Image Reading Apparatus Accelerated Conveyance Control
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Solution Overview
Problem
Conventional image reading apparatuses face challenges in stabilizing the reading operation during acceleration and deceleration segments due to prolonged storage of electric charge, leading to destabilization and potential interruptions in the reading process.
Innovation Solution
An image reading apparatus with a control unit that operates in two modes: one for inputting command signals at a predetermined time interval during acceleration and deceleration segments, and another synchronized with displacement signals during constant velocity segments, ensuring appropriate timing for the reading operation and minimizing charge accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reading operation is executed by conveying the reading unit or original at constant velocity, then the reading operation is stable, but the reading velocity is limited and the apparatus size increases
Solution Approach 1:
The patent applies dynamics by transitioning from constant velocity conveyance to accelerated conveyance. The reading unit conveys the original at accelerated velocity while maintaining stable reading operation, thereby increasing reading velocity without sacrificing stability. This resolves the contradiction by making the system dynamic rather than static.
Solution Approach 2:
The patent changes the velocity parameter from constant to accelerated. By controlling the conveyance velocity to increase over time, the system achieves both higher reading velocity and stable reading operation, resolving the contradiction between speed and stability.
2Measurement precision
If the shift pulse is generated in accordance with motor rotation, then the reading operation is synchronized with conveyance, but the output time interval increases during acceleration and deceleration, prolonging noise electric charge storage time
Solution Approach 1:
The patent applies preliminary action by resetting the photoelectric conversion element in advance before the shift pulse is generated. This preliminary reset prevents noise electric charge accumulation during acceleration and deceleration phases, maintaining operation stability while preserving reading synchronization.
Solution Approach 2:
The patent applies preliminary anti-action by counteracting the potential harm of noise electric charge accumulation through proactive resetting. The reset operation precedes the problematic period, preventing the accumulation of unstable charges that would otherwise occur during variable velocity conveyance.
3Productivity
If the photoelectric conversion element accumulates electric charge for extended periods during interruption, then the element may not be appropriately reset, but continuous reading operation requires uninterrupted charge accumulation
Solution Approach 1:
The patent applies periodic action by implementing regular reset operations at predetermined intervals regardless of interruption status. This periodic resetting ensures the photoelectric conversion element is properly initialized before each reading operation, maintaining reliability while enabling continuous productivity through systematic charge management.
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 stabilizes the reading operation by reducing charge accumulation during acceleration and deceleration segments and allows for precise timing during constant velocity segments, enhancing the overall reading performance and reducing the risk of interruptions.
Implementation Method 1
The electric charge to be transmitted is generated by the photoelectric effect during a time period from the previous shift pulse to the current shift pulse
Data Source
AI summary
An image reading apparatus includes: a reading unit which reads an original as an object to be read in a main scanning direction every time a command signal is inputted; a command unit which inputs the command signal to the reading unit; a conveying unit which conveys at least one of the original and the reading unit so as to change a relative position between the reading unit and the original in a sub scanning direction; a signal output unit which outputs a displacement signal every time the relative position is changed by a predetermined amount; and a control unit which controls the command unit. The command unit which operates in a first mode to output the command signal to the reading unit at a predetermined time interval and in a second mode to output the command signal to the reading unit at a timing synchronized with the displacement signal.