Illuminating system of medical endoscope

Abstract

The invention relates to the endoscope technology, and discloses a lighting system of a medical endoscope. Comprising a white light source, a light guide rod, a first collimating lens, a second collimating lens, a first dichroscope, a first focusing lens, a second focusing lens, an optical filter, a first laser source, a first beam expanding lens, a third collimating lens, a second dichroscope, a second laser source, a second beam expanding lens and a fourth collimating lens. The first collimating lens, the second collimating lens, the third collimating lens, the fourth collimating lens, the first focusing lens, the second focusing lens, the first beam expanding lens and the second beam expanding lens are all spherical lenses. The invention further discloses a medical endoscope. The white light and the two different lasers are correspondingly transmitted and reflected respectively, so that the illumination system of the medical endoscope meeting the illumination of the white light and the two lasers can be prepared by using a spherical lens, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of endoscopes, and in particular to a lighting system for a medical endoscope and a medical endoscope. Background Art

[0002] Endoscopic technology plays a vital role in modern medicine, allowing doctors to examine and treat patients' internal organs without major surgery. The lighting system is an important part of the endoscopy system, providing the necessary lighting for the endoscope to ensure that doctors can clearly see the lesion area.

[0003] Traditional endoscope lighting systems are usually designed with aspheric glass lenses to reduce optical aberrations and improve imaging quality. However, the processing technology of aspheric lenses is complex, especially when using the molding process, the cost is relatively high. This limits the widespread application of endoscope lighting systems, especially in cost-sensitive medical environments. In addition, the lighting system of existing medical endoscopes is generally white light + single laser lighting, which is difficult to meet the dual fluorescence requirements that require dual laser lighting (the second fluorescence is generally used for non-invasive ureteral imaging to prevent damage to the ureter during surgery).

[0004] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present application is to provide a lighting system for a medical endoscope and a medical endoscope. By transmitting and reflecting white light and two different lasers respectively, the lighting system of the medical endoscope can meet the requirements of white light and two laser illumination, and at the same time, the lighting system can be prepared using a spherical lens to reduce manufacturing costs.

[0006] To achieve the above-mentioned purpose, the present application provides an illumination system for a medical endoscope, the illumination system comprising: a first collimating lens, a second collimating lens, a first dichroic mirror, a first focusing lens, a second focusing lens and a filter arranged in sequence from a white light source to a light guide rod, and a transmission surface of the first dichroic mirror is at an angle of 45° toward the second collimating lens, and a reflection surface of the first dichroic mirror is at an angle of 45° toward the first focusing lens; A first beam expander lens, a third collimator lens, and a second dichroic mirror are sequentially arranged between the first laser source and the reflective surface of the first dichroic mirror in a direction which is 45° with the reflective surface of the first dichroic mirror and is perpendicular to the direction from the white light source to the light guide rod; wherein the second dichroic mirror is parallel to the first dichroic mirror, and the reflective surface of the second dichroic mirror faces the first dichroic mirror, and the transmission surface of the second dichroic mirror faces the third collimator lens; In a direction perpendicular to the direction from the white light source to the light guide rod, a second beam expander lens and a fourth collimator lens are sequentially arranged between the second laser source and the reflector; wherein the reflector is parallel to the second dichroic mirror and faces the reflective surface of the second dichroic mirror; Among them, the first collimating lens, the second collimating lens, the third collimating lens, the fourth collimating lens, the first focusing lens, the second focusing lens, the first beam expanding lens and the second beam expanding lens are all spherical lenses; the laser wavelengths emitted by the first laser source and the second laser source are different.

[0007] To achieve the above objectives, the present application also provides a medical endoscope, including the lighting system of the medical endoscope as described above.

[0008] The lighting system and medical endoscope of the medical endoscope provided in the present application all use spherical lenses with relatively simple processing technology in the lenses of the lighting system, which greatly reduces the manufacturing cost of the lighting system; and the lighting system can not only provide white light illumination, but also provide two different laser illuminations, thereby meeting the dual fluorescence imaging requirements of the medical endoscope; at the same time, by reasonably arranging the lens position and angle and optimizing the distribution of the light field, the lighting system can provide a uniform light field; and even if a spherical lens is used, the lighting system can still achieve high optical transmission efficiency through precise optical design and adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of the architecture of a lighting system for a medical endoscope in one embodiment of the present application.

[0010] Description of reference numerals: 1. White light source; 2. First collimating lens; 3. Second collimating lens; 4. First dichroic mirror; 5. Second laser source; 6. Second beam expander lens; 7. Fourth collimating lens; 8. Reflector; 9. First laser source; 10. First beam expander lens; 11. Third collimating lens; 12. Second dichroic mirror; 13. First focusing lens; 14. Second focusing lens; 15. Filter; 16. Light guide rod.

[0011] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0012] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0013] In addition, if the descriptions of "first", "second", etc. are involved in this application, they are only used for descriptive purposes (such as for distinguishing the same or similar features), and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0014] Reference Figure 1 In one embodiment, a lighting system for a medical endoscope is provided, the lighting system comprising: a first collimating lens 2, a second collimating lens 3, a first dichroic mirror 4, a first focusing lens 13, a second focusing lens 14 and a filter 15 arranged in sequence from a white light source 1 to a light guide rod 16, and a transmission surface of the first dichroic mirror 4 is at an angle of 45° toward the second collimating lens 3, and a reflection surface of the first dichroic mirror 4 is at an angle of 45° toward the first focusing lens 13; In a direction which is 45° with respect to the reflection surface of the first dichroic mirror 4 and is perpendicular to the direction from the white light source 1 to the light guide rod 16, a first beam expander lens 10, a third collimating lens 11 and a second dichroic mirror 12 are sequentially arranged from the first laser source 9 to the reflection surface of the first dichroic mirror 4; wherein the second dichroic mirror 12 is parallel to the first dichroic mirror 4, and the reflection surface of the second dichroic mirror 12 faces the first dichroic mirror 4, and the transmission surface of the second dichroic mirror 12 faces the third collimating lens 11; In a direction perpendicular to the direction from the white light source 1 to the light guide rod 16, a second beam expander lens 6 and a fourth collimator lens 7 are sequentially arranged between the second laser source 5 and the reflector 8; wherein the reflector 8 is parallel to the second dichroic mirror 12 and faces the reflective surface of the second dichroic mirror 12; Among them, the first collimating lens 2, the second collimating lens 3, the third collimating lens 11, the fourth collimating lens 7, the first focusing lens 13, the second focusing lens 14, the first beam expanding lens 10 and the second beam expanding lens 6 are all spherical lenses; the laser wavelengths emitted by the first laser source 9 and the second laser source 5 are different.

[0015] In this embodiment, the white light source 1 is used to provide white light and emit the white light to the first collimating lens 2. The white light source 1 can be a 400-700nm white light LED, that is, the white light can be a visible light of 400-700nm.

[0016] The first collimating lens 2 is a lens with positive optical power, and is used to converge the white light emitted by the white light source 1 to the second collimating lens 3 .

[0017] The second collimating lens 3 is a lens with positive optical power, and is used to further converge the white light converged by the first collimating lens 2 and make it incident on the transmission surface of the first dichroic mirror 4 at an angle of 45°.

[0018] Optionally, the main body of the first dichroic mirror 4 is flat glass with an optical focal length of 0; wherein one side of the transmission surface of the first dichroic mirror 4 is coated with a transmission film for transmitting white light; and one side of the reflection surface of the first dichroic mirror 4 is coated with a reflection film for reflecting laser.

[0019] The transmission surface of the first dichroic mirror 4 is used to transmit the white light further converged by the second collimating lens 3 to the first focusing lens 13 .

[0020] The first laser source 9 is used to provide laser light and emit the laser light to the first beam expansion lens 10. The first laser source 9 can be a 660nm semiconductor laser, that is, the laser light can be a 660nm near-infrared laser light.

[0021] The first beam expansion lens 10 is a lens with negative optical power, and is used to perform divergent beam expansion and homogenization processing on the laser emitted by the first laser source 9 , and scatter the processed laser to the third collimating lens 11 .

[0022] The third collimating lens 11 is a lens with positive refractive power, and is used to converge the diffused laser light into collimated parallel laser light, and make the parallel laser light incident on the transmission surface of the second dichroic mirror 12 at an angle of 45°.

[0023] The second dichroic mirror 12 is a flat glass body with an optical focal length of 0. A transmission film is coated on one side of the transmission surface of the second dichroic mirror 12 for transmitting the laser light emitted by the first laser source 9. A reflection film is coated on one side of the reflection surface of the second dichroic mirror 12 for reflecting the laser light emitted by the second laser source 5. The transmission surface of the second dichroic mirror 12 is used to transmit the laser light straightened by the third collimating lens 11 to the reflection surface of the first dichroic mirror 4.

[0024] The second laser source 5 is used to provide laser light and emit the laser light to the second beam expander lens 6. The second laser source 5 and the first laser source 9 emit laser light of different wavelengths; the second laser source 5 can be a 785nm semiconductor laser, that is, the laser light can be a 785nm near-infrared laser.

[0025] The second beam expander lens 6 is the same lens as the first beam expander lens 10 , and is used to perform divergent beam expansion and homogenization processing on the laser emitted by the second laser source 5 , and scatter the processed laser to the fourth collimating lens 7 .

[0026] The fourth collimating lens 7 is the same lens as the third collimating lens 11 , and is used to converge the diffused laser light into collimated parallel laser light and make the parallel laser light incident on the reflecting mirror 8 at an angle of 45°.

[0027] The reflector 8 is used to reflect the laser light straightened by the fourth collimating lens 7 at an angle of 90° to the reflective surface of the second dichroic mirror 12 , and then reflect the laser light at an angle of 90° to the reflective surface of the first dichroic mirror 4 through the reflective surface of the second dichroic mirror 12 .

[0028] The reflective surface of the first dichroic mirror 4 is used to reflect the laser light reflected and transmitted by the second dichroic mirror 12 to the first focusing lens 13 at an angle of 90°.

[0029] The first focusing lens 13 is a lens with positive optical power, and is used to focus the incident white light and laser light onto the second focusing lens 14 .

[0030] The second focusing lens 14 is a lens with positive optical power, and is used to further focus the incident white light and laser. A filter 15 is also provided between the second focusing lens 14 and the light focusing point of the second focusing lens 14 .

[0031] The filter 15 is used to selectively filter the light focused by the second focusing lens 14. For white light, the filter 15 is used to transmit white light and cut off laser light; for white light, the filter 15 is used to transmit laser light and cut off white light. Two types of filters 15 can be set, one of which is used to transmit white light and cut off laser light (such as transmitting 400-650nm white light and cutting off 650-800nm ​​laser light), and the other filter 15 is used to transmit laser light and cut off white light (such as cutting off 400-650nm white light and transmitting 650-800nm ​​laser light). The two filters 15 can be switched back and forth according to specific filtering requirements using a motor drive.

[0032] The light guide rod 16 has an optical focal length of 0 and is disposed at the light focusing point of the second focusing lens 14. Firstly, it is used to stagger the light guide beam and the light focusing point to avoid the high temperature generated by focusing from burning and damaging the light guide beam; secondly, it can play the role of uniform light.

[0033] Optionally, when the lighting system adopts white light illumination, the white light emitted by the white light source 1 passes through the first collimating lens 2, the second collimating lens 3, the first dichroic mirror 4, the first focusing lens 13, the second focusing lens 14, and the filter 15 in sequence, and is finally coupled into the light guide rod 16. The guide light beam is connected to the light emitting end face of the light guide rod 16, and the light can be coupled into the guide light beam.

[0034] Since the divergence angle of the white light source 1 is generally large (up to 120°), the white light must be collimated first to reduce the divergence angle and the spot size, so that the light can be coupled into the light guide. The first collimating lens 2 and the second collimating lens 3 form a white light collimating lens group, which mainly collimates the large-angle white light into parallel light. The white light collimating lens group is designed with spherical glass lenses, and can adopt traditional optical cold processing technology, with relatively low cost.

[0035] The collimated parallel light of the white light is split by the first dichroic mirror 4. The function of the first dichroic mirror 4 is to transmit the white light and reflect the laser (it can transmit the white light of 400-650nm and reflect the laser of 650-800nm). Therefore, when the white light passes through the transmission surface of the first dichroic mirror 4, it can reach the first focusing lens 13 through the transmission surface. Because the first dichroic mirror 4 is a flat plate and does not provide optical focal length, it will not change the propagation direction of the light, and the white light is still collimated light after passing through the first dichroic mirror 4.

[0036] The first focusing lens 13 and the second focusing lens 14 form a focusing lens group, and the main function is to focus the collimated light passing through the first dichroic mirror 4 and couple it into the light guide rod 16. What needs to be considered here is that the light guide has an NA value and a light aperture. Therefore, the image-side NA of the light converged by the focusing lens group must be less than or equal to the NA value of the light guide, and the focused light spot is less than or equal to the light aperture of the light guide, so that the light can be coupled into the light guide to the maximum extent, which can reduce the loss of light energy. And the focusing lens groups are all designed with spherical glass lenses, and traditional optical cold processing technology can be used, and the cost is relatively low. There is a filter 15 between the focusing lens group and the light guide rod 16. At this time, the filter 15 is switched to allow white light to pass through and cut off the laser.

[0037] After the white light passes through the focusing lens group and the filter 15, it can be coupled into the light guide rod 16 at a certain angle and spot size. Since the energy and temperature at the focus are very high, if the light-entering end face of the light guide beam is directly placed at the focus of the light, the extremely high temperature may burn the light guide beam, so a light guide rod 16 must be added at the focus, and the light guide beam can be placed on the light-emitting surface of the light guide rod 16, thereby avoiding the focus, protecting the light guide beam, and extending the service life of the light guide beam. Moreover, the light is totally reflected inside the light guide rod 16, which can achieve a certain uniform light effect. Therefore, the material of the light guide rod 16 can be an optical glass material that is resistant to high temperatures and has good light transmittance.

[0038] In this way, the entire white light optical path is a straight-through coaxial optical system, and the propagation path of the light is all through. The fully through optical system can minimize the loss of light energy and improve the optical transmission coupling efficiency of white light.

[0039] Optionally, when the illumination system is illuminated by the first laser source 9, the near-infrared laser (marked as the first laser) emitted by the first laser source 9 passes through the transmission surface of the first beam expander lens 10, the third collimator lens 11, and the second dichroic mirror 12 in sequence, and is reflected at 90° on the reflection surface of the first dichroic mirror 4 to enter the focusing lens group, and after being focused, passes through the filter 15 and is coupled into the light guide rod 16. The light guide is connected to the light emitting end surface of the light guide rod 16, and the light can be coupled into the light guide.

[0040] Since the divergence angle of the first laser is relatively small and it is a Gaussian beam distribution, the energy is basically concentrated in a small angle range. Therefore, the first laser must first be subjected to divergent beam expansion and homogenization processing. The first beam expansion lens 10 can expand the divergence angle of the first laser and make the light field distribution of the first laser uniform. And the first beam expansion lens 10 is designed as a spherical glass lens, and the traditional optical cold processing technology can be used, and the cost is relatively low. After the first laser is divergent and expanded, it still needs to be collimated so that the light can be coupled into the focusing lens group. The third collimating lens 11 can collimate the divergent light into parallel light, and the size of the collimated light spot is consistent with that of white light, which is more conducive to focusing and coupling into the light guide rod 16. And the third collimating lens 11 is designed as a spherical glass lens, and the traditional optical cold processing technology can be used, and the cost is relatively low.

[0041] The first laser is shaped into collimated parallel light by the third collimating lens 11, and then transmitted to the reflection surface of the first dichroic mirror 4 through the transmission surface of the second dichroic mirror 12; wherein the second dichroic mirror 12 is used to transmit the laser emitted by the first laser source 9 and reflect the laser emitted by the second laser source 5 (such as transmitting 660nm laser and reflecting 785nm laser). The first laser transmitted through the transmission surface of the second dichroic mirror 12 will be reflected on the reflection surface of the first dichroic mirror 4, and the angle between the reflection surface of the first dichroic mirror 4 and the incident angle of the first laser is 45°. The first dichroic mirror 4 can reflect the first laser into the focusing lens group. Like white light, the first laser is converged by the focusing lens group and passes through the filter 15 (at this time, the filter 15 is switched to be able to transmit laser light and cut off near-white light), and finally coupled into the light guide rod 16 at a certain angle and spot size. Connect the light guide beam to the light-emitting end face of the light guide rod 16, and the light can be coupled into the light guide beam.

[0042] Optionally, when the illumination system uses the second laser source 5 for illumination, the second laser source 5 emits a near-infrared laser (marked as the second laser), which passes through the second beam expander lens 6 and the fourth collimator lens 7 in sequence, and then enters the reflector 8 at an angle of 45°. The reflector 8 reflects the second laser at 90° to the reflective surface of the second dichroic mirror 12, and then the reflective surface of the second dichroic mirror 12 reflects the second laser at 90° to the reflective surface of the first dichroic mirror 4, and then reflects the second laser at 90° on the reflective surface of the first dichroic mirror 4 to enter the focusing lens group, and after focusing, passes through the filter 15 and is coupled into the light guide rod 16. The light guide beam is connected to the light emitting end face of the light guide rod 16, and the light can be coupled into the light guide beam.

[0043] Since the divergence angle of the second laser is relatively small and it is a Gaussian beam distribution, the energy is basically concentrated in a small angle range. Therefore, the second laser must first be subjected to divergent beam expansion and homogenization processing. The second beam expansion lens 6 can expand the divergence angle of the second laser and make the light field distribution of the laser uniform. And the second beam expansion lens 6 is designed as a spherical glass lens, and the traditional optical cold processing technology can be used, and the cost is relatively low. After the second laser is divergent and expanded, it still needs to be collimated so that the subsequent light can be coupled into the focusing lens group. The fourth collimating lens 7 can collimate the divergent light into parallel light, and the size of the collimated light spot is consistent with that of white light, which is more conducive to the subsequent focusing coupling of the laser into the light guide rod 16. And the fourth collimating lens 7 is designed as a spherical glass lens, and the traditional optical cold processing technology can be used, and the cost is relatively low.

[0044] The second laser is shaped into collimated parallel light by the fourth collimating lens 7, and then reflected by the reflector 8 to the reflection surface of the second dichroic mirror 12. The reflection surface of the second dichroic mirror 12 reflects the second laser to the reflection surface of the first dichroic mirror 4, and the angle between the reflection surface of the first dichroic mirror 4 and the incident second laser is 45°. The first dichroic mirror 4 can reflect the second laser into the focusing lens group. Like the first laser, the second laser is converged by the focusing lens group, passes through the filter 15, and finally couples into the light guide rod 16 at a certain angle and spot size. The light guide is connected to the light emitting end face of the light guide rod 16, and the light can be coupled into the light guide.

[0045] In fact, the second laser optical path is an off-axis three-mirror optical system. The reflector 8 and two dichroic mirrors are arranged in parallel in space, and the layout is relatively reasonable. The entire system is compactly arranged, which can reduce the overall size of the optical system. While meeting the transmission requirements of the second laser optical path, the overall size of the illumination system can be compressed.

[0046] In this way, white light and two types of lasers are integrated into one lighting system through clever spatial layout. Finally, the light of the three light paths can be emitted from the light guide rod 16 and the light guide beam, realizing a white light & laser three-light path composite lighting system. At the same time, the overall size of the lighting system can be made relatively small, forming a compact layout structure with high space utilization.

[0047] Among them, the first collimating lens 2, the second collimating lens 3, the third collimating lens 11, the fourth collimating lens 7, the first focusing lens 13, the second focusing lens 14, the first beam expanding lens 10 and the second beam expanding lens 6 are all designed with spherical lenses (such as spherical glass lenses), and the lens processing methods are all traditional optical cold processing processes, and the cost is much lower than the aspheric glass molding process. Moreover, the lens material can be made of glass material, and the material availability is very good. The second beam expanding lens 6 is the same as the first beam expanding lens 10 and can be shared; the third collimating lens 11 and the fourth collimating lens 7 are the same and can be shared, which greatly saves costs; the entire lighting system only needs to open six sets of cold processing molds, and the cost is relatively low. While achieving low cost, the lighting system can also achieve extremely high optical transmission efficiency and excellent light field distribution uniformity.

[0048] In one embodiment, the lenses in the lighting system are all spherical lenses with relatively simple processing technology, which greatly reduces the manufacturing cost of the lighting system; and the lighting system can not only provide white light illumination, but also provide two different laser illuminations, thereby meeting the dual fluorescence imaging requirements of medical endoscopes; at the same time, by reasonably arranging the lens position and angle and optimizing the distribution of the light field, the lighting system can provide a uniform light field; and even if a spherical lens is used, the lighting system can still achieve high optical transmission efficiency through precise optical design and adjustment.

[0049] Since the lighting system has good optical properties such as uniform light field and high optical transmission efficiency, it can improve image quality and reduce spot effect while meeting the requirements of low cost and dual fluorescence imaging in the application of medical endoscopes, and meet the requirements of high brightness and high lighting uniformity of medical endoscopes.

[0050] In one embodiment, based on the above embodiment, the first collimating lens 2 is a meniscus lens, and the concave surface faces the white light source 1 and the convex surface faces the second collimating lens 3 .

[0051] In this embodiment, the first collimating lens 2 is a meniscus lens having positive optical power.

[0052] Optionally, the center thickness of the first collimating lens 2 is 13.9 mm, the radius of curvature of the concave surface is R32.2 mm, the radius of curvature of the convex surface is R18.2 mm, and the diameter is Ø35 mm.

[0053] Since it is necessary to receive as much large-angle light coupled to the white light source 1 as possible, the concave surface needs to be close to the side of the white light source 1 and the convex surface needs to be away from the side of the white light source 1. In the white light collimating lens group, the first collimating lens 2 needs to bear most of the optical focal length to converge the large-angle light of the white light. Therefore, a high-refractive-index optical glass material, heavy lanthanum flint glass H-ZLAF92, can be selected, so that the curvature of the lens can be designed to be smaller, which is convenient for processing and production. Both optical surfaces of the lens are spherical designs, and traditional optical cold processing technology can be used, which is relatively low in cost.

[0054] Both optical surfaces can be coated with AR coating (anti-reflective coating) with a reflectivity of <0.5%.

[0055] In one embodiment, based on the above embodiment, the second collimating lens 3 is a plano-convex lens, with a flat surface facing the first collimating lens 2 and a convex surface facing the transmission surface of the first dichroic mirror 4 .

[0056] In this embodiment, the second collimating lens 3 is a plano-convex lens with positive optical power.

[0057] Optionally, the center thickness of the second collimating lens 3 is 10 mm, the convex surface curvature radius is R33.3 mm, and the diameter is Ø43 mm.

[0058] The second collimating lens 3 can shape the white light passing through the first collimating lens 2 into collimated parallel light. Since the first collimating lens 2 has already assumed most of the optical focal length, the optical focal length of the second collimating lens 3 can be relatively small, so that the optical glass material H-K9L with low refractive index and high transmittance can be selected. In order to save production and processing costs, it can be designed as a plano-convex lens with positive optical focal length, the plane of the plano-convex lens is close to the side of the first collimating lens 2, and the convex surface is away from the side of the first collimating lens 2. And the convex surface is designed to be a spherical surface, using traditional optical cold processing technology, and the cost is relatively low.

[0059] Both optical surfaces can be AR coated with a reflectivity of <0.5%.

[0060] Optionally, the white light collimating lens group composed of the first collimating lens 2 and the second collimating lens 3 needs to minimize the diameter of the collimated light spot so that the angle of the edge light after focusing will be smaller, so that the light can be more easily coupled into the light guide rod 16. Therefore, the collimated light spot diameter can be designed to be less than Ø38mm.

[0061] In one embodiment, based on the above embodiment, the first beam expander lens 10 is a plano-concave lens, with the flat surface facing the first laser source 9 and the concave surface facing the third collimating lens 11 .

[0062] In this embodiment, the first beam expander lens 10 is a plano-concave lens having a negative optical power.

[0063] Optionally, the center thickness of the first beam expander lens 10 is 6 mm, the radius of curvature of the concave surface is R17.272 mm, and the diameter is Ø24 mm.

[0064] In order to save costs, the first beam expander lens 10 can be designed as a plano-concave lens, with the plane of the lens close to the first laser source 9 and the concave surface away from the first laser source 9, mainly because the concave surface has the effect of diverging, expanding and homogenizing light.

[0065] In order to save costs and improve light transmittance, the first beam expander lens 10 can be made of high-transmittance optical glass material H-K9L. After the laser light passes through the concave surface of the first beam expander lens 10, the exit angle should be designed to be as large as possible. The concave surface can be designed as a spherical surface, using traditional optical cold processing technology, and the cost is relatively low.

[0066] The two optical surfaces can be coated with AR film with a reflectivity of <0.5%.

[0067] In one embodiment, based on the above embodiment, the second beam expander lens 6 is a plano-concave lens, with the flat surface facing the second laser source 5 and the concave surface facing the fourth collimating lens 7 .

[0068] In this embodiment, the second beam expander lens 6 can be manufactured using the same process as the first beam expander lens 10 .

[0069] The plane of the second beam expander lens 6 is close to the second laser source 5 , and the concave surface is far away from the second laser source 5 . The concave surface mainly plays the role of diverging, expanding and homogenizing light.

[0070] In one embodiment, based on the above embodiment, the third collimating lens 11 is a meniscus lens, and the concave surface faces the first beam expander lens 10 , and the convex surface faces the transmission surface of the second dichroic mirror 12 .

[0071] In this embodiment, the third collimating lens 11 is a meniscus lens with positive power.

[0072] Optionally, the third collimating lens 11 has a central thickness of 14.8 mm, a concave curvature radius of R30 mm, a convex curvature radius of R18.161 mm, and a diameter of Ø35 mm.

[0073] The concave surface of the third collimating lens 11 is close to the first beam expander lens 10, and the convex surface is far away from the first beam expander lens 10. This is because the concave surface of the third collimating lens 11 can diverge the laser again, and finally converge it into collimated parallel light through the convex surface. The third collimating lens 11 has a medium focal length, and the optical glass material H-ZF2 can be selected, which is relatively cheap. Both optical surfaces are spherical designs, and traditional optical cold processing technology can be used, and the cost is relatively low.

[0074] Both optical surfaces can be AR coated with a reflectivity of <0.5%.

[0075] In one embodiment, based on the above embodiment, the fourth collimating lens 7 is a meniscus lens, and the concave surface faces the second beam expander lens 6 and the convex surface faces the reflector 8 .

[0076] In this embodiment, the fourth collimating lens 7 can be manufactured using the same process as the third collimating lens 11 .

[0077] The concave surface of the fourth collimating lens 7 is close to the second beam expanding lens 6, and the convex surface is away from the second beam expanding lens 6. This is because the concave surface of the fourth collimating lens 7 can diverge and homogenize the laser light again, and finally converge it into collimated parallel light through the convex surface.

[0078] In one embodiment, based on the above embodiment, the first focusing lens 13 is a plano-convex lens, with a flat surface facing the second focusing lens 14 and a convex surface facing the reflection surface of the first dichroic mirror 4 .

[0079] In this embodiment, the first focusing lens 13 is a plano-convex lens with positive optical power.

[0080] Optionally, the center thickness of the first focusing lens 13 is 8.5 mm, the convex surface curvature radius is R42.4 mm, and the diameter is Ø43 mm.

[0081] According to the symmetry of the optical system, the focal length of the first focusing lens 13 should be close to that of the second collimating lens 3. Therefore, the first focusing lens 13 can also be designed as a plano-convex lens with positive focal length, with the convex surface of the lens close to the side of the first dichroic mirror 4 and the plane away from the side of the first dichroic mirror 4. The focal length that the first focusing lens 13 needs to bear is relatively small, and an optical glass material H-K9L with low refractive index and high transmittance can be selected, and the convex surface is designed to be a spherical surface, and the traditional optical cold processing process is adopted, and the cost is relatively low.

[0082] Both optical surfaces can be AR coated with a reflectivity of <0.5%.

[0083] In one embodiment, based on the above embodiment, the second focusing lens 14 is a meniscus lens, and the concave surface faces the filter 15 and the convex surface faces the first focusing lens 13 .

[0084] In this embodiment, the second focusing lens 14 is a meniscus lens with positive optical power.

[0085] Optionally, the center thickness of the second focusing lens 14 is 8 mm, the radius of curvature of the concave surface is R35.1 mm, the radius of curvature of the convex surface is R22.1 mm, and the diameter is Ø35 mm.

[0086] According to the symmetry of the optical system, the focal length of the second focusing lens 14 should be close to that of the first collimating lens 2. Because the light spot needs to be converged, the focal length that the second focusing lens 14 needs to bear is also relatively large. Similarly, the second focusing lens 14 can be designed as a meniscus lens with positive focal length, with the convex surface of the lens close to the side of the first focusing lens 13, and the concave surface of the lens away from the side of the first focusing lens 13. The second focusing lens 14 needs to bear most of the focal length in order to converge and couple the light into the light guide rod 16. Therefore, a high refractive index optical glass material, heavy lanthanum flint glass H-ZLAF92, can be selected, so that the curvature of the lens can be designed to be smaller, which is convenient for processing and production, and the two optical surfaces of the lens are designed to be spherical, using traditional optical cold processing technology, and the cost is relatively low.

[0087] Both optical surfaces can be AR coated with a reflectivity of <0.5%.

[0088] The focusing lens group composed of the first focusing lens 13 and the second focusing lens 14 and the white light collimating lens group are relatively symmetrical optical system structures. Such an optical structure is more conducive to coupling light into the light guide rod 16. It should be noted that the focal length of the focusing lens group is smaller than that of the white light collimating lens group, so that the focusing spot size and the edge light angle can better match the numerical aperture NA and the clear aperture of the light guide. Taking a light guide with a numerical aperture NA=0.57 and a diameter of Ø5mm as an example, the numerical aperture NA of the focusing spot should be less than or equal to 0.57, that is, the maximum angle of the light should be less than or equal to 69.5° and the diameter ≤Ø5mm, so that the optical transmission coupling efficiency of the light guide can be maximized.

[0089] In one embodiment, based on the above embodiment, taking the white light source 1 as a 400-700nm white light LED, the first laser source 9 as a 660nm semiconductor laser, and the second laser source 5 as a 785nm semiconductor laser as an example: Optionally, the transmission surface of the first dichroic mirror 4 is coated with a 400~650nm white light transmission film, and the reflection surface of the first dichroic mirror 4 is coated with a 650~800nm ​​infrared laser reflection film; the first dichroic mirror 4 is flat glass with an optical focal length of 0, an optional thickness of 1.1mm, and a material of H-K9L.

[0090] Optionally, the first dichroic mirror 4 can achieve transmission of 400-650nm white light and reflection of 650-800nm ​​laser (i.e., near-infrared laser) through multi-layer optical coating. The process is optical vacuum evaporation coating, and the substrate can be ordinary optical glass. In order to save costs and improve light transmittance, high-transmittance optical glass material H-K9L can be selected. With double-sided coating (such as AR coating on the transmission surface and dichroic coating on the reflection surface), the white light transmittance of 400-650nm can reach more than 96%, and the near-infrared laser reflectivity of 650-800nm ​​can reach more than 98%. In this way, the loss of light energy is relatively small.

[0091] Optionally, the transmission surface of the second dichroic mirror 12 is coated with a 660nm infrared laser transmission film, and the reflection surface of the second dichroic mirror 12 is coated with a 785nm infrared laser reflection film; the second dichroic mirror 12 is flat glass with an optical focal length of 0, an optional thickness of 1.1mm, and a material of H-K9L.

[0092] Optionally, the second dichroic mirror 12 can achieve transmission of 660nm white light and reflection of 785nm laser (i.e., near-infrared laser) through multi-layer optical coating. The process is optical vacuum evaporation coating, and the substrate can be ordinary optical glass. In order to save costs and improve light transmittance, high-transmittance optical glass material H-K9L can be selected. With double-sided coating (such as AR film coating on the transmission surface, such as 660nm laser anti-reflection; dichroic film coating on the reflection surface), the transmittance of 660nm laser can reach more than 96%, and the reflectivity of 785nm near-infrared laser can reach more than 98%. In this way, the loss of light energy is relatively small.

[0093] Optionally, the reflector 8 can be used to reflect 785 nm laser light, and can be replaced by a second dichroic mirror 12 (ie, a reflective surface of the second dichroic mirror 12 is used to replace the reflector 8) to simplify the complexity of preparing the illumination system.

[0094] In one embodiment, based on the above embodiment, the filter 15 can be prepared by optical vacuum evaporation coating technology, and the substrate can be ordinary optical glass. In order to save costs and improve light transmittance, a high-transmittance optical glass material H-K9L can be selected.

[0095] In one embodiment, based on the above embodiment, the light guide rod 16 may be a glass cylinder.

[0096] Optionally, the optical focal length of the light guide rod 16 is 0, the thickness is 10 mm, the diameter is Ø5 mm, and the material is H-K9L.

[0097] Optionally, the diameter of the light guide rod 16 should be consistent with the light aperture of the light guide beam, such as Ø5 mm, so that the coupling efficiency between the light guide beam and the optical system can be maximized.

[0098] The light guide rod 16 can be made of ordinary optical glass. In order to save costs and improve light transmittance, a high-transmittance optical glass material H-K9L can be selected.

[0099] Since the light needs to be totally reflected on the inner side of the cylindrical surface of the light guide rod 16, both the two planes and one cylindrical surface need to be cold processed and polished, with a surface quality of 60-40.

[0100] Since the cylindrical surface of the light guide rod 16 needs to be coated with UV glue during installation, the refractive index of the glue will destroy the total reflection condition of the light, so the cylindrical surface needs to be coated with a metal reflective film, which can be prepared by chemical plating with a reflectivity of >92%. Both optical planes (end faces) can be coated with AR film, which is prepared by optical vacuum evaporation coating technology with a reflectivity of <0.5%.

[0101] In addition, the present application further proposes a medical endoscope, which includes the lighting system of the medical endoscope described in the above-mentioned embodiments. The specific structure of the lighting system refers to the above-mentioned embodiments. Since the medical endoscope adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the technical effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0102] In summary, for the lighting system of the medical endoscope and the medical endoscope provided in the embodiments of the present application, the lenses in the lighting system all adopt spherical lenses with relatively simple processing technology, which greatly reduces the manufacturing cost of the lighting system; and the lighting system can not only provide white light illumination, but also provide two different laser illuminations, thereby meeting the dual fluorescence imaging requirements of the medical endoscope; at the same time, by reasonably arranging the lens position and angle and optimizing the distribution of the light field, the lighting system can provide a uniform light field; and even if a spherical lens is used, the lighting system can still achieve high optical transmission efficiency through precise optical design and adjustment.

[0103] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0104] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A lighting system for a medical endoscope, characterized in that: The lighting system comprises: a first collimating lens, a second collimating lens, a first dichroic mirror, a first focusing lens, a second focusing lens and a filter arranged in sequence from the white light source to the light guide rod, wherein the transmission surface of the first dichroic mirror faces the second collimating lens at an angle of 45°, and the reflection surface of the first dichroic mirror faces the first focusing lens at an angle of 45°; In a direction that is 45° with the reflection surface of the first dichroic mirror and is perpendicular to the direction from the white light source to the light guide rod, a first beam expander lens, a third collimator lens, and a second dichroic mirror are sequentially arranged between the first laser source and the reflection surface of the first dichroic mirror; wherein the second dichroic mirror is parallel to the first dichroic mirror, and the reflection surface of the second dichroic mirror faces the first dichroic mirror, and the transmission surface of the second dichroic mirror faces the third collimator lens; In a direction perpendicular to the direction from the white light source to the light guide rod, a second beam expander lens and a fourth collimator lens are sequentially arranged between the second laser source and the reflector; wherein the reflector is parallel to the second dichroic mirror and faces the reflective surface of the second dichroic mirror; Among them, the first collimating lens, the second collimating lens, the third collimating lens, the fourth collimating lens, the first focusing lens, the second focusing lens, the first beam expanding lens and the second beam expanding lens are all spherical lenses; the laser wavelengths emitted by the first laser source and the second laser source are different.

2. The lighting system for a medical endoscope according to claim 1, wherein: The first collimating lens is a meniscus lens, with a concave surface facing the white light source and a convex surface facing the second collimating lens.

3. The lighting system for a medical endoscope according to claim 1, wherein: The second collimating lens is a plano-convex lens, with a flat surface facing the first collimating lens and a convex surface facing the transmission surface of the first dichroic mirror.

4. The lighting system for a medical endoscope according to claim 1, wherein: The first beam expander lens is a plano-concave lens, with a flat surface facing the first laser source and a concave surface facing the third collimating lens.

5. The lighting system for a medical endoscope according to claim 1, wherein: The second beam expander lens is a plano-concave lens, with a flat surface facing the second laser source and a concave surface facing the fourth collimating lens.

6. The lighting system for a medical endoscope according to claim 1, wherein: The third collimating lens is a meniscus lens, with a concave surface facing the first beam expander lens and a convex surface facing the transmission surface of the second dichroic mirror.

7. The lighting system for a medical endoscope according to claim 1, wherein: The fourth collimating lens is a meniscus lens, with a concave surface facing the second beam expander lens and a convex surface facing the reflector.

8. The lighting system for a medical endoscope according to claim 1, wherein: The first focusing lens is a plano-convex lens, with a flat surface facing the second focusing lens and a convex surface facing the reflective surface of the first dichroic mirror.

9. The lighting system for a medical endoscope according to claim 1, wherein: The second focusing lens is a meniscus lens, with a concave surface facing the filter and a convex surface facing the first focusing lens.

10. A medical endoscope, characterized in that: A lighting system for a medical endoscope comprising any one of claims 1-9.

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