Display and Infrared Light Emitters with Reflective Upper Electrodes
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Solution Overview
Problem
Existing display apparatuses face challenges in efficiently delivering infrared light to the eye through an eyepiece optical system due to reduced light intensity and the need for a wider angular distribution, which affects line-of-sight detection accuracy.
Innovation Solution
The design includes a light emitting apparatus with a display region and an infrared light emitting region positioned non-overlapping on a substrate, where the infrared light emitting elements have a higher reflectance upper electrode to enhance light extraction efficiency, allowing efficient delivery of infrared light to the eye.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If infrared light is emitted through an eyepiece optical system for line-of-sight detection, then the infrared light can reach the user's eye, but the light intensity remarkably decreases due to lens transmittance deterioration
Solution Approach 1:
The patent applies local quality by differentiating the upper electrode properties between display light emitting elements and infrared light emitting elements. Specifically, the infrared light emitting element's upper electrode is designed with high reflectance at infrared wavelengths, while display light emitting elements use electrodes optimized for visible light emission. This localized optimization ensures that infrared light is efficiently extracted and directed toward the user's eye without being lost in the optical system.
Solution Approach 2:
The patent changes the optical parameters of the upper electrode by controlling its reflectance characteristics at infrared wavelengths. The infrared light emitting element's upper electrode is designed to have a reflectance of 30% or more at infrared wavelengths, which is a significant parameter change from conventional electrodes. This parameter change enables efficient infrared light extraction and compensation for losses in the eyepiece optical system.
2Volume of moving object
If the display apparatus uses a small eyepiece optical system, then the device size is reduced, but lens transmittance deteriorates and light intensity decreases
Solution Approach 1:
The patent applies local quality by optimizing the infrared light emitting element's upper electrode specifically for infrared wavelength reflectance. This localized optimization ensures that even in a compact device with a small eyepiece optical system, the infrared light intensity is sufficient for line-of-sight detection by enhancing light extraction at the source.
Solution Approach 2:
The patent changes the optical parameters of the upper electrode to achieve high reflectance (30% or more) at infrared wavelengths. This parameter change compensates for the reduced light transmission in small eyepiece optical systems, maintaining adequate infrared light intensity for eye tracking functionality in compact devices.
3Productivity
If the upper electrode of the infrared light emitting element has high reflectance at infrared wavelength, then light extraction efficiency is improved, but visible light transmission may be affected
Solution Approach 1:
The patent applies local quality by designing the upper electrode of the infrared light emitting element with wavelength-selective properties. The electrode material and structure are optimized to provide high reflectance specifically at infrared wavelengths while maintaining transparency or appropriate optical properties for visible light. This allows the display function to operate normally while enabling efficient infrared light extraction for line-of-sight detection.
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 improves light extraction efficiency, ensuring effective line-of-sight detection even through eyepiece optical systems by enhancing infrared light delivery to the cornea.
Implementation Method 1
A reflectance of the upper electrode of the infrared light emitting element at an infrared wavelength is higher than a reflectance of the upper electrode of the display light emitting element at the infrared wavelength
Data Source
AI summary
A light emitting apparatus includes a display region and an infrared light emitting region on a substrate. A plurality of display light emitting elements is disposed in the display region. A plurality of infrared light emitting elements is disposed in the infrared light emitting region. In a plan view of the substrate, the display region and the infrared light emitting region are in a positional relationship not overlapping each other. Each of the display light emitting element and the infrared light emitting element is made by laminating a lower electrode, a functional layer including a light emitting layer, and an upper electrode in this order from the substrate side. A reflectance of the upper electrode of the infrared light emitting element at an infrared wavelength is higher than a reflectance of the upper electrode of the display light emitting element at the infrared wavelength.