Nissan Motor Company Limited

Mitsubishi Denki Kabushiki Kaisha

Jidosha Kiki Co., Ltd.

Kanto Seiki Co., Ltd.

Norio Fujiki

Hiroshi Endo

Takashi Kimura

Hiroshi Ikeda

Jun Kubo

Yoichiro Tanaka

Masaki Hirota

Hiroshige Fukuhara

Masahiro Ishikawa

Takatoshi Hayashi

Noriyuki Abe

Hitoshi Kubota

Norimasa Kishi

Masakazu Kobayashi

Teruyoshi Mihara

Yasuki Ishikawa

Michio Kobayashi

Kiyoshi Yamaki

Morihiko Shimamura

Akira Matsumura

Masaaki Katsumata

Yoshio Tobisawa

Kousaku Baba

Akitoshi Mimura

Akira Tachibana

Yukio Hiramoto

Kazuyoshi Fukawa

Yoshiki Masuno

Takashi Nishimoto

Masao Kawagishi

An apparatus for storing digital data includes a clock pulse source and plural serial shift register stages storing data bits. Digital data signals, each having plural databits, are coupled to and shifted in the stages in synchronization with the clock pulses. Data stored in the memory stages stages are held in a non-erasable memory unit provided for each stage while an emergency causing a failure of a power supply of the shift register occurs.

Shift register apparatus for storing data therein

An output buffer circuit, in which a pair of current sources is connected to positive and negative power sources, and a first inverter having input and output terminals, is arranged between the current sources, in which a second inverter having input and output terminals, is connected to the output terminal of the first inverter, the second inverter including at least one of P-channel and N-channel MOSFETs, and a capacitor is connected between the input and output terminals of the second inverter.

Output buffer circuits for reducing noise

A MOSFET device including a power MOSFET and a current mirror MOSFET, in which the drains of the two MOSFETs are coupled in common to each other, and the gate electrodes of the two MOSFETs are linked in common to each other, and in which a diode device for protecting a gate oxide film for the current mirror MOSFET is connected between the sources of the two MOSFETs.

MOSFET including current mirror FET therein

An input protection circuit for an electronic circuit includes a switching circuit operable between an ON state and an OFF state for generating an input for the electronic circuit, a first circuit responsive to an excess level of input for forming a clamping circuit across a first resistor for shunting an excess level input, a second circuit monitoring an input from the switching means for detecting a state of the switching circuit for producing an ON/OFF signal depending upon the detected state of the switching circuit, the second circuit including a second resistor which forms a series circuit with the first resistor and the switching circuits while the switching circuits is in an ON state. The switching circuits is operated to an ON position for establishing the series circuit for setting the level of the input at a minimum level and to an OFF position for opening the series circuit for setting the level of the input at a maximum level. The second circuit is set at a threshold level to be compared with the input level for detecting the state of the switching circuit, the threshold level being set at a level higher than the minimum level and lower than the maximum level so as to assure detection of the state of the switching circuits.

Circuit for protecting input of semiconductor device

An apparatus for measuring the frequency of a pulse train signal and method therefor applicable to a speedometer of a vehicle are disclosed in which a count value C of at least one counter which counts number of pulses in the pulse train signal for predetermined counting intervals of time .DELTA.T (=T/n, wherein T denotes a frequency measuring time interval and n denotes a calculation constant) is updated to a value related to the count value for each predetermined counting interval of time .DELTA.T and stored and outputted for each predetermined counting interval of time .DELTA.T so that the same or better performance as that using a stagger ring method can be achieved. The value is expressed by (C-C/.alpha.) in a first preferred embodiment (wherein .alpha. denotes the calculation constant preferably equal to n), by (C-C.times.m/.alpha.+D) in a second preferred embodiment (wherein m denotes the number of counters and D denotes the latest count values of the m counters during .DELTA.T at the time of update), by (C-M.sub.1 .times.C/.alpha.+M.sub.2 D) in a third preferred embodiment (wherein M.sub.1 and M.sub.2 denotes values determined according to a change rate of the count value C of the counter with respect to time and D denotes the latest count value of the counter for .DELTA.T at the time of update), and by (C-C/M) in a fourth preferred embodiment (wherein M denotes a value determined according to a change rate of the count value C of the counter with respect to time).

Apparatus and method for measuring the frequency of a pulse signal

To prevent the driver from being confused by the fact that a pseudo vehicle speed to diagnose a vehicle speed meter is indicated when a vehicle speed sensor is disconnected by an accident during vehicle travelling, a pseudo vehicle speed sensor signal is applied to the vehicle speed meter only when the vehicle speed sensor is disconnected from the vehicle speed meter and the disconnected sensor is reconnected to the meter a predetermined time period after the sensor has been disconnected from the meter. The self-diagnostic apparatus is composed of counters, flip-flops and logical gates, and is reset whenever an ignition switch is turned on.

Self-diagnostic apparatus for vehicle meter

An apparatus for testing a cross-coil instrument having a pointer, a sensor for sensing a condition to produce a sensor signal indicative of the sensed condition, and a converter coupled to the sensor for converting the sensor signal to a deflection of the pointer. The apparatus comprises a fault detector coupled to the sensor for detecting a disconnection fault to produce a command signal, and a test signal generator responsive to the command signal for generating a predetermined test signal to the converter, thereby moving the pointer to a predetermined position. The operation accuracy of the cross-coil instrument may be checked from the difference between the actual and predetermined pointer positions when a connector provided in a signal line between the sensor and the fault detector is pulled out.

Cross-oil instrument having testing apparatus for vehicular sensor

A relay valve is operatively disposed between a pressurized air source and a work chamber of a brake booster. The relay valve has a pilot chamber so that the relay valve can feed the work chamber with a pressurized air, the pressure of which corresponding to that of a pressure applied to the pilot chamber. Electromagnetic valves are arranged to selectively connect the pilot chamber with the pressurized air source and the atmosphere. The valves are so controlled by an electronic control unit that the pilot chamber is supplied with pressurized air the pressure of which being determined in accordance with a brake pedal force applied from a brake pedal to an input means of the booster.

Pneumatic power brake system

An input pressure detecting device is arranged in an input side of a pneumatic brake booster, which comprises an elastic member having a given portion which expands when a pressure is applied to the elastic member, a pressure sensor for issuing, upon receiving a pressure, a signal representative of the intensity of the pressure applied thereto, and an axially movable piston intimately disposed between the given portion of the elastic member and the pressure sensor. Upon application of force to the elastic member due to depression of the brake pedal, the elastic member is compressed causing the given portion to expand and thus applying a corresponding but small pressure to the pressure sensor through the piston.

Pneumatic brake booster

A moving obstacle detection system for an automotive vehicle utilizing a doppler effect of the transmitted wave against an obstacle which runs in front of the vehicle such as another vehicle. The system generally comprises: (a) a doppler radar unit which operates so as to produce a doppler signal when the vehicle is halted; (b) a detecting means which detects the changing phase of a doppler signal produced from the doppler signal; (c) a discriminating means which discriminates the departure of another vehicle from the front area of the vehicle and the intersection of another vehicle or pedestrian traverse to the vehicle on a basis of the frequency changing rate or amplitude level changing rate of the detected doppler signal; and (d) an alarm unit which produces an alarm in a predetermined form only when the departure of another vehicle from the front detection area of the doppler radar unit or in the case when another vehicle straightly approaches or departed from the vehicle and in the case when another vehicle or pedestrian goes across the vehicle, separately from each other.

Moving obstacle detection system for a vehicle

An automotive radio receiver with a radio frequency interference elimination includes a noise detector adapted to detect noise in the power source wiring and a circuit for eliminating radio frequency interference noise. The detector is physically connected to the power source wiring so that it can satisfactorily detect noise in the power source wiring such as spark ignition noise and switching noise of the automotive electric equipments. The noise elimination circuit includes a switch normally closed and responsive to the noise signal produced by the noise detector to open, and a capacitor for holding the radio signal level while the switch is opened and discharging the constant-level signal for reproduction of the radio sound.

Automotive radio receiver with radio frequency interference elimination

A noise eliminating system is disclosed for use in a radio receiver including a detector. The system comprises a differentiation circuit for differentiating the signal fed thereto from the detector, a clipper circuit for limiting the amplitude of the signal applied thereto from the differentiation circuit below a clipping level, a clipping level control circuit responsive to the strength of the electric field received in the receiver for varying the clipping level at a rate multiple of the electric field strength, means responsive to the electric field strength for selectively setting the rate at one of a plurality of values, and an integrating circuit for integrating signal fed thereto from the clipper circuit.

Noise eliminating system

A radar-operated vehicle safety assurance system includes a radar device which detects the vehicle relative speed or range to an object. A safety limit value of the detected operating parameter is computed by means of a safety range detection or safety speed detection circuit as a function of a detected operating parameter. A visual indicator is provided which visually indicates the difference between the detected value and the computed safety limit value to allow the vehicle driver to become continuously aware of the marginal conditions of the vehicle in relation to the safety limit.

Radar-operated vehicle safety assurance system

A testing circuit for a radar-operated vehicle safety assurance system includes a test signal generator for generating an artificial intermediate frequency return signal. The radar system is switched on a manual command signal from the normal operating mode to an under-test mode to accept the artificial signal to determine the speed of the vehicle relative to a hypothetical target and the instantaneous value of the distance to the hypothetical target. The radar system includes a vehicle roadway speed sensor which normally supplies the system with the instantaneous speed value of the vehicle. When the system is switched to the under-test mode, a signal indicative of a predetermined vehicle road speed is applied to the radar to determine the safety distance to the hypothetical target. When the instantaneous value of the distance to the hypothetical target corresponds to the safety distance, an alarm signal is delivered from the radar system. This signal is checked to see if it occurs within a preselected time interval so as to ensure that the radar system functions properly.

Testing circuit for radar-operated vehicle safety assurance systems

A counter is provided for detecting the frequency of generation of collision imminence signals produced in a conventional type of anti-collision radar system for a vehicle. An odometer and/or a clock pulse generator is connected to the counter for applying a reference counting period so that the counter is utilized for generating a signal with which an alerting device which is independent from that of the radar system, is energized when the frequency reaches a predetermined value during the reference counting period.

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Yokohama, Japan

Norio Fujiki