The PJ WX4240 supports a maximum resolution of 1280 x 1024 (SXGA). That's over four times the resolution of a 640 x 480 (VGA) projector, which is the most frequently found resolution supported by projectors that have been on the market for a comparable time to the PJ WX4240. Multimedia projectors that were released around the same time as the PJ WX4240 graphics resolutions range from 640 x 480 (VGA) (worst) to 1920 x 1200 (WUXGA) (best).
Other multimedia projectors that support a resolution of 1024 x 768 (XGA)|1280 x 1024 (SXGA)|1280 x 800 (WXGA)|1600 x 1200 (UXGA)|640 x 480 (VGA)|800 x 600 (SVGA) currently available that you might also want to look at include cheaper projectors such as the PJ WX3340, the PJ X3340, or the PJ X3340 all from Ricoh.
Projectors with a higher resolution that might also be worth considering include the Ricoh PJ X4240N (1024 x 768 (XGA)|1280 x 1024 (SXGA)|1280 x 800 (WXGA)|1600 x 1200 (UXGA)|640 x 480 (VGA)|800 x 600 (SVGA)).