Abstract:
A small compact easy to handle device with disc-jockey functionality is proposed, comprising a housing, loudspeaker system output means ( 23 ) for providing a loud-speaker sound output to at least one loudspeaker system, a display ( 13 ), means for 5 providing at least a first channel or at least a second channel as the loudspeaker sound output said computing device being characterized in that the housing is dimensioned to be handheld by a user and that it comprises—selection means ( 13 ) for selecting one of the first and second channel  10 —control means ( 14, 18 ) comprising an input means for controlling at least one characteristic of the selected channel selected from the group of bend and play-back speed—cross-fading means ( 16 ) for cross-fading between the first and the second channel independently of the selected channel, said cross-fading means ena-  15  bling cross-fading by using one input means.

Description:
CROSS REFRERENCE TO RELATED APPLICATIONS 
     This application is a national stage application of International Application PCT/SE2006/050030, filed 15 Mar. 2006, designating the United States of America, which claims the benefit of 60/594,201 filed 18 Mar. 2005. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a hand-held computing device with built-in disc-jockey functionality and a method for using such a device. 
     BACKGROUND OF THE INVENTION 
     Disc-jockeys are often used at discotheques and other places of music/dance entertainment. Disc-jockeys (DJ) commonly use two audio tracks to eliminate the gaps between songs in order to increase the flow of music. More advanced control involves manipulating the playback speed of the audio tracks so that the transition between them can be seen as seamless, this is called beat mixing. On top of this a disc-jockey can use a whole variety of effects to manipulate the playback in order to increase the experience for the crowd. For example, the disc-jockey can manipulate the frequencies, add audio effects, manipulate the volume, and much more. 
     The DJ systems available today are expensive and bulky systems that very few people can afford. They normally consists of two audio playing devices capable of manipulating the playback speed, such as a DJ compact disc players or turntables; an audio mixer capable of mixing the output from the audio playing devices together; a pair of head phones, a power amplifier to amplify the output from the audio mixer; and a pair of loudspeakers. There is today also a wide range of computer programs that allow a user to mix digitally stored audio. What differentiates the computer programs from the traditional system is that the manipulation of the playback is done on the computer without any physical connection between the DJ and the tracks. However, in order to give the DJ physical control over the digitally stored audio, consoles with all the controls and inputs a DJ needs has been developed. 
     The basic control functions that are needed for DJ functionality include the following: 
     Crossfade: gradually changing from one channel to another channel by increasing the volume of one channel in at the same time as fading the other one out. 
     Pitch: changing the speed at which a track is played to adapt the speed of two tracks to each other. 
     Bend: temporarily changing the speed at which a track is played, to synchronize the beat of two tracks with each other to make a seamless transition between them. 
     Pause/play: to start and stop the playback of a channel. 
     Cue: stop playback and set the playback position to the cue point; a user set position in the track. 
     Traditional DJ equipment has two sets of all the application specific controls, including a pause/play and cue button, a bend control and a playback speed control for each channel and a cross fader for each audio output, that is, one for the lineout and one for the headphones. 
     Despite the recent advances of electronic components, the disc-jockey systems are still bulky and expensive to obtain. It is an object of the present invention to provide a disc-jockey system that is small and inexpensive while providing the same or better performance compared to traditional disc-jockey systems. 
     SUMMARY OF THE INVENTION 
     This object is achieved according to the invention by a computing device with built-in disc-jockey functionality, comprising a housing, loudspeaker system output means for providing a loudspeaker sound output to at least one loudspeaker system
     a display   means for providing at least a first channel or at least a second channel as the loud-speaker sound output   said computing device being characterized in that   the housing is dimensioned to be handheld by a user   and that it comprises
       selection means for selecting one of the first and second channel   control means comprising an input means for controlling at least one characteristic of the selected channel selected from the group of bend and play-back speed   cross-fading means for cross-fading between the first and the second channel independently of the selected channel, said cross-fading means enabling cross-fading by using one input means.   
       

     The object is also achieved by a method for using disc-jockey functionalities on a hand-held computing device, having a display, a control means, a cross-fade input device, and a loudspeaker system output device, said method comprising the steps of
         selecting one channel of a first and a second channel to be controlled by the control means,   activating the control means in a first or second direction to control at least one characteristic of at least a first track on at least a first channel.       

     By enabling control of both channels and of both the loudspeaker system output and the headphones output by means of the same control devices, a small hand-held device can be achieved. 
     In a preferred embodiment, the input means is a rotational input device on which at least one finger can be moved in a clockwise direction or a counter-clockwise direction for controlling the at least one characteristic. In this way the control function is not limited by the input device, for example by the finger reaching one end of the input device. 
     The selecting means may be arranged for selecting the channel by means of the display, by means of at lest one channel selection button or by any other conceivable method. 
     Preferably, the control means comprises a play-back speed control mode switch for enabling play-back speed control (often referred to as pitch control) using the input means. 
     The cross-fading means preferably enables cross-fading from one channel to the other by moving one finger from one side to another side to cross-fade from the first channel to the second channel 
     Normally, the computing device further comprises headphones output means for providing a headphones sound output to at least one headphone independently of the loudspeaker sound output, and a headphone control mode switch for enabling control of the headphones sound output by means of the control means and/or the cross-fade input device. This will enable the disc-jockey to listen to one track which is not played through the loudspeaker system, for example to adjust the playback speed to the track currently being played on the loudspeaker to make a seamless transition between two tracks. 
     The possibility to compress audio and moving picture files and the development of low cost flash memories have made it possible to build small, energy efficient audio players called Digital Audio Players (DAP). In the beginning they were all based on the so called Flash Memory technology and they could not store more than around 500 audio files. The development of very small hard disks then provided a capacity of storing several thousands of audio files. The technology has evolved further and the computing power of the energy efficient micro controllers has increased to the point that it now is possible to execute computing intensive tasks concurrently. The present invention makes use of this recent technical development to achieve a small DJ equipment that is easy to handle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic top view of a computing device according to the present invention 
         FIG. 2  is a schematic block diagram of the computing device according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     With reference to  FIG. 1 , the computing device  10  of the present invention has a housing  12  that is dimensioned to be hand-held by a user such as a disc-jockey. The computing device may be any suitable digital media player such as an MP3-player. It should be understood that the device  10  could be used by any user and the disc-jockey is only to be seen as an illustrative example. 
     In general, the device  10  has two channels, which makes it possible to play two audio tracks concurrently, so that the disc-jockey can almost seamlessly transfer the music the audience hears from one track, played on one channel, to the next track, played on the other channel. 
     The device is also able to produce two audio outputs, one headphones outlet  21  for listening through headphones  30  worn by the disc-jockey, and one loudspeaker system outlet  23  for the output to a loudspeaker system  32  for the audience. In this way, it is possible for the disc-jockey to listen to an audio track in headphones while another is playing in the loudspeaker system to make sure the new track that is coming up is in line with the music plan of the disc-jockey. 
     The device has a display  13  on a front side  15 , above an input device  14  of the housing. The input device  14  is preferably a rotational input device having a circular form that enables control by a rotational movement of the user&#39;s finger on the input device  14 . In the default mode the input device  14  is used to control the bend of the selected channel. A pitch control mode switch  18  is disposed at a side  20  of the housing  12 . When the pitch control mode switch  18  is pressed the input device  14  controls the playback speed of the selected channel. 
     The device  10  also comprises a cross-fader input device  16  used to control the cross-fading between the channels, a play/pause button  25  and a cue button  27 . The function of the control inputs  14 ,  16 ,  18 ,  25 ,  27  will be discussed in more detail below. By default, the control inputs on the device  10  are used to control the selected channel and the cross-fader input device  16  the loudspeaker system outlet. According to a preferred embodiment a first channel selection button for selecting the first channel and a second channel selection button for selecting the second channel are also included. Alternatively, only one channel selection button can be provided, in which case pressing the button always changes the channel to the one that is currently not selected. 
     To enable control of the headphone outlet, a headphone control mode switch button  22  is preferably disposed at a side  20  of the housing  12 . When the headphone control mode switch button  22  is pressed, the input device  14  will control the headphone volume and the cross-fade input will control the headphone cross-fade. When the headphone control mode switch button  22  is released the device will return to default mode in which the bend of the selected channel and the cross-fade of the loudspeaker system output can be controlled. From this mode, the pitch control mode can be reached by pressing the pitch control mode button  18 . 
     The play/pause button  25  and the cue button enable the playback to be controlled, that is, paused or cued. When a track is playing and the play/pause button  25  is pressed, the track will immediately start to loop around the current playback position which produces a short and repeated sound corresponding to the sound at the current playback position. Also, when a track is playing and the play/pause button is pressed, the input device  14  is used for scrolling the playback position of the track. When a track is paused and the play/pause button  25  is pressed, the track starts to play normally and the rotational input  14  is returned to its default usage. Also, when a track is paused and the cue button  27  is pressed the loop around the current play-back position is stopped, i.e. the repeated and short sound is silenced and the current playback position is set as the current cue point. If the cue button  27  has been pressed and the play/pause button  25  is pressed the tracks start to play normally from the set cue point. If the cue button is pressed when the track is playing, play-back is stopped and the playback position is set to the current cue point. 
     In the default mode the input device  14  is preferably used for bending up and bending down functions. In order to make the transition between two tracks seamless the disc-jockey can manipulate the speed of the playback of both tracks being played on the device. The playback speed can be ramped up (bent up) or slowed down (bent down) according to calculations carried out by the device  10  based on inputs from the disc-jockey. If the input device  14  is a rotational input device  14  the disc-jockey may rotate the rotational input  14  in a clockwise direction to bend up the track and in a counter-clockwise direction to bend down the track. The device  10  uses the rotational direction of the disc-jockey&#39;s fingers on the input device  14  and the rotated distance, speed and acceleration to calculate how to affect the playback of the track affected by the input  14 . For example, a more rapid change of the speed is accomplished by moving the finger very quickly on the input device  14 . After there is no additional input from the disc-jockey, the playback returns to the original speed according to calculations performed by the device. 
     The disc-jockey may press the pitch control mode switch button  18  to activate the playback speed manipulation functionality, often called pitch. That is, the playback speed can be changed by the disc-jockey permanently, that is, in such a way that it will not change until another input is recorded by the device, or until a new audio track is loaded which sets the playback speed to the default value for that track. 
     When the pitch control mode switch button  18  is pressed, the rotational input device  14  is used to control the playback speed of the tracks. By rotating the rotational input clockwise, the playback speed may be increased and by rotating the rotational input counter-clockwise the playback speed may be decreased. Also, when the pitch control mode switch button  18  is pressed, the display  13  displays a special screen showing the current playback speed value of the currently played audio track of the selected channel. When the disc-jockey changes the playback speed value the display  13  is updated with the new value to give feedback to the disc-jockey. The button  18  is preferably located on the upper left side of the housing  12  to make it easy for the disc-jockey to activate the playback speed manipulation functionality by using the left hand thumb or, in the case of a left-handed disc-jockey, with the fingers of the right hand. 
     To activate the cross-fade function for the lineout output, that is, the transition from the track of the first channel to the track of the second channel, the disc-jockey may use the cross-fade input  16  on the front side of the device located just below the input device  14 . By sliding the finger all the way to the left or right, the disc-jockey sets the audio output to be either the first channel or the second channel. This activates software that controls the mix of the output between the first channel and the second channel. Everything in between these extremes means that the audio output consists of a mix of the tracks of the two channels. When the cross-fade input  16  is activated or touched, the device displays a special screen on the display  13  showing the current position of the cross-fade of the lineout output. When the disc-jockey changes the values, the display is updated with the new values to give feedback to the disc-jockey. As stated above, in the default mode, the cross-fade input  16  controls the cross-fade on the loudspeaker system outlet  23 . When the headphone control mode switch  22  is pressed, the cross-fade input  16  controls the cross-fade on the headphones outlet  21 . 
     When the headphone control mode switch button  22  is pressed, the display  13  displays a special screen showing the current headphone volume. The display  13  also shows the current position of the headphone cross-fade. When the disc-jockey changes the values, the display  13  is updated with the new values to give feedback to the disc-jockey. The button  22  is preferably located on the upper left side of the housing  12  to make it easy for the disc-jockey to activate it using the left-hand thumb or, in the case of a left-handed person, with the fingers of the right hand. 
     Thus, in a preferred embodiment, all functions of the device  10  can be controlled using one hand. 
     In practice, the disc-jockey may start a track on the first channel that goes out to the loudspeaker system  32 , then start another track on the second channel, and then press and hold the headphone control mode switch button  22  so that the cross-fade input is used to change the headphone cross-fade from the first channel to the second channel. The disc-jockey is then listening to a second track, that is going to be played after the first track which is currently played through the loudspeaker. Also, when the headphone control mode switch button  22  is activated the rotational input device  14  will control the headphone volume so that the disc-jockey can set the headphone volume to an appropriate volume. The disc-jockey can then temporarily adjust the phase of the beat rate of the second track the disc-jockey is hearing in the headphones to match the phase of the beat rate of the first track by bending up or bending down the beat rate of the second track so that the transition from the beat rate of the first track can be seamlessly transformed into the beat rate of the second track. As indicated above, this may be done by touching the input device  14  and moving the finger in the clockwise direction to bend up or in the counter-clockwise direction to bend down. 
     In this way the phase of the beat rate of the second track is synchronized with the phase of the beat rate of the first track to prevent the beat rate of the first track and the beat rate of the second track to be too far away from each other as the second track is cross-faded in and the first track is cross-faded out. The synchronization of the beat rates is preferably done over the headphones so the audience does not hear the bending up or down of the second track. The speed of the finger determines how much the beat rate is temporarily increased or decreased. 
     The disc-jockey can also change the beat rate of the second track permanently, to match the beat rate of the first track better. As stated above, this is done using the input device  14  while pressing the pitch control mode switch button  18 . In other words, the disc-jockey can increase or decrease the beat rate of the second track to match the beat rate of the first track to make the transition more seamless and so that the audience does not have to change the dancing rhythm when the second track is being cross-faded into the loudspeaker system. 
     A channel must be selected in order to perform playback speed manipulation or bend on a track. This is preferably done in a graphical user interface displayed on the display  13 , which enables the disc-jockey to switch between the first channel and the second channel by scrolling and selecting the desired channel. Whenever the disc-jockey switches from one channel to another channel, the default of the device  14  is the bend function. The disc-jockey must press and hold the pitch control mode switch button  18  to switch the device  14  from the bend mode to the playback speed manipulation mode. As long as the disc-jockey has activated the first channel the graphical user interface displays information that relates to the first channel even if the disc-jockey uses the cross-fade device to change to the second track on the second channel. This means that the cross-fade device  16  can be used to switch the tracks regardless of whether the graphical user interface is displaying information about the first or the second channel. When a track is to be selected, the function of the rotational input device  14  is transformed to provide a scroll function so that the disc-jockey can locate and retrieve tracks from the hard disc or any other suitable memory or storage medium while the device  10  is in the first or second channel mode. 
     While the audience is listening to the first track on the first channel, the disc-jockey can activate the second channel on the graphical user interface on the display  13  to locate a suitable track on the hard drive or any other storage medium of the device  10  and then perform the required bend and playback speed manipulation functions as described above. 
     Often, the disc-jockey uses both the bend and playback speed manipulation functions to synchronize two tracks perfectly prior to making the transition from the first track to the second track on the loudspeaker system. It may be possible to display the beat rate for both tracks to make it easier for the disc-jockey to match the beat rate of the two tracks. 
       FIG. 2  is a logical block diagram of a disc-jockey device according to the invention. As stated above, the functions of the DJ device are implemented in software stored in the device and controlled by means of the control input devices  14 ,  16 ,  18 ,  22 ,  25  and  27 . 
     The device comprises a central processor unit CPU  31  comprising means for controlling the functions of the device. In particular, the CPU  31  comprises display control functions  33  for controlling the display and output mixing functions  35  for controlling the output to the loudspeaker system outlet  23  and the headphones outlet  21 . 
     The music tracks that are to be played are stored in a persistent memory unit  37 , such as a hard disk or a memory chip or any other appropriate storage means, which is connected to the CPU. The programs used by the various units of the CPU are also stored in the persistent memory unit  37 . An audio data decompression unit  39  in the CPU  31  receives the music files to be played from the memory unit  37 , decompresses them and forwards to a playback speed control unit  41 , usually through storage in a Random Access Memory (RAM)  42 . After the playback speed control unit  41  the music file is temporarily stored in RAM  42  again, and are equalized in an audio equalization and volume unit  43  from which it is forwarded to an audio loop processing unit  45  and then through the output mixing unit  25 . The units  39 ,  41 ,  43 ,  45  and  35  are known per se. 
     A user input processing unit  47  receives input from the input buttons  18 ,  22 ,  35 ,  37 , from the input device  14  and from the cross-fader  16 . If channel selection buttons are available, the user input processing unit  47  receives user input from them as well. 
     The user input processing unit in turn controls the following control units in dependence of the user input:
         1. playback speed control.   2. audio equalisation and volume,   3. audio loop processing,   4. output mixing       

     Further, an accessory management unit  49  may be arranged to handle connections to other devices, such as a USB connection  51 . 
     The Random Access Memory (RAM)  42  is provided for temporary storage of variables, music files that are currently being played, and other information that require quick access. 
     Preferably, the device is powered from a rechargeable battery  53 . Alternatively or in addition to this, power may be supplied from another type of battery, or from the mains. 
     The device may also be adapted to wireless communication so that the disc-jockey can even be among the dancing audience and participate in the dancing while manipulating the various tracks on the device  10 . 
     The device  10  may also be provided with a suitable digital connection  34 , such as on the back or any other suitable place, to enable the device to be connected to computers, accessories and other digital equipment for the exchange of data. 
     To make the device  10  stable a layer of a material having high friction may be applied to at least an area of the back of the device, so that it will not be prone to move when lying on a smooth surface. 
     While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the scope of the claims.