Inkjet Head Inspection Using Pseudo Drive Frequency Switching
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Solution Overview
Problem
Conventional inkjet printing apparatuses inefficiently inspect head abnormalities by printing test patterns multiple times, consuming excess recording media and ink when switching transport speeds.
Innovation Solution
An inkjet printing apparatus uses a controller to generate a test drive signal combining different waveforms at varying ratios while maintaining a constant transport speed, allowing inspection of head abnormalities without changing the transport speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the transport speed of the recording medium is switched to inspect head abnormalities at different drive frequencies, then the inspection coverage is improved, but the inspection time and resource consumption increase significantly
Solution Approach 1:
The patent changes the drive signal frequency parameter while keeping the transport speed constant. The control unit generates drive signals with different frequencies (first frequency and second frequency) to inspect the head at multiple drive frequencies without changing the recording medium transport speed, thus resolving the contradiction between inspection coverage and inspection time
Solution Approach 2:
The patent uses periodic drive signals with different frequencies to excite the piezoelectric element and inspect the head. By applying periodic signals at first and second frequencies sequentially during a single pass, the system achieves comprehensive inspection without requiring multiple passes at different transport speeds
2Adaptability or versatility
If the transport speed of the recording medium is switched to inspect head abnormalities at different drive frequencies, then the inspection coverage is improved, but the consumption of recording media and ink increases
Solution Approach 1:
The patent changes the drive signal frequency parameter while keeping the transport speed constant. This allows inspection at multiple drive frequencies using a single recording medium pass, eliminating the need to print multiple test patterns on separate media, thus reducing both recording media and ink consumption
Solution Approach 2:
The patent combines multiple inspection operations into a single pass. By merging the inspection at first frequency and second frequency into one continuous operation with constant transport speed, the system reduces the total amount of recording media and ink that would be consumed if separate passes were required
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
Rapid and efficient head inspection with reduced ink and paper consumption by simulating drive frequency changes, facilitating identification of nozzle abnormalities.
Implementation Method 1
at least one piezoelectric element for applying pressure to ink in the ink chamber
Data Source
AI summary
A controller for an inkjet printing apparatus outputs a test drive signal for printing a test pattern to a piezoelectric element of a head. The test drive signal includes a first frequency corresponding portion in which first and second waveforms are combined in a first ratio, and a second frequency corresponding portion in which the first and second waveforms are combined in a second ratio different from the first ratio. This allows printing of a test pattern in which a drive frequency is changed in a pseudo manner while a recording medium is transported at a constant speed. Thus, the head is inspected for abnormalities occurring in response to the drive frequency.