A backlight device for LCD displays can include a light-emitting source of the type that includes a cold-cathode or hot-cathode fluorescent tube that is lit with a high-frequency power supply. Input that specifies a path is received. The locking element includes a jaw formed with at least one ratchet and being pivotally installed on the tube. The polishing pads can be pre-attached to both a supply roll and a take-up roll to form a cartridge which can be easily removed from the apparatus and replaced with another cartridge. Furthermore, the present invention relates to processes for preparing compounds of formula, to intermediates used in the preparation of compounds of formula, to herbicidal compositions comprising compounds of formula and to certain novel pyridopyridines, pyridodiazines and pyridotriazines.