Abstract:
A appliance control panel assembly includes a control panel; a plurality of light emitting diodes (LEDs); a bracket to accommodate the LEDs, the bracket including a plurality of light guide holes for guiding light from the LEDs; and a window for allowing the light from the LEDs and guided through the light guide holes to be visible at a front of the control panel. Each of the light guide holes includes a first portion to accommodate one of the plurality of LEDs, and a second portion to guide light emitted from the LED towards the window. The length of the second portion is longer than a length of the first portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 14/535,847, filed on Nov. 7, 2014, which is a continuation of U.S. application Ser. No. 13/861,200, filed on Apr. 11, 2013, which claims the benefit of Korean Patent Application No. 10-2012-0037716, filed on Apr. 12, 2012 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field 
     Embodiments of the present disclosure relate to a control panel assembly for controlling an operation of a washing machine and a washing machine having the same. 
     2. Description of the Related Art 
     A washing machine as a machine that washes clothes using power, generally includes a tub in which washing water is stored, a drum rotatably installed in the tub, and a driving motor for rotating the drum. When the drum is rotated in a state in which laundry and detergent water are put into the drum, laundry is in friction with the drum and detergent water so that dirt can be removed from laundry. 
     In general, the washing machine includes a control panel assembly disposed at an upper part of a front side of a main body that constitutes the exterior so as to control an operation of the washing machine. 
     As disclosed in Korean Patent Publication No. 10-2008-0103643, the control panel assembly includes a circuit board on which electric components, such as a rotary switch and a light emitting diode (LED), are installed, a control panel that covers the circuit board so as to protect a substrate, a rotary knob rotatably disposed on the control panel for user manipulation, and a display panel disposed on the periphery of the rotary knob. Light emitted from the LED is transmitted forward through the display panel via guide components inside the control panel. 
     However, in the control panel assembly, light emitted from the LED may be diffused into a different position from a predetermined position of the display panel, or intensity of the light emitted from the LED is not uniform according to a position of the display panel. 
     In order to solve these problems, a film is disposed between the LED and the display panel so as to remove diffusion of light or so as to uniformly diffuse light. However, due to an increase in cost required for manufacturing the film and an increase in assembling time required for attaching the film to the control panel assembly, productivity is lowered. 
     SUMMARY 
     Therefore, it is an aspect of the present disclosure to provide a control panel assembly having an improved structure in which light emitted from a light emitting diode (LED) may be uniformly diffused, and a washing machine having the control panel assembly. 
     Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure. 
     In accordance with one aspect of the present disclosure, there is provided a washing machine having a control panel assembly for controlling an operation of the washing machine, wherein the control panel assembly includes: a control panel; a circuit board disposed at an inner side of the control panel; at least one light emitting diode (LED) disposed on the circuit board and configured to emit light; an LED bracket coupled to the circuit board, configured to accommodate the at least one LED to guide light emitted from the LED to front of the control panel, and having at least one light guide hole, of which a cross-sectional area is not uniform in at least a portion of the light guide hole in a direction in which the light emitted from the LED is guided; and an LED window disposed at a front side of the LED bracket and configured to allow the light emitted from the LED to be transmitted to front of the control panel. 
     The light guide hole may include: first light guide holes configured to accommodate the LED; and second light guide holes formed to have a step height with respect to the first light guide holes. 
     Each second light guide hole may be relatively longer than each first light guide hole. 
     A cross-sectional area of each first light guide hole may be gradually decreased and a cross-sectional area of each second light guide hole may be gradually increased along a proceeding path of the light emitted from the at least one LED. 
     The LED window may include: a light transmission part configured to allow the light emitted from the LED to be transmitted to front of the control panel; and a light diffusion part configured to allow the light emitted from the LED to be uniformly diffused when passing through the light transmission part, and the light diffusion part may include uneven forms formed at a rear side of the LED window corresponding to the front side of the LED bracket. 
     The LED window may include: a light transmission part configured to allow the light emitted from the LED to be transmitted to front of the control panel; and a light diffusion part configured to allow the light emitted from the LED to be uniformly diffused when passing through the light transmission part, and the light diffusion part may include a film member attached to or inserted into the LED window. 
     The light transmission part may include light transmission protrusions disposed in positions corresponding to the light guide hole on a path of the light emitted from the at least one LED, and the light guide hole may be provided in a polygonal form so as to prevent light emitted from the LED from being diffused into other light transmission protrusions than the light transmission protrusions corresponding to the light guide hole. 
     The control panel assembly may include a knob guide disposed at a front side of the LED window and a rotary knob rotatably mounted on the knob guide, and the light guide holes may be spaced apart from each other by a predetermined gap in a ring form based on a rotation shaft of the rotary knob, and the light transmission part may include a plurality of light transmission protrusions spaced apart from each other by a predetermined gap in positions corresponding to the light guide holes based on the rotation shaft of the rotary knob. 
     The knob guide may include a plurality of through holes formed in positions corresponding to the plurality of light transmission protrusions so that the plurality of light transmission protrusions are inserted into the plurality of through holes and are exposed to a front side of the control panel. 
     The LED bracket and the LED window may be formed integrally with each other. 
     In accordance with another aspect of the present disclosure, there is provided a control panel assembly for controlling an operation of an electronic product, including: a control panel; a circuit board disposed at an inner side of the control panel; at least one light emitting diode (LED) disposed on the circuit board and configured to emit light; a light guide part coupled to the circuit board, configured to accommodate the at least one LED, and having at least one light guide hole, of which a cross-sectional area is not uniform in at least a portion of the light guide hole in a direction in which the light emitted from the LED is guided; a light transmission part coupled to the control panel and having a base plate disposed at front of the light guide part and at least one light transmission protrusion configured to protrude from a front side of the base plate and allow light passing through the light guide hole to be transmitted to front of the control panel; and a light diffusion part disposed at a rear side of the base plate in an uneven form and configured to allow the light emitted from the LED to be uniformly diffused when passing through the light transmission protrusion. 
     The light guide hole may include: first light guide holes configured to accommodate the LED; and second light guide holes formed to have a step height with respect to the first light guide holes. 
     A cross-sectional area of each second light guide hole may be smaller than a cross-sectional area of each first light guide hole. 
     The cross-sectional area of each first light guide hole may be gradually decreased and the cross-sectional area of each second light guide hole may be gradually increased along a proceeding path of the light emitted from the at least one LED. 
     The cross-sectional area of the light guide hole may be provided in a polygonal form. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a perspective view illustrating the exterior of a washing machine according to an embodiment of the present disclosure; 
         FIG. 2  is an exploded perspective view illustrating a structure of a control panel assembly of the washing machine illustrated in  FIG. 1 , according to an embodiment of the present disclosure; 
         FIG. 3  is a cross-sectional view illustrating a combined state of the control panel assembly illustrated in  FIG. 2 ; 
         FIG. 4  is an enlarged cross-sectional view of a portion A of  FIG. 3 ; 
         FIG. 5  is a cross-sectional view of a light emitting diode (LED) bracket; 
         FIG. 6  is an enlarged view of a portion B of  FIG. 5 ; and 
         FIGS. 7A through 7C  illustrate an operation of assembling the control panel assembly of  FIG. 2  of the washing machine of  FIG. 1 , according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
       FIG. 1  is a perspective view illustrating the exterior of a washing machine according to an embodiment of the present disclosure. 
     As illustrated in  FIG. 1 , the washing machine includes a main body  10  that constitutes the exterior, a tub (not shown) which is installed in the main body  10  and in which washing water is stored, and a drum  12  that is rotatably disposed in the tub so as to wash laundry. A laundry port  13  through which laundry may be put into the drum  12 , is formed at a front side of the main body  10 , and a door  14  is installed to open/close the laundry port  13 . A control panel assembly  100  is disposed at an upper part of the front side of the main body  10  so that a user may control an operation of the washing machine. 
       FIG. 2  is an exploded perspective view illustrating a structure of the control panel assembly  100  of the washing machine illustrated in  FIG. 1 , according to an embodiment of the present disclosure,  FIG. 3  is a cross-sectional view illustrating a combined state of the control panel assembly  100  illustrated in  FIG. 2 ,  FIG. 4  is an enlarged cross-sectional view of a portion A of  FIG. 3 ,  FIG. 5  is a cross-sectional view of a light emitting diode (LED) bracket, and  FIG. 6  is an enlarged view of a portion B of  FIG. 5 . 
     As illustrated in  FIGS. 2 through 6 , the control panel assembly  100  includes a control panel  110  having one side in which an opening  111  is formed and a circuit board  120  mounted at an inner side of the control panel  110 . 
     A rotary switch  121  is installed at the circuit board  120 , and a plurality of LEDs  122  are installed on the periphery of the rotary switch  121 . The rotary switch  121  includes a push shaft  121   a  that protrudes forward and a rotation shaft  121   b  that surrounds a lower side of the push shaft  121   a . A rotary knob  160  is combined with the rotary switch  121 . The user may rotate the rotation shaft  121   b  of the rotary switch  121  via the rotary knob  160  or may press the push shaft  121   a  to select various operations of the washing machine, such as a washing course, a washing time, and the like. 
     Also, an LED bracket  130  is installed at the circuit board  120 . The LED bracket  130  includes a light guide part  131  that accommodates and protects the plurality of LEDs  122  and simultaneously guides light emitted from the LEDs  122  toward the front of the control panel  110 . 
     A first through hole  132  through which the rotation shaft  121   b  and the push shaft  121   a  of the rotary switch  121  pass, is formed in the center of the LED bracket  130 . 
     The light guide part  131  includes a plurality of light guide holes  131   a  that are formed on the periphery of the first through hole  132  and are spaced apart from each other by a predetermined gap in a circumferential direction of the LED bracket  130 . 
     As shown in  FIG. 3 , the plurality of light guide holes  131   a  include first light guide holes  133  in which the LEDs  122  are accommodated and second light guide holes  134  formed to have a step height with respect to the first light guide holes  133 . The first light guide holes  133  and the second light guide holes  134  may be formed in an approximately rectangular form so as to prevent light emitted from the LEDs  122  from being diffused. That is, the first light guide holes  133  and the second light guide holes  134  are provided in the rectangular form. Thus, when light emitted from the LEDs  122  passes through the light guide holes  131   a , the light is guided toward one light transmission protrusion  142   a  disposed in a position corresponding to the light guide holes  131   a  on a path of light emitted from the LEDs  122  and proceeds, thereby preventing light from being diffused to other light transmission protrusions that do not correspond to the light guide holes  131   a . Furthermore, since the second light guide holes  134  are formed to have a step height with respect to the first light guide holes  133  and the cross-sectional area of each second light guide hole  134  is smaller than that of each first light guide hole  133 , there is the effect of focusing light emitted from the LEDs  122 . 
     The cross-sectional area of the first light guide hole  133  may be gradually decreased and the cross-sectional area of the second light guide hole  134  may be gradually increased along the proceeding path of light emitted from the LEDs  122 , so as to easily remove a mold for forming the first light guide holes  133  and the second light guide holes  134  when the LED bracket  130  is injection molded using plastic. 
     The shape of the first light guide holes  133  and the second light guide holes  134  is not limited to the rectangular shape and may be all polygonal shapes in which diffusion of light emitted from the LEDs  122  may be prevented. 
     Also, each second light guide hole  134  may be relatively longer than each first light guide hole  133 , so as to allow light emitted from the LEDs  122  to be further focused when light emitted from the LEDs  122  proceeds forward along the second light guide holes  134 . 
     The degree to which light emitted from the LEDs  122  is focused may be determined by a ratio (L2/L1) of a length L2 of the second light guide hole  134  to a length L1 of the first light guide hole  133 . The ratio (L2/L1) of the length L2 of the second light guide hole  134  to the length L1 of the first light guide hole  133  may be approximately equal to or greater than 1.5 and equal to or less than 5. The reason why the ratio (L2/L1) of the length L2 of the second light guide hole  134  to the length L1 of the first light guide hole  133  has a predetermined range is that, as the length L2 of the second light guide hole  134  increases, the effect of focusing light emitted from the LEDs  122  increases but the thickness of the LED bracket  130  in which the second light guide holes  134  are formed increases. Of course, the ratio (L2/L1) of the length L2 of the second light guide hole  134  to the length L1 of the first light guide hole  133  is not limited to being equal to or greater than 1.5 and equal to or less than 5 and may be equal to or less than 1.5 or equal to or greater than 5 according to design specifications. 
     In this way, the cross-sectional areas or lengths of the light guide holes  131   a  may be properly adjusted so that light emitted from the LEDs  122  may reach a desired position with a desired degree of focusing. 
     An LED window  140  and a knob guide  150  are installed at the opening  111  of the control panel  110 , and the rotary knob  160  is combined with the front of a knob guide  150 . The knob guide  150  supports the rotary knob  160  and prevents movement of the rotary knob  160 . The LED window  140  serves to display a function selected through a rotation or pressing operation of the rotary knob  160 , so that the user may identify the function. 
     The LED window  140  includes a ring-shaped base plate  141  coupled to a rear side of the knob guide  150 , a light transmission part  142  formed in a circumferential direction of the ring-shaped base plate  141 , and a light diffusion part  143  formed at a rear side of the base plate  141  corresponding to the front side of the LED bracket  130 . 
     The light transmission part  142  includes a plurality of light transmission protrusions  142   a  that are spaced apart from each other by a predetermined gap in the circumferential direction of the ring-shaped base plate  141  and protrude from the front side of the base plate  141  so that light passing through the light guide holes  131   a  of the LED bracket  130  may be transmitted to the front of the control panel  110 . 
     The light diffusion part  143  is configured in many uneven forms formed in units of approximately several micrometers to several hundreds of micrometers at the rear side of the base plate  141 . The uneven forms may be formed by performing corrosion treatment on the rear side of the base plate  141  or by mechanical processing and may be pre-formed on a mold for injection-molding the LED window  140 . 
     Also, instead of forming protrusions in the uneven forms at the rear side of the base plate  141 , the light diffusion part  143  may be provided by attaching a thin material, such as a film, of which surface treatment for diffusing light is performed, to the front side or rear side of the base plate  141  of the LED window  140  or by inserting the thin material, such as the film, when the LED window  140  is injection molded. 
     The light diffusion part  143  allows light emitted from the LEDs  122  and passing through the LED bracket  130  to be uniformly diffused into one light transmission protrusion  142   a  and to be transmitted by the light transmission protrusions  142   a , thereby generating the effect of appealing lighting. 
     The LED bracket  130  and the LED window  140  may be formed integrally with each other using a manufacturing method, such as injection molding. In this case, since it is not easy to additionally form uneven protrusions at the rear side of the base plate  141 , the thin material, such as the film, of which surface treatment for diffusing light is performed, may be inserted when the LED bracket  130  and the LED window  140  are integrally injection molded. 
     The knob guide  150  includes a base panel  151  on which the rotary knob  160  is mounted, hanging jaws  152  that protrude from a circumference of the base panel  151 , and a plurality of second through holes  153  that are spaced apart from each other by a predetermined gap in the circumferential direction of the base panel  151 . A character or symbol is printed on the circumference of the base panel  151  so that the user may identify an operation selected by the rotary knob  160 . The hanging jaws  152  are hung on the periphery of the opening  111  when the knob guide  150  is installed at the control panel  110 . The plurality of second through holes  153  are formed through the base panel  151  in a position corresponding to the light transmission protrusions  142   a  so that the plurality of light transmission protrusions  142   a  may be inserted into the plurality of second through holes  153  and may be exposed to the front side of the control panel  110 . 
     Also, the knob guide  150  includes a boss insertion part  154  that protrudes from the center of the knob guide  150  and at least one first hook  155  disposed on a circumference of the boss insertion part  154 . The boss insertion part  154  includes a boss insertion hole  154   a  through which a boss  161  of the rotary knob  160  may be inserted into the boss insertion part  154 . The boss insertion part  154  confines the boss  161  of the rotary knob  160  so as to prevent movement of the rotary knob  160 . The first hook  155  allows a second hook  162  of the rotary knob  160  to be engaged with the first hook  155  so that the rotary knob  160  may be rotatably mounted on the knob guide  150 . Also, the first hook  155  prevents the rotary knob  160  from being deviated when the user pulls the rotary knob  160 . 
     The rotary knob  160  includes a boss  161  that extends from an inner side of the rotary knob  160  toward the center of the knob guide  150  to a predetermined length, and at least one second hook  162  disposed on a circumference of the boss  161 . The boss  161  is inserted into the boss insertion part  154  when the rotary knob  160  is mounted on the knob guide  150 , and a shaft insertion hole  161   a  is formed in the boss  161  so that the push shaft  121   a  of the rotary switch  121  may be inserted into the shaft insertion hole  161   a . As described above, the second hook  162  is coupled to the first hook  155  so that the rotary knob  160  may be rotatably mounted on the knob guide  150 . 
     In  FIG. 2 , three first hooks  155  and three second hooks  162  are disposed in the circumferential direction of the knob guide  150  and in the circumferential direction of the rotary knob  160 , respectively. However, the number of first hooks  155  and second hooks  162  may be changed according to design requirements. 
     Also, in  FIG. 3 , the first hook  155  and the second hook  162  are engaged with each other so that the rotary knob  160  may be coupled to the knob guide  150 . However, a hook may be formed at either of the rotary knob  160  and the knob guide  150 , and a coupling hole to be coupled to the hook is formed at the other one of the rotary knob  160  and the knob guide  150  so that the rotary knob  160  and the knob guide  150  may be coupled to each other. 
     Hereinafter, an operation of assembling the control panel assembly  100  of the washing machine according to the present disclosure will be described. 
       FIGS. 7A through 7C  illustrate an operation of assembling the control panel assembly  100  of  FIG. 2  of the washing machine of  FIG. 1 , according to an embodiment of the present disclosure. 
     First, as illustrated in  FIG. 7A , when the knob guide  150  is inserted into the opening  111  of the control panel  110  at the rear of the control panel  110  in a state in which the LED window  140  is coupled to the knob guide  150 , the base panel  151  and the light transmission part  142  are exposed to the front of the control panel  110  through the opening  111 . The LED bracket  130  is combined with the circuit board  120  so as to accommodate and protect the rotary switch  121  and the LEDs  122  installed at the circuit board  120 . In this case, the push shaft  121   a  and the rotation shaft  121   b  of the rotary switch  121  protrude forward through the first through hole  132 . 
     Next, as illustrated in  FIG. 7B , the circuit board  120  is fixed to the control panel  110  on which the knob guide  150  is installed, using a fastening member, such as a screw. Then, the push shaft  121   a  and the rotation shaft  121   b  of the rotary switch  121  are exposed to the front of the control panel  110  via the boss insertion part  154  of the knob guide  150 . 
     Subsequently, as illustrated in  FIG. 7C , the rotary knob  160  is combined with the knob guide  150  at the front of the control panel  110 . In this case, the boss  161  of the rotary knob  160  is inserted into the boss insertion part  154 , and the second hook  162  of the rotary knob  160  is engaged with the first hook  155  of the knob guide  150 . When the boss  161  of the rotary knob  160  is inserted into the boss insertion part  154 , the push shaft  121   a  of the rotary switch  121  is inserted into the shaft insertion hole  161   a  formed in the boss  161  and is coupled to the boss  161 . 
     It is apparent that the above-described control panel assembly  100  may be applied to not only a washing machine but also all electronic products that require operation control with user manipulation, such as a drying machine, a dishwasher, and the like. 
     As described above, according to the embodiments of the present disclosure, since light emitted from a plurality of LEDs is uniformly diffused, the effect of appealing lighting can be achieved and good impression can be given to the user so that the reliability of a product can be improved. 
     In addition, no additional component, such as a film, is required so that the productivity of the product can be improved. 
     Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.