Skyworth Q72 Smart MiniLED TV 2023

Glossary

Table of contents

General introduction

Objectives of the report

Will MiniLED in displays survive microLED (and OLED)?

About PISÉO

About DXOMARK

About the authors

Related products

Companies cited

Synthesis of PISÉO’s and DXOMARK’s analysis

• MiniLED BLU principles
  • LCD Principle
  • LCD Challenges
  • Global vs. Local Dimming
  • Local dimming evolution
  • Edge vs. Direct configurations
  • Optical Distance
• Skyworth Q72 Smart MiniLED TV - characteristics
  • MiniLED and Quantum-Dots-based BLU
  • Skyworth Q72 Smart MiniLED Architecture
• Skyworth Q72 Smart MiniLED TV - BLU construction
  • BLU – Display opening
  • BLU Opening
  • BLU – Optical Distance and MiniLED arrangement
  • BLU Opening
  • BLU – Optical stack
  • BLU – Optical films seen under microscope
• Skyworth Q72 Smart MiniLED TV - Performance analysis
  • Color
  • Video content - Color
  • Video - color HDR10
  • BLU – Emission spectra
  • BLU – Colorimetric measurements
  • Luminance / Brightness
  • Video content - Brightness
  • Video content – Brightness uniformity
  • Goniophotometry
  • BLU – Blue light luminance uniformity
  • BLU – White Luminance – Luminance enhancement
  • BLU – Optical film LUM#3
  • BLU – Optical films OPT#4 and OPT#5
  • Contrast & halo
  • Video content - halo
  • BLU – Local dimming zones
  • Artifacts – Flicker

Conclusion and opinions

Skyworth Q72 TV Display analysis

• Content
  • Purpose of this presentation
  • Our activities
  • DXOMARK Display Testing Lab – Main setups
  • Test conditions
  • Display testing scope
  • Measuring instruments
  • Summary – Overall takeaways
• Video content
  • Video content – Overview
  • Video content – Brightness
  • Video content – Contrast
  • Video content – EOTF
  • Video content – HDR10 EOTF
  • Video content – SDR EOTF
  • Video content – Brightness Uniformity
  • Video content – Color uniformity
  • Video content – Angular Behavior
  • Video content – Brightness vs. angle
  • Video content – Contrast vs. angle
  • Video content – Color vs. angle
  • Video content – Color
  • Video content – Color HDR10
  • Video content – Halo
• Artifacts 
  • Artifact – Overview
  • Artifacts – Flicker
  • Artifacts – Reflectance

Skyworth Q72 Smart MiniLED TV BackLight Unit Analysis

• Our approach, how do we work?
• Introduction
  • LCD Principle
  • LCD challenges
  • Global vs. local dimming
  • Local dimming evolution
  • Edge vs. direct configurations
  • Optical distance
  • Direct backlights
  • MiniLED and Quantum-Dots-based BLU
  • What is a Quantum Dot?
  • QDEF
  • Skyworth Q72 Smart MiniLED Architecture

Deep dive in the backlight unit (BLU)

• BLU – Display opening
• BLU opening
• BLU – COG MiniLED
• BLU – Optical distance and MiniLED arrangement
• BLU – MiniLED
• BLU – Optical stack

Backlight unit photometric characterization

• PISÉO’s photometric LAB
• BLU – Emission spectra
• BLU – Colorimetric measurements
• Goniophotometry
• BLU – Blue light Luminance uniformity
• BLU – White Luminance – Luminance enhancement
• BLU – Local dimming zones

Backlight unit optical films

• BLU – Optical films seen under microscope
• BLU – Optical Stack description
• BLU – Optical film OPT#2
• BLU – Optical film LUM#3
• BLU – Optical films OPT#4 and OPT#5
• BLU – Optical film OPT#6
• Conclusion

ABOUT PISÉO

• PISÉO - independent innovation center
• Markets and Product Types
• PISÉO, In brief
• Contacts

Report based on PISÉO and DXOMARK collaboration

To evaluate the benefits of this new type of backlight, DXOMARK and PISÉO – leaders in the assessment of consumer electronics quality and photonic systems architecture, respectively – have teamed up to produce this report.

DXOMARK carried out visual performance measurements at display level, in order to evaluate the quality of the Skyworth Q72 Smart MiniLED TV. The test results and the performance analysis are presented in this report, and cover:

• Video at high and standard dynamic range (HDR and SDR): brightness, contrast, EOTF, color, angular performance, halo
• Artifacts: flicker, reflectance

To understand the technology of the Skyworth Q72 Smart MiniLED TV backlight, PISÉO analyzed the optical architecture of the backlight unit by:

• Disassembling the Skyworth Q72 Smart MiniLED TV to access the backlight unit
• Delayering the optical stack integrated between the MiniLED array and the LCD panel
• Analyzing the material and the mechanical structure of each layer
• Analyzing the optical properties of each layer
• Analyzing the LED emission characteristics and the local dimming features at LED board level

Based on their individual analyses, DXOMARK and PISÉO then carried out a cross-analysis to show the links between the user experience and the backlight’s optical construction.

Independent BLU architecture and performance analysis

With the Q72 Smart MiniLED TV, Skyworth claims to provide better local dimming – and by using chip-on-glass technology combined with active matrix addressing, a more balanced level of brightness to the screen. Through its Skyworth Super Original Color Tech, which uses a Nanolumi Chameleon® G Film added to the original compounds backlight structure, Skyworth also claims to improve color purification to generate pure RGB colors.

In order to understand the technology of the Skyworth Q72 Smart MiniLED TV backlight, the optical architecture of the backlight unit was analyzed by PISÉO and presented in this report. Among the covered topics, this architectural analysis deals with the chip-on-glass technology, the optical distance, and a description of the seven optical films integrated between the MiniLED array and the LCD panel.

To assess the performance of the backlight unit, PISÉO characterized the emission spectra generated by the MiniLED and the intermediate spectra as the light passes along the various optical layers, up to the resulting spectra of the light leaving the complete optical stack. PISÉO also carried out colorimetric, brightness level & uniformity, and light distribution measurements.

Analysis of the backlight unit's architecture shows that the Skyworth Q72 Smart MiniLED TV's backlight has a higher number of zones, a smaller number of LEDs per zone, and a smaller zone dimension compared with other MiniLED displays analyzed by PISÉO and DXOMARK. This report then answers the question of whether this promising architecture of the backlight unit is reflected in the screen's performance in terms of contrast and halo.

Some outstanding performance and room for improvement for the Skyworth Q72 Smart MiniLED TV

Brightness is currently a strength of MiniLED technology compared to OLED. As such, the backlight unit of the Skyworth Q72 Smart MiniLED TV performs well in terms of brightness. Moreover, based on PISÉO’s experience, its brightness performance is outstanding even when compared with all the MiniLED displays analyzed by PISÉO to-date.

Among other parameters, color reproduction is a challenge for MiniLED to compete with OLED technology. PISÉO has analyzed the color conversion layer of the Skyworth Q72 Smart MiniLED TV’s backlight unit and the resulting performance. The results are quite remarkable, with color gamut coverage reaching ~85% of the rec2020 standard gamut.

This report also deals with other findings by PISÉO regarding the construction of the color conversion layer, the viewing angles, the color shift, and the backlight unit’s brightness uniformity. Some findings point to remarkable design approaches and performance, while other findings highlight room for improvement and limitations.

While the backlight unit of the Skyworth Q72 Smart MiniLED TV differentiates itself from other MiniLED backlight units through significantly better performance and architectural choices, at display level the end-user doesn’t always benefit from these identified advantages.

Luminit, Nanolumi, Samsung, Skyworth, TCL

Key Features

• Description of the MiniLED-based backlight unit technology.
• Details about LED emission characteristics.
• Main characteristics and roles of the different films in the optical stack.
• Measurement and analysis of brightness, brightness uniformity, contrast, EOTF, color, color uniformity, angular performance, halo in video, and high and standard dynamic range (HDR and SDR) formats.
• Backlight unit operation when displaying a simple scene.
• Measurement and analysis of artifacts such as screen reflectance and flicker.
• PISÉO’s opinion on the architecture and performance of the product.

Product objectives

• While manufacturers are announcing displays based on MiniLED, Skyworth claims a better local dimming and the use of Nanolumi Chameleon® RG Film combined with Quantum Dots technology to improve color purification.
• This report discusses the tests and quality analyses that have been performed to evaluate the performance of the Skyworth Q72 Smart MiniLED TV.
  • Readability and color in various ambient light conditions, APLs, and angles;
  • Improvement in brightness and contrast brought by the MiniLED LCD.
• It also details the MiniLED backlight unit of Skyworth Q72 Smart MiniLED, giving insights into the optical architecture and explaining how Skyworth managed the technical challenges.
  • What is the MiniLED based backlight unit?
  • How is it made?
  • Provide details of the LED emission characteristics.
  • Share the main characteristics of the seven films in the optical stack.
  • Explain the role of the different films.
  • Show how the backlight unit works when displaying a simple scene.
• Finally, it shows how the new backlight optical construction contributes to the user experience.