Abstract:
A single chamber headphone apparatus and earcup design is provided which enhances wearer comfort, reduces headphone weight, facilitates ease of use, maintenance and operation by providing an improved internal chamber and battery cap configuration. Sound quality is improved by eliminating acoustic problems associated with two-chamber headset designs. A volume balance control is also provided.

Description:
PRIORITY TO RELATED APPLICATIONS 
       [0001]    This application is the National Stage of International Application No. PCT/US08/86701 filed on Dec. 12, 2008, which claims the benefit of U.S. Provisional Application No. 61/012,974, filed Dec. 12, 2007, the entire contents of each which are incorporated herein by reference 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to headphones or headsets generally, and, more particularly, to an improved headphone apparatus and earcup design which enhances wearer comfort, reduces headphone weight, facilitates ease of use, maintenance and operation by providing an improved internal chamber and battery cap configuration. The headphone apparatus of the present invention improves sound quality by eliminating acoustic problems associated with two-chamber headset designs. A volume balance control is also provided. 
       BACKGROUND OF THE INVENTION 
       [0003]    Recent advances in sound transmission technology have lead to the development of new headphones or headsets for use in telecommunications and entertainment applications in both external environments, such as military field operations, and internal environments, such as home use for listening to music and/or radio and television broadcasts. Headsets normally include one or a pair of earcups which fit over the outer ear and which are held in place by hand or by means of a head band which extends over the top of or behind the wearer&#39;s head. In addition to sound quality, wearer comfort is of primary concern to the user, particularly if the headphones are to be worn over an extended time period. 
         [0004]    Headphone designs intended to improve both headphone sound quality and wearer comfort are disclosed in U.S. Pat. No. 4,455,675 issued to Bose et al, Jun. 19, 1984 and in U.S. Pat. No. 4,644,581 issued to Sapiejewski, Feb. 17, 1987. The headphones which are the subject of those disclosures include headphone cavities and electroacoustical transducers such as pressure-sensitive microphones positioned within the cavities respectively for providing signals which correspond to the sum of external noise and the sound produced by the headphone driver in each cavity. These designs include internal circuitry which reduces noise and distortion and improves the quality of the sound output to the ear and a cushion in contact with the ear to enhance wearer comfort. 
         [0005]    More recently, U.S. Pat. No. 4,922,542 issued to Sapiejewski, May 1, 1990 discloses a headphone in which each earcup includes a baffle which supports a driver for converting an electrical input signal into an acoustical output signal to the ear. The baffle defines an inner and an outer cavity, the outer cavity being positioned adjacent the wearers ear and encompassed by a cushion surrounding the outer ear and sealing the outer cavity from the surrounding external environment. Similarly, U.S. Pat. No. 5,181,252 issued to Sapiejewski et al., Jan. 19, 1993 discloses a headphone having a high compliance driver mounted on a baffle which divides the headphone earcup into two chambers, each chamber having a preselected compliance which is individually matched to the compliances of the other chamber and the driver respectively to maximize the quality of the acoustical output. U.S. Pat. No. 7,412,070 issued to Kleinschmidt at al., Aug. 12, 2008 discloses a headphone having a pair of earcups, each earcup having a loudspeaker driver located off-center in an internal cavity. However, the designs of the &#39;542, the &#39;252 and the &#39;070 disclosures do not adequately address the problems associated with acoustic interference and cancellation phenomenon associated with multi-chamber headphone designs, nor do they address the problem of volume balance control. 
         [0006]    The headphone design of the present invention overcomes these and other problems by providing a new and novel headphone design which eliminates the internal acoustical compliance-related issues associated with a multi-chamber headphone earcup construction and a volume balance control feature which will permit the wearer to selectively psychoacoustically calibrate, adjust and balance the sound volume in each earcup. More specifically, the present invention provides a single chamber earcup having the microphone and driver mounted inside the earcup in such a manner that the baffle is eliminated, thereby permitting free flow of air throughout the entire cavity formed by the back of the earcup and the side of the wearers head. Means are provided to support the driver and the microphone at a predetermined location within the earcup that is sufficiently removed from the wearer&#39;s outer ear to prevent damage to the microphone which could result from contact with the pinna and during the process of putting on and/or removing the headphones, yet which is sufficiently close to the ear canal to maximize the quality of the sound delivered to the eardrum. An improved battery cover or cap is also provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a headset according to an embodiment of the present invention; 
           [0008]      FIG. 2  is a perspective view of a microphone and driver mounting apparatus according to an embodiment; 
           [0009]      FIG. 3  is a perspective view of a microphone and driver mounting apparatus according to another embodiment; 
           [0010]      FIG. 4  is a perspective view of a microphone and driver mounting apparatus according to yet another embodiment; 
           [0011]      FIG. 5  is a perspective view of a microphone and driver mounting apparatus according to still another embodiment; 
           [0012]      FIG. 6  is a plan view of a microphone and driver mounting apparatus according to another embodiment; 
           [0013]      FIG. 7  is a side cross-sectional view of the microphone and driver mounting apparatus of the embodiment of  FIG. 6 ; 
           [0014]      FIG. 8  is a perspective view of a free flow protective cover according to an embodiment; 
           [0015]      FIG. 9  is a front perspective view of a battery cap according to an embodiment; 
           [0016]      FIG. 10  is a rear perspective view of the battery cap of  FIG. 9 ; 
           [0017]      FIG. 11  is a rear plan view of the battery cap of  FIGS. 9 and 10 ; 
           [0018]      FIG. 12  is a plan view of a battery compartment according to an embodiment; 
           [0019]      FIG. 13  is an enlarged partial sectional view of a portion of the battery compartment of  FIG. 12 ; 
           [0020]      FIG. 14  is a front perspective view of a battery cap according to another embodiment; 
           [0021]      FIG. 15  is a rear perspective view of the battery cap of  FIG. 14 ; 
           [0022]      FIG. 16  is a side elevational view of a sound volume balance control in accordance with an embodiment; 
           [0023]      FIG. 17  is a top plan view of the sound volume balance control of  FIG. 16 ; 
           [0024]      FIG. 18  is a rear elevational view of the sound volume balance control of  FIGS. 16 and 17 ; and 
           [0025]      FIGS. 19 and 20  are front and rear perspective views of the sound volume balance control of  FIGS. 16-18 . 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0026]    Before proceeding with the detailed description, it should be noted that the present teaching is by way of example, not by limitation. The concepts presented herein are not limited to use or application with one specific type of headphone or earcup design. Thus, although the instrumentalities described herein are for the convenience of illustration and explanation, shown and described with respect to exemplary embodiments, the principles disclosed herein may be applied to other types and applications of headphone and earcup apparatus. 
         [0027]    Referring now to  FIG. 1 , a headphone or headset apparatus is illustrated in perspective and includes a pair of headphones (also known in the art as earphones)  102  and  104  adapted to fit over a users left and right outer ears (not shown). The earphones are pivotally connected to one another by an adjustable headband  105  adapted to fit over the top of a wearer&#39;s head, the headband having a wishbone-shaped yoke member  106 ,  107  secured at each end thereof for pivotally connecting the earphones to the headband. The headband comprises a pair of overlapping members  108 ,  109  which are slideably juxtaposed one on top of the other for adjustment to fit the wearer&#39;s head size. While in the embodiment shown, the headband is positioned over the top of the head, the headband alternatively could be of the behind-the-neck design without departing from the scope of the instant invention. 
         [0028]    Each headphone includes an earcup  110 ,  112  pivotally mounted to the yoke members  106 ,  107  respectively, each earcup also having a cushion  114 ,  116  secured circumferentially thereto and adapted to fit over the wearer&#39;s left and right outer ears for comfort purposes, particularly during extended periods of wear. Earcup  110  also includes a battery cap  118  detachably secured thereto to contain one or more batteries in a battery compartment (not shown) formed in the earcup outer shell. The earcups each form an internal chamber, one of which is shown at  120 , which is adapted to fit over the wearer&#39;s outer ear and which contains the electronics, circuitry, microphones, and at least one speaker, diaphram and associated driving member for operation of the headset and the transformation of electrical signals into acoustical signals for transmission to the left and right inner ear canals of the wearer. Typically, a protective membrane or screen  121  is disposed over the microphone to keep dirt and other foreign matter from being deposited in the chamber, which could be deleterious to the operation of the headset. 
         [0029]    A diaphragm and driver assembly  125  is illustrated generally in  FIG. 2  in accordance with one embodiment of the instant invention. The assembly includes a diaphragm  126  coupled to a driver  128  and means for mounting the assembly in the internal chamber of the earcup. In the embodiment of  FIG. 2 , the driver is secured by arm  129  to a frame  130  for mounting inside an earcup  110 ,  112  of  FIG. 1 . The frame  130  includes a generally circumferentially-shaped outer annular portion  132  adapted to be fitted into the earcup  110 ,  112 , an inner ring  134  to which the arm  129  and the driver assembly  125  are connected, and a plurality of spokes or arm members  136  disposed axially about the ring element and connected at a first end thereto. The spokes extend radially outwardly from the inner ring and are each connected at a second end to the outer annular portion  132  of the frame  130 , the entire assembly being mounted inside the earcup. Bushings  137  are selectively formed on several of the spokes  136  and positioned circumferentially around the ring  134  for receiving mounting screws to secure protective cover over the diaphragm, as will hereinafter be discussed in greater detail. 
         [0030]    The spaces  138  formed intermediate each spoke provide for the free flow of air and acoustic energy from the area in the chamber behind the diaphragm to the portion of the chamber positioned between the diaphragm and the outer ear. Hence, the acoustic problems associated having to match and balance the compliances of the speaker and of each of the inner and outer chambers formed by the baffles found in the prior art two-chamber headphones is eliminated, there being only a single chamber having a single compliance value in the exemplary headphone/earcup design of the present invention. 
         [0031]    In another embodiment of the present invention illustrated in  FIG. 3 , the assembly includes a diaphragm  126 ′ mounted to a driver  128 ′ which is secured by arm  129 ′ to a frame  130 ′ for mounting inside an earcup  110 ,  112  of  FIG. 1 . Similar in construction to the embodiment of  FIG. 2 , the frame  130  includes a generally circumferentially-shaped outer annular portion  132 ′ adapted to be fitted into the earcup  110 ,  112 , an inner ring  134 ′ to which the arm  129 ′ and the driver assembly  125 ′ are connected, and a plurality of spokes or arm members  136 ′ disposed axially about the ring element and connected at a first end thereto. In this embodiment, the spokes  136  are in the form of rigid, thin wires, much like bicycle spokes, which provide even greater spaces  138 ′ intermediate each spoke, thus enhancing the single chamber effect. 
         [0032]      FIG. 4  illustrates the embodiment of  FIG. 3  further including supporting grid or framework  140  which is disposed immediately adjacent to and behind the frame  130 ′ to provide additional structural support thereto. This additional support may be beneficial in holding the diaphragm  126 ′ and frame  130  in position as the headphones are either placed upon or removed from a wearer&#39;s head. 
         [0033]    Yet another embodiment of the present invention is shown in  FIG. 5  in which the frame  130 ″ supporting the diaphragm or driver assembly  126 ″ includes an outer annular ring  130 ″ which is connected to an inner ring  134 ″ by a maze structure  136 ″. The maze structure contains irregularly shaped, spaced-apart slots  138 ″ which eliminate the two chamber configuration of the prior art, provide additional support for the driver assembly  125 ″ and further, collimate the air flow and sound or acoustic energy uniformly as it passes from the area behind the driver assembly to the listener&#39;s ear. 
         [0034]      FIG. 6  depicts yet another embodiment of a diaphragm and driver assembly  142  in which the supporting frame  130 ,  130 ′,  130 ″ of the earlier embodiments is completely eliminated. In this embodiment, a diaphragm  144  and driver  146  are supported by arm  148  which is connected to a table assembly  150  mounted in the inner chamber of the earcup, as more clearly shown in  FIG. 7 . 
         [0035]    Moving to  FIG. 7 , table assembly  150  is mounted by legs  152  to an internal element of the headphone shell (not shown), by way of example, in the instant embodiment, a battery box  154 , which contains the headphone batteries. A PCB board  156  containing the circuitry and electronics for the operation of the headphone assembly may optionally be mounted intermediate the battery box and the table assembly; however, it may be located elsewhere within or external to the structure in accordance with space limitations and the overall configuration of the headphone shell design. A protective flow-free cover or cap  158  may also be mounted over the table assembly to protect the speaker and driver mechanism, as hereinabove described with respect to the supporting grid of the embodiment of  FIG. 4 . The protective cover  158  is illustrated in greater detail in  FIG. 8  and includes a plate member  160  in which are formed a plurality of holes or apertures  162  to permit free flow of sound from the speaker to the user&#39;s inner ear canal. 
         [0036]    Referring now to  FIGS. 9 through 15 , various embodiments of the battery cap  118  of  FIG. 1  are shown in greater detail. The battery cap includes a body portion  119  adapted to be removably mounted over a battery compartment or box (element  154  in  FIG. 7 ) typically formed in or secured to the earcup  110 . While in the embodiment shown, the body portion is generally oval or elliptically-shaped, it is to be understood that the configuration is shown for purposes of illustration only, and that other shapes and configurations may be used without departing from the scope of the present invention. The body portion includes an outer surface  122  in which is formed a speaker aperture  123  and an inner surface  124  adapted to fit over the battery compartment  154  in the ear cup. In the embodiment shown, the inner and outer surfaces are generally curvilinear in shape to conform to the overall shape of the ear cup for aesthetic reasons 
         [0037]    The inner surface  124  of the battery cap  118  is illustrated in greater detail in  FIGS. 10 and 11  and includes at least one reinforcing rib  127  formed integrally therewith or affixed thereto to stiffen the cap. In the embodiment shown, the cap also includes at least one upper lug  131  positioned on and secured to or formed integrally with an upper or first end portion  135  of the inner surface of the battery cap and at least one lower lug  133  positioned on and secured to or formed integrally with a lower or second end portion  139  of the inner surface of the battery cap. 
         [0038]    Each of the upper and lower lugs are adapted to be removably received in a corresponding aperture  141 ,  143  respectively formed in the earcup shell  110 , as shown in greater detail in  FIGS. 12 and 13 . Each of the upper lugs  131  includes an elongate body element  145  which is adapted to be received, aligned and retained in position by a corresponding elongate segment  147  of the apertures  141  and  143  respectively. The upper lugs each further include an angular end portion  149  which extends radially inwardly from the elongated body element and is adapted to provide an interference fit with the apertures  141  and  143  to hold the battery cap in position on the ear cup. In the embodiment of  FIGS. 10 and 11 , the angular end portion is shown to extend inwardly at an angle of approximately 45 degrees from the axis of the elongated body element. However, it is to be understood that the angle is not critical to the overall functioning of the lug and other angles may be used with equal effectiveness, depending upon the configuration of the ear cup and battery cap designs. By way of example,  FIGS. 14 and 15  depict yet another embodiment of the instant invention wherein the angular end portions  149 ′ are formed at substantially right angles to the elongated body elements  145 ′. 
         [0039]    Referring now to  FIGS. 10 and 14 , each of the lower lugs  133  includes a tapered member  151  which extends generally laterally outwardly from the lug from the lower end  139  of the battery cap  118  in a direction toward the upper end  135  of the battery cap in a direction substantially parallel with the plane of the inner surface  124 . Each of the tapered members  151  form a space  153  intermediate the inner surface  124  of the battery cap and the tapered member. Each of the spaces is structured and arranged to removably fit over an upper edge  155  of each of the apertures  143 , thereby locking the battery cap in place on the ear cup during operation by a wearer. To remove or change out the batteries (not shown), a user may simply depress the lower portion  139  of the battery cap to disengage it and thereafter slide it off the ear cup. To replace the battery cap on the ear cup, the upper and lower lugs are simply positioned within their respective receiving apertures and the battery cap is pushed under slight pressure toward the upper portion of the ear cup to lock it in place. 
         [0040]    Referring to  FIGS. 16-20 , means for selectively psychoacoustically calibrating, adjusting and balancing the sound volume in each earcup is shown generally at  200 . For purposes of simplicity, the means  200  will be referred to herein and in the appended claims as either balancing means or balance control device. The balancing means is designed to permit a wearer of the headphone apparatus who has monaural hearing loss to selectively increase sound volume directed to an ear having hearing loss without increasing sound volume directed to an ear having no hearing loss, thereby avoiding potential damage to and resulting hearing loss in the ear having normal hearing. 
         [0041]    The balance control device  200  includes a housing or body member  202  having a clip or fastener  204  affixed thereto to permit the wearer to attach the device to his or her belt or other clothing. The device is operatively connected to the headphone apparatus by cables or conductors  206 ,  208  extending from each end thereof. Control elements  210 ,  212  and  214  are adapted to turn the device on and off and to selectively calibrate, adjust and balance the sound volume directed to each headphone. In an embodiment, a calibration device (not shown) is incorporated into or operatively coupled to the balance control device and structured and arranged to provide clear sound tones in the sound transmission that are perfectly centered or balanced as intended by the composer of the original transmission. The headphone user then may reset the center point in response to the wearer&#39;s psychoacoustic perception of centered, balanced sound volume; and lock the balance control at the wearer&#39;s psychoacoustically perceived center, whereby all sounds subsequently delivered to the headphone apparatus will be calibrated to the balance of the original sound transmission. 
         [0042]    Changes may be made to the above methods, systems, devices and structures without departing from the scope hereof. It should be noted that the matter contained in the above description and/or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claim(s) are intended to cover all generic and specific features described herein as well as statements of the scope of the present invention, which, as a matter of language, might be said to fall therebetween.