An STP link selection system includes a designated switch device that receives a first communication that indicates that a first link provided to a non-designated switch device from a first port is available and, in response, automatically assigns the first port with a primary port priority. The designated switch device then subsequently receives a second communication that indicates that a second link provided to the non-designated switch device via a second port is available and, in response, the second port is automatically assigned with a secondary port priority. The designated switch device identifies a first port identifier that is based on the primary port priority to the non-designated switch device and, based on the first port identifier relative to a second port identifier that is based on the secondary port priority, the non-root switch device transmits communications via the first link and blocks communications via the second link.

The present disclosure relates generally to information handling systems, and more particularly to selecting Spanning Tree Protocol (STP) links for communication between information handling systems.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems such as, for example, switch devices, sometime utilize the Spanning Tree Protocol (STP) for transmitting traffic through a network. As would be understood by one of skill in the art, the STP is a network protocol that builds a loop-free logical topology for Ethernet/Layer 2 (L2) networks, and operates to prevent bridge loops and the broadcast radiation that results from them, while allowing a network design that includes backup links that provide fault tolerance if an active link fails. The STP may be utilized to create a spanning tree within a network of connected layer-2 bridges (e.g., the switch devices discussed above), and disables those links that are not part of the spanning tree, leaving a single active link between any two network nodes. The active link provided between any two switch devices may be provided by a "designated port" on a "root/designated switch device" and a "root port" on a "non-root/non-designated switch device" (also referred to a "root-designated pair"), while the non-active links may be provided by a "designated port" on that root/designated switch device and an "alternate port" on that non-root/non-designated switch device (also referred to a "alternate-designated pair"). In many examples, one of the switch devices is selected as a root/designated switch device based on its root bridge identifier being lower than any of the other switch devices, and the active link for each non-root/non-designated switch device may be selected amongst a plurality of different links available between the directly connected root switch device or designated switch device and that non-root/non-designated switch device first based on relative root path costs, then based on the lowest designated bridge identifiers if the root path costs associated with the links are the same, and then based on the lowest designated port identifiers if the designated bridge identifiers associated with the links are the same. The use of the designated port identifier in selecting the active link can raise a number of issues.
Typically, the selection of a port on a non-root/non-designated switch device as a root port is based on that port receiving the lowest designated port identifier from the directly connected root/designated switch device (relative to the other ports that are included on the non-root/non-designated switch device and that provide a link to the directly connected root/designated switch device), while the remaining links provided by those other ports are considered non-active links (i.e., links that are blocked from forwarding data traffic). However, subsequent to this STP active link selection, if a port provides a new link to the directly connected root/designated switch device that becomes available and receives a lower designated port identifier from the root/designated switch device, the active link selection process is repeated so that the new link may be selected as the active link (i.e., due to it having received the lowest designated port identifier from the directly connected root/designated switch device.) As such, each time a new port on the directly connected root/designated switch device having a lower port identifier (i.e., relative to the port on the root/designated switch device that is currently providing the active link) has its associated link become available, the STP triggers a topology-change event and traffic is forced to reconverge on that new link due to its selection as the new active link. Similarly, in links between root/designated switch devices and non-root/non-designated switch devices provided in Link Aggregation Groups (LAGs), when a first port channel that provides a first LAG that is provided on the root/designated switch device is selected as the active LAG, and a second port channel that provides a second LAG that is provided on the root/designated switch device and that includes a lower port channel identifier than that of the first port channel becomes available at a later time, the active LAG selection process will be repeated to select that second LAG as the active LAG, which interrupts traffic that was being transmitted over the first LAG.
The repeating of the STP active link selection process/reconvergence operations is associated with considerable overhead, including the performance of STP port re-selection operations, hardware port state re-programming, Media Access Control (MAC) address flushing, MAC address re-learning, and/or other STP tasks known in the art. Furthermore, as discussed above, the STP active link selection process/reconvergence operations can also result in traffic disruptions that can lead to data loss. Conventional solutions to these issues may be realized via a feature in the STP that allows a network administrator or other user to manually configure port priorities of port (or port channel priorities of port channels) in order to override the selection of the active link (or active LAG) via the port identifiers and port channel identifiers discussed above. However, such processes are time consuming, and in relatively large switch device/network deployments with relatively large numbers of links or LAGs, the time and effort needed to assign port priorities to each port (or port channel priorities to port channels) in the switch devices/network is considerable. Furthermore, even with manual port priority configuration, the issues associated with ports/links (or port channels/LAGs) becoming available at a later time (i.e., after the active link or active LAG has been selected) remains, and in LAG situations it is often not possible to determine the order in which different LAGs will become available. As such, manual port priority configuration does not resolve the potential of traffic disruptions and/or data losses that can occur due to the repeating of the STP active link selection process/reconvergence operations discussed above.
Accordingly, it would be desirable to provide an improved STP link selection system.

Spanning tree protocol port-based link selection system


The present invention provides a triple-mode antibody display system that simultaneously matures, displays and secretes an antibody to a target of interest. An antibody in vivo-matured and complexed with membrane anchored bait can be expressed on the surface of the host cell, while complexed with a soluble bait the antibody is secreted from the host cell. Methods of using the system for identifying binders that bind specifically to an antigen of interest are also provided. Polypeptides, polynucleotides and host cells useful for making the protein binder display system are also provided along with methods of use thereof.

Antibodies have been widely accepted for treatment of a variety of diseases, including cancer, arthritis and infectious diseases. Currently more than 300 monoclonal antibody-based drugs are in clinical trials. The predominant advantage of antibody-mediated therapy is its high specificity, facilitated by direct binding to the target(s) for neutralization or elimination (KRAEBER-BODERE et al. 2014). As of Nov. 10, 2014, forty-seven monoclonal antibody products have been approved for medical use in the US or Europe (ECKER et al. 2015). Nevertheless development of antibodies as research reagents, diagnostics and therapeutics with high affinity and specificity remains both time-consuming and labor-intensive. Accordingly an animal-free, high throughput platform for antibody discovery and isolation would accelerate the antibody generation process.
Success in generation of highly specific antibodies in such an ex vivo system depends on the ability to establish highly diverse heavy and/or light chain libraries together with efficient screening capacity e.g., antibody clone identification, validation and antibody production.
One example of a widely used ex vivo system is phage display, in which an antibody fragment (e.g. ScFv) is expressed as a polypeptide fusion to a bacteriophage coat protein and subsequently an antibody of interest is selected by binding to immobilized biotinylated antigen.
As phage display is based on a bacterial protein expression system, it has several shortcomings. For example, some eukaryotic proteins may fold poorly in bacteria, or may require additional post-translational modifications, such as efficient formation of inter- and intra-chain disulfide bonds, which are unavailable in bacterial cells.
In a yeast surface display system, an antibody or antibody fragment (e.g. ScFv, VH, Fab or IgG) is expressed as a polypeptide fusion to a cell membrane anchor protein and subsequently an antibody of interest is selected by binding to immobilized biotinylated antigen in biological panning or by Fluorescence-Activation Cell Sorting or FACS.
In one example of a yeast surface display system, an antibody fragment is fused with yeast 87 amino acid AGA2 membrane protein (Uniprot number P32781, SEQ ID NO:1). Secreted antibody-AGA2 polypeptides are retained on the cell surface thanks to heterodimerization of AGA2 with the yeast membrane anchor protein AGA1 (Uniprot number P32323, SEQ ID NO:2).
To address the lack of protein secretion in eukaryotic display systems, several dual-mode display and secretion systems have been developed, in which cells can produce antibodies that are simultaneously displayed on the cell surface and secreted into the media. The secretion-and-capture system couples antibodies to the host cell surface, e.g., by biotin, where in vivo biotinylated protein of interest is captured onto the avidinated surface of the parent cell (RAKESTRAW et al. 2011). As secreted biotinylated antibodies can bind non-selectively to all avidinated cells, this system exhibits a high incidence of cross-contamination between antibody clones. Similar cross-contamination problems are observed in other systems where the full length secreted antibody is tethered on the host cell surface by binding an immunoglobulin binding protein (RHIEL et al. 2014 and U.S. Pat. No. 9,260,712) that is fused to a cell surface anchor protein.
A dual-mode surface, Fc-bait full antibody display system (SHAHEEN et al. 2013 and U.S. Pat. No. 9,365,846) addresses the cross-contamination problem. In this system, host cells will produce both full IgG antibody and antibody Fc fragment fused with a cell membrane anchor. The latter serves as a bait to capture monovalent antibody fragments. Bivalent IgG antibodies are secreted. As the yeast endoplasmic reticulum (ER), is not equipped for efficient and large scale folding of complex proteins, such as full length human antibodies (DE RUIJTER et al. 2016) the yield of secreted antibody is very low.
Application of the dual-mode surface, Fc-bait full antibody display system to mammalian cell surface display will address the full IgG secretion efficiency issues. Mammalian cell surface systems, however, have several shortcomings, including the cost, experimental time related to mammalian cell cultures as well as the level of antibody library diversity.
Thus, there is a need for an antibody generation system that provides high diversity of antibody repertoire, efficient display of antibodies on the cell surface and an option to secrete antibodies into the media, and that will therefore significantly increase the speed, reduce the cost and improve success of the antibody generation process.
Success in generation of highly specific antibodies in an ex vivo system depends on the ability to establish highly diverse heavy and/or light chain libraries together with efficient screening capacity. Currently ex vivo non-mammalian approaches for generating antibodies such as phage display (HAWKINS et al. 1992), yeast surface display (BODER and WITTRUP 1997; BODER and WITTRUP 2000), ribosome display (HANES and PLUCKTHUN 1997; HE and TAUSSIG 1997), RNA display (REIRSEN et al. 2005), and mammalian cell display (BEERLI et al. 2008) are not intrinsically capable of affinity maturation because they lack the capacity to effect somatic hypermutation. Alternatively, error-prone-PCR followed by labor-intensive sub-library re-cloning steps are generally incorporated into all current ex vivo systems to generate high-affinity antibodies (CHAO et al. 2006 and U.S. Pat. No. 8,691,730). This method is easily doable if the antibody is expressed by a single gene such as in the single-chain variable fragment (scFv) format. When antibodies consist of separate light and heavy chain genes, error-prone PCR sub-libraries have to be constructed for each antigen-specific clone to maintain the correct heavy-light chain pairing. Otherwise random pairing of a light chain from one active antibody with a heavy chain from a different clone will not likely generate again a target-specific antibody.
There is a continuing need in the art for improving the generation of specific antibodies. This invention is to a novel technology platform that combines antibody maturation, cell surface antibody display, and antibody secretion in one system. The invented system can be used for polypeptide library diversification, protein maturation and screening of binder proteins with modified affinity to another molecule. Advantages of this invention include a low cost, rapid growth eukaryotic protein expression and a surface display system with ease of culture and culture maintenance, facile manipulation and genetic engineering. Moreover, yeast mating allows random combination of antibody heavy chain and light chain libraries to form a combined library with highly diverse random H/L combinations, as is known in the art.
In an embodiment of the invention, the expression of lamprey CDA1 (Uniprot number A5H718, SEQ ID NO:3)—the most powerful deaminase mutator of DNA in yeast—which can be in combination with the chemical supermutagen HAP—allows rapid library diversification. In an embodiment of the invention, the expression of any deaminase mutator allows rapid library diversification.
In an embodiment of the invention, an antibody in vivo matured and complexed with membrane anchored bait can be expressed on the surface of the host cell, and/or while instead complexed with a soluble bait the matured antibody can be secreted from the host cell providing effective means for antibody maturation and identification.
In an embodiment of the invention, the use of diploid and/or polyploid yeast strains versus the normally used haploid yeast version protects yeast cells from lethal mutation damage due to the presence of two or more copies of essential genes. With selection methods, such as biological panning, Fluorescence Assisted Cell Sorting (FACS) for cell sorting or ELISA for secreted active antibody validation, yeast cells expressing functional binders can be quickly identified and isolated. Such methods can be used in combination.

Triple-mode system for antibody maturation, surface display and secretion


A device for the delayed disconnection or switching-off of the drive of cutting mechanisms of paper shredders, wherein the switching-on process of the cutting mechanisms is automatically triggered predominantly by the insertion of the materials to be shredded into the feed shaft. At least one of the gear stages between the drive motor and the pair of cutting rollers is provided with a spiral or helical gear unit, wherein at least one of the gear wheels of the gear unit is mounted so as to be axially movable in the direction of its axis, and wherein a switching element or limit switch connected to the motor control is arranged in the range of the axial distance of movement of the at least one gear wheel.

1. Field of the Invention
The present invention relates to a device for the delayed disconnection or switching-off of the drive of cutting mechanisms of paper shredders, wherein the switching-on process of the cutting mechanisms is automatically triggered predominantly by the insertion of the materials to be shredded into the feed shaft.
2. Description of the Related Art
In cutting mechanisms of paper shredders, the delayed disconnection of the drive has the purpose of ensuring that the drive always stops only after the cutting mechanism has been cleared or cleaned, i.e., the paper particles, dust resulting from cutting, etc., have left the cutting mechanism, and primarily of ensuring that the respective document has been completely destroyed or shredded.
In order to achieve this, electronically acting components have already become known in actual practice which are provided for the drive control. However, these components have the specific disadvantage that they are relatively expensive.
Also known in the art are pneumatic devices which operate with an air cylinder and delay valve. In addition to the disadvantage of a hard switching-on process, this type of construction also has the specific disadvantage that it is relatively expensive and that the many fine mechanical structural elements are susceptible to trouble. In addition, the electronic and pneumatic delay elements which have thus far become known in the art have the principal disadvantage that the duration of the after-running time of the cutting mechanism must be preadjusted empirically; however, since it is generally known that depending on the type of paper, the "self-cleaning" time of the cutting mechanisms varies widely and takes particularly long in the case of very thin paper, the systems which have become known in the art always constitute a compromise solution which is not very effective.

Device for the delayed drive disconnection of cutting mechanisms of paper shredders


Provided are a light dimming method for alleviating inter-frame flicker and dimming device. The light dimming method includes that: an average luminance value Avgdata when a sender sends physical frames is calculated; whether inter-frame flicker is generated when the sender sends data or not is judged according to a ratio of Avgdata to an average luminance value Avglight in an illumination state; and if the inter-frame flicker is generated when the sender sends the data, the sender inserts a dimming frame in an idle pattern, wherein the dimming frame is used for compensating for a luminance difference between Avgdata and Avglight. A value of a duty cycle of the physical frame sent to regulate the luminance of the light source in the idle pattern of the sender is within a certain range, and is not required to be accurately equal to a duty cycle of a line coding method adopted for a physical layer.

A VLC technology refers to a technology for short-distance light wireless communication with an optical medium which is visible for human eyes and has a wavelength ranged from 400 nm to 700 nm. The VLC technology has the advantages of being resistance to electromagnetic interference, having no interference related to a Radio Frequency (RF) system, and being capable of adopting an unlicensed spectrum. When visible light is adopted for data transmission, a visible light source (such as a light-emitting diode) may be rapidly turned on and turned off or luminance of the visible light source may be modulated at a sender; and at a receiver, a modulated light signal is converted into data which may be processed by the receiver after being received.
When visible light is adopted for communication, it is necessary to ensure that there is no influence on normal use of a user over illumination equipment at the same time of implementing data transmission. Thus, the following two problems are required to be considered: the first is to realize a data transmission function; and the second is to avoid the problem of inter-frame flicker during transmission of a data frame. The problem of inter-frame flicker is caused by a difference between average luminance of a light source during data sending and average luminance in an illumination state (that is, a sender is in a receiving state or an idle illumination state).
According to a method for alleviating inter-frame flicker in a related technology, a sender in an idle/receiving state adopts an idle pattern, namely independently sending a frame used for regulating luminance of a light source. Such a method has a requirement on accurate calculation for making a duty cycle of the frame used for regulating the luminance of the light source the same as a duty cycle of a line coding scheme adopted by a physical layer. Therefore, average luminance values of the frame used for regulating the luminance of the light source and a data frame are equal.

Light dimming method and device for alleviating inter-frame flicker


A test pattern generating unit generates a test pattern in which unconverted data is arranged such that same values of 0 or 1 bits in converted data according to a code conversion table are successively transferred to each of a plurality of serial transfer channels that a high-speed serial transfer device has. A basic pattern setting unit sets a basic pattern while considering a byte order method and an RD value of code conversion in the high-speed serial transfer device. A basic pattern resetting unit resets the basic pattern in accordance with a channel usage method of a bit transfer order in the high-speed serial transfer device. A basic pattern rearranging unit performs rearrangement such that the basic pattern is transferred to each of the channels in accordance with the number of used channels and a channel usage method such as bit transfer order in the high-speed serial transfer device.

1. Field of the Invention
The present invention relates to high-speed serial transfer device test method, program, and device which examine mis-synchronization failure of a high-speed serial transfer device; and particularly, relates to high-speed serial transfer device test method, program, and device which generate a test pattern in which same values are continued in serial transfer data which has undergone code conversion from the test pattern and successively transfer the data.
2. Description of the Related Arts
Conventionally, in a high-speed data transmission system such as Ethernet (R), gigabit-order high-speed data transfer is realized by use of high-speed serial transfer devices. In systems and devices using high-speed serial transfer devices, mis-synchronization and garbled-bit failure associated with it (hereinafter, referred to as "mis-synchronization") is known to have a high percentage among device failure caused by the high-speed serial transfer devices. A PLL circuit is incorporated in the high-speed serial transfer device, and a synchronized state is maintained when the PLL circuit detects synchronization loss between received data and clock at the timing of bit change in the received data, and feeds back the synchronization loss. As described above, the timing for detecting and feeding back synchronization loss in the PLL circuit is at the timing of bit change in the received data; therefore, as long as the same values which are 0 or 1 bits are continued, the feed-back function of the PLL circuit for synchronization loss does not work. Consequently, in the high-speed serial transfer devices having low tolerance, margin, or the like with respect to frequency deviation, when the same values are continued, the data and the clock lose synchronization to an extent that signals cannot be normally reproduced, thereby causing mis-synchronization to occur. Among the high-speed serial transfer devices which have passed tests as single parts and been shipped out, some of them having low tolerance or a margin with respect to frequency deviation when mounted on a device sometimes cause mis-synchronization, etc. since noise, etc. from the entire device also affects. Therefore, tests with respect to mis-synchronization have to be effectively performed in a state in which the high-speed serial transfer device is mounted on a device or in an operating state. Conventionally, the test for examining mis-synchronization, etc. can be performed by use of a PRBS pattern (Pseudo-random Binary Sequence: pseudo-random sequential pattern) which corresponds to benchmark testing for high-speed serial transfer.    [Patent Document 1] Japanese Patent Application Laid-Open (kokai) No. 2002-084247    [Patent Document 2] Japanese Patent Application Laid-Open (kokai) No. 2002-051033    [Patent Document 3] Japanese Patent Publication (kokoku) No. H07-028211    [Patent Document 4] Title: What is a pseudorandom number sequence URL:http://infohost.nmt.edu/tcc/help/lang/fortran/pseudo.html
However, such conventional tests for examining mis-synchronization has a problem that they require a long period of time in many cases. One reason thereof is that the test is not performed by use of a pattern which is targeting on detection of mis-synchronization of the high-speed serial transfer device. Also the test using the PRBS pattern corresponding to a benchmark test for high-speed serial transfer devices cannot be considered as an effective test for mis-synchronization and the like since the pattern is not particularly specialized for detection of mis-synchronization and the like. of the high-speed serial transfer device. Therefore, when devices involving mis-synchronization of high-speed serial transfer devices pass mass-production tests and cause failure in the field even though the high-speed serial transfer devices have passed tests as single parts and been shipped out, actions such as collection, investigation, repair, and maintenance take labor hours and time, thereby providing a factor of increased cost. In the high-speed serial transfer device, for example, serial transfer is performed after the transfer data is subjected to a code conversion; and for this code conversion, two different code conversion tables of RD− conversions and RD+ conversions are provided in accordance with running disparity RD (Running Disparity) for facilitating amplification of faint signals, and whether the conversion of the subsequent data will be an RD+ conversion or an RD− conversion is controlled depending on whether the number of 0 bits and 1 bits of the preceding converted data is the same or different. Therefore, as one function test of the high-speed serial transfer device, all of the converted data stored in the code conversion tables is desired to be sequentially caused to flow through transfer channels so as to test the function of the receiving side in the field. This test can be performed, for example if it is 8-bit/10-bit conversion, by causing 256 variations of 8-bit data to be successively flowed and converted. However, the code conversions of the high-speed serial transfer device include two different conversions, that is, RD+ conversions and RD− conversions, and which conversion is to be performed depends on the RD value of the converted data immediately preceding the test pattern. This depends on the state of the device at the moment, and cannot be externally specified. Therefore, even when 256 variations of 8-bit data are caused to flow successively, all the conversions of the code conversion tables in which RD+ conversions and RD− conversions are performed cannot be performed to transfer the converted data. Thereat, there has been no other way but to repeat causing the 256 variations of 8-bit data to flow continuously so as to achieve function examination which is statistically close to that using the all the converted data; which involves problems that the examination takes time, and the converted data which is not transferred remains although the amount thereof is small. An object of the present invention is to provide high-speed serial transfer device test method, program, and device which enable examination of mis-synchronization to be performed in a short period of time by generating a test pattern specialized for examination of mis-synchronization failure in a high-speed serial transfer device and successively transferring the pattern in a target device.

High-speed serial transfer device test data storage medium and device


A control section (6) merely passes an incoming image data signal DAT onto a source driving section for display driving during the display of a still image. During the display of a moving image, the control section (6) converts, using a computing section (61) and a look-up table (5), a grayscale level signal in the incoming image data signal DAT to a grayscale level signal that is obtainable without using those application voltages at which the response speed of liquid crystal is slow. The control section (6) then outputs the resultant grayscale level signal to the source driving section for display driving.

The liquid crystal display device has a conventional, well-known problem of slow response. In the liquid crystal display device, the applied voltage to the liquid crystal layer is varied to change the alignment of liquid crystal molecules, which in turn results in a change in display pixel transmittance and hence a change in the display grayscale level. The slow response of the liquid crystal display device is caused by the liquid crystal molecules taking a prolonged period of time to completely change to a different alignment state after a change in the applied voltage to the liquid crystal layer.
Recent wide-screen and high-definition LCDs provide a very short drive period (write period) per pixel. Within the short write period, liquid crystal molecules cannot completely change their alignment in response to a change in the application voltage, and the LCD cannot achieve the desired display grayscale level.
There are approaches that are known to be capable of improving response speed. One example is overshoot driving for forceful grayscale level transition. The approach however entails angular response and other degradation in video quality and may not achieve sufficient speed. The approach also requires memory and other additional components.
To address these issues, for example, Japanese Unexamined Patent Publication (Tokukai) 2002-131721 (published May 9, 2002) discloses a method of improving the response speed by producing displays without using grayscale levels where the response speed slows down. The method is briefly explained.
The LCD's slow response problem does not occur uniformly across the whole range of grayscale levels. The response speed is extremely slow at some levels. For example, an LCD of vertical alignment (VA) in normally black mode exhibits extremely slow rising response speed when changing from a low grayscale level to a middle grayscale level, which can be a cause for after-images and other display problems.
Table 1 shows some results of measurement of the response speed of a VA module capable of producing 256 grayscale levels (0 to 255). The table shows changes of grayscale levels from one of nine levels (0, 32, 64, 96, 128, 160, 192, 224, and 255) to another of the nine levels.
TABLE 1"A": Less than 1 frame (16.67 ms)"B": 1 frame to less than 2 frames"C" 2 frames to less than 3 frames"F" 3 frames or longer
As can be seen from Table 1, the rising response speed is extremely slow, taking three or more frames to respond, when the grayscale level changes from 0 to middle level values (32, 64, 96, 128). Other entries showing an extremely slow rising response speed are mostly found where the grayscale level changes from a low value to a middle value.
Accordingly, the liquid crystal drive method of Tokukai 2002-131721 does not use those changes from low grayscale levels to middle grayscale levels where the rising response speed is slow. FIG. 4 identifies a typical range of liquid crystal driving voltage as A to B. In that convention, the range of liquid crystal driving voltage where the response speed is extremely slow is from A to C. The liquid crystal drive method of Tokukai 2002-131721 does not use the range A to C, but uses only the range C to B when driving liquid crystal. The voltage at A is not 0 volts because the response of the liquid crystal used with VA scheme is inherently slow in the absence of applied voltage.


Aspects of the disclosure are directed to sequencing. In accordance with one aspect, sequencing includes creating a one hot list; selecting a current word of the one hot list as a one hot list output; comparing the one hot list output with a current accumulation register value of an accumulation register to produce a logical comparison; inputting the logical comparison to the accumulation register to generate an updated accumulation register value; and outputting the updated accumulated register state to a client unit to enable or disable the client unit.

A sequencer is a controller to enable or disable a plurality of client units sequentially. That is, each client unit is powered up one at a time in a particular order. For example, client units may be power supplies in a system where each power supply is turned on in a power up sequence in a particular order of client unit enablement, i.e., in a permutation. Typically, the power down sequence is the inverse of the power up sequence. The power up sequence may include the transmission of an enable signal from the sequencer to each client unit and the reception of an acknowledgement (e.g. a power good signal) by the sequencer from each client unit. In addition, the power up sequence should maintain state, i.e., previously enabled client units should remain enabled as other client units are enabled in turn.
In conventional designs, the sequencer may be hard coded with specific logic to implement the power up sequence for a defined quantity of client units. Hard coding (e.g., in a programmable logic device, PLD) implies that changing the power up sequence may be difficult as the architecture changes over time. However, designs may require increased flexibility in sequencer operation by changing the permutation as client units are added, subtracted or swapped to the system. Thus, what is desired is a more generic and flexible sequencer architecture which is independent of the specific permutation desired.

Apparatus and method for a permutation sequencer


A transformer includes a first electrical conductor, a second electrical conductor and a core. The second electrical conductor is electromagnetically coupled with the first electrical conductor. The second electrical conductor includes at least one multilayer spiral coil, which is formed by winding a conductive wire and has a through hole at its central portion. Both ends of the conductive wire extend outward from a periphery of the multilayer spiral coil. The core penetrates through the through hole and covers at least one portion of the first electrical conductor and the second electrical conductor.

1. Field of Invention
The invention relates to a transformer, and, in particular, to a transformer having a high current density.
2. Related Art
A transformer is an electronic assembly, which is frequently used in various electronic apparatuses. Referring to FIG. 1, a conventional transformer 1 includes a bobbin 11, a coil set 12, a pin seat 14 and a core 15. The coil set 12 includes a primary coil and a secondary coil each formed by winding a conductive wire around a winding region 111 of the bobbin 11. The primary coil is electromagnetically coupled with the secondary coil. The pin seat 14 is connected with the bobbin 11 and includes a plurality of pins 141, which is for electrically connecting with a circuit board 17. The core 15 is composed of a first core 151 and a second core 152, which are respectively fit with two ends of the bobbin 11 and are connected together to form an electromagnetic loop.
In general, the coil set is made in the form of concentrated or folded winding. The concentrated coil set 12 is directly wound around the bobbin 11, while the folded winding structure has a primary coil and a secondary coil each wound to form a wire cake 20, as shown in FIG. 2, and then the wire cakes 20 are alternately arranged along an axial direction of the bobbin 11 and then fit with the bobbin 11. The conventional wire cake 20 is a single-layer spiral wire cake formed by spirally winding a conductive wire outward on a plane, and both ends (i.e., a beginning end 20a and a terminating end 20b) of the conductive wire are suspended outside the structure of the wire cake 20. The beginning end 20a of the conductive wire turns from inside and thus extends outside the structure of the wire cake 20 so that the beginning end 20a may be electrically connected with a pin or connected to a power source. However, under large capacity and high current requirements, the number of turns of the coil of transformer 1 is typically increased. However, the beginning end 20a of the wire has to turn outward from the inner diameter of the wire cake 20 due to the conventional winding method of the single-layer spiral wire cake. Thus, when plural wire cake structures are connected in series, a gap exists between the wire cakes due to the width of the conductive wire. The existence of the gap tends to reduce the extent of coupling between the windings.
Therefore, it is an important subject to provide a transformer having a high extent of coupling between the windings and high current density.


A quantum-confined device (100) and method for manufacture thereof. The device (100) comprises a substrate (10) having at least one protrusion (12) and a layer of a two-dimensional material (14) arranged thereupon. The layer of the two-dimensional material (14) is arranged on the substrate (10) and the at least one protrusion (12), the at least one protrusion (12) causing localised strain in the layer of the two-dimensional material (14) to form a quantum dot or a quantum wire at the region of localised strain.

Quantum confined or low-dimensional devices such as quantum dots and quantum wires are becoming increasingly important for use in potential applications in various fields. Whereas quantum dots provide quantum confinement of electrons and/or holes in all three spatial dimensions, quantum wires provide quantum confinement of electrons and/or holes in two spatial dimensions but allow electron transport in the third dimension. The unusual quantum properties exhibited by quantum dots and quantum wires make them useful candidates for incorporation into many future technologies. For instance, quantum dots may be used for many applications including light emitters and especially single photon sources. Single photon sources are expected to form an integral part of a plethora of future applications including quantum cryptography and quantum computing technologies. Quantum wires have been conjectured for use in numerous applications including transistors, integrated circuitry and charge sensing as well as quantum computing.
A number of mechanisms have been shown to produce optically active quantum dots with properties similar to natural atoms or trapped ions. Examples include self-assembled quantum dots formed by growth of epitaxial layers having a mismatched lattice constant, or atomistic defects in silicon carbide or diamond. Similarly, different techniques exist for forming quantum wires including use of naturally occurring crystals such as zinc oxide. However, each of these mechanisms face similar challenges when looking to incorporate quantum dots or quantum wires into devices for specific applications.
First, scalability remains a problem for large-scale manufacture of devices. In particular, the low yield for formation of quantum dots and quantum wires using many known techniques means that manufacturing devices on a large-scale, especially using diamond, is not yet practical. Furthermore, the position of a quantum dot or quantum wire on a substrate cannot be easily pre-determined or designed using most established methods of formation. Such a requirement will be necessary for feasible large-scale manufacturing of integrated circuits including quantum dots and quantum wires. In view of this, there is a need for quantum-confined devices such as quantum dot or quantum wire devices that can be produced on a large scale whilst offering deterministic positioning of the quantum dots or quantum wires on a substrate of choice. Moreover, for use of quantum dots devices as a single photon source, the quantum dots produced must also offer competitive spectral characteristics such as good uniformity and brightness.
The unique crystalline structure of layered two-dimensional (or two-dimensional layered) materials such as graphene and tungsten diselenide (WSe2) offer exciting new opportunities for quantum technologies. Two-dimensional materials exhibit a number of unusual properties compared to traditional three-dimensional semiconductor materials such as silicon (Si) or Gallium Arsenide (GaAs). In a two-dimensional material, atoms form in monolayers that are chemically bonded within the plane of the monolayer or sheet, but in which the layers are held together only through van der Waals forces. Each monolayer is naturally passivated without any dangling chemical bonds, and so no chemical bonds are formed between monolayers. Importantly, electrons, holes and many-body complexes are confined within the plane of each single monolayer and so provide an inherently two-dimensionally confined system. Quantum confinement of electrons in the two-dimensional plane leads to novel and unusual electronic and optical properties that are distinctively different from three-dimensional materials. Techniques for separation of one or a few monolayers of two-dimensional materials have been developed in recent years, thereby allowing researchers to study and develop devices in the two-dimensionally confined systems offered by layered materials. Further discussion of two-dimensional materials for nanophotonics technologies can be found in "Two-dimensional material nanophotonics" by Xia et al., Nature Photonics, 2014, vol. 8, pg. 899-907.
Naturally occurring quantum dots have been observed in layered materials such as tungsten diselenide (WSe2). Such quantum dots have been recorded particularly at the edge portions of the monolayers. Some reports have attributed quantum dot formation to crystal imperfections at the edge regions, while others claim they might be generated by atomic defects. Nevertheless, these naturally occurring quantum dots have not been reliably generated, or predictably positioned, which means than incorporating such dots into devices on a larger scale would be unworkable.
Therefore, there is a requirement for a quantum-confined device (such as a quantum dot device or quantum wire device) and its method of manufacture that is feasible on a large scale, robust and that offers deterministic placement of the quantum dots or quantum wires on a substrate. Furthermore, the generated quantum dots must have high quality optical and electrical properties.


A filler for reinforcement joint that ensures excellent fluidity and retention thereof, exhibiting appropriate length change ratio and high strength performance; and a method of reinforcement joint filling operation using the same. There are provided a filler for reinforcement joint containing a cement, an expanding material, a pozzolana micropowder, a water reducing agent and a sand, and a method of reinforcement joint filling operation using the same, characterized in that the expanding material is a calcium aluminoferrite expanding material, and that the pozzolana micropowder is a silicious micropowder having a silicon dioxide (SiO2) content of 90% or higher and having a hydrogen ion concentration falling in an acid region, and that the water reducing agent is a polycarboxylic acid water reducing agent. The calcium aluminoferrite expanding material preferably has a value of Brain specific surface area of 2000 to 6000 cm2/g. The sand is preferably a weighty sand of 3.0 g/cm3 or higher density.

Cement mortars that are prepared by adding a water reducing agent to cement have been and being popularly used for civil engineering and building construction works. Furthermore, a calcium sulfoaluminate based or lime type expansive additive and a foaming agent of aluminum powder are added to cement to make it non-shrinkage and then river sand and/or silica sand is compounded to produce paste or mortar. Materials prepared in this way are being popularly employed in construction works particularly to fill fine gaps of concrete structures and gaps produced by back-action construction method, to repair and reinforce structures and also to fill spaces under base plates of machines and apparatus and under slabs of tracks.
Generally, filling mortar materials that are used in civil engineering and building construction works are also referred to as grouts. Grouts include PC grouts, grouts for pre-packed concretes, back filling grouts for tunnels and shields, grouts for pre-casting, grouts for repairing and reinforcing structures, grouts for reinforcing joints, grouts for under bearings of bridges, grouts for under slabs of pavements and tracks, and grouts for under storage containers of nuclear power generation plants.
The quality of concrete to be used for civil engineering and building structures has been improved in recent years and accordingly mortar materials to be used as grouts are required to show a high strength, a high fluidity and a low shrinkage (see Non-Patent Document 1).    Non-Patent Document 1: "An Experimental Study on Filling Performances of High Strength Grout Materials", Summary of the Academic Lectures in the General Convention of Japan Society of Architects, No. 1313, August 1995.
Particularly, there is a demand for cement mortars to be used for filling reinforcing joints connecting reinforcements of structures of reinforced concrete or pre-cast concrete that manifests a high strength and a low shrinkage in addition to a high fluidity because of the current availability of high strength concrete for large and improved earthquake proof reinforced concrete structures that requires by turns joints showing an enhanced strength and a high resistance.
On the other hand, it is known that the use of a cement based grout composition combined with a specific water reducing agent can provide an effect of low temperature dependency, a remarkable effect of retention of fluidity and filling ability and an effect of improving the strength for a long period of time (see Patent Document 1)    Patent Document 1: JP-A-2003-171162
Patent Document 1 describes an invention of "a cement based grout composition of cement, fine aggregate, a water reducing agent, an expansive additive, inorganic finer powder and a foaming substance, characterized in that the compounding ratio of the water reducing agent is 0.05 to 4 mass portions relative to 100 mass portions of cement and the water reducing agent contains in 100 mass portions thereof a melamine sulfonic acid based water reducing agent, a naphthalene sulfonate based water reducing agent and a lignin sulfonic acid based water reducing agent respectively by 0.05 to 4 mass portions, by 10 to 30 mass portions, 55 to 85 mass portions and 5 to 20 mass portions" (claim 1) as well as a cement based grout composition according to claim 1 or 2, characterized in that the inorganic fine powder is fly ash showing a Blaine's specific surface area of not less than 4,000 cm2/g and an ignition loss of not more than 3.5% (claim 3) but it does not suggest the use of any siliceous fine powder whose silicon dioxide content ratio and hydrogen ion concentration are found within specific respective ranges. Additionally, while it describes the use of a calcium aluminoferrite based expansive additive showing a Blaine's specific surface area of 4,000 cm2/g (observed by a method conforming to JIS R 5201) (paragraph [0028]), it does not describe the use of a polycarboxylic acid based water reducing agent nor suggest the use of a combination of a specific siliceous fine powder, a calcium aluminoferrite based expansive additive and a polycarboxylic acid based water reducing agent in order to a filling material for a reinforcing joint showing an excellent retention of fluidity, a high strength and a low shrinkage.
Furthermore, a method of manufacturing mortar-concrete showing a high strength by using specific aggregate and silica fume in combination (see Patent Document 2).    Patent Document 2: JP-A-05-58701
While Patent Document 2 describes an invention of a "method of manufacturing mortar-concrete characterized by using aggregate containing quartz or feldspar and having physical properties including a specific gravity of not less than 2.58, a shear hardness of not less than 90 and a compressive strength of not less than 2,000 kgf/cm2, and water-binder ratio by not more than 25%, adding silica fume containing SiO2 by not less than 90% as admixture by 5 to 20% of the weight of the cement and preparing them by using a high performance AE water reducing agent" (claim 1). However, while it describes silica fume only in terms of SiO2 content ratio (paragraphs [0006], [0007] and [0009]), it does not describe hydrogen ion concentration nor shows it any intention of improving the fluidity. Furthermore, while it describes the use of a high performance AE water reducing agent, it does not describe anything about using an expansive additive in combination nor about manufacturing a filling material for a reinforcing joint showing properties including an excellent retention of fluidity, a high strength and a low shrinkage prepared by adding silica fume, a calcium aluminoferrite based expansive additive and a polycarboxylic acid based water reducing agent in combination.
It is also known that a cement composition of belite-rich cement, silica fume, a cement dispersant containing a polycarboxylic acid based polymeric compound having a polyalkylene glycol chain as principal ingredient, a lime based additive or an organic shrinkage reducing agent, a substance for generating pressure countering the shrinkage stress produced by the hydration reaction of the belite-rich cement and fine aggregate having a specific gravity of not less than 3.4 and a coefficient of water absorption between 0.5 and 1.5% provides a good retention of fluidity and a high strength (see Patent Document 3).    Patent Document 3: JP-A-2003-286064
Patent Document 3 describes "containing belite-rich cement as indispensable ingredient" (paragraph [0014]) and also that a composition prepared without using belite-rich cement (by using ordinary cement) showed a flow value less than 140 mm and 60 minutes after mixing and did not stably provide a high fluidity in a physical property evaluation test where a cement compound containing silica fume, a cement dispersant containing a polycarboxylic acid based polymeric compound having a polyalkylene glycol chain as principal ingredient, a lime based additive, a substance (carbon based foaming agent) for generating pressure countering the shrinkage stress produced by the hydrating reaction of the belite-rich cement and fine aggregate having a specific gravity of not less than 3.4 and a coefficient of water absorption between 0.5 and 1.5% is mixed with water added to a predetermined ratio (paragraphs [0049], [0051] and [0054]). Thus, it suggests that it is not possible to provide a cement composition having a good fluidity, a high compressive strength and a good non-shrinkage without using belite-rich cement. While the above document describes the average grain size and the carbon content of the silica fume used there (paragraph [0038]), it does not describe anything about the hydrogen ion concentration. Furthermore, it describes that a lime based expansive additive is combined with silica fume and polycarboxylic acid based water reducing agent for use (paragraph [0018]) but does not described about obtaining a filling material showing an excellent retention of fluidity, a high strength and a low shrinkage for a reinforcing joint by using silica fume, calcium aluminoferrite based expansive additive and a polycarboxylic acid based water reducing agent in combination.
It is known to use powder of fine particles containing silicon dioxide (SiO2) as principal ingredient and also zirconium dioxide as an ingredient in order to manufacturing mortar-concrete that can be handled with ease during the manufacturing process and shows a high strength and a high workability by using a water reducing agent to a small extent (see Patent Document 4).    Patent Document 4: JP-A-2004-203733
Patent Document 4 describes an invention of "a method of manufacturing mortar-concrete characterized in that it is prepared by using a mixture obtained by mixing cement, fine aggregate and powder of fine particles containing silicon dioxide (SiO2) as principal ingredient and also zirconium dioxide as an ingredient" (claim 2) and the use of "SiO2: 92.74 wt %, ZrO2: 4.76 wt %, Fe2O3: 0.35 wt %, A2lO3: 0.01 wt %, TiO2: 0.05 wt %, H2O: 0.18 wt %, Na2O: 0.02 wt %, pH: 4.2 and specific surface area: 9.22 m2/g as observed by the BET method", "density: 2.45 g/cm3, SiO2: 94.5 wt %, ZiO2: 4.0 wt %, pH: 3 to 4, average particle size: 1 μm and specific surface area: 8.7 m2/g as observed by the BET method (paragraphs [0025] and [0055]) as fine particles (special siliceous fine powder), and a polycarboxylic acid based water reducing agent (paragraph [0054]). However, as it describes that "in the method of manufacturing concrete of this embodiment, the additive of special siliceous fine particles scatters less because they have a large particle size if compared with conventional additives using silica fume of a small particle size so that it is possible to secure a correct mixing ratio and facilitate the operation (paragraph [0038]), it only says that the particle size of the siliceous fine powder is important and does not disclose any technological idea of using "siliceous fine powder having a silicon dioxide (SiO2) content ratio of not less than 90% and a hydrogen ion concentration found in an acid region" in order to obtain a filling material for a reinforcing joint showing an excellent retention of fluidity, a high strength and a low shrinkage. Additionally, the invention described in Patent Document 4 avoids the use of an expansive additive (paragraph [0006]) and therefore those skilled in the art cannot easily get to the idea of using special siliceous fine powder and a calcium aluminoferrite based expansive additive in combination on the bases of the above invention.
An invention of obtaining heavy weight mortar prepared by compounding heavy weight aggregate that shows a suppressed temperature rise without segregation of ingredients is also known (see Patent Document 5)    Patent Document 5: JP-A-2005-47772
Patent Document 5 describes "a mortar composition prepared by compounding cement, an expansive additive, a binder containing pozzolana fine powder, fine aggregate and a water reducing agent, characterized in that the fine aggregate contains particles with a particle size not greater than 0.15 mm by 10 to 20% and has a specific gravity of not less than 3.0 and a particle size of not greater than 2.5 mm, the content thereof being 200 to 300 portions relative to 100 portions of the binder" (claim 1). It also describes that silica fume is used as pozzolana fine powder (paragraph [0020]), and polycarboxylic acid based water reducing agent is used (paragraph [0025]). However, while it shows a calcium sulfoaluminate based expansive additive (paragraph [0011]), it does not describe anything about a calcium aluminoferrite based expansive additive nor describes it about the silicon dioxide content ratio and the hydrogen ion concentration of silica fume. Thus, it is not intended to dissolve the problem of obtaining a filling material for a reinforcing joint showing an excellent retention of fluidity, a high strength and a low shrinkage by using a calcium aluminoferrite based expansive additive, a special pozzolana fine powder and a polycarboxylic acid based water reducing agent in combination.
An invention of mortar that shows a high fluidity if the water-cement ratio is low and a high compressive strength of not less than 80 N/mm2 after setting in 28 days of age without showing any segregation of ingredient materials and is adapted to be suitably used as high strength non-shrinkage grout mortar is also known (see Patent Document 6).    Patent Document 6: JP-A-2005-119885
Patent Document 6 describes "a mortar composition characterized by containing (A) cement, (B) granular cement clinker and (C) one or more materials selected from a water reducing agent, ultra fine powder and aggregate showing a specific gravity of not less than 2.7" (claim 1). It also describes using a calcium aluminoferrite based expansive additive (paragraph [0020]), a polycarboxylic acid based water reducing agent (paragraph [0014]) and silica fume as ultra fine powder (paragraph [0015]) but what is actually used is a naphthalene sulfonic acid based water reducing agent and a lime based expansive additive (paragraph [0024]). Moreover, it neither describe the silicon dioxide content ratio and the hydrogen ion concentration of the employed silica fume nor the use of calcium aluminoferrite based expansive additive, specific silica fume and polycarboxylic acid based water reducing agent in combination in order to obtain an excellent retention of fluidity, a high strength and a low shrinkage. As pointed out above, the invention described in Patent Document 4 avoids the use of an expansive additive and therefore those skilled in the art cannot easily get to the idea of using special siliceous fine powder described in Patent Document 4 as ultra fine powder as described in Patent Document 6 to be used with an expansive additive in combination.

Filling material for reinforcing joint and construction method of filling reinforcing joint


A method and compound for the purification of proteins including the attachment of a non-peptidic, small compound which simulates the affinity of Protein A for immumoglobulins to a support matrix. Once attached on the support matrix, the resulting monochloro-triazine derivative is reacted with an excess of an amino compound at a higher temperature to achieve high levels of substitution. The resulting support matrix with ligand is useful in the affinity separations of antibodies. Further, a mercapto heterocyclic system ligand may be attached to the super matrix and useful in affinity separations of antibodies.

All current protein purification systems show deficiencies, especially for large-scale purifications. In particular, the purification of antibodies is inadequate as far as purity and yields are concerned. Consequently, the present state of the art processes are costly due to large volumes of solvents and long production times for making pure immunoglobulins intended for therapeutic and diagnostic applications.
In an affinity separation, the protein being purified adsorbs selectively and reversibly to a complimentary binding substance or affinity ligand, often times an antibody molecule. Affinity separation generally results in very low non-specific binding compared to other separation techniques. The very low non-specific binding makes it possible to purify a given protein from complex biological mixtures, to separate incorrectly folded forms from native molecules, and to recover the protein.
Purification systems using glass or metal tubes that contain a packed column of separation medium, for example, beads or particles, are known. These tubes are known as column boxes. Because the separation medium is compacted within the column boxes, the flow rates are slow and the column boxes have a limited capacity. Therefore, prior art purification technology has focused on increasing the porosity of the separation medium to increase the flow rates and capacity within the column box. The object of these known systems is to purify the largest amount of material within the shortest amount of time while keeping the amount of contaminants in the product low and the product yields high. One problem with the old purification technology is that increasing porosity of the separation medium achieved faster flow rates and capacity, but reduced product yields and purity.
Orbicell(trademark) cellulose beads are available from Accurate Polymers, Ltd. in Illinois and described in U.S. patent application Ser. No. 09/324,527 filed on Jun. 2, 1999 to Stipanovic et al. entitled Static Separation Method Using Non-Porous Cellulose Beads, incorporated herein by reference.
A typical affinity adsorbent consists of a solid support, a spacer arm, and a ligand. The spacer arm may encourage protein binding by making the ligand more accessible. Certain affinity separation products do not have a spacer arm of sufficient length or suitable nature so as to aid in the attachment of the target compound, for example, an antibody. In order to overcome this limitation, there is a need for a spacer arm that would allow for better orientation of the ligand, decreased steric hindrance between the target compounds, and decreased steric hindrance between the ligands thereby allowing for greater attachment of the target compound. Ease in attachment of the target compound to the ligand due to the geometry of the spacer arm and/or ligand increases target compound yield. There is a need in the art for the ligand to exhibit specific and reversible binding to the target compound, for example, a protein such as an antibody.
Affinity chromatography on immobilized Staphylococcus Aureus Protein A (SpA), Protein G and Protein M columns is a recent purification method for monoclonal and polyclonal antibody production. These bacteria-derived proteins are not only costly to produce, but also suffer from biological and chemical instability. An ability to be cleaned and sterilized is an absolute requirement by regulatory authorities for sorbents used to purify antibodies destined for therapeutic end use. Polyclonal antibodies, as well as more recently developed monoclonals, are routinely purified by affinity column chromatography. These antibodies have wide applications in diagnostic field, but lately similar antibodies are more and more finding their use in therapeutic applications. The latter application can hardly tolerate any instability of affinity sorbents, which becomes especially critical when steam, or harsh chemical sterilization procedures are mandated by regulatory agencies.
Of course, the therapeutic end-use will create a demand for much larger quantities of highly purified antibodies than the diagnostic field ever did. The first obstacle that the present state of the art-technology faces on any future scale-ups are the high cost of these bacteria-derived proteins. On top of the high cost of sorbents, will be the regulatory authorities thorough scrutiny of potential instabilities of sorbents during the required sterilization protocols. Therefore, there is a need in the art to solve these and other difficulties of the prior art.
Recent advances in molecular modeling have enabled research groups to come up with much smaller molecules than bacteria-derived proteins, which surprisingly, can still simulate high affinity and selectivity of respective bacterial proteins for numerous immunoglobulins. Said model synthetic compounds possessing affinity for antibodies, range from simple monocyclic and polycyclic compounds, to peptides of short to medium length. Some of these peptides are linear, others have macrocyclic structure.
The present invention is directed to novel ligands, a method of preparing the ligands, a method of using the ligands in the purification of compounds, and the attachment of the novel ligands to cellulose beads.
The large-scale purification of bio-molecules and, in particular, immunoglobulines, is accomplished by using a cellulose bead attached to small, non-peptidic compounds which display a high affinity and selectivity for the bio-molecule to be purified. In addition, the beads with the attached ligands of Formulas I-IV also possess a high chemical stability under rigors of recycling and sterilization. A method of purifying a compound includes providing a support matrix having a ligand of Formula I-IV thereon to a solution containing a compound to be separated, allowing for interaction of the ligand and compound to be separated, and washing the support matrix to elute the compound to be separated. In one embodiment, the support matrix may include a spacer.
The invention will best be understood by reference to the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings. The discussion below is descriptive, illustrative and exemplary and is not to be taken as limiting the scope defined by any appended claims.
In one embodiment, Formula I shows a non-peptidic, small compound that simulates the affinity of Protein A for immunoglobulins. A compound which simulates the affinity of Protein A can also be referred to as a protein A mimetic (PAM). As shown in Reaction 1, ligands of Formula I can be prepared and immobilized on Orbicell(trademark) beads having a spacer surface chemistry terminated with an amino group on a linear polyethylene glycol molecule of molecular weight with ranging between 64 and 2000 daltons. Hydrazine can be reacted with the terminal esters resulting in a molecular super-structure which is terminated with hydrazide functionalities (a). In a further embodiment, the molecular super-structure has a terminal functional group selected from the group consisting of succinimidyl, thiophenyl, 2,4-dimethoxy-s-triaznyl, cynomethyl, chloroformyl, and para-nitrophynel esters. The cellulose beads can range in size from about 0.1 microns to 20 microns. The molecular super-structure improves the geometry of the resulting attached ligands. The two terminal hydrazine groups of the molecular super-structure allow for a plurality of ligands to attach.
In one preferred embodiment, the immunoglobin to be separated is IgG. A hydrophobic interaction occurs between the IgG molecule and a mimetic SpA ligand attached to a support matrix, such as Orbicell(trademark) beads. In this manner, the IgG is separated from the solution to which are added the non-porous, cellulose beads with the attached mimetic SpA ligands. The IgG attaches to the mimetic SpA on the beads. The beads with the resulting ligand-IgG complex are washed of impurities so that a subsequent elution results in IgG and reusable beads having a regenerated ligand for repeated binding with IgG. The present ligand more easily attaches to the support matrix and has a greater reactivity with the IgG.
As shown in Reaction 1, once terminated with hydrazide functionalities, an s-triazinyl moiety (b) can be attached. The reaction with the hydrazine was achieved at the dichloro-s-triazine stage, as the second chloride is of much higher reactivity than the third chloride. Since all of the chlorides are not reacted, the compound is highly reactive and high reactivity increases yield. Once attached on the bead surface, the resulting monochloro triazine derivative (c) was forced to react with an excess of an amino compound (d) at a higher reaction temperature than used in other stages of the reaction.
The present ligand of Formula I is attached to the solid state complex (the support matrix or, for example, the Orbicell(trademark) bead) under better spatial control and has a greater reactivity with the IgG (or other target compound to be purified). At least these factors increase the total yield of the purified IgG. The hydrazine moiety on the cellulose surface reacts readily with the very reactive chloride of dichlorotriazine molecule. The desired molecular geometry of two adjacent ligand groups should result in multiple points of attachment of the IgG to the ligands. The hydrazine represents the shortest bifunctional NH2 group linker which allows optimal spatial arrangement and proximity of the ligands. Therefore, the addition of the improved ligand with the improved spatial arrangement on the surface, in conjunction with improved non-porous Orbicell(trademark) bead, increases the interaction between the matrix and the IgG (i.e., other antibody or target compound).
Very high levels of substitution of the monochloro triazine derivative were achieved. The ligand of Formula I was tested for affinity separation of antibodies. The sorbent displayed very high activity (yield of antibody was 44 mg/g of beads) and selectivity (pure antibodies by HPLC: no xe2x80x9cshouldersxe2x80x9d of impurities present).
In another embodiment, an alternative ligand that simulates Protein A activity toward immunoglobulin is derived from a meta phthalic acid derivative. As shown in Reaction 2, a molar excess of dimethyl-5-nitroisophthalate is reacted with tiramine in methanol and monoamide is isolated and crystallized (a). 5-Nitro monoamide of isophthalic acid ester is further reacted with excess of aniline, providing mixed 5-nitro bisamide (b). Hydrogenation over Pd catalyst under H2 pressure gives mixed 5-amino bisamide compound (c), SA-B.
Compound SA-B can now be grafted onto the surface of cellulose beads having a spacer arm that is carboxyl functionalized activated via N-succinimidyl ester, as shown, resulting in ligand of general Formula II.
In another embodiment, a method of manufacturing a ligand of Formula II includes reacting a (4xe2x80x2 hydroxy)phenetyalmido-1-carboxy-anilido-3-carboxyphenyl-5-amine with a terminal, activated ester functional group.
In another embodiment, a method of manufacturing a ligand of Formula III includes reacting a (a(4xe2x80x2 hydroxy) phenetyalmido-1-carboxy-anilido-3-carboxyphenyl-5-amine with a terminal tertiary dicarboxy-ethyl amine in the presence of a peptide-coupling agent.
Another alternative grafting method is based on coupling of carboxyl-functionalized beads with amino SA-B using a conventional carbodimide reagent, as shown in Reaction 4, resulting in the ligand of general Formula III shown below.
A further embodiment of the adsorbents include a non-porous cellulose bead having a diameter of approximately 0.1 to 20xcexc being pegylated on the surface with xcex1,xcfx89-diamino polyethylene glycol groups ranging in molecular weights up to approximately 60 to 2000 Daltons. The primary amines are reacted with a triepoxide to form an amino-2-hydroxy adduct. The remaining epoxides are reacted with the thiol (mercapto) heterocyclic compounds wherein the R group includes pi electron rich systems resulting in the ligands of general Formula IV. The mercapto heterocyclic compounds may be selected from the group comprising mercapto-N-methyl imidiazol, 2-mercapto pyridine, mercaptopyridine-N oxide, 2-mercaptoimidazole, 2-mercaptobenzimidazole, sodium 2-mercapto-5-benz-imidazolesulfonic acid, 2-mercapto-benzothiazole, 2-mercaptobenzoxazole, 2-mercapto-5-methylbenzimidazole, 2-mercapto-1-methylimidazole, 2-mercapto-4-methylpyrimidine, 2-mercapto-5-nitrobenzimidazole, 2-mercaptopyridine, 2-mercaptopyridine N-oxide, 2-mercapto-pyrimidine, 2-mercapto-4(3H)-quinalozine, 2-mercaptothiazoline, 2-mercapto-thiazole, 2-mercaptothiadiazole, and 5-methyl-1,3,4-thiadiazole-2-thiol and other mercapto heterocyclic compounds known to those skilled in the art. The grafted mercapto heterocyclic compounds selectively bind to biological molecules, including IgM, IgY (egg), Fab, and Fc antibody fragments in addition to the whole IgG molecule.
One skilled in the art could accomplish substitution of the phenol groups of Formulas I-IV with a thiol, amide or other equivalents. Additionally, salts of Formulas I-IV are included.
In one embodiment, the method of purification includes providing a mimetic Protein A (SpA) capable of binding immunoglobin. The mimetic Protein A is attached to a support matrix. In a prefered embodiment, the support matrix is a cellulose bead. In a preferred embodiment, the immunoglobin to be separated is IgG. An intereaction occurs between the IgG molecule and the mimetic SpA ligand. The beads with the resulting ligand-IgG complex are washed of impurities so that a subsequent elution results in pure IgG and reusable beads having a regenerated ligand for repeated binding with IgG.

Simulated activity of Protein A displayed by ligands attached to a cellulose bead surface


A zoom lens includes in order from an object side: a first lens unit having a positive refractive power which does not move for zooming; a second lens unit having a negative refractive power which moves during zooming; a third lens unit having a positive refractive power which moves during zooming; and a fourth lens unit having a positive refractive power which does not move for zooming, the third lens unit moving to an image side and then to the object side for zooming from a wide angle end to a telephoto end, in which a focal length (f1) of the first lens unit, a focal length (f2) of the second lens unit, a focal length (f3) of the third lens unit, and a lateral magnification (β3w) of the third lens unit at the wide angle end when a ray enters from infinity are appropriately set.

1. Field of the Invention
The present invention relates to a zoom lens and an image pickup apparatus including the same, and more particularly, to a zoom lens suited for use in a broadcasting television camera, a cinema camera, a video camera, a digital still camera, and a silver-halide film camera.
2. Description of the Related Art
In recent years, a zoom lens having reduced size and weight, a wide angle of field, a high zoom ratio, and high optical performance is desired for use in an image pickup apparatus, such as a television camera, a cinema camera, a film camera, or a video camera. In particular, an image pickup device such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) used in a television or cinema camera as a professional moving image pickup system has a substantially uniform resolution over the entire image pickup range. Therefore, a zoom lens using the image pickup device is required to have a substantially uniform resolution from the center to the periphery of the screen. There are also needs for reductions in size and weight for an image pickup mode that places emphasis on mobility and operability.
As a zoom lens having a wide angle of field and a high zoom ratio, there has been known a positive-lead-type four-unit zoom lens in which a lens unit having a positive refractive power is arranged closest to the object and which consists of four lens units as a whole.
For example, Japanese Patent Application Laid-Open No. H06-242378 discloses a four-unit zoom lens having an F-number of about 1.6 to 1.7 at the wide angle end, an angle of field of about 65° to 87° at the wide angle end, an angle of field of about 4° to 13° at the telephoto end, and a magnification-varying ratio of about 8 to 18. The four-unit zoom lens is constituted of a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive or negative refractive power, and a fourth lens unit having a positive refractive power. Further, the first lens unit is constituted of a first sub-lens unit having a negative refractive power, a second sub-lens unit having a positive refractive power, and a third sub-lens unit having a positive refractive power, and is configured so that the second sub-lens unit moves to the image side for focusing from the infinity side to the proximity side.
Japanese Patent Application Laid-Open No. 552-084754 discloses a four-unit zoom lens constituted of a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power. The first lens unit is constituted of a first sub-lens unit having a negative refractive power, a second sub-lens unit having a positive refractive power, and a third sub-lens unit having a positive refractive power, and is configured so that the second sub-lens unit moves to the image side for focusing from the infinity side to the proximity side.
Japanese Patent Application Laid-Open No. 2008-216480 discloses a four-unit zoom lens having an F-number of about 2.8 at the wide angle end, an angle of field of about 35° at the wide angle end, an angle of field of about 12° at the telephoto end, and a magnification-varying ratio of about 2.7. The first lens unit is constituted of a first sub-lens unit having a negative refractive power and a second sub-lens unit having a positive refractive power, and is configured so that the second sub-lens unit moves to the object side when focusing from the infinity side to the proximity side.
However, with the zoom lens disclosed in Japanese Patent Application Laid-Open No. H06-242378, realization of both the further reductions in size and weight and the high optical performance is difficult. Japanese Patent Application Laid-Open No. H06-242378 discloses in the embodiments 1 and 2 a configuration in which lens units each having a negative refractive power are arranged on the object side with respect to the stop. The diameters of the second lens unit and the lens units on the image side of the first lens unit tend to increase, which is disadvantageous in reducing the size of the zoom lens. When the refractive power of each lens unit is increased in order to reduce the size and weight, an aberration variation is increased over the entire zoom range, which makes it difficult to achieve high optical performance. Further, Japanese Patent Application Laid-Open No. 6-242378 discloses the embodiment 3 in which the third lens unit has a positive refractive power, but the high refractive power of the third lens unit increases the number of constituent lenses, which is disadvantageous in reducing the size and weight. In addition, in order to ensure enough F-number and exit pupil for the strongly convergent ray that exits the third lens unit, the number of constituent lenses of the fourth lens unit is increased, with the result that the reductions in size and weight are difficult.
On the other hand, Japanese Patent Application Laid-Open No. S52-084754 discloses an example in which the third lens unit has a positive refractive power, but the third lens unit has weak refractive power, with the result that the ray that exits the third lens unit diverges. In order to ensure enough F-number and exit pupil for the divergent ray, the number of constituent lenses of the fourth lens unit is increased, with the result that the reductions in size and weight are difficult.
With regard to the zoom lens disclosed in Japanese Patent Application Laid-Open No. 2008-216480, the refractive power and lens configuration of each lens unit is disadvantageous in further increasing the angle of field, which makes it difficult to suppress an increase in lens diameter accompanying the increase in angle of field.

Zoom lens and image pickup apparatus including the same


A thermal head includes a heat dissipating substrate, a heat-insulating layer formed thereon, a common lead layer formed thereon, an insulating interlayer formed thereon, a plurality of heating elements provided on the insulating interlayer, a common electrode connected to one end of each heating element, and a plurality of discrete electrodes connected to the other ends of the heating elements. The heating elements are connected to each other via the common electrode, and the common electrode is electrically connected to the common lead layer through a contact hole provided in the insulating interlayer. The common lead layer includes a thin region below the heating elements and a thick region.

1. Field of the Invention
The present invention relates to thermal heads mounted in thermal printers or the like. The present invention particularly relates to a thermal head which can suppress voltage drop in a common electrode and can uniformly generate heat along an array of thermal head elements formed in the vicinity of the end of a substrate.
2. Description of the Related Art
In general, a thermal recording head mounted in a thermal printer includes an array of, or a plurality of arrays of, heating elements composed of heating resistors disposed on a substrate. When these heating elements are selectively energized in response to printing information, the heat generated by the elements colors a thermal recording sheet or melts and transfers ink on an ink ribbon onto plain paper or a transparent sheet.
FIG. 15 shows a conventional thermal head. A heat-insulating layer 112 composed of a glass glaze is formed over an entire heat dissipating substrate 111 composed of an electrically insulating ceramic such as alumina. A projecting section 113 which protrudes from the heat-insulating layer 112 is formed by etching or the like in the vicinity of the end 111a of the heat dissipating substrate 111. A first common lead layer 114a with a thickness of approximately 1 .mu.m is formed on the entire heat-insulating layer 112 by a sputtering process or the like. The first common lead layer 114a is composed of a hard, heat-resistant high-melting point metal, such as chromium, having high adhesiveness to the heat-insulating layer 112. The first common lead layer 114a preferably has a large area and a large thickness of approximately 1 .mu.m to reduce resistance thereof. Furthermore, a second common lead layer 114b is deposited on the entire surface of the first common lead layer 114a by a sputtering process. The second common lead layer 114b is composed of a cermet, which is a composite material of a metal and an insulating ceramic, such as Ta--SiO.sub.2 (hereinafter, a Ta-containing cermet is referred to as a"Ta cermet").
A strip antioxidative mask layer adjacent to the projecting section 113 is formed between the end 111a of the heat dissipating substrate 111 and the projecting section 113 of the heat-insulating layer 112 and on the second common lead layer 114b. The second common lead layer 114b is heated to approximately 700.degree. C. so that the second common lead layer 114b is thermally oxidized over several thousands angstroms from the surface, except for the portion covered by the antioxidative mask layer. A first insulating interlayer 115a composed of oxide ceramic having significantly decreased defects is thereby formed.
The portion protected by the antioxidative mask layer remains as a conductive section 116. The antioxidative mask layer is removed to expose the conductive section 116 on the first insulating interlayer 115a.
A second insulating interlayer 115b composed of an insulating ceramic such as SiO.sub.2 is deposited on the first insulating interlayer 115a by a sputtering process or the like, and then a contact hole 115c is formed in the second insulating interlayer 115b so that the conductive section 116 is exposed from the second insulating interlayer 115b.
An underlying common electrode 117a composed of a high-melting point metal such as chromium is formed on the second insulating interlayer 115b so as to cover the conductive section 116. An array of strip underlying discrete electrodes 118a composed of a high-melting point metal such as chromium is formed on the second insulating interlayer 115b. These underlying discrete electrodes 118a oppose the underlying common electrode 117a at a predetermined distance above the projecting section 113.
A plurality of strip heating elements 119 composed of a Ta cermet is provided over the strip underlying discrete electrodes 118a and the underlying common electrode 117a. Thus, each heating element 119 forms a heating zone S1 between the underlying common electrode 117a and the respective underlying discrete electrode 118a.
Overlying discrete electrodes 118b composed of aluminum or copper are connected to the underlying discrete electrodes 118a through the heating elements 119. The overlying discrete electrodes 118b extend to the other terminal end of the heat dissipating substrate 111, away from the end 111a. Electrical power is supplied to each overlying discrete electrode 118b thorough the other terminal end.
An overlying common electrode 117b composed of aluminum or copper is formed on the strip heating elements 119 so as to oppose the underlying common electrode 117a. Furthermore, a protective layer 120 with a thickness of approximately 5 .mu.m is deposited over the heating elements 119, the overlying common electrode 117b, and the overlying discrete electrodes 118b other than the terminal section for an external circuit, by a sputtering process or the like. The protective layer 120 is composed of a material, such as sialon (a solid solution of a Si--Al--O--N compound), having high oxidation resistance and abrasion resistance.
These overlying discrete electrodes 118b are energized based on given printing information. A current from a overlying discrete electrodes 118b flows in the respective underlying discrete electrode 118a and the respective heating element 119, and flows in the underlying common electrode 117a, the overlying common electrode 117b, the conductive section 116, and the first and second common lead sublayers 114a and 115b toward the external circuit.
In a typical conventional thermal head including driver ICs, a glazed aluminum substrate is generally used in which a glass material is glazed on a heat dissipating substrate composed of alumina or the like. A plurality of linear heating elements is arranged in the vicinity of the end of the substrate. These heating elements are selectively energized according to recording information. The heat generated in the heating elements records dot images on thermal recording paper or plain paper by ink transfer from a thermal transfer ink ribbon provided between the thermal head and the plain paper.
FIGS. 16 and 17 are a cross-sectional view and a schematic plan view, respectively, of a main section of another conventional thermal head. A glass heat-insulating layer 202 is formed on a heat dissipating substrate 201 composed of an insulating ceramic such as glazed alumina. The heat-insulating layer 202 has a projection 202a having a trapezoidal cross-section at the end region. A first common lead layer 203a, which is composed of a high-melting point metal and has a thickness of approximately 1 .mu.m, and a second common lead layer 203b, which is composed of a cermet of a high-melting metal and SiO.sub.2 and has a thickness of approximately 1 .mu.m, are formed on the heat-insulating layer 202 including the projection 202a by a sputtering process or the like. An antioxidative conductive metal such as MoSi.sub.2 or antioxidative insulating ceramic such as SiO.sub.2 with a thickness of approximately 0.2 .mu.m is formed on the second common lead layer 203b by a sputtering process. The antioxidative material is etched to form a thermal-oxidation mask layer 204 with a predetermined pattern for providing contact holes by a photolithographic etching process.
The substrate 201 is heated to approximately 600.degree. C. to 800.degree. C. to form a first insulating interlayer 205a on the exposed region of the second common lead layer 203b which is not covered with the thermal-oxidation mask layer 204, by thermal oxidation. A second insulating interlayer 205b composed of SiO.sub.2 or the like is formed on the first insulating interlayer 205a. Such a double-layered configuration enhances reliability of interlayer insulation. A contact hole 205c is formed in the second insulating interlayer 205b at the position corresponding to the thermal-oxidation mask layer 204 by a photolithographic etching process. A substrate provided with the layered common electrode is thereby formed. An electrode material composed of a high-melting point metal such as molybdenum is deposited on the second insulating interlayer 205b by a sputtering process or the like, and an electrode pattern for an underlying common electrode 206 and underlying discrete electrodes 207 is formed by a photolithographic etching process.
A heating element layer composed of Ta--SiO.sub.2 or the like is deposited on the electrode pattern. The heating element layer is etched by a photolithographic etching process to form an array of heating elements 208 corresponding to the number of dots. Any other electrode configuration may also be employed. For example, heating elements 208 with a given pattern are previously formed, and chromium electrodes are deposited on the heating elements 208.
An aluminum or copper overlying electrode layer with a thickness of approximately 2 .mu.m is formed on the heating elements 208, for supplying electrical energy. Since the multi-layered common electrode is provided at one side of the heating elements 208, no overlying common electrode is necessary at this side. Thus, only three common terminals 209 for external connection for connecting the first and second common lead layers 203a and 203b to an external circuit are formed on three contact holes 205c provided at the two ends and in the center of the substrate 201 (see FIG. 17).
Overlying discrete electrodes 210 for independently heating the heating elements 208 are formed at the other sides of the substrate 1, and first pads 210a for connecting driver ICs 211 are formed at the ends of heating elements 208. Second pads 210b for connecting the driver ICs 211 and discrete terminals 210c for connecting the external circuit are also arranged so as to form an array including the common terminals 209 for connecting the external circuit. These terminals 209a and 210c and pads 210a and 210b are plated and connected to the driver ICs 211 and a flexible printed circuit (FPC) 213 as an external circuit by soldering or contact bonding.
A SiO.sub.2 or sialon protective layer 212 having high hardness with a thickness of approximately 5 .mu.m is formed on the heating elements 208 and the overlying discrete electrodes 210 to prevent oxidation and abrasion of these units and electrodes by a sputtering process. The protective layer 212 substantially covers the entire surface other than the terminals 209a and 210c and the pads 210a and 210b. After terminal plating, the substrate 201 is cut by a dicing process to form block thermal heads.
In a thermal printer using the conventional thermal head, the overlying discrete electrodes 210 are energized through the respective driver ICs based on the recording signals to selectively heat these heating elements 208 of the thermal head. The heated heating elements 208 transfer ink on a thermal transfer ink ribbon (not shown in the drawing) onto a recording sheet, or colors a thermal recording sheet on a platen (not shown in the drawing), to form a recorded image.
In such a conventional thermal head, the chromium first common lead layer 114a must have a large thickness or a large area in order to reduce the resistance and thus to reduce common drop of voltage in the common electrode layer which would leads to deterioration of the quality of the printed image.
When the thickness of the first common lead layer 114a composed of a high-melting point metal such as chromium is large, for example, 1 .mu.m, the layer formed by a sputtering process inevitably has large residual stress in proportion to the thickness due to large tensile stress. Thus, the interfacial bonding strength between the first common lead layer 114a and the heat-insulating layer 112 decreases by high-temperature thermal oxidation treatment for forming the first insulating interlayer 115a in the subsequent step, by thermal impact during a high-temperature high-vacuum treatment performed for stabilizing the heating elements 119, and by mechanical impact in the subsequent steps. As a result, the quality and the production yield of the thermal head products decrease.
When the common lead layers 114a and 114b are formed above substantially the entire heat dissipating substrate 111, the probability of insufficient insulation between the common lead layers 114a and 114b and the overlying discrete electrodes 18b due to defects in the insulating interlayers 115a and 115b increases in proportion to the area of the common lead layers 114a and 114b, resulting in decrease in the quality and the production yield of the thermal head products.
Since a chromium first common lead layer 114a having a large thickness of 1 .mu.m and high thermal conductivity is present below the heating zone S1, the first common lead layer 114a dissipates heat generated in the heating zone S1. Thus, the heating zone S1 cannot be rapidly heated, and the quality of the printed image deteriorates due to decreased thermal printing efficiency.
Since the first common lead layer 114a and the second common lead layer 114b are formed above the entire heat dissipating substrate 111, the first and second common lead sublayers 114a and 114b are exposed at the end 111a of the heat dissipating substrate 111. As a result, leakage and short-circuiting to external units will occur.
As described above, three contact sections of the common terminals 209 for connecting the external circuit and the common lead layers 203a and 203b are provided at both ends of the substrate and in the center of the array of the heating elements 208. Thus, the common lead layers 203a and 203b between the common terminals 209 for connecting the external circuit and the heating elements 208 inevitably have a large length L, and the current path lengths to the heating elements 208 are different from each other.
On the other hand, the common lead layers 203a and 203b are composed of a high-melting point metal having larger resistivity than that of aluminum or copper. Since the distances between the heating elements 208 and the common terminals 209 for connecting the external circuit are different from each other, the resistances of the common electrode to the heating elements 208 are also different from each other. Thus, the array of the heating elements does not have a uniform temperature distribution which is essential for uniform recording density. When the thickness of the common lead layers is increased in order to solve such a problem, the hard film composed of a high-melting point metal has large tensile strength causing production defects such as interlayer separation, resulting in decrease in quality and yield.
When the common lead layers contain a thick metal layer, heat generated in the heating elements readily dissipates through the metal layer. Thus, the thermal head has low thermal efficiency.