Colour printer

Claim 2

A deviation test pattern according to claim 1, characterized in that said plurality of printing units (21Y, 21M, 21C, 21B) is arranged in a paper feeding direction (P), and said deviation-measuring direction is set perpendicular to the paper feeding direction (P).

Claim 3

A deviation test pattern according to claim 1, characterized in that said plurality of printing units (21Y, 21M, 21C, 21B) is arranged in a paper feeding direction (P), and said deviation-measuring direction coincides with the paper feeding direction (P).

Claim 4

A deviation test pattern according to claim 1, characterized in that a difference between the pitch M and the pitch N corresponds to one dot of an image printed by each of said printing units (21Y, 21M, 21C, 21B).

Claim 5

A deviation test pattern according to claim 1, characterized by further comprising: a first detailed (SC1) scale section composed of the reference and difference scales in which the pitch N is set shorter than the pitch M by a predetermined length; and a second detailed scale section (SC2) composed of: a reference scale printed by said reference printing unit (21B) and having a plurality of scale bars (RB) arranged at a pitch M in the deviation-measuring direction, and a difference scale printed adjacent to and in parallel to said reference scale by the printing unit other than said reference printing unit (21B) and having a plurality of scale bars (DB) arranged in the deviation-measuring direction at a pitch L, which is longer than the pitch M by a predetermined length.

Claim 6

A deviation test pattern according to claim 5, characterized by further comprising a schematic scale section (SC0) composed of: a reference scale printed by said reference printing unit (21B) and having a plurality of scale bars (RB) arranged in the pitch M in the deviation-measuring direction, and a scale bar (DB) printed adjacent to and in parallel to said reference scale by the printing unit other than said reference printing unit (21B), and set to be in alignment with a central scale bar (RB) of said reference scale.

Claim 8

A method according to claim 7, characterized in that said plurality of printing units (21Y, 21M, 21C, 21B) is arranged in a paper feeding direction (P), and said deviation-measuring direction is set perpendicular to the paper feeding direction (P).

Claim 9

A method according to claim 7, characterized in that said plurality of printing units (21Y, 21M, 21C, 21B) is arranged in a paper feeding direction (P), and said deviation-measuring direction coincides with the paper feeding direction (P).

Claim 10

A method according to claim 7, characterized in that a difference between the pitch M and the pitch N corresponds to one dot of an image printed by each of said printing units (21Y, 21M, 21C, 21B).

Claim 11

A printer device comprising: a plurality of printing units (21Y, 21M, 21C, 21B) arranged to print overlaid images; and a print control circuit (CT1, CT2) for controlling said printing units (21Y, 21M, 21C, 21B) to print the overlaid images; characterized in that said print control circuit has a test control circuit (CT1, CT2) for controlling one reference printing unit (21B) among said plurality of printing units (21Y, 21M, 21C, 21B) in a test mode to print a reference scale having a plurality of scale bars (DB) arranged in a deviation-measuring direction at a pitch M, and controlling a printing unit other than said reference printing unit (21B) in the test mode to print a difference scale adjacent to and in parallel to the reference scale and having scale bars (DB) arranged in the deviation-measuring direction at a pitch N, which slightly differs from the pitch M; thereby obtaining a deviation test pattern formed of said reference scale and said difference scale.

Claim 12

A printer device according to claim 11, characterized in that said plurality of printing units (21Y, 21M, 21C, 21B) is arranged in a paper feeding direction (P), and said deviation-measuring direction is set perpendicular to the paper feeding direction (P).

Claim 13

A printer device according to claim 11, characterized in that said plurality of printing units (21Y, 21M, 21C, 21B) is arranged in a paper feeding direction (P), and said deviation-measuring direction coincides with the paper feeding direction (P).

Claim 14

A printer device according to claim 11, characterized in that a difference between the pitch M and the pitch N corresponds to one dot of an image printed by each of said printing units (21Y, 21M, 21C, 21B).

Claim 15

A printer device according to claim 11, characterized in that said plurality of printing units (21Y, 21M, 21C, 21B) has a line printing head set perpendicular to the paper feeding direction (P), said deviation-measuring direction coincides with the paper feeding direction (P), and said test control circuit has means for performing a control of forming a pair of the deviation test patterns near sides of paper in a direction perpendicular to the paper feeding direction (P).

Claim 16

A printer device comprising: a plurality of printing units (21Y, 21M, 21C, 21B) arranged to print overlaid images; and a print control circuit (CT1, CT2) for controlling said printing units (21Y, 21M, 21C, 21B) to print the overlaid images; characterized in that said print control circuit has a test control circuit (CT1, CT2) for controlling one reference printing unit (21B) among said plurality of printing units (21Y, 21M, 21C, 21B) in a test mode to print a reference scale having a plurality of scale bars (RB) arranged in a deviation-measuring direction at a pitch M, controlling a printing unit other than said reference printing unit (21B) in the test mode to print a difference scale adjacent to and in parallel to the reference scale and having scale bars (DB) arranged in the deviation-measuring direction at a pitch N, which slightly differs from the pitch M, measuring a deviation of a printing position of said other printing unit with respect to a printing position of said reference printing unit (21B) in the deviation-measuring direction from a deviation test pattern formed of said reference scale and said difference scale, and changing the printing position of said other printing unit in accordance with a result of the measurement.

Claim 17

A printer device according to claim 16, characterized in that said print control circuit has a second test control circuit (CT1, CT2) for controlling one reference printing unit (21B) among said plurality of printing units (21Y, 21M, 21C, 21B) in a test mode to print a reference scale having a plurality of scale bars (RB) arranged in anther deviation-measuring direction at a pitch M, controlling a printing unit other than said reference printing unit (21B) in the test mode to print a difference scale adjacent to and in parallel to the reference scale and having scale bars (DB) arranged in the other deviation-measuring direction at a pitch N, which slightly differs from the pitch M, measuring a deviation of a printing position of said other printing unit with respect to a printing position of said reference printing unit (21B) in the other deviation-measuring direction from a second deviation test pattern formed of said reference scale and said difference scale, and changing the printing position of said other printing unit in accordance with a result of the measurement.