Patent Application
20090103753
The present invention relates to a column surround-sound speaker, and particularly to a single column surround-sound speaker with multiple speaker unit arrangements.
The current trend in sound reproduction is to use an arrangement of typically four to five loudspeakers. For example, a conventional speaker system includes a front speaker located in proximity to the video image for providing acoustic output based upon a summation signal of the component left and right (L+R) channels of the audio signal. A rear speaker located to the rear of the viewing area provides acoustic output based upon a difference signal, (L−R) or (R−L), between the left and right channels. Left and right speakers located to the respective left and right sides of the viewing area. The left and right channels speakers reproduce a difference signal, (L−˜R) or (R−˜L), where ˜ is a gain which may vary or may be a value fixed between zero and unity. Output to the left and right speakers is band limited to substantially filter out frequency components below a predetermined threshold. A bass speaker may also be provided to output the low frequency components of a (L+R) summation signal. The (L+R) summation signal input to the front speaker assists in localizing dialog to the video image. The (L−˜R) or (R−˜L) difference signal substantially removes dialog sound so that the side and rear speaker output primarily comprises sonic ambience and surround sound effects. Band limiting the left and right speakers further assists in localizing dialog to the video image.
The conventional surround-sound speaker systems as mentioned above usually need four to five speakers located in different positions to reproduce surround sound effects and the positions of these speakers are substantially unchangeable. Therefore, the user needs to arrange space for different speakers in different directions in a room. It is inconvenient and space-wasting for the user. Thus, there is still a demand for providing a space-saving and position changeable surround-sound speaker.
The present invention provides a single column surround-sound speaker with multiple speaker unit arrangements. In one aspect of the present invention, the single column surround-sound speaker includes a hollow pillar with at least three openings formed thereon spirally, at least three full range speakers attached in the openings, a base supporting the hollow pillar, and a sound field reconstructing unit formed within the hollow pillar or the base or outside of the hollow pillar and the base, wherein the sound field reconstructing unit is coupled to the at least three full range speakers.
In another aspect of the present invention, the single column surround-sound speaker includes a hollow pillar with at least three openings formed thereon asymmetrically or symmetrically, at least three full range speakers attached in the openings, a base supporting the hollow pillar, and a sound field reconstructing unit formed within the hollow pillar or the base or outside of the hollow pillar and the base, wherein the sound field reconstructing unit is coupled to the at least three full range speakers. The full range speakers are coupled with each other serially or parallelly. The sound field reconstructing unit includes a digital signal processor and a digital delay circuit.
One advantage of the present invention is that the single column surround-sound speaker can singly achieve surround sound effects.
Another advantage of the present invention is that the size of the single column surround-sound speaker can be greatly decreased because of the compact full-range speaker.
Still another advantage of the present invention is that the single column surround-sound speaker can be placed anywhere in a room with the surround sound effects remained at the same level.
Still another advantage of the present invention is that the single column surround-sound speaker can be convenient to use and position changeable and space-saving for the user.
These and other advantages will become apparent from the following description of preferred embodiments taken together with the accompanying drawings and the appended claims.
The present invention may be understood by some preferred embodiments and detailed descriptions in the specification and the attached drawings below. The identical reference numbers in the drawings refer to the same components in the present invention. However, it should be appreciated that all the preferred embodiments of the invention are only for illustrating but not for limiting the scope of the Claims and wherein:
The invention will now be described with the preferred embodiments and aspects and these descriptions interpret structure and procedures of the invention only for illustrating but not for limiting the Claims of the invention. Therefore, except the preferred embodiments in the specification, the present invention may also be widely used in other embodiments.
The present invention discloses a single column surround-sound speaker with multiple speaker unit arrangements. In one embodiment of the present invention, the speaker unit arrangements may be spiral. In another embodiment of the present invention, the speaker unit arrangements may be asymmetric or symmetric. The single column surround-sound speaker of the present invention achieves surround sound effects with only one column speaker by such speaker unit arrangements and by the 3D sound field reconstruction technique which will be described hereafter.
With reference to
In another embodiment of the present invention, the arrangements of the speaker units may be asymmetric or symmetric without fake speakers. With reference to
With reference to
In order to simulate real sound source, which locates at an arbitrary point in 3D space, the 3D sound field reconstruction technique introduces HRTF (Head Related Transfer Function) database, which was defined as a set of transfer function between sound source to two ears of a human head. The HRTF depends on the coordinate and frequency of a point of sound source, and also has individual dependency of the listeners. HRTF can be realized as an impulse response of the time domain representation of HRTF referred as HRIR (Head Related Impulse Response). This HRTF or HRIR consists of a complete mathematical model based on acoustic wave theory and actual measurements that have been carried out for huge samples using dummy head microphones and human heads. The theoretical HRTF has several advantages such as suitable characteristics for music reproduction due to its natural and simple frequency response and less computational tasks.
In one embodiment, the real speaker units assembled in the openings on the cylinder may be compact full-range speakers with high performance. For example, a full range loudspeaker has a diaphragm with a voice coil disposed about its perimeter and extending in a gap into which the flux of a rare earth magnet is focused, as disclosed in U.S. Pat. No. 6,654,476 which is incorporated herein by reference. The voice coil may have two or more windings that are connected in parallel. These may be layered on top of one another, so that the impedance of the coil, as well as its depth in the direction of motion, are low. The voice coil is preferably implemented using a polyimide form or bobbin which has patterned lead-in conductors embedded therein to bring power to the perimeter of the coil. The lead-in conductors connect at one end to wire windings wound on the bobbin, and extend at their other end to, or through, an opening located centrally behind the diaphragm, providing a robust ribbon input connection. The ribbon lead-in may be symmetrical, and the central opening further provides an air channel which may, for example, couple to an auxiliary chamber to further enhance the acoustic output. The magnet may be an annular or ring magnet, and it rests on a first, or lower, generally cup-shaped pole piece, that cooperates with a second, or upper generally washer-shaped pole piece to define the flux gap in a region extending around the perimeter of the diaphragm.
Preferably, the upper surface of the washer is inclined radially inward to an edge of diminished thickness, to reduce central mass. This also provides added clearance at the front of the magnet assembly for accommodating the lead-in ribbon in a widely-curved arc without contact, and reduces the length of the central passage to prevent undesirable whistling when the diaphragm is subject to large displacement. The diaphragm may be domed to provide further clearance, and is weighted or mass-loaded by applying a material such as butyl rubber to lower its natural resonant frequency, thus extending its useful response band while providing sharp rolloff at the low end. Loading may be achieved by a sandwich construction, in which one face of the dome is entirely coated, and the rubber layer further extends in a band around the edge of the diaphragm to suspend the diaphragm to its housing. A magnetic fluid is selectively placed in the gap to enhance heat transfer and coil centering. In addition to the aforementioned full range speaker, the speaker units assembled in the openings on the cylinder may be any other kinds of compact full-range speakers known in the art.
Therefore, the single column surround-sound speaker of the present invention utilizes the 3D sound field reconstruction technique to simulate real surround sound and produce treated sound signals from sound sources for the full-range speaker units in multiple arrangements to output toward different directions, so as to achieve surround sound effects with only one surround-sound speaker. Furthermore, the single column surround-sound speaker of the present invention can be placed anywhere in a room with the surround sound effects remained at the same level, and the size of the single column surround-sound speaker can be greatly decreased because of the compact full-range speaker units. Accordingly, the single column surround-sound speaker of the present invention can be convenient to use and position changeable and space-saving for the user.
The foregoing description is a preferred embodiment of the present invention. It should be appreciated that this embodiment is described for purposes of illustration only, not for limiting, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations are included insofar as they come within the scope of the invention as claimed or the equivalents thereof.
