赤 外 線(せきがいせん)

せきがいせん

noun

infrared; infrared rays

1. infrared; infrared rays

Electromagnetic radiation with wavelengths longer than visible light. Used in remote controls, heaters, sensors, and medical equipment.

リモコンは赤外線(せきがいせん)で信号(しんごう)を送(おく)る。

The remote control sends signals using infrared.

赤外線(せきがいせん)センサーが人(ひと)の動(うご)きを感知(かんち)する。

The infrared sensor detects people's movement.

赤外線(せきがいせん)ヒーターは体(からだ)の芯(しん)から温(あたた)まるので冬(ふゆ)に人気(にんき)がある。

Infrared heaters warm you from the core, so they are popular in winter.

USAGE:
赤外線(せきがいせん) literally means "beyond-red rays" — light beyond the red end of the visible spectrum. The word appears in everyday contexts (heaters, remote controls, sensors) as well as scientific ones.

COMMON COLLOCATIONS:

赤外線(せきがいせん)センサー (infrared sensor)
赤外線(せきがいせん)ヒーター (infrared heater)
赤外線(せきがいせん)カメラ (infrared camera)
赤外線(せきがいせん)通信(つうしん) (infrared communication)
近赤外線(きんせきがいせん) (near-infrared)

RELATED WORDS:

紫外線(しがいせん): ultraviolet (beyond violet)
放射線(ほうしゃせん): radiation
可視光線(かしこうせん): visible light

general

Added 2026.3.4 20:12

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