Optical Unit Pre-positioning for Image Reader Wake-up Time Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image reading apparatuses with power saving modes face challenges in quickly switching back to standby mode for document size detection, leading to delayed user operability due to the time required for homing and AGC processes, and potential document cover closure before detection can occur.
Innovation Solution
The image reading apparatus positions the optical unit at the document size detecting position before switching to sleep mode, allowing immediate detection upon returning to standby mode, and utilizes downward and upward movement detection to manage power state changes, ensuring swift document size detection and high user operability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the apparatus switches to power saving mode by stopping power supply, then energy consumption is reduced, but the time required to return to standby mode increases due to homing and AGC processes
Solution Approach 1:
The optical unit is positioned at the document size detecting position before the apparatus enters power saving mode. This preliminary positioning action ensures that when the apparatus wakes up, the optical unit is already at the correct location for document size detection, eliminating the need for homing and AGC processes after power restoration, thus reducing wake-up time while maintaining energy savings
2Reliability
If homing and AGC processes are performed after power restoration, then the system ensures proper initialization, but document size detection is delayed
Solution Approach 1:
The optical unit is pre-positioned at the document size detecting position before power saving mode activation. Additionally, the document size detecting unit is configured to immediately detect document size using image signals from the image sensor as soon as power is restored, bypassing the traditional homing and AGC sequences. This approach maintains initialization reliability by ensuring the optical unit is already in the correct position while significantly improving document processing speed
3Measurement precision
If the apparatus uses traditional document size detection methods with sensors, then detection accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the document size detection function from dedicated physical sensors and implements it using the existing image sensor that captures document images for scanning. The document size detecting unit processes image signals from the image sensor to determine document boundaries and dimensions. This approach maintains detection accuracy by utilizing the high-resolution imaging capability already present in the system while eliminating the need for additional specialized sensors, thereby reducing device complexity and cost
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
Enables immediate document size detection and maintains high user operability even with power saving modes by positioning the optical unit for detection before mode changes, reducing the need for post-switch homing and AGC processes and allowing quicker document handling.
Implementation Method 1
an image sensor configured to convert image light of a document into an image signal
Data Source
AI summary
An image reading apparatus is provided that includes an image sensor configured to convert image light of a document into an image signal, an optical unit configured to project the image light of the document on the image sensor, a drive unit configured to drive the optical unit in a sub scanning direction, a document size detecting unit configured to detect a size of the document using the image signal, an image signal processing unit configured to digitally convert the image signal of the image sensor into image data, a power circuit configured to output an operating voltage in standby mode and stop the outputting of the operating voltage in sleep mode, and a power saving control unit configured to position the optical unit to a document size detecting position before switching the power circuit from the standby mode to the sleep mode.