DE4410515A1 - Monitor for checking depth of fill of transparent container - Google Patents

Abstract

A monitor for checking the depth of fill of a transparent container (15) as used for drinks, milk products, oils etc has a source of infra-red light (17) whose housing (2) is closed by an IR filterglass (22) and which contains the IR transmitters (16,28) aligned with the receivers (19,29) in a unit (18) having a similar filterglass (24). Assuming a symmetrical cylindrical container the respective IR beams (16,33) will impinge on the receivers (19,29) in the event of contacts (12) underfill or the absence of a container (15). Correct fill causes refraction of the beam (33) via the container walls (34) and contents (12) to impinge on a receiver (30) or (30') depending on the refractive index of the contents (12).

Description

The present invention relates to a control device for fill levels of contents inside containers, with a transmitter for measuring radiation and at least an assigned first receiver, which, depending on the fill level of the Outputs different measurement signals.  

Such level control devices are such. B. everywhere wherever filling is required in automatic filling devices be filled into containers without direct human supervision should. This product is, for example Beverages, dairy products, vegetable and industrial oils ect.

It is already known from practice to use γ- Use radiation and with an appropriate detector evaluate the received signals. Especially before Environmental protection and rising health care background however, this level control device finds knowledge little acceptance. There are also disposal pro blemishes of the radioactively contaminated parts.

Furthermore, it is known from practice to use a measuring method To use high frequency base, where the effect is exploited becomes that liquids by capacitive coupling to a Shift the frequency of the respective RF radiation can. The disadvantage here, however, is that in particular in the aforementioned automatic filling devices the containers are filled with residues, which are just like the often high ambient humidity can lead to interference signals which Noticeably falsify the measurement.

Usual transmitted light processes, as they are e.g. B. from the Frischeikon trolls are known to fail due to diffraction, refraction and reflection effects, which light when passing through the Container is exposed. Process automatic filling systems namely usually very different containers and that ver a wide variety of contents, with several times a day between different Lichen containers and / or different contents becomes.  

Because of the irregular outer contours of most containers in the transition area between the body and the lid of the container, So in the area of the shoulder and neck, as well as because of the different optical properties of the different Containers and product types were product controls in transmitted light procedure has not yet been generally applicable.

The general aim is to fill the container with one any filling material on the observance of certain limits, so check for overfilling and / or underfilling. In doing so also features of the container itself such. B. detects the outer contour and possibly other characteristics of the product are measured and to be controlled. This process must be contactless and with done at high speed to complete the filling process automatic filling system not to be delayed.

Proceeding from this, it is an object of the present invention a control device of the type mentioned to further educate them in an interference-free and environmentally friendly operation for various container types and shapes as well as different filling material is suitable and with simple Structure in operation can be converted quickly.

According to the invention this object is achieved in that the Transmitting device at least a first measuring beam in one infrared wavelength range sends out and that the first Measuring beam and the assigned first receiver spatially so are aligned to each other that the measuring beam at least partially hits the receiver when there is no container in it the measuring beam is located, the container for the fill level con troll is moved through the measuring beam, which is absent unit in its path through the interior of the container also at least partially strikes the recipient.  

The object on which the invention is based is achieved in this way completely solved. By using light from one infrared wavelength range is the new control device particularly environmentally friendly, repercussions on the operation personnel, the product to be filled or the surrounding devices are almost impossible.

The inventor has recognized that this wavelength range can be used because almost all containers are transparent in the infrared are, with the further effect that the use of Glass containers increases again.

The new control device is also very fail-safe, because between the measurements there is a kind of self-control, where the presence and intensity of the measuring beam can be checked with the first recipient. The beam This is because it has to go back to the receiver between two containers meet by monitoring the required intensity possible contamination of filter discs etc. or an electrical malfunction can be determined.

Only if there is no product in the path of the measuring beam the inside of the container, the measuring beam hits again on the recipient, who thus the lack of the filling in Displays the area of the measuring beam. On the other hand, the The measuring beam does not hit the receiver if it is in its Path through the container is located. That way the new control device either to detect a Overfilling (measuring beam does not hit the receiver) or one Underfill (measuring beam hits the receiver) can be used.  

Surprisingly, this applies to everyone who is considered Container shapes, because the inventor found that for the The spherical shape for the sake of accuracy required here of the container walls at the entry and exit point of the measuring beam are each sufficiently viewed as a plane-parallel plate can, so that the offset of the measuring beam due to the refraction at the optical interfaces when it enters the container by the opposite offset at its exit com is pensated. This applies if the medium is outside the Container and the medium in the path of the measuring beam inside the Container has a very similar refractive index against vacuum having.

All that is required is that the container is in the area of the measuring beam is mirror-symmetrical to one transverse to the measuring beam level inside the container is what however e.g. B. of all rotationally symmetrical or flat containers is fulfilled. It can be further exploited that the Measuring beam, the wall of the container as it passes through the container crossed twice, its intensity is changed, so that an assessment of the properties of the container based on the measured intensity of the measuring beam is possible.

On the other hand, if there is filling material in the path of the measuring beam, then this broken so that it no longer hits the recipient. This is a digital yes / no decision for all containers ter possible, the change between different fill levels heights is achieved in that the height of the measuring beam z. B. must be adjusted based on a conveyor belt on which the be transported to the container to be checked. The The type of product itself does not matter, it must  only have a refractive index that of that of air is different. Also a cross offset of the containers on the Transmitting device to or from the transmitting device, that is in the course of the path of the measuring beam, poses no problems.

It should be noted here that possible losses due to reflection and absorption by a sufficiently high intensity of the measuring beam or corresponding sensitivity of the receiver compensated can be. The optical absorption properties of the Containers move into the background.

In summary, the control device is based on the principle that the measuring beam hits the receiver when no product is in his path exists and that he is no longer the recipient can hit if there is filling material. This method thus also allows the measurement of impermeability to the measuring beam gene filling goods, e.g. B. the measurement of solids such. B. porridge, Yogurt etc.

In a further development, it is preferred if the transmission is direction a second offset to the first measuring beam Emits measuring beam in an infrared wavelength range, wherein the second measuring beam is at least partially on a assigned second receiver hits when there is no container located in the second measuring beam.

The advantage here is that the new control device experience expanded measurement options instead of a pure yes / no Decision can now an overfill and underfill account trolls are carried out. The distance between the two Measuring beams is then the tolerance range, which is filled for "good"  Container is specified. In other words, with a good one filled container, the first measuring beam must pass the first receiver hit during the second measuring beam, which runs deeper than the first measuring beam, the second receiver must not hit.

It is preferred if at least one additional recipient provided that is spatially arranged to form a measuring beam, that this at least partially and temporarily on the other Receiver hits when there is product in the path of the measuring beam located inside the container.

The advantage here is that the type of filling is also checked can be. Depending on the refractive index of the container and that of the filling material is namely the measuring beam in a certain direction deflected by refraction, so that there by means of the further receiver of the respective measuring beam can be. The location of the recipient depends on the container and from the filling material, so that the correspondingly arranged further Receiver only takes the measuring beam safely if the correct container is filled with the right product. In order to a further check is possible, especially at automatic bottling lines is an advantage where frequent the containers and the contents are changed.

In addition, the intensity of the measuring beam with the second Receiver are measured, making further statements possible are. This is e.g. B. helpful wherever bottling Foam arises, such as B. with fruit juices or beer. This one too Foam acts like a filling and directs the measuring beam from it assigned recipient. Because of the scattering effects also hits this deflected measuring beam at least partially or temporarily to the other recipient. If the container is underfilled with filling material and a considerable excess of foam  there is no longer a wrong decision, because the further recipients decide z. B. based on the measured Intensity, whether it is actually the desired product or foam.

It is further preferred if at least for two measuring radiate another receiver is provided.

The advantage here is that the "foam effect" is completely hidden becomes. Even the filling of foam, which is actually not annoying was above a "correct" level now does not lead to an error message in the sense of overcrowding, because of the additional receiver assigned to the upper measuring beam recognizes that there is no filling material in the path of the upper measuring beam Foam is located.

With the help of two measuring beams, two assigned receivers and two other recipients can now make any kind of mistake bottling can be recognized because of the geometric arrangements the measuring beams and the receiver to the container and the filling material are customizable.

It is further preferred if at least one additional Receiver is provided, which is spatially a measuring beam is arranged that this is at least partially and temporarily strikes the additional recipient when he is through a Wall area of the container passes without being inside to enter.

In this advantageous way is also a control of Outer contour of the container possible. The course of the measuring beam because of the wall area of the container depends on the  geometric conditions, so that this is also recognized whether the correct container is in the measuring beam. The signal from the additional receiver can also be used as a trigger Signal are used, the evaluation of the signals of the assigned and additional recipients starts.

Overall, it is preferred if the transmitting device has a row-like arrangement of transmitters and / or if at least some of the receivers are arranged in rows.

The advantage here is that in addition or as an alternative to the mechanical adjustment of the transmission device and / or Receiver a kind of "electrical" adjustment is possible. Out The two line arrays become transmitter / receiver pairs depending on selected the geometric specifications. Are z. B. ten Transmitter arranged one above the other, by selecting two this transmitter not only the level but also the Tolerance range selected. Of course they have to assigned recipients can be selected accordingly. Depending on The type of filling and the container can also be the other Receiver can be switched on electronically. The same applies to the additional recipients.

It is preferred if a flat arrangement of Is intended for recipients.

The advantage here is that from the array of receivers the recipients can be selected for the filling process currently in progress is required. This Area array can either be an arrangement of discrete photo transistors etc., but it is also possible to use a surface to use sensor like a CCD array and only certain Read out pixels of this array and process them further.  

It is further preferred if a control and storage unit is provided in the for different types of containers and / or Fill types the spatial assignments between measuring beams and receivers can be stored.

On the one hand, it is advantageous that several "programs" in the Control and storage unit can be stored, so that at a change in the type of filling only to a new program must be switched, which then automatically the correct Selects transmitter and receiver. But here is another advantage that the correct transmitter and receiver are not from the user must be calculated beforehand, rather a kind of "teach-in" possible by first filling a correctly filled container between the sender and the receiver is brought, whereupon the tax and the storage unit then selectively actuates the individual transmitters and identified the recipient in that particular case serve as assigned, additional and additional recipients.

It is then preferred if the transmitting device and the Receivers are each housed in housings that have filters slices are closed that only light in the infrared Pass the wavelength range and for a hermetic Ensure closure to the environment.

The advantage here is that the new control device against spraying around spraying is protected, so that the Protection class IP 67 is maintained.

It is further preferred if the control and storage unit receives an input signal that indicates the position of the current controlling container represents.  

As a result, z. B. a synchronization reached at the speed of the conveyor belt so that on the additional recipient can be dispensed with, like mentioned above, also for synchronization and triggering are usable.

In summary, the new control device offers several Advantages, once it can be said to be an integrated property recognize the container, on the other hand it works independently of the contents, the shape of the container and other container properties, being insensitive to a transverse offset of the Container. Not only the outer contours of the containers can be measured without additional sensors, the control pre Direction monitors itself over the gaps between the individual Containers themselves, so that with only one transmitter and one or a few receivers different surveillance functions can be fulfilled. Since the measurement is on line takes place, each receiver in use must be in the in the simplest case just issue a yes / no decision, the new control device is also for high measuring speeds particularly well suited.

Further advantages result from the description and the attached drawing.

It is understood that the above and the following standing features to be explained not only in each specified combinations, but also in other combinations or can be used alone, without the scope of to leave the present invention.  

An embodiment of the invention is in the drawing shown and is described in more detail in the following description explained. Show it:

Figure 1 is a schematic side view of a Prinzipdar position of the new control device with a cut and partially broken container in vertical section.

FIG. 2 shows a horizontal section along the line 2-2 from FIG. 1;

Fig. 3 is a horizontal section taken along the line 3-3 of FIG. 1; and

Fig. 4 is a schematic representation of a receiver field, as it can be used ver in the control device of Fig. 1.

In FIG. 1, 10 denotes a control device which is provided for measuring fill levels of filling material 12 which is filled into the interior 14 of a container denoted by 15 . The container 15 is shown in Fig. 1 in vertical section and partially broken away.

The control device 10 comprises at least one first transmitter 16 for infrared radiation transmitting device 17 on one side of the container 15 and an arrangement 18 with at least one first receiver 19 on the other side of the container 15 .

The transmission device 17 is arranged in a housing 21 , which is hermetically sealed from the surroundings by a filter glass 22 . Likewise, the arrangement 18 is accommodated in a housing 23 which is hermetically sealed via a filter glass 24 . The filter glasses 22 , 24 are selected so that they are only permeable to the infrared wavelength range which is emitted by the transmitter device 17 . This prevents extraneous light from interfering with the measurement.

The transmitter 16 generates a first measuring beam 26 in the infrared wavelength range, which strikes the assigned receiver 19 in FIG. 1. It can be seen that there is no filling material in the path 14 of the first measuring beam 26 in the interior 14 of the container 15 , so that the first measuring beam 26 hits the assigned receiver 19 , which the first measuring beam 26 also, despite fourfold refraction at optical interfaces then hits when there is no container 15 in the path of the measuring beam 26 .

1 by a vertical distance 27 is below the first transmitter 16 in the illustration of FIG. 28, a second transmitter, which is assigned on the receiver side a second receiver 29. The second receiver 29 is also located below the first receiver 19 by the vertical distance 27 . Furthermore, a further receiver 30 is provided, which is arranged at a vertical distance 32 below the second receiver 29 . A second measuring beam 33 strikes this further receiver 30 and is emitted by the second transmitter 28 .

If there is no container 15 in the path of the second measuring beam 33 , it strikes the second receiver 29 . The same applies if there is no filling material 12 in the path of the second measuring beam 33 in the interior 14 of the container 15 , the beam path is then similar to that shown for the first measuring beam 26 in FIG. 1.

The beam profiles shown of the first and second measuring beams 26 , 33 can be explained with the help of the law of refraction. For this purpose it is assumed that the container 15 has a wall 34 which, for. B. consists of glass and is transparent to light in the infrared wavelength range. When a measuring beam 16 , 33 enters the wall 34 , the measuring beam is refracted to the solder towards the wall 34 at the point of impact, since the refractive index of the wall 34 is greater than the refractive index of calls (always measured against vacuum). When emerging from the wall 34 , the first measuring beam 26 is refracted again, so that there is only a parallel offset. A reverse offset occurs when the measuring beam 26 re- enters the wall 34 , so that the measuring beam 26 emerges from the container 15 at the same level at which it entered it. This applies to all containers in which the wall has approximately plane-parallel surfaces and in which the entrance and the exit wall are mirror-symmetrical to one another, but this is inevitably the case with all rotationally symmetrical and almost all flat containers 15 . In this way, the first measuring beam 26 is always meet regardless of the container shape to the associated receiver 19 when the container 15 is air in its path inside the fourteenth

If, on the other hand, the measuring beam 26 , 33 strikes filling material which has a larger refractive index than air, the measuring beam 26 , 33 is not broken back as much as is shown in FIG. 1 for the first measuring beam 26 . 1, the second measuring beam 33 runs accordingly in Fig. Down to the right away and applies depending on the optical properties of the filling material 12 z. B. on the further receiver 30 or the further receiver 30 '. The location of the further receiver 30 , 30 'thus depends on the one hand on the geometry of the container 15 and on the other hand on the optical properties of the filling material 12 .

For a correctly filled container 15 , as shown in FIG. 1, it is therefore expected that the first measuring beam 26 hits the first assigned receiver 19 . If this is not the case, the container 15 is overfilled. For the second measuring beam 33 it is expected that it will hit the further receiver 30 , 30 '. If, however, he encounters the second assigned receiver 29 , there is underfill. If, on the other hand, the second measuring beam neither hits the assigned receiver 29 nor the further receiver 30 , 30 ', there is a filling error, either the container 15 is incorrect or the filled product 12 .

From all this it follows that the recipients 19 , 29 , 30 , 30 'only issue yes / no decisions. However, it is also possible to measure additional intensities, so that statements can be made about the degree of absorption that the measuring beam 26 , 33 experienced on its way through the container 15 . In this way, statements about the quality of the container 15 can be obtained when the measurement signals of the receiver 19 , 29 are processed. Furthermore, further statements can be made about the filling material 12 if the intensities are measured with the further receivers 30 , 30 '.

The measurement results of the transmission device 17 are given via a multi-pole connection 35 in a control and storage unit 36 , which also receives an input signal 37 via which, for. B. synchronization with the transport speed of the container 15 is made possible, for example, from a conveyor belt. The control and storage unit 36 outputs an evaluation signal 38 which qualifies the filling level of the filling material 12 in the container 15 as underfilled, overfilled or correctly filled.

The control and storage unit 36 is also connected to the transmission device 17 via a further line 39 . Via the lines 35 , 39 , the control and storage unit 36 determines which transmitters 16 , 28 and which receivers 19 , 29 , 30 , 30 'are required for the respective filling process. This information can either be determined beforehand by the user and stored in the control and storage unit 36 , but it is also possible to first measure some correctly filled containers 15 in the manner of a teach-in method and then to add the results of this measurement use the correct transmitter 16 , 28 and receiver 19 , 29 , 30 , 30 'to select. Switching the control device 10 to new containers 15 and / or new contents 12 can thus be done very quickly, the control and storage unit 36 simply selects new transmitters 16 , 28 and receivers 19 , 29 , 30 , 30 'from a new program.

So far, only the vertical offset of the measuring beams 26 , 33 has been discussed with reference to FIG. 1, but such an offset also takes place in the horizontal plane, as will now be explained with reference to FIGS. 2 and 3.

Fig. 2 shows the first measuring beam 26 in the various conditions which it experiences depending on the position of the container 15 during the passage of this container 15 .

If the container 15 is not yet in the measuring beam 26 , it hits the assigned receiver 19 directly as an air jet 41 . This situation in the gaps between the individual containers 15 can be used to readjust the intensity of the measuring beam 26 and, if necessary, to determine errors. If the container 15 moves further, the measuring beam 26 finally strikes the container 15 and runs as an edge beam 42 through the wall 34 and strikes an additional receiver 43 , which is also designated in FIG. 1. The additional receiver 43 has a horizontal offset 44 to the associated receiver 19 , which offset 44 depends on the geometric conditions of the container 15 . In this way, an identification of the outer contour of the container 15 is also possible. A signal at the additional receiver 43 can thus be used to trigger the reading of the following receivers 19 , 29 , 30 , 30 '. Alternatively, the signal of the receiver 19 can also be used for triggering / contour detection.

If the measuring beam 26 has now penetrated into the interior 14 of the container 15 , it passes through the container 15 as an air jet 45 or as a central jet 46 and hits the associated receiver because of the compensating offset already explained in connection with FIG. 1 19 on.

This situation changes when there is filling material in the path of the measuring beam 26 , 33 , as is shown in FIG. 3 for the second measuring beam 33 . First, an air jet 47 is shown again in FIG. 3, when the measuring jet 33 strikes the assigned receiver 29 directly. If the measuring beam 33 now enters the interior 14 of the container 15 as a filling material beam 48 , there is a horizontal offset 49 and the measuring beam 33 strikes the further receiver 30 . This offset 49 is a measure of the optical and geometric properties of the container 15 and the contents 12 , as has already been explained Lich.

In FIG. 3 it can also be seen that a center beam 50 also reaches the assigned receiver 29 here, but only for a short time when passing through the center of the container 15 .

In this context, it should be noted that the measuring beams change when the containers push further through the respective measuring beams, so that the beam profiles shown in FIGS. 1, 2 and 3 always only predominate at times. In other words, the measuring beams 26 , 33 only partially and temporarily hit the named receivers. Because both the transmitting device has a certain transmission cone and the receivers have a certain reception cone, this partial and temporary impact does not lead to severe loss of intensity.

Based on Fig. 4 as a surface array 51 can be used by receivers will now be explained. FIG. 4 shows a field of receivers extending in the horizontal direction H and vertical direction V (see also FIGS. 1, 2 and 3), to which the assigned receivers 19 and 29 for the first and second measuring beam 26 and 33 count as well as the further receiver 30 , 30 'and the additional receiver 43 . It can be seen that these receivers are staggered not only vertically but also horizontally. Furthermore, a further receiver 52 is provided for the first measuring beam 26 , which strikes it when it encounters filling material on its way through the interior 14 of the container 15 . Since this filling material 12 should not be present, a signal from the further receiver 52 is an indication of overfilling or of excess foam, but this is recognized by the intensity of the measurement signal from the further receiver 52 .

Finally, an additional receiver 53 is provided for the second measuring beam 33 . The further measuring beam 33 strikes this additional receiver 53 when it passes through the wall 34 as an edge beam.

Generally 4 points of intersection are designed 54 of horizontal and vertical lines as a receiver, which are selected by the control and storage unit 36 depending on the filling process in Fig..

Referring to FIG. 4 will now once again be briefly explained how the entire measuring process for the case shown in Fig. 1 container 15 proceeds more. When the container 15 moves towards the control device 10 , the second measuring beam 33 arrives first in the region of the wall 34 , which leads to a measuring signal from the additional receiver 53 . The first measuring beam 26 then enters the wall 34 and causes a signal in the additional receiver 43 . The control and storage unit 36 can draw conclusions about the contour of the container 15 from the sequence of the signals from the receivers 19 , 29 and, if appropriate, the additional receivers 53 and 43 . When moving forward, the second measuring beam 33 now enters the interior 14 of the container 15 and is broken over the filling material 12 so that it strikes the further receiver 30 , 30 '. Finally, the first measuring beam 26 also reaches the interior 14 of the container 15 . Since the first measuring beam 26 is above the fill level, it hits the assigned receiver 19 again . If there is foam above the fill level, the first measuring beam 26 instead strikes the additional receiver 52 , which emits a low signal so that the control and storage unit 36 detects the presence of foam.

When the individual measuring beams 26 , 33 emerge from the container 15 , the process just described runs backwards, with receivers (not shown) possibly being used. If one of the conditions described does not occur, the control and storage unit 36 recognizes that it is an error which is correspondingly output on the line 38 .

In summary, the new control device 10 is based on a method in which a measuring beam in the infrared wavelength range is directed through the interior of a container, and then after the measuring beam has emerged from the container at one or two measuring locations to check where the measuring beam emerged is. The measurement location taken in each case enables a statement to be made as to whether or not the measurement beam has hit filling material 12 on its way through the interior 14 of the container 15 . If two such measuring beams are used, a qualification with regard to overfilling / underfilling is possible, the vertical distance between the two measuring beams representing the tolerance range for the inaccuracy of the filling level.

Claims (10)

1. Control device ( 10 ) for fill levels of contents ( 12 ) present in the interior ( 14 ) of containers ( 15 ), with a transmitter ( 17 ) for measuring radiation and at least one assigned first receiver ( 19 ), which, depending on the fill level of the fill material ( 12 ) outputs different measurement signals,
characterized in that the transmitting device ( 17 ) emits at least one first measuring beam ( 26 ) in an infrared wavelength range and that the first measuring beam ( 26 ) and the associated first receiver ( 19 ) are spatially aligned with one another in such a way that the measuring beam ( 26 ) at least partially hits the receiver ( 19 ) when there is no container ( 15 ) in the measuring beam ( 26 ), the container ( 15 ) being moved through the measuring beam ( 26 ) to check the fill level, which in the absence of filling material ( 12 ) its path through the interior ( 14 ) of the container ( 15 ) also at least partially strikes the associated receiver ( 19 ). 2. Control device ( 10 ) according to claim 1, characterized in that the transmitting device ( 17 ) emits a second measuring beam ( 33 ) offset to the first measuring beam ( 26 ) in the infrared wavelength range, the second measuring beam ( 33 ) at least partially an assigned second receiver ( 29 ) hits when there is no container ( 15 ) in the second measuring beam ( 33 ). 3. Control device ( 10 ) according to claim 1 or 2, characterized in that at least one further receiver ( 30 , 30 ', 52 ) is provided, which is arranged spatially to form a measuring beam ( 26 , 33 ) that this is at least partially and intermittently strikes the other receiver ( 30 , 30 ', 52 ) when the filling material ( 12 ) is in the path of the measuring beam ( 26 , 33 ) through the interior ( 14 ) of the container ( 15 ). 4. Control device ( 10 ) according to claim 3, characterized in that at least two measuring beams ( 26 , 33 ) each have a further receiver ( 30 , 30 ', 52 ) is provided. 5. Control device ( 10 ) according to one of claims 1 to 4, characterized in that at least one additional receiver ( 43 , 53 ) is provided, which is spatially arranged to a measuring beam ( 26 , 33 ) that this at least partially and temporarily strikes the additional receiver ( 43 , 53 ) when it passes through a wall region ( 34 ) of the container ( 15 ) without entering its interior ( 14 ). 6. Control device ( 10 ) according to one of claims 1 to 5, characterized in that the transmitting device ( 17 ) comprises a line-like arrangement of transmitters ( 16 , 28 ) and / or that at least some of the receivers ( 19 , 29 ; 43 , 53 ) are arranged in rows. 7. Control device ( 10 ) according to one of claims 1 to 6, characterized in that a flat arrangement ( 51 ) of receivers ( 54 ) is provided. 8. Control device ( 10 ) according to one of claims 1 to 7, characterized in that a control and storage unit ( 36 ) is provided, in which for different types of containers ( 15 ) and / or types of contents ( 12 ) the spatial assignments between measuring beams ( 26 , 33 ) and receivers ( 54 ) can be stored. 9. Control device ( 10 ) according to one of claims 1 to 8, characterized in that the transmitter device ( 17 ) and the receiver ( 19 , 29 , 43 , 53 , 52 , 30 , 30 ') each in housings ( 21 , 23 ) are housed, which are closed with filter disks ( 22 , 24 ) which only allow light in the infrared wavelength range and provide a hermetic seal to the environment. 10. Control device ( 10 ) according to claim 8, characterized in that the control and storage unit ( 36 ) receives an input signal ( 37 ) which represents the position of the container ( 15 ) currently to be checked.