Ink Jet Recording Apparatus Prepulse Control for Stable Discharge
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Solution Overview
Problem
The existing thermal ink jet recording apparatuses face challenges in maintaining a stable ink discharge due to temperature fluctuations of the recording head, leading to density unevenness and image quality issues, as the energy amount for ink foaming varies, causing prefoaming and unstable discharge.
Innovation Solution
An ink jet recording apparatus with a temperature detection unit, acquisition unit, specification unit, and control unit that determine a pulse width upper limit for the prepulse to prevent minute foaming, ensuring stable discharge by controlling the energy generation elements with a drive pulse having a pulse width equal to or less than the specified upper limit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the pulse width of the prepulse is increased to heat the ink more effectively, then the ink discharge amount increases, but minute foaming occurs and discharge stability deteriorates
Solution Approach 1:
The pulse width upper limit value is dynamically determined based on the detected recording head temperature. As temperature fluctuates during recording operations, the control unit adjusts the prepulse pulse width accordingly, selecting different pulse width upper limit values from a table that corresponds to different temperature ranges. This dynamic adjustment prevents minute foaming while maintaining adequate ink heating across varying temperature conditions.
Solution Approach 2:
The invention changes the parameter of pulse width based on temperature conditions. By establishing a relationship between recording head temperature and pulse width upper limit value, the system optimizes the prepulse duration to prevent minute foaming. The pulse width is specifically controlled to be equal to or less than the determined upper limit value, transforming a fixed parameter into a variable one that adapts to thermal conditions.
2Productivity
If the temperature range of the recording head is extended to accommodate higher recording speeds and density, then productivity increases, but the difficulty of maintaining stable discharge control increases
Solution Approach 1:
The system performs preliminary determination of the pulse width upper limit value based on the detected recording head temperature before executing the ink discharge operation. By pre-establishing the appropriate pulse width limit corresponding to the current temperature, the system prepares the optimal control parameters in advance, enabling stable discharge control even across extended temperature ranges required for high-speed recording.
Solution Approach 2:
The invention introduces an intermediary control mechanism - the pulse width upper limit value determination unit - that mediates between the temperature detection and the actual discharge control. This intermediary layer processes the temperature information and translates it into appropriate pulse width constraints, facilitating stable control across wide temperature variations without direct complex control algorithms.
3Stability of the object's composition
If the prepulse is applied with sufficient energy to heat the ink, then the ink viscosity decreases and discharge improves, but air bubbles are generated and film boiling is disrupted
Solution Approach 1:
The invention applies preliminary anti-action by limiting the prepulse energy to prevent minute foaming before it can disrupt the main discharge process. The pulse width upper limit value is specifically determined to prevent air bubble generation during the prepulse phase, while still providing sufficient heating to reduce ink viscosity. This preemptive constraint on pulse width prevents the harmful effect of minute foaming from occurring in the first place.
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 solution prevents the generation of minute foams, stabilizes the ink discharge operation, and widens the temperature range for discharge control, preventing discharge failures and maintaining a constant ink discharge amount.
Implementation Method 1
an energy generation element (hereinafter, also referred to as a heater) provided so as to correspond to the discharge port causes film boiling of the ink
Implementation Method 2
Thermal energy generated by an energy generation element (hereinafter, also referred to as a heater) provided so as to correspond to the discharge port causes film boiling of the ink
Implementation Method 3
a temperature sensor, reads a temperature of a recording head
Data Source
AI summary
The present invention relates to an ink jet recording apparatus including a recording head including a plurality of energy generation elements configured to generate thermal energy. The ink jet recording apparatus includes a specification unit and a control unit. The specification unit specifies a pulse width upper limit value of a prepulse during a recording operation based on a minimum pulse width by which ink is discharged by applying a drive pulse to the energy generation elements and a temperature of the recording head during the recording operation. The control unit controls the energy generation elements to be driven using a drive pulse of a prepulse with a pulse width equal to or less than the pulse width upper limit value.