Image Sensor Unit Slit for Color Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In erecting equal-magnification imaging systems, color mixture occurs on the sensor surface due to the dispersion of light from spectral devices, leading to reduced resolution.
Innovation Solution
An image sensor unit with a color separation optical system that includes a slit or mirror on the intermediate imaging plane to restrict the visual field in the sub-scanning direction, preventing overlapping light intensities and inhibiting color mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a spectral device such as a diffraction grating is provided in front of the sensor surface to separate light into RGB colors, then color separation is achieved, but color mixture occurs on the sensor surface due to light dispersion, leading to reduced resolution
Solution Approach 1:
The patent divides the imaging process into two stages: first forming a complete image using the erecting equal-magnification lens array, then introducing a slit to segment the light paths from different object points. This segmentation prevents color mixture by ensuring that light from each object point passes through a restricted angular range, while still achieving color separation through the spectral device. The slit effectively separates the light paths spatially before they reach the sensor surface.
Solution Approach 2:
The patent introduces an intermediary element (the slit) placed at the intermediate imaging plane between the object and the sensor. This intermediary restricts the visual field in the sub-scanning direction and controls the angular range of light reaching the sensor, thereby preventing color mixture while allowing the spectral device to perform color separation. The intermediary mediates between the conflicting requirements of color separation and spatial resolution.
2Manufacturing precision
If the visual field is restricted using a slit or mirror on the intermediate imaging plane, then color mixture is prevented, but the device complexity increases
Solution Approach 1:
The patent merges the visual field restriction function with the existing intermediate imaging plane of the erecting equal-magnification system. Rather than adding a completely separate component, the slit or mirror is integrated into the existing optical path at a plane that already exists in the system architecture. This merging approach minimizes additional complexity while achieving the desired visual field restriction.
Solution Approach 2:
The intermediate imaging plane serves multiple functions: it is both a necessary component of the erecting equal-magnification imaging system and the optimal location for placing the visual field restriction element (slit or mirror). By making this plane multi-functional, the patent avoids adding redundant components and reduces overall device complexity while still achieving color mixture prevention.
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 effectively prevents color mixture on the sensor surface, improving color separation and resolution by restricting the visual field with a slit or mirror, which can be implemented without obstructing the light source or document surface.
Implementation Method 1
a spectral device such as a diffraction grating is provided in front of the sensor surface to separate the light into the RGB colors
Implementation Method 2
each of the rod lenses being embodied by a columnar graded index glass rod having a higher refraction index at the center
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An image sensor unit 10 includes: a linear light source 14 that illuminates a document G with a light; a first erecting equal-magnification lens array 16 and a second erecting equal-magnification lens array 18 arranged in the stated order away from the document so as to receive a light reflected from the document G and form an erecting equal-magnification image; a slit 17 provided on an intermediate imaging plane between the first erecting equal-magnification lens array 16 and the second erecting equal-magnification lens array 18; a diffraction grating that disperses a light output from the second erecting equal-magnification lens array 18; and a linear image sensor 15 that receives a light dispersed by the diffraction grating 19.