LAS VEGAS (AP) — The race to make TVs larger and larger has created a colossal problem for manufacturers: As screens grow, picture quality worsens — unless the viewer moves farther away from the screen.

The issue is playing out in cozy dens and family rooms around the world. To get the full benefit of a large high-definition screen, viewers must move back from their sets. Because the ideal viewing distance is no closer than three times the height of your screen, or about one and a half times the diagonal length, big TVs have literally forced many families’ backs against the wall.

This year, TV makers are doing their best to give huge-screen fanatics more breathing room. New “ultrahigh-definition” sets were shown off Monday by LG Electronics Inc., Sharp Corp., Sony Corp. and Samsung Electronics Co. at the International CES gadget show in Las Vegas.