Headset receiver cartridge and earphone case therefor
This is a continuing application of copending application Ser. No. 717,587 filed Mar. 29, 1985, which is a continuing application of Ser. No. 607,715 filed May 7, 1984, which is a continuing application of Ser. No. 354,120 Mar. 2, 1982, all abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to headset receivers and, in particular, to the combination of a separate receiver and an earphone case therefor. 
     2. Description of the Prior Art 
     While the present invention is particularly adapted for use in aircraft passenger entertainment systems, it is to be understood that its use is as applicable for listeners in any environment. However, because the invention was devised specifically for aircraft passenger entertainment systems, the ensuing discussion and description will be specific thereto. 
     The existing passenger entertainment system on aircraft utilizes acoustical headsets, which are plugged into a mating recepticle in individual seat arms. The acoustical signal is derived from various electronic components including a control unit in the passenger&#39;s seat arm, an electronics box at the seat, and other electronic hardware elsewhere on the airplane. 
     It is generally agreed among users of the existing acoustical headsets that they are cumbersome because the headset must be connected to the seat arm, that they have relatively poor sound reproduction because of the extreme length of the acoustical tubing, and that they have an inherently uncomfortable fit. However, they are relatively inexpensive so that, after they are retrieved after each flight, they may be discarded or, if desired, cleaned and returned to the next user. The low cost of the existing acoustical headsets, however, is more than compensated for by the high cost of that electronic equipment which is in the seat and the cost of the installation therein and repair thereof. In addition, existing hardware adds between 250 and 350 pounds to airborne vehicles. 
     Companion patent application Ser. No. 354,101, now U.S. Pat. No. 4,465,907 entitled &#34;Headset Receiver and Storage and Sanitizing Case Therefor&#34; by the same inventors hereof and filed concurrently herewith, overcomes and avoids the problems described above. The invention described therein involves the use of a special storage case with means for sanitizing each headset receiver. For some users, such as aircraft companies or other suppliers of entertainment, such a storage and sanitation case may not be preferred as being undesired extra equipment involving an additional, albeit small, added cost. Therefore, an alternative was suggested in the form of the present invention. 
     SUMMARY OF THE INVENTION 
     The present invention utilizes a cartridge whose housing contains a receiver of wireless transmitted information. The cartridge is receivable within a disposable case which serves not only as a protective and sanitized envelope for the cartridge but also as a means for conducting sound from the cartridge to a listener&#39;s ears. Since the case contains no active components, its cost is low and, therefore, it is disposable and can be furnished as a sanitized item within a suitably sealed envelope. It is designed to be separated from the cartridge at the end of its use, such as at the end of an airplane flight, removed from the premises or aircraft, and disposed of. Alternatively, if desired, it may be sanitized and repackaged with a new battery and fresh earpads and returned for another flight. It may, in addition, utilize the storage and sanitizing case of companion application Ser. No. 354,101, now U.S. Pat. No. 4,465,907. The more expensive cartridge with its electronic components may be either collected by an attendant or tethered to the seat by a lanyard and retained within a pouch at the seat. 
     Several advantages are derived from the present invention. It permits a relatively high cost cartridge to be left aboard the aircraft or other entertainment center and to be collected either by an attendant or left at the listener&#39;s seat. Pilferage or misplacement of the cartridge is minimized, especially when it is tethered to the seat. Sanitization is simplified. Being small and light weight, both the cartridge and the case eliminate considerable weight, which is particularly important in aircraft. For example in a widebodied type airplane, it is estimated that approximately 150 to 250 pounds can be saved with attendant savings in fuel consumption and cost. The acoustical stems leading from the case to the listener&#39;s ears can be short, thereby increasing the fidelity of the sound transmitted. 
     Several advantages follow from the above system. If used with the carrying and storage case of companion application Ser. No. 354,101, now U.S. Pat. No. 4,465,907, it provides an accurate method of headset accountability as well as automatic sanitizing of the headsets as a normal occurrence during their insertion or withdrawal from storage case. In both cases, it enables the headsets to be used on a particular aircraft and kept on board, thereby eliminating the need for continual reprovisioning. 
     The cartridge itself provides several advantages. It comprises a wireless design and, therefore, eliminates any electrical or acoustical connections to the arm of the seat. The shortness of the stems not only improves the quality of sound to the passenger&#39;s ears but is also more easily shapable to ensure a comfortable fit. The smooth exterior not only eliminates snagging and enhances storage within the case, but is also esthetically pleasing. It enables a battery to be easily replaced. It also provides easy access to the system controls, that is, it avoids a prior problem of blockage of the seat arm controls by seat trays, blankets and the like. As a corollary, should the unit malfunction, it can be easily replaced and, if desired, repaired away from the seat and the aircraft, thereby decreasing the non-used time of the aircraft over the time needed to repair conventional in-seat arm electronics. 
     Other aims and advantages as well as a more complete understanding of the present invention will appear from the following explanation of an exemplary embodiment and the accompanying drawings thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 depicts a cartridge for housing a receiver of wireless-transmitted information, and a lanyard tethering the cartridge to a seat; 
     FIG. 2 is a perspective view of a case for receiving the cartridge and for furnishing sound from the cartridge to a listener&#39;s ears; and 
     FIG. 3 is a view of the case taken from its closed end, as viewed from the right side of FIG. 2, with a cartridge received therein. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As illustrated in FIG. 1, a cartridge or housing 10 contains all the electronic circuits needed to receive electromagnetic energy, such as infrared (IR) energy, from a transmitter. 
     Electronic circuits for generating and receiving IR signals are known in the art. Examples include U.S. Pat. No. 4,229,829 and the references cited therein, and two publications entitled &#34;Stereo drahtlos&#34; (Wireless Stereo), &#34;Infrarot-Stereo-Kopfhorer&#34; (Infrared Stereo Headphones), appearing in a Swiss publication entitled &#34;radio-tv-electronic&#34;, Vol. 37, No. 5, May 1977, pages 67-69, and &#34;Fernsehton uber Infrarot-licht zum Kopfhorer oder zur HiFi-Anlage&#34; (Infrared Transmission of Television Sound Channels to Headphones or Hi-Fi Equipment), appearing in an Austrian publication entitled &#34;Radio Elektronik Schau&#34;, Vol. 51, No. 9, 1975, pp. 484-486. A similar headphone to that illustrated in the second figure of the latter publication appears in the tenth edition of the Sennheiser Review of August 1979 on pp. 76 and 77 thereof. 
     Housing 10 is shown as having a smooth exterior surface including front surface 12, rear surface 14, and edge surfaces including bottom surface 16, top surface 18, and side surfaces 20. Shown as extending on front and top surfaces 12 and 18 is a cover 21 which is flush with surfaces 12 and 18 and acts to protect the detector of electromagnetic energy. Channel selection and volume controls are effected by turnable, knurled knobs 22 which are placed at ends or sides 20 of the cartridge. Sound is transmitted from ports 24 positioned on top surface 18, or other appropriate surface. 
     To prevent pilferage or misplacement of the cartridge, a lanyard 26 may be tethered at its ends to the case and to a seat 28. A pouch 30 may be secured to the seat to receive the cartridge when not in use. 
     When in use, cartridge 10 is slipped within a case 32 shown in FIGS. 2 and 3. Case 32 comprises a tubular shell 34 whose interior configuration is substantially the same as the exterior configuration of cartridge 10 to permit receipt thereof. The case includes front and rear faces 36 and 38, bottom and top faces 40 and 42, and sides or ends 44 and 46, the latter which is also shown in FIG. 3. Shell 34 is open at its end or side 44 for receipt of cartridge 10. Its other end or side 46 comprises a wall which is at least partially closed and thus acts as a limit for receipt of the housing within the case. Partially closed end 46 has an opening 48 therein (see FIG. 3) so that knob 22 at the right hand side 20 of the cartridge is exposed for access by the listener. The other knob already extends through open end 44. 
     To ensure that cartridge 10 will not slip out of case 32, cooperating detents 43 and notches 45 respectively on the case and the cartridge engage when the cartridge is fully inserted in the case. Other holding means may be used, if desired. 
     A pair of ears 50 extend from top face 42 of the case at the corners where face 42 meets with sides 44 and 46. A pair of acoustical stems 52 extend from ears 50 and are provided with earpads 53 secured in a suitable manner to adapters on stems 52. The ends of stems 52 in ears 50 have the same spacing between them as sound openings 24 of cartridge 10 so that, when the cartridge is fully received within case 32, there will be proper alignment of openings for transmission of the sound through the stem and to the listener&#39;s ears. 
     If desired, case 32 is provided with a decreasing thickness of its front and rear surfaces 36 and 38 to provide a beveled configuration denoted by indicium 54, in the event that the use of a storage and sanitizing case as described in copending application Ser. No. 354,101, now U.S. Pat. No. 4,465,907, if desired. 
     Cartridge 10 further includes a recessed opening 56 for reception of a battery and at least one cutout 58 adjacent the battery recessed opening to facilitate removal of a battery therefrom. Alternatively, the battery may be incorporated with case 32 with provisions for automatically connecting the battery to receiving contacts on cartridge 10 when inserted into the case. 
     Although the invention has been described with reference to a particular embodiment thereof, it should be realized that various changes and modifications may be made therein without departing from the spirit and scope of the invention.