Sumitomo Metal Mining Company, Ltd.

Azbil Corporation

Yamatake Corporation

Hiroshi Hatanaka

Nobuo Nakamura

Hiroshi Sasaki

Takashi Nakao

Minoru Tanaka

Shuuji Oosumi

Shinichi Kawai

Shinichiro Suzuki

Tetsuya Kajita

Tomio Kajigaya

Yasutaka Nomi

Takumi Hayashi

Takayuki Hosoi

Taichirou Kato

A photoelectric sensor includes the following components. A disturbance detection unit detects a disturbance by comparing a light reception result obtained by a light receiver with a first threshold and with a second threshold for a predetermined period in a state where no light is transmitted by a light transmitter. The second threshold takes a value of a sign opposite to that of the first threshold relative to a no-signal state. A waiting unit waits for the light reception result obtained by the light receiver to become within a range from the first threshold to the second threshold upon detection of a disturbance. A disturbance type determination unit causes detection of a disturbance to be performed again after the waiting. A light transmission instruction unit instructs the light transmitter to transmit light when no disturbance is detected for a predetermined period.

Photoelectric sensor with disturbance detection

A photoelectric sensor includes a current division control circuit that sequentially sets a reference voltage for each current divider circuit along one of the arrangement directions of photodiodes so that the reference voltage for the current divider circuit is equal to or larger than the voltage value of the reference voltage set for a current divider circuit in the preceding stage, and sets one common control voltage for all of the current divider circuits, the common control voltage falling within a range that includes all of the reference voltages.

Photoelectric sensor

A bismuth-substituted rare-earth iron garnet crystal film (RIG) which has an insertion loss of less than 0.60 dB and which can be produced in a high yield, as well as an optical isolator, which is grown by liquid phase epitaxy on a non-magnetic garnet substrate represented by a chemical formula of Gd(ScGa)O, wherein the bismuth-substituted rare-earth iron garnet crystal film is represented by a chemical formula of LaGdBiFeO(provided that 0&#x3c;x&#x3c;3 and 0&#x3c;y&#x3c;3), and a composition ratio between the La, Gd, and Bi falls within a numeric value range corresponding to the inside of a quadrilateral having composition points A, B, C, and D as vertices in a La&#x2014;Gd&#x2014;Bi ternary composition diagram: composition point A (La: 0.15, Gd: 1.66, Bi: 1.19), composition point B (La: 0.32, Gd: 1.88, Bi: 0.80), composition point C (La: 0.52, Gd: 1.68, Bi: 0.80), and composition point D (La: 0.35, Gd: 1.46, Bi: 1.19).

Bismuth-substituted rare-earth iron garnet crystal film and optical isolator

A bismuth-substituted rare-earth iron garnet crystal film (RIG) which has an insertion loss of less than 0.6 dB and which can be produced in a high yield, as well as an optical isolator, which is grown by liquid phase epitaxy on a non-magnetic garnet substrate represented by a chemical formula of Gd(ScGa)O, wherein the RIG is represented by a chemical formula of NdGdBiFeO, and x and y satisfy 0.89&#x2266;x&#x2266;1.43 and 0.85&#x2266;y&#x2266;1.19. In contrast to conventional RIGs, the RIG represented by the chemical formula of NdGdBiFeOof the present invention has an insertion loss of less than 0.6 dB and makes it possible to reduce the amount of heat generated because of absorption of light at wavelengths of about 1 &#x3bc;m. Hence, the RIG has such a remarkable effect that the RIG can be used as a Faraday rotator used for an optical isolator in a high-power laser device for processing.

A high-frequency oscillation proximity sensor with an improved detection sensitivity uses, as a detection coil, a two-thread coil formed of substantively two coil conductors joined together at their first ends to form a joint connection end and twisted together, one of the two coil conductors being used as a resonance circuit coil Land the other as a copper resistance compensation coil L, and comprises a drive circuitfor supplying a drive current to the joint connection end of the two-thread coil to thereby drive the detection coil to oscillate, a bufferfor taking out an oscillating output voltage generated at the joint connection end of the two-thread coil, and a phase shift circuitfor turning the phase of the oscillating output voltage taken out by the buffer by a predetermined angle and feeding it back to the copper resistance compensation coil to thereby negate the copper resistance of the two-thread coil. The drive circuit comprises a nonlinear amplifierfor changing the amplitude of the oscillating voltage generated at the two-thread coil in multiple stages to thereby impart a soft oscillation characteristic to a high-frequency oscillation circuit comprising the nonlinear amplifier and the two-thread coil.

High-frequency oscillation type proximity sensor

Growing community of inventors

Tokyo, Japan

Hiroshi Hatanaka