HFS Technology

Release time:Dec,09,2022 Source:TCL华星

Introduction to HFS Technology 

HFS technology refers to FFS (Fringe Field Switch) technology independently developed by TCL CSOT, "H" is taken from the initials of "CSOT" (Huaxing in Chinese pinyin) and represents High Tr% Field Switching. FFS is a technology that enables liquid crystal molecules between electrodes and directly above the electrodes to rotate on a flat surface parallel to the glass substrate through an fringe electric field generated between the top strip pixel electrodes and the bottom common electrodes on the thin-film transistor substrate. 

HFS uses negative liquid crystal plus optical alignment technology, with H-HFS new pixel structure design, has higher transparency (transparency can be up to 15%), achieves leadership in product power consumption and energy efficiency, brings low-carbon life to users, and achieves ultra-long life convenience. 

The dark state of HFS technology is darker, and bright state is brighter; the contrast of traditional FFS technology products is mostly 1000:1, and the contrast of HFS products can exceed 2000:1. HFS products have absolute advantages over traditional FFS technology in contrast, and can solve uneven display problems such as mura. Its optical quality is better, which provides users with a better visual experience. 

The self-developed HFS technology can effectively improve the narrow viewing angle problem, and the horizontal and vertical viewing angles can reach 178°. Display technology with Strip architecture can reduce screen power consumption to 15W. It is green and environmental, energy-saving and power-saving, and meets the national standards for energy-saving. At the same time, the excellent algorithm can meet the user's needs for more sensitive and fast operation response. 

At present, TCL CSOT HFS technology has been widely used in TV, monitor, laptop and other fields. 

 

Background of Launching HFS Technology 

With the rapid development of the new generation of information and communication technology such as mobile internet, 5G communication, Internet of Things, cloud computing, big data, etc., the market demand for LCD TV, smartphone, tablet and other consumer electronics products and smart home products as application terminals continues to grow, and the output of smart terminals continues to climb. TCL CSOT 8.6 Generation Oxygen Semiconductor New Display Device Production Line Project (TCL CSOT Guangzhou t9 Project) is the first advanced LCD panel production line specializing in high-end IT products and professional displays in China. As an important strategy for TCL CSOT to become a global leader in semiconductor display field, it was officially put into production on September 29, 2022, filling the gap in the company's technological route and will be used to enrich the company's IT, on-board professional display and other previously relatively weak product lines; by using the self-developed HFS and high mobility oxide technology of TCL CSOT, it can produce products with larger size, higher transparency, higher refresh rate and higher resolution, in order to achieve a breakthrough in the company's mid-size business strategy and create new momentum for business growth. 

 

Features of HFS Technology 

1. High transparency 

HFS uses negative liquid crystal plus optical alignment technology, with H-HFS new pixel structure design, has higher transparency (transparency can be up to 15%), achieves leadership in product power consumption and energy efficiency, brings low-carbon life to users, and achieves ultra-long life convenience. 

Since the LCD panel itself does not emit light, it depends on the light source provided by the backlight to display brightness. Therefore, the transparency becomes an important optical parameter of the LCD panel, and its size directly affects the power consumption of the entire display. If the transparency is high, the brightness requirement for the backlight will be reduced, and the power consumption of the overall module will be reduced. HFS uses negative liquid crystal plus optical alignment technology, with H-HFS new pixel structure design, has higher transparency (transparency can be up to 15%), achieves leadership in product power consumption and energy efficiency, brings low-carbon life to users, and achieves ultra-long life convenience. 

2. High contrast 

The dark state of HFS technology is darker, and bright state is brighter. The contrast of traditional FFS technology products is mostly 1000:1, and the contrast of HFS products can exceed 2000:1. HFS products have absolute advantages over traditional FFS technology in contrast, and can solve uneven display problems such as mura. Its optical quality is better, which provides users with a better visual experience. 

Contrast is the rate value of brightness at the brightest (white) point to that at the darkest (black) point on the screen. High contrast means a relatively high brightness and a brighter degree of color rendering. The larger the contrast, the clearer the image and the brighter the color. Small contrast can make the whole picture gray. High contrast is very helpful for the sharpness, detail and gray level of the image. HFS products have an absolute advantage over traditional FFS technology in contrast, which provides users with a better visual experience. 

Comparison of HFS Technology with Other Technologies in the Industry 

Both FFS and IPS utilize the rotatory properties and phase retardation effect of liquid crystal. The liquid crystal molecule rotates only in a plane and combines with POL to control the light passage. Compared with the IPS technology, FFS technology has the advantages of high aperture rate, low power consumption and low cost, especially CSOT HFS which has higher transparency and contrast than traditional FFS technology due to the unique pixel design. Compared with VA technology, HFS is an iterative upgrade technology, which performs better in the visual angle, refresh rate, compression water ripple, etc. 

1. Comparison with traditional IPS Technology 

IPS and HFS are planar control mode wide angle technologies. IPS technology includes S-IPS and AS-IPS. S-IPS uses multi-domain structure to improve color bias. AS-IPS uses ITO electrodes instead of metal electrodes on S-IPS to effectively increase the aperture rate. IPS pixel electrodes and COM electrodes are set at the same layer, which has a greater dependence on the line width of the pixel electrodes. HFS pixel electrodes and COM electrodes are set at interval, so that the edge and the top of the pixel electrodes can achieve effective light transmission with the effect of fringe electric field. At the same time, HFS does not need to use organic membranes, which can reduce costs. Compared with IPS technology, HFS technology has significant advantages in aperture rate, low power consumption and low cost. 

2. Comparison with traditional VA Technology 

Compared with VA technology, HFS technology has significant advantages in dynamic sharpness, color restoration accuracy, visual angle, compression water ripple, etc. At the same time, HFS also performs better in Freesync, flicker, Cross talk and touch integration. The advantage of VA is high contrast, but HFS technology can achieve darker dark state and brighter bright state, and the contrast of HFS products can exceed 2000:1. 

3. Comparison with traditional FFS Technology 

HFS uses negative liquid crystal plus optical alignment technology, with H-HFS new pixel structure design, has higher transparency; the dark state of HFS technology is darker, and bright state is brighter. The contrast of traditional FFS technology products is mostly 1000:1, HFS product contrast can exceed 2000:1, so HFS products have absolute advantages over traditional FFS technology in contrast; at the same time, it can solve uneven display problems such as mura; its optical quality is better, which provides better visual experience for users. 

 

Products carried with HFS Technology 

1. MNT product line 

TCL CSOT, adhering to the advantages of HFS technology, is applied to display products with fast response, large viewing angle, accurate color and excellent dynamic picture. At the same time, the transparency of HFS is further improved and the energy consumption of products is continuously reduced. A new type of light-resistant material is used to protect eyes with low blue light. Optical alignment improves contrast, makes Color shift perform better, and avoids the problem of rubbing mura. 

(1)  TCL CSOT’s first 27 "FHD HFS MNT" 

This is the first a-Si HFS MNT product of TCL CSOT, with the ultimate 4 Mask process, leading the industry. With DLS pixel architecture, the cost is 30% lower than 1G1D COF, and the energy consumption reaches ES8.0/TCO9.0 by using positive LC + optical alignment technology. 

The whole machine has  high transparency of 5.1%, high contrast of 1300:1 and super wide viewing angle of 178°, low blue light, immersive viewing experience. 

 

2. Notebook product line 

TCL CSOT Notebook products currently cover the four core technologies of In-Cell touch control, MLED, HFS, and printing OLED. In-Cell touch technology supports 120Hz hand touch, making it more sensitive and fluent when users touch the screen. At the same time, In-Cell integrates touch sensors into a single screen, effectively reducing the cost increase of add-on CG and the increase of model thickness, making the screen thinner. MLED and printing OLED greatly enhance the picture quality color of the screen, while HFS also improves the refresh rate and response speed of the screen. 

(1) 16" 2.5K Oxide Broadband Display  

This is a 16" 2.5K LCD high-order laptop display based on IGZO HFS. 

Unlike general a-Si based products, this product uses IGZO backplane technology with better electrical characteristics, so the product frame can reach 2.5um and the power consumption can be significantly reduced. Secondly, the product uses the industry-leading negative liquid crystal + optical alignment Cell technology scheme, the transparency can be increased by 10% compared with the products of the same specifications on the market. In addition, TCL CSOT HFS has been applied to make the color display more vivid, with a gamut up to 100% sRGB, higher gamut coverage and contrast, and stronger color expression, which can meet the highest display requirements of professional display users. To sum up, this product has a significant advantage in power consumption on the basis of leading picture quality. 

 

(2) 14" FHD Ln-Oxide Demux Display 

This is based on the Ln-oxide high-mobility oxide technology developed independently in China. It is first applied to 14-inch FHD Demux HFS NB products. The high-mobility Ln-Oxide target developed by TCL CSOT in cooperation with NVO is used as the semiconductor layer, which solves the common low mobility problem and achieves proprietary intellectual property. Its mobility rate can exceed 25cm2/ (V.s) and provides a richer visual experience. With the unique Demux 1:3 architecture, MOD requires only one IC, which greatly reduces its production costs. The refresh rate is compatible with 10~60Hz drive, which makes the display flicker-free and no jamming at low frequencies. When the power consumption is greatly reduced, the service becomes more durable. 

At the same time, TCL CSOT jointly set up Oxide Joint Laboratory with South China University of Technology, New Horizon and Juhua to develop new high mobility oxide technology independently, which can be used in laptop Demux (Demux-demultiplexed) products, reduce IC usage and increase product benefits. It is also applied to active Mini/Micro LED products, resulting in increased brightness and reduced power consumption; these products are under development and will be released one after another. 

 

3. TV panel product line 

The self-developed HFS of TCL CSOT can effectively improve the narrow viewing angle when applied in TV panel, with both horizontal and vertical viewing angles reaching 178°. Strip-based display technology can effectively reduce screen power consumption, which is green and environmental, energy-saving and power-saving, and meets the national energy-saving standards. With excellent algorithms, it can meet the needs of users for more sensitive and fast operation response. At the same time, high contrast makes the performance of picture layers more distinct, objects more three-dimensional, color performance more powerful. 

(1) TCL CSOT’s First HFS 50" UD LCD TV

TCL CSOT is continuously improving in product category layout. At the end of September this year, a new production line of 8.6th generation oxide semiconductor display devices, namely Guangzhou CSOT t9 production line with 180K glass substrates monthly, has been officially put into production, which is important for strengthening TCL CSOT in high-end and professional display fields. 

This product is an HSS display mode product independently developed by TCL CSOT t9 project. It is also the first 50" 4K HFS LCD TV of TCL CSOT. It has the feature of 120 Hz refresh rate of DLG (Dual Line Gate). It enables the display to be tear-free, non-jammed and supports the best picture display and visual perception. Its contrast can reach 1200:1, and the color gamut coverage reaches 72%, which can make the color display more vivid, bright and dark contrast more intense, and give users a richer visual experience. Ultra-high definition and detailed picture quality also make the image more distinct, brightness and clarity are improved in an all-round way, perfectly restoring every detail. 

The self-developed HFS technology can effectively improve the narrow viewing angle problem, and the horizontal and vertical viewing angles can reach 178°. Display technology with Strip architecture can reduce screen power consumption to 15W. It is green and environmental, energy-saving and power-saving, and meets the national standards for energy-saving. At the same time, the excellent algorithm can meet the user's needs for more sensitive and fast operation response. 

In terms of appearance, 3-Side Bezel Less (3-side no bezel design) makes the appearance more stylish and elegant, effectively reduces the limit of the bezel on the visual perception, the whole machine picture is more spectacular and brings a visual feeling out of the frame.