Data collection system and method that detect electronic device displays via fresnel patterns

A control subsystem determines based on the characteristics of light from a secondary illumination source reflected off optics of a data collection device whether a display screen of an electronic device (e.g., smartphone, smartwatch, tablet computer) are in a field of view of the data collection device, and switches operational modes accordingly. Thus, the control subsystem can employ a Fresnel pattern for such determination. The data collection device can operate in a diffuse reading mode, characterized by active illumination and/or relatively fast exposure times. The data collection device can operate in a reflective reading mode, characterized by a lack of active illumination and/or relatively slow exposure times. Characteristics can include the number of reflections versus a number of air-substrate interfaces and/or a relative intensity of the reflections produced by successive air-substrate interfaces in a path of the light.