1 Projection and imaging systems
1.1 Projectors and displays

Large-area imaging can be technically covered in two ways – in a projection and non-projection way.

Large-screen projection is the function of a data projector. Currently, LCD (Liquid Crystal Display) or DLP (Digital Light Processing) are used.

In the past, CRT (Cathode Ray Tube) projection was used. Projection systems can also include reflective LCDs and laser projection.

Non-projective large-scale imaging is done by so-called flat displays. Nowadays, LCD displays, or OLED (Organic Light Emitting Diode) are primarily used.

Plasma projections have been used in the past. Non-projective imaging systems can also include so-called LED (Light Emitting Diode) walls.

The basic feature of a data projector is to view images from a PC (Personal Computer) or NTB (NoTeBook / NeTBook), as well as viewing videos from other sources, such as TV, DVD (Digital Video Disc) or BD (Blu-ray Disc) etc.

The basic parameters are:

- Resolution - indicates the number of pixels in the image; the PC/NTB compatibility is important, strongly affecting image sharpness
- Luminous efficiency - they determine the image size or output light conditions/properties
- Weight - affects device mobility

Data projector resolution:

- 4:3 - older format, 1024x768 XGA (eXtended Graphics Array), 1400x1050 SXGA + (Super XGA +) and 1600x1200 UXGA (Ultra XGA)
- • 16:9 or 16:10 format - newer widescreen formats, 1280×800 WXGA (Wide XGA), 1920×1080 full HDTV (High Density TeleVision), 1920×1200 WUXGA (Wide UXGA), and 3840×2160 UHD (Ultra HD), often mistakenly referred to as 4K

Classification of data projectors:

- by weight - ultra light (up to 2 kg), personal (up to 4 kg), mobile (up to 6 kg) and conference (over 6 kg)
- by power - with LED light source (500 to 1500 ANSI lumens), with lamp or laser light source (3000 to 30000 ANSI lumens)
- by resolution - XGA, WXGA, FHD (1920 × 1080) and WUXGA (1920 × 1200), 2K and 4K digital cinema
- according to the technology used - LCD, DLP
- by destination - business, school, special applications (3D), for continuous operation (e.g. dispatching)