Frequently Asked Questions

what’s a TFT-LCD?
TFT-LCD, which stands for thin-film-transistor liquid display, consists of glass substrates on rock bottom , a color filter substrate on the highest and liquid in between. The special properties of the liquid are manipulated to make images. These technology intensive products represent subsequent generation in displays. they’re flat and thin, easy to hold around and consume less power. ask the Technology section for details.

What is life time of LCD and backlight?
Very long, in most cases, providing the operating condition is stable, the LCD may operate for years. only for reference, below is typical life time for displays, >50,000hours

What is thickness of LCD and glasses?
Thickness of LCD depends on stacking height. Typical standard structure of LCD consists of: Description Top Polarizer with thickness of roughly 0.08mm~0.15mm Top Glass with thickness between 0.5mm and 1.1mm typical Liquid crystal cell with thickness negligible (4 to 9 micron) Bottom Glass with thickness between 0.5mm and 1.1 mm typical Bottom polarizer with or without reflector

what percentage sorts of display methods are available?
Basically there are three sorts of display methods: Segment type (7segments, 14, segments, 16 segments) Dot Matrix type. Graphical type.

How can we define the viewing direction?
We use four different viewing directions for LCDs: 3 o’clock, 6 o’clock, 9 o’clock and 12 o’clock viewing means you check out the LCD from its left side, 6 o’clock means you check out the LCD from rock bottom …and so on. 6’clock is that the commonest viewing direction. samples of 6 o’clock viewing are calculators and notebooks.

How do i do know what sort of LCD to use for our product?
That will really depends on variety of things including multiplex driving scheme, temperature, voltage/power, artwork design, contrast requirements and price budget. The main categories which we could provide by our own facility are: TN, HTN, STN, and also special product like cholesteric bi-stable displays and single polarizer high contrast reflective TN/HTN display.

What sorts of connectors are utilized in LCDs?
The connectors used for LCDs are elastomeric (rubber connector), pin and versatile cable.

what percentage sorts of viewing modes are utilized in LCD glass?
There are three sorts of basic modes: “Reflective”, “Trans-missive”, and “Trans-flective”. ” Tran-missive” and “Trans-flective” are used with an LED, EL, or CCFL backlight.

Is temperature a matter of concern in LCDs?
Yes, since the LCDs are widely used, a number of the applications are going to be in extreme weather where a good temperature range is required. Normally the wide temperature range for a TN type LCD is -30 ~ 75C (operation Temp.) and -30 ~ 70C (storage temp.)

What is viewing angle?
A. LCD utilize physical phenomena of liquid know as birefrigerance (which describe its properties of getting two different index of refraction counting on orientation) to make the sunshine blocking and spending effect. due to this, normally, the simplest viewing cone is best at a particular direction which is know as viewing angle. It is commonly specify by: 12:00, 6:00, 3:00 and 9:00 except in special situation like automotive which can require nonstandard direction.

What other factors may affect lifetime of LCD?
Two factors: me moisture exposure will cause sodium migration within the glass which can contaminate the liquid , often end in increa Heat – because the polarizer is formed of plastic (often Mylar based material), heat will de-stress the polarizer which can eliminate the polarizing effect. Special iodine type polarizer could also be necessary to use at cost of lower polarizing efficiency (thus darker and diminishing contrast). this is often trade off one must take when specify the merchandise . The stop is generally at around +85 degree Centigrade . material which act as a barrier layer. the most purpose is to scale back chance of ionic contamination which can deteriorate the display performance and shorten its life time. fairly often , silica is employed for this purpose.

How does LCD gets driven?
LCD is driven by AC (alternating current), it’s best to use standard LCD driver IC to get as this may simplified your development time. Alternatively, for easy TN segment drive, most MCU may emulate the AC current but would wish tons of background skills . for instance , simple TN segment drive would require as low as 40Hz to as high as 120 Hz. counting on the operating environment like temperature and would affect the contrast of the display. Some experiment could also be got to find the optimum operating condition.

What interconnection technology is out there to attach LCD to peripherals?
Commonly available through us are pin connection (with pitch commonly at 2.54mm, 1.8mm standard) heat seal connection FPC (flexible PC) zebra or sometimes know as elastomer interconnector

Why does my LCD turns dark when left under the sun and is there any problems with the display?
For most cases, both TN, HTN and STN utilize the phase referred to as nematic for display purpose. Within this phase, the liquid features a “rod shape” exists within the answer which has fast response and has excellent electro-optic properties. This phase, however, only exists within a limited temperature range. the upper end of this temperature range is understood as clearing point, above which, the liquid lost its birefrigerance properties and can’t bend the sunshine path anymore. Thus the polarizer will then be the sole factor which affect incoming and out coming light. When the LCD is cooled right down to below its clearing point, the display should be working again. The temperature for the clearing point varies greatly from material to material and you ought to contact our engineers regarding what you’ve got . Normally a secure margin should be wont to avoid clearing point when designing the display.

Share this post