Light Scanning Unit with Folded Optical Paths for Compact Printer Design
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Solution Overview
Problem
In electrophotographic image forming apparatuses, the need to reduce the size of color laser printers requires light scanning units with optical components suitable for narrow intervals between photoreceptors, which existing technologies have not adequately addressed.
Innovation Solution
A light scanning unit with a deflector and an imaging optical system that includes multiple reflecting members and scanning lenses, where light paths are designed to intersect and change direction multiple times to efficiently focus light beams onto photoreceptors spaced closely together, minimizing the size of the apparatus and optimizing the arrangement of optical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If photoreceptors are arranged with narrow intervals to reduce apparatus size, then the size of the image forming apparatus is reduced, but the optical path design becomes more complex and difficult to implement
Solution Approach 1:
The patent applies nesting by arranging optical components in a compact, nested configuration where light paths are folded back on themselves multiple times within a limited space. The imaging optical system nests multiple reflecting members and scanning lenses in sequence, with light paths intersecting and reusing spatial volumes, thereby achieving narrow photoreceptor intervals while maintaining functional optical paths.
Solution Approach 2:
The patent employs dimensional transformation by changing the light path from a simple linear arrangement to a multi-dimensional folded configuration. Light beams undergo multiple reflections and direction changes, transitioning between different spatial dimensions and planes, which allows the optical system to fit within a compact volume while maintaining adequate optical path lengths for proper imaging.
2Volume of moving object
If photoreceptors are arranged with narrow intervals, then the apparatus size is reduced, but the arrangement and alignment of optical components becomes more difficult
Solution Approach 1:
The patent divides the imaging optical system into segmented functional units, with different groups of reflecting members and scanning lenses assigned to specific light paths. This segmentation allows for modular assembly and alignment, where each segment can be independently positioned and adjusted, facilitating manufacturing despite the compact overall configuration.
Solution Approach 2:
The patent merges multiple light paths and optical components into a shared spatial configuration. Different light paths intersect and share common optical components or adjacent positioning, reducing the total volume required while maintaining distinct functional paths. This merging approach simplifies the overall structure compared to providing separate dedicated spaces for each optical path.
3Volume of moving object
If light paths are folded multiple times to achieve compact size, then the apparatus is miniaturized, but the number of optical components increases
Solution Approach 1:
The patent applies universality by designing optical components that serve multiple functions within the compact system. Reflecting members and scanning lenses are positioned to handle multiple light paths simultaneously, with single components performing imaging, directing, and focusing functions for different beams. This multi-functionality reduces the total component count despite the folded light path configuration.
Solution Approach 2:
The patent employs dynamic light path management where the optical system adapts to different scanning positions and angles through the coordinated action of multiple reflecting members. The light paths are dynamically redirected based on the scanning requirements, allowing the same physical components to serve varying optical functions throughout the scanning cycle, thereby reducing the need for additional static components.
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 allows for a more compact light scanning unit and reduced intervals between photoreceptors, enabling the miniaturization of the image forming apparatus while maintaining effective light beam focusing and image formation.
Implementation Method 1
a first group of reflecting members configured to change a first light path at least twice, the first light path being a path of one of the light beams directed to one of the surfaces disposed relatively far from the deflector; and a second group of reflecting members configured to change a second light path at least twice
Implementation Method 2
an imaging optical system configured to respectively focus the light beams deflected by the deflector onto a plurality of surfaces to be scanned
Data Source
AI summary
A light scanning unit and an electrophotographic image forming apparatus employing the same. The light scanning unit includes an imaging optical system including, when a path of one of the light beams directed to one of the surfaces disposed relatively far from the deflector is referred to as a first light path and when a path of one of the light beams directed to one of the surfaces disposed relatively close to the deflector is referred to as a second light path, light paths in which both of a section of the second light path before a first change of the second light path and a section of the second light path after the first change of the second light path intersect a section of the first light path after a second change of the first light path.