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2-2 Optical system (Layout Drawing)
2-2-1 Position of Chart Projector
The single tube projector must be installed at the same distance from
the screen as the patient.
[Fig. 3 Installation without mirrors]
Install chart projector at desired position within 2.5~8m (8~26 feet).
Set the projection angle of chart processor based on Screen.
Project 0.05(20/400, 6/120) “C” chart onto the screen.
Adjust it for a bright clear image using the focusing wheel.
2-2-2 How to obtain correct Letter Size and focus (Zooming Type only)
Install chart projector at desired position of 2.5~8m (8~26 feet)
Measure the distance from patient to screen
Refer to the test scale shown in the Appendix A
Have someone hold the test scale at the screen
Project the 20/400(6/120, 0.05) alphabet “C”
Adjust the position of the projector forward or backward and turn the focusing
wheel until “C” is brought in sharp focus within the respective distance scale
