Answer: A. Lamp bead packaging method.
Answer analysis: When discussing the factors that affect the viewing angle of LED display screens, we need to analyze from the physical structure and optical characteristics of LED display screens.
A. Lamp bead packaging method: The packaging method of LED lamp beads directly affects its luminous angle and light distribution. Different packaging methods will lead to differences in the distribution of light in space, which in turn affects the viewing angle of the display screen. For example, lamp beads with wide-angle packaging can provide a larger viewing angle, allowing viewers to clearly see the display content at different angles.
B. Mask brim: This option is obviously not directly related to the technical parameters or structure of the LED display screen. Mask brim is an item used to block sunlight or protect the face in daily life, and has nothing to do with the viewing angle of the LED display screen.
C. Lamp bead spacing: Although the lamp bead spacing affects the resolution and clarity of the display screen, it does not directly affect the viewing angle. The viewing angle is mainly determined by the luminous characteristics and packaging method of the lamp beads, rather than the physical distance between the lamp beads.
D. Display brightness: Display brightness is an important parameter of the display screen, but it mainly affects the visibility and clarity of the display screen under different lighting conditions, rather than the viewing angle. A high-brightness display screen can also maintain a good display effect in a strong light environment, but it does not change its viewing angle.
In summary, the main factor affecting the viewing angle of the LED display screen is the packaging method of the lamp beads. This is because the packaging method determines the diffusion angle and distribution characteristics of the lamp bead light, which directly affects the effect of the audience viewing the display screen at different angles.
Therefore, the correct answer is A. Lamp bead packaging method.