Patent ID: 7736042
Filing Date: 2010-06-15
Classification: G01D,G02B,G06F,H01H,Y10S

Abstract:
1. A keypad combination back light unit in a keypad apparatus having a backlighting function, the back light unit comprising: a light guide plate having a light guide pattern part; at least one light emitting unit provided at a sidewall of the light guide plate, and irradiating light to the light guide plate; a character layer provided on an upper surface of the light guide plate; a transparent protective layer provided on an upper surface of the character layer, and having a greater hardness than the light guide plate and a smaller thickness than the light guide plate; and a light leakage prevention pattern provided at an edge of the light guide plate, wherein the light leakage prevention pattern reflects light irradiated from the light emitting unit and not encountering the light guide pattern part, and prevents light leakage outside the light guide plate.