-drilling housings when passing through the high doglegs created.
Short radius wells may be generally characterized by the fact that hole curvature is so high that the bottom hole assembly must be articulated in order to pass through the build section. The following may be considered to define short radius:
______________________________________ Hole Size Radius (feet) Build Rate (degrees/100') Radius (feet) ______________________________________ 81/2" 48-88 120 to 65 6" to 63/4" 57-115 100 to 50 43/4" 64-143 90 to 40 33/4" 72-191 80 to 30 ______________________________________
The build rate of short radius wells is such that large diameter tubulars, such as motors or survey collars, must be articulated in order to pass through the build section. Articulations are knuckle joints or hinge points which transmit axial loads, but not bending moment. Bottom hole assembly components are shortened into lengths which will traverse through the build without interference. Without articulations, excessive bending stress and high side loads would result.
Since the articulated joints decouple bending moment from one section of the bottom hole assembly to another, the build rate of the steering section is unaffected by the stiffness or weight of the sections above it. Build rate is completely defined by the three contact points defined by the bit, the first stabilizer or pad, and the first articulation point. The overall length and offset of these components must be such that the assembly will pass through casing with a reasonable amount of force.
Bottom hole assembly modeling is used in medium radius boreholes to analyze forces on the bit and stabilizers, and bending stresses at connections and critical cross-section changes, with assemblies oriented in the model both highside and lowside. Bottom hole assembly modeling is utilized in well planning for predicting the capabilities and tendencies of each bottom hole assembly that is planned to be run. Bottom hole assembly modeling identifies the response of each bottom hole assembly to variation in operating parameters such as weight on bit, overgage or undergage hole, stabilizer wear, and formation tendencies.
Various types of directional prediction models exist, as are well known by one skilled in the art, but all are based on the principle that directional control is accomplished by applying forces to the bit that will cause the bit to drill in the desired direction. Two kinds of models are commonly used, equilibrium curvature models and "drill ahead" models. Equilibrium curvature models are static beam models which solve for the hole curvature in which all bending moments and forces on the beam are in equilibrium. A typical 2-dimensional model applies known loads (including weight-on-bit, buoyancy, and the weight of the bottom hole assembly itself) and derived loads (i.e. bit side loads due to formation anisotropy) to the bottom hole assembly components.
A gap in radius exists between the lower (in terms of build-up rate) limit of short radius and the upper limit of medium radius. This gap between medium and short radius build rates has become known as intermediate radius, typically considered to be in the range of 25 to 60 degrees per 100 feet. For a 6" to 63/4" hole size, for example, this range would be about 25 to 57 deg/100'. In the intermediate radius range, drill pipe rotation is acceptable, but conventional medium radius motors cannot achieve the necessary build rates. For conventional medium radius motors to achieve build rates in this intermediate range, extremely high bend angles have to be used. Such high bend angles produce so much bit interference with the casing that it is difficult or impossible to force the bottom hole assembly through the casing without damaging the bit. Also, at kickoff the bit side load would be so high the motor driveshaft would be in danger of breaking. If the kickoff could be initiated successfully, the bottom hole assembly tends to bind in the curve and has trouble sliding. Conventional bottom hole assemblies have other fundamental limitations in achieving a build rate for an intermediate radius well. Conventional bottom hole assemblies are relatively stiff and have a size which takes up most of the borehole. For example, a 43/4 downhole motor drills a 6 to 63/4 inch hole leaving little clearance for the bottom hole assembly. Because the bottom hole assembly is much stiffer than the drill string, the bottom hole assembly will only pass through a borehole with a maximum curvature without breaking one of its components. For a 43/4 motor, the stiffniess of the bottom hole assembly generally limits the build-up rate to 25 degrees per 100 feet to still be able to pass the bottom hole assembly and MWD collars through the curved borehole. There are also limitations on rotation in the borehole. The drill strings can be rotated through higher curvatures than can the bottom hole assemblies because the reduced diameter of the drill string causes it to be more flexible. The 31/2" drill string which is used with the 43/4" motor may be safely rotated through a build-up rate of up to 60 degrees per 100 feet.
There is a need to be able to drill intermediate radius wells without using special bottom hole assemblies. Drilling the short radius well limits the amount of drilling time and thus expense required for the borehole. However, drilling a short radius well instead of an intermediate radius well has disadvantages. In drilling a short radius well, there is the potential for the yielding of the drill string. Also, there is almost no production equipment, such as screens and liners, that can pass through and around bends greater than 60 deg/100'. This is possible in bends between 20 and 60 deg/100'. Thus, there are more production and completion options available in an intermediate radius well. Short radius wells require special drilling components. To allow bottom hole assemblies to pass through a short radius well having a build-up rate above 60 deg/100', the sections of the bottom hole assembly must be very short and articulated between the sections. The drill string cannot be rotated and is slid through the borehole. Articulated motors have also suffer from unpredictable build-up rates in this range, especially in unconsolidated formations.
Flexible members have been used with rotary drilling assemblies. U.S. Pat. No. 5,538,091 discloses a bottom hole assembly for connection to a drill string for use in directing the path of a drill bit while rotary drilling. The bottom hole assembly includes a modified cutting assembly, a stabilizer, and a flexible member interposed between the modified cutting assembly and stabilizer for drilling a predetermined portion of the hole. The modified cutting assembly may include a symmetric drill-bit assembly and a bent sub or a drill bit having cutters with a non-radially symmetric pattern. The flexible member is made of a material having a lower Young's modulus than steel and/or a member with a smaller wall thickness than the remainder of the bottom hole assembly. The flexible member may be provided by an aluminum drill collar or a composite material drill collar. Additionally, the flexible member may be an articulated member. That portion of the bottom hole assembly below the stabilizer is designed so that portion does not sag to the extent that it contacts the borehole wall when the drill string is inclined to vertical.
Further, it is known to place "compressive service" drill pipe or reduced diameter collars between the drilling assembly and drill collars to reduce stress on the drilling assembly. However, placing the flexible member above the collars relieves stress at the top of the motor but does not adequately relieve bit side loads. Placing the flexible member above the motor also does not have the desired effect of increasing build rates while preventing the motor from binding in the curved wellbore.
The bottom hole assembly of the present invention overcomes the deficiencies of the prior art.

Bottom hole assembly for directional drilling


Methods and apparatus for frequency tracking of a received signal. In an aspect, a method is provided wherein the received signal comprises one or more symbols having a periodic structure. The method comprises receiving a plurality of samples of a selected symbol that comprises pilot signals scrambled with data and determining a window size and a periodicity factor. The method also comprises accumulating a correlation between samples in a first window and samples in a second window to produce an accumulated correlation value, wherein the first and second windows have a size and a separation based on the window size and the periodicity factor, respectively, and deriving a frequency error estimate based on the accumulated correlation value.

1. Field
The present application relates generally to the transmission of information over a distribution network, and more particularly, to methods and apparatus for improved frequency tracking of a received signal.
2. Background
Data networks, such as wireless communication networks, have to trade off between services customized for a single terminal and services provided to a large number of terminals. For example, the distribution of multimedia content to a large number of resource limited portable devices (subscribers) is a complicated problem. Therefore, it is very important for network administrators, content retailers, and service providers to have a way to distribute content and/or other network services in a fast and efficient manner and in such a way as to increase bandwidth utilization and power efficiency.
In current content delivery/media distribution systems, real time and non real time services are packed into a transmission frame and delivered to devices on a network. For example, a communication network may utilize Orthogonal Frequency Division Multiplexing (OFDM) to provide communications between a network server and one or more mobile devices. This technology provides a transmission frame having data slots that are packed with services to be delivered over a distribution network as a transmit waveform.
Typically, the transmission frame is delivered over a network as a transmit waveform. Devices in communication with the network acquire and track the waveform so that the transmitted content can be recovered. Unfortunately, conventional systems may take some time to acquire and track the waveform. For example, if a residual frequency error at the end of time division multiplexed pilot signals provided for synchronization is high, then the data modulation may not be properly decoded. Hence it is very important that the frequency error and timing error be minimized at the receiver before the commencement of data demodulation.
Therefore it could be desirable to have a system that operates to quickly acquire and track the frequency and timing of a received waveform so that information encoded in the waveform can be accurately decoded.


The present invention relates to an image formation method and the apparatus thereof. An electrostatic latent image formed on a photosensitive body is developed with toner, and the developed toner image is electrostatically transferred onto a recording sheet held on a transfer drum; in repeating the process a plurality of images are formed on the recording sheet. The electric charge on the transfer drum is increased by repeating the electrostatic transfer of the toner image, which can cause a trouble; therefore each time an image formation is completed, the charge on the transfer drum is removed. When a part of the recording sheet held on the transfer body on which the toner image is previously formed faces the photosensitive body, the transfer body is controlled to be apart from the photosensitive drum not to disarrange the image which is previously formed on the recording sheet.

1. Field of the Invention
The present invention relates to an image formation method and the apparatus thereof and, in particular, to an image formation method for forming a plurality of images on a recording sheet and an image formation apparatus for executing the method.
2. Description of the Related Art
As an apparatus for forming a plurality of images on a recording sheet, for example, there is one disclosed in Japanese Patent Laid-open No. Sho 63-14177. The apparatus is so arranged that a plurality of images are formed in the rotary direction of a photosensitive body by exposing a rotating manuscript being held on a rotary manuscript drum, and also a plurality of images are formed in the width direction of the photosensitive body by providing a plurality of projection lenses in parallel. In the apparatus, however, a special constitution is needed and a manuscript size is also limited for copying. Furthermore, since the manuscript is held on the drum, it is impossible to form different kinds of images on a single recording sheet.
On the other hand, as an apparatus in which different images can be formed on a sheet, there is one disclosed in U.S. Pat. No. 4,771,319. In the apparatus, a first toner image formed on a photosensitive body is transferred onto the front half of a recording sheet and after fixing the sheet, the sheet is resupplied to a transfer portion for transferring a second toner image formed on the photosensitive body onto the rear half of the sheet. In the apparatus, however, each time the images are formed, the fixing processes have to be performed, which is a big burden for the recording sheet, and there is more of a probability of the occurrence of a jam. The recording sheet on which the images are formed is once housed in an intermediate tray and after that the sheet is resupplied, so that a quite long period of time is needed for copying a sheet of manuscript.

Image formation method and apparatus for forming a plurality of images in different positions on a recording sheet


The present invention features compounds able to modulate one or more activities of an inorganic ion receptor and methods for treating diseases or disorders using such compounds. Preferred compounds can mimic or block the effect of extracellular calcium on a cell surface calcium receptor.

The references provided herein are not admitted to be prior art to the claimed invention.
Certain cells in the body respond not only to chemical signals, but also to ions such as extracellular calcium ions (Ca.sup.2+). Extracellular Ca.sup.2+ is under tight homeostatic control and regulates various processes such as blood clotting, nerve and muscle excitability, and proper bone formation.
Calcium receptor proteins enable certain specialized cells to respond to changes in extracellular Ca.sup.2+, concentration. For example, extracellular Ca.sup.2+ inhibits the secretion of parathyroid hormone (PTH) from parathyroid cells, inhibits bone resorption by osteoclasts, and stimulates secretion of calcitonin from C-cells.
PTH is the principal endocrine factor regulating Ca.sup.2+ homeostasis in the blood and extracellular fluids. PTH, by acting on bone and kidney cells, increases the level of Ca.sup.2+ in the blood. This increase in extracellular Ca.sup.2+, then acts as a negative feedback signal, depressing PTH secretion. The reciprocal relationship between extracellular Ca.sup.2+ and PTH secretion forms an important mechanism maintaining bodily Ca.sup.2+ homeostasis.
Extracellular Ca.sup.2+ acts directly on parathyroid cells to regulate PTH secretion. The existence of a parathyroid cell surface protein which detects changes in extracellular Ca.sup.2+ has been confirmed. (Brown et al., Nature 366:574, 1993.) In parathyroid cells, this protein, the calcium receptor, acts as a receptor for extracellular Ca.sup.2+, detects changes in the ion concentration of extracellular Ca.sup.2+, and initiates a functional cellular response, PTH secretion.
Extracellular Ca.sup.2+ can exert effects on different cell functions, reviewed in Nemeth et al., Cell Calcium 11:319, 1990. The role of extracellular Ca.sup.2+ in parafollicular (C-cells) and parathyroid cells is discussed in Nemeth, Cell Calcium 11:323, 1990. These cells were shown to express similar calcium receptors. (See Brown et al., Nature 366:574, 1993; Mithal et al., J. Bone Miner. Res. 9, Suppl. 1, s282, 1994; Rogers et al., J. Bone Miner. Res. 9, Suppl, 1, s409, 1994; Garrett et al., Endocrinology 136:5202-5211, 1995.)
The ability of various molecules to mimic extracellular Ca.sup.2+ in vitro is discussed in references such as Nemeth et al., in "Calcium-Binding Proteins in Health and Disease," 1987, Academic Press, Inc., pp. 33-35; Brown et al., Endocrinology 128:3047, 1991; Chen et al., J. Bone Miner. Res. 5:581, 1990; and Zaidi et al., Biochem. Biophys. Res. Commun. 167:807, 1990.
Nemeth et al., PCT/US92/07175, International Publication Number WO 93/04373, Nemeth et al., PCT/US93/01642, International Publication Number WO 94/18959, and Nemeth et al., PCT/US94/12117, International Publication Number WO 95/11211, describe various compounds which can modulate the effect of an inorganic ion receptor.


A method of fabricating a liquid crystal display device includes forming an active pattern and a data line on a substrate, forming a first insulating layer on the data line, forming a second insulating layer on the substrate, forming a gate electrode on the second insulating layer above the active pattern, forming a third insulating layer on the substrate, forming first and second contact holes through the second and third insulating layers to expose first and second portions of the active pattern, and forming a third contact hole through the first, second, and third insulating layers exposing a portion of the data line, respectively, and forming source and drain electrodes on the third insulating layer, the source electrode connected to the first exposed portion of the active pattern through the first contact hole and connected to the first exposed portion of the data line through the third contact hole, and the drain electrode connected to the second exposed portion of the active pattern through the second contact hole.

1. Field of the Invention
The present invention relates to a display device and a method of fabricating a display device, and more particularly, to a liquid crystal display (LCD) device and a method of fabrication an LCD device.
2. Description of the Related Art
As the need for visual display devices increases, requirements for improved display devices having low power consumption, thin profiles, light weight, and high image quality has increased. One example of an improved display device is an LCD device that is suitable for mass-production. Accordingly, the LCD device has been developed to replace conventional cathode ray tube (CRT) devices.
In general, an LCD device displays images by adjusting light transmittance ratios of liquid crystal cells by respectively supplying data signals according to image information to the liquid crystal cells arranged as a matrix configuration. Accordingly, the LCD device includes a color filter substrate, an array substrate, and a liquid crystal material layer formed between the color filter and array substrates. In addition, a thin film transistor (TFT) is commonly used as a switching device of the LCD device, wherein the TFT includes one of amorphous or polycrystalline silicon as a channel layer.
During fabrication of the LCD device, a great number of mask processes (that is, a photolithography process) are required to fabricate the array substrate including the thin film transistor. Thus, to more efficiently produce LCD devices, there is a need to reduce the number of the mask processes.
FIG. 1 is a partial plan view of an array substrate for an LCD device according to the related art. In FIG. 1, a plurality of gate lines 16 and data lines 17 are arranged on an array substrate 10 along first and second directions, respectively, to define a plurality of pixel regions. In addition, a thin film transistor (TFT) is formed at each crossing of the gate and data lines 16 and 17 and a pixel electrode 18 is formed at each of the pixel regions.
The TFT includes a gate electrode 21 connected to the gate line 16, a source electrode 22 connected to the data line 17, and a drain electrode 23 connected to the pixel electrode 18. In addition, although not shown, the TFT includes first and second insulating layers for insulating the gate electrode 21 and the source/drain electrodes 22 and 23. Furthermore, the TFT includes an active layer 24 that includes a conductive channel between the source electrode 22 and the drain electrode 23 by application of a gate voltage to the gate electrode 21.
In FIG. 1, the source electrode 22 is electrically connected to a source region of the active layer 24 through a first contact hole 40a formed on the insulating layers (not shown), and the drain electrode 23 is electrically connected to a drain region of the active layer 24 through the first contact hole 40a. Although not shown, a third insulating layer is provided with a second contact hole 40b formed on the drain electrode 23, wherein the drain electrode 23 and the pixel electrode 18 are electrically connected to each other through the second contact hole 40b.
Hereinafter, a fabrication process of a general liquid crystal display device will be described in more detail with reference to FIGS. 2A to 2F.
FIGS. 2A to 2F are cross sectional views along I–I′ of FIG. 1 of a method for fabricating an LCD device according to the related art. In FIG. 2A, an active pattern 24 composed of a polycrystalline silicon layer is formed on the substrate 10 using a photolithographic process.
In FIG. 2B, a first insulating layer 15a and a conductive metal layer are sequentially deposited along an entire surface of the substrate 10 where the active pattern 24 is formed. Then, the conductive metal material is patterned by using a photolithographic process; thereby forming a gate electrode 21 on the active pattern 24 with the first insulating layer 15a interposed therebetween. Next, high concentration impurity ions are injected into predetermined regions of the active pattern 24 using the gate electrode 21 as a mask, thereby forming p+ or n+ type source/drain regions 24a and 24b.
In FIG. 2C, a second insulating layer 15b is deposited along an entire surface of the substrate 10 where the gate electrode 21 is formed, and the second and first insulating layers 15b and 15a are partially removed by a photolithographic process, thereby forming first contact holes 40a that partially expose the source/drain regions 24a and 24b.
In FIG. 2D, a conductive metal material is deposited along an entire surface of the substrate 10 and a photolithographic process is performed to forming a source electrode 22 connected to the source region 24a and a drain electrode 23 connected to the drain region 24b through the first contact hole 40a. In addition, a portion of the conductive metal layer constituting the source electrode 22 is extended along one direction to form a data line 17.
In FIG. 2E, a third insulating layer 15c is deposited along an entire surface of the substrate 10, and a second contact hole 40b is formed by a photolithographic process to expose a part of the drain electrode 23.
In FIG. 2F, a transparent conductive material is deposited along an entire surface of the substrate 10 where the third insulating layer 15c is formed, and a pixel electrode 18 connected to the drain electrode 23 through the second contact hole 40b is formed by a photolithographic process.
During the fabrication method of the LCD device, at least six separate photolithographic processes are required to pattern the active pattern, the gate electrode, the first contact hole, the source/drain electrode, the second contact hole, and the pixel electrode. Each of the six photolithographic processes includes a series of processes for forming a desired pattern by transferring a pattern formed on a mask onto a substrate where a thin film is deposited. Then, a plurality of processes including photoresist deposition, light exposure, and a development process are performed. Accordingly, these photolithographic processes reduce production yield and may generate defects during formation of the TFT. In addition, since masks for forming the various patterns are very expensive, when the number of masks used during the fabrication processes increases, fabrication costs of the LCD device proportionally increases.

Liquid crystal display device and method of fabricating the same


A shared register row is provided between a program-based circuit simulator and a device-based circuit simulator. The shared register row includes a plurality of shared registers each corresponding to signals transmitted between the program-based and device-based circuit simulators. By mutually accessing a shared register corresponding to a signal from the program-based and device-based circuit simulators, the signal is transferred via the corresponding shared register with synchronization between the program-based and device-based circuit simulators.

1. Field of the Invention
The present invention relates to a verification technique for a logic circuit, and particularly relates to a method and system for verifying whether a given logic circuit to be verified properly operates, by creating an operation simulation device for the logic circuit, virtually inputting signals to the simulation device, and checking its outputs against respective expected values.
2. Description of the Related Art
Logic verification systems generally used for verification of logic circuits are composed of a software simulator for simulating a portion of a logic circuit by executing a program on a computer, a hardware emulator for emulating another portion of the logic circuit by using a reconfigurable device, and buffer memory for absorbing the difference in processing speed between the software simulator and the hardware emulator to synchronize them.
For example, a circuit verification system is disclosed in Japanese Laid-open Patent Application No. 2000-215226 (paragraphs 0046 through 0052 and FIGS. 1 and 2) wherein the circuit to be verified is divided into a first portion verified by a hardware emulator and a second portion verified by a software simulator, the clocks of the hardware emulator and the software emulator are synchronized via a communication device, and mutual transfer of data is performed.
Similarly, in U.S. Pat. No. 5,546,562 and Kudlugi et al. (Murali Kudlugi, Soha Hassoun, Charles Selvidge, Duaine Pryor, "A Transaction-based Unified Simulation/Emulation Architecture for Functional Verification," IEEE Design Automation Conference, 2001, pp. 623-628), FIFO (first-in first-out) memory is provided between a simulator and an emulator, and a signal transmitted from the simulator reaches the emulator via several steps through the FIFO memory. Transmission from the emulator to the simulator on the computer is also performed via FIFO memory in the same manner.
However, the signal transmitted between the hardware emulator and the software simulator passes through the FIFO memory or buffer memory, so there is a possibility that values can vary despite attempting to reference a specific signal value simultaneously from the emulator and the simulator. In other words, strictly speaking, a temporal displacement in processing inevitably occurs between the hardware emulator and the software simulator. Accordingly, when a combination of a computer program and a reconfigurable device is considered as the simulated structure of the logic circuit, the simulated structure and the logic circuit to be verified cannot be said to have exactly the same structure, and the accuracy thereof as a simulation device is low.

Verification method and system for logic circuit


A positive resist composition is provided comprising two onium salts, a base polymer comprising acid labile group-containing recurring units, and an organic solvent. The positive resist composition forms a pattern having PED stability and improved properties including DOF, LWR, and controlled footing profile.

In the recent drive for higher integration and operating speeds of LSI and memory devices, the pattern rule is made drastically finer. The photolithography which is currently on widespread use in the art is approaching the essential limit of resolution determined by the wavelength of a light source.
As the light source used in the lithography for resist pattern formation, g-line (436 nm) or i-line (365 nm) from a mercury lamp was widely used in 1980's. Reducing the wavelength of exposure light was believed effective as the means for further reducing the feature size. For the mass production process of 64 MB dynamic random access memories (DRAM, processing feature size 0.25 μm or less) in 1990's and later ones, the exposure light source of i-line (365 nm) was replaced by a KrF excimer laser having a shorter wavelength of 248 nm.
However, for the fabrication of DRAM with a degree of integration of 256 MB and 1 GB or more requiring a finer patterning technology (processing feature size 0.2 μm or less), a shorter wavelength light source was required. Over the decades, photolithography using ArF excimer laser light (193 nm) has been under active investigation. It was expected at the initial that the ArF lithography would be applied to the fabrication of 180-nm node devices. However, the KrF excimer lithography survived to the mass-scale fabrication of 130-nm node devices. So, the full application of ArF lithography started from the 90-nm node. The ArF lithography combined with a lens having an increased numerical aperture (NA) of 0.9 is considered to comply with 65-nm node devices. For the next 45-nm node devices which required a father reduction of exposure light wavelength, the F2 lithography of 157 nm wavelength became a candidate. However, for the reasons that the projection lens uses a large amount of expensive CaF2 single crystal, the scanner thus becomes expensive, hard pellicles are introduced due to the extremely low durability of soft pellicles, the optical system must be accordingly altered, and the etch resistance of resist is low; the development of F2 lithography was stopped and instead, the ArF immersion lithography was introduced. See Non-Patent Document 1.
In the ArF immersion lithography which has been commercially implemented over the decade, exposure is performed while the space between the projection lens and the wafer is filled with water having a refractive index of 1.44. As compared with the conventional ArF lithography wherein the space between the projection lens and the wafer is filled with air having a refractive index of 1, the ArF immersion lithography enables high resolution exposure because the incident angle of exposure light onto the wafer is mitigated to provide a high NA of at least 1.
One candidate for the 32-nm node lithography is lithography using extreme ultraviolet (EUV) radiation with wavelength 13.5 nm. The EUV lithography has many accumulative problems to be overcome, including high power laser, high sensitivity, high resolution and minimized edge roughness (LER, LWR) of resist film, defect-free MoSi laminate mask, low aberration reflection mirror, pellicle, and the like.
Another candidate for the 32-nm node lithography is high refractive index immersion lithography. The development of this technology was stopped because lutetium aluminum garnet (LuAG), a high refractive index lens candidate had a low transmittance and the refractive index of liquid did not reach the goal of 1.8.
The process that now draws attention under the above-discussed circumstances is a double patterning process involving a first set of exposure and development to form a first pattern and a second set of exposure and development to form pattern features just between the first pattern features. A number of double patterning processes are proposed. One exemplary process involves a first set of exposure and development to form a photoresist pattern having lines and spaces at intervals of 1:3, processing the underlying layer of hard mask by dry etching, applying another layer of hard mask thereon, a second set of exposure and development of a photoresist film to form a line pattern in the spaces of the first exposure, and processing the hard mask by dry etching, thereby forming a line-and-space pattern at a half pitch of the first pattern. An alternative process involves a first set of exposure and development to form a photoresist pattern having spaces and lines at intervals of 1:3, processing the underlying layer of hard mask by dry etching, applying a photoresist layer thereon, a second set of exposure and development to form a second space pattern on the remaining hard mask portion, and processing the hard mask by dry etching. In either process, the hard mask is processed by two dry etchings.
In the litho-litho-etch (LLE) double patterning technology including patterning by first exposure and subsequent patterning by second exposure, the development of the first photoresist pattern is eliminated or postponed, and development is first performed after the second pattern formation. While the double patterning technology suffers from the problem of increased manufacturing cost due to the complication of the process, the LLE double patterning technology is attractive in that pattern formation is possible through a few steps.
The problem of LLE arises from a lapse of time between first exposure and post-exposure bake (PEB) because second exposure must be interposed therebetween. During the time lapse, the generated acid causes excessive progress of reaction within the resist film or reacts with airborne impurities (e.g., amine compounds) so that it is deactivated. This prohibits resist pattern formation or invites sensitivity changes. To overcome such problems, the resist composition must have post-exposure delay stability (PED stability). It is noted that the PED stability refers to stability to the phenomenon that during the time delay between exposure and PEB, the excessive progress of reaction within the resist film caused by the generated acid or the deactivation of the generated acid by reaction with airborne impurities can prohibit resist pattern formation or invite sensitivity changes.
Under the circumstance where miniaturization of the pattern rule is required in the recent demand for higher integration and operating speeds of LSI and memory devices, it is important to reduce not only the cell area, but also the area of a peripheral circuit. To this end, miniaturization of a two-dimensional pattern that constitutes the peripheral region is required. In turn, the resist composition is required to meet such properties as DOF, LWR, and controlled footing of pattern profile.
For the purpose of solving the above problems, studies are made on photoacid generators. PAGs commonly used in ArF lithography chemically amplified resist compositions are triphenylsulfonium salts which remain stable in resist compositions, as disclosed in Patent Document 1. Since the triphenylsulfonium salts, however, are absorptive at the wavelength (193 nm) of the ArF lithography, there are drawbacks such as reduced transmittance of resist film and low resolution. To achieve a high sensitivity and resolution, 4-alkoxynaphthyl-1-tetrahydrothiophenium cations were developed. To comply with the recent advance of miniaturization. Patent Document 2 discloses a resist composition for the ArF immersion lithography comprising an onium salt of 4-alkoxynaphthyl-1-tetrahydrothiophenium cation and a resin having an acid labile group. Yet there is not available a resist composition capable of meeting such properties as DOF, LWR, and controlled footing of pattern profile as well as PED stability.
For the purpose of solving the above problems, studies are also made on quenchers. As the quencher, not only amine compounds, but also weak acid onium salts are reported. For example, Patent Document 3 describes a positive photosensitive composition for the ArF excimer laser lithography comprising an onium salt of carboxylic acid. This is based on the mechanism that a salt exchange takes place between the weak acid onium salt and a strong acid (sulfonic acid) which is generated from another PAG upon exposure, so that the strong acid having high acidity (α,α-difluorosulfonic acid) is converted to weak acid (alkanesulfonic acid or carboxylic acid), for thereby suppressing acid-aided decomposition reaction of acid labile groups and reducing or controlling the acid diffusion distance. For enhancing the acid diffusion controlling effect, Patent Document 4 discloses a weak acid onium salt having a nitrogen-containing anion.
With the latest further advance of miniaturization, even a resist composition comprising a weak acid onium salt still fails to meet such properties for the ArF immersion lithography as DOF, LWR, and controlled footing of pattern profile as well as PED stability.
Patent Document 5 discloses a resist composition comprising two acid generators having different acidity. This resist composition still fails to meet DOF, controlled footing and PED stability.

Positive resist composition and patterning process


A milling apparatus for forming a key bit includes a base, and a key holding member positioned in front of the base. The key holding member includes an upper clamping plate and a lower clamping plate, which are adapted to clamp a key blank therebetween. A carrier is mounted movably on the base. A hollow body is mounted slidably on the carrier, and has an interior chamber and a concave front face unit which is formed with a cross groove. The cross groove has a vertical section and a horizontal section which is adapted to be aligned with the key blank that is clamped between the upper and lower clamping plates of the key holding member. A milling cutter is mounted rotatably within the interior chamber in the hollow body, and extends into the vertical section of the cross groove in the front face unit of the hollow body. A resilient unit biases the concave front face unit of the hollow body to contact the upper and lower clamping plates of the key holding member, thereby locating the upper and lower clamping plates on two sides of the horizontal section of the cross groove. A waste collector is adapted to suck metal waste from the interior chamber.

1. Field of the Invention
This invention relates to a milling apparatus for forming a key bit, and more particularly to a milling apparatus which can prevent metal waste from flying out of the milling apparatus.
2. Description of the Related Art
Referring to FIGS. 1 to 3, a conventional milling apparatus for forming a key bit 1 is shown to include a base 11, a carrier 12 mounted movably on the base 11, and a hollow body 13 which is fixed on the carrier 12. The hollow body 13 has an interior chamber 130, in which a milling cutter 14 is mounted rotatably. A waste collector 15 is coupled with the hollow body 13 to suck metal waste created in the interior chamber 130 in the hollow body 13. A key holding member 16 is positioned in front of the base 11, and has an upper clamping plate 161 and a lower clamping plate 162, which are adapted to clamp a key blank 2 therebetween. Two opposed pushing merrbers 131 are provided on the hollow body 13, and are biased respectively by two comoression springs 132 to press against the upper and lower clamping plates 161, 162.
In operation, the carrier 12 is moved on the base 11 from the position shown in FIG. 1 to that in FIG. 2, thereby pressing the pushing members 131 against the key holding member 16. Then, the hollow body 13 is moved from the position indicated by solid lines in FIG. 3 to that indicated by phantom lines in FIG. 3 to form a specific-shaped key bit on the key blank 2. As best shown in FIG. 3, during the milling process, a clearance 17 is formed between the hollow body 13 and the key holding member 16. As a result, metal waste created from the key blank 2 fly out of the apparatus via the clearance 17, and cannot be sucked entirely into the waste collector 15. Furthermore, as illustrated, one of the pushing members 131 may separate from the key holding member 16, thereby affecting adversely the quality of the product and even damaging the milling cutter 14.


It is intended to identify and provide a novel carnitine transporter gene participating in carnitine transport in the testis and epididymis and carnitine transporter which is a protein encoded by the gene. A protein comprising the amino acid sequence represented by SEQ ID NO:2 or an amino acid sequence derived therefrom by deletion, substitution or addition of one to several amino acids and being capable of transporting carnitine or its analog; and a gene encoding this protein.

Carnitine has an important function in beta-oxidation of fatty acids in every organ of a living body. Cells in every organ produce ATP (adenosine triphosphate), which is the energy source for the cells, in mitochondria owing to the beta-oxidation of fatty acids. An acyl group of the fatty acids is transported in the mitochondria through a carnitine action to be transformed into acyl Co-A, and then the acyl Co-A is beta-oxidized to generate ATP. Many carnitines are diet-induced, and, though a part thereof is biosynthesized in the liver and the brain, almost all the cells need to uptake carnitines from outside; therefore, it has been assumed that a carnitine-specific transporter exists in the cell membrane according to past physiological studies.
Studies have been conducted on the carnitine uptake by various cells by the use of experiment systems employing the removed organ perfusion method or the isolated cell membrane vesicular system. However, it has been difficult to analyze the system of carnitine transport through cell membrane in detail by the conventional methods, and there has been a demand for isolation and analysis of the transporter itself.
The rat CT1 (Sekine, T. et al., Biochem. Biophis. Res. Commun., Vol. 251, pp. 586-591, 1998) has been isolated as the carnitine transporter. The hOCTN2 (Tamai, I. et al., J. Biol. Chem., Vol. 273, pp. 20378-20382, 1998) has been reported to be a human homologous gene of the CT1. The carnitine transporters are widely distributed in organs of the whole body to contribute to the carnitine uptake by various cells. They exist also in the kidney to carry out a function of reabsorption of carnitine from the renal tubules.
According to the past studies, it has been clarified that a carnitine concentration in the testis and the epididymis is the highest in the living body and reached the 2,000 times of the serum level depending on the specie of the carnitine. Since the duct of epididymis is an organ governing nutrition and maturity of sperms, the relationship between carnitine and sperm function has attracted attention.
It has been clarified that the sperms produced in the testis are premature and low in motility and lacks in fertilizability at that stage. The sperms leaving the testis move to the epididymis and subjected to various modifications therein and matured. Further, flagellar movement is necessary for the sperm fertility, which requires enormous energy. It is reasonable to consider that a large amount of carnitine is required for the production of ATP which is the energy source for the flagellar movement.
Actually, a study revealing a positive relationship between the carnitine concentration in the human semen and the number and motility of sperms has been reported. Also, in the clinical medicine, it has been reported that carnitine administration had resulted in an increase in fertilization probability of idiopathic infertility patients.
Thus, the carnitine transport specific to the testis and the epididymis has been considered to have an important function in the maturity and the fertilizability of sperms and has been studied by the experiment systems employing the removed organ perfusion method or the isolated cell membrane vesicular system. Though the existence of an active carnitine transport system has been clarified from the studies, its molecular substance has been indefinite.
Organic anion transporters OAT1 (organic anion transporter 1) (Sekine, T. et al., J. Biol. Chem., Vol. 272, pp. 18526-18529, 1997), OAT2 (Sekine, T., FEBS letter, Vol. 429, pp. 179-182, 1998), OAT3 (Kusuhara, H. et al., J. Biol. Chem., Vol. 274, pp. 13675-13680, 1999), and OAT4 (Cha, S. H. et al., J. Biol. Chem., Vol. 275, pp. 4507-4512, 2000), which have the central role in drug transport in the kidney, liver, brain, and placenta, have been isolated and reported by some of the inventors of the present invention. These transporters belonging to an OAT family are transporters that can transport many different organic anions in chemical structure and also transport of various anionic drugs.
Recently, an OCT (organic cation transporter) family which recognizes organic cations also has recently been identified. Since carnitine is an organic ion having both of a positive charge and a negative charge, it is assumed that the carnitine transporter is positioned between the OAT family and the OCT family from the point of molecular evolution.
In view of these facts, the present inventors have presumed that the carnitine transporter specific to the testis and the epididymis belongs to the organic ion transporter family.

Method of modulating a testicular carnitine transporter


The present invention provides a method of rejuvenating human skin by implanting a sheet formed of a pliable biocompatible material beneath the skin surface so as to generate a substantially smooth layer that augments a thickness of the skin portion. The biocompatible sheet has preferably a thickness sufficient for substantially camouflaging the underlying anatomical structure (e.g., veins and tendons).

The present invention relates generally to methods of enhancing the appearance of a patient's skin, and more particularly to methods for cosmetic rejuvenation of a patient's hand.
A variety of cosmetic surgical procedures are routinely performed on the face and body. Some examples of these procedures include facial rejuvenation, body contouring and nasal surgery. Further, a number of surgical techniques are known for reducing signs of aging exhibited by a person's hands. In one such technique, a quantity of lipid tissue can be injected under the skin surface of an aging hand to enhance its appearance. Such a procedure can, however, have a number of shortcomings. The injected lipid can resorb over time, thereby reducing the effectiveness of the treatment. Further, the outcome of such a procedure can be somewhat unpredictable.
Hence, there is a need for improved techniques for enhancing the appearance of aging in an individual's hands.


A base film for a magnetic recording medium including one surface, on which a magnetic layer can be formed, having a surface roughness of center line average roughness Ra of 10 nm or less, a ten-point average roughness Rz of 80 nm or less and a maximum height Rmax of 150 nm or less. The base film includes the other surface having a surface roughness of center line average roughness Ra of 4.5 to 20 nm, a ten-point average roughness Rz of 35 to 350 nm and a maximum height Rmax of 40 to 400 nm.

1. Field of the Invention
This invention relates to a base film for use in a so-called vacuum-deposited magnetic tape, and a magnetic recording medium using the base film.
2. Prior Art
As a high density magnetic recording medium, there is known a magnetic recording medium composed of a non-magnetic support and a ferromagnetic metal thin film formed thereon by physical deposition, such as vacuum deposition or sputtering, or plating.
For example, a magnetic tape on which cobalt (Co) is deposited is disclosed in Japanese patent application laid-open publication No. 147,010/79, and a perpendicular magnetic recording medium using an alloy of cobalt and chromium (Cr) is disclosed in Japanese patent application laid-open publication No. 134,706/77.
The thin film formed by the thin-film formation method, such as vacuum deposition, sputtering or ion plating, is as thin as 1.5 .mu.m or less, and in spite of its thinness, it has magnetic characteristics similar to or higher than those of a coating type magnetic recording medium provided with a magnetic recording layer having a thickness of 3 .mu.m or more. The coating type magnetic recording medium is composed of a base film and a magnetic layer coated on the base film and formed of a mixture of magnetic powder and an organic polymer binder.
In addition, there is the idea that magnetic characteristics such as Hc (coercive force) or remanence ratio of a hysteresis loop doesn't depend on the surface conditions of the base film. As an example of this idea, U.S. Pat. No. 3,787,327 revealed multi-layer structure of Co--Cr formed by vacuum deposition.
On the other hand, a metal thin film magnetic recording medium has such a disadvantage that roughness (surface irregularities) of the base film appears on a metal thin film having an extremely thin thickness, resulting in producing noise upon information reproduction.
In preventing the production of noise, it is desirable that the base film have a surface as smooth as possible. On the other hand, from the aspect of handling, such as winding and unwinding of the base film, the surface of the base film should be rough to some extent since an exceedingly smooth surface of the base film causes deterioration of performance in terms of slippage between adjacent portions thereof, resulting in occurrence of so-called blocking which makes it impossible to use it as a commercial product. Accordingly, the surface of the base film is required to have a certain roughness.
As mentioned above, in a metal thin film-type magnetic recording medium, the smooth surface of the base film is required from the aspect of electromagnetic transducing characteristics. On the other hand, the rough surface is required from the aspect of handling. In the end, the above-mentioned base film must satisfy these two contradictory characteristics.
Further, in the metal thin film magnetic recording medium, travelling ability of the surface on a metal thin film side is important in a practical use. In the case of the coating type magnetic recording medium, for example, the travelling ability is improved by adding a lubricant in a binder. However, such countermeasures are not applicable to a metal thin film magnetic medium. It is, therefore, much difficult to keep a stable travelling ability, and particularly, extremely difficult under high-temperature and high-humidity conditions.
In order to solve the problem, it has been proposed that fine projections be formed on the surface of a base film by employing a fine powder, water-soluble resin and silane coupling agents, as disclosed in Japanese patent laid-open patent publication No. 30,105/87. It has been also proposed that fine projections be formed on the surface of a base film by employing a fine powder and water-soluble resin, as disclosed in Japanese patent application laid-open publications Nos. 30,106/87 and 229,316/84.
As mentioned above, the roughness of the base film surface on which a magnetic layer can be formed is controlled in order to optimize the roughness of the surface of a metal thin film. However, the surface on the other side (the so-called back surface) has not been considered since it is the surface on which the magnetic layer can be formed that has been of primary concern. A surface having a center line average roughness Ra of approximately 4 nm, a ten-point average roughness of approximately 30 nm and a maximum height Rmax of 40 nm is usually considered "a relatively good surface" for the back surface only to prevent the back surface from suffering from deterioration by heat. Heat deterioration, here, means damage and deformation of a base film caused by the heat produced during the formation of a magnetic metal thin film by vacuum deposition. This is because, for example, in the case of applying vacuum deposition, a magnetic metal beam which is produced by the evaporation of magnetic metals is applied.
The roughness of the back surface, which contacts a guide roll in the production process of the film and the magnetic recording medium, largely influences travelling ability. Further, in the case of the above-mentioned relatively good surface, the travelling ability becomes unstable resulting in an increase in production costs of both the base film and magnetic recording medium.

Base film for magnetic recording medium and magnetic recording medium using same


A trash can assembly has a shell having an enclosing wall that defines a periphery. The assembly has a lid fitted over the top of the shell, and a foot pedal positioned adjacent the bottom of the shell, with a portion of the foot pedal positioned inside the periphery of the shell. The assembly also includes a link assembly coupling the foot pedal and the lid. The assembly can also include a liner defining a container body, the liner fitted inside the shell and having an indent provided on the container body. A handle mechanism has a link strip that has a hooked end, with the hooked end engaging the indent to lift the liner from inside the shell.

1. Field of the Invention
The present invention relates to household items, and in particular, to a trash can assembly that incorporates a number of improvements and enhancements.
2. Description of the Prior Art
A major concern for both the home and the workplace is containing and holding wastes, refuse, and trash until permanent disposal. Trash cans act as containers for holding ttrash and other wastes that are produced in any typical home or office. Trash and garbage cans often employ lids and covers to contain the trash and its associated odor, to hide the trash from view, and to prevent the trash from contaminating areas beyond the lid.
Conventional trash cans have been improved over the years to make them more user-friendly, sanitary, and hygienic. For example, many trash cans are now provided with a foot pedal positioned adjacent the base of the trash can so that a user can step on the foot pedal to open the lid of the trash can, thereby freeing up the user's hands to toss trash, or to change the plastic liner or bag that is used to line the trash can. Other trash cans have even provided an interior metal or plastic liner that fits inside the trash can, and which can be removed to be washed. However, these conventional trash cans still suffer from a number of drawbacks.
For example, the foot pedals on some of the conventional trash cans (e.g., such as shown in U.S. Pat. No. 6,010,024) are positioned awkwardly in that they extend a considerable distance from the body of the trash can to provide a sufficiently large surface area for the user's foot, and also to provide sufficient leverage for the user to step on and pivot the foot pedal. Unfortunately, such outwardly-extending foot pedals are prone to being inadvertently kicked by people as they walk around the vicinity of the trash can.
Other problems are associated with the internal liner. In conventional trash cans, the user typically needs to remove the liner from the trash can to dispose of the contents therein. To do so, the user typically lifts the liner from the trash can, and this may result in the user gripping portions of the interior of the liner, so that the user's fingers may come into contact with dirt, germs or trash items.
An additional problem relates to the fact that the wastes placed within such a container may produce odors, smells, and other harmful gases. Inevitably, the lid will need to be opened to deposit the waste, thereby allowing the odors and smells to escape from the trash can. Odors and smells may also escape from the trash can even when the lid is closed because some lids do not provide a tight seal with the trash can container.
Thus, there remains a need for a trash can that overcomes the drawbacks identified above.

This patent is subject to a terminal disclaimer.

Trash can assembly and improvements thereto


An optical head cleaning cartridge is adapted for use in an optical disk unit which includes an optical head located at a predetermined position in a specific operation mode of the optical disk unit and which uses the optical head to record information signals on and/or reproduce information signals from an optical disk which is accommodated within a standard type optical disk cartridge which is in conformance with a predetermined standard when loaded with the standard type optical disk cartridge. The optical head cleaning cartridge includes a first part having a size and a shape which are approximately the same as those of the standard type optical disk cartridge, a cleaning element provided at a position of the first part to confront the optical head when the optical head cleaning cartridge is loaded into the optical disk unit in the specific operation mode, a second part, connected to the first part, and including a driving part located at a position to allow manipulation thereof, and a transmitting mechanism, provided in the first and second parts, for transmitting power of the driving part to the cleaning element. The cleaning element cleans the optical head by rotating in response to the power of the driving part received via the transmitting mechanism.

The present invention generally relates to optical head cleaning cartridges, and more particularly to an optical head cleaning cartridge which can clean an optical head of an optical disk unit by a simple operation.
An optical disk unit is provided with an optical head having an optical system which includes an objective lens, a prism and the like. Information signals are recorded on and/or reproduced from an optical disk by moving the optical head in a radial direction of the optical disk. The optical disk is accommodated within a protection cartridge, and the optical head scans the optical disk via a window which is provided in the cartridge.
The objective lens of the optical head confronts a recording surface of the optical disk and is exposed via an opening of the optical head. For this reason, dust or dirt inevitably adheres on the objective lens. If dust or dirt adheres on the objective lens, the recording and/or reproducing characteristic of the optical disk deteriorates.
Conventionally, when dust or dirt adheres on the objective lens, an outer cover of the optical disk unit is removed, and in some cases, circuit boards or the like are removed, to expose the objective lens. The surface of the exposed objective lens is cleaned by a cotton stick which holds alcohol or the like. After the surface of the objective lens is cleaned, the circuit boards or the like are mounted back to the original positions, and the outer cover is thereafter secured in place.
Accordingly, parts of the optical disk unit which are assembled in a complex manner with a high precision must conventionally be taken apart in order to clean the objective lens, and there is a problem in that the high-precision parts may be damaged during the taking apart or reassembling thereof. In addition, it is virtually impossible for the common user to carry out the above described cleaning of the objective lens, and there is a problem in that a serviceman (maintenance person) must make a trip to clean the objective lens. Furthermore, because the serviceman must make the trip to clean the objective lens, there also are problems in that considerable time, labor and cost are involved in the cleaning of the objective lens.


A Pt film (24), a PLZT film (25), and a top electrode film (26) are formed above a semiconductor substrate (11). Next, the top electrode film (26) is patterned. Then, a PLZT film (27) covering an exposed portion of the PLZT film (25) is formed as an evaporation preventing film. Then, heat treatment is performed in an oxidative atmosphere to recover damage sustained to the PLZT film (25). Heat treatment is not performed between patterning of the top electrode film (26) and formation of the PLZT film (27). Thereafter, a ferroelectric capacitor is formed by patterning the PLZT film (25) and the Pt film (24).

In recent years, as digital technology has progressed, it has become increasingly common to process or store large amount of data at high speed. Accordingly, there is demand for highly integrated, high performance semiconductor device for use in electronic devices.
Accordingly, in order to realize high integration of semiconductor storage devices (DRAM), extensive research and development have been carried out for a technology using a ferroelectric material or a high dielectric constant material instead of a silicon oxide or a silicic acid nitride as a capacitor insulating film of a capacitor element constituting DRAM.
Furthermore, in order to realize a non-volatile RAM which can perform both write and read operation at low voltage and high speed, active research and development have been made for a ferroelectric memory (FeRAM) using a ferroelectric film having a spontaneous polarization characteristic as a capacitor insulating film.
Ferroelectric memory (FeRAM) stores information utilizing a hysteresis characteristic of the ferroelectric. In ferroelectric memory, ferroelectric capacitors having a ferroelectric film are provided for each memory cell as a capacitor dielectric film between a pair of electrodes. Polarization occurs according to applied voltage between electrodes in the ferroelectric material, and after the applied voltage is removed, a spontaneous polarization still remains. When the polarity of the applied voltage is reversed, the polarity of the spontaneous polarization also reverses. Accordingly, if spontaneous polarization is detected, information can be read out. Furthermore, when compared with flash memory, ferroelectric memory can operate under a low voltage, which makes it possible to write at high speed at a power-thrifty state.
The ferroelectric film used in FRAM is formed from a PZT series material such as lead zirconium titanate (PZT), La doped PZT (PLZT) or the like, a Bi-layer structured compound or the like such as SrBi2Ta2O9 (SBT, Y1), SrBi2(Ta, Nb)2O9 (SBTN, YZ) or the like.
Conventionally, a sol-gel method or a sputtering method has been used as a film formation method of a ferroelectric thin film. By these film formation methods, an amorphous phase ferroelectric film is formed above a bottom electrode film, and then, the ferroelectric film is crystallized into a Perovskite structured crystal by heat treatment. After the crystallization of the ferroelectric film, a top electrode film is formed. During this stage, the ferroelectric film is vulnerable to physical damage mainly by high energy sputtering particles at this time. As a result of such damage, a portion of the ferroelectric film crystal structure may be destroyed and the characteristics of the capacitor element are caused to deteriorate.
Therefore, in order to recover such deterioration of capacitor element characteristics, treatment like the following has been conventionally carried out. In a first conventional method, heat treatment is carried out in an oxygen atmosphere after patterning the top electrode film. In a second conventional method, heat treatment is carried out in an oxygen atmosphere after patterning the top electrode film and the ferroelectric film. In a third conventional method, heat treatment is carried out in an oxygen atmosphere after forming a capacitor element by patterning. In these treatments, oxygen recovers the crystallinity of the ferroelectric film.
Furthermore, in a conventional method, after formation of the capacitor element, an aluminum oxide film covering the capacitor element is formed as a diffusion preventing film to prevent the ferroelectric film from hydrogen deterioration. Consequently, in order to recover damage to the ferroelectric film sustained during patterning and during formation of the diffusion preventing film, heat treatment is again carried out in the oxygen atmosphere. Thereafter, an interlayer insulating film is formed.
Another method is disclosed in Patent Document 1 (Japanese Patent Application Laid-open No. Hei 5-251351). In the method disclosed in Patent Document 1, various types of heat treatment are carried out on the ferroelectric film in the oxygen atmosphere, aiming at obtaining a ferroelectric film having no oxygen holes, no generation of leakage current even by applying an electric field, and maintaining a dielectric constant. As the heat treatment, a method of irradiating ultraviolet rays to ozone or oxygen gas, heat treatment in an oxygen atmosphere under high pressure, and heat treatment using ozone gas can be cited.
Still another method is disclosed in Patent Document 2 (Japanese Patent Application Laid-open No. 2002-305289). In the method disclosed in Patent Document 2, by forming a PZT film which contains more Pb in compositional ratio than the PZT film as the capacitor insulating film after heat treatment to recover from damage to a ferroelectric capacitor, a side wall film is formed above a side surface of the ferroelectric capacitor. Due to such a side wall insulating film, the influence of hydrogen, H2O and the like existing in a TEOS film which is formed thereafter, is reduced so that deterioration of the PZT film characteristics is reduced.
However, even with the above-described methods, a ferroelectric capacitor having a sufficient characteristic cannot be obtained.
For instance, with the method disclosed in Patent Document 1, since crystal orientation of the obtained ferroelectric film is low, residual polarization is low.
With the method disclosed in Patent Document 2, when performing heat treatment to recover from damage to the ferroelectric capacitor, element having the highest vapor pressure moves out from an exposed portion of the ferroelectric film, and pin holes are formed in the ferroelectric film. In other words, when the PZT film is used, Pb loss comes out. Such Pb loss lowers a switching characteristic of the ferroelectric capacitor, and lowers an initial characteristic and retention. The occupation rate of the exposed portion where such loss occurs to the whole ferroelectric capacitor increases as the semiconductor integrated circuit becomes finer and finer. Accordingly, problems caused by such loss have been manifested recently. Furthermore, as the occupation rate increases, it becomes difficult to uniformly correct the Pb loss even when later forming a side wall film made from a PZT having plenty of Pb.
Moreover, with the method disclosed in Patent Document 2, due to the existence of the side wall film, a composition in the capacitor insulating film is easy to become uneven. Accordingly, the switching electric charge is apt to be lowered and imprint is apt to occur.
Patent Document 1
Japanese Patent Application Laid-open No. Hei 5-251351
Patent Document 2
Japanese Patent Application Laid-open No. 2002-305289

Method of manufacturing semiconductor device


A filtering system provides an oil flow to a filter carried by a support offset from a down tube of a motorcycle frame. An engine mounted bracket directs oil flow to be filtered to a cap assembly which is attached to an oil conduit. A threaded tubular member of the cap assembly permits rotational positioning of the attached conduit end, and positioning of the conduit, to facilitate conduit passage past motorcycle components to the filter support.

The present invention concerns the filtering of engine oil in motorcycle engines.
It is a common practice to locate a filter canister forwardly adjacent a motorcycle engine block between the block and rearward of the down tubes of the motorcycle flame. The clearance for such filter placement is minimal greatly complicating periodic replacement of the oil filter. As the filter is transversely disposed of the frame in a horizontal manner engine oil usually spills during a filter changing effort. In some motorcycles electrical components are located below the filter resulting in the components being contaminated. A further problem exists in that minimal clearance between the filter and motorcycle components prohibits or hinders the application of a filter wrench in most cases. Still further, the disposition of the oil filter forward of an engine cylinder reduces air flow therepast resulting in diminishing of the cooling effect.


A system on chip includes an interconnect circuit including at least p input interfaces and at least k output interfaces, p source devices respectively coupled to the p input interfaces and k access ports respectively coupled to the k output interfaces and belonging to a target that includes one or more target devices. Each source device is configured to deliver transactions to the target via one of the access ports. An associated memory of each access port is configured to temporarily store the transactions received by the access port. The target is configured to deliver, for each access port, a fill signal representative of a current fill level of its associated memory. A control circuit is configured to receive the fill signals from the access ports and select the access ports eligible to receive a transaction depending on the current fill levels.

A system on a chip or system on chip (SoC) is an integrated circuit that integrates all components of a computer or other electronic system. These components typically include a central processing unit (CPU), memory, input/output ports and secondary storage, which are all integrated on a single substrate.
Transactions are routed between source devices and access ports belonging to circuits such as a multiport memory. Sometimes the number of access ports is lower than that of the source devices.
The access ports generally comprise a memory (for example, stacks of 'first input first output' or FIFO type) that is intended to temporarily store the transactions received by the access ports.


A thermally balanced brake disc stack provides brake discs of greater mass at the center of the stack and of lesser mass at the opposite ends of the stack. The temperature of the high mass discs in the center of the stack will rise to a lower level than the thinner discs at the ends of the stack. However, the heat dissipation rate at the ends of the stack exceeds that at the center of such that all of the discs cool to a predetermined temperature concurrently.

It is well known that heat in vehicle braking systems is generally deleterious to the system, both structurally and functionally. It is further well known that aircraft often employ braking systems having brake disc stacks comprised of interleaved discs. The discs are alternately splined to the wheel and torque tube such that alternating rotor and stator discs are present within the stack. A stationary end plate is provided at one end of the stack, while an axially movable pressure plate is provided at the other. The application of force to the pressure plate urges the stator and rotor discs into frictional engagement with each other, providing the braking activity from the aircraft.
Presently known aircraft brake discs are made of steel, carbon, or appropriate composites. Irrespective of the type of material employed, tremendous heat is generated in the brake disc stack during a landing operation. While the brake discs typically begin to cool immediately following landing, the braking operations incident to taxiing generate heat in the stack, retarding the effective cooling thereof. While modern materials such as carbon and other composites are provided to withstand the high braking temperatures encountered, safety considerations preclude use of the aircraft following braking operations for a sufficient period of time to allow the brake discs to cool below a set temperature.
In the aircraft industry, each aircraft has a characteristic turnaround or ground waiting time. This is the time required for the hottest brake disc in the brake disc stack to cool below a specific temperature. For example, several aircraft manufacturers require the temperature of the hottest brake disc to be below the ignition point of the hydraulic brake fluid prior to take-off. The turnaround time characteristic is a function of the aircraft landing speed, mass, brake system characteristics, taxiing procedures, and the like. The turnaround time is, of course, substantially inactive ground time. As such, it is costly in the operation of aircraft, for aircraft generate revenues in the air, not on the ground.
To maximize braking efficiency, it is most desirable to minimize turnaround time and to maximize the brake cooling rate. In other words, it is most desirable to minimize the temperatures that the brake discs reach, while maximizing the rate of heat dissipation within the stack.
In the past, brake disc stacks have been formed with discs of generally uniform thickness. Extensively instrumented tests have shown that discs in the center of the stack cool the slowest, and thereby establish the turnaround time of the associated aircraft. While brake disc material may favorably impact heat dissipation rates, no previous consideration has been given to the thickness and positioning of the discs as a means of achieving such heat dissipation.


A refrigerator includes a thawing compartment in which food is to be thawed through the aid of a heater. An odor absorbing member mounted along a ceiling of the compartment comprises a porous plate which carries a platinum catalyst. The catalyst absorbs odors which are decomposed upon being heated to more than 100.degree. C. by the heater. Upon being heated greater than 250.degree. C. the odors form a platinum-sulfur compound which attaches to the porous plate.

A thawing compartment of some refrigerators that thaws frozen foodstuffs is located in the upper section of the cooling compartment, said thawing compartment being enclosed in a case which provides an interior space for storing foodstuffs and maintaining an atmosphere conducive to thawing foodstuffs.
Said thawing compartment has a cover at the front side to provide easy access for inserting or withdrawing foodstuffs and has an inlet in the rear surface to admit a portion of the cool air as it passes to the cooling compartment
An outlet is provided at the front of the ceiling of the thawing compartment to provide an air passage which directs the cool air to an evaporator after the cool air has passed in through the inlet and has contacted with the foodstuffs in the compartment.
Also, a heater is installed in the middle portion of the ceiling of the thawing compartment to facilitate quick-thawing.
Thus, the thawing compartment constructed as described above thaws foodstuffs either slowly or quickly.
For example, foodstuffs are thawed slowly when a portion of the cool air which flows to the cooling compartment is diverted into the thawing compartment, whereas foodstuffs are thawed quickly by the operation of the heater.
But, according to the prior art unpleasant odors are often emitted by foodstuffs such as fish, shellfish, or meat and the odors circulate throughout the interior of the refrigerator when foodstuffs are stored in the thawing compartment.
The unpleasant odors in the cooling and the freezing compartments as well as the thawing compartment impair the freshness of other foodstuffs stored in the refrigerator, and this gives the user an unfavorable feeling, and also creates an unsanitary condition.

Dedorizing device and method for the thawing compartment of a refrigerator


A roller machine and method for installing a flexible panel into a trench including a frame, a prime mover connected to the frame, and a plurality of rollers positioned on the frame. The plurality of rollers defining a curved path of travel for the panel. The path of travel has an entry and an exit. The path of travel is nearly vertical adjacent to the exit above and adjacent to the trench. The prime mover is drivingly connected to at least one of the plurality of rollers. The plurality of rollers includes a plurality of support rollers extending across the frame and having an adjustable length generally corresponding to a width dimension of the panel and a plurality of guide rollers arranged in aligned pairs. The guide rollers are positioned adjacent opposite ends of the support rollers and are arranged adjacent to the exit of the path of travel. The path of travel extends between each of the aligned pairs of guide rollers. The frame is supported by a plurality of wheels so as to allow the frame to be moved adjacent to and along the length of the trench. The guide rollers are configured to accept and conform to the edge of the panel or to the interlocking connector attached to the panel. The exit position of the guide rollers is adjustable so as to enable the interlocking connector to engage a mating connector on a prior installed panel.

Curtain walls (or cut-off walls as they are sometimes called) are extensively used as a means of separating or confining sources or potential sources of liquids or gases to prevent migration or mixing with the remainder of the environment. In their simplest form, curtain walls consist of a generally vertical barrier or restriction to lateral fluid flow. The barrier may be placed in a trench or otherwise installed across the potential route of fluid migration. The trench is most desirably of sufficient depth to reach and be sealed to a relatively impermeable strata at the lower extremity, thus providing a seal against egress of the media to be confined. This confinement is carried out so as to prevent or significantly reduce the spread of contaminants that might pollute the adjoining environment.
Various media have been used to form this barrier. This media includes materials such as clay and bentonite. More recently, synthetic membranes, such as high density polyethylene, have been used for this purpose. The membrane may be used independently or in conjunction with other barrier materials. The choice of high density polyethylene is based on its unique composition of properties of high mechanical strength, deformability, corrosion resistance, resistance to biological attack, impermeability to leachate and landfill gas, and extended service life. Other flexible membranes may also be used, if they are suitably resistant to degradation and/or permeation by the fluid t o be confined.
The high density polyethylene membranes, which are used in cut-off wall applications, are usually of a thickness of approximately 1.0 to 2.0 mm to provide sufficient mechanical strength to absorb forces encountered both in installation and in operation, to contain resulting strains within acceptable limits. Membranes of other thicknesses may be used to provide a service life consistent with the specific design purpose. Protection for the membrane such as a geotextile or selected backfill material may also be utilized in conjunction with the membrane. Where bentonite is used in the exacavation of the trench, this material also provides protection for the membrane as well as an additional sealant against fluid flow.
In certain circumstances, such as short, straight, and shallow cut-off trenches, it may be possible to easily install the membrane as a single section. However, in some cases, depth or instability of the subgrade may limit the amount of trench which can be open and maintained unobstructed at any time and in consequence require that the membrane be installed in a series of panels which must be jointed together within the trench. Other than in cases of broad open trenches where there is safe access for seaming, some form of mechanical interlock must be introduced to allow membrane panels of the appropriate width and depth to be installed consecutively with a joint which resists permeation to a degree consistent with the design objectives of the project.
The panel size may be limited by the length of an unsupported trench which can remain open for the installation. The degree of curvature of the trench and the angle of repose of backfill material must also be considered. Relatively short panels can easily be lifted vertically with a crane or hoisted and dropped or inserted into position. A framework of rigid materials may be employed to assist with the positioning of the membrane panel. The framework also serves to help resist the effects of wind as the panel is lifted. In some instances, the panel may be too long and/or wide to install with a vertical lift. In many instances, wind and/or limited head room or other obstructions may interfere with the vertical lift.
FIGS. 1A and 1B serve to illustrate the prior art technique for the installation of such flexible panels. As can be seen in FIGS. 1A and 1B, the usual approach is to suspend the panel 10, with suitable stiffening of the upper edge, above the trench 12 using a crane 14 or similar lifting equipment. The lock 16 along a vertical edge of the suspended panel 10 is entered into the lock 18 of the panel 20 already in place. The suspended panel 10 is then lowered into the trench 12. The leading edge of the in place panel 20 may be braced so as to hold it firmly in place during the fitting of the subsequent panel 10. Weights, stiffeners and/or cable arrangements may be attached to the panels so as to provide downward forces during installation. These items may also be used to assist with forming a seal or anchoring the panel in the desired position.
In FIGS. 1A, it can be seen that the suspended panel 10 is generally entered centrally into the trench 12. As can be seen, the trench 12 has a relatively narrow opening in comparison with the depth of the trench. The panels are continually installed, as shown in FIGS. 1B, until the entire length of the trench is filled with the panels.
One of the great difficulties with the installation technique, shown in FIGS. 1A and 1B, is the fact that a great deal of equipment is required for installation. When steel carrying frames are required to facilitate the installation of the panel 10, then additional expense and complication are involved. In situations where a frame must receive the panel 10, prior to installation, then the frame must be continually moved during the installation of each of the panels. Alignment must be achieved between the crane 14, any frames, and the panels 20 which are already in place. This is a highly complicated, slow, and expensive procedure. Wind can create great difficulties during this type of installation procedure. Additionally, overhead obstructions may restrict the amount of vertical lift that can be attained. In some situations, these overhead obstructions may have to be dismantled and reinstalled. Since precise alignment is required for each of the panels, a great deal of human manipulation is required so as to properly align the panels during installation. The soil conditions and characteristics adjacent to the trench may prohibit the close proximity of heavy equipment to the open trench if the trench is to remain open.
It is an object of the present invention to provide an apparatus and method for the installation of flexible panels which is relatively simple and easy to operate.
It is a further object of the present invention to provide an apparatus and method for the installation of flexible panels which requires a minimal amount of equipment.
It is still a further object of the present invention to provide an apparatus and method for installing a flexible panel which avoids wind effects.
It is another object of the present invention to provide an apparatus and method which permits installation without interferences from most overhead obstructions.
It is an additional object of the present invention to reduce the load on the soil adjacent to the open trench.
It is still a further object of the present invention to provide an apparatus and method for installing a flexible panel which greatly speeds the installation procedure and improves the overall efficiency of installation.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.

Method and apparatus for installing a flexible panel into a trench