A DNA molecule having a gene expression repressing function derived from human T-cell leukemia virus type I (HTLV-I) existing in a region which is missing in a mutant provirus that is expressing p21Xm RNA but exists in the genome of a complete provirus, and a plasmid including the DNA molecule are provided. Furthermore, a novel protein (TRP-1) which specifically binds to U5RE and a structural gene for the protein is provided, which can be useful for elucidation of the transcription repression activity and elucidation of the oncogenesis mechanism of neurocytes, in which a transcriptional repressive region (U5RE) existing in the U5 region of human T-cell leukemia virus type I gene LTR is involved. Furthermore, an expression vector including the gene, a transformant into which the expression vector is introduced, and a process for producing the TRP-1 protein using the transformant are provided.

In 1980, Human T-cell leukemia virus type I (HTLV-1) became the first retrovirus discovered in humans. It has been revealed that infection by this virus causes diseases such as adult T-cell leukemia (ATL), HTLV-I associated myelopathy (HAM), and tropical spastic paraparesis (TSP), and that the symptoms of such diseases develop after a long period of time in the body, with an average latency of about 40 to 50 years after the infection with the virus. However, little is known about the mechanisms of its latent infection and onset.
The gene of HTLV-I includes a tax/rex region in addition to three regions which are common to animal retroviruses, i.e., a gag region, a pol region, and an env region. The tax/rex region, which is located downstream of env, is considered to have an important role in the expression of viral gene and the onset of ATL. The mRNA of tax/rex results after double splicings from a primary transcript of the HTLV-I gene, and includes two overlapping open reading frames. From one open reading frame is translated a 40 kilodalton protein called Tax, which acts on the LTR of the virus itself as well as promoters of various genes in cells to activate transcription. From the other open reading frame is translated a 27 kilodalton protein called Rex, which controls the processing of the viral RNA occurring within the nucleus after transcription, and positively acts on the transport to the cytoplasm of unspliced mRNA.
From a different start codon within the same open reading frame as that of the Rex protein, a 21 kD protein called p21X is translated. The inventors revealed that p21X is translated from the p21X mRNA which lacks the second exon through single splicing from the HTLV-I gene (Orita et al. FEBS Lett., 295, 127-134 (1991)). However, the functions of the protein are unknown. The inventors further discovered that the p21X mRNA is expressed by a mutant provirus having a deletion in a broad region encompassing the gag, pol, and env regions in a HTLV-I infected cell line (Orita et al. Nucleic Acids, Res., 21, 3799-3807 (1993)). Moreover, the inventors discovered that the p21X mRNA is also expressed by the abovementioned mutant provirus in peripheral blood lymphocytes of patients infected with HTLV-I. On the other hand, it is known that the expression of mRNA for the tax/rex region from a complete provirus is rarely observed in the peripheral blood of patients infected with HTLV-I, and is detectable in vivo only by the RT-PCR method, which is an ultra-sensitive detection method. However, once peripheral blood lymphocytes of patients infected with HTLV-I are transferred to a culture system in vitro, its expression is known to become high enough to be easily detected (Kiyokawa et al., Proc. Natl. Acad. Sci. USA., 82, 8359-8363 (1985)). Moreover, the expression of the p21X mRNA has also been found to be on the same level before and after the culture of the aforementioned peripheral blood lymphocytes of patients infected with HTLV-I (Orita et al., J. Gen. Virol., 73, 2283-2289 (1992)). Therefore, it was considered that, in vivo, the p21X mRNA is expressed without being repressed, whereas the expression of the mRNA for tax/rex is repressed.
It is considered that HTLV-I and human immunodeficiency virus (HIV), which is a kind of RNA virus, delays splicing reactions by making the splicing signal within a DNA sequence a non-optimal one, thereby providing time for the Rex protein of HTLV-I or the Rev protein of HIV to repress splicing reactions (Chang, D. D. and Sharp. P. A., Science, 249, 614-615 (1990)). It is considered that sufficient amounts of the Rex protein and the Rev protein need to be expressed and accumulated within the nucleus in order to be polymerized, before their functions can be exhibited to promote the repression of the splicing of the viral mRNA having RXE (Rex responsible element) or RRE (Rev responsible element) and the transport to the cytoplasm, thereby triggering the replication of the viruses (expression of the structural proteins) (Inoue et al., Proc. Natl. Acad. Sci. USA., 84, 3653-3657 (1987); Hidaka et al., EMBO J., 7, 519-523 (1988); Seiki et al. Proc. Natl. Acad. Sci. USA., 85, 7124-7128(1988); and Hanly et al. Genes Dev., 3, 1534-1544(1989)).
The above indicates that at least two regulatory factors, i.e., Tax and Rex proteins, are translated from the pX region characteristic of HTLV-I, and that these factors are necessary for the replication of HTLV-I. Tax is a transcription activation factor which acts on the LTR (long terminal repeat) and also activates various cellular genes. Tax also has an ability to transform certain types of cultured cells. Thus, the possibility of Tax being involved in the oncogenesis of a cell by HTLV-I is suggested.
The expression of the HTLV-I gene is known to be very low in periods of inapparent infection and to be low even after the onset of ATL. Therefore, in order to elucidate the mechanism of latent infection of HTLV-I, it is considered important to study the expression repression mechanism of the viral gene. It is known that the expression control of the HTLV-I gene is performed mainly on the LTR of HTLV-1. The LTR region is subdivided into three regions called U3, R, and U5. The U3 region includes a sequence on which Tax acts, as well as sequences acted upon by CREB, ETS, AP1, etc., which are cellular transcription activation factors. The R region is known to include a sequence to which YB-1 binds to activate transcription (Kashanchi et al. J. Virol., 68(1): 561-565 (1994)). Moreover, the R and U5 regions include a region which functions repressively with respect to the HTLV-I gene expression on the transcription level or post-transcriptionally (Xu et al., Mol. Cell. Biol., 14(8): 5371-5383 (1994); and Seiki et al., Virology, 176: 81-86 (1990)). Furthermore, the inventors recently discovered a novel transcriptional repressive sequence (U5 repressive element; U5RE), and reported the existence of three proteins of 110 kDa, 80 kDa, and 70 kDa which specifically bind to U5RE (Okumura et al. FEBS Let., 356: 94-100 (1994)).

DNA molecule relating to suppression of gene expression and novel protein


In order to visualize or calculate a volume or an area of a structure modeled by using object types that overlap, topological items of boundary representations of the objects are provided with information on whether a topological item is indicated as clipped or not clipped; and topological items indicated as not clipped are used and topological items indicated as clipped are ignored when a model for the structure is visualized or used for volume or area calculations.

The development of data processing systems, computers and computer applications has transformed different processes into computerized processes. One example of such a process is modeling. Modeling means that a model is created from a product under design for describing the product to be constructed, the model containing at least information needed to illustrate the product. A product may be composed of one or more articles. Computer applications typically apply predefined object types that are provided with values in connection with the modeling to create objects (models) of articles that exist or will exist (or at least are planned to exist) in the real world. Examples of these object types in the field of building modeling include beams, columns, plates and slabs. A product model may in principle comprise an unlimited number of objects.
Typically a product comprises real world articles that may be in touch with each other or have no contact. Real world articles may not overlap with each other. A corresponding model may comprise for a real world article one or more objects that may overlap with each other or be in touch with each other as well as have no contact. Especially, if an article has a complicated shape, it is common to model the article by using basic object types. Examples of such basic object types include a cube, a rectangle, a ball and a parallelogram. Even not so complicated shapes are easier to model by using basic object types that overlap as is obvious from FIG. 2A illustrating a single article (structure) and FIG. 2B showing basic objects used for forming the single article.
For illustrating the article or calculating filling volumes, like the amount of concrete needed to obtain a corresponding cast-in-situ structure (article), the basic objects are merged. One possibility to merge the objects is to use Boolean operations (union, intersection and difference), for example as described in "Boolean operations on multi-region solids for mesh generation" by André Maués Brabo Pereira, Marcos Chataignier de Arruda, Antônio Carlos de O. Miranda, William Wagner M. Lira, Luiz Fernando Martha, Engineering with Computers, July 2012, Volume 28, Issue 3, pp 225-239, DOI 10.1007/s00366-011-0228-8. The result of the merging by using Boolean operations is a single object formed by a real union of the merged objects. However, especially for complex models, forming the required real union is a rather complicated mechanism that uses quite a lot of computing capacity.


A method for performing Device-to-Device (D2D) communication in a wireless communication system according to the present invention, the method according to the present invention comprises transmitting, by a D2D transmitting UE, a first message requesting allocation of radio resources to be used for D2D communication to an eNB; receiving, by the D2D transmitting UE, a second message including radio resource allocation information from the eNB; and transmitting, by the D2D transmitting UE, data through a radio resource area allocated by the second message, wherein the data are transmitted to the eNB and at least one D2D receiving UE.

D2D communication refers to a radio technology which enables a plurality of devices (for example, a plurality of terminals) to exchange voice, data, and so on directly with each other without involving a base station. D2D communication includes UE-to-UE communication and peer-to-peer communication. Also, D2D communication can be applied to Machine-to-Machine (M2M) communication, Machine Type Communication (MTC), and others.
D2D communication is being considered as one of solutions that can relieve the burden of a base station due to rapidly growing data traffic. For example, different from existing wireless communication systems, D2D communication enables devices to communicate data directly with each other without employing a base station, thereby reducing overload on a network.
Also, D2D communication provides advantageous effects such as simplification of a procedure in a base station, reduction of power consumption for devices participating in D2D communication, increase of data transmission speed, extension of network capacity, distribution of communication load, and extension of cell coverage.

Method and apparatus for conducting device-to-device communication in wireless communication system


The object of the present invention is to provide a hard disk drive device having a bearing device of larger size and sufficient strength, improved impact resistance, high accuracy of rotation, and high reliability. In accordance with the present invention, a hard disk drive device comprises a motor including: a rotor or hub having around an outer periphery thereof a downwardly depending flange, wherein the hub is journalled rotatably on a base by way of a bearing; the hub provided with a magnet on the inner peripheral surface of the downwardly depending flange; a stator provided on the base so as to be opposed face to face with the magnet, the stator including coils; and a magnetic disk or disks having a central aperture to be fitted around the outer peripheral surface of flange provided around the hub of the motor, the magnetic disk adapted to be rotated by the motor; wherein the inner diameter of the downwardly depending flange of the hub of the motor is enlarged, so that the outer and inner diameters of the magnet confined within the downwardly depending flange, and the outer and inner diameters of the stator are also enlarged to allow the outer diameter of the bearing device to be enlarged.

1. Technical Field
The present invention relates to an improvement of a hard disk device employed, for example, for sorting data magnetically in computers.
2. Description of the Prior Art
A hard disk drive device includes a magnetic disk or disks for storing magnetic data. Such disks are mounted on a hub, i.e., the rotational member of a motor. In order to write the desired magnetic data into a sector on the magnetic disk or to read the data therefrom, the disk or disks are rotated at high speed by moans of the motor.
In recent years, it is desired to provide a smaller, thinner, and lighter weight, as well as impact resistant magnetic storage means, especially a hard disk drive device.
When impact is applied to the hard disk means, the impact energy is apt to be concentrated in the bearing means journalling the rotor or hub of the motor for driving the magnetic disk, so that the bearing means is the element that is most liable to be damaged.
When the bearing means is damaged, the accuracy of rotation of the magnetic disk will diminish, the reading and writing of the magnetic data can not be accomplished accurately, and noise and vibration are produced.
One of the countermeasures which can be taken for preventing the damage to the bearing means is to strengthen the bearing means itself. This countermeasure is confronted with the problem that the magnetic disk is fabricated under a predetermined standard to have an outer diameter of 2.5 inches or 3.5 inches, and the central aperture thereof is also restricted by such a standard to have an inner diameter of 20.0 mm or 25.0 mm respectively. In other words, the outer diameter of the hub as well as that of the magnet and/or the stator are also adapted to be defined under the standard in accordance with the diameter of the central aperture of the magnetic disk, so that a bearing means of sufficient size and strength can not be used.
It is not necessary to make the diameter of the central aperture of the magnetic disk as mentioned above. However, a magnetic disk having a central aperture of a diameter larger than that defined under the predetermined standard and a hard disk drive means including a motor larger in the outer diameter of its hub for driving such disk have not been realized. This is because the enlargement of the diameter of the central aperture of the magnetic disk leads to a reduction of the surface area of the magnetic disk and of the capacity of the memory for storing magnetic data.
Although the countermeasure that reducing the radial thickness of said magnet and/or the radial length of the stator to provide a space required for enlarging the bearing means can be taken, this will have an adverse impact on the function of the motor such as the rotational torque or the rotational speed. In this connection, this countermeasure can not be adopted.
Accordingly, the object of the present invention is to provide a hard disk drive device having a bearing means of larger size and sufficient strength, improved impact resistance, high accuracy of rotation, and high reliability.
These and other objects are achieved by a hard disk drive device comprising a motor including a rotor or hub and a stator, and a magnetic disk. The hub has a flange depending downwardly from the outer periphery thereof. The hub is journalled rotatablly on a base by means of a bearing means. The hub is provided with a magnet on the inner peripheral surface of the downwardly depending flange. The stator is provided on the base so as to opposed face to face with said magnet. The stator includes coils The magnetic disk or disks having a central apparatus to be fitted around the outer peripheral surface of the flange provided around the hub of the motor. The magnetic disk is adapted to be rotated by means of said motor. The inner diameter of the downwardly depending flange of said hub of the motor is enlarged, so that the outer and inner diameters of the magnet confined within the downwardly depending flange, and the outer and inner diameters of the stator are also enlarged to allow the outer diameter of the bearing means to be enlarged.


A satellite, especially a geostationary satellite which may be stabilized in its three major axes and which has a spin wheel or momentum wheel supporting a position control system and which also has an engine or propelling system, is controlled by actuating the spin or momentum wheel at the latest when the satellite is in a phase of being transferred from one orbit to another orbit. Thereafter, the satellite is rotated about its axis which extends in parallel to the axis of the spin wheel or momentum wheel whereby the rotational impulse of the satellite is smaller than that of the momentum wheel. The stabilizing of the satellite relative to the three major axes is then made at the point in time when the satellite is to change from one orbit to another orbit whereupon the engine system for reaching the new orbit is switched on. The thrust of the engine system is so dimensioned that the position control system intended for a subsequent mission retains its orientation even during the phase of changing orbits. At least one momentum or spin wheel is effective in the position control of the satellite in each operational phase of the satellite. A drive or propelling system for a position control in the three axial directions is provided along with liquid fuel drive engines for the orbit change and for the orbit correction.

The present invention relates to a method and apparatus for controlling a satellite. More specifically, the method and apparatus relates to controlling the position and varying the orbit of a satellite which may be stabilized in three major axes. The present method and system is especially adapted for a geostationary satellite equipped with propelling systems and at least one position control system supported by a spin or momentum wheel.
In order to maximize the payload, especially in geostationary satellites, it is customary to propel the satellite first into an elliptical transfer orbit. Such orbit has an apogee with a height corresponding approximately to the subsequent orbital height of a geostationary satellite. Such transfer orbit has a low perigee in the range of a few one hundred kilometers. Following any desired number of orbits in the transfer orbit, the satellite is lifted in the apogee of the transfer orbit into an orbit in synchronism with the earth, whereby the lifting is accomplished with a driving or propelling system also referred to as the apogee engine. In addition to the apogee engine there is provided an orbit correction system which serves for precisely adjusting the orbital speed in terms of centimeters per second in order to assure a good synchronization with the rotation of the earth. These propelling or drive systems also control the steering of the satellite into the desired position and the maintaining of such position during the useful life of the satellite thereby compensating for any attraction caused by the sun, the moon and also correcting any orbit distortions caused by solar pressure.
Such propelling systems may also be employed for the steering of satellites into any desired flying trajectories not geostationary whereby such satellites may be intended for other missions.
Heretofore, it was customary to use in connection with satellites of the mentioned type different propelling and position control methods for the two basically different maneuver phases, namely transfer trajectory and orbit, for example, such as a geostationary orbit.
The necessity to use different position control methods during the two maneuvering phases results from the fact that heretofore a solid fuel engine was used for the apogee engine or motor. However, the thrust of solid fuel engines is relatively high. As a result, the passive gyro stabilization by means of a spin wheel or momentum wheel alone is not strong enough. This is so during the change of orbit phase as well as in any other trajectory or orbit correction which may subsequently become necessary. Such momentum or spin wheels are insufficient to take up the high moments which occur as the result of the use of solid fuel engines. Thus, according to the prior art it is customary to use in the transfer phase a momentum or spin stabilization. If the satellite is of elongated construction, the spin is applied generally around the axis of the smallest main or primary moment of inertia. An elongated satellite, incidentally, is best adapted to the space available in the nose cone of a rocket. The application of a spin about the axis of the smallest moment of inertia, however, results in a rotation which is not stable so that nutations which cannot be avoided due to disturbances, must be constantly counteracted by a positive or active nutation damping.
Solid fuel engines are also employed in order to minimize or avoid the vibration and dynamic stabilization problems which occur in the fuel tank system of liquid fuel engines. In connection with the just described technical concept of the prior art to employ a solid fuel engine as an apogee engine or as a trajectory or orbit change engine and to employ different methods of stabilization, difficult maneuver sequences cannot be avoided. Further, a high material expense which diminishes the payload and which increases the costs can also not be avoided. Furthermore, it is difficult to guess that nutations that might occur in outer space, not to speak of testing such nutations. As a result, it is very critical to design and construct the active nutation damping. In addition, it is sensible to make the trajectory or orbit corrections, which are necessary during the entire useful life of a satellite, by means of liquid fuel drive systems or engines. Thus, at least two different engine systems must be provided for the change of orbit on the one hand and for the position control or orbit correction on the other hand. Such different drive systems based on different types of fuels require separate storage and separate conduit systems as well as separate instrumentation and so forth. An example of the just described prior art technique is described in the RCA Paper, 1975 under the title "RCA's Three Axes Communication Satellite" (RCA-SATCOM Satellite).

Method and apparatus for controlling a satellite

Messerschmitt-Bolkow-Blohm Gesellschaft mit beschrankter Haftung


A vehicle is equipped with a coupling such as, for example, a center differential or a variable clutch, that transmits a driving force from an engine to a front-wheel drive shaft and a rear-wheel drive shaft while allowing a difference in rotational speed therebetween and a brake controller that individually controls braking forces to be applied to wheels in accordance with a running state of the vehicle. A vehicular brake controller prohibits braking force control from being started if the coupling is in its locked state or when the coupling causes a relatively great connecting strength to exist between the front-wheel and rear-wheel drive shafts. While braking force control is being performed by the brake controller, braking force control is continued even if there is a command to cause the coupling to be locked or to achieve the great coupling strength.

The disclosure of Japanese Patent Application No. 2000-231989 filed on Jul. 31, 2000, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of Invention
The invention relates to a vehicular brake control apparatus and a vehicular brake control method for individually controlling brakes that are provided in wheels respectively and stabilizing a running state of the vehicle.
2. Description of Related Art
There has been conventionally known a vehicle behavior control apparatus that individually controls brakes that are provided in wheels respectively to stabilize a running state of the vehicle. For example, Japanese Patent Application Laid-Open No. 8-310366 discloses a technique in which, in the circumstance where the vehicle behavior is about to shift to a spin tendency or a drift-out tendency, braking forces for wheels are adjusted in accordance with an actual state of the vehicle behavior in such a manner as to curb the shift. For example, in a vehicle equipped with a center differential that transmits a driving force from an engine to front-wheel and rear-wheel drive shafts while allowing a difference in rotational speed therebetween, if a differential mechanism of the center differential has been locked through operation by a driver, front-wheel-side and rear-wheel-side rotational speeds are locked with respect to each other. Namely, the sum of wheel speeds of the front-left and front-right wheels and the sum of wheel speeds of the rear-left and rear-right wheels always coincide with each other. Thus, if a braking force has been applied to the turning-wise outside front wheel to reduce a speed thereof to a certain extent, one of the following influences, i.e., (a) an increase in speed of the turning-wise inside front wheel, (b) a decrease in speed of the turning-wise inside rear wheel, and (c) a decrease in speed of the turning-wise inside and outside rear wheels emerges to an extent corresponding to a decrease in rotational speed of the turning-wise outside front wheel. In a front-wheel-drive vehicle or a four-wheel-drive vehicle based on a front-wheel-drive mode, the process of estimating a vehicle speed is performed based on a speed of the turning-wise inside front wheel. Therefore, the estimated vehicle speed is high in the case of (a). This causes a rise in target speed of the turning-wise outside front wheel and thus a decrease in braking force applied to the turning-wise outside front wheel. Further, if the speed of the turning-wise inside rear wheel has decreased and the brake has been applied as in the case of (b), a moment promoting a spin tendency acts on the vehicle body. Moreover, if a braking force has also been applied to the turning-wise outside rear wheel as in the case of (c), the tire side force on the rear-wheel side decreases. This affects controllability of the vehicle behavior.
Thus, if turning behavior control of the vehicle is started in the circumstance where the center differential has been locked, driveability of the vehicle may be affected.
Further, if it has been required to lock the center differential through operation by a driver or the like in the circumstance where such brake control of the vehicle has once been started, it is for instance contemplable to lock the center differential according to the requirement and suspend brake control correspondingly. However, if brake control has been suspended before its completion, the spin/drift-out curbing effect to be exerted by brake control may be degraded.
The invention has been made to address the above-described problems. It is one object of the invention to provide a vehicular brake control apparatus and a vehicular brake control method capable of desirable vehicular brake control taking into account a connecting state between front-wheel and rear-wheel drive shafts, a timing for changing the connecting state, and a timing for performing brake control.
A vehicular brake control apparatus according to a first aspect of the invention comprises (a) a connecting state coupling interposed between a front-wheel drive shaft that transmits a driving force to a front-wheel side and a rear-wheel drive shaft that transmits the driving force to a rear-wheel side, and that changes a connecting state between the front-wheel drive shaft and the rear-wheel drive shaft, (b) brakes, each of which is provided in a corresponding one of wheels to apply a braking force to the corresponding one of the wheels, and (c) a brake controller that performs operation control of the brakes in accordance with a running state of the vehicle and that controls braking forces to be applied to the wheels individually. The brake controller prohibits brake control even if conditions for starting brake control by the brake controller have been fulfilled during a period in which the coupling causes a great connecting strength to act between the front-wheel drive shaft and the rear-wheel drive shaft. The brake controller continues brake control even if the connecting state between the front-wheel drive shaft and the rear-wheel drive shaft has been changed during performance of the brake control such that the great connecting strength acts therebetween.
According to the first aspect, while a great connecting strength acts between the front-wheel and rear-wheel drive shafts (hereinafter referred to as xe2x80x9cbetween both the drive shaftsxe2x80x9d in this section), front-wheel-side and rear-wheel-side rotational speeds are more likely to be locked with respect to each other, in comparison with the case where a small connecting strength acts therebetween. Thus, if brake control has been performed for a specific one of the wheels, rotating states of the other wheels are affected. Therefore, in some cases, the effect to be exerted by the brake controller is not achieved sufficiently. To overcome this problem, brake control is prohibited even if the conditions for starting brake control by the brake controller have been fulfilled during a period while a great connecting strength acts between both the drive shafts.
Further, assuming that the connecting strength between both the drive shafts has become great while brake control is being performed by the brake controller, if brake control is suspended immediately on the ground that the connecting strength has become great, brake control is suspended immediately in the circumstance where the running state of the vehicle is about to be stabilized. Thus, in some cases, the effect of brake control is not achieved sufficiently. To overcome this problem, brake control is continued by the brake controller even if the connecting strength between both the drive shafts has become great while brake control is being performed by the brake controller.
In the above-mentioned first aspect, it may be determined whether or not both the drive shafts have been locked with respect to each other by the coupling, so as to determine whether or not the connecting strength between both the drive shafts has become great.
Further, in the case where the connecting strength between both the drive shafts becomes great temporarily, e.g., for a short period that can be determined in advance, if brake control that is being performed is suspended during that period, the effect of brake control may deteriorate correspondingly. To overcome this problem, brake control may be continued by the brake controller while a great connecting strength acts between both the drive shafts temporarily.
Further, in a vehicle that can change over between two-wheel-drive and four-wheel-drive modes, the connecting state coupling operates during a changeover operation between the two-wheel-drive and four-wheel-drive modes, and a great connecting strength acts between both the drive shafts temporarily. Brake control may also be continued by the brake controller in such a case.
A vehicular brake control apparatus according to a second aspect of the invention comprises (a) a connecting state coupling interposed between a front-wheel drive shaft that transmits a driving force to a front-wheel side and a rear-wheel drive shaft that transmits the driving force to a rear-wheel side, and that changes a connecting state between the front-wheel drive shaft and the rear-wheel drive shaft, (b) brakes, each of which is provided in a corresponding one of wheels to apply a braking force to the corresponding one of the wheels, (c) a controller that performs operation control of the brakes in accordance with a running state of the vehicle and that controls braking forces to be applied to the wheels individually, and restricts changes in the connecting state by the connecting state coupling while brake control is being performed by the controller.
According to the second aspect of the invention, in the circumstance where brake control is being performed by the controller, even if it has been required to perform an operation that necessitates changes in the connecting state between the front-wheel drive shaft and the rear-wheel drive shaft, e.g., to lock the center differential or perform changeover between the two-wheel-drive and the four-wheel-drive modes, changes in the connecting state caused by the connecting state coupling are restricted by the controller. Therefore, changes in the connecting state caused by the controller are restricted, and desirable brake control is performed by the controller.
Further, in a vehicle that can change over between two-wheel-drive and four-wheel-drive modes, the connecting state coupling operates during a changeover operation between the two-wheel-drive and four-wheel-drive modes, and a great connecting strength acts between both the drive shafts temporarily. Thus, while brake control is being performed, the changeover operation between the two-wheel-drive and four-wheel-drive modes may be prohibited by the controller.
Further, both the drive shafts may be prohibited from being locked with respect to each other by the controller even if it has been required, e.g., to lock the center differential while brake control is being performed by the controller.
Further, if it has been required, e.g., to lock the center differential or perform changeover between the two-wheel-drive and four-wheel-drive modes while brake control is being performed by the controller, the required operation may be invalidated (prevented from occurring) through operation of the controller. If the required operation remains invalid even after the running state of the vehicle has been stabilized by brake control, the driver is forced to make the same requirement again. To overcome this problem, the required operation is automatically performed after completion of brake control. Thus, the requirement can be satisfied promptly without forcing the driver to make the same requirement (request) again.
In the above-mentioned first and second aspects of the invention, the controller may individually control braking forces to be applied to the wheels such that turning behavior of the vehicle is stabilized, if turning behavior of the vehicle is in a predetermined state.
Even if the vehicle has assumed a spin or drift-out tendency, this tendency is curbed by the controller constructed as described above. As a result, turning behavior of the vehicle is stabilized.
The aspects of the invention are not to be limited to the vehicular brake control apparatus as described above. According to other aspects of the invention, there is, e.g., provided a vehicle equipped with a brake control apparatus or a vehicular brake control method.

Vehicular brake control apparatus and vehicular brake control method


In a data processing system, an input output bus unit (IOBU) is connected to one end of an input output interface controller (IOIC) via an asynchronous bus. The other end of the IOIC is connected to a storage controller (SC) and an input output interface unit (IOIU) via a synchronous bus. The SC and IOIU are connected to a memory unit and an instruction processing unit. The asynchronous bus, which is comprised of three sub-buses and a control bus, conducts signals between the IOIC and an IOBU in an asynchronous "handshaking" manner. The synchronous bus, which is comprised of two sub-buses and a control bus, conducts signals between the IOIC and the SC/IOIU in an synchronous manner. The IOIC, interconnected between the synchronous bus and asynchronous bus, functions as a buffer between the faster synchronous bus and the slower asynchronous bus. Various operations are performed between an IOBU and the memory unit via the asynchronous bus, IOIC, synchronous bus, and SC/IOIU, such as a unit operation, a storage operation, and a message acceptance operation.

The subject matter of this application relates to computer systems, and more particularly, to a new implementation of buses and interface circuits which interface peripherals to storage controllers and main memory. This application describes a new implementation of a slower asynchronous first bus, a faster synchronous second bus, and an interface controller which interconnects and buffers the slower first bus to the faster second bus.
Computer systems include peripheral input output (I/O) equipment which must communicate with an instruction processing unit (IPU) and a main memory. This communication occurs via a bus, interconnecting the IPU and main memory to the peripheral equipment, for transmitting commands, instructions and data from the IPU/main memory to the peripherals and from the peripherals to the IPU/main memory. There are different types of buses. Some are faster, in their operation, than others. If a faster bus were to interface with a slower bus, the faster bus would overrun the slower bus. In addition, the needs of the IPU/main memory are different than the needs of the peripherals. Therefore, a second bus, for transmitting commands, instructions and data from and to the IPU/main memory, must be different than a first bus for transmitting commands, instructions and data from and to the peripherals. Consequently, a need exists for the first bus, for communication with the peripherals, the second bus, for communication with the IPU/main memory, and an interface circuit, interconnecting the two busses, for interfacing and buffering the first bus with the second bus.

Input output interface controller connecting a synchronous bus to an asynchronous bus and methods for performing operations on the bus

International Business Machines Corporation


A toothed belt having a body with a length, laterally spaced sides, an inside and an outside, and defining a plurality of teeth spaced in a lengthwise direction on one of the inside and the outside of the body. The body is defined at least in part by a rubber composition made up of at least an ethylene propylene diene monomer (EPDM) and a diene rubber. A cloth layer is provided on the teeth on the one of the inside and the outside of the body. The cloth layer is treated with a resorcin-formalin-latex solution.

1. Field of the Invention
This invention relates to endless, toothed belts, and, more particularly, to a toothed belt used to frictionally convey flat objects, such as paper money, cards, tickets, and the like.
2. Background Art
A prior art system for conveying thin articles, such as paper money, cards, tickets, etc. is shown at 10 in FIG. 1. The conveying system 10 includes cooperating, endless, toothed belts 12, 14, each having a similar construction. The belt 12 is trained around spaced drive and driven pulleys 16, 18, respectively, which pulleys 16, 18 have parallel rotational axes 20, 22. The belt 14 is trained around drive and driven pulleys 24, 26, which pulleys 24, 26 are rotatable about axes 28, 30, that are parallel to each other and the axes 20, 22 associated with the belt 12. The drive pulley 16 rotates in the direction of the arrow 32, with the drive pulley 24 rotating in the direction of the arrow 33.
The belts 12, 14 are arranged so that outside conveying surfaces 34, 36 on the belts 12, 14 are in contact over a substantial length thereof at the region 38. An article 40 to be conveyed, which article 40 may be paper money, cards, tickets, or the like, is advanced between the belts 12, 14 in the direction of the arrow 42. The article 40 is frictionally driven by the belt surfaces 34, 36 from right to left in FIG. 1 with the belts 12, 14 advancing as previously described. Spaced pressing rollers 44, 46 are selectively movable downwardly in FIG. 1 against the inside of the belt 12 at the region 38 to thereby deform and press the belt 12 towards backing rollers 48, 50, aligned with the pressing rollers 44, 46 and acting against the belt 14, to vary the pressing force between the belt surfaces 34, 36 at the region 38.
Ideally, the coefficient of friction between the article 40 and belt surfaces 34, 36 remains relatively constant through significant temperature variations, preferably in the range of -20.degree. C. to 60.degree. C. Still further, it is desirable that the flexibility and wear resistance of the belts 12, 14 do not significantly change with the belts 12, 14 operating within this temperature range. It is also important that the belts 12, 14 do not stain the articles 40 which are conveyed thereby.
It is known to construct toothed belts, such as those 12, 14, disclosed in FIG. 1, using chloroprene rubber. These belts have a plurality of regularly spaced teeth on an inside surface and an outside part within which load carrying cords are embedded.
It is also known to place a cloth covering over the surface of the teeth on this type of belt. One known cloth layer has a warp and a weft with the weft being defined by crimped 6 nylon or 6,6 nylon. The warp is an uncrimped thread of 6 nylon or 6,6 nylon, preferably with the same composition as the weft.
It is also known to enhance the adherence of the cloth to the belt teeth by using an adhesion treatment with a resorcin-formalin-latex solution (RFL). This solution is applied to the rubber using a soaking or a spreading treatment process.
Even when a chloroprene rubber which does not readily crystallize at low temperatures is used, when the chloroprene rubber is used alone, a decrease in the frictional coefficient between the belt and the articles to be conveyed may result at low temperatures. To compensate for this, the gripping force between the belts 12, 14 has been increased by deforming the belt through the pressing rollers 44, 46.
By urging the pressing rollers 44, 46 against the belt 12, the tension thereon increases. As a result, the surfaces 34, 36 become more prone to wear. Further, load carrying cords within the belt 12 tend to stretch. Adjustment of the belt tension through change in the spacing between the pulleys 16, 18 may then be necessary, possibly on a frequent basis. To accommodate this adjustment, the pulleys and supporting structure therefor have to be made strong and durable, which potentially increases the complexity and the cost of the overall system.
Another problem with conventional, toothed conveying belts is that the rubber underlying the cloth coveting layer is commonly exposed through openings defined between the warp and weft of the cloth layer. The pulleys 16, 18, 24, 26 may directly contact the rubber on the belts 12, 14 through these openings, and as a result abrade the rubber to produce rubber dust particles. This rubber dust may migrate between the belts 12, 14 in the region 38 and may contact and stain the articles 40 that are conveyed.


A loop picker and method of making same are provided wherein such picker has a body provided with a picker stick receiving passage extending therethrough and a forward block, and the block and body are comprised of a single strip of laminated fabric consisting of a forward portion and a trailing portion with the trailing portion being disposed in wound relation and having an innermost turn which defines the major portion of the inside surface of the passage.

1. Field of the Invention
This invention relates to a so-called loom or loop picker employed in the weaving art.
2. Prior Art Statement
Many looms utilized in the weaving industry utilize a freely traveling shuttle to carry each weft thread transversely to warp threads to define a woven fabric and it is common practice to impart motion to such a shuttle using a so-called loop picker. Each loop picker generally is attached to the end of a picker stick and such stick is activated by the loom so as to allow the loop picker to absorb the impact of the oncoming shuttle and immediately thereafter to propel the shuttle with sufficient force to send same in an opposite direction.
In a weaving operation of this type there is repeated impact of the shuttle against each loop picker causing wear thereof. Accordingly, it is necessary to routinely replace each picker whereby it is desirable to keep the cost of each picker at a minimum without sacrificing its wear and impact absorbing characteristics.
Present loop pickers are generally comprised of a so-called forward block and a main body which has a picker stick receiving passage therethrough and various constructions have been proposed heretofore in an effort to improve the operating characteristics of such pickers. Examples of loop picker constructions are presented in the following United States patents:
(1) U.S. Pat. No. 4,130,142 PA1 (2) U.S. Pat. No. 2,389,952 PA1 (3) U.S. Pat. No. 2,172,921
It appears that the loop picker of item (1) has a forward block and a main body made of a plurality of pieces of fabric and uses a so-called triaxial fabric for improved wear.
It appears that the loop picker of item (2) has a picker stick receiving passage defined by the edges of a plurality of turns of material and requires so-called tubular and wedge-shaped components in order to maintain the structural integrity of the main body through which the picker stick is received.
It appears that the loop picker of item (3) has a forward block and a main body each consisting of a plurality of pieces of fabric.


A braking system for an autonomous vehicle includes a brake device that is configured to brake a vehicle wheel. A first control system includes a first pump fluidly connected to the brake device via a hydraulic circuit. A second control system includes a second pump fluidly connected to the brake device via the hydraulic circuit. The second pump is fluidly connected in parallel with the first pump. A controller is in communication with the first and second control systems. The controller is configured to detect a fault in the first control system. The controller is configured to command the second pump to pressurize the hydraulic circuit in response to the failure.

This disclosure relates to an automotive vehicle hydraulic braking system that is electronically controlled to decelerate and stop a vehicle via a pump. The braking system also enables safety features such as anti-lock braking and stability control.
Vehicles that can be driven autonomously are able to stop themselves when their onboard sensors determine that the vehicle needs to slow or stop. Thus, driver input or assistance is not required to stop the vehicle. Typically, vehicle brake systems include a brake caliper or similar braking device associated with each vehicle wheel. Pressurized hydraulic fluid is provided to each braking device to selectively arrest rotation of the associated vehicle wheel. The pressurized fluid is provided to the braking devices through various valves and hydraulic lines. A loss of fluid pressure can adversely affect operation of the braking system.

Pedalless electronically controlled hydraulic braking system with redundant pump


A flame resistant polymer composition comprising: (A) 100 parts by weight of a mixture which comprises 1-99 wt % of (a-1) an olefin polymer and 1-99 wt % of (a-2) a hydrogenated conjugated diene polymer in which 80% or more of double bonds of the conjugated diene are saturated or (a-3) a random copolymer of ethylene and xcex1-olefin having 3-10 carbon atoms, or both (a-2) and (a-3); and (B) 5 parts by weight or more of an inorganic flame retardant. The composition has excellent flame resistance, is free from production of toxic gas and environmental pollutant substances, and exhibits superior well-balanced characteristics such as molding processability, tensile strength, pliability (anti-whitening on bending), flexing resistance, and flexibility. The composition is useful as an electric wire coating material for interconnect wiring in equipment or harnesses for vehicles, and as industrial materials for insulating tapes.

1. Field of the Invention
The present invention relates to a flame resistance polymer composition. More particularly, the present invention relates to a flame resistant polymer composition having excellent flame resistance; free from production of toxic gas such as halogen gas and the like when burnt; free from environmental pollutant substances such as phosphorus, lead, and the like; exhibiting superior well-balanced characteristics such as molding processability, tensile strength, pliability (anti-whitening on folding), flexing resistance, flexibility, and the like; and useful for variety of applications such as electric wire coating materials for interconnect wiring in equipment or harnesses for vehicles, industrial materials for insulating tapes, and the like.
2. Description of the Background Art
Owing to excellent physical and chemical properties, polyolefin-based polymers (resins) are fabricated into films, sheets, pipes, containers, electric wires, cables and the like by means of various methods such as extrusion molding, injection molding, and the like, and are used as household utensils and industrial materials. Because these polyolefin resins are easily flammable, various methods for making the resins flame resistant have been disclosed. In a most common method known in the art, a halogen-containing organic flame retardant is used together with polyolefin resins. Although the use of a small amount of such a flame retardant exhibits an excellent flame resistant effect, the flame retardant has a problem of generating corrosive and toxic gas when burnt.
More recently, a flame resistant propylene resin composition comprising no halogen-containing organic flame retardant has been disclosed (Japanese Patent Application Laid-open No. 263851/1990). However, because this composition contains a phosphorus flame retardant which exhibits hygroscopic properties, the composition requires a measure for preventing bleed-out. Although a certain effect of bleed-out prevention can be attained by the addition of an olefinic rubber and a silane coupling agent, the resulting composition is not necessarily satisfactory from the viewpoint of characteristics such as pliability, flexibility, and the like, as well as from the viewpoint of environmental harmonization.
Another example is a flame resistant polypropylene composition comprising propylene homopolymer, ethylene-propylene copolymer rubber, bis(2,3-dibromopropyl)ether of tetrabromobisphenol S, and antimony trioxide (Japanese Patent Application Laid-open No. 183337/1981). However, because bis(2,3-dibromopropyl)ether of tetrabromobisphenol S which is used in this composition as a flame retardant is a suspected environmental hormone, the composition is not necessarily satisfactory from the viewpoint of environmental harmonization. In addition, although the composition exhibits improved impact strength due to the use of an ethylene-propylene copolymer rubber, the flexibility which is required for wiring and fabrication when the composition is used as an electric wire coating material is not necessarily satisfactory.
Furthermore, a method of using a hydrated inorganic metal compound such as aluminum hydroxide or magnesium hydroxide as a non-pollutant and environmentally harmonious flame retardant has been disclosed (for instance, Japanese Patent Application Laid-open No. 279736/1998). However, a large amount of such a hydrated inorganic metal compound must be added to a flame resistance composition to ensure adequately high flame resistance. This not only results in decrease in the mechanical properties, particularly tensile strength, but also impairs molding processability.
The present invention has been achieved in view of this situation and has an objective of providing a flame resistant polymer composition having excellent flame resistance; free from production of toxic gas such as halogen gas and the like when burnt; free from environmental pollutant substances such as phosphorus, lead, and the like; exhibiting superior well-balanced characteristics such as molding processability, tensile strength, pliability (anti-whitening on folding), flexing resistance, flexibility, and the like; and useful for variety of applications such as electric wire coating materials for interconnect wiring in equipment or harnesses for vehicles, industrial materials for insulating tapes, and the like.
As a result of extensive studies, the present inventors have found that a flame resistant polymer composition generating no toxic gas when burnt, being free from environmentally pollutant substances, and satisfying all of the above characteristics can be obtained by a resin composition comprising (A) 100 parts by weight of a mixture which comprises a polyolefin-based polymer and a specific hydrogenated conjugated diene polymer and/or a random copolymer of ethylene and xcex1-olefin having 3-10 carbon atoms, and (B) 5 parts by weight or more of an inorganic flame retardant. This finding has led to the completion of the present invention. Specifically, the following flame resistance polymer compositions are provided according to the present invention.
(1) A flame resistant polymer composition comprising: (A) 100 parts by weight of a mixture which comprises 1-99 wt % of (a-1) an olefin polymer and 1-99 wt % of (a-2) a hydrogenated conjugated diene polymer in which 80% or more of double bonds of the conjugated diene are saturated or (a-3) a random copolymer of ethylene and xcex1-olefin having 3-10 carbon atoms, or both (a-2) and (a-3); and (B) 5 parts by weight or more of an inorganic flame retardant.
(2) The flame resistant polymer composition described in (1) above, wherein the olefin polymer (a-1) is a mixture of a non-modified polyolefin and a modified polyolefin containing a functional group.
(3) The flame resistant polymer composition described in (2) above, wherein the content of the modified polyolefin in the mixture is 5-150 parts by weight for 100 parts by weight of the non-modified polyolefin.
(4) The flame resistant polymer composition described in (2) above, wherein the functional group in the modified polyolefin is at least one group selected from the group consisting of an acid anhydride group, carboxyl group, hydroxyl group, amino group, isocyanate group, and epoxy group.
(5) The flame resistant polymer composition described in (1) above, wherein the content of side chain vinyl bond of the conjugated diene portion before hydrogenation in the hydrogenated conjugated diene polymer (a-2) in component (A) is 55 wt % or more.
(6) The flame resistant polymer composition described in (1) above, wherein the random copolymer of ethylene and xcex1-olefin having 3-10 carbon atoms (a-3) in component (A) is a random copolymer of ethylene and 1-butene or a random copolymer of ethylene and 1-octene, or both.
(7) The flame resistant polymer composition described in (1) above, wherein the inorganic flame retardant (B) comprises magnesium hydroxide or aluminum hydroxide, or both.
(8) The flame resistant polymer composition described in (2) above, wherein the surface of the inorganic flame retardant (B) is treated with a silane coupling agent.
(9) The flame resistant polymer composition described in (7) above, wherein the surface of the inorganic flame retardant (B) is treated with a silane coupling agent.
Other objects, features and advantages of the invention will hereinafter become more readily apparent from the following description.
The flame resistance polymer composition of the present invention will now be described in more detail by way of embodiments.
The flame resistant polymer composition of the present invention comprises (A) 100 parts by weight of a mixture which comprises 1-99 wt % of (a-1) a polyolefin-based polymer and 1-99 wt % of (a-2) a hydrogenated conjugated diene polymer in which 80% or more of double bonds of the conjugated diene are saturated or (a-3) a random copolymer of ethylene and xcex1-olefin having 3-10 carbon atoms, or both (a-2) and (a-3) (hereinafter may be called xe2x80x9cMixture (A)xe2x80x9d), and (B) 5 parts by weight or more of an inorganic flame retardant (hereinafter may be called xe2x80x9cinorganic flame retardant (B)xe2x80x9d).
Each components for the composition will now be described in more detail.
1. Mixture (A)
The mixture (A) used in the present invention comprises 1-99 wt % of (a-1) a polyolefin-based polymer (hereinafter may be called xe2x80x9cpolyolefin-based polymer (a-1)xe2x80x9d) and 1-99 wt % of (a-2) a hydrogenated conjugated diene polymer in which 80% or more of double bonds of the conjugated diene portion are saturated (hereinafter may be called xe2x80x9chydrogenated conjugated diene polymer (a-2)xe2x80x9d) and/or (a-3) a random copolymer of ethylene and xcex1-olefin having 3-10 carbon atoms (hereinafter may be called xe2x80x9cethylene and xcex1-olefin random copolymer (a-3)xe2x80x9d).
(1) Polyolefin-based Polymer (a-1)
The polyolefin-based polymer (a-1) used in the present invention is a crystalline polyolefin resin (polymer) which can be obtained by the polymerization of one or more types of monoolefins by either the high pressure polymerization method or low pressure polymerization method. Particularly preferable polyolefin resins are polyethylene, polypropylene, and polybutene-1. The polyolefin resin may be either a homopolymer or a copolymer which is produced by the copolymerization of a main monomer and other monomers shown below.
Given as examples of copolymerizable monomers are linear xcex1-olefins such as ethylene (excluding the case where the main polymer is polyethylene), propylene (excluding the case where the main polymer is polypropylene), butene-1 (excluding the case where the main polymer is polybutene-1), pentene-1, hexene-1, heptene-1, and octene-1; branched xcex1-olefins such as 4-methyl pentene-1,2-methylpropene-1, 3-methylpentene-1,5-methylhexene-1,4-methylhexene-1, and 4,4-dimethylpentene-1; and other monomers copolymerizable with these xcex1-olefins. The amount of these copolymerizable monomers is preferably 20 wt % or less, and more preferably 10 wt % or less. There is no specific limitations to the manner of copolymerization. Random polymerization, block polymerization, graft polymerization, or a mixed-type of these manners of polymerization may be acceptable.
Propylene-ethylene copolymer, propylene-butene-1 copolymer, butene-1-ethylene copolymer, propylene-ethylene-butene-1 copolymer, and the like can be given as preferable copolymers used as the polyolefin-based polymer (a-1). These polyolefin-based polymers may be used either individually or in combinations of two or more.
Either a non-modified polyolefin-based polymer or a modified polyolefin-based polymer which is modified with at least one functional group selected from the group consisting of an acid anhydride group, carboxyl group, hydroxyl group, amino group, isocyanate group, and epoxy group, or a mixture of the non-modified polyolefin-based polymer and modified polyolefin-based polymer can be used as the polyolefin-based polymer (a-1). When a mixture is used, a mixture containing 5-150 parts by weight of a modified polyolefin-based polymer for 100 parts by weight of a non-modified polyolefin-based polymer is preferable. If less than 5 parts by weight, the effect on improvement in the mechanical strength may be insufficient; if more than 150 parts by weight, tensile elongation may be impaired.
The amount of polyolefin-based polymer (a-1) added to the mixture (A) is 1-99 wt %, and preferably 20-80 wt %. If less than 1 wt %, the mechanical strength and heat resistance decreases; if more than 99 wt %, tensile elongation and flexibility is impaired.
(2) Hydrogenated Conjugated Diene Polymer (a-2)
Given as examples of hydrogenated conjugated diene polymer (a-2) used in the present invention are hydrogenated products of diene polymers such as a homopolymer of a conjugated diene, a random copolymer of a conjugated diene and an aromatic vinyl compound, a block copolymer which consists of polymer blocks of an aromatic vinyl compound and polymer blocks of a conjugated diene compound, a block copolymer which consists of polymer blocks of an aromatic vinyl compound and random copolymer blocks of a conjugated diene and an aromatic vinyl compound, a block copolymer which consists of polymer blocks of a conjugated diene compound and copolymer blocks of a conjugated diene and an aromatic vinyl compound, a block copolymer which consists of polymer blocks of a conjugated diene compound and a taper-shaped blocks consisting of an aromatic vinyl compound and a conjugated diene compound in which the aromatic vinyl compound gradually increases, a block copolymer which consists of random copolymer blocks of a conjugated diene and an aromatic vinyl compound and a taper-shaped blocks consisting of an aromatic vinyl compound and a conjugated diene compound in which the aromatic vinyl compound gradually increases, a block copolymer which consists of polybutadiene blocks containing 30 wt % or less side chain vinyl bonds and polymer blocks of a conjugated diene compound containing 30 wt % or more side chain vinyl bonds, and the like. The above polymers before hydrogenation may be hereinafter called xe2x80x9cunhydrogenated polymersxe2x80x9d.
Although there is no limitations to the amount of side chain vinyl bonds in the hydrogenated conjugated diene polymer (a-2) before hydrogenation, which is the ratio of 1,2-vinyl bonds and 3,4-vinyl bonds in the conjugated diene portion of the unhydrogenated polymer, such an amount is preferably 55 wt % or more. If less than 55 wt %, the effect on improvement in the whitening on folding may be insufficient.
The hydrogenated conjugated diene polymer (a-2) may be modified by a functional group. Specifically, a diene polymer may be modified with at least one group selected from the group consisting of an acid anhydride group, carboxyl group, hydroxyl group, amino group, isocyanate group, and epoxy group.
The ratio of a conjugated diene compound and an aromatic vinyl compound which form the unhydrogenated polymer is preferably 95:5-40:60, and more preferably 93:7-50:50.
Given as examples of conjugated diene compounds used for the hydrogenated conjugated diene polymer (a-2) are 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene, and the like. Among these, 1,3-butadiene, isoprene, and 1,3-pentadiene, particularly 1,3-butadiene and isoprene, are preferable to obtain hydrogenated conjugated diene polymers which are industrially usable and have excellent properties. As aromatic vinyl compounds, styrene, xcex1-methylstyrene, xcex1-methylstyrene, t-butylstyrene, divinylbenzene, N,N-dimethyl-p-aminoethylstyrene, N,N-diethyl-p-aminoethyl styrene, vinyl pyridine, and the like can be given. Among these, styrene and xcex1-methylstyrene are preferred.
The above unhydrogenated polymer may be a polymer of which the polymer molecular chain is extended or branched via a coupling residue by using a coupling agent.
Given as examples of coupling agents are diethyl adipic acid, divinylbenzene, methyldichlorosilane, silicon tetrachloride, butyltrichlosilicate, tetrachlorostannate, butyltrichlorostannate, dimethylchlorosilicate, tetrachlorogermanium, 1,2-dibromoethane, 1,4-chloromethylbenzene, bis(trichlorosilyl)ethane, epoxidated linseed oil, tolylenediisocyanate, 1,2,4-benzenetriisocyanate, and the like.
A hydrogenated product of two or more unhydrogenated polymers may also be used as a hydrogenated conjugated diene polymer (a-2). In addition, a blend of two or more hydrogenated conjugated diene polymers can also be used.
Such a hydrogenated conjugated diene polymer (a-2) is a hydrogenation product of a polymer of which the major polymerizable component is a conjugated diene compound, and 80% or more, preferably 90% or more double bonds in the conjugated diene portion has been saturated. If the proportion of the hydrogenation is less than 80%, weather resistance and the like are impaired.
A preferable number average molecular weight of the hydrogenated conjugated diene polymer (a-2) is in the range from 10,000 to 700,000, and more preferably from 50,000 to 600,000. If less than 10,000, the hydrogenated conjugated diene polymer is easily blocked when pelletized and the product obtained by blending with the polyolefin-based polymer (a-1) may have lowered mechanical strength. If more than 700,000, flowability, processability, and appearance of molded products may be inferior.
Such a hydrogenated conjugated diene polymer (a-2) can be obtained by the methods disclosed, for example, in Japanese Patent Application Laid-open No. 72512/1991 (page 4, upper right column, line 13 to page 6, lower left column, line 1), Japanese Patent Application Laid-open No. 271325/1993 (page 3, left column, line 42 to page 7, right column, line 19), and Japanese Patent Application Laid-open No. 271327/1993 (page 3, left column, line 36 to page 7, right column, line 31).
The amount of hydrogenated conjugated diene polymer (a-2) added to the mixture (A) is 1-99 wt %, and preferably 20-80 wt %. If less than 1 wt %, tensile elongation and flexibility will be impaired; and if more than 99 wt %, mechanical strength and heat resistance decrease. When use in combination with ethylene-xcex1-olefin random copolymer (a-3) which is hereinafter discussed, the total amount of the hydrogenated conjugated diene polymer (a-2) and ethylene-xcex1-olefin random copolymer (a-3) is 1-99 wt %, and preferably 20-80 wt %.
(3) Ethylene-xcex1-olefin Random Copolymer (a-3)
The ethylene-xcex1-olefin random copolymer (a-3) used in the present invention has an ethylene content preferably in the range of 35-85 wt %, and more preferably 40-85 wt %. If less than 35 wt %, tensile characteristics of the resultant flame resistance polymer composition may be lowered; if more than 85 wt %, flexing resistance may be impaired. In addition, the ethylene-xcex1-olefin random copolymer (a-3) has a melting point peak measured by a differential scanning calorimeter (DSC) of preferably 100xc2x0 C. or less, and more preferably 95xc2x0 C. or less. If higher than 100xc2x0 C., the flexing resistance of the flame resistance polymer composition of the present invention may be impaired.
The xcex1-olefin component in the copolymer has carbon atom in the range from 3 to 10. The carbon atom number is more preferably from 4 to 10 to ensure excellent tensile strength and tensile elongation.
The ethylene-xcex1-olefin random copolymer (a-3) may be a modified ethylene-xcex1-olefin random copolymer which contain a functional group. At least one group selected from the group consisting of an acid anhydride group, carboxyl group, hydroxyl group, amino group, isocyanate group, and epoxy group can be used as such a functional group. The modified ethylene-xcex1-olefin random copolymer can be manufactured using the same method as used for manufacturing the modified polyolefin-based polymer.
Propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-hexadodecene, 4-methyl-1-pentene, and the like can be given as xcex1-olefins which form the ethylene-xcex1-olefin random copolymer (a-3). Of these, 1-butene and 1-octene are preferable.
A random copolymer of ethylene and 1-butene and a random copolymer of ethylene and 1-octene can be given as preferable examples of the ethylene-xcex1-olefin random copolymer (a-3).
If required, the ethylene-xcex1-olefin random copolymer (a-3) may be a copolymer with other polymerizable monomers insofar as the characteristics of the flame resistance polymer composition of the present invention are not adversely affected.
The following compounds can be given as examples of such other polymerizable monomers: vinyl compounds such as styrene, vinyl cyclopentene, vinyl cyclohexane, and vinyl norbornene; vinyl esters such as vinyl acetate; unsaturated organic acids or their anhydrides such as (meth)acrylic acid and maleic anhydride; and non-conjugated polyenes such as 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylenenorbornene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-methylene-2-norbornene, 5-isopropyldene-2-norbornene, 6-chloromethyl-5-iso-propenyl-2-norbornene, 2,3-diisopropyldene-5-norbornene, 2-ethylidene-3-isopropyldene-5-norbornene, 2-propenyl-2,2-norbornadiene, and the like.
The ethylene-xcex1-olefin random copolymer (a-3) may contain recurring units derived from such other polymerizable monomers in the amount of 10 mol % or less, preferably 5 mol % or less, and more preferably 3 mol % or less, of the total recurring units.
The ethylene-xcex1-olefin random copolymer (a-3) may be a single ethylene-xcex1-olefin random copolymer or may be a mixture of two or more ethylene-xcex1-olefin random copolymers.
A melt flow rate (MRF) at a temperature of 230xc2x0 C. and a load of 2.16 kg of the ethylene-xcex1-olefin random copolymer (a-3) is preferably from 0.01 to 100 g/10 minutes, and more preferably from 0.05 to 50 g/10 minutes. If the MFR is more than 100 g/10 minutes, Mechanical strength of the resulting flame resistance polymer composition of the present invention may be impaired; if less than 0.05 g/10 minutes, flowability, processability, and appearance of molded products may be inferior.
The amount of the ethylene-xcex1-olefin random copolymer (a-3) added to the mixture (A) is 1-99 wt %, and preferably 20-80 wt %. If less than 1 wt %, tensile elongation and flexibility will be impaired; and if more than 99 wt %, mechanical strength and heat resistance decrease. When used in combination with a hydrogenated conjugated diene polymer (a-2), the total amount of the hydrogenated conjugated diene polymer (a-2) and the ethylene-xcex1-olefin random copolymer (a-3) in the mixture (A) is 1-99 wt %, and preferably 20-80 wt %.
2. Inorganic Flame Retardant (B)
Aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, basic magnesium carbonate, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, hydrated tin oxidize, hydrated inorganic metal compound such as borax, red phosphorus, and the like can be given as examples of inorganic flame retardant (B). Among these, magnesium hydroxide, an aluminum hydroxide are desirable. These inorganic flame retardants (B) may be used either individually or in combination of two or more.
The surface of the inorganic flame retardant (B) used in the present invention may be treated with a fatty acid such as stearic acid, oleic acid, or palmitic acid, or a metal salt thereof; paraffin, wax, polyethylene wax, or a modified product thereof, an organometallic compound such as an organic borate or organic titanate; or a silane coupling agent. When the polyolefin-based polymer is a mixture of a non-modified polyolefin and a modified polyolefin containing a functional group, the use of an inorganic flame retardant (B) of which the surface is treated with a silane coupling agent is particularly preferred due to outstanding improvement in the tensile strength of the resulting composition.
As required, an ammonium polyphosphate-type flame retardant, a phosphate-type flame retardant, a silicone compound, quartz, and the like may be used to increase the flame resisting effect of the inorganic flame retardant (B). In addition, a flame retardant adjuvant such as water glass, frit, and the like, as well as silicon nitride staple fiber and the like which can prevent drip may be added.
The amount of inorganic flame retardant (B) used in the composition of the present invention is 5 parts by weight or more, preferably 25 parts by weight or more, and more preferably 50 parts by weight or more, for 100 parts by weight or the mixture (A). If less than 5 parts by weight, no composition exhibiting sufficient flame resistance can be obtained. Although there are no specific upper limits to the amount of inorganic flame retardant (B), 500 parts by weight can be given for example.
As required, the flame resistance polymer composition of the present invention may be cross-linked by a conventional method such as sulfur cross-linking, peroxide cross-linking, metal ion cross-linking, silane cross-linking, resin cross-linking, and the like.
3. Preparation of Flame Resistance Polymer Composition
Conventionally known methods can be used for preparing the flame resistance polymer composition of the present invention without any specific limitations. Examples of such methods include a method of melt-kneading mixtures using a known mixer such as an extruder, Banbury blender, kneading machine, roller, or any combinations of these, a method of dry-blending using an injection molding machine, and the like.
All components for the composition of the present invention may be mixed at one time, or a pre-mixture of any optional components may be prepared first, followed by the addition of remaining components.
The composition of the present invention may be fabricated into practically useful products by conventionally known methods such as extrusion molding, injection molding, two-color injection molding, sandwich molding, hollow mold, compression molding, vacuum forming, rotational molding, powder slash molding, vapor-foam molding, laminate molding, calender molding, blow molding, and the like. As required, the product may be processed by means of foaming, powdering, orientation, adhesion, printing, coating, plating, and the like.
Various optional additives may be added to the composition of the present invention as required. Included in such optional additives are stabilizers such as aging preventives, heat stabilizers, weather resistant agents, metal inactivators, UV absorbers, light stabilizers, and copper inhibitors; antiseptics and antifungal agents; dispersants; plasticizers; foaming agents; foaming adjuvants; coloring agents such as titanium oxide and carbon black; metal powders such as ferrite powder; glass fibers; inorganic fibers such as metal fibers; organic fibers such as carbon fibers and alamide fibers; inorganic whiskers such as composite fibers and potassium titanate whiskers; inorganic fillers such as glass beads, glass balloons, glass flakes, asbestos, mica, calcium carbonate, talc, silica, calcium silicate, hydrotalcite, kaolin, diatom earth, graphite, pumice, ebo powder, cotton flock, cork powder, barium sulfate, fluororesin, polymer beads, and mixtures of these; organic fillers such as polyolefin wax, cellulosic powder, and rubber powder; and low molecular weight polymers.


An AC driven active matrix display device in which image display with enough brightness can be easily achieved while reducing an amplitude range of a pixel electrode potential. The display device 1, 100 or 110 according to the invention comprises two memory circuits (a first memory circuit 40 and a second memory circuit 41) which are connected in series between each pixel electrode 22 and a corresponding signal line 30. Data is written to the first memory circuit in a first period, then the data is transferred from the first memory circuit to the corresponding second memory circuit in a second period. The potential of a counter electrode 23 is switched in the second period between a first potential (VcomH) and a second potential (VcomL).

1. Field of the Invention
The present invention relates to an active matrix display device and more particularly relates to an active matrix liquid crystal display device using digital gray scale. In addition, the invention relates to electronic equipment comprising such a display device.
2. Description of the Related Art
In recent years, as a flat panel display (FPD), an active matrix semiconductor display device leads the market. Above all, an active matrix liquid crystal display device in which liquid crystal is used for display medium (also known as electro-optic modulating layer) is widely used as a display device of electronic equipment such as a personal computer. In the active matrix liquid crystal display device, either analog gray scale in which the brightness of each pixel is continuously changed or digital gray scale in which the brightness of each pixel is discretely changed is used. Analog gray scale is realized, for example, by continuously changing a voltage applied to a liquid crystal cell allocated to each pixel and by continuously changing the light transmissivity of the liquid crystal cell. Area gray scale and time gray scale are included in digital gray scale. In area gray scale, a plurality of liquid crystal cells are allocated to each pixel and the brightness of each pixel is changed in accordance with a combination of liquid crystal cells which transmit light. Meanwhile, in time gray scale, a single liquid crystal cell is allocated to each pixel and the brightness of each pixel is changed by discretely changing light transmitting time of the liquid crystal cell in one frame. In addition, a color display is widely provided by using red (R), green (G) or blue (B) filter for each pixel.
FIG. 13 is a circuit diagram which shows a frame format of a conventional active matrix liquid crystal display device. As shown in FIG. 13, an active matrix liquid crystal display device 200 comprises a pixel matrix portion (also referred to as a liquid crystal display portion) 210, a signal line driver circuit 211, and a scan line driver circuit 212. In recent years, the pixel matrix portion 210, the signal line driver circuit 211, and the scan line driver circuit 212 of the active matrix liquid crystal display device 200 are formed on the same substrate by using low temperature poly-silicon thin film transistors (TFTs). Since such low temperature poly-silicon liquid crystal display device 200 can be easily reduced in size, it is particularly suitable for medium or small sized display panel of portable electronic equipment and the like. Furthermore, as the characteristics of low temperature poly-silicon TFTs are enhanced recently, circuits operated with a low voltage (for example 5V) in the liquid crystal display device 200, such as a CPU 213, a controller 214, a memory (not shown) can be made up of low temperature poly-silicon TFTs as well as the pixel matrix portion 210 and the driver circuits 211 and 212. When low temperature poly-silicon TFTs are used for these low-voltage circuits, it is desirable to shorten the gate length in order to improve frequency characteristics and increase element density. However, in the case of shortening the gate length, short channel effect easily occurs, and the characteristics of TFTs vary easily by the drain voltage. Therefore, it is necessary for instance to make a gate insulating layer as thin as possible in order to suppress the short channel effect. For example, it is preferable that a TFT of 5 V has a gate of 2 μm or less in length and a gate insulating layer of 50 nm or less in thickness.
In the pixel matrix portion 210, a signal line 230 and a scan line 231 are arranged in matrix, and a pixel TFT 242 is disposed at an intersection of the signal line 230 and the scan line 231. For the pixel TFT 242, a field effect transistor (FET) is used in general. The gate, source and drain of each TFT 242 are connected to the corresponding scan line 231, the signal line 230 and a pixel electrode 222, respectively. It is to be noted that the signal line 230 and the scan line 231 are respectively connected to the source and gate of the corresponding TFT 242, thus they may be referred to as a source signal line and a gate signal line, respectively.
A counter electrode 223 is arranged so as to face a plurality of pixel electrodes 222, and a liquid crystal 224 is arranged between the pixel electrodes 222 and the counter electrode 223. |In other words, a liquid crystal cell 221 is composed of the pixel electrode 222, the counter electrode 223 and the liquid crystal 224. It is to be noted that although separate liquid crystals 224 seem to be provided in each pixel electrode 222 in FIG. 13, the liquid crystal 224 is ordinarily used as a single member which extends across a plurality of pixel electrodes 222, as well known to those skilled in the art. The same is equally true for the counter electrode 223.
In general, the liquid crystal cell 221 which is composed of the pixel electrode 222, the counter electrode 223, and the liquid crystal 224 interposed therebetween cannot have large electrostatic capacity. Therefore, a storage capacitor 225 is provided in the vicinity of the pixel electrode 222 in order to store electric charge. Although not shown, the TFT 242 and the pixel electrode 222 in the pixel matrix portion 210, and the driver circuits 211 and 212 are ordinarily provided on the same substrate (also referred to as an active matrix substrate or an element substrate). On the other hand, the counter electrode 223 is provided on another substrate (also referred to as a counter substrate). The liquid crystal 224 is interposed between the two substrates.
When a potential (a selective signal) is applied to the scan line 231 so that a voltage between the gate and source of the TFT 242 exceeds the threshold voltage, the TFT 242 is turned on. Then, the drain and source of the TFT 242 are short circuited. The potential applied to the signal line 230 is transmitted to the pixel electrode 222, and the liquid crystal cell 221 and the storage capacitor 225 are charged in accordance with that potential. When the TFT 242 is turned off, there is no conductivity between the drain and source of the TFT 242. The electric charge stored in the liquid crystal cell 221 and the storage capacitor 225 is held until the TFT 242 is turned on. Light transmissivity of the liquid crystal 224 varies depending on whether a voltage is applied or not. Therefore, the brightness of each liquid crystal cell 221 can vary by controlling a potential Vpix of the pixel electrode 222 and a potential Vcom of the counter electrode 223.
When area gray scale is used in the liquid crystal display device 200, for example two adjacent liquid crystal cells 221 are allocated to one pixel. In such a case, the brightness of the pixel can vary with four levels in accordance with a combination of on/off of the two liquid crystal cells 221 (4-level gray scale). When the number of liquid crystal cells 221 to be allocated to each pixel is increased, the brightness of each pixel can vary with multi-level gray scale. The liquid crystal cells 221 having different areas may be allocated to each pixel. Generally and preferably, when k liquid crystal cells E1, E2, . . . , Ek are allocated to one pixel (that is, the number of indicator bits is k), the areas of each liquid crystal cell E1, E2, . . . , Ek are designed so as to be E1=1×E0, E2=2×E0, . . . , Ek=2(k-1)×E0, when the smallest area of the liquid crystal cell is set as E0. By changing the combination of these areas, the brightness of the pixel can vary with 2k-level gray scale as the brightness corresponding to E0 is the smallest unit. In addition, when one liquid crystal cell 221 is allocated to each pixel, digital gray scale can also be used by discretely changing light transmitting time of the liquid crystal cell 221 in one frame of video signal (time gray scale). In this case, k light transmitting time lengths T1, T2, . . . , Tk (the total of T1 to Tk is less than one frame period) are designed so as to be T1=1×T0, T2=2×T0, . . . , Tk=2(k-1)×T0, when the shortest transmitting time length is set as T0. By changing the combination of these lengths, the brightness of the pixel can vary with 2k-level gray scale as the brightness corresponding to T0 is the smallest unit. It is to be noted that in the case of using time gray scale, one frame period is divided into a plurality of subframe periods (pairs of scan period and fly-back period) in order to scan for selecting light transmitting state or non-light transmitting state of the liquid crystal cell in each light emitting time.
In general, the liquid crystal 224 has hysteresis with respect to an applied voltage. Therefore, when a direct current voltage is applied to the liquid crystal 224 for a long period, deterioration such as image persistence is caused. To prevent such image persistence, an electric field in a reverse direction is applied to the liquid crystal 224 at every predetermined period so that the average of voltages applied to the liquid crystal 224 is zero. This driving method is called the inversion drive. In order to perform the inversion drive, as shown in FIG. 14, the potential Vcom of the counter electrode 223 is kept stable, and the polarity of the potential Vpix applied to the pixel electrode 222 (that is, signal line potential) is reversed at every predetermined period (per frame period, for example) based on the potential Vcom of the counter electrode 223. For instance, when the potential Vcom of the counter electrode 223 is 8 V and the potential Vpix of the pixel electrode 222 oscillates between 3 and 13 V, a voltage applied to the liquid crystal 224 is switched between +5 and −5 V. It is to be noted that such inversion drive can be applied to other display medium having hysteresis with respect to an applied voltage as well as the liquid crystal.
In such a driving method, however, amplitude range of a signal line potential is twice as large as a voltage (absolute value) applied to the liquid crystal 224. Therefore, it is required to increase withstand voltage of the signal line driver circuit 211. Further, the gate potential of each TFT 242 varies depending on the source potential. Accordingly, as amplitude range of the signal line potential applied to the source is increased, amplitude range of the gate potential is also increased (for example, from 0 to 16 V). It is thus necessary to increase withstand voltage of the scan line driver circuit 212 to which the gate is connected. For instance, TFTs used for these driver circuits 211 and 212 have preferably a gate of 5 μm or more in length and a gate insulating layer of 100 nm or more in thickness. Moreover, an LDD structure or a gate overlap LDD structure (GOLD structure) is required, hence the manufacturing cost is increased.
As described above, low-voltage TFTs used for the CPU 213 and the controller 214 have desirably a gate of 2 μm or less in length and a gate insulating layer of 50 nm or less in thickness. However, when using the driving method shown in FIG. 14, such TFTs cannot be used for the driver circuits 211 and 212. Accordingly, it is necessary to fabricate two types of TFTs: high-voltage TFTs used for the driver circuits 211 and 212, and low-voltage TFTs used for the CPU 213 and the controller 214. Different processes are required for fabricating these TFTs, thus manufacturing processes and costs are increased.
Another driving method is described with reference to FIG. 15. The potential Vcom of the counter electrode 223 is switched between a high level common potential VcomH and a low level common potential VcomL per frame period, for example. Then, the signal line potential Vpix applied to the pixel electrode 222 varies depending on the potential Vcom of the counter electrode 223 (called AC drive). By using this driving method, amplitude range of the potential Vpix of the pixel electrode 222 (signal line potential) can be reduced by half (that is, the same as a voltage applied to the liquid crystal 224) as compared with using the inversion drive shown in FIG. 13. Hence, withstand voltage of the scan line driver circuit 212 can be reduced as well as that of the signal line driver circuit 211. Accordingly, withstand voltage of TFTs used for these driver circuits 211 and 212 can also be reduced, which results in a reduction in the manufacturing cost. In such AC drive, distortion of the image caused by switching the potential Vcom of the counter electrode 223 is necessarily reduced as much as possible. In view of the foregoing, it is suggested that the potential Vcom of the counter electrode 223 is switched and scanned (a potential of the pixel electrode 221 is set for all the pixels) during a period in which a light source such as a back light is turned off (Patent Document 1). This driving method allows to reduce withstand voltage of the driver circuits 211 and 212, but has problems as described below.
For example, in the liquid crystal display device 200, the liquid crystal 224 is switched from a transmissive state to a non-transmissive state when a voltage of 5V is applied. The potential Vcom of the counter electrode 223 and the potential Vpix of the signal line 230 are alternately operated with a voltage of 0 and 5 V (that is, VcomL=0 V and VcomH=5 V in FIG. 15). In such a case, when the potential Vcom of the counter electrode is 0 V in a frame, a voltage of 5 V has to be applied to the liquid crystal 224 in order to obtain a black display in one of the liquid crystal cells 221. Accordingly, the potential Vpix of the corresponding signal line (the potential of the pixel electrode 222) has to be at 5 V. As a result, a voltage of 5 V is charged across the corresponding storage capacitor 225. The potential Vcom of the counter electrode 223 is switched to 5 V in the next frame. However, when data of the liquid crystal cell 221 (voltage across the storage capacitor 225) has not been rewritten yet, electric charge stored in the storage capacitor 225 (or voltage across the storage capacitor 225) is stored. Therefore, the voltage across the storage capacitor 225 is added to the potential Vcom of the counter electrode 223, then the potential Vpix of the pixel electrode 222 is raised to 10 V. Accordingly, the pixel electrode 222 and elements connected thereto (including the pixel TFT 242) require a withstand voltage of 10 V or more, and the manufacturing cost is thus increased.
Further, since the light source is turned off during scanning and is turned on after scanning, emitting time of the light source is made shorter especially when the number of pixels is increased and it takes much time to scan. Thus, it is difficult to obtain a display with enough brightness.
It is suggested that instead of the storage capacitor, a memory circuit is provided between each pixel TFT and the corresponding pixel electrode, and either a high level power supply potential or a low level power supply potential is directly supplied to the pixel electrode in accordance with data stored in the memory circuit (Patent Document 2).
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-287708
[Patent Document 2]
Japanese Patent Application Laid-Open No. H07-199157

Active matrix display device and driving method of the same

Semiconductor Energy Laboratory Co., Ltd.