3511656

Information

• Patent Grant
• 3511656

• References
• Source

• Patent Number

  3,511,656

• Date Filed

  Not available

• Date Issued

  Tuesday, May 12, 1970
  54 years ago

• CPC

  • G03F7/07 - used for diffusion transfer
  • B41M5/0253 - using a chemical colour-forming ink
  • G09B3/085 - with invisibly printed correct answer; the answer being rendered visible by special optical means
  • G03C8/44 - Integral units

• US Classifications

  • 430 - Radiation imagery chemistry: process, composition, or product thereof