Phosphor illumination system for endoscopic imaging

Abstract

An endoscope includes: a phosphor layer; and a light output layer; wherein the light output layer emits a first excitation light and a second excitation light, and the first and second combined light illuminate an object space through the phosphor layer; the intensity of the first excitation light has an absolute maximum value at a first peak wavelength; the intensity of the second excitation light has an absolute maximum value at a second peak wavelength different from the first peak wavelength; the phosphor layer includes one or more phosphors; each of the one or more phosphors is configured to be excited by the first excitation light to generate a first excited light of the corresponding phosphor; each of the one or more phosphors is configured to be excited by the second excitation light to generate a second excited light of the corresponding phosphor.

Description

Technical Field

[0001] This application relates to an illumination system for endoscopic imaging. In particular, the illumination system includes a phosphor. Background Technology

[0002] To emphasize clinical information, spectral illumination of target molecules with optical properties in the human body (such as autofluorescent molecules like hemoglobin and lipofuscin) is used in medical imaging, especially in endoscopy.

[0003] For example, Figure 1 The absorption spectra of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) are shown, each exhibiting its own first absorption peak in the wavelength range of 400 to 450 nm. The second absorption peak (green spectrum) is in the range of 520 nm to 590 nm.

[0004] Differences in absorption are used to visualize bleeding points during treatment. For example, using green, amber, and red spectra, the highest absorption comes from the green spectrum, the second highest absorption is from amber, and the lowest absorption is from red. In this way, bleeding points are visualized along with other biomedical information.

[0005] In addition, some imaging agents, such as ICG (indocyanine green), AF488 and the IRdye family, can be used for fluorescence imaging and sometimes for phototherapy, such as PDT (photodynamic therapy) and PIT (photoimmunotherapy).

[0006] Because molecules and imaging agents possess their own absorption / excitation and emission properties, suitable spectral illumination is required for illumination optics and light sources. Furthermore, special objectives are typically used to obtain emitted light with a good signal-to-noise ratio from these molecules and imaging agents. These usually include excitation cutoff filters or equivalent optics.

[0007] However, endoscopes typically require white light imaging, so they usually include a white light illumination (WLI) option. Because the space available for the light source within an endoscope is very limited, especially when the light source is embedded in one side of the endoscope, the possible arrangements are restricted. Summary of the Invention

[0008] A rigid tip portion of an endoscope or capsule endoscope according to claim 1 is provided. Furthermore, an endoscope and an endoscope system, as defined in the respective claims, are provided, the endoscope and endoscope system employing the rigid tip portion as described in claim 1. Even further, an endoscope system as defined in the respective independent claims is provided.

[0009] The rigid tip and capsule-shaped endoscope allow for the provision of spectral illumination (e.g., for vascular imaging) and wave-linked endoscope (WLI) respectively, while requiring only limited space. Furthermore, illumination efficiency is improved because all the phosphors in the fluorophore layer contribute to both spectral illumination and WLI. In some embodiments, the spectral shape of the illumination can be adjusted. Attached Figure Description

[0010] Figure 1 The absorption spectra of oxyhemoglobin and deoxyhemoglobin are shown;

[0011] Figure 2 A schematic cross-section of the rigid tip 1 of the endoscope is shown;

[0012] Figure 3 The excitation and emission spectra of the Y3Al5O12:Ce (also known as YAG:Ce) phosphor are shown;

[0013] Figure 4 The illustration schematically depicts spectral illumination for vascular imaging and WLI according to an embodiment of the invention;

[0014] Figure 5 Some plan views of rigid tips are shown;

[0015] Figure 6 Cross-sections of some example lighting systems are shown;

[0016] Figure 7 Some example lighting systems are shown;

[0017] Figure 8 Some example lighting systems that include optical fibers are shown;

[0018] Figure 9 schematically shows the electronic configuration of the example endoscope; and

[0019] Figure 10 The emission spectrum of the red phosphor is shown. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings. Unless otherwise stated, the features of the various embodiments can be freely combined with each other. However, it should be clearly understood that the description of certain embodiments is given by way of example only and is in no way intended to limit the invention to the details disclosed.

[0021] In the diagrams, the same numbers represent corresponding parts, which are distinguished by different letters. These diagrams are for illustrative purposes only. In particular, the dimensions are not to scale.

[0022] Figure 2A schematic cross-section of the rigid tip 1 through the endoscope is shown; the rigid tip 1 may include a portion larger than... Figure 2 The schematic diagram shows more components, such as work channel 22. Unless otherwise specified or explicitly stated in the context, Figure 2 The descriptions therein apply accordingly to capsule endoscopes.

[0023] Although capsule endoscopes can be used alone, the proximal end of the rigid tip 1 is typically connected to a rigid or flexible shaft to form the endoscope. This connection can be direct or indirect, via an angle segment.

[0024] The rigid tip portion 1 includes a light output layer 3 and a phosphor layer 2. Furthermore, the rigid tip portion 1 typically includes an imaging system 20, which includes an objective lens 21 for imaging the object space 100. Figure 2 In this embodiment, the object space 100 is located in front of the distal end of the rigid tip 1 of the endoscope. However, in some embodiments, the object space 100 imaged by the imaging system 20 may be located on the side of the rigid tip 1. The object space 100 may be a cavity, such as a cavity inside a human or animal body, or a portion thereof.

[0025] Furthermore, the rigid tip 1 includes an illumination system 23, which comprises a light output layer 3 and a phosphor layer 2. The illumination system 23 is arranged to illuminate the object space 100, particularly a portion of the object space 100 imaged by the imaging system 20. Figure 2 In this embodiment, the illumination system 23 is arranged next to the imaging system 20. However, in some embodiments, the illumination system 23 may be arranged around the imaging system 20 such that, when viewed from the object space 100, the illumination system 23 completely or partially surrounds the imaging system 20 (see, for example, see...). Figure 5 a) and b)).

[0026] Figure 5 Examples of rigid tip 1 as seen from a plan view of object space 100 are shown. The phosphor layer 2 is drawn transparently, making the light output layer 3 with the light source 4 visible through the phosphor layer 2. (See diagram below.) Figure 5 As shown in a), the phosphor layer can be continuous, such that a single portion of the phosphor layer 2 covers multiple light sources 4. Figure 5 As shown in 5b) to 5d), the phosphor layer 2 can be divided into several sections, which are separated from each other. Each section can cover one or more light sources 4. The illumination system 23 can include a single light source 4 covered by the phosphor layer 2. Figure 5 (Not shown in the image). The arrangement of the illumination system 23 relative to the objective lens 21 is not limited to... Figure 5 The arrangement shown is not fixed, but can be changed as needed.

[0027] The light output layer 3 is configured to emit either a first excitation light or a second excitation light simultaneously. In some embodiments, the light output layer 3 may also emit both a first excitation light and a second excitation light simultaneously. That is, the emission of the first excitation light (the intensity of the first excitation light, at least regardless of whether the first excitation light is emitted) may be independent of the emission of the second excitation light (the intensity of the second excitation light, at least regardless of whether the second excitation light is emitted). The endoscope system may include appropriate control devices.

[0028] At least in the visible spectrum (400 to 750 nm), the intensity of the first excitation light has an absolute maximum value at a first peak wavelength. At least in the visible spectrum (400 to 750 nm), the intensity of the second excitation light has an absolute maximum value at a second peak wavelength different from the first peak wavelength. The light output layer 3 can emit more than two different excitation lights, each of which has an absolute maximum intensity in the visible spectrum at a corresponding peak wavelength different from the peak wavelengths of the other excitation lights.

[0029] When viewed from object space 100, phosphor layer 2 can cover light output layer 3. Phosphor layer 2 can be in contact with light output layer 3, including light source 4 (e.g., Figure 6 (as shown in the cross-section of b), it can also be spaced apart from the light output layer 3 (e.g.) Figure 2 and Figure 6 (as shown in the cross-section of a). The phosphor layer 2 may include one or more phosphors. The one or more phosphors may be embedded in a matrix of a transparent material (e.g., a transparent resin) in the wavelength range associated with spectral illumination and WL (i.e., typically in the visible spectrum), or the phosphor layer 2 may include only phosphors. Typically, the composition of the phosphor layer 2 is substantially constant. That is, the composition of the phosphor layer 2 integrated over the thickness of the phosphor layer 2 varies by no more than 10% in the lateral direction. Preferably, this variation does not exceed 5%, more preferably no more than 2%. Accordingly, the composition of the phosphor layer 2 is substantially constant in the thickness direction of the phosphor layer (not exceeding 10%, preferably no more than 5%, more preferably no more than 2%). Typically, the thickness of the phosphor layer 2 is substantially constant (±10%, preferably ±5%). Due to these characteristics, the manufacture of the phosphor layer 2 is simplified.

[0030] like Figure 2As indicated by the arrows in the center, light from the light output layer 3 (first excitation light, second excitation light) is incident on the phosphor layer 2 and passes through it, illuminating the object space 100. When the light from the light output layer 3 passes through the phosphor layer 2, it excites each phosphor in the phosphor layer 2 through luminescence, such as fluorescence or phosphorescence. That is, each phosphor generates its own first or second excited light according to the excitation light. Therefore, the object space 100 is illuminated by combined light, which is the excited light from one or more phosphors in the phosphor layer 2 and the residual light from the light output layer 3 that has passed through the phosphor layer 2 without being excited. Note that if small particles (including bubbles) are present in the phosphor 2, the light that has passed through the phosphor layer 2 without being excited may be scattered by the phosphors and / or by the small particles (including bubbles).

[0031] The excitation light from the light output layer 3 and the phosphors from the phosphor layer 2 are configured such that each phosphor can be excited, thereby generating its corresponding excited light at its respective peak wavelength. For example, if the light output layer 3 emits two different excitation lights with peak wavelengths λ1 and λ2, and the phosphor layer 2 includes one phosphor, then the phosphor is excited by each peak wavelength λ1 and λ2. Correspondingly, if the light input layer 3 emits two different excitation lights with peak wavelengths λ1 and λ2, and the phosphor layer 2 includes two phosphors, A and B, then phosphor A is excited by each peak wavelength λ1 and λ2, and phosphor B is also excited by each peak wavelength λ1 and λ2. The phosphor layer 2 does not contain any phosphors that are excited by (at least) one of the excitation lights to generate the corresponding excited light, but are not excited by (at least) the other excitation light. Therefore, no single phosphor merely acts as a scatterer of the excitation light, thus improving illumination efficiency.

[0032] As described above, the phosphor layer 2 may additionally include some transparent material (e.g., transparent resin) that is not excited by any excitation light.

[0033] For each phosphor in phosphor layer 2, the normalized spectrum of the excited light produced by different excitation lights may vary depending on the excitation wavelength. However, generally, the normalized spectra are substantially the same and independent of the excitation light, but their absolute intensities may vary depending on the excitation light. Therefore, normalization is about intensity. For each excitation light and each phosphor, the excitation ratio is defined as the ratio of the amount of excited light produced by the excitation light to the amount of excitation light incident on phosphor layer 2. For each phosphor in phosphor layer 2, the excitation ratio of at least one excitation light is different from that of another excitation light. Therefore, if light output layer 3 can emit multiple excitation lights simultaneously, for each excitation light with substantially the same normalized spectrum, the ratio of the excited light to the corresponding excitation light in the combined light may vary due to differences in the relative intensities of the excitation lights. That is, the spectrum of the combined light can be shaped as needed.

[0034] Conversely, if there is a one-to-one correspondence between the phosphor and the excitation light, then the ratio of the excited light to the excitation light in the combined light is fixed.

[0035] Examples of excitation light and phosphors will be described in more detail below. In this section, it is assumed that the light output layer 3 is configured to emit two different excitation lights (a first excitation light having a first peak wavelength and a second excitation light having a second peak wavelength). However, embodiments of the present invention are not limited to only two excitation lights, but may emit three or even more than three different excitation lights.

[0036] The peak wavelength of the first excitation light can be in the range of 400 nm to 430 nm. The peak wavelength of the second excitation light can be in the range of 440 nm to 480 nm. The phosphor may include...

[0037] -Y3Al5O12:Ce

[0038] -CaSc2O4:Ce

[0039] -Y3(Al,Ga)5O12:Ce

[0040] -Lu3Al5O12:Ce

[0041] -Lu3(Al,Ga)5O12:Ce

[0042] -Y3Al5O12:Ce

[0043] -La3Si6N11:Ce

[0044] At least one of -(La,Y)3Si6N11:Ce.

[0045] The amount of Ce in these phosphors can range from 0.5 wt% to 5 wt% or from 0.5 mol% to 5 mol%.

[0046] like Figure 3 As shown, for the example of Y3Al5O12:Ce (also known as YAG:Ce) as a phosphor, both violet excitation light (in the range of 400 to 430 nm) and blue excitation light (in the range of 430 to 480 nm) can excite it. Figure 3 The "emission" in the text exhibits a broad spectrum of excitation light around 570 nm. For example... Figure 4 As shown, if the phosphor is excited by violet excitation light (λ1), then the intensity of the excitation light (λ3) is quite low, and the combined light is suitable for vascular imaging. Figure 4 (Top left corner). On the other hand, if the phosphor is excited by blue excitation light (λ2), the intensity of the excitation light increases, making the combined light appear almost white (according to CIE 1931, near the white point). Figure 4 (bottom left corner). If both λ1 and λ2 excite the phosphor, the combined light may be closer to... Figure 4 The white dot is shown on the right.

[0047] Further improvements to WLI can be achieved if phosphor layer 2 additionally includes one of the following phosphors whose excitation light is in the red range:

[0048] -CaAlSi(ON)3:Eu

[0049] -CaAlSiN3:Eu

[0050] -(SrCa)AlSiN3:Eu

[0051] -CaAlSi(ON)3:Eu

[0052] -Li2SiN2:Eu 3+

[0053] -Sr[Mg3SiN4]:Eu 2+

[0054] -CaAlSiN3:Eu 2+

[0055] -Li2Ca2[Mg2Si2N6]:Eu 2+

[0056] -Ca 18.75 Li 10.5 [Al 39 N 55 ]:Eu 2+

[0057] -Ba[Mg3SiN4]:Eu 2+

[0058] -Sr4[LiAl 11 N 14 ]:Eu 2+

[0059] -Ca[LiAl3N4]:Eu 2+

[0060] -Ba[Li2(Al2Si2)N6]:Eu 2+

[0061] -Sr[LiAl3N4]:Eu 2+ .

[0062] The amount of Eu in these phosphors can range from 0.5 wt% to 5 wt% or from 0.5 mol% to 5 mol%.

[0063] As shown in Table 1, both purple and blue excitation light excite phosphors (the first group of phosphors and the second group of phosphors).

[0064] [Table 1]

[0065] Fluorescent material 1 (e.g., Y3Al5O12:Ce) yes yes Phosphor 2 (e.g., CaAlSi(ON)3:Eu) yes yes

[0066] Table 1: Excitation characteristics of phosphors

[0067] Each red phosphor in the second group (i.e., CaAlSi(ON)3:Eu; CaAlSiN3:Eu; (SrCa)AlSiN3:Eu; CaAlSi(ON)3:Eu; Li2SiN2:Eu) 3+ Sr[Mg3SiN4]:Eu 2+ ;CaAlSiN3:Eu 2+ ;Li2Ca2[Mg2Si2N6]:Eu 2+ ;Ca 18.75 Li 10.5 [Al 39 N 55 ]:Eu 2+ Ba[Mg3SiN4]:Eu 2+ ;Sr4[LiAl 11 N 14 ]:Eu 2+ ;Ca[LiAl3N4]:Eu 2+ Ba[Li2(Al2Si2)N6]:Eu 2+ ; and Sr[LiAl3N4]:Eu 2+() or combinations thereof can be used not only as an adjunct to the first group of fluorophores, but also as the sole fluorophore (combination) in fluorophore layer 2. For example Figure 10 As shown, if a phosphor is combined with violet (or blue) excitation light (within the above wavelength range) and green excitation light (within the wavelength range of 520 nm to 590 nm), the combined light is white light and spectral illumination. Figure 10 The emission spectrum of one of the second group of red phosphors is shown. For all phosphors, a small amount of blue emission is unlikely to be observed.

[0068] The following conditions may apply:

[0069] • The wavelength of the first peak differs from that of the second peak by at least 5 nm (preferably at least 10 nm, more preferably at least 15 nm);

[0070] • The full width at half maximum (FWHM) near the first peak wavelength of the emission spectrum of the first excitation light is no greater than 30 nm (preferably no greater than 20 nm, more preferably no greater than 10 nm);

[0071] • The full width at half maximum (FWHM) near the second peak wavelength of the emission spectrum of the second excitation light is no greater than 30 nm (preferably no greater than 20 nm, more preferably no greater than 10 nm).

[0072] In addition, one of the following conditions may apply:

[0073] • The first excitation ratio is at least twice as large as the second excitation ratio (preferably at least four times, more preferably eight times); and

[0074] The second excitation ratio is at least twice as large as the first excitation ratio (preferably at least four times, more preferably eight times).

[0075] The following will explain some details of the light output layer 3.

[0076] The light output layer 3 may include one or more first light sources 4. Each first light source 4 is configured to emit a first excitation light. Each of the one or more first light sources 4 may include at least one of a corresponding first light-emitting diode and a corresponding first laser diode.

[0077] The light output layer 3 may include one or more second light sources 4. Each second light source 4 is configured to emit a second excitation light 4. Each of the one or more second light sources 4 may include at least one of a corresponding second light-emitting diode and a corresponding second laser diode.

[0078] If the light output layer 3 includes first and second LEDs or LDs as light sources 4, the entire lighting system 23 can be embedded in the rigid tip 1. However, at least one of the first light source 4 and the second light source 4 can be the emitting end of an optical fiber that emits excitation light from a light generating device 41 outside the rigid tip 1. For example, the light generating device 41 (e.g., an LED or LD) can be located at the proximal end of the endoscope or in the control box of the endoscope, and the light generated by the light generating device 41 can be propagated from the light generating device 41 to the light output layer 3 through one or more optical fibers 8 (or corresponding glass rods).

[0079] The light output layer 3 may include a mixture of LEDs / LDs and the emitter of the optical fiber 8 (“hybrid configuration”). This hybrid configuration may be advantageous if there is not enough space in the rigid tip 1 for a certain number of LEDs / LDs. Figure 7 An example is shown in b). Figure 7 In b), the right light source 4 is the emitting end of the optical fiber 8 that emits light from the light generating device 41 located near the end (or outside the endoscope), while the left light source 4 is an LED or LD located in the rigid tip 1 at the distal end. If the lighting system 21 includes multiple light sources 4 emitting a first wavelength (or a second wavelength), some of them may be the emitting ends of the optical fiber 8, some may be LEDs / LDs located in the rigid tip 1, or all light sources emitting one wavelength may be LEDs / LDs located in the rigid tip 1, while all light sources 4 emitting another wavelength may be the emitting ends of the optical fiber 8. Although Figure 7 b) shows an example where the light generating device 41 is directly coupled to the light source 4 in the light output layer 3, but as follows regarding Figure 8 As further explained, light from multiple light generating devices 41 can be combined before the light is emitted from the light source 4 in the light output layer 3.

[0080] In some embodiments, at least one of one or more optical fibers can be arranged to emit only one of the excitation beams, without emitting the others. For example, the input end of the optical fiber can be directly connected to a corresponding light generating device that emits only the corresponding excitation beam. This is in Figure 7 As shown in a. Here, the light generating device 41 is connected to the corresponding optical fiber 8 via an optical fiber connector 8a.

[0081] In some embodiments, at least one of one or more optical fibers can be arranged to emit multiple excitation beams. In this case, the excitation beam from the light generating device can be passed through a beam combiner (such as...) before being input to the optical fiber 8 having its emitting end in the light output layer 3. Figure 8 As shown in 8a and 8b, used for two and three wavelengths respectively) or fiber couplers (such as...) Figure 8 (As shown in c) Combine them. Figure 8In b), the light from the three light generating devices 41 is split into two optical fibers 8 by an optical fiber coupler / decoupler 81, resulting in two light sources 4 in the light output layer 3 of the rigid tip 1. Of course, the number of optical fibers 8 and light sources 4 is not limited to two; there can be three or more. Accordingly, as... Figure 8 As shown in c), an optical fiber coupler 81 can be used instead of a beam combiner 80 to combine the light from multiple light generating devices 41 into one or more optical fibers 8.

[0082] In some embodiments, the light output layer 3 of the rigid tip 1 does not include any LEDs / LDs, but only includes the emitting end of an optical fiber. In one case, the light output layer 3 does not include any LEDs / LDs, but includes a single emitting end of an optical fiber as a single light source capable of emitting multiple excitation lights.

[0083] For each light source in light output layer 3 (see...) Figure 5 d)), or for several light sources (see Figure 5 b) and 5c)), or for all light sources (see b) and 5c)). Figure 5 a)) The phosphor 2 can have independent portions. For example, the phosphor layer 2 can be arranged such that a first excitation light from a first light source is incident on its first portion, while a second excitation light from a second light source is incident on its second portion. The first portion and the second portion can be separated by a gap.

[0084] The light sources in the light output layer 3 can be arranged in multiple unit cells. Within each unit cell, the light sources are arranged in the same manner (e.g., their respective distances and relative orientations, see...). Figure 5 (b) and (c)). Excitation light from each unit cell can be incident on the corresponding independent portion of phosphor layer 2, and excitation light from multiple unit cells can also be incident on the common portion of phosphor layer 2.

[0085] In some embodiments where the emitting end of one or more optical fibers serves as the light source of the light output layer 3, the phosphor layer 2 can be arranged between the light generating device 41 and the optical fiber 8, wherein the emitting end of the optical fiber 8 is arranged in the light output layer 3. In these embodiments, the emitting end of the optical fiber 8 emits combined light to illuminate the object space 100 without passing through another phosphor layer 2 in the rigid tip 1. The same effect as when the phosphor layer 2 is arranged in the proximal end of the rigid tip 1 can be achieved.

[0086] Figure 9 schematically shows the electronic configuration of an example endoscope. In Figure 9, LD / LEDs are arranged at light sources 4 in the rigid tip 1. They are controlled (i.e., at least turned on and off) by a light source control unit in a processor unit located outside the endoscope and connected to its proximal end. The imaging system 20 provides the acquired images to an image processing unit via an A / D converter, and from the image processing unit to a CPU. Typically, the A / D converter is located inside the endoscope, but in some examples it may also be located externally. The CPU controls the image processing unit, the light source control unit, and a display monitor (if available) for visualizing the images acquired by the imaging system 20.

[0087] Figure 9b )and Figure 9a Correspondingly, the difference lies in that the light generating device 41 (LDs / LEDs) is arranged in the light source unit near the proximal end of the endoscope, and the optical fiber guides the light emitted by the light generating device 41 to its emitting end (light source 4) in the light output layer 3. Figure 9b An example is shown in the figure, where each optical fiber 8 corresponds to a light generating device 41 and a light source 4. Optionally, as Figure 9b As shown in the dashed box in the figure, as about Figure 8 As explained, light from different light-generating devices can be coupled.

Claims

1. A rigid tip portion of an endoscope or capsule endoscope, comprising: fluorophore; and Light output layer; in The light output layer is configured to emit a first excitation light, and the object space is illuminated by the first combined light passing through the phosphor layer. The light output layer is configured to emit a second excitation light, and the object space is illuminated by the second combined light through the phosphor layer. The intensity of the first excitation light has an absolute maximum value at the first peak wavelength; The intensity of the second excitation light has an absolute maximum value at a second peak wavelength that is different from the first peak wavelength; The phosphor layer includes one or more phosphors; Each of the one or more phosphors is configured to be excited by the first excitation light to generate a first excited light of the corresponding phosphor. Each of the one or more phosphors is configured to be excited by the second excitation light to generate a second excited light of the corresponding phosphor. The first combined light includes the first excited light of the one or more phosphors generated by the first excitation light and the remaining first excitation light that passes through the phosphor layer from the light output layer without generating any excited light; The second combined light includes the second excited light of the one or more phosphors generated by the second excitation light, and the remaining second excitation light that passes through the phosphor layer from the light output layer without generating any excited light. For the one or more phosphors mentioned above: The ratio of the amount of the corresponding first excited light generated by the first excitation light to the amount of the first excitation light incident on the phosphor layer is the first excitation ratio of the corresponding phosphor. The ratio of the amount of the corresponding second excited light generated by the second excitation light to the amount of the second excitation light incident on the phosphor layer is the second excitation ratio of the corresponding phosphor. The first excitation ratio of each phosphor is different from the second excitation ratio of the corresponding phosphor. The first excitation ratio is at least twice as large as the second excitation ratio; or The second excitation ratio is at least twice as large as the first excitation ratio.

2. The rigid tip of the endoscope or capsule endoscope according to claim 1, wherein the phosphor layer does not include any phosphor configured to be excited by one of the first excitation light and the second excitation light to produce a respective excited light, and configured not to produce a respective excited light if it is excited by the other of the first excitation light and the second excitation light.

3. The rigid tip of the endoscope or capsule endoscope according to any one of claims 1 to 2, wherein, The light output layer includes one or more first light sources, each of which is configured to emit the first excitation light; Each of the one or more first light sources includes at least one of a respective first light-emitting diode and a respective first laser diode.

4. The rigid tip of the endoscope or capsule endoscope according to any one of claims 1 to 2, wherein, The light output layer includes one or more second light sources, each of which is configured to emit the second excitation light; Each of the one or more second light sources includes at least one of a respective second light-emitting diode and a respective second laser diode.

5. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein at least one of the following conditions is met: The first peak wavelength differs from the second peak wavelength by at least 5 nm; The full width at half maximum (FWHM) of the emission spectrum of the first excitation light near the first peak wavelength is no greater than 15 nm; and The full width at half maximum (FWHM) of the emission spectrum of the second excitation light near the second peak wavelength is not greater than 10 nm.

6. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein at least one of the following conditions is met: The first peak wavelength is in the range of 400 nm to 430 nm; and The second peak wavelength is one of the wavelengths in the range of 430 nm to 480 nm.

7. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein... The phosphor includes at least one of the following: -Y3Al5O12:Ce -CaSc2O4:Ce -Y3(Al,Ga)5O12:Ce -Lu3Al5O12:Ce -Lu3(Al,Ga)5O12:Ce -Y3Al5O12:Ce -La3Si6N11:Ce -(La,Y)3Si6N11:Ce.

8. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein... The phosphor includes at least one of the following: -CaAlSi(ON)3:Eu -CaAlSiN3:Eu -(SrCa)AlSiN3:Eu -CaAlSi(ON)3:Eu -Li2SiN2:Eu 3+ -Sr[Mg3SiN4]:I 2+ -CaAlSiN3:Eu 2+ -Li2Ca2[Mg2Si2N6]:Eu 2+ -That 18.75 them 10.5 [Al 39 N 55 ]:I 2+ -Ba[Mg3SiN4]:Eu 2+ -Sr4[LiAl 11 N 14 ]:I 2+ -Ca[LiAl3N4]:I 2+ -Ba[Li2(Al2Si2)N6]:Eu 2+ -Mr[LiAl3N4]:I 2+ .

9. The rigid tip of the endoscope or capsule endoscope according to claim 8, wherein, One of the first peak wavelength and the second peak wavelength is in the range of 520 nm to 590 nm.

10. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein... The light output layer includes a plurality of first light sources, each of which is configured to emit the first excitation light, and a plurality of second light sources, each of which is configured to emit the second excitation light; The phosphor layer includes a first portion, which is arranged such that the first excitation light from the first light source is incident on the first portion; The phosphor layer includes a second portion, which is arranged such that the second excitation light from the second light source is incident on the second portion; The first part and the second part are separated by a gap.

11. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein... The light output layer includes a plurality of first light sources, each of which is configured to emit the first excitation light, and a plurality of second light sources, each of which is configured to emit the second excitation light; At least some of the first light source and the second light source are arranged in a plurality of unit cells; In each of the unit cells, each of the second light sources is arranged in the same manner relative to each of the first light sources.

12. The rigid tip of the endoscope or capsule endoscope according to claim 11, wherein the phosphor layer includes a third portion, the third portion being arranged such that the first excitation light from at least one of the unit cells and the second light source are incident on the third portion. The third part is separated from the remainder of the phosphor layer by a gap.

13. The rigid tip of the endoscope or capsule endoscope according to any one of claims 1 to 2, wherein the fluorophore layer is continuous.

14. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein... The phosphor layer is in contact with and covers the light output layer; or The phosphor layer is spaced apart from the light output layer.

15. The rigid tip of the endoscope or capsule endoscope according to any one of claims 1 to 2, further comprising: An objective lens configured to image at least a portion of the object space.

16. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein, The intensity of the first excitation light can be controlled separately from the intensity of the second excitation light.

17. The rigid tip of an endoscope or capsule endoscope according to any one of claims 1 to 2, wherein, The normalized spectrum of the first excited light is the same as the normalized spectrum of the second excited light.

18. An endoscope comprising a rigid tip portion of the endoscope according to any one of claims 1 to 17 and a flexible or rigid shaft directly or indirectly connected to the proximal end of said rigid tip portion.

19. An endoscope system comprising the endoscope of claim 18, and further comprising... A light generating device is configured to emit one of the first excitation light and the second excitation light; One or more optical fibers; among which The optical output layer includes a corresponding transmitter end for each of the one or more optical fibers; Each of the one or more optical fibers is configured to propagate one of the first excitation light and the second excitation light emitted by the light generating device to the corresponding transmitting end; Each of the emitters is configured to illuminate the object space through the phosphor layer using the first combined light and the second combined light, respectively.

20. The endoscope system of claim 19, wherein... The light generating device is configured to emit another of the first excitation light and the second excitation light.

21. The endoscope system of claim 20, comprising one or more optical fibers, wherein at least one of the optical fibers is configured to propagate a corresponding one of the first excitation light and the second excitation light emitted by the light generating device to the corresponding transmitting end, and is not configured to propagate the other corresponding one of the first excitation light and the second excitation light emitted by the light generating device to the corresponding transmitting end.

22. The endoscope system according to any one of claims 20 and 21, further comprising: The combining device is configured to combine the first excitation light and the second excitation light emitted by the light generating device into a combined excitation light; wherein At least one of the one or more optical fibers is configured to propagate the combined excitation light to the corresponding transmitter.

23. An endoscope system, comprising Rigid tip; A flexible or rigid shaft that is directly or indirectly connected to the proximal end of the rigid tip; The first light source is configured to emit the first excitation light; It is configured as a second light source to emit a second excitation light; A fluorophore layer comprising one or more fluorophores; One or more optical fibers; among which The first light source is arranged such that the first excitation light is incident on the phosphor layer; The second light source is arranged such that the second excitation light is incident on the phosphor layer; The intensity of the first excitation light has an absolute maximum value at the first peak wavelength; The intensity of the second excitation light has an absolute maximum value at a second peak wavelength that is different from the first peak wavelength; Each of the one or more phosphors is configured to be excited by the first excitation light to generate a first excited light of the corresponding phosphor. Each of the one or more phosphors is configured to be excited by the second excitation light to generate a second excited light of the corresponding phosphor. Each of the one or more optical fibers is configured to propagate at least one of the first combination of light and the second combination of light to the transmitting end of the corresponding optical fiber. For each of the optical fibers, the transmitting end of the corresponding optical fiber is disposed in the rigid tip and configured to illuminate an object space by at least one of the first combined light and the second combined light propagating through the corresponding optical fiber; The first combined light includes a first excited light of the one or more phosphors generated by the first excitation light from the first light source and a remaining first excitation light that passes through the phosphor layer from the light source without generating any excited light; The second combined light includes a second excited light from the one or more phosphors generated by the second excitation light from the second light source, and a remaining second excitation light passing through the phosphor layer from the light source without generating any excited light. For each of the one or more phosphors: The ratio of the amount of the corresponding first excited light generated by the first excitation light to the amount of the first excitation light incident on the phosphor layer is the first excitation ratio of the corresponding phosphor. The ratio of the amount of the corresponding second excited light generated by the second excitation light to the amount of the second excitation light incident on the phosphor layer is the second excitation ratio of the corresponding phosphor. The first excitation ratio of each phosphor differs from the second excitation ratio of the corresponding phosphor. The first excitation ratio is at least twice as large as the second excitation ratio; or The second excitation ratio is at least twice as large as the first excitation ratio.

24. The endoscope system of claim 23, wherein the normalized spectrum of the first excited light is the same as the normalized spectrum of the second excited light.

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