Radio frequency identification tags for digital storage discs

Abstract

A universal low cost radio frequency identification (RFID) tag for use with data storage discs includes an RFID chip, e.g., 2.45 GHz mu-RFID chip, coupled to a linear dipole antenna. The antenna length is reduced in length from the expected length for an optimally tuned antenna corresponding to the operating radio frequency of the RFID chip in a free space environment. The antenna is placed in the tag such as to substantially overlap disc hub area and not extend into data area. The combination of the shortened linear dipole antenna and metallization on the disc to which the tag is applied effectively form a complex antenna operational in the RFID chip's frequency range. The RFID tag works on CDs and DVDs with and without substantially metallized hub areas. The RFID tag is less 0.3 mm thick and may include: ring shape, adhesive material, spacing material achieving uniform thickness, a counterbalance provision.

1 . A disc for storing information comprising:
 a disc structure including a metallized area, said metallized area including an outer metallized data storage area for storing information;   a non-metal inner rim area located inside said metallized area;   a radio frequency linear dipole antenna placed over a portion of said metallized area and over a portion of said non-metal inner ring area, said radio frequency antenna being separated from said metallized area by a non-conductive material located between said antenna and said metallized area; and   a radio frequency identification chip electrically coupled to said linear dipole antenna.   
   
   
       2 . The disc of  claim 1 , wherein the combination of said linear dipole antenna and said portion of the metallized area overlapped by said linear dipole antenna creates an effective antenna tuned to a predetermined frequency range wherein information from said chip can be transmitted through said effective antenna within said predetermined frequency range associated with said radio frequency identification chip. 
   
   
       3 . The disc of  claim 2 , wherein said predetermined frequency range is greater than 2 GHz. 
   
   
       4 . The disc of  claim 3 , wherein said predetermined frequency range is centered on 2.45 GHz. 
   
   
       5 . The disc of  claim 2 , wherein said predetermined frequency range is within the range of 2.25 to 2.75 GHz. 
   
   
       6 . The disc of  claim 2 , wherein said linear dipole antenna has a length that is shorter than the length that would be required to tune the linear dipole antenna to said predetermined frequency range in the absence of the interaction with said metallized area. 
   
   
       7 . The disc of  claim 6 , wherein said of said linear dipole antenna is at least 25 percent shorter than would be required to tune the dipole antenna to said predetermined frequency range in the absence of the interaction with said metallized area. 
   
   
       8 . The disc of  claim 6 , wherein said of said dipole antenna is at least 30 percent shorter than would be required to tune the dipole antenna to said predetermined frequency range in the absence of the interaction with said metallized area. 
   
   
       9 . The disc of  claim 1 , wherein said non-conductive material positioned between said antenna and said metallized area includes:
 at least one non-conductive layer secured to the surface of said metallized area.   
   
   
       10 . The disc of  claim 1 , further comprising:
 balancing material used to balance said disc, said balancing material adding weight to a portion of the disc where the identification chip is not located to counterbalance the weight of said identification chip.   
   
   
       11 . The disc of  claim 10 , wherein a label covers said radio identification chip and said radio frequency antenna. 
   
   
       12 . The disc of  claim 11 , wherein a portion of said label is used as said balancing material. 
   
   
       13 . The disc of  claim 9 , wherein said disc is one of a DVD, a CD, a Blu-Ray disc, and a HD DVD. 
   
   
       14 . A radio frequency identification device for use on a disc which includes an annular disc structure including a metallized area, wherein said metallized area includes an outer metallized data storage area for storing information and a non-metal inner rim area located inside said metallized area the radio frequency identification device comprising:
 a radio frequency linear dipole antenna placed over a portion of said metallized area and over a portion of said non-metal inner ring area, said radio frequency antenna being separated from said metallized area by a non-conductive material positioned between said antenna and said metallized area; and   a radio frequency identification chip electrically coupled to said linear dipole antenna.   
   
   
       15 . The device of  claim 14 , wherein the combination of said linear dipole antenna and said metallized area overlapped by said antenna creates an effective antenna tuned to a predetermined frequency range wherein information from said chip can be transmitted through said effective antenna within said predetermined frequency range associated with said radio frequency identification chip. 
   
   
       16 . The device of  claim 15 , wherein said predetermined frequency range is greater than 2 GHz. 
   
   
       17 . The device of  claim 15 , wherein said linear dipole antenna has a length that is shorter than the length that would be required to tune the linear dipole antenna to said predetermined frequency range in the absence of the interaction with said metallization layer. 
   
   
       18 . A disc for storing information comprising:
 a disc structure including a metallized area, said metallized area including an outer metallized data storage area for storing information;   a non-metal inner rim area located inside said metallized area;   a radio frequency dipole antenna placed over a portion of said metallized area and over a portion of said non-metal inner ring area, said radio frequency antenna being separated from said metallized area by a non-conductive material located between said antenna and said metallized area; and   a radio frequency identification chip electrically coupled to said dipole antenna; and   wherein the combination of said dipole antenna and said portion of the metallized area overlapped by said dipole antenna creates an effective antenna tuned to a predetermined frequency range wherein information from said chip can be transmitted through said effective antenna within said predetermined frequency range associated with said radio frequency identification chip, said dipole antenna being shorter than an antenna length that would be required for the antenna to be tuned to said predetermined frequency range without the interaction with said overlapped metallized area.