PURPOSE: To transmit light, to reduce the cost, and to provide sufficient reliability by forming the carbon pattern of a contact part in a contact sheet into a lattice-shape.
CONSTITUTION: When a translucent milky rubber key 4 is pressed, a dome key 6 of a membrane key sheet 5 is pressed and carbon patterns 8, 10 of a contact part 12 in a contact sheet 7 come into contact with one another, and key input is confirmed while an LED 3 is lighted. The light of the LED 3 passes the membrane key sheet 5 through the lattice-shape contact part 12, and is diffused in the rubber key 4, which is thus colored. Since there is no need of making the pattern of the contact part transparent, the cost can be reduced, while sufficient contact reliability can be achieved.
INOUE TSUTOMU
FUKUHARA MASAMI
MORI MASARU
