Camouflaging method of latent image for copy prevention on printed matter

Abstract

Abstract PURPOSE:To make it evident that a sheet of paper is a copy by using an overprinting plate having a pattern which interferes with ground tint (line-like) of a latent image plate to form moire fringes, and overprinting hypochromic data which is not reproduced by a copying machine on a form surface. CONSTITUTION:The latent plate 2 which has a latent image 3 displaying COPY consisting of 150-line and 10% dots and a background 4 consisting of about 50- 60-line and 10% ground tint (line-like) on the white ground at the circumference of the latent image is used for hyperchromic printing on the surface of a form 1. Then, the overprinting plate 5 having the waveform pattern 6 consisting of parallel lines which form moire fringes when interfering with the ground tint (line-like) of the background 4 is used to perform hypochromic overprinting which is not reproduced by the copying machine on the form surface, camouflaging the latent image. Consequently, the moire fringes which are glaring to the naked eye are formed on the surface of the printed matter, so the presence of the latent image 3 becomes hard to discriminate and only the background 4 is reproduced on a copying machine without the latent image 3 nor pattern 6, distinguishing between the latent image 3 and background 4.

Inventors

• 👤 Shohei Tsuchiya
• 👤 土屋　正平

Bibliographic Details