Projection Prism Folds Illumination Paths for Compact Optics
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Solution Overview
Problem
Conventional projection apparatuses require significant internal space to ensure the illumination beam has enough path length, making them unsuitable for the trend of smaller volume projection devices.
Innovation Solution
A projection apparatus design where the illumination beam goes to and fro between a reflective element and a prism, reducing the space needed for transmission, and using fewer optical elements by condensing the beam twice, thereby reducing the overall volume and manufacturing cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional optical path design with multiple lenses and prisms is used, then the illumination beam can be properly condensed and directed, but the internal space required becomes large
Solution Approach 1:
The patent combines multiple optical functions into a single integrated optical element. The prism simultaneously performs beam condensation, reflection, and directional control that would traditionally require separate lenses and mirrors. This merging of functions directly reduces the number of discrete optical components and the overall device volume.
Solution Approach 2:
The patent utilizes the third dimension (depth) by implementing a folded optical path within the prism structure. The illumination beam undergoes multiple internal reflections and refractions within the prism's three-dimensional geometry, effectively condensing the optical path length into a compact spatial footprint without compromising optical performance.
2Reliability
If the path length of the illumination beam is increased to ensure proper condensation, then the optical performance is improved, but the distance between optical elements cannot be shortened
Solution Approach 1:
The patent nests the optical path within the prism structure itself. The illumination beam traverses a condensed path through multiple internal surfaces of the single prism element, achieving the necessary optical path length equivalent to traversing through multiple separate components. This nesting of the optical path within a compact geometric structure maintains optical performance while minimizing the external dimensions.
Solution Approach 2:
The patent employs curved refractive surfaces within the prism to redirect and condense the illumination beam. The curved interfaces enable the beam to follow a folded trajectory within the prism, effectively increasing the optical path length without proportionally increasing the physical distance between entry and exit points, thus maintaining compactness.
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 design achieves a smaller volume and lower manufacturing costs by minimizing the space required for the illumination beam transmission and reducing the number of optical elements, addressing the challenge of compactness in projection apparatuses.
Implementation Method 1
the illumination beam is reflected by the second surface and emitted from the third surface
Implementation Method 2
After the illumination beam is reflected by the reflective element, the illumination beam passes through the third surface
Implementation Method 3
The light valve is disposed adjacent to the fifth surface, and is located on the transmission path of the illumination beam reflected by the reflective element. The illumination beam is converted by the light valve into an image beam
Implementation Method 4
The projection lens is disposed adjacent to the sixth surface, and is located on a transmission path of the image beam
Data Source
AI summary
A projection apparatus includes a prism set, a light source, a reflective element, a light valve and a projection lens. The prism set includes a first prism having a first surface, a second surface and a third surface, and a second prism having a fourth surface opposite to the second surface, a fifth surface and a sixth surface. The reflective element, light valve and projection lens are respectively disposed adjacent to the third, fifth and sixth surfaces. The light source emits an illumination beam to the first surface. The non polarized illumination beam is reflected by the second surface and the reflective element. The non polarized illumination beam passes through the third, second, fourth and fifth surfaces in sequence. The non polarized illumination beam is converted by the light valve into an image beam which is reflected by the fourth surface and passes through the sixth surface to the projection lens in sequence.