Q.S.I Co., Ltd is a Korea-based company mainly engaged in the manufacture of semiconductor laser diodes (LDs). The Company produces LDs used for power tools and laser modules, barcode scanners, laser beam printers, optical pickup units such as digital versatile discs (DVDs) and compact discs (CDs) players, and other areas such as medical equipment, sensors, and other optical communications. The Company provides its products under the brand name of QSI Laser Diode. The Company distributes its products within domestic market and to overseas markets. Its clients include Fuji Xerox, Panasonic, Samsung, Stabila and others.