H - Electricity – 04 – N
Patent
H - Electricity
04
N
178/3.1
H04N 1/40 (2006.01) H04N 1/405 (2006.01)
Patent
CA 1224421
ABSTRACT In a method and apparatus for production of rastered printing forms with rasters having arbitrary screen angles and screen width, picture elements are exposed on a recording medium by means of a recording element whose expo- sure beam is switched on and off by a control signal. The recording medium is sub-divided into a plurality of surface elements which are exposed or not exposed by the exposure beam as a function of the control signal. All surface elements exposed in a screen mesh of the rotated raster to be recorded form a respective picture element. At least two matrices in the form of matrix memories are provided, the individual matrix elements thereof having a raster threshold or a raster hill allocated to them. The raster thresholds represent the periodic basic structure of a screen mesh and are different for at least one tonal range in the individual matrices. During recording, those matrix elements in the indi- vidual matrices whose positions within the respective matrices correspond to the position of the swept surface ele- ment within the corresponding screen mesh are identified for each surface element swept by the recording element within a screen mesh. The raster thresholds of the identified matrix elements are called in. Controlled by a random generator, one of the called raster thresholds is randomly selected and compared to an image signal value acquired by means of scann- ing the original. The control signal for the exposure beam is derived from the comparison, whereby a decision is made on the basis of the signal comparison as to whether the corresponding surface element is to be exposed or not as part of a picture element.
467598
Dr.-Ing. Rudolf Hell G.m.b.h.
Smart & Biggar
LandOfFree
Improved method and apparatus for producing half-tone... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Improved method and apparatus for producing half-tone..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Improved method and apparatus for producing half-tone... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1316667