An optical pick-up head for reading writing information from on a magneto-optical record medium including a semiconductor laser, a multi-image plane parallel plate for separating an incident light beam emitted by the semiconductor laser from a return light beam reflected by the optical record medium and dividing the return beam transmitted through and refracted by the multi-image plane parallel plate into a plurality of return light beams, and a signal detecting photodetector receiving a plurality of return light beams, wherein the multi-image plane parallel plate is formed by first and second prisms made of birefringent material and is arranged such that major and minor axes of astigmatism introduced by the plane parallel plate are inclined by 45.degree. with respect to an information track. An optic axis of the first prism is set such that the return beam is separated into ordinary and extraordinary light beams having identical intensities and an optic axis of the second prism is rotated with respect to the optic axis of the first prism. The optical elements are positioned and mounted on a mounting substrate having guide walls formed by a photolithography.

1. Field of the Invention
The present invention relates to an optical pick-up head for use in an optical reading and/or recording apparatus for reading and/or recording information from and/or on an optical information record medium, particularly a magneto-optical record medium. The present invention also relates to an integrated type optical unit for use in the above mentioned optical pick-up head.
2. Related Art Statement
FIG. 1 is a schematic view showing a first known optical pick-up head. The optical pick-up head reads and/or records information from and/or on a magneto-optical record medium. A linearly polarized laser beam emitted by a semiconductor laser such as a laser diode 1 is made incident upon a polarizing beam splitter 2 and a laser beam reflected by a polarizing film 2a provided in a contact surface between prisms is projected by an objective lens 3 onto an information track 4a of an magneto-optical information record medium 4 as a fine spot. The polarizing film 2a of the polarizing beam splitter 2 has a transmissivity of 60-90% for a component vibrating in a direction perpendicular to a plane of the drawing of FIG. 1 (S-polarized beam) and a transmissivity of substantially 100% for a component vibrating in a direction parallel with the plane of the drawing (P-polarized beam). Such a polarizing film 2a may be formed by a multiple coatings of dielectric material films. The linearly polarized laser beam emitted by the semiconductor laser 1 is made incident upon the polarizing film 2a as S-polarized beam.
The laser beam is reflected by the magneto-optical record medium 4 is subjected to the Kerr rotation and its polarizing direction is rotated about an optical axis by .+-..theta..sub.k depending upon information recorded on the record medium. The thus reflected return beam is converged by the objective lens 3 and is made incident again upon the polarizing beam splitter 2 as the converging light beam. Then, the return beam is transmitted through the polarizing film 2a so that the return beam is separated from the incident laser beam. Then, the return beam is made incident upon a multi-image prism 5. The multi-image prism 5 is consisting of a first triangular prism 5a and a second triangular prism 5, each being made of birefringent material. In order to detect an information signal recorded on the magneto-optical record medium 4 by a so-called differential method, an optic axis of the first prism 5a is set to be perpendicular to an optical axis of the return beam and to be inclined by 45.degree. with respect to a direction perpendicular to the plane of the drawing, and an optic axis of the second prism 5b is set to be inclined by 45.degree. with respect to the optic axis of the first primes in, for instance in the direction perpendicular to the plane of the drawing. Therefore, the return beam impinging upon the multi-image prism 5 is divided into substantially three light fluxes. The information signal read out of the optical record medium is denoted as MO signal for sake of simplicity.
The three light fluxes emanating from the multi-image prism 5 are then made incident upon a signal detecting photodetector 6 via a toric lens 7. The toric lens 7 has a function for extending a focal length of the transmitted light as well as a function as a cylindrical lens for introducing astigmatism which is required to detect a focusing error signal (hereinafter the focusing error signal is called FES). As illustrated in FIG. 2, the signal detecting photodetector 6 comprises three light receiving units 6a, 6b and 6c, and the middle light receiving unit 6b includes four light receiving regions. The MO signal is derived from a comparator 8 producing a difference between outputs of the light receiving units 6a and 6c, and the FES is obtained from a comparator 9 producing a difference between a sum of outputs of diagonally aligned light receiving regions of the light receiving unit 6b and a sum of outputs of other diagonally aligned light receiving regions. A tracking error signal (denoted by TES) may be derived by, for instance a push-pull (PP) method.
In Japanese Patent Application Laid-open Publication Kokai Hei 5-314563, there is disclosed a second known optical pick-up head. In this optical pick-up head, in a converged return beam there is arranged a plane parallel plate having an optical anisotropy, said plane parallel plate having a function of separating the return beam from the incident beam, a function of performing the polarizing separation for detecting the MO signal by the differential method, and a function of introducing astigmatism for detecting the FES. Ordinary light and extraordinary light separated by the plane parallel plate are received separately by a signal detecting photodetector.
The above mentioned first known optical pick-up head has the following problems:
(1) The polarizing beam splitter 2 for separating the return light path from the incident light path, the multi-image prism 5 for dividing the return beam into a plurality of light fluxes with the aid of the polarization, and the toric lens 7 for introducing the astigmatism required for detecting the FES are arranged separately from each other, and thus the optical pick-up head could not be made light in weight, small in size and cheap in cost. PA1 (2) The semiconductor laser 1 and signal detecting photodetector 6 which are arranged in conjugate with one another are spatially separated from each other by a large distance, and thus the optical pick-up head is liable to be subjected to temperature variation, secular variation, and others, so that use of the optical head is limited by ambient conditions. In order to mitigate such a drawback, it is required to use a large and expensive housing incorporating the optical elements. PA1 (3) An optical path length of the detecting optical system is increased by a concave lens function of the toric lens 7, so that size of the optical head is prolonged, although adjustment of the signal detecting photodetector 6 becomes easy. PA1 (4) A direction in which the astigmatism for detecting the FES is introduced is in parallel with a track direction in which an information track extends or is perpendicular to the track direction. Therefore, a push-pull signal for detecting the tracking error is leaked into the FES and the focusing servo is liable to be unstable. PA1 (5) The FES is detected only from one of the polarizing split beams, and thus an amplitude of the FES fluctuates due to a birefingency of a substrate of the magneto-optical record medium and an accurate focus servo control could not be performed. PA1 (6) A positioning of the signal detecting photodetector is difficult. PA1 (7) In the first known optical pick-up head shown in FIGS. 1 and 2, the number of optical elements is large, so that a total error represented by a sum of errors of respective optical elements becomes very large. In order to absorb these errors, the photodetector 6 has to be adjusted in xyz axes or the photodetector has to be adjusted in xy axes and the toric lens 7 has to be adjusted in z axis. In this manner, it is required to perform a very cumbersome three axis adjustment. In this case, the xy axis adjustment could not be independent from the z axis adjustment, so that a number of adjusting steps are increased. PA1 (8) Moreover, since the number of optical elements provided within a portion 10 surrounded by a chain line in FIG. 1 is large, an actual size of the portion 10 amounts to several tens to several hundreds millimeters by considering a space for providing adjusting mechanisms. Therefore, it is required an expensive housing consisting of a several blocks and complicated workings are required in order to manufacture these blocks. PA1 a semiconductor laser emitting a linearly polarized light flux; PA1 an objective lens projecting said light flux onto a magneto-optical record medium as a fine spot; PA1 a multi-image plane parallel plate arranged between said semiconductor laser and the objective lens in a converged return light flux reflected by said record medium, reflecting the linearly polarized light flux emitted by said semiconductor laser toward said objective lens and transmitting and refracting said return light flux to introduce astigmatism in the return light flux and to perform a polarizing beam splitting, said multi-image plane parallel plate including a first triangular prism and a second triangular prism which are made of birefringent material and are joined with each other; and PA1 a signal detecting photodetector receiving a plurality of light fluxes emanating from said multi-image plane parallel plate, detecting an information signal from outputs corresponding to mutually orthogonally polarized light components, and detecting a focusing error signal from outputs corresponding to ordinary and extraordinary light components; wherein said multi-image plane parallel plate is arranged such that directions of major and minor axes of said astigmatism are inclined by 45 degrees with respect to a track direction in which an information track on the magneto-optical record medium extends, an optic axis of said first triangular prism is set such that said return light flux is divided into the ordinary light and extraordinary light having substantially identical intensities, a polarizing film is provided on a surface of the first triangular prism upon which said linearly polarized light flux and return light beam are made incident, and an optic axis of said second triangular prism is set to be inclined by a predetermined angle with respect to the optic axis of the first triangular prism. PA1 a mounting substrate including a silicon wafer having a (110) uppermost surface and having formed therein upright recesses or upright walls each formed by {111} surfaces; PA1 a semiconductor laser secured to one or more upright recesses or upright walls, positioned at least in a direction of an optical axis of the semiconductor laser and emitting a light beam; PA1 a photodetector secured to one or more upright recesses or upright walls, positioned at least in a direction of an optical axis of the photodetector and receiving a return beam reflected by an optical record medium; and PA1 an optical path separating element secured to one or more upright recesses or upright walls, positioned at least in a direction of an optical axis thereof, directing the light beam emitted by the semiconductor laser toward the optical record medium and directing the return beam toward the photodetector. PA1 a mounting substrate including a silicon wafer having a (100) uppermost surface and having formed therein a plurality of pyramid recesses with {111} side walls; PA1 a semiconductor laser secured to a pyramid recess of the mounting substrate, positioned at least in a direction of an optical axis of the semiconductor laser and emitting a light beam; PA1 a photodetector secured to a pyramid recess, positioned at least in a direction of an optical axis of the photodetector and receiving a return beam reflected by an optical record medium; and PA1 an optical path separating element secured to a pyramid recess, positioned at least in a direction of an optical axis thereof, directing the light beam emitted by the semiconductor laser toward the optical record medium and directing the return beam toward the photodetector. PA1 a mounting substrate including an uppermost polyimide film having a plurality of upright recesses; PA1 a semiconductor laser secured to one of said upright recesses of the mounting substrate, positioned at least in a direction of an optical axis of the semiconductor laser and emitting a light beam; PA1 a photodetector secured to another one of said upright recesses of the mounting substrate, positioned at least in a direction of an optical axis of the photodetector and receiving a return beam reflected by the optical record medium; and PA1 an optical path separating element secured to another one of said upright recesses of the mounting substrate, positioned at least in a direction of an optical axis of the optical path separating element, directing the light beam emitted by the semiconductor laser toward the optical record medium and directing the return beam reflected by the optical record medium toward the photodetector. PA1 a mounting substrate including a silicon wafer having a (110) uppermost surface and having formed therein a plurality of upright walls formed by {111} surfaces; PA1 a semiconductor laser secured to one or more (111) upright walls and emitting a light beam; PA1 a photodetector secured to one or more (111) upright walls different from said one or more upright walls to which said semiconductor laser is secured, and receiving a return beam reflected by the optical record medium; and PA1 an optical path separating element secured to at least two convex corners of upright walls different from the upright walls to which said semiconductor laser and photodetector are secured, a rotation of said optical path separating element being inhibited by said at least two upright walls, directing the light beam emitted by the semiconductor laser toward the optical record medium and directing the return beam reflected by the optical record medium toward the photodetector.
In the second known optical pick-up head, the plane parallel plate having optical anisotropy has all the three functions, i.e. separating the return beam from the incident beam, polarizing beam splitting function and astigmatism introducing function, the above mentioned problems (2) and (3) of the first known optical pick-up head can be mitigated. However, the second known optical pick-up head has the following problems:
In known optical pick-up heads, a housing for accommodating the optical elements is manufactured by a mechanical process by using lathe, miller and NC lathe, and then the optical elements are fixed to the housing by means of screws and adhesive agent. Therefore, the housing is liable to become large and moreover positioning errors of the optical elements could be hardly limited to micron order.
In Japanese Patent Application Laid-open Publications Kokai Sho 62-197931 and 62-283430, there is disclosed a third known optical pick-up head. In this optical pick-up head, on a semiconductor substrate having photo diodes formed therein there are provided a beam splitter and a laser diode to constitute a single integrated body. This optical pick-up head can reduce a cost and a size. Moreover, in Japanese Patent Application Laid-open Publication Kokai Hei 3-44086, there is proposed a laser unit for use in the optical pick-up head. In this laser unit, a laser diode is sealed within a housing in which a collimator lens is provided.
If the above mentioned third known optical pickup head is applied to an infinite optical system using the collimator lens, it is necessary to adjust positions of a substrate on which the beam splitter and laser diode are secured with respect to an optical axis of the collimator lens, and this requires an adjusting mechanism and fixing parts therefor as well as spaces for the these elements. In this manner, although the beam splitter and laser diode are secured to the substrate in which the photo diodes are formed, size and cost of the optical pick-up head could not be reduced sufficiently.
In the laser unit described in the above mentioned Japanese Patent Application Laid-open Publication Kokai Hei 3-44086, the collimator lens is secured to the housing in such a manner that an outer periphery of the collimator lens is cemented to an inner wall of a circular opening formed in the housing. Therefore, the collimator lens could not be moved in a direction perpendicular to the optical axis of the laser diode, so that an adjustment of a propagating direction of a collimated beam is limited. Further, in this laser unit, a distance between the laser diode and the collimator lens could not be determined accurately, so that an accurately collimated laser beam has to be obtained by changing an oscillation frequency of the laser diode by adjusting an injection current therefor. Therefore, the laser unit could not be applied to an optical pick-up head in which a power of the laser beam is changed between the reading and the recording by adjusting the injection current to the laser diode. Moreover, the semiconductor laser whose wavelength is varied in accordance with the injection current could not be manufactured at a large scale at present and is expensive.

Optical pick-up head and integrated type optical unit for use in optical pick-up head


Method and device for digestion of sludge, sludge being transferred stepwise to closed containers (10A, 10B) and gas generated during the digestion process being transferred from said containers (10A, 10B). The sludge is transferred to a first closed space (11A) in a first container (10A) for a first digestion period, and is then after a predetermined period transferred to a second closed space (11B ) in a second container (10B) for a second digestion period. During said first digestion period as well as during said second digestion period the sludge is repeatedly put into movement by tipping said containers (10A, 10B), the flow direction of said sludge being changed to redirect surface material of the sludge to bottom material by the movement of the sludge. Each of said containers (10A, 10B) is provided with an inlet (12) for sludge and a first outlet (13) for gas generated during the digestion period. Said first closed space (11A) and said second closed space (11B) are connected to each other through a valve (16), and internally they are provided with flow redirectors (22) so as to improve the homogenisation of the Said containers (10A, 10B) are designed to be tipped between two positions.

In many countries there is a short supply of water and it is costly to construct sewers of an appropriate slope to use water as a transporting medium. By choosing to have an early separation the transport is facilitated and the need of water is reduced. A lower amount of water will also facilitate an efficient treatment of sludge. By constructing a separating device as close as possible to the origin of the waste water the problems discussed above can be reduced and the quality of the sludge improved.
Such an early separation is described in SE 9000921 according to which a sewer system having a plurality of separating tanks is used.
To use digestion of sludge for reducing biological material and odor in the treatment of sludge is well known from a plurality of patent documents. Such use is described e.g. in SE 7801404 and SE 7909320.
Also DE-A1-3 230 010 disclosed a device for digestion of sludge. A tank divided into four chambers is used for the digestion. The tank can be tipped between two positions. The digestion process takes part in a bottom layer and some sludge will float up to the surface where it is digested only slowly or not digested at all. Biogas which is formed during the process presses liquid from one chamber into the second, and the tank is tipped from slightly tipping in one direction to slightly tipping in another direction. Valves within the tank are used for the passage of gas in an appropriate way. According to the patent document the steering of sludge should be slow and without turbulence, and a plurality of rotatable flaps and similar devices are used. The reliability in operation of the system described in DE-A1-3 230 010 tends to be low as a result of using movable parts and valves within the tank.
Problems that are not considered completely presently when devices for the digestion of sludge are used are e.g. odor and extended required digestion periods resulting in high demands on large sludge drying beds and on a high quality of the sludge and also to the concentration to large plants.
An object of the present invention is to essentially solve the problems discussed above such as large volumes, odor, low quality of sludge and specially made material. Another object is to accomplish a reliable device.
The object has been obtained by including in the invention the features of claim 1.


Optical devices extending the free spectral range and tunability of, and enabling hitless switching of, integrated optical filters suitable for add-drop filters. Devices include (i) a splitter device configured to split an input spectrum among a plurality of output ports, and a combiner device configured to combine at least a portion of the split input spectrum into a single output port, splitter and combiner having respective first and second input and output ports, and a respective transfer matrix, the matrix of the combiner being the diagonal transpose of that of the splitter; (ii) a first optical path coupling the first output port of the splitter and the first input port of the combiner; (iii) a second optical path coupling the second output port of the splitter and the second input port of the combiner, wherein the first and second optical paths are configured to introduce, at least at a wavelength of the input spectrum, a relative phase shift of π radians; and (iv) an optical filter coupled to at least one of the first and second optical paths.

Wavelength-division-multiplexed (WDM) optical transmission systems carry multiple wavelength channels simultaneously on a single guiding optical line. Integrated optical circuits, comprising various functional optical components, employ waveguiding structures that can couple light efficiently to and from optical fibers, and offer the possibility of WDM signal processing, such as switching and routing, on a chip in the optical domain. Dynamic reconfiguration of functional optical components that operate on a subset of the used WDM spectrum may be employed to reroute one or more WDM signals around a broken link in the network, to add/drop one or more wavelength channels on a WDM fiber at a network node, or to perform other signal processing operations on a wavelength-selective basis. A device that performs such functions is referred to as a reconfigurable optical add-drop multiplexer (R-OADM), and employs channel add-drop filters.
Optical channel add-drop filters are devices that typically have an input port, at least a drop or add port, a through port, and preferably a further port which, in combination with the drop or add port, forms a pair of add and drop ports, and support narrow passbands covering typically a single wavelength channel. They enable transmission of a signal in the selected wavelength channel within the passband from the input port to the drop port with low loss (preferably less than 3 dB), while suppressing crosstalk from signals in other wavelength channels in the operating wavelength range (OWR) of the filter (preferably by at least 30 dB). All channels outside the filter passband and in the OWR of the filter are transmitted from the input port to the through (or express) port, preferably with much less than 3 dB insertion loss. The selected wavelength channel within the filter passband is preferably fully removed from the input spectrum with preferably over 30-40 dB extinction of the signal remaining in the through port. This high extinction is required to prevent crosstalk with a new signal, incident at the add port, that is inserted into the through port at the selected channel wavelength. Wavelength channel passbands are typically 10-100 GHz wide and are typically spaced by 25-200 GHz as, for example, specified by the International Telecommunications Union (ITU) wavelength grid standards. For 40 GHz wide filters, typically no more than about 20 ps/nm of dispersion is preferably added by the filter to the channels in both the drop port and the through port. In the through port, much less dispersion is preferable because wavelength channels on a ring network may traverse many R-OADMs via the through port before reaching their destination and being dropped. To support cascading often, i.e., at least 5-20 times, lower dispersion values are desirable. Furthermore, it is preferable that any insertion loss and/or dispersion that is introduced by the filter to express channels, i.e., those passing to the through port, be balanced, i.e., as equal as possible among all of the channels.
Preferably, during the dynamic reconfiguration of optical components such as R-OADMs, i.e., of their add-drop filters, that operate on a subset of the WDM spectrum, the data flow on other express wavelength channels in the through port is not interrupted or deteriorated (e.g., by insertion loss or dispersion) during the reconfiguration operation. This is referred to as hitless switching or hitless reconfiguration of the optical component.
It is further desirable that an optical channel add-drop filter be able to process any single WDM channel within its OWR. The OWR of the filter is preferably a wide optical band, e.g., the C-band communication window of 1530-1570 nanometers (nm). It is desired a filter with only one active passband over the operating wavelength range, and thus, for resonant filters, only one resonance within the optical band, i.e., a spacing between adjacent resonances, or free spectral range (FSR), larger than the OWR. A filter whose operating channel wavelength may be dynamically adjusted is referred to as tunable. A wide tuning range for the center wavelength of the filter passband—a tuning range that covers the OWR—is required to enable to access any channel in that range. Finally, the filter reconfiguration process from dropping one wavelength channel to dropping another wavelength channel or a complete off state (not dropping any channels), is preferably hitless, i.e., transparent to the other WDM channels as described.
Integrated optical filters with a single passband over a wide operating wavelength range can be made using optical resonators, for example microring resonators, with a large FSR equal to or larger than the OWR, such that only one resonance lies within the range. Large FSR resonators can be made by making the resonator small in size so that, in traveling-wave resonators like rings, the path length is short and spaces longitudinal resonances further apart spectrally. Small ring resonators have tight bend radii and optical radiation confined and propagating in such a ring tends to experience bending radiation loss, giving rise to a low quality factor, Q. Radiation loss can be reduced to an acceptable level by designing waveguides using high refractive index contrast (HIC) between the waveguide core and cladding, such as SiN (n˜2 near 1550 nm wavelength) or Si (n˜3.5) core, and silica (n˜1.45) or air (n˜1) cladding. In turn, high-index-contrast resonators are small and require fine lithography, can have significant propagation losses due to surface roughness, and their resonant frequency can be very sensitive to small dimensional errors resulting in fabrication. Furthermore, for very large FSRs desired in some applications, it may not be possible to use a sufficiently high index contrast due to lack of practical materials with a high enough index over the wavelength range of interest. Therefore, methods to extend the usable FSR of a filter are desirable.
In the Vernier scheme, two resonators with different FSRs are cascaded such that a passband is obtained only at those wavelengths where both resonators have a resonance. This enables the use of ring resonators, for example, of larger radii and lower index contrast to achieve a particular large FSR. In add-drop filter applications, where the through-port response (relevant to express channels) is of interest, certain such Vernier designs may have excessive dispersion at suppressed resonances and thus destroy the signal modulation in some of the through port channels. Thus, filter FSR extension schemes with tolerable dispersion are of interest.
Furthermore, mechanisms for wavelength tuning of the passband of a filter, such as thermo-optic (TO), electro-optic (EO) or micro-electro-mechanical systems (MEMS)-based tuning, support a certain limited range of wavelength tunability. Moreover, the filter center wavelength is preferably to be well controlled to a fraction of the passband width. When directly tuning a resonator over a wide OWR using one of the aforementioned mechanisms, it is necessary to span the full OWR, and yet simultaneously provide the fine tuning control necessary to support the needed wavelength stability and accuracy. For example, for a 40 gigahertz (GHz)-wide filter passband on a 32 nm (4 terahertz (THz))-wide OWR containing a WDM channel spectrum, one may need better than 4 GHz control on the filter center frequency or one part in 1000 (tolerable resonance frequency error relative to the OWR). Filter architectures that permit wider tuning, more robust control of the tuning mechanism, lower power consumption, higher speed, or a combination thereof are of interest.

Wide free-spectral-range, widely tunable and hitless-switchable optical channel add-drop filters


In modem, modularly structured mobile radio systems, a call between a base station and a mobile subscriber station is to be handed over to a different base station the moment the mobile subscriber station leaves the coverage area of a base station. For this purpose, a switching system providing the route between a fixed network and the base stations is to carry out appropriate switching operations. In order to realise shortest possible dead times caused by interruptions during call handovers from one radio cell to another radio cell, a first and a further base station each comprise switching equipment for inserting a signal (S.sub.k) coming from a switching center into a signal (S.sub.g) going to the switching center.

1. Field of the Invention
The invention relates to a mobile radio system comprising at least a first base station, at least a further base station and at least a switching centre.
The invention further relates to a base station, switching equipment and a detection and control arrangement for such a mobile radio system.
2. Discussion of the Related Art
In a mobile radio system there are provided a plurality of base stations for maintaining radio links to mobile subscriber units. A switching centre also referenced switching system in the following is used for establishing connections to the base stations allocated to the switching system. For a handover, the switching system comprises, for example, means which hand over, as required, a connection between the switching system and a mobile subscriber station existing via a first base station (call handover base station) to a second base station (call take-over base station).
Modem mobile radio systems currently comprise many individual radio cells which have each a limited coverage area. Each cell is supplied with radio signals by a base station, while the transmitter power of the base stations and of the mobile subscriber stations is adapted to the size of a radio cell. In this manner the same radio parameters (for example, frequencies, time slots or codecs) can be used in radio cells which are a specific distance apart, without having to take mutual interference into account.
While a base station is connected to mobile subscriber stations that are located inside its cell via a radio channel, the base stations themselves are connected to switching systems, for example, via cable transmission paths. The switching systems on their part are again connected to at least one fixed network, for example, the public telephone network (PSTN=Public Switched Telephone Network, or ISDN=Integrated Services Digital Network). Via the switching systems a mobile subscriber station can be linked to an arbitrary subscriber of the respective network (mobile originating call), or a subscriber of the respective network to an arbitrary subscriber of the mobile radio network (mobile terminating call). In the case of such a link, this may conventionally relate to a call link, but also to a data link, for example, for a facsimile transmission.
The moment a mobile subscriber station leaves the coverage area of a radio cell assigned thereto, there should be provided that the radio link to the mobile subscriber station is taken over by another radio cell i.e. by another base station. The occurrence of such a change of radio cells may be detected, for example, by measuring the signal field strength, the signal-to-noise ratio, the error probability, the distance between base station and mobile subscriber unit and so on. If such a situation is detected, both the radio link is to be handed over from one base station to the take-over base station and the transmission path between a network subscriber and the handover base station is to be switched to the take-over base station.
In a call handover method which is implemented, for example, in a GSM system, first a free radio channel is to be selected by the take-over base station. This channel is announced to the mobile subscriber station, so that the mobile subscriber station can maintain the radio link along the channel announced thereto. In other systems, for example, in DECT (Digital European Cordless Telecommunication), the selection of the new radio channel is made by the mobile station.
When the mobile station is changed to the new radio channel, also the link in the cabled part of the mobile radio system is to be switched over by appropriately driving the switching systems concerned. Then there is the problem that the radio channel and the switching systems are to be switched over substantially simultaneously, so that no perceivable pauses, for example, caused by clicking sounds, or even longer pauses, occur.
For this purpose, there has also been proposed to build up a conferencing circuit of the mobile subscriber with himself, that is, on the one hand, via the base station that hands over the call and, on the other hand, via the base station that takes over the call, so that there is always a link to the mobile subscriber, irrespective of the instant of switching. The cost of such conferencing circuits, however, is considerable. Furthermore, there is the problem that before the radio channel is switched over, the base station taking over the call, or after the radio channel has been switched over, the base station handing over the call, inserts a noise signal into the radio link that does not yet exist or no longer exists. This is tolerable, it is true, for call links, but, in the case of data links, this may lead to errors that can no longer be corrected.
EP 0 544 457 has disclosed a method for handling a call handover from a first base station to a second base station, in which the link from fixed-network subscriber to switching system is first led via a switch specially provided for the call handover before the radio channels are switched over. In preparation of the call handover, this switch completely establishes the connection path to the call take-over base station via the switching system to which the take-over base station is connected, including rendering the new radio channel available to the take-over base station. After this connection has been established, the handover base station announces to the mobile subscriber station that it is to change to the radio channel of the handover base station. Simultaneously, the switch is given the instruction to switch to the new connection already prepared. Subsequently, the previous connection to the take-over base station can be broken off via the switch.
In a special embodiment in which the (call) data are available as compressed time slot signals, the switch is arranged as a unit for time slot exchange. The advantage of the switch lies in the fact that, prior to the actual call handover, all connections are already prepared, and thus for a switch-over to the network only the time slot signals need to be switched over i.e. exchanged. Once an appropriate control signal has arrived at this switch, the switching may be effected without delay. In this manner the period of time in which the connection to and from the mobile subscriber station is dead is to be smaller than 150 ms.
This switching time may be acceptable for call links. For data transmission, however, a switching time of this order of magnitude is no longer acceptable.

Mobile radio system with improved handover facility


An apparatus for exciting and detecting NQR in a substance containing quadrupole nuclei responsive to the NQR phenomenon. The apparatus includes a coil 15 for irradiating an item that may contain a substance with RF waves to excite NQR in quadrupole nuclei within the substance and for receiving an NQR signal emitted in response thereto. A transmitter unit 10 is provided for producing and transmitting an RF pulse to the probe to create said RF waves. A receiver unit 11 is provided to receive and treat a received signal from said probe for subsequent processing and detection of a said NQR signal therein. A sensing means is included in the apparatus for sensing an extraneous parameter that may influence the detection of the NQR signal from the item to be scanned. A computer 12 is provided for processing the treated received signal to identify a said NQR signal therein, and control the transmitting means and the receiving means in response to said processing means and said sensing means to optimize the excitation and detection of the NQR signal. The sensing means may comprise one or more temperature probes 13, RF antennas 17, metal detectors 18, metal imagers 19, temperature tags 20 and optical or infrared scanners 22 and 23, or any one or combination of these.

The following discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.
NQR has been proposed as an alternative technology for the detection of explosives, narcotics and other illicit substances containing quadrupole nuclei responsive to the NQR phenomenon. Whilst NQR detection technology in theory may be used to detect explosives in items at airports, mail centres and entry points to important buildings such as courthouses etc, in practice, great difficulty has been encountered in designing and producing an NQR scanner that is practicable and reliable to operate in such environments.
An NQR scanner device theoretically brings an item to be scanned, such as luggage, to stop within a coil or near a coil or coils. The computer in control of the device directs the transmitter to irradiate the item being scanned with a burst of radiofrequency (RF) waves, which excite an NQR substance within the item being scanned. After a short period of dead time the receiver detects any very small voltage induced on the coil by relaxing quadrupolar nuclei. The computer then receives and transforms this signal and determines whether this signal exceeds a predetermined threshold level. If the signal does exceed the threshold level an alarm is signalled to the operator.
It has been found, however, that the entire process is dependent upon the physical characteristics of the item being scanned and the surrounding environment. Certain characteristics of the scan item affect the detection capability and the false alarm rate.
One of the major problems that has so far restricted the use of NQR technology is the fact that the NQR frequencies of different NQR substances drift with temperature. The amount of drift is not large (427 Hz/° C. for the 5.2 MHz line of RDX), but is enough to cause problems in measuring small hard to find signals as would be required in a practical NQR scanner. The main problem is that if the temperature of the item is unknown, then the resonant frequency of the NQR substance will also be unknown. Consequently, the item may be irradiated at the incorrect frequency resulting in a missed detection.
To overcome this problem the range of frequencies irradiated can be enlarged by using a lower transmit Q factor, however this would still result in a possible missed detection because a high receive Q factor is usually required to detect such small NQR signals.
An alternative method is to selectively irradiate small sections of the frequency spectrum sequentially so the probability of detection increases. By using this method a range of frequencies corresponding to a range of temperatures can be irradiated maximising the probability of detection. For instance, in an airport scenario for detecting an explosive having NQR nuclei, it may be expected that the range of temperatures encountered may be 0–40° C. Hence by arranging the system to irradiate all frequencies that correspond to that temperature range, the explosive should be detected.
One of the problems with the above method is the fact that it requires the use of sequential pulse sequences, each of which consume valuable time. During airport scanning of baggage, the time allowed for scanning a bag approximately ranges from 6–20 seconds. By scanning to cover a range of temperature of say 10–35° C., as many as 3 or 4 pulse sequences have to be applied so that the explosive is properly irradiated. This method results in an unacceptably long delay, which is unacceptable to the machine operator and passengers alike.
Furthermore, when irradiating the bag with two separate pulse sequences, there is a strong possibility that the explosive will be partially excited on the first sequence, resulting in a weak signal which is not detected, and then partially excited again on the second sequence, which is also not detected, resulting in a missed detection.
Another possibility is to interleave the pulse sequences such that each successive pulse group has one of the 3 or 4 frequencies required. However, the time taken to achieve the same signal sensitivity is still 3 or 4 times longer as compared to a single pulse sequence.
In the process of scanning objects and relying upon RF frequencies for signal detection, NQR scanners invariably encounter the problem of RF interference. The RF interference can be external or internal to the machine. One form of internal interference can emanate from the item being scanned. Items such as mobile phones, toys, video cameras, watches etc all emit RF noise resulting in difficulty in the detection of weak NQR RF signals. Pulse sequences that have been used to overcome magnetoacoustic ringing, may partially counteract this problem, however these techniques cannot fully remove this phenomenon.
A further problem is that the detection of illicit substances containing NQR nuclei encased within metal objects using conventional NQR techniques is difficult. The RF waves generated by an NQR scanner device are generally unable to penetrate metal surfaces due to the eddy current effect. This means that in scanning airport luggage for explosives, it may be possible to pass an explosive in a bag through an NQR scanner and it not be detected by the scanner. This problem makes current NQR scanners deficient in their capability, and is one of the principal reasons as to why no commercially viable NQR scanners have appeared in the market.

Nuclear quadrupole resonance measurements


A CMOS temperature sensor includes a first circuit portion for generating a voltage signal whose value increases with the temperature to be sensed, and a second circuit portion for generating an electric voltage signal whose value decreases with the temperature to be sensed. A comparator is provided as an output stage for comparing the values of both voltage signals. The generator element of the second circuit portion is a vertical bipolar transistor connected in a diode configuration.

The present invention relates to integrated circuits, and, more particularly, to a CMOS temperature sensor adapted for operation over a wide range of supply voltages. For example, the temperature sensor according to the present invention can operate within a range of 1.8 V to 7 V at a current consumption of about 2.8 mA.
Temperature sensors are incorporated in a number of electronic circuits for a variety of purposes. For example, dissipation by integrated circuits exceeding a safe temperature limit needs to be signaled so that the dissipation can be controlled. In addition, the operating temperature range for a particular electronic system may have to be limited.
More particularly, temperature detectors have been used as security arrangements for monitoring the operating temperature of non-volatile EEPROM memories used in Smartcards. Smartcards are plastics cards having an integrated circuit, such as a memory circuit or a microcontroller, embedded therein. These cards are increasing in popularity for a variety of applications, including credit/debit cards, POS cards, telephone cards, access control cards, etc.
Smartcards are to meet strict security requirements, and this has resulted in a constant development of intrusion-defeating arrangements for their improved effectiveness. One possible form of intrusion is to expose the card to a heat source to alter the operation of the integrated circuit contained therein. Many intrusions into smart cards can be attempted by a technique known as differential power analysis (DPA), which is readily understood by one skilled in the art.
Also known is the use of hardware or firmware security arrangements. These arrangements are being regularly designed for improved security. Such arrangements include using advanced 0.35-micron technologies to minimize both the size and the consumption rate of the integrated circuit, as well as relative variations in its operational parameters. When combined with a screening metallization level, this makes DPA attempts less likely to succeed.
Other such security arrangements include using specific operational software for the internal timing of the integrated circuit, whereby high variability is introduced in the operation scans when such operations are carried out. A modular design may also be used which enables the circuit hardware to be quickly modified for immediately counteracting new forms of intrusive attempts.
Yet another security arrangement includes using a series of hardware mechanisms, such as thermal protectors, for example, which enable the resident integrated circuit applications to detect and react as appropriate to the occurrence of any operational conditions which may look like an intrusive attempt or is actually a factual indication of an intrusive attempt.
There is a need to improve resident thermal protectors for an integrated circuit requiring such protection. In general, temperature can be measured in integrated circuits on the basis of a voltage differential DVbe which is proportional to temperature (PTAT), and a voltage value which is proportional to Vbe and decreases linearly with temperature (CTAT). In other instances, a comparison of a temperature-stable reference voltage which may be obtained from a bandgap generator or by compensation between a voltage VPTAT and a voltage VCTAT, and a voltage that varies linearly with temperature, is performed.
There also exist circuits effecting a direct comparison of a voltage which increases linearly with temperature and a voltage which decreases linearly with temperature. Such is the case, for example, with the circuit shown schematically in FIG. 1, which illustrates a temperature sensor formed with bipolar technology. This type of sensor is described in IEEE Journal of Solid-State Circuits, Vol. 31, No. 12, December 1996, page 1912, for example.
The sensor of FIG. 1 illustrates how a voltage VPTAT and a voltage VCTAT can be compared to cause the output to switch over at a desired temperature. In all cases, an analog signal is generated which will cross zero at the desired temperature.
A further prior art embodiment implementing a temperature sensor is shown schematically in FIG. 2. This embodiment shows that a voltage VPTAT and voltage VCTAT can be used to generate two currents. A first current is temperature stable, and a second current is linearly dependent on the temperature. The two currents are compared together to determine whether a desired temperature has been reached. The circuit shown in FIG. 2 is implemented with CMOS technology, and is described in an article by Szekely et al., IEEE Transactions on VLSI Systems, Vol. 5, No. 3, September 1997, page 270, for example.
The circuit illustrated in FIG. 2, although achieving its objective, has a drawback in that generated currents are dependent on the resistance of a resistor R1, which is usually a few megaohms. However, this value can have a substantial process spread.
In addition, the thermal coefficient of the resistor R1 makes generating currents with a desired dependence on temperature difficult to achieve. To overcome such problems, polysilicon resistors are used which exhibit negligible process and thermal coefficient variations. However, in view of the low resistivity per circuit area square (approximately 1-6 Ohms/square) of such resistors, very large silicon areas or relatively large currents must be used, resulting in increased cost.
In view of the foregoing background, it is therefore an object of the present invention to provide a temperature sensor with CMOS technology that has adequate structural and functional features to allow a desired temperature to be detected rapidly and accurately, while reducing the area requirements for the sensor.
This and other objects, features and advantages in accordance with the present invention are provided using CMOS elements in place of a resistor commonly used by conventional sensors for generating the comparison currents.
The CMOS temperature sensor includes a first circuit portion for generating an increasing voltage as the temperature to be sensed increases, and a second circuit portion for generating a decreasing voltage as the temperature to be sensed increases. A comparator compares such voltage values together and outputs an electric signal based upon a predetermined temperature being reached.


A method of communication involving processing by instruction using one or a combination of information units, when a user instructs a terminal to display contents and procedure of a communication, or to totalize the contents of the communication, or when a manager terminal instructs a field of the communication to provide a function of the communication corresponding to an object or stage of the communication. Information units forming the contents of the communication include cards, and information units forming premising information of a communication and a basis of the communication include boards. An information unit comprises a board identifier and attribute information for specifying a function of a board, such as a relationship between the board and cards. To provide a communication function corresponding to an object and stage of the communication, a template conforms to the object and stage so a manager can select and utilize the template.

The present invention relates to a method of effecting communication in a network, to a communication system making use of the method for communication, to a program for the communication system, and to a recording medium on which the program for the communication system is recorded and which is capable of being read by a computer.
In recent years, while servicing of a network infrastructure and circulation of PC/mobile terminals have prevailed the number of people making use of a communication system on a network has been increasing. Existing communication systems include mail, mailing list, bulletin board, chat, and teleconference, and such systems are utilized to generate various communities with networks as a medium, which constitute sources of various activities.
Among these activities, a technique for eliminating a struggle against participation in a communication in a network in a community has become important. The struggle against participation in a communication in a community on a network includes:
(1) The problem of saying too much, so that it is difficult to read messages well.
(2) The thread of a conversation (thread of a plurality of subjects) is complex and difficult to understand ("Networking Community" by Kenichi Ikeda, 1997 Publishing Department of Tokyo University).
As a measure for solving the above-mentioned problems, a bulletin board system and a discussion managing method described in, for example, JP-A-9-231040 (referred to below as prior example 1). In this approach to the above-mentioned problems, a speaker selects and gives an attribute, such as assent, opposition, supplement, alternative proposal, or the like, to his message, thus hierarchically displaying a referenced relationship of articles to make the pro and con of discussions through e-mails easy.
Meanwhile, in the well known KJ method, it is proposed to use a plurality of cards to perform arrangement and analysis of information, and an idea support tool based on the KJ method has been realized. We have Investigated and studied an accumulation type communication system (page 156 to 157, proceedings of the 18th conference of Nippon Perception Scientific Association, referred to below as prior example 2), with the use of a metaphor composed of cards and boards constituting a base therefor. In this system, a board forming a base for editing, sharing and accumulation of information and cards each representative of one item of information are used, such that an attendee in a community can describe information, which he wants to relate, on a card, and sticks the card in an optional position on the board through a network.
With the prior example 1, it is possible to clearly state the relationship between a particular theme and a contributed article and the relationship between contributed articles, but it is hard to clearly state the relationship between a plurality of themes and a contributed article, the n to n relationships between a plurality of contributed articles, and the course of things.
Meanwhile, with the prior example 2, the problem in the prior example 1 can be solved by using a board, which shows prerequisite information concerning a communication, cards, and link lines among the cards and between a card/board; however, but only showing all the relevance among complex cards on the board and between card/board makes it difficult for a user to easily understand the circumstances of a communication and to search and read contents of comments, about which he is concerned. Also, with the prior example 2, accumulation of every card is possible, and so arrangement and analysis of contents of a communication are facilitated; however, it cannot be said that information required for the arrangement and analysis of the contents of a communication can be fully made use of, because information in the background of the board is not made an object of information. In a communication in an optional community on a network, since a variety of members participate in the communication at any time, it can be said that it is a great task to display the contents and progress of the communication in an understandable manner.
Also, in both the prior examples 1 and 2, the function of supporting a communication is constant at the beginning and the end, irrespective of the process of the communication. While the function of allowing communication as freely as possible in, for example, an initial stage of a communication is demanded; however, the function required in the course of a communication is varied such that the function of supporting an aggregation of discussions man advanced stage of a communication is demanded. The prior examples 1 and 2 cannot provide the function of supporting a communication in a stepwise manner according to the object and progress of the communication, and whether a communication can progress well depends upon the operation on the side of a manager. Since the operation in a field of a communication in a community on a network involves a great load, it can be said that it is an important task to provide a function of causing smooth progress of a communication to support a manager in the field of communication.


Systems, methods, apparatus, and techniques are provided for processing data from a storage medium. A stripe of data stored on the storage medium is read, where the stripe comprises a plurality of data allocation units (AUs) and a parity AU. Error correction decoding is applied to each of the plurality of data AUs to produce a plurality of decoded data AUs. It is determined whether a value of the parity AU is satisfied by values of bytes in the plurality of decoded data AUs. The plurality of decoded data AUs are output in response to a determination that the value of the parity AU is satisfied by the values of bytes in the plurality of decoded data AUs.

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the inventors hereof, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A solid state drive (SSD) reads and writes data from devices such as NAND flash memory devices or dynamic random access memory (DRAM) devices that may be implemented using a RAID architecture. The SSD typically includes an SSD controller with a number of data channels for transferring data to and from the NAND flash memory. Further, the SSD controller typically executes firmware that manages data in fixed byte size units known as allocation units (AUs). Traditionally, data is written to a given page of the NAND flash memory in a single operation and the write operation includes a number of bytes that is an integer multiple of the size of an AU. Thus, when a page size of the NAND flash is not an integer multiple of the AU size, the memory of the NAND flash may be underutilized.

Architecture for storage of data on NAND flash memory


A semiconductor apparatus includes a multilayer interposer substrate including a power layer as an inner layer; a plurality of connection terminals provided on one surface of the interposer substrate; and a semiconductor chip mounted on the other surface of the interposer substrate. Among power terminals, ground terminals, and signal terminals provided in the semiconductor apparatus, all the power terminals are arranged in one power area and the power area includes only the power terminals.

Semiconductor integrated circuits (hereinafter referred to as semiconductor chips) typified by application specific integrated circuits (ASICs) each include a core circuit that processes signals, an input-output circuit that inputs and outputs signals from and to an external circuit, a power supply, and a ground input circuit (GND input circuit). The power supply and the GND input circuit are used by the core circuit and the input-output circuit.
In a typical semiconductor apparatus, the semiconductor chip is installed in a member called a package. Mounting the package having the semiconductor chip installed therein on a print circuit board causes the signal input-output circuit, the power supply, and the GND input circuit in the semiconductor chip to be connected to the print circuit board.
There are many types of packages. When a semiconductor chip having 100 or more input-output terminals is used, for example, a ball grid array (BGA) package is often used. The package such as the BGA package includes a substrate called an interposer and the semiconductor chip is installed on the interposer. The interposer has signal, power, and GND patterns that are wired. The semiconductor chip is connected to the input-output terminals via the wiring.
Since multiple power supplies and multiple GND input circuits for the signal input-output and the core circuit exist in each semiconductor chip in recent years, multiple power patterns and multiple ground patterns exit on the interposer substrate. Accordingly, various measures have been heretofore adopted in order to stabilize the power supply and the grounding.
A method is known in which the power patterns are caused to oppose the GND patterns on the interposer substrate to produce capacitive components between the power patterns and the GND patterns in order to stabilize the power supply and the grounding. U.S. Pat. No. 6,999,299 discloses a technology in which a power plane is divided from a GND plane in the inner layer of the interposer substrate and the power terminals and the GND terminals are alternately arranged to ensure the capacitance.
The current consumption in the semiconductor chip is increased due to miniaturization of a semiconductor process to cause a problem of reduction in direct current (DC) voltage and/or electromigration. Accordingly, it is necessary to build a structure capable of keeping lower impedance and causing a large amount of current to flow by decreasing the resistances of the power patterns and the GND patterns in the semiconductor apparatus and the print circuit board.
In addition, the increase in the current consumption in the semiconductor chip promotes use of many power supplies in the semiconductor chip. For example, the power supply of the semiconductor chip is divided into multiple power supplies to stop some of the circuits during the operation or to supply lower voltage to circuits having lower operation frequencies. Consequently, the power patterns and the GND patterns in the semiconductor apparatus are required to have a structure that is easy to support the many power supplies in the semiconductor chip. However, many via holes for different voltages exist in the respective power and GND areas (for example, many GND via holes and many power via holes for different voltages exist in the power area) in the method in the related art, typified by the technology disclosed in U.S. Pat. No. 6,999,299, in which many via holes for the power supply and the grounding are closely arranged. Accordingly, the effective resistance is practically increased due to the many through holes even if the plane shape is adopted in order to reduce the resistance to prevent the impedance from being kept at a lower value.

Semiconductor apparatus having power through holes connected to power pattern


Apparatus for recording and/or reproducing user data recorded on a record medium. The apparatus includes record encoder for converting original user data into encoded user data of a predetermined record code and as error correcting code generator for generating original error correcting code data for correcting an error with respect to the encoded user data. A write unit records the encoded user data and the error correcting code on the record medium. A read unit reads the recorded data and the reproduced data is error corrected so as to provide the original user data.

A conventional magnetic disk device has a construction as shown in Japanese Unexamined Patent Publication No. 345967/1992. FIG. 26 shows the construction in such conventional technology. Further, a record format of a conventional magnetic disk device is shown in FIGS. 28(a)-28(d). FIG. 28(a) shows an index pulse which is generated once per rotation of a disk, FIG. 28(b) shows sector pulses which are generated at respective sectors, FIG. 28(c) shows a record format, and FIG. 28(d) shows a diagram magnifying the record format of each sector.
In FIG. 26, a magnetic disk device 150 sends and receives data to and from a host computer 101 such as a personal computer or a workstation via an interface bus 102. The magnetic disk device 150 includes a disk 109 of a disk type record medium, an interface controller 103 for controlling of sending and receiving data to and from the host computer 101 via the interface bus 102, a CPU 140 for controlling the inside of the magnetic disk device, a HDC (hard disk controller) 104 for controlling the access of data to the disk, so ECC (error correction code) circuit 105 for adding an error correcting/detecting code, a ENDEC (encoder/decoder) 106 for converting a code having a code form of NRZ into a run length limited code that is adapted to record on the magnetic disk and vice versa, a R/W (read/write) AMP 107 that is an amplifier, a head 108 for reading or recording magnetic information, a data buffer 111 for recording data, and a read control unit 110 for controlling a reading operation.
In FIG. 26, in writing data on the disk 109, firstly, write data which has been inputted from the host computer 101 is stored in the data buffer 111 through the interface bus 102, the interface controller 103 and the HDC 104. Next, an error correcting/detecting code is added to the data stored in the data buffer 11 by the ECC circuit 105 in the HDC 104. The code having a code form of NRZ of the write data which has been inputted from the host computer 101, is converted into a run length limited code such as (1,7) code or (2,7) code that is adapted to be recorded on the magnetic disk at the ENDEC 106. A voltage of the ENDEC 106 is amplified by the R/W AMP 107, and the amplified data is written on the magnetic disk 109 through the head 108. The run length limited code (RLL: Run Length Limited) restricts a continuation of "0" (called "run") which are present between "1" and "1" in a data series. The first numeral in the parenthesis of (1,7) code or (2,7) code indicates a minimum value of the length of the run and the second numeral indicates the maximum value thereof. For instance, in the (1,7) code data, a "0" is always placed succeeding to "1" but there is no continuations of "0" by 8 or more. In this way, the recordable bit density is enhanced in comparison with the density of the magnetization reversal of the disk. The run length limited code signifies a record encoding wherein a data series is produced by conversion that is adapted to a characteristic of a recording and reproducing system.
Further, in reading data from the disk, the magnetic information written on the disk 109 is converted into an electric signal by the head 108, the voltage thereof is amplified by the R/W AMP 107, the analog signal is converted into a digital signal by the read control unit 110, and the run length limited code is converted into the NRZ code by the ENDEC 106. Next, error detection is performed by the ECC circuit 105, the error is corrected when it occurs in the read data, and the corrected data is stored in the data buffer 111. The data stored in the data buffer 111 is transferred to the host computer 101 through the HDC 104, the interface controller 103 and the interface bus 102.
Recently, PRML (Partial Response Maximum Likelihood) has been used as a next generation signal processing technology, as described in Japanese Unexamined Patent Publication No. 190934/1987, "Viterbi Detection of Class IV Partial Response on a Magnetic Recording Channel", IEEE Transaction on Communications, vol. Com-34, No. 5, May, 1986, pps. 454-461, "Signal Processing System PRML Supports a Large Scale Memory Device of Next Generation", Nikkei Electronics, Jan. 17, 1994 (No. 599), pps. 71-97 and the like. The PRML system detects the most likely data series (bit series of the maximum likelihood) among all the occurrable signal series by using the PR (Partial Response) system which performs an effective transfer by allowing inter-code interference of data and by using a decoding method called Viterbi algorithm. There are a number of systems in the PR system depending on what kind of inter-code interference is provided. For instance, PR (1,0;−1) (=PR4) is a system of providing a characteristic of (1D) (1+D) to a recording and reproducing system. In using the PRML system; There are many cases wherein (0,4,4) GCR (Group Coded Recording), or 8-9 conversion code is employed as the run length limited code, as shown in Japanese Examined Patent Publication No. 6699/1991. The (0,4,4) GCR signifies that the run is not smaller than 0 and not larger than 4, and in which the last numeral 4 signifies that the maximum value of the run is 4 in view of every other bit of a data series after encoding. Further, the 8-9 conversion Code is one of codes called block code, which signifies that an 8 bits data is converted into a 9 bits data. The block code converts m bits of an original data series into data having a bits (m≦n). It maps combinations suitable for the recording and reproducing characteristic in the a bits data from all the combinations of the m bits data.
With the larger capacity and higher density of a magnetic disk, the S/N is deteriorated, as described in "Design Acknowledging Medium Defect in Small Scale HDD Starts. Importance of Error Correction Using ECC Enhances". Nikkei Electronics, Aug. 5, 1991 (No. 533), pps. 141-146. As a remedy for the deterioration of the S/N, a method has been used wherein redundancy bits of the error correcting code are increased and a strong error correcting code is added. As such an error correcting code, for instance, an error correcting code called BCH Code (Bose-Chaudbun-Hocquenghem Code) or Read-Solomon Code has been commercialized. In such an error correcting code, the redundancy bits should be increased in accordance with an increase in the number of error bits to be corrected.
FIG. 27 shows a system in block diagram form wherein an error correcting code is added using the PRML. In FIG. 27, the ECC circuit 105 in the HDC 104 adds an error correcting/detecting code to the write data stored in the data buffer 111, and the ENDEC 106 converts the code having a code form of NRZ of write data which has been inputted from the host computer 101, into the run length limited code that is suitable for recording on the magnetic disk. Further, a convolution encoding called pre-coding is carried out in the signal processing circuit 110 to perform the PRML, by which a regularity is provided to the data. Thereafter, in the R/W AMP 107, the voltage of the pre-coded write data is amplified, by which the writing is performed on the magnetic disk 109 by the head 108. In the PR system, since the inter-code interference is included in the reproduced waveform, it is necessary to remove the inter-code interference to reproduce the original data. Therefore, normally the operation of previously providing an inter-code interference which is inverse to that provided in the recording and reproducing system, is called pre-coding. For instance, an encoding which performs the pre-coding of PR (1.0,−1) (=PR4) to data of the NRZ (Non Return to Zero) system is called interleaved NRZI.
Further, in FIG. 27, in reading data, an electric signal which has been read from the head 108, is amplified by the R/W AMP 107, an error is corrected by ML decoding using the regularity provided to the precoding in the signal processing circuit 110, and the signal is digitized and inputted to the ENDEC 106. The run length limited code is converted into the NRZ code data in the ENDEC 106, successively, an error detecting is performed in the ECC circuit 105, and the error is corrected in case wherein the error has occurred in the read data.
Reference is made to FIG. 29 for an explanation of a behavior of propagation of error occurrence in case wherein, for instance, the PRML of Class 4 is employed as the PRML, a 8-8 convening code is employed as a run length limited code. As shown in FIG. 29, in case wherein an error of 1 bit occurs in reading data that has been recorded on a disk medium, when the data is decoded by the signal processing circuit 110 and is inputted to the ENDEC 106, it becomes an error of 2 bits (on the 8-8 converting code shown in FIG. 29) due to the characteristic of PRML Further, when the 8-8 converting code is converted into the NRZ signal in the ENDEC 106, it is magnified into an error of 2 bytes (on the NRZ code shown in FIG. 29) since it is encoded in the block code. When the length of data is 512 bytes, redundant bits of 48 bits at a minimum is required to correct a continuous 2 bytes in case of the Read-Solomon code.
Further, in the conventional technology, as shown in FIG. 28(d), the error correcting code (ECC) is added only to the write date, and no consideration is given to a case wherein an error occurs in a BYTESYNC region of a synchronization signal, or an identification portion including an area for storing an identification number that is identification information of each sector, or the like. At present, the BYTE-SYNC is provided with about 1 byte. However, when an error resistance function is to be provided to the NRZ signal in adopting the PRML or the 8-8 converting code, a BYTE-SYNC region of 5 bytes or more is necessary by adding redundant bits, which very much deteriorates a format efficiency (a ratio of a data capacity as compared with all the memory capacity). Similarly, at present, a CRC (error check code) of 2 bytes is added to the identification portion. However, to provide an error correction capability, a ECC of 4 bytes or more is necessary by adding redundant bits, which very much deteriorates the format efficiency.
Generally, in performing the error correction, the number of the redundant bits of the ECC is necessary to be two times or more of the number of bits to be corrected. The larger the size of error to be corrected, the more it is necessary to increase the redundant bits, which deteriorates the format efficiency.
As stated above, in the conventional technology, writing is performed by converting a data series into the run length limited code after providing the error correcting code thereto in encoding. Conversely, a decoding is performed by the PRML at the signal processing circuit 110 in decoding, and the error correction is performed by the error correcting code after inversely convening the run length limited code. Then, in occurrence of an error, an error occurs which has a regularity specific to a signal processing system that is carried out in the signal processing circuit 110, and the number of bits having the error is increased. Further, in converting it into the NRZ signal in the ENDEC 106, the size of error is further magnified. When the size of error to be corrected is magnified, it is necessary to increase redundant bits.
Further, as mentioned above, in the conventional technology, no consideration has been given to the occurrence of an error in the BYTESYNC region, the identification portion or the like, and it is desirable to provide the error correction capability to these regions.

Apparatus and method for error correction


The present invention provides an apparatus for molding a material such as plastic. The apparatus includes a mold body, a first plurality of ribs, and a second plurality of ribs. The mold body includes a molding skin of substantially uniform thickness having a first surface and a second surface. The first surface is adapted to mold a part. The second surface is opposite the first surface. The first plurality of ribs extend from the second surface. A plurality of thermal conduction surfaces are defined on the second surface between the first plurality of ribs. The second plurality of ribs are interleaved with the first plurality of ribs. The second plurality of ribs include end surfaces displaced a substantially uniform distance from the plurality of thermal conduction surfaces to define a plurality of fluid flow conduits adapted to contain a coolant.

Molds for injection, thermoplastic, thermoset, blow, or reaction molding typically are manufactured from metallic materials such as steel, stainless steel, aluminum, or copper based alloys. These materials possess properties suitable to a wide variety of mold tool requirements. Thermal conductivity, strength, hardness, machine-ability, durability, and cost are primary considerations. Molds typically have two halves and a core. These components mate with each other in a sealed off fashion. When in the closed condition, a cavity exists between the two halves. This cavity defines the product to be molded. Complex products may require additional mechanical actions to create special features.
Electrically heated manifold systems internal to the mold are often utilized to deliver hot melted resin from an injection press nozzle to the cavity through a series of channels in the mold manifold. After the mold opens and the molded part has cooled adequately, mechanical pins or other means eject the part from the mold. The time required to cool the part is determined by the capability of the heat management system incorporated in the mold. Typically, molds have a bore or series of bores in the core blocks for carrying a coolant. The coolant extracts heat from the molded product during the molding cycle. These bores are designed in various configurations utilizing accepted fluid dynamic physics. System layouts can include serial bores, parallel bores, or a combination of both. Serial systems link one or more bores in sequential order, referred to as a circuit with bore size remaining constant. Parallel systems supply fluid via larger bores to a series of smaller bores, similar to lawn irrigation systems.
These serial and parallel systems, however, are designed with the limitations of traditional manufacturing technologies such as drilling. Drilled bores are generally limited to being straight. Therefore, to achieve a non-linear bore, a series of intersecting bores must be drilled. The series of intersecting bores are unable to follow the smooth irregular contour of many molded parts and, consequently, cannot achieve uniform heat transfer.
Other established mold design/manufacturing techniques additionally utilize conventional or computer controlled machining to cut square or "U" shaped channels through plates, cylinders, cones, and other mold components. A plurality of mating plates are then stacked to cover the open side of the channel. "O" rings or other gasket materials are utilized to seal the mated plates. The molded part surface is generally on the opposing side of the plate or component that has the channel machined through it. While this allows more complex cooling systems to be created than the conventional drilling technique, it is limited to generally flat or cylindrical conditions and cannot consistently follow free form shapes.


An optical recording medium containing control information to set the write power at an optimum level for recording information on the medium. The control information includes a preset value of the derivative of the modulation of a read signal with respect to the write power. The optimum write power is derived from values of the modulation measured from test patterns on the medium and the preset value recorded on the medium.

The invention relates to an optical recording medium inscribable by a radiation beam, containing control information indicative of a recording process by which information can be recorded on the information carrier, the control information comprising values of recording parameters for the recording process.
Such a recording medium is known from EP-A-0 397 238 (PHN 12.925). This information carrier is a disc of an optically inscribable and readable type such as, for example, a Compact Disc Write Once (CD-WO), compatible with media of the CD class, and has a prerecorded track portion, a so-called pregroove. The pregroove is intended for recording optically readable patterns in accordance with the recording process, which patterns represent information. The pregroove is furthermore modulated with an auxiliary signal which contains address codes and control information. The control information comprises data useful for optimizing the recording process, such as the write power level required for recording.
An optical recording apparatus, set up for recording information on such a medium, can read the control information from the medium and adjust its recording parameters in accordance with the values recorded on the medium in order make a reliable recording of the information in the form of marks on the medium. Recording parameters are understood to be parameters which directly control the recording process. If the apparatus records information by modulating the power level of the radiation beam, these parameters may include one or more speeds of recording, power levels of the radiation beam used during the recording, such as a write power level, a bias power level, the duration of a first, intermediate and last pulses of a series of pulses used for writing a mark on the medium and duty cycles of these pulses. Several values of each parameters for specific recording speeds may be recorded. If the recording process includes erasure of previously recorded information either by direct overwrite or in a separate pass, the parameters may also include parameters related to the erase process such as the erase power.
Read parameters are understood to be parameters derivable from signals obtained when reading the information on the medium and which are useful for optimizing the value of one or more recording parameters. In general, a method for adjusting a specific recording parameter will involve recording a series of test patterns on the medium, each pattern having a different value of the recording parameter, measuring the read parameter of each pattern, and determining the optimum value of the recording parameter from this information. Examples of read parameters are the maximum value of a read signal, the modulation of a read signal, the reflection of the medium, the jitter of a read signal and the error rate of information recovered from the read signal.
European patent application no. 0 737 962 discloses an optical recording apparatus which does not require control information from an optical medium in order to set its write power level for recording information on the medium. Instead, the apparatus records a series of test patterns, each with increasing write power, on the medium. Next, it derives the modulation of each pattern from a read signal portion corresponding to the pattern. It calculates the derivative of the modulation as a function of write power and normalises the derivative by multiplying it by the write power over the modulation. The intersection of the normalised derivative with a preset value determines a write power level suitable for recording on this medium. The method thus uses the write power as recording parameter and the read signal modulation as the read parameter. This procedure for setting the optimum write power takes the different characteristics of the media into account by measuring the modulation of test patterns written on the media. Moreover, the method is independent of the specific recording apparatus used because of the normalised derivative employed in the procedure. The derivative is insensitive for apparatus parameters such as the numerical aperture of the objective lens for focusing the radiation beam on the medium, the intensity distribution over the radiation beam and the size of the spot formed by the radiation beam. The known method is designed to provide a proper setting of the write power level for each combination of recording apparatus and medium. However, experiments have revealed that the known method does not result in a proper write power level for all combinations of apparatuses and media.
The above citations are hereby incorporated in whole by reference.

Optical recording medium with recording control information


The present invention relates to a multilayer laminated product which at least contains a layer formed of an acrylic resin composition containing an acrylic resin as a main component, and a specific terminally-modified polycarbonate resin. Moreover, the multilayer laminated product of the present invention has an excellent releasability and low frictional properties.

Acrylic resins are applied in various fields such as an optical lens, a protection material for a liquid crystal panel and an aquarium because of their excellent transparency and scratch resistance. Above all, they are often used for a hard coating on the other resins since the surface is hard and has excellent scratch resistance. Especially, a polymer laminated body such as a multilayer sheet in combination with polycarbonate which also has excellent transparency and high impact resistance is quite suitable for a field such as various kinds of windowpanes, a transparent roof and a transparent panel member wherein scratch resistance and impact resistance are required, and the demand is high.
Examples of way for laminating an acrylic resin with a polycarbonate resin include known methods such as (1) a method of co-extruding a polycarbonate resin and an acrylic resin to mold a multilayer sheet and (2) a method of coating a monomer of the acrylic resin on a polycarbonate resin sheet substrate and then curing by light or heat. Of the two methods, the method (1) has been commonly used in these days for the reason that the method (2) has problems such as work environment pollution by volatilization of acrylic monomers and complicated management of coating and/or curing equipments. However, the method (1) also has problems that releasability of the acrylic resin from the sheet molding roll at the time of co-extrusion is poor, which would occasionally cause deterioration in moldability and appearance.
In order to solve the above problems, methods of using an acrylic resin composition comprising various types of lubricants are disclosed (Patent Document 1, Patent Document 2). According to these methods wherein lubricants such as fatty acid ester and fatty acid amide are used, though roll releasing properties may be improved, accumulation of lubricants on the roll and whitening under the circumstances of high temperature and high humidity may occur in some cases, and there is room for improvement.
Meanwhile, it is known to use a modified polycarbonate resin having a silicone structure in its main chain (Patent Document 3). Since this modified polycarbonate is a polymer having a high molecular weight, problems caused by volatilization can be solved. However, releasability thereof is not necessarily satisfactory and there is room for improvement.
In addition, thought a modified polycarbonate having a silicone structure in its molecular terminal itself is known (Patent Document 4), there is no case of applying it to an acrylic resin having different refraction index and compatibility, and there is no knowledge about transparency, slidability and environmental stability.    Patent Document 1: Jpn. Pat. Laid-Open Publication No. 2005-225018    Patent Document 2: Jpn. Pat. Laid-Open Publication No. 2006-205478    Patent Document 3: Jpn. Pat. Laid-Open Publication No. H05-200827    Patent Document 4: Jpn. Pat. Laid-Open Publication No. H07-258398

Acrylic resin composition and moldings in which said composition is used


A method for forming at least one product silane, comprising reacting a transition metal hydride with a starting silane in a presence of a catalyst and at a temperature that exceeds a threshold temperature associated with said reacting.

The present invention relates to a method and apparatus for forming at least one silicon-carbon bond in a silane.
Methyl chlorosilanes are typical starting materials used commercially in the manufacture of silicone polymers. Methyl chlorosilanes, comprising a silicon-carbon bond, are formed in a reaction between methyl chloride and elemental silicon, first disclosed by Rochow in 1945 in U.S. Pat. No. 2,380,995. However, the Rochow reaction relies on a costly energy consuming reduction of silicon dioxide to elemental silicon. Thus, there is a need for a method and apparatus for forming silicon-carbon bonds that avoids using the costly energy consuming reduction of silicon dioxide to elemental silicon.
The present invention provides a method for forming at least one product silane, comprising reacting a transition metal hydride with a starting silane in a presence of a catalyst and at a temperature that exceeds a threshold temperature associated with said reacting, wherein the starting silane has a chemical form of TnSi(OR)(4xe2x88x92n), wherein the at least one product silane includes at least one silicon-carbon bond that is not present in the starting silane, wherein each T is independently a hydrogen atom or a monovalent hydrocarbon group, wherein each R independently includes a monovalent hydrocarbon group, and wherein n is an integer in a range between 0 and about 3.
In addition, the present invention provides a product silane having the chemical form of (Rm)(Tn)Si(OR)(4xe2x88x92mxe2x88x92n), wherein each T independently includes a monovalent hydrocarbon group, wherein each R independently includes a hydrocarbon group, and wherein n is an integer in a range between 0 and about 3, wherein m is an integer in a range between about 1 and about 4xe2x88x92n, wherein the product silane is formed by the process of endothermically reacting a transition metal hydride with a starting silane in a presence of a catalyst and at a temperature that exceeds a threshold temperature associated with said reacting, and wherein the starting silane has a chemical form of (Rmxe2x88x921)(Tn)Si(OR)(5xe2x88x92mxe2x88x92n).

Method and apparatus for forming a carbon-silicon bond in a silane


A powder sintering lamination apparatus forms a powder layer having a predetermined thickness from a fiber-containing resin powder supplied onto a shaping table using a flattening device. The apparatus irradiates a predetermined place of the powder layer on the shaping table with laser light from a laser light irradiation module, sinters the part of the powder layer irradiated with the laser light to form a solidified layer, and forms a three-dimensional shaped object on the shaping table by laminating a plurality of the solidified layers integrally with each other. The flattening device includes a first blade and a second blade that move in different directions. The movement track of the first blade on the shaping table orthogonally intersects with the movement track of the second blade on the shaping table. The first blade and the second blade move alternately on the shaping table.

A device (powder sintering lamination apparatus) that forms a three-dimensional shaped object using the powder sintering laminate method has come into widespread use in recent years. This powder sintering lamination apparatus forms a three-dimensional shaped object on a shaping table, the three-dimensional shaped object including a plurality of solidified layers laminated integrally with each other by repeating the process in which a powder material accommodated in a powder material tank is carried onto the shaping table using a blade, a powder layer having a predetermined thickness is formed on the shaping table from the powder material using the blade, a predetermined place of the powder layer on the shaping table is irradiated with laser light from laser light irradiation means, and the part of the powder layer irradiated with the laser light is sintered (solidified) (see JP-A-2011-26668).
However, since the blade reciprocates only in one direction (for example, the direction along the X axis direction or the direction along the Y axis direction when the upper surface of the shaping table is assumed to be the X-Y plane) in the conventional powder sintering lamination apparatus, when fiber-containing resin powder is used as the powder material, the orientations of fibers 101 are aligned in one direction (see FIG. 7B), thereby causing a problem in that the strength and dimensional accuracy of a three-dimensional shaped object 100 differ significantly between directions (for example, the X axis direction and the Y axis direction).
Therefore, the invention provides a powder sintering lamination apparatus that prevents the strength and dimensional accuracy of a three-dimensional shaped object from differing significantly between directions when fiber-containing resin powder is used as the powder material.


Provided are communication apparatus and a communication method that allow for secure communication even in a case that an eavesdropper has multiple antennas. An apparatus includes a transmitter configured to transmit a constant amplitude signal from three or more transmit antennas; a controller configured to control a phase of the constant amplitude signal, based on channel information and a target symbol; and a modulation unit configured to generate a modulation symbol from bits. The target symbol is generated by multiplying the modulation symbol by an amplitude coefficient.

Research and development activities related to the 5th generation mobile radio communication system (5G system) have been actively carried out, aiming to start commercial services around the year 2020. A vision recommendation on the standard system of the 5G system (International Mobile Telecommunication-2020 and beyond: IMT-2020) was recently reported (see NPL 1) by the International Telecommunication Union Radio communications Sector (ITU-R), which is an international standardization body.
It is considered that radio communication will become more and more important in the future, and accordingly the number of communication apparatuses will further increase as well. In this case, security may present a problem. Security is one of the most important technologies in a communication system. In general, for security, secure communication using encryption in the higher layer, rather than the physical layer, is used in many cases. However, since radio communication is transmitted in a wide range, an eavesdropper may be able to receive control information and the like that are not encrypted. In such a physical layer, physical layer security is present as a technology for implementing secure communication. As a physical layer security technology, for example, there is a technology in which artificial noise, which is rendered null for an authorized user and non-null for an eavesdropper, is added to a transmit signal for transmission. The artificial noise is a technology of enabling secure communication with channel information between a transmitter and an authorized user being used as a key, and making eavesdropping of an eavesdropper difficult. The physical layer security technology using the artificial noise is described in NPL 2.

Communication apparatus and communication method