Abstract:
The present invention provides a fiber optic jack for routing optical signals. In another aspect, the present invention provides a fiber optic connector with accurate alignment that may be used with, among other things, the fiber optic jack.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of application Ser. No. 12/699,255, filed on Feb. 3, 2010 (status pending), which claims the benefit of U.S. provisional patent application No. 61/149,568, filed on Feb. 3, 2009. The entire contents of the above identified applications are incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention generally relates to apparatuses for optically connecting optical fibers. 
     2. Related Art 
     A copper jack is very common and almost universally used in the broadcast industry to manually route electrical signals through a broadcast studio, mobile studio or other area where electrical signals need to be routed. As more and more data is being transmitted using optical signals rather than electrical signals there is a need to produce an optical jack that can be used to route optical signals. 
     SUMMARY 
     In one aspect, the present invention provides a fiber optic jack for routing optical signals. 
     In another aspect, the present invention provides a fiber optic connector with accurate alignment that may be used with, among other things, a fiber optic jack according to embodiments of the invention. 
     The above and other aspects and embodiments are described below with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements. 
         FIGS. 1-8  illustrate a fiber optic jack according to embodiments of the invention. 
         FIGS. 9-11  illustrate a fiber optic connector according to an embodiment of the invention. 
         FIG. 12  illustrate a fiber optic connector according to another embodiment. 
         FIGS. 13-14  illustrate a fiber optic connector according to another embodiment of the invention. 
         FIGS. 15-25  further illustrate a fiber optic jack according to embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1 ,  FIG. 1  illustrates a fiber optic jack  100  according to some embodiments of the invention. In the embodiment shown, jack  100  has four ports (ports  102   a,b  and  104   a,b ) (e.g., four connectors). Two on the front and two on the back. Each port is configured to mate with (e.g., receive) a counterpart fiber optic connector. In the embodiment shown, each port is a female connector for mating with a male or hermaphroditic fiber optic connector. 
     Jack  100  has two modes of operation. A “normal” mode and an “interrupt” mode. 
       FIG. 2  illustrates jack  100  operating in the normal mode. In the normal mode of operation, a first fiber optic connector  202   a  is inserted into rear port  102   a  and a second fiber optic connector  202   b  is inserted into rear port  102   b . In this configuration, jack  100  optically connects connector  202   a  to connector  202   b  via, for example, an optical signal reflector  110  (e.g., a prism or other optical signal reflector). Accordingly, the rear ports are the ‘normal’ connection and would be used to connect an input and an output signal that are connected together under normal operation of the system. 
     For the sake of illustration, we will assume that connector  202   a  houses an end of an optical fiber that outputs an optical signal into jack  100 . Accordingly, this optical signal is reflected by reflector  110  such that the optical signal is injected into connector  202   b . Fiber optic connectors  202   a  and  202   b  may be expanded beam connectors. 
     Referring now to  FIG. 3 , when it is desirable to gain access to this optical signal, a third connector  204   a  may be plugged into front port  104   a  of jack  100  causing the optical signal to be injected into connector  204   a . For example, in some embodiments, when connector  204   a  is fully inserted into port  104   a  an optical path from connector  202   a  to connector  204   a  is automatically created so that any optical signal output from connector  202   a  will be received by connector  204   a . Similarly, when a connector  204   b  is fully inserted into port  104   b  an optical path from connector  204   b  to connector  202   b  is automatically created so that any optical signal output from connector  204   b  will be received by connector  202   b.    
     This allows insertion of a new signal into the signal path and monitoring of the signal that is present on the rear of the jack by attaching a connector into the front of the jack. For example, if a signal containing an HDTV picture from a camera is carried by the optical fiber connected to connector  202   a  and this signal is normally routed to a studio monitor in another room via connector  202   b  and one wanted to observe the HDTV signal, then one could plug patch cord connector  204   a  into port  104   a , thereby diverting the optical signal into the optical fiber of patch cord connector  204   a . Thus, by placing the other end of the optical fiber connected to connector  204   a  into a portable monitor, the optical signal would be routed to the front connector and appear on the portable monitor. At the same time, an alternative signal from another camera that is carried by the optical fiber of connector  204   b  could be inserted into the optical fiber of connector  202   b  by plugging connector  204   b  into port  104   b . This is one example and there are many other reasons why patching may be desirable. Jack  100  may also be implemented with a monitor channel thus having two rear and three front ports. 
     Referring back to  FIG. 1 , jack  100  further includes: a reflector holder  105  for holding reflector  100 , a jack housing  107 , which, in the embodiment shown, includes a jack base  106  for receiving the reflector holder  105 . Jack housing  107  may also include a jack cover (not shown in  FIG. 1 ). 
     Jack Base  106   
     In the embodiment shown, jack base  106  contains four alignment means (e.g., grooves). Two rear alignment means  120   a ,  120   b  and two front alignment means  121   a ,  121   b . Each of the rear alignment means  120  accepts an alignment sleeve of a fiber optic connector (see e.g., alignment sleeve  508  shown in  FIG. 9 ) and aligns the optical axis of the first rear connector  202   a  with the optical axis of the second rear connector  202   b , through the prism  110 , forming a low loss connection between the two connectors. The front two alignment means  120  are arranged in proximity to the prism base such that inserting a connector into a front port ( 104   a  or  104   b ) causes the reflector holder  105  and reflector  110  to move out of the optical path between port  102   a  and  104   a  and the optical path between port  102   b  and  104   b  and cause the front connectors to be aligned to the rear connectors forming low loss connections between the two pairs of connectors. Removing the connector from the front panel will cause the prism and prism base to return to their previous position, again creating a low loss connection between the two rear connectors. The front and rear alignment means may be a V-groove machined into the base  106 , a hole drilled in the base, a number of raised features inserted or machined into the base, or other method of optically aligning the connectors with the reflector and front and rear connectors. 
     Reflector  110   
     In some embodiments, reflector  110  is a prism, mirror or reflective coated material that will reflect the optical signal from a connector attached to one rear alignment to the other rear alignment means. 
     Reflector Holder  105   
     The reflector holder  105  holds the reflector  110  and allows the reflector to be moved out of the line of the optical beam and return to a position that is kinematically aligned such that the insertion loss is consistent between switching operations. The reflector holder  105  also allows alignment of the prism to the mechanical references using the optical axes during manufacture of the jack. 
     Referring back to  FIG. 3 , as shown in  FIG. 3 , when a counterpart fiber optic connector is inserted into port  104   a  or  104   b  by at least a certain amount, the insertion of the connector causes reflector holder  105  to automatically move reflector  110  so that there is a free optical path between ports  102   a  and  104   a  and between ports  102   b  and  204   b . Referring now to  FIG. 4 , in some embodiments, holder  105  has two slanted surfaces  401  and  402  that face ports  104   a  and  104   b , respectively. Jack  100  is configured such that when a connector (e.g., connector  204   a ) is inserted into port  104   a  or  104   b  by at least a certain amount, the front end  508  (a.k.a., alignment sleeve  508 ) of the connector  204   a  contacts holder  105  at slanted wall  401 / 402  and, because walls  401 / 402  are slanted, exerts an upward force on holder  105  causing holder  105  to automatically move upwardly relative to base  106 . This feature is further shown in  FIG. 5 , which shows a cross-sectional view of jack  100  and connectors  202   a ,  204   a . Referring back to  FIG. 1 , guide pins  130   a - c  guide holder  105  upward when a member presses against wall  401 / 402 . That is, guide pins  130   a - c  prevent holder from moving in the directions of ports  102   a  and  102   b  when an object exerts a force in the direction of ports  102   a  and  102   b  on wall  401  or  402 . 
     Referring now to  FIG. 6 ,  FIG. 6  further illustrates holder  105 . As shown in  FIG. 6 , holder  105  has a floor  602  on which reflector  110  rests. Accordingly, when holder  105  moves upwardly due to a force on wall  401 / 402 , the holder  105  carries the reflector  110  with it. This causes the reflector  110  to move such that it no longer receives the optical an optical signal injected into jack  100  via one of the ports  102   a - 104   b.    
     Referring now to  FIG. 7 ,  FIG. 7  further illustrates jack base  106  according to some embodiments. In the embodiment shown, base  106  includes one or more alignment balls  702  for aligning reflector holder  105  in the correct position with respect to jack base  106 . In the embodiments where alignment balls  702  are used to align reflector holder  105  relative to jack base  106 , reflector holder  105  includes one or more corresponding kinematic features  802  (e.g., a ball shaped indentation  802   a , a V shaped groove  802   b , and a planar feature  802   c ) (see  FIG. 8 , which shows a view of the bottom of reflector holder  105 ) for receiving an alignment ball  702 . 
     As also shown in  FIG. 7 , jack base  106  may include an alignment magnet  710 . Magnet  710  exerts a downward force on reflector holder  105  and, thus, serves to pull the reflector holder  105  onto the alignment balls in the normal position. In the non-normal position (i.e., the interrupt position), the magnet continues to apply some force such that when the connectors are removed from the front of the jack  100 , the holder  105  settles back to precisely the same position, realigning the prism  110  in the loopback configuration. The magnet  710  could easily be replaced with or supplemented by a standard compression spring, inserted between a cover (not shown) that covers jack base  106  and the prism holder  105 . 
     If the alignment rods  130  were replaced with rotary hinge mechanism, the rotary force would also create a spring force, eliminating the need for a spring or magnet. In the normal condition, the guide rods  130  do not touch or align the prism, this is done by the alignment balls. However in the interrupt actuated position, there is no need for any accurate alignment. The guide rods serve to loosely align the prism holder  105  vertically and ensure that when a connector is inserted into a front port ( 104   a ,  104   b ) the prism holder  105  is moved enough so that the prism does not block the path between port  102   a  and  104   a  or the path between port  102   b  and  104   b . These alignment rods  130  could also be implemented as a hinge mechanism, secured to a rotary joint on the base  106  and guiding the prism holder  105  vertically using a loose rotary attachment on the prism holder. 
     Counterpart Fiber Optic Connectors 
     Referring now to  FIG. 9 ,  FIG. 9  is a cross sectional view of a connector  204 , according to some embodiments. As shown in  FIG. 9 , connector  204  includes: a rear alignment sleeve  902 ; a lens  904 ; a lens holder  906 ; a front alignment sleeve  508 ; and a housing  910 . The lens holder  906  may include a cylindrical tube with a hole in the rear to accept an optical fiber or ferrule (see e.g.,  FIG. 12  element  1204 ) holding an optical fiber. 
     The lens holder  906  is configured to contain securely lens  904  and has a front section  1102   b  (see  FIG. 11 , which further shows holder  906 ) which is convex spherical with the center of the sphere located approximately at the front center of the lens. The lens  904  may be attached to the inside of the holder  906  using epoxy or other retention means such as a retaining ring. 
     The front alignment sleeve  508  may be a cylindrical shaped tube with a concave spherical rear section  1002  (see  FIG. 10 , which further shows sleeve  508 ) that mates with the front section of the lens holder  906 . 
     In use, in some embodiments, a fiber is attached in a ferrule using standard epoxy curing and fiber and ferrule polishing techniques to someone skilled in the art. The ferrule containing the fiber is inserted into the rear alignment sleeve  902 , thus positioning the tip of the fiber so that it is placed at the focal point of the lens  904 , substantially collimating light exiting from the fiber, or allowing collimated light entering the front of the lens to be focused into the fiber with minimal loss. 
     This alignment may be done by launching laser light into the fiber at the opposite end to the ferrule/rear alignment housing end. The launch is done through a 1×2 splitter to allow monitoring of the power returning into the fiber. The collimator is positioned in a fixture with the exit beam perpendicular to a gimbal mounted mirror which reflects the light back into the lens, where it is focused and enters the launch fiber. This light passes through the 1×2 fiber optic splitter to be detected by a power meter. The fiber ferrule located in the rear alignment sleeve is moved in the longitudinal direction to maximize the power returning into the power meter, thus indicating the point of best focus. At the point of best focus, ferrule/rear housing interface is bonded together. This bonding may be by crimping, tightening a screw, epoxied, or any mechanical bonding technique. Epoxy used may be UV cured, heat cured. 
     The front of the lens holder  906  is spherical and is placed into the rear of the front alignment sleeve  508 . The interface substantially aligns the two axes (i.e., the two axes are coincident), the first being the optical axis of the assembly containing the rear alignment sleeve, lens, fiber and ferrule and the second being the mechanical centerline axis of the outside diameter of the front section of the front alignment sleeve. The two axes are aligned by supporting the outside diameter of the front section of the front alignment sleeve in a V groove pointing to a reference collimator, autocollimator or other means indicating when the optical beam is parallel to the V groove sides. The angle between the front and rear axes are adjusted using micropositioners attached to the rear housing assembly until the two axes are aligned. 
     Referring back to  FIG. 9 , housing  910  houses sleeves  902  and  508 , lens  904  and lens holder  906 . Housing  910  may be a cylindrical shaped tube. More specifically, a rear end portion  931  of housing surrounds a front portion  941  of sleeve  902 . In some embodiments an outer ring  920  (a.k.a., release collar  920 ) surrounds a front end portion  921  of housing  910 . Also, an inner ring  912  may be housed in the front end portion  921  of housing  910 . 
     Referring now to  FIG. 12 ,  FIG. 12  illustrates an embodiment of fiber optic connector  202 . This embodiment is similar to the embodiment of connector  204  shown in  FIG. 9 . Like the embodiment shown in  FIG. 9 , the embodiment shown in  FIG. 12  includes an optical assembly that includes: lens  904 ; a lens holder  1206  in which the lens is disposed; and an optical fiber holder  1204  (e.g., a ferrule) attached to an end of an optical fiber  1299 . The optical fiber holder  1204  is configured and positioned such that light exiting the end  1295  of the optical fiber will be received by the lens  904 . As shown in  FIG. 12 , light exiting end  1295  of fiber  1299  will travel through a channel  1288  of holder  1204 . The lens  904  is positioned and configured to collimate light exiting the end of optical fiber holder  1204  and received by the lens  904 . For example, the tip  1285  of holder  1204  is positioned at the focal point of lens  904 . The optical assembly has an optical axis along which the collimated light will travel. This optical axis is substantially coincident with the longitudinal access of channel  1288 . 
     As further shown in  FIG. 12 , connector  202  includes an elongate hollow alignment sleeve  1208  having a centerline axis (a.k.a., longitudinal axis) extending from one end  1271  of the sleeve  1208  to the other end  1272  of the sleeve  1208 . Sleeve  1208  is connected to the optical assembly so that lens  904  is positioned between the tip  1285  of optical fiber holder  1204  and end  1271  of alignment sleeve  1208 . The centerline axis of the alignment sleeve  1208  is coincident with the optical axis of the optical assembly so that the collimated light will enter the hollow alignment sleeve at end  1271  and exit the sleeve at end  1272 . 
     As further shown in  FIG. 12 , optical assembly may be housed in a housing  1211 . As shown, housing  1211  may include an inner housing tube  1202 , a front outer housing tube  1210 , and a rear outer housing tube  1292 . As shown, tube  1202  may have threads on an outer surface thereof that engage with threads formed on an inner surface of tube  1210 , and rear tube  1292  surrounds a rear portion of tube  1202 . Like the connector shown in  FIG. 9 , the connector shown in  FIG. 12  may include lock ring  912 , which may be retained in the front portion  1221  of tube  1210 . Lock ring  912  is designed to engage with a retention groove of a counterpart connector (e.g., connector  102 ). A release collar  1220  may be positioned so that it surrounds front portion  1221  and contacts lock ring  912 . Release collar  1220  functions to disengage lock ring from the retention groove of the counterpart connector. 
     Referring now to  FIG. 13 ,  FIG. 13  illustrates another embodiment of fiber optic connector  204 . Fiber optic connector  204  shown in  FIG. 13  is similar to connector  204  shown in  FIG. 9  and connector  202  shown in  FIG. 12 , but connector  204  shown in  FIG. 13  does not include the lock ring  912  or release collar  920 . For example, in the embodiment shown, connector  204  includes the optical assembly of connector  202  and alignment sleeve  508 , and includes a housing  1311  that includes an inner housing tube  1602 , a front outer housing tube  1310 , and a rear outer housing tube  1392 . As shown, tube  1602  may have threads on an outer surface thereof that engage with threads formed on an inner surface of tube  1310 , and rear tube  1392  surrounds a rear portion of tube  1602 . Front outer housing  1310  differs from front outer housing  1210  in that housing  1310  includes a retention groove  1311  formed in a front portion  1321  of housing  1310  for receiving a retention spring of a counterpart connector (e.g., connector  104 ). 
     Referring now to  FIG. 14 ,  FIG. 14  further illustrates an embodiment of alignment sleeve  508 . As shown in  FIG. 14  a ring  1402  is connected to an end  1471  of the alignment sleeve. Ring  1402  may be integrally connected to sleeve  508 . Ring  1402  and sleeve  508  form a cavity  1404 . As shown in  FIG. 13 , the portion of lens holder  1206  in which lens  904  is disposed is positioned in the cavity  1404 . In some embodiments, sleeve  508  has a length between about 1 and 2 inches and its outer diameter ranges between about 0.04 and 0.12 inches. In some embodiments, sleeve  1208  is identical to sleeve  508 . 
     Referring now to  FIG. 15 ,  FIG. 15  illustrates jack  100  with a low-profile cover  1502  installed. Low profile cover  1502  functions to enclose the reflector  110 , reflector holder  105 , and other components of the jack  100 . In the embodiment shown, cover  1502  also serves as an attachment point for the rear ports  102  and front ports  104 , which each have a portion that passes through an aperture in a rear end and front end of the cover, respectively. The cover  1502  may be attached to the jack base  106  by screws and held in place by alignment pins. 
     Referring now to  FIGS. 16 and 17 ,  FIGS. 16 and 17  illustrate that jack  100  may further include one or more retention clips  1602 . Each retention clip being positioned adjacent a rear port  102  or front port  104 . Each retention clip is designed to press a front portion of a fiber optic connector to base  106 . For example, when a user mates fiber optic connector  202  with port  102   a  the front alignment sleeve  508 , 1208  of the fiber optic connector  202  passes through the port and into the jack base  106 , and the clip  1602  positioned adjacent port  102   a  will exert on connector  202 &#39;s alignment sleeve  508 , 1208  a force in the direction of base  106  (i.e., a downward force), thereby securing the alignment sleeve and assuring that the alignment sleeve will be aligned correctly within jack  100 . 
     Referring now to  FIG. 18 ,  FIG. 18  shows a side view of an exemplary retention clip  1602 . As shown, a portion  1802  of the retention clip distal to the point of attachment of clip  1602  to the jack base  106  is positioned directly above groove  102   a . The retention clips  1602  are sized and positioned such that the distance between portion  1502  and the bottom of the side walls of groove  120   a  is slightly less than the diameter of a front alignment sleeve  508 ,  1208 . When a front alignment sleeve  508 ,  1208  is inserted into groove  120   a  via port  102   a  the sleeve will contact the retention clip  1602  and push it upwardly. The retention clip exerts a corresponding downward force which holds the front alignment sleeve firmly in place in the groove but still allows for the fiber optic connector to be removed from the port. 
     Referring now to  FIG. 19 ,  FIG. 19  further illustrates jack  100  according to some embodiments. In the embodiment shown, the retention clips are structured with two tabs  1902   a,b  at the distal end of the retention clip  1602 . In the embodiment shown, the bottom surface of each tab (i.e., the surface that faces groove  120   a ) has protuberance  1911  that extends in the direction of the groove. Accordingly, it is this protuberance  1911  that the alignment sleeve  508 ,  1208  will contact when the alignment sleeve is inserted into the groove  120   a.    
     Referring now to  FIG. 20 ,  FIG. 20  shows a detail view of an embodiment of a rear port  102 . This embodiment of a rear port is comprised of an inner attachment cylinder  2002  and an outer shroud  2004 . The inner attachment cylinder  2002  is configured to accept the front alignment sleeve  1208  of connector  202 . The inner attachment cylinder  2002  is configured with a retention groove  2006  around the circumference of the cylinder which engages with lock ring  912  of connector  202  when connector  202  is mated with port  102 .  FIG. 21  shows a sectional view of an embodiment of a rear port  102  and a connector  202 . This view shows the connector  202  as it is being inserted into rear port  102 . As the connector  202  is connected to rear port  102 , the front alignment sleeve  1208  is inserted into the inner attachment cylinder  2002 . Lock ring  912  is not engaged in retention groove  2006  and the connector slides freely into or out of the rear port  102 .  FIG. 22  shows a sectional view of an embodiment of a rear port  102  and connector  202  with the connector  202  fully inserted to the rear port  102 . Lock ring  912  is fully engaged in retention groove  2006  firmly holding connector  202  in place on rear port  102 . A user may de-mate connector  202  from port  102  by gripping outer ring  1220  and pulling the connector away from the port. This action causes lock ring  912  to disengage from the retention groove. 
     Referring now to  FIG. 23 ,  FIG. 23  shows a detail view of an embodiment of a front port  104 . This embodiment of a front port is comprised of an outer shroud  2302  and includes a pass through hole  2304  on the closed, flat end of the port. The outer shroud  2302  has a groove formed in the inner wall of shroud  2302  in which groove a retention spring  1792  is seated.  FIG. 24  shows a sectional view of an embodiment of a front port  104  and connector  204 . This view illustrates the connector  204  as it is being mated with front port  104 . When the connector  204  is being mated with front port  104  the front alignment sleeve  508  passes through the pass through hole  2304 .  FIG. 25  shows a sectional view of an embodiment of a front port  104  and connector  204  with the connector  204  mated with front port  104 . Once the connector  204  is mated with front port  104 , the retention spring  1792  engages with groove  1311  of connector  204  and exerts an inward radial force on housing  1310  because the inner diameter of spring  1792  is less than the outer diameter of portion  1321  of housing  1310 . This force is sufficient to prevent the connector  204  from accidentally being demated from front port  104 , but still allows the cable to be removed without requiring operating of a release collar or similar mechanism. 
     While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.