Abstract:
An interface adapter ( 32, 46, 48, 52, 82, 90 ) is connectable to a video camera ( 10 ) for example in security or surveillance applications. The adapter ( 32 , etc.) conveniently provides interfacing for transmission of video signals generated by the camera, employing any one or more interfaces or transmission media, such as fiber-optic, radio frequency (RF), internet protocol (IP), wireless, twisted-pair (UTP), etc. By using the adapter, a single camera model having one native output transmission connector ( 14 ) can be deployed for a variety of applications that may require various other transmission media or connections ( 34, 36, 50, 92 ). The adapter makes the camera immediately ready for installation and connection to any desired transmission media without time-consuming wiring of external or standalone transmitters or transceivers. And the adapter preferably conforms to the camera enclosure for a clean, unitary appearance of the combined apparatus (FIG.  3 , FIG.  11 ).

Description:
COPYRIGHT NOTICE  
         [0001]    © 2003 General Electric Company. A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR § 1.71 (d).  
         TECHNICAL FIELD  
         [0002]    The invention pertains to video cameras and related equipment and, more specifically, is directed to interfacing a video camera to transmit video signals over various signal transmission media.  
         BACKGROUND OF THE INVENTION  
         [0003]    Closed-circuit television or CCTV is widely used for video security/surveillance, video distribution, distance learning and other applications. Frequently, remote CCTV cameras, for example those mounted in a warehouse or overlooking a parking lot, are wired to a monitoring station which may comprise one or more monitors for watching the video (and sometimes audio) stream, and/or recording equipment (DVR—digital video recording—for example) for capturing and storing the surveillance signals.  
           [0004]    Various transmission methods and media are known for transmitting the video signals (which may include audio signals) from the camera to a remote monitor and/or recording system. The different transmission protocols and media offer choices to enable a user to trade off cost, interference immunity, signal loss (i.e., maximum distance), etc. Known transmission media include: coaxial cable (most commonly used), fiber-optic, radio frequency (RF), internet protocol (IP) (which may employ computer network wiring such at CAT-5), wireless, twisted-pair (UTP), etc. UTP would include ordinary telephone wiring, for example of the type terminated with RJ-11 or RJ-45 connectors.  
           [0005]    Each of these media requires its own electrical/mechanical connectors. Examples of such connectors include BNC; RJ-11; RJ-45; Fiber-type; RCA etc. and terminals for twisted pair (UTP), coaxial cable, and others. Wireless systems or course have no physical connection between the transmitter and receiver nodes, but they require connections to input signals to the transmitter and, conversely, to output signals from the receiver device. The appropriate connector for a particular application may or may not be built into the camera at the time of manufacture.  
           [0006]    In addition, various transmitters, receivers and transceivers are known for conveying video signals. These may be passive (non-amplified) or active, the latter enabling transmission over greater distances. For example, a typical known passive video transmitter will transmit full-motion video up to 1,000 feet over UTP, while the same transmitter used in conjunction with an amplified receiver is reported to operate up to 3,000 feet.  
           [0007]    In general, a video surveillance camera has a video output connector or jack, or perhaps two different ones, built into the product. We will refer to such a connector as the “native” connector; the one already on the camera as purchased. A BNC connector is a common native connector. This works fine for connection to transmitters or cables that have a BNC input jack, but is incompatible with other connectors such as RJ-11 or RCA which may be needed for the transmission media (wiring) at hand. Installation of the camera in such applications requires the installer to deploy some kind of adapter, and to install the adapter between the camera and the transmission medium. Installing the adapter requires both electrical connection and mechanical mounting. This kind of activity adds to the time and expense of video camera installation, especially as it may be required at every camera throughout a large facility. Examples are shown in drawing FIGS. 1A and 1B further described below.  
           [0008]    The need remains therefore for a fast, simple and convenient way to interface a video camera to a transmission media that requires a connection different from the “native” connector or connector(s) built into the camera at manufacture.  
         SUMMARY OF THE INVENTION  
         [0009]    One aspect of the invention is directed to the concept of an interface adapter for mounting to a video camera, primarily for transmitting video signals originating in the camera to another location. The adapter can also provide other functions such as power distribution. Installation of the camera is simplified in many cases because the adapter provides the appropriate connector(s) for the application at hand. The video camera has at least one built-in or “native” connector typically on the back panel, to output the video signals. An adapter according to the invention includes input means arranged for electrical connection to the native connector to receive the video signals originating in the camera while the adapter is connected to the camera. The adapter further provides output means for conveying the video signals from the adapter to a transmission medium; for example, twisted pair, fiber optic or other cabling, or wireless transmission.  
           [0010]    Accordingly, the output means is electrically coupled to the input means to receive the video signals originating in the camera. By the term “coupled” we mean a direct electrical connection, or an indirect connection that involves a transmitter, filter, amplifier, A/D converter or other electronic circuitry that takes the video signals generated by the camera as its input. In a presently preferred embodiment, the output means includes a terminal block or other connector to provide mechanical and electrical connection to a corresponding wired transmission medium such as UTP. The output means generally includes at least one of a twisted-pair connector, a BNC connector, an RCA connector, a USB connector or other analog or digital data connection. The output means can be wireless, in which case the electronic circuitry mentioned above would comprise a wireless transmitter. The output means could be fiber optic. These are merely examples and not listed by way of limitation. Multiple output connectors can be provided on one adapter. For example, a first connector can be provided for signal transmission and a second connector for temporary connection to a monitor for testing.  
           [0011]    Preferably, the adapter is built into a substantially rigid housing that is generally shaped so as to cover at least a portion of the back panel of the camera that includes the native connector. The interface adapter assembly also should be mechanically compatible with the camera so as to enable removably connecting the adapter to the camera without modifying the camera. For example, the screw holes typically used to attach the back panel to the camera could be used to receive screws for mounting the adapter.  
           [0012]    As a matter of design choice, the adapter can have any desired size or shape, but preferably it generally conforms to the configuration of the target camera. In other words, the adapter should look like a part of, or extension of, the camera when installed. This can be done, for example, by sizing the adapter to overlay a portion of the camera, with smooth transitions, while minimizing protrusions extending from the camera. So, for example, an external surface of the adapter housing would preferably parallel an external surface of the camera housing. These design principles will become more apparent in view of the various examples shown in the drawing figures and described in detail below.  
           [0013]    Additional aspects and advantages of this invention will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a simplified diagram illustrating a prior art video system for transmitting video signals from a video camera to a remote location.  
         [0015]    [0015]FIG. 2 is a perspective view of a video camera and cable connections (exploded) representative of the prior art.  
         [0016]    [0016]FIG. 3 is a perspective view of a video camera with attached interface adapter and cabling in accordance with a first embodiment of the present invention for fiber optic transmission.  
         [0017]    [0017]FIG. 4 is an exploded view of the apparatus of FIG. 3.  
         [0018]    [0018]FIG. 5 is a perspective view of the interface adapter of FIGS. 3-4.  
         [0019]    [0019]FIG. 6 is another perspective view of the apparatus of FIG. 3.  
         [0020]    [0020]FIG. 7 is a perspective view of an alternative embodiment of an interface adapter for fiber optic transmission.  
         [0021]    [0021]FIG. 8A is a perspective, exploded view of a second embodiment interface adapter for UTP transmission.  
         [0022]    [0022]FIG. 8B is a perspective view of the adapter of FIG. 8A assembled.  
         [0023]    [0023]FIG. 9 is a side view, exploded, of a video camera and interface adapter of FIGS. 8A and 8B.  
         [0024]    [0024]FIG. 10A illustrates another embodiment of an interface adapter in accordance with the present invention.  
         [0025]    [0025]FIG. 10B illustrates another embodiment of an interface adapter in accordance with the present invention.  
         [0026]    [0026]FIG. 11A is a perspective view of a video camera and attached interface adapter in accordance with another embodiment of the invention.  
         [0027]    [0027]FIG. 11B is an alternative perspective view of the apparatus of FIG. 11A. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0028]    [0028]FIG. 1 is a simplified diagram illustrating a prior art video system. Here, a video camera  100  has a video output connector (not detailed) to provide video output signals. A cable  102  is connected between the video output connector on the camera and a transmitter device  104 . An example of such a transmitter is model NV-314A available from Network Video Technologies (“NVT”), Redwood City, Calif. In a typical installation, the transceiver  104  is mounted near the camera. The transceiver provides appropriate interfacing for transmitting the video output signals over an unshielded twisted pair of wires (“UTP”)  106  with low signal loss. The transmitter can be passive (unpowered) or powered, in the latter case providing for transmission over greater distances, e.g., up to 3,000 ft. Although UTP cable is itself inexpensive and easy to use, providing connectors such as RJ-45 on the ends of the cable increases installation costs.  
         [0029]    A second transceiver  108 , compatible with or even identical to the first transceiver  104 , is provided at the far end (away from the camera) for interfacing the UTP  106  to a coax cable  110  which, in turn, is connected to a video monitor  112  and/or other equipment such as a video motion detector. (Video signals, in this example and in general, can include audio content as well.)  
         [0030]    [0030]FIG. 2 is a perspective view of a video camera  10  seen generally from the rear. Camera  10  has a back panel  12  on which one or more connectors are fixed for establishing electrical connections to the camera. While the number and types of connectors varies, FIG. 2 illustrates a common configuration that includes a first BNC connector  14  and a second BNC connector  16 , each used for transmitting video signals from the camera to a remote location such as a security monitoring station or recorder. It is also known to send control signals “up-the-coax” i.e., to the camera over the same cable, for controlling camera functions remotely. We refer hereinafter to connectors that are built into the camera (like  14 , 16 ) as “native” connectors.  
         [0031]    In FIG. 2, a first cable  20  (for example, a coax cable) has a male BNC type connector  22  for mating to native connector  16  on the camera back panel  12 . Another cable  24  has a connector  26  for mating to a corresponding connector  30  on the back panel  12  to power the camera, usually supplying 12 or 24 VDC from an external power supply. Typically, coax cable  20  is connected to a transceiver, just as coax cable  102  is connected to transceiver  104  in FIG. 1A, described above.  
         [0032]    Referring now to FIG. 3, we introduce a new video camera interface adapter assembly. In one embodiment, illustrated in FIG. 3, the interface adapter  32  is removably attached to the camera  10  generally overlying the back panel  12 . The peripheral edge of the adapter facing the camera ( 17  in FIG. 4) is sized and shaped to generally conform to the periphery of the back of the camera so as to appear, when installed (as in this figure), to be a part or extension of the camera. The interface adapter assembly  32  in this embodiment includes a terminal block  34  and a fiber optic connector  36 . Power supply wiring  40  is shown installed into the terminal block  34  to power a fiber optic transmitter (or transceiver) in the adapter (not shown). FIG. 6 shows the apparatus of FIG. 3 from the right rear perspective.  
         [0033]    [0033]FIG. 4 shows the apparatus of FIG. 3 in exploded view. The adapter  32  is removably attached to the camera with screws  42  or the like so that the adapter generally covers the back panel  12 . The screws  42  pass through holes in the adapter and are received in mounting holes  43  normally provided in the camera back panel. The adapter in this embodiment forms an aperture  44  arranged so that the camera power connector  30  is exposed and available for connection to cable  24  via mating connector  26 . The adapter in this configuration thus does not affect the camera power connection.  
         [0034]    The interface adapter ( 32  being just one example) can have any of various configurations. To illustrate, FIGS.  3 , 4 , 5 , 6  and  7  show an adapter  32  with a terminal block  34  and fiber optic connector  36 , as noted above. In such configurations, power is supplied to the terminal block to power the fiber optic circuits. FIGS. 8A, 8B and  9  illustrate an alternative adapter  46  which has only a terminal block  34  for UTP output connection. FIG. 10A is a perspective view of an alternative adapter assembly  48  that includes a USB-type external connector  50  which could be used for a digital data connection. Multiple output connections can be implemented in a single adapter, again simplifying installation for many applications.  
         [0035]    [0035]FIG. 10B illustrates another embodiment; an adapter assembly  52  that employs a wireless transceiver (not shown) for communicating video signals. Indicator lights  80  (LEDs) can be provided to indicate a present status of the wireless transceiver (for example, power and signal acquisition). Wireless transceiver circuits, for example IEEE 802.11 series, “WiFi” or Bluetooth, are known and commercially available from various vendors. Next we describe a UTP embodiment  46  in greater detail.  
         [0036]    Adapter  46  is attachable to a camera as described earlier with regard to the adapter  32 . Referring to FIG. 8A, adapter  46  comprises a housing  56  formed of any sturdy, rigid material such as a molded polymeric material. The housing provides mounting screw holes, for attaching the adapter to the camera, although other attaching means can be used as a matter of design choice. Preferably, the housing is sized and arranged to generally conform to the configuration of the back and/or any one or more sides of the camera to which it will be attached. For example, at least a portion of the perimeter edge  57  of the housing should fit closely along the camera perimeter so as to give the combination a unitary, tidy appearance when the adapter is installed. In one anticipated commercial embodiment called PlusPacks™, the adapter assembly extends only about 3.2 cm beyond the back panel, yet it eliminates the need for an external transmitter and associated wiring to convert BNC analog video to twisted pair output.  
         [0037]    Referring now to FIGS. 8A and 8B, adapter  46  in a presently preferred embodiment further comprises a circuit board  58  mountable inside the housing  56 , for example using screws. Referring now also to FIG. 9, the circuit board  58  includes the terminal block  34  securely mounted on the underside  60  of the circuit board, and located on the board so that the terminal block  34  extends through an aperture  62  provided in the housing  56  when the board  58  is mounted in the housing, as indicated by dashed lines in FIG. 8A and FIG. 9. In this embodiment, the terminal block is used to connect a pair of wires for UTP video signal transmission.  
         [0038]    A connector  64  is securely mounted the top side  68  of circuit board  58 . (The designations “underside” and “top side” here are arbitrary.) Connector  64  is located and aligned for mating engagement with a native connector on the camera back panel when the board  58  is mounted in the housing  56  and the adapter  46  is connected to the camera. FIG. 9 shows in side view how the connector  64  is aligned for engagement with native connector  16  on the camera. In one embodiment, connector  64  is a “push-in BNC” connector. It is compatible for “push-in” engagement with a standard BNC female connector ( 16 ) without the usual “push-and-turn” operation. Connector  64  thus couples video output signals from the camera to the adapter circuit board  58  when in use.  
         [0039]    The interface adapter  46  in this example further includes a transmitter module  70  also mounted on the top side  68  of circuit board  58  although its location is a matter of design choice. Transmitter  70  provides suitable interfacing for transmitting video signals over wires connected to the terminal block  34 , e.g., UTP transmission. Accordingly, the circuit board  58  includes conductors (traces) for electrically connecting the push-in BNC  64  to the transmitter  70  input terminals (not shown), and traces  72  (see FIG. 8A) for connecting the transmitter output terminals to the terminal block  34 . Transmitters of this type are commercially available, one example being model NV-M11 from NVT. For other designs, the appropriate transmitter or transceiver, if any, or other circuitry such as a filter or amplifier, will be determined by the output transmission media, transmission distance, environment, and the like.  
         [0040]    In the fiber optic embodiment of FIGS. 3 and 4, the adapter  32  is outwardly similar to adapter  46  as described, with the addition of the fiber optic output connector  36 . And in that case, the terminal block is used to supply power rather than UTP output connections. The fiber connector  36  can be deployed by mounting it on the underside  60  of a circuit board similar to board  58 , and providing a suitable aperture  74  in the adapter housing, as best seen in FIG. 5. Circuit board  58  in that embodiment would further include traces for connecting the push-in BNC  64  to the fiber optic transmitter signal input terminals (not shown), and for connecting the transmitter output terminals to the output connector  36 . Alternatively, a second push-in BNC connector (not shown) could be mounted on the top side of the board and aligned for engaging a second native connector  14  (see FIG. 9). Other types of connectors, for example, RCA, or S-video connectors or adapters can be deployed on the circuit board as appropriate to the native connector(s) of the target video camera.  
         [0041]    Furthermore, any set of one or more desired output connectors can be implemented in the adapter; the appended illustrations shown only a few examples. In the example of FIG. 10A, a USB connector  50  would be mounted on the underside  60  of the circuit board of FIG. 9, in lieu of the terminal block, and necessary interface electronics provided. In the example of FIG. 10B, a wireless transceiver is provided, as noted. It too can be mounted on the circuit board described. The circuit board can be designed to provide power to various transceivers as needed. The power can be provided from a battery or external power source via the terminal block.  
         [0042]    Another approach is illustrated by FIG. 7. The adapter assembly  82  of FIG. 7 is sized and shaped to cover substantially the entire back panel of the camera. Instead of providing an aperture for a power connection to the native power connector ( 30  in FIG. 4) as described earlier, this adapter includes a “pig tail” assembly  83  for connecting the adapter to the camera&#39;s native power connector before attaching the adapter  82  to the camera. Here, power is supplied for both the camera and the video signal transmission electronics from a terminal block  88 . This embodiment can include a fiber optic output  74  or any of the wired or wireless transmission media described earlier. This design avoids multiple power connections.  
         [0043]    Referring now to FIGS. 11A and 11B, another example of an embodiment of the present invention is illustrated. Here, an alternative interface adapter  90  is shown attached to the video camera  10 . Various input and output connections can be provided in the adapter as discussed above. For example, the drawing shows an RJ-45 receptacle  92  for IP connection and a terminal block  94  (which could serve as a UTP output or a power input). A conventional camera power input connector  26  is shown.  
         [0044]    The interface adapter assembly  90  illustrates the concept of an adapter design that generally conforms to more than one face of the camera  10 . Here, the adapter includes a rear section  96 , similar to embodiments described above, and a top section  98  extending at least partially along the top side of the camera and having a width substantially equal to the width of the camera. Sections  96  and  98  are substantially contiguous, forming a smooth exterior surface, and are substantially contiguous or at least communicating with one another in the interior (the space generally between the camera and the adapter housing).  
         [0045]    This type of configuration provides considerable additional space inside the adapter to house power supply and various interface circuitry as may be required. In general, the adapter can extend over any side or sides of the camera, part way or the full length of the camera. Preferably, it will cover at least a part of the back panel for engaging at least one native connector. Again, the adapter should generally comply with the camera shape and size, at least in part, for a neat appearance.  
         [0046]    It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims.