Curved Scanning Projector Screen for Homogeneous Beam Diameter
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Solution Overview
Problem
Scanning projectors using laser light suffer from inhomogeneous beam diameters along the scanning direction, leading to uneven brightness and clarity issues between neighboring pixels due to varying distances from the rotation axis, which affects image quality.
Innovation Solution
A scanning projector screen is designed with a curved surface in the scanning direction, ensuring both ends of the screen are closer to the rotation axis, maintaining equal distances and thus homogeneous beam diameters, which enhances image clarity by minimizing beam diameter variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a flat screen is used in a scanning projector, then the device structure is simple, but the beam diameter becomes inhomogeneous along the scanning direction causing brightness unevenness
Solution Approach 1:
The patent applies curvature to the screen surface by making it arc-shaped along the scanning direction. This curved surface ensures that the distance from the rotation axis to each point on the screen remains constant, thereby maintaining homogeneous beam diameter and uniform brightness across the entire screen area.
2Area of stationary object
If the screen is positioned far from the rotation axis to increase scanning area, then the coverage area increases, but the beam diameter inhomogeneity becomes more pronounced
Solution Approach 1:
By curving the screen surface into an arc shape, the patent enables the screen to be positioned at an optimal distance from the rotation axis while maintaining constant distance to all screen points. This resolves the conflict between maximizing screen area and maintaining beam diameter uniformity.
3Ease of manufacture
If a rectangular screen is used, then the manufacturing is easy, but the beam scanning distance varies causing inhomogeneous beam diameter
Solution Approach 1:
The patent transforms the screen from a flat rectangular shape to an arc-shaped configuration. While this increases manufacturing complexity compared to a flat screen, it ensures that the scanning distance remains constant across the entire screen, thereby maintaining homogeneous beam diameter and consistent image quality.
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 curved screen surface ensures consistent beam diameters along the scanning direction, reducing brightness inconsistencies and improving image clarity by maintaining equal distances from the rotation axis, resulting in a clearer and more uniform image projection.
Implementation Method 1
an irradiation direction of the synthetic light is controlled by a high-speed two-dimensional scanning element 430 and scanned in two-dimension. The high-speed two-dimensional scanning element 430 is an element which performs optical scanning by using a movable mirror 430a
Implementation Method 2
The respective emitted light pass through collective lenses (412R, 412G and 412B) arranged on optical axes near the light sources (410R, 410G and 410B), thereby providing convergent light
Implementation Method 3
the green convergent light is combined (i.e., multiplexed) with the red convergent light by a dichroic mirror 414G, and further the blue convergent light is combined (i.e., multiplexed) with them by a dichroic mirror 414B into one synthetic light
Implementation Method 4
a scanning projector screen having a screen surface that is curved in at least one direction. By arranging such scanning projector screen such that both ends of the curved screen surface are arranged closer to the rotation axis on a rotation axis of a movable mirror
Data Source
AI summary
Provided is a scanning projector screen which can suppress inhomogeneity of a beam diameter. The scanning projector screen has a screen surface that is curved in at least one direction.