Patents Assigned to Iwatsu Electric Co., Ltd.
  • Patent number: 5571966
    Abstract: A nondestructive inspection method predicts the lifetime of a measured object. A measured object is made to vibrate, and there is obtained a frequency difference .increment.f between a frequency of a nth-order spectrum and a frequency of a (n+1)th-order spectrum of any one of longitudinal waves, transverse waves and distortional waves generated in the measured object when the measured object is made to vibrate. It is possible to predict lifetime of the measured object by detecting degree of deterioration of the measured object based on a relational curve representing the frequency difference .increment.f and the circumstances of use of the measured object.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: November 5, 1996
    Assignee: Iwatsu Electric Co., Ltd.
    Inventor: Kiyoshi Tsuboi
  • Patent number: 5548638
    Abstract: An audio teleconferencing apparatus which permits two-way communications between more than two parties without the necessity of complete switching and does not allow a loss to increase in a communication channel of a particular speaker. The audio teleconferencing apparatus further comprises more than two line interface circuits, each provided with a voice activity detector for detecting voice activity in a received speech signal, a received-speech variable loss for inserting a loss into a speech receiving path when the received speech signal is voice non-active, and a sending-speech variable loss for inserting a loss in a speech signal transmission or sending path when the speech to be sent is voice-active, whereby a certain loss is inserted in any four-wire multiplex loop in the line interface circuit.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: August 20, 1996
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Naoyuki Yamaguchi, Tohru Abe
  • Patent number: 5460912
    Abstract: The present invention is to provide an electrophotography type lithographic form plate having a high sensitivity and a superior photosensitive characteristic as a photosensitive material for a semiconductor laser beam as well as having an excellent printability as a lithographic form plate. The form plate comprises an electroconductive support member and a photosensitive layer formed thereon and containing a sensitizer mainly consisting of zinc oxide and a binder resin, wherein the sensitizer is at least one compound selected from a group of dye compounds represented by the following general formula (I), and a total acid value of the binder resin is within a range of 3.0 through 10.0. ##STR1## wherein, in the above formula, n represents 2 or 3; R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represent hyrogen atoms, lower alkyl groups, lower alkoxy groups, or halogen atoms, and X-represents an acid anion.
    Type: Grant
    Filed: June 4, 1993
    Date of Patent: October 24, 1995
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Hideyuki Yamamoto, Kazumasa Hijikata
  • Patent number: 5448339
    Abstract: The present invention is aimed at providing a control system for a thermal fixing apparatus having an excellent fixing ability even at an initial stage of a copying process when applied to a high speed copying machine and ensuring a longer life of a surface layer member of the roller, while maintaining the economical benefit derived from the provision of a heater only in a heat roller. The fixing apparatus includes a heater roller 101 and a press roller 102. At least one of the rollers is driven by a motor 103 while in contact with the other so that both rollers are rotated together. A surface temperature of the heater roller 101 is detected by a thermometer 104 and is used for controlling a heating level of a heater 106 by a controller 105.
    Type: Grant
    Filed: January 27, 1993
    Date of Patent: September 5, 1995
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Norio Kokaji, Michiaki Yokozawa, Yuuichi Nakagawa, Mamoru Nishiguchi, Seiichi Hayashi
  • Patent number: 5396484
    Abstract: In a mobile communication system in which signals are temporally compressed into time slots of a frame structure, a composite signal such as a telephone signal or data signal is hybrid-modulated using the same radio carrier wave, whereby diversity transmission/reception are available. The telephone signal is frequency-modulated using a single time slot of a single radio communication channel which has been allocated between a mobile transceiver and a radio base station. The frequency-modulated signal is again amplitude-modulated by the same telephone signal so that diversity transmission/reception is available.
    Type: Grant
    Filed: July 16, 1992
    Date of Patent: March 7, 1995
    Assignee: Iwatsu Electric Co., Ltd.
    Inventor: Sadao Itoh
  • Patent number: 5335047
    Abstract: A printing-plate making apparatus is constructed such that a mode selecting switch adapted to change a master supplying process depending on properties of a master X is disposed on a housing 1 of the printing-plate making apparatus and various conditions, e.g., a master supplying process, locking member 4 for a master supplying roller 3, a temperature preset for a panel heater 33 and a compressing force given by press rollers 35a and 35b are automatically changed to optimal conditions corresponding to masters selected by the mode selecting switch. The printing-plate making apparatus is provided with a master heating switch on the housing 1 of the printing-plate making apparatus and when the master heating switch is actuated, applying of a certain voltage to at least a charger is stopped so that the panel heater 33 arranged at a fixing step is kept in the heated state so as to serve as a master heating unit.
    Type: Grant
    Filed: January 15, 1993
    Date of Patent: August 2, 1994
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Masanori Kai, Satoshi Okabe, Nobuyoshi Hatori, Toshio Koike, Tamio Iwamoto
  • Patent number: 5329331
    Abstract: A post-processing apparatus for washing off a photosensitive layer in a non-image area of an organic photoconductive master plate that has been prepared on a platemaker through the steps of exposure, development and fixing. The apparatus including a swelling/wetting section for rendering the photosensitive layer in the non-image area swollen and wet; a stripping section for stripping and removing the photosensitive layer; a cleaning section for washing the photosensitive layer with water; solution receiving tanks provided for the respective sections for receiving processing solution; spray pipes provided along a width of the master plate for spraying the processing solution from the solution receiving tanks respectively associated with the swelling/wetting, the stripping and the cleaning sections; and a detector for detecting a temperature of the processing solution. The detector being provided in a rear end of a fluid passageway of the spray pipe in the swelling/wetting section.
    Type: Grant
    Filed: January 15, 1993
    Date of Patent: July 12, 1994
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Nobuyoshi Hatori, Toshio Koike
  • Patent number: 5311247
    Abstract: A plate making machine of a compact size has a mechanism for dealing with jamming, by which jammed master paper can be easily removed, and the maintenance of an exposure stage and a supply transfer system can be performed without disassembling the machine body. The supply transfer system for feeding the master paper X to the exposure stage 9 is provided in a generally horizontal direction at an upper portion of the plate making machine body 1. A lamp house 13 for projecting the original image is provided above the exposure stage 9. An exposure plate 24 is provided at the exposure stage 9, and the exposure plate is tiltable about tilting shaft 25 provided at the side thereof opposite to the supply transfer system. An endless feed belt 33 for feeding and discharging the master paper X relative to the exposure plate 24 is provided in surrounding relation to the exposure plate 24.
    Type: Grant
    Filed: September 16, 1992
    Date of Patent: May 10, 1994
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Nobuyoshi Hatori, Toshio Koike
  • Patent number: 5296944
    Abstract: An image scanner is comprised of a light source for illuminating an original document, an image sensor for receiving a reflected light from the original document and converting the same into an output signal of image data, a device for relatively moving the original document and the image sensor, an iris mechanism provided on an optical path between the original document and the image sensor, a reference reflection plane provided such that a light from the light source is reflected and the reflection light becomes incident on the image sensor, a comparing circuit for comparing a level of an output signal from the image sensor with a reference level when the image sensor receives the light from the reference reflection plane, and a device for correcting a dynamic range of the image scanner by controlling the iris mechanism on the basis of the compared output.
    Type: Grant
    Filed: June 14, 1991
    Date of Patent: March 22, 1994
    Assignee: Iwatsu Electric Co. Ltd.
    Inventors: Satoshi Suzuki, Susumu Takahashi, Yoshihiro Kuwata, Yasuo Morinaga
  • Patent number: 5289206
    Abstract: An XY plotter includes a pair of grip and pinch rollers for feeding recording paper in one direction while gripping the recording paper therebetween, a pen carriage arranged to be movable in the direction perpendicular to the one direction, a pen supported by the pen carriage for performing recording on the recording paper, a grip roller shaft provided parallel to the traveling direction of the pen carriage, the grip roller shaft having a non-circular section, a movable stand arranged so that the position thereof is adjustable in the longitudinal direction of the grip roller shaft, and the grip and pinch roller including a movable partial grip roller and a pinch roller, the movable partial grip roller being mounted on the movable stand so that the movable partial grip roller is not rotatable relative to the grip roller shaft but is movable on the grip roller shaft in the longitudinal direction thereof, the pinch roller being supported on the movable stand so that the pinch roller is made to come into contact
    Type: Grant
    Filed: October 9, 1991
    Date of Patent: February 22, 1994
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Tadao Ishikawa, Nazuhiko Sanda, Ryoji Hirakata, Kiyokatsu Sugiyama
  • Patent number: 5280521
    Abstract: A portable telephone system is disclosed in which a plurality of i-th class exchanges, which accommodate key service units of a plurality of portable telephone sets present in each service area, and at least one (i+1)th class exchange which accommodates the plurality of i-th class exchanges through junction lines, are stratified to form an exchange system so that i=1, 2, 3, . . . , and so that the (i+1)th class exchange covers all service areas. The exchange system has a function whereby information which specifies the home area of each portable telephone set and the portable telephone set in distinction from each other is registered in the i-th class exchange and the (i+1)th class exchange, which administer the home area.
    Type: Grant
    Filed: February 24, 1992
    Date of Patent: January 18, 1994
    Assignee: Iwatsu Electric Co., Ltd.
    Inventor: Sadao Itoh
  • Patent number: 5249174
    Abstract: A mobile body communication method using a gateway exchanging unit for exchanging a communication between a radio base station and a plurality of mobile radio units, the radio station constituting a service area covering a plurality of zones, the mobile radio units moving across the plurality of zones and using a radio channel to communicate with the radio base station, the radio channel carrying time-division time-compressed signals in time slots constituting a frame, the method comprising the steps of, determining a level of a radio signal to be used in a communication between the radio base station and the mobile radio unit based on a non-simultaneous load advantage obtained by the time-division time-compressed signals, transmitting a signal to be transmitted while causing an amplitude distribution thereof to be compressed within a desired range by a syllabic compressor, and subjecting a received signal to an amplitude distribution recovering process by a syllabic expander.
    Type: Grant
    Filed: March 6, 1991
    Date of Patent: September 28, 1993
    Assignee: Iwatsu Electric Co., Ltd.
    Inventor: Sadao Itoh
  • Patent number: 5228035
    Abstract: A synchronizing system in a digital communication line comprises a plurality of local switches for storing at least one digital line and monitoring a first piece of busy information when a clock source is already present, the local switches, if a first new clock source occurs while the first busy information is indicating no busy state, being capable of transmitting a master right request to turn the busy information to the busy state and to specify the first new clock source as a master clock and, on receiving a master right specification with respect to the master right request, being capable of outputting the first new clock source as the master clock; and a master switch connected to the plurality local switches in a star manner, by a link transmission line for transmitting control information including the master clock, master right request and master right specification, for monitoring a second piece of busy information indicating a busy state, the master switch, if a second new clock source occurs whil
    Type: Grant
    Filed: October 29, 1991
    Date of Patent: July 13, 1993
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Akira Hirato, Yuji Kondo, Hideharu Omori, Naoyuki Yamaguchi, Koichi Ichimura, Yoshihiro Kawata
  • Patent number: 5219693
    Abstract: Disclosed is a printing plate, for an electrophotographic process, which comprises an electroconductive support and a photosensitive layer formed on the electroconductive support, in which the photosensitive layer is formed by incorporating (a) a trisazo pigment represented by the general formula (I) and (b) at least one member selected from perynone pigments and anthanthrone pigments as photoconductive substances and (c) at least one electron donor substance as a sensitizer in an alkali-soluble binder resin. This printing plate has a high sensitivity and a printing image having a high quality is formed on the printing plate without contamination of the non-image area due to the electrophotography, and prints having a high-quality image can be obtained by using this printing plate.
    Type: Grant
    Filed: October 29, 1990
    Date of Patent: June 15, 1993
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Akio Akao, Seiji Kuwakubo, Takao Soma, Takeo Kadoi
  • Patent number: 5213919
    Abstract: Disclosed is an eluting solution for eluting a non-image area of an electrophotographic printing plate having a toner image formed and fixed thereon by electrophotography, to expose a hydrophilic substrate or a substrate that can be rendered hydrophilic. This eluting solution is an aqueous solution containing at least an alkali chelating agent.
    Type: Grant
    Filed: November 5, 1990
    Date of Patent: May 25, 1993
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Seiji Kuwakubo, Akio Akao, Takao Soma, Takeo Kadoi
  • Patent number: 5210546
    Abstract: In a magnetic printing machine including at least two recording frequency generators which generate at least two recording frequencies with close each other, a recording current applied to a recording head for the same gradation level is switched among at least two recording frequencies every time a predetermined number of pixels are recorded.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: May 11, 1993
    Assignee: Iwatsu Electric Co., Ltd.
    Inventor: Norio Kokaji
  • Patent number: 5210786
    Abstract: A portable telephone system is disclosed in which a plurality of i-th class exchanges, which accommodate key service units of a plurality of portable telephone sets present in each service area, and at least one (i+1)th class exchange which accommodates the plurality of i-th class exchanges through junction lines, are stratified to form an exchange system so that i=1, 2, 3, . . . , and so that the (i.1)th class exchange covers all service areas. The exchange system has a function whereby information which specifies the home area of each portable telephone set and the portable telephone set in distinction from each other is registered in the i-th class exchange and the (i+1)th class exchange, which administer the home area.
    Type: Grant
    Filed: May 10, 1991
    Date of Patent: May 11, 1993
    Assignee: Iwatsu Electric Co. Ltd.
    Inventor: Sadao Itoh
  • Patent number: 5206543
    Abstract: In a sampling gate circuit, a broadband and high-precision sampling gate circuit is realized by further employing first and second equivalent sampling networks which are equal to a sampling operation by a first sampling gate circuit. The first and second equivalent sampling networks compensate for distortions in the signal output by the first sampling gate circuit and allow an input waveform to be reproduced at high precision. The output from the first sampling gate circuit is input to a positive terminal of a differential amplifier. The outputs from the first and second equivalent sampling networks are input into two respective negative inputs of a differential amplifier, to cancel the distortions of the signal output from the first sampling gate circuit and input to the positive terminal of the differential amplifier. This device may find particular application in sampling type oscilloscopes or the like.
    Type: Grant
    Filed: June 16, 1992
    Date of Patent: April 27, 1993
    Assignee: Iwatsu Electric Co., Ltd.
    Inventors: Shintaro Takita, Masahiro Ohtaka, Kensuke Kobayashi
  • Patent number: 5179860
    Abstract: A defect detecting method for detecting whether or not an object to be measured has a defect includes the steps of vibrating the object to be measured, picking up the vibration, and detecting that a spectrum of the characteristic vibration of the object to be measured is separated into two portions. Also, a defect detecting apparatus includes a vibrator for vibrating an object to be measured, a vibration detector for picking up a vibration of the object to be measured and for converting the vibration into an electric signal, and computation process and determination equipment for receiving the electric signal from the detector, for analyzing a spectrum of a characteristic vibration of the object to be measured, and for determining whether a defect is present or absent depending on whether a spectrum of a defect of the object to be measured is present or absent.
    Type: Grant
    Filed: February 24, 1992
    Date of Patent: January 19, 1993
    Assignees: Iwatsu Electric Co., Ltd., Honda Giken Kogyo Kabushiki Kaisha
    Inventor: Kiyoshi Tsuboi
  • Patent number: 5159596
    Abstract: A mobile communication system based on a time division communication system comprising: mobile radio units for transmitting and receiving time-compressed and segmented signals by a radio channel allocated to time slots; radio base stations to which a communicable time slot is previously allocated so as to communicate using only a specific time slot of those time slots of the radio channel when the mobile radio units moves across one of service areas that are disposed so as to overlap at least partially with one another, the time slot allocated to one radio base station being different from that allocated to another radio base station; and gateway exchange units for exchanging communications between the mobile radio units and the radio base stations and for connecting the radio base stations to a public switched telephone network.
    Type: Grant
    Filed: June 26, 1990
    Date of Patent: October 27, 1992
    Assignee: Iwatsu Electric Co., Ltd.
    Inventor: Sadao Itoh