Abstract:
A slip ring assembly for use in a rotational camera. The camera has a rotating plate portion and a stationary base. The assembly comprises a housing, the housing having a body with a longitudinal axis, a top end and a bottom end. The top end of the housing includes an inner cylinder protruding therethrough, and upon the cylinder, a plurality of connectors rotationally coupled to the rotating portion of the camera. The second end of the housing is affixed to the stationary portion of the camera. The top end and the bottom end of the housing rotate with respect each other. The slip ring assembly acts as a connector, joining the rotational and the stationary portions of the rotational camera. The present invention minimizes component wear in the camera&#39;s stationary base since the end of the assembly in the stationary portion and all of the wires and electrical components coupled to it remain stationary during rotation of the camera. By eliminating the rotation of electrical components and wiring, less component wear occurs and the wiring is less likely to become tangled within the camera&#39;s stationary portion during rotation of the upper, rotating portion of the camera.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is related to and claims priority to U.S. Provisional Application Ser. No. 60/334,800, filed Nov. 30, 2001, entitled REMOTE CONTROLLED CAMERA SYSTEM, the entirety of which is incorporated herein by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     n/a 
     FIELD OF THE INVENTION 
     The present invention relates to rotating device platforms, and in particular, to improved features for rotatable, titltable camera positioning systems. 
     BACKGROUND OF THE INVENTION 
     Many configurations are known in the art for rotating and tilting a movable camera. Typical devices for moving a camera include pan and tilt devices and dome drive devices. Both pan and tilt devices and dome drive devices operate to accept control signals to move a camera to view a desired location. The prior art devices are comprised of a complex assembly of multiple parts which require great expenditures of labor for construction. In such arrangements, multiple parts lead to inefficiencies in assembly as well as failure during operation. 
     During the operation of the rotating camera it is necessary to provide an electrical connection between a stationary base component and a rotating base component of the camera in order to send and receive electrical signals from components within the rotating base component, such as tilt motors, focus motors and zoom motors, and to relay electrical signals from the camera back to the stationary base. Prior art systems and methods of constructing a flexible, rotatable, electrical connection between the stationary and rotatable components of a camera typically use sliding electrical contacts or integral slip rings as are known in the art. 
     A typical prior art rotating camera base uses a slip ring component typically configured with wiring harnesses attached to a first end and a second end of the slip ring component. The use of such wiring harnesses creates several attendant disadvantages. The use of extended wires in a sensitive electrical system creates electrical noise interference due to the electromagnetic fields created through the wires. In such a situation it becomes necessary to insulate or shield the electrical wires to reduce the electromagnetic field produced thereby. One such method of insulation of shielding is to use ferrite beads to break the magnetic field and thereby reduce electromagnetic current interference with other electrical systems within the components. The manufacture and installation of multiple wiring harnesses using multiple ferrite beads results in increased materials expenses, as well as increased labor expenses. Further, the use of insulation and shielding is an inadequate solution to the problem of electrical interference. 
     Other prior art rotating camera systems use a multiple fastener technique to attach the slip ring component to the stationary component. This increases both material costs and assembly costs while further complicating assembly and repair of the unit. For example, a typical prior art device consists of at least six discrete components: a slip ring, at least one ferrite bead, three connectors, and various hardware components. 
     Therefore, it would be desirable to provide a system and method of communicating electrical signals from a stationary base to a rotational portion of a moveable camera which overcomes the attendant disadvantages present in the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method and apparatus for minimizing component wear in a rotational camera and maintaining electrical connections between a rotating camera base and a fixed base. The invention comprises a slip ring assembly that advantageously couples the rotational portion of the camera to the stationary portion. One portion of the assembly remains fixed within the stationary base of the camera during rotation, while another portion freely rotates within the rotational section of the camera. By eliminating the rotation of one portion of the assembly, less wear occurs and wiring is less likely to become tangled within the camera. 
     According to one aspect of the invention, a slip ring assembly is provided for use in a rotating device platform. The camera includes a movable portion and a stationary portion. The assembly includes a housing, the housing having a body with a longitudinal axis, a top end region and a bottom end region, the top end region of the housing having a rotating portion rotationally coupled to the revolving portion of a rotating camera. The second end region is affixed to the stationary portion of the camera, wherein the rotational portion of the housing and the second end region of the housing rotate with respect each other. 
     According to another aspect of the invention, a rotating camera system is provided, which includes a stationary base, a rotating portion rotatably affixed to the stationary base, a motor for controlling the rotational movement of the camera, and a slip ring assembly. The slip ring assembly includes a housing, the housing having a body with a longitudinal axis, a top end region and a bottom end region, the top end region of the housing having a rotating portion rotationally coupled to the revolving portion of a rotating camera. The second end region is affixed to the stationary portion of the camera, wherein the rotational portion of the housing and the second end region of the housing rotate with respect each other. The rotating portion further includes electrical connectors thereon. The housing includes a stationary portion affixed to the stationary portion of the camera, the stationary portion having electrical connectors thereon, wherein the rotating portion and the stationary portion of the housing rotate with respect each other. The housing may further include a mounting flange for supporting the housing. The mounting flange includes an orifice to allow the top end and the bottom end of the housing to protrude therethrough. The top, rotating portion of the housing is rotatable with 
     In yet another aspect of the present invention, a method for minimizing frictional wear on components of a rotating camera system is provided. The method includes the steps of providing a housing having a longitudinal axis, the housing having a rotational component and a fixed component, coupling the rotational component to a rotating portion of a camera, and coupling the fixed component to the stationary portion of the camera, wherein the rotational component and the fixed component rotate with respect each other. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
     FIG. 1 is an exploded view of a rotatable camera incorporating the slip ring assembly of the present invention. 
     FIG. 2 is an exploded perspective view of the slip ring assembly of the present invention interfacing with opposing circuit boards. 
     FIG. 3 is a perspective view of the top end of the slip ring assembly of the present invention. 
     FIG. 4 is a perspective view of the bottom end of the slip ring assembly of the present invention. 
     FIG. 5 is a top view of the stationary base and rotating pan used in conjunction present invention. 
     FIG. 6 is an exploded view showing the relationship between the stationary base, the rotating pan and the slip ring assembly of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Initially, it is noted that the slip ring system described herein is particularly well suited for use in remotely controlled security cameras, as well as devices which are operable to pan in the horizontal direction and tilt in the vertical direction, or vice versa. The present invention advantageously increases reliability and reduces the number of steps for assembly and cost of materials of such devices. Further, the present invention provides an integral slip ring attachment mechanism as well as an improved horizontal rotation bearing support system. The advantages of the present invention will be more fully understood with reference to the Figures. 
     Referring now to the drawing Figures in which like reference designators refer to like elements, there is shown in FIG. 1 an exploded perspective view of a rotatable camera incorporating the slip ring assembly  10  of the present invention. It is to be understood that the rotatable camera illustrated in FIG. 1 is only an example of one type of rotatable camera. It is within the scope of the present invention to provide a novel slip ring assembly that can be incorporated into any rotatable camera employing separate rotatable and stationary portions. 
     Rotating camera assembly  5  is comprised of a motor housing  190  having a camera lens  195 . Motor housing  190  is pivotally mounted to support  200  via pivoting wheel  90 . Support  200  allows motor housing  190  to be tilted up and down in a substantially vertical direction as shown by directional arrow A in FIG. 1. A camera dome (not shown) is fitted over the components of the camera assembly. The dome includes a substantially vertical slot, which, after the dome is fitted over camera assembly  5 , allows lens  195  unobstructed access therethrough, thereby allowing lens  195  a full range of vertical rotation in order to capture images substantially in front of the camera. 
     Support  200  is also attached to revolving pan  125 . Revolving pan  125  rotates 360 degrees upon a stationary base  120  as shown by the directional arrows indicated as B. Revolving pan  125  rotates in a plane substantially perpendicular to the plane of rotation of motor housing  190 . As revolving pan rotates, motor housing  190  rotates in the same horizontal direction due to its connection with support  200 . The rotation of motor housing  190  allows lens  195  a full 360 degree range of horizontal rotational movement in order to capture images in any direction. Rotation of revolving pan  125  can be controlled either manually or by a motor upon receipt of a control signal. 
     The slip ring assembly  10  in accordance with the present invention can be seen in its preferred embodiment in FIG.  1  and in greater detail in FIG.  2 . Slip ring assembly  10  is inserted within the concentric receptacles in pan  125  and stationary base portion  120  and secured therein. Its purpose is to maintain electrical communication between components in revolving pan  125  and stationary base  120 . In addition, because the lower portion of assembly  10  does not rotate and is fixed within stationary base  120 , the wear on assembly  10  and the components thereon is minimized. 
     Referring now to FIG. 2, assembly  10  is shown in greater detail. Exemplary construction materials for assembly  10  include plastics, metals, alloys, or combinations thereof. In an exemplary embodiment, assembly  10  has a substantially cylindrical housing, a top end and a bottom end in which the housing is constructed from plastic. It will readily be understood that construction techniques available in the prior art can facilitate various alternate materials configurations of the components of the invention. 
     Assembly  10  includes a substantially cylindrical housing  20  having electrical connector pins  40  and  30  disposed at a respective top and bottom end thereof. Protruding from the top end of housing  20  is an internal cylinder  35  upon which connector pins  40  are mounted. Cylinder  35  and connector pins  40  are adapted to rotate with respect to housing  20  and connector pins  30 . Further provided proximate the bottom end of housing  20  is a mounting flange  50  having opposing engagement notches  60 . Housing  20  is configured such that its top end and bottom end rotate relative to one another to thereby allow rotational differentiation between connector pins  30  and  40  while maintaining electrical conductivity and to prevent electrical wiring connected to each end from becoming twisted during rotation of the camera. 
     Provided within the interior of housing  20  is an electrical lead arrangement which facilitates continuous electrical connection between connector pins  30  and connector pins  40  in a manner where individual connector pins correlate to the same individual connector pin even during rotation. The specific arrangement of components within the housing  20 , which allows the slip ring to operate, is not within the scope of this invention and is not discussed herein. The design of housing  20  allows connector pins  40  mounted on the top end of housing  20  to be inserted directly into an electrical receptacle such as a first printed circuit board (PCB)  80 . PCB  80  is coupled to revolving pan  125  and can also be arranged as an integral part thereof. PCB  80 , located within the revolving portion of a rotational camera includes among other things circuitry that allows for the rotational control of the rotational part of the camera. PCB  80  receives control signals from the stationary base portion of the camera and transmits these control signals to motor housing  190 . 
     The rotating portion of the camera, which includes revolving pan  125 , motor housing  190  and camera lens  195 , rotates freely, while the circuitry within the rotational portion of the camera (PCB  80 ) remains in electrical communication with stationary base  120  via assembly  10 . PCB  70  is a second printed circuit board located within the camera&#39;s stationary base  120 . Assembly  10  provides an electrical path between connector pins  40  (and PCB  80 ) and connector pins  30  (and PCB  70 ) via the electrical lead arrangement within housing  20 . 
     Connector pins  30  may be connected to circuitry within stationary base  120  or may be inserted within a connector receptacle on PCB  70  (as shown in FIG.  2 ). Additionally, connector pins  30  may be inserted into PCB  70  in the same fashion as connector pins  40  are inserted within PCB  80 . Alternately, connector pins  30  and  40  may be soldered to their respective PCBs. Regardless of the method used to affix the connector pins to their respective PCBs, internal cylinder  35 , because its rotation is independent of the housing  20  in which it resides, allows connector pins  40 , and therefore PCB  80  to which it is affixed, to freely rotate within rotational pan  125 . The second end of assembly  10  remains fixed within stationary base  120  and therefore does not rotate. Further, PCB  70  and any wiring connected thereto, does not rotate, therefore reducing component wear and the likelihood that wiring within the stationary base will become twisted, tangled and/or damaged. 
     FIG. 2 also shows mounting flange  50  with complementary opposing notches  60  along its outer edges securing housing  20  within the stationary base  120  of the camera. Mounting flange  50  facilitates the insertion of assembly  10  with the camera assembly. The interior of pan  125  includes a plurality of tabs that engage engagement notches  60  on mounting flange  50 . These tabs closely engage engagement notches  60  within stationary base  120  to further insure the integrity of a locked position when the components of the camera are assembled. 
     Referring now to FIG. 3, a top perspective view of assembly  10  is shown. Mounting flange  50  further includes concentric outer and inner rings,  55  and  65 , respectively. Rings  55  and  65  protect the protruding shaft of internal cylinder  35 . Connector pins  40  extend from the top of internal cylinder  35  and can be affixed to or protrude through or be soldered to PCB  80 , as shown in FIGS. 1 and 2. 
     Housing  20  includes internal cylinder  35  therein. The top portion of internal cylinder  35  extends from device  20  and includes connector pins  40  as shown in FIG.  3 . Internal cylinder  35  and the electrical connector pins  40  extending therefrom rotate along with PCB  70  within pan  125 . This allows for ease of rotation of camera lens  195  within the rotational portion of the camera while maintaining the electrical connection between electrical components in the stationary base  120 . 
     Also shown in FIG. 3 is mounting flange  50  disposed near the second end of housing  20 . Provided on mounting flange  50  are notches  60 , which are configured to facilitate mounting of the assembly  10  within the rotating camera. Connector pins  40  are shown with multiple pins protruding from internal cylinder  35  of the top end of housing  20  in a circular pattern. The pins are configured to either plug into a receptacle or to be soldered into the PCB. It will be readily understood that the configuration of the pins can be provided otherwise such as a straight line of pins, a square, a rectangle, etc. 
     FIG. 4 is a bottom perspective view of assembly  10  showing the non-rotational connector pins  30 . Connector pins  30  protrude from the bottom end of housing  20  for facilitating electrical connectivity with PCB  70 . The bottom end may be spring-loaded into stationary base  120  allowing connector pins  30  to protrude through the underside of base  120  for soldering with PCB  70  or connector pins  30  may be arranged to allow assembly  10  to be removably plugged into a mating connector on PCB  70 . In this manner, initial fabrication and subsequent repair is simplified by connectorizing the electrical connectivity between PCB  70  and assembly  10 . The arrangement of connector pins  30  is shown in a parallel double line arrangement although other configurations are possible. 
     Because connector pins  30  extend from device  20  and connector pins  30  extend from internal cylinder  35  which is internal to device  20 , the two sets of connector pins rotate with respect to each other, minimizing the twisting of wires and damage to internal components of the camera assembly  5 . Further provided on housing  20  is a mounting tab  110 . Mounting tab  110  is provided to facilitate interaction with a mounting receptacle when aligning assembly  10  in stationary base  120  of the camera. 
     FIG. 5 shows an exemplary top view of the base of a rotational camera comprised of stationary base  120 , and revolving pan  125 . Stationary base  120  has a receptacle  130  for receiving housing  20  of assembly  10  therein. Further provided are retaining clips  140 , which are configured to interact with notches  60  on mounting flange  50  when housing  20  is inserted into receptacle  130 . Retaining clips  140  are preferably integrated as part of stationary base  120 . 
     Revolving pan  125  is comprised of an substantially annular pan that swivels on stationary base  120 . Revolving pan  125  can be made to rotate upon stationary base  120  via a variety of ways. In the preferred embodiment, a plurality of ball bearings  135  are disposed between the interior race of stationary base  120  and the exterior race of revolving pan  125 , as shown in FIG.  5 . Each ball bearing  135  is held in place between a pair of raised protrusions  137  within the exterior race of revolving pan  125 . These raised protrusions act as compartments to maintain each ball bearing in proper alignment thereby allowing revolving pan  125  to freely rotate about stationary base  120 . The raised protrusions are only an exemplary embodiment of the invention. Alternately, the ball bearings may be fitted between the interior race of the stationary base  120  and the exterior race of the revolving pan  125  without the raised protrusions. The exemplary pan bearing attachment assembly shown in FIG. 5 provides an easier, faster, and lower cost assembly of a drive system, than was previously available. It is within the scope of the present invention to provide other rotting mechanisms commonly known in the art to allow revolving pan  125  to freely and smoothly rotate about stationary base  120 . 
     FIG. 6 is an exploded view of assembly  10 , revolving pan  125  and stationary base  120  depicting an intended assembly of the three components. Affixed to revolving pan  125  is a motor housing and a camera lens (as shown in FIG.  1 ). The rotation of rotating pan  125  can be controlled by a remote control, which sends control signals to the stationary base portion of the camera. The electrical connection of the stationary base  120  to the revolving portion of the camera, via assembly  10 , provides activation signals to the motor within motor housing  190 , which in turn, rotates the camera lens. The slip ring assembly  10  of the present invention is utilized in order to maintain the connection between the electrical components of the camera lens (via PCB  70 ) and the electrical components within stationary base  120  (via PCB  80 ) while eliminating rotation of components and wiring within the stationary base. 
     Stationary base  120  further includes a mounting spindle  150  having snap clips  160  provided around its periphery. Revolving pan  125  is configured with an aperture  170  for slipping over the spindle  150  to attach to stationary base  120 . 
     In practice, when revolving pan  125  is assembled to stationary base  120 , snap clips  160  engage the inner rim of revolving pan  125  to fixedly attach the two components. An internal diameter of spindle  150  is provided to correspond to the outside diameter of housing  20  of assembly  10 . Housing  20  is configured to slidably engage the internal diameter of the mounting spindle  150 . By this arrangement, the installation of assembly  10  within mounting spindle  150  increases the connection forces applied by snap clips  160  to the rim around aperture  170  of revolving pan  125 . 
     A close fit between the assembly  10  and the snap clips  160  ensure the integrity of locked position of the assembly. This advantageously provides a way to securely and economically fasten rotating pan  125  to base  120  while at the same time aligning assembly  10  with an axis of the rotating camera pan  125 . 
     Referring now to FIGS. 1 and 2, upon receipt of rotational control signals from stationary base  125 , the motor within motor housing  190  is activated, and rotational pan  125  begins to rotate, along with lens  195 . The motor can be any suitable drive motor, such as a stepper motor. The motor housing can be coupled to a series of pulleys and drive belts, which allows pan  125  and the components thereon to rotate freely and without encumbrance upon stationary base  120 . During rotation, the second end of assembly  10 , and all the components attached thereto, continues to remain fixed and non-rotational within stationary base  120 . Motor housing  190 , in addition to being able to rotate up and down in a vertical direction, rotates horizontally and in the same direction as pan  125  due to the attachment of motor housing  190  to pan  125  via support  200 . PCB  80 , which is internal to the rotating portion of the camera, rotates in the same direction as pan  125  due to its connection with connector pins  40  on the rotating top end of assembly  10 . The bottom end of assembly  10  is locked into place within stationary base  120 . Because the bottom end of assembly  10  and PCB  70  to which it is affixed, does not rotate within base  120 , damage to assembly  10  can be avoided since friction due to rotation is eliminated. Further, there is no possibility of wires within stationary base  120  becoming tangled due to rotation. 
     It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.