Projection Lens with Concave Mirror for Compact Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current projector designs require a long projection distance for large images, leading to increased lens volume and cost due to the need for multiple lenses to correct distortion and chromatic aberration, compromising optical quality.
Innovation Solution
A projection lens system with a concave reflector that allows light rays to pass through three times, utilizing a sequence of lenses and a concave mirror, with specific diameter relationships and movement capabilities to achieve three times imaging with good optical quality, low distortion, and low chromatic aberration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple lenses are used to correct distortion and chromatic aberration, then optical quality is improved, but lens volume and cost increase
Solution Approach 1:
The patent combines multiple lens functions into a reduced number of lens elements. Specifically, the projection lens uses only 6 lenses (L1-L6) to achieve both distortion correction and chromatic aberration correction, whereas conventional designs require more lenses. The patent achieves this by optimizing the arrangement and parameters of each lens element, allowing them to perform multiple correction functions simultaneously, thereby reducing overall lens volume while maintaining optical quality.
Solution Approach 2:
The patent employs specific parameter ranges for lens elements to achieve optimal performance with fewer components. By carefully controlling parameters such as focal lengths, distances between lenses, and curvature radii (as specified in the claims), the system achieves effective distortion and chromatic aberration correction with a compact 6-lens configuration, rather than requiring additional lens elements with conventional parameter ranges.
2Reliability
If multiple lenses are used to correct distortion and chromatic aberration, then optical quality is improved, but cost increases
Solution Approach 1:
The patent merges multiple correction functions into fewer lens elements, directly reducing the bill of materials and assembly costs. By achieving distortion and chromatic aberration correction with only 6 lenses instead of more, the patent reduces manufacturing complexity and component costs while maintaining the required optical quality standards.
Solution Approach 2:
Each lens element in the patent is designed to perform multiple functions simultaneously. For example, certain lenses contribute to both focusing and aberration correction, making the system more cost-effective by eliminating the need for separate dedicated correction lenses that would increase overall system cost.
3Length of moving object
If a wide-angle lens with reflector is used to reduce projection distance, then projection distance is reduced, but lens distortion and chromatic aberration increase
Solution Approach 1:
The patent introduces a reflective element (concave mirror or reflective plate) to fold the optical path, effectively reducing the physical projection distance while maintaining the optical path length needed for proper imaging. This dimensional change in the optical layout allows short projection distance without sacrificing optical quality, as the light still traverses the necessary optical path through the 6 lenses for proper aberration correction.
Solution Approach 2:
The reflective element acts as an intermediary that redirects light without introducing significant aberrations. By using a carefully designed reflector (concave mirror or reflective plate positioned at specific angles), the system achieves compact projection distance reduction while the subsequent lens elements correct any minor distortions introduced by the reflection, maintaining overall optical 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 solution enables efficient three-time imaging with a compact and cost-effective projector design, maintaining high optical quality and reducing the need for excessive lenses, thus addressing the challenges of volume and cost while improving imaging performance.
Implementation Method 1
a concave reflector, which may allow a light ray emitted from a light valve to pass through an optical axis three times and generate three times of imaging
Implementation Method 2
The projection lens includes 9 to 30 lenses with refractive power
Data Source
AI summary
A projection lens includes a first lens, a second lens, an aperture stop, a third lens, a fourth lens, a fifth lens, a sixth, and a concave mirror sequentially arranged from a minified side to a magnified side. An outer diameter of the second lens is less than an outer diameter of the first lens. An outer diameter of the fifth lens is greater than that of the fourth lens. An outer diameter of the sixth lens is less than that of the fifth lens. The first lens, the second lens, the aperture stop, and the third lens are fixed relative to the concave mirror and the fourth lens is capable of moving along an optical axis relative to the concave mirror when the projection lens is in focusing. The projection lens includes 9 to 30 lenses with refractive power. A projector using said projection lens is also provided.