LCD, TFT, LED displays: Touchscreen & coloured displays are hot products


By Sandhya Malhotra

Tuesday, May 18, 2010: In the display industry, liquid crystal display (LCD) and thin film transistor LCD (TFT-LCD) as components have gained footing in recent times, and have surpassed the CRT display technology to a considerable extent. LED as a component is also active displays as they emit light by themselves and convey the information to the user in the form of a number (seven segment), alphabet (alphanumeric) or picture (dotmatrix). In contrast, LCD and TFT displays require backlighting, which is mostly done with the help of LEDs, be it in mobile phones or new generation LED televisions. Large moving message displays or stadium displays use discrete LEDs placed in larger pitch arrays. Multi-coloured chips placed in these displays allow colour change through microprocessor controls.

These technological upgradations are largely driven by the environmental concerns that are driving the need for greener, efficient and advanced display systems with enhanced image quality and lower power consumption.

“LCD display as a component is a matured technology, whereas TFT is a relatively new technology and has not yet picked up due to its limited applications in electronics product in India,” says D Malakar, managing director, Deepakshi Display Devices, a Delhi based manufacturer of LCD display as a component.

Varied applications

LCD and TFT displays as components are used in a wide spectrum of electrical and consumer electronics—from factory automation, industrial machinery, equipment manufacturing, to office and home applications. Some of their common applications are clocks, watches, calculators, telephones, television sets, computer monitors, mobile phones, handheld video games, personal digital assistants, navigation systems, projectors, etc.

The most popular form of LED display is seven segment, which comes in various sizes such as 1.27 cm (0.56 inch), 0.762 cm (0.3 inch), 1.02 cm (0.4 inch) and 2.5 cm (1.0 inch). “Red colour LED is the most economical, brightest and sought after. They are applied in telephone booth displays, digital panel meters, weighing machines and temperature controllers. These applications account for 80 per cent of the consumption,” says K Vijay Kumar Gupta, managing director, Kwality Photonics Pvt Ltd, which has been manufacturing LED displays and power LEDs (700mA) for lighting, for the last 15 years.

Import driven segment

In India, LCD and TFT display markets are driven by importers and very few companies who manufacture LCD displays as components. Usually, LCD display components are being imported and then assembled here.

Kwality Photonics manufactures LEDs and caters mainly to high brightness and high reliability requirements. “Our customers generally demand inspection free quality of products and rely on our services rather than imports,” says Gupta.

P Hari Krishna, senior sales executive of Hyderabad based Lampex Electronics, claims to be the single largest LCD display manufacturer in India, since 1991, “We have more than two decades of manufacturing experiance and proud to state that we are the only exporter from India.” Other leading LCD manufacturers are Deepakshi Display Devices and Oriole Electronics. Leading traders in this domain include Behari Enterprises and Lappteck Marketing, who not only supply standard/monochrome LCD displays but are also trader in TFT displays. However, manufacturers are also offering customised solutions as per the needs of the customer.

What’s new and selling

The market offers three types of LCD displays that are used as components. These are monochrome, coloured and TFT. Monochrome LCD displays have been further classified into four categories such as Twisted Nematic (TN), Super Twisted Nematic (STN), Film Super Twisted Nematic (FSTN) and Color Super Twisted Nematic (CSTN). All of them vary in terms of viewing angle and temperature range, as per Nilesh Dedhia, director, Lappteck Marketing, who is the importer of powertrip, Apex, UTC, AUO, PVI, ChiMie brands of LCDs and TFTs display.

Generally, LCDs come in different forms like LCD panels, character LCDs, graphic LCDs and TFT-LCDs, varying in sizes ranging from 6 cm (2.4 inch) to 106.68 cm (42 inch). As buyers prefer LCD displays with lower power consumption, smaller sizes, sharper contrasts and larger viewing angles and with latest technology, configuration of these products change to suit their needs and to make the product, more user friendly real life display features.

“Coloured TFTs and touchscreen displays are the latest display products in the market. Recently, displays with coloured backlights have also been introduced to make LCDs aesthetically appealing,” informs Farheen Ali, director, Oriole Electronics. Her company manufactures LCD displays as a component and imports TFTs. “We have recently introduced 3.3 volt operational LCDs that consume less power compared to the traditional 5 volt LCDs,” adds Ali.

According to Sunil Khetwani, director, Behari Enterprises, a distributor of LCD displays for Winstar, Powertrip Tech and TFT displays for Prime View International, “Customers’ preferences are moving from standard LCDs to graphic LCDs and from STN to TFTs, as they have a better viewing angle and priced lower than coloured STN. Also, organic light emitting devices (OLED) are coming into prominence due to their brightness.”

According to Gupta, red, yellow and yellow-green displays, either made of obsolete gallium phosphide wafer, or aluminium gallium arsenide are also hot choice of the buyers as they give out uniform brightness across large batches. They are also made of the latest aluminium gallium indium phosphide, also known as high brightness LEDs.

Demand for customised displays

From emerging segments such as avionics, instrumentation, automobile, PDAs, energy, consumer durables and defence are opening new avenues for manufactures. Their focus has been shifted from telecommunications sector to non-conventional sectors, where their products are being used in various applications.

The automobile sector has good demand for displays and customised displays are picking up slowly in this sector. Traditionally, this sector has been import driven, dominated by Japanese automobile companies. However, this trend is changing with Indian vehicle manufacturers such as Mahindra & Mahindra and Tata creating demand for customised display solutions for electronic equipment of vehicles such as LCD display for control panels.

Malakar says, “Recently, our R&D team has developed a coloured LCD display for Indian automobile company, which is 75 per cent cheaper compared to TFT. We are expecting to rollout this product by next quarter, which is presently undergoing testing.”

Agreeing to Malakar, Krishna says, “As the automobile segment has started moving from mechanical speedometer to LCD meters, we can see other segments like consumer electronics also scaling up from traditional LED displays to more energy efficient LCD displays.”

Lampex customises 10-20 custom designs every month.

Commenting on customised display, Gupta says, “LED displays have found equilibrium with the closely competing LCD technology and have matured as products. The trend at present has shifted towards multi digit customised LED displays, thanks to market players aiming at large volumes in shorter product cycle time.”

Says Ali, “Customised LCDs and coloured TFTs are only marginally expensive but the additional value added to the product is tremendous.”

Technological innovations

While displays are being customised, technological innovations also take place as customers demand advance technology. Monochrome LCD displays and graphical displays have been innovated with high temperature range.

“Manufacturers of LCD displays are moving from standard LCDs to affordable coloured LCDs. Innovation has also taken place to compress more pixels in TFTs to have better resolution. For rough environmental conditions and temperatures, ratings have also been increased,” says Dedhia.

LED displays have also seen innovations. They are now found in SMD versions too. The chip on board (COB) versions are also manufactured for compact applications. Highly integrated multifunction indicator displays are also being made for DVD players, music systems, AC consoles and microwave ovens. These are used for their dynamic changing colours as they enhance aesthetics.

“Pointing out that not many new standards are likely to emerge from the LED display line,” Gupta says. Most of the research activities are directed towards lighting LEDs and In GaN materials. Research is also going on in the field of high efficiency emitter in green LED with 500-600 nm spectrum.

Service support

LCD is a key component in any electronics product. Failure of LCD means failure of the product. Therefore, timely service support for products using them is very critical. Importers like Lappteck Marketing offers one year warranty on its products. For faulty products, repair or replacement facility is also available. Malakar says, “We offer end-to-end support, from designing and conceptualising to technical support, to our customers.” Lampex offers complete turnkey solutions and complete support and warranty for LCD displays.

Oriole provides interfacing schematics and test code for all displays. “We conduct half day or one day training sessions for our customers to familiarise them with the products. We also provide test kits and evaluation boards or sometimes undertake entire LCD interfacing to hasten the customers development lifecycle,” adds Ali.

Challenges faced by buyers

“Consistence, quality, reliability, timely supplies and after sales support and service are some of the challenges faced by the buyers,” says Krishna.

Indian buyers seek the best products at lowest price. But apart from effective pricing, they need the right technical support and customised solution as per their requirement.

According to Gajandhra, proprietor, Rotex Electronix, TFT-LCDs and touchscreens are gaining popularity and aesthetics is playing a key role in their sales. Buyers of LCD components prefer sleeker screens in place of bulky cathode ray tube (CRT).

As Ali puts it, “There are many low cost displays available in the market. However, as the technology is changing fast, they become obsolete and their redesigning becomes extremely cumbersome as we lose their track in the market after a certain time. Buyers should try to avoid such products.”

Buying tips

LCD and TFT displays must be selected carefully depending on the kind of information to be displayed and the price of the product in which they are to be used. Apart from these, LED backlight brightness, technical support and long term availability of the display are other important factors that must be considered, informs Ali.

According to Malakar, LCD displays need several rounds of designing and redesigning, thus customers should buy products from creditable manufacturers. By buying from importers customers can only get price advantage but no technical service support.

“Quality of components, software capability, future upgradation, after sales support, technical expertise and track record of the traders should be checked. Price is not everything. Reliability and availability of high quality should be the most important factors for the buyers,” says Malakar.

The most desired parameters in LED displays are uniform brightness among all the digits within each batch. This can be achieved by specifying and procuring specially probed and sorted chips for intensity, wavelength and forward voltage, although these steps add to the cost. “This way Kwality predicts the brightness and calibrates it as per customers’ application requirements. Buyers of Chinese brands do not have this advantage,” says Gupta.

Finally, while buying displays, the most important decision is the selection of the right systems. “Often price becomes the deciding factor and the buyer ends up buying substandard products, concludes Ali.”

Different applications of LCD & TFT–LCD displays

• Landline phones, feature phones, pay phones

• PDAs and mobile phones

• Fax machines

• Test/measuring/processing instruments

• STD/PCO monitors, EPBAX systems

• POS terminals and PIT controllers

• Attendance machines

• PLCs, MMI, energy meters

• Weighing scales, data entry terminals

• CLI units, vending machines

• Petrol vending stations

• Electronic typewriters, calculators

• Remote controls

• Washing machines

• Refrigerators

• Railway engines

• Aircrafts

• Driving simulators

• Speedometers and dash boards in cars

Challenges faced by manufacturers

As LCD displays are the key components for any application, manufactures face challenges in procuring the components locally. D Malakar, managing director, Deepakshi Display Devices, says, “Manufacturing LCD modules is a tough and expensive affair in India. Components like LCD glass panels, gold plated PCBs and ICs, required for manufacturing LCD displays, are not available locally. Thus, we are forced to import components and assemble them into LCD displays to meet consumer demand.”

Manufacturing of LCD modules is also not a profitable business in India. There are issues like delayed payment cycles, maintenance of machines and overheads. “Despite all odds, we are making efforts to improve the technology and offer the latest and best service support systems to our customers,” says Malakar.

On the positive side, P Hari Krishna, senior sales executive, Lampex Electronics, says, “As part of our expansion plan, we would be commencing the indigenous manufacturing plant of LCD panels and TFTs in India in technical collaboration with LCD majors. Currently, we are importing major raw materials such as glass, polizers, ICs, etc, from Taiwan, Hong Kong and Japan. But at the same time, we have been getting our own proprietary ASICs of our LCD controllers.”

Electronics Bazaar, South Asia’s No.1 Electronics B2B magazine