Title:
【発明の名称】印刷胴エングレービング
Document Type and Number:
Japanese Patent JPH05507185
Kind Code:
A
Abstract:
PCT No. PCT/GB91/00662 Sec. 371 Date Dec. 28, 1992 Sec. 102(e) Date Dec. 28, 1992 PCT Filed Apr. 26, 1991 PCT Pub. No. WO91/16784 PCT Pub. Date Oct. 31, 1991.When laser engraving flexographic and rotary screen printing cylinders half-tones are generated by providing a series of regularly spaced cells (1) including dots or pits (3) which collectively are referred to as a screen. By varying the ratio between the areas of the dots or pits (3) and the cells (1) the intensity of the half-tone is varied. A laser engraving machine for engraving such printing cylinders includes variable timing means (37, 38) which are triggered by their engraving head (13) crossing into each cell (1) and which generate a variable time delay (D) to determine the start time of the laser engraving in each pass of each cell (1) and also to determine the duration (P) of the time for which the laser is turned ON to engrave material during each pass of each cell.
Inventors:
Pollard, Brendan Thomas
Marsh, Terence Edward John
Marsh, Terence Edward John
Application Number:
JP50822591A
Publication Date:
October 14, 1993
Filing Date:
April 26, 1991
Export Citation:
Assignee:
Zed Instruments Limited
International Classes:
B41C1/14; B41C1/05; H04N1/23; H04N1/405; (IPC1-7): H04N1/40; B41C1/14; H04N1/23
Attorney, Agent or Firm:
Kazuhiro Kitazawa (2 outside)