LCOS Display and IR Sensor Integration on Silicon Die
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Solution Overview
Problem
Current head-mounted displays (HMDs) face issues with size and cost due to visible defects in images caused by the arrangement of LCOS pixels and IR sensor pixels, which affect resolution and uniformity.
Innovation Solution
An integrated image sensor and display device is designed with display pixels and image sensor pixels arranged in rows and columns on a single substrate, where image sensor pixels are positioned between adjacent rows and columns of display pixels, with a larger area for display pixels to minimize defects and improve resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If LCOS pixels and IR sensor pixels are arranged in alternating columns or checkerboard configuration on a single silicon die, then device size is minimized and manufacturing cost is reduced, but visible defects appear in the projected image and image quality deteriorates
Solution Approach 1:
The device is segmented into distinct functional regions: a display region containing LCOS pixels for light modulation and projection, and a sensor region containing IR sensor pixels for gesture detection. This spatial segmentation eliminates the interleaved arrangement that causes visible defects, allowing each region to optimize its pixel arrangement without interfering with the other's performance.
Solution Approach 2:
The IR sensor pixels are extracted from the display region and placed in a separate sensor region. This extraction removes the harmful interaction between display and sensor pixels, eliminating the visible defects caused by alternating column or checkerboard configurations while maintaining the benefits of integration on a single silicon die.
2Adaptability or versatility
If LCOS pixels and IR sensor pixels are arranged in alternating columns or checkerboard configuration, then both functions are integrated on single die, but resolution and uniformity of image captured by IR sensor are limited
Solution Approach 1:
The device is segmented into distinct functional regions: a display region containing LCOS pixels for light modulation and projection, and a sensor region containing IR sensor pixels for gesture detection. This spatial segmentation eliminates the interleaved arrangement that causes visible defects, allowing each region to optimize its pixel arrangement without interfering with the other's performance.
Solution Approach 2:
Different regions of the silicon die are assigned different local qualities optimized for their specific functions. The display region uses LCOS pixel structures optimized for light modulation, while the sensor region uses IR sensor pixel structures optimized for infrared detection. This local optimization enables both high display quality and high sensor resolution within the integrated device.
3Device complexity
If LCOS pixels and IR sensor pixels share common optical path, then device complexity is reduced, but visible defects and non-uniformities appear in both display and sensor functions
Solution Approach 1:
The device is segmented into distinct functional regions: a display region containing LCOS pixels for light modulation and projection, and a sensor region containing IR sensor pixels for gesture detection. This spatial segmentation eliminates the interleaved arrangement that causes visible defects, allowing each region to optimize its pixel arrangement without interfering with the other's performance.
Solution Approach 2:
A beam splitter or dichroic mirror serves as an intermediary optical element that separates the visible light path for display from the infrared light path for sensing. This intermediary allows both functions to share the integrated silicon die while maintaining distinct optical paths, preventing the visible defects and non-uniformities that arise from shared optical paths in interleaved configurations.
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 enables the display of high-quality images and accurate detection of gestures while reducing visible defects, resulting in improved image capture and display uniformity.
Implementation Method 1
Current HMD's utilize a liquid crystal on silicon (LCOS) display, a light source, and optics to display images
Implementation Method 2
This light reflects off the eye and onto an IR sensor, which detects, in real time, whether the eye is open or closed, and, if open, in which direction the pupil is pointing
Data Source
AI summary
A novel head mounted display includes a display/image sensor. In a particular embodiment the display/image sensor is formed on a single silicon die, which includes display pixels and light sensor pixels. The display pixels and light sensor pixels are each arranged in rows and columns, and the arrays of light sensor pixels and display pixels are interlaced. The center of each light sensor pixel is located between adjacent rows and adjacent columns of display pixels.