Abstract: A non-volatile memory cell is provided. The non-volatile memory cell includes a first conductivity type semiconductor substrate, second conductivity type source/drain regions longitudinally arranged in a direction to be parallel to each other and separated from each other by a predetermined distance in the semiconductor substrate, such that the second conductive source/drain regions define a channel region therebetween. A tunnel oxide layer is formed on the semiconductor substrate. First conductive layer patterns are formed on the tunnel oxide layer on the channel formation region in the form of islands. Buried oxide layers fill spaces between the adjacent first conductive layer patterns. Second conductive layer patterns are formed on the upper surfaces and the upper side surfaces of the first conductive layer patterns and arranged so that their edges are extended to some surfaces of the buried oxide layers.

Abstract: A circuit configuration is described which provides the advantage that data can be read out of a serially readable data memory via a freely selectable number of existing data outputs. This is advantageously achieved in that the serial data are routed with a delay effected by memory/delay circuits to a plurality of data outputs.

Abstract: A semiconductor memory device having a self-refresh operation includes a first circuit generating a first signal that specifies a first self-refresh cycle by a non-volatile circuit element provided in the semiconductor memory device, a second circuit receiving a second signal that specifies a second self-refresh cycle via a terminal that is used in common to another signal, and a third circuit generating a pulse signal having one of the first and second self-refresh cycles, the pulse signal being related to the self-refresh operation.

Abstract: A semiconductor memory device having a self-refresh operation includes a detection circuit generating a detection signal when detecting a change of a given input signal, and a comparator circuit comparing the detection signal with a refresh request signal internally generated and generating a control signal indicative of a circuit operation.

Abstract: A voltage generating circuit of the present invention includes a charge pump regulator and a voltage converting circuit. Charge pump regulator receives Ext.Vcc and a ground voltage as inputs and outputs a negative voltage Vbb1. Charge pump regulator receives Int.Vcc and negative voltage Vbb1 as inputs and outputs negative voltage Vbb2(<Vbb1). Voltage converting circuit receives Int.Vcc and negative voltage Vbb2 as inputs and outputs an output voltage Vnn. In each of charge pump regulator, a voltage difference between the input and the output is designed such that it is equal to or lower than a prescribed value determined by a size of a transistor.

Abstract: A semiconductor memory device includes isolation circuits disconnecting cell arrays from sense amplifiers, and isolation signal generating circuits generating isolation signals that control the isolation circuits. The isolation signal generating circuits are hierarchically divided into main isolation signal generating circuits and sub isolation signal generating circuits. The sub isolation signal generating circuits generate sub isolation signals having a first potential on a high-potential side. The main isolation signal generating circuits generate main isolation signals having a second potential on the high-potential side, the second potential being lower than the first potential.

Abstract: A first test clock signal and a second test clock signal are generated from a common basic test clock signal using a delay line with a changeable delay time and a delay stage with a fixed delay time. A memory circuit is operated in synchronization with one of the first and second test clock signals, and the memory circuit is provided with a signal/data according to the other test clock signal. Thus, the set-up time and the hold time of a signal for the memory can be measured with accuracy in a memory-merged system LSI.

Abstract: The invention provides a method and an assembly for the batch-wise preparation of a liquid product constituted by a mixture of at least one primary liquid and at least one secondary liquid. The secondary liquid and liquids, respectfully, to be meteredly added to the flowing primary liquid are displaced, before the metered addition, from a main reservoir to a buffer reservoir. Each of the secondary liquids is conveyed by means of an associated conveyor operating according to the displacement principle. The conveyors are hydraulically operated, whereby the same liquid can be used both as hydraulic operating medium and as primary liquid. A mixing element is provided for mixing the primary liquid with the secondary liquid or liquids. The primary liquid is under pressure, since it can be blended with carbon dioxide. The secondary liquid or liquids are supplied to the mixing element under a pressure that is higher than the pressure inherent to the primary liquid in the mixing element.

Abstract: Integrated in the mixing head of a polyurethane apparatus for producing a mixture stream of chemically reactive plastic components, is a cutting arrangement by which natural fibers or fiber strands of soft-elastic and tough consistency can be drawn from a continuous strand and, after cutting into fiber pieces of given length, can be introduced into the mixture stream. The cutting arrangement includes an inner guide tube which receives a fiber strand, drawn from a continuous fiber strand by two feed rollers, and fed via the guide tube and an outer support tube to rotating knife elements. By subjecting the guide tube to a vacuum and applying a compressed gas stream to the end of the outer support tube, the soft-elastic fiber strand is held straight in a manner which is optimal for the cutting process. The cut fiber pieces are introduced together with the gas stream into the mixture stream of chemically reactive plastic components.

Abstract: A method and apparatus for configuring indicating configurations for containers wherein at least a subset of indicating configurations include an enhanced indicating device such as an electronic storage device, the containers to include enhanced devices being a function of whether or not the end user uses an interacting device capable of receiving information from the enhanced devices, the method and system indicating whether or not standard or enhanced containers should be used for specific prescriptions or orders and, in some cases, automatically providing the correct container and specifying (i.e., printing and writing) information to the containers.

Abstract: Time interval measuring instrument including supported on a base, a transparent guide and two marking strips arranged on opposite longitudinal sides of the guide and provided with marking lines and figures, with the indicator parts being piled up on the bottom upon being introduced through the top guide opening.

Abstract: The present invention provides an ultraviolet-curable composition having satisfactory protective performance even in endurance testing at high temperature and high humidity in an optical recording medium having for its reflective film Ag or a metal and/or alloy having Ag for its main component, and an optical recording medium in which it is applied. A cured film of an ultraviolet-curable composition, for which the pH value of a 1 wt % methanol solution of said ultraviolet-curable composition is within the range of 4.5 to 6.8, is coated onto a reflective film in the form of a protective film.

Abstract: A thermally-assisted magnetic recording head and a magnetic recording apparatus having the magnetic recording head built in are disclosed. The magnetic recording head is capable of recording magnetic information by heating a recording unit of a recording medium and raising its temperature to reduce magnetic coercive force and then applying recording magnetic field to the recording unit having the reduced coercive force. The magnetic recording head has a light absorbing film having an aperture, a laser device emitting and directing light through the aperture to the recording medium to head the recording unit and raise its temperature, and a recording magnetic pole for applying the recording magnetic field to the recording unit.

Abstract: A recording medium reproduction apparatus is provided, which apparatus includes: a reproduction instruction unit which inputs instructions on a direction and a rate of a scratch reproduction of a recording medium; a data storage unit which stores data read out from the recording medium, the data being separated by a reference position at which the scratch reproduction is started into first and second halves each having a predetermined time length; and a scratch reproduction system which reads and reproduces the data stored in the data storage unit in accordance with the instructions input by the reproduction instruction unit.

Abstract: A pickup is moved in the radial direction of a partial CD-R, and the end position of a recorded area in the partial CD-R is detected based on a feature signal (on track signal) in the radial direction obtained during the movement. Information recorded in the recorded area is reproduced based on the detected end position, so that an accessing inability can be avoided, and the information in the recorded area can correctly be reproduced. Thus, information recorded in the partial CD-R can correctly be reproduced.

Abstract: A servo control apparatus for carrying out a servo control when information is reproduced from an information record medium having an embossed area where information cannot be recorded, such as DVD-RW, is provided. The servo control apparatus detects a position of a light spot formed by the light beam except the embossed area on the information record medium, and shifts the light spot beyond the embossed area to a predetermined target position to be radiated with the light beam, which is positioned in another side of the embossed area on the information record medium, on the basis of the detected position.

Abstract: In a method of the present invention for controlling stepping motor, the stepping motor driving current is increased or reduced at a fixed inclination in proportion to the time to control the stepping motor effectively, and, a stepping motor driving current pattern is changed by ¼ cycle or more to synchronize the state of excitation between the stepping motor driving means and the stepping motor to control the pick-up very accurately.

Abstract: A portable, fully enclosed compact disc storage apparatus or unit is provided which stores a multiplicity of discs, without risk of damage to their written surfaces. The storage unit comprises a two-part toroidal shaped housing, a circular magazine for supporting the discs, engaged on their unwritten edges by pairs of raised projections limited in height to that of the unwritten portion of a disc. User-actuated means engaged the bottom of the discs and lift them from the magazine and out of the housing through an access slot. Indexing means aligns a disc with the access slot and prevents unwanted rotation of the magazine relative to the housing between disc access and removal. A series of numbers are formed on the outer circumferential flanged edge of the magazine to aid in cataloguing and identifying the magazine's contents.

Abstract: In a focus control of an optical disk with a fast reproduction velocity and a large face deflection, the present invention can effect a mistakeless and reliable focus pull-in method. The present invention comprises: means for applying a braking signal to a focus actuator before closing a focus control loop; means for detecting a reversal of a relative velocity between an objective lens performing a focus search operation and an optical disk which effects an up-and-down motion due to the face deflection; and means for detecting the relative velocity between the objective lens and the optical disk from a focus error signal which is detected in each layer of a multi-layer disk.

Abstract: A device for compensating the error signal produced by a high-speed disk system. The error signal is fed to a compensator and a bandpass filter respectively. The processed signals produced by the compensator and the bandpass filter are summed to output a compensated signal. The bandpass filter processes the rotating frequency portion of the error signal. The compensator includes a lead compensator and a lag compensator either serially connected or parallel connected.

Abstract: In a multimedia copy control system, digital contents data stored in the digital data recording medium includes a first copy control information of a digital format and a second copy control information of an analog embedded format, and encryption of the reproduction output data from the recording medium is decrypted and judged for each digital contents unit under reproduction, and even in the case of detecting no first copy control information, the reproduction of the digital contents data is controlled based on the second copy control information.

Abstract: The present invention provides a recording medium reproduction apparatus that can continuously reproduce different tunes from recording media at the same numbers of beat and the same beat timing. The recording medium reproduction apparatus includes: a first recording medium reproduction unit; a second recording medium reproduction unit; and a control unit that compares the number of beats per unit time of a tune reproduced from a first recording medium with the number of beats per unit time of a tune reproduced from a second recording medium, and adjusts the reproduction rate of the second recording medium reproduction unit so that the number of beats per unit time of the second recording medium reproduction unit becomes equal to the number of beats per unit time of the first recording medium reproduction unit.

Abstract: An optical pickup apparatus includes a light source for emitting a light flux; and a converging optical system having a first, second, and third divided surface, which are divided in the order named from the vicinity of an optical axis of the converging optical system, for converging the light flux emitted from the light source, wherein a beam spot passing through the first and third divided surfaces is formed onto a first optical information recording medium having a transparent substrate whose thickness is t1, and a beam spot passing through the first and second surfaces is formed onto a second optical information recording medium having a transparent substrate whose thickness is t2 that is more than t1. The optical pickup apparatus further includes an image sensor for receiving a light flux reflected from the first and/or second optical information recording medium.

Abstract: A method for reproducing information recorded on a disc is provided. In the method, a reproduction signal is irradiated towards the disc to produce a corresponding read signal. Also, the reproduction signal is positioned at a first position within a non-program area of the disc and is attempted to be focused on the disc. If the reproduction signal is focused on the disc, the method determines if the read signal has a valid signal level. If the read signal does not have the valid signal level when the reproduction signal is positioned at the first position, the reproduction signal is moved to a second position within a program area of the disc while the reproduction signal remains focused on the disc. Then, the method determines if the read signal has the valid signal level when the reproduction signal is positioned at the second position. Also, a disc player that employs the method and a software program that instruct a controller to perform operations in accordance with the method are also provided.

Abstract: A recording medium reproducing device is provided which device varies a tempo and a key of music reproduced from audio data recorded on a recording medium. The recording medium reproducing device comprises means for calculating a variable width of the key according to a varied tempo, means for adding the variable width of the key to a variable width of the key according to a varied key so as to have a summed variable width of the key, and means for displaying the summed variable width of the key.

Abstract: A method of recording and reproducing information in a phase-change optical recording medium by irradiation of an electromagnetic wave for recording, reproducing and/or rewriting information is proposed, wherein when information is recorded in the phase-change optical recording medium by modulating an input signal and conducting pulse width modulation recording, a recording pulse string for recording and rewriting is a continuous electromagnetic wave, and a recording pulse string for input signal, is an electromagnetic wave pulse string having a front-pulse portion fp, a multi-pulse portion mp with a total pulse duration period T and a duty ratio y, and an off-pulse portion op, wherein the duty ratio y is decreased as a recording linear velocity for the phase-change change optical recording medium is increased, whereby multi-speed recording or CAV (constant angular velocity) recording is carried out. An information recording and reproducing apparatus, using the above method, is also proposed.

Abstract: The present invention relates to a device for reading from and/or writing to optical recording media (1) having an optical scanner (2) for scanning the recording medium (1) by means of a light beam (3) and for generating scanning signals (HF) from the reflected beam (3), a data slicer (5) for converting a scanning signal (HF) output by the optical scanner (2) into a binary signal (HF″), an averaging unit (6) for forming an average value (M) from the scanning signal (HF, HF″) as input signal of the data slicer (5), and a control unit (14) for changing a parameter (T, OF) of the averaging unit (6).

Abstract: It is an object of he present invention to provide a disc transfer mechanism that allows a disc to be reliably installed and removed. As shown in FIG. 3, this invention includes a damper means provided between a base (2) and a tray (1) to reduce the moving speed of the tray (1) using the urging force of a spring (3). The damper means comprises a first damper (45) interposed between the tray (1) and the base (2) to reduce the tray moving speed during all the tray moving steps and a second damper that operates, separately from the first damper (45), during the step of delivering a disc set on a turntable to the tray.

Abstract: An optical information recording/reproducing system includes a support member for removably supporting a volume holographic memory formed of a photorefractive crystal, and has a shape of a rotary member having a rotational symmetry axis, with plane surfaces perpendicular to the rotational symmetry axis formed at respective opposite ends thereof. The system also includes a reference beam-irradiating member for irradiating the volume holographic memory with a coherent reference beam having a first wavelength. The system also includes a signal beam-irradiating member for irradiating the volume holographic memory with a coherent signal beam which has the first wavelength and is modulated according to image data, to cause the signal beam to intersect with the reference beam within the volume holographic memory and thereby generate a refractive index grating of a three-dimensional optical interference pattern between the signal beam and the reference beam.

Abstract: A method and device for reproducing information from an optical recording medium having a recording layer containing a photochromic material for recording information and an optical recording medium, the method, device and medium being capable of utilizing the conventional method which reproduces information based on the amount of reflected light from the recording layer by irradiation of the recording layer with information-reproducing light, and being capable of reproducing information without destruction of the information recorded on the recording layer.

Abstract: An optical head has a near-field light generating element generating near-field light; and a beam shaper which shapes an incident beam into a substantially coroidal beam and directs the shaped beam to said near-field light generating element. According to the optical head having the above-described structure, the incident light is shaped into a substantially toroidal beam without being intercepted, incident on the zonal part of the near-field light generating element, and condensed to a minute spot. That is, only the light of the high numerical aperture part is used with efficiency, and the light can be condensed to a minute spot.

Abstract: A recording medium playback device is provided which comprises: a recording medium accommodation unit for accommodating a plurality of recording mediums in a stacked array; a carriage chassis having at least a pickup, a turntable and a pickup moving means, the pickup moving means being adapted to move the pickup in the direction of playing back the recording medium; a moving means for moving the carriage chassis from a standby position to a position between the recording mediums accommodated in the recording medium accommodation unit to play back the recording medium; and a recording medium loading means for loading the recording medium inserted from outside into the recording medium accommodation unit; wherein when the carriage chassis is in the standby position, the pickup is situated on a vertical tangential plane which is tangent to an outer circumferential edge of the recording medium on the carriage chassis side at a point where the outer circumferential edge is intersected by a loading center line of t

Abstract: A self-compensating balancer for a disk player is provided and includes a supporting plate fixed to a rotating shaft of a spindle motor for supplying rotary power to a disk. Pivot pins are installed in the supporting plate and two or more pendulums are arranged around the supporting plate. The pivot pins and pendulums are linked by connectors, such that upon rotation of the shaft, the connectors are elastically transformed and a centroid of the pendulums faces a centroid of the disk, centered around the rotating shaft of the spindle motor, due to a centrifugal force.

Abstract: There are provided an optical recording medium and a method of manufacturing the optical recording medium. The optical recording medium has a pattern of microscopic depressions and projections molded thereon with a high fidelity of replication. The method of manufacturing the optical recording medium comprises the steps of forming a photoresist layer on a substrate; exposing a predetermined area of the photoresist layer formed on the substrate to form a plurality of trains of depressions in the photoresist layer; removing the photoresist layer between the adjoining depression trains to form a master; plating the master with a metal; separating the metal coating to form a master stamper; replicating the master stamper repeatedly an odd number of times to form a mother stamper; replicating the mother stamper to form a resin substrate; and forming at least a light-transparent layer on a surface of the resin substrate on which the mother stamper is replicated.

Abstract: When a malfunction of a master connection 100 is detected by an ATM exchanger, etc., a notice thereof is transmitted to an NMS 40. The NMS 40 is at all times kept monitoring the state within the network. When receiving the notice of the malfunction from the ATM exchanger, the NMS 40 operates on respective cell header translators (HT) 1B, 1C, 3B, and 3C that are associated with the master connection 100 that has malfunctioned. And, the NMS 40 changes the set values of the cell header translators according to the notice of the malfunction. As a result, the ATM cell is bypassed to a bypass connection 200.

Abstract: A data transfer method between a plurality of data transfer apparatuses, is attained by establishing peers between the plurality of data transfer apparatuses to store the established peers in a transfer route configuration data table as transfer route configuration data in each of the plurality of data transfer apparatuses; and by transferring a reception data to specific ones of the plurality of data transfer apparatuses based on the transfer route configuration data in each of the plurality of data transfer apparatuses.

Abstract: The invention proposes a method and a unit for controlling the flow of at least one TCP connection between a sender and a receiver. The method is of the type which consists in controlling, at the level of a given multiplexing node through which TCP segments relevant to the connection pass, a window size parameter contained in acknowledgement segments sent back by the receiver.

Abstract: Methods and apparatus are provided for generating a set of restrictive costs associated with directional paths between selected nodes in a group of nodes of a network system wherein each node in the group is connected by a link to at least one other node in the group, and each link has a pair of directional costs associated therewith such that each link can be considered as a pair of oppositely-directed, unidirectional links each of which extends from a source node to a destination node and has a said directional cost associated therewith. The method allows asymmetric costs, rather than merely symmetric costs, to be considered, and can be applied, for example, to generate the transition matrix for a PNNI peer group.

Abstract: USB 2.0 supports communication in low-speed (LS), full speed (FS) and high speed (HS). In the full speed mode, the wire segment between a hub and a device is terminated via a pull-up resistor 480 on the D+ data line on the downstream end of the segment. In the high-speed mode, both signal wires are terminated by the LS/FS driver 420 generating a single-ended zero via resistors 490. The device emulates a disconnect, while it operates in the high-speed mode, by activating the pull-up resistor 480. Including the D+ pull-up resistor is practically equivalent to an open end, enabling a reliable disconnect detection in the hub using the disconnection envelop detector 460. Detection of an (emulated) disconnect, triggers the reset en enumeration process. This allows the device to report a change in functionality without the user having to physically remove the device from the bus.

Abstract: The present invention discloses a network system for an interactive transmission in first and second directions. The network system includes a plurality of node devices, and a first node device of the node devices can selectively output a signal in the first direction or perform the returning output of a signal. A second node device adjacent to the first node device outputs a signal to the first node device through a channel which is used by the first node device for the returning output, hence the first and second node device are controlled such that those first and second node devices do not use the returning channel of the first node device concurrently.

Abstract: A method and apparatus for controlling the transmission of signals from one or more of a plurality of mobile stations to a base station on a plurality of M multiple access channels is described. A power control information packet formed from a plurality of power control bits is transmitted from the base station to the one or more mobile stations. Each of the power control bits in the power control information packet has a position that is mapped to a selected access channel and to a time offset within the selected access channel. The power control information packet is received at a first mobile station. A message is then transmitted from the first mobile station to the base station on a first access channel and at a first time offset associated with the first access channel.

Abstract: A satellite direct radio broadcast system is provided which assembles bits of broadcast programs into prime rate increments, several of which are assembled into a frame. Frames are divided into symbols which are demultiplexed into alternating ones of a plurality of prime rate channels. The prime rate channels are demultiplexed onto a corresponding number of broadcast frequencies for transmission to a satellite. The satellite payload switches the symbols into time division multiplexed (TDM) data streams. The receivers process the TDM streams using service control headers (SCHs) provided therein by broadcast stations. The SCHs facilitate transmission of different service components within broadcast channel frames, association of a primary broadcast channel with one or more secondary broadcast channels on a frame-to-frame basis, and the transmission of multiframe bit streams, or auxiliary data throughout a broadcast channel that are independent of a service, in contiguous or non-contiguous frames.

Abstract: A method of numbering data packets in a packet-switched telecommunications system which utilizes acknowledged transmission and the telecommunications protocol of which comprises a convergence protocol layer for converting user data packets into convergence protocol packets, and a link layer for transmitting convergence protocol packets as data units and for acknowledging the transmission. A data packet number is defined for the convergence protocol packets to be sent by a counter and the convergence protocol packets to be sent are transmitted to the link layer for transmission without the data packet number. A data packet number is also defined for received convergence protocol packets by means of the counter and an acknowledgement of received convergence protocol packets is transmitted to the transmitter.

Abstract: In a mobile communication system having a plurality of radio packet channels of different transmission rate with each other between a base station and a mobile station, undesirable interference to adjacent cells of adjacent base stations is decreased. Signal quality of a receive signal at a mobile station is measured, and the better said signal quality is, the higher packet channel is assigned. Thus, although signal quality is poor because of long distance between a base station and a mobile station, no increase of transmission power of a base station is requested. Thus, interference to adjacent cells is decreased. When high rate packet channel is selected, short packet transmission time may be assigned so that amount of data transmission is kept uniform in spite of said signal quality.

Abstract: CDMA base-station comprising a transmit stage (2, 4, 7, 9, 10, 11, 12) and a receive stage (3, 5, 8, 13) for communicating with mobile terminals has been provided. The transmit stage comprises a multi carrier power amplifier having at least two independent power modules (10, 11) for transmitting signals on at least one traffic channel (TCH) and control and pilot signals on at least one control channel (CCH). Each power module (10, 11) is capable of being operational although the other power module is non-operational. The at least two power modules are normally operating simultaneously and each is contributing with emitting power. The CDMA base station moreover comprises a control module (16) monitoring the error status of the power modules in the base station.

Abstract: A contents transmission system comprising a first terminal which receives a first code stream produced by compression-encoding contents and has a converter section converting the first code stream into a second code stream having a data size smaller than that of the first code stream, a transmission section transmitting the second code stream, and a second terminal which receives the second code stream transmitted from the first terminal and has a reconstruction section reconstructing the contents by decoding the second code stream.

Abstract: A synchronization establishing and tracking circuit for a CDMA base station is composed of a first spreading code generator, a first correlator, a second spreading code generator, a second correlator, and a phase determining circuit. The first spreading code generator generates a first spreading code sequence. The first correlator calculates first correlation between the first spreading code sequence and a first quasi-coherent signal corresponding to a first received signal received by the CDMA base station. The second spreading code generator generates a second spreading code sequence. The second correlator calculates second correlation between the second spreading code sequence and a second quasi-coherent signal corresponding to a second received signal received by the CDMA base station. The phase determining circuit determines a first phase of the first spreading code sequence based on an added quasi-coherent signal to which the first and second quasi-coherent signals are added.

Abstract: The portable telephone is placed in a waiting state by operating a power key 12. Then, a browser function key (warp key) 8 is pressed, and a little later, a voice key 11 is operated to make transition to an i-warp callable screen. After the beep sound is heard, a screen indicating that the i-warp voice calling is ready appears. Then, the voice calling of URL is practiced. In this case, the “i-warp name” which is the URL name or the name actually spoken by the user in registering the i-warp name with the voice is attached, whereby the URL can be called only by entering the “i-warp name” with the voice.

Abstract: In a GPRS system, a method of a mobile station acquiring an IP network address. The method comprises the steps of: the mobile station generating a link identifier and sending it to a gateway over a wireless link in a network address request together with a request to check if the link identifier is unique; the gateway receiving the network address request and checking if the link identifier is unique; the gateway responding with a network address request response including either the sending a unique link identifier confirmed as being unique or a different unique link identifier; the gateway sending a network prefix to the mobile station; the mobile station combining the interface identifier and the network prefix to generate the IP network address.

Abstract: An IP address duplication detection method using an address resolution protocol is used in a network system in which an IP address duplication diagnosis/detection host and a plurality of check target hosts are connected to a single LAN, all the hosts are respectively assigned MAC addresses as hardware addresses unique to devices without any duplication, and an address resolution protocol aimed at acquiring a MAC address of a remote device from an IP address is installed in each host. In this method, an ARP request packet containing a check target IP address in the same subnet as for the IP address duplication diagnosis/detection host is sent out from the IP address duplication diagnosis/detection host to each of the check target hosts through the LAN. IP address duplication is detected depending on whether an ARP reply packet as a response packet for the ARP request packet is returned from each of the check target hosts to the IP address duplication diagnosis/detection host through the LAN.