Technical Specs

18
4. Limits of phosphor screen blemishes
(1) High-contrast blemishes
The following criteria is applied to high-contrast blemishes.
Allowable No. of blemishes
Allowable
Minimum
Separation(mm)
Blemish
Zone A Zone B Total
(Zone A & B)
Zone A Zone B A + B
A 1 trio 1 1 2 -----  20
B (1) 0 0 0   
(2) 1 2 2  20 20C
(3) 1 2 2 ---- 20 20
Green 3 4
Red 5 6D
1 dot
Blue 5 6
10 50 20 20
E In case of
A+C
   50 20 20
F In case of
A+C+D
   50 20 20
(1) 3 or more consecutive same color phosphor dots
(2) 2 consecutive same color phosphor dots
(3) 2 consecutive different color phosphor dots
(2) Medium-contrast blemishes
The following criteria is applied to medium-contrast blemishes.
Allowable maximum
number
Allowable minimum
separation(mm)Blemish
Zone A Zone B Zone A Zone A+B
3 consecutive dot 2 4 30 30
2 consecutive dot 3 7 20 20
1 dot ignore ignore  
Note) Minimum separation is 20 mm among any high and medium contrast blemishes
(excluding 1 dot medium contrast blemishes).
(3) Low-contrast blemishes
The following criteria is applied to low-contrast blemishes.
Blemishes
In zone A
Equivalent diameter of the total area of low-
contrast blemishes should be less than 13mm.
Extended blemishes
In both zones A and B
Equivalent diameter of the total area of low-
contrast blemishes should be less than 50mm.