Liquid ejection apparatus, liquid ejection system, and liquid ejection method

A liquid ejection system including at least one liquid ejection apparatus, the liquid ejection apparatus including

• a first liquid ejection head unit configured to eject liquid onto one side of a conveyed object, and
• a second liquid ejection head unit configured to eject liquid onto the one side of the conveyed object, the second liquid ejection head unit being arranged downstream of the first liquid ejection head unit in a conveying direction of the conveyed object, the liquid ejection system comprising:
• a first support member arranged upstream of the first liquid ejection head unit in the conveying direction;
• a second support member arranged downstream of the first liquid ejection head unit and upstream of the second liquid ejection head unit in the conveying direction;
• a third support member arranged downstream of the first liquid ejection head unit and upstream of the second liquid ejection head unit in the conveying direction;
• a fourth support member arranged downstream of the second liquid ejection head unit in the conveying direction;
• a first sensor configured to detect a position, a moving speed, and an amount of movement of the conveyed object, the first sensor being installed between the first support member and the second support member, and being installed on an opposite side of the conveyed object from the first liquid ejection head unit;
• a second sensor configured to detect a position, a moving speed, and an amount of movement of the conveyed object, the second sensor being installed between the third support member and the fourth support member, and being installed on an opposite side of the conveyed object from the second liquid ejection head unit;
• and
• a controller configured to control a liquid ejection timing at which the second liquid ejection head ejects liquid, based on the outputs of the first sensor and the second sensor.

A liquid ejection apparatus comprising:

• a first liquid ejection head unit configured to eject liquid onto one side of a conveyed object;
• a second liquid ejection head unit configured to eject liquid onto the one side of the conveyed object, the second liquid ejection head unit being arranged downstream of the first liquid ejection head unit in a conveying direction of the conveyed object;
• a first support member arranged upstream of the first liquid ejection head unit in the conveying direction;
• a second support member arranged downstream of the first liquid ejection head unit and upstream of the second liquid ejection head unit in the conveying direction;
• a fourth support member arranged downstream of the second liquid ejection head unit in the conveying direction;
• a first sensor configured to detect a position, a moving speed, and an amount of movement of the conveyed object, the first sensor being installed between the first support member and the second support member, and being installed on an opposite side of the conveyed object from the first liquid ejection head unit;
• a second sensor configured to detect a position, a moving speed, and an amount of movement of the conveyed object, the second sensor being installed between the second support member and the fourth support member, and being installed on an opposite side of the conveyed object from the second liquid ejection head unit;
• and
• a controller configured to control a liquid ejection timing at which the second liquid ejection head ejects liquid, based on outputs of the first sensor and the second sensor.