Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal, and applications thereof are described herein. Reducing or eliminating DC offset voltages and re-radiation generated when down-converting an electromagnetic (EM) signal is also described herein. Down-converting a signal and improving receiver dynamic range is also described herein.

1. Field of the Invention
The present invention relates to down-conversion and up-conversion of electromagnetic (EM) signals. More particularly, the present invention relates to reducing or eliminating DC offset voltages and re-radiation that occurs during down-conversion of EM signals to intermediate frequency or baseband signals.
2. Related Art
Electromagnetic (EM) information signals (baseband signals) include, but are not limited to, video baseband signals, voice baseband signals, computer baseband signals, etc. Baseband signals include analog baseband signals and digital baseband signals.
It is often beneficial to propagate EM signals at higher frequencies. This is generally true regardless of whether the propagation medium is wire, optic fiber, space, air, liquid, etc. To enhance efficiency and practicality, such as improved ability to radiate and added ability for multiple channels of baseband signals, up-conversion to a higher frequency is utilized. Conventional up-conversion processes modulate higher frequency carrier signals with baseband signals. Modulation refers to a variety of techniques for impressing information from the baseband signals onto the higher frequency carrier signals. The resultant signals are referred to herein as modulated carrier signals. For example, the amplitude of an AM carrier signal varies in relation to changes in the baseband signal, the frequency of an FM carrier signal varies in relation to changes in the baseband signal, and the phase of a PM carrier signal varies in relation to changes in the baseband signal.
In order to process the information that was in the baseband signal, the information must be extracted, or demodulated, from the modulated carrier signal. However, because conventional signal processing technology is limited in operational speed, conventional signal processing technology cannot easily demodulate a baseband signal from higher frequency modulated carrier signal directly. Instead, higher frequency modulated carrier signals must be down-converted to an intermediate frequency (IF), from where a conventional demodulator can demodulate the baseband signal.
Conventional down-converters include electrical components whose properties are frequency dependent. As a result, conventional down-converters are designed around specific frequencies or frequency ranges and do not work well outside their designed frequency range.
Conventional down-converters generate unwanted image signals and thus must include filters for filtering the unwanted image signals. However, such filters reduce the power level of the modulated carrier signals. As a result, conventional down-converters include power amplifiers, which require external energy sources.
When a received modulated carrier signal is relatively weak, as in, for example, a radio receiver, conventional down-converters include additional power amplifiers, which require additional external energy.

Method and apparatus for reducing re-radiation using techniques of universal frequency translation technology


A variable-length code decoder sequentially decodes a series of variable-length codewords included in a bit stream and outputs decoded symbols corresponding to the codewords. The decoder includes an interface section and a decoding section. The interface section accumulates various code lengths of the decoded codewords to obtain a sum. Next, the interface section selects an N-bit contiguous data sequence (where N is a maximum code length of the codewords) from a 2N- or (2Nxe2x88x921)-bit contiguous data sequence, included in the bit stream, in accordance with the sum and outputs the N-bit contiguous data sequence. The decoding section receives the output of the interface section and decodes a codeword included in a combination of the output and a previous output of the interface section by reference to a lookup table, thereby obtaining and outputting a decoded symbol and outputting a code length of the decoded codeword to the interface section.

The present invention relates to a variable-length code (VLC) decoder.
In order to reduce the bandwidth of a communication means or the capacity of a storage medium in transmitting or recording a moving picture, the picture is compressed and encoded. International standards for moving picture encoding include H.261, MPEG (moving picture experts group) 1, MPEG2, and so on.
These encoding methods are combinations of motion vector estimation and motion compensation, DCT (discrete cosine transform), quantization, zigzag scanning, variable-length coding, etc. Variable-length coding is an encoding method for reducing the average number of bits by converting quantized fixed-length codewords into a bit stream of variable-length codewords according to their statistics. To decode such a bit stream and present moving pictures, it is necessary to perform variable-length code (VLC) decoding for converting the variable-length codewords into the original fixed-length data. In VLC decoding, the codewords have non-constant lengths, and it is not possible to identify the first bit position of each variable-length codeword in the bit stream. Therefore, the codewords need to be decoded according to the order of bits included in the bit stream.
Various VLC decoders have been proposed in the art to realize a high-speed VLC decoding operation. A known VLC decoder is disclosed in U.S. Pat. No. 5,245,338. FIG. 11 is a block diagram illustrating a VLC decoder of this type. The VLC decoder shown in FIG. 11 decodes variable-length codewords with a maximum code length of 16 bits.
A buffer 901 stores an input bit stream. If a read signal RD is xe2x80x9c1xe2x80x9d, the buffer 901 outputs the stored bit stream to a first barrel shifter 911 and a first input register 912 on a 16-bit basis in the next cycle. The buffer 901 holds the output for one cycle.
The first and second input registers 912 and 913 have a 16-bit configuration, and latch the input data in the next cycle if an update signal is xe2x80x9c1xe2x80x9d.
The first barrel shifter 911 combines the outputs of the second and first input registers 913 and 912 and the output of the buffer 901 with each other as the upper, middle and lower 16-bit sub-sequences, respectively, to obtain a 48-bit data sequence. Then, using a sum SM (from 0 through 31), i.e., the output of an adder 914, as a shift length (from 1 through 32), the first barrel shifter 911 selects 16 bits from the 48-bit combined data sequence and then writes the 16-bit data sequence on a first barrel shifter register 922. The 16 bits selected are the (shift length+1)th through (shift length+16 bits of the 48-bit data sequence as counted from the most significant bit (MSB) thereof. It should be noted that the xe2x80x9cfirst bitxe2x80x9d herein means the MSB of the 48-bit combined data sequence.
A second barrel shifter 921 combines the outputs of second and first barrel shifter registers 923 and 922 with each other as the upper and lower 16-bit sub-sequences, respectively, to obtain a 32-bit data sequence. Then, using the output of a shift length register 925 as a shift length (from 1 through 16), the second barrel shifter 921 selects 16 bits from the 32-bit combined data sequence and then writes the 16-bit data sequence on the second barrel shifter register 923. The 16 bits selected are the (shift length+1)th through (shift length+16)th bits of the 32-bit data sequence as counted from the MSB thereof.
A lookup table (LUT) 924 performs variable-length code decoding on the output of the second barrel shifter 921 to obtain a decoded symbol DC and a code length CL (from 1 through 16), and then writes the code length CL on the shift length register 925. The LUT 924 is a table so compiled as to output a decoded symbol and a code length for each codeword with any of various lengths. The LUT 924 receives each codeword with the first bit thereof regarded as the MSB thereof.
The adder 914 adds together the output of the shift length register 925 (from 1 through 16) and the output of an accumulation register 915 (from 0 through 15) to output the sum SM. The adder 914 writes a carry signal CR, which is xe2x80x9c1xe2x80x9d if the sum SM is 16 to 31, on a hold register 916 and writes a remainder RM (from 0 through 15) of the sum SM modulo 16 on the accumulation register 915. Thus, the MSB of the 5-bit sum SM, obtained by adding together the 5-bit output of the shift length register 925 and the 4-bit output of the accumulation register 915, is the carry signal CR, while the remaining 4 bits thereof is the remainder RM of the sum SM modulo 16. The carry signal CR is used as an update signal for the first and second input registers 912 and 913, and the read signal RD, i.e., the output of the hold register 916, is used as a read signal for the buffer 901.
FIG. 12 illustrates exemplary cycle-by-cycle data flows in the VLC decoder shown in FIG. 11. For example, xe2x80x9ca1-a8xe2x80x9d denotes an 8-bit data sequence consisting of a1, a2, a3, a4, a5, a6, a7 and a8. For example, xe2x80x9ca1-a8b1-b6c1-c2xe2x80x9d for the buffer output in cycle 0 denotes a 16-bit data sequence consisting of a1 through a8, b1 through b6 and c1 through c2.
In FIG. 12, as for cycle 0 to cycle 2, the update and read signals and shift lengths for the first and second barrel shifters are xe2x80x9c1xe2x80x9d, xe2x80x9c1xe2x80x9d, xe2x80x9c16xe2x80x9d and xe2x80x9c16xe2x80x9d, respectively, to set initial-state data for the respective registers. From cycle 3 on, the same processing is repeatedly performed based on the respective values of the carry and read signals, the accumulation register and the shift length register.
In this manner, a decoded symbol is obtained every cycle. At the beginning of the decoding operation, the first decoded output is obtained in cycle 2, i.e., two cycles later than cycle 0 at which the input buffer 901 outputs data for the first time.
However, the known VLC decoder as illustrated in FIG. 11 needs two input registers and a 48-bit-input, 16-bit-output circuit as the first barrel shifter. Thus, the decoder must be implemented at a large circuit size, and occupies an excessively broad chip area when realized as an LSI.
In addition, when the conventional VLC decoder illustrated in FIG. 11 starts its decoding operation, it is not until two cycles have passed after the input buffer has supplied its first output that a first decoded codeword is obtained. If multiple streams of variable-length codewords are included in a single bit stream, information other than the variable-length code, such as headers, is included between the variable-length codeword streams. In such a case, the variable-length codeword streams are not contiguous with each other, and the VLC decoding cannot be performed continuously. Thus, if the VLC decoding cannot be performed consecutively, the 2-cycle delay occurs every time a variable-length codeword stream starts to be decoded. As a result, it takes a huge number of cycles to decode the entire bit stream.
It is therefore an object of the present invention to implement a variable-length code decoder at a reduced circuit size so that the decoder occupies a smaller chip area and supplies its decoded output at a much smaller delay.
Specifically, an inventive variable-length code decoder sequentially decodes a series of variable-length codewords included in a bit stream and outputs decoded symbols corresponding to the codewords. The decoder includes an interface section and a decoding section. The interface section accumutates various code lengths of the decoded codewords to obtain a sum. In accordance with the sum, the interface section selects a contiguous data sequence having a length of N bits (where N is a maximum code length of the variable-length codewords) from another contiguous data sequence, which has a length of 2N or 2Nxe2x88x921 bits and included in the bit stream, and outputs the N-bit contiguous data sequence. The decoding section receives the output of the interface section and decodes a codeword, included in a combination of the output and a previous output of the interface section, by reference to a lookup table, thereby obtaining and outputting a decoded symbol and also outputting a code length of the decoded codeword to the interface section.
According to this invention, the decoder is implementable in a smaller circuit size, because the interface section selects an N-bit contiguous data sequence, needed for the decoding section, from a 2N- or (2Nxe2x88x921)-bit contiguous data sequence included in the bit stream.
In one embodiment of the present invention, the interface section may include accumulation register, adder, input register and barrel shifter. The accumulation register stores and outputs a remainder derived from the sum. The adder adds together the code length and the remainder, which have been output from the decoding section and the accumulation register, respectively, to obtain the sum. Then, the adder outputs a quotient and a remainder, which are obtained by dividing the sum by N, as a carry signal and a new remainder, respectively. The input register stores and outputs a contiguous data sequence, which has a length of N or Nxe2x88x921 bits and is included in the bit stream, if the carry signal is one. The barrel shifter combines the output of the input register with the following N-bit contiguous data sequence, which is included in the bit stream, so that the bits are arranged in the same order as in the bit stream. Next, the barrel shifter selects an N-bit contiguous data sequence from the combined data sequence using the remainder, output from the accumulation register, as a shift input value, and then outputs the N-bit contiguous data sequence selected to the decoding section. The N-bit contiguous data sequence selected starts from a bit position that has been determined in accordance with the shift input value.
According to this embodiment, the carry signal is used for updating the data stored on the input register, and the remainder of the sum is written on the accumulation register. Accordingly, the remainder will be used as a shift length for the barrel shifter one cycle later. Thus, even if the sum of code lengths exceeds the maximum code length so that a shift operation should be performed at a shift length exceeding the maximum code length, the barrel shifter may perform a shift operation at a small shift length. This is because by updating the input register, after the barrel shifter has performed a first shift operation at the shift length equal to the maximum code length, the shifter may perform another shift operation at the remaining shift length in the next cycle. Therefore, the bit width of the barrel shifter can be reduced. Moreover, since only one input register is required, only one cycle is needed for initialization.
In this particular embodiment, the barrel shifter preferably selects and outputs the N-bit contiguous data sequence, which starts from an (M+2)th bit (where M is the shift input value) of the combined data sequence as counted from the first bit thereof.
According to this embodiment, the interface section can select and output the N-bit contiguous data sequence, needed for the decoding section, in accordance with the shift input value.
In another embodiment of the present invention, the decoding section may includes barrel shifter, barrel shifter register and lookup table. The barrel shifter combines outputs of the barrel shifter register and the interface section so that the bits are arranged in the same order as in the bit stream. Next, the barrel shifter selects an N-bit contiguous data sequence from the combined output using the code length, output from the lookup table, as a shift input value, and then outputs the N-bit contiguous data sequence selected. The N-bit contiguous data sequence selected starts from a bit position that has been determined in accordance with the shift input value. The barrel shifter register stores and outputs the output of the barrel shifter. And the lookup table outputs the symbol, corresponding to the codeword included in the output of the barrel shifter register, and outputs the code length of the decoded codeword.
According to such an embodiment, the output of the interface section is directly input to the barrel shifter of the decoding section, and the output of the barrel shifter is written on the barrel shifter register. Accordingly, the decoder may have a reduced number of barrel shifter registers.
In this particular embodiment, the barrel shifter preferably selects and outputs the N-bit contiguous data sequence, which starts from an (L+1)th bit (where L is the shift input value) of the combined output as counted from the first bit thereof.
According to this embodiment, an N-bit contiguous data sequence, beginning with a codeword to be decoded next, can be input to the lookup table.
In still another embodiment, the decoding section may further include a code length converter for outputting a value obtained by subtracting one from the code length. The barrel shifter may select and output the N-bit contiguous data sequence, which starts from an (L+2)th bit of the combined output as counted from the first bit thereof, by using not the code length but the output of the code length converter as the shift input value.
According to this embodiment, the range of shift input values for the barrel shifter can be narrowed. Particularly, if the maximum code length is an nth power of two, the number of bits representing the shift input value decreases. Thus, the shift input for the barrel shifter can have a smaller bit width.
In yet another embodiment, the decoding section may include barrel shifter, first and second barrel shifter registers, lookup table and shift length register. The barrel shifter combines outputs of the first and second barrel shifter registers with each other so that the bits are arranged in the same order as in the bit stream. Next, the barrel shifter selects an N-bit contiguous data sequence from the combined output using a value, derived from an output of the shift length register, as a shift input value, and then outputs the N-bit contiguous data sequence selected. The N-bit contiguous data sequence selected starts from a bit position that has been determined in accordance with the shift input value. The first barrel shifter register stores and outputs the output of the interface section. The second barrel shifter register stores and outputs the output of the barrel shifter. The lookup table outputs the decoded symbol, corresponding to the codeword included in the output of the barrel shifter, and outputs the code length of the decoded codeword. And the shift length register stores and outputs a value corresponding to the code length.
According to this embodiment, an N-bit contiguous data sequence, including a variable-length codeword to be decoded, can be selected from the output of the interface section, and then decoded sequentially.
In this particular embodiment, the shift length register preferably stores and outputs the code length. The barrel shifter preferably selects and outputs the N-bit contiguous data sequence, which starts from an (L+1)th bit of the combined output as counted from the first bit thereof, by using the output of the shift length register as the shift input value.
According to this embodiment, an N-bit contiguous data sequence, beginning with a codeword to be decoded next, can be input to the lookup table.
In an alternative embodiment, the decoding section may further include a code length converter for outputting a value obtained by subtracting one from the code length. The barrel shifter may select and output the N-bit contiguous data sequence, which starts from an (L+2)th bit of the combined output as counted from the first bit thereof, by using the code-length-minus-one value, which has been input thereto by way of the code length converter and the shift length register, as the shift input value.
According to this embodiment, the range of shift input values for the barrel shifter can be narrowed. Particularly, if the maximum code length is an nth power of two, the number of bits representing the shift input value decreases. Thus, the shift input for the barrel shifter can have a smaller bit width.
In still another embodiment, the inventive variable-length code decoder may include, in combination: the interface section including the accumulation register, adder, input register and barrel shifter; and the decoding section including the barrel shifter, barrel shifter register and lookup table.
According to such an embodiment, the output of the barrel shifter of the interface section is directly input to the barrel shifter of the decoding section, and the output of the latter barrel shifter is written on the barrel shifter register. Accordingly, the decoder may have a reduced number of barrel shifter registers.
In an alternative embodiment, the inventive variable-length code decoder may include, in combination: the interface section including the accumulation register, adder, input register and barrel shifter; and the decoding section including the barrel shifter, first and second barrel shifter registers, lookup table and shift length register.
According to this embodiment, an N-bit contiguous data sequence, including a variable-length codeword to be decoded, can be selected from the output of the barrel shifter of the interface section, and then decoded sequentially.
In the decoder according to one of these two embodiments, the adder preferably obtains the sum by adding one to the sum of the code length and the remainder that have been output from the decoding section and the accumulation register, respectively. And the lookup table preferably outputs, as the code length, a value obtained by subtracting one from the code length of the codeword.
According to this embodiment, the range of shift input values for the barrel shifter can be narrowed. Particularly, if the maximum code length is an nth power of two, the number of bits representing the shift input value decreases. Thus, the shift input for the barrel shifter can have a smaller bit width. Also, there is no need to provide any code length converter.

Variable-length code decoder using barrel shifters and a look-up table

Matsushita Electric Industrial Co., Ltd.


Systems, methods and apparatus, including computer program products, are provided for saving a plurality of objects to persistent storage as part of a finalize sequence. In one implementation, a computer-implemented method may include, receiving a request to instantiate a plurality of objects; sorting the plurality of objects based on a priority assigned to each of the plurality of objects before the request to instantiate the objects is received; and saving in sequence the sorted plurality of objects to the persistent storage.

I. Field
This application relates to data processing and, more particularly, to saving objects to a database as part of a finalize sequence.
II. Background and Material Information
In a client-services architecture, a client system, such as a computer, may call an application, such as a service or web service, at a server to interact with the application through the Internet or an intranet. A service, such as a web service, is an application (or program) that makes itself available over the Internet or an intranet, uses standardized messaging, such as XML (extensible Markup Language) and Simple Object Access Protocol (SOAP), and uses some type of location mechanism, such as UDDI (Universal Description, Discovery, and Integration), to locate the service and its public Application Program Interface (API).
To call a service through the Internet or intranet, the client system makes a call though an API, which defines the way the client communicates with the service. The service instantiates objects, such as business objects, in response to the API call. As used herein, the term "instantiate" means, in an object oriented programming environment, producing an object of a particular class and, more generally, includes deploying, customizing, running and/or executing an application. As used herein, an "object" means a software bundle of variables (e.g., data) and related methods. For example, in object-oriented programming, an object is a concrete realization (instance) of a class that consists of data and the methods associated with that data. The phrase "business object" refers to a software bundle of data and related methods that can be used for describing a business process (or task).
An example of a service is a "catalog" service, which can be called through the Internet by a client system. The catalog service may allow a user at a client system to view and purchase products. FIG. 3 depicts some of the business objects that may be associated with the catalog service. The business objects may, for example, correspond to data listing each product (business object 402), product descriptions 404, available quantity 406 (e.g., quantity of products available in stock), and quantity ordered 408. When a client system calls the catalog service, the catalog service instantiates business objects 402-408, allowing objects 402-408 to retrieve from a database data and method associated with those objects. The retrieved data may then be buffered for the transaction with the client system. At some point (e.g., during or after the transaction), the business objects would be saved in a database for persistent storage. This allows any changes to be "distributed" so that other services and/or business objects can access any changes associated with the business object.
Before a business object is saved to persistent storage and thus distributed, a finalize sequence may be performed. The finalize sequence may constitute a sequence of one or more steps performed to ensure that the proper data (or information) is saved to persistent storage. For example, when a finalize sequence is triggered, a business object may be placed in a checked mode, which limits access to the business object to read only while saves of business objects 402-408 to persistent storage are performed. The business object may then be recomputed before a save to account for any changes caused by other business objects that may have written to the business object. Next, the finalize sequence may include a "do save" mode which saves the business objects (e.g., the data and methods of the business object) to persistent storage.
When a business object writes to another business object, the sequencing of the saves to persistent storage may influence whether the saves associated with other business objects are performed correctly, e.g., whether the correct data is being saved. Specifically, if business object 402 writes to business object 406 and business object 408, while business object 406 writes to business object 408, the sequencing of any saves to persistent storage during the finalize sequence may not accurately record the true state of the data at business object 408 since two different business objects (namely 402 and 406) have written to (and thus changed) business object 408. The above example illustrates that there are cross dependencies between business objects that affect how business objects should be saved to a persistent storage mechanism, such as a database.


A method and a device for synchronizing broadcast of streaming data by a transmitting data processing unit to a plurality of receiving data processing units is provided. After a data word has been sent, a synchronizer in the transmitting data processing unit collects an acknowledge signal from each of the receiving data processing units and then generates an indication that the next data word can be transmitted. This allows to speed-up data delivery to parallel working processing units in a system-on-a-chip since data delivery has no longer to account for a maximum predictable latency of the respective receiving units.

The present invention relates to the synchronization of data streams for broadcast applications. More specifically, the invention relates to a device and a method for simultaneous data delivery in a system-on-a-chip environment.
Large Systems-on-a-Chip (SOCs) usually consist of several building blocks each of them comprising data processing units, potentially together with a local controller, that perform some sort of defined (sub-) task. Such SoCs are employed for mobile communication applications, e.g., but not exclusively.
In the case of an SoC for wireless communication applications, these building blocks are the various components of the transmit and receive system, such as for example an input filter unit, a demodulation unit, a forward error correction (FEC) unit, a fast Fourier transform (FFT) unit, a parameter estimation unit and the like, which components will be coupled to each other in a chain, ring, or some combination of such schemes, depending on the data processing algorithms used. With such an architecture, it might be desired or necessary for a particular unit or processing stage to simultaneously deliver the same data to two or more subsequent processing units or stages, which units will then work in parallel using the same input data to perform different processing tasks. To give an example, a data element can be transferred to two filters which work in parallel to each apply a different filter function on the same input data element.
More generally speaking, there is a system, where data streams have to be broadcasted by a transmitting unit to a plurality of receiving units which is exemplified in FIG. 1 by transmitter 10 and receivers 1-3. Since each data stream to a respective receiver has a different speed and each receiver acts independently, the transmitter, after having sent a first data word, Data1 in FIG. 1, has to wait a predefined time which accounts for the maximum predictable latency of the respective receivers before the second data word, Data2, is transmitted to ensure that all receivers have received the first data word before the second data word is delivered.
It is an object of the present invention to accelerate processing in systems-on-a-chip. More particular, an object of the invention is to speed-up data delivery to parallel working processing units.

Method and device for synchronizing data broadcasts for system-on-chip


The present invention provides: a vinylpyrrolidone polymer which exhibits good heat resistance and storage stability; a composition containing the vinylpyrrolidone polymer; a stabilization process for the vinylpyrrolidone polymer, and a preservation process for a vinylpyrrolidone polymer by which: even when the vinylpyrrolidone polymer is preserved for a long time or at high temperature, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer can be prevented from changing, therefore the vinylpyrrolidone polymer can stably be preserved. To enhance the heat resistance and the storage stability, a vinylpyrrolidone polymer is mixed with a certain amount of antioxidant, and the oxygen concentration is suppressed to not higher than 50,000 ppm in a gas phase that contacts with the vinylpyrrolidone polymer when preserving.

A. Technical Field
The present invention relates to: a vinylpyrrolidone polymer which is excellent in the storage stability; a composition containing the vinylpyrrolidone polymer; a stabilization process for the vinylpyrrolidone polymer; and a preservation process for the vinylpyrrolidone polymer.
B. Background Art
A vinylpyrrolidone polymer, such as poly(vinylpyrrolidone) or a vinylpyrrolidone copolymer, is widely used in various fields such as medicines, cosmetics, pressure sensitive adhesives or adhesives, paints, dispersants, inks, and electronic parts, because the vinylpyrrolidone polymer has merits or advantages of biocompatibility, safety, hydrophilicity, and so on.
However, while providing the vinylpyrrolidone polymer to the above various uses, the present applicant found that the vinylpyrrolidone polymer had problems in respect to the stability of storability and so on. For example, whether the vinylpyrrolidone polymer is a powder or solution, there were cases where the vinylpyirolidone polymer or a solution thereof got colored or underwent the reduction of the molecular weight or viscosity when stored for a long time or at high temperature.
A. Object of the Invention
An object of the present invention is to provide: a vinylpyrrolidone polymer which has extremely good storage stability and thermal stability in that even if the vinylpyrrolidone polymer is stored for a long time, coloring or other changes of physical properties occur little, and the thermal stability is also excellent, and the storage in a solution state is also possible; a composition containing the vinylpyrrolidone polymer; and a stabilization process for the vinylpyrrolidone polymer.
Another object of the present invention is to provide a preservation process for a vinylpyrrolidone polymer by which: even when the vinylpyrrolidone polymer is preserved for a long time or at high temperature, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer can be prevented from changing, therefore the vinylpyrrolidone polymer can stably be preserved.
B. Disclosure of the Invention
The present inventor diligently studied to solve the above problems. As a result, the inventor found that the above problems could be solved if the vinylpyrrolidone polymer was mixed with a certain amount of antioxidant, and further that a process, comprising the step of examining how much a K value, as defined by Fikentscher""s equation, reduced when heating the vinylpyrrolidone polymer under prescribed conditions, was good as a process for exactly judging the storage stability of the vinylpyrrolidone polymer. The inventor also found that the above problems could be solved if the oxygen concentration in a gas phase that contacts with the vinylpyrrolidone polymer was kept to a certain amount or less when preserving. The present invention has been completed on the basis of these findings.
Therefore, a vinylpyrrolidone polymer, according to the present invention, contains at least one antioxidant in a ratio of 0.00001xcx9c30 weight %, preferably 0.001xcx9c30 weight %, to the vinylpyrrolidone polymer. Another vinylpyrrolidone polymer, according to the present invention, is adjusted such that the reduction ratio of the K value defined by Fikentscher""s equation will be within 5% when the vinylpyrrolidone polymer is subjected to a forcible test in which the vinylpyrrolidone polymer is kept heated at 120xc2x0 C. under normal pressure in air for 2 hours. Yet another vinylpyrrolidone polymer, according to the present invention, is adjusted such that the reduction ratio of the K value defined by Fikentscher""s equation will be within 5% when the vinylpyrrolidone polymer is subjected to a promotion test in which the vinylpyrrolidone polymer is kept heated at 50xc2x0 C. in a solution state for 14 days.
A composition for various uses, according to the present invention, comprises a vinylpyrrolidone polymer as a resin component, and further comprises at least one antioxidant in a ratio of 0.00001xcx9c30 weight %, preferably 0.001xcx9c30 weight %, to the vinylpyrrolidone polymer.
A stabilization process for a vinylpyrrolidone polymer, according to the present invention, comprises the step of mixing the vinylpyrrolidone polymer with at least one antioxidant in a ratio of 0.00001xcx9c30 weight %, preferably 0.001xcx9c30 weight %, to the vinylpyrrolidone polymer.
A preservation process for a vinylpyrrolidone polymer, according to the present invention, comprises the step of suppressing the oxygen concentration to not higher than 50,000 ppm in a gas phase that contacts with the vinylpyrrolidone polymer.
These and other objects and the advantages of the present invention will be more fully apparent from the following detailed disclosure.
Hereinafter, a detailed description is given about a mode for carrying out the present invention.
The vinylpyrrolidone polymer in the present invention is, specifically, poly(vinylpyrrolidone) and/or a vinylpyrrolidone copolymer.
The poly(vinylpyrrolidone) is a compound of general formula (3) below:
(wherein n is an integer) and is obtained by polymerizing vinylpyrrolidone by any method as mentioned below.
The vinylpyrrolidone copolymer is a copolymer of which the constituents include vinylpyrrolidone and a comonomer copolymerizable therewith. The comonomer to be copolymerized with vinylpyrrolidone is not especially limited, but specific examples thereof include: 1) (meth)acrylate esters such as methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, cyclohexyl(meth)acrylate, and hydroxyethyl(meth)acrylate; 2) (meth)acrylamide and derivatives therefrom such as N-monomethyl(meth)acrylamide, N-monoethyl(meth)acrylamide, and N,N-dimethyl(meth)acrylamide; 3) basic unsaturated monomers such as dimethylaminoethyl(meth)acrylate, dimethylaminoethyl(meth)acrylamide, vinylpyridine, and vinylimidazole and their salts or quaternized products; 4) vinylamides such as vinylformamide, vinylacetamide, and vinyloxazolidone; 5) carboxyl-group-containing unsaturated monomers such as (meth)acrylic acid, itaconic acid, maleic acid, and fumaric acid; 6) unsaturated anhydrides such as maleic anhydride and itaconic anhydride; 7) vinyl esters such as vinyl acetate and vinyl propionate; 8) vinylethylene carbonate and derivatives therefrom; 9) styrene and derivatives therefrom; 10) 2-sulfoethyl(meth)acrylate and derivatives therefrom; 11) vinylsulfonic acid and derivatives therefrom; 12) vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and butyl vinyl ether; and 13) olefins such as ethylene, propylene, octene, and butadiene. Among these groups of comonomers, particularly, groups 1)xcx9c8) are favorable, for example, in respect to the copolymerizability with vinylpyrrolidone. As to the above comonomers, only one kind may be copolymerized with vinylpyrrolidone, or any mixture of two or more kinds of comonomers may be copolymerized with vinylpyrrolidone.
The ratio of vinylpyrrolidone to the entire monomer components of the vinylpyrrolidone copolymer is not especially limited, but is preferably not lower than 0.1 mol %, more preferably not lower than 1.0 mol %, still more preferably not lower than 5.0 mol %, most preferably not lower than 20.0 mol %. In the case where the ratio of vinylpyrrolidone in the copolymer is lower than 0.1 mol %, there are disadvantages in that various properties deriving from vinylpyrrolidone cannot be exhibited and the deterioration of the polymer to be solved by the present invention is seen little.
The polymerization reaction to give the vinylpyrrolidone polymer can be carried out by conventional polymerization methods such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, and precipitation polymerization. The reaction temperature in the polymerization reaction may fitly be set according to conditions such as reactants, but is preferably in the range of 0xcx9c250xc2x0 C., more preferably 20xcx9c150xc2x0 C., most preferably 40xcx9c100xc2x0 C.
The polymerization reaction to give the vinylpyrrolidone polymer may be carried out by adding conventional polymerization initiators, of which the specific examples include: radical polymerization initiators such as azo compounds (e.g. 2,2xe2x80x2-azobisisobutyronitrile and 2,2xe2x80x2-azobis(2-methylpropionamidine)dihydrochloride) and peroxides (e.g. benzoyl peroxide and hydrogen peroxide); and cationic polymerization initiators such as boron trifluoride or complexes thereof, iron(II) chloride, diethylaluminum chloride, diethylzinc, heteropolyacids, and activated clay. The concentration of the polymerization initiator in the polymerization reaction is not especially limited, but is preferably in the range of 0.001xcx9c10 weight %, more preferably 0.01xcx9c5 weight %, most preferably 0.05xcx9c3 weight %, of the monomer components. When the polymerization reaction is carried out, for example, any chain transfer agent, pH-adjusting agent, or buffer agent may fitly be used besides the polymerization initiator as the need arises.
The solvent, as used for the polymerization reaction to give the vinylpyrrolidone polymer, or as used when preserving the vinylpyrrolidone polymer in a solution state, is not especially limited, but examples thereof include: water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, diethylene glycol; alkylene glycol ethers (acetates) such as propylene glycol monomethyl acetate and diethylene glycol monomethyl ether acetate; amides such as dimethylformamide and N-methylpyrrolidone; esters such as ethyl acetate, butyl acetate, and xcex3-butyrolactone; aliphatic hydrocarbons such as hexane and octane; alicyclic saturated hydrocarbons such as cyclohexane; alicyclic unsaturated hydrocarbons such as cyclohexene; aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as acetone and methyl ethyl ketone; halogenated hydrocarbons such as dichloroethane, chloroform, and carbon tetrachloride; ethers such as diethyl ether, dioxane, and tetrahydrofuran; sulfonate esters such as dimethyl sulfoxide; carbonate esters such as dimethyl carbonate and diethyl carbonate; and alicyclic carbonate esters such as ethylene carbonate and propylene carbonate. Among these, particularly, the ethers (acetates) and the amides are preferable, and water and the alcohols are more preferable. These solvents may be used alone respectively or in combinations with each other. In addition, the above solvents are preferably used such that the concentration of the monomer components in the raw material mixture in the polymerization reaction can be preferably in the range of 1xcx9c99 weight %, more preferably 5xcx9c70 weight %, most preferably 10xcx9c60 weight %.
In the present invention, the stabilization of the properties, such as storability and heat resistance, of the vinylpyrrolidone polymer is designed by mixing the above vinylpyrrolidone polymer with at least one antioxidant in a ratio of 0.00001xcx9c30 weight %, preferably 0.001xcx9c30 weight %, to the vinylpyrrolidone polymer. In the case where the mixing ratio of the antioxidant is lower than 0.00001 weight %, the stabilization of the properties such as storability and heat resistance is difficult. In the case where the ratio is higher than 30 weight %, there are problems in that the inherent properties, such as strength and appearance, of the polymer are damaged.
Examples of the antioxidant usable in the present invention include:
phenolic antioxidants such as sodium salicylate, potassium salt of methylbenzotriazole, 2-mercaptobenzimidazole, 2,4-dihydroxybenzophenone, 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, stearyl-xcex2-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, propyl 3,4,5-trihydroxybenzoate, hydroquinone, and catechol;
bisphenolic antioxidants such as 2,2xe2x80x2-methylenebis(4-methyl-6-t-butylphenol), 2,2xe2x80x2-methylenebis(4-ethyl-6-t-butylphenol), 4,4xe2x80x2-thiobis(3-methyl-6-t-butylphenol), 4,4xe2x80x2-butylidenebis(3-methyl-6-t-butylphenol), 3,9-bis[1,1-dimethyl-2-[xcex2-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspyrro[5,5]undecane, and 4,4xe2x80x2-(2,3-dimethyl-tetramethylene)dipyrrocatechol;
high-molecular phenolic antioxidants such as 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3xe2x80x2,5xe2x80x2-di-t-butyl-4xe2x80x2-hydroxyphenyl)propionate]methane, bis[3,3xe2x80x2-bis-(4xe2x80x2-hydroxy-3xe2x80x2-t-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3xe2x80x2,5xe2x80x2-di-t-butyl-4xe2x80x2-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol;
sulfur-containing antioxidants such as dilauryl 3,3xe2x80x2-thiodipropionate, dimyristyl 3,3xe2x80x2-thiodipropionate, distearyl 3,3xe2x80x2-thiodipropionate, 2-mercaptobenzimidazole, tetrakismethylene-3-(laurylthio)propionatemethane, and stearylthiopropylamide;
phosphorus-containing antioxidants such as triphenyl phosphite, diphenylisodecyl phosphite, phenyldiisodecyl phosphite, 4,4xe2x80x2-butylidene-bis(3-methyl-6-t-butylphenylditridecyl)phosphite, cyclic neopentanetetraylbis(octadecyl)phosphite, tris(nonylphenyl)phosphite, tris(mono- and/or dinonylphenyl)phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris(2,4-di-t-butylphenyl)phosphite, cyclic neopentanetetraylbis(2,4-di-t-butylphenyl)phosphite, cyclic neopentanetetraylbis(2,6-di-t-butyl-4-methylphenyl)phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite, distearylpentaerythritol diphophite, di(2,4-di-t-butylphenyl)phophite, and tetrakis(2,4-di-t-butylphenyl)-4,4-biphenylene phophonite;
alcoholic antioxidants such as erysorbic acid, sodium erysorbate, and isopropyl citrate;
amine antioxidants such as methylated diphenylamine, ethylated diphenylamine, butylated diphenylamine, octylated diphenylamine, laurylated diphenylamine, N,Nxe2x80x2-di-sec-butyl-p-phenylenediamine, and N,Nxe2x80x2-diphenyl-p-phenylenediamine;
hindered-amine antioxidants such as 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, dimethyl succinate-1-(2-hydroxyethyl)4-hydroxy-2,2,6,6-tetramethylpiperidine and condensed products thereof, and 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspyrro[4,5]decane-2,4-dione. These may be used alone respectively or in combinations with each other.
Among the above-exemplified antioxidants, particularly, compounds having a phenolic hydroxyl group are preferably used in the present invention, of which the specific examples include the phenolic antioxidants, the bisphenolic antioxidants, and the high-molecular phenolic antioxidants. If the compound having a phenolic hydroxyl group is used as the antioxidant, there are advantages of not increasing the ash content resultant from strong heating of the vinylpyrrolidone polymer.
As to the antioxidant, particularly, compounds of the below-mentioned general formulae (1) and/or (2) are favorably used besides the above-exemplified antioxidants in the present invention, because the deterioration of the vinylpyrrolidone polymer is, for example, considered to occur due to participation of radical species that form by cleavage of peroxides that are generated by influence of ultraviolet rays and so on, but because the radical scavengers of the below-mentioned general formulae (1) and/or (2) make resonant structures in a radicalized state, and therefore have so high radical scavengeability as to be extremely excellent in the ability to prevent the polymer from deteriorating with the passage of time.
wherein each of R1, R2, R3, R4, and R5 is, independently of each other, at least one member selected from the group consisting of a hydrogen atom, alkyl groups, substituted alkyl groups, aryl groups, and substituted aryl groups, wherein R1 and R2, or R3 and R4, may be bonded to each other to form a cyclic structure.
Specific examples of the compound of general formula (1) above include thioformamide, thioacetamide, thiopropionamide, N-methylthioformamide, N-methylthioacetamide, and N-ethylthioformamide, and specific examples of the compound of general formula (2) above include thiourea, N,Nxe2x80x2-dimethylthiourea, N,Nxe2x80x2-diethylthiourea, N,Nxe2x80x2-dibutylthiourea, N,Nxe2x80x2-diphenylthiourea, ethylenethiourea, and propylenethiourea, but there is no limiation thereto. Among them, particularly, cases where R4 and/or R5 in formula (2) is a hydrogen atom, in other words, cases where the compound of this formula is thiourea or a derivative therefrom, are preferable because, in such cases, the compound can make four kinds of resonant stabilized structures in a radicalized state and therefore has the highest radical scavengeability. When these compounds of general formulae (1) and/or (2) are used, the amount thereof is preferably in the range of 0.00001 to 10 weight %, more preferably 0.005 to 1 weight %, of the vinylpyrrolidone polymer.
In the present invention, moreover, it is preferable that the radical scavenger is jointly used with a peroxide decomposer. The joint use of the radical scavenger with the peroxide decomposer makes synergistic effects upon the prevention of the deterioration of the vinylpyrrolidone polymer, and therefore can maintain the effects for a longer time or at higher temperature than cases where they are used alone respectively.
The above peroxide decomposer reduces either undecomposed residue of peroxides as used for producing the vinylpyrrolidone polymer, or peroxides which form due to factors such as oxidation of radical species while the vinylpyrrolidone polymer is, for example, preserved or transported. Specific examples of the peroxide decomposer include those which are previously enumerated as the specific examples of the sulfur- or phosphorus-containing antioxidant among the above-exemplified antioxidants. When these peroxide decomposers are used, the amount thereof is preferably in the range of 0.00001 to 10 weight %, more preferably 0.005 to 1 weight %, of the vinylpyrrolidone polymer.
The aforementioned radical scavenger scavenges radicals, which are generated by influence of light, heat, and so on while the vinylpyrrolidone polymer is, for example, preserved or transported, with the result that the radicals are prevented from being chained to frameworks of the polymer. Specific examples of the radical scavenger include, among the above-exemplified antioxidants, those which are previously enumerated as the specific examples of the phenolic antioxidant, the bisphenolic antioxidant, the high-molecular phenolic antioxidant, the alcoholic antioxidant, the amine antioxidant, and the hindered-amine antioxidant, and further, those which are previously enumerated as the specific examples of the compound of general formula (1) and/or (2). In the present invention, among these, particularly, the phenolic antioxidants, the bisphenolic antioxidants, the amine antioxidants, the hindered-amine antioxidants, and thiourea and derivatives therefrom are preferable, and thiourea and derivatives therefrom are more preferable. When these radical scavengers are used, the amount thereof is preferably in the range of 0.00001 to 10 weight %, more preferably 0.005 to 1 weight %, of the vinylpyrrolidone polymer.
In the present invention, it is preferable that the vinylpyrrolidone polymer further contains a radical formation inhibitor, because mixing of this radical formation inhibitor might make more synergistic effects upon the prevention of the deterioration of the vinylpyrrolidone polymer. Specific examples of the radical formation inhibitor include conventional ultraviolet absorbent, metal-deactivating agents, and quenchers. When these radical formation inhibitors are used, the amount thereof is preferably in the range of 0.00001 to 10 weight % of the vinylpyrrolidone polymer.
In the present invention, the method for mixing the vinylpyrrolidone polymer with the antioxidant (including the radical scavenger and the peroxide decomposer) and further, as the need arises, with the radical formation inhibitor is not especially limited, but, in a preferable method, these additives are added to a reaction liquid resultant from the polymerization reaction, or to a solution or dispersion of the vinylpyrrolidone polymer which is obtained by dissolving or dispersing a powder of the vinylpyrrolidone polymer into a solvent.
When the vinylpyrrolidone polymer according to the present invention is formed into an aqueous solution with a concentration of 5 weight %, its pH is preferably in the range of 4 to 12, more preferably 5 to 9. In these pH regions, the stabilization effect due to the antioxidant in the present invention can be exhibited still more effectively. In the case where pH is on the more acidic side than 4, the oxidation deterioration easily occurs, therefore the durability of the aforementioned stabilization effect tends to be damaged.
According to the present invention, the storage stability of the vinylpyrrolidone polymer can surely be judged by the following process. The vinylpyrrolidone polymer or a composition, which is prepared by mixing the vinylpyrrolidone polymer with a storage-stabilizing agent such as antioxidant, is subjected to a forcible test in which the vinylpyrrolidone polymer or the composition is kept heated at 120xc2x0 C. under normal pressure in air for 2 hours. Before and after this forcible test, the vinylpyrrolidone polymer is dissolved into any solvent, in which the vinylpyrrolidone polymer is soluble, in a concentration of not higher than 10 weight %. The respective viscosities of the resultant solutions are measured at 25xc2x0 C. with a capillary viscometer. Respective K values are determined from the resultant measured values, wherein the K values are defined by Fikentscher""s equation. Incidentally, in the case where the judgment of the storage stability of the vinylpyrrolidone polymer is carried out in a solution state, the vinylpyrrolidone polymer is subjected to a promotion test in which the vinylpyrrolidone polymer is kept heated at 50xc2x0 C. in a solution state for 14 days, and then the solution is diluted with any solvent to decrease the content of the vinylpyrrolidone polymer to not higher than 10 weight %, and then the viscosity of the resultant solution is measured to determine the K value. Then, either the reduction ratio of the K value after the forcible test to the initial value of the K value before the forcible test or the reduction ratio of the K value after the promotion test to the initial value of the K value before the promotion test is evaluated. As a result, the storage stability of the vinylpyrrolidone polymer can easily be judged. As to the vinylpyrrolidone polymer (including the composition as prepared by mixing the vinylpyrrolidone polymer with a storage-stabilizing agent such as antioxidant) which has excellent storage stability, the above reduction ratio is suppressed within 5%.
Herein, the K value is a value which is calculated from the measured viscosity and the following Fikentscher""s equation:
(log xcex7rel)/C=[(75K02)/(1+1.5K0C)]+K0
K=1000K0
wherein: C denotes the grams of the vinylpyrrolidone polymer in 100 ml of solution; and xcex7rel denotes the viscosity of the solution to the solvent.
As to the storage-stabilized vinylpyrrolidone polymer according to the present invention (i.e. the vinylpyrrolidone polymer which is adjusted such that the reduction ratio of the K value defined by Fikentscher""s equation will be within 5% when the vinylpyrrolidone polymer is subjected to a forcible test in which the vinylpyrrolidone polymer is kept heated at 120xc2x0 C. under normal pressure in air for 2 hours or to a promotion test in which the vinylpyrrolidone polymer is kept heated at 50xc2x0 C. in a solution state for 14 days), its storage stabilization process by other than mixing with the aforementioned antioxidant is also adoptable providing that it involves mixing with the storage-stabilizing agent or storage stabilization process by which the above reduction ratio of the K value can be maintained.
In the present invention, as the need arises, the vinylpyrrolidone polymer may be allowed to contain, for example, various additives such as processing stabilizers, plasticizers, dispersants, fillers, aging inhibitors, pigments, and curing agents.
In the preservation process of the present invention, it is important to suppress the oxygen concentration to not higher than 50,000 ppm in a gas phase that contacts with the vinylpyrrolidone polymer. The oxygen concentration is preferably suppressed to not higher than 10,000 ppm, more preferably not higher than 1,000 ppm. The lower the oxygen concentration is, the more effectively the preservation stability of the vinylpyrrolidone polymer can be enhanced. In the case where the oxygen concentration is higher than 50,000 ppm, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer change with the passage of time when the vinylpyrrolidone polymer is preserved for a long time or at high temperature. When applying the preservation process of the present invention, product form of the vinylpyrrolidone polymer is not especially limited, but may be any form, for example, lumps, fibers, powders, solutions, films.
Herein, the gas phase is a portion other than a solid phase portion and/or a liquid phase portion as occupied by the vinylpyrrolidone polymer. The oxygen concentration in the gas phase means the absolute amount of oxygen as contained in a gas phase of a unit volume. In the case where the vinylpyrrolidone polymer is put in an airtight container, the oxygen concentration in the gas phase is a ratio of a volume as occupied by oxygen of the gas phase portion in the container under normal pressure to a volume of the gas phase portion. Incidentally, the oxygen concentration, for example, can easily be measured with commercially available oxygen analyzers such as galvanic cell diffusion types or zirconia sensor types.
A preferable example of a first means for suppressing the oxygen concentration in a gas phase that contacts with the vinylpyrrolidone polymer is a process comprising the steps of putting the vinylpyrrolidone polymer into an airtight container and evacuating the container in the preservation process of the present invention.
The specific method for evacuating the container is not especially limited, and the container may be evacuated in conventional manners. In addition, the vacuum degree is not especially limited, either, but it is preferable to achieve the vacuum such that the container may not be broken.
A preferable example of a second means for suppressing the oxygen concentration in a gas phase that contacts with the vinylpyrrolidone polymer is a process comprising the steps of putting the vinylpyrrolidone polymer into an airtight container and displacing air in the container with an inert gas and/or carbonic acid gas in the preservation process of the present invention. Particularly, it is more preferable that the displacement of air in the container (in which the vinylpyrrolidone polymer is put) is carried out with carbonic acid gas, because the preservation stability of the vinylpyrrolidone polymer is enhanced, and because the content of unreacted vinylpyrrolidone remaining in the vinylpyrrolidone polymer can be reduced by hydrolysis during the preservation. Incidentally, it is preferable that the displacement with an inert gas and/or carbonic acid gas is carried out not only after the vinylpyrrolidone polymer has been put into the container, but also in the step of transferring the vinylpyrrolidone polymer from a reservoir therefor to the airtight container. For example, it is preferable to keep conditions such as the reservoir or a transferring line in a state filled with the aforementioned gas.
The aforementioned inert gas is a gas that is poor in the reactivity, and specific examples thereof include: gases on group 0 in the periodic table, such as helium, neon, and argon; and nitrogen gas. Among these, nitrogen gas is preferable because it is easily available.
The specific method to displace air in the container with an inert gas and/or carbonic acid gas is not especially limited, but it is preferable that the volume of the gas, as introduced into the container in the displacement step with the gas, is at least 5 times as large as the capacity of the container. In addition, it is preferable that the introduction of the gas into the container is carried out after removing air by once evacuating the container, because the displacement with the gas can thereby more efficiently be carried out. Furthermore, in the case where the vinylpyrrolidone polymer is a solution, it is preferable to allow the solution to bubble by using a tool, such as a gas-introducing tube, in order to also remove oxygen as dissolved in the solution.
A preferable example of a third means for suppressing the oxygen concentration in a gas phase that contacts with the vinylpyrrolidone polymer is a process comprising the steps of putting the vinylpyrrolidone polymer into an airtight container and enclosing at least one deoxidizing agent together with the vinylpyrrolidone polymer in the container in the preservation process of the present invention.
The deoxidizing agent is not especially limited if it can remove oxygen by a chemical reaction. However, in view of the safety or the easy use, for example, those which are obtained by sealing an inorganic deoxidizing agent such as an iron powder, iron oxide, iron hydroxide, or an organic deoxidizing agent such as L-ascorbic acid, or any mixture thereof in with gas-permeable films are preferable. A moisture keeping agent to facilitate deoxidizing can be sealed together. Specifically, commercially available deoxidizing agents, such as xe2x80x9cAgelessxe2x80x9d made by Mitsubishi Gas Chemical Co., Inc., xe2x80x9cBitaronxe2x80x9d made by Toagosei Co., Ltd., and xe2x80x9cModulanxe2x80x9d made by Nippon Kayaku Co., Ltd., may be used.
In the aforementioned respective means for suppressing the oxygen concentration, the container to put the vinylpyrrolidone polymer into is not especially limited by the material or shape of the container if it can achieve the airtightness. However, containers which are so high airtight as to involve little gas absorption or leakage are preferable. Specifically, examples of the material of the container include glass, metals, and various plastics, and examples of the shape of the container include bottles, cans, and bags.
In the preservation process of the present invention, the first, second, and third means, which are aforementioned as the process for suppressing the oxygen concentration in a gas phase that contacts with the vinylpyrrolidone polymer, are used alone respectively or, preferably, in combinations with each other, whereby the oxygen concentration can effectively be suppressed.
It is preferable that the preservation process according to the present invention is applied also to the steps ranging from after the production of the vinylpyrrolidone polymer to the transfer of the vinylpyrrolidone polymer into a preservation container. For example, it is preferable to suppress the oxygen concentration to not higher than the aforementioned certain concentration in the gas phase in places such as reaction apparatuses, powdering apparatuses, drying apparatuses, reservoirs, and transferring lines just after the production.
The preservation stability of the vinylpyrrolidone polymer preserved by the preservation process of the present invention, for example, can be judged from the reduction ratio between K values before and after a forcible test as measured by the following process. The vinylpyrrolidone polymer, which is preserved in an airtight container, is subjected to a forcible test in which the vinylpyrrolidone polymer is kept heated together with the container at 120xc2x0 C. for 2 hours. Before and after this forcible test, the vinylpyrrolidone polymer is dissolved into any solvent, in which the vinylpyrrolidone polymer is soluble, in a concentration of not higher than 10 weight %. The respective viscosities of the resultant solutions are measured at 25xc2x0 C. with a capillary viscometer. Respective K values are determined from the resultant measured values, wherein the K values are defined by Fikentscher""s equation. The reduction ratio of the K value after the forcible test to the initial value of the K value before the forcible test is evaluated. As a result, the preservation stability of the vinylpyrrolidone polymer can easily be judged. If the resultant reduction ratio is within 5%, the vinylpyrrolidone polymer can stably be preserved without any change of the physical properties even for a long time or at high temperature.
The initial value of the K value of the vinylpyrrolidone polymer, to which the present invention is applicable, is not especially limited, but the present invention is preferably applied to a vinylpyrrolidone polymer having a K value in the range of 15xcx9c150, preferably 15xcx9c120. In addition, because particularly the stability of a vinylpyrrolidone polymer having a high K value is inferior, the present invention is more preferably applied to a vinylpyrrolidone polymer having a K value in the range of 60xcx9c150, preferably 60xcx9c120.
The storage-stabilized vinylpyrrolidone polymer and preserved vinylpyrrolidone polymer according to the present invention are usable for vinylpyrrolidone-polymer-containing compositions that are used in various fields such as medicines, cosmetics, pressure sensitive adhesives or adhesives, paints, dispersants, inks, and electronic parts. In addition, such a vinylpyrrolidone polymer composition, according to the present invention, means not only a composition containing the present invention vinylpyrrolidone polymer which is beforehand mixed with the storage-stabilizing agent such as antioxidant or of which the K value is beforehand adjusted, but also a composition which is not beforehand mixed with the storage-stabilizing agent, but to which there is separately added a material (such as antioxidant) that contributes to the storage stabilization of the vinylpyrrolidone polymer as things turn out.
(Effects and Advantages of the Invention)
The present invention can provide a vinylpyrrolidone polymer, wherein the vinylpyrrolidone polymer has the K value that is prevented from reducing, therefore this vinylpyrrolidone polymer exhibits good heat resistance and storage stability.
The present invention can further provide a composition which contains the vinylpyrrolidone polymer and therefore exhibits good heat resistance and storage stability.
The present invention can further provide a stabilization process by which the heat resistance and the storage stability of the vinylpyrrolidone polymer are enhanced.
By the present invention, even when the vinylpyrrolidone polymer is preserved for a long time or at high temperature, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer can be prevented from changing, therefore the vinylpyrrolidone polymer can stably be preserved. In addition, in the case where air in a container in which the vinylpyrrolidone polymer is put is displaced with carbonic acid gas, the content of vinylpyrrolidone which remains as a monomer in the vinylpyrrolidone polymer can be reduced by hydrolysis during the preservation.
Hereinafter, the present invention is more specifically illustrated by the following examples of some preferred embodiments in comparison with comparative examples not according to the invention. However, the present invention is not limited to the below-mentioned examples.
The K values in the examples and the comparative examples were calculated in the following way: the viscosity was measured by the aforementioned viscosity measurement process, that is, a process in which the relative viscosity of a 0.1xcx9c2 weight % aqueous solution of each vinylpyrrolidone polymer of the examples and the comparative examples was measured at 25xc2x0 C. with a capillary viscometer; and the resultant measured viscosity was applied to Fikentscher""s equation as aforementioned.

Vinylpyrrolidone polymer and its stabilization and preservation processes


Disclosed herein is an apparatus comprising a plurality of separators configured to forward a plurality of optical signals from a plurality of optical network terminals (ONTs) along a plurality of single mode waveguides, a mode coupler coupled to the single mode waveguides and configured to receive the optical signals from the plurality of separators and combine the optical signals into a multi-mode waveguide, and an optical receiver coupled to the mode coupler via the multi-mode waveguide and configured to detect the optical signals. Also disclosed is a method comprising receiving a plurality of single mode optical channels, coupling the single mode optical channels into a multimode channel, and detecting the optical modes corresponding to the channels in the multimode channel.

The increase in Internet traffic and emerging multimedia applications, such as video on demand, high definition Television (TV), video conference, and interactive online games requires an increase in bandwidth of access networks. To satisfy the increase in bandwidth and support such applications, Time Division Multiplexing (TDM) Passive Optical Networks (PONs), such as Gigabit PONs (GPONs) and Ethernet PONs (EPONs), are currently deployed worldwide to potentially serve millions of users. Traditionally, the maximum transmission distance of a PON is less than or about 20 Kilometers (km) and the splitting ratio is from about 1:16 to about 1:64, as defined in International Telecommunication Union (ITU) Telecommunication Standardization Sector (ITU-T) and Institute of Electrical and Electronics Engineers (IEEE) standards. The splitting ratio is the ratio of one central office equipment, e.g. an Optical Line Terminal (OLT), to a plurality of user equipments, e.g. Optical Network Terminals (ONTs).
Recently, there has been interest in long-reach and large splitting ratio PONs that have transmission distances larger than about 20 km and splitting ratios larger than about 1:64. In such long-reach and large splitting ratio PONs, the number of central offices, which can serve the same quantity of user terminals, can be substantially reduced. Additionally, the hierarchy of the PON can be simplified, the equipment and operation cost can be reduced, and the quality of service for real-time traffic (e.g. video on demand) can be improved due to the reduced number of hops in the system. Accordingly, ITU-T has defined a standard (ITU-T G.984.6) for GPONs with reach extension. In this standard, optical amplification and/or Optical-Electrical-Optical (OEO) regeneration are considered for long-reach PON implementations. Using optical amplifiers or optical regenerators, long-reach PONs having transmission distances up to about 100 km have been demonstrated. However, the optical amplifiers or generators are active equipment that can increase the cost and/or maintenance requirements in the system, which may be unattractive for large scale deployment. Achieving long-reach PONs without optical amplifiers or regenerators remains attractive but difficult.

This patent is subject to a terminal disclaimer.

Passive optical networks with mode coupling receivers


Disclosed are a display control apparatus and method for controlling the display of a matrix display panel. An image displayed on an FLC panel, for example, is partitioned into a plurality of bands each composed of a plurality of lines of image data, non-interlaced scanning is performed within one band obtained by partitioning, interlaced scanning is performed in band units, and the scanning direction of a first band and the scanning direction of a second band neighboring the first band are made the opposite of each other. As a result, it is possible to prevent a decline in image quality after half-tone processing as well as the occurrence of flicker caused by crosstalk peculiar to matrix displays.

1. Field of the Invention
This invention relates to a display control apparatus and method. More particularly, the invention relates to a display control apparatus and method for a display equipped with, e.g., ferroelectric liquid crystal serving as an operating medium for display update, wherein the state of a display updated as by application of an electric field is capable of being retained.
2. Description of the Related Art
Recent advances in increasing computer processing speed have made it possible to apply computers in a variety of fields in which such application was not feasible in the past. Computers can now be used as the nucleus in multimedia systems in which such media as CDs (compact disks), TV (television) and video tape, etc.
This has been accompanied by the need for specifications for accommodating multimedia in flat-panel displays typified by liquid-crystal displays. For example, in order to display a TV picture or a picture from video tape, the number of display colors desired is at least 260,000.
A ferroelectric liquid-crystal display (hereinafter referred to as an "FLCD") using ferroelectric liquid crystal (hereinafter referred to as "FLC") differs from other types of liquid-crystal displays in that it possesses a "memory" capability. This means that the liquid crystal has a characteristic which allows it to retain the state of a display changed by application of an electric field. By virtue of the memory capability, a display device using FLC suffers no decline in contrast regardless of the number of scanning lines, thus making it possible to realize a large-screen, high-definition display. This feature has been exploited to apply FLCDs to displays in DTP (desktop publishing) systems. With an FLCD panel, however, only two states, namely light and dark, can be expressed by a single pixel. In a case where an image, such as a TV image, containing many gray levels and colors is displayed, it is necessary to execute binary digital processing typified by error diffusion processing and to combine a plurality of pixels to increase the number of grays and the number of colors.
The applicant has previously proposed techniques for displaying images binarized by the error diffusion method. For example, see the specifications of CFM501US (application Ser. No. 08/246,720, filed on May 20, 1994); CFM502US (application Ser. No. 08/243,929, filed on May 17, 1994); CFM503US (application Ser. No. 08/248,511, filed on May 24, 1994); CFG118US (application Ser. No. 08/246,724, filed on May 20, 1994); CFO9174US (application Ser. No. 08/061,026, filed on May 15, 1993); and CFO9177US (application Ser. No. 08/062,214, filed on May 18, 1993).
Error diffusion processing involves an operation of the kind shown in FIG. 17. Specifically, the difference in density between input multivalued pixel data and binary data obtained by binarizing the input data is diffused to the input data of neighboring pixels to be processed subsequently, with weighting being applied to these pixels. Density is preserved. Though the number of colors that can be expressed on the FLCD by error diffusion processing is increased, a decline in image quality and resolution with respect to the original image is unavoidable. Accordingly, in order to improve image quality and resolution when a TV picture is displayed using an FLCD, it is required that first and second fields of an NTSC image signal sent at 2:1 interlacing be combined to produce one frame, after which non-interlaced error diffusion processing is executed.
However, even if error diffusion processing is carried out in frame units, image quality deteriorates when 2:1 interlaced scanning according to the NTSC is used as the scanning method in presenting a display on an FLCD. The reason for this is that since error diffusion processing diffuses error to a neighboring line (the bottom line in the example of FIG. 17), an image in which error is not diffused correctly is displayed for a certain period of time when one line is skipped by interlacing.
The situation is as illustrated in FIG. 18, in which F1 and F2 represent items of binarized frame data obtained by error diffusion processing, with F1 being a first frame of binary data and F2 being a second frame of binary data. When these are subjected to 2:1 interlaced scanning, the content of the display changes in the manner shown at (a), (b), (c), (d) in FIG. 18. In the state shown at (c), the second field of the first frame and the first field of the second frame mix together and a lower line to which error should be diffused does not exist regardless of the field. The result is poor expression of half-tones and an extremely unattractive image. Thus, when binary data that has been subjected to error diffusion processing in frame units is displayed on an FLCD, a problem in terms of image quality arises with 2:1 interlaced scanning. For this reason, it has been construed heretofore that better image quality is obtained when a display is presented using non-interlaced scanning.
Generally, when non-interlaced scanning is performed at a frequency of less than 50 Hz using a CRT, flicker is produced. With an FLCD, on the other hand, there is comparatively little flicker, even when non-interlaced scanning is performed at less than 30 Hz, owing to the aforementioned memory capability of FLC. However, when non-interlaced scanning is carried out, crosstalk that is peculiar to a matrix display occurs depending upon the pattern displayed and, as a result, some fluctuation in luminance occurs at 30 Hz. This can lead to even more flicker than is encountered with a CRT.


A phase recovery circuit for avoiding noise interfering with the clock signal generated from an oscillator is disclosed. The phase recovery circuit includes a noise detector, a phase detector, and a phase locker. The noise detector detects noise and accordingly generates a noise detecting signal. The phase detector is triggered by the noise detecting signal for detecting the phase of the clock signal and accordingly generating a phase detecting signal. The phase locker locks the phase of the clock signal to a predetermined phase within a predetermined period after the occurrence of the noise detecting signal, and after the predetermined period, the phase locker releases the clock signal. In this way, the phase of the clock signal is not affected by noise.

1. Field of the Invention
The present invention relates to an oscillator, and more particularly, to an oscillator free from being interfered by a noise signal.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 is a diagram illustrating an oscillator 100 according to the prior art. The conventional oscillator 100 is a ring oscillator with odd numbers of inverters connected in series, and each of the inverters couples between a voltage source VDD (providing a voltage VDD) and a voltage source VSS (providing a voltage VSS) respectively. Voltage source VDD in FIG. 1 is served as a power source while voltage source VSS is served as a ground end (e.g., GND). In addition, the conventional oscillator 100 can further include a buffer B coupled to an output end of the oscillator 100, for receiving a clock signal CLK and buffering clock signal CLK to generate a clock signal CLKB accordingly. Buffer B can be implemented by an amplifier or a comparator. Additionally, In FIG. 1, buffer B is used to enhance signal magnitude of clock signal CLK, thereby generating clock signal CLKB with a stronger driving ability than clock signal CLK, or, adjusting waveform of clock signal CLK to generate clock signal CLKB with a square wave more perfectly. In this way, the improved clock signal CLKB hence is more suitable for follow-up process.
However, oscillator 100 generates clock signal CLK with errors, e.g. phase errors, when noise signals exist on voltage source VDD and/or voltage source VSS.
Please refer to FIG. 2, a diagram illustrating a first condition of clock signal CLK while being interfered by a noise signal carried from the voltage source (i.e., VDD or VSS). As shown in FIG. 2, when the noise signal exists on voltage source VDD or voltage source VSS, clock signal CLK, which originally ought to keep logically high at this time, is changed to be logically low, owing to the interference from the noise signal. In such condition, the clock signals CLK interfered by the noise signal may be unsuitable for use.
Please refer to FIG. 3; a diagram illustrating a second condition of clock signal CLK interfered by the noised signal. As shown in FIG. 3, the dashed line indicates that clock signal CLK should be changed to logically low. However, the noise signal exists on voltage sources VDD/VSS, clock signal CLK, at this time, and hence keeps clock signal CLK logically high rather than logically low. In such condition, clock signal CLK interfered by the noise signal may be insuitable for use as well.


Surface light source device having a light conducting member, a light source, a light diffusing member disposed on a front light incidence surface side of the light conducting member, and a light reflecting member arranged on a rear side of the light conducting member; and a refractive index of the light conducting member is arranged to be constant for a distance from the light incidence surface and then to be varied so as to be smaller as farther from the light source, to obtain a bright and uniform brightness distribution.

a) Field of the Invention
The present invention relates to a surface light source device which is used in back light systems of liquid crystal display devices.
b) Description of the Prior Art
FIG. 1 is a cross-sectional view showing a conventional surface light source device. In FIG. 1, the numerical reference 1 represents a linear light source such as a cold cathode ray tube, 2 a light conducting member made of a transparent material, 3 a light diffusing member and 4 represents a light reflecting member. In the surface light source device shown in FIG. 1, a light emitted from the light source 1 is made incident upon a light incident edge surface 2a of the light conducting member 2 and then introduced into the member 2. The light is transmitted inside of the member 2 to an opposite edge surface 2d side, being totally reflected by a front surface (a light emitting surface) 2b and a rear surface 2c of the light conducting member 2. On the rear surface 2c of the light conducting member 2, a coarse surface is arranged, a multiplicity of conical or polygonal unevenness is provided, or a pattern constituted of a multiplicity of fine diffusing portions is formed by printing to change a part of returning light, which is directly reflected by the rear surface 2c or passed through the rear surface 2c and then reflected by the light reflecting member 4, into diffusion light. The diffusion light is emitted from the front surface 2b (light emitting surface) of the light conducting member 2; and then passes through the light diffusing member 3 to form a surface light source of the liquid crystal display device.
If the distribution of the coarse surface, the heights and the top angles of the conical or polygonal-shaped unevenness, or the area and distribution density of the fine diffusing portions of the printing pattern, which is formed on the rear surface 2c of the light conducting member 2, is varied in a suitable manner, a uniform brightness distribution of the light emitted from the light emitting surface 2b of the light conducting member 2 can be obtained.
However, in the above-stated conventional surface light source device using a light conducting member, when the distribution of the coarse surface formed on the rear surface of the light conducting member, the heights of the conical or polygonal-shaped unevenness or inclined angles of the top portions thereof, or the variation of the distribution density of the printing pattern is not suitable, it is impossible to obtain a uniform brightness distribution of the light emitted from the light emitting surface, i.e. the light emitted from the light diffusing member. Therefore, in the conventional device, an arrangement of the above-said coarse surface distribution and its variation is very important to obtain a uniform surface light source. However, it is not so easy to obtain an optimum coarse surface distribution and its variation, and thus difficult to form the suitable coarse surface distribution, etc. on the rear surface of the light conducting member as designed first.


A ceramic composition for forming a ceramic dielectric body having a dielectric constant of less than about 5.0 and a TCE of 2.0-4.0 ppm/c. The composition is formed from a mixture comprising 25-50 weight percent of a low temperature glass selected from the group consisting of borosilicate glass, zinc borate glass and combinations thereof, 50-75 weight percent of a high temperature glass selected from the group consisting of high silica glass, titanium silicate glass and combinations thereof, and 1-10 weight percent of ceramic material having a particle size of less than about 3 microns. The mixture can be combined with a polymeric binder to produce an unfired green tape which is co-fireable with high conductivity metallurgies such as gold, silver and silver/palladium. A preferred ceramic material is colloidal alumina.

Conventionally, alumina (Al.sub.2 O.sub.3) is used as a dielectric material for microelectronic packages. It has excellent electrical (insulating), thermal and mechanical (especially strength) properties. Alumina based packages, generally containing 4-10 wt. % glass, require sintering temperatures above 1500.degree. C. which necessitates the use of refractory metals such as molybdenum or tungsten for the electrical interconnections so that the metal can be co-fired with the package. These metals have poor electrical conductivity as compared to highly conductive metals such as copper, and secondly, they require the use of strongly reducing atmospheres during co-firing necessitating expensive furnace systems.
The development of multilayer ceramic circuit boards is toward higher frequency, high density and higher speed devices. Al.sub.2 O.sub.3 has a relatively high dielectric constant of about 9.9, causing high signal propagation delay and low signal-to-noise ratio (crosstalk). The signal propagation delay (t) in ceramic substrates is affected by the effective dielectric constant of the substrate (k') in the following equation: EQU t=(k').sup.0.5 /C
where C is the speed of light. It can be found that the signal propagation delay can be dramatically reduced by a reduction in the effective dielectric constant of the substrate. For example, if the dielectric constant of a material is reduced from 10 (approximately the k' of Al.sub.2 O.sub.3) to 5, the signal propagation delay can be reduced by 30%. A small signal delay is especially important for the substrate housing a chip with a very dense integrated circuit, for instance, very large scale integrated circuit (VLSI).
Furthermore, alumina has a coefficient of thermal expansion of about 7.4.times.10.sup.-6 /.degree.C. (in the 20.degree.-200.degree. C. range) as compared to 3.4.times.10.sup.6 /.degree.C. for silicon. This mismatch in thermal expansion results in design constraints and reliability concerns when attaching a silicon wafer to the substrate.
Heretofore, most of the dielectric materials used in multilayer circuits have been conventional thick film compositions. A typical circuit is constructed by sequentially printing, drying and firing functional thick film layers atop a ceramic substrate which is usually 92-96 wt. % Al.sub.2 O.sub.3. The multiple steps required make this technology process intensive with the large number of process steps and yield losses contributing to high costs. Thick film technology nevertheless fills an important need in microelectronics and will continue to do so in the foreseeable future.
Recently, dielectric thick film compositions with a low dielectric constants of 5 have been introduced. However, ceramic substrates with low dielectric constants less than 5.0 and thermal expansion coefficients equal to that of silicon (3.4 ppm/.degree.C.) and GaAs (6.1 ppm/.degree.C.) are not readily available.
Low temperature co-fired (LTCF) technology has been recently introduced as a method for fabricating multilayer circuits. This technology offers the combination of the processing advantages of HTCF technology and the materials advantages of thick film technology. These LTCF tape systems have firing temperatures below 1000.degree. C. and allow the use of high conductivity metals such as silver, gold, silver/palladium and copper (copper, however, requires reducing atmospheres). Most of these tape systems have dielectric constants between 6 and 8 and encompass a range of thermal coefficient of expansion (TCE).
A method for producing a multilayer ceramic circuit board for use with copper conductors is described in U.S. Pat. No. 4,642,148, issued to Kurihara et al. Ceramic compositions comprising 10-75 wt. % alpha-alumina, 5-70 wt. % non-crystalline quartz (fused silica), 20-60 wt. % borosilicate glass are disclosed. The dielectric constants of the fired materials ranged from 4.8 to 9.6.
U.S. Pat. No. 4,642,148 issued to Kurihara et al describes a method for producing a multilayer ceramic circuit board for use with copper conductors. Ceramic compositions comprising 10-75 wt. % alpha-alumina, 5-70 wt. % non-crystalline quartz (fused silica), 20-60 wt. % borosilicate glass are disclosed. The dielectric constants of the fired materials ranged from 4.8 to 9.6.
U.S. Pat. No. 4,672,152 issued to Shinohara et al describes a multilayer ceramic circuit board in which the ceramic is prepared from a mixture of 50-95 wt. % crystallizable glass and 5-50 wt. % ceramic filler. The material has a dielectric constant between 5.1 and 6.0 and a flexural strength above 150 MPa. The crystallizable glass consists of 5-20 wt. % lithium oxide, 60-90 wt. % silicon dioxide, 1-10 wt. % aluminum oxide and 1-5 wt. % alkaline metal oxide other than lithium oxide. The ceramic filler is selected from the group of silicon dioxide, .beta.-eucryptite (LiAlSiO.sub.4) and aluminum oxide.
U.S. Pat. No. 4,939,021 issued to Aoki et al describes a describes a multilayer ceramic copper circuit board comprising a glass/ceramic composite having a low dielectric constant and a low thermal expansion coefficient, and copper conductors having a low electrical resistivity. The glass/ceramic composite consists of a mixture of 3% to 75% by weight of mullite, 25% to 97% by weight borosilicate glass and 0% to 72% by weight quartz glass.
There exists a need for a low temperature co-fireable tape dielectric which (1) has a low dielectric constant (less than 5.0), (2) has a thermal expansion coefficient very close to the value for silicon (3.4 ppm/.degree.C.), and (3) can be fired in air at a low temperature (less than 950.degree. C.), thus permitting the use of high conductivity metallurgies such as gold, silver and silver/palladium.
The principal object of the invention is to provide a material that can be sintered into a body that has a dielectric . constant of less than 5.0 at 1 MHz, a thermal expansion coefficient in the range of 2.0-4.0 ppm/.degree.C.).
Another object of the invention is to provide ceramic materials that are sintered at temperatures less than 950.degree. C. for 4-20 hours without significantly increasing their thermal coefficient of expansion.
Another object of the invention is to provide ceramic materials that are sintered at low temperatures to produce dense bodies (greater than 95% of theoretical density) having low coefficients of thermal expansion and a dielectric constant below 5.0 and have a glass content below 50 vol. %. A reduction in the glass content of the sintered body is very desirable in that the glassy phase is responsible for shape distortion or warpage during co-firing. If the sintered body is to be used in an electronic package, the shape distortion associated with high volume percent glass content can cause the via holes to misalign during co-firing of the metal and ceramic. A glass content below 50 vol. % will reduce the likelihood that warpage will occur.
These and other objects and advantages of the present invention will be more fully understood and appreciated with reference to the following description.

Suppression of crystal growth in low dielectric inorganic composition using ultrafine alumina


A liner assembly (322) for a sand trap (10) includes a retainer layer (329) that is positioned between a base (18) of the sand trap (10) and a filling material (16) within a cavity (13) of the sand trap (10). The retainer layer (329) is covered by the filling material (16) so that the retainer layer (329) is substantially unexposed. The retainer layer (329) includes a plurality of spaced apart projections (330) that can be formed from plastic, such as synthetic turf material. In certain embodiments, the filling material (16) fills the spaces between the projections (330). The retainer layer (329) can be substantially water impermeable and can cover at least approximately a majority of the surface area of the cavity (13). The retainer layer (329) can be positioned within the cavity at an angle (328) that is at least 10 degrees relative to the horizontal (300).

Golf technology is advancing at a rapid pace. Equipment has improved, allowing players to hit golf balls farther than ever before, with greater accuracy. In an attempt to keep up with modern golf technology, new golf courses are being constructed and older courses are being renovated to enhance the level of difficulty. As a result of this effort, the number and size of sand traps have increased.
Unfortunately, sand traps require a substantial amount of maintenance and grooming. For example, because sand traps often are positioned near existing grasses, shrubs or other plantings, growth of these plantings can spread into the sand trap, which may be undesirable on certain types of golf courses. Additionally, sand traps can retain water from precipitation and/or irrigation, resulting in slow drainage and/or ponding of water within the sand trap. These types of conditions can result in frustrated golfers or even unplayable conditions, both of which can cause economic losses for golf course owners.


A cable interface connection structure includes a jack and a plug. The plug is received in the jack. The jack includes a case, a support body, and a plurality of pins. The pins are received in the support body, and the support body is received in the case. The jack defines two rows of the pins. The plurality of pins in each row is the same. The plug includes two rows of contact terminals. A plurality of contact terminals in each row is the same. The pins are coupled to the contact terminals.

1. Technical Field
The present disclosure relates to a communication interface connection structure, and more particularly to a cable interface connection structure.
2. Description of Related Art RJ45 ports are commonly used for data transmission in network interfaces. One RJ45 port connects to one cable. Thus, two or more RJ45 ports are required to connect to two or more cables. However, space of the network interfaces may be too limited to add more RJ45 ports.


A liquid crystal display apparatus including a gate driving circuit disposed on a liquid crystal display is provided. The apparatus further includes a data driving chip, disposed on the liquid crystal display panel, to apply data driving signals to data lines. The gate driving circuit includes a plurality of stages connected to one another in parallel. The odd-numbered stages of the stages each apply gate driving signals to odd-numbered gate lines of the gate lines, in response to a first clock signal and the even-numbered stages of the stages each apply the gate driving signals to even-numbered gate lines of the gate lines, in response to a second clock signal having an opposite phase from a phase of the first clock signal.

1. Field of the Invention
The present invention relates to a gate driving circuit and a display apparatus, more particularly to a liquid crystal display apparatus including a gate driving circuit integrated into a liquid crystal display panel.
2. Description of the Related Art
Liquid crystal display (LCD) apparatuses include an LCD panel having a liquid crystal layer interposed between two substrates. LCD panels include a display area and peripheral areas surrounding the display area. The display area includes a plurality of gate lines, a plurality of data lines arranged in a direction perpendicular to that of the gate lines and a plurality of thin film transistors (TFTs) connected between the gate lines and the data lines. The peripheral areas include a gate driving circuit for sequentially outputting gate driving signals to the gate lines and a data driving circuit for outputting data signals to the data lines.
In large LCD apparatuses, the gate driving signals applied to gate lines may be delayed due to the longer gate lines and the greater number of TFTs. The gate driving signals may be further delayed because the gate driving signals are provided to adjacent stages included in the gate driving circuit. Thus, the operational properties of the gate driving circuit may be deteriorated. Further, the gate driving circuit is arranged in parallel with the data driving circuit integrated into the peripheral areas of the LCD panel such that the LCD apparatus has a symmetric structure. In this case, the Black Matrix (BM) width of the LCD apparatus is increased. Thus, a need exists for an LCD apparatus capable of improving the operational properties of the gate driving circuit and of reducing the BM width.

Gate driving circuit and display apparatus having the same