IPC 6 English version H04N !A-H04N 3/40

H04N-H04N00340

SECTION H– ELECTRICITY

H 04

ELECTRIC COMMUNICATION TECHNIQUE

H 04 N

PICTORIAL COMMUNICATION, e.g. TELEVISION (measuring, testing G 01; systems for autographic writing, e.g. writing telegraphy, which involve following an outline G 08; information storage based on relative movement between record carrier and transducer G 11 B; coding, decoding or code conversion, in general H 03 M; broadcast distribution or the recording of use made thereof H 04 H) [4]

Notes

(1)

This subclass covers:

–

transmission of pictures or their transient or permanent reproduction either locally or remotely, by methods involving both the following steps:

step (a):
the scanning of a picture, i.e. resolving the whole picture-containing area into individual picture-elements and the derivation of picture-representative electric signals related thereto, simultaneously or in sequence;

step (b):
the reproduction of the whole picture-containing area by the reproduction of individual picture-elements into which the picture is resolved by means of picture-representative electric signals derived therefrom, simultaneously or in sequence; [4]

–

(in group H 04 N 1/00) systems for the transmission or the reproduction of arbitrarily composed pictures or patterns in which the local light variations composing a picture are not subject to variation with time, e.g. documents (both written and printed), maps, charts, photographs (other than cinematograph films);

–

circuits specially designed for dealing with pictorial communication signals, e.g. television signals, as distinct from merely signals of a particular frequency range.

(2)

This subclass does not cover:

–

circuits or other parts of systems which form the subject of other subclasses, which are covered by the corresponding subclasses, e.g. H 03 C, H 03 F, H 03 J, H 04 B, H 04 H;

–

systems in which legible alphanumeric or like character forms are analysed according to step (a) of Note (1) to derive an electric signal from which the character is recognised by comparison with stored information, which are covered by subclass G 06 K;

–

systems for the direct photographic copying of an original picture in which an electric signal representative of the picture is derived according to the said step (a) and employed to modify the operation of the system, e.g. to control exposure, which are covered by class G 03;

–

systems for the reproduction according to step (b) of Note (1) of pictures comprising alphanumeric or like character forms but involving the production of the equivalent of a signal which would be derived according to the above-mentioned step (a), e.g. by cams, punched card or tape, coded control signal, or other means, which are covered by the subclass for the application, e.g. G 01 D, G 06 T, H 04 L;

–

systems for the reproduction according to the above-mentioned step (b) of pictures comprising alphanumeric or like character forms and involving the generation according to the above-mentioned step (a) of picture-representative electric signals from a pre-arranged assembly of such characters, or records thereof, forming an integral part of the systems, which are covered by the subclass for the application, e.g. B 41 B, G 06 K, subject to those applications which are covered by this subclass;

–

printing, duplication or marking processes, or materials therefor, which are covered by the relevant subclasses, e.g. B 41 C, B 41 J, B 41 M, G 03 C, G 03 F, G 03 G. [4]

(3)

In this subclass, the following expression is used with the meaning indicated:

–

"television systems" means those systems for the transmission and reproduction of arbitrarily composed pictures in which the local light variations composing a picture may change with time, e.g. natural "live" scenes, recordings of such scenes such as cinematograph films.

Note

In groups H 04 N 1/00 to H 04 N 17/00, it is desirable to add the indexing code of group H 04 N 101:00. The indexing code should be unlinked. [6]

Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof [3,4]

024

Details of scanning heads [3,4]

028

for picture-information pick-up [3,4]

029

Heads optically focused on only one picture element at a time [6]

with photodetectors arranged in a substantially linear array (scanning of linear arrays H 04 N 1/19) [6]

031

the photodetectors having a one-to-one and optically positive correspondence with the scanned picture elements, e.g. linear contact sensors [6]

032

for picture-information reproduction (engraving heads for the manufacture of printing formes B 41 C 1/02) [3,4]

034

using ink, e.g. ink-jet heads [5]

036

for optical reproduction [3,4]

Scanning arrangements (H 04 N 1/387 takes precedence) [4]

047

Detection, control or error compensation of scanning velocity or position (H 04 N 1/17 takes precedence) [6]

053

in main scanning direction, e.g. synchronisation of line start or picture elements in a line [6]

using cylindrical picture-bearing surfaces [4]

Mechanisms for mounting or holding the sheet around the drum [4]

using flat picture-bearing surfaces [4]

107

with manual scanning [6]

113

using oscillating or rotating mirrors [6]

using the sheet-feed movement as the slow scanning component (using multi-element arrays H 04 N 1/19) [4,6]

using a rotating endless belt carrying the scanning heads [4]

using a rotating helical element [4]

the scanning speed being dependent on content of picture [3,4]

(covered by H 04 N 1/04)

using multi-element arrays [6]

191

the array comprising a one-dimensional array [6]

192

Simultaneously scanning picture elements on one main scanning line [6]

193

using electrically scanned linear arrays [6]

195

the array comprising a two-dimensional array [6]

(transferred to H 04 N 1/203)

203

Simultaneous scanning of two or more separate pictures [6]

207

Simultaneous scanning of the original picture and the reproduced picture with a common scanning device [6]

Intermediate information storage (H 04 N 1/387, H 04 N 1/41 take precedence; information storage in general G 11) [4]

Reproducing arrangements (details of scanning heads H 04 N 1/024; scanning arrangements therefor H 04 N 1/04) [4]

involving production of a magnetic intermediate picture [4]

involving production of an electrostatic intermediate picture [4]

Mechanical arrangements for picture transmission, e.g. adaptation of clutches, gearing, gear transmissions [4]

Circuits or arrangements for control or supervision between transmitter and receiver

327

Initiating, continuing or ending a single-mode communication; Handshaking therefor [6]

333

Mode signalling or mode changing; Handshaking therefor [6]

for coin-freed systems

for synchronising or phasing transmitter and receiver

Circuits or arrangements for blanking or otherwise eliminating unwanted parts of pictures (H 04 N 1/387 takes precedence) [4]

387

Composing, repositioning or otherwise modifying originals (photoelectronic composing of characters B 41 B 19/00) [4]

393

Enlarging or reducing [4]

Picture signal circuits (H 04 N 1/387 takes precedence) [4]

401

Compensating positionally unequal response of the pick-up or reproducing head (H 04 N 1/403 takes precedence) [6]

403

Discrimination between the two tones in the picture signal of a two-tone original (shaping pulses by limiting or thresholding, in general H 03 K 5/08) [6]

405

Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels [6]

407

Control or modification of tonal gradation or of extreme levels, e.g. background level [6]

409

Edge or detail enhancement; Noise or error suppression [6]

Bandwidth or redundancy reduction (by scanning H 04 N 1/17) [3]

411

for the transmission or reproduction of two-tone pictures, e.g. black and white pictures [4]

413

Systems or arrangements allowing the picture to be reproduced without loss or modification of picture-information [4]

415

in which the picture-elements are subdivided or grouped into fixed one-dimensional or two-dimensional blocks [4]

417

using predictive or differential encoding [4]

419

in which encoding of the length of a succession of picture-elements of the same value along a scanning line is the only encoding step [4]

Systems for two-way working

Secrecy systems

Colour picture communication systems

Picture signal generators (for halftone screening H 04 N 1/52) [6]

Picture reproducers (for halftone screening H 04 N 1/52) [6]

Circuits or arrangements for halftone screening [6]

Conversion of colour picture signals to a plurality of signals some of which represent particular mixed colours, e.g. for textile printing [6]

Processing of colour picture signals (H 04 N 1/52 takes precedence) [6]

Edge or detail enhancement; Noise or error suppression, e.g. colour misregistration correction (H 04 N 1/62 takes precedence) [6]

Colour correction or control [6]

Retouching, i.e. modification of isolated colours only or in isolated picture areas only [6]

Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor [6]

Scanning details of television systems; Combination thereof with generation of supply voltages [4]

by optical-mechanical means only (H 04 N 3/36 takes precedence; optical scanning systems in general G 02 B 26/10) [2]

having a moving aperture

having a moving lens or other refractor

having a moving reflector

for electromagnetic radiation in the invisible region, e.g. infra-red [4]

by means not exclusively optical-mechanical (H 04 N 3/36 takes precedence; devices or arrangements for the electro-, magneto- or acousto-optical modulation or deflection of light beams G 02 F) [2]

by switched stationary formation of lamps, photocells, or light relays

by means of electrically scanned solid-state devices

for picture signal generation [3]

by deflecting electron beam in cathode-ray tube (producing sawtooth waveforms H 03 K 4/00)

Generation of supply voltages, in combination with electron beam deflecting [4]

185

Maintaining dc voltage constant (regulation of dc voltage in general G 05 F) [4]

Arrangements or assemblies in supply circuits for the purpose of withstanding high voltages [3]

195

(transferred to H 01 F 38/42)

Prevention of damage to cathode-ray tubes in event of failure of scanning

Circuits for controlling dimensions, shape or centering of picture on screen

223

Controlling dimensions (by maintaining the cathode-ray tube high voltage constant H 04 N 3/185) [4]

227

Centering [4]

Distortion correction, e.g. for pincushion distortion correction, S-correction [4]

233

using active elements [4]

237

using passive elements [4]

Blanking circuits

Modifications of scanning arrangements to improve focusing (focusing circuits in general H 01 J)

Circuits special to multi-standard receivers (circuitry of multi-standard receivers in general H 04 N 5/46) [3,4]

producing multiple scanning, i.e. using more than one spot at the same time

otherwise than with constant velocity or otherwise than in pattern formed by unidirectional, straight, substantially horizontal or vertical lines

Velocity varied in dependence upon picture information

Elemental scanning area oscillated rapidly in direction transverse to main scanning direction

Scanning of motion picture films, e.g. for telecine [2]

with continuously moving film [4]

with intermittently moving film [4]

H04N 5/00 - H04N 5/956