The analysis inputs signal source:
Show the nature that believes a source according to place, projector can be divided for common video machine, number machine, graph machine 3 kinds. When showing composite signal only, can select common video engine; Want to show the signal that VGA outputs, can use the data projector under line frequency 60KHz, select digital engine; For resource conservation, accomplish proper, can decide to buy by actual umbriferous content why to plant the projector of class, be like shows software is given priority to with average teacher and student and word processing, criterion resolution of choose and buy is 800*600 (SVGA) if; asks a few taller, should choose XGA (1024*768) , SXGA(1280*1024) product has appeared on the market now, still will have UXGA(1600*1200) product later, when showing signal of high resolution graph, beard choice line frequency is in the digital machine of 60KHz above.
Confirm use pattern:
Cent of projector use means is being cast for desk type, condole top is being cast, desk type back is cast, condole top back is cast.
Be being cast is projector the same side in the audience; The back is cast is projector and audience are in respectively screen two end (need a back to cast act) .
Be like stationary use, optional choose condole carries means on the head.
If have enough space, choice back projects means whole result best, if the space is lesser, optional choose carries the means that sends reflection on the back.
Make clear indication environment:
The basis uses an environment (room size, illume circumstance) , affirmatory machine is corresponding index (be like: Brightness) .
Attention serves quality:
Projector value is higher, material of fittings, bad news (bulb) costlier also and it is more special article, accordingly, want to consider fixed use cost before buy, inspect the service level of the supplier beforehand, understanding serves content.