G
SECTION G — PHYSICS
  
INSTRUMENTS
 G02
OPTICS (making optical elements or apparatus B24B, B29D, C03, or other appropriate sub-class)
 G02B
OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS (G02F takes precedence; measuring-instruments, see the relevant sub-class of class G01, e.g. optical rangefinders G01C; testing of optical elements, systems, or apparatus G01M 11/00; spectacles G02C; sound lenses G10K 11/06; electron and ion "optics" H01J; X-ray "optics" H01J, H05G 1/00; optical elements structurally combined with electric discharge tubes H01J 5/16, H01J 29/89, H01J 37/22; microwave "optics" H01Q; combination of optical elements with television receivers H04N 5/72)
 G02B

Note(s)

In this sub-class: The following terms are used with the meanings indicated:

  1. "Simple lens or prism" denotes a single lens or prism.
  2. "Compound lens or prism" denotes an optical member, the constituents of which either are close together without air-space or (except in group G02B 11/00) are "in broken contact", i.e. with the air-space between the constituents having no essential optical influence
  3. "Objective" denotes a lens or an optical system designed to produce a real image of a real object.
  4. "Eyepiece" denotes a lens or an optical system designed to produce a virtual image for viewing by the eye or by another optical system.
  5. "Front" and "rear" are determined by looking from the more distant conjugate.
  6. "Optical" applies not only to visible light but also to ultra-violet and infra-red radiations.


 G02C
SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES (trial frames for opticians' use A61B 3/04; goggles or eyeshields not having the same features as spectacles A61F 9/00)
 G02C

Note(s)

This sub-class also includes contact lenses for the eyes, monocles, pince-nez, and lorgnettes.


 G02F
MODULATING OR DEMODULATING LIGHT; OPTICAL LOGICAL ELEMENTS; OPTICAL ANALOGUE-DIGITAL CONVERTERS