tft lcd eye strain made in china

As we all know, AMOLED screen is a screen made of self-luminous organic materials. It does not require LCD backlight. When current passes through organic materials, pixels will emit light by themselves. Therefore, compared to LCD screens, AMOLED has more Pure black, higher contrast and other display advantages.

However, being more "ideal" also means paying more. The "eye-damaging" of AMOLED displays stems from external dissatisfaction with the current widespread adoption of PWM low-frequency dimming by AMOLED manufacturers. Here is a brief explanation of the PWM low frequency dimming technology.

LCD screens rely on LED backlight panels to emit light. Therefore, in the field of smart phones, LCD screens mostly use DC dimming. This is a technology that directly adjusts the brightness of the two sides of the light-emitting component to adjust the brightness. The smaller the current, the lower the brightness.

DC dimming is relatively straightforward, but it also has a big disadvantage. Due to the different wavelengths of the three primary colors, DC dimming can cause unavoidable color casts under extremely low brightness conditions, such as early LCD displays with DC dimming , At low brightness, there will be obvious problems of discoloration.

Unlike DC dimming, which directly adjusts the current to control brightness, PWM dimming is more clever. Everyone knows that switching the light source will cause flicker. The faster the switching speed, the faster the flicker. When the frequency of switching the light source exceeds the limit of the human eye, the brightness of all pictures is superimposed in the human eye, so the frequency will affect the brightness of the screen. This technique is called PWM dimming (pulse width modulation).

However, with PWM dimming, even if the human eye cannot sense the picture change during the switching process, we will respond to this phenomenon. It is more likely to cause fatigue on the muscles on both sides of the eyes, thereby stimulating the refraction system to accelerate vision Ageing.

At present, Samsung ’s AMOLED screens use 250Hz low-frequency PWM dimming technology. When the screen brightness is lower, the possibility that the human eye can perceive becomes larger, and it is more likely to affect sensitive people.

AMOLED displays that use PWM low-frequency dimming for a long time do seem to affect vision, but do n’t think that LCD can survive. Even with DC dimming, it also has an irreversible effect on vision-cannot be ignored Blu-ray hazard.

Different from the AMOLED self-emission mode, the LCD screen uses a combination of backlight and filter imaging. In mainstream technology, many LCD screens will use blue LED backlight panels, which are covered with red, green and colorless three. This kind of filter forms three primary colors of RGB when blue light passes through these three filters.

Among them, the short-wave blue light emitted by the blue backlight board can cause harm to human eyes. Because short-wave light has a greater capacity density and is more penetrating, it will directly penetrate the lens to the retina, causing atrophy or death of retinal pigment epithelium cells.

From a technical point of view, whether it is an LCD or an AMOLED screen, the impact on vision is universal. As far as smartphones are concerned, it cannot be said that AMOLED screens are more eye-damaging than LCD screens.

Even if the LCD party held high the banner that PWM low-frequency dimming is harmful, it could not fully prove that AMOLED screens have an impact on vision, because everyone"s habits of using mobile phones are different, and the impact on everyone is different. There is no doubt that in the end, it is still the habits that need attention. For example, users should try to avoid watching the phone screen for a long time; reduce the viewing time of LCD and AMOLED low brightness in the dark environment.

ROSEVILLE, CA – February 3, 2022— New Vision Display (“NVD”) is pleased to announce a unique and new asset for business and personal use: the Sun Vision Display (“SVD”) 32” computer monitor featuring full color reflective LCD technology. This monitor is specifically designed and manufactured to address eye strain and other visual issues that can arise when using traditional LCD and OLED monitors. By eliminating the need for backlighting through SVD’s reflective LCD structure, this monitor provides excellent readability in areas with bright ambient light, that’s true whether the light source is natural or artificial.

SVD 32” monitors improve eye comfort as well as readability through their reflective LCD structure. Instead of utilizing a backlight behind the LCD cell to illuminate the display, each pixel is formed by a diffused mirror, making optimal use of available ambient light. The screen offers full HD (1980 RGB x 1080) resolution and 16.7 million addressable colors, offering deep and rich detail for a variety of use cases. These monitors are intended for personal and professional use indoors, but can also be used outside during calm weather, in the absence of precipitation or high winds.

Near-Eye Display Market to surpass USD 13 billion by 2031 from USD 1. 4 billion in 2021 at a CAGR of 25. 2% in the coming years, i. e. , 2021-2031. Product Overview NEDs, also known as head mounted displays (HMDs) or wearable displays, project a virtual image into one or both eyes’ field of view.

New York, June 30, 2022 (GLOBE NEWSWIRE) -- Reportlinker.com announces the release of the report "Near-Eye Display Market Segmentation: By Device Type, By Components, By Technology, By Vertical, And Region – Global Analysis of Market Size, Share & Trends For 2019–2021 And Forecasts To 2031" - https://www.reportlinker.com/p06288804/?utm_source=GNW

To the naked eye, the virtual image appears to be considerably larger than the comparatively small display panel and optics employed to make it. Near-eye displays are the headphones of the display industry, allowing users to create compact, portable, and personal viewing experiences. Near-eye displays provide several advantages over standard displays, including their small size, portability, light weight, low power consumption, and ability to be see-through.

Global Near-Eye Display Market to surpass USD 13 billion by 2031 from USD 1.4 billion in 2021 at a CAGR of 25.2% in the coming years, i.e., 2021-2031. Factors driving the growth of the near-eye display market include the increased use of OLEDoS micro displays in novel applications such as projection, imaging, smart glasses, and the rapid acceptance of AR devices in many verticals.

By Device Type, the global Near-Eye Display Market is divided into AR Devices, VR Devices, Others (EVF and MR Devices). In past years, VR devices dominated the near-eye display industry. Near-eye display-based HMDs power these gadgets, which deliver a totally digital experience that simulates a three-dimensional environment in the real world. Near-eye displays are widely used in VR systems since they are inexpensive and can be mass-produced by Asian manufacturers. By allowing users to immerse themselves in a highly realistic environment, virtual reality gadgets have transformed consumer applications.

On the basis of technology, the global Near-Eye Display Market is fragmented into TFT LCD, AMOLED, LCoS, OLEDOS, MicroLED, DLP, and Laser Beam Scanning. The market for near-eye displays was dominated by TFT LCD technology. This technology allows for lightweight, small displays with great resolution and low power consumption. These displays can also be mass-produced and widely used in virtual reality systems. These reasons are propelling the market for TFT LCD near-eye displays forward.

The rise of the metaverse, the spike in the use of OLEDoS tiny screens, and the expanding use of AR and VR devices all contribute to the market’s promising growth potential. The advent of the Metaverse, as well as increased investments and innovations from technology heavyweights, will play a crucial role in moving the near-eye display market forward in the near future. Due to enhanced qualities such as greater contrast, faster response time, lower weight, more compact size, negligible image blurring, and a wider operational temperature range than LCDs, OLEDoS micro displays are gaining traction. Since they are widely employed in EVFs and HMDs, they have outperformed traditional LCD and LCoS micro display technologies.

Health difficulties among gamers are on the rise, thanks to the introduction of AR-based gaming devices. AR games are extremely engaging and keep users interested for extended periods of time, leading to difficulties including anxiety, eye strain, obesity, and a lack of concentration. Since AR technology is immersive, it can cause anxiety or worry when worn for extended periods of time. AR devices expose consumers to dangerous electromagnetic frequency radiation, which can cause disease, in addition to stress.

Global Near-Eye Display Market is segmented based on regional analysis into five major regions: North America, Latin America, Europe, Asia Pacific and the Middle East and Africa. Due to the growing adoption of AR and VR technologies by the consumer and medical verticals, the near-eye display market in Asia Pacific is predicted to grow at the fastest CAGR. China’s market growth can be ascribed to the fact that it is one of Asia Pacific’s major consumer electronics marketplaces. The widespread availability of lightweight, low-cost near-eye display-based HMDs in Asia Pacific will encourage more enterprises in the region to invest in AR and VR HMDs. These reasons are expected to boost the near-eye display market’s growth in the near future.

As with all studies, this study has some limitations which prevent generalizability. The subjects in this study are mainly students between 21 and 26 years old. It would be interesting if other age ranges are included since medical workers are diverse in age and have different visual health accordingly, which might or might not impact their reading of the interface when their protective eye gear is fogged up. Aarts et al. [47] found that the error rates are age dependent when reading drug labels under the same ambient lighting. At the same time, the subjects are students and not medical personnel. Therefore, their evaluation of interface information may differ from that of medical professionals. The environment of this study does not have the same degree of intensity as a real life hospital would have, so the cognitive load might not be the same. As such, the results might have some degree of deviation with real life situations. Therefore, taking into account the actual use and environment, future research could consider other age ranges, involvement of professional medical staff in the experiment, and use of electrocardiographs to evaluate their visual recognition efficiency.

The visual health of microscope workers is an important occupational health concern, and a previous study suggested an association between lighting problems (e.g., flashing light, insufficient lighting) and eye symptoms among cleanroom workers in the electronics industry. This study aimed to explore the association between eye symptoms and lighting problems, as well as light-related counteracting behaviors among microscope workers in the cleanroom environment. Ninety-one cleanroom workers aged 20 years or older were recruited from an electronics factory. The socio-demographic factors, work-related factors, eye symptoms, and lighting problems were assessed using a self-administered questionnaire. There were 92.3% female participants in this study. Among all participants, 41.8% and 63.7% had symptoms of dry eye and eye fatigue, respectively. The counteracting behaviors of needing to move closer (adjusted odds ratio (aOR) = 3.47, 95% CI = 1.11 to 10.88) was significantly associated with dry eye symptoms. Workers who were more experienced at the job (aOR = 1.03, 95% CI = 1.01 to 1.06) and had shorter break times (aOR = 0.94, 95% CI = 0.91 to 0.98) were more likely to have eye fatigue. As a result of these findings, this study suggests that good lighting and adequate break times are crucial to improve the visual health of cleanroom microscope workers.

The electronics industry is estimated to have 18 million workers employed worldwide in 2010 [1], and the estimated growth of this industry was around 4% between 2016 and 2017 globally [2]. East Asian countries including Japan and Taiwan contribute to over 50% of the global export values. To ensure the quality of the products, small electronic components are generally manufactured in cleanrooms with controlled temperature, humidity, and air particulate matter concentration [3]. Special head-to-toe garments are required to reduce dust or lint exposure, but the garments may limit the field of view and restrict the range of movement, causing discomfort when the workers remain fully suited during the entire work shift. High prevalence of dry eye symptoms has been reported among cleanroom workers, and the symptoms may be reduced by allocating adequate working hours and wearing protective eyewear [4,5]. Common light hazards in the cleanroom environment include poor lighting, special lamp design (e.g., yellow light), high illuminance (e.g., microscope), and low illuminance (e.g., light-on test) [4]. These hazards may result in lighting problems, such as disability glare, discomfort glare, flicker, and veiling reflections, and cause eye discomfort [6,7,8]. Toomingas et al. indicated that non-optimal visual conditions (e.g., poor lighting, glare) was an independent risk factor for eye symptoms [9]. Although prior studies reported that dry eye symptoms at the workplace are associated with poor lighting, female gender, cleanroom, long employment duration, family history of atopic disease, and low humidity [5,10,11], the association between different lighting problems and eye symptoms among cleanroom workers is rarely addressed. Furthermore, dry eye syndrome may also be more prevalent in people of Asian and Hispanic origin [10,12].

Cleanroom workers are often required to manually inspect the products at short distances by eye or with microscopes. Small myopic shifts have been found in previous studies on near work and were suggested to produce eye fatigue [13,14]. The field of view under the microscope tends to have a much higher illuminance than the surrounding environment, and the large differences in illumination between the field of vision of the microscopes and the adjacent working areas may aggravate eye symptoms such as eye fatigue [15]. Indeed, a previous study reported that 59.6% of microscope users in medical laboratories had eye fatigue [16], and a case report describing a pathologist who had severe eye symptoms and myopic complications from occupational exposure to both low-intensity fluorescent light and high intensity light [17]. However, there is insufficient evidence to show if an increased risk of eye fatigue is associated with different lighting problems among cleanrooms workers using microscopes.

Previous studies have found that glare affects people with normal binocular vision and contributes to decreased productivity [18], increased blood flow in the trapezius muscle [19], and an increased blink rate [6]. There are several human adaptations or counteracting behaviors, including eyelid squinting, blinking, and changing postures, to reduce the negative effects of glare [6]. Changing postures and work at close distances could be seen as the behaviors to cope with glare and intensive near-visual work, respectively [6,20]. Although the visual health for cleanroom workers or microscope workers have been reported [5,16,21], the association between counteracting behaviors and eye symptoms among cleanroom workers is rarely addressed. Therefore, the aims of this study were to explore the association between eye symptoms and lighting problems, as well as light-related counteracting behaviors among cleanroom workers in an electronics factory.

The questionnaire collected demographic data, eye symptoms (e.g., dry eye and eye fatigue), non-eye related symptoms, work-related factors, lighting problems, and counteracting behaviors for lighting problems. The demographic data included age, gender, and history of myopia. Questions on eye symptoms were adapted from the Health Aspect of Lighting at Work by Health and Safety Executive [15]. In this study, we defined symptoms of dry eye as the presence of either dryness or irritation according to previous literature [22]. Non-eye-related symptoms including physical fatigue, neck pain, and shoulder pain were surveyed. We also assessed the work-related factors of shift type, experience at the job, working time, break time, duration of visually demanding tasks per working day, duration spent on display screens per working day, and the shortest distance between eyes and objects. With regard to lighting problems, we assessed the perceptions of disability glare (direct interference with vision), discomfort glare (not directly impaired but causing discomfort, annoyance, irritability, or distraction), requirement of color discrimination, flicker, and veiling reflections. One of the adaptations is counteracting behaviors like changing posture. In the study, needing to move closer and frequent shifting to view from different angles were chosen as counteracting behaviors for lighting problems.

All statistical analyses were conducted using SAS 9.4 (SAS Institute Inc., Cary, NC, USA). All data were expressed as frequency (percentage), mean ± S.D., or median (interquartile range). The differences in the distribution of demographic characteristics, work-related factors, lighting problems, and counteracting behaviors between workers with and without symptoms were examined using Student’s t-test, a chi-square test, and a Mann-Whitney U test, respectively. Any factors having a significant difference in the univariable test were selected as candidates for the univariable logistic regression analyses. Univariable logistic regression analyses were performed to examine the potential effect of work-related factors, lighting problems, and counteracting behaviors on symptoms of dry eye or eye fatigue. Multivariable logistic regression analyses were then used to adjust for age, gender, and other significant factors from the univariable logistic regression analyses. The calibration of the model was examined using the Hosmer and Lemeshow Goodness-of-fit test [23]. A p-value of less than or equal to 0.05 was considered statistically significant.

A total of 91 microscope workers (response rate: 67.4%) completed the study. Among them, the majority were females (92.3%), and the average age was 31.5 years old (SD = 5.6). There were 54.9% who had a history of myopia. Thirty-four workers (37.4%) were on the night shift, and the median experience at the job was 14 months (interquartile range = 7–54.3). Workers spent 9.4 h each day staring at the screen on average, and the average shortest distance between eyes and objects was about 30 cm (Table 1). Among the 91 workers, the most prevalent eye symptom was eye fatigue (63.7%), followed by symptoms of dry eye (41.8%), eye itch (22.0%), and blurred vision or sense of oppression (13.2% each). Among non-eye related symptoms, the most frequently reported one was physical fatigue (38.5%), followed by shoulder pain (37.4%) and neck pain (30.8%). Workers with dry eye symptoms were more likely to have a history of myopia (p < 0.01), have physical fatigue (p < 0.01), have shoulder pain (p < 0.01), and have neck pain (p = 0.01) compared with those without dry eye symptoms. On the other hand, workers with eye fatigue were more likely to be female (p = 0.04), have long experience at the job (p < 0.01), have physical fatigue (p < 0.01), have shoulder pain (p < 0.01), have neck pain (p < 0.01), and have short break times (p = 0.01) when compared with those without eye fatigue (Table 1).

VariablesTotal (N = 91)Without Dry Eye Symptoms (N = 53)With Dry Eye Symptoms (N = 38)p-ValueWithout Eye Fatigue Symptom (N = 33)With Eye Fatigue Symptom (N = 58)p-ValueDemographic Characteristics

Regarding the lighting problems, the most frequently declared factor was the requirement of color discrimination (52.7%), but it was not associated with either dry eye or eye fatigue symptoms (Table 2). Overall, 15.4% reported discomfort glare. More workers with dry eye symptoms reported discomfort glare when compared with those without dry eye symptoms (23.7% vs. 9.4%), although the difference was insignificant (p = 0.06). The other reported lighting problems were not significantly different between workers with and without dry eye symptoms (Table 2). Regarding the counteracting behaviors, 29.7% reported that they need to move closer during work, and 25.3% needed to shift frequently to view from various angles. When compared with the workers without dry eye symptoms, more of those with dry eye symptoms had to move closer (p < 0.01) or shift frequently (p = 0.03). On the other hand, workers with eye fatigue were more likely to move closer compared with those without eye fatigue (p = 0.02).

The results of multivariable logistic regression analyses for factors associated with dry eye and eye fatigue symptoms are shown in Table 3 and Table 4, respectively. Needing to move closer was associated with dry eye symptoms after adjusting for sex, age, history of myopia, and frequent shifting to view from different angles (adjusted odds ratio (aOR) = 3.47, 95% CI = 1.11–10.88) (Table 3). Table 4 showed that experience at the job (aOR = 1.03, 95% CI = 1.01–1.06) was associated with eye fatigue and break time (aOR = 0.94, 95% CI = 0.91–0.98) had a protective effect on eye fatigue after adjusting for sex, age, break time, and needing to move closer. The p-values of the Hosmer and Lemeshow goodness-of-fit test were 0.70 and 0.81 for the two models, respectively, indicating good fitness of the models.

The present study explored the effect of lighting problems and workers’ counteracting behaviors on eye symptoms among a special occupational population, which is the cleanroom microscope workers. Cleanroom microscope workers in the electronics industry are required to perform visually demanding work, but no previous study, to our knowledge, has explored the effect of lighting problems on different eye symptoms among these workers. We found that 41.8% and 63.7% of workers had symptoms of dry eye and eye fatigue, respectively. More workers with dry eye symptoms reported disability glare and discomfort glare than those without dry eye symptoms (23.7% vs. 13.2%; 23.7% vs. 9.4%, respectively). After adjusting for other factors, the counteracting behaviors of needing to move closer were significantly associated with dry eye symptoms. Moreover, experience at the job was a risk factor and break time was a protective factor of eye fatigue after adjusting for other factors.

Some studies that examine the association between work-related factors and dry eye symptoms [10,11] report that poor lighting, low humidity, and employment duration were considered as risk factors of dry eye in cleanroom [5]. The present study found that workers with dry eye symptoms reported a high prevalence of disability and discomfort glare, compared with those without dry eye symptoms. One possible reason accounting for the association between glare and dry eye symptoms is that glare put additional stress on the visual system [6]. Although glare has been reported to increase blink rates [6], subjects viewing electronic displays have a higher prevalence of incomplete blinks (occurring when the upper eyelid is unsuccessful in cover the entire corneal surface) [24], which may cause dry eye symptoms due to significant tear evaporation and tear break up [25]. Furthermore, the cleanroom microscope workers had prolonged high demand in performing visual inspections, which is a task with a high cognitive demand. Rosenfield et al. have found that high cognitive demand results in a significant reduction in mean blink rate [24], and Li et al. indicated that while eyes are focused on close objects, the number of blinks is decreased [26]. Taken together, we speculate that dry eye among these cleanroom workers may be associated with glare through changes in blink rates. The association between counteracting behaviors and dry eye symptoms among cleanroom workers is rarely addressed, and the present study further found that the counteracting behavior of needing to move closer was significantly associated with dry eye symptoms. It is possible that workers exposed to glare had a high prevalence of dry eye symptoms (Table 2), and were more likely to change posture to reduce glare [6,20]. During near work, counteracting behaviors, such as changing posture and shielding the eyes from the light source, are often used to reduce glare [20]. Changing posture and work at a close distance could be seen as human adaptations to cope with glare and extensive near work, respectively, and the common ways of changing posture was to bend the head forward, probably to keep excessive light from going into the eyes [6,20]. Furthermore, Li et al. indicated that near work combined with long-term use of video display terminals was associated with dry eye disease [26]. Therefore, prolonged exposure to glare and near work may give rise to negative visual health, such as dry eye symptoms [8,9,27].

In the present study, 63.7% of the workers had eye fatigue, and the average experience at the job was 14 months. Our findings showed that experience at the job was a risk factor associated with eye fatigue. Our finding is consistent with Su et al. [28] showing that longer employment duration was associated with increased risk of eye fatigue among quality control workers at light bulb check stations. Regarding break time and eye fatigue, a previous study found that working for more than six hours in front of the computer had a negative impact on eye fatigue [29], and frequent short breaks are an effective way to decrease eye fatigue [30]. Cheu indicated that looking at an object away from the screen every half an hour is sufficient for preventing eye fatigue [31]. Similar to the above studies, we also found that break time was a protective factor of eye fatigue. In addition to experience at the job and break time, differences in illuminance between the work area (local high lighting in the microscope) [17] and the adjacent area (systemic lighting in the working station) may cause visual discomfort [15]. Although the present study did not find an association between eye fatigue and lighting problems, future studies may focus on measuring the differences in illuminance to evaluate the contribution to eye fatigue among cleanroom microscope workers.

There were several limitations that should be noted. First, this is a study in a single facility and the generalizability of this study requires further evaluation. Second, this cross-sectional study limits the inference of causal relationships and can only determine the association between lighting problems and eye symptoms. Third, other potential confounding variables for symptoms of dry eye and eye fatigue, such as smoking and work stress, are not included in the multivariable logistic regression model due to lack of information. Furthermore, occupational eye injuries (e.g., ocular trauma due to small objects or chemical agents) [32,33,34] and exposure to solar radiation [35,36] were not considered in the present study. For example, Gobba et al. found that the annual frequency of work-related eye injuries for the computer and electronic industry was 11.3‰ [34]. Fourth, the small sample size may compromise the identification of potential associations between eye symptoms and different lighting problems. Lastly, the study population were predominantly young female workers, and the findings of the present study may not be generalized to other populations. Further studies are needed to include more cleanroom microscope workers of different gender and age groups to increase the understanding of this important public health issue concerning the large number of electronic workers worldwide.

We found that the counteracting behaviors of needing to move closer to cope with lighting problems was positively associated with dry eye symptoms in the cleanroom microscope workers after adjusting for sex, age, and history of myopia. Workers with more experience at the job and having shorter break times were more prone to develop eye fatigue. The results call attention to the importance of creating sustainable working conditions [9], including proper lighting, ergonomic workplace design, and adequate break time for cleanroom microscope workers. Further research may focus on objective estimates of different lighting effects such as glare and illuminance to determine whether they have an independent influence on eye symptoms among cleanroom workers. Development of a program for the early detection and prevention of eye symptoms in the working environment is also warranted.

4. Su S.B., Lu C.W., Sheen J.W., Kuo S.C., Guo H.R. Tear secretion dysfunction among women workers engaged in light-on tests in the TFT-LCD industry. BMC Public Health.2006;6:303. doi: 10.1186/1471-2458-6-303. PubMed] [CrossRef]

5. Su S.B., Wang B.J., Tai C., Chang H.F., Guo H.R. Higher prevalence of dry symptoms in skin, eyes, nose and throat among workers in clean rooms with moderate humidity. J. Occup. Health.2009;51:364–369. doi: 10.1539/joh.Q8002. [PubMed] [CrossRef]

9. Toomingas A., Hagberg M., Heiden M., Richter H., Westergren K.E., Tornqvist E.W. Risk factors, incidence and persistence of symptoms from the eyes among professional computer users. Work.2014;47:291–301. [PubMed]

10. Smith J.A., Albeitz J., Begley C., Caffery B., Nichols K., Schaumberg D., Schein O. The epidemiology of dry eye disease: Report of the Epidemiology Subcommittee of the International Dry Eye WorkShop (2007) Ocul. Surf.2007;5:93–107. [PubMed]

12. Yen J.C., Hsu C.A., Li Y.C., Hsu M.H. The prevalence of dry eye syndrome’s and the likelihood to develop sjogren’s syndrome in taiwan: A population-based study. Int. J. Environ. Res. Public Health.2015;12:7647–7655. doi: 10.3390/ijerph120707647. PubMed] [CrossRef]

13. Bogdanici C.M., Sandulache D.E., Nechita C.A. Eyesight quality and computer vision syndrome. Rom. J. Ophthalmol.2017;61:112–116. doi: 10.22336/rjo.2017.21. PubMed] [CrossRef]

21. Cho H.A., Cheon J.J., Lee J.S., Kim S.Y., Chang S.S. Prevalence of Dry Eye Syndrome after a Three-Year Exposure to a Clean Room. Ann. Occup. Environ. Med.2014;26:26. doi: 10.1186/s40557-014-0026-z. PubMed] [CrossRef]

22. Oden N.L., Lilienfeld D.E., Lemp M.A., Nelson J.D., Ederer F. Sensitivity and specificity of a screening questionnaire for dry eye. Adv. Exp. Med. Biol.1998;438:807–820. [PubMed]

25. McMonnies C.W. Incomplete blinking: Exposure keratopathy, lid wiper epitheliopathy, dry eye, refractive surgery, and dry contact lenses. Contact Lens Anterior Eye.2007;30:37–51. doi: 10.1016/j.clae.2006.12.002. [PubMed] [CrossRef]

28. Su S.B., Sheen J.W., Kuo S.C., Guo H.R., Lu C. Survey of Ophthalmologic Symptoms of Light-On Test Workers in TFT-LCD Industry. Chin. J. Occup. Med.2004;11:107–115.

32. Yu T.S., Liu H., Hui K. A case-control study of eye injuries in the workplace in Hong Kong. Ophthalmology.2004;111:70–74. doi: 10.1016/j.ophtha.2003.05.018. [PubMed] [CrossRef]

34. Gobba F., Dall’Olio E., Modenese A., De Maria M., Campi L., Cavallini G.M. Work-related eye injuries: A relevant health problem. Main epidemiological data from a highly-industrialized area of northern Italy. Int. J. Environ. Res. Public Health.2017;14:604. doi: 10.3390/ijerph14060604. PubMed] [CrossRef]

Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is switched ON. Vertical ridges etched on the surface are smooth.

A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directlybacklight or reflector to produce images in color or monochrome.seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, except that arbitrary images are made from a matrix of small pixels, while other displays have larger elements. LCDs can either be normally on (positive) or off (negative), depending on the polarizer arrangement. For example, a character positive LCD with a backlight will have black lettering on a background that is the color of the backlight, and a character negative LCD will have a black background with the letters being of the same color as the backlight. Optical filters are added to white on blue LCDs to give them their characteristic appearance.

LCDs are used in a wide range of applications, including LCD televisions, computer monitors, instrument panels, aircraft cockpit displays, and indoor and outdoor signage. Small LCD screens are common in LCD projectors and portable consumer devices such as digital cameras, watches, calculators, and mobile telephones, including smartphones. LCD screens have replaced heavy, bulky and less energy-efficient cathode-ray tube (CRT) displays in nearly all applications. The phosphors used in CRTs make them vulnerable to image burn-in when a static image is displayed on a screen for a long time, e.g., the table frame for an airline flight schedule on an indoor sign. LCDs do not have this weakness, but are still susceptible to image persistence.

Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, often made of Indium-Tin oxide (ITO) and two polarizing filters (parallel and perpendicular polarizers), the axes of transmission of which are (in most of the cases) perpendicular to each other. Without the liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer. Before an electric field is applied, the orientation of the liquid-crystal molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic (TN) device, the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This induces the rotation of the polarization of the incident light, and the device appears gray. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.

The chemical formula of the liquid crystals used in LCDs may vary. Formulas may be patented.Sharp Corporation. The patent that covered that specific mixture expired.

Most color LCD systems use the same technique, with color filters used to generate red, green, and blue subpixels. The LCD color filters are made with a photolithography process on large glass sheets that are later glued with other glass sheets containing a TFT array, spacers and liquid crystal, creating several color LCDs that are then cut from one another and laminated with polarizer sheets. Red, green, blue and black photoresists (resists) are used. All resists contain a finely ground powdered pigment, with particles being just 40 nanometers across. The black resist is the first to be applied; this will create a black grid (known in the industry as a black matrix) that will separate red, green and blue subpixels from one another, increasing contrast ratios and preventing light from leaking from one subpixel onto other surrounding subpixels.Super-twisted nematic LCD, where the variable twist between tighter-spaced plates causes a varying double refraction birefringence, thus changing the hue.

LCD in a Texas Instruments calculator with top polarizer removed from device and placed on top, such that the top and bottom polarizers are perpendicular. As a result, the colors are inverted.

The optical effect of a TN device in the voltage-on state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low information content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage (the eye is much more sensitive to variations in the dark state than the bright state). As most of 2010-era LCDs are used in television sets, monitors and smartphones, they have high-resolution matrix arrays of pixels to display arbitrary images using backlighting with a dark background. When no image is displayed, different arrangements are used. For this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers. In many applications IPS LCDs have replaced TN LCDs, particularly in smartphones. Both the liquid crystal material and the alignment layer material contain ionic compounds. If an electric field of one particular polarity is applied for a long period of time, this ionic material is attracted to the surfaces and degrades the device performance. This is avoided either by applying an alternating current or by reversing the polarity of the electric field as the device is addressed (the response of the liquid crystal layer is identical, regardless of the polarity of the applied field).

Displays for a small number of individual digits or fixed symbols (as in digital watches and pocket calculators) can be implemented with independent electrodes for each segment.alphanumeric or variable graphics displays are usually implemented with pixels arranged as a matrix consisting of electrically connected rows on one side of the LC layer and columns on the other side, which makes it possible to address each pixel at the intersections. The general method of matrix addressing consists of sequentially addressing one side of the matrix, for example by selecting the rows one-by-one and applying the picture information on the other side at the columns row-by-row. For details on the various matrix addressing schemes see passive-matrix and active-matrix addressed LCDs.

LCDs are manufactured in cleanrooms borrowing techniques from semiconductor manufacturing and using large sheets of glass whose size has increased over time. Several displays are manufactured at the same time, and then cut from the sheet of glass, also known as the mother glass or LCD glass substrate. The increase in size allows more displays or larger displays to be made, just like with increasing wafer sizes in semiconductor manufacturing. The glass sizes are as follows:

Until Gen 8, manufacturers would not agree on a single mother glass size and as a result, different manufacturers would use slightly different glass sizes for the same generation. Some manufacturers have adopted Gen 8.6 mother glass sheets which are only slightly larger than Gen 8.5, allowing for more 50 and 58 inch LCDs to be made per mother glass, specially 58 inch LCDs, in which case 6 can be produced on a Gen 8.6 mother glass vs only 3 on a Gen 8.5 mother glass, significantly reducing waste.AGC Inc., Corning Inc., and Nippon Electric Glass.

In 1922, Georges Friedel described the structure and properties of liquid crystals and classified them in three types (nematics, smectics and cholesterics). In 1927, Vsevolod Frederiks devised the electrically switched light valve, called the Fréedericksz transition, the essential effect of all LCD technology. In 1936, the Marconi Wireless Telegraph company patented the first practical application of the technology, "The Liquid Crystal Light Valve". In 1962, the first major English language publication Molecular Structure and Properties of Liquid Crystals was published by Dr. George W. Gray.RCA found that liquid crystals had some interesting electro-optic characteristics and he realized an electro-optical effect by generating stripe-patterns in a thin layer of liquid crystal material by the application of a voltage. This effect is based on an electro-hydrodynamic instability forming what are now called "Williams domains" inside the liquid crystal.

In the late 1960s, pioneering work on liquid crystals was undertaken by the UK"s Royal Radar Establishment at Malvern, England. The team at RRE supported ongoing work by George William Gray and his team at the University of Hull who ultimately discovered the cyanobiphenyl liquid crystals, which had correct stability and temperature properties for application in LCDs.

The idea of a TFT-based liquid-crystal display (LCD) was conceived by Bernard Lechner of RCA Laboratories in 1968.dynamic scattering mode (DSM) LCD that used standard discrete MOSFETs.

On December 4, 1970, the twisted nematic field effect (TN) in liquid crystals was filed for patent by Hoffmann-LaRoche in Switzerland, (Swiss patent No. 532 261) with Wolfgang Helfrich and Martin Schadt (then working for the Central Research Laboratories) listed as inventors.Brown, Boveri & Cie, its joint venture partner at that time, which produced TN displays for wristwatches and other applications during the 1970s for the international markets including the Japanese electronics industry, which soon produced the first digital quartz wristwatches with TN-LCDs and numerous other products. James Fergason, while working with Sardari Arora and Alfred Saupe at Kent State University Liquid Crystal Institute, filed an identical patent in the United States on April 22, 1971.ILIXCO (now LXD Incorporated), produced LCDs based on the TN-effect, which soon superseded the poor-quality DSM types due to improvements of lower operating voltages and lower power consumption. Tetsuro Hama and Izuhiko Nishimura of Seiko received a US patent dated February 1971, for an electronic wristwatch incorporating a TN-LCD.

In 1972, the concept of the active-matrix thin-film transistor (TFT) liquid-crystal display panel was prototyped in the United States by T. Peter Brody"s team at Westinghouse, in Pittsburgh, Pennsylvania.Westinghouse Research Laboratories demonstrated the first thin-film-transistor liquid-crystal display (TFT LCD).high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays.active-matrix liquid-crystal display (AM LCD) in 1974, and then Brody coined the term "active matrix" in 1975.

In 1972 North American Rockwell Microelectronics Corp introduced the use of DSM LCDs for calculators for marketing by Lloyds Electronics Inc, though these required an internal light source for illumination.Sharp Corporation followed with DSM LCDs for pocket-sized calculators in 1973Seiko and its first 6-digit TN-LCD quartz wristwatch, and Casio"s "Casiotron". Color LCDs based on Guest-Host interaction were invented by a team at RCA in 1968.TFT LCDs similar to the prototypes developed by a Westinghouse team in 1972 were patented in 1976 by a team at Sharp consisting of Fumiaki Funada, Masataka Matsuura, and Tomio Wada,

In 1983, researchers at Brown, Boveri & Cie (BBC) Research Center, Switzerland, invented the passive matrix-addressed LCDs. H. Amstutz et al. were listed as inventors in the corresponding patent applications filed in Switzerland on July 7, 1983, and October 28, 1983. Patents were granted in Switzerland CH 665491, Europe EP 0131216,

The first color LCD televisions were developed as handheld televisions in Japan. In 1980, Hattori Seiko"s R&D group began development on color LCD pocket televisions.Seiko Epson released the first LCD television, the Epson TV Watch, a wristwatch equipped with a small active-matrix LCD television.dot matrix TN-LCD in 1983.Citizen Watch,TFT LCD.computer monitors and LCD televisions.3LCD projection technology in the 1980s, and licensed it for use in projectors in 1988.compact, full-color LCD projector.

In 1990, under different titles, inventors conceived electro optical effects as alternatives to twisted nematic field effect LCDs (TN- and STN- LCDs). One approach was to use interdigital electrodes on one glass substrate only to produce an electric field essentially parallel to the glass substrates.Germany by Guenter Baur et al. and patented in various countries.Hitachi work out various practical details of the IPS technology to interconnect the thin-film transistor array as a matrix and to avoid undesirable stray fields in between pixels.

Hitachi also improved the viewing angle dependence further by optimizing the shape of the electrodes (Super IPS). NEC and Hitachi become early manufacturers of active-matrix addressed LCDs based on the IPS technology. This is a milestone for implementing large-screen LCDs having acceptable visual performance for flat-panel computer monitors and television screens. In 1996, Samsung developed the optical patterning technique that enables multi-domain LCD. Multi-domain and In Plane Switching subsequently remain the dominant LCD designs through 2006.South Korea and Taiwan,

In 2007 the image quality of LCD televisions surpassed the image quality of cathode-ray-tube-based (CRT) TVs.LCD TVs were projected to account 50% of the 200 million TVs to be shipped globally in 2006, according to Displaybank.Toshiba announced 2560 × 1600 pixels on a 6.1-inch (155 mm) LCD panel, suitable for use in a tablet computer,

In 2016, Panasonic developed IPS LCDs with a contrast ratio of 1,000,000:1, rivaling OLEDs. This technology was later put into mass production as dual layer, dual panel or LMCL (Light Modulating Cell Layer) LCDs. The technology uses 2 liquid crystal layers instead of one, and may be used along with a mini-LED backlight and quantum dot sheets.

Since LCDs produce no light of their own, they require external light to produce a visible image.backlight. Active-matrix LCDs are almost always backlit.Transflective LCDs combine the features of a backlit transmissive display and a reflective display.

CCFL: The LCD panel is lit either by two cold cathode fluorescent lamps placed at opposite edges of the display or an array of parallel CCFLs behind larger displays. A diffuser (made of PMMA acrylic plastic, also known as a wave or light guide/guiding plateinverter to convert whatever DC voltage the device uses (usually 5 or 12 V) to ≈1000 V needed to light a CCFL.

EL-WLED: The LCD panel is lit by a row of white LEDs placed at one or more edges of the screen. A light diffuser (light guide plate, LGP) is then used to spread the light evenly across the whole display, similarly to edge-lit CCFL LCD backlights. The diffuser is made out of either PMMA plastic or special glass, PMMA is used in most cases because it is rugged, while special glass is used when the thickness of the LCD is of primary concern, because it doesn"t expand as much when heated or exposed to moisture, which allows LCDs to be just 5mm thick. Quantum dots may be placed on top of the diffuser as a quantum dot enhancement film (QDEF, in which case they need a layer to be protected from heat and humidity) or on the color filter of the LCD, replacing the resists that are normally used.

WLED array: The LCD panel is lit by a full array of white LEDs placed behind a diffuser behind the panel. LCDs that use this implementation will usually have the ability to dim or completely turn off the LEDs in the dark areas of the image being displayed, effectively increasing the contrast ratio of the display. The precision with which this can be done will depend on the number of dimming zones of the display. The more dimming zones, the more precise the dimming, with less obvious blooming artifacts which are visible as dark grey patches surrounded by the unlit areas of the LCD. As of 2012, this design gets most of its use from upscale, larger-screen LCD televisions.

RGB-LED array: Similar to the WLED array, except the panel is lit by a full array of RGB LEDs. While displays lit with white LEDs usually have a poorer color gamut than CCFL lit displays, panels lit with RGB LEDs have very wide color gamuts. This implementation is most popular on professional graphics editing LCDs. As of 2012, LCDs in this category usually cost more than $1000. As of 2016 the cost of this category has drastically reduced and such LCD televisions obtained same price levels as the former 28" (71 cm) CRT based categories.

Monochrome LEDs: such as red, green, yellow or blue LEDs are used in the small passive monochrome LCDs typically used in clocks, watches and small appliances.

Today, most LCD screens are being designed with an LED backlight instead of the traditional CCFL backlight, while that backlight is dynamically controlled with the video information (dynamic backlight control). The combination with the dynamic backlight control, invented by Philips researchers Douglas Stanton, Martinus Stroomer and Adrianus de Vaan, simultaneously increases the dynamic range of the display system (also marketed as HDR, high dynamic range television or FLAD, full-area local area dimming).

The LCD backlight systems are made highly efficient by applying optical films such as prismatic structure (prism sheet) to gain the light into the desired viewer directions and reflective polarizing films that recycle the polarized light that was formerly absorbed by the first polarizer of the LCD (invented by Philips researchers Adrianus de Vaan and Paulus Schaareman),

A pink elastomeric connector mating an LCD panel to circuit board traces, shown next to a centimeter-scale ruler. The conductive and insulating layers in the black stripe are very small.

A standard television receiver screen, a modern LCD panel, has over six million pixels, and they are all individually powered by a wire network embedded in the screen. The fine wires, or pathways, form a grid with vertical wires across the whole screen on one side of the screen and horizontal wires across the whole screen on the other side of the screen. To this grid each pixel has a positive connection on one side and a negative connection on the other side. So the total amount of wires needed for a 1080p display is 3 x 1920 going vertically and 1080 going horizontally for a total of 6840 wires horizontally and vertically. That"s three for red, green and blue and 1920 columns of pixels for each color for a total of 5760 wires going vertically and 1080 rows of wires going horizontally. For a panel that is 28.8 inches (73 centimeters) wide, that means a wire density of 200 wires per inch along the horizontal edge.

The LCD panel is powered by LCD drivers that are carefully matched up with the edge of the LCD panel at the factory level. The drivers may be installed using several methods, the most common of which are COG (Chip-On-Glass) and TAB (Tape-automated bonding) These same principles apply also for smartphone screens that are much smaller than TV screens.anisotropic conductive film or, for lower densities, elastomeric connectors.

Monochrome and later color passive-matrix LCDs were standard in most early laptops (although a few used plasma displaysGame Boyactive-matrix became standard on all laptops. The commercially unsuccessful Macintosh Portable (released in 1989) was one of the first to use an active-matrix display (though still monochrome). Passive-matrix LCDs are still used in the 2010s for applications less demanding than laptop computers and TVs, such as inexpensive calculators. In particular, these are used on portable devices where less information content needs to be displayed, lowest power consumption (no backlight) and low cost are desired or readability in direct sunlight is needed.

STN LCDs have to be continuously refreshed by alternating pulsed voltages of one polarity during one frame and pulses of opposite polarity during the next frame. Individual pixels are addressed by the corresponding row and column circuits. This type of display is called response times and poor contrast are typical of passive-matrix addressed LCDs with too many pixels and driven according to the "Alt & Pleshko" drive scheme. Welzen and de Vaan also invented a non RMS drive scheme enabling to drive STN displays with video rates and enabling to show smooth moving video images on an STN display.

Bistable LCDs do not require continuous refreshing. Rewriting is only required for picture information changes. In 1984 HA van Sprang and AJSM de Vaan invented an STN type display that could be operated in a bistable mode, enabling extremely high resolution images up to 4000 lines or more using only low voltages.

High-resolution color displays, such as modern LCD computer monitors and televisions, use an active-matrix structure. A matrix of thin-film transistors (TFTs) is added to the electrodes in contact with the LC layer. Each pixel has its own dedicated transistor, allowing each column line to access one pixel. When a row line is selected, all of the column lines are connected to a row of pixels and voltages corresponding to the picture information are driven onto all of the column lines. The row line is then deactivated and the next row line is selected. All of the row lines are selected in sequence during a refresh operation. Active-matrix addressed displays look brighter and sharper than passive-matrix addressed displays of the same size, and generally have quicker response times, producing much better images. Sharp produces bistable reflective LCDs with a 1-bit SRAM cell per pixel that only requires small amounts of power to maintain an image.

Segment LCDs can also have color by using Field Sequential Color (FSC LCD). This kind of displays have a high speed passive segment LCD panel with an RGB backlight. The backlight quickly changes color, making it appear white to the naked eye. The LCD panel is synchronized with the backlight. For example, to make a segment appear red, the segment is only turned ON when the backlight is red, and to make a segment appear magenta, the segment is turned ON when the backlight is blue, and it continues to be ON while the backlight becomes red, and it turns OFF when the backlight becomes green. To make a segment appear black, the segment is always turned ON. An FSC LCD divides a color image into 3 images (one Red, one Green and one Blue) and it displays them in order. Due to persistence of vision, the 3 monochromatic images appear as one color image. An FSC LCD needs an LCD panel with a refresh rate of 180 Hz, and the response time is reduced to just 5 milliseconds when compared with normal STN LCD panels which have a response time of 16 milliseconds.

Samsung introduced UFB (Ultra Fine & Bright) displays back in 2002, utilized the super-birefringent effect. It has the luminance, color gamut, and most of the contrast of a TFT-LCD, but only consumes as much power as an STN display, according to Samsung. It was being used in a variety of Samsung cellular-telephone models produced until late 2006, when Samsung stopped producing UFB displays. UFB displays were also used in certain models of LG mobile phones.

In-plane switching is an LCD technology that aligns the liquid crystals in a plane parallel to the glass substrates. In this method, the electrical field is applied through opposite electrodes on the same glass substrate, so that the liquid crystals can be reoriented (switched) essentially in the same plane, although fringe fields inhibit a homogeneous reorientation. This requires two transistors for each pixel instead of the single transistor needed for a standard thin-film transistor (TFT) display. The IPS technology is used in everything from televisions, computer monitors, and even wearable devices, especially almost all LCD smartphone panels are IPS/FFS mode. IPS displays belong to the LCD panel family screen types. The other two types are VA and TN. Before LG Enhanced IPS was introduced in 2001 by Hitachi as 17" monitor in Market, the additional transistors resulted in blocking more transmission area, thus requiring a brighter backlight and consuming more power, making this type of display less desirable for notebook computers. Panasonic Himeji G8.5 was using an enhanced version of IPS, also LGD in Korea, then currently the world biggest LCD panel manufacture BOE in China is also IPS/FFS mode TV panel.

In 2011, LG claimed the smartphone LG Optimus Black (IPS LCD (LCD NOVA)) has the brightness up to 700 nits, while the competitor has only IPS LCD with 518 nits and double an active-matrix OLED (AMOLED) display with 305 nits. LG also claimed the NOVA display to be 50 percent more efficient than regular LCDs and to consume only 50 percent of the power of AMOLED displays when producing white on screen.

This pixel-layout is found in S-IPS LCDs. A chevron shape is used to widen the viewing cone (range of viewing directions with good contrast and low color shift).

Vertical-alignment displays are a form of LCDs in which the liquid crystals naturally align vertically to the glass substrates. When no voltage is applied, the liquid crystals remain perpendicular to the substrate, creating a black display between crossed polarizers. When voltage is applied, the liquid crystals shift to a tilted position, allowing light to pass through and create a gray-scale display depending on the amount of tilt generated by the electric field. It has a deeper-black background, a higher contrast ratio, a wider viewing angle, and better image quality at extreme temperatures than traditional twisted-nematic displays.

Blue phase mode LCDs have been shown as engineering samples early in 2008, but they are not in mass-production. The physics of blue phase mode LCDs suggest that very short switching times (≈1 ms) can be achieved, so time sequential color control can possibly be realized and expensive color filters would be obsolete.

Some LCD panels have defective transistors, causing permanently lit or unlit pixels which are commonly referred to as stuck pixels or dead pixels respectively. Unlike integrated circuits (ICs), LCD panels with a few defective transistors are usually still usable. Manufacturers" policies for the acceptable number of defective pixels vary greatly. At one point, Samsung held a zero-tolerance policy for LCD monitors sold in Korea.ISO 13406-2 standard.

Dead pixel policies are often hotly debated between manufacturers and customers. To regulate the acceptability of defects and to protect the end user, ISO released the ISO 13406-2 standard,ISO 9241, specifically ISO-9241-302, 303, 305, 307:2008 pixel defects. However, not every LCD manufacturer conforms to the ISO standard and the ISO standard is quite often interpreted in different ways. LCD panels are more likely to have defects than most ICs due to their larger size. For example, a 300 mm SVGA LCD has 8 defects and a 150 mm wafer has only 3 defects. However, 134 of the 137 dies on the wafer will be acceptable, whereas rejection of the whole LCD panel would be a 0% yield. In recent years, quality control has been improved. An SVGA LCD panel with 4 defective pixels is usually considered defective and customers can request an exchange for a new one.

Some manufacturers, notably in South Korea where some of the largest LCD panel manufacturers, such as LG, are located, now have a zero-defective-pixel guarantee, which is an extra screening process which can then determine "A"- and "B"-grade panels.clouding (or less commonly mura), which describes the uneven patches of changes in luminance. It is most visible in dark or black areas of displayed scenes.

The zenithal bistable device (ZBD), developed by Qinetiq (formerly DERA), can retain an image without power. The crystals may exist in one of two stable orientations ("black" and "white") and power is only required to change the image. ZBD Displays is a spin-off company from QinetiQ who manufactured both grayscale and color ZBD devices. Kent Displays has also developed a "no-power" display that uses polymer stabilized cholesteric liquid crystal (ChLCD). In 2009 Kent demonstrated the use of a ChLCD to cover the entire surface of a mobile phone, allowing it to change colors, and keep that color even when power is removed.

In 2004, researchers at the University of Oxford demonstrated two new types of zero-power bistable LCDs based on Zenithal bistable techniques.e.g., BiNem technology, are based mainly on the surface properties and need specific weak anchoring materials.

Resolution The resolution of an LCD is expressed by the number of columns and rows of pixels (e.g., 1024×768). Each pixel is usually composed 3 sub-pixels, a red, a green, and a blue one. This had been one of the few features of LCD performance that remained uniform among different designs. However, there are newer designs that share sub-pixels among pixels and add Quattron which attempt to efficiently increase the perceived resolution of a display without increasing the actual resolution, to mixed results.

Spatial performance: For a computer monitor or some other display that is being viewed from a very close distance, resolution is often expressed in terms of dot pitch or pixels per inch, which is consistent with the printing industry. Display density varies per application, with televisions generally having a low density for long-distance viewing and portable devices having a high density for close-range detail. The Viewing Angle of an LCD may be important depending on the display and its usage, the limitations of certain display technologies mean the display only displays accurately at certain angles.

Temporal performance: the temporal resolution of an LCD is how well it can display changing images, or the accuracy and the number of times per second the display draws the data it is being given. LCD pixels do not flash on/off between frames, so LCD monitors exhibit no refresh-induced flicker no matter how low the refresh rate.

Brightness and contrast ratio: Contrast ratio is the ratio of the brightness of a full-on pixel to a full-off pixel. The LCD itself is only a light valve and does not generate light; the light comes from a backlight that is either fluorescent or a set of LEDs. Brightness is usually stated as the maximum light output of the LCD, which can vary greatly based on the transparency of the LCD and the brightness of the backlight. Brighter backlight allows stronger contrast and higher dynamic range (HDR displays are graded in peak luminance), but there is always a trade-off between brightness and power consumption.

Usually no refresh-rate flicker, because the LCD pixels hold their state between refreshes (which are usually done at 200 Hz or faster, regardless of the input refresh rate).

No theoretical resolution limit. When multiple LCD panels are used together to create a single canvas, each additional panel increases the total resolution of the display, which is commonly called stacked resolution.

LCDs can be made transparent and flexible, but they cannot emit light without a backlight like OLED and microLED, which are other technologies that can also be made flexible and transparent.

As an inherently digital device, the LCD can natively display digital data from a DVI or HDMI connection without requiring conversion