The present invention relates to the concept of a tripod having three separate legs which can placed on a surface such as the ground and which come together at a joint location at the top portion of the legs to retain a support member to which a piece of photographic equipment such as a camera can be attached. The present invention relates specifically to the field of photography tripod support equipment which contains tripod legs wherein each leg of the tripod is composed of a multiplicity of sections which can be folded up and retained in the folded condition for transport and thereafter, can be converted to legs which are immediately in the in-use condition after the mechanism which retains the legs in the folded condition is released to permit the three tripod legs to be quickly unfolded and automatically placed into the in-use condition.

1. Field of the Invention
The present invention relates to the field of tripods which are used to support photographic equipment. In particular, the present invention relates to the field of tripods wherein the legs of the tripod can be folded into a multiplicity of sections to facilitate transport and thereafter have the legs converted to an opened condition for use to support a camera or other photographic equipment at a given location.
2. Description of the Prior Art
In general, the subject of photographic equipment tripod legs and related tripod leg support systems which can be folded for easy transport and then converted to an assembled condition for use at a location are known in the prior art. The following 7 patents are relevant to the field of the present invention:
1. U.S. Pat. No. 3,886,700 issued to William M. Lambert on Jun. 3, 1975 for "Collapsible Structural Member" (hereafter the "Lambert patent");
2. U.S. Pat. No. 4,712,756 issued to Eugene A. Kester et al. on Dec. 15, 1987 for "Shock Corded Tripod Stand" (hereafter the "Kester patent");
3. U.S. Pat. No. 4,934,638 issued to Kevin R. Davis on Jun. 19, 1990 for "Collapsible Tripod Stool" (hereafter the "Davis patent");
4. U.S. Pat. No. 5,337,996 issued to Milton Kalish on Aug. 16, 1994 for "Portable Easel System" (hereafter the "Kalish patent");
5. U.S. Pat. No. 5,713,553 issued to Martin F. Cooper on Feb. 3, 1998 for "Portable Stand" (hereafter the "Cooper patent");
6. U.S. Pat. No. 6,202,974 issued to Michael Rellinger on Mar. 20, 2001 for "Portable Easel With Adjustable Board Support" (hereafter the "Rellinger patent");
7. U.S. Pat. No. 6,282,084 issued to Daniel Richard Goerdt et al. on Aug. 28, 2001 for "Transportable Support Apparatus For Portable Computers").
The Lambert patent discloses the concept of having a multiplicity of interconnected members which are connected by a flexible strand which in this case is described in Column 2 Line 39 and 40 as "a wire rope of a particular length". Specifically, the patent discloses:                "A collapsible structural member comprises a plurality of elongated inner elements in spaced end-to-end relationship and attached together by a flexible strand, and a plurality of elongated open-ended outer elements coaxial with the inner elements and positioned in alternating relationship therewith. The outer elements are longer than the distance between adjacent pairs of inner elements and are slidable with respect thereto between extended positions engaging the ends of an adjacent pair of inner elements whereby a substantially rigid member is created, and retracted positions engaging only one inner element, whereby the structural member can be collapsed and folded. Limiting stops are provided in the interior of the outer elements, and means for locking the outer elements in the extended position is provided."
The Kester patent discloses a photographic light stand which embodies the concept of having a tripod grouping of legs which can have at least two components which are held together by a shock cord which is comparable to a bungee cord so that when in the open condition they can immediately open. The device is also used to hold photographic lights.
The Kalish patent discloses a portable easel system which includes the concept of having a multiplicity of leg sections which are retained together and then can open and expand to a full leg with an internal elastic cord. Referring to Column 4 Line 51 through Line 60 the patent states:                "Returning now to FIG. 2, shock cord 43 resiliently connects the three segments of the right leg. Shock cord is a cord composed of a plurality of resilient strands, encased in a protective smooth sheath that allows the cord to slide easily. The shock cord then transverses adjustable cord lock 47. Stop knot 49 at the shock cord upper end keeps cord lock 47 from slipping off the end; this applies to every stop knot contiguous with a cord lock in this patent application."
The Cooper patent discloses:                "In a combination stand and rack releasably secured atop the stand, the stand is convertible between an extended use position and a collapsed storage position. The rack includes a hollow spine for storage of the stand in the collapsed storage position. The stand comprises a main telescopic post and a plurality of support legs all of which are secured to a common housing. The main post extends upwardly from the housing and the legs are attached to the housing by connectors which are bendable through an angle of more than 90° such that the legs fold upwardly beside the main post in the storage position and unfold downwardly from the housing to the use position."
The Redllinger patent discloses a portable easel with an adjustable board support.
The patent discloses:
                "A portable easel with adjustable board support which has a plurality of legs pivotally joined together by a head, the legs of which may be selectively spread apart when set up as an easel and folded together when collapsed, each leg composed of multiple interlocked sections biased together when in extended position but which may be manipulated for separation and folding into a bundle one section against another section for storage and transport, and a board support mounted on at least one leg which may be selectively adjustably moved to a desired position on any of the sections and moved against the leg on which it is mounted for storage and transport and extended away from the leg for holding a display on the easel when set up."
The Goerdt patent discloses a transportable support apparatus for portable computers.
The patent discloses:
                "A support apparatus for a portable computer, comprising:        (a) a plurality of legs; and        (b) a pedestal configured to support a portable computer, the pedestal further configured to removably couple with the plurality of legs to arrange the legs in an operative position to support the pedestal on a supporting surface, the pedestal including at least one storage compartment configured to store at least one of the plurality of legs in a storage position."
The Davis patent discloses a collapsible tripod stool. Specifically, this patent discloses:                "A collapsible tripod stool for bodily and tangible item support is described. The triangularly shaped seat is supported by a plurality of tubular legs, which may be fused, glued, or otherwise connected to the corners of the seat. In one embodiment, telescoping legs are comprised of upper, central, and lower sections, the central leg section having two different diameters to prevent section contact, and being case as one piece to eliminate welded surfaces. The central leg sections are attached to a triangularly-shaped central pivot joint by threaded members to prevent mobilization of the legs with respect to one another. The telescoping legs are angled to maximize ground surface contact and further stabilize the tripod stool of the present invention. In another embodiment, tubular legs are comprised of upper and lower sections which connect to one another and are coupled together by an elastic cord within each leg. The leg sections are conveniently detached at their approximate midpoints and folded together in a compact bundle. A pivot join comprises fabric straps secured to each leg and centrally joined to one another."
In prior art tripods, the sections of each leg telescope into an adjacent leg with the lowermost section telescoping into the next section and the next section telescoping into a third section etc. until all the legs telescope into the uppermost section. There is a connection which fastens one section relative to another when the legs are moved from the telescoped position to the open position. However, to open and fasten each leg section to another so that the three legs can remain straight involves a lot of time consuming effort. In many cases, there is a requirement for a photographer to instantly have the tripod converted from the folded condition or telescoped condition to the in-use condition so that a shot which may only be available for a few seconds can be made with a camera. Accordingly, the time that it takes to transform a conventional tripod from the closed condition to the open condition is unacceptable where it is necessary to have a quick creation of a fully assembled tripod so that a camera can be used within a matter of seconds to take the appropriate shot. A significant disadvantage of the prior art is that the leg sections are interconnected to each other in a manner which requires each section to be affixed to an adjacent section by means such as a threaded collar which threads from one section to another or a connecting member. Either way, the assembling of the telescope is a time consuming process which is unacceptable for a photographer who needs to be able to have the telescope assembled within seconds so that a photograph can be quickly taken. Therefore, there is a significant need to improve this major deficiency in prior art tripods.
Although the prior art does disclose the general concept of having tripod legs which can be converted from a folded condition to an in-use condition, there is still a significant need for a device that enables the conversion of the tripod legs to the folded condition to the in-use condition to be achieved within a matter of seconds for quick and ready use at a remote location so that a piece of photographic equipment can be quickly mounted to the tripod and placed into the in-use condition.

Tripod to support photographic equipment with tripod legs that quickly convert from a folded condition to an assembled condition


In a discharge tube of the present invention, a filler gas is composed of a mixture of inert gas and hydrogen gas and an airtight cylinder 10 in which the filler gas is enclosed in an airtight manner is provided. A pair of first and second discharge electrodes 22 and 24 are opposed to each other within an internal space of the airtight cylinder, so that an electric discharge is generated between discharging surfaces of the first and second discharge electrodes. In the discharge tube, a concentration of the hydrogen gas in the filler gas is set in a range from 20 percent by volume to 80 percent by volume.

1. Field of the Invention
The present invention generally relates to a discharge tube, and more particularly to a discharge tube in which an upper discharge electrode and a lower discharge electrode are opposed to each other in an airtight cylinder, and an electric discharge is repeatedly generated between the discharging surfaces of the upper and lower discharge electrodes.
2. Description of the Related Art
For example, a HID (high intensity discharge) headlamp for automotive vehicle requires an ignitor circuit which generates a high-voltage trigger in order to turn on the light. The ignitor circuit is mainly comprised of a capacitor which charges the electricity, a transformer which generates the high-voltage trigger, and a switching discharge tube which generates a stable voltage pulse. In the following description, this switching discharge tube will be called the discharge tube.
As disclosed in Japanese Laid-Open Patent Application No. 10-335042, the above-mentioned discharge tube is comprised of an airtight cylinder made of an insulating material, such as ceramics, and first and second discharge electrodes arranged to the end openings of the airtight cylinder. A discharging gap is formed between the first discharge electrode and the second discharge electrode within the airtight cylinder, and the filler gas is enclosed in the airtight cylinder in an airtight manner.
In the above-mentioned discharge tube, an electric discharge is generated at the discharging gap of the airtight cylinder with the presence of the filler gas therein. Conventionally, the filler gas used is a mixture of argon (Ar) gas as the major component and hydrogen (H2) gas in a volume concentration above 0.5% and below 20%.
The development of the conventional discharge tube has been carried out with emphasis given on the generation of a stable voltage pulse. However, with the recent demand of high-density assembly of the ignitor circuit in the automotive HID headlamp, it becomes necessary to increase the output voltage of the secondary coil of the transformer in addition to the generation of a stable voltage pulse by the discharge tube.
FIG. 1A and FIG. 1B are diagrams for explaining a transition of the operating voltage of a conventional discharge tube immediately after a start of discharging.
The filler gas of the discharge tube of FIG. 1A and FIG. 1B is composed of 90% by volume of argon (Ar) gas and 10% by volume of hydrogen (H2) gas. In the following, all the chemical composition (%) of the filler gas is expressed in the volume concentration (percent by volume) unless otherwise specified.
Moreover, FIG. 2A and FIG. 2B are diagrams for explaining the results of measurement of an output voltage of the secondary coil of the transformer of the ignitor circuit to which the conventional discharge tube (the composition of the filler gas: 90% Ar+10% H2) of FIG. 1A and FIG. 1B is applied.
In addition, in the cases of FIG. 1A and FIG. 1B, the connection of the discharge tube is made in the "plus" direction and the "minus" direction, respectively. Namely, the direction of the connection is reversed between the cases of FIG. 1A and FIG. 1B.
As is apparent from FIG. 1A and FIG. 1B, after a start of discharging of the conventional discharge tube, the operating voltage is not reduced to the ground in a straight manner, but the phenomenon takes place in which the discharge voltage is raised for a certain period after the start of discharging, as indicated by the arrow A in FIG. 1A and FIG. 1B. In the following, this phenomenon will be called the rebound phenomenon and the discharge voltage at this time will be called the rebound voltage. The rebound phenomenon takes place regardless of whether the connection direction of the discharge tube is the "plus" direction or the "minus" direction as shown in FIG. 1A and FIG. 1B.
Moreover, as shown in FIG. 2A and FIG. 2B, the actual output voltage of the secondary coil of the transformer of the ignitor circuit at this time declines greatly, although the desired value of the output voltage is about 11 kV. This is because the decline of the output voltage is caused by the above mentioned rebound phenomenon.

Discharge tube with a specific amount of hydrogen gas by volume


A controlling apparatus for controlling a disk array unit includes a cache memory for caching data of the disk array unit; a nonvolatile memory for storing the data in the cache memory; and a control unit for detecting a defective location in the nonvolatile memory where the data is stored defectively and updating information indicating the defection location, for generating an error detection code of the updated information, for writing the generated information and the associated error detection code into an area of the nonvolatile memory different from any area where any information indicating any defective location previously detected and stored into the nonvolatile memory, and for controlling writing the data in the cache memory into a location of the nonvolatile memory designated by any selected one of the information stored in the nonvolatile memory.

RAID has a backup unit (battery) for preparing for a case in which electric powers supply cannot be carried out from an outside of a system such as power failure. In a case where the power failure is generated, in order to protect data held by a volatile memory mounted to a controller module, the RAID carries out the electric power supply from the backup unit to the volatile memory. Until the RAID recovers from the power failure, the backup unit keeps supplying the electric power to the volatile memory. Thus, the volatile memory keeps holding the data.
However, a limit exists on a power supply capacity of the backup unit. For that reason, a data guarantee of the volatile memory depends on an electric capacity of the backup unit. If the capacity of the backup unit is increased, a reliability of the data guarantee can be accordingly increased. However, if the number of the backup units is increased in the RAID, new problems occur such as an increase in costs and an increase in size of a RAID apparatus. Also, after the recovery from the power failure, until the backup unit is recharged, a guarantee for a backup cannot be made, and therefore a RAID system is in a write through state (for reporting a completion when the write into a disk is done). As a result, a problem also occurs in which a processing ability of the RAID system is considerably decreased.
Therefore, for the controller module, a backup method of saving the date held by the volatile memory into a nonvolatile memory is conceived, and a problem is how the data is certainly saved into the nonvolatile memory.
The following documents exist with regard to a backup control in the RAID system.
[Patent Document] Japanese Laid-open Patent Publication No. 05-346889, Japanese Laid-open Patent Publication No. 2006-277395, Japanese Laid-open Patent Publication No. 2004-318465, and Japanese Laid-open Patent Publication No. 09-305491.

Controlling apparatus and controlling method


An object of the present invention is to provide a composition for suppressing craving for smoking with high safety and no dependence such that there can be performed (1) suppression of craving for smoking in a situation where nonsmoking is mandatory in the daily life; (2) prohibition or moderation of smoking intentionally (when unrestricted); and (3) complete elimination of a smoking habit. Another object of the present invention is to provide a method for prohibiting or moderating smoking comprising administering to an individual the composition comprising theanine.

Smoking cigarettes has been known to be a major cause of diseases such as a lung cancer, bronchitis, and coronary or peripheral artery disease. Individual chemical substances contained in cigarettes have already been recognized as a carcinogen, and passive smoking has been elucidated to have carcinogenicity recently, so that smokeless chewing tobacco and snuff are also listed in carcinogenic substance list in the United States. Among the components contained in cigarettes, nicotine, which is a colorless volatile liquid alkaloid, has high toxicity of irritating and paralyzing the nerve tissue such as cerebral nerve, cerebellum and spinal cord while having calming effect, excitement effect and pleasure-giving effect. Therefore, there have been continuously reported that nicotine relating to the incidences of lung cancer, pharyngeal cancer, esophageal cancer and gastric cancer.
Nicotine also has mental dependence, so that a continual intake of nicotine by smoking or the like may cause nicotine dependence. For example, when a heavy smoker quits smoking, withdrawal symptoms are seen in a short time period and craving for smoking increases. If the smoker cannot tolerate his craving for smoking, and takes more nicotine to avoid the symptoms and torment, his health is staked at a higher risk.
In those times, campaigns for nonsmoking and moderation in smoking have been run worldwide, and a smoking population tends to be decreased every year. There is a trend toward restriction in smoking in public facilities and public transportation, so that a smoker frequently faces a situation in which he is forced to stop smoking. However, mental and physical torments may be caused by breaking a smoking habit in many cases, and a sudden drop in an intake of nicotine may cause serious withdrawal symptoms. For this reason, there is an earnest need for a method showing an effect on prohibiting or moderating smoking gradually without causing any problems.
As such methods, a food or a medicament such as nicotine gum, and candy, drop or gum, containing various plant extracts, an inorganic substance and the like has been so far known (Japanese Patent Laid-Open No. Sho 4-46119, Japanese Patent Laid-Open No. Sho 61-63243, Japanese Patent Laid-Open No. Sho 62-296840, Japanese Patent Laid-Open No. Sho 62-296840, Japanese Patent Laid-Open No. Hei 8-308544, Japanese Patent Laid-Open No. Sho 82-42582, Japanese Patent Laid-Open No. Hei 7-18076, and Japanese Patent Laid-Open No. Sho 48-85722). Moreover, a method of causing discomfort by inhaling a certain chemical substance simultaneously with cigarette smoke using a pipe or the like, and a method of promoting anti-smoking by absorbing nicotine into body using a nicotine pad or nicotine nasal spray have been used. The principles for prohibiting or moderating smoking by these means are classified into three categories: (1) suppression for craving for smoking by paralyzing gustation and the like; (2) promotion of a detoxification/excretion of nicotine in the body; and (3) supply of nicotine by a cigarette substitute. However, in a case where nicotine is absorbed transdermally or the like, nicotine exists internally after all, so that this method cannot be said to be good for health. Further, even when a reduction in the craving for smoking is achieved, there would be a risk for dependence on the cigarette substitute used. The above-mentioned food or the like has a little effect, and would not satisfactorily gratify smokers' gustation who is generally accustomed to nicotine, so that withdrawal symptoms originated from prohibition or moderation of smoking could not be fundamentally suppressed. Accordingly, it is often the case that a smoker cannot help smoking, so that their effectiveness has a certain limit.

Compositions for regulating desire for smoking


An inverter circuit for discharge lamps, in which transformers are separated into multiple small or middle-sized transformers connected to one another to provide a high-power transformer equivalent to a large transformer. The inverter circuit includes a plurality of leakage flux step-up transformers each having a magnetically continuous central core, a primary winding, and a distributed-constant secondary winding, wherein a part of a resonance circuit is formed among a leakage inductance produced on the secondary winding side, a distributed capacitance of the secondary winding and a parasitic capacitance produced around a discharge lamp close to a proximity conductor, and as the resonance circuit resonates, the secondary winding has a close coupling portion in a vicinity of the primary winding which has a magnetic phase close to that of the primary winding and magnetically close couples with the primary winding.

Recently, the use of multiple cold-cathode fluorescent lamps in a surface light source such as a liquid crystal display backlight becomes popular, which demands a high-power inverter circuit.
A high-power inverter circuit is generally realized by enlarging a step-up transformer and its drive circuit. Because even a slight power loss in a high-power inverter circuit leads to generation of large heat, a high efficiency inverter circuit is needed.
The present inventor has proposed in U.S. Pat. No. 5,495,405 (corresponding to Japanese Patent No. 2733817), as a high efficiency (a highly efficient) inverter circuit, a leakage flux transformer inverter circuit which utilizes an effect of improving the power factor as a result of reducing the exciting current flowing across the primary winding of a step-up transformer by resonating the secondary side circuit thereof.
Those high efficiency inverter circuits have been used as inverter circuits for notebook type personal computers with aims of making inverter circuits compact and highly efficient. Such an inverter circuit for a notebook type personal computer requires one leakage flux transformer and a resonance circuit on the secondary side per each cold-cathode fluorescent lamp, and has power of 5 W or so at a maximum.
Multiple cold-cathode fluorescent lamps are used in a surface light source such as a liquid crystal display backlight, and there is a demand of making the power of the associated inverter circuit greater accordingly.
There are multiple proposals on inverter circuits for high-power multi-lamp surface light sources. Many of the inverter circuits use multiple collector resonating circuits which are often used in the conventional inverter circuits. In one of the proposals, a single small leakage flux transformer is provided per two cold-cathode fluorescent lamps as shown in FIG. 2 for the purpose of reducing the overall cost for the inverter circuit.
When one wants a higher efficiency, however, it is effective to resonate the secondary side circuit as disclosed in U.S. Pat. No. 5,495,405. In this case, the collector resonating circuit and the resonance circuit present in the primary circuit interfere with each other, making it very difficult to adjust the circuit constant.
Since the exciting current which flows across the primary winding is used as the resonance current from the resonance circuit on the primary side according to the principle of the collector resonating circuit, the effect of improving the power factor cannot be utilized to a certain extent when the invention described in U.S. Pat. No. 5,495,405 invention is achieved by collector resonating circuits. In this respect, another exciting circuit or so which can extremely reduce the exciting current is frequently used.
In either case, those inverter circuits are each designed merely in such a way that multiple small high efficiency inverter circuits are laid out in proportion to the number of cold-cathode fluorescent lamps, and are thus complicated.
It is the step-up transformer and the drive circuit in the inverter circuit for a high-power surface light source that require the cost most, so that the required use of the step-up transformer and the drive circuit causes the overall cost for the inverter circuit to increase.
While it is necessary to achieve cost reduction for an inverter circuit for discharge lamps by reducing the number of step-up transformers and drive circuits by making the power of the step-up transformers greater, it is difficult to drive cold-cathode fluorescent lamps in parallel.
The difficulty arises from the following reason. A cold-cathode fluorescent lamp has a negative impedance characteristic such that the voltage falls as the current increases. Even with an attempt to drive cold-cathode fluorescent lamps in parallel, therefore, when one of the parallel-connected cold-cathode fluorescent lamps is lighted, this cold-cathode fluorescent lamp lighted first drops the lamp voltages of the other cold-cathode fluorescent lamps connected in parallel. As a consequence, all the cold-cathode fluorescent lamps except for the cold-cathode fluorescent lamp that is lighted first are not lighted.
As a solution to this problem, a scheme of stably driving multiple cold-cathode fluorescent lamps in parallel has been proposed by the present inventor in U.S. Ser. No. 10/773,230 (corresponding to Japanese Patent Application No. 2004-003740) as shown in FIG. 3, in addition to the suggested use of cold-cathode fluorescent lamps which can be lighted in parallel, such as an external electrode fluorescent lamp (EEFL).
As parallel driving of multiple cold-cathode fluorescent lamps becomes possible, a high-power step-up transformer becomes necessary to drive the transformers. In an inverter circuit for discharge lamps, like cold-cathode fluorescent lamps, which require a high voltage, it is very difficult to make the power of the step-up transformer higher for the following reason.
First, increasing the power of the step-up transformer requires that the transformer should be made larger. This naturally increases the thickness of the transformer, which is not allowed to become too thick due to the particular demand of designing liquid crystal display backlights thinner besides compactness.
Because the shape of the transformer greatly influences the parameters thereof and the relationship between the cross-sectional area of the magnetic path and the length of the magnetic path should be kept at a constant ratio, however, the shape of the transformer does not have a high degree of freedom. When a thinner design is sought out, the length of the magnetic path should be greater than the cross-sectional area of the magnetic path. This leads to a smaller coupling coefficient k of the transformer, resulting in a larger value of the leakage inductance Le (as defined by The Institute of Electrical Engineers of Japan (IEEJ)) to the self-inductance Lo. The term "leakage inductance" defined in books published by IEEJ differs from the same term "leakage inductance" obtained by the JIS measuring method. To distinguish the leakage inductances, therefore, the former leakage inductance is called "leakage inductance Le (IEEJ)", and the latter is called. "leakage inductance Ls (JIS)". Both leakage inductances can be mutually converted by an equation given below.
The leakage inductances have the following relationship.
The leakage inductance Le (IEEJ) is given byLe=(1−k)·Lo.
The mutual inductance M is given byM=k·Lo.
The leakage inductance Ls (JIS) is given by
      L    s    =            1                        1                      L            e                          +                  1          M                      +          L      e
It is apparent that as the leakage inductance Le (IEEJ) increases, the leakage inductance Ls (JIS), which is an important parameter to constitute a resonance circuit on the secondary winding side, becomes larger.
In constructing a high efficiency inverter circuit described in U.S. Pat. No. 5,495,405, it is desirable that the leakage inductance Ls (JIS) should have the following relationship with the impedance Zr of the discharge lamp.|XL,≦|Zr|
This means that a high efficiency inverter circuit can be realized when the reactance of the leakage inductance Ls (JIS) at the operational frequency of the inverter circuit is nearly equal to or slightly smaller than the impedance of the discharge lamp. This relational equation applies effectively to an inverter circuit for a large surface light source as well as to an inverter circuit for a notebook type personal computer.
If multiple cold-cathode fluorescent lamps are driven in parallel with an increase in the power of the surface light source, therefore, impedance Zr of the discharge lamp is the impedance of the cold-cathode fluorescent lamps divided by the number of the cold-cathode fluorescent lamps and is thus a small value. The relationship between the leakage inductance Ls (JIS) and the impedance Zr indicates that a high efficiency inverter circuit can be realized when the reactance of the leakage inductance Ls (JIS) at the operational frequency of the inverter circuit is equal to or slightly smaller than the impedance of the discharge lamp. This means that the leakage inductance Ls (JIS) needed for transformers for a high-power inverter circuit should be small.
When the shape of the step-up transformer is restricted so as to match with the flat shape actually demanded for a liquid crystal display backlight, however, the leakage inductance Ls (JIS) should become large as explained above. It is very difficult to design a flat and high-power transformer.
Another important factor is the speed of a progressive wave which is generated on the secondary winding. First, as the shape of the transformer becomes larger with an increase in power, the self-resonance frequency of the secondary winding becomes lower. The self-resonance frequency of the secondary winding in the inverter circuit for cold-cathode fluorescent lamps is associated with the step-up effect and is therefore an important parameter. The relationship will be described in detail below.
The windings of a transformer are in a state of a distributed-constant as shown in FIG. 4 in a detailed illustration including the influence of the distributed capacitance. The influence of the distributed constant of the windings is analyzed in detail as a countermeasure against breakdown of a power transformer originated from the lightening surge as described in, for example, "Transformer in Power Device Course 5" (published by The Nikkan Kogyo Shimbun, Ltd.). It is known from the literature that the windings of a transformer form a delay circuit having a specific distributed constant. The influence of such a property appears noticeably when multiple very thin wires are wound up as done for the secondary winding of a step-up transformer for cold-cathode fluorescent lamps.
In the actual step-up transformer for cold-cathode fluorescent lamps, the distributed constant of the secondary winding appears around the self-resonance frequency or at a frequency higher than the self-resonance frequency. As the secondary winding forms a delay circuit, transmission delay of the energy occurs from that portion of the secondary winding which is close to the primary winding to that portion of the secondary winding which is far from the primary winding, as shown in FIGS. 5 to 7. This phenomenon is so-called phase-shift or phase modification wherein the phase is delayed gradually. The term "phase modification" is known in the field of motors or the like.
The phase modification in the present invention is called "phase-modifying transformer" by Electrotechnical Laboratory (currently, National Institute of Advanced Industrial Science and Technology) when authorized to do a subsidized research of Kanto Bureau of International Trade and Industry in Ministry of International Trade and Industry (currently, Kanto Bureau of Economy, Trade and Industry) in 1996. The phase modification phenomenon results in that the current phase of that portion of the secondary winding which is close to the primary winding becomes close to the current phase of the primary winding, so that a large portion of the flux generated on the primary winding penetrates the secondary winding, thus forming a close coupling portion, as shown in FIG. 8.
This structure noticeably appears in the vicinity of the frequency at which the leakage inductance Ls (JIS) of the secondary winding and the capacitive component on the secondary side resonate, but does not appear when no resonance takes place.
Therefore, the resonance of the leakage inductance Ls (JIS) of the secondary winding and the capacitive component on the secondary side is essential in the appearance of the structure of close coupling and loose coupling.
The current phase of the portion of the secondary winding which is far from the primary winding is delayed from the current phase of the primary winding, so that a large portion of flux leaks from the secondary winding, thus forming a loose coupling portion. At the loose coupling portion, as shown in FIG. 8, most of the flux that has penetrated from the primary winding leaks, so that the leakage flux leaks differently from that in the prior art and, even with the same leakage inductance, a larger amount of flux leaks at the loose coupling portion than that in the prior art. That is, a so-called extreme leakage flux is produced. (In FIGS. 5 to 8, not only 100% of the magnetic flux or more leaks, but also 35% of a magnetic flux of the opposite phase is generated.) Such flux leakage phenomenon differs from the behavior of the leakage flux in the prior art. FIG. 9 shows the behavior of the leakage flux in the conventional transformer illustrated for readers' reference.
As a signal which travels on the secondary winding with a distributed constant has a given propagation speed due to such a phase delay phenomenon, the signal has a given wavelength from the relationship with the drive frequency. The propagation speed is about several Km/sec for a transformer in an inverter circuit for cold-cathode fluorescent lamps. Consequently, a progressive wave is generated on the secondary winding of the transformer in the inverter circuit. Given that the wavelength of the progressive wave is λ, when the wavelength of ¼λ coincides with the physical length of the bobbin of the secondary winding, a resonance phenomenon similar to the resonance of an antenna or the resonance of an acoustic resonant body as shown in FIG. 10 occurs. In this case, the resonance frequency of ¼λ is the self-resonance frequency of the secondary winding itself, so that the resonance frequency of ¼λ can be known by actually measuring the self-resonance frequency of the secondary winding of the transformer.
In the general knowledge, the step-up ratio of the transformer becomes greater as the transformation ratio becomes larger. On the contrary, detailed observations show that such is not true at a frequency close to the self-resonance frequency. The transformer shows the maximum step-up operation at a frequency at which the self-resonance frequency, which is the resonance frequency of the self-inductance of the secondary winding and the distributed capacitance of the secondary winding (parasitic capacitance between windings), becomes equal to the operational frequency of the inverter. That frequency is the resonance frequency of ¼λ.
When the self-resonance frequency becomes lower than the operational frequency of the inverter, the transformer gradually loses the step-up operation. When the self-resonance frequency further drops and becomes a half the operational frequency of the inverter, the transformer does not make the step-up operation at all. This is because at the resonance frequency of ½λ, the current phase of the secondary winding at a far end portion which is apart from the primary winding is delayed by 180 degrees from, and becomes opposite to, the current phase of that portion of the secondary winding which is close to the primary winding.
When the self-resonance frequency becomes lower than the operational frequency of the inverter, various phenomena, such as suppression of the step-up operation and generation of a voltage of the opposite phase, may occur. In the general knowledge, however, the step-up operation has not been thought in such a concept.
That is, it is the conventional knowledge that the transformation ratio should simply be increased to gain the step-up ratio, so that an insufficient step-up ratio when pointed out is coped with winding the secondary winding more.
This measure however leads to excessive winding of the secondary winding, which often results in a lower self-resonance frequency of the secondary winding. Although the step-up ratio may be repressed due to the excessive winding of the secondary winding, it is often the case that when the proper step-up ratio is not obtained, an attempt is made to wind the secondary winding more to gain the step-up ratio. The excessive winding of the secondary winding, further lowers the self-resonance frequency. This results in a vicious circle of suppressing the step-up ratio more. As apparent from the above, the self-resonance frequency of the secondary winding of the transformer has a significance in the step-up transformer for cold-cathode fluorescent lamps and care should be taken not to make the self-resonance frequency too low.
From the viewpoint of the coupling coefficient, the self-resonance frequency can be set high to a certain degree by increasing the number of sections of the secondary winding of the transformer. Setting the number of sections larger means that the coupling coefficient becomes smaller and the leakage inductance becomes larger.
Because the impedance of a load to be driven in a high-power inverter circuit is low, the leakage inductance in a high-power transformer should be made smaller in proportion to the load. Therefore, there is a limit to increasing the number of sections. As the transformer becomes larger, the self-resonance frequency inevitably becomes lower, so that contradictory conditions should be satisfied to reduce the leakage inductance and acquire a transformer with a high self-resonance frequency. Needless to say, designing the transformer is difficult.
The secondary winding of the transformer has a distributed constant and forms a delay circuit. The secondary winding therefore has a characteristic impedance from the theory of a high-frequency transmission circuit. To form the ideal close coupling portion/loose coupling portion structure, the characteristic impedance which is determined by the size of the bobbin of the transformer, the cross-sectional area of the core, the magnetic path and the winding of the secondary winding should be matched with the impedance of the load of the discharge lamp.
Without impedance matching, an echo is generated, so that the ideal delayed waveform is not acquired, resulting in generation of a standing wave. As a result, the leakage flux on the secondary winding does not become uniform, disabling the achievement of the ideal conditions to ultimately minimize the core loss.
To reduce heat generated in a high-power transformer, the copper loss and the core loss should be minimized. However, with a requirement of a flat shape added to the difficult requirement that three conditions of the leakage inductance, the speed of the progressive wave (i.e., the self-resonance frequency) and the characteristic impedance should be met, it becomes harder to design a transformer which satisfies all the conditions at a time.
Several attempts have been made to achieve a high-power step-up transformer by connecting a plurality of transformers in parallel.
FIG. 18 shows an example of a discharge lamp which is driven with a pulse signal and is disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2000-138097.
In the example, an attempt is made to realize a high-power step-up circuit by connecting both the primary windings and the secondary windings of a transformer which drives a discharge lamp to be driven with a pulse signal. In particular, a pulse transformer requires that the leakage inductance should be particularly small because a large leakage inductance disables the supply of a sharp pulse with a large value of di/dt.
Generally speaking, however, when transformers with very small flux leakage are connected in parallel, the current may flow between the secondary windings of the transformers and reduce the efficiency or heat may be generated due to variations in the characteristics of the individual transformers. In this respect, the example disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2000-138097 uses resistor components of the secondary windings of the transformers to disperse the load evenly over the individual transformers.
That is, the parallel connection of transformers essentially requires the reactance for parallel connection. With insufficient reactance, the load to be dispersed over the transformers does not become uniform, so that when multiple transformers are connected, the load is concentrated on some transformers.
When the reactance is given by a resistor component, reduction in efficiency by the generation of the Joule heat should be taken into consideration.
When a discharge lamp is driven with a sine wave of 40 KHz to 100 KHz as done for a cold-cathode fluorescent lamp, the leakage inductance larger than that needed for pulse driving is required to acquire the reactance for parallel connection. Conventionally, in the case of driving a cold-cathode fluorescent lamp, ballast capacitors are often connected in series as the ballast reactance. The step-up transformer in this case does not use the resonance of the secondary side circuit as used in U.S. Pat. No. 5,495,405. The transformers to be used in this case have a small leakage inductance and are of course unsuitable for parallel connection. In addition, the transformation ratio of transformers which are not resonated reflects on the step-up ratio directly, so that for parallel connection, the step-up ratio should be controlled strictly so as to have no variation.
FIG. 19 shows an example of parallel connection disclosed in Japanese Laid-Open Patent Publication (Kokai) No. H10-92589, where the transformer has a small leakage inductance and the secondary side circuit is not resonated. In this case, when the secondary windings of the transformers are connected in parallel, the current that flows between the secondary windings may increase, generating heat.
To acquire parallel connection of transformers having small leakage inductance, therefore, a practical inverter circuit is difficult to design unless the parallel connection is made via ballast capacitors as shown in FIG. 20.

Inverter circuit for surface light source system


There is provided a system and method for monitoring an apparatus from a remote location. A vendor-side computer obtains operating state data obtained by a monitoring device provided in an apparatus via a communication line, and monitors the operating state of the apparatus from a remote location. Maintenance data at a part replacing time is transmitted from the apparatus, and the vendor-side computer that has received maintenance data calculates an optimal replacement period of a part based on this. The calculated optimal replacement period of each part is sent to a plant. The plant feeds the optimal replacement period back to the operation of the apparatus, so that productivity can be improved.

In recent years, the life cycle of industrial products, particularly electronic devices become extremely short due to more intensification in development competition between manufactures. Under such circumstances, the manufactures for the electronic device manufacturing apparatus are required to provide the manufacturing apparatus that can ensure high productivity for products and maintain it. More specifically, it has been demanded to provide the manufacturing apparatuses that can manufacture more products at the same time and can perform the same amount of productions with the small number of apparatuses.
In order to ensure and maintain the high productivity, there is need of an effective operation of the apparatus used in manufacturing the products. The operational management of the apparatus for production at the plant is performed using generally the operation rate as an index. Regarding the operation rate of the apparatus, the value under test conditions is generally decided, but is different depending on the client's operational condition. For this reason, the operation rate of the apparatus is decided between a vendor that provides apparatuses and the manufacturer that is a user. For example, when an operational reference is set to the operation rate of 90% with respect to a certain apparatus, the manufacturer that uses the apparatus and the vendor that supports the apparatus perform the maintenance management of the apparatus such that the operating state of the apparatus satisfies the above value.
The maintenance management can be largely divided into corrective maintenance, breakdown maintenance, and preventive maintenance. In general, corrective maintenance is mainly performed to operate the apparatus stably at the initial time of using the apparatus. Then, after the apparatus satisfies a predetermined operation rate is satisfied and the apparatus reaches a stable operating state, the breakdown maintenance and preventive maintenance become important to keep the operating state. The breakdown maintenance indicates posterior maintenance management that is provided after trouble occurs in the apparatus. The preventive maintenance is preventive maintenance management that identifies the location where occurrence of trouble is predicted to provide maintenance management to the location intensively.
Furthermore, the operation rate can be expressed by [(operational time)−(stop time)]/(operational time)×100(%). Operational time is time for which the apparatus should be in an operational status. Accordingly, a value obtained by subtracting stop time from the operational time, indicates effective (real) operation time of the apparatus. As is obvious from this equation, in order to obtain high operation rate to ensure high throughput, it is necessary to shorten operation stop time of apparatus.
As a method for shortening stop time, there is known a method in which maintenance management system that performs maintenance management (breakdown maintenance) of the apparatus is automated to shorten sudden stop time such as trouble occurrence time and the like. For example, information exchange on the apparatus operational status and trouble status between the vendor and the manufacturer is made online to be automated; thereby this can be carried out. Unexamined Japanese Patent Application KOKAI Publication No. H11-15520 discloses a remote-monitoring (remote-maintaining) system, which makes such breakdown maintenance efficient, between the single vendor and the manufacturer.
The above-disclosed remote-marinating system is composed of apparatuses provided at a plurality of plants, a host computer for monitoring provided at each plant, and a host computer for management, which is connected to the host computer of each plant via a communication line and which is provided at a vendor's office that supplies the apparatuses. The host computer at the plant (manufacturer) side always monitors the apparatus. While, the host computer at the vendor side monitors whether there is a report on trouble occurrence and obtains it if there is a report on trouble occurrence. Then, the host computer at the vendor side analyzes the report on trouble occurrence and transmits information indicating treatment to the plant side.
However, in the above-disclosed remote-maintenance system is structured such that the host computer for monitoring is directly connected to the apparatus to perform transmission, and it is preferable that monitoring and transmission are separately performed. Moreover, since the production is uniquely placed in the apparatus, there is a possibility that the method for transmitting a large amount of data including other data excepting one for remote-maintenance to the vendor via the host computer will decrease the throughput of the apparatus, and this is not realistic.
By the way, regarding the way of thinking about the maintenance management, the preventive maintenance "fix before breakdown" is becoming the mainstream instead of the breakdown maintenance "fix after breakdown". The preventive maintenance can prevent trouble occurrence and reduce the sudden stop of the apparatus by sufficient preventive maintenance. However, even in when the preventive maintenance is performed, it is necessary to stop the apparatus, and the frequent or inefficient preventive maintenance reduces the substantial operation rate of the apparatus and suppresses productivity. In addition, the preventive maintenance can execute not the sudden maintenance but a planed maintenance to make it possible to carry out a planned production. For this reason, as a system for ensuring the high operation rate of apparatus, there has been a system that is capable of carrying out efficient maintenance management including the preventive maintenance.

Apparatus productivity improving system and its method


An arrangement area of a transformer drive circuit, an arrangement area of a high-voltage transformer, and an arrangement area of an ion generating unit are two-dimensionally divided from each other in a casing. A connection terminal is electrically connected to the transformer drive circuit and is formed of a conductive film arranged to be exposed to the outside of the casing. Accordingly, an ion generating device whose size and thickness can be easily reduced and an electrical apparatus including the ion generating device can be provided.

Many ion generating devices that utilize a discharge phenomenon have been put into practical use. These ion generating devices generally include an ion generating unit for generating ions, a high-voltage transformer for supplying a high voltage to the ion generating unit, a high-voltage transformer drive circuit for driving the high-voltage transformer, and a power supply input portion such as a connector.
Ion generating units may be roughly categorized into two types. One type uses a metal wire, a metal plate having an acute portion, a needle-shaped metal part, etc., as a discharge electrode and a metal plate, a grid, etc., at a ground potential as a counter electrode. The counter electrode may be omitted when the ground is used as a counter electrode. In this type of ion generating unit, air serves as an insulator. When a high voltage is applied between the electrodes of the ion generating unit, an electric field concentration occurs at the tip of the electrode having an acute portion and electrical breakdown of air occurs in the immediate vicinity of the tip, so that a discharge phenomenon is produced.
The other type includes a pair of electrodes, which are an induction electrode embedded in a high-breakdown-voltage dielectric and a discharge electrode disposed on a surface of the dielectric. When a high voltage is applied between the electrodes of the ion generating unit of this type, an electric field concentration occurs in the vicinity of an outer edge portion of the discharge electrode on the surface of the dielectric and electrical breakdown of the air occurs in the vicinity of the outer edge portion, so that a discharge phenomenon is produced.
Japanese Unexamined Patent Application Publication No. 2002-374670 (see PTL 1) describes an example of an ion generating device according to the related art. This ion generating device is of the type which includes a discharge electrode as an ion generating electrode and includes no counter electrode. In this ion generating device, a piezoelectric transformer that supplies a high voltage to the ion generating electrode and a drive circuit for driving the piezoelectric transformer are mounted in a casing in an integrated manner through molding. The ion generating electrode is disposed outside the casing and connected to a cable that extends from the inside of the casing.
Japanese Unexamined Patent Application Publication No. 2008-016345 (see PTL 2) discloses a structure of an ion generating device whose thickness is reduced by two-dimensionally arranging an ion generating unit, a transformer drive circuit, and a transformer in a casing and disposing the transformer separately from a circuit board.

Ion generating device and electrical apparatus which can easily be reduced in size and thickness


Techniques for dynamic prioritization of network session are provided. A first packet belonging to a first session is received at a data plane of a network. Upon determining that the first packet is part of a first roam event, a first bloom filter bank is searched to determine a priority associated with the first session, where the priority is based at least in part on a historical latency experienced during the first roam event. A first queue of a plurality of queues is selected based on the determined priority, and the first packet is added to the first queue, where packets in the plurality of queues are transmitted to a control plane of the network based on a respective priority assigned to each of the plurality of queues.

As wireless devices migrate between network access points, a handoff procedure occurs to transfer the connection from the first access point to the second. This roam event must occur smoothly, or the device will see connectivity drops or delays. As devices are increasingly used for real-time (and often high-bandwidth) data, it has become ever more vital that the roam is handled quickly, or the user will perceive the interruption. For example, if a voice or video stream is interrupted for too long during the roam, a noticeable drop can occur, which reduces the quality of service provided to the user. Additionally, as new controller architectures and protocols evolve with increasing complexity and features, the overhead and delay involved in roam events has similarly increased.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially used in other embodiments without specific recitation.

Dynamic prioritization of roam events based on latency


A maintenance-free dental prophylaxis angle includes a one-piece body including a sleeve and a head. The sleeve and head define intersecting bores. A drive assembly, comprising a drive gear and a bushing, is force fitted in the sleeve. A one-piece driven gear is received in the head bore to be driven by the drive assembly. The driven gear includes an upper bur tube, a gear part, and a lower shaft. The gear part of the driven gear rests on an upper face of a boss in the head, the boss forming a thrust bearing for the driven gear. Intersecting bores in the boss form part of a lubricant circulating system. A metal cap is force fitted in the head bore to close the head bore and retain the driven gear in place in the head. A dental tool is connected to the bur tube of the driven gear, and forms a seal with the cap.

This invention relates to dental prophylaxis angles (commonly referred to as prophy angles). It has particular application to a prophy angle which need not be lubricated even after repeated autoclave cycles. It also has more general application to making a simple prophy angle with a particularly effective driven gear and thrust bearing for its driven gear.
Prophy angles currently available are either low-cost disposable prophy angles which are discarded after each use or else expensive reusable metal prophy angles which require a considerable amount of care to maintain. A reusable angle must not only be autoclaved between uses or procedures to ensure that the angle is sterile for the next procedure, but it must be maintained. Reusable angles need to be lubricated to run smoothly. The lubrication, however, breaks down and is lost over time through use and because of the autoclaving. Reusable angles must therefore be disassembled periodically to be lubricated. Some manufacturers recommend that prophy angles be lubricated after every ten hours of use. If the angle is not lubricated, the angle will eventually seize up and become inoperable. Through use, debris may also find its way into the angle's head. This debris can interfere with the operation of the angle's gears, and can ultimately ruin the gears. The angle must therefore also be cleaned periodically, to remove any debris, such as grit, which may have found its way into the angle. Many dentists and hygienists do not lubricate and clean their prophy angles on a regular schedule. If the angles are not lubricated and cleaned periodically, they will eventually fail.
An example of an expensive, high-quality reusable prophy angle is the TS2.TM. angle sold by Young Dental Manufacturing Company of Earth City, Mo. This angle is shown in FIG. 1. All of the parts are machined from bronze and stainless steel. A body B terminates in an externally threaded stud B1. A drive gear member D includes a shaft DS rotatably mounted in an axial bore of the body and a drive gear DG butted against the end of the stud B1. A head part H is threaded onto the stud B1. The head part includes an axial bore HB and a bore extension HE. A post P is press fitted into the bore extension HE. The post P acts as a thrust bearing for a driven gear Dn. The driven gear Dn includes a gear part DnG and an upwardly-extending internally threaded bur tube DnT. A cap C is threaded into the open end of the head bore and forms radial bearings for the driven gear. A stem CS on the outside of the cap terminates in an externally beveled knife edge, a short distance above the top of the bur tube. Specially designed dental tools, such as prophy cups manufactured by Young Dental Manufacturing Company, when they are screwed into the bur tube DnT, form a seal with the stem CS and prevent intrusion of material from the patient's mouth into the angle. One manner of forming the seal is described in my U.S. Pat. No. 5,484,284.
An alternative to single-use disposable prophy angles and expensive reusable angles has been proposed in Wiseman, U.S. Pat. No. 3,163,934. That patent discloses a relatively low-cost prophy angle whose body, cap, and drive shaft bearing are made of polypropylene, and whose drive gear, driven gear, bearing-locking collar, and ball thrust bearing are made of metal. A small quantity of silicone lubricant is packed into the head (nose) of the angle. Although this angle is designed to be sealed and to be repeatedly sterilized, it is not sufficiently sealed to prevent intrusion of materials from the patient's mouth or leakage of lubricant during use, and it does not lend itself to repeated autoclaving. Moreover, its construction does not lend itself to precise alignment of the moving parts, thereby increasing the difficulty of making the instrument run smoothly, quietly, and reliably. The construction requires seven separate parts and relatively complicated assembly.

Permanently lubricated dental prophylaxis angle


A system is provided for alerting of potential vehicle damage when moving into or out of a confined space, the confined space having a side structure which can damage the vehicle when moving into the confined space if the vehicle is too close to the side structure. The system comprises a beam transmitter for transmitting a beam, and a beam receiver for receiving the beam. The beam travels along a path at an angle relative to a ground surface of from about 40 degrees to 60 degrees. An alert generator generates an alert such as light, sound, or both, when a vehicle intersects the beam.

When vehicles are moved into a confined space, damage to one or more sides of the vehicle can occur. For example, a side mirror can be damaged or knocked off the vehicle by a garage wall or garage door track, or a fender can be damaged. The mirror can be costly to replace.

System for protecting vehicles from damage in a confined space


Techniques for producing an optical broadband frequency sweep or chirp, include generating a narrowband frequency chirp and a frequency-shifted replica. The narrowband chirp has an optical carrier frequency, a pulse duration and a pulse bandwidth. A frequency-shifted replica is generated by frequency shifting the narrowband chirp by a frequency shift. Adding the frequency-shifted replica after a start of the narrowband chirp by a delay generates a broadband frequency chirp. Alternatively, the frequency-shifted replica is generated by frequency shifting a constant frequency pulse, and modulating the frequency-shifted pulse to generate narrowband chirps that are added to form the broadband chirp.

1. Field of the Invention
The present invention relates to a method and apparatus to enable wide bandwidth coverage of an optical spectral region with a temporal sequence of several narrowband optical frequency chirped pulses that are each frequency shifted.
2. Description of the Related Art
Optical linear frequency modulation (LFM) signals, i.e., frequency sweeps or "chirped" signals (also called "chirps") have many uses in optical devices and processors. For example, chirps can be used to generate optical signals, to interact with optical signals, and to probe the optical spectral contents of devices or materials.
In a recent approach described in Merkel I, a temporally extended chirp is used as a probe waveform to generate a readout signal that represents a temporal map of the structure of the spectral population grating in an inhomogeneously broadened (IBT) material, rather than its Fourier transform. This temporal map signal can be measured with inexpensive, high-dynamic-range, MHz bandwidth detectors and digitizers. Such chirps generally have a duration greater than the decoherence time and less than the population decay time of the inhomogeneously broadened absorption spectrum in IBT material. As described in Merkel I, a chirp sweeping over some wideband portion of the IBT frequency absorption profile of interest e.g., typically in excess of 1 GHz can produce a low-bandwidth readout signal that can be detected and digitized with the low-bandwidth high-dynamic-range devices currently available. This low-bandwidth readout signal represents a temporal map of the spectral features in the spatial-spectral grating. For example, in some cases the readout signal includes a temporal spike that represents a single frequency hole burned in the IBT material, and in other cases the readout signal includes a superposition of low-bandwidth beat frequencies, each beat related to a periodic component in the frequency spectrum of the grating.
However, current known techniques for producing spectrally pure, phase continuous radio frequency chirps that are linear in frequency and very stable are limited to pulses with bandwidths less than about 400 MHz. For example, direct digital synthesis (DDS) of radio frequency signals with a digital to analog converter (DAC) produces a given sample rate and with given bits in the resolution for each sample. For example, with currently available state of the art DDS techniques, using a high clock rate and high-dynamic-range digital to analog converters (e.g., AD9858, 10 bit DDS at 1000 Ms/s, available from Analog Devices of Norwood, Mass., 1 Ms=a Mega sample=106 samples; a bit denotes the number of base 2 levels in a quantized system, i.e., 10 bits=210 quantized levels), a linear, repeatable, stable and phase continuous RF chirped pulse can be created with a bandwidth covering less than about 500 MHz (e.g., 0 to 400 MHz). The RF chirp can be impressed on an optical signal using an optical modulator such as an electro-optical modulator (EOM) or an acousto-optic modulator (AOM).
EOMs modify the optical carrier with double sidebands one above and one below the carrier frequency. AOMs shift the frequency of the optical beams and deflect optical beams by an angle proportional to the frequency shift. Optical beams can be double passed through an AOM to double the bandwidth of the RF signal, and remove angular deflections in the modulated beam. AOMs can be made single sideband easily because the carrier and second sideband beam are in different directions than the modulated beam with the first sideband.
Optical rings with a frequency shifter are known to produce a wide range of optical frequencies from a given optical frequency. See for example, K. Shimnizu, T. Horiguchi, Y. Hoyamada, "Technique for translating light-wave frequency by using an optical ring circuit containing a frequency shifter," Optics Letters, vol. 17, p1307, 1992; Takesue et al., "Stable Lightwave Frequency Synthesis Over 1-THz Span Using Fabry-Perot Cavity Containing Polarization-Rotation Elements and Actively Controlled Tunable Bandpass Filter," IEEE Photonics Technology Letters, vol. 12, p79, 2000; the entire contents of each of which are hereby incorporated by reference as if fully set forth herein. Similar rings have been used to produce a sweep of discrete frequencies. See for example, M. Ishikawa, H. Yasaka, F. Kano, Y. Yoshikuni, "Optical frequency sweeper using an optical ring circuit with a tunable injection-locking filter," IEEE Photonics Technology Letters, vol. 11, n12, p1668, 1999; and U.S. Pat. No. 5,786,930 by Takatsu et al., issued Jul. 28, 1998; the entire contents of each of which are hereby incorporated by reference as if fully set forth herein.
While some of these references claim to generate optical frequency sweeps, in every case the frequency shift (Δf) imparted to an input signal at each pass through the loop is much greater than the bandwidth of the input signal, which is a single optical frequency (an optical "tone"). Thus the optical "sweeps" generated in the references are not continuous in frequency, even for short frequency ranges, but are noticeably stepped, i.e., they produce a series of discrete frequencies. The frequency gaps they leave make them unsuitable for reading out most spectra programmed into an IBT material, or other applications of interest wherein quasi-continuous coverage of broad bandwidths with optical frequency chirps are desired. As used herein the terms quasi-continuous frequency sweeps (or quasi-continuous chirps) are used to indicate chirps that are continuous in frequency for a least short frequency ranges, to distinguish such sweeps or chirps from the discrete frequency sweeps of prior art approaches.
Based on the foregoing, there is a clear need for techniques to produce a wideband frequency chirp that does not suffer the disadvantages of prior art approaches. In particular, techniques are needed to generate a stable, linear frequency chirped pulse over frequency ranges of much greater than 1 GHz, with RF sources that have bandwidths that are presently less than 1 GHz. Additionally, or in the alternative, there is a particular need for a linear, stable wideband frequency chirp with a wide bandwidth and an appropriate chirp rate to create a temporal map of the entire frequency band of interest in an IBT material.
The past approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not to be considered prior art to the claims in this application merely due to the presence of these approaches in this background section.

Method and apparatus for optical broadband frequency chirp


An application program and computer system for determining the testing profile for accelerated laboratory random vibrational testing of a product, including the application program steps of (i) selecting the frequency range covered in the laboratory accelerated testing, (ii) developing a simplified composite Power Spectral Density function PSD.sub.j (f) representative of the PSD for random vibration loadings in expected field vibration levels, (iii) developing the shape of PSD.sub.T for producing on the product the test acceleration forces corresponding to the PSD.sub.j function, (iv) calculating the stress response curve H(f) for the product representative of the transmissibility function from the input acceleration forces to the local vibration stress forces, (v) selecting the test duration, and then calculating the amplification factor from the relationship ##EQU1## (vi) recalculating the accelerated PSD profile, PSD.sub.T (f) for testing based on the selected test duration and the amplification factor: ##EQU2## and then (vii) testing the product using the selected PSD function, to validate the required performance lifetime for the product when no test failures are observed over all of the T hours.

1. Field of the Invention
The present invention relates to a method for validating the operational durability of an automotive component product based upon accelerated laboratory random vibration tests employing the principles of physics-of-failure and damage correlation.
2. Description of the Prior Art
In the automotive industry, sinusoidal vibration testing is frequently used due to the low equipment cost and convenience. However, the random vibration test is more desirable because the vibration loading applied on automotive components during actual operating conditions comprises the combination of several random processes corresponding to several different field driving routes. Therefore, a random vibration test conducted in the laboratory can better simulate field loading conditions. Random vibration tests in product validation process is possible now due to the availability of the random vibration test equipment and facilities.
However, it would be desirable to accelerate the testing time by elevating the random vibration profile in some manner. Most current accelerated testing methods are based on a load analysis approach which evaluates the input load and disregards small amplitude loads, regardless of frequency. This approach may cause significant errors, because failure of a product is a stress driven phenomenon and not load driven. Small amplitudes of load may induce large stresses. A more correct accelerated testing methodology must include the considerations of stress response of the product and material damage properties. This combination can best be implemented using the physics-of-failure approach.
An objective of the present invention is to develop a testing methodology to determine random vibration testing methodologies based on the physics-of-failure and damage equivalence technique such that the vibration damage generated in laboratory testing will be equivalent to the damage induced by random vibration in the field. Based on field random vibration profiles and the desired product life goal, an equivalent random vibration test in a laboratory environment, including the vibration level and test time, may be defined. If a product survives this laboratory test profile, it should survive in the field during the desired life time.

Computer program, system and method to specify random vibration tests for product durability validation


Methods and computer-readable media are provided for determining design parameters for oil well casing and tubing to prevent buckling in deviated wellbores. Well parameter data including tubing size, tubing weight, well depth, and well geometry is obtained and may be utilized to calculate parameters for predicting the movement of tubing near a packer or centralizer in the deviated wellbore based on the received well parameter data, predicting a total bending moment near the packer or centralizer, predicting a maximum bending stress near the packer or centralizer based on the total bending moment, and predicting the minimum axial force necessary to initiate buckling due to friction, and predicting the onset of buckling for the connection of tubing of different sizes. After the parameters have been calculated, they may be utilized in the design of the oil well casing and tubing to prevent buckling in the deviated wellbore.

In an oil well, casing is typically installed to withstand various pressures which may be present in an open hole or wellbore and to stabilize the pipes or tubing used for drilling. Typically, casing hangs straight down in vertical wells or lies on the low side of the hole in deviated wells. During drilling operations, thermal or pressure loads within a wellbore may produce compressive loads which, if sufficiently high, will cause the initial well configuration to become unstable. However, since the tubing is confined within the casing (or alternatively an open hole), the tubing can deform into another stable configuration, which may be a helical or coil shape in a vertical well or a lateral "S" shaped configuration in a deviated well. The change to the new configurations caused by the deformed tubing is known as "buckling."
In tubing and casing design, the accurate analysis of buckling is important for several reasons. First, buckling generates bending stresses not present in the original configuration. If the stresses in the original (i.e., "unbuckled") configuration were near yield, additional stress could produce failure in the tubing, including permanent plastic deformation called "corkscrewing." Second, buckling causes movement in oil well tubing. That is, buckled tubing (which is coiled) is shorter than straight tubing, and this is an important consideration if the tubing is not fixed. Third, tubing buckling causes the relief of compressive axial loads when the casing surrounding the tubing is fixed.
Previously, models have been developed for analyzing buckling in wells, however, these models suffer from several drawbacks when applied to deviated wells. One drawback with previous models is that tubing bending stress due to buckling will be overestimated for deviated wells. Another drawback with previous models as applied to deviated wells is that they over predict tubing movement. Still another drawback with previous models is that tubing compliance is overestimated, which may greatly underestimate the axial loads able to be withstood by the surrounding casing. It is with respect to these considerations and others that the various embodiments of the present invention have been made.

Methods and computer-readable media for determining design parameters to prevent tubing buckling in deviated wellbores


Safety top balustrade for a car of a machine room-less elevator which moves in a hoistway, on a wall of which the controller of the elevator is secured, said balustrade comprising:—a fixed structure (21) comprising a plurality of vertical uprights (24) fixed at intervals near edge of the car roof (16) and at least two horizontal tubular guard rails (20, 30) fixed at different heights on the uprights, around the periphery of the car roof, except at the place which is in front of the controller (14) when the car is at the level of controller, in order to leave a passage (33) for direct access to the latter,—a mobile structure (34) comprising at least two horizontal bars (36, 38) which are telescopically mounted inside the tubular guard rails, so as to slide between an open position where the bars are inserted within the guard rails, to free said passage towards the controller, and a closed position where the bars are extended out of the guard rails, whereby said passage is obstructed.

In modern elevator installations, the tendency is to reduce as much as possible the ground surface and the height occupied by the installation. One of the solutions found to reach this aim is to eliminate the machine room which, till now, was located either at the top or at the bottom of the hoistway or else in a lateral local of the hoistway, and to secure the control equipment, for instance the controller, on a wall of the hoistway. Nowadays, it is well known to manufacture machines and controllers having a small thickness, which can then be secured in the space comprised between the hoistway and the car.
In the elevators of this kind, a balustrade is generally provided on the roof of the car, in a position somewhat offset from the edge of the roof to prevent any risk of falling into the hoistway when the roof is not at the level of the controller.
When a technician had to intervene on the controller or on the machine to effect maintenance or reparation operations, he has to climb onto the roof, to control the motion of the car and to stop it when the controller is within easy reach. Since the controller protrudes with respect to the wall of the hoistway, it arrives sufficiently near to the car to eliminate any risk of falling in the hoistway.
However, the technician had to work through the bars of the balustrade, or over the balustrade, i.e. at distance from the controller. In this position, certain working operations become rapidly uncomfortable and tiring. Furthermore, since the balustrade must be made of steel to guarantee sufficient resistance, its interposition between the technician and the controller increases the risk of electrical shock during operations made on electrical components.


An all digital control method for motor drivers eliminates physical motor current sensing. The motor and the driver are modeled to estimate the actual current and the estimated current is used to perform motor control. This provides simplified driver circuitry. Driver non-linearity due to driver dead time may be compensated and minimum driver on times are accommodated while providing good waveform fidelity, minimized motor heating and increased motor system damping.

1. Field of the Invention
This invention relates generally to motor control circuitry and, more specifically, to digital circuitry suitable for controlling motor winding currents in servo motor systems.
2. Discussion of the Related Art
Applications in which objects are moved or positioned under computer control, or according to commands produced by any sort of digital processing system, generally use motors coupled to a digital control system to effect that movcment or positioning. Appropriate combinations of digital control signals, driver circuits, and motors can provide highly accurate rotations or rotational velocities so that the motor systems are suitable not only to provide highly accurate positioning but also highly accurate and reproducible velocities. Driver circuits for motor systems receive digital control signals and produce driving signals, typically square waves, to be applied across the windings of the motor. The accuracy of these motor systems is obtained by the driver circuits using feedback from the motor as to the motor position and through the high degree of control of the amplitude and timing of current signals that can be supplied to the windings of the motor. Particularly useful motors for these digitally controlled motion or positioning applications include two or three phase, permanent magnet motors.
An example of a portion of a conventional motor and motor control system is illustrated in FIG. 1. The illustrated motor might, for example, be a two-phase permanent magnet synchronous motor indicated in the figure by a single, isolated winding of the two-phase motor. Although the following background discussion is made in terms of a two-phase motor system, aspects of the present invention are believed to provide advantages when applied to the operation of other types of permanent magnet motors and in particular when applied to three-phase motors. One winding or coil 10 of the motor is indicated in FIG. 1 and is modeled as including an inductance 12 and a resistance 14 in series with the inductor.
The illustrated motor and driving circuit has a configuration generally referred to as an "H-bridge" in which a half-bridge is provided on either end of the winding 10 so that both ends of the coil 10 are driven by a half-bridge. Each half-bridge can drive both positive and negative voltages using an upper switching element 16, 18 and a lower switching element 20, 22. In the illustrative example the switches 16-22 are MOS field effect transistors ("MOSFETs"), although other types of switches including bipolar transistors are sometimes used in the illustrated H-bridge driving circuit. Each of the switches has a diode connected across the terminals of the switch. The catch or commutating diodes 24, 26, 28, 30 provide a parallel current path for the corresponding ones of the switches to catch the inductive spike output from the coil 10 that occurs when one of the switches of the half-bridge opens prior to the opposing switch closing.
One mode of operation that illustrates a function of the catch diodes can be shown beginning with the FIG. 1 H-bridge in a state with switches 16 and 22 switched on so that current flows from right to left through the coil 10. When switch 16 is switched off, the current flowing through the coil starts to decrease, reducing the magnetic flux within the coil. As this begins, the voltage at the junction indicated by 32 in FIG. 1 begins dropping rapidly. When the voltage at junction 32 falls to the point that diode 28 is forward biased, current begins flowing from ground through the catch diode 28, through the motor winding 10, through switch 22, and back to ground. After a period of dead time of the driver circuitry, switch 18 is turned on. The comparatively low on-state voltage of switch 18 in its on state causes the current flowing through the motor winding 10 to flow through the switch 18 and turns the diode 28 off. The current flowing from ground, through the lower half of the bridge (switch 20 or diode 28), through the motor winding 10, back through the lower right half of the driver (switch 22 or diode 30), and back to ground is referred to as "recirculating," since the current flows in a circle. In a recirculating mode of operation, transistors 16 and 18 are switched on while transistors 20 and 22 are off, or the inverse is true. It should be noted that the current does not recirculate indefinitely in these embodiments. The resistance of the driver and winding causes the magnitude of the current to gradually decay, although this is generally slow with respect to the chopping frequency.
There are a variety of different prior art methods for controlling the current through the motor winding 10. Typically these method rely on a measurement of the current passing through the motor winding to provide feedback on the operation of the motor. The measurement of the current through the winding may be made either directly through the winding itself or as the current flows through one or more of the switches (16-22 of FIG. 1). Methods for measuring the current include the use of current sensing resistors, magnetic field sensors, and current transformers at the switching element. For the purposes of illustrating the background of the present invention, the following discussion will emphasize switched mode current control.
Switched mode current controllers include those that use peak-sensing with recirculation, those that use peak sensing without recirculation, and others that use anti-phase methods. The drivers that use peak sensing with recirculation to control the motor current apply the supply voltage to the winding until the sensed winding current exceeds the desired threshold. The winding is then effectively short-circuited until it is time for the next power addition cycle. The next power additional cycle may be initiated following a fixed off time, as is characteristic of a variable chopping frequency drive, or at a fixed repetition rate for a fixed chopping frequency drive. These types of drives are effective for putting power into the motor winding, but arc not effective in removing the power. Further discussion of these drivers and their problems are provided in U.S. Pat. No. 5,710,499 to Carvajal, "Step Motor Control Circuit and Method." As stated in U.S. Pat. No. 5,710,499, drivers that use peak sensing with recirculation current control are known to reduce power output of stepper motors at higher speeds.
Conventional control methods, including the method of U.S. Pat. No. 5,710,499, are also not effective in decclerating loads in which the motor is primarily acting as a generator. It may be desirable to use a stepper motor as a generator to brake and slow the motor, significantly improving the ability of the motor to be stopped.
A further drawback of the fixed frequency recirculating control method is that the method provides very poor control of the motor when the motor winding current is near zero. The minimum on time of the switch circuit divided by the fixed chopping period sets a minimum duty cycle at which the driver may operate, as reflected in Equation 1. The minimum on time may result in significant minimum currents, which in turn may result in large crossover distortion as the current switches from a positive to a negative value within the bridge driving circuit. This in turn may not allow for accurate position or torque control of the motor attached to the control circuit. EQU V.sub.Minimum=V.sub.Supply* T.sub.Minimum/T.sub.cycle (1)
As discussed above, various designs using a recirculation mode of operation have drawbacks which reduce their desirability. The recirculation mode of operation, on the other hand, does minimize the magnetic losses of the motor by minimizing the Root Mean Square (RMS) amplitude of the applied voltage waveform. A low RMS voltage is achieved for the circuit because the winding voltage (i.e., the voltage across the motor winding) is approximately zero volts except for when power is being added to the motor winding. For the same reason, the recirculation modes of operation also limit the ripple current in the motor windings.
Drivers that use a peak sensing, non-recirculating mode of operation apply the power supply voltage to the winding until the desired current level has been exceeded, and then switch off all switches in the bridge, allowing the current to flow through the catch diodes until the following cycle. This mode of operation is capable of rapidly transferring power from the motor windings back to the power supply rail, and of controlling currents near zero, but it still has significant crossover distortion as the current changes from positive to negative within the bridge. The peak-sensing, non-recirculating mode of operation also produces significant motor heating due to the large AC component of the applied winding voltages and the large winding ripple currents, and the peak controlled current is often significantly different from the average current desired within the motor winding.
Yet another type of motor current control is the anti-phase method. The anti-phase method of control switches only between the forward voltage (switches 16, 22 on) and reverse voltage (switches 18, 20 on) during operation. The IXMS-150 manufactured by IXYS Corporation is a good example of a part that operates in this mode. Anti-phase operation provides excellent four-quadrant control of current, delivering power to the motor in a desirable manner and desirably facilitating use of the motor as a generator when decelerating a load. The anti-phase mode of operation exhibits good control of motor winding currents near zero while maintaining fairly low cross over distortion. On the other hand, motors operating in accordance with an anti-phase mode of operation may suffer from high ripple currents and magnetic losses in the motor, which tend to heat the motor. Other disadvantages of the anti-phase mode of operation include the fact that the current control loop must be tuned for the particular motor windings, and the requirement of current sensing.
Of the three control modes discussed, motors operating according to the anti-phase method exhibit the lowest crossover distortion. The driver stage illustrated in FIG. 1 generates a significant cross over distortion due to the dead-times associated with the finite switching times of the switches. The effect will be discussed in the following for a full switching cycle (high to low and back to high) for both possible current directions.
Referring again to FIG. 1, the first analysis is taken with current flowing through the motor winding 10 from left to right, with emphasis on the half bridge consisting of switches 16, 20 and diodes 24, 28 driving the motor winding 10. At the beginning of this analysis, the upper switch 16 is conducting for an active high period. When this period ends, switch 16 is switched off. Current continues to flow left to right through the inductor 12, necessarily flowing up through diode 28, since diode 24 is reverse biased and non-conductive. After the crossover delay, switch 20 begins conduction and diode 28 switches off. After the lower switch 20 has conducted for the commanded low period, it is switched off. With the current flowing from left to right, then diode 28 must begin conducting to carry the current. After the dead time period, the upper switch 16 begins conduction and the lower diode 28 stops conducting. In this case, the low period of the left half-H bridge (16, 20, 24, 28) as seen by the motor winding 10 is extended by the cross over delay beyond the period dictated by the controlling pulse width.
The second analysis with current flowing from right to left will show that the upper diode 24 will conduct during the two dead-time periods, enhancing high period of the output voltage. The direction of the enhancement subtracts from the nominal duty cycle of the driver causing significant crossover distortion. In conventional systems, this distortion may be reduced by use of negative feedback in the current control loop, necessitating current monitoring in conventional motor control systems. In such conventional systems, the feed-forward portion of the control loop does not handle this cross over distortion.
Conventional methods of motor control systems thus suffer from high cost, complexity, and/or heat production caused by the need to measure the current. Conventional methods may further be undesirable in that they do not simultaneously have good four quadrant current control while limiting ripple current and magnetic losses in the motor.

c/o QuickSilver Controls, Inc., 712 Arrow Grande Cir.


The present invention relates to pharmaceutical compositions containing a caffeine salt complex and a pharmaceutically acceptable carrier for use in methods for preventing or treating cancer or solar dermatitis. Methods for inducing apoptosis or inhibiting proliferation in a cancer cell or cell which as UVB-induced DNA damage using a caffeine salt complex or methylated xanthine are also provided.

Over half of all new cancers are skin cancers and its incidence is on the rise due to increased recreational exposure to sunlight and depletion of the ozone layer (American Cancer Society's 2004 Facts & Figures; Nataraj, et al. (1995) Photochem. Photobiol. 62:218-230; McKenzie, et al. (1999) Science 285:1709-1711). While the use of sunscreens has decreased the risk of skin cancers (Stern, et al. (1986) Arch. Dermatol. 122:537-545; Glanz, et al. (2002) Morbid. Mortal. Wkly. Rep. 51:1-18), there is a need to identify additional approaches for skin cancer prevention in individuals previously exposed to high-dose levels of sunlight.
Treatment of SKH-1 hairless mice with ultraviolet B (UVB) (30 mJ/cm2) twice a week for 20 weeks results in mice without tumors but with epidermal hyperplasia and a high risk of developing skin tumors during the next several months in the absence of further UVB treatment (Lou, et al. (1999) Nutr. Cancer 33:146-153). This animal model resembles humans who have received high levels of exposure to sunlight early in life with reduced exposure later in life. UVB-pretreated high-risk mice have been used for evaluating the effects of potential chemopreventive agents on skin tumor formation in the absence of further exposure to UVB. Oral administration of green tea, black tea, or caffeine to UVB-pretreated high-risk mice inhibits tumorigenesis, but the decaffeinated teas have little or no activity, and reconstitution of the decaffeinated teas with caffeine restores biological activity (Lou, et al. (1999) Nutr. Cancer 33:146-153; Lu, et al. (2001) Cancer Res. 61:5002-9; Huang, et al. (1997) Cancer Res. 57:2623-9). Further, oral administration of black tea to UVB-pretreated mice with tumors selectively inhibits the growth of the tumors by inhibiting proliferation and stimulating apoptosis in the tumors without affecting normal non-UVB-treated skin (Lu, et al. (1997) Carcinogenesis 18:2163-2169). Oral administration of green tea or caffeine for two weeks prior to a single irradiation with UVB also enhances UVB-induced increases in epidermal wild-type p53 and apoptosis in the epidermis of SKH-1 mice (Lu, et al. (2000) Cancer Res. 60(17):4785-91). In addition, topical application of caffeine to the skin of SKH-1 mice, immediately after irradiation with UVB, decreases the number of nonmalignant and malignant skin tumors (Lu, et al. (2002) Proc. Natl. Acad. Sci. USA 99:12455-60) and enhances apoptosis as evidenced by increases in caspase 3 (active form)-immunoreactive-positive cells and caspase 3 enzyme activity in the epidermis (Lu, et al. (2002) Oncol. Res. 13:61-70). Similarly, local application of caffeine and theophylline to Swiss (Carshalton) mice reduces the incidence of skin cancer induced by repeated irradiation with UV light (Zajdela and Latarjet (1978) Natl. Cancer Inst. Monogr. (50):133-40).
U.S. Pat. No. 6,642,274 further teaches that caffeine and other methylated xanthines are useful in the prevention and treatment of prostate disorders including benign prostatic hypertrophy and carcinoma of the prostate.
Moreover, U.S. Pat. No. 6,316,435 teaches methods and kits for treating lymphoproliferative diseases in a host including administering to a host pentostatin, at least one alkylating agent and at least one methylated xanthine.

Caffeine salt complexes and methods for using the same in the prevention or treatment of cancer


Roofing panels with water shedding features may be installed on the roof of a house or other structure in lieu of or as an underlayment for traditional roofing materials. The water shedding features can be built into a base of the roofing panels, as part of a frame for the roofing panels, or formed as part of a waterproofing layer applied to the base of the roofing panels, or which can be configured as a roofing panel. The roofing panels also can be installed in overlapping courses along a roof with water shedding features applied thereto or incorporated along one or more peripheral edges. The water shedding features of adjacent roofing panels will collect and divert water away from the upper surfaces and/or away from headlap and/or sidelap joints defined between the roofing panels.

The application of structural roofing panels to the roof of a building has long been a construction practice, particularly in commercial roofing. More recently, interest in applying this construction practice to sloped residential roofs has grown. Issues with traditional roofing panels include the fact that they must be sealed along the junctions of individual panels after application. This can be done in a variety of ways including, for example, applying a roofing membrane over the panels, taping the junctions of the panels, applying a traditional shingled roof over the panels, and combinations thereof. All of these sealing options are labor intensive and subject to human error and deterioration over time.
A need exists for roofing panels for sloped roofs that, upon installation, collect and/or shed water without the need for ancillary sealing or roofing strategies, and/or which can incorporate design features that inherently provide effective water shedding at critical panel junctions while being easily installable on a roof deck. It is to the provision of such roofing panels that the present disclosure is primarily directed.