Omron 2D CODE READER User Manual page 89

Appendix
Setting the Field of Vision and Working Distance
Refer to the following formula to calculate the field of vision and working distance.
(Code size: C) + 2 × (Cell size: S) < (Field of vision: A) < 121 × (Cell size: S)
Number of effective
pixels of camera
Code size
Symbol size
(Cell size)
Field of vision
Set an appropriate field of vision with workpiece positioning accuracy taken into
account.
Example: When the code size is 3 mm and the symbol size is 12 × 12
V400-F050/250/350
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User's Manual
640 (H) × 480 (V)
C (mm)
M × M
S (mm) = C/M
4 pixels/cell required
A margin for one cell is required.
Max.: A (mm) = S/4 × 480
Min.: A (mm) = C + S × 1 × 2
• Cell size: S = 3/12 = 0.25 mm
• Max. field of vision: 0.25/4 × 480 = 30 mm
• Min. field of vision: 3 + 0.25 × 1 × 2 = 3.5 mm
If the positioning accuracy is ±5 mm, the field of vision must be set between
13.5 mm or higher and below 30 mm.
S
C
A