Fitting Physical Screen Parameters to the Human Eye

The visual display is at present the main medium for human-computer interaction. To optimize display design, one must consider all three components of the humandisplay interface. First, one must understand the information that is to be conveyed to the human user. Second, one must consider the constraints that a particular display technology places on the transmission of the signal. Third, one must understand the properties of the human as the information receiver. This chapter will focus on data-entry video display terminals that are designed to transmit text. The information source can then be described as strings of alphanumeric characters. The chapter will also be limited to video displays based on the cathode-ray tube (CRT). This is the most common type of display a computer user will encounter today, although many new display technologies, such as liquid-crystal flat-panel displays, are on the horizon. Finally, this chapter will review those aspects of human spatial and temporal vision that influence our ability to interpret the information presented on video displays. The chapter is organized into two main sections that focus on the temporal and spatial aspects of digital displays. Each section, in turn, is separated into three subsections that review methods for characterizing the display, describe models of human image processing and discuss how this information can be used to solve applied problems in display design. The final section of the chapter describes how both the temporal and spatial display parameters define limits on the type of realistic motion one can simulate on the display.