Nowadays,
you can see a lot of people spending hours and hours together shopping for the perfect television which would occupy the center-stage of their respective
living rooms. With the ubiquitous presence of ever-confusing marketers of the
television-manufacturing companies, the decision is becoming all the more
difficult. So, let us understand the technologies before you splurge your hard-earned money on them.
Earlier,
you used to find televisions with only one kind of technology. They were called
‘CRT TVs’ (Cathode Ray Tube). With
the help of electron guns, coils and a fluorescent screen, the CRT TV was able
to produce a viewable image. Now, there were problems with this technology
- A number of components were used to manufacture the television which made the processes of production, repair and maintenance difficult
- The individual components were also bulky which made the television quite heavy
- Some of these televisions had a problem of ‘Image burn-in’ (Permanent discoloration of areas on electronic display) and a problem of ‘Image Loss’ at the boundaries of the display
- These televisions produced noticeable flicker at low refresh rates
- They consumed high power and generated a lot of heat
To
overcome the drawbacks of this technology, manufacturers started producing LCD
(Liquid Crystal Display) televisions. An LCD is a flat-panel display that makes
use of light modulating properties of liquid crystals. Now, these liquid
crystals do not emit light by themselves, so a backlighting source is required
in cases where there is higher power consumption. To understand this, you need
to take note that there are two kinds of LCDs: ‘Passive Matrix LCDs’ and ‘Active
Matrix LCDs’. In ‘Passive Matrix LCDs’ like ‘Alarm Clocks’ and
‘Calculators’ where the power consumption is less, a backlighting source is
usually not required. Contrast this with ‘Active Matrix LCDs’, where some sort
of backlighting mechanism is required. Now, this backlighting has been
traditionally achieved with a ‘Cold Cathode Fluorescent Lamp’ (CCFL) in an LCD
Television. So, the ‘CCFL backlit LCD’
television overcomes the problems of CRT in the following fashion
- They don’t use phosphor. So, the problem of ‘Image burn-in’ is eliminated
- They can be configured to run at high refresh rates. So, the problem of flicker is eliminated
- When compared to the CRT television, the components used are lighter in weight, so the heaviness of the television is reduced
- They consume lesser power and generate lesser heat while lighting the entire screen uniformly
- There is no ‘Image-Loss’ at the boundaries and the entire screen is viewable
Consequently,
manufacturers found out that they could improve upon these televisions too by
changing the backlighting mechanism. They found that they could bring about the
following changes
- Reduce the power consumption even further
- Reduce the thickness of the display even further
- Increase the image quality even further
- Increase the brightness of the display even further
- Reduce the weight of the display even further
The
manufacturers used LEDs (Light Emitting Diodes) as a backlighting source
instead of the conventional CCFL sources and were able to achieve all-the-above
stated objectives. So, this gave birth to the ‘LED backlit LCD’ televisions. Currently, if you go shopping for an
LCD television, you won’t find a true LED TV. The only things you will find are
‘LED backlit LCDs’. So, don’t expect to see a radically different picture
altogether as compared to a ‘CCFL backlit LCD’, albeit the images produced by
the ‘LED backlit LCD’ televisions are in fact much better. Even these
televisions can be further classified into 4 different categories. I'll explain these categories in the next post
Stay Tuned..!!
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