F-Term-List

H04M1/00-1/00@Z;1/24-1/253;1/58-1/62;1/66-1/82

AA00
USE

AA01

AA02

AA03

AA04

AA05

AA06

AA07

AA08

AA09

AA10

. Rotary dial telephones

. Key telephones

. Key telephones, often called button telephones

. Public telephones

. Subsidized telephones

. Emergency telephones

. Conference telephones

. Home telephones

. Intercom telephones

. Digital telephones

AA11

AA12

AA13

AA14

AA15

AA16

. Portable telephones

. . Cordless telephones

. . . using light

. . . using sound waves

. . . using electromagnetic induction fields

. . Automobile telephones

BB00
PURPOSE; EFFECT

BB01

BB02

BB03

BB04

BB05

BB06

BB07

BB08

BB09

. Improvement of usability

. . Improvement of operability

. . Improvement of call quality

. . Improvement of reliability

. . . Prevention of malfunctions

. . . Countermeasures against power failure

. . . Countermeasures against noise

. . . Prevention of wiretapping

. . . Prevention of prank calls or fraudulent uses

BB11

BB12

BB14

BB15

BB17

. Compensation for line loss

. Impedance matching with lines

. Size reduction; Cost reduction

. . by using the same components

. Power saving

CC00
KIND OF TELEPHONE LINE

CC01

CC02

CC04

CC06

CC08

. Digital lines

. . Integrated services digital network or ISDN lines

. Four-wire lines

. Exclusive lines

. Wireless lines

DD00
CALL CIRCUIT

DD01

DD02

DD03

DD04

DD05

DD07

DD08

DD10

. Anti-side-tone circuits

. . using hybrid coils

. . . Bridge types

. . . Booster types

. . using impedance bridges

. Howling prevention circuits

. . controlling transmitter and receiver gains

. Echo canceller circuits

DD11

DD12

DD14

DD16

DD18

. Transmitter circuits

. . eliminating background noise

. Receiver circuits

. Automatic adjustment of sound volume or tone quality

. considering the background noise

EE00
SIGNAL CIRCUIT

EE01

EE02

EE03

EE04

. Signal-generation circuits

. . Hooking signals

. . Dialling signals

. . . Automatic dialling

EE11

EE12

EE13

EE14

EE15

EE16

EE17

. Signal-detector circuits

. . Hooking signals

. . Dialling signals

. . . Medium-frequency or MF signals

. . Calling signals

. . Loop currents

. . . Polarity inversion

FF00
INDICATOR CIRCUIT

FF01

FF02

FF03

FF04

FF05

FF06

FF07

. Objects to be indicated

. . Line states

. . . Ringing

. . . Busy

. . . Call ends

. . . Holding

. . . Interrupting

FF12

FF13

FF14

FF16

. . Abnormal states

. . . Hand-sets left off the hook

. . . Abnormal power-sources

. . Sound volume

FF21

FF22

FF23

FF25

FF26

FF27

FF28

FF29

FF30

. Indicator means

. . Visual indication

. . . Blinking

. . Audible indication

. . . Combinations of multiple tones

. . . Single tones

. . . Voices

. . . Adjustment of sound volume or tone quality

. . Remote indication

GG00
OTHER CIRCUIT

GG01

GG02

GG03

GG04

GG05

GG06

GG07

GG08

. Protective circuits; Protective devices

. Power-source circuits

. . using batteries

. . . chargeable

. . using commercial power sources

. . using loop currents

. Resonance preventive circuits

. Timers; Time-constant circuits

HH00
TELEPHONE FUNCTION

HH01

HH02

HH03

HH04

HH05

HH06

HH07

HH08

HH09

. Loudspeakers

. . On-hook transmission

. . . Hands-free calls

. . Switching between handset calls and hands-free calls

. Holding

. . Switching of hold sounds

. . informing hold releasing

. Transferring

. . changing transfer destinations from other terminals

HH11

HH12

HH13

HH14

HH15

HH16

HH17

HH18

HH19

HH20

. Limits to making calls

. . Limits to making toll calls

. . using mechanical locking means

. Limits to receiving calls

. . Forced cutoff after closing lines

. Call privacy

. Monitoring

. Call interruption

. Voice synthesis

. Voice recognition

HH21

HH22

HH23

HH24

HH26

HH27

HH28

HH29

HH30

. Called party identification

. . using passwords

. Calling party identification

. . using passwords

. Combinations with other electrical devices

. . Clocks

. . Calculators

. . Audio-visual devices

. . Lighting

JJ00
TELEPHONE EXTENSION ARRANGEMENT

JJ01

JJ02

JJ03

JJ04

JJ05

JJ07

. using one or more telephone extensions

. . Two-party telephone lines

. . using two or more telephone extensions

. . . Multi-party telephone lines

. . . . Wire-broadcast telephones

. Extension calling; Extension calls

KK00
CONNECTING DEVICE

KK01

KK02

KK03

KK04

KK06

KK07

. Connections between telephones and hand-sets

. Connections between substations and telephone lines

. . Connections between telephones and telephone lines

. . . Connections between multiple telephones and telephone lines

. Terminal boards; Terminal boxes

. Connectors

LL00
TESTING

LL01

LL02

LL03

LL05

LL06

LL08

. testing substations

. . testing telephones

. . . testing acoustic characteristics

. testing telephone lines

. . Polarity check; Core discrimination

. Hand-sets for testing

MM00
OTHERS

MM01

MM02

MM03

MM04

MM05

. Non-linear elements

. Relays

. Cards, e.g. ICs or magnetic cards

. Switches

. Photocouplers

MM11

MM12

MM13

MM15

MM16

MM17

. Sound-emitting elements

. . Bells

. . Buzzers; Sounders

. Light-emitting elements

. . Light-emitting diodes

. . Liquid-crystal displays or LCDs

5K027	TELEPHONE CIRCUITS
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