Patent ID: 7757263

Claim:
A front-end device of a set-top box for two-way communication, the front-end device comprising: a cable interface module which comprises: a first connector part for connection to a cable television network; a second connector part connected to a communication signal modulating part; a third connector part; and a diplexer, which is connected to the first connector part, the second connector part and the third connector part, and is operable to: (a) receive a first signal that is input from the first connector part, (b) output the received first signal to the third connector part, and (c) output, to the first connector part, the second signal that is received by the diplexer from the communication signal modulating part through the second connector part and has a second frequency lower than a first frequency of the first signal; a video tuner module which comprises: a fourth connector part, which has a shape that can connect to the cable television network when the cable interface module is removed from the front-end device, and is connected to the third connector part when the cable interface module is included in the front-end device; a fifth connector part; a video tuner, which selects a channel from an input signal; and a first distributor, which is connected to the fourth connector part, the fifth connector part and the video tuner, and branches the first signal that is input from the fourth connector part to the fifth connector part and to the video tuner; and a communication tuner, which is connected to the fifth connector part and selects another channel from the signal output from the fifth connector part, wherein a connection of the fifth connector part to the communication tuner is exclusive of the cable interface module.