X-ray Phase-Contrast Grating Orientation for Displacement Tolerance
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Solution Overview
Problem
Conventional X-ray phase-contrast imaging apparatuses using Talbot interferometers suffer from deteriorated image quality due to positional displacements of gratings caused by grating holders, which affect the relative position between phase and absorption gratings, leading to changes in the shape of the step curve and subsequent image quality.
Innovation Solution
The X-ray phase-contrast imaging apparatus is configured with gratings arranged such that their extending direction aligns with the maximum positional displacement due to the grating holder, minimizing changes in the relative position between the self-image of the phase grating and the absorption grating, and incorporating a grating position adjustment mechanism to move gratings orthogonally to the displacement direction, thereby stabilizing the step curve and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If gratings are held by grating holders during imaging, then the gratings can be positioned and adjusted, but positional displacement of gratings occurs in a plane orthogonal to the optical axis direction, causing deterioration of image quality
Solution Approach 1:
The patent rotates the gratings by 90 degrees around the optical axis, changing the orientation of the grating components from the vertical direction to the horizontal direction. This dimensional change ensures that positional displacement occurs along the extending direction of the grating components rather than orthogonal to it, thereby preventing image quality deterioration while maintaining the grating holder's positioning capability
Solution Approach 2:
The patent introduces asymmetric orientation of the grating components relative to the grating holder's displacement direction. By aligning the extending direction of the grating components with the maximum displacement direction, the system creates an asymmetric configuration that is inherently more tolerant to positional displacement, resolving the contradiction between ease of operation and manufacturing precision
2Manufacturing precision
If the extending direction of grating components is oriented perpendicular to the maximum positional displacement direction, then positional displacement affects the relative position between gratings, but orienting it parallel suppresses such effects
Solution Approach 1:
The patent employs a 90-degree rotation of the grating orientation around the optical axis, transforming the grating component direction from vertical to horizontal. This dimensional transformation aligns the grating extending direction with the maximum displacement direction, achieving high manufacturing precision without requiring complex adjustment mechanisms
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 effectively suppresses the deterioration of image quality by maintaining the positional relationship between gratings, even with grating holder-induced positional displacements, ensuring stable image generation.
Implementation Method 1
a first grating (3) for changing a phase of the X-ray irradiated from the X-ray source (1) to thereby generate Talbot interference
Implementation Method 2
for changing a phase of the X-ray irradiated from the X-ray source (1) to thereby generate Talbot interference
Implementation Method 3
a second grating (4) for shielding a part of the X-ray forming an image generated by shielding a part of the X-ray irradiated from the X-ray source (1)
Data Source
AI summary
This X-ray phase-contrast imaging apparatus is equipped with a plurality of gratings and grating holders for holding the plurality of gratings. The plurality of gratings is arranged such that the extending direction of grating components of the plurality of gratings is oriented in a direction in which the positional displacement due to the grating holder becomes maximum in a plane orthogonal to an optical axis of the X-ray.