Projection Lens Third Group Constant Distance Beam Coverage
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Solution Overview
Problem
In projection apparatuses, the lens group closest to the image source often fails to completely cover the image beam during zooming, leading to energy absorption by external elements and overheating.
Innovation Solution
A projection lens configuration with specific refractive powers and lens group arrangements, including a first, second, and third lens group, maintains a constant distance between the light valve and the twelfth lens, ensuring the third lens group completely covers the image beam across varying focal lengths, preventing energy absorption by external elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the distance between the image source and the lens group closest to the image source is changed during zooming, then the projection lens can adjust focal length to project clear images, but the lens group cannot completely cover the image beam causing energy absorption and overheating of external elements
Solution Approach 1:
The patent applies dynamics by making the distance between the light valve (image source) and the lens group closest to it variable during zooming operations. The lens system dynamically adjusts the position of the light valve relative to the lens group to maintain complete coverage of the image beam across different focal lengths, preventing energy loss and overheating of external elements.
2Length of stationary object
If the distance between the image source and the lens group closest to the image source is enlarged, then the lens group has more space to cover the image beam, but the element outside the lens group absorbs energy causing overheating
Solution Approach 1:
The patent applies preliminary action by pre-positioning the light valve at an optimized distance from the lens group before zooming begins. This preliminary positioning ensures that during subsequent zooming operations, the lens group maintains adequate coverage of the image beam, preventing energy absorption by external elements before the problem can occur.
3Device complexity
If a conventional projection lens structure is used, then the device complexity is lower, but the lens group cannot completely cover the image beam during zooming
Solution Approach 1:
The patent applies segmentation by dividing the projection lens into multiple lens groups with specific refractive powers (positive and negative lenses arranged in sequences). This segmentation allows each lens group to perform specific optical functions, enabling complete coverage of the image beam during zooming while maintaining manageable device complexity through modular design.
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 ensures complete coverage of the image beam during zooming, preventing overheating by maintaining a constant distance between the light valve and the twelfth lens, thus addressing the issue of energy absorption by external elements in conventional projection apparatuses.
Implementation Method 1
The projection lens includes a first lens group, a second lens group, and a third lens group. The first lens group includes a first lens, a second lens, and a third lens arranged sequentially from the screen side to the image side. Refractive powers of the first lens, the second lens, and the third lens are sequentially negative, negative, and positive.
Data Source
AI summary
A projection lens and a projection apparatus are provided. The projection lens has a screen side and an image side. The projection lens includes a first lens group, a second lens group, and a third lens group. The first lens group disposed between the screen side and the image side includes a first, a second, and a third lenses arranged sequentially from the screen side to the image side. The second lens group disposed between the first lens group and the image side includes a fourth, a fifth, a sixth, a seventh, an eighth, a ninth, and a tenth lenses arranged sequentially from the screen side to the image side. The third lens group disposed between the second lens group and the image side includes an eleventh and a twelfth lenses, and a distance between the twelfth lens and the light valve is a constant.