CAMERA HEAD ASSEMBLY

Abstract

A camera head assembly for a camera, a camera including the camera head assembly and a method for mounting the camera head assembly. The camera head assembly includes a camera housing and at least one tray, wherein the housing includes at least one reference surface on its inner surface, and the at least one tray includes at least one reference surface corresponding to the reference surface of the housing, the least one reference surface of the at least one tray preferably being produced by cutting out, wherein the at least one tray is arranged inside the housing such that the at least one reference surface of the housing and the at least one reference surface of the at least one tray abut each other, and such that the tray is clamped between a first surface of the housing and a second surface of the housing.

Claims

1. A camera head assembly (100) for a camera comprising a camera housing (8) and at least one tray (5, 12), wherein the housing (8) comprises at least one reference surface (83, 85a, 85b, 85c, 810a, 16) on an inner surface of the housing, and the at least one tray (5, 12) comprises at least one reference surface (53, 55, 56a, 56b, 127) corresponding to the reference surface (83, 85a, 85b, 85c, 810a, 16) of the housing, wherein the at least one tray (5, 12) is arranged inside the housing (8) such that the at least one reference surface (83, 85a, 85b, 85c, 810a, 16) of the housing (8) and the at least one reference surface (53, 55, 56a, 56b, 127) of the at least one tray (5, 12) abut each other, and such that the tray is clamped between a first surface (85b, 89) of the housing (8) and a second surface (86, 88) of the housing (8).

2. The camera head assembly (100) according to claim 1, wherein the housing (8) comprises an extruded profile, and/or the at least one tray (5, 12) comprises a sheet metal part.

3. The camera head assembly (100) according to claim 1, wherein the at least one tray (5, 12) comprises a clamping arrangement (58, 59, 1211, 1212) for clamping the at least one tray between the first (85b, 89) and the second surface (86, 88) of the housing (8), and/or a fixation arrangement (4, 54, 15, 122) for fixing the at least one tray to the housing (8).

4. The camera head assembly (100) according to claim 3, wherein the clamping arrangement (58, 59, 1211, 1212) is arranged on a side of the at least one tray (5, 12) opposite a side at which the fixation arrangement (4, 54, 15, 122) is arranged.

5. The camera head assembly (100) according to claim 1, wherein the at least one tray (5, 12) comprises a bend (52) providing an opening (51) through which at least one electrical connector (61) of the camera is guided.

6. The camera head assembly (100) according to claim 1, wherein the at least one tray (5, 12) is configured to carry at least one printed circuit board assembly (6) and/or at least one optical block (12, 13, 14) of the camera.

7. The camera head assembly according to claim 1, wherein the housing (8) comprises at least one rib (85, 810) extending in a longitudinal direction of the housing (8) on the inner surface of the housing, and the reference surface (85a, 85b, 85c, 810a) of the housing is disposed on the rib (85, 810).

8. The camera head assembly according to claim 1, wherein the housing (8) comprises a positioning key (16) for pre-fixing the tray (5, 12) in a predetermined position, wherein the reference surface (83, 85a, 85b, 85c, 810a, 16) of the housing is disposed on the positioning key (16).

9. The camera head assembly (100) according to claim 1, further comprising a back cover (3) attached to the housing (8) at a first predetermined position, and a front cover (9) attached to the housing (8) at a second predetermined position, wherein a position of the reference surface (83, 85a, 85b, 85c, 810a, 16) is related to the first predetermined position and/or related to the second predetermined position.

10. The camera head assembly (100) according to claim 9, wherein the back cover (3) comprises an opening (30) for accommodating the electrical connector (61), and a lid (1) attached to the outer side of the back cover for covering the opening (30) in the back cover (3), the lid (1) comprising at least one connection socket providing access to an electrical connector (61).

11. A camera comprising the camera head assembly (100) according to claim 1, a swivel mechanism (200) mechanically connected to the camera head assembly (100) for orientating the camera head assembly (100), and a base (300) mechanically connected to the swivel mechanism (200) for attaching the camera at a support structure.

12. A method for installing the camera head assembly (100) according to claim 1 comprising the steps: arranging the at least one tray (5, 12) inside the housing (8) by abutting the at least one reference surface (83, 85a, 85b, 85c, 810a, 16) of the housing to the corresponding at least one reference surface (53, 55, 56a, 56b, 127) of the at least one tray (5, 12), and clamping the at least one tray between the first (85b, 89) and the second (86, 88) surface of the housing (8).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further advantages and embodiments of the invention can be seen in the following description and the accompanying figures. The invention is illustrated schematically by means of examples in the figures and is described below with reference to the figures.

[0027] FIG. 1 shows an example of a surveillance camera according to a preferred embodiment of the present invention in a perspective side view;

[0028] FIG. 2 shows an example of the various parts of the camera head assembly according to a preferred embodiment of the invention in an exploded drawing;

[0029] FIG. 3a shows an example of a tray for carrying PCBAs according to a preferred embodiment of the invention in a perspective side view, and FIG. 3b shows the tray of FIG. 3a equipped with a PCBA and a heating connecting element in a different perspective side view;

[0030] FIG. 4 shows an example of a housing according to a preferred embodiment of the invention in a perspective back view;

[0031] FIG. 5a shows an example of a tray for carrying an optical block according to a preferred embodiment of the present invention in a perspective side view, and FIG. 5b shows the tray of FIG. 5a equipped with an optical block in a different perspective side view;

[0032] FIG. 6 shows the housing of FIG. 4 in a perspective front view; and

[0033] FIG. 7 shows the housing of FIGS. 4 and 6 in a back view, with the PCBA tray as shown in FIG. 3b and the optics tray as shown in FIG. 5b installed in the housing.

DETAILED DESCRIPTION

[0034] FIG. 1 depicts a preferred embodiment of a camera according to the present invention. The camera comprises a camera head assembly 100 according to a preferred embodiment of the invention, a swivel mechanism 200 that is mechanically connected to the camera head assembly 100 and allows for orientating it in a desired position. A base 300 for attaching the camera to a support structure is connected to the swivel mechanism.

[0035] FIG. 2 shows an example of the various parts of the camera head assembly 100 according to a preferred embodiment of the invention in an exploded drawing. The depicted camera head assembly 100 includes a housing 8 in which a tray 5 carrying PCBAs 6 (PCBA tray 5) and a tray 12 carrying an optical block 13, 14 (optics tray 12) is disposed. The PCBA tray 5 additionally comprises a heat transferring element 7, which is arranged between the PCBAs 6 and a heat dissipating surface 81 of the housing 8. The depicted optical block includes a lens bracket 13 and a lens 14 mounted at the lens bracket 13.

[0036] Both trays 5, 12 are fixed to a back side of the housing with a screw 4, 15, wherein the optics tray 12 is positioned and pre-fixated inside the housing 8 with a positioning key 16 fixed to a front side of the housing 8 by a screw 11. Details of the positioning and fixing of the trays 5, 12 are given below in connection with the following FIGS. 3a to 7. A back cover 3 is attached by four screws 2 to the back side of the housing 8. The back cover 3 has an opening 30 for accommodating electrical connectors 61 of the PCBA 6, which is covered with a lid 1 screwed to the back cover 3. On the opposite side, a front cover 9 is attached to the housing with four screws 10 that contains a viewing window for the lens 14.

[0037] The invention is described below in a coherent and comprehensive manner with reference to the figures.

[0038] A preferred embodiment of the invention as described in the following in reference to the figures relates to mounting a tray 5 carrying PCBAs 6 with heat dissipation needs as shown in FIG. 3b, or an optical block 13, 14 as shown in FIG. 5a, inside an extruded profile serving as a housing 8, as shown in FIGS. 4, 6 and 7.

[0039] The camera head assembly 100 according to the invention takes advantage of the small manufacturing tolerances of cut-outs in sheet metal parts used as trays 5, 12 forming the reference surfaces of the tray, and machined reference surfaces 83, 85a, 85b, 85c, 810a in the housing 8 of the camera head assembly 100. The reference surfaces 83, 85a, 85b, 85c, 810a are arranged in the housing 8 in such a way that the trays 5, 12 or the heat transferring elements 7 attached to the trays 5, 12 are firmly connected to the surfaces 81, 89 which allow heat dissipation (cf. FIGS. 4, 6 and 7). In other words, the trays are arranged inside the housing 8 such that they are in contact with the heat dissipating surfaces 81, 89 of the housing 8.

[0040] The reference surfaces 83, 85a, 85b, 85c, 810a in the housing 8 are positioned relative to fastening holes 20a-20d, 101a-101d (hole pattern) of the back and front cover 3, 8 and relative to the back or front sides of the housing 8. The reference surfaces 83, 85a, 85b, 85c, 810a are further positioned in close proximity to the back or front sides of the housing 8, to avoid an influence of the straightness and twisting tolerances along the extruded profile forming the housing 8.

[0041] The PCBA tray 5 and the optics tray 12 are each equipped with a bend 52, 121 at the back to fixate the trays 5, 12 to the housing 8, as well as with pre-cut-out surfaces to interface with surfaces on the back and front side of the housing 8 (cf. FIGS. 3a, b and 5a, b). Typically, the PCBA tray 5 needs to have tight positional tolerance to the back cover 3 and to the heat dissipating surface 81, and the optics tray 12 needs to have tight positional tolerance to the front cover 9, where the light goes through a viewing window 90. Since both trays 5, 12 are to be assembled from the back side of the housing 8, the approach to precisely locate the trays 5, 12 to the back (PCBA tray 5) or front side (optics tray 12) follows a different approach.

[0042] In the case of the PCBA tray 5, the tray 5 equipped with a PCBA 6 and a heat transferring element 7 is first manually positioned in vertical direction (Y-direction) with its top surface 56a onto the reference surface 85a. Subsequently, the tab 54 of the bend 52 is inserted into the corresponding recess 83 on the back of the housing 8 and fastened with a screw 4 through a hole in the tab 54 in a thread 82 (cf. FIGS. 3a and 4). When positioning the PCBA tray 5, it is also important to ensure that the top surface 56b of the tray 5 facing the front of the housing 8 is in contact with the reference surface 85b (cf. FIGS. 3a and 4).

[0043] The position in longitudinally direction of the housing 8 (Z-direction) is achieved using the flexibility of the PCBA tray 5 in that direction, due to the bend 52 and a nominal gap between the bend 52 and the thread 82 in Z-direction before the screw 4 is tightened. By tightening the screw 4 a contact between the reference surface 85c and a corresponding edge of the tray 55 (as reference surface) is achieved defining the position of the PCBA 6 and the head connecting element 7 (cf. FIGS. 3a, 3b and 4). The side surfaces 53 of the bend 52 of the PCBA tray 5 (cf. FIG. 3a) are cut before the bend 52 is made and are accurate enough to provide a positional reference in cross direction (X-direction) by interfacing with the recess 83 on the back side of the housing 8.

[0044] The PCBA tray 5 is then clamped in Y-direction at the opposite side of the housing (front side) by untightening two nuts 59, pre-assembled onto stud-weld-screws 58 against a clamp surface 86 ensuring the upper surface 56b of the tray 5 is interfacing with the reference surface 85b (cf. FIGS. 3a, 4 and 7). Instead of a stud-weld-screw the screw could be a normal countersunk head screw with counter-nut plus the untightening nuts.

[0045] The PCBA 6 can be fixated to the tray 5 via three screws 65a-65c screwed into three holes 57a-57c of the tray 5 (FIG. 3b) and be accurately positioned to the housing 8 so that the electrical connectors 61 can pass through the opening 51 provided by the bend 52 and align with the opening 30 on the back cover 3 (cf. FIG. 3a).

[0046] The back cover 3 is fastened to the housing 8 by means of the screws 2, which are screwed into the fastening holes 20a to 20d. The fastening holes 20a-20d are positioned relative to the heat dissipating surface 81 and to the reference surfaces 85a, 83 for positioning the PCBA tray 5. The fact that the PCBA tray 5 is evenly connected to the housing (via the screw 4 at the back and via the clamping means 58, 59 at the front), ensures that the thermal connection element 7 has a correct compression ratio with respect to the heat dissipating surface 81 and ensures sufficient heat flow to the housing 8. In other words, the PCBA tray 5 is arranged inside the housing 8 such that it is in contact with a first surface 85b and clamped against a second surface 86, to ensure adequate heat dissipation from the PCBA 6 arranged on the tray 5.

[0047] In the case of positioning the optics tray 12 inside the housing 8, it is important to define its position relative to the front side of the housing 8, in order to maximize the field of the lens view angle.

[0048] After positioning the optics tray 12 on the heat dissipating surface 89 from the back side of the housing 8 (cf. FIG. 4), the correct position of the tray 12 with regard to the front side can be achieved by using a positioning key 16 (as reference surface), which relates the position of a cut-out slot 127 (as reference surface) on the front side of the optics tray 12 to a slot 810 located on the front side of the housing 8 in X- and Z-direction (cf. FIGS. 5a, 5b and 6). Furthermore, the positional key 16 relates the position in Z-direction of the tray 12 to the front of the housing 8 by tightening a screw 15. Tightening the screw 15 ensures that the positional key 16 is in contact with the slot 810 of the housing and the slot of the tray 127 in Z-direction. Thus, a pre-fixation of the optics tray 12 in the housing 8 is achieved.

[0049] To attach the tray 12 to the back side of the housing 8, the bend 121 of the optical tray 12 is screwed with the screw 15 through the hole 122 into the thread 87 (cf. FIGS. 4 and 5a). There is a small nominal gap between the bend 121 of the optical tray 12 and the thread 87, so that tightening the screw 11 while taking advantage of the flexibility of the tray in the Z-direction due to the bend 121 and the slots 123 further increases the contact of the position key 16 with the slots 810, 127 in the Z-direction.

[0050] The optics tray 12 is then clamped in Y-direction at the opposite side of the housing (front side) by untightening two nuts 1212, pre-assembled onto stud-weld-screws 1211 against a clamp surface 88, to achieve robust positioning and suitable heat dissipating contact between the surface 89 of the housing 8 and the optics tray 12 (cf. FIGS. 5a, 5b, 6 and 7). Thus, the optics tray 12 is clamped between the surface 89 as a first surface and the clamp surface 88 as a second surface.

[0051] Before the optics tray 12 is positioned inside the housing 8 in the way described above, the lens 14 is mounted on the lens bracket 13 which is then positioned and pre-fixated on the optics tray 12 by two lugs 132 inserted into cut-out holes 124 provided on the surface of the tray 12. For final attachment of the lens holder 13 to the optics tray 12, four screws 125 are screwed into the through holes 126 and fixate the lens bracket 13 from below.

[0052] The front side of the housing 8 further provides additional threads 812a, 812 b for fixating eventual accessories such as IR-PCBA and polarizing filters. The rib used to construct the heat dissipating surface 81 allows the thread 812a to be positioned thereon thus minimizing thread carrying profiles needed on the housing 8.

[0053] Alternatively or additionally, a single tray could simultaneously carry both a PCBA and an optical block. In this situation a choice on the side of the housing (back or front) is needed and the reference of the tray in Z-direction would be made to one of the sides not to overdetermine the mounting of the tray. In this situation the solution of referencing to the back side may be used and in addition a positional key may be placed at the front, wherein the positional key at the front may not reference the Z direction to avoid overdetermination.

[0054] It may also be possible to install the trays from opposite sides so that the solution explained above for the PCBA tray is used on both sides and no positioning key is required.

[0055] Summarizing, the proposed invention allows to fixate trays that can carry printed circuit board assemblies (PCBAs) with heat-loads that need to be dissipated and/or optical blocks inside an extruded profile serving as housing such that the heat load is dissipated efficiently while ensuring sufficient positioning robustness and accuracy of the trays to a front or backcover attached to the housing.