Liquid discharging apparatus and liquid discharging method

A liquid discharging apparatus for forming dot arrays or dots on a recording medium by discharging droplets from a plurality of liquid discharging portions onto the recording medium while controlling the discharging direction and angle, and changing the dot diameter by the number of the discharged droplets, the apparatus comprising:

• a liquid discharging head having the liquid discharging portions, wherein each of the liquid discharging portions comprises a liquid chamber containing liquid to be discharged and
• a plurality of heating elements arranged in a predetermined direction inside the liquid chamber to generate a bubble in the liquid in the liquid chamber by the application of energy so that the liquid is discharged from a liquid discharging outlet;
• a head driver for controlling the driving of the liquid discharging head;
• a processing unit that converts externally input signals into droplet discharging signals for driving the liquid discharging head and sends the droplet discharging signals to the head driver;
• a storage section for storing information about a defective liquid discharging portion, the information being obtained by checking the discharging states of the droplets discharged from the liquid discharging portions;
• and
• a discharging corrector for generating new droplet discharging signals to reduce the influence of discharging failure of the defective discharging portion,
• wherein the influence of discharging failure of the defective droplet discharging portion is reduced by prohibiting the defective liquid discharging portion from discharging according to the information about the defective liquid discharging portion, and discharging droplets from a liquid discharging portion different from the defective liquid discharging portion while controlling the discharging direction and angle by forming a bubble generation time difference by applying a difference in energy between at least one of the heating elements and at least another one of the heating elements so as to control the discharging direction and angle of the liquid discharged from the liquid discharging outlet based on the value of the bubble generation time difference, according to the new droplet discharging signals generated by the discharging corrector so as to change the dot diameter;
• wherein the new droplet discharging signals are generated only when the diameter of the dots formed on the recording medium by the droplets discharged from the liquid discharging portion different from the defective liquid discharging portion takes a minimum value or is close to the minimum value.