Patent Grant
8431814
1. Field of the Invention
This invention relates to musical instruments. Specifically, and not by way of limitation, the present invention relates to a laser pick-up for use on a stringed musical instrument.
2. Description of the Related Art
There are a wide variety of stringed musical instruments. One very popular stringed instrument is an electric guitar. A conventional electric guitar is a type of guitar which utilizes pick-ups to convert the vibration of its steel-cored strings into an electrical current. The electric current is then amplified by an instrument amplifier and outputted as sound through a speaker. Oftentimes, the signals emanating from the guitar are electronically altered with guitar effects, such as reverb or distortion.
Electric guitars make comparatively little audible sound in comparison to an acoustic guitar because the strings of an electric guitar have their strings plucked. Instead, the movement of the strings generates or induces a very small electrical current in the magnetic pick-ups. The magnetic pick-ups are magnets which are wrapped with coils of very fine wire. The induced current is then sent via a wire to an amplifier. The induced current is dependent upon such factors as the density of the string or the amount of movement over the pick-ups. The vibration of the strings is, in turn, affect by several factors, such as the composition and shape of the body of the guitar.
There are also some hybrid electric-acoustic guitars which are equipped with additional piezoelectric pick-ups or transducers that sense mechanical vibrations from the body of the guitar. Because in some cases it is desirable to isolate the pick-ups from the vibrations of the strings, a guitar's magnetic pick-ups are sometimes embedded or “potted” in epoxy or wax to prevent the pick-up from having a “microphone” effect.
Because of their natural inductive qualities, magnetic pick-ups suffer from the disadvantage of picking up ambient and usually unwanted electromagnetic noises. The resulting noise, an unwanted “hum,” is particularly strong with single-coil pick-ups, and aggravated by the fact that very few guitars are correctly shielded against electromagnetic interference. The most frequent cause of this hum is the strong 50 or 60 Hz component that is inherent in the frequency generation of current within the local power transmission systems. As nearly all amplifiers and audio equipment associated with electrical guitars relies on this power, there is, in theory, little chance of completely eliminating the introduction of unwanted hum.
Double-coil pick-ups, also known as “humbuckers,” were invented as a way to reduce or counter the unwanted ambient hum sounds. Humbuckers have two coils of opposite magnetic and electric polarity. Thus, electromagnetic noise hits both coils, which should cancel itself out. The two coils are wired in phase, so the signal picked up by each coil is added together. This creates the richer, “fatter” tone associated with humbucking pick-ups. A pick-up is needed which is not susceptible to picking up unwanted ambient noises.
Thus, it would be advantageous to have a pick-up for use on stringed instruments which generates signals from vibrating strings of a musical instrument without picking up unwanted ambient noise. It is an object of the present invention to provide such an apparatus and method.
The present invention is a light pick-up apparatus and method for use on a stringed musical instrument. In one aspect, the present invention is directed to a light pick-up that includes a laser diode affixed to the musical instrument. The laser diode is capable of generating a laser beam. The laser pick-up also includes a photodetector affixed to the musical instrument adjacent the laser diode. The photodetector is capable of detecting light from the laser beam. The photodetector includes a conversion mechanism for converting the detected light into electrical signals. The laser diode is positioned on the musical instrument to direct the laser beam toward the string. The laser beam is reflected off the string and received by the photodetector. The photodetector then converts the detected light from the reflected laser beam into electrical signals which provide sound to an amplifier.
In another aspect, the present invention is directed to a light pick-up system for use on a musical instrument. The system includes a musical instrument having at least one string, a body, and an outer surface. The system also includes at least one light pick-up corresponding to the string. The light pick-up includes a light generation mechanism affixed to the musical instrument. The light generation mechanism generates a light beam. The light pick-up also includes a photodetector affixed to the musical instrument adjacent the light generation mechanism for detecting light from the light beam. The photodetector is capable of converting the detected light into electrical signals. The light generation mechanism is positioned on the musical instrument to direct the light beam toward the string. The light beam is reflected off the string and received by the photodetector. The photodetector converts the detected light from the reflected light beam into electrical signals.
In still another aspect, the present invention is directed to a method of utilizing a light pick-up having a light generation mechanism and a photodetector located on a musical instrument having at least one string. The method begins by the light generation mechanism emitting a light beam. The light beam is then reflected off the string of the musical instrument. Next, the photodetector detects the light from the reflected light beam and converts the detected light into electrical signals. The electrical signals are then converted into sound corresponding to the vibrations of the string.
The present invention is a laser pick-up for a stringed instrument.
The musical stringed instrument 12 may be any musical instrument having strings, such as a guitar, a violin or a cello. The laser pick-up is attached to the body of the stringed instrument 12 near the strings of the stringed instrument 12.
The laser pick-up also includes a photodetector 40 mounted in a channel 42. The photodetector 40 is coupled in an electrical pin or pins 44 providing power to the photodetector 40. An optical filter 46 is preferably located over the photodetector. The photodetector is position adjacent the surface 38. The photodetector 40 is preferably canted at an opposing 30 degree angle relative to the laser diode from the X-axis.
The laser diode is powered from a power source (not shown) coupled to the pins 34. The laser diode generates a laser beam 50, preferably invisible to the naked eye, which detects vibrations of a musical instrument string 52 located adjacent the laser generation mechanism 16. The laser beam 50 bounces off the string 52 and is detected by the photodetector 18.
In the present invention, the electromagnetic pick-ups utilized in convention electric stringed instruments (e.g., an electric guitar) are replaced by the array 60. The array includes a plurality of the laser diodes 30, one for each string 52. As depicted in
In the preferred embodiment of the present invention, the size of each laser beam is matched to the diameter of its corresponding string. Preferably, the beam has a width less than the diameter of the string. To facilitate the proper sizing of the laser beams, the laser apertures may be sized to narrow the width of the laser beam. Preferably, the apertures are rectangularly shaped and formed in plastic or metal disks. The apertures are located over the diodes, thereby shaping the profile of each beam to match its corresponding string. The apertures may also be utilized to direct the laser beam in a desired direction. Thus, the apertures may be utilized to refine the direction for which the beam is aimed, preferably towards a specific string.
In order to minimize the influence of corrupting signs, the present invention preferably utilizes the optical filters 46. The optical filters are positioned over the photodetectors 40. The optical filters are transparent only for the wavelengths of light generated by the lasers. Other wavelengths, especially those of visible light, are blocked.
In a preferred embodiment of the present invention, an electronic band-pass filter (not shown) affixed to a top of each laser diode 30 may be utilized. These filters only allows audible signals to pass (i.e., those signals created by the laser beams 50). Static signals, produced when the laser light reflects off static (i.e., non-vibrating) strings are undesired.
The present invention may be utilized on any stringed instrument. Any laser generation device may be used which can emit laser light. In addition, any type of laser detection mechanism may be used to detect reflected light. The present invention may be affixed to an existing stringed instrument or incorporated during the manufacture of the musical instrument.
In an alternate embodiment of the present invention, any light source may be utilized which produces a light beam. The present invention is not limited to laser emissions, but may utilize any type of light beam which can reflect off the string. For example, a light-emitting diode may be utilized to provide a light beam to reflect off of the string and be detected by the photodetector.
The present invention provides a unique apparatus and method for sensing vibrating strings. The present invention solves the existing problems associated with distorted noise or humming found in most electrical guitars.
Thus, the present invention has been described herein with reference to a particular embodiment for a particular application. Those having ordinary skill in the art and access to the present teachings will recognize additional modifications, applications and embodiments within the scope thereof.
It is therefore intended by the appended claims to cover any and all such applications, modifications and embodiments within the scope of the present invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4815353 | Christian | Mar 1989 | A |
| 5012086 | Barnard | Apr 1991 | A |
| 5446751 | Wake | Aug 1995 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20100011942 A1 | Jan 2010 | US |
