The top one is the CCFL LCD back light unit which is thick and it contains certain percenetage of mecury.
Second picture is Sony HCFL (Hot Cathode Florenscent Lamp) which is claimed to have less 40% power consumption than CCFL.
The Third one is the Edge Lit Back lit unit. It illustrates the design of the edge lit LED whcih has two high bright led column on the lift and right vertical Edges of the LED panel.
The Fourth picture is the Sony RGB LED matrix or direct RBG Back lit unit, each module consists of 4 LED, Red, Blue and Two Green, since the Green LED is not as efficient as RED and Blue, we have to use two pieces of Green LEDs.