LIGHTING SOURCE DEVICE

Abstract

The present invention addresses the objective of providing an illumination light source device with which, when an object is simultaneously irradiated with excitation light capable of stimulating a fluorescent substance contained in the object, the color rendering of mixed light from the illumination light and the excitation light is brought closer to the color reproducibility of natural light. This illumination light source device 100 is provided with an illumination light source 110, which directs illumination light L1 onto an object 101, an excitation light source 120, which directs excitation light L2, capable of stimulating a fluorescent substance contained in the object 101, onto the object 101, and a control unit 140 for controlling the illumination light source 110 and the excitation light source 120.When the illumination light L1 and the excitation light L2 are directed simultaneously at the object 101, the control unit 140 adjusts the intensity and / or the wavelength of the illumination light L1 or the excitation light L2 so that the spectral distribution of the mixed light L3, which combines the illumination light L1 and the excitation light L2, is brought closer to the spectral distribution of natural light than when only the illumination light L1 is directed at the object 101.

Description

[Technical field]

[0001] The present invention relates to an illumination light source device and relates in particular to an illumination light source device that is used in an endoscope and can be applied to any luminal tissue within the body, such as digestive organs, e.g. the intestinal tract and the stomach, as well as respiratory organs in the human body. [State of the art]

[0002] Some conventional endoscopes, etc., emit not only illumination light but also excitation light via a light guide element, such as an optical fiber, as an illumination light source device to illuminate the interior of a human body onto an object.

[0003] For example, patent literature 1 discloses a device for observation with fluorescent light, comprising an illumination light source for emitting white light as illumination light and an excitation light source for emitting excitation light, in order to shine illumination light on an object during illumination light observation and to shine excitation light on the object during excitation light observation. [Citation list][Patent literature]

[0004] [PTL 1] Japanese Disclosure Publication No. 2008-237652 [Summary of the invention][Technical problem]

[0005] While white light, which is illumination light, can be produced by mixing three colors of light (e.g., red light, green light, and blue light) emitted by a red light emitter, a green light emitter, and a blue light emitter, white light obtained by mixing these three colors of light does not include all wavelengths of visible light as in natural light (sunlight during the day), so the color rendering of an object is worse compared to natural light.

[0006] In this context, the inventors discovered for the first time that color rendering can be improved by mixing a wavelength component of the excitation light with wavelength components of three colors of illumination light, by simultaneously introducing excitation light that is generally not present during illumination light observation. The inventors also discovered that white light with a color rendering closer to that of natural light can be produced with a limited number of light sources in a lighting device by approximating the spectral distribution of the mixed light, obtained by blending these lights while wavelength components of other colors (excitation light) are mixed with wavelength components of the three colors red, green, and blue, to the spectral distribution of natural light.

[0007] The object of the present invention is to obtain lighting light source devices that are able to approximate the color rendering of mixed light, consisting of lighting light and excitation light, to the color rendering of natural light when excitation light, which can excite a fluorescent material contained in an object, is simultaneously shone onto the object along with lighting light. [Solution to the task]

[0008] The present invention provides for the following points. (Point 1)

[0009] Lighting light source device, comprising: a light source for illuminating an object with light; an excitation light source for irradiation with excitation light that can excite a fluorescent material contained in the object; and a control unit for controlling the illumination light source and the excitation light source; wherein the control unit adjusts at least one intensity and wavelength of the illumination light or the excitation light such that a spectral distribution of mixed light consisting of the illumination light and the excitation light more closely approximates a spectral distribution of natural light when the illumination light and the excitation light are simultaneously radiated onto the object, compared to when the illumination light alone is radiated onto the object. (Point 2)

[0010] Illumination light source device according to point 1, wherein the control unit adjusts an intensity and a wavelength of the illumination light when the illumination light and the excitation light are simultaneously shone onto the object. (Point 3)

[0011] Illumination light source device according to point 1, wherein the control unit adjusts an intensity and a wavelength of the excitation light when the illumination light and the excitation light are simultaneously shone onto the object. (Point 4)

[0012] Lighting light source device according to point 1, wherein the illumination light source comprises a plurality of light sources for illumination which emit illumination light with different wavelengths, and where the wavelength of the excitation light differs from the wavelength of the illumination light emitted by the majority of light sources for illumination. (Point 5)

[0013] Illumination light source device according to point 4, wherein the control unit controls the intensity of the light from the light sources for illumination with a wavelength adjacent to a wavelength of the excitation light, such that it decreases when the illumination light and the excitation light are simultaneously shone onto the object, compared with when the illumination light alone is shone onto the object. (Point 6)

[0014] Illumination light source device according to point 4 or 5, wherein the control unit controls a wavelength of light from the light sources for illumination with a wavelength adjacent to a wavelength of the excitation light, such that it is further away from a wavelength of the excitation light when the illumination light and the excitation light are simultaneously radiated onto the object, compared with when the illumination light alone is radiated onto the object. (Point 7)

[0015] Illumination light source device according to point 5, wherein the control unit does not change the intensity of the light from the light sources for illumination with a wavelength that is not adjacent to a wavelength of the excitation light when the illumination light and the excitation light are simultaneously shone onto the object. (Point 8)

[0016] Lighting light source device according to point 4, wherein the lighting light source comprises a blue light source, a green light source and a red light source and wherein a wavelength of the excitation light source has a wavelength between a wavelength of the light from the blue light source and a wavelength of the light from the green light source. (Point 9)

[0017] Illumination light source device according to point 8, wherein the control unit controls the intensities of the light from the blue light source and the light from the green light source with wavelengths adjacent to both sides of a wavelength of the excitation light, such that they decrease when the illumination light and the excitation light are simultaneously shone onto the object, compared with when the illumination light alone is shone onto the object. (Point 10)

[0018] Illumination light source device according to point 8 or 9, wherein the control unit controls the wavelengths of the light from the blue light source and the light from the green light source such that they are further away from a wavelength of the light from the excitation light source when the illumination light and the excitation light are simultaneously shone onto the object, compared with when the illumination light alone is shone onto the object. (Point 11)

[0019] Illumination light source device according to point 9, wherein the control unit does not change the intensity of the light from the red light source with a wavelength that is not adjacent to a wavelength of the excitation light when the illumination light and the excitation light are simultaneously shone onto the object. (Point 12)

[0020] Illumination light source device according to point 1, wherein the control unit has a mode for illumination with the illumination light alone and a mode for simultaneous illumination with the illumination light and with the excitation light as illumination light observation modes, and has a mode for illumination with excitation light alone as excitation light observation mode, and these modes are configured to be selectable, wherein in the mode for simultaneous illumination with the illumination light and with the excitation light an intensity of the light from the excitation light source is controlled such that it is lower than an intensity of the light from the excitation light source emitted in the excitation light observation mode. (Point 13)

[0021] Illumination light source device according to point 1, wherein the control unit adjusts at least one intensity and wavelength of the illumination light so that the color rendering by mixed light consisting of the illumination light and the excitation light is about 10 to about 30 better with respect to an average color rendering index Ra than the color rendering by the illumination light alone. (Point 14)

[0022] Endoscope comprising the illumination light source device according to point 1. (Point 15)

[0023] Light guiding element comprising the lighting light source device according to point 1. (Point 16)

[0024] Method for adjusting the wavelength of illumination light, which is simultaneously shone onto an object along with excitation light that excites a fluorescent material of the object, wherein a wavelength of the illumination light is adjusted so that a spectral distribution of the mixed light, which consists of the illumination light and the excitation light, more closely approximates a spectral distribution of natural light when the illumination light and the excitation light are simultaneously shone onto the object, compared to when the illumination light alone is shone onto the object. [Advantageous effects of the invention]

[0025] The object of the present invention is to obtain lighting light sources that are able to approximate the color rendering of mixed light, consisting of lighting light and excitation light, to the color rendering of natural light when excitation light, which can excite a fluorescent material contained in an object, is simultaneously shone onto the object along with lighting light. [Brief description of the drawings] [ Fig. 1] Fig. Figure 1 is a diagram that schematically shows the lighting light source device according to the invention. [ Fig. 2] Fig. Figure 2 is a diagram showing the specific configuration of the lighting light source device 100 according to embodiment 1 of the invention. [ Fig. 3] Fig. 3 is a diagram that shows how the [function] works. Fig. 2 shows the lighting light source device 100 of embodiment 1. [ Fig. 4] Fig. 4 is a diagram that shows modification example 1 of the in Fig. 2 shows the lighting light source device 100 of embodiment 1. [ Fig. 5] Fig. 5 is a diagram that shows modification example 2 of the in Fig. 2 shows the lighting light source device 100 of embodiment 1. [ Fig. 6] Fig. 6 is a diagram that shows modification example 3 of the in Fig. 2 shows the lighting light source device 100 of embodiment 1. [ Fig. 7] Fig. Figure 7 is a diagram showing the configuration of the lighting light source device 200 according to embodiment 2 of the invention. [ Fig. 8] Fig. Figure 8 is a diagram that illustrates how the [function] works. Fig. 7 shows the lighting light source device 200 of embodiment 2. [Description of the embodiments]

[0026] The present invention is described below. Unless expressly stated otherwise, the terms used herein are to be understood in their generally accepted meanings within the field of knowledge. Unless otherwise defined, all terminology and scientific terms used herein thus have the same meaning as the general understanding of those skilled in the art in the field to which the present invention relates. In case of any conflict, the present description (including the definitions) shall prevail.

[0027] The term "approximately" here refers to a range of ± 10% of the number given after the term "approximately".

[0028] Fig. Figure 1 is a diagram that schematically shows the lighting light source device according to the invention.

[0029] The object to be solved by the present invention is to provide lighting light source devices capable of approximating the color rendering of mixed light, consisting of lighting light and excitation light, to that of natural light when excitation light, which can excite a fluorescent material contained in an object, is simultaneously shone onto the object along with lighting light. This object has been achieved by providing a lighting light source device 100 comprising: a light source 110 for irradiating an object 101 with light L1; an excitation light source 120 for irradiation with excitation light L2, which can excite a fluorescent material contained in the object 101; and a control unit 140 for controlling the illumination light source 110 and the excitation light source 120; wherein the control unit 140 adjusts at least one intensity and wavelength of the illumination light L1 or the excitation light L2 such that a spectral distribution of mixed light L3, consisting of the illumination light L1 and the excitation light L2, more closely approximates a spectral distribution of natural light when the illumination light L1 and the excitation light L2 are simultaneously radiated onto the object 101, compared with when the illumination light L1 alone is radiated onto the object 101.

[0030] As long as the illumination light source device 100 according to the invention adapts at least one of the intensity and wavelength of the illumination light or the excitation light such that a spectral distribution of mixed light, consisting of the illumination light L1 and the excitation light L2, more closely approximates the spectral distribution of natural light when the illumination light L1 and the excitation light L2 are simultaneously radiated onto the object 101, compared to when the illumination light L1 alone is radiated onto the object, further configurations are not particularly limited and can have any configuration.

[0031] For example, if illumination light and excitation light are simultaneously shone onto an object, a control unit can adjust the intensity and wavelength of the illumination light, or adjust one of the intensity and wavelength of the illumination light.

[0032] When illumination light and excitation light are simultaneously shone onto an object, the control unit can also adjust the intensity and wavelength of the excitation light, adjust one of the intensity and wavelength of the illumination light, or adjust both the excitation light and the illumination light.

[0033] Preferably, an illumination light source comprises a plurality of light sources for illumination, each emitting illumination light with different wavelengths, and the wavelength of the light from the excitation light source differs from the wavelengths of the plurality of illumination lights emitted by the illumination light source because light with a wavelength not contained in the illumination light can be supplemented with excitation light, thereby allowing the spectral distribution of light illuminating an object to approximate the spectral distribution of natural light by simultaneous irradiation with the illumination light and the excitation light.

[0034] However, if excitation light with a wavelength different from the wavelength of the illumination light (e.g., a plurality of illumination lights with different wavelengths) is introduced simultaneously with the illumination light, it is effective to reduce the intensity of the light from a light source to the illumination with a wavelength adjacent to the wavelength of the excitation light, so that in mixed light consisting of the illumination light and the excitation light, the energy of the light at or near the wavelength of the excitation light would not be greater than the energy at a wavelength component corresponding to natural light.

[0035] In such a case, it is also effective, in mixed light consisting of illumination light and excitation light, to configure the wavelength of the light from the light source to the illumination with a wavelength adjacent to the wavelength of the excitation light, so that it is further away from the wavelength of the excitation light, thus preventing the energy of the light at or near the wavelength of the excitation light from being stronger than the energy at a wavelength component corresponding to natural light.

[0036] Furthermore, if excitation light with a wavelength different from the wavelengths of a plurality of illumination lights is simultaneously shone onto an object along with a plurality of illumination lights with different wavelengths, it may be more advantageous to reduce the intensity of the light from the light source for illumination with a wavelength adjacent to the wavelength of the excitation light, and to adjust the wavelength of the light from the light source for illumination with a wavelength adjacent to the wavelength of the excitation light so that it is further away from the wavelength of the excitation light, if the wavelength of the excitation light is close to the wavelength of the light from the light source for illumination with a wavelength adjacent to it.

[0037] When illumination and excitation light are simultaneously shone onto an object, it can be advantageous that the intensity of the light from a light source for illumination with a wavelength that is not adjacent to the wavelength of the excitation light is not changed (is configured so that it is the same as if only illumination light were shone onto the object).

[0038] For example, to prevent the energy of the light at or near the wavelength of the excitation light from being greater than the energy at a wavelength component corresponding to natural light in the mixed light consisting of illumination and excitation light, when light from the multiple light sources forming the illumination light is simultaneously shone onto an object along with light from an excitation light source, this can be addressed by reducing the intensity of the light from the illumination source with a wavelength adjacent to the wavelength of the excitation light, etc. This is because a measure to reduce the intensity of the light from the illumination source with a wavelength not adjacent to the wavelength of the excitation light, etc., would more likely result in the spectral distribution of the mixed light being further removed from the spectral distribution of natural light. (Light source)

[0039] An illumination light source is a light source used for illuminated observation that emits white light with wavelengths that partially cover the entire visible range (particularly from about 400 nm to about 650 nm). In one embodiment, a plurality of light sources contained in an illumination light source are a blue light source, a green light source, and a red light source. While the excitation light has a wavelength between blue and green light, a plurality of light sources contained in an illumination light source can consist of two light sources capable of emitting white light, or of four or more light sources whose emitted light has different wavelengths.

[0040] In this context, semiconductor light emitters, such as light-emitting diodes (LEDs) or laser diodes (LDs), can be used as a plurality of light sources for illumination, forming a single illumination light source.

[0041] While laser diodes emit light with less scattering in the spectral distribution on both sides of a central wavelength compared to light-emitting diodes, there are laser diodes in which the length of the cavity is physically adjusted by a control signal so that the wavelengths can be dynamically changed.

[0042] Light sources for illumination can have a variable wavelength. Any means can be used to change the wavelength. For example, a grating can be used as a wavelength conversion element, or a wavelength-variable semiconductor laser can be used as the light source for illumination. Examples of wavelength-variable semiconductor lasers include thermally tunable DFB lasers (distributed feedback lasers), which change the refractive index by changing the temperature; DBR lasers (distributed Bragg reflectors), which change the refractive index by current injection; broadband wavelength-variable DBR lasers with a mechanism to double the change in the reflection index by current injection; micromachined surface-emitting lasers, which change the cavity length by micromachining; and micromachined external-cavity lasers, which change the angle of an optical filter by micromachining. (Excitation light source)

[0043] Excitation light sources are light sources that emit a predefined narrowband excitation light. The wavelength of the excitation light can be any wavelength, as long as it is capable of exciting a fluorescent material administered to an object for therapeutic purposes.

[0044] In one embodiment, the wavelength of the excitation light emitted by an excitation light source excites a fluorescent material and is 490 nm, which corresponds to a wavelength between blue and green light. However, the present invention is not limited to this. If the fluorescent material is, for example, 5-aminolevulinic acid, the wavelength for its excitation is approximately 410 nm. If the fluorescent material is a fluorescent marker using hydroxymethylrhodamine green, the wavelength for excitation is approximately 450 to 480 nm. If the fluorescent material is a talaporfin sodium polymer, the wavelength for its excitation is approximately 670 nm. The wavelength of the excitation light emitted by an excitation light source can be in the near-infrared range (approximately 800 nm to approximately 1000 nm).If the fluorescent material is, for example, ICG (indocyanine green), the wavelength for its excitation is approximately 800 nm. In this way, any desired wavelength of excitation light can be selected to match the fluorescent material being excited. If the excitation light wavelength is in the near-infrared range, the fluorescent material is detected with a near-infrared detection camera. This configuration allows a near-infrared image to be added to a visible light image, enabling the detection of lesions across a broader area. The visible light bandwidth can be configured to be narrow, and the longer wavelengths can be added, among other methods, to display a near-infrared image.

[0045] In particular, if the fluorescent material is 5-aminolevulinic acid or hydroxymethylrhodamine green, wavelengths from violet to blue-green, for which the power of an illumination light source is low, are added, thus improving color rendering. If the fluorescent material is a talaporfin sodium polymer, wavelengths from orange to red, which are very similar to the color of blood, can be added, allowing the condition of a lesion to be accurately determined. (Control unit)

[0046] A control unit regulates the timing of the emission of light from an illumination light source and light from an excitation light source, the intensity and wavelength of the light, etc. For example, if a plurality of illumination light sources forming an illumination light source are a blue light source, a green light source, and a red light source, and the excitation light in one embodiment has a wavelength between blue and green light, the control unit regulates the intensities of blue and green light with wavelengths adjacent to both sides of the wavelength of the excitation light, such that they decrease when illumination light and excitation light are simultaneously shone onto an object, compared to when the illumination light alone is shone onto the object.

[0047] Alternatively, if a plurality of light sources forming an illumination light source are a blue light source, a green light source, and a red light source, and the excitation light has a wavelength between blue and green light, the control unit adjusts the wavelengths of the blue and green light so that they are further away from the wavelength of the excitation light when the illumination light and the excitation light are simultaneously shone onto an object, compared to when only the illumination light is shone onto the object.

[0048] If the intensity or wavelength of blue and green light is adjusted in this way based on a wavelength of the excitation light, the intensity of the red light, which is not adjacent to the wavelength of the excitation light, can furthermore be configured to remain the same and not change when only illumination light is shone on an object.

[0049] In one embodiment, a control unit can be configured to have a mode for illumination with illumination light alone, a mode for simultaneous illumination with illumination and excitation light as illumination light observation modes, and a mode for illumination with excitation light alone as excitation light observation mode, and these modes can be selected. In this case, the control unit can control the intensity of the excitation light in a mode for simultaneous illumination with illumination and excitation light so that it is lower than the intensity of the excitation light applied in the excitation light observation mode.

[0050] Furthermore, a control unit adjusts at least one of the intensity and wavelength of the illumination light so that the color rendering of mixed light, consisting of the illumination light and the excitation light, is better than the color rendering of the illumination light alone. Color rendering is evaluated using the average color rendering index Ra, which is commonly used in the lighting field.

[0051] Preferably, a control unit improves the color rendering by mixed light, consisting of illumination light and excitation light, by about 10 or more in terms of an average color rendering index Ra compared to the color rendering by the illumination light alone.

[0052] Such an illumination light source can be used in an endoscope. The color rendering of white light can be improved by simultaneous irradiation with excitation light and illumination light during fluorescence observation with excitation light on the surface within one lumen, such as of a digestive organ, e.g., the intestinal tract or stomach, or a respiratory organ of an object, or during observation with white light.

[0053] The present invention also provides a method for adjusting the wavelength of illumination light that is simultaneously shone onto an object along with excitation light that excites a fluorescent material of the object. The method for adjusting the wavelength of the illumination light sets the wavelength of the illumination light such that the spectral distribution of the mixed light, consisting of the illumination light and the excitation light, more closely approximates the spectral distribution of natural light when the illumination light and the excitation light are shone onto the object simultaneously, compared to when the illumination light alone is shone onto the object. Further conditions for adjusting the wavelength of the illumination light are not limited but are optional.

[0054] In this way, other configurations are not particularly limited, as long as the illumination light source device of the invention adjusts at least one intensity and wavelength of the illumination light such that a spectral distribution of mixed light, consisting of the illumination light and the excitation light, more closely approximates a spectral distribution of natural light when the illumination light and the excitation light are simultaneously radiated onto an object, compared to the case where the illumination light alone is radiated onto the object. However, the following embodiment, which dynamically changes the intensity of the illumination light, is provided as embodiment 1, and the following embodiment, which dynamically adjusts the intensity and wavelength of the illumination light, is provided as embodiment 2.

[0055] It is assumed that the lighting device of embodiment 1 uses LEDs as blue, green, and red light sources, which constitute the plurality of light sources for illumination within a single lighting device. It is assumed that the lighting device of embodiment 2 uses laser diodes as blue, green, and red light sources, which constitute the plurality of light sources for illumination within a single lighting device. It is also assumed that the lighting devices in both embodiments use a laser diode as an excitation light source.

[0056] The embodiments of the invention are described below with reference to the drawings. (Version 1)

[0057] Fig. Figure 2 is a diagram showing the specific configuration of the lighting light source device 100 according to embodiment 1 of the invention.

[0058] The illumination light source device 100 of embodiment 1 is used in an endoscope and can be applied to any luminal tissue, such as digestive organs (i.e., the intestinal tract and stomach) as well as the respiratory organs in the human body. However, the illumination light source of the invention is not limited to observation with an endoscope, but can also be used for observation during a laparotomy, etc.

[0059] The illumination light source device 100 comprises: an illumination light source 110 for illuminating an object 101 with illumination light L10; an excitation light source 120 for illuminating with excitation light L2, which can excite a fluorescent material contained in the object 101; and a control unit 140a for controlling the illumination light source 110 and the excitation light source 120.

[0060] The control unit 140a adjusts the intensities of the illumination light L10 and the excitation light L2 so that a spectral distribution of mixed light L3, which consists of the illumination light L10 and the excitation light L2, more closely approximates a spectral distribution of natural light when the illumination light L10 and the excitation light L2 are simultaneously shone onto the object 101 than when the illumination light L10 alone is shone onto the object 101. (Light source 110)

[0061] The lighting source 110 has light sources of three colors for emitting white light. The three color light sources are a blue light source 111, a green light source 112, and a red light source 113.

[0062] A blue light-emitting diode (LED) emitting blue light (wavelength of approximately 440 nm) L11 is used as a blue light source (blue LED) 111. A green light-emitting diode (LED) emitting green light L12 (wavelength of approximately 540 nm) is used as a green light source (green LED) 112. A red light-emitting diode (LED) emitting red light (wavelength of approximately 635 nm) L13 is used as a red light source (red LED) 113. If the intensities of the three colors L11 to L13 are identical, the color rendering of white light obtained by mixing these three colors L11 to L13 is Ra = 80, in relation to the average color rendering index Ra, which is an indicator of color rendering compared to natural light (sunlight during the day). For natural light, the average color rendering index Ra = 100.

[0063] The lighting light source 110 has an LED driver circuit 110 for controlling the blue LED 111, the green LED 112 and the red LED 113 based on a lighting control signal Ct1 from the control unit 140a. The LED driver circuit 110 is configured to supply a blue driver current D11, a green driver current D12 and a red driver current D13 to the blue LED 111, the green LED 112 and the red LED 113 respectively. (Excitation light source 120)

[0064] The excitation light source 120 comprises a laser diode (excitation LD) 121, which emits excitation light (wavelength of approximately 490 nm) L2, and an LD driver circuit 120a for driving the excitation LD 121 based on an excitation control signal Ct2 from the control unit 140a. The LD driver circuit 120a is configured to supply the excitation driver current D2 to the excitation LD 121. As described above, the excitation light L2 has a wavelength between that of the blue light L11 and the green light L12. (Mixer 30)

[0065] The lighting light source device 100 has a mixer 130 which outputs mixed light L31 as white light by mixing the blue light L11 from the blue LED 111, the green light L12 from the green LED 112, the red light L13 from the red LED 113 and the excitation light L2 from the excitation LED 121.

[0066] It goes without saying that if only the blue light L11, the green light L12, and the red light L13 are emitted, the mixer 130 mixes the blue light L11, the green light L12, and the red light L13, and only the illumination light L10 shines as mixed light L31 onto object 101. If the excitation light L2 is emitted alone, the excitation light L2 alone is shone onto object 101. (Light guiding element)

[0067] A light guiding element (not shown) may be present to guide the light L31 mixed by mixer 30 to the vicinity of object 101.

[0068] The light guide element can have any shape. In one embodiment, a light guide element is an optical fiber, but this is not limited to optical fibers. For example, an optical fiber that utilizes the difference in the refractive index of glass, a hollow fiber with air or inert gas as a core, a liquid fiber with a liquid as a core, a non-deformable waveguide made from processed glass or resin, etc., can also be used. (Control unit 140a)

[0069] Furthermore, the control unit 140a has a first operating mode for irradiation with the illumination light L10 alone, a second operating mode for simultaneous irradiation with the illumination light L10 and the excitation light L2 as illumination light observation modes, and a third operating mode for irradiation with excitation light alone as excitation light observation mode. The control unit is configured to select these operating modes based on an operating signal Sm from an operator input and to control the LED driver circuit 110a and the LD driver circuit 120a in accordance with the selected operating mode.

[0070] In this context, the control unit 140a controls the intensities of the blue light L11 and the green light L12, with wavelengths adjacent to both sides of a wavelength of the excitation light L2, such that they decrease by the difference X1 (approximately 20% of the original intensity) when the illumination light L1 and the excitation light L2 are simultaneously shone onto the object 101, compared to the case where only the illumination light L10 is shone onto the object 101 (see Fig. 3(b)).

[0071] Furthermore, in an operating mode for simultaneous irradiation with illumination light and excitation light, the control unit 140a controls the excitation light source 120 in such a way that the intensity of the excitation light decreases by the difference X2 (approximately 90% of the original intensity) compared to the intensity of the excitation light irradiated in the second operating mode (excitation light observation mode) (see Fig. 3(a)). As a concrete example, the illuminance during illumination (410 [lm]) is reduced to 40 [lm] during excitation. However, the intensity of the excitation light varies considerably depending on the sensitivity of a fluorescent material.

[0072] The operation of the lighting light source device 100 of embodiment 1 will now be described.

[0073] The following section describes the switching of the operating mode in the illumination light source device 100, which is carried out when the tip of an endoscope comprising the illumination light source device 100 is inserted into a lumen of an object and moved to a target location to observe the surface of the target location.

[0074] Fig. 3 is a diagram that shows how the [function] works. Fig. The lighting light source device 100 shown in the 2 is shown. Fig. Figure 3(a) shows the dynamic switching of the intensity of the excitation light L2. Fig. Figure 3(b) shows the dynamic switching of the intensity of the illumination light L10 (blue light L11 and green light L12). Fig. Figure 3(c) shows the superimposed spectral distributions of the illumination light L10 (blue light L1, green light L2 and red light L13) and the excitation light L2, which are illuminated simultaneously. (First operating mode)

[0075] Initially, until an endoscope is moved within one lumen of object 101 and reaches a target location, the operator selects a mode for illuminating object 101 solely with the illumination light L10 (first operating mode) by activating an operating unit (not shown). The reason for this is that it is not particularly necessary to brightly illuminate the area while the endoscope is being moved within one lumen.

[0076] As soon as the operating signal Sm is input from the operating unit (not shown) into the control unit 140a at this time, the control unit 140a controls the LED driver circuit 110a and the LD driver circuit 120a with the lighting control signal Ct1 and the excitation control signal Ct2, respectively, causing the blue LED 111, the green LED 112, and the red LED 113 to emit blue light L11, green light L12, and red light L13 at a specific optimal intensity (see the spectral distribution on the left side of the figure). Fig. 3(b)). In such a case, the blue light L11, the green light L12, and the red light L13 have the same intensity. Furthermore, the excitation light source 120 does not emit the excitation light L2. The color rendering of the illumination light L10 at this time was Ra = 80, expressed as the average color rendering index Ra. (Second operating mode)

[0077] When observing with natural light, while an endoscope has reached the target location in one lumen of object 101, an operator selects a mode for simultaneous irradiation with the illumination light L10 and the excitation light L2 (second operating mode) by operating an operating unit (not shown).

[0078] When the lighting control signal Ct1 and the excitation control signal Ct2 are output to the LED driver circuit 110a and the LD driver circuit 120a by the control unit 140a, which at this time has received the operating signal Sm from the operating unit (not shown), this results in a state in which the blue LED 111, the green LED 112 and the red LED 113 emit the blue light L11, the green light L12 and the red light L13 respectively, and the excitation LD 121 emits the excitation light L2.

[0079] In this case, the blue LED 111 and the green LED 112 reduce the intensity of the blue light L11 and the green light L12, respectively, to approximately 0.8 times the intensity of the red light L13 (see the spectral distribution on the right in Fig. 3(b)). In other words, the intensities of the blue light L11 and the green light L12 are reduced by the difference X1 (about 20% of the original intensity) compared to irradiation with the illumination light alone.

[0080] This is intended to prevent the excitation light L2, whose wavelength lies between the blue light L11 and the green light L12, from mixing with the blue light L11, the green light L12 and the red light L13, which leads to an increased intensity of the light with a wavelength close to the wavelength of the blue light L11 and the green light L12, so that the spectral distribution of the mixed light L31 would be further away from the spectral distribution of natural light overall.

[0081] In the above case, the intensities of the blue light L11 and the green light L12 adjacent to the excitation light L2 were adjusted, but the intensity of the excitation light L2 can also be adjusted instead of the intensities of the blue light L11 and the green light L12. In particular, the excitation LD121 can reduce the intensity of the excitation light L2 to about 0.1 times that of irradiation with the excitation light L2 alone (see Fig. 3(a)).

[0082] In excitation light observation, the intensity of the excitation light is often set high to excite a fluorescent material. When simultaneously irradiating an object with excitation light, the effects on the object, such as a temperature increase, can be minimized by reducing the intensity of the excitation light.

[0083] Fig. Figure 3(c) shows the superimposed spectral distributions of each light when the illumination light L1 and the excitation light L2 are illuminated simultaneously, with the intensities of the blue light L11 and the green light L12 reduced compared to illumination with the illumination light L10 alone and the intensity of the excitation light L2 reduced compared to illumination with the excitation light L2 alone.

[0084] In this way, the intensities of the blue light L11 and green light L12, with wavelengths adjacent to both sides of the wavelength of the excitation light L2 contained in the illumination light L10, are reduced when the illumination light L1 and the excitation light L2 are illuminated simultaneously, compared to illumination with the illumination light L1 alone. This causes the spectral distribution of the mixed light L3, consisting of the illumination light L1 and the excitation light L2, to approximate the spectral distribution of natural light. Thus, the color rendering of the mixed light L31 can be improved to more closely approximate the color rendering of natural light. The color rendering of the illumination light L10 at this time was Ra = 90, expressed as the average color rendering index Ra.

[0085] Since an object can be observed while the color reproduction is improved in this way, the spot to be observed can be found accurately and efficiently.

[0086] When the illumination light L10 and the excitation light L2 are simultaneously illuminated in embodiment 1, the adverse effects on the spectral distribution of the illumination light L10 caused by the excitation light L2, which contaminates the illumination light L10, are suppressed by reducing the intensities of the blue light L11 and green light L12 with wavelengths adjacent to the wavelength of the excitation light L2, and by reducing the intensity of the contaminating excitation light L2. However, the method for suppressing the adverse effects due to the contamination of the illumination light L10 by the excitation light L2 is not limited to dynamically reducing the intensities of the blue light L11, green light L12, and excitation light L2, as shown in embodiment 1. Another method can also be used in combination with this.In the following modification example 1 of embodiment 1, a case is described in which a method for presetting the wavelengths of the blue light L11 and green light L12 is used simultaneously, the wavelengths of which are adjacent to the wavelength of the excitation light L2 contaminating the illumination light L10. (Third operating mode)

[0087] For excitation light observation while an endoscope has reached the target location in one lumen of object 101, an operator selects a mode to irradiate object 101 solely with the excitation light L2 (third operating mode) by operating an operating unit (not shown).

[0088] As soon as the operating signal Sm is input from the operating unit (not shown) into the control unit 140a at this time, the LED driver circuit 110a and the LD driver circuit 120a are controlled by the lighting control signal Ct1 and the excitation control signal Ct2 from the control unit 140a, causing the blue LED 111, the green LED 112 and the red LED 113 to stop emitting light and the excitation LD 121 to emit the excitation light L2 at a specific optimal intensity (see the spectral distribution on the left of the figure). Fig. 3(a)). (Modification example 1 of embodiment 1)

[0089] Fig. 4 is a diagram that shows modification example 1 of the in Fig. Figure 2 shows an illumination light source device 100, which shows an embodiment in which the intensities of the blue light L11 and green light L12 are dynamically switched in the same way as in embodiment 1, after the wavelengths of the blue light L11 and green light L12 in the illumination light L10 have been changed in advance in accordance with the wavelength of the excitation light L2 which is simultaneously emitted with the illumination light L10.

[0090] In Fig. 4(a) shows in particular the specific changes in the wavelengths of the blue light L11 and the green light L12, which take into account the wavelength of the excitation light L2. Fig. Figure 4(b) shows the dynamic switching of the intensity of the excitation light L2. Fig. Figure 4(c) shows the dynamic switching of the intensities of the blue light L11 and the green light L12. Fig. Figure 4(d) shows the superimposed spectral distributions of the simultaneously incident blue light L11, green light L12, red light L13 and excitation light L2.

[0091] The illumination light source device of modification example 1 of embodiment 1 configures the wavelengths of the blue light L11 and the green light L12 such that they are further away from the wavelength of the excitation light L2 that contaminates the illumination light L1 by adjusting the composition of the semiconductor material that forms the blue LED 111 and the green LED 112, which are installed as illumination light source 110 in the illumination light source device of embodiment 1.

[0092] Specifically, in modification example 1 of embodiment 1, the wavelength of the blue light L11 is approximately 430 nm, which is configured such that it is about 10 nm further away from the wavelength of the excitation light L2 than the wavelength of the blue light L11 (approximately 440 nm) in embodiment 1, taking into account the wavelength of the excitation light L2 (approximately 490 nm). Fig. 4(a)). In modification example 1 of embodiment 1, the wavelength of the green light L12 is approximately 550 nm ( Fig. 4(a)), which is configured to be about 10 nm further away from the wavelength of the excitation light L2 than the wavelength of the green light L12 (about 540 nm) in embodiment 1, taking into account the wavelength of the excitation light L2 (about 490 nm) ( Fig. 4(a)).

[0093] In modification example 1 of embodiment 1, a light irradiation process is carried out as irradiation with the illumination light L10 alone (first operating mode), as irradiation with the excitation light L2 alone (third operating mode), and as simultaneous irradiation with the illumination light L1 and the excitation light L2 (second operating mode) in the same way as in the illumination light source device 100 described above in embodiment 1, after the wavelengths of the blue light L11 and the green light L12 have been adapted among the three RGB colors in the illumination light L10, taking into account the wavelength of the excitation light L2, which is thus illuminated simultaneously with the illumination light L10.

[0094] In other words, in order to reduce the adverse effect in advance in modification example 1 due to the contamination of the illumination light L10 by the excitation light L2, the blue light L11 and the green light L12, whose wavelengths are configured to be further away from the wavelength of the excitation light L2, are dynamically reduced when the illumination light L10 and the excitation light L2 are illuminated simultaneously, compared to when the illumination light L10 is illuminated alone, taking the wavelength of the excitation light L2 into account. Fig. 4(c)). Furthermore, with the simultaneous irradiation described above, the intensity of the excitation light L2 is dynamically reduced compared to irradiation with the excitation light L2 alone ( Fig. 4(b)).

[0095] Fig. Figure 4(d) shows the superimposed spectral distributions of the blue light L11, the green light L12, the red light L13 and the excitation light L2 when the object 101 is simultaneously irradiated with the illumination light L1 and the excitation light L2.

[0096] Modification example 1 of embodiment 1 can thereby effectively suppress the adverse effect due to the contamination of the illumination light L10 by the excitation light L2 when simultaneously irradiated with the illumination light L10 and the excitation light L2.

[0097] The color rendering by mixed light consisting of the illumination light L10 and the excitation light L2 was Ra = 92 at this time, expressed as the average color rendering index Ra.

[0098] However, the wavelengths of blue light L11, green light L12, and red light L13 are modified compared to illumination with light L10 alone in order to reduce the adverse effect of contamination from the excitation light L2. This can lead to a deterioration of the spectral distribution when illuminated with light L10 alone. Therefore, the wavelengths of blue light L11 and green light L12 must be adjusted, taking into account the wavelength of the excitation light L2, depending on which takes priority for color rendering when illuminated with light L10 alone or for color rendering when illuminated with light L10 and excitation light L2 simultaneously.

[0099] Embodiment 1 and Modification Example 1 thereof have been disclosed using the light-emitting diodes blue LED 111, green LED 112, and red LED 113 as the blue, green, and red light sources, respectively, which are contained in the illumination light source 110. However, laser diodes can also be used instead of light-emitting diodes as these three-color light sources. An illumination light source device in Embodiment 1 that uses laser diodes instead of light-emitting diodes is described below as Modification Example 2 of Embodiment 1, and an illumination light source device in Modification Example 1 of Embodiment 1 that uses laser diodes instead of light-emitting diodes is described as Modification Example 3 of Embodiment 1. (Modification example 2 of embodiment 1)

[0100] Fig. Figure 5 is a diagram illustrating the illumination light source device 110 of embodiment 1, which uses laser diodes (LDs) instead of light-emitting diodes (LEDs), as modification example 2 of the one described in Fig. 2 shown embodiment 1 shows.

[0101] Fig. Figure 5(a) shows in particular the spectral distributions of a blue light source, green light source and red light source using an LD compared to the use of LEDs as light sources for the three colors. Fig. Figure 5(b) shows the dynamic switching of the intensity of the excitation light L2. Fig. Figure 5(c) shows the dynamic switching of the intensities of the blue light L11a and the green light L12a emitted by an LD. Fig. Figure 5(d) shows the superimposed spectral distributions of the blue light L11a, the green light L12a, the red light L13a and the excitation light L2, which are emitted simultaneously by LDs.

[0102] For a blue light source, a green light source, and a red light source using a laser diode as a semiconductor light emitter, the wavelengths of blue light L11a, green light L12a, and red light L13a would be 470 nm, 530 nm, and 640 nm, respectively, which differs slightly from the wavelengths of blue light L11, green light L12, and red light L13b (440 nm, 540 nm, and 635 nm) when using light-emitting diodes (see Fig. 5(a)).

[0103] However, if illumination light and excitation light L2 are irradiated simultaneously, the intensities of the blue light L11a and the green light L12a are reduced in the same way as in embodiment 1 compared to illumination light alone (see Fig. 5(c)). The specific degree of reduction X5 is about 10%, which differs from about 20% in an embodiment with a light-emitting diode. Upon simultaneous irradiation, the intensities of the blue light L11a and the green light L12a are reduced to about 0.9 times the intensity of the red light L13a. The spectral distributions of the blue light L11a, the green light L12a, the red light L13a, and the excitation light L2, which at that time is contained in the mixed light of illumination and excitation light, are in Fig. Figure 5(d) shows the color rendering by the mixed light L31. The color rendering was Ra = 75, expressed as the average color rendering index Ra.

[0104] When irradiated simultaneously, the intensity of the excitation light L2 is also reduced in some cases in the same way as in embodiment 1, compared to irradiation with the excitation light alone ( Fig. 5(b)). The specific degree of decrease X4 is approximately 90%. (Modification example 3 of embodiment 1)

[0105] Fig. Figure 6 is a diagram illustrating the illumination light source of modification example 1 of embodiment 1, in which laser diodes (LDs) are used instead of light-emitting diodes (LEDs), as modification example 3 of the one described in Fig. The lighting light source device 100 shown in the 2 is shown.

[0106] Specifically, it shows Fig. 6 an embodiment of the dynamic switching of the intensities of the blue light L11a and the green light L12a in the same way as in modification example 1 of embodiment 1, after the wavelengths of the blue light L11a and green light L12a emitted by the LD have been changed in advance according to the wavelength of the excitation light L2, which is emitted simultaneously with the illumination light.

[0107] In Fig. 6(a) shows in particular the specific changes in the wavelengths of the blue light L11a and the green light L12a, which take into account the wavelength of the excitation light L2. Fig. Figure 6(b) shows the dynamic switching of the intensity of the excitation light L2. Fig. Figure 6(c) shows the dynamic switching of the intensities of the blue light L11a and the green light L12a. Fig. Figure 6(d) shows the superimposed spectral distributions of the blue light L11a, the green light L12a, the red light L13a and the excitation light L2, which are emitted simultaneously by the LDs.

[0108] The illumination light source device of modification example 3 of embodiment 1 configures the wavelengths of the blue light L11a and the green light L12a contained in the illumination light such that they are further away from the wavelength of the excitation light L2 contaminating the illumination light by adjusting the composition of the semiconductor material forming the blue LD and the green LD incorporated as the illumination light source in the illumination light source device of modification example 2 of embodiment 1.

[0109] Specifically, in modification example 3 of embodiment 1, the wavelength of the blue light L11a is approximately 430 nm, which is configured such that it is about 40 nm further away from the wavelength of the excitation light L2 than the wavelength of the blue light L11a (approximately 470 nm) in modification example 2 of embodiment 1, taking into account the wavelength of the excitation light L2 (approximately 490 nm). Fig. 6(a)). In modification example 3 of embodiment 1, the wavelength of the green light L12a is about 550 nm, which is configured such that it is about 20 nm further away from the wavelength of the excitation light L2 than the wavelength of the green light L12a (about 530 nm) in modification example 2 of embodiment 1, taking into account the wavelength of the excitation light L2 (about 490 nm) ( Fig. 6(a)).

[0110] In modification example 3 of embodiment 1, a light irradiation process is carried out as irradiation with the illumination light alone (first operating mode), as irradiation with the excitation light L2 alone (third operating mode), and as simultaneous irradiation with the illumination light and the excitation light L2 (second operating mode) in the same way as in the modification example 2 of embodiment 1 described above, after the wavelengths of the blue light L11a and the green light L12a have been adapted under the laser light of the three colors contained in the illumination light, taking into account the wavelength of the excitation light L2, which is thus irradiated simultaneously with the illumination light.

[0111] To reduce the adverse effect due to the contamination of the illumination light by the excitation light L2 in modification example 3, the blue light L11a and the green light L12a are used with wavelengths configured to be further away from the wavelength of the excitation light L2 than when the illumination light alone is illuminated, taking the wavelength of the excitation light L2 into account, and the intensities of the blue light L11a and the green light L12a with wavelengths adjacent to the wavelength of the excitation light L2 decrease dynamically when the illumination light and the excitation light L2 are illuminated simultaneously, compared to when only the illumination light L1 is illuminated. Fig. 6(c)). The degree of decrease in intensity X5 at this time is approximately 10% of the original intensity. Furthermore, the intensity of the excitation light L2 decreases dynamically during the simultaneous irradiation described above compared to irradiation with the excitation light L2 alone ( Fig. 6(b)). The degree of decrease in intensity X5 at this time is approximately 10% of the original intensity.

[0112] Fig. Figure 6(d) shows the superimposed spectral distributions of the blue light L11a, the green light L12a, the red light L13a and the excitation light L2 when the object 101 is simultaneously irradiated with the illumination light and the excitation light L2.

[0113] Modification example 3 of embodiment 1, in which laser diodes (LDs) are used instead of the light-emitting diodes (LEDs) of modification example 1 of embodiment 1, can thereby effectively suppress the adverse effect due to the contamination of the illumination light by the excitation light L2 when simultaneously irradiated with the illumination light and the excitation light L2 in the same way as modification example 1 of embodiment 1, in which light-emitting diodes are used as semiconductor light emitters.

[0114] The color rendering by mixed light consisting of illumination light and excitation light was Ra = 80 at that time, expressed as the average color rendering index Ra.

[0115] However, the wavelengths of the blue light L11a and the green light L12a are changed compared to irradiation with the illumination light alone in order to reduce the adverse effect of contamination by the excitation light L2, so that the spectral distribution can deteriorate in the same way when irradiated with the illumination light alone as in modification example 1 of embodiment 1. Therefore, the adjustment of the wavelengths of the blue light L11a and the green light L12a must be carried out taking into account the wavelength of the excitation light L2, depending on which has priority for color rendering when irradiated with the illumination light alone or for color rendering when irradiated with both the illumination light and the excitation light L2 simultaneously.

[0116] In this context, embodiment 2 describes an illumination light source device that dynamically changes both the intensity and the wavelength of the illumination light, both when irradiated with illumination light alone and when irradiated with illumination light and excitation light simultaneously, as an illumination light source device that is able to independently adjust the spectral distribution when irradiated with illumination light alone and the spectral distribution of the illumination light when irradiated with illumination light and excitation light L2 simultaneously. (Version 2)

[0117] Fig. Figure 7 is a diagram showing the configuration of the lighting light source device 200 according to embodiment 2 of the invention.

[0118] The illumination light source device 200 of embodiment 2 comprises an illumination light source 210 which can dynamically adjust the intensity and wavelength of the emitted illumination light L20 instead of the illumination light source 110 in the illumination light source device 100 of embodiment 1 and can change the intensity and wavelength of the illumination light L20 so that the spectral distribution of mixed light L32, which consists of the illumination light L20 and the excitation light L2, approximates the spectral distribution of natural light when the object 101 is simultaneously irradiated with the illumination light L20 and the excitation light L2, compared to irradiation with the illumination light L20 alone.

[0119] Thus, a control unit 240 of the lighting light source device 200 is configured so that it can control not only the intensity but also the wavelength of the lighting light L20 from the lighting light source 210, in contrast to the control unit 140a of the lighting light source device 100 of embodiment 1.

[0120] The excitation light source 120 and the mixer 130 are identical to those in the illumination light source device 100 of embodiment 1. The illumination light source 210 and the control unit 240 are described in detail below. (Light source 210)

[0121] The illumination light source 210 has a blue light source 211, a green light source 212, and a red light source 213 in the same way as the illumination light source 110 of embodiment 1. In embodiment 2, however, laser diodes with variable wavelengths are used for each of the blue and green light sources, and a laser diode with a fixed wavelength is used for the red light source.

[0122] The blue light source (blue LD) 211 can adjust the wavelength of the emitted blue light L21 within a predefined wavelength range (e.g., from at least approximately 470 nm to approximately 430 nm). Furthermore, the green light source (green LD) 212 can adjust the wavelength of the emitted green light L22 within a predefined wavelength range (e.g., from at least approximately 530 nm to approximately 550 nm). The wavelength of the emitted red light L23 is set to approximately 640 nm in the red light source (red LD) 213.

[0123] The blue light source (blue LD) 211, however, can switch the wavelength of the emitted blue light L21 between approximately 470 nm and approximately 430 nm, and the green light source (green LD) 212 can switch the wavelength of the emitted green light L22 between approximately 530 nm and approximately 550 nm. In this respect, the wavelength of the blue light L21, i.e., approximately 470 nm, and the wavelength of the green light L22, e.g., approximately 530 nm, are wavelengths at which excellent color rendering is achieved when only illumination light L20 is incident, and the wavelength of the blue light L21, i.e., approximately 430 nm, and the wavelength of the green light L22, e.g., approximately 550 nm, are wavelengths at which excellent color rendering is achieved when only illumination light L20 is incident. B. about 550 nm, are wavelengths with which excellent color rendering is achieved when the illumination light L20 and the excitation light L2 are simultaneously illuminated.In this embodiment, the blue light source and the green light source were configured to be wavelength-variable, but the red light source can also be configured to be wavelength-variable, or one or more of the blue light source, green light source and red light source can be configured to be wavelength-variable. (Control unit 240)

[0124] In the lighting light source device 200, the control unit 240 is configured to output a lighting control signal Ct1 to the lighting light source 210, an excitation control signal Ct2 to the excitation light source 120, and a control signal C21 for the blue wavelength and a control signal C22 for the green wavelength to the lighting light source 210, based on an operating signal Sm at an operating unit (not shown).

[0125] The lighting light source 210 has an LD driver circuit 210a for controlling the blue LD 211, the green LD 212 and the red LD 213 based on the lighting control signal Ct1 from the control unit 240. In particular, the LD driver circuit 210a is configured to supply a blue driver current D21, a green driver current D22 and a red driver current D23 to the blue LD 211, the green LD 212 and the red LD 213 respectively, based on the lighting control signal Ct1 from the control unit 240.The control unit 240 is configured to change the intensity of the blue light L21 from the blue LD 211 and the intensity of the green light L22 from the green LD 212 by adjusting the blue driver current D21 to the blue LD 211 and the green driver current D22 to the green LD 212 between an embodiment in which only the illumination light L20 is emitted and an embodiment in which the illumination light L20 and the excitation light L2 are emitted simultaneously.

[0126] The control unit 240 is configured to switch the wavelengths of the blue light L21 and the green light L22 between an embodiment in which only the illumination light L20 is emitted and an embodiment in which the illumination light L20 and the excitation light L2 are emitted simultaneously, by outputting the control signal for the blue wavelength C21 to the blue LD 211 and the control signal for the green wavelength C22 to the green LD 212.

[0127] The control unit 240 is also configured to change the intensity of the excitation light L2 from the excitation LD 121 by adjusting the excitation driver current D2, which is output to the excitation LD 121, between an embodiment in which only the illumination light L20 is emitted and an embodiment in which the illumination light L20 and the excitation light L2 are emitted simultaneously.

[0128] The functionality of the lighting light source device 200 of embodiment 2 will now be described.

[0129] Fig. Figure 8 is a diagram that illustrates how the [function] works. Fig. 7 shows the lighting light source device 200 of embodiment 2. Fig. Figure 8(a) shows the dynamic switching of the intensity of the excitation light L2. Fig. Figure 8(b) shows the dynamic switching of the intensities and wavelengths of the blue light L21 and the green light L22. Fig. Figure 8(c) shows superimposed spectral distributions of the simultaneously incident blue light L21, green light L22, red light L23 and excitation light L2.

[0130] When the illumination light source device 200 with such a configuration shines the illumination light L20 alone onto the object 101, as soon as the control unit 240 receives the operating signal Sm from an operating unit (not shown) and the illumination control signal Ct1 is output by the control unit 240 to the LD driver circuit 210a of the illumination light source 210, the LD driver circuit 210a switches on the blue LD 211, green LD 212 and red LD 213 based on the illumination control signal Ct1, wherein the blue LD 211, the green LD 212 and the red LD 213 emit the blue light L21, the green light L22 and the red light L23 with the same intensity, such that the wavelength of the blue light L21 is about 470 nm, the wavelength of the green light L22 is about 530 nm and the wavelength of the red light L23 is about 640 nm.At this time, the excitation light source 120 is not operated, so that the object 101 is not irradiated with the excitation light L2.

[0131] When the excitation light L2 is shone solely onto object 101, as soon as the control unit 240 receives the operating signal Sm from the operating unit (not shown) and the excitation control signal Ct2 is output from the control unit 240 to the excitation light source 120, the LD driver circuit 122 of the excitation light source 120 activates the excitation LD 121 based on the excitation control signal Ct2, causing the excitation LD 121 to emit the excitation light L2 with a wavelength of approximately 490 nm. At this time, the illumination light source 210 is not operating, so object 101 is not illuminated with the illumination light L20.

[0132] When the illumination light L20 and the excitation light L2 are simultaneously shone onto object 101, the control unit 240, which has received the operating signal Sm from the operating unit (not shown), outputs the control signal C21 for the blue wavelength and the control signal C22 for the green wavelength, together with the illumination control signal Ct1, to the illumination light source 210. At this time, the control unit 240 simultaneously outputs the excitation control signal Ct2 to the excitation light source 120.

[0133] In the case of the illumination light source 210, the LD driver circuit 210a controls the blue LD 21, the green LD 22 and the red LD 23 based on the illumination control signal Ct1 such that the intensities of the blue light L21 and the green light L22 are approximately 0.9 times the intensity of the red light L23 (see the spectral distribution above right in Fig. 8(b)). This embodiment describes a device for observing the interior of the body using a light-guiding element consisting of an optical fiber, but it should be obvious that the illumination light source device of the invention can also be applied to devices that directly illuminate a lesion with a light source in surgery, laparotomy, etc.

[0134] At this point, the wavelength of the emitted blue light L21 is adjusted to approximately 430 nm based on the control signal C21 for the blue wavelength in the blue LD21, so that it is further away from the wavelength of the excitation light L2 (approximately 470 nm) when irradiated with the illumination light L20 alone (approximately 470 nm). Simultaneously, the wavelength of the emitted green light LD22 is adjusted to approximately 550 nm based on the control signal C22 for the green wavelength in the green LD22, so that it is further away from the wavelength of the excitation light L2 (approximately 490 nm) compared to the wavelength when irradiated with the illumination light L20 alone (approximately 530 nm) (see the spectral distribution in the lower left of the diagram). Fig. 8(b)).

[0135] As a result, the wavelength is changed so that it is further away from the wavelength of the excitation light L2 when the illumination light L1 and the excitation light L2 are illuminated simultaneously, compared to the case where only the illumination light L10 is illuminated (see the spectral distribution in the upper left of the diagram). Fig. 8(b)), and the blue light L21 and the green light L22, which have an intensity reduced to approximately 0.9 times that of the red light L23, are emitted from the illumination light source 210. At this point, the wavelength and intensity of the red light L23 are no different than when irradiated with the illumination light L20 alone (see the spectral distribution below right in Fig. 8(b)).

[0136] When the intensities of the illumination lights L21-L23 of the three colors are identical and the respective wavelengths are approximately 470 nm, approximately 530 nm and approximately 640 nm, the color rendering (Ra) of the white light obtained by mixing the illumination lights L21-L23 of the three colors as described above was Ra = 50 in relation to the average color rendering index Ra, which is an indicator of color rendering compared to natural light (sunlight during the day).

[0137] Meanwhile, the color rendering of white light, obtained by mixing the illumination lights L21-L23 of the three colors and the excitation light L2, could achieve Ra = 80 with respect to the average color rendering index Ra, which is an indicator of the color rendering of mixed light compared to natural light (sunlight during the day), by adjusting the wavelengths of the blue light L21 and the green light L22 to approximately 430 nm and approximately 550 nm respectively, and thus being further away from the wavelength of the excitation light L2 (approximately 490 nm), and by attenuating the intensities of the blue light L21 and the green light L22, whose wavelengths are adjacent to the wavelength of the excitation light L2, so that they are lower than the intensity of the red light L23.

[0138] Embodiment 2 discloses an embodiment in which a laser diode is used as a wavelength-variable light emitter, wherein the wavelength can be changed using a wavelength-changing element by using a fixed-wavelength light-emitting diode as the light emitter.

[0139] Embodiments 1 and 2 disclose an illumination light source device that adjusts at least one of the intensity and wavelength of the illumination light together with the intensity of the excitation light, so that the spectral distribution of mixed light, consisting of illumination light and excitation light, more closely approximates the spectral distribution of natural light when the illumination light and the excitation light are simultaneously shone onto an object, compared to the case where only the illumination light is shone onto the object. However, the illumination light source device of the invention can adjust at least one of the intensity and wavelength of only the excitation light, instead of adjusting the intensity and wavelength of the illumination light, or it can adjust both the illumination light and the excitation light when the illumination light and the excitation light are simultaneously shone onto an object.

[0140] As disclosed above, the present invention is illustrated by the use of its preferred embodiments. However, the present invention should not be interpreted as being limited to such embodiments. It is understood that the scope of the present invention is to be interpreted solely on the basis of the claims. It is understood that an equivalent scope may be determined by those skilled in the art based on the descriptions of the present invention and the general knowledge derived from the specific descriptions of the preferred embodiments of the invention. It is understood that all references cited herein should be incorporated by reference in the same manner in which the content is specifically described herein. [Commercial Applicability]

[0141] The present invention is useful as an invention with which one can obtain an illumination light source device which can approximate the color rendering of mixed light, consisting of illumination light and excitation light, to the color rendering of natural light when excitation light, which can excite a fluorescent material contained in an object, is simultaneously radiated onto the object with illumination light. [List of reference symbols] 100 lighting light source device 101 objects 110 Lighting light source 110a LED driver circuit 111 blue light source (blue LED) 112 green light source (green LED) 113 red light source (red LED) 120 Excitation light source 120a, 210a LD driver circuit 121 Excitation light emitter (excitation LD) 130 mixers 140, 140a, 240 control unit 211 blue light source (blue LD) 212 green light source (green LD) 213 red light source (red LD) C21 Control signal for blue wavelength C22 Control signal for green wavelength CT1 lighting control signal Ct2 excitation control signal D11, D21 blue driver current D12, D22 green driver current D13, D23 red driver current D2 Excitation driver current L10, L20 lighting light L11, L11a blue light (B) L12, L12a green light (G) L13, L13a red light (R) L2 excitation light (E) L3, L31, L32 mixed light Sm operating signal QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2008-237652

[0004]

Claims

[1] Lighting light source device comprising: a light source for illuminating an object with light; an excitation light source for irradiation with excitation light that can excite a fluorescent material contained in the object; and a control unit for controlling the illumination light source and the excitation light source; wherein the control unit adjusts at least one intensity and wavelength of the illumination light or the excitation light such that a spectral distribution of mixed light consisting of the illumination light and the excitation light more closely approximates a spectral distribution of natural light when the illumination light and the excitation light are simultaneously radiated onto the object, compared to when the illumination light alone is radiated onto the object. [2] Lighting light source device according to claim 1, wherein the control unit adjusts an intensity and a wavelength of the lighting light when the lighting light and the excitation light are simultaneously shone onto the object. [3] Lighting light source device according to claim 1, wherein the control unit adjusts an intensity and a wavelength of the excitation light when the lighting light and the excitation light are simultaneously shone onto the object. [4] Lighting light source device according to claim 1, wherein the lighting light source comprises a plurality of light sources for illumination which emit lighting light with different wavelengths, and wherein a wavelength of the excitation light differs from a wavelength of the lighting light emitted by the plurality of light sources for illumination. [5] Illumination light source device according to claim 4, wherein the control unit controls the intensity of the light from the light sources for illumination with a wavelength adjacent to a wavelength of the excitation light such that it decreases when the illumination light and the excitation light are simultaneously radiated onto the object, compared with when the illumination light alone is radiated onto the object. [6] Lighting light source device according to claim 4 or 5, wherein the control unit controls a wavelength of light from the light sources for illumination with a wavelength adjacent to a wavelength of the excitation light such that it is further away from a wavelength of the excitation light when the illumination light and the excitation light are simultaneously radiated onto the object, compared with when the illumination light alone is radiated onto the object. [7] Lighting light source device according to claim 5, wherein the control unit does not change the intensity of the light from the light sources for illumination with a wavelength that is not adjacent to a wavelength of the excitation light when the illumination light and the excitation light are simultaneously radiated onto the object. [8] Lighting light source device according to claim 4, wherein the lighting light source includes a blue light source, a green light source and a red light source and wherein a wavelength of the excitation light source has a wavelength between a wavelength of the light from the blue light source and a wavelength of the light from the green light source. [9] Illumination light source device according to claim 8, wherein the control unit controls the intensities of the light from the blue light source and the light from the green light source with wavelengths adjacent to both sides of a wavelength of the excitation light such that they decrease when the illumination light and the excitation light are simultaneously radiated onto the object, compared with when the illumination light alone is radiated onto the object. [10] Illumination light source device according to claim 8 or 9, wherein the control unit controls the wavelengths of the light from the blue light source and the light from the green light source such that they are further away from a wavelength of the light from the excitation light source when the illumination light and the excitation light are simultaneously radiated onto the object, compared with when the illumination light alone is radiated onto the object. [11] Lighting light source device according to claim 9, wherein the control unit does not change the intensity of the light from the red light source with a wavelength that is not adjacent to a wavelength of the excitation light when the lighting light and the excitation light are simultaneously shone onto the object. [12] Illumination light source device according to claim 1, wherein the control unit has a mode for illuminating with the illumination light alone and a mode for simultaneously illuminating with the illumination light and with the excitation light as illumination light observation modes, and has a mode for illuminating with excitation light alone as excitation light observation mode, and these modes are configured to be selectable, wherein in the mode for simultaneous illuminating with the illumination light and with the excitation light an intensity of the light from the excitation light source is controlled such that it is lower than an intensity of the light from the excitation light source emitted in the excitation light observation mode. [13] Lighting light source device according to claim 1, wherein the control unit adjusts at least one intensity and wavelength of the lighting light so that the color rendering by mixed light consisting of the lighting light and the excitation light is about 10 to about 30 better with respect to an average color rendering index Ra than the color rendering by the lighting light alone. [14] Endoscope comprising the illumination light source device according to claim 1. [15] Light guiding element comprising the lighting light source device according to claim 1. [16] Method for adjusting the wavelength of illumination light which is simultaneously shone onto an object with excitation light which excites a fluorescent material of the object, wherein a wavelength of the illumination light is adjusted such that a spectral distribution of the mixed light consisting of the illumination light and the excitation light more closely approximates a spectral distribution of natural light when the illumination light and the excitation light are shone onto the object simultaneously, compared with when the illumination light alone is shone onto the object.

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