1 FACE WASHING DEVICE HAVING COSMETIC BRUSH MADE FROM NYLON BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a face washing machine having a nylon 5 makeup brush, and more particularly, to a face washing machine having a nylon makeup brush in which a bristle base is divided into two sides such that nylon bristles are inserted into an inner side and an outer side respectively, wherein the bristles have rounded ends and the bristles inserted into the inner side rotate, resulting in soft and stable face washing. 10 2. Description of the Related Art In general, regardless of age or gender, people have a desire for the beauty of body. Since it is required a systemic and clean skin care for this beauty of body, particularly, for the beauty of skin, various skin care machines for the skin beauty 15 have been developed. These skin care machines have widely been developed in various types suitable for nature of body parts to which the skin care machines are applied. Especially, skin case is carried out using fundamental cosmetics as a method of caring face skin above all body parts and functional cosmetics are used 20 for the skin care nowadays. Up to now, various devices are proposed to wash face such as device simply rotating a washing brush, a device making vibration, and a face washing machine rotating forward and reversely to wash face using a brushless electric motor. The face washing machine using a brushless electric motor is disclosed in 25 Korean Patent No 10-1257256 and includes a case 100; an operating unit 200 installed out of the case to command forward and reversely switching by a preset angle; a power supply 300 installed at an inner end of the case; a brushless motor 400 installed in the case to rotate forward and reversely by a preset angle when an electric power is supplied from the power supply; a controller 500 outputting an 30 electric signal to control the forward and reverse rotation of the brushless motor 400 2 according to the switching signal from the operating unit; and a face-washing brush 600 fitted around a shaft of the brushless DC (BLDC) motor 400 to rotate forward and reversely when the BLDC motor is driven; wherein the controller 500 includes: a rectifying unit 510 having a rectifier 511 and a smoothing capacitor 512 to rectify and 35 smoothen an AC power into a DC power; an inverter 530 converting the DC power supplied from the rectifying unit 510 into a three-phase (U, V, and W) AC power in the form of pulses with any variable frequency and having six switching devices Q1 to Q6 and six diodes; a terminal voltage detector 560 detecting terminal voltages of the respective phases U, V, and W from the three-phase AC power supplied to the 40 BLDC motor 400; a control circuit 570 detecting a zero crossing point (ZCP) of a counter electromotive force based on the terminal voltages of the respective phases U, V, and W that are detected by the terminal voltage detector 560 to acquire position information of a rotor and controlling patterns of a PWM signal fed to the inverter 530 to rotate the rotor of the motor forward and reversely by a preset angle; 45 and a PWM signal generator 580 generating the patterns of the PWM signal based on the output from the control circuit 570 to feed the patterns to the inverter 530. The outer appearance thereof, as illustrated in FIGS. 1 and 2, is configured such that the face-washing brush is coupled to the shaft of the BLDC motor so that the face-washing brush rotates forward and reversely when the BLDC motor rotates 50 forward and reversely and then the face washing is enabled. However, in the configurations, foreign matters are spattered out when the foreign matters remaining on face are washed out during the rotation of the face washing brush. In other words, the face-washing brush rotates and rubs the face and at this 55 time, liquid content flows and is spattered in all directions due to the rotation of the face-washing brush when liquid content remains resulting in sanitary matter. Moreover, according to the existing face-washing machine using a BLDC motor, since the BLDC motor rotates forward and reversely simply, a high torque cannot be applied to face. 60 3 SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a face washing machine having nylon makeup brush designed such that a 65 separated supporting brush is installed in an not-rotated area when a face-washing brush is installed, that the face-washing brush is installed therein and is connected to an electric motor so that liquid content is filtered by supporting brush during rotation of the face-washing brush, and made of nylon such that tips of the face-washing brush are rounded to touch face of a user softly. 70 Moreover, the present invention provides a face washing machine in which a high torque is applied to a face-washing brush using a spring so that easy face washing can be achieved. In order to achieve the above object, the present invention provides a face washing apparatus including a face washing apparatus case (100) having a rotating 75 unit rotating by receiving externally provided electricity or battery electricity or a power from a secondary battery; and a face washing brush (600) coupled to the face washing apparatus case so as to rotate, wherein the face washing brush (600) includes: a first brush bristle set (610) formed of nylon and mounted on an output terminal of the rotating unit to reversibly rotate according to reversible rotation of the 80 rotating unit; and a plurality of second brush bristle sets (620) formed of nylon, which are mounted on an outer side of a front surface of the face washing apparatus case, arranged in parallel to the first brush bristle sets at a height equal to a height of the first brush bristle set, simultaneously spaced apart from the first brush bristle set by a predetermined distance, and fixedly surrounding a periphery of the first brush bristle 85 set to prevent foreign substances from being dispersed when the first brush bristle set is rotated, wherein each of the first brush bristles (611) constituting the first brush bristle set (610) has a distal end polished to be rounded in an arc shape; and wherein the rotating unit includes: an operating unit (200) mounted on an outer side of the case to instruct power on/off and reversible rotation switching in a unit of a 90 predetermined angle; a power supply unit (300) mounted on an inner one end of the 4 case; a brushless electric motor (400) mounted in the case to operate by receiving power from the power supply unit according to a switching signal of the operating unit and to reversibly rotate in the unit of the predetermine angle; a control unit (500) to output an electric signal to control the reversible rotation of the brushless electric 95 motor at the predetermined angle according to the switching signal of the operating unit; a holder (700) coupled to a shaft (410) of the brushless electric motor (400) and including vertical and horizontal panels bent in an L shape to reversibly rotate according to the reversible rotation of the brushless electric motor; a spring (800) coupled to one side of the horizontal panel of the holder and having an opposite side 00 coupled to a support unit to move about the support unit while being supported by the support unit as the holder moves up and down in a vertical direction, the spring providing elasticity in order to generate torque to return the holder to an original position; the support unit (900) to support the opposite side of the spring to induce the torque; and a ballast (1000) mounted at an upper portion of the holder to 05 maintain a balance of the holder such that reversible rotation of the holder is stably induced. Further, each brush bristle (621) constituting the second brush bristle set (610) has a distal end polished to be rounded in an arc shape or is formed in a straight line. 10 In addition, the brush bristles (611 and 621) constituting the first brush bristle set (610) and the second brush bristle set (620) have thicknesses of 63±1 04m. Further, the brush bristles (611 and 621) constituting the first brush bristle set (610) and the second brush bristle set (620) have lengths of 9.0±1.0 mm. In addition, 90,000 to 120,000 brush bristles (611 and 621) are implanted to 15 constitute the first brush bristle set (610) and the second brush bristle set (620). Further, the first brush bristle set (610) is formed in a first color and the second brush bristle set (620) is formed in a second color different from the first color. As described above, the face washing machine according to the present invention is designed such that a separated supporting brush is installed in an not 20 rotated area when a face-washing brush is installed, that the face-washing brush is 5 installed therein and is connected to an electric motor so that liquid content is filtered by supporting brush during rotation of the face-washing brush, and is made of nylon such that tips of the face-washing brush are rounded to touch face of a user softly. Moreover, a high torque is applied to a face-washing brush using a spring so 25 that easy face washing can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view illustrating an entire appearance of a face washing machine according to an embodiment of the present invention; 30 FIG. 2 is a vertical sectional view taken along the line A-A of FIG. 1; FIG. 3 is a perspective view illustrating main parts such as an electric motor, a spring, and a support of a face washing machine according to an embodiment of the present invention; FIG. 4 is an exploded perspective view of FIG. 3; 35 FIG. 5 is a view illustrating operation of a spring employed in a face washing machine according to an embodiment of the present invention; and FIG. 6 is a sectional view illustrating an example of bristle employed in a face washing machine according to an embodiment of the present invention. 40 DETAILED DESCRIPTION OF THE INVENTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. However, the drawings and a description thereof correspond to the exemplary embodiments among various methods for effectively explaining the features of the present invention, and the 45 present invention is not limited by the drawings and the description thereof. Further, in the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are those defined, considering the functions of the present invention, 50 and may be changed according to the intentions of the user or the manager or the 6 customs. Therefore, the definitions of the terms should be made based on the contents of the specification. Functional elements already provided in a system or generally provided in the art to which the present invention pertains can be omitted from the exemplary 55 embodiments of the present invention to effectively explain the technical elements of the present invention. Thus, functional elements that should be additionally provided for the present invention will be mainly described. Among functions of elements that are not illustrated but omitted, the functions of conventional elements can be easily understood by those skilled in the 60 art to which the present invention pertains, and relationships between the omitted elements and the elements added for the present invention will be clearly understood. In the description of the embodiment of the present invention, terms will be properly modified to effectively explain the technical features of the present invention 65 so that those skilled in the art to which the present invention pertains can clearly understand the present invention, but the present invention is not limited thereto. As a result, the technical spirit of the present invention is determined by the claims, and the embodiments of the present invention are provided to merely effectively explain the technical spirit of the present invention to those skilled in the 70 art to which the present invention pertains. FIG. 1 is a perspective view illustrating an entire appearance of a face washing machine according to an embodiment of the present invention. FIG. 2 is a vertical sectional view taken along the line A-A of FIG. 1. FIG. 3 is a perspective view illustrating main parts such as an electric motor, 75 a spring, and a support of a face washing machine according to an embodiment of the present invention. FIG. 4 is an exploded perspective view of FIG. 3. FIG. 5 is a view illustrating operation of a spring employed in a face washing machine according to an embodiment of the present invention. 80 FIG. 6 is a sectional view illustrating an example of bristle employed in a 7 face washing machine according to an embodiment of the present invention. A face washing machine according to an embodiment of the present invention includes a face-washing case 100, an operating unit 200, a power supply 300, a brushless DC (BLDC) motor 400, a controller 500, a face-washing brush 600, 85 a holder 700, a plate spring 800, and a support 900. A reference numeral 1000 serves as a weight to keep balance. First, the face-washing brush 600 as an essential element of the face washing machine according to an embodiment of the present invention includes a first bristle set 610 having a first feature and a second bristle set 620 of a second 90 feature. The first bristle set 610 and the second bristle set 620 are made by combining a plurality of bristles 611 and 621 respectively and a front side of the case 100 is divided into an electric motor-connecting panel 110 and a fixed panel 120m, while the first bristle set 610 is inserted into the electric motor-connecting panel 110 95 of the case by an interval and the second bristle set 620 is inserted into the fixed panel 120 of the case by an interval. The electric motor-connecting panel 110 is preferably formed with five lanes of holes such as six holes, twelve holes, twenty one holes, twenty seven holes, and thirty three holes from the innermost side. The fixed panel 120 is formed with two 00 lanes of holes having 39 holes respectively. Each of the holes is preferably 1.8 mm to 20.mm wide and 3.6 mm deep such as 450 to 850 bristles are coupled in one hole. The respective bristles of the first bristle set and the second bristle set are preferably 63±10 micrometers thick and 9.0±1.0 mm long and total of the bristles is 05 preferably 90,000 to 120,000. As occasion demands, the first bristle set has a first color and the second bristle set has a second color different from the first color so that a rotating portion and a fixed portion can be recognized easily. The bristles 611 and 621 are made of nylon. Nylon resin is classified into Nylon 6, Nylon 66, and Nylon 610 according to manufacturing methods wherein the 10 numbers indicate the number of carbon atoms contained in a monomer before 8 polymerization. Nylon 612 is mainly used in manufacturing the bristles 611 and 621. Since the bristles should be extruded method due to characteristics of the bristles, materials are selected by distinguishing resin from resin for injection. That is, Zytel 15 FE3071 (Du Pont) has a heat transformation temperature of about 246 Celsius degrees and thus is suitable for resin for extrusion. The case 100 of the face washing machine has an outer appearance held by a hand, accommodates the power supply and the BLDC motor therein, and is disposed with the operating unit at an outer side. The front side of the case 100 is 20 divided into the electric motor-connecting panel 100 and the fixed panel 120, while the first bristle set 610 is inserted into the electric motor-connecting panel 110 of the case by an interval and the second bristle set 620 is inserted into the fixed panel 120 by an interval. The electric motor-connecting panel moves rightward and leftward when the BLDC motor rotates. 25 The operating unit 200 is installed on the outer side of the case in the form of a toggle switch or a pushbutton to command power ON/OFF and forward/reverse rotation by an angle and to lead the BLDC motor to rotate forward and reversely by a desired angle range. The power supply 300 is installed in the case to supply an electric power to 30 the face washing machine. The power supply may be a battery or a rechargeable battery or may be supplied with an electric power from an external power supply via a cable. The BLDC motor 100 is installed in the case and is driven to rotate forward and reversely by an angle when the power supply supplies an electric power 35 according to a switching signal from the operating unit. The controller 500 detects a counter electromotive force from the BLDC motor to acquire a position of the rotor and outputs an electric signal for controlling the forward and reverse rotation of the BLDC motor by an angle according to the switching signal from the operating unit. 40 The face-washing brush 600 includes the first bristle set 610 and the second 9 bristle set 620 such that the first bristle set rotates forward and reversely by the rotation of the BLDC motor to wash face. The holder 700 includes an L-shaped vertical panel 700a and a horizontal panel 700b which are connected to the shaft 410 of the BLDC motor 400, and 45 rotates forward and reversely according to the forward and reverse rotation of the BLDC motor 400. The spring 800 has an end coupled to a lower side of the horizontal panel of the holder 700 and the end coupled to the support 900, moves the support 900 toward the shaft and provides an elastic force to generate a torque applied toward an 50 original position when the holder 700 moves vertically. Preferably, the spring 800 is a plate spring of a rectangular panel. That is, a coil spring may be employed as occasion demands but a plate spring is employed for powerful instant torque. When a plate spring is employed, the holder 700 is formed with a moving hole 710 such that the spring is coupled to slide so that horizontal movement of the spring 800 can 55 be easily achieved. The BLDC motor 400 employed in the face washing machine according to an embodiment of the present invention includes a stator generating a rotating magnetic field in which a permanent magnet rotate spatially, a rotor generating a magnetic field with a permanent magnet is installed therein, synchronized with a 60 rotation velocity of the rotation magnetic field to rotate relatively, and a separated controller controlling the rotation of the BLDC motor. The purpose of detecting a position of the rotor of the BLDC motor 400 is an ideal control without torque ripple and to this end both of voltage and current should be sine wave. In order to drive the BLDC motor 400, an early driving algorithm is 65 needed because an initial position of the rotor cannot be known even in any control method and even in this case an early driving algorithm is needed because an induced electromotive force can be obtained only when the rotor rotates once. This early driving algorithm is already known in every control of the BLDC motor 400, a commonly known force arranging method is used even in this case and thus its 70 detailed description will be omitted.
10 As such, if the initial position of the rotor is obtained, the rotor is synchronized with a preset order until rotational frequency reaches a preset velocity such that an induced electromotive force is generated. From this section, a sine wave control starts. In general, a PWM control identical to a sine wave control of an 75 AC induction motor is applied as the driving method. However, various methods such as a triangle wave method, a sawtooth wave method and a circle approximation method may be applied to a carrier frequency. The zero crossing points (ZCP) through which the respective phase induced electromotive forces obtained from rotation of the rotor pass through the zero cross 80 are detected and phase inversion is carried out based on information of the ZCP to output PWM driving signals to corresponding phases. The BLDC motor is driven due to three-phase conduction from this and the current wave has a sine wave. In this case, for the easy detection of ZCP, a winding of the BLDC motor 400 is preferably a distributed winding. 85 Hereinafter, overall operation of the face washing machine according to an embodiment of the present invention will be described. When a user turns a power switch on, the BLDC motor is driven. In the present embodiment, the control circuit is programmed to rotate the BLDC motor 400 forward and reversely while the first bristles 611 of the first bristle 90 set 610 of the face-washing brush 600 rotates forward and reversely. That is, the rotor of the BLDC motor 400 rotates by an angle and the position of the rotor is checked using an induced electromotive force to rotate the rotor forward and reversely, and the forward and reverse rotation of the rotor is repeated such that the forward and reverse rotation of the first bristles 611 of the first bristle 95 set 610 of the face-washing brush 600 is repeated. The second bristle set 620 of the face-washing brush 600 is fixed and then foreign matters on face are not spattered out during the forward and reverse rotation of the first bristle set 610 but are blocked and filtered by the second bristles 621 of the second bristle set 620. 00 That is, since the first bristle set 610 rotates forward and reversely but the 11 second bristle set 620 keeps stopping, the second bristles 621 of the second bristle set 620 catch all the foreign matters even when the foreign matters are spattered out during the forward and reverse rotation of the first bristle set 610 so that the foreign matter are not spattered out. 05 Since ends of the first bristles 611 are rounded, the first bristles 611 do not apply a great stimulus to face but scrub face softly so that more soft and easy face washing of a user's face is enabled and massage effect can be also provided. In this case, since the spring 800 is coupled with the holder 700 of the BLDC motor 400, the spring 800 is transformed due to the forward and reverse rotation of 10 the holder 700. That is, the spring 800 is bent clockwise when the holder 700 rotates clockwise, and is bent counterclockwise when the holder 700 rotates counterclockwise. Since the spring 800 is made of material with an elastic restoring force, a 15 strong torque is applied and the restoring force becomes maximum at the end of the rotation of the BLDC motor 400 when the holder 700 rotates due to the rotation of the BLDC motor 400 and the spring 800 is bent. Thus, the face-washing brush 600 rotates very fast forward and reversely. The spring 800 is bent maximum after the BLDC motor 400 rotates by an 20 angle. In this case, when a reverse rotational force of the BLDC motor 400 is applied, and a spring force is added and then a face reverse rotation is generated. Since the spring 800 is restored to the original position and is bent maximum in other direction again at the time when the reverse rotation reaches to an end, an instant maximum torque is applied the reverse rotation is fast converted into the forward 25 rotation when the reverse rotation is converted into the forward rotation. As such, since the BLDC motor 400 changes the rotation direction fast from the forward rotation to the reverser rotation and vice versa, a strong torque is applied to the face-washing brush 600 so that face can be washed with a stronger force. Following table is obtained by comparing effects obtained by washing face 30 with the face washing brush made of nylon according to an embodiment of the 12 present invention with effects obtained by washing face with hands. [Table 1] Pores on cheeks With hands With nylon Before use 45.26 37.86 After use 35.00 19.91 Reduced rate 22.70% 48.56% 35 In the above Table, the number of pores on cheeks having a diameter greater than a preset diameter is counted. The number of pores is reduced by 22.70% when face is washed with hands but by 48.56% when face is washed by rotating the brush bristles of nylon according to an embodiment of the present invention. Thus, it is understood that the number of pores on cheeks is remarkably 40 reduced when the face washing brush of nylon according to an embodiment of the present invention is used. [Table 2] Pores on nose With hands With nylon Before use 12.33 15.43 Directly after use 10.82 12.39 After two weeks 10.92 11.65 After four weeks 9.96 11.06 Reduced rate (four 18.6% 28.3% weeks) In the above Table, the number of pores on nose having a diameter greater 45 than a preset diameter is counted. The number of pores is reduced by 18.6% at four weeks after face is washed with hands but by 28.3% at four weeks after face is washed by rotating the brush bristles of nylon according to an embodiment of the present invention. Thus, it is understood that the number of pores on nose is remarkably reduced when the face washing brush of nylon according to an 13 50 embodiment of the present invention is used. [Table 3] Dead skin cells With hands With nylon Before use 7.22 7.45 Directly after use 6.54 6.36 After two weeks 5.61 5.37 After four weeks 5.41 4.34 Reduced rate (four 25.1% 41.7% weeks) In the above Table, as a result of comparing removal of dead skin cells, the dead skin cells are reduced by 25.1% at four weeks after face is washed with hands 55 but by 41.7% at four weeks after face is washed by rotating the brush bristles of nylon according to an embodiment of the present invention. Thus, it is understood that the dead skin cells are remarkably reduced when the face washing brush of nylon according to an embodiment of the present invention is used. [Table 4] 60 Changes on skin pigmentation With hands With nylon Before use 146.00 129.28 After two weeks 145.65 121.80 After four weeks 145.57 116.81 Reduced rate (four 0.3% 9.6% weeks) In the above Table, changes of skin tone is obtained by analyzing melanin index on pigmentation of skin, is reduced by 0.3% at four weeks after face is washed with hands but by 9.6% at four weeks after face is washed by rotating the brush bristles of nylon according to an embodiment of the present invention. Thus, 65 it is understood that the melanin index is remarkably reduced when the face washing brush of nylon according to an embodiment of the present invention is 14 used and thus skin is changed bright. [Table 5] Eye wrinkles (um, Rmax (maximum depth of wrinkle)) With hands With nylon Before use 223.11 185.53 After two weeks 218.50 176.64 After four weeks 219.19 167.04 Reduced rate (four 1.8% 10.0% weeks) 70 In the above Table, the depth of eye wrinkles is reduced by only 1.5% when face is washed with hands but is reduced by 10.8% when face is washed by rotating the brush bristles of nylon according to an embodiment of the present invention. Thus, it is understood that the eye wrinkles are remarkably reduced when the face washing brush of nylon according to an embodiment of the present invention is 75 used.