Inkjet Head Driving Circuit Merging Inspection and Printing Signals
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Solution Overview
Problem
Existing liquid-ejecting recording apparatuses face inefficiencies in inspecting the state of the ejecting section, particularly due to increased inspection time and reduced accuracy when performing inspections outside the inkjet head, and the need for larger circuit sizes and additional bypass circuits.
Innovation Solution
The implementation of a driving circuit within the inkjet head that generates both printing and inspection driving signals, allowing for exclusive output to the ejecting section, reducing inspection time and improving accuracy by using separate power supply paths with distinct bypass capacitors and transistor circuit groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If inspection is performed outside the inkjet head, then the ejecting section can be inspected, but inspection time increases and accuracy decreases
Solution Approach 1:
The inspection circuit is merged with the inkjet head by integrating the driving circuit inside the head. The driving circuit includes a printing driving signal generation section and an inspection driving signal generation section that share common components (transistors, power supply paths, bypass capacitors) with the ejecting section, enabling inspection to be performed directly at the source without external equipment, thereby reducing inspection time and improving accuracy.
2Adaptability or versatility
If external inspection circuits are used, then inspection functionality is added, but device size increases
Solution Approach 1:
The inspection functionality is merged into the existing inkjet head structure. The driving circuit shares power supply paths (first and second power supply paths with first and second bypass capacitors respectively) and transistor circuit groups with the ejecting section, eliminating the need for separate external inspection circuits and reducing overall device size.
Solution Approach 2:
The driving circuit is designed to perform multiple functions: it can generate printing driving signals for normal operation and inspection driving signals for diagnostic purposes. The same transistor circuit groups and power supply paths serve both printing and inspection functions, making the system multi-functional without requiring additional dedicated components.
3Measurement precision
If separate power supply paths with bypass capacitors are used for inspection, then inspection accuracy is improved, but circuit size increases
Solution Approach 1:
The power supply system is designed with universal paths that serve dual purposes. The first power supply path with its bypass capacitor serves both the printing operation and the inspection operation. Similarly, the second power supply path with its bypass capacitor is shared between printing and inspection functions. This multi-functional design provides the necessary electrical isolation and filtering for accurate inspection measurements without requiring completely separate power supply systems.
Data Source
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AI summary
An embodiment of the present disclosure is a driving circuit (49) for ejecting liquid from a plurality of nozzles (Hn) in an ejecting section (41, 42) in a liquid ejecting head (4). The driving circuit includes a first signal generation section (491) that generates a printing driving signal (Sd1) for ejecting the liquid from the nozzles, a second signal generation section (492) that generates an inspection driving signal (Sd2) for inspecting a state of the ejecting section, and a control section (490a, 490b) that controls the first signal generation section and the second signal generation section so as to exclusively output one of the printing driving signal and the inspection driving signal to the ejecting section.