Improvement method of resolution of flat shadow mask for 64cm flat square CPT

摘要

The shadow mask is an important part of the CPT. An improvement method of resolution of flat shadow mask for 64cm Flat Square (FS) CPT is presented and new shadow mask for 64cm FS CPT has been designed. The horizontal pitch of new shadow mask is decreased to 0.57mm from original 0.71mm, but its strength and transmittancy are not affected. In the condition that new mould for making the shadow mask is not required and new CPT is manufactured on the original assemble-line and with process for ordinary 64cm FS CPT, the resolution of new CPT is increased to 730 lines from original 587 lines. The white uniformity and brightness characteristic etc. are equal to those of ordinary CPT. The better picture quality for VGA signals, VCD images and television signals is obtained.