JP2022015779A - Luminaire and endoscope apparatus - Google Patents

Abstract

To provide a luminaire capable of enhancing color rendering, and an endoscope apparatus.SOLUTION: A first visible light source 11, a second visible light source 12, and a third visible light source 13 emit visible light rays of colors different from each other. The first visible light source 11, the second visible light source 12, and the third visible light source 13 emit light rays of a plurality of wavelengths different from each other in the wavelength bands of respectively corresponding colors, as a multi wavelength light source. A mixer 21 mixes the light emitted from the first visible light source 11, the light emitted from the second visible light source 12, the light emitted from the third visible light source 13, and light emitted from an excitation light source 14.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to lighting devices and endoscopic devices.

In the conventional optical fiber probe, a light emitting diode lighting device is used as a light source. The light emitting diode lighting device includes a red light emitting diode, a green light emitting diode, and a blue light emitting diode (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-38847

In the conventional optical fiber probe as described above, the color rendering property is low because the light of the three primary colors of red, green, and blue is simply used.

The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to obtain a lighting device and an endoscope device capable of improving color rendering properties.

The lighting device according to the present disclosure includes a plurality of visible light sources that emit visible light of different colors from each other and a mixer that mixes the light emitted from the plurality of visible light sources, and the plurality of visible light sources includes at least one. A multi-wavelength light source, including a multi-wavelength light source, emits light of a plurality of different wavelengths within the wavelength band of the corresponding color.

According to the lighting device and the endoscope device of the present disclosure, the color rendering property can be improved.

It is a block diagram which shows the endoscope apparatus by Embodiment 1 by a part block. It is a block diagram which shows the lighting apparatus of FIG. It is a graph which shows the relationship between the wavelength and the relative intensity of the light emitted from the 1st visible light source, the 2nd visible light source, the 3rd visible light source, and the excitation light source of FIG. It is a block diagram which shows the detailed structure of the 1st visible light source and the 1st drive part of FIG. It is a graph which shows an example of the light emission intensity characteristic by the electric current of a semiconductor laser light emitting element. It is a graph which shows an example of the wavelength characteristic by the temperature of a semiconductor laser light emitting element. It is a graph which shows the difference of the degree of deep penetration into a subject by the wavelength of light. It is a figure which shows an example of the image obtained by irradiating light with xenon illumination. It is a figure which shows the image obtained by irradiating the same subject as FIG. 8 with light by the lighting apparatus of Embodiment 1. FIG. It is explanatory drawing which shows the state of light at the time of obtaining the image of FIG. It is explanatory drawing which shows the state of light at the time of obtaining the image of FIG. It is a figure which shows the example of the color rendering index in the case of using the lighting apparatus which emits the light of one wavelength for each of a red wavelength band, a green wavelength band, and a blue wavelength band. It is a figure which shows the example of the color rendering index when the lighting apparatus of Embodiment 1 is used.

Hereinafter, embodiments will be described with reference to the drawings.
Embodiment 1.
FIG. 1 is a configuration diagram showing the endoscope device according to the first embodiment by a partial block. In the figure, the endoscope device includes an endoscope main body 1, a lighting device 2, a lighting transmission cable 3, a control device 4, a control cable 5, and a display device 6.

The lighting device 2 is connected to the endoscope main body 1 via a lighting transmission cable 3. The light from the lighting device 2 is transmitted to the endoscope main body 1 via the lighting transmission cable 3.

The control device 4 is connected to the endoscope main body 1 via a control cable 5. The display device 6 is connected to the control device 4. The image captured by the endoscope main body 1 is displayed by the display device 6. The control device 4 controls the endoscope main body 1, the lighting device 2, and the display device 6.

FIG. 2 is a block diagram showing the lighting device 2 of FIG. The lighting device 2 includes a first visible light source 11, a second visible light source 12, a third visible light source 13, an excitation light source 14, a first drive unit 15, a second drive unit 16, a third drive unit 17, and a fourth drive unit 18. , A lighting control unit 19, a lighting power supply unit 20, and a mixer 21.

The first visible light source 11, the second visible light source 12, and the third visible light source 13 emit visible light of different colors from each other. In this example, laser light is used as visible light. The excitation light source 14 emits light having an excitation wavelength of the fluorescence contrast agent.

The first driving unit 15 drives the first visible light source 11. The second drive unit 16 drives the second visible light source 12. The third drive unit 17 drives the third visible light source 13. The fourth drive unit 18 drives the excitation light source 14.

The lighting control unit 19 controls the first drive unit 15, the second drive unit 16, the third drive unit 17, and the fourth drive unit 18. As a result, the illumination control unit 19 controls the light emission of the first visible light source 11, the second visible light source 12, the third visible light source 13, and the excitation light source 14. Further, the illumination control unit 19 can simultaneously emit light from the first visible light source 11, the second visible light source 12, the third visible light source 13, and the excitation light source 14, or selectively emit light.

The lighting power supply unit 20 supplies electric power to the lighting control unit 19 and other necessary parts.

The mixer 21 includes light emitted from the first visible light source 11, light emitted from the second visible light source 12, light emitted from the third visible light source 13, and light emitted from the excitation light source 14. To mix. As the mixer 21, a laser light mixing rod integrator is used.

The first visible light source 11, the second visible light source 12, the third visible light source 13, and the excitation light source 14 are connected to each other by a plurality of optical fibers. The output from the mixer 21 is input to the lighting transmission cable 3.

FIG. 3 is a graph showing the relationship between the wavelength and the relative intensity of the light emitted from the first visible light source 11, the second visible light source 12, the third visible light source 13, and the excitation light source 14 of FIG. The first visible light source 11, the second visible light source 12, and the third visible light source 13 emit light having a plurality of wavelengths different from each other within the wavelength band of the corresponding colors as the multi-wavelength light source.

Specifically, the first visible light source 11 corresponds to blue light and emits light having two different wavelengths in the blue wavelength band. In FIG. 2, the output from the first visible light source 11 has spectral characteristics S1 and S2.

The second visible light source 12 corresponds to green and emits light having two different wavelengths in the green wavelength band. In FIG. 2, the output from the second visible light source 12 has spectral characteristics S3 and S4.

The third visible light source 13 corresponds to red and emits light having two different wavelengths in the red wavelength band. In FIG. 2, the output from the third visible light source 13 has spectral characteristics S5 and S6.

The excitation light source 14 emits light having a wavelength longer than that in the visible region. The visible region is a region from 400 nm to 700 nm. In FIG. 2, the output from the excitation light source 14 has the spectral characteristic S7.

FIG. 4 is a block diagram showing a detailed configuration of the first visible light source 11 and the first driving unit 15 of FIG. The first visible light source 11 includes a first light emitting element 31, a second light emitting element 32, a temperature sensor 33, and a cooling device 34.

The first light emitting element 31 and the second light emitting element 32 emit light having two different wavelengths from each other in the blue wavelength band. The central wavelength of the light emitted by the first light emitting element 31 is, for example, 450 nm. The central wavelength of the light emitted by the second light emitting element 32 is, for example, 462 nm. As the first light emitting element 31 and the second light emitting element 32, semiconductor laser light emitting elements are used, respectively.

The temperature sensor 33 detects the ambient temperature of the first light emitting element 31 and the second light emitting element 32. The cooling device 34 cools the first light emitting element 31 and the second light emitting element 32.

The light emitted from the first light emitting element 31 is transmitted to the mixer 21 through the first optical fiber 35. The light emitted from the second light emitting element 32 is transmitted to the mixer 21 through the second optical fiber 36.

The first drive unit 15 has a first detection circuit 38, a second detection circuit 39, and a light emitting element drive circuit 40.

The first detection circuit 38 detects the current supplied to the first light emitting element 31. The second detection circuit 39 detects the current supplied to the second light emitting element 32.

The light emitting element drive circuit 40 causes the first light emitting element 31 and the second light emitting element 32 to emit light at the same time based on the command from the lighting control unit 19. Further, the light emitting element drive circuit 40 drives and controls the cooling device 34 based on the information from the temperature sensor 33.

Although FIG. 4 shows the configuration of the first visible light source 11, the configurations of the second visible light source 12 and the third visible light source 13 are the same as those of the first visible light source 11. However, the central wavelength of the light emitted by the first light emitting element of the second visible light source 12 is, for example, 512 nm. The central wavelength of the light emitted by the second light emitting element of the second visible light source 12 is, for example, 520 nm.

The central wavelength of the light emitted by the first light emitting element of the third visible light source 13 is, for example, 650 nm. The central wavelength of the light emitted by the second light emitting element of the third visible light source 13 is, for example, 664 nm.

Further, the excitation light source 14 does not have a second light emitting element. The central wavelength of the light emitted by the first light emitting element of the excitation light source 14 is, for example, 780 nm. 780 nm is the excitation wavelength of indocyanine green as a fluorescence contrast agent.

Further, although FIG. 4 shows the configuration of the first drive unit 15, the configurations of the second drive unit 16, the third drive unit 17, and the fourth drive unit 18 are the same as those of the first drive unit 15. .. However, the fourth drive unit 18 does not have a second detection circuit.

FIG. 5 is a graph showing an example of emission intensity characteristics due to the current of a semiconductor laser light emitting device. The light emitted by the semiconductor laser light emitting device is accompanied by resonance due to light, and requires a current of a certain threshold value or more. In FIG. 5, point A is the threshold current of the semiconductor laser light emitting device. The illumination control unit 19 controls the semiconductor laser light emitting element so that a current equal to or larger than the threshold current flows in order to maintain light emission.

Further, the illumination control unit 19 is a first light emitting element 31 so as to be a point C which is a median value in the range from the point A to the point B in FIG. 5 based on the current detected by the first detection circuit 38. Controls the current flowing through. The range from the point A to the point B in FIG. 5 is a range in which the relative emission intensity changes linearly with respect to the current, which is equal to or higher than the threshold current. Therefore, the point B is the maximum value of the current whose relative emission intensity changes linearly, or a value in the vicinity of the maximum value. Similarly, the illumination control unit 19 controls the current flowing through the second light emitting element 32 based on the current detected by the second detection circuit 39.

FIG. 6 is a graph showing an example of wavelength characteristics depending on the temperature of the semiconductor laser light emitting device. The emission wavelength of a semiconductor laser light emitting device is determined by the physical characteristics and structure of the device, but it depends on the temperature during light emission. In the example of FIG. 6, light having a wavelength within the specified range is emitted within the ambient temperature range from 0 ° C to 25 ° C.

In this example, the light emitting element drive circuit 40 controls the cooling device 34 so that the temperature detected by the temperature sensor 33 is a temperature from 20 ° C to 25 ° C. As a result, the wavelength of the light emitted by the first visible light source 11 is controlled to 450 nm ± 2 nm and 462 nm ± 2 nm. Here, ± 2 nm is the bandwidth of the emission wavelength of each light emitting element.

Further, the wavelength of the light emitted by the second visible light source 12 is controlled to 512 ± 2 nm and 520 ± 2 nm. The wavelength of the light emitted by the third visible light source 13 is controlled to 650 ± 2 nm and 664 ± 2 nm. Further, the wavelength of the light emitted by the excitation light source 14 is controlled to 780 ± 2 nm.

The blue light from the first visible light source 11, the green light from the second visible light source 12, and the red light from the third visible light source 13 are simultaneously emitted and mixed by the mixer 21. White light is emitted from the mixer 21.

Further, the mixer 21 diffuses the incident light. As a result, the coherent property of the laser light is suppressed, the incident light is converted into the same characteristics as the natural light, and the light having the spectral characteristics shown in FIG. 3 is output. The mixer 21 is connected to an external device via a dedicated attachment (not shown) so that the light can be used as efficiently as possible.

In such a lighting device 2, the first visible light source 11, the second visible light source 12, and the third visible light source 13 emit light having a plurality of wavelengths different from each other within the wavelength bands of the corresponding colors. Therefore, the color rendering property can be improved. In addition, the color reproduction range can be expanded.

For example, in an endoscope device, the state in the body cavity can be confirmed more clearly by improving the color rendering property.

Further, the first visible light source 11, the second visible light source 12, and the third visible light source 13 have a first light emitting element 31 and a second light emitting element 32, respectively. Therefore, a redundant system can be configured, and even if either the first light emitting element 31 or the second light emitting element 32 fails, the function as the lighting device 2 can be maintained.

Further, as compared with the case where the first visible light source 11, the second visible light source 12, and the third visible light source 13 each have only one light emitting element, the first light emitting element 31 and the second light emitting element 32 emit light. The output can be suppressed respectively. Therefore, the life of the first light emitting element 31 and the second light emitting element 32 can be extended.

Further, since the lighting device 2 has the excitation light source 14, it is possible to selectively irradiate the excitation light necessary for obtaining fluorescence from the subject.

In addition, since light of a required wavelength can be emitted when it is required, it is possible to suppress an optical component having an unnecessary wavelength, and it is possible to reduce adverse effects on the subject, the operator, the observer, and the like. In addition, it is possible to selectively emit light in a controlled and controlled wavelength band without generating unnecessary light. Examples of unnecessary light include light in the ultraviolet region harmful to the eyes and skin, and light in the near infrared region as heat rays.

In addition, the light emission pattern can be selectively changed depending on the operation or purpose. For example, during operation as a normal visible light source, the first visible light source 11, the second visible light source 12, and the third visible light source 13 may be made to emit light, and the excitation light source 14 may not be made to emit light. It is also possible to emit only the wavelength required for fluorescence observation.

Further, a semiconductor laser light emitting element is used as the first light emitting element 31 and the second light emitting element 32. Therefore, higher output light can be emitted and the wavelength can be easily limited. Further, by using a solid-state device, a self-diagnosis function such as detecting a light emitting state can be realized.

Further, since the first detection circuit 38 is connected to the first light emitting element 31 and the second detection circuit 39 is connected to the second light emitting element 32, the states of the first light emitting element 31 and the second light emitting element 32 are respectively. Can be diagnosed individually.

For example, when the current detected by the first detection circuit 38 is less than the point A in FIG. 5, the illumination control unit 19 diagnoses that the light emission of the first light emitting element 31 is extremely weak or has stopped. be able to. Further, the lighting control unit 19 can also notify the user of the self-diagnosis result that the first light emitting element 31 has reached the end of its life based on the diagnosis result. Further, the illumination control unit 19 can increase the output of the second light emitting element 32 that has not reached the end of its life to continue the light emitting function as a visible light source.

Here, FIG. 7 is a graph showing the difference in the degree of deep penetration into the subject depending on the wavelength of light. In FIG. 7, P1 represents the degree of deep penetration of blue light, P2 represents the degree of deep penetration of green light, and P3 represents the degree of deep penetration of red light. Further, the region A1 surrounded by the broken line is a region safe for the living body.

By irradiating the laser beam with the power density in the region A1 that is safe for the living body, the laser beam can be penetrated from the surface of the subject to the depth of several millimeters. As a result, reflected light and diffused light are generated not only from the surface of the subject but also from a few millimeters behind. Therefore, in the lighting device 2 of the first embodiment, unlike a general light source, the subject can be observed brighter, clearer, and more vividly.

For example, when the dried meat is irradiated with light from xenon illumination, most of the surface reflected light appears to emphasize the dry state of the surface. On the other hand, when the dried meat is irradiated with the light from the lighting device 2 of the first embodiment, the light from the lighting device 2 penetrates into the inside of the dried meat. Therefore, the color is developed even from a few millimeters deep from the surface of the dried meat, the dried meat looks very clear, and the dried meat may look like raw meat depending on the irradiation conditions. This is because the power density of the light from the lighting device 2 is higher than the power density of the xenon lighting.

Further, as shown in FIG. 7, the degree of penetration into the subject differs depending on the wavelength of light. Specifically, the longer the wavelength, the higher the degree of penetration. By utilizing this characteristic, a short wavelength light is used for a portion close to the surface of the subject and a long wavelength light is used for a portion deep inside the subject, so that the subject can be projected more clearly.

Depending on the purpose of observation, only one wavelength may be used, or a plurality of wavelengths may be used in combination. Further, when a plurality of wavelengths are used in combination, it is possible to further emphasize the portion to be observed in the subject by making a difference in the power density and intensity of each wavelength.

FIG. 8 is a diagram showing an example of an image obtained by irradiating light with xenon illumination. FIG. 9 is a diagram showing an image obtained by irradiating the same subject as in FIG. 8 with light by the lighting device 2 of the first embodiment. The image of FIG. 9 is brighter and clearer than the image of FIG.

FIG. 10 is an explanatory diagram showing a state of light when the image of FIG. 8 is obtained. The direct light L1 emitted from the xenon illumination is reflected on the surface of the subject and becomes the reflected light L2.

FIG. 11 is an explanatory diagram showing a state of light when the image of FIG. 9 is obtained. The direct light L3 emitted from the illuminating device 2 is reflected on the surface of the subject and becomes the reflected light L4. Further, the direct light L5, which is a part of the direct light L3 emitted from the lighting device 2, penetrates into the inside of the subject and becomes reflected light or diffused light L6.

As described above, according to the lighting device 2, since the reflected light or the diffused light L6 from the inside of the subject is added to the normal reflected light L4, the three-dimensional reflected light can be seen, and the whole is bright and vivid. You can observe the subject, especially the living body. Further, it is possible to obtain an observation light image not only on the surface of the subject but also in the deep part of the subject.

Here, "color rendering property" is an objective evaluation method regarding the color of illumination, and is defined in JIS Z 8726: 1990.

FIG. 12 is a diagram showing an example of a color rendering index when a lighting device that emits light having one wavelength for each of the red wavelength band, the green wavelength band, and the blue wavelength band is used. In the example of FIG. 12, the average color rendering index Ra is about 50. The special color rendering index R9 is about −70. It can be said that these values are considerably lower than those close to 100, which are considered to be closer to natural light.

On the other hand, FIG. 13 is a diagram showing an example of a color rendering index when the lighting device 2 of the first embodiment is used. In the example of FIG. 13, the average color rendering index Ra is 80. Further, the special color rendering index R9 is 30. As described above, in the lighting device 2 of the first embodiment, the color reproducibility is improved and the evaluation result closer to that of natural light is obtained.

The number of visible light sources is not limited to three.

Further, not all visible light sources need to be multi-wavelength light sources, and if at least one visible light source is a multi-wavelength light source, the color rendering property can be improved as compared with the case where the multi-wavelength light source is not provided.

Further, the wavelength of the light emitted by each multi-wavelength light source is not limited to the above example. For example, the central wavelength of the light emitted by the blue visible light source is not limited to 450 nm and 462 nm, and may be 440 nm or 460 nm if a plurality of wavelengths that can form blue as visible light are selected.

Further, the bandwidth of the wavelength of the light emitted by each visible light source is not limited to ± 2 nm, and may be, for example, about ± 10 nm. Further, when it is used for measurement, a narrower band, for example, ± 0.2 nm may be used.

Further, the multi-wavelength light source may emit light having three or more wavelengths different from each other within the wavelength band of the corresponding color, whereby the color rendering property can be further improved. Further, by increasing the number of lights having different wavelengths, the light emission output of each can be suppressed, and the life of the light emitting element can be extended.

Further, the lighting control unit may monitor the secular variation of the current of the light emitting element detected by each detection circuit as a self-diagnosis function. In this case, when the detected current value drops to the lowering threshold value, it may be determined that the light emission is about to stop and the user may be notified. The lowering threshold value is set, for example, to a value higher than the point A in FIG. 5 by a margin.

Further, the central wavelength and bandwidth of the light emitted by the excitation light source are not limited to the above examples, and may be, for example, 800 nm ± 5 nm near the peak of the excitation efficiency.

The wavelength of the light emitted by the excitation light source is not limited to the excitation wavelength of indocyanine green, for example, at 490 nm, which is the excitation wavelength of fluorescein, or 400 nm, which is the excitation wavelength of 5-ALA (5-aminolevulinic acid). There may be. Fluorescein and 5ALA are fluorescent angiography agents. For example, in the case of fluorescein, by emitting light only from the excitation light source 14, it is possible to obtain a fluorescence image more efficiently than LED illumination and xenon illumination having broad characteristics.

Further, the visible light source may also serve as an excitation light source. For example, light having a wavelength of 490 nm, which is the excitation wavelength of fluorescein, may be emitted from a blue visible light source. In this case, when used as visible light illumination, three visible light sources need to be driven at the same time, and when fluoresceian angiography observation is performed, only a light emitting element having a wavelength of 490 nm needs to be driven.

Further, the excitation light source may be omitted.

Further, the light emitting device is not limited to the semiconductor laser light emitting device, and may be an LED, another laser light emitting device, or the like as long as the wavelength and the band can be controlled and limited.

Further, the use of the lighting device is not limited to medical use, and may be industrial use. Specifically, the application of the lighting device is not limited to the endoscope device, and may be a shadowless lamp, a microscope, or the like.

2 Lighting device, 11 1st visible light source (multi-wavelength light source), 12 2nd visible light source (multi-wavelength light source), 13 3rd visible light source (multi-wavelength light source), 14 excitation light source, 19 lighting control unit, 21 mixer, 31 First light source element, 32 Second light source element.

Claims (6)

Multiple visible light sources that emit visible light of different colors,
It is equipped with a mixer that mixes the light emitted from the plurality of visible light sources.
The plurality of visible light sources include at least one multi-wavelength light source.
The multi-wavelength light source is a lighting device that emits light having a plurality of wavelengths different from each other within the wavelength band of the corresponding color. The lighting device according to claim 1, wherein the multi-wavelength light source has a plurality of light emitting elements that emit light having different wavelengths from each other. The lighting device according to claim 2, wherein the plurality of light emitting elements are semiconductor laser light emitting devices, respectively. Further equipped with an excitation light source that emits light of the excitation wavelength of the fluorescence contrast agent,
The lighting device according to any one of claims 1 to 3, wherein the mixer is a mixture of light emitted from the plurality of visible light sources and light emitted from the excitation light source. Further, a lighting control unit for controlling the light emission of the plurality of visible light sources and the excitation light source is provided.
The lighting device according to claim 4, wherein the lighting control unit can selectively emit the plurality of visible light sources and the excitation light source. An endoscope device including the lighting device according to any one of claims 1 to 5.

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