Wireless earphone

A wireless earphone including a top cover, a bottom cover, two rigid circuit boards, a flexible circuit board, and an antenna is provided. The bottom cover is connected to the top cover, and an inner chamber is formed between the top cover and the bottom cover. The two rigid circuit boards are disposed at intervals in the inner chamber. The flexible circuit board has a first connection part and a second connection part. Two ends of the first connection part are coupled to the two rigid circuit boards respectively. The second connection part is attached on at least one of the two rigid circuit boards. The antenna is coupled to a corresponding rigid circuit board to radiate a radio frequency signal. A coupling capacitor is formed at a parallel overlapping area between the second connection part and the rigid circuit board.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 108140964, filed on Nov. 12, 2019. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The disclosure relates to a wireless earphone, in particular, to a wireless earphone capable of improving antenna operation bandwidth and radiation efficiency.

Description of Related Art

The existing wireless earphone has a main research and development direction of light weight and convenience. However, pattern routing of an antenna may be limited by a limited space inside the wireless earphone. Operation bandwidth and radiation efficiency of the antenna are relevant to an antenna dimension and an antenna ground plane. Too small antenna dimension and antenna ground plane may cause radiation performance worsening. Nowadays, through bending shaping of a flexible circuit board, an antenna ground plane dimension conforming to standards can be reached. However, inductive electronic wire distribution in the flexible circuit board is unfavorable for antenna radiation, so that severe attenuation during signal transmission is caused. An unstable connection condition between the wireless earphone and an electronic device may be caused by the attenuation of radio frequency signals, so that quality of the wireless earphone is influenced.

SUMMARY

The disclosure provides a wireless earphone. A coupling capacitor may be generated by combining a flexible circuit board and rigid circuit boards, and is configured to improve antenna operation bandwidth of the wireless earphone and radiation efficiency of an antenna.

The wireless earphone of the disclosure includes a top cover, a bottom cover, two rigid circuit boards, a flexible circuit board and an antenna. The bottom cover is connected to the top cover, and an inner chamber is formed between the top cover and the bottom cover. The two rigid circuit boards are disposed at intervals in the inner chamber. The flexible circuit board has a first connection part and a second connection part. Two ends of the first connection part are coupled to the two rigid circuit boards respectively. The second connection part is attached on at least one of the two rigid circuit boards. The antenna is coupled to the corresponding rigid circuit board to radiate a radio frequency signal. A coupling capacitor is formed at a parallel overlapping area between the second connection part and the rigid circuit board.

Based on the above, the flexible circuit board of the wireless earphone of the disclosure is disposed between the upper and lower rigid circuit boards. The flexible circuit board extends and is in contact with at least one of the rigid circuit boards and is insulated from the rigid circuit board. The coupling capacitor is formed at a mutual contact parallel overlapping area between the flexible circuit board and the rigid circuit board, and is configured to compensate an inductive effect of an electronic pattern of the flexible circuit board. An effect of improving the operation bandwidth and radiation efficiency of the antenna is achieved, and further, the wireless earphone of the disclosure reaches high-reliability wireless transmission quality.

Complementally, an added capacitance effect can effectively improve the radiation efficiency of the antenna of the wireless earphone. Therefore, an unstable connection condition between the wireless earphone and an external electronic device can be avoided.

To make the features and advantages of the disclosure clear and easy to understand, the following gives a detailed description of embodiments with reference to accompanying drawings.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1Ais a schematic perspective view of a wireless earphone of an embodiment of the disclosure.FIG. 1Bis a schematic exploded view of elements of the wireless earphone inFIG. 1A.

Referring toFIG. 1AandFIG. 1B, a wireless earphone100of the disclosure is applicable to mutual wireless connection with an external electronic device (such as a smartphone, a tablet computer or other similar devices) through a wireless transmission technology (such as WIFI, Bluetooth or other similar technologies). The electronic device transmits a control instruction and audio data to the wireless earphone100through wireless transmission, so as to achieve goals of wireless control and audio output.

The wireless earphone100of the disclosure includes a top cover110, a bottom cover120, two rigid circuit boards130, a flexible circuit board140and an antenna150.

The bottom cover120is connected to the top cover110. In the present embodiment, the bottom cover120and the top cover110, for example, are mutually clamped and buckled, and an inner chamber IS is formed between the top cover110and the bottom cover120. The two rigid circuit boards130are disposed at intervals in the inner chamber IS, and approach to the top cover110and the bottom cover120respectively. Complementally, the two rigid circuit boards130are configured to dispose metal circuits and other required electronic elements.

The flexible circuit board140has a first connection part141and a second connection part142. Two ends of the first connection part141are coupled to the two rigid circuit boards130respectively. The second connection part142is attached on at least one of the two rigid circuit boards130. Referring toFIG. 1B, the second connection part142of the flexible circuit board140of the present embodiment is attached on one of the rigid circuit boards130positioned in the bottom cover120.

An antenna150is coupled to a corresponding rigid circuit board130to radiate a radio frequency signal. In the present embodiment, the antenna150is disposed on the top cover110. In other embodiments, the antenna150may also be disposed on the bottom cover120, and this depends on requirements. Further, the antenna, for example, includes a monopole antenna, an inverted-F antenna, a loop antenna or other kinds of antennas, wherein the antenna may be made through laser forming or in a flexible printed circuit board form.

The second connection part142and the contact rigid circuit board130are not mutually conducted, so that a coupling capacitor is formed at a parallel overlapping area OA between the second connection part142and the rigid circuit board130.

FIG. 2Ais a schematic view of connection of rigid circuit boards, a flexible circuit board and an antenna of the wireless earphone inFIG. 1B.FIG. 2Bis a top view of one of the rigid circuit boards130and the flexible circuit board positioned in the bottom cover120inFIG. 1B.FIG. 2Cis a detailed schematic structural view of the flexible circuit board and the rigid circuit boards of the wireless earphone inFIG. 1B.

Referring toFIG. 1B,FIG. 2AandFIG. 2B, the first connection part141of the flexible circuit board140includes two channel branch sections CP. The two channel branch sections CP are coupled to the two rigid circuit boards130respectively. Detailedly, each channel branch section CP is applicable to extend from a lateral edge of each rigid circuit board130, so that the two rigid circuit boards130can be mutually and electrically conducted, wherein a connection condition of each channel branch section CP and each rigid circuit board130may be freely regulated according to the design requirements of the wireless earphone100.

The second connection part142of the flexible circuit board140includes a central branch section P1and a lower branch section P2. The central branch section P1is partially connected with the first connection part141and extends towards the bottom cover120. The lower branch section P2vertically extends from the central branch section P1and is parallel to the corresponding rigid circuit board130. The lower branch section P2is partially overlapped on an upper surface TS of the rigid circuit board130. In other embodiments, the lower branch section P2may also be partially overlapped on a lower surface BS of the rigid circuit board130. The disclosure is not limited thereto.

Referring toFIG. 2C, the lower branch section P2has a first metal layer FL and an insulation film layer IL. The first metal layer FL faces one of the rigid circuit boards130. The insulation film layer IL is disposed outside the first metal layer FL so as to cover the first metal layer FL. One of the rigid circuit boards130has a second metal layer SL, and the insulation film layer IL is positioned between the first metal layer FL and the second metal layer SL so as to form a coupling capacitor.

In other embodiments, an insulation film layer is, for example, disposed on a second metal layer of the rigid circuit board so as to cover the second metal layer, and is positioned between the first metal layer and the second metal layer so as to form a coupling capacitor. The insulation film layers are, for example, disposed on a first metal layer of the lower branch section and a second metal layer of the rigid circuit board respectively so as to cover the first metal layer and the second metal layer, and are positioned between the first metal layer and the second metal layer so as to form a coupling capacitor.

Detailedly, the insulation film layer IL is disposed between the first metal layer FL of the lower branch section P2and the second metal layer SL of one of the rigid circuit boards130, so that the lower branch section P2and the rigid circuit board130are electrically insulated. The first metal layer FL and the second metal layer SL are in contact with upper and lower sides of the insulation film layer IL respectively to form a ground plane G, so that a coupling capacitor is formed in an overlapping area OA of the first metal layer FL, the insulation film layer IL and the second metal layer SL, and is configured to compensate an inductive effect of the flexible circuit board140.

Referring toFIG. 2AandFIG. 2B, in the present embodiment, an area of the overlapping area OA between the lower branch section P2and the rigid circuit board130is 2 mm*4.5 mm, and the area is a proper size for forming the effective coupling capacitor. An included angle A between the first connection part141and the second connection part142of the flexible circuit board140is greater than 90 degrees, and is preferably 135 degrees. In other embodiments, the overlapping area OA and the included angle A can be correspondingly regulated according to the design requirements or a dimension of the wireless earphone, and the disclosure is not limited thereto.

Referring toFIG. 1A,FIG. 1BandFIG. 2A, further, the wireless earphone100also includes a loudspeaker unit160, a power supply unit170and a connection piece180.

The loudspeaker unit160is disposed in the bottom cover120, is coupled to one of the rigid circuit boards130, and is configured to convert digital audio into analog sound and transmit the analog sound into human ears. The power supply unit170is, for example, a rechargeable battery disposed between the two rigid circuit boards130, is mutually and electrically coupled with the two rigid circuit boards, and is configured to provide electric power required for operation of the wireless earphone100. The connection piece180is disposed on the corresponding rigid circuit board130.

The antenna150is coupled to the rigid circuit board130through the connection piece180and bends and extends along an inner side surface of the top cover110, and the antenna150is suitable for being attached on the inner side surface of the top cover110so as to save space. In other embodiments, the antenna bends and extends along an outer side surface of the top cover110and is suitable for being attached on the outer side surface of the top cover so that the antenna cannot be blocked by the top cover.

Further, the wireless earphone100also includes a support piece disposed between the two rigid circuit boards130. The flexible circuit board140is attached on an outer surface of the support piece, and the support piece is electrically insulated.

FIG. 3Ais a schematic perspective view of a flexible circuit board of the wireless earphone of the disclosure using another embodiment.FIG. 3Bis a detailed schematic structural view of the flexible circuit board and rigid circuit boards inFIG. 3A.

Referring toFIG. 2AandFIG. 3A, the wireless earphone of the present embodiment uses a flexible circuit board140aof another embodiment. The difference is that a second connection part142aof the flexible circuit board140aincludes a central branch section P1and an upper branch section P3. The central branch section P1is partially connected with the first connection part141aand extends towards the top cover110. The upper branch section P3vertically extends from the central branch section P1and is parallel to the corresponding rigid circuit board130a. The upper branch section P3is partially overlapped on an upper surface TS or a lower surface BS of the rigid circuit board130a.

Referring toFIG. 3AandFIG. 3B, the upper branch section P3has an insulation film layer IL and a first metal layer FL. The insulation film layer IL is disposed outside the first metal layer FL. The rigid circuit board130ahas a second metal layer SL. The insulation film layer IL is positioned between the first metal layer FL and the second metal layer SL so as to form the coupling capacitor.

Detailedly, the insulation film layer IL is disposed between the first metal layer FL of the upper branch section P3and the second metal layer SL of the rigid circuit board130a, so that the upper branch section P3and the rigid circuit board130aare electrically insulated. The first metal layer FL and the second metal layer SL are in contact with the upper and the lower sides of the insulation film layer IL respectively to form a ground plane G, so that a coupling capacitor is formed in the overlapping area OA of the first metal layer FL, the insulation film layer IL and the second metal layer SL, and is configured to compensate an inductive effect of the flexible circuit board140a.

In other embodiments, an insulation film layer is, for example, disposed on a second metal layer of the rigid circuit board so as to cover the second metal layer. The insulation film layer is positioned between the first metal layer and the second metal layer so as to form a coupling capacitor. The insulation film layers are, for example, disposed on the first metal layer of the upper branch section and the second metal layer of the rigid circuit board so as to cover the first metal layer and the second metal layer, and are positioned between the first metal layer and the second metal layer so as to form a coupling capacitor.

FIG. 4Ais a schematic perspective view of a flexible circuit board of the wireless earphone of the disclosure using yet another embodiment.FIG. 4BandFIG. 4Care detailed schematic structural views of the flexible circuit board and two rigid circuit boards inFIG. 4Arespectively.

Referring toFIG. 2AandFIG. 4A, the wireless earphone of the present embodiment uses a flexible circuit board140bof the yet another embodiment. A second connection part142bof the flexible circuit board140bincludes a central branch section P1, a lower branch section P2and an upper branch section P3.

The central branch section P1is partially connected with the first connection part141band extends towards the top cover110and the bottom cover120respectively. The upper branch section P3and the lower branch section P2vertically extend from two ends of the central branch section P1respectively and are parallel to the two rigid circuit boards130brespectively. The upper branch section P3is partially overlapped on an upper surface TS or a lower surface BS of one of the rigid circuit boards130b. The lower branch section P2is partially overlapped on an upper surface TS or a lower surface BS of the other one of the rigid circuit boards130b.

Referring toFIG. 4AtoFIG. 4C, the upper branch section P3has a first insulation film layer IL1and a first metal layer FL. The first insulation film layer IL1is disposed outside the first metal layer FL. One of the rigid circuit boards130bhas a second metal layer SL. The first insulation film layer IL1is positioned between the first metal layer FL and the second metal layer SL so as to form a coupling capacitor (as shown inFIG. 4B).

Detailedly, the first insulation film layer IL1is disposed between the first metal layer FL of the upper branch section P3and the second metal layer SL of the rigid circuit board130b, so that the upper branch section P3and the rigid circuit board130bare electrically insulated. The first metal layer FL and the second metal layer SL are in contact with upper and lower sides of the first insulation film layer IL1respectively to form a ground plane G, so that a coupling capacitor is formed at an overlapping area OA of the first metal layer FL, the first insulation film layer IL1and the second metal layer SL.

In other embodiments, a first insulation film layer is, for example, disposed on a second metal layer of one of the rigid circuit boards so as to cover the second metal layer. The first insulation film layer is positioned between the first metal layer and the second metal layer so as to form a coupling capacitor. The first insulation film layers are, for example, disposed on the first metal layer of the upper branch section and the second metal layer of one of the rigid circuit boards so as to cover the first metal layer and the second metal layer, and are positioned between the first metal layer and the second metal layer so as to form a coupling capacitor.

The lower branch section P2has a second insulation film layer IL2and a third metal layer TL. The second insulation film layer IL2is disposed outside the third metal layer TL. The other one of the rigid circuit boards130bhas a fourth metal layer HL. The second insulation film layer IL2is positioned between the third metal layer TL and the fourth metal layer HL so as to form another coupling capacitor (as shown inFIG. 4C).

Detailedly, the second insulation film layer IL2is disposed between the third metal layer TL of the lower branch section P2and a fourth metal layer HL of one of the rigid circuit boards130b, so that the lower branch section P2and the rigid circuit board130bare electrically insulated. The third metal layer TL and the fourth metal layer HL are in contact with upper and lower side surfaces of the second insulation film layer IL2respectively to form a ground plane G, so that a coupling capacitor is formed at an overlapping area OA of the third metal layer TL, the second insulation film layer IL2and the fourth metal layer HL.

In other embodiments, a second insulation film layer is, for example, disposed on the other one of the rigid circuit boards so as to cover a fourth metal layer, and the second insulation film layer is positioned between the third metal layer and the fourth metal layer so as to form a coupling capacitor. The second insulation film layers are, for example, disposed on the third metal layer of the lower branch section and the fourth metal layer of the other one of the rigid circuit boards respectively so as to cover the third metal layer and the fourth metal layer, and are positioned between the third metal layer and the fourth metal layer so as to form a coupling capacitor.

Briefly, compared with the embodiments inFIG. 2AandFIG. 3A, the embodiment inFIG. 4Aforms the coupling capacitors on the two rigid circuit boards respectively.

FIG. 5is an antenna efficiency diagram of the wireless earphone of the disclosure. Referring toFIG. 5, a line section L2is a frequency response of antenna efficiency of the wireless earphone100of the disclosure. A line section L1is a frequency response of antenna efficiency of an existing wireless earphone. The antenna efficiency of the line section L2is closer to 0 dB than that of the line section L1, which shows that a signal attenuation degree of the line section L2is lower, and wireless transmission quality is higher.

In conclusion, a flexible circuit board of the wireless earphone of the disclosure is disposed between upper and lower rigid circuit boards. The flexible circuit board extends and is in contact with at least one of the rigid circuit boards and is insulated from the rigid circuit board. A coupling capacitor is formed at a mutual contact parallel overlapping area between the flexible circuit board and the rigid circuit board, and is configured to compensate an inductive effect of an electronic pattern of the flexible circuit board. An effect of operation bandwidth and radiation efficiency of a radio antenna is improved, and further the wireless earphone of the disclosure reaches high-reliability wireless transmission quality.

Complementally, an added capacitance effect can effectively improve the radiation efficiency of the antenna of the wireless earphone. Therefore, an unstable connection condition between the wireless earphone and an external electronic device can be avoided.

Although the disclosure is described with reference to the above embodiments, the embodiments are not intended to limit the disclosure. A person of ordinary skill in the art may make variations and modifications without departing from the spirit and scope of the disclosure. Therefore, the protection scope of the disclosure should be subject to the appended claims.