Optical Engine Beam Splitting for Touch Projection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional projection apparatuses with touch screen functions have low space efficiency and volume due to independent transmission paths for image and infrared beams, leading to non-uniform infrared illumination and increased complexity with multiple CCDs, and complicate light valve processing, reducing image brightness and touch screen identification efficiency.
Innovation Solution
An optical engine with a beam splitting element, including a first dichroic unit and optical path turning unit, and a light valve, which separates and combines visible and invisible beams to share closer transmission directions, allowing simultaneous emission and uniform brightness distribution on the screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If independent transmission paths are used for image beam and infrared beam, then the functions can be independently implemented, but the space efficiency is low and the volume of the projection apparatus increases
Solution Approach 1:
The patent merges the transmission paths of the image beam and infrared beam into a shared optical path. The light valve processes both visible light (for image beam) and infrared light sequentially, allowing both functions to share the same transmission path through the light valve, thereby reducing the overall volume of the projection apparatus while maintaining independent functional capabilities.
2Reliability
If independent transmission paths are used for image beam and infrared beam, then the functions can be independently implemented, but the device complexity increases
Solution Approach 1:
The patent combines multiple functions into a single light valve that processes both visible and infrared light. By using one light valve to handle both image beam and infrared beam processing sequentially, the patent reduces the number of separate components needed, thereby simplifying the overall device structure and reducing complexity.
3Area of stationary object
If infrared beam is shaped by beam shaping element to irradiate every area on the screen, then the coverage is improved, but the light intensity distribution becomes non-uniform
Solution Approach 1:
The patent uses periodic action by sequentially processing different regions of the screen over time. The light valve processes infrared light for different areas in a sequential manner, allowing uniform illumination across the entire screen while maintaining complete coverage. This temporal sequencing resolves the conflict between coverage and uniformity.
4Measurement precision
If multiple CCDs with different gains are used to detect different areas on the screen, then the detection accuracy is improved, but the device complexity and cost increase
Solution Approach 1:
The patent applies homogeneity by ensuring uniform infrared light intensity distribution across the entire screen. This uniform illumination allows a single CCD to detect objects accurately across all areas without requiring multiple CCDs with different gains. The homogeneous light distribution eliminates the need for complex multi-CCD systems.
5Reliability
If light valve processes infrared light during a period time, then the infrared beam can be properly handled, but the time for processing visible light is reduced
Solution Approach 1:
The patent implements periodic action by sequentially allocating time periods for processing infrared light and visible light in the light valve. During certain time periods, the light valve processes infrared light for touch detection, while during other time periods, it processes visible light for image projection. This time-division multiplexing ensures both functions are properly handled while managing the limited processing time.
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 optical engine achieves higher average light intensities for both visible and invisible beams, improving image brightness and touch screen identification while simplifying control algorithms and reducing costs by using a single CCD with uniform illumination across the screen.
Implementation Method 1
The first dichroic unit is obliquely disposed relatively to the visible beam and the invisible beam... One of the visible beam and the invisible beam from the illumination system is capable of being reflected by the first dichroic unit, the other one of the visible beam and the invisible beam from the illumination system is capable of passing through the first dichroic unit
Implementation Method 2
the other one of the visible beam and the invisible beam from the illumination system is capable of passing through the first dichroic unit, being reflected by the optical path turning unit, and passing through the first dichroic unit in sequence
Implementation Method 3
The second dichroic unit is disposed in the transmission paths of the visible beam and the invisible beam from the beam splitting element, wherein the visible beam is capable of passing through the second dichroic unit, and the invisible beam is capable of being reflected by the second dichroic unit
Implementation Method 4
The light valve is disposed in the transmission path of the visible beam from the second dichroic unit and is capable of converting the visible beam into an image beam
Data Source
AI summary
An optical engine including an illumination system, a beam splitting element, a second dichroic unit, and a light valve is provided. The illumination system provides a visible beam and an invisible beam. The beam splitting element is disposed in transmission paths of the visible and invisible beams. After the visible and invisible beams leave the beam splitting element, the optical axes of the visible and invisible beams are separated from each other. The second dichroic unit is disposed in the transmission paths of the visible and invisible beams from the beam splitting element. The visible beam passes through the second dichroic unit, and the invisible beam is reflected by the second dichroic unit. The light valve is disposed in the transmission path of the visible beam from the second dichroic unit and converts the visible beam into an image beam. The image beam passes through the second dichroic unit.