Full color printer with a He‐Cd+ white‐light laser

A high resolution full color printer has been developed incorporating a He‐Cd+ white‐light laser, acousto‐optic modulators, a Galvano scanner, and a circular arc recording platen on a fine translation stage. The laser oscillates at three primary colors and is controlled to be within 1% intensity stability. The spot size of the laser beam on the recording platen is improved to be 50 μm in diameter while the positioning accuracy for both horizontal and vertical scans are achieved to be better than 25 μm. The exposing energy densities on the recording surface for red, green, and blue are measured to be 4.3, 8.4, and 8.4 erg/cm2, respectively. The energy densities exceed the required exposure energy for Polacolor ER 8×10 Land film. A ‘‘reversible coding method’’ has been applied to shorten the data process time for 153.6 Mbytes image data. As the result, a 250×200 mm2 color print can be produced in 2 min. To evaluate chromaticity of the color prints, a color estimator that consists of a colorimeter, a persona...