Image Reading Device Sensor Distance Adjustment
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Solution Overview
Problem
Image reading devices with divided light receiving sensors face issues with image overlap and missing areas due to improper distance between the document and sensors, leading to suboptimal read image data, as existing solutions fail to adjust the document-sensor distance effectively.
Innovation Solution
The implementation of a system that adjusts the distance between the document and light receiving sensors by displacing pre-reading and post-reading conveying rollers, using a control unit to determine the necessary displacement based on detected image overlap or missing areas, ensuring proper image acquisition by maintaining the correct sensor-document distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single light receiving sensor is divided into multiple light receiving sensors arranged in the main scanning direction, then the reading unit can be realized with lower cost and smaller size, but the distance between the document and the light receiving sensors becomes more sensitive causing image overlap areas and image missing areas
Solution Approach 1:
The patent makes the document conveying rollers dynamically adjustable in position along the sub-scanning direction. The rollers can be displaced to change the document's position relative to the divided light receiving sensors, allowing the system to adapt to distance variations and eliminate image overlap or missing areas while maintaining the simplified divided sensor structure
Solution Approach 2:
The patent changes the physical parameter of roller position to control the document-sensor distance. By adjusting the position of the document conveying rollers, the system modifies the distance parameter between the document and the light receiving sensors, thereby optimizing image quality without changing the sensor division structure
2Productivity
If the document is conveyed at a position displaced from the reference conveyance plane, then the reading process continues, but image overlap areas or image missing areas occur due to improper distance
Solution Approach 1:
The patent incorporates an overlap amount/missing amount detection unit that detects image quality issues and provides feedback to the control unit. The control unit then adjusts the document conveying roller positions based on this feedback, creating a closed-loop control system that maintains reliable image data quality while ensuring continuous reading operation
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 solution effectively suppresses image overlap and missing areas, enabling high-quality read image data by accurately adjusting the sensor-document distance, thereby improving image reading performance in image forming apparatuses.
Implementation Method 1
a plurality of light receiving sensors 1 to N arranged in a main scanning direction... received by the respective light receiving sensors 1 to N
Implementation Method 2
lenses 261 to 26N... a reflected light 270 from the document is reduced in the lenses 261 to 26N and received by the respective light receiving sensors 1 to N
Data Source
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AI summary
An image overlap amount and a missing amount in an image overlap area and a missing area, which are generated when a document is conveyed at a position apart from a reference conveyance plane (250) as being away from or closer to light receiving sensors (1 to N) are detected in more than one parts, in a main scanning direction, from image data of a document read by the light receiving sensor. Based on the detected overlap amount and missing amount, an adjustment amount for adjusting the distance between the light receiving sensor and the document for at least one part in the main scanning direction of the document is determined, and the distance between the document and the light receiving sensor is adjusted by displacing at least one of the document conveying rollers (201, 202) and the light receiving sensors according to the adjustment amount.