Inkjet Nozzle Inspection Using Neighboring Ejection Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printing apparatuses face challenges in maintaining detection accuracy of ink droplet ejection states due to unstable flight of droplets at low ejection velocities, leading to erroneous determination of non-ejection and inability to measure ejection velocity accurately.
Innovation Solution
A printing apparatus with a droplet detection sensor that stabilizes ink droplet flight by controlling ejection from neighboring nozzles in conjunction with the target nozzle, using a light beam to detect ejection states and adjusting nozzle control to ensure stable detection conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ink droplets are ejected at low velocity to achieve precise image formation, then image quality is improved, but detection accuracy of ejection state deteriorates due to unstable flight
Solution Approach 1:
The patent introduces a detection region positioned at an optimized distance from the print head where droplets with low ejection velocity can still be reliably detected. This detection region acts as an intermediary zone that accommodates the unstable flight of low-velocity droplets, allowing accurate detection without requiring high ejection velocities.
Solution Approach 2:
The patent changes the detection parameter by measuring the time period from ejection signal output to droplet arrival at the detection region, rather than relying on direct optical detection. This time-based measurement approach is more suitable for low-velocity droplets and maintains detection accuracy even when flight is unstable.
2Reliability
If optical detector is used to detect ink droplet ejection state, then non-ejection can be determined, but ejection velocity measurement becomes inaccurate due to unstable flight at low velocities
Solution Approach 1:
The patent dynamically adjusts the detection approach by using time-period measurement that adapts to varying droplet velocities. Instead of assuming stable flight, the system measures the actual time taken for droplets to reach the detection region, making the velocity measurement accurate even when flight is unstable.
Solution Approach 2:
The patent replaces direct optical measurement of droplet position with a time-based measurement system. By measuring the time interval between ejection signal and droplet arrival at the detection region, the system substitutes mechanical/optical position measurement with temporal measurement, which is more accurate for low-velocity unstable flight.
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
Enhances detection accuracy of ink droplet ejection states by stabilizing flight distances and velocities, preventing erroneous determinations even at low ejection velocities.
Implementation Method 1
a pair of a light emitting element and a light receiving element are used and an ink droplet is ejected so as to pass through a light beam emitted from the light-emitting element and reach the light receiving element
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An embodiment of the present invention is a printing apparatus (100) including: a print head (201) including a plurality of nozzles configured to eject droplets onto a print medium (203); a control means (301,305) arranged to control driving of each of the plurality of nozzles to eject the droplets; and an inspection means (201,205) configured to configured to inspect whether or not each of the plurality of nozzles is able to eject the droplets normally by driving the print head by the control unit, wherein in a case where the inspection means inspects one target nozzle among the plurality of nozzles, the control means drives the target nozzle and one or more neighboring nozzles arranged near the target nozzle.