Patent ID: 12251001

DETAILED DESCRIPTION

Technical solutions of the embodiments of the present disclosure will be clearly and completely described in the following by as shown in the accompanying drawings. Obviously, the embodiments described are only a part of the embodiments of the present disclosure, but not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.

Reference herein to an “embodiment” means that a particular feature, structure, or characteristic described in combination with the embodiment may be included in at least one embodiment of the present disclosure. A presence of the term in various places in the specification is not necessarily all as shown in the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

It should be pointed out that the terms “first”, “second” and the like herein are only used for a description purpose, and cannot be construed as indicating or implying relative importance or implying the number of indicated technical features. Therefore, features defined by “first”, “second” may expressly or implicitly include one or more of the features.

According to a first aspect of the present disclosure, a strap adjusting device is provided and configured for adjusting a length of a strap of a wearable device. The strap adjusting device includes a pressing piece, a first sensor, and a tightness adjusting mechanism. The pressing piece includes a supporting plate connected to the strap and a cushion arranged on the supporting plate. The first sensor is arranged on the pressing piece and configured to detect a deformation parameter value of the cushion. The tightness adjusting mechanism cooperates with the strap and configured to adjust the length of the strap in response to the deformation parameter value of the cushion.

In some embodiments, the tightness adjusting mechanism is configured to stop adjusting the length of the strap, in response to the first sensor detecting the deformation parameter value of the cushion reaching a preset threshold.

In some embodiments, the deformation parameter value of the cushion includes a thickness of the cushion.

In some embodiments, the first sensor includes a first sensing device arranged on one of the supporting plate and the cushion; and a first magnet arranged on the other of the supporting plate and the cushion. The first sensing device is configured to detect the thickness of the cushion by detecting a magnetic field generated by the first magnet.

In some embodiments, the first magnet is arranged on a surface of the cushion away from the supporting plate, and the first sensing device is arranged on a surface of the supporting plate close to the cushion.

In some embodiments, the strap has a first state in which the strap has the longest length and a second state in which the strap has the shortest length, the strap adjusting device further includes a second sensor connected to the tightness adjusting mechanism and configured to detect a length of the strap. The tightness adjusting mechanism is configured to stop adjusting the length of the strap in response to the length of the strap being in the first state or the second state.

In some embodiments, the tightness adjusting mechanism includes a housing. The housing is sleeved outside the strap, strap one end of the strap extends out the housing from one end of the housing, and the other end of the strap extends out the housing from the other end of the housing; The second sensor includes a second magnet, a second sensing device, and a third sensing device. The second magnet is fixed on the strap. The second sensing device is arranged on the housing and corresponds to the second magnet in response to the strap being in the first state. The third sensing device is arranged on the housing and corresponds to the second magnet in response to the strap being in the second state.

In some embodiments, in response to the strap being in the first state or the second state, the second magnet is located in the housing, and both the second sensing device and the third sensing device are arranged on an inner wall of the housing.

In some embodiments, the strap further includes a controlling switch connected to the tightness adjusting mechanism. The tightness adjusting mechanism is configured to perform an elongation adjusting process to increase the length of the strap in response to the controlling switch being in a first controlling state. The tightness adjusting mechanism is configured to perform a contraction adjusting process to decrease the length of the strap in response to the controlling switch being in a second controlling state.

According to a second aspect of the present disclosure, a wearable device is provided and includes a host housing, a tightness adjusting mechanism, a strap assembly, a force-bearing component, and a first sensor. The tightness adjusting mechanism is opposite to the host housing. The strap assembly is connected to the host housing and the tightness adjusting mechanism to obtain an annular frame and includes a first head strap connected to an end of the host housing and an end of the tightness adjusting mechanism and a second head strap connected an opposite end of the host housing and an opposite end of the tightness adjusting mechanism. The tightness adjusting mechanism is cooperatively connected to the first head strap and the second head strap to adjust an overlapping length between the first head strap and the second head strap. The force-bearing component includes a fixing plate arranged on the annular frame and a cushion arranged on the fixing plate. The first sensor is arranged on the force-bearing component and configured to detect the deformation parameter value of the cushion. The tightness adjusting mechanism is configured to adjust the overlapping length between the first head strap and the second head strap, in response to the deformation parameter value of the cushion.

In some embodiments, the tightness adjusting mechanism is configured to stop adjusting the overlapping length between the first head strap and the second head strap, in response to the first sensor detecting the deformation parameter value of the cushion reaching a preset threshold.

In some embodiments, a first end of the first head strap and a second end of the second head strap overlaps each other, a first length-adjusting hole is defined at the first end, a second length-adjusting hole is defined at the second end, a first sawtooth wave is arranged in the first length-adjusting hole, and a second sawtooth wave is arranged in the second length-adjusting hole. The tightness adjusting mechanism includes a housing for the tightness adjusting mechanism, a ratchet-pawl mechanism and a driving assembly. The housing for the tightness adjusting mechanism includes a continuous channel, and the first end and the second end are received in the continuous channel. The ratchet-pawl mechanism is accommodated in the housing for the tightness adjusting mechanism and includes a ratchet, a pawl assembly and a transmission gear. The pawl assembly engages with the ratchet and includes an engaging gear. The engaging gear is arranged in both the first length-adjusting hole and the second length-adjusting hole and is engaged with both the first sawtooth wave and the second sawtooth wave, the first sawtooth wave is located on one side of the engaging gear, and the second sawtooth wave is located on a side of the engaging gear opposite to the first sawtooth wave. The transmission gear is accommodated in the housing for the tightness adjusting mechanism and cooperates with the pawl assembly to drive the pawl assembly to rotate. The driving assembly is accommodated in the housing for the tightness adjusting mechanism and engaged with the transmission gear. In response to the deformation parameter value of the cushion, the driving assembly is configured to drive the pawl assembly to rotate by driving the transmission gear to rotate, and the engaging gear is driven to rotate, such that the first head strap and the second head strap are driven to move relative to each other.

In some embodiments, the pawl assembly further includes a mounting element, a rotating plate and a pawl. The engaging gear is arranged on one side of the mounting element. The rotating plate is arranged on the other side of the mounting element, being rotatable, and cooperates with the transmission gear. The pawl is pivotally connected to the mounting element, one end of the pawl abuts against a side surface of the rotating plate, and the other end of the pawl is engaged with the ratchet.

In some embodiments, the fixing plate is fixed on the housing for the tightness adjusting mechanism.

In some embodiments, the strap assembly has a first state in which the overlapping length between the first head strap and the second head strap is the shortest and a second state in which the overlapping length between the first head strap and the second head strap is the longest. The wearable device further includes a second sensor connected to the tightness adjusting mechanism and configured to detect a length of the strap assembly. The tightness adjusting mechanism is configured to stop adjusting the overlapping length between the first head strap and the second head strap in response to the length of the strap assembly being in the first state or the second state.

In some embodiments, the wearable device further includes a controlling switch connected to the tightness adjusting mechanism. The tightness adjusting mechanism is configured to perform an adjusting process to decrease the overlapping length between the first head strap and the second head strap in response to the controlling switch being in a first controlling state. The tightness adjusting mechanism is configured to perform an adjusting process to increase the overlapping length between the first head strap and the second head strap, in response to the controlling switch being in a second controlling state.

According to a third aspect of the present disclosure, a strap adjusting device is provided and configured for adjusting a length of a strap of a wearable device. The strap adjusting device includes a housing, a cushion, a first sensor a tightness adjusting mechanism, and a processor. The housing is connected to the strap. The cushion is arranged on the housing. The first sensor is arranged on at least one of the housing or the cushion and configured to detect a deformation parameter value of the cushion. The tightness adjusting mechanism is cooperatively connected to the strap and configured to adjust the length of the strap. The processor is configured to control the tightness adjusting mechanism to adjust the length of the strap, in response to the deformation parameter value of the cushion detected by the first sensor.

In some embodiments, the processor is configured to control the tightness adjusting mechanism to stop adjusting the length of the strap, in response to the deformation parameter value of the cushion reaching a preset threshold.

In some embodiments, the strap has a first state in which the strap has the longest length and a second state in which the strap has the shortest length. The strap adjusting device further includes a second sensor connected to the processor and configured to detect whether a length of the strap is in the first state or the second state. The processor is configured to control the tightness adjusting mechanism to stop adjusting the length of the strap in response to the length of the strap being in the first state or the second state.

In some embodiments, the strap adjusting device further includes a controlling switch connected to the processor. The processor is configured to control the tightness adjusting mechanism to perform an elongation adjusting process for the strap in response to the controlling switch being in a first controlling state. The processor is configured to control the tightness adjusting mechanism to perform a contraction adjusting process to decrease the length of the strap in response to the controlling switch being in a second controlling state.

A wearable device is provided in the present disclosure. In some embodiments, the wearable device may be a head-mounted device (such as smart glasses, etc.), a smart watch, a smart belt, and the like. As shown inFIG.1, a head-mounted device100may be used for illustration in some embodiments of the present disclosure. The head-mounted device100may include a first housing assembly10, a strap assembly20connected to two ends of the first housing assembly10, a tightness adjusting mechanism40connected to the strap assembly20, a second housing assembly30arranged on the strap assembly20and opposite to the first housing assembly10, a force-bearing assembly50arranged on the first housing assembly10and the second housing assembly30, a first sensor (as shown inFIG.34) arranged on the force-bearing assembly50, a second sensor (as shown inFIG.17andFIG.27) arranged on at least one of the tightness adjusting mechanism40and the strap assembly20, and a controlling switch (as shown inFIG.37). In some embodiments, the first housing assembly10, the strap assembly20, the second housing assembly30, and the tightness adjusting mechanism40may be assembled to obtain a tightness-adjustable frame, such that the head-mounted device100may be easily worn on the head of the user. The force-bearing assembly50is arranged on an upper side and a lower side of the frame and configured to share a weight of the head-mounted device100applied to the head of the user. Both the first sensor and the second sensor are configured to detect a stretching state of the strap assembly20.

As further shown inFIG.2andFIG.3, the head-mounted device100of some embodiments of the present disclosure may further include a host accommodated in the first housing assembly10. The host may include an optical-mechanical assembly60, a camera assembly70, a motherboard80, a speaker assembly91, a microphone assembly92, etc. Since the first housing assembly10is configured to accommodate and protect the host, the first housing assembly10may also be referred to as a host housing or a protection housing. The first housing assembly10and the host accommodated in the first housing assembly10may be assembled to obtain a host assembly. The head-mounted device100may be VR glasses, AR glasses, or the like. In some embodiments of the present disclosure, the AR glasses are taken as an example for description.

In the example of AR glasses, the head-mounted device100may be configured to transmit data to and receive data from an external processing device through a signal connection. The signal connection may be wired connection, wireless connection, or a combination of the wired connection and the wireless connection. However, in other cases, the head-mounted device100may be configured as an independent device. That is, data is processed by head-mounted device100itself. The signal connection may be configured to carry any kind of data, such as image data (e.g., a still image and/or a fully motion video, including a 2D and a 3D image), audios, multimedia, voices and/or any other type of data. The external processing device may be, for example, a game console, a personal computer, a tablet computer, a smartphone, or other type of processing devices. The signal connection may be, for example, Universal Serial Bus (USB) connection, Wi-Fi connection, Bluetooth or Bluetooth Low Energy (BLE) connection, Ethernet connection, cable connection, DSL connection, cellular connection (e.g., 3G, LTE/4G or 5G) or a combination thereof. In addition, the external processing device may be configured to communicate with one or more other external processing devices via a network. The network may be or include, for example, a local area network (LAN), a wide area network (WAN), an intranet, a metropolitan area network (MAN), a global Internet, or a combination thereof.

The first housing assembly10of the head-mounted device100may be installed with a display assembly, an optical element, a sensor, a processor, and the like. In the example of AR glasses, the display component may be designed to, for example, overlap an image on a user's view of a real-world environment, by projecting light into eyes of the user. The head-mounted device100may also include an ambient light sensor, and an electronic circuit system to control at least some of above-described components and perform associated data processing functions. The electronic circuit system may include, for example, one or more processors and one or more memories.

As shown inFIG.4andFIG.5,FIG.4shows a perspective assembly view of a first housing assembly10of the head-mounted device100, andFIG.5shows an exploded perspective view of the first housing assembly10in the embodiments of the present disclosure. The first housing assembly10may include a main front housing11, a main rear housing12engaging with the main front housing11through a snap-fit connection, a mask13arranged in front of the main front housing11, a rear cover14located below the main rear housing12and engaged with a lower portion of the mask13, and a housing decoration component15arranged on a top of the main front housing11.

Herein, the description will be made with reference to orientations “upper”, “lower”, “front”, “rear”, “left”, and “right” indicated inFIGS.1and4. It should be understood that orientations or position relationships indicated by terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc. are based on orientations or position relationships shown in the accompanying drawings, which are only for a convenience to describe the present disclosure and simplifying the description, rather than indicating or implying that the indicated devices or elements must have a specific orientation, or a construction and an operation must be in a particular orientation. Therefore, these above terms should not be construed as limitations to the present disclosure.

As shown inFIG.6,FIG.6shows is a perspective assembly view of a strap assembly20and a second housing assembly30in the embodiments of the present disclosure. The strap assembly20may include two head straps, a first head strap21and a second head strap22, respectively.

As shown inFIG.1, one end of the first head strap21is connected to one corresponding end of the first housing assembly10, and the other end of the first head strap21extends into a corresponding end of the second housing assembly30and is further connected to the tightness adjusting mechanism40. The second head strap22may be configured in a similar manner as the first head strap21.

As shown inFIG.7andFIG.8,FIG.7shows a perspective assembly view of the first head strap21, andFIG.8shows a perspective exploded view of the first head strap21. The first head strap21may include a first strap body210, a first strap cover211buckled to or engaged with the first strap body210, a first flexible strip212, a power supply FPC213, a protection sheet214, and a heat dissipation sheet215. The first strap body210, the first strap cover211, the first flexible strip212, the power supply FPC213, the protection sheet214, and the heat dissipation sheet215are disposed between and pressed by the first strap body210and the first strap cover211.

The first strap body210may be made of a flexible material, may be bent arbitrarily, and may be substantially in a strip shape. The first strap body210may include a first body portion2101and a first mounting portion2102extending from an end of the first body portion2101.

The first body portion2101has a uniform width. A first length-adjusting hole2103is defined at an end of the first body portion2101away from the first mounting portion2102. The first length-adjusting hole2103is a strip-shaped through hole. A first sawtooth wave2104is arranged on a wall of the first length-adjusting hole2103defined in the first body portion2101, and extends along a length direction of the strip-shaped through hole to be engaged with the tightness adjusting mechanism40.

As shown inFIG.9,FIG.9shows a perspective exploded view of the first head strap21of the present disclosure from another view. A side of the first body portion2101that is pressed against the first strap cover211may define an elongated groove, and a shape of the elongated groove may be the same as a shape of the first head strap21. The elongated groove may be divided into two grooves, that is, a first sub groove2105and a second sub groove2106fluidly connected to the first sub groove2105. A depth of the first sub groove2105is the same with a depth of the second sub groove2106, while a width of the first sub groove2105is greater than a width of the second sub groove2106. The groove extends to a position in which the first mounting portion2102is located from a position adjacent to the first length-adjusting hole2103. The second sub groove2106is in a stepped shape. An outermost step of the second sub groove2106may be configured to accommodate the first flexible strip212. Each of two side edges of the first body portion2101adjacent to two side walls of the first sub groove2105is arranged with a first connector2107. In an embodiment, the first connector2107may be multiple hooks that are evenly distributed and spaced apart from each other. A first fixing portion2108may be arranged on a wall of the first sub groove2105. The first fixing portion2108may be multiple protruding ribs with a gradually changing thickness. A top surface of each of the protruding ribs may be inclined. An end of each of the protruding ribs abuts against the first mounting portion2102.

Multiple first restriction posts2109are arranged on a wall of the groove of the first body portion2101and configured to fix the power supply FPC213, the protection sheet214, and the heat dissipation sheet215.

Two first connection holes2100are defined in the first mounting portion2102. A recess2102ais defined between the two first connection holes2100.

As shown inFIG.8, the first strap cover211may be made of a rigid material. The first strap cover211may be configured to be buckled with the first strap body210at a side of the first strap body210close to or near the first mounting portion2102, and to press an end of the first flexible strip212close to the first mounting portion2102tightly.

The first strap cover211may include a first body2111and a first assembly portion2112extending from an end of the first body2111away from the first flexible strip212.

The first body2111has a uniform width. A shape of the first strap cover211corresponds to a shape of the first body portion2101, but a length of the first body2111is less than a length of the first body portion2101. One first side wall2116extends from one side edge in a width direction of the first body2111along a direction facing towards the first body portion2101, and the other first side wall2116extends from the other side edge in a width direction of the first body2111, along the direction facing towards the first body portion2101. The two first side walls2116have two inner side faces facing towards each other, and each of the two inner side faces is arranged with a second connector2117. The second connector2117may be engaged with the first connector2107to fix the first strap cover211to the first strap body210. A second fixing portion2114may be arranged on an end of the first strap cover211connected to the first assembly portion2112. When the first strap cover211is buckled to the first strap body210, the second fixing portion2114of the first strap cover211may be engaged with the first fixing portion2108of the first strap body210to press tightly and fix the power supply FPC213and the heat dissipation sheet215between the first strap body210and the first strap cover211. A structure of the second fixing portion2114may be similar to a structure of the first fixing portion2108. The second fixing portion2114may also be multiple protruding ribs with gradually changing thicknesses. A top surface of each of the protruding ribs2114is inclined and an end of each of the protruding ribs2114abuts against the first assembly portion2112.

A shape of the first assembly portion2112is the same with a shape of the first mounting portion2102. Second connection holes2110are defined on the first assembly portion2112. When the first assembly portion2112is attached to first mounting portion2102, the first connection holes2100are aligned with and fluidly coupled to the second connection holes2110, and a through hole is defined at a position at which the recess2102ais defined.

The first flexible strip212is made of a flexible material, may be bent arbitrarily, and may substantially be in a strip shape. A material of the first flexible strip212may be the same as that of the first strap body210. The first flexible strip212may be adhered to the second sub groove2106of the first strap body210by means of gluing and the like. In this way, an outer surface of the first flexible strip212may be substantially flush with an outer surface of the first strap body210, that is, flush with a surface close to the head of the user. A notch2120is defined at an end of the first flexible strip212. When the first flexible strip212is adhered to the second sub groove2106, the first flexible strip212and the first strap body210cooperatively define a first through hole at a position at which the notch2120is defined. The first through hole is fluidly coupled to the second sub groove2106to allow the power supply FPC213to pass through.

As shown inFIGS.7,8and9, a shape of the power supply FPC213is adapted to the first strap body210, but a length of the power supply FPC213is greater than the first strap body210. One end of the power supply FPC213extends beyond one corresponding end of the first strap body210, and the other end of the power supply FPC213extends beyond the other end of the first strap body210. The power supply FPC213may include a power supply FPC2132extending into the first housing assembly10and connected to the motherboard80and/or the microphone assembly92, a power supply FPC neck portion2134received or further engaged in the through hole and connected to the first electrical connection portion2132, a power supply FPC body2136fixed in the first sub groove2105and the second sub groove2106, a movable portion2137passing through the first through hole and arranged outside the second sub groove2106, and a second electrical connection portion2138arranged at an end of the movable portion2137and connected to a battery35.

The first electrical connection portion2132includes a wiring portion2132aand a further wiring portion2132b. When the strap assembly20extends into the first housing assembly10, the wiring portion2132ais connected to the motherboard80, and the further wiring portion2132bis connected to the speaker assembly91.

As further shown inFIGS.8and9, a width of the power supply FPC neck portion2134is less than a width of each portion of the power FPC at two adjacent sides of the power supply FPC neck portion2134, for example, a width of the power supply FPC body2136. The power supply FPC neck portion2134is fixedly received or engaged in the first through hole to reduce a possibility that the power supply FPC213may be loose.

As shown inFIGS.8to9, a plurality of first insertion holes2135are defined in the power supply FPC body2136. When the power supply FPC body2136is received in the first sub groove2105and the second sub groove2106, the power supply FPC body2136is fixed by inserting the first restriction posts2109in the first insertion holes2135.

A shape of the protection sheet214is adapted to each of a shape of the first sub groove2105and a shape of the second sub groove2106, such that the protection sheet214may be accommodated in the corresponding first sub groove2105or the second sub groove2106. For example, the protection sheet214is accommodated in an innermost step of the second sub groove2106, and the first sub groove2105. A plurality of second insertion holes2140are defined in the protection sheet214. The protection sheet214is fixed by placing the first restriction posts2109in the second insertion holes2140. The protection sheet214is accommodated in the first sub groove2105and the second sub groove2106to directly contact the first body portion2101, so as to reduce a possibility of the power supply FPC body2136directly contacting with the first body portion2101.

A shape of the heat dissipation sheet215is similar to a shape of the power supply FPC213. The heat dissipation sheet215is arranged between the first strap cover211and the power supply FPC213, and may include a first attaching portion2152extending into the first housing assembly10, a first heat-dissipation neck portion2154received or further engaged in the through hole and connected to the first attaching portion2152, and a first heat-dissipation body2156fixed in the first sub groove2105and the second sub groove2106. For example, the first attaching portion2152may be attached to the speaker assembly91.

A width of the first heat-dissipation neck portion2154is less than a width of each portion of the heat dissipation sheet215at both sides of the first heat-dissipation neck portion2154, for example, a width of the first heat-dissipation body2156. As shown inFIG.6, it can be seen that the first heat-dissipation neck portion2154is fixedly received or engaged in the through hole, such that a possibility of the heat dissipation sheet215being loose may be reduced. Third insertion holes2158are defined in the first heat-dissipation body2156. When the first heat-dissipation body2156is arranged in the first sub groove2105and the second sub groove2106, the first heat-dissipation body2156may be fixed by placing the first restriction posts2109in the third insertion holes2158. The first fixing portion2108may be configured to cooperate with the second fixing portion2114to press tightly against the first heat-dissipation body2156between the first strap body210and the first strap cover211.

A filling216may be arranged between the heat dissipation sheet215and the first strap cover211. The filling216may be a foam and configured to fill space between the first strap cover211and first strap body210. The filling216may also be a thermally conductive material and configured to improve a heat conduction effect of the heat dissipation sheet215.

As shown inFIG.8andFIG.9, when assembling the first head strap21, the protection sheet214, the power supply FPC213and the heat dissipation sheet215are stacked in sequence to obtain a first assembly, such that the second insertion holes2140, the first insertion holes2135, and the third insertion holes2158are aligned with each other in sequence. Then, the first assembly is received in the first sub groove2105and the second sub groove2106of the first strap body210to allow the first restriction posts2109to pass through the second insertion holes2140, the first insertion holes2135and the third insertion holes2158in sequence. The first flexible strip212is embedded in and configured to cover the outermost step of the second sub groove2106, and the first flexible strip212and the second sub groove2106may be bonded by a glue, such that the first flexible strip212and the first body portion2101of the first strap body210may cooperatively define the first through hole at the position at which the notch2120is defined. In this way, the movable portion2137of the power supply FPC213may be able to pass through the first through hole. In addition, the power supply FPC neck portion2134of the power supply FPC213and the first heat-dissipation neck portion2154may be arranged inside the recess2102a. The filling216is arranged on the first body2111of the first strap cover211, and then the first strap cover211is buckled to the first strap body210to make the first connector2107be connected to the second connector2117. In addition, the first mounting portion2102is buckled to the first assembly portion2112to form a connecting portion. The connecting portion is configured to be connected to one corresponding end of the first housing assembly10. In this way, an assembly of the first head strap21is completed.

It can be understood that the first strap cover211is buckled to the first strap body210. The first strap cover211and a corresponding portion of the first strap body210may cooperatively define an accommodation cavity. Further, the accommodation cavity is defined by the first body portion2101being buckled to the first strap cover211at the position at which the first sub groove2105is located. The accommodation cavity may be configured to accommodate the protection sheet214, the power supply FPC213, the heat dissipation sheet215and the filling216. The second sub groove2106is fluidly coupled to the accommodation cavity.

As shown inFIG.10andFIG.11,FIG.10is a perspective assembly view of the second head strap22of the present disclosure, andFIG.11is a perspective exploded view of the second head strap22of the present disclosure. The second head strap22is similar to the first head strap21, and a difference between the second head strap22and the first head strap21is that the second head strap22is not arranged with the power supply FPC and the protection sheet. The second head strap22may include a second strap body220, a second strap cover221, a second flexible strip222, and a second heat dissipation sheet225. The second flexible strip222and the second heat dissipation sheet225may be pressed between the second strap body220and the second strap cover221. A structure of the second strap body220is substantially the same with a structure of the first strap body210, as shown inFIG.35for details, which will not be described in detail herein, and only main components of the second strap body220will be listed. Specific cooperating relationships and functions may refer to a description for the first strap body210. The second strap body220may include a second body portion2201and a second mounting portion2202. The second body portion2201includes a second length-adjusting hole2203, a second sawtooth wave2204, a first groove2205, and a second groove2206. A first connector2207may be arranged on each of two side edges of the second body portion2201near side walls of the first groove2205. A first fixing portion2208may be arranged on a wall of the first groove2205close to or adjacent to the second mounting portion2202. Two first connection holes2200are defined in the second mounting portion2202, and a recess2202ais defined between the two first connection holes2200. The first connection holes2200are configured to connect the second head strap22to a structure such as a protruding column on the first housing assembly10.

As shown inFIG.12,FIG.12shows a perspective exploded view of the second head strap22of the embodiments of the present disclosure from another view. A structure of the second strap cover221is substantially the same with a structure of the first strap cover211, which will not be described in detail herein, and only main components of the second strap cover221will be listed. Specific cooperating relationships and functions may refer to a description for the first strap cover211. The second strap cover221may include a second body2211and second assembly portion2212. The second body2211may include a second fixing portion2214, a second side wall2216, and a second connector2217. Two second connection holes2210are defined in the second assembly portion2212.

The second flexible strip222is made of a flexible material, may be bent arbitrarily, and may substantially be in a strip shape. A material of the second flexible strip222may be the same as a material of the second strap body220. The second flexible strip222may be adhered to a wall of the second groove2206of the second strap body220by means of gluing and the like, such that an outer surface of the second flexible strip222flushes with an outer surface of the second strap body220, that is, a surface close to the head of the user.

A structure of the second heat dissipation sheet225is substantially the same with a structure of the heat dissipation sheet215. The second heat dissipation sheet225may include a second attaching portion2252extending into the first housing assembly10, a second heat-dissipation neck portion2254received or engaged in the through hole and connected to the second attaching portion2252, and a second heat-dissipation body2256fixed in the first groove2205and the second groove2206. The second attaching portion2252may be attached to the speaker assembly91.

A width of the second heat-dissipation neck portion2254is less than a width of each portion of the heat dissipation sheet at both sides of the first heat-dissipation neck portion2154, for example, the second heat-dissipation body2256. As shown inFIG.6, it can be seen that the second heat-dissipation neck portion2254is fixedly received or engaged in the through hole, such that a possibility of the second heat dissipation sheet225being loose may be reduced.

When the second heat-dissipation body2256is arranged in the second groove2205and the second groove2206, the first fixing portion2208may be configured to cooperate with the second fixing portion2214to fix the second heat-dissipation body2256between the second strap body220and the second strap cover221.

A filling226may be arranged in a region of the second strap cover221where the second connector2217is arranged. The filling216is arranged between the second heat dissipation sheet225and the second strap cover221. The filling216may be a foam and configured to fill space between the second strap cover221and second strap body220. The filling226may also be a thermally conductive material and configured to improve a heat conduction effect of the second heat dissipation sheet225.

As shown inFIG.11toFIG.12, when assembling the second head strap22, the second heat dissipation sheet225is firstly arranged in the first groove2205and the second groove2206of the second strap body220. Then, the second flexible strip222is embedded in and configured to cover an outermost step of the second groove2206, and the second flexible strip222and the second groove2206may be bonded by the glue. After that, the second heat dissipation sheet2254is arranged in the recess2202a. At this moment, the filling226is arranged on the second strap cover221, and the second strap cover221is buckled to the second strap body220to make the first connectors2207be connected to the second connectors2217. In addition, the second mounting portion2202is buckled to the second assembly portion2212to form a connecting portion. The connecting portion is configured to be connected to one corresponding end of the first housing assembly10. In this way, an assembly of the second head strap22is completed.

It can be understood that the second strap cover221is buckled to the second strap body220. The second strap cover221and a corresponding portion of the second strap body220may cooperatively define an accommodation cavity. Further, the accommodation cavity is defined by the second body portion2201being buckled to the second strap cover221at the position of the first groove2205. The accommodation cavity may be configured to accommodate the second heat dissipation sheet225and the filling226. The second groove2206is fluidly coupled to the accommodation cavity.

When the first head strap21and the second head strap22are connected to the first housing assembly10, the first head strap21and the second head strap22may be connected to the first housing assembly10by engaging the first connection holes2100and the second connection holes2110with the structure such as the protruding column on the first housing assembly10.

It can be understood that the first head strap21and the second head strap22may also be integrated as one-piece structure, that is, configured as one head strap. For example, one end of the head strap may be overlapped with the other end of the head strap. A middle portion of the head strap may be connected to the host housing. A tightness adjustment of the strap assembly20may be completed by adjusting a length of an overlapped portion. In a case that the first head strap21and the second head strap22are configured as one head strap, other connection manners may also be adopted, which will not be limited herein.

In the present disclosure, a length of the strap assembly20may be a whole or total length of the first head strap21and the second head strap22after the first head strap21is connected to the second head strap22, that is, a length from an end of the first head strap21connected to the first housing assembly10to an end of the second head strap22connected to the first housing assembly10. The whole length has a relationship with an overlapping length between the first head strap21and the second head strap22. The shorter the overlapping length, the longer the whole length of the strap assembly20. The longer the overlapping length, the shorter the whole length of the strap assembly20. A length of the strap assembly20has a first state and a second state. The first state is a state that the overlapping length between the first head strap21and the second head strap22is the shortest, that is, a state that the whole length of the strap assembly20is the longest. The second state is a state that the overlapping length between the first head strap21and the second head strap22is the longest, is a state that the whole length of the strap assembly20is the shortest.

As shown inFIG.13andFIG.14,FIG.13shows a perspective exploded view andFIG.14shows a perspective assembly view of the second housing assembly30in an embodiment. The second housing assembly30may include a bottom front housing31, a bottom rear housing32and a connector33connecting the bottom front housing31and the bottom rear housing32. The second housing assembly30is configured to accommodate the strap assembly20and the tightness adjusting mechanism40.

As shown inFIG.15andFIG.16, the bottom front housing31may be made of a rigid material, and may include a first channel housing311and a first power supply housing312extending downwardly from the first channel housing311. As shown inFIG.17, the bottom rear housing32may be made of a rigid material, may include a second channel housing321corresponding to the first channel housing311and a second power supply housing322corresponding to the first power supply housing312. The battery35may be arranged inside the second power supply housing322. The second power supply housing322and the battery35arranged inside the second power supply housing322may constitute a power supply assembly. The second channel housing321and the second power supply housing322are separated from each other through a partition board3222.

After the bottom front housing31is buckled to the bottom rear housing32, the first channel housing311and the second channel housing321may cooperatively define a channel to receive the strap assembly20. After the first power supply housing312cooperates with the second power supply housing322, a space defined above the partition board3222may be defined as a first accommodation cavity, and a space defined below the partition board3222may be defined as a second accommodation cavity. The first accommodation cavity is fluidly coupled to the channel, and a first channel may be defined by the first accommodation cavity and the channel together. The first accommodation cavity may not only accommodate the first head strap21and the second head strap22which are overlapped each other, but also accommodate the tightness adjusting mechanism40to adjust a length of an overlapping portion between the first head strap21and the second head strap22. Therefore, a solid portion that defines the channel and the first accommodating cavity may also be defined as a housing (may also be defined as a first housing) for the head strap and the tightness adjusting mechanism. The second accommodation cavity is configured to accommodate a power source, such as the battery35, and may be defined as a power supply housing (may be defined as a second housing).

Understandably, after the bottom front housing31is engaged with the bottom rear housing32, the first power supply housing312, the second power supply housing322, and a body of the first channel housing311may be defined as a first housing, while a portion of the first channel housing311and the second channel housing321located on both sides of the first housing may be defined as the second housing.

Above-mentioned various terms, for example, the channel, the accommodation cavity, the first accommodation cavity, the second accommodation cavity, the first housing, the second housing, the housing for the head strap and the tightness adjusting mechanism, the power supply housing, may be adjusted based on an actual situation, and the present disclosure is not limited to the above terms. Terms of similar structures may be interchangeable based on the actual situation. For example, the channel may also be referred to as the first accommodation cavity, and in this case, the previous first accommodation cavity may be referred as the second accommodation cavity, the previous second accommodation cavity may be referred as a third accommodation cavity. Terms of the first housing and the second housing may also be interchangeable.

As shown inFIG.18,FIG.18shows a perspective exploded view of the tightness adjustment mechanism40in the embodiments of the present disclosure. The tightness adjusting mechanism40may include a first housing41, and a second housing engaged with the first housing41(in this case, the second housing may be the bottom rear housing32of the second housing assembly30described above, and the bottom rear housing32may be a common or share element of the tightness adjusting mechanism40and the second housing assembly30), a ratchet-pawl mechanism42, and a driving assembly44. The first housing41is engaged with the second housing to form a box. A body portion of the ratchet-pawl mechanism42and the driving assembly44may be accommodated in the box. The two head straps (i.e., the first head strap21and the second head strap22) of the strap assembly20may extend into an inner side of the box, and be overlapped with each other and further connected to the ratchet-pawl mechanism42. The length of the overlapping portion between the first head strap21and the second head strap22may be adjusted through the ratchet-pawl mechanism42. In the present embodiment, the second housing is not a necessary element, and the tightness adjusting mechanism40may also be obtained only through assembling the ratchet-pawl mechanism42to the first housing41.

As shown inFIG.19andFIG.20,FIG.19shows a perspective view of the first housing41, andFIG.20shows a perspective view of the first housing41from another view. The first housing41may include a bottom plate410. The bottom plate410may be a rectangular plate with a uniform thickness. A central hole4100is defined in a center of the bottom plate410.

Two side plates412may be arranged on two opposite long edges of the bottom plate410and further extend towards the second housing (i.e., the bottom rear housing32). A height of each of the side plates412is gradually decreased from a middle to both sides of the side plates412, such that a surface of each of the side plates412facing the second housing may be arc-shaped, such that the side plates412may be in close contact with the second housing.

As shown inFIG.21, the ratchet-pawl mechanism42may include a ratchet414arranged on the first housing41, a pawl assembly420engaged with and accommodated in the ratchet414, and a transmission gear430engaged with the pawl assembly420and configured to drive the pawl assembly420to rotate.

As shown inFIG.21, the pawl assembly420may include a first shielding plate421, a second shielding plate422fixedly connected to the first shielding plate421, a rotating plate423located between the first shielding plate421and the second shielding plate422, a first pawl424, a second pawl425, a first spring426, a second spring427, and an engaging gear428. The first pawl424, the second pawl425, the first spring426, and the second spring427may be assembled on the second shielding plate422. The engaging gear428may be fixedly arranged on a side of the second shielding plate422away from the first shielding plate421.

The first shielding plate421may be a circular plate. A central hole4210is defined in a center of the first shielding plate421. The central hole4210may be aligned with the central hole4100defined in the ratchet414. A center axis of the central hole4210is coaxial with a center axis of the central hole4100. A first connection portion4212and a second connection portion4214are arranged on a surface of the first shielding plate421facing towards the second shielding plate422. The second connection portion4214is in a prism shape, and the first connection portion4212is in a cylinder shape. Protruding ribbings are arranged on an outer peripheral wall of each of the first connection portion4212and the second connection portion4214, such that the protruding ribbings may cooperate with a corresponding structure of the second shielding plate422to make the first shielding plate421be fixedly connected to the second shielding plate422.

As shown inFIG.23, a shape of the second shielding plate422is the same with a shape of the first shielding plate421, and a size of the second shielding plate422is the same with a size of the first shielding plate421. A central hole4220is defined in a center of the second shielding plate422. The central hole4220may be aligned with the central hole4210of the first shielding plate421. A first buckling portion4222and a second buckling portion4224are arranged on a surface of the second shielding plate422facing towards the first shielding plate421. A shape of the second buckling portion4224is the same with a shape of the second connection portion4214of the first shielding plate421, but a size of the second buckling portion4224is different from a size of the second connection portion4214of the first shielding plate421, such that the second connection portion4214of the first shielding plate421may be inserted into the second buckling portion4224. The second buckling portion4224may include a first buckling wall4220aand a second buckling wall4220barranged at a certain angle to the first buckling wall4220a. That is, a distance between the first buckling wall4220aand the second buckling wall4220bgradually increases along a direction from the central hole4220to an outside. A shape of the first buckling portion4222is the same with a shape of the first connection portion4212of the first shielding plate421, but a size of the first buckling portion4222is different from a size of the first connection portion4212, such that the first connection portion4212of the first shielding plate421may be inserted into the first buckling portion4222. A first mounting shaft4225, a second mounting shaft4226, a first mounting frame4217, and a second mounting frame4228are further arranged on a surface of the second shielding plate422facing towards the first shielding plate421. The first mounting shaft4225may be configured to assemble the first pawl424. The second mounting shaft4226may be configured to assemble the second pawl425. The first mounting frame4217may be configured to assemble the first spring426. The second mounting frame4228may be configured to assemble the second spring427.

The first shielding plate421and the second shielding plate422may also be configured as one mounting element. The second buckling portion4224and the second connection portion4214may be configured as a limiting portion to engage with the rotating plate423, or may be configured as a fixing portion to fix the first shielding plate421with the second shielding plate422. The first buckling portion4222and the first connection portion4212are configured as another fixing portion to fix the first shielding plate421with the second shielding plate422.

The mounting element is not limited to a manner of the first shielding plate421and the second shielding plate422being assembled. Any component that allow the first pawl424and the second pawl425to contact and engage with the ratchet414may be taken as the mounting member. That is, a notch or a structure similar to the notch may be defined in the mounting element to enable the first pawl424and the second pawl425to extend out of a space defined by the mounting element and contact and cooperate with the ratchet414. Therefore, the mounting element may be a box defining the notch or the structure similar to the notch.

Of course, the mounting element may also be only the first shielding plate421or the second shielding plate422. For example, the mounting element is the second shielding plate422, and the second buckling portion4224and the second connection portion4214may be formed on the first shielding plate421or the second shielding plate422as the limiting portion.

The first mounting shaft4225is located on a side of the first buckling portion4222, the second mounting shaft4226is located on another side of the first buckling portion4222, and the first mounting shaft4225and the second mounting shaft4226are symmetrically arranged relative to the first buckling portion4222.

The first mounting frame4227and the second mounting frame4228are symmetrically arranged relative to the first buckling portion4222. A shape, a size, and a configuration of the first mounting frame4227are completely same with those of the second mounting frame4228, correspondingly.

As further shown inFIGS.23and24, the first mounting frame4227may include a first retaining wall4227a, a second retaining wall4227barranged at a certain angle to the first retaining wall4227a, and a connecting wall4227cconnecting an end of the first retaining wall4227ato an end of the second retaining wall4227b. The first retaining wall4227a, the second retaining wall4227b, and the connecting wall4227ccooperatively define a receiving space4227d. The receiving space4227dmay be configured to accommodate the first spring426. The first retaining wall4227ais configured to extend from an outer peripheral wall of the first buckling portion4222. A buckling shaft4227eis arranged on a side of the connecting wall4227cfacing towards the receiving space4227d, and the first spring426is sleeved on the buckling shaft4227e.

Since a configuration of the second mounting frame4228may be the same as that of the first mounting frame4227, the configuration of the second mounting frame4228will not be described in detail herein, and only components of the second mounting frame4228are listed. The second mounting frame4228may include a first retaining wall4228a, a second retaining wall4228b, a connecting wall4228c, a receiving space4228d, and a buckling shaft4228e. The first retaining wall4227aof the first mounting frame4227is connected to the first retaining wall4228aof the second mounting frame4228, and an end of the connecting wall4227cis connected to an end of the connecting wall4228c.

It should be pointed out that the first spring426and the second spring427may also be other elastic elements, such as tension springs, compression springs, objects providing extending and retracting forces, etc. In this way, the first pawl424and the second pawl425may be engaged with the ratchet414to complete switching between an engagement state and a non-engagement state. Correspondingly, the second mounting frame4227and the second mounting frame4228may also be replaced by other structures capable of fixing the elastic elements, based on differences of the elastic elements.

The rotating plate423is an eccentric wheel structure with a second through hole4230. Of course, the rotating plate423and the transmission gear430may also be integrated at a position of the second through hole4230. The second through hole4230is aligned with the central hole4220of the second shielding plate422, and an axis of the second through hole4230is coaxial with the central hole4220. In an embodiment, an inner surface of the second through hole4230may be polygonal, for example, hexagonal. A notch4232is defined at an end of the rotating plate423away from the second through hole4230, and has a same shape with a shape of the first buckling portion4222of the second shielding plate422, but has a size different from the first buckling portion4222. The size of the notch4232is greater than the size of the first buckling portion4222to accommodate the first buckling portion4222. In the present embodiment, the second buckling portion4224and the second connection portion4214are configured as the limiting portion to be engaged in the notch4232. The notch4232includes two opposite inner walls, that is, a first inner wall4232aand a second inner wall4232bopposite to the first inner wall4232a. A peripheral surface of the rotating plate423includes an outer wall surface4234. When the rotating plate23is rotated around an axis of the second through hole4230, only three states may exist between the rotating plate423and the second buckling portion4224. The three states include a first state, a second state, and a third state. In the first state, only the first inner wall4232acontacts with the first buckling wall4220a. In the second state, the rotating plate423is not contact with the second buckling portion4224(that is, a non-contact state). In the third state, only the second inner wall4232bcontacts with the second buckling wall4220b. That is, the limiting portion is configured to be in two states of being contacting or non-contacting with the inner wall surface of the notch4232, so as to make the rotating plate423be rotated a certain angle around a rotating axis (the axis of the second through hole4230) of the rotating plate423.

As shown inFIGS.23to25, the first pawl424is pivotally mounted on the first mounting shaft4225arranged on the second shielding plate422and may be rotated around the first mounting shaft4225. A pivot hole4240is defined at a middle position of the first pawl424, and the first mounting shaft4225is pivotally received in the pivot hole4240. The first pawl424has two opposite ends, that is, a first end4242connected to the first spring426and a second end4244abutting against the outer wall surface4234of the rotating plate423. A mounting shaft4242ais arranged at a side of the first end4242facing towards the receiving space4227dof the first mounting frame4227, and the first spring426may be sleeved on the mounting shaft4242a. A side of the first end4242away from the first mounting frame4227has a corner4242b, and the corner4242bis configured to be engaged with the inner teeth4140of the ratchet414(as shown inFIG.26). A side of the second end4244facing towards the rotating plate423has a contacting surface4244a. In an embodiment, the contacting surface4244ais curved, so as to be in a linear contact with the outer wall surface4234of the rotating plate423, to reduce a pressure between the contacting surface4244aand the outer wall surface4234.

The second pawl425and the first pawl424are symmetrically arranged relative to the first buckling portion4222of the second shielding plate422. A configuration of the second pawl425is same with a configuration of the first pawl424, and a shape of the second pawl425is same with a shape of the first pawl424, which will not be described repeated herein, and only the components of the second pawl425are listed. The second pawl425may define a pivot hole4250, and may include a first end4252, a second end4254, a mounting shaft4252a, a corner4252b, and a contacting surface4254a.

When assembling the first spring426, one end of the first spring426is sleeved on the buckling shaft4227ein the second mounting frame4227, and the other end of the first spring426is sleeved on the mounting shaft4242aof the first pawl424, such that the first spring426is assembled in the second mounting frame4227and the first pawl424may be rotated around the first mounting shaft4225. When the first pawl424is rotated, the first end4242of the first pawl424is driven to move, so as to push the first spring426to have compressions of different degrees in the second mounting frame4227.

Configuration and functions of the second spring427are the same as those of the first spring426, and the second spring427is mounted in the second mounting frame4228, which will not be repeated herein.

The outer wall surface4234of the rotating plate423is a curved surface, and configured as the following. When the rotating plate423is rotated around a rotating axis of the rotating plate423, the outer wall surface4234is configured to drive the first pawl424and the second pawl425to be rotated, so as to complete the switch between the engagement state and the non-engagement state. As shown inFIG.24, when no external force is applied to force the rotating plate423or the mounting element (a combination of the first shielding plate421and the second shielding plate422) to be rotated, when the rotating plate423and an outer surface of the limiting portion (i.e., an outer surface of the second buckling portion4224) are in the non-contact state due to actions of the first spring426and the second spring427, the rotating plate423and the ratchet414are in the engagement state. When the rotating plate423is forced to be rotated around the axis of the second through hole4230under the external force, two states in the following may occur.

(1) The non-contact state may be switched to the state of only the first inner wall4232acontacting with the first buckling wall4220a. In this case, in a direction of the rotating plate423being rotated around the axis of the through hole4230, a distance from a contact position of the first pawl424and the outer wall surface4234to the second through hole4230gradually increases, so as to make the first end4242of the first pawl424move and be disengaged from the inner teeth4140of an inner wall of the ratchet414. A distance from a contact position of the second pawl425and the outer wall surface4234to the second through hole4230gradually decreases, and the ratchet414compresses the second spring427of the second pawl425, such that the second pawl425may be disengaged from the inner teeth4140of the inner wall of the ratchet414. Eventually, the pawl assembly420may be disengaged from the ratchet414.

(2) The non-contact state may be switched to the state only the second inner wall4232bcontacting with the second buckling wall4220b. In this case, in the direction of the rotating plate423being rotated around the axis of the second through hole4230, the distance from the contact position of the second pawl425and the outer wall surface4234to the second through hole4230gradually increases, so as to make the second end4254of the second pawl425move and be disengaged from the inner teeth4140of the inner wall of the ratchet414. The distance from the contact position of the first pawl424and the outer wall surface4234to the second through hole4230gradually decreases, and the ratchet414compresses the first spring426of the first pawl424, such that the first pawl424may be disengaged from the inner teeth4140of the inner wall of the ratchet414. Eventually, the pawl assembly420may be disengaged from the ratchet414.

As shown inFIG.22, a central hole4280is defined in the engaging gear428, and aligned and coaxial with the central hole4220of the second shielding plate422. The engaging gear428is fixedly arranged at a side of the second shielding plate422away from the first shielding plate421.

As shown inFIG.27, when the strap assembly20is connected to the tightness adjusting mechanism40, the end of the first head strap21defining the first length-adjusting hole2103, is stacked or overlapped with the end of the second head strap22defining the second length-adjusting hole2203. In this case, the first sawtooth wave2104and the second sawtooth wave2204are located on two opposite sides in two stacked length-adjusting holes (i.e., the first length-adjusting hole2103and the second length-adjusting hole2203), respectively. The engaging gear428may be received in the two stacked length-adjusting holes (i.e., the first length-adjusting hole2103and the second length-adjusting hole2203) and configured to engage with the first sawtooth wave2104and the second sawtooth wave2204.

As shown inFIG.28, the transmission gear430may include a gear rotating disk431and a rotating shaft433. The rotating shaft433may extend from an inner surface of the gear rotating disk431. The rotating shaft433includes a first connection shaft4331connected to the gear rotating disk431, a second connection shaft4332connected to the first connection shaft4331, and a third connection shaft4333connected to the second connection shaft4332. The first connection shaft4331, the second connection shaft4332and the third connection shaft4333are coaxially arranged in sequence along an axis direction away from the gear rotating disk431.

When the engaging gear428is received in the two stacked length-adjusting holes (i.e., the first length-adjusting hole2103and the second length-adjusting hole2203) of two stacked head straps (i.e., the first head strap21and the second head strap22), the gear rotating disk431is configured to cooperate with the engaging gear428and the second shielding plate422, to limit positions of the first head strap21and the second head strap22, such that a possibility of the first head strap21and the second head strap22being disengaged from the engaging gear428may be reduced.

Both the first connection shaft4331and the third connection shaft4333may be circular shafts, that is, an outer peripheral surface of the first connection shaft4331and an outer peripheral surface of the third connection shaft4333are circular. An outer diameter of the first connection shaft4331is greater than an outer diameter of the third connection shaft4333. An outer peripheral surface of the second connection shaft4332is a polygon. In an embodiment, the outer peripheral surface of the second connection shaft4332is a hexagon, and a distance from a center of the hexagon to any side of the hexagon is less than a radius of the first connection shaft4331and greater than a radius of the third connection shaft4333. A shape and a size of the second connection shaft4332match with a shape and a size of the second through hole4230of the rotating plate423, such that the rotating plate423may be fixedly connected to the second connection shaft4332.

When an assembling process is performed for the strap assembly20, the second housing assembly30, and the tightness adjusting mechanism40, first the strap assembly20is assembled, and then the first head strap21and the second head strap22of the strap assembly20are configured to pass through one of the connectors33respectively. A portion where the first length-adjusting hole2103of the first head strap21is defined is overlapped with a portion where the second length-adjusting hole2203of the second head strap22is defined, and then the engaging gear428is received in the first length-adjusting hole2103and the second length-adjusting hole2203, the rotating plate423is configured to pass through the engaging gear428, the central hole4210, and the central hole4220defined in the second shielding plate422. The first pawl424, the second pawl425, the first spring426, the second spring427, and the rotating plate423are mounted on the second shielding plate422. For example, the rotating plate423is configured to pass through the third connection shaft4333of the rotating shaft433and then sleeved on the second connection shaft4332, such that the rotating plate423may be fixedly arranged relative to the rotating shaft433; besides, the second buckling portion4224on the second shielding plate422may be received in the notch4232of the rotating plate423. The first end4242of the first pawl424and the first end4252of the second pawl425may contact with the outer wall surface4234of the rotating plate423.

Then the first shielding plate421may be buckled to the second shielding plate422, and the first connection portion4212of the first shielding plate421is engaged with the first buckling portion4222of the second shielding plate422. In this way, the first shielding plate421is assembled with the rotating shaft433, and the first shielding plate421is fixedly arranged relative to the second shielding plate422, that is, the first shielding plate421and the second shielding plate422may be simultaneously radially rotated relative to the rotating shaft433. The first pawl424, the second pawl425, the first spring426, the second spring427, and the rotating plate423are fixed between the first shielding plate421and the second shielding plate422. The pawl assembly420is accommodated in the ratchet414, and the third connection shaft4333of the rotating shaft433is inserted into and further engaged with the central hole4100defined in the ratchet414. Then, the first housing41may be buckled with the bottom rear housing32. In this case, a bottom of the engaging gear428abuts against the gear rotating disk431, and the gear rotating disk431is configured to compress and limit positions of the first head strap21and the second head strap22(as shown inFIG.29). The side plates412are buckled and fixed with the bottom rear housing32to fix the first head strap21and the second head strap22in the tightness adjusting mechanism40. So far, an assembly of the strap assembly20and the tightness adjusting mechanism40is completed.

The bottom front housing31is assembled with the first head strap21after the battery35is placed. Subsequently, the two connectors33are assembled, so far, an assembly of the strap assembly20, the second housing assembly30and the tightness adjusting mechanism40may be completed.

When adjusting the strap assembly20, as shown inFIG.26, in an initial state, the first spring426is configured to raise the first pawl424to make the first end4252be engaged with the inner teeth4140of the ratchet414. The second spring427is configured to raise the second pawl425to make the first end4252be engaged with the inner teeth4140of the ratchet414. In this case, the first pawl424and the second pawl425contact with the rotating plate423, such that the rotating plate423does not contact with the second buckling portion4224. The strap assembly20may apply a force on the mounting element, such that when the mounting element is rotated in any direction, one pawl may be engaged with the inner teeth4140of the ratchet414. In this way, a limiting portion of the mounting element cannot contact the rotating plate423directly, and the first shielding plate421may be forced to be unable to perform a rotation and further be engaged with the strap assembly20, such that a possibility of the strap assembly20being loose may be reduced.

When adjusting a length of the strap assembly20, the transmission gear430is configured to drive the rotating plate423to be rotated, such that the non-contact state of the rotating plate423and the second buckling portion4224is switched to the state of only the first inner wall4232acontacting with the first buckling wall4220aor the state of only the second inner wall4232bcontacting with the second buckling wall4220b. Both the state of only the first inner wall4232acontacting with the first buckling wall4220aand the state of only the second inner wall4232bcontacting with the second buckling wall4220bmay cause the pawl assembly420to be disengaged from the ratchet414. Further, the first shielding plate421is driven to be rotated, such that the engaging gear428may be rotated, the first head strap21and the second head strap22may be moved in opposite directions, and a whole length of the strap assembly20may be changed. In this way, a tightness of the strap assembly20may be adjusted.

It may be understood that the first housing41may also be the bottom front housing31in the second housing assembly30, and the ratchet414may be arranged on a body of the first channel housing311, while the central hole4100may also be defined in the body of the first channel housing311, and the ratchet-pawl mechanism42may be engaged with the ratchet414. In addition, the first head strap21is overlapped with the second head strap22, the first head strap21and the second head strap22are further connected to the tightness adjusting mechanism40, and the tightness adjusting mechanism40is configured to adjust the overlapping length between the first head strap21and the second head strap22. In this case, a distance from the first strap cover211and the second strap cover221to the tightness adjusting mechanism40, a distance from the first strap cover211and the second strap cover221to the head straps, and a distance from the first strap cover211and the second strap cover221to the tightness adjusting mechanism housing may be adjusted accordingly. In some embodiments of the present disclosure, the bottom front housing31and the bottom rear housing32may serve as the housing of the tightness adjusting mechanism40, serve as a portion of the tightness adjusting mechanism40. Of course, the housing of the tightness adjusting mechanism may also be formed by the first housing41and the bottom rear housing32.

As shown inFIG.30,FIG.30is an assembly structural schematic view of a driving assembly of the tightness adjusting mechanism and a transmission gear. The driving assembly44may include a motor and a gearbox. The motor may be a stepping motor, an input end of the gearbox is connected to an output shaft of the stepping motor, and a gear at an output end of the gearbox is engaged with the transmission gear430, such that the transmission gear430may be driven to be rotated through the motor. A rotation of the transmission gear430may drive the pawl assembly420to be rotated, such that the engaging gear428may be rotated to drive the first head strap21and the second head strap22to move relative to each other.

As shown inFIG.1,FIG.1illustrates a perspective assembly view of the head-mounted device100according to an embodiment of the present disclosure. The force-bearing assembly50includes a first force-bearing component51arranged on the first housing assembly10and a second force-bearing component52arranged on the second housing assembly30. In some embodiments of the present disclosure, the first housing assembly10, the strap assembly20, the second housing assembly30, and the tightness adjusting mechanism40may form an annular frame having an adjustable tightness. The first force-bearing component51is located on a side of the annular frame, and the second force-bearing component52is located on an opposite side of the annular frame. For example, the first force-bearing component51is located on an upper side of the second housing assembly30, and the second force-bearing component52is located on a lower side of the second housing assembly30. The first force-bearing component51is inclined toward a side close to the second force-bearing component52. In addition, the first force-bearing component51is a first force-bearing point, the first housing assembly10is a second force-bearing point, and the second force-bearing component52is a third force-bearing point. The head-mounted device100may be stably supported and worn through the first force-bearing point, the second force-bearing point, and the third force-bearing point.

As shown inFIG.31andFIG.32,FIG.31illustrates a perspective view of the first force-bearing component51in an embodiment, andFIG.32illustrates a perspective view of the first force-bearing component51from another view in the embodiment. The first force-bearing component51may include a supporting plate511, a mounting plate512arranged substantially at a certain angle to the supporting plate511, a neck portion513located between the supporting plate511and the mounting plate512and configured to connect the supporting plate511and the mounting plate512, and a cushion514arranged on the supporting plate511. The cushion514is located at a level higher than a plane where the strap is located; in other words, the cushion514protrudes out of the plane where the strap is located.

The supporting plate511may be a quadrilateral plate, and a surface of the supporting plate511away from the second housing assembly30and the cushion514may be a curved surface. A surface of the supporting plate511where the cushion514is arranged may be a concave curved surface, to substantially match with a contour of a forehead of the user or a contour of a portion above the forehead. The supporting plate511extends from a side of the mounting plate512, and is inclined to a side where the cushion514is mounted, such that the mounting plate512may be arranged at an obtuse angle to the supporting plate511. The neck portion513may have a same extending direction with the supporting plate511, that is, the neck portion513extends from the side of the mounting plate512, such that the neck portion513may be arranged at an obtuse angle to the mounting plate512. The neck portion513may also be bent upward from the mounting plate512, such that the neck portion513may be arranged at a substantially right angle or an acute angle to the mounting plate512.

The mounting plate512may be a plate-shaped structure with a thickness, made of a rigid material, and configured to cooperate and be assembled with a top plate111of the main front housing11and the housing decoration component15. For example, the mounting plate512may be sandwiched between the top plate111and the housing decoration component15. The neck portion513may be made of a rigid material. A shape of the cushion514corresponds to a shape of the supporting plate511and is fixed on a side of the supporting plate511facing toward the second housing assembly30. The cushion514and the mounting plate512may be arranged two opposite sides of the supporting plate511respectively.

As shown inFIG.33,FIG.33illustrates a perspective exploded view of the second force-bearing component52of the force-bearing assembly50and the bottom front housing31of the second housing assembly30in an embodiment. The second force-bearing component52is fixed and mounted on the bottom front housing31of the second housing assembly30. As shown inFIGS.34to35,FIG.34illustrates a perspective exploded view of the second force-bearing component52in an embodiment, andFIG.35illustrates a perspective assembly view of the second force-bearing component52in the embodiment. The second force-bearing component52may include a fixing plate521and a cushion522covering/surrounding/encompassing the fixing plate521. A shape of the fixing plate521may match with a shape of the first power supply housing312of the bottom front housing31of the second housing assembly30. A size of the fixing plate521may match with a size of the first power supply housing311of the bottom front housing31. The second force-bearing component52may be configured to be fixed on the second housing assembly30by means of a snap/buckling/engagement. The second force-bearing component52may also be bonded on the second housing assembly30by the glue.

When the user wears the head-mounted device100, since the strap assembly20connects the first housing assembly10and the second housing assembly30to form a wearable annular frame, the second force-bearing component52and the first housing assembly10are configured as main force-bearing points, and the first housing assembly10is configured to contact with the forehead of the user and the second force-bearing component52is configured to contact with a back of the head of the user, the user may support the head-mounted device100through the forehead and the back of the head of the user. Since the first force-bearing component51is disposed at an upper of the forehead and inclined toward the second force-bearing component52, and contacts with the upper of the forehead of the user, the head-mounted device100may be supported stably, such that the user may feel more comfortable to wear.

The first sensor is arranged on the second force-bearing component52and configured to detect a deformation parameter value of the cushion522. The deformation parameter value of the cushion522may include a thickness of the cushion522, a density of the cushion522, and a light transmittance of the cushion522, or other deformation parameters.

In the present embodiment, the parameter of the cushion522is the thickness of the cushion522. For example, as shown inFIG.34, the first sensor may include a first sensing device941and a first magnet942. The first sensing device941may be a Hall switch and configured to determine the thickness of the cushion522through detecting a magnetic field generated by the first magnet942. Specifically, the first magnet942may be arranged on a side of the cushion522away from the fixing plate521(as shown inFIGS.1and6), and the Hall switch may be arranged on a side of the fixing plate521close to the cushion522. In some embodiments, the first magnet942may also be arranged in the cushion522, such that a surface of the cushion contacting with a human body may be kept soft and comfortable and not be affected by the by the Hall switch. In this case, the first sensor is configured to detect a thickness of a part of the cushion between the first magnet942and the Hall switch. It can be understood that, in other embodiments, the first magnet942may also be arranged on the fixing plate521, and the Hall switch may be arranged on the cushion522. In some embodiments, the Hall switch may include a Hall element, an amplifier circuit, a temperature compensation circuit, and a regulated power supply circuit integrated on one chip. The Hall element is generally made of a semiconductor wafer and have advantages such as being sensitive to magnetic fields, having a simple structure, having a small size, having a wide frequency response, having a large output-voltage variation and a long service life, and the like. A control current I is provided between two terminals of the Hall element wafer, and a uniform-intensity magnetic field having a magnetic induction intensity B is applied in a vertical direction of the Hall element wafer through a magnet. In this way, a potential difference (that is, a Hall voltage UH) may be generated in a direction substantially perpendicular to the current and the uniform-intensity magnetic field. A relationship between the current I, the magnetic induction intensity B and the Hall voltage UH can be defined as UH=k IB/d, where d is a thickness of the Hall element wafer, k is a Hall coefficient, and a value of k has a relationship with a material of the Hall element wafer. In a case that k, d, I remain unchanged, UH varies with B, and B is related to a distance between the Hall element and the magnet (that is, the thickness of the cushion in the present embodiment). Therefore, the thickness of the cushion may be determined based on the Hall voltage detected by the Hall switch.

Specifically, when the deformation parameter value of the cushion522detected by the first sensor reaches a preset threshold, the tightness adjusting mechanism40is configured to stop adjusting the length of the strap assembly20. For example, a thickness of the cushion522in a natural state is 1 cm, a preset threshold of the thickness of the cushion522is 0.5 cm. When the thickness of the cushion522detected by the first sensor is reduced to or less than 0.5 cm, the tightness adjusting mechanism40is configured to stop adjusting the length of the strap assembly20. For example to illustrate, when the user wears the head-mounted device100, a length of the strap assembly20is reduced until the head-mounted device100can be stably tied to the head of the user, the thickness of the cushion522at this moment is obtained and taken as the preset threshold of the thickness of the cushion522. Of course, in other embodiments, when the head-mounted device100can be tied stably to the head of the user and the user feels more comfortable to the tightness of the strap assembly20of the head-mounted device100, the thickness of the cushion522at this moment may be set to be the preset threshold of the thickness of the cushion522.

The second sensor is configured to detect the length of the strap assembly20. For example, the second sensor is configured to detect whether the strap assembly20is extended to be in the first state or retracted to be in the second state. As shown inFIG.17andFIG.27, the second sensor includes a second magnet951, a second sensing device952, and a third sensing device953. The second sensing device952and the third sensing device953may be Hall elements. Specifically, the second magnet951is fixed on the second head strap22, and the second sensing device952is arranged on the second channel housing321of the second housing assembly30. When the strap assembly20is extended to be in the first state, that is, when the overlapping length between the first head strap21and the second head strap22is the shortest, the second sensing device952corresponds to the second magnet951. The third sensing device953is arranged on the second channel housing321of the second housing assembly30, when the strap assembly20is shortened to be in the second state, that is, when the overlapping length between the first head strap21and the second head strap22is the longest, the third sensing device953corresponds to the second magnet951.

In some embodiments, when the strap assembly20is extended to be in the first state or retracted to be in the second state, the second magnet951is located in the second channel housing321, and both the second sensing device952and the third sensing device953are arranged on an inner wall of the second channel housing321of the second housing assembly30.

When the length of the strap assembly20reaches the first state, the tightness adjusting mechanism40is configured to stop adjusting the length of the strap assembly20. When the length of the strap assembly20reaches the second state, the tightness adjusting mechanism40is configured to stop adjusting the length of the strap assembly20. In some embodiments of the present disclosure, by arranging the second sensor to detect whether the strap assembly20is extended to the longest or retracted to the shortest, when the strap assembly20is extended to the longest or retracted to the shortest, the tightness adjusting mechanism40is configured to stop adjusting the length of the strap assembly20to reduce a possibility of rotation jam.

The controlling switch is connected to the tightness adjusting mechanism40. The user may initiate an adjustment of the tightness adjusting mechanism40for the length of the strap assembly20through triggering the controlling switch. For example, when the user switches on the controlling switch to make the controlling switch be in a first controlling state, the tightness adjusting mechanism40is configured to perform an elongation adjusting process to increase the length of the strap assembly20. When the user switches on the controlling switch to make the controlling switch be in a second controlling state, the tightness adjusting mechanism40is configured to perform a contraction adjusting process to decrease the length of the strap assembly20.

At least the second force-bearing component52, the first sensor, and the tightness adjusting mechanism40in the above-mentioned embodiments may be defined as a tightness adjusting device configured to adjust the whole length of the strap assembly20.

In some embodiments, the controlling switch may be a power key of the head-mounted device100. For example, when the user presses the power key to instruct to turn on the head-mounted device100, the tightness adjusting mechanism40is configured to perform the elongation adjusting process to increase the length of the strap assembly20. Of course, the controlling switch may also be a volume key of the head-mounted device100. For example, a volume of the head-mounted device100may be adjusted by a short press for the volume key, and an adjustment of the length of the strap assembly20may be initiated through a long press for the volume key. The present disclosure may simplify a structure of the head-mounted device100by sharing a pressing key.

It is worth mentioning that, in some embodiments, the user may also perform a fine tune for the strap assembly20, that is, the user may initiate a fine-tuning switch, after the head-mounted device is stably worn on the head, so as to satisfy requirements of the user for wearing comfort. For example, when the user wears the head-mounted device, a stepper motor in the driving assembly44is configured to rotate at a full step angle to shorten the second head strap22. When the thickness of the cushion522is decreased and reaches the preset threshold of the thickness of the cushion522, the stepper motor is configured to stop rotating. In this case, when the user turns on the fine-tuning switch again, or adjusts the controlling switch to be in a third state, the stepper motor may be configured to rotate at a half-step angle to shorten or lengthen the length of the strap assembly20, so as to realize a fine tune, until the user turns off the fine-tuning switch. In this way, the length of the strap assembly20may not only make the head-mounted device stably worn on the head of the user, but also make the user feel comfortable, such that the head-mounted device may be suitable for users having different head shapes or different experience requirements.

In some embodiments of the present disclosure, a strap-adjusting device may be further provided, and the strap-adjusting device may be configured to adjust a length of a strap of the wearable device. Specifically, the strap-adjusting device may include a pressing piece, a first sensor, and a tightness adjusting mechanism. The pressing piece may be connected to the strap. The first sensor may be arranged on the pressing piece. The tightness adjusting mechanism may be cooperatively connected to the strap. Specifically, the pressing piece may include a supporting plate and a cushion, and the supporting plate may be connected directly to the strap. The strap may be the strap assembly in the above-mentioned embodiments, and structures of the first sensor and the tightness adjusting mechanism may be as described in the above-mentioned embodiments, which will not be repeated. It worth mentioning that, a connection between the supporting plate and the strap may be a direct connection or an indirect connection. For example, the supporting plate is directly glued to the strap, or two ends of the supporting plate are respectively connected to the strap, or, as described above, the supporting plate is fixed on the second housing assembly30and the strap is configured to be cooperatively connected to the tightness adjusting mechanism of the second housing assembly30, so as to realize the indirect connection between the supporting plate and the strap.

As described in the above embodiments, the pressing piece may be the second force-bearing component52in the above embodiments. In some other embodiments, the pressing piece may also be the first force-bearing component51; in this case, the supporting plate of the pressing piece is the supporting plate511of the first force-bearing component51, and the cushion of the pressing piece is the cushion514of the first force-bearing component51. In other embodiments, the pressing piece may be obtained by arranging the cushion on the first housing assembly10; in this case, the first housing assembly10is equivalent to the supporting plate of the pressing piece. In another embodiment, the pressing piece may be obtained by arranging the cushion on the second housing assembly30; in this case, the second housing assembly30is equivalent to the supporting plate of the pressing piece.

According to another aspect of the present disclosure, a strap-adjusting device is further provided and configured to adjust the length of the strap of the wearable device. Specifically, the strap-adjusting device may include a housing connected to the strap, a cushion arranged on the housing, a first sensor arranged on at least one of the housing or the cushion and configured to detect a deformation parameter value of the cushion, a tightness adjusting mechanism cooperatively connected to the strap and configured to adjust the length of the strap, and a processor configured to control the tightness adjusting mechanism to adjust the length of the strap in response to the deformation parameter value of the cushion detected by the first sensor.

Specifically, the strap may be the strap assembly20in the above-mentioned embodiments, and the housing may be the first housing assembly10, the second housing assembly30, or other housings connected to the strap assembly20in the above-mentioned embodiments. The structures of the cushion, the first sensor, and the tightness adjusting mechanism may be the same as those described in any of the above embodiments, which will not be repeated here.

The processor is configured to control the tightness adjusting mechanism to stop adjusting the length of the strap in response to the deformation parameter value of the cushion reaching a preset threshold.

In some embodiments, the strap has a first state in which the strap has the longest length and a second state in which the strap has the shortest length, the strap adjusting device may further include a second sensor connected to the processor and configured to detect whether a length of the strap is in the first state or the second state. The processor is configured to control the tightness adjusting mechanism to stop adjusting the length of the strap in response to the length of the strap being in the first state or the second state.

As shown inFIG.36, the first sensor94, the second sensor95and the tightness adjusting mechanism40are connected to the processor96. The first sensor94is configured to send information of a detected deformation parameter value of the cushion to the processor96. When the deformation parameter value of the cushion reaches the preset threshold, the processor96is configured to control the tightness adjusting mechanism40to stop adjusting the length of the strap assembly20. The second sensor95is configured to send the detected state information of a length of the strap assembly20to the processor96. When the length of the strap assembly20is in a state of being extending to the longest or in a state in which the strap has the shortest length, the processor96is configured to control the tightness adjusting mechanism40to stop adjusting the length of the strap assembly20.

In some embodiments, the strap adjusting device may further include a controlling switch connected to the processor. The processor is configured to control the tightness adjusting mechanism to perform an elongation adjusting process to increase the length of the strap in response to the controlling switch being in a first controlling state. The processor is further configured to control the tightness adjusting mechanism to perform a contraction adjusting process to decrease or shorten the length of the strap in response to the controlling switch being in a second controlling state.

In some embodiments, as shown inFIG.37, the processor96may include an MCU (Microprogrammed Control Unit)961and a logic circuit962. A controlling switch97is connected to the MCU961. The first sensor94may include a first sensing device941and a first magnet, and the second sensor95may include a second magnet, a second sensing device952and a third sensing device953. The first sensing device941, the second sensing device952and the third sensing device953are connected between the MCU961and the logic circuit962. The driving assembly44in the tightness adjusting mechanism40are respectively connected to the MCU961and the logic circuit962. In some embodiments, the first sensing device941, the second sensing device952and the third sensing device953may all be Hall elements, and the first sensing device941is configured to determine a thickness of the cushion by detecting a magnetic field of the first magnet. The second magnet951and the second sensing device952are configured to determine a stretching state of the strap assembly20by detecting a magnetic field of the second magnet.

Taking the head-mounted device100of the above-mentioned embodiments as an example, an adjusting principle of the tightness adjusting mechanism of the present disclosure will be described in the following. When the head-mounted device100is not in use, the strap assembly20of the head-mounted device100is in the first state in which the strap has the longest length.

After the user wears the head-mounted device100on the head, the user first triggers the controlling switch97to make the controlling switch97be in the second controlling state. After receiving a signal corresponding to the second controlling state sent from the controlling switch97, the processor96is configured to control the first sensing device941and the third sensing device953to start detecting, and simultaneously send an adjusting signal of rotating along a first direction to the driving assembly44(e.g. a motor of the driving assembly44) of the tightness adjusting mechanism40to control the driving assembly44to be rotated along the first direction, such that the engaging gear428is driven by the transmission gear430to be rotated along the first direction, so as to drive the first head strap21and the second head strap22to move towards each other. In this way, the overlapping length between the first head strap21and the second head strap22may be increased to reduce the whole length of the strap assembly20. At this time, the motor of the driving assembly44is configured to feed rotation information of the driving assembly44back to the MCU961, the first sensing device941is configured to feed detection information of the first sensing device941back to the MCU961, and the third sensing device953is configured to feed detection information of the third sensing device953back to the MCU961.

As the whole length of the strap assembly20is gradually shortened, the cushion522is gradually pressed between the head of the user and the fixing plate521. The cushion522is subjected a pressing force to be deformed, and the thickness of the cushion522is gradually reduced. When the thickness of the cushion522is reduced to the preset threshold of the thickness of the cushion522, for example, reduced to 0.5 cm, then the logic circuit962is configured to send a controlling signal to control the motor of the driving assembly44to stop rotating, such that the engaging gear428may stop rotating, and the first head strap21and the second head strap22may stop moving; in this way, the compression or contraction of the strap assembly20may be stopped. The motor of the driving assembly44is simultaneously configured to feed information of stopping rotating back to the MCU.

It can be understood that, when the user does not wear the head-mounted device100on the head, but directly triggers the controlling switch97to make the controlling switch97be in the second controlling state, a control process of the processor96is similar to a control process mentioned above, and a difference is the following. Since the head-mounted device100is not worn on the head of the user, the cushion522is not pressed, therefore the thickness of the cushion522detected by the first sensing device941remains changed, until the whole length of the strap assembly20is gradually reduced to the shortest. At this moment, the third sensing device953detects that the strap assembly20is in the second state, then the logic circuit962is configured to send the controlling signal to control the motor of the driving assembly44to stop rotating, so as to make the engaging gear428stop rotating, and a possibility of a rotation jam of the first head strap21and the second head strap22may be reduced. At the same time, the motor of the driving assembly44is configured to feed information of stopping rotating back to the MCU.

When the user wants to take off the head-mounted device100from the head, the user first triggers the controlling switch97to make the controlling switch97be in the first controlling state. After receiving a signal corresponding to the first controlling state sent from the controlling switch97, the processor96is configured to control the second sensing device952to start detecting, and simultaneously send the adjusting signal of rotating along a second direction to the driving assembly44(e.g. the motor of the driving assembly44) of the tightness adjusting mechanism40. The second direction is opposite to the first direction. As a result, the engaging gear428is driven by the transmission gear430to be rotated along the second direction, so as to drive the first head strap21and the second head strap22to move away from each other. In this way, the overlapping length between the first head strap21and the second head strap22may be reduced to increase the whole length of the strap assembly20. Simultaneously, the motor of the driving assembly44is configured to feed rotation information of the driving assembly44back to the MCU961, and the second sensing device952is configured to feed detection information of the second sensing device952back to the MCU961.

As the whole length of the strap assembly20is gradually increased, when the whole length of the strap assembly20is increased to a certain length, the user may take off the head-mounted device100from the head of the user. The length of the strap assembly20continue to be increased until the strap assembly20is extended to the longest. In the case, the second sensing device952detects that the strap assembly20is in the first state, and then the logic circuit962is configured to send the controlling signal to control the motor of the driving assembly44to stop rotating, such that the engaging gear428stops rotating, and the first head strap21and the second head strap22are driven to stop moving away from each other. In this way, a possibility of the rotation jam of the first head strap21and the second head strap22may be reduced. The motor of the driving assembly44is simultaneously configured to feed information of being stopped to be rotated back to the MCU.

In conclusion, in some embodiments of the present disclosure, by detecting the thickness of the cushion through the first sensor, and adjusting the length of the strap through the tightness adjusting mechanism based on the thickness of the cushion detected by the first sensor, it is possible to realize an automatic adjustment for the strap. In this way, an adjustment of the length of the strap may be more comfortable, and the user experience may be better.

The above is preferred embodiments of the present disclosure, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present disclosure, may also make some improvements and modifications, which should be also considered within the protection scope of the present disclosure.