Fujikura Limited

Yasushi Nakamura

Nobumasa Misaki

Yoshiharu Unami

Fumio Yajima

Shinichi Niimi

Akira Kamijima

Naoshi Yamada

Shinichi Nikaido

Katsuyuki Arai

Shoji Yoshino

A proximity sensor includes a sense electrode having a first capacitance to ground, wherein the first capacitance varies in response to proximity of an object to be sensed; a first sense circuit which provides a first pulse signal having a pulse width determined in accordance with the first capacitance; a reference capacitor; a second sense circuit which provides a second pulse signal having a pulse width determined in accordance with a second capacitance of the reference capacitor; and a computing circuit which computes a difference pulse by subtracting the second pulse signal from the first pulse signal and provide a pulse of the difference pulse width.

Proximity sensor and proximity sensing method

A hybrid sensor is formed by stacking a plurality of flexible sheets each provided with electrode patterns. The hybrid sensor includes a contact pressure sensor which has switches turning on or off by a pressure load, and an electrostatic capacitance sensor which detects a nearby object without contacting the object. The electrode patterns include a switching electrode pattern as the switch of the contact pressure sensor and a detecting electrode pattern as the detecting electrode of the electrostatic capacitance sensor. The detecting electrode is formed to cover substantially the entire area other than the area on which the switching electrode pattern is formed.

Hybrid sensor including electrostatic capacitance sensor

There is provided media converter having an integrated local information transmission function and a fault alarm signal communication system for transmitting local information using a frequency outside the communication frequency bands for data signals. In the subscriber's media converter, based on input local information, a control section sets a transmission frequency outside the communication frequency bands and outputs a signal instructing that a transmission be made. A media independent interface section receives this signal and transmits the signal in the instructed frequency. In the station media converter, a media independent interface section detects the frequency in which the local information is transmitted from the received signal. A control section then generates local information using the detected frequency and outputs it to an SNMP unit.

Media converter with integrated local information transmission function and fault alarm signal transmission system

An electrical capacitance proximity sensor with high detector sensitivity has an insulating substrate, a detector electrode and an earth electrode formed in a fixed pattern on one face of the insulating substrate, and a detector circuit which detects an object approaching the detector electrode and the earth electrode by detecting the capacitance between the detector electrode and the earth electrode. The detector electrode is formed in a shape such that it surrounds the earth electrode.

Electrical capacitance proximity sensor

An electrical capacitance proximity sensor for detecting a nearby object takes a normal operation mode for detecting the nearby object approaching and a self-diagnostic mode for detecting a correct connection between a sensor section and a detecting circuit section. The detecting circuit section is provided with a buffer controller which supplies a second oscillation signal having the same phase and voltage as a first oscillation signal applied to a guard electrode in the normal operation mode, and stops supplying the second oscillation signal in the self-diagnostic mode. A control circuit determines whether the sensor section is correctly connected to the detecting circuit section base on the change in the detecting signal in the normal operation mode and the self-diagnostic mode.

Apparatus for and method of using optical interference of light propagating through an optical fiber loop

A signal/vibration detecting technique employs a simple structure to identify a target optical fiber among many and carry out a bidirectional conversation through the target optical fiber. First ends of optical fibers ( A, B), one of which is a target optical fiber, are connected to an optical transceiver ( ). Second ends of the optical fibers are connected to each other to form a loop. A local unit ( ) is installed at the loop. The local unit vibrates the loop, and the optical transceiver emits lights so that the lights are oppositely propagated through the loop. The propagated lights are coupled together so that they interfere with each other. In the intensity of the interfering lights, a change corresponding to the vibration is detected to identify the target optical fiber. Once the target optical fiber is identified, it is used to carry out a conversation between the optical transceiver and the local unit.

Growing community of inventors

Sakura, Japan

Yasushi Nakamura