A dual lens capsule endoscope lens

Abstract

This invention relates to a dual-lens capsule endoscope lens, comprising two capsule endoscope lenses with different imaging functions: a lens with narrowband imaging characteristics and a high-definition ultra-wide-angle lens. The optical system of the first lens includes a first lens group, a first aperture, a second lens group, and a first protective glass. The first lens group includes a meniscus negative lens with negative optical power, a convex-concave negative lens with negative optical power, and a meniscus lens with positive optical power. The second lens group includes a biconvex lens with positive optical power and a biconcave lens with negative optical power. The optical system of the second lens includes a third lens group, a second aperture, a fourth lens group, and a second protective glass. The third lens group includes a convex-concave positive lens with positive optical power. The fourth lens group includes a cemented lens and a convex-concave lens with positive optical power. The cemented lens is formed by cementing a biconvex lens with positive optical power and a concave-convex lens with negative optical power, and also has positive optical power. This lens can expand the field of view coverage and improve detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of endoscope lenses, and more specifically to a dual-lens capsule endoscope lens. Background Technology

[0002] Capsule endoscopy, a type of electronic endoscopy, is smaller and capsule-shaped than traditional electronic endoscopes. It can enter the small intestine with the peristalsis of the digestive tract to take pictures and videos without causing trauma or irritation to the body. Narrow-band imaging (NBI) is an emerging endoscopic technique that uses filters to remove the broadband spectrum of red, blue, and green light emitted by the endoscope's light source, leaving only a narrow band spectrum for diagnosing various digestive tract diseases. The NBI system uses a narrow-band filter instead of a traditional broadband filter to limit different wavelengths of light, leaving only the 540nm and 415nm wavelengths of green and blue narrow-band light. The depth to which these narrow-band light waves penetrate the gastrointestinal mucosa varies; the blue band (415nm) penetrates shallower to visualize the submucosal vascular network, while the green band (540nm) better visualizes the vessels in the intermediate layer. Because the optical properties of blood within mucous membranes strongly absorb blue and green light, using light waves that are difficult to diffuse and can be absorbed by the blood can increase the contrast and clarity of the mucosal epithelium and submucosal blood vessels. Applying this technology to capsule endoscopy can make it easier to detect lesions during examinations and improve detection accuracy. Summary of the Invention

[0003] The purpose of this invention is to provide a dual-lens capsule endoscope lens that can expand the field of view and improve detection accuracy.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a dual-lens capsule endoscope lens, comprising two capsule endoscope lenses with different imaging functions, the first lens being a lens with narrowband imaging characteristics, and the second lens being an ultra-wide-angle lens with high definition; the optical system of the first lens is arranged sequentially from the object side to the image side as a first lens group, a first aperture, a second lens group, and a first protective glass; the first lens group includes a first lens, a second lens, and a third lens, the first lens being a meniscus negative lens with negative optical power, the second lens being a convex-concave negative lens with negative optical power, and the third lens being a meniscus lens with positive optical power; the second lens group includes a fourth lens and a fifth lens, the fourth lens being a biconvex lens with positive optical power, and the fifth lens being a biconcave lens with negative optical power.

[0005] The optical system of the second lens consists of a third lens group, a second aperture, a fourth lens group, and a second protective glass arranged sequentially from the object side to the image side. The third lens group includes a sixth lens, which is a convex-concave positive lens with positive optical power. The fourth lens group includes a cemented lens and a ninth lens. The cemented lens is formed by cementing a seventh lens and an eighth lens and has positive optical power. The seventh lens is a biconvex lens with positive optical power, the eighth lens is a concave-convex lens with negative optical power, and the ninth lens is a convex-concave lens with positive optical power.

[0006] Furthermore, the overall focal length of the optical system of the first lens is f, and the combined focal lengths of the first lens group and the second lens group are f1 and f2 respectively. a f b -1≤f a / f b ≤0; The focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are f1, f2, f3, f4, and f5, respectively, wherein f1, f2, f3, f4, and f5 satisfy the following ratios with f: 1≤|f1| / f≤3, 1≤|f2| / f≤3, 40≤|f3| / f≤50, 0≤|f4| / f≤1, 1≤|f5| / f≤3.

[0007] Furthermore, the first lens satisfies the relationship: 1.5 ≤ N d ≤1.7, 30.0≤V d ≤40.0; the second lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The third lens satisfies the relationship: 1.5≤N d ≤1.7, 20.0≤V d ≤30.0; The fourth lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The fifth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; where N d V is the refractive index. d Let be Abbe's constant.

[0008] Furthermore, the on-axis distances between the lenses in the first lens satisfy the following relationships: the air gap between the first lens and the second lens is 0.2–0.5 mm; the air gap between the second lens and the third lens is 0.3–0.6 mm; the air gap between the third lens and the first aperture is 0.05–0.1 mm; the air gap between the first aperture and the fourth lens is 0.03–0.1 mm; the air gap between the fourth lens and the fifth lens is 0.05–0.1 mm; and the air gap between the fifth lens and the first protective glass is 0.3–0.6 mm.

[0009] Furthermore, the total length of the optical system of the first lens is <3.9mm.

[0010] Furthermore, the overall focal length of the optical system of the second lens is f*, and the combined focal lengths of the third and fourth lens groups are f* respectively. a f* b -4≤f* a / f* b ≤-2; the focal lengths of the sixth lens, the cemented lens, and the ninth lens are f*1, f*, and f*, respectively. 2-3 f*4, where f*1 and f*4 are... 2-3 f*4 and f* satisfy the following ratios: 1≤|f*1| / f*≤3, 0≤|f* 2-3 | / f*≤1, 5≤|f*4| / f*≤6.

[0011] Furthermore, the sixth lens satisfies the relationship: 1.6 ≤ N d ≤1.8, 20.0≤V d ≤30.0; The seventh lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The eighth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; The ninth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; where N d V is the refractive index. d Let be Abbe's constant.

[0012] Furthermore, the on-axis distances between the lenses in the second lens satisfy the following relationships: the air gap between the sixth lens and the second aperture stop is 0.2 to 0.5 mm; the air gap between the second aperture stop and the cemented lens is 0.05 to 0.1 mm; the air gap between the cemented lens and the ninth lens is 0.2 to 0.5 mm; and the air gap between the ninth lens and the second protective glass is 0.4 to 0.7 mm.

[0013] Furthermore, the total length of the optical system of the second lens is <3.8mm.

[0014] Furthermore, the first lens is used to acquire images of the digestive tract mucosa, and the second lens is used to acquire images of the overall tissue structure and morphological information.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a dual-lens capsule endoscope lens, which integrates a lens with narrow-band imaging characteristics and a high-definition ultra-wide-angle lens in a capsule. The two lenses have different working distances, which can achieve clearer image quality at distances of 10mm and 20mm respectively; the two lenses have different wavelength ranges for imaging. The first lens is beneficial for enhancing the image of the digestive tract mucosa, while the second lens can provide overall tissue structure and morphological information, which helps to comprehensively assess the condition of lesions; the two lenses cover a large field of view, with the first lens having a field of view of 140° and the second lens having a field of view of 100°, which can cover a total field of view of 240°. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the optical structure of the first lens in an embodiment of the present invention;

[0017] Figure 2 This is the optical path diagram of the optical system of the first lens in this embodiment of the invention;

[0018] Figure 3 This is the MTF curve of the first lens in this embodiment of the invention at a wavelength of 415nm;

[0019] Figure 4 This is the MTF curve of the first lens in this embodiment of the invention at a wavelength of 540nm;

[0020] Figure 5 This is a dot plot of the first lens in this embodiment of the invention at a wavelength of 415nm;

[0021] Figure 6 This is a dot plot of the first lens in this embodiment of the invention at a wavelength of 540nm;

[0022] Figure 7This is the field curvature / distortion diagram of the first lens in this embodiment of the invention at a wavelength of 415nm;

[0023] Figure 8 This is the field curvature / distortion diagram of the first lens in this embodiment of the invention at a wavelength of 540nm;

[0024] Figure 9 This is the relative illumination diagram of the first lens in this embodiment of the invention;

[0025] Figure 10 This is a schematic diagram of the optical structure of the second lens in an embodiment of the present invention;

[0026] Figure 11 This is the optical path diagram of the second lens in this embodiment of the invention;

[0027] Figure 12 This is the MTF curve of the second lens in this embodiment of the invention;

[0028] Figure 13 This is a dot diagram of the second lens in an embodiment of the present invention;

[0029] Figure 14 This is the field curvature / distortion diagram of the second lens in this embodiment of the invention;

[0030] Figure 15 This is the relative illumination diagram of the second lens in this embodiment of the invention. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0033] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0034] This embodiment provides a dual-lens capsule endoscope, comprising two capsule endoscope lenses with different imaging functions. The first lens is a narrow-band imaging lens, providing good imaging under narrow-band wavelengths of 415nm and 540nm. The second lens is an ultra-wide-angle lens with higher resolution, providing good imaging under visible light. The first lens is used to acquire images of the digestive tract mucosa, and the second lens is used to acquire images of the overall tissue structure and morphology.

[0035] like Figure 1 As shown, the optical system of the first lens is arranged sequentially from the object side to the image side as a first lens group, a first aperture, a second lens group, and a first protective glass; the first lens group includes a first lens, a second lens, and a third lens, wherein the first lens is a meniscus negative lens with negative optical power, the second lens is a convex-concave negative lens with negative optical power, and the third lens is a meniscus lens with positive optical power; the second lens group includes a fourth lens and a fifth lens, wherein the fourth lens is a biconvex lens with positive optical power, and the fifth lens is a biconcave lens with negative optical power.

[0036] like Figure 2 As shown, the overall focal length of the optical system of the first lens is f, and the combined focal lengths of the first lens group and the second lens group are f and f, respectively. a f b -1≤f a / f b ≤0. The focal lengths of the first, second, third, fourth, and fifth lenses are f1, f2, f3, f4, and f5, respectively, where f1, f2, f3, f4, and f5 satisfy the following ratios with f: 1≤|f1| / f≤3, 1≤|f2| / f≤3, 40≤|f3| / f≤50, 0≤|f4| / f≤1, 1≤|f5| / f≤3. The first lens satisfies the relationship: 1.5≤N d ≤1.7, 30.0≤V d ≤40.0; the second lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The third lens satisfies the relationship: 1.5≤N d ≤1.7, 20.0≤V d ≤30.0; The fourth lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The fifth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; where N d V is the refractive index. dLet be Abbe's constant.

[0037] In this embodiment, the axial distances between the lenses in the first lens satisfy the following relationships: the air gap between the first lens and the second lens is 0.2–0.5 mm; the air gap between the second lens and the third lens is 0.3–0.6 mm; the air gap between the third lens and the first aperture stop is 0.05–0.1 mm; the air gap between the first aperture stop and the fourth lens is 0.03–0.1 mm; the air gap between the fourth lens and the fifth lens is 0.05–0.1 mm; and the air gap between the fifth lens and the first protective glass is 0.3–0.6 mm. The total length of the optical system of the first lens is <3.9 mm.

[0038] In this embodiment, the first, second, third, fourth, and fifth lenses are all plastic aspherical lenses. The equation for the aspherical curve is:

[0039]

[0040] Where z is the distance from the vertex of the aspherical surface to the optical axis at a height of h; c is the paraxial curvature of the aspherical surface; k is the conic constant; and α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

[0041] Through a reasonable combination of materials, the optical system of the first lens achieved design specifications such as short overall length, ultra-wide angle, and narrow-band wavelength imaging, while also effectively correcting aberrations and resulting in good image quality.

[0042] In this embodiment, the optical system of the first lens achieves the following technical specifications:

[0043] (1) Focal length: 0.7≤EFFL≤0.8mm;

[0044] (2) Aperture F-number 4.0;

[0045] (3) Field of view: 2w = 140°;

[0046] (4) Working distance: 10mm;

[0047] (5) Operating wavelengths: 415nm and 540nm;

[0048] (6) Distortion: |distortion|≤50%.

[0049] To achieve the above design parameters, the specific parameters of the optical system settings for the first lens in this embodiment are shown in the table below:

[0050]

[0051]

[0052] The aspherical coefficients of each aspherical lens in the optical system of the first lens in this embodiment are shown in the table below:

[0053]

[0054] In this embodiment, the optical system of the first lens achieves a large field of view, high resolution, and compact structure by rationally allocating the optical power, surface shape, center thickness, and on-axis distance between each lens. This satisfies the lens imaging performance requirements while ensuring the overall system has an axial length of 3.82mm.

[0055] like Figure 3 The figure shows the MTF curve of the first lens at a wavelength of 415nm. The MTF of the entire field of view is greater than 0.3 at the Nyquist frequency of 178lp / mm.

[0056] like Figure 4 The figure shows the MTF curve of the first lens at a wavelength of 540nm. The MTF of the entire field of view is greater than 0.2 at the Nyquist frequency of 178lp / mm.

[0057] like Figure 5 The image shows a dot plot of the first lens at a wavelength of 415nm. The RMS radius of each field of view is smaller than the Airy disk radius.

[0058] like Figure 6 The image shows a dot plot of the first lens at a wavelength of 415nm. The RMS radius of each field of view is smaller than the Airy disk radius.

[0059] like Figure 7 The image shown is the field curvature distortion diagram of the first lens at a wavelength of 415nm. It is pincushion distortion, with the maximum distortion being greater than -50%.

[0060] like Figure 8 The image shown is the field curvature distortion diagram of the first lens at a wavelength of 540nm. It is pincushion distortion, with the maximum distortion being greater than -50%.

[0061] like Figure 9 The image shows the relative illumination diagram of the first lens, with a relative illumination of 0.4 or higher across the entire field of view.

[0062] like Figure 10As shown, the optical system of the second lens consists of a third lens group, a second aperture, a fourth lens group, and a second protective glass arranged sequentially from the object side to the image side. The third lens group includes a sixth lens, which is a convex-concave positive lens with positive optical power. The fourth lens group includes a cemented lens and a ninth lens. The cemented lens is formed by cementing a seventh lens and an eighth lens and has positive optical power. The seventh lens is a biconvex lens with positive optical power, the eighth lens is a concave-convex lens with negative optical power, and the ninth lens is a convex-concave lens with positive optical power.

[0063] like Figure 11 As shown, the overall focal length of the optical system of the second lens is f*, and the combined focal lengths of the third and fourth lens groups are f* respectively. a f* b -4≤f* a / f* b ≤-2. The focal lengths of the sixth lens, the cemented lens, and the ninth lens are f*1, f*, and f*, respectively. 2-3 f*4, where f*1 and f*4 are... 2-3 f*4 and f* satisfy the following ratios: 1≤|f*1| / f*≤3, 0≤|f* 2-3 | / f*≤1, 5≤|f*4| / f*≤6. The sixth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; The seventh lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The eighth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; The ninth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; where N d V is the refractive index. d Let be Abbe's constant.

[0064] In this embodiment, the axial distances between the lenses in the second lens satisfy the following relationships: the air gap between the sixth lens and the second aperture stop is 0.2–0.5 mm; the air gap between the second aperture stop and the cemented lens is 0.05–0.1 mm; the air gap between the cemented lens and the ninth lens is 0.2–0.5 mm; and the air gap between the ninth lens and the second protective glass is 0.4–0.7 mm. The total length of the optical system of the second lens is <3.8 mm.

[0065] In this embodiment, the sixth, seventh, eighth, and ninth lenses are all plastic aspherical lenses. The equation for the aspherical curve is:

[0066]

[0067] Where z is the distance from the vertex of the aspherical surface to the optical axis at a height of h; c is the paraxial curvature of the aspherical surface; k is the conic constant; and α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

[0068] Through a reasonable combination of materials, the optical system of the second lens achieves design specifications such as short overall length, ultra-wide angle, and 1080P resolution, while also effectively correcting aberrations and resulting in good image quality.

[0069] In this embodiment, the optical system of the second lens achieves the following technical specifications:

[0070] (1) Focal length: 1.6≤EFFL≤1.8mm;

[0071] (2) Aperture F-number 4.0;

[0072] (3) Field of view: 2w = 100°;

[0073] (4) Working distance: 20mm;

[0074] (5) Operating wavelength: visible light;

[0075] (6) Distortion: |distortion|≤30%.

[0076] To achieve the above design parameters, the specific parameters of the optical system settings for the second lens in this embodiment are shown in the table below:

[0077]

[0078] The aspherical coefficients of each aspherical lens in the optical system of the second lens in this embodiment are shown in the table below:

[0079]

[0080] In this embodiment, the optical system of the second lens achieves high clarity, low distortion, and a compact structure by rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis distance between each lens. This satisfies the lens imaging performance requirements while ensuring the axial length of the entire system is only 3.724 mm.

[0081] like Figure 12 The image shows the MTF curve of the second lens. The MTF of the entire field of view is greater than 0.2 at the Nyquist frequency of 178 lp / mm.

[0082] like Figure 13 As shown, this is a dot plot of the second lens, where the RMS radius of each field of view is smaller than the CMOS pixel size.

[0083] like Figure 14 The image shown is a field curvature distortion diagram for the second lens, with the maximum distortion being less than 30%.

[0084] like Figure 15 The image shows the relative illumination diagram of the second lens, with a relative illumination of 0.5 or higher across the entire field of view.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A dual-lens capsule endoscope lens, characterized in that, The capsule endoscope comprises two lenses with different imaging capabilities: the first lens is a narrowband imaging lens, and the second lens is a high-definition ultra-wide-angle lens. The optical system of the first lens, from object to image, consists of a first lens group, a first aperture, a second lens group, and a first protective glass. The first lens group includes a first lens, a second lens, and a third lens. The first lens is a meniscus negative lens with negative optical power, the second lens is a convex-concave negative lens with negative optical power, and the third lens is a meniscus lens with positive optical power. The second lens group includes a fourth lens and a fifth lens. The fourth lens is a biconvex lens with positive optical power, and the fifth lens is a biconcave lens with negative optical power. The optical system of the second lens consists of a third lens group, a second aperture, a fourth lens group, and a second protective glass arranged sequentially from the object side to the image side. The third lens group includes a sixth lens, which is a convex-concave positive lens with positive optical power. The fourth lens group includes a cemented lens and a ninth lens. The cemented lens is formed by cementing a seventh lens and an eighth lens and has positive optical power. The seventh lens is a biconvex lens with positive optical power, the eighth lens is a concave-convex lens with negative optical power, and the ninth lens is a convex-concave lens with positive optical power. The overall focal length of the optical system of the first lens is f, and the combined focal lengths of the first lens group and the second lens group are f and f, respectively. a f b -1≤f a / f b ≤0; The focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are f1, f2, f3, f4, and f5, respectively, wherein f1, f2, f3, f4, and f5 satisfy the following ratios with f: 1≤|f1| / f≤3, 1≤|f2| / f≤3, 40≤|f3| / f≤50, 0≤|f4| / f≤1, 1≤|f5| / f≤3; The first lens satisfies the relationship: 1.5 ≤ N d ≤1.7, 30.0≤V d ≤40.0; the second lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The third lens satisfies the relationship: 1.5≤N d ≤1.7, 20.0≤V d ≤30.0; The fourth lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The fifth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; where N d V is the refractive index. d It is Abbe's constant; The on-axis distances between the lens elements in the first lens satisfy the following relationships: the air gap between the first lens and the second lens is 0.2–0.5 mm; the air gap between the second lens and the third lens is 0.3–0.6 mm; the air gap between the third lens and the first aperture stop is 0.05–0.1 mm; the air gap between the first aperture stop and the fourth lens is 0.03–0.1 mm; the air gap between the fourth lens and the fifth lens is 0.05–0.1 mm; and the air gap between the fifth lens and the first protective glass is 0.3–0.6 mm.

2. The dual-lens capsule endoscope lens according to claim 1, characterized in that, The total length of the optical system of the first lens is <3.9mm.

3. The dual-lens capsule endoscope lens according to claim 1, characterized in that, The overall focal length of the optical system of the second lens is f*, and the combined focal lengths of the third and fourth lens groups are f* respectively. a f* b -4≤f* a / f* b ≤-2; the focal lengths of the sixth lens, the cemented lens, and the ninth lens are f*1, f*, and f*, respectively. 2-3 f*4, where f*1 and f*4 are... 2-3 f*4 and f* satisfy the following ratios: 1≤|f*1| / f*≤3, 0≤|f* 2-3 | / f*≤1, 5≤|f*4| / f*≤6.

4. A dual-lens capsule endoscope lens according to claim 3, characterized in that, The sixth lens satisfies the relationship: 1.6 ≤ N d ≤1.8, 20.0≤V d ≤30.0; The seventh lens satisfies the relationship: 1.5≤N d ≤1.7, 50.0≤V d ≤60.0; The eighth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; The ninth lens satisfies the relationship: 1.6≤N d ≤1.8, 20.0≤V d ≤30.0; where N d V is the refractive index. d Let be Abbe's constant.

5. A dual-lens capsule endoscope lens according to claim 3, characterized in that, The on-axis distances between the lenses in the second lens satisfy the following relationships: the air gap between the sixth lens and the second aperture stop is 0.2-0.5 mm; the air gap between the second aperture stop and the cemented lens is 0.05-0.1 mm; the air gap between the cemented lens and the ninth lens is 0.2-0.5 mm; and the air gap between the ninth lens and the second protective glass is 0.4-0.7 mm.

6. A dual-lens capsule endoscope lens according to claim 1, characterized in that, The total length of the optical system of the second lens is <3.8mm.

7. A dual-lens capsule endoscope lens according to claim 1, characterized in that, The first lens is used to acquire images of the digestive tract mucosa, and the second lens is used to acquire images of the overall tissue structure and morphological information.

Images