Roll Paper Near-End Detection Using a Top-Surface Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing printers face issues with detecting the near-end state of roll paper due to obstruction by roll paper guides, which hinder accurate detection of remaining paper when the roll paper is narrow.
Innovation Solution
A printing apparatus with a roll paper compartment and a projecting/retracting portion that adjusts based on the roll paper diameter, using detection sections to accurately determine the near-end state by projecting or retracting portions that interact with the roll paper surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a roll paper guide is mounted between the roll paper and side wall of paper storage, then the roll paper is guided properly, but the space between the roll paper and sensor is obstructed, hindering detection of near-end state
Solution Approach 1:
The detection method transitions from side-wall detection to top-surface detection. The sensor is positioned above the roll paper to detect the top surface, which remains accessible even when roll paper guides are mounted on the side walls. This dimensional change in detection approach eliminates the obstruction problem while maintaining guidance functionality.
2Measurement precision
If the sensor is positioned close to the roll paper for accurate detection, then detection precision improves, but the detection is hindered when roll paper guide is mounted due to narrow roll paper
Solution Approach 1:
The top-surface detection method provides a universal solution that works for roll papers of various widths. By detecting the top surface rather than the side surface, the system maintains consistent detection capability whether the roll paper is narrow or wide, eliminating the need to adjust sensor positioning based on roll paper dimensions.
3Device complexity
If a light reflection type sensor is provided on the side wall of paper storage, then the structure is simple, but the detection is obstructed by roll paper guide and roll paper itself
Solution Approach 1:
The sensor positioning moves from the side wall dimension to the top surface dimension. This spatial repositioning allows the simple light reflection detection method to work reliably by accessing the top surface of the roll paper, which is not blocked by side-mounted guides or the roll paper body itself.
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
Ensures accurate detection of the near-end state of roll paper by preventing obstruction and minimizing erroneous detections, allowing for efficient paper usage and easy replacement.
Implementation Method 1
a light emitter that emits light toward a side end surface of the roll paper, and a light receiver that receives light reflected by the side end surface of the roll paper
Data Source
AI summary
A printing apparatus includes a roll paper compartment 15 having a first placement surface 27 on which an outer peripheral surface Ra of a roll paper R around which a recording paper P is wound is placed and accommodating the roll paper R, a thermal head 67 performing printing on the recording paper P pulled out from the roll paper R accommodated in the roll paper compartment 15, a first projecting/retracting portion 77 provided to be configured to project from or retract into the first placement surface 27, pressed by the roll paper R of which the outer peripheral surface Ra is placed on the first placement surface 27 and retracting into the first placement surface 27 when a diameter of the roll paper R is larger than a predetermined diameter, and released from the pressure by the roll paper R and protruding from the first placement surface 27 when the diameter of the roll paper R is smaller than the predetermined diameter, and a detection section detecting projection and retraction of the first projecting/retracting portion 77.