Crt Limits Of Screen And Faceplate Blemish; Crt Face Plate Defect - Mitsubishi Diamond Pro 750SB Service Manual

6. CRT Limits of Screen and Faceplate Blemish

6.1 CRT Face plate defect

6.1.1 Inspection condition
1) In the operating condition, observe the defect on the screen under the following condition:
9300 K (x=0.283, y=0.297) white raster or the element monochrome raster which its brightness is 34 cd/m
(10 ft-L) on the screen center surrounding light is about 10 Lux.
2) In the non-operating condition, observe the defect of the screen under light of about 200 Lux, measured at
the faceplate.
3) Inspection shall be made more than 45cm away from the screen.
4) Observe the screen on white raster and each monochrome color of red, green and blue.
6.1.2 Division of zone
A screen is divided into following 2 zones.
Zone A: Area inside the rectangle that its size measures H: 300mm, V: 225mm in the center of screen.
Zone B: Area outside the above rectangle.
6.1.3 Limits
1) CRT face defect
a. Distance (Minimum distance)
b. Average diameter
Turn of (a + b) / 2
c. Limit
Dark spot, Blocked aperture
Average diameter (mm)
0.51 ~
0.31 ~ 0.50
0.15 ~ 0.30
Discoloration, Stain, Missing phosphor, etc.
Average diameter (mm)
0.51 ~ 0.75
00.15 ~ 0.50
Note 1: No missing spot large than specified are allowed in Zone A.
Note 2:The spec applies to each color.
(a: length, b: width)
A
0
0
6 (note 1)
A
0
2
B A + B
0 0
0 0
6 (note 1) 10 (note 1)
B A + B
1 -
3 -
5-25
a
b
Minimum distance
-
-
10mm
Minimum distance
20mm
20mm
2