NEC Display Solutions of America, Inc.
V311X/V311W Installation Guide
Ceiling Mounted and Desktop
Rev 1.0
www.necdisplay.com
V311X/V311W
Page 3 of 8
Formulas
The Projection Formulas use the image width for calculation. For proper projection placement, determine the image width
for the
desired screen size. Use the Screen Formulas below to calculate all screen dimensions. Plug in the width for “W” in
the Projection Formulas.
Refer to the diagrams and charts for popular screen sizes on page 2:
Definitions:
16:10 Screen Formulas:
W = Image Width
W = H x 16/10
H = Image Height (size)
H = W x 10/16
B = Vertical distance between lens center and screen center
Screen Diagonal = W x 18.868/16
C = Throw distance
D = Vertical distance between lens center and screen top
(screen bottom for desktop application)
Projection Formulas:
B
= 0.391W
C
(wide) = 1.55W
C
(tele)
= 1.70W
D
= 0.078W
α
(wide) =
tanˉ¹ (B/C(wide))
α
(tele) = tanˉ¹ (B/C(tele))
Distance Chart for popular 16:10 screens
Note:
For screen sizes not indicated on the
projection tables, use the formulas on page 1.
Diagonal Width(W) Height (H)
inches
inches
inches
inches
30
25
16
10
39
-
43
14.2
-
12.9
60
51
32
20
79
-
86
14.2
-
12.9
67
57
36
22
88
-
97
14.2
-
12.9
72
61
38
24
95
-
104
14.2
-
12.9
84
71
45
28
110
-
121
14.2
-
12.9
90
76
48
30
118
-
130
14.2
-
12.9
100
85
53
33
131
-
144
14.2
-
12.9
120
102
64
40
158
-
173
14.2
-
12.9
150
127
79
50
197
-
216
14.2
-
12.9
180
153
95
60
236
-
259
14.2
-
12.9
210
178
111
70
276
-
303
14.2
-
12.9
240
204
127
80
315
-
346
14.2
-
12.9
270
229
143
89
355
-
389
14.2
-
12.9
300
254
159
99
394
-
432
14.2
-
12.9
degrees
Screen Size (16:10)
4
inches
2
B
C
w ide - tele
inches
D
α
w ide - tele
4
5
6
6
7
8
10
12
14
16
18
20
