Patent ID: 7942494

Claim:
A liquid-discharge-failure detecting apparatus that detects a liquid discharge failure of a droplet of discharged liquid, the liquid-discharge-failure detecting apparatus comprising: a light-emitting element that emits a light beam having an optical axis and having an elliptical cross section, wherein the light-emitting element is arranged to emit the light beam in a direction of the optical axis that intersects a discharge direction in which the droplet is discharged, so that the light beam is emitted onto the droplet; a light-receiving element that is arranged to be externally adjacent to a circumference of the light beam in a direction parallel to a minor axis of the elliptical cross section and to be located close to the optical axis, to receive a scattered light generated by scattering of the light beam by the droplet when the light beam strikes the droplet; and a failure detecting unit that detects the liquid discharge failure by using data pertaining to the scattered light received by the light-receiving element.