Inkjet Nozzle Plate Stepped Inner Surface Design
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Solution Overview
Problem
Conventional inkjet heads with tapered nozzles face challenges in achieving precise nozzle length, leading to variations in ink volume ejected, which deteriorate print quality due to inaccuracies in the dry-etching process and machine performance.
Innovation Solution
An inkjet head with a nozzle plate featuring a stepped inner surface, where the length of the outlet (Ln1) is optimized to be between 0.5 and 1.0 times the ink volume (V) divided by the outlet's sectional area (C1), ensuring consistent ink ejection characteristics and high print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a tapered nozzle is used, then ink ejection is facilitated, but manufacturing precision deteriorates due to difficulty in drilling accurate tapered nozzles
Solution Approach 1:
The nozzle is divided into two distinct sections: a tapered inlet section for ink intake and a straight outlet section for ink ejection. This segmentation allows each section to be optimized independently - the inlet for smooth ink flow and the outlet for precise length control through standard drilling processes, thereby resolving the contradiction between ease of ink ejection and manufacturing precision.
2Ease of manufacture
If dry-etching process is used to drill nozzles, then manufacturing is improved, but manufacturing precision deteriorates due to variation in nozzle size
Solution Approach 1:
The nozzle structure separates the difficult-to-control tapered inlet portion from the critical-length straight outlet portion. The outlet section, which requires precise length control, can be manufactured using standard drilling processes that offer better dimensional control, while the inlet section accommodates the variations introduced by dry-etching processes.
3Ease of manufacture
If nozzle length varies, then manufacturing is simplified, but ink ejection characteristics deteriorate due to fluctuations in ink volume
Solution Approach 1:
By dividing the nozzle into inlet and outlet sections with distinct functions, the design isolates the critical ink ejection function to the straight outlet section. This section's length can be precisely controlled during manufacturing, ensuring consistent ink volume ejection even when the overall nozzle dimensions vary slightly due to manufacturing tolerances.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration stabilizes the ink ejection characteristics and maintains high print quality by controlling the variation in nozzle length, even if slight variations occur, effectively preventing fluctuations in ink volume and ensuring consistent droplet formation.
Implementation Method 1
When a drive voltage is applied to the electrodes, the two side walls faced with each other, interposing one ink pressure chamber, deform in chevron to mutually approach and move apart, for example. Such deformation of the side walls causes ink filled in the one ink pressure chamber to be compressed.
Data Source
AI summary
Disclosed is an ink jet head for ejecting an ink droplet to form an image on a recording medium, including a pressure chamber to which ink is supplied, an actuator which applies a pressure on the ink filled in the pressure chamber to eject the ink droplet, a circuit applying to the actuator a drive-waveform for sequentially ejecting one or more ink droplets to form one pixel, the one ink droplet having V in volume, and a nozzle plate which has a nozzle fluidly communicating with the pressure chamber to eject ink droplet therefrom, the nozzle having a stepped inner surface shaped to include an inlet communicating with the pressure chamber and having a first sectional area in an orthogonal plane to ink-ejecting direction, and to include an outlet communicating with the inlet and having a length Ln1 in the ink-ejecting direction and a second sectional area C1 in the orthogonal plane smaller than the first sectional area, the Ln1, C1, and V being satisfied the relationship of 0.5≦Ln1/(V/C1)≦1.0. The ink jet head provides a high print quality while preventing a variation in volume of ink droplet ejected from the nozzle.