Panasonic tc-22lh1 technical guide Service Manual

 Figure 2A represents a basic LCD assembly, which is comprised of the following: A 
mirror (A), which is located on the rear of the assembly, provides for the reflection of 
light. A piece of glass (B) layered with a polarizing film is coated on the bottom side of 
the mirror, and a common electrode plane (C) made of indium-tin oxide is placed top. A 
common electrode plane covers the entire area of the LCD. Above that is the layer of a 
liquid crystal substance (D). This is followed by another piece of glass (E) with an 
electrode in the shape of a rectangle etched on the bottom side. Another polarizing film 
(F), which is layered on top, is right angle orientated to layer (B). A power source is 
connected to the electrode. When no current is supplied to the electrode (E), light 
entering through the front of the LCD will be reflected off the mirror and bounce right 
back out. When current produced by the power source is applied to the electrode (E), 
the liquid crystals between the common-plane electrode and the electrode shaped like a 
rectangle untwist and block the light in that area from passing through. The rectangle 

ithin LCD appears as a black area.  

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Figure 2a 

Most computer displays are lit with built-in fluorescent tubes above, beside and 
sometimes behind the LCD. A white diffusion panel behind the LCD redirects and 
scatters the light evenly to ensure a uniform display on its way through filters, liquid 
crystal layers and the electrode layers. By adding to the layer that contains the single 
electrode, more enhanced displays can be designed.  
 

Figure 2b 

 

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