Inkjet Actuator Timing Control for Ejection Consistency
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Solution Overview
Problem
Inkjet recording apparatuses using the fill-before-fire method face challenges in maintaining consistent ink ejection speed due to variations in actuator deformation, leading to reduced reproducibility of images.
Innovation Solution
The actuator is controlled such that the value of To/Tc falls within the range from 0.51 to 0.54, which helps in minimizing the variation in ink ejection speed relative to the degree of actuator deformation, thereby maintaining image reproducibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the fill-before-fire method is used with conventional timing control, then ink ejection can be achieved, but variation in ink ejection speed becomes large relative to variation in actuator deformation
Solution Approach 1:
The patent applies parameter changes by optimizing the timing parameter To (actuator deformation time) relative to the characteristic vibration period Tc of ink in the individual ink passage. By controlling To/Tc to fall within the specific range of 0.51 to 0.54, the invention minimizes the amplification of actuator deformation variations on ink ejection speed, thereby improving ejection consistency and image reproducibility.
2Ease of manufacture
If actuator deformation varies due to manufacturing variations, then ink ejection can occur, but ink ejection speed varies widely from actuator to actuator
Solution Approach 1:
The invention changes the timing parameter To such that To/Tc is within 0.51 to 0.54, which reduces the sensitivity of ink ejection speed to actuator deformation variations. This allows actuators with typical manufacturing variations to produce consistent ink ejection speeds without requiring ultra-precise actuator fabrication.
Solution Approach 2:
The invention performs preliminary optimization of the timing parameter To before ink ejection occurs. By pre-determining that To/Tc should fall within 0.51 to 0.54 based on the characteristic vibration period Tc, the system prepares the ink and actuator timing in advance to minimize the impact of actuator variations on ejection speed.
3Productivity
If the timing parameter To is not optimized relative to Tc, then ink ejection can be achieved, but reproduction quality of images deteriorates
Solution Approach 1:
The patent optimizes the timing parameter To relative to the characteristic vibration period Tc by controlling To/Tc to fall within 0.51 to 0.54. This parameter optimization simultaneously maintains efficient ink ejection while improving image reproduction quality by reducing ejection speed variation.
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 control condition ensures that the ink ejection speed variation is kept within permissible bounds, enhancing the reproducibility of images printed and improving the efficiency of the inkjet recording process.
Implementation Method 1
an actuator is provided in the inkjet head for applying a pressure to ink in the individual ink passage. Part of ink to which the pressure has been applied by deformation of the actuator is ejected from the corresponding nozzle.
Implementation Method 2
a pressure wave is generated by applying the pressure to ink in the pressure chamber, and as a result, proper oscillation is generated in the individual ink passage due to the pressure wave.
Implementation Method 3
proper oscillation is generated in the individual ink passage due to the pressure wave
Data Source
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AI summary
A method and an inkjet recording apparatus wherein an actuator can selectively take a first state in which the volume of a pressure chamber (10) is V1 and a second state in which the volume of the pressure chamber (10) is V2 larger than V1. The actuator changes from the first state into the second state and then changes back into the first state to eject ink from an ejection port (8). A controller controls the actuator such that To/Tc falls within a range from 0.51 to 0.54. To represents the time period from a time point at which the actuator starts to change from the first state into the second state, to a time point at which the actuator starts to change from the second state into the first state. Tc represents the period of proper oscillation of ink filling up an individual ink passage (32).