Receiver unit having pressure equilibrium structure and compensation structure for low frequency

Abstract

Disclosed is a receiver unit having a pressure equilibrium structure and a compensation structure for a low frequency, including a receiver including a frame, a magnetic circuit, a voice coil, and a diaphragm, an upper casing covering an upper portion and a side surface of the receiver and having a sound insulation hole, and a lower casing attached to a lower surface of the receiver and coupled to the upper casing, wherein a ventilation recess is provided on an outer surface of the upper casing to allow air to flow between an upper space of the upper casing and a lower space of the lower casing, the receiver includes a back hole, and the lower casing includes a duct connecting the back hole and the lower space of the lower casing.

Claims

1. A receiver unit having a pressure equilibrium structure and a compensation structure for a low frequency, the receiver unit comprising: a receiver including a frame, a magnetic circuit, a voice coil, and a diaphragm; an upper casing covering an upper portion and a side surface of the receiver and having a sound insulation hole; and a lower casing attached to a lower surface of the receiver and coupled to the upper casing, wherein an upper surface of the lower casing is closed by the receiver, wherein a ventilation recess is provided on an outer surface of the upper casing to allow air to flow between an upper space of the upper casing and a lower space of the lower casing, wherein the receiver includes a back hole, wherein the lower casing includes a duct path formed by a recess on the upper surface of the lower casing for connecting the back hole and the lower space of the lower casing and for improving low frequency sound by generating resonance in the lower casing.

2. The receiver unit of claim 1, further comprising: at least one acoustic mesh located in the duct path and compensating for a reduction in a low frequency.

3. The receiver unit of claim 2, wherein the acoustic mesh is attached to cover the back hole of the receiver.

4. The receiver unit of claim 2, wherein the acoustic mesh is attached to a lower surface of the lower casing to cover an end of the duct path.

5. The receiver unit of claim 1, wherein the ventilation recess is provided on at least one of an upper surface and a side surface of the upper casing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a view showing a canal-type earphone including a pressure equilibrium means according to the related art;

(2) FIG. 2 is a cross-sectional view of a receiver unit having a pressure equilibrium structure and a compensation structure for low frequency according to an embodiment of the present invention;

(3) FIG. 3 is an exploded perspective view of a receiver unit having a pressure equilibrium structure and a compensation structure for low frequency according to an embodiment of the present invention; and

(4) FIG. 4 is a graph showing comparison of sound pressure by frequency of a general canal-type earphone, a canal-type earphone having a receiver with a ventilation recess, and a canal-type earphone including a ventilation recess and a duct.

DETAILED DESCRIPTION

(5) Hereinafter, the present disclosure will be described in more detail with reference to the drawings.

(6) FIG. 2 is a cross-sectional view of a receiver unit having a pressure equilibrium structure and a compensation structure for low frequency according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of a receiver unit having a pressure equilibrium structure and a compensation structure for low frequency according to an embodiment of the present invention.

(7) A receiver unit having a receiver unit having a pressure equilibrium structure and a compensation structure for low frequency according to an embodiment of the present invention includes a receiver 100 and an upper casing 200 and a lower casing 300 covering the receiver 100.

(8) The receiver 100, having a general form, includes a frame, a magnetic circuit including a yoke and a permanent magnet, a voice coil vibrated by mutual electromagnetic force with the magnetic circuit, and a diaphragm 110 provided with the voice coil and generating a sound by vibration. Here, for smooth vibration of the diaphragm 110, the receiver 100 includes a back hole 120 allowing air outside the receiver 100 to flow to the lower space of the diaphragm 110. The back hole 120 may be formed at a yoke or the frame according to a shape of the magnetic circuit structure or the frame of the receiver 100.

(9) The upper casing 200 protects the receiver 100 and facilitates installation when installed in a housing 600 of an earphone. The upper casing 200 covers an upper portion of the receiver 100 and surrounds a side surface. The upper casing 200 is attached to the housing 600 by an adhesive 500 such as a double-sided tape. In an embodiment of the present invention, the receiver 100 is circular, so the upper casing 200 has a cylindrical shape. The housing 600 includes a sound tube 620 guiding sound into a user's ear and protruding to be inserted into the ear in case of a closed earphone. The upper casing 200 includes a sound insulation hole 210 corresponding to a position of the sound tube 620 so that a sound of the receiver 100 may be emitted to the sound tube 620.

(10) Here, the upper casing 200 has ventilation recesses 220 and 230 provided on an outer surface thereof to allow a lower space of the receiver unit and the sound tube 620 to communicate with each other to improve user inconvenience such as occurrence of deafening of the ear or the like due to a difference in pressure between an ear canal and inside/outside of the earphone as the earphone completely seals the ear canal.

(11) The ventilation recesses 220 and 230 include a first ventilation recess 220 extending from the sound insulation hole 210 to the side of the upper casing 200, i.e., to an outer circumference, in the radial direction and formed in a horizontal direction and a second ventilation recess 230 communicating with the first ventilation recess 220 and extending in a vertical direction to have an overall length of the side surface of the upper casing 200.

(12) As air may flow from the sound tube 620 to the lower space of the receiver unit through the first ventilation recess 220 and the second ventilation recess 230, a change in pressure that may occur in the ear canal due to vibration of the diaphragm 110 of the receiver 100 may be buffered.

(13) However, buffering the change in pressure formed at the diaphragm 110 by air flowing from the sound tube 620 to the lower space of the receiver unit inevitably decreases a sound pressure, and in particular, increases loss of sound pressure in a low frequency range.

(14) In order to prevent this, a duct path 310 capable of improving low-frequency sound by generating resonance in the lower casing 300 is provided. Since the lower casing 300 is attached to the lower surface of the receiver 100 and an upper surface is closed by the receiver 100, the duct path 310 may be formed by forming a recess on the upper surface of the lower casing 300. An upper end of the duct path 310 communicates with the back hole 120 of the receiver 100 described above, and a lower end of the duct path 310 communicates with the lower space of the receiver unit in the earphone housing.

(15) Meanwhile, in order to compensate for low frequency sound, the receiver unit may have an acoustic mesh. One or more acoustic meshes 510 and 520 may be provided in the duct path 310.

(16) A first acoustic mesh 510 is attached to the receiver 100 to facilitate attachment and formed to cover the back hole 120. The duct path 310 includes a receiving recess 320 with an end having a diameter larger than that of the first acoustic mesh 510 to accommodate the first acoustic mesh 510.

(17) The second acoustic mesh 520 is attached to the lower surface of the lower casing 300. The second acoustic mesh 520 is attached to cover the end of the duct path 310.

(18) FIG. 4 is a graph showing comparison of sound pressure by frequency of a general canal-type earphone, a canal-type earphone having a receiver with a ventilation recess, and a canal-type earphone including a ventilation recess and a duct.

(19) As can be seen from the graph, the canal-type earphone has a high SPL in the low frequency region, but if a ventilation recess is provided in order to relieve deafening of the ear, large loss occurs in the SPL in the low frequency region. In contrast, when the ventilation recess and the duct are provided together as in the present invention, the SPL loss occurring in the low frequency region may be compensated to some extent.

(20) Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.