A loudspeaker system containing wave-shaping sound chambers with approximately rectangular inlets and outlets of substantially the same size that are used to flatten or control the curvature of the acoustic wavefronts contained within system waveguides. Control of the degree of curvature of the wavefront enables the development of a wide variety of multi-waveguide arrays. The sound chambers are placed between a waveguides and a flattened conical horns of secondary waveguides. The sound chambers transform the curvature of the typical fan shaped wavefront that results from a conical horn throat into a wavefront that approximates a planar or curved rectangular ribbon of sound.

1. Field of the Invention
This invention is generally directed to audio loudspeaker systems and more particularly to such systems, which incorporate sound chambers which transform fan shaped wavefronts issuing from primary waveguides into rectangular planar or curved wavefronts which are directed to sound disseminating secondary waveguides.
2. Description of the Related Art
Large sound systems contain multiple transducers operating in the same frequency band in order to achieve the required sound pressure level (SPL) and the required acoustical coverage of its intended target. The highest efficiency sound systems use the principle of horn loading to achieve maximum SPL. The horn and its associated driver have two particular characteristics of interest: the driver is by definition larger than the throat of the horn; and wavefronts are radiated in a generally spherical shape. The dimensional limit dictates that an array of such devices cannot be constructed so that the horn throats are in close proximity to one another; the throats are displaced by the size of the attached driver. The result of any multi-element combination is that of an array that generates multiple spherical sound waves with significant interference effects. The problems of the resulting multiple source array are well documented in the literature.
Significant effort has been invested by numerous practitioners of the audio arts to find solutions to this problem. The result has been great improvement in the understanding of the principle of horns and better control of the directional characteristics of such devices. D. B. Keele, Jr. has shown many ways to modify the directivity of horns through the use of flat sided conical growth sections combined with arbitrary adjustments to the walls of horns, xe2x80x9cWhat""s So Sacred about Exponential Horns?xe2x80x9d, D. B. Keele, Jr., Presented at the 51st Convention of the Audio Engineering Society, Los Angeles, May 1975, Preprint 1038. These horns became known as xe2x80x9cconstant directivity hornsxe2x80x9d. None of the improvements of individual horns has resulted in an array of horns that eliminates the interference effects found in multi-source arrays.
This work was continued by Clifford A. Hendricksen and Mark S. Ureda with the goal of improved vertical directivity, xe2x80x9cThe Manta-Ray Hornsxe2x80x9d, Clifford A. Hendricksen and Mark S. Ureda, Presented at the 58th Convention of the Audio Engineering Society, New York, November 1977, Revised June 1978. This was achieved through a vertically oriented, conical throat section and a constant angle between the top and bottom wall of the horn over most of its length. These horns were referred to as xe2x80x9cconstant directivityxe2x80x9d and xe2x80x9cManta-Rayxe2x80x9dhorns.
Early Line Arrays
The line array results from a different approach to the problem of interference, H. F. Olson, Acoustical Engineering, (Van Nostrand, Princeton, N.J. 1957). In its simplest form, it is a row of closely spaced direct radiators operating in the same frequency band and is dependant on mutual coupling of one driver to the next. Drivers are said to be mutually coupled when they are placed within one wavelength of each other. The benefit of mutual coupling is that drivers operating under such conditions radiate their combined acoustical energy nearly as though they were a single transducer.
Until recently, line arrays have consisted of multiple small direct radiating transducers arranged in a vertical row. Typically the drivers are chosen to be sufficiently small to allow mutual coupling to the highest frequency of concern. For example four inch diameter drivers permit coupling to above 3 Khz, which is sufficient to allow good speech intelligibility. This approach yields a system with a controlled vertical coverage and correspondingly wide horizontal coverage but with at least two significant limitations. Such arrays of direct radiators are low in efficiency and the method does not work for typical horn loaded high frequency drivers because the wavelengths at the highest audio frequencies are generally a factor of ten shorter than the dimensions of the drivers used thus preventing mutual coupling. Furthermore, the use of small direct radiators severely restricts the operating bandwidth.
Waveguides with Linear Inlet Apertures
In October 1987 in New York City, Dr. Earl Geddes introduced the concept of an xe2x80x9cAcoustic Waveguidexe2x80x9d, through the publication and presentation of a historically important technical paper at the 83rd Audio Engineering Society Convention. Many waveguides are described in the text of the paper with varying degrees of usefulness in the audio world. The publication is titled xe2x80x9cAcoustic Waveguide Theoryxe2x80x9d. The importance of this paper is that it prescribed and consolidated a new approach to the analysis of the boundary of the sound wave as it moves along the length of a horn. Specifically, it is noted that for any horn type device to be considered a true waveguide, it must meet the criteria that the wavefront will always intersect the boundary of the waveguide at a 90 degree angle. If this condition is not met, the wavefront cannot maintain contact with the wall of the horn and it thus should not be considered a waveguide. The reason for this is both obvious and simple. The particle motion in any wave is always in the direction of the travel of the wave and normal to the wavefront. Any boundary not normal to the wavefront will cause a reflection of energy, thus reducing contact with the waveguide wall.
The importance Geddes"" work is emphasized by its selection from hundreds of papers for publication in the permanent record of the Journal of the Audio Engineering Society, two years later. (Preprint Number: 2547 Convention: 83 1987-10 AES Journal Vol:Issue: 37:7/8 Page: 555 Year: 1989). Three of the waveguides presented are of pivotal interest in the construction of a new type of line array because their throats approximate the shape of a narrow ribbon, either straight or curved. A characteristic of these waveguides is that they can be joined in an obvious manner to produce a waveguide of extended length. These three are derived from the coordinate systems after which they are named. The cylindrical waveguide is shown in FIGS. 6a-6c, the elliptic cylindrical waveguide is shown in FIGS. 5a-5c and the prolate spheroidal waveguide is shown in FIGS. 7a-7c.
A cylindrical waveguide can be configured of infinite length. A waveguide comprised of a number of segments of cylindrical waveguides joined at 90 degrees from the angle theta can also be of infinite length and results in an entrance or throat that is shaped as an extended rectangular slot. From Geddes we know that the height at the mouth must be the same as the height at the throat (i.e. that the two boundary surfaces are parallel) and that the wave is spread out only in the theta direction shown at FIGS. 5a, 6a and 7a. Geddes comments that all that remains to make this type of waveguide useful is the development of the necessary xe2x80x9cphasing plugxe2x80x9d to shape a sound wave to match the throat requirements of the waveguide.
The wavefront required to correctly propagate a cylindrical wave to the throat of the waveguide is cylindrical, (curved in the theta direction) and of the correct radius in order to propagate one parameter waves within the waveguide. Any wavefront other than a cylindrical wave of the correct radius will propagate down the waveguide through reflection and higher order modes that are quite undesirable according to Geddes. The compromise of the cylindrical waveguide is used in practice because it is extremely simple to fabricate since all waveguide surfaces are planar.
Geddes also discloses a waveguide suitable for use with a planar rectangular sound source. The elliptical cylindrical waveguide requires a planar wave of rectangular cross section at the throat. This waveguide can also be extended infinitely since two surfaces are parallel in the same manner as the cylindrical waveguide. At this time there is no evidence of any such waveguide in commercial production.
The prolate spheroidal waveguide approximates a section of a cylinder at the throat. This waveguide will exhibit good acoustical behavior if there is a limited growth in the theta direction. The side of this waveguide is a planar surface that is oriented radially from the apex of the waveguide. No two surfaces of the waveguide are parallel so an array of these waveguides cannot be infinite, but must have a finite radius and be thus limited. Several waveguides oriented in an arc will effectively form a single waveguide with a continuous throat approximating a curved ribbon. The prolate spheroidal waveguide was not developed further in this paper.
The First Wavefront Shaping Sound Chamber
In 1972 JBL of California introduced the 2405 high frequency transducer designed by Locanthi. The device controlled vertical directivity by producing a flat wavefront from a vertical slot. This was achieved by enclosing an inner body of circular cross section with flattened sides within an outer shell, thus forming an acoustic conduit with an inlet aperture that is adapted to the transducer and an outlet aperture that is planar and rectangular. The path lengths as measured from the diaphragm to the outlet aperture are practically identical. The wavefront that emerges is rectangular and planar. This sound chamber is suitable for use with some of Geddes"" waveguides.
New Line Arrays
The mathematical model for the cylindrical waveguide is evident in a commercial loudspeaker system sold under the trade name of xe2x80x9cV-DOSCxe2x80x9d produced by L-Acoustics of France. The wavefront emerging from this waveguide is said to be cylindrical. The required phasing plug mentioned by Geddes has been developed by Heil and is disclosed by Christian Heil in U.S. Pat. No. 5,163,167 and in French Patent 2,627,886. It takes the shape of a sound chamber capable of transforming the circular planar wavefront at the exit of a high frequency compression driver into a rectangular planar isophase wavefront suitable for use with the elliptical cylindrical waveguide. The device disclosed by Heil produces, according to its author, a planar wavefront that does not meet the requirement of a cylindrical waveguide.
Adamson discloses waveguides in U.S. Pat. No. 5,900,593 that are modified from the prolate spheroidal type of waveguide to create a throat that approximates a curved slot and is wide enough to accommodate the requirements of particular sound chambers. Adamson also discloses sound chambers capable of transforming a planar circular wavefront into that of a section of a cylinder or a curved ribbon. The wavefront emerging from this type of waveguide is like the outer surface of a torus, i.e. the outer surface of a donut, or a bent tube.
In both the Heil and the Adamson sound chambers, when the wavefront is considered in two orthonormal planes it can be seen that the wavefront is forced to expand in one plane and not in the other. In the plane taken as a section in the axial direction across the smaller dimension of the sound chamber, the dimension the passageways within does not expand. However, in the axial plane orthonormal to the first plane considered, the expansion of the sound chamber is large. This is necessary so that the rectangular ribbon of sound thus created is equal to or greater than the outside dimension of the audio transducer that energizes the sound chamber. This method allows the formation of a continuous sound source notwithstanding the dimension of the transducer.
A very important limitation of the Adamson and the Heil devices is that there is significant required boundary divergence in order to achieve the required length at the exit aperture. In the half of the sound chamber closest to the inlet, the sound wave propagates with an expanding annular shaped wavefront. As the wavefront nears the exit of the sound chamber, the wavefront shape changes toward its target shape, that of a planar rectangle.
It is a well documented fact that a planar wave cannot propagate in an enclosed space unless the boundaries of the space are parallel. As the wave nears the exit, the diverging upper and lower walls of these sound chambers cause significant reflections. The disturbance in the wavefront caused by these reflections results in a chaotic behavior above 8 Khz. This behavior is in particular apparent over nearly 30% of the total area of the exit. This results in an obvious and measurable deterioration in the summation of the wavefronts of adjacent sound chambers, particularly at the highest frequencies.
The present invention is embodied in a plurality of loudspeakers arranged in a horizontal or vertical array, where each loudspeaker is comprised of at least one high frequency compression driver, at least one primary waveguide and at least one wave-shaping sound chamber and at least one secondary waveguide. In the preferred embodiment of present invention, the primary waveguide takes the approximate form of a constant directivity horn throat that can be characterized as a hollow wedge shaped acoustic conduit, wherein the inlet aperture is so shaped to be affixed to the outlet of an acoustic transducer. The outlet aperture is substantially rectangular and so shaped to be affixed to the wave-shaping sound chamber and the sides of the primary waveguide are substantially straight. There are other forms of horn throat that will result in a different distribution of sound in the horn throat.
In the present invention a high frequency compression driver affixed to the primary waveguide generates an acoustic wavefront that changes shape from a circular planar wave to that of a curved ribbon as it expands along the length of the primary waveguide. The sound waves are permitted to follow their natural behavior by expanding unimpeded as a fan shaped wave. This allows the wave to expand while maintaining a 90 degree angle between the wavefront and the side wall of the horn throat. A sound wave originating from the sound source will propagate along the length of the conduit in the form of an arc shape, the angle of which will be proportional to the included angle of the side walls of the primary waveguide. The horn throat is terminated at a point where the straight line dimension of the arc from end to end is approximately equal to the desired total length of the required wavefront. The resulting outlet aperture is rectangular.
The wavefront shaping sound chamber is so formed that its inlet aperture matches the shape of the outlet aperture of the horn throat. The outlet aperture of the sound chamber is similar in size and shape to the inlet aperture. The sound chamber is comprised of two outer shells halves that define the inlet and outlet aperture and form an inner cavity having opposing inner surfaces. Contained within the inner cavity is an inner body that has an outer surface that together with the inner surfaces defines at least one passageway that connects the inlet aperture to the outlet aperture. The sound chamber is so formed to provide means to attach the inlet aperture of the sound chamber to the outlet aperture of the primary waveguide and to provide means to attach its outlet aperture to the inlet aperture of the secondary waveguide.
An alternate embodiment of the present invention is to form the outer shell of the sound chamber and the primary waveguide as one inseparable unit or the sound chamber and primary and secondary waveguides as a single unit.
The inner surface of the outer shells and the outer surface of the inner body are so formed that the passageway permits a plurality of acoustic paths from the inlet aperture to the outlet aperture. The inner surfaces of the outer shell and the outer surface of the inner body are so formed that the plurality of acoustic paths that connect the inlet aperture to the outlet aperture are unequal in length.
The primary means of controlling the path lengths through the sound chamber is to increase the thickness of the inner body and to correspondingly increase the outer shell so that the portion of the sound wave that encounters this sectional shape must travel further than that portion of the sound wave that encounters a thinner shaped section of the inner body.
The sound wave that arrives at the inlet aperture is arc shaped and so the mid point of the arc is advanced to the furthest point of the horn throat and thus arrives at an earlier time than the sound at the edge of the wavefront. At each point across the width of the inlet aperture of the wave shaping sound chamber, the wavefront arrives at a different time. A different section of inner body and outer shell is thus shaped and presented to the incoming sound wave at each point where a different path length is required.
The plurality of paths that extend through the sound chamber may be so shaped that the length of the paths causes the advanced portions of the wave to take a correspondingly longer path through the sound chamber corresponding to the difference between the shape of the incoming wavefront and the required outlet wavefront. The result is that the wavefront emerges with the curvature of the wavefront reduced or completely flattened.
Since the curvature of the wavefront in the horn throat is independent of the degree of path length difference across the width of the sound chamber, any amount of curvature is achievable. For example, the path lengths through the sound chamber could be increased at the ends of the aperture and made shorter in the middle with the result that the curvature of the wavefront would be increased.
A concave wavefront can also be created by increasing the path lengths through the mid portion sound chamber to a greater degree than that required to flatten the wavefront.
A further aspect of the present invention is that nearly all the energy contained in the arc shaped wavefront that arrives at the inlet of the wave-shaping sound chamber is diverging from the center axis of said chamber. Since the particle motion in the curved wave is normal to the wavefront, only the particle motion in the exact center of the wavefront in moving in the axial direction of the device. Since the wavefront will emerge from the waveshaping sound chamber with a different radius or as a planar wavefront, it is necessary to re-direct the particle movement in the wavefront.
It is a function of the present invention to provide means to redirect the energy in the wavefront by means of dividing the plurality of paths within the sound chamber with vanes that extend from the inlet aperture to the outlet aperture, oriented normal to the wavefront and radially from the apex of the arc of the exit wavefront. The space between the vanes must be less than or equal to one wavelength of the highest frequency that will be properly transmitted by the sound chamber. This dimensional constraint will insure that no energy can be reflected laterally between the vanes.
With the vanes correctly oriented in the entrance of the sound chamber, the expanding arc shaped wavefront will enter between the vanes without reflection from the substantially parallel end walls of the sound chamber. The resulting variety of wavefronts that can be created by this method meet the requirements for certain useful waveguides. In particular, the prolate spheroidal, the elliptical cylindrical and to a lesser degree, the cylindrical waveguides (after Geddes) may be fixed to the outlet aperture to form a complete sound transmission device.
This type of structure may be combined with the co-entrant mid device described in Adamson patent application Ser. No. 09/359,766 of July 1999 or may be applied in the manner of the V-DOSC system of Heil.
In the present invention there are no differences in principle or geometry between a horizontal array and a vertical array. The horizontal array is a simple 90 degree transformation of the vertical array and vice versa. Depending on the desired application, various embodiments may be constructed and oriented in any desired angle to suit the desired application.
It is an object of the present invention is to provide means to modify the curvature of an entire acoustic wavefront emanating from a typical horn throat and to provide a suitable outlet aperture and a wavefront of a suitable degree of flatness to satisfy the requirements of all possible waveguides that have throats characterized by an extended slot.
It is a further object of the present invention to provide a method that allows more than one transducer operating in the same frequency range to produce a common wavefront with virtually zero acoustical interference.


The contacts of an electrical connector are joined by the biasing force of the contact elements and in practice are separated by a probe to interconnect therebetween an additional circuit member. A probe which has a terminal end with an oblique surface to cause the wiping of the contact elements against each other at the interface during insertion or removal will improve contact and extend the life of the contact elements.

1. Field of the Invention
Present invention relates to a terminal end for a probe used to interrupt a circuit, introduce a parallel or series circuit; as used on an overload protector, a test access device, a patch cord or other electronic device; between pairs of contact elements, particularly in a telecommunication cross connect block and in one aspect to a terminal end affording the separation and remating of spring biased contact elements to cause the same to wipe against each other upon insertion and removal of the probe.
2. Description of the Prior Art
Termination and distribution connectors have been in use in the communications industry for a long time to afford rapid connection of distribution wires to a pair of wires of an incoming or outgoing cable. The systems are built for use with pairs of wires. Wire pairs are joined to at least one other pair to perfect the transmission. Also, it is very necessary that the splice between one pair and the other pair be readily accessible to disconnect, change or rearrange the connections and also to make series connections to the wire pairs for purposes of testing, protecting or otherwise monitoring each pair of lines. Therefore, the connections between the pairs of wires utilize contact members making electrical contact with each wire and then with themselves such that a pair of contacts join each pair of wires.
The support for the contacts afford the suitable support for incoming wires and the ready connection of outgoing or cross connect wires as illustrated in U.S. Pat. No. 4,789,354, assigned to the assignee of this invention. This patent illustrates contacts having a first leg formed with a U-shaped contact element to make an insulation displacing electrical connection to a conductor of a wire and a resilient spring contact. One form of the mating contact elements, formed of appropriate conductive resilient spring-type material, provides a current path that can be broken by the separation of the two spring contact elements which are normally in contact between the pairs of U-slot spring reserve insulation displacing contacts. A second form maintains a current path between the U-slot spring reserve contacts but allows a probe to be inserted between a pair of spring contacts. Contacts which perform the same function, i.e., parallel or series contact with a probe, are also illustrated in U.S. Letters Pat. No. 4,283,103. The differences are not in functions but in the construction of the contact elements and their relationship to the connector support structure.
It is the object of the present invention to provide such probe devices with terminal ends according to this invention which have the feature of causing a wiping action between the spring contacts when the probe is inserted between, or removed from between the pairs of spring contacts and one which will permit the probe to be inserted into the line without interruption of the normal splice between the contacts between the conductors until a second connection has been made.
The probe may have a circuit on the body, or the body may have the form of a printed circuit board such that the ultimate connection between the contacts and the body of the probe may be adapted to connect to the connected wire pairs in either parallel or series arrangement, but every connection or disconnection will result in the wiping of the opposed spring contact elements at the contact surface therebetween.
The construction and features of the present invention will be further described herein.

Tip for forcing contacts to wipe against each other

Minnesota Mining and Manufacturing Company


A shower dryer system includes a dryer tower with nozzles for directing heated air into a shower enclosure interior. A programmed controller controls the rate of air flow and the temperature of air flow to and through the air nozzles.

It is known to provide arrangements for drying and heating shower stalls before taking a shower. Such devices are also employed by a user who would like to be able to dry himself of herself after the shower.
The typical prior art arrangement allows air to come in from the wall or from a duct on top of the shower. Such arrangements do not do an effective job and they are quite costly to install. Furthermore, maintenance of wall mounted and ceiling mounted installations is difficult and costly.
It is also known to direct heated air toward a person in a shower or other confined space to facilitate drying. Some of these devices have a tower-like configuration and define heated air exits (slots or holes) along the lengths thereof.
The following patent publications are believed to be representative of the current state of the prior art in this field: U.S. Pat. No. 5,099,587, issued Mar. 31, 1992, U.S. Pat. No. 4,733,421, issued Mar. 29, 1988, U.S. Pat. No. 4,558,526, issued Dec. 17, 1985, U.S. Pat. No. 3,128,161, issued Apr. 7, 1964, U.S. Pat. No. 4,685,222, issued Aug. 11, 1987, U.S. Pat. No. 5,377,424, issued Jan. 3, 1995, U.S. Pat. No. 3,878,621, issued Apr. 22, 1975, U.S. Pat. No. 4,780,595, issued Oct. 25, 1988, U.S. Pat. No. 4,857,705, issued Aug. 15, 1989, U.S. Pat. No. 5,873,179, issued Feb. 23, 1999 and European Patent Application No. 9230221301.
The invention disclosed and claimed herein differs from the prior art in a number of respects, differences which contribute to the improved operation and ease of maintenance of the system.


A flame-resistant cover film for flexible circuit boards having excellent flame-resistance, handling, and storage qualities may be produced by treating an insulating film of a nonwoven polymer fabric with a flame-resistant, halogen-free polymeric adhesive. The polymeric adhesive comprises an aqueous mixture of a copolymerizate of acrylic acid esters and styrene, and an aminoplastic or phenoplastic precondensate to which a mixture of fine-particle red phosphorus and fine-particle ammonium polyphosphate is also added.

Flexible printed circuits have gained widespread use in applications where flexing is a functional requirement, such as where flexing facilitates assembly and disassembly, or other dimensional variations need to be accommodated. In general, flexible circuits are formed by bonding a metal foil, such as a copper foil, onto a flexible insulating film or substrate such as a polyester resin film. A circuit is formed in the metal foil by conventional etching techniques.
Flexible printed circuits may be covered with an additional layer of a similar insulating film or substrate to provide additional insulation and to protect the circuit pattern from contamination, corrosion, and mechanical damage. The cover film may also be necessary for the formation of a symmetrical layered structure and/or a solder stop mask.
Conventional cover films may be made of polyester or polyimide polymers. Holes may be introduced into the film so that solder "eyes" to the flexible circuit boards remain clear. The cover film may be bonded to the flexible circuit board with a heat-activated adhesive coating under pressure and heat.
A disadvantage of using a heat-activated adhesive to effect such bonding is that such adhesives flow when subjected to pressure and heat. Thus, any holes that have been introduced into the cover film may be occluded by the flowing adhesive, reducing the available solder surface beneath them. The extent of adhesive flow is difficult to control, since it depends, among other things, its degree of polymerization and the proportion of volatile components in the adhesive.
One approach to control the problem of flowing adhesives has been to employ a non-flowing adhesive. However, this method is also associated with its own problems. For example, the non-flowing adhesive can trap air that cannot be completely displaced. The trapped air leaves voids that may permit solder to migrate below the cover film during hot-tinning or soldering.
Another problem associated with flexible printed circuit boards is that heat generated by a current flowing through a circuit can cause the substrate, the insulating film, or the adhesive, to be ignited. Thus, flexible printed circuit boards have a potential to cause fire in instruments and devices utilizing such circuit boards. A proposed solution to this problem is to include flame retardants in the cover film adhesive.
U.S. Pat. No. 4,075,420 is directed to a cover layer for flexible circuit boards. The disclosed cover layer is formed by a three-layer laminate, which includes an insulation film layer, a thermosetting adhesive layer and a phenolic resin layer. The phenolic resin layer connects the cover film to a flexible circuit board.
U.S. Pat. No. 4,311,749 is directed to a flame-proof flexible printed circuit board which includes a flexible resin film and a copper foil electric circuit, bonded together with an adhesive. The flexible resin film is treated to provide a surface tension of 36 dyne/cm, or more, and a resin film containing a flame retardant is applied to the treated surface of the flexible resin film.

Flame-resistant cover film for flexible circuit boards


Assembly line balancer groups tasks of multi-sided, mixed model assembly lines on the basis of per side and per model constraints. Resulting compound tasks involve less computational time and power in balancing the line.

1. Field of the Invention
This invention relates to serial manufacturing operation, and more specifically relates to a method of balancing a serial assembly line.
2. Description of the Related Art
Certain types of manufacturing operations are normally organized into what are commonly referred to as assembly lines, manufacturing lines, or production lines. In this discussion, they will be referred to as assembly lines. Assembly lines operate as follows: Materials and parts that go into the final product are introduced to the line. Various manufacturing operations, inspections, tests, and/or handling operations are performed at workstations along the line in a serial manner. The result of these steps is the emergence of the final product at the end of the line.
A classic example of a progressive assembly line is that of an automobile assembly line. In this example the chassis, for instance, of the automobile to be assembled is conveyed along the line, passing the various operators at their workstations as it moves along. As the chassis passes a given workstation, the operator performs his given task, which may be, for example, to attach a fender to the chassis. This task is repeated for each chassis which is conveyed past the operator. Note that the operator performs only this task, and performs it on every chassis that goes past him. In modern assembly plants, the operator may be an automated machine or robot which performs the task on a repetitive basis. The line is designed such that the chassis is conveyed past the operator at such a speed that the operator has adequate time to perform his task properly. Equally important is the criterion that the chassis not be conveyed so slowly that the operator has excessive periods of idle time between operations.
Several terms must be defined in the context of this discussion. Although these terms have general meanings, their definition is more narrowly construed as presented herein. In this discussion the term task is defined as a minimum rational work element, i.e. an indivisible element of work, or a natural work element. A task may actually consist of several distinct actions, however further dividing the actions would cause unnecessary work in the form of extra handling. As an example, attaching a fender to an auto chassis could involve the actions of positioning the fender, fetching retaining bolts from a storage bin, placing the retaining bolts in the appropriate holes, fetching a tool to drive the bolts home, and finally driving the bolts home. Although this task as described consists of several distinct actions, to divide the task between operators would involve a great deal of unnecessary coordination between the two, and probable repetition of effort, hence the actions are grouped as an indivisible task. Task time is defined as the amount of time it takes to complete the task.
A workstation is a physical location at which a process, operation, test or inspection is performed or carried out on the in-process product. The workstation may be the location of a specific machine, a group of machines, or an operator and a machine. One task, or a plurality of tasks can be performed at a workstation. Generally each workstation requires one operator. However, in some cases, a single operator can operate several workstations, if time and physical constraints allow it. Conversely, in some cases (such as heavy machinery manufacture or aircraft assembly lines) several operators may be required to man a single workstation.
Another important term is the assembly line cycle time. The cycle time is a function of the line speed, and is the elapsed time between successive units moving along the assembly line. Another way of expressing this is that the cycle time is the amount of time the product is available at each workstation.
Delay time is a concept which is the result of uneven distribution of task times for the various workstations. To illustrate, consider a hypothetical assembly line consisting of four workstations, specified as W1, W2, W3, and W4, at each of which one task is performed, specified as T1, T2, T3, and T4 respectively. The cycle time for this line is ten seconds, meaning the product is available for processing at each station for ten seconds. Assume it takes ten seconds to perform T1, four seconds to perform T2, seven seconds to perform T3, and ten seconds to perform T4. The total time for a product to complete the assembly line is forty seconds (four stations times a ten second cycle time). The total of the actual task times, however, is thirty-one seconds. In this case, the delay time, is the difference between the total time for the product to complete the assembly line, and the total time required for the actual processing of the product while on the assembly line.
Delay time is often expressed as a percentage, and expressed as balance delay. To do so, the sum of the task times (thirty-one seconds) is subtracted from the total available line time (forty seconds); the result is divided by the total available line time, and multiplied by 100. In this case the balance delay time equals 22.5 percent. In other words, during 22.5 percent of the time that the product is moving along the assembly line, the operator(s) are idle and non-productive. If each task time was ten seconds, and the cycle time remained ten seconds, then the balance delay would be zero, meaning each operator is operating at full capacity, with no idle time. This is, of course, an ideal case, which is seldom achieved in actual practice.
If the above example were modified slightly by changing the task time of task 3 (T3) to six seconds, from seven seconds, an example of assembly line balancing can be demonstrated. In this new instance, the total task time is thirty seconds, the total line time is unchanged at forty seconds, and the balance delay is equal to twenty-five percent. However, note that T2 and T3 can be grouped together at one workstation, without violating the need to stay below the cycle time. Now, there are three workstations, specified as W1, W2, and W4. T1 is still assigned to W1 and the total task time for W1 is ten seconds (as before). T4 is still assigned to W4, with a total task time for W4 of ten seconds. W2 now contains tasks T2 and T3, with a total task time of ten seconds for the workstation. In this case the balance delay has been reduced to zero, from twenty-five percent, by combining two tasks to one workstation. Note that as originally expressed, this assembly line could not have been optimized in this way. In the first situation combining T2 and T3 would have resulted in a workstation with a cumulative task time of eleven seconds, which would have violated the cycle time available. In real terms, this means the operator of workstation W2 would have had ten seconds in which to accomplish eleven seconds worth of tasks, which is not possible. However, when T2's and T3's cumulative task time is below the cycle time, combining the tasks results in one less operator/workstation required, and in less idle time.
In a very simplified way, the above discussion provides the motivation and the methodology for assembly line balancing. As shown, the goal of assembly line balancing is to optimize the performance and production of an assembly line. This is done by `balancing` the various workstations such that: 1) each workstation has that number of tasks which leads to a minimum of idle time due to an imbalance of the total task times among the various workstations; and 2) the variation in cumulative task times due to the distribution of the tasks among the workstations is minimized. As shown, assembly line balancing can result in the need for fewer operators or workstations without a decrease in the production rate. Alternatively, assembly line balancing can be used to derive a shorter cycle time (and hence an increased production rate) without adding operators or workstations. Often a combination of shorter cycle time and reduced workstations is the desired goal.
Assembly line balancing is often explained in terms of a packing analogy, that is the balancing problem is analogous to that of packing a given number of equally sized boxes with blocks of varying sizes. The boxes represent the set of workstation cycle times, and the blocks of varying sizes represent the varying task times of the assembly line. The goal is to pack the boxes as fully as possible with the blocks so as to minimize the empty space left over (which corresponds to idle time).
Some blocks have restrictions on what box they can go into, and where in the box they must go (precedence constraints). However, most blocks can be placed wherever they will fit most efficiently. The are three factors which can impact the degree of difficulty experienced and the degree of optimization which can be achieved. These are: 1) the distribution of the sizes of the blocks; that is the ratio of large blocks to small blocks, and how large the large blocks are. Generally, the more large blocks there are, the more difficult the packing problem becomes. 2) The size of the blocks compared to the size of the boxes. Relatively small blocks would be easier to pack than blocks which are large, relative to the size of the box. There is a restriction, however, that no block can be larger than a box. 3) The number of blocks which have some restriction as to where they can be placed. Naturally, the more blocks which have such restrictions, the more difficult the packing problem becomes.
The best solution to such a problem is to start with the restricted blocks first by placing them where they must go. In this way, there is no worry about coming across them later when their required space may already be filled. Next, the larger blocks are placed in the boxes, before the available large spaces are inefficiently wasted by filling them with smaller boxes. Gradually, smaller and smaller blocks are dealt with as the larger blocks are placed, until finally the small gaps and voids left in the boxes can be filled in with the remaining small blocks. Visualizing the assembly line process in this physical manner aids in understanding the concepts and the rationale for the techniques employed.


The invention relates to a diaphragm pump with a device for controlling the position of a diaphragm separating the conveying chamber from the displacement chamber. As a replacement of the mechanical control of the refilling process, a pressure sensor is arranged in the displacement chamber, which is connected with an evaluation unit designed for generating a refill signal, which is switched so it actuates a refill valve through an operative connection. Advantageously, a second sensor for detecting the piston travel is provided, whose signal is linked with the signal from the pressure sensor. The invention furthermore relates to a method for controlling the position of a diaphragm.

The invention relates to a diaphragm pump with a device for controlling the position of a diaphragm, which separates a conveying chamber from a displacement chamber, and with a reservoir for the hydraulic medium, which is in connection with the displacement chamber viva refilling unit.
The invention moreover relates to a method for controlling a diaphragm, which separates the conveying chamber from the displacement chamber of a diaphragm pump and which is driven by an oscillating displacer by means of a hydraulic medium, wherein the displacement chamber is resupplied with hydraulic medium via a line as needed.
Pumps of this type are known in the form of a piston diaphragm pump-from EP A1 0 085 725. The piston diaphragm pump has a displacement piston, which is oscillatingly moved back and forth in a displacement chamber, which is completely filled with a hydraulic medium. Because of this, the diaphragm arranged between the conveying chamber and the displacement chamber performs a diaphragm stroke, which corresponds to the volume of the piston stroke.
During the intake stroke, the fluid to be conveyed flows into the conveying chamber via the inlet valve, and is expelled via the head valve during the pressure stroke.
In most cases, a support plate, which can be displaced over a limited range, is provided in the displacement chamber and protects the diaphragm against an excessive deflection toward the end of the intake stroke.
If, after a defined period of operation, the inevitably occurring losses of hydraulic medium lead to the diaphragm position at the end of the intake stroke being slowly displaced toward the displacement chamber, the diaphragm arrives at the support plate or at a plunger, which senses the diaphragm position. The support plate or the plunger are displaced by the diaphragm against the pressure of springs in the direction toward the displacement work chamber. The plunger, which senses the diaphragm position directly, or the support plate, mechanically unblock a refilling valve in the process, which is opened because of the underpressure prevailing in the displacement work chamber and permits hydraulic medium to flow from a reservoir into the displacement work chamber. In the course of this, the diaphragm and the support plate again move under the pressure of the springs in the direction toward the conveying chamber. During the course of this movement the closure device of the refilling valve also slides again in the direction toward the conveying chamber and closes the refilling valve.
An impairment of the conveying properties of the diaphragm pump can arise as a result of the expulsion of air originally dissolved in the hydraulic medium. In such cases it is necessary to permit a volume to escape from the displacement chamber. A so-called venting valve is provided for this purpose, which makes possible the escape of excess amounts of hydraulic medium or released air. In the course of the initial operation of a diaphragm pump, or of a change of the set stroke length of the connected pump operating unit, the venting valve is simultaneously used to remove excess amounts of hydraulic medium from the displacement chamber in order to assure the function of the mechanical refilling device.
Such a venting valve is known, for example, from the company publication xe2x80x9cAREXxe2x80x9d of Applicant.
The direct determination of the limit positions of the diaphragm by means of an electronic sensor as a replacement for the mechanical determination of the instantaneous diaphragm location has been proposed in EP B1 0 607 308. The electronic signal of the position sensor is compared with a predetermined maximum value in a control unit. In case the maximum value is exceeded, a signal for opening a refilling valve is generated, which prevents an overload of the diaphragm. The disadvantage of this previously known solution lies in that a mass-containing magnet, whose magnetic field is required by the electronic sensor for detecting the location of the diaphragm, must be attached to the diaphragm for detecting the position of the diaphragm. The uneven mass distribution on the diaphragm required for this can lead to locally increased loads, which disadvantageously reduces the service life expectancy of the diaphragm. Because of the omission of a diaphragm stop, or support plate, on the displacement chamber side, refilling the hydraulic chamber in case of an operation at an admission pressure in the suction line, which lies above the pressure of the ambient air, is only possible if, by means of an additional pressure generator, the amount of hydraulic fluid to be replaced is brought to a somewhat slightly higher pressure than the admission pressure in the suction line In addition, the lack of the diaphragm stop can lead to an overload of the diaphragm under certain operating conditions.
Finally, a device for an electronic check of the diaphragm position in diaphragm process pumps is known from DE A1 43 36 823, wherein the position of the diaphragm is determined by means of an electromechanical or electronic transmitter and receiver. For an exact control for preventing breakage or premature wear by an overload, a signal, which controls the admission of the hydraulic medium to the displacement chamber, is generated by means of an electronic evaluation unit. An electromechanical sensor, which directly determines the position of the diaphragm by means of a spring-loaded plunger, is proposed for detecting the diaphragm position. In this case, too, the diaphragm is additionally stressed by the force of the plunger, which basically results in a reduced life expectancy of the diaphragm.
It is the object of the invention to create a diaphragm pump, wherein the volume of the displacement chamber can be checked in the simplest possible way, so that the diaphragm is treated gently and the operational dependability of the pump as a whole is increased.
This object is attained in connection with the diaphragm pump in accordance with the species in that a pressure sensor is arranged in the displacement chamber, which is connected with an evaluation unit designed for generating a refill signal, so that a refill unit is actuated by means of an operative connection. The pressure sensor located in the displacement chamber reports the creation of an underpressure during the intake stroke to the evaluation unit. There, this signal is compared, for example with a predetermined threshold value. As soon as the predetermined threshold value has been exceeded, the evaluation unit generates a signal which causes the refilling of the displacement chamber with hydraulic fluid. Overloading of the diaphragm is assuredly prevented in this way. The threshold value can be easily adapted to various operating conditions. Since the pressure sensor has no movable parts, the operational dependability is advantageously increased in comparison with mechanical systems. The diaphragm is not additionally stressed by the pressure sensor, since the latter is not in direct contact with the diaphragm and instead only comes into contact with the hydraulic medium.
Thus, the invention is based on the electronic evaluation of the chronological course of pressure in the displacement chamber of a hydraulically controlled diaphragm pump. Also, a selective allocation of this course of the pressure to the displacer position takes place. The correct filling of the displacement chamber is assured by means of an algorithm being run in a computer unit and by a refill unit, which is actuated by an operative connection. Occurring leaks, or a lack of hydraulic medium in the displacement chamber, are detected and a replacement is provided again.
If a support plate for the diaphragm is arranged in the displacement chamber, an additional, more distinctive underpressure pulse is generated in the displacement chamber as soon as the diaphragm comes to rests against the support plate during the intake stroke. This underpressure pulse can be evaluated even more precisely by the evaluation unit and a signal for refilling can be generated from this, which advantageously increases the operational dependability of the pump. For initiating the refilling process it is then possible for the evaluation unit to check that, for example, two criteria have been simultaneously met, i.e. that the diaphragm has reached its rearmost contact position and that the pressure in the hydraulic chamber lies slightly below the ambient pressure in the reservoir.
Refilling can be provided in a particularly advantageous manner if the refill unit is embodied as a valve, preferably an electrically actuated valve, which is arranged in the refill line Can make a connection between the displacement chamber and the reservoir for the hydraulic medium. Already operational diaphragm pumps can also be simply retrofitted, so that the advantages of the electronic triggering of the refill valve can also be utilized in connection with older pumps.
Because the evaluation unit is embodied to generate a venting signal, which is switched so it actuates a venting unit, it is also possible at a time during a work cycle of the displacer, in which the pressure in the displacement chamber is greater than the ambient pressure in the reservoir for the hydraulic fluid, to remove released air, which originally had been dissolved in the hydraulic medium, from the displacement chamber, if needed.
Because venting and replenishing of the displacement chamber take place at different-times, it is advantageously possible to do without separate valves. Both functions can be performed by the same valve if the venting valve and the refill valve are designed as one component. It is alternatively possible to remove the released air, which was originally dissolved in the hydraulic medium, from the displacement chamber through both the refill valve itself and through a further structurally equivalent, for example electromagnetically triggered venting valve. The refill and the venting valves can be designed to be structurally equivalent. The venting and the refilling processes take place as needed and not necessarily during each work cycle.
A further option without the use of a position sensor consists in the arrangement of a pressure sensor in the conveying chamber of the diaphragm pump in addition to the pressure sensor in the displacement chamber, with a signal connection to the evaluation unit. A linkage of the two sensor signals, for example by means of a differential formation, can take place in the evaluation unit, and the refill signals, or venting signals, can be generated.
By means of this, the dependable switching of the refill and of the venting valves is also assured under all operating conditions.
Alternatively, the pressure sensors can be designed as sensors for detecting the expansion of the housing components of the conveying chamber and the displacement chamber. These provide signals which are proportional to the pressure signals. The evaluation for generating the refill, or venting, signals can take place through appropriate signal connections to the evaluation unit.
Advantageously, the determination of the displacer position takes place in addition to detecting the pressure in the displacement chamber in that a position sensor is provided for signaling the displacer position, and a signal connection from the position sensor to the evaluation unit is provided. This additional information regarding the position of the piston, and the linkage of the piston position with the pressure signal allows additional interlocks, which dependably prevent the switching of the venting, or the aeration, valves at the wrong time.
Moreover, the arrangement of respectively a pressure sensor in the conveying chamber, a pressure sensor in the displacement sensor and a position sensor for detecting the displacer position, along with their respective signal connections to the evaluation unit, and the combined evaluation of all three sensor signals are possible.
In connection with the method for controlling the position of a diaphragm separating the conveying and the displacement chambers of a diaphragm pump, wherein the displacement chamber, which is equipped with a support plate, through which the hydraulic medium can flow, is connected via a refill unit with the displacement chamber, the attainment in accordance with the invention of the object provides that the pressure signal in the displacement chamber is detected by a sensor and is conducted to an evaluation unit which, in accordance with a defined algorithm, causes the refilling of the displacement chamber with a hydraulic medium as required from this and, if required, the venting of released gas portions, which originally had been dissolved in the hydraulic medium, from the displacement chamber.
Under certain conditions it is also possible to process a derivation in accordance with time or distance as the signal, instead of the measured actual pressure signal.
The pressure in the displacement chamber is advantageously detected by a sensor and is forwarded to an evaluation unit, which causes the venting of the displacement chamber in accordance with a defined algorithm.
The dependability of the method is further increased by a step, wherein the position of the displacer is detected, for example by an angle encoder on the driveshaft, and is provided to the evaluation unit, and the signal is linked with the pressure in the displacement chamber by the evaluation unit.
For causing refilling and/or venting of the displacement chamber, it is also alternatively or complementarily possible to detect the pressure in the conveying chamber and to provide it to the evaluation unit, and for the evaluation unit to link the signal with the pressure in the displacement chamber.
The invention will be described by means of a preferred embodiment, making reference to the drawings, wherein further advantageous details can be taken from the drawing figures. Functionally equivalent parts have been provided with the same reference numerals here.

Diaphragm pump and device for controlling same


According to one embodiment, an information processor includes an optical disc drive, a recorder, and a determination module. The optical disc drive includes a loading mechanism that loads and ejects an optical disc. The recorder obtains state information indicating the operating state of the loading mechanism to record the state information. The determination module determines that, when a value related to failure prediction of the loading mechanism satisfies a predetermined condition, there is a risk of failure in the loading mechanism. The value is calculated from a combination of a plurality of indices contained in the state information.

1. Field
One embodiment of the invention relates to an information processor, a failure prediction method, and a computer product.
2. Description of the Related Art
Information processors such as personal computers (PCs) are often provided with an optical disc drive (ODD) to read data from/write data to an optical disc including a compact disk (CD) and a digital versatile disk (DVD). The ODD has a disc tray on which an optical disc is placed, and is provided with a loading mechanism such as a loading motor for ejecting the disc tray or putting the disc tray in the housing. With this loading mechanism, an optical disc to be read or written is loaded into/ejected from the housing.
In such an information processor, if the loading mechanism of the ODD experiences a sudden failure, an optical disc cannot be loaded/ejected, resulting in inconvenience for the user. For this reason, some information processors with the ODD is capable of failure prediction and checks whether there is a risk of failure in the ODD.
Japanese Patent Application Publication (KOKAI) No. 2006-18955 discloses a known conventional technology related to ODD failure prediction. With the conventional technology, the number of loadings of the ODD, the number of seeks, and the number of data write blocks are counted and, when any of them exceeds a threshold, the use of the ODD or writing is prohibited.
According to the conventional technology, the risk of failure in the loading mechanism of the ODD is checked based only on the number of loadings as an index. When the number of loadings exceeds a predetermined threshold, it is determined that there is a risk of failure. Accordingly, failure prediction cannot be performed by taking into account the individual difference of the loading mechanism, user's use condition, and the like. As a result, highly accurate failure prediction cannot be achieved.

Information processor, failure prediction method, and computer product


An apparatus and a process is disclosed for applying a boron coating to a thin foil. Preferably, the process is a continuous, in-line process for applying a coating to a thin foil comprising wrapping the foil around a rotating and translating mandrel, cleaning the foil with glow discharge in an etching chamber as the mandrel with the foil moves through the chamber, sputtering the foil with boron carbide in a sputtering chamber as the mandrel moves through the sputtering chamber, and unwinding the foil off the mandrel after it has been coated. The apparatus for applying a coating to a thin foil comprises an elongated mandrel. Foil preferably passes from a reel to the mandrel by passing through a seal near the initial portion of an etching chamber. The mandrel has a translation drive system for moving the mandrel forward and a rotational drive system for rotating mandrel as it moves forward. The etching chamber utilizes glow discharge on a surface of the foil as the mandrel moves through said etching chamber. A sputtering chamber, downstream of the etching chamber, applies a thin layer comprising boron onto the surface of the foil as said mandrel moves through said sputtering chamber. Preferably, the coated foil passes from the mandrel to a second reel by passing through a seal near the terminal portion of the sputtering chamber.

Field of the Invention
This invention relates to applying coatings to thin foils. More particularly, this invention relates to applying boron carbide coatings to thin metallic foils. Even more particularly, this invention relates to a continuous process for applying a boron coating to metallic foils which are utilized to manufacture boron-coated straw neutron detectors.
Description of the Related Art
The application of neutron detection technology to the fields of national security, oil/gas exploration, nuclear safeguards, neutron science instrumentation and other areas is greatly expanding. Unfortunately, the neutron detection systems of choice which utilizes pressurized tubes of 3He have several limitations. While these systems can provide the needed spatial resolution and gamma ray discrimination, this technology cannot achieve high rate operation because of slow drift of positive ions. Furthermore, large detection areas are costly, because of the complexity of the pressure vessels required, and parallax errors limit the time-of-flight accuracy of the instrument. Perhaps the most problematic issue for the future of 3He detectors is a severe shortage of 3He. Existing stockpiles of 3 He will soon be depleted and only limited amounts are naturally available or available from decay of U.S. and Russian tritium supplies. Future instrument expansions will likely not afford the escalating cost of the dwindling 3He supply.
Recognizing the problems with 3He detector systems early on, Dr. Jeffery L. Lacy developed a new technology for replacing the 3He detectors. The technology was the boron-coated straw detector. The boron-coated straw (BCS) detector was based on arrays of thin walled boron-coated copper tubes. The elemental component of this detector was a long tube ("straw"), generally about 1 to 4 mm in diameter, coated on the inside with a thin layer of 10B-enriched boron carbide (10B4C).
Thermal neutrons captured in 10B are converted into secondary particles, through the 10B(n,α) reaction:10B+n→7Li+α  (1)The 7Li and α particles are emitted isotropically in opposite directions with kinetic energies of 1.47 MeV and 0.84 MeV, respectively (dictated by the conservation of energy and momentum). For a boron carbide layer that is only about 1 μm thick, one of the two charged particles will escape the wall 78% of the time, and ionize the gas contained within the straw.
Each BCS detector was operated as a proportional counter, with its wall acting as the cathode, and a thin wire tensioned through its center serving as the anode electrode, operated at a high positive potential. Primary electrons liberated in the gas drift to the anode, and in the high electric field close to the anode, avalanche multiplication occurs, delivering a very much amplified charge on the anode wire. Standard charge-sensitive preamplifier and shaping circuitry were used to produce a low noise pulse for each neutron event. Gamma interactions in the wall produced near minimum ionizing electrons that deposit a small fraction of the energy of the heavily ionizing alpha and Li products. Gamma signals were effectively discriminated with a simple pulse height threshold.
The boron-coated straw detector technology was first patented by Dr. Lacy in U.S. Pat. No. 7,002,159 entitled "Boron-Coated Straw Neutron Detector" based upon a Nov. 13, 2002, filing. As the thought leader of this technology area, Dr. Lacy continued his research and development to improve the boron coated straw detectors and to find new uses. Examples of Dr. Lacy's continued progress in this technology area are found in his other issued patents and pending patent applications which include: U.S. Pat. No. 8,330,116 entitled "Long Range Neutron-Gamma Point Source Detection and Imaging Using Rotating Detector"; U.S. patent application Ser. No. 12/792,521 filed Jun. 2, 2010, entitled "Optimized Detection of Fission Neutrons Using Boron-Coated Straw Detectors Distributed in Moderator Material" (allowed and issue fee paid); U.S. patent application Ser. No. 13/106,785 filed May 12, 2011, entitled "Sealed Boron-Coated Straw Detectors", U.S. patent application Ser. No. 13/106,818 filed May 12, 2011, entitled "Neutron Detectors for Active Interrogation"; and U.S. patent application Ser. No. 13/683,404 filed Nov. 21, 2012, entitled "Boron Coated Straw Detectors with Shaped Straws." These patent and pending applications mentioned in this paragraph are hereby incorporated by reference in their entirety for all purposes, including but not limited to those portions describing the structure and technical details of the boron-coated straw detectors as background and for use as specific embodiments of the present invention, and those portions describing other aspects of manufacturing and testing of boron-coated straws that may relate to the present invention.
Dr. Lacy also widely published articles on boron-coated straw detection capabilities, fabrication, and development of prototypes for various applications including:    J. L. Lacy, et al, "Novel neutron detector for high rate imaging applications", IEEE Nuclear Science Symposium Conference Record, 2002, vol. 1, pp. 392-396;    J. L. Lacy, et al, "Straw detector for high rate, high resolution neutron imaging", in IEEE Nuclear Science Symposium Conference Record, 2005, vol. 2, pp. 623-627;    J. L. Lacy, et al, "High sensitivity portable neutron detector for fissile materials detection", IEEE Nuclear Science Symposium Conference Record, 2005, vol. 2, pp. 1009-1013;    J. L. Lacy, et al, "Performance of 1 Meter Straw Detector for High Rate Neutron Imaging", IEEE Nuclear Science Symposium Conference Record, 2006, vol. 1, pp. 20-26;    J. L. Lacy, et al, "Long range neutron-gamma point source detection and imaging using unique rotating detector", IEEE Nuclear Science Symposium Conference Record, 2007, vol. 1, pp. 185-191,    J. L. Lacy, et al, "Fabrication and materials for a long range neutron-gamma monitor using straw detectors", IEEE Nuclear Science Symposium Conference Record, 2008, pp. 686-691;    J. L. Lacy, et al, "One meter square high rate neutron imaging panel based on boron straws", IEEE Nuclear Science Symposium Conference Record, 2009, pp. 1117-1121;    J. L. Lacy, et al, "Boron coated straw detectors as a replacement for 3He", IEEE Nuclear Science Symposium Conference Record, 2009, pp. 119-125;    J. L. Lacy, et al, "One meter square high rate neutron imaging panel based on boron straws", IEEE 2009 Nuclear Science Symposium Conference Record, 2009, pp. 1117-1121;    J. L. Lacy, et al, "Initial performance of large area neutron imager based on boron coated straws", IEEE 2010 Nuclear Science Symposium Conference Record, 2010, pp. 1786-1799;    J. L. Lacy, et al, "Initial performance of sealed straw modules for large area neutron science detectors", IEEE 2011Nuclear Science Symposium Conference Record, 2011, pp. 431-435;    J. L. Lacy, et al, "Straw-Based Portal Monitor 3He Replacement Detector with Expanded Capability", IEEE 2011 Nuclear Science Symposium Conference Record, 2011, pp. 431-435;    J. L. Lacy, et al, "Performance of a Straw-Based Portable Neutron Coincidence/Multiplicity Counter", IEEE 2011 Nuclear Science Symposium Conference Record, 2011, pp. 529-532;    J. L. Lacy, et al, "Replacement of 3He in Constrained-Volume Homeland Security Detectors", IEEE 2011 Nuclear Science Symposium Conference Record, 2011, pp. 324-325;    J. L. Lacy, et al, "Initial performance of sealed straw modules for large area neutron science detectors", IEEE 2011 Nuclear Science Symposium Conference Record, 2011, pp. 431-435;    J. L. Lacy, et al, "Boron-coated straws as a replacement for 3He-based neutron detectors", Nuclear Instruments and Methods in Physics Research, Vol. 652, 2011, pp. 359-363;    J. L. Lacy, et al, "Design and Performance of High-Efficiency Counters Based on Boron-Lined Straw Detectors", Institute of Nuclear Materials Management Annual Proceedings, 2012;    J. L. Lacy, et al, "Boron-coated straw detectors of backpack monitors", IEEE Transactions on Nuclear Science, Vol. 60, No. 2, 2013, pp. 1111-1117.    J. L. Lacy, et al, "The Evolution of Neutron Straw Detector Applications in Homeland Security", IEEE Transactions on Nuclear Science, Vol. 60, No. 2, 2013, pp. 1140-1146.Each of these publications is hereby incorporated by reference into this application in their entirety for all purposes.
The key sensing element in boron-coated neutron detectors has been the very thin (nominally about 1 μm) coating of 10B. There have been two approaches used in the prior art for laying down such coatings. One technique utilized by many manufacturers has been a chemical adhesion technique. A suspension of small 10B particles was introduced into the detector tube and allowed to evaporate at high temperature until a liquid binder solidified and bound the 10B particles to the detector wall. This method had many drawbacks including (1) residual binder was always present at high enough level to reduce the escape efficiency of the charged particles and hence lower efficiency; (2) the binder, depending on its composition, could introduce outgassing components into the counting gas and result in aging of the detector; (3) it was extraordinarily difficult to produce a uniform coating that was accurate to tenths of a micron causing variability in detector response along the longitudinal axis of the detector; (4) it was extraordinarily difficult examine the coating inside the tube after being deposited because the only entry into the tube was a narrow gas file port; and (5) many detectors utilizing this method demonstrated detachment of the thin film as the detector was exposed to thermal cycling and physical shock and vibration. The chemical binding employed by the method suffers from inconsistencies in procedure and from the basic weakness of the chemical glue like bond.
In a second method that was develop by Dr. Lacy, a sputtering technique was used to deposit enriched boron carbide on the thin substrate. As discussed in U.S. Pat. No. 7,002,159, the initial boron-coated straw detectors were made using ribbons of 10B coated material and helically winding those coated ribbons with a second ribbon having no coating as an outer overlapping layer (i.e., one over the other) with application of a very thin fast setting adhesive layer onto a precision cylindrical mandrel, producing a bonded and rigid, cylindrical detector straw.
The 10B ribbons were formed through vapor deposition of boron carbide (B4C), vapor deposited on aluminum or Mylar foils using a plasma deposition process. In the described embodiment, deposition was accomplished by wrapping narrow 9.5 mm wide and 25 μm thick strips or ribbons of the respective materials around a cylindrical drum (16″ diameter×16″ long), which thereafter was rotated adjacent to a sputtering head. A tape running down the side of the drum kept the strips in place (but also produced a 1 cm dead space every 50″). Using this process, a uniform boron carbide coating was achieved on continuous strips of material with a length up to 50 meters. Prior to straw construction the coating quality could be easily evaluated by very simple tests such as application of mechanical and thermal stress to assure 100% bonding reliability.
In practice, the method of producing the '159 patent coated ribbon was limited. This batch process required substantial time in preparation and pump down which limited the production capacity. Further, because the size of the production run was limited to the material fitting on the drum, therefore each production run produced a small quantity (approximately 0.8 m2 per day at a cost of over $3700 per/m2.
As can be seen, as the need for neutron detection systems expands, and boron-coated straw detector systems replace 3He detectors in many applications, there will be an increasing need for a method of manufacturing greater number of boron-coated straws for these detectors. Since the prior art process of manufacturing straws was limited by the amount of foil that can be coated, there exists a specific need for a better process that can produce the quality of boron-coating on the foil in increasing quantity.

Method and apparatus for coating thin foil with a boron coating


A desiccant type air dryer assembly having an integral purge volume with a body assembly and a removable desiccant cartridge. A retention bolt is provided in the body assembly which serves the two-fold function of retaining the cartridge and body assembly in an assembled condition as well as providing a flow passageway for air moving through the air dryer.

This invention relates to a component for a motor vehicle air brake system, and particularly, to an air dryer assembly.
Many motor vehicles, and in particular, heavy duty trucks incorporate air brake systems which use air pressure to control application of the vehicle service brakes. These systems have an air compressor driven by the vehicle engine which charges a brake system reservoir with high pressure air. The air compressor is controlled to supply air intermittently as needed to replenish the reservoir and maintain reservoir pressure within a predetermined range.
The process of compression of air results in the precipitation of water. Water and particulates in the air brake system can lead to component deterioration and interfere with optimal operation of the brake system. Accordingly, there are various devices used for removing water from the compressed air in air brake systems, known as air dryers. The function of an air dryer is to collect and remove air system contaminants in solid, liquid and vapor form before they enter the brake system. The air dryer provides clean, dry air for the components of the brake system which increases the life of the system and reduces maintenance costs. One type of air dryer incorporates a desiccant material which eliminates daily manual draining of water collection reservoirs as is required in other types of air dryers.
Desiccant type air dryers employ a volume of desiccant material which is hydrophilic and thus absorbs water which passes through an air line from the air compressor. High pressure air enters the desiccant air dryer and the water is stripped by the desiccant material. The air dryer also includes a particulate filter for trapping particulates and oil. Eventually, the desiccant material absorbs water to its maximum capacity. As a means of expelling this trapped water, modern desiccant type air dryers incorporate a backflow or purge air flow as a means of stripping the desiccant of absorbed water. A reservoir referred to as a purge volume is provided with is charged with the high pressure air supplied by the compressor. When the compressor cycles from a loaded mode producing compressed air to the unloaded mode, the purge volume air is allowed to leak to atmosphere through the desiccant bed in a reverse flow direction, stripping it of moisture and expelling it into the air. External purge volume air dryer types use a purge volume reservoir separate from the air dryer and connected to it by an air line. Another type is a so-called integral purge volume type in which the housing which contains a desiccant material also defines the purge volume. These types are in widespread use today and provide excellent performance.
In modern desiccant type air dryers some means of removing the desiccant material is provided since it requires rejuvenation after a service life period. In use, the desiccant material absorbs contaminants such as oil which ultimately reduces its water retention characteristics. Since other components of air dryers have a longer service life, a convenient system for removing the desiccant material is desired. In one type of air dryer, spin-on type desiccant cartridges are used. The desiccant cartridge resembles a conventional motor vehicle spin-on oil filter in a form of a canister with a load plate having a centrally threaded bore such that the entire unit is threaded onto an upstanding boss on a mounting surface. A new generation type of desiccant cartridge is being offered by the assignee of this application. In this type, a retention bolt which passes through the air dryer body with threads in the desiccant cartridge load plate. The retention bolt is externally accessible, allowing a tool to engage it for mounting and dismounting the desiccant cartridge. This invention is related to a desiccant cartridge of the later type.
In desiccant air dryers incorporating a desiccant cartridge, a number of isolated air flow passages and chambers are formed by these components which are sealed from one another and communicate in a controlled manner. Accordingly, both the desiccant cartridge and body assembly define a number of distinct flow paths requiring specific structural features. As with all components intended for mass production, designers of these components continually strive to reduce their costs in terms of material cost, and assembly and fabrication requirements.
In view of the foregoing it is an object of this invention to provide a desiccant type air dryer having design improvements intended to reduce component part, and assembly costs while providing high reliability and quality.

Desiccant air dryer with combined attachment and air flow management component


A semiconductor device including a control signal generator and an internal refresh signal generator is provided. The control signal generator generates first and second control signals, one of which is selectively enabled in response to temperature code signals and mode set signals after a pulse of an internal refresh signal is outputted by the internal refresh signal generator. The temperature code signals are obtained from temperature signals. The internal refresh signal generator outputs a refresh command signal as the internal refresh signal when the first control signal is enabled. Further, the internal refresh signal generator outputs the refresh command signal as the internal refresh signal at a moment that the refresh command signal is inputted thereto by a predetermined number of times when the second control signal is enabled.

1. Technical Field
Embodiments of the present disclosure generally relate to semiconductor devices, and more particularly to semiconductor devices including a control signal generator and an internal refresh signal generator.
2. Related Art
In the electronics industry, highly integrated fast volatile memory devices such as high performance dynamic random access memory (DRAM) devices widely used as memory devices are increasingly in demand with the development of higher performance electronic systems such as personal computers or communication systems. In particular, when semiconductor devices such as the DRAM devices are employed in cellular phones or notebook computers, the semiconductor devices have to be designed to have an excellent low power consumption characteristic. Accordingly, a lot of efforts have been focused on reduction of an operating current and a standby current of the semiconductor devices.
A data retention characteristic of a DRAM cell including a single transistor and a single storage capacitor may be very sensitive to a temperature. Thus, it may be necessary to control operation conditions of internal circuit blocks in a semiconductor integrated circuit according to variation of circumferential temperature. For example, DRAM devices employed in mobile systems may be designed to control a refresh cycle time according to variation of circumferential temperature. Temperature sensors such as digital temperature sensor regulators (DTSRs) or analog temperature sensor regulators (ATSRs) have been widely used to control the operation conditions of semiconductor devices such as DRAM devices according to variation of circumferential temperature. These temperature sensors may detect a relatively high temperature and may control an operation cycle time to reduce power consumption in a self-refresh mode. Further, the temperature sensors may monitor a circumferential temperature in a normal operation mode.
Meanwhile, the joint electron device engineering council (JEDEC) regulates a normal mode and an extended mode that control an operation cycle time (i.e., a refresh cycle time) of the semiconductor devices using a mode register set (MRS) in a refresh mode. The refresh cycle time of the semiconductor devices may be set to be reduced in the normal mode and may be set to be increased in the extended mode.


A fuel cell stack includes a first knock pin and a second knock pin. A separator has an outer peripheral shape having first and second short sides. The separator has a first knock pin insertion hole adjacent to the first side and a second knock pin insertion hole adjacent to the second side. The first and second knock pin insertion holes have a circular shape. The first insulating plate has third and fourth knock pin insertion holes. The second insulating plate has fifth and sixth knock pin insertion holes. The first knock pin is inserted into the third and fifth knock pin insertion holes to be movable in the third and fifth knock pin insertion holes. The second knock pin is inserted into the fourth and sixth knock pin insertion holes to be movable in the fourth and sixth knock pin insertion holes.

Field of the Invention
The present invention relates to a fuel cell stack.
Discussion of the Background
For example, a solid polymer-type fuel cell has an electrolyte film/electrode structure (MEA) in which an anode electrode is arranged on one surface of an electrolyte film including a polymer ion exchange membrane, and a cathode electrode is arranged on the other surface. A power generation cell (unit cell) is configured when the electrolyte film/electrode structure is put between separators. Normally, when a predetermined number of power generation cells are stacked, for example, the power generation cells are incorporated as an on-board fuel cell stack in a fuel cell vehicle (fuel cell electric vehicle, etc.).
In a fuel cell stack, a lot of power generation cells are stacked, and the power generation cells need to be accurately positioned with respect to each other in order to ensure desired sealing as the whole fuel cell stack.
In this regard, for example, there is a known method of assembling a fuel cell disclosed in Japanese Laid-open Patent Publication No. H9-134734. In this assembly method, a positioning hole for cell assembly is drilled in a pressure plate for pressing a stack, and a knock pin is inserted into the positioning hole for cell assembly in an erect posture. Subsequently, the knock pin is successively fit to cell positioning holes drilled in respective flat plate components, thereby configuring the cell.
Further, when the above-described operation is repeated, a predetermined number of power generation cells are stacked, and a stack is configured. Thereafter, when tightening and fixing are performed using a pressurization plate, the fuel cell is assembled.
For this reason, the flat plate components included in the fuel cell may be stacked without position shift to configure the power generation cells, and the power generation cells may be stacked without position shift and sealed at high accuracy.


A device, system and method for treating retinal detachment is presented. The device is generally comprised of a depressor, a cannula and a needle. In use, the depressor is used to create an indentation on the surface of the eye that can be viewed internally to determine the site for drainage. A cannula advancement mechanism is engaged and the cannula containing the needle is inserted into the determined drainage site. The needle is removed and an aspiration device is connected to the cannula to drain the subretinal fluid to treat retinal detachment.

Retinal detachment is a common cause of severe vision loss. In retinal detachment, the retina pulls away from the layer of blood cells which provide oxygen thus leaving the retinal cells lacking oxygen. Retinal detachment can occur when vitreous fluid leaks through a retinal hole or tear and collects underneath the retina. Tears or holes in the retina can occur for a number of reasons including disorders or aging that causes the retina to thin. A tear typically develops when there is a sudden collapse of the vitreous thus causing tugging on the retina with enough force to cause a tear. Fluid inside the vitreous may then travel through the tear and collect under the retina thus peeling it away from the underlying tissues which provide oxygen. In areas in which the retina is detached and the cells lack oxygen, vision may be lost if not treated quickly.
Rhegmatogenous retinal detachment is the most common etiology and is caused by a tear or hole that is usually in the peripheral retina.
Retinal detachment itself is painless, however symptoms are usually present before it occurs or advances. Symptoms of retinal detachment include the appearance of a large number of floaters; sudden flashes of light in the affected eye; and a shadow over a portion of the visual field that develops as the detachment progresses.
Several conditions may increase the chance of retinal detachment including nearsightedness; previous cataract surgery; eye trauma; previous retinal detachment in the other eye; family history of retinal detachment; or weak areas in the retina.
The principles of retinal detachment repair include identifying and treating the retinal breaks; draining the subretinal fluid; and internal or external tamponade of the breaks using scleral buckling or intravitreal gas or oil. Drainage of subretinal fluid is currently performed ab externo using an external sclerotomy, or ab interno using a drainage retinotomy. However, these techniques have significant disadvantages and complications. For example, external drainage with a sclerotomy requires an extensive dissection and cannot be done while directly visualizing the retina. External sclerotomy can also be complicated by hemorrhage, retinal incarceration, or iatrogenic retinal damage. Drainage retinotomy can be complicated by hemorrhage, recurrent detachment, or proliferative vitreoretinopathy. Internal drainage requires creating an iatrogenic retinal break.
Given the disadvantages in the current techniques for treating retinal detachment, what is needed is a device and system which would allow drainage site selection, drain placement and subretinal fluid drainage under direct visualization using an internal wide angle viewing system. Such a system would improve safety during drainage and avoid complications such as retinal incarceration and iatrogenic retinal breaks. A drainage retinotomy, which requires the creation of a posterior iatrogenic retinal break, can also be avoided.

Device and method for treating retinal detachment


In a video signal coder/decoder arrangement or codec for an image transmission system motion of picture elements between frames is encoded with reference to any one of eight preceding frames, so that picture information which repeats within eight frames does not need to be encoded again, and recovery after errors in transmission can commence with reference to the last-received uncorrupted frame of the eight.

1. Field of the Invention
The present invention relates to image transmission systems, and to methods of coding and decoding video signals for such systems.
2. Description of Related Art
Image transmission systems for video conferencing and video telephony are required to convey image information at low bit rates, typically at 64 kbit/sec. The image information transmitted over such systems must enable acceptable resolution of image detail and frequency of up-dating at a receiver, and for this purpose images to be transmitted may be presented for encoding as a succession of image frames, each made up of 288 lines of 360 pixels or pels, at a rate of ten frames per second. If the brightness and colour of each of these pixels is to be rendered at all accurately, full encoding of such a succession of image frames would give rise to a data rate of 10 Mbit/sec or more, and clearly only a very small proportion of this data could be transmitted over a 64 Kbit/sec channel.
Reduction of the data rate may be achieved by exploiting spatial redundancy within individual frames and temporal redundancy between successive frames. One way of taking advantage of temporal redundancy is to decompose each current frame into blocks of 8.times.8 pixels and, in respect of each such block, to look for a similar block in a portion of the succeeding frame in a "search window" of, say, .+-.7 pixels centred on the block under examination, in order to identify any movement of image elements between frames. A motion vector mapping each block to the similar block in the succeeding frame can then be associated with each block. Following this scheme it is possible to reconstruct the succeeding frame by translating blocks from the current frame according to the associated motion vectors. This technique is described, for example, by S. Kappagantula and K. R. Rao in IEEE Transactions on Communications, Volume Comm-33, No. 9, September 1985, pages 1011 to 1015.

Motion compensation image signal encoding system


An optical modulator component 2 has a substrate 4 for modulation made of an electro-optical material and having a joining face 4b; an optical waveguide 6 provided in or on the substrate 4 and having at least one pair of branched portions 6c; and a radio-frequency interaction portion 11 applying a voltage on the respective branched portions 6c to modulate light propagating through the branched portions. The optical waveguide 6 has end faces 15A, 15B, 15C and 15D present on the joining face 4b of the substrate 4 for modulation.

According to Japanese Patent Publication No. H4-355714A, an optical waveguide of an optical control element is turned back at an end face of a substrate, thereby extending an interaction length between a lightwave and a modulating wave, decreasing a drive voltage, compensating a matching velocity difference between the lightwave and a signal wave, and realizing a high-speed operation.
According to "Highly Functional Hybrid Modules Using Low Loss Direct Attachment Technique with Planar Lightwave Circuit and LiNbO3 Devices", T. Yamada et al., ISMOT-2005, pp. 107-110, 2005, a planar optical circuit (PLC) and an LN waveguide device are connected to each other. Moreover, Japanese Patent Publication No. 2005-173162A describes a connection between a PLC and an LN waveguide, and, on this occasion, there is a difference between mode field diameters of the optical waveguides on two substrates therefore, and there is thus provided a tapered portion for adjusting the difference in the mode filed diameter.
It should be noted that Japanese Patent Publication No. 2004-245991A describes a structure of using adhered fixtures at both chip ends.

Optical modulator component and optical modulator


A lubrication system for the helical gear thrust washer, helical gear journal and inter-axle differential in tandem drive axles. The leading drive axle input shaft is journalled in a bearing supplied on one side with a gravity flow of lubricant from a passage receiving lubricant slinging from the power divider periphery, which receives lubricant slinging from the axle ring gear. The opposite side of the bearing has an annular lubricant chamber therearound formed by an annular baffle member surrounding the input shaft on the interior side of the bearing. The bearing is operative to pump lubricant to the annular chamber. An axial passage formed through a portion of the input shaft communicates the annular chamber with the differential gears. In one form the annular baffle member rotates with the input shaft and in the other form it is stationary. In some embodiments the baffle has an elastomeric lip seal therearound; and, in the other embodiments, the baffle defines an annular labyrinth passage restricting return flow to the sump from the annular chamber.

The present invention relates to driving axles, and particularly to tandem arrangements of driving axles having an input shaft driving a power divider which, in turn, drives one of the driving axles and also an output shaft for connection to the second driving axle. Typically, the power divider takes the form of an inter-axle differential having the carrier containing the differential or spider gears driven by the input shaft. In such an inter-axle differential arrangement, the differential gears typically drive, on one side thereof, a helical gear which meshes with a pinion shaft gear for driving the pinion of the first driving axle. The opposite side of the differential gears typically mesh with a gear formed on the output shaft for driving the second drive axle. Usually, a clutching arrangement is provided on the helical gear for locking the helical gear to the input shaft when loss of traction in encountered at the wheels. Locking the interaxle differential allows the torque to be transferred to the axle with the most available traction.
It is common practice in tandem driving axle arrangements to provide a thrust washer for absorbing the axial loading of the helical gear by the differential gears for driving the first driving axle. The thrust washer typically bears on one side thereof against the helical gear and on its other side against a shoulder provided on the input shaft with the helical gear disposed annularly about the input shaft for free rotation thereon when the clutch is disengaged.
In such a thrust washer arrangement, severe wear problems have been encountered in heavy service both at the thrust washer and the helical gear journal; and, it has been determined that the wear problems are due, in part, to insufficient lubrication. Typically, lubrication to the power divider component in a tandem drive axle arrangement has been provided by splash from the ring gear to which the pinion shaft is engaged in the first driving axle whereby lubricant is thrown from the ring gear into the power divider area. However, this method of splash lubrication from the ring gear has not provided sufficient lubrication to a thrust washer located on the opposite side of the differential gears from the ring gear.
Thus, it has long been desired to provide a simple, economical, and easily manufactured way or means of providing lubricant to the thrust washer in the power divider in a tandem drive axle.

Power divider lubrication in tandem driving axles


A metal-air battery and a protected anode used therein, which make it possible to prevent the metal such as Li being an anode active material and formed into fine powder from dispersing away from the anode layer, and to improve charging and discharging cycle characteristics, even in the case of a charging and discharging cycle over a long period of time. For example, a protected anode 1 includes an anode current collector 32; an anode layer 33 which is stacked on an air electrode side of the anode current collector and which includes a metal being an anode active material of a metal-air battery; a first separator 34 which is stacked on the air electrode side of the anode layer and which includes multiple pores permeable to ions of the metal and an organic electrolytic liquid; and a second separator 40 which is provided on the air electrode side of the first separator so as to be movable relative to the first separator in an inter-electrode direction and which includes multiple pores permeable to the metal ions and the organic electrolytic liquid. In addition, the protected anode may be used to fabricate a metal-air battery.

A metal-air battery uses a metal such as lithium as an anode active material and uses oxygen in the atmosphere as a cathode active material, and is expected, thanks to its high energy density, as a battery capable of obtaining an energy density of 700 Wh/kg required for widespread use and standardization of electric automobiles. This energy density is seven times greater than those of lithium-ion batteries which are presently beginning to be mounted in vehicles.
Patent Document 1 discloses an internal structure of a protected anode of a metal-air battery is provided, as a buffer layer, with a porous resin sheet, for example a separator for a lithium-ion battery (a sheet of porous polyethylene, polypropylene, cellulose, or the like) impregnated with a non-aqueous electrolytic liquid and the like or a protection layer made of a polymer electrolyte and the like in order to prevent direct contact between a solid electrolyte (glass ceramics) and a Li anode. However, there is a problem that if Li deposited on the anode at the time of charging is formed into a fine powder and is dispersed, it becomes impossible to retain Li near the anode current collector and Li does not contribute to charging and discharging, resulting in a decrease in charging and discharging characteristics.
In addition, as disclosed in Patent Document 2, there is a method of suppressing dendrites by maintaining a uniform distance between the cathode and the anode, in which a metal foil laminate material having a high air-tightness is used as an exterior material of the metal-air battery, an air inlet is provided at a position not facing the held surface of the electrode assembly, and a uniform pressure is applied on the cathode. However, even when the dendrite can be suppressed, it is difficult to retain Li at the time of charging near the anode current collector, leaving a problem of how to improve the charging and discharging characteristics.
Moreover, a Li-ion capacitor disclosed in Patent Document 3 has a structure in which both surfaces of a metal Li plate are covered by two separators and end portions of the separators are melted and bonded to seal the metal Li plate. Thus, in the process of pre-doping at an early stage of cell fabrication, the metal Li plate dissolves after the injection of an electrolytic liquid and is dispersed in the electrolytic liquid as Li ions. Here, free small fragments of Li metal are prevented from flowing into the cell, resulting in the prevention of the deterioration in characteristics attributed to e.g. short circuiting.

Metal-air battery and protected lithium electrode used therein