Patent Publication Number: US-7899398-B2

Title: Portable karaoke system

Description:
TECHNICAL FIELD 
     The present invention relates to a portable Karaoke system, and more particularly, to a portable Karaoke system that has a separate radio auxiliary microphone receiving module and a separate FM transmission module, which can be inserted/separated into/from the portable Karaoke system, and a battery case structure for preventing a battery set in a battery case from being easily separated therefrom due to an external shock and allowing a user to easily remove the battery from the battery case, and allows the user to selectively combine a general microphone net and a ball-type microphone net with the Karaoke system such that the user can easily carry and keep the portable Karaoke system. 
     BACKGROUND ART 
     A conventional portable Karaoke system includes a microphone for converting a user&#39;s voice into an electric signal to output it through a speaker, a key unit through which a user selects a song, a display for displaying the operation state of the portable Karaoke system, and a control circuit for storing accompaniment data with respect to songs and video signals corresponding to background images and processing the stored signals. The microphone is placed on the top of a case of the portable Karaoke system, and the key unit and the display are attached to one side of the case. The control circuit is constructed on a board that is set inside the case. 
     The conventional portable Karaoke system radio-transmits the accompaniment sound, lyrics and background image of a song the user selects through the key unit to an image display device such as TV to display the lyrics and background image on a screen of the image display device and to output the accompaniment sound through a speaker included in the image display device. The accompaniment sound can be output through a home audio system or a car audio system and the user can sing to the accompaniment sound, holding the main body of the portable Karaoke system by the hand. 
     In the conventional portable Karaoke system, however, all of a circuit for radio-receiving video and audio signals, the control circuit and a transmission circuit are constructed on the board set in the case of the system. This increases the size of the board and thus the user has a difficulty in holding the portable Karaoke system by the hand to sing a song. 
     Furthermore, many countries including Korea increasingly put restrictions on frequencies of radio transmission devices. Thus, the portable Karaoke system cannot avoid the restrictions on the frequencies when a radio transmission circuit is constructed on the board provided in the system. 
       FIG. 1  is a cross-sectional view of the conventional portable Karaoke system including a modularized transmitting/receiving device. The portable Karaoke system includes a microphone  3  provided at one end of a case  1 , a key unit  2  through which a user selects a song, and a display  4 . The portable Karaoke system further includes an open part  10  located on one side of the case  1 , an accommodating part  11  extended from the end of the case  1 , a first connector  13 , a transmitting/receiving module  15 , and a cover  16 . One end of the accommodating part  11  is opened and connected with the inside of the case  1 . The first connector  13  is placed on a board  12  set inside the case  1  and protruded to the inside of the accommodating part  11 . The transmitting/receiving module  15  is formed such that it can be inserted into the accommodating part  11  and includes a transmitting/receiving circuit for transmitting/receiving video and audio signals. The transmitting/receiving module  15  has a second connector  14  formed at one end thereof. The second connector  14  is connected to the first connector  13  to connect the transmitting/receiving circuit to the control circuit of the portable Karaoke system. The cover  16  covers the open part  10  of the case  1 . 
     The transmitting/receiving module  15  further includes an FM transmitter circuit (not shown), a receiving antenna, and a radio auxiliary microphone receiver circuit (not shown). The FM transmitter circuit has a transmission antenna that modulates an audio signal output from the portable Karaoke system into a predetermined FM frequency and then transmits the modulated signal to an external FM radio. The receiving antenna receives a radio signal transmitted from a radio auxiliary microphone separated from the portable Karaoke system. The wireless auxiliary microphone receiver circuit demodulates the radio signal received by the receiving antenna and divides the demodulated signal into an audio signal and a song data signal. 
     A user can easily connect/disconnect the transmitting/receiving module  15  to/from the portable Karaoke system to use the system. However, since the transmitting/receiving module  15  includes both of the FM transmitter circuit and the radio auxiliary microphone receiver circuit, the user cannot select and use one of FM transmission and radio auxiliary microphone receiving functions. Furthermore, the user should purchase an unnecessary functional module. Moreover, the volume of the transmitting/receiving module  15  becomes large because it includes even the transmission antenna and the receiving antenna. Accordingly, the user has a difficulty in carrying the portable Karaoke system including the transmitting/receiving module  15 . 
       FIG. 2  is a perspective view of a conventional portable Karaoke system having a battery housing structure. Referring to  FIG. 2 , the portable Karaoke system includes a case  20  a user can easily hold and a signal connecting device (not shown) for connecting the case  20  to external apparatuses (for example, an audio system, TV set and so on). 
     A microphone net  21  is set on the top of the case  20  and a printed circuit board  22  including various electronic components for operating the portable Karaoke system is set inside the case  20 . A key input unit  23  having a plurality of key buttons (not shown) electrically connected to the printed circuit board  22  is provided on one side of the case  20 . In addition, a battery case  24  for housing at least one battery for supplying power to the portable Karaoke system is arranged on the other side of the case. 
     The battery case  24  has a rectangular groove in which batteries are serially connected in the direction of the length thereof. Contact terminals  25  and  25 ′ are respectively set at both ends of the battery case to be electrically connected to the printed circuit board  22 . The contact terminals  25  and  25 ′ are respectively made of a metal plate and a spring. 
     The portable Karaoke system further, includes a cover  26  for covering the case  20 . The case  20  and the cover  26  are tightly combined such that a part of the case is fitted in the cover  26 . An input/output terminal  27  to which a main jack of the signal connecting device is connected is formed at the bottom of the case  20 . 
     To use the portable Karaoke system, the user inserts a predetermined battery into the battery case  24 , arranging the positive and negative polarities of the battery, and combines the cover  26  with one side of the case  20 . Here, a space exists between the battery in the battery case  24  and the cover  26  so that the battery is easily separated from the battery case when an external shock is applied to the case. Thus, the portable Karaoke system is not operated. 
     To replace the battery with a new one, the cover  26  is separated from the case  20  and the battery fitted in the battery case  24  is removed from the battery case. At this time, the battery should be separated from the battery case by putting a thin long hard substance, such as a fingernail, between the end of the battery case and the end of the battery and removing the battery. However, the user has a difficulty in removing the battery from the battery case when he/she has a short fingernail. Furthermore, the user cannot replace the battery with a new one rapidly if he/she is difficult to find a thin long hard substance. 
     Moreover, the conventional portable Karaoke system has a single gear formed at the end of the case, which is combined with a microphone cartridge, such that only one of a general microphone net or a ball-type microphone net can be combined with the case through the gear. Thus, the user cannot selectively use the general microphone net and the ball-type microphone net. 
     DISCLOSURE OF INVENTION 
     Accordingly, an object of the present invention is to provide a portable Karaoke system having a separate radio auxiliary microphone receiving module and a separate FM transmission module, which can be inserted/separated into/from the portable Karaoke system, such that a user can select and purchase only a required function module and easily carry and keep the portable Karaoke system. 
     Another object of the present invention is to provide a portable Karaoke system having hooks, which are provided at both sidewalls of a battery case to prevent a battery from being easily separated from the battery case, and semicircular recesses, which are formed at the top edges of both sidewalls of the battery case to allow a user to easily remove the battery from the battery case. 
     Yet another object of the present invention is to provide a portable Karaoke system having first and second gears formed at stepped portions of the end of a microphone body such that the first gear is combined with a general microphone net and the second gear is combined with a ball-type microphone net. 
     To accomplish the object, according to the present invention, there is provided a portable Karaoke system including: a case forming the external shape of the portable Karaoke system; a printed circuit board that is set in the case and includes a control circuit for operating the Karaoke system: an FM transmission board including a transmission circuit for modulating an audio signal output from the portable Karaoke system into a predetermined FM frequency and radio-transmitting the modulated signal to an external radio; an FM transmission module having a first connector electrically connected to an output signal line of the FM transmission board, the FM transmission module being constructed in a separate single pack; a second connector that is arranged in a predetermined position of the case and connected to the first connector of the FM transmission module to transmit an output signal of the FM transmission module to the control circuit of the printed circuit board; and an antenna wire having a predetermined length, which is arranged in a predetermined position of the case and electrically connected to a transmission antenna terminal of the second connector. 
     Preferably, the case includes an accommodation part for accommodating the radio auxiliary microphone receiving module and the FM transmission module. 
     The accommodation part includes a pair of first guide grooves that are respectively formed in both sidewalls of the accommodation part and guide the radio auxiliary microphone receiving module to its right position, and a pair of second guide grooves that are respectively formed in both sidewalls of the accommodation part and guide the FM transmission module to its right position 
     A first housing forming the body of the radio auxiliary microphone receiving module has a pair of first guide protrusions that are formed on both sides of the first housing and slidably inserted into the first guide grooves in the vertical direction, and a second housing forming the body of the FM transmission module has a pair of second guide protrusions that are formed on both sides of the first housing and slidably inserted into the second guide grooves in the vertical direction. 
     The case includes a battery case into which at least one battery is inserted. 
     The battery case has a pair of hooks having elasticity, which are respectively fixed to both sidewalls of the battery case to prevent the battery from being easily removed from the battery case. 
     The battery case further includes recesses formed at the top edges of both sidewalls of the battery case to allow a user to easily remove the battery from the battery case by the finger. 
     The end of a microphone body of the portable Karaoke system of the present invention, which is combined with a microphone cartridge, has a stepped form. A first gear is formed at a thicker stepped portion and a second gear is formed at a thinner stepped portion. 
     The first gear is combined with a combining ring and a microphone net, and the second gear is combined with a fixing ring and a ball-type microphone net. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a cross-sectional view of a conventional portable Karaoke system including a modularized transmitting/receiving device; 
         FIG. 2  is a perspective view of a conventional portable Karaoke system having a battery housing structure; 
         FIG. 3  is a perspective view of a portable Karaoke system having separable communication modules according to an embodiment of the present invention; 
         FIG. 4  is a perspective view of a radio auxiliary microphone receiving module applied to the portable Karaoke system of the present invention; 
         FIG. 5  is a perspective view of an FM transmission module applied to the portable Karaoke system of the present invention; 
         FIG. 6  is a perspective view of a portable Karaoke system having a battery housing structure according to another embodiment of the present invention; 
         FIG. 7   a  illustrates an operation of inserting a battery into a battery case having hooks, included in the portable Karaoke system according to an embodiment of the present invention; 
         FIG. 7   b  illustrates an operation of removing the battery from the battery case; 
         FIG. 8  illustrates combination of a microphone net and the portable Karaoke system according to an embodiment of the present invention; and 
         FIG. 9  illustrates combination of a ball-type microphone net and the portable Karaoke system according to another embodiment of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     The present invention will now be described in detail in connection with preferred embodiments with reference to the accompanying drawings. For reference, like reference characters designate corresponding parts throughout several views. 
       FIG. 3  is a perspective view of a portable Karaoke system having separable communication modules according to an embodiment of the present invention, and  FIG. 4  is a perspective view of a radio auxiliary microphone receiving module applied to the portable Karaoke system of the present invention.  FIG. 5  is a perspective view of an FM transmission module applied to the portable Karaoke system of the present invention. 
     Referring to  FIG. 3 , the portable Karaoke system according to an embodiment of the present invention includes a case  100  forming the external shape of the portable Karaoke system, a radio auxiliary microphone receiving module  200  that is fitted into the case  100  in a separable manner and receives a radio signal transmitted from a separate radio auxiliary microphone (not shown), an FM transmission module  300  that is fitted into the case  100  in a separable manner and radio-transmits an audio signal output from the portable Karaoke system with a predetermined FM frequency, and a cover  101  that is tightly combined with the case to cover a part of the case  100 . 
     The case  100  has a long shape such that a user can easily hold it to sing a song. A microphone net  110  is set on the top of the case  100 , and a printed circuit board  120  including a control circuit for operating the portable Karaoke system is fitted into the case  100 . 
     Furthermore, a key input unit  130  having a plurality of key buttons electrically connected to the printed circuit board  120  is located on one side of the middle part of the case  100 , and a battery case  140  for housing a battery supplying power to the portable Karaoke system is arranged on the other side of the case  100 . 
     An accommodation part  150  for accommodating a plurality of memory packs (not shown), the radio auxiliary microphone receiving module  200  and the FM transmission module  300  is formed under the battery case  140 . The accommodating part  150  includes a plurality of memory connectors, a male connector  170  for the radio auxiliary microphone receiving module  200  and a male connector  180  for the FM transmission module  300 , which are fixed to the bottom of the accommodating part  150 . The memory connectors and the male connectors  170  and  180  are protruded from the bottom of the accommodation part  150  such that the memory packs and the receiving module  200  and the transmission module  300  can be easily connected with the memory connectors and the male connectors ( 170 , 180 ) and electrically connected to the printed circuit board  120 . The accommodation part  150  has a pair of first guide grooves  151  and  151 ′ respectively formed in both sidewalls of the accommodation part  150  and a pair of second guide grooves  153  and  153 ′ respectively formed in both sidewalls of the accommodation part  150 . The first guide grooves  151  and  151 ′ guide the radio auxiliary microphone receiving module  200  to its right position and the second guide grooves  153  and  153 ′ guide the FM transmission module  300  to its right position. 
     An input/output terminal (not shown) to which a main jack of a separate signal connecting device is connected is provided at the bottom of the case  100 . In addition, a protruded support  190  having a groove  195  is extended from the bottom end of the case  100  such that the protruded support  190  stably supports the main jack of the signal connecting device. Here, the signal connecting device is connected to the input/output terminal to provide video and audio signals transmitted from the portable Karaoke system to an external audio system or display (for example, a TV set or a CRT). 
     Referring to  FIG. 4 , the radio auxiliary microphone receiving module  200  includes a first housing  210  constructing the body of the receiving module  200 , a radio receiving board  220  fitted into the first housing  210 , and a female connector  230  connected to an output signal line of the radio receiving board  220 . The radio receiving board  220  has a radio auxiliary microphone receiving circuit that demodulates a radio signal transmitted from the radio auxiliary microphone and captured by an antenna wire, which will be explained later, and divides the demodulated signal into an audio signal and a song data signal. The female connector  230  is attached to one side of the first housing  210  such that it can be connected with the male connector  170  for the radio auxiliary microphone receiving module  200 , which is placed in the accommodation part  150  of the case  100 . The female connector  230  electrically connects the radio auxiliary microphone receiving circuit to the control circuit of the main body of the portable Karaoke system. The radio auxiliary microphone receiving module  200  further includes a pair of guide protrusions  215  and  215 ′ that are respectively formed on both sides of the first housing  210 . The guide protrusions  215  and  215 ′ are slidably inserted into the first guide grooves  151  and  151 ′ of the case  100  (shown in  FIG. 3 ). 
     Referring to  FIG. 5 , the FM transmission module  300  includes a second housing  310  constructing the body of the FM transmission module, an FM transmission board  320  fitted into the second housing  310 , and a female connector  330  electrically connected to an output signal line of the FM transmission board  320 . The FM transmission board  320  has a transmission circuit that modulates an audio signal output from the portable Karaoke system into a predetermined FM frequency and transmits the modulated signal to an external radio through the antenna wire  102 . 
     The female connector  330  is set on one side of the second housing  310  such that it can be connected to the male connector  180  for the FM transmission module, which is placed in the case  100 . The female connector  300  electrically connects the FM transmission circuit to the control circuit of the main body of the portable Karaoke system. The FM transmission module  300  further includes a pair of second guide protrusions  315  and  215 ′ that are respectively formed on both sides of the second housing  310  and slidably inserted into the second guide grooves  153  and  153 ′ of the main body of the portable Karaoke system, shown in  FIG. 3 . 
     Preferably, the FM transmission module  300  is smaller than the radio auxiliary microphone receiving module  200 . 
     Referring back to  FIG. 3 , the cover  101  is tightly combined with the case  100  such that the cover  101  covers a part of the case  100 , or the battery case  140  and the accommodation part  150 . 
     The antenna wire  102  is electrically connected to transmission/receiving antenna terminals (not shown) of the male connector  170  for the radio auxiliary microphone receiving module and the male connector  180  for the FM transmission module. Though it is preferable that the antenna wire  102  is formed in a ‘U’ shape in the protruded support  109  such that it can easily transmit and capture transmitted/received electric waves, the antenna wire  102  can be formed in a predetermined length at a predetermined place inside the case  100 . 
     The operation of the separate communication modules of the portable Karaoke system according to the present invention will now be explained. 
     When a plurality of users want to sing a song together using the portable Karaoke system of the present invention, the radio auxiliary microphone is used. The portable Karaoke system receives a radio signal transmitted from the radio auxiliary microphone via the radio auxiliary microphone receiving module  200  included therein. 
     Specifically, the cover  101  is separated from the case  100 , and then the radio auxiliary microphone receiving module  206  is vertically inserted into the accommodation part  150  such that the female connector  230  of the radio auxiliary microphone receiving module  200  is connected with the male connector  170  protruded from the bottom of the accommodation part  150 . 
     More specifically, the pair of guide protrusions  215  and  215 ′ formed on both sides of the first housing  210  of the radio auxiliary microphone receiving module  200  is slidably inserted into the first guide grooves  151  and  151 ′ of the accommodation part  150 . When the female connector  230  of the radio auxiliary microphone receiving module  200  meets the male connector  170  of the accommodation part  150 , a user pushes the first housing  210  of the radio auxiliary microphone receiving module  200  with a predetermined pressure such that the female connector  230  is combined with the male connector  170 . 
     When the radio auxiliary microphone is not used, the user separates the cover  101  from the case  100  and holds the housing  210  of the radio auxiliary microphone receiving module  200 , combined with the male connector  170  of the accommodation part  150 , by the fingers and lifts up the housing  210 . Then, the female connector  230  combined with the male connector  170  is separated from the male connector  170  and thus the radio auxiliary microphone receiving module  200  is completely removed from the accommodation part  150 . The user can easily carry or keep the radio auxiliary microphone receiving module  200  because it is small. 
     In the case that the user wants to radio-transmit an audio signal output from the portable Karaoke system according to the present invention with a predetermined FM frequency, he/she sets the FM transmission module  300  in the portable Karaoke system. The operation of inserting/separating the FM transmission module  300  into/from the accommodation part  150  of the case  100  is identical to the operation of inserting/separating the radio auxiliary microphone receiving module  200  into/from the accommodation part  150  so that an explanation thereon is omitted. 
       FIG. 6  is a perspective view of a portable Karaoke system having a battery housing structure according to another embodiment of the present invention. 
     Referring to  FIG. 6 , the portable Karaoke system includes a case  400  easily held by a user and a signal connecting device (not shown) for electrically connecting the case  400  to external devices (not shown). 
     A microphone net  410  is placed on the top of the case  400 , and a printed circuit board  420  including various electronic components for operating the portable Karaoke system is fitted into the case  400 . A key input unit  430  having a plurality of key buttons (not shown), electrically connected to the printed circuit board  420 , is provided on one side of the middle part of the case  400 . A battery case  440  for housing at least one battery for providing operation power to the portable Karaoke system is located on the other side of the middle part of the case  400 . 
     The battery case  440  is formed in a rectangular groove such that batteries are serially connected in the direction of length thereof. Contact terminals  450  and  450 ′ are respectively provided at both ends of the battery case  440  and electrically connected to the printed circuit board  420 . The contact terminals  450  and  450 ′ are respectively made of a metal plate and a spring. Preferably, the bottom face of the battery case  440  has a semicircular form in order to surround the outer face of the battery  500 . 
     Furthermore, the battery case  440  has a pair of hooks  460  and  460 ′ that are respectively fixed to both sidewalls  440   a  and  440   a ′ of the battery case  440 , opposite to each other. The hooks  460  and  460 ′ each have elasticity to prevent the battery  500  from being easily separated from the battery case  400  due to an external shock. In addition, semicircular recesses  470  and  470 ′ are respectively formed at the top edges of both sidewalls  440   a  and  440   a ′ of the battery case  440  to allow the user to easily remove the battery  500  from the battery case  440  by the fingers. 
     Reference numerals  480  and  490  respectively denote a cover and an input/output terminal. The cover  480  is tightly combined with the case  400  such that the cover covers a part of the case to protect it. The input/output terminal  490  is provided at the bottom of the case  400  and electrically connected to a main jack of the signal connecting device. 
     The operation of the battery housing structure of the portable Karaoke system according to the present invention will now be explained with reference to  FIGS. 7   a  and  7   b .  FIG. 7   a  illustrates an operation of inserting a battery into the battery case having hooks, included in the portable Karaoke system according to an embodiment of the present invention, and  FIG. 7   b  illustrates an operation of removing the battery from the battery case. 
     To fit the battery  500  into the battery case of the portable Karaoke system according to the present invention, the cover  480  is separated from the case  400  and then the battery  500  is fitted into the battery case  440 . When the outer face of the battery  500  reaches the hooks  460  and  460 ′ of the battery case  440 , the outer face of the battery  500  is mounted on the upper parts of the hooks  460  and  460 ′, which are bent toward the inside of the battery case at a predetermined angle. In this state, when the user pushes the battery  500 , the hooks  460  and  460 ′ are elastically wide open within a predetermined angle so that the outer face of the battery  500  slides on both sidewalls  440   a  and  440   a ′ of the battery case  440  to be fitted into the battery case  440 . Simultaneously, the hooks  460  and  460 ′ are returned to their original positions according to elasticity to apply a predetermined pressure to the outer face of the battery  500 . Thus, the battery  500  is not easily separated from the battery case even when an external shock is applied thereto. 
     When the battery  500  is replaced with a new one, as shown in  FIG. 7   b , the user separates the cover  480  from the case  400  and then holds the recesses  470   a  and  470   a ′ formed at the top edges of both sidewalls  440   a  and  440   a ′ of the battery case  440 . In this state, when the user lifts up the end of the battery  500 , the outer face of the battery  500  slides on both sidewalls  440   a  and  440   a ′ to be lifted upward. Here, the hooks  460  and  460 ′ are elastically wide open within a predetermined angle and thus the battery  500  is completely separated from the battery case  440 . Simultaneously, the hooks  460  and  460 ′ are returned to their original positions according to elasticity. 
       FIG. 8  illustrates combination of a general microphone net and the portable Karaoke system according to the present invention, and  FIG. 9  illustrates combination of a ball-type microphone net and the portable Karaoke system according to another embodiment of the present invention. 
     A microphone according to the present invention has a microphone main body  601 . The end  602  of the microphone main body  601 , which is combined with a microphone cartridge, has a stepped shape. A first gear  604  is formed at a thicker stepped portion  603  and a second gear  606  is formed at a thinner stepped portion  605 . 
     When the user wants to use a general microphone net  610  shown in  FIG. 8 , the user combines a combining ring  611  with the first gear  604  and then combines the microphone net  610  with the first gear  604  using a screw. When the user wants to use a ball-type microphone net  620  shown in  FIG. 9 , the user combines a fixing ring  621  with the second gear  606  including the outside of the first gear  604  and combines the ball-type microphone net  620  with the second gear  606  using a screw. 
     INDUSTRIAL APPLICABILITY 
     According to the present invention, a user can separately insert/separate the radio auxiliary microphone receiving module and the FM transmission module into/from the portable Karaoke system. Thus, the user can select and purchase only a required function module. Furthermore, because the function modules are small-sized, the user can easily carry and keep them. 
     Furthermore, the battery can be prevented from being easily separated from the battery case using a pair of hooks provided at both sidewalls of the battery case when the portable Karaoke system is used. In addition, the user can easily separate the battery from the battery case by the fingers using the recesses formed at the top edges of both sidewalls of the battery case when he/she wants to replace the battery with a new one. 
     Moreover, both of a general microphone net and a ball-type microphone net can be combined with the portable Karaoke system because the end of the microphone main body has a stepped shape and the first and second gears having different diameters are formed at stepped portions. 
     While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.