Abstract:
Electro-optical communications may be facilitated between electrical devices by providing pluggable electro-optic modules. The pluggable electro-optic modules may be pluggingly received within U-shaped electrical connectors associated with printed circuit boards on both the receive and transmit ends. In some cases, the pluggable modules may be plugged in to establish communications and may be removed for repair or replacement.

Description:
BACKGROUND  
       [0001]     Embodiments of the present invention relate to the field of optical systems and more specifically, but not exclusively, to electrical optical communication.  
         [0002]     Many of today&#39;s electronic components are coupled by way of wire cables. Wire cables may be used between computer systems and peripherals such as displays, disk drives, and printers. However, such electrical connections suffer from limitations in transmission speed and signal integrity.  
         [0003]     Cables carrying optical signals and an optical fiber are becoming more popular. Optical signals provide higher speed and superior signal quality, as well as reduced interference from outside electromagnetic energy, in some cases. Optical cables are often connected to components using glue or screw connectors. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]      FIG. 1  is a simplified top plan view of a pair of communicating electro-optical modules in accordance with one embodiment of the present invention;  
         [0005]      FIG. 2  is an enlarged, perspective view of one of the modules shown in  FIG. 1  in position on a printed circuit board in accordance with one embodiment of the present invention;  
         [0006]      FIG. 3  is a perspective view of the embodiment of  FIG. 2  with the electro-optic module removed from the connector body in accordance with one embodiment of the present invention;  
         [0007]      FIG. 4  is a reverse perspective view of the embodiment shown in  FIG. 3 ;  
         [0008]      FIG. 5  is perspective view showing the electro-optical module being plugged into the electrical connector and printed circuit board in accordance with one embodiment of the present invention;  
         [0009]      FIG. 6  is a top plan view corresponding to  FIG. 2 , but after the module has advanced further inwardly, in accordance with one embodiment of the present invention;  
         [0010]      FIG. 7  shows the electro-optic module in the course of being plugged into the connector body in accordance with one embodiment of the present invention;  
         [0011]      FIG. 8  is a top plan view of the device fully plugged within a connector in one embodiment of the present invention;  
         [0012]      FIG. 9  is a partial, enlarged, cross-sectional view taken generally along the line  9 - 9  in  FIG. 8 ;  
         [0013]      FIG. 10  is an exploded, perspective view of one embodiment of the electro-optic device in accordance with one embodiment of the present invention;  
         [0014]      FIG. 11  is an exploded, perspective view of the bottom of the electro-optic device in accordance with one embodiment of the present invention;  
         [0015]      FIG. 12  is an enlarged, cross-sectional view taken generally along the line  12 - 12  in  FIG. 8 ;  
         [0016]      FIG. 13  is a system depiction in accordance with one embodiment of the present invention; and  
         [0017]      FIG. 14  is a more detailed system depiction in accordance with one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0018]     Referring to  FIG. 1 , an optical communication system  10  may include a transmitting electro-optical assembly  12   a  and a receiving electro-optic assembly  12   b . Thus, electrical signals may be received on the pins  18  and converted to optical signals by the electro-optical device  20   a . The optical signals are then sent over the optical cable  14  to the receiving electro-optic assembly  12   b . The receiving assembly includes an electro-optical device  20   b  that converts the received optical signals into electric signals, which may then be transferred to another system through the electrical leads  18 .  
         [0019]     In this way, one electrical system may communicate with another electrical system over an optical communication link. There is no limitation on what types of electrical systems may communicate over such an optical link. Also, the cable  14  is not limited to optical fiber only or just one line, it can be a combination of several electrical lines and optical fibers. As examples, a computer may communicate with other computers or its own peripherals over such a link.  
         [0020]     Each of the devices  20  electrically plug into a U-shaped electrical connector  16 . Thus, plugs on one of the connector  16  and device  20  are received within sockets on the other of the connector  16  and device  20 .  
         [0021]     Referring to  FIG. 2 , the electrical connector  16  may be surface mounted to a printed circuit board  22  associated with an electronic system. As shown in  FIG. 2 , the electro-optic cable  14  communicates by a connector module  56  with a molded lens module  52 .  
         [0022]     The connector  16  includes surface mountable legs  24  that electrically and physically connect by surface mounts to lands  31  on the printed circuit board  22 . A series of connector  16  leads  18  may be surface mounted on bond pads  19  which are part of the printed circuit board  22  in one embodiment. Thus, the electro-optical device  20  may be plugged into an electrical connector  16  that may be surface mounted onto a printed circuit board  22 . This provides for easy plugging engagement. The electro-optical device  20  may be releasably held on the connector  16  by a latch  32 .  
         [0023]     Thus, referring to  FIG. 3 , which shows the assembly of  FIG. 2  with the device  20  removed, a grooved track  26  is provided within a slot  30  that pluggingly receives the device  20 . In addition, the latch  32  includes a cantilevered spring arm with a pin  27  that is releasably engaged within a notch  40  on the connector  16 . Thus, the free end  21  of the latch  32  may be spring biased by its own internal resiliency. Inward force is applied by the latch  32  to engage the pin  27  in the notch  40  in a connector  16 . The pin  27  extends generally transversely to the length of the free end  21 . In addition, an offset section  36  of the latch  32  may engage another notch  42  in the connector  16 . Because of the cammed or angled sides on the offset section  36 , the offset section  36  may releasably engage the notch  42 .  
         [0024]     Similarly, as shown in  FIG. 4 , a series of electrically receiving female socket  29  may be arranged in the connector  16  slot  30  to receive mating electrical elements on the device  20 , once plugged into the slot  30 .  
         [0025]     Referring to  FIG. 5 , the device  20  may be engaged with its lateral flanges  34  arranged to ride within the opposed connector guide tracks  26  in the connector  16 . A cammed leading edge  38  is located on the leading edge of each flange  34 . A slot  46  is defined in the flange  34  in one embodiment. Thus, a plugging relationship may be achieved as the device  20  is moved from right to left in  FIG. 5  so that the electrical pins  48  on the device  20  ultimately engage the receiving plugs  29 .  
         [0026]     As shown in  FIG. 6 , the slot  46 , along the flange  34 , may eventually be engaged by the pin  27 . The slot  46  may have a rounded contour which may have a larger radius than the radius of the end of the pin  27 . Thus, the pin  27  may be spring biased into the slot  46 , but with a forceful pull can be disengaged to allow the device  20  ultimately to be removed.  
         [0027]     In another embodiment, the slot  46  may have a rectangular contour. When trying to pull out the device  20 , the straight edge of the slot  46  will be in contact with the straight edge of the pin  27 . Thus, there is no ramp or rounded contour on the slot  46  for pin  27  to slide out of the slot  46 . Disengagement can only be done by manually deflecting the latch  32  to allow the pin  27  to come out of the slot  46 .  
         [0028]     The engagement between the connector  16  and the device  20  is facilitated by the cammed leading edge  38  of the flange  34  as shown in  FIG. 6 . Initially, the end of the pin  27  is engaged by the edge  38  and cammed outwardly to allow passage of the device  20  and its track  34 . Thereafter, as the device  20  proceeds inwardly into the slot  30 , the pin  27  rides on the facing edge of the flange  34 , as shown in  FIG. 7 .  
         [0029]     Thus, referring to  FIG. 8 , the pin  27  is engaged within a slot  46  in the track  34 . In this position, the device  20  is releasably held within the connector  16  on the printed circuit board  22 . In such a configuration, optical signals inbound to the device  20  may be converted to electrical signals outbound from the device  20  to the printed circuit board  22 . Similarly, inbound electrical signals can be converted into optical signals in the module  52  and passed outwardly through module  56  to the cable  14 .  
         [0030]     If it is desired to remove the device  20  from the connector  16 , either the latch  32  may be manually displaced or, if sufficient force is applied, the device  20  may be disengaged. Then, either the connector or the device  20  and cable  14  may be replaced or repaired during such disengagement.  
         [0031]     Ultimately, upon alignment between the slot  46  and the pin  27 , the pin  27  is shoved into the slot  46  by the natural resiliency of the latch  32 . In this position, the cammed edge  38  may be close to or in contact with the connector  16 . As a result, the device  20  is releasably latched in the connector  16 , as shown in  FIG. 8 .  
         [0032]     The leads  18  have the lower extension  44  and the upper extension  45 . Thus, referring to  FIG. 9 , the leads  18  are pre-assembled to the electrical connector  16 , for example, by a force fit of their upper extension  45  to the slots  51  of the electrical connector  16 . The socket  29  is formed of the space between the lower extension  44  of the leads  18  and the connector  16 . The leads  18  may be held by a snap fit or frictional connection within slots  51  of the electrical connector  16 . This leaves an extension  44  of each lead  18  that extends outwardly. The free end of the extension  44  may be curved so as to make a plugging electrical connection with the pins  48  on the devices  20 . Thus, the device  20  can effectively plug right into the socket  29  of the electrical connector  16  with electrical contact being made between the pins  48  and the extensions  44 .  
         [0033]     Referring to the exploded depiction of  FIG. 10 , the cable  14  extends through the strain relief  58  which is secured to the optical connector module  56 . In fact, the cable  14  extends into the module  56 . The module  56  is engaged within the molded lead frame  50  and, ultimately, plugs into the molded lens module  52 . Thus, the lead frame  50  may be U-shaped in one direction, providing a support surface  55  that mounts and receives the modules  56  and  52 . The molded lead frame  50  also includes the flange  34 , the slot  46 , and the cammed edge  38 , as well as the pins  48 .  
         [0034]     Also formed in the molded lens module  52  is a  45  degree mirror area  66 . A fiber side lens  74  is also formed integrally into the molded lens module  52  in some embodiments. The module  52  may also include locating post  60  to align the modules  52  and  56 .  
         [0035]     As shown in  FIGS. 10 and 11 , the module  56  includes a lower flange  80  on one side and a higher flange  82  on the other side. The module  52  includes a mating higher flange  84  on one side and lower flange  86  on the other side. Thus, the flange  80  is locked under the flange  84  and the flange  86  is locked under the flange  82  when the two modules  52  and  56  are plugged together.  
         [0036]     As shown in  FIG. 11 , locating holes  62  are arranged to be engaged by in a plug fit with the locating posts  60  on the module  52 . A lens array  54  is provided on the molded lens module  52 . Locating posts  64  are provided on the molded lens module  52  for engaging the corresponding holes on the molded lead frame  50  in a vertical engagement. Thus, the molded lens module  52  may be locked on the molded lead frame  50 .  
         [0037]     In one embodiment, as shown in  FIG. 12 , the end  70  of the cable  14  is arranged proximately to an opening in the molded lens module  52 . At an opposed end of that opening is the integrally molded fiber side aspherical lens  74 . However, spherical lenses may also be used. Since the molded lens module  52  is made of a light transparent material, light from the free end  70  passes through the cavity in the module  52  and is focused by the fiber side lens  74  onto an integrally formed mirror  72 . The mirror  72  then reflects the light downwardly, in the case of a receiving embodiment, to the pin diode  81 . The light from the mirror  72  passes through the integral device side aspherical lens  76  also formed as part of the module  52 .  
         [0038]     Conversely, in the case of a transmitter, the element  81  may be a light emitter such as a vertical cavity emitting laser (VCEL). Light from the transmitting element  81  is focused by the lens  76  onto the mirror  72  where it is reflected to pass outwardly through the lens  74  into the free end  70  of the cable  14 . An element  78  may be a driver chip for a transmitter or a receiver chip for a receiver. A glue channel  83  may be provided to glue the module  52  into the molded lead frame  50 .  
         [0039]     Referring then to  FIG. 13 , a system may be formed with a transmitting electro-optical device  12   a , formed on a printed circuit board  22   a , that communicates by a cable  14  with a receiving electro-optical device  12   b  on another printed circuit board  22   b . The printed circuit board  22   b  may have its own electro-optical transmitting device  12   a  that communicates by a cable  14  with the receiving device  12   b  on the printed circuit board  22   a . Thus, electrical systems, components, or peripherals may communicate through their printed circuit boards  22 , the electro-optical devices  12 , and the cable  14  in both a transmit and a receive fashion in some embodiments.  
         [0040]     Referring finally to  FIG. 14 , the printed circuit board  22  on which a device  12  is mounted may include, in some embodiments, a processor  92 , an input/output device  90 , and a system random access memory  94 . These components are coupled by a bus  96 . The bus  96  may, in turn, coupled through electro-optical devices (not shown) with the cables  14 .  
         [0041]     The cables  14  provide optical communications with the printed circuit board  22   b . The printed circuit board  22   b  may be associated with another computer system, a networked device, a server, or a peripheral associated with the printed circuit board  22   a , to mention a few examples. For example, in one embodiment, the printed circuit board  22   a  may provide a computer system that connects to peripherals that include printed circuit boards  22   b.    
         [0042]     References throughout this specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation encompassed within the present invention. Thus, appearances of the phrase “one embodiment” or “in an embodiment” are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be instituted in other suitable forms other than the particular embodiment illustrated and all such forms may be encompassed within the claims of the present application.  
         [0043]     While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.