LG RT-48SZ40RB Service Manual page 17

10. White Uniformity Adjustment
(1) Required Test Equipments
1) Uniformity measuring equipment : Equipment which can
measure chromaticity in the whole screen
2) Set stand : 1EA
3) Remote controller for adjustment : 1EA
4) Circuit thing Jig for Adjustment (Except Driver Board Assy
of adjustment model)
--- Programmed Digital Board so that the VDP Test Pattern
can output white signal by 1level form 0 to 255 level.
(2) Equipment composition
Compose the equipment as Fig.2
(3) Preparation for Adjustment
1) Composite the equipment as shown Fig.2, and place the
set on fixation stand.
2) After inputting company channel 13, adjust colour uniformity
like Horizontal/ Vertical position adjustment of input signal
part adjustment by using remote control for adjustment.
3) After pressing IN_START key on remote control for
adjustment, select the adjustment mode 7050 Uniformity.
<Resister Explanation about uniformity adjustment>
1. RamCtrl : s/w saving uniformity write order (Do not adjust)
2. CSHP : Horizontal start point designation --- adjustable
3. CSVP : Vertical start point designation --- adjustable
4. CEHP : Horizontal END point designation --- adjustable
5. CEVP : Vertical END point 6.designation --- adjustable
6. Mode : uniformity mode select --- adjustable if need
*** 0 : 221point & 3level ---- default value
*** 1 : 221point & 4level
*** 2 : 825point & 3level
*** 3 : 825point & 4level
7. KHH : Upper 2byte of horizontal line correction coefficient --
Change according to CSHP, CEHP value.
8. KHL : Upper 2byte of vertical line correction coefficient --
Change according to CSHP, CEHP value.
** How to calculate KHH, KHL value
LCD panel size = 1280 x 720
Correction Point = 221 point
--> 17 horizontal points x 13 vertical points
(16 horizontal segments x 12 vertical points)
H Coefficient(KHH, KHL)
O
--> Calculation method (CEHP-CSHP=1280, Horizontal
segment value =16)
H coefficient = 1/(number of pixel intervals between setting in the horizontal
direction)
Hcoeff = 1/((1280/16)-1) = 0.012658227
16
hex (0.012658227 x 2 ) = 0 x 033D, Hcoeff (hex) = 0 x 033D + 1 = 0 x 33E
9. KVH : Upper 2byte of vertical line correction coefficient
-- Change according to CSVP, CEVP value.
10. KVL : Upper 2byte of vertical line correction coefficient
-- Change according to CSVP, CEVP value.
V Coefficient(KVH, KVL)
O
Calculation method (CEVP-CSVP=720, Vertical segment
value =12)
V coefficient = 1/(number of pixel intervals between setting in the vertical
direction)
Vcoeff = 1/((720/12)-1) = 0.016949152
hex (0.016949152 x 2
11. RL1H : Upper 9bit of MID2 brightness correction
coefficient in R MIN.
--- Change according to RMIN and RMID2 value.
12. RL1L : Lower 9bit of MID2 brightness correction coefficient
in R MIN.
--- Change according to RMIN and RMID2 value.
13. RL2H : Upper 9bit of MID1 brightness correction
coefficient in R MID2.
--- Change according to RMID2 and RMID1 value.
14. RL2L : Lower 9bit of MID1 brightness correction coefficient
in R MID2.
--- Change according to RMID2 and RMID1 value.
15. RL3H : Upper 9bit of MAX brightness correction coefficient
in R MID1.
--- Change according to RMID1 and RMAX value.
(use it while adjusting 4 coefficient)
16. RL3L : Lower 9bit of MAX brightness correction coefficient
in R MID1.
--- Change according to RMID1 and RMAX value.
(use it while adjusting 4 coefficient)
<L Coefficient Calculation Method>
Using 3coefficient Level
Assume that the value of R/G/B MIN, MID2,MID1 is 192, 448,
704.
R/G/B MIN = 192
R/G/B MID2 = 448
R/G/B MID1 = 704
L Coefficient(RL1H~BL3L)
O
- Calculation method (L1)
L1 coefficient = 1/(brightness level(MID2) - brightness level(MIN))
L1 coeff = 1/(448 - 192) = 1 / 256 =0.00390625
L1 coeff(hex) =hex(0.00393625 x 2
-> L1H(high 9bit) = b'000000010
- calculate L2, L3 same with L1
L2 coefficient =1/(brightness level(MID1) - brightness level(MID2)
L3 coefficient = 1/(brightness level(MAX) - brightness level(MID1)
17. GL1H : Upper 9bit of MID2 brightness correction coefficient
in G MIN.
--- Change according to GMIN and GMID2 value.
18. GL1L : Lower 9bit of MID2 brightness correction coefficient
in G MIN.
--- Change according to GMIN and GMID2 value.
19. GL2H : Upper 9bit of MID1 brightness correction coefficient
in G MID2.
--- Change according to GMID2 and GMID1 value.
20. GL2L : Lower 9bit of MID1 brightness correction coefficient
in G MID2.
--- Change according to GMID2 and GMID1 value.
21. GL3H : Upper 9bit of MAX brightness correction coefficient
in G MID1.
--- Change according to GMID1 and GMAX value.
(use it while adjusting 4 coefficient)
22. GL3L : Lower 9bit of MAX brightness correction coefficient
- 17 -
16 ) = 0 x 0456, Vcoeff (hex) = 0 x 0456 + 1 = 0 x 0457
18 ) =0 x 0400
L1L(low 9bit) = b'000000000
: case of 4 brightness Level