Direct-Type Backlight Layout for Thin HDR Display Uniformity
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Solution Overview
Problem
Liquid crystal displays using edge type backlight units struggle to achieve high dynamic range imaging due to limitations in luminance variation across the display screen and difficulty in achieving uniform surface light distribution, while existing direct type backlight units with lenses hinder thickness reduction.
Innovation Solution
A display apparatus employing a direct type backlight unit with a light guide plate featuring light source grooves and a reflection sheet, which spreads light laterally without a separate lens, combined with light emitting diode packages having reflectors to improve uniformity and reduce thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a direct type backlight unit with a lens is used to spread light laterally, then light uniformity is improved, but the thickness of the display apparatus increases
Solution Approach 1:
The patent extracts and eliminates the lens component from the backlight unit. Instead of using a lens to spread light laterally, the invention uses a light guide plate with light-emitting diodes arranged in a specific pattern to achieve light uniformity without the thickness penalty of a lens
Solution Approach 2:
The patent introduces a light guide plate as an intermediary component between the light-emitting diodes and the display panel. The light guide plate serves as a mediator that redistributes light laterally through its structure, replacing the function previously performed by a lens
2Length of stationary object
If an edge type backlight unit is used to reduce thickness, then the thickness of the display apparatus is reduced, but high dynamic range imaging cannot be realized
Solution Approach 1:
The patent applies local quality by varying the arrangement and density of light-emitting diodes in different regions of the backlight unit. This allows different luminance levels to be achieved in different areas, enabling high dynamic range imaging while maintaining a thin profile
Solution Approach 2:
The patent transitions from a one-dimensional edge type backlight to a two-dimensional direct type backlight arrangement. By distributing light-emitting diodes across the entire backlight area rather than along an edge, the system achieves both thinness and high dynamic range imaging capability
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 enables high dynamic range imaging with improved light uniformity and reduces the thickness of the display apparatus by eliminating the need for a separate lens, enhancing the display's overall performance and compactness.
Implementation Method 1
a light guide plate disposed between the frame and the optical part to cover the plurality of light emitting diodes. The light guide plate is formed with light source grooves placed corresponding to locations of the plurality of light emitting diodes, respectively, such that light emitted from each of the light emitting diodes enters the corresponding light source groove
Implementation Method 2
A display apparatus employing a direct type backlight unit with a light guide plate featuring light source grooves and a reflection sheet, which spreads light laterally without a separate lens
Data Source
AI summary
A display apparatus including a frame, light emitting diode chips separated from each other and regularly arranged in a matrix on the frame, an optical part including a display panel and at least one of a phosphor sheet and an optical sheet, a light guide plate disposed between the frame and the optical part to cover the light emitting diode chips, at least one reflector disposed between the frame and the light guide plate to reflect at least part of light emitted from the light emitting diode chip to direct at least part of light emitted therefrom to the light guide plate, and a first-type electrode and a second-type electrode, in which at least one of the light emitting diode chips is a flip-chip type and includes a first-type semiconductor layer electrically connected to the first-type electrode and a second-type semiconductor layer electrically connected to the second-type electrode.