Recording apparatus

1. A recording apparatus recording an image on a recording medium, the recording apparatus comprising:

a recording head including a plurality of nozzles ejecting ink onto the recording medium;

a conveying unit that conveys the recording medium;

a carriage on which the recording head is mounted, the carriage reciprocating the recording head for scanning in a direction crossing a conveying direction of the recording medium;

a platen provided at a position facing the recording head along a scanning direction of the recording head, the platen supporting the recording medium;

a sensor mounted on the carriage and detecting a density of an image recorded on the recording medium; and

a detection controller that performs control to record test patterns on the recording medium and read densities of the test patterns using the sensor to thereby detect a non-ejection nozzle of the recording head,

wherein the test patterns are formed by recording a line including a predetermined number of dots in predetermined areas for respective nozzles every plurality of times of conveyance of the recording medium; and

wherein the detection controller reads the test patterns recorded on the recording medium using the sensor, calculates a position of a non-recorded portion in the test patterns, and specifies a position of the non-ejection nozzle based on the calculated position of the non-recorded portion and positions of the nozzles that record the test patterns.

2. The recording apparatus according to claim 1 , wherein the recording head includes a plurality of regions,

wherein the nozzle located in the region records test patterns on a plurality of number of lines arranged in the conveying direction of the recording medium.

3. The recording apparatus according to claim 2 , wherein the test patterns recorded by the nozzle located in the region include end patterns provided on both ends of the test patterns, and the end patterns are recorded by all of the nozzles located in the region.

4. The recording apparatus according to claim 1 , wherein the test patterns are recorded for respective colors of ink, and the sensor is provided for each of the plurality of colors; and

wherein the recording apparatus further comprises:

a blue LED used for the test patterns of black ink and yellow ink;

a red LED used for the test patterns of at least cyan ink; and

a green LED used for the test patterns of at least magenta ink.

5. The recording apparatus according to claim 1 , wherein a conveyance amount of the recording medium when the test patterns are to be recorded on the recording medium is chosen among a plurality of conveyance amounts every scanning of the test patterns.

6. The recording apparatus according to claim 1 , wherein the non-ejection nozzle specified by the detection controller is replaced with another nozzle, and an image is recorded on the recording medium using the another nozzle.

7. The recording apparatus according to claim 1 , wherein the line of the test patterns is recorded in the same position when the carriage moves along a forward path and when the carriage moves along a backward path.