Patent ID: 7441849
Filing Date: 2008-10-28
Classification: B41J

Abstract:
1. A droplet ejection apparatus, comprising: a platen on which an ejection target medium is conveyed; a head that ejects droplets toward the platen, the head being provided in a reciprocal manner along the platen; a light emitting device that emits a light in an oblique direction toward the platen within a plane including a straight line along a moving direction of the head and a normal line with respect to the platen; a light receiving device that receives the light emitted from the light emitting device and regularly reflected by one of the platen and the ejection target medium; and a calculation device that calculates a distance between the one of the platen and the ejection target medium, and the head, based on a position of the head at which the light receiving device receives the light during a movement of the head, one of the light emitting device and the light receiving device being adapted to reciprocably move integrally with the head, and the other one of the light emitting device and the light receiving device being provided separately from the head, such that the one device moves towards or away from the other device as the head is provided in a reciprocal manner along the platen.