JVC LT-26C31BJE Service Manual page 8

2.2 TECHNICAL INFORMATION
2.2.1 LCD PANEL
This unit uses the flat type panel LCD (Liquid Crystal Display) panel that occupies as little space as possible, instead of the
conventional CRT (Cathode Ray Tube), as a display unit.
2.2.1.1 STRUCTURE
The LCD panel of the unit is constructed with the metal chassis that surrounds the panel unit and supports the LCD panel part and
the backlight part to protect them.
The colour filter glass and the TFT glass (thin film transistor) are inserted between the front polarizing filter and the rear polarizing
filter. Liquid crystals are inserted between the colour filter glass and the TFT glass. Since the gap between the two glasses is only a
few µm, a spacer (bead) is inserted in the gap to retain the gap.
The backlight unit is placed behind the LCD panel. Since liquid crystals themselves do not emit light, the backlight as an external light
source emits light to the LCD panel from behind through the diffuser.
Circuit boards for controlling the LCD panel and the backlight are attached around the back part of the LCD panel unit.
Since the unit has the two polarizing filter that are at right angles to each other, the unit adopts "normally black" mode, where light
does not pass through the polarizing filter and the screen is black when no voltage is applied to the liquid crystals.
2.2.1.2 SPECIFICATIONS
The following table shows the specifications of this unit.
Item
Maximum dimensions ( W × H × D )
Weight
Effective screen size
Aspect ratio
Drive device/ system
Resolution
Pixel pitch (pixel size)
Displayed colour
Brightness
Contrast ratio
Response time
View angle
2.2.1.3 PIXEL FAULT
There are three pixel faults - bright fault , dark fault and flicker fault - that are respectively defined as follows.
(1) BRIGHT FAULT
In this pixel fault, a cell that should not light originally is lighting on and off.
For checking this pixel fault, input ALL BLACK SCREEN and find out the cell that is lighting on and off.
(2) DARK FAULT
In this pixel fault, a cell that should light originally is not lighting or lighting with the brightness twice as brighter as originally lighting.
For checking this pixel fault, input 100% of each R/G/B colour and find out the cell that is not lighting.
(3) FLICKER FAULT
In the pixel fault, a cell that should light originally or not light originally is flashing on and off.
For checking this pixel fault, input ALL BLACK SCREEN signal or 100% of each RGB colour and find out the cell that is flashing on
and off.
1-8 (No.YA014)
Lower frame
Upper frame
Top chassis
Panel ASSY
Diffuser (including board)
Fig.1 Structure of the LCD panel unit
62.7cm × 38.9cm × 4.9cm
8.0kg
Diagonal : 66cm (H:33.9cm × V : 56.6cm)
15:9
a-Si-TFT, active matrix system
Horizontally 1280 × Vertically 768 × RGB <W-XGA>
Horizontally:0.4425mm, Vertically:0.4425mm
16777216 colours
2
450cd/m
500:1
16.7ms
Vertically 170°, horizontally 170°
Diffuser supporter
Inverter shield cover
Source board
Sield case
Inverter board
Lamp supporter
Reflection plate
Specifications Remarks
26V type
2949120 dots in total
256 colours for R, G, and B
2
500cd/m at maximum