Optical Scanning Apparatus Control Circuit Board Fixing
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Solution Overview
Problem
The existing optical scanning apparatuses for image forming devices face issues with the warping of control circuit boards due to reflow soldering, leading to shifts in the position of beam detect sensors, which affect the timing of the horizontal synchronization signal for controlling the image writing start position.
Innovation Solution
The control circuit board is fixed to the optical box using a fixing unit arranged between the connection points for the light source and exterior connections, with at least one fixing screw positioned closer to the detector than the light source, ensuring proper alignment and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the control circuit board is fixed onto the optical box with screws at a position away from the BD sensor, then the fixing is simple and stable, but the BD sensor position shifts due to board warping affecting timing accuracy
Solution Approach 1:
The patent applies preliminary action by positioning the fixing screw between the light source connection and exterior connection points on the control circuit board, closer to the detector than the light source. This predetermined fixing location compensates for board warping effects before the BD sensor position becomes critical, ensuring timing accuracy is maintained despite thermal expansion or contraction during operation.
2Strength
If the control circuit board undergoes reflow soldering, then electronic components are securely attached, but the board warps causing BD sensor position shift
Solution Approach 1:
The patent applies local quality by making the fixing screw location specific and differentiated from conventional approaches. The fixing point is strategically positioned between the light source connection and exterior connection points, closer to the detector, creating a localized stabilization zone that compensates for warping effects in the critical BD sensor region without affecting overall board assembly.
Solution Approach 2:
The patent applies preliminary anti-action by positioning the fixing screw to counteract the warping force that would otherwise shift the BD sensor. The fixing location is chosen to preemptively oppose the direction and magnitude of expected warping deformation, thereby maintaining BD sensor positioning precision despite the thermal stresses of reflow soldering.
3Ease of manufacture
If the BD sensor position is shifted due to board warping, then the fixing structure is simple, but the timing of horizontal synchronization signal is advanced or delayed
Solution Approach 1:
The patent applies preliminary action by pre-positioning the fixing screw at a specific location on the control circuit board that anticipates and compensates for warping-induced timing shifts. This predetermined fixing arrangement ensures the BD sensor maintains accurate positioning for horizontal synchronization signal timing without requiring complex post-assembly adjustments.
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 configuration reliably and accurately positions the detector for generating the horizontal synchronization signal, maintaining a stable image writing start position and preventing timing shifts caused by board warping.
Implementation Method 1
The BD sensor is configured to receive the laser light beam to generate a horizontal synchronization signal
Data Source
AI summary
An optical scanning apparatus, including: a detector configured to detect a writing start position of a light beam emitted from a light source and reflected by a rotary polygon mirror; and a control circuit board electrically connected to the light source, wherein the detector is fixed to the control circuit board, the control circuit board includes a first connection portion at which the light source is connected to the control circuit board and a second connection portion through which the control circuit board and an exterior are electrically connected, the control circuit board is fixed to an optical box by a fixing unit, and the fixing unit is arranged, between the first connection portion and the second connection portion, on a second straight line orthogonal to a first straight line connecting the light source and the detector, so as to be closer to the detector than to the light source.