Imaging device, imaging system and method for operating an imaging system

Abstract

The invention relates to an imaging device (10; 110), in particular an endoscope device, for stereoscopic image generation, wherein the imaging device (10; 110) has a shaft (12; 112) which defines a longitudinal axis (14; 114) and at least one optical viewing direction unit (58, 158) for generating a viewing angle (18) of greater than 0° with respect to the longitudinal axis (14; 114). It is proposed that the imaging device (10; 110) has a periscope unit (20; 120) for combining at least two beam paths (22, 24; 122, 124) for use in stereoscopic image generation, wherein the viewing direction unit (58, 158) is rotationally fixed with respect to the shaft (12; 112) and the periscope unit (20; 120) is rotatable relative to the shaft (12; 112) about the longitudinal axis (14; 114).

Description

[0001] The present invention relates to an imaging device for stereoscopic image generation, comprising a shaft defining a longitudinal axis and at least one viewing direction unit for generating a viewing angle greater than 0° with respect to the longitudinal axis. The present invention further relates to an imaging system with such an imaging device and a method for operating such an imaging device.

[0002] The development of modern 3D endoscopes places high demands on the precise alignment of their optical systems. Endoscopes are known from the prior art that use two spatially separated optical systems for stereoscopic image generation, capturing an object point from different angles. In these endoscopes with two optical systems, the two optical systems must always be aligned horizontally to realistically reproduce human depth perception. Besides endoscopes with two optical systems, stereo endoscopes with a single optical relay system are also known from the prior art, for example, US 9,883,788 B2.Furthermore, US 7,180,660 B2 and US 2016 / 0057405 A1 each disclose a stereoscopic imaging device that uses a lens to split an image captured from an object into different beam channels and, with subsequent optical units, directs the beam channels to different image sensors. When the imaging devices are rotated, the lens and the optical units rotate accordingly.

[0003] However, endoscopes with an oblique viewing angle (DOV ≠ 0°) present a particular challenge: When the endoscope shaft is rotated, as is common practice during medical procedures to change the viewing angle, the alignment of the two optical systems changes. This leads to faulty stereoscopy and impairs the quality of the 3D imaging. This problem significantly limits the application possibilities of oblique-viewing 3D endoscopes.

[0004] One solution, known from US 9,798,131 B2, involves changing the viewing direction of the endoscope by rotating a distal prism while the two optical systems remain in their horizontal orientation. EP 3 367 155 B1 also discloses a device for capturing a stereo image with two optical systems, in which a change in the viewing direction is coupled to a translational movement of a lens by means of a cam mechanism. However, the use of two separate optical systems in 3D endoscopes presents a challenge in terms of space requirements and design complexity. Each optical system requires its own optical elements, light guidance, and alignment, resulting in a larger and more technically complex design overall.This is particularly problematic in medical applications where available space in the distal region of the endoscope is limited. This makes miniaturization more difficult and simultaneously increases the susceptibility to manufacturing defects and mechanical instabilities, which can impair reliability and functionality.

[0005] The object of the present invention is to provide an imaging device with a particularly compact structure and simplified construction, which at least partially solves the aforementioned problems according to the prior art and advantageously ensures a three-dimensional representation in different viewing directions of the imaging device.

[0006] This problem is solved according to the invention by an imaging device having the features of claim 1 and a method for operating an imaging device according to claim 13. Advantageous embodiments and further developments of the invention can be found in the dependent claims.

[0007] According to the invention, an imaging device, in particular an endoscope device, is provided for stereoscopic image generation. The imaging device has a shaft that defines a longitudinal axis and at least one optical viewing unit for generating a viewing angle greater than 0° with respect to the longitudinal axis. The imaging device also has a periscope unit for combining at least two beam paths for use in stereoscopic image generation. Furthermore, the imaging device has a movement unit. The viewing unit is rotationally fixed with respect to the shaft, and the periscope unit is arranged to rotate about the longitudinal axis relative to the shaft. The movement unit is configured to hold the periscope unit in a horizontal position when the shaft is rotated about the longitudinal axis.

[0008] By using a periscope unit that is rotatable relative to the shaft and, in particular, the viewing direction unit, rotation of the shaft can be compensated for when changing the viewing direction with respect to the alignment of the two beam paths for stereoscopic image generation. This enables suitable stereoscopic image generation at any rotation angle of the shaft around its longitudinal axis, and thus especially at different viewing angles. By combining the two beam paths, it is not necessary to use two separate optical systems. The use of only one optical system is sufficient for suitable stereoscopic image generation at different rotation angles of the shaft using the imaging device according to the invention. Thus, an imaging device with a particularly simple and space-saving design can be provided.This helps to minimize a number of manufacturing and assembly-related error sources.

[0009] The imaging device can be configured as an endoscope, which may be part of an endoscope or comprise the entire endoscope. Alternatively, the imaging device can also be configured as an exoscope, in particular as part of an exoscope, or comprise the entire exoscope. The imaging device is intended for stereoscopic image generation, for example, as a stereoendoscope or stereoexoscope. The imaging device can be configured to capture images of an object point from different perspectives to enable stereoscopic image generation. The imaging device can be intended for medical or non-medical applications.

[0010] The viewing unit can be located at a distal end of the shaft. This arrangement is equivalent to placing the viewing unit at the distal end of the shaft. In other words, the viewing unit does not necessarily have to be at the distal tip of the shaft. Distally in front of the viewing unit, another optical element, such as a lens, a protective glass, or the like, can be located. The viewing unit can have one or more reflective flat or curved surfaces, for example, within or on a prism, or between several prisms. The two beam paths mentioned above can emerge from a proximal side of the viewing unit.

[0011] The periscope unit can be arranged on a proximal side with respect to the viewing unit. The periscope unit can be configured to combine the two beam paths, particularly those distal to the periscope unit, into a common beam path, particularly those proximal to the periscope unit. In other words, the periscope unit can be configured to combine the two beam paths, which are spaced apart at their optical input, into the common beam path at its optical output.

[0012] Within the scope of the present invention, the imaging device may comprise only an optical system, which may be configured to transmit light from the combined beam path originating proximally from the periscope unit towards a proximal end of the imaging device, preferably towards a sensor unit. The optical system may be configured as a rod lens system or another relay lens system. Alternatively, the imaging device may also be configured without an optical system for transmitting light from the combined beam path from the periscope unit towards the proximal end of the imaging device. For the purposes of this invention, the term "beam path" is used to describe the path taken by light rays in an optical setup.

[0013] The periscope unit can be configured to redirect at least one of the two beam paths, preferably at least twice, in order to combine them. For redirecting the beam paths, the periscope unit can have at least one deflecting element, preferably at least two. The at least one deflecting element can be designed as a reflective element, for example as a mirror element, a dispersion element, or the like. For example, at least one of the two beam paths can be redirected by the periscope unit in a first deflection into a direction angled to the longitudinal axis, in particular substantially perpendicular to it, and in a second deflection into a direction at least approximately parallel to the longitudinal axis. The beam path combined by the periscope unit can run substantially parallel to the longitudinal axis.Preferably, the combined beam path can run at least partially along the longitudinal axis.

[0014] In the context of this disclosure, a proximal section or proximal side is a section or side that is located closer to the observer / user and further away from the field of vision / patient than a distal section or distal side. Likewise, a distal section or distal side is a section or side that is located closer to the field of vision / patient and further away from the observer / user than a proximal section or proximal side. Accordingly, distal can also be described as being close to the patient, facing the patient, and / or farther from the observer. Proximal can also be described as being farther from the patient, facing away from the patient, and / or close to the observer. When used as an endoscopic instrument, the distal end of the shaft is typically inserted into the body to allow for observations.At least the proximal end of the instrument protrudes from the body, because that is where the operator handles and controls it.

[0015] The two beam paths at the optical input of the periscope unit can be spaced apart from each other. An object point can be viewed and, in particular, captured from two different perspectives via these two beam paths located distal to the periscope unit. A first image can be captured and / or generated via the first beam path, and a second image can be captured and / or generated via the second beam path. The first and second images can be combined for stereoscopic image generation.

[0016] The viewing direction unit and / or the periscope unit can be arranged in the shaft. The periscope unit can be rotatably mounted in the shaft about the longitudinal axis. For the purposes of this explanation of the invention, the phrase "the viewing direction unit is rotationally fixed with respect to the longitudinal axis" means rotationally fixed, at least with respect to rotations of the shaft about the longitudinal axis. Within the scope of the present invention, the imaging device can be configured such that the viewing angle between the viewing direction and the longitudinal axis is either fixed or variable.

[0017] The movement unit is configured to hold the periscope unit in a horizontal position when the shaft is rotated about its longitudinal axis. This ensures that the quality of the stereoscopic image generation is maintained even when the viewing direction is changed by rotating the shaft about its longitudinal axis. In a preferred embodiment of the invention, the movement unit can be configured to rotate the periscope unit by an angle about its longitudinal axis, the magnitude of which corresponds to, and is in particular opposite to, the rotation angle of the shaft, especially the viewing direction unit, about its longitudinal axis.The phrase "the periscope unit is held in a horizontal position" in the context of the invention means that the parallax between the two beam paths, particularly those distal to and spaced apart from the periscope unit, runs horizontally. This advantageously ensures stereoscopic image generation even when the shaft rotates and thus when the viewing direction changes.

[0018] The motion unit can, for example, have active and / or passive motion mechanisms. For example, the motion unit can have a drive, in particular a hydraulic, electric, or pneumatic drive, especially a rotary actuator, for rotating the periscope unit about its longitudinal axis. A passive motion mechanism can, for example, be based on spring tension, gravity, elasticity, or the like. The motion unit can have position sensors for determining the rotation angle of the shaft, in particular the viewing unit, about its longitudinal axis. The motion unit can have a control unit configured to control the motion mechanism depending on the rotation angle of the shaft, in particular the viewing unit, about its longitudinal axis, as detected in particular by the position sensors.The motion unit can be located at least partially within the shaft, for example, on an inner wall of the shaft. The periscope unit can be rotatable about its longitudinal axis via the motion unit. Alternatively, the imaging device can have a separate bearing for the periscope unit. The motion unit can drive the periscope unit to rotate relative to the shaft.

[0019] Within the scope of the invention, the periscope unit may provide at least two distinguishable optical channels at its optical output. Preferably, the beam path combined by the periscope unit may have the two distinguishable optical channels. The optical output of the periscope unit may be located on a proximal side of the periscope unit. For the purposes of this invention, an "optical channel" is understood to mean light rays that propagate along a specific beam path, for example, one of the two beam paths already mentioned and / or the combined beam path, and can thereby transport image information relating to an object.

[0020] A first optical channel of the two optical channels can be provided via a first beam path of the two beam paths, and a second optical channel of the two optical channels via a second beam path of the two beam paths. The two images of an object point from two different perspectives can be transmitted via the optical channels for stereoscopic image generation. For example, the first optical channel can transmit the first image and the second optical channel the second image. Advantageously, the images for stereoscopic image generation can be acquired and transmitted in a horizontal position of the stereoscopic unit, particularly the two beam paths, even when the shaft is rotated around its longitudinal axis. This enables particularly high-quality stereoscopic image generation even when the viewing direction changes, while simultaneously allowing for a particularly compact design of the imaging device.

[0021] According to a further development of the invention, the periscope unit can be provided with at least one filter, in particular the one already mentioned, to define a beam characteristic with respect to at least one of the optical channels. This allows for a particularly simple and reliable differentiation of the optical channels. The filter can, for example, be arranged in the first beam path or in the second beam path to define the beam characteristic of the first optical channel or the second optical channel, respectively. In a preferred embodiment, the periscope unit can have two filters to define a beam characteristic of the two optical channels. A first filter can, for example, be arranged in the first beam path to define the beam characteristic of the first optical channel.A second filter can, for example, be placed in the second beam path to determine the beam characteristics of the second optical channel.

[0022] Distinguishable optical channels can have different physical properties, particularly apart from information required for image generation. For example, the distinguishable optical channels may have different wavelengths and / or different polarizations. According to a preferred embodiment of the invention, the optical channels can form different color channels, i.e., they may have different wavelengths or wavelength ranges. For example, the first optical channel may be a blue-red color channel and the second optical channel a green color channel. The different color channels allow the optical channels to be distinguished on the combined beam path, so that images from different viewpoints can be transmitted via the combined beam path for stereoscopic image generation.Alternatively or additionally, the optical channels can form different polarization channels. In other words, the optical channels can be distinguished from one another by their polarization. Furthermore, the distinguishability can alternatively be achieved by at least one shutter diaphragm arranged on the two beam paths, whereby the acquisition of the images for stereoscopic image generation can depend on the shutter status of the two beam paths. For example, a first image from a first viewpoint can be acquired with the second beam path blocked by the shutter diaphragm, and a second image from a second viewpoint can be acquired with the first beam path blocked by the shutter diaphragm.

[0023] According to a further development of the invention, the at least one filter can be configured as a dichroic beam splitter. Alternatively, the at least one filter can be configured as a color filter or as a polarization splitter. This allows the beam characteristics to be defined with particular precision. Such filters can simultaneously be used as deflection elements for the beam paths. Dichroic beam splitters, due to their transmission and reflection properties, offer particularly flexible application.

[0024] Within the scope of the invention, it can be provided that the at least one filter is transparent to one of the two optical channels. For example, the filter can be configured to deflect the first optical channel, in particular to reflect it, and to transmit the second optical channel. According to an embodiment of the invention, it can be provided that the periscope unit deflects only one of the two beam paths. For example, the first beam path, which preferably provides the first optical channel, can run at a distance from the longitudinal axis, and the second beam path, which preferably provides the second optical channel, and in particular the combined beam path, can run on the longitudinal axis. Thus, a particularly simple design of the periscope unit is sufficient to enable stereoscopic image generation.This reduces both the number of possible sources of error regarding the precision of the optical setup of the imaging device and its costs.

[0025] According to a further development of the invention, the imaging device can include a sensor unit for detecting the two optical channels. The sensor unit can be connected to a processing unit of the imaging system. The processing unit can be configured to process the images detected by the sensor unit for stereoscopic image generation. According to one embodiment, the sensor unit can include a single image sensor. The image sensor can be configured to detect the combined beam path. The image sensor can be configured to resolve the combined beam path according to the optical channels. Thus, a single image sensor can be sufficient to detect the images for stereoscopic image generation. For example, the image sensor can be configured as an RGB sensor to detect a green color channel and a red-blue color channel. The image sensor can include a Bayer filter.The image sensor can, for example, be arranged in such a way that the longitudinal axis intersects the image sensor.

[0026] According to one embodiment of the invention, the imaging device may include a beam splitter located upstream of the sensor unit, which divides the combined beam paths into their distinguishable optical channels. The beam splitter may, for example, be configured as a dichroic beam splitter. The beam splitter may be configured, for example, to deflect at least one of the two optical channels. For example, the beam splitter may be configured to be transparent to the first optical channel and to deflect the second optical channel. The sensor unit may have a dedicated image sensor for each of the beam paths divided into distinguishable optical channels. The image sensors may be configured as CCD sensors, CMOS sensors, or the like.Particularly simple image sensors can be used to capture the two optical channels, especially the two images.

[0027] The invention further relates to an imaging system with the imaging device according to the invention as described above. The imaging system can be configured as an endoscopy system or as an exoscopy system. Thus, an imaging system can be provided which reliably enables stereoscopic image generation even when the viewing direction changes. By using the imaging device according to the invention in the imaging system, a particularly compact system can be provided. The imaging system can include a display. For combining the images transmitted via the two beam paths and acquired by means of the sensor unit for stereoscopic image generation, the imaging system can include the processing unit. The processing unit can comprise at least one processor and one memory element, as well as an operating program stored on the memory element.The storage element can be a digital storage medium, such as a memory chip or the like. The processing unit can be part of the imaging device or separate from it. The imaging device can be connected to the display via the processing unit. The processing unit can be configured to generate a stereoscopic image for output on the display. The display can be a monitor or the like. The processing unit can be connected to the control unit of the motion unit via data and / or control technology. For example, the processing unit and the control unit can be at least partially integrated, i.e., they can share common components.

[0028] Furthermore, the invention relates to a method for operating an imaging device for stereoscopic image generation, in particular of the type described above. In a process step, especially a capture step, images from different perspectives can be transmitted to the sensor unit via the two beam paths and the two distinguishable optical channels. For this purpose, the two beam paths can be combined into a common beam path by means of the periscope unit. By means of the processing unit, the images captured by the sensor unit can be combined to generate a stereoscopic image and, in particular, displayed.

[0029] In a process step, particularly a rotation step, the viewing direction of the imaging device can be changed by rotating the shaft, especially the viewing direction unit, about the longitudinal axis. The viewing direction can be defined by the viewing angle and a rotation angle of the shaft, especially the viewing direction unit, about the longitudinal axis. According to the method according to the invention, the periscope unit is rotated relative to the shaft when the shaft is rotated about the longitudinal axis. Within the scope of the invention, it can be provided that the periscope unit is rotated such that a plane of two beam paths passing through the periscope unit, especially the two beam paths mentioned above, is aligned at least approximately horizontally. After the periscope unit has been aligned, another acquisition step can be performed.The processing unit can be configured to rotate the assembled stereoscopic image before displaying it, for example, depending on the rotation angle of the shaft, and in particular to compensate for the rotation of the shaft. Such a method according to the invention allows for reliable stereoscopic image generation even when the viewing direction changes. Furthermore, the method according to the invention enables a particularly compact design of the imaging device.

[0030] The devices and methods disclosed herein are not intended to be limited to the application and embodiment described above. In particular, to achieve a functionality described herein, they may include a different number of individual elements, components, units, and process steps than specified herein.

[0031] It is specifically pointed out that all features and properties described in relation to a device, as well as methods, can be applied analogously to methods and, within the meaning of the invention, can also be used as method steps and are considered disclosed as such. Likewise, method steps disclosed within the scope of this invention description are to be regarded as device features that can be used in a device. This means that structural features, i.e., device-related features, mentioned in relation to methods can also be considered, claimed, and likewise included in the disclosure within the scope of the device claims.

[0032] The present invention is described below by way of example with reference to the accompanying figures. The figures, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and use them meaningfully in combination within the scope of the claims.

[0033] If more than one instance of any of the components described below exists, only one of them may be marked with a reference symbol in the figures and description. The description of this instance can then be applied to the other instances of the component. If objects are named using numerical terms, such as first, second, third object, etc., these serve to identify and / or classify objects. Therefore, for example, a first object and a third object cannot be included, but a second object cannot. However, a number and / or sequence of objects could also be derived from numerical terms.

[0034] They show: Fig. 1 a schematic representation of an imaging system with a display, a computing unit and an imaging device, Fig. 2 a schematic representation of an optical setup of the imaging device Fig. 1, Fig. 3 a schematic representation of a periscope unit of the imaging device from the Fig. 1 and Fig. 2 in a distal front view showing the arrangement of two spaced-apart beam paths through the periscope unit, Fig. 4. A schematic sequence of a procedure for operating the imaging device from the Fig. 1 and Fig. 2, Fig. 5 a schematic representation of an optical setup of an imaging device in an alternative embodiment, and Fig. 6 a schematic representation of a periscope unit of the imaging device Fig. 5 in a distal frontal view showing the arrangement of two spaced-apart beam paths through the periscope unit.

[0035] Fig. Figure 1 shows an overview of an imaging system 46 with an imaging device 10 for stereoscopic image generation, with a computing unit 54 and with a display 56, which is designed as a monitor.

[0036] The imaging device 10 is designed as an endoscope, in particular as a stereo endoscope. The imaging device 10 has a shaft 12 which defines a longitudinal axis 14.

[0037] The imaging device 10 is configured to capture images of an object point from different perspectives in order to enable stereoscopic image generation. The processing unit 54 is configured to combine the images captured by the imaging device 10 from different perspectives for stereoscopic image generation. The processing unit 54 comprises a processor (not shown here) and a memory element (not shown here), as well as an operating program stored on the memory element. The memory element is designed as a digital storage medium, for example, a memory chip or the like. The processing unit 54 is designed separately from the imaging device 10. Alternatively, the processing unit 54 can also be part of the imaging device 10. The display 56 is connected to the processing unit 54 via data transmission.The computing unit 54 is set up to generate a stereoscopic image for output on the display 56.

[0038] With reference to Fig. 2. The imaging device 10 has at least one optical viewing unit 58 for generating a viewing angle greater than 0° with respect to the longitudinal axis 14. The viewing unit 58 has two prisms 16, 60. Alternatively, the viewing unit 58 can also have only one prism 16, 60, more than two prisms 16, 60, or other deflecting elements for generating the viewing angle greater than 0° with respect to the longitudinal axis 14. The viewing unit 58 is arranged at a distal end 64 of the shaft 12. Distally in front of the viewing unit 58, a plano-concave lens 66 is arranged, particularly for achieving a desired imaging effect. Two beam paths 22, 24 emerge from a proximal side of the viewing unit 58. The beam path within the viewing unit 58 and on a distal side of the viewing unit 58 is not shown.

[0039] The imaging device 10 has a periscope unit 20 for combining the two beam paths 22, 24 for use in stereoscopic image generation. The periscope unit 20 is arranged on a proximal side with respect to the viewing direction unit 58. The periscope unit 20 is configured to combine the two beam paths 22, 24 into a common beam path 68, which is located on the proximal side with respect to the periscope unit 20. The two beam paths 22, 24 are spaced apart from each other at an optical input 80. The periscope unit 20 is configured to combine the two beam paths 22, 24 into a common beam path 68 at its optical output 28.

[0040] The two distal and spaced beam paths 22, 24, relative to the periscope unit 20, allow an object point to be viewed and captured from two different perspectives. A first image can be captured and generated via a first beam path 22 of the two beam paths 22, 24, and a second image can be captured and generated via a second beam path 24 of the two beam paths 22, 24, whereby the first and second images can be combined for stereoscopic image generation.

[0041] The periscope unit 20 is configured to combine the two beam paths 22, 24 by redirecting them. The periscope unit 20 is configured to redirect each of the two beam paths 22, 24 at two points. In a first redirection, the periscope unit 20 is configured to redirect the two beam paths 22, 24 in a direction perpendicular to the longitudinal axis 14. In a second redirection, the periscope unit 20 can redirect the two beam paths 22, 24 in a direction parallel to the longitudinal axis 14. The periscope unit 20 has several deflection elements 74 for redirecting the beam paths 22, 24. For the first redirection, each beam path 22, 24 is assigned a deflection element 74 designed as a mirror 76. For the second deflection, each beam path 22, 24 is assigned a deflection element 74 designed as a dichroic beam splitter 78.

[0042] The imaging device 10 comprises only one optical system 70 for transmitting the combined beam path 68 emanating from the periscope unit 20 towards a proximal end 72 of the imaging device 10. The optical system 70 is configured to transmit the combined beam path 68 to a sensor unit 38 of the imaging device 10. The optical system 70 is configured as a rod lens system or another relay lens system. Alternatively, the imaging device 10 can also be configured without an optical system 70.

[0043] The viewing unit 58 is arranged so as to be rotationally fixed relative to the shaft 12. The periscope unit 20 is arranged to rotate about the longitudinal axis 14 relative to the shaft 12. The viewing unit 58 and the periscope unit 20 are arranged within the shaft 12.

[0044] The imaging device 10 has a movement unit 26 which is configured to hold the periscope unit 20 in a horizontal position when the shaft 12 is rotated about the longitudinal axis 14. The movement unit 26 is configured to rotate the periscope unit 20 about the longitudinal axis 14 by an angle which is equal in magnitude to and opposite in direction to the rotation angle of the shaft 12, in particular the viewing unit 58, about the longitudinal axis 14.

[0045] The motion unit 26 includes a rotation actuator (not shown) for rotating the periscope unit 20 about the longitudinal axis 14. The rotation actuator is, for example, an electric rotary actuator. Alternatively, the rotation actuator can also be hydraulically or pneumatically driven or based on a passive movement mechanism. The motion unit 26 includes a position sensor (not shown) for determining the rotation angle of the shaft 12, in particular the viewing unit 58, about the longitudinal axis 14. The motion unit 26 includes a control unit (not shown) which is configured to control the rotation actuator depending on the rotation angle of the shaft 12, in particular the viewing unit 58, with respect to the longitudinal axis 14, as determined in particular by the position sensor. The motion unit 26 is arranged in the shaft 12.The movement unit 26 is connected to the shaft 12 and serves as a bearing for the periscope unit 20.

[0046] The periscope unit 20 provides two distinguishable optical channels 30, 32 at its optical output 28. The combined beam path 68 has the two distinguishable optical channels 30, 32. The optical output 28 is located on a proximal side of the periscope unit 20.

[0047] A first optical channel 30 of the two optical channels 30, 32 is provided via a first beam path 22 of the two beam paths 22, 24, and a second optical channel 32 of the two optical channels 30, 32 is provided via a second beam path 24 of the two beam paths 22, 24. The two images of an object point from two different perspectives can be transmitted via the optical channels 30, 32 for stereoscopic image generation. For example, the first optical channel 30 can transmit the first image and the second optical channel 32 the second image.

[0048] The periscope unit 20 has two filters 34, 36 to define a beam characteristic with respect to the two optical channels 30, 32. The filters 34, 36 are configured as dichroic beam splitters 78. The filters 34, 36 are formed by the deflecting elements 74, which are also configured as dichroic beam splitters 78. A first filter 34 is arranged in the first beam path 22 to define the beam characteristic of the first optical channel 30. A second filter 36 is arranged in the second beam path 24 to define the beam characteristic of the second optical channel 32.

[0049] Due to filters 34 and 36, optical channels 30 and 32 have different color channels. Alternatively or additionally, optical channels 30 and 32 can have different polarization channels. The first optical channel 30 is a blue-red color channel, and the second optical channel 32 is a green color channel. These different color channels allow optical channels 30 and 32 to be distinguished on the combined beam path 68, enabling the transmission of images from different viewpoints for stereoscopic image generation via the combined beam path 68. Alternatively or additionally, optical channels 30 and 32 can have different polarization channels.

[0050] The imaging device 10 includes the sensor unit 38 for detecting the two optical channels 30 and 32. The sensor unit 38 comprises a single image sensor 38. The image sensor 38 is configured to detect the combined beam path 68. The image sensor 38 is configured to resolve the combined beam path 68 according to the optical channels 30 and 32. The image sensor 38 includes a Bayer filter (not shown here). The sensor unit 38 is connected to the processing unit 54. The processing unit 54 is configured to process the images detected by the sensor unit 38 to generate a stereoscopic image. The image sensor 38 is arranged such that the longitudinal axis 14 intersects the image sensor 38.

[0051] Fig. Figure 4 shows a schematic sequence of a procedure for operating the imaging device 10.

[0052] In one process step, in particular in a capture step 48, images from different perspectives are transmitted via the beam paths 22, 24 to the sensor unit 38 via the two distinguishable optical channels 30, 32 and captured. The processing unit 54 generates a stereoscopic image from the images of the two optical channels 30, 32 and displays it on the display 56.

[0053] In a process step, in particular in a rotation step 50, the viewing direction 62 of the imaging device 10 is changed by rotating the shaft 12, in particular the viewing direction unit 58, about the longitudinal axis 14. The viewing direction 62 is defined by the viewing angle 18 and a rotation angle of the shaft 12, in particular the viewing direction unit 58, about the longitudinal axis 14. In the rotation step 50, the periscope unit 20 is rotated about the longitudinal axis 14 relative to the shaft 12. The periscope unit 20 is rotated such that a plane 52 of the two beam paths 22, 24 passing through the periscope unit 20 is aligned at least approximately horizontally (see Figure 50). Fig. 3).

[0054] Fig. Figure 5 shows an optical setup of an imaging device 110 for stereoscopic image generation in a further embodiment. The imaging device 110 has a shaft 112 which defines a longitudinal axis 114. The imaging device has at least one viewing direction unit 158 ​​for generating a viewing angle greater than 0° with respect to the longitudinal axis 114. The imaging device 110 has a periscope unit 120 for combining two beam paths 122, 124 for use in stereoscopic image generation. The beam paths 122, 124 emerge on a proximal side of the viewing direction unit 158. The beam path within the viewing direction unit 158 ​​and on a distal side of the viewing direction unit 158 ​​is not shown.

[0055] The image generation unit 158 ​​is arranged so as to be rotationally fixed to the shaft 112. The periscope unit 120 is arranged to rotate about the longitudinal axis 114 relative to the shaft 112. The periscope unit 120 has two distinguishable optical channels 130, 132 at its optical output 128.

[0056] The periscope unit 120 includes a filter 134 to define a beam characteristic with respect to at least one of the optical channels 130, 132. The periscope unit 120 deflects only one of the two beam paths 122, 124, and the periscope unit 120 has only two deflection elements 174. A first deflection element 174 is designed as a mirror 176 and is arranged in a first beam path 122. A second deflection element 174 is formed by the filter 134. The filter 134 is designed as a dichroic beam splitter. Both beam paths 122, 124 interact with the filter 134. The filter 134 is transparent to the second optical channel 132.

[0057] The first beam path 122 runs at least distally to the periscope unit 120, spaced away from the longitudinal axis 114. The second beam path 124 runs along the longitudinal axis 114. The periscope unit 120 deflects the first beam path 122, so that the two beam paths 122, 124 are combined into a common beam path.

[0058] In the Fig. In the distal front view of the periscope unit 120 shown in Figure 5, the two spaced-apart beam paths 122, 124 are shown. These span a plane 152, which is kept at least approximately horizontal by a rotation of the periscope unit 120 about the longitudinal axis 114 in the opposite direction to a rotation of the shaft 112 about the longitudinal axis 114 (see Figure 5). Fig. 6) The rotation of the periscope unit 120 can be generated by a motion unit 126.

[0059] The imaging device 110 has a sensor unit 138 for detecting the two beam paths 122, 124. The imaging device 110 has a beam splitter 144 located upstream of the sensor unit 138, which splits the combined beam paths 122, 124 into their distinguishable optical channels 130, 132. The beam splitter 144 is designed as a dichroic beam splitter. The beam splitter 144 is configured to deflect the two optical channels 130, 132 in different directions. The beam splitter 144 is transparent to the first optical channel 132.

[0060] The sensor unit 138 has a dedicated image sensor 140, 142 for each of the beam paths 122, 124, which are divided according to distinguishable optical channels 130, 132. The image sensors 140, 142 are designed as CMOS, CCD sensors or the like.

[0061] The periscope unit 120 can also be combined with a single image sensor capable of resolving according to optical channels 130 and 132. Furthermore, the periscope unit 20 can also be combined with the beam splitter 144 and the two image sensors 140 and 142. Reference symbol list 10, 110 Imaging device 12, 112 shaft 14, 114 Longitudinal axis 16 prisms 18 perspectives 20, 120 periscope units 22, 122 Beam path 24, 124 Beam path 26, 126 movement unit 28, 128 optical output 30, 130 optical channel 32, 132 optical channel 34, 134 filters 36 filters 38 image sensor 140 image sensor 142 image sensor 144 beam splitters 46 Imaging system 48 Recording step 50 rotation steps 52, 152 level 54 computing units 56 ads 58, 158 View direction unit 60 prism 62 View direction 64 distal end 66 lens 68 Beam path 70 optical system 72 proximal end 74, 174 Deflection element 76,176 mirrors 78 dichroic beam splitter 80 optical input

Claims

Imaging device (10; 110), in particular endoscope device, for stereoscopic image generation, comprising: a shaft (12; 112) defining a longitudinal axis (14; 114), at least one optical viewing unit (58, 158) for generating a viewing angle (18) of greater than 0° with respect to the longitudinal axis (14; 114), a periscope unit (20; 120) for combining at least two beam paths (22, 24; 122, 124) for use in stereoscopic image generation, and a movement unit (26; 126), wherein the viewing unit (58, 158) is rotationally fixed with respect to the shaft (12; 112) and the periscope unit (20; 120) is rotatably arranged relative to the shaft (12; 112) about the longitudinal axis (14; 114), and the movement unit (26; 126) is designed to keep the periscope unit (20; 120) in a horizontal position when the shaft (12; 112) is rotated about the longitudinal axis (14; 114). Imaging device (10; 110) according to claim 1, wherein the periscope unit (20; 120) provides at least two distinguishable optical channels (30, 32; 130, 132) at its optical output (28; 128). Imaging device (10; 110) according to claim 2, wherein the optical channels (30, 32; 130, 132) have different color channels and / or different polarization channels. Imaging device (10; 110) according to claim 2 or 3, wherein the periscope unit (20; 120) has at least one filter (34, 36; 134) to define a beam characteristic with respect to at least one of the optical channels (30, 32; 130). Imaging device (10; 110) according to claim 4, wherein the filter (34, 36; 134) is designed as a dichroic beam splitter. Imaging device (10; 110) according to one of claims 4 or 5, wherein the filter (34, 36; 134) is designed to be transparent for one of the two optical channels (30, 32; 130, 132). Imaging device (110) according to one of the preceding claims, wherein the periscope unit (120) deflects only one of the two beam paths (122, 124). Imaging device (10; 110) according to one of claims 2 to 6, further comprising a sensor unit (38; 138) for detecting the two optical channels (30, 32; 130, 132). Imaging device (10) according to claim 8, wherein the sensor unit (38) comprises a single image sensor, in particular with a Bayer filter. Imaging device (110) according to claim 8, with a beam splitter (144) positioned upstream of the sensor unit (138), which divides the combined beam paths (122, 124) according to their distinguishable optical channels (130, 132). Imaging device (110) according to claim 10, wherein the sensor unit (138) has a dedicated image sensor (140, 142) for each of the beam paths (122, 124) divided according to distinguishable optical channels (130, 132). Imaging system (46), in particular endoscopy system, comprising an imaging device (10; 110) according to one of the preceding claims. Method for operating an imaging device (10; 110) for stereoscopic image generation, in particular according to one of claims 1 to 11, comprising: a shaft (12; 112) defining a longitudinal axis (14; 114), at least one optical viewing unit (58, 158) for generating a viewing angle (18) of greater than 0° with respect to the longitudinal axis (14; 114), and a periscope unit (20; 120) for combining at least two beam paths (22, 24; 122, 124) for use in stereoscopic image generation, wherein the viewing unit (58; 158) is arranged to be rotationally fixed with respect to the shaft (12; 112), wherein the periscope unit (20; 120) rotates about the longitudinal axis (14; 114) is rotated relative to the shaft (12; 112). Method according to claim 13, wherein the periscope unit (20; 120) is rotated such that one plane (52; 152) of the two beam paths (22, 24; 122, 124) passing through the periscope unit (20; 120) is aligned at least approximately horizontally.

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