Ejection head for ejecting alignment film forming composition
An ejection head for ejecting alignment film forming composition includes multiple nozzles. Each nozzle includes a chamber, a composition source, and a control valve. A liquid transportation pipe and a pusher are disposed on the bottom and the top of the chamber, respectively. The pusher is used for pushing the alignment film forming composition out of the liquid transportation pipe. The composition source is used for transporting the alignment film forming composition to the chamber. The control valve is used for controlling switching of the liquid transportation pipe to control output of the alignment film forming composition. Owing to the control valve and the blowing device, the alignment film forming composition is prevented from condensing on the nozzle and blocking the nozzle or from forming large droplets because of accumulation. In this way, the quality of the alignment film is greatly enhanced owing to uniform spraying and regular output.
1. An ejection head for ejecting alignment film forming composition, comprising a plurality of nozzles disposed on a bottom of the ejection head, each of the plurality of nozzles comprising:
a chamber, comprising a liquid transportation pipe and a pusher disposed on a bottom and a top of the chamber, respectively, the liquid transportation pipe and the pusher corresponding with each other, and the pusher used for pushing the alignment film forming composition out of the liquid transportation pipe;
a composition source connected to a liquid supply pipe disposed on the chamber, for transporting the alignment film forming composition to the chamber;
a control valve disposed on the liquid transportation pipe, for controlling switching of the liquid transportation pipe for restricting output of the alignment film forming composition, the control valve comprising:
a magnetic valve, including a magnetic armature, operatively disposed in the liquid transportation pipe and comprising an active portion and a fixing portion; and
a driver for controlling an operating status of the magnetic valve; and
a blowing device corresponding to an exit of the liquid transportation pipe, for blowing off superfluous alignment film forming composition remaining at the exit of the liquid transportation pipe when the control valve blocks the liquid transportation pipe, the blowing device comprising:
an air tube, disposed on one side of the liquid transportation pipe and connected to the liquid transportation pipe, for being closed after the active portion is opened; and
a blower, connected to the air tube, for expelling air to the air tube.
2. The ejection head as claimed in claim 1 , wherein
a first angle is formed between the active portion of the armature and a cross section of the liquid transportation pipe, so that the armature prevents the alignment film forming composition from flowing out of the liquid transportation pipe, and a second angle formed between the active portion of the armature and the cross section of the liquid transportation pipe, so that the armature allows the alignment film forming composition to flow out of the liquid transportation pipe; and
the magnetic valve, disposed on one side of the liquid transportation pipe and corresponding to the armature, and controlled by the driver to affect magnetic forces that the magnetic valve gives the armature for controlling mutual variations between the first angle and the second angle.
3. The ejection head as claimed in claim 2 , wherein the armature forms transition fit with the liquid transportation pipe.
4. The ejection head as claimed in claim 1 , wherein the pusher is a ceramic resonator.
5. The ejection head as claimed in claim 1 , wherein an inner annular groove is disposed around the liquid transportation pipe in the chamber, the inner annular groove is connected to the liquid supply pipe for temporarily preserving the alignment film forming composition providing by the composition source, a bulge is disposed between the inner annular groove and the liquid transportation pipe for restricting flow direction of the alignment film forming composition flowing from the liquid supply pipe.
6. The ejection head as claimed in claim 1 , wherein the nozzle further comprises a central controller connected to the composition source, the pusher, the driver, and the blower, respectively.