light pen 
noun
1A handheld pen-like photosensitive device held to the display screen of a computer terminal for passing information to the computer.You may have to adjust the brightness of your monitor to get your light pen to work properly....
- Various other light pens have been developed which include a lens for focusing the axially received light.
- The radiated light is directed so as to be projected from a tip of the light pen as required.
2A handheld light-emitting device used for reading barcodes.
- kitchen
- kitchenalia
- kitchen cabinet
- kitchen-diner
- kitchener
- Kitchener bun
- Kitchener helmet
- Kitchener, Herbert
- Kitchener moustache
- Kitchener mustache
- kitchenette
- kitchen foil
- kitchen garden
- kitchen maid
- kitchen midden
- kitchen paper
- kitchen police
- kitchen porter
- kitchen range
- kitchen roll
- kitchen sink
- kitchen sink drama
- kitchen tea
- kitchen towel
- kitchen unit