The invention proposes a digital signal coding method including a step (E1) of analysing the digital signal (IM) into a plurality of frequency sub-bands, at least one first sub-band having a lower frequency and at least one second sub-band having a higher frequency, characterised in that it includes, for each second sub-band, the steps of:

The present invention concerns a digital signal coding device and method. It also concerns a decoding method and device corresponding to the coding method and device.
The purpose of coding is to compress the signal, which enables the digital signal to be transmitted, or respectively stored, thus reducing the transmission time or transmission rate, or respectively reducing the memory space used.
The invention is situated in the field of compression of digital signals with loss.
In a first aspect, breaking down a signal into frequency sub-bands before compressing it is known. The breakdown consists of creating, from the signal, a set of sub-bands which each contain a limited range of frequencies. The sub-bands can be of different resolutions, the resolution of a sub-band being the number of samples per unit length used for representing this sub-band. In the case of a digital image signal, a frequency sub-band of this signal can itself be considered to be an image, that is to say a bidimensional table of numerical values.
It should be noted that breaking down a signal into frequency sub-bands does not create any compression in itself, but makes it possible to decorrelate the signal so as to eliminate redundancy therefrom prior to the compression proper. The sub-bands are thus coded more effectively than the original signal.
A known method of coding a digital signal, in this case of a digital image, includes three main steps. The image is first of all broken down by a transformation into frequency sub-bands, then a scalar quantization of the coefficients thus obtained is performed. The quantized indices are finally coded by entropic coding without loss.
This method affords a high degree of compression of the signal. However, the ratio between the degree of compression and the coding error leaves room for improvement.
In the first aspect, the present invention aims to remedy the drawbacks of the prior art by providing a digital signal compression device and method which offers a high ratio of compression to distortion.
In second and third aspects, a known method of coding a digital signal, in this case of a digital image, is trellis coded quantization, which is described for example in the article entitled xe2x80x9cTrellis Coded Quantization of Memoryless and Gauss-Markov Sourcesxe2x80x9d by M. W. Marcellin and T. R. Fischer, which appeared in IEEE Transactions on Communications, Vol 38, Number 1, January 1990, as well as in the article xe2x80x9cUniversal Trellis Coded Quantizationxe2x80x9d by J. H. Kasner, M. W. Marcellin and B. R. Hunt, available by Internet at the address http://vail.ece.arizona.edu/Publications.html.
This method has the advantage of minimising the quantization error by virtue of the use of trellis coding.
In addition, in order to improve the ratio of compression to distortion, the inventors combined this method with another coding mode. In this case, blocks of the signal to be coded are allocated one or other coding mode, so as to select for each block the most appropriate coding mode, that is to say the one providing the highest ratio of compression to distortion.
Block here means a set of coefficients extracted from the signal in order to form a vector.
Coding by trellis coded quantization is applied to a series of blocks. For the coding to be optimal, it is necessary for the series to be fixed and known in advance. This means that, in order to allocate this mode to a given block in an optimum fashion, it would be necessary to know in advance all the blocks to which this code is allocated, and therefore to know the result of the allocation. There is therefore a difficulty in optimally allocating the coding modes to the blocks and consequently in obtaining the highest possible ratio of compression to distortion.
In the second aspect, the present invention aims to remedy the drawbacks of the prior art by providing a digital signal compression device and method which offers a high ratio of compression to distortion.
In the third aspect, the present invention aims to remedy the drawbacks of the prior art by providing a digital signal compression device and method which make it possible to allocate the trellis coded quantization coding mode to blocks formed in the signal, with great simplicity of implementation.
In a fourth aspect, the present invention aims to improve the first aspect of the invention, by applying a preprocessing between the step of breaking down into sub-bands and the coding step proper.
In the first aspect, the invention proposes a digital signal coding method, including the analysis of the signal in order to separate the pertinent information and the non-pertinent information, then the coding of the non-pertinent information according to a first coding mode which offers a high degree of compression, and coding of the pertinent information according to a second coding mode which limits distortion.
To this end, the invention proposes a digital signal coding method including a step of analysing the digital signal into a plurality of frequency sub-bands distributed in at least two different frequency bands, at least one first sub-band having a lower frequency and at least one second sub-band having a higher frequency,
characterised in that it includes, for each second sub-band, the steps of:
dividing the second sub-band into blocks,
selecting first blocks which are to be coded by setting to a predetermined value and second blocks which are to be coded by trellis coded quantization, according to a selection criterion,
linking the second blocks selected at the previous step in order to form a series of blocks,
coding the series of blocks by trellis coded quantization of a series of coefficients extracted from the second blocks of the second sub-band.
Correlatively, the invention proposes a digital signal coding device including means of analysing the digital signal into a plurality of frequency sub-bands distributed in at least two different frequency bands, at least one first sub-band having a lower frequency and at least one second sub-band having a higher frequency,
characterised in that it includes:
means of dividing each second sub-band into blocks,
means of selecting first blocks which are to be coded by setting to a predetermined value and second blocks which are to be coded by trellis coded quantization, according to a selection criterion,
means of linking the second blocks selected at the previous step in order to form a series of blocks,
means of coding the series of blocks by trellis coded quantization of a series of coefficients extracted from the second blocks of the second sub-band.
The breakdown into frequency sub-bands makes it possible to separate the pertinent information from the non-pertinent information. The non-pertinent information is then coded by setting to the predetermined value, which requires a nil transmission rate. Compression of the non-pertinent information is maximal.
It is thus possible to give a higher transmission rate to the pertinent information, present in the second blocks, which is thus coded more precisely. Distortion of the pertinent information is minimal, by virtue of the linking of the second blocks and their coding by trellis coded quantization.
Overall, the ratio of compression to distortion obtained is high.
The predetermined value is for example nil, so that, at decoding, blocks are constructed whose coefficients are nil.
According to a preferred characteristic, for each of the blocks the selection step includes the coding of the block by setting to the predetermined value and by a second coding mode, the comparison of the two coding modes according to the selection criterion and the selection of the coding by setting to the predetermined value if the block coded by setting to the predetermined value satisfies the selection criterion.
The selection is simple and rapid to implement. For example, the second coding mode is a scalar quantization of the coefficients of the block, or the second coding mode is a trellis coded quantization of a series of coefficients extracted from the blocks of the second sub-band. The latter case enables the structure of the coding device to be simplified, since the selection means then use the same coding as the means of coding the second blocks.
According to a preferred characteristic, the selection criterion minimises a weighted sum of the transmission rate and of the coding error caused by the coding of the block under consideration.
According to another preferred characteristic, an indicator is associated with each block in order to indicate whether or not the block under consideration is coded by setting to the predetermined value.
According to another preferred characteristic, the said at least one first sub-band is coded according to a third coding mode.
The coding device has means adapted to implement the above characteristics.
The invention also concerns a method of decoding a coded digital signal, the said signal including coded representations of blocks formed in frequency sub-bands of the original signal, each coded representation including at least one indicator representing a coding by setting to a predetermined value or a coding by trellis coded quantization of a series of coefficients extracted from blocks, characterised in that it includes the steps of:
reading the value of the indicator of each of the blocks,
decoding representations by formation of reconstructed blocks, all the coefficients of which have the predetermined value, or by trellis coded dequantization of the series of coefficients, as a function of the value of the respective indicator of each of the blocks.
Correlatively, the invention concerns a device for decoding a coded digital signal, the said signal including coded representations of blocks formed in frequency sub-bands of the original signal, each coded representation including at least one indicator representing a coding by setting to a predetermined value or a coding by trellis coded quantization of a series of coefficients extracted from blocks, characterised in that it has:
means of reading the value of the indicator of each of the blocks,
means of decoding representations by formation of reconstructed blocks, all the coefficients of which have the predetermined value, or by trellis coded dequantization of the series of coefficients, as a function of the value of the respective indicator of each of the blocks.
The decoding method and device make it possible to reconstruct the signal, for example in a receiving apparatus corresponding to a sending apparatus in which the signal has been coded according to the invention.
In the second aspect, the invention proposes an iterative optimisation of the allocation of coding by trellis coded quantization and of another coding mode, to blocks formed in a digital signal.
More precisely, the invention concerns a digital signal coding method, characterised in that it includes the steps of:
dividing the signal into blocks,
updating, at which a coding cost for each of the blocks is calculated, for at least a first coding mode and for a coding mode by trellis coded quantization,
allocating one of the coding modes to each of the blocks, according to an allocation criterion depending on the coding cost,
reiterating the updating and allocation steps, so as to satisfy a convergence criterion.
Correlatively, the invention proposes a digital signal coding device, characterised in that it has:
means of dividing the digital signal into blocks,
updating means, adapting to calculate a coding cost for each of the blocks, for at least a first coding mode and for a coding mode by trellis coded quantization,
means of allocating one of the coding modes to each of the blocks, according to an allocation criterion depending on the coding cost,
the updating and allocation means being adapted to be used iteratively, so as to satisfy a convergence criterion.
The method and device according to the invention make it possible to obtain a high ratio of compression to distortion. This is because, by virtue of the updating and allocation iterations, the invention improves the allocation of the coding modes to the blocks. The latter are thus coded in a more suitable fashion.
According to a preferred characteristic, the coding cost of each block is a weighted sum of the coding rate and error of the block under consideration. This coding cost is simple to implement and gives satisfactory results.
According to another preferred characteristic, at a given iteration, the calculation of the coding cost for the coding mode by trellis coded quantization of any block under consideration, to which the coding mode by trellis coded quantization has been allocated, includes the steps of:
linking the blocks to which the trellis coded quantization coding mode has been allocated, in order to form a series of blocks,
coding the series of blocks by trellis coded quantization of a series of coefficients extracted from the linked blocks,
extracting the coding rate and error from the block under consideration.
This calculation makes it possible to precisely determine the coding cost as defined.
According to a preferred characteristic, at a given iteration, the coding cost for the trellis coded quantization coding mode for any block under consideration, to which the first coding mode was allocated, is the coding cost for the trellis coded quantization coding mode for the block calculated at the time of the last iteration during which the trellis coded quantization coding mode was allocated to the block.
According to a preferred characteristic, the allocation criterion minimises the coding cost. Allocating a coding mode to a block amounts to comparing two coding costs and selecting the coding mode associated with the lowest cost.
According to a preferred characteristic, the coding method also includes an initialisation step at which the trellis coded quantization coding mode is allocated to each of the blocks. This step makes it possible to calculate a first trellis coded quantization coding cost for each of the blocks.
According to a preferred characteristic, the convergence criterion is satisfied when the same coding modes are respectively allocated to the same blocks at two successive iterations of the allocation step. This criterion is reliable whilst being simple to implement.
According to a preferred characteristic, an indicator is associated with each block in order to indicate which coding mode is allocated to each block. This indicator is then used at the time of decoding of the blocks.
According to a preferred characteristic, the first coding mode is a setting of the coefficients of the block to a predetermined value. This coding mode has the advantages of being a good approximation of the blocks containing little information, being very simple to implement and of having an associated coding rate which is nil.
The invention also concerns a method of decoding a coded digital signal, the said signal including coded representations of blocks formed in the original signal, each coded representation including at least one indicator representing either a first coding mode or a trellis coded quantization coding mode, characterised in that it includes the steps of:
reading the value of the indicator,
decoding the coded representations, according to the value of the respective indicator.
Correlatively, the invention concerns a device for decoding a coded digital signal, the said signal including coded representations of blocks formed in the original signal, each coded representation including at least one indicator representing either a first coding mode or a trellis coded quantization coding mode, characterised in that it includes:
means of reading the value of the indicator,
means of decoding the coded representations, according to the value of the respective indicator.
The decoding method and device enable the signal to be reconstructed, for example in a receiving apparatus corresponding to a sending apparatus in which the signal was coded according to the invention.
The invention also relates to a digital signal processing apparatus, having means of implementing the coding method, or the decoding method, or including the coding device, or the decoding device, as disclosed above.
The advantages of the coding device, of the decoding device and method and of this digital signal processing apparatus are identical to those of the coding method previously disclosed.
In the third aspect, the invention proposes an iterative optimisation of the allocation of coding by trellis coded quantization and of another coding mode, to blocks formed in a digital signal.
More precisely, the invention concerns a digital signal coding method, characterised in that it includes the steps of:
dividing the signal into blocks,
updating, at which a coding cost for each of the blocks is calculated, for at least a first coding mode and for a coding mode by scalar quantization,
allocating one of the coding modes to each of the blocks, according to an allocation criterion depending on the coding cost,
reiterating the updating and allocation steps, so as to satisfy a convergence criterion,
linking the blocks to which the scalar quantization coding mode was allocated, in order to form a series of blocks,
coding the series of blocks by trellis coded quantization of a series of coefficients extracted from the blocks in the series.
Correlatively, the invention proposes a digital signal coding device, characterised in that it has:
means of dividing the digital signal into blocks,
updating means, adapting to calculate a coding cost for each of the blocks, for at least a first coding mode and for a coding mode by scalar quantization,
means of allocating one of the coding modes to each of the blocks, according to an allocation criterion depending on the coding cost,
the updating and allocation means being adapted to be used iteratively, so as to satisfy a convergence criterion,
means of linking the blocks to which the scalar quantization coding mode was allocated, in order to form a series of blocks,
means of coding the series of blocks by trellis coded quantization of a series of coefficients extracted from the blocks in the series.
By virtue of the method and device according to the invention, the allocation of scalar quantization to the blocks constitutes a good approximation of the allocation of the trellis coded quantization coding mode and has the advantage of being simple and rapid to implement.
In addition, the method and device according to the invention make it possible to obtain a high ratio of compression to distortion. This is because, by virtue of the updating and allocation iterations, the invention improves the allocation of the coding modes to the blocks. The latter are thus coded in a more suitable fashion.
According to a preferred characteristic, the coding cost of each block is a weighted sum of the coding rate and error of the block under consideration. This coding cost is simple to implement and gives satisfactory results.
According to a preferred characteristic, at a given iteration, the calculation of the coding cost for the coding mode by scalar quantization of any block under consideration, includes the steps of:
grouping the blocks to which the scalar quantization coding mode has been allocated, in order to form a group of blocks,
coding the group of blocks by scalar quantization,
determining an entropic coder adapted to the distribution of the symbols resulting from the scalar quantization of the blocks of the group,
entropic coding of the quantized block under consideration, by means of the previously determined entropic coder,
extracting the coding rate of the block under consideration.
According to a preferred characteristic, at a given iteration, the calculation of the coding cost for the scalar quantization coding mode for any block under consideration includes the step of determining the distortion associated with the coding of the block under consideration by scalar quantization.
The coding rate and distortion for the scalar quantization coding mode are determined with calculations which are simple and rapid to make.
According to another preferred characteristic, the allocation criterion minimises the coding cost. Allocating a coding mode to a block amounts to comparing two coding costs and selecting the coding mode associated with the lowest cost.
According to a preferred characteristic, the method also includes an initialisation step at which the scalar quantization coding mode is allocated to each of the blocks. This step makes it possible to calculate a first scalar quantization coding cost for each of the blocks.
According to a preferred characteristic, the convergence criterion is satisfied when the same coding modes are respectively allocated to the same blocks at two successive iterations of the allocation step. This criterion is reliable whilst being simple to implement.
According to a preferred characteristic, an indicator is associated with each block in order to indicate which coding mode is allocated to each block. This indicator is then used at the time of decoding of the blocks.
According to a preferred characteristic, the first coding mode is a setting of the coefficients of the block to a predetermined value. This coding mode has the advantages of being a good approximation of the blocks containing little information, of being very simple to implement and of having an associated coding rate which is nil.
The invention also relates to a digital signal processing apparatus, having means of implementing the coding method, or including the coding device, as disclosed above.
The advantages of the coding device and of this digital signal processing apparatus are identical to those of the coding method previously disclosed.
In the fourth aspect, a preprocessing is applied between the step of breaking down into sub-bands and the coding step proper.
The invention proposes a digital signal coding method including the analysis of the signal in order to separate the pertinent information and the non-pertinent information, and then the preprocessing of the non-pertinent information according to a first preprocessing mode, and preprocessing of the pertinent information according to a second preprocessing mode. The preprocessing modes are determined so as to facilitate the coding of the preprocessed signal.
To this end, the invention proposes a digital signal coding method including a step of analysing the digital signal into a plurality of frequency sub-bands distributed in at least two different frequency bands, at least one first sub-band having a lower frequency and at least one second sub-band having a higher frequency,
characterised in that it includes, for each second sub-band, the steps of:
dividing the second sub-band into blocks,
selecting first blocks and second blocks, according to a selection criterion,
preprocessing the first blocks by applying a first preprocessing mode,
preprocessing the second blocks by applying a second preprocessing mode,
coding the sub-band including the preprocessed blocks, by applying a third coding mode.
Correlatively, the invention proposes a digital signal coding device including means of analysing the digital signal into a plurality of frequency sub-bands distributed in at least two different frequency bands, at least one first sub-band having a lower frequency and at least one second sub-band having a higher frequency,
characterised in that it includes:
means of dividing each second sub-band into blocks,
means of selecting first blocks and second blocks, according to a selection criterion,
means of preprocessing the first blocks by applying a first preprocessing mode,
means of preprocessing the second blocks by applying a second preprocessing mode,
means of coding the sub-band including the preprocessed blocks, by applying a third coding mode.
The method and device according to the invention afford a high ratio of compression to distortion.
This is because the selection separates the pertinent or useful information from the non-pertinent or parasitic information, such as background noise for example. The preprocessing then reduces the influence of the non-pertinent information, by virtue of which the coding is more effective.
Overall, the ratio of compression to distortion obtained is high.
According to a preferred characteristic, for each of the blocks, the selection step includes:
the coding of the block by a first coding mode and by a second coding mode,
the comparison of the two coding modes according to the selection criterion, and
selecting the first and second blocks according to the result of the comparison.
The selection is simple to implement.
According to another preferred characteristic, the selection criterion minimises a weighted sum of the transmission rate and coding error caused by the coding of the block in question.
This criterion makes it possible to distinguish the blocks containing pertinent information and the blocks containing parasitic information.
According to preferred characteristics, the first coding mode is a setting to zero of the coefficients of the block, and the second coding mode is a scalar quantization of the coefficients of the block. The second coding mode can also be a coded trellis quantization of a series of coefficients extracted from the block, or a vector quantization of the block.
These coding modes are simple and rapid to implement.
According to other preferred characteristics, the first preprocessing mode is a zeroing of the coefficients of the block, and the second preprocessing mode is identity. Thus the parasitic information is replaced by zeroed blocks, whilst the pertinent information is not modified.
According to a preferred characteristic, the third coding mode is identical to the second coding mode, which simplifies the implementation of the invention.
According to preferred characteristics, the third coding mode is a trellis coded quantization of a series of coefficients extracted from the preprocessed blocks, or a scalar quantization of the sub-band, or also a vector quantization of the sub-band.
According to another preferred characteristic, the said at least one first sub-band is coded according to a fourth coding mode.
The coding device has means adapted to implement the above characteristics.
The invention also concerns an information storage means, which can be read by a computer or by a microprocessor, whether or not integrated into the device, optionally removable, and which stores a program implementing the coding or respectively decoding method.
The characteristics and advantages of the present invention will emerge more clearly from a reading of a preferred embodiment illustrated by the accompanying drawings, in which:
FIG. 1 depicts a block diagram of a first embodiment of a digital signal coding device according to the invention;
FIG. 2 depicts a circuit for breaking down into frequency sub-bands, included in the device of FIG. 1;
FIG. 3 depicts a digital image to be coded by the coding device of FIG. 1;
FIG. 4 depicts an image broken down into sub-bands by the circuit of FIG. 2;
FIG. 5 depicts an image broken down into sub-bands and then divided into blocks;
FIG. 6 depicts a circuit for coding by trellis coded quantization, included in the device of FIG. 1;
FIG. 7 depicts a block diagram of a first embodiment of a decoding device according to the invention;
FIG. 8 depicts an algorithm for coding a digital signal according to the first embodiment of the invention;
FIG. 9 depicts an algorithm for decoding a digital signal according to the first embodiment of the invention;
FIG. 10 is a block diagram of a second embodiment of a digital signal coding device according to the invention;
FIG. 11 is a block diagram of a second embodiment of a decoding device according to the invention;
FIG. 12 is a digital signal coding algorithm according to the second embodiment of the invention;
FIG. 13 is a digital signal decoding algorithm according to the second embodiment of the invention;
FIG. 14 is a block diagram of a third embodiment of a digital signal coding device according to the invention;
FIG. 15 is a block diagram of a third embodiment of a decoding device according to the invention;
FIG. 16 is a digital signal coding algorithm according to the third embodiment of the invention;
FIG. 17 is a digital signal decoding algorithm according to the third embodiment of the invention;
FIG. 18 is a block diagram of a fourth embodiment of a digital signal coding device according to the invention;
FIG. 19 is a block diagram of a fourth embodiment of a decoding device according to the invention;
FIG. 20 is a coding algorithm for a digital signal according to the fourth embodiment of the invention;
FIG. 21 is a decoding algorithm for a digital signal according to the fourth embodiment of the invention.

Digital signal coding and decoding based on subbands

Abstract: dividing (E4) the second sub-bands into blocks (Bp,n),

Abstract: selecting (E9) first blocks which are to be coded by setting to a predetermined value and second blocks which are to be coded by trellis coded quantization, according to a selection criterion,

Abstract: linking (E16) the second blocks selected at the previous step in order to form a series of blocks,

Abstract: coding (E17) the series of blocks by trellis coded quantization of a series of coefficients extracted from the second blocks of the second sub-band.


A presence detection system for level crossing or to detect a target at the intersection of any paths is described herein. The system comprises an ultrasound sensor array positioned at the intersection of the first and second paths for defining a detecting area thereon and for emitting a first trigger signal when the body is in the detecting area; and a controller coupled to the ultrasound sensor array for receiving the first trigger signal and for emitting an alarm signal indicative of the first trigger signal. The sensor array detects the presence of a target by creating acoustic virtual lines which form between emitter and receiver or transducer and reflectors and/or by deploying conical or parallel detecting beams and which can be used, for example to measure the distance between each sensor forming the array and the target. The sensor array can deploy beams or acoustic lines in several plans and therefore allow detecting penetration above the conventional railway crossing barriers.

Security at level crossings has been an issue since the first trains have set wheels on the face of the earth. In addition to warning lights and audio signals, one of the first, and to this day, still widely and almost uniquely used solution, is to provide pivotable barriers on both sides of the railway track. As it is believed to be well known, such barriers are automatically lowered before the passage of a train to block the path on both sides and then raised after the train is passed.
Even though this gate system has been found effective to visually alert travellers of the incoming passage of a train at a level crossing, it does not alert of the presence of a vehicle already positioned on the railway before the lowering of the gates or of a smaller vehicle or a pedestrian that could have decided to ignore the gates and accompanying visual and sound alarm signals and still cross the track.
A presence detection system for level crossing and more generally to path crossing allowing additional functionalities and flexibilities than such a system is therefore desirable.

Presence detection system for path crossing


In a method for robot-controlled cutting of workpieces to be joined by laser radiation, a first workpiece is arranged in vicinity of a second workpiece in a first position. A laser is focused onto the first workpiece. A contour of the first workpiece is cut with the laser beam; this contour is to be assembled and joined with the second workpiece. During cutting, a first spacing of a focal point of the laser beam from the second workpiece is repeatedly determined in a distance direction that is identically oriented during cutting and is adjusted to a direction of assembling the first and second workpieces. During cutting, a second spacing of a processing point of the laser beam from the second workpiece is maintained at a constant value.

The invention relates to a method for robot-controlled cutting of workpieces to be joined by means of laser radiation that is being focused onto a first workpiece whose cut contour is assembled and joined with a second workpiece.
Such a method is known in general. It is carried out conventionally with buckling arm robots that, based on their low adjusting frequency of approximately 10 Hz for all axes, have significant impression for cutting and welding. In addition, there are impressions as a result of the mechanical manufacture of the robot parts, of the employed encoders, and as a result of the machine-internal coordinate system that deviates from an ideal coordinate system. Moreover, dynamically caused impressions of the focal point position are present. Depending on the gear configuration and amount of teach points, a path repetition precision of only approximately +/−0.1 to +/−0.4 mm in any of the three coordinate directions is achieved for approximately 5 m/min. The resulting precision range is +/−0.1×sheet metal thickness. It would be necessary to bring the precision for cutting sheet metal by means of robots to a precision of +/−0.05 ×sheet metal thickness in order to prevent a seam collapse for welding without welding additives. Moreover, radii of less than 50 mm cannot be welded with the known method because the robot control correction is too slow.
Moreover, it is known (IP 901 875 A1) to control a laser beam by means of one or several moved mirrors on a robot hand such that this robot hand is maintained in a predetermined position during machining. The focus can then be positioned with higher precision on the workpiece in comparison to the robot control. The processing width to be achieved of approximately 50 mm is however completely unsatisfactory, in particular, for manufacturing tube frame structures in the automobile construction sector.

Method and device for the robot-controlled cutting of workpieces to be assembled by means of laser radiation


Methods and apparatus, including computer program apparatus, implementing techniques for processing a formatted computer-readable source document to create a style sheet. The techniques include partitioning the formatted text into multiple groups of words; deriving an element style for a predefined element that is assigned to two or more groups of words; and creating an electronic document including a style sheet defining the element style.

The present invention relates to generating style sheets for use with markup language documents.
Style sheets are used to give a common look to a collection of documents. A style sheet contains codes (generally but not necessarily found in one document) that; specify formatting for the parts of a document—such as body text, headings, list items, quotes, and so on. Generally, style sheets and documents are in electronic form. With style sheets, the content of a document can be separated from its presentation.
Cascading Style Sheets (CSS) is a style sheet mechanism that extends the HyperText Markup Language (HTML). CSS enables the precise placement of HTML document elements and the precise selection of fonts in HTML documents. CSS can be used by a Web (World Wide Web) page designer to give a common look and feel to large number of documents.
The Cascading Style Sheets, level 1 (CSS1) standard is a W3C (World Wide Web Consortium) Recommendation. It describes the CSS language as well as a simple visual formatting model. The CSS, level 2 (CSS2) standard builds on CSS1 and adds support for media-specific style sheets (e.g., printers and aural devices), downloadable fonts, element positioning and tables. CSS1 is a simple style sheet mechanism that allows authors and readers to attach style (e.g., fonts, colors and spacing) to HTML documents. The CSS1 language is human readable and writable, and expresses style in common desktop publishing terminology. One of the fundamental features of CSS is that style sheets cascade; authors can attach a preferred style sheet, while the reader may have a personal style sheet to adjust for human or technological handicaps. CSS2 is a style sheet language that allows authors and users to attach style (e.g., fonts, spacing, and aural cues) to structured documents (e.g., HTML documents and XML applications).
Other style sheet languages exist as well. For example, the Extensible Stylesheet Language (XSL) Specification, a work in progress of the W3C, defines a language for expressing stylesheets. An XSL stylesheet specifies the presentation of a class of XML documents by describing how an instance of the class is transformed into an Extensible Markup Language (XML) document that uses the formatting vocabulary.
Systems exist that can generate a style sheet from a source document. Generally, such systems are limited to particular file formats, i.e., electronic representations of the source document, or generate style sheets that are specific to the source document and therefore not easily usable by a human user for preparing new documents.


[OBJECTS]

In recent years, active uses of electronic apparatuses including personal computers and cellular phones as well as electrically-powered automobiles, and development in natural (renewable) energy storing technique have invoked increasing demand for high-performance batteries of a high level of safety and a long service life. Conventionally, some lithium ion secondary batteries employ an organic electrolyte layer produced by dissolving a lithium salt in an organic solvent. However, such batteries having a liquid-based organic electrolyte layer have hazards, including leakage of organic solvent, flashing, and explosion, which are not preferred from safety aspects. In order to ensure a high level of safety, complete-solid batteries have been extensively developed in recent years. The complete-solid batteries employ a solid electrolyte layer instead of a liquid-base organic electrolyte layer, along with other battery elements formed of a solid.
The complete-solid batteries, having a ceramic electrolyte layer, are free from liquid leakage or flashing, ensuring high safety. Also, the complete-solid batteries may adapt a simpler casing as compared with a casing of a lithium ion secondary battery employing a liquid-base organic electrolyte layer, whereby battery elements are stacked. The thus-realized small-scale batteries can provide an enhanced energy density per unit volume or weight. Among such complete-solid batteries, a complete-solid lithium ion secondary battery having an electrode containing metallic lithium is envisaged to realize high energy density. The complete-solid lithium ion secondary batteries must employ an electrolyte layer formed of a specific material which is stable to highly reactive metallic lithium. Under such circumstance, a ceramic material having a garnet-type crystal structure is a promising material for producing solid electrolyte layer having high chemical stability.
Among such electrolyte layer materials, a candidate is a ceramic material having a garnet-type crystal structure represented by Li7La3Zr2O12 (hereinafter referred to as LLZ). LLZ mainly has cubic and tetragonal crystal structures. It is reported that cubic-type LLZ exhibits high ion conductivity when a specific element thereof is substituted with another element.
For example, Patent Documents 1 and 2 disclose that LLZ, which intrinsically has low density and an unmeasurably low Li ion conductivity, can be recovered as stable pellets and exhibits high Li ion conductivity, when aluminum (Al) is added to the initial LLZ components (Patent Document 1; claim 1, [0009] and [0076], Patent Document 2; claim 1, [0007] and [0019]).
Patent Document 3 discloses that, through addition of an appropriate amount of Al to a garnet-type lithium-ion-conductive oxide, the conductivity (Li ion conductivity) of the oxide increases, and the activation energy of conductivity decreases, to thereby reduce a variation in conductivity with temperature (Patent Document 3; claim 1 and [0006]).
Patent Document 4 discloses that the Li ion conductivity of an LLZ ceramic material can be enhanced by partially substituting Zr with niobium (Nb) and/or tantalum (Ta) (Patent Document 4; claim 1 and [0009]).
Patent Document 5 discloses that incorporation of Al and Mg as additional elements into a garnet-type LLZ solid electrolyte ceramic material can provide a high-density and high-strength LLZ solid electrolyte ceramic material, while uneven firing, cracking, formation of defects (e.g., pores), anomalous grain growth, etc. are suppressed or prevented (Patent Document 5; claim 1 and [0011]).
Patent Document 6 discloses that, through substituting La site elements of a garnet-type Li—La—Zr oxide with Sr, Ca, or the like and Zr site elements thereof with Nb or the like, a drop in conductivity (Li ion conductivity) of the oxide can be prevented to a maximum extent, and the firing energy of the oxide can be further reduced (Patent Document 6; claim 1 and [0008]).
Patent Document 7 discloses a solid ion conductor having a garnet-like crystal structure, represented by a stoichiometric composition L7+XA3G3−XZr2O12 [wherein L represents an independent monovalent cation; A represents an independent divalent cation; G represents an independent trivalent cation; 0≤X≤3; and O represents a partially or completely divalent or trivalent anion which may optionally be substituted with, for example, N3−] (Patent Document 7; claim 4). The Examples of the above specification disclose that the total conductivity of Li7La3Zr2O12 at room temperature is higher than that of other lithium ion conductors (Patent Document 7; [0052]).
Patent Document 8 discloses "a garnet-type lithium-ion-conductive oxide represented by formula: Li5+XLa3(Zrx,A2−X)O12 (wherein A represents at least one element selected from the group consisting of Nb and Ta; and 1.4≤X<2)" (Patent Document 8; claim 1). Patent Document 8 discloses that the garnet-type lithium-ion-conductive oxide exhibits higher conductivity as compared with a known oxide, Li7La3Zr2O12, while the chemical stability and potential window are the same therebetween (Patent Document 8; e.g., [0010]).

Lithium-ion-conductive ceramic material, lithium-ion-conductive ceramic sintered body, and lithium battery

Abstract: [OBJECTS]

Abstract: An object of the present invention is to provide a lithium-ion-conductive ceramic material having a target ion conductivity, while suppressing production cost. Another object is to provide a high-performance lithium battery, while suppressing production cost, by virtue of having the lithium-ion-conductive ceramic material.

Abstract: The lithium-ion-conductive ceramic material contains Li, La, and Zr, as well as at least one of Mg and A (wherein A represents at least one element selected from the group consisting of Ca, Sr, and Ba) and which has a garnet-type crystal structure, wherein the elements contained in the ceramic material satisfy the following mole ratio conditions (1) to (3): (1) 1.33≤Li/(La+A)≤3; (2) 0<Mg/(La+A)≤0.5; and (3) 0<A/(La+A)≤0.67, and a lithium battery employing the ceramic material.


A new cleaning chemistry based on bis-choline and tris-choline compounds, such as their hydroxides, is provided in order to address the removal of photoresist and flux while minimizing any etching of the substrate.

Cleaning solvents are used throughout industry. These solvents are made from various organic and inorganic materials forming compositions differing in functionality and effectiveness. In order for cleaning solvents to be effective, the cleaning solvent, the material to be removed, and the surrounding material or substrate must be examined to insure that the material or residue to be removed can be dissolved, solvated, or removed by the cleaning solvent without damaging the surrounding materials. Several factors, such as pH, polarity, chemical reactivity, and chemical compatibility must be considered when selecting a cleaning solvent. Other factors must also be considered when utilizing cleaning solvents, such as environmental regulations, safety concerns, and cost.
Choline and other solvents have been utilized for a variety of processes in industry. These choline compositions have been used, for example, in the microprocessor industry, and the automotive industry. In these and other industries, there have been problems associated with the use of choline compounds and choline derivative compounds.
In the microprocessor industry, various materials are utilized throughout a device. Typically, many of the base structures are made of silicon or quartzware (e.g. silicon dioxide). Also present in this industry are metal products such as copper, aluminum, gold, and silver. The process of building these intricate structures is often so small that mechanical means of construction cannot be utilized. A photolithographic process is often used to construct the pattern on the microcircuit. This process utilizes photoresist materials on an insulating film or a conductive metal film (such as an oxide film, a copper film, or aluminum alloy film), coated on a substrate, to create the pattern on the microcircuit. These photoresists are used as masking materials to delineate patterns onto a substrate so that the patterns can be subsequently etched or otherwise defined into the substrate. A spin station is used to apply the photoresist on the surface of the wafer by dispensing the photoresist on the wafer. The spin station includes a member such as a spin chuck for holding and rotating the wafer and a spindle connected to a motor for rotating the spin chuck. The spin station also includes a catch cup and a dispensing member for applying the photoresist to the wafer. During the spin-coating process, the spinning of the chuck quickly rotates the wafer, which spreads the photoresist across the surface of the wafer and rids the excess photoresist off the wafer. The final steps in preparing the substrate then involve removing the unexposed resist material and any etching residue, if etching was used, from the substrate. It is critical that all of the photoresist, flux and other debris and residue be removed to provide a wafer having sufficient integrity for subsequent use of the wafer in microcircuitry.
Additionally, plasma etching, reactive ion etching, or ion milling are also used to define the pattern in a substrate. During such etching processing, an organometallic by-product compound can be formed on the sidewall of the substrate material. A recently developed technique effective for photoresist removal is plasma oxidation, also known as plasma ashing. However, while this process is effective for removing a photoresist, it is not effective for removing the organometallic polymer formed on the sidewall of the substrate during the etching process.
Polyimides are also used in microelectronics as fabrication aids, passivants, and inter-level insulators. The use of a polyimide as a fabrication aid includes application of the polyimide as a photoresist, planarization layer in a multi-level photoresist scheme and as an ion implant mask. In these applications, the polymer is applied to a wafer or substrate, subsequently cured or patterned by a suitable method and removed after use. Many conventional strippers are not sufficiently effective in removing the polyimide layer once the polyimide has been subjected to curing. The removal of such polyimides is normally accomplished by boiling the substrate in hydrazine or in oxygen plasma.
The catch cups of the photolithographic process must also be cleaned. Clean air is directed through the spin station to control the temperature and humidity of the environment in the catch cup. Because the photoresist typically includes a high concentration of volatile solvents, the photoresist will quickly dry and adhere to the inner walls of the catch cup before it can drain from the bottom of the catch cup. The resist will deposit on the inner walls of the top, the bottom, and the shield of the catch cup. After even a few processing cycles, excessive amounts of photoresist can begin to accumulate on the inner walls of the catch cup. This build up of photoresist on the inner walls of the catch cup can alter the desired air flow characteristics around the wafer and can lead to wafer contamination and poor coating uniformity.
Typically, cleaning the catch cups has been by removing the catch cup from the spin station and manually applied cleaning fluids to the contaminated inner surfaces of the catch cup. Another method of cleaning the catch cups involves a system having two rotating catch cups; one of the catch cups actively catches excess photoresist while a cleaning solvent is dispensed on the contaminated walls of the second catch cup. The solvents used in these processes often poses a safety concern, as they may be health or environmental hazards. These hazards increase overall costs of cleaning by increasing materials handling costs and safety equipment costs.
Traditionally, the photoresist material was used to create interconnects made of aluminum or aluminum alloys isolated by dielectric material, for example silicon dioxide. More recently developed interconnects use copper as the conducting material and low-k dielectric material (a dielectric, having a dielectric constant, ε, smaller than the dielectric constant of silicon dioxide). To integrate copper and eventually aluminum, the pattern is transferred from the photoresist through the dielectric. The gaps are then filled up by the conducting layer. This process is called damascene and can integrate either one level of interconnect only (single damascene) or both the horizontal interconnects and the vertical interconnects called vias (dual damascene). Vias always open atop the underlying metal lines and good cleanliness of the via is required in order to minimize electrical resistance along the interconnect.
Various processes have been developed to build those structures, as disclosed, for example, in U.S. Pat. Nos. 5,739,579; 5,635,423; 5,705,430; and 5,686,354, which can include optional layers into the dielectric stack but all those processes have in common:    that the via needs to be cleaned from all post etch residues, without damaging the metal, before the second metal layer can be deposited,    that the whole dielectric material needs to be cleaned from copper compounds back-sputtered onto the sidewall and top surface on the underlying copper during the final part of the etching, called "opening".    that the transfer of the wafer from the etching chamber to the ambient air for further processing creates oxidized copper compounds CuO or Cu2O that need to be cleaned to minimize the via resistance.
It has been described previously to clean materials used in the semiconductor industry by including a small amount (generally between 1% and 5% weight) of choline and other compounds to remove or avoid adsorption of metal impurities (U.S. Pat. Nos. 4,239,661 and 4,339,340, and Japanese Patent Nos. 6-163495, 6-041773, 2-275631, and 1-191450). Choline base is also well known for its use as developer of positive working photoresist (U.S. Pat. Nos. 4,294,911 and 4,464,461). It has also been recognized that choline base can act as a etching agent of metal for thin film layer definition (Japanese Patent No. 62-281332 and U.S. Pat. No. 4,172,005) and that adding choline atoms into an etching chamber when etching copper helps to lower the process temperature and hence minimize copper oxidation. U.S. Pat. No. 5,846,695 discloses aqueous solutions of quaternary ammonium hydroxides, including choline, in combination with nucleophilic amines and sugar and/or sugar alcohols, for removal of photoresist and photoresist residues in integrated circuit fabrication.
During the formation and utilization of these wares, excess coatings and/or flux from the manufacturing process can remain on the quartzware. In electronic applications the effectiveness of the production cleaning process can directly affect the reliability of the finished device. For example, a clean surface is necessary to ensure good bonding and coating, chemical contaminants can cause corrosion, and particulate matter may provide conductance paths resulting in current leakage or electrical short circuits. These are usually time related failure mechanisms that occur after the device has been put into use. The removal of these fluxes has posed a lasting difficulty for the microprocessor industry for many reasons, including the presence of various types of materials all having different reactivities and tolerances for chemical solvents. The removal of solder-flux from printed circuit boards is essentially one of washing the board with either an organic-solvent or water based cleaning solution. With the increasing limitations on organic-solvent-systems that are imposed by environmental considerations, the water-based-systems are starting to dominate flux-removal processes. Whichever process is used, it is generally involves a dissolving/dilution/flushing process where the flux is dissolved and dispersed within the flushing-solvent through the action of one or more surface-active agents.
Existing cleaning compositions used in the semiconductor industry are not suitable for the following reasons:    amine containing products are not compatible with copper and dissolve the metal at the exposed areas;    dilute hydrofluoric acid solutions (DHF) remove the sidewall polymer and CuO compounds by aggressively attacking the sidewall of the dielectric and hence change the designed dimensions of the device. Furthermore those solutions are ineffective for cleaning Cu2O or CFx compounds.
Optionally the photoresist might or might not be removed before the copper is exposed. Using traditional photoresist removal techniques is not ideal for the following reasons:    an oxygen plasma step will oxidize the copper to the CuO and Cu2O states, which will increase the via resistance,    an oxygen plasma step will be detrimental to organic dielectric material, if used, by etching the material in an uncontrolled manner.    a traditional solvent used to remove photoresist such as, for example, products containing N-methyl pyrrolidone, might require an extra cure step to recover the dielectric constant and properties of an organic dielectric.
Copper has been chosen because it is a relatively inexpensive metal with better conductivity (ρ=1.7 Ω·cm) than aluminum (ρ=2.7 Ω·cm). However the main drawbacks of this material are first its high diffusivity into silicon, introducing risk of a killing defect in the front end device, and second the difficulty to dry etch it and integrate it in traditional processes. In addition, copper does not form an oxide passivation layer under ambient conditions (as aluminum does), making this metal very difficult to work with.
On the gap-fill side, the industry's choice of low-k dielectric material has not yet emerged, though various candidates have been suggested. It has been shown that a general trend to achieve lower dielectric constant is to use material with less silicon and more carbon. There is then a logical evolution from the inorganic materials (such as SiO2 [ε=4], SiOF [ε=3.5]) to silsesquioxane types of material (such as HSQ, MSQ [3.0<ε<3.5]), towards organic material, such as benzyl cyclobutane (BCB) or silicon low k (SiLK) [ε=2.7]), with the ultimate low-k value being reached with air gaps.
We have seen over the past few years, the emergence of the damascene type of structure in which the design is etched into a dielectric layer, which is then filled with conducting wires and planarized. Dual damascene structures have the advantage of incorporating both lines and vias in one deposition step; this reduces the number of process steps and is therefore cost effective. However the main reason for the emergence of such structures nowadays is the fact that this is the easiest way to introduce copper.
Variations of the dual damascene structure exist, incorporating a series of layers for process purposes such as anti-reflective coatings, adhesion promoters, moisture barriers, diffusion barriers, polishing stops, buried etch mask and so on. The choice of whether those have to be used or not and what material (SiOxNy or SixNy) should be used for them often depend upon the final choice of the low-k material.
Known photoresist stripper compositions containing a combination of a polar solvent and an amine compound include:
1. U.S. Pat. No. 4,403,029 describes alkaline/solvent mixtures useful as photoresist strippers, but not necessarily cleaners, that include dimethylacetamide or dimethylformamide and alkanolamines.
2. U.S. Pat. Nos. 4,428,871, 4,401,747, and 4,395,479 describe cleaners containing 2-pyrrolidone, dialkylsulfone and alkanolamines.
3. U.S. Pat. No. 4,744,834 describes cleaners containing 2-pyrrolidone and tetramethylammonium hydroxide. Such stripping compositions, however, have only proven successful in cleaning "sidewall polymer" from the contact openings and metal line etching in simple microcircuit manufacturing involving a single layer of metal when the metal structure involves mainly Al—Si or Al—Si—Cu and the residue that contains only an organometallic compound with aluminum.
4. U.S. Pat. No. 4,617,251 teaches a positive photoresist stripping composition containing (A) selected amine compound (e.g., 2-(2-aminoethoxy)-ethanol; 2-(2-aminoethylamino)-ethanol; and mixtures thereof) and (B) selected polar solvents (e.g., N-methyl-2-pyrolidinone, tetrahydrofurfuryl alcohol, isophorone, dimethyl sulfoxide, dimethyl adipate, dimethyl glutarate, sulfolane, gamma-butyrolactone, N,N-dimethylacetamide and mixtures thereof). The reference further teaches that water as well as dyes or colorants, wetting agents, surfactants and antifoamers may be added into this composition.
5. U.S. Pat. No. 4,770,713 teaches a positive photoresist stripping composition containing (A) a selected amide (e.g., N,N-dimethyl acetamide; N-methyl acetamide; N,N-diethyl acetamide; N,N-dipropyl acetamide; N,N-dimethyl propionamide; N,N-diethyl butyramide and N-methyl-N-ethyl propionamide) and (B) selected amine compound (e.g., monoethanolamine, monopropanolamine, methyl-aminoethanol). The patent also teaches this stripper may optionally contain a water miscible nonionic detergent (e.g., alkylene oxide condensates, amides and semi-polar nonionics).
6. U.S. Pat. No. 4,824,763 teaches positive-working photoresist stripping composition containing (A) triamine (e.g., diethylene-triamine) and (B) a polar solvent (e.g., N-methyl-2-pyrrolidone, dimethylformamide, butyrolactone, aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons).
7. U.S. Pat. No. 4,904,571 teaches printed circuit board photoresist stripper composition containing (A) a solvent (e.g., water, alcohols, ethers, ketones, chlorinated hydrocarbons and aromatic hydrocarbons); (B) an alkaline compound dissolved in said solvent (e.g., primary amines, secondary amines, tertiary amines, cyclic amines, polyamines, quaternary ammonium amines, sulfoniumhydroxides, alkali hydroxides, alkali carbonates, alkali phosphates and alkali pyrophosphates); and (C) a borohydride compound dissolved in said solvent (e.g., sodium borohydride, lithium borohydride, dimethyl amine borone, trimethyl amine borone, pyridane borone, tert-butyl amine borone, triethyl amine borone, and morpholine borone).
8. U.S. Pat. No. 5,102,777 teaches a positive photoresist stripper composition comprising (A) a solvent (e.g., a pyrrolidone compound, a diethylene glycol monoalkyl ether, a sulfur oxide compound, a sulfolane compound or a mixture thereof); (B) an amine (e.g., alkanolamine); and (C) a fatty acid (e.g., capric acid, lauric acid, talmitric acid, caprylic acid, myristic acid, oleic acid, stearic acid, linoleic acid, linolic acid, buthylic acid, abietic acid, isooctoic acid, isohexadecanoic acid, isostearic acid, behenic acid, undecylenic acid, hydroxystearic acid, chipanodonic acid, arachidonic acid, oleostearic acid, and 2-ethylhexadecanilic acid).
9. U.S. Pat. No. 5,279,791 teaches a stripping composition for removing resists from substrates containing (A) hydroxylamine; (B) at least one alkanolamine; and optionally (C) at least one polar solvent.
10. U.S. Pat. No. 5,308,745 teaches an alkaline-containing photoresist stripping composition comprising (A) a stripping solvent (e.g., 2-pyrrolidinone, 1-methyl-2-pyrrolidinone, 1-ethyl-2-pyrrolidinone, 1-propyl-2-pyrrolidinone, 1-hydroxyethyl-2-pyrolidinone, 1-hydroxypropyl-2-pyrrolidinone, diethylene glycol monoalkyl ethers, dialkyl sulfones, dimethyl sulfoxide, tetrahydrothiophene-1,1-dioxides, polyethylene glycol, dimethylacetamide and dimethylformamide; (B) a nucleophilic amine (e.g., 1-amino-2-propanol, 2-(2-aminoethoxy) ethanol, 2-aminoethanol, 2-(2-aminoethylamino)-ethanol and 2-(2-aminoethylamino) ethylamine); and (C) a non-nitrogen containing weak acid (e.g., acetic acid, phthalic acid, 2-mercaptobenzoic acid, 2-mercaptoethanol, 1,3,5-trihydroxybenzene, pyrogallol, resorcinol, 4-tert-butylcatechol, carbonic acid and hydrofluoric acid).
11. U.S. Pat. No. 5,334,332 teaches a photoresist resist stripping and cleaning composition comprising (A) hydroxylamine; (B) at least one alkanolamine; (C) water; (D) optionally, at least one polar solvent; and (E) optionally, a chelating reagent (e.g., thiophenol, ethylenediamine tetraacetic acid and 1,2-dihydroxybenzene) to reduce the surface metal contamination on wafers.
12. U.S. Pat. No. 5,399,464 teaches a stripping composition for removing positive organic photoresist from a substrate comprising (A) a triamine (e.g., diethylene triamine); (B) a nonpolar or polar organic solvent (e.g., N-methyl pyrrolidone).
13. U.S. Pat. No. 5,417,802 teaches a material useful for photoresist removal or post-metal etch clean up that comprises (A) primary or secondary amines; (B) solvents (e.g., dimethyl sulphoxide or dimethylacetylamide); and (C) organic ligands such as crown ethers or cyclodextrines).
14. Japanese Published Patent Application No. 63-208043, which was published to R. Ohtani (Kanto Chemical) on Aug. 29, 1988, teaches a positive-working photoresist stripper composition containing (A) 1,3-dimethyl-2-imidazolidinone; (B) a water-soluble organic amine [e.g., monoethanolamine, 2-(2-aminoethoxy)-ethanol, triethylene(tetramine)]. The application also teaches a surfactant may be added to the stripper.
15. Japanese Published Patent Application No. 64-081949, which was published to K. Matsumoto (Asahi Chemical) on Mar. 28, 1989, teaches a positive-working photoresist stripper composition containing (A) a solvent (e.g., gamma-butyrolactone, N-methyl-formamide, N,N-dimethylformamide, N,N-dimethyl-acetamide or N-methylpyrrolidone); (B) an amino alcohol (e.g., N-butyl-ethanolamine and N-ethyldiethanolamine); and (C) water.
16. Japanese Published Patent Application No. 4-350660, which was published to H. Goto (Texas Instruments, Japan and Kanto Chemical, Inc.) on Dec. 4, 1992, teaches a stripper for positive photoresists comprising (A) 1,3-dimethyl-2-imidazolidinone (DMI), (B) dimethylsulfoxide (DMSO) and (C) a water-soluble amine [e.g., monoethanolamine or 2-(2-amino-ethoxy)ethanol] wherein the amount of the water-soluble amine is 7–30% by weight.
17. Japanese Published Patent Application No. 1999-197523 describes a stripper composition for photoresist used in manufacture of liquid crystal display device that includes 5–15 weight % of alkanolamine, 35–55% sulfoxide or sulfone compound, and 35–55 wt. % glycol ether.
18. Japanese Published Patent Application No. 08087118 describes a stripper composition that includes 50–90 weight % of alkanolamine, and 50–10% dimethyl sulfoxide or N-methyl-2-pyrrolidone.
19. Japanese Published Patent Application No. 03227009 describes a stripper composition that includes ethanolamine and dimethyl sulfoxide.
20. Japanese Patent 07069619 describes a stripper composition that includes alkanolamine, dimethyl sulfoxide, and water.
21. U.S. Pat. No. 5,480,585 and the Japanese Patent Hei. 5-181753 disclose organic strippers comprising alkanolamine, sulfone compound or sulfoxide compound and a hydroxyl compound.
22. The Japanese Laid-open Patent 4-124668 discloses a photoresist stripping composition including an organic amine of 20–90% by weight, phosphoric ester surfactant of 0.1–20% by weight, 2-butyne-1,4-diol of 0.1–20% by weight, and the remainder glycolmonoalkylether and/or aprotic polar solvent.
23. The Japanese Patent Laid-open Sho. 64-42653 discloses a photoresist stripping composition comprising over 50% by weight of dimethylsulfoxide (more desirably over 70% by weight), 1 to 50% by weight of a solvent selected among diethyleneglycolmonoalkylether, diethyleneglycoldialkylether, gamma-butyrolactone and 1,3-dimethyl-2-imidazoledione, and 0.1–5% by weight of nitrogen-including organic hydroxyl compound such as monoethanolamine. It states that the amount of dimethylsulfoxide less than 50% by weight causes great reduction in stripping force, while the amount of nitrogen-including organic hydroxyl compound solvent over 5% by weight corrodes the metal film such as aluminum.
Depending on the constituents of the compositions and the ratio thereof, the aforementioned stripping compositions exhibit greatly different characteristics in photoresist stripping force, metal corrosion properties, the complexities of a rinsing process following the stripping, environmental safety, workability and price. Several commercial products are now available to clean the photoresist and plasma etching residues left by plasma etching followed by oxygen ashing. For example, EKC 265™, available from EKC Technology, Inc., is a plasma etching cleaning solution composed of water, alkanolamine, catechol and hydroxylamine. Such a composition is disclosed in U.S. Pat. No. 5,279,771 to Lee.
Although these commercial products can dissolve photoresist and plasma-etching residues, the combination of water and alkanolamine contained therein can also attack the metallic layers deposited patternwise on the substrate. The addition of a corrosion inhibitor to these products can mitigate the unwanted attack on the metallic layers and oxide layers deposited on the substrate. However, even in the presence of a corrosion inhibitor, they may attack certain corrosion-sensitive metal layers such as copper, aluminum or aluminum alloys (e.g., Al—Cu—Si), titanium nitride, titanium tungsten and the like.
It is difficult to balance effective plasma etching residue removal and corrosion inhibition because chemical compositions of the plasma etching residues are generally similar to those of the metal layers or oxide layers on the substrate. The alkanolamine used in the prior art cleaning compositions was often times found to attack both the plasma etching residues and the substrate metal layers in the presence of water. Water is often added as a contaminant, for example from the atmosphere, from wet components, and the like, and may even be released from certain photoresist structures during dissolution. The problem of water-cleaning composition induced corrosion has resulted in manufacturers resorting to alcohol or other solvent, for example isopropyl alcohol, to remove the cleaner.
Moreover, if a post-cleaner rinse such as isopropyl alcohol was not used, the corrosion could be very severe. In addition, some types of the corrosion inhibitors have been found to retard plasma etching residue removal and other treatments. There is a need for strippers that are useful with corrosion-prone metal substrates, particularly for copper substrates, which do not corrode metal substrates in the presence of small quantities of water.
The stripping and cleaning compositions of the present invention remove photoresists without attacking the substrates themselves include metal substrates such as copper, aluminum, titanium/tungsten, aluminum/silicon, aluminum/silicon/copper; and substrates such as silicon oxide, silicon nitride, and gallium/arsenide, and plastic substrates such as polycarbonate. The requirement for a cleaning solution to remove all types of residue generated as a result of resist and etching of various types of metals, such as aluminum, aluminum/silicon/copper, titanium, titanium nitride, titanium/tungsten, tungsten, silicon oxide, polysilicon crystal, etc., presents a need for more effective cleaning chemistry in the processing area.
In addition to removing completely the resist material, particularly with the introduction of submicron process techniques to form wafers, there is a demand for cleaning technology for removing etching residue remaining following resist removal. Unfortunately, it has been found that no one cleaner is universal, in that it can clean the required materials without adversely affecting or hindering subsequent manufacturing operation or process steps involving the substrate. The requirement for a cleaning solution to remove photoresist and other residue of various types of metals, such as aluminum, aluminum/silicon/copper, titanium, titanium nitride, titanium/tungsten, tungsten, silicon oxide, polysilicon crystal, low-k materials, etc., presents a need for more effective cleaning chemistry in the processing area.

Process for the use of bis-choline and tris-choline in the cleaning of quartz-coated polysilicon and other materials


An assembly (M) of a detection unit (100) for placement inside a tire with a rim having a connection aperture (210) is provided. The assembly (M) can include a detection unit (100) for receiving detection components, a valve body (300), a seal (400) for providing a seal between the valve body (300) and the rim (200), and fastener (500) for holding the valve body (300) in position on the rim (200). One or more of the detection unit (100), the valve body (300), the fastener (500) for holding the valve body (300), or a combination thereof, is preformed to penetrate the connection aperture (210) so as to engage the connection aperture (210) when the assembly (M) is subjected to tangential stresses.

1. Field of the Invention
This invention relates to the field of detecting parameters such as the pressure or temperature inside a tyre, and more specifically to variations enabling the detection unit to be attached to the wheel rim under optimal conditions.
2. Related Art of the Invention
There are several solutions in the prior art for attaching a detection unit. These solutions include the one adopted by the invention, which involves attaching, inside the rim, the detection unit which contains sensors corresponding to the parameters to be monitored, to the tyre inflation valve body.
The applicant has noted that the implementations of this attachment solution known in the prior art have certain disadvantages, as described below.
American documents U.S. Pat. No. 6,055,855 and 5,844,131 propose attaching a detection unit inside a tyre by means of a valve body, which involves an attachment assembly in which said body is preformed at a first end to pivotably receive the unit and at its second end to enable a fixing nut to be screwed. The valve body is also preformed on its internal portion, with a shoulder on which an elastomer seal is arranged so that the screwing action of the nut coming into contact with the external surface of the rim enables the shoulder to move toward the internal surface of the rim, thus fixing the elastomer seal against said surface. The elastomer seal is preformed to penetrate the aperture made in the rim to enable the attachment of the valve and to be inserted in this aperture between the valve body and the rim. The screwing action also ensures that said unit is urged against the internal surface of the valve.
This embodiment has several disadvantages noted by the applicant, including the following:                When the wheel rotates at high speed, the valve body is subjected to very high stresses which are transferred to the seal placed between the body and the rim. However, the lifetime of an elastomer sealing element which is not designed to withstand such stress is considerably reduced, leading to pressure loss and failure.        The seal is urged against the internal surface of the rim, which in most cases has a surface planarity capable of damaging the seal and/or reducing its sealing ability.        As the seal is an integral part of the attachment assembly, the screwing force must be adjusted and not exceed a threshold beyond which the seal would be damaged. However, this controlled screwing is not always respected.        Moreover, insofar as the screwing force is performed as prescribed, the presence of the fixing nut at the exterior makes unintentional unscrewing very easy.        As it is simultaneously subjected to the screwing pressure, tangential forces due to the rotation of the wheel, and the pressure and temperature of the tyre, the seal is subjected to a phenomenon of creep, in which its internal portion is dilated and the part inserted between the cylindrical surface of the valve and the cylindrical surface of the aperture made in the rim for receiving said valve is compressed.        By urging the unit against the rim, the latter is subjected to the temperature of the rim.        Such an assembly is suitable for an attachment to an automobile wheel rim in which the valve is not present in the plane of symmetry of the rim.
A modification is described in the French document FR2834245 which, on the basis of the same attachment principle, has the advantage of proposing a valve body with an internal shoulder against which the elastomer seal is positioned, with the latter being preformed so as to form a mechanical stop opposing the screwing force of the external nut so that the screwing force exerted on the seal does not exceed the threshold value, beyond which it will be damaged. Although this assembly proposes a solution to one of the problems of the prior art, it retains the other disadvantages described above.
In addition, another disadvantage found in the prior art relates to the unit itself which, for reasons of sealing and holding the components that it receives in position, is conventionally filled with a plastic material that increases the weight of the unit and makes it impossible to recycle it. The speeds and accelerations to which the unit is subjected make any additional mass become an additional stress transferred to the assembly for attaching the unit to the valve and consequently to the seal in the solutions of the prior art.

Assembly for attaching a detection unit, in particular for detecting tyre pressure, to a rim


Imidazolium salts are the immediate precursors to N-heterocyclic carbenes (NHC) yet a simple, general synthetic route to a wide variety of imidazolium salts is not yet available. Such a straightforward route is described for two specific members of this family of ligand precursor: 1,3-Bis(2,4,6-trimethylphenyl)imidazolium chloride (IMes.HCl) and 1,3-Bis(2,6-diispropylphenyl)imidazolium chloride (IPr.HCl). The procedure appears general and similar protocols can be used to isolate various imidazolium salts.

1. Field of the Invention
The present invention relates to imidazolium salts. More particularly, the present invention relates to methods of producing imidazolium salts.
2. General Background of the Invention
N-heterocyclic carbenes1, so called "phosphine-mimics", have attracted considerable attention as possible alternatives for the widely used phosphine2 ligands in homogeneous catalysis.34
The primary advantage of these ligands appears to be that they do not easily dissociate from the metal center, and as a result an excess of the ligand is not required in order to prevent aggregation of the catalyst usually affording the bulk metal5. The use of these ligands in palladium-catalyzed Heck6, Suzuki-Miyaura7, Stille8, Sonogashira9, aryl amination10, telomerization of butadiene11, Hiyama12, Kumada-Corriu reactions13 14 15, rhodium-assisted hydrosilylation16, iridium-mediated olefin hydrogenation17 and ruthenium-mediated olefin metathesis7,8 has opened new opportunities in catalysis. The synthesis of the NHC generally involves the deprotonation of the imidazolium precursor by action of a base.
The synthesis of the imidazolium salts as reported by Arduengo18 involves a condensation reaction with concomitant azeotropic removal of water at elevated temperatures.
This protocol is not general for aryl bearing imidazolium and sterically congested imidazolium salts (bulky groups on nitrogen) often fails or leads to low yields of product.
The previously reported synthetic procedures for the preparation of imidazolium salts necessitated high temperature, dry solvents and handling under inert atmosphere.18 An alternative method employed molecular sieves to absorb the water generated in the condensation reaction. It also required heating for long reaction times.2 It should also be noted that these reaction times would have to be significantly longer if these protocols were performed on very large scale. As a result of prolonged heating, decomposition occurs and tars are generated which render product isolation difficult and isolated yield lower than optimum. As some imidazolium salts are not at all amenable to assembly using the "one-pot" protocol, we have explored the possibility of performing the condensation reactions in a two-step procedure.
The following U.S. patents are incorporated herein by reference: U.S. Pat. Nos. 5,077,414; 5,182,405; and 6,316,380

Synthesis of 1,3 distributed imidazolium salts

University of New Orleans Research and Technology Foundation, Inc.


Apparatus, systems, and methods may operate to invoke multiple authentication mechanisms, by a client node, to encrypt N split-keys using credentials associated with corresponding ones of the authentication mechanisms. Further activity may include transforming the split-keys to provide N encrypted split-keys, and storing each of the encrypted split-keys with an associated local user identity and an identity of corresponding ones of the authentication mechanisms. Additional apparatus, systems, and methods are disclosed.

Today, many computers (e.g., workstations, personal computers, notebook computers, thin clients, tablet computers, etc.) contain sensitive information which users desire to protect. In this regard, an advanced authentication server is sometimes used to provide multi-factor authentication over a network connection to such computers, when they operate as clients. Sometimes however, the server is not available to these clients at the time that authentication is desired.

This patent is subject to a terminal disclaimer.


A drive screw comprises: a head portion; a shank; and a helical thread portion extending along almost all the length of the shank, wherein an outside diameter of the drive screw including the thread portion being formed so as to be reduced from a portion close to the head portion in at least three stages.

The invention relates to a drive screw that fastens a member to be driven so as to be first driven onto and then screwed into such member to be driven.
Generally, drive screws are often used to fasten a gypsum board to a sheet steel. A drive screw includes a large diameter portion and a small diameter portion. First, when the drive screw has been driven, the small-diameter portion goes through a sheet steel to thereby allow the large-diameter portion to stay within a gypsum board, and then the large-diameter portion is screwed into the sheet steel in the screwing phase to thereby fasten the sheet steel and the gypsum board together.
There are cases where not only a single gypsum board but also two or more gypsum boards are fastened to a sheet steel. Further, gypsum boards to be used come in large and small thicknesses. It goes without saying that a drive screw for fastening two gypsum boards or a thick gypsum board is longer than a drive screw for fastening a single gypsum board or a thin gypsum board.
By the way, there are cases where fastening involves only a single gypsum board or two gypsum boards and fastening involves a combination of a thin gypsum board and a thick gypsum board at a single construction site. In such cases, the cumbersome operation of selecting a drive screw so that the lengths of the drive screws match the thicknesses of the gypsum boards impairs operation efficiency. Therefore, a drive screw that can overcome such inconvenience has been called for.
However, the shank of a conventional drive screw for a single gypsum board is too short to fasten two gypsum boards, so that defective fastening results. On the other hand, if a drive screw for two gypsum boards is used to fasten a single gypsum board, the large-diameter portion of such drive screw passes through as far as to a sheet steel, which thus imposes the problem that a predetermined fastening force cannot be provided. Therefore, in the case of the conventional drive screw, one must change the type of drive screw depending on the thickness and number of gypsum boards.
Similar problems have been addressed not only in the case of fastening a gypsum board to a sheet steel, but also in the case of fastening a plate member such as a sheet of plywood to a piece of timber.
Furthermore, the present applicant has proposed a drillig screw adapted for screwing operation to fix a gypsum board to a light gauge channel steel whose thickness is either 0.5 mm or 0.8 mm used as structural materials for the construction of houses (Japanese Patent Application No. Hei. 7-213780). The purpose of this drilling screw is to improve screwing efficiency by allowing gypsum board screwing operation to be performed using a drive type screwing machine whose operation time is faster than an electrically-driven screwing machine involving only rotating operation.
That is, when a gypsum board is screwed using a conventional drilling screw and a drive type screwing machine, addressed are inconvenience that the preceding drilling screw that has been fastened is slacken due to impact accompanied by the driving operation of the succeeding drilling screw, that the load stress of the drilling screw is reduced to a significant degree while embedded into the gypsum board, or the like. Therefore, the conventional drilling screw has not allowed the gypsum board screwing operation to be performed using the drive type screwing machine.
A drilling screw proposed by the present applicant has overcome the aforementioned problem. That is, the drilling screw is characterized as allowing the diameter thereof to be tapered from a large-diameter parallel thread portion having a trumpet head to a small-diameter parallel thread portion via a tapered thread portion and as giving a tapered bit portion at the point of the small-diameter parallel thread portion.
When the drilling screw is driven into a gypsum board that is overlapped on a light gauge channel steel using the driver of a drive type screwing machine, the tapered bit portion and the small-diameter parallel thread portion pass through the gypsum board and the light gauge channel steel. Then, the driver starts turning the drilling screw, causing the intricately designed thread ridges of the small-diameter parallel portion to develop a thrust in a direction in which the drilling screw passes through the light gauge channel steel, so that the tapered thread portion taps the through hole in the light gauge channel steel so as to enlarge such through hole. As a result, the parallel thread portion goes through the light gauge channel steel to thereby strongly fasten the drilling screw.
As a result of the small-diameter parallel thread portion and the tapered bit portion, the aforementioned drilling screw is advantageous in the following point compared with the conventional drilling screw having such a simple shape in which a parallel thread portion and a front end tapered thread portion are formed continuously to each other. That is, the aforementioned drilling screw can reduce the deformation and vibration of the steel sheet attributable to impact accompanied by the driving of the drilling screw into a light gauge channel steel, which in turn eliminates reduction in fastening force and load stress. As a result, the screwing operation using a drive type screwing machine which has not been able to be performed with the prior drilling screws can be implemented.
However, at the time of screwing the drilling screw into a side plate portion of the light gauge channel steel, the side plate portion that is weaker in shape holding strength than the bottom portion may, in some cases, be deformed due to impact applied by the drilling screw, or the gypsum board may, in some cases, float from the channel steel. In such cases, the drilling screw is not driven deep enough into the channel steel so that the small-diameter parallel thread portion may not, in some cases, go through the steel plate. As a result, the drilling screw does not develop thrust during the turning operation, so that the drilling screw idly turns while not being screwed in.
Therefore, addressed in the aforementioned cases also are technical problems to be overcome to fasten a gypsum board and a channel steel reliably.


A rescue ramp (10) for use by a watercraft (11) includes a laterally extending first inflatable tube member (14) attachable to the watercraft (11). Second spaced inflatable tube members (15) are connected at one end to and extend longitudinally from the ends of the first tube member (14). A third inflatable tube member (16) is connected between the second tube members (15) near the other end thereof and is adapted to be positioned in the water. A ramp (17) is connected to the first and second tube members (14, 15) so that when the rescue ramp (10) is inflated and attached to the watercraft (11), a person may traverse from the water to the watercraft (11) or from the watercraft (11) to the water. The first tube member (14) is attached to the watercraft (11) by means of a girt bar (23) releasably mounted on the watercraft (11). The girt bar (23) is connected to a first flap (26) which is detachably connected to a second flap (20) attached to the first tube member (14).

The rescuing of people stranded in a body of water, particularly turbulent waters encountered in the oceans of the world, is not a simple task. In many environments, such as at off-shore drilling rigs, motorized boats are held by davits to be deployed in the event of an emergency, such as an explosion at the site, which might cause many people to be stranded in the water. Upon such a disaster, it is usually not difficult for the rescue craft to arrive at the location of the stranded person or persons, but rather the problem is boarding the person into the craft. Such a procedure is compounded not only if the person is unconscious or injured, but also if turbulent water is prevalent.
Present known devices of rescuing a person from the sea are not satisfactory for all encountered circumstances. One of the simplest known devices is a rope-like ladder which is attached to the boat at its hatch or portal and merely thrown in the water so that the person to be rescued might climb into the boat. While such may be satisfactory in calm seas, in turbulent situations it is not only difficult to climb the undulating ladder, but also it is highly likely that the person could be injured, as by striking his head on the gunnel or ledge below the hatch. Moreover, the ladder is totally useless if the person to be rescued is injured or unconscious. In such situations, the rescue boat must be manned with several people, some of whom must traverse down the ladder to assist the person to and up the ladder, while others in the craft assist to pull the person on board, while all the time trying to avoid contact with the undulating gunnel.
Another prior art device which has been utilized is a net-like structure which is thrown toward the person to be rescued. If conscious, he may then either hold onto or lay on the net while being pulled into the craft. Such a device suffers from the same problems as does the aforementioned ladder and is simply not a convenient and safe manner in which to rescue the panicked person.
A variety of the net-like structure just described involves a slat-like runner which is thrown into the water. In the operation of this device, the person is positioned on the structure and essentially rolled up into the craft. However, it is almost mandatory that a person from the craft be in the water to utilize this system of rescue, and in addition, at least two people in the craft must be employed to pull the person into the craft.
Thus, the need exists for a system which will allow the conscious person to easily enter the rescue craft on his own power, and a system which accommodates the facile assistance of an unconscious or injured person into the craft.


A sphere mount for a ball mounted retro-reflector having a perimeter recess and a base shank. The sphere mount is configured to receive a ball mounted retro-reflector in a centrally disposed conical nest, such as a three-point conical nest, and to position it with a high degree of precision over the central axis of the base shank to within ±0.0005 of an inch. The perimeter recess is in the form of a single oblique scallop, orientated from the upper surface to the lower surface, and permits a maximum negative acceptance angle for incident light to a mounted spherical retro-reflector with no occlusion by the sphere mount perimeter.

The present invention relates to mounts for precision optical elements, and in particular, to a spherical retro-reflector three-point conical nest sphere mount, having a negative acceptance angle.
Modern manufacturing technology, particularly that associated with the construction of large composite material structures, requires the contours of components and tooling to be accurately measured and inspected for compliance with design models and specifications. One manner in which these structures are measured is with the aid of portable coordinate measuring machines such as laser trackers.
Laser trackers measure and inspect large components by illuminating one or more retro-reflecting targets mounted to the components in predetermined locations with a laser. The distance between the laser tracker and the retro-reflector target is measured using the laser, and compared with design models or specifications, such as those stored on a computer.
To facilitate the use of laser trackers, retro-reflectors are centrally mounted in hollow steel balls, commonly referred to as Spherically Mounted Retro-reflectors (SMR), which in turn are fitted to the target object in predetermined locations with the use of sphere mounts, such as is shown at in FIG. 1. The hollow steel balls include a circular opening or aperture in an exterior surface, through which laser light enters the ball and is reflected back along an incident angle to the source by the internally mounted retro-reflector. Surrounding the circular opening or aperture is a cylindrical hood, configured to reduce or eliminate unwanted glare and to protect the glass optical retro-reflector from breakage. Each sphere mount is typically cylindrical or disc shaped, and include a recessed conical nest in one surface which holds and locates the retro-reflector ball, usually with the aid of a magnet. The opposite surface of the sphere mount is either flat to within a predetermined tolerance or includes a base shank, configured for seating within a correspondingly sized bore on the target object, permitting the sphere mount to be located at a known position on the target object. For high tolerance applications, a sphere mount having a three-point conical nest, commonly referred to as a kinematic mount, may be utilized.
Conventional sphere mounts such as those shown in FIG. 1 come in a variety of standard sizes, such as 0.500″, 0.875″, and 1.500″ and have a hemispherical range of illumination acceptance, which is generally limited by the mechanical interaction between the edge of the circular opening or aperture in the retro-reflector ball and the upper surface of the sphere mount. FIG. 4 illustrates how the retro-reflector ball in a conventional sphere mount may rotate through a vertical arc of 180° and may rotate 360° about the central axis within the conical nest of the sphere mount.
In some applications, the laser tracker or illumination source may not be disposed within the hemispherical range of illumination acceptance defined by the upper surface of the sphere mount, but rather, slightly below the lower boundary. For these applications, it is known to employ sphere mounts having an axially perpendicular recess between the base of the conical nest and the circumferential perimeter, such as is shown in FIG. 5. Illustrated in phantom in FIG. 5, a retro-reflector ball placed in such a modified sphere mount may rotate through a vertical arc angle greater than 180° when radially aligned with the perpendicular recess, by seating the cylindrical hood within the recess, providing an extending illumination acceptance range.
Vertical arc angles of illumination acceptance from 0° to 180° are considered "positive" angles while vertical arc angles of acceptance greater than 180° (i.e. below the horizon of the sphere base, are considered "negative" angles. However, as can be seen in FIG. 5, a portion of the circular opening or aperture to the ball mounted retro-reflector is occluded by the modified sphere mount, reducing the effective size of the circular opening or aperture and rendering measurement readings more difficult to obtain.
Accordingly, there is a need in the portable precision measurement industry for a modified sphere mount design which will provide a maximum illumination acceptance range for a ball mounted retro-reflector greater than 180°, and which will not occlude the retro-reflective elements and illumination source.

Spherical retro-reflector mount negative


Provide herein is a deer rub or lure and a method of luring a deer to a selected area. The deer rub or lure has a trunk or signpost with at least one aperture extending therein. A flexible rod extends into at least one of the apertures. Each of the flexible rods extends from the trunk or signpost at an angle between 90° and 180°. A licking branch is attached to the flexible rod. A flexible support extends from a lower end of the trunk or signpost, and the support is configured to flexibly support the trunk or signpost in a substantially vertical orientation.

The background information is believed, at the time of the filing of this patent application, to adequately provide background information for this patent application. However, the background information may not be completely applicable to the claims as originally filed in this patent application, as amended during prosecution of this patent application, and as ultimately allowed in any patent issuing from this patent application. Therefore, any statements made relating to the background information are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.
Deer are one of the most popular game animals for hunting. Various techniques have been used to attract deer, especially bucks, to hunting locations. These techniques often involve the use of food or scents to attract deer. Deer can be very territorial, particularly bucks during the mating season, and will often frequent the same locations. As a result, hunters often look for signs of deer activity, which can include deer beds, trails, scrapes, and rubs.
A rub is often made on trees or brush when a buck rubs his antlers or forehead against it, often wearing off exterior portions of the plant or bark. Buck rubs sometimes appear in early to mid-September, in much of the US. That's typically when bucks lose their antler velvet, a soft, blood-rich tissue that covers growing antlers from early spring through summer, in most of the US. Once antlers are fully developed, their velvet starts drying and shedding. Bucks accelerate its removal by rubbing their antlers on trees or raking them through brush or on trees, sometimes making a rub visible on a tree.
For much of the country, the mating season or rut occurs from late October to early December. Before and during the rut, bucks rub trees to mark their territory, work off aggression, and intimidate other bucks. A series of rubs may be made along a trail or field edge are called rub lines, and provide clues about a deer's travel patterns.
Buck rubs may serve as a signpost or display dominance symbols and communication signposts. They notify other deer of the deer's presence and possibly its breeding intentions. When a buck rubs trees, brush and saplings, it leaves behind scents from its forehead and may rub the bark from a tree or leave other visible signs. For example, a buck may transfer a scent such as wax from its pre-orbital gland, located in its eyes. Other deer may sniff rubs, and sometimes rub the spot themselves before moving on. Bucks rub tree trunks, tree limbs, and brush of a variety of sizes, such as saplings and large trees. While rubbing, bucks may leave a waxy secretion form their pre-orbital gland which may notify other deer of his presence.
It may be desired to have a deer rub or lure that may be placed at a desired location.