Movable Image Sensor Height Adjustment for Inkjet Nozzle Inspection
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Solution Overview
Problem
Ink-jet printers with line heads experience image quality deterioration due to ink ejection failures, nozzle clogs, and uneven ink distribution, leading to soiling of image sensors and unnecessary recovery operations.
Innovation Solution
An image recording apparatus with a movable image sensor that maintains a higher distance from the recording medium than the inkjet head during normal operation, allowing for precise detection of ink ejection failures and reduced soiling, and adjusts height for inspecting mode to improve ink attachment accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the image sensor is positioned closer to the recording medium for better image pickup, then image detection capability is improved, but the lower surface of the image sensor becomes soiled with ink mist and adhering undried ink
Solution Approach 1:
The patent introduces a vertical height dimension between the image sensor and recording medium, positioning the image sensor above the ejection surface level. This spatial repositioning in the vertical dimension allows the image sensor to detect recorded images without being exposed to ink mist and splashes that occur at the ejection surface level, thereby solving the contradiction between detection capability and soiling prevention
Solution Approach 2:
The patent introduces a light-entering surface as an intermediary interface between the image sensor and the recording medium. This light-entering surface allows optical signals to pass through while physically protecting the image sensor from direct contact with ink mist and splashes, enabling image detection without soiling
2Manufacturing precision
If the recording head is positioned closer to the recording medium for better ink attachment accuracy, then ink ejection precision is improved, but the image sensor becomes more exposed to ink mist and soiling
Solution Approach 1:
The patent separates the vertical positioning of the recording head and image sensor, allowing the recording head to be positioned closer to the recording medium for accurate ink ejection while the image sensor is positioned higher to avoid ink mist exposure. This dimensional separation resolves the contradiction between ejection precision and soiling prevention
3Device complexity
If the image sensor is positioned below the ejection surface level for structural integration, then device compactness is improved, but reliability of image data is lowered due to soiling
Solution Approach 1:
The patent repositions the image sensor in the vertical dimension above the ejection surface level, creating physical separation from the ink ejection zone. This spatial arrangement maintains structural integration while preventing ink mist and splashes from soiling the image sensor, thereby ensuring image data reliability
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 image sensor reliability by minimizing soiling and improving ink ejection accuracy, allowing for precise detection of nozzle failures and maintaining image quality.
Implementation Method 1
an image-forming optical system which guides, to the image-pickup element, a light entered through the light-entering surface and which is for forming, on the image-pickup element, an optical image of an object
Data Source
AI summary
An image recording apparatus including: a medium-convey belt; a recording head; an image sensor being movable together with the recording head and including an image-pickup element, an image-forming optical system, and a light-entering surface which is more distant from the medium-convey belt than an ejection surface of the recording head, and a raising and lowering mechanism which positions the recording head, wherein the recording head is positioned, when in an inspecting mode in which the recording head is inspected, at a first height at which an optical image of an image recorded on the medium-convey belt or recorded on the recording medium on the medium-convey belt is formed on the image-pickup element by the image-forming optical system, while positioned, when in a normal recording mode, at a second height at which the ejection surface is more distant from the medium-convey belt than at the first height, and wherein the image sensor picks up the image when the recording head is positioned at the first height.