Inkjet Recording Head Current Detection for Discharge Defects
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Solution Overview
Problem
Conventional inkjet recording apparatuses cannot detect nozzle clogging or air bubble entry during printing, leading to potential discharge defects and compromised image quality.
Innovation Solution
Incorporating electrodes adjacent to nozzle holes in the inkjet recording head, which apply a voltage and detect current flow to determine if ink is being discharged correctly, allowing for real-time detection of discharge defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional purging or flushing operations are performed to prevent nozzle clogging, then nozzle reliability is improved, but these operations cannot detect clogging during printing and require post-printing verification
Solution Approach 1:
The patent applies feedback by using current detecting means to continuously monitor the electrical state between electrodes during printing operations. When ink discharge is abnormal (indicating clogging or air bubble), the system detects this through changes in current flow and provides real-time feedback to stop printing, preventing defective output without requiring post-printing verification.
Solution Approach 2:
The patent replaces mechanical detection methods (requiring physical movement to detection positions) with an electrical measurement system. By measuring current flow between electrodes that are electrically coupled to the ink discharge system, the patent enables non-contact, real-time detection of discharge defects during printing operations.
2Measurement precision
If the inkjet recording head is moved to a predetermined detection position for clogging detection, then detection accuracy is improved, but printing operations cannot be performed during detection
Solution Approach 1:
The patent merges the detection function with the printing function by integrating current detecting means into the inkjet recording head structure. This allows both printing and detection to occur simultaneously at the same position, eliminating the need to move the recording head to separate detection positions and thus maintaining continuous printing operations.
Solution Approach 2:
The inkjet recording head is designed with multi-functionality, serving both as the printing device and the detection device. The electrodes and current detecting means are built into the recording head structure, enabling it to perform both ink discharge and real-time discharge defect detection during the same printing operation without requiring separate dedicated detection equipment.
3Difficulty of detecting and measuring
If electrodes are arranged adjacently with nozzle holes to enable real-time detection, then detection capability during printing is improved, but device structure becomes more complex
Solution Approach 1:
The electrodes serve dual purposes: they are integral to the ink discharge mechanism (acting as part of the piezoelectric actuation system) and simultaneously function as sensing elements for detecting discharge defects. This multi-functionality reduces the need for separate dedicated detection components, thereby limiting the increase in structural complexity despite adding detection capability.
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
Enables immediate detection and correction of discharge defects during printing, preventing clogging and air bubble issues, thus ensuring consistent inkjet performance and image quality.
Implementation Method 1
an actuator such as a piezoelectric element, an electrostrictive element, or a heating element. With local boiling of an ink caused by bending or heat of the actuator, ink droplets are discharged from the nozzles.
Implementation Method 2
an actuator such as a piezoelectric element, an electrostrictive element, or a heating element. With local boiling of an ink caused by bending or heat of the actuator, ink droplets are discharged from the nozzles.
Implementation Method 3
an actuator such as a piezoelectric element, an electrostrictive element, or a heating element.
Data Source
AI summary
A recording head includes a main body and electrodes. The main body has a nozzle plate. The electrodes are arranged on the front surface of the nozzle plate. A current sensor is connected to the electrodes through connection terminals, and measures a current value flowing in the respective electrodes. The electrodes correspond respectively to the colors of inks to be discharged. Each of the electrodes is separated from the edge of the nozzle hole by 1 μm to 5 μm. The nozzle plate has a water repellent layer on the front surface. The electrodes connect a plurality of nozzle holes in series.