Plastic cap with IC tag and method of attaching IC tag to the cap
A plastic cap with IC tag storing product information provided on the upper surface of a top plate. The top plate is formed by an annular flange and a recessed portion 37 , the recessed portion, including a side wall continuous to the inner circumferential edge of the annular flange and a bottom continuous to the lower end of the side wall. The tag 10 is attached to the annular flange to cover the recessed portion. A gap between the tag and the bottom is maintained to such a degree that the transmission and reception of signals to and from the tag are not interrupted when the back surface of the bottom comes in contact with water.
1. A one-piece plastic cap to be fitted to a mouth of a container which contains a water-containing content, and having a top plate and a skirt wall hanging down from a circumferential edge portion of the top plate and, further, having an IC tag storing product information attached to an upper surface of said top plate, wherein:
said top plate forms a shielding member that maintains a gap between the water-containing content in the container and said IC tag to such a degree that the transmission and reception of signals to and from the IC tag are not interrupted by the water-containing content;
said top plate is formed by an annular flange and a recessed portion continuous to an inner circumferential edge of the annular flange;
said recessed portion includes a side wall continuous to the inner circumferential edge of said annular flange, and a bottom continuous to a lower end of said side wall and the bottom is working as said shielding member; and
said IC tag is attached to said annular flange to cover said recessed portion, and wherein a gap between said IC tag and the bottom of said recessed portion is maintained to such a degree that transmission and reception of signals to and from said IC tag are not interrupted when a back surface of said bottom comes in contact with the water-containing content.
2. The one-piece plastic cap according to claim 1 wherein said IC tag is attached by heat-melt-adhering the circumferential edge portion thereof onto the upper surface of said top plate.
3. The one-piece plastic cap according to claim 1 , wherein a protuberance extending upward is formed on an upper surface of the bottom of said recessed portion.
4. The one-piece plastic cap according to claim 1 , wherein the side wall of the recessed portion of said top plate includes an upper large-diameter portion having a relatively large outer diameter and a lower small-diameter portion having a relatively small outer diameter, an inner ring is formed on the outer circumferential surface of the upper large-diameter portion of said side wall so as to extend downward being separated away from the outer circumferential surface of the lower small-diameter portion, and the mouth of the container is inserted in space between said skirt wall and the inner ring so as to be fixed therein.