Ricoh Company, Ltd.

Artek Kabushiki Kaisha

Kiyoshi Sone

Ichiro Yoshihara

Takeshi Abe

Keishin Tsuchiya

Kazuhito Saito

Isamu Orima

Hitoshi Sone

Kiyoshi Abe

A variable ISI transmission channel apparatus inserted in a high-speed transmission channel for the high-speed serial data communication simulates a 'live' ISI environment to which the high-speed transmission channel in operation is exposed, in a situation such as a bit error test by means of continuously adjusting an amount of inter-symbol interference (ISI) in the high-speed transmission channel. By allowing an undersurface of a transmission loss generating member () () () such as a dielectric, a magnetic body, and an electric conductor to face, and slide on, a top surface of a conductor strip () exposed on a top surface of a plate-shaped dielectric substrate (), a facing area is continuously increased/decreased. A dielectric loss, a magnetic loss, or a resistance loss increased/decreased in the transmission loss generating member is reflected on a high-frequency signal on the conductor strip ().

Variable ISI transmission channel apparatus

An alarm system for detecting a dangerous condition such as the increase in content of or the presence of toxic or inflammable gas in the air and giving a warning signal. The alarm system comprises an AC power supply, a full-wave rectifier connected to the AC power supply and rectifying alternating current from the AC power source into direct current. An AC bridge circuit connected to the AC power supply and includes a sensor element at least in one branch. An AC operational amplifier is supplied with power from the full-wave rectifier and receives an input signal which is the output signal delivered from the bridge circuit through a DC blocking capacitor. A thyristor is connected in parallel with the AC power supply, with its control gate connected to the output of the operational amplifier, and its main electrodes in series with an alarm indicator actuable when the thyristor is triggered into the conduction state. Such triggering occurs when the output signal voltage from the operational amplifier reverses its phase by 180.degree., i.e., when the resistance of the sensor element varies when a dangerous condition exists.

Alarm system having phase-sensitive bridge circuit

Two reed switches are alternately closed by a magnet rotating with a shaft of a water meter or the like which is to be read remotely. A capacitor discharges through the reed switches when the same are closed, increasing the switch current without increasing the external power source current, thereby producing temporary partial fusion of the switch contacts and maximum contact effectiveness. A low-pass filter and a snap action circuit such as a Schmitt trigger are connected to the switches to eliminate the effects of contact bouncing and noise signals from the output of the circuit.

Mechanical switch circuit comprising contact conditioning means

Video signals are transferred from a phonograph record or low speed magnetic tape and stored on a magnetic sheet disc rotating at low speed. The magnetic sheet disc is then rotated at high speed to output the video signals to a television display or the like. In the invention, clock signals representing equal intervals of time are provided with the video signals on the phonograph record or low speed magnetic tape. The signals are picked up when the record or tape is rotated and the frequency thereof is analogous to the instantaneous rotational speed of the record or tape drive motor. The video is stored on the magnetic sheet disc by a write head. The magnetic sheet disc is provided withreference marks which are sensed when the magnetic sheet disc is rotated and the frequency thereof is analogous to the instantaneous rotational speed of the disc relative to the write head. The two frequencies are compared. The speed of the disc relative to the write head is controlled by varying the speed of the disc and/or rotating the write head relative to the disc so that the ratio of the instantaneous speed of the record or low speed tape to the design speed thereof is equal to the ratio of the instantaneous speed of the disc relative to the write head to the design speed of the disc. The video signals are thereby stored on the disc in the correct positions to eliminate jitter on the television display.

Growing community of inventors

Tokyo, Japan

Kiyoshi Sone