3700 Sagamore Parkway North . Lafayette, IN 47904 USA . Phone: (765) 423-1505
Lafayette Instrument Flicker Fusion
Table of Contents
Description
2
Overview
3
Specifications
3
Operating Instructions
4
Figure 1: Luminance Adjust
4
Figure 2: Mode Selection
4
Figure 3: Stimulus Selection
6
Figure 4: Sweep Rate Selection
6
Figure 5: Operate Window
6
Running with PsymLab Software
7
Photosensitivity Warning
7
Terms and Conditions
8
Description
The Lafayette Instrument Model 12021A Flicker Fusion provides the user with a variety of versatile controls
to perform accurate and timely measurements of CFF. Digital circuitry is used to provide extremely accurate
frequency generation from 1.0 Hz to 100.0 Hz in 0.1 Hz steps. The LCD display allows for exact and repeatable
frequency settings, while the serial port computer interface provides a means for test result storage or computer
control of the device. The user options include five modes of operation to cover virtually any test requirement:
Ascending Auto Frequency, Descending Auto Frequency, Continuous, Discrete, and Analog Control Mode.
Three automatic profiles (Automatic Method, Adaptive Method, and Self-Control Method) are available when
connected to a computer running Lafayette Instrument Company’s PsymLab software (available from Lafayette
Instrument Company). A serial-to-USB converter is required to connect with PsymLab.
The Lafayette Instrument viewing chamber has two lights, one for the left eye and one for the right eye. The
light compartments are completely separated, allowing for four stimulus combinations to occur: left eye only,
right eye only, left and right simultaneously, or left and right alternately.
The viewing chamber is constructed to control extraneous factors, which might distort CFF values. The white
Electroluminescent lamps produce even illumination over a ½” diameter viewing area. The stimuli are separated
by 2 ¾” center to center with a stimulus to eye distance of 15” and a viewing angle of 1.9
o
. The inside of the
viewing chamber is a dull black to minimize reflection.
The Model 12021A Flicker Fusion is a significant improvement over the previous Model 12023A Flicker Fusion.
The improved features include: frequency generation with only 0.05% error, defined sweep rate settings, 4
control push buttons and menu-driven LCD display for smaller packaging, RS-232C interface for computer
control and test result storage, and hypo-allergenic silicone viewing chamber mask for a comfortable fit on
the test subject’s face.
2