Definition:

LCD stands for liquid Crystal Display. It is a flat-panel display technology commonly used in laptop computers and flat-panel monitors. LCD uses liquid Crystal Display technology to show clear images. It is a thin display device that supports large resolutions and better picture quality. This technology has replaced the traditional cathode ray tube (CRT) monitors. The LCD is made of two sheets of a flexible polarizing material and a layer of liquid crystal solution between the two. LCD is also used in instrument panels, cell phones, digital cameras, TVs, tablets, and calculators.

History of Lcd Monitor

In 1888, Liquid crystals were first discovered in the cholesterol extracted from carrots by Austrian botanist and chemist Friedrich Reinitzer. At that time, Liquid Crystal was used in research and experimental works.

In 1936, Liquid Crystal was used in a practical application known as Liquid Crystal Light Valve, which is used in wireless telegraphy.

In 1962, a researcher of RCA, Richard Williams, generated some patterns in a thin layer of liquid crystal material by applying a voltage to it, which is known as electro-optical effects.

Finally, in the year 1964, LCD was invented.

The first modern LCD was produced in 1971 by International Liquid Crystal Company (ILIXCO) owner James Fergason. This LCD uses passive grid technology.

In 1972, the first active-matrix liquid crystal display panel was

produced in the USA by T. Peter Brody.

How LCD monitor work

LCD (liquid crystal display) monitors work by controlling the flow of electricity through a thin layer of liquid crystals to create images on the screen. Here are the main steps of how an LCD monitor works:

Backlight: A backlight, usually made of LEDs (light-emitting diodes), is located behind the LCD screen. The backlight emits light which passes through the screen.
Liquid crystals: The LCD screen is made up of a thin layer of liquid crystal material sandwiched between two sheets of glass. The liquid crystals are arranged in a grid pattern and can be electrically controlled to allow or block light passing through them.
Polarizers: Two polarizing filters are placed on the top and bottom of the LCD screen. The first filter polarizes the light from the backlight as it passes through the screen, and the second filter polarizes the light again as it exits the screen.
Color filters: Color filters are used to create different colors on the screen. These filters are arranged in a grid pattern and each sub-pixel is covered with either red, green or blue color filters.
Control circuitry: The control circuitry receives signals from the computer and converts them into instructions for the liquid crystals to create the images on the screen. By selectively applying electric charges to the liquid crystals, the control circuitry can change the orientation of the crystals and allow or block the passage of light.
Display images: The liquid crystals work together with the backlight to create the images on the screen. By adjusting the electric charge on each sub-pixel, the monitor can display different colors and shades.

LCD Display Types:

1) TN (Twisted Nematic):

TN stands for Twisted Nematic. It is the oldest of the LCD panel technologies. In TN displays, the liquid crystal molecules get controlled by voltage, changing their alignment. TN displays have low contrast ratios, viewing angles and colour contrasts.

2) In Panel Switching displays (IPS Panels):

IPS displays are considered the best LCD because they provide good image quality, higher viewing angles, vibrant colour precision & difference. Graphic designers primarily use these displays.

3) Vertical Alignment Panels (VA Panels):

It is seen as a medium quality between TN and IPS displays.

4) Advanced Fringe Field Switching (AFFS):

AFFS LCDs offer the best performance & a wide range of colour reproduction compared to IPS displays. This display is used in highly advanced and professional surroundings like the viable aeroplane cockpits.

4) TFT Dispaly Panel:

TFT stands for Thin Film Transistor. TFT is a liquid crystal display (LCD) type that uses thin-film transistor technology to improve qualities such as contrast and addressability. TFT technology means that an individual transistor drives each pixel, allowing for faster response times.
The benefit of thin-film transistor technology is the separate, tiny transistor for each pixel on display. Because each transistor is so small, the amount of charge needed to control it is also tiny. This allows the screen to refresh very quickly, as the image is re-painted or refreshed several times per second.

5) IPS Display panel:

IPS (In-Plane Switching) is an electronic screen display technology used in LCDs (liquid crystal displays). IPS changes the behavior of an LCD’s liquid crystals to produce a sharper, more accurate picture. This technique allows IPS displays to deliver a higher quality viewing experience than other screen types like TN or VA.
This technology is used everywhere, like televisions, computer monitors, and wearable devices. Today, IPS display panels deliver the best colors and viewing angles compared to other famous display planes, including VA (vertical alignment) and TN (twisted nematic).

What are the component LCD monitor:

LCD screens use several technologies to display an image. component are given below -----------

1) Polarized Glass:

An LCD cell is made up of two polarizing filters. One polarizing filter is located in front of the backlight and is horizontal in orientation. The other one is found just beneath the pixel in front and is vertical in orientation. LCD monitors feature two polarized glass sheets that function as filters that make it possible for users to view images on the screen. Polarizing filters are typically made of transparent crystals or glass substrates.

2) Liquid crystal molecules:

Liquid crystals are the heart of an LCD display. Liquid crystals are electrically charged molecules that can block or allow light to pass through. Liquid crystals are often sandwiched between the colour filters and the polarizers. They twist and straighten in response to electrical currents applied to them. The movement of liquid crystals controls whether polarized light will pass through the filters or not.

3) Transparent conductive materials:

For a screen to function properly and display crystal clear images without interruption, every pixel needs to be charged with an electric current. Transparent conductive screen layers made from materials like indium allow the electric currents to pass through easily.

3) Backlight:

The backlight is an illuminator for the entire LCD display device. Without a backlight, the LCD device remains darkened and hard to use. Backlights are installed directly behind the LCD panel to lighten up the display

Every computer screen has an LED backlight that produces white light. Flat panel displays feature LED backlights because they reduce overheating, have higher contrast ratios, more extensive brightness settings, and excellent overall colour reproduction.

Characteristics OF LCD monitor:

1) Power saving, no high temperature:

It is a low-power product that can be completely non-heated (mainly power and heat are present in the backlight tube or LED). At the same time, CRT monitors inevitably generate high temperatures due to imaging technology.

2) High display quality:

LCD has a high image quality and will never flicker, minimizing eye.

3) Thin body, saving space:

Compared with the more cumbersome CRT display, the liquid crystal display requires only one-third of the area of the former

4) NO electromagnetic radiation:

Many display products have been compared in dealing with radiation problems. But LCD has no radiation problem because it uses strict sealing technology to enclose a small number of electromagnetic waves from the drive circuit in the display.

5) The picture is soft and does not hurt the eyes:

Unlike CRT technology, the LCD screen does not flicker, which can reduce the damage of the monitor to the eyes. In LCD monitors, people can easily control the light and dark changes of the light to achieve the purpose of displaying images.

6) Low power consumption:

The traditional display

Advantages of LCD monitor :

There are several advantages of using an LCD (liquid crystal display) monitor, including:

Energy-efficient: LCD monitors are much more energy-efficient than older CRT (cathode ray tube) monitors, which can consume a lot of energy and generate a lot of heat. LCD monitors use less energy, generate less heat, and have a longer lifespan.
Lightweight and compact: LCD monitors are much thinner and lighter than CRT monitors, which makes them easier to transport and use in smaller spaces.
High resolution: LCD monitors can display high-resolution images with sharp and clear details. This is particularly useful for applications such as photo and video editing, as well as for gaming
Reduced glare and reflection: LCD monitors have a flat surface that reduces glare and reflection from light sources. This can help reduce eye strain and make it easier to work for long periods.
Environmentally friendly: LCD monitors are more environmentally friendly than CRT monitors because they use fewer hazardous materials and can be easily recycled.
Flexible mounting options: LCD monitors can be easily mounted on a wall or attached to an arm or stand, which can help to save desk space and provide more ergonomic positioning options.

Disadvantages of LCD monitor:

While there are many advantages to using LCD (liquid crystal display) monitors, there are also a few disadvantages to consider:

Limited viewing angles: LCD monitors have a limited viewing angle, meaning that the image may appear distorted or washed out when viewed from an angle.
Contrast and color issues: Some LCD monitors may have difficulty producing deep blacks, resulting in reduced contrast. Additionally, some monitors may have color accuracy issues, which can affect the quality of images and videos.
Response time: LCD monitors have a response time, which is the time it takes for a pixel to change from one color to another. Some monitors may have slower response times, which can result in motion blur or ghosting when watching videos or playing games.
Backlight bleeding: Some LCD monitors may suffer from backlight bleeding, which is when light from the backlight bleeds through the edges of the screen, causing uneven lighting and reducing image quality.
Higher cost: LCD monitors can be more expensive than CRT monitors or other types of displays, especially for models with high resolution or advanced features.
Environmental issues: While LCD monitors are more environmentally friendly than CRT monitors, they still require energy to manufacture and can contribute to electronic waste when they are discarded.