Akai LCT42Z7TAP, Service Manual

Page: 94 / 130

Product Specification
LC420WU1
Liquid Crystal Display
Note :
1. Contrast Ratio(CR) is defined mathematically as :
Surface Luminance with all white pixels
Contrast Ratio =
Surface Luminance with all black pixels
Measure Position : center 5point Max C/R (typical 800:1)
2. Surface Luminance(
L
WH
) is the luminance value measured at an approximate 50cm distance from
the center 1-point of LCD surface as all pixels displaying white. See FIG. 2 for more information.
3. The variation of surface luminance ,
δ
WHITE is defined as :
δ
WHITE(5P) = Maximum(L
on1
,L
on2
, L
on3
, L
on4
, L
on5
) / Minimum(L
on1
,L
on2
, L
on3
, L
on4
, L
on5
)
Where L
on1
to L
on5
are the luminance with all pixels displaying white at 5 locations .
For more information, see the FIG. 2.
4. Response time is defined as the required time for the transition from G(N) to G(M) (Rise Time, Tr
R
)
and from G(M) to G(N) (Decay Time, Tr
D
). For additional information see the FIG. 3. (N<M)
5. Viewing angle is the angle at which the contrast ratio is greater than 10. The angles are
determined for the horizontal or x axis and the vertical or y axis with respect to the z axis which
is normal to the LCD module surface. For more information, see the FIG. 4.
6. See Table 14 for gray scale specification
Table 14. GRAY SCALE SPECIFICATION
100
86.7
74.5
63.3
53.0
43.8
35.5
28.2
21.7
16.2
11.6
7.77
4.80
2.61
1.16
0.39
0.19
Luminance [%] (Typ.)
L239
L255
L159
L175
L191
L207
L111
L127
L143
L223
L47
L63
L79
L95
L31
L15
L0
Gray Level
92／128