Electromagnetic field pickup for musical instruments

• US 8,129,607 B2
• Filed: 03/03/2009
• Issued: 03/06/2012
• Est. Priority Date: 03/04/2008
• Status: Expired due to Fees

• Current Assignee: Robert Francis Joseph Loftus
• Original Assignee: Robert Francis Joseph Loftus
• Inventors: Loftus, Robert Francis Joseph
• Primary Examiner(s): Fletcher, Marlon
• Application Number:
  US12/396,711
• Publication Number:
  US 20090223353A1
• Time in Patent Office: 1,099 Days
• Field of Search: None
• US Class Current: 84/723
• CPC Class Codes: G10H 2220/431 Use of microwaves
• CPC Class Codes: G10H 2220/565 Shielding, electromagnetic or magnetic, e.g. for transducers, i.e. for controlling, orienting or suppressing magnetic fields or for preventing unintentional generation, propagation and reception of electromagnetic energy in electrophonic musical instruments, their vicinity or their interconnections dual coil humbucking transducers G10H2220/505
• CPC Class Codes: G10H 3/18 using a string, e.g. electric guitar mechanical features G10D1/085

Abstract

An electromagnetic field pickup (10) for a musical instrument including an electromagnetic signal generator (12), an electromagnetic field transducer (18), a mixer (28), the electromagnetic signal generator (12), the electromagnetic field transducer (18) and the mixer (28) are respectively connected in series, the electromagnetic signal generator (12) is also connected directly to the mixer (28), so constructed and arranged that when power is supplied to the electromagnetic field pickup (10) an audio electrical signal of substantially same pitch, intonation and sustain as a vibrating element (22) of the instrument is generated.

Claims

1. An electromagnetic field pickup for a musical instrument comprising:

a) an electromagnetic signal generator;

b) an electromagnetic field transducer;

c) a mixer;

the electromagnetic signal generator, the electromagnetic field transducer and the mixer are respectively connected in series;

the electromagnetic signal generator is also connected directly to the mixer;

so constructed and arranged that when power is supplied to the electromagnetic field pickup a first electromagnetic signal and a second electromagnetic signal are respectively sent from the electromagnetic signal generator to the electromagnetic field transducer and the mixer;

a first electromagnetic field derived from the first electromagnetic signal is transmitted from the electromagnetic field transducer towards a vibrating element of the musical instrument;

a second electromagnetic field derived by re-radiation and Doppler shifted modulation of the first electromagnetic field is received from the vibrating element by the electromagnetic field transducer;

a third electromagnetic signal derived from the second electromagnetic field is sent from the electromagnetic field transducer to the mixer;

the third electromagnetic signal and the second electromagnetic signal are mixed by the mixer to produce a fourth electromagnetic signal; and

the fourth electromagnetic signal includes a difference signal being a musical frequency audio electrical signal of substantially same pitch, intonation and sustain as a sound vibration from the vibrating element of the musical instrument.

2. The electromagnetic field pickup as recited in claim 1 further comprising a filter connected to the mixer.

3. The electromagnetic field pickup as recited in claim 2 further comprising an audio amplifier connected to the filter.

4. The electromagnetic field pickup as recited in claim 3 where the mixer is a mixer diode biased to operate in an optimum region of the mixer diode'"'"'s range of operation.

5. The electromagnetic field pickup as recited in claim 4 where the electromagnetic field transducer includes an array of dielectric chip antennas.

6. The electromagnetic field pickup as recited in claim 5 in which the dielectric chip antennas are oriented with respect to the vibrating element so that a radiated field produced by the dielectric chip antennas has a same polarization as the vibrating element.

7. The electromagnetic field pickup as recited in claim 4 where the electromagnetic field transducer is a waveguide antenna having at least one slot.

8. The electromagnetic field pickup as recited in claim 7 where alignment of the waveguide antenna with respect to a string of the vibrating element is such as to place the slot substantially at right angle to the string and to place the string substantially over a centre of the slot so that a radiated field emitted from the slot has a same polarization as the string.