Imaging system and camera module

Abstract

This invention relates to an imaging system having at least one camera module and an evaluation module, and to a camera module. The camera module includes a time-of-flight 3D image sensor for generating 3D image data and a 2D camera for generating 2D image data. The camera module and the evaluation module are connected to each other via a single connecting cable. The power supply to the camera module is achieved through the connecting cable, and the camera module is designed to transmit both 3D and 2D image data to the evaluation module via the connecting cable. The evaluation module is designed to process the 3D and 2D image data.

Description

Technical Field

[0001] The present invention relates to an imaging system having at least one camera module and an evaluation module, wherein the camera module includes a time-of-flight based 3D image sensor for generating 3D image data and a 2D camera for generating 2D image data. Background Technology

[0002] In different industrial applications, imaging systems that combine different methods for imaging are required. For example, an area to be monitored can be monitored using a conventional camera that creates a 2D image, as well as a depth sensor. Depth information can be generated by a depth sensor (such as the aforementioned 3D image sensor), which allows for more precise monitoring of industrial processes, for example.

[0003] The camera module of such imaging systems can also be called a sensor head, which should be designed to be as small and compact as possible to ensure its applicability in as many scenarios as possible. Furthermore, it is required that the connection between the sensor head / camera module and the evaluation module be as simple as possible so that the camera module can be used, for example, at the end effector of a robotic arm (so-called "end-of-arm" applications). Summary of the Invention

[0004] Therefore, the object of the present invention can be considered as providing an imaging system having a compact camera module that is easy to connect to an evaluation module.

[0005] This objective is achieved by the imaging system according to the invention.

[0006] The imaging system according to the invention includes at least one camera module and an evaluation module. The camera module includes a time-of-flight 3D image sensor for generating 3D image data and a 2D camera for generating 2D image data. The camera module and the evaluation module are interconnected via a single connecting cable. The power supply to the camera module is achieved through (specifically, solely through) the connecting cable, and the camera module is designed to transmit both 3D and 2D image data to the evaluation module via (specifically, solely through) the connecting cable. Finally, the evaluation module is designed to process the 3D and 2D image data.

[0007] According to the present invention, only a single connecting cable is required to achieve the electrical connection between the camera module and the evaluation module (i.e., for data connection and power supply), which significantly simplifies the connection between the camera module and the evaluation module. In particular, in the aforementioned "end-of-arm" applications or in hard-to-access areas, the connection of the camera module can be significantly simplified.

[0008] According to the present invention, power supply to the camera module and transmission of image data can be achieved via a single connecting cable. To enable this combination of transmission via cable, the camera module must be designed to be energy-efficient, and image data processing must be offloaded to the evaluation module. By offloading this functionality to the evaluation module, not only is energy saved, but the camera module can also be designed to be smaller and more compact, which is highly advantageous for the aforementioned industrial applications.

[0009] The aforementioned 3D image data is understood to be image data generated by a 3D image sensor, specifically, image data containing depth information, such as the distance from the object represented in the image data to the 3D image sensor. 2D image data can be "conventional" image data, which represents a two-dimensional image from a conventional photograph. 2D image data may, for example, include color or grayscale information for multiple image pixels.

[0010] The camera module and the evaluation module are connected to each other via only one connecting cable. This means that the power supply to the camera module from the evaluation module is preferably achieved through only one connecting cable. Similarly, it is preferred that only one connecting cable is used to transmit 2D and 3D image data from the camera module to the evaluation module. It is possible that the camera module and the evaluation module are mounted to a common structure, such as an autonomous vehicle. However, the camera module and the evaluation module are mounted separately, and preferably at different locations on the common structure, and as described above, communication and power supply are achieved solely through the connecting cable. Alternatively or additionally, the evaluation module may also be fixed in position, while the camera module may be movable, for example, when the camera module is attached to a robotic arm.

[0011] The processing of 3D and 2D image data in the evaluation module can be understood in particular as fusing the 3D and 2D image data to store 2D image data that also contains depth information. This processing can also be understood as, for example, performing object detection or object tracking within the 3D and / or 2D image data.

[0012] Advantageous extensions of the invention are specified in the specification and drawings.

[0013] According to the first embodiment, the evaluation module is designed to transmit operational information to the camera module via a connecting cable. The operational information preferably includes configuration for the camera module and / or triggers for initiating image acquisition. Preferably, a return channel exists between the evaluation module and multiple camera modules or a single camera module, through which the evaluation module can transmit data to the camera module.

[0014] The configuration transmitted from the evaluation module to the camera module can be, for example, the following settings: what image size the 3D image sensor and / or 2D camera should provide, what color depth the 2D camera should be set to, and / or what scan frequency and / or depth range the 3D image sensor should use.

[0015] The aforementioned trigger activates at least one camera (i.e., a 3D image sensor or a 2D camera) to acquire image data and transmit the recorded image data to the evaluation module. This trigger allows the evaluation module to control when the 3D image sensor and / or 2D camera generate image data.

[0016] According to another embodiment, the camera module is designed to directly transmit a trigger signal to one of the 3D image sensor and the 2D camera, and to delay the transmission of the trigger signal to the other of the 3D image sensor and the 2D camera. As described above, the trigger signal initiates image acquisition, i.e., ultimately generating 3D image data and / or 2D image data. The trigger signal can originate from an evaluation module so that image generation can be correlated with, for example, an external event. In particular, the trigger signal can be generated at regular, especially constant, intervals. In principle, the generation of the trigger signal can also be implemented by the camera module.

[0017] For example, a 3D image sensor can receive a trigger signal directly or without delay, thus initiating the generation of 3D image data without delay. A 2D camera, however, can only begin generating 2D image data after a certain delay (especially a predetermined delay time). This delay can improve data transmission via the connecting cable, as described below.

[0018] Alternatively, it is also possible that the 3D image sensor and the 2D camera simultaneously receive trigger signals, thereby simultaneously acquiring images and simultaneously initiating the generation of 3D image data and 2D image data.

[0019] According to another embodiment, a delay unit is provided in the camera module to delay the trigger signal of the 3D image sensor or the 2D camera. The delay of the trigger signal caused by the delay unit is selected such that the image data generated without delay has been at least partially (or entirely) transmitted to the evaluation module via the connecting cable. This means that, for example, 3D image data from the 3D image sensor is generated directly without delay and also transmitted directly to the evaluation module via the connecting cable. Only after at least partially or entirely of the 3D image data has been transmitted will the 2D camera receive the trigger signal and begin generating 2D image data. The advantage of this is that, for example, when the 3D image data has been fully transmitted, the transmission capacity of the connecting cable can be fully utilized for the 2D image data. Thus, transmission via the connecting cable is simplified. Other advantages are that, in the camera module, it is not necessary to provide buffering (or only a small buffering) for the typically very large amount of 2D image data, thereby allowing the camera module to be designed to be smaller, more compact, and more energy-efficient.

[0020] Understandably, a 2D camera can receive the trigger signal without delay, while a 3D image sensor receives the trigger signal with a delay. In this case, it is preferable to first transmit the 2D image data via a connecting cable, and then transmit the 3D image data via a connecting cable.

[0021] In particular, the delay generated by the delay unit can be set to a fixed or constant value. This is especially possible if the data rate and size of the image data generated by the 3D image sensor and the 2D camera are known. Similarly, the data rate can be known, through which the connecting cable can transmit data; this is also known as the maximum data transmission rate.

[0022] Alternatively, it may be possible to determine the appropriate data rate and / or image data size based on the actual configuration of the camera module, and calculate the latency during operation.

[0023] In addition, alternatively or additionally, the delay unit may determine whether and / or which image data to send via the connection cable. The delay unit may be designed to, for example, forward a trigger signal after a predetermined amount of image data and / or after the image data has finished (to a camera that has not yet generated any image data).

[0024] According to another embodiment, a serializer is provided in the camera module and / or a deserializer is provided in the evaluation module, wherein the serializer is connected to the 3D image sensor and / or the 2D camera via a data connection, wherein the serializer integrates (e.g., converts) the 3D image data and / or the 2D image data into a serial data stream and transmits it via a connection cable.

[0025] Specifically, the deserializer receives a serial data stream via a connection cable and extracts 3D image data and / or 2D image data from the serial data stream. In other words, the deserializer reconstructs 3D image data and / or 2D image data from the serial data stream.

[0026] In particular, serializers, deserializers, and connecting cables can form a GMSL system (Gigabit Multimedia Serial Link System) or be built upon such a system.

[0027] In particular, the delay in the trigger signal described above allows 3D and 2D image data to arrive at the serializer sequentially, preventing data congestion on the serializer and thus maximizing throughput through the connecting cable. Furthermore, it ensures that no image data is lost.

[0028] Furthermore, the intentional delay ensures that the image data (i.e., each image) has a unique and accurate timestamp. This facilitates the proper processing of image data in the evaluation module. Additionally, this delay ensures that the maximum bandwidth or transmission rate of the connecting cable is never exceeded at any time.

[0029] According to another embodiment, the serializer and / or deserializer is designed to transmit 3D image data and 2D image data in separate virtual channels via connecting cables. Therefore, simplified processing is achieved, particularly simplified integration and extraction of image data from / from the serial data stream. The serializer and / or deserializer can provide a suitable protocol that implements the virtual channels.

[0030] According to another embodiment, the 3D image sensor is designed to generate 3D image data using a first maximum data rate, and the 2D camera is designed to generate 2D image data using a second maximum data rate. Furthermore, data transmission can be performed via a connecting cable at the maximum data transmission rate. Specifically, the first maximum data rate and / or the second maximum data rate are each greater than the maximum data transmission rate. Alternatively or additionally, the sum of the first maximum data rate and the second maximum data rate is greater than the maximum data transmission rate.

[0031] Maximum data rate is understood as the maximum data rate that a 3D image sensor or 2D camera can achieve, such as at maximum resolution, maximum scan rate, maximum color depth, and maximum scan range. The maximum data rate can exceed the maximum data transmission rate. At least temporarily, a 3D image sensor or 2D camera can generate more data than is transmitted per unit time via a connecting cable.

[0032] If the sum of the first maximum data rate and the second maximum data rate is greater than the maximum transmission data rate, then the aforementioned delay causing the transmissions to proceed sequentially is sufficient to prevent the maximum transmission data rate from being exceeded. If the first maximum data rate and / or the second maximum data rate is also individually greater than the maximum transmission data rate, then the additional measures described below may be taken.

[0033] According to another embodiment, the 2D camera is designed to generate image data only for a portion of its field of view. Therefore, the 2D camera can be designed to perform so-called "cropping." Preferably, the 2D camera natively supports cropping, i.e., only reading a portion of the 2D camera's image sensor. Performing this cropping at the image sensor level saves energy because unnecessary data is not generated. Furthermore, bandwidth savings are also possible. Additionally, it is possible to sequentially read different portions of the image sensor, i.e., display different image regions in different images. For example, the image region to be read can be changed after a corresponding trigger signal, allowing the evaluation module to reconstruct a complete image of the monitored area from the 2D image data.

[0034] According to another embodiment, a buffer memory for 3D image data, connected to a 3D sensor, is provided in the camera module. The camera module is designed so that 3D image data is written to the buffer memory at a higher data rate than the rate at which the buffer memory transmits 3D image data to the serializer and / or evaluation module. Generally, the 3D sensor transmits a very large amount of data in a very short time, a phenomenon known as burst transmission. The maximum data rate of the 3D sensor can significantly exceed the maximum transmission data rate. The data rate can then be reduced using the buffer memory, and preferably, the transmission of 3D image data is significantly extended via a connecting cable.

[0035] In particular, the 3D image sensor can transmit 3D image data via a MIPI interface, specifically to a buffer memory. The 3D image data is then slowly transmitted from the buffer memory.

[0036] In particular, the buffer memory can be part of a processor, such as a signal processor, and more particularly, a digital signal processor (DSP). More specifically, the processor performs modifications to the 3D image data, such as compression and / or extraction of depth information. The depth information can then at least partially or completely replace the previous 3D image data, wherein the modified and / or replaced 3D image data is transmitted via a connection cable.

[0037] For example, a 3D image sensor includes an integrated processing unit, such as a DSP, which calculates depth information based on raw 3D data (phase information measured from emitted light rays and subsequently returned scattered light rays). The raw 3D data can be (initial) 3D image data. Further, the processing unit can filter out invalid pixel information according to variable criteria, perform preprocessing steps (before conversion to depth information), and post-processing steps, particularly those parameterized by an evaluation module. The processing unit can add state information about the pixel data (e.g., metadata, confidence data) to the 3D image data.

[0038] By calculating depth data from raw 3D data, the amount of data can be significantly reduced, for example, by a factor of nine. This simplifies the transmission of 3D image data via connecting cables.

[0039] The implementation for the buffer memory and / or processor is also accordingly adapted to 2D image data, which can also be emitted slowly through a corresponding buffer memory. In both cases, the size of the buffer memory is determined in such a way that the buffer memory will never be filled.

[0040] However, preferably, the 2D image data is transmitted without alteration via the connecting cable and / or, in particular, without delay via a buffer memory provided for latency.

[0041] Apart from compressing the 3D image data, preferably, no changes are made to the image data in the camera module, thereby allowing the camera module to be designed to be more compact and energy-efficient. Preferably, no changes are made to the image data in the camera module that would affect the information content of the 3D and / or 2D image data (conversions performed via a serializer do not change the information content of the image data).

[0042] In particular, delay devices can also be integrated into the processor, causing the processor to also generate delays.

[0043] According to another embodiment, 3D image data and 2D image data have different formats and / or different sizes, wherein the 3D image data and / or 2D image data preferably exist in a data format that each occupies a whole byte. The transmission of different data formats introduces additional complexity; however, this has been taken into account by the aforementioned measures of virtual channels and sequentially performed transmissions. By using a whole-byte data format (e.g., RAW16 or RAW8), the bandwidth in the connection cable can be fully utilized.

[0044] According to another embodiment, the camera module includes an energy storage device, particularly a capacitor bank, which is designed to store electrical energy received via a connecting cable and to release the stored electrical energy when the energy demand of the camera module exceeds the electrical power transmitted via the connecting cable. Preferably, the energy storage device has a limiting circuit that limits the charging speed of the energy storage device.

[0045] Power transfer via the connecting cable is limited, especially during image acquisition, so the camera module may require more power than can be supplied via the cable. In this case, the extra energy needed can be drawn from the energy storage device for a short period. Once image acquisition is complete, the energy storage device can be recharged to provide power for the next image acquisition.

[0046] A limiting circuit prevents overloading of the connecting cable. The limiting circuit can be designed to allow the energy storage device to be charged at, for example, a constant or permanently set maximum charging current. Alternatively or additionally, the limiting circuit may include a sensor that compares the current energy consumption of the camera module with the maximum possible energy that the camera module can deliver, and uses the difference to charge the energy storage device (the charging current is then adjusted accordingly). In this way, optimal utilization of the energy transferred via the connecting cable can be achieved.

[0047] Preferably, the camera module is designed such that its average energy consumption is less than the maximum energy available through the connecting cable. For example, the average energy consumption is determined over several minutes during normal operation of the imaging system. Specifically, the average energy consumption is at least 60%, particularly at least 70%, and further particularly at least 80% of the maximum energy available through the connecting cable. On the other hand, the average energy consumption is at most 80%, particularly at most 90%, and further particularly at most 95% of the maximum energy available through the connecting cable. On average, the energy consumption does not exceed the maximum energy available through the connecting cable, otherwise there would be no energy reserve to charge the energy storage device.

[0048] For this reason, camera modules must operate as energy-efficiently as possible. For example, this could be achieved by 2D cameras performing pixel binning and / or by 3D sensors reducing the emission power used to transmit light signals (i.e., emitted light), especially when the monitored area of ​​the 3D sensor is reduced. Similarly, other energy-saving measures are also possible.

[0049] To transmit electrical power via the connecting cable, a separation filter can be incorporated into the camera module and / or evaluation module to separate the data transmitted via the connecting cable (i.e., image data) from the power supply signal. For example, the data can be filtered through a high-pass filter, while the power supply can be implemented using a low-pass filter.

[0050] According to another embodiment, the connecting cable is a coaxial cable or a cable with a single shielded twisted-pair line. In particular, for components electrically connected to both the camera module and the evaluation module, the coaxial cable may have only a shield and a center conductor. Similarly, the twisted-pair line may have only two conductors and may also have a shield if necessary. For data transmission and / or power transmission, preferably only the center conductor and shield are used, or only the twisted-pair line and its shield are used, generally without additional electrical connections.

[0051] Preferably, the grounding wire or shielding layer is connected directly or with low resistance to the housing of the camera module and / or evaluation module. The grounding wire or shielding layer can be connected to a safety conductor connection (PE connection). This improves the EMC compatibility of the imaging system.

[0052] As described above, the camera module and the evaluation module are arranged separately from each other, and preferably designed in a separate housing. The connecting cable can have a minimum length of, for example, 0.5m, 1m, or 2m. The connecting cable can have a maximum length of, for example, 15m, 20m, or 30m. The evaluation module and the camera module preferably each have, for example, a plug-in device (Steckmöglichkeit) disposed on their housings, for plug-in connectors for connecting the cable. In particular, the connecting cable can have two plug-in connectors, one for the camera module and the other for the evaluation module. The plug-in connectors can be detachably attached to the plug-in device.

[0053] According to another embodiment, the 3D image sensor is a TOF (Time-of-Flight) sensor or an iTOF (Indirect Time-of-Flight) sensor, particularly a laser scanner or LIDAR (LiDAR). Specifically, the 3D image sensor may have a transmitting light source that emits transmitted light into a monitored area. Within the monitored area, the transmitted light can illuminate an object, which reflects the transmitted light back in the direction of the 3D image sensor, i.e., reflects it. The reflected transmitted light, captured by the 3D image sensor, is then used to assess the light propagation time (directly or indirectly) to determine the distance to the object. The transmitted light can be emitted to different areas of the monitored area to generate a depth image of the monitored area with a large number of pixels.

[0054] According to another embodiment, the 2D camera is a monochrome or color camera, and preferably has a resolution of at least 4 megapixels, 8 megapixels, or 12 megapixels. In particular, the 2D camera may have an optical element behind which an image sensor is disposed. An image of the monitored area is projected onto the image sensor through this optical element. The image sensor may have the aforementioned resolution of at least 4 megapixels, 8 megapixels, or 12 megapixels, and may be designed as, for example, a CCD sensor or a CMOS sensor.

[0055] According to another embodiment, the 3D image sensor and the 2D camera have the same field of view, overlapping fields of view, or fields of view adjacent to each other. The aforementioned monitoring area can be a portion of the field of view. The field of view refers to the area that can be expressed using image data. Preferably, for example, the solid angles of the fields of view of the 3D sensor and the 2D camera are at least 90% the same. Preferably, the visual axes (i.e., directions) of the 3D image sensor and the 2D camera are parallel.

[0056] Another subject of the invention is a camera module comprising a time-of-flight 3D image sensor for generating 3D image data and a 2D camera for generating 2D image data, wherein the camera module is designed to operate using only a single connecting cable, wherein preferably, the power supply of the camera module is achieved solely through the connecting cable, and preferably, the camera module is designed such that 3D image data and 2D image data are transmitted solely through the connecting cable.

[0057] Another subject of the invention is an extended imaging system with an evaluation module, wherein two or more camera modules of the aforementioned type are each connected to the evaluation module via separate connecting cables. In particular, the evaluation module can be a so-called "edge device." The evaluation module can have computing means for processing image data, and may include, for example, multiple deserializers to connect multiple camera modules in parallel and receive image data from the multiple camera modules in parallel.

[0058] Finally, the present invention also relates to a method for operating an imaging system having at least one camera module and an evaluation module, wherein the camera module includes a time-of-flight 3D image sensor for generating 3D image data and a 2D camera for generating 2D image data, wherein the camera module and the evaluation module are interconnected by only one connecting cable, wherein the power supply of the camera module is achieved through (in particular, only through) the connecting cable, and the camera module transmits 3D image data and 2D image data to the evaluation module through (in particular, only through) the connecting cable. The evaluation module processes the 3D image data and the 2D image data.

[0059] The embodiments of the imaging system according to the invention are correspondingly applicable to the camera module according to the invention, the extended imaging system according to the invention, and the method according to the invention. In particular, this applies to the advantageous and preferred embodiments. Furthermore, it should be understood that, unless explicitly stated otherwise, the features and embodiments mentioned herein can be combined with each other. Attached Figure Description

[0060] The invention is described below by way of example only with reference to the accompanying drawings.

[0061] Figure 1 An imaging system with a camera module and an evaluation module is schematically shown.

[0062] Figure 2 An expanded imaging system with three camera modules is shown, all connected to the same evaluation module.

[0063] List of reference numerals

[0064] 10 Imaging System

[0065] 12 camera modules

[0066] 14 3D Image Sensors

[0067] 16 2D Cameras

[0068] 18 Light emitters

[0069] 20 emitted light

[0070] 22 Monitoring Area

[0071] 24 objects

[0072] 26 Lenses

[0073] 28 Image Sensors

[0074] 30 Image Sensors

[0075] 32 3D image data

[0076] 34 2D image data

[0077] 36 Serializer

[0078] 38 Evaluation Modules

[0079] 40 Connecting cables

[0080] 42 Deserializer

[0081] 44. Processing Results

[0082] 46. ​​Extended Imaging System

[0083] 48 processors

[0084] 50 Separation Filter

[0085] 52 Energy storage device

[0086] 54 Energy supply device

[0087] 56 Computing devices Detailed Implementation

[0088] Figure 1 An imaging system 10 with a camera module 12 (also known as a sensor head) is shown. The camera module 12 includes a time-of-flight 3D image sensor 14 and a 2D camera 16.

[0089] The 3D image sensor 14 includes a light emitter 18 that emits light 20 into a monitoring area 22. An object 24 positioned in the monitoring area 22 retracts the emitted light 20, which is then guided by the 3D image sensor through a lens 26a to an image sensor 28. The 2D camera 16 also includes a lens 26b and another image sensor 30.

[0090] The 3D image sensor 14 and the 2D camera 16 generate 3D image data 32 and 2D image data 34 in such a manner that the 3D image data 32 and 2D image data 34 are transmitted to the serializer 36.

[0091] The imaging system 10 also includes an evaluation module 38, which is connected to the camera module 12 via a single connection cable 40 (in particular, in the form of a coaxial cable).

[0092] The serializer 36 is connected to the connection cable 40 so that 3D image data 32 and 2D image data 34 can be transmitted to the evaluation module 38 via the connection cable 40.

[0093] The evaluation module 38 includes a deserializer 42, which reconstructs 3D image data 32 and 2D image data 34 based on data transmitted via the connecting cable 40. The evaluation module 38 processes the 3D image data 32 and 2D image data 34, and the processing result 44 is output through an interface (not shown) of the evaluation module 38.

[0094] Figure 2 An extended imaging system 46 with three camera modules 12 is shown, each of which is connected to the same evaluation module 38 via its own connection cable 40. Figure 2 More details about the internal structure of the camera module 12 and the evaluation module 38 are shown.

[0095] Each camera module 12 is constructed identically. It can be seen that the 3D image sensor 14 is connected to a processor 48 in the form of a digital signal processor. The processor 48 is in turn connected to a serializer 36. The processor 48 also functions as a delay unit and receives a trigger signal (referred to herein as Sync) via the serializer 36, which is then delayed and forwarded to the 2D camera 16 (referred to herein as SyncRGB). Alternatively, the 3D image sensor 14 itself can function as a delay unit and receive the trigger signal.

[0096] The processor 48 also serves as a buffer memory for the 3D image data 32, thereby slowing down the transmission of the 3D image data 32 from the 3D image sensor 14 to the serializer 36.

[0097] The serializer 36 is electrically connected to the connecting cable 40, which is also electrically connected to the separation filter 50, which separates the data transmitted via the connecting cable 40 from the current supply device. Figure 2 In this context, the current supply device is represented by the energy storage device 52. The energy storage device 52 includes a capacitor bank and a limiting circuit that limits the charging rate of the capacitor bank.

[0098] On the side of the evaluation module 38, a separate filter 50 is provided for each connection cable 40. The filter 50 is connected to a power supply device 54, which supplies power to the connection cables 40 for the camera module 12.

[0099] Data received via connection cable 40 is also transmitted from separation filter 50 to three deserializers 42, which forward the received 3D image data 32 and 2D image data 34 to the computing device 56 of evaluation module 38. Computing device 56 generates configuration signals (in... Figure 2 The description is as follows: (control) and trigger signals. Configuration and trigger signals can be transmitted from the evaluation module 38 to the camera module 12 via connection cable 40. (As described in the original text) Figure 2 As shown, the trigger signal for all camera modules 12 can be the same, so that image generation for all camera modules 12 starts at the same time.

[0100] If the trigger signal is sent to all camera modules 12 simultaneously, one of the camera modules 12 can act as the master module. Since the camera modules 12 emit emitted light 20 through the light emitter 18, there is a possibility that the different camera modules 12 may interfere with each other. To avoid this, the remaining camera modules 12 are clocked with the master module, wherein each of the remaining camera modules 12's 3D image sensors 14 uses a different delay to generate corresponding 3D image data 32. The different delays can be generated by the 3D image sensors 14. Alternatively, it is also possible that the evaluation module 38 can transmit the trigger signal to the different camera modules 12 at different times, wherein, preferably, the delays between the various camera modules 12 are the same.

[0101] Since each camera module 12 transmits image data and power via only one connection cable 40, the imaging system 10 can be used flexibly and simply. By using a single evaluation module 38 for multiple camera modules 12, the cost can be further reduced when using multiple camera modules 12.

Claims

1. An imaging system (10) having at least one camera module (12) and an evaluation module (38), characterized in that The camera module (12) includes a time-of-flight 3D image sensor (14) for generating 3D image data (32) and a 2D camera (16) for generating 2D image data (34). The camera module (12) and the evaluation module (38) are connected to each other only through a connecting cable (40). The power supply of the camera module (12) is realized through the connecting cable (40), and the camera module (12) is designed to transmit the 3D image data (32) and the 2D image data (34) to the evaluation module (38) through the connecting cable (40). The evaluation module (38) is designed to process the 3D image data (32) and the 2D image data (34).

2. The imaging system (10) according to claim 1, characterized in that, The evaluation module (38) is designed to transmit operational information to the camera module (12) via the connection cable (40).

3. The imaging system (10) according to claim 2, characterized in that, The operational information includes configuration for the camera module (12) and / or trigger signals for initiating image acquisition.

4. The imaging system (10) according to claim 3, characterized in that, The camera module (12) is designed to transmit the trigger signal directly to one of the 3D image sensor (14) and the 2D camera (16), and to transmit the trigger signal delayedly to the other of the 3D image sensor (14) and the 2D camera (16).

5. The imaging system (10) according to claim 3, characterized in that, A delay unit (48) is provided in the camera module (12) to delay the trigger signal of the 3D image sensor (14) or the 2D camera (16), wherein the delay of the trigger signal caused by the delay unit (48) is selected such that the 3D image data (32) or the 2D image data (34) generated without delay has been transmitted to the evaluation module (38) at least partially or entirely through the connection cable (40).

6. The imaging system (10) according to claim 1, characterized in that, A serializer (36) is provided in the camera module (12) and / or a deserializer (42) is provided in the evaluation module (38), wherein the serializer (36) is connected to the 3D image sensor (14) and / or the 2D camera (16) via a data connection, wherein the serializer (36) integrates the 3D image data (32) and / or the 2D image data (34) into a serial data stream and transmits it via the connection cable (40). The deserializer (42) receives the serial data stream through the connecting cable (40) and extracts the 3D image data (32) and / or the 2D image data (34) from the serial data stream.

7. The imaging system (10) according to claim 6, characterized in that, The serializer (36) and / or the deserializer (42) are designed to transmit the 3D image data (32) and the 2D image data (34) in separate virtual channels via the connection cable (40).

8. The imaging system (10) of claim 1, characterized by , The 3D image sensor (14) is designed to generate the 3D image data (32) using a first maximum data rate, and the 2D camera (16) is designed to generate the 2D image data (34) using a second maximum data rate. Data transmission can be performed at the maximum data transmission rate via the connecting cable (40). Wherein, the first maximum data rate and / or the second maximum data rate are respectively greater than the maximum transmission data rate, and / or wherein the sum of the first maximum data rate and the second maximum data rate is greater than the maximum transmission data rate.

9. The imaging system (10) according to claim 1, characterized in that, wherein, The 2D camera (16) is designed to generate the image data (34) only for a portion of the field of view of the 2D camera (16).

10. The imaging system (10) according to claim 6, characterized in that, A buffer memory for the 3D image data (32) connected to the 3D image sensor (14) is provided in the camera module (12), wherein the camera module (12) is designed such that the 3D image data (32) is written to the buffer memory at a higher data rate than the data rate at which the buffer memory transmits the 3D image data (32) to the serializer (36).

11. The imaging system (10) according to claim 1, characterized in that, The 3D image data (32) and the 2D image data (34) have different formats and / or different sizes, wherein the 3D image data (32) and / or the 2D image data (34) exist in a data format that each occupies a whole byte.

12. The imaging system (10) according to claim 1, characterized in that, The camera module (12) includes an energy storage device (52) designed to store electrical energy received through the connecting cable (40) and to release the stored electrical energy when the energy demand of the camera module (12) exceeds the electrical power transmitted through the connecting cable (40). The energy storage device (52) has a limiting circuit that limits the charging speed of the energy storage device.

13. The imaging system (10) according to claim 12, characterized in that, The energy storage device (52) is a capacitor bank.

14. The imaging system (10) according to claim 1, characterized in that, The connecting cable (40) is a coaxial cable or a cable with a single shielded twisted pair.

15. The imaging system (10) according to claim 1, characterized in that, The 3D image sensor (14) is a TOF sensor or an iTOF sensor, and / or the 2D camera (16) is a monochrome camera or a color camera.

16. The imaging system (10) according to claim 15, characterized in that, The 3D image sensor (14) is a laser scanner or LIDAR.

17. The imaging system (10) according to claim 15, characterized in that, The 2D camera (16) has a resolution of at least 4 million pixels or 8 million pixels.

18. The imaging system (10) according to claim 1, characterized in that, The 3D image sensor (14) and the 2D camera (16) have the same field of view, overlapping fields of view, or fields of view adjacent to each other.

19. A camera module (12) comprising a time-of-flight 3D image sensor (14) for generating 3D image data (32) and a 2D camera (16) for generating 2D image data (34). wherein The camera module (12) is designed to operate using only one connecting cable (40), wherein the power supply of the camera module (12) is achieved through the connecting cable (40), and the camera module (12) is designed to transmit the 3D image data (32) and the 2D image data (34) through the connecting cable (40).

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