Patent ID: 7628464
Filing Date: 2009-12-08
Classification: B41J

Abstract:
1. A liquid drop placing apparatus comprising: an ink jet head; a substrate receiving a liquid drop discharged from the ink jet head; a device for irradiating or reflecting light from a nozzle hole or its vicinity of the ink jet head toward the substrate; a position moving device for controlling a relative position between the ink jet head and the substrate; and a control device for discharging a liquid from the ink jet head; wherein a light-receiving element for recognizing a position of the ink jet head is disposed behind the substrate, when seen from the ink jet head, the substrate has a transparency at least to a degree that the irradiated light or the light reflected from the nozzle hole or its vicinity toward the substrate enters the light-receiving element, and the light-receiving element senses the irradiated light or the light reflected from the nozzle hole or its vicinity toward the substrate, wherein the ink jet head comprises a system for irradiating light from an inside of the nozzle hole discharging the liquid toward the substrate, and wherein the system for irradiating the light from the inside of the nozzle hole toward the substrate comprises the nozzle hole, a pressure chamber for generating a pressure for discharging the liquid from a nozzle, a flow channel for supplying the liquid to the pressure chamber, a container for storing the liquid and a tube for transporting the liquid from the container to the flow channel, and a surface that the liquid contacts is formed of a light-reflecting material, and light from a light source is brought into the container and guided to the nozzle hole.