Telephone set and method of controlling off-hook/on-hook state of the telephone set

A telephone set, comprising a handle and a host, wherein the handle is connected to the host through a signal transmission line, the handle comprising a microphone, a telephone receiver, and a first signal transceiver, wherein the telephone receiver is electrically connected to the first signal transceiver, and the microphone is electrically connected to the first signal transceiver, and the host comprises a processor and a second signal transceiver, and the processor is electrically connected to the second signal transceiver, wherein;

• the handle further comprises a first switch, and a connection state of the first switch controls an electrical connection state between the microphone and the first signal transceiver;
• and
• the host further comprises a second switch, wherein the second switch learns the electrical connection state between the microphone and the first signal transceiver by detecting an electrical signal received, through the signal transmission line, by the second signal transceiver, and sends an off-hook/on-hook signal to the processor according to the electrical connection state between the microphone and the first signal transceiver, so as to enable the telephone set to be off-hook/on-hook
• wherein a voice input end of the processor is electrically connected to a voice input end of the second signal transceiver through a third data transmission line and a fourth data transmission line, wherein the third data transmission line and the fourth data transmission line are a positive transmission line and a negative transmission line of a differential circuit in the second signal transceiver, respectively, and the second switch comprises three interfaces, wherein a first interface is connected to the third data transmission line, a second interface is connected to the fourth data transmission line, and a third interface is connected to the processor;
• and
• correspondingly, that the second switch learns the electrical connection state between the microphone and the first signal transceiver by detecting an electrical signal received, through the signal transmission line, by the second signal transceiver, and sending an off-hook/on-hook signal to the processor according to the electrical connection state between the microphone and the first signal transceiver, so as to enable the telephone set to be off-hook/on-hook comprises:
• when the first switch is in a short-circuited state, the first data transmission line and the second data transmission line are short-circuited, and the electrical connection state between the microphone and the first signal transceiver is disconnected, and when the first interface and the second interface of the second switch each detect the electrical signal received, through the signal transmission line, by the second signal transceiver, and determine that voltages of the third data transmission line and the fourth data transmission line are equal, the second switch is short-circuited, and a low level signal is sent to the processor through the third interface, so as to enable the telephone set to be on-hook;
• when the first switch is in a disconnected state, the first data transmission line and the second data transmission line are disconnected, and an electrical connection between the microphone and the first signal transceiver is maintained, and when the first interface and the second interface of the second switch each detect the electrical signal received, through the signal transmission line, by the second signal transceiver, and determine that voltages of the third data transmission line and the fourth data transmission line are not equal, the second switch is disconnected, and a high level signal is sent to the processor through the third interface, so as to enable the telephone set to be off-hook.