A gas turbine vane having an inner shroud that is cooled by a portion of the cooling air directed to a cavity between two adjacent rows of discs. A portion of the cooling air in the cavity flows through impingement plates and impinges on the inner surface of the inner shroud. Another portion of the cooling air flows through a passage in the leading edge of the inner shroud that has a pin fin array for enhanced cooling. The impingement plates form chambers that collect both the impingement air and the pin fin passage air and direct it through holes in the trailing edge of the inner shroud for cooling of the trailing edge. Longitudinal passages along the side of the inner shroud direct the cooling air from the pin fin passage tot the trailing edge.

The present invention relates to a stationary vane for use in the turbine section of a gas turbine. More specifically, the present invention relates to the cooling of the inner shroud portion of a gas turbine vane.
A gas turbine employs a plurality of stationary vanes that are circumferentially arranged in rows in a turbine section. Each vane is comprised of an airfoil section formed between inner and outer shrouds. Since such vanes are exposed to the hot gas discharging from the combustion section, cooling of these vanes is of utmost importance. Typically, cooling is accomplished by flowing cooling air through radially oriented passages, such as forward and aft passages, formed inside the vane airfoil.
A portion of the cooling air flowing through the aft airfoil passage is typically discharged through cooling air holes in the trailing edge of the airfoil. Another portion of the cooling air flowing through the aft passage, as well as the cooling air flowing through the forward airfoil passage, is typically discharged from the vane through the inner shroud and enters a cavity located between adjacent rows of rotor discs. The cooling air in the cavity serves to cool the faces of the discs.
In the past, a portion of the cooling from the cavity between the discs has sometimes been used to cool the inner shroud by impinging cooling air against the shroud surface or flowing cooling air through passages in the body of the shroud. Unfortunately, traditional schemes have not made optimum use of this cooling air. Although such cooling air eventually enters the hot gas flowing through the turbine section, little useful work is obtained from the cooling air, since it was not subject to heat up in the combustion section. Thus, to achieve high efficiency, it is crucial that the cooling air be effectively utilized so as to minimize the amount of cooling air used.
It is therefore desirable to provide a scheme for efficiently cooling the inner shroud of a gas turbine vane.

Gas turbine vane with a cooled inner shroud


An apparatus for hitching two bicycles together including a first hitch which connects the apparatus to one of the bicycles and a second hitch which connects the apparatus to the second bicycle. The second hitch includes a stem which is slid through and secured to the head tube of the second bicycle after the front fork and wheel have been removed from the second bicycle.

The present invention relates generally to bicycles and, more particularly, to an apparatus for hitching a towed bicycle or the like vehicle to a towing bicycle.
A number of hitches and other devices are known for connecting two bicycles together or for creating a tandem bicycle. See, for example, U.S. Pat. Nos. 5,067,738; 5,470,088; 5,716,065; 5,785,335; and 5,938,223 which all disclose tandem bicycles where the rear or towed bicycle unit includes, among other elements, a hitch or frame which connects the towed bicycle unit to the seat post of the forward or towing bicycle.
A disadvantage associated with this type of hitching device however is that it requires the purchase of a combination hitch and rear bicycle unit which has no practical usefulness other than in connection with the creation of a tandem bicycle unit. Because the tandem bicycle units described in each of the above-identified patents are particularly suitable in applications where the rear bicycle unit is structured for use by a child, the usefulness of the rear bicycle unit ends when the child decides that he/she wants to ride his/her own bicycle without being towed. A new bicycle must then be purchased for the child.
This particular disadvantage has sought to be addressed by other hitches which allow an ordinary bicycle to be modified or used in a manner which allows the same to double as the rear bicycle unit of a tandem bicycle. See, for example, the tandem bicycle units and hitches disclosed in U.S. Pat. Nos. 4,458,908; 5,039,120; 5,372,371; and 5,860,662 which each require the removal of the front wheel of the rear bicycle unit before the bicycle can be used as the rear bicycle unit of a tandem bicycle.
One disadvantage associated with these hitch devices, however, is that they must incorporate special couplings and multiple intricate parts to allow the towed bicycle to tilt, articulate and bend independently of the towing bicycle.
The present invention is directed to a hitching and towing apparatus which uses an existing bicycle as the rear bicycle unit and incorporates a simple and inexpensive hitch which is slid through and connected to the head tube of the towed bicycle.
The present invention contemplates an apparatus for hitching a towed bicycle including a head tube to a towing bicycle. The apparatus includes a frame connected at one end to the towing bicycle and a hitch at the other end including a stem which is adapted to be slid through and secured to the head tube of the towed bicycle for connecting the apparatus to the towed bicycle.
In accordance with the present invention, the hitch also includes a hollow sleeve and the other end of the frame is adapted to be slid and secured in the sleeve of the hitch. The stem and the sleeve of the hitch are joined together at the ends thereof, as by a weld or the like, and the stem extends angularly upwardly away from the sleeve.
The stem also includes a collar which defines a stop which limits the distance which the stem extends through the head tube of the towed bicycle. Moreover, a threaded upper end on the stem is adapted to receive a threaded lock nut for securing the hitch to the head tube of the towed bicycle.
The apparatus further includes a pair of bearings on the stem of the hitch whereby, when said stem is slid through the head tube of the towed bicycle, one of the bearings is positioned between the collar and the lower end of the head tube of the towed bicycle and the other of the bearings is positioned between the lock nut and the upper end of the head tube of the towed bicycle. The bearings allow the stem to articulate and pivot about the head tube of the towed bicycle which, in turn, allows the towed bicycle to turn and articulate in response to the turning and articulation of the towing bicycle.
A second hitch associated with the one end of the frame connects the apparatus to the seat post of the towing bicycle.
Other features and advantages of the present invention will become readily apparent from the following detailed description, the appended drawings, and the accompanying claims.


Disclosed is a wet suit, including: an upper jacket 100 for, putted on an upper body of a user, injecting or discharging air into an interior by the user's operation or a predetermined operation; a pair of lower pants 200 putted on a lower body of the user; and a propulsive generation portion 300 for, detachably putted on a waist of the user, generating a self-propulsive force according to the user's operation or a predetermined operation to generates a propulsive force for pushing water to a rear direction of the user.

The present invention relates to a wet suit, and more particularly, to a wet suit which is capable of floating in water or automatically moving to a destination using self-propulsive force without using any rescue equipment.
Today, the population to enjoy marine leisure sports around surf clubs and scuba diving clubs is increasing rapidly. This tendency is reflected in the current trend of finding a room in the present life, unlike the past that devoted to the stable life of the future.
In many countries, which have the sea, rakes or rivers, marine leisure sports have been established only in the concept of leisure. Recently, the cruise law and marina act passed the national assembly plenary session, and the government is expected to nurture the marine leisure industry and expect the world marine industry to revitalize.
Water sports represents all kinds of water sports acting in rivers and seas, and includes traditional swimming, canoeing, kayaking, yachting and rubber boating, as well as windsurfing, kite boarding combined with surfing and paragliding, Kite surfing, water skiing, wakeboarding, jet skiing, fly fishing, and banana boats, etc.
These kinds of water sports are diversified every year, and people who enjoy these water sports are not only increasing in number, but also the places of water sports are diversified to rivers, seas and the sea, the importance of water leisure safety is also increasing, but it is still dependent on life jackets and wet suits.
For example, Korean Patent Publication No. 1995-0000511 (Jan. 3, 1995) discloses the buoyancy regulator for a wet suit to maintain neutral buoyancy at all times according to the depth of the submerged member. The feature of this publication is that a pressure regulating portion 60 is formed with an inlet 61 and a buoyancy adjusting graduation portion 62, 62′, 62″ and a weight display part 31 is formed on the support part 30, as the rubber film sheet 20 is sandwiched between the pressure forming portion 10 and the supporting portion, and the pressure regulating portion 60 is engaged with the spring 40 and the emergency button 50 so as to be in contact with the rubber film sheet 20.
In addition, Korean Patent Publication No. 10-1022974 (Mar. 9, 2011) discloses the flight suit for airline pilots with a life jacket and a manufacturing method thereof, which could not penetrate by liquids such as water into the interior, and has the characteristic of discharging out the water vapor from the body, excellent in fire resistance, comfort, warmth, waterproof performance, and are very easy to wear or peel.
In addition, Korean Patent Publication No. 10-1182957 (Sep. 7, 2012) discloses the life jacket combined of expansion tube and buoyant material, which absorb impact force or pushing force applied to the user's bust part, especially the heart, by a buoyant material of the life jacket, provide the warmth in cold weather, prevent flooding by primarily acting buoyancy when the user is dropped in the water, and folate the heart part of the recipient on the water surface to prevent drowning due to the high buoyancy of the air inflatable type air tube inherent in the life jacket.
Korean Patent Laid-Open Publication No. 10-2014-0120790 (Oct. 14, 2014) discloses the under wet suit, in which a warm pad is installed inside in which a cable for transmitting electric power is installed inside the under wet suit, so that it is possible to provide convenience in performing underwater activities by constituting along waist circumference. And the button portion configured with velcro can be selectively removed and attached by forming the attachment portion outside the wet suit, and each of the constitutions is configured by a heat generating device constituted by a structure capable of being combined and separated.
However, the main purpose of the conventional water sports wetsuit or life vest is to allow the user to float in the water for a predetermined time using buoyancy until the user is rescued from being dropped in the water. At this time, if the user needs to move before reaching Golden Time for survival (about 1 hour), the user must move to the desired destination by swimming or diving while wearing the wet suit. However, for those who are not good at water sports, or for the elderly, it will not be long enough to float in the water or to swim or dive over a distance, even if you wear a life jacket or wet suit.
The present invention has been made in order to solve the problems of the conventional art described above, it is an object of the present invention to provide a wet suit, which can continuously generate buoyancy by manually or automatically injecting additional air into an upper jacket and/or a pair of lower pants selectively, when the user wears the upper jacket and/or the pair of lower pants with constant buoyancy and an accident occurs in the water while enjoying water sports.
Another object of the present invention is to provide a wet suit which can be floated in water in a standing position for a certain time by generating a self-propulsive force in the event of an accident occurring in water during a user enjoying water sports.
Another object of the present invention is to provide a water suit which can move to the destination in a upright posture while raising the chest part on the water surface by generating a self-propulsive force when an accident occurs in the water during an enjoyment of water sports.
It is a further object of the present invention to provide a wet suit that can be implemented and provided with various types of wireless power generation devices therein.
A water suit comprises an upper jacket 100 worn on an upper body of a user, injecting or discharging air into an interior by the user's operation or a predetermined operation; a pair of lower pants 200 worn on a lower body of the user; and a propulsive generation portion 300 detachably worn on a waist of the user, generating a self-propulsive force according to the user's operation or a predetermined operation to generates a propulsive force for pushing water to a rear direction of the user.
According to the wet suit according to the present invention, the wet suit may continuously generate buoyancy by manually or automatically injecting additional air into an upper jacket and/or a pair of lower pants selectively, when the user wears the upper jacket and/or the pair of lower pants with constant buoyancy and an accident occurs in the water while enjoying water sports. Therefore, when enjoying water sports, it is not necessary to wear life jackets or wet suit that make movement unnatural, and the user may maximize the enjoyment of water sports by wearing only water suits easily according to the present invention.
In addition, the wet suit may be floated in water in a standing position for a certain time by generating a self-propulsive force in the event of an accident occurring in water during a user enjoying water sports. In case of being in the water, the heart part can be floated on the water surface for a certain period of time, thereby prolonging the user rescue time.
In addition, the water suit may be moved to the destination in a upright posture while raising the chest part on the water surface by generating a self-propulsive force when an accident occurs in the water during an enjoyment of water sports. Therefore, there is obtained an effect that it is easy to move to the desired destination within the golden time for survival, even if the user is a young person or an elderly person who is not good at swimming.
In addition, since various types of wireless power generation devices can be implemented, not only the water suit may generate the self-propulsive force for a long time, but also the reliability of the product can be increased.


A container comprising, a sidewall defining a cavity, and a liner secured to the sidewall and being movable in the cavity between different positions in the container.

The present invention relates to containers.
In the past, various containers or packages have been utilized for such purposes as storing or collecting articles. Sometimes separate packages or bags have been utilized with such containers for the articles However, the containers have not been sufficiently receptive for numerous uses, and must be specially tailored for each condition. Such containers may be open or closed.


An improved heat pump system of the type having a thermostat capable of generating at least three stages of demand signals, outdoor and indoor heat exchange coils, at least one fan, a compressor, an expansion device, with the flow of refrigerant being reversible for purposes of selecting between heating and cooling modes of operation and a supplemental heater having a plurality of supplemental heating units for further heating an air stream passing over the indoor coil through an air supply plenum to supply air to a comfort space. An improvement in this system where each of the supplemental heating units has a unique heating capacity; a combination of supplemental heating units can be selected that is responsive to a demand for heat from the thermostat; and the selected supplemental heating units are turned on appropriately so that the level of heat demand by the thermostat is provided.

1. Field of the Invention
This invention relates to climate control apparatus and more specifically to providing multiple stages of supplemental heating in a climate control apparatus having at least two units of supplemental heat that operates in conjunction with an intelligent thermostat.
2. Description of the Prior Art
Both heat pump systems and air conditioning systems which can also function to provide heat to a conditioned space, may be provided with supplemental heating elements. Specifically, with respect to a conventional heat pump system, during operation in the heating mode, the outdoor heat exchange coil acts as an evaporator withdrawing heat from the surrounding environment, while the indoor heat exchange coil acts as a condenser, giving up heat to the surrounding air. The heated air is in turn provided to the comfort space by being blown thereto through a plenum. Because of the relative temperatures and volumes of air and refrigerant involved, the temperature of the air normally sent to the comfort zone, the leaving air temperature, is normally relatively low. In fact it is often insufficient to provide the heat needed to prevent occupant discomfort.
Thus, when ambient temperatures approach the lower ranges, supplemental or auxiliary heat is generally provided in the form of electric heating elements, in order to augment the low level of heat provided by the pump itself. When these supplemental heating elements are present, the thermostat will normally be able to issue calls for heat on two levels--one for the primary heat available from the heat pump itself, and the other for supplemental heat, normally provided by electric heating elements. If all the electric heating elements are energized upon a call for supplemental heat, however, a number of problems can occur. First the temperature of the air discharged into the comfort zone will suddenly become extremely hot. While generally not hazardous, the sudden gust of heat can be unpleasant for someone who is positioned near a vent, and can create generally uneven heat in the comfort zone. The uneven heat is not only physically unpleasant but can also result in the thermostat functioning improperly due to erroneous temperature sensing. In addition, because electric is generally the most expensive form of heating, being considerably more expensive than that provided by a heat pump, use of the entire electric heating capacity every time supplemental heat is called for is not an energy efficient means of heating a comfort space.
In the prior art, staged heating has been provided in order to avoid using the full panoply of electric heating units every time there is a call for supplemental heat. Thus, in U.S. Pat. No. 5,332,028 to Derrick A. Marris assigned to a common assignee, a heat pump system was provided with a plurality of units capable of furnishing supplemental heat, so that the amount of supplemental heat produced could be staged. This is also the case in U.S. Pat. No. 5,454,511 which is incorporated herein by reference and which teaches a programmable or "intelligent" thermostat that has the ability to generate a continuously varying `demand` signal. Intelligent thermostats are also described in U.S. Pat. No. 5,270,952 to Adams, U.S. Pat. No. 4,522,336 to Culp, U.S. Pat. Nos. 4,836,442, 4,702,413 and 4,702,305 to Beckey and U.S. Pat. No. 4,606,401 to Levine. The teachings of the U.S. Pat. No. 5,332,028, 5,270,952, 4,522,336, 4,836,442, 4,702,413, 4,702,305, and 4,606,401 and the 8171 application are herein incorporated by reference as they apply to a heat pump with supplemental heating units and to intelligent thermostats.
However in the prior art heat pumps, even with staged electric heating, the staging could not be fine tuned. The number of stages possible was equal to the number of independent electrical heating elements, generally one, two or three Thus, in order to achieve three different stages of heating, three independent elements had to be used, which meant three connections and three sets of control links. It is both simpler and less expensive to achieve the same degree of discrimination with fewer elements, or a higher degree of discrimination with the same number of elements. Furthermore, the staging of electric heat, especially as provided by the instant invention, can reduce the peak demand for electricity that effects the delivery of this utility by the provider thereof. This not only conserves energy, but also helps prevent brown-outs that may otherwise occur when the weather is unusually cold in a normally temperate climate.

Multi-staging of supplemental heat in climate control apparatus


A method for using a single spare block pool in flash memory comprising: allocating a plurality of flash memory arrays, wherein each flash memory array comprises a plurality of flash memory blocks; within a main flash memory array: allocating a used block pool comprising a plurality of used blocks and allocating a main spare block pool comprising a plurality of spare blocks; within each of the other flash memory arrays: allocating a used block pool comprising multiple used blocks; allocating a minimum spare block pool comprising a minimum number of spare blocks; allocating the main spare block pool and each of the minimum spare block pools to a single spare block pool; transferring a spare block from the main spare block pool to one of the minimum spare block pools; and transferring a spare block from a first minimum spare block pool to a second minimum spare block pool.

Flash memory devices, which include arrays of Flash memory cells, are used in many applications for storing digital information. Flash memory is frequently used in portable electronic devices, digital cameras, personal computers, memory cards, and other types of devices. Due to the nature of these devices, the endurance, speed, and longevity of the Flash memory are important.
Flash memory devices may store data in arrays of Flash memory cells, including single-level and/or multi-level cells. A single level cell (SLC) flash memory stores one bit of information per cell, typically by programming and reading a binary charge (e.g., high or low charge). In contrast, multi-level cells (MLC) store multiple bits of information in each cell by programming and reading a level of charge in the cell. Multi-level cells may include cells that store two bits (MLCx2), three bits (MLCx3), N bits (MLCxN), etc. Flash memory cells are organized into blocks within the array, and the blocks may be arranged by block type into flash memory arrays, or populations of block types.
The majority of blocks in a Flash memory device are usable blocks, or good blocks. However, inevitably, every Flash device includes non-functional blocks, commonly referred to as bad blocks, which may be incapable of being erased or rewritten with new information for any number of reasons. Typically, a Flash memory device may include some bad blocks at the beginning of the life of the device, and the number of bad blocks typically increases during the lifetime of the device. Flash memory blocks can become bad from any number of reasons. For example, each block of flash memory is limited in the number of times the data therein can be programmed and erased, characterized by a maximum program/erase (P/E) cycle. Thus, if a block of the Flash memory has been programmed and erased a number of times exceeding the P/E cycle maximum, it may turn bad. Flash memory blocks may also become bad blocks by erase failure, or other causes.
In most instances, the capacity of a memory card or other device using Flash memory (referred to generally as a Flash device) must be guaranteed during a rated lifetime of the device. The Flash device capacity may be directly limited by the number of usable blocks available to store data. Therefore, in order to ensure that the card capacity is maintained throughout the rated lifetime of the Flash device, a system designer may allocate a certain amount of usable blocks in a spare pool to allow switching of good spare blocks instead of bad used blocks during usage. Maintaining a pool of spare blocks from which good blocks may be drawn upon in exchange for bad blocks allows a requisite number of usable blocks to be ensured throughout the life of the device.
In MLC flash memory devices, memory blocks may be used as different types, for example SLC, MLCx2, MLCx3 blocks, etc., each of which may have different reliability specifications. Due to the differing reliability specifications of each data block type, a designer may allocate different numbers of spare blocks associated with each block type.
FIG. 1 illustrates a Flash memory device with a known method of allocating and using spare blocks. A spare block pool of single level cells (an SLC spare block pool) exchanges blocks exclusively with an SLC used block pool. A spare block pool of multi-level cells (a MLC spare block pool) exchanges blocks exclusively with a main user mapped memory of used MLC blocks. Bad blocks are exchanged for spare blocks, and the flash memory device can no longer write information to the bad blocks. The pools are set at the start of the life of the flash memory device. Since the usage of each data type is unknown, the maximum spare blocks are typically allocated to each of the SLC spare block pool and the MLC spare block pool. The solution in this case is however sub-optimal because at the end of the lifetime of the memory device, some of the spare blocks from either the SLC spare block pool or MLC spare block pool will typically not be used.
However, the rate of deterioration may be different for the different block types, such that when a spare block pool of one type is depleted, the memory device may reach the end of its usable life, even though there may be spare blocks of other types remaining. For example, at a certain point in the life of the device, there may be too few usable SLC blocks to maintain the specified flash memory card capacity while a surplus of MLC block types remain. The lifetime of the device will therefore end while usable MLC spare blocks are still available. Consequently, all of the flash memory blocks will be sub-optimally exploited during the lifespan of the device.
A similar problem arises when handling caching and buffering for the flash memory write operation or when executing the static and dynamic wear leveling processes. Buffer and cache operations and static and dynamic wear leveling processes may both require use of spare blocks. A problem may arise when there are too few good blocks of one of the block populations, e.g., SLC, MLC, to allocate for buffering and caching, or for static and dynamic wear leveling.
For the foregoing reasons, there is a need for a flash memory method that ensures optimal usage of all blocks throughout the life of the flash memory device and increases longer flash memory device lifespan.

System and method for allocating and using spare blocks in a flash memory


A measuring device includes a transfer sleeve, an assist assembly, and a caliper gauge. The transfer sleeve includes two end surfaces and a side surface; the sleeve defines a transfer hole along the longitudinal direction thereof and perpendicular to the end surfaces, and the transfer hole passes through two end surfaces; the transfer sleeve defines a screw hole along the transversal direction thereof in the side surface and communicates with the transfer hole. The assist assembly is screwed in the screw hole, and includes a screw rod, a spring element, and a ball; the screw rod defines a receiving hole therein; the spring element and the ball are inserted into the receiving hole in sequence. The caliper gauge includes a base plate and two side plate extending upright from opposite edges of the base plate correspondingly.

1. Technical Field
The present disclosure relates to measuring devices and, particularly, to a measuring device that can measure if a tube is perpendicular to a base from which the tube extends.
2. Description of Related Art
Liquid crystal displays (LCDs) often include a base for supporting a main body (or other elements) of the LCD. To fix the main body to the base, a number of internally threaded tubes perpendicularly extend upwards from the base. As such, the main body can be fixed to the base by screws that match with the tubes. However, due to limited precision of manufacturing process of the base, it is not guaranteed that all tubes are precisely perpendicular to the base. As such, after the main body is assembled to the base, stress induced by those not precisely perpendicular tubes will be applied on the main body. This affects the quality of the LCDs.
Therefore, it is desirable to provide a measuring device which can measure the perpendicularity of a tube of a LCD to the base in order to prevent the above-mentioned limitations.

Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd.


A modular sorting station includes a frame defining an inbound bay and an outbound bay, each of the inbound and outbound bays being sized to receive an inventory holder containing inventory thereon. A robotic grasper is mounted to the frame and positioned above one of the inbound and outbound bays and operable to transfer inventory items from the inbound bay to the outbound bay, and a sensor mounted to one of the frame or robotic grasper and operable to identify inventory at the inbound bay when the inventory holder is present in the inbound bay. The frame is sized and arranged to align with a material handling grid and permit drive units to transport inventory holders into and out of the inbound bay and/or outbound bays while moving along the material handling grid; and the frame is portable such that the modular sorting station can be moved as a modular unit for rapid deployment.

Modern inventory systems, such as those in mail order warehouses, supply chain distribution centers, airport luggage systems, and custom-order manufacturing facilities, face significant challenges in responding to requests for inventory items. As inventory systems grow, the challenges of simultaneously completing a large number of packing, storing, sorting, retrieving, and other inventory-related tasks become non-trivial. In inventory systems tasked with responding to large numbers of diverse inventory requests, inefficient utilization of system resources, including space, equipment, and manpower, can result in lower throughput, unacceptably long response times, an ever-increasing backlog of unfinished tasks, and, in general, poor system performance. Additionally, expanding or reducing the size or capabilities of many inventory systems requires significant changes to existing infrastructure and equipment. As a result, the cost of incremental changes to capacity or functionality may be prohibitively expensive, limiting the ability of the system to accommodate fluctuations in system throughput.
Inventory systems can enhance throughput by efficiently using space and by employing automation, including robotic means to lift, transport, and place inventory. One heretofore significant drawback in such automation has been the difficulty that robotic inventory handlers have in locating objects co-located in containers. Furthermore, robotic inventory handlers can be expensive and time-consuming to implement, unlike a human workforce, which can be allocated according to need. For that reason, conventional inventory systems continue to utilize personnel for many inventory manipulation tasks, even though human intervention tends to increase costs and decrease speed throughout any automated system. For these reasons, increased flexibility and performance are desired in robotic inventory handling systems.

Modular automated inventory sorting and retrieving


A method of manufacturing a flash memory device according to an embodiment includes forming a second oxide layer pattern having a mask pattern buried therein on a first nitride layer pattern and a first oxide layer stack on a semiconductor substrate; forming first polysilicon patterns at sidewalls of the buried mask pattern; removing portions of the first oxide layer, the first nitride layer pattern, and the second oxide layer pattern to form a third oxide layer pattern, a second nitride layer pattern, and a fourth oxide layer pattern at lower portions of the first polysilicon patterns and the mask pattern; forming a fifth oxide layer pattern surrounding each of the first polysilicon patterns; forming second polysilicon patterns on sidewalls of the fifth oxide layer pattern; and removing the mask pattern and parts of the third oxide layer pattern and the second nitride layer pattern between the first polysilicon patterns.

The present disclosure relates to a method of manufacturing a flash memory device.
A flash memory device is a nonvolatile memory device that does not lose data stored therein even if power is turned off In addition, flash memory can record, read, and delete data at a relatively high speed.
Accordingly, flash memory devices are widely used for the Bios of a personal computer (PC), a set-top box, a printer, and a network server in order to store data. Recently, flash memory devices are extensively used for digital cameras and portable phones.
In such a flash memory device, a semiconductor device having a SONOS (Silicon-Oxide-Nitride-Oxide-Silicon) structure is mainly used.
Different from a flash memory device having a floating gate including polycrystalline silicon, the SONOS memory device is a charge-trap type device, in which gate voltage is applied to charges in order for the charges to pass through a thin oxide layer formed on silicon, so that the charges are injected into or released from a trap formed in a silicon nitride layer.

Method of manufacturing flash memory device


A fishing reel comprising a transmission line mounted within one of side cases for operatively interconnecting a handle and a spool shaft, a friction type drag mechanism mounted between a lateral outer face of the spool and a lateral side face of a mating element opposed to the lateral outer face of the spool to be rotatable in unison with the spool shaft, an engaging member having an engageable element for preventing reverse rotation and connected to the mating element through a connecting portion, and a stopper attached to a reel body and defining an engaged element engageable with the engageable element. The drag mechanism is switchable between an operative position and an inoperative position through relative movement between the spool and the mating element. The mating element and the stopper constitutes an anti-reverse mechanism. The mating element is supported by the other of the side cases, the drag mechanism includes friction surfaces surrounded by an enclosure continuously extending from the spool, the engaging member includes a boss portion having a diameter smaller than that of the engageable element, and the drag mechanism includes a seal disposed between the enclosure and the boss portion for closing a friction operative portion of the drag mechanism.

1. Field of the Invention
The present invention relates to a fishing reel, and more particularly to a fishing reel comprising side cases, a handle supported by one of the side cases for rotating a spool extending between the side cases in a direction for taking up a fishing line, the spool being slidable axially of and rotatable about a spool shaft, a transmission line mounted within one of the side cases for operatively interconnecting the handle and a spool shaft, a transmission line mounted within one of the side cases for operatively interconnecting the handle and the spool shaft, a friction type drag mechanism mounted between a lateral outer face of the spool and a lateral side face of a mating element opposed to the lateral outer face of the spool to be rotatable in unison with the spool shaft, the drag mechanism being switchable between an operative position and an inoperative position through relative movement between the spool and the mating element, and an anti-reverse mechanism including an engageable element connected to the mating element through a connecting portion, and a stopper attached to a reel body and defining an engaged element engageable with the engageable element for preventing reverse rotation.
2. Description of the Related Art
With the conventional reel as described above, one example of which is shown in Japanese Publication No. 50-9718, the mating element (as shown numeral 20 in the same Publication) is opposed to a left side face of the spool forming part of the anti-reverse mechanism. The friction type drag mechanism is mounted between the mating element and the left side face of the spool, and the mating element includes a flange portion horizontally extending from a lateral face of the mating element adjacent the side case. The flange portion defines internal teeth acting as an engaging element in an inner peripheral face thereof. Pawl means engageable with the internal teeth and acting as a stopper is attached to the side case of the reel body. The pawl means and the internal teeth constitute the anti-reverse mechanism.
An enclosure continuously extends from the left side face of the spool for enclosing friction faces of the drag mechanism. The enclosure defines inner peripheral edges that are close to outer peripheral edges of the flange portion.
In the friction type drag mechanism, if dust or seawater enters the friction faces, the drag performance is remarkably deteriorated. In view of this, it is desirable to mount a sealing element between the inner peripheral surface of the enclosure and the outer peripheral surface of the flange portion.
However, the sealing element has a mounting portion larger than the internal teeth acting as the engageable element, which increases the diameter of the sealing portion. As a result, when a contacting force is constant, a sliding resistance becomes large.
During a casting operation, when the drag force is canceled and the spool is rotated relative to the mating element, a large sliding resistance to rotation of the spool is created by the sealing element. This prevents the spool from rotating smoothly and the fishing line from feeding quickly.

310-go, City-Park-Kitanoda, 227-2 Takamatsu


A mower deck carriage for mounting a mower deck on a vehicle such as a mower or tractor, including laterally aligned, spaced channels attached to the upper side of the mower deck, a suspension frame attached to the vehicle, the suspension frame supporting a plurality of laterally aligned, spaced rollers, the rollers received in the channels. The mower deck channels are laterally moveable along the spaced rollers. A spring attached between the mower deck and the vehicle biases the mower deck in a preferred position. A mower deck guard extends exterior of the mower deck. The roller guard, the channels, the rollers and the spring allow lateral movement of the mower deck upon encountering a fixed object such as a tree or fence post.

Riding mowers are commonly used for mowing large lawns and grassy areas. Riding mowers often are constructed with a mower deck suspended below the mower body intermediate the front and rear wheels. Mower decks for installation on conventional tractors are often constructed to be suspended below the tractor body intermediate the front and rear wheels as on riding mowers.
Mower decks typically include a housing fixedly mounted to the tractor frame with means often provided to raise and lower the mower deck. One or more mower blades are suspended below the housing. Power transfer means are provided between the motor and the blade or blades. Such power transfer means often comprises a belt drive.
Riding mowers and tractor-mounted mowers are typically designed such that the mower blade and thus the housing extend laterally exterior of the wheels of the tractor or mower to provide a cutting swath at least as wide as the lateral width of the wider wheel set.
It is difficult to cut around objects such as trees and fence posts with riding mowers and tractor-mounted mowers due to the size, maneuverability and structure of the mower or tractor. Areas adjacent objects such as trees, fence posts and the like are often mowed with hand mowers or edgers, or left unmowed.
Mower decks for riding mowers and tractors are typically bolted to the underside of the tractor. To access the mower deck for blade sharpening, cleaning and greasing, it is generally necessary to detach the mower deck from the tractor, perform the sharpening, cleaning or greasing, and reinstall the mower deck by bolting it to the tractor, requiring that it be lifted to be reattached.
Parish U.S. Pat. No. 4,672,799 discloses a riding mower side guard adapted to move relative to the housing when the guard contacts a stationary object.
Hill U.S. Pat. No. 5,003,757 discloses a lawn mower discharge deflector horizontally and vertically pivotable in response to contact with objects.
McKeever U.S. Pat. No. 4,996,832 discloses a side guard for a lawn mower. Other patents relating to mowers or attachments include Lowry et al. U.S. Pat. No. 4,428,183, Ryken et al. U.S. Pat. No. 5,203,150 and Anderson et al. U.S. Pat. No. 4,677,814.
Presently practiced riding mowers and tractor mounted mowers do not provide adequate means for mowing areas immediately adjacent objects such as trees, fence posts and like stationary objects.
It is therefore an object of the present invention to provide a riding mower or tractor mounted mower providing means for effectively mowing areas adjacent trees, fence posts, and like objects.
It is a further object of the present invention to provide a mower deck for attachment to riding mowers and tractor mounted mowers, the mower deck laterally adjustable in relation to the mower or tractor.
It is a further object of the present invention to provide a mower deck which is laterally adjustable responsive to objects encountered during mowing.
It is a further object of the present invention to provide a mower deck which may be readily attached to and detached from the tractor.
The foregoing and other objects of the present invention are accomplished by a mower deck carriage for mounting a mower deck on a mower or tractor including laterally aligned, spaced channels attached to the upper side of the mower deck, the mower deck suspended from aligned, spaced rollers receivable in said channels, which rollers are attached to the tractor. The mower deck channels are laterally moveable along the spaced rollers. Springs are attached between the mower deck and the tractor to bias the mower deck in a preferred position. A mower deck guard extends exterior of the mower deck. Rollers are provided on the guard extending laterally therefrom to reduce friction at engagement of the guard with objects such as trees or fence posts. The roller guards, the channels, rollers and spring means cooperatively bias the mower deck in a preferred position and allow lateral movement of the mower deck upon encountering a fixed object such as a tree or fence post.


A scissors type mobile tool cart for supporting a tool box on a platform that can be raised or lowered to various heights. The tool cart has a safety locking mechanism which prevents collapse of the cart and which must be manually operated to change the height of the platform which is supporting the tool box.

This invention relates to a new and improved cart, and more particularly to a compact mobile cart with a platform supported on a pair of scissor systems vertically adjustable for positioning a load at different heights to eliminate stooping.
In maintenance and stock work, for example, it is often necessary to move tool boxes or supplies from one location to another location. In the past, carts used in moving maintenance tools or small stock have either been of the four wheel type having a fixed platform approximately waist high, or of the two wheel tiltable dolly type, having a platform near ground level. The four wheel type is difficult to move in confined spaces or over hoses or up stairs and requires much wasted movement to obtain tools or stock when working below the fixed height of the load carrying platform. The two wheel dolly type, although more maneuverable, requires constant stooping to obtain tools or stock.


A helical conical spring lock-washer includes a lock-washer body having formed on one surface thereof a plurality of triangular pyramid-shaped depressions. Each of the depressions provides a triangular opening formed on the respective surface of the lock-washer body, with the base of the triangular opening positioned adjacent to the outer margin of the lock-washer body and the apex of the triangular opening directed toward the center of the lock-washer body.

This invention relates to a helical conical spring lock-washer, and more particularly to a helical conical spring lock-washer which is designed to further improve the effect obtainable by the "Conical Spring Washer" which is the subject of U.S. Pat. No. 4,103,725, and also to further reduce the production cost of such washer, as well as to a method of formation of such lockwasher.
Hithertofore, as spring lock-washers, spring washers of rectangular cross section, conical spring washers and internal or external toothed lock-washers have been known.
The spring washer is produced by winding a flat steel wire into a continuous spiral and cutting the spiral by each turn of the spiral. The spring washer is the least expensive, with respect to material cost and production cost, of known washers for the prevention of loosening. However, the non-loosening effect obtainable by this type of washer is quite doubtful and some automobile makers have completely abandoned the use of such washer. The reason for such abandonment of use is due to the facts that unstable induced axial forces are developed by the rotation of the washer together with a fastening device such as a bolt or nut during the tightening of the fastening device, and that insufficient spring effects remain after the tightening of the fastening device.
In addition to the spring washer, there are conical spring washers and internal or external toothed lock-washers which are produced from a steel sheet or steel strip. Although these washers exhibit stable induced axial forces and an excellent non-loosening effect over the spring washer, the yield rate of these washers is 40-50%, and these washers thus have the disadvantage of considerably high production costs due to required pressing operations.

Helical conical spring lock-washer and method of formation thereof

c/o Abe Gijutsu Consultant, No. 119, 2-Chome, Mino-Cho


This invention discloses methods for the fabrication of organic semiconductor material-based devices under non-vacuum environment. In one embodiment, electrodes are formed by electrodeposition from an electrolyte containing ions or complexes of the electrode materials to be deposited. In another embodiment, electrodes are formed by solution processing from a solution (or ink) containing nano-particle of the electrode materials or the precursor of electrode materials to be deposited. In addition, two different modes, either layer by layer or layer to layer, are disclosed for the fabrication of organic semiconductor material-based devices, wherein all semiconductor organic materials required by the function of the desired device are deposited under an non-vacuum environment.

Organic materials with controlled structures may have electronic and opto-electronic properties similar to inorganic semiconductor materials and are suitable for the fabrication of electronic and opto-electronic devices [J. H. Burroughes, C. A. Jones, and R. H. Friend, "New Semiconductor Device Physics in Polymer Diodes and Transistors," Nature, 335, 137(1988)]. The organic semiconductor devices which have been investigated recently include but not limited to organic thin film transistor, organic photo-voltaic for solar electricity or photo-detector, organic solid state laser or organic solid state lighting, organic thin film memory for data storage, organic sensor for bio-application and chemical detection, and organic light emitting diode for flat panel applications.
Due to chemical nature, these electro-opto active organic semiconductor compounds are classified into two general categories: small molecules or macromolecules. Examples of small molecules include Alq3 [C. W. Tang and S. A. Van Slyke, "Organic Electroluminescent Diodes," Applied Physics Letter, 51, 913(1988)], Irppy [M. Pfeiffer, S. R. Forrest, K. Leo and M. E. Thompson, "Electrophosphorescent p-i-n Organic Light-Emitting Devices for Very High Efficiency Flat Panel Displays," Advanced Materials, 14(2), 1633(2002)], etc. which have been employed as light emitting materials or charge transporting materials in the fabrication of organic light emitting device (OLED), and the devices based on these small molecules are specifically referred to as SMOLEDs. Similarly, macromolecules such as poly(p-phenylene vinylene (PPV) [J. H. Burroughes, D. D. C. Bradley, A. R. Brown, R. N. Marks, K. Mackay, R. H. Friend, P. L. Burns, and A. B. Holmes, "Light-Emitting Diodes Based on Conjugated Polymers," Nature 347, 539 (1990)], polyfluorenes (PF) [A. Yasude, W. Knoll, A. Meisel, T. Miteva, D. Neher, H. G. Nothofer, and U. Scherf, "End-capped polyfluorenes, films and devices based thereon," EPI 149 827, 2001], polyvinylcarbazole (PVK), polythiophenes (PT), etc. have been also employed as light emitting materials or charge transporting materials in the fabrication of OLEDs. The devices based on these polymers are specifically referred as PLEDs. For SMOLEDs, the organic semiconductor materials are normally deposited by a vacuum deposition method, also called a dry-vacuum processing in general. For PLEDs, the organic semiconductor polymers are deposited by spin coating, ink jet printing or screen printing, also called a wet-solution processing in general. Of the two OLED technologies, the industry considers polymer-based one to be a more viable solution because of the potentially lower manufacturing costs and greater processing flexibility. The main advantage of polymeric materials is that they can be deposited by simple solution processing techniques such as spin coating, inkjet printing and other conventional printing methods, which require relatively inexpensive equipment than the dry-vacuum processing. If organic semiconductor devices and circuits can be fabricated using the simple solution processing techniques, then low cost electronic and opto-electronic units and systems will be available in the future.
However, such an advantage in the fabrication of polymer-based devices (PLED for example) comparing to that of small molecular-based devices (SMOLED for example) has not been realized yet in industry. This is mainly due to the difficulty in fabricating good quality electrodes. In order to make an organic semiconductor device, electrodes must be deposited onto the organic semiconductor materials. Currently, no matter if the organic semiconductor devices are prepared from small molecules or polymers, their contact electrodes are still practically deposited by vacuum methods such as vacuum thermal evaporation, vacuum sputtering, chemical vapour deposition and others.
The requirements for electrode fabrication using the vacuum methods make the fabrication of polymer-based organic semiconductor devices to be even more complicated. For instance in making PLEDs, after the organic semiconductor materials have been deposited by a wet-solution method, the sample has to be transferred to a dry-vacuum environment for the deposition of contact electrodes. An integration of a wet environment and a dry-vacuum environment required in the current fabrication method is expensive and complicated.
Furthermore, in order to facilitate the charge injection in an organic semiconductor device, a low work function metallic layer is often used as cathode. One example is in an organic light-emitting device (OLED), where a low work function metal electrode such as Ca, Mg, Li and alloys must be deposited in order to achieve efficient charge injection. During operation, the low work function materials will allow a large injection rate of electrons into the organic semiconductor to increase the charge injection efficiency. Due to the chemical reactivity, most of the low work function materials are very active when exposed to an environment containing oxygen and water. These materials can form oxides or hydrides rapidly even at room temperature. Therefore, the fabrication of organic devices involving the low work function materials is even more difficult to achieve without a high vacuum. As mentioned before, it is rather expensive to set-up and to maintain a high vacuum system for the deposition of the low work function electrodes. This is especially true for large-scale production of these organic semiconductor devices for circuit applications. From the above comments, it is clear that it is highly desirable to have an organic device where the electrodes, specifically the ones with low work functions, are fabricated using a method other than vacuum deposition.

Non-vacuum methods for the fabrication of organic semiconductor devices


A sonic or acoustic tool having a transmitter and a receiver and further having a receiver testing and calibration device is disclosed. Methods for testing and tuning acoustic receivers dynamically are also disclosed. The calibration device includes an acoustic signal generator in acoustic communication with a receiver or a plurality of receivers, where the generator generates an acoustic calibration signal or test signal which propagates to each receiver. The receiver response is monitored to determine receiver integrity and tune. Based on the response, the processing unit or units can adjust the receiver response or instruct tuning circuitry associated with the receiver to adjust the receiver response.

1. Field of the Invention
The present invention relates to sonic or acoustic tools including a calibration and/or testing device for tuning or calibrating acoustic receivers and associated electronics or testing the stability and integrity of acoustic receivers and associated electronics.
More particularly, the present invention relates to acoustic downhole tools including a transmitter, an isolator, a receiver, associated electronics and a calibration device for dynamic receiver calibration and receiver/electronic integrity and/or stability testing. The present invention also relates to methods of making and methods of using the tool.
2. Description of the Related Art
In general, the apparatus for making an acoustic log consists of a transmitter capable of providing acoustic impulses, and at least one receiver responsive to acoustic energy, both mounted on a support for movement through the length of a well bore. The transmitter and receiver are spaced apart by a fixed distance and as the support is moved through the well bore, the energy from the acoustic pulses periodically generated by the transmitter is picked up by the receiver after transmission through and reflection from the well bore. The amplitudes of the received signals are correlated with the depth in the well bore to provide a log indicating the qualities of the cement bonding to the bore over the length of the well.
The acoustic transmitter and receiver(s) employed for these purposes typically comprise a piezoelectric or magnetostrictive element which converts periodic electric impulses into acoustic waves corresponding to the frequency of the periodic electric impulses and having an amplitude generally proportional to the energy of the electric impulses. The receiver, on the other hand, receives acoustic waves impinging thereon converting the pressure waves into an electric signal generally proportional to the intensity of the acoustic wave energy or amplitude. Thus, the receiver and transmitters work essentially in the opposite format.
For effective operation of these components, it is necessary that they both be efficiently coupled to the surrounding media and at the same time carefully protected or insulated from deleterious effects of liquids and gases present in well bores or casing. As the tool move through the well bore, the tools will encounter numerous changes in heat and pressure and spurious acoustic and vibrational disturbances which can result in tool malfunctions or calibration drifts.
One major drawback to present acoustic or sonic tools is the lack of ability to calibrate or even test the receivers and associated electronics for integrity or stability during down hole operations. Numerous U.S. Patents disclose acoustic or sonic LWD tools including, for example, U.S. Pat. Nos. 3,213,415, 4,809,236, 5,197,038 and 5,485,431, but none address real time calibration and integrity testing of the receiver portion of the tool.
Therefore, there is a need in the art for improved sonic tools having receiver testing and calibration capabilities. Moreover, there is a need in the art for improved sonic tools allowing dynamic testing and/or tuning of the receivers incorporated in the tools. Furthermore, there is a need in the art for methods of testing receiver responses or to tune or calibrate the receivers during routine operation.

Acoustic LWD tool having receiver calibration capabilities


Disclosed are methods and systems of executing securities trades. An exemplary system comprises a server system that is in communication with a client system, a security data source, and a trade execution location. The security data source provides security data relating to a plurality of securities to the server system. The client system provides user specific criteria to the server system. The server system then analyzes the security data based upon the criteria, identifies user preferred securities from the plurality of securities, and provides the client system with data relating to the user preferred securities. The client system uses N user specific parameters to generate and display an N dimensional graph that is populated with icons representing the user preferred securities. After a user preferred securities is selected from the graph and an order is requested, the client system sends the order to the server system.

Without limiting the scope of the present invention, its background will be described with regard to trading common stock, as an example.
In trading common stock, there are three fundamental factors an investor must consider. These factors are what stock to trade, when to open a position in the stock and when to close that position in the stock. There are enumerable models that attempt to help the investor identify these factors each of which are based upon particular criteria. Some of the models are best suited for the long term investor using a buy and hold approach. Other models are better suited for the short term investor including, for example, the active investors that open and close positions in the same day or week.
In determining what stock to trade, a typical long term investor may perform substantial research into a particular company in an effort to evaluate the future success of that company. For example, a long term investor may evaluate whether the company has products or services that are likely to have an increase in sales, the effectiveness of a company's research and development, the profit margin of the company, the size and effectiveness of the company's sales organization, labor relations within the company, the quality of management personnel at the company, the competitiveness of the company in relation to other companies in the industry and long range outlook for profits.
In addition to these business related factors, the long term investor may look at factors such as whether the company typically pays dividends on common stock, the price to earnings ratio of the stock and the market capitalization of the company as well as earnings, revenue and net income of the company. On the other hand, an investor that is interested in short term investments may not perform such detailed research and instead may focus on factors such as volume of trades, proximity to a milestone such as a fifty two week high, difference between current volume and a historical volume, number of daily highs or money flow in identifying a stock of interest.
Once an investor has identified a stock of interest, the investor must then determine when to open a position in that stock. A long term investor might, for example, buy the stock regardless of price if it is being offered by a good company in a good industry banking on long term growth.
Alternatively, a long term investor may monitor factors such as business cycles, the trend of interest rates, governmental attitudes and the direction of inflation in making such a decision. The short term investor, however, may be more interested in such factors as the volatility of the stock or the liquidity of the stock in making such a decision.
The next step for an investor once they have opened a position in a stock is to determine when to close that position. A long term investor may, for example, make a decision to sell a stock based upon factors such as a fundamental change in a company that does not comport with the investor's original criteria for buying stock in that company, a change in management in the company, under performance of the stock, the stock reaching an unacceptable low, a belief that the stock has peaked or simply a belief that another investment has better long term prospects. While some of these factors may also be important to a short term investor, a short term investor may focus more heavily on such factors as the continued momentum of the stock or simply making certain all open positions are closed by the end of a day.
Regardless of the investment strategies, however, these three factors, what to stock to trade, when to open a position in that stock and when to close the position in that stock remain key elements in any successful investment strategy. Therefore, a need has arisen for a system and method for identifying stocks that meet specific criteria selected by the investor. A need has also arisen for such a system and method that allows the investor to execute trades in those stocks that meet the investor's criteria.

Method and system for executing trades in a user preferred security


A logic circuit is provided for a memory device which can be operated at a high speed with a lower voltage power source level than conventional devices. This logic circuit can be used in a multi-bit test circuit executing the wired-OR-logic operation of complementary logic signals from a plurality of pre-sense amplifiers, receiving the output of the wired-OR-logic operation by an emitter follower using a bipolar transistor, and outputting an AND signal of the complementary logic signals by a level comparing circuit. A sense amplifier is also provided for executing the wired-OR-logic operation of complementary logic signals from a plurality of pre-sense amplifiers, raising the level of the output of the wired-OR-logic operation by a level shift circuit having a semiconductor element for applying an inverse bias potential to an input signal, executing the wired-OR-operation of the shifted up output and outputs from other blocks, and receiving and amplifying the output of the wired-OR-logic operation.

1. Field of the Invention
The present invention is used in a memory device and relates to a circuit for logic processing.
More specifically, the invention particularly relates to a memory circuit of a logic gate circuit increasing levels of input logic signals and providing AND (NAND) logic output of the input signals, being preferably used for a test circuit for executing parallel tests of a memory cell (multi-bit test).
Further, the invention particularly relates to a memory circuit of a sense circuit selecting and amplifying output data of a memory cell selected from plural memory cells corresponding to one line of an output data bus of a semiconductor memory device, in accordance with a read out address.
Furthermore, the invention particularly relates to a memory circuit having a sense circuit selecting output data, in accordance with a read out address, by processing a wired-OR operation of outputs of each of pre-sense amplifiers for amplifying outputs of each group of memory cells, all memory cells being divided into plural groups.
2. Description of the Related Art
Conventionally, for such a semiconductor memory device having a comparatively large memory capacity and high speed operation performance as an SRAM, BiCMOS-SRAM, etc., a test of data writing in and reading out is carried out for the whole group of memory cells in order to confirm the operations of all memory cells arranged in an array composition. Such a test does not need much time if a memory capacity of a semiconductor memory device is comparatively small. However, recently the memory capacity of a semiconductor memory devices, that is, the number of memory cells, has considerably increased, and the time required for the test has greatly increased. As such, the test becomes a much time consuming task.
On the other hand, parallel test circuits of memory cells (multi-bit test) have lately developed for solving the problem of increase of the test time, by executing the test for a group of memory cells in parallel.
In FIG. 8, an example of conventional parallel test circuits executing the multi-bit test is shown. The example conventional parallel test circuit has such a structure that the third ECL circuit 60 is put on the first and the second ECL circuits 58 and 59, as the test circuit 54 is viewed from the side of a power line. Then, if a voltage of the power source decreases, for example, near to 2.5 V, operational margins of the two bipolar transistors are lost, which causes such a problem that a correct XOR processing of input signals can not be executed and the parallel test (multi-bit test) becomes impossible.
In the following, the above-mentioned problem is explained more in detail. Signals sent in a pair of common data bus lines 51 are distributed and sent to the test circuit 54 and MSA 53 via a signal distributing circuit 52. Voltages of the distributed signals A and B to the test circuit 54 are reduced by 2.times. Vbe (where Vbe is a voltage decrease between a base and an emitter of a transistor) from a voltage of a higher side power source (Vcc). Then, since a voltage margin of 2.times. Vbe is needed for the two stages of the bipolar transistors and the voltage margin of Vs for the third ECL circuit 60, in the test circuit 54, the operational voltage of (4.times.Vbe+Vs) is totally required. If Vbe is 0.8 V and Vs is 0.4 V, then the needed operational voltage is 3.6 V (=0.8.times.4+0.4).
As mentioned above, if the voltage of a power source decreases near to 2.5 V in the parallel test circuit of memory cells, an correct XOR processing of input signals can not be executed, and consequently the parallel test of memory cells (multi-bit test) becomes impossible.
The above-mentioned point is true, but it is possible to provide only one stage of the emitter follower by reducing the number of the emitter followers to the input nodes of the test circuit 54, in the above-mentioned parallel test circuit of memory cells. However, even by using only one stage of the emitter follower, since the required operational voltage of the test circuit 54 is 2.8 V, a correct XOR processing of input signals can not be also executed, consequently the parallel test of memory cells (multi-bit test) becomes impossible if the voltage of a power source decreases near to 2.5 V.
Further, chip area has been is increasing according to the large increase of the memory capacity of a semiconductor memory device, and the wiring length in a chip, of a data bus for data reading out, becomes longer. Since a resistance R and a parasitic capacitance of the wiring in a chip increases in accordance with increase of the wiring length, the signal transmission delay by the wiring becomes larger, which impedes a high-speed data access.
Then, in order to decrease the parasitic capacitance by the data bus wiring of a sense circuit after a pre-sense amplifier, it is devised that an output signal of a collector node in a current switch of ECL (Emitter-Coupled Logic) included in a pre-sense amplifier is output to a data bus from an emitter node via an emitter follower (ISSCC, 91(SESSION 3/HIGH-SPEED RAM/PAPER WP 3.5)). Since the parasitic capacitance of a collector is considerably smaller than that of an emitter, which is clear from the structure of a bipolar transistor, the parasitic capacitance by the data bus wiring of a sense circuit after a pre-sense amplifier can be reduced by outputting the output signal from an emitter node.
Then, by the above conventional technique, a control circuit is provided to a base, for controlling the voltage of a base of an emitter follower in an output part of a pre-sense amplifier, and the voltage thoroughly lower than the usual signal level is applied to the base of an emitter follower in the pre-sense amplifier not including the memory cell corresponding to an address of the data to be read out. Therefore, since the difference between the transistor state in the case of including the selected memory cell and that in the case of not including the one clearly appears in the level of the output voltage (emitter voltage) of the outputting emitter follower, the output signals of the selected memory cell can be easily selected or specified by the wired-OR-logic operation of the output signals of the plural pre-sense amplifiers.
Then, it is possible to compose a sense circuit having a hierarchical structure wherein plural pre-sense amplifiers are adequately divided into plural groups, and the wired-OR-logic of the output signals in each one of the groups is executed, and further the wired-OR-logic operation of the outputs of the wired-OR-logic operation of the groups via an emitter follower is executed and the wired-OR-logic operation is repeated by several stages. Therefore, by dividing the data bus lines of a sense circuit hierarchically into multi-stages, the RC delay can be reduced. To be more precise, the RC delay is decided by the RC between the former stage of an emitter follower and the present stage of an emitter follower, the wiring length between the two stages of emitter followers is effectively reduced.
However, the output voltage of an emitter of an emitter follower is reduced by the voltage decrease of Vbe (for example, about 0.8 V) between a base and a emitter, to the signal level input to a base of the emitter follower. Then, if the wired-OR-logic operation of signals divided into multi-stages is sequentially executed via multi-stages of emitter followers, the signal voltage is largely decreased. And, sometimes, the signal voltage decreases under the lower limit operational voltage of a sense amplifier provided at the final stage or the next stage of an emitter follower. For example, in case a sense amplifier is composed by using a current switch of ECL, the lower limit level of an input signal input to the current switch is 1.2 V where the voltage decrease between a base and an emitter is 0.8 V and the required minimum operational voltage of a constant current source connected to an emitter of the current switch is 0.4 V. Therefore, if the voltage of a power source of a memory apparatus is 3.3 V, it is impossible to compose more than 3 stages of the wired-OR- logic via an emitter follower including an emitter follower of the output part of each pre-sense amplifier, which restricts the realization of many stages of the data bus lines and further the high-speed data access.
On the other hand, if it is intended to decrease the power voltage for reducing the consumed power, the high-speed data access is impeded since the realization of many stages of the data bus lines is restricted.
Further, there is a method of increasing the signal voltage decreased in an emitter follower by a shift-up circuit using a current switch. However, the voltage signal increased by a current switch has a constant level independent of the level of an input signal. Therefore, the output signal of the selected pre-sense amplifier can not be distinguished from the output signals of the other non-selected pre-sense amplifiers since the increased level of the selected output signal has the same level as the non-selected output signals in spite of having a level higher than those of the other output signals before being increased. That is, since the original relative level relations among the output signals of the pre-sense amplifiers are lost, the output signals from the selected memory cell can not be specified by executing the wired-OR-logic operation of the output signals increased by the current switches, of the pre-sense amplifiers. Therefore, in the case of increasing the output signals by the current switches, the sense circuit becomes complicated since a logic circuit for specifying the output signals from the selected pre-sense amplifier among the increased output signals is necessary.

Logic gate circuit and parallel bit test circuit for semiconductor memory devices, capable of operation at low power source levels


The invention provides an intracavitary ultrasonic scanner with a helical scan. Mechanical and electronic steerable array implementations of the helical scan are described. A plastic cover sheath, filled with coupling fluid, covers the probe of the scanner. Portions of probe are porous allowing the coupling fluid to penetrate to the outside of the sheath. An improved polar coordinate decoding system provides an accurate control of the scan and allows storage of scan information in voxel memory.

Ultrasonic scanning systems which use pulse-echo ultrasound to provide information regarding the position, configuration, composition, and other internal features of human body organs are widely used in medicine. There are some anatomical situations in which improved ultrasonic images can be obtained by scanning from within the bodily cavities and vessels. Intracavitary ultrasonic scanners have been extensively described in the literature, e.g., in U.S. Pat. No. 4,869,258 of W. Hetz. Common types of intracavitary scanners are available for insertion into a rectum, vagina, and alimentary tract. Intracavitary scanners permit close contact with the region of interest, allowing higher ultrasonic frequencies to be used thus providing better resolution than extracorporeal scanners. Intracavitary scanners can also avoid problems with overlying structures, especially bone and those containing gas. A device technologically related to intracavitary scanner is an intravascular ultrasonic scanner such as described in U.S. Pat. No. 5,000,185 of P. G. Yock used for examination of blood vessels.
Both intracavitary and intravascular scanners comprise a probe-like shaft used to place a scanning transducer, located at a tip of the shaft, at the desired location inside the bodily cavity or vessel. Both scanner categories are therefore often referred to as probe scanners, such nomenclature having been used, e.g., in U.S. Pat. No. 4,972,839 of B. A. Angelsen and in U.S. Pat. No. 4,930,515 of R. A. Terwilliger.
To aid in the following description, it is convenient to define a cylindrical coordinate system where the z axis coincides with the axis of the shaft at its tip, r is the radial direction from the shaft axis, and .THETA. is the rotational angle measured around the shaft axis. A voxel (volume element) in such a cylindrical coordinate system is identified by a parallelepiped of the size dr.sub.i, r.sub.i .multidot.d.THETA..sub.j, and dz.sub.k, centered at the r.sub.i, .THETA..sub.j, and z.sub.k coordinates. The scanned volume can then be divided into closely fitting voxels, each identified by its coordinate values of r.sub.i, .THETA..sub.j, and z.sub.k.
Many display modes are being used in probe scanners. The closest art to the present invention is a plan position indicator (PPI) mode: It is an r,.THETA. polar coordinate display where the radial distance r corresponds to radial ultrasound beam echo delay time, the rotational angle .THETA. corresponds to the beam rotation around the axis of the shaft, and intensity corresponds to a processed amplitude of an echo signal at each position of r and .THETA.. The PPI mode limitation to an r,.THETA. display plane represents a serious shortcoming. For example, a rectal scan of a prostate then produces only a single cross-sectional plane of the organ, which limits its diagnostic value. By manual insertion or retraction of the shaft, one can obtain the r,.THETA. display in planes corresponding to different values of z along the axis of the shaft, yet each presentation remains in an r,.THETA. plane.
There are several requirements for accurate registration in the three-dimensional cylindrical coordinate system r,.THETA.,z needed to establish an accurate correspondence between anatomical features and their scanned voxel value as stored in the computer memory voxel space: one requirement is that the transducer and the shaft be moved along a straight z axis identifiable with respect to the cavity; another requirement is that the transducer orientation be such that the beam direction is truly radial. Yet another requirement is that the axial (z) coordinate and the rotational (.THETA.) coordinate of the beam be accurately determined.
Current PPI-type probe scanner devices have no means to control the z-axis motion within the cavity. Further, in current scanner practice, measurement of the shaft position coordinates is typically made at the proximal base of the shaft. The shaft design is therefore a compromise: the shaft needs to be flexible enough to follow the possibly convoluted path required to reach the desired location in the bodily cavity, yet rigid enough to minimize the error in coordinates between the decoders at the proximal shaft base and the transducer at the distal shaft tip. When the shaft is relatively short, straight, and rigid, this technique works well. However using this method, it is difficult to design scanners for distant organs e.g., for the uterus where the shaft has to be long and flexible; in such cases, due to the dynamics of torque transmission, there is a variable delay in the rotational angle between the proximal and distal ends of the shaft, leading to an error in the measured value of the .THETA. scan coordinate. In order to bypass the error between the proximal angle measurement and the distal value of the .THETA. coordinate, U.S. Pat. No. 4,880,011 of S. Imade et al uses a decoder located at the distal catheter end. Imade's decoder adds significant bulk to the scanner.
An alternative to a mechanical rotation is an electronically steerable circular array of sensors, which by electronic switching and phase shifting accomplishes beam rotation. Such arrays for ultrasonic probe application, working in a circular PPI mode, have been described in the literature (e.g., see "A 100-Element Ultrasonic Circular Array For Endoscopic Application in Medicine and NDT" by H. P. Schwarz et al in the Annual International Conference of the IEEE Engineering and Biology Society, Vol. 12, No. 1:287-290, 1990). A steerable circular array still requires mechanical motion in the z direction.
In state-of-the-art ultrasonic probe scanners, voxel space storage and processing is not used, largely due to registration errors; the display of the probe scan is in real time, i.e., the information displayed is obtained from the scanner data with only minimal processing delay. A shortcoming of such presentation is that the repetitive stream of scan data is irretrievably two-dimensional, and cannot be used to improve the resolution or to reduce "speckle". "Speckle" is a random scintillation pattern on the display, an artifact unrelated to the anatomical structure, resulting from an interference between the waves backscattered from within the coherent ultrasonic resolution cell.