JP7625249B2 - Light Concentrator - Google Patents

Description

The present invention relates to a light collecting device.

When cauterizing biological tissue by light irradiation, light in the infrared region is generally used (for example, Patent Document 1). In the light source described in Patent Document 1, light in the infrared region transfers direct heat to biological tissue. This is because, while 70% of the components of the cells that make up biological tissue are water, if it is assumed that the light absorption/scattering properties of biological tissue can be replaced by the absorption/scattering properties of water, the light absorption coefficient of water in the infrared region is higher than the light absorption coefficient of water in the visible light region.

U.S. Pat. No. 6,530,919

According to "Measurement and Calculation of Optical Properties of Biological Tissues" by Awazu Kunio, Graduate School of Life and Medical Sciences, Osaka University, Optics, Vol. 41, No. 8 (2012) the optical absorption coefficient in the visible light region is higher than that in the near-infrared region in the cells that make up biological tissues. This means that it is inefficient to directly use heat with wavelengths of infrared light to cauterize biological tissues, and that the absorption/scattering properties of water cannot be used as a direct substitute.

In addition, to cauterize biological tissue, it is necessary to raise the temperature of the area where light is irradiated to 60°C or higher. To achieve this, it is necessary to focus the light emitted from the light source on the area to be cauterized while minimizing loss of its light quantity and wavelength characteristics.

Furthermore, according to the internet site <https://www.mext.go.jp/b#menu/shingi/gijyutu/gijyutu3/toushin/attach/1333543.htm>, in biological tissues that contain hemoglobin, the light absorption coefficient in the ultraviolet and visible light regions is about two orders of magnitude higher than the light absorption coefficient in the near-infrared region.

Therefore, when cauterizing biological tissue by irradiating it with light, it is believed that by using light (light wavelength range) that matches the light absorption/scattering characteristics of biological tissue, including hemoglobin, and the light absorption/scattering characteristics of the cells that make up the biological tissue, it is possible to cauterize efficiently using the heat generated by the biological tissue absorbing/scattering the light.

The object of the present invention is to provide a light collecting device that can efficiently transmit light for cauterizing biological tissue.

The invention to achieve the above object is a light collecting device having a light source element and an optical system that irradiates light of a wavelength in a light range that matches the light absorption/scattering characteristics of biological tissue, the optical system being an optical system for guiding light emitted from the emission surface of the light source element to a light guide, comprising a vessel-shaped first mirror having a first reflecting surface for collecting the light near the end of the light guide, and a second mirror arranged inside the first mirror and having a second reflecting surface for reflecting a portion of the light reflected by the first reflecting surface toward the light guide, the shape of the first reflecting surface being the same as the shape of the half of the surface of the light guide side with respect to the origin of the spheroid, of the surface of a spheroid having a major axis on a first axis from the light source element toward the light guide. Other features of the invention will be made clear by the description of the specification and drawings described below.

The present invention provides a light-collecting device that can efficiently transmit light for cauterizing biological tissue.

FIG. 2 is a cross-sectional view for explaining the configuration of the irradiation device of the first embodiment. FIG. 11 is a cross-sectional view for explaining the configuration of an irradiation device according to a second embodiment. FIG. 11 is a cross-sectional view for explaining the configuration of an irradiation device according to a third embodiment. FIG. 11 is a perspective view for explaining the configuration of a third mirror. FIG. 13 is a diagram for explaining the configuration of a third mirror. 13A and 13B are diagrams illustrating a configuration of an irradiation device according to a modified example of the third embodiment. 13A and 13B are diagrams illustrating a configuration of an irradiation device according to a fourth embodiment. FIG. 13 is a diagram illustrating the configuration of a fourth mirror. 13A and 13B are diagrams illustrating a configuration of an irradiation device according to a fifth embodiment. 13A and 13B are diagrams illustrating a configuration of an irradiation device according to a sixth embodiment.

First Embodiment
==Irradiation device==
1 is a cross-sectional view for explaining the configuration of an irradiation device 10 of the present embodiment. The irradiation device 10 of the present embodiment includes a light source element 20, a light guide 30, and an optical system 40. The light source element 20 and the optical system 40 constitute a light collecting device 50.

For ease of explanation, the first axis X1 is defined as shown in FIG. 1 below. The first axis X1 is an axis in a direction from the light source element 20 toward the light guide 30 (details will be described later). FIG. 1 is a diagram showing a cross section of the irradiation device 10 cut along an arbitrary plane passing through the first axis X1.

[Light source element]
The light source element 20 is a device for causing the irradiation device 10 to irradiate light in the visible light region. The light source element 20 generates light in the visible light region. Specifically, the light source element 20 generates light in a wavelength region of 400 to 750 nm. Note that the wavelength region of the light generated by the light source element 20 can be selected according to the light absorption/scattering characteristics of the tissue to be cauterized.

The light source element 20 has an exit surface 20a. The light generated by the light source element 20 is emitted from the exit surface 20a to the outside of the light source element 20. At this time, it is preferable that the light generated by the light source element 20 is emitted evenly in various directions with respect to the normal direction of the exit surface 20a. In other words, it is preferable that the light source element 20 is a so-called diffuse light source element. Even if the light emitted from the light source element 20 is not uniform, if the shape of the first reflecting surface 401a is elliptical, the light emitted from the light source element 20 is concentrated at the first focal point F1.

There are no other restrictions on the light source element 20 than those mentioned above, but light source elements 20 using laser light sources, LED light sources, halogen lamps, xenon lamps, etc. can be used. In this embodiment, the emission surface 20a is perpendicular to the first axis X1.

[Light guide]
The light guide 30 is a member, such as an optical fiber, that propagates the light from the light source element 20 to the biological tissue. One end of the light guide 30 is provided with an incident surface 30a for allowing the light from the optical system 40 to enter. The light incident from the incident surface 30a propagates through the light guide 30 and is emitted from the other end (not shown) of the light guide 30. The biological tissue is cauterized by the light emitted from the other end of the light guide 30. In this embodiment, the area of the incident surface 30a is smaller than the area of the emission surface 20a.

[Optical system]
The optical system 40 guides the light emitted from the emission surface 20a of the light source element 20 to the incidence surface 30a of the light guide body 30. The optical system 40 of this embodiment includes a first mirror 401 and a second mirror 402.

(First Mirror)
The first mirror 401 is a vessel-shaped member. In this embodiment, the inside of the first mirror 401 has a shape based on an elliptical function. The shape based on the elliptical function may be replaced by a combination of straight lines that approximate the shape. The shape of the outer circumferential surface of the first mirror 401 is not limited. For simplicity, in this embodiment, the shape of the outer circumferential surface is the same as the shape of the inner circumferential surface.

The first mirror 401 has a first reflecting surface 401a and an exit port 401b that are shaped based on an elliptical function. The exit port 401b is the part where the light guide 30 is attached, but if the light guide 30 is not present, it becomes the exit port for the emitted light of the light source element 20 that has been condensed.

The first reflecting surface 401a is provided on the inner peripheral surface of the first mirror 401. The first reflecting surface 401a is a reflecting surface for focusing the light emitted from the exit surface 20a on the entrance surface 30a of the light guide 30 or near the entrance surface 30a. If the first reflecting surface 401a has an elliptical shape, the light is focused at the position of the first focus F1 of the elliptical shape. In this embodiment, "near the entrance surface 30a" also includes the entrance surface 30a.

Here, the shape of the first reflecting surface 401a will be described. The shape of the first reflecting surface 401a is the same as half of the surface of the spheroid.

Specifically, when the spheroid E is defined as shown in FIG. 1, the first reflecting surface 401a has the same shape as the half of the surface of the spheroid E that faces the light guide 30 with respect to the origin of the spheroid E. The long axis of the spheroid E is the first axis X1. In other words, the spheroid E is symmetrical with respect to the first axis X1. Also, in FIG. 1, the cross section of the spheroid E cut along a plane passing through the long axis is shown by a dashed line.

The light exit portion 401b is a cylindrical portion. One end of the light exit portion 401b is located near the position where the first axis X1 intersects with the surface of the half of the spheroid E that faces the light guide 30. The light guide 30 is inserted inside the light exit portion 401b.

Here, the positional relationship between the first mirror 401 and the incident surface 30a of the light guide 30 will be described. The incident surface 30a of the light guide 30 may be located at the position of the first focal point F1 or at a position near the first focal point F1.

As shown in FIG. 1, the two foci of the spheroid E, a first focus F1 and a second focus F2, are disposed on the first axis X1. The first focus F1 is the focus on the light guide 30 side of the two foci of the spheroid E. The second focus F2 is the other focus of the first focus F1. In the following, "near the focus F1" includes the focus F1.

By positioning the incident surface 30a at the position of the first focal point F1, the intensity of the incident light is maximized. On the other hand, by positioning the incident surface 30a near the position of the first focal point F1, heat generation at the incident surface 30a can be suppressed.

As shown in FIG. 1, in this embodiment, the incident surface 30a is located near the first focal point F1.

(Second mirror)
The second mirror 402 is a disk-shaped member and is disposed perpendicular to the first axis X1.

The second mirror 402 has a second reflecting surface 402a. The second reflecting surface 402a is a reflecting surface that reflects a portion of the light reflected by the first reflecting surface 401a toward the incident surface 30a of the light guide 30. The second reflecting surface 402a is provided on the surface of the second mirror 402 that is closer to the light guide 30 than the two parallel surfaces of the second mirror 402. In this embodiment, the second reflecting surface 402a is disposed on a plane that passes through the minor axis of the spheroid E defined in FIG. 1.

By providing such a second mirror 402, light whose extension line of the path it travels passes through the second focal point F2 in the optical system 40 reaches the first focal point F1 after being reflected by the second reflecting surface 402a. In other words, by providing the second mirror 402, light that would be focused at the second focal point F2 if the second mirror 402 did not exist can be focused at the first focal point F1 by being reflected by the second reflecting surface 402a.

As is clear from the above, in the irradiation device 10 of this embodiment, the shape of the first reflecting surface 401a is the same as the shape of the half of the surface of the spheroid E that has its major axis on the first axis X1 and is on the light guide 30 side with respect to the origin of the spheroid E.

With this configuration, a portion of the light emitted from the exit surface 20a is directly focused at the first focal point F1. Another portion of the light emitted from the exit surface 20a is reflected by the first reflecting surface 401a. A portion of the light reflected by the first reflecting surface 401a is focused at the first focal point F1. Another portion of the light reflected by the first reflecting surface 401a is reflected by the second reflecting surface 402a. A portion of the light reflected by the second reflecting surface 402a is focused at the first focal point F1 directly or after being further reflected by the first reflecting surface 401a.

That is, the light emitted from the exit surface 20a is focused near the first focus F1 directly or after being reflected by the first reflecting surface 401a or the second reflecting surface 402a. This allows the light emitted from the exit surface 20a of the light source element 20 to be efficiently incident on the incident surface 30a. Therefore, the light focusing device 50 can efficiently transmit light for cauterizing the living tissue. Here, the ratio of the area of the incident surface 30a to the area of the exit surface 20a is R. According to the irradiation device 10, the ratio of the intensity of the light incident on the incident surface 30a to the intensity of the light emitted from the exit surface 20a is greater than R. Therefore, the irradiation device 10 can obtain a value greater than the area ratio R for the light from the light source emitted from the exit surface 20a, which has an area larger than the incident surface 30a, to the light guide 30, and can increase the intensity of the light irradiated to the living tissue.

Second Embodiment
2 is a diagram illustrating the irradiation device 11 of the present embodiment. The irradiation device 11 of the present embodiment is different from the irradiation device 10 of the first embodiment in the configuration of the optical system 41. Specifically, the optical system 41 of the present embodiment further includes a convex lens 406. The light source element 20 and the optical system 41 constitute a light collecting device 51.

(convex lens)
The convex lens 406 is disposed between the emission surface 20a and the first focal point F1. The convex lens 406 is disposed so that the first axis X1 serves as the optical axis. The convex lens 406 here includes a biconvex lens, a plano-convex lens, a condenser lens, and the like. In this embodiment, a plano-convex lens is used as the convex lens 406.

The size of the convex lens 406 is such that its outer periphery contacts the inner periphery of the first mirror 401. The convex lens 406 is supported by the first mirror 401 by having its outer periphery fixed to the inner periphery of the first mirror 401. Note that the size of the convex lens 406 is not limited to this example, as long as it is supported by the first mirror 401.

By providing the convex lens 406, the proportion of light emitted from the exit surface 20a that is directly focused on the first focal point F1 without being reflected by the first reflecting surface 401a or the second reflecting surface 402a is increased. This reduces the loss of light due to reflection on the first reflecting surface 401a or the second reflecting surface 402a.

Third Embodiment
3 is a diagram illustrating the irradiation device 12 of the present embodiment. The irradiation device 12 of the present embodiment is different from the irradiation device 11 of the second embodiment in the configuration of the optical system 42. Specifically, the optical system 42 of the present embodiment further includes a third mirror 403. The light source element 20 and the optical system 42 constitute a light collecting device 52.

(Third Mirror)
The third mirror 403 is disposed between the emission surface 20a and the convex lens 406. The third mirror 403 has a light-shielding portion 403b. The surface of the third mirror 403 on the light source element 20 side is a light-shielding surface, which has the effect of reducing the temperature rise caused by the absorption coefficient of the convex lens 406, and the third reflecting surface 403a is a reflecting surface that reflects a part of the light reflected from the first reflecting surface 401a.

Figure 4A is a perspective view for explaining the third mirror 403 of this embodiment. Figure 4B is a view for explaining the third mirror 403 of this embodiment, in which the third mirror 403 is viewed in the direction of the first axis X1 from the light guide 30 side. The third mirror 403 of this embodiment has a third reflecting surface 403a, a light shielding portion 403b, and a support portion 403c.

The third reflecting surface 403a is a disk-shaped member. The third reflecting surface 403a has a center on the first axis X1 and is disposed perpendicular to the first axis X1. The light-shielding portion 403b is provided on the surface of the third reflecting surface 403a that is on the light source element 20 side, out of the two parallel surfaces of the third reflecting surface 403a.

The support 403c is a member for supporting the light shielding portion 403b. In this embodiment, the support 403c is composed of a circular frame 403d and four arms 403e, and the surface may form a reflective surface. The circular frame 403d is arranged around the light shielding portion 403b in a concentric manner with the light shielding portion 403b. Each of the four arms 403e has one end connected to the light shielding portion 403b and the other end connected to the frame 403d. The four arms 403e are arranged radially with respect to the center of the light shielding portion 403b. This is also for diffusing heat due to the light of the light shielding portion 403b. The circular frame 403d is fixed to the inner circumferential surface of the first mirror 401. As a result, the third mirror 403 is fixed to the first mirror 401.

By providing the third mirror 403, the proportion of light emitted from the exit surface 20a that directly enters the convex lens 406 is reduced. This makes it possible to suppress heat generation caused by a local increase in the intensity of light entering the convex lens 406.

It is preferable that the light emitted from the emission surface 20a, other than the light that reaches the third reflecting surface 403a, is not absorbed and lost by the third mirror 403. Therefore, it is preferable that the frame 403d and the arm 403e are thin and the number of arms 403e is small. In addition, the third mirror 403 may have a reflecting surface formed on the entire surface of the third mirror 403, rather than only the light-shielding portion 403b formed on one surface of the third reflecting surface 403a.

Figure 5 is a diagram for explaining the configuration of an irradiation device 12' according to a modified example of this embodiment, showing an enlarged view of the shape of the third reflecting surface 403b' when the light-shielding portion 403b is used as the reflecting surface. As shown in Figure 5, the third reflecting surface 403b' may be convex toward the light source element 20. In the example of Figure 5, the shape of the third reflecting surface 403b' is a conical surface that is axially symmetric with respect to the first axis X1.

With this configuration, it is possible to prevent light reflected by the third reflecting surface 403b' from returning from the exit surface 20a into the light source element 20.

Fourth Embodiment
6 is a diagram illustrating the irradiation device 13 of the present embodiment. The irradiation device 13 of the present embodiment is different from the irradiation device 11 of the second embodiment in the configuration of the optical system 43. Specifically, the optical system 43 of the present embodiment further includes a fourth mirror 404. The light source element 20 and the optical system 43 constitute a light collecting device 53.

(4th mirror)
The fourth mirror 404 is disposed between the convex lens 406 and the first focal point F1.

Figure 7 is a perspective view for explaining the fourth mirror 404 of this embodiment. The fourth mirror 404 of this embodiment has a fourth reflecting surface 404a, a convex portion 404b, and a support portion 404c. The fourth reflecting surface 404a is convex toward the light source element 20.

In this embodiment, the convex portion 404b is a cone-shaped member. The convex portion 404b has a cone shape with the first axis X1 as the axis of rotation. The fourth reflecting surface 404a is provided on the conical surface of the convex portion 404b.

The support portion 404c is a member for supporting the convex portion 404b. In this embodiment, the support portion 404c is composed of a circumferential frame 404d and an arm 404e. The circumferential frame 404d is arranged around the convex portion 404b in a concentric manner with the bottom surface of the convex portion 404b. One end of the arm 404e is connected to the convex portion 404b, and the other end is connected to the frame 404d. The circumferential frame 404d is fixed to the inner circumferential surface of the first mirror 401. This fixes the fourth mirror 404 to the first mirror 401.

It is preferable that, of the light traveling toward the first focal point F1, light other than the light that reaches the fourth reflecting surface 404a is not absorbed and lost by the fourth mirror 404. Therefore, it is preferable that the arm 404e is thin and the number of arms 404e is small. Also, in the fourth mirror 404, a reflecting surface may be formed on the entire surface of the fourth mirror 404, for example, rather than only on the fourth reflecting surface 404a formed on the conical surface of the convex portion 404b.

By providing the fourth mirror 404, the proportion of light focused at the first focal point F1 is reduced. This makes it possible to suppress heat generation caused by a local increase in the intensity of light entering the light guide 30.

Fifth Embodiment
8 is a cross-sectional view for explaining the irradiation device 14 of the present embodiment. The irradiation device 14 of the present embodiment is different from the irradiation device 12 of the third embodiment in the configuration of the optical system 44. Specifically, the optical system 44 of the present embodiment further includes a fifth mirror 405. The light source element 20 and the optical system 44 constitute a light collecting device 54.

(5th mirror)
The fifth mirror 405 is a cylindrical member and has a fifth reflecting surface 405 a. The fifth reflecting surface 405 a is provided on the inner circumferential surface of the fifth mirror 405.

The shape of the fifth reflecting surface 405a is axially symmetrical with respect to the first axis X1, and is the same shape as the surface of a cylinder whose diameter is the length of the minor axis of the spheroid E. That is, the cross-sectional shape of the inner peripheral surface of the fifth mirror 405 in a plane perpendicular to the first axis X1 is a circle whose diameter is the minor axis of the spheroid E. Alternatively, the shape of the fifth reflecting surface 405a may be multiple times rotationally symmetrical with respect to the first axis X1, and may be the same shape as the surface of a cylinder containing a cylinder whose diameter is the length of the minor axis of the spheroid E. That is, the cross-sectional shape of the inner peripheral surface of the fifth mirror 405 in a plane perpendicular to the first axis X1 may be a polygon. There are no particular limitations on the polygon, and it may be, for example, a regular hexagon.

The fifth mirror 405 is disposed between the first mirror 401 and the second mirror 402. Therefore, the fifth reflecting surface 405a is disposed between the first reflecting surface 401a and the second reflecting surface 402a. One end of the fifth reflecting surface 405a is connected to the first reflecting surface 401a on the circumference of the surface of the spheroid E through which the minor axis of the spheroid E passes. The other end of the fifth reflecting surface 405a is connected to the second reflecting surface 402a on the circumference.

Sixth Embodiment
9 is a cross-sectional view for explaining the irradiation device 15 of the present embodiment. The irradiation device 15 of the present embodiment is different from the irradiation device 12 of the third embodiment in the configuration of the light collecting device 55.

The second mirror 402 in this embodiment has an opening 402b. The light source element 21 causes light from the light source to enter the optical system 45 through the opening 402b. The light source element 21 is disposed outside the first mirror 401.

[Light source side light guide]
The light collecting device 55 of this embodiment further includes a light-source-side light guide 210. The light-source-side light guide 210 guides light from the light source element 21 to the optical system 45. One end of the light-source-side light guide 210 is connected to the second mirror 402 via an opening 402b. In this embodiment, one end of the light-source-side light guide 210 corresponds to the emission surface 21a. The light from the light source element 21 is incident on the other end of the light-source-side light guide 210.

With this configuration, there is no need to provide the light source element 21 inside the first mirror 401, so restrictions on the size of the light source element 21, etc. are relaxed, and the degree of freedom in selecting the light source element 21 is increased.

The light collecting device 55 of this embodiment includes the light source side light guide 210, but is not limited to this. For example, the light source side light guide 210 may be omitted, and the light from the light source element 21 may be directly incident on the optical system 45 through the opening 402b. In such a case, the opening 402b corresponds to the emission surface 21a. In addition, in such a case, in order to prevent foreign matter such as dust from entering the inside of the optical system 45 through the opening 402b, the opening 402b may be covered or filled with a transparent member.

As described above, the light collecting devices 50 to 55 of the first to sixth embodiments are light collecting devices 50 to 55 having light source elements 20, 21 and optical systems 40 to 45 that irradiate light in accordance with the light absorption/scattering characteristics of biological tissue, and the optical systems 40 to 45 are optical systems 40 to 45 for guiding the light emitted from the emission surfaces 20a, 21a of the light source elements 20, 21 to the light guide 30, and have a first reflecting surface 401 for collecting the light near the end of the light guide 30. a) and a second mirror 402 having a second reflecting surface 402a that reflects a portion of the light reflected by the first reflecting surface 401a toward the light guide 30. The shape of the first reflecting surface 401a is the same as the shape of the half of the surface of the spheroid E that is on the light guide 30 side with respect to the origin of the spheroid E, of the surface of the spheroid E that has a major axis on the first axis X1 that faces the light guide 30 from the light source elements 20, 21 toward the light guide 30.

With this configuration, a portion of the light emitted from the emission surfaces 20a, 21a is directly focused at the first focal point F1. Another portion of the light emitted from the emission surfaces 20a, 21a is reflected by the first reflecting surface 401a. A portion of the light reflected by the first reflecting surface 401a is focused at the first focal point F1. Another portion of the light reflected by the first reflecting surface 401a is reflected by the second reflecting surface 402a. A portion of the light reflected by the second reflecting surface 402a is focused at the first focal point F1 directly or after being further reflected by the first reflecting surface 401a.

That is, the light emitted from the exit surfaces 20a, 21a is focused near the first focal point F1, either directly or after being reflected by the first reflecting surface 401a or the second reflecting surface 402a. Therefore, by arranging the incident surface 30a of the light guide 30 near the first focal point F1, the light emitted from the exit surfaces 20a, 21a of the light source elements 20, 21, which have a larger area than the incident surface 30a, can be efficiently incident on the incident surface 30a. That is, according to the light focusing devices 50 to 55 of this embodiment, the light emitted from the exit surfaces 20a, 21a can have a value larger than the area ratio R, and the intensity of the light irradiated to the living tissue can be increased.

In the light collecting devices 51 to 55 of the second to sixth embodiments, the optical systems 41 to 45 further include a convex lens 406 disposed between the exit surfaces 20a, 21a and a first focus F1, which is the focus on the light guide 30 side of the two focuses of the spheroid E. With this configuration, the proportion of light that is directly collected at the first focus F1 among the light that is emitted from the exit surfaces 20a, 21a and passes through the convex lens 406 increases. This reduces the loss of light due to reflection at the first reflecting surface 401a or the second reflecting surface 402a. Therefore, it is possible to provide light collecting devices 51 to 55 that can transmit light for cauterizing biological tissue more efficiently.

In the third embodiment of the light collecting device 52, the third mirror 403 is disposed between the exit surface 20a and the convex lens 406, and has a third reflecting surface 403a that reflects a portion of the light emitted from the exit surface 20a. With this configuration, a portion of the light reflected by the first reflecting surface 401a is reflected by the third reflecting surface 403a, and the light blocking portion 403b blocks the direct light from the exit surface 20a. This reduces the proportion of light that directly enters the convex lens 406. Therefore, it is possible to suppress heat generation caused by a local increase in the intensity of light incident on the convex lens 406, and it is also possible to suppress heat generation in the light source element 20 by reflecting the light that is returning to the exit surface 20a by the third reflecting surface 403a.

In addition, in the optical system 42 of the focusing device 52 of the third embodiment, the light shielding portion 403b may be convex toward the light source side and may be a reflective surface. With this configuration, it is possible to prevent light reflected by the light shielding portion 403b from returning from the light exit surface 20a into the light source element 20. This makes it possible to provide an optical system 42 that can cauterize biological tissue more efficiently while suppressing heat generation caused by a local increase in the intensity of light incident on the convex lens 406.

In the optical system 42 of the focusing device 52 of the third embodiment, the light shielding portion 403b may be configured as a conical surface symmetrical with respect to the first axis X1. With such a configuration, it is possible to prevent light reflected by the light shielding portion 403b from returning from the exit surface 20a to the light source element 20, and to guide the light to the first reflecting surface 401a. This makes it possible to provide an optical system 42 that can cauterize biological tissue more efficiently while further suppressing heat generation caused by a local increase in the intensity of light incident on the convex lens 406.

In the fourth embodiment of the focusing device 53, the optical system 43 further includes a fourth mirror 404 disposed between the convex lens 406 and the first focal point F1 and having a fourth reflecting surface 404a that is convex toward the light source. With this configuration, a portion of the light emitted from the exit surface 20a is reflected by the fourth reflecting surface 404a. This reduces the proportion of light that is directly focused at the first focal point F1 after passing through the convex lens 406. This makes it possible to suppress heat generation caused by a local increase in the intensity of light incident on the light guide 30.

In the light collecting device 54 of the fifth embodiment, the optical system 44 further includes a fifth mirror 405 having a fifth reflecting surface 405a arranged between the first reflecting surface 401a and the second reflecting surface 402a, and the shape of the fifth reflecting surface 405a is axially symmetrical with respect to the first axis X1, and has a shape similar to the surface of a cylinder whose diameter is the length of the short axis of the spheroid E, or a polygon that contains the above-mentioned cylinder, and further includes a fifth mirror 405 having a fifth reflecting surface 405a whose one end is connected to the first reflecting surface 401a on the circumference of the surface of the spheroid E through which the short axis passes. With this configuration, by adjusting the length of the fifth reflecting surface 405a in the first axis X1 direction, it is possible to adjust the focusing position of the light emitted from the emission surface 20a when the first mirror 401 is used as a reference. This increases the degree of freedom in designing the optical system 44.

In the sixth embodiment of the focusing device 55, the second mirror 402 of the optical system 45 has an opening 402b, and the light source element 21 causes light from the light source element 21 to enter the optical system 45 through the opening 402b. With this configuration, it is not necessary to provide the light source element 21 inside the optical system 45, so restrictions on the size of the light source element 21, etc. are relaxed, and the degree of freedom in selecting the light source element 21 is increased.

The light collecting device 55 of the sixth embodiment further includes a light source side light guide 210, one end of which is connected to the second mirror 402 via the opening 402b, one end of which is the emission surface 21a, and the other end into which light from the light source element 21 is incident. With this configuration, it is not necessary to provide the light source element 21 inside the optical system 45, so restrictions on the size of the light source element 21, etc. are relaxed, and the degree of freedom in selecting the light source element 21 is increased.

The above embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the scope of the present invention. Furthermore, the present invention may be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents.

For example, in the irradiation device 14 of the fifth embodiment and the irradiation device 15 of the sixth embodiment, the optical system 44 may not include at least one of the convex lens 406 and the third mirror 403. In addition, the irradiation device 14 of the fifth embodiment and the irradiation device 15 of the sixth embodiment may further include the fourth mirror described in the fourth embodiment.

10: Irradiation device 11: Irradiation device 12: Irradiation device 13: Irradiation device 14: Irradiation device 15: Irradiation device 20: Light source element 20a: Emission surface 21: Light source element 21a: Emission surface 210: Light source side light guide 30: Light guide 30a: Incident surface 40: Optical system 41: Optical system 42: Optical system 43: Optical system 44: Optical system 45: Optical system 401: First mirror 401a: First reflecting surface 401b: Emission port 402: Second mirror 402a: Second reflecting surface 402b: Opening 403: Third mirror 403a: Third reflecting surface 403b: Light shielding portion 403b': Third reflecting surface 403c: Support portion 403d: Frame 403e: Arm 404: Fourth mirror 404a: Fourth reflecting surface 404b: Convex portion 404c: Support portion 405: Fifth mirror 405a: Fifth reflecting surface 406: Convex lens 50: Light collecting device 51: Light collecting device 52: Light collecting device 53: Light collecting device 54: Light collecting device 55: Light collecting device X1: First axis F1: First focal point F2: Second focal point E: Spheroid

Claims (8)

A light collecting device having a light source element and an optical system that irradiates light in accordance with the light absorption characteristics and light scattering characteristics of biological tissue,
The optical system is an optical system for guiding light emitted from an emission surface of the light source element to a light guide,
a first mirror having a vessel shape and a first reflecting surface for focusing the light near an end of the light guide;
a second mirror disposed inside the first mirror and having a second reflecting surface that reflects a portion of the light reflected by the first reflecting surface toward the light guide;
Equipped with
a shape of the first reflecting surface is the same as a shape of a half surface of a spheroid having a major axis on a first axis from the light source element toward the light guide, the half surface being on the light guide side with respect to a center of the spheroid where a minor axis and a major axis of the spheroid intersect ,
The optical system further includes a convex lens disposed between the emission surface and a first focus, which is one of two focuses of the spheroid and is located on the light guide side.
Light collecting device. The light collecting device according to claim 1 , wherein the optical system further comprises a third mirror disposed between the exit surface and the convex lens and having a third reflecting surface that reflects a portion of the light emitted from the exit surface . The light collecting device according to claim 2 , wherein the third reflecting surface is convex toward the light exit surface. The light collecting device according to claim 3 , wherein the third reflecting surface forms a conical surface that is symmetrical with respect to the first axis. The focusing device according to any one of claims 1 to 4 , wherein the optical system further comprises a fourth mirror disposed between the convex lens and the first focal point and having a fourth reflecting surface that is convex toward the exit surface. the optical system further includes a fifth mirror having a fifth reflecting surface disposed between the first reflecting surface and the second reflecting surface,
The focusing device of any one of claims 1 to 5, further comprising a fifth mirror having a fifth reflecting surface, the shape of which is axially symmetrical with respect to the first axis, a shape similar to the surface of a cylinder whose diameter is the length of the short axis of the spheroid, or a polygon that contains the cylinder, and one end of which has a fifth reflecting surface that is connected to the first reflecting surface on a circumference through which the short axis passes, on the surface of the spheroid. 7. The light collecting device according to claim 1, wherein the second mirror has an opening for allowing the light from the light source element to enter the optical system. The light collecting device according to claim 7 , further comprising a light source side light guide, one end of which is connected to the second mirror via the opening, the one end being the emission surface, and the other end into which the light from the light source element is incident.

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