AR Optical Device Reflective Units for Wide Field of View
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Solution Overview
Problem
Conventional augmented reality optical devices are cumbersome, costly, and have limited field of view and depth of field, requiring complex configurations and separate operations to adjust focal length, while existing solutions with small reflective units suffer from narrow field of view and high manufacturing costs.
Innovation Solution
An optical device using a reflective structure with multiple reflective units smaller than the pupil, disposed inside the optical means, which reflects image light toward the user's pupil to provide a wide field of view and deep depth of field without disconnection, while maintaining high optical efficiency and reducing device thickness and volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional optical systems using prisms are used, then augmented reality function is achieved, but device weight and volume become considerable
Solution Approach 1:
The patent divides the single large reflective surface into multiple small reflective units (e.g., 9 reflective units arranged in 3x3 grid). Each reflective unit is smaller than the pupil diameter, enabling the system to achieve AR function while significantly reducing the size and weight of the optical device compared to conventional prism-based systems.
Solution Approach 2:
The multiple small reflective units are nested within a compact optical structure, with each reflective unit positioned at different depths along the optical path. This nesting arrangement allows the system to maintain AR functionality while minimizing the overall device volume and weight.
2Reliability
If conventional optical systems with large reflective surfaces are used, then augmented reality function is achieved, but manufacturing cost becomes high
Solution Approach 1:
By segmenting the reflective surface into multiple small units, the patent enables the use of simpler, cheaper manufacturing processes for each unit. The small reflective units can be manufactured using standard techniques and then assembled, reducing overall manufacturing cost compared to producing a single large precision optical component.
Solution Approach 2:
The patent employs inexpensive reflective materials (such as aluminum or silver coatings on small substrates) for the reflective units rather than expensive precision optical glass. This substitution of cheap materials for expensive ones significantly reduces manufacturing cost while maintaining the necessary optical functionality.
3Reliability
If a single small reflective unit smaller than pupil is used, then depth of field is deepened, but field of view becomes narrow
Solution Approach 1:
The patent overcomes the narrow field of view limitation by using multiple small reflective units instead of a single small unit. The array of reflective units (e.g., 9 units) collectively covers a wider angular range, expanding the field of view while each individual unit remains smaller than the pupil to maintain deep depth of field.
Solution Approach 2:
The patent combines the optical effects of multiple small reflective units to achieve a cumulative field of view that is wider than what a single unit could provide. By merging the contributions of all reflective units in the array, the system achieves both deep depth of field and wide field of view simultaneously.
4Area of stationary object
If multiple reflective units are arranged to widen field of view, then field of view increases, but device thickness increases
Solution Approach 1:
The patent arranges multiple reflective units in a three-dimensional configuration along the optical path (depth dimension) rather than simply spreading them out in a plane. By utilizing the depth dimension, the system achieves a wide field of view without proportionally increasing device thickness, as the reflective units are positioned at different depths rather than only laterally separated.
Solution Approach 2:
The reflective units are nested within a compact optical structure where smaller components are positioned within the volume defined by larger components. This nesting arrangement allows multiple reflective units to be accommodated in a thin profile, achieving wide field of view without significant increase in device thickness.
5Loss of energy
If reflective units are positioned to maximize light transfer, then optical efficiency increases, but field of view may be limited
Solution Approach 1:
The patent optimizes the position, size, and orientation of each individual reflective unit to maximize light transfer efficiency for its specific location in the array. Each reflective unit is locally optimized for its particular angular position, ensuring high optical efficiency while the collective arrangement of all units provides a wide field of view.
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 provides a wider field of view and eye box with deepened depth of field, achieving a pinhole effect and high optical efficiency without additional light loss, while maintaining a thin and lightweight design.
Implementation Method 1
a reflective unit disposed inside the optical means; wherein the image light corresponding to the image for augmented reality output from the image output unit is reflected at least once from the inner surface of the optical means and transferred to the reflective unit; and wherein the reflective unit reflects the transferred image light toward the pupil of an eye of a user
Implementation Method 2
a small reflective unit is used... A kind of pinhole effect is provided by deepening the depth of field, so that a clear virtual image may always be provided regardless of whether the user changes the focal length
Data Source
AI summary
An optical device for augmented reality includes an optical means for transmitting at least part of visible light therethrough, a reflective unit disposed inside the optical means, and an image output unit configured to output image light corresponding to an image for augmented reality toward the inner surface of the optical means. The image light corresponding to the image for augmented reality output from the image output unit is reflected at least once from the inner surface of the optical means and transferred to the reflective unit. The reflective unit reflects the transferred image light toward the pupil of an eye of a user, thereby providing the image for augmented reality to the user.