In 1967 Vactec introduced a compact RO branded as Vactrol. Unlike the tube-coupled ROs of Fender and Gibson, Vactrols were sealed and sturdy devices. In the early 1970s, Vactec replaced incandescent bulbs with LEDs. This increased the switching speed, but not to the level required for digital devices. Therefore, the introduction of the faster photodiodes and phototransistors in the 1970s pushed out ROs from the market. ROs retained narrow application niches in sound equipment and some industrial automation devices that did not require high speeds. Vactec did not extend their rights to the trademark Vactrol, and it has become a household word in the English language for any RO used in audio equipment, including the ROs of Fender and Gibson. As of 2010, the Vactrol ROs were produced by PerkinElmer, the successor of Vactec until its illumination and detection solutions businesses were divested as an independent company Excelitas Technologies in November 2010.Excelitas Technologies, Excelitas ended the production of ROs in December 2015.Excelitas Technologies, Product EOL announcement, 1 June 2015,
