Abstract: A high intensity light source comprises a solid dielectric sheet having its back surface in contact with a conducting medium, which is electrically conducted to a fixed potential (such as ground) and its front surface free to receive electric charge to be electrostatically bound to the sheet. In one example, the charge is delivered to the surface by a unipolar Corona discharge arrangement having a plurality of Corona sources at different locations over the surface of the sheet. In order to generate a light output from the source, the electric charge build-up on the surface is discharged as an electric discharge by the rapid application of a switchable voltage to at least a localized region of the surface.

Abstract: A label assembly includes concealed promotional material, and is secured to the product package with the assembly including water-soluble adhesive. The promotional material may be in the form of a "cents-off" coupon or a scratch-off lottery-type game piece. The use of water-soluble adhesive deters tampering prior to purchase of the product, and the coupon or game piece is subsequently exposed when the water soluble adhesive is washed away. The label assembly may include either one, two, or three layers, with the lowermost label being secured to a backing strip or web preparatory to application to the product. When a single layer is employed, it is opaque, and the promotional material is on its lower surface. In a three-layer unit, the game piece may be sandwiched between an outer label having water-soluble adhesive, and the base label which is provided with permanent pressure-sensitive adhesive.