| 摘要 |
PROBLEM TO BE SOLVED: To realize a portable communication terminal equipment or the like that is capable of full duplex communication and that is not affected by an external light. SOLUTION: A portable telephone set 2 is provided with an optical communication interface 4 on its side. The optical communication interface 4 includes a light transmission section 8, consisting of light emitting diodes 6, a light- receiving section 12 consisting of photo diodes 10 which are placed in parallel close to each other, and an optical filter 14 that is placed closely in front of the light transmission section 8, and the light receiving section 12. A projection 14A is formed on an outer face of the filter 14 in front of the light transmission section 8, and a recessed part 14B is formed in front of the light-receiving section 12. When optical communication is made between the portable telephone sets 2, the filters 14 are pressed in contact with each other so that the projection 14A, and the recessed part 14B of the filter 14 of the portable telephone set 2 are closely fitted to the recessed part 14B and the projection 14A of the filter 14 of the other portable telephone set 2 respectively. |
