Rotating-Mirror Camera Bellows Pascal Spiral Alignment
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Solution Overview
Problem
The conventional camera bellows of rotating-mirror framing cameras suffer from non-uniform framing frequency due to inconsistent scanning of the exit-pupil diaphragm array during uniform rotation of the rotating mirror, leading to image blur, reduced resolution, and time-based identification errors.
Innovation Solution
The camera bellows design aligns the centers of the exit-pupil diaphragm array with a cylindrical surface aligned with a Pascal spiral line, ensuring uniform scanning of the exit-pupil diaphragm array during rotation, and positions the image recording surface and relay lens principal points on corresponding cylindrical surfaces to maintain optical conjugacy and reduce imaging errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the exit-pupil diaphragm array is arranged on a conventional curved surface, then the device complexity is reduced, but the framing frequency becomes non-uniform during uniform rotation of the rotating mirror
Solution Approach 1:
The patent applies curvature by arranging the exit-pupil diaphragm array on a curved surface that follows a Pascal spiral line trajectory. This curved arrangement ensures that during uniform rotation of the rotating mirror, the scanning speed across the diaphragm array remains uniform, thereby achieving uniform framing frequency. The curved surface geometry is specifically designed to match the spiral trajectory required for constant angular velocity scanning.
2Manufacturing precision
If the relay lens array is arranged on a fungible-circle curved surface, then the device complexity is reduced, but image resolution deteriorates due to defocusing errors
Solution Approach 1:
The relay lens array is arranged on a curved surface that follows a Pascal spiral line trajectory, matching the true imaging trajectory. This curved arrangement ensures that each relay lens remains properly focused on its corresponding image point throughout the rotation, eliminating defocusing errors and maintaining high image resolution. The curvature of the lens array surface is specifically designed to match the spiral imaging path.
3Measurement precision
If conventional fungible-circle design is used for curved surfaces, then ease of manufacture is improved, but time-based identification accuracy deteriorates at large angles
Solution Approach 1:
The curved surfaces for both the exit-pupil diaphragm array and relay lens array are designed following Pascal spiral line trajectories. This spiral curvature ensures that the angular position and timing information remain accurately correlated throughout the full rotation range, maintaining high time-based identification accuracy even at large angles. The spiral geometry naturally preserves the temporal-spatial relationship required for precise timing measurements.
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 design ensures uniform framing frequency, improves image resolution by minimizing defocusing errors, and reduces time-based identification errors, especially at large angles, by maintaining the direction of the incident light beam and aligning optical axes with reflective points.
Implementation Method 1
A mirror image I2′ is formed upon mirroring the secondary image I2 by the rotating mirror 4
Data Source
AI summary
A new camera bellows of a rotating-mirror framing camera, without principle errors such as defocusing error of imaging points, non-uniform photographic frequency and each axial chief ray of exit-pupil and the corresponding relay lens being different with a corresponding reflective optical axis, is provided. This kind of camera bellows is carried out through centers of the exit-pupil diaphragms being disposed on a cylindrical surface aligned with a first Pascal spiral line, and principal points of the relay lenses of the relay lens array and the image recording surface being disposed on cylindrical surfaces aligned with second and third Pascal spiral lines respectively. The bellows is mainly composed of a box, and an aperture diaphragm, a field lens, a rotating mirror, a relay lens array, an exit-pupil diaphragm array and a record image surface.