Method and an apparatus to record with plural gradation for magnetic printing machine
AssigneeIwatsu Electric Co., Ltd.
InventorNorio Kokaji
Life of this patent
Estimating the term…
Abstract
In a magnetic printing machine including at least two recording frequency generators which generate at least two recording frequencies with close each other, a recording current applied to a recording head for the same gradation level is switched among at least two recording frequencies every time a predetermined number of pixels are recorded.
Claims6
A method of recording a magnetic printing machine which records an image on a recording drum with one recording head, comprising the steps of:
- determining a first recording frequency based on a digital signal that represents a certain gradation level of an original pixel;
- determining a second recording frequency which is close to said first recording frequency based on said digital signal;
- and
- switching a recording frequency from said first recording frequency to said second recording frequency, or vice versa, at every time when a predetermined number of pixels have been recorded.
A method of recording for a magnetic printing machine which records an image on a recording drum with one recording head, comprising steps of:
- determining a first frequency demand based on a digital signal which represents a certain gradation level of an original pixel;
- determining a second frequency demand which is close to said first frequency demand based on a digital signal which represents the same gradation level as said original pixel;
- generating clock pulses synchronizing with rotational speed of a recording drum;
- generating a switching signal every time said clock pulses are counted to a predetermined number;
- switching a recording frequency which is determined from said first frequency demand or said second frequency demand every time said switching signal is generated;
- generating recording pulse train a frequency thereof is determined in accordance with said recording frequency;
- amplifying said recording pulse train with a power amplifier;
- and
- recording said amplified recording pulse train on said recording drum.
An apparatus for recording magnetically an image on a recording drum with one recording head, comprising:
- means for determining a first frequency demand based on a digital signal which represents a certain gradation level of an original pixel;
- means for determining a second frequency demand which is close to said first frequency demand based on a digital signal which represents the same gradation level as said original pixel;
- means for generating clock pulses synchronizing with rotational speed of a recording drum;
- means for generating a switching signal every time said clock pulses are counted to a predetermined number;
- means for switching a recording frequency determined from said first frequency demand or said second frequency demand every time said switching signal is generated;
- means for generating recording pulse train a frequency thereof is determined in accordance with said recording frequency;
- means for amplifying said recording pulse train with a power amplifier;
- and
- means for recording said amplified recording pulse train on said recording drum.
Dependencies are inferred from the claim text.