A method of fabricating a nonvolatile memory device is disclosed. First, a lower insulating layer and a sacrificial layer are formed in sequence on a substrate. Then, a sacrificial layer pattern is formed through removing some part of the sacrificial layer by an etching process to expose some part of the lower insulating layer. At the same time, spacers are formed on sidewalls of the sacrificial layer pattern. The spacers are formed of polymers resulting from the etching of the sacrificial layer. The exposed lower insulating layer is removed to form a lower insulating layer pattern. Next, the sacrificial layer pattern and the spacers are removed. Accordingly, linewidth of a tunnel window which defined by the insulating layer pattern becomes narrow.

1. Field of the Invention
The present invention relates to a method for fabricating a memory device and, more particularly, to a method fabricating a nonvolatile memory device such as electrically erasable programmable ROM (EEPROM).
2. Background of the Related Art
With the development of high-capacity memory devices, nonvolatile memory devices are being increasingly important. An example of the nonvolatile memory device is EEPROM.
In the EEPROM, a tunneling region is formed under a floating gate region. Here, the tunneling region has to be narrower than the floating gate region in order to ensure high coupling ratio. The tunneling region is defined as a tunnel window. The tunnel window is one of most important parts in a nonvolatile memory device. The memory device operates by movement of electrons through the tunnel window.
FIG. 1 illustrates, in a cross-sectional view, a structure comprising an oxide pattern 10 and a gate poly pattern 14 on a substrate 10. Here, "L1" indicates a tunnel window. FIG. 2 is a graph illustrating relation between the width of tunnel window and the coupling ratio in a nonvolatile memory device. The coupling ratio increases as the width of the tunnel window becomes narrower. Therefore, present technology now focuses on the development of the process for forming a narrow tunnel window.
FIGS. 3a and 3b illustrate, in cross-sectional views, the fabricating process of a nonvolatile memory device according to a conventional method.
Referring to FIG. 3a, an oxide layer 32 is formed on a substrate 30 and a photoresist pattern 34 is formed on the oxide layer 32. Referring to FIG. 3b, some part of the oxide layer 32 is removed by an etching process using the photoresist pattern 34 as a mask to form an oxide pattern 32a. The etching process is generally wet etching and, therefore, the oxide pattern 32a is etched isotropically. As a result, linewidth of the region etched in the oxide pattern 32a is broader than the linewidth defined by the photoresist pattern. Such broadened linewidth results in low coupling ratio, thereby causing deterioration of device characteristics.
In manufacturing a semiconductor device, a lot of methods for shrinking critical dimension of any structure have been proposed. Among them, U.S. Pat. No. 6,579,808, Cho et al., discloses a method for fabricating a semiconductor device capable of maintaining contact hole of fine size when the contact hole for bit line formation is defined. The disclosed method by the Cho et al. patent comprises forming an insulating layer and an ARC (anti-reflective coating) layer on a substrate; removing some part of the ARC layer through a first dry etching process using a photoresist pattern as a mask and, at the same time, attaching polymers resulting from the dry etching process to the remaining ARC layer to form a polymer sidewall; and removing some part of the insulating layer through a second dry etching process using the photoresist pattern and the polymer sidewall as a mask to form a contact hole.
As another example, U.S. Pat. No. 6,368,974, Tsai et al., proposes a method for shrinking equivalent critical dimension of mask by in situ polymer deposition and etching. In the method by Tsai et al. patent, a polymer layer is formed on a photoresist layer and etched by a plasma reactor with at least two independent power sources. Here, voltages of all power source are adjusted such that etching rate and depositing rate are equivalent on surface of the photoresist layer and etching rate is larger than depositing rate in bottom of any structure of the photoresist layer. Therefore, the sidewall of any structure is filled by a conformal polymer layer and, then, width of any structure is efficiently decreased. Accordingly, the critical dimension of any structure is significantly smaller than critical dimension of the mask.
As another example, U.S. Pat. No. 6,319,822, Chen et al., discloses a method for etching of sub-quarter micron openings in insulating layers for contacts and via. The method by Chen et al. patent uses a hardmask formed of carbon enriched titanium nitride. The carbon is released as the hardmask erodes during plasma etching and participates in the formation of a protective polymer coating along sidewalls of the opening etched in the insulating layer. The protective sidewall polymer inhibits lateral chemical etching.

Method for fabricating nonvolatile memory device


By using a disc type resonator, a sensor detects a substance having a mass and the mass with high sensitivity. Moreover, it is preferable to detect a change in vibrations of a substance attached or adsorbed to an area having a vibration amplitude equal to or larger than a constant value. This disc type resonator can be fabricated by the MEMS technique by using single-crystal or polycrystalline Si as a structural material. To improve the attachment efficiency of molecules and the like to be detected, irregularity or a groove is preferably provided on the surface of the disc type resonator.

1. Field of the Invention
The present invention relates to a detection sensor and a resonator preferably used to detect presence or absence of a substance having a mass and the mass of the substance.
2. Description of the Related Art
In accordance with the progress of the microfabrication technique such as the micromachine/MEMS (Micro Electro Mechanical Systems) technique, a mechanical resonator with a very small size has been obtainable. Thereby, the mass of the resonator itself can be decreased, and a high-sensitivity resonator is being realized in which frequency or impedance characteristics are fluctuated by a mass change due to attachment of a very small substance (such as molecule or virus) at a molecule level. Use of this high-sensitivity resonator makes it possible to constitute a sensor capable of detecting presence and quantity of a very small substance. That is, because the size of the resonator is greatly decreased, the frequency of the resonator is increased up to GHz level and moreover, Si can be used as the material of the resonator. Therefore, the study aiming at integration with a semiconductor circuit is being progressed.
Moreover, by using the way of generating vibration (vibration mode) having a small vibration energy loss due to air viscosity or the like, it is possible to cause the resonator to generate the vibration having a very high Q value (Quality Factor) even in air and accurate observation of the frequency fluctuation has been achievable.
As an apparatus for detecting the quantity of a substance based on the frequency change of a resonator, a QCM (Quartz Crystal Microbalance) sensor is known. This uses the property of a vibration frequency fluctuating (or lowering) depending on the mass of a substance when the substance attaches to a quartz resonator. The QCM sensor has a superior performance as a mass sensor for measuring a very small mass change. For example, the QCM sensor is frequently used as a thickness meter (vapor deposition monitor) (for example, refer to Non-patent Document 1: WHAT IS A QUARTZ CRYSTAL MICROBALANCE—QCM, Internet<URL: http://www.pharmaceutical-int.com/categories/qcm-technolo gy/what-is-a-quartz-crystal-microbalance-qcm.asp>).
Moreover, a technique has also been proposed which measures a mass change of a lipid bilayer formed on the surface of a quartz resonator by allowing molecules for providing a gustatory sense or olfactory sense to be adsorbed by the bilayer (for example, refer to Non-patent Document 2: Ikuo Okabatake, "To measure gustatory sense or olfactory sense by weight", Analysis, The Japan Society for Analytical Chemistry, 2003, No. 10, pp. 606-609).
By using this system, it has been already reported that a hydrogen-gas detection sensor to which platinum or palladium is applied as a hydrogen-molecule adsorption film or alcohol component detection using a PMMA polymer or food smell detection can be realized.
However, in the case of the sensor using a resonator whose vibration characteristic is changed due to attachment of above-described very-small mass, there is always a demand for sensors of more sensitive, more compact, and lower in cost.
Moreover, in the case of the technique described in Non-patent Document 2, a lipid bilayer having a high adsorption property of molecules has been used. However, this bilayer indispensably requires moisture and the use thereof in a dry atmosphere is subjected to restrictions. Moreover, there are problems that it is difficult to freely micro-fabricate quartz and integrate the quartz with silicon. Because of these reasons, further ingenuity is necessary to improve the sensitivity.
In the case of a QCM sensor, a vibration frequency is shown by the following expression.fo=α/t
In the expression, α denotes a constant for determining a frequency and t denotes the thickness of a quartz resonator.
Thus, because the vibration frequency of the QCM sensor is inversely proportional with the quartz resonator thickness, it is impossible to sufficiently decrease the thickness. This means that increase of the ratio between a very small mass to be detected and the effective mass of a resonator is limited in the QCM sensor.
Moreover, when constituting a sensor for detecting the mass of a substance and when other substance other than a substance of interest attaches to a resonator, detection accuracy is deteriorated. Therefore, there is a demand for sensor capable of performing high-accuracy detection independently of an environment in which the sensor is used.
The present invention is made in light of the above technical problems and its object is to provide a detection sensor with high sensitivity, small size, low price, and high accuracy.

National Institute of Advanced Industrial Science and Technology


A method for sensor-based ejection of an aircraft occupant from an aircraft may comprise: receiving, via a processor and through a sensor, an ejection command from the aircraft occupant; comparing, via the processor, the ejection command to a predetermined ejection command; determine, via the processor, whether the ejection command matches the predetermined ejection command; and commanding, via the processor, initiation of an ejection event in response to the ejection command matching the predetermined ejection command.

Ejection systems are designed to expel pilots from an aircraft cockpit. Ejection seats in high performance aircraft benefit from safely removing the pilot or other occupant from the disabled aircraft across a wide variety of aircraft speed regimes, altitudes and aircraft attitudes. Ejections may be difficult to perform manually in various ejection situations.


A light energy powered charging system for recharging portable units such as battery powered hand tools and cellular telephones. The charging system includes a solar collection assembly having at least one light energy receiving panel. The collection assembly is mountable to a carrying vehicle. A multi-position connector is coupled to the receiving panel for facilitating the positioning of the panel toward a light source such as the sun or vehicle headlights. A power receiver is electrically connected to the receiving panel for accepting electricity generated at the solar collection assembly. The power receiver has a docking station for releasably receiving a battery powered portable unit such as a powered hand tool or a cellular telephone requiring recharging. The invention further includes a carrying motor vehicle. The solar collection assembly is coupled to the carrying motor vehicle by the multi-position connector. The carrying motor vehicle is a pick-up truck having a tool box located in a bed of the truck and the solar collection assembly is coupled to the tool box by the multi-position connector. The power receiver is positioned within the tool box located in a bed of the truck.

As our society becomes more mobile and simultaneously dependent upon electronic devices, it has been a natural progression for portable electronics to proliferate. This has given rise to a need for portable power sources that can be carried with these electronic devices during their portable use. Still further, because presently commercialized batteries are normally limited in capacity with respect to reasonable and expected use of such devices, industries have turned to rechargeable "battery packs" that may be charged between uses thereby obviating the need for frequent battery replacement.
One such area or industry which is enjoying a substantial increase in the incorporation of rechargeable battery packs is found in powered hand tools. A well known and common example is the battery powered rotary screw-driver having a rechargeable battery pack housed within the handle of the tool which may be "docked" in a charging stand. When the tool is not in use and is docked in the stand, the incorporated battery is being recharged for later use. Obviously, there must be a source of power for this recharger and therefore these rechargers are found at locations with power plug facilities. Because of the portable nature of these tools, it is not always convenient to return to such a stationary recharging unit. Instead, it has been recognized as a particularly beneficial aspect to have the capability to recharge such tools while they are being carried on a vehicle, but not in actual use.
The problem arises in that a ready power source is often not available on such a vehicle, and particularly when the vehicle is stationary with the engine stopped. In such a situation, the generator provided in the vehicle to power accessories and recharge the engine's battery is not operating unless the engine is running. Therefore, limited capabilities for recharging such portable tools places constraints on their use in truly remote locations or over extended periods of time when away from a stationary charging unit.
With the proliferation of communication devices such as cellular telephones and pagers that are battery powered, the necessity for recharging units has become even more important. Both types of these communication devices are often used in automobiles and for extended periods of time away from typical locations where stationary recharging units would be maintained. As an example, a cellular telephone user will often be away from their office for the entirety of a day and reliant upon pre-charged battery packs for powering the telephones. As a result, the need for portable recharging facilities is becoming ever more important and is expected to increase even more so with the increase in portable personal computers that are also often used at remote locations on battery pack power.
As a result of these needs for recharging capabilities at remote locations and on transporting vehicles, the present invention has been developed and designed to remedy the identified deficiencies and satisfy the consumer's needs.

Solar powered charger for vehicular accessories and cordless tools


An electrical plug-and-socket connector for conductive foils is designed so that it continues to operate reliably long-term under rough operating conditions. For this purpose, the plug-and-socket connector has a plug that can be assembled from a top part and a bottom part with the conductive foil glued into the plug and therefore sealed between these parts when the top part and the bottom part are joined. Furthermore, a sealing element is mounted peripherally on the plug, which is in close elastic contact with a peripheral sealing surface of the socket when the plug is inserted in a socket, and seals the joint between plug and socket. The electrical plug-and-socket connector for conductive foils is intended particularly for use in automobiles.

A plug-and-socket connection is described in European Patent Application No. 214,830 A2. This plug-and-socket connector has a socket with a box-shaped socket housing, which is enclosed on all sides up to an inlet opening to an insertion area for a plug. The plug is formed from a plate-type support element for the conductive foil that is in close contact with the support element on the outside; the support element is bent in a wedge shape and can be elastically pressed together.
When the support element is pressed together, it can be inserted in the insertion area of the socket housing, in which case contact elements of the socket make electrical contact with strip-shaped terminals of the conductive foil.
Such an enclosed plug-and-socket connector secured on the support element and on the socket housing in its end position via locking elements has, however, gaps due to the tolerance between inlet opening and support element through which media such as moisture and dust can penetrate in the socket insertion area and there can corrode the terminal contact elements.
Such a plug-and-socket connector is subject to failure, especially under rough operating conditions and is not reliable in the long run.

Electrical plug-and-socket connector for conductive foils


The invention relates to radiation sensitive compositions having high uniformity when deposited as thick films. The compositions of the invention comprise a radiation sensitive component and a resin binder blend. The resin binder blend is a mixture of an aliphatic novolak resin component and an aromatic novolak resin component.

1. Introduction
This invention relates to radiation sensitive compositions comprising a radiation sensitive component and a resin binder blend. In particular, the resin blend is a mixture of novolak resins which can provide highly uniform and thick coating layers.
2. Discussion of Related Art
Radiation sensitive compositions include photoresist compositions which are well known in the art and described in numerous publications including DeForest, Photoresist, Materials and Processes, McGraw-Hill Book Company, New York, 1975. Photoresists comprise coatings produced from solution or applied as a dry film which, when exposed to radiation of an activating wavelength, are chemically altered in their solubility to certain solvents. Photoresists can be negative-acting or positive-acting. Negative-acting resists are initially soluble in its developer, but following exposure to activating radiation, become insoluble in developer, thereby defining a latent image. Positive-acting resists work in the opposite fashion, radiation exposure making the resist soluble in developer.
Positive-working resists in general comprise a radiation sensitive compound and a film forming polymer blend. The radiation sensitive compounds, or sensitizers as they are often called, most frequently used are esters and amides formed from o-quinone diazide sulfonic and carboxylic acids. These esters and amides are well known in the art and are described in DeForest, suora, pp. 47-55, incorporated herein by reference.
The resin binders often used with the o-quinone diazides in commercial practice are the alkali soluble phenol formaldehyde resins known as the novolak resins. Photoresists using such polymers are reported in U.K. Patent No. 1,110,017, incorporated herein by reference. These materials are the product of reaction of a phenol with formaldehyde under conditions whereby a thermoplastic polymer is formed.
Positive photoresists using novolak resins as binders are often used as masks to protect substrates from chemical etching in photo engraving processes. For example, in a conventional process for the manufacture of printed circuit boards, a copper-clad substrate is coated with a layer of a positive-working photoresist, exposed to actinic radiation to form a latent circuit image in the photoresist coating, developed with a liquid developer to form a relief image and etched with a chemical etchant whereby unwanted copper is removed and copper protected by the photoresist mask is left behind in a circuit pattern. For the manufacture of printed circuit boards, the photoresist must possess chemical resistance, must adhere to the circuit board substrate, and for high density circuits, must be capable of fine-line image resolution.
Similar photoresists are also used in the fabrication of semiconductors. As in the manufacture of printed circuits, the photoresist is coated onto the surface of a semiconductor wafer and then imaged and developed. Following development, the wafer is typically etched with an etchant whereby the portions of the wafer bared by the development of the photoresist are dissolved while the portions of the wafer coated with the photoresist are protected, thereby defining a circuit pattern. For use in the manufacture of a semiconductor, the photoresist must possess resistance to chemical etchants, must adhere to the surface of the semiconductor wafer and must be capable of fine line image resolution.
For a number of processes, application of a thick photoresist film can be highly desirable. A coating film having a thickness of about 3.0 to 3.5 microns or greater is generally recognized and is referred to herein as a "thick" coating film. For an additive metallization process, a developed thick photoresist layer can be necessary. For example, it is often necessary to plate up a thickness of 5 microns or greater. To accomplish such plating, a developed photoresist image having well resolved sidewalls of a height equal to or greater than the thickness of plating is typically required.
Thick photoresist coatings also can be required to provide a uniform coating layer over topography. More specifically, in microelectronic applications, it is often necessary to apply a uniform coating layer over chip contact holes. To provide sufficient uniformity of the resist coating layer, application of a thick resist layer can be required.
Use of a metal plasma etch can also necessitate use of thick photoresist coatings. A metal plasma etch is typically quite aggressive to a photoresist film. By employing a thick resist film, a portion of the resist coating can be sacrificed during the plasma etch process without destroying the patterned image.
While the foregoing makes clear that photoresists that can be applied as thick films have significant utility, many known photoresists do not provide a highly uniform thick coating layer. Such lack of uniformity can be unacceptable for many applications.
It thus would be desirable to have a radiation sensitive composition that could be applied as a thick and uniform coating layer.

Radiation sensitive compositions comprising blends of an aliphatic novolak resin and an aromatic novolak resin


A control system for an internal combustion engine includes an exhaust gas purifying device, an exhaust gas temperature sensor, and temperature estimating device. The exhaust gas purifying device is provided to an exhaust duct of the internal combustion engine. The exhaust gas temperature sensor is provided in the exhaust duct on an upstream side of the exhaust gas purifying device. The temperature estimating device estimates a first exhaust gas temperature on a downstream side of the exhaust gas purifying device through a transfer function, which is expressed by a plurality of identical first-order lag elements, based on a second exhaust gas temperature on the upstream side of the exhaust gas purifying device sensed by the exhaust gas temperature sensor.

1. Field of the Invention
The present invention relates to a technology, which estimates an exhaust gas temperature of one of an upstream side and a downstream side of an exhaust gas purifying device based on an exhaust gas temperature of the other one of the upstream side and the downstream side, in a control system for an internal combustion, which includes the exhaust gas purifying device.
2. Description of Related Art
For example, in a diesel engine, there is provided a diesel particulate filter (DPF) as an exhaust gas purifying device for capturing particulate matters (PM) in exhaust gas. Because the captured PM is accumulated in the DPF, a DPF regeneration control is regularly performed in order to burn and remove the PM. When a temperature of the DPF rises too high in the DPF regeneration control, the DPF may disadvantageously deteriorate. Therefore, an exhaust gas temperature sensor is provided on an upstream side of the DPF, and in the DPF regeneration control, a combustion state in the DPF is adjusted based on the exhaust gas temperature on the upstream side of the DPF sensed by the exhaust gas temperature sensor.
An air-fuel ratio sensor, which senses an oxygen concentration (air-fuel ratio) in the exhaust gas, is provided on the downstream side of the DPF. The air-fuel ratio sensor includes, for example, a sensor element made of a solid electrolyte of zirconia, and the sensor element is kept at a predetermined activation temperature (e.g., 750° C.) such that a temperature detection signal, which corresponds to the oxygen concentration, is outputted. The sensor element internally has a heater, and when the heater generates heat by energization, the sensor element is heated such that the activation state can be maintained.
The oxygen concentration detected by the above air-fuel ratio sensor and a energization amount for energizing the heater of the air-fuel ratio sensor are influenced by exhaust gas heat of therearound to vary. Thus, an exhaust gas temperature sensor is provided on the downstream side of the DPF (e.g., near the air-fuel ratio sensor), and the influence by the exhaust gas heat is compensated based on the exhaust gas temperature on the downstream side of the DPF sensed by the exhaust gas temperature sensor. Also, when an engine is started in cold (i.e., when a cold start is made), moisture in the exhaust gas may be condensed such that condensed water may be generated. Then, when the condensed water is applied to the sensor element heated by the heater, the sensor element may be disadvantageously broken. Therefore, it is determined whether or not there is condensed water in an exhaust pipe (i.e., a wet-and-dry state is determined) based on the exhaust gas temperature on the downstream side of the DPF sensed by the exhaust gas temperature sensor. In accordance with the determination result, it is determined whether the heater is energized or not.
As described above, it is indispensable to know the exhaust gas temperature on the upstream side and the downstream side of the DPF in order to protect the DPF in the DPF regeneration control, and also in order to improve degree of detection accuracy of the air-fuel ratio sensor. In other words, exhaust gas temperature sensors need to be provided on the upstream side and the downstream side of the DPF, respectively, to sense corresponding exhaust gas temperatures. However, from a view point of cost reduction, the number of the exhaust gas temperature sensors needs to be reduced.
In order to solve the above disadvantages, there is disclosed a technology, where an exhaust gas temperature, which is sensed by an exhaust gas temperature sensor provided on one of the upstream side and the downstream side the DPF, is used to estimate an exhaust gas temperature of the other one of the upstream side and the downstream side. For example, in JP-A-2005-140069, a temperature change in the DPF is modeled by a transfer function, which is expressed by "first-order lag+dead time", and the temperature is estimated based on the model. In JP-A-2005-245109, similarly to JP-A-2005-140069, a transfer function, which is expressed by "n-th order lag+dead time" is used to model a temperature change in the DPF. However, each of these transfer functions is expressed by an approximate expression, which is experimentally computed, and therefore, a degree of estimation accuracy may not be disadvantageously sufficient.

Control system for internal combustion engine


A snap door including a door housing, a door body, a latch switch and a spring, in which one side of a lower plane of the door housing is open for placing a PCB mounted with plural control switches therein. The door body includes a lower case, an upper cover, a knob assembly and a front cover. The knob assembly has a knob holder, plural remote control knobs and plural resilient bridge portions extending between the knob holder and remote control knobs. The knob holder is attached to a lower plane of the upper cover. Respective remote control knobs are formed by extension members extending to the rear side from the resilient bridge portions of the knob assembly, control buttons projectingly installed to the front side of upper planes of the extension members, and switch operative projections protrudingly installed to lower planes of the extension members. Respective remote control knobs are arranged to allow the switch operative projections to be placed on the upper portions of the control switches on the PCB.

1. Field of the Invention
The present invention relates to a so-called snap door used for a household electric appliance such as a television, and more particularly, as illustrated in FIG. 1, to a snap door 14, which is mounted so as to be able to protrude forward and backward with respect to a cabinet 13 of a household electric appliance 11, such as a television, thereby exposing control knobs 12 at the front side of cabinet 13 or hiding control knob 12 inside the cabinet 13.
2. Description of the Prior Art
FIG. 2 shows a conventional snap door 14 of a household electric appliance functioning as stated above. The snap door 14 is formed by a door housing 21 and a door body 22 coupled to slidably move forward and backward with respect to the door housing 21. Also included as parts of the snap door 14 are a latch switch 23 for locking the door body 22 in the door housing 21, and a pair of compression springs 24a and 24b for pushing the door body 22 out of the front side of the door housing 21 when the latch switch 23 is released.
The door body 22 includes a lower case 26, an upper cover 27 coupled to lower case 26 by means of a pair of screws (not shown), and a knob assembly 28 provided to one side of the bottom plane of the upper cover 27. Additionally, a front cover 29 is joined to one side of the front of the lower case 26 and the upper cover 27.
The knob assembly 28 has a knob holder 30 and a plurality of control knobs 12. Also, a plurality of resilient bridge portions 32 extend between the knob holder 30 and the control knobs 12. The knob assembly 28 is attached to the lower plane of the upper cover 27 by means of the knob holder 30.
A sub-PCB 34 disposed with a plurality of control switches 33 is arranged in the lower case 26 below the knob assembly 28 in such a manner that the control switches 33 are positioned to underlie directly the respective control knobs 12. Thus, signals generated by control switches 33 are supplied via a connector wire 35 to a main PCB 36 positioned at the rear side of snap door 14.
The latch switch 23 is arranged at the rear side of an upper center plane of the door housing 21, and a hook 31 is projectingly installed on the lower case 26 of the door body 22 in a position corresponding to that of the latch switch 23 so that it will engage the latch switch 23 thereby locking the door body 22 inside the door housing.
Reference numerals 37a and 37b denote stoppers for preventing the forward deviation of the door body 22 from the door housing 21 induced by a biasing force of springs 24a and 24b. Reference 38 is a damper gear for preventing abrupt motion of the door body 22 when it is slidably moved with respect to the door housing 21. Reference 39 is a rack which is disposed on one side and at the rear of the lower case 26 of the door body 22, and meshes with a damper gear 38.
As shown in FIG. 3, the conventional snap door 14 is mounted in the cabinet 13 of a household electric appliance 11, such as the television, by means of a plurality of screws 25a and 25b. When a user of the household electric appliance 11 presses the closed front plane of the door body 22 as shown generally in FIG. 1, the latch switch 23 caught in a hook 31 is released to allow the door body 22 to open and protrude to the front side of the household electric appliance 11 as a result of the biasing force of the springs 24a and 24b.
Once the door body 22 opens, as shown in FIG. 2, the control knobs 12 are exposed to enable the user of the household electric appliance 11 to press a control knob 12 for manipulating the control switches 33, thereby making it possible to operate the household electric appliance 11.
The door body 22 is closed by the user pressing the front plane of the door body 22, thereby overcoming the biasing force of the springs 24a and 24b. The hook 31 catches the latch switch 23 to hold the door body closed, thereby concealing the control knobs 12.
However, in the conventional snap door 14 formed as above, and as shown in FIG. 3, the main PCB 36 is placed to the rear of the snap door 14. For this reason, the main PCB 36 is positioned at the rear of the cabinet 13 and recessed at least the length of the snap door 14. This causes a problem in that the household electric appliance 11 becomes bulky.
The conventional snap door 14 is constructed in such a manner that the main PCB 36 is separated from the snap door 14 as shown in FIGS. 2 and 3. This results in a drawback of additionally requiring the sub-PCB 34 for arranging the control switches 33 at the lower portion of control knobs 12 and the separate connector wire 35 for connecting the sub-PCB 34 to the main PCB 36.
Also, since the main PCB 36 is spaced apart from the front plane of the household electric appliance 11 by at least the length of the snap door 14, there is a need for a separate control PCB 34a for installing a power switch or remote-controller receiving portion and a separate connector wire 35a for connecting the control PCB 34a to the main PCB 36 in the vicinity of the front plane of the household electric appliance 11.
Furthermore, as shown in FIG. 3, since the main PCB 36 is separated from the front plane of the household electric appliance 11 by sufficient space to secure an operating distance for the snap door 14, there is the additional drawback of requiring a PCB holder 36a for fixing the main PCB 36.
Additionally, since the conventional snap door 14 has a door body 22, which is supported by a pair of springs 24a and 24b, it is difficult to provide a consistent and even spring force on both sides of the door body 22, with the consequence of incurring side-to-side shaking of the door body 22 with respect to door housing 21 when opening or closing the snap door 14.
Also, the conventional snap door 14 of the household electric appliance formed as described above has no means for preventing any upward and downward shaking of the door body 22 with respect to the door housing 21 when the door body 22 protrudes to the front of the door housing 21. Because of this fact, the door body 22 is shaken upward and downward against the door housing 21 whenever the user presses a control knob 12 of the door body 22.

Snap door for a household electric appliance


The present invention relates to a novel golf club having means to impart lift to the club head in order to counteract the forces which are exerted upon the head of the club during the swing that produce a dipping effect.

It has been observed through the analysis of stop-action photographs of the golf swing that during the down swing and principally just prior to contact between the club face and ball (hereinafter referred to as the "downswing"), the centrifugal forces that are generated by swinging the club are sufficient to cause the head of the wood to move off-center, relative to the ball, in the direction toward the plane of the shaft. Stated differently, as the club head approaches impact with the ball, its striking face should be generally square to the ball. A phenomenon called "dipping" alters this desired alignment by changing the vertical plane of the head and shaft so that the club head face (striking surface) and ball are not square at impact, the effect of which is to cause or contribute to an errant shot.
Dipping is believed to be the result of the centrifugal force caused by rotating the club head about a center of rotation. To better understand this concept and the effect produced thereby on the golf club during the portion of the swing from the top of the backswing through impact with the ball, consider that the center of gravity of a normal golf club head is off-set from the axis of the shaft and that during the downswing of the club, the center of gravity point of the head is urged to align itself with the axis of the shaft or the plane of the swing which is basically the same. In short, the head dips so that its center of gravity tends to align with the plane of the swing. As a result of these forces, the shaft bends out of its normal plane. FIG. 1 shows the golf club in an unaltered state at address. FIG. 2, shows the altered state achieved approximately at the ball contact point. As is shown in FIG. 2, the shaft is bending so that the center of gravity of the head is aligning with the plane of the swing. As can be seen, the head tilts at a slight angle which can substantially alter the flight of the ball and quality of the golf shot.
That the dipping phenomenon is not just a function of an individual's swing, has been confirmed by using a mechanical swing apparatus, known as the "Iron Byron" which reproducibly standardizes a golf swing and permits precise analysis of the structural effects on the head and shaft resulting from centrifugal forces throughout the swing. Measurements of the extent of the club head movement, measured vertically, and resulting from the centrifugal forces created during the swing have shown a change in the position of the head up to about one inch.
Applicants are not aware of any woods that are designed or include features that counteract the dipping effect. Golfers who are aware of dipping have sought to counteract the effect by positioning the club head above the ball at address, so that on impact with the ball the face of the club and the ball are substantially square. Of course, it requires considerable skill to make this adjustment to compensate for the dipping effect and the reproducibility factor, even for the good golfer, is far from satisfactory.
Applicants' invention contemplates a novel design modification of the head of a wood, which reduces or substantially eliminates the dipping effect by imparting "lift" to the head as it approaches impact with the ball.
While a review of the relevant prior art patents known to applicants reveals golf club head design features which tend to direct the flow of air in order to reduce air drag on the club and thereby to increase club head speed, none recognizes the dipping effect and none discloses or even suggests the objective of imparting "lift" to the club head. For example, U.S. Pat. No. 4,431,192 discloses the use of "vanes" attached to the head for directing the flow of air in a predetermined pattern to solve the problem of drag in a golf club driver. The patent further discloses that the vanes may be attached to the sole of the club and that they produce a "ram air exhaust effect".


A head-worn device system includes one or more cameras, one or more display devices and one or more processors. The system also includes a memory storing instructions that, when executed by the one or more processors, configure the system to generate a virtual object, generate a virtual object collider for the virtual object, determine a conic collider for the virtual object, provide the virtual object to a user, detect a landmark on the user's hand in the real-world, generate a landmark collider for the landmark, and determine a selection of the first virtual object by the user based on detecting a collision between the landmark collider with the conic collider and with the virtual object collider.

A head-worn device may be implemented with a transparent or semi-transparent display through which a user of the head-worn device can view the surrounding environment. Such devices enable a user to see through the transparent or semi-transparent display to view the surrounding environment, and to also see objects (e.g., virtual objects such as 3D renderings, images, video, text, and so forth) that are generated for display to appear as a part of, and/or overlaid upon, the surrounding environment. This is typically referred to as "augmented reality" or "AR." A head-worn device may additionally occlude a user's visual field and provide a virtual environment through which a user may move or be moved. This is typically referred to as "virtual reality" or "VR." Collectively, AR and VR as known as "XR" where "X" is understood to stand for either "augmented" or "virtual." As used herein, the term AR refers to either or both augmented reality and virtual reality as traditionally understood, unless the context indicates otherwise.
A user of the head-worn device may access and use a computer software application to perform various tasks or engage in an entertaining activity. To use the computer software application, the user interacts with a user interface provided by the head-worn device.


A channel decoding method includes constructing a maximum likelihood decoding problem including an objective function and a parity check constraint; converting the parity check constraint in the maximum likelihood decoding problem into a cascaded form, converting a discrete constraint into a continuous constraint, and adding a penalty term to the objective function to obtain a decoding optimization problem with the penalty term; obtaining ADMM iterations according to a specific form of the penalty term, and obtaining a channel decoder based on the ADMM with the penalty term; constructing a deep learning network according to the ADMM iterations, and converting a penalty coefficient and a coefficient contained in the penalty term into network parameters; training the deep learning network with training data offline and learning the network parameters; and loading the learned network parameters in the channel decoder based on the ADMM with the penalty term, and performing real-time channel decoding.

Channel decoding is used on the receiver side to return the binary information back to its original form based on the received signals. In a classical communication system, a message received by a sink is not necessarily the same as a message sent by a source, and the sink needs to know which source message is sent at this time, so a decoder needs to choose a source massage from a codebook based on the received massage. A linear programming (LP) decoder is based on the linear relaxation of an original maximum likelihood decoding problem, and is a popular decoding technique for binary linear codes. Because the linear programming decoder has a strong theoretical guarantee on the decoding performance, it has received extensive attention from academy and industry, especially about the decoding of low density parity check (LDPC) codes. However, compared with a classical belief propagation (BP) decoder, the LP decoder has higher computational complexity and lower error correction performance in a low signal-to-noise ratio (SNR) region.
In addition, since deep learning techniques have been successfully applied in many other fields, such as computer vision and natural language processing, it has also begun to be applied in the field of wireless communication, such as signal detection, channel estimation, channel coding, etc.
Unfolding an existing iterative algorithm is a more effective way to build a deep learning network recently. Different from some classical deep learning techniques such as the fully connected neural network and the convolutional neural network, which essentially operate as a black box, this method can make full use of the inherent mechanism of the problem itself and utilize multiple training data to improve the performance with lower training complexity.

Channel decoding method and channel decoding device


Time-interleaved signal converter systems are provided that multiplex respective digital sequences of system converters into an interleaved digital sequence before filtering each respective digital sequence with digital filters that apply respective filter coefficients to thereby reduce system degradation caused by converter timing skews. Use of the interleaved digital sequence in the filtering process substantially increases the system bandwidth from approximately one half of the converter sample rate RC to approximately one half of a greater system sample rate RS. Converter system embodiments are preferably configured to reduce large timing skews prior to filtering the interleaved digital sequence to obtain further reduction. This combined approach has been found to enhance interleaved system performance.

1. Field of the Invention
The present invention relates generally to time-interleaved signal converter systems.
2. Description of the Related Art
Analog-to-digital converters, each with a converter sample rate RC, have been arranged in time-interleaved converter systems to thereby obtain a greater system sample rate RS. Although time-interleaved converter systems can thus increase the speed of signal conversion, their successful realization must often resolve hardware limitations that degrade the accuracy of the system's digital output sequences.
A significant one of these limitations concerns timing skews in the samples of the analog input signal which each converter subsequently processes. These timing skews generally arise because of input signal path differences between a system input port and each converter's input sampler and/or signal path differences between the samplers and a clock generator that is clocking them.
Timing skews have been found to generate spurious tones that degrade a system's performance. The timing skews can be determined by various means such as storing known timing skews for subsequent use in the system and estimating the timing skews with various conventional algorithms. Some algorithms require the insertion of a calibration signal (e.g., a sinusoidal signal or a ramp signal) into the system input.

Time-interleaved signal converter systems with reduced timing skews


A coater for separating primary particles that are coated with a sticky or tacky resin, and covering the surface of the primary particles with a secondary particle of smaller size is disclosed. The coater includes a disc having a periphery, a motor engaging the disc so as to be able to spin the disc, and a restrictor mounted adjacent to the disc so as to provide a gap for the egress of coated particles near the periphery of the disc. Other embodiments of the invention will also have a first dispenser for particles disposed above the disc. Also conveniently, the coater will also have a second dispenser for particles disposed above the disc. In one application for which the coater can be employed, the first dispenser will be adapted to dispense a mixture of sand particles and polymeric resin, and the second dispenser will be adapted to dispense retroreflective glass beads.

In the manufacture of number of different commercial products, it is necessary to coat or encapsulate particulate matter. Such coatings may be applied, for example, to protect the particles from the environment, to provide timed release for the material of the particles, or to provide improved handling characteristics for the particles. A number of general techniques are practiced for providing a coating for particles and some of the known techniques involve a coating apparatus including a spinning disc onto which particles are dispensed.
However, one application for which existing apparatus and methods are not well-suited is the application of a coating that is sticky or viscous. The art is particularly at a loss when it is contemplated to encrust a primary particle within an even coating of smaller secondary particles using a sticky resin. Such encrusted particles would be of great utility in the field of retroreflective pavement markings.


Systems and methodologies are described that facilitate monitoring RF channels in a wireless communication environment to determine whether one or more channels comprise a forward-link-only (FLO) signal. A receiver can receive a first RF channel with a FLO signal and can monitor other RF channels for FLO signals. Upon a determination that a monitored RF channel comprises a FLO signal, the receiver can switch between the first RF channel and the monitored RF channel, employing information on current MLC decoding status, to facilitate providing seamless reception of the FLO signal, which can be superframe synchronized between RF channels. FLO signal detection can be performed using one or more of a wide-area identification channel energy detection protocol and a wide-area overhead information symbol decoding error detection protocol.

I. Field
The following description relates generally to wireless communications, and more particularly to monitoring and switching radio frequency channels in a wireless communication environment.
II. Background
Wireless communication systems have become a prevalent means by which a majority of people worldwide has come to communicate. Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. The increase in processing power in mobile devices such as cellular telephones has lead to an increase in demands on wireless network transmission systems. Such systems typically are not as easily updated as the cellular devices that communicate there over. As mobile device capabilities expand, it can be difficult to maintain an older wireless network system in a manner that facilitates fully exploiting new and improved wireless device capabilities.
A typical wireless communication network (e.g., employing frequency, time, and code division techniques) includes one or more base stations that provide a coverage area and one or more mobile (e.g., wireless) terminals that can transmit and receive data within the coverage area. A typical base station can simultaneously transmit multiple data streams for broadcast, multicast, and/or unicast services, wherein a data stream is a stream of data that can be of independent reception interest to a mobile terminal. A mobile terminal within the coverage area of that base station can be interested in receiving one, more than one or all the data streams carried by the composite stream. Likewise, a mobile terminal can transmit data to the base station or another mobile terminal. Such communication between base station and mobile terminal or between mobile terminals can be degraded due to channel variations and/or interference power variations.
Presently, a forward-link-only (FLO) signal can be transmitted to a user device over a radio frequency (RF) channel that occupies, for instance, a 6 MHz bandwidth portion in the lower 700 MHz frequency band. FLO signals can be present in more than one RF channel, for example, to accommodate multiple streams of contents. However, conventional wireless systems do not provide for monitoring and/or switching between a plurality of RF channels containing FLO signals, and the like. Thus, there exists a need in the art for a system and/or methodology of improving throughput in such wireless network systems.

Channel handoff methods in wireless broadcast systems


A two-way data network includes a broadcast control sub-network and a cellular data sub-network. The broadcast control sub-network includes a few high-power radio transmitters broadcasting into a large service area. The cellular data sub-network covers the large service area by a number of base stations each servicing a relatively small area. The wireless terminals of the two-way data network monitors the messages in a broadcast control channel at pre-assigned periodic time slots and remain in "sleep" mode at other times. A packet radio transceiver in the wireless terminal sends data to, and receives data from, the cellularized base stations. The broadcast control sub-network is used to notify the subscriber the receipt of a message. In responding to the notification, the location of the subscriber's wireless terminal is make known, thereby eliminating conventional tasks such as location and mobility management tasks and allowing wireless terminals to be low power. Communication between the cellular base stations and the wireless terminals achieves high data rate, low latency and high capacity.

1. Field of the Invention
This invention relates to a two-way wireless data network. More particularly, the invention relates to a two-way wireless data network, including personal mobile terminals, cellularized base stations distributed throughout a service area, and one or more network control stations.
2. Discussion of the Related Art
One-way communication systems, such as one-way paging systems, have become an increasingly important communication tool for business. Pagers are now indispensable for many people in conducting their business.
FIG. 1 shows a prior art one-way communication system 100 which is used as a one-way paging system. In a typical prior art one-way paging system, a paging party, i.e., the message sender, uses a telephone, e.g. telephone 101, to call the telephone number assigned to the paged party's pager 113. The call is received by a paging service station 103 over telephone line 102 (of course, telephone 101 could be a wireless telephone such as a cellular phone). At the prompting of paging service station 103, the paging party enters the number of his or her telephone 101. In some cases the paging party can also enter a short message at this time. Paging service station 103 converts the information received from telephone 101 into digital or analog data and transfers the data over line 105, or by wireless methods, to transmission tower 107. At transmission tower 107, a data signal 109 is generated and broadcast throughout the service area. The information that is typically included in data signal 109 is a unique identification code designating the receiving pager, and a very short message. The total size of the transmission packet is necessarily small, due to the low data rate (e.g. 2400 baud) and also because transmission tower 107 is a scarce resource shared by a large number of subscribers of the paging service over a large service area (e.g. 100 square miles). Transmission tower 107 necessarily uses high-transmission power to cover such a large service area. Further, because transmission tower 107 is shared by a large number of subscribers, not only must the messages be very short, the elapsed time between the time a message being provided to the paging network control center to the time it is transmitted can be a long delay.
When signal 109 is received by antenna 111, pager 113, which constantly monitors the broadcast channel to look for messages designated to it, alerts the paged party to the incoming signal 109 by beeping, vibrating, or some other alarm, and the telephone number of the paging party's telephone 101 (or the short message) is displayed on a display screen (not shown) of pager 113. The paged party must then respond. Responding to a paging message involves locating a second telephone 115, dialing the number displayed on pager 113, and contacting the paging party at telephone 101 over telephone line 117.
Because communication system 100 uses a single broadcast channel, and a very small number of transmitters is shared among a large number of subscribers, one-way paging network can be provided to a large number of subscribers at a user fee level which may be one-tenth the cost of cellular telephone communication. Communication protocols are also designed to allow the pager's radio receiver to "sleep" most of the time, except at pre-assigned time slots, without the risk of losing messages. Thus, a pager can typically operate on a small battery for a relatively long period of time (e.g. AAA battery operates a typical pager for a month; by comparison, a much larger battery provides several hours of use to a cellular telephone).
One-way communication networks such as the prior art one-way communication system 100 described above, are also used throughout the world for purposes other than paging. For instance, in some parts of the world, information dissemination systems, based on networks similar to one-way communication system 100, provide information such as prices of goods, stock prices, weather reports and news. Under this regime, the market, stock, weather, or news information is typically sent to service stations, similar to pager service station 103 in FIG. 1, where the information is encoded as analog or digital data. The data is then sent to broadcast station 107 where signal 109, which carries the data, is generated and broadcast. Signal 109 is then received by customers/subscribers on wireless terminals 113.
The information dissemination system based on prior art one-way communication system 100 described above is particularly useful for sending real-time information to rural or under-developed regions which are not adequately served by telephone lines and are too remote to receive standard radio or television broadcasts. Unfortunately, prior art one-way communication systems lack the ability to provide an immediate response or reply. For instance, as seen in one-way communication system 100, the paging party has no way of knowing whether the message, which is typically just the sender's phone number, was successfully transmitted or received by the paged party unless and until the paged party contacts the paging party. Further, the paged party typically cannot respond to the paging signal unless access to a hardwired or cellular telephone is available.
In addition, in a one-way communication system, the pager's lack of transmission capability severely limits its usefulness for information dissemination. For instance, because prior art one-way communication system 100 does not have an "information on demand" capability, information of potential interest to a subscriber in a broadcast region is transmitted indiscriminately to all subscribers in that region. The information is then typically repeated periodically or at regular intervals. Unfortunately, this scheme requires that each subscriber receive the same information. Typically, such indiscriminate broadcast of information results in more information than the subscriber actually wants and is inefficient. Further, because an individual subscriber does not have control over when the information is broadcast, for information having value related to its timeliness, e.g. a stock quote, the lack of "information on demand" is a severe drawback. Because of these limitations discussed above, and other limitations, one-way communication network 100 is thus limited to paging and information dissemination applications of the types discussed above.
To overcome the deficiencies of one-way paging services, two-way paging systems, are currently being developed. For example, the Motorola REFLEX system is designed to provide a reverse channel in the paging network so that pagers can acknowledge receipt of a message. FIG. 2 shows one such two-way paging system 200. Two-way paging system 200 includes: pagers 213 and 230, with antennas 211 and 231, respectively; transmission tower 207; and receiving stations 215-219.
Pager 213 includes a transmitter (not shown) so that when pager 213 receives signal 209 from transmission tower 207 (which, in this example, was initiated by a telephone call to a paging station, and leaving pager 230's identification code as the reply destination), the subscriber operating pager 213 respond to the message by transmitting a signal 220 to one of the receiving stations 215-219. It is worth noting that receiving stations 215-219 are listen-only stations and are not capable of transmitting messages back to a pager.
When one or more of receiving stations 215-219 receives signal 220 from pager 213, the receiving station or stations relay the data encoded in signal 220 to transmission tower 207 by line 222. Transmission tower 207 then broadcasts a signal 223 to the party operating pager 230.
By adding receiving stations 215-219, two-way paging system 200 solves one of the problems associated with one-way communication networks, i.e., subscriber operating pagers 213 or 230 can acknowledge receipt of a message immediately, without resorting to another communication medium such as the telephone. However, as pointed out above, data link 220 between pager 213 and receiving unit 215 is a one-way data link. Therefore, receiving station 215 cannot send any information back to pager 213. Consequently, a subscriber operating pager 213 still cannot determine whether his acknowledgement or reply signal 220 has been successfully received and forwarded by receiving station 215, until an acknowledgement message is sent via transmission tower 207. Because transmission tower 207 handles all broadcast traffic to the pagers, the acknowledgement message may be delayed for a long time. Consequently, two-way paging system 200 cannot be used for applications that require reliable data delivery confirmation. Further, because transmission of a data message depends on transmission tower 207, the bandwidth of transmission tower 207 is still limited in the same manner one-way communication network 100 discussed above. Thus, other than providing an acknowledgement capability to the pager, two-way paging system 200 suffers substantially all the disadvantages of one-way communication network 100.
In addition to the technical shortcomings of two-way paging system 200, two-way paging system 200 is also not economical. One major drawback of two-way paging system 200 is it's failure to make use of the existing one-way paging infrastructure. Instead, two-way paging system 200 operates in parallel with, and in competition with, existing one-way communication systems because two-way paging system 200 uses a different operating frequency from conventional one-way paging services which, in turn, requires separate transmission towers, signal protocols, data rates, and data formats which are incompatible with those used with one-way communication system 100. Consequently, in order for pagers 213 and 230 to communicate under two-way paging system 200, all subscribers operating wireless terminals must subscribe to the same paging service and nothing is offered to allow subscribers of two-way paging system 200 to communicate with other two-way or one-way paging services.
Since two-way paging system 200 does not utilize the existing one-way communication infrastructure, two-way paging systems, such as two-way paging system 200, have been slow to gain acceptance in the marketplace due to the large number of one-way paging systems already in use throughout the world which provide economical service and represent huge capital investments. The marginal additional capability of two-way paging system 200 does not justify the sizable additional investment necessary for such an entirely new and incompatible system. Besides, even if such an investment is made, building a new subscriber base for this system is likely to be difficult, since a minimum number or "critical mass" of customers is required before the network becomes viable. The new subscriber in prior art two-way paging system 200 faces not only the costs of both purchasing a new pager and accepting a new pager number, but also the severe constraint that two-way communications are possible only with other subscribers of the same paging service.
Two-way communication services which provides two-way communication between a cellularized receiving or base station and a mobile unit exist. For example, in a cellular digital packet data (CDPD) system, a large number of cellularized base stations are distributed all over the service area. Cellularizing the service area offers two advantages: (i) allow mobile units and base stations to transmit at higher data rate with relatively low power, since the expected distance between a mobile unit and a base station in the vicinity is short; and (ii) larger capacity is provided because base stations which are separated by large enough distances can use the same radio channels. Such a system provides thus very high capacity, low response delay and allows the mobile units to transmit at relatively high data rates. In such a system, two-way symmetrical and reliable data links can also be provided. However, such a system is expensive and complex.
In a CDPD system, because connectivity is maintained over the entire duration of a data communication session, multiple channels must be provided to allow multiple sessions to be maintained simultaneously. To locate a recipient mobile unit of a message, the network broadcasts the address of the recipient mobile unit from all the base stations in the service area until the recipient unit responds. Thus, a large amount of network resources is dedicated to locating mobile units. Further, to maintain continuous connectivity and to allow real time performance, when the session is established, the CDPD unit is associated with a base station with which it communicates. In addition, because a mobile unit can be expected to be used in a moving vehicle, it is possible that the mobile unit moves out of the service range of the initially associated base station and moves into the service range or ranges of one or more such base stations during the duration of a session. Thus, provisions must be made to disengage an associated base station and to engage an additional base station or stations ("hand off") during the course of the session. The control mechanisms for maintaining a CDPD session, including tasks typically termed "connectivity management" and "mobility management", involve sophisticated algorithms which require high performance computers to handle setting up the session, maintaining the session, and tracking the communicating mobile units as they move between service areas of the cellularized base stations. The complexity of the system requires a large investment in expensive equipment. Often, these control mechanisms are centralized, i.e. a large network switching or control center is provided to handle the mobile units in a given service area, so that, at times of heavy data traffic, the network control center may become a bottle neck, introducing undesirable latency into the system.
Another major disadvantage of the CDPD system is the requirement that the receiver of the mobile unit must be on at all times to receive messages. As a result, such a mobile unit requires a battery that is, at the present time, too undesirably bulky for mobile use. It would also be extremely difficult for power-saving features to be provided in such a mobile unit. Unlike a pager, which monitors only one paging channel, the mobile unit of a CDPD system must monitor a different radio channel when it is located in a different cell. Further, control information (e.g. timing information and recipient addresses) are broadcast by base stations in dedicated control channels. While a pager can be assigned a periodically occurring time-slot during which it "wakes" up to check for messages, a similar scheme in a mobile unit of a CDPD system would require timing in all the cellular base stations to be synchronized. Failure to synchronize all base station can lead to a mobile unit checking for the broadcast of its address during the wrong time slot.
Thus, what is needed is a method for establishing a two-way data network which (i) is high system capacity; (ii) has a low equipment cost resulting from a simple design, (iii) has a communication protocol which allows low-power operation by the wireless terminals; (iv) utilizes the existing one-way communication network infrastructure, (v) is compatible with existing one-way pagers; (vi) provides secure and reliable data transfer with short response time; and (vii) which allows bidirectional communication between mobile units without requiring sophisticated equipment to perform location, connectivity and mobility management tasks.

Two-way wireless data network having a transmitter having a range greater than portions of the service areas


It is an object to improve operation characteristics and reliability of a semiconductor device. A semiconductor device which includes an island-shaped semiconductor film having a channel-formation region, a first low-concentration impurity region, a second low-concentration impurity region, and a high-concentration impurity region including a silicide layer; a gate insulating film; a first gate electrode overlapping with the channel-formation region and the first low-concentration impurity region with the gate insulating film interposed therebetween; a second gate electrode overlapping with the channel-formation region with the gate insulating film and the first gate electrode interposed therebetween; and a sidewall formed on side surfaces of the first gate electrode and the second gate electrode. In the semiconductor device, a thickness of the gate insulating film is smaller in a region over the second low-concentration impurity region than in a region over the first low-concentration impurity region.

1. Field of the Invention
The present invention relates to semiconductor devices and a method of manufacturing the semiconductor devices.
2. Description of the Related Art
Recently, various types of circuits are often formed using thin film transistors (hereinafter, referred to as TFTs) over one substrate. In order to form various circuits using TFTs, attention should be given to that TFTs having different structures each of which corresponds to each of the circuits should be formed. This is because, considering the case of a display device, operating conditions of a TFT in a pixel portion and those of a TFT in a drive circuit are not always the same, and characteristics of TFTs which should also be different.
TFTs in a pixel portion which includes n-channel TFTs apply voltage to and drive liquid crystal as switching elements. The TFT in a pixel portion needs to have a sufficiently low OFF current value in order to hold charge accumulated in a liquid crystal layer during one frame period. On the other hand, since a buffer circuit and the like in a driver circuit are applied with a high drive voltage, it is necessary to increase a withstand voltage so that elements in the driver circuit are not broken even when the elements in the driver circuit are applied with high voltage. In addition, in order to enhance ON current drive capability, it is necessary to secure a sufficient ON current value.
As a structure of a TFT which reduces the OFF current value, a structure having a low-concentration impurity region (hereinafter also referred to as an LDD (lightly-doped drain) region) is given. Such a structure has a region to which an impurity element is added at a low concentration between a channel formation region and a source region or a drain region to which an impurity element is added at a high concentration.
Further, as a means for preventing degradation in ON current value due to hot carriers, there is a structure in which an LDD region is formed to overlap with a gate electrode with a gate insulating film interposed therebetween (such a structure is referred to as a gate overlapped LDD (GOLD) structure in this specification). With such a structure, a high electric field in the vicinity of a drain is relieved; therefore, degradation in ON current value due to hot carriers can be decreased. Note that in this specification, a region in an LDD region which does not overlap with the gate electrode with a gate insulating film interposed therebetween is referred to as an Loff region, while a region in the LDD region which overlaps with the gate electrode with the gate insulating film interposed therebetween is referred to as an Lov region.
Note that the Loff region have high effect on suppressing the OFF current value, whereas the Loff region has low effect on preventing degradation in the ON current value due to hot carriers by relieving the electric field in the vicinity of the drain. On the other hand, the Lov region works effectively in preventing degradation in ON current value by relieving the electric field in the vicinity of the drain; however, it does not work effectively in suppressing the OFF current value. Thus, it is necessary to form a TFT having a structure having characteristics in need for each of the various circuits.
Further, as to On current, there is also a method in which a contact resistance, which is parasitic resistance of a TFT, is decreased so that ON current is increased. In specific, nickel silicide is provided in a source region and a drain region to decrease contact resistance with a wiring (for example, see Patent Document 1: Japanese Published Patent Application No. 2006-156971).

Semiconductor device and method of manufacturing the same

Semiconductor Energy Laboratory Co., Ltd.


The present invention provides methods for integrating structural members inside the body of a propulsion vehicle with tankage used to store fluid propellant and the like. Propulsion vehicles may be made lighter, more compact, cheaper, and easier to manufacture by using pressurized membranes of the tankage to accomplish other structural purposes. More specifically, tanks may be integrated with thrust structures to transfer thrust loads from the engine to the main body of the vehicle. Alternatively, the tanks may be integrated with the vehicle engine. One tank may be integrated with one or more other tanks to form a single pressure vessel with multiple interior chambers. Methods of manufacturing a metallic integrated tank assembly include weld fabrication, machining, spinning, hydroforming, casting, forging, plating, metal deposition, or some combination thereof. Methods of manufacturing a composite integrated tank assembly include filament winding, fiber placement, hand-lay-up, or some combination. The methods listed above may be combined with other steps and tooling to create many different embodiments of the invention.

1. The Field of the Invention
The present invention relates to pressure vessels for carrying pressurized fluids. More specifically, the present invention relates to tanks designed to support an external, compressive load as well as the pressure of the fluid, for use in applications in which lightweight storage and structural members are desirable.
2. The Relevant Technology
Pressure vessels, or storage tanks, are commonly used to store fluids under pressure. Many types of propulsion vehicles require some type of fluid storage. For example, many types of launch vehicles, spacecraft, missiles, satellites, and rocket-propelled torpedoes all store a fluid propellant. Liquid fuel rocket motors typically require tanks of pressurized, combustible fluids that can be combusted and ejected from a nozzle to propel the rocket. Many forms of electric propulsion also require a pressurized fluid propellant. The term "fluid" includes both gases and liquids; many rockets store fuels in a substantially liquid form, with a component of combustible vapor. Additionally, rockets have a number of other structural features necessary for the rocket's operation. For example, rockets may have additional tanks, nozzles to direct exhaust gases, and thrust structures designed to convey force from the nozzle to the main body of the rocket. Typically, the inside of a rocket is a mass of tubes, tanks, wiring, and fixtures.
The cost and performance requirements that rockets typically operate under frequently dictate the use of lightweight, compact components. As a result, it is desirable to minimize mass and eliminate as much unnecessary structure as possible. Many vehicle applications are also volume sensitive and require that wasted space within the vehicle be minimized wherever possible. Tanks known in the art, however, are not well-suited to compact assembly, in part because they are often shaped with symmetrical, convex walls. Consequently, space between independent tanks and requisite inter-tank structure is typical. Furthermore, tanks known in the art create an enormous blockage through which it is difficult to route wiring, plumbing, conduits, and structural features necessary for operation of the rocket. The complexity of the rocket design is compounded because every other component of the rocket must be designed around the tank.
Furthermore, rockets often contain multiple tanks to hold different fluids, such as an oxidizer and a fuel. For example, oxygen may be stored in one tank, and a suitable liquid fuel in the other, so that the two may be combined to combust even in a vacuum. The use of multiple tanks adds additional complexity, volume, and weight to the rocket. A liquid-fueled rocket must typically carry two tanks, even though the fluids contained in the tanks are stored at similar pressures and will often be routed to the same location.
Consequently, there is a need, unfulfilled by the prior art, for part count reduction and for space and weight conserving tankage that can be effectively positioned within the body of a rocket or a similar propulsion vehicle, without hindering the placement of necessary equipment. There is a further need for space-saving configurations and structures that can be effectively used with tankage for the vehicle. The tankage and structures should be easily manufactured at low expense, and easy to assemble. Furthermore, the tankage and structures should be sturdy enough to tolerate the stresses created by high acceleration and vibration.
Similarly, there is a need for novel methods of manufacture, through which improved tankage and structures can be created, assembled, and installed in a propulsion vehicle. Such methods should be rapid, inexpensive, and preferably utilize available tooling with little modification.
The current invention discloses such an apparatus and method.

Integrated tankage for propulsion vehicles and the like


An image forming system has a plurality of image forming apparatuses that are operatively connected so as to communicate image information with each other. Some of the image forming apparatuses carry out image processing in a distributed manner with respect to image information that has been inputted to one of the image forming apparatuses and corresponds to a plurality of pages. Such some image forming apparatuses carry out the image processing for every predetermined pages of the image information in parallel and within processing capacity levels of such some image forming apparatuses. The processing capacity levels fall within a permissible range. Such an arrangement causes (1) to shorten the time required for processing to be carried out within the image forming system and (2) for the image-processed image information to be substantially the same level over the entire pages.

A digital copying machine, for example, has been commercialized as an image forming apparatus. According to the digital copying machine, when copying a document image, the document image is read by an image reading section. With respect to thus read document image, a specified image process is carried out by an image processing section. Then, image information in accordance with the specified image process is printed out by a recording section. Thus, according to such a digital copying machine, an image is copied onto a sheet of paper by using only the image processing functions that are provided in the digital copying machine.
In recent years, it has been proposed that a plurality of image recording apparatuses or other apparatuses be organized into a network. For example, unexamined Japanese Patent Publication No. 116834/1978 (Tokukaishou 53-116834) discloses an arrangement wherein a plurality of image reading apparatuses and a plurality of image recording apparatuses are connected through a control section. In such an arrangement, a document image that has been read by any of the image reading apparatuses is recorded, i.e., is printed by any of the image recording apparatuses.
Examined Japanese Patent Publication No. 36592/1995 (Tokukouhei 7-36592) discloses an image forming system wherein a plurality of copying machines, each having an image reading section and an image recording section, are connected to a control device. In such an image forming system, an image signal that is to be recorded is supplied to the copying machines in a distributed manner in accordance with a document copying mode that has been set, and copying operations are carried out by the copying machines in parallel with one another.
However, the conventional image forming systems have the following problems.
It is assumed that an image forming system has a plurality of digital copying machines. When carrying out the image process by use of a specified digital copying machine among the digital copying machines, the time required for the image process changes depending on the types of the image process or on the amount of image information to be image-processed.
Further, various image processing functions in the digital copying machine are dependent upon software. Here, with the recent remarkable developments of the software, the image processing functions have been highly improved in a very short period, and new copying machines having additional unprecedented functions have been newly introduced into the market. Consequently, for example, even when a digital copying machine having desired image processing functions is purchased, the digital copying machine, which has the highest image processing functions at the time of the purchase, will soon become outdated with relatively low functions in a short period.
In this case, it is impossible for the purchased digital copying machine to obtain functions higher than those originally provided in the digital copying machine. In the case where higher functions or newer functions are required, it is inevitable that a new copying machine has to be purchased to replace the older one. This tends to impose a big burden on users on an economic basis, and also to present an inherent problem for makers that try to provide consumers with new merchandise.

Image forming system having a plurality of image forming apparatuses for distributed printing


A micromechanical z-inertial sensor. The micromechical z-inertial sensor includes at least one first seismic mass element; and torsion spring elements joined to the first seismic mass element. In each case, first torsion spring elements are connected to a substrate, and second torsion spring elements are connected to the first seismic mass element. A first and a second torsion spring element in each case is joined to one another with the aid of a lever element. The lever element is designed to strike against a stop element.

A stop concept for micromechanical z-acceleration sensors is described in German Patent Application No. DE 10 2005 059 905 A1, in which stop knobs are provided on an underside of a movable structure, which strike against a stop surface, and thereby limit a movement in the z direction. A disadvantage is that several additional steps in terms of process technology are required for manufacturing such stop knobs.
Another disadvantage of the described stop concept is that a stop distance is set by the manufacturing process, which means that only stop knobs of a defined height are possible. Another disadvantage of stop knobs thus manufactured is that only a downward stop is possible. If an upward stop is also to be implemented, further added complexity in terms of process technology is required. A stop behavior of the z-acceleration sensor including the described stop knobs is defined by layer depositions or etchings, it being possible for relations between deposited layers to vary due to changing ratios, by which a stop behavior may be imprecisely defined in some circumstances.