US 8,411,308 B2 · Printing machine and ejection control method for the same

Abstract

Disclosed is a printing machine comprising: encoders (311 and 312) configured to detect respective angular velocities of a drive roller and a driven roller as a travel speed of core members inside a transfer belt (160); a DSP (321) configured to extract from a temporal variation in a ratio of the measured speed at each roller speed ratio data (profile data) having a frequency corresponding to the speed ratio of a core portion; profile data memory (332) configured to store the profile data; and a head controller (334) configured to control the timing at which each image is formed by a head unit (110) on the basis of the profile data so that positional deviation among multiple images on the transfer belt (160) may be reduced. The head unit (110) forms multiple images on a record medium under the control of the head controller (334). Thus, an ink misalignment at the time of printing can be prevented with high accuracy by recording a change in the core members inside the belt as a profile, using this profile, and reducing memory usage and arithmetic processing load.

Claims16

Dependent claims

A printing machine comprising:

a transfer belt of an endless form applied over support rollers,
driving means for rotating the support rollers to move the transfer belt in an endless manner, and
ink heads for forming images to overlap on a record sheet on the transfer belt,
the printing machine further comprising:
speed measuring means for measuring travel speeds at a pair of measurement points set on a combination of the transfer belt and the support rollers;
an extractor for working with a temporal variation in ratios of speeds between the measurement points measured by the speed measuring means to extract a set of speed ratio data having frequencies corresponding to the ratios of the speeds;
a storage for storing the set of speed ratio data as extracted;
print control means for working with the set of speed ratio data stored in the storage to control timings of formation of images by the ink heads for reduction in positional deviation among the images on the transfer belt;
and
the ink heads for working with the print control means to form images on a record medium.

7 more elements

A method for controlling ejection of ink heads in a printing machine, the printing machine comprising:

a transfer belt of an endless form applied over support rollers;
driving means for rotating the support rollers to move the transfer belt in an endless manner;
and
ink heads for forming images to overlap on a record medium on the transfer belt,
the method being further comprising:
a speed measuring step of measuring travel speeds at a pair of measurement points set on a combination of the transfer belt and the support rollers;
a speed extracting step of working with a temporal variation in the travel speeds at the respective measurement points measured in the speed measuring step to extract a set of speed ratio data having frequencies corresponding to the ratios of speeds;
and
a print control step of, upon performance of print processing, measuring a travel speed at any one of the pair of the measurement points, correcting a result of the measurement on a basis of the set of speed ratio data, and controlling timings of formation of images by the ink heads for reduction in positional deviation among the images on the transfer belt.

6 more elements

Dependencies are inferred from the claim text.

Printing machine and ejection control method for the same

Life of this patent

Printing machine and ejection control method for the same

Life of this patent

Abstract

Claims16