Endoscopy system

Abstract

When observing biological tissue using white light or special light, the desired tissue information of the biological tissue is obtained in a clearer state suitable for diagnosis. [Solution] The system comprises a first light source 51 that uses a semiconductor light-emitting element as its light source, a second light source 53 that uses a semiconductor light-emitting element with a different emission wavelength than the first light source 51 as its light source, a wavelength conversion member 57 that is excited and emits light by light emitted from at least one of the first light source 51 and the second light source 53, and a light intensity ratio changing means 55 that changes the light intensity ratio between the light emitted from the first light source 51 and the light emitted from the second light source 53. By arbitrarily generating light emitted from the first light source 51 and the second light source 53, illumination light suitable for diagnosis according to the absorption and scattering characteristics of biological tissue can be provided. This makes it possible to acquire desired tissue information of biological tissue in a clearer state.

Description

[Technical Field]

[0001] This invention relates to an endoscopic system. [Background technology]

[0002] Conventional endoscopes illuminate the observation area of ​​the subject by guiding light from a lamp in a light source device to the tip of the endoscope via a light guide installed inside the endoscope insertion section that is inserted into the subject, and emitting the light from an illumination window at the tip of the endoscope. While white light is normally used for observing biological tissue, in recent years, endoscopes that can perform special light observation, such as highlighting the state of mucosal tissue by irradiating with light of a specific narrowband wavelength or observing autofluorescence from a pre-administered fluorescent substance, have been put into use (Patent Documents 1, 2). With this type of endoscope, by irradiating biological tissue with special light, it is possible to observe, for example, neovascularization occurring in the mucosal layer or submucosa, and to depict the fine structure of the mucosal surface that cannot be obtained with normal observation images.

[0003] In the aforementioned Patent Documents 1 and 2, light emitted from a white light source such as a xenon lamp is extracted using a color filter to obtain only a specific wavelength band, which is then used as special light. In addition to xenon lamps, laser light sources can also be used as white light sources. For example, a light-emitting device has been proposed that generates white light by combining a blue laser light source with a phosphor that emits light excited by this laser (Patent Document 3).

[0004] However, in the endoscopic devices described in Patent Documents 1 and 2, light from a white light source is time-divided by a color filter, causing light of different wavelengths (R, G, B light, etc.) to be emitted sequentially from the surface. Therefore, in order to obtain a full-color observation image, it is necessary to combine multiple frames (R, G, B) of captured images, which hinders the increase in the frame rate of the observation image. In addition, since illumination light is generated by light absorption by the color filter, a decrease in light intensity is unavoidable, which increases the noise component of the observation image. It is possible to increase sensitivity by lowering the frame rate, but in that case, the image becomes more prone to blurring.

[0005] On the other hand, in special optical diagnosis, tissue information from the superficial to the deep layers of biological tissue is an important object of observation. For example, in gastrointestinal cancer, tumor blood vessels appear in the superficial layer of the mucosa from an early stage, and these tumor blood vessels show dilation, tortuousness, and increased density compared to normal blood vessels visible in the superficial layer. Therefore, the type of tumor can be differentiated by carefully examining the characteristics of the blood vessels. However, with endoscopic devices that use the above-mentioned color filters, it is difficult to limit the transmission wavelength band of the color filter to a specific narrow band, especially when it is necessary to observe tissue information from the superficial layer of biological tissue. Moreover, illumination light limited to a narrow band does not provide sufficient light intensity, which is a disadvantage as it leads to a deterioration in the image quality of the observation image. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 3583731 [Patent Document 2] Special Publication No. 6-40174 [Patent Document 3] Japanese Patent Publication No. 2006-173324 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The present invention aims to provide an endoscopic system that can acquire desired tissue information of biological tissue in a clearer state suitable for diagnosis when observing biological tissue using white light or special light. [Means for solving the problem]

[0008] The present invention consists of the following configuration. An endoscope system comprising an endoscope, a light source device, a processor, and a monitor, The system comprises a first light source that uses a semiconductor light-emitting element that emits blue light, and a second light source that uses a semiconductor light-emitting element that emits purple light. The device includes a wavelength conversion member that generates emitted light by absorbing a portion of the emitted light from the first light source and exciting it, and the blue light that is transmitted without being absorbed, thereby generating emitted light. The system includes an optical element positioned in the optical path of the light emitted from the second light source, which combines the light with the light associated with the first light source. The system allows selection of observation light modes, including a first observation using white light and a second observation using illumination light with a spectrum different from that of the white light. A switching unit that switches the observation light mode by operating a button, An endoscope system having an adjustment unit that adjusts the light intensity of the first light source and the second light source by moving an indicator within a predetermined range. [Effects of the Invention]

[0009] According to the endoscopic system of the present invention, when observing biological tissue using white light or special light in a specific wavelength band, desired tissue information of the biological tissue can be obtained in a clearer state suitable for diagnosis. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of an endoscope device using an endoscope light source device for illustrating embodiments of the present invention. [Figure 2] Figure 1 is a block diagram of the endoscope device. [Figure 3] This graph shows the emission spectra of laser light from a violet laser source, blue laser light from a blue laser source, and light after the blue laser light has been wavelength-converted by a phosphor. [Figure 4] This is a detailed block diagram of the image processing unit. [Figure 5] This is a schematic diagram illustrating the blood vessels in the mucosal surface of living tissue. [Figure 6] This is an explanatory diagram showing a schematic example of an observation image obtained using an endoscope. [Figure 7a] This is a magnified image of the inside of the lip observed using an endoscope, illuminated with white light. [Figure 7b]This is an enlarged observation image of the inner lip with a light quantity ratio of 50:50 observed by an endoscope device. [Figure 7c] This is an enlarged observation image of the inner lip with a light quantity ratio of 75:25 observed by an endoscope device. [Figure 8] This is an explanatory diagram showing an example of the display screen of a display unit that displays an observation image obtained by an endoscope device. [Figure 9] This is an explanatory diagram showing another example of the display screen of a display unit that displays an observation image obtained by an endoscope device. [Figure 10] This is a graph showing the relationship between the applied current to the light source and the light emission amount. [Figure 11] This is a graph showing the pulse current superposition waveform of the applied current. [Figure 12] This is an explanatory diagram showing various drive waveforms (a), (b), (c) by pulse modulation control. [Figure 13] This is a graph showing a control example in which the light emission amount of the light source alternately becomes maximum. [Figure 14] This is a graph showing a schematic relationship between the absorption wavelength band of hemoglobin and the emission wavelength of each light source. [Figure 15] This is an explanatory diagram schematically showing the state of the display image of the display unit when an endoscope operator moves the endoscope insertion portion within the subject, performs observation with narrow-band light at a desired observation position, and then moves to the next observation position. [Figure 16] This is an explanatory diagram showing an example of arranging and simultaneously displaying a normal image and a narrow-band light image in separate regions within the same screen. [Figure 17] This is an explanatory diagram showing an example of overlapping and simultaneously displaying a narrow-band light image of a desired range within a normal image. [Figure 18] This is an explanatory diagram showing a light quantity ratio table in which the light quantity ratio for an endoscope operator is registered. [Figure 19] This is an explanatory diagram showing an example of displaying a preset light quantity ratio on the display unit. [Figure 20] This is an operation explanatory diagram of a changeover switch. [Figure 21] This is an explanatory diagram showing a color conversion coefficient table for the light quantity ratio. [Figure 22] This graph shows the absorption spectra of hemoglobin (Hb) with a low oxygen concentration and oxygen-saturated oxyhemoglobin (HbO2). [Figure 23] This block diagram shows an example configuration of a light source device equipped with multiple laser light sources and an endoscope. [Figure 24] This block diagram shows an example configuration of a light source device and endoscope with integrated optical paths. [Figure 25] Figure 24 is a graph showing an example of the emission spectrum produced by the light source device and phosphor shown. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. Figure 1 is a schematic diagram of an endoscope device using an endoscope light source device for illustrating an embodiment of the present invention, and Figure 2 is a block diagram of the endoscope device shown in Figure 1. The endoscopic device 100 shown in Figure 1 comprises an endoscope 11 and a control device 13 to which the endoscope 11 is connected. The control device 13 is connected to a display unit 15 for displaying image information and the like, and an input unit 17 for receiving input operations. The endoscope 11 is an electronic endoscope having an illumination optical system that emits illumination light from the tip of the endoscope insertion section 19, and an imaging optical system that includes an image sensor for imaging the area to be observed.

[0012] The endoscope 11 comprises an endoscope insertion section 19 inserted into the subject, an operating section 23 for performing operations such as bending the tip of the endoscope insertion section 19, suction from the tip of the endoscope insertion section 19, and air / water insufflation, a connector section 25 for detachably connecting the endoscope 11 to the control device 13, and a universal cord section 27 connecting the operating section 23 and the connector section 25. Although not shown in the figures, the endoscope 11 is provided with various channels inside, such as a forceps channel for inserting tissue sampling instruments and channels for air / water insufflation.

[0013] The endoscope insertion section 19 consists of a flexible section 31, a curved section 33, and a tip section (hereinafter also referred to as the endoscope tip) 35. The endoscope tip 35 is equipped with illumination ports 37A and 37B for irradiating the area to be observed with light, and an image sensor 21 such as a CCD (charge coupled device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor for acquiring image information of the area to be observed. An imaging member 39 such as an objective lens is attached to the image sensor 21.

[0014] The bending section 33 is provided between the flexible section 31 and the tip section 35, and can be freely bent by wire operation from the control section 23 or by operating an actuator. This bending section 33 can be bent in any direction and at any angle depending on the part of the subject on which the endoscope 11 is used, and the observation direction of the irradiation ports 37A, 37B of the endoscope tip section 35 and the image sensor 21 can be directed to the desired observation area. Although not shown in the figure, cover glass or lenses are placed at the irradiation ports 37A, 37B of the endoscope insertion section 19.

[0015] The control device 13 includes a light source device 41 that generates illumination light supplied to the irradiation ports 37A and 37B of the endoscope tip 35, and a processor 43 that processes the image signal from the image sensor 21. The aforementioned display unit 15 and input unit 17 are connected to it. Based on instructions from the operation unit 23 and input unit 17 of the endoscope 11, the processor 43 processes the imaging signal transmitted from the endoscope 11 and generates and supplies a display image to the display unit 15.

[0016] Inside the endoscope 11, optical fibers 45A and 45B for introducing illumination light from the light source device 41, and a scope cable 47 connecting the image sensor 21 and the processor 43 are inserted. Although not shown in the figure, various signal lines from the control unit 23 and tubes such as air and water supply channels are also connected to the control device 13, etc., via the connector unit 25 through the universal cord unit 27. As shown in Figure 2, this connector 25 on the endoscope 11 is detachably connected to connector units 26A and 26B provided on the light source device 41 and the processor 43, respectively.

[0017] As shown in Figure 2, the light source device 41 is equipped with a blue laser light source (first light source) 51 with a central wavelength of 445 nm and a violet laser light source (second light source) 53 with a central wavelength of 405 nm as light sources. The light emitted from the semiconductor light-emitting elements of each of these light sources 51 and 53 is individually controlled by the light source control unit 55, and the ratio of the light intensity between the light emitted from the blue laser light source 51 and the light emitted from the violet laser light source 53 can be freely changed.

[0018] The first light source, a blue laser light source 51, and the second light source, a violet laser light source 53, can utilize broad-area InGaN-based laser diodes, and InGaNAs-based laser diodes or GaNAs-based laser diodes can also be used. Furthermore, the above light sources may also be configured using light-emitting elements such as light-emitting diodes.

[0019] The laser light emitted from each of these light sources 51 and 53 is input into an optical fiber via a focusing lens (not shown), and propagated through the connector section 26A and the connector 25 on the endoscope 11 side (see Figure 1) via optical fibers 45A and 45B to the endoscope tip 35 of the endoscope 11 (see Figure 1). The laser light from the blue laser light source 51 is irradiated onto a phosphor 57, which is a wavelength conversion member located at the endoscope tip 35, and the laser light from the purple laser light source 53 is irradiated onto a light deflection / diffusion member 59.

[0020] Optical fibers 45A and 45B are multimode fibers, and as an example, they can be used in small-diameter cables with a core diameter of 105 μm, a cladding diameter of 125 μm, and a diameter of φ0.3 to 0.5 mm including the outer protective layer.

[0021] The phosphor 57 is one of several types of phosphors (for example, YAG phosphors or BAM (BaMgAl)) that absorb a portion of the blue laser light from the blue laser light source 51 and emit green to yellow light when excited. 10 O 17 ) The device is composed of a phosphor (including, etc.). As a result, the green to yellow excitation light, which is generated from the blue laser light source 51, and the blue laser light that is not absorbed by the phosphor 57 and is transmitted, are combined to produce white (pseudo-white) illumination light. As in this example configuration, by using a semiconductor light-emitting element as the excitation light source, high-intensity white light can be obtained with high luminous efficiency, and the intensity of the white light can be easily adjusted. Moreover, the change in color temperature and chromaticity of the white light is reduced.

[0022] Furthermore, the blue laser light source 51, the phosphor 57, and the optical fiber 45A connecting them can be, for example, "MicroWhite" (product name) manufactured by Nichia Corporation.

[0023] Furthermore, the light deflection and diffusion member 59 can be made of any material that transmits laser light from the violet laser light source 53, such as a translucent resin material or glass. In addition, the light deflection and diffusion member 59 may be configured with a light diffusion layer on the surface of the resin material or glass, which contains minute irregularities or particles with different refractive indices (fillers, etc.), or it may be made of a semi-transparent material. As a result, the transmitted light emitted from the light deflection and diffusion member 59 becomes narrowband wavelength illumination light with a uniform light intensity within a predetermined irradiation area.

[0024] Furthermore, the phosphor 57 and the light deflection / diffusion member 59 can prevent phenomena such as the superposition of noise that hinders imaging and the occurrence of flicker when displaying moving images, which are caused by speckle resulting from the coherence of laser light. In addition, it is preferable that the phosphor 57 is composed of materials that have low absorption and high scattering for infrared light, taking into account the difference in refractive index between the fluorescent material constituting the phosphor and the fixing / solidification resin that serves as the filler. This enhances the scattering effect without reducing the light intensity for red and infrared light, eliminates the need for optical path changing means such as concave lenses, and reduces optical loss.

[0025] Figure 3 is a graph showing the emission spectra of laser light from the violet laser light source 53, blue laser light from the blue laser light source 51, and light after wavelength conversion of the blue laser light by the phosphor 57. The violet laser light from the violet laser light source 53 is represented by an emission line with a central wavelength of 405 nm (profile A). The blue laser light from the blue laser light source 51 is represented by an emission line with a central wavelength of 445 nm, and the excitation emission light from the phosphor 57 by the blue laser light has a spectral intensity distribution in which the emission intensity increases in the wavelength band of approximately 450 nm to 700 nm (profile B). The aforementioned white light is formed by this excitation emission light and profile B from the blue laser light.

[0026] Herein, the term "white light" as used herein is not limited to light that strictly includes all wavelength components of visible light, but rather includes light in specific wavelength bands such as R, G, and B. For example, it broadly includes light that includes wavelength components from green to red, or light that includes wavelength components from blue to green.

[0027] In other words, this endoscope device 100 generates illumination light by relatively increasing or decreasing the light emission intensity of profile A and profile B, so illumination light with different characteristics can be obtained depending on the mixing ratio of profiles A and B.

[0028] Let's return to Figure 2 for further explanation. As described above, the illumination light formed by the blue laser light source 51, the phosphor 57, and the purple laser light source 53 is irradiated from the tip of the endoscope 11 toward the area to be observed of the subject. The appearance of the area to be observed, illuminated by the illumination light, is then imaged onto the image sensor 21 by the imaging lens 61 and captured.

[0029] After imaging, the image signal output from the image sensor 21 is converted into a digital signal by the A / D converter 63 and input to the image processing unit 65 of the processor 43. The image processing unit 65 converts the input image signal into image data, performs appropriate image processing, and generates the desired output image information. The obtained image information is then displayed on the display unit 15 as an endoscopic observation image via the control unit 67. If necessary, it is also recorded in the recording device 69, which consists of memory and storage devices.

[0030] The recording device 69 may be built into the processor 43 or connected to the processor 43 via a network. The recording device 69 records information on the endoscopic observation image along with information on the light intensity ratio at the time of imaging. This allows for accurate interpretation of the recorded endoscopic observation image after endoscopic observation, and also enables appropriate image processing, such as standardizing the image according to the light intensity ratio, thereby expanding the range of applications for the endoscopic observation image. In particular, by estimating spectral reflectance by artificially increasing the number of bands (R, G, B) based on information from multiple images with different light intensity ratios, it becomes possible to separate even minute color differences.

[0031] Figure 4 shows a detailed block diagram of the image processing unit. The image signal from the image sensor 21, which is input to the image processing unit 65, is first input to the luminance calculation unit 65a. The luminance calculation unit 65a calculates luminance information such as the maximum luminance, minimum luminance, and screen average luminance of the image signal, and normalizes the luminance. If the luminance of the image signal is too low or too high, it outputs a correction signal to the light source control unit 55, which increases or decreases the light emission amount of each light source 51, 53 so that the image signal reaches the desired luminance level.

[0032] Next, the color matching unit 65b adjusts the normalized image data so that the color tone of the image becomes the desired color tone. For example, if the image signal consists of R, G, and B color signals, it adjusts the intensity balance of the R, G, and B color signals. In the light source device 41 described above, the light source control unit 55 controls the light emission amount of the blue laser light source 51 and the violet laser light source 53, respectively, so that the ratio of light intensity between the light emitted from the blue laser light source 51 and the light emitted from the violet laser light source 53 can be arbitrarily changed. Therefore, since the color tone and total illuminance of the illumination light may change depending on the set light intensity ratio, the luminance calculation unit 65a and the color matching unit 65b correct the image signal according to the set light intensity ratio to maintain the color tone and luminance of the observed image at a predetermined constant level.

[0033] Then, the image processing unit 65c performs predetermined or requested image calculations, and the display image generation unit 65d generates output image information based on the results and outputs it to the control unit 67.

[0034] Next, we will explain an example of using the above-described endoscopic device 100 to observe vascular images of the surface of biological tissue. Figure 5 is a schematic diagram illustrating the blood vessels in the mucosal surface of living tissue. The mucosal surface of living tissue is formed between the blood vessels B1 of the deep mucosa and the capillaries B2, such as the resinous vascular network, and it has been reported that lesions in living tissue manifest in the fine structures such as these capillaries B2. Therefore, in recent years, attempts have been made to use endoscopic devices to visualize and observe the capillaries in the mucosal surface using image enhancement with light of a specific narrow band to detect minute lesions early and diagnose the extent of lesions.

[0035] Incidentally, when illumination light is incident on biological tissue, the incident light propagates diffusively within the tissue. However, the absorption and scattering characteristics of biological tissue are wavelength-dependent, with shorter wavelengths tending to exhibit stronger scattering characteristics. In other words, the depth of light penetration changes depending on the wavelength of the illumination light. On the other hand, blood flowing through blood vessels has a maximum absorption at wavelengths around 400-420 nm, providing a high contrast. For example, in the wavelength range λa, where the illumination light is around 400 nm, vascular information from capillaries on the mucosal surface can be obtained, while in the wavelength range λb, where the illumination light is around 500 nm, vascular information including deeper blood vessels can be obtained. Therefore, for observing blood vessels on the surface of biological tissue, a light source with a central wavelength of 360-800 nm, preferably 365-515 nm, and more preferably 400-470 nm, is used.

[0036] Therefore, as shown in Figure 6, which illustrates a schematic display of observation images obtained with an endoscope, when the illumination light is white light, a relatively deep view of blood vessels in the mucosa can be obtained, while the fine capillaries in the mucosal surface appear blurred. On the other hand, when the illumination light is narrowed to short wavelengths only, the fine capillaries in the mucosal surface become clearly visible in the observation image.

[0037] In this configuration example, the light source control unit 55 (see Figure 2) of the endoscope device 100 allows for the adjustment of the light intensity ratio between the blue laser light source 51 with a central wavelength of 445 nm and the violet laser light source 53 with a central wavelength of 405 nm. The light intensity ratio can be changed, for example, by operating a switch 89 on the operation unit 23 of the endoscope 11 shown in Figure 1, thereby enhancing the image to make it easier to observe the capillaries on the surface of the mucosa. In other words, when the blue laser light component from the blue laser light source 51 is high, the illumination light becomes high in white light component from this blue laser light and the excitation emission light from the phosphor 57, resulting in an observation image like the white light observation image in Figure 6. However, since the narrowband blue laser light is mixed in with the illumination light, the observation image will be enhanced to highlight the capillaries on the surface.

[0038] Furthermore, when there is a large amount of purple laser light component from the purple laser light source 53, an observation image like the narrowband light observation image in Figure 6 can be obtained. By increasing or decreasing the ratio of the light intensity of the emitted light from the blue laser light source 51 and the purple laser light source 53, that is, by increasing or decreasing the ratio of the purple laser light component to the total illumination light component, it is possible to continuously highlight and observe the fine capillaries on the surface of the mucous membrane.

[0039] Therefore, the greater the amount of purple laser light component, the more clearly the fine capillaries contained in the thin depth region of the mucosal surface are displayed in the observed image. Conversely, as the amount of purple laser light component decreases, vascular information in a wider depth region from the mucosal surface to the deeper layers is displayed. This allows for a simulated display of the vascular distribution from the mucosal surface to the depth direction, and vascular information in the depth direction of the observed area can be extracted as continuous information corresponding to each depth range. In particular, in this configuration example, vascular information obtained with blue laser light and vascular information from even more superficial layers obtained with purple laser light are both extracted, and since both can be compared by displaying this information in images, vascular information including more superficial blood vessels that could not be observed with blue laser light can be observed with improved visibility.

[0040] Furthermore, at the tip 35 of the electronic endoscope (see Figure 1) where the image sensor 21 is located, the amount of heat generated has increased along with the increase in power consumption due to recent advancements in pixel count and frame rate, and the amount of light that can be emitted from the tip 35 is also limited. In this context, changing the light intensity ratio of each light source, while suppressing the total amount of illumination light, can increase the required light emission, thus resolving problems such as relying solely on image processing and consequently obtaining only noisy images.

[0041] Figures 7a, 7b, and 7c show magnified images of the inside of the lip observed with the same light intensity and under similar image processing conditions using the endoscope device 100. These figures show observation images with white illumination consisting of a blue laser light with a central wavelength of 445 nm and excitation emission light from a phosphor (Figure 7a), observation images when the light intensity ratio of a violet laser light with a central wavelength of 405 nm and a blue laser light with a central wavelength of 445 nm is 50:50 (Figure 7b), and observation images when the light intensity ratio of a violet laser light with a central wavelength of 405 nm and a blue laser light with a central wavelength of 445 nm is 75:25 (Figure 7c). In Figures 7b and 7c, the excitation emission light from a phosphor excited by a blue laser light with a central wavelength of 445 nm is also included in the illumination light.

[0042] The observation images in Figure 7 show that the observation depth from the surface becomes shallower in the order a→b→c depending on the wavelength of the illumination light, and the amount of fine capillaries visualized increases. In other words, the more the proportion of violet laser light in the illumination light is increased, the more emphasized the capillaries on the surface are obtained, allowing for clearer observation of the capillaries and fine mucosal patterns on the mucosal surface with increased contrast. Furthermore, since the ratio of blue laser light to violet laser light can be freely changed steplessly, it is easy to infer the three-dimensional vascular structure on the mucosal surface from the changes in the observation image when the light intensity ratio is continuously changed, or to selectively visualize desired observation targets with greater clarity.

[0043] For violet and blue light, which have wavelength bands that are close to each other, it is difficult to increase or decrease the light intensity of only the violet region separately from the blue region using conventional halogen lamps or xenon lamps and wavelength limiting means such as color filters. If the emission spectrum is narrowed using wavelength limiting means in the optical path, the amount of light in the violet region becomes even more insufficient, in addition to the already low light intensity of the halogen lamp or xenon lamp itself. Furthermore, if one tries to widen the full width at half maximum of the emission spectrum to increase the light intensity in the violet region, it is not possible to narrow the bandwidth of the illumination light, resulting in insufficient image enhancement of the desired blood vessels.

[0044] When the illumination light intensity is insufficient, it can generally be addressed by increasing the sensitivity of the image sensor or decreasing the frame rate. However, increasing the sensitivity of the image sensor during imaging has the disadvantage of increasing the noise component of the captured image. Also, decreasing the frame rate and increasing the sensitivity increases blurring, making the observation image harder to see. In this configuration example, since laser light is used as the light source, high-intensity illumination light can be obtained stably at all times, making the observation image bright and producing good image quality with low noise. Furthermore, sufficient illumination can be obtained even when imaging distant landscapes.

[0045] The above light intensity ratio is changed by the light source control unit 55 shown in Figure 2, which controls each light source 51 and 53. Next, we will explain how the operator can change this light intensity ratio while viewing the observed image, using Figures 8 and 9. Figure 8 shows an example of the display screen 71 of the display unit 15 that displays observation images from the endoscope device 100. The display screen 71 is provided with an endoscope image area 73 for displaying observation images from the endoscope device, a normal image switching button 75 for displaying observation images with normal white light illumination in the endoscope image area 73, and a narrow-band light image switching button 77 for displaying observation images with narrow-band illumination of purple laser light. Furthermore, an adjustment bar 79 and a knob 81 are provided for adjusting the light intensity ratio. Based on instructions from an input unit 17 such as a mouse or keyboard, the knob 81 is slid within the adjustment bar 79 to adjust the light intensity ratio to obtain the desired observation image.

[0046] The control unit 67 determines the light intensity ratio according to the position of the knob 81 on the adjustment bar 79, and drives each light source 51, 53 to produce the light intensity corresponding to this light intensity ratio. Here, the relationship between the light intensity ratio and the light intensity of each light source 51, 53 is stored in the storage unit 83 (see Figure 2) as a light intensity ratio correspondence table, and the control unit 67 determines the light intensity of each light source 51, 53 by referring to the light intensity ratio correspondence table in the storage unit 83.

[0047] As described above, when increasing or decreasing the light intensity of each light source 51, 53 (see Figure 1) to set the desired light intensity ratio, the control unit 67 determines the emitted light intensity of each light source 51, 53 by referring to a pre-stored light intensity ratio correspondence table based on the light intensity ratio set on the display screen 71. This allows the operator of the endoscope to set the emitted light intensity of each light source 51, 53 to the desired light intensity ratio with simple operation, without having to directly set it themselves.

[0048] Furthermore, as shown in Figure 9, the change in light intensity ratio may be set by using the setting unit 85 for adjusting the intensity balance, brightness, and contrast of the R, G, and B color components of the image signal, or it may be used in combination with adjusting the knob 81 for changing the light intensity ratio. This allows for arbitrary image enhancement, such as representing a desired observation target in pseudo-color, improving the flexibility of changing the displayed image and making it easier to diagnose.

[0049] Next, the method by which the light source control unit 55 drives each of the light sources 51 and 53 will be described. The light source control unit 55 shown in Figure 2 controls the amount of light emitted from each light source 51 and 53 based on instructions from the input unit 17. Each light source 51 and 53 has a relationship R1 between the applied current and the amount of light emitted, as shown in Figure 10, and the desired amount of light emitted is obtained by controlling the current applied to each light source 51 and 53. For example, to obtain the amount of light emitted La, the applied current is set to Ib to secure the amount of light emitted Lb based on the relationship R1, and further, the difference ΔL between the amount of light emitted Lb and La, which serves as a fine adjustment margin, is obtained by superimposing a pulse-modulated pulse current onto the applied current.

[0050] For example, as shown in Figure 11, which illustrates the pulsed current superimposed waveform of the applied current, the amount of light emitted La is obtained by a pulsed current biased by the applied current Ib. By controlling the bias current and pulse modulation in this way, a wide dynamic range of the configurable amount of light emitted can be ensured.

[0051] In this case, various drive waveforms can be used for pulse modulation control. For example, using a pulse waveform that repeatedly switches on and off in sync with the light accumulation time for one image frame of the image sensor, as shown in Figure 12(a), reduces the influence of dark current in the CCD and CMOS image sensors, and improves image sharpness. Furthermore, using a pulse waveform with a sufficiently fast period relative to the aforementioned light accumulation time, as shown in Figure 12(b), can reduce the occurrence of flicker related to image display, and also reduce image noise caused by laser speckle. Moreover, using a mixed pulse waveform of (a) and (b), as shown in Figure 12(c), where the on period of the pulse waveform in Figure 12(a) is the fast-period pulse waveform in Figure 12(b), allows for the enjoyment of the above effects in addition to flicker reduction.

[0052] Furthermore, as shown in Figure 13, by alternately lighting each light source 51 and 53 and controlling them so that the light emission amount alternately reaches its maximum, the maximum driving power of the light source device 41, which combines light sources 51 and 53, can be reduced, thereby reducing the burden on the living body of the subject. In addition, it is possible to acquire images captured by the illumination light from each light source 51 and 53 individually, and in that case, inter-image calculations of the acquired images become possible, improving the flexibility of image processing.

[0053] Figure 14 shows a schematic relationship between the absorption wavelength band of hemoglobin and the emission wavelengths of each light source 51 and 53. As mentioned above, hemoglobin in the blood has a maximum absorption at wavelengths around 400-420 nm. Light emitted from each light source 51 and 53, whose emission wavelengths are within or close to the hemoglobin absorption wavelength band, can capture vascular information with high contrast. Furthermore, by setting the emission wavelengths of each light source 51 and 53 to have roughly the same absorption rate, straddling the hemoglobin absorption wavelength band, the intensity of vascular information is not affected by the light intensity ratio of each light source 51 and 53. In other words, even if the light intensity ratio of each light source 51 and 53 is changed, the detection sensitivity of the vascular image itself remains constant.

[0054] Furthermore, by using light in a wavelength range that avoids the maximum peak wavelength of the hemoglobin absorption wavelength band and has an appropriate absorption rate in the lower end of the absorption wavelength band as illumination light, it is possible to prevent the observed image from becoming dark due to absorption by blood seeping into the tissue surface layer when bleeding occurs from biological tissue in the observed area.

[0055] The observation images obtained by illumination with the narrowband light of the purple laser described above and illumination with white light can be switched instantaneously frame by frame. Figure 15 schematically shows the display image on the display unit 15 (see Figures 1 and 2) when the endoscopist moves the endoscope insertion part within the subject, performs observation with narrowband light at the desired observation position, and then moves to the next position.

[0056] Switching from a normal display image using white light observation to a display image using narrowband light observation, and vice versa, is possible on a frame-by-frame basis for the image captured by the image sensor 21 (a full-color image using three colors: R, G, and B). Therefore, even when observing while moving the endoscope insertion section, a color-shift-free image can be displayed in real time, without causing discomfort to the operator. In other words, it is possible to provide a good observation image that reliably follows the rapid movement of the endoscope, thereby improving the operability of the endoscope device.

[0057] Furthermore, the display pattern of the observation image in the display unit 15 can be freely arranged to show both the normal image when observing with white light and the narrowband light image when observing with narrowband light. For example, as shown in Figure 16, by arranging the normal image and the narrowband light image in separate areas on the same screen and displaying them simultaneously, it becomes easy to compare and observe the normal image with the narrowband light image in which specific information is emphasized. In this case, the blue laser light source 51 is turned on to capture the normal image using white light, and in the next frame, the blue laser light source 51 and the purple laser light source 53 are turned on simultaneously to capture the narrowband light image, and this process is repeated, with the obtained normal image and narrowband light image being displayed in their respective display areas.

[0058] Figure 17 also shows the display screen of the so-called P in P (Picture in Picture) function, which overlays a narrowband optical image of a desired range onto a normal image and displays them simultaneously. The display range of the narrowband optical image can be set to any position and size within the normal image by instructions from the input unit 17 (see Figures 1 and 2). Within the display range of the narrowband optical image, an image is displayed at the same position as the subject in the normal image. This makes comparative observation at the same position even easier. It should be noted that the above display pattern is just one example, and it is also possible to embed a normal image within a narrowband optical image, and other arbitrary combinations of displays can be performed.

[0059] Next, we will explain how to set the ratio of blue laser light to violet laser light. In the above explanation, it was stated that the light intensity ratio of the light emitted from the blue laser light source 51 and the violet laser light source 53 shown in Figure 2 can be arbitrarily set by the light source control unit 55 based on instructions from the input unit 17. Here, we will explain the case where multiple light intensity ratios are registered in advance, and one of the light intensity ratios is specified from the input unit 17.

[0060] For example, in endoscopic observation of vascular images, the preferred ratio of blue laser light to violet laser light may differ among endoscopists. For instance, operator A may prefer an observation image with a violet laser light λa and blue laser light λb ratio of 60:40, while operator B may prefer a ratio of 75:25. In such cases, as shown in Figure 18, light intensity ratio information, which associates the operator's name (key information) with the operator's preferred light intensity ratio, is pre-registered as a light intensity ratio table in the memory unit 83 (see Figure 2). When information corresponding to the operator's name is input from the input unit 17, the control unit 67 automatically sets the desired light intensity ratio by referring to the light intensity ratio table in the memory unit 83. This allows the light intensity ratio to be set according to the endoscopist's preference.

[0061] Furthermore, since the optical characteristics may differ depending on the individual endoscope, the operator's name used as the key information above may be replaced with individual identification information that identifies the endoscope itself. In that case, the number, model name, etc., assigned to each individual endoscope is used, and the corresponding light intensity ratio information is registered in advance as a light intensity ratio table. This allows the optimal light intensity ratio to be set according to the type and characteristics of each individual endoscope.

[0062] Furthermore, the system may be configured to allow multiple types of light intensity ratios to be preset, enabling the operator to freely select them with simple operations. For example, as shown in Figure 19, an example of display by the display unit 15 is shown, where multiple preset light intensity ratios are displayed as "selection buttons" 87 on the GUI (Graphical User Interface), allowing the operator or assistant to freely select them by looking at the display unit 15 (see Figures 1 and 2) and operating the input unit 17. If the display unit 15 is a touch panel, the operator can directly touch the selection buttons 87 on the display unit 15, which they are focusing on during observation, allowing for more intuitive and quick switch operation. In addition, the operator can compare each observation image that changes due to the change in light intensity ratio without taking their eyes off it, enabling them to more reliably recognize subtle image changes.

[0063] Furthermore, the switching of the light intensity ratio is not limited to the display pattern on the display unit 15; it may also be configured to be operated using a switch 89 provided on the operation unit 23 of the endoscope 11, as shown in Figure 1. By providing a switch 89 on the operation unit 23, the operator can quickly and easily change the light intensity ratio without taking their hands off the endoscope 11, thereby improving the operability of the endoscope.

[0064] Various types of switches can be used for this switch 89, such as toggle switches, push switches, slide switches, and rotary switches. As shown in Figure 20, different preset light intensity ratios are sequentially set with each press operation or depending on the contact position of a multi-contact switch. For example, it is possible to sequentially select observation light modes with multiple light intensity ratios, such as normal light observation using white light from the blue laser light source 51 and phosphor 57 as shown in Figure 2, narrowband light observation A, B, C, ... in which narrowband light from the purple laser light source 53 is superimposed on the white light at a predetermined ratio, or narrowband light observation using only narrowband light.

[0065] If the switch operation is a repetitive pressing operation, there is no need to visually confirm the switch 89, and the switch can be operated while keeping an eye on the display unit 15. This makes it easy to switch to illumination light suitable for diagnosis. The switch 89 for switching the light intensity ratio is not limited to switching between preset light intensity ratios, but may also be a volume switch or slide switch that continuously changes the light intensity ratio. In that case, it becomes easy to optimally adjust the light intensity ratio according to the object being observed. Furthermore, by continuously changing the light intensity ratio by operating the switch, it is possible to observe continuous changes in the observed image, enabling a more accurate understanding of the vascular structure.

[0066] Next, we will explain how to correct the color changes in the observed image that occur due to changes in the light intensity ratio. Image processing unit 65, shown in Figure 4, receives image signals R, G, and B. These image signals R, G, and B are normalized by the luminance calculation unit 65a and converted into image data of Rnorm, Gnorm, and Bnorm. These normalized image data Rnorm, Gnorm, and Bnorm are then corrected to a color tone according to the light intensity ratio by the color matching unit 65b. That is, the color matching unit 65b obtains the image data Radj, Gadj, and Badj after color tone correction by the calculation shown in equation (1).

[0067]

number

[0068] Here, k R , k G , k B These are the color conversion coefficients for each color, which were set during imaging. It is determined according to the light intensity ratio. Figure 21 shows a color conversion coefficient table that defines the color conversion coefficient for each color corresponding to the light intensity ratio. Color conversion coefficient k R , k G , k B Each corresponds to the respective light intensity ratio, R The values ​​are set as 00~R100, G00~G100, and B00~B100, and are stored in the memory unit 83 (see Figure 2). By substituting the color conversion coefficients corresponding to the light intensity ratio used during imaging into equation (1), color-corrected image data Radj, Gadj, and Badj are obtained.

[0069] These color conversion coefficients are not limited to being represented as a table as shown in Figure 21; they may also be expressed as mathematical formulas, or only the representative points may be quantified and the other points may be obtained by interpolation. In that case, the amount of information stored in the memory unit 83 can be reduced.

[0070] As described above, with the endoscopic device 100, by using violet laser light (and blue laser light), that is, illumination light in a short wavelength band particularly suitable for observing blood vessels, it is possible to observe microvessels on the surface of biological tissue with enhanced imagery, making it easier to observe the fine structure of blood vessels. Furthermore, since the ratio of the emitted light intensity of violet laser light and blue laser light (white light) can be continuously changed, it is possible to easily observe the vascular structure that changes from the surface of biological tissue to the depth direction, and the vascular structure in the more superficial parts of biological tissue can be clearly grasped. Therefore, when observing biological tissue with white light or special light, desired tissue information of the biological tissue can be obtained in a clearer state suitable for diagnosis, and endoscopic diagnosis can be performed smoothly.

[0071] Furthermore, if the above-mentioned endoscope device 100 is configured as a so-called magnifying endoscope, equipped with an imaging optical system that allows for magnified observation of the observed area, the separation between microvessels and mucosal fine patterns on the surface of biological tissue can be improved, enabling more advanced endoscopic diagnosis. In other words, magnified observation allows for the confirmation of abnormalities such as variations in the diameter, uneven shape, dilation, and tortuosity of microvessels, as well as abnormalities such as the disappearance or irregular miniaturization of mucosal fine patterns, providing useful information, such as for diagnosing the type of adenocarcinoma.

[0072] Next, we will describe other examples of endoscopic device configurations. First, I will explain an endoscopic device that uses the difference in absorption characteristics between hemoglobin and oxyhemoglobin to determine the oxygen concentration distribution in the blood within the observed image. Figure 22 shows the absorption spectra of low-oxygen hemoglobin (Hb) and oxygen-saturated oxyhemoglobin (HbO2) at wavelengths of 450 nm to 700 nm. For observation, the illumination light was: The wavelength λ of the isosbestic point where the absorption of hemoglobin (Hb) and oxyhemoglobin (HbO2) is equal. By selecting wavelength 1 and wavelength λ2, which have different absorption rates, we determine the brightness Ab1 of the observed image with illumination light of wavelength λ1 and the brightness Ab2 of the observed image with illumination light of wavelength λ2.

[0073] The ratio of brightness levels Ab1 and Ab2 in these images serves as an indicator of oxygen concentration in the blood, allowing for monitoring of changes in the metabolic state of biological tissues. Generally, cancerous areas are said to have low oxygen concentrations, making oxygen concentration useful information for endoscopic diagnosis.

[0074] As a configuration of the endoscope apparatus for obtaining the above oxygen concentration distribution, as shown in the configuration examples of the light source device 41 and the endoscope 11 in FIG. 23, in the endoscope apparatus 200, a plurality of light sources are added to the light source device 41. Here, as the illumination light for the equal absorption point, for example, blue-green laser light from a blue-green laser light source 91 with a central wavelength of 515 nm is used, and as the illumination light with different absorption wavelengths, red laser light from a red laser light source 93 with a central wavelength of 630 nm is used. Of course, when mainly measuring the oxygen concentration distribution, the purple laser light source 53 can also be omitted. Note that the same reference numerals are given to the same members as those in FIG. 2, and the description thereof is omitted.

[0075] In addition, it is preferable to select and use the most suitable optical fibers for the optical fibers 45A, 45B, 45C, and 45D having the above configuration according to the wavelengths to be used. The core of the optical fiber has a wavelength dependence in which the transmission loss changes depending on the high / low concentration of the hydroxyl group (OH - ), and at specific wavelengths in the infrared region, it has an absorption rate different from that of the wavelengths in the visible region. Therefore, when the wavelength of the light source is 650 nm or less, an optical fiber with a core of high hydroxyl group concentration is used, and when it exceeds 650 nm, an optical fiber with a core of low hydroxyl group concentration is used.

[0076] To obtain the oxygen concentration distribution, first, the observation region is imaged using the blue-green laser light from the blue-green laser light source 91 as the illumination light, and then the observation region is imaged using the red laser light from the red laser light source 93 as the illumination light. At the time of imaging, the emission light amounts of each of the light sources 91 and 93 are adjusted so that the average luminance value etc. of the observation image data becomes constant. Then, from the luminances Ab1 and Ab2 of each of the obtained observation images, the oxygen concentration index Oindx is obtained for each pixel by the formula (2). Oindx = k·(Ab2 / Ab1) ···(2) However, k is a coefficient.

[0077] Thereby, a distribution image of the oxygen concentration index Oindx is obtained, and the distribution state of the oxygen concentration in the observation image can be grasped.

[0078] Furthermore, the light intensity of the blue-green laser light source 91 and the red laser light source 93 can be individually changed by the light source control unit 55, similar to the blue laser light source 51 and the violet laser light source 53, and the ratio of the light intensity of each emitted light can be adjusted according to the object of observation and the content of the procedure. In addition, each laser light source 91 and 93 may be emitted within one frame of the imaging signal, and their light intensity ratio may be adjusted as appropriate. The blue-green laser light is suitable for observing microvessels and redness in biological tissue, and the red laser light is suitable for observing deep blood vessels in biological tissue. Therefore, by changing the ratio of the light intensity of the emitted light from each of these lasers, as described above, information from different regions in the depth direction and information from different objects can be displayed with image enhancement.

[0079] Furthermore, even if each light source is emitted simultaneously within one frame of the imaging signal, the optical component from the blue-green laser light source 91, the optical component from the red laser light source 93, or the excitation light amount can be separated and detected from the R, G, and B image signals output from the image sensor 21.

[0080] In this way, by making it possible to arbitrarily and continuously change the light intensity ratio of blue-green laser light to white light, the light intensity ratio of red laser light to white light, or the light intensity ratio of blue-green laser light and red laser light, the visibility of the desired observation target can be enhanced and displayed. Furthermore, by increasing the types of illumination light available for the endoscope and making it more multifunctional, even if the need for unexpected observation arises during endoscopic diagnosis, it becomes possible to quickly observe the target with appropriate illumination light without removing the endoscope from the patient. In addition, instead of generating white light with blue laser light and excitation emission light from a phosphor, it is also possible to use a white light source such as a halogen lamp. In that case, the light intensity of the blue laser light and the light intensity of the white light can be controlled individually, allowing for more precise adjustment of the light intensity ratio.

[0081] Next, we will describe an endoscope device in which the optical path from the light source device 41 to the endoscope 11 is made up of a single optical fiber 45. Figure 24 shows an example configuration of the light source device 41 and the endoscope 11. The endoscope device 300 is equipped with a dichroic prism 95 as an optical coupling means that merges the blue laser light from the blue laser light source 51 with a central wavelength of 445 nm with the purple laser light from the purple laser light source 53 with a central wavelength of 405 nm in the optical path from the blue laser light source 51 with a central wavelength of 445 nm to the optical fiber 45A via a focusing lens (not shown).

[0082] The phosphor 97, positioned on the light-emitting side of the optical fiber 45A, absorbs a portion of the blue laser light from the blue laser light source 51, exciting and emitting green to yellow light. This light, combined with the unabsorbed and transmitted blue laser light, forms white light. It also transmits purple laser light from the purple laser light source 53 with almost no absorption. Therefore, the phosphor 97 is selected from materials that are highly excited and emit light with blue laser light, forming white light in combination with the blue laser light, and materials that emit less light with respect to purple laser light.

[0083] Wavelength conversion using phosphor 97 inherently involves wavelength conversion losses (Stokes loss), such as heat generation. Therefore, it is known that selecting an excitation wavelength with a longer emission wavelength increases the luminescence efficiency of the phosphor and is advantageous in suppressing heat generation. Accordingly, in this configuration example, white light is generated by long-wavelength laser light to increase luminescence efficiency.

[0084] Figure 25 shows an example of the emission spectrum of illumination light from the light source device 41 and phosphor 97 shown in Figure 24. As shown in Figure 25, it is desirable that the excitation emission amount of the phosphor 97 by violet laser light be a fraction of the excitation emission amount by blue laser light (at least 1 / 3, preferably 1 / 5, and even more preferably 1 / 10 or less).

[0085] As described above, with this configuration, the optical paths of the blue laser light and the violet laser light are integrated by the dichroic prism 95, and the light is guided from the light source device 41 to the phosphor 97 by a single optical fiber 45A. Furthermore, the illumination light output port can be located in one place on the phosphor 97, thus improving space efficiency and contributing to a reduction in the diameter of the endoscope insertion section.

[0086] Furthermore, even if other laser light sources are provided in addition to the blue laser light source 51 and the violet laser light source 53, the optical paths can be similarly integrated via optical coupling means such as a dichroic prism. Also, for the phosphor 97, a fluorescent material that does not get excited, or is not easily excited, at the wavelengths of the other laser light sources can be used.

[0087] Here, as a specific example of the phosphor 97 material in this configuration, for example, a crystalline solid fluorescent material containing lead (Pb) as an additive element and based on gallium-2-gallium tetrasulfide (CaGa2S4), as described in Japanese Patent Application Publication No. 2006-2115, or as an additive element It contains lead (Pb) and cerium (Ce) and is made of gallium-2-gallium sulfide calcium (CaGa2S4). A crystalline solid-state fluorescent material can be used as the base material. This phosphor material allows for fluorescence to be obtained across almost the entire visible spectrum from approximately 460 nm to approximately 660 nm, improving color rendering under white light illumination.

[0088] In addition, there is also the green phosphor LiTbW2O8 (Tsutomu Odaki, "For white LEDs") Regarding phosphors, see IEICE Technical Report ED2005-28, CFM2005-20, SDM2005-28, pp.69-74 (2005-05), etc.), beta-sialon (β-sialon:Eu) blue phosphor (see Naoto Hirosaki, Eijun Kai, Ken Sakuma, "Development of sialon-based phosphors and white LEDs using them," Journal of the Japan Society of Applied Physics, Vol. 74, No. 11, pp.1449-1452 (2005), or Akira Yamamoto, Faculty of Bionics, Tokyo University of Technology, Journal of the Japan Society of Applied Physics, Vol. 76, No. 3, p.241 (2007)), CaAlSiN3 red phosphor, etc. can be used in combination. Aron is a β-type silicon nitride crystal in which aluminum and acid are solidly dissolved. 6-z Al2O2N 8-z ( The crystal is represented by the composition (where z is the solid solution amount). The phosphor 97 is composed of these LiTbW2O8 and It is also acceptable to use a mixture of t-sialon and CaAlSiN3, and these fluorescence The structure may also be composed of layers of bodies stacked on top of each other.

[0089] Each of the phosphors exemplified above is excited by blue laser light from the blue laser light source 51, and does not emit light when excited by violet laser light from the other violet laser light source 53. In other words, the emission wavelengths of other light sources are not included in the phosphor's primary excitation wavelength band.

[0090] In the endoscopic device described above, white light was generated by blue laser light and the excitation emission light of phosphors 57 and 97. However, this is not the only way to generate white light. For example, a configuration using a phosphor that generates green excitation emission light with blue laser light and a phosphor that generates red excitation emission light with violet laser light is possible. Various combinations of light sources and phosphors are possible for generating white light.

[0091] Thus, the present invention is not limited to the embodiments described above, and modifications and applications by those skilled in the art based on the description in the specification and well-known art are also intended and within the scope of protection sought.

[0092] As described above, the following matters are disclosed in this specification: (1) An endoscopic illumination device that obtains illumination light using light emitted from multiple light sources, A first light source using a semiconductor light-emitting element as the light source, A second light source that uses a semiconductor light-emitting element with a different emission wavelength than the first light source, A wavelength conversion member that emits light excited by light emitted from at least one of the first and second light sources, A light intensity ratio changing means for changing the light intensity ratio between the light emitted from the first light source and the light emitted from the second light source, An endoscopic lighting device equipped with [specific features / features]. This endoscopic illumination device allows for the adjustment of the light intensity ratio between the first and second light sources. This enables the generation of illumination with a higher proportion of light emitted from the first light source, illumination with a higher proportion of light emitted from the second light source, and illumination with an intermediate proportion. Therefore, it is possible to provide illumination suitable for diagnosis according to the absorption and scattering characteristics of the biological tissue, and to acquire desired tissue information of the biological tissue in a clearer state.

[0093] (2) Endoscope lighting device of (1), An endoscopic illumination device in which the emission wavelength of at least one of the first and second light sources, a semiconductor light-emitting element, is included in the range of 400 nm to 470 nm. This endoscopic illumination device uses light from semiconductor light-emitting elements in the 400nm to 470nm range, allowing for enhanced observation of blood vessels, particularly in the superficial layers of biological tissue.

[0094] (3) An endoscopic illumination device according to (1) or (2), The wavelength conversion member is a phosphor that generates white light through the emission light emitted by the wavelength conversion member in response to excitation light and the light emitted from at least one of the first and second light sources. This endoscopic illumination device generates white light through the emission of light from a wavelength conversion component, which is excited by light from a semiconductor light-emitting element. As a result, high-intensity white light can be obtained with high luminous efficiency. Furthermore, because a semiconductor light-emitting element is used as the excitation light source, the intensity of the white light can be easily adjusted, and there is little change in the color temperature and chromaticity of the white light.

[0095] (4) An endoscopic illumination device of any of (1) to (3), An endoscope illumination device further comprising at least one third light source, each light source having a different emission wavelength, which is a semiconductor light-emitting element having a different emission wavelength than the first and second light sources. This endoscopic illumination device allows for the expansion of the illumination wavelength range by incorporating a third light source with a different emission wavelength, thereby improving the flexibility of wavelength selection. This makes it possible to obtain illumination light for various image formation purposes, such as vascular enhancement images using violet or blue light, and oxygen concentration distribution images using green and red light.

[0096] (5) An endoscopic illumination device of any of (1) to (4), An endoscopic illumination device comprising an optical coupling means arranged in the optical path from the first light source to the wavelength conversion member, which guides at least the light emitted from the second light source together with the light emitted from the first light source to the wavelength conversion member. This endoscopic illumination device requires only a single optical path from the optical coupling means to the wavelength conversion member, allowing for a simpler configuration with improved space efficiency when integrating the endoscopic illumination device into the endoscope.

[0097] (6) An endoscopic illumination device of any of (2) to (5), An endoscopic illumination device in which the emission wavelengths of the first light source and the second light source are set such that one is on the shorter wavelength side, straddling the maximum peak wavelength of the hemoglobin absorption wavelength band, and the other is on the longer wavelength side. This endoscopic illumination device allows for high-contrast capture of vascular information. Furthermore, by reducing the illumination light component near the maximum absorption wavelength of hemoglobin, it prevents the observed image from becoming dark due to absorption by blood seeping into the tissue surface layer.

[0098] (7) An endoscopic illumination device of any of (1) to (6), The light intensity ratio changing means independently changes the light intensity of the light emitted from each of the light sources in an endoscopic illumination device. This endoscopic illumination device allows for greater flexibility in adjusting the spectral characteristics of the illumination light ultimately formed by each light source, by freely changing the amount of light emitted from each light source.

[0099] (8) An endoscopic illumination device of any of (1) to (7), The system further includes an input means into which light intensity ratio information specifying a desired light intensity ratio is input, An endoscope illumination device in which the light intensity ratio changing means determines the amount of light emitted from each of the light sources to obtain the desired light intensity ratio based on the light intensity ratio information input to the input means. With this endoscopic illumination device, the light intensity ratio is specified based on the light intensity ratio information input from the input means, and the amount of light emitted from the light source is determined to achieve this light intensity ratio. In other words, the light intensity ratio can be freely changed as specified.

[0100] (9) An endoscopic illumination device of (8), The system further includes a storage means that stores a light intensity ratio table relating multiple types of light intensity ratios to key information, The aforementioned light intensity ratio information includes the aforementioned key information, An endoscopic illumination device in which the light intensity ratio changing means determines the desired light intensity ratio by referring to the light intensity ratio table based on key information contained in the light intensity ratio information input from the input means. With this endoscopic illumination device, the desired light intensity ratio is determined by referring to a light intensity ratio table based on key information contained in the light intensity ratio information. In other words, by pre-registering light intensity ratios for each key information in the light intensity ratio table, the light intensity ratio corresponding to that key information is automatically determined simply by specifying the key information.

[0101] (10) An endoscopic lighting device of (9), The aforementioned key information is the identification information of the operator of the endoscope, in the endoscopic lighting device. This endoscopic illumination device allows the light intensity ratio to be set to any desired level for each endoscopist, according to their preferences.

[0102] (11) An endoscopic lighting device of (9), The aforementioned key information is the individual identification information of the endoscope device, which is used for the endoscopic lighting device. This endoscopic illumination device allows for setting the light intensity ratio for each individual endoscope, according to its specific type and characteristics.

[0103] (12) An endoscopic illumination device of any of (9) to (11), An endoscope illumination device in which the input means is a toggle switch that selects one of several light intensity ratios set in the light intensity ratio table. This endoscopic illumination device allows users to arbitrarily select a desired light intensity ratio from several options by operating a switch, enabling quick and easy switching of light intensity ratios.

[0104] (13) An illumination means that emits illumination light from any of the endoscopic illumination devices described in (1) to (12) from the tip side of the endoscope insertion section inserted into the body cavity, An imaging sensor for capturing an image of the observed area illuminated by the aforementioned illumination light is mounted in the endoscope insertion section, and an imaging means for outputting an image signal that constitutes the observed image is provided. An endoscope equipped with [a specific feature / equipment]. This endoscopic device illuminates the area to be observed with illumination light set to a desired ratio of light intensity from the first and second light sources. By imaging this area with an image sensor, an observation image corresponding to the light intensity ratio is obtained. In other words, it is possible to illuminate the area with illumination light suitable for diagnosis and to acquire desired tissue information of living tissue in a clearer state.

[0105] (14) The endoscopic device of (13), An endoscope device comprising light source control means for causing at least the first light source and the second light source to emit light within one frame of the image signal of the image sensor. This endoscopic illumination device allows for the emission of light from multiple light sources within a single image signal frame and captured by the image sensor, thereby obtaining an observation image in which the light emitted from multiple light sources simultaneously illuminates the area being observed.

[0106] (15) The endoscopic device of (14), An endoscope device in which the light source control means causes at least the first light source and the second light source to emit light at different timings within one frame of the image signal of the image sensor. This endoscopic device eliminates the need to simultaneously emit light from each light source, thereby reducing the burden on the patient and lowering the device's power consumption.

[0107] (16) An endoscopic device of any of (13) to (15), Image processing means for generating a display observation image based on the image signal output from the image sensor, A display means for displaying information including the aforementioned observation image, An endoscope equipped with [a specific feature / equipment]. This endoscopic device allows for easier confirmation of observed images by displaying image signal information from the image sensor on a display device, enabling smoother endoscopic diagnosis.

[0108] (17) The endoscopic device of (16), The display means captures first image information under visible light including the light emitted from the first light source and the excitation light emitted from the wavelength conversion member, An endoscope device that simultaneously displays, on the same screen, second image information captured under illumination light including the light emitted from the second light source in addition to the visible light. This endoscope device simultaneously displays, on the same screen of the display device, a first image information which is an observation image when illuminated with broad-band visible light, and a second image information which is an observation image when illuminated with narrow-band light. This makes it easy to compare and observe a normal observation image with an image in which specific information is emphasized.

[0109] (18) Endoscopic device of (16) or (17), The display means captures first image information under visible light including the light emitted from the first light source and the excitation light emitted from the wavelength conversion member, An endoscope device that simultaneously displays, by superimposing, either the aforementioned visible light or a second image information captured under illumination light including light emitted from the second light source. This endoscopic device displays a normal observation image and an image with specific information emphasized overlaid on top of each other, making comparative observation easier.

[0110] (19) An endoscope device as described in any one of items (13) to (18), The system includes a recording means for recording information including the observed image output from the image processing means, An endoscope device in which the recording means records the observation image and the light intensity ratio in relation to each other. With this endoscopic device, observation images are recorded in relation to the light intensity ratio set at the time of acquisition. Therefore, the range of applications for the recorded observation images can be expanded by processing the images according to the light intensity ratio at the time of acquisition. [Explanation of Symbols]

[0111] 11 Endoscopy 13 Control device 15 Display 17 Input section 19 Endoscope insertion site 21 Image sensor 23 Control section 35 Tip 37A,37B Irradiation port 41 Light source device 43 processors 45A, 45B, 45C, 45D optical fibers 51. Blue laser light source (first light source) 53. Blue laser light source (second light source) 55 Light source control unit 57. Phosphors (wavelength conversion materials) 59 Light deflection / diffusion member 65 Image Processing Unit 67 Control Unit 71 Display screen 73 Endoscopic Image Area 75 Normal Image Switching Button 77 Narrowband Optical Switching Button 79 Adjustment bar 81 snacks 83 Storage section 85 Adjustment part 87 Select button 89 Switch (Toggle switch) 91 Blue-green laser light source 93 Red laser light source 95 Dichroic Prism 97. Phosphors (wavelength conversion materials) 100, 200, 300 Endoscopes A, B Profile B1,B2 blood vessels

Claims

1. An endoscope system comprising an endoscope, a light source device, a processor, and a monitor, The system comprises a first light source that uses a semiconductor light-emitting element that emits blue light, and a second light source that uses a semiconductor light-emitting element that emits purple light. The device includes a wavelength conversion member that generates emitted light by absorbing a portion of the emitted light from the first light source and exciting it, and the blue light that is transmitted without being absorbed. The system includes an optical element positioned in the optical path of the light emitted from the second light source, which combines the light associated with the first light source. The system allows selection of observation light modes, including a first observation using white light and a second observation using illumination light with a spectrum different from that of the white light. A switching unit that switches the observation light mode by operating a button, An endoscope system having an adjustment unit that adjusts the light intensity of the first light source and the second light source by moving an indicator within a predetermined range.

2. The endoscopic system according to claim 1, The switching unit is provided in the operating section of the endoscope system.

3. The endoscopic system according to claim 2, The switching unit is an endoscope system in which the observation light mode is changed by changing the amount of emitted light from the first light source and the emitted light from the second light source each time the switching unit is pressed.

4. An endoscope system according to any one of claims 1 to 3, An endoscope system in which the switching of the observation light mode by the switching unit and the adjustment of the light intensity of the first light source and the second light source by the adjustment unit can be performed independently of each other.

5. An endoscope system according to any one of claims 1 to 4, The processor receives an image signal from the endoscope and outputs an observation image. Within the same screen of the aforementioned monitor, an information display area is provided, separate from the endoscopic image area that displays the observation image. The endoscope system displays information regarding the observation light mode in the information display area.

6. An endoscope system according to any one of claims 1 to 5, The second observation described above is performed using an endoscopic system that increases or decreases the ratio of the narrowband light component to the total illumination light component.

7. An endoscope system according to any one of claims 1 to 6, The wavelength conversion member is an endoscope system in which the excitation emission amount from the second light source is at least 1 / 3 or less compared to the excitation emission amount from the first light source.

8. An endoscope system according to any one of claims 1 to 7, The light source device is an endoscope system that obtains a desired amount of light emission by controlling the current applied to the first light source and the second light source.

9. The endoscopic system according to claim 8, The light source device is an endoscope system that controls the amount of light emitted by superimposing a pulse-modulated pulsed current onto the applied current.

10. An endoscope system according to any one of claims 1 to 9, The optical element is an endoscope system that transmits the blue light emitted from the first light source.

11. An endoscope system according to any one of claims 1 to 10, The endoscopic system includes a processor that receives an image signal from the endoscope, outputs an observation image, and performs image processing to enhance and display vascular information within the observation image.

12. An endoscope system according to any one of claims 1 to 11, An endoscope system comprising a processor that receives an image signal from the endoscope, outputs an observation image, applies a color conversion coefficient according to the observation light mode, and corrects the color tone of the observation image.

13. An endoscope system according to any one of claims 1 to 12, The aforementioned switching unit is an endoscope system in which a switch or button can switch between multiple preset emission light intensity levels.

14. An endoscope system according to any one of claims 1 to 13, An endoscope system in which the switching unit automatically sets a preset amount of emitted light based on the operator's identification information or the individual identification information of the endoscope.

15. An endoscope system according to any one of claims 1 to 14, The light source device has a third light source that emits red light, The processor is an endoscope system capable of individually adjusting the amount of light emitted from each of the aforementioned light sources.

16. An endoscope system according to any one of claims 1 to 15, An endoscope system in which either the first light source or the second light source is set to the short wavelength side, straddling the maximum peak wavelength of the hemoglobin absorption spectrum, and the other is set to the long wavelength side.

17. An endoscope system according to any one of claims 1 to 16, An endoscope system in which at least one of the first light source and the second light source is a light-emitting diode.

18. An endoscope system according to any one of claims 1 to 17, The wavelength conversion member is an endoscope system containing a phosphor material.

19. An endoscope system according to any one of claims 1 to 18, An endoscope system in which the processor records an observation image with added information regarding the observation light mode.

20. An endoscope system according to any one of claims 1 to 19, An endoscope system in which the processor receives an image signal from the endoscope, outputs an observation image, and performs image processing to correct the color tone or brightness of the observation image according to the observation light mode.

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