×

Contrast enhancement structure for color cathode ray tube

  • US 4,663,562 A
  • Filed: 07/16/1984
  • Issued: 05/05/1987
  • Est. Priority Date: 07/16/1984
  • Status: Expired due to Fees
First Claim
Patent Images

1. In a CRT display with enhanced color contrast ratio, the combination comprising:

  • (a) CRT display having a plurality of color display elements,(b) Contrast ratio enhancing assembly means positioned in front of and affixed to the display for preferentially transmitting blue, green and red emissions and attenuating white background light, including;

    (1) directional filter means having a predetermined acceptance cone for blocking ambient white light outside of said acceptance cone and transmitting color emissions from said display and direct and reflected ambient white light within said cone, said directional filter means comprising two sets of spaced parallel light-blocking elements placed in generally orthogonal directions, wherein said sets are angularly offset from the scanning directions of the CRT to eliminate Moire patterns when viewing the CRT,(2) multi-notch filter means having higher transmittance in the blue, green, and red wave lengths whereby ambient white light is attenuated to a greater degree than said color emissions thereby enhancing the contrast ratio of the display.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×