How and when should I clean the lens?

• Clean the projector's lens periodically, or whenever you notice dust or smudges on the surface. To remove dust or smudges, gently wipe the lens with lens-cleaning paper. To remove stubborn smudges, moisten a soft, lint-free cloth with lens cleaner and gently wipe the lens.
  
  Warning:
  • Before cleaning any part of the projector, turn it off and unplug the power cord. Never open any cover on the projector, except the lamp cover. Dangerous electrical voltages in the projector can injure you severely.
  • Do not use a lens cleaner that contains flammable gas. The high heat generated by the projector lamp may cause a fire.
  Caution:
  Do not use glass cleaner to clean the lens, or you may damage it. Avoid touching the lens with your bare hands to prevent fingerprints on or damage to the lens surface.