Patents by Inventor Osamu Isaji

Osamu Isaji has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20050275585
    Abstract: The present invention relates to a radar apparatus that uses a plurality of transmitting/receiving antennas A1-A4 and receives a reflected wave, of a transmitted wave, reflected from a target. By utilizing the property that the path of the transmitted wave from an antenna A1 and its reflected wave and the path of the transmitted wave from the next selected antenna A2 and its reflected wave share the same spatial system, and therefore that both received signals have the same characteristics in terms of frequency and phase, a judgment is made as to whether there exists any difference between the receiving characteristics of the antennas, and the received signal is corrected in accordance with the result of the judgment. It is also possible to judge the presence or absence of a change in the characteristic of each antenna, and apply a correction accordingly, even during the normal operation of the apparatus.
    Type: Application
    Filed: June 6, 2005
    Publication date: December 15, 2005
    Applicant: Fujitsu Ten Limited
    Inventors: Nobukazu Shima, Osamu Isaji
  • Patent number: 6954174
    Abstract: A radar apparatus for a vehicle includes a casing, a correction member, and a selection indication. The casing includes a functional portion, which performs searching, and a reference surface. The correction member includes a plurality of correction surfaces. The selection indication indicates which one of the correction surfaces and the reference surface an attachment-direction adjustor is to be placed on during an attachment operation of the radar apparatus to the vehicle.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: October 11, 2005
    Assignee: Fujitsu Ten Limited
    Inventors: Osamu Isaji, Hideki Kajioka, Norihiko Hatanaka
  • Publication number: 20050206556
    Abstract: In a radar apparatus, a receiving antenna includes a plurality of antenna elements, each receiving, as a reception signal, radio waves emitted into space and reflected off a target object. An analog signal is obtained by downconverting and putting a bandwidth constraint on the reception signal, and is then converted to a digital signal. Based on the digital signal, a signal processing unit detects the bearing of the target object. The signal processing unit performs processing based on outputs of two sets of the antenna elements.
    Type: Application
    Filed: March 3, 2005
    Publication date: September 22, 2005
    Applicant: FUJITSU TEN LIMITED
    Inventor: Osamu Isaji
  • Publication number: 20050184903
    Abstract: In an FM-CW radar system, a frequency modulating said modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.
    Type: Application
    Filed: August 22, 2003
    Publication date: August 25, 2005
    Inventor: Osamu Isaji
  • Patent number: 6933883
    Abstract: A radar mount direction alignment device to be used for aligning the transmit/receive direction of a radar device 2D mounted on a member on which a radar device is to be mounted, such as a vehicle 1. The radar mount direction alignment device has receiving sections b9, b10 for receiving a signal emitted from the radar device 2D, and transmission sections a9, a10 for transmitting a signal to the radar device 2D. The radar mount direction alignment device has the function of emitting, toward the radar device 2D, a signal which, upon receipt of a signal output from the radar device 2D, behaves as if having been received at and reflected from a position farther from the radar device 2D than a distance between the radar device 2D and the radar mount direction alignment device.
    Type: Grant
    Filed: February 7, 2002
    Date of Patent: August 23, 2005
    Assignee: Fujitsu Ten Limited
    Inventor: Osamu Isaji
  • Patent number: 6927726
    Abstract: A radar suppresses a dc component so as to improve the precision in processing a signal that belongs to a low-frequency band. The radar comprises a mixer that mixes a transmitted signal and a received signal, and an A/D converter that analog-to-digital converts an output signal of the mixer. The radar further includes: a removing unit that removes a dc voltage component by subtracting a predetermined removal voltage value from output data of the A/D converter; and an analyzing unit that Fourier-transforms data, which has the dc voltage component removed therefrom by the removing unit, so as to analyze the data.
    Type: Grant
    Filed: March 1, 2004
    Date of Patent: August 9, 2005
    Assignee: Fujitsu Ten Limited
    Inventor: Osamu Isaji
  • Publication number: 20050083995
    Abstract: A radar apparatus includes a transmission section, a delay device, a reception section, a switch control section, a switching frequency detection section, and a relative distance calculation section. The transmission section transmits a signal wave, which is spectrum spread by using a spread code. The delay device gives delay to the spread code. The reception section receives a wave reflected by an object and spectrum despreads the reflected wave with using the delayed spread code to output a despread signal. The switch control section switches at a switching frequency an operation of at least one of the transmission section, the reception section, and the delay device. The switching frequency detection section detects the switching frequency from the despread signal. The relative distance calculation section calculates a distance to the object based on a detection result provided by the switching frequency detection section and an amount of the delay.
    Type: Application
    Filed: September 23, 2004
    Publication date: April 21, 2005
    Applicant: FUJITSU TEN LIMITED
    Inventors: Kanako Honda, Osamu Isaji
  • Patent number: 6859168
    Abstract: Disclosed is a radar apparatus which receives a transmitted signal reflected from an object by switching between a plurality of antennas, wherein the plurality of antennas are divided into a plurality of groups, and at least one of the plurality of antennas contained in each of the groups is a common antenna.
    Type: Grant
    Filed: January 14, 2004
    Date of Patent: February 22, 2005
    Assignee: Fujitsu Ten Limited
    Inventor: Osamu Isaji
  • Publication number: 20050007271
    Abstract: A modulation signal generation circuit performs frequency modulation of a VCO with a triangular wave for operation as an FM-CW radar. A signal processing circuit gives a modulation signal for detection generated from the modulation signal generation circuit to the VCO. A high-frequency signal subjected to frequency modulation in the VCO is transmitted as a radio wave from a transmission antenna and is reflected on a target and the reflected radio wave is received at a reception antenna. The reception signal and the high-frequency signal are mixed by a mixer to provide a beat signal and frequency shift corresponding to a voltage V1 is detected from the frequency of the beat signal. If the voltage V1 of the modulation signal for detection is switched, the frequency shift corresponding to different voltage V1 can be provided and the frequency modulation characteristic can be detected.
    Type: Application
    Filed: July 18, 2003
    Publication date: January 13, 2005
    Applicant: Fujitsu Ten Limited
    Inventor: Osamu Isaji
  • Patent number: 6831595
    Abstract: Disclosed is a radar apparatus equipped with a function for detecting an abnormality of modulation width. Distance rt2 at time t2 is calculated from the values of the distance Rt1 and the relative velocity Vt1 measured at time t1 and the elapsed time t2−t1, and the difference relative to the actual measured value Rt2 is compared with a threshold value C1. If the difference relative to the actual measured value exceeds the threshold value C1, the modulation width is judged to be abnormal.
    Type: Grant
    Filed: March 3, 2004
    Date of Patent: December 14, 2004
    Assignee: Fujitsu Ten Limited
    Inventor: Osamu Isaji
  • Publication number: 20040246168
    Abstract: The present invention relates to a radar device for forming multi-beams in multiple channels from reflected waves of a transmitted wave by using a minimum number of antennas. The device has: antennas used for both transmission and reception A1-A4; transmission/reception switching means 5 of each antenna; a transmitter 2; and a receiver 4 for receiving the reflected waves of the transmitted wave. The ratio of the distance between adjacent antennas A1 and A2 to the distance between adjacent antennas A2 and A3 or A3 and A4 is 1:2. The transmitted signal is transmitted from each of the antennas selected sequentially and the received signal is processed by DBF in a signal processing controller 1, wherein eleven channels can be implemented by using four antennas and a space for six antennas.
    Type: Application
    Filed: February 12, 2004
    Publication date: December 9, 2004
    Inventor: Osamu Isaji
  • Patent number: 6825799
    Abstract: Disclosed is a radar apparatus equipped with a function for detecting an abnormality of noise floor level. An abnormality of noise floor level is detected by measuring the level in a region not lower than 60 kHz when FM modulation is stopped or modulation width is made infinitely small by instruction from a CPU to a modulating signal generator.
    Type: Grant
    Filed: March 3, 2004
    Date of Patent: November 30, 2004
    Assignee: Fujitsu Ten Limited
    Inventor: Osamu Isaji
  • Publication number: 20040233094
    Abstract: A radar apparatus for a vehicle includes a casing, a correction member, and a selection indication. The casing includes a functional portion, which performs searching, and a reference surface. The correction member includes a plurality of correction surfaces. The selection indication indicates which one of the correction surfaces and the reference surface an attachment-direction adjustor is to be placed on during an attachment operation of the radar apparatus to the vehicle.
    Type: Application
    Filed: May 21, 2004
    Publication date: November 25, 2004
    Applicant: FUJITSU TEN LIMITED
    Inventors: Osamu Isaji, Hideki Kajioka, Norihiko Hatanaka
  • Publication number: 20040222919
    Abstract: Disclosed is a radar apparatus equipped with a function for detecting an FM-AM conversion noise peak. When the direction of radiation is swept, any peak whose level remains substantially unchanged is judged to be a peak due to FM-AM conversion noise. Further, when FM modulation is stopped, any peak appearing in a region not lower than 50 kHz is judged to be a noise peak.
    Type: Application
    Filed: March 3, 2004
    Publication date: November 11, 2004
    Inventor: Osamu Isaji
  • Publication number: 20040207552
    Abstract: Disclosed is a radar apparatus which receives a transmitted signal reflected from an object by switching between a plurality of antennas, wherein the plurality of antennas are divided into a plurality of groups, and at least one of the plurality of antennas contained in each of the groups is a common antenna.
    Type: Application
    Filed: January 14, 2004
    Publication date: October 21, 2004
    Inventor: Osamu Isaji
  • Publication number: 20040174293
    Abstract: Disclosed is a radar apparatus equipped with a function for detecting an abnormality of noise floor level. An abnormality of noise floor level is detected by measuring the level in a region not lower than 60 kHz when FM modulation is stopped or modulation width is made infinitely small by instruction from a CPU to a modulating signal generator.
    Type: Application
    Filed: March 3, 2004
    Publication date: September 9, 2004
    Inventor: Osamu Isaji
  • Publication number: 20040174292
    Abstract: Disclosed is a radar apparatus equipped with a function for detecting an abnormality of modulation width. Distance rt2 at time t2 is calculated from the values of the distance Rt1 and the relative velocity Vt1 measured at time t1 and the elapsed time t2−t1, and the difference relative to the actual measured value Rt2 is compared with a threshold value C1. If the difference relative to the actual measured value exceeds the threshold value C1, the modulation width is judged to be abnormal.
    Type: Application
    Filed: March 3, 2004
    Publication date: September 9, 2004
    Inventor: Osamu Isaji
  • Publication number: 20040174291
    Abstract: A radar suppresses a dc component so as to improve the precision in processing a signal that belongs to a low-frequency band. The radar comprises a mixer that mixes a transmitted signal and a received signal, and an A/D converter that analog-to-digital converts an output signal of the mixer. The radar further includes: a removing unit that removes a dc voltage component by subtracting a predetermined removal voltage value from output data of the A/D converter; and an analyzing unit that Fourier-transforms data, which has the dc voltage component removed therefrom by the removing unit, so as to analyze the data.
    Type: Application
    Filed: March 1, 2004
    Publication date: September 9, 2004
    Inventor: Osamu Isaji
  • Patent number: 6664919
    Abstract: The present invention relates to a radar device and, particularly, to a radar device mounted on a vehicle to be used for a collision alarm and the like. The invention provides a radar device that has a unit for removing the FMAM noise without lowering the signal detection sensitivity. The radar device transmits a frequency modulation signal by switching the frequency modulation signal with a first switching signal, receives a signal reflected from a target object, switches the reception signal with a second switching signal, mixes the switched reception signal with the transmission signal, and further mixes the mixed signals with a third switching signal thereby to obtain a beat signal. The radar device obtains a distance to the target object and a relative speed of the target object from the beat signal.
    Type: Grant
    Filed: December 6, 2002
    Date of Patent: December 16, 2003
    Assignee: Fujitsu Ten Limited
    Inventor: Osamu Isaji
  • Patent number: 6657582
    Abstract: As to a beat signal of a received wave, for instance, a plurality of FFT-based frequency spectra of every FM rise zone are accumulated in an accumulation unit. A judgment unit judges a valley section from the plurality of frequency spectra accumulated. A peak frequency extraction unit acquires, as beat frequencies of different targets, respective beat frequencies of peak sections located at both sides of the valley sections judged.
    Type: Grant
    Filed: April 1, 2002
    Date of Patent: December 2, 2003
    Assignees: Fujitsu Limited, Fujitsu Ten Limited
    Inventors: Tetsuo Seki, Osamu Isaji