IPC 6 English version H03M-H03M 13/22

H03M-H03M01322

SECTION H– ELECTRICITY

H 03

BASIC ELECTRONIC CIRCUITRY

H 03 M

CODING; DECODING OR CODE CONVERSION, IN GENERAL (using fluidic means F 15 C 4/00; optical analogue/digital converters G 02 F 7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G 01 D, G 01 R, G 06 F, G 06 T, G 09 G, G 10 L, G 11 B, G 11 C, H 04 L, H 04 M, H 04 N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G 09 C) [4]

Analogue/digital conversion; Digital/analogue conversion (conversion of analogue values to or from differential modulation H 03 M 3/00) [4]

Reversible analogue/digital converters [4]

using stochastic techniques [4]

Continuously compensating for, or preventing, undesired influence of physical parameters (periodically H 03 M 1/10) [4]

of noise [4]

Calibration or testing [4]

Analogue/digital converters (H 03 M 1/02 to H 03 M 1/10 take precedence) [4]

Conversion in steps with each step involving the same or a different conversion means and delivering more than one bit [4]

with scale factor modification, i.e. by changing the amplification between the steps [4]

Automatic control for modifying the range of signals the converter can handle, e.g. gain ranging [4]

Increasing resolution using an n bit system to obtain n + m bits, e.g. by dithering [4]

pattern-reading type [4]

using relatively movable reader and disc or strip [4,6]

with weighted coding, i.e. the weight given to a digit depends on the position of the digit within the block or code word, e.g. there is a given radix and the weights are powers of this radix [4]

with non-weighted coding [4]

incremental [4]

using cathode-ray tubes [4]

Analogue value compared with reference values (H 03 M 1/48 takes precedence) [4]

simultaneously only, i.e. parallel type [4]

sequentially only, e.g. successive approximation type (converting more than one bit per step H 03 M 1/14) [4]

recirculation type [4]

Sequential comparisons in series-connected stages with no change in value of analogue signal [4]

Sequential comparisons in series-connected stages with change in value of analogue signal [4]

with digital/analogue converter for supplying reference values to converter [4]

Servo-type converters [4]

with intermediate conversion to time interval (H 03 M 1/64 takes precedence) [4]

Input signal integrated with linear return to datum [4]

Input signal sampled and held with linear return to datum [4]

Input signal compared with linear ramp [4]

Non-linear conversion [4]

with intermediate conversion to frequency of pulses [4]

Non-linear conversion [4]

with intermediate conversion to phase of sinusoidal signals [4]

Digital/analogue converters (H 03 M 1/02 to H 03 M 1/10 take precedence) [4]

with conversions of different sensitivity, i.e. one conversion relating to the more significant digital bits and another conversion to the less significant bits [4]

Automatic control for modifying converter range [4]

Sequential conversion in series-connected stages (H 03 M 1/68 takes precedence) [4]

Simultaneous conversion [4]

using switching tree [4]

using ladder network [4]

using weighted impedances (H 03 M 1/76 takes precedence) [4]

with intermediate conversion to time interval [4]

Non-linear conversion [4]

with intermediate conversion to frequency of pulses [4]

Non-linear conversion [4]

Conversion of analogue values to or from differential modulation [4]

Delta modulation, i.e. one-bit differential modulation [4]

Differential modulation with several bits [4]

Conversion of the form of the representation of individual digits [4]

Note

In groups H 03 M 5/02 to H 03 M 5/22, in the absence of an indication to the contrary, classification is made in the last appropriate place. [4]

Conversion to or from representation by pulses [4]

the pulses having two levels [4]

Code representation, e.g. transition, for a given bit cell depending only on the information in that bit cell [4]

Code representation by pulse width [4]

Code representation by pulse frequency [4]

Biphase level code, e.g. split phase code, Manchester code; Biphase space or mark code, e.g. double frequency code [4]

Code representation, e.g. transition, for a given bit cell depending on the information in one or more adjacent bit cells, e.g. delay modulation code, double density code [4]

the pulses having three levels [4]

two levels being symmetrical with respect to the third level, i.e. balanced bipolar ternary code [4]

the pulses having more than three levels [4]

Conversion to or from representation by sinusoidal signals [4]

Conversion of a code where information is represented by a given sequence or number of digits to a code where the same information is represented by a different sequence or number of digits [4]

Note

In groups H 03 M 7/02 to H 03 M 7/50, in the absence of an indication to the contrary, classification is made in the last appropriate place. [4]

Conversion to or from weighted codes, i.e. the weight given to a digit depending on the position of the digit within the block or code word [4]

the radix thereof being two [4]

the radix thereof being a positive integer different from two [4]

the radix being ten, i.e. pure decimal code [4]

the radix thereof being negative [4]

having two radices, e.g. binary-coded-decimal code [4]

Conversion to or from non-weighted codes [4]

Conversion to or from unit-distance codes, e.g. Gray code, reflected binary code [4]

Conversion to or from residue codes [4]

Conversion to or from n-out-of-m codes [4]

to or from one-out-of-m codes [4]

Conversion to or from floating-point codes [4]

Conversion to or from stochastic codes [4]

Programmable structures, i.e. where the code converter contains apparatus which is operator-changeable to modify the conversion process [4]

Compression (for image communication H 04 N); Expansion; Suppression of unnecessary data, e.g. redundancy reduction [4]

Conversion to or from delta modulation, i.e. one-bit differential modulation [4]

adaptive [4]

Conversion to or from differential modulation with several bits, i.e. the difference between successive samples being coded by more than one bit [4]

adaptive [4]

Conversion to or from variable length codes, e.g. Shannon-Fano code, Huffman code, Morse code [4]

using table look-up for the coding or decoding process, e.g. using read-only memory [4]

Suppression of irrelevant zeroes [4]

Conversion to or from run-length codes, i.e. by representing the number of consecutive digits, or groups of digits, of the same kind by a code word and a digit indicative of that kind [4]

alternating with other codes during the code conversion process, e.g. run-length coding being performed only as long as sufficiently long runs of digits of the same kind are present [4]

Conversion to or from non-linear codes, e.g. companding [4]

Parallel/series conversion or vice versa (digital stores in which the information is moved stepwise G 11 C 19/00) [4]

11/

Coding in connection with keyboards or like devices, i.e. coding of the position of operated keys (keyboard switch arrangements, structural association of coders and keyboards H 01 H 13/70, H 03 K 17/94) [4]

11/

Details [5]

11/

Coding of multifunction keys [5]

11/

by operating the multifunction key itself in different ways [5]

11/

by operating selected combinations of multifunction keys [5]

11/

by methods based on duration or pressure detection of keystrokes [5]

11/

by operating a key a selected number of consecutive times whereafter a separate enter key is used which marks the end of the series [5]

11/

by using additional keys, e.g. shift keys, which determine the function performed by the multifunction key [5]

11/

wherein the shift keys are operated after the operation of the multifunction keys [5]

11/

wherein the shift keys are operated before the operation of the multifunction keys [5]

11/

Dynamic coding, i.e. by key scanning (H 03 M 11/26 takes precedence) [5]

11/

Static coding (H 03 M 11/26 takes precedence) [5]

11/

using analogue means [5]

11/

using opto-electronic means [5]

13/

Coding, decoding or code conversion, for error detection or error correction (error detection or error correction for analogue/digital, digital/analogue or code conversion H 03 M 1/00 to H 03 M 11/00; specially adapted for digital computers G 06 F 11/08, for information storage based on relative movement between record carrier and transducer G 11 B, e.g. G 11 B 20/18, for static stores G 11 C) [4]

13/

using n-out-of-m codes [4]

13/

using convolutional codes [4]

13/

using interleaving techniques [4]