Abstract:
Peripheral devices are connected to the receptacle of a central processing unit (CPU) or to a hub using an “A” type universal serial bus (USB) connector plug and receptacle that ensures a positive connection regardless of the relative orientation of the two components. This is achieved mechanically, electronically, or through a combination of both. In one embodiment, the receptacle includes a bidirectional backplane that permits electrical contacts within the receptacle to slide or move in a direction that is perpendicular to the linear direction of the connector and its connecting cables. Another option is to use an orientation sensor such as a pressure transducer which serves to detect the orientation of the plug with respect to the receptacle. Another feature is the use of a multi-layer printed circuit board to cross or reverse the pins in the plug, such as D+ to D− and Power to Ground.

Description:
FIELD OF THE INVENTION 
   The present invention relates to connectors that are used to couple peripheral devices to a central processing unit (CPU), such as a server or a personal computer. More specifically, it relates to a universal serial bus (USB) connector that provides a connection between peripherals and either the CPU or a hub connected to the CPU. 
   BACKGROUND OF THE INVENTION 
   The capabilities of a computer are maximized by utilizing a variety of external peripheral devices that are connected to the computer. This may involve any number of peripherals, such as scanners, printers, digital speakers, modems, compact disk drives, radio frequency device transceivers, video/audio links, MP3 players, hard drives, DVD drives, CD drives, smart card/bar code readers, digital cameras, digital video recorders and speaker amplifiers. One USB port can be used to connect over 100 peripheral devices. The computer can be a personal computer, laptop computer, hand-held computer, work station, server or the like. 
   A USB connector replaces different kinds of serial and parallel port connectors with a standardized plug and port connection. For the successful utilization of a USB connector, the CPU must have an operating system that is USB compliant and that understands it. This permits hot swapping to be done without the need to shut down and reboot the system each time a peripheral device is attached or removed from the CPU. The CPU automatically detects the peripheral device and configures the necessary software. The USB allows several peripheral devices to be connected at the same time. Many CPUs have more than one USB port, and some peripheral devices called USB hubs have additional ports to allow several peripherals to be cascaded or “daisy chained” together. The USB senses that a peripheral requires power and delivers the power to the peripheral. USB Implementers Forum (USB-IF) specifications use the term “USB” to refer to slower speeds of 12 Mbps and 1.5 Mbps for peripherals, such as joysticks, keyboards and mice, and the term “Hi-speed USB” for high speeds of 480 Mbps useful with most other devices, such as digital cameras and CD-ROM burners. 
   Two different types of USB connectors are in common use. One is a type “A” connector, and uses a receptacle that contains four pins in a straight line on one side of a connector plate. Pin #1 is for the signal and pin #4 is the ground connection while pins ##2 and 3 are for the output and input of data, respectively. Another is a type “B” connector, comprising two pins on either side of the receptacle connector plate. The present invention is principally concerned with an improvement in connectors of the “A” type. 
   One method of coupling the connector to the port of a computer or a hub is described in U.S. Pat. No. 5,784,511 wherein a magnetic connector and cable are employed for connecting peripherals to the computer through an infrared computer link. This requires that each unit have a transmitter and a receiver element which communicate through optical fibers without cables. The connector has a shaped surface that ensures correct alignment in the receiving connector slot or port. 
   U.S. Pat. No. 6,424,525 gives details of a device for connecting a plurality of peripherals to a computer, or to a hub which, in turn, interfaces with a computer. The device employs multiple bays, each of which includes separate data and power connections, a rail for alignment of a peripheral in the bay, a visual alignment element and an alignment pin. 
   The USB connector plugs of the prior art can only be successfully inserted into a USB port or receptacle one way. Visually, the orientation is not readily apparent unless viewed directly head-on into the USB connector. Typically, the ports are located on a rear panel of the CPU and are not always readily accessible. Additionally, the port locations may be obstructed or hard to view. Accordingly, one common approach is to provide a USB icon on the plugs to provide tactile feedback in an attempt to facilitate the obtaining of proper orientation. 
   A shortcoming of the prior art is the failure to provide a reliable mechanical coupling of a USB connector with a port of a central processing unit. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to overcome the shortcomings of prior art USB connectors. 
   Another object is to provide a USB connector that can be plugged into a port without the need to visualize the connection process. 
   The present invention relates to a connector (also referred to as a plug) that can be coupled to a port (also referred to as a receptacle) independent of orientation. This is achieved by positioning the USB connector initially in the middle of the receptacle. When inserted into the USB receptacle, the plug is pushed along until the device is fully inserted and the pins are electrically connected to the contacts in the receptacle. A perpendicular backplane in the receptacle is bidirectional so that the USB connector plug can be inserted regardless of its orientation to the receptacle. The connector of the present invention is useful with a USB key, a USB hdd (hard disc drive), USB DVD/DVD and RW/CD/CDRW USB connectors, among others. 
   The invention also relates to a USB connection utilizing an orientation sensor, such as a pressure transducer, to sense the physical orientation of the connector plug with respect to the receptacle. The sensor typically is mounted on or within the receptacle where it is powered by the CPU. However, it is also possible to mount the transducer in the plug. 
   The invention further relates to a computer system including a central processing unit (CPU) and at least one peripheral device connected, either directly or through a hub, to the CPU using a universal serial bus (USB) connection. The connection comprises a plug and a receptacle, including an arrangement for bidirectional connection of the plug with the receptacle. The arrangement can be implemented in hardware or software or a combination thereof. A mechanical arrangement may use a floating contact and may be further implemented so that the contacts in the plug are switched to match the corresponding contacts in the receptacle. Alternatively, the USB connection may have an orientation sensor, such as a pressure transducer, micro switch or optical device to sense the orientation of the connector plug with respect to the receptacle. 
   The invention also relates to a method for using an “A” type USB connector to connect a peripheral device to a receptacle of a host that is either a hub or a CPU. The method comprises the first step of using a bidirectional connector or plug extending from the peripheral device to the receptacle of the host. This is followed by engaging the receptacle with the plug. Finally, the signals are matched through the plug in accordance with established protocol for the USB connector. Alternatively, the signals are matched by the CPU or by a printed circuit board, or by a combination of hardware and software. For example, the signals can be matched using signal switching. 
   The invention also relates to implementation of the invention in software or hardware, or a combination of both. 
   Further, the invention relates to an article of manufacture that comprises a computer usable medium having a computer readable program embodied in said medium. The computer readable program, when executed on a computer, causes the computer to implement the connection of an “A” type USB connector plug to a compatible receptacle by sensing the orientation of contacts of the plug with respect to the contacts of the receptacle, and matching the contacts with one another. 

   
     BRIEF SUMMARY OF THE DRAWING 
     The present invention will now be described with specific reference to the drawings which are provided for illustrative purposes only, and not as a limitation thereof. 
       FIG. 1(   a ) shows a side view, partially in cross section, of a receptacle of a USB connector of the prior art; 
       FIG. 1(   b ) shows an end view of the receptacle of  FIG. 1(   a ); 
       FIG. 1(   c ) shows an assembly of a plug and receptacle, partially in cross section; 
       FIG. 2(   a ) shows a simplified cross sectional view of a receptacle of the present invention; 
       FIG. 2(   b ) is a top detailed view of the receptacle of  FIG. 2(   a ); 
       FIG. 3(   a ) shows a cross-sectional side view of a USB connector receptacle according to the present invention; 
       FIG. 3(   b ) is a top detail view of the receptacle of  FIG. 2(   a ); 
       FIG. 4(   a ) shows the normal connection between the receptacle and the plug of  FIG. 3 ; 
       FIG. 4(   b ) shows the connection between the components wherein the plug is inverted with respect to the receptacle; 
       FIG. 5(   a ) is an elevation in cross section of a further modification of the present invention; 
       FIG. 5(   b ) is a frontal cross sectional view of the modification shown in  FIG. 5(   a ); 
       FIGS. 6(   a ),  6 ( b ) and  6 ( c ) show a variation in which an orientation sensor is used to determine the relative orientation of the component parts of the USB connector; 
       FIG. 7  is a simplified wiring diagram showing normal and inverted receptacle contacts; and 
       FIG. 8  shows a floppy disc, indicative of a computer-readable medium for carrying out the steps of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In more detail, the present invention describes a USB connector comprising a plug and a receptacle wherein the plug is capable of being inserted into the receptacle in either of the two normal planes of orientation. Although the discussion will be directed to a type “A” connector configured with four contacts in a plane, it is to be understood that the invention is not limited solely to that one configuration, but can be used with other pin arrangements, such as a five pin USB type mini-B connection as well. 
   Turning now to the drawings,  FIGS. 1(   a )– 1 ( c ) show a prior art USB device consisting of two components, a receptacle  110  and a connector or plug  140 .  FIG. 1(   a ) shows a side view of the receptacle  110 , partially in cross section, and  FIG. 1(   b ) shows the opening in the front of the receptacle. The receptacle  110  includes a housing  112  having a flange  114 . Within the housing  112  is a contact holder  116  made from a suitable dielectric material. The free end of the holder  116  is beveled as shown or rounded to facilitate engagement with a corresponding plug. Attached to the holder  116  are contacts  118 , numbered 1–4 in  FIG. 1(   b ). Four spring latches  120  are shown in  FIGS. 1(   a ) and  1 ( b ), and are used to hold the plug in place as shown in  FIG. 1(   c ). Here, the plug  140  is shown bonded in an overmold boot  142 . The plug  140  includes an outer shield  144  surrounding a row of four pins, one of which is shown as  146  laminated on the surface of a pin holder  148  made from a suitable dielectric material. As with the free end of the contact holder  116 , the free end of the pin holder  148  is likewise beveled or rounded to facilitate insertion into the receptacle  110 . This rudimentary mating of the two beveled surfaces serves to provide the proper orientation of the connector  130  and the receptacle  110 , but only if and when the two components of the connection are oriented correctly for engagement. It should be noted that each pin  146  electrically mates with one of the four contacts  118  in the receptacle  110 . The plug  140  typically is joined by a shielded cable (not shown) to a suitable peripheral device (not shown). In like manner, the receptacle  110  is joined by cable (not shown) to a hub or CPU, such as a personal computer, laptop or a server (not shown). 
   Turning now to the present invention, attention is directed to  FIGS. 2(   a ) and  2 ( b ) showing, respectively, the side and top of a receptacle  210  embodying features of the present invention.  FIG. 2(   a ) shows a pair of latch clips  220  joined to back plate  226 . The contact holder  216  has a row of contacts  218   a  on the lower surface of the holder  216  and a second row of contacts  218   b  on the upper surface. As viewed in  FIG. 2(   b ), the contact holder  216  slides in a pair of glide tracks  234  molded or machined into the wall of the receptacle housing  212 . This allows the holder  216  to move at right angles to the direction of the plug as it is being inserted into the receptacle. Bias means, such as spring  224 , serves to bias the contact holder  216  against the top of the receptacle housing  212  when the plug is inserted in its normal manner, whereupon the normal contacts  218   a  engage the corresponding pins of the plug. This establishes an electrical connection between the receptacle and a row of contact pins  238   a  at the top of the contact holder  216 . On the other hand, if the plug is inserted into the receptacle in the inverted position, it forces the contact holder downwardly against the spring  224 , until a connection is established between the pins  238   b  at the bottom of the holder and the receptacle. 
   Next, attention is directed to  FIGS. 3(   a ) and  3 ( b ) and  FIGS. 4(   a ) and  4 ( b ) showing a variation of the receptacle of  FIG. 2 . The side view in  FIG. 3(   a ) shows the two latch clips  320  including a back plate  326  having an aperture  328   a . The holder  316  includes two beveled surfaces  319  on the leading edge. The contact holder includes an upper sliding shield  330   a  which includes a pair of pins  332   a , and a lower sliding shield  330   b  which also has a pair of pins  332   b  seen in  FIG. 3(   b ). Viewed from the top, the shields slide in a pair of glide tracks  334  molded or machined into the wall of the receptacle housing  312 . The contact holder  316  is provided with means to move laterally, e.g. at right angles to the direction of insertion of the plug into the receptacle. Spring  324  serves to bias the contact holder  316  against the top of the receptacle housing  312 . 
   The successful mating of the connector with the receptacle is shown in  FIGS. 4(   a ) and  4 ( b ) wherein the same numbers are used as in  FIGS. 3(   a ) and  3 ( b ) to refer to the same component parts. As with the prior art plug, this plug  340  is provided with an insulated pin holder  348  having a single beveled surface  350 . This beveled surface contacts either of the beveled surfaces  318   a ,  318   b  of insulator  316  depending on the relative orientation of the two components. In  FIG. 4(   a ), the plug is in the normal coupling position and biases the lower sliding shield  330   b  toward the back plate  326 , thereby propelling the pins  332   b  through the lower aperture  328   b  in the back plate. On the other hand,  FIG. 4(   b ) shows the plug oriented in the inverted or upside down position. As it is inserted into the receptacle  310 , the beveled surface  350  of the pin holder  348  contacts upper beveled surface  319  on the contact holder  316  and biases the holder downwardly against the spring  324  until contact is made between one of the contacts  318  of the receptacle and one of the pins  346  of the plug. At the same time, the upper sliding shield  330   a  is pushed toward the back plate  326  causing pins  332   a  to engage and to slide into the upper apertures  328   a.    
     FIGS. 5(   a ) and  5 ( b ) show yet another variation of the present invention in which the receptacle  510  uses a contact holder  516 . Isolating ridges  533  are located along the contact holder  516  to prevent the contacts  518  from shorting against one another. The raised ridges  533  electrically isolate the individual contacts  518  from one another as a plug pushes the beveled edge  519  of the contact holder  516  downward against the spring  536  when the plug is in the inverted position. At the bottom of its movement, the contact holder  516  engages the lower contacts  538   b  on the back plane  526 . 
     FIGS. 6(   a ),  6 ( b ) and  6 ( c ) show yet another embodiment of the invention in which an orientation sensor serves to determine the respective orientation of the components (plug and receptacle) of the USB device. In this example, a pressure transducer  660  is used as the sensor. The receptacle  610  is shown with the contact holder  616  joined to the back plate  626 . The holder includes two sets each of four contacts  618 . The transducer  660  is mounted so that it either sees compression as the plug  640  is inserted in the normal manner as shown in  FIG. 6(   c ) or expansion as the plug is inserted in the inverted position as seen in  FIG. 6(   b ). Based on the pressure on the transducer, a signal can then be transmitted to a motherboard or other device to make whatever adjustment may be needed in the circuitry so as to accommodate the orientation of the components of the connector. 
   The invention provides a mechanical implementation. It likewise applies to a reverse pin contact situation, such as D+ to D−, Pwr to Gnd, etc. Below are some of the means for reversing the pins to supply power and signal: 
   (A) Use a multi-layer printed circuit board to cross the pins over between the two sides. Use vias to conduct the signal between the layers. This wiring arrangement is shown schematically in  FIG. 7 . 
   (B) Install a pressure transducer or other type of orientation sensor to detect in which direction the mating surface is being forced, and use that signal to enable the connections for the mating side. This is shown in  FIG. 6 . 
   (C) Construct a USB connector with a sliding channel to allow the center section to move up and down. As the connector moves to one orientation, it will make contact with a set of pins to enable connection to the USB device. 
   (D) Use additional sets of conductors to route all eight contacts to the PCB, and sort it out on the mother board. 
     FIG. 8  shows a computer-readable medium in the form of a floppy disc  800  for containing the software implementation of the program to carry out the various steps of project management according to the present invention. Other machine readable storage mediums are fixed hard drives, optical discs, magnetic tapes, semiconductor memories, such as read-only memories (ROMs), programmable read-only memories (PROMs), etc. The article containing this computer readable code is utilized by executing the code directly from the storage device, or by copying the code from one storage device to another storage device, or by transmitting the code on a network for remote execution. The computer program may be loaded into the memory to configure and to run the program herein described and claimed for execution. The computer program comprises instructions which, when read and executed by the system, perform the steps necessary to execute the steps or elements of the present invention. 
   The present invention meets all electrical, mechanical and environmental compliance standards for USB type “A” connectors. Among others, these include vibration, thermal shock, solderability, flammability, contact resistance and capacitance load. It also complies with EIA 364-13 that defines the maximum mechanical force required for inserting a USB connector and insertion force. A type “A” USB uses a plug or connector that is oriented upstream from the USB peripheral device toward the hub or CPU and a receptacle or receptacles that serve as the downstream output from the hub or the CPU. 
   The present invention can be realized in hardware, software, or a combination of the two. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software could be a general purpose computer system that, when loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which, when loaded in a computer system, is able to carry out these methods. 
   Computer program instructions or a computer program in the present context mean any expression, in any language, code (i.e., pico code instructions) or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following occur: (a) conversion to another language, code or notation; (b) reproduction in a different material form. 
   While the invention has been described in combination with specific embodiments thereof, there are many alternatives, modifications, and variations that are likewise deemed to be within the scope thereof. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations as fall within the spirit and scope of the appended claims.