Industrial camera and method for testing its degree of insulation from external agents

Abstract

An industrial camera (1) comprises a camera body (10) suitable for the connection of an optical system and delimiting an inner chamber (16) in which image sensors (18) and an electronic circuitry (20) are housed. The camera body is made so as to prevent the ingress of dusts and liquids from entering into the inner chamber. In the inner chamber a pressure sensor (25) is installed, connected to the electronic circuitry (20) to detect the pressure value inside the inner chamber (16).

Description

DESCRIPTION"INDUSTRIAL CAMERA AND METHOD FOR TESTING ITS DEGREE OF INSULATION FROM EXTERNAL AGENTS"

[0001] The subj ect of the present invention is an industrial camera and a method for testing its degree of insulation from external agents , in particular dusts and liquids .

[0002] Industrial cameras used for example to carry out quality controls of parts are known .

[0003] For certain applications , it is necessary to use industrial cameras that are impermeable to the ingress of dusts and liquids , for example having a protection degree of IP67 or IP68 .

[0004] It may however occur that , either due to an assembly of the industrial camera that is not entirely correct , or due to manufacturing errors of the components , or due to the aging of the components , the sealing degree of the camera does not correspond to what is declared or worsens over time .

[0005] The purpose of the present invention is to provide an industrial camera that makes it possible to check, both during the production step and periodically during the use of the camera, whether the protection degree from external agents ( in particular dusts and liquids ) corresponds to what is declared by the manufacturer .

[0006] Said purpose is achieved with an industrial camera according to claim 1 , a test method according to claim 5 and a test system according to claim 7 .

[0007] The features and advantages of the industrial camera and of the test method according to the invention will however be evident from the following description of its preferred embodiments , given by way of example and not limitation, with reference to the accompanying figures , in which :

[0008] - Figures 1 and la are two perspective views of an example of industrial camera according to the invention;

[0009] - Figure 2 is a plan view of an electronic board suitable for being housed inside an industrial camera according to the invention, wherein a pressure sensor and the related control circuitry are highlighted;

[0010] - Figure 3 is an exploded perspective view of an example of assembly of the industrial camera of figures 1 and la according to the invention with related accessories ; and

[0011] - Figure 4 is a schematic representation of a test setup for checking the degree of impermeability of the industrial camera according to the invention .

[0012] In said drawings , the industrial camera has been denoted as a whole by number 1 (hereinafter also more briefly " camera" ) .

[0013] The camera 1 has a camera body 10 , for example of prismatic shape .

[0014] The camera body 10 is suitable for the connection o f an optical group - not shown . For example , the camera body 10 is provided with a bushing with external threading 12 for the screwing of an optical element .

[0015] The camera body 10 is provided with at least a first electrical connector 14 connectable , through a respective first cable 14 ' ( figure 3 ) , to an external control unit 100 ( Figure 4 ) , for example a computer .

[0016] The camera body 10 delimits an inner chamber 16 in which image sensors 18 and an electronic circuitry 20 connected to the first electrical connector 14 are housed .

[0017] As shown in figure 2 , in an embodiment the electronic circuitry 20 is made with a printed circuit electronic board, for example formed of three board portions 20a, 20b, 20c connected to one another by a flexible flat cable 20d, so as to mount the three board portions in the inner chamber 16 one above the other , so as to make a very compact camera 1 .

[0018] In an embodiment , the camera body 10 is provided with at least a second connector 22 connected to the electronic circuitry 20 and suitable for being connected to a respective second cable 22 ' , which may for example be a cable for power supply and / or serial interface and / or a control cable , for example for control ling a deformable optical element and / or input / output of electrical signals .

[0019] The camera body 10 is made so as to prevent the ingress of dusts and liquids into the inner chamber . For example , the camera body 10 gives the camera 1 a protection degree of IP67 or IP68 .

[0020] In the inner chamber 16 a pressure sensor 25 connected to the electronic circuitry 20 is installed to detect the pressure value inside the inner chamber 16 .

[0021] In an embodiment illustrated in figure 2 , the electronic circuitry 20 comprises , for example mounted directly on a portion of the printed circuit electronic board 20a, electronic control devices of the pressure sensor 25 .

[0022] In an embodiment , the electronic control devices of the pressure sensor 25 are further configured to communicate the detected pressure value to the external control unit 100 .

[0023] In an embodiment illustrated in figure 2 , the pressure sensor 25 is also mounted directly on a portion 20a of the printed circuit electronic board 20 .

[0024] The pressure value read by the pressure sensor 25 i s made available to the user of the camera using the communication standard of the camera .

[0025] The reading of the pressure value can be used during the production of the camera to check the correct assembly and the IP sealing . Indeed, as will be described in greater detail in the continuation of the description, the reading of an overpressure inside the camera compared to the atmospheric pressure implies an incorrect as sembly of the device or manufacturing errors of the components such as to compromise its declared IP 67 / 68 seal ing .

[0026] Thanks to the pressure sensor installed inside the camera 1 , the pressure value can also be read by the user during the commissioning and operational step of the product to check its correct assembly and periodically check the state o f the device and its sealing degree with respect to the aging of the components .

[0027] It should be noted that , in order to check whether the industrial camera possesses , and / or maintains over time , the expected degree of insulation from external agents , in particular dusts and liquids , the pressure sensor is installed inside the body of the camera,understood as the machine body, also referred to as the "housing, " which houses and supports inside it the functional components of the camera, in particular the image sensor 18 , and which is provided with electrical connectors 14 , 22 for interfacing with the outs ide .

[0028] Figure 3 shows an example of complete assembly of the camera 1 with IP67 / 68 accessories which serve to house the optical group and to seal the system with respect to the external environment .

[0029] In particular, a protective tube 30 with window suitable for protecting an optical element - not shown - can be mounted on the camera 1 . This protective tube 30 is connected to the front side of the camera 1 by means of an adapter fitting 32 which in turn is fixed to said front side of the camera 1 by means of the external threading of the bushing 12 and is prevented from unscrewing by a fixing counter-ring 34 . Optionally, a protective tube extension 36 can be provided between the adapter fitting 32 and the protective tube 30 .

[0030] The subj ect of the present invention is also a method for testing the impermeability degree of the camera body 10 of the industrial camera 1 described above .

[0031] The proposed test method makes it possible to recreate an IP67 / 68 sealing test ( according to the IEC60529 standard) in air instead of water, by inserting the camera inside a test chamber with pressuri zed air . The air pressure inside the test chamber is chosen so that it corresponds to that exerted by the water column at the speci fic depth of the required IP degree .

[0032] The method therefore provides for placing the camera to be tested inside a test chamber and hermetically closing said test chamber .

[0033] The interior of the test chamber is then brought to the predetermined test pressure , higher than the atmospheric pres sure . In particular, in an embodiment , the test pressure corresponds to that exerted by the water column at the speci fic depth of the required IP degree .

[0034] After a predetermined waiting time , for example 30 minutes , the pressure inside the camera body is detected by means of the pressure sensor 25 inside the industrial camera .

[0035] The pressure value detected by the pressure sensor 25 is compared with the atmospheric pressure value , preferably detected at the time of assembly of the test setup, at the beginning of the test and before pressuri zing the test chamber itsel f .

[0036] Any variation in the internal pressure compared to the atmospheric pressure is indicative of air ingressinto the camera body and therefore of a defect in the assembly and / or in the manufacturing of the components , for example of the sealing elements .

[0037] In an embodiment , a test pressure sensor is also placed inside the test chamber, optionally with its electronic control circuitry, for example based on a microcontroller, to detect the test pressure value inside the test chamber . Said test pressure sensor is preferably the same as that used inside the camera ( in order to have the same range of possible errors , thus making any comparison between the data detected by the two sensors more reliable , i f necessary) .

[0038] Therefore , a comparison can also be made between the pressure value detected by the pressure sensor inside the camera and the pressure value detected by the test pressure sensor, for example both during the detection of the initial atmospheric pressure and during the pressure test .

[0039] The subj ect of the present invention is also a test system ( or setup ) for implementing the above-described test procedure .

[0040] With reference to figure 4 , the test system therefore compri ses a test chamber 40 suitable for containing at least one industrial camera 1 and providedwith sealing means to be hermetically insulated from the external environment .

[0041] The test system further comprises test pressure detection means 41 , which include a test pressure sensor 42 inserted in the test chamber . As anticipated above , in a preferred embodiment , the test pressure sensor 42 is equal to the pressure sensor 25 inside the industrial camera 1 .

[0042] The test system further compri ses compressed air generation and regulation means 50 suitable for bringing the test chamber 40 to a predetermined test pressure .

[0043] The test system further comprises a processing unit 100 connected to the industrial camera 1 and to the test pressure detection means 41 and configured to perform a comparison between the pressure value inside the camera body detected by the pressure sensor inside the industrial camera and the test pressure value detected by the test pressure detection means .

[0044] With reference to the schematic representation of figure 4 , a practical example of implementation of the test procedure will now be described .

[0045] Some cameras 1 to be tested are inserted inside the test chamber 40 .

[0046] The test chamber 40 is hermetically closed .

[0047] The test chamber is connected to a compressed air source 502 .

[0048] The internal pressure of the test chamber is adj usted to the desired value by means of a special regulation valve 504 . I f the pressure should prove too high, a special safety valve 52 would open, preventing damage to the cameras or to internal components .

[0049] It is checked that the discharge ball valve 54 is closed .

[0050] The ball valve 506 in line with the compressed air source 502 is switched to the open position .

[0051] It is checked, by means of the test pressure sensor 42 ( connected to a board with microcontroller 44 and equal to the pressure sensors 25 inside the cameras ) , that the internal pressure of the test chamber actually corresponds to that set by means of the regulation valve 504 .

[0052] It is waited for the time provided by the parameters of the desired I P degree , for example 30 minutes for an IP67 grade test .

[0053] The pressure values recorded by the pressure sensors 25 inside the respective cameras 1 are observed, and it is checked whether the pressure inside the cameras 1 has increased compared to the atmospheric pressure . I f so , itmust be concluded that air has entered the cameras and therefore that there are unwanted air passages .

[0054] The ball valve 506 in line with the compressed air source 502 is switched to the closed position .

[0055] The discharge ball valve 54 is switched to the open position, so as to open the test chamber safely .

[0056] The test chamber 40 is opened and the cameras 1 are removed .

[0057] To the embodiments of the industrial camera, of the method and of the test system according to the invention, a person skilled in the art may make modi fications , adaptations and replacements of elements with others functionally equivalent , in order to meet contingent needs , without departing from the scope of the following claims . Each of the features described as belonging to a possible embodiment may be implemented independently of the other described embodiments .

Claims

CLAIMS1. An industrial camera (1) , comprising a camera body (10) suitable for the connection of an optical system and provided with at least a first electrical connector (14) connectable to an external control unit (100) , wherein the camera body delimits an inner chamber (16) in which image sensors (18) and an electronic circuitry (20) connected to said first electrical connector (14) are housed, wherein the camera body is made so as to prevent dusts and liquids from entering into the inner chamber, the industrial camera being characterized in that a pressure sensor (25) connected to the electronic circuitry (20) is installed in the inner chamber to detect the value of the pressure inside the inner chamber (16) .

2. Industrial camera according to claim 1, wherein the electronic circuitry (20) comprises electronic control devices of the pressure sensor (25) .

3. Industrial camera according to claim 2, wherein said electronic control devices of the pressure sensor (25) are further configured to communicate the detected pressure value to the external control unit (100) .

4. Industrial camera according to any one of the preceding claims, wherein the camera body is provided with at least a second connector (22) connected to theelectronic circuitry (20) and suitable for being connected to a power supply and / or serial interface cable (22' ) and / or to a control cable, for example for controlling a deformable optical element and / or electrical signal inputs / outputs .

5. Industrial camera according to any one of the preceding claims, comprising a protective tube (30) provided with a window, suitable for protecting an optical element, the protective tube (30) being connected to a front side of the camera body (10) by means of an adapter fitting (32) , which is fixed to such a front side of the camera body (10) by means of a threaded bushing (12) of the camera body (10) , the adapter fitting (32) being further engaged by a fixing counter-ring (34) which prevents it from being unscrewed from the threaded bushing ( 12 ) .

6. Industrial camera according to any one of the preceding claims, wherein the camera body (10) is provided with a bushing with external threading (12) for the screwing of an optical element.

7. A method for testing the degree of impermeability of an industrial camera according to any one of the preceding claims, comprising the steps of: a) positioning the camera inside a test chamber; b) hermetically closing the test chamber;c ) bringing the interior of the test chamber to a preset test pressure value , higher than atmospheric pressure and for a time set by the standard depending on the degree of protection required; d) detecting, by means of the pressure sensor inside the industrial camera, the pressure inside the camera body; e ) comparing the pressure value detected by the pressure sensor inside the camera with the atmospheric pressure .8 . Method according to claim 7 , wherein step e ) comprises the sub-steps of : el ) detecting the value of the test pressure inside the test chamber by means of a test pressure sensor equal to the pressure sensor inside the industrial camera ; e2 ) comparing the pressure value detected by the pressure sensor inside the camera with the pressure value detected by the test pressure sensor .9 . Method according to claim 7 or 8 , wherein, i f the pressure value detected by the pressure sensor inside the camera di f fers from the atmospheric pressure , the ingress of air into the camera body is reported .10 . A system for testing the degree of impermeability of an industrial camera according to any one of the preceding claims 1- 6 , comprising :- a test chamber (40) suitable for containing at least one industrial camera (1) according to any one of claims 1-5 and provided with sealing means to be hermetically insulated from the external environment; - test pressure detection means (41) , comprising a test pressure sensor (42) inserted into said test chamber, the test pressure sensor (42) being equal to the pressure sensor (25) inside the industrial camera; compressed air generation and adjustment means (50) suitable for bringing the test chamber to a preset test pressure ;- a processing unit (100) connected to the industrial camera and to the test pressure detection means and configured to make a comparison between the value of the pressure inside the camera body detected by the pressure sensor inside the industrial camera and the value of the atmospheric pressure, preferably detected before bringing the test chamber to overpressure.

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