Polygon Mirror Velocity Adjustment in Image Forming Apparatus
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Solution Overview
Problem
Existing image forming apparatuses face challenges in reducing the first print out time while preventing recording material from being made dirty, as they require time for adjusting the rotation velocity of the polygon mirror and risk exposing the photosensitive member to unnecessary toner, leading to extended print times and potential contamination.
Innovation Solution
The apparatus includes first and second image forming devices with a photosensitive member, a light source, and a developing member, where the adjustment device adjusts the polygon mirror's velocity based on a detected light beam, allowing the developing member to move to the developing position before the adjustment is complete, and the light source is controlled to prevent exposure during adjustment, ensuring toner does not adhere to the photosensitive member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the polygon mirror rotation velocity is adjusted before image forming processing, then the image forming velocity is optimized, but the first print out time is extended
Solution Approach 1:
The developing member is moved to the developing position in advance before the polygon mirror rotation velocity adjustment is completed, allowing the system to prepare for image forming while the velocity calibration is still in progress, thereby reducing the overall first print out time
Solution Approach 2:
The system dynamically adjusts the timing of developing member positioning relative to the velocity adjustment progress, allowing flexible coordination between mechanical positioning and velocity calibration to minimize idle time
2Measurement precision
If the laser beam is emitted continuously during scanner motor startup for velocity detection, then the rotation velocity is accurately detected, but the photosensitive member is exposed to unnecessary toner
Solution Approach 1:
The laser beam emission for velocity detection is extracted from the continuous emission process and performed only during the forcible emission period when the developing member is separated from the photosensitive member, isolating the detection function from the harmful toner exposure effect
Solution Approach 2:
The developing member separation state acts as an intermediary condition that enables safe laser beam emission for velocity detection, creating a temporal window where detection can occur without causing toner adhesion to the photosensitive member
3Object-affected harmful factors
If a low power bias is applied to the developer to prevent toner adhesion, then the photosensitive member is protected from contamination, but a time is required for switching to normal bias
Solution Approach 1:
The developing member is moved to the separated position in advance before the laser beam emission for velocity detection, preemptively preventing toner adhesion issues before they can occur, thereby eliminating the need for bias switching and its associated time delay
4Object-affected harmful factors
If the developer is separated from the photosensitive member to prevent toner adhesion, then the photosensitive member is protected, but the first print out time is extended
Solution Approach 1:
The developing member is moved to the separated position in advance before the velocity adjustment period begins, preemptively preventing toner adhesion issues before they can occur, thereby eliminating the need for bias switching and its associated time delay
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 reduces the first print out time by allowing the developing member to start moving before the adjustment is finished and prevents toner from making the recording material dirty, thereby improving the efficiency and cleanliness of the image forming process.
Implementation Method 1
a polygon mirror that reflects each of the light beams emitted from the light sources
Implementation Method 2
forming an image on a recording material... a photosensitive member, a light source that emits a light beam
Data Source
AI summary
The detector that detects a light beam emitted from a light source of a second image forming device and reflected by a polygon mirror, and an adjustment device that performs adjustment processing of adjusting the velocity of the polygon mirror based on an output of the detector are provided. Before a first image forming device performs the image forming processing, the adjustment device performs the adjustment processing while causing the light source of the second image forming device to emit the light beam during a time period including at least a time period in which a photosensitive member of the second image forming device is emitted with the light beam. Before the adjustment processing is finished, the first image forming device starts to move a developing member to a developing position.