Patent Application
20090279730
In the first half of the 20th century, ribbon microphones once dominated commercial broadcasting and recording industries as a preferred high-end microphone technology. First developed by Dr. Harry F. Olson of RCA corporation in the late 1920's, Ribbon microphones widely commercialized in the 1930's exhibited superior frequency responses and higher-fidelity output signals compared to many condenser microphones of the time.
A ribbon microphone typically uses a thin piece of metal immersed in magnetic field generated by surrounding magnets. The thin piece of metal is generally called a “ribbon” and is often corrugated to achieve wider frequency response and fidelity. Ribbon microphones became vastly popular and became a primary broadcasting and recording microphone until mid-1960's.
However, the classic ribbon microphone architecture was susceptible to significant disadvantages. First, a typical ribbon microphone contained a fragile ultra-thin ribbon, typically made of corrugated aluminum, which could break easily if the ribbon microphone casing was subject to a gust of air through its microphone windscreen. Second, most ribbon microphones could not produce as high output signal level as condenser or dynamic microphones. The lack of high output signal level for ribbon microphones usually required careful pre-amplification matching and tuning, which was cumbersome and contributed to reduced ruggedness and reliability compared to condenser and dynamic microphones.
By the mid-1960's, dynamic moving-coil microphones (i.e. coil wire on a diaphragm suspended over a magnetic field) and condenser microphones (i.e. capacitor microphones) evolved technologically for higher sensitivity and signal-to-noise ratio (SNR) to compete effectively against ribbon microphones. For example, improved condenser microphones exhibited substantially higher output signal level than ribbon microphones, thereby simplifying pre-amplification process and improving reliability of recording or broadcasting equipment.
Although a typical condenser microphone had the tendency of exaggerating upper frequency ranges whenever inherent harmonic resonances occurred in a diaphragm of the microphone, the exaggerated upper frequency was actually preferred by some while recording industry started using analog tape mediums for audio recording. Most analog tapes suffered generational signal losses and could not accurately capture high-frequency ranges, which made the use of condenser microphone-based recording equipment more acceptable. Similarly, although dynamic moving-coil microphones fundamentally possessed higher resistivity to sound waves than ribbon microphones, improved dynamic moving-coil microphones provided ways to compensate for a relatively low high-frequency response. Therefore, by the mid-1960's, most ribbon microphones were rapidly replaced by more portable, rugged, and user-friendly condenser and dynamic moving-coil microphones. By the end of that decade, ribbon microphones were widely considered obsolete.
However, despite several drawbacks as mentioned above, ribbon microphones possess fundamental advantages as recording and broadcasting industry become fully adjusted to the digital era. As Compact Discs and solid-state non-volatile memory (e.g. NAND flash memory) became recording media of choice for highly digitized recording and broadcasting equipment, the high-frequency exaggeration and distortion provided by condenser microphones were no longer desirable. Many audio engineers and music lovers began to favor more natural and linear reproduction of sound, which meant that ribbon microphone's fundamentally higher fidelity in higher frequencies received attention once again. Ribbon microphones also provide a generally richer and fuller sound reproduction compared to condenser and dynamic moving-coil microphones with digital audio recording and broadcasting equipment. In recent years, there has been a resurgence of demand for retrofitted ribbon microphones of yore and a need for newly-designed ribbon microphones, especially in the high-end audio industry.
For a newly-designed ribbon microphone, it is desirable to isolate a ribbon (i.e. typically made of thin corrugated piece of aluminum) from a ribbon housing's vibrations or oscillations caused by an external shock or rumble. Vibrations or oscillations of the ribbon housing can introduce unnecessary noise to the ribbon and degrade the quality of an output signal from the ribbon. Furthermore, for the newly-designed ribbon microphone, it is also desirable to simplify the output signal wiring of the ribbon for higher durability, manufacturing cost, and vibration-reduction. Therefore, a novel shock-absorbing apparatus addressing at least some of these issues is desirable.
A shock-absorbing apparatus inside a ribbon microphone housing is disclosed. The shock-absorbing apparatus comprises a ribbon microphone frame suspended at least partly in air by one or more spring elements, wherein the one or more spring elements are configured to reduce shock energy translated to a ribbon inside the ribbon microphone frame upon receipt of an external mechanical shock, the ribbon configured to generate electric output signals by reacting to sound waves, wherein the ribbon is located inside the ribbon microphone frame and at least partly immersed in a magnetic field generated by a magnet, and an electrically-conductive spring element electrically and operatively connected to one end of the ribbon to one or more transformers, wherein the electrically-conductive spring element is configured to transmit the electric output signals to the one or more transformers.
In addition, a ribbon microphone housing containing a shock-absorbing apparatus is disclosed. The ribbon microphone housing comprises a ribbon microphone frame suspended at least partly in air by one or more spring elements, wherein the one or more spring elements are configured to reduce shock energy translated to a ribbon inside the ribbon microphone frame upon receipt of an external mechanical shock, the ribbon configured to generate electric output signals by reacting to sound waves, wherein the ribbon is located inside the ribbon microphone frame and at least partly immersed in a magnetic field generated by a magnet, an electrically-conductive spring element electrically and operatively connected to one end of the ribbon to one or more transformers, wherein the electrically-conductive spring element is configured to transmit the electric output signals to the one or more transformers, a first electrode physically connected to the one end of the ribbon and a second electrode operatively connected to another end of the ribbon, wherein the first electrode is configured to transmit the electric output signal from the ribbon to the electrically-conductive spring element, and the second electrode is connected to an electrical ground, and the one or more transformers configured to receive the electric output signals generated by the ribbon to produce a desirable electrical voltage and/or gain characteristics and an appropriate impedance matching to the ribbon while maintaining a wide frequency response.
Specific embodiments of the invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency.
In the following detailed description of embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.
In general, embodiments of the invention relate to a ribbon microphone. More specifically, an embodiment of the invention relates to a shock-absorbing apparatus for a ribbon microphone housing, wherein the shock-absorbing apparatus reduces vibration translated to a ribbon (e.g. a thin corrugated piece of aluminum) and a ribbon microphone frame containing the ribbon when an external shock is exerted to the ribbon microphone housing.
Another embodiment of the invention relates to utilizing one or more elastic spring elements to suspend at least a portion of the ribbon microphone frame in air. The use of elastic spring elements enables the ribbon microphone frame containing the ribbon to absorb at least a portion of an external shock when an external force (e.g. the ribbon microphone being knocked out to the ground, banging against an external object, external rumble, vibration, and etc.) is about to be transmitted to the ribbon itself. The shock-absorption by the ribbon microphone frame reduces unnecessary vibration to the ribbon, which results in higher-fidelity output signal generation by the ribbon with a reduction in unwanted noise.
Another embodiment of the invention relates to an electrically-conductive spring element which conducts an electric output signal from the ribbon to a transformer block, thereby simplifying wiring scheme between the ribbon and a transformer block.
Yet another embodiment of the invention relates to a ribbon microphone housing containing a shock-absorbing apparatus, wherein the ribbon microphone housing further includes a transformer block configured to produce a desirable electrical voltage-gain characteristics and an appropriate impedance matching to a ribbon inside a ribbon microphone frame.
Furthermore, one objective of the invention is to provide a shock-absorbing apparatus using one or more elastic spring elements attached to a ribbon microphone housing and a ribbon microphone frame containing a ribbon.
Another objective of the invention is to provide an electrically conductive spring element configured to transmit an output signal from the ribbon to simplify wiring requirements of the ribbon.
Yet another objective of the invention is to provide a fabric screen covering a substantial portion of a ribbon inside a ribbon microphone frame, wherein the fabric screen provides a protective layer for the ribbon from external elements while enabling the ribbon to achieve a high frequency response to the sound waves.
The shock-absorbing apparatus (100) of
It is important to note that the spring elements (101A, 101B, 101C, 101D) provide at least some shock absorption to the ribbon microphone frame (111) when an external shock or vibration is exerted to the shock-absorbing apparatus (100). This resulting shock absorption translates to a higher-fidelity signal output and noise reduction for the ribbon (113). In essence, the shock-absorbing apparatus (100) of the present invention provides some measure of isolation of the ribbon (113) and the ribbon microphone frame (111) from a ribbon housing's (109) vibrations or oscillations caused by an external shock or rumble. Because vibrations, rumble, or oscillations to the ribbon housing (109) can introduce unnecessary noise and degrade the quality of an output signal from the ribbon if left untreated, an effective measure of vibration dampening using the shock-absorbing apparatus (100) in accordance with an embodiment of the present invention provides substantial advantages over prior art.
Continuing with
Allowing at least one (101A) of the spring elements to conduct electrical signals from the ribbon (113) as shown by way of example in
Continuing with
Continuing with
In one embodiment of the invention, a ribbon (207) typically made of a thin corrugated piece of aluminum is affixed to the ribbon microphone frame (205) by a first clamp (203) and a second clamp (209). The ribbon (207) is also at least partially immersed in magnetic fields generated by one or more nearby magnets in the ribbon microphone frame (205).
In order to transmit electric output signals of the ribbon (207) generated by sound pressure waves for further processing, a first electrode (225) is operatively connected to a first end (e.g. top) of the ribbon (207) to an output signal path (215) via electrical conduction through an electrically-conductive spring element (e.g. 201A), which is electrically insulated from the shock-absorbing apparatus (202) by an electrical insulator (213). A second electrode (223) is operatively connected to a second end (e.g. bottom) of the ribbon (207) to the ground (217). The first electrode (225), the electrically-conductive spring element (201A), and the output signal path (215) are also operatively connected to a transformer block (211) to carry the output signals from the ribbon (207) to the transformer block (211). In one embodiment of the invention, the remaining spring elements (201B, 201C, 201D) are electrically grounded along with the second electrode (223) to the ribbon (207).
Continuing with
The particular exterior shape of the ribbon microphone (500) of
The present invention provides key benefits to conventional ribbon microphone designs. First, a shock-absorbing apparatus for a ribbon microphone housing disclosed in the present invention reduces vibration translated to a ribbon (e.g. a thin corrugated piece of aluminum) and a ribbon microphone frame containing the ribbon when an external shock is exerted to the ribbon microphone housing. By utilizing one or more elastic spring elements to suspend at least a portion of the ribbon microphone frame in air, the present invention enables the ribbon microphone frame containing the ribbon to absorb at least a portion of an external shock when an external force (e.g. the ribbon microphone being knocked out to the ground, banging against an external object, external rumble, vibration, and etc.) is about to be transmitted to the ribbon itself. The shock-absorption by the ribbon microphone frame reduces unnecessary vibration to the ribbon, which results in higher-fidelity output signal generation by the ribbon with a reduction in unwanted noise.
An additional significant advantage of the present invention is an electrically-conductive spring element which conducts an electric output signal from the ribbon to a transformer block, thereby simplifying wiring scheme between the ribbon and a transformer block compared to existing ribbon microphone designs. The electrically conductive spring element operatively connected to one end of a ribbon simplifies the output signal wiring of the ribbon while also being utilized as part of the shock-absorbing apparatus. Because any complicated wiring to the ribbon can be another source of vibration and reduction in fidelity, using the electrically-conductive spring element as a signal path for the electric output signal from the ribbon to a transformer block reduces unwanted vibration and noise for even higher-fidelity electric output signal generation from the ribbon.
Furthermore, an additional benefit of the present invention is related to a fabric screen covering a substantial portion of a ribbon inside a ribbon microphone frame, wherein the fabric screen provides a protective layer for the ribbon from external elements while enabling the ribbon to achieve a good frequency response to sound waves.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
