Optical Device Beam Splitter Photodiode Offset Parasitic Light
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Solution Overview
Problem
Existing projection devices face challenges in accurately controlling light projection due to parasitic light interference and optical losses, which compromise image quality and size constraints for mobile applications.
Innovation Solution
An optical device comprising a beam splitter that splits light into primary and secondary beams, where the photodiode is offset to reduce parasitic light and accurately detect characteristics of the secondary beam, allowing for precise control of the primary beam and improved image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If optical sensors are positioned within the projection device to measure light before projection, then the device size is reduced, but parasitic light from the sensors compromises image quality
Solution Approach 1:
The harmful function of the optical sensor is extracted by separating its detection function from the main optical path. The sensor detects light characteristics through a beam splitter without being positioned in the direct projection path, thus removing the source of parasitic light interference while maintaining the compact device structure.
Solution Approach 2:
A beam splitter is introduced as an intermediary element between the light source and the optical sensor. This mediator allows the sensor to detect light characteristics indirectly without being positioned in the direct projection path, eliminating parasitic light while maintaining device compactness.
2Measurement precision
If optical sensors are positioned to directly measure projected light, then measurement accuracy is improved, but the sensor interferes with the projected light and compromises image quality
Solution Approach 1:
The optical path is segmented into two separate paths using a beam splitter: one path for projection and one for detection. This segmentation allows the optical sensor to measure light characteristics accurately without interfering with the projected light, as the sensor operates in a separate detection path.
Solution Approach 2:
The beam splitter serves as an intermediary that divides the light into two paths, enabling simultaneous projection and detection without interference. The sensor measures light characteristics through this intermediary mechanism rather than directly in the projection path.
3Object-affected harmful factors
If optical components are positioned to minimize parasitic light projection, then image quality is improved, but device complexity increases
Solution Approach 1:
The beam splitter performs multiple functions simultaneously: it directs the projection beam, enables optical sensor detection, and minimizes parasitic light projection. This multi-functionality reduces the need for additional specialized components and simplifies the overall optical design.
Solution Approach 2:
The beam splitter acts as a versatile intermediary that handles multiple optical paths and functions in a single component, reducing device complexity compared to using separate components for each function.
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 solution enables accurate control of light projection characteristics, reduces parasitic light interference, and enhances image quality while minimizing the size of the projection device, making it suitable for mobile applications.
Implementation Method 1
a beam splitter, which is arranged to receive the combined light beam and to split the combined light beam into a primary light beam and a secondary light beam
Implementation Method 2
the beam splitter comprises a first surface through which the primary light beam is emitted from the beam splitter and a second surface through which the secondary light beam is emitted from the beam splitter
Implementation Method 3
a mirror component which comprises a mirror, wherein the mirror component is arranged such that the mirror can reflect the primary light beam which is emitted through, or reflected by, the first surface of the beam splitter and wherein the mirror can oscillate about at least one oscillation axis to scan the primary light beam
Implementation Method 4
a photodiode which is configured to receive the secondary light beam and to detect one or more characteristics of the secondary light beam
Data Source
AI summary
According to the present invention, there is provided an optical device comprising, a plurality of light sources each operable to provide a light beam; at least one beam combiner which is operable to combine the light beams from the plurality of light sources, to provide a combined light beam; a beam splitter, which is arranged to receive the combined light beam and to split the combined light beam into a primary light beam and a secondary light beam, wherein one or more characteristics of the secondary light beam are indicative of one or more characteristics of the primary light beam, wherein the beam splitter comprises a first surface through which the primary light beam is emitted from the beam splitter and a second surface through which the secondary light beam is emitted from the beam splitter; a mirror component which comprises a mirror, wherein the mirror component is arranged such that the mirror can reflect the primary light beam which is emitted through the first surface of the beam splitter and wherein the mirror can oscillate about at least one oscillation axis to scan the primary light beam; wherein the optical device further comprises a photodiode which is configured to receive the secondary light beam and to detect one or more characteristics of the secondary light beam, wherein the photodiode is configured to be offset from being parallel to at least one of the first surface or second surface of the a beam splitter, to reduce the amount of parasitic light which is directed to the mirror. There is further provided a corresponding method of projecting an image.