Miniature connector with improved strain relief for an imager assembly

Information

  • Patent Grant
  • 6494739
  • Patent Number
    6,494,739
  • Date Filed
    Wednesday, February 7, 2001
    23 years ago
  • Date Issued
    Tuesday, December 17, 2002
    21 years ago
Abstract
A miniature wire connector for connecting a transmission cable, defined by a plurality of coaxial cables, to an electronic imager assembly. The connector includes a substantially non-conductive supporting body, and a plurality of grooves formed in the outer surface of the body. At least a portion of each of the grooves includes a layer of conductive plating formed thereon, the grooves retaining at least an axial portion of at least one coaxial cable.
Description




FIELD OF THE INVENTION




The present invention relates to the field of coaxial cable connectors for electronic imager assemblies, and more particularly to features for relieving strain on coaxial cables that connect an electronic imager assembly to a signal processor.




BACKGROUND OF THE INVENTION




Coaxial cables have long been used to connect electrical devices to other electrical apparatus. A typical coaxial cable consists of an outer sheath enclosing a center conductor wire. The center conductor wire carries electrical signals, while the outer sheath provides electrical shielding. When such cables are used, it is well-known to provide some type of strain relief mechanism to alleviate stresses caused in the electrical connection between the coaxial cable wires and an interconnected electrical device. It is necessary that the strain relief provides adequate absorption of any pulling or twisting stresses placed on the coaxial cable wires in order to improve the reliability of the connection and prevent cable disconnection problems.




A particular field in which coaxial cables are used is that of medical or industrial imaging in which imaging devices such as endoscopes or borescopes utilize coaxial cables to connect different electrical devices with a miniature electronic imager and its associated circuitry.




For example, as shown in

FIGS. 1

,


2


, and


12


, a known video endoscopic apparatus


10


, partially shown, typically employs a plurality of coaxial cables


12


to interconnect an electronic imager assembly


20


with a signal processor


13


. The signal processor


13


receives the electrical signals produced by the electronic imager assembly


20


and processes the signals into a suitable video output signal. The signal processor


13


is connected to a video monitor


14


, a video recorder


15


, or other video peripheral device capable of handling the output video signal. The electronic imager assembly


20


shown in the FIGS. includes a miniature electronic imager


22


, such as a CCD, having a transparent window


21


disposed over the image recording surface of the imager. A set of fine pitch imager leads


24


extend from between the miniature imager


22


and the window


21


, extending to a pair of proximally located circuit boards


41


,


42


each having a plurality of electronic components


35


disposed thereupon. A transmission cable


33


includes a plurality of coaxial cables


12


which are used to transmit power to the imager assembly


20


and to transmit an electrical signal, as conditioned by some of the components


35


on the circuit boards


41


,


42


from the imager


22


.




Referring more specifically to

FIG. 12

, the imager assembly


20


is mounted in the distal end of an insertion tube or section


17


relative to a lens system which may include one or more lens elements arranged to focus a target image upon the recording surface of the imager


22


. A series of light emitting ends of a fiber bundle


16


are also disposed in proximity to the distal end of the insertion portion


17


.




A problem is that though electronic imager assemblies have been streamlined and improved, particularly in terms of miniaturization and space savings, there has been relatively little development in providing strain relief for the coaxial cables used with such assemblies. For example, and still referring to

FIGS. 1 and 2

, one method of attaching the plurality of coaxial cables


12


to an electronic imager assembly


20


is provided by solder bonding the ends of each of the center conductor wires


19


of each of the coaxial cables


12


of the transmission cable


33


to traces


34


which are provided on facing surfaces of the pair of elongated circuit boards


41


and


42


which are held in spaced relation from one another. However, in this particular arrangement, the only strain relief is provided by the traces


34


, which include only a relatively small surface area for contacting the center conductor wires


19


of the coaxial cables


12


. However, as electronic imager assemblies continue to shrink in size to meet the target demand for such devices, such forms of strain relief mechanisms have proven inadequate for a variety of reasons.




The above known form of strain relief results in a very stiff distal end since the individual conductors of each coaxial cable


12


are forced apart by a block of resin material


45


and then soldered to the traces


34


in a manner that increases the length of the stiff portion of the assembly. The above solution increases the risk of breaking the connections between the coaxial cable and the assembly when the assembly is bent, twisted or pulled. It would be desirable to decrease the length of this stiff portion, and thereby provide improved flexibility.




Another problem with the above cable interconnection technique is that overall down sizing of endoscopes, borescopes, and other medical and non-medical video inspection instruments has caused the wires of the coaxial cables to become relatively thin and tiny, making these wires even more structurally weak. Utilizing an epoxy or resin to hold these wires is ineffective since their fragility tends to either break the wires completely, or cause them to pull out of the resin when twisted or pulled. Thus, it would also be very desirable to increase the strength of the connection between the wires and the assembly.




A further problem is that available space is limited, meaning conventional means of strain relief, such as clips or interconnect arrays, are highly impractical. Simply put, there is insufficient volume, particularly within an endoscope or borescope, to accommodate such designs. Moreover, there is a general need in the field to minimize the overall size of the insertion portion of these instruments so as to provide improved patient comfort and allow access to small spaces. Thus, it would also be desirable to decrease the volume of space occupied by the wire connector and the electronic imager assembly.




Still a further problem is that the structural components of electronic imager assemblies are also relatively thin and weak. This makes the entire assembly extremely difficult to handle, particularly during assembly of the insertion tube. Thus, there is a need to provide additional structural support to the components of the imager assembly. Moreover, during assembly, there is likelihood that the imager assembly may become misaligned at any time. Even slight misalignments of the imager may render the instrument unsuitable for use. Though applying an epoxy resin in the space between the two hybrid circuit boards prevents the circuit boards from moving apart or closer together, the imager itself is still prone to being misaligned. Thus, it would also be highly desirable to prevent misalignment of the imager itself.




Yet another problem is that the connectors, such as previously described in the above referred to '313 patent, require many manufacturing steps to construct and consist of too many parts. For example, the connectors require hybrid boards that are bonded to a tapered block of resin encapsulating material.




In addition, once the endoscope is assembled, it is an extremely labor intensive, time consuming, and costly process to effect any repairs should they become necessary. As a result, a substantial need has arisen for a connector with an improved strain relief mechanism that is simple to construct and instal, and that will prevent coaxial cables from being detached or broken when placed under tension. Such a feature would vastly improve reliability and help ensure proper operation of the device.




SUMMARY OF THE INVENTION




It is therefore a primary object of the present invention to improve the state of the art of electronic imager assemblies.




It is still a further primary object of the present invention to improve the reliability of coaxial connection mechanisms for imaging instruments, such as endoscopes and borescopes.




It is yet another primary object of the subject invention to improve the integrity of the connection between coaxial cable wires and an electronic imager assembly.




According to a preferred aspect of the invention, a miniature wire connector is provided for relieving strain on coaxial cable wires electrically connected to circuit leads of an electronic imager assembly. The wire connector includes a substantially non-conductive body having a tapered construction. A plurality of grooves are formed on the body in which a layer of conductive plating is formed on at least a portion of each of the grooves. These grooves, formed in the outer surface of the non-conductive body, serve to retain at least a portion of the individual coaxial cable wires. The layer of conductive plating defines a conductive-portion, this plating layer being formed from a metallic or other electrically conductive material. Portions of the coaxial cable wires are placed within and connected to the grooves, with the center conductor wire of the cable being preferably soldered to the conductive-portion, and the conductive shield of the coaxial cable being preferably soldered to a different conductive-portion of the non-conductive body. The conductive shield may be a braided wire, serve wire, foil or plated conductive material.




The miniature wire connector may further include a recess formed in an upper or front surface of the body for fixedly retaining the electronic imager assembly. This recess includes at least one pair of substantially parallel attachment lugs used for bonding to the circuit leads of the electronic imager sensor assembly, and to fix that assembly in a stable position. The attachment lugs have at least one bonding surface for bonding to each of the hybrid circuit leads. The miniature wire connector may further include a cross-groove for providing an electrical connection to the outer sheath of the coaxial cable. The cross-groove is preferably filled with a conductive metal. The body of the wire connector may further include a fixturing hole therethrough for use during wire attachment.




The miniature wire connector is preferably used as part of a video inspection instrument, such as an endoscope or borescope. The video inspection instrument includes a tubular insertion portion capable of being positioned within a tortuous cavity, the instrument further having an optical system disposed within the insertion portion. The electronic imager assembly is disposed in relation to the optical system. According to the invention, the electronic imager assembly includes a miniature electronic imager having an image recording surface arranged to receive a focused optical signal from the optical system, a transparent window disposed over the image recording surface, and a plurality of fine pitch imager leads extending between the image recording surface and the transparent window. As noted above, the miniature wire connector is used to connect a transmission cable to the electronic imager assembly, the transmission cable including a plurality of coaxial cables. The video inspection instrument also may optionally include a plurality of electronic components for operating the miniature electronic imager, wherein at least a portion of the electronic components are substantially planarly disposed in relation to the optical system, thereby providing a compact assembly.




According to a second embodiment of the present invention, a miniature wire connector for connecting a transmission cable to an electronic imager assembly is provided.




The transmission cable is preferably the same design as that described above. In this embodiment, however, the miniature wire connector includes a substantially non-conducting center-conductor termination plate, retaining means defined in the center-conductor termination plate for retaining the electronic imager assembly on a first end surface thereof, and a plurality of grooves disposed along exterior surfaces of the center-conductor termination plate. Each of the grooves include an electrically conductive portion for retaining at least one center conductor wire of at least one individual coaxial cable, a shield termination plate, and a plurality of complementary grooves disposed along exterior surfaces of the shield termination plate for retaining a portion of a coaxial cable.




According to a third embodiment of the present invention, a miniature wire connector includes a substantially non-conducting supporting body. The wire connector, according to this embodiment, further includes retaining means defined in the supporting body for retaining an electronic imager assembly on a first end surface thereof, and a plurality of grooves disposed along exterior body surfaces for receiving at least one center conductor of at least one coaxial cable. According to this embodiment, each of the grooves has an electrically conductive portion for retaining at least a portion of at least one coaxial cable wire.




Another advantage of the present invention is that the layer of conductive plating in each groove of the described wire connector allows a large portion of the center conductor of the coaxial cable to be soldered to the conductive portion. Since more surface area of the center conductor is soldered to the groove, strain relief provided by the present connector is far superior to that of known connectors.




Yet another advantage of the present invention is that a more substantial length of the coaxial cable may be attached to the connector body.




Yet another advantage of the present invention is that the attachment lugs support and fixedly retain the sensor unit, the lugs also maintaining accurate alignment of the electronic imaging assembly.




Yet another advantage of the present invention is that the non-conductive body of the wire connector is formed using a minimum number of manufacturing and assembly steps.




Yet another advantage of the present invention is to allow for further imager assembly miniaturization.




Yet another advantage of the present invention is to allow the use of shielded and non-shielded wires.




These and other objects, features and advantages will be readily apparent from the following Detailed Description which should be read in conjunction with the accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS




For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description of a preferred mode of practicing the invention, read in connection with the accompanying drawings, in which:





FIG. 1

is a partial schematic view showing the component parts of a prior art video endoscope;





FIG. 2

is a side view of the prior art imager assembly of

FIG. 1

;





FIG. 3A

is perspective view of a wire connector having a strain relief mechanism according to a first embodiment of the present invention;





FIG. 3B

shows a variation of the wire connector of

FIG. 3A

;





FIG. 3C

is an enlarged view of the connection of the coaxial wires within the vertical grooves of the wire connector of

FIG. 3A

;





FIG. 3D

is an enlarged view of the connection of the coaxial wires within the vertical and transverse (cross) grooves of the wire connector of

FIG. 3A

;





FIG. 4

is perspective view of a wire connector having a strain relief mechanism according to a second embodiment of the present invention;





FIG. 5

is a bottom view of the wire connector shown in

FIG. 4

;





FIG. 6

is a view of the wire connector shown in

FIG. 4

;





FIG. 7

is a side view of the wire connector shown in

FIG. 4

, just prior to insertion of the cable;





FIG. 8

is a bottom view of the connector according to the second embodiment having a plurality of sockets;





FIG. 9

is a perspective view of a wire connector according to a third embodiment of the present invention;





FIG. 10

is a perspective view of the center-conductor termination plate and the shield terminator plate with the coaxial cable attached according to the third embodiment of the present invention;





FIG. 11

is a side view of the wire connector shown in

FIG. 9

with the coaxial cable attached; and





FIG. 12

is a partial enlarged side elevation of a distal end of a prior art endoscope.











DETAILED DESCRIPTION




The following description is directed mainly to several embodiments, each relating to a video endoscopic assembly. It should be readily apparent, however, that other medical and nonmedical viewing devices, such as industrial borescopes, for example, can also utilize the inventive concepts related herein. In addition, certain terminology is used throughout the course of discussion, such as “lateral”, “distal”, “proximal”, “front”, “interior”, “exterior”, “upper”, “lower” and “rear”, among others. These terms are merely used to provide a frame of reference in regard to the accompanying drawings and are not intended to be limiting of the present invention. For example, and although the following description specifically describes a wire connector having a plurality of formed grooves, it should be noted that a singular groove construction could also be employed which covers the present concept. Moreover, though the following description refers to and describes a specific coaxial cable, it should be appreciated that the inventive concepts similarly apply to other types of cables such as single conductor cables.




As described in concurrently filed and copending application Ser. No. 09/777,134, incorporated herein by reference, there is a general need to minimize the overall size of the insertion portion of a video inspection instrument in order to provide greater comfort to the patient or to allow improved access to targets whose access has been previously limited due to size limitations. To solve this problem, the above reference discloses an electronic imager assembly which includes a miniature solid state imager having an image recording surface that is arranged to receive a focused optical signal from an optical system. A transparent window is mounted in overlaying fashion over the image recording surface. A plurality of fine pitch leads extend outwardly from opposing sides of the imager from between the imager and the window. Due to the flexibility of the fine pitch leads, a number of connected electrical components permits space-saving arrangements of at least some of the components adjacent the lens cell in a distal relationship relative to the imager assembly. The above electronic imager assembly having the leads extending between the window and the image recording surface is referred to as a TAB imager assembly. An example of this form of imaging assembly is shown in

FIGS. 1 and 2

, and is also described in commonly assigned U.S. Pat. Nos. 5,754,313 and 5,734,418, each of which are herein incorporated by reference in their entirety.




This form of electronic imager assembly inspired the inventors to develop the improved miniature wire connector according to the present invention. These connectors are preferably used for connecting a transmission cable to a TAB electronic imager assembly, for example, the one depicted in

FIGS. 1 and 2

. The transmission cable includes a plurality of coaxial cables, each cable being connected by the wire connector to the electronic imager assembly. Any type of coaxial cable could be used; however, the coaxial cables


12


used in the preferred embodiment preferably including a center conductor wire


19


, an electrical insulator layer


43


disposed coaxially around the center conductor wire


19


, a layer of conductive shielding


44


coaxially surrounding the insulator layer, and an insulative jacket


48


which coaxially surrounds the conductive shielding.




Referring to

FIG. 3A

, there is illustrated a first embodiment of a one-piece miniature wire connector


60


in accordance with the present invention.




The wire connector


60


includes a substantially non-conductive body


62


having a plurality of exterior parallel grooves


64


, and a layer of conductive plating


66


formed on at least a portion of each of the grooves. The non-conductive body


62


is preferably molded as an integral or one-piece member in which the parallel grooves


64


can be created by the mold or can be later formed by grinding or other known methods. One end of the non-conductive body


62


preferably has a tapered construction which allows the individual coaxial cables


12


of the transmission cable


33


to fall along a natural path on the outside of the supporting body


62


. This arrangement reduces the stiffness of the entire assembly which results in less strain on the cables and helps prevent them from breaking during use.




The grooves


64


extend along a portion of the length of the supporting body


62


, though depending on the application the grooves may alternately other or the entirety thereof, the grooves serving to retain at least an axial portion of the individual coaxial cable wires. Preferably, the coaxial cables


12


lie within the groove


64


such that a corresponding cable is at least partially embedded in the non-conductive body


62


. The layer of conductive plating


66


defines a conductive-portion, the layer being preferably formed from a metallic material, although any known electric conductor could be utilized. One purpose of the conductive plating layer


66


is to provide a connection that carries an electrical signal between the coaxial cable wire


12


and the hybrid leads of the imager assembly. Another purpose of the conductive plating layer


66


preferably takes the form of a printed circuit that electrically connects the respective conductive shields. The above-described layer


66


also provides a large bonding surface for the solder used to join the coaxial cables to the conductive portion of the supporting body


62


of the wire connector


60


. A pair of cross grooves


68


(only one of which is shown in

FIGS. 3A

,


3


C and


3


D) extend transversely at the proximal end of the grooves


64


. These cross grooves


68


may have a conductive layer


66


also, but vertical grooves and cross grooves do not have connecting conductive layers unless it is desired.




The miniature wire connector


60


preferably includes a recess


79


formed in an upper surface of the supporting body


62


for fixedly retaining an electronic imager assembly


70


relative to the upper surface of the body. The electronic imager assembly


70


shown herein includes a cubic supporting block


72


comprising circuit boards


73


, some of each of which include electronic components (not shown) disposed on exterior surfaces thereof. Additional details relating to the electronic imager assembly are provided in commonly assigned U.S. Ser. No. 09/777,134 previously incorporated by reference.




This recess


79


is preferably defined by at least one pair of substantially parallel attachment lugs


74


, each of which of each includes interior facing bonding surfaces


76


used for bonding to the hybrid circuit leads


75


of the imager assembly


70


. These bonding surfaces


76


are preferably formed as printed circuits. The grooves


66


extend upwardly along the outer surface of the supporting body


62


and terminate at the pair of attachment lugs


74


. The interior facing bonding surfaces


76


thus provide an electrical path between the grooves


66


and hybrid circuitry (such as an amplifier) located on the circuit boards


73


of the imager assembly


70


. The interior facing bonding surfaces


76


also serve to hold the imager assembly


70


in position by attachment to the hybrid circuit leads


75


. In the meantime, fine pitch imager leads


24


extending from between the imager and transparent window are also attached to the circuit boards


73


of the mounting block


72


. The recess


79


is sized to be substantially identical in shape to the imager assembly


70


, thereby allowing the attachment lugs


74


to securely fix the imager assembly in position and even further prevent movement of the imager assembly. Similarly, it should be realized that the recess


79


can define any geometrical shape useful for securely fixing the imager assembly


70


in position. Securely anchoring the imager assembly


70


is critical in order to maintain focus of the imaging instrument.




A variation of the wire connector


80


having a non-conductive supporting body


81


is shown in FIG.


3


B. For the sake of clarity, similar parts are herein labeled with the same reference numerals. More particularly and according to this version, the body


81


includes a plurality of exterior grooves


82


, each of the exterior grooves according to this embodiment including a transverse separating cross-groove


86


. Using this construction, the exterior grooves


82


are therefore separated into two regions, namely, upper groove regions


90


which are attached to the center conductor wires, and lower groove regions


94


used for attaching a ground braid of each coaxial cable. Alternatively, the cross-groove


86


can be filled with a conductor to form a grounding bus which is used to ground the conductive grounding braid of the coaxial cable (not shown in this

FIG. 3B

, but clearly shown in

FIGS. 3A and 3C

with regard to the wire connector


60


).




Referring to

FIGS. 3A and 3B

, each of the non-conducting supporting bodies


60


,


80


may further include a lateral fixturing hole


98


extending through the entirety of the body for use during wire attachment. This lateral fixturing hole


98


serves a variety of functions, including storage of electrical components or alternate use in conjunction with a fixturing pin (not shown) to provide anchoring of the supporting body within the insertion portion of a videoized instrument.




In operation, and referring to

FIGS. 3A and 3C

, part of the insulating jacket


48


of the coaxial cable


12


is stripped away to expose the individual conductive shield


44


. The insulative jacket


48


tightly holds the individual conductive shield


44


together. Portions of the coaxial cables


12


are then placed within and connected to the grooves


64


. As discussed above, the center conductor wire


19


of each cable


12


is preferably soldered to the conductive-portion


66


, while the insulative jacket


48


is preferably attached to the non-conductive portion of the outer surface of the supporting body


62


. By soldering the center conductor wire


19


to the conductive- portion


66


of the wire connector


60


, a greater surface area of the center conductor wire


19


is soldered.




When attached, the center conductor wire


19


of each coaxial cable


12


extends slightly past the end of the supporting body


60


, and may also be soldered to the adjacent hybrid leads


75


to connect the leads to a signal processing portion of the unit. The hybrid circuitry typically includes amplifiers that drive the image signals along the transmission cable


33


to the signal processing portion. If necessary, however, the conductive shield


44


can also be soldered to the transverse cross groove


68


which serves as a grounding bus for each of the conductive shielding portions, as shown in FIG.


3


D.




As previously noted, this embodiment of the present invention is advantageous in that a one-piece conductive portion has a layer of conductive plating along each groove


64


to allow the center conductor wire


19


to be soldered to the conductive portion


66


. Soldering the wires


19


provides strain relief far superior to that of known connectors. Moreover, the imager assembly


70


is fully retained by the wire connector


60


. The attachment lugs


74


of the supporting body


62


of the described wire connector


60


maintain accurate alignment of the imager assembly


70


. Moreover and as noted above, the tapered design of the supporting body


62


allows each individual coaxial cable


12


to fall along the outer surface of the supporting body more naturally. Because the grooves


64


allow each entire coaxial cable


12


to rest within the outer surface of the supporting body


62


, and further because the imager assembly


70


is disposed on part of the supporting body


62


, the region where the center conductor wire


19


connects to the imager, the assembly is less stiff and therefore, has greater flexibility. The design also helps to prevent the center conductor wire


19


from becoming detached or separated, and strain placed on the coaxial cables


12


is substantially relieved. At the same time by tapering one end of the supporting body


62


, the stiffness of each coaxial cable


12


is substantially reduced. As a result, any coaxial cable connections are less likely to break while the attached imager assembly


70


is less likely to shift or become misaligned.




Referring to

FIGS. 4-8

, there is illustrated a second embodiment of a miniature wire connector


108


in accordance with the present invention. According to this embodiment, the miniature wire connector


108


includes a substantially non-conducting supporting body


112


, the body having retaining means


116


for retaining an electronic imager assembly on a first end surface


122


thereof, and a plurality of exteriorly disposed grooves


124


extending along exterior surfaces


128


of the body. Each of the grooves


124


have an electrically conductive portion


132


for retaining at least a portion of at least one coaxial cable wire.




The tapered, substantially non-conducting supporting body


112


includes at least one socket


136


for receiving at least one center conductor of a coaxial cable, and preferably includes a plurality of sockets


138


as shown in

FIGS. 4

,


5


, and


8


. The retaining means


116


advantageously allows for axial adjustment of a lens cell with respect to the first end surface to focus the imager. The socket


136


can be any known means for connecting or terminating a coaxial cable. As shown in

FIG. 8

, a similar connector may also include a socket


138


for each center conductor. The sockets


138


can further include a locking or retaining mechanism for attachment to the outer sheath or conductive shielding of the coaxial cable to help ensure that the center conductor remains connected within the socket.




Referring to

FIGS. 9-11

, a third embodiment of a miniature wire connector


140


includes a substantially non-conducting center-conductor termination plate


144


, and retaining means


148


defined on exterior edges of the plate


144


for retaining an electronic imager assembly


150


thereon. A plurality of grooves


152


are disposed along the exterior surfaces of the center-conductor termination plate


144


. Each of the grooves


152


have an electrically conductive portion


156


for retaining at least one center conductor wire of at least one individual coaxial cable.




A shield termination plate


160


having a plurality of adjacent grooves


164


disposed along exterior surfaces


168


retains an axial portion of a corresponding coaxial cable. The plurality of adjacent grooves


164


each retain the outer sheath of the coaxial cables in the connector. An insulating spacer plate


170


may optionally be positioned between the substantially non-conducting center-conductor termination plate


144


and the shield termination plate


160


. As shown in

FIGS. 10 and 11

, each of the adjacent grooves


164


may have an electrically conductive portion


174


for grounding the conductive shielding of the cable. Each of the adjacent grooves


164


may be electrically connected to ground via a grounding pin


172


connected between the substantially non-conducting center-conductor termination plate


144


and the shield termination plate


160


. A surface


164


of the shield termination plate


160


has at least one grounding bus


168


thereon for terminating the conductive shielding


44


. This grounding bus


168


is preferably printed on the shield termination plate


160


as a printed circuit, which electrically connects the conductive shield


44


of each coaxial cable.




Part List for FIGS.


1


-


12








10


video endoscopic apparatus






12


coaxial cables






13


signal processor






14


video monitor






16


fiber bundle






15


video recorder






17


insertion tube or section






18


lens system






19


center conductor wires






20


electronic imager assembly






21


transparent window






22


miniature imager






24


imager leads






31


protective strip






33


transmission cable






34


traces






35


electronic circuit components






41


circuit board






42


circuit board






43


insulator layer






44


conductive shield






45


epoxy block






48


insulative jacket






60


wire connector






62


supporting body






64


grooves






66


conductive layer






68


cross groove






70


imager assembly






72


cubic supporting block






73


circuit boards






74


attachment lugs






75


hybrid leads






76


bonding surfaces






79


recess






80


wire connector






81


supporting body






82


grooves






84


recess






86


cross-groove






90


upper groove regions






94


lower groove regions






98


lateral fixturing hole






108


miniature wire connector






112


supporting body






116


retaining means






120


imager assembly






122


first end surface






124


grooves






128


exterior surfaces






132


conductive portion






136


socket






138


socket






140


miniature wire connector






144


termination plate






148


retaining means






150


imager assembly






152


grooves






156


conductive portion






160


shield termination plate






164


adjacent grooves






168


exterior surfaces






170


insulating spacer plate






172


grounding pin






174


conductive portion




While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawings, it will be understood by one skilled in the art various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.



Claims
  • 1. In combination, a wire connector connecting a plurality of coaxial cables to an imager assembly, each coaxial cable comprising a center conductor wire, and an insulative jacket coaxially aligned around the conductor wire, the wire connector comprising:a substantially non-conductive supporting body; and a plurality of grooves formed in an outer surface of the supporting body, the grooves retaining at least an axial portion of a coaxial cable, wherein at least a portion of each groove includes a conductive-plating layer, said supporting body including a recess formed in one surface of the supporting body that supports the imager assembly, said recess including at least one pair of substantially parallel attachment lugs for bonding circuit leads from the imager assembly and for fixedly retaining said imager assembly therein.
  • 2. The combination as recited in claim 1, wherein the supporting body includes a through fixturing hole.
  • 3. The combination as recited in claim 1, wherein the layer of conductive plating is metallic.
  • 4. The combination as recited in claim 1, wherein the substantially parallel attachment lugs have at least one bonding surface for bonding to the circuit leads of the imager assembly.
  • 5. The combination as recited in claim 1, wherein the center conductor wire is soldered to both the conductive plating layer and the circuit leads of the imager assembly.
  • 6. The combination as recited in claim 5, further including a transverse groove for grounding conductive shielding coaxially disposed and surrounding the insulator layer which surrounds the center conductor wire.
  • 7. The combination as recited in claim 6, wherein the transverse groove is filled with a conductive material.
  • 8. The combination as recited in claim 7, wherein the conductive shielding is soldered to the transverse groove.
  • 9. A video inspection instrument comprising:a tubular insertion portion capable of being positioned within a tortuous cavity; an optical system disposed within the insertion portion; an imager assembly disposed in relation to the optical system, said imager assembly including a miniature electronic imager having an image recording surface arranged to receive a focused optical signal from the optical system, a transparent window disposed over the image recording surface, and a plurality of fine pitch leads extending between the image recording surface and the transparent window; a miniature wire connector for connecting a transmission cable to the imager assembly, the transmission cable comprising a plurality of coaxial cables, each of the coaxial cables including a center conductor wire, an electrical insulator coaxially disposed around the center conductor wire, conductive shielding coaxially surrounding the electrical insulator, and an insulative jacket coaxially surrounding the conductive shielding, the wire connector comprising a substantially non-conductive supporting body, a plurality of grooves formed in the outer surface of the supporting body, the grooves retaining at least an axial portion of at least one coaxial cable wire, wherein at least a portion of each of the grooves includes a formed layer of conductive plating and a recess formed in an upper surface of the supporting body, the recess being formed on a distal surface of the supporting body and including at least one pair of substantially parallel attachment lugs for fixedly retaining the imager assembly within said recess; and a plurality of electronic components for operating the miniature electronic imager, wherein at least a portion of the electronic components are substantially planarly disposed in relation to the optical system, thereby providing a compact assembly.
  • 10. In combination, a wire connector providing strain relief to at least one transmission cable interconnected to a TAB imager assembly, the at least one transmission cable comprising a plurality of coaxial cables, the coaxial cables each comprising a center conductor wire, an electrical insulator around the center conductor wire, conductive shielding surrounding the insulator, and an insulative jacket around the braiding , the connector comprising:a substantially non-conducting supporting body; a recess defined in the supporting body fixedly retaining said imager assembly on a first end surface thereof; and a plurality of grooves disposed along exterior surfaces of the supporting body, each of the grooves having an electrically conductive portion that retain at least a portion of at least one coaxial cable wire.
  • 11. The combination as recited in claim 10, wherein the substantially non-conducting supporting body includes at least one socket for receiving at least one center conductor of at least one coaxial cable.
  • 12. The combination as recited in claim 11, wherein the substantially non-conducting supporting body includes a plurality of sockets.
  • 13. The combination as recited in claim 12, wherein the retaining means allows axial adjustment of a lens cell with respect to the first end surface relative to the imaging assembly.
  • 14. A miniature wire connector connecting a transmission cable to a TAB imager assembly, the transmission cable comprising a plurality of coaxial cables, the coaxial cables each comprising a center conductor wire, an electrical insulator around the center conductor wire, conductive shielding surrounding the insulator, and an insulative jacket around the braiding, the connector comprising:a substantially non-conducting center-conductor termination plate; retaining means defined in the center-conductor termination plate for retaining said TAB imager assembly; a plurality of grooves disposed along exterior surfaces of the center-conductor termination plate, each of the grooves having an electrically conductive portion for retaining at least one center conductor wire of at least one individual coaxial cable; a shield termination plate adjacent to said center-conductor termination plate; and a plurality of adjacent grooves disposed along exterior surfaces of the shield termination plate for retaining a portion of the at least one coaxial cable.
  • 15. The miniature wire connector as recited in claim 14, further comprising an insulating spacer plate positioned between the substantially non-conducting center-conductor termination plate and the shield termination plate.
  • 16. The miniature wire connector as recited in claim 14, each of the adjacent grooves having an electrically conductive portion for retaining at least a portion of at least one conductive shielding, each of the adjacent grooves being electrically connected to a ground via a grounding pin connected between the substantially non-conducting center-conductor termination plate and the shield termination plate.
  • 17. The miniature wire connector as recited in claim 16, wherein a surface of the shield termination plate has at least one grounding bus thereon for terminating the conductive shielding of the coaxial cables.
  • 18. A videoized instrument system comprising:a video instrument having an insertion portion capable of placement within a cavity; a lens system mounted in the distal end of the insertion portion; a fiber optic bundle having a plurality of light emitting ends disposed in proximity to the distal end of the insertion portion, said lens system being arranged for focusing an image of a target onto an imager assembly, said imager assembly including: a transparent window mounted over a miniature video imaging element, a first set of imager leads passing outwardly from between the miniature video imaging element and the transparent window to one side of the package and a second set of imager leads passing outwardly from between the miniature video imaging element and the window to the other side of the unit; a miniature wire connector for connecting a transmission cable to said imager assembly, the transmission cable comprising a plurality of coaxial cables, each coaxial cable comprising a center conductor wire, an electrical insulator around the center conductor wire, conductive shielding surrounding the insulator, and an insulative jacket around the shielding, the wire connector comprising a substantially non-conductive supporting body, a plurality of grooves formed in the outer surface of the body, the grooves retaining at least an axial portion of at least one coaxial cable wire, wherein at least a portion of each of the grooves includes a layer of conductive plating formed thereon, and a recess formed in an upper surface of the supporting body, the recess being formed on a distal surface of the supporting body and including at least one pair of substantially parallel attachment lugs for fixedly retaining the imager package within said recess; and supporting means for supporting at least some of the electronic components within the insertion portion.
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