Sony said Tuesday that it's ready to begin installing its SXRD high-definition digital projectors in theaters across the country. The system boasts 8.8 million pixels, or four times the resolution of systems already in place in U.S. theaters. The 4K systems have recently been tested in 12 Landmark Theater screens. Now, Sony says, it is ready to begin turning out 100 projectors a month beginning in December. Sony said it had received commitments from four major studios to release films on digital files in the 4K format.