WO2004086812A1 - スピーカシステム用音波案内構造およびホーンスピーカ - Google Patents
スピーカシステム用音波案内構造およびホーンスピーカ Download PDFInfo
- Publication number
- WO2004086812A1 WO2004086812A1 PCT/JP2004/004232 JP2004004232W WO2004086812A1 WO 2004086812 A1 WO2004086812 A1 WO 2004086812A1 JP 2004004232 W JP2004004232 W JP 2004004232W WO 2004086812 A1 WO2004086812 A1 WO 2004086812A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- sound
- path
- sound wave
- branch point
- exit
- Prior art date
Links
- 238000010276 construction Methods 0.000 claims 3
- 238000000034 method Methods 0.000 description 17
- 238000013461 design Methods 0.000 description 15
- 238000010586 diagram Methods 0.000 description 13
- 238000005452 bending Methods 0.000 description 5
- 238000005304 joining Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 238000012937 correction Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/02—Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators
- G10K11/025—Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators horns for impedance matching
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/08—Non-electric sound-amplifying devices, e.g. non-electric megaphones
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/18—Methods or devices for transmitting, conducting or directing sound
- G10K11/26—Sound-focusing or directing, e.g. scanning
- G10K11/28—Sound-focusing or directing, e.g. scanning using reflection, e.g. parabolic reflectors
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/30—Combinations of transducers with horns, e.g. with mechanical matching means, i.e. front-loaded horns
Definitions
- the invention provides a sound wave guide structure for a speaker system for guiding a sound wave along a predetermined path to control the wavefront of the sound wave radiated from the path, and applies the structure to a throat section. Horn speaker.
- an inner member is provided in a housing having a slit-shaped outlet opening, and in a sound wave guide path formed around the inner member, all shortest paths from the inlet opening to the outlet opening have substantially the same length. Some are trying. As a result, the phase of the sound wave radiated from the exit aperture is made entirely the same, and the wavefront (the in-phase plane) is made to be a rectangular plane (for example, US Pat. No. 5,163,167). Refer to the specification).
- the radiated wavefront it is difficult to design the radiated wavefront to have a shape other than a rectangular shape, for example, concave curved surface ⁇ convex curved surface, and it is necessary to install special members called internal members. This increases the number of parts and complicates the manufacturing process. Moreover, such a structure itself is very complicated.
- a sound wave guide structure for a speaker system includes a sound path communicating from an entrance opening to an exit opening, and the sound path extends from the entrance opening to the exit opening.
- a plurality of sound guide paths are formed from the inlet opening to the outlet opening.
- each sound wave guide path is a path from the entrance opening to the exit opening while passing through each branch point. Since the sound wave propagates so as to pass through each branch point, the propagation path of the sound wave is determined uniformly, and all the propagation paths of the sound wave can be predicted almost completely. Therefore, it is possible to accurately control the wavefront while having a simple structure.
- the plurality of sound guide paths may extend linearly from the entrance opening to the exit opening. Since the sound wave guide path extends linearly, the sound wave can be considered to propagate along the central axis of the path, and the propagation path of the sound wave can be grasped more accurately.
- a surface including the entire central axis of the plurality of sound wave guiding paths may be a flat surface, a curved surface, or a curved surface.
- the planar shape facilitates the production of the sound guide structure for the speaker system.
- a sound path can be formed by joining two parts that are symmetrical with the plane as a joint surface at the joint surface.
- the sound guide structure for the speaker system can be reduced in size as a whole.
- the outlet opening may be formed in a slit shape, and at each branch point of the sound path, the sound wave guide path may be branched in a longitudinal direction of the slit. .
- the slit-shaped outlet opening may extend linearly.
- the slit-shaped outlet opening may be curved and extended in a convex curve shape.
- the slit-shaped outlet opening may be curved and extended in a convex arc shape. Further, in the above-mentioned sound guide structure for a speaker system, the slit-shaped outlet opening may be curved and extended in a concave curve shape.
- the slit-shaped outlet opening may be curved and extended in a concave arc shape.
- a sound guide path having an outlet at a position closer to the center of the slit-shaped outlet opening may have a shorter path length.
- a sound guide path having an outlet at a position closer to the center of the slit-shaped outlet opening may have a longer path length.
- the path length is a length along a line passing through a center point in a width direction of the path immediately after the branch point. More precise control of the wavefront.
- At least a part of at least one of the plurality of sound guide paths may extend in a curved shape. It can be designed to be impossible.
- the height is the largest at an intermediate portion between the entrance opening and the exit opening of the sound path.
- the height of the sound guide path is If the largest point is at or near the branch point of the sound path, it is possible to prevent the branch point of the path from becoming extremely wide.
- the sound path may have a junction where the branched sound paths merge.
- the above-described sound wave guiding structure for a speaker system can be applied to a throat portion of a horn speaker.
- FIGS. 1A and 1B are diagrams of a phone speaker employing a sound wave guide structure for a speaker system of the present invention in a throat portion, wherein FIG. 1A is a front view, FIG. 1B is a right side view, and FIG. .
- FIG. 2 is a view of the horn speaker of FIG. 1 as viewed vertically from obliquely below.
- FIG. 3 is a sectional view taken along line AA in FIG. 1 (a).
- Fig. 4 is a plan view of the horn speaker.
- (A) shows a horn speaker configured such that the entire central axis of the sound wave guide path is included in the curved surface, and (b) shows the entire central axis of the sound wave guide path.
- Horn speakers configured to be included in the bent surface are shown respectively.
- FIG. 5 is a longitudinal sectional view of a throat portion of a horn speaker having various types of sound paths.
- FIG. 6 is a diagram showing a usage example of a horn speaker adopting the present invention.
- FIG. 7 is a longitudinal sectional view of the horn speaker.
- FIG. 8 is a schematic diagram of a sound path to show an example of a method of designing the sound path.
- FIG. 9 is a longitudinal sectional view of a throat portion having a sound wave guiding structure.
- FIG. 10 is a schematic diagram of a sound path for explaining a modification of the form of the sound path as shown in FIGS. 9 (b) and 9 (c).
- FIG. 11 is a longitudinal sectional view of the horn speaker.
- FIG. 12 is a view of the horn speaker as viewed from obliquely below and longitudinally.
- FIG. 13 is a diagram showing one side when the sound path in horn speed is divided by a vertical section.
- Figure 14 is a characteristic diagram obtained by measuring the directivity of three adjacent horn speakers.
- FIGS. 1-10 An embodiment of the present invention will be described with reference to the drawings.
- a basic structure of a horn speaker in which a sound guide structure for a speaker system according to an embodiment of the present invention is adopted in a mouth portion will be described with reference to FIGS.
- FIG. 1 is a diagram of the horn speaker 1, (a) is a front view, (b) is a right side view, and (c) is a plan view.
- the horn speaker 1 has a left-right symmetric and up-down symmetric structure.
- the horn speaker 1 mainly includes a slot part 10 and a horn part 21.
- the phone speaker 1 of this type is used with a driver unit attached, and can obtain a constant directivity over a relatively wide frequency range.
- a circular flange 22 is provided at the base end of the throat portion 10.
- the flange 22 is a portion for mounting the driver unit.
- the tip of the throat section 10 is continuous with the base end of the horn section 21.
- a vertically long rectangular slit appears at a substantially central portion thereof, and this slit is an outlet opening 12 of the throat portion 10.
- FIG. 2 is a view of the horn speaker 1 as viewed from obliquely below and longitudinally.
- the cut surface shown in FIG. 2 is a cross section taken along line AA in FIG. 1 (a).
- FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1 (a).
- the tip of the horn 21 originally shown on the left side of the figure is omitted.
- a flange 22 is provided at the base end of the throat portion 10, and an inlet opening 11 is formed here. Further, the above-mentioned slit-shaped outlet opening 12 is formed at the tip of the throat portion 10, where the throat portion 10 is continuous with the horn portion 21. A sound path is formed from the base end to the front end of the throat portion 10.
- This sound path is composed of a branch path branched into a plurality of stages. Each path is linear It extends, and the sound path as a whole has a branch structure in which tree branches extend to the tip while branching.
- the sound path branches off into two paths at the base end (entrance opening 11). Each of the branched paths further branches into two at the approximate center point between the base end and the tip. Each of the branched paths repeats branching toward the distal end, and finally leads to the slit-shaped outlet opening 12 at the distal end. At each branch point, the path branches in the longitudinal direction of the slit-shaped outlet opening 12.
- a branch point where the first route branches into the second route is formed in five stages from the base end to the tip end.
- the sound path has 32 outlets t1 to t32 at the tip.
- 32 paths (sound guide paths) from the base end to the tip are formed.
- the center axis L1 of the horn speaker 1 coincides with the front and rear direction of the horn speaker 1.
- the outlet opening 12 at the front end has a slit shape extending vertically in FIG.
- Each of the routes 2 and 3 (each route from the entrance opening 11 at the base end to the exit opening 12 at the tip end) includes 5 branch points.
- the first branch point is a branch point at the base end of the throat section 10.
- Each path branched at the branch point Di is inclined approximately 30 degrees up and down with respect to the center axis L1 of the horn speaker 1.
- the path branches so as to make an inclination of about 30 degrees up and down with respect to the center axis L1.
- the path branches so as to make a vertical inclination of about 30 degrees with respect to the center axis L1.
- the path branches so as to be inclined approximately 30 degrees up and down with respect to the center axis L1.
- the path also branches so as to make an inclination of about 30 degrees up and down with respect to the center axis L1.
- the first branch point D1 is at one place
- the second branch point D2 is at two places
- the third branch point D3 is at four places
- the fourth branch point D3 is at
- the point D4 is formed at eight places and the fifth branch point D5 is formed at 16 places, forming a total of 31 branch points.
- FIG. 3 only some of them are denoted by reference numerals.
- the broken line L2 in FIG. 3 schematically shows the wavefront of the sound wave immediately after being emitted from the outlet opening 12 (32 through 132).
- the central axis of this path also has a similar branch structure.
- the central axis of the route 32 (sound guide route) is included in a plane. This plane corresponds to the plane of FIG.
- the shape of the throat portion 10 can be made planar, and the manufacturing becomes easy.
- two parts having the shape shown in Fig. 2 can be manufactured, and by joining these two parts, one horn spur can be constructed. Since parts having the same shape can be used in this way, the cost of the mold can be reduced. Also, not the whole horn speaker but only the throat part can be constructed by joining two parts of the same shape.
- the horn speaker 1 shown in FIGS. 1 to 3 is configured so that the entire central axis of the route 32 (sound guide route) is included in a certain plane.
- the entire central axis of these paths may be included in a curved surface or a curved surface.
- FIGS. 4A and 4B are plan views of the horn speakers 31 and 33 configured as described above.
- FIG. 4A illustrates the horn speaker 31 configured such that the entire central axis of the path is included in the curved surface
- FIG. Horn speakers 32 configured such that the entire central axis is included in the bent surface are shown.
- broken lines L32 and L34 indicate surfaces including the center axis of the path.
- the hornsby in Figs. The only difference from force 1 is that the entire central axis of the path (acoustic guide path) is configured to be included in a plane, or to be included in a curved or bent surface.
- the other structures of the horn speakers 31 and 33 in FIG. 4 are all the same as those of the horn speakers 1 in FIGS.
- the entire length of the throat portion can be shortened by configuring the entire central axis of the path to be included in the curved surface or the curved surface.
- the entrance opening 11 of the sound path in the throat portion is directed substantially in the same direction as the exit opening 12 as shown in the horn speakers 31 and 33 shown in FIG. , 33, so that it does not protrude to the rear, contributing to the miniaturization of the overall speed system.
- FIG. Figs. 5 (a) to 5 (c) are longitudinal sectional views of the throat portion having hospice forces of 40, 50, and 60, respectively.
- the sound path formed in the throat part shown in FIG. 5 (a) is formed so that the path lengths of all the paths are substantially the same as the sound path shown in FIG. That is, at each of the branch points D1, D2, and D3, the-, 1 path branches to the 2 path.
- a broken line L4 in FIG. 5 (a) schematically shows the wavefront of the sound wave immediately after being emitted from the outlet opening 42 (the outlets tl to t8 of 8).
- the sound path formed in the throat section shown in FIG. 5 (b) is configured such that the path having an exit nearer to the center of the slit-shaped exit opening 52 has a shorter path length. That is, the path length from the inlet opening 51 to the outlets t4 and t5 is the shortest, and the path length from the inlet opening 51 to the outlets tl and t8 is the longest.
- Figure The vertical position of the second branch point D2 in the middle is substantially the same as the vertical position of the outlets t4 and t5.
- the wave surface (the in-phase surface of the sound wave) at the slit-shaped outlet opening 52 has a convex curved surface shape.
- a broken line L5 in FIG. 5B schematically shows the wavefront of the sound wave immediately after being emitted from the outlet opening 52 (eight outlets t1 to t8).
- the sound path formed in the throat portion shown in FIG. 5 (c) is configured such that a path having an exit closer to the center of the slit-shaped exit opening 62 has a longer path length. That is, the path length from the inlet opening 61 to the outlets t4 and t5 is the longest, and the path length from the inlet opening 61 to the outlets i l and t8 is the shortest.
- the vertical position of the second branch point D2 in the figure is substantially the same as the vertical position of the outlets tl and t8.
- the wavefront (the in-phase surface of the sound wave) at the slit-shaped outlet opening 62 has a concave curved surface.
- a broken line L6 in FIG. 5C schematically shows the wavefront of the sound wave immediately after being emitted from the outlet opening 62 (eight outlets U to t8).
- the wavefront can be controlled to various shapes by the structure of the branch path constituting the sound path. In other words, it is possible to easily control the curvature of the wavefront and the directional angle.
- Fig. 6 shows an acoustic system in which a plurality of (9) horn speakers 71 to 79 are arranged adjacent to each other and arranged in a line. In this system, there are a part where the horn speakers are arranged linearly and a part where the horn speakers are arranged curvedly. As the horn speakers 71 to 73 and 77 to 79 arranged linearly, horn speakers having a slot portion having a structure as shown in FIG. 5A are used. A horn speaker having a throat portion having a structure as shown in Fig.
- horn speakers 71 to 73 and 77 to 79 emit sound waves having a flat wavefront
- horn speakers 74 to 76 emit sound waves having a convexly curved wavefront.
- a wavefront substantially similar to the arrangement of the horn speakers 71 to 79 as shown by a broken line L7 in FIG. 6 can be obtained from the entire acoustic system constituted by the horn speakers 71 to 79. As a result, phase interference between adjacent horn speakers, particularly in a high frequency band, can be avoided.
- FIG. 7 is a longitudinal sectional view of the horn spike 90. However, the tip portion of the horn portion 21 originally shown on the left side of the figure is omitted.
- the horn speaker 90 has substantially the same structure as the horn speaker 1 shown in FIGS. 1 to 3, but differs only in the form of branching of the sound path in the throat section 10.
- the branch form of the sound path of the throat section 10 of the horn speaker 90 is slightly more complicated than the branch form of the sound path shown in FIG. That is, a branch point D11 is further formed between the branch point D1 and the branch point D2. In the middle of the path from the branch point D11 toward the inside of the horn speaker 90 to the branch point D3, there is formed a merge point D12 where the paths branched at the branch point D11 merge. The route merges at the junction D12 and then branches again in two directions. In other words, point D12 is both a junction and a junction.
- a branch point D13 is also formed between the branch point D2 and the branch point D3.
- One of the routes branched at the branch point D13 merges with the other route at the branch point D3, and the other merges with the other route at the branch point D4.
- the inner two of the four junctions D3 formed at the four locations are both junctions and junctions.
- Two of the eight junctions D4 formed at eight locations are both junctions and junctions.
- the horn loudspeaker 90 is configured as described above. Even if the horn speaker 90 passes through any of the paths that branch and merge on the way from the entrance opening 11 to each of the exits t1 to t32, the path lengths thereof are all substantially equal. Therefore, when the driver unit is mounted on the flange 22 and driven, sound waves are radiated in the same phase from the entire slit-shaped outlet opening 12.
- FIG. 8 is a schematic diagram of a sound path for illustrating an example of a method of designing the sound path.
- FIG. 8A shows a slit shape in which the outlet opening 112 extends linearly.
- B shows the sound path of the sound guide structure in which the outlet opening 122 is shaped like a slit that extends and curves in a convex curve, and
- c shows the sound path of the sound guide structure in which the outlet opening 132 is concave.
- the sound paths of the sound guide structure in the form of a slit that curves and extends in a curved manner are shown.
- the outlet opening 122 in (b) has a slit shape that curves and extends in a convex arc shape
- the outlet opening 132 in (c) curves and extends in a concave arc shape. It has a slit shape.
- the positions of the outlets at both ends (outlet tl and outlet t5) in the outlet opening 112 are determined.
- a slit-shaped outlet opening 112 is defined along a straight line S1 connecting the outlet tl and the outlet ⁇ 5.
- the position of the exit t3 is determined on the bisecting point of the straight line S1 connecting the exit t1 and the exit t5.
- the position of the exit t 2 is determined on the bisecting point of the straight line connecting the exit t l and the exit t 3.
- the position of the exit t4 is determined on the bisecting point of the straight line connecting the exit 13 and the exit 15.
- the five outlets t l, t 2, ⁇ .3, t4, and t 5 are positioned at equal intervals on the straight line S1.
- the position of the second branch point D2 is determined on the intersection of the normal line n2 passing through the exit t2 and orthogonal to the straight line S1 and the straight line connecting the branch point D1 and the exit U.
- the position of the branch point D3 (the top third branch point D3) is determined.
- the third branch point is located on the intersection of the normal 1123 passing through the bisecting point of the straight line connecting the exit 12 and the exit 13 and orthogonal to the straight line S1, and the straight line connecting the branch point D2 and the exit 13. Determine the location of D3 (third junction D3, second from top).
- a third path and a fourth path extending from the branch point D1 to the second branch point]) 2 then bending at the branch point D2, and linearly extending from the branch point D2 to the exit t3. is there.
- the second route and the third route merge at the exit t2.
- the path 4 can be defined in the same manner as in the area above the normal n3.
- the outlet opening 112 Since the outlet opening 112 has a slit shape extending linearly and the eight sound guide paths have the same path length, the wavefront of the sound wave radiated from the outlet opening 112 is straight.
- the design method of the acoustic wave guide structure in which the outlet opening 112 has a slit shape extending linearly has been described with reference to FIG.
- a convex arc-shaped outlet opening 122 is defined.
- the outlet opening 122 in FIG. 8B has a convex arc shape with a central angle of 15 degrees. Then, the positions of the exits at both ends (exit U and exit t5) in the exit opening 122 are determined. Exit tl and exit t5 are connected by an arc S2.
- the position of the exit t3 is determined on the bisecting point of the arc S2 connecting the exit tl and the exit t5.
- the position of exit ⁇ is determined on the bisecting point of the arc connecting exit tl and exit t3.
- the position of the exit M. is determined on the bisecting point of the arc connecting the exit 13 and the exit 15. As described above, five outlets tl, t2, t3, t4, and t5 are positioned at equal intervals on the arc S2.
- the position of the first branch point D1 is determined at an arbitrary point on the normal line n3 that passes through the exit t3 and is orthogonal to the arc S2.
- the position of the second branch point D2 is determined on the intersection of the normal line ⁇ 2 passing through the exit t2 and orthogonal to the arc S2, and the straight line connecting the branch point D1 and the exit U.
- the third branch Determine the location of point D3 (the third highest branch point D3).
- the third branch point is located on the intersection of the normal line n23 passing through the bisecting point of the arc connecting the exit t2 and the exit t3 and orthogonal to the arc S2, and the straight line connecting the branch point D2 and the exit t3.
- a fourth path to The second route and the third route merge at the exit t2.
- the route 4 can be defined in the same manner as in the area above the normal n3.
- the outlet opening 122 has a slit shape that is curved and extended in a convex arc shape, and the length of the eight sound wave guide paths is the same, the wavefront of the sound wave radiated from the outlet opening 122 is Like the shape, it becomes a convex arc shape.
- a concave arc-shaped outlet opening 132 is defined.
- the outlet opening 132 in FIG. 8C has a concave arc shape with a central angle of 15 degrees. Then, the positions of the exits (exit tl and exit t5) at both ends in the exit opening 132 are determined. Exit tl and exit are connected by arc S3.
- the position of the exit t3 is determined on the bisecting point of the arc S3 connecting the exit U and the exit t5.
- the position of the exit t2 is determined on the bisecting point of the arc connecting the exit U and the exit t3.
- the position of the exit t4 is determined on the bisecting point of the arc connecting the exit ⁇ 3 and the exit t5. As described above, five exits U, t2, t3, t4, and t5 are positioned at equal intervals on the arc S3.
- the position of the first branch point D1 is determined at an arbitrary point on the normal line n3 that passes through the exit t3 and is orthogonal to the arc S3.
- the position of the second branch point D2 is determined on the intersection of the normal line n2 passing through the exit t2 and orthogonal to the arc S3 and the straight line connecting the branch point D1 and the exit tl.
- the exit t The second route to reach the second point, and after extending from the branch point D1 to the second branch point D2, bending at the branch point D2, and extending from the branch point D2 to the second third branch point D3 from the top
- the second route and the third route merge at the exit t2.
- the route 4 can be defined in the same manner as in the area above the normal n3.
- the outlet opening 132 has a slit shape curved and extended in a concave arc shape, and the eight sound wave guide paths have the same path length, the wavefront of the sound wave radiated from the outlet opening 132 is Like the shape, it has a concave arc shape.
- the sound path where each branch point is set by the design method shown in Fig. 8 is closer to the exit from the entrance opening (in the example of Fig. 8 near the branch point D1) than the sound path where the branch points are set at other positions.
- the path length to the opening becomes shorter.
- the design method shown in Fig. 8 is a design method that minimizes the path length from the entrance opening to the exit opening. Therefore, if the horn spike that applies the sound path designed by this design method to the throat section is used in combination with another speaker (for example, a woofer), the time delay with respect to the other speaker is minimized. In other words, when this time delay is corrected by a delay device or the like, the correction time (for example, the delay time set in the delay device) can be minimized.
- FIG. 9 is a longitudinal sectional view of the throat portions 111 and 110 having the acoustic wave guiding structure, and is a diagram corresponding to, for example, a longitudinal sectional view of the slot portion 10 in FIG.
- the sound path structure of the throat portions 110 and 111 shown in FIGS. 9 (a), (b) and (c) is basically the same as the structure shown in FIG. 8 (b). Therefore, the outlet openings 142 and 143 have a slit-like shape that is curved and extended in a convex arc shape.
- FIG. 9 (a) shows a vertical cross section of the throat portion 110, and the dashed line in this figure is the center line of the sound wave guide path.
- the shape of this center line is designed in the same manner as described with reference to FIG. 8 (b).
- a sound wave guide path having a predetermined width is formed in the throat portion 110.
- Figure 9 shows the width of the route exaggerated and wide.
- a sound wave propagates along each path from the branch point D1 to the exits tl, t2, t3, t4, and 15.
- the path length of each path is the length along the center line indicated by the dashed line.
- the time required for the sound wave to reach the outlets il, i2, ⁇ 3, ⁇ 4 from the branch point D1 can be considered to be equal to the time obtained by dividing the path length by the speed of sound. Therefore, in the throat section 110 of FIG. 9A, the time for the sound wave to propagate from the branch point D1 to the exits tl, t2, t3, t4, and t5 is the same, regardless of which path the sound wave propagates.
- the throat section 110 shown in FIG. 9A there are two routes from the branch point D1 to the branch point D2, and four routes from the branch point D2 to the branch point D3.
- the width of the path from the branch point D1 to the branch point D2 is constant, and the width of the path from the branch point D2 to the branch point D3 is also constant. Also, the width of the path from the branch point D1 to the branch point D2 and the path from the branch point D2 to the branch point D3
- the width of the road is the same. Therefore, the total width of the path from the branch point D2 to the branch point D3 is twice the total width of the path from the branch point D1 to the branch point D2. That is, at the branch point D2, the sum of the route widths is rapidly increased. This indicates that the propagation of smooth sound waves may be hindered at the branch point D2. This problem also occurs at branch point D3.
- the time required for the sound wave to exit from the branch point D1 and reach 345 can be considered to be equal to the time obtained by dividing the path length by the speed of sound.
- the throat section 111 shown in FIG. 9 (c) is the same as the throat section 111 shown in FIG. 9 (b).
- the two-dot chain line in FIG. 9C indicates the center line of the path in the throat 111.
- the two-dot chain line passes through the center point in the width direction of the route immediately after each of the branch points D1, D2, and D3.
- the path length of each path from the branch point D1 to each of the exits tl, 12, t3, t4, is the length along this two-dot chain line, that is, the width of the path immediately after the branch points D1, D2, D3. Can be considered to be the length along a line passing through the center point of the direction. Assuming that the sound wave propagates along the two-dot chain line, the propagation time of the sound wave from the branch point D1 to each exit tl, t2, t3, t4, t5 can be estimated. In the throat portion 111 of FIG.
- the length of the two-dot chain line from the branch point D1 to the exit t3 is shorter than the length of the two-dot chain line from the branch point D1 to the exit U.
- the path lengths of the respective paths are not the same. Therefore, the wavefront of the sound wave radiated from the outlet opening 143 Is not the same as the shape of the convex arc of the outlet opening 143.
- the shape of the sound path as shown in Figs. 9 (b) and 9 (c) must be slightly modified. Just fine.
- FIG. 10 is a schematic diagram of a sound path for explaining this modification.
- the sound guide structure shown in FIG. 10 is a sound guide structure in which the outlet opening is shaped like a slit that extends and curves in a convex arc shape, as shown in FIG. 8 (b).
- each path is configured to extend linearly from one branch point to the next branch point.
- the location of the branch point D1 and the exits tl, t2, t3, t4, and t5 in Fig. 10 (a) are the same as the location of the branch point D1 and the exits tl, t2, t3, t4, and t5 in Fig. 8 (b).
- the location of the branch points 1) 2, D3 in Fig. 10 (a) is different from the location of the branch points D2, D3 in Fig. 8 (b).
- the positions of branch points D2 and D3 in Fig. 10 (a) are located outside of the sound wave guide structure in Fig. 8 (b).
- each of the outlets tl, t2, t3, ⁇ ⁇ It is possible to make the length of each route up to t5 the same.
- the throat must be designed so that the shape of the wavefront of the sound wave radiated from the outlet opening is the same as the shape of the convex arc of the outlet opening, and that the sound wave can be smoothly propagated at each branch point.
- each path is configured so that it does not necessarily extend linearly from one branch point to the next, but also extends in a curved manner. I have.
- the route extends linearly. From the upper second branch point D2 to the uppermost third branch point D3, and from the lower second branch point D2 to the lowermost third branch point D3, the route is Extends linearly. Between the upper second branch point D2 and the second third branch point D3 from the top, and between the lower second branch point D2 and the second third branch point D3 from the bottom.
- the route extends in a curved (S-shaped) manner. From the top third junction D3 to the exit tl, from the top third junction 3) From 3 to the exit t3, from the bottom third junction D3 to the exit The path extends linearly up to t3 and from the bottom third junction D3 to the exit t5.
- the path extends curvilinearly (S-shaped).
- the locations of the branch points D1, D2, D3 and the exits tl, t2, t3, t4, t5 in Fig. 10 (b) are determined by the branch points D1, D2, D3 and the exits tl, t2, t3, It is the same as the arrangement position of t4 and t5. Based on the shape of the acoustic wave guide structure in Fig.
- each exit tl, t2, t3, U , t5 can be the same.
- the throat should be designed so that the shape of the wavefront of the sound wave radiated from the outlet opening is the same as the shape of the convex arc of the outlet opening, and that the sound wave can be smoothly propagated at each branch point. Becomes possible.
- the sound path structure shown in FIG. 10 (a) has a point where the path is sharply bent.
- the path is sharply bent at the branch point D2.
- the structure shown in FIG. 10 (b) is less likely to cause unnecessary sound wave reflection on the sound path. That means less energy loss.
- FIG. 11 is a longitudinal sectional view of the horn speaker 100.
- the notation in FIG. 11 is the same as that of the horn speaker 1 in FIG.
- FIG. 12 is a view of the horn speaker 100 as viewed from obliquely below by cutting it longitudinally.
- the notation in FIG. 12 is the same as that of the horn speaker 1 in FIG.
- the horn loudspeaker 100 in Figs. 11 and 12 has a part of the path curved (S-shaped) in order to prevent a sharp bend point in the path. ) It has a sound path structure designed so that it extends and the length of each path is approximately the same.
- a broken line L102 in FIG. 11 schematically shows the wavefront of a sound wave immediately after being emitted from a slit-shaped outlet opening curved in a convex arc shape.
- the shape of the wavefront L102 is a convex arc, similarly to the shape of the outlet opening.
- FIGS. 13A and 13B are diagrams showing one side when the sound path of the horn speaker 100 of FIGS. 11 and 12 is divided by a longitudinal section, where FIG. FIG. The sound path is formed as a space in the throat part of the Horn Spee force, and this is shown in Fig. 13 as a solid model.
- the height of the path at the second branch point D2 is the largest.
- the height gradually decreases from the branch point D2 toward the entrance opening 151.
- the height gradually decreases from the branch point D2 toward the outlet opening 152.
- the reason why the height of the route is particularly increased at the branch point D2 in this way is to reduce the width of the route at this point (branch point D2).
- the interference at that part especially at high frequencies, will increase, and the energy loss will increase.
- the route width is widened at a point where the direction of the route changes, such as a branch point, the tendency becomes remarkable.
- the height of the path of the horn speaker 100 from the entrance opening to the exit opening is substantially constant, the path width at the branch point D2 becomes too wide. Therefore, as shown in FIG. 13, the height of the route at the branch point D2 was particularly increased.
- a branch point that changes the direction of the path is formed at an intermediate portion between the entrance opening 151 of the sound path (near the branch point D1 in the example of FIG. 13) and the exit opening 152. Therefore, the sound path is not limited to the branch point, but it is effective if the sound path is configured so that the height of the path is the highest in the middle of the sound path entrance opening 151 and the exit opening 152.
- FIG. 14 is a characteristic diagram obtained by measuring the directivity of three horn loudspeakers according to the present invention with a directional angle of 20 degrees adjacent to each other.
- the radial axis indicates the sound pressure level.
- three horn loudspeakers were placed adjacent to each other by 20 degrees in different directions. In other words, one of the three horn speakers was placed so as to face the front (0 degree direction), and the other two were placed so as to face the directions of 120 degrees and 20 degrees. .
- the signal for measurement is a noise signal having a frequency component having a width of 1 to 3 octaves with a center frequency of 500 Hz. The same signal was supplied to the three horns.
- the broken line in FIG. 14 is a characteristic curve when the horn speaker arranged so as to face the front direction is driven alone.
- the dashed line points to the direction of 120 degrees • This is the characteristic curve when the placed horn speaker is driven independently.
- the solid line is the characteristic curve when these three phone speakers are driven simultaneously.
- the characteristic curve shown by the solid line shows a substantially flat sound pressure distribution (the sound pressure is proportional to the sound pressure in the front direction) in an angle range of about 60 degrees centered on the front direction. Sound pressure distribution such that the drop falls within 6 dB).
- valleys in the directions that are the boundaries of the angle range covered by each horn speaker 100 are recognized. Absent.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Signal Processing (AREA)
- Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
- Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2005504109A JP4351209B2 (ja) | 2003-03-25 | 2004-03-25 | スピーカシステム用音波案内構造体及びこれをスロート部として用いたホーンスピーカ |
CN200480008207.8A CN1765148B (zh) | 2003-03-25 | 2004-03-25 | 扬声器系统用声波导向结构及喇叭扬声器 |
US10/550,318 US7735599B2 (en) | 2003-03-25 | 2004-03-25 | Sound wave guide structure for speaker system and horn speaker |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003-082899 | 2003-03-25 | ||
JP2003082899 | 2003-03-25 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2004086812A1 true WO2004086812A1 (ja) | 2004-10-07 |
Family
ID=33094933
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2004/004232 WO2004086812A1 (ja) | 2003-03-25 | 2004-03-25 | スピーカシステム用音波案内構造およびホーンスピーカ |
Country Status (4)
Country | Link |
---|---|
US (1) | US7735599B2 (ja) |
JP (1) | JP4351209B2 (ja) |
CN (1) | CN1765148B (ja) |
WO (1) | WO2004086812A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2018513616A (ja) * | 2015-03-31 | 2018-05-24 | ボーズ・コーポレーションBose Corporation | 指向性音響デバイス |
US10034071B2 (en) | 2009-09-11 | 2018-07-24 | Bose Corporation | Automated customization of loudspeakers |
US10491990B2 (en) | 2018-03-08 | 2019-11-26 | Jvckenwood Corporation | Throat and speaker system |
Families Citing this family (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7177437B1 (en) | 2001-10-19 | 2007-02-13 | Duckworth Holding, Llc C/O Osc Audio Products, Inc. | Multiple aperture diffraction device |
US8718310B2 (en) | 2001-10-19 | 2014-05-06 | Qsc Holdings, Inc. | Multiple aperture speaker assembly |
GB2449913A (en) * | 2007-06-07 | 2008-12-10 | Turbosound Ltd | Loudspeaker horn with passages that subdivide |
US8199953B2 (en) * | 2008-10-30 | 2012-06-12 | Avago Technologies Wireless Ip (Singapore) Pte. Ltd. | Multi-aperture acoustic horn |
FI20090218A0 (fi) | 2009-05-29 | 2009-05-29 | Aura Audio Oy | Bassokaiuttimen rakenne |
US8761425B2 (en) | 2010-08-04 | 2014-06-24 | Robert Bosch Gmbh | Equal expansion rate symmetric acoustic transformer |
US8588450B2 (en) | 2010-08-04 | 2013-11-19 | Robert Bosch Gmbh | Annular ring acoustic transformer |
KR101802239B1 (ko) * | 2011-06-14 | 2017-11-29 | 삼성전자주식회사 | 스피커 장치 |
US8488826B2 (en) * | 2011-06-23 | 2013-07-16 | Thomas J. Danley | Horn enclosure for combining sound output |
US8925478B2 (en) * | 2012-05-01 | 2015-01-06 | Curtis E. Graber | Directional isophasic toroidal whistle |
US8798303B2 (en) * | 2012-10-22 | 2014-08-05 | Jazz Hipster Corporation | Horn amplifier |
US8887862B2 (en) * | 2013-03-15 | 2014-11-18 | Bag End, Inc. | Phase plug device |
CN203872335U (zh) * | 2014-01-09 | 2014-10-08 | 唐永均 | 一种扬声器及其声波分压导向器 |
US9282398B2 (en) | 2014-03-19 | 2016-03-08 | Dana Monroe | Speaker system having wide bandwidth and wide high-frequency dispersion |
CN103929693A (zh) * | 2014-05-04 | 2014-07-16 | 赵春宁 | 声波传导装置 |
KR101574794B1 (ko) | 2014-08-26 | 2015-12-04 | 김태형 | 스피커용 입체 음향 가이드, 및 이를 구비한 스피커 및 스피커 시스템 |
US9392358B2 (en) | 2014-10-28 | 2016-07-12 | Robert Bosch Gmbh | Waveguide for shaping sound waves |
KR101510821B1 (ko) * | 2015-01-08 | 2015-04-16 | (주)진명아이앤씨 | 스피커용 혼 |
US9571923B2 (en) | 2015-01-19 | 2017-02-14 | Harman International Industries, Incorporated | Acoustic waveguide |
KR101634279B1 (ko) * | 2015-03-19 | 2016-07-08 | 김태형 | 스피커용 입체 음향 가이드, 및 이를 구비한 스피커 |
CN105244019A (zh) * | 2015-10-27 | 2016-01-13 | 刘善延 | 一种球面声波转成柱面声波的声学波导 |
WO2017124068A1 (en) | 2016-01-14 | 2017-07-20 | Harman International Industries, Inc. | Two-way loudspeaker with floating waveguide |
WO2017169886A1 (ja) * | 2016-03-31 | 2017-10-05 | ソニー株式会社 | 音響管および音響再生装置 |
USD814441S1 (en) * | 2016-05-16 | 2018-04-03 | Scott Hanna | Loudspeaker horn |
CN106454648B (zh) * | 2016-07-15 | 2019-07-02 | 南京大学 | 一种声波导 |
CN106531147A (zh) * | 2016-12-30 | 2017-03-22 | 上海孩子国科教设备有限公司 | 声音加强设备、语音加强助记设备及方法 |
NL2019480B1 (en) * | 2017-09-04 | 2019-03-11 | Alcons Audio Bv | A loudspeaker with a wave front shaping device |
KR102614578B1 (ko) * | 2019-09-06 | 2023-12-18 | 삼성전자주식회사 | 음향 출력 장치 및 이를 포함하는 디스플레이 장치 |
US11202144B2 (en) * | 2020-01-13 | 2021-12-14 | Brian Michael Coyle | Sound directing framework |
US11445303B2 (en) | 2020-10-16 | 2022-09-13 | Harman International Industries, Incorporated | Omnidirectional loudspeaker and compression driver therefor |
US11682378B2 (en) * | 2020-12-16 | 2023-06-20 | Signal Essence, LLC | Acoustic lens for safety barriers |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5163167A (en) * | 1988-02-29 | 1992-11-10 | Heil Acoustics | Sound wave guide |
Family Cites Families (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1871243A (en) * | 1931-08-15 | 1932-08-09 | Bell Telephone Labor Inc | Acoustic device |
US2001089A (en) * | 1933-04-07 | 1935-05-14 | Bell Telephone Labor Inc | Horn |
US2203875A (en) * | 1937-04-30 | 1940-06-11 | Rca Corp | Loud-speaker |
US2684724A (en) * | 1948-10-01 | 1954-07-27 | Bell Telephone Labor Inc | Sound wave refractor |
US4091891A (en) * | 1973-01-17 | 1978-05-30 | Onkyo Kabushiki Kaisha | Horn speaker |
US3957134A (en) * | 1974-12-09 | 1976-05-18 | Daniel Donald D | Acoustic refractors |
US4157741A (en) * | 1978-08-16 | 1979-06-12 | Goldwater Alan J | Phase plug |
US4685532A (en) * | 1986-02-21 | 1987-08-11 | Electro-Voice, Inc. | Constant directivity loudspeaker horn |
US4776428A (en) * | 1987-11-16 | 1988-10-11 | Belisle Acoustique Inc. | Sound projection system |
JP3116119B2 (ja) * | 1989-04-27 | 2000-12-11 | ティーオーエー株式会社 | スピーカ用ホーン |
JPH03204298A (ja) * | 1990-01-05 | 1991-09-05 | Tatsuo Kusano | ホーンスピーカシステム |
KR960011026B1 (ko) * | 1993-07-26 | 1996-08-16 | 대우전자 주식회사 | 텔레비전의 스피커시스템 |
US5900593A (en) * | 1995-07-31 | 1999-05-04 | Adamson; Alan Brock | Loudspeaker system |
US5925856A (en) * | 1996-06-17 | 1999-07-20 | Meyer Sound Laboratories Incorporated | Loudspeaker horn |
CA2349856A1 (en) * | 1998-11-06 | 2000-05-18 | Graham Bank | Loudspeakers comprising a phase uncorrelated diffuse sound source |
US6343133B1 (en) * | 1999-07-22 | 2002-01-29 | Alan Brock Adamson | Axially propagating mid and high frequency loudspeaker systems |
US6581719B2 (en) * | 2000-08-02 | 2003-06-24 | Alan Brock Adamson | Wave shaping sound chamber |
US6668969B2 (en) * | 2001-01-11 | 2003-12-30 | Meyer Sound Laboratories, Incorporated | Manifold for a horn loudspeaker and method |
US7177437B1 (en) * | 2001-10-19 | 2007-02-13 | Duckworth Holding, Llc C/O Osc Audio Products, Inc. | Multiple aperture diffraction device |
US7278513B2 (en) * | 2002-04-05 | 2007-10-09 | Harman International Industries, Incorporated | Internal lens system for loudspeaker waveguides |
AU2002951421A0 (en) * | 2002-09-17 | 2002-10-03 | Krix Loudspeakers Pty Ltd | Constant directivity acoustic horn |
-
2004
- 2004-03-25 CN CN200480008207.8A patent/CN1765148B/zh not_active Expired - Lifetime
- 2004-03-25 JP JP2005504109A patent/JP4351209B2/ja not_active Expired - Lifetime
- 2004-03-25 US US10/550,318 patent/US7735599B2/en active Active
- 2004-03-25 WO PCT/JP2004/004232 patent/WO2004086812A1/ja active Application Filing
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5163167A (en) * | 1988-02-29 | 1992-11-10 | Heil Acoustics | Sound wave guide |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10034071B2 (en) | 2009-09-11 | 2018-07-24 | Bose Corporation | Automated customization of loudspeakers |
JP2018513616A (ja) * | 2015-03-31 | 2018-05-24 | ボーズ・コーポレーションBose Corporation | 指向性音響デバイス |
US10491990B2 (en) | 2018-03-08 | 2019-11-26 | Jvckenwood Corporation | Throat and speaker system |
Also Published As
Publication number | Publication date |
---|---|
JP4351209B2 (ja) | 2009-10-28 |
US7735599B2 (en) | 2010-06-15 |
JPWO2004086812A1 (ja) | 2006-06-29 |
CN1765148A (zh) | 2006-04-26 |
US20070080019A1 (en) | 2007-04-12 |
CN1765148B (zh) | 2010-04-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2004086812A1 (ja) | スピーカシステム用音波案内構造およびホーンスピーカ | |
US9571923B2 (en) | Acoustic waveguide | |
FI120126B (fi) | Menetelmä tasaisen ääniaaltorintaman aikaansaamiseksi sekä tasoaaltosuuntain, kaiutinrakenne ja akustinen linjasäteilijä | |
JP2011520354A (ja) | パッシブな指向性音響放射 | |
US7623670B2 (en) | Waveguide electroacoustical transducing | |
US7510049B2 (en) | Acoustic transformer and method for transforming sound waves | |
CN107293283B (zh) | 一种声学超表面和声波聚焦装置 | |
CN1387386B (zh) | 电声波导系统以及操作声音波导管的方法 | |
US7631724B2 (en) | Sound-wave path-length correcting structure for speaker system | |
US10659872B2 (en) | Speaker apparatus | |
US20130177169A1 (en) | Speaker system | |
JP4916518B2 (ja) | スピーカシステム | |
CN110248292B (zh) | 筒喉以及扬声器系统 | |
JP3446519B2 (ja) | 超音波アレイセンサ | |
RU2001115712A (ru) | Громкоговорители, содержащие диффузный источник звука с некоррелированными фазами | |
JP2010136248A (ja) | スピーカー用ホーンおよびこれを用いたホーンスピーカー | |
WO2021049136A1 (ja) | 音響レンズ及びスピーカシステム | |
WO1998039895A1 (en) | Portable speech communication apparatus with sound channel in swingable flip | |
EP3333846B1 (en) | Acoustic transducer | |
EP2001261A1 (en) | Loudspeaker horn | |
JP6877869B2 (ja) | ステップフロー型ホーン | |
JP2006229786A (ja) | ホーンスピーカ装置 | |
JP7417914B2 (ja) | スピーカー | |
JP2010212150A (ja) | 交差ケーブル | |
JP2012188904A (ja) | パーティション |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): BW GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2005504109 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 20048082078 Country of ref document: CN |
|
122 | Ep: pct application non-entry in european phase | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2007080019 Country of ref document: US Ref document number: 10550318 Country of ref document: US |
|
WWP | Wipo information: published in national office |
Ref document number: 10550318 Country of ref document: US |