Abstract: In a handover control apparatus, a terminal is wirelessly connected with one of base stations to establish a wireless data communications connection. The terminal executes a handover process using a handover process section when an electric wave state becomes lower than a threshold value, which is variable. The threshold value can be adjusted according to a moving speed of the terminal. Furthermore, the threshold value is corrected according to the past electric wave state. The threshold value is corrected according to a difference of (i) a minimum electric wave state in a preceding handover process, and (ii) a lower limit. The correction is executed so as to reduce an excessive decline of an electric wave state in a succeeding handover process. Deterioration of a communications quality during a handover process can be thereby suppressed.

Abstract: A handover control apparatus selects, as a target station, an adjacent station having an upturn and stable transition trend of reception level of a radio wave received by a radio, when necessity to carry out handover is determined, and performs handover for switching from a serving station to the target station when the transition trend of the reception level of the received radio wave from the serving station is in a downturn trend and a calculation value of a serving station approximation equation is smaller than a calculation value of an adjacent station approximation equation at a determination timing.

Abstract: A handover control apparatus selects, as a target station, an adjacent station having an upturn and stable transition trend of reception level of a radio wave received by a radio, when necessity to carry out handover is determined, and performs handover for switching from a serving station to the target station when the transition trend of the reception level of the received radio wave from the serving station is in a downturn trend and a calculation value of a serving station approximation equation is smaller than a calculation value of an adjacent station approximation equation at a determination timing.

Abstract: In a handover control apparatus, a terminal is wirelessly connected with one of base stations to establish a wireless data communications connection. The terminal executes a handover process using a handover process section when an electric wave state becomes lower than a threshold value, which is variable. The threshold value can be adjusted according to a moving speed of the terminal. Furthermore, the threshold value is corrected according to the past electric wave state. The threshold value is corrected according to a difference of (i) a minimum electric wave state in a preceding handover process, and (ii) a lower limit. The correction is executed so as to reduce an excessive decline of an electric wave state in a succeeding handover process. Deterioration of a communications quality during a handover process can be thereby suppressed.

Abstract: It is determined whether each of several subcarriers has an adequate propagation characteristic in a first horizontally polarized wave antenna. Of the several subcarriers, a subcarrier, which is determined to have an adequate propagation characteristic in the first horizontally polarized wave antenna, is assigned with transmission data. A transmission signal containing the transmission data is thereby transmitted from the first horizontally polarized wave antenna. In addition, of the several subcarriers, a subcarrier, which is determined not to have an adequate propagation characteristic in the first horizontally polarized wave antenna, is also assigned with transmission data in either a second horizontally polarized wave antenna or a vertically polarized, wave antenna. A transmission signal containing the transmission data is thus transmitted from the second horizontally polarized wave antenna or the vertically polarized wave antenna.

Abstract: With a capacitor C inserted in an interstage portion of multiple stages of amplifier circuits, a high pass filter is generated by the capacitor C and an input impedance |Z| of an amplifier circuit in the next stage. Accordingly, frequency components lower than a cutoff frequency fc are cut off, and therefore are not transferred to the subsequent stage. However, radio frequency components higher than or equal to a fundamental wave component determined by an envelope of a radio frequency signal intermittently transmitted can be transferred. Consequently, transfer of DC offset potentials can be cut off, and noise, such as flicker noise, having great power in a DC or near-DC zone can be effectively cut off. Thereby, the S/N ratio, detection sensitivity, and detection accuracy can be improved.

Abstract: A start signal output circuit having an RF/DC conversion circuit to which radio frequency power (RF) of specified frequency is inputted and from which a direct current potential (DC) is outputted, comprises a detection/amplification circuit 210 which includes a voltage doubler wave-detector circuit 10 configured including a sensing diode Q1 (Tr34) for sensing the RF power, a differential amplifier including differential pair transistors Tr31 and Tr32, and a current mirror circuit. A base current of one Tr31 of the differential pair transistors is brought into substantial agreement with a DC component of a current flowing through the sensing diode Q1 (Tr34). A total of currents flowing through the differential pair transistors Tr31 and Tr32 is regulated to a substantially constant value by the current mirror circuit. Thus, the start signal output circuit which is small in size, high in sensitivity and low in power consumption can be realized.

Abstract: With a capacitor C inserted in an interstage portion of multiple stages of amplifier circuits, a high pass filter is generated by the capacitor C and an input impedance |Z| of an amplifier circuit in the next stage. Accordingly, frequency components lower than a cutoff frequency fc are cut off, and therefore are not transferred to the subsequent stage. However, radio frequency components higher than or equal to a fundamental wave component determined by an envelope of a radio frequency signal intermittently transmitted can be transferred. Consequently, transfer of DC offset potentials can be cut off, and noise, such as flicker noise, having great power in a DC or near-DC zone can be effectively cut off. Thereby, the S/N ratio, detection sensitivity, and detection accuracy can be improved.

Abstract: A start signal output circuit having an RF/DC conversion circuit to which radio frequency power (RF) of specified frequency is inputted and from which a direct current potential (DC) is outputted, comprises a detection/amplification circuit 210 which includes a voltage doubler wave-detector circuit 10 configured including a sensing diode Q1 (Tr34) for sensing the RF power, a differential amplifier including differential pair transistors Tr31 and Tr32, and a current mirror circuit. A base current of one Tr31 of the differential pair transistors is brought into substantial agreement with a DC component of a current flowing through the sensing diode Q1 (Tr34). A total of currents flowing through the differential pair transistors Tr31 and Tr32 is regulated to a substantially constant value by the current mirror circuit. Thus, the start signal output circuit which is small in size, high in sensitivity and low in power consumption can be realized.

Abstract: A communication system for vehicles, which obtains exact communication processing with responders mounted on vehicles running on a road having a plurality of traffic lanes, is disclosed. An expressway has three traffic lanes. A gantry is disposed in a specified position on the expressway. On the gantry are disposed antenna units to counter the traffic lanes respectively. The antenna units are provided with communication areas by means of a pair of antenna elements respectively. The antenna element is composed of a microstrip array antenna disposed with eight pieces of patches laid out in two rows with four pieces in each row. The antenna units controls communication processing to communicate with vehicles adjoining each other. When response signals are sent from a vehicle mounted responder, the vehicle mounted responder is fixed and communication processing for toll collection is performed.

Abstract: The present invention provides an automobile toll system which may determine accurately whether a device mounted on a vehicle has a mismatch even when a small automobile is running just behind a large automobile and therefore blocked from communicating with the toll system. In the system, a vehicle type discriminator determines the type of a vehicle passing therethrough based on its shape and weight and transmits determination data to a lane controller. A controller for a reading antenna continuously transmits vehicle type data retrieved from a response signal from the vehicle-mounted device when vehicles stay in the antenna communication area. The lane controller compares type discrimination data and vehicle type data for each vehicle in the order of vehicles leaving the communication area to recognize a mismatch if the data are different.

Abstract: An electronic device intended for use as a tag to be attached to identify contents of the container to which it is attached. In particular, the present invention relates to an electronic tag which has a facility for storing delivery information and is equipped with a responding means for transmitting the delivery information stored therein in response to a query signal received from an interrogating apparatus. Codes, including items such as the names and addresses of the destination and the sender, and a sorting code are written into predetermined blanks of a delivery label, and into a memory. The memory responds to a query by transmitting the sorting information to allow automated sorting. The tag may be initiated only when torn, to extend battery shelf life.

Abstract: The primary object of the invention is to realize a mobile object identification system of simple construction and low cost, in which the responding unit attached to a mobile object writes data only once when it receives write signals repeatedly in communication with antenna units. When a tag unit (responding unit) receives a write signal from a writing antenna unit, it writes data to the data memory when a completion flag is cleared. When the data is first written, a control circuit sets the completion flag. Then, if the tag unit receives additional write signals in the communication area of the same writing antenna unit, the control circuit invalidates the data write command on the ground that the completion flag is set, thereby preventing duplicate data writing.

Abstract: An electronic device intended for use as a tag to be attached to identify contents of the container to which it is attached. In particular, the present invention relates to an electronic tag which has a facility for storing delivery information and is equipped with a responding means for transmitting the delivery information stored therein in response to a query signal received from an interrogating apparatus. Codes, including items such as the names and addresses of the destination and the sender, and a sorting code are written into predetermined blanks of a delivery label, and into a memory. The memory responds to a query by transmitting the sorting information to allow automated sorting. The tag may be initiated only when torn, to extend battery shelf life.

Abstract: A movable-object identification system includes an interrogator for transmitting an interrogation signal, and a responder mounted on a movable object for transmitting a reply signal in response to the interrogation signal. The reply signal contains identification information. The responder includes an antenna for receiving the interrogation signal from the interrogator and for radiating the reply signal; and an input device connected to the antenna for receiving an electric power of the interrogation signal received by the antenna. The input device includes a receiving element for dividing the received electric power into a first separation electric power and a second separation electric power corresponding to a traveling and reflected wave of the interrogation signal, respectively. The receiving element has an impedance.

Abstract: A device for detecting a transmissivity of a substance utilizing a transmitted light value, which comprises a light emitting element and a photo detecting element. The light emitting element and the photo detecting element are spaced from each other at a predetermined distance so that a transmitted light value of a substance passing through the space is detected as an amount of light transmitted therethrough. The photo detecting element further comprises a photo oscillator circuit including the photo detecting element as one component thereof and outputs a signal having characteristics selected from a cycle and a frequency corresponding to the transmitted light value, and when the condition of a substance exceeds a predetermined reference level, such information is displayed at a display unit.

Abstract: A speed control system for a motor vehicle automatically controls a throttle valve so as to allow the vehicle to run at a desired velocity at all times. The system includes a laser radar for detecting a preceding vehicle and measuring the distance therefrom, and a control computer in which a proper distance responsive to a vehicle velocity is set. The control computer discriminates proximity to the preceding vehicle through change in the distance at a certain interval. When the distance exceeds the proper distance, the control computer reduces the desired velocity in case proximity to the preceding vehicle is discriminated at a plurality of times continuously and increases the desired velocity in case no such proximity is discriminated, and when the distance is below the proper distance, the computer decelerates the vehicle by directly controlling the throttle valve in the closing direction, allowing tracing running with the proper distance from the preceding vehicle.

Abstract: A vehicle speedometer is disclosed which accurately measures vehicle velocity despite significant vehicle vibration, which causes variation of the angle of incidence of the measuring wave. Two transceivers are mounted on the vehicle, along with means to determine a frequency difference and an angle variation, both being used in an accurate velocity determination.

Abstract: A device for unlocking a lid provided in a vehicle includes an unlocking actuator unit, a magnetic sensor unit, a signal processing unit, and a controller means. A transmitter unit with a power source generates and transmits a specific magnetic unlocking signal which is received by the magnetic sensor unit, hence, the unlocking actuator is controlled through the signal processing means and the controller means and, hence, the lid is unlocked.

Abstract: In a zigzag running warning system for automotive vehicles which detects and gives a warning of zigzag running of a vehicle, a terrestrial magnetism sensor generates an electric signal having an amplitude varying in dependence on the direction of travel of the vehicle with respect to the direction of the terrestrial magnetism. An electronic unit in the system discriminates that vehicle is running in a zigzag direction when the amplitude of the electric signals changes in excess of a predetermined value at a period which is less than a predetermined time, and informs the driver of the zigzag running by a speaker, lamp or the like.