An image forming apparatus includes a controller for controlling at least a photoconductor drum and a fuser to operate independently of each other. In such an apparatus, at least one of the photoconductor drum and the fuser is provided with an electrical or mechanical member, such as a clutch for selectively coupling a driving system and a rotary member, which is operative independently, and the controller provides such a control that the electrical or mechanical members of the photoconductor drum and the fuser are responsive to signals applied thereto to start or stop the operations independently in timing, respectively.

1. Field of the Invention
The present invention relates to an image forming apparatus, and more particularly to the apparatus wherein at least a photoconductor drum and a fuser may be operative independently of each other.
2. Description of the Prior Art
Hitherto, in an image forming apparatus such as an electrophotographic printer, an electrically charged photoconductor drum is illuminated with a light source to form an electrostatic latent image on a surface thereof, a developing is performed upon adhesion of a toner to the electrostatic latent image, and then the thus obtained toner image is transferred to a recording material.
FIG. 9 shows a conceptual view for explanation of an electrophotographic process in the image forming apparatus. The electrophotographic process comprises a photoconductor drum 11 having a photoconductive surface on an outer periphery thereof, an electrostatic charger 12 for uniformly charging the photoconductor drum 11, a light emitting diode array or exposure 13 for forming an electrostatic latent image corresponding to image data on the photoconductive surface, a developing unit 14 for providing electrostatic adhesion of a toner to the electrostatic latent image, a transfer unit 15 for transferring a toner image to a sheet of paper, a fuser 16 for heating and fusing the transferred toner image to penetrate through fibers of the paper, and a cleaner 17 for removing residual electrostatic charge and toner on the photoconductive surface.
During one rotation of the photoconductor drum 11, the respective processes of charging, exposing, developing, transferring, discharging and cleaning are carried out in the order named, and the fixing process is performed on a printing paper.
The developing unit 14 varies in its structure depending on a toner to be used, which consists of a single component or two components. In case of use of a toner consisting of a single component, the developing unit 14 comprises a toner replenishment roller for replenishing the toner, a developing roller for providing adhesion of the toner to the electrostatic latent image on the photoconductor drum 11 to form a toner visible image and a blade for providing a unity of thickness of the toner adhered to the developing roller.
The toner replenishment roller is rotated in conjunction with the developing roller in a slidable relation. Thus, there is generated frictional electrostatic charge between the developing roller and the toner, so that a surface of the developing roller is charged with the positive electricity (+) and the toner is charged with the negative electricity (-). As a result, the toner adheres to the developing roller. The toner adhered to the developing roller is deleted by the blade so that a thin film of the toner is formed on the surface of the developing roller.
Thus, the toner adheres to an exposure portion of the photoconductor drum 11 at a contact portion of the photoconductor drum 11 and the developing roller, so that the electrostatic latent image is visualized. As stated above, charging of the toner is performed by the frictional electrostatic charge. This brings uneven density in polarity of charge. As a result, there would occur so-called "background" wherein a toner adheres to a portion which is to be the original white part, and a scatter of the toner, thereby inviting deterioration of a quality of an image and waste of the toner.
After completion of the transfer process, residual toner, which has remained on the photoconductive surface of the photoconductor drum 11 without being transferred, is removed by a cleaning brush or a cleaning blade of the cleaner 17, so that the photoconductive surface is in cleaned. Since the cleaner 17 is contact with the photoconductive surface, it has a strong effect on the span of life of the photoconductor drum 11.
Generally, the fuser 16 employs a pressure roll fixing scheme, and comprises a roller self containing a heater subjected to a Teflon coating process, a pressure roller consisting of a silicone rubber, a guide for preventing a paper after fixing from being rolled by the heater roller, and so on.
The span of life of the fuser 16 is shortened by an injury to the Teflon coating owing to such an involvement that the fused toner penetrates between the heater roller and the guide, or exhaustion of the Teflon coating and the silicone rubber owing to the friction at a paper running.
Thus, the amount of consumed toner, the span of life of the photoconductor drum 11 and the span of life of the fuser 16 are determined in accordance with the number of rotations in each of which a series of processes are carried out. Consequently, it is necessary to reduce the useless operations as much as possible.
FIG. 10 shows a schematic representation of the conventional image forming apparatus. In the figure, a printing apparatus 1 includes in control unit 2 an external connection interface 3 constructed with a Centronics Interface and so on. Printing data from a terminal unit 9 are entered through the external connection interface 3.
The control unit 2 is provided with, in addition to the external connection interface 3, a receiving buffer 4, a microprocessor 5, a font memory 6, an image memory 7 and a printer interface 8.
The control unit 2 is connected through the printer interface 8 to a printer unit 10. The printer unit 10 is provided with, as stated above, the photoconductor drum 11 having a photoconductive surface on an outer periphery thereof, the electrostatic charger 12 for uniformly charging the photoconductor drum 11, the light emitting diode array (exposure) 13 for forming an electrostatic latent image corresponding to image data on the photoconductive surface, the developing unit 14 for providing electrostatic adhesion of a toner to the electrostatic latent image, the transfer unit 15 for transferring a toner image to a printing paper, the fuser 16 for heating and fusing the transferred toner image to penetrate through fibers of the printing paper, and a cleaner 17 for removing residual electrostatic charge and toner on the photoconductive surface.
Further, the printer unit 10 is provided with a printing paper feeding unit 18 for automatically feeding a fixed type of printing paper, a hopping roller 19 for supplying the printing paper from the printing paper feeding unit 18, a hopping roller clutch 20, a paper feed sensor 22 for sensing the printing paper supplied from the printing paper feeding unit 18, a registering roller 23 for transporting the printing paper, a delivery roller 25 for delivering the printed printing paper to a delivery unit 27, a paper output sensor 24 for sensing delivery of the printing paper, a main drive motor 21, which may be a stepping motor, for paper feed, paper transfer, driving of the photoconductor drum 11 and so on, power transmission means 30 such as a transmission gear and a transmission belt for power transmission, and printing mechanism control 26 for controlling the whole mechanism of printer unit 10 and performing communication with the control unit 2.
The control unit 2 and printer unit 10 are connected through a serial interface 28 for performing communication therebetween and a video interface 29 for transferring and controlling printing data formed with dot image data.
In the printing apparatus 1, when the printing data is entered from a host computer, not shown, through the terminal unit 9 and the external connection interface unit 3, the data is taken in the receiving buffer 4.
Next, microprocessor 5 reads character codes included in the printing data, and generates dot image data for printing referring to the font memory 6.
The dot image data for printing is edited, for example, as dot image data for printing corresponding to a page of printing paper, and then written into the image memory 7.
In case of transmission of the image data from the host computer, not shown, a dot image developing processing is performed at the host computer side. Thus, not only does it take time until a transmission starts, but the data transmission takes time, since the image data is of a large capacity. However, in this case, it is sufficient for the microprocessor 5 to write the received image data into a predetermined address of the image memory 7 as it is.
On the other hand, in case of a business graph printing and so on, data are transmits from the host computer in form of a graphic command. Thus, the microprocessor 5 performs an editing operation for the data and then writes the edited data into a predetermined address of the image memory 7. In this case, the microprocessor 5 performs a bit map developing processing, and thus it takes much time to write a page of dot image data into the image memory 7.
Thus, when the dot image data for printing has been completed, a printing paper is transferred from the printing paper feeding unit 18 toward the the transfer unit 15. During transfer of the printing paper, the dot image data for printing drives the light emitting diode array 13 to form the latent image on the outer periphery of the photoconductor drum 11. When the photoconductor drum 11 rotated in the direction of arrow 111, the latent image is developed by the developing unit 14 and the developed image is transferred to the printing paper in the transfer unit 15. The printing paper is fixed by the fuser 16 and then discharged toward the carrying out unit 27. Thus, printed on the printing paper is information based on printing data received from the host computer.
Next, the conventional image forming apparatus will be explained more in detail, referring to FIGS. 11-14, hereinafter.
FIG. 11 shows an operational flow of a control unit of the conventional image forming apparatus. FIG. 12 is an operational flow chart of a printing unit of the conventional image forming apparatus. FIG. 13 is a time chart of the conventional image forming apparatus, and FIG. 14 is a diagram used for the explanation of the printing unit of the conventional image forming apparatus.
Now referring to FIG. 11, in steps S1 and S2, first, upon receipt of printing data transmitted from the host computer, the control unit 2 performs a page of receiving processing. In steps S3 and S4, an editing processing is performed to form a page of dot image data. In steps S6-S7, a paper feed ready signal, which is transmitted from the printer unit 10 through the serial interface 28, is discriminated, and if possible, a print start command is transmitted through the serial interface 28 in a timing shown in FIG. 13(c) to start a real printing processing.
Next, referring to FIG. 12A, in steps S10-S12, the printing mechanism control 26 determines, upon receipt of the print start command, as to whether the printer unit 10 is in condition of a rest, and if in the rest condition, there starts a printing preliminary operation for performing a real printing operation. In the printing preliminary operation. the main drive motor 21 turns on, and the photoconductor drum 11, the registering roller 23, the fuser 16 and the delivery roller 25 are driven by coupling means such as power transmission means 30, for example, a transmission gear and belt, for power transmission (refer to FIG. 14A). Thus, there are provided the preliminary operations such as a primary charge on the photoconductor drum 11, a toner charge by toner agitating in the developing unit 14, and providing a constant fusing temperature. Such a preliminary operation is carried out during (time TR) one to two revolutions of the photoconductor drum 11.
In step S13, the printing mechanism control 26 turns on the hopping roller clutch 20 and connects the power of the main drive motor 21 to the hopping roller 19 so as to start taking out of the printing paper 31 from the printing paper feeding unit 18 (refer to FIG. 14B).
In step S14, the printing paper 31 taken out from the printing paper feeding unit 18 runs on a paper carrying path, the paper feed sensor 22 informs the printing mechanism control 26 of a paper feed sensor turn-on signal at the time (time TH) when the paper feed sensor 22 detects the paper presence (refer to FIG. 14C).
In steps S15-S16, when the printing mechanism control 26 recognizes the fact that the printing paper 31 is detected by the paper feed sensor 22 and be transferred by the registering roller 23, the hopping roller clutch 20 is turned on to provide conditions for allowance of a real printing.
In step S17, at the time point (time TW) when a latent image is formed by the light emitting diode array 13, a toner image is formed by the developing unit 14, and there is provided such a relation that a distance that a distance l1 until the portion of the surface of photoconductor drum 11, on which the toner image is formed, reaches the transfer unit 15 for transferring the toner image to the printing paper, equals a remaining carrying distance l1 for the printing paper until it reaches the transfer unit 15. The printing mechanism control 26 starts a real printing processing to request the control unit 2 to send the dot image data for printing through the video interface 29 (refer to FIG. 14D). When the real printing processing starts, the dot image data for printing is transmitted from the control unit through the video interface 29 and the light emitting diode array 13 is driven, so that the latent image is formed on the outer periphery of the photoconductor drum 11. The photoconductor drum 11 rotates in direction of arrow 111 in synchronism with the paper transfer, the latent image is developed by the developing unit 14 to form the toner image, and the toner image is transferred to the printing paper 31 in the transfer unit 15 (refer to FIG. 14E).
In steps S18-S20, while a series of operations from the latent image formation to the transfer are sequentially performed, the printing mechanism control 26 monitors a running condition of the printing paper 31 and informs the control unit 2 of a next page feed ready signal through the serial interface 28, upon detection of turn on of the paper output sensor 24 and turn off of the paper feed sensor 22 (refer to FIG. 14F).
In steps S21-S22, when the printing mechanism control 26 detects turn on of the paper output sensor 24, the control unit 2 transmits a printing start command for a next page to the printing mechanism control 26 through the serial interface 28, if an editing processing for the next page printing data has been completed.
In steps S23-S24, the printing mechanism control 26 starts a next page paper feed processing, upon receipt of the printing start command for the next page, and transmits a paper feed ready signal off to the control unit 2.
In a case where no printing data for a next page exists in the control unit 2, or in a case where the editing processing has not completed in the control unit 2, there is provided a discharge waiting condition for the printing paper in course of the real printing processing. When the transfer of the processed page has been completed (refer to FIG. 14G), and the printing paper is moved for distance 12 from the transfer unit 15, in other word, the photoconductor drum 11 moves for distance 12 from the transfer unit 15 to the cleaner 17, residual electrostatic charge and toner on a surface of the photoconductor drum 11 are removed by the cleaner 17, and the cleaning processing for the page is terminated (refer to FIG. 14H). The printing paper 31 after transfer is fixed by the fuser 16 (refer to FIG. 14I). When the page has passed through the paper output sensor 24 (refer to FIG. 14I), the printing mechanism control 26 detects turn off of the paper output sensor 24 in step S21 and turns off the main drive motor 21 in step S25 so as to terminate the real printing processing. During a period of time until the main drive motor 21 is turned off, the photoconductor drum 11, the developing unit 14, the registering roller 23, the fuser 16 and the delivery roller 25, which are coupled with the main drive motor 21 through the belt, gear and so on, continue to be driven.
In the image forming apparatus arranged as stated above, however, the printing paper feeding unit 18, the photoconductor drum 11, the developing unit 14, the registering roller 23, the delivery roller 25 and so on are driven by a single power source, and thus those elements are simultaneously driving-started and driving-stopped. That is, according to the conventional image forming apparatus as stated above, it would be impossible to perform, only at the necessary time, the charging for the photoconductor drum 11, the charging for the toner within the developing unit 14, the developing operation, the cleaning operation, and the fixing operation.
It is necessary for the photoconductor drum 11 and the developing unit 14 to provide time TR needed for a preliminary operation (performed only when one page printing), printing paper transfer time TW until start of print data writing, printing paper transfer time T11 from a point of time of writing of the printing data until the transfer, and printing paper passage time TP, but unnecessary to provide the other times such as printing paper feeding time TH and discharge time (given by subtraction of cleaning time from TS). Reversely, it is unnecessary for the fuser 16 to provide those times TR, TH, TW and T11. Particularly, in case of one page printing/one job, or in a case where receiving processing and editing processing times are long, needless operation would be performed.
Further, in a case where there is provided a long distance for the printing paper transfer from the printing paper feeding unit 18 to the photoconductor drum 11 as an image forming section, or in a case where there is provided a long distance for the printing paper transfer from the photoconductor drum 11 or the fuser 16 to the discharge section, and so on, life of the photoconductor drum 11 and the fuser 16 would be shortened, and further increases the amount of consumed toner.

Image forming apparatus having photoconductor drum and fuser independently operable in timing


A processor performs layout analysis, and classifies pieces of bitmap data into a character area and a picture area. The processor divides each of the character area and the picture area into a plurality of tiles having a predetermined shape, thereby creating a table including information representing either character attribute or picture attribute in association with each tile number. The processor performs scalar quantization for data of each tile using a quantization coefficient for characters or pictures, based on the created table. The processor encodes the data of each tile using an SNR progressive technique or a resolution progressive technique, and performs post quantization for the data using a quantization parameter for characters or pictures. Then, the processor stores the encoded data into a storage device.

1. Field of the Invention
The present invention relates to an image encoder, an image encoding method, a recording medium and a computer data signal embodied in a carrier wave, for encoding electronic documents in consideration of the human recognition characteristics, thereby processing the electronic documents to be easily recognized by users and to be rapidly displayed.
2. Description of the Related Art
Recently, for the sake of conservation of natural resources or for the sake of cost reduction in office, paperless processing using IT (Information Technology) is becoming popular in companies, etc. As one paperless method, there is a technique for transforming paper documents into electronic documents. An image encoder (information encoder) reads out and digitizes information of characters or figures printed on a paper document by using a scanner, and stores the read and digitized information in an internal hard disk, etc. A user specifies an electronic document stored in the image encoder and displays the specified document on a display, so that the user can view the same information as that printed on the paper document.
The image encoder generally includes a search function for searching for a predetermined electronic document from a mass of electronic documents stored therein. To effectively use the search function, a keyword for search is attached to the electronic document. Upon reception of a search instruction together with the keyword input through the keyboard, etc., the image encoder begins searching a target electronic document.
To enhance the storage performance or transmission performance of the electronic documents, the image encoder reduces the amount of data to be encoded when transforming the paper documents into electronic documents.
The image encoder may transmit and display an electronic document using a progressive technique. According to a progressive technique, a low-quality image, whose resolution, gradation and frequency bandwidth are not initially in a sufficient level, is transmitted and displayed. Subsequently, additional information is transmitted piece by piece to gradually improve the quality of the image, and then the image with the best quality can be transmitted and displayed.
If an electronic document is transmitted using a progressive technique, a terminal which is connected to the image encoder displays a poor-quality image, and displays the image which will gradually be improved in its quality. In the end, the terminal can displays the best-quality image.
However, as compared to paper documents, the above-described image encoder (electronic documents) can not easily be handled by the users. Hence, the image encoder can not widely be spread, so that the paperless processing can not widely and efficiently be performed.
In the case where the electronic document is stored in the image encoder, the user needs to affix a reference keyword (for search) to the document. The user may feel trouble to set a certain keyword, or may have some difficulty with it. In the case where an unsuitable keyword is attached to the electronic document, this document can not be searched out. For example, if a keyword of "good-looking cloth" which is a user's subjective and personal expression is attached to a predetermined electronic document, this electronic document can not searched out based on any of ordinary keywords,
Usually, when people have the newspaper or magazine in their hand, they do not read only a target article in the newspaper or magazines. First, people briefly read the newspaper, find out an interesting article in the newspaper or magazines, and read the detail of, the article afterwards.
This reading manner can not be accepted for the image encoder. In the image likewise the case of paper documents. However, according to conventional image encoders, transmission or displaying of data requires a long period of time, so that users can not just freely read the plural document pages.

Image encoder, image encoding method, recording medium and computer data signal embodied in a carrier wave


An iterative process is used to set the phase prechirp of a WDM optical transport system to a system's optimal level that maximizes the signal quality. A signal degradation factor takes into account linear and non-linear effects along the optical path and is used as a receive end feedback signal to control the phase prechirp level at the transmitter site. By using the FEC corrected errors rate as the feedback signal, optimization of signal quality is performed even when the system is running error free. By using an adaptive phase prechirp transmitter, signal degradation compensation can be also performed on a per wavelength basis to compensate for the residual dispersion slope and to allow optimization of individual channels independently of the net link dispersion value.

The invention relates generally to optical transport systems and more particularly to an optical fiber transmission system with an adaptive phase prechirp transmitter.
Optical networks are presently the physical medium of choice and maximizing their performance is a constant need. The universal access to communications created by the introduction of Internet has driven the demand for more high-bandwidth networks capable of handling large volumes of data at high speed and low latency.
A Composite Signal Degradation Factor
For transmitting data over an optical network, the information is encoded into a series of pulses, or bits. As the signal propagates over the physical fiber, degradations of the signal tend to accumulate with distance and can make a pulse unrecognizable above the ambient noise level in the optical channel. Such degradations in signal quality can cause bits to be misinterpreted at the receiving end, thereby increasing the bit error rate (BER).
Signal degradation is due to factors like dispersion, chirped lasers, chirped external modulators, just to enumerate a few. Dispersion, or pulse broadening, is the main contributor to signal degradation. By broadening the pulses, this phenomenon causes inter symbol interference (ISI) where widened pulses encroach on time slots of neighbouring pulses.
The phenomenon of group velocity dispersion (GVD), e.g. chromatic dispersion (CD) and polarization mode dispersion (PMD), as well as fiber non-linearities, e.g. the self-phase modulation (SPM), are significant obstacles to achieving quality communication standards over longer repeaterless transmission distances.
Dispersion causes pulse broadening due to the fact that different optical wavelengths travel at different speeds within a fiber depending on the fiber parameters. Chromatic dispersion (CD) is a signal degradation effect which increases linearly with the length of the optical path. Chromatic dispersion (CD) can be also viewed as variations in the propagation constant of the fiber in respect to the frequency.
With the advent of optical amplification, modern transport networks generally operate in the 1,540 nm window of silica fiber, while the low-dispersion window is at 1,310 nm. However, most of optical fiber transmission lines presently laid are 1,310 nm, low-dispersion, single mode fibers (SMF). The effect of dispersion can be reduced if special fibers with minimal dispersion characteristics shifted from the 1,310 nm window to 1,540 nm window are employed. Such fibers are referred to as dispersion shifted fibers (DSF). However, even for DSF, the accumulated dispersion across the wavelength band at 1,000 km reach is far beyond a 10 Gbps receiver dispersion tolerance.
PMD causes pulse broadening because the two orthogonal polarization modes of the light travel at different speeds along a fiber. This is mainly due to the ellipticity of the fiber core. In addition, the distribution of signal energy over the different states of polarization (SOP) changes with time, due to changes in ambient conditions, e.g. temperature changes, and thus the PMD penalty varies with time as well. For example, the differential time delay between the two orthogonal SOPs on a link is usually between 0.5 and 2.0 ps/√km, and may vary over the bandwidth of a source.
The optical signal is also degraded by the Kerr effect which is a non-linear effect of the optical transmission medium, representing the increase of the index of refraction of the fiber with the intensity (I) of the optical signal. The changes of this index modulate the phase of the optical signal passing through the fiber and thus, re-distributes the signal frequency spectrum. Self-phase modulation (SPM) is characteristic for systems where the optical signal modulates itself, and the resulting changes in frequency distribution are translated into amplitude modulation due to fiber dispersion.
The interplay between CD and non-linearities such as SPM, can lead to increased distortion as a function of transmission distance. The combined GVD-SPM effect for waveform degradation may be expressed as:DB2PavL2=constant,  EQ1where D is the dispersion (ps/nm/km);B is the bit transmission rate (bps);Pav is the average optical power (mW) in the transmission line; andL is the transmission distance.
For example, if the transmission rate is increased from 10 Gbps to 40 Gbps, Pav has to be increased 4-times, resulting in a reduction of the transmission distance of 1/64 L for the same allowable dispersion (D).
It is known that some isotropic materials when they are under stress, e.g. mechanical forces, thermal forces, electrical fields, become anisotropic and may change the index of refraction in certain directions within the fiber material. Dispersion-compensating elements (DCE) having a negative induced dispersion coefficient, are typically introduced in the path of light to create negative dispersion to counteract the positive dispersion experienced in signal propagation through optical fibers.
A Dispersion Compensation technique usually implies use of successive lengths of fiber with positive and negative alternating dispersions, or dispersion slopes [S=dD/dλ) ], for controlling the dispersion phenomenon over a long span. The single mode (SM) optical fiber causes positive dispersion (D) at a rate of +17 pico seconds per kilometer per wavelength of light, or D=17 ps/(nm-km). If a SM fiber is alternated along a span with dispersion compensating fiber (DCF), having a negative dispersion value larger than the dispersion of the SM fiber, a small net link dispersion may be obtained for the entire connection. For example, fiber spans with high negative dispersion D=−68 ps/(nm-km) used in coils of ¼ L, are sufficient to compensate conventional SM fiber and to cause "back-to-zero", or dispersion equalization.
Large negative dispersion may be also introduced using chirped fiber Bragg gratings, Mach-Zender interferometers (MZI), Gires-Tournois interferometers (GTI), etc.
To maintain quality communications with higher bit rate signals, the optical signal-to-noise ratio (OSNR) must increase to overcome the effect of the ISI. Such increase in OSNR is often obtained by increasing the transmit power and is accounted as the "power penalty". The group velocity dispersion (GVD) limits the permissible link length (L) for a given power penalty. Moreover, when increasing the optical power, the self-phase modulation (SPM) effect increases as well.
Other non-linear phenomena in fiber are due to photons interaction with atoms which may result in atoms being excited to higher energy levels. When excited, atoms are not stable and tend to return to lower energy levels by releasing photons. These released photons propagate at a velocity that depends on their energy [W=f(λ)] and therefore, their wavelength is different from that of the originating photon.
The Chirp Parameter
As an almost monochromatic light-pulse travels trough a fiber, its amplitude variations cause phase changes (ΔΦ) and spectral broadening. The phase changes (ΔΦ) depend on wavelength and the modulation technique used. For a LiNbO3 laser the phase variation is given, according to the equation:
                    ΔΦ        =                  C          ·                      π            2                    ·                                    V              0                                      V              π                                                  EQ2      where is the modulation voltage, is the voltage for full modulation [(0,1)] or Mach Zehnder, and "C" is the chirp parameter [−1<C <+1]. These phase changes are equivalent to frequency modulation, or "chirping". Significant spectral broadening, or pulse form degradation, is observed when ΔΦ≧2.
The emergency of the ultra long haul (ULH) optical transport networks where optical signals travel long distances without regeneration, places new demands on the dispersion-limited distances. The configuration of the paths and the evolution of the network may cause existing DCEs to be inadequate, and not easy to allocate along the optical path. In addition, the existing adaptive DCEs have a slow response to a rapidly changing network.
A significant factor in the cost associated with optical transport systems is the number of regenerators (OEO) required along a given communications link within the network. It is important to increase the distance between such regenerators and to reduce their number along a given communication link. The distance between regenerators is at least in part governed by the degradation of the signal along the optical path, and such signal degradation is reflected by the Bit Error Rate (BER) value, which is the ratio between the number of erroneous bits counted at the receiver (Rx) site over the total number of received bits, over a given period of time.
In addition, known dispersion compensation techniques operate "broadband" over a set of wavelengths. Broadband dispersion compensators, in general, do not equalize the dispersion at every wavelength, therefore impacting transmission performance, particularly at the edges of the wavelength transmission window. This is mainly due to the fact that these broadband compensators do not compensate precisely for dispersion slope (SO).
There is a need for a mechanism for dynamically compensating/eliminating signal degradations in the received signal for performing channel optimization in order to achieve higher bit rates and longer transmission spans.

Method of adaptive signal degradation compensation

Abstract: This method provides more flexibility when using optical switching in core networks, as it allows path optimization to new physical link connectivity, without requiring any change to the optical components such that, significant signal degradation tuning range for a WDM optical transport system is provided.


An enzyme electrode having an electroconductive base member, an oxidoreductase and an electron mediator has at least a portion (a) in which the oxidoreductase is immobilized on the electroconductive base member, and a portion (b) in which the electron mediator is immobilized on the electroconductive base member but the oxidoreductase is not immobilized on the electroconductive base member. A bio fuel cell having the enzyme electrode as at least one of an anode and a cathode allows optimization of a reaction condition of each one of a plurality of reaction steps, including an “enzymatic reaction”, an “electron transfer reaction”, etc. Thus, the bio fuel cell provides high output.

1. Field of the Invention
The invention relates to an enzyme electrode, and to a bio fuel cell that employs an enzyme electrode as at least one of the anode electrode and the cathode electrode.
2. Description of the Related Art
Recently, interest in fuel cells as a countermeasure to environmental issues and natural resource issues is increasing. A fuel cell converts chemical energy directly into electric energy by supplying a fuel and an oxidant to two electrically connected electrodes so that the fuel is electrochemically oxidized. The fuel cell, which electrochemically extracts energy, is not subject to the restrictions of the Carnot cycle, in contrast to thermal electric power generation, and therefore exhibits high energy conversion efficiency. Conventional fuel cells include solid polymer electrolyte fuel cells (PEFC), alkaline electrolyte fuel cells (AFC), phosphoric acid fuel cells (PAFC), etc. Such fuel cells often use platinum (Pt) as a catalyst. However, platinum is very costly, which is an impediment to its widespread use in fuel cells.
Recently, a bio fuel cell is drawing attention as a type of fuel cell that does not use platinum as a catalyst. The bio fuel cell is a fuel cell to which a metabolic mechanism of living organisms is applied. An example of the construction of the bio fuel cell is as follows. First, an oxidoreductase, that is, an oxidation-reduction enzyme, is immobilized on the anode electrode. In order to obtain high output, the bio fuel cell system often contains a coenzyme that is needed for the enzymatic reaction of the oxidoreductase and an electron mediator that receives electrons produced by the enzymatic reaction and transfers the electrons to the electrode. Then, the fuel cell extracts electrons and protons (H+) from a fuel, such as glucose or the like, through the enzymatic reaction. The extracted protons move to the cathode electrode via a proton conductor. In the cathode electrode, protons, electrons and oxygen that is taken in from the atmosphere or the like react to produce water.
With regard to the bio fuel cell as described above, various studies are being conducted in order to increase the power output. For example, Japanese Patent Application Publication No. 2009-140760 (JP-A-2009-140760) describes a fuel cell that includes an anode electrode on which an enzyme, a coenzyme and an electron mediator are immobilized, wherein at least one of the coenzyme and the electron mediator is also added in a fuel solution. Published Japanese Translation of PCT Application No. 2009-515302 (JP-A-2009-515302) describes a fuel cell in which a hydrophobic denatured polysaccharide that is permeable to fuel and an electron mediator is used as a substance for immobilizing an enzyme to the anode electrode.
However, the power output of conventional bio fuel cells is still unsatisfactory. A conceivable reason for this is that in the bio fuel cells, extraction of energy requires a plurality of reaction steps, including an "enzymatic reaction", an "electron transfer reaction", etc. The factors involved in these reactions include not only the oxidoreductase but also the coenzyme and the electron mediator, and some of the conditions suitable for the different reaction steps. Thus, optimization for each reaction is difficult.

Enzyme electrode, and bio fuel cell equipped therewith


A data transmission system and a data transmission method are disclosed. The data transmission system includes a cloud server, an edge computing device, and a gateway. The cloud server includes a schema database which stores a transmission address corresponding to a target schema. The edge computing device transmits a data receiving request message related to the target schema to the cloud server. The cloud server transmits the transmission address to the edge computing device after receiving the data receiving request message. After receiving the transmission address, the edge computing device receives at least one data value corresponding to at least one label of the target schema from the gateway according to the transmission address, and generates a target data corresponding to the target schema according to the at least one label and the at least one data value.

In the operation of the existing industrial Internet of Things, a gateway may receive production data provided by a machine tool equipment in the industrial field or sensing data provided by a sensor installed in the industrial field, and normalize these data to generate normalized data in a specific format. Then, the gateway uploads the normalized data directly or indirectly to the edge computing device or the cloud server through the Internet for subsequent application by the edge computing device or the cloud server.
However, the industrial Internet of Things involves large scale of data. When the gateway executes the data format normalization procedure, it serializes the data into specific formats (e.g., JSON format and XML format), embeds the data in the schema, and then performs data transmission. Because the storage space occupied by the schema is often higher than that occupied by the data, a large amount of network bandwidth will be consumed and the cost for data transmission will be too high, which will easily affect the operation of gateways, edge computing devices and cloud servers in the industrial Internet of Things. Accordingly, an urgent need exists in the art to reduce the consumption of bandwidth for data transmission and reduce the cost for data transmission in the industrial Internet of Things.

Data transmission system and data transmission method


A thermal cycling method and device is disclosed. The device comprises a sample chamber whose temperature can be rapidly and accurately modulated over a range of temperatures needed to carry out a number of biological procedures, such a DNA polymerase chain reaction. Biological samples are placed in glass micro capillary tubes and then located inside the sample chamber. A programmable controller regulates the temperature of the sample inside the sample chamber. Once a heating cycle is completed, the controller opens a door to the chamber for venting hot air out and cool ambient air is moved in. Temperature versus time profiles corresponding to optimum denaturation, annealing and elongation temperatures for amplification of DNA are achieved by the present invention.

1. The Field of the Invention
This invention relates generally to apparatus for rapid control of the temperature of a liquid sample. More specifically, the present invention relates to thermal cycling apparatus for precisely controlling and rapidly varying the temperature of a sample repeatedly through a predetermined temperatures cycle.
2. The Background Art
In numerous areas of industry, technology, and research there is a need to reliably and reproducibly subject relatively small samples to thermal cycling. The need to subject a sample to repeated thermal cycles is particularly acute in biotechnology applications. In the biotechnology field, it is often desirable to repeatedly heat and cool small samples of materials over a short period of time. One such biological process that is regularly carried out is cyclic DNA amplification.
Cyclic DNA amplification, using thermostable DNA polymerase, allows automated amplification of primer specific DNA, widely known as the "polymerase chain reaction." Automation of this process requires controlled and precise thermal cycling of reaction mixtures usually contained in a plurality of containers. In the past, the container of preference has been a standard, plastic microfuge tube.
Commercial programmable metal heat blocks have been used in the past to effect the temperature cycling of samples in microfuge tubes through the desired temperature versus time profile. However, the inability to quickly and accurately adjust the temperature of the heat blocks through a large temperature range over a short time period, has rendered the use of heat block type devices undesirable as a heat control system when carrying out the polymerase chain reaction.
Moreover, the microfuge tubes which are generally used have disadvantages. The material of the microfuge tubes, their wall thickness, and the geometry of microfuge tubes is a hinderance to rapid heating and cooling of the sample contained therein. The plastic material and the thickness of the wall of microfuge tubes act as an insulator between the sample contained therein and the surrounding medium thus hindering transfer of thermal energy. Also, the geometry of the microfuge tube presents a small surface area to whatever medium is being used to transfer thermal energy. The continued use of microfuge tubes in the art, with their suboptimal geometry, indicates the benefits of improved thermal transfer (which come by increasing the surface area of a sample container for a sample of constant volume) has heretofore not been recognized.
Furthermore, devices using water baths with fluidic switching, (or mechanical transfer) have also been used as a thermal cycler for the polymerase chain reaction. Although water baths have been used in cycling a polymerase chain reaction mixture through a desired temperature versus time profile necessary for the reaction to take place, the high thermal mass of the water (and the low thermal conductivity of plastic microfuge tubes), has been significantly limiting as far as performance of the apparatus and the yields of the reactions are concerned.
Devices using water baths are limited in their performance. This is because the water's thermal mass significantly restricts the maximum temperature versus time gradient which can be achieved thereby. Also, the water bath apparatus has been found to be very cumbersome due to the size and number of water carrying hoses and external temperature controlling devices for the water. Further, the need for excessive periodic maintenance and inspection of the water fittings for purposes of detecting leaks in a water bath apparatus is tedious and time consuming. Finally, it is difficult with the water bath apparatus to control the temperature in the sample tubes with the desired accuracy.
U.S. Pat. No. 3,616,264 to Ray shows a thermal forced air apparatus for cycling air to heat or cool biological samples to a constant temperature. Although the Ray device is somewhat effective in maintaining a constant temperature within an air chamber, it does not address the need for rapidly adjusting the temperature in a cyclical manner according to a temperature versus time profile such as is required for biological procedures such as the polymerase chain reaction.
U.S. Pat. No. 4,420,679 to Howe and U.S. Pat. No. 4,286,456 to Sisti et al. both disclose gas chromatograhic ovens. The devices disclosed in the Howe and Sisti et al. patents are suited for carrying out gas chromatography procedures but do not provide thermal cycling which is substantially any more rapid than that provided by any of the earlier described devices. Rapid thermal cycling, while potentially useful for many procedures, is particularly advantageous for carrying out the polymerase chain reaction. Devices such as those described in the Howe and Sisti et al. patents are not suitable for efficiently and rapidly carrying out such reactions.

Method for rapid thermal cycling of biological samples


Batch mixing takes place in the gap (3) between grooved faces of counter-rotating discs (1,2) such that the spiral grooves (8) and lands (10) of each face traverse the grooves (8) and lands (10) of the other, to shear and split material drawn inwardly along the grooves (8) for distributive mixing. Modifications include plural-turn spiral, straight, and truncated spiral grooving (FIGS. 5 to 10), and batch mixing in which only one disc (28) rotates (FIG. 11). Continuous mixing involving shear is carried out within a cylindrical barrel (40 FIG. 12;57 FIG. 13) between its internal helical-grooving (43;590 and the helical grooving (44;60), of opposite hand, of a rotor (41;58). The shearing can produce mechanochemical reactions that break down the molecular structure of the material, notably in the context of mastication and solubilising of used rubber in reclaim from vehicle-tyres.

The invention is especially concerned with heavy-duty mixers and heavy-duty mixing methods that are capable of use where, for example, the resultant mix has a viscosity of some 3,000 poise (300 N/m.sup.2) or more. Such mixers and mixing methods are applicable, for example, in the mastication and blending of rubbers, in the mixing of rubbers with carbon black and other ingredients for vulcanisation, in incorporating plasticisers and other chemicals into polyvinyl chloride, and in mixing fillers into polyethylene and polystyrene. The known mixers and mixing methods used for such applications have practical shortcomings, and in this regard it is an object of the present invention to provide improved forms of mixer and mixing method.


A vehicle control and computation system interfaces a task controller in the vehicle with a vehicle-specific computation manager in a cloud network. A wireless data channel couples the task controller and the cloud network. The task controller performs operational tasks in the vehicle using data-related resources in the cloud network. Upon initiating one of the operational tasks, the task controller sends a handshake signal to the computation manager as a resource request. The computation manager calls at least one cloud-based agent from a database of predetermined agents in response to the handshake signal. The task controller completes the operational task via communication with the called agent.

The present invention relates in general to automotive applications using cloud computing, and, more specifically, to the interface between a vehicle and cloud computing resources.
Onboard vehicle computing devices (e.g., microprocessor-controlled electronic modules such as powertrain controllers, driver information systems, and entertainment systems) are generally limited to relatively low processing power of vehicle computers, small data storage, and lack of easy access to programming updates or other data that is created after the vehicle is put into service. Advances in mobile connectivity between vehicles and an off-board computational cloud infrastructure are beginning to enable new classes of electronic features that are not limited in this way.
The wireless connection available for wireless vehicle communication is often characterized by variable bandwidth, variable latency, and sporadic availability. The typical in-vehicle computer or electronic control unit (ECU) is characterized by high reliability, high durability, hard real-time response, low processing power and very small memory (particularly non-volatile memory). The ECU is mobile, lasts the life of the vehicle, and is part of the vehicle purchase. Data created in the ECU tends to be related to events that have happened in the past on very short time scales. In contrast, cloud computers are characterized by high-reliability, high-computational power, large memory and (from the perspective of the vehicle) lack of real-time response. They are stationary, managed systems that are replaced frequently and operate on a lease, own, or fee-for-use basis. Data created in the cloud tends to have a forecast nature that tells what can be expected sometime into the future, rather than what has happened in the past.
While an onboard, networked control architecture remains the dominant approach for safety critical and real-time functionalities, cloud-computing applications can provide enhanced automotive control/adaptation and new functionalities. For example, cloud computing can provide resource intensive services to achieve leaner, safer, smarter, greener, and more enjoyable automotive operations.
Cloud computing is a model for enabling network access to a shared pool of configurable computing resources that have virtually unlimited storage space and essentially unlimited computational power. Areas in which cloud computing offers improved vehicle performance and driver convenience include dealing with traffic congestion, route planning, adapting target speeds to road and traffic conditions, calibrating vehicle systems (e.g., active suspension) to changing environmental conditions, and many others.
Access to cloud resources needs to be rapidly provisioned and released with minimal management effort or service provider interaction. The operational interfacing and computational management for accessing cloud resources should be optimized to the relative limitations and strengths of the two processing environments.

Vehicle-specific computation management system for cloud computing


A system is adapted to be vehicle mounted and powered by a D.C. source coupled with an inverter to cool individuals or temperature sensitive hardware under uncomfortable ambient conditions. The system includes a pumped liquid circulation loop which can be connected by self-sealing lines with cooling garments, temperature sensitive hardware and the like. An evaporative heat exchanger is provided in the loop as well as a liquid reservoir which is sized to limit short cycling of a compressor in a refrigeration loop associated therewith via the evaporative heat exchanger. A hot gas bypass can be associated with the compressor to allow recirculation of the superheated refrigerant gas when cooling is not required.

The present invention relates to an electrically-driven vapor compression system which chills a liquid circulated through a garment to provide cooling for an individual or supplied to temperature sensitive hardware devices and is operable on vehicles and other field devices where only direct current (DC) electrical power is available. The present invention also relates to an electrically-driven system which heats a circulated liquid through a garment to supply heat to the individual.
There are many ways to cool and/or heat an individual exposed to uncomfortable ambient temperatures (i.e., cold or hot temperatures). Generally, these technologies fall into the categories of passive and active systems. Passive systems include the use of phase-change materials (PCMs), which act as energy storage devices, and adsorption cooling and/or heating systems, which use the endothermic/exothermic adsorption/desorption of a gas on a chemical or physical adsorbent to supply or absorb heat from the body. Active systems include active refrigeration systems using external power to mechanically cool the individual, and active heating systems using external power to supply heat to the individual.
In the past, cooling technologies adapted for individuals have used a PCM which melts to provide a constant-temperature heat sink for absorption of body heat. A PCM can also be used for heating, in where the PCM freezes at a constant temperature, providing a constant temperature heat source for supplying heat to the body. Although this approach works quite well, the weight penalty of this technology becomes prohibitive for cooling times greater than one to two hours. After the PCM is completely melted or frozen, this process must be reversed to regenerate the PCM for another use cycle. Thus, during this regeneration process, additional PCMs must be available to continue supplying the cooling/heating requirement, or the individual must cease the activity requiring cooling or heating. Regeneration and resupply of the PCM is not always practical, especially if the individual requiring cooling/heating is in the field.
Adsorption cooling and/or heating systems can have many different configurations, but typically utilize the endothermic desorption and exothermic adsorption of a vapor on an adsorbent bed to supply the cooling or heating. These systems also have weight and/or operational drawbacks. Once the adsorbent has reached its adsorption capacity, the adsorbent must be regenerated by driving off the adsorbed vapor (typically using heat), or the adsorbent must be replaced by new adsorbent. During this time period, the required cooling or heating must be supplied by a second (dual) system, or the individual must cease the activity requiring cooling or heating. Also, a regeneration system must be available. These characteristics present a significant weight penalty problem. Also, if the adsorbent is replaced, a supply of new adsorbent must be available and the spent adsorbent must be disposed of.
Active cooling/heating systems are practical only if the individual requiring the heating or cooling has access to power, such as on a motorized vehicle. For cooling, active refrigeration using vapor-compression technology has proven to be suitable. This technology uses a refrigeration-type compressor system to provide cooling; the compressor can be powered, for example, by combustion of fuel, batteries, or tethered external power. These systems have serious drawbacks, however. Compressors driven by fuel combustion are not hermetically sealed because of the shaft seal, and will lose refrigerant from this seal. From an environmental perspective, the loss of even HFC refrigerants into the environment is becoming more unacceptable. Compressors driven by batteries typically have DC motors with brushes to power the compressor. Because the sparks from DC motor brushes can cause degradation to the refrigerant and lubricant, these DC motor compressors cannot be hermetically sealed for this purpose, but are belt-driven or otherwise drive so as to require a shaft seal that will result in refrigerant leakage and increased maintenance. Compressors driven by tethered external power severely limit the portability of the system.
Active refrigeration systems using vapor-compression technology typically condition air and supply it to the individual by cooling the air surrounding the individual. Although these systems work well, they have several drawbacks for use by individuals who require heating or cooling in conditions where heating or cooling the air is not practical. Examples are individuals working in conditions that are open to the ambient atmosphere. Obviously, heating or cooling air which is open to the ambient is not practical due to the significant loss of the energy to the ambient. Also, because the individual breathes the air, filtration is typically required to remove particles, dust, and contaminants, and in military applications, to remove chemical or biological contaminants.
Systems which cool water which is then supplied to the wearer are also known in the art. In such systems, the wearer is cooled by direct contact heat transfer with a garment (vest, pants, cap, etc.) which contains flexible plumbing lines or a bladder incorporated into the garment. A chilled liquid, typically water/antifreeze solution, is pumped through this garment and thereby cools the wearer. It is also known in the art to use thermoelectric devices to cool the liquid which is supplied to the wearer. For heating, electrical heating systems can be used to heat the air surrounding the individual or heat a liquid that is supplied to the individual. Alternatively, heat resulting directly or indirectly from fuel combustion can be used to heat the air or liquid surrounding the individual. The use of thermoelectric devices to provide cooling has several drawbacks. First, thermoelectric devices are inherently inefficient and require considerable amounts of power to provide cooling or heating. Second, the reliability and life of thermoelectric devices is a cause for concern.
It is an object of the present invention to provide an electrically-driven, portable apparatus which produces the desired cooling or heating of an individual working in uncomfortable ambient conditions with access to DC power. Cooling is accomplished using vapor compression refrigeration to cool a circulating liquid loop in thermal communication with the body. The system is operable on vehicles or other field devices where electric power is available and portability is essential. The unit is thus configured with an inverter to provide the required alternating current (AC) power to the compressor. The system can also be configured to provide heat to the body by supplying heated liquid instead of cooled liquid. The cool liquid can also be directed to cold plates to cool avionics or other temperature sensitive electronics or hardware.

Electrically-driven cooling/heating system utilizing circulated liquid


A helmet shield attaching mechanism with which when raising a shield, the shield and/or an anti-fogging auxiliary shield will not catch on a window opening rim member for a head protecting body, in spite that the operation of raising the shield in a fully-closed state is comparatively simple and that the mechanism has a comparatively simple structure. The helmet shield attaching mechanism includes a stationary base member fixing to the head protecting body, a movable base member attaching to the stationary base member so as to be movable forward and backward with respect to the stationary base member, and the shield which is pivotally supported by the movable base member. When a substantially upward force acts on the shield which is in a fully-closed state, at least one cam follower provided to the shield or stationary base member relatively follows at least one cam surface formed on the stationary base member or shield, to move the shield forward substantially to the front side.

In a full-face-type helmet or the like, an anti-fogging auxiliary shield may attach to an original shield. Such an auxiliary shield removably attaches to the inner surface of the original shield so as to form a small gap with the original shield. When using a helmet in which such an anti-fogging auxiliary shield attaches to an original shield, if the axial supports on the right and left sides of the head protecting body of the helmet merely axially support portions of the original shield near the right and left ends, the following inconveniences arise. More specifically, when pivoting the original shield upward about the axial supports on the right and left sides as the pivot center, the anti-fogging auxiliary shield may catch on a window opening rim member attaching to the window opening of the head protecting body to interfere with the original shield and anti-fogging auxiliary shield from smoothly moving upward. When raising an original shield to which no anti-fogging auxiliary shield attaches, the original shield may catch on a window opening rim member or the like more or less to interfere with the original shield from smoothly moving upward.
EP 1 293 138 A1 discloses a helmet shield attaching mechanism as described in the beginning. In the shield attaching mechanism of EP 1 293 138 A1, a fully-closed shield (that is, the original shield) is pulled forward first and is then raised. In this case, as the fully-closed shield is accommodated in a shield accommodating recess formed in a head protecting body, it can be moved upward only after pulling it forward. For this reason, in the shield attaching mechanism of EP 1 293 138 A1, as the shield is pulled forward first and is then raised, when raising the fully-closed shield, the shield can move upward without catching on a window opening rim member or the like.
In the case of the shield attaching mechanism of EP 1 293 138 A1 having the above arrangement, when raising the shield, the helmet wearer must hold the shield with his fingers, move his fingers forward to pull the shield forward, and then move his fingers upward to pull the shield upward. In contrast to this, if applying the shield attaching mechanism of EP 1 293 138 A1 to an ordinary full-face-type helmet (that is, a full-face-type helmet not having a shield accommodating recess), when raising the fully-closed shield, the helmet wearer can raise it only by holding the shield with his fingers and then moving his fingers upward. In such an ordinary full-face-type helmet, when an anti-fogging auxiliary shield attaches to the inner surface of the original shield, unless the helmet wearer performs two-step operation of pulling the shield forward and then upward, the auxiliary shield may catch on the window opening rim member. If the helmet wearer erroneously performs only one-step operation (that is, the operation of only pulling the shield upward), the original shield cannot smoothly move upward. To smoothly move the original shield upward, the two-step operation as described above is necessary, and accordingly the operation of raising the fully-closed shield becomes cumbersome.

Helmet shield attaching mechanism, and helmet attached with the same


A display system for connection to a bus in a digital processing system having a system memory. The display system comprises a display memory, a display and an interface. The display memory stores image data. The display receiving stored image data from the display memory and generates in response thereto a displayed image. The interface receiving image data and address signals from the bus, the signals corresponding to addresses in the system memory. In response to the address signals, the interface determines whether the image data relates to image data for an image stored in said display memory and in response thereto controls storage of the image data in the display memory.

Digital computers are often used to process and manipulate images. The images may be photographic, if generated externally from the computer, from, for example, a photograph. Alternatively, an image may be graphic, that is, generated entirely by the computer under control of a program or an operator. In either case, the computer may be used to modify the image, for example rotate or process the image, to enhance it or to provide additional information relating to the image to the viewer on a display screen.
A typical image comprises a plurality of picture elements, termed "pixels" or "pels," with the pixels comprising the smallest element of an image which may be processed or displayed. Each pixel is represented by a digital data word, having a selected number of bits, which represents a color or gray scale value (i.e., intensity) of the pixel. Generally, the image is stored in a video memory array of n.times.m words, where "n" and "m" identify the number of pixels in each row and column in a rectangular image. To display the image, the digital data words are sequentially read row by row from the video memory array and converted to analog form for display by the video display.
The video display generally has to be refreshed periodically, typically every one-thirtieth of a second, and so each location in the video memory array must be accessed at the same rate. The refresh is required by the video display memory hardware and cannot be interrupted without disrupting the displayed image. Problems arise if the digital image data stored in the video memory array is also used for the computations required for the processing of the image, since video memory accesses requested by the processor must be delayed if the video memory array is contemporaneously being accessed for the video display refresh. Since image processing is generally computationally intensive, such delays in servicing access requests by the processor will delay processing, potentially significantly degrading performance of the system.
Although there are display systems which include both a separate display memory which holds the image data to be displayed and an image memory which holds the image data to be processed, these systems have the disadvantage that the processed image data in the image memory must be copied into the display memory when the image data in the image memory is changed during processing. However, in this arrangement the processor may also be delayed while the image memory is being accessed to obtain image data for transfer to the display memory.


A power supply includes a control circuit that inhibits excessive input current draw during a low-line condition by decreasing a power supply output voltage in response to a measured change in either power supply input voltage or power supply input current. The power supply may be, for example, a cable television distribution network power supply that receives power from the coaxial cable that carries the television or other media signals or, in the case an optical fiber network, an auxiliary power cable associated with the fiber cable that carries the media signals.

1. Field of the Invention
This invention relates generally to power supply regulation and, more specifically, to inhibiting excessive current draw in a cable television distribution network.
2. Description of the Related Art
Cable television (cable TV or CATV) systems distribute signals from a head end to subscribers (xe2x80x9cdownstreamxe2x80x9d) through coaxial cable (xe2x80x9ccoaxxe2x80x9d), optical fiber, or a combination of coax and fiber commonly referred to as a hybrid network. Such cable network media are strung along telephone poles or through underground conduits.
Amplifiers and other devices are commonly included at intervals, which may be referred to as nodes, along the cable network. Amplifiers and similar devices commonly include active rather than passive electronics and thus require an external source of electrical power. In the case of a coax-based network, power is commonly supplied to each node through the same coax through which the radio frequency (RF) signals, e.g., television signals and digital signals, are carried. A device known as a power inserter or tap mixes power and RF signals for distribution on the coax. The voltage is typically 60 or 90 volts in U.S. cable networks. The power inserter commonly receives the power from a ferro-resonant converter, which in turn receives power from a transformer coupled to a power utility line.
At each network node at which an amplifier or other active device is located, a splitter separates the power from the RF signals. The splitter provides the power to the amplifier power supply. Power is recombined with the RF signals at the node, and the combined signal is placed on the coax for further transmission to downstream nodes. In the case of a hybrid network, the RF signals are carried on the fiber, and the power is carried on the coax; no power inserters or splitters are necessary.
Undesirable brownout or temporary low-voltage conditions may occur in a cable network. In a brownout condition, because the amplifier power supplies are constant-power devices, the dropping of the voltage carried on the coax drops causes the amplifier power supplies to draw more current. The additional current draw on the ferro-resonant converters can cause them to cease operating normally, i.e., cease resonating. Even after the voltage rises again to the normal level, a ferro-resonant converter may fail to re-start, i.e., begin resonating.
To avoid the above-described problem of the ferro-resonant converters failing to restart after a brownout, it has been suggested to include a low-voltage cut-off circuit at each node. A low-voltage cut-off circuit can disconnect an amplifier power supply from the coax when it detects a drop in the voltage below a threshold deemed to define such a brownout condition, such as 41 volts. The cut-off circuit may include hysteresis such that it does not reconnect the power supply until the voltage rises above a different threshold, such as 44 volts.
A problem with the use of low-voltage cut-off circuits is that they can cause undesirable oscillation or instability. The voltage at a node close to the head end may not drop sufficiently to cause a cut-off circuit at that node to disconnect a power supply from the coax supplying the power, but it may drop sufficiently at nodes farther downstream from the head end. As soon as the cut-off circuits at such nodes farther downstream from the head end detect a brownout and disconnect the power supplies from the coax, the voltage rises discontinuously at those disconnecting nodes as a result. The voltage rises discontinuously because no current exists in the coax downstream from the upstream-most disconnecting node. An absence of current implies a zero voltage drop across the resistance of the coax. Thus, the voltage at the disconnecting nodes instantaneously changes to the voltage at the upstream-most node that did not disconnect. Because this voltage is insufficient to cause the cut-off circuit at that node to disconnect, it may be similarly sufficient (i.e., but for hysteresis) to cause the cut-off circuits at nodes farther downstream to reconnect. But because the voltage at the reconnected nodes is still below the cut-off threshold, those nodes again disconnect. This disconnecting and reconnecting of cut-off circuits continues to occur in an oscillatory manner.
It would be desirable to provide a power supply circuit that does not cause oscillation in the event of a brownout condition and that does not hamper the operation of ferro-resonant converters. The present invention addresses these problems in the manner described below.
The present invention relates to power supply regulation and inhibiting excessive current draw by decreasing a power supply output voltage in response to a measured change in a parameter of the power supply input signal. The parameter can be either power supply input voltage or, alternatively, power supply input current. The power supply can be, for example, a cable television distribution network power supply that receives power from the coaxial cable that carries the television or other media signals or, in the case an optical fiber network, an auxiliary power cable associated with the fiber cable that carries the media signals.

Method and architecture for limiting input current to a broadband network power supply


The disclosed embodiments enable service policies to be provisioned for a Mobile Node dynamically. A network device receives a message including at least one of one or more attributes of a Mobile IP session and one or more user preferences associated with the Mobile Node. One or more rules to be applied to the Mobile Node may then be identified. One or more of the identified rules are executed according to at least one of one or more of the attributes of the Mobile IP session and one or more of the user preferences associated with the Mobile Node.

The present invention relates to Mobile IP network technology. More particularly, the present invention relates to dynamically provisioning and providing service control policies to a Mobile Node in a Mobile IP environment.
Mobile IP is a protocol which allows laptop computers or other mobile computer units (referred to as "Mobile Nodes" herein) to roam between various sub-networks at various locations—while maintaining internet and/or WAN connectivity. Without Mobile IP or a related protocol, a Mobile Node would be unable to stay connected while roaming through various sub-networks. This is because the IP address required for any node to communicate over the internet is location specific. Each IP address has a field that specifies the particular sub-network on which the node resides. If a user desires to take a computer which is normally attached to one sub-network and roam with it so that it passes through different sub-networks, it cannot use its home base IP address. As a result, a business person traveling across the country cannot merely roam with his or her computer across geographically disparate network segments or wireless nodes while remaining connected over the internet. This is not an acceptable state-of-affairs in the age of portable computational devices.
To address this problem, the Mobile IP protocol has been developed and implemented. An implementation of Mobile IP is described in RFC 3344 of the Network Working Group, C. Perkins, Ed., "IP Mobility Support for IPv4," August 2002. Mobile IP is also described in the text "Mobile IP Unplugged" by J. Solomon, Prentice Hall. Both of these references are incorporated herein by reference in their entireties and for all purposes.
The Mobile IP process in a Mobile IPv4 environment are illustrated in FIG. 1. As shown there, a Mobile IP environment 2 includes the internet (or a WAN) 4 over which a Mobile Node 6 can communicate remotely via mediation by a Home Agent 8 and may also include a Foreign Agent 10. In a Third Generation Partnership Project 2 (3GPP2)/CDMA2000 network, the Foreign Agent is implemented in what is generally referred to as a Packet Data Serving Node (PDSN). In the absence of a Foreign Agent in a Mobile IPv4 environment, or in a Mobile IPv6 environment in which a Foreign Agent is not implemented, the Mobile Node 6 can obtain a topologically correct IP address (i.e., collocated IP address) and register this IP address with the Home Agent. (In a Mobile IPv6 environment, this is accomplished via an Access Router rather than a Foreign Agent.) Typically, the Home Agent and Foreign Agent are routers or other network connection devices performing appropriate Mobile IP functions as implemented by software, hardware, and/or firmware. A particular Mobile Node (e.g., a laptop computer) plugged into its home network segment connects with the internet through its designated Home Agent. When the Mobile Node roams, it communicates via the internet through an available Foreign Agent. Presumably, there are many Foreign Agents available at geographically disparate locations to allow wide spread internet connection via the Mobile IP protocol. Note that it is also possible for the Mobile Node to register directly with its Home Agent.
As shown in FIG. 1, Mobile Node 6 normally resides on (or is "based at") a network segment 12 which allows its network entities to communicate over the internet 4 through Home Agent 8 (an appropriately configured router denoted R2). Note that Home Agent 8 need not directly connect to the internet. For example, as shown in FIG. 1, it may be connected through another router (a router R1 in this case). Router R1 may, in turn, connect one or more other routers (e.g., a router R3) with the internet.
Now, suppose that Mobile Node 6 is removed from its home base network segment 12 and roams to a remote network segment 14. Network segment 14 may include various other nodes such as a PC 16. The nodes on network segment 14 communicate with the internet through a router which doubles as Foreign Agent 10. Mobile Node 6 may identify Foreign Agent 10 through various solicitations and advertisements which form part of the Mobile IP protocol. When Mobile Node 6 engages with network segment 14, Foreign Agent 10 relays a registration request to Home Agent 8 (as indicated by the dotted line "Registration"). The Home and Foreign Agents may then negotiate the conditions of the Mobile Node's attachment to Foreign Agent 10. For example, the attachment may be limited to a period of time, such as two hours. When the negotiation is successfully completed, Home Agent 8 updates an internal "mobility binding table" which specifies the care-of address (e.g., a collocated care-of address or the Foreign Agent's IP address) in association with the identity of Mobile Node 6. Further, the Foreign Agent 10 updates an internal "visitor table" which specifies the Mobile Node address, Home Agent address, etc. In effect, the Mobile Node's home base IP address (associated with segment 12) has been shifted to the Foreign Agent's IP address (associated with segment 14).
Now, suppose that Mobile Node 6 wishes to send a message to a Correspondent Node 18 from its new location. In Mobile IPv4, a message from the Mobile Node is then packetized and forwarded through Foreign Agent 10 over the internet 4 and to Correspondent Node 18 (as indicated by the dotted line "packet from MN") according to a standard internet protocol. If Correspondent Node 18 wishes to send a message to Mobile Node—whether in reply to a message from the Mobile Node or for any other reason—it addresses that message to the IP address of Mobile Node 6 on sub-network 12. The packets of that message are then forwarded over the internet 4 and to router R1 and ultimately to Home Agent 8 as indicated by the dotted line ("packet to MN(1)"). From its mobility binding table, Home Agent 8 recognizes that Mobile Node 6 is no longer attached to network segment 12. It then encapsulates the packets from Correspondent Node 18 (which are addressed to Mobile Node 6 on network segment 12) according to a Mobile IP protocol and forwards these encapsulated packets to a "care of" address for Mobile Node 6 as shown by the dotted line ("packet to MN(2)"). The care-of address may be, for example, the IP address of Foreign Agent 10. Foreign Agent 10 then strips the encapsulation and forwards the message to Mobile Node 6 on sub-network 14. The packet forwarding mechanism implemented by the Home and Foreign Agents is often referred to as "tunneling." In the absence of a Foreign Agent, packets are tunneled directly to the Mobile Node 6 collocated care-of address.
Access Control Lists (ACLs) are often used to control the flow of packets from a particular source and/or addressed to a particular destination. These lists typically include a source address and/or a destination address, and an action to be taken for packets transmitted via the source address and/or addressed to the destination address. In order to implement such ACLs, they must be statically configured on the desired network device. While ACLs are commonly used in a network environment such as a LAN or WAN, conditions change continuously in a mobile environment.
In view of the above, it would be beneficial if a mechanism could be applied that considers the changing conditions that occur in a Mobile IP environment.

Attribute driven mobile service control logic


The present invention provides a method of fabricating a semiconductor substrate and a method of fabricating a light emitting device. The method includes forming a first semiconductor layer on a substrate, forming a metallic material layer on the first semiconductor layer, forming a second semiconductor layer on the first semiconductor layer and the metallic material layer, wherein a void is formed in a first portion of the first semiconductor layer under the metallic material layer during formation of the second semiconductor layer, and separating the substrate from the second semiconductor layer by etching at least a second portion of the first semiconductor layer using a chemical solution.

1. Field of the Invention
The present invention relates to a method of fabricating a semiconductor substrate and a method of fabricating a light emitting device. More particularly, the present invention relates to a method of fabricating a semiconductor substrate and a method of fabricating a light emitting device based on separating a growth substrate.
2. Discussion of the Background
Light emitting diodes (LEDs) that have a gallium nitride (GaN) based semiconductor may be used for various applications, such as traffic signals, backlights in liquid crystal panels, and the like. It is known that luminous efficiency of an LED is influenced by the dislocation density of crystals and crystal defects. GaN-based semiconductor crystals may be grown on a heterogeneous substrate, such as sapphire or the like. However, lattice mismatch or a difference of thermal expansion coefficients may occur between a GaN layer and a substrate, which may result in a high dislocation density or an increase in defects.
The GaN-based semiconductor crystals may be grown on a homogeneous substrate, such as a GaN substrate and the like. However, it may be difficult to form a GaN melt and to fabricate a GaN substrate due to a high dissociation rate of nitrogen in GaN, and the like. A GaN bulk crystal grown for a GaN substrate may be separated by mechanical grinding or laser ablation. However, it may be difficult to produce a GaN substrate of a practical size using these methods. Particularly, the laser ablation method may require a considerable amount of time to perform, which may increase the cost of a GaN substrate.
GaN crystal growth is shown and described in "Polycrystalline GaN for light emitter and field electron emitter applications," by S. Hasegawa, S. Nishida, T. Yamashita, H. Asahi, (Thin Solid Films 487 (2005), pp 260-267) (hereinafter, "Hasegawa, et al."), which is hereby incorporated by reference in its entirety for all purposes as if fully set forth herein. In Hasegawa, et al., GaN crystals are grown on quartz substrates, high-melting-point metal substrates of Tungsten (W), Molybdenum (Mo), Tantalum (Ta) and Niobium (Nb), and Silicon (Si) substrates using plasma assisted molecular beam epitaxy, respectively.
Since it may be difficult and costly to fabricate the GaN substrate, semiconductor devices such as LEDs or laser diodes are generally manufactured by growing a GaN layer on a heterogeneous substrate such as sapphire and the like. However, as mentioned above, the high dislocation density or the increase in defect density may degrade the luminous efficiency of the LED. In addition, the sapphire substrate has a lower thermal conductivity than the GaN substrate, and may cause deterioration in heat dissipation properties of a device. Thus, use of a sapphire substrate for LEDs or laser diodes may limit operational lifespan thereof.
To solve such problems of the sapphire substrate, a laser lift-off process has been developed in which a secondary substrate is attached to a GaN layer after the GaN layer is grown on a heterogeneous substrate as a growth substrate. The secondary substrate in turn is locally decomposed from an interface between the sapphire substrate and the GaN layer by an excimer laser to remove the sapphire substrate. This process is used to fabricate a vertical-type light emitting device suitable for large size LEDs (i.e., a power chip) and the like.
As described above, however, separation of the growth substrate using the laser may require an extended processing time, thereby causing an increase in manufacturing costs of the light emitting device. Further, since it may be necessary to increase transmittance of the sapphire substrate to laser beams in order to radiate a laser beam through the sapphire substrate, it may be necessary to polish an exposed surface of the sapphire substrate, which may decrease a thickness of the sapphire substrate.

Method of fabricating semiconductor substrate and method of fabricating light emitting device


A method for producing silicon using microwave and a microwave reduction furnace for use therewith are disclosed, with which it is possible to quickly reduce silica to quickly produce silicon. A material of a mixture of a silica powder and a graphite powder of a mixture of a silica powder, a silicon carbide powder and a graphite powder is set in a refractory chamber. Then, the material set in the chamber is irradiated with microwave. The graphite powder absorbs a microwave energy to increase the temperature, after which silica and graphite react with each other to further increase the temperature while producing silicon carbide, and the heated silica and silicon carbide react with each other. SiO produced through this reaction and silicon carbide are allowed to react with each other, thereby producing high-purity silicon.

High-purity silicon is used in semiconductor substrates and solar cells. As a method for producing such high-purity silicon, silica is melted in an arc furnace to obtain impurity-rich coarse silicon, after which the coarse silicon is hydrogenated into a silane (SiHCl3) gas, which is reduced with hydrogen to obtain high-purity silicon. A problem with this conventional method is that the process is complicated, failing to allow for quick production of high-purity silicon. In order to melt silica by an arc furnace, it is necessary to heat the material to 3000° C. by arcing, thereby requiring a high input energy for heating, resulting in a high production cost.
On the other hand, another method has been proposed in the art, in which a carbon source is used to reduce silicon oxide which has been purified through acid precipitation from an aqueous solution of silicon oxide dissolved in aqueous phase with an acidifying agent, thereby obtaining solar grade silicon, as described in Patent Document No. 1 (claim 1 of Patent Document No. 1). Patent Document No. 1 discloses that this reduction of purified silicon oxide into silicon is done in an arc furnace, a thermal reactor, an induction furnace, a rotary kiln and/or a microwave heating furnace (claim 7 of Patent Document No. 1).
Patent Document No. 2 discloses a method for producing silicon from silicon oxide through thermal reduction in a microwave oven. This conventional technique is a method in which silicon oxide is used as a starting material, and the obtained silicon is additionally subjected to a zone melting method in a microwave oven.    Patent Document No. 1: Japanese National Phase PCT Laid-Open Publication No. 2012-504100    Patent Document No. 2: Japanese National Phase PCT Laid-Open Publication No. 2011-500495

Method for producing silicon using microwave, and microwave reduction furnace


The present invention relates to a multipurpose sensor system for vehicles to detect unattended children and/or pets in a locked vehicle. The multipurpose sensor system includes a sensor unit having a plurality of sensors disposed inside the vehicle, and solar panels disposed on an exterior surface of the vehicle. The sensors detect the vehicle's interior temperature and a child's and/or pet's body temperature. More specifically, when the temperature inside the vehicle is equal to or greater than a threshold value, an alarm/alert is generated by the sensor system. The alert is transmitted to an electronic device of a driver, parent or caretaker. Further, an alert is also transmitted to an emergency service for rescuing the child and/or pet.

By way of background, many vehicles include a front seat belt-monitoring system that outputs a warning or alert signal if the driver-side seatbelt and/or the front passenger-side seatbelt is unbuckled. Further, a rear seatbelt monitoring system outputs a warning if one of the rear seatbelts is unbuckled. These sensors typically include a presence detection component that determines whether a person is sitting in the seat before checking a seat belt status.
In many jurisdictions within the United States of America, infants and children of a certain age and weight are required to be strapped into a child's car seat or booster seat positioned in the rear seats when the automobile is in motion. Child seat-monitoring systems for these child car seats and booster seats detect whether the child car seat or booster seat is installed in the vehicle according to pre-existing installation guidelines and also monitors a seatbelt buckle status and other conditions of the child car seat or booster seat. However, these existing monitoring systems are used for monitoring the child car seat or booster seat when the ignition of the vehicle is on and when the vehicle is in motion.
When a vehicle owner intentionally or unintentionally leaves a child in a locked vehicle for an extended period of time, the unattended child can be seriously injured due to the rising temperature inside the vehicle. Similarly, pets are usually taken along by pet owners while travelling to places. However, pet owners may often leave their pets inside the vehicle knowingly or unknowingly for extended periods of time. Pets left unattended in the vehicle can experience discomfort and/or injury.
Thus, if pets and/or children remain inside a closed and locked vehicle for an extended period of time, especially during extremely hot or extremely cold weather conditions, the vehicle may get hot or cold enough inside to cause the pets and/or children to be injured.
No matter how careful or responsible a parent, vehicle owner or pet owner may be, accidents can still happen, and a child and/or pet can accidentally be left behind in a vehicle. A child and/or pet could suffer serious injury, or even death, if left unattended in a vehicle for an extended period of time. Without an alert system, children and/or pets may be forgotten in hot cars for a longer duration, which is dangerous for infants, children and/or pets. It is desired to have a system that can warn the parent and/or emergency services to rescue the locked child and/or pet and can also perform immediate in-vehicle remedial actions to help the pet and/or child.
Therefore, there exists a long felt need in the art for a child/pet occupancy warning system that detects the presence of an infant, child or pet left unattended inside a locked vehicle. There is also a long felt need in the art for a child/pet occupancy warning system that monitors if a pet and/or child is left inside the locked vehicle, and alerts the vehicle owner to take action to rescue the unattended pet and/or child. Additionally, there is a long felt need in the art for a child/pet occupancy warning system that ensures that the child and/or pet is not left unattended in a vehicle for an extended period of time. Moreover, there is a long felt need in the art for a child/pet occupancy warning system that can alert emergency services to rescue the child and/or pet. Further, there is a long felt need in the art for a child/pet occupancy warning system that prevents the child and/or pet from suffering from heatstroke, suffocation, serious injuries and even death. Furthermore, there is a long felt need in the art for a child/pet occupancy warning system that can perform in-vehicle remedial actions. Finally, there is a long felt need in the art for a child/pet occupancy warning system that prevents the child and/or pet from being left inside the vehicle for an extended time period, and ensures that the vehicle owner take immediate rescue measures to protect the child and/or pet from being suffocated inside the vehicle.
The subject matter disclosed and claimed herein, in one embodiment thereof, comprises a multipurpose sensor system for detecting a child and/or pet in a vehicle. The multipurpose sensor system comprises a sensor unit that has a plurality of sensors, and a solar panel disposed on an exterior surface of the vehicle for providing power to the sensor unit. The plurality of sensors include a thermal sensor for detecting temperature inside the vehicle and body temperature of a child and/or pet in the vehicle and a location sensor for determining location of the vehicle. The sensor unit is connected to an electric control unit of the vehicle for activating one or more in-vehicle remedial actions, including rolling down windows, activating air conditioning or activating the heating unit of the vehicle. The sensor unit comprises a wireless communication module for transmitting an alert to a companion smartphone application indicating a locked child and/or pet when the temperature detected by the thermal sensor is greater than a predetermined threshold.
In this manner, the novel multipurpose sensor device of the present invention accomplishes all of the forgoing objectives, and provides a relatively safe, easy and convenient solution to determining the presence of a child and/or pet left inside a locked vehicle and ensures that the child and/or pet does not remain unattended in the vehicle for an extended period of time. Additionally, the multipurpose sensor device is powered by solar power, and is configured to send alerts to the vehicle owner or other concerned person when a child and/or pet is left inside the vehicle, allowing them to take immediate actions to rescue the child and/or pet and prevent injury.

Multipurpose sensor system for detecting children and pets in a locked vehicle and alerting a caregiver and emergency services


The present disclosure relates to a display resource scheduling method and device for an embedded system, a computer readable storage medium and an electronic device. The embodiment of the present disclosure provides a display resource scheduling method for an embedded system, at least a host operating system and a first guest operating system running on the embedded system, and the embedded system including a graphics processing unit and a display-specific hardware accelerator. The method includes: receiving a graphic to be displayed of the first guest operating system; preferentially scheduling the display-specific hardware accelerator to perform a display operation on the graphic to be displayed; if resources of the display-specific hardware accelerator are exhausted, scheduling the graphics processing unit to perform a display operation on the graphic to be displayed.

At least one host operating system and at least one guest operating system can be running simultaneously on an embedded system. Sequentially to enable the guest operating system to implement the display function on the embedded system, the implementation method in the related art is as follows.
A native window (which can be abbreviated as NW) is requested in the host operating system. This requested native window is used as an output window of the guest operating system, that is, pixels used by the guest operating system for displaying are all displayed on the native window. If the host operating system provides a graphics processing unit (GPU), the guest operating system simulates a hardware graphics accelerator by emulating a graphics processing unit in an emulator and providing a Graphics Library supporting the graphics processing unit in its user space, to accelerate the speed of the graphics processing in the guest operating system. Or the guest operating system provides a simulated virtual Graphics Library in its user space, and the simulated virtual Graphics Library completes the procedure of the graphic process by invoking the actual Graphics Library in the host operating system. The display pixels of the guest operating system processed by the virtual Graphics Library are finally displayed in this native window that is requested by the guest operating system in the host operating system.
The technical problems existing in the above related technology are:
The guest operating system emulates the graphics processing unit in the emulator or the guest operating system provides a simulated virtual Graphics Library in its user space, wherein the emulated graphics processing unit or the simulated virtual Graphics Library both completes the procedure of the graphic process by invoking the actual Graphics Library in the host operating system. The actual Graphics Library of the host operating system completes the procedure of the graphic process in accordance with the user's programming, based on the graphics processing unit (GPU) in the embedded system
With the development of technology, users have been expecting mobile devices or smart terminals (such as smart phones, tablets, etc.) that are lighter, thinner and have longer standby time. However, in the existing embedded system, all the graphic displays and processes of the guest operating system are performed by using the graphics processing unit, which results in the problems of not making full use of the display resources of the embedded system, higher energy consumption of the embedded system and slower graphic process speed, etc.
Therefore, there are still rooms for improvement in the related art.
It should be noted that, the information disclosed in the above Background section is only for better understanding of the background of the present disclosure, and thus may include information that does not constitute the prior art known to those of ordinarily skilled in the art.

Display resource scheduling method and device for embedded system

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