A valve positioner system with zero bleed at steady state is disclosed. The system has a pilot valve, the operation of which is controlled by an electronic circuit powered from a signaling and power connection of a positioner device. A plurality of pneumatic valves are activated and deactivated by the pilot valve to control a valve actuator. With varying configurations and arrangements of normally open or normally closed pilot valves and pneumatic valves, fail freeze and fail safe operations are contemplated. The activation and deactivation of the pilot valve is controlled by an electronic circuit that monitors a valve position signal.

1. Field of the Invention
The present invention relates generally to control systems for industrial processes, and more particularly, to pneumatic valve positioning systems and electrical circuits thereof with steady state gas bleed prevention.
2. Description of the Related Art
Many industrial processes involve the movement of fluid such as gas, steam, water, and chemical compounds. The flow of the fluid is regulated by a control valve that has a passageway that is selectively opened and closed with a movable obstruction or valve element connected to a stem. An actuator, in turn, is connected to the stem, and provides the motive force to open and close the valve element. Pneumatic, hydraulic, electrical, or mechanical energy is converted by the actuator to linear or rotational motion, depending on the configuration of the control valve.
A conventional pneumatic actuator is comprised of a piston sealed within a cylinder, and the piston includes a connecting rod that is mechanically coupled to the valve element. Compressed gas is forced into and out of the cylinder to move the connecting rod, which is mechanically coupled to the stem of the control valve. In a single-acting actuator, the compressed gas is taken in and exhausted from one end of the cylinder and is opposed by a range spring, while in a double-acting actuator, air is taken in one end of the cylinder while simultaneously exhausting it out of the opposing end.
Precise and accurate control of the valve actuator, and hence the valve element, can be achieved with a positioner device coupled thereto. Pneumatic valve positioners, which can cooperate with aforementioned pneumatic actuators, are well known in the art. The proportional movement of the actuator is accomplished by the movement of compressed gas into and out of the actuator piston. More particularly, valve positioners incorporate a spool (or other devices) that either rotates or slides axially in a housing to port the flow of compressed gas to the actuator or to one or more exhaust ports.
An electrical control circuit provides a variable current signal to the positioner device that proportionally corresponds to particular states of the actuator and hence a particular position of the control valve. The electrical control circuit and the electrical current signals generated thereby may be part of a broader process managed by a distributed control system (DCS). Generally, the electrical current varies between 4 milliamps (mA) and 20 mA according to industry-wide standards; at 4 mA the valve positioner may fully open the valve element, while at 20 mA the valve positioner may fully close the valve element. The positioner compares the received electrical signal to the current position of the actuator, and if there is a difference, the actuator is moved accordingly until the correct position is reached.
One previous solution involves an external component that monitors the variable current signal for the electrical control circuit and the actual position of the valve element, and responds by driving a lower power solenoid valve coupled to the valve actuator. These additional external components tend to be costly, and require a safe external power source with associated connectivity components. Along these lines, additional wiring and a separate junction box is required. In general, there are additional complications and costs, particularly for deployment in hazardous environments.
Another previous solution utilizes a valve positioner having normally closed on/off valves. However, the flow coefficient (Cv) of such valves is low, and oftentimes necessitate boosters for meeting stroking time requirements of most typical deployments. Furthermore, such boosters are also understood to exhibit some degree of leakage, largely negating the advantages of normally closed valves. In any case, the position of the valve actuator must be restored.
Accordingly, there is a need in the art for an improved valve positioner having zero bleed in a steady state position, and having such capability regardless of the flow coefficient of the positioner. It would be desirable for the valve positioner to be powered by the electrical current signal loop and not an external source, and therefore intrinsically safe.

Valve positioning system with bleed prevention


Systems and methods for push button configuration of devices are provided. One system comprises one or more circuits configured to determine that a configuration button on the second device has been activated and determine whether a configuration button has been activated on a first device or a third device within a time interval from a time at which the button on the second device is activated. The circuits are configured to, in response to determining that the configuration button has been activated on either the first device or the third device within the time interval, allow the second device to be authenticated. The circuits are configured to, in response to determining that the configuration button has not been activated on either the first device or the third device within the time interval, prevent admission of the second device. The network may be a wired network, such as a MoCA network.

Installing networking and multimedia devices into multiple rooms of a house (or other structure) is often very expensive due to the need to rewire the house and the need to purchase multiple devices, such as multiple set-top-boxes and network access points, to accommodate the multi-room installation. Multimedia over Coax Alliance (MoCA) is a standard that seeks to address these problems. MoCA enables connecting devices over the existing coaxial cable that is present in many homes and other structures. MoCA enables distributing multimedia pretty much anywhere in a structure where there is an existing coaxial outlet. MoCA connects devices of various types such as televisions, set-top-boxes, computers, routers, and network access points. MoCA, however, is a relatively new standard that still lacks features that could improve usability.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.


A process for preparing a printed circuit board. The process involves successive steps of coating a photosensitive electrodeposition coating composition onto a printed-circuit copper-clad, laminated base plate to form a photosensitive resist film, applying a pattern mask onto the photosensitive resist film, exposing to an active light, developing and etching. Also the printed-circuit copper-clad, laminated base plate is subjected to a corrosion preventing treatment after cladding or laminating and prior to the step of coating the electrodeposition coating composition thereonto with a nitrogen-containing heterocyclic compound as a corrosion inhibitor.

(1) Field of the Invention:
This invention relates to a process for preparing a printed-circuit board, and more particularly to the improvement which comprises applying a corrosion preventing treatment with a specified corrosion inhibitor to a printed-circuit copper-clad base plate prior to subjecting the printed-circuit copper-clad base plate to an electrodeposition coating, resulting in preventing the eluation of copper from the printed-circuit copper-clad base plate upon effecting the electrodeposition coating, thereby preventing such phenomena as incomplete developing onto the printed-circuit board, with the further results of completely protecting the corners and interior of through-holes, and preparing a precise printed-circuit board.
(2) Description of the Prior Art:
The process for preparing a printed-circuit board, which comprises coating a photosensitive electrodeposition coating composition onto a printed-circuit base plate, is known (see, for example, U.S. Pat. Nos. 3954587, 4592816, 4632900 and 4673458; Japanese Patent Application Laid-Open Nos. 207139/85, 206293/86 and 6070/88, etc.).
The process for preparing a printed-circuit board according to the electrodeposition coating process has such advantages that automation is made possible, that a uniform film is obtained and so forth, and it is an industrially advantageous process. However, corrosion of the printed-circuit base plate at the time of carrying out the electrodeposition coating cause abnormal depositing of the film onto the corroded area or the failure of forming the film onto the corroded area, resulting in abnormal phenomena which may take place at the time of developing. Particularly, in the case of preparing a precise pattern, various phenomena such as disconnection, deficiency of pattern, shortcircuiting and the like may take place, resulting in defective printed-circuit boards.

Process for preparing printed-circuit board


A flow injection electrochemical detecting device has a base (10), a cover pivotally mounted on the base (10), and a locking device attached between the base (10) and the cover (20). The base (10) has a recess (12) defined in a top to accommodate a working electrode inside the recess (12). An annular trench (28) in a bottom partially receives an O-ring (282) serving as a separator to form a space between the base (10) and the cover (20). Multiple channels are defined through the cover (20) to communicate with the space. Therefore, a flow injection electrochemical detecting device is achieved. By pivotally attaching the cover (20) on the base (10) and using the locking device, the detecting device is easily opened or closed to change the working electrode (50) in a convenient way.

1. Field of the Invention
The present invention relates to an electrochemical detecting device for a fluid, and more particularly to an electrochemical detecting device in which an electrode can be changed quickly and easily.
2. Description of Related Art
An electrochemical detecting device is a burgeoning object in chemical studies and has high scientific value to provide considerable economical benefits, because the electrochemical detecting device is widely applied in various fields of science and technology. A good detecting device needs to have excellent selectivity, sensitivity, and short detecting time and further have excellent stability and reliability. In order to reduce the quantity of testing samples as less as possible in the electrochemical detecting device and also to simplify the operational procedure, the electrochemical detecting device is minimized in size and designed to satisfy these requirements. Additionally, the electrochemical detecting device can be easily combine with various electrodes to the trace analysis in different fields such as bio-chemistry, environmental estimation, drug control, cosmetic control etc. It can also combine with flow injection analysis (FIA), high performance liquid chromatography (HPLC), or capillary electrophoresis (CE) to increase the sensitivity in detection.
With reference to FIG. 9, a conventional electrochemical detecting device comprises a base (60), a cover (70), a working electrode (80) and a compartment layer (90).
The base (60) has a top (not numbered) and two positioning holes (62) vertically defined through the base (60). The working electrode (80) is mounted on the top of the base (60) and has two through holes (82) respectively aligning with the positioning holes (62) of the base (60). An inner lead (83) and an outer lead (84) electrically connect with each other and are attached on the working electrode (80) between the two through holes (82).
The compartment layer (90) is mounted on the working electrode (80) and also has two through holes (92) respectively aligning with the positioning holes (62). A rectangular channel (94) is defined between the two through holes (92) in the compartment layer (90) and accommodates the inner lead (83) inside the rectangular channel (94).
The cover (70) is mounted on the compartment layer (90) and has a bottom (not numbered) and two posts (76) extending from the bottom to respectively penetrate through the through holes (92, 82) of the compartment layer (90) and the working electrode (80). Two bolts (762) are respectively attached to the posts (76) to firmly clamp the working electrode (80) and the compartment layer (90) between the cover (70) and the base (60). Whereby, the channel (94) of the compartment layer (90) defines a space (not numbered) for liquid. An inlet (72) and an outlet (74) are defined in the cover (70) to communicate with the space for entry or exit of the liquid.
When the electrochemical detecting device operates, the detected liquid is injected into the space via the inlet (72) and the outer lead (84) is electrically connected with a readout system. Whereby, the inner lead (83) enables transmission of chemical data (for example: capacitance) to the readout system via the outer lead (84).
However, the conventional electrochemical detecting device still has some drawbacks in operation caused from the structure. For example, changing the working electrode (80) is troublesome since the bolts (762) have to be individually detached from the posts (76) to take the working electrode (80) out when assembling or disassembling the device. More particularly, if the working electrode (80) is disposable in nature, it has to be changed very often. Additionally, the working electrode (80) and the compartment layer (90) both must be punched to define through holes (82, 92) to allow the posts (76) to penetrate there through which also causes more trouble in the manufacturing processes.
The present invention has arisen to mitigate or obviate the disadvantages of the conventional electrochemical detecting device.

Flow injection electrochemical detecting device


A dishwasher that fits within the conventional U.S. residential dishwasher counter space and uses the conventional U.S. residential power supply not only achieves within a convenient cycle time the same standard of sanitation as set forth for commercial hot water sanitizing dishwashers, but substantially surpasses the same.

The present invention relates to a dishwasher, and more particularly to a dishwasher which fits within the counter space typically available for a U.S. residential dishwasher and is operable on a U.S. residential power supply, yet meets the high sanitary requirements of a commercial dishwasher within a convenient cycle time.
Washing involves subjecting the surfaces of the dishes to sprays of a hot water and detergent solution for the purpose of removing food, grease, and other soiling material. Rinsing is the application of hot water to the surfaces of clean dishes.
Etching is a problem with glassware. Etching is the process through which a cloudy film develops on glasses over time. Etching is caused by a combination of several factors, including water hardness, soap, temperature and length of time at which the glassware is exposed to elevated temperatures. Given that soap and water hardness are relatively constant for a residential dishwasher, it is desirable to avoid holding glassware under high temperatures (above 150° F.) for extended periods of time (over 20 minutes). Preferably, dishwashers should not subject glassware to temperatures over roughly 150° F. (66° C.) for longer than roughly 20 minutes—or they will induce an unacceptable amount of etching. These standards are not specifically defined, however, since the exact conditions under which etching occurs are not precisely known and vary for different glassware products.
A commercial hot water sanitizing dishwasher must comply with the joint International Standard set by the NSF (National Sanitation Federation) and ANSI (American National Standard Institute)—namely, NSF/ANSI 3-2001. This commercial hot water sanitizing dishwashing machine standard is postulated in terms of three tests: First, the complete cycle shall render dishes free of soil and detergents. Second, the complete cycle shall deliver a minimum of 3,600 HUEs (heat unit equivalents at the surface of the dishes), with varying amounts of HUEs (as set forth in a chart) being added for each second that the surface of the dishes is at a temperature above 143° F. during the wash/rinse cycles. Third, for a hot water sanitizing machine having a stationary rack (as opposed to a conveyer) the machine shall provide either a single temperature of a 165° F. (74° C.) for both the minimum wash temperature and the minimizing rinse temperature or a dual temperature of 150° F. (66° C.) for the minimum wash temperature at 180° F. (82° C.) for the minimum sanitizing rinse temperature. In both instances the sanitizing rinse pressure should be at a pressure of 20 psi±5 psi±(138 kPa±34 kPa).
Accordingly, most commercial hot water sanitizing dishwashers today (e.g., a door-type Jackson TEMPSTAR dishwasher) use a fairly high volume (e.g., about eight gallons) of recirculating water under fairly high pressure (about 20 psi) at at least 150° F. to wash for roughly about 45–48 seconds (6.5 HUEs/sec.), then rinse with water at at least 180° F. for roughly about 11–12 seconds (346.8 HUEs/sec.). Such dishwashers have a complete cycle time of about one minute, generate about 4,107 HUEs, and are said to operate under the dual temperature (150° F./180° F. wash/rinse) implementation of the sanitization standard. However, other commercial hot water sanitizing dishwashers implement the sanitization standard by using 165° F. water for both the wash cycle and the rinse cycle. As all temperatures above 165° F. have a value of 346.8 HUEs, a combined wash/rinse period of 11 seconds at at least 165° F. generates about 3,814 HUEs. Such dishwashers are said to operate under the single temperature (165° F./165° F. wash/rinse) implementation of the sanitization standard.
Commercial dishwashers in the United States (and even residential dishwashers in many European countries) are capable of meeting such stringent requirements in minutes or less since they have available to them an ample 220/240 volt, 30–40 amp power supply. On the other hand, a residential dishwasher in the United States typically has available to it only the customary 110–120 volt, 15–20 amp household power supply. Accordingly, the conventional U.S. residential dishwashing systems cannot attain either the 150° F./180° F. or the 165° F./165° F. implementation of the sanitization standard for U.S. commercial dishwashers unless the dishwasher cycle extends for an inordinate amount of time, presumably at least about 90 minutes. The hot water available to a U.S. residential dishwasher is typically at 120° F.–140° F., 120° F. being the most common and 140° F. being the common practical maximum. Accordingly, unless there is a dedicated hot water heater external of the dishwasher to increase the temperature of the hot water supply available to the dishwasher, it is difficult, if not impossible, for the dishwasher—by virtue of its sump reheater alone—to raise the surface temperature of the dishes to above 143° F. and maintain them at that temperature (as necessary to accumulate HUEs) within an acceptable time for a residential dishwashing cycle. Thus, for the most part, U.S. residential dishwashers, even those taking an hour or so for the complete cleaning cycle, do not accumulate any HUEs, let alone enough to meet the sanitization standard.
Informal industry standards and experience for U.S. residential dishwashers dictate, first that there be at least four cycles—including a bathe cycle, at least one wash cycle, and at least one rinse cycle—to achieve effective cleaning of soiled kitchenware. Each cycle requires at least 1.5 gallons of water, typically 1.5–2.0 gallons, in order to obtain the desired cleaning. Second, the dishwasher must be able to operate with the limited U.S. residential power supply (110–120 volt, 15–20 amp power supply) and with the common maximum hot water supply available thereto (140° F.). Third, the dishwasher must operate within a convenient cycle time, and in any case a cycle time which does not involve subjecting glassware to temperatures over roughly 150° F. for longer than about twenty minutes in order to avoid etching of the glassware. Taken in combination, these three informal industry standards—four cycles, limited power, and limited time—pose rather difficult restrictions on the U.S. residential dishwasher, as each of the four cycles involves the introduction of at least 1.5 gallons of water at a maximum of 140° F., which water must be brought up to a higher temperature within a limited period of time using a limited power supply. Complicating the problem of bringing the water to appropriate sanitizing temperatures is the fact that each cycle of the U.S. residential dishwasher—whether bathe, wash, or rinse—begins with the introduction of water which is typically at a maximum of 140° F. The conventional heating element in the recirculating sump of the U.S. residential dishwasher has available to it only about 500–800 Watts of power (that is, the standard U.S. residential electrical power input minus the amount of power required to run the sump recirculating pump and controls). Thus, the sump heating element can typically provide an increase in temperature of the system (that is, the approximately 52 lb. of water, kitchenware to be washed, and dishwasher cavity surfaces) of less than 1° F. per minute.
The conventional heating element of a dishwasher (located in the recirculating sump) must raise the temperature of not only the 1.5–3.0 gallons of water present in a given cycle (equivalent to 12–24 lbs. of water), but also the kitchenware to be cleaned, including dishes, pots, pans, silverware and like kitchen utensils (about 20 lbs.), and the cavity/rack/spray-on system of the dishwashing cavity (about another 20 lbs.). The power supply must not only feed such heating element, but also perform the non-heating functions of the dishwasher—e.g., driving the pump that circulates the water under pressure into and around the cavity, driving the controls of the consumer interface, and the like. Thus it is not surprising that the time required to meet either implementation of the sanitization standard would be longer than an hour for a U.S. residential dishwasher.
Separate and apart from the constraint imposed on a U.S. residential dishwasher by the limited power supply available, there is also a constraint on the size or volume of a U.S. residential dishwasher. Both builder-supplied dishwashers (for new home construction) and replacement dishwashers are expected to fit within a given volume of "counter space," which has become standardized over time at 35″×24″×23″ to provide a dishwasher cavity of about 7 cubic feet. The standard volume evolved in a way that allowed the dishwasher to fit under a counter at the standard kitchen counter height, with a door at a height at which consumers felt comfortable loading dishes, and a combined height and width that didn't take up too much "cupboard" space yet held a reasonable number of dishes. Taking into account the height of the lower tray rollers, the thickness of the door itself, and the space between the bottom of the lower tray and the bottom of the dishwasher cavity leaves approximately 9 inches between the floor and the bottom of the dishwashing cavity. Within this limited height must fit all the working parts of the dishwasher (e.g., inlet water connection, electrical power connection, inlet water valve, motor, valves, hoses, controls, etc.) external of the dishwashing cavity. Any advancement in dishwashers which does not fit within the existing industry standard for "cupboard space" will simply not be commercially viable. Fortunately, due to technological advances in plastics forming, motor controls and the like, the size of the working parts of dishwashers has shrunk over time since their introduction, and, as a result, some of the space under the dishwashing cavity and above the floor is now available for improvements in the residential dishwasher.
Accordingly, it is an object of the present invention to provide a sanitizing dishwasher which in one preferred embodiment operates on a conventional U.S. residential power supply.
A further object is to provide such a dishwasher which in one preferred embodiment occupies only the conventional U.S. residential dishwasher cupboard space.
Another object is to provide such a dishwasher which in one preferred embodiment substantially surpasses the joint NSF/ANSI standard for commercial hot water sanitizing dishwashers.
It is also an object of the present invention to provide a dishwasher which in one preferred embodiment has a cleaning cycle which is effective for sanitization purposes, yet shorter in length than the non-sanitizing cleaning cycle of the conventional U.S. residential dishwasher.
It is another object to provide such a dishwasher which in a preferred embodiment fits within the conventional U.S. residential dishwasher cupboard space and uses the conventional U.S. residential power supply, but achieves within a convenient cycle time the same standard of sanitization as is set for commercial hot water sanitizing dishwashers.
It is a further object to provide such a dishwasher which is simple and inexpensive to manufacture, use and maintain.

This patent is subject to a terminal disclaimer.


A system and method for transmitting a message generated by a message source to diverse communication devices. The types of communication devices to receive the message and their respective sites are selected in response to message parameters contained in the message file. The message is converted to a format appropriate for communicating with selected communication devices and then automatically transmitted to the selected sites.

The present invention relates generally to communication systems. More particularly, the invention relates to a system in which messages generated by a message source are automatically converted to the proper mediums for transmission to various types of communication devices used by selected recipients.
In today's world, many different modes of communication have become commonplace. By way of example, people often communicate via e-mail, voice mail or facsimile. In addition, people may employ many different data services to handle their electronic or voice mail. Although a great technological advance, the availability of these various modes of communication has spawned inefficiency since sending messages to or receiving messages from diverse sources has grown increasingly complex.
Known prior art systems have attempted to address this inefficiency. For example, one system discloses a unified messaging system in which a user has unified access to any messaging service. All messages to a specified user, regardless the source, are automatically routed to a user-designated messaging mailbox. The mailbox notifies the user that a new message has been received. In the event the message could not be forwarded to the mailbox, the notification relays the information that the message is waiting on another service. Although, the unified messaging system addresses the problem of receiving messages from diverse sources, it does not offer a solution for efficiently sending communications to diverse sources.
In today's workplace, efficient communication with many different individuals or groups of people has become paramount. Unfortunately, as not everyone communicates via the same type of communication device, a single message intended for many different recipients often cannot be sent using a single mode of communication. For example, a manager at a facility employing both office workers and assembly line workers might want to distribute a company-wide message. The manager can communicate with the office workers via e-mail, but can reach the assembly line workers only by posting the message on a bulletin board or displaying the message on a message marquee. Thus, to communicate with all the intended recipients, the message originator is forced to generate the same message repeated times using various modes of communication.
It would therefore be advantageous to provide a communication system that transmits a message generated by a message source to a variety of recipients communicating via diverse communication devices. The system would automatically convert the message to the appropriate communication format and transmit the message to the selected recipients at their respective sites. In addition, the system would include an open architecture that advantageously could receive message from diverse sources, whether originated by users using a variety of user interfaces or originated by automated sources, such as other software applications or hardware devices.


The present invention is an apparatus for curtain coating a composite layer formed from a plurality of coating compositions onto a moving receiving surface. Edge guides comprising two thin, parallel and closely spaced wires maintain the horizontal extent of the free falling curtain. A flushing and lubricating liquid is supplied to the edge guide. The present invention comprises a distribution body for delivering the flushing and lubricating liquid in laminar flow without initiating stationary waves in the curtain that lead to objectionable coating nonuniformities. The distribution body allows for replacement of the wires without its removal or disassembly. A horizontal conduit near the top of the curtain has an outlet face in contact with the wires that tapers in the upward and downward directions to horizontal edges. The wires pass across the outlet opening within its horizontal diameter. The upper edge of the outlet face positions and supports the wires.

In a curtain coating apparatus, a moving receiving surface is coated by causing a free-falling curtain of coating composition to impinge on the receiving surface to form a layer thereon. One curtain coating apparatus is described in U.S. Pat. No. 3,508,947 to Hughes wherein a composite layer comprising a plurality of distinct layers is formed on a slide hopper and dropped therefrom to form a free-falling curtain. The edges of the curtain must be held to maintain the width of the curtain; otherwise, the curtain narrows as it falls as a consequence of surface tension. To counteract surface tension and maintain curtain width, the curtain is placed in wetting contact with a substantially vertical solid support surface called an edge guide.
In the manufacture of photographic materials comprising many layers, the coated uniformity of the individual layers and the composite layer is critical. Layer uniformity must generally be better than about 2%, and uniformity may have to be significantly better than that over small areas such as a 35 millimeter film frame or over large areas such as the length of a motion picture film.
One source of coating nonuniformity that may occur arises from stationary waves in the curtain. These waves originate at the lateral and top edges of the curtain and propagate laterally into the main body of the curtain. Along the boundary of a stationary wave, the wave speed of propagation of curtain disturbances is in balance with the speed of the falling curtain. Where the wave boundary meets the support being coated, a nonuniformity in the form of a longitudinal streak may be observed in the coated composite layer. More generally, the uniformity of the coated layers can be affected everywhere beneath the wave boundaries. Whether a streak or more diffuse nonuniformity is objectionable depends upon its severity and upon the release specifications for the product.
Standing waves become more common as more layers are coated simultaneously and as the flow rate of the composite layer increases. There is a trend to coat more layers simultaneously to reduce cost and to accommodate new products with additional layers to provide features. There is also a trend to higher coating speeds to reduce manufacturing costs. Therefore, preventing loss of product to objectionable coating nonuniformities from stationary waves is becoming increasingly difficult.
Waves may originate at the hopper lip because of mechanical damage or contamination. Another cause of waves is a discrepancy between curtain trajectory and the profile of the edge guide at the hopper lip. Curtains formed asymmetrically, such as by a slide hopper, do not depart from the lip vertically downward except at low flow rates. More commonly, the curtain abruptly bends backward toward the hopper body at the hopper lip. If the first portion of the edge guide does not accommodate this change of direction, then a stationary wave may arise at the juncture of the edge guide and the hopper lip.
Waves most commonly originate at edge guides because of mechanical damage or their geometric configuration. Solidification of coating composition on the guide from the congealing or drying of coating composition can initiate waves. Such buildup can be reduced or eliminated by flushing the edge guide with a suitable solvent such as water and controlling ambient conditions including temperature, vapor pressure, and air motions. The low viscosity of the solvent also reduces the drag of the edge guide on the free-falling curtain. Coating latitude is compromised at the edges of the curtain if the velocity there is significantly reduced compared to the main body of the curtain because of drag. Curtain attachment to the full length of the edge guide is also compromised.
Introducing a liquid for flushing and lubricating the edge guide without introducing waves has proven difficult. A poorly configured distribution body can induce waves. Because of the very low viscosity of an effective lubricating liquid, the flow issuing onto the edge guide can be turbulent. Turbulent flow can create traveling waves in the curtain because the turbulent disturbances exciting the waves are moving and transient. If the lubricating liquid jets into the main body of the curtain, waves can also arise, and additional nonuniformity can result as the jet physically displaces the composite layer from the edge guide.
U.S. Pat. No. 4,830,887 discloses a means for introducing lubricating liquid shown in FIGS. 1a and 1b. The edge guide is a narrow tube, and the liquid is supplied to the top of the tube. The liquid issues from a long, narrow slit in the tube that is in wetting contact with the edge of the curtain. Such a narrow tube is prone to turbulent flow and plugging. Furthermore, tubes have proven less resistant to the formation of stationary waves than dual wires.
U.S. Pat. No. 4,974,533 discloses a means for introducing lubricating liquid shown in FIG. 1c. The liquid issues vertically downward from a tube with an opening adjacent to the edge guide. The edge guide is the edge of a plate in wetting contact with the curtain. Such narrow tubes are prone to turbulent flow, and plates have proven less resistant to the development of stationary waves and other edge nonuniformities than dual wires.
Edge guides preferably comprise two thin, parallel, closely spaced wires lying in a plane perpendicular to the hopper lip as disclosed in U.S. Pat. No. 5,328,726. The wires are supported only at the top and bottom of the edge guide. Wire edge guides have proven generally superior for curtain coating and in particular have demonstrated resistance to forming standing waves. Damaged wire is cheaply replaced. Flushed wire edge guides economically and practically solve the problems of buildup and drag. For distributing lubricating liquid to the wires, U.S. Pat. No. 5,328,726 teaches the use of a conduit with an opening directed vertically downward that encompasses the wires as shown in FIG. 1d. Again, so small a conduit is prone to turbulent flow. Additionally, running wires through the conduit complicates their replacement. The configuration is also prone to initiating a stationary wave at the lowermost and innermost edge of the distribution body, as shown in FIG. 2.
U.S. Pat. No. 5,358,569 teaches the use of a gradually curved conduit encompassing the wires with an opening directed vertically downward as shown in FIG. 1e. This reference teaches how to size the conduit and how to restrict its curvature to ensure laminar (i.e. not turbulent) flow. Running the wires through the conduit complicates their replacement. The configuration is also prone to initiating a stationary wave at the lowermost and innermost edge of the distribution body, as shown in FIG. 2.
U.S. Pat. No. 5,382,292 teaches supplying dual wire edge guides from small channels open to the atmosphere rather than from a conduit as shown in FIG. 1f. The channels provide laminar flow and allow time for the action of any surfactant in the lubricating liquid. The wires are more readily accessible for replacement. However, this distribution body may still initiate a stationary wave at the lowermost and innermost edge of the distribution body, as shown in FIG. 2.

Inlet for introducing water to wire edge guides for curtain coating


A shroud for supporting a variable vane in a compressor section for a gas turbine engine includes a pair of components which are secured together by a threaded fastener extending into a blind hole in one of the two components. Additional material forms on the component which includes the blind hole extends beyond a pivot axis for the vane such that there is an increased length of engagement between the threaded fastener and the blind hole. The blind hole eliminates the need for multiple nuts and reduces the radial height of the shroud to save additional weight.

This application relates to a shroud for a variable vane structure in a gas turbine engine, wherein the shroud is formed of two components connected together by a threaded fastener extending into a blind hole in one of the two components.
Gas turbine engines are known, and have a plurality of sections. Typically, a compressor section receives air and compresses that air. The air is delivered downstream to a combustor, and is mixed with fuel. The air and fuel is combusted, and the products of combustion are passed downstream over turbine rotors. The turbine rotors are driven to rotate.
The compressor section typically includes a plurality of rotor stages and intermediate stationary vane stages. The rotor stages each include a plurality of blades which have airfoils to receive and compress air, and deliver that air downstream. Intermediate each stage of rotor blades are stationary vanes. Under certain conditions it is desirable to redirect the airflow between the compression stages. Thus, the vanes have a variable profile, and may be caused to rotate on a pivot axis to control the direction of air from one compression stage as it approaches the next compression stage.
Such variable vanes are mounted in inner and outer shrouds. In the prior art, at least some of these shrouds have been formed of at least two separate components which meet along a flat mating surface at the pivot axis of the vane. This prior art structure has included a hole extending through both components. A threaded fastener, such as a bolt, extends through the hole, and a nut is secured at an opposed end of the hole. This structure requires a relatively great radial profile for the shroud, due to the nut.

Small radial profile shroud for variable vane structure in a gas turbine engine


A retroreflective article includes a prismatic film having prismatic elements with a metallized coating wherein the metallized coating is laser etched to provide one or more light transmissive regions to expose underlying material that one or more provides high contrast images that contrast with the retroreflective film. The underlying material can include one or more contrasting elements. The article may be back-lighted to increase the contrast especially during conditions of reduced lighting.

The following prior art patent documents are made of record: U.S. Pat. Nos. 4,005,538; 4,200,875; 4,634,220; 4,645,301; 4,650,283; 4,688,894; 4,691,993; 4,708,920; 4,972,061; 5,122,902; 5,151,572; 5,169,707; 5,213,872; 5,542,202; 5,620,613; 5,815,292; 5,885,677; 5,940,212; 5,962,109; 6,010,770; 6,153,128; 6,155,689; 6,217,175; 6,288,842; 6,484,637; 6,644,818; 6,767,609; 6,786,513; 7,033,677; 7,034,688; 7,445,347; Publication No. US2002/0034608; Publication No. US2005/0258637; Publication No. US2008/0092418; Publication No. US/20080212181; EP Patent 1477368; and UK Patent Application 2433637.
It is known to provide a retroflective article having a protective layer over a prismatic film having cube corner prismatic elements, wherein the prismatic elements are coated with an opaque, vapor-deposited, aluminum coating. The aluminum coating is backed by a pressure sensitive adhesive layer which is backed by an interleaf such as an acrylic or polyester layer. A coating of a permanent type adhesive is adhered to the underside of the interleaf layer, and a release liner is adhered to the underlying permanent type adhesive. The underside of the protective layer may be preprinted with a repeating pattern such as a brick pattern, with a zone of pre-printing, such as with clear colored ink, and with reverse printing at the clear color printed zone. While the preprinting, the preprinted zone and the reverse printing at the printed zone are visible against the prismatic retroflective film, the amount of contrast between the preprinting and the prismatic film was limited.
The reverse printing was a logo and/or text such as one indicating the source of the product. This reverse printing provided excellent contrast but had the limitation that only large amounts of material could be preprinted economically. Changes in design were also expensive and could not be done expediently.
What is needed therefore is an improved retroreflective article with having an image with an improved contrast and one which can be provided in an efficient and cost effective manner.


A superior ignitability is realized assuredly by specifying at least either of a relation in magnitude between absolute values of a plus-side voltage and a minus-side voltage and a relation in magnitude between absolute values of a plus-side current and a minus-side current when alternating current power is introduced. An ignition system includes a spark plug, a discharging power supply which applies a voltage to a spark gap of the spark plug to thereby generate an electric spark discharge and an alternating current power supply which introduces alternating current power to an electric spark generated by the electric spark discharge to generate an alternating current plasma.

A spark plug used in a combustion chamber of an internal combustion chamber includes, for example, a center electrode which extends in an axial direction, an insulator which is provided to surround an outer circumference of the center electrode, a cylindrical metal shell which is assembled to an outside of the insulator and a ground electrode which is joined to a front end portion of the metal shell at a proximal end portion thereof. Then, by applying a high voltage to the center electrode, an electric spark is generated in a spark gap defined between the center electrode and the ground electrode, as a result of which a compressed air-fuel mixture is ignited.
In addition, there is proposed a technique in the patent literature in which a compressed air-fuel mixture is ignited by introducing alternating current power into a spark gap.
However, the technique described in the patent literature specifies nothing about the alternating current power that is introduced into the spark gap, leading to fears that the ignitability cannot be increased.


A thin film membrane filtration system recovers particulate from the waste water stream of a wood panel fabrication process to a desired concentration of approximately 30-50% solid by weight. The high concentration level enables improved transport or disposal. Rather than discard the concentrate, however, the concentrate is added into subsequent wood panel "particle board" batches at a rate of approximately 0.5 to 0.65 gallons per 1000 pounds of wood product. The concentrate reduces press time, serves as a scavenger for tying up formaldehyde and serves as a resin extender for strengthening internal bonds of fabricated panels. The membranes capture the particulate into an accumulated concentrate, while passing permeate output to a recycle water stream.

This invention relates to water treatment methods used during wood panel fabrication processes. More particularly this invention relates to a method and apparatus for filtering and concentrating particulate out of a waste water stream. The resulting concentrate is re-applied to the fabrication process, rather than discarded as waste. The resulting wood panels exhibit less formaldehyde emission during their useful life and stronger internal bonds during testing. The cleaned waste water stream is recycled into the air pollution control system of the fabrication process to collect other particulate. Accordingly, the fabrication process produces improved wood panels with fewer waste by-products.
Wood panel fabrication involves steps of drying the wood product (i.e., furnish, wood flakes, raw material), combining and mixing constituent materials (i.e., wood product, resin, wax and scavenging agents), then pressing the materials into a panel. The output is wood panel (i.e., particle board, plywood, oriented strand board, medium density fiberboard). During the drying operation, by-products including (i) fibers, such as wood ash and wood particles, (ii) semi-solids, including fillers, and (iii) liquids are generated. Such materials are captured by an air pollution control system and collected in a recycling water stream. The liquids and semi-solids include hydrocarbons and other organic molecules. In one known process, by-product gasses are first conditioned with water sprays to achieve adiabatic saturation. As a result, the gas is cooled to the necessary level for hydrocarbon vapors to condense. The fibers, semi-solids and liquids, including hydrocarbon droplets, then are collected by a precipitator and discharged into the recycling water stream.
Removal of the hydrocarbons is especially important when drying resinous species such as Southern Yellow pine or Douglas fir. If not condensed and collected as a droplet, the vapors will condense when discharged to the atmosphere forming a blue haze plume (often characterizing wood drying emissions).
FIG. 1 shows a block diagram of a prior art emission control system 10 used in a wood panel fabrication process. Included is a wet electrostatic precipitator 11, also described in U.S. Pat. No. 4,194,888. The system 10 includes a "first" recycle water quench stage 12 and a "second" clean water flush stage 14. The recycle quench stage 12 includes a preconditioning chamber 24, settling tank 26 and pump 28. The clean water flush stage 14 includes the wet electrostatic precipitator 11, a flush tank 18, and pumps 20, 22.
The precipitator 11 employs a high-intensity ionization electrode configuration which concentrates a charging field in a zone between a disc and a collection tube. The geometry enables formation of a stable, high intensity, electrostatic field. Particle charging of 20 kv per inch is maintained with minimal sparking. An ensuing migration velocity results in a desirably high particulate collection efficiency.
Referring to FIG. 1 and the first stage 12, hot dirty gas, including hydrocarbons, and fibers from the drying wood panel are received into the pre-conditioning chamber 24 at inlet 30. Recycled water from the settling tank 26 is sprayed via pump 28 into the chamber 24 conditioning and cooling the gas stream to achieve adiabatic saturation. Spray nozzles with a large orifice diameter quench the gas stream by producing large diameter droplets. Such large droplets are unlikely to evaporate completely, thereby creating spray-dried particulate. The large nozzles also are less likely to clog. The spent quench water is drained to the settling tank 26 for treatment and recycling. The pre-conditioned gas stream, including hydrocarbon droplets is output at channel 32 into precipitator 11.
The second stage 14 receives the gas stream into a cyclone module 34 of precipitator 11. The cyclone 34 removes any large particles such as wood fibers and large water droplets. Remaining fine mist droplets are transported with the saturated gas as the gas enters precipitator 11. The gas stream passes through distribution devices to insure even flow into collection tubes 36. As the gas enters the tubes 36, the gas passes through a series of high-intensity corona charging fields located at each disk. Within the zone between the disks and the tubes, a high electrostatic charge is imposed on the particles. The droplets and mist together form a water film which flows downward along the length of the tubes 36 aided by gravity and the flow of the gas stream. As the charged particles flow farther down the tubes 36, the electrostatic field forces the charged particles toward the tube walls. Because the fine mist droplets are large relative to the submicron particulate, the droplets are the first particles collected at the tube walls. Clean gas exits the tubes 36 into a clean air plenum, and eventually passes through a fan and up a stack for discharge into the atmosphere.
Periodically clean water from flush tank 18 is sprayed via pump 20 into the precipitator 11 to clean the tubes 36. Because the tubes 36 are continuously wetted during the precipitation and ionization steps, the collection tube surfaces are easily washed by the flush stream. The resulting flush water flows down the tubes 36, is collected in a sump 38 at the bottom of the precipitator 11, then pumped via pump 22 to the settling tank 26.
Typically the solids and particulate accumulate in the settling tank 26, then are removed by surface skimmers, bottom drag chains, aeration/flotation devices, or filters. In practice, the solids removed by these devices can achieve a texture of "pudding". For example, such collected solids typically are 15% to 25% solids by weight. Due to the large percentage of liquid material captured with the solids, waste disposal is difficult. The collected waste typically is disposed of by burning in a wet burner or boiler, or by storage in a landfill. Transporting the waste and storing the waste in a landfill is difficult when the waste includes liquid (i.e., 75% to 85% by weight). Accordingly, there is a need to find clean functional uses for the by-product and to reduce the portions discarded as waste.
Another problem with conventional water treatment systems used for wood panel fabrication processes is that the hydrocarbons tend to stay in solution. Previously, the hydrocarbons have been removed from the water treatment system by disposing of the waste water at rates of several gallons per minute. Simple disposal of such water is undesirable. Further, government regulations for discharging waste water are becoming more restrictive. Accordingly, there is a need to reduce the hydrocarbons in solution within the recycling water stream and a need to achieve higher concentrations of solids, thereby reducing the volume of material and making handling of the material easier.

Method for recovering particulate and scavenging formaldehyde in a wood panel fabrication process


A system for providing different versions of a modularly structured apparatus for determining a physical process quantity, wherein at least two devices to be generated from the system are based on different measuring principles, including a number sensor units (41-48), each sensor unit being designed for detecting a determined physical measuring quantity and for converting said measuring quantity into an electrical measuring signal, wherein at least two of the sensor units are distinguished from each other by their underlying measuring principles; at least one evaluation unit (10), adapted to connect to the sensor units, for evaluating and generating a process quantity signal representing the physical process quantity from the measuring signal of a sensor unit; at least one output unit (13) for outputting the process quantity signal; at least one voltage supply unit (16); and at least one housing unit (22-24) configured to accommodate at least the evaluation unit.

An apparatus for determining a physical process quantity of a medium is usually also called a sensor. Such sensors are generally used in industrial processes for determining information about that process. Depending on the qualities of the physical process quantity, or the information to be obtained, various measuring principles are relied upon.
In the context of the present invention, the term "physical process quantity" is to be understood to mean, for example, the filling level of a medium in a vessel, the pressure of a medium in a vessel, the flow of a medium through a conduit, the temperature, the density of the moisture, or any other material constant of a medium. However, the present invention is not limited to the above explicitly mentioned process quantities, but is also applicable for devices for determining other physical process quantities.
The information obtained by means of various measuring methods essentially serves to monitor and to control (with or without feedback) a process. The filling level of a filling matter may thus be measured as follows: capacitive filling level measurement, filling level measurement based on a pressure measurement, filling level measurement using ultrasonic waves, filling level measurement using radar, filling level measurement using a guided microwave, filling level measurement by means of vibration and conductive filling level measurement (limit level measurement).
In capacitive filling level measurement the filling matter and the vessel are combined with a measuring probe to form an electrical capacitor. The filling level is detected by measuring the capacitor's capacitance.
In non-contact ultrasonic filling level measuring methods, ultrasonic pulses are generated. A piezo-ceramic ultrasonic transducer transmits periodic sound pulses that are reflected by the filling matter surface. Using the combined transmitting and receiving system, the filling level is computed from the measured delay of the sound.
When using a guided microwave, radio frequency microwave pulses or electrical pulses are guided along an electrical waveguide, such as a steel cable or rod. On impact with the filling matter surface, the impulses are reflected. The delay of the pulses is evaluated by the integrated electronics and output as the filling level. This method is often also known as the TDR method.
In radar based filling level measurement, the delay is measured between transmitting and receiving very short microwave pulses. Time is a measure of the filling level, while the filling matter surface directly acts as a reflector.
In the filling level measurement by means of vibration, a vibration sensor is made to vibrate using piezoelectricity. On contact with the filling matter, the vibration is attenuated. The measuring electronics detects when the limit level is reached.
Finally, in the conductive filling level measurement, when a filling matter contacts the measuring probe, a current circuit is closed and a switching command is initiated. The conductive measuring principle is for economically detecting limit levels in electrically conductive fluids.
Pressure based measuring techniques include, for example, the method using process pressure detection or using differential pressure detection. In the method using process pressure, the pressure in tube conduits or vessels is detected using an oilless metallic or ceramic measuring cell, and converted, for example, into a 4-20 mA current signal. According to the differential pressure principle, the differential pressure is measured preferably using ceramic or metal measuring cells, and converted preferably into a 4-20 mA current signal.
With filling level sensors in the sense of the present invention, a basic distinction may be made between continuously measuring sensors and limit level sensors. Limit level sensors do not determine the degree to which a vessel is full, but detect when a predefined filling state is reached.
Continuously measuring sensors use for example ultrasonic or microwave based, capacitive and pressure based measuring techniques. Limit level sensors use methods such a vibration and capacitive measuring techniques.
For fulfilling specific tasks and in view of the application conditions, a sensor must fulfill certain requirements and/or fulfill certain industrial standards. These standards comprise requirements with respect to the resistance of the sensors to rough industrial environment conditions and/or to the media to be measured. A further requirement is the ability to be attached and the adaptation of the sensors to the process. Moreover, requirements with respect to the electrical connection of the sensors, the output of the information obtained, and the adherence to certain safety rules of the sensors such as explosion protection rules ("Ex zone separation") must be met.
In order to adhere to these and other standards, a certain basic functional structure of each sensor is obtained that may be characterized by certain functional units. These are, among others, a sensor unit, an evaluation unit, an output unit, a voltage supply unit, an attachment unit, also called process connection, and a housing unit.
The sensor unit based on a mechanical or electromechanical principle, i.e. the sensor element contained therein, converts the physical measuring quantity into an electrical quantity while directly or indirectly contacting each medium. The electrical measuring signal thus generated, which is representative for each physical measuring quantity, is then further processed by the sensor electronics unit. The sensor electronics unit is a sensor specific circuit unit and must therefore be adapted to each sensor element. The sensor electronics unit processes the electrical measuring quantity signal in such a way that, for example, the electrical measuring signal is amplified, filtered and converted into a digital measuring signal.
The sensor electronics unit has a series connected evaluation unit deriving, with respect to the medium, the desired information from the measuring signal processed by the sensor electronics unit. The measured value thus generated is forwarded by the sensor via an output unit series connected after the evaluation unit to a process control system, for example, via a field bus or a two-wire loop. The sensor unit, the sensor electronics unit, the evaluation unit, and the output unit are often accommodated in a single housing and are supplied with voltage or current by a voltage supply unit also accommodated in the housing. The housing and/or the entire apparatus is attachable to a vessel or wall portion via an attachment unit, also called a process connection.
As already mentioned, each sensor must comply with a certain safety policy encompassing all these functional units. Therefore, a safety policy must be established for each sensor, taking into account different sensor components or their design.
Due to the multitude of different measuring quantities and to the measuring techniques for converting physical quantities into electrical information, it has been the usual practice to develop and manufacture for each measuring task a specific sensor with a unique design and functional units as well as mechanical components specially adapted to each measuring task. By this individual and sensor specific device development and manufacture, sensors may be provided that are optimally adapted to their measuring tasks and the application conditions.
A great disadvantage of such an approach is the high development cost and the great number of components and functional units that must be developed in connection with each sensor generation. This high development complexity, however, means high costs for manufacturers who do not specialize in a single sensor but offer a whole range of possibly related, but otherwise, different sensors. Also on the side of the users, the multitude of components and functional units may contribute to an increase in the cost required if, for example, the operation or the attachment of each sensor is different.
In our view, an apparatus for determining a physical process quantity should be known from U.S. Pat. No. 6,295,874 B1 and the associated WO 01/18502 A1, in which the process quantity is determined using a delay method. The apparatus shown herein may comprise an evaluation unit which is to be essentially independent of the sensor used. In our view, however, said document teaches the use of a sensor operating on the delay principle. Moreover, a communication unit independent of each sensor is used for data exchange with a remote process control. It must be recognized, however, that the communication unit is intended to be combined with a sensor based on the principle of delay measurement.
A prospectus of the German firm Krohne/Deutschland does show a modular structure of a filling level radar sensor, wherein various sensor units of a filling level radar sensor, such as horn antenna, wave guide or wave stick are combined, using a spacer, with two different sensor housings containing the respective electronics. Again, according to the technical understanding of the inventors, only a certain variability in the manufacture of a filling level radar sensor is taught.
Finally, the integration of absolutely oilless measuring cells in a modular system of process connections, housings, signal transmission methods, matching approaches, combined with the convenience of use provided by an intelligent system of operation are known from an offprint entitled "Lego für Erwachsene" ("Lego for grownups") by Rolf Hauser, in the journal Messtechnik, Steuem, Regeln, Automatisieren, Messen, August 1999. In it various pressure sensors are presented that can be combined with different housings. Again, modularity seems to be limited to one measuring principle only.
Finally, in order to provide a better explanation and understanding of the present invention, a definition of terms used in the present specification is given. The present definitions will provide at least a rough idea for interpreting the units and components of a sensor described. For interpreting the terms, however, the technical knowledge and the insight of a person skilled in the art in the field on which the present invention is based may also be necessary.
Sensor:
An entire apparatus for determining a physical process quantity of a medium. A sensor may be, for example, an apparatus ready for attachment or operational for determining a physical process quantity of a medium.
Sensor Element:
An element directly or indirectly contacting the medium to be measured in order to sense the desired physical process quantity. This may be an electromechanical element comprising, for example, one or more assemblies or components for converting a physical process quantity into an electrical signal. The conversion may also conceivably be carried out under the influence of an electrical excitation. Sensor elements include various antennas (horn antenna, rod antenna, patch antenna and the like), cable or rod probes for TDR, tuning forks with piezo drive, pressure measuring cells, differential pressure measuring cells, cable or rod probes for capacitive measurement and ultrasonic transducers.
Sensor Electronics Unit:
An electronic assembly, such as a circuit with electronic components, possibly including associated software for processing the electric signal from the sensor element and deriving a measured value that characterizes the process quantity.
Examples for a sensor electronics unit and its components for each measuring technique are listed below:
a. Radar: transmitting pulse generator, sensing pulse generator, frequency control for clock oscillators, sampling receiver, amplifier, filter, logarithmic amplifier, A/D converter, ECHOFOX software implemented on micro-controller system,
b. Ultrasonic: transmitter, receiver (amplifier, filter), logarithmic amplifier, A/D converter, ECHOFOX software implemented on micro-controller system,
c. TDR: transmitting pulse generator, sensing pulse generator, frequency control for clock oscillators, sampling receiver, amplifier, filter, A/D converter, ECHOFOX software implemented on micro-controller system,
d. Vibration: oscillator, amplifier, filter, frequency or amplitude discriminator, A/D converter,
e. Process pressure, differential pressure: capacitance/voltage converter, A/D converter,
f. capacitive sensor: capacitance/voltage converter, A/D converter.
Sensor Unit:
A unit or assembly comprising a sensor element and a sensor electronics unit.
Evaluation Unit:
An electronics assembly, such as a circuit with electronic components and associated software for processing the measured value characterizing the process quantity to obtain an output value representing the same process quantity or a physical process quantity derived from it. An evaluation unit can carry out, for example, empty/full adjustments, linearization, scaling, sensor diagnosis and generating error messages. All above-mentioned activities of an evaluation unit can be implemented as software elements on a micro-controller system.
Output Unit:
An electronics assembly such as a circuit with electronic components and associated software for outputting at least the output value as well as other existing information (e.g. on the functional status of the sensor itself). The output unit can be expanded to provide an input and output unit, additionally enabling the input of, for example, adjustment values and parameters for functional optimization of the sensor. In this case, this could also be called a communication unit, comprising, for example, a digital communication, preferably within a bus system, between the sensor and the periphery. An output unit can include a current output of between 4 and 20 mA, a relay, an IIC interface, various modems (HART, PA, FF etc.). Corresponding communication protocols (HART, PA, FF etc.) can be implemented on a micro-processor system.
Voltage Supply Unit:
An electronic assembly such as a circuit with electronic components and associated software for converting the electrical energy supplied from the outside into energy of suitable electrical voltage sources for supplying the remaining electronic units of the sensor.
Display Unit:
An electronic assembly of the sensor for displaying the output value and perhaps further data such as indications on the operational status of the sensor etc.
Operation Unit:
An electronic assembly of the sensor for inputting at least one value such as an adjustment value.
Display and Operation Unit:
A generic term for a unit comprising at least one display unit or operation unit. In one exemplary embodiment, this unit comprises both a display unit and an operation unit in a common assembly.
Physical Process Quantity:
A physical characteristic of the process which is to be determined and output by the sensor (example: pressure, filling level, temperature, flow).
Physical Measuring Quantity:
A physical quantity of the process that is directly measured. It can either be identical to the physical process quantity or may allow the physical process quantity to be derived from it. For example, in hydrostatic filling level measurement the pressure is the physical measuring quantity.
Electrical Measuring Quantity:
An electrically measurable quantity of the sensor element e.g. the capacitance value provided by a capacitive pressure measuring cell when a pressure is applied to it.
Measuring Principle:
Characterized by the physical measuring quantity. In summary, the following measuring principles may be distinguished for the purposes of the present invention: a) delay measurement of freely radiated or guided waves reflected on a filling matter, such as electromagnetic waves or ultrasonic waves, b) measurement of a capacitance of a filling matter, c) measurement of a pressure or differential pressure, d) limit level measurement by means of vibration or in a conductive way, e) temperature measurement.
Measuring Technique (Sensorics)
Characterized by the electrical measuring quantity or the manner in which the electrical measuring quantity is obtained and evaluated. A further feature of the measuring technique is the functional operation of the sensor element.
In the following, exemplary embodiments of sensors and their different characteristic quantities explained above have been listed in the table below.
physical processphysical measuringelectrical measuringmeasuringmeasuringSensorquantityquantityquantityprincipletechniqueradar fillingfilling levelreflector-delay ofdistancemeasurementlevel sensor(continuous)sensormicrowavesmeasurementof the delay ofdistanceradiated microwavesultrasonicfilling levelreflector-delay ofdistancemeasurement of thefilling level(continuous)sensorultrasonicmeasurementdelay of radiatedsensordistancewavesultrasonic waveshydrostaticfilling levelpressure of acapacitance of apressurecapacitancepressure(continuous)liquid columncapacitive pressuremeasurementmeasurement insensormeasuring cella measuring cellcapacitivefilling levelelectricalelectricalcapacitancecapacitancesensor(continuous orcapacitancecapacitancemeasurementmeasurementlimit level)between probebetween probeusing a probeand vesseland vesselvibrationfilling leveleffect of thedampening orvibrationmeasurement ofsensor(limit level)filling matterfrequency offsetmeasurementdampening oron mechanicalof a mechanicalof a mechanicalfrequency offsetvibratorsvibratorvibratorof a vibration

System for manufacturing a modularly structured apparatus for determining filling level


A method for testing a semiconductor substrate forming a liquid crystal display device, which method enables a potential change corresponding to a defective condition of pixel cell driving circuits to be detected accurately even when a ratio of pixel capacitance to wiring capacitance is lowered with decrease in size or increase in definition of the liquid crystal display device. The method includes: a charge retaining step for making pixel capacitances connected to a plurality of pixel switches selected from all pixel switches connected to one data line retain charge; and a detecting step for simultaneously detecting the charge retained in a plurality of the pixel capacitances in the charge retaining step from the one data line.

Liquid crystal display devices using an active matrix system are widely used in for example liquid crystal projector apparatus, liquid crystal display apparatus and the like. FIG. 6 shows an example of circuit configuration of such a liquid crystal display device 100 using the active matrix system. As is well known, a liquid crystal display device using the active matrix system has pixel cell driving circuits each having a pixel switch and a pixel capacitance connected to the pixel switch, for example, which circuits are formed so as to be arranged in a form of a matrix on a semiconductor substrate. The liquid crystal display device also has a structure in which a counter substrate having a common electrode formed thereon is opposed to the semiconductor substrate and a liquid crystal is sealed in between the semiconductor substrate and the counter substrate.
As shown as a pixel cell driving circuit 10 in a part enclosed by a broken line in FIG. 6, for example, each of the pixel cell driving circuits formed on the semiconductor substrate has a pixel switch S11, a pixel capacitance C11, and a pixel electrode P11. In this case, an N-channel type FET (Field Effect Transistor) is used as the pixel switch. The pixel switch S11 has a source connected to a common electrode (or a ground) via the pixel capacitance C11. A node of the source of the pixel switch S11 and the pixel capacitance C11 is connected. with a pixel electrode P11. Incidentally, a "pixel cell" in the liquid crystal display device refers to a display region in a liquid crystal layer corresponding to each such pixel electrode. The pixel switch S11 has a gate connected with a gate line G1 extended from a vertical scanning circuit 2, and has a drain connected with a data line D1 extended from a horizontal scanning circuit 3. One pixel cell driving circuit is thus formed, and the pixel cell driving circuits are arranged in the form of the matrix on the semiconductor substrate as shown in FIG. 6.
The vertical scanning circuit 2 and the horizontal scanning circuit 3 each including a shift register, for example, are also formed on the semiconductor substrate. The vertical scanning circuit 2 sequentially scans gate lines G1, G2, . . . Gv extended in a horizontal direction. The horizontal scanning circuit 3 sequentially scans data lines D1, D2, D3 to Dh extended in a vertical direction.
The counter substrate having the common electrode supplied with a common potential Vcom is disposed so as to be opposed to the thus formed semiconductor substrate. The liquid crystal is sealed in between the semiconductor substrate 100 and the counter substrate disposed in such opposed positional relation to each other, whereby a liquid crystal layer 5 is formed. The liquid crystal display device 100 as a whole has such a structure.
FIGS. 7(a) to 7(j) are timing charts illustrating timing of driving pixel cells in the liquid crystal display device 100 with the above-described structure. The vertical scanning circuit 2 shifts an output thereof by one line by the shift register. Thereby the vertical scanning circuit 2 scans the gate lines in a vertical direction in order of the gate lines G1→G2→G3→ . . . on a line-sequential basis, as shown in FIGS. 7(a), 7(b), and 7(c). As shown in the figures, a power supply voltage VDD is applied to a gate line in a scanning period. In this period, a pixel switch connected to the gate line is in an on state. While scanning is not performed, the gate line is set to a ground potential VSS, and thus the pixel switch is in an off state.
FIG. 7(d) shows in enlarged dimension a section A in which scanning of the gate line G1 as shown in FIG. 7(a) is started. When the scanning of the gate line G1 is started as shown in FIG. 7(d), the pixel switches S11 to S1h arranged in a row connected to the gate line G1 are all brought into the on state. Within the period when the gate line G1 is scanned, the horizontal scanning circuit 3 applies voltages V1, V2, V3, . . . corresponding to data to the data lines in order of the data lines D1→D2→D3→ . . . in a horizontal direction as shown in FIGS. 7(e) to 7(g). That is, the horizontal scanning circuit 3 performs scanning in the horizontal direction. The horizontal scanning circuit 3 sequentially shifts the data lines to which to apply an output thereof by the shift register, whereby the above operation is obtained.
First, when the data line D1 is scanned as shown in FIG. 7(e), a charge corresponding to a level of the voltage V1 is stored via the pixel switch S11 which is in the on state at this time. That is, data is written to one pixel. Thereby a potential corresponding to the charge stored occurs at the pixel capacitance C11. The potential is shown as a potential V1 corresponding to a voltage value V1.
The potential V1 also appears at the pixel electrode P11. In response to a potential difference between the potential V1 of the pixel electrode P11 and the common potential Vcom of the common electrode opposed thereto, the liquid crystal of the liquid crystal layer 5 corresponding to a position of the pixel electrode P11 is excited. That is, the pixel cell is driven. As is understood from timing of scanning the data line D1 in FIG. 7(e) and charge storing timing in FIG. 7(h), the charge stored in the pixel capacitance, that is, the data continues to be retained even after the scanning of one data line (data writing) is ended to shift to scanning of the next data line, and thus continues to excite the liquid crystal (pixel cell).
After the data line D1 is thus scanned, the data line D2 is scanned, as shown in FIG. 7(f). Similarly, data is written to a pixel capacitance C12 via a pixel switch S12, as shown in FIG. 7(i). Thereafter the next data line D3 is scanned as shown in FIG. 7(g), and as shown in FIG. 7(j), data is written to a pixel capacitance C12 via a pixel switch S12.
When the scanning in the horizontal direction of one row is completed and with this the scanning of the gate line G1 is also completed, scanning of the next gate line G2 is then started, as shown in FIG. 7(b). As described with reference to FIGS. 7(e) to 7(j), also within a period when the gate line G2 is scanned, scanning in the horizontal direction is performed, that is, data is written to pixel cells in a horizontal line corresponding to the gate line G2. Thereafter, in a state in which the next gate line G3 is scanned as shown in FIG. 7(c), data is written to pixel cells in a horizontal line corresponding to the gate line G3 in timing shown in FIGS. 7(e) to 7(j). Thereafter the remaining gate lines are sequentially scanned, and within a period of scanning of each gate line, data is similarly written to pixel cells in a horizontal line corresponding to the gate line. Thus the vertical scanning circuit 2 and the horizontal scanning circuit 3 in the liquid crystal display device using the active matrix system sequentially drive the pixel cells by scanning the gate lines so as to drive the gate lines sequentially and scanning the data lines so as to drive the data lines sequentially to write data within a period of scanning one gate line.
The semiconductor substrate forming the liquid crystal display device of the above configuration may have a failure or a defect formed in the circuits in its fabrication process. That is, the semiconductor substrate has a possibility that a pixel cell driving circuit not operating properly may exist because of a short circuit in the pixel switch or the pixel capacitance, a disconnection or a short circuit in the gate line or the data line, or the like. Thus the circuits on the semiconductor substrate are tested for defects in a process of fabricating the liquid crystal display device.
Such testing of the circuits on the semiconductor substrate for defects is performed as follows, for example. First the data lines extended from the semiconductor substrate to be tested and a testing device are connected to each other. On the semiconductor substrate, the vertical scanning circuit 2 and the horizontal scanning circuit 3 perform driving in timing similar to that at the time of display. Specifically, the vertical scanning circuit 2 and the horizontal scanning circuit 3 drive the pixel cells in the same manner as described with reference to FIGS. 7(a) to 7(j), for example. In this case, a data line connected to a pixel cell driving circuit to which data is written should have a potential at a level corresponding to the written data when the pixel cell driving circuit operates properly. When there is some defect, the potential level should be other than a normal value. Accordingly, the potential level is detected by the testing device, that is, charge of the pixel capacitance is read from the data line, whereby the pixel cell driving circuit can be tested for defects.
However, in consideration for use in for example projector apparatus and the like, the liquid crystal display device has recently been required to have reduced size and a larger number of pixels per unit area for improvement of resolution. In this case, when the size of the liquid crystal display device as a whole is to be reduced to ½ without changing the number of pixels, or when the resolution is to be doubled without changing the size of the device, for example, in both cases the longitudinal/lateral dimension of a pixel cell needs to be reduced to about ½. Assuming that the pixel cell has a square shape, when the longitudinal/lateral dimension of the pixel cell is to be reduced to ½, the pixel capacitance will be reduced to ¼.
For fabrication reasons, there is a limit to reduction in size of a pixel switch within a pixel cell driving circuit. Thus, when the size of the pixel switch is reduced to substantially a limit and the pixel cell needs to be further reduced in size, the pixel capacitance has to be reduced in size. Hence, when the pixel cell driving circuit is to be reduced to ½ the size thereof, for example, and when the size of the pixel switch is already considerably small, the size of the pixel capacitance needs to be reduced more to less than ¼, because a ratio of reduction in the size of the pixel capacitance is increased.
Considering capacitance of the data line, assuming that width in the lateral direction of the data line is not changed when the longitudinal/lateral dimension of the liquid crystal display device is to be reduced to ½, for example, only length in the longitudinal direction of the data line is reduced to ½, and the size of the data line as its area is reduced to ½. That is, the capacitance of the data line needs to be reduced by only ½. Thus, an imbalance in capacitance reduction rate occurs in that the pixel capacitance is reduced to ¼, whereas the capacitance of the data line is reduced only to ½.
Further, when the resolution is to be doubled without changing the size of the liquid crystal display device, the number of pixel switches connected to the data line is doubled even though the length of the data line is not changed. When the pixel switches cannot be reduced any further, the capacitance of the data line is increased by an amount corresponding to drain capacitance of the added pixel switches. Thus, as reduction in size of the pixel cell is furthered, a ratio of the data line capacitance to the pixel capacitance is increased, and so-called wiring capacitance becomes dominant. In such a case, when a charge of the pixel capacitance is to be read from the data line, a potential change in the data line may be so small as to be difficult to detect. Since the testing of the semiconductor substrate by the above-described method involves reading the charge of the pixel capacitance from the data line, it is difficult to conduct the test properly when the ratio of the wiring capacitance to the pixel capacitance is increased as described above.
Thus, in the present situation, it is required to actually display an image on a finished product as a liquid crystal display device after the filling of a liquid crystal, and then visually check the image, for example, to thereby test for pixel defects. When the test is thus conducted in a stage where the liquid crystal display device is completed, if a defect is found, for example, it is necessary to disassemble the liquid crystal display device and make repairs or discard the liquid crystal display device. That is, it is desirable from a viewpoint of fabrication efficiency and fabrication cost that the circuits formed on the semiconductor substrate be able to be tested in a stage where a wafer as the semiconductor circuit substrate is formed, for example, before being incorporated as the liquid crystal display device.
It is accordingly an object of the present invention to provide a semiconductor substrate testing method that properly detects a failure in pixel cell driving circuits before being completed as a semiconductor device even when the ratio of the wiring capacitance to the pixel capacitance is increased with decrease in size or increase in definition of the semiconductor device having the pixel cell driving circuits, a semiconductor device including a semiconductor substrate enabling the testing method, and a display apparatus having such a semiconductor device.

Testing method, semiconductor device, and display apparatus


An infant seat which functions as an infant carrier, a glider, or a car seat. The car seat includes a base with an upwardly open cavity and a carrier connected to the base and at least partially contained within the cavity. The positioning of the carrier relative to the base may be adjusted to allow the carrier to move relative to the base or to lock the carrier to the base. In a locked configuration, seat belt receivers are properly positioned to receive an automobile seat belt, when the car seat is positioned on the seat of an automobile.

There are a wide variety of infant seats available on the market today. Notwithstanding this wide variety, all of such infant seats can generally be categorized as either a single function, i.e., one primary intended use, or a multi-functional, i.e., more than one primary intended use, infant seat. Such infant seats can be further categorized based upon the types of functions offered by the particular infant seat.
One type of single function infant seat are those which are primarily designed for use as an automobile safety seat (hereinafter referred to as a "car seat"). A representative sample of this subcategory includes U.S. Pat. No. 4,580,842 to Segal, issued Apr. 8, 1986; U.S. Pat. No. 4,655,506 to Wise et al., issued Apr. 7, 1987; and U.S. Pat. No. 4,770,468 to Shubin, issued Sep. 13, 1988. Each of these references utilize various restraint systems which include some type of harness and frontal barrier to provide an infant seat which will adequately protect its occupant when a passenger of a motor vehicle.
A second type of single function infant seat can be characterized as those being designed for use as a rocker or glider to subject the infant to a soothing motion. This particular subcategory of single function infant seats appears to have evolved from larger types of infant furniture such as cribs, cradles, and bassinets which are primarily designed to contain the infant in a prone position. For instance, cradles have long been used to rock an infant to sleep, the motion being supplied by either the infant's own movements or by the application of a force to the cradle by an individual attending to the infant. However, many of such devices have also incorporated some type of drive mechanism, such as an electric motor or other similar device, to provide the desired motion. A representative sample of these types of "motorized cribs" are U.S. Pat. No. 2,979,735 to Helmer, issued Apr. 18, 1961; U.S. Pat. No. 3,125,767 to Griggs et al., issued Mar. 24, 1964; U.S. Pat. No. 3,648,307 to Meade, issued Mar. 14, 1972; U.S. Pat. No. 4,028,753 to Rios, issued Jun. 14, 1977; and U.S. Pat. No. 4,620,334 to Robinson, issued Nov. 4, 1986. Although each of these references applies some type of motion to a crib or other similar structure, some are merely a driven support surface upon which a "crib" may be positioned, while others provide an assembly where the "crib" and the drive assembly are integrally interconnected.
Possibly due to the popularity of "motorized cribs," while recognizing the somewhat bulky nature of such articles, motorized infant seat rockers were devised. For instance, U.S. Pat. No. 3,653,080 to Hafele, issued Apr. 4, 1972 and U.S. Pat. No. 3,851,343 to Kinslow, Jr., issued Dec. 3, 1974, disclose one type of infant seat rocker. Generally, both Hafele and Kinslow, Jr. disclose the use of a drive mechanism connected to an infant seat by linkages or a frame assembly to, in part, support the infant seat in a reclined position with the seat portion being nearest a supporting surface such as a floor. When the drive mechanisms of Hafele and Kinslow, Jr. are activated, the linkages cause the infant seat to essentially pivot about its lower portion to generate a rocking-type motion. Although such designs generate one type of motion which may be desirable, some of the linkages or other similar connectors are exposed during operation which presents a safety problem if other infants or persons are in the area. The infant seats used with the driver assembly of both Hafele and Kinslow, Jr. appear to only be usable for this limited function as a rocker.
A second type of infant seat rocker is disclosed in U.S. Pat. No. 4,656,680 to Wilson, issued Apr. 14, 1987. The apparatus of Wilson generally includes a base, a carrier support pivotally attached to one end of the base, an infant carrier which is preferably detachable from the carrier support, and a drive mechanism which is attached to the base on the end opposite of the pivotal connection and located between the carrier support and the base. The drive mechanism includes a cam which contacts the underside of the end of the carrier support opposite its pivotal connection to the base. Rotation of the cam by the drive mechanism thereby causes the carrier support, and thus the attached infant carrier, to pivot through a limited range of motion. Although Wilson includes an infant carrier and essentially a detachable base, the base is a cumbersome structure which incorporates a drive assembly and apparently requires a large supporting surface to maintain its stability.
Another variation of an infant seat rocker is disclosed in U.S. Pat. No. 4,911,499 to Meeker, issued Mar. 27, 1990. Meeker discloses a base having an upwardly facing opening defined by the side walls and its end walls, a platform positioned within this opening and pivotally connected to the side walls of the base by generally U-shaped links, and a drive mechanism to move the support relative to the base. The platform is shaped to receive any number of commercially available infant seats, which is allegedly an advantage over some existing rockers which require an infant seat of special construction for use with the rocker mechanism. When an appropriate infant seat is positioned on the platform and a rocking motion is desired, the motor is activated which causes the platform, and thus the attached infant seat, to rock through a limited range of motion by essentially swinging on the U-shaped links. A locking mechanism is also provided which prohibits motion of the platform relative to the base to allow a child to be positioned within an infant seat already on the platform or to allow the rocker to be used as a stationary device. Meeker does not suggest that the entire assembly, i.e., the base, intermediate platform, and infant seat, would be appropriate for use as a car seat.
Although single function infant seats remain a popular choice among consumers, many manufacturers are now offering multi-functional infant seats. The promotion of multi-functional infant seats has centered upon having one article which performs numerous functions to potentially reduce the physical space occupied by such infant accessories and possibly the cost since now one physical unit performs the functions of two physical units. Consequently, a wide variety of combinations of functions are now being offered.
For instance, the Snugli.RTM. Bouncer Infant Carrier, commercially available from Gerry Baby Products Company, is essentially a combination infant carrier and bouncer. In providing these two functions, the structure of the Bouncer Infant Carrier includes a base and a carrier movably connected to the base. Two spring rods establish this movable connection, each having a first portion fixedly attached to the base, a second portion upwardly inclined relative to the base and slidably engaged with the carrier, and a third portion pivotally attached to an adjusting assembly which is in turn rotatably attached to each side wall of the carrier. The pivotal connection is made at a point radially outward from the rotational axis of the adjusting assembly. Rotation of both adjusting assemblies results in the carrier sliding up the inclined portions of the spring rods to increase the distance between the carrier and the base. Due to the inherent flexibility of the spring rods when the carrier is in this position, movements of an infant in the carrier or the application of a force by an individual attending to the infant will produce a bouncing-type motion in substantially a vertical direction. Rotation of the adjusting assemblies in the opposite direction will cause the carrier to slide back down the inclined portions of the spring rods into engagement with the base where the movement of the carrier relative to the base is substantially restricted. In this position, the assembly may be transported by use of handles rotatably attached to the carrier. Although disclosing a combination infant carrier and bouncer, there is no suggestion that the Bouncer Infant Carrier would be appropriate for use as a car seat.
U.S. Pat. No. 4,634,177 to Meeker, issued Jan. 6, 1987, discloses essentially a combination infant carrier and car seat. In order to provide both of these functions, Meeker includes an infant carrier which is detachably connected to a base structure which in turn is detachably connected to the seat of an automobile by its restraint mechanism, i.e., a seat belt. The infant carrier includes a harness to restrain the infant and also a handle for transporting the infant carrier when the carrier is detached from the base. Consequently, the infant carrier may be connected to the base to function as a car seat or it may be detached from the base and transported by the handle to function as an infant carrier. Although disclosing an infant seat and base which function as both an infant carrier and car seat, Meeker does not suggest that the combination could also somehow be used as a rocker. To the contrary, much of the disclosure is directed to the detachable connection between the carrier and base which maintains the carrier and base in a locked position.
U.S. Pat. No. 4,598,946 to Cone, issued Jul. 8, 1986, discloses essentially a combination car seat and rocker. The infant seat is fixedly connected to a planar base by a nut and bolt combination. The material structure of the seat and base, however, is such that it possesses sufficient flexibility to allow the seat to rock about the axis of its cylindrical bottom relative to the base. The infant seat includes open ended slots for receiving a seat belt if positioned in a car and the base has handholds for transporting the assembled unit.
U.S. Pat. No. 4,688,850 to Brownlie et al., issued Aug. 25, 1987, discloses a combination rocker, car seat, carrier, and swing seat. The seat includes a harness and slots for receiving a typical automobile restraint mechanism so that the seat may function as a car seat. The seat also includes a rotatably adjustable handle so that the seat may be easily transported when used as an infant carrier. Furthermore, the seat also includes an adjustable L-shaped linkage connected to the back and bottom portion of the seat to allow the seat to function as a rocker or a stationary seat. When the linkage is placed in a first position, the seat is able to rock since the lowermost section of the linkage is slightly upwardly inclined from where it connects to the seat bottom. When the linkage is placed in a second position, the lowermost section of the linkage is substantially parallel with the seat bottom to substantially restrict any motion of the carrier relative to the supporting surface. Consequently, the linkage is an extension of the infant seat which allows the seat to rock or remain stationary, depending upon its position.
U.S. Pat. No. 4,371,286 to Johnson, Jr., issued Feb. 1, 1983, essentially discloses a combination infant carrier and rocker. The carrier includes a rotatable handle for easy transportation. The contour of the seat bottom is curved to allow the carrier to rock when placed on a supporting surface upon experiencing a suitable driving force. However, the handle may be rotated to extend outwardly from the back of the carrier and towards the supporting surface to restrict or limit the motion of the carrier relative to the supporting surface. Although disclosing a combination infant carrier and rocker, there is no disclosure which suggests that the unit would be suitable as a car seat. Moreover, since no base unit is used, a potential safety hazard is introduced since the rocking motion may tend to pinch a misplaced finger or other body part between the rocker and the supporting surface.

Multi-function infant car seat including glider assembly