Abstract:
An audio system for multimedia computer systems and method for use are provided including an audio module having speakers, a microphone and associated circuitry. The audio module is adapted to be interposed between a monitor and a monitor pedestal such that the audio module swivels and tilts in concert with the monitor. The circuitry is adapted to drive the audio module speakers and to drive only one speaker and the microphone in a speaker phone mode.

Description:
This is a continuation of application Ser. No. 08/303,412, filed Sep. 9, 1994 now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to an audio system for a personal computer. 
     BACKGROUND OF THE INVENTION 
     A recent trend in personal computing has been toward the multimedia computer, which provides high quality audio as well as video output. Such systems have typically included a pair of add-on speakers which are placed near the monitor and plugged into a sound board in the computer. In some cases, a microphone is also placed near the monitor to provide an input to the sound board. However, in such systems, the mobility of the speakers and the microphone relative to one another tends to frustrate attempts at echo cancellation, resulting in undesirable feedback. 
     As noted, upgrading an existing computing system to multimedia functionality typically requires a pair of add-on speakers and a plug-in sound board. However, use of add-on speakers consumes valuable desktop space and requires separate re-orientation of the monitor and speakers as the user changes position. Typically, over-the-counter multimedia computer systems have speakers that are built into the computer housing or built into the monitor or, in systems such as those currently marketed by IBM, built into the pedestal of the monitor. However, the audio components of these over-the-counter systems are not readily upgraded or replaced without replacing expensive associated equipment, such as a monitor. 
     SUMMARY OF THE INVENTION 
     In one aspect of the invention, an audio circuit for a multimedia computer is provided that comprises two speakers and a microphone. A driver is provided for driving the two speakers. A controller is connected to the driver for causing only one of the speakers to be driven while the computer is operating in a mode in which feedback through the microphone would otherwise occur. 
     In another aspect of the invention, an audio module for a computer monitor is provided which comprises a housing containing two speakers and a microphone which are mounted in fixed positions in the housing. The housing also contains circuitry having ports for receiving audio signals for the speakers and for delivering audio signals from the microphone. 
     In yet another aspect of the invention, a multimedia computer system is provided which includes a monitor and an audio module which is affixed to the monitor. The audio module contains a first speaker, a second speaker, and a microphone mounted in the audio module in a fixed relationship. The computer also contains a sound board comprising a means for driving both the first speaker and the second speaker when the system is in a speaker mode and for driving only one of the speakers when the system is in a speaker phone mode. The computer further comprises a means for applying a signal generated by the microphone to the sound board. 
     The invention also relates to a method of controlling an audio circuit of a multimedia computer which contains a first speaker, a second speaker, and a microphone. The method includes the step of controlling an audio circuit by supplying drive signals to both the first speaker and the second speaker when the audio circuit is in. a speaker mode. The method also includes the step of driving only one of the the speakers and receiving signals from the microphone when the audio circuit is in a speaker phone mode. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of video and audio interface components of a multimedia computer; 
     FIG. 2 is a block diagram of an audio system for a multimedia computer; 
     FIG. 3 is a schematic diagram of an audio circuit for a multimedia computer; 
     FIG. 4 is a side view of video and audio interface components of a multimedia computer; 
     FIG. 5 is an exploded perspective view of a multimedia monitor; 
     FIGS. 6 a  and  6   b  are front and side views, respectively, of a multimedia monitor; 
     FIG. 7 is a side view, partially in cross-section of a speaker portion of an audio module; 
     FIG. 8 is a front, right side, top perspective view of an audio module showing our new design as it is attached to a monitor, the monitor being shown for illustrative purposes only and not forming a part of the claimed design; 
     FIG. 9 is a front elevational view of the audio module shown in FIG. 8, the monitor being shown for illustrative purposes only and not forming a part of the claimed design; 
     FIG. 10 is a front, right side, top perspective view of the audio module showing our new design; 
     FIG. 11 is a front elevational view thereof; 
     FIG. 12 is a left side elevational view thereof; 
     FIG. 13 is a right side elevational view thereof; 
     FIG. 14 is a top plan view thereof; 
     FIG. 15 is a bottom plan view thereof; and 
     FIG. 16 is a rear elevational view thereof. 
    
    
     DETAILED DESCRIPTION 
     Embodiments of the invention will now be described in detail with reference to the accompanying figures. 
     In FIG. 1, a pedestal  1  supports an essentially U-shaped audio module  3 . A video monitor  5  is disposed and held within the opening defined by the U-shaped audio module  3 . The audio module  3  comprises a right (when facing away from the monitor) speaker  7  housed in a speaker portion  110 , a left speaker  9  housed in a speaker portion  108 , and a microphone  11  disposed adjacent one of the speakers, e.g., the right speaker  7 . The audio module  3  is provided with a headphone jack  13  that allows the user to bypass the speakers by plugging in a standard pair of audio headphones. A speaker mute button  15  is also provided to allow the user to temporarily disable the speakers. 
     The audio module  3  provides a mounting structure that causes the left and right speakers and the microphone to be oriented along the viewing axis  17  (FIGS. 4 and 5) of the monitor and maintains a fixed orientation among the speakers and the microphone. Thus, if the monitor is moved up or down (tilted) or is swiveled on the pedestal, the relative orientation of the speakers, the microphone, and the monitor will remain the same. 
     In FIG. 2, all of the components of the multimedia system are disposed within the audio module  3  except for personal computer  21  and sound board  23 . The sound board  23  is connected to the audio module  3  via a standard connector  25 , which may comprise a ribbon connector, a cable, or any other conventional connector. 
     The audio module  3  is provided with a +5 volt power supply by the computer  21  via the connector  25 , or from an external input or internal supply. The sound board  23  generates an on/off control  27 , which is applied to a switch  37  via the connector  25 . On/off control  27  controls switch  37  to allow software control of the on/off state of audio module  3 . On/off LED  38  is illuminated when switch  37  is on to indicate active status of the audio module. 
     Sound board  23  also generates left and right audio inputs  29  and  31 , respectively, which are supplied to the audio module via the connector  25 . The output  33  from microphone  11 , discussed in more detail below, is supplied back to the sound board via the connector  25 . 
     An external audio input  35  is provided on the audio module to allow connection of an external audio signal source such as a CD player. The left and right channels from the external audio input  35  and the left and right audio inputs  29 ,  31  generated by the sound board are applied to a sum circuit  39 . Sum circuit  39  combines these inputs into a single left and a single right channel, which are applied to speaker amp  41 . Optionally, the left and right channels from the external audio input  35  may also be fed back to the sound board  23  via connector  25  (see FIG.  3 ). 
     Speaker amp  41  receives +5 volt power from switch  37  when the audio module is active. Speaker amp  41  amplifies the left and right audio signals to an appropriate level to drive right speaker  7  and left speaker  9 . Headphone jack  13  is supplied with audio signals directly from the sound board  23  via headphone left (HPL) line  59  and headphone right (HPR) line  61 . Headphone jack  13  is equipped with a conventional mechanical switch which disconnects the left and right speakers in the event a headphone is plugged into the jack. Optionally, a headphone detect line (shown in FIG. 3) may be provided to detect the presence of a headphone and supply this information to sound board  23  via connector  25 . 
     Sound board  23  has the ability to drive speakers  7  and  9  according to software being run by computer  21 . The speakers  7  and  9  can be driven together or individually. Thus, computer  21  has complete and active control of the output of the speakers  7  and  9 . 
     Speaker mute button  15 , when actuated by the user, disables the speaker amp  41  so as to bypass software control and turn off the speakers. Re-actuation of button  15  turns the speakers back on. 
     The output of microphone  11  is applied to mic preamp  55 , which generates mic out signal  33 . Mic preamp  33  receives +5 volt power from switch  37  when the audio module is active. As noted above, mic out signal  33  is applied to the sound board  23  via the connector  25 . 
     In the interest of expense and/or simplicity, the audio module  3  can be made as a completely passive device by omitting amplifier  41  and mic preamp  55 . In this event, the +5 volts applied to the audio module, the switch  37 , and on/off control  27  also become unnecessary. While the ability to drive the speakers is limited in this embodiment, this embodiment has the advantage that only standard left and right audio inputs and a standard mic output are necessary, allowing use of the audio module with sound boards not specifically designed for this application. 
     In operation, when the multimedia system of the invention is in “speaker mode”, the speakers  7 ,  9  are driven by sound board  23  under software control by computer  21 . The sound output may comprise music from a CD-ROM associated with the computer  21 , or audio accompaniments to a program being run on the computer. Thus, the audio module can function as a “stereo” to provide music, or can function to provide high fidelity audio accompanying a computer program. 
     Additionally, in another mode, it may be desirable to use the audio module as a speaker phone. This allows the multimedia computer to perform yet another significant office function and makes the freestanding speaker phone obsolete. Because the orientation of the sound axes of the speakers and the microphone mounted in the audio module are parallel to the line of sight  17  of the monitor, the user can operate the computer, possibly on line with another user via a modem, while simultaneously communicating verbally via the audio module. 
     Because the relative placement of the left and right speakers and the microphone is fixed, echo cancellation techniques can be very effective in eliminating feedback of the remote speaker&#39;s voice, thus allowing the audio module to operate as a full-duplex speaker phone. To further eliminate feedback, when the computer is in “speaker phone mode,” sound board  23  supplies the voice line from the remote user on only the left speaker  9 , i.e., the speaker remote from the microphone  11 . The right speaker  7  adjacent the microphone is not driven in speaker phone mode. Thus, the possibility of feedback is virtually eliminated, and effective full-duplex speaker phone operation is made possible. 
     A detailed schematic diagram according to an embodiment of the invention is shown in FIG.  3 . In this embodiment, the +5 volt supply is shown as a separate input  51  on the audio module  3 . This +5 volt supply is applied directly to switch  37 , which is constructed in a conventional manner. 
     In this embodiment, connector  25  includes a standard  20  pin DIN connector  53  which supplies, among others, the on/off control  27  to the switch  37 . 
     The left and right audio inputs  29 ,  31  and the left and right channels from the external audio input  35  are applied to sum circuit  39 . Sum circuit  39  is made up of a first op amp  39 A for the left channel and a second op amp  39 B for the right channel, as well as capacitors and resistors arranged in a conventional manner to provide proper bias levels. The left and right channels of the external audio input  35  are additionally fed back through the  20  pin DIN connector  53  via “L-out” and “R-out” lines  55 ,  57 , respectively, to allow monitoring of these signals by the sound board  23 . The outputs of the op amps  39 A,  39 B of sum circuit  39  are applied to amplifier  41 , which in turn drives left and right speakers  7 ,  9 . Amplifier  41  may be any appropriate commercially available IC amplifier. 
     Headphone jack  13  is driven directly by headphone left (HPL) and headphone right (HPR) lines  59 ,  61 , via the  20  pin DIN connector. The amplifier  41  is bypassed in the headphone circuit because the typical output of an amplifier designed for use with high fidelity speakers would be undesirably high for use with headphones. 
     As discussed above, speaker mute button  15  is provided on the audio module which allows a hardware disconnect of the speakers  7 ,  9 . This mute button is useful for situations where a temporary disabling of software control of the speakers is desired. Sense line  65  is provided which detects the presence of a headphone and supplies this information to the sound board  23  via the  20  pin DIN connector  53 . 
     Circuits  67 ,  69 , and  71  perform signal conditioning and/or bias level adjustment functions in a manner well known to the skilled artisan. 
     As shown in FIGS. 1 and 4, a base portion  106  of the audio module  3  is positioned between the video monitor  5  and the pedestal  1 . This permits the video monitor  5  and the audio module  3  to form an integrated multimedia system. Pedestal  1  typically is a separate structure from video monitor  5 . The practice has developed in the computer industry of a given monitor manufacturer producing relatively few styles of pedestals for use with many different monitors. For example, a single pedestal  1  may be used with different models of 14-inch or 15-inch monitors produced by the manufacturer. As will be discussed in more detail below, the attachment of pedestal  1  to video monitor  5  typically involves tongue-and-groove or snap-lock engagements at a mechanical interface. Such pedestals are removable from and reattachable to the video monitor  5  at this interface. 
     One aspect of the invention allows a user to take an existing video monitor  5 , detach the pedestal  1  from the video monitor  5 , physically attach an audio module  3  to the bottom of the video monitor  5  and then attach the pedestal  1  to the bottom of the audio module  3 . This sequence is depicted in exploded view in FIG.  5 . FIG. 5 illustrates the pedestal  1  having a base  100  and a rocker  102 . The rocker  102  is coupled to the pedestal base  100  such that the rocker  102  is capable of tilting up and down and swiveling from side to side. Not shown in FIG. 5 are pedestal-to-monitor engaging means  104 . Audio module  3  is shown disposed between pedestal  1  and the video monitor  5 . The audio module  3  is shown to be comprised of a base portion  106  and two speaker portions  108  and  110 . The base portion  106  of audio module  3  has a first or lower surface  112  and a second or upper surface  114 . The first surface  112  has pedestal attaching means  116  which correspond substantially to the pedestal attaching means  118  located on video monitor  5 . Pedestal attaching means  116  and  118  may take the form of grooves or tongues for tongue-in-groove engagement, recesses or protuberances for snap and lock engagement or guides and bosses for screw engagement. There are numerous and different ways and means of attaching the pedestal  1  to the video monitor  5  and thus there are numerous and different ways and means of attaching the pedestal  1  to the audio module  3  and the audio module  3  to the monitor  5 . The second surface  114  of audio module  3  is formed to follow the contours of the video monitor  5  and thereby closely mate audio module  3  to video monitor  5 . Second surface  114  includes monitor engaging means  120  (not shown) that are substantially identical to the monitor engaging means  104  on the pedestal  1 . Monitor engaging means  120  engage pedestal attachment means  118  in video monitor  5 . 
     Thus, an aspect of the invention allows a conventional video monitor  5  to be upgraded to multimedia functionality by installing an audio module  3  between the video monitor  5  and the monitor pedestal  1 . The invention utilizes the existing attachment scheme of the pedestal  1  and the video monitor  5  and therefore typically does not require structural modification of the monitor  5  or pedestal  1 . Further, the invention permits the video monitor  5  and audio module  3  to tilt and swivel in concert about the pedestal  1 . This “line of sight” orientation is significant, as discussed above, for speaker phone functionality and for general multimedia functionality. Further, the present invention is not tied to the computer housing, which allows the user to place the computer housing out of the way to conserve valuable desktop space. 
     FIGS. 6 a  and  6   b  illustrate other aspects of the invention. FIG. 6 a  illustrates audio module  3  having speaker portions  122  and  124  that are substantially coplanar with base portion  126 . As shown in FIG. 6 b , speaker portions  122  and  124  are pivotably mounted to the base portion  126  of audio module  3 . This mounting arrangement allows the user to adjust the orientation of speaker portion  122  and  124  to achieve the acoustics desired by the user while retaining the feature that when the monitor is reoriented so are the speakers. 
     It will be appreciated that users often relocate the video monitor  5  to different offices, different desks or different positions on a desk. Because monitors typically can weigh upwards of 30 pounds, it is to be expected that users likely will grab onto speakers portions  122  and  124  (or speakers portions  108  and  110  of FIG. 5) when moving and lifting the monitor  5 . Thus, audio module  3  should be structurally sufficient to permit such lifting and moving by the speaker portions or such lifting and moving should be strongly discouraged. Referring back to FIG. 4, left speaker portion  108  is shown to have a guide  130  that engages an existing monitor screw hole  132  in the monitor S. The attachment of guide  130  and screw hole  132  imparts structural integrity to the audio module  3 . 
     FIG. 7 illustrates a partial cross-sectional view of a speaker portion of the invention such as speaker portion  108 . Speaker portion  108  (and audio module  3 ), can be fabricated from conventional injection mold plastics as are commonly used in the computer industry. Speaker portion  108  is shown to house speaker  134 . Speaker  134  is preferably a self-contained speaker unit comprising a full range speaker element (not shown) or individual speaker components and frequency cross-over networks (also not shown). The speaker unit  134  preferred for the invention is manufactured by Panasonic and contains a full range speaker element in a ported enclosure. Speaker portion  108  is designed for speaker  134  to be placed within speaker portion  108  such that the full range speaker element substantially aligns with port  136  and the speaker port substantially aligns with port  138 . A substantially acoustically transparent grill  140  protects speaker  134 . The invention allows a user to replace speaker  134  when the user desires to upgrade the audio module  3  or to repair the audio module  3 . Also shown in FIG. 7 is the fixed location of microphone  11  in speaker portion  108 . 
     The base portion  106  of the audio module  3  shown in FIG. 7 has a plurality of tongues  142  protruding from and forming a part of the second or upper surface  114 . These monitor engaging means  120  engage with corresponding grooves (pedestal attachment means  118 ) in video monitor  5 . The base portion  106  also includes a plurality of grooves  144  on and a part of the first or lower surface of the base portion  112 . These grooves (pedestal attaching means  116 ) engage corresponding tongues (pedestal engaging means  104 ) on the pedestal  1 . 
     Preferred embodiments of the invention have been shown and described in detail. However, the invention is not so limited, but rather is limited only by the scope of the claims.