Patent Publication Number: US-2023162891-A1

Title: Usb transmission cable structure

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a universal serial bus (USB) transmission cable structure. 
     2. The Prior Arts 
     Universal Serial Bus (USB) is a serial port bus standard for connecting computer systems and external devices, and also a technical specification for input and output interfaces. USB has been widely used in information communication products, such as, personal computers and mobile devices, and other related fields. 
     The latest generation of USB is USB 4, and the new generation of physical connectors is USB Type-C. 
     Compared with the earlier USB Type-A and USB Type-B, the USB Type-C connector is characterized by being able to be plugged into the interface in both orientations, and is thinner and smaller in size, which is beneficial for diversifying 3C product designs in pursuit of thinness and light-weight under the trend of sophisticated consumer market. 
     USB 4 is the latest version of transmission specification, which provides the advantages of transmitting data at a higher speed, smart power management, longer life, and more durable. Therefore, combining the USB Type-C connector with the USB 4 transmission specification is a future trend. 
     Based on the requirements of the USB Type-C specification and USB 4 transmission specification, the transmission cable connecting the USB Type-C connector needs to be equipped with more kinds of wires than in the previous versions, such as: high-frequency wire, low-frequency wire, main power wire (VBUS), ground wire (GND), differential signal data wire (D+, D−), cable controller power supply wire (Vconn), auxiliary signal wire (SUB), positive and negative plug detection signal wires (CC), and so on. However, in the USB 4 specification, since the radial cross-section shape of the transmission cable of the existing specification is circular, and the space is small, it will not be possible to arrange the aforementioned multiple existing linear specifications in the circular space while further reducing the signal attenuation (the attenuation value is inversely proportional to the diameter of the wire), so that the length of the signal wire cannot be extended. Therefore, the USB cable cannot be extended to more physical applications that require long-distance transmission of signals. When long-distance transmission is required, attenuation compensation chips must be added, which increases the cost of the product. 
       FIG.  1    shows the state of disposed wires in a conventional USB transmission cable with a circular radial cross-section. The wires include: high-frequency wire A, main power wire (VBUS) B, ground wire (GND) C, differential signal data wire (D+, D−) D, cable controller power supply wire (Vconn) E, auxiliary signal wire (SUB) F, and positive and negative plug detection signal wire (CC) G. Since the thickness of the wire will affect the electrical characteristics, it can be understood that if a variety of wires are packed in a relatively small circular space, the diameter of the wire inevitably cannot be enlarged, so that the signal attenuation during signal transmission cannot be reduced. The transmission cable cannot be designed to be long (the effective transmission distance of the conventional USB 4 20 GHZ transmission cable is only 0.8 m˜1 m), and when long-distance transmission is required, an attenuation compensation chip is also required. 
     SUMMARY OF THE INVENTION 
     A primary objective of the present invention is to provide a way to expand the inner space of the cable body of the USB transmission cable, so that the inner space can be larger than the space of the radial cross-section of the conventional transmission cable to be configured with various wires. Under the premise of signal matching, the cable body can be extended to transmit electronic data and data for a longer distance. 
     To achieve the foregoing objective, the present invention provides a USB transmission cable structure, including: a cable body extending a length along an axial direction and forming an inner space, and the inner space forming an elliptical cross-section in the radial direction of the cable body perpendicular to the axial direction; and a plurality of wires, arranged in the inner space of the cable body. In the present invention, by forming the inner space of the cable body into an elliptic shape, the inner space can be enlarged, so that the diameter of the wire disposed in the inner space can be maximized, so as to reduce the attenuation of the transmission signal per unit length of the wire, and then the transmission cable can be designed to be longer to expand to more physical applications that require long-distance signal transmission without the need for an attenuation compensation chip. 
     Preferably, the ratio of the major axis to the minor axis of the elliptic cross-section is in the range of 1.4:1 to 1.5:1, so as to comply with the specifications of related electronic and electrical equipment. 
     In an embodiment, the outer periphery of the cable body may be formed into an ellipse with the same shape as the inner periphery of the inner space; or the outer periphery of the cable body may be formed differently from the inner periphery of the inner space, such as rectangle or ellipse with different shapes. 
     In an embodiment, the inner space of the cable body forms a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant with the major axis and the minor axis of the ellipse, and the plurality of wires comprise: a first high-frequency wire group arranged in the first quadrant and contacting the cable body; a second high-frequency wire group arranged in the second quadrant and contacting the cable body; a third high-frequency wire group arranged in the third quadrant and in contact with the cable body; and a fourth high-frequency wire group arranged in the fourth quadrant and in contact with the cable body. 
     In an embodiment, each of the high-frequency wire groups comprises: two conductive wires, each having a conductor and an insulating layer covering the conductor, the conductive wires being arranged in contact with each other by the insulating layer; two ground wires, respectively arranged on two opposite sides of the contact between the conductive wires and are in contact with the insulating layers; and an insulating tape, covering the outer surfaces of the conductive wires and the outer sides of the ground wires, the insulating tape comprises an inner layer and an outer layer, wherein the ground wires fill up the space formed between the conductive wires and the inner layer of the insulating tape to support and position the conductive wires to prevent the high-frequency wire group from deformation. 
     In an embodiment, the wires comprise three main power wires, and the main power wires are arranged within a space surrounded by the first to fourth high-frequency wire groups along the elliptical major axis of the inner space. 
     In an embodiment, the wires comprise: a first ground wire disposed in the space between the first high-frequency wire group, the fourth high-frequency wire group and the cable body; and a second ground wire, arranged in the space between the second high-frequency wire group, the third high-frequency wire group and the cable body; a third ground wire, arranged adjacent to the main power wires and located in the first quadrant; and a fourth ground wire, arranged adjacent to the main power wires and located in the second quadrant. 
     In an embodiment, the wires comprise: differential signal data wires, arranged adjacent to the third ground wire and the fourth ground wire, and located in the space between the first high-frequency wire group and the second high-frequency wire group. 
     In an embodiment, the wires comprise: a plurality of low-frequency wires, arranged adjacent to the main power wires, and in the space between the third high-frequency wire group and the fourth high-frequency wire group. 
     In an embodiment, the space surrounded by the differential signal data wire, the first high-frequency wire group, the second high-frequency wire group, and the cable body is provided with a first support; and the space surrounded by the low-frequency wires, the third high-frequency wire group, the fourth high-frequency wire group, and the cable body is provided with a second support, wherein the first support and the second support are for supporting and positioning the wire so that the radial section of the cable body maintains a complete ellipse. 
     Preferably, the first support and the second support may be made of polyethylene (PE), thermoplastic elastomer (TPE), or polytetrafluoroethylene (PTFE). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which: 
         FIG.  1    is a schematic diagram illustrating a correlation between components of a direction control apparatus according to an embodiment of the present invention; 
         FIG.  1    is a schematic view showing the wire arrangement state of a conventional USB transmission cable in a circular inner space; 
         FIG.  2    is a three-dimensional schematic view showing the appearance of the USB transmission cable of the present invention; 
         FIG.  3    is a schematic view showing that the USB transmission cable of the present invention divides the radially elliptical inner space into four quadrants with the major axis and the minor axis; 
         FIG.  4    is a schematic view showing the wire arrangement state of the USB transmission cable of the present invention in the elliptical inner space; and 
         FIG.  5    is a schematic planar view showing an embodiment of the USB transmission cable of the present invention in which the outer periphery of the cable body is formed into a rectangle. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
     As shown in  FIGS.  2  and  3   , the USB transmission cable  1  provided by the present invention includes: a cable body  11 , a connector  12  connected to an end of the cable body  11 , and a variety of wires  2  arranged in a space  110  formed inside the cable body  11 . Wherein, as shown in  FIG.  3   , the cable body  11  is formed to extend a length along an axial direction and an elliptical inner space  110  is formed. More specifically, the inner space  110  forms an elliptical cross-section at the radical plane perpendicular to the axial of the cable body  11 ; furthermore, in an actual embodiment, the outer circumference of the cable body  11  may be formed as an ellipse with the same shape as the inner circumference of the inner space  110 , or depending on appearance design requirement, the outer periphery of the cable body  11  can be formed into a shape different from the inner periphery of the inner space  110 , such as a rectangle (as shown in  FIG.  5   ) or an ellipse with a different shape, which means an ellipse with different ratio of the length of the major axis X to the minor axis Y. Preferably, in the embodiment of the present invention, the ratio of the major axis X to the minor axis Y of the ellipse is in the range of 1.4:1 to 1.5:1 to meet the specifications of related electrical and electronic equipment. Preferably, the length of the major axis X is 7.35 mm, and the length of the minor axis Y is 4.95 mm. 
     In order to facilitate the description of the configuration of the wires  2  inside the elliptical inner space  110  of the cable body  1 ,  FIG.  3    shows a schematic view of dividing the inner space  110  into a first quadrant Al, a second quadrant A 2 , a third quadrant A 3 , and a fourth quadrant A 4  by the virtual major X axis and the minor Y axis of the elliptic inner space  110 . 
     The number and types of the various wires  2  arranged in the inner space  110  within the cable body  11  are determined according to the transmission function to be achieved by the transmission cable  1 , such as charging, data transmission, . . . and other functions. The following is an example of the present invention based on the USB 4 transmission specification and the Type-C connector specification. 
     As shown in  FIG.  4   , in the Type-C connector specification transmission cable with the USB 4 transmission specification, the wire  2  configured in the inner space  110  within the cable body  11  may include: a plurality of high-frequency wire groups  21 , a plurality of total power supply wires  22  (VBUS), a plurality of ground wires  23  (GND), two differential signal data wires  24  (D+, D−), one cable controller power supply wire  25  (Vconn), a plurality of auxiliary signal wires  26  (SUB), and a positive and negative plug detection signal wire  27  (CC) and so on. 
     Wherein, in the embodiment of the present invention, there are four high-frequency wire groups  21 , which are the first high-frequency wire group  21 A, the second high-frequency wire group  21 B, the third high-frequency wire group  21 C, and the fourth high-frequency wire group  21 D; wherein the first high-frequency wire group  21 A is arranged in the aforementioned first quadrant Al and contacts the wall surface of the inner space  110  within the cable body  11 , and the second high-frequency wire group  21 B is arranged in the aforementioned second quadrant A 2  and contacts the wall surface of the inner space  110  of the cable body  11 , the third high-frequency wire group  21 C is arranged in the aforementioned third quadrant A 3  and contacts the wall surface of the inner space  110  of the cable body  11 , and the fourth high-frequency wire group  21 D is arranged in the aforementioned fourth quadrant A 4  and contacts the wall surface of the inner space  110  of the cable body  11 . 
     The present invention is based on two conductive wires  211  forming a set of the high-frequency wire groups  21  for transmitting high-frequency signals; specifically, each high-frequency wire group  21  includes: two conductive wires  211 , a ground wire  212 , a filler  214 , and an insulating tape  213 ; wherein, each conductive wire  211  has a conductor  2111  and an insulating layer  2112  covering the conductor  2111 , the two conductive wires  211  are arranged side by side and the insulating layers  2112  are in contact with each other; the ground wire  212  is arranged on one side of the contact between the two conductive wires  211  and is in contact with the insulating layer  2112 , and the filler  214  is arranged on the other side of the contact between the two conductive wires  211  and opposite to the ground wire  212 . The insulating tape  213  is used to cover the conductive wires  211 , the ground wire  212  and the filler  214 ; wherein, the insulating tape  213  also includes an inner layer  2131  and an outer layer  2132 . The inner layer  2131  may be a metal mesh tape, The outer layer  2132  is an insulating material combined on the outside of the metal mesh belt; the insulating tape  213  is used to cover the two conductive wires  211 , the ground wire  212  and the filler  214 ; that is, by means of the structure of the inner layer  2131  and the outer layer  2132 , the insulating tape  213  protects the two conductive wires  211 , the ground wire  212  and the filler  214 , and shields the external interference on the high frequency signal transmission of the conductor  2111 . Furthermore, in the preferred embodiment of the present invention, the radial cross-sections of the ground wire  212  and the filler  214  are respectively formed to match the shape of the spaces of the side and the other side between the inner surface of the insulating tape  213  and the conductive wires  211  so that the ground wire  212  and the filler  214  are covered by the insulating tape  213  and then fill the space formed between the conductive wires  211  and the inner layer  2131  of the insulating tape  213  so as to support and position the conductive wires  211  to prevent the high-frequency wire group  21  from deformation. 
     In the preferred embodiment of the present invention, the wires  2  may include three main power wires  22  (VBUS). With the elliptic inner space  110  of the cable body  1 , the main power wires  22  can be disposed in a space surrounded by the first to fourth high-frequency wire groups  21 A- 21 D along the major axis X of the ellipse. 
     In the preferred embodiment of the present invention, the wires  2  may include four ground wires  23 , which are a first ground wire  23 A, a second ground wire  23 B, a third ground wire  23 C, and a fourth ground wire  23 D, respectively. In the elliptical inner space  110  of the cable body  1 , the first ground wire  23 A is arranged in the space surrounded by the first high-frequency wire group  21 A, the fourth high-frequency wire group  21 D and the inner surface of the cable body  11 ; the second ground wire  23 B is arranged in the space surrounded by the second high-frequency wire group  21 B, the third high-frequency wire group  21 C and the inner surface of the cable body  11 ; the third ground wire  23 C is arranged adjacent to the main power wires  22  and located in the first quadrant Al; the fourth ground  23 D is arranged adjacent to the main power wire  22  and located in the second quadrant A 2 . 
     In the preferred embodiment of the present invention, the wires  2  may include a differential signal data wire  24 , and the differential signal data wire  24  is arranged adjacent to the third ground wire  23 C and the fourth ground wire  23 D, and is located in the space between the first high-frequency wire group  21 A and the second high-frequency wire group  21 B. 
     In the preferred embodiment of the present invention, the wires  2  may include a plurality of low-frequency wires  28 , which are arranged adjacent to the main power wire  22 , and located in the space between the third high-frequency wire group  21 C and the fourth high-frequency wire group  21 D. 
     In the preferred embodiment of the present invention, the space between the differential signal data line  24 , the first high-frequency wire group  21 A, the second high-frequency wire group  21 B, and the cable body  11  can be provided with a first support  29 A; the space between the low-frequency wires  28 , the third high-frequency wire group  21 C, the fourth high-frequency wire group  21 D, and the cable body  11  can be provided with a second support  29 B. Through the support and positioning effect of the first support  29 A and the second support  29 B on the wires  2 , the radial cross-section of the cable body  11  can maintain a complete ellipse and avoids deforming. The first support  29 A and the second support  29 B can be made of polyethylene (PE), thermoplastic elastomer (TPE) or polytetrafluoroethylene (PTFE). 
     By forming the inner space  110  of the cable body  11  into an ellipse, the present invention can expand the inner space to accommodate more wires with larger wire diameters, so that under the premise of the signal&#39;s matching, the cable body  11  is extended to transmit electronic data for a greater distance. 
     Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.