IPC Revision WG – Definition Project
EP
Rapporteur Proposal
Project: D082
Class/subclass:G02F
Date : 12/02/2016
Title - G02F
Devices or arrangements, the optical operation of which is modified by
changing the optical properties of the medium of the devices or
arrangements for the control of the intensity, colour, phase, polarisation or
direction of light, e.g. switching, gating, modulating or demodulating;
Techniques or procedures for the operation thereof;
Frequency-changing;
Non-linear optics;
Optical logic elements;
Optical analogue/digital converters
Definition statement
This subclass covers:

devices or arrangements for the control of light beams insofar their operation is based on
elements whose optical properties (e.g. refractive index, colour) are changed or controlled
by external physical parameters (e.g. electric field or current, magnetic field, sound or
mechanical vibrations, stress, thermal effects);

the following optic elements are therefore covered, the list being not exhaustive:
o thermo-optic elements
o electro-optic elements
o magneto-optic elements
o piezo-optic (photo-elastic) elements
o acousto-optic elements
o liquid crystal devices
o electrochromic elements
o electrophoretic elements

devices or arrangements in which the electric or magnetic field component of the light
beams influences the optical properties of the optical medium, i.e. non-linear optics;

control of light beams by electromagnetic waves, e.g. radio waves, or by electrons or other
elementary particles;

such functions of controlling light as switching, gating, modulating or demodulating,
focussing, deflecting, frequency-changing;

optical logic elements;

optical digital/analogue converters, insofar these converters are based on optic elements of
the kind described under first bullet above.
Relationship between large subject matter areas
Group G02B 26/00 covers optical devices or arrangements for controlling light using movable
or deformable elements, as opposed to G02F that covers devices or arrangements involving a
modification or control of the optical properties of the elements of said devices or
arrangements.
Group G05D 25/00 covers control of light in general, e.g. by using electric or mechanical
means, as opposed to G02F that covers devices or arrangements involving a modification or
control of the optical properties of the elements of said devices or arrangements.
Group G09F 9/35 covers indicating (display) arrangements in which characters are formed on
a support by combining individual liquid crystal elements (e.g. segment-type LCD's, or
matrix-type LCD's), as opposed to group G02F 1/13 that covers light control by individual
liquid crystal cells. Classification should be given in G09F 9/35 when the emphasis is on the
displaying aspects, and in the relevant subgroups of G02F 1/13 when the emphasis is on the
constructional aspects or optical properties of the liquid crystal cells involved.
References relevant to classification in this subclass
This subclass does not cover:
Lasers using stimulated Brillouin or Raman effect
H01S 3/30
Examples of places where the subject matter of this class is covered when specially adapted,
used for a particular purpose, or incorporated in a larger system:
Optical computing devices
G06E
Modulators for heads used in optical recording or reproducing
G11B 7/125
Indicating (display) arrangements in which characters are formed
on a support by combining individual liquid crystal elements,
e.g. segment-type LCD's, or matrix-type LCD's
G09F 9/35
Control of the emitted radiation in laser devices
H01S 3/10
H01S 5/06
Places in relation to which this subclass is residual:
Informative references
Attention is drawn to the following places, which may be of interest for search:
Liquid crystal materials
C09K 19/00
Optical transfer means between sensing member and indicating
or recording part in connection with measuring
G01D 5/26
Measuring characteristics of light, e.g. intensity, spectrum
G01J
Testing of optical apparatus
G01M 11/00
Optical devices, systems or arrangements per se
G02B
Control of light in general, e.g. by using electric means
G05D 25/00
Control arrangements of circuits for display devices other than
cathode-ray tube type, e.g. control circuits for LCD's or
electrochromic displays
G09G 3/00
Optical recording associated with non-optical reproducing, or
optical reproducing associated with non-optical recording
G11B 11/00
Digital static stores using optical elements
G11C 13/04
Semiconductor devices sensitive to light, e.g. photodetectors
H01L 31/00
Modulation of electromagnetic waves
H03C 7/00
Demodulation of electromagnetic waves, or transferring
modulation of electromagnetic waves from one carrier to another
H03D 9/00
Logic circuits using opto-electronic devices
H03K 19/14
Transmission systems employing light
H04B 10/00
Optical multiplex systems
H04J 14/00
Pictorial communication, e.g. television
H04N
Special rules of classification within this subclass
Glossary of terms
In this subclass, the following terms or expressions are used with the meaning indicated:
Synonyms and Keywords
In patent documents the following abbreviations are often used:
LCD
Liquid Crystal Display
PALC (display)
Plasma Addressed Liquid Crystal (display)
SEED
Self Electro-optic Effect Device
In patent documents the following expressions/words:
- "---", and "---"
are often used as synonyms.
In patent documents the expression/word "---" is often used instead of "---" which is used in
the classification scheme of this subclass (group.
In patent documents the expression/word "---" is often used with the meaning "---"