Roll Paper Residual Quantity Detection via Reverse Rotation Control
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Solution Overview
Problem
Existing recording-medium-residual-quantity detecting devices in printers and liquid ejecting apparatuses face inaccuracies due to slippage between the paper transporting roller and the roll paper, leading to errors in calculating the residual quantity of roll paper, especially when normal rotation is used, which increases friction and the likelihood of slippage.
Innovation Solution
A device that includes a first rotation-quantity detecting unit for the roll, a second rotation-quantity detecting unit for the transportation roller, and a controlling unit that applies rotational power to both, allowing for winding control mode to prevent slippage by rotating the roll and transportation roller in the direction of winding, thereby calculating the residual quantity more accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If normal rotation is used to transport the roll paper, then the transportation roller can move the roll paper in the conventional direction, but friction increases and slippage occurs, leading to inaccurate residual quantity calculation
Solution Approach 1:
The patent applies reverse rotation to the transportation roller instead of normal rotation. By rotating the transportation roller in the opposite direction to conventional operations, the friction between the roller and roll paper is reduced, preventing slippage and enabling accurate measurement of the residual quantity through rotation quantity detection.
2Measurement precision
If a dedicated detection roller is provided to prevent slippage, then measurement accuracy improves, but device complexity and cost increase
Solution Approach 1:
The patent makes the existing transportation roller serve dual functions: it continues to transport the roll paper while also serving as the detection roller for measuring residual quantity. By applying reverse rotation to the transportation roller, the system eliminates the need for a separate dedicated detection roller, thereby reducing device complexity and cost while maintaining measurement accuracy.
3Measurement precision
If reverse rotation is used to prevent slippage, then measurement accuracy improves, but the transportation direction may be affected
Solution Approach 1:
The patent employs dynamic control of the transportation roller's rotation direction. During normal transportation operations, the roller rotates in the conventional direction to move the roll paper. During residual quantity measurement, the system switches to reverse rotation to prevent slippage and enable accurate detection. This dynamic adjustment of rotation direction based on operational mode allows the system to maintain both efficient transportation and precise measurement capabilities.
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
This approach prevents slippage and enhances the accuracy of residual quantity calculation by reducing friction between the transportation roller and the roll paper, allowing for precise determination of the remaining roll paper length, even when reverse rotation is employed, thus avoiding the errors associated with normal rotation methods.
Implementation Method 1
a transportation roller that transports the recording medium by rotating in contact with the recording medium that is unwound from the roll
Data Source
AI summary
A recording-medium-residual-quantity detecting device includes a first rotation-quantity detecting unit that detects a rotation quantity of a roll in which a recording medium is wound. A second rotation-quantity detecting unit detects a rotation quantity of a transportation roller that transports the recording medium by rotating in contact with the recording medium that is unwound from the roll. A controlling unit has a winding control mode in which driving units of the device are controlled so that rotational powers to wind the recording medium into the roll without slack between the roll and the transportation roller are applied to the roll and the transportation roller. The residual quantity of the recording medium is calculated on the basis of a rotation quantity θr of the roll and a rotation quantity θs of the transportation roller that are respectively detected by the rotation-quantity detecting units when the winding control mode is executed.