Found some info online so I added them the best I could.

LX prefix will describe retails LaserDisc players but they also had other lines of optical discs (not compatible with LD) using writable media encased in cartridges.

LQ Series (12"/30cm in cartridge)

• Panasonic LQ-3031T (USA, Recorder)
• Panasonic LQ-3032T (USA, Player)
• Panasonic LQ-D5500P (Japan, Recorder)

English User Manual for the LQ-303x is here.

TQ Series (8"/20cm without cartridge)

• National TQ-2600F (Japan, Recorder)
• National TQ-2700F (Japan, Recorder)
• National TQ-3100F (Japan, Recorder ?)

The cartridges were either:

• Single-side Panasonic Optical Disc Cartridge [TQ-FH331]
• Double-side Panasonic Optical Disc Cartridge [TQ-FH332]

They seemed to have been used for medical imagery, industrial projects, etc.

Julien