Patent ID: 12214229

DETAILED DESCRIPTION

Hereinafter, a mask apparatus of the present disclosure will be described in detail with reference to the drawings.

FIG.1is a left perspective view showing an example of a mask apparatus,FIG.2is a right perspective view of the mask apparatus,FIG.3is a rear view of the mask apparatus, andFIG.4is a bottom view of the mask apparatus.

Referring toFIGS.1to4, a mask apparatus1can include a mask body10and a mask body cover20coupled to the mask body10.

The mask body10and the mask body cover20can be detachably coupled to each other. When the mask body10and the mask body cover20are coupled to each other, an inner space can be defined between the mask body10and the mask body cover20. Constituents for driving the mask apparatus1can be disposed in the inner space. The inner space can be defined between a front surface of the mask body10and a rear surface of the mask body cover20. The mask body10can define a rear surface of the mask apparatus1, and the mask body cover20can define a front surface of the mask apparatus1.

A rear side of the mask apparatus1is defined as a direction in which the rear surface of the mask apparatus1facing a user's face is disposed, and a front side of the mask apparatus1is defined as a direction which is opposite to the rear side and in which a front surface of the mask apparatus, which is exposed to the outside, is disposed.

The mask apparatus1can further include a sealing bracket30and a seal40that is detachably coupled to the sealing bracket30.

The sealing bracket30can be detachably coupled to a rear surface of the mask body10to fix the seal40to the rear surface of the mask body10. In some examples, when the sealing bracket30is separated from the rear surface of the mask body10, the seal40can be separated from the mask body10.

The seal40can be supported on the rear surface of the mask body10by the sealing bracket30, and a breathing space S for breathing can be defined between the seal40and the rear surface of the mask body10. The seal40can be in close contact with a user's face and can surround user's nose and mouth to restrict introduction of external air into the suction space.

The mask body cover20can include a first filter mounting portion21and a second filter mounting portion22. The first filter mounting portion21can be disposed at a right side of the mask body cover20, and the second filter mounting portion22can be disposed at a left side of the mask body cover20.

A left direction (left side) and a right direction (right side) are defined based on the mask apparatus1worn on the user's face. That is, in the state in which the user wearing the mask apparatus1, a right side of the user is defined as the right side of the mask apparatus1, and a left side of the user is defined as the left side of the mask apparatus1.

In some examples, an upward direction (upward side) and a downward direction (downward side) are defined based on the mask apparatus1mounted on the user's face.

A first filter cover25can be mounted on the first filter mounting portion21, and a second filter cover26can be mounted on the second filter mounting portion22. Filters23and (seeFIG.5) can be disposed inside the first filter mounting portion21and the second filter mounting portion22, and the first filter cover25and the second filter cover26can cover the filter.

The first filter cover25and the second filter cover26can be detachably coupled to the first filter mounting portion21and the second filter mounting portion22. For example, the first filter cover25and the second filter cover26can be coupled to be fitted into the first filter mounting portion21and the second filter mounting portion22, respectively.

Each of the first filter cover25and the second filter cover26can include a front surface portion and side surface portions extending backward along an edge of the front surface portion or an edge of a rear surface.

Each of the side surface portions of the first filter cover25and the second filter cover26can have four side surfaces, and the four side surfaces can include an upper side surface, a lower side surface, a left side surface, and a right side surface.

One or a plurality of first air inlets251can be defined in the side surface portion of the first filter cover25. One or a plurality of second air inlets261can also be defined in the side surface portion of the second filter cover26.

In the state in which the first filter cover25is mounted on the first filter mounting portion21, the first air inlet251can be defined to be exposed to the outside. In the state in which the second filter cover26is mounted on the second filter mounting portion22, the second air inlet261can be defined to be exposed to the outside.

The first air inlet251and the second air inlet261can be defined in the side surfaces of the first filter cover25and the second filter cover26, respectively. It should be noted that each of the first and second air inlets251and261are respectively defined in the front surface portions of the first and second filter covers25and26.

The first air inlet251and the second air inlet261can be defined at a point closer to the front surface portion from a line that bisects the side surface portion.

When a plurality of the first air inlets251are provided in the side surface portions of the first filter cover25, the first air inlets251can include a first air suction hole251adefined in the right side surface, a second air suction hole251bdefined in the left side surface, and a third air suction hole251cdefined in the upper side surface.

Similarly, when a plurality of the second air inlets261are provided in the side surface portions of the second filter cover26, the second air inlets261can include a first air suction hole261adefined in the left side surface, a second air suction hole261bdefined in the right side surface, and a third air suction hole261cdefined in the upper side surface.

An opening250can be defined in one of the first filter cover25and the second filter cover26, and the opening250can be defined in an edge of one of the first filter cover25and the second filter cover26. In some examples, a manipulation portion195for controlling an operation of the mask apparatus1can be mounted in the opening250. In some implementations, the manipulation portion195is mounted on the first filter cover25as an example.

The manipulation portion195can serve as a manipulation switch that turns on/off power of the mask apparatus1. The manipulation portion195can be exposed to the front side of the mask apparatus1while being mounted in the opening250.

The mask body10can include a hook mounting portion108. The hook mounting portion108can be provided on the left and right sides of the mask body10.

That is, the hook mounting portion108can include a first hook mounting portion108aprovided at a right side of the mask body10, and a second hook mounting portion108bprovided at a left side of the mask body10.

Each of the first hook mounting portion108aand the second hook mounting portion108bcan be provided in plurality to be spaced apart from each other in a vertical direction of the mask body10. In detail, the first hook mounting portion108acan be provided at each of the upper right and lower right sides of the mask body10, and the second hook mounting portion108bcan be provided at each of the upper left and lower left sides of the mask body10.

A band for maintaining the mask apparatus1in close contact with the user's face can be mounted on the hook mounting portion108.

For example, both ends of the band can connect the first hook mounting portion108ato the second hook mounting portion108bor connect each of two first hook mounting portions108aspaced apart from each other in the vertical direction and each of the plurality of second hook mounting portions108bspaced apart from each other in the vertical direction to each other.

In the former case, the band can have a shape surrounding the user's occipital region, and in the latter case, the band can have a shape that is hooked on both ears of the user.

The hook mounting portion108can be formed by cutting a portion of the mask body10. Thus, air can be introduced into the inner space between the mask body10and the mask body cover20through a gap defined in the hook mounting portion108.

In detail, the external air introduced into the inner space through the hook mounting portion108can cool electronic components disposed in the inner space. In some examples, the air of which a temperature increases while cooling the electronic components can be discharged again to the outside of the mask body10through the hook mounting portion108. In some examples, to restrict a flow of the air introduced into the inner space through the hook mounting portion108into the breathing space, the inside of the mask apparatus1can have a sealing structure.

The mask body10can include an air outlet129for supplying the filtered air to the breathing space. The user can breathe while breathing the filtered air supplied through the air outlet129to the breathing space.

The air outlet129can include a first air outlet129athrough which the filtered air introduced into the first air inlet251is discharged to the suction space and a second air outlet129bthrough which the filtered air introduced into the second air inlet261is discharged to the suction space.

The first air outlet129acan be defined at a right side with respect to a center of the mask body10, and the second air outlet129bcan be defined at a left side with respect to the center of the mask body10. The air introduced through the first air inlet251can pass through the filter23and then flow to the first air outlet129a. The air introduced through the second air inlet261can pass through the second filter24and then flow to the second air inlet261.

The mask body10can include air exhaust holes154and155for discharging air exhaled by the user to an external space. The air exhaust holes154and155can be defined in a lower portion the mask body10.

The air exhaust holes154and155can include a first air exhaust hole154defined in a front lower end of the mask body10and a second air exhaust hole155defined in a bottom surface of the mask body10.

In detail, a rib extending forward can be formed at the front lower end of the mask body10, and a surface defined by the rib can be defined as the bottom surface of the mask body10.

A flow space through the air flowing toward the second air exhaust hole155by passing through the first air exhaust hole154descends can be defined between the mask body10and the mask body cover20.

A check valve can be provided in one or more of the first air exhaust hole154and the second air exhaust hole155. The external air can be introduced into the breathing space, or the air discharged through the second air exhaust hole155can be restricted from flow backward by the check valve.

The check valve can be disposed in the flow space between the first air exhaust hole154to the second air exhaust hole155.

For example, the check valve having the form of a flat flap with a size and shape corresponding to the size and shape of the first air exhaust hole154can be provided.

In detail, an upper end of the flap can be connected to an upper edge of the first air exhaust hole154, and when the user exhales, the flap can be bent or rotates to open the first air exhaust hole154, and when the user inhales, the flap can be in close contact with the first air exhaust hole154to block the external air or the discharged air from being introduced again into the breathing space.

The mask body10can include a sensor mounting portion109. The sensor mounting portion109can be equipped with a sensor for acquiring various pieces of information from the breathing space. The sensor mounting portion109can be disposed above the mask body10. When the user breathes, the sensor mounting portion109can be disposed above the mask body10in consideration of a position at which a pressure change in the breathing space is constantly sensed.

The mask body10can include a connector hole135. The connector hole135can be understood as an opening in which a connector192for supplying power to the mask apparatus1is installed. The connector hole135can be defined at either a left edge or a right edge of the mask body10.

In some implementations, since the manipulation portion195and the connector192are connected to a power module19(seeFIG.5) to be described later, the connector hole135can be provided at one side of the left or the right side of the mask body10, which corresponds to the position at which the power module19is installed.

Hereinafter, constituents of the mask apparatus1will be described in detail based on an exploded perspective view.

FIG.5is an exploded perspective view of the mask apparatus.

Referring toFIG.5, the mask apparatus1can include the mask body10, the mask body cover20, the sealing bracket30, and the seal40.

In detail, the mask body10and the mask body cover20can be coupled to each other to form an outer appearance of the mask apparatus1.

An inner space for accommodating components for the operation of the mask apparatus1can be defined between the mask body10and the mask body cover20. The sealing bracket30and the seal40can be coupled to the rear surface of the mask body10to define the breathing space between the user's face and the mask body10and to block introduction of the external air to the breathing space.

The mask body10can include a cover coupling groove101. The cover coupling groove101can be defined along a front edge of the mask body10. The cover coupling groove101can be defined by a height difference. The cover coupling groove101can be defined to correspond to an edge of the mask body cover20. The cover coupling groove101can be defined by recessing a portion of the front surface of the mask body10backward. The mask body cover20can move toward the cover coupling groove101of the mask body10to allow the mask body cover20to be inserted into the cover coupling groove101.

The mask body10can include a first cover coupling portion102. An upper portion of the mask body cover20can be supported on the first cover coupling portion102. The first cover coupling portion102can be disposed on a front upper portion of the mask body10.

For example, the first cover coupling portion102can have a structure that is capable of being hook-coupled. The hook coupled to the first cover coupling portion102can be disposed on a rear surface of the mask body cover20.

The first cover coupling portion102can be provided in plurality, and the hook can also be provided in plurality to correspond to the first cover coupling portions102. In some implementations, the first cover coupling portion102can be provided at the left and right sides of the mask body10based on the center of the mask body10. The first cover coupling portion102can be referred to as an upper cover coupling portion.

The mask body10can include a first bracket coupling portion103.

The first bracket coupling portion103can support an upper portion of the sealing bracket30. The first bracket coupling portion103can be disposed above a rear surface of the mask body10. For example, the first bracket coupling portion103can be provided in the form of a hook that protrudes backward from the rear surface of the mask body10. A first body coupling portion304coupled to the first bracket coupling portion103can be disposed on the sealing bracket30.

The first body coupling portion304can be provided in plurality to correspond to the plurality of first bracket coupling portions103. The mask body10can include a support rib104.

The support rib104can be provided to protrude forward from the front surface of the mask body10. The support rib104can contact the rear surface of the mask body cover20when the mask body cover20is coupled to the mask body10.

The mask body10and the mask body cover20can resist external forces acting in a front and rear direction by the support rib104. The support ribs104can be provided in a plurality on the front surface of the mask body10.

The mask body10can include a second cover coupling portion106.

A lower portion of the mask body cover20can be supported on the second cover coupling portion106. The second cover coupling portion106can protrude in a hook shape from a front lower portion of the mask body10. The first cover coupling portion102can be provided at each of the left and right sides of the mask body10based on the center of the mask body10. The second cover coupling portion106can be defined as a lower cover coupling portion.

A hook hooking portion to which the second cover coupling portion106is coupled can be disposed on each of the left and right sides of the mask body cover20on the rear surface of the mask body cover20.

The mask body10can include a second bracket coupling portion107.

A lower portion of the sealing bracket30can be supported on the second bracket coupling portion107. The second bracket coupling portion107can be provided by opening the mask body10. The second bracket coupling portion107can be disposed in a lower portion of the mask body10. For example, the second bracket coupling portion107can be provided as a through-hole defined in the mask body10.

A second body coupling portion305coupled to the second bracket coupling portion107can be disposed on the sealing bracket30. The second bracket coupling portion107can be provided in plurality, and the second body coupling portion305can also be provided in plurality to correspond to the second bracket coupling portions107. In some implementations, the second bracket coupling portion107can be provided at each of the left and right sides with respect to the center of the mask body10. The second bracket coupling portion107can be defined as a lower bracket coupling portion.

The mask body10can include the above-described sensor mounting portion109.

The sensor mounting portion109can have a rib shape in which a portion of the front surface of the mask body10protrudes forward. In detail, the sensor mounting portion109has a rib shape that is surrounded along an edge of the sensor, and an installation space in which the sensor is installed is defined in the sensor mounting portion109.

A hole through which the installation space and the breathing space communicate with each other is defined in the mask body10corresponding to the inside of the sensor mounting portion109. The sensor disposed in the installation space can include a pressure sensor, and the pressure sensor can sense pressure information of the breathing space through the hole.

The mask body10can include a fan module mounting portion110.

The fan module mounting portion110can include a first fan module mounting portion on which a first fan module16is mounted and a second fan module mounting portion on which a second fan module17is mounted.

The first fan module mounting portion and the second fan module mounting portion can be disposed on the front surface of the mask body10. In detail, the first fan module mounting portion can be disposed at the right side of the mask body10, and the second fan module mounting portion can be disposed at the left side of the mask body10.

The first fan module16and the second fan module17can be detachably coupled to the first fan module mounting portion and the second fan module mounting portion, respectively.

The mask body10can include an air duct120.

The air duct120can be disposed on the front surface of the mask body10.

A passage through which air passes can be provided in the air duct120.

The air duct120can include a first air duct connected to the first fan module mounting portion and a second air duct connected to the second fan module mounting portion.

The first air duct and the second air duct can be respectively disposed on an edge of the first fan module mounting portion and an edge of the second fan module mounting portion, which are adjacent to the center of the front surface of the mask body10so as to be disposed between the first fan module mounting portion and the second fan module mounting portion.

In some examples, the first fan module mounting portion and the second fan module mounting portion can have a shape symmetrical with respect to a vertical plane (or a vertical line) passing through the center of the front surface of the mask body10. Similarly, the first air duct and the second air duct can also have a shape symmetrical with respect to the vertical plane or the vertical line passing through the center of the front surface of the mask body10.

One end of the air duct120communicates with the outlets of the fan modules16and17to allow the external air to be introduced into the air duct120. In addition, the other end of the air duct120communicates with the air outlet129so that the external air introduced into the air duct120is discharged into the breathing space S.

The air duct120can include a control module mounting portion128for mounting the control module18. A portion of the front surface of the air duct120can be provided as a flat portion on which the control module18is capable of being seated, and the flat portion can be defined as the control module mounting portion128. The control module mounting portion128can include a first control module mounting portion128a(seeFIG.9) provided in the front surface of the first air duct and a second control module mounting portion128b(seeFIG.9) provided in the front surface of the second air duct. One control module18can be fixed to the first control module mounting portion128aand the second control module mounting portion128b, or a plurality of control modules can be respectively fixed to the first and second control module mounting portions128aand128b.

The mask body10can include a power module mounting portion130for mounting the power module19.

The power module mounting portion130can be disposed on the front surface of the mask body10. The power module mounting portion130can be provided at one of the left and the right side of the mask body10.

The power module mounting portion130can be disposed at the side of the fan module mounting portion110. Specifically, the power module mounting portion130can be provided between the fan module mounting portion110and a side end of the mask body10. The side end of the mask body10can be defined as an end adjacent to the user's ear when worn. In some examples, a connector hole135can be defined in the side end of the mask body10provided with the power module mounting portion130.

The mask body10can include a battery mounting portion140for mounting a battery.

The battery mounting portion140can be disposed at a center of the front surface of the mask body10. The battery mounting portion140can be provided to protrude forward from the front surface of the mask body10so as to surround the battery.

For example, the battery mounting portion140can include a pair of guide ribs protruding forward from the front surface of the mask body10and a connection rib connecting front ends of the pair of guide ribs to each other. In some examples, the battery can be mounted in a battery accommodation space defined by the pair of guide ribs and the connection rib.

The battery can move downward from an upper side of the battery accommodating space and be inserted into the battery accommodating space and then can move in a reverse direction to be separated. A lower portion of the battery inserted into the battery mounting portion140can be supported by an air discharge portion150to be described later.

The mask body10can include the air discharge portion150.

The air discharge portion150can be disposed in a lower portion of the mask body10. The air discharge portion150can define a flow space through which the air flowing from the first air exhaust hole154toward the second air exhaust hole155passes.

The air discharge portion150can protrude forward from the front surface of the mask body10. In some examples, the air discharge portion150can extend to be rounded in an arch shape or can be bent several times to extend.

When the mask body cover20is coupled to the mask body10, a front end of the air discharge portion150can contact the rear surface of the mask body cover20, and the inner space of the mask body10and the flow space can be distinguished from each other.

The air discharge portion150can define a top surface and both side surfaces of the flow space, and a rear surface of the mask body cover20can define a front surface of the flow space. In some examples, the front surface of the mask body10can define a rear surface of the flow space, and the bottom surface of the mask body10on which the second air exhaust hole155is defined can define a bottom surface of the flow space.

The top surface of the air discharge portion150can support a lower end of the battery. It is connected to lower ends of both sides of the air discharge portion150having the arch shape or tunnel shape can be connected to the bottom surface of the mask body10, and the bottom surface of the mask body10can be defined by the rib extending forward from the lower end of the front surface of the mask body10.

The cover coupling groove101is recessed along the front end of the rib defining the bottom surface of the mask body10, and the lower end of the rear surface of the mask body cover20is coupled to the cover coupling groove101.

The first air exhaust hole154can be defined in the front surface of the mask body10defining the rear surface of the flow space.

The mask body cover20can include a pair of filter mounting portions21and22, as described above.

The filter mounting portions21and22can be provided by recessing the front surface of the mask body cover20to be recessed by a predetermined depth toward the rear surface of the mask body cover20. Filters23and24are accommodated inside the filter mounting portions21and22provided by being recessed, and filter covers25and26can be mounted on edges of the filter mounting portions21and22in the state in which the filters23and24are accommodated.

Air suction ports211and221can be defined in the filter mounting portions21and22. The air suction holes211and221can communicate with fan inlets defined in bottom surfaces of the fan modules16and17, respectively. Each of edges of the air suction ports211and221can have an inclined surface that inclined in a direction in which a diameter gradually decreases from the front surface to the rear surface.

A filter cover mounting groove212,222for fixing each of the filter covers25and26can be defined in a side surface of each of the filter mounting portions21and22. A coupling protrusion inserted into the filter cover mounting groove212,222and222can be disposed on each of the filter covers25and26. InFIG.5, only the coupling protrusion262disposed on the left filter cover26is illustrated, but it is noted that the same coupling protrusion is disposed on the right filter cover25as well.

A sealing material for sealing can be provided between the edges of the rear surfaces of the air suction ports211and221of the filter mounting portions21and22and the fan inlets of the fan modules16and17. The sealing material can surround the air suction ports211and221and edges of the fan inlets of the fan modules16and17to prevent or reduce introduction of the external air.

Alternatively, instead of providing the sealing material, an orifice is disposed on each of the edges of the air suction holes211and221, and the orifice can be in close contact with the edges of the fan suction holes of the fan module16and17to the external air from being introduced. The orifice can be understood as a guide rib extending or protruding backward along the edges of the air suction holes211and221.

The filter mounting portions21and22include a first filter mounting portion21provided at the right side of the mask body cover20and a second filter mounting portion22provided at the left side of the mask body cover20.

The air suction hole defined in the first filter mounting portion21can be defined as a first air suction hole211, and the air suction hole defined in the second filter mounting portion22can be defined as a second air suction hole221.

The filters23and24can include a first filter23accommodated inside the first filter mounting portion21and a second filter24accommodated inside the second filter mounting portion22.

The filter covers25and26can include a first filter cover25mounted on the first filter mounting portion21and a second filter cover26mounted on the second filter mounting portion22. A plurality of first air inlets251can be defined in the first filter cover25to allow the external air to be introduced, and a plurality of second air inlets261can be defined in the second filter cover26to allow the external air to be introduced.

The control module18can be referred to as a first electronic circuit component, and the power module19can be referred to as a second electronic circuit component.

The fan modules16and17can include a fan, a fan motor, and a fan housing accommodating the fan and the fan motor. The fan housing can include a fan inlet through which the air is introduced into the fan, and a fan outlet through which the air forcedly flowing by the fan is discharged.

The fan can include various types of fans. For example, in some implementations, the fan can include a centrifugal fan that can suction air from the front side of the mask body cover20and discharge the air to the side of the mask body10. In some implementations, the fan can include an axial fan or a cross flow fan.

The air introduced through the first air inlet251to pass through the first filter23is suctioned through the first air suction port211. In some examples, the air introduced through the second air inlet261to pass through the second filter24is suctioned through the second air suction port221.

The fan outlet of the first fan module16can communicate with the first air duct to discharge the air to the breathing space, and the fan outlet of the second fan module17can communicate with the second air duct to discharge the air to the breathing space.

The control module18can control an operation of the mask apparatus1. The control module18can be fixed to control module mounting portion128.

The control module18can include a communication module to transmit and receive various types of information. The control module18can include a data storage module to store various types of information.

The control module18can control an operation of each of the fan modules16and17. In detail, the control module18can control the operation of each of the fan modules16and17based on information sensed from the sensor.

The control module18can be electrically connected to the power module19, the fan modules16and17, and the battery so as to be interlocked with each other.

The power module19can receive power from the outside. The power module19can include a charging circuit for charging the battery. The power module19can include the connector192(seeFIG.10) and the manipulation portion195. Thus, the control module18can operate by receiving battery power or external power through the connector192.

The power module19can control supply of power to the mask apparatus1by the manipulation portion195. In detail, the power module19can control supply of power from the battery to the control module18and the fan modules16and17.

The seal40can be coupled to the rear surface of the mask body10by the sealing bracket30to be in close contact with the user's face.

The rear surface of the mask body10can be to be spaced apart from the user's face by the seal40.

The sealing bracket30can be provided in a ring shape forming a closed loop.

The seal40can be detachably coupled to the sealing bracket30.

In some examples, the sealing bracket30is coupled to be detachable from the mask body10to separate the sealing bracket30from the mask body10. With this structure, only the sealing bracket30is separated, or an assembly of the seal40and the sealing bracket30is separated from the mask body10to clean only the sealing bracket30or clean both the sealing bracket30and the seal40.

After the seal40is coupled to the sealing bracket30, when the sealing bracket30is coupled to the mask body10, the seal40is stably fixed to the mask body10.

The sealing bracket30can include a sealing insertion portion301to which the seal40is coupled. The sealing insertion portion301can have a flat band shape and thus can be inserted into a groove defined in an inner edge of the seal40. The sealing insertion portion301can be understood as a body of the sealing bracket30. In detail, it can be understood that an inner edge of the seal40is provided in the form of seal lips split into two parts, and the sealing insertion portion301is inserted between the seal lips so that the seal40and the sealing bracket30are coupled to each other.

The sealing insertion portion301can be provided in a shape of which a thickness decreases from the inner edge to the outer edge thereof.

The sealing bracket30can include the fixing guide302. The fixing guide302can be disposed along the inner edge of the sealing insertion portion301. The fixing guide302can function to set a limit in which the sealing insertion portion301is inserted into a groove defined in the inner edge of the seal40. That is, the fixing position of the inner edge of the seal40is determined by the fixing guide302.

When the inner edge of the seal40is in contact with the fixing guide302, it can be seen that the sealing insertion portion301is completely inserted into the seal lips of the seal40. The fixing guide302can be designed to be larger than a thickness of the inner edge of the sealing insertion portion301.

A portion constituted by the sealing insertion portion301and the fixing guide302can be defined as a bracket body.

The sealing bracket30can include a first body coupling portion304coupled to the first bracket coupling portion103. The first body coupling portion304can be provided on an upper portion of the sealing bracket30. The first body coupling portion304can be provided at a position and in number corresponding to the first bracket coupling portion103. The first body coupling portion304can be referred to as an upper body coupling portion. For example, the first body coupling portion304can be provided in a hook-fixed shape to which the first bracket coupling portion103having the form of a hook is hooked and fixed. The sealing bracket30can include a second body coupling portion305coupled to the second bracket coupling portion107. The second body coupling portion305can be provided under the sealing bracket30. The second body coupling portion305can be provided at a position and in number corresponding to the second bracket coupling portion107. The second body coupling portion305can be referred to as a lower body coupling portion. For example, the second body coupling portion305can be provided in the form of a hook protruding forward from the sealing insertion portion301.

The sealing bracket30can include a bracket insertion portion306extending from an inner edge of the bracket body and coupled to the mask body10. The bracket insertion portion306is inserted into a cutoff portion127(seeFIG.10) defined in the mask body10to shield a portion of an edge of the cutoff portion127.

The cutoff portion127can be understood as an opening communicating with the air duct120so that the air passes therethrough. The bracket insertion portion306can be disposed on one edge of the cutoff portion127, specifically, an outer edge.

The air outlet129described above can be understood as the remaining portion of the cutoff portion127that is not covered by the bracket insertion portion306in a state in which the bracket insertion portion306is inserted into one side of the cutoff portion127.

When the bracket insertion portion306is inserted into or coupled to the one side of the cutoff portion127to shield the one side of the cutoff portion127, the air discharged from the fan modules16and17can pass between the air duct120and the bracket insertion portion306to flow to the air outlet129.

The bracket insertion portion306can serve as a function of fixing the sealing bracket30to the mask body10while defining one surface of the air duct120. In detail, an upper portion of the sealing bracket30can be fixed to the upper portion of the mask body10by the first body coupling portion304, a lower portion of the sealing bracket30can be fixed to the lower portion of the mask body10by the second body coupling portion305, and an intermediate portion of the sealing bracket30can be fixed to an intermediate portion of the mask body10by the bracket insertion portion306.

The seal40can be made of a material having elasticity. The seal40can be in close contact with the user's face and deformed to correspond to an outline of the user's face. The seal40can be provided in a ring shape forming a closed loop. The seal40can be provided to cover the user's nose and mouth.

The seal40includes a coupling portion400acoupled to the mask body10, a side surface portion400cextending from the coupling portion400atoward the user's face, and a contact portion400bthat is bent from an end of the side surface portion400cto extend toward the coupling portion400a(seeFIG.11).

The contact portion400bcan be a portion that is in close contact with the user's face, and the side surface portion400cand the contact portion400bcan be angled at an angle of about 90 degrees or less to define a space between the side surface portion400cand the contact portion400b.

A first opening can be defined inside the coupling portion400a, and a second opening can be defined inside the contact portion400b.

As illustrated inFIG.3, the second opening can include a main opening in which the front of the user's nose and mouth are disposed and a sub opening extending from an upper end of the main opening and disposed on the user's nose.

In some examples, a lower portion of the main opening, that is, a portion that is in close contact with the front of the user's jaw can be designed closer to the mask body10than a portion that is in close contact with the front of the user's cheek.

In some examples, a plurality of ventilation holes are defined in the contact portion400bto minimize a phenomenon in which moisture is generated on the user's cheek. The plurality of ventilation holes can have different sizes, and as an example, a diameter of the ventilation hole can gradually increase from an inner edge to an outer edge of the contact portion400b.

The air outlet129and the air exhaust holes154and155can be provided inside the first opening, and the user's nose and mouth can be disposed inside the second opening.

The seal40is disposed between the user's face and the mask body10, and the breathing space S is defined by the coupling portion400a, the contact portion400b, and the inner side of the side surface portion400cof the seal40.

The seal40can include a bracket insertion groove401. The bracket insertion groove401can be configured so that the sealing insertion portion301of the sealing bracket30is inserted therein. The bracket insertion groove401can be defined in the coupling portion400aof the seal40. The bracket insertion groove401can be defined in an inner edge of the coupling portion400a. The sealing insertion portion301of the sealing bracket30can be inserted into the bracket insertion groove401defined in the coupling portion400aso that the seal40and the sealing bracket30are coupled to each other.

The seal40includes seating grooves404and406, on which the first body coupling portion304and the bracket insertion portion306are respectively seated, and a through-hole405through which the second body coupling portion305passes. The seating grooves404and406and the through-hole405can be defined in the coupling portion400a. The seating grooves404and406can include a first seating groove404that is defined in number and position corresponding to the number and position of the first body coupling portion304and a second seating groove406that is defined in number and position corresponding to the bracket insertion portion306. The through-hole405can be defined in number and at a position corresponding to the second body coupling portion305.

When the first body coupling portion304, the second body coupling portion305, and the bracket insertion portion306are inserted into the seating grooves404and406and the through-hole405, the seal40and the sealing bracket30can be coupled to be in close contact with each other.FIGS.6and7are views illustrating a flow of air when the mask apparatus operates.

Referring toFIGS.6and7, the mask apparatus1can suction the external air through the air inlets251and261provided in the filter covers25and26. The flow direction of the external air suctioned into the mask apparatus1is indicated by a reference symbol A.

Since the air inlets251and261are provided in plurality to suction the air in various directions, an inflow rate of the external air increases.

For example, the air inlets251and261can include air inlets251aand261afor suctioning air flowing at upper sides of the filter covers25and26, air inlets251band261bfor suctioning air flowing at a front side of the filter covers25and26, and air inlets251cand261cfor suctioning air flowing at a lower side of the filter covers25and26. The side air inlets251band261bcan be provided at one or both sides of the left and right sides of the filter covers25and26.

Since the filter covers25and26in which the air inlets251and261are provided are respectively disposed at left and right sides of the front surface of the mask apparatus1, the external air can be smoothly suctioned from the left and right sides of the front surface of the mask apparatus1.

The external air introduced through the air inlets251and261can be filtered by passing through the filters23and24disposed inside the filter mounting portions21and22. The filters23and24can be replaced when the filter covers25and26are separated from the mask apparatus1.

The air passing through the filters23and24can be introduced into the fan inlets of the fan modules16and17through the air suction holes211and221. In the filter mounting portions21and22, the air suction holes211and221are defined, and the fan modules16and17are assembled in the state of being in close contact with each other. Thus, the air passing through the filter may not leak to the outside, and the external air may not be introduced between the filter mounting portions21and22and the fan modules16and17.

The air discharged through the fan outlets of the fan modules16and17can pass through the air duct120to flow into the breathing space S through the air outlet129. A flow direction of the air introduced into the breathing space S through the air outlet129is indicated by a reference symbol B.

The breathing space can be defined by the mask body10and the seal40. When the mask body10is in close contact with the user's face, the seal40can be in close contact with the mask body10and the user's face to form an independent breathing space that is separated from the external space.

The user inhales after suctioning the filtered air supplied through the air outlet129can be exhausted to the external space through the air exhaust holes154and155.

As described above, the air exhaust holes154and155include a first air exhaust hole154communicating with the breathing space and a second air exhaust hole155communicating with the external space, and the first air exhaust hole154and the second air exhaust hole155can communicate with each other by the flow space defined by the air discharge portion150. The air exhaled by the user can be guided into the flow space through the first air exhaust hole154. A flow direction of the air flowing into the flow space through the first air exhaust hole154is indicated by a reference symbol C.

The air guided into the flow space through the first air exhaust hole154can be discharged to the external space through the second air exhaust hole155. A flow direction of the air discharged into the external space through the second air exhaust hole155is indicated by a reference symbol D.

FIG.8is a front exploded view of the mask apparatus,FIG.9is a front perspective view of the mask body, andFIG.10is a rear exploded view.

Referring toFIGS.8to10, an outer appearance of the mask apparatus1can be defined by coupling the mask body10to the mask body cover20. An inner space, in which fan modules16and17, at least a portion or the whole of a power module19, a control module18, and a battery are accommodated, can be defined between the mask body10and the mask body cover20.

At least a portion or the whole of the fan modules16and17, the power module19, the control module18, and the battery accommodated in the inner space can be fixed to the front surface of the mask body10. Alternatively, the fan modules16and17can be fixed to the front surface of the mask body10, and the power module19, the control module18, and the battery can be fixed to the rear surface of the mask body cover20.

The seal40can be fixed to the rear surface of the mask body10by the sealing bracket30. A breathing space S is defined inside the seal40, and when the seal40is in close contact with the user's face, the mouth and nose of the user are accommodated in the breathing space S.

The breathing space S communicates with the air outlet129and the air exhaust holes154and155of the mask body10. The air introduced into the breathing space S through the air outlet129can be inhaled by the user, and the air collected in the breathing space S when the user exhales can be discharged to the external space through the air exhaust holes154and155.

The seal40can be deformed between the mask body10and the user's face to be in close contact between the mask body10and the user's face.

The mask body10can include a support rib104. The support rib104allows the mask body10and the mask body cover20to be coupled in a state of being spaced apart from each other. In some implementations, the support rib104can further include a fixing hook104afor supporting one side of the control module18. In detail, the fixing hook104acan be hung on an upper end of the control module18so that an upper portion of the control module18is supported by the support rib104.

The mask body10can include a fan module mounting portion110.

The fan module mounting portion110can include a first fixing rib112and a second fixing rib114. The first fixing rib112and the second fixing rib114can support top and bottom surfaces of the fan modules16and17, respectively. The first fixing rib112and the second fixing rib114can protrude forward from the front surface of the mask body10, and the fan modules16and17can be accommodated between the first fixing rib112and the second fixing rib114.

The air duct120can be disposed at one end of each of the first fixing rib112and the second fixing rib114, and a coupling portion for fixing a portion of each of the fan modules16and17can be disposed at the other end of each of the first fixing rib112and the second fixing rib114.

The fan module mounting portion110can include a cable fixing rib113. The cable fixing rib113can be provided on a top surface of the first fixing rib112and the front surface of the mask body10. The cable fixing rib113can be provided to fix a cable extending from the control module18toward the fan modules16and17, the power module19, and the like.

The cable fixing rib113can include a first cable fixing rib provided on a top surface of the first fixing rib112or a bottom surface of the second fixing rib114and a second cable fixing rib provided on the front surface of the mask body10.

The first cable fixing rib and the second cable fixing rib are spaced apart from each other in the widthwise direction of the mask body10. In some examples, the first and second cable fixing ribs can protrude in a direction crossing each other and can extend in the width direction of the mask body10. A portion of the cable can be fixed by the first cable fixing rib, and a remaining portion of the cable can be fixed by the second cable fixing rib.

The fan module mounting portion110can include fan module coupling portions116and118. The fan module coupling portions116and118can be provided in plurality. The fan module coupling portions116and118can be portions for supporting the edges of the fan modules16and17mounted on the fan module mounting portion110, and thus, a coupling member passing through the edges of the fan modules16and17can be inserted into the fan module coupling portions116and118.

The fan module coupling portions116and118can protrude from the front surface of the mask body10. A coupling hole into which the coupling member is inserted can be defined in each of the fan module coupling portions116and118. Alternatively, the fan module coupling portions116and118can be provided in a pair of coupling ribs facing each other, and the coupling member can be inserted into a space defined between the pair of coupling ribs.

The fan module coupling portions116and118can include a first side coupling portion116and a second side coupling portion118. The first side coupling portion116and the second side coupling portion118can be provided to be spaced apart from each other in a height direction (upward and downward direction) perpendicular to the width direction of the mask body10to support upper and lower sides of the side ends of the fan modules16and17.

An inclined surface can be provided on each of the fan module coupling portions116and118. The inclined surface can be provided to be inclined upward from an outer edge (an edge close to the side end of the mask body) to an inner edge (an edge close to the center of the mask body) of the fan module mounting portion110. Thus, the fan modules16and17can be slid from the side end of the mask body10toward a center along the inclined surface so as to be in close contact with a suction end of the air duct120.

The air duct120can be established by a front surface portion120aprovided on the front surface of the mask body10, a rear surface portion120bfacing the front surface portion and provided on the rear surface of the mask body10, and top and bottom surface portions120cand120dthat connect the front surface portion120ato the rear surface portion120b.

The top surface portion120cand the bottom surface portion120dcan extend in a direction crossing the front surface portion120aat the upper and lower ends of the front surface portion120aand be defined as a first connection portion120cand a second connection portion120d, which are respectively disposed at upper and lower sides. In some examples, the rear surface portion120bcan include an opened surface or the cutoff portion127.

The front surface portion120ais again constituted by a curved portion1201and a flat portion1202, and the flat portion1202can be defined as the control module mounting portion128as described above.

Since the side surface portion of the air duct120is opened, external air can be introduced through the opened side surface portion. In some examples, since the discharge ports of the fan modules16and17are in contact with the opened side surface, the opened side surface can be defined as the fan module insertion hole123(seeFIG.14). Alternatively, the opened side surface portion can be defined as an inlet of an air passage provided inside the air duct120.

A portion of the rear surface portion120bcan be shielded by the bracket insertion portion306, and the rest of the rear surface portion120bexcept for the portion shielded by the bracket insertion portion306can be defined as an air outlet129.

In detail, the side surface portion of the air duct120, that is, a front end of the fan module insertion hole123can be connected to one side end of the front surface portion120a, and a rear end of the fan module insertion hole123can be connected to one side end of the rear surface portion120b.

In some examples, the other side end of the front surface portion120acan be connected to the other side end of the rear surface portion120bso that the air duct120has a shape having one side portion.

The front surface portion120acan be a portion of the mask body10that protrudes forward.

An uneven portion122can be disposed on the rear end of the flat portion1202.

The uneven portion122can be a plurality of protrusions or ribs that protrude from the rear surface of the flat portion1202to extend vertically and are spaced apart from each other in a width direction (lateral direction) of the mask body10.

The air discharged from the fan modules16and17can pass through the air duct120and be introduced into the breathing space. In detail, the air discharged from the fan modules16and17can flow in a laminar flow manner between the curved portion1201and the bracket insertion portion306. The air passing between the curved portion1201and the bracket insertion portion306can flow in the laminar flow manner due to a flow velocity of air forcedly flowing by the fan modules16and17.

The air flowing in a laminar flow manner can be guided by the curved portion1201to flow toward the uneven portion122of the flat portion1202. The air flowing in the laminar flow manner can be converted into a turbulent flow while passing through the uneven portion122of the flat portion1202.

The air converted from the laminar flow to the turbulent flow by the uneven portion122can pass through the air outlet129and be discharged into the breathing space. When the air flow is converted from the laminar flow into the turbulent flow by the uneven portion122, noise can be reduced while the flow rate of the air supplied to the breathing space S through the air outlet129increases. In some examples, the air converted from the laminar flow to the turbulent flow can be efficiently supplied to the breathing space because a diffusion effect is very strong.

The air duct120can include a division portion124. The division portion124can protrude from a rear surface of the front surface portion120ato extend in a flow direction of the suctioned air. In some examples, a plurality of division portions124can be spaced apart from each other in the vertical direction of the front surface portion120a. As a result, the air passing through the air duct120can be divided into a plurality of passages by the plurality of division portions124and then be introduced into the breathing space.

The division portion124can extend up to an inner side end of the front surface portion120aat a point that is spaced a predetermined distance from an outer side end (an edge in which the fan module insertion hole is defined) of the front surface portion120ain the flow direction of the air.

The division portion124can include a bracket coupling groove125. The bracket insertion portion306of the sealing bracket30can be disposed in the bracket coupling groove125.

The bracket coupling groove125can be defined by recessing or stepping an end of the division portion124. When the bracket insertion portion306is disposed in the bracket coupling groove125, an edge of the bracket insertion portion306can be supported by the division portion124. The cutoff portion127can be divided into a second space1272into which the bracket insertion portion306is inserted and a first space1271through which air is discharged by the bracket coupling groove125.

The air duct120can include a fan module support126. The fan module support126is provided to be recessed or stepped in a central direction of the air duct120from the top surface portion120cand the bottom surface portion120dof the air duct120, respectively (seeFIG.9). An outer end of the fan module support126can include a protrusion that limits the fan modules16and17from being excessively inserted into the inside of the air duct120through the fan module insertion hole123. In some examples, an inner end of the fan module support126is provided to be inclined as illustrated in the drawings to function as a support protrusion that supports the bracket insertion portion306. Thus, the fan module support126can be defined as a bracket support.

The top surface portion120cand the bottom surface portion120dcan be connected to the first fixing rib112and the second fixing rib114, respectively.

The mask body10can include a cutoff portion127. The cutoff portion127can be defined by cutting a portion of the mask body10. The cutoff portion127can be understood as an opening defined by cutting a portion of the rear surface of the mask body10to connect the air duct120provided to the mask body10to the breathing space S. Although referred to as a cutoff portion In some implementations, it can be defined as an opening or a hole, and the cutoff portion can be understood as an outlet of the air duct120.

As illustrated inFIG.9, the air duct120can include a first air duct120A and a second air duct120B. As illustrated inFIG.11, the cutoff portion127can include a first cutoff portion127acommunicating with the first air duct120A and a second cutoff portion127bcommunicating with the second air duct120B. The first cutoff portion127acan be provided at either side of the left or right from the center of the mask body10, and the second cutoff portion127bcan be provided at the other of the left and right from the center of the mask body10.

In more detail, the first air duct120A and the first cutoff portion127acan be disposed between the center of the mask body10and the first fan module16, and the second air duct120B and the second cutoff portion127bcan be disposed between the center of the mask body and the second fan module17.

The cutoff portion127can include a first space1271corresponding to the air outlet129and a second space1272into which the bracket insertion portion306of the sealing bracket30is shielded. The first space1271can be defined as a discharge space through which the air flows. The second space1272can be defined as a mounting space into which the bracket insertion portion306is disposed.

Since the bracket insertion portion306is inserted into the second space, an effect of extending the air passage can be obtained in addition to the effect of stably supporting the central portion of the seal40.

In detail, when the bracket insertion portion306is placed in the second space1272, and the second space1272is shielded, an outlet of the air duct120can decrease, but the effect of extending the air passage can be obtained. Accordingly, most of the inhaled air is concentrated to the user's nose and mouth, and an amount of air distributed toward the user's cheeks can be minimized.

In some implementations, the rear surface portion120bcan be divided into the first space1271and the second space1272. When the bracket insertion portion306is not inserted, the second space1272together with the first space1271can be also defined as a portion of the air outlet129. That is, it can be understood that the entire rear portion120bcan function as the air outlet129.

The air discharge portion150protruding from a lower portion of the front surface of the mask body10can define a flow space for discharging air to an external space.

The air discharge portion150can include an upper side surface (or upper surface)150a, a lower side surface (or lower surface)150c, and both side surfaces150b. The upper side surface150a, the lower side surface150c, and both side surfaces150bcan protrude forward from the front surface of the mask body10. The upper side surface150adefines a top surface of a flow space, the lower side surface150cdefines a bottom surface of the flow space, and both side surfaces150bdefine both side surfaces of the flow space.

FIG.11is a rear view of the mask apparatus,FIG.12is a graph illustrating a change in flow rate with respect to a change in number of rotation, andFIG.13is a graph illustrating a change in noise with respect to a change in flow rate.

Referring toFIGS.11to13, the air duct120can increase in cross-sectional area from the fan module insertion hole123toward the air outlet129.

The fan module insertion hole123can be defined as an inlet side or duct inlet of the air duct120, and the air outlet129can be defined as an outlet side or duct outlet of the air duct120. The air duct120can be provided in a shape in which a flow cross-sectional area increases from the inlet side toward the outlet side.

In some implementations, the cross-sectional area of the outlet can be greater than the cross-sectional area of the inlet of the air duct120. In some examples, a length of the inner edge can be greater than a length of the outer edge of the outlet. In other words, the length of the inner side end that is close to the center of the mask apparatus can be greater than the length of the outer side end that is close to the side end of the mask apparatus.

For example, the cutoff portion127can include an inner side end that is disposed adjacent to a center axis of the mask body and extend along the center axis, and an outer side end that is disposed away from the center axis relative to the inner side end and extends along the center axis. An extension length (W2) of the inner side end along the center axis can be greater than an extension length (W1) of the outer side end along the center axis. The center axis can extend vertically through the sensor mounting portion109and the air discharge portion150.

The flow cross-sectional area can be defined by a height indicating a distance between the front surface portion120aand the rear surface portion120b, and a width indicating a distance between the top surface portion120cand the bottom surface portion120d. In some implementations, the air duct120can be configured in that the width which is a distance between the top surface portion120cand the bottom surface portion120dincreases.

The flow cross-sectional area at the outlet side can be greater than the flow cross-sectional area at the inlet side by the width that increases from the inlet side to the outlet side of the air duct120. The width at the inlet side of the air duct120is defined as a first width W1, and the width at the outlet side is defined as a second width W2. The second width W2can be greater than the first width W2. The increase in flow cross-sectional area from the inlet side to the outlet side of the air duct120can be referred to as a diffuser structure or a diffuser pipe structure.

According to the structure, since a flow speed of air at the outlet side is lower than a flow velocity of air at the inlet side, the air can be supplied to the user in a state in which a discharge pressure of the air discharged from the fan modules16and17is reduced. That is, since a pressure in the breathing space is reduced, there is an advantage that the user's breathing is smooth.

A first virtual line l1extending in parallel to a flow direction of air discharged from the inlet side of the air duct120and a second virtual line l2extending in parallel to the top surface portion120cor the bottom surface portion120d, which extends from the inlet side to the outlet side of the air duct120can be provided. The second virtual line can have a predetermined angle θ with respect to the first virtual line. In some implementations, the predetermined angle can range of about 20 degrees to about 40 degrees. An angle defined by the first virtual line and the second virtual line can be referred to as a diffuser angle.

The air passing through the air duct120can flow from the inlet side having a first width W1to the outlet side having a second width W2, a flow speed of air can be effectively reduced by the increasing flow cross-sectional area, a static pressure can increase to allow the air discharged from the air outlet129to be quickly diffused into the breathing space.

In some implementations, each of the top surface portion120cand the bottom surface portion120dare described as being provided as a flat surface, but each of the top surface portion120cand the bottom surface portion120dcan be provided as a curved surface.

In some implementations, since the air is uniformly diffused and supplied to the breathing space, breathing discomfort caused by excessive supply of the air can be eliminated.

When explaining the increase in flow cross-sectional area according to another aspect, the air outlet129can have a shape having a length (or width) that gradually increases from the outer edge that is close to the side end of the mask body10toward the inner edge that is close to the center of the mask body10. That is, it can be described that the air outlet129has a trapezoidal shape.

FIG.12is a graph of results obtained by measuring a flow rate of air flowing from the inlet to the outlet of the air duct120by changing the number of rotation of the fan after adjusting a diffuser angle of the air duct120.

Examples of the angle of the diffuser include an n0 value angle, an n1 value angle obtained by adding an angle from the ns value angle, and an n2 value angle obtained by adding an angle from the n1 value angle. The n value angle is 0 degree, the n1 value angle is about 30 degrees, and the n2 value angle is about 40 degrees.

When the angle of the diffuser is 0 degree, the diffuser structure may not be applied to the air duct120. As the angle of the diffuser increases, the flow rate of the air passing through the air duct120increases compared to a structure in which the diffuser angle is 0 at the same rotational number. In some examples, the flow rate increases when the diffuser angle is about 30 degrees compared to a case in which the diffuser angle is about 40 degrees at the same rotational speed.

When the diffuser angle is close to 0, a difference between the flow cross-sectional area of the air duct120between the inlet side and the outlet side is not large, and thus an effect obtained by the diffuser or the diffuser pipe structure can be insufficient. As the diffuser angle increases from 0, the air diffusion effect obtained by the diffuser or diffuser pipe structure can also increase.

That is, it is seen that the flow rate of the air passing through the air duct120increases until the diffuser angle reaches a specific angle under the same rotational number, but the flow rate of the air passing through the air duct120decreases rather above the specific angle under the same rotational number.

This is because air introduced from the inlet side of the air duct120is far apart from the top surface portion120cand the bottom surface portion120dof the air duct at the specific diffuser angle, and thus, it is believed that this is because an interference between the air and the air duct is minimized.

FIG.13is a graph of results obtained by measuring noise that is changed according to a change in flow rate after the diffuser angle of the air duct120is adjusted.

As the flow rate increases, the noise can also increase. As the flow rate increases, the noise can also increase. As the flow rate increases, an amount of air passing through the air duct120increases. Thus, as the amount of air flowing increases, the air flow noise can increase.

As the diffuser angle increases, the noise generated at the same flow rate decreases. As the diffuser angle increases, the flow cross-sectional area of the outlet side of the air duct120increases rather than the inlet side, and thus, the discharge pressure of the air can be changed according to the increase in flow cross-sectional area to reduce the discharge noise.

The noise is further reduced when the diffuser angle is about 30 degrees and about 40 degrees compared to a case in which the diffuser angle is 0 degree. However, the noise detected at the diffuser angle of about 40 degrees at the same flow rate is slightly reduced than that detected at the diffuser angle of about 30 degrees. When the diffuser angle is greater than or equal to a predetermined angle, a vortex or swirling wind can be generated at the outlet side of the air duct120, and the noise reduction effect can be reduced by the vortex or swirling wind. If the noise reduction effect is reduced, the generated flow noise can increase again.

That is, the noise reduction effect can also increase so a predetermined diffuser angle increases, but the reduction effect can be reduced over the predetermined angle, compared to the increasing flow rate. Furthermore, as the diffuser angle approaches 0, the flow rate of flowing air can increase, but the generated flow noise can also increase.

Therefore, In some implementations, the diffuser angle is proposed to be about 20 degrees to 40 degrees.

FIG.14is a transverse cross-sectional view taken along14-14ofFIG.9,FIG.15is a graph illustrating a relationship between a flow rate and noise according to a difference in shape of the air duct, andFIG.16is a graph illustrating a relationship between a rotation number and a flow rate according to a difference in shape of the air duct.

Referring toFIGS.14to16, air flowing from an inlet side to an outlet side of an air duct120according to another implementation can pass between a front surface portion120aand a rear surface portion120bof the air duct120.

An uneven portion122can be provided on a rear surface of a flat portion1202of the front surface portion120aof the air duct120.

The front surface portion120aof the air duct120and a bracket insertion portion306covering the rear surface portion120bcan be connected to a top surface portion120cand a bottom surface portion120dto provide an air passage through which air passes.

The air passing through the air duct120can be converted in air flow direction toward an air outlet129by the curved portion1201and also be converted in air flow characteristic by the uneven portion122. The curved portion1201can be provided at a gentle angle so that the change in flow speed is small. The curved portion1201can be provided in a shape that is rounded with a predetermined curvature. An angle defined by a virtual line (l3or l4) extending in a direction perpendicular to a surface passing through an inlet of the air duct120and a straight line connecting a start point and an end point of the curved portion1201is approximately 30 degrees.

Air passing through the curved portion1201can be guided to the uneven portion122. The air passing through the curved portion1201can be changed from a laminar flow to a turbulent flow while passing through the uneven portion122.

Since the air flow is converted from the laminar flow to the turbulent flow, discharge noise of air discharged from the air outlet129can be reduced, and the flow rate of air passing through the outlet side of the air duct120can be reduced by the reduced discharge pressure and the increasing flow cross-sectional area by the turbulent flow of air can increase.

Referring toFIG.15, as a result of comparing the flow rate of air flowing along the air duct having the curved portion and the air duct having only a linear portion, it can be seen that the noise generated by the air flowing along an arc-shaped passage having the curved portion is less than noise generated by the air flowing the linear passage under the same air flow rate.

When the air having a low flow rate passes through the air duct, the noise generated in the linear passage is less than the noise generated in the arc-shaped passage, but as the flow rate increased, the increase of the noise generated in the arc-shaped passage is less than an increase of the noise generated in the linear passage.

Referring toFIG.16, it can be seen that the flow rate of air flowing along the passage having the curved portion1201is greater than the flow rate of air flowing along the passage having only the linear portion under the condition in which the rotation speed of the fan is set equally.

In some examples, as the number of rotation of the fan increases, an increase in flow rate of air flowing along the passage having the curved portion1201is greater than the increase in flow rate of air flowing along the passage having only the linear portion.

In some implementations, the curved portion1201can be provided on the front surface portion120aof the air duct120and further include an uneven portion122. In some examples, the uneven portion122may not be provided in the curved portion1201.