Patent ID: 9256771
Filing Date: 2016-02-09
CPC Classification: G06K,H04B

Claim Text:
1. A high-frequency (HF) tag comprising: an analog circuit unit to communicate with a reader through an analog signal and to receive energy via magnetic coupling with a reader; and a digital circuit unit to be supplied with power from the analog circuit unit, wherein the digital circuit unit supports a sleep mode for the tag to stand by in a low power state after transmitting an identifier (ID) to the reader and a wait mode for controlling random access to the reader; wherein the digital circuit unit comprises: an encoder to encode a reply message to a reader command; a decoder to receive an input of the reader command from the analog circuit unit and to extract information; a protocol processing unit to process inventory and access protocols; a tag state controller to comprise a wait mode controller, a sleep mode controller, and a tag state transition unit; and a memory to store the ID; and wherein the sleep mode controller controls the tag to transition to the sleep mode when a reader command needed for the inventory protocol is received in an acknowledged mode and the wait mode controller controls the tag in the sleep mode to transition to the wait mode using a carrier wave.