Thermal recording method

Abstract

Abstract PURPOSE:To record an image having variations in both resolution and gradation by using a single head, by using a row of heatint elements in such a form as to provide a resolution equal to a natural number times of the least common multiple of resolutions for which the head is to be used in common, in a thermal recording method for recording a gradation image. CONSTITUTION:According to this invention, a thermal recording head 8 comprises a row of heating elements 7 which are arranged in accordance with the desired printing and in such form as to provide a resolution equal to m (m is a natural number larger than 1) times of the least common multiple of the resolutions for which the head 8 is to be used in common. When the highest of said resolutions is equal to the least common multiple of them, the elements 7 is so arranged as to provide a resolution equal to n (n is a natural number larger than 1) times of the highest resolution. In addition, a gradation recording is performed by combining a gradation presenting means based on 3-level density and that based on regulation of dot area factor. Accordingly, by using a single thermal recording head, images of different resolutions can be recorded and a gradation image having at least 5 gradation levels can be obtained stably and easily. The number of dots for one picture element is selected by a resolution selecting circuit 2 in accordance with the resolution, and a plurality of gradation patterns of the same gradation are selected by a gradation pattern generating circuit 3 using random numbers.

Inventors

• 👤 Yukio Tokunaga
• 👤 Kazunari Kubota
• 👤 Yasuhisa Ikeda
• 👤 Shigeki Ishii

Bibliographic Details