NL2025764B1 - Poultry egg inspection method and system - Google Patents

Abstract

Poultry egg inspection method, in particular for determining an egg shell condition, including: -conveying a plurality of at least partly transparent egg receiving nests (N) along a conveying path (P), wherein a number of the nests (N) carry an egg (E); - illuminating transparent parts of the egg receiving nests (N) from below, at an egg inspection section (S) of the conveying path (P); and -optically inspecting each illuminated egg (E) from a location above the egg inspection section of the conveying path by a first sensing means (5; EY); wherein the method includes a determination step of using a second sensing means (10; 110) to determine at and/or upstream of the inspection area (S) if a nest (N) of the plurality of egg receiving nests (N) carries an egg (E), wherein the result of the determination step is used to control the illuminating of the transparent part of the egg receiving nest (N).

Description

P126930NL00 Title: Poultry egg inspection method and system The invention relates to a poultry egg inspection method, in particular for determining an egg shell condition. Systems for inspecting eggs, in particular poultry eggs, are known and are configured for various purposes. For example, US2009/0201323 discloses a system for candling living (fertilized) eggs. The known system is configured to inspect eggs in the cells of the egg crate grid moving on a conveyor. Row by row, the analyzing device synchronously monitors the light emission on the eggs of the row and detection of the attenuated light of emerging beams. The monitoring includes at least two close cycles of light emission. During the first cycle, which 1s of short duration to avoid causing glare of the detectors of the detecting device, the coordinates of possible empty cells in a row are determined and stored. During the second cycle, which is of longer duration, the coordinates of fertilized eggs of the row are determined and stored. The egg candling installation advantageously also marks the eggs, depending in particular on whether they are fertilized or not.

Besides, systems are known to inspect non-living eggs, in particular for determining an egg shell condition (such as the presence of egg shell cracks). For example, WO2012/060704 discloses a method and apparatus for examining eggs, in particular for determining eggshell characteristics of eggs, the method comprising the positioning of the eggs to be examined, and deforming a part of such an egg at least once, determining deformation contact time, and determining the shell stiffness and/or the eggshell strength of such an egg. Such a manner of detection can be suitably applied to sorting machines for eggs. With this methodology, in a short time, for a very large number of products, such as eggs in the present case, a quality parameter such as the strength and/or stiffness can be determined. With such determinations, in an advantageous manner, high requirements set in many fields of technology and industry can be met. As another example, EP738888 discloses a system having detector for determining cracks in eggshells, wherein a bouncing ball is used to provide information about whether or not an egg shell is intact.

The systems that use mechanical interaction with the eggshell provide good results but have various disadvantages, for example concerning hygiene and through-put. Presently, non-contact methods are investigated, using relatively high intensity light beams that are transmitted through the eggs. For example, WO2019039319 discloses an egg inspection device having a holding member for holding an egg, irradiation parts for irradiating the egg light, image capturing parts for capturing an image of the egg irradiated with the light, and a determination part for determining surface conditions of the egg. According to the document, an irradiation unit can be used that irradiates light that includes visible light to infrared light components.

The present invention aims to improve poultry egg inspection, in particular for determining an egg shell condition. An aim of the invention is to provide high throughput and reliable egg (shell) inspection. Also, an aspect of the invention concerns (a more ‘traditional’) improved egg shell inspection method using the human (naked) eye.

According to the present invention this is achieved by the features of claim 1.

Advantageously, there is provided a method system for inspecting poultry eggs, including: -conveying a plurality of at least partly transparent egg receiving nests along a conveying path, wherein a number of the nests carry an egg; - illuminating transparent parts of the egg receiving nests from below, at an egg inspection section of the conveying path; and -a first sensing means optically inspecting each illuminated egg from a location above the egg inspection section of the conveying path;

wherein the method includes a determination step of using a second sensing means to determine at and/or upstream of the inspection area if a nest of the plurality of egg receiving nests carries an egg, wherein the result of the determination step is used to control the illuminating of the transparent part of the egg receiving nest.

In this way, relatively large numbers of eggs can be conveyed and optically inspected (without mechanical interaction between a shell detector and the egg to be inspected), in an hygienic manner, wherein egg illumination can be controlled to improve detection results.

In particular, a control can be implemented to switch off and/or leave off illumination of a transparent part of an egg receiving nest (at the egg inspection section of the conveying path) in case it has been determined (by the determination means) that the nest is empty. On the other hand, in case presence of an egg in a nest has been determined, the control can lead to switching on illumination of the transparent part of the (egg carrying) egg receiving nest, for temporarily illuminating an egg that 1s present at the egg inspection section of the path. As a result, a human eye of an operator or detector (i.e. the first sensing means), that can be present to optically inspect passing eggs from above the egg inspection section of the conveying path, can safely look at the egg inspection sight without being blinded by source light.

Also, for example, dedicated, preferably spatially separated, first and second sensing means can be used for the determination step and the egg mspecting step, respectively, which can provide improved system reliability and throughput, allowing e.g. more time for processing of optical detection results of the (nest filling) determination step compared to prior art methods.

Further, an aspect of the invention provides a system, for example configured to carry out the method according to the invention. The system can be part of e.g. an egg sorting system, configured to convey eggs to different sorting location based on egg inspection results. Advantageously, the system includes: -a conveyor including at least one row of egg receiving nests, each of the nests being at least partly transparent; -at least one light source, located below an egg inspection section of a conveying path defined by the conveyor, the egg inspection section being associated with a first sensing means for optically inspecting passing eggs during operation; -at least one egg passage sensor configured to determine if a passing egg receiving nest carries an egg and to generate sensor information concerning the outcome of that determination; and -a controller configured to control operation of the at least one light source based on the sensor information of the egg passage sensor.

In this way, above-mentioned advantages can be achieved.

Further extra advantageous embodiments of the invention are provided in the dependent claims.

The invention will now be explained in more detail, with reference to the drawing. Therein shows: Figure 1 schematically part of a non-limiting example of an egg processing system, in a top view; and Figure 2 a cross-section over line II-II of Fig. 1, showing detector passage of a conveyor nest carrying an egg; Figure 3 is similar to Fig. 2, showing detector passage of an empty nest; and Figure 4 is similar to Fig. 2, showing detection by the naked eye.

Similar or corresponding features are denoted by similar or corresponding reference signs in this application.

Figures 1-2 depict a poultry egg inspection system, including a conveyor 1 (only part being shown), including at least one row of egg receiving nests N, each of the nests being at least partly transparent. The conveyor 1 is configured for conveying a plurality of eggs E along a conveying path (in a transport direction T), in particular as a number of rows of eggs E. Three parallel rows rl, r2, 13 are depicted in this example; 5 naturally, the conveyor 1 may be configured to convey the eggs in more or less than three rows.

Preferably, the conveyor 1 is an endless conveyor, e.g. an endless roller conveyer 1, wherein transparent nest sections are the nest areas (empty spaces) located between opposite egg supporting conveyor parts la (as follows from the drawings). The conveyor 1 can be configured for rotating the eggs during transport, e.g. respective longitudinal egg axes. In particular, the roller conveyor 1 can include egg supporting components 1a, for example parallel diabolo shaped (preferably rotating) rollers 1a, defining nests there-between for receiving (and rotating) the eggs E. The egg supporting elements (e.g. rollers) 1a can be mounted on respective shafts 1b that can be driven by suitable drive means (e.g. a motor, transmission belts or chains and the-like, not shown) for moving the shafts and rollers in the conveying direction T.

It follows that the conveyor 1 can include or define egg receiving nests N that are partly open (transparent, light-transmissive) at respective lower (egg supporting) sides, allowing light transmission along respective egg supporting elements (in this case along rollers) 1a.

Also, there are provided a number of light sources 2, located below respective egg inspection sections PS of the conveying path P that is defined by the conveyor 1. In this example, the light sources 2 can emit respective illumination beams B, for individually illuminating the eggs E passing respective egg inspection sections PS of the path P. Emitted Light can include various parts of the spectrum, e.g. visible light (visible to the human naked eye) and/or non-visible light such as infrared light.

In the present example, each light beam source 2 is arranged at a (vertical) level below a vertical level of the egg conveying path (see Fig. 2). The present light source 2 is arranged to emit the light beam upwardly, so all passing eggs E of a respective row rl, r2, 13 are subsequently illuminated by the beam B (the beam entering respective egg receiving nests N via respective open sides of those nests, in this example). The system can include various numbers of light sources 2, wherein each source 2 can be configured to emit one or more beams B e.g. for illuminating passing eggs of one or more conveyor rows rl, r2, r3. In a non-limiting example, the light source includes one or more light emitting diodes (LEDs) for emitting the beam B.

According to an embodiment, each light source 2 can be configured to emit or provide a collimated or focused beam B, in particular illuminating only part of an outer surface of each egg shell of a passing egg E.

Also, preferably, the system can be configured such (e.g. a conveyor transport speed and egg rotation speed is set such) that during operation, each egg E rotates about a respective longitudinal egg axis over when it 1s being illuminated by the light beam B.

In the present example, the system includes first sensing means 5 for detecting light emanating from the egg inspection sections of the conveying path P. In this case, the first egg sensing means are arranged above the conveying path P, in particular substantially opposite the light sources. The first sensing means 5 can include a number of detectors 5, e.g. camera’s, photocells or the-like.

Optionally (in case of non-human inspection), the system can include processing means 8 (drawn schematically) configured to process light detection results of the light detector 5, in particular for determining a condition of the shell of each of the eggs E during operation. Such processing means 8 can be configured in various ways, and can include e.g. processor software, processor hardware, a computer, data processing means, a memory for storing data to be processed, et cetera. Also, the processor means 8 can include or be connected to various respective communication means for allowing communication with the light detectors 5 for receiving detection results thereof, or the processing means 8 and detector(s) 5 can be integrated with each other. Besides, the processing means 8 can include e.g.

a user interface for allowing operator interaction with the central processor, and e.g. for outputting data processed by the processor.

Said optional processing means 8 are preferably configured to process light detection results for detecting any eggshell cracks of the eggs E. This processing as such can be carried out in various ways, as will be appreciated by the skilled person. For example, the processing means 8 can be configured to compare detection results with predetermined threshold data or calibration data, that may be stored in the processing means 8 or otherwise available to the processing means. For example, the processing means 8 can be configured to classify an examined egg as being ‘good’ (uncracked) in case it follows from the comparison that a respective detection signal is below a predetermine threshold, or in case a respective detection image substantially matches egg calibration image data of uncracked egg shells. Similarly, the processing means 8 can be configured to classify an examined egg as being ‘bad’ (cracked) in case it follows from the comparison that the respective detection signal is above a predetermine threshold, or in case a respective detection image substantially matches one or more calibration data images concerning cracked egg shells. Besides, the system can be configured to reject eggs that have been classified ‘bad’ (cracked) by the processing means, e.g. via egg removal means (not shown) for removing such eggs from the conveying path.

In a non-limiting example, respective image processing means can include a neural network, that can be based e.g. on machine learning from earlier calibration detection results (utilizing the detector 5 and beam source 2) on one hand and human (visual) inspection on the other, of a plurality of eggs including eggs of different color wherein part of the plurality of eggs contain eggshell cracks (or other physical shell irregularities).

Alternatively, sensing of light (emanating from the eggs E) can be carried out by the human naked eye EY (of a human inspector), as show in Figure 4. The resulting system can be made less complex compared to the system of Fig. 2, thereby providing advantages in view of overall costs and maintenance.

In the drawings (Fig. 2, 4), the light beam source 2 is depicted as emitting the beam towards a light detection location associated with the Light detector 5 or eye EY (see below), but that is not required (in particular in case the eggs internally diffuse received light).

Each light source 2 may be configured to operate continuously, but preferably emits the beam intermittently. Also, in an embodiment, operation of the beam source 2 can be synchronized with the conveyor 1 (e.g. with a conveyor speed) such that the source 2 only generates the beam B to illuminate a passing egg, wherein the source does not generate the beam otherwise. As will be discussed below, in a more preferred embodiment, a dedicated empty nest detector means 9, 10 is provided, to actually detect whether or not an egg E is present in a passing conveyor nest N, and to control the light source(s) 2 based on egg detection results.

In the embodiment of Figures 2, 3, the system includes a number of light detectors 5, arranged for detecting light emanating from the egg conveying path, in particular light transmitted through the eggs E during operation. In this example, three light detectors 5 are depicted, located at a vertical level above the egg conveyor 1. Thus, contamination of the detectors 5 (e.g. by dirt or other substances that may be present on passing eggs) can be prevented or significantly reduced. Each of these light detectors 5 can be associated with one of the transport rows rl, r2, 13 defined by the conveyor 1, and e.g. with one of said light beam sources 2. Alternatively, for example,

a single detector 5 can be installed for detecting light emanating from eggs of several of the rows rl, 12, r3. Besides, alternatively, one or more detectors can be located at another level, e.g. at or below a level of egg transport, and/or at different locations.

5 Each detector 5 can e.g. be configured to generate a detection signal, for example a digital image of the egg. In an embodiment, the respective detector signal or image can encompass the entire contour of the egg (see Fig. 3).

In case of human inspection (as in Figure. 4), the human inspector can e.g. mark a passing egg E in case of visible shell deviations (e.g. a crack), for example using ink or other egg marking means. Alternatively a human operator can use dedicated electronic egg marking means for marking such eggs, manually remove such eggs, and/or the like, as will be appreciated by the skilled person.

Furthermore, according to an aspect of the invention, the system includes a light source controller 9 configured to control operation of the at least one light source, as well as at least one dedicated egg passage sensor 10 (i.e. a second sensing means) located e.g. upstream (concerning the egg transport direction T) of a respective egg inspection section PS, the sensor 10 being configured to determine if a passing egg receiving nest N actually carries an egg E and to generate sensor information concerning the outcome of that determination. Preferably, the egg passage sensor 10 can be configured to generate an egg detected detection signal in case the sensor 10 senses a passing egg. The controller 9 controls operation of each of the light sources 2 based on the sensor information of the at least one -respective- egg passage sensor 10. An upstream location of the egg passage sensor 10 allows relatively much sensor signal processing time so that the light source(s) 2 can be timely controlled/switched, at relatively high transport speeds.

In the present example, one egg passage sensor 10 is associated with one of the conveyor rows rl, r2, 13, for determining which of passing nests N of that specific row contain an egg and which of passing nests N are empty.

In the present examples, the egg passage sensor 10 is located upstream with respect to a respective egg inspection section PS of the path P (concerning the same conveyor row rl, r2, r3). Alternatively or additionally, such a dedicated egg passage sensor 10 can be located at the respective egg inspection section PS, for example to sense presence of an egg E in the respective egg inspection section PS itself, and/or to sense an egg E approaching that egg inspection section wherein the egg E is located nearby (e.g. within 0-20 cm) of the egg inspection section PS.

Preferably, the controller 9 is configured to determine when a filled egg receiving nest N (i.e. the nest carrying an egg, as has been detected by a respective egg passage sensor 10) is located at an egg inspection section PS.

The light source controller 9 can activate the respective light source 2 only when such a filled egg receiving nest N is located at the egg inspection section PS.

To that aim, and in particular in case the egg passage sensor 10 is spaced-apart from the egg inspection section PS, the controller 9 can be provided e.g. with information concerning actual conveyor speed (e.g. speed information provided by a conveyor speed sensor and/or conveyor drive) and a predetermined distance between the egg passage sensor 10 and respective downstream egg inspection section PS, to determine when a nest N (having passed a sensor 10) reaches the egg inspection section PS.

For example, the controller 9 can include suitable software and/or hardware, e.g. a computer, a memory for storing conveyor speed related information and/or determined conveyor nest location information, for carrying out respective controller functions.

Such synchronization between egg detection by the sensor 10 and and the controlling of the light source(s) 2 can also be achieved differently by the controller 9, as will be appreciated by the skilled person.

Further, the controller 9 is preferably configured to temporarily activate a respective light source 2 to illuminate an egg E that is present in an egg inspection section PS, wherein the egg illumination is automatically switched off before the egg leaves that egg inspection section PS.

In this way, blinding of an opposite light sensor 5 and/or human eye EY can be prevented well.

In other words: preferably, each light source 2 is controlled such, by the controller 9, that the source 2 is only activated when emitted Light illuminates an egg E (to be transmitted through the egg E to an opposite sensor 5 or eye EY), wherein the source 2 is not active (does not emit light) at any other time.

Further, the source controller 9 can be a separate component or it can be integrated with and/or part of an aforementioned processing means 8 of the system.

The egg passage sensors 10 can be configured in various ways.

In a preferred embodiment, for example in case of relatively high processing speeds and throughput as well as reliability, each egg passage sensor 10 can be configured to detect a nearby (passing) egg in a non-optical manner, for example mechanically and/or via acoustic sensing(e.g. via ultrasound). Such a non-optical sensor 10 is not, or substantially not, susceptible to dust or optical contamination and any other circumstances that can influence optical sensor beam paths, such as deviating optical reflectivity and soiling of egg shell surfaces.

Each of the present egg passage sensors 10 is provided with mechanical sensing means 10a (for example a pivotal or flexible arm) that reaches into a respective egg conveying path, to be contacted by a passing egg (located in a respective conveyor nest N); during operation the sensor 10 can generate the egg detected detection signal in case the sensing means 10a 1s being mechanically contacted by a passing egg.

In the same way, the sensor can be an acoustic sensor emits an acoustic sensor signal towards the conveying path of the eggs, the acoustic sensor further including a sound detector to detect a resulting acoustic signal (emanating from the conveying path of the eggs) in order to determine passage of an egg.

In an alternative embodiment, e.g. in case of relatively low processing speeds, in particular in case the naked eye EY is used to inspect eggs (see Fig. 4), the egg passage sensor 110 can be an optical sensor (e.g. a camera or photodetector).

During operation the depicted system carries out a method for processing a plurality of eggs E, in particular unfertilized (e.g. poultry) eggs.

The unfertilized eggs are non-living eggs; the optically inspecting of the eggs is preferably carried out to detect eggshell cracks.

The eggs can be supplied, i.e. fed to the conveyor 1, in various ways, for example via a non-depicted upstream egg supplier.

The conveyor 1 conveys the eggs E along the respective transport paths, in particular by holding the eggs in respective partly transparent conveyor nests N, along the path P. As follows from the drawings, some of the nests N may be empty.

The transparent parts of the egg receiving nests N are illuminated from below (see Fig. 2, 4), at the egg inspection sections S of the conveying path P. Each illuminated egg E is being optically from a location above the egg inspection section of the conveying path, in particular by a detector 5 (as in Fig. 2) or by the naked eye EY (Fig. 4).

Preferably, during a start of operation, the light sources 2 are switched off (i.e. they do not emit light towards the egg inspection sections PS of the path P).

The method includes the determination step of determining at and/or upstream of the inspection area S if a nest N of the plurality of egg receiving nests N carries an egg E. The result of the determination step is used (by the source controller 9) to control the illuminating of the transparent parts of the egg receiving nests N.

In this case, a number of sensors 10 has been positioned along the egg conveying path P, at and/or upstream of the egg inspection areas PS. Each of those sensors 10, 110 will generate an egg detection signal in case of passage of an egg E (i.e. the egg E passing that particular sensor 10, 110). In particular, during operation, only the transparent parts of the egg receiving nests N that have been determined to carry an egg E, are illuminated (to illuminate that egg E), by a temporarily switching on of the respective Light source 2 (see Fig. 2). Preferably, the emitted illumination beam B can be collimated or focused beam, in particular illuminating a only part of an outer surface of each egg shell of a passing egg E.

The light source 2 is automatically switched off again before the egg E leaves the respective egg inspection section PS of the path P (leading to a situation such as in Fig. 3).

As is mentioned before, the determination step can include acoustically, for example ultrasonically, investigating passing egg receiving nests N. On the other hand, the determination step can includes mechanically, for example with a tactile sensor, investigating passing egg receiving nests N. Moreover, in case of inspection by the naked eye EY (see Fig. 4), the determination step can simply include optically, investigating passing egg receiving nests N (by an optical sensor 110).

It follows that all eggs E are illuminated by the system. In particular, this can involve illuminating each egg E (present in an egg inspection section of the path P) with a respective illumination beam B. At least part of the light that is received by the egg E, is transmitted through the egg E (i.e. at least part of the light entering the egg via the shell, to be diffused or scattered by contents of the egg E, to be at least partly emitted via the eggshell out of the egg again), and is detected by the detector 5 (for example by taking one or more digital images of the egg) or the eye EY. The system automatically prevents that illumination light is being emitted (by a light source 2) in case no egg E is present at a respective inspection site PS.

In this way, improved egg inspection can be achieved, at a relatively simple manner.

Next, after light detection, in the embodiment of Figures 2-3, the processing means 8 can process the light detection results (e.g. images) received from a light detector 5, for determining a condition of the shell of each of the eggs E. The light detection results can be processed for detecting eggshell cracks, wherein an egg having a detected crack is preferably removed from a conveying path. In the embodiment of Figure 4, human interaction can be used to mark or otherwise identify eggs having undesired shell conditions.

It is self-evident that the invention 1s not limited to the above- described exemplary embodiments. Various modifications are possible within the framework of the invention as set forth in the appended claims.

In this application, the eggs to be processed are in particular non- living, dead eggs, i.e. eggs for consumption that are not fertilized (and do not contain any embryo). The avian/bird eggs can be poultry eggs, for example chicken eggs.

Also, it will be clear that each light detector 5 can be located at various locations, and can be configured e.g. to detect light that has been transmitted from a single egg or light that has been transmitted from a plurality of eggs. For example, the system can include a plurality of detectors 5 for viewing an egg from different viewing directions. For example, at least one camera-type detector can be provided, each camera being arranged for taking images of one or more eggs, to be examined, at the same time.

Furthermore, each said light source 2 can be arranged at various positions, for example below, at and/or above a vertical level of the egg(s). Moreover, a plurality of light sources can be implemented for (e.g. simultaneously) illuminating a single egg E, from the same or from different directions.

Besides, the system can include a plurality of egg passage sensors 10, 110 of the same type (e.g. acoustic only, mechanical only, optical only), or a mix of types of egg passage sensors 10, 110. Also, the present method and system can be implemented for egg inspection method, in particular for determining an egg shell condition, but also for determining one or more other egg conditions, for example an egg content related condition, presence of blood and/or defects or other abnormalities within the egg.

The light source 2 can be controlled in various ways for illuminating transparent parts of the egg receiving nests N.

For example, the light source 2 can include one or more light emitters that can be controlled to be electrically powered during desired illumination periods (for illuminating transparent parts of the egg receiving nests N that carry eggs with the illumination beam B), wherein the power is turned off to turn off the one or more light emitters (so that no illumination beam B is generated) to avoid illuminating empty nests.

In another embodiment, the light source 2 can include or be associated with a controllable shutter, that can be moved into the path of the light beam B (upon control) to avoid illuminating empty nests N.

Claims (14)

Conclusions A poultry egg inspection method, in particular for determining an egg shell condition, comprising: conveying several at least partially transparent egg receiving nests (N) along a conveying path (P), wherein a plurality of the nests (N) carry an egg (E); - illuminating transparent parts of the egg-receiving nests (N) from below, at an egg inspecting section (S) of the transport path (P); and - optically inspecting each exposed egg (E) from a position above the egg inspecting section of the conveying path by a first detecting means (5; EY); the method comprising a determining step of using a second detecting means (10; 110) to determine at and/or upstream of the inspection area (S) whether a nest (N) of the plurality of egg-receiving nests (N) contains an egg ( E), wherein the result of the determination step is used to control the exposure of the transparent portion of the e1-receiving nest (N). A method according to claim 1, wherein only the transparent parts of the egg-receiving nests (N) determined to carry an egg (E) are illuminated. A method according to claim 1 or 2, wherein the inspecting of the eggs is performed by a human inspector (EY). A method according to any one of the preceding claims, wherein the determining step is performed by second detecting means (10; 110) which are spaced apart from the first detecting means (5; EY). A method according to any one of the preceding claims, comprising positioning a sensor (10; 110) or sensor part (10a) in an egg transport path, wherein the sensor (10; 110) generates an egg detection signal in case of passage of an egg (E). A method according to any one of the preceding claims, wherein the determining step comprises acoustically, e.g. ultrasonic, examining passing egg-receiving nests (N). A method according to any one of the preceding claims, wherein the determining step comprises mechanically, e.g. with a tactile sensor (10, 10a), examining passing egg-receiving nests (N). A method according to any one of the preceding claims, wherein the eggs are non-live eggs, wherein the optical inspection of the eggs is performed to detect egg shell fractures. A method according to any one of the preceding claims, wherein optically inspecting an exposed egg (E) from a position above the egg inspecting section of the transport path is performed by the naked eye (EY). A method according to any one of the preceding claims, wherein the second detection means are optical detection means (110), for instance a camera and/or photocell. A system for inspecting poultry eggs, in particular for determining an egg shell condition, for instance a system configured for performing a method according to any one of the preceding claims, comprising: - a conveyor (1) comprising at least one row e1-receiving nests (N), each of the nests being at least partially transparent; - at least one light source (2) located below an egg inspecting section of a conveying path defined by the conveyor (1), the egg inspecting section 1s associated with a first detecting means (5; EY) for in-use optical inspecting of passing eggs (E); at least one egg passage sensor (10; 110) was missing, e.g. positioned at and/or upstream of the egg inspecting section, wherein the egg passage sensor (10; 110) is configured to determine whether a passing egg receiving nest (N ) carries an egg (E) and to generate sensor information regarding the outcome of this determination; and - a controller (9) configured to control operation of the at least one light source (2) based on the sensor information of the egg passage sensor (10; 110). The system of claim 11, wherein the at least one egg passage sensor (110) is an optical sensor, e.g. a camera and/or photocell, arranged upstream of the egg inspecting section of the egg transport path. The system of claim 11 or 12, wherein the at least one egg passage sensor (10) is an acoustic sensor. A system according to any one of claims 11-13, wherein the at least one egg passage sensor (10) is a mechanical sensor, for example a mechanical contact sensor with a sensor element (10a) reaching the egg transport path (P).