A printing apparatus having a plurality of print element arrays including a plurality of printing elements that are time-share driven achieves both improvement of quality at an image edge, and maintenance of uniformity with respect to inclination error between print element arrays. In a case where the plurality of printing elements of the print element array that discharges ink having the highest density are driven, and dots of image data in the array direction of the printing elements are printed so that the dots are arranged along a specified line in the array direction of the printing elements. Whereas the plurality of printing elements of a different print element array are driven, and dots of the image data in the array direction of those printing elements are printed so that each dot is displaced by a displacement amount for the each dot with respect to the specified line.

An apparatus detects inoperative inkjets during printing. The apparatus operates the printhead or printheads in the printer to form test pattern on a thermal substrate. The heat of the materials used to form the test pattern increase the optical density of the areas where the materials land. The area where the test pattern is formed is imaged and the image data are analyzed to identify inoperative inkjets.

An apparatus detects inoperative inkjets during printing. The apparatus operates the printhead or printheads in the printer to form test pattern on a thermal substrate. The heat of the materials used to form the test pattern increase the optical density of the areas where the materials land. The area where the test pattern is formed is imaged and the image data are analyzed to identify inoperative inkjets.

An example provides a fluid ejection apparatus including a fluid feed slot to supply a fluid to a plurality of drop ejectors, a first rib at a first side of the fluid feed slot and supporting drop ejection circuitry to control ejection of drops of the fluid from the plurality of drop ejectors, and a second rib at a second side, opposite the first side, of the fluid feed slot supporting a thermal sensor to facilitate determination of a temperature of the first rib and the second rib.

A printing apparatus includes: a control unit configured to control a first heating process and a second heating process and configured to control the first heating process and the second heating process to be performed before a printing head starts printing an image on printing medium that is a printing target, wherein the second heating process is performed after the first heating process and before the printing head prints the image, and wherein a first target temperature in the first heating process is higher than a second target temperature in the second heating process.