Abstract: An optical head apparatus includes an objective lens which receives a light beam from a light source and condenses the light beam onto the optical recording medium. A photo-detector has plurality of photo-detecting planes disposed orthogonal to an optical axis of the reflected light beam and symmetrical with respect to the optical axis, and detects the light beam reflected by the optical recording medium. Each of the photo-detecting plane is divided into a plurality of divided areas by a plurality of dividing lines which are symmetrically divide the photo-detecting planes with respect to the optical axis.

Abstract: An optical information recording/reproducing apparatus for optically recording/reproducing information by irradiating a track on a recording medium with a light comprises: a detecting circuit, a tracking error signal producing circuit, and a tracking control circuit. The detecting circuit selectively detects a circular area having a diameter smaller than a diameter of a light beam reflected from the recording medium and obtains an output signal corresponding to the detected circular area. The tracking error signal producing circuit produces, from the output signal of the detecting circuit, a tracking error signal indicating a shift in a position of a light beam irradiated on the recording medium in a track width direction. The tracking control circuit controls an irradiation position of a light beam irradiated on the recording medium in the track width direction based on the tracking error signal.

Abstract: The sewing machine comprises two hooks 27a and 27b which are respectively disposed in such a manner as to correspond to two needles 7 and 7 provided in the present sewing machine, hook gap adjusting device 33-35 respectively for changing the gap between the two hooks 27a and 27b, drive device 36 for driving the hook gap adjusting device 33-35, transmission device 37-41 respectively for transmitting the driving of the drive device 36 to the hook gap adjusting device 33-35, and control device 50 for controlling the driving of the drive device 36 to thereby control the above gap between the two hooks, whereby the sewing machine is able to move the hooks 27a and 27b easily only by driving the drive device.

Abstract: In a movable radio terminal device, a switching circuit connects, in response to one of first and second matching switching control signals, an antenna 2 to one of first and second impedance matching circuits. The controlling unit produces and supplies, at every predetermined time interval, the first and second matching switching control signals to the switching circuit, respectively, to make a memory device memorize, as first and second level signals having first and second level values, detected level signals from a level detecting circuit when the switching circuit connects the antenna to the first and second impedance matching circuits, respectively, when the detected level value from the level detecting circuit is smaller than one of the first and second level values that corresponds to the second greatest level value in the first and second level values, and when the controlling unit is supplied with a human body contact discriminating signal from a human body contact discriminating circuit.

Abstract: In data transmission from a base station to a mobile station, a received signal strength is monitored at the base station and the mobile station and, when the received signal strength reduces to less than a predetermined level, the base station concurrently transmits a plurality of radio signals each having a different frequencies and conveying the same data. At the mobile station, the original data is reproduced from the radio signals received from the base station.

Abstract: An optical information recording/reproducing apparatus for optically recording/reproducing information by irradiating a track on a recording medium with a light comprises: a detecting circuit, a tracking error signal producing circuit, and a tracking control circuit. The detecting circuit selectively detects a circular area having a diameter smaller than a diameter of a light beam reflected from the recording medium and obtains an output signal corresponding to the detected circular area. The tracking error signal producing circuit produces, from the output signal of the detecting circuit, a tracking error signal indicating a shift in a position of a light beam irradiated on the recording medium in a track width direction. The tracking control circuit controls an irradiation position of a light beam irradiated on the recording medium in the track width direction based on the tracking error signal.

Abstract: An optical head device adapted to be optically coupled to an optical disk includes a light-source laser and an objective lens optically coupled thereto. This lens receives an output light of the light source, and causes it to be projected onto the optical disk to form a focused spot thereon. Photodetectors are optically coupled to the lens in one optical path so that they are responsive to a light component which is reflected from the optical disk toward the photodetectors by way of the objective lens. A beam-shaping prism is located between the lens and a group of the light source and the photodetectors in the optical path. When the laser output light travels toward the lens, the prism reshapes the light into a predetermined isotropic beam profile. When the reflected light from the optical disk propagates reversely along the same optical path to enter the beam-shaping prism, this prism permits such an incident light to pass through itself toward the photodetectors.

Abstract: Disclosed is a transmission restricting system which has a transmission interruption controlling means for generating and radiating a magnetic field pattern including a command code to command the transmission interruption to a radio communication terminal equipment in a radio-wave transmission-prohibited area, the transmission interruption controlling means being disposed at the entrance or exit of the radio-wave transmission-prohibited area; a transmission interruption releasing means for generating and radiating a magnetic field pattern including a command code to command the releasing of transmission interruption to the radio communication terminal equipment in the radio-wave transmission-prohibited area, the transmission interruption releasing means being disposed at the entrance or exit of the radio-wave transmission-prohibited area; and a radio communication terminal equipment comprising means for detecting a magnetic field pattern including a command code to command the transmission interruption or th

Abstract: A belt-loop supply apparatus incorporating a tape supply unit which is capable of supplying, to a tape cutting position, an elongated tape for forming a belt loop; a tape cutting unit for cutting the tape supplied to the tape cutting position to form a belt loop having a predetermined length; and a belt loop supply unit incorporating a pair of bending members for holding two ends of the cut belt loop, bending the two ends of the belt loop toward the central portion of the belt loop and supplying the belt loop, the belt-loop supply apparatus having: a moving unit for controlling moving speed of the bending members to move the bending members to a sewing position of a machine.

Abstract: In a data packet transmission method and an apparatus for realizing the method, data packet transmission/reception is performed between communication apparatuses each having a CPU for controlling an entire operation of the apparatus. An operating efficiency of the CPU of the communication apparatus on a reception side is detected when a data packet transmission/reception request is generated. An optimum data packet length for reception of a data packet is determined in correspondence with the detected operating efficiency, and the communication apparatus on a transmission side is informed of the optimum data packet length. The data packet to be transmitted is assembled to have the optimum data packet length, and the data packet is transmitted.

Abstract: A battery built-in wireless ID card unit including a magnetic field detection section which generates an electromotive force from a received magnetic field to turn on a power switch of a built-in battery, and a control section which transmits an ID code by radio after the power switch is turned on, thereby turning off the power switch.

Abstract: A data transmitter-receiver for reducing high-frequency noise which leads to a cause of performance deterioration of a radio instrument, and for eliminating dissipation current. The data transmitter-receiver transmits transmitting data to a modulator-demodulator connected to a radio instrument, and receives receiving data from the modulator-demodulator. A terminal controlling section 3 of the data transmitter-receiver performs data processing on the receiving data, thus outputting to a data-terminal, and performs data processing transmitting signal from the data-terminal, thus generating the receiving data.

Abstract: A radio channel estimation method includes a combination of BER (bit error rate) estimation and RSSI (received signal strength indicator) estimation. The RSSI and the BER are detected from a received signal through a radio channel, and then the radio channel is estimated based on the RSSI and the BER. A quality of the radio channel is estimated to be degraded unless the BER meets a first criterion and the RSSI meets a second criterion. The BER meets the first criterion when an average number of times during a time period that the BER exceeds a maximum value is smaller than a first threshold value. The RSSI meets the second criterion when an average number of times during a time period that the RSSI is below a minimum value is smaller than a second threshold value.

Abstract: In a case where tracking control is carried out by a lens actuator in performing a tracking pull-in operation in which tracking control is started in the state where tracking control is out of operation, the tracking control circuit brings control into stable tracking control by moving the light spot onto a groove on the optical disc. After that, when tracking onto a land is needed, the tracking control circuit moves the light spot onto the land. This enables a pull-in action toward a stable tracking operation.

Abstract: An RSSI detector 2 detects the electric field level of a received signal, and a transmission rate determiner 5 determines an initial transmission rate value from the detected electric field level. A radio unit 1 transmits the determined initial value to a base station 20. In response thereto, the base station 20 transmits a control signal at the assigned initial transmission rate value. A bit error rate value detector 4 detects a bit error rate of the control signal, and a transmission rate determiner 5 finely regulates the initial value according to the detected bit error rate. An optimal transmission rate is thus determined.

Abstract: An infra-interface section 15 in a radio modem has a function of radio interfacing with a plurality of radio lines. An interface section 16, conforming to the PCMCIA standard, connects with a data terminal unit to which this radio modem is to be connected. A memory section 17 stores information transmitted or received by the infra-interface section 15. A display section 14 displays the stored transmit/receive information. A control section 18 controls all these sections. By having transmit/receive information, when data are transmitted or received via radio lines, stored into the memory section 17 and then displayed in the display section 14, the user of the terminal is enabled to recognize, by locking at the display section, the plurality of conditions of transmission/reception on a real time basis without confusing them with one another.

Abstract: A primary optical disk recording apparatus comprises a first light source for recording a signal on a primary optical disk, an objective lens for converging a light beam from the first light source on the primary optical disk, a second light source for detecting a focus error between the objective lens and the primary optical disk, and a controller for detecting a reflection light beam from the first light source, which is reflected from the primary optical disk, while the signal is being recorded on the primary optical disk, and for subjecting a signal of the reflection beam to an arithmetic operation process, thereby detecting a first focus error signal and controlling the focus error on the basis of the first focus error signal.

Abstract: An optical head has a first light source for emitting a first light beam having a first wavelength, a second light source for emitting a second light beam having a second wavelength larger than the first wavelength, and an optical system for guiding the first and second light beams to an optical disc and guiding light beams reflected by the optical disc to an optical detector. The optical system comprises an objective lens, a beam splitter for reflecting the first light beam and the S-polarized component of the second light beam and transmitting the P-polarized component of the second light beam, and a quarter wavelength plate. When a high density medium is set against the optical hend, recording is performed by the second light beam and reproduction is performed by the first light beam. When a low density medium is set against the optical head, recording and reproduction are carried out by the second light beam.

Abstract: An IC memory card type radio modem includes a connecting portion, a radio section, a radio interface unit section, a channel selection circuit section, a terminal interface unit section, and a control section. The connecting portion can be connected to a PC card portion of a portable information processing device. The radio section is adaptable to at least one type of radio infrastructure. The radio interface unit section is adapted to the radio section. The channel selection circuit section is connected to the radio interface unit section. The terminal interface unit section is connected to the channel selection circuit section. The control section controls the plurality of radio sections. The radio interface unit section is controlled to always switch to a radio infrastructure which can perform communication.

Abstract: An optical head device adapted to be optically coupled to an optical disk includes a light-source laser and an objective lens optically coupled thereto. This lens receives an output light of the light source, and causes it to be projected onto the optical disk to form a focused spot thereon. Photodetectors which are arranged near the light-source laser are optically coupled to the lens in one optical path so that they are responsive to a light component which is reflected from the optical disk toward the photodetectors by way of the objective lens. A beam-shaping prism is located between the lens and a group of the light source and the photodetectors in the optical path. When the laser output light travels toward the lens, the prism reshapes the light into a predetermined isotropic beam profile.