OLED Display Viewing Angle Control via Asymmetric Black Matrix
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Solution Overview
Problem
Organic light emitting display apparatuses have a wide viewing angle, making it difficult to use them safely in public places without others viewing the displayed images.
Innovation Solution
The apparatus includes a substrate with organic light emitting pixels, a sealing member, and a black matrix arranged such that the relationship between the pixel width, black matrix width, and gap between the sealing member and pixel satisfies specific geometric conditions, limiting the viewing angle to prevent others from seeing the image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If organic light emitting display apparatus uses conventional wide viewing angle design, then image quality and brightness are improved, but privacy is compromised as others can view the displayed images
Solution Approach 1:
The patent applies local quality by creating different optical properties in different regions of the display. The black matrix is positioned at specific locations (overlapping with pixel edges when viewed from certain angles) to selectively block light in specific viewing directions while maintaining wide viewing angle for the intended user. This localized light blocking creates privacy protection zones without compromising overall display brightness for the user.
Solution Approach 2:
The patent employs asymmetry in the geometric arrangement of the black matrix relative to the pixels. The black matrix is positioned asymmetrically such that when viewed from angles greater than the critical angle, the black matrix overlaps with the pixel edges, blocking light from reaching side viewers. This asymmetric configuration creates direction-dependent light blocking that protects privacy while maintaining normal viewing experience.
2Object-affected harmful factors
If black matrix is added to limit viewing angle for privacy, then privacy is improved, but device complexity increases
Solution Approach 1:
The black matrix serves multiple functions simultaneously: it acts as a light blocking element for privacy protection, defines pixel boundaries, and maintains structural integrity of the display. By making the black matrix multi-functional, the patent avoids adding separate privacy protection components, thereby limiting complexity increase while achieving privacy protection.
Solution Approach 2:
The black matrix automatically performs privacy protection based on its geometric positioning and the optical properties of the display. The critical angle for light blocking is determined by the geometric relationship between the black matrix position and pixel dimensions, allowing the structure to self-regulate viewing angle without requiring active control mechanisms or additional components.
3Object-affected harmful factors
If black matrix overlaps with pixel to limit viewing angle, then privacy is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent defines the critical viewing angle through geometric parameters (black matrix position, pixel dimensions, and their relative positioning) rather than requiring precise angular control during manufacturing. By expressing the viewing angle limitation in terms of controllable linear dimensions and geometric relationships, the patent makes the manufacturing process more feasible while maintaining effective viewing angle control for privacy.
Data Source
AI summary
An organic light emitting display apparatus includes a first substrate, a plurality of organic light emitting pixels formed on the substrate, a second substrate bonded to the substrate to seal the organic light emitting pixels. A black matrix layer is formed on a surface of the second substrate facing the first substrate and provides a plurality of openings. One of the openings and one of the pixels are aligned. The pixel has a first edge and a second edge and the opening has a first edge and a second edge. The first edge of the pixel is closer to the first edge of the opening than the second edge of the opening. The two edges of the opening are interposed between the two edges of the pixels when viewed from a direction perpendicular to the surface. Where L is an imaginary straight line passing the first edge of the pixel and the second edge of the opening in an imaginary plane perpendicular to a direction in which the edges extend, the imaginary line L and the first surface form an acute angle which is greater than about 30° and smaller than about 45°.