Abstract:
An adjustable housing for a surveillance TV camera which can be mounted by a mount to a wall, a pole or a ceiling inside or outside the building includes a front panel, an adjustable camera support for adjustably mounting the TV camera inside the housing, an adjustable pane assembly with front and rear holders and a transparent window having a transparent pane enclosed between the two holders and a rear support for supporting and locking the pane assembly to the front panel. The front holder has a front window frame which is smaller than the opening in the front panel through which the TV camera is aimed at different zones.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a housing for a television camera apparatus used for surveillance applications. 
     DESCRIPTION OF THE PRIOR ART 
     Surveillance television cameras are commonly mounted onto a wall, pole, ceiling or any other fixed bases by using an extended arm, known as a camera mount. The extended arm or camera mount includes a swivel joint, which permits the positioning of the horizontal and vertical axes of the camera in order to direct the camera lens toward its intended observation end. In many cases television cameras are covered by a housing and as a result, the entire camera assembly becomes large and heavy, which requires very heavy mounting accessories for vandal proof environment. Furthermore, it is not possible to employ television cameras that are mounted on a mount and a swivel joint because common mounts with swivel joints can be easily tampered with and/or break and/or can be used for self hanging inside jails, particularly for detention cells that are violent in nature. Therefore, cameras used for observation of detention cells are commonly mounted inside vandal proof camera housings which are made of a thick steel. Such camera housings are fixedly bolted to walls or ceilings, which limits the positioning of the horizontal and vertical axes of the cameras to within the housing interiors, with the camera positioning particularly restricted by the size of the visible area of the front pane. 
     Observing the interiors of small cells from within the cell interior require the use of very wide angle lenses, known as fisheye lenses. Cameras employing very wide angle lens require very wide front panes in order not to obstruct the vision to the lens. However, a wider pane can be easier tampered with and break and therefore, for a vandal proof housing it is necessary to minimize the size of the front pane. This in turn further restricts the adjustment of camera positioning within the housing, particularly when the camera is fitted with very wide angle lens. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a housing for a television camera that is vandal proof and which permits a wider repositioning of its horizontal and vertical axes for observing different scenes. This and other objects of the present invention are attained by a camera housing with an adjustable front pane comprising: a mount for attaching said housing to a structure selected from the group consisting of a wall, a pole and a ceiling; a front panel; an adjustable camera support for mounting a TV camera inside said housing and adjusting said camera within an interior of said housing by aiming said camera at different zones through an opening in said front panel; an adjustable pane assembly including a front holder, a rear holder and a transparent window having a transparent pane enclosed between said rear holder and said front holder which are attached together, wherein said rear holder includes a rear window frame and said front holder includes a front window frame which is smaller than said opening and wherein said transparent pane along with said rear window frame and said front window frame form said transparent window; a rear for supporting and locking said pane assembly to said front panel wherein said front panel includes fastening means for tightening said pane assembly between said rear support and said front panel and wherein said pane assembly further includes one of passages or cutouts for said fastening means such that said transparent window can be positioned at different zones of said opening commensurating with said aiming of said camera. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects and features of the present invention will become apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings, in which: 
     FIGS. 1A,  1 B and  1 C are perspective views of television camera housing systems of the invention, mounted to a wall and a ceiling; 
     FIGS. 2A,  2 B, and  2 C, are perspective views of the camera mounting inside the housings shown in FIGS. 1A,  1 B and  1 C, respectively; 
     FIGS. 3A and 3B are exploded perspective views of the front pane and the front pane attachment, respectively of the camera case of the present invention; 
     FIG. 4A is partial sectional view of the camera and the pane window for the housing of the preferred embodiment of the present invention; 
     FIG. 4B is a diagram of the aspect ratio of a television system and the lens circular field of view; and 
     FIG. 5 is a front view of the front pane assembly showing the movements thereof. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Shown in FIGS. 1A and 1C are two vandal-proof TV camera housings or cases that are bolted to a wall. FIG. 1A shows a housing system  100  that is mounted perpendicularly to the wall and FIG.  1 C shows a housing system  200  that is bolted in parallel to the wall. FIG. 1B shows a vandal-proof housing system  300  that is bolted to a ceiling. A front pane  2 R is adjusted to an upper-right corner of an opening  23  in a front panel  1  of the housing system  100 . The smaller pane  2 C is adjusted to a center portion of the opening  23  of the front panel  1  of the housing system  200  and the largest pane  2 L is adjusted to a lower-left corner of the opening  23  of the front panel  1  of the housing system  300 . The size of the front window  22  of a front pane assembly  20  shown in FIGS. 3A and 3B is commensurate with the angle of view α of a lens  6  and the distance x between a lens focal point  7  and the windows  21  and  22  of the pane assembly  20  shown in FIG.  4 A. 
     All television systems such as NTSC standard of the European PAL standard employ a frame size having the aspect ratio 4:3 wherein the horizontal length H is 4 and the vertical height V is 3 as shown in FIG.  4 B. Since the lenses provide a circular field of view L, having a radius R, the size of the circular field of view of the lens must be measured by the diagonal value D of the frame F which is equal to the diameter of circular field of view L. The diagonal value is calculated by the well known formula D={square root over (H 2 +V 2 )} or D={square root over (4 2 +3 2 =5)}. Accordingly, the size ratios for the horizontal length H of 4, the vertical height V of 3 and the diagonal length D of  5  are the well known values of the standard television aspect ratio, and these values are used for calculating the size of the rear and front windows  21  and  22  of the pane assembly  20  and the opening  23  of the front panels  1  of the housing systems  100 ,  200  or  300 . 
     Therefore, depending on the lens angle of view a and the distance X between the lens focal point  7  and the front window  22  it will be simple to calculate the size of the windows  21  and  22 . For example, the lens shown in FIG. 4A has an angle of view α of 90° and it is mounted with its focal point  7  at a distance X of 50 mm. Accordingly, the length of the radius R of the lens circular field of view is 50 mm(tan45°=1, or R/X=1), the diagonal value D is therefore 100 mm, the horizontal length H is 80 mm (⅘×100) and the vertical height is 60 mm (⅗×100). If a difference aspect ratio is used, such as 16:9 aspect ratio of the high definition television, the window size will have to be calculated in accordance with the aspect ratio of the television system employed for television camera  11 . 
     A parallel wall mount  60  of the camera housing system  200  of FIG. 1C is shown in detail in FIG. 2C without a housing cover  61  and the front panel  1 . The camera  11  with the lens  6  are mounted on a vertical camera support  14  that provides vertical positioning for camera  11  around the V axis of the two vertical locking screws  18  (only one is shown), the vertical locking screws  18  also attach the vertical camera support  14  to a horizontal camera support  12 . The horizontal camera support  12  is mounted onto a camera holder  63  using a horizontal locking screw  16  which provides for adjusting and locking the camera  11  with its supports  12  and  14  around its H axis; thereby, the camera can be adjusted to independent horizontal and vertical positions within the camera housing system  200 . 
     As shown in FIG. 2C the similar camera positioning setup is provided in the camera housing system  300  of FIG. 1B, with the exception of a camera holder  53  which is attached in parallel to a ceiling mount  50 , instead of the camera holder  63  which perpendicularly attached to the parallel wall mount  60  of the camera housing system  200 . 
     As shown in FIG. 2A, the camera positioning setup of camera housing system  100  of FIG. 1A is also fundamentally same, with the exception of the camera holder  43  which is attached perpendicular to the vertical wall mount  40  and which attaches the horizontal camera support  12  from its bottom side, instead of the horizontal camera support which is attached to camera holders  53  and  63  of the camera housing systems  200  and  300  from their top side. 
     It is obvious from the explanation above that the camera  11  along with its lens  6  can be positioned around the H axis and V axis within the camera housing interiors and within the clearance of opening  23  of the front panel  1  for observing different scenes. 
     Instead of using the vertical and horizontal camera supports and/or the camera holders, camera  11  can be mounted onto a well known swivel joint for positioning adjustment, or onto a well known tripod head, or onto any other well known camera positioning devices. 
     Vandal-proof housings employ a thick front transparent pane to ensure that the pane cannot be easily broken. The thickness of the front pane depends on the size of the front pane window; for a larger front pane window a thicker pane is needed. On the other hand, a thicker pane reduces the optical transparency and clarify of the pane and degrades the overall optical performance of the camera mounted inside such vandal-proof housing. 
     Shown in FIG. 3A is the pane assembly  20  including a front pane holder  3 , a transparent pane  2  and a rear pane holder  4 . The front pane holder  3  has a front window  22  and the rear pane holder  4  has a rear window  21 , both windows having a size commensurating with the lens used and the distance between the focal point  7  and the front window  22  as shown in FIG. 4A, or is slightly larger, to allow for some tolerances during the positioning of the camera. However, minimizing the window sizes improve upon the strength of the pane and provides for the use of a thinner pane. The pane  2  is mounted between the front and the rear holders  3  and  4  and fastened by four screws  3 A shown in FIG.  3 A. The front pane holder  3  provides four tapered holes  3 B for the flat head screws  3 A and the rear holder comprises thread holes  3 D, complementing the thread of screws  3 A. Instead of using the screws  3 A it is possible to attach the front and rear pane holders by welding or by riveting or by other fastening means, so long as the rear and front holders are fixedly attached together and enclose the transparent pane  2 . 
     Shown in FIG. 3B is the pane assembly  20  supported between the front panel  1  and a rear support plate  5 . Four locking screws  1 A tighten the rear support plate  5  and lock the pane assembly into position. 
     The locking screws  1 A may be special flat head screws or that type head screws requiring a special non-standard screw driver shape, thereby preventing the use of knifes and other available means to tamper with the locking screws. The front panel  1  is provided with tapered holes  1 B or other shaped holes to accommodate the screw head shapes and the rear support plate  5  is provided with threaded holes  1 D, complimentary to the locking screws  1 A thread. 
     A key lock with  1 K a key  3 K can be used instead of the screws  1 A and the panel  1  can be provided with a matching hole  1 M to accommodate the lock, while the rear support plate  5  can be provided with a groove  1 G complementary to a tongue  1 T of the key lock  1 K; reference numeral  2 K denotes a key lock assembly. Alternatively, the screws  1 W can be fixedly attached or welded to the front panel and the holes  1 P of the rear support plate can be non threaded holes and the rear support plate  5  can be tightened to the front panel by using complimentary nuts  5 N to the welded screws  1 W. 
     The single support plate  5  shown in FIG. 3B can be constructed of several parts instead of the single plate such as the rear support  5 S and  5 T shown in FIG. 3B; similarly, the locking screw cutouts  1 C or the movement cutouts  5 A can be differently arranged as long as the visible pane  2 W of the pane assembly  20  can be moved around within the opening  23  of the front panel  1  without being obstructed by the locking screws  1 A or the locks  1 K or the nuts  1 N or the any other suitable fasteners used instead of the locking screws  1 A and that the single support plate  5  or that the several supports  5 S and  5 T used to replace the single support plate are such that the rear support tightens and locks the pane assembly  20  to the front panel  1 . 
     The locking screw cutouts  1 C provide a passage for the locking screws  1 A and at the same time the cutouts size is such that the pane assembly  20  can be repositioned and locked with its visible pane  2 W into different zones within the front panel opening  23 . Similarly, the four tongues  3 C of the rear panel holder  4  having the threaded hole  3 D and the movement cutouts  5 A of the rear support plate  5  are sized to enable the tongues  3 C to move freely inside the cutouts  5 A so that the visible pane  2 W is freely shifted and locked into different zones within the front panel opening  23  as shown in FIG.  5 . The vertical shifting VX and the horizontal shifting HX are sized so as not to reveal the screw  3 A of the pane assembly  20 . The visible pane  2 W shown in FIG. 5 is a pane calculated for a wide angle lens, but the sizes of the visible pane  2 W can be modified into any sizes, so is the opening in the front panel, similarly the size of the tongues  3 C, the cutouts  1 C and  5 A can be differently sized or shaped to allow for different movements, and tolerances. 
     The pane  2  is constructed of hardened glass or plastic material and the holders  3 , the support  5 , the front panel  1 , the housings  41 ,  51 , and  61  and the mounts  40 ,  50  and  60  are made of steel, but can be made of any other metals or plastic materials. 
     The housing systems  100 ,  200  and  300  shown in FIGS. 1A,  1 B and  1 C, respectively can be modified by changing their basic orientation downward, sideways or upwards, as well as their width, length or height. In fact, it becomes obvious that unlimited shapes and sized can be designed for camera housings that can incorporate the means to modify and adjust a front pane, so as to provide for accurate positioning of camera inside the housing, without obstructing the field of view of the lens as disclosed here. It will of course, be understood by those skilled in the art that the particular embodiment of the invention here presented is by way of illustration only, and is meant to be in no way restrictive, therefore, numerous changes and modifications may be made, and the full used of equivalents resorted to, without departing from the spirit of scope of the invention as outlined in the appended claims.