1. Field of the Invention
The present invention relates to packaging for consumer products. More particularly it relates to packaging incorporating a magnetic tear tape or sealing strip upon which appropriate information may be encoded and read without opening or otherwise damaging the package. The invention is particularly useful for packaged consumer products such as food products and packs of cigarettes.
2. Description of the Prior Art
Consumer products have long been packaged in paper or cardboard packages which are suitably printed so as to identify the product and to provide instructions or other desirable information to the customer. Such packages now frequently display a printed bar code capable of being read by a laser device.
In order to maintain the integrity of the package and to protect the freshness of the product, the paper or cardboard package may be further wrapped with a clear plastic film material which may also bear printed information. For the convenience of the consumer it has long been common to provide a tear strip or tear tape on the plastic film material covering the package. The tear strip or tear tape may be formed from plastic material or a metallic foil and is frequently of a contrasting color. Various forms of tear strips are shown, for example, in Lemelson U.S. Pat. No. 3,426,959.
The art has also developed magnetic tapes which comprise a metal oxide coating on a plastic backing material. The metal oxide coatings are usually brown or black in color while typically the backing material is transparent. Such magnetic tapes have been used to record audio or video signals.
The ability of magnetic tape to record and store information for subsequent read-out has led to its use on credit cards, identification cards, bank cards and the like that are designed to be used with various magnetic reading devices. The use of a colorless oxide coating in combination with an identification card carrying photographic and printed information is disclosed in Mayer U.S. Pat. No. 3,955,295.
In order to identify segments of magnetic tape used to record, for example, audio signals the art discloses the concept of printing indicia such as diagonal lines on the backing material (see Tiger U.S. Pat. No. 2,781,019 and Andrews U.S. Pat. No. 2,782,043). Kinard U.S. Pat. No. 3,729,203 discloses marking the backing material of a reel of magnetic tape to indicate which track is playing while Beaumont U.S. Pat. No. 3,801,750 discloses printing a mark on the non-magnetic face of the tape to indicate a pause between recorded segments. Edge marking of magnetic tape for the same purpose is disclosed in Stone, Jr. et al. U.S. Pat. Nos. 3,810,246, 3,812,538 and 4,018,947. Akashi et al. U.S. Pat. No. 4,135,032 discloses a magnetic tape having a coating on the nonmagnetic side which can easily be marked by a black or dark colored marking device.