Printing method and apparatus therefor

An apparatus of printing an image in a recording area on a photographic recording medium by a printing head that records pixels linearly on the recording medium along a main scan direction, as the recording medium is advanced in a sub scan direction perpendicular to the main scan direction, wherein the printing head may record pixels across a main scanning range that is wider than a maximum length of the recording area in the main scan direction, the apparatus comprising:

• a detection device that receives at least two points corresponding to one side edge of an advancing recording medium to determine positions of the side edge points in the main scan direction;
• a calculation device which receives a signal from said detection device and calculates a relative position of the recording area along the main scanning range of the printing head based on the positions of the side edge points, said calculation device defining a scanning area of the printing head by the main scanning range and a sub scanning range, in accordance with the relative position and dimensions of the recording area, such that the scanning area includes the recording area;
• a print data producing device which receives data from said calculation device and produces print data in a size corresponding to the scanning area from image data of an image to print, such that the print data includes the image data in a location corresponding to a location of the recording area within the scanning area;
• and
• a head driving device which receives data from said print data producing device and drives the printing head with the print data while the recording medium is advanced through the sub scanning range.

An apparatus of printing an image in a recording area on a recording medium by a printing head with an array of heating elements arranged in a main scan direction, as the recording medium is advanced in a sub scan direction perpendicular to the main scan direction, wherein the heating element array has a length that is longer than a maximum length of the recording area in the main scan direction, the apparatus comprising:

• a detection device that receives at least two points corresponding to one side edge of an advancing recording medium to determine positions of the side edge points in the main scan direction;
• a calculation device which receives a signal from said detection device and calculates a relative position of the recording area to the heating element array based on the positions of the side edge points and is adapted to estimate, based on the calculated relative position of the recording area, which of the heating elements will face the recording area while the recording area is moving past the printing head;
• a print data producing device which receives data from said calculation device and produces print data from image data of an image to print and blank data that does not cause the heating element to record a pixel, the print data producing device being adapted to allocate the image data to those heating elements which face the recording area, and allocates the blank data to those heating elements which do not face the recording area;
• and
• a head driving device which receives data from said print data producing device and drives the respective heating elements with the print data.