Patent Publication Number: US-2012027224-A1

Title: Acoustic System for Slide-Type Mobile Device

Description:
BACKGROUND 
     The present invention relates generally to sound systems for mobile devices and, more particularly, to a sound system for a slide-type mobile device having two or more relatively moveable housing sections. 
     Mobile devices, such as mobile phones, may be designed with a variety of form factors depending on functional or aesthetic considerations. For example, a flip or clam-shell type phone comprises two or more sections that are connected by hinges, allowing the phone to fold when the phone is not in use. A slider phone typically comprises two or more housing sections that slide relative to each other. A swivel phone typically comprises two or more housing sections that swivel or pivot about a central axis. 
     In the case of a slider phone, the top section of the housing typically includes a display, one or more input controls, and a speaker for outputting audio during voice calls. Typically, there is a separate loudspeaker disposed in the bottom section for playing back ring tones and other multimedia files. The speaker for voice calls takes up valuable and limited space within the top section of the housing and limits design flexibility. Therefore, it would be beneficial to eliminate the requirement of a separate speaker in the top section for voice calls. 
     SUMMARY 
     The present invention relates to sound systems for slide-type mobile devices, such as a mobile phone, having two or more sections that slide relative to one another. The mobile device includes a first speaker for outputting speech or voice during voice communications. An acoustic port extends from the speaker in the bottom section and through the top section to project sound from the top side of the mobile device. A first acoustic channel in the bottom section of the housing conveys sound from the speaker to the top surface of the bottom section. A second acoustic channel extends from the bottom to the top surface of the top section to convey sound when the top section is in the closed position. In some embodiments, the voice speaker may also be used for playing ring tones and multimedia files, thus eliminating the need for two separate speakers. 
     According to another aspect of the invention, an audio processing circuit is provided to compensate for differences in the acoustic port configuration when the top section of the phone is in the open and closed positions. A sensor detects the position of the top section relative to the bottom section. Depending on the position of the top section, the audio processing circuit can vary the gain and/or frequency contact of the audio signal, depending on whether the top section is in an open or closed position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of an exemplary mobile device in a closed position. 
         FIG. 2  is a top view of an exemplary mobile device in an open position. 
         FIG. 3  is a section view of an exemplary mobile device in a closed position. 
         FIG. 4  is a functional block diagram illustrating the main components of the mobile device. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, a mobile device according to one exemplary embodiment of the present invention is shown therein and indicated generally by the numeral  100 . The illustrated embodiment of the mobile device comprises a mobile phone. Those skilled in the art will appreciate that the mobile device may also comprise other devices, such as a tablet, laptop computer, audio player, or other mobile device. 
     The mobile device  100  comprises a housing  102  having first and second housing sections  104 ,  106 . The first housing section  104 , referred to herein as the top section, includes an electronic display  120  and control buttons  122 . The electronic display  120  preferably comprises a touchscreen display, but may comprise a conventional liquid crystal display or other types of electronic displays. The second housing section  106 , referred to herein as the bottom section, includes a text entry keypad  126 . 
     The top and bottom sections  104 ,  106  of the housing  102  slide relative to one another between closed ( FIG. 1 ) and open ( FIG. 2 ) positions. In the closed position, the keypad  126  is hidden from view, while in the open position the keypad  126  is accessible to the user. A seal or gasket  108  may be provided between the housing sections  104 ,  106 . 
       FIG. 3  is a cross-section of the mobile device  100  with the top and bottom sections  104 ,  106  in the closed position. As seen in  FIG. 3 , the mobile device  100  includes a primary speaker  130  and a secondary speaker  132  disposed within the bottom section  106  of the housing  102 . The primary speaker  130  is oriented to project sound toward the front side of the mobile device  100 , while the secondary speaker  132  is oriented to project sound toward the back side of the mobile device  100 . An acoustic port  134  extends from the primary speaker  132  through the top section  104  of the housing  102 . The acoustic port  134  comprises a first acoustic channel  136  in the bottom section  106  of the housing  102 , and a second acoustic channel  138  in the top section  104  of the housing  102 . When the top section  104  of the housing  102  is in the closed position, the acoustic channels  136 ,  138  are aligned. In this position, sound generated by the speaker  132  is directed by the first and second acoustic channels  136 ,  138  to the front side of the mobile device  100 . When the top section  104  is moved to an open position, the sound generated by speaker  132  is transmitted through the first acoustic channel  136  and projects forward from the bottom section  106  of the housing  102 . In some embodiments, the top section  104  may include a third acoustic channel (not shown) that aligns with the first acoustic channel  136  in the open position. A seal or gasket  108  between the housing sections  104 ,  106  and extending around the channel openings may be provided to prevent sound from leaking out of gaps between the housing sections  104 , 106 . 
     A second acoustic port  140  is formed in the bottom section  106  of the housing  102  to project sound generated by the secondary speaker  132 . The secondary speaker  132  may be used, for example, to play back multimedia sounds such as ringtones or music. In some embodiments of the invention, the primary speaker  130  may also be used to play back multimedia sounds. If speaker  130  is used for playback of multimedia sounds, speaker  132  may be eliminated so that the mobile device  100  has a single speaker. 
       FIG. 4  illustrates an exemplary audio circuit  150  for the mobile device  100 . The audio circuit  150  comprises an audio processing circuit  152 , speakers  130 ,  132 , and microphone  154 . Microphone  154  converts audible sounds into electrical signals for input to the audio processing circuit  152 . Speakers  132 ,  134  convert audio signals output by the audio processing circuit  152  into audible sounds that can be heard by the user of the mobile device  100 . 
     The audio processing circuit  152  may receive input from a position sensor  160  and counter  162 . The position sensor  160  detects the relative positions of the top and bottom sections  104 ,  106  of the housing  102  and generates a position signal indicating whether the top section  106  is in the open or closed position. Based on the position of the top section  104  relative to the bottom section  106 , the audio processing circuit  152  may vary a characteristic of the audio signal that is output to the speaker  132  to compensate for variation in the acoustic port configuration. For example, the audio processing circuit  152  may vary the gain or frequency content of the audio signal, depending on whether the top section  104  is in the open or closed position. Different gains may be applied to different frequencies within the audio signal. 
     The counter  162  counts the number of times the top section  104  is moved between the open and closed positions. Movement of the top section  104  between open and closed positions will wear the seal  108  between the top and bottom sections  104 ,  106 , resulting in some leakage of sound from the gap between the housing sections. The audio processing circuit  152  may vary a characteristic of the audio signal output to speaker  132  to compensate for the wear of the seal. As one example, the audio processing circuit  152  may vary the gain or frequency content of audio signal, depending on the count from the counter  162 . 
     The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.