Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
  • G11B27/005—Reproducing at a different information rate from the information rate of recording
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
  • G10H1/00—Details of electrophonic musical instruments
  • G10H1/0091—Means for obtaining special acoustic effects
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
  • G11B19/02—Control of operating function, e.g. switching from recording to reproducing
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
  • G11B20/10—Digital recording or reproducing
  • G11B20/10527—Audio or video recording; Data buffering arrangements
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
  • G10H2210/00—Aspects or methods of musical processing having intrinsic musical character, i.e. involving musical theory or musical parameters or relying on musical knowledge, as applied in electrophonic musical tools or instruments
  • G10H2210/155—Musical effects
  • G10H2210/195—Modulation effects, i.e. smooth non-discontinuous variations over a time interval, e.g. within a note, melody or musical transition, of any sound parameter, e.g. amplitude, pitch, spectral response, playback speed
  • G10H2210/241—Scratch effects, i.e. emulating playback velocity or pitch manipulation effects normally obtained by a disc-jockey manually rotating a LP record forward and backward
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
  • G10H2220/00—Input/output interfacing specifically adapted for electrophonic musical tools or instruments
  • G10H2220/461—Transducers, i.e. details, positioning or use of assemblies to detect and convert mechanical vibrations or mechanical strains into an electrical signal, e.g. audio, trigger or control signal
  • G10H2220/521—Hall effect transducers or similar magnetic field sensing semiconductor devices, e.g. for string vibration sensing or key movement sensing
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B2220/00—Record carriers by type
  • G11B2220/20—Disc-shaped record carriers
  • G11B2220/25—Disc-shaped record carriers characterised in that the disc is based on a specific recording technology
  • G11B2220/2537—Optical discs
  • G11B2220/2545—CDs

Definitions

• the present invention relates to a digital processing device for an audio signal.
• scratching has become established as a generally acknowledged musical instrument and has been utilized in numerous music productions. More and more music groups are also using scratch musicians live.
• scratch aids exist for digital recording-and-playback apparatus (music samplers) in the form of scratch discs, slide potentiometers, knobs, etc.
• the object of the invention is to propose a device which avoids the drawbacks of the prior art.
• This object is achieved especially thanks to the novel elements of claim 1.
• this object is achieved thanks to a reference generated mechanically and making it possible to pass instantly from normal reproduction to manipulated reproduction.
• the invention can be realized using any other kind of moving element, for instance a running belt or a rotating knob or control button on the front panel of an audiomixer.
• Figure 1 A is a front elevation of a first embodiment of the invention wherein the movable element, the speed and direction of which can be controlled, is made up of a record-player tumtable ;
• Figure 1 B is a top plan view of this embodiment ;
• Figure 1 C is an elevation of this embodiment with the incremental measuring system in lifted position ;
• Figure 2A is an elevation of a second embodiment of the invention likewise applied to a record player, wherein the speed of the turntable is measured optically ;
• Figure 2B is an enlarged view of the optical sensors of Figure 2A ;
• Figure 2C is a top plan view of the device of Figure 2A ;
• Figure 2D is an enlarged view of the optical marking on the tumtable of Figure 2C ;
• Figure 3A is a top plan view of a third embodiment of the invention, likewise applied to a record player, wherein the speed of the tumtable is measured by means of a Hall sensor ;
• Figure 3B is an enlarged view of the Hall sensor of Figure 3A ;
• Figure 4A is a fourth embodiment of the invention wherein the movable element is a belt driven by an electric motor via a slide coupling;
• Figure 4B is an elevation of the embodiment of Figure 4A.
• FIGS 1A-1C illustrate a first embodiment of the invention.
• This embodiment has the advantage of using a conventional record player 18 as the manually controllable movable element. This device can therefore be used by a disc jockey without excessive difficulty of adaptation.
• a disc 16 drives an incremental measuring system 11 available on the technical market under the name of incremental decoder or angle encoder.
• pulses occurring after predetermined intervals of time are used directly as the sampling pulse for the recording and playback of the digital music recording.
• each pulse triggers a measurement of the analog music signal from an external source, e.g., from a CD player, and enters the result as a numerical value in a storage position of a dynamic computer memory (not shown).
• the individual measurements lie one directly behind the other in the memory. It is to be heeded that the measuring system is a high-definition one. If satisfactory quality of the music reproduction is to be achieved, the sampling rate should yield 40,000 measurements per second.
• the measuring system At the normal rotation time of a record (speed of rotation 33.33 rpm) of 1.8 seconds, the measuring system must be capable of handling 72,000 pulses per rotation, or 18 angular seconds.
• the direction of rotation is evaluated in addition.
• the following and/or preceding storage position is converted, depending on the the direction of rotation, from digital to analog.
• the software addressing the computer memory can thereafter be as sophisticated as desired ; as a minimum, however, it must check the addressing of the computer memory present for overflows ; if, during recording or forward playback, the pointer reaches the end address of the memory provided, the pointer is to be set at the starting address of the memory provided, or at the end address in the case of backward play and reaching the starting address, respectively. It is thereby achieved that if the maximum available recording time is exceeded, the oldest recording is overwritten, which represents approximately the same mechanism as an endless tape loop in an analog echo apparatus.
• the signal should be digitalized with 16-bit width and be two- channel, i.e., stereo.
• FIGS 2A-2D illustrate a second embodiment of the invention, likewise applied to a record player.
• the turntable 16 of the record player comprises a pattern — in this example a pattern of altemating black 20 and white 23 marks.
• Two optical sensors 21 placed a short distance 22 above the turntable supply to a processing unit (not shown) a signal determined by the color of the mark just below each sensor.
• the processing unit determines the speed of rotation of the turntable of the record player.
• Two shifted optical sensors are necessary for determining the direction of rotation as well.
• An analog audio signal coming from an external source e.g., a CD player or a microphon, is then sampled at a frequency determined by the speed of rotation of the tumtable.
• optical sensor 21 may be provided, e.g., also a sensor using an optical fiber transporting a light beam collimated by a lens on the turntable. In a modification, it is also possible to use known marble sensors to determine the speed of the element 16.
• This embodiment having an optical sensor presents the drawback of being sensitive to dust and debris on the tumtable.
• Figures 3A and 3B illustrate another embodiment of the invention which is advantageous from this point of view.
• the speed of the turntable 16 of the record player is measured by means of a fixed magnetoinductive sensor 31 co-operating with a serrated ferromagnetic ring 30 on the tumtable of the record player.
• the invention is obviously not limited to this type of sensor, and any sensor or known device permitting the speed and direction of rotation of the tumtable to be determined may also be used. Hall-effect sensors may thus be used advantageously.
• FIGS 4A and 4B illustrate an embodiment of the invention in which no record player is used.
• a controllable servomotor 40 drives a cylinder 42 via a slide coupling 41.
• a second cylinder 43 connected to the measuring system 44 is driven by the first cylinder 42 by means of a wide belt 45.
• the disc jockey can manipulate and move the belt 45 by means of a handle 46 and thus act upon the speed and direction of rotation of the second cylinder 43.
• the measuring system 44 uses these parameters to determine the speed of reproduction of an audio signal coming from an external source.
• this device permits normal sound reproduction when the disc jockey does not act upon the movable element 45, the second cylinder being driven in this case at a normal speed by the servomotor 40.
• the electronic part of the device comprises a sampling buffer.
• the analog signal coming from a conventional analog source for instance a microphon
• a conventional analog source for instance a microphon
• the samples stored in the buffer are read successively at each reading pulse, the frequency of the reading pulses depending on the speed of the movable element (16, 45).
• the samples read are then converted into analog signals by a digital-to-analog converter and reproduced.
• the samples are stored in the sampling buffer at a speed inversely proportional to the speed of movement of the movable element (16 ; 45) and are read at a constant speed.

Applications Claiming Priority (3)

Publications (1)

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ID=4218878

Family Applications (1)

Country Status (3)

Families Citing this family (44)

Family Cites Families (6)

• 1996
  • 1996-06-19 EP EP96922833A patent/EP0880779A1/de not_active Withdrawn
  • 1996-06-19 WO PCT/EP1996/002637 patent/WO1997001168A1/en active Application Filing
  • 1996-06-19 AU AU63569/96A patent/AU6356996A/en not_active Abandoned

Non-Patent Citations (5)

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