Multi-channel integrated endoscope system and multi-channel sensor module

Abstract

The invention provides a multi-channel integrated endoscope system and a multi-channel sensor module. The multi-channel integrated endoscope system comprises: an illumination module configured to emit illumination light to an object; an image module configured to acquire an image of the object; the multi-channel sensor module is configured to acquire spectral information of an object, the multi-channel sensor module comprises an imaging lens, a light homogenizer and a multi-channel array sensor, and the light homogenizer is arranged between the multi-channel array sensor and the imaging lens.

Description

Technical Field

[0001] The present invention relates to the technical field related to endoscopes, and in particular to a multi-channel integrated endoscope system and a multi-channel sensor module. Background Art

[0002] An endoscope is a medical tool that is used to enter the human body to observe lesions in organs or body cavities that may not be directly observed without surgery or biopsy.

[0003] With the continuous development of image processing technology, the original black and white cameras were replaced by color image capture devices, forming a color endoscope system, which is used to collect images of various parts of the body cavity, and then the lesions in various parts can be examined in detail through the captured images. Figure 1A As shown, a conventional color endoscope imaging system 100 includes an illumination module 101 and an imaging module 103 having an imaging lens and an image sensor, wherein an illumination field of view 101a and an imaging field of view 103a are respectively illustrated. The illumination module 101 provides a light source for illuminating biological tissue. When the biological tissue is irradiated with light, the light reflected from the surface of the biological tissue can be collected by the imaging lens and then imaged on the image sensor. Figure 1B The layout of the image sensor of the conventional color endoscope imaging system 100 is shown. The color image sensor uses three color filters, namely red, green, and blue (R, G, B) filters. Figure 1C As shown, they have different spectral transmittance characteristics across three wavelength bands. Figure 1A The color endoscopic imaging system shown shows good spatial resolution in imaging, but insufficient spectral information.

[0004] In order to improve the Figures 1A to 1C To solve the problem that the spectral information of the illuminated object obtained by the endoscope system is insufficient, a single-zone spectral sensor is integrated into the endoscope system. Figure 2A An endoscope system 200 with a single-zone spectral sensor is shown, which includes an illumination module 201, an imaging module 203, and a single-zone spectral sensor module 205, which respectively show a lighting field of view 201a and an imaging field of view 203a. Figure 2BThe single-zone spectral sensor module 205 includes a mechanical opening 205 - 1 , a light homogenizer (diffuser) 205 - 2 , and a multi-channel sensor (multispectral sensor) 205 - 3 having a plurality of channels. Figure 2C and Figure 2D The filter layout of a multi-channel sensor and the spectra of the channels are shown separately, such as blue (B), green (G), yellow (Y), red (R), and gray (g) channels. Usually, a diffuser is used as a homogenizer to increase the uniformity of the irradiance on the spectral sensor. The half-width (FWHM) of each channel spectrum, such as Figure 2D As shown, the white balance settings of the endoscope system 200 are usually calculated based on the response of the spectral sensor. FIG. 2A to FIG. 2D The design of the endoscope system shown allows for good spatial resolution in imaging, but only average spectral information of the captured scene can be obtained.

[0005] To further improve FIG. 2A to FIG. 2D The endoscope system shown has the capability of obtaining spectral information of the illuminated object, so it is proposed to integrate a multichannel array sensor into the endoscope system. FIG. 3A to FIG. 3E An endoscope system 300 is shown having a multi-channel array sensor. Figure 3A As shown, a multi-channel array sensor is used to replace the single-zone spectral sensor, which includes an illumination module 301, an imaging module 303 and a multi-channel sensor module 305, and illustrates an illumination field of view 301a, an imaging field of view 303a and a sensing field of view 305a respectively. FIG. 3A to FIG. 3E The multi-channel sensor module 305 shown includes an imaging lens 305-1, a light homogenizer 305-2, and a multi-channel array sensor 305-3. FIG. 3A to FIG. 3E The multi-channel array sensor 305-3 shown has a plurality of regions 30, each region having a plurality of channels, such as blue (B), green (G), yellow (Y), red (R), and gray (g) channels, and having gaps between adjacent regions for reducing crosstalk between adjacent sub-FOVs, where FOV stands for field of view. Figure 3D The half-width (FWHM) width of the spectrum for each channel shown is typically narrower than that of a conventional color image sensor. The diffuser acts as a homogenizer to increase the uniformity of irradiance across the region. However, this newer endoscope system design utilizes a diffuser bulk as a homogenizer. Figure 3E The irradiance on the multi-channel array sensor 305 - 3 shown will still be uneven due to the presence of the diffuser, resulting in relatively non-uniform irradiance and low transmittance, which in turn leads to poor uniformity in the outer region. Summary of the invention

[0006] The object of the present invention is to In order to achieve the above-mentioned purpose, according to one aspect of the present invention, the present invention proposes a multi-channel integrated endoscope system, including an illumination module, configured to emit illumination light to an object; an imaging module, configured to receive reflected light from the object to obtain an image of the object; and a multi-channel sensor module, configured to receive reflected light from the object to obtain spectral information of the object, the multi-channel sensor module comprising an imaging lens, a homogenizer and a multi-channel array sensor, wherein the homogenizer is disposed between the multi-channel array sensor and the imaging lens.

[0007] In some embodiments, the multi-channel sensor module includes a plurality of spectral sensing regions.

[0008] In some embodiments, each of the plurality of spectral sensing regions divides the sensing field of view of the object into sub-fields of view.

[0009] In some embodiments, each of the plurality of spectral sensing regions comprises a plurality of spectral filter channels, and each of the plurality of spectral sensing regions generates spectral information of the sub-field of view.

[0010] In some embodiments, the light homogenizer is a microlens array.

[0011] In some embodiments, the microlens array described above is composed of lenses having only one side in a spherical shape.

[0012] In some embodiments, the ratio of the microlens pitch to the sensing area pitch is between 0.45 and 1.

[0013] In some embodiments, the ratio of the microlens focal length to the sensing area pitch is between 2 and 8.

[0014] In some embodiments, the above-mentioned microlens array includes: a substrate; a plurality of first microlenses formed on one side of the substrate; and an aperture stop layer formed on the same side or the other side of the substrate, wherein the aperture stop layer includes a plurality of transparent areas.

[0015] In some embodiments, the aperture stop layer is formed of black photoresist to reduce crosstalk and stray light between the plurality of transparent regions.

[0016] According to another aspect of the present invention, the present invention provides a multi-channel sensor module, comprising: an imaging lens, configured to receive reflected light from an object; a homogenizer, configured to homogenize the reflected light of the object; and a multi-channel array sensor, configured to receive the reflected light of the object to obtain spectral information of the object, wherein the homogenizer is disposed between the multi-channel array sensor and the imaging lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The components, features and advantages of the present invention can be understood through the detailed description of the preferred embodiments outlined in this specification and the accompanying drawings: 〔 Figure 1A 〕 shows an exemplary endoscope system according to the prior art.

[0018] 〔 Figure 1B 〕and〔 Figure 1C 〕Display〔 Figure 1A 〕The image sensor filter layout and filter spectrum used in the endoscope system shown in FIG.

[0019] 〔 Figure 2A 〕 shows another exemplary endoscope system according to the prior art.

[0020] 〔 Figure 2B 〕Shown in〔 Figure 2A 〕A single-zone spectral sensor module for an endoscope system as shown.

[0021] 〔 Figure 2C 〕 and〔 Figure 2D 〕 respectively show〔 Figure 2B 〕The image sensor filter layout and filter spectrum used in the single-zone spectral sensor module shown.

[0022] 〔 Figure 3A 〕 shows another exemplary endoscope system according to the prior art.

[0023] 〔 Figure 3B 〕Shown as〔 Figure 3A 〕A multi-channel sensor module for an endoscope system as shown.

[0024] 〔 Figure 3C 〕 and〔 Figure 3D 〕are displayed as〔 Figure 3B 〕 shows the layout of the multi-channel array sensors and the spectrum of the color filters used in each area of ​​the multi-channel array sensor of the multi-channel sensor module.

[0025] 〔 Figure 3E 〕Shown in〔 Figure 3B 〕Irradiance at different area positions on the multi-channel array sensor of the multi-channel sensor module shown in FIG.

[0026] 〔 Figure 4A 〕shows a multi-channel integrated endoscope system according to an embodiment of the present invention.

[0027] 〔 Figure 4B 〕depicts a schematic diagram according to an embodiment of the present invention, which shows that the imaging lens can map a sub-field of view of an object (or region of interest) to a corresponding spectral sensing area on a sensor plane.

[0028] 〔 Figure 4C 〕shows the following according to one embodiment of the present invention: Figure 4A 〕A multi-channel sensor module for an endoscope system as shown.

[0029] 〔 Figure 4D 〕and〔 Figure 4E 〕 respectively show the following Figure 4C 〕The multi-channel array sensor layout and the spectrum of color filters used in each area of ​​the multi-channel array sensor of the multi-channel sensor module shown.

[0030] 〔 Figure 5A 〕 shows a cross-sectional view of a light homogenizer with a single-sided microlens array according to an embodiment of the present invention.

[0031] 〔 Figure 5B 〕 shows a cross-sectional view of a light homogenizer with a single-sided microlens array according to another embodiment of the present invention.

[0032] 〔 Figure 5C 〕shows a front view of a light homogenizer with a microlens array according to an embodiment of the present invention.

[0033] 〔 Figure 5D 〕 schematically shows the optical path of the imaging lens according to an embodiment of the present invention to project light onto the multi-channel array sensor.

[0034] 〔 Figure 6 〕shows the method according to one embodiment of the present invention Figure 4C 〕Irradiance at various regional locations on the multi-channel array sensor of the multi-channel sensor module shown in FIG.

[0035] 〔 Fig. 7A 〕and〔 Figure 7B 〕 respectively show the axial light path and off-axis light path of the microlens array of the light homogenizer according to an embodiment of the present invention.

[0036] In the figure: 100: endoscope imaging system; 101: illumination module; 103: imaging module; 200: endoscope system; 201: illumination module; 201a: illumination field of view; 203: imaging module; 203a: imaging field of view; 205: single-zone spectral sensor module; 205-1: mechanical opening; 205-2: homogenizer; 205-3: multi-channel sensor; 30: multiple regions; 300: endoscope system; 301: illumination module; 301a: illumination field of view; 303: imaging module; 303a: imaging field of view; 305: multi-channel sensor module; 305a: sensing field of view; 305-1: Imaging lens; 305-2: homogenizer; 305-3: multi-channel array sensor; 40a, 40b, 40c: multiple spectral sensing areas; 400: endoscope system; 401: illumination module; 401a: illumination field of view; 403: imaging module; 403a: imaging field of view; 405: multi-channel sensor module; 405a: sensing field of view; 405-1: image lens; 405-2: microlens array; 405-3: channel array sensor; 405-1a: exit pupil; 50a, 50b: microlens; 50-1: first microlens; 510: substrate; 512: aperture light barrier layer. DETAILED DESCRIPTION

[0037] Here, the present invention will be described in detail with respect to specific embodiments of the invention and their viewpoints. Such description is for explaining the structure or step flow of the present invention, which is for illustrative purposes rather than for limiting the scope of the present invention. Therefore, in addition to the specific embodiments and preferred embodiments in the specification, the present invention can also be widely implemented in other different embodiments. The following describes the implementation of the present invention by means of specific specific embodiments, and people familiar with this technology can easily understand the efficacy and advantages of the present invention through the contents disclosed in this specification. In addition, the present invention can also be used and implemented by means of other specific embodiments, and the various details described in this specification can also be applied based on different needs, and various modifications or changes can be made without departing from the spirit of the present invention.

[0038] To solve Figures 1A to 3E The problems encountered by conventional endoscope systems mentioned in the literature include insufficient spectral information, insufficient color information under mixed lighting conditions, and low penetration and poor uniformity due to the use of conventional diffusers (as homogenizers). Figure 4AThe present invention proposes a multi-channel integrated endoscope system 400, including an illumination module 401, an imaging module 403 and a multi-channel sensor module 405, and displays an illumination field 401a, an imaging field 403a and a sensing field 405a respectively. The illumination module 401 is configured to emit illumination light to an object. The imaging module 403 includes an imaging lens and an image sensor, and is configured to capture an image of an object. The multi-channel sensor module 405 is configured to obtain spectral information of an object through an imaging lens, a homogenizer and a multi-channel array sensor, which is described in detail below. Figure 4B A schematic diagram is depicted showing that sub-fields of view (sub-FOVs) of an object (or area of ​​interest) can be mapped to corresponding spectral sensing areas (40a, ...) on a sensor plane through an imaging lens 405-1, wherein each area is one of a plurality of spectral sensing regions of a multi-channel array sensor of a multi-channel sensor module 405.

[0039] According to an embodiment of the present invention, Figure 4C As shown, the multi-channel sensor module 405 is configured with an imaging lens 405-1, a microlens array (MLA) 405-2 as a light homogenizer, and a multi-channel array sensor 405-3 to sense the field of view (FOV) of an object.

[0040] According to an embodiment of the present invention, Figure 4D As shown, the multi-channel array sensor 405-3 includes a plurality of spectral sensing regions (40a, 40b, 40c, ...) configured as a spectral sensing array, and each spectral sensing region has a plurality of spectral filter channels, such as blue (B), green (G), yellow (Y), red (R) and gray (g), and each region divides the sensing field of view (sensing FOV) into a plurality of sub-fields of view (sub-FOVs), each sub-field of view corresponding to a specific spectral sensing region.

[0041] According to an embodiment of the present invention, there is a gap between adjacent spectral sensing regions to reduce crosstalk from adjacent sub-FOVs, where FOV stands for field of view. Figure 4E As shown, the width of the half-width maximum (FWHM) of each channel spectrum is generally narrower than that of a conventional color image sensor.

[0042] According to an embodiment of the present invention, the field of view of the imaging lens of the multi-channel sensor module at least covers the field of view of the imaging lens of the imaging module.

[0043] According to an embodiment of the present invention, the field of view of the imaging lens of the multi-channel sensor module is between 90 degrees and 120 degrees.

[0044] According to an embodiment of the present invention, the F-number (F-number), or relative aperture, of the imaging lens of the multi-channel sensor module is between 1.4 and 5.6.

[0045] In the present invention, a new homogenizer design is proposed to improve the uniformity of irradiance in each area of ​​a multi-channel array sensor. According to one embodiment of the present invention, Figure 5A A cross-sectional view of a light homogenizer 405-2 is shown, which includes a substrate 510, a plurality of micro lenses (50a, 50b, ...) are fabricated on one side of the substrate 510 to form a micro lens array, and an aperture stop layer 512 is formed on the other side of the substrate 510. In an alternative embodiment, as Figure 5B As shown, the light homogenizer 405-2 includes a substrate 510, a plurality of first micro lenses 50-1 manufactured on one side of the substrate 510, and an aperture stop layer 512 formed on the same side of the substrate 510. The aperture stop layer 512 includes a plurality of transparent regions to form an aperture array. Figure 5C A front view of the light homogenizer 405 - 2 is shown, wherein an aperture light barrier layer 512 is formed of black photoresist or other opaque material on either or both sides of the substrate to reduce crosstalk and stray light between transparent areas. Figure 5D The schematic diagram shows the optical path of the imaging lens 405-1 being projected onto the multi-channel array sensor 405-3. Each microlens forms an image of the imaging lens 405-1 through the exit pupil 405-1a on the sensor plane of the multi-channel array sensor 405-3. The exit pupil 405-1a is arranged between the imaging lens 405-1 and the microlens array of the homogenizer 405-2. The uniformity and crosstalk between adjacent areas of the multi-channel array sensor 405-3 are controlled by the aperture opening size of the aperture light barrier layer 512 and the distance between the imaging lens 405-1 and the microlens array.

[0046] According to an embodiment of the present invention, a microlens array is formed of lenses having a spherical shape on only one side.

[0047] Figure 6 show FIG. 5A to FIG. 5D The irradiance of each area position on the multi-channel array sensor of the multi-channel sensor module shown. Figure 6 The complete irradiance diagram of the multi-channel array sensor 405-3 is shown, and Figure 6 The lower left, upper right and lower right of the figure show the irradiance diagrams of the central area, corner area and edge area respectively. In the central area, the x curve and the y curve overlap, where the x(y) curve represents the irradiance distribution along the x(y) direction. Figure 6As a result, by utilizing a microlens array on a homogenizer, the transmittance and uniformity of irradiance at various regional locations can be greatly improved.

[0048] Fig. 7A and Figure 7B The axial light path and off-axial light path of the microlens array of the homogenizer 405-2 of the present invention are shown respectively. In both cases, the microlens array of the homogenizer 405-2 directly projects the images of the imaging lens 405-1 from different sub-scenes onto the corresponding areas of the multi-channel array sensor 405-3 without performing imaging processing. The spectral information of the sub-scene will be evenly distributed in the corresponding areas of the multi-channel array sensor 405-3 to produce irradiance with good uniformity.

[0049] According to an embodiment of the present invention, the microlens array of the light homogenizer 405-2 is placed at the focal plane of the imaging lens 405-1.

[0050] According to an embodiment of the present invention, the ratio of the microlens pitch d2 to the sensing region pitch d1 (pitch ratio), ie, d2 / d1 , is between 0.45 and 1.

[0051] According to an embodiment of the present invention, a maximum chief ray angle (CRA) of the imaging lens is equal to or less than 15 degrees.

[0052] According to an embodiment of the present invention, the ratio of the microlens focal length to the sensing area pitch is between 2 and 8.

[0053] In summary, the integrated multi-channel endoscope system proposed in the present invention utilizes a microlens array to replace a diffuser and, in conjunction with the use of an imaging lens, can directly map the irradiance distribution of a scene onto a multi-channel array sensor of the endoscope system, with the advantages of high fidelity and consistency.

[0054] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A multi-channel integrated endoscope system, characterized in that: include: an illumination module configured to emit illumination light toward the object; an imaging module configured to receive the reflected light of the object to obtain an image of the object; as well as A multi-channel sensor module is configured to receive the reflected light of the object to obtain spectral information of the object. The multi-channel sensor module includes an imaging lens, a homogenizer and a multi-channel array sensor, wherein the homogenizer is arranged between the multi-channel array sensor and the imaging lens.

2. The multi-channel integrated endoscope system according to claim 1, characterized in that: The multi-channel sensor module mentioned above includes a plurality of spectral sensing areas.

3. The multi-channel integrated endoscope system as claimed in claim 2, characterized in that: Each of the plurality of spectral sensing regions divides the sensing field of view of the object into sub-fields of view.

4. The multi-channel integrated endoscope system as claimed in claim 2, characterized in that: Each of the plurality of spectral sensing regions comprises a plurality of spectral filter channels, and each of the plurality of spectral sensing regions generates spectral information of the sub-field of view.

5. The multi-channel integrated endoscope system as claimed in claim 1, characterized in that: The above-mentioned light homogenizer is a microlens array.

6. The multi-channel integrated endoscope system as claimed in claim 5, characterized in that: The above-mentioned microlens array is composed of lenses having only one side in a spherical shape.

7. The multi-channel integrated endoscope system as claimed in claim 5, characterized in that: The ratio of the microlens pitch to the sensing area pitch is between 0.45 and 1.

8. The multi-channel integrated endoscope system as claimed in claim 5, characterized in that: The ratio of the microlens focal length to the sensing area pitch is between 2 and 8.

9. The multi-channel integrated endoscope system as claimed in claim 5, characterized in that: The above-mentioned microlens array comprises: a substrate; A plurality of first micro lenses formed on one side of the substrate; An aperture stop layer is formed on the same side or the other side of the substrate, wherein the aperture stop layer includes a plurality of transparent areas.

10. The multi-channel integrated endoscope system according to claim 9, characterized in that: The aperture light barrier layer is formed of black photoresist and is used to reduce crosstalk and stray light between the plurality of transparent areas.

11. A multi-channel sensor module, characterized in that: include: an imaging lens configured to receive reflected light from the object; a light homogenizer configured to homogenize the reflected light from the object; as well as A multi-channel array sensor is configured to receive the reflected light of the object to obtain spectrum information of the object, wherein the light homogenizer is disposed between the multi-channel array sensor and the imaging lens.

12. The multi-channel sensor module according to claim 11, wherein: The multi-channel array sensor mentioned above includes a plurality of spectral sensing regions.

13. The multi-channel sensor module according to claim 12, wherein: Each of the plurality of spectral sensing regions divides the sensing field of view of the object into sub-fields of view.

14. The multi-channel sensor module according to claim 13, wherein: Each of the plurality of spectral sensing regions comprises a plurality of multi-channel filter arrays, and each of the plurality of spectral sensing regions generates spectral information of the sub-field of view.

15. The multi-channel sensor module according to claim 14, wherein: Each of the plurality of multi-channel filter arrays contains a spectrum of a plurality of channels.

16. The multi-channel sensor module according to claim 11, wherein: The above-mentioned light homogenizer is a microlens array.

17. The multi-channel sensor module according to claim 11, wherein: The above-mentioned microlens array is composed of lenses having only one side in a spherical shape.

18. The multi-channel sensor module according to claim 16, wherein: The ratio of the microlens pitch to the sensing area pitch is between 0.45 and 1.

19. The multi-channel sensor module according to claim 16, wherein: The ratio of the microlens focal length to the sensing area pitch is between 2 and 8.

20. The multi-channel sensor module according to claim 16, wherein: The above-mentioned microlens array comprises: a substrate; A plurality of first micro lenses formed on one side of the substrate; An aperture stop layer is formed on the same side or the other side of the substrate, wherein the aperture stop layer includes a plurality of transparent areas.

21. The multi-channel sensor module according to claim 16, wherein: The aperture light barrier layer is formed of black photoresist and is used to reduce crosstalk and stray light between the plurality of transparent areas.

22. The multi-channel sensor module according to claim 20, wherein: The plurality of first micro lenses are formed on the aperture stop layer.

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