A floor heating system includes a flooring substrate having a heating or cooling element in heat transfer relationship therewith. A heat spreader is in heat transfer relationship with the flooring substrate. The heat spreader includes a layer of flexible graphite material. A floor covering overlies the layer of flexible graphite material. Temperature variations across an exposed surface of the floor covering are reduced by the presence of the flexible graphite heat spreader, thus providing an improved and more uniform heating to the floor and to the room with which the floor is associated.

With the development of more and more sophisticated technological components, such as electronic components capable of increasing processing speeds and higher frequencies and fuel cell components requiring specific thermal and electrical conductivity, natural graphite has become a material a choice for certain components. Natural graphite is considered a uniquely advantageous material, since it combines desirable properties such as electrical and thermal conductivity and formability with relatively low weight, especially compared to metals like copper or stainless steel. As such, graphite articles have been proposed for various applications, including thermal management in electronics (specifically, thermal interface materials, heat spreaders and heat sinks), PEM fuel cell components like flow field plates and gas diffusion layers, and as a component of floor heating systems.
With the increased need for heat dissipation from microelectronic devices, thermal management becomes an increasingly important element of the design of electronic products. As noted, both performance reliability and life expectancy of electronic equipment are inversely related to the component temperature of the equipment. For instance, a reduction in the operating temperature of a device such as a typical silicon semiconductor can correspond to an exponential increase in the reliability and life expectancy of the device. Therefore, to maximize the life-span and reliability of a component, maintaining the device operating temperature within the control limits set by the designers is of paramount importance.
Heat sinks are components that facilitate heat dissipation from the surface of a heat source, such as a heat-generating electronic component, to a cooler environment, usually air. In many typical situations, heat transfer between the solid surface of the component and the air is the least efficient within the system, and the solid-air interface thus represents the greatest barrier for heat dissipation. A heat sink seeks to increase the heat transfer efficiency between the components and the ambient air primarily by increasing the surface area that is in direct contact with the air. This allows more heat to be dissipated and thus lowers the device operating temperature. The primary purpose of a heat sink is to help maintain the device temperature below the maximum allowable temperature specified by its designer/manufacturer.
Typically, heat sinks are formed of a metal, especially copper or aluminum, due to the ability of copper to readily absorb and transfer heat about its entire structure. In many applications, copper heat sinks are formed with fins or other structures to increase the surface area of the heat sink, with air being forced across or through the copper fins (such as by a fan) to effect heat dissipation from the electronic component, through the copper heat sink and then to the air.
Limitations exist, however, with the use of copper heat sinks. One limitation relates to copper's relative isotropy—that is, the tendency of a copper structure to distribute heat relatively evenly about the structure. The isotropy of copper means that heat transmitted to a copper heat sink become distributed about the structure rather than being directed to the fins where most efficient transfer to the air occurs. This can reduce the efficiency of heat dissipation using a copper heat sink. In addition, the use of copper or aluminum heat sinks can present a problem because of the weight of the metal, particularly when the heating area is significantly smaller than that of the heat sink. For instance, pure copper weighs 8.96 grams per cubic centimeter (g/cc) and pure aluminum weighs 2.70 g/cc (compare with graphite in the form disclosed herein, which typically weighs between about 0.4 and 1.8 g/cc). In many applications, several heat sinks need to be arrayed on, e.g., a circuit board to dissipate heat from a variety of components on the board. If copper heat sinks are employed, the sheer weight of copper on the board can increase the chances of the board cracking or of other equally undesirable effects, and increases the weight of the component itself. In addition, since copper is a metal and thus has surface irregularities and deformations common to metals, and it is likely that the surface of the electronic component to which a copper heat sink is being joined is also metal or another relatively rigid material such as aluminum oxide or a ceramic material, making a complete connection between a copper heat sink and the component, so as to maximize heat transfer from the component to the copper heat sink, can be difficult without a relatively high pressure mount, which is undesirable since damage to the electronic component could result. Moreover, oxide layers, which are unavoidable in metals, can add a significant barrier to heat transfer, yet are not formed with graphite.
An ion exchange membrane fuel cell, more specifically a proton exchange membrane (PEM) fuel cell, produces electricity through the chemical reaction of hydrogen and oxygen in the air. Within the fuel cell, electrodes denoted as anode and cathode surround a polymer electrolyte and form what is conventionally referred to as a membrane electrode assembly, or MEA. Oftentimes, the electrodes serve the dual function of gas diffusion layer, or GDL, within the fuel cell. A catalyst material stimulates hydrogen molecules to split into hydrogen atoms and then, at the membrane, the atoms each split into a proton and an electron. The electrons are utilized as electrical energy. The protons migrate through the electrolyte and combine with oxygen and electrons to form water.
A PEM fuel cell is advantageously formed of a membrane electrode assembly sandwiched between two graphite flow field plates. Conventionally, the membrane electrode assembly consists of random-oriented carbon fiber paper electrodes (anode and cathode) with a thin layer of a catalyst material, particularly platinum or a platinum group metal coated on isotropic carbon particles, such as lamp black, bonded to either side of a proton exchange membrane disposed between the electrodes. In operation, hydrogen flows through channels in one of the flow field plates to the anode, where the catalyst promotes its separation into hydrogen atoms and thereafter into protons that pass through the membrane and electrons that flow through an external load. Air flows through the channels in the other flow field plate to the cathode, where the oxygen in the air is separated into oxygen atoms, which joins with the protons through the proton exchange membrane and the electrons through the circuit, and combine to form water. Since the membrane is an insulator, the electrons travel through an external circuit in which the electricity is utilized, and join with protons at the cathode. An air stream on the cathode side is one mechanism by which the water formed by combination of the hydrogen and oxygen can be removed. Combinations of such fuel cells are used in a fuel cell stack to provide the desired voltage.
Recently, the use of natural graphite materials have been suggested for use as certain components of a PEM fuel cell. For example, gas diffusion layers and flow field plates made from flexible graphite sheets, such as Grafcell™ advanced flexible graphite materials, available from Graftech Inc. of Lakewood, Ohio, have been employed or disclosed for use in fuel cells.
Prior heating systems utilizing expanded graphite materials have been proposed in U.S. Pat. Nos. 5,288,429; 5,247,005; and 5,194,198; the details of which are incorporated herein by reference. The graphite materials used in those systems have been constructed so that they have generally isotropic thermal conductivities.
The different applications for graphite articles discussed above, as well as others not specifically addressed herein, require differing characteristics for optimization. For instance, a heat spreader may comprise a sheet which requires a maximum of thermal conductivity in the in-plane direction of the sheet (i.e., along the major surfaces of the sheet) in order to effectively spread heat as rapidly as possible. As a comparison, a gas diffusion layer (which can also function as an electrode, as noted above) for an electrochemical fuel cell, also generally in the form of a sheet, may require a certain degree of through-plane (i.e., between its major surfaces) electrical conductivity to assist in directing current flow, while still desiring as much in-plane thermal and electrical conductivity as possible.
Graphite is made up of layer planes of hexagonal arrays or networks of carbon atoms. These layer planes of hexagonally arranged carbon atoms are substantially flat and are oriented or ordered so as to be substantially parallel and equidistant to one another. The substantially flat, parallel equidistant sheets or layers of carbon atoms, usually referred to as graphene layers or basal planes, are linked or bonded together and groups thereof are arranged in crystallites. Highly ordered graphites consist of crystallites of considerable size: the crystallites being highly aligned or oriented with respect to each other and having well ordered carbon layers. In other words, highly ordered graphites have a high degree of preferred crystallite orientation. It should be noted that graphites possess anisotropic structures and thus exhibit or possess many properties that are highly directional e.g. thermal and electrical conductivity and fluid diffusion.
Briefly, graphites may be characterized as laminated structures of carbon, that is, structures consisting of superposed layers or laminae of carbon atoms joined together by weak van der Waals forces. In considering the graphite structure, two axes or directions are usually noted, to wit, the "c" axis or direction and the "a" axes or directions. For simplicity, the "c" axis or direction may be considered as the direction perpendicular to the carbon layers. The "a" axes or directions may be considered as the directions parallel to the carbon layers or the directions perpendicular to the "c" direction. The graphites suitable for manufacturing flexible graphite sheets possess a very high degree of orientation.
As noted above, the bonding forces holding the parallel layers of carbon atoms together are only weak van der Waals forces. Natural graphites can be chemically or electrochemically treated so that the spacing between the superposed carbon layers or laminae can be appreciably opened up so as to provide a marked expansion in the direction perpendicular to the layers, that is, in the "c" direction, and thus form an expanded or intumesced graphite structure in which the laminar character of the carbon layers is substantially retained.
Graphite flake which has been expanded, and more particularly expanded so as to have a final thickness or "c" direction dimension which is as much as about 80 or more times the original "c" direction dimension, can be formed without the use of a binder into cohesive or integrated sheets of expanded graphite, e.g. mat, webs, papers, strips, tapes, or the like (typically referred to as "flexible graphite"). The formation of graphite particles which have been expanded to have a final thickness or "c" dimension which is as much as about 80 or more times the original "c" direction dimension into integrated flexible sheets by compression, without the use of any binding material, is believed to be possible due to the mechanical interlocking, or cohesion, which is achieved between the voluminously expanded graphite particles.
In addition to flexibility, the sheet material, as noted above, has also been found to possess a high degree of anisotropy with respect to thermal and electrical conductivity and fluid diffusion, comparable to the natural graphite starting material due to orientation of the expanded graphite particles substantially parallel to the opposed faces of the sheet resulting from compression. Sheet material thus produced has excellent flexibility, good strength and a very high degree of orientation.
Briefly, the process of producing flexible, binderless anisotropic graphite sheet material, e.g. web, paper, strip, tape, foil, mat, or the like, comprises compressing or compacting under a predetermined load and in the absence of a binder, expanded graphite particles which have a "c" direction dimension which is as much as about 80 or more times that of the original particles so as to form a substantially flat, flexible, integrated graphite sheet. The expanded graphite particles that generally are worm-like or vermiform in appearance, once compressed, will maintain the compression set and alignment with the opposed major surfaces of the sheet. The density and thickness of the sheet material can be varied by controlling the degree of compression. The density of the sheet material can be within the range of from about 0.08 g/cc to about 2.0 g/cc. The flexible graphite sheet material exhibits an appreciable degree of anisotropy due to the alignment of graphite particles parallel to the major opposed, parallel surfaces of the sheet. In roll pressed anisotropic sheet material, the thickness, i.e. the direction perpendicular to the opposed, parallel sheet surfaces comprises the "c" direction and the directions ranging along the length and width, i.e. along or parallel to the opposed, major surfaces comprise the "a" directions and the thermal, electrical and fluid diffusion properties of the sheet are very different, by orders of magnitude typically, for the "c" and "a" directions.
With respect to electrical properties, the conductivity of anisotropic flexible graphite sheet is high in the direction parallel to the major faces of the flexible graphite sheet ("a" direction), and substantially less in the direction transverse to the major surfaces ("c" direction) of the flexible graphite sheet. With respect to thermal properties, the thermal conductivity of a flexible graphite sheet in a direction parallel to the major surfaces of the flexible graphite sheet is relatively high, while it is relatively low in the "c" direction transverse to the major surfaces.
Given the different uses to which graphite articles produced from flexible graphite sheet are applied, it would be highly advantageous to predetermine or control the anisotropic ratio of the article, in order to optimize certain functional characteristics of the graphite articles for the particular end use. By anisotropic ratio is meant, with respect to either thermal or electrical conductivity, the ratio of in-plane conductivity to through-plane conductivity.

Flexible graphite flooring heat spreader


An exemplary method and system are described for providing an easy to use interface for establishing multi-media audio conference calls involving a leader and a plurality of participants. A web-based interface can be used by the leader for establishing, controlling, and providing information associated with the call. Participants can also access the web-site for receiving information associated with the call and receiving status information regarding the conference call. In one embodiment, an address organizer can be used to select participants by the leader and schedule an audio conference call with the recipients having the opportunity to accept, decline, or indicate an alternative telephone number at which they can be reached.

Audio telephonic conferencing services are well known and several variations are commonly available for use by both residential and business users. One of the simplest versions is known as three-way calling, and allows the originator of a call to add on a third party to an existing call. This process is typically initiated by the user initiating a 'hookflash', which is a temporary depression of the "hook-switch" on a telephone. The hook-switch is the switch on a telephone that when depressed, terminates an active call. Conversely, when the hook switch is lifted (e.g., removing the receiver), dial-tone is provided. For telephone lines provisioned with three-way calling service, the temporary depression of the hook-switch while a call is active is interpreted by the telephone central office (CO) as a request for three-way calling. The CO places the active call on hold and provides dial-tone to the user. The user can dial the telephone number of the third party to be joined to the call. Once the third party has answered, the user can then invoke a second 'hook-flash' and conference in the third party into the call. For proper operation, the depression of the hook-flash switch must be of a minimum duration, but not too long. Many users find this operation difficult to use and either depress to hook too short (which may not be recognized by the CO, or too long, resulting in the call being terminated).
Another form of audio conferencing is six-way audio conferencing capability. This variation is also CO-based, and operates similar to three-way calling, but allows up to four additional parties to be joined to an active call. Again, many users find the control of the conference via the hook switch even more difficult given that more participants may be involved.
Because of the difficultly in operating this feature, various other conferencing services have been developed, such as the 'meet-me' conference. In this embodiment, a multi-port conference bridge is reserved and callers are given an access telephone number and a PIN. This allows callers to dial into the bridge, provide their PIN as authorization, after which they are then connected to the conference bridge. No depression of the switch hook is required.
Other versions of conference calling have been developed in which a conference bridge controller initiates calls to a set of previously indicated telephone numbers, and automatically bridges in the participants.
All such versions provide limited control to the leader of the conference call. The leader is common nomenclature for the person originating the conference call. In some current versions, the leader is given limited additional control over the call. For example, in the aforementioned three-way calling services, if the leader disconnects, the conference call is terminated. Further, the leader can terminate the last person added. In contrast, the participants typically have very little control or information over a conference call they are involved with.
Many individuals find existing conference calling services difficult to use, or limited in their functionality. Therefore, systems and methods are needed for enhancing the control of audio conference services.

Systems and methods for multi-media control of audio conferencing


A new cultivar of Clematis named xe2x80x98Pretty in Bluexe2x80x99 that is characterized by upright violet-blue flowers in spring, summer and autumn, upright to decumbent habit, long blooming period, and medium-green foliage In combination, these traits set xe2x80x98Pretty in Bluexe2x80x99 apart from all other existing varieties of Clematis known to the inventor.

Genus: Clematis.
Species: xc3x97hybrida.
Denomination: Pretty in Blue.
The present invention relates to a new and distinct cultivar of Clematis that is grown for use as an ornamental in the landscape. The new cultivar is known botanically as Clematis and will be referred to hereinafter by the cultivar name xe2x80x98Pretty in Bluexe2x80x99.
xe2x80x98Pretty in Bluexe2x80x99 resulted from a formal breeding program that was established by the inventor in 1992 in Boskoop, Holland. The purpose of the breeding program was to find out if the inventor could successfully crossbreed two species, which had not been accomplished in 140 years, and in doing so produce hardy varieties that are easy to propagate, exhibit improved flower color and resistance to pests and disease.
The female parent plant is Clematis integrifolia xe2x80x98Olgaexe2x80x99 (unpatented) and the male parent plant is Clematis recta (unpatented). xe2x80x98Pretty in Bluexe2x80x99 is a hybrid plant that resulted from the hybridization between the pollen parent Clematis recta and the seed parent Clematis integrifolia xe2x80x98Olgaexe2x80x99. The cross was conducted by the inventor in a cultivated area of Boskoop, Holland and xe2x80x98Pretty in Bluexe2x80x99 was selected by the inventor in 1996 based on the unique flowers, long blooming period, ease of propagation, and free-flowering.
xe2x80x98Pretty in Bluexe2x80x99 is a perennial exhibiting an upright to decumbent habit, upright violet-blue flowers with contrasting yellow stamens, large inflorescences and a long period of free-flowering. Propagation is accomplished using softwood cuttings. The closest comparison plant is Clematis xe2x80x98Aromaticaxe2x80x99 (unpatented). xe2x80x98Pretty in Bluexe2x80x99 is distinguishable from xe2x80x98Aromaticaxe2x80x99 by a longer blooming period and ability to be easily and readily propagated. xe2x80x98Pretty in Bluexe2x80x99 differs from the female parent plant in flower color and habit, while differing from the male parent plant in flower color.
The first asexual propagation was accomplished by the inventor in 1996 in a cultivated area of Boskoop, Holland. Asexual propagation of the new cultivar by cuttings at the location previously stated, has shown that the unique features of the new Clematis cultivar xe2x80x98Pretty in Bluexe2x80x99 are stable and the plant reproduces true to type in successive generations of asexual propagation.
The following represent the distinguishing characteristics of the new Clematis cultivar xe2x80x98Pretty in Bluexe2x80x99. In combination these traits set xe2x80x98Pretty in Bluexe2x80x99 apart from all other existing varieties of Clematis known to the inventor. xe2x80x98Pretty in Bluexe2x80x99 has not been tested under all possible conditions and phenotypic differences may be observed with variations in environmental, climatic, and cultural conditions, however, without any variance in genotype.
1. Clematis xe2x80x98Pretty in Bluexe2x80x99 exhibits upright violet-blue flowers with contrasting yellow stamens.
2. Clematis xe2x80x98Pretty in Bluexe2x80x99 is free-flowering and blooms over a long period of time.
3. Clematis xe2x80x98Pretty in Bluexe2x80x99 is readily propagated using softwood cuttings.
4. Clematis xe2x80x98Pretty in Bluexe2x80x99 exhibits an upright to decumbent habit.
5. Clematis xe2x80x98Pretty in Bluexe2x80x99 exhibits medium-green foliage.
6. Clematis xe2x80x98Pretty in Bluexe2x80x99 is a perennial exhibiting large inflorescences.
7. Clematis xe2x80x98Pretty in Bluexe2x80x99 is hardy to USDA Zones 5and6.

Clematis plant named xe2x80x98Pretty in Bluexe2x80x99


A document scanning system is disclosed which utilizes a scan carriage mounted on guide rails which are connected between novel support members. The support members are mounted at one location only to a fixed base support. The guide rails do not require mounting to a side frame structure; the support structure providing the stability usually provided by the sides of a frame. The guide rails are inherently stable and provide the support for the scan load components. The second embodiment of the invention uses a single guide rail to support the optical system rather than plural guide rails.

This invention relates to an optical document scanning system for a document reproduction machine and, more particularly, to an improved assembly for supporting the optical components used during the document scan operation.
In the document reproduction art, an original document to be reproduced is typically placed on a stationary platen and illuminated by a incremental line-scanning optical system. Reflected light rays from the document travel along an optical path and are projected by a lens on to a photosensitive image member. The latent image of the document formed on the image member is then developed by appropriate marking material, and the developed image transferred to a record medium such as paper. Various types of scan mechanisms are known in the art, but the most widely used utilize a pair of guide rails which are mounted in a parallel plane beneath the document platen. The scanning components are mounted on one or more movable scan carriages which are driven by a cable arrangement to run back and forth beneath the platen and supported by the guide rails. Examples of such prior art scan systems employing an elongated illuminated lamp and scan mirrors to scan/illuminate the document are shown in U.S. Pat. Nos. 4,367,945, 4,155,641 and 4,603,963. The document to be reproduced may also be scanned by a raster input scanner (RIS), typically a CCD sensor array. The RIS type scanner is supported for movement beneath the document platen and is moved in the scan, re-scan direction by a scan assembly basically similar to the ones used in the above-identified patents. U.S. Pat. No. 4,500,197 discloses a RIS type scan system. The prior art scanning system can be characterized as being secured to, and supported by, the sides of a frame assembly. Thus, U.S. Pat. No. 4,367,945 to Abe discloses a scanning support structure for an electrostatic copying machine comprising a guide rail 22 and a guide rod 23 which together support and absorb the loads of two movable carriages 12 and 14, while being supported by frame members 20 and 21. U.S. Pat. No. 4,155,641 to Sagara et al. discloses a scanning apparatus comprising three parallel guide rods 52, 53, and 54, attached to a beam member 20, which support the loads imposed by two movable optical scanning carriages 50 and 51. U.S. Pat. Nos. 4,603,963 to Hinton et al., and 4,710,017 to Watanabe et al. are references which disclose scanning systems comprising a pair of frame supported parallel guiding members which absorb the shock and loads of a moving carriage apparatus within an electrostatic copying machine. U.S. Pat. No. 4,500,197 to Dannatt discloses a support structure for a flat bed scanner comprising a pair of parallel, elongated guide rods 55 and 62 fixed to left and right end plates 14 and 16, which form rigid support for the loads imposed by a movable RIS optical scanning carriage assembly 12.

Self supporting optical document scanning system


A maximum likelihood detector receiving a data stream corresponding to ideal values which may include noise, and outputting information specifying a sequence of states of maximum likelihood selected from possible states corresponding to the data stream according to weighting value selections made by the processors, the ideal values being determined by the possible states, including: a pre-processor to obtain first weighting values; processors in a hierarchy, each processor in a select level of the hierarchy is programmed to use, respectively, a plurality of the weighting values to calculate subsequent weighting values indicating respective likelihoods that a section of the data stream values corresponds to each of a plurality of possible state sequences, for each possible initial state and each possible final state, to select further weighting value of highest likelihood corresponding to a state sequence from the initial state to the final state.

A random process can be defined on the set of states of a finite state machine. A corresponding sequence of random state transitions can be visualised as a path on a trellis diagram. The problem of finding the most probable trellis path which connects two given states is of a great practical importance. This problem arises in such diverse areas as the theory of error-free communication, adaptive planning, the theory of traffic flows. In applications related to communication theories, most probable path-searching algorithms are used to reduce noise from signals transmitted over noisy channels (CDMA2000, Gigabit internet, etc), combat both inter symbol interference and channel noise in magnetic and optical storage devices, maintain communications with deep space research probes (e. g. Galileo).
Markov processes with Gaussian randomness are of particular practical importance. An example is an additive Gaussian white noise (AWGN) communication channel. In this situation, the problem of finding the most probable path reduces to the problem of finding the path of lowest weighting on a trellis, whose branches are equipped with weightings which are real numbers called branch metrics. The latter problem can be solved using methods of maximum likelihood detection. Maximum likelihood detection may include detection of transmitted data and estimation of transmitted symbols which formed part of the data before the effect of noise and/or interference during transmission. Maximum likelihood detection may also include the further step of decoding the data from an encoded format, although this is not an essential feature of a maximum likelihood detector.
In the following discussion, the term "detection" includes the process of recovering signals that are subject to noise and/or known interference, such as inter-symbol interference (ISI) of a known shape. However, if a deliberate encoding process has also been performed on the data, "decoding" is required to recover the signals in their pre-encoded form. For example, if encoding has been performed on purpose to increase resistance of the transmitted signals to noise, then "decoding" can be used to obtain the original pre-encoded signals.
It follows that a "detector" does not require any decoding means for decoding from a deliberate encoding process. However, a detector which includes such decoding means for decoding from a deliberate encoding process may be known as a "decoder". The decoding means may be configured to work separately or integrally with the detection means. Thus, in the following discussion, a "decoder" is a type of detector which also performs decoding. The hard disk drive examples discussed below are maximum likelihood "detectors", because the process involved is recovery of signals, where no purposeful encoding was performed on the data. However, everything that is discussed below is also applicable to decoders.
Both detectors and decoders usually output an estimate of a signal before encoding or interference. However, it is possible for a decoder or a detector to output a different sequence, e.g. outputting encoded signals which are corrected for interference and/or noise, or correcting for transmission noise but not correcting for inter-symbol interference.
A prior art method known as the Viterbi algorithm (VA) is particularly well known for solving the above problem of finding the most likely path in a trellis. VA is a recursive procedure, which can be most easily described when used with a known initial state at time t=0, and a known final state at time t=T. VA allows the most likely sequence of states at intermediate times to be found. FIG. 1A shows an example of a two-state trellis diagram which can be used to visualise the VA process. The trellis diagram is a state transition diagram which graphically represents all of the possible states of the system over a sequence of time intervals. The horizontal axis of the trellis represents the times of the state transitions, starting at time t=0 at the left hand side of the trellis, and ending with time t=T at the right hand side of the trellis. The vertical axis represents the possible states of the finite state machine. These possible states are zero and one. Pairs of possible states at adjacent time intervals are connected by lines, with each line representing a state transition. The possible sequences of states over the whole of the time period are represented by the possible paths along the trellis. At time t=0, the system is pre-set to state zero. At the next time interval, t=1, the state may remain as zero or change to one. This is represented by the darker upper and lower lines of the trellis between t=0 and t=1. A change of state from zero to one is represented by the upper line, extending diagonally upwards to connect to one at t=1, and a sequence of all zero states is represented by the lower line, extending horizontally to connect to zero at t=0. At time t=1, if the system is in state one, it may then follow one of two routes, i.e. remain at one, or change to zero. Similarly, if the system is in state zero, it may follow one of a further two routes, i.e. remain at zero, or change to one. At time t=T, the system is reset to zero.
As can be seen from FIG. 1A, the trellis contains one or more paths between each possible initial state and final state. For instance, there are two different paths from the "zero" state at time t=0 to the "zero" state at t=2. These paths are 010 and 000, where the first bit represents the state at time t=0, the second bit represents the state at time t=1, and the third bit represents the state at time t=2. FIG. 1B shows an identical trellis to FIG. 1A, with these two paths in bold lines. VA involves identifying paths between any possible states at time t−1, and each possible state at time t. If more than one path connects from t−1 to a particular state at time t, then VA chooses which of these paths corresponds to the most likely state sequence. Then, the least likely paths are eliminated. The remaining path is called the survivor.
The most likely path can be calculated using numbers known as branch metrics, which indicate the likelihood of each transition. FIGS. 1A and 1B show a number beside each line in the trellis, and this number is the branch metric for that state transition. The branch metrics for all state transitions in a path from time t1 to time t2 can be summed to indicate the likelihood of that particular path occurring. These sums of branch metrics are known as path metrics.
To find a survivor at a given state at time t=t+1, the path metrics of all paths leading to this state are computed by adding appropriate branch metrics to the path metrics of survivors at time t and choosing the path of lowest path metric (also known as the shortest path) leading to the state. This procedure is called add-compare-select operation and it has to be performed for all states at t=t+1. As t=T is reached, there will be only one survivor left, with probability P=1−C1·exp(−C2·T), where C1 and C2 are constants. Thus, the probability approaches 1 as time T increases and C1·exp(−C2·T) becomes small.
A specific example of the application of a use of VA in data transmission will now be described. When data is transmitted over a noisy channel, it is beneficial to encode the data first, using convolution encoding, to allow a degree of error correction. Convolution encoding is a bit level encoding technique where each coded bit is generated by convolving the input bit with the past input bits. Thus the information content of each input bit is spread over a number of coded bits, improving the error resistance of the data. If the encoded bits are then transmitted through a noisy environment, and if a particular encoded bit is very strongly affected by noise, information relating to the original input bits is still preserved in the encoded bits which are less affected by noise. The constraint length K of the convolution encoder is the number of bit shifts over which a single input bit can influence the encoder output. VA can then be used to detect and/or decode the convolution encoded data.
A convolution encoder can be represented by a generator function G(D), defined as follows:
            G                    (        D        )              =                  ∑                  n          =          0                          K          -          1                                                                      g          n                                  D          n                      ,where Dn is a delay operator representing a delay of n time units, K is the encoder constraint length and gn's are real numbers, which describe the weight with which past transitions contribute to the current reading.
Another example of convolution encoding occurs in a hard disk read system. Each bit on the disk surface generates a magnetic field, which is detected by the disk read head in order to read the bit, but the read operation is also affected by the magnetic field produced by the neighbouring bits. Thus, any data value obtained in a read operation actually corresponds to a convolution of magnetically recorded bits on the disc. This is known as inter symbol interference (ISI).
VA may be used to decode convolution encoded data, encoded either by deliberate encoding or by an interference process such as inter symbol interference. Various types of a Viterbi detector may be used, depending on the constraint length of the encoder used to encode the data, and the weightings given to previous input data. One type of Viterbi detector is known as "PR4" (partial response system of class IV). "Partial response" refers to the fact that in a partial response system, e.g. in a hard disk drive read system, each bit on the disk gives a multi-bit detected sequence, rather than just a single bit. A PR4 system gives a two bit detected sequence, and the encoder output is constructed from the current encoder input minus a past input delayed by two time units, i.e. an output of 1−D2, where D2 represents a delay of two time units. The following example illustrates a convolution encoder which has an output of 1−D, i.e. the encoder output is constructed from the current encoder input minus a past input delayed by one time unit.
FIG. 2 shows a block diagram of a prior art apparatus for transmission and reception of convolution encoded data. An encoder 100 performs convolution encoding of a stream of input data. The data is then sent over a noisy channel. Noise source 104 represents the effect of noise during transmission of the data. The transmitted data is then received and decoded by a maximum likelihood detector 108. The apparatus of FIG. 2 may represent a communications system, with deliberate convolution encoding of data to increase noise resistance during transmission through a channel. However, it may also represent a hard disk read process, in which the convolution encoding is not deliberate, but is a result of inter symbol interference caused by the magnetic fields of the individual data bits on the disk.
The encoder 100 has a constraint length of two, meaning that a single input bit of the encoder influences two bits of the received data. The encoder 100 has an input 101 for accepting a stream of time dependent input binary data xi, where i represents the time interval. The input data is received by the encoder at a rate of k bits/second. The input 101 of the encoder 100 is connected to an encoder delay element 102. The delay element 102 stores a single bit of data, corresponding to the input bit xi at time i, and outputs this data bit at the following time interval i+1. Thus, at time i, the output of the delay element is xi−1. The output of the delay element 102 is connected to a multiplication unit 103 which multiplies the output value xi−1 by minus one, giving an output of −xi−1. The encoder 100 has a sum unit 104 which is connected to both the encoder input 101 and the output of the multiplication unit 103. The signals xi and −xi−1 are summed by the sum unit 104, to give an output signal of yi=xi−xi−1.
The encoder output signal yi is sent from the output 105 of the encoder 100 via a channel, such as a radio link, a wire, or any other form of data transmission channel, to a detector 108. Noise source 106 represents noise ni generated as the signal yi passes through the channel. The noise source may generate Gaussian white noise, but the actual form of the noise generated does not have to be Gaussian, although in this example, it must be de-correlated noise. A sum unit 107, with inputs connected to the noise source 106 and the encoder output 105, represents the addition of the noise ni to the data yi. Thus, the signal received after the data has passed through the noisy channel is ri=yi+ni. The detector 108 receives the signal ri, and the detector then performs a detecting and decoding process.
FIG. 3 illustrates the trellis diagram structure corresponding to the encoder of FIG. 2, and the method used by a VA detector 108 to detect the received data ri. A series of eight trellis diagrams are shown, representing eight steps of the VA decoding process. A ninth trellis diagram shows a traceback of the optimal path through the trellis. The numbers on the trellis diagrams represent branch metrics, indicating the likelihood that received data corresponds to particular state transitions. Each trellis diagram is similar to that described with reference to FIG. 1, i.e. it has two possible states which are one and zero, and it extends from a known state zero at time t=0 to a known state zero at time t=T. The known states of zero can be set by feeding an initial zero to the encoder to re-set the state of the delay element to zero, and then by transmitting an extra character of zero at the end of the data transmission. A path through the trellis represents a sequence of data which is input to the encoder. Any unique data sequence input to the encoder has a unique path through the trellis.
The state of the trellis, with a value of zero or one, represents a possible value of xi−1. xi−1 is a possible value of the convolution encoder input, which may be stored in the delay element 101. The possible values of the convolution encoder output yi=xi−xi−1 are thus represented by the slope of the lines connecting two states of the trellis at adjacent time intervals i−1 and i. The yi values also represent ideal values of the received data, without any added noise ni. Lines with a zero slope, (such as state zero at t=0 and state zero at t=1) correspond to yi=0. Lines with a left-to-right upwards slope (such as state zero at t=0 and state one at t=1) correspond to yi=1. Lines with a left-to-right downwards slope (such as state one at t=1 and state zero at t=2) correspond to yi=−1. The values of yi are known as "branch labels" of the trellis. The branch labels can be used together with the received data to obtain the branch metrics of the trellis, as will now be described.
When the detector 108 receives the transmitted signal, this received signal ri includes noise ni. Thus, the problem to be solved by the detector is to determine the most likely path through the trellis (i.e. the most likely sequence of characters input to the encoder), based on the noisy received signal. Branch metrics are assigned to the trellis, to indicate the likelihood of each state transition. For Gaussian white noise, the branch metrics can be calculated as (ri−yi)2, i.e. the square of the difference between the received value ri and the expected value yi for that particular state transition. The most likely path is the path with the lowest total weight, i.e. the lowest sum of branch metrics.
When branch metrics are calculated as (ri−yi)2 for the 2-state trellis of FIG. 3, it is common to get a lot of paths having equal path metrics. It may not always be possible, therefore, to choose a single path of greatest likelihood, as one of two equally likely paths must be chosen. Therefore, for the purposes of illustrating the technique of finding a unique path through the trellis using VA, the values shown on FIG. 3 as branch metrics have not been calculated from a chosen set of ri, but instead, short integers have been chosen for each branch metric to ensure different weights for each path. In practice, although the presence of multiple paths of equal likeliness degrades the VA performance, it is often possible to pre-process the data to avoid getting large numbers of equally likely paths.
The first trellis diagram, at the top of FIG. 3, corresponds to step 1 of the detection and/or decoding process. Step 1 concerns the time interval between t=0 and t=1. The state of the system at t=0 is zero, because the delay element was preset to zero before data transmission began. Two possible paths through the trellis during the first time interval are identified as bold lines on the trellis. These correspond to data sequences of 00 and 01 respectively, where the first bit represents the state at time t=0 and the second bit represents the state at time t=1. The 00 path is the lower of the two paths in the trellis, and the 01 path is the higher of the two paths in the trellis. The 00 path has a path metric of 0, but the 01 path has a path metric of 2. As only a single path is formed between the initial state at t=0 and each final state at t=1, no reduction of the trellis is performed at step 1.
The second trellis corresponds to step 2 of the decoding process. The part of the trellis between t=0 and t=2 is now considered. A total of four paths are now possible, namely, 000, 001, 010 and 011, where the first two bits represent the possible paths in step 1, and the third bit represents the state at time t=2. The path metric of each path may be calculated by adding the branch metrics for each state transition on the path. Thus, the path metric of 000 is 0+2=2, of 001 is 0+0=0, of 010 is 2+1=3, and of 011 is 2+1=3. The paths 000 and 010, with path metrics of 2 and 3 respectively, both lead to a final state of 0 at time t=2. Therefore, the 010 can be eliminated, as it has the highest path metric, and the 000 path is the survivor. Similarly, the paths 001 and 011, with path metrics of 0 and 3 respectively, both lead to a final state of 1 at time t=2. Thus, the 011 path can be discarded, and the 001 path is the survivor. The two survivor paths, 001 and 000, are shown in bold on the trellis diagram.
In step 3 of the process, the part of the trellis up to t=3 is considered. The four new possible paths are 0010, 0011, 0000 and 0001, with path metrics of 0, 0, 3 and 4 respectively. The path 0000 with path metric 3, and the path 0001 with path metric 4, can both be eliminated, as these have highest path metrics for final states 0 and 1 respectively. Thus, the survivors are 0010 and 0011, each with a path metric of 0.
In step 4 of the process, the part of the trellis up to t=4 is considered. The four new possible paths are 00100, 00101, 00110 and 00111, with path metrics of 1, 2, 2 and 0 respectively. The paths 00101 and 00110 can be eliminated, as these have highest path metrics for final states 1 and 0 respectively. Thus, the survivors are 00100 and 00111, each with a path metric of 0.
In step 5 of the process, the part of the trellis up to t=5 is considered. The four new possible paths are 001000, 001001, 001110 and 001111, with path metrics of 3, 3, 1 and 0 respectively. The paths 001000 and 001001 can be eliminated, as these have highest path metrics for final states 0 and 1 respectively. Thus, the survivors are 001110 and 001111, with path metrics of 1 and 0 respectively.
In step 6 of the process, the part of the trellis up to t=6 is considered. The four new possible paths are 0011100, 0011101, 0011110 and 0011111, with path metrics of 3, 2, 2 and 1 respectively. The paths 0011100 and 0011101 can be eliminated, as these have highest path metrics for final states 0 and 1 respectively. Thus, the survivors are 0011110 and 0011111, with path metrics of 2 and 1 respectively.
In step 7 of the process, the part of the trellis up to t=7 is considered. The four new possible paths are 00111100, 00111101, 00111110 and 00111111, with path metrics of 2, 4, 3 and 3 respectively. The paths 00111110 and 00111101 can be eliminated, as these have highest path metrics for final states 0 and 1 respectively. Thus, the survivors are 00111100 and 00111111, with path metrics of 2 and 3 respectively.
In step 8 of the process, the part of the trellis up to t=8 is considered. At t=8, the state is set to zero, since a reset signal will be sent at the end of the transmission. Thus, only two paths need be considered instead of four. The two paths are 001111000, 001111110, with path metrics of 2 and 4 respectively. As both paths have the same final state, the path 001111110, which has the highest path metric, can be eliminated. Thus, the only survivor is 001111000, with a path metric of 2.
The ninth trellis shows traceback of the path with the lowest overall path metric, where only the final survivor path is shown in bold, and dead-end paths are no longer shown in bold.
In the absence of any additional noise ni, the received data input to the detector or decoder is an "ideal input". For a trellis of finite length, an ideal input is a sequence of received data with a corresponding path in the trellis which has a path metric of zero. In other words, for an ideal input, there is a corresponding path which has a sequence of branch labels which is equal to the sequence of received data.
Using VA, the number of steps needed to find the shortest path on a trellis of length N is O(N), which can lead to a prohibitively large computation time. Standard methods of speeding implementations of VA rely on deep pipelining, which leads to large latency delays and increased complexity of implementation due to necessity to manage large amount of memory needed to store information about survivors and their path metrics.
One high speed alternative to the Viterbi algorithm is the Fettweis approach, described in U.S. Pat. No. 5,042,036. Fettweis is a two step process. Firstly, the trellis is divided into multi-step sections, each of length M. Within each of these sections of length M, the least likely paths are eliminated. To do this, Fettweis considers in turn each possible initial state at the start of the length-M section, and considers a subset of the trellis beginning at that state. Depending on the Markov process on which the trellis is based, it is highly likely that after a certain number of state transitions, the highest-likelihood path through the trellis will become independent of the initial state. Fettweis defines a number F, such that after F states, all of the paths are highly likely to converge. E.g. the first F states will depend on the initial state chosen, but after that, all paths will be the same, regardless of which initial state was chosen. F is dependent on the trellis diagram and the initial values of the branch metrics.
Fettweis makes use of this high likelihood of path convergence to reduce part of the trellis to a single path, even though the initial and final states are not previously known. Thus, Fettweis does not need to actually calculate the path through the trellis for every possible initial state of the section. The whole path through the section can be calculated for just one initial state, and then only the first part of the path (which is dependent on the initial state) needs to be calculated for all other initial states. The ability of the Fettweis method to find a likeliest path without knowledge of the initial and final states allows VA to be parallelised, with several sections of length M being reduced in parallel.
When sections of the trellis have been reduced to a single path using the Fettweis method, the sections are re-connected to find the most likely complete path. It is possible to choose overlapping trellis sections to be reduced to connecting sections of single path, so that no further calculation is needed to find the complete path. It is also possible to choose trellis sections to be reduced to obtain a trellis with intermittent sections of single path, and to use standard VA either forwards or backwards from known reduced sections of the path to determine the unknown parts of the path.
However, Fettweis has the considerable disadvantage that the basic sections of input data must each be greater in length than 5K (i.e. 5 times the constraint length). This is because, as a general rule, the non-converging length F which occurs at the start of each section of input data must have a length of 5K or more. The exact value is dependent on the particular structure of the trellis diagram and the values of the branch metrics, however, F will always be at least 5K, due to the need to assign zeros to the start of the sequence, and due to the minimum length required for statistical convergence of the paths from different initial states. In practical maximum likelihood detectors, it is frequently undesirable to use input data sections of such a long length.
A further disadvantage of Fettweis is the large latency between data input to the detector and decoded data output from the detector. This latency is prohibitively high for many practical applications.

Maximum likelihood detector and/or decoder


A new marker device is provided for increased safety due to a flexible design. The marker device includes a base and a flexible means that is positioned over the base. The bottom part of the flexible means is attached to the base. The flexible means maintains in an original position in absence of a natural or traffic perturbation. However, flexible means deviates from this original position in presence of a natural or traffic perturbation. Moreover, the flexible means restores from this deviated position back to the original position after the perturbation disappears or is removed. Furthermore, the marker device includes a cover to cover the flexible means.

The present invention relates generally to traffic marker devices or safety cones used to alert or divert vehicles, watercrafts, aircrafts and pedestrians to pass safely around hazards, obstacles or other areas. More particularly, the present invention relates to a flexible safety marker device which self-positions to its original position, deviates from its original position due to natural or traffic perturbations, and restores to its original position from a deviated position in case such perturbations disappear or are removed.
Traffic or safety cones, are routinely used to direct motorists and pedestrians away from obstacles or dangerous area. These cones are usually brightly colored, hollow conical shaped devices made of a synthetic, rubber or other plastic (See for example U.S. Pat. No. 2,333,273 to Scanlon et al.). Traffic and safety cones are meant to minimize damage to persons or vehicles which may collide with the cones. However, safety cones are still of significant danger to the public. One reason is that, although the traffic cones are made out of a synthetic, rubber or other plastic, they are still relatively rigid and tend to fall over easily when the cones are subject to natural or traffic wind, perturbations by passing traffic or violence. Furthermore, safety cones that are, for instance, run over or hit by a vehicle, could become dangerous objects or obstacles by being airborne or simply laying on the road, in particular to following traffic or surrounding people.
A variety of different self-righting traffic cones have been proposed. For instance, U.S. Pat. No. 3,386,409 to Dietz Company describes to shape the base of the cone in such a manner that the cone is nestable or stackable self-righting in the manner of a self-righting top. The objective of U.S. Pat. No. 3,386,409 is to provide a nestable cone which, when it has been toppled over, will not roll away but will right itself and stand erect near to the position in which it was originally placed. This was accomplished by a hollow molded plastic traffic cone that has a base portion weighted to give a low center of gravity to the cone. The annular bottom of the base is gradually curved outward and upward to provide rockers so the cone is self-righting and is divided into six angularly spaced triangular legs to prevent rolling when the cone is knocked over.
U.S. Pat. No. 5,888,016 to Eui Sig Ahn et al. describes a traffic collar cone that has a delineator having a reflection sheet attached on its upper part. A plug is placed under the sheet having an air inlet and outlet extending upwardly and downwardly therethrough. A conical body member is provided, having in its upper end wall an insertion hole in which the plug is mounted. A support panel is provided at the bottom of the body and cone collars are attached on the outer surface of the body member, with vertical spacing between them. The traffic collar cone is made of flexible material and designed to recover its original shape after being impacted, so that injury to collar cone is eliminated or minimized.
U.S. Pat. No. 5,993,105 to Chan describes a safety marker that includes a hollow frusto-conical body and a base having a bowl-shaped main portion and a resiliently flexible skirt for yieldably stabilizing the marker against tipping relative to a supportive surface.
So far the solutions have focused on self righting of the traffic cone. However, these solutions are still not satisfactory from a safety standpoint since they still are either too rigid or can still relatively easy fall over. Accordingly, there is a need to develop a better traffic cone or marker device that further improves road and traffic safety.
The present invention provides a new marker device for increased safety due to a flexible design. The marker device of the present invention includes a base and a flexible means that is positioned over the base. The bottom part of the flexible means is attached to the base. The flexible means is, for instance, but not limited to, a coil and maintains in an original position in absence of a natural or traffic perturbation. However, flexible means deviates from this original position in presence of a natural or traffic perturbation. Moreover, the flexible means restores from this deviated position back to the original position after the perturbation disappears or is removed. Furthermore, the marker device of the present invention includes a cover to cover the flexible means. In addition, the present invention includes a light source to illuminate the marker device. The light source could be placed inside the cover and attached to the cover, flexible means or the base.
In view of that which is stated above, it is the objective of the present invention to provide a flexible marker device or cone to improve safety.
It is still another objective of the present invention to provide a marker device with a flexible means that positions itself to an original position.
It is still another objective of the present invention to provide a marker device with a flexible means that deviates from its original position to a new position and wherein the deviation is dependent on the type of perturbation.
It is still another objective of the present invention to provide a marker device with a flexible means that restores from the deviated position back to its original position, whereby the restoring mechanism in an inherent property of the flexible means.
It is yet another objective of the present invention to provide a marker device with a base that is less likely to fall over as a result of a perturbation.
It is yet another objective of the present invention to provide a marker device with a light source to illuminate the marker device.
The advantage of the present invention over previous devices is that the present marker device can more easily resist various types of perturbations without falling over. Yet another advantage is that the marker device of the present invention significantly reduces the damage to persons or vehicles. These advantages are accomplished by a marker device with a base that remains on the ground and a flexible part that deviates from its original position due to a perturbation in any direction and in any type of way irrespective of the type of perturbation.


An electromagnetic interference shielding assembly includes an enclosure and top and bottom covers. The enclosure has interconnected walls arranged in a polygonal configuration to surround an electronic component on a circuit board. Each wall has upper and lower portions extending in opposite directions. The enclosure has upper and lower releasable attachment arrangements respectively formed in the upper and lower portions of the walls and releasably engaged with the top and bottom covers. The upper and lower attachment arrangements are substantially mirror images of one another and define upper and lower annular channels that are open respectively from above and below. Each of the top and bottom covers has a main portion and side portions attached to and extending from the main portion and arranged in a polygonal configuration matching that of the walls of the enclosure. The side portions of top and bottom covers are removably inserted into the corresponding upper and lower annular channels and into frictional fitting relation with the upper and lower portions of the enclosure to thereby removably mount the covers to the enclosure.

1. Field of the Invention
The present invention generally relates to shielding devices for minimizing electromagnetic interference and, more particularly, is concerned with an enclosure and an assembly employing the enclosure and opposing covers interfitted with releasable attachment means defined on opposite upper and lower portions of the enclosure which provide for effective shielding of circuit board components against electromagnetic interference.
2. Description of the Prior Art
Electronic components found in various types of transmitters, receivers, computers and other electronic devices emit or are susceptible to electromagnetic radiation. It is therefore desirable to shield circuit components to reduce undesirable electromagnetic interference (EMI) and/or susceptibility effects with the use of conductive shields that reflect or dissipate electromagnetic charges and fields. Such shields are generally grounded to allow electrical charges and fields to be dissipated without disrupting the operation of the electronic components enclosed within the shield.
Various types of shielding devices for electronic components mounted on printed circuit boards have been proposed in the prior art. Representative examples of such shielding devices are those disclosed in U.S. Pat. No. 4,754,101 to Stickney et al., U.S. Pat. No. 4,841,414 to Hibino et al., U.S. Pat. No. 5,014,160 to McCoy, Jr., U.S. Pat. No. 5,043,848 to Rogers et al., U.S. Pat. No. 5,095,177 to Johnson, U.S. Pat. No. 5,160,807 to Fry et al., U.S. Pat. No. 5,175,395 to Moore, U.S. Pat. No. 5,354,951 to Lange, Sr. et al., Japan Pat. No. 62,595 to Tsunoda and German Pat. No. 3,736,833 to Bardon. These shielding devices frequently include a base frame which is mounted to a printed circuit board and surrounds circuit board components and a cover which fits over and connects with the base frame and encloses the printed circuit board components.
Various difficulties may be encountered with respect to providing a satisfactory connection of the cover to the base frame. The connection must secure the cover to the base frame in a reliable manner which prevents dislodgement due to shock and vibration. At the same time, the connection must permit easy removal of the cover for periodic visual inspection of the components enclosed by the shield.
The one shielding assembly disclosed in U.S. Pat. No. 5,354,951 to Lange, Sr. et al., and assigned to the assignee of the present invention, has a connection configuration which has been found to be highly satisfactory in releasably securing a top cover to an enclosure of the shielding assembly. The enclosure of the shielding assembly of this patent includes a plurality of interconnected walls for surrounding an electronic component on a circuit board, a plurality of mounting pins attached to lower portions of the walls for attachment to the circuit board, and a plurality of outer and inner tabs formed in upper portions of the walls for releasably mounting the top cover thereto. The tabs are disposed in a spaced, alternating and offset relationship to one another along the upper portions of the walls so as to create an annular channel between the outer and inner tabs extending along the upper portions of the walls. The top cover has side portions which are removably insertable into the annular channel of the upper portions of the walls of the assembly and into a frictional fitting relation therewith to thereby removably mount the top cover over the enclosure and provide an effective electromagnetic interference shield for the electronic component.
It has been perceived by the inventors herein that a continuing need still exists for improvements in the design of shielding devices for circuit board components that will adapt such devices for use in other applications.

Circuit board component shielding enclosure and assembly having opposing covers interfitted with upper and lower portions of enclosure


A method and apparatus for cutting teeth in workpieces, wherein, in a roughing operation, a substantially uncut blank receives rough teeth using a cutting tool having cutting teeth. Operation teeth are produced, the tooth width of which is defined by the spacing between the flanks of the teeth and is greater than the target dimension. In a subsequent deburring operation, a chamfer is incorporated into the end face edge of the tooth flanks, accompanied by the removal of an end face burr. Lastly, in a smoothing operation, the tooth width of the teeth is brought to the target dimension by machining the tooth flanks.

For cutting teeth in substantially cylindrical blanks as described, for example, in DE 102 49 039 B4, teeth are first cut into a blank using a gear cutting tool that has cutting teeth. The teeth may be provided by gear hobbing, and preferably by hob peeling. A hob peeling process for cutting teeth in internally or externally geared workpieces is described in DE 10 2005 049 528 A1. In the generic method, rough gearing is first produced using the cutting tool. This is carried out in a roughing operation. Following this first method step, the tooth flanks are deburred, in particular in the region of their end-face edges. The deburring may be carried out using a method as described in abovementioned DE 102 49 039 B4, or also in DE 103 09 116 A1. A chamfer is pressed into the edge region between the tooth flank and the end face of the workpiece. The material that is thus displaced is for the most part pushed into the end face, where it is removed using a deburring wheel. A secondary burr may remain in the flank region. This secondary burr is removed in a third method step, a so-called smoothing operation. The roughing operation and the smoothing operation are carried out using the same cutting tools, which are shaped in such a way that they may be used to produce the tooth gaps and the teeth of the workpiece to the target dimension.

Apparatus and method for cutting teeth in workpieces and associated tool set


A method of inputting e-mail addresses at an image forming apparatus, the method including accessing a server storing member information about members who have contacted a user online, by using log-in information of the user; receiving the member information stored in the server from the server; generating a list of e-mail addresses of the members by using the received member information; and updating an address book stored in the image forming apparatus by using the list of generated e-mail addresses.

1. Field
One or more embodiments of the following description relate to an image forming apparatus and a method of inputting e-mails thereat.
2. Description of the Related Art
Image forming apparatuses include office automation apparatuses (e.g., multi-function product (MFP)), which are single apparatuses capable of performing a plurality of functions used at an office, such as printing, photocopying, scanning, faxing, etc. An MFP may perform individual functions of various apparatuses, such as a printer, a scanner, a photocopier, and a facsimile, or perform a combination of functions thereof. Recently, image forming apparatuses having a network function to communicate with other terminals, such as a PC, are becoming popular.

Image forming apparatus and method of inputting e-mail thereat


An optical information storage disk especially adapted for tamper-proof monitoring by an electronic article surveillance (EAS) system. The compact disk hereof includes a generally planar, annular first disk surface and an opposed, generally annular second disk surface, a plurality of generally concentric data tracks on at least one of the disk surfaces, a centered aperture and a generally annular EAS magnetic marker concentrically oriented about the centered aperture. The annular EAS marker comprises a dual status, multi-directional marker with a selectively demagnetizable, essentially linear magnetic switching field. The marker is preferably received within a grooved recess in one of the disk surfaces and is immovably retained within the grooved recess by a coating covering the disk surface.

The now familiar compact disk preserves information as a series of microscopic pits and smooth areas, oriented in concentric circular or helical tracks, on the otherwise smooth, planar surface of an annular disk. Recorded information is read from a compact disk by directing a focused laser beam along the recorded tracks, and detecting variations in the intensity of the laser beam as it encounters the microscopic pits and smooth areas on the disk. The coherence and relatively short wavelength of laser radiation enables large volumes of information to be written onto very small spaces of a recording medium.
Compact disks were first introduced in the music recording industry in 1982, and now account for 43% of all recorded music sales. In the United States alone, over three hundred million compact disks are sold annually, with a retail value of over three billion dollars, according to the Recording Industry Association of America.
The recording industry has for the last ten years packaged the five inch in diameter prerecorded compact disks in six inch by twelve inch cardboard boxes known in the industry as "longboxes." The longbox is easily propped up in display bins alongside traditional vinyl LPs in music store display bins. More importantly, however, the bulk of the longbox makes it difficult for a shoplifter to hide a prerecorded compact disk under a coat or in a purse and walk out of a music store without paying.
While the longbox packaging technique for prerecorded compact disks has been somewhat effective as an anti-theft device, the excess packaging it creates accounts for as much as twenty five million pounds of packaging waste annually. The Recording Industry Association of America accordingly announced in 1991 its intention to abandon the longbox. In February of 1992, the Association announced that, beginning in April 1993, all prerecorded compact disks would be marketed in five inch by five and one half inch packages.
Electronic article surveillance systems for monitoring the egress of sensitive objects from controlled spaces are well known, and have been used alone and along with the longbox packaging technique for controlling the unauthorized taking of compact disks. Markers formed from a piece of high permeability magnetic material can be placed on the packaging for the disk. Spaced apart detection panels are then placed across the access points to and from the store, library or other repository for the monitored compact disks. The panels include field coils and detector coils for producing a magnetic field across the access point that can detect the passage of a marker between the panels. If a person attempts to carry a compact disk through the magnetic field presented by the panels without first deactivating the marker on the disk packaging, the presence of the marker will be detected and an alarm initiated.
U.S. Pat. No. 4,710,754 discloses a multi-directional EAS marker especially designed for its compact dimensions. The marker disclosed in the '754 patent is comprised of a high permeability, low coercive force, generally planar magnetic responder material that includes at least two narrow regions defining switching sections, and adjacent, wider, flux collector sections. The juxtaposition of the narrow switching sections with the flux collector sections causes the flux to be highly concentrated in the switching sections. The high concentration of flux lines in the switching sections produces high frequency harmonics when passed through an alternating magnetic field, allowing the presence of the marker in the field to be detected. The marker is conveniently made dual status, i.e., reversibly deactivatable and reactivatable, by including a piece of remanently magnetizable material adjacent each of the switching sections. The remanently magnetizable material, when magnetized, biases the adjacent switching section to either keep the magnetization therein from reversing when in an alternating interrogation field, or at least altering the response of the marker in the field. In either case, readily distinguishably different signals are produced by the marker in an interrogation field depending on whether the remanently magnetizable material is magnetized or demagnetized.
U.S. Pat. No. 4,967,185 discloses a multi-directional, dual-status EAS marker also designed for its compact dimensions. The marker disclosed in the '185 patent discloses a marker that includes a continuous uninterrupted sheet of remanently magnetizable material overlying a sheet of responder material similar to that disclosed in the '754 patent. The response of the marker within an alternating magnetic field can be discernably altered by selectively magnetizing and demagnetizing the continuous sheet of remanently magnetizable material prior to introducing the marker into the field.
The markers disclosed in the above noted prior art can be attached to the packaging for a compact disk. Problems arise, however, when attempting to attach prior art markers directly to the surface of a compact disk. Rotation of the compact disk is required to read information from the disk, and the disk must accordingly be inherently balanced. An EAS marker, applied directly to a compact disk, therefor, would preferably be somehow concentrically mounted on the disk without imbalancing the disk. Prior art EAS markers, however, are not inherently balanced. Moreover, conventional compact disks include a centered aperture that must be maintained clear of obstructions, and the preferred prior art dual status EAS markers include a continuous sheet of magnetic material, such that the marker cannot be concentrically mounted to the surface of a compact disk without obstructing the disk aperture.
U.S. Pat. No. 4,709,813 proposed an anti-theft device for compact disks that overcame the inability to directly apply an EAS marker to the surface of a compact disk. The '813 patent discloses a detachable locking plate with an EAS marker carried on the internal face of the plate that can be selectively locked to the "jewelry box" for a compact disk. The compact disk is physically locked in the box leg by the plate. A clerk or other authorized person can remove the plate with the use of a keyed release tool at the time of payment. It will be appreciated that the use of a locking plate requires preparation time to attach a plate to each compact disk cartridge, adds an additional step in the check-out process, and leaves the compact disk without EAS protection once the EAS marker carrying plate is removed from the compact disk. The lack of EAS protection once the plate is removed makes it especially risky for a retailer to permit the trial playing of a compact disk by a customer in the store before the compact disk is purchased.
The new packaging standard for prerecorded compact disks, while environmentally sound, will exacerbate the problem of compact disk shoplifting, since the smaller packages will be easier to hide and transport out of a store. While the use of electronic article surveillance systems could partially compensate for the increased shoplifting threat, it will be appreciated that the unauthorized removal of the magnetic markers from a package will defeat the detection capability of the surveillance system, and known EAS markers cannot be directly mounted on a compact disk without affecting the operability of the disk. The use of an EAS marker in conjunction with a locking plate presents handling problems and does not solve the problem of physical security of compact disks at stores where the customer is allowed to listen to the compact disk prior to purchase. A new, compact optical information disk especially designed for tamper-proof use with an electronic article surveillance system through the use of an EAS marker that could be applied directly to the surface of the compact disk would accordingly provide decided advantages.

Optical information storage disk for use with electronic article surveillance systems

Minnesota Mining and Manufacturing Company


The invention is directed to compositions and methods for the detection of a malignant condition, and relates to the discovery of soluble and cell surface forms of HE4a polypeptides, including HE4a that is overexpressed in ovarian carcinomas. In particular the invention provides a nucleic acid sequence encoding HE4a, and also provides a method of screening for the presence of a malignant condition in a subject by detecting reactivity of an antibody specific for a HE4a polypeptide with a molecule naturally occurring in soluble and/or cell surface form in a sample from such a subject, and by hybridization screening using an HE4a nucleotide sequence, as well as other related advantages.

Cancer includes a broad range of diseases, affecting approximately one in four individuals worldwide. The severity of the adverse impact of cancer is profound, influencing medical policy and procedure as well as society generally. Because a hallmark of many types of cancer is rapid and unregulated proliferation of malignant cells, an overarching problem in improving approaches to cancer is the need for early detection and diagnosis. Numerous attempts have been made to develop accurate and reliable criteria for diagnosing the presence of a malignant condition. In particular, efforts have been directed to the use of serologically defined antigenic markers known as tumor associated antigens, which are either uniquely expressed by cancer cells or are present at markedly higher levels in subjects having a malignant condition.
However, due to the high heterogeneity of tumor associated antigen expression, for example the extreme diversity of carcinoma antigens, there is a need for additional tumor markers that are useful in cancer diagnosis. Many monoclonal antibodies reactive with carcinoma associated antigens are known (see, e.g., Papsidero, 1985 Semin. Surg. Oncol. 1:171, Allum et al., 1986 Surg. Ann. 18:41). These and other described monoclonal antibodies bind to a variety of different carcinoma associated antigens including glycoproteins, glycolipids and mucins (see, e.g., Fink et al., 1984 Prog. Clin. Pathol. 9:121; U.S. Pat. No. 4,737,579; U.S. Pat. No. 4,753,894; U.S. Pat. No. 4,579,827; U.S. Pat. No. 4,713,352). Many such monoclonal antibodies recognize tumor associated antigens that exhibit restricted expression on some but not other tumors originating in a given cell lineage or tissue type.
There are only relatively few examples of tumor associated antigens that appear to be useful for identifying a particular type of malignancy. Monoclonal antibody B72.3, for example, specifically binds to a high molecular mass (>106 Da) tumor-associated mucin antigen that is selectively expressed on a number of different carcinomas, including most if not all ovarian carcinomas and an overwhelming majority of non-small cell lung carcinomas, colon carcinomas and breast carcinomas (see, e.g., Johnston, 1987 Acta Cytol. 1:537; U.S. Pat. No. 4,612,282). Nevertheless, detection of cell-associated tumor markers such as the mucin antigen recognized by B72.3 following surgical resection of a tumor may be of limited usefulness for diagnostic screening, in which early detection of a malignant condition prior to accumulation of substantial tumor mass is preferred.
An alternative to the diagnosis of a particular type of cancer by screening surgically resected specimens for tumor associated antigens, where invasive surgery is usually indicated only after detection of an accumulated tumor mass, would be to provide compositions and methods for detecting such antigens in samples obtained from subjects by non-invasive or minimally invasive procedures. In ovarian and other carcinomas, for example, there are currently a number of soluble tumor associated antigens that are detectable in samples of readily obtained biological fluids such as serum or mucosal secretions. One such marker is CA125, a carcinoma associated antigen that is also shed into the bloodstream, where it is detectable in serum (e.g., Bast et al., 1983 N. Eng. J. Med. 309:883; Lloyd et al., 1997 Int. J. Canc. 71:842). CA125 levels in serum and other biological fluids have been measured along with levels of other markers, for example, carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), tissue polypeptide specific antigen (TPS), sialyl TN mucin (STN) and placental alkaline phosphatase (PLAP), in efforts to provide diagnostic and/or prognostic profiles of ovarian and other carcinomas (e.g., Sarandakou et al., 1997 Acta Oncol. 36:755; Sarandakou et al., 1998 Eur. J. Gynaecol. Oncol. 19:73; Meier et al., 1997 Anticanc. Res. 17 (4B):2945; Kudoh et al., 1999 Gynecol. Obstet. Invest. 47:52; Ind et al., 1997 Br. J. Obstet. Gynaecol. 104:1024; Bell et al. 1998 Br. J. Obstet. Gynaecol. 105:1136; Cioffi et al., 1997 Tumori 83:594; Meier et al. 1997 Anticanc. Res. 17 (4B):2949; Meier et al., 1997 Anticanc, Res. 17 (4B):3019).
Elevated levels of serum CA125 alone or in combination with other known indicators, however, do not provide a definitive diagnosis of malignancy, or of a particular malignancy such as ovarian carcinoma. For example, elevated CA125, CEA and SCC in vaginal fluid and serum correlate most strongly with inflammation in benign gynecological diseases, relative to cervical cancer and genital tract cancers (e.g., Moore et al., 1998 Infect. Dis. Obstet. Gynecol. 6:182; Sarandakou et al., 1997 Acta Oncol. 36:755). As another example, elevated serum CA125 may also accompany neuroblastoma (e.g., Hirokawa et al., 1998 Surg. Today 28:349), while elevated CEA and SCC, among others, may accompany colorectal cancer (Gebauer et al., 1997 Anticanc. Res. 17 (4B):2939). Another marker, the differentiation antigen mesothelin, is expressed on the surfaces of normal mesothelial cells and also on certain cancer cells, including epithelial ovarian tumors and mesotheliomas. Compositions and methods pertaining to mesothelin (Chang et al., 1992 Canc. Res. 52:181; Chang et al., 1992 Int. J. Canc. 50:373; Chang et al., 1992 Int. J. Canc. 51:548; Chang et al., 1996 Proc. Nat. Acad. Sci. USA 93:136; Chowdhury et al., 1998 Proc. Nat. Acad. Sci. USA 95:669; Yamaguchi et al., 1994 J. Biol. Chem. 269:805; Kojima et al., 1995 J. Biol. Chem. 270:21984) and structurally related mesothelin related antigen (MRA; see, e.g., Scholler et al., 1999 Proc. Nat. Acad. Sci. USA 96:11531) are known in the art, including uses in cancer detection and therapies as described in WO 00/50900 and in U.S. application Ser. No. 09/513,597. Thus the compelling need for additional markers to be used, including markers useful in multi-factor diagnostic screening, is apparent. (See, e.g., Sarandakou et al., 1998; Kudoh et al., 1999; Ind et al., 1997).
As described in greater detail below, such additional markers might be usefully provided from within the "four-disulfide core" family of proteins, which comprises a heterogeneous group of small acid- and heat-stable molecules of divergent function and which includes human epididymal four-disulfide core protein, or "HE4" (Kirchhoff et al., 1991 Biol. Reprod. 45:350-357; Wang et al., 1999 Gene 229:101; Schummer et al., 1999 Gene 238:375). The conserved spacing of eight core cysteine residues in the amino acid sequences of four-disulfide core family member polypeptides is thought to direct the folding of these molecules into a compact and stable structure. Many of the members of the four-disulfide core family are protease inhibitors; however, for some family members, including HE4, no function has yet been definitively identified. Other members of the four-disulfide core family of proteins include Wp-protein, SLP-1, and ps20, and additional members of the four-disulfide core family of proteins have been isolated from several species. These proteins share several properties, including their small size and their heat- and acid-stable structure, which is stabilized by the four-disulfide core. These proteins are made by secretory cells, and are found in mucous secretions such as seminal plasma, milk, parotid, and cervical secretions.
The prototype molecule of the four-disulfide core family, Wp-protein, is also known as the whey phosphoprotein, and has been cloned (Dandekar et al., 1982 Proc. Natl. Acad. Sci. USA 79: 3987-3991). Whey phosphoprotein is expressed in milk at approximately 1-2 mg/ml, but is not expressed by breast carcinomas, where the gene is hypermethylated. No inhibitory activity towards proteases has been found for whey phosphoprotein. However, overexpression of the gene in transgenic animals impairs development of mammary alveolar cells (Burdon et al, 1991 Mechanisms Dev. 36: 67-74), suggesting an important role for this protein during lactation. The secretory leukocyte protease inhibitor (SLP-1), another four-disulfide core family protein, was cloned from human cervix uteri, but is also present in other mucus secretions including seminal plasma and parotid secretions (Heinzel et al, 1986 Eur. J. Biochem. 160: 61-67). SLP-1 is a two domain protein of 12 kDa that is a potent inhibitor of trypsin, chymotrypsin, elastase, and cathepsin G. The crystal structure of SLP-1 complexed with chymotrypsin has been published (Grutter et al, 1988 EMBO J. 7: 345-351). These data showed that SLP-1 domains can work independently and simultaneously to inhibit different proteases, and identified a small (8 amino acids) active site in domain two that binds to chymotrypsin.
Elafin is a single domain protein member of the four-disulfide core family that was isolated from human psoriatic skin to determine the amino acid sequence of this polypeptide (Wiedow et al, 1990 J. Biol. Chem. 265: 14791-14795). Elafin is a potent inhibitor of elastase, but does not exhibit apparent inhibitory activity toward other proteases such as trypsin, chymotrypsin, cathepsin G or plasmin. The amino acid sequence of elafin shows 38% homology with the C-terminal region (domain 1) of SLP-1. The gene encoding the ps20 protein was recently isolated from smooth muscle, and the ps20 protein was expressed by transfection of the gene into mammalian cells (Larsen et al, 1998 J. Biol. Chem. 273: 4574-4584). ps20 was found to inhibit growth of carcinoma cells, and ps20 has been referred to as a growth inhibitor; however, no direct functional activity such as inhibition of proteases has been described so far for this protein.
As noted above, no protease inhibitory activity has been identified for HE4, which was initially identified in epididymal eptithelial cells, although other small acid and heat stable proteinase inhibitors have been characterized from seminal plasma, and are thought to play a role in fertility by binding to spermatozoa and regulating the interaction of spermatozoa with the extracellular matrices of the egg (Fitz et al., in Proteases and Biological Controls, Reich, E., Rifkin, D., Shaw, E. (eds.), 1975 Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., pp. 737-766; Saling, 1989 Oxf. Rev. Reprod. Biol. 11: 339-388). HE4 cDNA was first isolated from human epididymis (Kirchhoff et al., 1991 Biol. Reprod. 45:350-357), and HE4 cDNA was later detected with high frequency in cDNA libraries constructed from ovarian carcinomas (Wang et al., 1999 Gene 229:101; Schummer et al., 1999 Gene 238:375).
For reasons given above, clearly there is a need for improved diagnostic markers and therapeutic targets for the detection and treatment of malignant conditions, such as carcinomas. The compositions and methods of the present invention overcome these limitations of the prior art by providing a method of screening for the presence of a malignant condition using antibodies specific for HE4 and/or HE4-related antigens to detect polypeptides that naturally occur in soluble form and/or on cell surfaces, and offer other related advantages.

This patent is subject to a terminal disclaimer.


An optical head includes a reflection type grating lens for dividing specified polarized lights into a reflected light and a diffracted light, a device for detecting a RF signal from the reflected light of the grating lens, and a device for detecting focusing and tracking error signals from the diffracted light of the grating lens. The grating lens consists of a plurality of domains having different optical properties respectively, so that the reflected and diffracted lights are obtained. The optical head further includes a total reflection prism to compensate a phase difference between polarized lights orthogonal to a grating groove of the grating lens and parallel thereto, and a polarizing prism for dividing the reflected light into two polarized lights orthogonal to each other in polarization thereof. Thus, a simple, miniaturized, and inexpensive optical head is obtained.

One conventional optical head comprises a collimating lens for collimating laser beam radiated from a semiconductor laser, a beam splitter for transmitting the laser beam therethrough and for reflecting beam reflected from an optical disk, a total reflection prism for reflecting the beam transmitted through the beam splitter and the optical disk-reflected beam to bend a light path thereof by 90.degree., a first focusing lens for focusing the beam on the optical disk, a 1/2 wavelength plate for rotating a polarization of the beam reflected from the beam splitter by 90.degree., a second focusing lens for focusing the beam transmitted through the 1/2 wavelength plate, a polarizing beam splitter for transmitting and reflecting the beam focused by the second focusing lens to produce two beams having polarizations orthogonal to each other, a two-divided photodetector for receiving the beam transmitted through the polarizing beam splitter, a cylindrical lens for transmitting the beam reflected by the polarizing beam splitter to produce beam of astigmatism wave surface, and a four-divided photodetector for receiving the astigmatism wave surface beam.
In the conventional optical head, a tracking error is detected in a push-pull method by using signals of the two-divided photodetector, a focusing error is detected in an astigmatism method by using signals of the four-divided photodetector, and a RF signals are obtained in accordance with a predetermined calculation based on the signals of the two and four-divided photodetectors, although the details thereof and operation will be explained in more detail later.
However, the conventional optical head has a relatively large size, for example, greater than 40.times.40.times.30 mm.sup.2, and thus this prevents miniaturization and lightening of the entire optical disk system.
Further, a push-pull method has generally been utilized for detecting a tracking error. Therefore, when the first focusing lens is moved in the direction normal to its optical axis by means of an actuator on the basis of the tracking error signals, the deviation may arise between the optical axis of the first focusing lens and the dividing line of the two-divided photodetector for detecting the tracking error to induce the imbalance between two quantities of light which are incident to two photodetector elements respectively. As a result, a direct current offset is generated in the tracking error signals, thereby resulting in a limited range of the tracking error controlling.
Furthermore, there is the interference among a RF signal, a focusing error signal and a tracking error signal to cause a servomotor to be unstable.
In addition, such a conventional optical head has a number of optical parts required to be optically polished, and thus this is expensive and their adjustments are complex and cumbersome.