Laser trigger for bass drum

Abstract

A laser trigger for a bass drum includes an enclosure attached to a drum rim which contains at least one reader of strokes performed with a foot pedal beater. The stroke reader is directed towards the beater, and has a laser beam emitter and the photoelectric element, whereas the retroreflective coating is applied on the pedal beater to reflect the laser beam in the direction of the photoelectric element at the moment of stroke. The enclosure/housing cavity includes a stroke recognition circuit based on parameters of the electric signal from the photoelectric element connected with the processing circuit that includes an audio frequency electric signal generator, which is connected with the output connector to connect the cable for outputting these signals for further processing and amplification.

Claims

1. A laser trigger for a bass drum comprising: a housing attached to a drum rim with at least one reader of strokes performed with a foot pedal beater, wherein the stroke reader is positioned in a lower portion of the enclosure and is directed towards the foot pedal beater, and comprises a laser beam emitter and a photoelectric element; a retroreflective coating on the foot pedal beater for reflecting a laser beam in a direction of a photoelectric element at a moment of stroke; and the housing including a stroke recognition circuit based on parameters of the electric signal from the photoelectric element connected to a processing circuit, the processing circuit including an audio frequency electric signal generator which is connected to an output connector to enable further processing and amplification.

2. The laser trigger of claim 1, wherein the stroke reader is attached to the enclosure using a hinge that allows deflecting the laser beam and pointing it in a desired direction.

3. The laser trigger of claim 1, wherein the audio frequency electric signal generator is a wave synthesizer with an integrated database that has a set of digitized waveforms of previously recorded audio signals.

4. The laser trigger of claim 1, wherein the audio frequency electric signal generator is a physical modeling sound synthesizer.

Description

DESCRIPTION OF THE ATTACHED FIGURES

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

[0018] In the drawings:

[0019] FIG. 1 shows a block diagram of a laser trigger for a bass drum;

[0020] FIG. 2 shows a structural diagram of a laser trigger;

[0021] FIG. 3 shows an arrangement of a device on a bass drum.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0023] The present invention provides a structure of the laser trigger device designed for picking up the sound of the bass drum at electronic music concerts and in studios. The device can be used instead of the usual microphone or together with the microphone. The bass drum means the drum, hitting whereon is performed by way of tilting the foot pedal which carries the beater. When pushing the pedal, the beater, pinned with the possibility of swinging, deflects to the acoustic membrane of the drum and hits it. The beater travel speed immediately before contact with the membrane determines the force and amplitude of the sound wave emitted by the drum into the ambient environment.

[0024] The laser trigger includes the enclosure attached to the bass drum rim, which contains at least one reading head, including the laser beam emitter and the photoelectric element located in the output area of this beam at the bottom portion directed towards the beater head. The sticker made of the retroreflective material is attached onto the beater head for the purpose of reflecting the laser beam in the direction of the photoelectric element at the moment of the beater striking the acoustic membrane. The enclosure cavity accommodates the stroke recognition circuit based on the electric signal from the photoelectric element connected with the pulse processing circuit that includes an audio frequency electric signal generator, which is electrically connected with the connector to connect the cable for the purpose of transmission of the signal to external acoustic systems used for sound amplification.

[0025] The audio frequency electric signal generator may be represented by a wave synthesizer or a physical modeling sound synthesizer.

[0026] The audio frequency electric signal generator based on the wave synthesizer is made as a software module implemented within the microcontroller. The module output receives commands from the stroke recognition circuit. While in operation, the wave synthesizer addresses the memory chip, where the waveform database is stored in the digitized form. Serial reading of digital values, scaling thereof according to the stroke force, and serial output to the chip of the digital-to-analog converter, at the output whereof the continuous electric signal of audio frequency is obtained, are performed when the drum is played.

[0027] The audio frequency electric signal generator based on the physical modeling sound synthesizer is made, for example, as a software module implemented within the microcontroller, or, optionally as a firmware, an ASIC or FPGA. The module input receives commands from the stroke recognition circuit. The physical modeling sound synthesizer addresses the mathematical model of the musical instrument in the course of operation. Serial reception of digital values as a result of cyclic computation of the discretized equation which accepts the stroke event and force, as well as the set of variable values assigned by custom settings as arguments, are performed during reproduction. The obtained computational results are outputted in series to the chip of the digital-to-analog converter, at the output whereof the continuous electric signal of audio frequency is obtained.

[0028] An example of a specific embodiment of the invention is described below with reference to the drawings.

[0029] As shown in FIG. 1, the devices comprises the following parts: the reading head 1 (or several reading heads) including the photoelectric element 2 and the laser beam emitter 3, the stroke recognition circuit 4, the audio signal waveform database storage 5, the processing circuit 7 including the audio frequency electric signal generator, as well as controls and indication elements, the switching mode power supply 8, the electric battery 9, the communication module 10, and the enclosure 11. All device components are combined in the enclosure 11 having the clamp 12 for attachment thereof to the bass drum rim (FIGS. 2 and 3). This mechanism can be made in the form of a C-clamp installed on the rim edge and attached using the bolt 13 carrying the wing nut 14. Electronic circuits (the stroke recognition circuit 4, the database storage 5, the processing circuit 7 including the audio frequency electric signal generator, etc.) are mounted on the common board, to thereby collectively form a single unit 15.

[0030] The present device fulfills several functions. The electronic board and the power supply element (battery) are positioned within the enclosure. The front panel allows the user to visualize the operation process and set operating parameters (by using the controls and indication elements on the surface thereof). The XLR connector 16 is installed on the rear side of the enclosure for connection of the signal cable. The lower housing 18 for fitting of two hinge joints, each of which accommodates the reading head 1 carrying the laser beam emitter and the photoelectric element, is formed on the lower side 17 of the enclosure, where there is an attachment mechanism, i.e., a clamp for installation of the device on the bass drum rim. The hinge joint is spring-loaded with the O-ring 19 which makes it fixed when playing, and provides the possibility by applying the force of a finger to deflect the reading head 1, as well as the laser beam 20 in two degrees of freedom, and point it at the desired position (in this case, at the retroreflective sticker 21 positioned on the upper surface of the beater head 22 at the time of contact thereof with the plastic surface 25 of the bass drum). The standard beater is connected with the foot pedal 24 by the hinge 23. There is a window allowing to replace the battery without removing the instrument from the drum on the side of the enclosure 11.

[0031] The operating principle of the device is based on tracking of the position of the bass drum pedal beater using the laser beam. The beater is equipped with the coating made of retroreflective material. The reading head comprises the laser beam emitter and the photoelectric element. The laser beam is pointed in such a manner so as to fall on the reflective material at the time of stroke. Owing to the properties of the retroreflective material, the laser beam is reflected and pass back to the reading head, where it falls to the photoelectric element located in the maximum vicinity to the emitter outlet port. The electronic circuit recognizes the stroke event according to the signal from the photoelectric element. This signal is processed, after which the command is generated for the wave synthesizer to playback the previously recorded audio signal.

[0032] There are two operational modes: [0033] If performance does not require transmission of the stroke force, and all sounds have to be the same in terms of volume (amplitude), then each appearance of the beater with the retroreflective coating in the path of the laser beam will result in the command to reproduce the sound. [0034] For performance of musical composition, where transmission of dynamics is required, when the command to reproduce the sound has to differ and depend on the stroke force, the other operation mode of the instrument is implemented: a certain pattern is applied on the retroreflective surface (e.g., a stripe). The retroreflective material appears in the beam path during the stroke not on a single occasion, but discontinuously, being masked by the pattern. This causes repeated front of the electric signal from the photoelectric element, as well as the sequence of pulses according to the pattern. When processing the signal from the photoelectric element, the electronic circuit recognizes the sequence of pulses and assesses the speed thereof. The stroke force is defined by that speed, and the command to reproduce the sound is generated: the higher the pulse sequence speed, the stronger the stroke.

[0035] The structural design provides for availability of fitting one or two reading heads within the single device. This makes it possible to operate both the single and stereo pedals.

[0036] The enclosure (housing) includes the built-in communication module 10 for control and service using the external electronic device which can be a computer, a tablet PC or a smartphone. After connecting to this device, the user is able to visualize device operation remotely, control basic parameters, download files with sound waveforms, and gains access to configuration parameters. It is now possible to update the internal device firmware. One of advantages of the claimed invention is that the device does not require any retrofitting of a musical instrument, since it is attached to the conventional rim of the bass drum. This makes the device suitable for quick installation, literally in one minute.

[0037] The device is an accessory to a musical instrument, and its presence does not affect functioning and sounding of the instrument in any way. There is no need to interfere with the foot pedal mechanism or replace any drum parts. Therefore, a musician who got used to playing on his/her instrument and using his/her pedal will not feel uncomfortable due to strangeness of perception. Given invention represents a functionally complete product and is ready for operation immediately after attachment to the conventional drum rim. The combined all-in-one solution allows omitting assembly of the circuit from separate units and connecting cables, thus saving time significantly and improving reliability. Battery power supply allows for independent operation and removes the need to search for an AC connection.

[0038] Having thus described a preferred embodiment, it should be apparent to those skilled in the art that certain advantages of the described method and system have been achieved.

[0039] It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. The invention is further defined by the following claims.