Optical Scanning Device With Low-Resolution Light Source Unit
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Solution Overview
Problem
Existing optical scanning devices face limitations in forming high-resolution electrostatic latent images at high speeds due to the physical constraints and economic inefficiencies of using multiple light source units and beam splitters, which restrict the ability to form monochrome images faster than full-color images and result in a large device size.
Innovation Solution
An optical scanning device with a compact structure that includes high-resolution light source units positioned on one side of a polygon mirror, a low-resolution light source unit positioned to not interfere with these units, and a deflection system that allows the low-resolution beams to scan the photoreceptor without a beam splitter, enabling faster monochrome image formation while maintaining device compactness and economic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple high-resolution light source units are used to form high-resolution electrostatic latent images, then image resolution is improved, but device size and complexity increase
Solution Approach 1:
The patent divides the light source units into two distinct groups: high-resolution light source units (first light source units) for forming high-resolution electrostatic latent images, and low-resolution light source units (second light source units) for forming low-resolution electrostatic latent images. This segmentation allows each group to be optimized for its specific function, reducing the need for multiple high-resolution units and thereby decreasing device complexity and size.
Solution Approach 2:
The patent applies local quality by positioning the low-resolution light source units at a location that does not interfere with the high-resolution light source units and the first optical system. Specifically, the low-resolution units are positioned to irradiate the photoreceptor after the high-resolution beams have been deflected, allowing each region of the device to have specialized functionality optimized for its purpose.
2Adaptability or versatility
If beam splitters are used to direct low-resolution beams, then monochrome image formation is enabled, but device cost increases
Solution Approach 1:
The patent extracts the low-resolution image formation function from the high-resolution optical path by providing separate low-resolution light source units that directly irradiate the photoreceptor without requiring beam splitters or other expensive optical components. This extraction eliminates the need for costly beam splitting mechanisms while maintaining the capability to form monochrome images.
Solution Approach 2:
The patent makes the imaging system universal by enabling it to perform both high-resolution full-color image formation and low-resolution monochrome image formation using the same photoreceptor and basic optical components. The low-resolution light source units can operate independently or in conjunction with the high-resolution units, providing multi-functionality without requiring additional specialized components like beam splitters.
3Productivity
If polygon mirror rotation speed is increased to form high-resolution images faster, then productivity is improved, but mechanical limits are exceeded
Solution Approach 1:
The patent applies dynamics by providing different resolution capabilities for different operational modes: high-resolution light source units for when maximum image quality is required, and low-resolution light source units for when faster formation speed is needed. This dynamic switching between resolution modes allows the system to adapt to different productivity requirements without exceeding the mechanical rotation limits of the polygon mirror.
Solution Approach 2:
The patent changes the resolution parameter by switching between high-resolution and low-resolution light source units depending on the desired output. When forming monochrome images or when speed is prioritized, the low-resolution units are used, which require fewer scan lines and thus reduce the total rotation requirement of the polygon mirror, enabling faster image formation within mechanical limits.
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
The solution enables the formation of high-resolution images at speeds comparable to full-color images and allows for faster monochrome image formation without increasing device size, improving operational efficiency and reducing costs by eliminating the need for expensive beam splitters.
Implementation Method 1
Each of the photoreceptor drums is rotated when irradiated by the corresponding laser beam. The laser beams scan the respective photoreceptor drums along the main scanning direction
Implementation Method 2
a first optical system causes the laser beams generated by the respective semiconductor laser elements to irradiate a rotating polygon mirror. Next, the rotating polygon mirror causes the four laser beams to proceed along a main scanning direction
Data Source
AI summary
An optical scanning device comprises: photoreceptors corresponding one-to-one to solid colors; high-resolution light sources each emitting a set of beams irradiating the corresponding photoreceptor with a predetermined distance therebetween along a sub-scanning direction; a deflection unit; a first optical system directing the sets of beams from the high-resolution light sources to the deflection unit; a low-resolution light source emitting a set of beams irradiating a predetermined photoreceptor with a distance therebetween larger than the predetermined distance along the sub-scanning direction; and a second optical system directing all of the sets of beams to the corresponding photoreceptor. The low-resolution light source and first optical system are positioned so as not to physically interfere with the high-resolution light sources and first optical system, and so as to allow the set of beams from the low-resolution light source to scan an image forming area on the predetermined photoreceptor along a main-scanning direction.